Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/10/15


AREA FORECAST DISCUSSION
NWS PUEBLO CO
1123 PM MDT TUE APR 7 2015 .UPDATE... ISSUED AT 830 PM MDT TUE APR 7 2015 ALLOWED THIS EVENINGS RED FLAG WARNING TO EXPIRE. IN ADDITION... ADDED AREAS OF DENSE FOG TO SECTIONS OF THE FAR SOUTHEASTERN COLORADO PLAINS FROM LATER TONIGHT INTO WEDNESDAY MORNING. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 251 PM MDT TUE APR 7 2015 ...EXTREME FIRE WEATHER CONDITIONS ON WEDNESDAY... RED FLAG CONDITIONS CURRENTLY BEING MET OVER MOST OF THE CWA...EXCEPT NR THE KS BORDER OVER THE FAR SERN PLAINS...WHERE QUASI- STATIONARY BOUNDARY IS HOLDING STEADY AND ERLY WINDS STILL MAINTAINING DEW POINTS IN THE 20S-30S. WILL SEE GUSTY SW WINDS CONTINUE OVER THE REST OF OUR AREA THROUGH EARLY EVE. THE ERLY PUSH SHOULD ADVANCE INTO CROWLEY AND OTERO COUNTIES TONIGHT...POSSIBLY MAKING A RUN TOWARDS KPUB...BUT LOW CLOUDS WILL PROBABLY BE CONFINED TO THE FAR NERN COUNTIES. STILL LOOKS LIKE TOMORROW WILL SEE THE WORST OF THE CRITICAL FIRE WX CONDITIONS. MAY TAKE A WHILE FOR ERN COUNTIES TO MIX OUT DO TO THE OVERNIGHT PUSH OF LOW LEVEL MOISTURE...BUT BY MID TO LATE AFTERNOON SHOULD SEE RH FALL BELOW 10 PERCENT FOR MOST SPOTS...AND SW WINDS GUSTING IN THE 30-40 KT RANGE. THE WORST CONDITIONS LOOK TO BE ALONG AND NR THE I-25 CORRIDOR FROM KPUB AND SOUTHWARD...BUT IT WILL NOT BE MUCH BETTER ELSEWHERE. NEEDLESS TO SAY...WILL HAVE TO BE EXTREMELY CAUTIOUS TOMORROW TO AVOID FIRE STARTS SINCE ANY FIRE COULD QUICKLY GET OUT OF CONTROL. TEMPS ALOFT WILL BE ON THE COOL SIDE THROUGH TOMORROW...SO DESPITE THE STRONG WRLY FLOW SHOULD SEE TEMPS GENERALLY REMAIN IN THE 60S TO AROUND 70 OVER THE I-25 CORRIDOR...AND IN THE 70S FOR THE ERN PLAINS TOMORROW. NO PRECIP IS EXPECTED UNTIL TOMORROW AFTERNOON...THEN SHOULD SEE SOME LIGHT SHSN DEVELOP OVER THE CONTDVD. ANY ACCUMS TOMORROW WILL GENERALLY BE LIGHT AND CONFINED TO THE HIGHER PEAKS ALONG THE DVD. HAVE CUT BACK POPS A BIT MORE FOR THE REST OF OUR AREA TOMORROW...AS MOST GUIDANCE KEEPS THE PRECIP N OF OUR AREA WITH THE H5 CENTER RIDING EWD ALONG THE CO-WY BORDER. ROSE .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 251 PM MDT TUE APR 7 2015 AN UPR TROF WL BE MOVING ACRS THE AREA WED NIGHT...WITH WEST TO NW SFC WINDS ACRS THE AREA. IT LOOKS WINDY MANY AREAS IN THE EVENING AND JUST BREEZY THE REST OF THE NIGHT. THE FORECAST MODELS SHOW THE POTENTIAL FOR SOME SHOWERS OVER THE CENTRAL MTNS IN THE EVENING HRS...WITH DRY CONDITIONS ELSEWHERE. THE UPR TROF WL EXIT THE AREA THU MORNING...WITH BREEZY NORTH WINDS ACRS THE ERN PLAINS BEHIND THE TROF. THE WX LOOKS DRY IN THE MORNING BUT THERE COULD BE SOME ISOLD PCPN OVR SOME OF THE MTN AREAS IN THE AFTERNOON AND EARLY EVENING HOURS...ESPECIALLY OVR THE PIKES PEAK AREA AND THE CENTRAL MTNS. ALTHOUGH THERE WL BE SOME BREEZY CONDITIONS OVR THE FAR ERN PLAINS THU AFTERNOON...RH VALUES ARE EXPECTED TO BE TOO HIGH FOR FIRE WX CONCERNS. TEMPS ON THU WL BE COOLER IN THE WAKE OF THE TROF...BUT HIGH ARE FORECAST TO BE CLOSE TO AVERAGE. ON FRI WESTERLY FLOW ALOFT WL BE OVR THE FORECAST AREA WITH AN UPR TROF MOVING THRU THE NRN ROCKIES OF MTN AND WY. THE WX GENERALLY LOOKS DRY ON FRI WITH HIGH TEMPS A LITTLE ABOVE AVERAGE. SATURDAY THAT UPR TROF TO THE NORTH WL MOVE INTO THE DAKOTAS SENDING A FRONT INTO THE ERN CO PLAINS. A WEAK DISTURBANCE IN THE FLOW WL MOVE ACRS THE AREA SAT AND COULD BRING A FEW SHOWERS. THE GFS KEEPS THE BEST MSTR AND PCPN TO THE EAST...WHILE THE ECMWF SHOWS PCPN CHANCES ACRS MUCH OF THE AREA SAT AFTERNOON. FOR NOW WL JUST GO WITH SOME ISOLD POPS OVR THE MTNS AND NR THE KS BORDER. FOR SUN AN UPR TROF IS FORECAST TO MOVE INTO WRN CO AND WRN NM LATE IN THE DAY. CONDITIONS ARE STILL GENERALLY DRY ACRS THE FORECAST AREA...WITH THE POSSIBLE EXCEPTION OF SOME ISOLD TO SCT MTNS SHOWERS. HIGH TEMPS SHOULD AGAIN BE ABOVE AVERAGE. SUN NIGHT AND EARLY MON THAT TROF MOVES ACRS THE STATE...POSSIBLY BRINGING A FEW SHOWERS TO THE AREA. AS THE TROF EXITS THE STATE TO THE EAST...SOME BREEZY NORTHERLY WINDS CAN BE EXPECTED IN ITS WAKE...ALONG WITH SOME SLIGHTLY COOLER TEMPS. ON TUE AS A NEW UPR TROF MOVES INTO THE WRN STATE...BREEZY SWRLY WINDS RETURN TO THE AREA ALONG WITH THE POTENTIAL FOR CRITICAL FIRE WX CONDITIONS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1116 PM MDT TUE APR 7 2015 MOIST AIR MASS AND ACCOMPANYING IFR STRATUS AND FOG CONTINUE TO BACK SOUTHWESTWARD ACROSS THE COLORADO PLAINS THIS EVENING...WITH 04Z HRRR NOW SUGGESTING BOUNDARY WILL PUSH ALL THE WAY WEST TO KPUB AND KCOS OVERNIGHT BEFORE RETREATING EASTWARD QUICKLY DURING THE DAY WED. UNSURE IF STRATUS DECK WILL MAKE IT AS FAR WEST AS WIND SHIFT DOES...SO WILL KEEP BOTH KCOS AND KPUB TAFS VFR OVERNIGHT AND THROUGH THE DAY WED...AND INTRODUCE ONLY SOME SCT LOWER CLOUDS AT THIS POINT. IFR CONDITIONS WON`T BE TOO FAR AWAY FROM KCOS BY 12Z...AND SUSPECT KFLY AND KMNH WILL SEE A PERIOD OF LOWER CLOUDS IN THE MORNING. KALS WILL REMAIN VFR OVERNIGHT AND THROUGH THE DAY WED. W-SW WINDS WILL INCREASE ALL TERMINALS BY 18Z...WITH GUSTS IN THE 30-40 KNOT RANGE WIDESPREAD DURING THE AFTERNOON. && .PUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 11 AM TO 8 PM MDT WEDNESDAY FOR COZ222- 224>237. && $$ AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
938 PM EDT THU APR 9 2015 .SYNOPSIS... AM APPROACHING WARM FRONT WILL BRING A PERIOD OF RAIN LATER TONIGHT. THE FRONT LIFTS NORTH OF THE AREA FRIDAY AFTERNOON WITH MUCH MILDER TEMPS AND A LULL IN THE PRECIPITATION. A COLD FRONT SWINGS THROUGH FRIDAY EVENING WITH A ROUND OF SHOWERS. HIGH PRESSURE WILL YIELD SEASONABLE TEMPS AND DRY WEATHER FOR THE WEEKEND. A COLD FRONT MAY BRING SHOWERS MONDAY NIGHT FOLLOWED BY DRY AND MORE SEASONABLE WEATHER THROUGH MIDWEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... 930 PM UPDATE... SHOWERS ASSOCD WITH 850 MB WARM FRONT AND NOSE OF THE LOW LEVEL JET MOVING EAST FROM CENTRAL AND E NY. HRRR BRINGS RAIN INTO W ZONES BY 05Z THEN SPREADING EAST ACROSS REST OF THE REGION 06-09Z. TEMPS ACROSS HIGHER ELEVATIONS IN N MA AROUND 32 SO THERE IS A RISK OF POCKETS OF FZRA/FZDZ. OTHERWISE...AREAS OF DRIZZLE AND FOG WILL PERSIST AS THE SFC WARM FRONT REMAINS WEST OF THE REGION. UPDATED POPS USING THE HRRR AS A BASELINE. RAIN WILL BE MOST WIDESPREAD ACROSS NORTHERN MA WHERE FORCING FOR ASCENT IS STRONGEST. TEMPS WILL BEGIN TO SLOWLY RISE LATE TONIGHT AS THE SFC RIDGING ERODES AND LOW LEVEL FLOW TURNS SOUTHERLY. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... FRIDAY... WARM FRONTAL RAINS MAY LINGER INTO THE AM COMMUTE ACROSS EASTERN MA AND RI. OTHERWISE EXPECTING A BIT OF A LULL IN THE PRECIP FROM LATE MORNING INTO EARLY-MID AFTERNOON. WARM SECTOR IS SLOW IS OVERSPREAD THE AREA WITH TEMPS JUMPING INTO THE 50S REGIONWIDE BETWEEN 5 PM AND 8 PM. LOW PROB SOME TOWNS BRIEFLY TOUCH 60. IN ADDITION...DEW PTS JUMP INTO THE 50S LATE TOMORROW AND THIS HELP ERODE /VIA CONDENSATION/ REMNANT SNOWPACK ACROSS THE INTERIOR. LIKEWISE THIS WILL RESULT IN PATCHY FOG. COLD FRONT APPROACHES WESTERN MA/CT BY 21Z WITH A BAND OF SHOWERS LIKELY...PROBABLY ENTERING EASTERN MA AND RI BY 00Z. ISOLATED THUNDER POSSIBLE AS STRONG LOW LEVEL JET YIELDS A WARM ANOMALY OF +20C AROUND 900 MB. THIS YIELDS MOIST ADIABATIC LAPSE RATES FROM 900- 700 MB. MODEST SYNOPTIC AND FRONTAL SCALE FORCING COMBINED WITH MARGINAL INSTABILITY ALOFT ALONG WITH PWATS NEAR +3 STD DEVIATIONS ABOVE CLIMO WILL LIKELY YIELD SOME SHOWERS WITH HEAVY DOWNPOURS. NOT EXPECTING ANY WIDESPREAD FLOODING BUT NUISANCE TYPE URBAN/POOR DRAINAGE FLOODING IS POSSIBLE AND COULD IMPACT/SLOW THE LATE DAY COMMUTE. NOT EXPECTING STRONG WINDS ALOFT TO MIX TO THE SURFACE GIVEN THE STRONG LOW LEVEL TEMP INVERSION. FRI NIGHT... EARLY EVENING SHOWERS LIKELY ACROSS RI AND EASTERN MA BUT QUICK IMPROVEMENT WITH THE FRONTAL PASSAGE LATER IN THE EVENING FROM WEST TO EAST. COLD AIR ADVECTION IS WEAK BEHIND THE FRONT SO TEMPS WILL BE RELATIVELY MILD FRI NIGHT/SAT AM WITH LOWS ONLY IN THE 40S. && .LONG TERM /SATURDAY THROUGH THURSDAY/... HIGHLIGHTS... * PLEASANT AND MORE SPRING-LIKE WEATHER EXPECTED THIS WEEKEND * COLD FRONT BRINGING A CHANCE OF RAIN SHOWERS ON MONDAY * SEASONAL TEMPS WILL CONTINUE INTO NEXT WEEK OVERVIEW... 12Z GUIDANCE IS IN GOOD AGREEMENT FOR THE LONG TERMS. SURFACE HIGH PRESSURE WILL SET UP OVER THE REGION THIS WEEKEND. A COLD FRONT WILL SWING THROUGH LATE MONDAY INTO EARLY TUESDAY BRINGING SHOWERS TO NEW ENGLAND. THE LATEST EC HAS SLOWED DOWN ON THE PASSAGE MAKING IT MORE IN LINE WITH THE GFS. STRONG RIDGE WILL BUILD IN BEHIND THE FRONT THROUGH THE GREAT LAKES BY MID-NEXT WEEK. MAY NEED TO WATCH QUICK MOVING SYSTEMS ON THE BACKSIDE OF THE FLOW...HOWEVER TRENDED TOWARDS DRY AND SEASONABLE WEATHER. GUIDANCE IS SHOWING A CHANGE IN THE PATTERN BY NEXT WEEK WITH A CUT-OFF LOW FLOATING ACROSS THE MIDWEST TOWARDS NEW ENGLAND. LOW CONFIDENCE ON WHEN AND WHERE THIS WILL SET UP BUT SOMETHING TO MONITOR OVER THE NEXT FEW DAYS. DETAILS... * WEEKEND...HIGH CONFIDENCE. COLD FRONTAL PASSAGE WILL BE WELL OFFSHORE BY SATURDAY ALLOWING FOR DRY AIR TO FILTER INTO THE REGION. UPPER LEVEL TROUGH AXIS WILL SWING THROUGH ON SATURDAY WHICH COULD ALLOW FOR DIURNAL CU TO OVER SPREAD AND TEMPS IN THE MID 50 TO UPPER 50S. WIND GUSTS WILL BE ON THE INCREASE ON THE BACKSIDE OF THE FRONT ALLOWING FOR GUSTS TO REACH NEAR 30MPH. SUNDAY...HIGH PRESSURE WILL SETTLE IN ALLOWING ALLOWING FOR A COOL MORNING ON SUNDAY. HOWEVER TEMPS WILL REBOUND THANKS TO FULL SUN AND DRY WEATHER. EXPECT HIGHS IN THE UPPER 50S TO LOW 60S WHICH IS NEAR OF SLIGHTLY ABOVE AVERAGE. MAY NEED TO WATCH FOR SEABREEZE DEVELOPMENTS. * MONDAY INTO TUESDAY...HIGHER CONFIDENCE. QUICK MOVING SHORTWAVE AND ASSOCIATED COLD FRONT WILL MOVE OVER THE REGION BY MONDAY NIGHT. AHEAD OF THIS FRONT SOUTHERLY FLOW WILL ALLOW FOR WAA PUSHING 850MB TEMPS TO 8C DURING THE DAY. THANKS TO MOSTLY CLEAR SKIES...WE COULD SEE TEMPS WARM INTO THE MID 60S. MAY NEED TO WATCH MONDAY FOR POSSIBLE ELEVATED FIRE WEATHER CONCERNS. STATE FIRE OFFICIALS HAVE DETERMINED THAT FUELS ESP ACROSS CT...RI AND SE MASS HAVE BEEN DRYING OUT AND EXPECT THIS TREND TO CONTINUE OVER THE WEEKEND. MONDAY WILL BE WINDY WITH RH LEVELS AROUND 30-40 PERCENT. WILL CONTINUE TO MONITOR OVER THE NEXT SEVERAL DAYS. FRONT WILL PASS THROUGH MONDAY EVENING/OVERNIGHT. UPPER LEVEL MOISTURE AND LIFT IS SOMEWHAT MARGINAL SO EXPECT JUST SCT SHOWERS. CONDITIONS WILL BE IMPROVING THROUGHOUT THE DAY ON TUESDAY KEEPING TEMPS INTO THE 60S. DRY AIR BEHIND THE FRONT WILL INCREASE THE WINDS UP TO 25 MPH. * WEDNESDAY INTO THURSDAY...MODERATE CONFIDENCE. UPPER LEVEL RIDGE OVER THE GREAT LAKES WILL CONTINUE TO BUILD DURING THE MID-WEEK. THIS WILL BRING HIGH PRESSURE OVER NEW ENGLAND. 850MB TEMPS WILL BE AROUND 4C SO ANTICIPATE TEMPS REACHING THE LOW TO MID 60S. HOWEVER IT WILL BE COOLER ALONG THE COAST. MAY NEED TO WATCH FOR SEABREEZE DEVELOPMENTS DURING THIS PERIOD. && .AVIATION /01Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. .SHORT TERM /THROUGH FRIDAY NIGHT/...MODERATE TO HIGH CONFIDENCE. AFTER 00Z...WIDESPREAD IFR/LIFR IN DRIZZLE AND FOG WITH RAIN OVERSPREADING THE REGION 04-06Z WEST...06-09Z EAST. FRI...IFR/LIFR EARLY ALONG WITH RAIN EXITING EASTERN MA. THEN SLIGHT IMPROVEMENT TO IFR/MVFR LATE MORNING INTO EARLY-MID AFTERNOON ALONG WITH A LULL IN PRECIP. LLWS LIKELY 16Z-03Z AS 50 KT LOW LEVEL SW JET MOVES ACROSS THE AREA. SHOWERS REDEVELOP 21Z WEST AND EXIT EASTERN MA 02Z. LOW RISK OF ISOLATED THUNDER ALONG WITH HEAVY DOWNPOURS. FRI NIGHT...IFR/LIFR EARLY ALONG WITH SHOWERS WITH EMBEDDED TSTM EASTERN MA MOVES OFFSHORE WITH QUICK IMPROVEMENT FROM WEST TO EAST TO VFR BY LATE FRI NIGHT ALONG WITH WIND SHIFT FROM SW TO WNW. KBOS TAF...MODERATE TO HIGH CONFIDENCE IN TRENDS. LLWS LIKELY 16Z FRI TO ABOUT 02Z SAT AS 50 KT LOW LEVEL SOUTHWEST JET MOVES ACROSS THE AREA. HEAVY SHOWERS WITH ISOLATED TSTM POSSIBLE 22Z FRI - 02Z SAT. SHARP IMPROVEMENT FRI NIGHT WITH FRONTAL PASSAGE. KBDL TAF...MODERATE TO HIGH CONFIDENCE IN TRENDS. BIG IMPROVEMENT FRI EVENING WITH WIND SHIFT. OUTLOOK...SATURDAY THROUGH TUESDAY... SATURDAY INTO MONDAY MORNING...HIGH CONFIDENCE. VFR. GUSTY WINDS ON SATURDAY UP TO 25-30 KTS. MONDAY AFTERNOON INTO THE OVERNIGHT...MODERATE CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF MVFR CONDITIONS IN SCT -SHRA. TUESDAY...HIGH CONFIDENCE. IMPROVING CONDITIONS TO VFR. GUSTY WEST WINDS UP TO 25 KTS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. .SHORT TERM /THROUGH FRIDAY/...HIGH CONFIDENCE. TONIGHT...NE WINDS 15-20 BECOMING SE AND THEN S TOWARD MORNING. VSBYS REDUCED IN RAIN AND FOG. FRIDAY...SW WINDS INCREASING AHEAD OF APPROACHING COLD FRONT WITH G25 KT POSSIBLE. FOG POSSIBLE WITH WARMER MORE HUMID AIRMASS OVERSPREAD CHILLY NEAR SHORE WATERS. RAIN IN THE MORNING TAPER OFF WITH SHOWERS LATE IN THE DAY AND EVENING. FRI NIGHT...FRONTAL PASSAGE IN THE EVENING WITH SW WINDS BECOMING WNW. VSBY IMPROVES WITH THE WIND SHIFT. OUTLOOK...SATURDAY THROUGH TUESDAY... SATURDAY THROUGH SUNDAY...HIGH CONFIDENCE. CHOPPY SEAS ON SATURDAY WILL DIMINISH BY SUNDAY AS HIGH PRESSURE BUILDS OVER THE WATERS. MONDAY...MODERATE CONFIDENCE. SOUTHWESTERLY WINDS AND SEAS INCREASE IN ADVANCE OF A COLD FRONT CROSSING THE WATERS BY LATE MONDAY AFTERNOON. SMALL CRAFT ADVISORIES MAY BE NECESSARY. TUESDAY...MODERATE CONFIDENCE. CAA WILL PUSH IN BEHIND THE FRONT ALLOWING FOR NW WINDS TO GUST BETWEEN 20-25 KTS. MAY NEED NEAR SHORE SCA. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ235-250- 251-254>256. && $$ SYNOPSIS...NOCERA/DUNTEN NEAR TERM...KJC SHORT TERM...NOCERA LONG TERM...DUNTEN AVIATION...NOCERA/DUNTEN MARINE...NOCERA/DUNTEN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
140 PM EDT WED APR 8 2015 .SYNOPSIS... A NEARLY STATIONARY FRONT WILL REMAIN TO THE SOUTH THROUGH THURSDAY. LOW PRESSURE MOVES THROUGH THE GREAT LAKES WITH A WARM FRONT APPROACHING THURSDAY NIGHT. THE WARM FRONT PUSHES NORTHWEST OF THE REGION EARLY FRIDAY WITH LOW PRESSURE DEEPENING IN SOUTHEAST CANADA. AN ASSOCIATED COLD FRONT WILL MOVE ACROSS FRIDAY EVENING. A SECONDARY WEAK COLD FRONT MOVES ACROSS SATURDAY WITH HIGH PRESSURE FROM THE WEST BUILDING INTO THE REGION FOR THE REST OF THE WEEKEND. HIGH PRESSURE MOVES OFFSHORE EARLY NEXT WEEK AFTER WHICH LOW PRESSURE APPROACHES FROM THE WEST. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FOR THIS UPDATE HAVE CUT BACK SIGNIFICANTLY ON CHANCES OF RAIN OR DRIZZLE. COOL/DRY AIR DAMMING WEST EXTENDING SW FROM STRONG HIGH PRESSURE BUILDING ACROSS NEW ENGLAND...WITH THE OKX 12Z SOUNDING VERY DRY BELOW 900 MB...AND LOW LEVELS FCST TO REMAIN SO THROUGH MUCH OF TODAY AS THE DAMMING REMAINS IN PLACE. THIS DAMMING SHOULD SHUNT MOST OF THE PRECIP ASSOCIATED WITH A DEVELOPING WEAK LOW E OF THE VA CAPE...AND WEAKEN SHOWERS MOVING E FROM THE SUSQUEHANNA VALLEY IN PA. HRRR STILL DOES FCST SOME OF THIS ACTIVITY TO MAKE IT INTO AREAS WEST OF NYC THIS AFTERNOON...WITH MORE ISOLD ACTIVITY FARTHER EAST VIA MOISTURE AND WEAK H7-8 LIFT...SO STILL HAVE SLIGHT CHANCE POP THIS AFTERNOON FOR SRN CT AND LONG ISLAND. HIGH TEMPS TODAY WILL LIKELY RUN 10-15 DEGREES BELOW SEASONABLE TODAY...LOWER/MID 40S. COMBINED WITH NE WINDS OF 15 TO 20 MPH AND GUSTS TO 30 MPH ALONG THE COAST BETWEEN THE HIGH TO THE NORTH AND DEVELOPING LOW TO OUR SOUTH...IT WILL BE A RAW DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... MODELS IN GOOD AGREEMENT WITH A DEVELOPING CENTRAL US TROUGH AS A NORTHERN STREAM SHORTWAVE AND UPPER LOW EJECTING OUT OF THE ROCKIES PHASE...RESULTING IN AN UPSTREAM GRADUAL RISE IN HEIGHTS UP THE EASTERN SEABOARD. RESULTANT LOW PRESSURE TRACKS FROM THE CENTRAL PLAINS TO THE CENTRAL GREAT LAKES...WITH THE COLD FRONT TO THE SOUTH TONIGHT GRADUALLY WORKING NORTH TOWARDS THE AREA AS A WARM FRONT LATE THU/THU NIGHT. MEANWHILE...HIGH PRESSURE WILL ONLY SLOWLY RELENT ITS POSITION ACROSS THE CANADIAN MARITIMES AND DRIFT OFFSHORE. THE RESULT WILL BE A CONTINUATION OF STRATUS...PERIODS OF RAIN SHOWERS...AND AREAS OF DRIZZLE TONIGHT INTO THURSDAY WITH A BRISK AND CHILLY NE FLOW. WITH NORTHERN STREAM SHORTWAVE PASSING TO THE EAST BY THURSDAY MORNING...SHOWER ACTIVITY MAY BECOME LESS WIDESPREAD. THEN INCREASING CHANCE FOR SHOWER ACTIVITY LATE THURSDAY AND MORE SO THURSDAY NIGHT WITH STRONG WARM AIR ADVECTION PATTERN DEVELOPING OVER APPROACHING WARM FRONT. MOST WIDESPREAD DRIZZLE WILL LIKELY BE ACROSS AREAS NW AND W OF NYC WITH SOME OROGRAPHIC LIFT. HAVE ASSIGNED POPS BASED ON ABOVE THINKING. ALTHOUGH THERMAL PROFILES SUPPORT LIQUID PRECIPITATION FOR THE MOST PART...MODELS ARE INDICATING A DEVELOPING LOW-LEVEL COLD LAYER BETWEEN 975-900 MB AFTER MIDNIGHT INTO EARLY THURSDAY MORNING...WHICH COULD RESULT IN FREEZING RAIN ACROSS ELEVATIONS ABOVE 500-750 FT. IF STRENGTH OF COLD LAYER IS CLOSER TO NAM SOUNDINGS...POTENTIAL FOR A BIT OF SLEET ACROSS INTERIOR TONIGHT. WILL HOLD OFF ON ANY ADVISORIES FOR THE FREEZING RAIN AT THIS POINT WITH LIMITED COVERAGE...POTENTIAL FOR SLEET...AND MARGINALLY COLD CONDITIONS. HIGH TEMPS THURSDAY WILL LIKELY RUN 10-15 DEGREES BELOW SEASONABLE ONCE AGAIN (LOWER TO MID 40S)...WITH A CONTINUATION OF THE RAW CONDITIONS WITH GUSTY NE WINDS. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... OVERALL IN THE UPPER LEVELS...THE JET STREAM WILL BE NORTH OF THE REGION...MOVING INTO THE REGION FRIDAY NIGHT AND JUST SOUTH OF THE REGION FOR THE WEEKEND BEFORE RISING BACK NORTH EARLY NEXT WEEK. IN THE MID LEVELS...THE LONGWAVE RIDGE MOVES OFF THE EAST COAST THURSDAY NIGHT THROUGH FRIDAY. THERE IS AN EMBEDDED SUBTLE SHORTWAVE WITH A STREAK OF POSITIVE VORTICITY ADVECTION FRIDAY WHICH WILL HELP ENHANCE LIFT FOR SHOWERS AND POSSIBLE THUNDERSTORMS NEAR AREAS WHICH HAVE GREATER MAX TEMPS. A LARGER SHORTWAVE APPROACHES SATURDAY AND MOVES THROUGH LATE IN THE DAY WITH A LONGWAVE RIDGE SETTLING IN THEREAFTER. AT THE SURFACE...THE APPROACH OF A WARM FRONT ASSOCIATED WITH A PARENT LOW MOVING THROUGH THE GREAT LAKES FRIDAY NIGHT WILL KEEP A MILD AIR MASS IN PLACE. WARM AND MOIST AIR ADVECTION INCREASE GOING INTO FRIDAY ONCE THE WARM FRONT IS NORTH OF THE REGION. A PRETTY STEEP INVERSION WILL BE SET UP AROUND 925MB WHERE TEMPS COULD REACH AS HIGH AS 19 DEGREES CELSIUS. SOME UNCERTAINTY ON GROUND TEMPS AND HOW MUCH OF THE HIGHER TEMPS ABOVE MIX DOWN. THE SOUTHERLY FLOW THROUGHOUT THE ATMOSPHERE AND APPROACH OF A WARM FRONT SUGGEST AN ADVECTION FOG SETUP. INDICATED PATCHY FOG DEVELOPING THURSDAY NIGHT INTO FRIDAY AND THEN AREAS OF FOG FRIDAY ON THE WATERS WHICH WILL PROBABLY TAKE SOME TIME TO DISSIPATE THROUGH THE DAY. IT IS TOO EARLY TO INDICATE EXPLICITLY IN FORECAST...BUT THERE IS THE POSSIBILITY OF DENSE FOG. IN TERMS OF PRECIPITATION...MODELS HAVE SOME DISAGREEMENT WITH SHOWER DEVELOPMENT ALONG WARM FRONT BUT ENOUGH OF SIGNAL SUGGESTS SHOWERS OR DRIZZLE WILL BE LIKELY THURSDAY NIGHT INTO FRIDAY. THEN A LULL IN ACTIVITY WITH THE AREA BEING IN THE WARM SECTOR WITH A CHANCE OF SHOWERS...BEFORE LIKELY SHOWERS AND POSSIBLE THUNDERSTORMS MOVE ACROSS FRIDAY AFTERNOON INTO THE EVENING AHEAD OF A COLD FRONT. THE COLD FRONT MOVES ACROSS FRIDAY EVENING WITH HIGH PRESSURE TO THE WEST STARTING TO MOVE EAST. HOWEVER...IT WILL NOT BE THAT PROMINENT INITIALLY AS THE SHORTWAVE TROUGH AND A SECONDARY WEAK COLD FRONT MOVE ACROSS SATURDAY. MAINLY DRY CONDITIONS SATURDAY ARE ANTICIPATED BUT CANNOT RULE OUT A SHOWER ASSOCIATED WITH THE PASSAGE OF FRONT AND SHORTWAVE...PROBABLY ACROSS THE LOWER HUDSON VALLEY WHERE BETTER DYNAMICS ARE CONVEYED. DRY WEATHER FOR SUNDAY AND MONDAY WITH HIGH PRESSURE TAKING OVER. OVERALL...TEMPS LOOK TO BE A FEW DEGREES ABOVE NORMAL. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... HIGH PRESSURE REMAINS NORTHEAST OF THE REGION THROUGH TONIGHT. MEANWHILE...A STATIONARY FRONT REMAINS TO OUR SOUTH...WITH WAVES OF LOW PRESSURE RIDING ALONG IT. GENERALLY VFR THIS AFTERNOON. CIGS THEN FALL TO MVFR THIS EVENING...AND POSSIBLY IFR OVERNIGHT. CIGS THIS AFTERNOON WILL START OFF AROUND 3500-4500FT...FALLING TO AROUND 1000 FT AFTER MIDNIGHT. WINDS WILL GENERALLY REMAIN FROM THE EAST TO NORTHEAST 10 TO 15 KT WITH GUSTS INTO THE 20 KT RANGE. WIND GUSTS ARE EXPECTED TO DIMINISH AFTER 00Z AND SPEEDS WILL FALL TO 10 KT OR LESS. CIGS DO NOT IMPROVE MUCH DURING THE DAY THURSDAY. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE DUE TO CHANGES IN CEILING HEIGHTS. TIMING OF WIND SPEEDS AND GUSTS MAY BE OFF BY +/- 1-2 HOURS. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE DUE TO CHANGES IN CEILING HEIGHTS. TIMING OF WIND SPEEDS AND GUSTS MAY BE OFF BY +/- 1-2 HOURS. KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE DUE TO CHANGES IN CEILING HEIGHTS. TIMING OF WIND SPEEDS AND GUSTS MAY BE OFF BY +/- 1-2 HOURS. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE DUE TO CHANGES IN CEILING HEIGHTS. TIMING OF WIND SPEEDS AND GUSTS MAY BE OFF BY +/- 1-2 HOURS. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE DUE TO CHANGES IN CEILING HEIGHTS. TIMING OF WIND SPEEDS AND GUSTS MAY BE OFF BY +/- 1-2 HOURS. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE DUE TO CHANGES IN CEILING HEIGHTS. TIMING OF WIND SPEEDS AND GUSTS MAY BE OFF BY +/- 1-2 HOURS. .OUTLOOK FOR 18Z THURSDAY THROUGH SUNDAY... .THURSDAY-FRIDAY MORNING...MVFR DURING THE DAY...THEN IFR AT NIGHT IN PERIODS OF -RA/DZ. LLWS POSSIBLE S/E TERMINALS LATE THURSDAY NIGHT/FRIDAY MORNING. .FRIDAY AFTERNOON/NIGHT...MVFR OR LOWER IN SHRA AND SLIGHT CHANCE TSTMS INTO FRIDAY EVENING...THEN BECOMING VFR. NW WINDS G20-25KT POSSIBLE FROM MID FRIDAY EVENING ON. .SATURDAY...VFR. NW WINDS G15-20KT POSSIBLE DURING THE DAYLIGHT HOURS. .SUN-MON...VFR. && .MARINE... A TIGHTENING PRESSURE GRADIENT AS HIGH PRESSURE BUILDS INTO NEW ENGLAND AND A WEAK LOW DEVELOPS ALONG THE MID ATLANTIC COAST EXPECTED TO DEVELOP MARGINAL GALE CONDITIONS ON THE OCEAN WATERS AND SCA CONDITIONS OVER THE REMAINDER OF THE WATERS THIS MORNING...AND CONTINUING INTO THIS EVENING. A GRADUAL SLACKENING OF THE GRADIENT EXPECTED LATE TONIGHT INTO THU AS SURFACE WAVE DISSIPATES AND HIGH PRESSURE SLIDES FURTHER OFFSHORE. THIS SHOULD ALLOW GALE CONDITIONS TO FALL TO SCA ON THE OCEAN LATE THIS EVENING. SCA WINDS LIKELY CONTINUE ON THE OCEAN WATERS THRU THU...BUT LOWER CONFIDENCE ON THE NEARSHORE WATERS SEEING SCA CONDITIONS CONTINUE ON THU. OCEAN SEAS EXPECTED TO BUILD TO 6 TO 10 FT WITH LONG PERIOD EASTERLY SWELLS TODAY INTO TONIGHT...AND LIKELY SLOW TO SUBSIDE ON THU. SCA CONDITIONS FORECAST ON THE OCEAN MUCH OF THE PERIOD THURSDAY NIGHT THROUGH SATURDAY NIGHT. SCA CONDITIONS FORECAST FOR ALL WATERS SATURDAY. SUB SCA CONDITIONS FORECAST OVERALL FOR SUNDAY. && .HYDROLOGY... RAINFALL OF 1/10 TO 2/10 INCH EXPECTED THROUGH THU. RAINFALL OF AROUND 1/2 INCH LIKELY THU NIGHT THROUGH FRI NIGHT. HYDROLOGIC IMPACTS NOT EXPECTED. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB SITE. && .TIDES/COASTAL FLOODING... NE WINDS OF 15-25 KT TODAY INTO TONIGHT WILL HAVE WATER LEVELS APPROACHING MINOR FLOODING LEVELS ACROSS THE MOST VULNERABLE AREAS OF THE WESTERN GREAT SOUTH BAY DURING THE LATE TONIGHT HIGH TIDE CYCLE. THERE IS A LOW PROBABILITY THAT MINOR FLOODING THRESHOLDS ARE TOUCHED IN THESE AREAS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ338. SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ330-335- 340-345. GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR ANZ350-353-355. && $$ SYNOPSIS...GOODMAN/NV NEAR TERM...GOODMAN/NV SHORT TERM...NV LONG TERM...JM AVIATION...BC MARINE...GOODMAN/JM/NV HYDROLOGY...GOODMAN/JM/NV TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1051 AM EDT WED APR 8 2015 .SYNOPSIS... A NEARLY STATIONARY FRONT WILL REMAIN TO THE SOUTH THROUGH THURSDAY. LOW PRESSURE MOVES THROUGH THE GREAT LAKES WITH A WARM FRONT APPROACHING THURSDAY NIGHT. THE WARM FRONT PUSHES NORTHWEST OF THE REGION EARLY FRIDAY WITH LOW PRESSURE DEEPENING IN SOUTHEAST CANADA. AN ASSOCIATED COLD FRONT WILL MOVE ACROSS FRIDAY EVENING. A SECONDARY WEAK COLD FRONT MOVES ACROSS SATURDAY WITH HIGH PRESSURE FROM THE WEST BUILDING INTO THE REGION FOR THE REST OF THE WEEKEND. HIGH PRESSURE MOVES OFFSHORE EARLY NEXT WEEK AFTER WHICH LOW PRESSURE APPROACHES FROM THE WEST. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FOR THIS UPDATE HAVE CUT BACK SIGNIFICANTLY ON CHANCES OF RAIN OR DRIZZLE. COOL/DRY AIR DAMMING WEST EXTENDING SW FROM STRONG HIGH PRESSURE BUILDING ACROSS NEW ENGLAND...WITH THE OKX 12Z SOUNDING VERY DRY BELOW 900 MB...AND LOW LEVELS FCST TO REMAIN SO THROUGH MUCH OF TODAY AS THE DAMMING REMAINS IN PLACE. THIS DAMMING SHOULD SHUNT MOST OF THE PRECIP ASSOCIATED WITH A DEVELOPING WEAK LOW E OF THE VA CAPE...AND WEAKEN SHOWERS MOVING E FROM THE SUSQUEHANNA VALLEY IN PA. HRRR STILL DOES FCST SOME OF THIS ACTIVITY TO MAKE IT INTO AREAS WEST OF NYC THIS AFTERNOON...WITH MORE ISOLD ACTIVITY FARTHER EAST VIA MOISTURE AND WEAK H7-8 LIFT...SO STILL HAVE SLIGHT CHANCE POP THIS AFTERNOON FOR SRN CT AND LONG ISLAND. HIGH TEMPS TODAY WILL LIKELY RUN 10-15 DEGREES BELOW SEASONABLE TODAY...LOWER/MID 40S. COMBINED WITH NE WINDS OF 15 TO 20 MPH AND GUSTS TO 30 MPH ALONG THE COAST BETWEEN THE HIGH TO THE NORTH AND DEVELOPING LOW TO OUR SOUTH...IT WILL BE A RAW DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... MODELS IN GOOD AGREEMENT WITH A DEVELOPING CENTRAL US TROUGH AS A NORTHERN STREAM SHORTWAVE AND UPPER LOW EJECTING OUT OF THE ROCKIES PHASE...RESULTING IN AN UPSTREAM GRADUAL RISE IN HEIGHTS UP THE EASTERN SEABOARD. RESULTANT LOW PRESSURE TRACKS FROM THE CENTRAL PLAINS TO THE CENTRAL GREAT LAKES...WITH THE COLD FRONT TO THE SOUTH TONIGHT GRADUALLY WORKING NORTH TOWARDS THE AREA AS A WARM FRONT LATE THU/THU NIGHT. MEANWHILE...HIGH PRESSURE WILL ONLY SLOWLY RELENT ITS POSITION ACROSS THE CANADIAN MARITIMES AND DRIFT OFFSHORE. THE RESULT WILL BE A CONTINUATION OF STRATUS...PERIODS OF RAIN SHOWERS...AND AREAS OF DRIZZLE TONIGHT INTO THURSDAY WITH A BRISK AND CHILLY NE FLOW. WITH NORTHERN STREAM SHORTWAVE PASSING TO THE EAST BY THURSDAY MORNING...SHOWER ACTIVITY MAY BECOME LESS WIDESPREAD. THEN INCREASING CHANCE FOR SHOWER ACTIVITY LATE THURSDAY AND MORE SO THURSDAY NIGHT WITH STRONG WARM AIR ADVECTION PATTERN DEVELOPING OVER APPROACHING WARM FRONT. MOST WIDESPREAD DRIZZLE WILL LIKELY BE ACROSS AREAS NW AND W OF NYC WITH SOME OROGRAPHIC LIFT. HAVE ASSIGNED POPS BASED ON ABOVE THINKING. ALTHOUGH THERMAL PROFILES SUPPORT LIQUID PRECIPITATION FOR THE MOST PART...MODELS ARE INDICATING A DEVELOPING LOW-LEVEL COLD LAYER BETWEEN 975-900 MB AFTER MIDNIGHT INTO EARLY THURSDAY MORNING...WHICH COULD RESULT IN FREEZING RAIN ACROSS ELEVATIONS ABOVE 500-750 FT. IF STRENGTH OF COLD LAYER IS CLOSER TO NAM SOUNDINGS...POTENTIAL FOR A BIT OF SLEET ACROSS INTERIOR TONIGHT. WILL HOLD OFF ON ANY ADVISORIES FOR THE FREEZING RAIN AT THIS POINT WITH LIMITED COVERAGE...POTENTIAL FOR SLEET...AND MARGINALLY COLD CONDITIONS. HIGH TEMPS THURSDAY WILL LIKELY RUN 10-15 DEGREES BELOW SEASONABLE ONCE AGAIN (LOWER TO MID 40S)...WITH A CONTINUATION OF THE RAW CONDITIONS WITH GUSTY NE WINDS. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... OVERALL IN THE UPPER LEVELS...THE JET STREAM WILL BE NORTH OF THE REGION...MOVING INTO THE REGION FRIDAY NIGHT AND JUST SOUTH OF THE REGION FOR THE WEEKEND BEFORE RISING BACK NORTH EARLY NEXT WEEK. IN THE MID LEVELS...THE LONGWAVE RIDGE MOVES OFF THE EAST COAST THURSDAY NIGHT THROUGH FRIDAY. THERE IS AN EMBEDDED SUBTLE SHORTWAVE WITH A STREAK OF POSITIVE VORTICITY ADVECTION FRIDAY WHICH WILL HELP ENHANCE LIFT FOR SHOWERS AND POSSIBLE THUNDERSTORMS NEAR AREAS WHICH HAVE GREATER MAX TEMPS. A LARGER SHORTWAVE APPROACHES SATURDAY AND MOVES THROUGH LATE IN THE DAY WITH A LONGWAVE RIDGE SETTLING IN THEREAFTER. AT THE SURFACE...THE APPROACH OF A WARM FRONT ASSOCIATED WITH A PARENT LOW MOVING THROUGH THE GREAT LAKES FRIDAY NIGHT WILL KEEP A MILD AIR MASS IN PLACE. WARM AND MOIST AIR ADVECTION INCREASE GOING INTO FRIDAY ONCE THE WARM FRONT IS NORTH OF THE REGION. A PRETTY STEEP INVERSION WILL BE SET UP AROUND 925MB WHERE TEMPS COULD REACH AS HIGH AS 19 DEGREES CELSIUS. SOME UNCERTAINTY ON GROUND TEMPS AND HOW MUCH OF THE HIGHER TEMPS ABOVE MIX DOWN. THE SOUTHERLY FLOW THROUGHOUT THE ATMOSPHERE AND APPROACH OF A WARM FRONT SUGGEST AN ADVECTION FOG SETUP. INDICATED PATCHY FOG DEVELOPING THURSDAY NIGHT INTO FRIDAY AND THEN AREAS OF FOG FRIDAY ON THE WATERS WHICH WILL PROBABLY TAKE SOME TIME TO DISSIPATE THROUGH THE DAY. IT IS TOO EARLY TO INDICATE EXPLICITLY IN FORECAST...BUT THERE IS THE POSSIBILITY OF DENSE FOG. IN TERMS OF PRECIPITATION...MODELS HAVE SOME DISAGREEMENT WITH SHOWER DEVELOPMENT ALONG WARM FRONT BUT ENOUGH OF SIGNAL SUGGESTS SHOWERS OR DRIZZLE WILL BE LIKELY THURSDAY NIGHT INTO FRIDAY. THEN A LULL IN ACTIVITY WITH THE AREA BEING IN THE WARM SECTOR WITH A CHANCE OF SHOWERS...BEFORE LIKELY SHOWERS AND POSSIBLE THUNDERSTORMS MOVE ACROSS FRIDAY AFTERNOON INTO THE EVENING AHEAD OF A COLD FRONT. THE COLD FRONT MOVES ACROSS FRIDAY EVENING WITH HIGH PRESSURE TO THE WEST STARTING TO MOVE EAST. HOWEVER...IT WILL NOT BE THAT PROMINENT INITIALLY AS THE SHORTWAVE TROUGH AND A SECONDARY WEAK COLD FRONT MOVE ACROSS SATURDAY. MAINLY DRY CONDITIONS SATURDAY ARE ANTICIPATED BUT CANNOT RULE OUT A SHOWER ASSOCIATED WITH THE PASSAGE OF FRONT AND SHORTWAVE...PROBABLY ACROSS THE LOWER HUDSON VALLEY WHERE BETTER DYNAMICS ARE CONVEYED. DRY WEATHER FOR SUNDAY AND MONDAY WITH HIGH PRESSURE TAKING OVER. OVERALL...TEMPS LOOK TO BE A FEW DEGREES ABOVE NORMAL. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... HIGH PRESSURE BUILDS TO THE NORTH THEN NORTHEAST THROUGH TONIGHT. MEANWHILE...A STATIONARY FRONT REMAINS TO OUR SOUTH...WITH WAVES OF LOW PRESSURE RIDING ALONG IT. VFR...WITH CEILINGS GENERALLY BETWEEN 3500-6000FT TODAY. CEILINGS DECREASE TO MVFR LATE THIS AFTERNOON AND THIS EVENING...THEN TO IFR OVERNIGHT. NE-ENE WINDS 10-15KT AT CITY/CT/LONG ISLAND TERMINALS...SLIGHTLY LESS AT THE TERMINALS NORTH NYC. WINDS HAVE BECOME A BIT GUSTY WITH SPEEDS INTO THE UPPER TEENS AND LOWER 20S. WINDS BEGIN TO DIMINISH THIS AFTERNOON AT MOST TERMINALS...EXCEPTION IS COASTAL CT...WHERE WINDS INCREASE THIS EVENING...WITH GUSTS TO 25-30KT. PEAK GUSTS COULD BE UP TO 5 TO MAYBE 10 KT HIGHER THAN WHAT IS IN THE TAFS. WINDS THEN DIMINISH FROM MID-LATE EVENING ON...FAIRLY QUICKLY LOSING THEIR GUSTINESS. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE DUE TO CHANGES IN CEILINGS. TIMING OF CHANGES IN WIND SPEED...DIRECTION AND ON/OFFSET OF GUSTS COULD BE OFF +/- 2-3 HOURS. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE DUE TO CHANGES IN CEILINGS. TIMING OF CHANGES IN WIND SPEED...DIRECTION AND ON/OFFSET OF GUSTS COULD BE OFF +/- 2-3 HOURS. KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE DUE TO CHANGES IN CEILINGS. TIMING OF CHANGES IN WIND SPEED...DIRECTION AND ON/OFFSET OF GUSTS COULD BE OFF +/- 2-3 HOURS. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH IMPLIES SLANT RANGE VISIBILITY 4-6SM OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE DUE TO CHANGES IN CEILINGS. TIMING OF CHANGES IN WIND SPEED...DIRECTION AND ON/OFFSET OF GUSTS COULD BE OFF +/- 2-3 HOURS. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE DUE TO CHANGES IN CEILINGS. TIMING OF CHANGES IN WIND SPEED...DIRECTION AND ON/OFFSET OF GUSTS COULD BE OFF +/- 2-3 HOURS. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE DUE TO CHANGES IN CEILINGS. TIMING OF CHANGES IN WIND SPEED...DIRECTION AND ON/OFFSET OF GUSTS COULD BE OFF +/- 2-3 HOURS. .OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY... .THURSDAY-FRIDAY MORNING...MVFR TO VFR AT DAY...THEN MVFR TO IFR AT NIGHT IN PERIODS -RA/DZ. E-NE WINDS G15-20KT THURSDAY. LLWS POSSIBLE S/E TERMINALS LATE THURSDAY NIGHT/FRIDAY MORNING. .FRIDAY AFTERNOON/NIGHT...MVFR OR LOWER IN SHRA AND SLIGHT CHANCE TSTMS INTO FRIDAY EVENING...THEN BECOMING VFR. NW WINDS G20-25KT POSSIBLE FROM MID FRIDAY EVENING ON. .SATURDAY-SUNDAY...VFR. NW WINDS G15-20KT POSSIBLE DURING THE DAYLIGHT HOURS SATURDAY. && .MARINE... A TIGHTENING PRESSURE GRADIENT AS HIGH PRESSURE BUILDS INTO NEW ENGLAND AND A WEAK LOW DEVELOPS ALONG THE MID ATLANTIC COAST EXPECTED TO DEVELOP MARGINAL GALE CONDITIONS ON THE OCEAN WATERS AND SCA CONDITIONS OVER THE REMAINDER OF THE WATERS THIS MORNING...AND CONTINUING INTO THIS EVENING. A GRADUAL SLACKENING OF THE GRADIENT EXPECTED LATE TONIGHT INTO THU AS SURFACE WAVE DISSIPATES AND HIGH PRESSURE SLIDES FURTHER OFFSHORE. THIS SHOULD ALLOW GALE CONDITIONS TO FALL TO SCA ON THE OCEAN LATE THIS EVENING. SCA WINDS LIKELY CONTINUE ON THE OCEAN WATERS THRU THU...BUT LOWER CONFIDENCE ON THE NEARSHORE WATERS SEEING SCA CONDITIONS CONTINUE ON THU. OCEAN SEAS EXPECTED TO BUILD TO 6 TO 10 FT WITH LONG PERIOD EASTERLY SWELLS TODAY INTO TONIGHT...AND LIKELY SLOW TO SUBSIDE ON THU. SCA CONDITIONS FORECAST ON THE OCEAN MUCH OF THE PERIOD THURSDAY NIGHT THROUGH SATURDAY NIGHT. SCA CONDITIONS FORECAST FOR ALL WATERS SATURDAY. SUB SCA CONDITIONS FORECAST OVERALL FOR SUNDAY. && .HYDROLOGY... RAINFALL OF 1/10 TO 2/10 INCH EXPECTED THROUGH THU. RAINFALL OF AROUND 1/2 INCH LIKELY THU NIGHT THROUGH FRI NIGHT. HYDROLOGIC IMPACTS NOT EXPECTED. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB SITE. && .TIDES/COASTAL FLOODING... NE WINDS OF 15-25 KT TODAY INTO TONIGHT WILL HAVE WATER LEVELS APPROACHING MINOR FLOODING LEVELS ACROSS THE MOST VULNERABLE AREAS OF THE WESTERN GREAT SOUTH BAY DURING THE LATE TONIGHT HIGH TIDE CYCLE. THERE IS A LOW PROBABILITY THAT MINOR FLOODING THRESHOLDS ARE TOUCHED IN THESE AREAS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ338. SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ330-335- 340-345. GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR ANZ350-353-355. && $$ SYNOPSIS...GOODMAN/NV NEAR TERM...GOODMAN/NV SHORT TERM...NV LONG TERM...JM AVIATION...BC/MALOIT MARINE...GOODMAN/JM/NV HYDROLOGY...GOODMAN/JM/NV TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1046 AM EDT WED APR 8 2015 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH FRIDAY. A COLD FRONT WILL SHIFT THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY...THEN STALL SOUTH OF THE REGION ON SUNDAY BEFORE LIFTING BACK NORTH THROUGH THE AREA AS A WARM FRONT ON MONDAY. ATLANTIC HIGH PRESSURE WILL THEN PREVAIL THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LATE THIS MORNING...SKIES HAVE CLEARED OUT ACROSS THE FORECAST AREA AND PLENTIFUL SUNSHINE WILL PREVAIL INTO THE AFTERNOON. THE OVERALL SETUP CONTINUES TO LOOK A LOT LIKE SUMMER. ALOFT...THE REGION IS WITHIN THE BROAD RIDGE AXIS AND RELATIVELY WEAK WESTERLY FLOW. AT THE SURFACE...ATLANTIC HIGH PRESSURE PREVAILS WITH A RATHER BENIGN PATTERN. WITHIN THE BROADLY ANTICYCLONIC FLOW ALOFT...THE MODELS SHOW A CLEAR AREA OF NVA THAT CURRENTLY SITS ACROSS MUCH OF GEORGIA AND EASTERN ALABAMA. THIS WILL SLOWLY DRIFT EASTWARD TODAY...AND SHOULD HELP TO KEEP CONVECTIVE DEVELOPMENT AT A MINIMUM FOR MOST OF SOUTHEAST GEORGIA. FURTHER TO THE EAST...THERE IS A WEAK VORT MAX ON THE LEADING EDGE OF THE NVA...WHICH MAY HELP TO FOCUS CONVECTIVE DEVELOPMENT ACROSS INLAND PORTIONS OF THE TRI-COUNTY AND SOUTHEAST SOUTH CAROLINA. THERE SHOULD BE A ROBUST AND PROGRESSIVE SEA BREEZE THIS AFTERNOON WITH LAND TEMPERATURES REACHING THE MID 80S AND WATER TEMPERATURES IN THE MID 60S. THIS WILL HELP TO KEEP SHOWER/THUNDERSTORM DEVELOPMENT FURTHER INLAND AS WELL. CONCERNING THE THERMODYNAMIC ENVIRONMENT...TEMPERATURES REACHING THE MID/UPPER 80S WILL RESULT IN A MUCH MORE UNSTABLE AIRMASS THAN PREVIOUS DAYS. IN FACT...MODIFIED HRRR AND RAP SOUNDINGS GIVE CAPE VALUES ON THE ORDER OF 2000-2300 J/KG. THE COLUMN DRIES OUT A BIT TOO AND DCAPES ARE PROGGED TO BE IN EXCESS OF 1000 J/KG. LAPSE RATES STEEPEN TO AROUND -6 C/KM AND THERE IS A NICE SEPARATION BETWEEN THE FREEZING LEVEL AND THE WET BULB ZERO. SO...EVEN THOUGH COVERAGE WILL BE SCATTERED AT BEST...THERE IS THE POTENTIAL FOR A COUPLE OF STRONG TO SEVERE STORMS. IT APPEARS CONVECTIVE INITIATIONWILL BEGIN AROUND 19Z...AND POPS HAVE BEEN ADJUSTED TO CONTAIN THE CHANCES JUST TO THE TRI-COUNTY AND SOUTHEAST SOUTH CAROLINA AREA. WILL MAINTAIN THE MENTION IN THE HWO. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... TONIGHT...EARLY EVENING CONVECTION WILL DISSIPATE WELL INLAND WITH THE LOSS OF INSOLATION. WARM AND HUMID CONDITIONS WILL LINGER WITH LOWS FALLING INTO THE LOWER-MID 60S. COULD SEE ANOTHER AROUND OF PATCHY GROUND FOG IN SOME LOCATIONS...ESPECIALLY THAT RECEIVES RAINFALL THIS AFTERNOON...BUT THE FOG DOES NOT LOOK SIGNIFICANT ATTM. THURSDAY...THE AREA WILL REMAIN ALONG THE WESTERN EDGE OF ATLANTIC HIGH PRESSURE AND UNDER A MID LVL RIDGE OF HIGH PRESSURE EXTENDING NORTHWARD FROM THE GULF OF MEXICO. THE BULK OF PRECIP ACTIVITY SHOULD SHIFT SLIGHTLY MORE INLAND THAN PREVIOUS DAYS AS THE MID LVL RIDGE EXPANDS OVER THE AREA WELL AHEAD OF A LOW PRESSURE TROUGH DIGGING OVER THE CENTRAL UNITED STATES. THE PATTERN WILL RESULT IN WARM TEMPS...WITH HIGHS IN THE MID TO UPPER 80S OVER MOST LOCATIONS. TEMPS WILL REMAIN COOLER ALONG THE COAST GIVEN AN ONSHORE FLOW. SUFFICIENT HEATING AND MOISTURE WILL SUPPORT A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS AWAY FROM THE COAST...BUT ACTIVITY WILL LIKELY BE DRIVEN BY AN AFTERNOON SEABREEZE GIVEN THE LACK OF LARGER SCALE FORCING. EXPECT MOST PRECIP TO DIMINISH WITHIN A FEW HOURS OF SUNSET. OVERNIGHT LOWS SHOULD RANGE IN THE MID 60S. WE COULD SEE SOME PATCHY FOG DEVELOP LATE WHILE WINDS ARE LIGHT/CALM AND DEWPTS REMAIN IN THE MID 60S. FRIDAY...ANOTHER WARM DAY IS ANTICIPATED WELL AHEAD OF COLD FRONT THAT WILL MAKE WAY TO THE REGION LATE. EXPECT HIGH TEMPS TO WARM IN THE MID/UPPER 80S FOR MOST LOCATIONS...EVEN AS CLOUD COVER INCREASES FROM THE WEST. CHANCES OF SHOWERS AND/OR THUNDERSTORMS WILL BE POSSIBLE...ESPECIALLY LATE AS MOISTURE DEEPENS AND MID LVL FORCING BEGINS TO INCREASE ALONG AND AHEAD OF A SFC COLD FRONT MAKING WAY INTO THE AREA FRIDAY NIGHT. AT THIS TIME...THE THREAT OF SEVERE WEATHER REMAINS LOW GIVEN THE TIMING OF FROPA DURING THE OVERNIGHT PERIOD. HOWEVER...THERE IS A LOW CHANCE OF A FEW STRONGER THUNDERSTORMS GIVEN SBCAPES APPROACHING 1000-1250 J/KG AND 20-30 KT LOW/MID LVL WIND FIELDS SHIFTING OVER THE AREA FRIDAY EVENING. OVERNIGHT LOWS SHOULD REMAIN MILD UNTIL FROPA...IN THE MID 60S FOR MOST LOCATIONS SATURDAY...A COLD FRONT WILL PUSH THROUGH THE AREA EARLY WITH AT LEAST CHANCES OF SHOWERS AND/OR THUNDERSTORMS AS FROPA OCCURS. DRYER AND COOLER CONDITIONS WILL FOLLOW THE FRONT AS HIGH PRESSURE BUILDS IN FROM THE NORTH. OVERALL HIGH TEMPS SHOULD PEAK NEAR 80 FOR LOCATIONS AWAY FROM THE COAST...BUT WILL LIKELY BE ON A COOLING TREND BY MID AFTERNOON OVER NORTHERN AREAS WHERE SFC WINDS SHIFT TO NORTHEAST BEHIND THE FRONT. BY SATURDAY EVENING...MOST PRECIP ACTIVITY WILL LIKELY BE FOCUSED IN SOUTHEAST GEORGIA...WHERE THE FRONT CONTINUES A SOUTHWARD SHIFT BEFORE STALLING WELL SOUTH OF THE AREA. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... A WEAKENED/STALLED FRONT WILL BE POSITIONED SOUTH OF THE AREA THROUGH SUNDAY...WHILE A WEDGE OF HIGH PRESSURE BUILDS FROM THE NORTH. TEMPS WILL BE COOLER...WITH OVERALL HIGHS IN THE MID 70S OVER MOST LOCATIONS. A SLIGHT CHANCE TO CHANCE OF SHOWERS AND/OR THUNDERSTORMS WILL MAINLY BE CONFINED TO LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA THROUGH EARLY MONDAY. CHANCES OF SHOWERS AND THUNDERSTORMS SHOULD RETURN TO MOST AREAS ON MONDAY AS THE STALLED FRONT LIFTS BACK NORTH AS A WARM FRONT WELL AHEAD OF A DEEPENING LOW PRESSURE SYSTEM OVER THE CENTRAL UNITED STATES. HIGH TEMPS SHOULD THEN RETURN INTO THE 80S THROUGH THE MIDDLE OF NEXT WEEK AS THE AREA REMAINS SITUATED ALONG THE WESTERN EDGE OF ATLANTIC HIGH PRESSURE AND STRONG RIDGING ALOFT. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... VFR. STILL LOOKS LIKE THE BEST CHANCES FOR TSTMS WILL REMAIN WEST OF THE TERMINALS THIS AFTERNOON. EXTENDED AVIATION OUTLOOK...LOW CHANCES OF FLIGHT RESTRICTIONS THURSDAY AND FRIDAY WITH AFTERNOON SHOWERS AND/OR THUNDERSTORMS. FLIGHT RESTRICTION CHANCES INCREASE FRIDAY NIGHT INTO SATURDAY SATURDAY AS A COLD FRONT PASSES OVER BOTH TERMINALS. && .MARINE... THROUGH TONIGHT...SOUTHERLY WIND REGIME WILL PERSIST. WINDS WILL GENERALLY REMAIN 10 KT OR LESS WITH SEAS 2-4 FT. THURSDAY THROUGH MONDAY...CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH LATE WEEK ALONG THE WESTERN EDGE OF ATLANTIC HIGH PRESSURE. IN GENERAL...A SOUTHERLY WIND WILL REMAIN AT OR BELOW 15 KTS OUTSIDE DAILY SHOWERS AND/OR THUNDERSTORMS. BRIEF SURGES AND SLIGHT CHANGES IN WIND DIRECTION SHOULD OCCUR NEAR AFTERNOON SEABREEZE CIRCULATIONS. SEAS WILL BE NO HIGHER THAN 4 FT. WINDS/SEAS SHOULD THEN INCREASE/BUILD THIS WEEKEND AS A COLD FRONT APPROACHES FROM THE NORTHWEST FRIDAY...THEN SHIFTS OVER THE COASTAL WATERS FRIDAY NIGHT INTO EARLY SATURDAY. HOWEVER...CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS OUTSIDE THUNDERSTORM ACTIVITY. A FEW THUNDERSTORMS COULD BE STRONG DURING FROPA FRIDAY NIGHT. WINDS WILL SHIFT TO NORTH/NORTHEAST BEHIND THE FRONT AS IT STALLS SOUTH OF THE COASTAL WATERS SATURDAY NIGHT AND SUNDAY. THE STALLED FRONT IS THEN EXPECTED TO LIFT BACK NORTH AS A WARM FRONT ON MONDAY. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ NEAR TERM...BSH SHORT TERM...DPB LONG TERM...DPB AVIATION...ST MARINE...ST/DPB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
648 AM EDT WED APR 8 2015 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH FRIDAY. A COLD FRONT WILL SHIFT THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY...THEN STALL SOUTH OF THE REGION ON SUNDAY BEFORE LIFTING BACK NORTH THROUGH THE AREA AS A WARM FRONT ON MONDAY. ATLANTIC HIGH PRESSURE WILL THEN PREVAIL THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NO SIGNIFICANT CHANGES WERE MADE FOR THE SUNRISE UPDATE. A SPECIAL WEATHER STATEMENT HAS BEEN ISSUED TO ADDRESS AREAS OF FOG IN SOUTHEAST GEORGIA. THE SURFACE AND UPPER AIR SYNOPTIC PATTERN IS VERY REMINISCENT OF SUMMER WITH MEAN 500 HPA RIDING IN PLACE ACROSS THE SOUTHEAST U.S. WITH THE AREA POSITIONED ALONG THE WESTERN FLANKS OF ATLANTIC HIGH PRESSURE. CONVECTIVE DEBRIS CLOUDINESS EARLY THIS MORNING WILL GIVE WAY TO INCREASING INSOLATION THROUGH THE DAY...WHICH WILL EVENTUALLY YIELD A MODEST CUMULUS FIELD AHEAD OF THE DEVELOPING SEA BREEZE. THERE ARE NO APPARENT LOW-LEVEL TRIGGERS FOR CONVECTION TODAY EXCEPT THE RESULTANT SEA BREEZE CIRCULATION...WHICH IN ITSELF DOES NOT LOOK OVERLY STRONG...BUT CONVECTIVE OUTFLOWS ARE LIKELY LURKING ACROSS INLAND AREAS BASED ON EARLIER REFLECTIVITY DATA. THE 00Z MODELS ARE NOT OVERLY AGGRESSIVE WITH THE COVERAGE OF SHOWERS/TSTMS DURING PEAK HEATING...WHICH SEEMS PLAUSIBLE WITH WEAK DNVA NOTED IN THE WAKE OF SHORTWAVE ENERGY PASSING OFFSHORE THIS MORNING. DESPITE WEAK SUBSIDENCE...MODIFIED RAP SOUNDINGS DO SHOW MODEST INSTABILITY DEVELOPING THROUGH THE DAY AS TEMPERATURES RISE WELL INTO THE 80S WITH DEWPOINTS HOLDING IN THE LOWER-MID 60S. SUSPECT ISOLATED CONVECTION WILL INITIATE EITHER ALONG THE SEA BREEZE ITSELF OR MORE LIKELY ALONG THE LAKE BREEZE OR RESIDUAL CONVECTIVE OUTFLOW OVER INLAND AREAS BY EARLY-MID AFTERNOON WITH ADDITIONAL CONVECTIVE CLUSTERS DEVELOPING ALONG MESOSCALE BOUNDARY COLLISIONS...MAINLY INLAND AHEAD OF THE SEA BREEZE. POPS OF 20-30 PERCENT WILL BE MAINTAINED FOR LAND AREAS TODAY AND WITH TIMING AND PLACEMENT OF THE HIGHEST GRIDDED POPS BLENDED HEAVILY TOWARDS THE LATEST 4KM NSSL WRF. HIGHS WILL WARM INTO THE MID-UPPER 80S AWAY FROM THE BEACHES. AN ISOLATED STRONG OR SEVERE TSTM CAN NOT BE RULED OUT WITHIN A MODERATELY UNSTABLE ENVIRONMENT (SBCAPE 2600 J/KG...LIFTED INDEX -6C...SHOWALTER INDEX -2C...HCAPE ~900 J/KG WITH DCAPE 1200 J/KG PER MODIFIED KOGB RAP SOUNDING)...ESPECIALLY WHERE UPDRAFTS BECOME ENHANCED ALONG MESOSCALE BOUNDARY COLLISIONS. WBZ HEIGHTS REMAIN FAIRLY LOW FOR THE TIME YEAR AND 0-6KM BULK SHEAR IS FORECAST TO REMAIN 20-25 KT...WHICH IS JUST HIGH ENOUGH TO SUPPORT SOME LOOSELY ORGANIZED MULTICELLULAR CLUSTERS. WILL HIGHLIGHT ISOLATED STRONG TO SEVERE TSTMS IN THE HAZARDOUS WEATHER OUTLOOK. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... TONIGHT...EARLY EVENING CONVECTION WILL DISSIPATE WELL INLAND WITH THE LOSS OF INSOLATION. WARM AND HUMID CONDITIONS WILL LINGER WITH LOWS FALLING INTO THE LOWER-MID 60S. COULD SEE ANOTHER AROUND OF PATCHY GROUND FOG IN SOME LOCATIONS...ESPECIALLY THAT RECEIVES RAINFALL THIS AFTERNOON...BUT THE FOG DOES NOT LOOK SIGNIFICANT ATTM. THURSDAY...THE AREA WILL REMAIN ALONG THE WESTERN EDGE OF ATLANTIC HIGH PRESSURE AND UNDER A MID LVL RIDGE OF HIGH PRESSURE EXTENDING NORTHWARD FROM THE GULF OF MEXICO. THE BULK OF PRECIP ACTIVITY SHOULD SHIFT SLIGHTLY MORE INLAND THAN PREVIOUS DAYS AS THE MID LVL RIDGE EXPANDS OVER THE AREA WELL AHEAD OF A LOW PRESSURE TROUGH DIGGING OVER THE CENTRAL UNITED STATES. THE PATTERN WILL RESULT IN WARM TEMPS...WITH HIGHS IN THE MID TO UPPER 80S OVER MOST LOCATIONS. TEMPS WILL REMAIN COOLER ALONG THE COAST GIVEN AN ONSHORE FLOW. SUFFICIENT HEATING AND MOISTURE WILL SUPPORT A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS AWAY FROM THE COAST...BUT ACTIVITY WILL LIKELY BE DRIVEN BY AN AFTERNOON SEABREEZE GIVEN THE LACK OF LARGER SCALE FORCING. EXPECT MOST PRECIP TO DIMINISH WITHIN A FEW HOURS OF SUNSET. OVERNIGHT LOWS SHOULD RANGE IN THE MID 60S. WE COULD SEE SOME PATCHY FOG DEVELOP LATE WHILE WINDS ARE LIGHT/CALM AND DEWPTS REMAIN IN THE MID 60S. FRIDAY...ANOTHER WARM DAY IS ANTICIPATED WELL AHEAD OF COLD FRONT THAT WILL MAKE WAY TO THE REGION LATE. EXPECT HIGH TEMPS TO WARM IN THE MID/UPPER 80S FOR MOST LOCATIONS...EVEN AS CLOUD COVER INCREASES FROM THE WEST. CHANCES OF SHOWERS AND/OR THUNDERSTORMS WILL BE POSSIBLE...ESPECIALLY LATE AS MOISTURE DEEPENS AND MID LVL FORCING BEGINS TO INCREASE ALONG AND AHEAD OF A SFC COLD FRONT MAKING WAY INTO THE AREA FRIDAY NIGHT. AT THIS TIME...THE THREAT OF SEVERE WEATHER REMAINS LOW GIVEN THE TIMING OF FROPA DURING THE OVERNIGHT PERIOD. HOWEVER...THERE IS A LOW CHANCE OF A FEW STRONGER THUNDERSTORMS GIVEN SBCAPES APPROACHING 1000-1250 J/KG AND 20-30 KT LOW/MID LVL WIND FIELDS SHIFTING OVER THE AREA FRIDAY EVENING. OVERNIGHT LOWS SHOULD REMAIN MILD UNTIL FROPA...IN THE MID 60S FOR MOST LOCATIONS SATURDAY...A COLD FRONT WILL PUSH THROUGH THE AREA EARLY WITH AT LEAST CHANCES OF SHOWERS AND/OR THUNDERSTORMS AS FROPA OCCURS. DRYER AND COOLER CONDITIONS WILL FOLLOW THE FRONT AS HIGH PRESSURE BUILDS IN FROM THE NORTH. OVERALL HIGH TEMPS SHOULD PEAK NEAR 80 FOR LOCATIONS AWAY FROM THE COAST...BUT WILL LIKELY BE ON A COOLING TREND BY MID AFTERNOON OVER NORTHERN AREAS WHERE SFC WINDS SHIFT TO NORTHEAST BEHIND THE FRONT. BY SATURDAY EVENING...MOST PRECIP ACTIVITY WILL LIKELY BE FOCUSED IN SOUTHEAST GEORGIA...WHERE THE FRONT CONTINUES A SOUTHWARD SHIFT BEFORE STALLING WELL SOUTH OF THE AREA. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... A WEAKENED/STALLED FRONT WILL BE POSITIONED SOUTH OF THE AREA THROUGH SUNDAY...WHILE A WEDGE OF HIGH PRESSURE BUILDS FROM THE NORTH. TEMPS WILL BE COOLER...WITH OVERALL HIGHS IN THE MID 70S OVER MOST LOCATIONS. A SLIGHT CHANCE TO CHANCE OF SHOWERS AND/OR THUNDERSTORMS WILL MAINLY BE CONFINED TO LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA THROUGH EARLY MONDAY. CHANCES OF SHOWERS AND THUNDERSTORMS SHOULD RETURN TO MOST AREAS ON MONDAY AS THE STALLED FRONT LIFTS BACK NORTH AS A WARM FRONT WELL AHEAD OF A DEEPENING LOW PRESSURE SYSTEM OVER THE CENTRAL UNITED STATES. HIGH TEMPS SHOULD THEN RETURN INTO THE 80S THROUGH THE MIDDLE OF NEXT WEEK AS THE AREA REMAINS SITUATED ALONG THE WESTERN EDGE OF ATLANTIC HIGH PRESSURE AND STRONG RIDGING ALOFT. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... VFR. SHALLOW FOG AT KSAV WILL LINGER FOR ANOTHER HOUR BEFORE LIFTING. THIS MAY PRODUCE VARYING VSBYS...BUT THE FOG LAYER LOOKS RATHER THIN PER WEBCAMS. STILL LOOKS LIKE THE BEST CHANCES FOR TSTMS WILL REMAIN WEST OF THE TERMINALS THIS AFTERNOON. EXTENDED AVIATION OUTLOOK...LOW CHANCES OF FLIGHT RESTRICTIONS THURSDAY AND FRIDAY WITH AFTERNOON SHOWERS AND/OR THUNDERSTORMS. FLIGHT RESTRICTION CHANCES INCREASE FRIDAY NIGHT INTO SATURDAY SATURDAY AS A COLD FRONT PASSES OVER BOTH TERMINALS. && .MARINE... THROUGH TONIGHT...SOUTHERLY WIND REGIME WILL PERSIST. WINDS WILL GENERALLY REMAIN 10 KT OR LESS WITH SEAS 2-4 FT. THURSDAY THROUGH MONDAY...CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH LATE WEEK ALONG THE WESTERN EDGE OF ATLANTIC HIGH PRESSURE. IN GENERAL...A SOUTHERLY WIND WILL REMAIN AT OR BELOW 15 KTS OUTSIDE DAILY SHOWERS AND/OR THUNDERSTORMS. BRIEF SURGES AND SLIGHT CHANGES IN WIND DIRECTION SHOULD OCCUR NEAR AFTERNOON SEABREEZE CIRCULATIONS. SEAS WILL BE NO HIGHER THAN 4 FT. WINDS/SEAS SHOULD THEN INCREASE/BUILD THIS WEEKEND AS A COLD FRONT APPROACHES FROM THE NORTHWEST FRIDAY...THEN SHIFTS OVER THE COASTAL WATERS FRIDAY NIGHT INTO EARLY SATURDAY. HOWEVER...CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS OUTSIDE THUNDERSTORM ACTIVITY. A FEW THUNDERSTORMS COULD BE STRONG DURING FROPA FRIDAY NIGHT. WINDS WILL SHIFT TO NORTH/NORTHEAST BEHIND THE FRONT AS IT STALLS SOUTH OF THE COASTAL WATERS SATURDAY NIGHT AND SUNDAY. THE STALLED FRONT IS THEN EXPECTED TO LIFT BACK NORTH AS A WARM FRONT ON MONDAY. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ ST/DPB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
416 AM EDT WED APR 8 2015 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH FRIDAY. A COLD FRONT WILL SHIFT THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY...THEN STALL SOUTH OF THE REGION ON SUNDAY BEFORE LIFTING BACK NORTH THROUGH THE AREA AS A WARM FRONT ON MONDAY. ATLANTIC HIGH PRESSURE WILL THEN PREVAIL THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... THROUGH SUNRISE...THE REMNANTS OF A SEVERE QLCS...WHICH MOVED THROUGH THE SOUTH CAROLINA MIDLANDS YESTERDAY EVENING...WILL SLOWLY DISSIPATE ACROSS BERKELEY AND UPPER CHARLESTON COUNTIES OVER THE NEXT FEW HOURS. THE CONVECTIVE OUTFLOW GENERATED BY THE QLCS CAN BE SEEN ON KCLX RADAR REFLECTIVITY DATA DROPPING SLOWLY SOUTH-SOUTHEAST AND COULD PROVIDE A FOCUS FOR ADDITIONAL ISOLATED SHOWERS/TSTMS THROUGH 5 AM...MAINLY ACROSS THE CHARLESTON TRI- COUNTY AREA EVEN AS THE PARENT CONVECTIVE STEADILY DIES OUT. A RISK FOR SHALLOW GROUND FOG REMAINS...MAINLY ACROSS SOUTHEAST GEORGIA WHERE SURFACE DEWPOINTS ARE RUNNING A BIT HIGHER. KCLX VAD WIND PROFILE DATA SUGGEST MECHANICAL MIXING IS LIKELY OCCURRING ATOP THE NOCTURNAL INVERSION WITH 1000 FT WINDS RUNNING ABOUT 30 KT. THIS WILL LIKELY PREVENT ANY FOG THAT DEVELOPS FROM BECOMING TOO WIDESPREAD OR DENSE. WILL CONTINUE TO HIGHLIGHT PATCHY FOG THROUGH 12Z. TODAY...THE SURFACE AND UPPER AIR SYNOPTIC PATTERN IS VERY REMINISCENT OF SUMMER WITH MEAN 500 HPA RIDING IN PLACE ACROSS THE SOUTHEAST U.S. WITH THE AREA POSITIONED ALONG THE WESTERN FLANKS OF ATLANTIC HIGH PRESSURE. CONVECTIVE DEBRIS CLOUDINESS EARLY THIS MORNING WILL GIVE WAY TO INCREASING INSOLATION THROUGH THE DAY...WHICH WILL EVENTUALLY YIELD A MODEST CUMULUS FIELD AHEAD OF THE DEVELOPING SEA BREEZE. THERE ARE NO APPARENT LOW-LEVEL TRIGGERS FOR CONVECTION TODAY EXCEPT THE RESULTANT SEA BREEZE CIRCULATION...WHICH IN ITSELF DOES NOT LOOK OVERLY STRONG...BUT CONVECTIVE OUTFLOWS ARE LIKELY LURKING ACROSS INLAND AREAS BASED ON EARLIER REFLECTIVITY DATA. THE 00Z MODELS ARE NOT OVERLY AGGRESSIVE WITH THE COVERAGE OF SHOWERS/TSTMS DURING PEAK HEATING...WHICH SEEMS PLAUSIBLE WITH WEAK DNVA NOTED IN THE WAKE OF SHORTWAVE ENERGY PASSING OFFSHORE THIS MORNING. DESPITE WEAK SUBSIDENCE...MODIFIED RAP SOUNDINGS DO SHOW MODEST INSTABILITY DEVELOPING THROUGH THE DAY AS TEMPERATURES RISE WELL INTO THE 80S WITH DEWPOINTS HOLDING IN THE LOWER-MID 60S. SUSPECT ISOLATED CONVECTION WILL INITIATE EITHER ALONG THE SEA BREEZE ITSELF OR MORE LIKELY ALONG THE LAKE BREEZE OR RESIDUAL CONVECTIVE OUTFLOW OVER INLAND AREAS BY EARLY-MID AFTERNOON WITH ADDITIONAL CONVECTIVE CLUSTERS DEVELOPING ALONG MESOSCALE BOUNDARY COLLISIONS...MAINLY INLAND AHEAD OF THE SEA BREEZE. POPS OF 20-30 PERCENT WILL BE MAINTAINED FOR LAND AREAS TODAY AND WITH TIMING AND PLACEMENT OF THE HIGHEST GRIDDED POPS BLENDED HEAVILY TOWARDS THE LATEST 4KM NSSL WRF. HIGHS WILL WARM INTO THE MID-UPPER 80S AWAY FROM THE BEACHES. AN ISOLATED STRONG OR SEVERE TSTM CAN NOT BE RULED OUT WITHIN A MODERATELY UNSTABLE ENVIRONMENT (SBCAPE 2600 J/KG...LIFTED INDEX -6C...SHOWALTER INDEX -2C...HCAPE ~900 J/KG WITH DCAPE 1200 J/KG PER MODIFIED KOGB RAP SOUNDING)...ESPECIALLY WHERE UPDRAFTS BECOME ENHANCED ALONG MESOSCALE BOUNDARY COLLISIONS. WBZ HEIGHTS REMAIN FAIRLY LOW FOR THE TIME YEAR AND 0-6KM BULK SHEAR IS FORECAST TO REMAIN 20-25 KT...WHICH IS JUST HIGH ENOUGH TO SUPPORT SOME LOOSELY ORGANIZED MULTICELLULAR CLUSTERS. WILL HIGHLIGHT ISOLATED STRONG TO SEVERE TSTMS IN THE HAZARDOUS WEATHER OUTLOOK. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... TONIGHT...EARLY EVENING CONVECTION WILL DISSIPATE WELL INLAND WITH THE LOSS OF INSOLATION. WARM AND HUMID CONDITIONS WILL LINGER WITH LOWS FALLING INTO THE LOWER-MID 60S. COULD SEE ANOTHER AROUND OF PATCHY GROUND FOG IN SOME LOCATIONS...ESPECIALLY THAT RECEIVES RAINFALL THIS AFTERNOON...BUT THE FOG DOES NOT LOOK SIGNIFICANT ATTM. THURSDAY...THE AREA WILL REMAIN ALONG THE WESTERN EDGE OF ATLANTIC HIGH PRESSURE AND UNDER A MID LVL RIDGE OF HIGH PRESSURE EXTENDING NORTHWARD FROM THE GULF OF MEXICO. THE BULK OF PRECIP ACTIVITY SHOULD SHIFT SLIGHTLY MORE INLAND THAN PREVIOUS DAYS AS THE MID LVL RIDGE EXPANDS OVER THE AREA WELL AHEAD OF A LOW PRESSURE TROUGH DIGGING OVER THE CENTRAL UNITED STATES. THE PATTERN WILL RESULT IN WARM TEMPS...WITH HIGHS IN THE MID TO UPPER 80S OVER MOST LOCATIONS. TEMPS WILL REMAIN COOLER ALONG THE COAST GIVEN AN ONSHORE FLOW. SUFFICIENT HEATING AND MOISTURE WILL SUPPORT A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS AWAY FROM THE COAST...BUT ACTIVITY WILL LIKELY BE DRIVEN BY AN AFTERNOON SEABREEZE GIVEN THE LACK OF LARGER SCALE FORCING. EXPECT MOST PRECIP TO DIMINISH WITHIN A FEW HOURS OF SUNSET. OVERNIGHT LOWS SHOULD RANGE IN THE MID 60S. WE COULD SEE SOME PATCHY FOG DEVELOP LATE WHILE WINDS ARE LIGHT/CALM AND DEWPTS REMAIN IN THE MID 60S. FRIDAY...ANOTHER WARM DAY IS ANTICIPATED WELL AHEAD OF COLD FRONT THAT WILL MAKE WAY TO THE REGION LATE. EXPECT HIGH TEMPS TO WARM IN THE MID/UPPER 80S FOR MOST LOCATIONS...EVEN AS CLOUD COVER INCREASES FROM THE WEST. CHANCES OF SHOWERS AND/OR THUNDERSTORMS WILL BE POSSIBLE...ESPECIALLY LATE AS MOISTURE DEEPENS AND MID LVL FORCING BEGINS TO INCREASE ALONG AND AHEAD OF A SFC COLD FRONT MAKING WAY INTO THE AREA FRIDAY NIGHT. AT THIS TIME...THE THREAT OF SEVERE WEATHER REMAINS LOW GIVEN THE TIMING OF FROPA DURING THE OVERNIGHT PERIOD. HOWEVER...THERE IS A LOW CHANCE OF A FEW STRONGER THUNDERSTORMS GIVEN SBCAPES APPROACHING 1000-1250 J/KG AND 20-30 KT LOW/MID LVL WIND FIELDS SHIFTING OVER THE AREA FRIDAY EVENING. OVERNIGHT LOWS SHOULD REMAIN MILD UNTIL FROPA...IN THE MID 60S FOR MOST LOCATIONS SATURDAY...A COLD FRONT WILL PUSH THROUGH THE AREA EARLY WITH AT LEAST CHANCES OF SHOWERS AND/OR THUNDERSTORMS AS FROPA OCCURS. DRYER AND COOLER CONDITIONS WILL FOLLOW THE FRONT AS HIGH PRESSURE BUILDS IN FROM THE NORTH. OVERALL HIGH TEMPS SHOULD PEAK NEAR 80 FOR LOCATIONS AWAY FROM THE COAST...BUT WILL LIKELY BE ON A COOLING TREND BY MID AFTERNOON OVER NORTHERN AREAS WHERE SFC WINDS SHIFT TO NORTHEAST BEHIND THE FRONT. BY SATURDAY EVENING...MOST PRECIP ACTIVITY WILL LIKELY BE FOCUSED IN SOUTHEAST GEORGIA...WHERE THE FRONT CONTINUES A SOUTHWARD SHIFT BEFORE STALLING WELL SOUTH OF THE AREA. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... A WEAKENED/STALLED FRONT WILL BE POSITIONED SOUTH OF THE AREA THROUGH SUNDAY...WHILE A WEDGE OF HIGH PRESSURE BUILDS FROM THE NORTH. TEMPS WILL BE COOLER...WITH OVERALL HIGHS IN THE MID 70S OVER MOST LOCATIONS. A SLIGHT CHANCE TO CHANCE OF SHOWERS AND/OR THUNDERSTORMS WILL MAINLY BE CONFINED TO LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA THROUGH EARLY MONDAY. CHANCES OF SHOWERS AND THUNDERSTORMS SHOULD RETURN TO MOST AREAS ON MONDAY AS THE STALLED FRONT LIFTS BACK NORTH AS A WARM FRONT WELL AHEAD OF A DEEPENING LOW PRESSURE SYSTEM OVER THE CENTRAL UNITED STATES. HIGH TEMPS SHOULD THEN RETURN INTO THE 80S THROUGH THE MIDDLE OF NEXT WEEK AS THE AREA REMAINS SITUATED ALONG THE WESTERN EDGE OF ATLANTIC HIGH PRESSURE AND STRONG RIDGING ALOFT. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... KCHS...TSTMS EAST OF KOGB ARE POISED TO REMAIN NORTH OF THE KCHS TERMINAL...BUT WATCHING FOR POSSIBLE REDEVELOPING ALONG THE SOUTHWARD FLANKING CONVECTIVE OUTFLOW BOUNDARY THAT IS APPROACHING KMKS-KDYB. OTHERWISE VFR. SMALL CHANCE FOR SHALLOW GROUND FOG TO IMPACT THE TERMINAL RIGHT AT SUNRISE...BUT IMPACTS LOOK MINIMAL AT BEST. SEA BREEZE WILL PASS ROUGHLY 18Z WITH A BRIEF PERIOD OF ELEVATED WINDS. BEST TSTM CHANCES THIS AFTERNOON WILL REMAIN WEST OF THE TERMINAL. KSAV...WATCHING FOR SHALLOW GROUND FOG DEVELOPMENT OVER THE NEXT FEW HOURS. DEWPOINTS REMAIN ELEVATED...BUT THERE MAY BE JUST ENOUGH MIXING ATOP THE BOUNDARY LAYER TO PREVENT WIDESPREAD FOG. SHORT TERM GUIDANCE HAS BACK OFF CONSIDERABLY ON THE FOG POTENTIAL AND THE 06Z TAF WILL REFLECT THIS. WILL HIGHLIGHT 4SM MIFG SCT004 BEGINNING AT 09-13Z WITH A TEMPO GROUP JUST BEFORE SUNRISE OF 2SM MIFG. WILL NOT MENTION PREVAILING IFR ATTM. OTHERWISE VFR. SEA BREEZE WILL PASS THE TERMINAL ROUGHLY 19Z WITH A BRIEF PERIOD OF ELEVATED WINDS. BEST TSTMS CHANCES THIS AFTERNOON WILL REMAIN WEST OF THE TERMINAL. EXTENDED AVIATION OUTLOOK...LOW CHANCES OF FLIGHT RESTRICTIONS THURSDAY AND FRIDAY WITH AFTERNOON SHOWERS AND/OR THUNDERSTORMS. FLIGHT RESTRICTION CHANCES INCREASE FRIDAY NIGHT INTO SATURDAY SATURDAY AS A COLD FRONT PASSES OVER BOTH TERMINALS. && .MARINE... THROUGH TONIGHT...SOUTHERLY WIND REGIME WILL PERSIST. WINDS WILL GENERALLY REMAIN 10 KT OR LESS WITH SEAS 2-4 FT. THURSDAY THROUGH MONDAY...CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH LATE WEEK ALONG THE WESTERN EDGE OF ATLANTIC HIGH PRESSURE. IN GENERAL...A SOUTHERLY WIND WILL REMAIN AT OR BELOW 15 KTS OUTSIDE DAILY SHOWERS AND/OR THUNDERSTORMS. BRIEF SURGES AND SLIGHT CHANGES IN WIND DIRECTION SHOULD OCCUR NEAR AFTERNOON SEABREEZE CIRCULATIONS. SEAS WILL BE NO HIGHER THAN 4 FT. WINDS/SEAS SHOULD THEN INCREASE/BUILD THIS WEEKEND AS A COLD FRONT APPROACHES FROM THE NORTHWEST FRIDAY...THEN SHIFTS OVER THE COASTAL WATERS FRIDAY NIGHT INTO EARLY SATURDAY. HOWEVER...CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS OUTSIDE THUNDERSTORM ACTIVITY. A FEW THUNDERSTORMS COULD BE STRONG DURING FROPA FRIDAY NIGHT. WINDS WILL SHIFT TO NORTH/NORTHEAST BEHIND THE FRONT AS IT STALLS SOUTH OF THE COASTAL WATERS SATURDAY NIGHT AND SUNDAY. THE STALLED FRONT IS THEN EXPECTED TO LIFT BACK NORTH AS A WARM FRONT ON MONDAY. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ ST/DPB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1222 AM EDT WED APR 8 2015 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH FRIDAY. A COLD FRONT COULD APPROACH FROM THE NORTHWEST ON SATURDAY OR SUNDAY. A STRONGER COLD FRONT COULD APPROACH THE SOUTHEAST BY TUESDAY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... MESOSCALE UPDATE...QLCS CONTINUE TO MARCH EAST EARLY THIS MORNING WITH RECENT KCLX RADAR TRENDS SUGGESTING SOME SOUTHERN DEVELOPMENT ALONG THE EMERGING OUTFLOW. SOME OF THIS ACTIVITY IS POISED TO IMPACT THE CHARLESTON TRI-COUNTY AREA...ESPECIALLY BERKELEY COUNTY...OVER THE NEXT FEW HOURS. HAVE ADJUSTED POPS ACCORDINGLY BY RAISING GRIDDED POPS IN THE LIKELY CATEGORY FOR NORTHERN BERKELEY. 08/06Z RAP SOUNDING AT SAINT STEPHEN WAS NOT OVERLY UNSTABLE...BUT THE APPROACHING QLCS APPEARS TO HAVE A WELL- DEFINED COLD POOL THAT IS HELPING TO DRIVE THE STORMS EAST AND SOUTHEAST. SO AN ISOLATED SEVERE TSTM CAN NOT BE RULED OUT. THE STORMS DO APPEAR TO HAVE GUSTED OUT...OR AT LEAST IN THE PROCESS OF GUSTING OUT...SO ITS UNCLEAR IF THIS ACTIVITY WILL REACH THE CHARLESTON COUNTY COAST. CONVECTIVE TRENDS ARE BEING MONITORED. && .SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/... WEDNESDAY AND THURSDAY WILL BE ALMOST SUMMERLIKE AS THE LOW LEVELS ARE DOMINATED BY HIGH PRESSURE STRETCHING FROM BERMUDA ACROSS THE WESTERN ATLANTIC TO THE SOUTHEAST COAST...WHILE AN UPPER RIDGE SETS UP SHOP OVER THE SOUTHEAST. 925 MB TEMPS OF NEAR 20C OVER THE INTERIOR EACH DAY WILL MIX DOWN SO MAX TEMPS WILL REACH WELL INTO THE 80S...WITH THE USUAL 10 OR MORE DEGREES COOLER AT THE BEACHES DUE TO AFTERNOON ONSHORE FLOW. THE MAIN FOCUS FOR ANY SHOWERS OR THUNDERSTORMS WILL BE THE SEA BREEZE BOUNDARY AS IT MOVES INLAND DURING THE AFTERNOON...BUT THE LACK OF A SYNOPTIC SCALE FORCING MECHANISM...ALONG WITH MIDDLING LAPSE RATES FROM 700-500 MB...SUGGEST THE ACTIVITY WILL ONLY SCATTERED IN NATURE. AFTER ANY INLAND EVENING CONVECTION DIES OFF...TEMPS WILL ONLY DROP DOWN TO THE 60S. I THINK THERE WILL ALSO BE SOME PATCHY FOG AROUND EARLY THURSDAY MORNING AS THE PRESSURE GRADIENT RELAXES AND DEWPOINTS REACH CLIMATOLOGICALLY FAVORABLE LEVELS. ON FRIDAY...A COLD FRONT WILL APPROACH FROM THE NORTHWEST DURING THE DAY. THE CWA SHOULD STAY ON THE WARM SIDE OF THE FRONT DURING THE DAY...BUT AN INCREASE IN CLOUD COVER SHOULD KEEP MAX TEMPS A COUPLE OF DEGREES COOLER THAN THURSDAY AFTERNOON. ADDITIONALLY...AS HEIGHTS BEGIN TO FALL ALOFT AND A MODEST JET NOSES IN FROM THE WEST...THERE WILL BE A LITTLE BETTER CHANCE FOR AFTERNOON CONVECTION. CURRENT POPS MAY CURRENTLY A LITTLE LOW...BUT THERE IS STILL SOME QUESTIONS ABOUT THE TIMING OF THE FRONT...SO I DID NOT WANT TO JUMP TOO HIGH THIS FAR IN ADVANCE. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... A COLD FRONT WILL APPROACH FROM THE WEST/NORTHWEST BEFORE STALLING OVER OR NEAR THE AREA THIS WEEKEND...BRINGING AN INCREASE IN SHOWER AND THUNDERSTORM ACTIVITY TO THE AREA. THE STALLED BOUNDARY SHOULD TAKE ON A MORE EAST/WEST ORIENTATION SATURDAY AND SUNDAY...WHILE A WEDGE OF HIGH PRESSURE TRIES TO SET UP OVER THE MID ATLANTIC STATES...PERHAPS REACHING THE TRI-COUNTY AREA INTO EARLY NEXT WEEK. THE POSITION OF THE STALLED BOUNDARY AND THE WEDGE OF HIGH PRESSURE WILL HAVE A LARGE IMPACT ON THE THERMAL GRADIENT OVER THE AREA...WITH TEMPS REACHING THE LOW 70S IN NORTHERN AREAS TO AROUND 80 ON SUNDAY. THE STALLED BOUNDARY SHOULD THEN LIFT NORTH ON MONDAY AHEAD OF ANOTHER LARGE AND STRONGER TROUGH OF LOW PRESSURE DIGGING OVER THE CENTRAL UNITED STATES. HIGH TEMPS SHOULD ONCE AGAIN WARM INTO THE LOWER 80S OVER MOST AREAS BEFORE A STRONGER COLD FRONT SWEEPS THROUGH THE AREA WITH SHOWERS AND/OR THUNDERSTORMS. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... WILL CONTINUE TO ASSESS PROGRESS OF A THUNDERSTORM COMPLEX ADVANCING E/SE THROUGH THE MIDLANDS. THUNDERSTORMS ARE STILL EXPECTED TO REMAIN NORTH OF THE REGION...BUT THERE IS A LOW PROBABILITY FOR SHOWERS/THUNDERSTORMS TO DEVELOP INTO THE I-26 CORRIDOR...PERHAPS IMPACTING KCHS AFTER 06Z. WILL AMEND FORECASTS AS NEEDED. OTHERWISE...VFR THIS EVENING. FLIGHT RESTRICTIONS IN FOG ARE LIKELY OVERNIGHT INTO EARLY WEDNESDAY...MOST LIKELY MVFR WITH A CHANCE FOR IFR OR LOWER AT KCHS AND OCCASIONALLY IFR WITH A CHANCE FOR LIFR AT KSAV. EXTENDED AVIATION OUTLOOK...FOG COULD AGAIN PRODUCE FLIGHT RESTRICTIONS LATE WEDNESDAY NIGHT INTO EARLY THURSDAY. SLIGHT CHANCE FOR FLIGHT RESTRICTIONS DUE TO CONVECTION THURSDAY...WITH MOST ACTIVITY OCCURRING INLAND OF THE TERMINALS. THE CHANCES INCREASE A LITTLE FRIDAY AFTERNOON WITH BETTER CONVECTIVE COVERAGE EXPECTED...BUT THE DURATION SHOULD NOT BE LONG. THE OTHER POTENTIAL PROBLEM IS PATCHY GROUND FOG AT THE TERMINALS. THIS SEEMS MOST LIKELY THURSDAY MORNING...AND POSSIBLY FRIDAY MORNING IF THE APPROACHING COLD FRONT IS A LITTLE SLOWER...BUT CHANCES ARE NOT MUCH BETTER THAN AVERAGE AT THIS POINT. && .MARINE... OVERNIGHT...A WEAK PRESSURE PATTERN WILL TRANSLATE TO S/SE WINDS VEERING TO S/SW AT 10 KT OR LESS. SEAS 2-3 FT WITHIN 20 NM AND 3-4 FT BEYOND WILL BE DOMINATED BY AN 8-10 SECOND EASTERLY SWELL. WEDNESDAY THROUGH FRIDAY...WITH HIGH PRESSURE DOMINATING THE WESTERN ATLANTIC...WINDS WILL BE GENERALLY OUT OF THE SOUTH TO SOUTHWEST THROUGH THE PERIOD...WITH DIRECTION BACKING TO ONSHORE DURING THE AFTERNOONS. SPEEDS WILL BE 15 KNOTS OR LESS WITH SEAS 3 FEET OR LESS...ALTHOUGH THEY MAY APPROACH 4 FEET BEYOND 40 NM NEAR THE GULF STREAM AT NIGHT. SATURDAY AND SUNDAY...WINDS/SEAS SHOULD THEN INCREASE/BUILD THIS WEEKEND AS A COLD FRONT APPROACHES FROM THE WEST AND STALLS OVER OR NEAR THE AREA...BUT EXPECT CONDITIONS TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS INTO EARLY NEXT WEEK. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ ST
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1023 PM CDT THU APR 9 2015 .MESOSCALE DISCUSSION...809 PM CDT LONG TRACK CYCLIC TORNADIC SUPERCELL OVER NORTHERN MCHENRY COUNTY HAS CROSSED NORTH OF THE WARM FRONT ACCORDING TO MESONET OBS AND THE TORNADO THREAT HAS GREATLY DIMINISHED. ANOTHER SUPERCELL IS QUICKLY ORGANIZING AND INTENSIFYING OVER SOUTHERN MCHENRY COUNTY AND IS EXHIBITING STRENGTHENING ROTATION ALOFT. HIGH DEWPOINTS NOT ALLOWING FOR MUCH DIURNAL COOLING SO STORM IS EITHER BOUNDARY LAYER ROOTED OR DARN CLOSE. GIVEN THE EXTREME LOW LEVEL SHEAR WITH 50KT WINDS LESS THAN 1K FT AGL TORNADO POTENTIAL WILL BE VERY CLOSELY MONITORES FOR SOUTHERN MCHENRY STORM. IZZI && .SHORT TERM... 400 AM CDT TODAY AND TONIGHT... DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY ALONG THE LAKE AS ISSUED. CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID- UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE AREA THIS AFTERNOON AND EVENING. WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN BEFORE MIDNIGHT AFTER FROPA. RATZER && .LONG TERM... 257 PM CDT FRIDAY THROUGH THURSDAY... FOLLOWING A PERIOD OF VERY ACTIVE WEATHER...FOLLOWING THE PASSAGE OF THE COLD FRONT LATE THURSDAY NIGHT...A PERIOD OF RELATIVE CALM WILL SET UP FOR FRIDAY INTO SUNDAY AS A COOL...DRY HIGH PRESSURE AREA BUILDS ACROSS THE AREA. TEMPERATURES WILL DROP BACK TO CLOSER TO SEASONAL HIGHS NORMAL LEVELS WITH HIGHS IN THE UPPER 50S TO AROUND 60F UNDER MOSTLY SUNNY SKIES. AS THE HIGH WILL BE RIGHT OVER THE AREA FRIDAY NIGHT INTO SATURDAY MORNING...LIGHT WINDS AND A DRY AIRMASS WILL ALLOW FOR SOME ENHANCED RADIATIVE COOLING OVERNIGHT FOR LOWS TO DROP BACK INTO THE MIDDLE TO UPPER 30S SATURDAY MORNING. WITH THE HIGH BEGINNING TO BUILD OFF TO THE EAST THROUGH SATURDAY NIGHT AND SUNDAY...A RETURN FLOW OF MOISTURE AND WARMER AIR WILL KEEP THE COOLING TREND VERY BRIEF WITH TEMPS REBOUNDING BACK TO AROUND 60F OVER MUCH OF THE CWA...WITH THE EXCEPTION OF THE IMMEDIATE LAKEFRONT...WHICH SHOULD REMAIN COOLER AS A WEAK PRESSURE GRADIENT AND DIFFERENTIAL HEATING BETWEEN THE COOL LAKE WATER AND WARMER LAKE SHOULD ALLOW A LAKE BREEZE TO DEVELOP. HIGHS ON SATURDAY ALONG THE LAKE FRONT TOPPING OUT IN THE MIDDLE 50S. INCREASING SOUTHERLY FLOW ON THE WESTERN PERIPHERY OF THE HIGH MOVING OFF TO THE EAST WILL LIKELY PREVENT A LAKE BREEZE FROM DEVELOPING. FOR SUNDAY...A NORTHERN STREAM SHORT WAVE MOVING OUT OF THE NRN ROCKIES SHOULD BEGIN TO PHASE WITH A SOUTHERN STREAM SHORTWAVE LIFTING INTO THE MIDDLE MISSISSIPPI VALLEY. THIS PHASING SHOULD RESULT IN AN AMPLIFYING LONG WAVE TROUGH OVER THE MIDDLE AND UPPER MISSISSIPPI VALLEY AND BRINGING THE NEXT CHANCE OF PCPN TO THE REGION. THE LONGER RANGE GUIDANCE...IN GENERAL...AGREE ON THE SCENARIO...BUT DIFFERENCES IN THE TIMING OF THE INDIVIDUAL SHORTWAVE AND THE DEGREE OF PHASING AND THE RESULTANT STRENGTH OF THE LONG WAVE TROUGH LEAD TO A RELATIVELY LOW CONFIDENCE FORECAST FOR THE LATTER PORTIONS OF THE EXTENDED FORECAST PERIOD. CURRENTLY FEEL THAT A COLD FRONT MOVING ACROSS THE AREA SUNDAY INTO SUNDAY NIGHT AND THEN SHUTTING OFF BY MONDAY MORNING AS ANOTHER HIGH PRESSURE SYSTEM MOVES ACROSS THE AREA. WHILE THERE IS MODERATE TO HIGH CONFIDENCE IN A PERIOD OF PCPN SUNDAY AND SUNDAY NIGHT...START AND END TIMES REMAIN UNCERTAIN AS WELL AS THE CHANCES FOR THUNDERSTORMS WITH THE PCPN AND WILL LIKELY BE HIGHLY DEPENDENT ON THE SPEED OF AN ASSOCIATED COLD FRONT MOVING THROUGH THE AREA. FOR THE LATTER PORTIONS OF THE FORECAST PERIOD...FROM TUESDAY THROUGH THURSDAY...THERE COULD BE ANOTHER PERIOD OF UNSETTLED WEATHER AS THE UPPER LEVEL FLOW PATTERN MAINTAINS A HIGH AMPLITUDE...QUICKLY PROGRESSIVE PATTERN. THE GFS/ECMWF ARE ACTUALLY SHOWING BETTER CONSISTENCY FOR THE END OF THE LONGER TERM FORECAST PERIOD THAN EARLIER...WITH ANOTHER LONG WAVE TROUGH DEVELOPING OVER THE CNTRL PLAINS. THE ECMWF IS TRENDING A BIT STRONGER AND DEVELOPING MORE OF A NEGATIVE TILT TO THE TROUGH AND A CLOSED UPPER LOW BY WEDNESDAY NIGHT...THE GFS IS REMARKABLY SIMILAR...BUT ABOUT 24 HOURS SLOWER IN DEVELOPING THE NEGATIVE TILT UPPER TROUGH AND CLOSED UPPER LOW. SHOULD THIS SCENARIO PAN OUT...THE MIDDLE OF NEXT WEAK COULD BE RIPE FOR ANOTHER PERIOD OF ACTIVE WEATHER. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * MVFR CIGS/OCCASIONAL IFR CIGS OVERNIGHT. * GUSTY WINDS BCMG SW TO W ARND MIDNIGHT WITH MAX GUSTS AROUND 45 KT. SUSTAINED WINDS OF 25-27 KT LATE THIS EVENING AND OVERNIGHT. GUSTY W WINDS THROUGH THE DAY FRIDAY. KMD //DISCUSSION...UPDATED 03Z... STRONG THUNDERSTORMS WILL CONTINUE EAST INTO NW INDIANA AND OVER LAKE MICHIGAN THIS EVENING. MAIN HAZARDS ARE CONTINUOUS LIGHTNING...GUSTY WINDS TO 45 MPH...AND SMALL HAIL. THESE SHOULD REMAIN EAST OF ALL TERMINALS FROM A PEOTONE TO SOUTH CHICAGO LINE. MAIN NEAR TERM CONCERN IS GUSTY SW WINDS BEHIND THESE STORMS. EXPECT A PERIOD OF SUSTAINED WINDS 25-30 KT AND GUSTS TO 45 KT THROUGH THE EARLY MORNING HOURS...DIMINISHING SOME BUT REMAINING GUSTY OUT OF THE WEST FRIDAY. AFTER THESE STORMS CLEAR...EXPECT CIGS LOWERING TO MVFR AND POSSIBLY IFR. LIFTING IS EXPECTED FRIDAY MORNING BUT CONTINUED GUSTY WINDS. KMD //ORD AND MDW CONFIDENCE...UPDATED 03Z... * HIGH CONFIDENCE IN LOWER CIGS TONIGHT...MEDIUM ON SPECIFIC HEIGHTS AND LOW ON HOW LONG ANY IFR WILL LAST. * MEDIUM/HIGH CONFIDENCE IN WIND GUSTS OVERNIGHT AND TOMORROW...THOUGH LOWER/MEDIUM CONFIDENCE ON SPECIFIC SPEEDS ON FRIDAY. KMD //OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z... * SATURDAY...DRY/VFR. SOUTHWEST WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...DRY/VFR. GUSTY SOUTH WINDS. * MONDAY...DRY/VFR. EAST WINDS. * TUESDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS. * WEDNESDAY...CHANCE OF SHRA. SOUTH WINDS. && .MARINE... 315 PM CDT CONDITIONS OVER LAKE MICHIGAN ARE DETERIORATING RAPIDLY TODAY...FIRST WITH WAVES OF THUNDERSTORMS CROSSING THE SOUTHERN PORTIONS OF THE LAKE AS A WARM FRONT LIFTS NORTHWARD. AS OF 3PM CDT...THE FRONT HAD MOVED UP TO THE CENTER OF THE LAKE AND SHOULD CONTINUE TO LIFT NORTHWARD AS DEEPENING LOW PRESSURE OVER EASTERN IOWA CONTINUES TO DEEPEN AND TRACKS INTO SOUTHERN WISCONSIN BY EARLY THIS EVENING. BY THIS POINT...THE SOUTHERLY FLOW WILL REACH ALMOST TO THE NORTH END OF THE LAKE...BUT WITH STRONG PRESSURE FALLS AND A STRENGTHENING PRESSURE GRADIENT OVER THE LAKE AS THE SFC LOW APPROACHES...WINDS OVER THE SRN PORTIONS OF THE LAKE SHOULD INCREASE TO GALE FORCE FOR THE NEARSHORE WATERS AND THE SOUTH HALF OF THE LAKE. THUNDERSTORMS WILL ALSO CONTINUE TO BE A CONCERN INTO THE EVENING AS WELL. THE SFC LOW IS EXPECTED TO TRACK ACROSS THE CNTRL PORTIONS OF THE LAKE LATE THIS EVENING...WITH WINDS QUICKLY SHIFTING TO WLY-NWLY. A STRONG NORTHERLY GRADIENT BEHIND THE EXITING LOW...INCREASING COLD ADVECTION ASSOCIATED WITH A COOL HIGH PRESSURE SYSTEM DROPPING INTO THE NRN PLAINS AND STRONG PRESSURE RISES AS A RESULT OF THE COMBINATION OF THE EXITING LOW AND APPROACHING HIGH...SHOULD ALL COMBINE TO BRING SHORT PERIOD OF WEST TO NWLY GALES TO THE LAKE INTO FRIDAY AFTERNOON. THE APPROACHING HIGH SHOULD BEGIN TO OVERSPREAD THE WESTERN GREAT LAKES BY FRIDAY AFTERNOON...ALLOWING WINDS OVER THE LAKE TO DROP OFF RELATIVELY QUICKLY. FOR THE WEEKEND AND INTO EARLY NEXT WEEK...CONDITIONS OVER THE LAKE SHOULD BE RELATIVELY QUIET. ANOTHER COLD FRONT IS EXPECTED TO SWEEP ACROSS THE LAKE SUNDAY NIGHT OR MONDAY...BUT THIS SHOULD BE A LESS DYNAMIC SYSTEM...AND WINDS SHOULD NOT GET AS STRONG AS WITH THE SYSTEM APPROACHING THE LAKE AT THE CURRENT TIME. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777- LMZ779 UNTIL 1 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 854 PM CDT Thu Apr 9 2015 .UPDATE... ISSUED AT 854 PM CDT THU APR 9 2015 Vigorous shortwave and jet streak are pushing a cold front rapidly across IL. They have triggered strong to severe storms with isolated tornadoes this afternoon/evening. Remaining storms seem to be evolving into more outflow dominated storms, but will continue to monitor for any localized rotations the next couple hours. Storms and cold front are projected to be east of our IL counties by 11 pm, with strong west-southwest winds in their wake. Sustained winds behind the front will increase to 20 mph and gust to 35 mph at times. A brief period of clearing skies may follow the front for an hour or so, but low clouds will return for 6-8 hours the rest of the night. Clear skies will return from west to east around sunrise tomorrow, with gusty winds continuing. Low temps will drop about 20 degrees colder than last night, with readings in the mid to upper 40s toward sunrise. Likewise, highs on Friday will be around 15-18F colder than today, but still in the low 60s. Updated the weather and PoP forecasts to match expected trends, with minor adjustments to clouds cover timing. Updated info will be available by 9 pm. && .SHORT TERM...(Tonight) ISSUED AT 307 PM CDT THU APR 9 2015 19z/2pm surface analysis shows 998mb low centered over southeast Iowa, with cold front trailing southward into western Missouri. Line of convection is rapidly developing along the front within the moderately unstable and uncapped airmass in the warm sector. 0-6km bulk shear values will be on the increase as the afternoon progresses as a mid-level short-wave approaches from the west, resulting in continued convective intensification. HRRR has had a good handle on the situation throughout the day, with its latest iteration agreeing closely with prior runs. Based on satellite timing tools and HRRR guidance, it appears the line of storms will cross the Mississippi River by 23z/6pm, then will track through the Illinois River Valley and to the I-55 corridor by about 02z/8pm. Damaging wind gusts will be the primary threat, but large hail and a few tornadoes will be possible as well. As the storms move further east, they will likely congeal into a solid line and the tornado threat will diminish accordingly. Once the front passes, windy and cooler weather will be on tap overnight with a slow west to east clearing trend by dawn. && .LONG TERM...(Friday through Thursday) ISSUED AT 307 PM CDT THU APR 9 2015 Morning upper air shows a potential severe event this afternoon and evening, as main upper level shortwave and vort max over southwest NE at 12z will be rotating to the east. Low level thermal ridge and moisture axis extends into MO/IL ahead of the approaching front. low level jet is particularly strong flowing into MO/western IL and so ample shear available in warm sector. HRRR model and NAM a little slower on the movement of the front through the region, going through this evening. Shear with strong upper jet and low level southern jet will make severe potential with severe storms possible on the cold front as it sweeps through. Deepening surface low to move northeast into eastern IA and then southern WI. High pressure in control until weak front moves in and brings showers on late Sunday and Sunday night. Another chance off showers Tuesday into Thursday. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) ISSUED AT 700 PM CDT THU APR 9 2015 Line of storms firing along a cold front will produce heavy rain, hail and possible tornadoes. Lower chances that any terminal site will get hit directly by any severe weather, but still possible. Target window should be 2 hours as the line moves through, so we continued with 2hr tempos for heavy rain and MVFR vis/cig. Upstream obs and satellite images show a break in the MVFR cigs should follow the line, before MVFR clouds return in wrap-around moisture behind the low pressure system. Will continue MVFR clouds until 10z at PIA, then advance clearing eastward into Friday morning. Strong winds will continue both ahead of the front and behind. Wind direction will remain SW ahead of the front, with gusts to 30kt, then become west later tonight. Gusts will increase to 25-30kt tomorrow as mid level jet winds continue to be strong. && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH until 1 AM CDT Friday FOR ILZ054>057-061>063- 066>068-071>073. && $$ UPDATE...Shimon SHORT TERM...Barnes LONG TERM...Goetsch AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
718 PM CDT THU APR 9 2015 .MESOSCALE DISCUSSION...536 PM CDT CONTINUE TO MONITOR COLD FRONT WITH STRONG CONVECTION OCCURRING NEAR THE MISSISSIPPI RIVER THIS HOUR. AHEAD OF THE FRONT WITHIN THE WARM SECTOR THUNDERSTORMS HAVE STRUGGLED TO REACH THEIR FULL POTENTIAL WITH MODEST MID LEVEL LAPSE RATES BEING ONE OF THE PRIMARY LIMITING FACTORS. WIDELY SCATTERED ACTIVITY WILL CONTINUE AHEAD OF THE FRONT THROUGH MID EVENING...THOUGH GIVEN TRENDS SO FAR THE THREAT FOR SEVERE WEATHER APPEARS LOW AHEAD OF THE FRONT. WITH CIRRUS SHIELD OVERSPREADING THE REGION AND LOWERING SUN ANGLE...THERE ARE RENEWED CONCERNS REGARDING INSTABILITY...ESPECIALLY AS WE GET CLOSER TO SUNSET THIS EVENING. EXPECT MODERATE INSTABILITY TO PERSIST THROUGH 00Z THEN FOR A DIMINISHING TREND OF MLCAPE THEREAFTER. BY 00Z/7PM CDT...EXPECT THE LINE OF THUNDERSTORMS ASSOCIATED WITH THE COLD FRONT WHICH WILL MAINTAIN A HIGHER SEVERE THREAT TO BE NEAR THE I-39 CORRIDOR...AND ENTERING THE WESTERN SUBURBS OF CHICAGO CLOSER TO 01Z/8PM CDT. LOW LEVEL CONVERGENCE ALONG THE FRONT REMAINS STRONG AND DEEP LAYER SHEAR REMAINS SUFFICIENT TO SUSTAIN AT LEAST SOME ORGANIZED/SEVERE THREAT THROUGH THE HEART OF THE FORECAST AREA...THOUGH DIMINISHING MLCAPE MAY EVENTUALLY LOWER THAT THREAT. DEUBELBEISS && .SHORT TERM... 400 AM CDT TODAY AND TONIGHT... DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY ALONG THE LAKE AS ISSUED. CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID- UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE AREA THIS AFTERNOON AND EVENING. WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN BEFORE MIDNIGHT AFTER FROPA. RATZER && .LONG TERM... 257 PM CDT FRIDAY THROUGH THURSDAY... FOLLOWING A PERIOD OF VERY ACTIVE WEATHER...FOLLOWING THE PASSAGE OF THE COLD FRONT LATE THURSDAY NIGHT...A PERIOD OF RELATIVE CALM WILL SET UP FOR FRIDAY INTO SUNDAY AS A COOL...DRY HIGH PRESSURE AREA BUILDS ACROSS THE AREA. TEMPERATURES WILL DROP BACK TO CLOSER TO SEASONAL HIGHS NORMAL LEVELS WITH HIGHS IN THE UPPER 50S TO AROUND 60F UNDER MOSTLY SUNNY SKIES. AS THE HIGH WILL BE RIGHT OVER THE AREA FRIDAY NIGHT INTO SATURDAY MORNING...LIGHT WINDS AND A DRY AIRMASS WILL ALLOW FOR SOME ENHANCED RADIATIVE COOLING OVERNIGHT FOR LOWS TO DROP BACK INTO THE MIDDLE TO UPPER 30S SATURDAY MORNING. WITH THE HIGH BEGINNING TO BUILD OFF TO THE EAST THROUGH SATURDAY NIGHT AND SUNDAY...A RETURN FLOW OF MOISTURE AND WARMER AIR WILL KEEP THE COOLING TREND VERY BRIEF WITH TEMPS REBOUNDING BACK TO AROUND 60F OVER MUCH OF THE CWA...WITH THE EXCEPTION OF THE IMMEDIATE LAKEFRONT...WHICH SHOULD REMAIN COOLER AS A WEAK PRESSURE GRADIENT AND DIFFERENTIAL HEATING BETWEEN THE COOL LAKE WATER AND WARMER LAKE SHOULD ALLOW A LAKE BREEZE TO DEVELOP. HIGHS ON SATURDAY ALONG THE LAKE FRONT TOPPING OUT IN THE MIDDLE 50S. INCREASING SOUTHERLY FLOW ON THE WESTERN PERIPHERY OF THE HIGH MOVING OFF TO THE EAST WILL LIKELY PREVENT A LAKE BREEZE FROM DEVELOPING. FOR SUNDAY...A NORTHERN STREAM SHORT WAVE MOVING OUT OF THE NRN ROCKIES SHOULD BEGIN TO PHASE WITH A SOUTHERN STREAM SHORTWAVE LIFTING INTO THE MIDDLE MISSISSIPPI VALLEY. THIS PHASING SHOULD RESULT IN AN AMPLIFYING LONG WAVE TROUGH OVER THE MIDDLE AND UPPER MISSISSIPPI VALLEY AND BRINGING THE NEXT CHANCE OF PCPN TO THE REGION. THE LONGER RANGE GUIDANCE...IN GENERAL...AGREE ON THE SCENARIO...BUT DIFFERENCES IN THE TIMING OF THE INDIVIDUAL SHORTWAVE AND THE DEGREE OF PHASING AND THE RESULTANT STRENGTH OF THE LONG WAVE TROUGH LEAD TO A RELATIVELY LOW CONFIDENCE FORECAST FOR THE LATTER PORTIONS OF THE EXTENDED FORECAST PERIOD. CURRENTLY FEEL THAT A COLD FRONT MOVING ACROSS THE AREA SUNDAY INTO SUNDAY NIGHT AND THEN SHUTTING OFF BY MONDAY MORNING AS ANOTHER HIGH PRESSURE SYSTEM MOVES ACROSS THE AREA. WHILE THERE IS MODERATE TO HIGH CONFIDENCE IN A PERIOD OF PCPN SUNDAY AND SUNDAY NIGHT...START AND END TIMES REMAIN UNCERTAIN AS WELL AS THE CHANCES FOR THUNDERSTORMS WITH THE PCPN AND WILL LIKELY BE HIGHLY DEPENDENT ON THE SPEED OF AN ASSOCIATED COLD FRONT MOVING THROUGH THE AREA. FOR THE LATTER PORTIONS OF THE FORECAST PERIOD...FROM TUESDAY THROUGH THURSDAY...THERE COULD BE ANOTHER PERIOD OF UNSETTLED WEATHER AS THE UPPER LEVEL FLOW PATTERN MAINTAINS A HIGH AMPLITUDE...QUICKLY PROGRESSIVE PATTERN. THE GFS/ECMWF ARE ACTUALLY SHOWING BETTER CONSISTENCY FOR THE END OF THE LONGER TERM FORECAST PERIOD THAN EARLIER...WITH ANOTHER LONG WAVE TROUGH DEVELOPING OVER THE CNTRL PLAINS. THE ECMWF IS TRENDING A BIT STRONGER AND DEVELOPING MORE OF A NEGATIVE TILT TO THE TROUGH AND A CLOSED UPPER LOW BY WEDNESDAY NIGHT...THE GFS IS REMARKABLY SIMILAR...BUT ABOUT 24 HOURS SLOWER IN DEVELOPING THE NEGATIVE TILT UPPER TROUGH AND CLOSED UPPER LOW. SHOULD THIS SCENARIO PAN OUT...THE MIDDLE OF NEXT WEAK COULD BE RIPE FOR ANOTHER PERIOD OF ACTIVE WEATHER. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * SCATTERED STORMS EXPECTED THIS AFTN...WITH THE FINAL ROUND OF STORMS MOVING THROUGH ARND 2Z-4Z. SOME OF THESE STORMS COULD BE SEVERE WITH GUSTY WINDS. * GUSTY SSW WINDS WITH GUSTS ARND 25 KT. * IFR VSBY EXPECTED WITH TSRA. * IFR CIGS BEHIND THE LINE OF STORMS OVER NIGHT...BECOMING MVFR * GUSTY WINDS BCMG SW TO W ARND MIDNIGHT WITH MAX GUSTS 30-35 KT. KMD //DISCUSSION...UPDATED 00Z... STRONGEST THUNDERSTORM ACTIVITY IS IN THE NORTHWEST CORNER OF THE COUNTY WARNING AREA THIS EVENING...WITH A BROKEN LINE OF STORMS EXTENDING SOUTH THROUGH WESTERN ILLINOIS EARLY THIS EVENING. ADDITIONALLY...SOME ISOLATED THUNDESTORMS EXIST OUT AHEAD OF THE MAIN LINE. WHILE THE LINE FARTHER WEST IS NOT COMPLETELY FILLED IN YET...AS THE COLD FRONT MAKES EASTWARD PROGRESS...EXPECT THIS LINE TO BECOME FILLED IN...REACHING THE CHICAGOLAND TERMINALS AROUND 145-2Z. EXPECT SCATTERED THUNDERSTORMS OUT AHEAD OF THIS MAIN LINE. EXPECT HAIL...STRONG WINDS...AND HEAVY RAIN WITH THESE STORMS WHEN THEY DO FILL IN. CONFIDENCE IS STILL MEDIUM ON THE TIMING AND COVERAGE. AFTER THESE STORMS CLEAR...EXPECT GUSTY WSW WINDS WITH CIGS LOWERING TO MVFR AND POSSIBLY IFR. LIFTING IS EXPECTED FRIDAY MORNING BUT CONTINUED GUSTY WINDS. KMD //ORD AND MDW CONFIDENCE...UPDATED 00Z... * HIGH CONFIDENCE IN SCATTERED STORMS EARLY THIS EVENING FOLLOWED BY A SEGMENT OR SEMI-BROKEN LINE OF STORMS LATER THIS EVENING. MEDIUM CONFIDENCE IN COVERAGE THIS EVENING AND TIMING. * MEDIUM CONFIDENCE IN WIND DIRECTION BEHIND THE SCATTERED STORMS. WINDS COULD BE CHAOTIC FOR A BRIEF PERIOD OF TIME. * HIGH CONFIDENCE IN REDUCED VSBY UNDER STORMS...MEDIUM-LOW CONFIDENCE IN CIG HEIGHTS. * HIGH CONFIDENCE IN LOWER CIGS TONIGHT...LOW ON SPECIFIC HEIGHTS AND HOW LONG IFR WILL LAST. * MEDIUM CONFIDENCE IN WIND GUSTS OVERNIGHT AND TOMORROW...GUSTS COULD BE HIGHER. KMD //OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z... * SATURDAY...DRY/VFR. SOUTHWEST WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...DRY/VFR. GUSTY SOUTH WINDS. * MONDAY...DRY/VFR. EAST WINDS. * TUESDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS. * WEDNESDAY...CHANCE OF SHRA. SOUTH WINDS. && .MARINE... 315 PM CDT CONDITIONS OVER LAKE MICHIGAN ARE DETERIORATING RAPIDLY TODAY...FIRST WITH WAVES OF THUNDERSTORMS CROSSING THE SOUTHERN PORTIONS OF THE LAKE AS A WARM FRONT LIFTS NORTHWARD. AS OF 3PM CDT...THE FRONT HAD MOVED UP TO THE CENTER OF THE LAKE AND SHOULD CONTINUE TO LIFT NORTHWARD AS DEEPENING LOW PRESSURE OVER EASTERN IOWA CONTINUES TO DEEPEN AND TRACKS INTO SOUTHERN WISCONSIN BY EARLY THIS EVENING. BY THIS POINT...THE SOUTHERLY FLOW WILL REACH ALMOST TO THE NORTH END OF THE LAKE...BUT WITH STRONG PRESSURE FALLS AND A STRENGTHENING PRESSURE GRADIENT OVER THE LAKE AS THE SFC LOW APPROACHES...WINDS OVER THE SRN PORTIONS OF THE LAKE SHOULD INCREASE TO GALE FORCE FOR THE NEARSHORE WATERS AND THE SOUTH HALF OF THE LAKE. THUNDERSTORMS WILL ALSO CONTINUE TO BE A CONCERN INTO THE EVENING AS WELL. THE SFC LOW IS EXPECTED TO TRACK ACROSS THE CNTRL PORTIONS OF THE LAKE LATE THIS EVENING...WITH WINDS QUICKLY SHIFTING TO WLY-NWLY. A STRONG NORTHERLY GRADIENT BEHIND THE EXITING LOW...INCREASING COLD ADVECTION ASSOCIATED WITH A COOL HIGH PRESSURE SYSTEM DROPPING INTO THE NRN PLAINS AND STRONG PRESSURE RISES AS A RESULT OF THE COMBINATION OF THE EXITING LOW AND APPROACHING HIGH...SHOULD ALL COMBINE TO BRING SHORT PERIOD OF WEST TO NWLY GALES TO THE LAKE INTO FRIDAY AFTERNOON. THE APPROACHING HIGH SHOULD BEGIN TO OVERSPREAD THE WESTERN GREAT LAKES BY FRIDAY AFTERNOON...ALLOWING WINDS OVER THE LAKE TO DROP OFF RELATIVELY QUICKLY. FOR THE WEEKEND AND INTO EARLY NEXT WEEK...CONDITIONS OVER THE LAKE SHOULD BE RELATIVELY QUIET. ANOTHER COLD FRONT IS EXPECTED TO SWEEP ACROSS THE LAKE SUNDAY NIGHT OR MONDAY...BUT THIS SHOULD BE A LESS DYNAMIC SYSTEM...AND WINDS SHOULD NOT GET AS STRONG AS WITH THE SYSTEM APPROACHING THE LAKE AT THE CURRENT TIME. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777- LMZ779 UNTIL 1 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 712 PM CDT Thu Apr 9 2015 .SHORT TERM...(Tonight) ISSUED AT 307 PM CDT THU APR 9 2015 19z/2pm surface analysis shows 998mb low centered over southeast Iowa, with cold front trailing southward into western Missouri. Line of convection is rapidly developing along the front within the moderately unstable and uncapped airmass in the warm sector. 0-6km bulk shear values will be on the increase as the afternoon progresses as a mid-level short-wave approaches from the west, resulting in continued convective intensification. HRRR has had a good handle on the situation throughout the day, with its latest iteration agreeing closely with prior runs. Based on satellite timing tools and HRRR guidance, it appears the line of storms will cross the Mississippi River by 23z/6pm, then will track through the Illinois River Valley and to the I-55 corridor by about 02z/8pm. Damaging wind gusts will be the primary threat, but large hail and a few tornadoes will be possible as well. As the storms move further east, they will likely congeal into a solid line and the tornado threat will diminish accordingly. Once the front passes, windy and cooler weather will be on tap overnight with a slow west to east clearing trend by dawn. && .LONG TERM...(Friday through Thursday) ISSUED AT 307 PM CDT THU APR 9 2015 Morning upper air shows a potential severe event this afternoon and evening, as main upper level shortwave and vort max over southwest NE at 12z will be rotating to the east. Low level thermal ridge and moisture axis extends into MO/IL ahead of the approaching front. low level jet is particularly strong flowing into MO/western IL and so ample shear available in warm sector. HRRR model and NAM a little slower on the movement of the front through the region, going through this evening. Shear with strong upper jet and low level southern jet will make severe potential with severe storms possible on the cold front as it sweeps through. Deepening surface low to move northeast into eastern IA and then southern WI. High pressure in control until weak front moves in and brings showers on late Sunday and Sunday night. Another chance off showers Tuesday into Thursday. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) ISSUED AT 700 PM CDT THU APR 9 2015 Line of storms firing along a cold front will produce heavy rain, hail and possible tornadoes. Lower chances that any terminal site will get hit directly by any severe weather, but still possible. Target window should be 2 hours as the line moves through, so we continued with 2hr tempos for heavy rain and MVFR vis/cig. Upstream obs and satellite images show a break in the MVFR cigs should follow the line, before MVFR clouds return in wrap-around moisture behind the low pressure system. Will continue MVFR clouds until 10z at PIA, then advance clearing eastward into Friday morning. Strong winds will continue both ahead of the front and behind. Wind direction will remain SW ahead of the front, with gusts to 30kt, then become west later tonight. Gusts will increase to 25-30kt tomorrow as mid level jet winds continue to be strong. && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH until 1 AM CDT Friday FOR ILZ054>057-061>063- 066>068-071>073. && $$ SHORT TERM...Barnes LONG TERM...Goetsch AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
553 PM CDT WED APR 8 2015 .UPDATE... 547 PM CDT I ADDED A DENSE FOG ADVISORY FOR LAKE AND COOK COUNTIES IN ILLINOIS AS DENSE FOG HAS DEVELOPED NEAR THE LAKE SHORES. IT IS POSSIBLE THIS DENSE FOG COULD DEVELOP FARTHER INLAND THROUGH THE EVENING. IT IS EVEN POSSIBLE THAT FOG COULD OVERSPREAD MUCH OF NORTHERN ILLINOIS TONIGHT AS A WARM FRONT AND HIGH DEW POINT AIR BEGINS TO SLOWLY SHIFT NORTHWARD INTO THE COLDER AIRMASS ACROSS NORTHERN ILLINOIS. CONFIDENCE REMAINS LOW ON THE EXTENT OF INLAND DEVELOPMENT OF THIS FOG...HOWEVER...AS SHOWERS AND THUNDERSTORM ACTIVITY COULD DIMINISH THE EXTENT OF FOG COVERAGE OVERNIGHT. SO...WE WILL CONTINUE TO MONITOR THIS THREAT THROUGH THE EVENING. KJB && .SHORT TERM... 322 PM CDT THROUGH THURSDAY NIGHT... QUITE THE CHALLENGING SHORT TERM FORECAST WITH SEVERE WEATHER POSSIBILITIES THROUGHOUT THE TIME AND PROBABLE RAPIDLY SOARING TEMPERATURES FOR THE WHOLE AREA FIRST THING FRIDAY MORNING. THE MAIN TIME FOR POSSIBLE SURFACE-BASED SEVERE WEATHER...INCLUDING WIND AND POSSIBLE TORNADO CONCERNS...CONTINUES TO BE MID-AFTERNOON THROUGH EARLY EVENING ON THURSDAY. THE SURFACE WARM FRONT IS DRAPED ACROSS CENTRAL ILLINOIS AS OF 3 PM...INCLUDING INTO THE FAR SOUTHERN FORECAST AREA. A 1011MB SURFACE LOW REFLECTION IS SEEN IN THE WIND ALONG THIS NEAR DECATUR/CHAMPAIGN...WITH FESTERING NEAR OR SURFACE BASED STORMS JUST AHEAD OF THIS NEAR THE I-74 CORRIDOR OCCASIONALLY PULSING WITH HIGHER CORES. SATELLITE IMAGERY AND RAP ANALYSIS INDICATES THE LIKELY PRESENCE OF VERY SUBTLE MID-LEVEL IMPULSES ACROSS IA/IL/NORTHERN MO...ALL AHEAD OF AN INCREASING UPPER JET NOSING EASTWARD INTO THE OZARK REGION THIS AFTERNOON. IT IS ANTICIPATED THAT THESE PESKY MID-LEVEL FEATURES WILL CONTINUE TO TRAVERSE ACROSS THE AREA THROUGH TONIGHT AND THURSDAY MORNING WITH OVERALL UPPER SUPPORT FOR LIFT GRADUALLY IMPROVING. ONE PROBLEM FOR RAPIDLY INCREASING CONVECTIVE COVERAGE THIS EVENING IS THAT THE STRONGER LOW-LEVEL JET AND MOISTURE TRANSPORT LOOK TO NOT ARRIVE UNTIL LATER INTO THE EVENING AND OVERNIGHT...WHICH SEEMS NECESSARY TO TAP THE ELEVATED MIXED LAYER/VERY STEEP ELEVATED LAPSE RATES FOR MORE WIDESPREAD AND STRONGER CONVECTION. ALSO...STORMS ACROSS THE OZARKS INTO MO AND SW IL MAY LIMIT THE EFFECTIVENESS OF MOISTURE TRANSPORT INTO OUR AREA...AT LEAST AT FIRST THIS EVENING. A FURTHER HINDRANCE TO CONFIDENCE FOR TONIGHT IS THAT CONVECTIVE-ALLOWING MODELS HAVE REALLY STRUGGLED AND DIVERGED WITH HOW TONIGHT WILL PAN OUT FOR STORM COVERAGE. HAVE GONE WITH THE THOUGHT LATER THIS EVENING INTO OVERNIGHT/EARLY THURSDAY MORNING WITH HIGHER LIKELIHOOD FOR STORMS...BUT CERTAINLY CANNOT RULE OUT SCATTERED EVENING ACTIVITY WITHIN THE BROAD WARM ADVECTIVE ZONE. GIVEN THE AFOREMENTIONED LAPSE RATES AND HIGH LEVELS OF CAPE IN THE HAIL GROWTH ZONE...LARGE HAIL WILL CONTINUE TO BE THE MOST PROBABLE THREAT...WITH ANY WIND THREATS REALLY SOUTH OF I-80...IF NOT EVEN SOUTH OF U.S. HIGHWAY 24. AS THE MAIN UPPER TROUGH EJECTS INTO THE CENTRAL PLAINS OVERNIGHT...THE SURFACE RESPONSE SHOULD ALLOW THE WARM FRONT TO CREEP NORTHWARD...AND MAYBE AT A QUICK RATE IF NOT MUCH CONVECTION IS PRESENT. TEMPERATURES WILL THEN WARM AND QUITE QUICKLY WITH THE FRONT PASSAGE...ALLOWING FOR TEMPERATURES TO SOAR INTO THE 70S THURSDAY...EVEN WITH MORNING STORM ACTIVITY. AROUND 80 DEGREES IS POSSIBLE JUST GIVEN OBSERVATION TRENDS TO OUR SOUTH TODAY. THE WARM SECTOR IS LIKELY TO HAVE AT LEAST SOME ELEVATED STORMS THROUGH THE MORNING AND MAYBE EVEN INTO THE AFTERNOON GIVEN THE STEEP LAPSE RATES PRESENT. THIS WILL LIKELY HAVE SOME RESULT ON REGENERATION/RE-INTENSIFICATION OF STORMS...BUT ITS POSSIBLE ANY FESTERING ELEVATED STORMS ARE ABLE TO ROOT LOWER AS THE AFTERNOON PROGRESSES AND BUOYANCY IMPROVES. THE SYNOPTIC PATTERN OF A QUICKLY MOVING CLIMATOLOGICALLY COLD UPPER TROUGH ACROSS A WARM SECTOR CHARACTERIZED BY EARLY APRIL DEW POINTS IN THE 60S CERTAINLY FAVORS ORGANIZED STORM POTENTIAL...INCLUDING SUPERCELLS WITH SIGNIFICANT SEVERE POTENTIAL...AS FURTHER VERIFIED BY SEVERAL OF THE TOP MATCHING CIPS ANALOGS /SIMILAR SCENARIOS/. HOWEVER...SEVERAL ANALOGS SHOW VERY LIMITED SEVERE WEATHER...AS THE PRESENT INGREDIENTS JUST DID NOT LINE UP PERFECTLY AS CAN OFTEN BE THE CASE IN MODERATE/STRONG DYNAMIC SITUATIONS. SO CONFIDENCE REMAINS MINIMAL ON COVERAGE OF HIGHER INTENSITY STORMS...BUT AT THIS JUNCTURE WOULD BE SURPRISED TO NOT HAVE AT LEAST AN UPTICK IN LOWER ROOTED STORMS DURING THE MID-AFTERNOON THROUGH EARLY EVENING PERIOD MOVING FROM WEST TO EAST ACROSS THE AREA. WHILE THE NORTHERN CWA MAY HAVE MORE BACKED LOW-LEVEL FLOW...THE ENTIRE AREA WILL BE UNDER A STRONG SSW 50-55 KT LOW- LEVEL JET WHICH WOULD KEEP SOME THREATS OF SURFACE BASED CONVECTION THROUGH THE EVENING AHEAD OF THE FRONT. HAIL WILL REMAIN THE GREATEST CONCERN...ESPECIALLY WITH THE AFTERNOON ACTIVITY...BUT SOME ORGANIZED STRONG WINDS OR TORNADOES IN THE REGION ARE POSSIBLE DEPENDING ON STORM MODE/COVERAGE. STORMS SHOULD BE EAST OF THE AREA BY 9 PM-12 AM THURSDAY EVENING WITH COOLER AND DRIER AIR WRAPPING IN ON GUSTY WESTERLY WINDS. MTF && .LONG TERM... FRIDAY THROUGH SATURDAY... FORECAST CONFIDENCE HIGH. A POTENT SHORTWAVE WILL ROLL THROUGH SOUTHERN WI ON FRIDAY. THE CYCLONIC FLOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO PLENTY OF DIURNAL CUMULUS CLOUDS. A FEW SHOWERS ARE POSSIBLE TOWARD NORTHEAST IL CLOSER TO THE VORTICITY MAXIMUM. SURFACE HIGH PRESSURE WILL SPREAD INTO THE MIDWEST FRIDAY NIGHT THROUGH SATURDAY AND BRING QUIET WEATHER. CLEAR SKIES FRIDAY NIGHT WILL ALLOW TEMPS TO DROP INTO THE LOWER TO MID 30S... COLDEST NEAR THE WI BORDER. TEMPERATURES SHOULD REBOUND INTO THE LOWER 60S SATURDAY WITH WEAK WARM AIR ADVECTION OVER THE AREA. SUNDAY... FORECAST CONFIDENCE HIGH. SOUTHERLY WINDS WILL INCREASE AHEAD OF A MID LEVEL SHORTWAVE AND AN ASSOCIATED SURFACE LOW PRESSURE TROUGH SWINGING THROUGH THE UPPER MIDWEST AND GREAT LAKES REGION. LOW LEVELS ARE EXPECTED TO BE DRY... SO NO PRECIP IS ANTICIPATED ACROSS NORTHEAST IL DURING THE DAY. LIGHT SHOWERS WILL BE POSSIBLE SUNDAY NIGHT AS THE SURFACE TROUGH PASSES THROUGH THE AREA. MODELS SOUNDINGS SHOW MINIMAL INSTABILITY SO I LEFT OUT THUNDER. MONDAY THROUGH TUESDAY... FORECAST CONFIDENCE MEDIUM. MODELS ARE SLOWING DOWN THE SPEED OF THE WARM FRONTAL PRECIP INTO CENTRAL IL ON MONDAY. THUS... CHANCES FOR SHOWERS AND THUNDERSTORMS ARE DECREASING. BY MONDAY NIGHT... THE WARM FRONT WILL MAKE IT INTO EITHER NORTHERN IL OR SOUTHERN WI. THIS WILL ALLOW FOR A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH TUESDAY NIGHT. THERE IS A POSSIBILITY FOR SEVERE WITH THIS SYSTEM AND IT WILL NEED TO BE WATCHED. MRC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * VFR VSBY THIS AFTERNOON TO LOWER BACK TO IFR TO MVFR AFTER SUNSET THIS EVENING WITH FOG * MVFR TO VFR CIGS LIKELY TO GO BACK TO IFR AFTER SUNSET * SCATTERED THUNDERSTORMS DEVELOPING LATE THIS EVENING AND ESPECIALLY OVERNIGHT AND DIMINISHING DURING MID AND LATE THU MORNING. * LIFR VIS/CIGS POSSIBLE TONIGHT...IMPROVING DURING MID/LATE THURSDAY MORNING AS WARM FRONT LIFTS NORTH ACROSS AREA. KMH/EJL //DISCUSSION...UPDATED 18Z... CIGS/VIS SHOULD CONTINUE TO SLOWLY IMPROVE THIS AFTERNOON WITH MVFR CIGS AND VSBYS DEVELOPING. CIGS/VIS COULD POSSIBLY LOWER BACK TO IFR OR EVEN LIFR AFTER SUNSET THIS EVENING INTO OVERNIGHT BUT CONFIDENCE IS LOW. COMPLEX OF SHOWERS AND THUNDERSTORMS ACROSS SW HALF OF IL WILL TRACK ENE AND INITIALLY STAY SOUTH OF CHICAGO AREA THIS AFTERNOON INTO MID EVENING. FOCUS SHIFTS TO COMPLEX OF MORE THUNDERSTORMS TO DEVELOP OVER MO AND TRACK NE INTO NE IL LATE THIS EVENING OR OVERNIGHT AND THEN DIMINISH DURING MID/LATE THU MORNING AS WARM FRONT LIFTS NORTH OF AREA. CONFIDENCE REGARDING TIMING/LOCATION/COVERAGE IS LOW TO MEDIUM AND OPTED TO CONTINUE WITH A LONGER DURATION OF VICINITY THUNDER FROM 05-09Z WITH HIGHER COVERAGE OF SHOWERS AND THUNDERSTORMS FROM 09-15Z. GENERALLY NORTHEAST WINDS 5-10 KTS WILL CONTINUE THRU THIS EVENING WINDS WILL BEGIN TO TURN SOUTHEAST DURING OVERNIGHT...THEN MORE SOUTH SOUTHWEST AND INCREASE TO 10-15 KTS AND GUSTS NEAR 20 KTS LATER THURSDAY MORNING AND THU AFTERNOON AS A WARM FRONT LIFTS THROUGH THE TERMINALS THU MORNING. WHEN THIS OCCURS...EXPECT RAPID IMPROVEMENT THROUGH MVFR CIGS AND LIKELY TO PREVAILING VFR CIGS...OUTSIDE PRECIP...LATER THU MORNING. //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM CONFIDENCE IN CIGS/VSBY LOWERING THIS EVENING AFTER SUNSET WITH FOG * MEDIUM TO HIGH IN WINDS THROUGH THE PERIOD. * MEDIUM CONFIDENCE IN TS FROM LATE EVENING INTO THU MORNING...LOW TO MEDIUM FOR TIMING AND COVERAGE. KMH/EJL //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... * THURSDAY NIGHT...STRONG TSRA IN THE EVENING. MVFR POSSIBLE. STRONG/GUSTY SOUTHWEST WINDS BECOMING WEST. * FRIDAY...DRY/VFR. STRONG/GUSTY WEST WINDS. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY...CHANCE OF SHRA. SOUTHWEST WINDS. && .MARINE... 333 PM... AN INCREASING SURFACE PRESSURE GRADIENT IS LEADING TO NNE WINDS OF 15 TO 20 MPH WITH A FEW HIGHER GUSTS THIS AFTERNOON OVER SOUTHERN LAKE MICHIGAN. THERE IS ALSO A FAVORABLE FETCH FOR HIGH WAVES IN THE NEARSHORE ZONES. EXPECT THIS TO PERSIST THROUGH LATE TONIGHT. WESTERLY WINDS IN THE WAKE OF A STRONG LOW PRESSURE SYSTEM WILL BRING GUSTY WINDS TO ALL OF LAKE MICHIGAN THURSDAY NIGHT THROUGH FRIDAY. GALE FORCE GUSTS TO 35 KNOTS OVER THE OPEN WATERS OF SOUTHERN LAKE MICHIGAN ARE POSSIBLE. BREEZY SOUTH WINDS ARE EXPECTED ON SUNDAY AS HIGH PRESSURE SHIFTS EAST OF LAKE MICHIGAN. WIND GUSTS SHOULD REMAIN BELOW GALE FORCE... BUT SMALL CRAFT CONDITIONS MAY BE MET OVER THE NEARSHORE WATERS OF NORTHEAST IL. MRC && .LOT WATCHES/WARNINGS/ADVISORIES... IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM THURSDAY. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 PM WEDNESDAY. DENSE FOG ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
PORTION ISSUED BY NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 333 PM CDT WED APR 8 2015 .SHORT TERM... 322 PM CDT THROUGH THURSDAY NIGHT... QUITE THE CHALLENGING SHORT TERM FORECAST WITH SEVERE WEATHER POSSIBILITIES THROUGHOUT THE TIME AND PROBABLE RAPIDLY SOARING TEMPERATURES FOR THE WHOLE AREA FIRST THING FRIDAY MORNING. THE MAIN TIME FOR POSSIBLE SURFACE-BASED SEVERE WEATHER...INCLUDING WIND AND POSSIBLE TORNADO CONCERNS...CONTINUES TO BE MID-AFTERNOON THROUGH EARLY EVENING ON THURSDAY. THE SURFACE WARM FRONT IS DRAPED ACROSS CENTRAL ILLINOIS AS OF 3 PM...INCLUDING INTO THE FAR SOUTHERN FORECAST AREA. A 1011MB SURFACE LOW REFLECTION IS SEEN IN THE WIND ALONG THIS NEAR DECATUR/CHAMPAIGN...WITH FESTERING NEAR OR SURFACE BASED STORMS JUST AHEAD OF THIS NEAR THE I-74 CORRIDOR OCCASIONALLY PULSING WITH HIGHER CORES. SATELLITE IMAGERY AND RAP ANALYSIS INDICATES THE LIKELY PRESENCE OF VERY SUBTLE MID-LEVEL IMPULSES ACROSS IA/IL/NORTHERN MO...ALL AHEAD OF AN INCREASING UPPER JET NOSING EASTWARD INTO THE OZARK REGION THIS AFTERNOON. IT IS ANTICIPATED THAT THESE PESKY MID-LEVEL FEATURES WILL CONTINUE TO TRAVERSE ACROSS THE AREA THROUGH TONIGHT AND THURSDAY MORNING WITH OVERALL UPPER SUPPORT FOR LIFT GRADUALLY IMPROVING. ONE PROBLEM FOR RAPIDLY INCREASING CONVECTIVE COVERAGE THIS EVENING IS THAT THE STRONGER LOW-LEVEL JET AND MOISTURE TRANSPORT LOOK TO NOT ARRIVE UNTIL LATER INTO THE EVENING AND OVERNIGHT...WHICH SEEMS NECESSARY TO TAP THE ELEVATED MIXED LAYER/VERY STEEP ELEVATED LAPSE RATES FOR MORE WIDESPREAD AND STRONGER CONVECTION. ALSO...STORMS ACROSS THE OZARKS INTO MO AND SW IL MAY LIMIT THE EFFECTIVENESS OF MOISTURE TRANSPORT INTO OUR AREA...AT LEAST AT FIRST THIS EVENING. A FURTHER HINDRANCE TO CONFIDENCE FOR TONIGHT IS THAT CONVECTIVE-ALLOWING MODELS HAVE REALLY STRUGGLED AND DIVERGED WITH HOW TONIGHT WILL PAN OUT FOR STORM COVERAGE. HAVE GONE WITH THE THOUGHT LATER THIS EVENING INTO OVERNIGHT/EARLY THURSDAY MORNING WITH HIGHER LIKELIHOOD FOR STORMS...BUT CERTAINLY CANNOT RULE OUT SCATTERED EVENING ACTIVITY WITHIN THE BROAD WARM ADVECTIVE ZONE. GIVEN THE AFOREMENTIONED LAPSE RATES AND HIGH LEVELS OF CAPE IN THE HAIL GROWTH ZONE...LARGE HAIL WILL CONTINUE TO BE THE MOST PROBABLE THREAT...WITH ANY WIND THREATS REALLY SOUTH OF I-80...IF NOT EVEN SOUTH OF U.S. HIGHWAY 24. AS THE MAIN UPPER TROUGH EJECTS INTO THE CENTRAL PLAINS OVERNIGHT...THE SURFACE RESPONSE SHOULD ALLOW THE WARM FRONT TO CREEP NORTHWARD...AND MAYBE AT A QUICK RATE IF NOT MUCH CONVECTION IS PRESENT. TEMPERATURES WILL THEN WARM AND QUITE QUICKLY WITH THE FRONT PASSAGE...ALLOWING FOR TEMPERATURES TO SOAR INTO THE 70S THURSDAY...EVEN WITH MORNING STORM ACTIVITY. AROUND 80 DEGREES IS POSSIBLE JUST GIVEN OBSERVATION TRENDS TO OUR SOUTH TODAY. THE WARM SECTOR IS LIKELY TO HAVE AT LEAST SOME ELEVATED STORMS THROUGH THE MORNING AND MAYBE EVEN INTO THE AFTERNOON GIVEN THE STEEP LAPSE RATES PRESENT. THIS WILL LIKELY HAVE SOME RESULT ON REGENERATION/RE-INTENSIFICATION OF STORMS...BUT ITS POSSIBLE ANY FESTERING ELEVATED STORMS ARE ABLE TO ROOT LOWER AS THE AFTERNOON PROGRESSES AND BUOYANCY IMPROVES. THE SYNOPTIC PATTERN OF A QUICKLY MOVING CLIMATOLOGICALLY COLD UPPER TROUGH ACROSS A WARM SECTOR CHARACTERIZED BY EARLY APRIL DEW POINTS IN THE 60S CERTAINLY FAVORS ORGANIZED STORM POTENTIAL...INCLUDING SUPERCELLS WITH SIGNIFICANT SEVERE POTENTIAL...AS FURTHER VERIFIED BY SEVERAL OF THE TOP MATCHING CIPS ANALOGS /SIMILAR SCENARIOS/. HOWEVER...SEVERAL ANALOGS SHOW VERY LIMITED SEVERE WEATHER...AS THE PRESENT INGREDIENTS JUST DID NOT LINE UP PERFECTLY AS CAN OFTEN BE THE CASE IN MODERATE/STRONG DYNAMIC SITUATIONS. SO CONFIDENCE REMAINS MINIMAL ON COVERAGE OF HIGHER INTENSITY STORMS...BUT AT THIS JUNCTURE WOULD BE SURPRISED TO NOT HAVE AT LEAST AN UPTICK IN LOWER ROOTED STORMS DURING THE MID-AFTERNOON THROUGH EARLY EVENING PERIOD MOVING FROM WEST TO EAST ACROSS THE AREA. WHILE THE NORTHERN CWA MAY HAVE MORE BACKED LOW-LEVEL FLOW...THE ENTIRE AREA WILL BE UNDER A STRONG SSW 50-55 KT LOW- LEVEL JET WHICH WOULD KEEP SOME THREATS OF SURFACE BASED CONVECTION THROUGH THE EVENING AHEAD OF THE FRONT. HAIL WILL REMAIN THE GREATEST CONCERN...ESPECIALLY WITH THE AFTERNOON ACTIVITY...BUT SOME ORGANIZED STRONG WINDS OR TORNADOES IN THE REGION ARE POSSIBLE DEPENDING ON STORM MODE/COVERAGE. STORMS SHOULD BE EAST OF THE AREA BY 9 PM-12 AM THURSDAY EVENING WITH COOLER AND DRIER AIR WRAPPING IN ON GUSTY WESTERLY WINDS. MTF && .LONG TERM... FRIDAY THROUGH SATURDAY... FORECAST CONFIDENCE HIGH. A POTENT SHORTWAVE WILL ROLL THROUGH SOUTHERN WI ON FRIDAY. THE CYCLONIC FLOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO PLENTY OF DIURNAL CUMULUS CLOUDS. A FEW SHOWERS ARE POSSIBLE TOWARD NORTHEAST IL CLOSER TO THE VORTICITY MAXIMUM. SURFACE HIGH PRESSURE WILL SPREAD INTO THE MIDWEST FRIDAY NIGHT THROUGH SATURDAY AND BRING QUIET WEATHER. CLEAR SKIES FRIDAY NIGHT WILL ALLOW TEMPS TO DROP INTO THE LOWER TO MID 30S... COLDEST NEAR THE WI BORDER. TEMPERATURES SHOULD REBOUND INTO THE LOWER 60S SATURDAY WITH WEAK WARM AIR ADVECTION OVER THE AREA. SUNDAY... FORECAST CONFIDENCE HIGH. SOUTHERLY WINDS WILL INCREASE AHEAD OF A MID LEVEL SHORTWAVE AND AN ASSOCIATED SURFACE LOW PRESSURE TROUGH SWINGING THROUGH THE UPPER MIDWEST AND GREAT LAKES REGION. LOW LEVELS ARE EXPECTED TO BE DRY... SO NO PRECIP IS ANTICIPATED ACROSS NORTHEAST IL DURING THE DAY. LIGHT SHOWERS WILL BE POSSIBLE SUNDAY NIGHT AS THE SURFACE TROUGH PASSES THROUGH THE AREA. MODELS SOUNDINGS SHOW MINIMAL INSTABILITY SO I LEFT OUT THUNDER. MONDAY THROUGH TUESDAY... FORECAST CONFIDENCE MEDIUM. MODELS ARE SLOWING DOWN THE SPEED OF THE WARM FRONTAL PRECIP INTO CENTRAL IL ON MONDAY. THUS... CHANCES FOR SHOWERS AND THUNDERSTORMS ARE DECREASING. BY MONDAY NIGHT... THE WARM FRONT WILL MAKE IT INTO EITHER NORTHERN IL OR SOUTHERN WI. THIS WILL ALLOW FOR A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH TUESDAY NIGHT. THERE IS A POSSIBILITY FOR SEVERE WITH THIS SYSTEM AND IT WILL NEED TO BE WATCHED. MRC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * VFR VSBY THIS AFTERNOON TO LOWER BACK TO IFR TO MVFR AFTER SUNSET THIS EVENING WITH FOG * MVFR TO VFR CIGS LIKELY TO GO BACK TO IFR AFTER SUNSET * SCATTERED THUNDERSTORMS DEVELOPING LATE THIS EVENING AND ESPECIALLY OVERNIGHT AND DIMINISHING DURING MID AND LATE THU MORNING. * LIFR VIS/CIGS POSSIBLE TONIGHT...IMPROVING DURING MID/LATE THURSDAY MORNING AS WARM FRONT LIFTS NORTH ACROSS AREA. KMH/EJL //DISCUSSION...UPDATED 18Z... CIGS/VIS SHOULD CONTINUE TO SLOWLY IMPROVE THIS AFTERNOON WITH MVFR CIGS AND VSBYS DEVELOPING. CIGS/VIS COULD POSSIBLY LOWER BACK TO IFR OR EVEN LIFR AFTER SUNSET THIS EVENING INTO OVERNIGHT BUT CONFIDENCE IS LOW. COMPLEX OF SHOWERS AND THUNDERSTORMS ACROSS SW HALF OF IL WILL TRACK ENE AND INITIALLY STAY SOUTH OF CHICAGO AREA THIS AFTERNOON INTO MID EVENING. FOCUS SHIFTS TO COMPLEX OF MORE THUNDERSTORMS TO DEVELOP OVER MO AND TRACK NE INTO NE IL LATE THIS EVENING OR OVERNIGHT AND THEN DIMINISH DURING MID/LATE THU MORNING AS WARM FRONT LIFTS NORTH OF AREA. CONFIDENCE REGARDING TIMING/LOCATION/COVERAGE IS LOW TO MEDIUM AND OPTED TO CONTINUE WITH A LONGER DURATION OF VICINITY THUNDER FROM 05-09Z WITH HIGHER COVERAGE OF SHOWERS AND THUNDERSTORMS FROM 09-15Z. GENERALLY NORTHEAST WINDS 5-10 KTS WILL CONTINUE THRU THIS EVENING WINDS WILL BEGIN TO TURN SOUTHEAST DURING OVERNIGHT...THEN MORE SOUTH SOUTHWEST AND INCREASE TO 10-15 KTS AND GUSTS NEAR 20 KTS LATER THURSDAY MORNING AND THU AFTERNOON AS A WARM FRONT LIFTS THROUGH THE TERMINALS THU MORNING. WHEN THIS OCCURS...EXPECT RAPID IMPROVEMENT THROUGH MVFR CIGS AND LIKELY TO PREVAILING VFR CIGS...OUTSIDE PRECIP...LATER THU MORNING. //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM CONFIDENCE IN CIGS/VSBY LOWERING THIS EVENING AFTER SUNSET WITH FOG * MEDIUM TO HIGH IN WINDS THROUGH THE PERIOD. * MEDIUM CONFIDENCE IN TS FROM LATE EVENING INTO THU MORNING...LOW TO MEDIUM FOR TIMING AND COVERAGE. KMH/EJL //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... * THURSDAY NIGHT...STRONG TSRA IN THE EVENING. MVFR POSSIBLE. STRONG/GUSTY SOUTHWEST WINDS BECOMING WEST. * FRIDAY...DRY/VFR. STRONG/GUSTY WEST WINDS. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY...CHANCE OF SHRA. SOUTHWEST WINDS. && .MARINE... 333 PM... AN INCREASING SURFACE PRESSURE GRADIENT IS LEADING TO NNE WINDS OF 15 TO 20 MPH WITH A FEW HIGHER GUSTS THIS AFTERNOON OVER SOUTHERN LAKE MICHIGAN. THERE IS ALSO A FAVORABLE FETCH FOR HIGH WAVES IN THE NEARSHORE ZONES. EXPECT THIS TO PERSIST THROUGH LATE TONIGHT. WESTERLY WINDS IN THE WAKE OF A STRONG LOW PRESSURE SYSTEM WILL BRING GUSTY WINDS TO ALL OF LAKE MICHIGAN THURSDAY NIGHT THROUGH FRIDAY. GALE FORCE GUSTS TO 35 KNOTS OVER THE OPEN WATERS OF SOUTHERN LAKE MICHIGAN ARE POSSIBLE. BREEZY SOUTH WINDS ARE EXPECTED ON SUNDAY AS HIGH PRESSURE SHIFTS EAST OF LAKE MICHIGAN. WIND GUSTS SHOULD REMAIN BELOW GALE FORCE... BUT SMALL CRAFT CONDITIONS MAY BE MET OVER THE NEARSHORE WATERS OF NORTHEAST IL. MRC && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 5 AM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
329 PM CDT WED APR 8 2015 .SHORT TERM... 322 PM CDT THROUGH THURSDAY NIGHT... QUITE THE CHALLENGING SHORT TERM FORECAST WITH SEVERE WEATHER POSSIBILITIES THROUGHOUT THE TIME AND PROBABLE RAPIDLY SOARING TEMPERATURES FOR THE WHOLE AREA FIRST THING FRIDAY MORNING. THE MAIN TIME FOR POSSIBLE SURFACE-BASED SEVERE WEATHER...INCLUDING WIND AND POSSIBLE TORNADO CONCERNS...CONTINUES TO BE MID-AFTERNOON THROUGH EARLY EVENING ON THURSDAY. THE SURFACE WARM FRONT IS DRAPED ACROSS CENTRAL ILLINOIS AS OF 3 PM...INCLUDING INTO THE FAR SOUTHERN FORECAST AREA. A 1011MB SURFACE LOW REFLECTION IS SEEN IN THE WIND ALONG THIS NEAR DECATUR/CHAMPAIGN...WITH FESTERING NEAR OR SURFACE BASED STORMS JUST AHEAD OF THIS NEAR THE I-74 CORRIDOR OCCASIONALLY PULSING WITH HIGHER CORES. SATELLITE IMAGERY AND RAP ANALYSIS INDICATES THE LIKELY PRESENCE OF VERY SUBTLE MID-LEVEL IMPULSES ACROSS IA/IL/NORTHERN MO...ALL AHEAD OF AN INCREASING UPPER JET NOSING EASTWARD INTO THE OZARK REGION THIS AFTERNOON. IT IS ANTICIPATED THAT THESE PESKY MID-LEVEL FEATURES WILL CONTINUE TO TRAVERSE ACROSS THE AREA THROUGH TONIGHT AND THURSDAY MORNING WITH OVERALL UPPER SUPPORT FOR LIFT GRADUALLY IMPROVING. ONE PROBLEM FOR RAPIDLY INCREASING CONVECTIVE COVERAGE THIS EVENING IS THAT THE STRONGER LOW-LEVEL JET AND MOISTURE TRANSPORT LOOK TO NOT ARRIVE UNTIL LATER INTO THE EVENING AND OVERNIGHT...WHICH SEEMS NECESSARY TO TAP THE ELEVATED MIXED LAYER/VERY STEEP ELEVATED LAPSE RATES FOR MORE WIDESPREAD AND STRONGER CONVECTION. ALSO...STORMS ACROSS THE OZARKS INTO MO AND SW IL MAY LIMIT THE EFFECTIVENESS OF MOISTURE TRANSPORT INTO OUR AREA...AT LEAST AT FIRST THIS EVENING. A FURTHER HINDRANCE TO CONFIDENCE FOR TONIGHT IS THAT CONVECTIVE-ALLOWING MODELS HAVE REALLY STRUGGLED AND DIVERGED WITH HOW TONIGHT WILL PAN OUT FOR STORM COVERAGE. HAVE GONE WITH THE THOUGHT LATER THIS EVENING INTO OVERNIGHT/EARLY THURSDAY MORNING WITH HIGHER LIKELIHOOD FOR STORMS...BUT CERTAINLY CANNOT RULE OUT SCATTERED EVENING ACTIVITY WITHIN THE BROAD WARM ADVECTIVE ZONE. GIVEN THE AFOREMENTIONED LAPSE RATES AND HIGH LEVELS OF CAPE IN THE HAIL GROWTH ZONE...LARGE HAIL WILL CONTINUE TO BE THE MOST PROBABLE THREAT...WITH ANY WIND THREATS REALLY SOUTH OF I-80...IF NOT EVEN SOUTH OF U.S. HIGHWAY 24. AS THE MAIN UPPER TROUGH EJECTS INTO THE CENTRAL PLAINS OVERNIGHT...THE SURFACE RESPONSE SHOULD ALLOW THE WARM FRONT TO CREEP NORTHWARD...AND MAYBE AT A QUICK RATE IF NOT MUCH CONVECTION IS PRESENT. TEMPERATURES WILL THEN WARM AND QUITE QUICKLY WITH THE FRONT PASSAGE...ALLOWING FOR TEMPERATURES TO SOAR INTO THE 70S THURSDAY...EVEN WITH MORNING STORM ACTIVITY. AROUND 80 DEGREES IS POSSIBLE JUST GIVEN OBSERVATION TRENDS TO OUR SOUTH TODAY. THE WARM SECTOR IS LIKELY TO HAVE AT LEAST SOME ELEVATED STORMS THROUGH THE MORNING AND MAYBE EVEN INTO THE AFTERNOON GIVEN THE STEEP LAPSE RATES PRESENT. THIS WILL LIKELY HAVE SOME RESULT ON REGENERATION/RE-INTENSIFICATION OF STORMS...BUT ITS POSSIBLE ANY FESTERING ELEVATED STORMS ARE ABLE TO ROOT LOWER AS THE AFTERNOON PROGRESSES AND BUOYANCY IMPROVES. THE SYNOPTIC PATTERN OF A QUICKLY MOVING CLIMATOLOGICALLY COLD UPPER TROUGH ACROSS A WARM SECTOR CHARACTERIZED BY EARLY APRIL DEW POINTS IN THE 60S CERTAINLY FAVORS ORGANIZED STORM POTENTIAL...INCLUDING SUPERCELLS WITH SIGNIFICANT SEVERE POTENTIAL...AS FURTHER VERIFIED BY SEVERAL OF THE TOP MATCHING CIPS ANALOGS /SIMILAR SCENARIOS/. HOWEVER...SEVERAL ANALOGS SHOW VERY LIMITED SEVERE WEATHER...AS THE PRESENT INGREDIENTS JUST DID NOT LINE UP PERFECTLY AS CAN OFTEN BE THE CASE IN MODERATE/STRONG DYNAMIC SITUATIONS. SO CONFIDENCE REMAINS MINIMAL ON COVERAGE OF HIGHER INTENSITY STORMS...BUT AT THIS JUNCTURE WOULD BE SURPRISED TO NOT HAVE AT LEAST AN UPTICK IN LOWER ROOTED STORMS DURING THE MID-AFTERNOON THROUGH EARLY EVENING PERIOD MOVING FROM WEST TO EAST ACROSS THE AREA. WHILE THE NORTHERN CWA MAY HAVE MORE BACKED LOW-LEVEL FLOW...THE ENTIRE AREA WILL BE UNDER A STRONG SSW 50-55 KT LOW- LEVEL JET WHICH WOULD KEEP SOME THREATS OF SURFACE BASED CONVECTION THROUGH THE EVENING AHEAD OF THE FRONT. HAIL WILL REMAIN THE GREATEST CONCERN...ESPECIALLY WITH THE AFTERNOON ACTIVITY...BUT SOME ORGANIZED STRONG WINDS OR TORNADOES IN THE REGION ARE POSSIBLE DEPENDING ON STORM MODE/COVERAGE. STORMS SHOULD BE EAST OF THE AREA BY 9 PM-12 AM THURSDAY EVENING WITH COOLER AND DRIER AIR WRAPPING IN ON GUSTY WESTERLY WINDS. MTF && .LONG TERM... TO BE ISSUED SHORTLY. && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * VFR VSBY THIS AFTERNOON TO LOWER BACK TO IFR TO MVFR AFTER SUNSET THIS EVENING WITH FOG * MVFR TO VFR CIGS LIKELY TO GO BACK TO IFR AFTER SUNSET * SCATTERED THUNDERSTORMS DEVELOPING LATE THIS EVENING AND ESPECIALLY OVERNIGHT AND DIMINISHING DURING MID AND LATE THU MORNING. * LIFR VIS/CIGS POSSIBLE TONIGHT...IMPROVING DURING MID/LATE THURSDAY MORNING AS WARM FRONT LIFTS NORTH ACROSS AREA. KMH/EJL //DISCUSSION...UPDATED 18Z... CIGS/VIS SHOULD CONTINUE TO SLOWLY IMPROVE THIS AFTERNOON WITH MVFR CIGS AND VSBYS DEVELOPING. CIGS/VIS COULD POSSIBLY LOWER BACK TO IFR OR EVEN LIFR AFTER SUNSET THIS EVENING INTO OVERNIGHT BUT CONFIDENCE IS LOW. COMPLEX OF SHOWERS AND THUNDERSTORMS ACROSS SW HALF OF IL WILL TRACK ENE AND INITIALLY STAY SOUTH OF CHICAGO AREA THIS AFTERNOON INTO MID EVENING. FOCUS SHIFTS TO COMPLEX OF MORE THUNDERSTORMS TO DEVELOP OVER MO AND TRACK NE INTO NE IL LATE THIS EVENING OR OVERNIGHT AND THEN DIMINISH DURING MID/LATE THU MORNING AS WARM FRONT LIFTS NORTH OF AREA. CONFIDENCE REGARDING TIMING/LOCATION/COVERAGE IS LOW TO MEDIUM AND OPTED TO CONTINUE WITH A LONGER DURATION OF VICINITY THUNDER FROM 05-09Z WITH HIGHER COVERAGE OF SHOWERS AND THUNDERSTORMS FROM 09-15Z. GENERALLY NORTHEAST WINDS 5-10 KTS WILL CONTINUE THRU THIS EVENING WINDS WILL BEGIN TO TURN SOUTHEAST DURING OVERNIGHT...THEN MORE SOUTH SOUTHWEST AND INCREASE TO 10-15 KTS AND GUSTS NEAR 20 KTS LATER THURSDAY MORNING AND THU AFTERNOON AS A WARM FRONT LIFTS THROUGH THE TERMINALS THU MORNING. WHEN THIS OCCURS...EXPECT RAPID IMPROVEMENT THROUGH MVFR CIGS AND LIKELY TO PREVAILING VFR CIGS...OUTSIDE PRECIP...LATER THU MORNING. //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM CONFIDENCE IN CIGS/VSBY LOWERING THIS EVENING AFTER SUNSET WITH FOG * MEDIUM TO HIGH IN WINDS THROUGH THE PERIOD. * MEDIUM CONFIDENCE IN TS FROM LATE EVENING INTO THU MORNING...LOW TO MEDIUM FOR TIMING AND COVERAGE. KMH/EJL //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... * THURSDAY NIGHT...STRONG TSRA IN THE EVENING. MVFR POSSIBLE. STRONG/GUSTY SOUTHWEST WINDS BECOMING WEST. * FRIDAY...DRY/VFR. STRONG/GUSTY WEST WINDS. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY...CHANCE OF SHRA. SOUTHWEST WINDS. && .MARINE... 415 AM...A FRONTAL BOUNDARY WILL REMAIN STATIONARY JUST SOUTH OF LAKE MICHIGAN INTO THIS EVENING...THEN BEGIN TO LIFT NORTH ACROSS THE LAKE LATE TONIGHT AND THURSDAY AS A WARM FRONT AS LOW PRESSURE OVER THE PLAINS MOVES NORTHEAST TONIGHT AND THURSDAY...REACHING NORTHERN LAKE MICHIGAN BY FRIDAY MORNING. NORTHEAST WINDS WILL REMAIN IN THE 20-25KT RANGE TODAY...WITH SOME HIGHER GUSTS POSSIBLE. WINDS WILL SLOWLY DIMINISH LATE TONIGHT INTO THURSDAY MORNING...THEN AS WINDS SHIFTING SOUTHWESTERLY THURSDAY AFTERNOON AND ESPECIALLY THURSDAY EVENING...THEY WILL INCREASE TO 30 KT... SHIFTING WESTERLY THURSDAY NIGHT AFTER A COLD FRONT MOVES ACROSS THE LAKE. WINDS WILL SLOWLY DIMINISH FRIDAY AFTERNOON INTO FRIDAY EVENING...THEN BECOME LIGHT SATURDAY AS HIGH PRESSURE MOVES ACROSS THE REGION. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 5 AM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1249 PM CDT WED APR 8 2015 .MESOSCALE DISCUSSION... 1249 PM CDT SURFACE BASED THUNDERSTORMS HAVE BEEN DEVELOPING AND GRADUALLY INTENSIFYING OVER CENTRAL ILLINOIS ALONG THE LEADING EDGE OF THE DECAYING MCS. MODIFYING ILX MORNING SOUNDING FOR CURRENT OBS AND SPC OBJECTIVE MESOANALYSIS DATA SUGGEST MLCAPES NEARING 1000 J/KG IN ADVANCE OF THESE STORMS WITH ONLY MODEST CONVECTIVE INHIBITION. KILX WSR 88-D VWP WOULD SUGGEST 30-35KT OF 0-6KM BULK SHEAR WHICH GIVEN THE INSTABILITY IS CERTAINLY SUFFICIENT FOR THESE STORMS TO INTENSIFY AND POTENTIALLY GROW SEVERE THIS AFTERNOON. NOT TERRIBLY CLEAR THE FORCING MECHANISM AND SFC WINDS ARE VEERS LESSENING LOW LEVEL CONVERGENCE...BUT GIVEN RECENT RADAR TRENDS AND CAPE/SHEAR WITH ONLY WEAK INHIBITION IT SEEMS REASONABLE STORMS WILL CONTINUE AND POTENTIALLY INTENSIFY AS THEY PUSH EAST INTO OUR SOUTHERN MOST CWA. DEEP LAYER SHEAR IS NOT OVERLY IMPRESSIVE...HOWEVER PROXIMITY OF WARM FRONT DOES BEAR WATCHING AS SHOULD A CELL MANAGE TO ATTACH ITSELF TO AND RIDE THE WARM FRONT EAST THE SUPERCELL AND ATTENDANT SEVERE WEATHER POTENTIAL WOULD INCREASE. IZZI && .SHORT TERM... 347 AM CDT THROUGH THURSDAY... TODAY THROUGH FRIDAY NIGHT... MAIN FOCUS IS ON PERIODS OF CONVECTION...PARTICULARLY THIS MORNING ACROSS PART OF THE FORECAST AREAS...AND ACROSS THE ENTIRE AREA TONIGHT INTO THURSDAY. SEVERE WEATHER THREAT REMAINS OF GREAT CONCERN THURSDAY AFTERNOON AND EVENING. EARLY MORNING SURFACE ANALYSIS DEPICTS LOW PRESSURE OVER NORTHEASTERN MISSOURI...WITH AN INVERTED TROUGH EXTENDING NORTHEAST ACROSS SOUTHEAST WI/LAKE MICHIGAN. THESE FEATURES APPEAR TO BE ASSOCIATED WITH A COUPLE OF MID-LEVEL SHORT WAVE TROUGHS PROPAGATING ACROSS THE REGION IN BROAD WEST-SOUTHWESTERLY FLOW ALOFT. A CLUSTER OF THUNDERSTORMS HAD DEVELOPED ACROSS SOUTHEAST IOWA LAST EVENING IN LOW LEVEL WARM/MOIST ADVECTION MAXIMA NORTHEAST OF THE SURFACE LOW...AND CONTINUE TO PERSIST AND EXPAND SLOWLY EASTWARD ACROSS PARTS OF ILLINOIS EARLY THIS MORNING ON 30 KT 925 MB JET AHEAD OF SHORT WAVE. THESE STORMS ARE LIKELY TO CONTINUE TO DEVELOP EASTWARD ACROSS MAINLY THE SOUTHERN TWO THIRDS OR SO OF THE CWA EARLY THIS MORNING AS THE SURFACE WAVE MOVE THROUGH THE AREA. SPC MESOANALYSIS DATA INDICATES UPSTREAM AIR MASS CHARACTERIZED BY STEEP MID-LEVEL LAPSE RATES IN EXCESS OF 7.5 C/KM YIELDING 1000-1500 J/KG OF ELEVATED MUCAPE...AND ROUGHLY 40-45 KT OF EFFECTIVE DEEP LAYER BULK SHEAR. SOME OF THE STRONGER CORES MAY BE CAPABLE OF PRODUCING SOME MARGINAL HAIL THIS MORNING...THOUGH AN OVERALL WEAKENING TREND IS EXPECTED AS THE LOW LEVEL FLOW VEERS MORE WESTERLY AND DECREASES AND REDUCES LOW LEVEL MOISTURE TRANSPORT/THETA-E ADVECTION ACROSS OUR SOUTH AND SOUTHEAST COUNTIES. THIS TREND IS SUPPORTED BY HIGH-RES HRRR/RAP GUIDANCE WHICH INDICATE ACTIVITY MOVING ACROSS THE AREA THROUGH 13-14Z. MOIST/SATURATED LOW LEVEL AIR MASS HAS ALSO REDUCED VISIBILITY IN FOG OVER THE PAST SEVERAL HOURS...WITH SOME PATCHES OF DENSE FOG NOTED. MAY HAVE TO CONSIDER A HEADLINE...THOUGH MORNING SHOWERS MAY HELP RAISE VISIBILITY SOMEWHAT AND WILL CONTINUE TO MONITOR. NOT MUCH IS EXPECTED IN THE WAY OF ORGANIZED PRECIP FROM MID- MORNING INTO THIS AFTERNOON...WITH PASSAGE OF THE SHORT WAVE AND WEAKENING OF THE SURFACE WAVE ALONG THE FRONT TO OUR SOUTH. WEAK BUT PERSISTENT SOUTHWEST FLOW WILL CONTINUE ABOVE THE SHALLOW COOL BOUNDARY LAYER NORTH OF THE SURFACE FRONT...WHICH COULD PRODUCE SOME LIGHT SHOWERS OR DRIZZLE AT ABOUT ANY TIME...BUT IT APPEARS THAT THE NEXT ORGANIZED ROUND OF PRECIPITATION WILL HOLD OFF UNTIL LATER THIS AFTERNOON AND MORE SO THIS EVENING AS ANOTHER SHORT WAVE EJECTS AHEAD OF ADVANCING WEST COAST UPPER TROUGH. THUNDERSTORMS CHANCES INCREASE MARKEDLY THIS EVENING AS THIS NEXT WAVE APPROACHES THIS EVENING. SOME OF THESE ELEVATED STORMS TONIGHT MAY ALSO HAVE THE CAPABILITY OF PRODUCING LARGE HAIL WITH STEEP LAPSE RATES AND STRONG DEEP SHEAR. SHOWERS AND THUNDERSTORMS WILL VERY LIKELY BE ONGOING ACROSS THE FORECAST AREA EARLY THURSDAY MORNING...AND THE EFFECT OF THE RESULTING COLD POOL AND CLOUDINESS WILL LIKELY COMPLICATE THE EVOLUTION OF AFTERNOON POTENTIALLY SEVERE CONVECTION ACROSS THE AREA. NONETHELESS...A STRONG AND VERY DYNAMIC SHORT WAVE WILL EMANATE FROM THE CURRENT WEST COAST TROUGH RESULTING IN A DEEPENING SURFACE LOW LIFTING NORTHEAST INTO FAR NORTHERN ILLINOIS OR SOUTHERN WISCONSIN BY THURSDAY EVENING. THE COMBINATION OF THE APPROACHING VIGOROUS SHORT WAVE AND DEEPENING SURFACE LOW WILL LIFT THE CURRENT STATIONARY FRONT NORTHWARD ACROSS THE FORECAST AREA AS A WARM FRONT...WITH THE WARM SECTOR SOUTH OF THE FRONT EXPECTED TO BECOME MODERATELY UNSTABLE DURING THE AFTERNOON AS MLCAPES INCREASE TO 1500-2500 J/KG. STRONG WEST-SOUTHWEST FLOW ALOFT AND BACKED SOUTHERLY WINDS IN LOW LEVELS AHEAD OF THE LOW WILL SUPPLY COPIOUS SHEAR... SUPPORTIVE OF ORGANIZED SEVERE THUNDERSTORMS DEVELOPING DURING THE AFTERNOON AND EARLY EVENING HOURS AHEAD OF THE COLD FRONT WHICH WILL PUSH ACROSS THE CWA BY MIDNIGHT. SPC HAS MAINTAINED A LARGE ENHANCED SEVERE RISK ACROSS THE AREA FOR DAY 2/THURSDAY...WITH SOME UNCERTAINTY REMAINING PRIMARILY TO THE EFFECT OF MORNING CONVECTION ON MESOSCALE SURFACE FEATURES BY THURSDAY AFTERNOON. IF THE DYNAMIC SYSTEM IS ABLE TO OVERCOME STABILIZING INFLUENCE OF EARLIER STORMS...AND IT LIKELY WILL TO SOME DEGREE...THEN A SIGNIFICANT RISK OF DAMAGING WIND...LARGE HAIL AND TORNADOES WILL EXIST. WITH THE SURFACE LOW PASSING NEAR/NORTH OF THE AREA THURSDAY NIGHT...THE COLD FRONT WILL SWEEP EAST DURING THE EVENING AND BRING AN END TO THE SEVERE THREAT AS DRIER/COOLER AIR SPREADS IN. A STRONG NORTHERN STREAM SHORT WAVE IS PROGGED TO DIG ACROSS THE UPPER MIDWEST BEHIND THE FIRST SYSTEM ON FRIDAY...THOUGH DRY AIRMASS AND CAPPING INVERSION IN 700-600 MB LAYER NOTED IN FORECAST SOUNDINGS SHOULD PRECLUDE PRECIP IN ANY ORGANIZED FASHION. TEMPS...SHARP CONTRAST CONTINUES TODAY-TONIGHT WITH EAST- NORTHEAST FLOW NORTH OF THE STATIONARY FRONT AND MOIST/CLOUDY LOW LEVEL AIR MASS. MAY VERY WELL SEE HIGHS TODAY RANGING FROM THE MID-40S IN FAR NORTHEAST IL TO THE LOWER 70S ALONG THE LOT/ILX BORDER. WITH FRONT LIFTING NORTH THURSDAY MUCH OF THE AREA MAY BE IN THE 70S...THOUGH AGAIN MORNING CONVECTION AND RESIDUAL OUTFLOW OR CLOUDS COULD AFFECT MAX TEMPS. COOLER BUT NEAR NORMAL FRIDAY BEHIND THE COLD FRONT...BUT STILL 55-60. RATZER && .LONG TERM... 142 AM CDT SATURDAY THROUGH TUESDAY... THE FIRST FEW PERIODS OF THE EXTENDED LOOK TO BE RELATIVELY BENIGN FOR THE GREAT LAKES REGION...WITH ENSEMBLES DEMONSTRATING MINIMAL SPREAD IN THE 500MB WAVE PATTERN. WEAK TROUGHING WILL BE PIVOTING EAST ACROSS THE MID-ATLANTIC REGION SAT...WITH DIFFLUENT FLOW ARRIVING FOR THE WESTERN GREAT LAKES SAT. THE PATTERN QUICKLY FLATTENS SUN...WITH PRECIP CHANCES RETURNING FOR THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK. ENSEMBLES BEGIN TO POINT TOWARDS A TROUGH TRYING TO DIG INTO THE WESTERN CONUS MON...WHICH COULD SUPPORT A SHORTWAVE DEVELOPING ALONG THE LEE-SIDE OF THE ROCKIES. WITH THE WESTERN GULF OF MEXICO OPEN...MOISTURE SHOULD EASILY LIFT NORTH TOWARDS THE OZARKS INTO IL LATE MON INTO TUE. AS A RESULT INSTABILITY WILL LIKELY INCREASE...SO WILL CONTINUE TO MENTION THUNDER MON/TUE OF NEXT WEEK. WITH THE RELATIVELY ACTIVE FLOW...THE EXTENDED TEMPS MAY END UP SLIGHTLY ABOVE SEASONAL OR MAINLY IN THE LOW/MID 60S. PRIOR TO THE SHORTWAVE ARRIVAL MON...TEMPS MAY PUSH INTO THE UPR 60S OR NEAR 70. OVERNIGHT LOWS WILL ALSO REMAIN MILD. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * IFR VSBY IMPROVES TO MVFR THIS AFTERNOON * LIFR CIGS POTENTIALLY IMPROVING TO IFR THIS EVENING * SCATTERED THUNDERSTORMS DEVELOPING THIS EVENING AND CONTINUING OVERNIGHT * LIFR VIS/CIGS POSSIBLE TONIGHT...IMPROVING THURSDAY MORNING. JEE/IZZI //DISCUSSION...UPDATED 12Z... CIGS/VIS SHOULD SLOWLY IMPROVE THIS MORNING WITH IFR CIGS LIKELY BY THIS AFTERNOON WITH VIS IMPROVING POSSIBLY TO MVFR. CIGS/VIS COULD POSSIBLY LOWER BACK TO LIFR THIS EVENING INTO EARLY OVERNIGHT BUT CONFIDENCE IS LOW. COMPLEX OF THUNDERSTORMS ACROSS EASTERN IL INTO NORTH CENTRAL INDIANA WILL CONTINUE TO MOVE EAST/SOUTHEAST AND AWAY FROM THE AREA THIS MORNING. SOME DRIZZLE THIS MORNING AND PERHAPS A BRIEF SHOWER BUT THE DAYLIGHT HOURS APPEAR DRY FOR THE TERMINALS. FOCUS SHIFTS TO COMPLEX OF THUNDERSTORMS OVER NORTHEAST MO...WHICH WILL LIKELY MOVE EAST/NORTHEAST AND INTO PARTS OF WEST CENTRAL IL MID/ LATE AFTERNOON. ADDITIONAL THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS NORTHERN IL THIS EVENING AND CONTINUE INTO THE OVERNIGHT HOURS. CONFIDENCE REGARDING TIMING/LOCATION/COVERAGE IS STILL LOW ENOUGH THAT OPTED TO CONTINUE WITH A LONGER DURATION OF VICINITY THUNDER. GENERALLY EASTERLY WINDS WILL CONTINUE THRU THIS EVENING WITH SPEEDS LIKELY AT OR ABOVE 10 KTS. WINDS WILL BEGIN TO TURN SOUTHEAST LATER THIS EVENING AND OVERNIGHT...THEN MORE SOUTH/ SOUTHWEST THURSDAY MORNING AS A WARM FRONT LIFTS THROUGH THE TERMINALS. WHEN THIS OCCURS...EXPECT RAPID IMPROVEMENT THROUGH MVFR CIGS AND LIKELY TO PREVAILING VFR CIGS...OUTSIDE PRECIP... INTO THURSDAY MORNING. CMS //ORD AND MDW CONFIDENCE...UPDATED 14Z... * MEDIUM CONFIDENCE IN VERY SLOW IMPROVEMENT IN CIGS/VSBY THROUGH THIS EVENING * MEDIUM IN WINDS THROUGH THE PERIOD. * MEDIUM CONFIDENCE IN TS TONIGHT...LOW FOR TIMING AND COVERAGE. JEE/CMS/IZZI //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... * THURSDAY NIGHT...STRONG TSRA IN THE EVENING. MVFR POSSIBLE. STRONG/GUSTY SOUTHWEST WINDS BECOMING WEST. * FRIDAY...DRY/VFR. STRONG/GUSTY WEST WINDS. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY...CHANCE OF SHRA. SOUTHWEST WINDS. && .MARINE... 415 AM...A FRONTAL BOUNDARY WILL REMAIN STATIONARY JUST SOUTH OF LAKE MICHIGAN INTO THIS EVENING...THEN BEGIN TO LIFT NORTH ACROSS THE LAKE LATE TONIGHT AND THURSDAY AS A WARM FRONT AS LOW PRESSURE OVER THE PLAINS MOVES NORTHEAST TONIGHT AND THURSDAY...REACHING NORTHERN LAKE MICHIGAN BY FRIDAY MORNING. NORTHEAST WINDS WILL REMAIN IN THE 20-25KT RANGE TODAY...WITH SOME HIGHER GUSTS POSSIBLE. WINDS WILL SLOWLY DIMINISH LATE TONIGHT INTO THURSDAY MORNING...THEN AS WINDS SHIFTING SOUTHWESTERLY THURSDAY AFTERNOON AND ESPECIALLY THURSDAY EVENING...THEY WILL INCREASE TO 30 KT... SHIFTING WESTERLY THURSDAY NIGHT AFTER A COLD FRONT MOVES ACROSS THE LAKE. WINDS WILL SLOWLY DIMINISH FRIDAY AFTERNOON INTO FRIDAY EVENING...THEN BECOME LIGHT SATURDAY AS HIGH PRESSURE MOVES ACROSS THE REGION. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 5 AM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1224 PM CDT Wed Apr 8 2015 .UPDATE... ISSUED AT 1034 AM CDT WED APR 8 2015 Have made some adjustments to PoPs and Wx based on position of boundaries from earlier convection and the anticipated evolution of incoming wave. High temperature forecasts remain reasonable. Elevated boundary over southeast forecast area continues to produce isolated thunderstorms as it sags south. Next system is moving through Missouri this morning. Leading edge is weakening as it moves into more stable air in wake of morning convection and fog. This trend should change as temps rise well into the 70s and dew pts reach well into 60s over much of the southern two-thirds of CWA. Lastest HRRR suggests that best chances for afternoon storms should remain south of I-72. && .SHORT TERM...(Today) ISSUED AT 255 AM CDT WED APR 8 2015 Latest surface analysis indicates the frontal boundary that was holding stationary over south central Illinois has shifted further north early this morning as a weak wave of low pressure was approaching west central Illinois. Scattered convection has been occurring north of the boundary over parts of east central Iowa east into our far northern counties with some nickel hail reported over the past hour around Lacon in Marshall county. We expect the scattered convection to continue into the morning hours as the wave rides east along the boundary. As the surface low shifts to our east later this morning, there may actually be a southward push to the front which is going to cause some significant problems with respect to the afternoon temperatures, especially along and north of I-74. The latest HRRR does indicate another weak wave forming to our west along the boundary early this afternoon with another complex of storms approaching west central IL. Not sure if this particular complex of storms will ride along the boundary into central Illinois or dive more southeast into the higher instability air mass south of the front. POPs will increase again this afternoon in response to this secondary wave approaching from the west. Severe potential increases this afternoon thru this evening as the boundary gets a push northward as the more significant shortwave pushes into the Plains. With the warm front expected to edge across the area this afternoon and evening, damaging wind gusts, large hail and isolated tornadoes will all be possible. The tornado threat looks tied more into areas along and just north of the warm front later this afternoon and evening. Coolest temps north of I-74 where more of an easterly flow will prevail, while south of the boundary, a blend of the MET/MAV guid seems reasonable at this point. && .LONG TERM...(Tonight through Tuesday) ISSUED AT 255 AM CDT WED APR 8 2015 Severe weather threat through Thursday evening continues to dominate the first part of the forecast. Current upper low moving into northwest Nevada will open up but remain a fairly sharp wave as it traverses the Plains on Thursday. This will help develop a surface low over western Kansas this evening, which will surge northeast and shove the frontal boundary back northward tonight. The trailing cold front will sweep from west to east across the state Thursday evening as a result. Convection to our southwest expected to expand northeastward into the mid-Mississippi Valley this evening. Latest SPC Day1 outlook extended the slight risk across the entire CWA, with an enhanced risk of severe storms from basically Springfield-Peoria westward. This enhanced risk covers the entire area on Thursday, with high-resolution models focusing on the mid-afternoon through early evening time frame as the best potential in our area. Short period of cooler and drier weather on tap for the first part of the weekend, as high pressure drifts across the Midwest. However, longer range models showing extended periods of rain chances early next week. The GFS and ECMWF have a sizable range on the position of a frontal boundary that will be setting up Sunday night and Monday, both starting off roughly along I-70 but the GFS shows a much stronger surge to the north by Tuesday. However, with both favoring some sort of precip, have kept healthy rain chances in the forecast for early next week. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) ISSUED AT 1223 PM CDT WED APR 8 2015 Next cluster of storms moving into western Illinois at this time. As they do so they will be encountering more unstable conditions once they move east of the Illinois river and into the warm sector. Some of the convection may become significant with convective wind shear. Another convective cluster is expected overnight however there is more uncertianty on the track of the overnight system as it may impact areas south of the central Illinois terminals. Will mainly reflect this uncertainty by including a VCTS rather than a dominant group. Winds will also be quite uncertian as the frontal boundary in the area will be modulated by the track of the clusters. Abundant boundary layer moisture both near and north of the front will keep CIGS in place with IFR to at best MVFR conditions. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Barker SHORT TERM...Smith LONG TERM...Geelhart AVIATION...Barker
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1115 AM CDT WED APR 8 2015 .SHORT TERM... 347 AM CDT THROUGH THURSDAY... TODAY THROUGH FRIDAY NIGHT... MAIN FOCUS IS ON PERIODS OF CONVECTION...PARTICULARLY THIS MORNING ACROSS PART OF THE FORECAST AREAS...AND ACROSS THE ENTIRE AREA TONIGHT INTO THURSDAY. SEVERE WEATHER THREAT REMAINS OF GREAT CONCERN THURSDAY AFTERNOON AND EVENING. EARLY MORNING SURFACE ANALYSIS DEPICTS LOW PRESSURE OVER NORTHEASTERN MISSOURI...WITH AN INVERTED TROUGH EXTENDING NORTHEAST ACROSS SOUTHEAST WI/LAKE MICHIGAN. THESE FEATURES APPEAR TO BE ASSOCIATED WITH A COUPLE OF MID-LEVEL SHORT WAVE TROUGHS PROPAGATING ACROSS THE REGION IN BROAD WEST-SOUTHWESTERLY FLOW ALOFT. A CLUSTER OF THUNDERSTORMS HAD DEVELOPED ACROSS SOUTHEAST IOWA LAST EVENING IN LOW LEVEL WARM/MOIST ADVECTION MAXIMA NORTHEAST OF THE SURFACE LOW...AND CONTINUE TO PERSIST AND EXPAND SLOWLY EASTWARD ACROSS PARTS OF ILLINOIS EARLY THIS MORNING ON 30 KT 925 MB JET AHEAD OF SHORT WAVE. THESE STORMS ARE LIKELY TO CONTINUE TO DEVELOP EASTWARD ACROSS MAINLY THE SOUTHERN TWO THIRDS OR SO OF THE CWA EARLY THIS MORNING AS THE SURFACE WAVE MOVE THROUGH THE AREA. SPC MESOANALYSIS DATA INDICATES UPSTREAM AIR MASS CHARACTERIZED BY STEEP MID-LEVEL LAPSE RATES IN EXCESS OF 7.5 C/KM YIELDING 1000-1500 J/KG OF ELEVATED MUCAPE...AND ROUGHLY 40-45 KT OF EFFECTIVE DEEP LAYER BULK SHEAR. SOME OF THE STRONGER CORES MAY BE CAPABLE OF PRODUCING SOME MARGINAL HAIL THIS MORNING...THOUGH AN OVERALL WEAKENING TREND IS EXPECTED AS THE LOW LEVEL FLOW VEERS MORE WESTERLY AND DECREASES AND REDUCES LOW LEVEL MOISTURE TRANSPORT/THETA-E ADVECTION ACROSS OUR SOUTH AND SOUTHEAST COUNTIES. THIS TREND IS SUPPORTED BY HIGH-RES HRRR/RAP GUIDANCE WHICH INDICATE ACTIVITY MOVING ACROSS THE AREA THROUGH 13-14Z. MOIST/SATURATED LOW LEVEL AIR MASS HAS ALSO REDUCED VISIBILITY IN FOG OVER THE PAST SEVERAL HOURS...WITH SOME PATCHES OF DENSE FOG NOTED. MAY HAVE TO CONSIDER A HEADLINE...THOUGH MORNING SHOWERS MAY HELP RAISE VISIBILITY SOMEWHAT AND WILL CONTINUE TO MONITOR. NOT MUCH IS EXPECTED IN THE WAY OF ORGANIZED PRECIP FROM MID- MORNING INTO THIS AFTERNOON...WITH PASSAGE OF THE SHORT WAVE AND WEAKENING OF THE SURFACE WAVE ALONG THE FRONT TO OUR SOUTH. WEAK BUT PERSISTENT SOUTHWEST FLOW WILL CONTINUE ABOVE THE SHALLOW COOL BOUNDARY LAYER NORTH OF THE SURFACE FRONT...WHICH COULD PRODUCE SOME LIGHT SHOWERS OR DRIZZLE AT ABOUT ANY TIME...BUT IT APPEARS THAT THE NEXT ORGANIZED ROUND OF PRECIPITATION WILL HOLD OFF UNTIL LATER THIS AFTERNOON AND MORE SO THIS EVENING AS ANOTHER SHORT WAVE EJECTS AHEAD OF ADVANCING WEST COAST UPPER TROUGH. THUNDERSTORMS CHANCES INCREASE MARKEDLY THIS EVENING AS THIS NEXT WAVE APPROACHES THIS EVENING. SOME OF THESE ELEVATED STORMS TONIGHT MAY ALSO HAVE THE CAPABILITY OF PRODUCING LARGE HAIL WITH STEEP LAPSE RATES AND STRONG DEEP SHEAR. SHOWERS AND THUNDERSTORMS WILL VERY LIKELY BE ONGOING ACROSS THE FORECAST AREA EARLY THURSDAY MORNING...AND THE EFFECT OF THE RESULTING COLD POOL AND CLOUDINESS WILL LIKELY COMPLICATE THE EVOLUTION OF AFTERNOON POTENTIALLY SEVERE CONVECTION ACROSS THE AREA. NONETHELESS...A STRONG AND VERY DYNAMIC SHORT WAVE WILL EMANATE FROM THE CURRENT WEST COAST TROUGH RESULTING IN A DEEPENING SURFACE LOW LIFTING NORTHEAST INTO FAR NORTHERN ILLINOIS OR SOUTHERN WISCONSIN BY THURSDAY EVENING. THE COMBINATION OF THE APPROACHING VIGOROUS SHORT WAVE AND DEEPENING SURFACE LOW WILL LIFT THE CURRENT STATIONARY FRONT NORTHWARD ACROSS THE FORECAST AREA AS A WARM FRONT...WITH THE WARM SECTOR SOUTH OF THE FRONT EXPECTED TO BECOME MODERATELY UNSTABLE DURING THE AFTERNOON AS MLCAPES INCREASE TO 1500-2500 J/KG. STRONG WEST-SOUTHWEST FLOW ALOFT AND BACKED SOUTHERLY WINDS IN LOW LEVELS AHEAD OF THE LOW WILL SUPPLY COPIOUS SHEAR... SUPPORTIVE OF ORGANIZED SEVERE THUNDERSTORMS DEVELOPING DURING THE AFTERNOON AND EARLY EVENING HOURS AHEAD OF THE COLD FRONT WHICH WILL PUSH ACROSS THE CWA BY MIDNIGHT. SPC HAS MAINTAINED A LARGE ENHANCED SEVERE RISK ACROSS THE AREA FOR DAY 2/THURSDAY...WITH SOME UNCERTAINTY REMAINING PRIMARILY TO THE EFFECT OF MORNING CONVECTION ON MESOSCALE SURFACE FEATURES BY THURSDAY AFTERNOON. IF THE DYNAMIC SYSTEM IS ABLE TO OVERCOME STABILIZING INFLUENCE OF EARLIER STORMS...AND IT LIKELY WILL TO SOME DEGREE...THEN A SIGNIFICANT RISK OF DAMAGING WIND...LARGE HAIL AND TORNADOES WILL EXIST. WITH THE SURFACE LOW PASSING NEAR/NORTH OF THE AREA THURSDAY NIGHT...THE COLD FRONT WILL SWEEP EAST DURING THE EVENING AND BRING AN END TO THE SEVERE THREAT AS DRIER/COOLER AIR SPREADS IN. A STRONG NORTHERN STREAM SHORT WAVE IS PROGGED TO DIG ACROSS THE UPPER MIDWEST BEHIND THE FIRST SYSTEM ON FRIDAY...THOUGH DRY AIRMASS AND CAPPING INVERSION IN 700-600 MB LAYER NOTED IN FORECAST SOUNDINGS SHOULD PRECLUDE PRECIP IN ANY ORGANIZED FASHION. TEMPS...SHARP CONTRAST CONTINUES TODAY-TONIGHT WITH EAST- NORTHEAST FLOW NORTH OF THE STATIONARY FRONT AND MOIST/CLOUDY LOW LEVEL AIR MASS. MAY VERY WELL SEE HIGHS TODAY RANGING FROM THE MID-40S IN FAR NORTHEAST IL TO THE LOWER 70S ALONG THE LOT/ILX BORDER. WITH FRONT LIFTING NORTH THURSDAY MUCH OF THE AREA MAY BE IN THE 70S...THOUGH AGAIN MORNING CONVECTION AND RESIDUAL OUTFLOW OR CLOUDS COULD AFFECT MAX TEMPS. COOLER BUT NEAR NORMAL FRIDAY BEHIND THE COLD FRONT...BUT STILL 55-60. RATZER && .LONG TERM... 142 AM CDT SATURDAY THROUGH TUESDAY... THE FIRST FEW PERIODS OF THE EXTENDED LOOK TO BE RELATIVELY BENIGN FOR THE GREAT LAKES REGION...WITH ENSEMBLES DEMONSTRATING MINIMAL SPREAD IN THE 500MB WAVE PATTERN. WEAK TROUGHING WILL BE PIVOTING EAST ACROSS THE MID-ATLANTIC REGION SAT...WITH DIFFLUENT FLOW ARRIVING FOR THE WESTERN GREAT LAKES SAT. THE PATTERN QUICKLY FLATTENS SUN...WITH PRECIP CHANCES RETURNING FOR THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK. ENSEMBLES BEGIN TO POINT TOWARDS A TROUGH TRYING TO DIG INTO THE WESTERN CONUS MON...WHICH COULD SUPPORT A SHORTWAVE DEVELOPING ALONG THE LEE-SIDE OF THE ROCKIES. WITH THE WESTERN GULF OF MEXICO OPEN...MOISTURE SHOULD EASILY LIFT NORTH TOWARDS THE OZARKS INTO IL LATE MON INTO TUE. AS A RESULT INSTABILITY WILL LIKELY INCREASE...SO WILL CONTINUE TO MENTION THUNDER MON/TUE OF NEXT WEEK. WITH THE RELATIVELY ACTIVE FLOW...THE EXTENDED TEMPS MAY END UP SLIGHTLY ABOVE SEASONAL OR MAINLY IN THE LOW/MID 60S. PRIOR TO THE SHORTWAVE ARRIVAL MON...TEMPS MAY PUSH INTO THE UPR 60S OR NEAR 70. OVERNIGHT LOWS WILL ALSO REMAIN MILD. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * IFR VSBY IN FOG IMPROVES TO MVFR DURING THE AFTERNOON * LIFR CIGS POTENTIALLY IMPROVING TO IFR DURING THIS AFTERNOON OR EVENING * SCATTERED THUNDERSTORMS DEVELOPING LATE THIS EVENING AND OVERNIGHT * LIFR VIS/CIGS POSSIBLE TONIGHT...IMPROVING THURSDAY MORNING. JEE/IZZI //DISCUSSION...UPDATED 12Z... CIGS/VIS SHOULD SLOWLY IMPROVE THIS MORNING WITH IFR CIGS LIKELY BY THIS AFTERNOON WITH VIS IMPROVING POSSIBLY TO MVFR. CIGS/VIS COULD POSSIBLY LOWER BACK TO LIFR THIS EVENING INTO EARLY OVERNIGHT BUT CONFIDENCE IS LOW. COMPLEX OF THUNDERSTORMS ACROSS EASTERN IL INTO NORTH CENTRAL INDIANA WILL CONTINUE TO MOVE EAST/SOUTHEAST AND AWAY FROM THE AREA THIS MORNING. SOME DRIZZLE THIS MORNING AND PERHAPS A BRIEF SHOWER BUT THE DAYLIGHT HOURS APPEAR DRY FOR THE TERMINALS. FOCUS SHIFTS TO COMPLEX OF THUNDERSTORMS OVER NORTHEAST MO...WHICH WILL LIKELY MOVE EAST/NORTHEAST AND INTO PARTS OF WEST CENTRAL IL MID/ LATE AFTERNOON. ADDITIONAL THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS NORTHERN IL THIS EVENING AND CONTINUE INTO THE OVERNIGHT HOURS. CONFIDENCE REGARDING TIMING/LOCATION/COVERAGE IS STILL LOW ENOUGH THAT OPTED TO CONTINUE WITH A LONGER DURATION OF VICINITY THUNDER. GENERALLY EASTERLY WINDS WILL CONTINUE THRU THIS EVENING WITH SPEEDS LIKELY AT OR ABOVE 10 KTS. WINDS WILL BEGIN TO TURN SOUTHEAST LATER THIS EVENING AND OVERNIGHT...THEN MORE SOUTH/ SOUTHWEST THURSDAY MORNING AS A WARM FRONT LIFTS THROUGH THE TERMINALS. WHEN THIS OCCURS...EXPECT RAPID IMPROVEMENT THROUGH MVFR CIGS AND LIKELY TO PREVAILING VFR CIGS...OUTSIDE PRECIP... INTO THURSDAY MORNING. CMS //ORD AND MDW CONFIDENCE...UPDATED 16Z... * MEDIUM CONFIDENCE IN SLOW IMPROVMENT IN CIGS/VSBY REST OF TODAY * MEDIUM TO HIGH IN WINDS THROUGH TONIGHT...MEDIUM TO LOW WITH WINDS ON THURSDAY MORNING WITH TIMING OF WARM FRONT. * MEDIUM CONFIDENCE IN TS OVERNIGHT...LOW FOR TIMING AND COVERAGE. JEE/CMS/IZZI/KMH/EJL //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... * THURSDAY NIGHT...STRONG TSRA IN THE EVENING. MVFR POSSIBLE. STRONG/GUSTY SOUTHWEST WINDS BECOMING WEST. * FRIDAY...DRY/VFR. STRONG/GUSTY WEST WINDS. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY...CHANCE OF SHRA. SOUTHWEST WINDS. && .MARINE... 415 AM...A FRONTAL BOUNDARY WILL REMAIN STATIONARY JUST SOUTH OF LAKE MICHIGAN INTO THIS EVENING...THEN BEGIN TO LIFT NORTH ACROSS THE LAKE LATE TONIGHT AND THURSDAY AS A WARM FRONT AS LOW PRESSURE OVER THE PLAINS MOVES NORTHEAST TONIGHT AND THURSDAY...REACHING NORTHERN LAKE MICHIGAN BY FRIDAY MORNING. NORTHEAST WINDS WILL REMAIN IN THE 20-25KT RANGE TODAY...WITH SOME HIGHER GUSTS POSSIBLE. WINDS WILL SLOWLY DIMINISH LATE TONIGHT INTO THURSDAY MORNING...THEN AS WINDS SHIFTING SOUTHWESTERLY THURSDAY AFTERNOON AND ESPECIALLY THURSDAY EVENING...THEY WILL INCREASE TO 30 KT... SHIFTING WESTERLY THURSDAY NIGHT AFTER A COLD FRONT MOVES ACROSS THE LAKE. WINDS WILL SLOWLY DIMINISH FRIDAY AFTERNOON INTO FRIDAY EVENING...THEN BECOME LIGHT SATURDAY AS HIGH PRESSURE MOVES ACROSS THE REGION. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 5 AM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1034 AM CDT Wed Apr 8 2015 .UPDATE... ISSUED AT 1034 AM CDT WED APR 8 2015 Have made some adjustments to PoPs and Wx based on position of boundaries from earlier convection and the anticipated evolution of incoming wave. High temperature forecasts remain reasonable. Elevated boundary over southeast forecast area continues to produce isolated thunderstorms as it sags south. Next system is moving through Missouri this morning. Leading edge is weakening as it moves into more stable air in wake of morning convection and fog. This trend should change as temps rise well into the 70s and dew pts reach well into 60s over much of the southern two-thirds of CWA. Lastest HRRR suggests that best chances for afternoon storms should remain south of I-72. && .SHORT TERM...(Today) ISSUED AT 255 AM CDT WED APR 8 2015 Latest surface analysis indicates the frontal boundary that was holding stationary over south central Illinois has shifted further north early this morning as a weak wave of low pressure was approaching west central Illinois. Scattered convection has been occurring north of the boundary over parts of east central Iowa east into our far northern counties with some nickel hail reported over the past hour around Lacon in Marshall county. We expect the scattered convection to continue into the morning hours as the wave rides east along the boundary. As the surface low shifts to our east later this morning, there may actually be a southward push to the front which is going to cause some significant problems with respect to the afternoon temperatures, especially along and north of I-74. The latest HRRR does indicate another weak wave forming to our west along the boundary early this afternoon with another complex of storms approaching west central IL. Not sure if this particular complex of storms will ride along the boundary into central Illinois or dive more southeast into the higher instability air mass south of the front. POPs will increase again this afternoon in response to this secondary wave approaching from the west. Severe potential increases this afternoon thru this evening as the boundary gets a push northward as the more significant shortwave pushes into the Plains. With the warm front expected to edge across the area this afternoon and evening, damaging wind gusts, large hail and isolated tornadoes will all be possible. The tornado threat looks tied more into areas along and just north of the warm front later this afternoon and evening. Coolest temps north of I-74 where more of an easterly flow will prevail, while south of the boundary, a blend of the MET/MAV guid seems reasonable at this point. && .LONG TERM...(Tonight through Tuesday) ISSUED AT 255 AM CDT WED APR 8 2015 Severe weather threat through Thursday evening continues to dominate the first part of the forecast. Current upper low moving into northwest Nevada will open up but remain a fairly sharp wave as it traverses the Plains on Thursday. This will help develop a surface low over western Kansas this evening, which will surge northeast and shove the frontal boundary back northward tonight. The trailing cold front will sweep from west to east across the state Thursday evening as a result. Convection to our southwest expected to expand northeastward into the mid-Mississippi Valley this evening. Latest SPC Day1 outlook extended the slight risk across the entire CWA, with an enhanced risk of severe storms from basically Springfield-Peoria westward. This enhanced risk covers the entire area on Thursday, with high-resolution models focusing on the mid-afternoon through early evening time frame as the best potential in our area. Short period of cooler and drier weather on tap for the first part of the weekend, as high pressure drifts across the Midwest. However, longer range models showing extended periods of rain chances early next week. The GFS and ECMWF have a sizable range on the position of a frontal boundary that will be setting up Sunday night and Monday, both starting off roughly along I-70 but the GFS shows a much stronger surge to the north by Tuesday. However, with both favoring some sort of precip, have kept healthy rain chances in the forecast for early next week. && .AVIATION...(For the 12Z TAFS through 12Z Thursday morning) ISSUED AT 615 AM CDT WED APR 8 2015 Frontal boundary located over the northern portion of the forecast area this morning will be the focus for periods of showers and thunderstorms along with LIFR cigs and vsbys with some of the heavy thunderstorms. Outside of the convection, and south of the frontal boundary, we will see a period of VFR cigs today with the main band of convection moving in after 21z but scattered in nature, so will continue to handle with VCTS until we see how the storms develop to our west later today. Surface winds will be quite variable in direction and speed in and near the thunderstorms today. Most of our area will see southeast winds at 10 to 15 kts today into tonight. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Barker SHORT TERM...Smith LONG TERM...Geelhart AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
650 AM CDT WED APR 8 2015 .SHORT TERM... 347 AM CDT THROUGH THURSDAY... TODAY THROUGH FRIDAY NIGHT... MAIN FOCUS IS ON PERIODS OF CONVECTION...PARTICULARLY THIS MORNING ACROSS PART OF THE FORECAST AREAS...AND ACROSS THE ENTIRE AREA TONIGHT INTO THURSDAY. SEVERE WEATHER THREAT REMAINS OF GREAT CONCERN THURSDAY AFTERNOON AND EVENING. EARLY MORNING SURFACE ANALYSIS DEPICTS LOW PRESSURE OVER NORTHEASTERN MISSOURI...WITH AN INVERTED TROUGH EXTENDING NORTHEAST ACROSS SOUTHEAST WI/LAKE MICHIGAN. THESE FEATURES APPEAR TO BE ASSOCIATED WITH A COUPLE OF MID-LEVEL SHORT WAVE TROUGHS PROPAGATING ACROSS THE REGION IN BROAD WEST-SOUTHWESTERLY FLOW ALOFT. A CLUSTER OF THUNDERSTORMS HAD DEVELOPED ACROSS SOUTHEAST IOWA LAST EVENING IN LOW LEVEL WARM/MOIST ADVECTION MAXIMA NORTHEAST OF THE SURFACE LOW...AND CONTINUE TO PERSIST AND EXPAND SLOWLY EASTWARD ACROSS PARTS OF ILLINOIS EARLY THIS MORNING ON 30 KT 925 MB JET AHEAD OF SHORT WAVE. THESE STORMS ARE LIKELY TO CONTINUE TO DEVELOP EASTWARD ACROSS MAINLY THE SOUTHERN TWO THIRDS OR SO OF THE CWA EARLY THIS MORNING AS THE SURFACE WAVE MOVE THROUGH THE AREA. SPC MESOANALYSIS DATA INDICATES UPSTREAM AIR MASS CHARACTERIZED BY STEEP MID-LEVEL LAPSE RATES IN EXCESS OF 7.5 C/KM YIELDING 1000-1500 J/KG OF ELEVATED MUCAPE...AND ROUGHLY 40-45 KT OF EFFECTIVE DEEP LAYER BULK SHEAR. SOME OF THE STRONGER CORES MAY BE CAPABLE OF PRODUCING SOME MARGINAL HAIL THIS MORNING...THOUGH AN OVERALL WEAKENING TREND IS EXPECTED AS THE LOW LEVEL FLOW VEERS MORE WESTERLY AND DECREASES AND REDUCES LOW LEVEL MOISTURE TRANSPORT/THETA-E ADVECTION ACROSS OUR SOUTH AND SOUTHEAST COUNTIES. THIS TREND IS SUPPORTED BY HIGH-RES HRRR/RAP GUIDANCE WHICH INDICATE ACTIVITY MOVING ACROSS THE AREA THROUGH 13-14Z. MOIST/SATURATED LOW LEVEL AIR MASS HAS ALSO REDUCED VISIBILITY IN FOG OVER THE PAST SEVERAL HOURS...WITH SOME PATCHES OF DENSE FOG NOTED. MAY HAVE TO CONSIDER A HEADLINE...THOUGH MORNING SHOWERS MAY HELP RAISE VISIBILITY SOMEWHAT AND WILL CONTINUE TO MONITOR. NOT MUCH IS EXPECTED IN THE WAY OF ORGANIZED PRECIP FROM MID- MORNING INTO THIS AFTERNOON...WITH PASSAGE OF THE SHORT WAVE AND WEAKENING OF THE SURFACE WAVE ALONG THE FRONT TO OUR SOUTH. WEAK BUT PERSISTENT SOUTHWEST FLOW WILL CONTINUE ABOVE THE SHALLOW COOL BOUNDARY LAYER NORTH OF THE SURFACE FRONT...WHICH COULD PRODUCE SOME LIGHT SHOWERS OR DRIZZLE AT ABOUT ANY TIME...BUT IT APPEARS THAT THE NEXT ORGANIZED ROUND OF PRECIPITATION WILL HOLD OFF UNTIL LATER THIS AFTERNOON AND MORE SO THIS EVENING AS ANOTHER SHORT WAVE EJECTS AHEAD OF ADVANCING WEST COAST UPPER TROUGH. THUNDERSTORMS CHANCES INCREASE MARKEDLY THIS EVENING AS THIS NEXT WAVE APPROACHES THIS EVENING. SOME OF THESE ELEVATED STORMS TONIGHT MAY ALSO HAVE THE CAPABILITY OF PRODUCING LARGE HAIL WITH STEEP LAPSE RATES AND STRONG DEEP SHEAR. SHOWERS AND THUNDERSTORMS WILL VERY LIKELY BE ONGOING ACROSS THE FORECAST AREA EARLY THURSDAY MORNING...AND THE EFFECT OF THE RESULTING COLD POOL AND CLOUDINESS WILL LIKELY COMPLICATE THE EVOLUTION OF AFTERNOON POTENTIALLY SEVERE CONVECTION ACROSS THE AREA. NONETHELESS...A STRONG AND VERY DYNAMIC SHORT WAVE WILL EMANATE FROM THE CURRENT WEST COAST TROUGH RESULTING IN A DEEPENING SURFACE LOW LIFTING NORTHEAST INTO FAR NORTHERN ILLINOIS OR SOUTHERN WISCONSIN BY THURSDAY EVENING. THE COMBINATION OF THE APPROACHING VIGOROUS SHORT WAVE AND DEEPENING SURFACE LOW WILL LIFT THE CURRENT STATIONARY FRONT NORTHWARD ACROSS THE FORECAST AREA AS A WARM FRONT...WITH THE WARM SECTOR SOUTH OF THE FRONT EXPECTED TO BECOME MODERATELY UNSTABLE DURING THE AFTERNOON AS MLCAPES INCREASE TO 1500-2500 J/KG. STRONG WEST-SOUTHWEST FLOW ALOFT AND BACKED SOUTHERLY WINDS IN LOW LEVELS AHEAD OF THE LOW WILL SUPPLY COPIOUS SHEAR... SUPPORTIVE OF ORGANIZED SEVERE THUNDERSTORMS DEVELOPING DURING THE AFTERNOON AND EARLY EVENING HOURS AHEAD OF THE COLD FRONT WHICH WILL PUSH ACROSS THE CWA BY MIDNIGHT. SPC HAS MAINTAINED A LARGE ENHANCED SEVERE RISK ACROSS THE AREA FOR DAY 2/THURSDAY...WITH SOME UNCERTAINTY REMAINING PRIMARILY TO THE EFFECT OF MORNING CONVECTION ON MESOSCALE SURFACE FEATURES BY THURSDAY AFTERNOON. IF THE DYNAMIC SYSTEM IS ABLE TO OVERCOME STABILIZING INFLUENCE OF EARLIER STORMS...AND IT LIKELY WILL TO SOME DEGREE...THEN A SIGNIFICANT RISK OF DAMAGING WIND...LARGE HAIL AND TORNADOES WILL EXIST. WITH THE SURFACE LOW PASSING NEAR/NORTH OF THE AREA THURSDAY NIGHT...THE COLD FRONT WILL SWEEP EAST DURING THE EVENING AND BRING AN END TO THE SEVERE THREAT AS DRIER/COOLER AIR SPREADS IN. A STRONG NORTHERN STREAM SHORT WAVE IS PROGGED TO DIG ACROSS THE UPPER MIDWEST BEHIND THE FIRST SYSTEM ON FRIDAY...THOUGH DRY AIRMASS AND CAPPING INVERSION IN 700-600 MB LAYER NOTED IN FORECAST SOUNDINGS SHOULD PRECLUDE PRECIP IN ANY ORGANIZED FASHION. TEMPS...SHARP CONTRAST CONTINUES TODAY-TONIGHT WITH EAST- NORTHEAST FLOW NORTH OF THE STATIONARY FRONT AND MOIST/CLOUDY LOW LEVEL AIR MASS. MAY VERY WELL SEE HIGHS TODAY RANGING FROM THE MID-40S IN FAR NORTHEAST IL TO THE LOWER 70S ALONG THE LOT/ILX BORDER. WITH FRONT LIFTING NORTH THURSDAY MUCH OF THE AREA MAY BE IN THE 70S...THOUGH AGAIN MORNING CONVECTION AND RESIDUAL OUTFLOW OR CLOUDS COULD AFFECT MAX TEMPS. COOLER BUT NEAR NORMAL FRIDAY BEHIND THE COLD FRONT...BUT STILL 55-60. RATZER && .LONG TERM... 142 AM CDT SATURDAY THROUGH TUESDAY... THE FIRST FEW PERIODS OF THE EXTENDED LOOK TO BE RELATIVELY BENIGN FOR THE GREAT LAKES REGION...WITH ENSEMBLES DEMONSTRATING MINIMAL SPREAD IN THE 500MB WAVE PATTERN. WEAK TROUGHING WILL BE PIVOTING EAST ACROSS THE MID-ATLANTIC REGION SAT...WITH DIFFLUENT FLOW ARRIVING FOR THE WESTERN GREAT LAKES SAT. THE PATTERN QUICKLY FLATTENS SUN...WITH PRECIP CHANCES RETURNING FOR THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK. ENSEMBLES BEGIN TO POINT TOWARDS A TROUGH TRYING TO DIG INTO THE WESTERN CONUS MON...WHICH COULD SUPPORT A SHORTWAVE DEVELOPING ALONG THE LEE-SIDE OF THE ROCKIES. WITH THE WESTERN GULF OF MEXICO OPEN...MOISTURE SHOULD EASILY LIFT NORTH TOWARDS THE OZARKS INTO IL LATE MON INTO TUE. AS A RESULT INSTABILITY WILL LIKELY INCREASE...SO WILL CONTINUE TO MENTION THUNDER MON/TUE OF NEXT WEEK. WITH THE RELATIVELY ACTIVE FLOW...THE EXTENDED TEMPS MAY END UP SLIGHTLY ABOVE SEASONAL OR MAINLY IN THE LOW/MID 60S. PRIOR TO THE SHORTWAVE ARRIVAL MON...TEMPS MAY PUSH INTO THE UPR 60S OR NEAR 70. OVERNIGHT LOWS WILL ALSO REMAIN MILD. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * LIFR CIGS/VIS IMPROVING TO IFR THIS AFTERNOON. * SCATTERED THUNDERSTORMS DEVELOPING THIS EVENING AND CONTINUING OVERNIGHT. * LIFR VIS/CIGS POSSIBLE TONIGHT...IMPROVING THURSDAY MORNING. //DISCUSSION...UPDATED 12Z... CIGS/VIS SHOULD SLOWLY IMPROVE THIS MORNING WITH IFR CIGS LIKELY BY THIS AFTERNOON WITH VIS IMPROVING POSSIBLY TO MVFR. CIGS/VIS COULD POSSIBLY LOWER BACK TO LIFR THIS EVENING INTO EARLY OVERNIGHT BUT CONFIDENCE IS LOW. COMPLEX OF THUNDERSTORMS ACROSS EASTERN IL INTO NORTH CENTRAL INDIANA WILL CONTINUE TO MOVE EAST/SOUTHEAST AND AWAY FROM THE AREA THIS MORNING. SOME DRIZZLE THIS MORNING AND PERHAPS A BRIEF SHOWER BUT THE DAYLIGHT HOURS APPEAR DRY FOR THE TERMINALS. FOCUS SHIFTS TO COMPLEX OF THUNDERSTORMS OVER NORTHEAST MO...WHICH WILL LIKELY MOVE EAST/NORTHEAST AND INTO PARTS OF WEST CENTRAL IL MID/ LATE AFTERNOON. ADDITIONAL THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS NORTHERN IL THIS EVENING AND CONTINUE INTO THE OVERNIGHT HOURS. CONFIDENCE REGARDING TIMING/LOCATION/COVERAGE IS STILL LOW ENOUGH THAT OPTED TO CONTINUE WITH A LONGER DURATION OF VICINITY THUNDER. GENERALLY EASTERLY WINDS WILL CONTINUE THRU THIS EVENING WITH SPEEDS LIKELY AT OR ABOVE 10 KTS. WINDS WILL BEGIN TO TURN SOUTHEAST LATER THIS EVENING AND OVERNIGHT...THEN MORE SOUTH/ SOUTHWEST THURSDAY MORNING AS A WARM FRONT LIFTS THROUGH THE TERMINALS. WHEN THIS OCCURS...EXPECT RAPID IMPROVEMENT THROUGH MVFR CIGS AND LIKELY TO PREVAILING VFR CIGS...OUTSIDE PRECIP... INTO THURSDAY MORNING. CMS //ORD AND MDW CONFIDENCE...UPDATED 12Z... * MEDIUM FOR CIGS/VIS THRU THE PERIOD. * MEDIUM FOR WINDS THRU PERIOD. * MEDIUM FOR THUNDERSTORMS TONIGHT...LOW FOR TIMING/COVERAGE. CMS //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... * THURSDAY NIGHT...STRONG TSRA IN THE EVENING. MVFR POSSIBLE. STRONG/GUSTY SOUTHWEST WINDS BECOMING WEST. * FRIDAY...DRY/VFR. STRONG/GUSTY WEST WINDS. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY...CHANCE OF SHRA. SOUTHWEST WINDS. && .MARINE... 415 AM...A FRONTAL BOUNDARY WILL REMAIN STATIONARY JUST SOUTH OF LAKE MICHIGAN INTO THIS EVENING...THEN BEGIN TO LIFT NORTH ACROSS THE LAKE LATE TONIGHT AND THURSDAY AS A WARM FRONT AS LOW PRESSURE OVER THE PLAINS MOVES NORTHEAST TONIGHT AND THURSDAY...REACHING NORTHERN LAKE MICHIGAN BY FRIDAY MORNING. NORTHEAST WINDS WILL REMAIN IN THE 20-25KT RANGE TODAY...WITH SOME HIGHER GUSTS POSSIBLE. WINDS WILL SLOWLY DIMINISH LATE TONIGHT INTO THURSDAY MORNING...THEN AS WINDS SHIFTING SOUTHWESTERLY THURSDAY AFTERNOON AND ESPECIALLY THURSDAY EVENING...THEY WILL INCREASE TO 30 KT... SHIFTING WESTERLY THURSDAY NIGHT AFTER A COLD FRONT MOVES ACROSS THE LAKE. WINDS WILL SLOWLY DIMINISH FRIDAY AFTERNOON INTO FRIDAY EVENING...THEN BECOME LIGHT SATURDAY AS HIGH PRESSURE MOVES ACROSS THE REGION. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 5 AM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 631 AM CDT Wed Apr 8 2015 .SHORT TERM...(Today) ISSUED AT 255 AM CDT WED APR 8 2015 Latest surface analysis indicates the frontal boundary that was holding stationary over south central Illinois has shifted further north early this morning as a weak wave of low pressure was approaching west central Illinois. Scattered convection has been occurring north of the boundary over parts of east central Iowa east into our far northern counties with some nickel hail reported over the past hour around Lacon in Marshall county. We expect the scattered convection to continue into the morning hours as the wave rides east along the boundary. As the surface low shifts to our east later this morning, there may actually be a southward push to the front which is going to cause some significant problems with respect to the afternoon temperatures, especially along and north of I-74. The latest HRRR does indicate another weak wave forming to our west along the boundary early this afternoon with another complex of storms approaching west central IL. Not sure if this particular complex of storms will ride along the boundary into central Illinois or dive more southeast into the higher instability air mass south of the front. POPs will increase again this afternoon in response to this secondary wave approaching from the west. Severe potential increases this afternoon thru this evening as the boundary gets a push northward as the more significant shortwave pushes into the Plains. With the warm front expected to edge across the area this afternoon and evening, damaging wind gusts, large hail and isolated tornadoes will all be possible. The tornado threat looks tied more into areas along and just north of the warm front later this afternoon and evening. Coolest temps north of I-74 where more of an easterly flow will prevail, while south of the boundary, a blend of the MET/MAV guid seems reasonable at this point. && .LONG TERM...(Tonight through Tuesday) ISSUED AT 255 AM CDT WED APR 8 2015 Severe weather threat through Thursday evening continues to dominate the first part of the forecast. Current upper low moving into northwest Nevada will open up but remain a fairly sharp wave as it traverses the Plains on Thursday. This will help develop a surface low over western Kansas this evening, which will surge northeast and shove the frontal boundary back northward tonight. The trailing cold front will sweep from west to east across the state Thursday evening as a result. Convection to our southwest expected to expand northeastward into the mid-Mississippi Valley this evening. Latest SPC Day1 outlook extended the slight risk across the entire CWA, with an enhanced risk of severe storms from basically Springfield-Peoria westward. This enhanced risk covers the entire area on Thursday, with high-resolution models focusing on the mid-afternoon through early evening time frame as the best potential in our area. Short period of cooler and drier weather on tap for the first part of the weekend, as high pressure drifts across the Midwest. However, longer range models showing extended periods of rain chances early next week. The GFS and ECMWF have a sizable range on the position of a frontal boundary that will be setting up Sunday night and Monday, both starting off roughly along I-70 but the GFS shows a much stronger surge to the north by Tuesday. However, with both favoring some sort of precip, have kept healthy rain chances in the forecast for early next week. && .AVIATION...(For the 12Z TAFS through 12Z Thursday morning) ISSUED AT 615 AM CDT WED APR 8 2015 Frontal boundary located over the northern portion of the forecast area this morning will be the focus for periods of showers and thunderstorms along with LIFR cigs and vsbys with some of the heavy thunderstorms. Outside of the convection, and south of the frontal boundary, we will see a period of VFR cigs today with the main band of convection moving in after 21z but scattered in nature, so will continue to handle with VCTS until we see how the storms develop to our west later today. Surface winds will be quite variable in direction and speed in and near the thunderstorms today. Most of our area will see southeast winds at 10 to 15 kts today into tonight. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Smith LONG TERM...Geelhart AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
347 AM CDT WED APR 8 2015 .SHORT TERM... 347 AM CDT THROUGH THURSDAY... TODAY THROUGH FRIDAY NIGHT... MAIN FOCUS IS ON PERIODS OF CONVECTION...PARTICULARLY THIS MORNING ACROSS PART OF THE FORECAST AREAS...AND ACROSS THE ENTIRE AREA TONIGHT INTO THURSDAY. SEVERE WEATHER THREAT REMAINS OF GREAT CONCERN THURSDAY AFTERNOON AND EVENING. EARLY MORNING SURFACE ANALYSIS DEPICTS LOW PRESSURE OVER NORTHEASTERN MISSOURI...WITH AN INVERTED TROUGH EXTENDING NORTHEAST ACROSS SOUTHEAST WI/LAKE MICHIGAN. THESE FEATURES APPEAR TO BE ASSOCIATED WITH A COUPLE OF MID-LEVEL SHORT WAVE TROUGHS PROPAGATING ACROSS THE REGION IN BROAD WEST-SOUTHWESTERLY FLOW ALOFT. A CLUSTER OF THUNDERSTORMS HAD DEVELOPED ACROSS SOUTHEAST IOWA LAST EVENING IN LOW LEVEL WARM/MOIST ADVECTION MAXIMA NORTHEAST OF THE SURFACE LOW...AND CONTINUE TO PERSIST AND EXPAND SLOWLY EASTWARD ACROSS PARTS OF ILLINOIS EARLY THIS MORNING ON 30 KT 925 MB JET AHEAD OF SHORT WAVE. THESE STORMS ARE LIKELY TO CONTINUE TO DEVELOP EASTWARD ACROSS MAINLY THE SOUTHERN TWO THIRDS OR SO OF THE CWA EARLY THIS MORNING AS THE SURFACE WAVE MOVE THROUGH THE AREA. SPC MESOANALYSIS DATA INDICATES UPSTREAM AIR MASS CHARACTERIZED BY STEEP MID-LEVEL LAPSE RATES IN EXCESS OF 7.5 C/KM YIELDING 1000-1500 J/KG OF ELEVATED MUCAPE...AND ROUGHLY 40-45 KT OF EFFECTIVE DEEP LAYER BULK SHEAR. SOME OF THE STRONGER CORES MAY BE CAPABLE OF PRODUCING SOME MARGINAL HAIL THIS MORNING...THOUGH AN OVERALL WEAKENING TREND IS EXPECTED AS THE LOW LEVEL FLOW VEERS MORE WESTERLY AND DECREASES AND REDUCES LOW LEVEL MOISTURE TRANSPORT/THETA-E ADVECTION ACROSS OUR SOUTH AND SOUTHEAST COUNTIES. THIS TREND IS SUPPORTED BY HIGH-RES HRRR/RAP GUIDANCE WHICH INDICATE ACTIVITY MOVING ACROSS THE AREA THROUGH 13-14Z. MOIST/SATURATED LOW LEVEL AIR MASS HAS ALSO REDUCED VISIBILITY IN FOG OVER THE PAST SEVERAL HOURS...WITH SOME PATCHES OF DENSE FOG NOTED. MAY HAVE TO CONSIDER A HEADLINE...THOUGH MORNING SHOWERS MAY HELP RAISE VISIBILITY SOMEWHAT AND WILL CONTINUE TO MONITOR. NOT MUCH IS EXPECTED IN THE WAY OF ORGANIZED PRECIP FROM MID- MORNING INTO THIS AFTERNOON...WITH PASSAGE OF THE SHORT WAVE AND WEAKENING OF THE SURFACE WAVE ALONG THE FRONT TO OUR SOUTH. WEAK BUT PERSISTENT SOUTHWEST FLOW WILL CONTINUE ABOVE THE SHALLOW COOL BOUNDARY LAYER NORTH OF THE SURFACE FRONT...WHICH COULD PRODUCE SOME LIGHT SHOWERS OR DRIZZLE AT ABOUT ANY TIME...BUT IT APPEARS THAT THE NEXT ORGANIZED ROUND OF PRECIPITATION WILL HOLD OFF UNTIL LATER THIS AFTERNOON AND MORE SO THIS EVENING AS ANOTHER SHORT WAVE EJECTS AHEAD OF ADVANCING WEST COAST UPPER TROUGH. THUNDERSTORMS CHANCES INCREASE MARKEDLY THIS EVENING AS THIS NEXT WAVE APPROACHES THIS EVENING. SOME OF THESE ELEVATED STORMS TONIGHT MAY ALSO HAVE THE CAPABILITY OF PRODUCING LARGE HAIL WITH STEEP LAPSE RATES AND STRONG DEEP SHEAR. SHOWERS AND THUNDERSTORMS WILL VERY LIKELY BE ONGOING ACROSS THE FORECAST AREA EARLY THURSDAY MORNING...AND THE EFFECT OF THE RESULTING COLD POOL AND CLOUDINESS WILL LIKELY COMPLICATE THE EVOLUTION OF AFTERNOON POTENTIALLY SEVERE CONVECTION ACROSS THE AREA. NONETHELESS...A STRONG AND VERY DYNAMIC SHORT WAVE WILL EMANATE FROM THE CURRENT WEST COAST TROUGH RESULTING IN A DEEPENING SURFACE LOW LIFTING NORTHEAST INTO FAR NORTHERN ILLINOIS OR SOUTHERN WISCONSIN BY THURSDAY EVENING. THE COMBINATION OF THE APPROACHING VIGOROUS SHORT WAVE AND DEEPENING SURFACE LOW WILL LIFT THE CURRENT STATIONARY FRONT NORTHWARD ACROSS THE FORECAST AREA AS A WARM FRONT...WITH THE WARM SECTOR SOUTH OF THE FRONT EXPECTED TO BECOME MODERATELY UNSTABLE DURING THE AFTERNOON AS MLCAPES INCREASE TO 1500-2500 J/KG. STRONG WEST-SOUTHWEST FLOW ALOFT AND BACKED SOUTHERLY WINDS IN LOW LEVELS AHEAD OF THE LOW WILL SUPPLY COPIOUS SHEAR... SUPPORTIVE OF ORGANIZED SEVERE THUNDERSTORMS DEVELOPING DURING THE AFTERNOON AND EARLY EVENING HOURS AHEAD OF THE COLD FRONT WHICH WILL PUSH ACROSS THE CWA BY MIDNIGHT. SPC HAS MAINTAINED A LARGE ENHANCED SEVERE RISK ACROSS THE AREA FOR DAY 2/THURSDAY...WITH SOME UNCERTAINTY REMAINING PRIMARILY TO THE EFFECT OF MORNING CONVECTION ON MESOSCALE SURFACE FEATURES BY THURSDAY AFTERNOON. IF THE DYNAMIC SYSTEM IS ABLE TO OVERCOME STABILIZING INFLUENCE OF EARLIER STORMS...AND IT LIKELY WILL TO SOME DEGREE...THEN A SIGNIFICANT RISK OF DAMAGING WIND...LARGE HAIL AND TORNADOES WILL EXIST. WITH THE SURFACE LOW PASSING NEAR/NORTH OF THE AREA THURSDAY NIGHT...THE COLD FRONT WILL SWEEP EAST DURING THE EVENING AND BRING AN END TO THE SEVERE THREAT AS DRIER/COOLER AIR SPREADS IN. A STRONG NORTHERN STREAM SHORT WAVE IS PROGGED TO DIG ACROSS THE UPPER MIDWEST BEHIND THE FIRST SYSTEM ON FRIDAY...THOUGH DRY AIRMASS AND CAPPING INVERSION IN 700-600 MB LAYER NOTED IN FORECAST SOUNDINGS SHOULD PRECLUDE PRECIP IN ANY ORGANIZED FASHION. TEMPS...SHARP CONTRAST CONTINUES TODAY-TONIGHT WITH EAST- NORTHEAST FLOW NORTH OF THE STATIONARY FRONT AND MOIST/CLOUDY LOW LEVEL AIR MASS. MAY VERY WELL SEE HIGHS TODAY RANGING FROM THE MID-40S IN FAR NORTHEAST IL TO THE LOWER 70S ALONG THE LOT/ILX BORDER. WITH FRONT LIFTING NORTH THURSDAY MUCH OF THE AREA MAY BE IN THE 70S...THOUGH AGAIN MORNING CONVECTION AND RESIDUAL OUTFLOW OR CLOUDS COULD AFFECT MAX TEMPS. COOLER BUT NEAR NORMAL FRIDAY BEHIND THE COLD FRONT...BUT STILL 55-60. RATZER && .LONG TERM... 142 AM CDT SATURDAY THROUGH TUESDAY... THE FIRST FEW PERIODS OF THE EXTENDED LOOK TO BE RELATIVELY BENIGN FOR THE GREAT LAKES REGION...WITH ENSEMBLES DEMONSTRATING MINIMAL SPREAD IN THE 500MB WAVE PATTERN. WEAK TROUGHING WILL BE PIVOTING EAST ACROSS THE MID-ATLANTIC REGION SAT...WITH DIFFLUENT FLOW ARRIVING FOR THE WESTERN GREAT LAKES SAT. THE PATTERN QUICKLY FLATTENS SUN...WITH PRECIP CHANCES RETURNING FOR THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK. ENSEMBLES BEGIN TO POINT TOWARDS A TROUGH TRYING TO DIG INTO THE WESTERN CONUS MON...WHICH COULD SUPPORT A SHORTWAVE DEVELOPING ALONG THE LEE-SIDE OF THE ROCKIES. WITH THE WESTERN GULF OF MEXICO OPEN...MOISTURE SHOULD EASILY LIFT NORTH TOWARDS THE OZARKS INTO IL LATE MON INTO TUE. AS A RESULT INSTABILITY WILL LIKELY INCREASE...SO WILL CONTINUE TO MENTION THUNDER MON/TUE OF NEXT WEEK. WITH THE RELATIVELY ACTIVE FLOW...THE EXTENDED TEMPS MAY END UP SLIGHTLY ABOVE SEASONAL OR MAINLY IN THE LOW/MID 60S. PRIOR TO THE SHORTWAVE ARRIVAL MON...TEMPS MAY PUSH INTO THE UPR 60S OR NEAR 70. OVERNIGHT LOWS WILL ALSO REMAIN MILD. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * IFR/LIFR THRU THE PERIOD. * EASTERLY WINDS THRU THE PERIOD. * CHANCE OF SHOWERS OVERNIGHT THRU MID MORNING...LOW CHANCE FOR THUNDERSTORMS. * SCATTERED THUNDERSTORMS LATE EVENING INTO THURSDAY MORNING. CMS //DISCUSSION...UPDATED 06Z... COMPLEX OF THUNDERSTORMS OVER SOUTHEAST IA WILL MOVE GENERALLY EAST INTO WEST CENTRAL IL OVER THE NEXT FEW HOURS. SHORT TERM/HI RES GUIDANCE CONTINUES TO SHOW THIS ACTIVITY REMAINING MAINLY SOUTH OF THE TERMINALS AND SLOWLY WEAKENING TOWARD SUNRISE WITH ADDITIONAL DEVELOPMENT POSSIBLE ACROSS EASTERN IL AND NORTHWEST INDIANA...WITH SHOWERS OR POSSIBLE DRIZZLE FURTHER NORTH. CONFIDENCE OF TSRA AT THE TERMINALS IS LOW ENOUGH TO REMOVE MENTION OTHER THAN VICINITY AT GYY BUT TRENDS WILL NEED TO BE MONITORED EARLY THIS MORNING. SHOWER ACTIVITY COULD CONTINUE THRU THE DAY BUT GENERALLY SOUTH OF THE TERMINALS SO HAVE MAINTAINED DRY CONDITIONS INTO EARLY THIS EVENING. SHRA/TSRA ARE EXPECTED TO DEVELOP LATER THIS EVENING AND CONTINUE...PERHAPS IN A COUPLE OF WAVES...THRU THURSDAY MORNING. MEDIUM CONFIDENCE SO INCLUDED VICINITY MENTION BUT LOW CONFIDENCE FOR TIMING/DURATION. WINDS HAVE SHIFTED EAST/SOUTHEAST EARLY THIS MORNING AND SHOULD GRADUALLY TURN BACK EASTERLY OVERNIGHT AND THEN NORTHEASTERLY LATER THIS MORNING. SPEEDS ARE BIT UNCERTAIN AS GUIDANCE SUGGEST SPEEDS COULD DIMINISH UNDER 10KTS BUT NOT CONFIDENT ENOUGH TO LOWER PREVAILING SPEEDS JUST YET. WINDS WILL TURN BACK MORE EAST OR SOUTHEAST LATER THIS EVENING AND OVERNIGHT...THEN LIKELY SHIFT SOUTHERLY BY THURSDAY MORNING. IFR/LIFR CIGS ARE EXPECTED TO CONTINUE THRU THE PERIOD...PERHAPS LOWERING A BIT TOWARD SUNRISE WITH VISIBILITIES ALSO LOWERING. ITS POSSIBLE CIGS MAY LIFT TO LOWER MVFR THIS AFTERNOON BUT CONFIDENCE IS LOW. CMS //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH FOR IFR/LIFR THRU THE PERIOD. * MEDIUM FOR WINDS THRU THE PERIOD. * MEDIUM FOR SHOWERS OVERNIGHT...LOW FOR INTENSITY/DURATION. LOW FOR CHANCE OF THUNDERSTORMS TOWARD DAYBREAK. * MEDIUM FOR THUNDERSTORMS TONIGHT...LOW ON TIMING/DURATION. CMS //OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z... * THURSDAY...STRONG TSRA. MVFR. STRONG/GUSTY SOUTH/SOUTHWEST WINDS. * FRIDAY...DRY/VFR. STRONG/GUSTY WEST WINDS. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...DRY/VFR. SOUTHEAST WINDS. * MONDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS. BEACHLER && .MARINE... 340 PM CDT A PERIOD OF ACTIVE WEATHER IS UNDERWAY FOR LAKE MICHIGAN. AS OF TUESDAY AFTERNOON...A STATIONARY FRONTAL BOUNDARY LIES SOUTH OF THE LAKE WHILE STRONG HIGH PRESSURE TRACKS ACROSS EASTERN ONTARIO INTO QUEBEC. BETWEEN THE FRONTAL TROUGH TO THE SOUTH LAKE AND THE HIGH TO THE NORTH...PERSISTENT NORTHEAST TO EAST WINDS OF 25 TO 30 KT WILL COVER THE LAKE...WITH THE STRONGEST WINDS OVER THE NORTHERN PORTIONS OF THE LAKE. DEWPOINTS HAVE BEEN INCREASING OVER THE SOUTHERN PORTIONS OF THE LAKE...LEADING TO THE FORMATION OF DENSE FOG...ESPECIALLY FOR THE SOUTHERN PORTIONS OF THE LAKE. LOW PRESSURE DEVELOPING OVER THE WESTERN PLAINS WILL QUICKLY DEEPEN AND TRACK TO NORTHERN WISCONSIN...FORCING THE STATIONARY FRONT NORTH AS A WARM FRONT. WINDS WILL SHIFT FROM ELY-SELY TO SWLY FOLLOWING THE PASSAGE OF THE WARM FRONT AND TEMPORARILY SUBSIDE...BUT A STRENGTHENING GRADIENT AHEAD OF AN APPROACHING COLD FRONT WILL HELP STRENGTHEN WINDS BACK TO 25 TO 30 KT. THE COLD FRONT TRAILING SOUTHWEST FROM THE FAST-MOVING LOW WILL SWEEP ACROSS THE LAKE ON SATURDAY. HIGH PRESSURE IS EXPECTED TO SPREAD ACROSS THE LAKE ON SATURDAY...USHERING IN A PERIOD OF QUIETER WEATHER THAT SHOULD PERSIST INTO EARLY NEXT WEEK. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 5 AM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 256 AM CDT Wed Apr 8 2015 .SHORT TERM...(Today) ISSUED AT 255 AM CDT WED APR 8 2015 Latest surface analysis indicates the frontal boundary that was holding stationary over south central Illinois has shifted further north early this morning as a weak wave of low pressure was approaching west central Illinois. Scattered convection has been occurring north of the boundary over parts of east central Iowa east into our far northern counties with some nickel hail reported over the past hour around Lacon in Marshall county. We expect the scattered convection to continue into the morning hours as the wave rides east along the boundary. As the surface low shifts to our east later this morning, there may actually be a southward push to the front which is going to cause some significant problems with respect to the afternoon temperatures, especially along and north of I-74. The latest HRRR does indicate another weak wave forming to our west along the boundary early this afternoon with another complex of storms approaching west central IL. Not sure if this particular complex of storms will ride along the boundary into central Illinois or dive more southeast into the higher instability air mass south of the front. POPs will increase again this afternoon in response to this secondary wave approaching from the west. Severe potential increases this afternoon thru this evening as the boundary gets a push northward as the more significant shortwave pushes into the Plains. With the warm front expected to edge across the area this afternoon and evening, damaging wind gusts, large hail and isolated tornadoes will all be possible. The tornado threat looks tied more into areas along and just north of the warm front later this afternoon and evening. Coolest temps north of I-74 where more of an easterly flow will prevail, while south of the boundary, a blend of the MET/MAV guid seems reasonable at this point. && .LONG TERM...(Tonight through Tuesday) ISSUED AT 255 AM CDT WED APR 8 2015 Severe weather threat through Thursday evening continues to dominate the first part of the forecast. Current upper low moving into northwest Nevada will open up but remain a fairly sharp wave as it traverses the Plains on Thursday. This will help develop a surface low over western Kansas this evening, which will surge northeast and shove the frontal boundary back northward tonight. The trailing cold front will sweep from west to east across the state Thursday evening as a result. Convection to our southwest expected to expand northeastward into the mid-Mississippi Valley this evening. Latest SPC Day1 outlook extended the slight risk across the entire CWA, with an enhanced risk of severe storms from basically Springfield-Peoria westward. This enhanced risk covers the entire area on Thursday, with high-resolution models focusing on the mid-afternoon through early evening time frame as the best potential in our area. Short period of cooler and drier weather on tap for the first part of the weekend, as high pressure drifts across the Midwest. However, longer range models showing extended periods of rain chances early next week. The GFS and ECMWF have a sizable range on the position of a frontal boundary that will be setting up Sunday night and Monday, both starting off roughly along I-70 but the GFS shows a much stronger surge to the north by Tuesday. However, with both favoring some sort of precip, have kept healthy rain chances in the forecast for early next week. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) ISSUED AT 1155 PM CDT TUE APR 7 2015 A stationary front extending across central IL, just north of I-70, is forecast to drift slowly northward overnight, in response to the approach of a weakening low pressure center across Missouri. The surface low and associated 500mb shortwave will help trigger showers and storms in central IL the rest of the night. A complex of storms has already developed west of PIA in SE Iowa. The track of those storms looks to be just NW of PIA airport. However, the HRRR and NCEP 4km WRF show additional development is expected to the SE of the current storms. The new storms should affect PIA and BMI between 07z and 12z, with the southern extend possibly affecting the other terminal sites during that time. SPI/DEC/CMI sites have returned to MVFR cloud heights. PIA/BMI have remained LIFR due to 200ft cigs. BMI with vis now at 1/2sm FG. Clouds are forecast to remain status quo for much of the night, with some improvement as storms/showers pass near the terminals. The weakening low pressure is still progged to advance across central IL through early morning, dissipating before it reaches Indiana. That will keep storm chances going through around 12z. Additional storms are forecast to arrive tomorrow evening, per the 4km WRF. ESE winds of 10-15kt will continue at 8-12kt overnight, with wind directions highly dependent on how far north the stationary front drifts by morning. Winds tomorrow morning could become variable under the front, and eventually prevail from the N for PIA and southwest for BMI/SPI/DEC/CMI. The GFS and NAM have differing wind solutions, but went closer to the NAM with this set of TAFs. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Smith LONG TERM...Geelhart AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1249 AM CDT WED APR 8 2015 .UPDATE... WE HAVE MADE SOME CHANGES TO CUT BACK ON POPS A BIT OVER THE AREA TONIGHT. CONVECTIVE TRENDS THIS EVENING ASSOCIATED WITH THE UPPER LEVEL DISTURBANCE SHIFTING EASTWARD OVER NORTHEASTERN IOWA HAS LARGELY SUGGESTED THAT MOST OF THE ACTIVITY WILL REMAIN RIGHT ALONG OR JUST NORTH OF THE ILLINOIS BOARDER IN SOUTHERN WISCONSIN. AS SUCH...I HAVE CUT POPS DOWN...ESPECIALLY SOUTH OF I88. THE 00 UTC SOUNDING OUT OF KILX INDICATES SOME STEEP MID-LEVEL LAPSE RATES...BUT REMAINS CAPPED TO ELEVATED CONVECTION. THEREFORE...IN THE SHORT TERM PERIOD...THROUGH AT LEAST 06 UTC...IT APPEARS UNLIKELY THAT ANY ACTIVITY WILL DEVELOP SOUTH OF THE CURRENT ACTIVITY. HOWEVER...SOME HIRES GUIDANCE SUGGESTS THAT SOME WIDELY SCATTERED STORMS COULD DEVELOP ACROSS MY SOUTHERN CWA VERY LATE TONIGHT IN CLOSER PROXIMATE TO THE SURFACE FRONTAL ZONE...IN ASSOCIATION WITH SOME BETTER MOISTURE TRANSPORT ALONG THE LOW LEVEL JET. CONFIDENCE IS NOT THE GREATEST THAT THIS WILL MATERIALIZE HOWEVER...BUT IF ANY STORMS WERE TO DEVELOP...THE STEEP LAPSE RATES COULD SUPPORT A SMALL HAIL THREAT. IT APPEARS THE BEST CHANCES FOR THIS WILL BE AFTER 09 UTC THROUGH EARLY THURSDAY MORNING. IT ALSO APPEARS THE MAIN THREAT FOR DENSE FOG MAY REMAIN IN CLOSER PROXIMATE TO THE SURFACE FRONTAL ZONE TO OUR SOUTH...WHERE DEW POINTS ARE INTO THE 50S. THEREFORE...WHILE THERE WILL LIKELY CONTINUE TO BE FOG WITH 1 TO 3 SM VISIBILITIES OVER THE AREA...IT APPEARS LESS LIKELY FOR DENSE FOG DEVELOPMENT OVERNIGHT OVER FAR NORTHERN ILLINOIS. KJB && .SHORT TERM... 327 PM CDT THROUGH WEDNESDAY NIGHT... STRONG QUASI-STATIONARY FRONT IS DRAPED ACROSS CENTRAL ILLINOIS WITH WARM AND HUMID AIR RESIDING SOUTH OF THIS BOUNDARY WITH 60 DEGREE DEWPOINTS BUTTING UP AGAINST OUR SOUTHERN MOST CWA BORDER. TO THE NORTH OF THE BOUNDARY YOU JUMP BACK A SEASON WITH BRISK NORTHEAST WINDS AND CLOUDINESS HOLDING TEMPS IN THE 40S...EXCEPT NEAR THE LAKE WHERE TEMPS ARE STILL IN THE UPPER 30S WITH SOME MARINE FOG. WEBCAMS CONTINUE TO SUGGEST DENSEST FOG IS RIGHT AT THE SHORE...THOUGH STILL EXPECT THAT THIS FOG COULD BEGIN TO OOZE INLAND WITH TIME TONIGHT AND POSSIBLY INTO WEDNESDAY AS WELL. FRONTAL BOUNDARY WILL LIKELY WAVER AROUND A BIT THROUGH WEDNESDAY NIGHT...POTENTIALLY CREEPING NORTH INTO OUR SOUTHERN CWA AT TIMES WHICH WILL UNDOUBTEDLY CAUSE HAVOC IN MAINTAINING HOURLY TEMPERATURE GRIDS AND PLACES A HIGHER DEGREE THAN NORMAL OF UNCERTAINTY IN HIGH AND LOW TEMP FORECAST THE NEXT 36 HOURS. WATER VAPOR IMAGERY SHOWS A WELL DEFINED SHORTWAVE MOVING EASTWARD INTO THE WESTERN CORNBELT THIS AFTERNOON WITH WAA IN ADVANCE OF THIS FEATURE RESULTING IN AN INCREASE IN COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS IOWA THIS AFTERNOON. GIVEN THE FARTHER SOUTHWARD PLACEMENT OF THE FRONTAL BOUNDARY AND INSTABILITY AXIS I SUSPECT THAT THIS ACTIVITY WILL HAVE A TENDENCY TO PROPAGATE/DEVELOP SOUTHWARD WITH AN INCREASE IN COVERAGE AND INTENSITY THIS EVENING WITH THE NOCTURNAL STRENGTHENING OF THE LOW LEVEL JET. PWATS OF AROUND 200 PERCENT OF NORMAL SUGGEST THAT ANY THUNDERSTORMS THAT DO DEVELOP COULD BE VERY EFFICIENT RAIN PRODUCERS. EXTRAPOLATION HAS THAT SHORTWAVE MOVING EAST OF OUR AREA BY 06Z SUGGESTING MOST ORGANIZED PRECIP SHOULD SHIFT EAST WITH IT THOUGH CONTINUED WAA OVER TOP SHALLOW COLD AIR MASS DOES RAISE AT LEAST THE POTENTIAL OF CONTINUED CONVECTIVE DEVELOPMENT INTO THE OVERNIGHT HOURS. CANNOT RULE OUT SOME LINGERING MORE SHOWERS...MAINLY EASTERN CWA...BUT OVERALL WEDNESDAY LOOKS TO BE DRY OTHER THAN SOME POSSIBLE DRIZZLE WITH THE THICKER FOG NEAR THE LAKE. NEXT SHORTWAVE AND ASSOCIATED RAMPING OF LOW LEVEL JET/WAA LOOKS TO BE WEDNESDAY NIGHT WHEN ONCE AGAIN LOCALLY HEAVY RAINFALL WILL BE A DISTINCT POSSIBILITY. ANTECEDENT CONDITIONS ARE GENERALLY PRETTY DRY...SO OTHER THAN URBAN AREAS OR REMOTE THREAT OF EXTREME RAINFALL TOTALS THINK THE FLASH FLOOD CONCERNS LOOK NOT TOO IMPRESSIVE AT THIS TIME. IZZI && .LONG TERM... 327 PM CDT THURSDAY NIGHT THROUGH TUESDAY... PRIMARY TROUGH IS STILL PROGGED TO MOVE QUICKLY EASTWARD AND INTO THE MIDWEST BY THURSDAY AFTERNOON. GUIDANCE VARIES SOME WITH RESPECT TO TIMING/INTENSITY OF THIS SYSTEM WITH 12Z ECMWF ON THE FASTER/WEAKER END OF THE GUIDANCE SPECTRUM AND THE NAM/GEM ON THE SLOWER DEEPER END OF THE SPECTRUM. OFTEN TIMES THE SLOWER GUIDANCE ENDS UP VERIFYING BETTER WITH THESE STRONGER SYSTEMS...SO TRENDED THE GRIDS TOWARD THE NAM/GEM SOLUTION. THE GFS SUPPORTS THE IDEA OF STRONGER SYSTEM BUT SUSPECT IT IS A BIT TOO FAST. SYNOPTICALLY SPEAKING THE LARGE SCALE PATTERN AND EVOLUTION OF THIS CYCLONE CONTINUE TO RAISE RED FLAGS FOR THE POTENTIAL OF A SIGNIFICANT SEVERE WEATHER EPISODE IN THE REGION THURSDAY AFTERNOON AND EVENING. THE KINEMATIC FIELDS ARE EXTREMELY IMPRESSIVE WITH 90- 100KT UPPER LEVEL JET NOSING INTO THE REGION IN THE AFTERNOON WITH 40KT+ LOW LEVEL JET RESULTING IN VERY FAVORABLE DEEP LAYER SHEAR PROFILE FOR SEVERE WEATHER. THE MAGNITUDE OF LOW LEVEL SHEAR WHICH WILL PLAY A ROLE IN THE MAGNITUDE OF A TORNADO THREAT VARIES DEPENDING ON THE MODEL. THE DEEPER SOLUTIONS HAVE A MORE BACKED SURFACE FLOW AND LARGER LOW LEVEL HODOGRAPHS AND WOULD BE MUCH MORE WORRISOME REGARDING TORNADO THREAT. THE LATEST MODEL RUNS THIS MORNING ALSO SUGGEST AN UNUSUALLY IMPRESSIVE PLUME OF STEEP MID LEVEL LAPSE RATES FOR SO FAR EASTWARD BECOME JUXTAPOSED OVER TOP A WARM AND HUMID AIR MASS WITH SURFACE DEWPOINTS LIKELY IN THE 60S WITHIN THE WARM SECTOR. GIVEN THE PROGGED INTENSITY OF THE SYSTEM SUSPECT THAT EVEN MORNING CONVECTION WILL NOT BE ENOUGH TO PREVENT THE WARM FRONT FROM BLASTING NORTH AND PLACING ENTIRE CWA IN THE HUMID/UNSTABLE WARM SECTOR BY AFTERNOON. OBVIOUSLY THERE ARE A TON OF MESOSCALE DETAILS THAT CANNOT BE RESOLVED AT THIS DISTANCE...INCLUDING STORM MODE AND COVERAGE. THERE IS A LOT THAT CAN CHANGE BETWEEN NOW AND THURSDAY SO A SIGNIFICANT SEVERE WEATHER EVENT IS FAR FROM A SURE THING...BUT GIVEN THE TRENDS IN MODEL GUIDANCE AND SYNOPTIC PATTERN THERE IS DEFINITELY REASON FOR CONCERN ABOUT THE SEVERE WEATHER AND TORNADO POTENTIAL THURSDAY AFTERNOON AND EVENING. COOLER/DRIER PACIFIC AIR WILL FILTER INTO THE REGION FRIDAY ON BRISK WESTERLY WINDS...FOLLOWED BY A MODERATING TREND HEADING INTO THE WEEKEND IN ADVANCE OF THE NEXT SYSTEM WHICH LOOKS TO ARRIVE LATE SUNDAY OR MONDAY WITH OUR NEXT SHOT OF SHOWERS AND THUNDERSTORMS. IZZI && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * IFR/LIFR THRU THE PERIOD. * EASTERLY WINDS THRU THE PERIOD. * CHANCE OF SHOWERS OVERNIGHT THRU MID MORNING...LOW CHANCE FOR THUNDERSTORMS. * SCATTERED THUNDERSTORMS LATE EVENING INTO THURSDAY MORNING. CMS //DISCUSSION...UPDATED 06Z... COMPLEX OF THUNDERSTORMS OVER SOUTHEAST IA WILL MOVE GENERALLY EAST INTO WEST CENTRAL IL OVER THE NEXT FEW HOURS. SHORT TERM/HI RES GUIDANCE CONTINUES TO SHOW THIS ACTIVITY REMAINING MAINLY SOUTH OF THE TERMINALS AND SLOWLY WEAKENING TOWARD SUNRISE WITH ADDITIONAL DEVELOPMENT POSSIBLE ACROSS EASTERN IL AND NORTHWEST INDIANA...WITH SHOWERS OR POSSIBLE DRIZZLE FURTHER NORTH. CONFIDENCE OF TSRA AT THE TERMINALS IS LOW ENOUGH TO REMOVE MENTION OTHER THAN VICINITY AT GYY BUT TRENDS WILL NEED TO BE MONITORED EARLY THIS MORNING. SHOWER ACTIVITY COULD CONTINUE THRU THE DAY BUT GENERALLY SOUTH OF THE TERMINALS SO HAVE MAINTAINED DRY CONDITIONS INTO EARLY THIS EVENING. SHRA/TSRA ARE EXPECTED TO DEVELOP LATER THIS EVENING AND CONTINUE...PERHAPS IN A COUPLE OF WAVES...THRU THURSDAY MORNING. MEDIUM CONFIDENCE SO INCLUDED VICINITY MENTION BUT LOW CONFIDENCE FOR TIMING/DURATION. WINDS HAVE SHIFTED EAST/SOUTHEAST EARLY THIS MORNING AND SHOULD GRADUALLY TURN BACK EASTERLY OVERNIGHT AND THEN NORTHEASTERLY LATER THIS MORNING. SPEEDS ARE BIT UNCERTAIN AS GUIDANCE SUGGEST SPEEDS COULD DIMINISH UNDER 10KTS BUT NOT CONFIDENT ENOUGH TO LOWER PREVAILING SPEEDS JUST YET. WINDS WILL TURN BACK MORE EAST OR SOUTHEAST LATER THIS EVENING AND OVERNIGHT...THEN LIKELY SHIFT SOUTHERLY BY THURSDAY MORNING. IFR/LIFR CIGS ARE EXPECTED TO CONTINUE THRU THE PERIOD...PERHAPS LOWERING A BIT TOWARD SUNRISE WITH VISIBILITIES ALSO LOWERING. ITS POSSIBLE CIGS MAY LIFT TO LOWER MVFR THIS AFTERNOON BUT CONFIDENCE IS LOW. CMS //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH FOR IFR/LIFR THRU THE PERIOD. * MEDIUM FOR WINDS THRU THE PERIOD. * MEDIUM FOR SHOWERS OVERNIGHT...LOW FOR INTENSITY/DURATION. LOW FOR CHANCE OF THUNDERSTORMS TOWARD DAYBREAK. * MEDIUM FOR THUNDERSTORMS TONIGHT...LOW ON TIMING/DURATION. CMS //OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z... * THURSDAY...STRONG TSRA. MVFR. STRONG/GUSTY SOUTH/SOUTHWEST WINDS. * FRIDAY...DRY/VFR. STRONG/GUSTY WEST WINDS. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...DRY/VFR. SOUTHEAST WINDS. * MONDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS. BEACHLER && .MARINE... 340 PM CDT A PERIOD OF ACTIVE WEATHER IS UNDERWAY FOR LAKE MICHIGAN. AS OF TUESDAY AFTERNOON...A STATIONARY FRONTAL BOUNDARY LIES SOUTH OF THE LAKE WHILE STRONG HIGH PRESSURE TRACKS ACROSS EASTERN ONTARIO INTO QUEBEC. BETWEEN THE FRONTAL TROUGH TO THE SOUTH LAKE AND THE HIGH TO THE NORTH...PERSISTENT NORTHEAST TO EAST WINDS OF 25 TO 30 KT WILL COVER THE LAKE...WITH THE STRONGEST WINDS OVER THE NORTHERN PORTIONS OF THE LAKE. DEWPOINTS HAVE BEEN INCREASING OVER THE SOUTHERN PORTIONS OF THE LAKE...LEADING TO THE FORMATION OF DENSE FOG...ESPECIALLY FOR THE SOUTHERN PORTIONS OF THE LAKE. LOW PRESSURE DEVELOPING OVER THE WESTERN PLAINS WILL QUICKLY DEEPEN AND TRACK TO NORTHERN WISCONSIN...FORCING THE STATIONARY FRONT NORTH AS A WARM FRONT. WINDS WILL SHIFT FROM ELY-SELY TO SWLY FOLLOWING THE PASSAGE OF THE WARM FRONT AND TEMPORARILY SUBSIDE...BUT A STRENGTHENING GRADIENT AHEAD OF AN APPROACHING COLD FRONT WILL HELP STRENGTHEN WINDS BACK TO 25 TO 30 KT. THE COLD FRONT TRAILING SOUTHWEST FROM THE FAST-MOVING LOW WILL SWEEP ACROSS THE LAKE ON SATURDAY. HIGH PRESSURE IS EXPECTED TO SPREAD ACROSS THE LAKE ON SATURDAY...USHERING IN A PERIOD OF QUIETER WEATHER THAT SHOULD PERSIST INTO EARLY NEXT WEEK. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 5 AM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1159 PM CDT Tue Apr 7 2015 .UPDATE... ISSUED AT 902 PM CDT TUE APR 7 2015 The stationary front is not making much progress northward yet this evening. The latest sfc analysis shows the front still lingering between I-72 and I-70 at 02z/9pm. Minor clearing has developed toward SPI and Jacksonville, but the last hour clouds have begun to re-develop in response to an inversion and trapped low level moisture. Have continued with including fog along and north of I-74 the rest of the night, with some dense fog ongoing around BMI. Low pressure is expected to advance along the front tonight, helping to give it a northward push. Showers and storms should accompany the arrival of the low, with the help of a 500mb shortwave and increasing instability. Storms will increase in coverage from west to east after 06z/1am. The storms will be elevated, so hail will be more of a concern than very strong wind gusts. No severe storms are anticipated with the wave of storms later tonight, as the overall system dynamics will be weakening with time as it moves across Illinois. Forecast updates included: delaying the onset of precip for a few more hours, diminished PoPs NW of the IL river late tonight, adjusted hourly temps to try to match expected frontal boundary movement northward. Updated forecast info is already available. && .SHORT TERM...(Tonight) ISSUED AT 301 PM CDT TUE APR 7 2015 A quasi stationary front remains over central IL between I-70 and I-72. The frontal boundary should start to slowly push back northward across central IL later this evening and overnight as 1007 mb low pressure over northeast KS tracks into central IL by Wed morning. An MCS was bringing showers and a few thunderstorms to southeast IL at mid afternoon while the strong to severe storms with heavy rains were south of highway 50 and approaching the Ohio river as they tracked eastward. pushes southward, wavering over central Illinois, southerly flow will continue to bring in more boundary layer moisture. Scattered showers and thunderstorms will develop during tonight along this boundary over central IL as low pressure approaches and frontal boundary starts to lift back north with ample moisture. Some fog still lingering north of I-72 and added some fog to areas north of this boundary tonight especially from I-74 northward. Lows tonight mostly in the upper 50s and lower 60s, except cooler low to mid 50s from Galesburg to Peoria and Bloomington northward which stays north of the boundary much of the night. && .LONG TERM...(Wednesday through Tuesday) ISSUED AT 301 PM CDT TUE APR 7 2015 Not too much has changed in the large scale pattern/expected weather over the next few days. However, things will continue to be tricky with respect to the convective details and temperatures due to the wobbling surface boundary and model disagreement in the ultimate strength of the main low/frontal passage for Thursday. The frontal boundary that currently lies west-east across the Midwest will not move appreciably through Wednesday. Nearly continuous WAA/isentropic ascent is progged through a deep layer across the area until the main system arrives heading into Wednesday night. Until the system approaches, forecast soundings (and 12Z KILX sounding for that matter) suggest a persistent elevated mixed layer, but also a fairly stout low level capping inversion. Moisture continues to be lacking within the EML, so PoPs will stay on the lower side for most of Wednesday. The remnants of the Pacific Coast will help force the frontal boundary back northward Wednesday night as it pushes across the Plains. This will spread more widespread showers/storms across the area as early as late Wednesday afternoon into Wednesday night. There will be ample shear for some of the storms to be on the stronger side, but they should be elevated in nature for the most part and most apt to be hail producers. The main low/cold front are still on tap to cross the region Thursday into Thursday evening, although there are still considerable timing/strength differences. The ECMWF continues to be much weaker and (not surprisingly) several hours slower than the building model consensus. Do not have a compelling reason to disregard the ECMWF, but have leaned more toward the larger model consensus. This scenario supports strong/severe storms across the forecast area along/ahead of the front on Thursday, mainly during the afternoon. Instability and shear profiles are both expected to be more than respectable, with CAPE values averaging 1500-2500 j/kg, and bulk shear values from 35-45 kts. The cold front is expected to clear most of the area by late Thursday evening, ushering in quieter weather until Sunday. Then, another storm system will bring renewed shower/storm chances to start out next week. However, model spread and run-to-run consistency in the details continues to be poor at best. This is resulting in an extended period of PoPs from what should only be one system passage. Hopefully a better agreed upon solution develops soon. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) ISSUED AT 1155 PM CDT TUE APR 7 2015 A stationary front extending across central IL, just north of I-70, is forecast to drift slowly northward overnight, in response to the approach of a weakening low pressure center across Missouri. The surface low and associated 500mb shortwave will help trigger showers and storms in central IL the rest of the night. A complex of storms has already developed west of PIA in SE Iowa. The track of those storms looks to be just NW of PIA airport. However, the HRRR and NCEP 4km WRF show additional development is expected to the SE of the current storms. The new storms should affect PIA and BMI between 07z and 12z, with the southern extend possibly affecting the other terminal sites during that time. SPI/DEC/CMI sites have returned to MVFR cloud heights. PIA/BMI have remained LIFR due to 200ft cigs. BMI with vis now at 1/2sm FG. Clouds are forecast to remain status quo for much of the night, with some improvement as storms/showers pass near the terminals. The weakening low pressure is still progged to advance across central IL through early morning, dissipating before it reaches Indiana. That will keep storm chances going through around 12z. Additional storms are forecast to arrive tomorrow evening, per the 4km wrf. ESE winds of 10-15kt will continue at 8-12kt overnight, with wind directions highly dependent on how far north the stationary front drifts by morning. Winds tomorrow morning could become variable under the front, and eventually prevail from the N for PIA and southwest for BMI/SPI/DEC/CMI. The GFS and NAM have differing wind solutions, but went closer to the NAM with this set of TAFs. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Shimon SHORT TERM...07 LONG TERM...Bak AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
817 PM EDT THU APR 9 2015 .SYNOPSIS... ISSUED AT 816 PM EDT THU APR 9 2015 SOME STORMS THIS EVENING COULD BECOME STRONG TO SEVERE AS A STRONG COLD FRONT SWEEPS THE REGION. LOW TEMPERATURES OVERNIGHT WILL PRIMARILY BE IN THE 40S. HIGHS ON FRIDAY WILL BE COOLER...IN THE MIDDLE 50S TO AROUND 60. && .UPDATE/AVIATION... ISSUED AT 815 PM EDT THU APR 9 2015 18Z RAOB OUT OF KILX INDICATES CURRENT CONV PROB ATTM W/CAPPING INVERSION ARND H85 AND NO DOUBT EXACERBATED BY SUBSIDENCE ASSOCD/W SW TROUGH OVERHEAD. EXTENT/DURATION OF POPS THIS EVENING AHD OF STG CDFNT SWEEPING EWD OUT OF WRN IL PROBLEMATIC IN LIGHT OF LIMITED UPSTREAM DVLPMNT SO FAR AND LACK OF LARGER SCALE ORGANIZATION. LATEST NR TERM AND 18Z GUIDANCE TEPID AT BEST AND SUGGESTIVE OF TEMPERING PRIOR CAT MENTION. REGARDLESS COOLING ALOFT SPREAD EWD OVERTOP FNTL ZONE IN TANDEM W/RAMPING LLJ SHLD PREDICATE MORE ERSTWHILE DVLPMNT THOUGH MID EVENING AS CONVN SLIDES EWD INTO WRN ZONES. GENERAL VFR CONDS XPCD THIS PD ALTHOUGH TRANSIENT PD OF MVFR CIGS PSBL ASSUMING SHRA/VCTS HOLD ALG FNTL BNDRY. BIGGER ISSUE WILL BE POST FNTL GRADIENT WINDS W/LL CAA SURGE AND INCOMING MID LVL DRY SLOT. XPC A PD OF SFC GUSTS OF 35-40 KTS IN 09-15Z WINDOW. && .SHORT TERM...(THIS EVENING AND TONIGHT) ISSUED AT 324 PM EDT THU APR 9 2015 MULTIPLE CONVECTIVELY-ENHANCED SHORTWAVES CONTINUE TO RIPPLE THROUGH THE REGION IN SOUTHWEST FLOW AHEAD OF MAIN TROUGH AXIS STILL WELL TO OUR WEST. THIS HAS LED TO A MUDDLED MESOSCALE ENVIRONMENT WITH MULTIPLE ROUNDS OF WEAK/ELEVATED CONVECTION SO FAR TODAY. DIURNAL DESTABILIZATION HAS BEEN SLOW GIVEN ABUNDANT RAIN AND STRATUS. STARTED TO SEE SOME BREAKS IN THE CLOUDS DURING THE LAST COUPLE HOURS BUT STILL A LOT OF CONVECTIVE DEBRIS TO INHIBIT SURFACE DIABATIC HEATING. LATEST RAP/SPC MESOANALYSIS SHOWS BETTER SURFACE BASED INSTABILITY JUST NOW STARTING TO NOSE INTO OUR SOUTHWESTERN CWA AS WARM FRONT IS PUSHED NORTHWARD BY STRENGTHENING LOW LEVEL GRADIENT AHEAD OF APPROACHING LOW BUT RAP SOUNDINGS STILL SHOW A SUBTLE 700-800MB INVERSION OVER MUCH OF OUR AREA THROUGH THE LATE AFTERNOON. TWO FEATURES TO WATCH FOR SEVERE WEATHER THREAT THIS EVENING...ONE IS A SUBTLE PREFRONTAL TROUGH CURRENTLY PUSHING THROUGH NORTH-CENTRAL ILLINOIS AND SECOND IS THE ACTUAL COLD FRONT ITSELF...STILL IN CENTRAL MISSOURI. FORCING IS WEAK WITH THE FIRST WAVE BUT APPEARS TO BE ENOUGH SURFACE HEATING TO GENERATE AROUND 1000 J/KG OF MLCAPE OVER ILLINOIS. THERE IS HOWEVER A LOCAL MINIMUM OF INSTABILITY SEEN ON RAP/SPC MESOANALYSIS OVER WESTERN INDIANA. RAP SUGGESTS INSTABILITY IN THIS AREA WILL FILL IN OVER THE NEXT FEW HOURS AND IF THE CLUSTER OF STORMS OVER CENTRAL ILLINOIS CAN LATCH ONTO THAT...IT WILL BE CAPABLE OF PRODUCING SEVERE WEATHER IN OUR AREA LATER THIS AFTERNOON. CONFIDENCE IN THIS HAPPENING IS LOW THOUGH...GIVEN NORTHWARD DISPLACEMENT OF STORMS CURRENTLY ON RADAR AND RELATIVELY DIFFUSE FORCING. STORMS MAY CLIP OUR NORTHWEST COUNTIES BUT DIFFICULT TO SAY HOW MUCH INSTABILITY WILL BE LEFT BY THAT POINT. SPC HAS ISSUED A TORNADO WATCH RIGHT UP TO OUR WESTERN BORDER. WILL CONTINUE TO MONITOR CLUSTER OF STORMS UPSTREAM DURING THE NEXT FEW HOURS TO SEE IF A LOCAL EXTENSION MAY BE NECESSARY BUT FOR NOW THREAT APPEARS LOW. POTENTIAL THREAT WITH THIS FEATURE WILL FALL IN THE 22-00Z TIMEFRAME WITH THE MAIN HAZARD BEING DAMAGING WINDS. SECOND FEATURE TO WATCH IS THE ACTUAL COLD FRONT. THIS FEATURE WILL NOT ARRIVE UNTIL 03-04Z TONIGHT AND BY THEN WE LOSE ANY SURFACE BASED INSTABILITY. MIDLEVEL LAPSE RATES ARE MODEST...AROUND 7 C/KM...BUT NOT QUITE HIGH ENOUGH TO SUPPORT A WIDESPREAD SEVERE WEATHER THREAT. SOME DAMAGING WINDS ARE CERTAINLY POSSIBLE GIVEN VERY STRONG LLJ WITH 850MB WINDS OVER 50 KTS BUT WILL BE CONTINGENT UPON GETTING A SUSTAINED UPDRAFT AND ADEQUATE PRECIP LOADING. THAT IS QUESTIONABLE AT THIS POINT. THREAT IS CERTAINLY THERE BUT IS CONDITIONAL ON HOW MUCH INSTABILITY IS LEFT BY THE TIME IT REACHES US. WILL CONTINUE TO MONITOR UPSTREAM TRENDS CLOSELY THROUGH THE LATE AFTERNOON AND EVENING TO UPDATE THE FORECAST AS NECESSARY. UPDATED GRIDS/ZFP WILL BE OUT SHORTLY. && .LONG TERM...(FRIDAY THROUGH THURSDAY) ISSUED AT 324 PM EDT THU APR 9 2015 PRIMARY FOCUS FOR THE LONG TERM WILL BE HIGH WINDS ON FRIDAY... THE SFC LOW PRESSURE SYSTEM RESPONSIBLE FOR THE ACTIVE WEATHER TODAY WILL HAVE MADE ITS WAY INTO EASTERN UPPER MICHIGAN BY FRIDAY MORNING. THIS PUTS THE CWA LARGELY IN THE DRY SLOT AND IN THE REGION OF CAA. ALOFT...A CLOSED 500MB LOW LIFTS FROM UPPER MICHIGAN FRIDAY MORNING TO JUST SOUTH OF JAMES BAY BY FRIDAY NIGHT. WITH A STRONG RIDGE ANCHORED OVER THE ATLANTIC/NEW ENGLAND STATES...A 100 KT 500MB JET DEVELOPS OVER THE CWA AND REMAINS THROUGH AT LEAST THE EARLY AFTERNOON. LOOKING AT MODEL SOUNDINGS...IT APPEARS WE WILL BE MIXING TO NEAR 900MB EARLIER IN THE DAY...THEN UP AS HIGH AS 700-750MB BY MID AFTERNOON. THINKING GUSTS WILL BE HIGHEST IN THE EARLY AFTERNOON THEN TAPER OFF WEST TO EAST AS THE UPPER LEVEL WIND MAXIMUM AND SFC PRESSURE RISE/FALL COUPLET MOVES NORTHEASTWARD. THINKING GUSTS TO 35-45 MPH ARE LIKELY GIVEN MIXING POTENTIAL TOMORROW...BUT WILL HOLD OFF ON ISSUING ANY WIND ADVISORIES FOR NOW...AS WE ARE RIGHT BELOW CRITERIA AND DO NOT WANT TO DETRACT PUBLIC ATTENTION AWAY FROM THE THREAT OF SEVERE WEATHER THIS EVENING/OVERNIGHT. KEPT THE GOING HEADLINE FOR THE GALE WARNING UNTIL 15Z...AS CONDITIONS ARE MORE STABLE OVER THE LAKE. OTHERWISE...SHORTWAVE/PV ANOMALY ROTATING AROUND THE EXITING LOW PRESSURE MAY BRING ADDITIONAL LL MOISTURE FORCING FOR RAIN SHOWERS FRIDAY AFTERNOON/EVENING...MAINLY IN THE NORTHERN PORTIONS OF OUR CWA. MODELS WERE IN GREAT DISAGREEMENT AS TO THE STRENGTH OF THE WAVE...SO FOR NOW KEPT JUST SLIGHT CHANCE POPS/RAIN SHOWERS FOR NOW. HIGHS WILL RANGE FROM THE MID-UPPER 50S TO LOW 60S. SATURDAY INTO SUNDAY AFTERNOON WILL BE RELATIVELY QUIET...WITH HIGH PRESSURE SETTLING IN OVERHEAD. HIGH TEMPERATURES WILL BE COOL...WITH HIGHS AGAIN STRUGGLING TO REACH ABOVE THE LOW 60S. FOR THE EXTENDED PERIOD...500MB FLOW IS SOMEWHAT SPLIT BY SUNDAY NIGHT...WITH A DEEPENING TROUGH MOVING ACROSS NORTHERN ONTARIO AND UPPER MI/NORTHERN LOWER MI THROUGH MONDAY NIGHT...THEN A DEVELOPING CLOSED LOW IN THE SOUTHWESTERN U.S. TAKES SHAPE MONDAY NIGHT INTO TUE AS A RIDGE BUILDS OVER OUR CWA AND THE SOUTHEASTERN STATES. THE LOW DEEPENS AND MOVES NORTHEASTWARD TUE NIGHT INTO THE NORTH-CENTRAL PLAINS BEFORE PHASING INTO THE NORTHERN BRANCH WED. FOR OUR CWA...MODELS ARE IN GENERAL AGREEMENT WITH RESPECT TO THE COLD FRONT ASSOCIATED WITH THE NORTHERN STREAM SYSTEM IN ONTARIO/UPPER MI. BOTH THE ECMWF/GFS BRING THE FRONT ACROSS OUR AREA SUNDAY NIGHT INTO MONDAY...THOUGH THEY DIFFER WITH RESPECT TO EXACT TIMING AND STRENGTH. AS USUAL...THE GFS IS FASTER AND SLIGHTLY DEEPER WITH THE UPPER LEVEL TROUGH MOVING THROUGH...AND THUS THE FRONT IS MORE ORGANIZED. THE ECMWF SHOWS A WEAKER UL TROUGH AND CORRESPONDING SFC SYSTEM/COLD FRONT. KEPT CONSENSUS POPS FOR NOW...WHICH DID A DECENT JOB SHOWING THE OVERALL TREND. TUESDAY LOOKS TO REMAIN LARGELY QUIET...WITH SMALL RIDGE BUILDING OVER THE AREA FOR THE FIRST PART OF THE DAY. SLIGHT CHANCE FOR RAIN SHOWERS BY LATE AFTERNOON WITH NEXT APPROACHING SYSTEM. OF COURSE...THE PHASING SYSTEMS/STREAMS ARE A COMPLETE MESS IN THE MODEL WORLD...WITH A WHOLE HOST OF SOLUTIONS THAT COULD PLAY OUT TUESDAY NIGHT INTO THURSDAY. JUST KEPT THE CONSENSUS POPS AND OUR FORECASTED THUNDER AS THERE IS TOO MUCH DISAGREEMENT TO MAKE ANY REAL IMPROVEMENTS. GOOD NEWS IS...TEMPS WARM INTO THE UPPER 60S AND LOW 70S FOR MUCH OF THIS TIME PERIOD. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...GALE WARNING FROM 11 PM THIS EVENING TO 11 AM EDT FRIDAY FOR LMZ043-046. && $$ UPDATE...T SYNOPSIS...MURPHY SHORT TERM...AGD LONG TERM...MCD AVIATION...T/MURPHY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION...CORRECTED
NWS NORTHERN INDIANA
400 PM EDT WED APR 8 2015 .SYNOPSIS... ISSUED AT 1003 AM EDT WED APR 8 2015 SEVERAL PERIODS OF RAIN WILL BE POSSIBLE DURING THE NEXT COUPLE OF DAYS. A STATIONARY FRONT OVER CENTRAL PORTIONS OF INDIANA AND OHIO IS EXPECTED TO LIFT SLOWLY NORTH INTO MICHIGAN TONIGHT. SCATTERED THUNDERSTORMS ARE POSSIBLE NEAR THE FRONT TODAY WITH SHOWERS AND THUNDERSTORMS LIKELY BECOMING NUMEROUS TONIGHT. A COLD FRONT WILL APPROACH THE AREA ON THURSDAY LIKELY CAUSING ANOTHER ROUND OF THUNDERSTORMS. HIGHS TODAY ARE EXPECTED TO RANGE FROM THE MID 50S NORTH OF THE FRONT IN SOUTHERN MICHIGAN TO THE LOW 70S SOUTH OF THE FRONT SOUTH OF US 30. LOWS TONIGHT WILL BE IN THE 50S. && .SHORT TERM...(THIS EVENING AND TONIGHT) ISSUED AT 400 PM EDT WED APR 8 2015 BRIEF LULL IN PRECIP AND INCREASED LOW LEVEL MIXING IS CURRENTLY IN PLACE ACROSS NORTHERN INDIANA THANKS TO MIDLEVEL SHORTWAVE RIDGING/AVA IN THE WAKE OF THIS MORNING`S CONVECTION. MCS THAT MOVED THROUGH CENTRAL INDIANA EARLIER TODAY SEEMS TO HAVE LEFT MOST OF OUR AREA FAIRLY STABLE/CAPPED PER LATEST SPC/RAP MESOANALYSIS. FORECAST SOUNDINGS SHOW A DECENT INVERSION AROUND 800MB...EVEN IN AREAS THAT HAVE MANAGED TO MIX OUT. NAM12 TRIES TO WEAKEN THIS CAPPING INVERSION IN OUR AREA LATER THIS AFTERNOON BUT RAP AND GFS KEEP IT IN PLACE FOR MUCH OF THE EVENING...AT LEAST OUTSIDE OF THE FAR SOUTH. BASED ON THE LATEST RADAR...SATELLITE...AND SURFACE OBSERVATIONAL TRENDS...PREFER TO LEAN TOWARD THE RAP IDEA OF KEEPING OUR CWA MAINLY CAPPED WITH CONVECTION TIED TO BETTER INSTABILITY JUST TO OUR SOUTH. SYNOPTIC FORCING IS PRETTY MUDDLED AT THIS POINT BUT THERE ARE SOME HINTS OF MODEST 300K ISENTROPIC ASCENT JUST TO OUR SOUTH AS WELL. SPC HAS ISSUED A SEVERE THUNDERSTORM WATCH UP TO OUR SOUTHWEST BORDER AND THIS SEEMS REASONABLE. CURRENTLY WATCHING A CLUSTER OF STORMS OVER EASTERN ILLINOIS THAT COULD SCRAPE OUR FAR SOUTHERN COUNTIES. IF THIS ACTIVITY DOES CLIP OUR AREA...IT COULD VERY WELL PRODUCE SEVERE WEATHER GIVEN DEEP LAYER SHEAR OVER 40 KTS AND MLCAPE VALUES OVER 2000 J/KG DUE TO MIDLEVEL LAPSE RATES AROUND 8 C/KM. BETTER CHANCES FOR MORE WIDESPREAD RAIN AND THUNDERSTORMS EXPECTED LATE OVERNIGHT. ANOTHER WEAK/EMBEDDED SHORTWAVE WILL EJECT NORTHEAST ALONG WITH NOCTURNAL STRENGTHENING OF THE LOW LEVEL JET. ANOTHER ROUND OF INCREASED MOISTURE FLUX CONVERGENCE AND ISENTROPIC ASCENT IN A REGION OF MODERATE ELEVATED INSTABILITY MAY SUPPORT EXPANDING CONVECTION LATE TONIGHT. EXACT TIMING AND LOCATION IS DIFFICULT TO PINPOINT AT THIS STAGE WITH A VARIETY OF SOLUTIONS BEING OFFERED BY LATEST HI-RES GUIDANCE. AM A LITTLE UNEASY WITH INHERITED CATEGORICAL POPS GIVEN DRY SOLUTIONS BEING OFFERED BY SOME HI-RES GUIDANCE SUCH AS THE 4KM SPC WRF-NMM. LOWERED POPS EARLIER IN THE PERIOD BUT DID KEEP SOME CATEGORICAL POPS IN THE 09-12Z PERIOD OUT OF RESPECT FOR THE INCREASING WARM/MOIST AIR ADVECTION AND MODEL DEPICTIONS OF WEAK CVA FORCING. OTHER ASPECT THAT DEMANDS SOME ATTENTION IS THE POTENTIAL FOR HEAVY RAIN/FLOODING WITH MULTIPLE ROUNDS OF CONVECTION THIS WEEK. PW VALUES DO SURGE TO AROUND 1.5 INCHES LATE TONIGHT (AND INTO TOMORROW) AND HEAVY RAIN WILL CERTAINLY BE POSSIBLE WHEN/WHERE CONVECTION DOES OCCUR. HOWEVER...POTENTIAL FOR TRAINING AND BACKBUILDING CONVECTION IS LOW IN OUR AREA WITH RELATIVELY HIGH MBE VELOCITIES AND THE FACT THAT STORM MOTION BECOMES A LITTLE MORE ORTHOGONAL TO THE FRONT BY TOMORROW. OUTSIDE OF OUR FAR SOUTHEAST COUNTIES...MOST OF THE CWA HAS ALSO NOT RECEIVED A LARGE AMOUNT OF RAIN RECENTLY. THE THREAT FOR HEAVY RAIN AND LOCALIZED FLOODING DOES EXIST BUT CONFIDENCE IS NOT HIGH ENOUGH FOR ANY TYPE OF WATCH HEADLINE AT THIS POINT. AGAIN THE HIGHEST THREAT WILL BE IN OUR FAR SOUTHEAST COUNTIES. && .LONG TERM...(THURSDAY THROUGH WEDNESDAY) ISSUED AT 400 PM EDT WED APR 8 2015 PRIMARY CONCERN WILL BE SEVERE WEATHER CHANCES TONIGHT INTO THURSDAY NIGHT. ALOFT...A DEEP 500MB TROUGH IN THE WESTERN CONUS WILL GRADUALLY SHIFT EASTWARD INTO THE MIDWEST...TAKING ON A NEGATIVE TILT OVER IA/IL AS IT ATTEMPTS TO BREAK DOWN THE RIDGE FIRMLY ANCHORED OVER THE EAST COAST THURSDAY NIGHT. MODELS CLOSE THE LOW THU EVE BEFORE LIFTING IT INTO SOUTHERN ONTARIO BY FRIDAY AFTERNOON. AHEAD OF THE DEEPENING TROUGH...SFC LOW PRESSURE WILL DEVELOP OVER THE CENTRAL PLAINS THIS EVENING AND TRAVEL NORTHEASTWARD INTO SOUTHWESTERN IOWA BY 12Z THU. AS THE UPPER TROUGH/LOW APPROACHES THE LLJ WILL STRENGTHEN...INTENSIFYING THE WARM AIR/MOISTURE ADVECTION OVER THE CWA OVERNIGHT AND THURSDAY. AS A RESULT...THE CWA WILL BE IN THE WARM SECTOR FROM LATE TONIGHT INTO THURSDAY NIGHT. THIS WILL BRING CHANCES FOR SEVERE WEATHER. MOISTURE IS PLENTIFUL...WITH PWATS INCREASING TO NEAR 1.4 INCHES EARLY THU AFTERNOON. INSTABILITY IS DECENT...WITH LI VALUES RANGING FROM -5 TO -2/SFC BASED CAPE AS HIGH AS 1500 J/KG BY LATE AFTERNOON. 0-6KM SHEAR IS SOMEWHAT PALTRY AT FIRST...AROUND 20-30 KNOTS...BUT PICKS UP TO AROUND 40-50 KNOTS TOWARDS THE LATE AFTERNOON AS THE UPPER LEVEL TROUGH APPROACHES. SHOWER/T-STORM ACTIVITY FROM THE OVERNIGHT PERIOD WILL LIKELY CONTINUE THROUGH THE MORNING HOURS...WITH MODELS SUPPORTING SHOWER/T-STORM DEVELOPMENT ALONG THE STATIONARY/WARM FRONT THAT LIFTS NORTHWARD WITH THE BOUNDARY THROUGH THE MORNING. SEVERE POTENTIAL EARLIER IN THE DAY WILL BE LIMITED...WITH MORE MARGINAL INSTABILITY AND WEAK MID LEVEL LAPSE RATES. WITH ABUNDANT MOISTURE...AND WITH ANY THUNDERSTORMS...HEAVY RAIN IS A THREAT. FLOODING IS POSSIBLE IN AREAS THAT SEE HEAVY RAINFALL FROM SEVERAL ROUNDS OF STORMS TONIGHT INTO FRIDAY. THE STRONGEST STORMS ARE FORECAST TO INTIATE WITH THE COLD FRONT OVER THE IL AREA BY THU AFTERNOON...WHERE FRONT TIMING IS MORE FAVORABLE FOR SEVERE WX...DURING PEAK DAYTIME HEATING. EXPECT THESE STORMS TO CROSS INTO OUR WESTERN CWA WITH THE FRONT BY THURSDAY EVENING AND CONTINUE GENERALLY EASTWARD OVERNIGHT. THINKING THE 00-05Z TIME PERIOD IN THE WEST AND CENTRAL WILL BE THE BEST SHOT FOR SEVERE WEATHER...WHEN ALL SVR T-STORM INGREDIENTS COME TOGETHER FOR A BRIEF TIME. PRIMARY THREAT WOULD BE LARGE HAIL AND DAMAGING WINDS...BUT CANNOT RULE OUT THE POSSIBILITY OF TORNADOES GIVEN 0-1 KM SHEAR GREATER THAN 30 KNOTS FROM 00-05Z. THINKING THAT THE BIGGEST LIMITATION WITH THIS OVERALL SCENARIO IS INSTABILITY...MODELS TEND TO OVERDO IT IN GENERAL. THIS IS ESPECIALLY TRUE GIVEN THE UNCERTAINTY WITH THE MORNING CONVECTION...AND THE LATE TIMING OF THE COLD FRONT/MAJOR FORCING. TOOK A LOOK AT THE SHERB PARAMETER WHICH HAS SHOWN SOME SKILL IN EVALUATING HSLC ENVIRONMENTS FOR SEVERE POTENTIAL...AND VALUES WERE OVER 1-WHICH SUGGESTS A MORE SIGNIFICANT EVENT IS POSSIBLE. AFTER 03Z HOWEVER...INSTABILITY REALLY BEGINS TO WANE...AND DRIER AIR BEHIND THE FRONT QUICKLY INFILTRATES THE AREA. WOULD EXPECT ALL MEASURABLE PRECIP TO EXIT THE CWA BY 15Z FRI AS HIGH PRESSURE STARTS TO BUILD INTO THE AREA. A SECONDARY SHORTWAVE ROTATING AROUND THE UPPER LOW OVER SOUTHERN ONTARIO WILL DIVE SOUTHWARD FROM WI. MODELS SUGGEST PRECIPITATION CHANCES ASSOCIATED WITH THIS ACROSS SOUTHWESTERN/SOUTHERN LOWER MI...BUT THESE WILL BE LIMITED AT BEST. WINDS SHOULD GET GUSTY FRIDAY THOUGH...WITH A DECENT PRESSURE RISE/FALL COUPLET CROSSING THE CWA FRIDAY INTO FRI NIGHT. ALL GOES QUIET AGAIN WITH HIGH PRESSURE OVERHEAD...UNTIL SUNDAY NIGHT. AN UPPER LEVEL TROUGH/ASSOCIATED SURFACE LOW WILL MOVE FROM NORTHERN ONTARIO/UPPER MI/NORTHERN WI SUNDAY NIGHT AND CONTINUE INTO HUDSON BAY BY MONDAY AFTERNOON. THIS WILL BRING A COLD FRONT AND ADDITIONAL CHANCES FOR SHOWERS/T-STORMS DURING THIS TIME FRAME. AROUND THE SAME TIME...ANOTHER LOW DEVELOPS OVER THE CENTRAL PLAINS AND BEGINS TO LIFT NORTHWARD...WEAKENING AS IT LIFTS TOWARDS THE OHIO VALLEY TUE AND WED. THIS WILL ALLOW PRECIPITATION TO CONTINUE THROUGH MUCH OF NEXT WEEK. TEMPS WILL BE NEAR NORMAL FOR THIS TIME FRAME...MAINLY IN THE 60S AND LOW 70S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 200 PM EDT WED APR 8 2015 SHORTWAVE RIDGING IN THE WAKE OF MORNING CONVECTION IS CURRENTLY PROVIDING A BREAK IN PRECIP ALONG WITH AN AREA OF VFR CONDITIONS ACROSS NORTHERN INDIANA. PRECIP AND LOW LEVEL MOISTURE WILL RETURN TONIGHT AS ANOTHER SHORTWAVE TROUGH MOVES OVER THE AREA AND THE LLJ RAMPS UP. CONFIDENCE IN TIMING AND COVERAGE OF THUNDERSTORMS IS LOW AT THIS POINT AND WILL DEPEND ON HOW CONVECTION UPSTREAM UNFOLDS. HELD WITH INHERITED BROAD BRUSH VCTS MENTION BUT SHOULD BE ABLE TO NARROW DOWN AND REFINE THAT TIMING LATER THIS EVENING. CONVECTION MAY PERSIST/RE-DEVELOP AFTER 12Z TOMORROW BUT CONFIDENCE IS TOO LOW FOR INCLUSION IN THE TAF AT THIS TIME. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...JT SHORT TERM...AGD LONG TERM...MCD AVIATION...AGD VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
201 PM EDT WED APR 8 2015 .SYNOPSIS... ISSUED AT 1003 AM EDT WED APR 8 2015 SEVERAL PERIODS OF RAIN WILL BE POSSIBLE DURING THE NEXT COUPLE OF DAYS. A STATIONARY FRONT OVER CENTRAL PORTIONS OF INDIANA AND OHIO IS EXPECTED TO LIFT SLOWLY NORTH INTO MICHIGAN TONIGHT. SCATTERED THUNDERSTORMS ARE POSSIBLE NEAR THE FRONT TODAY WITH SHOWERS AND THUNDERSTORMS LIKELY BECOMING NUMEROUS TONIGHT. A COLD FRONT WILL APPROACH THE AREA ON THURSDAY LIKELY CAUSING ANOTHER ROUND OF THUNDERSTORMS. HIGHS TODAY ARE EXPECTED TO RANGE FROM THE MID 50S NORTH OF THE FRONT IN SOUTHERN MICHIGAN TO THE LOW 70S SOUTH OF THE FRONT SOUTH OF US 30. LOWS TONIGHT WILL BE IN THE 50S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 419 AM EDT WED APR 8 2015 THE CLOUDY...COOL PATTERN CONTINUES AS WE MAINTAIN OUR POSITION NORTH OF THE STATIONARY FRONT. A WEAK SHORTWAVE HAS TRIGGERED SOME CONVECTION IN SE IOWA/ WESTERN ILLINOIS JUST NORTH OF THIS STATIONARY FRONT. THE STORMS SEEM TO BE STRUGGLING WITH EASTWARD EXTENT...LIKELY DUE TO A SLIGHTLY STRONGER CAP AT 650MB AND LESS INFLUENCE FROM THE MID LEVEL WAVE. GIVEN THE REMAINING UNCERTAINTY WITH THE EVOLUTION OF THIS CONVECTIVE COMPLEX AS IT MOVES EASTWARD...HAVE KEPT POPS IN THE HIGH CHANCE RANGE. EXPECT A LULL IN THE PRECIPITATION DURING THE AFTERNOON ON TODAY AS WEAK SHORTWAVE RIDGING BUILDS IN AHEAD OF THE NEXT SHORTWAVE TO EJECT OUT OF THE CENTRAL PLAINS. THIS WILL ALSO ALLOW FOR A LONG AWAITED SHIFT NORTHWARD IN THE FRONTAL BOUNDARY. THIS PSEUDO WARM FRONTAL SURGE WILL CREATE SIGNIFICANT BUST POTENTIAL FOR HIGH TEMPERATURES ON TODAY. AREAS SOUTH OF THE SURFACE FRONT WILL LIKELY WARM INTO THE LOW 70S WITH AREAS NORTH OF THE FRONT REMAINING IN THE MID 50S. THE EXACT PROGRESSION OF THIS FRONT NORTHWARD WILL DICTATE EXACTLY WHO SEES THE WARMER TEMPERATURES...BUT THE LATEST HIRES GUIDANCE PUTS THE MAX NORTHWARD PROGRESSION RIGHT ALONG US30. REGARDLESS OF THE EXACT PLACEMENT OF THIS FRONT...ITS PRESENCE ACROSS OUR AREA MEANS WE WILL BE FAVORABLE FOR THUNDERSTORM DEVELOPMENT DURING THE EVENING AND INTO THE OVERNIGHT HOURS. THERE IS SIGNIFICANT UNCERTAINTY WRT TIMING OF STORMS ACROSS THE AREA. NAM AND RAP HAVE A DECENT SHORTWAVE SPAWNING STORMS NORTH OF SAINT LOUIS DURING THE AFTERNOON AND MOVING THAT MCS THROUGH OUR AREA AROUND 00Z. ONLY GLOBAL GUIDANCE WHICH EVEN HINTS AT A WAVE MOVING THROUGH AT THAT TIME IS THE GEM AND THEREFORE GLOBAL GUIDANCE HOLDS OFF ON CONVECTION UNTIL AFTER MIDNIGHT. IR SATELLITE DOES SHOW SOME COOLER CLOUD TOPS IN SW KANSAS WHERE THIS SW IS CURRENTLY SUPPOSED TO BE...SO AM INCLINED TO BELIEVE THE HIRES GUIDANCE AND DISCOUNT THE GLOBAL GUIDANCE AS LACKING THE RESOLUTION TO PROPERLY RESOLVE THIS WAVE. SEVERE RISK DOES EXIST WITH ANY STORMS THAT DO DEVELOP IN THIS AFTERNOON TIMEFRAME GIVEN 40 TO 50 KNOTS OF DEEP LAYER SHEAR AND 1500 TO 2000 J/KG OF SBCAPE SOUTH OF THE SURFACE FRONT. EVEN IF THE EARLY EVENING STORM DEVELOPMENT ON THE HIRES GUIDANCE DOESN`T MATERIALIZE...THERE WILL STILL BE AN ISOLATED RISK OF SEVERE WEATHER DURING THE OVERNIGHT HOURS GIVEN THE ~2000 J/KG OF MUCAPE AND 30 KNOT LLJ WITH THE REMAINING PRESENCE OF 35 TO 45 KNOTS OF DEEP LAYER SHEAR. && .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 419 AM EDT WED APR 8 2015 PRIMARY CONCERNS FOR THE LONG TERM WILL CENTER ON CONVECTIVE/SEVERE POTENTIAL THURSDAY/THURSDAY NIGHT...FOLLOWED BY RENEWED PRECIP CHANCES EARLY NEXT WEEK. SHOWERS/STORMS WILL LIKELY BE ONGOING THURSDAY MORNING AS UPPER JET STREAK ASSOCIATED WITH SUBTROPICAL JET ENCROACHES ON THE OHIO RIVER VALLEY. AXIS OF 40-50 KNOT SOUTHWESTERLY LOW LEVEL FLOW NOSING INTO THE AREA BY MIDDAY WILL ALLOW FOR APPRECIABLE LOW/MID LEVEL MOISTURE ADVECTION. MOISTURE CONVERGENCE AT NOSE OF STRONGER LOW LEVEL FLOW SHOULD ALLOW POCKET OF PWATS NEAR 1.5 INCHES TO TRACK ACROSS FORECAST AREA THURSDAY MORNING WITH AMPLE ELEVATED MOISTURE FOR SHOWERS AND EMBEDDED THUNDER. POTENTIAL OF SOME LOCALLY HEAVIER RAINFALL AMOUNTS STILL APPEARS TO BE INTACT THROUGH THURSDAY MORNING IN ASSOCIATION WITH THIS FORCING ALONG WITH POTENTIAL OF SOME HAIL GIVEN ELEVATED INSTABILITY AND RELATIVELY LOW FREEZING/WBZ ZERO HEIGHTS BETWEEN 9-10K FT. SOME DEGREE OF UNCERTAINTY REMAINS REGARDING CONVECTIVE EVOLUTION THURSDAY AFTERNOON AND ASSOCIATED IMPACTS ON INSTABILITY MAGNITUDES DURING PEAK HEATING. ATTENTION FOR THURSDAY AFTERNOON/NIGHT WILL SHIFT UPSTREAM TO MORE ROBUST EASTERN PACIFIC WAVE WHICH SHOULD ACQUIRE NEGATIVE TILT ACROSS THE WESTERN GREAT LAKES THURSDAY EVENING. FRONTAL CONVERGENCE AND LEADING EDGE OF MID LEVEL DRY SLOT SHOULD REGENERATE POTENTIALLY VIGOROUS CONVECTIVE DEVELOPMENT ACROSS ILLINOIS DURING THE AFTERNOON...POSSIBLY TRACKING INTO WESTERN PORTIONS OF LOCAL AREA THURSDAY EVENING. EXTENT OF ANY THINNING CLOUD COVER THURSDAY AFTERNOON/LOW LEVEL TEMP TRENDS WILL HAVE A BIG IMPACT ON INSTABILITY MAGNITUDES. GIVEN STRENGTH OF BACKGROUND WIND FIELDS...A WIND THREAT MAY EVOLVE THURSDAY EVENING EVEN IF AFTERNOON INSTABILITY RECOVERY IS SOMEWHAT LIMITED. AS MENTIONED IN PREVIOUS FORECAST...A SOMEWHAT HIGHER SEVERE THREAT MAY UNFOLD IF GREATER LATE AFTERNOON INSTABILITY CAN BE REALIZED GIVEN SUBSTANTIAL SHEAR PROFILES...AND IN LIGHT OF DIFFERENTIAL MOISTURE ADVECTION IMMEDIATELY PRECEDING SFC FRONT THURSDAY NIGHT ASSOCIATED WITH THE DRY SLOT. SPC DAY2 OUTLOOK HAS MAINTAINED HIGHER SVR PROBS ACROSS WESTERN THIRD/HALF OF AREA...WITH POSSIBILITY OF WEAK NEAR SFC DIURNAL COOLING LATER THURSDAY EVENING DIMINISHING INSTABILITY MAGNITUDES A BIT ACROSS THE EAST. ONLY TWEAK TO PREVIOUS FORECAST WAS TO SLIGHTLY SPEED UP TIMING OF WEST TO EAST POP REDUCTION LATER THURSDAY NIGHT FOLLOWING COLD FRONT PROGRESSION. DID MAINTAIN SLIGHT CHANCE RAIN SHOWER POPS ACROSS THE FAR NORTH/FAR EAST EARLY FRIDAY MORNING GIVEN LINGERING MID/UPPER FORCING WITH A SERIES OF SMALLER SCALE WAVES ROTATING THROUGH LONGWAVE TROUGH...BUT ADDITIONAL PRECIP AMOUNTS ACROSS THESE LOCATIONS SHOULD BE QUITE LIGHT. BREEZY/WINDY CONDITIONS CAN ALSO BE EXPECTED WITH DEEPER POST FRONTAL MIXING LATE THURSDAY NIGHT INTO FRIDAY. IT STILL APPEARS AS THOUGH THE FRIDAY NIGHT THROUGH SUNDAY PERIOD SHOULD BE DRY WITH NEAR SEASONABLE TEMPS UNDER INFLUENCE OF MID/UPPER LEVEL RIDGING. LOW LEVEL ANTICYCLONE TO DEPART TO THE EAST SUNDAY NIGHT INTO MONDAY ALLOWING FOR A FAIRLY QUICK TRANSITION TO STRONGER LOW LEVEL MOISTURE TRANSPORT FOR MONDAY. GOOD MOISTURE AVAILABILITY AND APPROACH OF CUT-OFF SOUTHERN STREAM PV ANOMALY FOR TUE/WED SHOULD KEEP CHANCES OF SHOWERS AND STORMS GOING THROUGH THE END OF THE PERIOD AS THIS WAVE EVENTUALLY DAMPENS ACROSS THE AREA. THIS PATTERN WILL ALSO BE CONDUCIVE FOR SHARPLY MODERATING TEMPERATURES ONCE AGAIN FOR EARLY NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 200 PM EDT WED APR 8 2015 SHORTWAVE RIDGING IN THE WAKE OF MORNING CONVECTION IS CURRENTLY PROVIDING A BREAK IN PRECIP ALONG WITH AN AREA OF VFR CONDITIONS ACROSS NORTHERN INDIANA. PRECIP AND LOW LEVEL MOISTURE WILL RETURN TONIGHT AS ANOTHER SHORTWAVE TROUGH MOVES OVER THE AREA AND THE LLJ RAMPS UP. CONFIDENCE IN TIMING AND COVERAGE OF THUNDERSTORMS IS LOW AT THIS POINT AND WILL DEPEND ON HOW CONVECTION UPSTREAM UNFOLDS. HELD WITH INHERITED BROAD BRUSH VCTS MENTION BUT SHOULD BE ABLE TO NARROW DOWN AND REFINE THAT TIMING LATER THIS EVENING. CONVECTION MAY PERSIST/RE-DEVELOP AFTER 12Z TOMORROW BUT CONFIDENCE IS TOO LOW FOR INCLUSION IN THE TAF AT THIS TIME. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...JT SHORT TERM...BENTLEY LONG TERM...MARSILI AVIATION...AGD VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1257 PM EDT WED APR 8 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 304 AM EDT WED APR 8 2015 A FRONTAL SYSTEM IS EXPECTED TO REMAIN ACROSS THE AREA THROUGH TONIGHT...BEFORE LIFTING OFF TO THE NORTH ON THURSDAY. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA THURSDAY NIGHT. IN THE WAKE OF THIS FRONT...HIGH PRESSURE WILL MOVE INTO THE AREA OVER THE WEEKEND. ANOTHER FRONTAL SYSTEM MAY AFFECT THE AREA BY EARLY NEXT WEEK. && .NEAR TERM /TODAY/... ISSUED AT 1028 AM EDT WED APR 8 2015 THERE SHOULD BE A BREAK IN THE ACTION THANKS TO STABILIZATION FROM THIS MORNINGS SYSTEM. HOWEVER THE HRRR REINTRODUCES PRECIPITATION DURING THE AFTERNOON AS A WARM HUMID FLOW CONTINUES FROM THE SOUTHWEST. ALSO...BASED ON WHAT WE SEE IN ILLINOIS THERE MAY WELL BE SOME BREAKS EARLY IN THE AFTERNOON WHICH WOULD LEAD TO RAPID DESTABILIZATION. ALL THINGS CONSIDERED...LIKELY POPS SEEM BEST OVER THE SOUTHERN CWA MOST OF THE AFTERNOON AND OVER THE ENTIRE CWA BY LATER AFTERNOON. FORECAST TEMPERATURES FOR TODAY MIGHT BE TOO HIGH. HOWEVER WITH EVEN A FEW BREAKS THE THERMOMETER WILL ROCKET UP. HIGHS FROM THE EARLIER FORECAST WILL BE KEPT IN THE UPDATE. && .SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/... ISSUED AT 304 AM EDT WED APR 8 2015 SURFACE WAVE EXPECTED TO MOVE ACROSS NORTHERN INDIANA TONIGHT...WHICH MAY ALLOW FOR THE FRONT TO SAG BACK TO THE SOUTH TEMPORARILY. MODELS SUGGEST A STRONGER LOW LEVEL JET...ON THE ORDER OF AROUND 40 KTS...WILL BE NOSING TOWARDS WESTERN INDIANA LATE TONIGHT. AS A RESULT...THINK THE POTENTIAL FOR CONVECTION WILL BE HIGHER TONIGHT. WILL GO WITH HIGH POPS OVER THE NORTHERN AND CENTRAL ZONES...TAPERING OFF TO CHANCE POPS OVER THE SOUTH. LAPSE RATES AND DEEP LAYER SHEAR SUGGEST POTENTIAL FOR ORGANIZED SEVERE STORMS TONIGHT. WILL CONTINUE WITH HIGH POPS ON THURSDAY AND THURSDAY NIGHT AS PROGGED LOW LEVEL JET OF 45-50 KTS INTERACTS WITH AN APPROACHING UPPER TROUGH AND SURFACE COLD FRONT. MAY BE A LULL IN THE PRECIPITATION THREAT THURSDAY AFTERNOON AS THE LOCAL AREA GETS FURTHER INTO THE WARM SECTOR BEFORE COLD FRONT ARRIVES THURSDAY EVENING...BUT WON/T GET TOO DETAILED IN THE TIMING AT THIS POINT. APPEARS DEEP SHEAR WILL BE MAXIMIZED OVER THE AREA THURSDAY NIGHT AS THE CORE OF THE MID LEVEL JET APPROACHES. POTENTIAL FOR SEVERE WILL CONTINUE UNTIL FRONTAL PASSAGE LATE THURSDAY NIGHT. FRONTAL SHOULD BE FAR ENOUGH OFF TO THE EAST BY FRIDAY MORNING TO GO DRY FOR FRIDAY AND FRIDAY NIGHT. LOW LEVEL THICKNESS PROGS SUGGEST THE GFS MOS TEMPERATURE GUIDANCE IN THE LATER PERIODS LOOK REASONABLE AT THIS POINT...ALTHOUGH THE LOWS FRIDAY MORNING LOOK TOO WARM IN THE WAKE OF THE COLD FRONT. WILL LOWER THEM ABOUT 3-5 DEGREES IN THAT PERIOD. && .LONG TERM /SATURDAY THROUGH TUESDAY/... ISSUED AT 304 AM EDT WED APR 8 2015 DRY PLEASANT WEATHER EXPECTED FOR MUCH OF THE WEEKEND AS HIGH PRESSURE MOVES THROUGH THE OHIO VALLEY. AN UPPER TROUGH WILL BE IN THE PROCESS OF MOVING AWAY TO THE EAST ON SATURDAY...WITH RIDGING ALOFT AND WARM ADVECTION DEVELOPING FOR THE SECOND HALF OF THE WEEKEND. HIGHS IN THE UPPER 50S AND LOWER 60S SATURDAY WILL WARM PRIMARILY INTO THE 60S FOR SUNDAY. UNSETTLED WEATHER THEN RETURNS FOR MUCH OF THE REST OF THE EXTENDED. BROAD UPPER TROUGH EXPANDING ACROSS THE PACIFIC NORTHWEST AND NORTHERN PLAINS WILL SERVE TO FLATTEN THE RIDGE BY LATE WEEKEND WITH MOISTURE INCREASING AS A WEAK FRONT MOVES INTO THE GREAT LAKES. COULD SEE A FEW SHOWERS BY SUNDAY AFTERNOON OVER WESTERN COUNTIES WITH MORE EXTENSIVE PRECIP COVERAGE SUNDAY NIGHT AS THE SYSTEM TAPS INTO A GULF MOISTURE FETCH. FAST MOVING UPPER LOW TRACKING WITH THE SUBTROPICAL JET WILL MOVE FROM BAJA CALIFORNIA EARLY SUNDAY INTO THE SOUTHERN PLAINS BY LATE MONDAY WITH SURFACE CYCLOGENESIS BY MONDAY NIGHT. WARM FRONT SETS UP INTO THE OHIO VALLEY LATE MONDAY THROUGH TUESDAY AND WILL PROMOTE ANOTHER PERIOD WITH SHOWERS AND THUNDERSTORMS AS THE SURFACE WAVE TRACKS INTO THE REGION BY EARLY WEDNESDAY. WILL CARRY CHANCE POPS FROM SUNDAY NIGHT INTO MIDWEEK. HIGHS WILL LARGELY REMAIN IN THE 60S FOR MONDAY AND TUESDAY AS CLOUDS AND RAINFALL LIKELY TO LIMIT TEMP RISES. && .AVIATION /DISCUSSION FOR 081800Z TAFS/... ISSUED AT 1246 PM EDT WED APR 8 2015 HIGH UNCERTAINTY IN FORECAST. MORNING CONVECTION HAS LAID DOWN OUTFLOW BOUNDARIES WHILE SOUTHWEST FLOW PUMPING WARMER AND MORE HUMID AIR TOWARD TAF SITES HAS RESULTED IN MVFR DECK 1500-2000 FT. THINKING IS THIS SITUATION IS WARM FRONTAL LIKE AND AS BOUNDARY PUSHES BACK NORTHEAST AND SUN CONTINUE WORKING ON CLOUDS THIS MVFR DECK SHOULD SCATTER TO A LAYER AROUND 2500 FEET. OTHER FACTOR IS THE CIRRUS DEBRIS FROM MISSOURI STORMS HAS OVERSPREAD INDIANA AND ILLINOIS AND SERVING TO LIMIT CUMULUS GROWTH. CERTAINLY SURFACE BOUNDARIES AVAILABLE TO HELP WITH LIFT BUT MOST MODELS KEY ON NEXT UPPER SUPPORT ARRIVING AFTER 090600Z. THUS ANY CONVECTION PRIOR WILL BE ISOLATED OR SCATTERED...FOCUSED ON MESO BOUNDARY AND DRIVEN BY WHAT HEATING MAY OCCUR TODAY. ANTICIPATE THUNDERSTORM COMPLEX WITH WIDESPREAD STORMS TO ARRIVE AFTER 090600Z WITH UPPER SUPPORT. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...JAS NEAR TERM...JK SHORT TERM...JAS LONG TERM....RYAN AVIATION...TUCEK VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1029 AM EDT WED APR 8 2015 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 304 AM EDT WED APR 8 2015 A FRONTAL SYSTEM IS EXPECTED TO REMAIN ACROSS THE AREA THROUGH TONIGHT...BEFORE LIFTING OFF TO THE NORTH ON THURSDAY. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA THURSDAY NIGHT. IN THE WAKE OF THIS FRONT...HIGH PRESSURE WILL MOVE INTO THE AREA OVER THE WEEKEND. ANOTHER FRONTAL SYSTEM MAY AFFECT THE AREA BY EARLY NEXT WEEK. && .NEAR TERM /TODAY/... ISSUED AT 1028 AM EDT WED APR 8 2015 THERE SHOULD BE A BREAK IN THE ACTION THANKS TO STABILIZATION FROM THIS MORNINGS SYSTEM. HOWEVER THE HRRR REINTRODUCES PRECIPITATION DURING THE AFTERNOON AS A WARM HUMID FLOW CONTINUES FROM THE SOUTHWEST. ALSO...BASED ON WHAT WE SEE IN ILLINOIS THERE MAY WELL BE SOME BREAKS EARLY IN THE AFTERNOON WHICH WOULD LEAD TO RAPID DESTABILIZATION. ALL THINGS CONSIDERED...LIKELY POPS SEEM BEST OVER THE SOUTHERN CWA MOST OF THE AFTERNOON AND OVER THE ENTIRE CWA BY LATER AFTERNOON. FORECAST TEMPERATURES FOR TODAY MIGHT BE TOO HIGH. HOWEVER WITH EVEN A FEW BREAKS THE THERMOMETER WILL ROCKET UP. HIGHS FROM THE EARLIER FORECAST WILL BE KEPT IN THE UPDATE. && .SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/... ISSUED AT 304 AM EDT WED APR 8 2015 SURFACE WAVE EXPECTED TO MOVE ACROSS NORTHERN INDIANA TONIGHT...WHICH MAY ALLOW FOR THE FRONT TO SAG BACK TO THE SOUTH TEMPORARILY. MODELS SUGGEST A STRONGER LOW LEVEL JET...ON THE ORDER OF AROUND 40 KTS...WILL BE NOSING TOWARDS WESTERN INDIANA LATE TONIGHT. AS A RESULT...THINK THE POTENTIAL FOR CONVECTION WILL BE HIGHER TONIGHT. WILL GO WITH HIGH POPS OVER THE NORTHERN AND CENTRAL ZONES...TAPERING OFF TO CHANCE POPS OVER THE SOUTH. LAPSE RATES AND DEEP LAYER SHEAR SUGGEST POTENTIAL FOR ORGANIZED SEVERE STORMS TONIGHT. WILL CONTINUE WITH HIGH POPS ON THURSDAY AND THURSDAY NIGHT AS PROGGED LOW LEVEL JET OF 45-50 KTS INTERACTS WITH AN APPROACHING UPPER TROUGH AND SURFACE COLD FRONT. MAY BE A LULL IN THE PRECIPITATION THREAT THURSDAY AFTERNOON AS THE LOCAL AREA GETS FURTHER INTO THE WARM SECTOR BEFORE COLD FRONT ARRIVES THURSDAY EVENING...BUT WON/T GET TOO DETAILED IN THE TIMING AT THIS POINT. APPEARS DEEP SHEAR WILL BE MAXIMIZED OVER THE AREA THURSDAY NIGHT AS THE CORE OF THE MID LEVEL JET APPROACHES. POTENTIAL FOR SEVERE WILL CONTINUE UNTIL FRONTAL PASSAGE LATE THURSDAY NIGHT. FRONTAL SHOULD BE FAR ENOUGH OFF TO THE EAST BY FRIDAY MORNING TO GO DRY FOR FRIDAY AND FRIDAY NIGHT. LOW LEVEL THICKNESS PROGS SUGGEST THE GFS MOS TEMPERATURE GUIDANCE IN THE LATER PERIODS LOOK REASONABLE AT THIS POINT...ALTHOUGH THE LOWS FRIDAY MORNING LOOK TOO WARM IN THE WAKE OF THE COLD FRONT. WILL LOWER THEM ABOUT 3-5 DEGREES IN THAT PERIOD. && .LONG TERM /SATURDAY THROUGH TUESDAY/... ISSUED AT 304 AM EDT WED APR 8 2015 DRY PLEASANT WEATHER EXPECTED FOR MUCH OF THE WEEKEND AS HIGH PRESSURE MOVES THROUGH THE OHIO VALLEY. AN UPPER TROUGH WILL BE IN THE PROCESS OF MOVING AWAY TO THE EAST ON SATURDAY...WITH RIDGING ALOFT AND WARM ADVECTION DEVELOPING FOR THE SECOND HALF OF THE WEEKEND. HIGHS IN THE UPPER 50S AND LOWER 60S SATURDAY WILL WARM PRIMARILY INTO THE 60S FOR SUNDAY. UNSETTLED WEATHER THEN RETURNS FOR MUCH OF THE REST OF THE EXTENDED. BROAD UPPER TROUGH EXPANDING ACROSS THE PACIFIC NORTHWEST AND NORTHERN PLAINS WILL SERVE TO FLATTEN THE RIDGE BY LATE WEEKEND WITH MOISTURE INCREASING AS A WEAK FRONT MOVES INTO THE GREAT LAKES. COULD SEE A FEW SHOWERS BY SUNDAY AFTERNOON OVER WESTERN COUNTIES WITH MORE EXTENSIVE PRECIP COVERAGE SUNDAY NIGHT AS THE SYSTEM TAPS INTO A GULF MOISTURE FETCH. FAST MOVING UPPER LOW TRACKING WITH THE SUBTROPICAL JET WILL MOVE FROM BAJA CALIFORNIA EARLY SUNDAY INTO THE SOUTHERN PLAINS BY LATE MONDAY WITH SURFACE CYCLOGENESIS BY MONDAY NIGHT. WARM FRONT SETS UP INTO THE OHIO VALLEY LATE MONDAY THROUGH TUESDAY AND WILL PROMOTE ANOTHER PERIOD WITH SHOWERS AND THUNDERSTORMS AS THE SURFACE WAVE TRACKS INTO THE REGION BY EARLY WEDNESDAY. WILL CARRY CHANCE POPS FROM SUNDAY NIGHT INTO MIDWEEK. HIGHS WILL LARGELY REMAIN IN THE 60S FOR MONDAY AND TUESDAY AS CLOUDS AND RAINFALL LIKELY TO LIMIT TEMP RISES. && .AVIATION /UPDATE FOR 081200Z TAFS/... ISSUED AT 956 AM EDT WED APR 8 2015 FIRST THUNDERSTORM COMPLEX EXITING TAF SITES AT 081400Z AFTER PRODUCING A LOT OF QUARTER INCH TO HALF INCH DIAMETER HAIL AND ISOLATED 40 KNOT WIND GUSTS. TORRENTIAL RAINS ALSO DROPPED VISIBILITIES TO AROUND ONE MILE BRIEFLY. WINDS SWITCHED TO NORTHWEST WITH SQUALL LINE PASSAGE AND ARE CURRENTLY WORKING THERE WAY AROUND THE DIAL FROM EAST TO SOUTHEAST AND EVENTUALLY TO SOUTH AND SOUTHWEST BY 081700Z AND BECOMING GUSTY. CLOUD DECKS BRIEFLY DROPPED BELOW 2000 FEET AT CORE OF STORMS BUT HAVE RECOVERED TO BASES OVER 3000 FEET. FORECASTS WILL BE ADJUSTED TO VFR VSBY AND CLOUD DECKS WHILE WINDS WORK THERE WAY BACK TO SOUTH. THE FEW CELLS REFORMING IN EASTERN ILLINOIS DO NOT APPEAR TO GROW IN COVERAGE BUT WILL BE THREAT TO TERRE HAUTE THROUGH 081600Z. MISSOURI THUNDERSTORM COMPLEX LIKELY TO BECOME A PLAYER FOR CENTRAL INDIANA TAF SITES LATE THIS AFTERNOON AND EVENING. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...JAS NEAR TERM...JK SHORT TERM...JAS LONG TERM....RYAN AVIATION...TUCEK VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1011 AM EDT WED APR 8 2015 .SYNOPSIS... ISSUED AT 1003 AM EDT WED APR 8 2015 SEVERAL PERIODS OF RAIN WILL BE POSSIBLE DURING THE NEXT COUPLE OF DAYS. A STATIONARY FRONT OVER CENTRAL PORTIONS OF INDIANA AND OHIO IS EXPECTED TO LIFT SLOWLY NORTH INTO MICHIGAN TONIGHT. SCATTERED THUNDERSTORMS ARE POSSIBLE NEAR THE FRONT TODAY WITH SHOWERS AND THUNDERSTORMS LIKELY BECOMING NUMEROUS TONIGHT. A COLD FRONT WILL APPROACH THE AREA ON THURSDAY LIKELY CAUSING ANOTHER ROUND OF THUNDERSTORMS. HIGHS TODAY ARE EXPECTED TO RANGE FROM THE MID 50S NORTH OF THE FRONT IN SOUTHERN MICHIGAN TO THE LOW 70S SOUTH OF THE FRONT SOUTH OF US 30. LOWS TONIGHT WILL BE IN THE 50S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 419 AM EDT WED APR 8 2015 THE CLOUDY...COOL PATTERN CONTINUES AS WE MAINTAIN OUR POSITION NORTH OF THE STATIONARY FRONT. A WEAK SHORTWAVE HAS TRIGGERED SOME CONVECTION IN SE IOWA/ WESTERN ILLINOIS JUST NORTH OF THIS STATIONARY FRONT. THE STORMS SEEM TO BE STRUGGLING WITH EASTWARD EXTENT...LIKELY DUE TO A SLIGHTLY STRONGER CAP AT 650MB AND LESS INFLUENCE FROM THE MID LEVEL WAVE. GIVEN THE REMAINING UNCERTAINTY WITH THE EVOLUTION OF THIS CONVECTIVE COMPLEX AS IT MOVES EASTWARD...HAVE KEPT POPS IN THE HIGH CHANCE RANGE. EXPECT A LULL IN THE PRECIPITATION DURING THE AFTERNOON ON TODAY AS WEAK SHORTWAVE RIDGING BUILDS IN AHEAD OF THE NEXT SHORTWAVE TO EJECT OUT OF THE CENTRAL PLAINS. THIS WILL ALSO ALLOW FOR A LONG AWAITED SHIFT NORTHWARD IN THE FRONTAL BOUNDARY. THIS PSEUDO WARM FRONTAL SURGE WILL CREATE SIGNIFICANT BUST POTENTIAL FOR HIGH TEMPERATURES ON TODAY. AREAS SOUTH OF THE SURFACE FRONT WILL LIKELY WARM INTO THE LOW 70S WITH AREAS NORTH OF THE FRONT REMAINING IN THE MID 50S. THE EXACT PROGRESSION OF THIS FRONT NORTHWARD WILL DICTATE EXACTLY WHO SEES THE WARMER TEMPERATURES...BUT THE LATEST HIRES GUIDANCE PUTS THE MAX NORTHWARD PROGRESSION RIGHT ALONG US30. REGARDLESS OF THE EXACT PLACEMENT OF THIS FRONT...ITS PRESENCE ACROSS OUR AREA MEANS WE WILL BE FAVORABLE FOR THUNDERSTORM DEVELOPMENT DURING THE EVENING AND INTO THE OVERNIGHT HOURS. THERE IS SIGNIFICANT UNCERTAINTY WRT TIMING OF STORMS ACROSS THE AREA. NAM AND RAP HAVE A DECENT SHORTWAVE SPAWNING STORMS NORTH OF SAINT LOUIS DURING THE AFTERNOON AND MOVING THAT MCS THROUGH OUR AREA AROUND 00Z. ONLY GLOBAL GUIDANCE WHICH EVEN HINTS AT A WAVE MOVING THROUGH AT THAT TIME IS THE GEM AND THEREFORE GLOBAL GUIDANCE HOLDS OFF ON CONVECTION UNTIL AFTER MIDNIGHT. IR SATELLITE DOES SHOW SOME COOLER CLOUD TOPS IN SW KANSAS WHERE THIS SW IS CURRENTLY SUPPOSED TO BE...SO AM INCLINED TO BELIEVE THE HIRES GUIDANCE AND DISCOUNT THE GLOBAL GUIDANCE AS LACKING THE RESOLUTION TO PROPERLY RESOLVE THIS WAVE. SEVERE RISK DOES EXIST WITH ANY STORMS THAT DO DEVELOP IN THIS AFTERNOON TIMEFRAME GIVEN 40 TO 50 KNOTS OF DEEP LAYER SHEAR AND 1500 TO 2000 J/KG OF SBCAPE SOUTH OF THE SURFACE FRONT. EVEN IF THE EARLY EVENING STORM DEVELOPMENT ON THE HIRES GUIDANCE DOESN`T MATERIALIZE...THERE WILL STILL BE AN ISOLATED RISK OF SEVERE WEATHER DURING THE OVERNIGHT HOURS GIVEN THE ~2000 J/KG OF MUCAPE AND 30 KNOT LLJ WITH THE REMAINING PRESENCE OF 35 TO 45 KNOTS OF DEEP LAYER SHEAR. && .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 419 AM EDT WED APR 8 2015 PRIMARY CONCERNS FOR THE LONG TERM WILL CENTER ON CONVECTIVE/SEVERE POTENTIAL THURSDAY/THURSDAY NIGHT...FOLLOWED BY RENEWED PRECIP CHANCES EARLY NEXT WEEK. SHOWERS/STORMS WILL LIKELY BE ONGOING THURSDAY MORNING AS UPPER JET STREAK ASSOCIATED WITH SUBTROPICAL JET ENCROACHES ON THE OHIO RIVER VALLEY. AXIS OF 40-50 KNOT SOUTHWESTERLY LOW LEVEL FLOW NOSING INTO THE AREA BY MIDDAY WILL ALLOW FOR APPRECIABLE LOW/MID LEVEL MOISTURE ADVECTION. MOISTURE CONVERGENCE AT NOSE OF STRONGER LOW LEVEL FLOW SHOULD ALLOW POCKET OF PWATS NEAR 1.5 INCHES TO TRACK ACROSS FORECAST AREA THURSDAY MORNING WITH AMPLE ELEVATED MOISTURE FOR SHOWERS AND EMBEDDED THUNDER. POTENTIAL OF SOME LOCALLY HEAVIER RAINFALL AMOUNTS STILL APPEARS TO BE INTACT THROUGH THURSDAY MORNING IN ASSOCIATION WITH THIS FORCING ALONG WITH POTENTIAL OF SOME HAIL GIVEN ELEVATED INSTABILITY AND RELATIVELY LOW FREEZING/WBZ ZERO HEIGHTS BETWEEN 9-10K FT. SOME DEGREE OF UNCERTAINTY REMAINS REGARDING CONVECTIVE EVOLUTION THURSDAY AFTERNOON AND ASSOCIATED IMPACTS ON INSTABILITY MAGNITUDES DURING PEAK HEATING. ATTENTION FOR THURSDAY AFTERNOON/NIGHT WILL SHIFT UPSTREAM TO MORE ROBUST EASTERN PACIFIC WAVE WHICH SHOULD ACQUIRE NEGATIVE TILT ACROSS THE WESTERN GREAT LAKES THURSDAY EVENING. FRONTAL CONVERGENCE AND LEADING EDGE OF MID LEVEL DRY SLOT SHOULD REGENERATE POTENTIALLY VIGOROUS CONVECTIVE DEVELOPMENT ACROSS ILLINOIS DURING THE AFTERNOON...POSSIBLY TRACKING INTO WESTERN PORTIONS OF LOCAL AREA THURSDAY EVENING. EXTENT OF ANY THINNING CLOUD COVER THURSDAY AFTERNOON/LOW LEVEL TEMP TRENDS WILL HAVE A BIG IMPACT ON INSTABILITY MAGNITUDES. GIVEN STRENGTH OF BACKGROUND WIND FIELDS...A WIND THREAT MAY EVOLVE THURSDAY EVENING EVEN IF AFTERNOON INSTABILITY RECOVERY IS SOMEWHAT LIMITED. AS MENTIONED IN PREVIOUS FORECAST...A SOMEWHAT HIGHER SEVERE THREAT MAY UNFOLD IF GREATER LATE AFTERNOON INSTABILITY CAN BE REALIZED GIVEN SUBSTANTIAL SHEAR PROFILES...AND IN LIGHT OF DIFFERENTIAL MOISTURE ADVECTION IMMEDIATELY PRECEDING SFC FRONT THURSDAY NIGHT ASSOCIATED WITH THE DRY SLOT. SPC DAY2 OUTLOOK HAS MAINTAINED HIGHER SVR PROBS ACROSS WESTERN THIRD/HALF OF AREA...WITH POSSIBILITY OF WEAK NEAR SFC DIURNAL COOLING LATER THURSDAY EVENING DIMINISHING INSTABILITY MAGNITUDES A BIT ACROSS THE EAST. ONLY TWEAK TO PREVIOUS FORECAST WAS TO SLIGHTLY SPEED UP TIMING OF WEST TO EAST POP REDUCTION LATER THURSDAY NIGHT FOLLOWING COLD FRONT PROGRESSION. DID MAINTAIN SLIGHT CHANCE RAIN SHOWER POPS ACROSS THE FAR NORTH/FAR EAST EARLY FRIDAY MORNING GIVEN LINGERING MID/UPPER FORCING WITH A SERIES OF SMALLER SCALE WAVES ROTATING THROUGH LONGWAVE TROUGH...BUT ADDITIONAL PRECIP AMOUNTS ACROSS THESE LOCATIONS SHOULD BE QUITE LIGHT. BREEZY/WINDY CONDITIONS CAN ALSO BE EXPECTED WITH DEEPER POST FRONTAL MIXING LATE THURSDAY NIGHT INTO FRIDAY. IT STILL APPEARS AS THOUGH THE FRIDAY NIGHT THROUGH SUNDAY PERIOD SHOULD BE DRY WITH NEAR SEASONABLE TEMPS UNDER INFLUENCE OF MID/UPPER LEVEL RIDGING. LOW LEVEL ANTICYCLONE TO DEPART TO THE EAST SUNDAY NIGHT INTO MONDAY ALLOWING FOR A FAIRLY QUICK TRANSITION TO STRONGER LOW LEVEL MOISTURE TRANSPORT FOR MONDAY. GOOD MOISTURE AVAILABILITY AND APPROACH OF CUT-OFF SOUTHERN STREAM PV ANOMALY FOR TUE/WED SHOULD KEEP CHANCES OF SHOWERS AND STORMS GOING THROUGH THE END OF THE PERIOD AS THIS WAVE EVENTUALLY DAMPENS ACROSS THE AREA. THIS PATTERN WILL ALSO BE CONDUCIVE FOR SHARPLY MODERATING TEMPERATURES ONCE AGAIN FOR EARLY NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 639 AM EDT WED APR 8 2015 A SHORT WAVE ACROSS CENTRAL ILLINOIS AND ACCOMPANYING LOW LEVEL WARM/MOIST ADVECTION HAS LED TO SUFFICIENT ELEVATED INSTABILITY FOR SCATTERED SHOWERS AND THUNDERSTORMS. ORIENTATION OF THE LOW LEVEL WARM FRONT WOULD SUGGEST BEST CHANCE OF THUNDER ALONG AND SOUTH OF ROUTE 30 THROUGH AROUND 15Z. VEERING LOW LEVEL JET SHOULD TEND TO WEAKEN LOW LEVEL MOISTURE CONVERGENCE A BIT OVER THE NEXT HOUR OR TWO...SO STILL SOME UNCERTAINTY AS TO COVERAGE OF TS AS FAR EAST AS KFWA BUT MAY NEED TO CARRY VCTS FOR A FEW HOURS. LIFR CONDITIONS SHOULD GRADUALLY IMPROVE TO LOWER END MVFR FROM SOUTH TO NORTH LATER THIS MORNING INTO EARLY AFTERNOON AS WARM FRONT EDGES A BIT FARTHER NORTH. THE NEXT FAST MOVING SHORT WAVE EJECTING OUT OF SOUTHWEST CONUS TONIGHT WILL ALLOW FOR RENEWED LOW LEVEL THETAE ADVECTION AND AN INCREASING CHANCE OF SHOWERS/STORMS. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...JT SHORT TERM...BENTLEY LONG TERM...MARSILI AVIATION...MARSILI VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
423 AM EDT WED APR 8 2015 .SYNOPSIS... ISSUED AT 423 AM EDT WED APR 8 2015 SEVERAL PERIODS OF RAIN WILL BE POSSIBLE DURING THE NEXT FEW DAYS AS A STATIONARY FRONT REMAINS OVER THE REGION. A FEW SHOWERS AND THUNDERSTORMS ARE EXPECTED WEDNESDAY MORNING BEFORE CLEARING OUT WEDNESDAY AFTERNOON. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED WEDNESDAY EVENING INTO THE OVERNIGHT HOURS. HIGHS WEDNESDAY WILL RANGE FROM THE MID 50S NORTH OF THE FRONT IN SOUTHERN MICHIGAN TO THE LOW 70S SOUTH OF THE FRONT SOUTH OF US 30. LOWS WEDNESDAY NIGHT WILL BE IN THE 50S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 419 AM EDT WED APR 8 2015 THE CLOUDY...COOL PATTERN CONTINUES AS WE MAINTAIN OUR POSITION NORTH OF THE STATIONARY FRONT. A WEAK SHORTWAVE HAS TRIGGERED SOME CONVECTION IN SE IOWA/ WESTERN ILLINOIS JUST NORTH OF THIS STATIONARY FRONT. THE STORMS SEEM TO BE STRUGGLING WITH EASTWARD EXTENT...LIKELY DUE TO A SLIGHTLY STRONGER CAP AT 650MB AND LESS INFLUENCE FROM THE MID LEVEL WAVE. GIVEN THE REMAINING UNCERTAINTY WITH THE EVOLUTION OF THIS CONVECTIVE COMPLEX AS IT MOVES EASTWARD...HAVE KEPT POPS IN THE HIGH CHANCE RANGE. EXPECT A LULL IN THE PRECIPITATION DURING THE AFTERNOON ON TODAY AS WEAK SHORTWAVE RIDGING BUILDS IN AHEAD OF THE NEXT SHORTWAVE TO EJECT OUT OF THE CENTRAL PLAINS. THIS WILL ALSO ALLOW FOR A LONG AWAITED SHIFT NORTHWARD IN THE FRONTAL BOUNDARY. THIS PSEUDO WARM FRONTAL SURGE WILL CREATE SIGNIFICANT BUST POTENTIAL FOR HIGH TEMPERATURES ON TODAY. AREAS SOUTH OF THE SURFACE FRONT WILL LIKELY WARM INTO THE LOW 70S WITH AREAS NORTH OF THE FRONT REMAINING IN THE MID 50S. THE EXACT PROGRESSION OF THIS FRONT NORTHWARD WILL DICTATE EXACTLY WHO SEES THE WARMER TEMPERATURES...BUT THE LATEST HIRES GUIDANCE PUTS THE MAX NORTHWARD PROGRESSION RIGHT ALONG US30. REGARDLESS OF THE EXACT PLACEMENT OF THIS FRONT...ITS PRESENCE ACROSS OUR AREA MEANS WE WILL BE FAVORABLE FOR THUNDERSTORM DEVELOPMENT DURING THE EVENING AND INTO THE OVERNIGHT HOURS. THERE IS SIGNIFICANT UNCERTAINTY WRT TIMING OF STORMS ACROSS THE AREA. NAM AND RAP HAVE A DECENT SHORTWAVE SPAWNING STORMS NORTH OF SAINT LOUIS DURING THE AFTERNOON AND MOVING THAT MCS THROUGH OUR AREA AROUND 00Z. ONLY GLOBAL GUIDANCE WHICH EVEN HINTS AT A WAVE MOVING THROUGH AT THAT TIME IS THE GEM AND THEREFORE GLOBAL GUIDANCE HOLDS OFF ON CONVECTION UNTIL AFTER MIDNIGHT. IR SATELLITE DOES SHOW SOME COOLER CLOUD TOPS IN SW KANSAS WHERE THIS SW IS CURRENTLY SUPPOSED TO BE...SO AM INCLINED TO BELIEVE THE HIRES GUIDANCE AND DISCOUNT THE GLOBAL GUIDANCE AS LACKING THE RESOLUTION TO PROPERLY RESOLVE THIS WAVE. SEVERE RISK DOES EXIST WITH ANY STORMS THAT DO DEVELOP IN THIS AFTERNOON TIMEFRAME GIVEN 40 TO 50 KNOTS OF DEEP LAYER SHEAR AND 1500 TO 2000 J/KG OF SBCAPE SOUTH OF THE SURFACE FRONT. EVEN IF THE EARLY EVENING STORM DEVELOPMENT ON THE HIRES GUIDANCE DOESN`T MATERIALIZE...THERE WILL STILL BE AN ISOLATED RISK OF SEVERE WEATHER DURING THE OVERNIGHT HOURS GIVEN THE ~2000 J/KG OF MUCAPE AND 30 KNOT LLJ WITH THE REMAINING PRESENCE OF 35 TO 45 KNOTS OF DEEP LAYER SHEAR. && .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 419 AM EDT WED APR 8 2015 PRIMARY CONCERNS FOR THE LONG TERM WILL CENTER ON CONVECTIVE/SEVERE POTENTIAL THURSDAY/THURSDAY NIGHT...FOLLOWED BY RENEWED PRECIP CHANCES EARLY NEXT WEEK. SHOWERS/STORMS WILL LIKELY BE ONGOING THURSDAY MORNING AS UPPER JET STREAK ASSOCIATED WITH SUBTROPICAL JET ENCROACHES ON THE OHIO RIVER VALLEY. AXIS OF 40-50 KNOT SOUTHWESTERLY LOW LEVEL FLOW NOSING INTO THE AREA BY MIDDAY WILL ALLOW FOR APPRECIABLE LOW/MID LEVEL MOISTURE ADVECTION. MOISTURE CONVERGENCE AT NOSE OF STRONGER LOW LEVEL FLOW SHOULD ALLOW POCKET OF PWATS NEAR 1.5 INCHES TO TRACK ACROSS FORECAST AREA THURSDAY MORNING WITH AMPLE ELEVATED MOISTURE FOR SHOWERS AND EMBEDDED THUNDER. POTENTIAL OF SOME LOCALLY HEAVIER RAINFALL AMOUNTS STILL APPEARS TO BE INTACT THROUGH THURSDAY MORNING IN ASSOCIATION WITH THIS FORCING ALONG WITH POTENTIAL OF SOME HAIL GIVEN ELEVATED INSTABILITY AND RELATIVELY LOW FREEZING/WBZ ZERO HEIGHTS BETWEEN 9-10K FT. SOME DEGREE OF UNCERTAINTY REMAINS REGARDING CONVECTIVE EVOLUTION THURSDAY AFTERNOON AND ASSOCIATED IMPACTS ON INSTABILITY MAGNITUDES DURING PEAK HEATING. ATTENTION FOR THURSDAY AFTERNOON/NIGHT WILL SHIFT UPSTREAM TO MORE ROBUST EASTERN PACIFIC WAVE WHICH SHOULD ACQUIRE NEGATIVE TILT ACROSS THE WESTERN GREAT LAKES THURSDAY EVENING. FRONTAL CONVERGENCE AND LEADING EDGE OF MID LEVEL DRY SLOT SHOULD REGENERATE POTENTIALLY VIGOROUS CONVECTIVE DEVELOPMENT ACROSS ILLINOIS DURING THE AFTERNOON...POSSIBLY TRACKING INTO WESTERN PORTIONS OF LOCAL AREA THURSDAY EVENING. EXTENT OF ANY THINNING CLOUD COVER THURSDAY AFTERNOON/LOW LEVEL TEMP TRENDS WILL HAVE A BIG IMPACT ON INSTABILITY MAGNITUDES. GIVEN STRENGTH OF BACKGROUND WIND FIELDS...A WIND THREAT MAY EVOLVE THURSDAY EVENING EVEN IF AFTERNOON INSTABILITY RECOVERY IS SOMEWHAT LIMITED. AS MENTIONED IN PREVIOUS FORECAST...A SOMEWHAT HIGHER SEVERE THREAT MAY UNFOLD IF GREATER LATE AFTERNOON INSTABILITY CAN BE REALIZED GIVEN SUBSTANTIAL SHEAR PROFILES...AND IN LIGHT OF DIFFERENTIAL MOISTURE ADVECTION IMMEDIATELY PRECEDING SFC FRONT THURSDAY NIGHT ASSOCIATED WITH THE DRY SLOT. SPC DAY2 OUTLOOK HAS MAINTAINED HIGHER SVR PROBS ACROSS WESTERN THIRD/HALF OF AREA...WITH POSSIBILITY OF WEAK NEAR SFC DIURNAL COOLING LATER THURSDAY EVENING DIMINISHING INSTABILITY MAGNITUDES A BIT ACROSS THE EAST. ONLY TWEAK TO PREVIOUS FORECAST WAS TO SLIGHTLY SPEED UP TIMING OF WEST TO EAST POP REDUCTION LATER THURSDAY NIGHT FOLLOWING COLD FRONT PROGRESSION. DID MAINTAIN SLIGHT CHANCE RAIN SHOWER POPS ACROSS THE FAR NORTH/FAR EAST EARLY FRIDAY MORNING GIVEN LINGERING MID/UPPER FORCING WITH A SERIES OF SMALLER SCALE WAVES ROTATING THROUGH LONGWAVE TROUGH...BUT ADDITIONAL PRECIP AMOUNTS ACROSS THESE LOCATIONS SHOULD BE QUITE LIGHT. BREEZY/WINDY CONDITIONS CAN ALSO BE EXPECTED WITH DEEPER POST FRONTAL MIXING LATE THURSDAY NIGHT INTO FRIDAY. IT STILL APPEARS AS THOUGH THE FRIDAY NIGHT THROUGH SUNDAY PERIOD SHOULD BE DRY WITH NEAR SEASONABLE TEMPS UNDER INFLUENCE OF MID/UPPER LEVEL RIDGING. LOW LEVEL ANTICYCLONE TO DEPART TO THE EAST SUNDAY NIGHT INTO MONDAY ALLOWING FOR A FAIRLY QUICK TRANSITION TO STRONGER LOW LEVEL MOISTURE TRANSPORT FOR MONDAY. GOOD MOISTURE AVAILABILITY AND APPROACH OF CUT-OFF SOUTHERN STREAM PV ANOMALY FOR TUE/WED SHOULD KEEP CHANCES OF SHOWERS AND STORMS GOING THROUGH THE END OF THE PERIOD AS THIS WAVE EVENTUALLY DAMPENS ACROSS THE AREA. THIS PATTERN WILL ALSO BE CONDUCIVE FOR SHARPLY MODERATING TEMPERATURES ONCE AGAIN FOR EARLY NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 128 AM EDT WED APR 8 2015 IFR CONDITIONS EXPECTED FOR A FEW MORE HOURS AT KSBN BEFORE LOWER ALT MIN CIGS ADVECT IN AFTER 10Z. THESE LOW CIGS WILL PERSIST AT BOTH TERMINALS THROUGH MID DAY WHEN A WARM FRONT WILL LIFT NORTHWARD INTO THE AREA. WINDS WILL QUICKLY SHIFT AROUND TO SOUTHWESTERLY SOUTH OF THIS FRONT AT KFWA AND WILL SWITCH TO NORTHWESTERLY AT KSBN AS A WEAK WAVE TRAVERSES THIS FRONT. THIS WAVE MAY BRING A FEW STORMS THROUGH THE AREA AROUND 00Z...BUT WILL WAIT FOR LATER TAF ISSUANCES TO INTRODUCE ANY TSRA MENTION. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR LMZ043-046. && $$ SYNOPSIS...BENTLEY SHORT TERM...BENTLEY LONG TERM...MARSILI AVIATION...BENTLEY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS WICHITA KS
401 PM CDT WED APR 8 2015 .MESOSCALE DISCUSSION... ISSUED AT 401 PM CDT WED APR 8 2015 THE INITIAL CONVECTION IS ABOUT TO EXIT THE FORECAST AREA. REGIONAL RADAR SHOWING THE FRONT BEGINNING TO RETREAT TO THE NORTH AND AT 2055Z WAS LOCATED FROM ANTHONY TO MULVANE TO EMPORIA. THE 20Z RAP SHOWS THE RETREAT OF THE FRONT VERY SLOWLY NORTHWARD. DO NOT THINK IT WILL GET CARRIED AWAY AND GO TOO FAR NORTH GIVEN THE STRENGTH OF THE COLD POOL. THROUGH 01Z...LOW LEVEL CAPE AND SHEAR WILL INCREASE...PRODUCING AN ENVIRONMENT THAT WILL FAVOR TORNADOES...SOME OF WHICH COULD BE SIGNIFICANT. CONVECTION IS ALREADY DEVELOPING OVER THE TEXAS PANHANDLE IN RESPONSE TO THE UPPER LEVEL DISTURBANCE MOVING INTO THE REGION. THIS WILL BE THE DISTURBANCE THAT LEADS TO TONIGHTS SIGNIFICANT SEVERE WEATHER THREAT. THINKING TONIGHT REMAINS ON TRACK. WHERE STORMS WILL BE ARE CONTINGENT TO THE LOCATION OF THE FRONT. WILL REMAIN VIGILANT IN TRACKING THIS. KRC && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 245 PM CDT WED APR 8 2015 THIS EVENING-TONIGHT: LATEST SURFACE ANALYSIS SHOWS MAIN SURFACE BOUNDARY LOCATED JUST TO THE SE OF ICT METRO...MAINLY FROM EUREKA TO MULVANE TO WELLINGTON. THE INITIAL ROUND OF CONVECTION HAS ALREADY BEGUN OVER SRN KS...WITH MULTICELL STORMS PRODUCING MAINLY HAIL AND DAMAGING WINDS. THIS INITIAL ROUND OF STORMS WILL STAY IN THE WARM SECTOR ACROSS SE KS FOR THE EARLY AFTERNOON HOURS. WITH THE MAIN CONCERN FROM THIS ROUND BEING LARGE HAIL AND DAMAGING WINDS GIVEN THE UNSTABLE AIRMASS AND FAVORABLE BULK SHEAR. LATEST SHORT TERM HI-RES MODELS CONTINUE TO SHOW THE BOUNDARY RETROGRADING BACK TO THE NORTH EARLY THIS EVENING BETWEEN 21Z-02Z... WITH A SIGNIFICANT INCREASE OF LOW LEVEL CAPE BACK TOWARDS THE KICT METRO. THIS IN CONJUNCTION WITH THE INCREASE IN BULK SHEAR FROM THE INCOMING DISTURBANCE COUPLED WITH THE LOW LEVEL JET WILL PRODUCE A SCENARIO VERY FAVORABLE FOR TORNADIC SUPERCELLS TO DEVELOP ALONG THE DRY LINE AS IT SHARPENS FOR AREAS TO THE WEST AND SW OF SOUTH CENTRAL KS. THIS WILL LEAD TO A SECOND POSSIBLY MORE SIGNIFICANT CHANCE OF STORMS FOR LATER THIS EVENING WELL AFTER DARK. LATEST HI- RES MODEL CONTINUE TO SHOW 0-8KM SHEAR IS VERY FAVORABLE FOR SUPERCELLS AND POSSIBLE LONG TRACK TORNADOES. INCREASED MLCAPE TO 2000-2500 J/KG AND LOWERING LCL LEVELS WOULD ALSO SUGGEST A STRONG TORNADO THREAT AS WELL. SO THIS SETUP WOULD STILL LEAD TO HIGH LIKELYHOOD OF THE TORNADO THREAT CONTINUING WELL AFTER DARK FOR AREAS AREAS ACROSS SOUTH CENTRAL KS...MAINLY ALONG OR SOUTH OF HIGHWAY 54/400. EXPECT THE SEVERE CONVECTION TO CONTINUE FOR THE OVERNIGHT HOURS...WITH PROGRESSION OF THE STORMS TO THE EAST INTO THE FLINT HILLS AND SOUTHEAST KS. DEEP LAYER SHEAR LOOKS TO WANE SOME AFTER MIDNIGHT...WHICH WILL LIKELY SHIFT THE SEVERE WEATHER MODE TO MORE OF A LARGE HAIL AND DAMAGING WIND CHANCE. THU: COULD SEE SOME LINGERING STORMS ACROSS PORTIONS OF SOUTHEAST KS IN THE MORNING HOURS AS THE DRY LINE/BOUNDARY SURGES EAST INTO WRN MO. IT NOT COMPLETELY OUT OF THE REALM OF POSSIBILITY THAT SOME LINGERING STRONG STORMS WILL BE OVER SE KS...BUT THIS CHANCE WILL BE SHORT LIVED. EXPECT THE THU AFTERNOON SEVERE THREAT TO OVER EXTREME SE KS AND MAINLY IN SW MO. WITH THE REST OF THE REGION SEEING NICE WEATHER RETURN TO THE AREA...WITH DRIER AIR MOVING INTO THE AREA. FRI-EARLY SAT: A COUPLE OF NICE DAY EXPECTED FOR FRI AND EARLY SAT AS A LARGE AREA OF HIGH PRESSURE MOVES ACROSS THE PLAINS INTO THE SRN PLAINS. THIS WILL LEAD TO NEAR SEASONAL TEMPS AND SUNNY SKIES IN MOST LOCATIONS. AS SATURDAY PROGRESSES...LOW LEVEL MOISTURE WILL RAPIDLY RETURN TO THE AREA FOR AREAS WEST OF THE FORECAST AREA FOR SAT AFTERNOON. COULD SEE SHOWERS AND THUNDERSTORMS DEVELOP TO THE WEST OF THE AREA AND POSSIBLY MOVE INTO SOME OF THE WRN PORTIONS OF COUNTY WARNING AREA BY SAT EVENING. SAT NIGHT: ISENTROPIC LIFT AND MOISTURE RETURN WILL CONTINUE OVER THE WRN HALF OF THE FORECAST AREA FOR SAT NIGHT. THIS MAY LEAD TO A CHANCE OF SHOWERS AND THUNDERSTORM COVERAGE INCREASING ACROSS MOST OF THE AREA FOR SAT NIGHT. KETCHAM .LONG TERM...(SUNDAY THROUGH WEDNESDAY) ISSUED AT 245 PM CDT WED APR 8 2015 MEDIUM RANGE MODELS DO DIFFER SOME ON HOW SUN AND MON WILL PLAY OUT. BUT BOT MODELS SUGGEST ANOTHER CHANCE OF THUNDERSTORMS ON SUNDAY...WITH POSSIBLE STRONG TO SEVERE STORMS. THE ECMWF LOOKS TO CLEAR THINGS OUT ON MON...WHILE THE GFS SUGGESTS A BOUNDARY MAY BE STATIONARY ACROSS SRN KS FOR MON. KETCHAM && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1208 PM CDT WED APR 8 2015 CONVECTION NOW DEVELOPING OVER OKLAHOMA WILL MOVE NORTHEAST INTO THE AIRSPACE AND CONTINUE WITH SEVERAL ROUNDS THROUGH 6Z. THIS WILL AFFECT ALL AIRPORTS AND FIELDS ALONG AND SOUTHEAST OF KSLN- KVNX. THESE STORMS WILL BE SEVERE AND SHOULD BE AVOIDED. FOG...WHICH CONTINUES TO AFFECT KHUT...KRSL...KSLN HAS BEEN SLOW TO BURN OFF. THINK IT SHOULD BE GONE BY 21Z. VFR CONDITIONS SHOULD PERSIST THROUGH 03Z...WITH FOG REDEVELOPMENT THERE POSSIBLE THROUGH 12Z. THE COLD FRONT WILL CLEAR THE AREA BY 14Z. && .FIRE WEATHER... ISSUED AT 245 PM CDT WED APR 8 2015 MAIN FIRE WEATHER CONCERNS LOOK TO ON THURSDAY. EVEN WITH PLENTY OF LOW LEVEL MOISTURE...VERY HIGH FIRE DANGER WILL BE IN PLACE OVER SOUTH CENTRAL AND SE KS DUE TO GUSTY SOUTH WINDS. HOWEVER...THE CRITICAL FIRE WEATHER DAY LOOKS TO BE THU. THIS IS WHEN STRONG NW WINDS WILL BE IN PLACE BY THE AFTERNOON HOURS ALONG WITH RH`S IN THE 35-45 PERCENT RANGE. WIND SPEEDS THU AFTERNOON WILL BE IN THE 20-30 MPH RANGE WITH HIGHER GUSTS. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 56 71 39 68 / 30 10 0 0 HUTCHINSON 52 67 37 68 / 30 10 0 0 NEWTON 54 67 38 67 / 30 10 0 0 ELDORADO 60 69 39 68 / 40 10 10 0 WINFIELD-KWLD 61 72 40 68 / 30 10 0 0 RUSSELL 46 63 35 67 / 20 10 10 0 GREAT BEND 46 64 35 67 / 10 10 0 0 SALINA 50 65 35 68 / 30 20 10 0 MCPHERSON 51 66 36 67 / 30 10 10 0 COFFEYVILLE 65 76 42 68 / 40 30 10 0 CHANUTE 64 73 41 68 / 50 30 10 0 IOLA 63 72 40 67 / 50 30 10 0 PARSONS-KPPF 64 74 41 68 / 50 30 10 0 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
348 PM CDT WED APR 8 2015 ...UPDATED FOR LONG TERM DISCUSSION... .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 150 PM CDT WED APR 8 2015 A SURFACE BOUNDARY WILL SLOWLY LIFT NORTH INTO EXTREME SOUTHERN KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. A DRYLINE WILL EXTEND SOUTH OF THIS BOUNDARY ACROSS BARBER COUNTY INTO NORTHERN OKLAHOMA. GIVEN THE INSTABILITY EXPECTED AHEAD OF AN UPPER LEVEL DISTURBANCE WHICH WILL BE CROSSING CENTRAL KANSAS LATE THIS AFTERNOON THERE WILL BE A CHANCE FOR SOME CONVECTION TO DEVELOP ALONG EITHER SURFACE BOUNDARY. BASED ON THE 0-6KM SHEAR FORECAST AT 00Z THURSDAY ANY STORM THAT MAY DEVELOP IN THIS AREA SHOULD RAPIDLY DEVELOP AND MAY BECOME SEVERE BEFORE IT MOVES EAST OF PRATT AND BARBER COUNTY. AT THIS TIME THE MAIN HAZARD LATE TODAY WILL BE 2 INCH HAIL AND STRONG GUSTY WINDS. FURTHER WEST CLEAR SKIES, WARM TEMPERATURES, AND DEWPOINTS IN THE 30S HAVE RESULT IN RELATIVE HUMIDITY VALUES FALLING BACK INTO THE TEENS AT 00F 18Z. GIVEN THAT THE CLEARING TREND CURRENTLY OCCURRING WILL CONTINUE, BASED ON SATELLITE LOOP, AND THE 850MB MIX DOWN TEMPERATURES AT 00Z THURSDAY IT APPEARS THAT CRITICAL FIRE WEATHER CONDITIONS WILL STILL EXIST LATE TODAY. AS A RESULT WILL LEAVE THE CURRENT RED FLAG WARNING GOING FOR PORTIONS OF SOUTHWEST KANSAS. FOR THE REMAINDER OF THE OVERNIGHT PERIOD...THE SURFACE BOUNDARY, WHICH WAS LOCATED OVER SOUTHWEST KANSAS LATE THIS AFTERNOON/EARLY EVENING, WILL MOVE SOUTH AS AN UPPER LEVEL TROUGH CROSSES THE CENTRAL HIGH PLAINS. BASED ON THE SURFACE DEW POINTS EXPECTED EARLY THURSDAY MORNING, SOME MID OR HIGH CLOUDS PRECEDING THE UPPER LEVEL TROUGH, AND A DEVELOPING NORTHWESTERLY FLOW THE PREVIOUS FORECAST STILL APPEARS ON TRACK WITH LOWS BOTTOMING OUT MAINLY IN THE 40S ACROSS WESTERN KANSAS. LOWS IN THE 50 TO NEAR 55 DEGREE RANGE WILL BE LIKELY ACROSS SOUTH CENTRAL KANSAS. THE UPPER LEVEL TROUGH WILL CROSS WESTERN KANSAS EARLY THURSDAY MORNING AS A SURFACE HIGHS BEGINS TO BUILD INTO NORTHWESTERN KANSAS/NORTHEAST COLORADO. OVER WESTERN KANSAS GUSTY NORTHWEST WINDS AT 20 TO NEAR 30 MPH ARE EXPECTED BY THE EARLY AFTERNOON BASED ON 0-1KM WINDS RANGING FROM 25 TO NEAR 35 KNOTS, AND THE MEAN MIXED LAYER WINDS AT 18Z AND 21Z RANGING FROM 30 TO 35KNOTS. BASED ON THE MIXING POTENTIAL THURSDAY AFTERNOON FROM THE BUFR NAM, AND THE 850MB TEMPERATURES AT 00Z FRIDAY WILL TREND TOWARDS THE WARMER GUIDANCE ACROSS WESTERN KANSAS. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 327 PM CDT WED APR 8 2015 COOL, SURFACE HIGH PRESSURE WILL BUILD INTO WESTERN KANSAS THROUGH FRIDAY. WITH LIGHT WINDS THURSDAY NIGHT, TEMPERATURES WILL FALL INTO THE 30S, WITH SOME READINGS CLOSE TO FREEZING FROM DODGE CITY WESTWARD AND NORTHWARD. HIGHS WILL BE IN THE 60S FRIDAY. THE MODELS, ESPECIALLY THE ECMWF/GFS, ARE INDICATING A SHORTWAVE TROUGH OVER THE DESERT SOUTHWEST PROGRESSING INTO THE SOUTHERN HIGH PLAINS IN NEGATIVE TILT FASHION BY SUNDAY BEFORE CLOSING OFF OVER THE SOUTHERN PLAINS BY MONDAY. THE GEM IS FATHER SOUTH WITH THE UPPER LOW, WITH LESS PRECIPITATION OVER WESTERN KANSAS. WITH PLENTY OF LOW LEVEL MOISTURE IN PLACE, CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS ARE GOOD ON MONDAY. AHEAD OF THIS SYSTEM, A FEW SHOWERS AND STORMS ARE POSSIBLE SATURDAY AFTERNOON AND NIGHT ALONG THE LEE TROUGH AS WELL BUT WITH LIMITED INSTABILITY, . HIGH TEMPERATURES WILL GENERALLY BE MILD, BUT MAY BE HELD DOWN MONDAY DUE TO CLOUDS AND PRECIPITATION. OVERNIGHT LOWS WILL OF COURSE BE INCREASING THROUGH MONDAY DUE TO THE LEE TROUGHING, SOUTH WINDS AND HIGHER DEWPOINTS. A MORE AMPLIFIED UPPER LEVEL TROUGH WILL BEGIN TO DEVELOP OVER THE WESTERN UNITED STATES MONDAY THROUGH WEDNESDAY OF NEXT WEEK, RESULTING IN LEE TROUGHING, SOUTHERLY WINDS AND WARMER TEMPERATURES TUESDAY. GIVEN A POSITIVE TILT TO THIS UPPER LEVEL SYSTEM AS DEPICTED IN THE MODELS, SEVERE WEATHER CHANCES MAY BE HIGHER ACROSS EASTERN KANSAS DUE TO MORE VEERED LOW LEVEL WINDS, WITH SOME CHANCES FOR SHOWERS AND THUNDERSTORMS BY THE MIDDLE OF NEXT WEEK OVER WESTERN KANSAS AS THE COLD FRONT APPROACHES. BEHIND THIS FRONT, MUCH COOLER WEATHER IS POSSIBLE BY LATE NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1215 PM CDT WED APR 8 2015 STATUS AND FOG WILL ERODE THIS AFTERNOON AS A SURFACE BOUNDARY BEGINS TO SLOWLY MOVE NORTH ACROSS SOUTHWEST KANSAS. AT THIS TIME BASED ON THE LATEST TRENDS FROM THE HRRR AND RAP WILL GRADUALLY IMPROVE CEILING WITH VFR CONDITIONS DEVELOPING BETWEEN 20Z AND 22Z AT DDC AND GCK. HYS WILL IMPROVE TO MVFR. VFR CONDITIONS AT HYS IS EXPECTED TO DEVELOP TOWARDS 00Z THURSDAY. THE PREVAILING WIND THIS AFTERNOON NORTH OF THIS FRONT WILL BE NORTHERLY AT 10 KNOTS OR LESS. NORTHWEST WINDS WILL DEVELOP OVERNIGHT AS A COLD FRONT CROSSES WESTERN KANSAS. THE NORTHWESTERLY WINDS WILL INCREASE BY LATE MORNING THURSDAY AS STRONGER BOUNDARY LAYER WINDS MIXED DOWN TO THE SURFACE. && .PRELIMINARY POINT TEMPS/POPS... DDC 46 66 35 67 / 10 10 0 0 GCK 42 64 34 68 / 10 10 0 0 EHA 42 65 35 68 / 10 10 0 0 LBL 44 67 36 68 / 20 10 0 0 HYS 45 62 34 67 / 20 10 0 0 P28 53 72 38 69 / 20 10 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR KSZ084>086. && $$ SHORT TERM...BURGERT LONG TERM...FINCH AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
156 PM CDT WED APR 8 2015 ...UPDATED SHORT TERM DISCUSSION... .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 150 PM CDT WED APR 8 2015 A SURFACE BOUNDARY WILL SLOWLY LIFT NORTH INTO EXTREME SOUTHERN KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. A DRYLINE WILL EXTEND SOUTH OF THIS BOUNDARY ACROSS BARBER COUNTY INTO NORTHERN OKLAHOMA. GIVEN THE INSTABILITY EXPECTED AHEAD OF AN UPPER LEVEL DISTURBANCE WHICH WILL BE CROSSING CENTRAL KANSAS LATE THIS AFTERNOON THERE WILL BE A CHANCE FOR SOME CONVECTION TO DEVELOP ALONG EITHER SURFACE BOUNDARY. BASED ON THE 0-6KM SHEAR FORECAST AT 00Z THURSDAY ANY STORM THAT MAY DEVELOP IN THIS AREA SHOULD RAPIDLY DEVELOP AND MAY BECOME SEVERE BEFORE IT MOVES EAST OF PRATT AND BARBER COUNTY. AT THIS TIME THE MAIN HAZARD LATE TODAY WILL BE 2 INCH HAIL AND STRONG GUSTY WINDS. FURTHER WEST CLEAR SKIES, WARM TEMPERATURES, AND DEWPOINTS IN THE 30S HAVE RESULT IN RELATIVE HUMIDITY VALUES FALLING BACK INTO THE TEENS AT 00F 18Z. GIVEN THAT THE CLEARING TREND CURRENTLY OCCURRING WILL CONTINUE, BASED ON SATELLITE LOOP, AND THE 850MB MIX DOWN TEMPERATURES AT 00Z THURSDAY IT APPEARS THAT CRITICAL FIRE WEATHER CONDITIONS WILL STILL EXIST LATE TODAY. AS A RESULT WILL LEAVE THE CURRENT RED FLAG WARNING GOING FOR PORTIONS OF SOUTHWEST KANSAS. FOR THE REMAINDER OF THE OVERNIGHT PERIOD...THE SURFACE BOUNDARY, WHICH WAS LOCATED OVER SOUTHWEST KANSAS LATE THIS AFTERNOON/EARLY EVENING, WILL MOVE SOUTH AS AN UPPER LEVEL TROUGH CROSSES THE CENTRAL HIGH PLAINS. BASED ON THE SURFACE DEW POINTS EXPECTED EARLY THURSDAY MORNING, SOME MID OR HIGH CLOUDS PRECEDING THE UPPER LEVEL TROUGH, AND A DEVELOPING NORTHWESTERLY FLOW THE PREVIOUS FORECAST STILL APPEARS ON TRACK WITH LOWS BOTTOMING OUT MAINLY IN THE 40S ACROSS WESTERN KANSAS. LOWS IN THE 50 TO NEAR 55 DEGREE RANGE WILL BE LIKELY ACROSS SOUTH CENTRAL KANSAS. THE UPPER LEVEL TROUGH WILL CROSS WESTERN KANSAS EARLY THURSDAY MORNING AS A SURFACE HIGHS BEGINS TO BUILD INTO NORTHWESTERN KANSAS/NORTHEAST COLORADO. OVER WESTERN KANSAS GUSTY NORTHWEST WINDS AT 20 TO NEAR 30 MPH ARE EXPECTED BY THE EARLY AFTERNOON BASED ON 0-1KM WINDS RANGING FROM 25 TO NEAR 35 KNOTS, AND THE MEAN MIXED LAYER WINDS AT 18Z AND 21Z RANGING FROM 30 TO 35KNOTS. BASED ON THE MIXING POTENTIAL THURSDAY AFTERNOON FROM THE BUFR NAM, AND THE 850MB TEMPERATURES AT 00Z FRIDAY WILL TREND TOWARDS THE WARMER GUIDANCE ACROSS WESTERN KANSAS. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 256 AM CDT WED APR 8 2015 THE UPPER LEVEL SHORTWAVE WILL MOVE OUT OF THE HIGH PLAINS THURSDAY WITH A WEAK UPPER LEVEL RIDGE BUILDING OVER THE ROCKIES AND PLAINS THURSDAY NIGHT THROUGH FRIDAY NIGHT. CLOUDS ARE EXPECTED TO DECREASE IN COVERAGE OVER NORTHERN KANSAS THURSDAY WITH MOSTLY CLEAR SKIES ANTICIPATED THERE AND ELSEWHERE THROUGH FRIDAY. TOWARDS THE SURFACE, A DOME OF HIGH PRESSURE WILL BUILD INTO THE AREA BEHIND THE PREVIOUS SYSTEM LEADING TO NORTH TO NORTHWEST WINDS ACROSS WESTERN KANSAS. THE CENTER OF HIGH PRESSURE MOVES EAST OF THE AREA BY FRIDAY SHIFTING WINDS BACK TO MORE OF A SOUTHERLY DIRECTION. SOUTHERLY WINDS CONTINUE FRIDAY NIGHT WITH A SLIGHT INCREASE IN HIGH CLOUDS AS THE NEXT SYSTEM, ELABORATED ABOUT BELOW, APPROACHES. ATTENTION THEN FOCUSES ON THE WEEKEND AS AN UPPER LEVEL SHORTWAVE INTENSIFIES ABOVE THE DESERT SOUTHWEST THEN TRACKS EASTWARD ACROSS THE SOUTHERN ROCKIES BEFORE CURLING NORTHWARD INTO THE PLAINS. TOWARDS THE SURFACE, THE AFOREMENTIONED DOME OF HIGH PRESSURE WILL CONTINUE TO SHIFT EASTWARD AS THIS FEATURE APPROACHES ALLOWING GULF MOISTURE TO BE PUSHED NORTH INTO THE PLAINS. A FEW THUNDERSTORMS WILL BE POSSIBLE OVER THE WEEKEND WITH INCREASED CLOUD COVER. A QUIET PATTERN THEN RETURNS EARLY NEXT WEEK AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE SOUTHWEST UNITED STATES. AS FOR TEMPERATURES, HIGHS WILL GENERALLY BE IN THE 60S THURSDAY AND FRIDAY WITH LOWS IN THE 30S THURSDAY NIGHT AND IN THE MID 40S FRIDAY NIGHT. HIGHS THEN REBOUND INTO THE 70S SATURDAY WITH CLOSER TO 80 DEGREES EXPECTED ON SUNDAY. LOWS DURING THIS TIME FRAME WILL GENERALLY RANGE FROM THE MID 40S TO MID 50S. HIGHS DURING THE BEGINNING OF NEXT WEEK LOOK TO BE IN THE 70S WITH LOWS CONTINUING TO RANGE FROM THE MID 40S TO MID 50S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1215 PM CDT WED APR 8 2015 STATUS AND FOG WILL ERODE THIS AFTERNOON AS A SURFACE BOUNDARY BEGINS TO SLOWLY MOVE NORTH ACROSS SOUTHWEST KANSAS. AT THIS TIME BASED ON THE LATEST TRENDS FROM THE HRRR AND RAP WILL GRADUALLY IMPROVE CEILING WITH VFR CONDITIONS DEVELOPING BETWEEN 20Z AND 22Z AT DDC AND GCK. HYS WILL IMPROVE TO MVFR. VFR CONDITIONS AT HYS IS EXPECTED TO DEVELOP TOWARDS 00Z THURSDAY. THE PREVAILING WIND THIS AFTERNOON NORTH OF THIS FRONT WILL BE NORTHERLY AT 10 KNOTS OR LESS. NORTHWEST WINDS WILL DEVELOP OVERNIGHT AS A COLD FRONT CROSSES WESTERN KANSAS. THE NORTHWESTERLY WINDS WILL INCREASE BY LATE MORNING THURSDAY AS STRONGER BOUNDARY LAYER WINDS MIXED DOWN TO THE SURFACE. && .PRELIMINARY POINT TEMPS/POPS... DDC 46 66 35 67 / 10 10 0 0 GCK 42 64 34 68 / 10 10 0 0 EHA 42 65 35 68 / 10 10 0 0 LBL 44 67 36 68 / 0 10 0 0 HYS 45 62 34 67 / 20 10 0 0 P28 53 72 38 69 / 10 10 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR KSZ061-062-074>076-084>088. && $$ SHORT TERM...BURGERT AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS WICHITA KS
1243 PM CDT WED APR 8 2015 .MESOSCALE DISCUSSION... ISSUED AT 1245 PM CDT WED APR 8 2015 FRONT NOW DRIFTING SOUTHEAST AND IS LOCATED FROM KK68-KWDG. INSPECTION OGT HE WSR-88D DATA SHOWS THE FRONT FROM ROSALIA- MULVANE-BLUFF CITY. INFLECTION POINT SEEMS TO HAVE DEVELOPED NEAR MULVANE. FIRST ROUND OF CONVECTION NOW MOVING ACROSS NORTHERN OKLAHOMA AND INCREASING IN INTENSITY. THE LATEST HRRR/RAP RUNS SHOW THIS WELL AND BRING CONVECTION NORTHEAST FROM THAT LOCATION. THE MAIN THREAT CONTINUES TO BE LARGE HAIL AND WIND DAMAGE. THE LARGE HAIL PARAMETER DOES SUGGEST SIGNIFICANT HAIL POTENTIAL. THE RAP CONTINUES TO SHOW A RETROGRADING BOUNDARY WITH A SIGNIFICANT INCREASE OF LOW LEVEL CAPE. THIS IN CONJUNCTION WITH THE INCREASE IN SHEAR FROM THE INCOMING DISTURBANCE COUPLED WITH THE LOW LEVEL JET WILL PRODUCE A SCENARIO VERY FAVORABLE FOR TORNADIC SUPERCELLS. WHAT HAS BEEN CONSISTENT HAS BEEN THE CONTINUED FOCUS ON AN AREA THAT INCLUDES COWLEY...SUMNER...AND SOUTHERN BUTLER COUNTIES WHERE THESE SIGNIFICANT INGREDIENTS ALL COME TOGETHER. THIS IS ONLY NWP GUIDANCE...BUT THE CONSISTENCY HAS REMAINED AND IS WORTH MENTIONING. MOREOVER...THE RAP CONTINUES TO SHOW A HIGH LIKELIHOOD OF TORNADOES CONTINUING AFTER DARK. PRETTY GOOD CONFIDENCE IN THIS SCENARIO. KRC && .SYNOPSIS... ISSUED AT 332 AM CDT WED APR 8 2015 WATER VAPOR IMAGERY SHOWS A STRONG SHORTWAVE TRACKING OVER THE CENTRAL GREAT BASIN. AT THE SURFACE...LOW PRESSURE IS SITUATED OVER SE CO WITH THE SYNOPTIC FRONT STRETCHING FROM JUST NORTH OF KGAG TO BETWEEN KCNU AND KPPF. MEANWHILE...A LOSE DRYLINE EXTENDS ACROSS THE OK PANHANDLE AND INTO WEST TX. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 332 AM CDT WED APR 8 2015 ELEVATED STORMS DEVELOPED A COUPLE HOURS AGO OVER THE FLINT HILLS IN RESPONSE TO A RAPID INCREASE IN MOISTURE TRANSPORT IN THE 850-700MB LAYER. THIS ACTIVITY SHOULD FOR THE MOST PART STAY NORTHEAST OF THE FORECAST AREA. SIGNIFICANT SEVERE STORMS STILL LOOK LIKELY THIS AFTERNOON AND EVENING. CURRENTLY HAVE A LEAN TO THE RAP13 DUE TO ITS PERFORMANCE WITH THE CONVECTION THAT OCCURRED OVER THE LAST SEVERAL HOURS OVER SE KS. IN ADDITION...IT SEEMS TO BE DOING A DECENT JOB CAPTURING THE CURRENT ELEVATED CONVECTION. THE GFS LIFTS THE WARM FRONT MUCH FURTHER NORTH COMPARED TO THE NAM AND RAP WITH THE FRONT ALONG I-70. MEANWHILE THE RAP AND NAM LIFT THE FRONT TO JUST NORTH OF KICT TO SOUTH OF KSLN. CURRENT THINKING IS THAT THE TRIPLE POINT BY LATE AFTERNOON WILL BE SITUATED JUST SOUTHWEST OF THE FORECAST AREA NEAR OR JUST NORTH OF KGAG WITH THE SYNOPTIC FRONT EXTENDING TO THE NORTHEAST NEAR KICT AND THEN TO NEAR KEMP. WATER VAPOR IMAGERY SHOWS A LEAD IMPULSE/JET MAX OVER NORTHERN BAJA. EXPECTING STORMS TO DEVELOP NEAR THE TRIPLE POINT AS THIS FEATURE MOVES OUT OF THE SOUTHERN HIGH PLAINS. ADDITIONAL DEVELOPMENT CAN THEN BE EXPECTED NORTHEAST ALONG THE SYNOPTIC FRONT. IT SEEMS WITH EACH MODEL RUN THE DEEP LAYER SHEAR HAS INCREASED SLIGHTLY AND THE 00Z RUNS WERE NO EXCEPTION...WITH AROUND 50KTS OF 0-6KM SHEAR AND 65-80KTS OF 0-8KM SHEAR OVER SOUTH CENTRAL KS. THESE SHEAR VALUES WILL COMBINE WITH 2000-3000J/KG OF CAPE TO ALLOW ANY STORM THAT DEVELOPS TO QUICKLY BECOME SEVERE. THE SCARY PART IS THAT WITH THE RETREATING DRYLINE AFTER 00Z...THE ENVIRONMENT ACTUALLY BECOMES MORE FAVORABLE AFTER DARK AS WINDS BACK AND THE LOW LEVEL JET GETS GOING. SO NOT OUT OF THE QUESTION TO GET A TORNADO AFTER DARK OVER SOUTH CENTRAL KS. THE BEST TORNADO POTENTIAL TONIGHT LOOKS TO BE SOUTH OF HIGHWAY 50 AND WEST OF HIGHWAY 99. IF THE NAM AND RAP13 VERIFIES...SEVERE STORMS OVER CENTRAL KS WOULD BE LESS LIKELY. BY 12Z THU...THE SHORTWAVE WILL BE TRACKING ACROSS NORTHERN KS/NEBRASKA WITH THE SYNOPTIC FRONT CATCHING UP TO THE DRYLINE AND SURGING EAST. WHILE THERE MAYBE SOME REMNANT STORMS OVER SE KS AROUND SUNRISE...THE BULK OF THE ACTIVITY AFTER 15Z THU WILL BE EAST OF THE FORECAST AREA. IT NOW LOOKS LIKE THE BETTER CHANCES FOR PRECIP ON THE BACKSIDE OF THIS SYSTEM SHOULD STAY NORTH OF THE FORECAST AREA THU. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 332 AM CDT WED APR 8 2015 A LARGE AREA OF HIGH PRESSURE WILL ENCOMPASS THE PLAINS FOR FRI WITH TEMPS FINALLY GETTING BACK TO SEASONAL VALUES. BOTH THE GFS AND ECMWF BRING A SOUTHERN STREAM SYSTEM OUT OF THE BAJA REGION AND INTO WEST TX BY SUN EVENING. WARM ADVECTION AHEAD OF THIS SYSTEM MAY BRING SOME SCATTERED SHOWERS AND STORMS SAT BUT THE BETTER PRECIP CHANCES LOOK TO ARRIVE SUN NIGHT AND CONTINUE THROUGH MON WHEN THE IMPULSE LIFTS ACROSS THE PLAINS. THE GFS HAS THIS FEATURE QUITE A BIT FURTHER WEST COMPARED TO THE ECMWF WHICH RESULTS IN THE ECMWF BEING THE WETTER SOLUTION. LAWSON && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1208 PM CDT WED APR 8 2015 CONVECTION NOW DEVELOPING OVER OKLAHOMA WILL MOVE NORTHEAST INTO THE AIRSPACE AND CONTINUE WITH SEVERAL ROUNDS THROUGH 6Z. THIS WILL AFFECT ALL AIRPORTS AND FIELDS ALONG AND SOUTHEAST OF KSLN- KVNX. THESE STORMS WILL BE SEVERE AND SHOULD BE AVOIDED. FOG...WHICH CONTINUES TO AFFECT KHUT...KRSL...KSLN HAS BEEN SLOW TO BURN OFF. THINK IT SHOULD BE GONE BY 21Z. VFR CONDITIONS SHOULD PERSIST THROUGH 03Z...WITH FOG REDEVELOPMENT THERE POSSIBLE THROUGH 12Z. THE COLD FRONT WILL CLEAR THE AREA BY 14Z. && .FIRE WEATHER... ISSUED AT 332 AM CDT WED APR 8 2015 MAIN FIRE WEATHER CONCERNS LOOK TO ON THURSDAY. EVEN WITH PLENTY OF LOW LEVEL MOISTURE...VERY HIGH FIRE DANGER WILL BE IN PLACE OVER SOUTH CENTRAL AND SE KS DUE TO GUSTY SOUTH WINDS. HOWEVER...THE CRITICAL FIRE WEATHER DAY LOOKS TO BE THU. THIS IS WHEN STRONG NW WINDS WILL BE IN PLACE BY THE AFTERNOON HOURS ALONG WITH RH`S IN THE 35-45% RANGE. WIND SPEEDS THU AFTERNOON WILL BE IN THE 20-30 MPH RANGE WITH HIGHER GUSTS. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 83 56 71 38 / 30 30 10 0 HUTCHINSON 75 52 67 37 / 30 20 10 0 NEWTON 77 54 67 38 / 40 30 10 0 ELDORADO 83 60 69 40 / 40 40 10 10 WINFIELD-KWLD 85 61 72 41 / 40 30 10 0 RUSSELL 64 46 63 35 / 20 20 10 10 GREAT BEND 69 46 64 35 / 20 10 10 0 SALINA 67 50 65 35 / 30 30 20 10 MCPHERSON 70 51 66 36 / 30 30 10 10 COFFEYVILLE 82 65 76 43 / 40 40 30 10 CHANUTE 78 64 73 41 / 40 50 30 10 IOLA 78 63 72 40 / 40 50 30 10 PARSONS-KPPF 81 64 74 42 / 40 50 30 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1217 PM CDT WED APR 8 2015 ...UPDATED AVIATION DISCUSSION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM CDT WED APR 8 2015 MAIN CONCERNS WITH THIS PART OF THE FORECAST CENTER AROUND DENSE FOG POTENTIAL THIS MORNING AND THEN RED FLAG CONDITIONS OVER FAR SOUTHWEST KANSAS AND SEVERE STORM POTENTIAL OVER SOUTH CENTRAL KANSAS THIS AFTERNOON AND EARLY EVENING. A STATIONARY FRONT CONTINUED TO EXTEND FROM THE FRONT RANGE OF CENTRAL COLORADO ACROSS THE FAR SOUTHWEST CORNER OF KANSAS INTO NORTHERN OKLAHOMA AND BACK NORTHEAST ACROSS THE SOUTHEAST PART OF KANSAS INTO MISSOURI. A SURGE OF EASTERLY UPSLOPE FLOW TO THE NORTH OF THE FRONT HAS RESULTED IN STRATUS SURGING BACK SOUTH ACROSS WESTERN KANSAS OVERNIGHT. WIDESPREAD LIGHT FOG WAS ALSO DEVELOPING ALONG WITH SOME PATCHY DRIZZLE OVER NORTHWEST AND WEST CENTRAL KANSAS. MODEL SOUNDINGS SHOW THE SATURATED BOUNDARY LAYER THE DEEPEST OVER CENTRAL KANSAS ALONG I-70 WITH THE LAYER BECOMING MORE SHALLOW OUT NEAR THE COLORADO AND OKLAHOMA BORDERS. WILL KEEP A MENTION OF FOG AND DRIZZLE OVER MUCH OF THE AREA GENERALLY NORTH OF HIGHWAY 50 EARLY THIS MORNING ALTHOUGH THE BEST POTENTIAL FOR ANY DRIZZLE WILL BE ALONG I-70. SHORT TERM MESOSCALE MODELS HAVE BEEN TRENDING TOWARD AN AREA OF DENSE FOG DEVELOPING OVER FAR SOUTHWEST KANSAS INTO EAST CENTRAL COLORADO EARLY THIS MORNING. WHILE A FEW POCKETS OF DENSE FOG HAD DEVELOPED EARLIER IN NORTHWEST KANSAS, IT DOES NOT APPEAR TO BE A SOLID TREND IN THAT DIRECTION YET. FOR NOW WILL HOLD OFF ON ANY DENSE FOG HEADLINES BUT WILL CONTINUE TO SHOW FOG WITH 1/2 MILE VISIBILITY REDUCTIONS IN THE FAR SOUTHWEST. CONDITIONS WILL BEGIN TO IMPROVE AFTER SUNRISE WITH THE FOG AND STRATUS DISSIPATING FROM SOUTH TO NORTH DURING THE DAY. HAYS WILL BE THE LAST TO CLEAR OUT WITH SOME SUN POSSIBLE BY LATE AFTERNOON. THE MODELS SHOW THE FRONT LIFTING NORTHWARD ACROSS FAR SOUTHWEST KANSAS THIS AFTERNOON WITH WARMER AND DRIER AIR MOVING IN. THERE WILL BE A FAIRLY LARGE TEMPERATURE GRADIENT ACROSS THE AREA WITH HAYS ONLY REACHING AROUND 60 OR SO WHILE IN THE SOUTHWEST CORNER, ELKHART AND LIBERAL SHOULD CLIMB INTO THE MID 80S. FARTHER EAST, THE FRONT SHOULD LIFT NORTHWARD TO NEAR MEDICINE LODGE THIS AFTERNOON WHILE A DRYLINE TRAILS FROM THAT AREA SOUTHWARD INTO OKLAHOMA. MODEL SOUNDINGS AROUND MEDICINE LODGE SHOW LAPSE RATES STEEPENING AS THE LOWER ATMOSPHERE MIXES OUT THIS AFTERNOON. IN ADDITION, FAIRLY STRONG 0-6 KM SHEAR ON THE ORDER OF 50-60 KNOTS WILL OVERSPREAD THE REGION. A FEW THUNDERSTORMS COULD DEVELOP ALONG THE DRYLINE/FRONT INTERSECTION AS UPPER LEVEL LIFT INCREASES WITH A 500 MILLIBAR SHORTWAVE APPROACHING THE REGION. ANY STORMS THAT DEVELOP WILL BE MOVING OFF FAIRLY RAPIDLY TO THE EAST AND THE THREAT FOR SEVERE WEATHER WILL LIKELY ONLY BE DURING THE LATE AFTERNOON AND EARLY EVENING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 256 AM CDT WED APR 8 2015 THE UPPER LEVEL SHORTWAVE WILL MOVE OUT OF THE HIGH PLAINS THURSDAY WITH A WEAK UPPER LEVEL RIDGE BUILDING OVER THE ROCKIES AND PLAINS THURSDAY NIGHT THROUGH FRIDAY NIGHT. CLOUDS ARE EXPECTED TO DECREASE IN COVERAGE OVER NORTHERN KANSAS THURSDAY WITH MOSTLY CLEAR SKIES ANTICIPATED THERE AND ELSEWHERE THROUGH FRIDAY. TOWARDS THE SURFACE, A DOME OF HIGH PRESSURE WILL BUILD INTO THE AREA BEHIND THE PREVIOUS SYSTEM LEADING TO NORTH TO NORTHWEST WINDS ACROSS WESTERN KANSAS. THE CENTER OF HIGH PRESSURE MOVES EAST OF THE AREA BY FRIDAY SHIFTING WINDS BACK TO MORE OF A SOUTHERLY DIRECTION. SOUTHERLY WINDS CONTINUE FRIDAY NIGHT WITH A SLIGHT INCREASE IN HIGH CLOUDS AS THE NEXT SYSTEM, ELABORATED ABOUT BELOW, APPROACHES. ATTENTION THEN FOCUSES ON THE WEEKEND AS AN UPPER LEVEL SHORTWAVE INTENSIFIES ABOVE THE DESERT SOUTHWEST THEN TRACKS EASTWARD ACROSS THE SOUTHERN ROCKIES BEFORE CURLING NORTHWARD INTO THE PLAINS. TOWARDS THE SURFACE, THE AFOREMENTIONED DOME OF HIGH PRESSURE WILL CONTINUE TO SHIFT EASTWARD AS THIS FEATURE APPROACHES ALLOWING GULF MOISTURE TO BE PUSHED NORTH INTO THE PLAINS. A FEW THUNDERSTORMS WILL BE POSSIBLE OVER THE WEEKEND WITH INCREASED CLOUD COVER. A QUIET PATTERN THEN RETURNS EARLY NEXT WEEK AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE SOUTHWEST UNITED STATES. AS FOR TEMPERATURES, HIGHS WILL GENERALLY BE IN THE 60S THURSDAY AND FRIDAY WITH LOWS IN THE 30S THURSDAY NIGHT AND IN THE MID 40S FRIDAY NIGHT. HIGHS THEN REBOUND INTO THE 70S SATURDAY WITH CLOSER TO 80 DEGREES EXPECTED ON SUNDAY. LOWS DURING THIS TIME FRAME WILL GENERALLY RANGE FROM THE MID 40S TO MID 50S. HIGHS DURING THE BEGINNING OF NEXT WEEK LOOK TO BE IN THE 70S WITH LOWS CONTINUING TO RANGE FROM THE MID 40S TO MID 50S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1215 PM CDT WED APR 8 2015 STATUS AND FOG WILL ERODE THIS AFTERNOON AS A SURFACE BOUNDARY BEGINS TO SLOWLY MOVE NORTH ACROSS SOUTHWEST KANSAS. AT THIS TIME BASED ON THE LATEST TRENDS FROM THE HRRR AND RAP WILL GRADUALLY IMPROVE CEILING WITH VFR CONDITIONS DEVELOPING BETWEEN 20Z AND 22Z AT DDC AND GCK. HYS WILL IMPROVE TO MVFR. VFR CONDITIONS AT HYS IS EXPECTED TO DEVELOP TOWARDS 00Z THURSDAY. THE PREVAILING WIND THIS AFTERNOON NORTH OF THIS FRONT WILL BE NORTHERLY AT 10 KNOTS OR LESS. NORTHWEST WINDS WILL DEVELOP OVERNIGHT AS A COLD FRONT CROSSES WESTERN KANSAS. THE NORTHWESTERLY WINDS WILL INCREASE BY LATE MORNING THURSDAY AS STRONGER BOUNDARY LAYER WINDS MIXED DOWN TO THE SURFACE. && .FIRE WEATHER... ISSUED AT 400 AM CDT WED APR 8 2015 RED FLAG CONDITIONS WILL REDEVELOP OVER FAR SOUTHWEST KANSAS AGAIN THIS AFTERNOON AS A FRONTAL BOUNDARY ALONG THE OKLAHOMA BORDER LIFTS TO THE NORTH, ALLOWING VERY WARM AND DRY AIR BACK INTO THE AREA. THE FRONT WILL BE SLOW TO MOVE SO THE CRITICAL AREA WILL BE FAIRLY SMALL IN THE SOUTHWEST CORNER OF THE STATE. && .PRELIMINARY POINT TEMPS/POPS... DDC 79 46 66 35 / 10 10 10 0 GCK 77 42 64 34 / 10 10 10 0 EHA 83 42 65 35 / 0 10 10 0 LBL 86 44 67 36 / 0 0 10 0 HYS 60 45 62 34 / 10 20 10 0 P28 82 53 72 38 / 20 10 10 0 && .DDC WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR KSZ061-062-074>076-084>088. && $$ UPDATE...JTL SHORT TERM...GERARD LONG AVIATION...BURGERT FIRE WEATHER...GERARD
AREA FORECAST DISCUSSION
NWS WICHITA KS
1207 PM CDT WED APR 8 2015 .MESOSCALE DISCUSSION... ISSUED AT 1037 AM CDT WED APR 8 2015 LOOKS LIKE THE SCENARIO MAY BE STARTING TO SHOW ITSELF. RADAR DATA SHOWING SOME LIGHT RETURNS OVER OKLAHOMA. THIS MATCHES WELL WITH THE HRRR/RAP RUNS...WHICH HAVE BEEN SUGGESTING TWO ROUNDS OF STORMS. THE MOST LIKELY SCENARIO RIGHT NOW LOOKS LIKE THE WEAK RETURNS WILL DEVELOP INTO ELEVATED STORMS ACROSS OKLAHOMA. THESE ARE EXPECTED TO MOVE NORTHEAST INTO SOUTH-CENTRAL KANSAS AROUND 19Z AND MOVE THROUGH SOUTHEAST KANSAS EAST OF THE TURNPIKE. AS STATED...THESE WILL MORE THAN LIKELY BE ELEVATED WITH A VERY LARGE HAIL AND WIND THREAT. IF THE STORMS CAN GET SURFACE BASED...THEN IT SEEMS THAT WE COULD GET A TORNADO...BUT THAT REMAINS UNCERTAIN. THE SECOND ROUND OCCURS AROUND 00Z WHERE THE DRYLINE RETREATS AND SHEAR INCREASES AS A RESULT OF THE LOW LEVEL JET AND UPPER LEVEL DISTURBANCE COUPLING AND MOVING THROUGH. THIS IS THE SIGNIFICANT TORNADO AREA...SOUTH-CENTRAL KANSAS. KRC .SYNOPSIS... ISSUED AT 332 AM CDT WED APR 8 2015 WATER VAPOR IMAGERY SHOWS A STRONG SHORTWAVE TRACKING OVER THE CENTRAL GREAT BASIN. AT THE SURFACE...LOW PRESSURE IS SITUATED OVER SE CO WITH THE SYNOPTIC FRONT STRETCHING FROM JUST NORTH OF KGAG TO BETWEEN KCNU AND KPPF. MEANWHILE...A LOSE DRYLINE EXTENDS ACROSS THE OK PANHANDLE AND INTO WEST TX. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 332 AM CDT WED APR 8 2015 ELEVATED STORMS DEVELOPED A COUPLE HOURS AGO OVER THE FLINT HILLS IN RESPONSE TO A RAPID INCREASE IN MOISTURE TRANSPORT IN THE 850-700MB LAYER. THIS ACTIVITY SHOULD FOR THE MOST PART STAY NORTHEAST OF THE FORECAST AREA. SIGNIFICANT SEVERE STORMS STILL LOOK LIKELY THIS AFTERNOON AND EVENING. CURRENTLY HAVE A LEAN TO THE RAP13 DUE TO ITS PERFORMANCE WITH THE CONVECTION THAT OCCURRED OVER THE LAST SEVERAL HOURS OVER SE KS. IN ADDITION...IT SEEMS TO BE DOING A DECENT JOB CAPTURING THE CURRENT ELEVATED CONVECTION. THE GFS LIFTS THE WARM FRONT MUCH FURTHER NORTH COMPARED TO THE NAM AND RAP WITH THE FRONT ALONG I-70. MEANWHILE THE RAP AND NAM LIFT THE FRONT TO JUST NORTH OF KICT TO SOUTH OF KSLN. CURRENT THINKING IS THAT THE TRIPLE POINT BY LATE AFTERNOON WILL BE SITUATED JUST SOUTHWEST OF THE FORECAST AREA NEAR OR JUST NORTH OF KGAG WITH THE SYNOPTIC FRONT EXTENDING TO THE NORTHEAST NEAR KICT AND THEN TO NEAR KEMP. WATER VAPOR IMAGERY SHOWS A LEAD IMPULSE/JET MAX OVER NORTHERN BAJA. EXPECTING STORMS TO DEVELOP NEAR THE TRIPLE POINT AS THIS FEATURE MOVES OUT OF THE SOUTHERN HIGH PLAINS. ADDITIONAL DEVELOPMENT CAN THEN BE EXPECTED NORTHEAST ALONG THE SYNOPTIC FRONT. IT SEEMS WITH EACH MODEL RUN THE DEEP LAYER SHEAR HAS INCREASED SLIGHTLY AND THE 00Z RUNS WERE NO EXCEPTION...WITH AROUND 50KTS OF 0-6KM SHEAR AND 65-80KTS OF 0-8KM SHEAR OVER SOUTH CENTRAL KS. THESE SHEAR VALUES WILL COMBINE WITH 2000-3000J/KG OF CAPE TO ALLOW ANY STORM THAT DEVELOPS TO QUICKLY BECOME SEVERE. THE SCARY PART IS THAT WITH THE RETREATING DRYLINE AFTER 00Z...THE ENVIRONMENT ACTUALLY BECOMES MORE FAVORABLE AFTER DARK AS WINDS BACK AND THE LOW LEVEL JET GETS GOING. SO NOT OUT OF THE QUESTION TO GET A TORNADO AFTER DARK OVER SOUTH CENTRAL KS. THE BEST TORNADO POTENTIAL TONIGHT LOOKS TO BE SOUTH OF HIGHWAY 50 AND WEST OF HIGHWAY 99. IF THE NAM AND RAP13 VERIFIES...SEVERE STORMS OVER CENTRAL KS WOULD BE LESS LIKELY. BY 12Z THU...THE SHORTWAVE WILL BE TRACKING ACROSS NORTHERN KS/NEBRASKA WITH THE SYNOPTIC FRONT CATCHING UP TO THE DRYLINE AND SURGING EAST. WHILE THERE MAYBE SOME REMNANT STORMS OVER SE KS AROUND SUNRISE...THE BULK OF THE ACTIVITY AFTER 15Z THU WILL BE EAST OF THE FORECAST AREA. IT NOW LOOKS LIKE THE BETTER CHANCES FOR PRECIP ON THE BACKSIDE OF THIS SYSTEM SHOULD STAY NORTH OF THE FORECAST AREA THU. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 332 AM CDT WED APR 8 2015 A LARGE AREA OF HIGH PRESSURE WILL ENCOMPASS THE PLAINS FOR FRI WITH TEMPS FINALLY GETTING BACK TO SEASONAL VALUES. BOTH THE GFS AND ECMWF BRING A SOUTHERN STREAM SYSTEM OUT OF THE BAJA REGION AND INTO WEST TX BY SUN EVENING. WARM ADVECTION AHEAD OF THIS SYSTEM MAY BRING SOME SCATTERED SHOWERS AND STORMS SAT BUT THE BETTER PRECIP CHANCES LOOK TO ARRIVE SUN NIGHT AND CONTINUE THROUGH MON WHEN THE IMPULSE LIFTS ACROSS THE PLAINS. THE GFS HAS THIS FEATURE QUITE A BIT FURTHER WEST COMPARED TO THE ECMWF WHICH RESULTS IN THE ECMWF BEING THE WETTER SOLUTION. LAWSON && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1208 PM CDT WED APR 8 2015 CONVECTION NOW DEVELOPING OVER OKLAHOMA WILL MOVE NORTHEAST INTO THE AIRSPACE AND CONTINUE WITH SEVERAL ROUNDS THROUGH 6Z. THIS WILL AFFECT ALL AIRPORTS AND FIELDS ALONG AND SOUTHEAST OF KSLN- KVNX. THESE STORMS WILL BE SEVERE AND SHOULD BE AVOIDED. FOG...WHICH CONTINUES TO AFFECT KHUT...KRSL...KSLN HAS BEEN SLOW TO BURN OFF. THINK IT SHOULD BE GONE BY 21Z. VFR CONDITIONS SHOULD PERSIST THROUGH 03Z...WITH FOG REDEVELOPMENT THERE POSSIBLE THROUGH 12Z. THE COLD FRONT WILL CLEAR THE AREA BY 14Z. KRC && .FIRE WEATHER... ISSUED AT 332 AM CDT WED APR 8 2015 MAIN FIRE WEATHER CONCERNS LOOK TO ON THURSDAY. EVEN WITH PLENTY OF LOW LEVEL MOISTURE...VERY HIGH FIRE DANGER WILL BE IN PLACE OVER SOUTH CENTRAL AND SE KS DUE TO GUSTY SOUTH WINDS. HOWEVER...THE CRITICAL FIRE WEATHER DAY LOOKS TO BE THU. THIS IS WHEN STRONG NW WINDS WILL BE IN PLACE BY THE AFTERNOON HOURS ALONG WITH RH`S IN THE 35-45% RANGE. WIND SPEEDS THU AFTERNOON WILL BE IN THE 20-30 MPH RANGE WITH HIGHER GUSTS. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 83 56 71 38 / 30 30 10 0 HUTCHINSON 75 52 67 37 / 30 20 10 0 NEWTON 77 54 67 38 / 40 30 10 0 ELDORADO 83 60 69 40 / 40 40 10 10 WINFIELD-KWLD 85 61 72 41 / 40 30 10 0 RUSSELL 64 46 63 35 / 20 20 10 10 GREAT BEND 69 46 64 35 / 20 10 10 0 SALINA 67 50 65 35 / 30 30 20 10 MCPHERSON 70 51 66 36 / 30 30 10 10 COFFEYVILLE 82 65 76 43 / 40 40 30 10 CHANUTE 78 64 73 41 / 40 50 30 10 IOLA 78 63 72 40 / 40 50 30 10 PARSONS-KPPF 81 64 74 42 / 40 50 30 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1045 AM CDT WED APR 8 2015 .MESOSCALE DISCUSSION... ISSUED AT 1037 AM CDT WED APR 8 2015 LOOKS LIKE THE SCENARIO MAY BE STARTING TO SHOW ITSELF. RADAR DATA SHOWING SOME LIGHT RETURNS OVER OKLAHOMA. THIS MATCHES WELL WITH THE HRRR/RAP RUNS...WHICH HAVE BEEN SUGGESTING TWO ROUNDS OF STORMS. THE MOST LIKELY SCENARIO RIGHT NOW LOOKS LIKE THE WEAK RETURNS WILL DEVELOP INTO ELEVATED STORMS ACROSS OKLAHOMA. THESE ARE EXPECTED TO MOVE NORTHEAST INTO SOUTH-CENTRAL KANSAS AROUND 19Z AND MOVE THROUGH SOUTHEAST KANSAS EAST OF THE TURNPIKE. AS STATED...THESE WILL MORE THAN LIKELY BE ELEVATED WITH A VERY LARGE HAIL AND WIND THREAT. IF THE STORMS CAN GET SURFACE BASED...THEN IT SEEMS THAT WE COULD GET A TORNADO...BUT THAT REMAINS UNCERTAIN. THE SECOND ROUND OCCURS AROUND 00Z WHERE THE DRYLINE RETREATS AND SHEAR INCREASES AS A RESULT OF THE LOW LEVEL JET AND UPPER LEVEL DISTURBANCE COUPLING AND MOVING THROUGH. THIS IS THE SIGNIFICANT TORNADO AREA...SOUTH-CENTRAL KANSAS. KRC && .SYNOPSIS... ISSUED AT 332 AM CDT WED APR 8 2015 WATER VAPOR IMAGERY SHOWS A STRONG SHORTWAVE TRACKING OVER THE CENTRAL GREAT BASIN. AT THE SURFACE...LOW PRESSURE IS SITUATED OVER SE CO WITH THE SYNOPTIC FRONT STRETCHING FROM JUST NORTH OF KGAG TO BETWEEN KCNU AND KPPF. MEANWHILE...A LOSE DRYLINE EXTENDS ACROSS THE OK PANHANDLE AND INTO WEST TX. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 332 AM CDT WED APR 8 2015 ELEVATED STORMS DEVELOPED A COUPLE HOURS AGO OVER THE FLINT HILLS IN RESPONSE TO A RAPID INCREASE IN MOISTURE TRANSPORT IN THE 850-700MB LAYER. THIS ACTIVITY SHOULD FOR THE MOST PART STAY NORTHEAST OF THE FORECAST AREA. SIGNIFICANT SEVERE STORMS STILL LOOK LIKELY THIS AFTERNOON AND EVENING. CURRENTLY HAVE A LEAN TO THE RAP13 DUE TO ITS PERFORMANCE WITH THE CONVECTION THAT OCCURRED OVER THE LAST SEVERAL HOURS OVER SE KS. IN ADDITION...IT SEEMS TO BE DOING A DECENT JOB CAPTURING THE CURRENT ELEVATED CONVECTION. THE GFS LIFTS THE WARM FRONT MUCH FURTHER NORTH COMPARED TO THE NAM AND RAP WITH THE FRONT ALONG I-70. MEANWHILE THE RAP AND NAM LIFT THE FRONT TO JUST NORTH OF KICT TO SOUTH OF KSLN. CURRENT THINKING IS THAT THE TRIPLE POINT BY LATE AFTERNOON WILL BE SITUATED JUST SOUTHWEST OF THE FORECAST AREA NEAR OR JUST NORTH OF KGAG WITH THE SYNOPTIC FRONT EXTENDING TO THE NORTHEAST NEAR KICT AND THEN TO NEAR KEMP. WATER VAPOR IMAGERY SHOWS A LEAD IMPULSE/JET MAX OVER NORTHERN BAJA. EXPECTING STORMS TO DEVELOP NEAR THE TRIPLE POINT AS THIS FEATURE MOVES OUT OF THE SOUTHERN HIGH PLAINS. ADDITIONAL DEVELOPMENT CAN THEN BE EXPECTED NORTHEAST ALONG THE SYNOPTIC FRONT. IT SEEMS WITH EACH MODEL RUN THE DEEP LAYER SHEAR HAS INCREASED SLIGHTLY AND THE 00Z RUNS WERE NO EXCEPTION...WITH AROUND 50KTS OF 0-6KM SHEAR AND 65-80KTS OF 0-8KM SHEAR OVER SOUTH CENTRAL KS. THESE SHEAR VALUES WILL COMBINE WITH 2000-3000J/KG OF CAPE TO ALLOW ANY STORM THAT DEVELOPS TO QUICKLY BECOME SEVERE. THE SCARY PART IS THAT WITH THE RETREATING DRYLINE AFTER 00Z...THE ENVIRONMENT ACTUALLY BECOMES MORE FAVORABLE AFTER DARK AS WINDS BACK AND THE LOW LEVEL JET GETS GOING. SO NOT OUT OF THE QUESTION TO GET A TORNADO AFTER DARK OVER SOUTH CENTRAL KS. THE BEST TORNADO POTENTIAL TONIGHT LOOKS TO BE SOUTH OF HIGHWAY 50 AND WEST OF HIGHWAY 99. IF THE NAM AND RAP13 VERIFIES...SEVERE STORMS OVER CENTRAL KS WOULD BE LESS LIKELY. BY 12Z THU...THE SHORTWAVE WILL BE TRACKING ACROSS NORTHERN KS/NEBRASKA WITH THE SYNOPTIC FRONT CATCHING UP TO THE DRYLINE AND SURGING EAST. WHILE THERE MAYBE SOME REMNANT STORMS OVER SE KS AROUND SUNRISE...THE BULK OF THE ACTIVITY AFTER 15Z THU WILL BE EAST OF THE FORECAST AREA. IT NOW LOOKS LIKE THE BETTER CHANCES FOR PRECIP ON THE BACKSIDE OF THIS SYSTEM SHOULD STAY NORTH OF THE FORECAST AREA THU. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 332 AM CDT WED APR 8 2015 A LARGE AREA OF HIGH PRESSURE WILL ENCOMPASS THE PLAINS FOR FRI WITH TEMPS FINALLY GETTING BACK TO SEASONAL VALUES. BOTH THE GFS AND ECMWF BRING A SOUTHERN STREAM SYSTEM OUT OF THE BAJA REGION AND INTO WEST TX BY SUN EVENING. WARM ADVECTION AHEAD OF THIS SYSTEM MAY BRING SOME SCATTERED SHOWERS AND STORMS SAT BUT THE BETTER PRECIP CHANCES LOOK TO ARRIVE SUN NIGHT AND CONTINUE THROUGH MON WHEN THE IMPULSE LIFTS ACROSS THE PLAINS. THE GFS HAS THIS FEATURE QUITE A BIT FURTHER WEST COMPARED TO THE ECMWF WHICH RESULTS IN THE ECMWF BEING THE WETTER SOLUTION. LAWSON && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1147 PM CDT TUE APR 7 2015 IFR/LIFR CIGS CONTINUE TO SPREAD SOUTH AND EAST IN THE WAKE OF THE FRONT WHILE SEVERE STORMS LINGER ACROSS SOUTHEAST KANSAS THROUGH THE PREDAWN HOURS. A WARM FRONT IS PROGGED TO LIFT NORTH DURING THE DAY ON WEDNESDAY ALLOWING MVFR/VFR TO RETURN DURING THE LATE MORNING/EARLY AFTERNOON. WINDS ARE EXPECTED TO SHIFT TO THE SOUTH WITH SCATTERED STORMS DEVELOPING ALONG A DRY LINE AND ALONG THE WARM FRONT LATE WED AFTERNOON/EVENING SPREADING EASTWARD ACROSS THE AREA. && .FIRE WEATHER... ISSUED AT 332 AM CDT WED APR 8 2015 MAIN FIRE WEATHER CONCERNS LOOK TO ON THURSDAY. EVEN WITH PLENTY OF LOW LEVEL MOISTURE...VERY HIGH FIRE DANGER WILL BE IN PLACE OVER SOUTH CENTRAL AND SE KS DUE TO GUSTY SOUTH WINDS. HOWEVER...THE CRITICAL FIRE WEATHER DAY LOOKS TO BE THU. THIS IS WHEN STRONG NW WINDS WILL BE IN PLACE BY THE AFTERNOON HOURS ALONG WITH RH`S IN THE 35-45% RANGE. WIND SPEEDS THU AFTERNOON WILL BE IN THE 20-30 MPH RANGE WITH HIGHER GUSTS. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 79 56 71 38 / 30 30 10 0 HUTCHINSON 74 52 67 37 / 30 20 10 0 NEWTON 77 54 67 38 / 40 30 10 0 ELDORADO 80 60 69 40 / 40 40 10 10 WINFIELD-KWLD 82 61 72 41 / 40 30 10 0 RUSSELL 60 46 63 35 / 20 20 10 10 GREAT BEND 65 46 64 35 / 20 10 10 0 SALINA 70 50 65 35 / 30 30 20 10 MCPHERSON 72 51 66 36 / 30 30 10 10 COFFEYVILLE 82 65 76 43 / 40 40 30 10 CHANUTE 81 64 73 41 / 40 50 30 10 IOLA 80 63 72 40 / 40 50 30 10 PARSONS-KPPF 81 64 74 42 / 40 50 30 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS WICHITA KS
951 AM CDT WED APR 8 2015 .MESOSCALE DISCUSSION... ISSUED AT 950 AM CDT WED APR 8 2015 LATEST DATA ANALYSIS SHOWS THE FRONT EXTENDING FROM NEAR KMCI- KEMP-KVNX. IT IS SLOWLY MOVING NORTH AS OF 1430Z. 0-6KM BULK SHEAR VALUES VIA LAPS ARE 40-50 KNOTS ALONG THE FRONT WITH 0-1KM BULK SHEAR VALUES OF 15 TO 20 KNOTS. THIS MEANS THAT CONDITIONS REMAIN FAVORABLE FOR TORNADIC THUNDERSTORMS THIS AFTERNOON. LATEST RUNS OF THE HRRR...EXPERIMENTAL HRRR...AND THE RAP ARE SUGGESTING CONVECTIVE INITIATION EARLIER...PERHAPS AS EARLY AS 19-20Z. THIS IS LIKELY FROM THE UPPER LEVEL DISTURBANCE BEING FURTHER EAST THAN SOME OF THE PREVIOUS RUNS OF THE MODELS. MOREOVER...TRENDS HAVE BEEN SUGGESTING STORMS SLIGHTLY FURTHER EAST...BUT WANT TO HOLD OFF ON MAKING ANY CONCLUSIONS ON THAT UNTIL IT IS VERY CLEAR. RIGHT NOW...THINKING THE THREAT AREA IS STILL FINE WITH INITIATION AROUND 20Z. KRC && .SYNOPSIS... ISSUED AT 332 AM CDT WED APR 8 2015 WATER VAPOR IMAGERY SHOWS A STRONG SHORTWAVE TRACKING OVER THE CENTRAL GREAT BASIN. AT THE SURFACE...LOW PRESSURE IS SITUATED OVER SE CO WITH THE SYNOPTIC FRONT STRETCHING FROM JUST NORTH OF KGAG TO BETWEEN KCNU AND KPPF. MEANWHILE...A LOSE DRYLINE EXTENDS ACROSS THE OK PANHANDLE AND INTO WEST TX. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 332 AM CDT WED APR 8 2015 ELEVATED STORMS DEVELOPED A COUPLE HOURS AGO OVER THE FLINT HILLS IN RESPONSE TO A RAPID INCREASE IN MOISTURE TRANSPORT IN THE 850-700MB LAYER. THIS ACTIVITY SHOULD FOR THE MOST PART STAY NORTHEAST OF THE FORECAST AREA. SIGNIFICANT SEVERE STORMS STILL LOOK LIKELY THIS AFTERNOON AND EVENING. CURRENTLY HAVE A LEAN TO THE RAP13 DUE TO ITS PERFORMANCE WITH THE CONVECTION THAT OCCURRED OVER THE LAST SEVERAL HOURS OVER SE KS. IN ADDITION...IT SEEMS TO BE DOING A DECENT JOB CAPTURING THE CURRENT ELEVATED CONVECTION. THE GFS LIFTS THE WARM FRONT MUCH FURTHER NORTH COMPARED TO THE NAM AND RAP WITH THE FRONT ALONG I-70. MEANWHILE THE RAP AND NAM LIFT THE FRONT TO JUST NORTH OF KICT TO SOUTH OF KSLN. CURRENT THINKING IS THAT THE TRIPLE POINT BY LATE AFTERNOON WILL BE SITUATED JUST SOUTHWEST OF THE FORECAST AREA NEAR OR JUST NORTH OF KGAG WITH THE SYNOPTIC FRONT EXTENDING TO THE NORTHEAST NEAR KICT AND THEN TO NEAR KEMP. WATER VAPOR IMAGERY SHOWS A LEAD IMPULSE/JET MAX OVER NORTHERN BAJA. EXPECTING STORMS TO DEVELOP NEAR THE TRIPLE POINT AS THIS FEATURE MOVES OUT OF THE SOUTHERN HIGH PLAINS. ADDITIONAL DEVELOPMENT CAN THEN BE EXPECTED NORTHEAST ALONG THE SYNOPTIC FRONT. IT SEEMS WITH EACH MODEL RUN THE DEEP LAYER SHEAR HAS INCREASED SLIGHTLY AND THE 00Z RUNS WERE NO EXCEPTION...WITH AROUND 50KTS OF 0-6KM SHEAR AND 65-80KTS OF 0-8KM SHEAR OVER SOUTH CENTRAL KS. THESE SHEAR VALUES WILL COMBINE WITH 2000-3000J/KG OF CAPE TO ALLOW ANY STORM THAT DEVELOPS TO QUICKLY BECOME SEVERE. THE SCARY PART IS THAT WITH THE RETREATING DRYLINE AFTER 00Z...THE ENVIRONMENT ACTUALLY BECOMES MORE FAVORABLE AFTER DARK AS WINDS BACK AND THE LOW LEVEL JET GETS GOING. SO NOT OUT OF THE QUESTION TO GET A TORNADO AFTER DARK OVER SOUTH CENTRAL KS. THE BEST TORNADO POTENTIAL TONIGHT LOOKS TO BE SOUTH OF HIGHWAY 50 AND WEST OF HIGHWAY 99. IF THE NAM AND RAP13 VERIFIES...SEVERE STORMS OVER CENTRAL KS WOULD BE LESS LIKELY. BY 12Z THU...THE SHORTWAVE WILL BE TRACKING ACROSS NORTHERN KS/NEBRASKA WITH THE SYNOPTIC FRONT CATCHING UP TO THE DRYLINE AND SURGING EAST. WHILE THERE MAYBE SOME REMNANT STORMS OVER SE KS AROUND SUNRISE...THE BULK OF THE ACTIVITY AFTER 15Z THU WILL BE EAST OF THE FORECAST AREA. IT NOW LOOKS LIKE THE BETTER CHANCES FOR PRECIP ON THE BACKSIDE OF THIS SYSTEM SHOULD STAY NORTH OF THE FORECAST AREA THU. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 332 AM CDT WED APR 8 2015 A LARGE AREA OF HIGH PRESSURE WILL ENCOMPASS THE PLAINS FOR FRI WITH TEMPS FINALLY GETTING BACK TO SEASONAL VALUES. BOTH THE GFS AND ECMWF BRING A SOUTHERN STREAM SYSTEM OUT OF THE BAJA REGION AND INTO WEST TX BY SUN EVENING. WARM ADVECTION AHEAD OF THIS SYSTEM MAY BRING SOME SCATTERED SHOWERS AND STORMS SAT BUT THE BETTER PRECIP CHANCES LOOK TO ARRIVE SUN NIGHT AND CONTINUE THROUGH MON WHEN THE IMPULSE LIFTS ACROSS THE PLAINS. THE GFS HAS THIS FEATURE QUITE A BIT FURTHER WEST COMPARED TO THE ECMWF WHICH RESULTS IN THE ECMWF BEING THE WETTER SOLUTION. LAWSON && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1147 PM CDT TUE APR 7 2015 IFR/LIFR CIGS CONTINUE TO SPREAD SOUTH AND EAST IN THE WAKE OF THE FRONT WHILE SEVERE STORMS LINGER ACROSS SOUTHEAST KANSAS THROUGH THE PREDAWN HOURS. A WARM FRONT IS PROGGED TO LIFT NORTH DURING THE DAY ON WEDNESDAY ALLOWING MVFR/VFR TO RETURN DURING THE LATE MORNING/EARLY AFTERNOON. WINDS ARE EXPECTED TO SHIFT TO THE SOUTH WITH SCATTERED STORMS DEVELOPING ALONG A DRY LINE AND ALONG THE WARM FRONT LATE WED AFTERNOON/EVENING SPREADING EASTWARD ACROSS THE AREA. && .FIRE WEATHER... ISSUED AT 332 AM CDT WED APR 8 2015 MAIN FIRE WEATHER CONCERNS LOOK TO ON THURSDAY. EVEN WITH PLENTY OF LOW LEVEL MOISTURE...VERY HIGH FIRE DANGER WILL BE IN PLACE OVER SOUTH CENTRAL AND SE KS DUE TO GUSTY SOUTH WINDS. HOWEVER...THE CRITICAL FIRE WEATHER DAY LOOKS TO BE THU. THIS IS WHEN STRONG NW WINDS WILL BE IN PLACE BY THE AFTERNOON HOURS ALONG WITH RH`S IN THE 35-45% RANGE. WIND SPEEDS THU AFTERNOON WILL BE IN THE 20-30 MPH RANGE WITH HIGHER GUSTS. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 79 56 71 38 / 30 30 10 0 HUTCHINSON 74 52 67 37 / 30 20 10 0 NEWTON 77 54 67 38 / 40 30 10 0 ELDORADO 80 60 69 40 / 40 40 10 10 WINFIELD-KWLD 82 61 72 41 / 40 30 10 0 RUSSELL 60 46 63 35 / 20 20 10 10 GREAT BEND 65 46 64 35 / 20 10 10 0 SALINA 70 50 65 35 / 30 30 20 10 MCPHERSON 72 51 66 36 / 30 30 10 10 COFFEYVILLE 82 65 76 43 / 40 40 30 10 CHANUTE 81 64 73 41 / 40 50 30 10 IOLA 80 63 72 40 / 40 50 30 10 PARSONS-KPPF 81 64 74 42 / 40 50 30 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS WICHITA KS
333 AM CDT WED APR 8 2015 .SYNOPSIS... ISSUED AT 332 AM CDT WED APR 8 2015 WATER VAPOR IMAGERY SHOWS A STRONG SHORTWAVE TRACKING OVER THE CENTRAL GREAT BASIN. AT THE SURFACE...LOW PRESSURE IS SITUATED OVER SE CO WITH THE SYNOPTIC FRONT STRETCHING FROM JUST NORTH OF KGAG TO BETWEEN KCNU AND KPPF. MEANWHILE...A LOSE DRYLINE EXTENDS ACROSS THE OK PANHANDLE AND INTO WEST TX. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 332 AM CDT WED APR 8 2015 ELEVATED STORMS DEVELOPED A COUPLE HOURS AGO OVER THE FLINT HILLS IN RESPONSE TO A RAPID INCREASE IN MOISTURE TRANSPORT IN THE 850-700MB LAYER. THIS ACTIVITY SHOULD FOR THE MOST PART STAY NORTHEAST OF THE FORECAST AREA. SIGNIFICANT SEVERE STORMS STILL LOOK LIKELY THIS AFTERNOON AND EVENING. CURRENTLY HAVE A LEAN TO THE RAP13 DUE TO ITS PERFORMANCE WITH THE CONVECTION THAT OCCURRED OVER THE LAST SEVERAL HOURS OVER SE KS. IN ADDITION...IT SEEMS TO BE DOING A DECENT JOB CAPTURING THE CURRENT ELEVATED CONVECTION. THE GFS LIFTS THE WARM FRONT MUCH FURTHER NORTH COMPARED TO THE NAM AND RAP WITH THE FRONT ALONG I-70. MEANWHILE THE RAP AND NAM LIFT THE FRONT TO JUST NORTH OF KICT TO SOUTH OF KSLN. CURRENT THINKING IS THAT THE TRIPLE POINT BY LATE AFTERNOON WILL BE SITUATED JUST SOUTHWEST OF THE FORECAST AREA NEAR OR JUST NORTH OF KGAG WITH THE SYNOPTIC FRONT EXTENDING TO THE NORTHEAST NEAR KICT AND THEN TO NEAR KEMP. WATER VAPOR IMAGERY SHOWS A LEAD IMPULSE/JET MAX OVER NORTHERN BAJA. EXPECTING STORMS TO DEVELOP NEAR THE TRIPLE POINT AS THIS FEATURE MOVES OUT OF THE SOUTHERN HIGH PLAINS. ADDITIONAL DEVELOPMENT CAN THEN BE EXPECTED NORTHEAST ALONG THE SYNOPTIC FRONT. IT SEEMS WITH EACH MODEL RUN THE DEEP LAYER SHEAR HAS INCREASED SLIGHTLY AND THE 00Z RUNS WERE NO EXCEPTION...WITH AROUND 50KTS OF 0-6KM SHEAR AND 65-80KTS OF 0-8KM SHEAR OVER SOUTH CENTRAL KS. THESE SHEAR VALUES WILL COMBINE WITH 2000-3000J/KG OF CAPE TO ALLOW ANY STORM THAT DEVELOPS TO QUICKLY BECOME SEVERE. THE SCARY PART IS THAT WITH THE RETREATING DRYLINE AFTER 00Z...THE ENVIRONMENT ACTUALLY BECOMES MORE FAVORABLE AFTER DARK AS WINDS BACK AND THE LOW LEVEL JET GETS GOING. SO NOT OUT OF THE QUESTION TO GET A TORNADO AFTER DARK OVER SOUTH CENTRAL KS. THE BEST TORNADO POTENTIAL TONIGHT LOOKS TO BE SOUTH OF HIGHWAY 50 AND WEST OF HIGHWAY 99. IF THE NAM AND RAP13 VERIFIES...SEVERE STORMS OVER CENTRAL KS WOULD BE LESS LIKELY. BY 12Z THU...THE SHORTWAVE WILL BE TRACKING ACROSS NORTHERN KS/NEBRASKA WITH THE SYNOPTIC FRONT CATCHING UP TO THE DRYLINE AND SURGING EAST. WHILE THERE MAYBE SOME REMNANT STORMS OVER SE KS AROUND SUNRISE...THE BULK OF THE ACTIVITY AFTER 15Z THU WILL BE EAST OF THE FORECAST AREA. IT NOW LOOKS LIKE THE BETTER CHANCES FOR PRECIP ON THE BACKSIDE OF THIS SYSTEM SHOULD STAY NORTH OF THE FORECAST AREA THU. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 332 AM CDT WED APR 8 2015 A LARGE AREA OF HIGH PRESSURE WILL ENCOMPASS THE PLAINS FOR FRI WITH TEMPS FINALLY GETTING BACK TO SEASONAL VALUES. BOTH THE GFS AND ECMWF BRING A SOUTHERN STREAM SYSTEM OUT OF THE BAJA REGION AND INTO WEST TX BY SUN EVENING. WARM ADVECTION AHEAD OF THIS SYSTEM MAY BRING SOME SCATTERED SHOWERS AND STORMS SAT BUT THE BETTER PRECIP CHANCES LOOK TO ARRIVE SUN NIGHT AND CONTINUE THROUGH MON WHEN THE IMPULSE LIFTS ACROSS THE PLAINS. THE GFS HAS THIS FEATURE QUITE A BIT FURTHER WEST COMPARED TO THE ECMWF WHICH RESULTS IN THE ECMWF BEING THE WETTER SOLUTION. LAWSON && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1147 PM CDT TUE APR 7 2015 IFR/LIFR CIGS CONTINUE TO SPREAD SOUTH AND EAST IN THE WAKE OF THE FRONT WHILE SEVERE STORMS LINGER ACROSS SOUTHEAST KANSAS THROUGH THE PREDAWN HOURS. A WARM FRONT IS PROGGED TO LIFT NORTH DURING THE DAY ON WEDNESDAY ALLOWING MVFR/VFR TO RETURN DURING THE LATE MORNING/EARLY AFTERNOON. WINDS ARE EXPECTED TO SHIFT TO THE SOUTH WITH SCATTERED STORMS DEVELOPING ALONG A DRY LINE AND ALONG THE WARM FRONT LATE WED AFTERNOON/EVENING SPREADING EASTWARD ACROSS THE AREA. && .FIRE WEATHER... ISSUED AT 332 AM CDT WED APR 8 2015 MAIN FIRE WEATHER CONCERNS LOOK TO ON THURSDAY. EVEN WITH PLENTY OF LOW LEVEL MOISTURE...VERY HIGH FIRE DANGER WILL BE IN PLACE OVER SOUTH CENTRAL AND SE KS DUE TO GUSTY SOUTH WINDS. HOWEVER...THE CRITICAL FIRE WEATHER DAY LOOKS TO BE THU. THIS IS WHEN STRONG NW WINDS WILL BE IN PLACE BY THE AFTERNOON HOURS ALONG WITH RH`S IN THE 35-45% RANGE. WIND SPEEDS THU AFTERNOON WILL BE IN THE 20-30 MPH RANGE WITH HIGHER GUSTS. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 84 55 71 40 / 30 30 10 0 HUTCHINSON 80 51 68 37 / 30 20 10 0 NEWTON 81 53 68 39 / 30 30 10 0 ELDORADO 82 59 70 40 / 30 40 10 10 WINFIELD-KWLD 83 60 74 42 / 30 30 10 0 RUSSELL 70 47 64 34 / 20 20 20 10 GREAT BEND 74 47 65 34 / 20 10 10 0 SALINA 73 50 65 36 / 30 30 20 10 MCPHERSON 77 50 67 37 / 30 30 10 10 COFFEYVILLE 81 65 77 44 / 30 40 30 10 CHANUTE 80 64 75 42 / 30 50 30 10 IOLA 79 63 75 42 / 40 50 30 10 PARSONS-KPPF 81 64 76 43 / 30 50 30 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1033 PM EDT THU APR 9 2015 .UPDATE... ISSUED AT 1033 PM EDT THU APR 9 2015 JUST SENT OUT ONE LAST UPDATE TO THE FORECAST FOR THIS EVENING. UPSTREAM RADAR IMAGERY SHOWING THE NEAREST THUNDERSTORMS TO OUR AREA CURRENTLY MOVING INTO FAR WESTERN KENTUCKY AND SOUTHWESTERN INDIANA. BASED ON THE SOUTHWEST TO NORTHEAST MOVEMENT OF THE INDIVIDUAL STORMS...AND THE EASTWARD MOVEMENT OF THE LINE AS THE WHOLE...IT APPEARS THAT IT MAY BE EVEN LATER BEFORE WE SEE THE FIRST STORMS MOVING INTO OUR WESTERN COUNTIES OVERNIGHT. AS IT STANDS...PRECIP ONSET IS FORECAST TO OCCUR BETWEEN 6 AND 7Z IN OUR FAR NORTHWEST AND WESTERN COUNTIES...WITH THE LINE OF SHOWERS AND STORMS MOVING THROUGH THE CENTRAL AND EASTERN PORTIONS OF THE FORECAST AREA BETWEEN 9 AND 16Z ON FRIDAY. DAMAGING WINDS GUSTS...LARGE HAIL...AND LOCALLY HEAVY RAINFALL AND POSSIBLY FLASH FLOODING WILL REMAIN THREATS WITH THE LINE OF STORMS AS THEY TRACK EASTWARD ACROSS THE AREA. A NEW SET OF ZONES HAS ALREADY BEEN ISSUED BASED ON THE AFOREMENTIONED GRID UPDATES. UPDATE ISSUED AT 813 PM EDT THU APR 9 2015 ANOTHER UPDATE TO THE FORECAST GRIDS AND THE ZONE FORECAST TEXT PRODUCT WERE NECESSARY THIS EVENING. BASED ON CURRENT SATELLITE AND RADAR TRENDS...IT APPEARS THAT PRECIPITATION ONSET ACROSS THE AREA WILL OCCUR A FEW HOURS LATER THAN PREVIOUSLY FORECAST. OVER THE PAST HOUR OR SO THERE HAVE BEEN NO SHOWERS OR STORMS PRESENT ACROSS MOST OF CENTRAL AND ALL OF EASTERN KENTUCKY. BASED ON UPSTREAM RADAR RETURNS...IT APPEARS THAT IT WILL BE MUCH LATER TONIGHT BEFORE WIDESPREAD PRECIPITATION BEGINS TO AFFECT THE AREA. THEREFORE...BOTH THE FORECAST GRIDS AND ZONES WERE UPDATED TO REFLECT THIS NEW TREND. THE SAME ISSUES WITH THE STORMS WILL HOLD TRUE...WITH DAMAGING WINDS...LARGE HAIL...AND LOCALLY HEAVY RAINFALL ALL STILL POSSIBLE. A LINE OF STRONG TO POTENTIALLY SEVERE THUNDERSTORMS IS NOW EXPECTED TO MOVE ACROSS THE AREA BETWEEN ROUGHLY 8 AND 13Z ON FRIDAY. THE FLASH FLOOD WATCH IS STILL IN EFFECT. UPDATE ISSUED AT 641 PM EDT THU APR 9 2015 JUST UPDATED THE GRIDS...ZONE FORECAST TEXT PRODUCT...AND HAZARDOUS WEATHER PRODUCT TO ALL REFLECT THE CANCELLATION OF SEVERE THUNDERSTORM WATCH 40. WITH ONLY A FEW MEAGER THUNDERSTORMS HAVING MOVED ACROSS THE AREA SO FAR THIS EVENING...AND WITH NO NEW STORMS EXPECTED TO AFFECT THE AREA ANY TIME SOON...THE WATCH WAS CANCELLED. THE FLASH FLOOD WATCH IS STILL IN EFFECT. THE GRIDS WERE ALSO FRESHENED UP A BIT USING THE LATEST OBS DATA ACROSS THE BOARD. WILL CONTINUE TO MONITOR CURRENT CONDITIONS TO DETERMINE WHEN TO ISSUE THE NEXT FORECAST UPDATE. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 351 PM EDT THU APR 9 2015 MODELS ARE IN GOOD AGREEMENT IN THE SHORT TERM WITH EASTERN KENTUCKY REMAINING UNDER BROAD SW FLOW TODAY BEFORE AN UL TROUGH SWINGS THROUGH THE AREA THIS EVENING. A WARM FRONT REMAINS TO OUR NORTH...HELPING TO FOCUS SOME OF THE MORE INTENSE CONVECTION SO FAR THIS AFTERNOON. HOWEVER...GIVEN THAT THE ATMOSPHERE IS VERY MOIST AND UNSTABLE...THERE IS STILL A CHANCE FOR SCATTERED CONVECTION ACROSS OUR CWA THIS AFTERNOON AND EVENING WITH BEST CHANCES ALONG THE NORTHERN COUNTIES WHERE A SPC SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED. AND AS THE UL TROUGH APPROACHES THE AREA ALLOWING FOR ADDITIONAL HEIGHT FALLS AND UL ENERGY...THE CHANCES FOR THUNDERSTORMS INCREASE. HIGH RES MODELS SUCH AS THE HRRR AND NAM12 BOTH INDICATE A LULL IN CONVECTION TONIGHT AFTER THE DIURNAL CONVECTION WANES AND BEFORE THE COLD FRONT REACHES OUR AREA. AS SUCH...HAVE INDICATED A DECREASE IN SHOWERS/CONVECTION DURING THAT TIME IN THE POP/SKY/WX GRIDS. BY THE TIME THE COLD FRONT REACHES KY AROUND 06Z...SHOWERS AND THUNDERSTORMS WILL BE NUMEROUS AND WIDESPREAD ACROSS THE MAJORITY OF THE STATE. PER LATEST MODEL OUTPUT AND SOUNDINGS...A CONVECTIVE LINE COULD DEVELOP ALONG AND AHEAD OF THE COLD FRONT OVERNIGHT TONIGHT...ALLOWING FOR A THREAT OF HIGH WINDS AND HEAVY RAIN. WILL HAVE TO SEE HOW THE CONVECTION FORMS WITH THE FRONTAL BOUNDARY LATER TONIGHT...BUT IT IS LIKELY THAT THERE WILL BE AT LEAST WIDESPREAD RAINFALL WITH SOME THUNDERSTORMS AS THE FRONT PASSES THROUGH THE REGION TONIGHT. THERE WONT BE THE ADDED BENEFIT OF DAYTIME HEATING BUT THERE WILL BE ENOUGH MID TO UPPER LEVEL SUPPORT FOR CONVECTION TO SUSTAIN ITSELF. THE COLD FRONT SHOULD THEN EXIT EASTERN KY BY 18Z...FOLLOWED QUICKLY BY COOLER...DRIER AIR AND N TO NW FLOW. THE COOLER AIR BEHIND THE FRONT WILL QUICKLY CUT OFF ANY REMAINING SHOWER ACTIVITY AND DRY THE AIR...DECREASING HUMIDITY LEVELS SUBSTANTIALLY. THIS WILL ALLOW FOR TEMPERATURES TO REMAIN NEAR NORMAL VALUES...IN THE MID 60S...ON SATURDAY AS A HIGH PRESSURE SITS OVERHEAD. THIS IS A BIG CHANGE FROM TODAY/S TEMPERATURES WHICH HAVE SURPASSED THE 80 DEGREE MARK FOR THE FIRST TIME THIS YEAR. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 501 PM EDT THU APR 9 2015 A LARGE AREA OF SURFACE HIGH PRESSURE OVER THE OHIO VALLEY ON SATURDAY WILL BRING DRY WEATHER WHICH SHOULD LAST INTO SUNDAY NIGHT. BY THEN THE HIGH WILL BE MOVING OFF THE EAST COAST...AND MODELS SHOW GULF MOISTURE TRYING TO MAKE A RETURN TO THE NORTH AS ANOTHER COLD FRONT PUSHES IN FROM THE NW. IT NOW LOOKS LIKE THIS FRONT WILL BRING A QUICK CHANCE AT SOME SHOWERS ON MONDAY INTO MONDAY NIGHT. MODELS HAVE NOT BEEN CONSISTENT IN THEIR SOLUTIONS FOR TUESDAY THROUGH THURSDAY. THE 12Z RUNS OF BOTH THE GFS AND ECMWF NOW SUGGEST MAINLY DRY WEATHER FOR TUESDAY INTO WEDNESDAY AS HIGH PRESSURE SLIDES BY TO OUR NORTH...AND THE AFOREMENTIONED COLD FRONT STALLS TO OUR SOUTH AND KEEPS MOISTURE AT BAY. HOWEVER...WITH THIS BEING A RECENT CHANGE...HAVE ONLY TRENDED THE POP LOWER INSTEAD OF REMOVING PRECIP FROM THE FORECAST. 12Z RUNS SHOW A RETURN OF GULF MOISTURE FROM WEDNESDAY INTO THURSDAY...BUT LITTLE IN THE WAY OF INSTABILITY AND HAVE CONTINUED CHANCE POPS FOR SHOWERS AT THAT TIME. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 813 PM EDT THU APR 9 2015 VFR CONDITIONS ARE EXPECTED AT THE TAF SITES THROUGH AROUND 6Z TONIGHT. BETWEEN 6 AND 8Z LOOKS TO BE THE TIME FRAME WHEN THE FIRST SHOWERS AND STORMS BEGIN TO APPROACH THE TAF SITES. A LINE OF STRONG TO SEVERE THUNDERSTORMS IS EXPECTED TO MOVE ACROSS THE AREA BETWEEN ROUGHLY 8 AND 13Z. MVFR CONDITIONS WILL PREVAIL DURING MOST OF THIS PERIOD...BUT THERE WILL LIKELY BE SHORT PERIODS OF TIME WHERE THE RAIN AND WIND WILL BE INTENSE ENOUGH TO YIELD IFR AND LIFR CONDITIONS DURING THE STRONGEST STORMS. THE PRECIP SHOULD BEGIN WINDING DOWN AT THE TAF SITES BETWEEN 12 AND 13Z. THE TAF SITES SHOULD BE PRECIP FREE BY BETWEEN 16 AND 18Z. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...AR SHORT TERM...JVM LONG TERM...HAL AVIATION...AR
AREA FORECAST DISCUSSION
NWS PADUCAH KY
850 PM CDT THU APR 9 2015 .UPDATE... ISSUED AT 850 PM CDT THU APR 9 2015 LATEST IR SATELLITE IMAGERY INDICATES CLOUD TOPS ARE CONTINUING TO COOL...SUGGESTING AN OVERALL INCREASE IN CONVECTIVE ACTIVITY. THE ACTIVITY HAS BEEN RATHER DISORGANIZED ON RADAR UP TO THIS POINT. HOWEVER...THE TREND HAS BEEN FOR ORGANIZATION OF A LINEAR SQUALL LINE RIGHT ALONG THE COLD FRONT. THE LATEST HRRR INDICATES THE CONVECTIVE LINE WILL BE ORIENTED ROUGHLY ALONG A KEVV/KPAH LINE AROUND 06Z. INSTABILITY HAS BEEN SLOW TO WANE DUE TO A STRONG WARM MOIST SOUTHERLY FLOW. THE KPAH RADAR VAD WIND PROFILE SHOWS 50 KNOT WINDS AT 925 MB. THIS SHOULD SUSTAIN CONVECTION THROUGH AT LEAST 06Z. AFTER 06Z...RAP GUIDANCE INDICATES 850 MB WINDS WILL VEER WESTERLY AND POTENTIALLY REDUCE STORM INFLOW. EXPECT A DECREASE IN ACTIVITY AFTER 06Z. THE MAIN HAZARDS CONTINUE TO BE ISOLATED LARGE HAIL IN THE STRONGER CORES...AND DAMAGING WINDS ARE LIKELY IN ANY BOWING LINE SEGMENTS. A TORNADO OR TWO IS POSSIBLE AS WELL...ESPECIALLY PRIOR TO THE VEERING OF LOW LEVEL WINDS. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 258 PM CDT THU APR 9 2015 A CAP JUST ABOVE THE LCL SHOULD CONTINUE TO LIMIT THE COVERAGE OF DEEP MOIST CONVECTION ACROSS THE PAH FORECAST AREA THIS AFTERNOON. THERE HAVE BEEN RADAR RETURNS...BUT LITTLE IF ANY MEASURABLE PCPN. THE TROP CONTINUES TO HAVE PRECIPITABLE WATER VALUES NEAR THE 99TH PERCENTILE FOR THIS TIME OF YEAR. DISCRETE ROBUST CONVECTION CANNOT BE RULED OUT THIS AFTERNOON. THE LACK OF A WELL-DEFINED TRIGGER SHOULD VANISH WITH THE ARRIVAL OF A POTENT MID LEVEL SHRTWV AND SFC COLD FRONT THIS EVENING...AS A TIGHT SFC LOW ROCKETS NEWD TOWARD THE GREAT LAKES. MODEST LOW LEVEL INSTABILITY...AT LEAST IN THE EVENING...WILL COMBINE WITH 0-3KM BULK WIND SHEAR IN EXCESS OF 40 KTS FOR THE GENERATION OF SEVERE TSTMS THIS EVENING...PROBABLY IN A SOLID OR BROKEN SQUALL LINE. FORECASTED MID LEVEL LAPSE RATES ARE NOT OFF THE CHARTS...BUT SHOULD NOT LIMIT DEVELOPMENT MUCH. HELICITY VALUES SUGGEST THAT A TORNADO OR TWO MIGHT OCCUR. ATTM...UP TO AN INCH OF RAINFALL IS FORECAST ACROSS THE REGION BEFORE THE EVENT ENDS BY 12Z FRI. THOUGH WE HAVE NOT RECEIVED ANY HEAVY RAIN TODAY...FOR CONSISTENCY`S SAKE...WE WILL LEAVE THE FLOOD WATCH FOR NRN PARTS OF THE AREA IN PLACE THROUGH THE EVENING TO ACCOUNT FOR POTENTIAL CONVECTIVE HEAVY RAINFALL. THE CURRENT AIRMASS WILL BE REPLACED BY A COOLER DRIER ONE OF PACIFIC ORIGIN FOR FRI AND THE FIRST HALF OF THE WEEKEND. THE COOLEST TEMPS SHOULD BE SAT MORNING...BUT NO LOWER THAN ABOUT 40. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 258 PM CDT THU APR 9 2015 MEDIUM CONFIDENCE IN THE EXTENDED. GOOD AGREEMENT EARLY ON IN THE EXTENDED WITH HIGH PRESSURE SLIPPING OFF TO THE EAST AND SOUTHERLY WARM AIR ADVECTION OVER THE HEARTLAND. CANNOT RULE OUT AN ISOLATED SHOWER OR STORM SUNDAY BUT MOST AREAS WILL REMAIN DRY WITH BEST CHANCE OF ANY RAIN WILL BE MAINLY WEST OF THE MISSISSIPPI RIVER. A COLD FRONT APPROACHES SUNDAY NIGHT AND STALLS OVER THE AREA MONDAY INTO TUESDAY. THUS WILL KEEP A CHANCE IN FROM SUNDAY NIGHT THROUGH TUESDAY. WEDNESDAY THE FRONT WILL LIFT BACK TO THE NORTH KEEPING A CHANCE OF THUNDERSTORMS OVER THE AREA. BY THURSDAY WE ARE WARM SECTORED VERY WELL MUCH LIKE THIS MORNING. SO WE COULD SEE SOME ISOLATED SHOWERS OR CLAP OF THUNDER THURSDAY BUT COVERAGE SHOULD BE SLIM. OF COURSE THE FINAL CALL WILL COME AFTER THE EXTENDED INIT IS RUN AND WHAT COLLABORATION YIELDS. TEMPERATURES WILL START OUT BELOW NORMAL SUNDAY THEN RISE TO AROUND 10 DEGREES ABOVE NORMAL FOR NEXT WEEK. && .AVIATION... ISSUED AT 850 PM CDT THU APR 9 2015 THERE WILL CONTINUE TO BE A ROBUST SRLY/SWRLY SFC WIND AHEAD OF A VIGOROUS COLD FRONT THAT IS FORECAST TO SWEEP ACROSS THE REGION AROUND MIDNIGHT. VFR CONDITIONS WILL PREVAIL FOR THE VAST MAJORITY OF THIS TAF PERIOD OUTSIDE OF CONVECTIVE ACTIVITY. INTERMITTENT MVFR CIGS ARE PROBABLE THIS EVENING WITH THE CONVECTION...WITH SEVERE WEATHER POSSIBLE JUST AHEAD OF THE COLD FRONT. WEST WINDS AND VFR CONDITIONS WILL PREVAIL BEHIND THE FRONT. THE WINDS MAY BE GUSTY IN STORMS AS WELL AS IMMEDIATELY BEHIND THE COLD FRONT. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH UNTIL 1 AM CDT FRIDAY FOR ILZ075>078-080>087- 091. MO...FLASH FLOOD WATCH UNTIL 1 AM CDT FRIDAY FOR MOZ076. IN...FLASH FLOOD WATCH UNTIL 1 AM CDT FRIDAY FOR INZ081-082-085>088. KY...FLASH FLOOD WATCH UNTIL 1 AM CDT FRIDAY FOR KYZ010-014>016- 018>021. && $$ UPDATE...MY SHORT TERM...DB LONG TERM...KH AVIATION...MY
AREA FORECAST DISCUSSION
NWS JACKSON KY
814 PM EDT THU APR 9 2015 .UPDATE... ISSUED AT 813 PM EDT THU APR 9 2015 ANOTHER UPDATE TO THE FORECAST GRIDS AND THE ZONE FORECAST TEXT PRODUCT WERE NECESSARY THIS EVENING. BASED ON CURRENT SATELLITE AND RADAR TRENDS...IT APPEARS THAT PRECIPITATION ONSET ACROSS THE AREA WILL OCCUR A FEW HOURS LATER THAN PREVIOUSLY FORECAST. OVER THE PAST HOUR OR SO THERE HAVE BEEN NO SHOWERS OR STORMS PRESENT ACROSS MOST OF CENTRAL AND ALL OF EASTERN KENTUCKY. BASED ON UPSTREAM RADAR RETURNS...IT APPEARS THAT IT WILL BE MUCH LATER TONIGHT BEFORE WIDESPREAD PRECIPITATION BEGINS TO AFFECT THE AREA. THEREFORE...BOTH THE FORECAST GRIDS AND ZONES WERE UPDATED TO REFLECT THIS NEW TREND. THE SAME ISSUES WITH THE STORMS WILL HOLD TRUE...WITH DAMAGING WINDS...LARGE HAIL...AND LOCALLY HEAVY RAINFALL ALL STILL POSSIBLE. A LINE OF STRONG TO POTENTIALLY SEVERE THUNDERSTORMS IS NOW EXPECTED TO MOVE ACROSS THE AREA BETWEEN ROUGHLY 8 AND 13Z ON FRIDAY. THE FLASH FLOOD WATCH IS STILL IN EFFECT. UPDATE ISSUED AT 641 PM EDT THU APR 9 2015 JUST UPDATED THE GRIDS...ZONE FORECAST TEXT PRODUCT...AND HAZARDOUS WEATHER PRODUCT TO ALL REFLECT THE CANCELLATION OF SEVERE THUNDERSTORM WATCH 40. WITH ONLY A FEW MEAGER THUNDERSTORMS HAVING MOVED ACROSS THE AREA SO FAR THIS EVENING...AND WITH NO NEW STORMS EXPECTED TO AFFECT THE AREA ANY TIME SOON...THE WATCH WAS CANCELLED. THE FLASH FLOOD WATCH IS STILL IN EFFECT. THE GRIDS WERE ALSO FRESHENED UP A BIT USING THE LATEST OBS DATA ACROSS THE BOARD. WILL CONTINUE TO MONITOR CURRENT CONDITIONS TO DETERMINE WHEN TO ISSUE THE NEXT FORECAST UPDATE. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 351 PM EDT THU APR 9 2015 MODELS ARE IN GOOD AGREEMENT IN THE SHORT TERM WITH EASTERN KENTUCKY REMAINING UNDER BROAD SW FLOW TODAY BEFORE AN UL TROUGH SWINGS THROUGH THE AREA THIS EVENING. A WARM FRONT REMAINS TO OUR NORTH...HELPING TO FOCUS SOME OF THE MORE INTENSE CONVECTION SO FAR THIS AFTERNOON. HOWEVER...GIVEN THAT THE ATMOSPHERE IS VERY MOIST AND UNSTABLE...THERE IS STILL A CHANCE FOR SCATTERED CONVECTION ACROSS OUR CWA THIS AFTERNOON AND EVENING WITH BEST CHANCES ALONG THE NORTHERN COUNTIES WHERE A SPC SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED. AND AS THE UL TROUGH APPROACHES THE AREA ALLOWING FOR ADDITIONAL HEIGHT FALLS AND UL ENERGY...THE CHANCES FOR THUNDERSTORMS INCREASE. HIGH RES MODELS SUCH AS THE HRRR AND NAM12 BOTH INDICATE A LULL IN CONVECTION TONIGHT AFTER THE DIURNAL CONVECTION WANES AND BEFORE THE COLD FRONT REACHES OUR AREA. AS SUCH...HAVE INDICATED A DECREASE IN SHOWERS/CONVECTION DURING THAT TIME IN THE POP/SKY/WX GRIDS. BY THE TIME THE COLD FRONT REACHES KY AROUND 06Z...SHOWERS AND THUNDERSTORMS WILL BE NUMEROUS AND WIDESPREAD ACROSS THE MAJORITY OF THE STATE. PER LATEST MODEL OUTPUT AND SOUNDINGS...A CONVECTIVE LINE COULD DEVELOP ALONG AND AHEAD OF THE COLD FRONT OVERNIGHT TONIGHT...ALLOWING FOR A THREAT OF HIGH WINDS AND HEAVY RAIN. WILL HAVE TO SEE HOW THE CONVECTION FORMS WITH THE FRONTAL BOUNDARY LATER TONIGHT...BUT IT IS LIKELY THAT THERE WILL BE AT LEAST WIDESPREAD RAINFALL WITH SOME THUNDERSTORMS AS THE FRONT PASSES THROUGH THE REGION TONIGHT. THERE WONT BE THE ADDED BENEFIT OF DAYTIME HEATING BUT THERE WILL BE ENOUGH MID TO UPPER LEVEL SUPPORT FOR CONVECTION TO SUSTAIN ITSELF. THE COLD FRONT SHOULD THEN EXIT EASTERN KY BY 18Z...FOLLOWED QUICKLY BY COOLER...DRIER AIR AND N TO NW FLOW. THE COOLER AIR BEHIND THE FRONT WILL QUICKLY CUT OFF ANY REMAINING SHOWER ACTIVITY AND DRY THE AIR...DECREASING HUMIDITY LEVELS SUBSTANTIALLY. THIS WILL ALLOW FOR TEMPERATURES TO REMAIN NEAR NORMAL VALUES...IN THE MID 60S...ON SATURDAY AS A HIGH PRESSURE SITS OVERHEAD. THIS IS A BIG CHANGE FROM TODAY/S TEMPERATURES WHICH HAVE SURPASSED THE 80 DEGREE MARK FOR THE FIRST TIME THIS YEAR. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 501 PM EDT THU APR 9 2015 A LARGE AREA OF SURFACE HIGH PRESSURE OVER THE OHIO VALLEY ON SATURDAY WILL BRING DRY WEATHER WHICH SHOULD LAST INTO SUNDAY NIGHT. BY THEN THE HIGH WILL BE MOVING OFF THE EAST COAST...AND MODELS SHOW GULF MOISTURE TRYING TO MAKE A RETURN TO THE NORTH AS ANOTHER COLD FRONT PUSHES IN FROM THE NW. IT NOW LOOKS LIKE THIS FRONT WILL BRING A QUICK CHANCE AT SOME SHOWERS ON MONDAY INTO MONDAY NIGHT. MODELS HAVE NOT BEEN CONSISTENT IN THEIR SOLUTIONS FOR TUESDAY THROUGH THURSDAY. THE 12Z RUNS OF BOTH THE GFS AND ECMWF NOW SUGGEST MAINLY DRY WEATHER FOR TUESDAY INTO WEDNESDAY AS HIGH PRESSURE SLIDES BY TO OUR NORTH...AND THE AFOREMENTIONED COLD FRONT STALLS TO OUR SOUTH AND KEEPS MOISTURE AT BAY. HOWEVER...WITH THIS BEING A RECENT CHANGE...HAVE ONLY TRENDED THE POP LOWER INSTEAD OF REMOVING PRECIP FROM THE FORECAST. 12Z RUNS SHOW A RETURN OF GULF MOISTURE FROM WEDNESDAY INTO THURSDAY...BUT LITTLE IN THE WAY OF INSTABILITY AND HAVE CONTINUED CHANCE POPS FOR SHOWERS AT THAT TIME. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 813 PM EDT THU APR 9 2015 VFR CONDITIONS ARE EXPECTED AT THE TAF SITES THROUGH AROUND 6Z TONIGHT. BETWEEN 6 AND 8Z LOOKS TO BE THE TIME FRAME WHEN THE FIRST SHOWERS AND STORMS BEGIN TO APPROACH THE TAF SITES. A LINE OF STRONG TO SEVERE THUNDERSTORMS IS EXPECTED TO MOVE ACROSS THE AREA BETWEEN ROUGHLY 8 AND 13Z. MVFR CONDITIONS WILL PREVAIL DURING MOST OF THIS PERIOD...BUT THERE WILL LIKELY BE SHORT PERIODS OF TIME WHERE THE RAIN AND WIND WILL BE INTENSE ENOUGH TO YIELD IFR AND LIFR CONDITIONS DURING THE STRONGEST STORMS. THE PRECIP SHOULD BEGIN WINDING DOWN AT THE TAF SITES BETWEEN 12 AND 13Z. THE TAF SITES SHOULD BE PRECIP FREE BY BETWEEN 16 AND 18Z. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...AR SHORT TERM...JVM LONG TERM...HAL AVIATION...AR
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
649 PM EDT Wed Apr 8 2015 ...Updated Aviation Discussion... ...Forecast Update... Issued at 525 PM EDT Wed Apr 8 2015 The Severe Thunderstorm Watch has been converted to a Tornado Watch across southern IN and has been extended until 10 PM EDT. Backed low level flow and organized storms along the boundary have led to some cells with significant rotation. Winds, hail, and isolated tornadoes will be possible. South of the watch area, hail will continue to be possible over the next couple of hours. This activity should then diminish later this evening. .SHORT TERM (Now through Thursday Night)... Issued at 308 PM EDT Wed Apr 8 2015 ...More Strong Storms Possible This Evening and Tomorrow... Multiple boundaries have set up across the region this afternoon. SPC mesoanalysis shows all the CIN from earlier in the day has eroded and we have become moderately unstable with 2500-3500 J/kg CAPE. A Severe Thunderstorm Watch has been issued for southern Indiana for this afternoon and early evening. However, given the multiple boundaries and possibility for strong storms elsewhere around the forecast area, extensions to the Watch are not out of the question this afternoon. Large hail and damaging winds will be the main threats this afternoon, though a tornado or two cannot be ruled out completely. The other concern for tonight will be the possibility of training thunderstorms, particularly across southern IN and north central KY. The latest runs of the HRRR have been suggesting this. Given that flash flood values are under an inch an hour and storms may train in this area, have gone ahead and issued a Flash Flood Watch starting late this afternoon and continuing through tomorrow night. There should be a relative lull in the storms for much of the overnight period as any storms that develop this afternoon will move out late this evening. Think another complex associated with a weak upper level wave will move in early tomorrow morning and continue through the morning hours. Some small hail and gusty winds will be possible with these storms. There should be at least a short break in storm coverage tomorrow afternoon ahead of the more significant chance for severe weather along and ahead of the cold front tomorrow night. Moisture will pool ahead of the front with strong southerly winds through the afternoon tomorrow. Forcing will come from the upper level trough moving in and an upper level jet. Shear will increase and hodographs exhibit favorable clockwise curving tomorrow night. A broken line of showers and thunderstorms looks to develop to our west congeal into a line as it moves into the forecast area tomorrow evening. Damaging winds will be the the main threat with the squall line, with a few embedded tornadoes possible. If any cells do develop ahead of the main line hail could be a threat as well. Due to the repeated areas of convection moving across the region, have kept the Flash Flood Watch in place through tomorrow night. Repeated rains will only exacerbate or renew flooding problems. .LONG TERM (Friday through Wednesday)... Issued at 241 PM EDT Wed Apr 8 2015 Not much has changed in the thinking for the long term period. Due to the ongoing storms an updated discussion will not be issued this afternoon. The previous discussion is below. Previous discussion ------------------- Cold front should pass through the area during the pre-dawn hours Friday in our west then sweep across the rest of central Kentucky during the early morning hours. Westerly flow will bring in a drier and quieter pattern Friday night. Plan on a pleasant, sunny and seasonable Saturday with high pressure over the lower Ohio Valley. Sunday will start off in similar fashion but as the high quickly moves to the east, southerly return flow will begin to push another slug of warm, moist air to the region. Shower chances return Sunday night through Monday as a trough digs across the central Plains. High-end chance to likely POPs look reasonable early next week with near normal temperatures. && .AVIATION (00Z TAF Update)... Updated at 645 PM EDT Wed Apr 8 2015 Scattered thunderstorms will continue across north central KY for the next few hours. These storms will continue to affect SDF and LEX off an on. Storms are expected to diminish by 03Z or so with drier conditions for much of the rest of the night. A few showers may develop around BWG over the next few hours, but storms are not expected at this time. The next complex of storms will begin to move in around 11-12Z. These will affect all TAF sites tomorrow morning, moving out early afternoon. Winds will increase tomorrow afternoon as a cold front begins to approach from the west. South-southwesterly winds will be sustained up to around 15 knots with gusts of 20-25 knots. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...FLASH FLOOD WATCH through late Thursday night FOR KYZ023>025- 028>043-045>049-053>057-066-067. IN...FLASH FLOOD WATCH through late Thursday night FOR INZ076>079-083- 084-089>092. && $$ Update.........EER Short Term.....EER Long Term......BJS Aviation.......EER
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
526 PM EDT Wed Apr 8 2015 ...Forecast Update... Issued at 525 PM EDT Wed Apr 8 2015 The Severe Thunderstorm Watch has been converted to a Tornado Watch across southern IN and has been extended until 10 PM EDT. Backed low level flow and organized storms along the boundary have led to some cells with significant rotation. Winds, hail, and isolated tornadoes will be possible. South of the watch area, hail will continue to be possible over the next couple of hours. This activity should then diminish later this evening. .SHORT TERM (Now through Thursday Night)... Issued at 308 PM EDT Wed Apr 8 2015 ...More Strong Storms Possible This Evening and Tomorrow... Multiple boundaries have set up across the region this afternoon. SPC mesoanalysis shows all the CIN from earlier in the day has eroded and we have become moderately unstable with 2500-3500 J/kg CAPE. A Severe Thunderstorm Watch has been issued for southern Indiana for this afternoon and early evening. However, given the multiple boundaries and possibility for strong storms elsewhere around the forecast area, extensions to the Watch are not out of the question this afternoon. Large hail and damaging winds will be the main threats this afternoon, though a tornado or two cannot be ruled out completely. The other concern for tonight will be the possibility of training thunderstorms, particularly across southern IN and north central KY. The latest runs of the HRRR have been suggesting this. Given that flash flood values are under an inch an hour and storms may train in this area, have gone ahead and issued a Flash Flood Watch starting late this afternoon and continuing through tomorrow night. There should be a relative lull in the storms for much of the overnight period as any storms that develop this afternoon will move out late this evening. Think another complex associated with a weak upper level wave will move in early tomorrow morning and continue through the morning hours. Some small hail and gusty winds will be possible with these storms. There should be at least a short break in storm coverage tomorrow afternoon ahead of the more significant chance for severe weather along and ahead of the cold front tomorrow night. Moisture will pool ahead of the front with strong southerly winds through the afternoon tomorrow. Forcing will come from the upper level trough moving in and an upper level jet. Shear will increase and hodographs exhibit favorable clockwise curving tomorrow night. A broken line of showers and thunderstorms looks to develop to our west congeal into a line as it moves into the forecast area tomorrow evening. Damaging winds will be the the main threat with the squall line, with a few embedded tornadoes possible. If any cells do develop ahead of the main line hail could be a threat as well. Due to the repeated areas of convection moving across the region, have kept the Flash Flood Watch in place through tomorrow night. Repeated rains will only exacerbate or renew flooding problems. .LONG TERM (Friday through Wednesday)... Issued at 241 PM EDT Wed Apr 8 2015 Not much has changed in the thinking for the long term period. Due to the ongoing storms an updated discussion will not be issued this afternoon. The previous discussion is below. Previous discussion ------------------- Cold front should pass through the area during the pre-dawn hours Friday in our west then sweep across the rest of central Kentucky during the early morning hours. Westerly flow will bring in a drier and quieter pattern Friday night. Plan on a pleasant, sunny and seasonable Saturday with high pressure over the lower Ohio Valley. Sunday will start off in similar fashion but as the high quickly moves to the east, southerly return flow will begin to push another slug of warm, moist air to the region. Shower chances return Sunday night through Monday as a trough digs across the central Plains. High-end chance to likely POPs look reasonable early next week with near normal temperatures. && .AVIATION (18Z TAF Update)... Updated at 1248 PM EDT Wed Apr 8 2015 Scattered thunderstorms are still expected to develop this afternoon, though have pushed back the timing of VCTS in the TAFs for a couple of hours. There is still a lot of uncertainty in when and where the storms will develop so have kept the VCTS as opposed to introducing TSRA at this time. Those with aviation interests should keep a close eye on the radar this afternoon. Expect a decrease in coverage of storms this evening with much of the night remaining dry at the TAF sites. Another complex looks to move in early tomorrow morning from the west bringing more showers and thunderstorms. These should move out by early afternoon. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...FLASH FLOOD WATCH through late Thursday night FOR KYZ023>025- 028>043-045>049-053>057-066-067. IN...FLASH FLOOD WATCH through late Thursday night FOR INZ076>079-083- 084-089>092. && $$ Update.........EER Short Term.....EER Long Term......BJS Aviation.......EER
AREA FORECAST DISCUSSION
NWS JACKSON KY
522 PM EDT WED APR 8 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 455 PM EDT WED APR 8 2015 THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL SHOW SOUTHWEST FLOW OVER KENTUCKY WITH POCKETS OF ENERGY PASSING THROUGH THE REGION EVERY FEW HOURS. SOME HEIGHT FALLS WILL GET INTO THE MIX ON THURSDAY AS A LARGER TROUGH SWEETS EAST AND INTO THE UPPER MIDWEST. THE KEY TO THIS UNSETTLED PATTERN WILL BE THE SMALLER FEATURES THAT THE HIGHER RES MODELS...SUCH AS THE HRRR/NAM12...HAVE A BETTER CHANCE OF CATCHING. THAT BEING SAID...THE CONFIDENCE IS SOMEWHAT LOW GIVEN THE SMALL SCALE FEATURES AT PLAY. IN TERMS OF SENSIBLE WEATHER IT HAS BEEN QUITE AN ACTIVE DAY ACROSS EASTERN KENTUCKY SO FAR... WITH THE LAST PORTION OF THE MORNING CONVECTION NOW PUSHING OUT OF FAR EASTERN KENTUCKY. BUT THE BIG QUESTION IS...IS HOW THE CONVECTION NOW FORMING IN CENTRAL KENTUCKY WILL SOLIDIFY INTO A COMPLEX AND MOVE EWD... OR IF ADDITIONAL CONVECTION WILL FORM IN EASTERN KENTUCKY AND TRAIN. THE LATEST HRRR INDICATES MULTIPLE AREAS OF CONVECTION FORMING AND MOVING THROUGH OUR FORECAST AREA INTO TOMORROW MORNING....WHEREAS THE NAM12 DOESNT SHOW MUCH OF ANYTHING OVERNIGHT TONIGHT. BUT GIVEN THE CURRENT INSTABILITY PARAMETERS...CURRENT CONVECTION OUT IN CENTRAL KY... AND THE FACT THAT THE HRRR DID A GOOD JOB AT CAPTURING THE DAYTIME CONVECTION... HAVE HEDGED TOWARDS THE HRRR SOLUTION AND INCREASED TO LIKELY POPS IN THE GRIDS THROUGH 03Z. HAVE ALSO ISSUED A FLASH FLOOD WATCH THROUGH 15Z THURSDAY FOR THE THREAT OF TRAINING CONVECTION OVER OUR NORTHERN COUNTIES. THE SET UP FOR ADDITIONAL CONVECTION TOMORROW AFTERNOON INTO FRIDAY MORNING LOOKS SIMILAR TO TODAY...IF NOT BETTER...AS THE TROUGH APPROACHES FROM THE WEST. SO HAVE CONTINUED THE FAIRLY HIGH CHANCES FOR SHOWERS AND STORMS INTO LATE THURSDAY NIGHT/FRIDAY MORNING. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 521 PM EDT WED APR 8 2015 A COLD FRONT WILL BE PASSING SOUTHEAST THROUGH THE REGION AS THE PERIOD STARTS. SHOWERS AND THUNDERSTORMS WILL BE ONGOING AHEAD OF THE FRONT...BUT SHOULD COME TO AN ABRUPT END AFTER FROPA DURING THE DAY. SURFACE HIGH PRESSURE BUILDING IN BEHIND THE FRONT WILL THEN PROVIDE COOLER AND DRIER WEATHER THROUGH AT LEAST SUNDAY. AS THE HIGH SLIPS TO THE EAST...WARM AIR ADVECTION AND A WEAK WARM FRONT TRYING TO DEVELOP WILL PRESENT A LOW PROBABILITY OF SHOWERS SUNDAY NIGHT AND MONDAY. A FEW THUNDERSTORMS COULD SHOW UP ON MONDAY AFTERNOON. A BETTER CHANCE OF RAIN WILL ARRIVE MONDAY NIGHT AND TUESDAY AS A MID/UPPER LEVEL TROUGH PUSHES IN FROM THE WEST ALONG WITH THE FLOW OFF THE GULF. ONCE THIS IMPULSE LIFTS OUT...WE WILL REMAIN IN THE WARM SECTOR. WEAKER DISTURBANCES ALOFT MAY AID SHOWER/THUNDERSTORM DEVELOPMENT AT TIMES TUESDAY NIGHT AND WEDNESDAY...BUT THE TIMING WILL BE NONSPECIFIC AT THIS LONG RANGE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 231 PM EDT WED APR 8 2015 TAIL END OF A THUNDERSTORM COMPLEX IS AFFECTING THE EASTERN EDGE OF THE FORECAST AREA AT THE START OF THE PERIOD. THIS SHOULD EXIT LATE THIS AFTERNOON. ADDITIONAL SHOWERS AND THUNDERSTORMS MAY POP UP...BUT THERE IS LOW CONFIDENCE AS TO TIMING/LOCATION/COVERAGE. ASIDE FROM KSJS...HAVE ONLY USED VCTS IN TAFS THIS AFTERNOON. FORECAST SOUNDINGS SUGGESTED A LESS FAVORABLE LOW LEVEL PROFILE FOR CONVECTION DEVELOPING EARLY THIS EVENING...AND HAVE ALLOWED FOR A BREAK IN CONVECTION DURING THE NIGHT. HOWEVER...THIS IS ONCE AGAIN A LOW CONFIDENCE FORECAST...AND IF ANYTHING DEVELOPS AND SHOWS PROMISE DURING THE NIGHT...THE FORECAST WILL BE SUBJECT TO CHANGE. FORECAST SOUNDINGS SHOW A POTENTIAL FOR SOME THUNDERSTORMS AS DESTABILIZATION OCCURS TOWARD THE END OF THE PERIOD...AND VCTS WAS AGAIN USED. PRECIP MAY BRING IFR...AND COULD ALLOW FOG TO DEVELOP TONIGHT IF THE LOW LEVELS ARE LEFT SATURATED ANYWHERE. HOWEVER...WITHOUT CONFIDENCE IN THIS...HAVE USED PREVAILING VFR. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR KYZ044-050>052- 104. && $$ SHORT TERM...JVM/GREIF LONG TERM...HAL AVIATION...HAL
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
313 PM EDT Wed Apr 8 2015 .SHORT TERM (Now through Thursday Night)... Issued at 308 PM EDT Wed Apr 8 2015 ...More Strong Storms Possible This Evening and Tomorrow... Multiple boundaries have set up across the region this afternoon. SPC mesoanalysis shows all the CIN from earlier in the day has eroded and we have become moderately unstable with 2500-3500 J/kg CAPE. A Severe Thunderstorm Watch has been issued for southern Indiana for this afternoon and early evening. However, given the multiple boundaries and possibility for strong storms elsewhere around the forecast area, extensions to the Watch are not out of the question this afternoon. Large hail and damaging winds will be the main threats this afternoon, though a tornado or two cannot be ruled out completely. The other concern for tonight will be the possibility of training thunderstorms, particularly across southern IN and north central KY. The latest runs of the HRRR have been suggesting this. Given that flash flood values are under an inch an hour and storms may train in this area, have gone ahead and issued a Flash Flood Watch starting late this afternoon and continuing through tomorrow night. There should be a relative lull in the storms for much of the overnight period as any storms that develop this afternoon will move out late this evening. Think another complex associated with a weak upper level wave will move in early tomorrow morning and continue through the morning hours. Some small hail and gusty winds will be possible with these storms. There should be at least a short break in storm coverage tomorrow afternoon ahead of the more significant chance for severe weather along and ahead of the cold front tomorrow night. Moisture will pool ahead of the front with strong southerly winds through the afternoon tomorrow. Forcing will come from the upper level trough moving in and an upper level jet. Shear will increase and hodographs exhibit favorable clockwise curving tomorrow night. A broken line of showers and thunderstorms looks to develop to our west congeal into a line as it moves into the forecast area tomorrow evening. Damaging winds will be the the main threat with the squall line, with a few embedded tornadoes possible. If any cells do develop ahead of the main line hail could be a threat as well. Due to the repeated areas of convection moving across the region, have kept the Flash Flood Watch in place through tomorrow night. Repeated rains will only exacerbate or renew flooding problems. .LONG TERM (Friday through Wednesday)... Issued at 241 PM EDT Wed Apr 8 2015 Not much has changed in the thinking for the long term period. Due to the ongoing storms an updated discussion will not be issued this afternoon. The previous discussion is below. Previous discussion ------------------- Cold front should pass through the area during the pre-dawn hours Friday in our west then sweep across the rest of central Kentucky during the early morning hours. Westerly flow will bring in a drier and quieter pattern Friday night. Plan on a pleasant, sunny and seasonable Saturday with high pressure over the lower Ohio Valley. Sunday will start off in similar fashion but as the high quickly moves to the east, southerly return flow will begin to push another slug of warm, moist air to the region. Shower chances return Sunday night through Monday as a trough digs across the central Plains. High-end chance to likely POPs look reasonable early next week with near normal temperatures. && .AVIATION (18Z TAF Update)... Updated at 1248 PM EDT Wed Apr 8 2015 Scattered thunderstorms are still expected to develop this afternoon, though have pushed back the timing of VCTS in the TAFs for a couple of hours. There is still a lot of uncertainty in when and where the storms will develop so have kept the VCTS as opposed to introducing TSRA at this time. Those with aviation interests should keep a close eye on the radar this afternoon. Expect a decrease in coverage of storms this evening with much of the night remaining dry at the TAF sites. Another complex looks to move in early tomorrow morning from the west bringing more showers and thunderstorms. These should move out by early afternoon. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...FLASH FLOOD WATCH through late Thursday night FOR KYZ023>025- 028>043-045>049-053>057-066-067. IN...FLASH FLOOD WATCH through late Thursday night FOR INZ076>079-083- 084-089>092. && $$ Short Term........EER Long Term.........BJS Aviation..........EER
AREA FORECAST DISCUSSION
NWS JACKSON KY
231 PM EDT WED APR 8 2015 .UPDATE... ISSUED AT 1215 PM EDT WED APR 8 2015 BIGGEST CHANGE TO THE FORECAST WAS INCREASING POPS ALONG THE NORTHERN COUNTIES TO ACCOUNT FOR THE POSSIBLE SOUTHWESTERN EXTENSION OF THE MCS CURRENTLY MOVING ACROSS SOUTHERN OHIO. HAVE INCLUDED LARGE HAIL...DAMAGING WINDS...WITHIN THE WX GRIDS FOR THE NORTHERN COUNTIES THROUGH THIS AFTERNOON TO CORRESPOND WITH THE SPC SEVERE THUNDERSTORM WATCH 32. ADDITIONALLY...UPDATED T AND TD GRIDS TO ALIGN THEM WITH MOST RECENT OBS. SENT UPDATED GRIDS TO WEB SERVERS AND NDFD. UPDATE ISSUED AT 745 AM EDT WED APR 8 2015 THE ARRIVAL OF LOWER CLOUDS FROM THE WEST HAS ALLOWED THE EARLIER DENSE FOG TO BREAK UP AROUND DAWN. ACCORDINGLY...THIS UPDATE WAS MAINLY TO REMOVE THE ADVISORY AND FOG MENTION...BUT ALSO UPDATED THE POPS THROUGH NOON AND ADJUSTED TEMPS/DEW POINTS PER THE LATEST OBS AND TRENDS. THE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS ALONG WITH UPDATES TO THE ZFP AND HWO. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 400 AM EDT WED APR 8 2015 07Z SFC ANALYSIS SHOWS A STATIONARY BOUNDARY JUST NORTH OF KENTUCKY PLACING THE AREA IN A WARM AND HUMID AIR MASS. THE CONVECTION OF THE PAST DAY AND EVENING LEFT PLENTY OF GROUND MOISTURE BEHIND AND NOW THAT CLOUDS ARE CLEARING OFF TO THE EAST...EXPECT WIDESPREAD FOG TO DEVELOP AND BECOME LOCALLY DENSE THIS MORNING. ALREADY JKL...SME...AND LOZ ARE SEEING DENSE FOG. AS A RESULT...A DENSE FOG ADVISORY MAY BE NEEDED FOR MUCH OF THE AREA THROUGH DAWN. OTHERWISE...TEMPERATURES ARE IN THE MID TO UPPER 50S FOR MOST LOCATIONS WHILE DEW POINTS ARE GENERALLY WITHIN A DEGREE OF THE DRY BULB TEMP...ALSO WINDS REMAIN LIGHT AND VARIABLE. THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL SHOW SOUTHWEST FLOW OVER KENTUCKY WITH PACKETS OF ENERGY PASSING THROUGH THE REGION EVERY FEW HOURS. SOME HEIGHT FALLS WILL GET INTO THE MIX LATE IN THE PERIOD ON THURSDAY AS A LARGER TROUGH SWEEPS EAST AND INTO THE UPPER MIDWEST. THE KEY TO THIS UNSETTLED PATTERN WILL BE THE SMALLER FEATURES THAT THE HIGHER RESOLUTION MODELS HAVE A BETTER CHANCE OF CATCHING. EVEN SO...THE CONFIDENCE IN ANY PARTICULAR SOLUTION IS LOW SO THE FORECAST HAS AN ELEMENT OF HEDGING TO IT WITH THE HRRR AND NAM12 FAVORED. THE NAM12 ACTUALLY DID A DECENT JOB DEPICTING THE CONVECTION OF THE PAST DAY SO AM INCLINED TO GIVE IT HIGHER WEIGHTING TODAY. SENSIBLE WEATHER WILL LIKELY BE A REPEAT OF TUESDAY WITH A CLUSTER OF STRONG TO SEVERE THUNDERSTORMS POSSIBLY DEVELOPING BY EARLY AFTERNOON AND TRACKING THROUGH THE NORTHERN AND CENTRAL PORTION OF THE CWA. THIS IS THE SAME PLACE THAT WAS HIT HARD YESTERDAY AND PWS WILL BE SIMILAR TODAY...SO CONSIDERED A FLASH FLOOD WATCH FOR THESE LOCATIONS. HOWEVER...THE UNCERTAINTY IS STILL TOO HIGH BARRING OBVIOUS UPSTREAM DEVELOPMENT SO WILL HIT THIS THREAT WITH AN SPS FOR NOW. THE CONVECTION SHOULD DIE DOWN LATER IN THE EVENING WITH PATCHY FOG...LOCALLY DENSE AGAIN...A CONCERN. THE SET UP REMAINS SIMILAR FOR STORMS ON THURSDAY...IF NOT A TAD BETTER AS THE MAIN TROUGH APPROACHES. ACCORDINGLY...HAVE CONTINUED THE FAIRLY HIGH CHANCES FOR SHOWERS AND STORMS INTO THURSDAY AFTERNOON AND EVENING. AGAIN USED THE SHORTBLEND COMPOSITE MODEL AS A STARTING POINT FOR THE WINDS/T/TD GRIDS THROUGH THE FIRST 18-24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS BASED ON TERRAIN FOR TONIGHT/S TEMPERATURES. AS FOR POPS...ENDED UP CLOSE TO OR A BIT HIGHER THAN A BLEND OF THE MAV AND MET VALUES THROUGH THE PERIOD. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 421 AM EDT WED APR 8 2015 AN UPPER LEVEL TROUGH...WITH SEVERAL SHORTWAVES EMBEDDED AND ROTATING WITHIN IT...WILL PUSH FROM THE UPPER MISSISSIPPI VALLEY EASTWARD FROM 0Z FRIDAY AND THROUGH THE DAY FRIDAY. OVERNIGHT FRIDAY AND INTO THE DAY SATURDAY...THIS WAVE WILL WEAKEN AND CONTINUE TO SHIFT EASTWARD...WHILE BUILDING HEIGHTS AND DEAMPLIFIED RIDGING TAKES HOLD ACROSS THE OHIO RIVER VALLEY. LONG RANGE MODELS ARE IN AGREEMENT OF THIS FLOW BECOMING ZONAL THROUGH SUNDAY...WITH A SHORTWAVE DEVELOPING AND RIDING EASTWARD ACROSS KY LATE IN THE DAY AND CONTINUING INTO MONDAY. UNFORTUNATELY FOR THE REST OF THE EXTENDED...THE FEATURES ARE WELL AGREED UPON...BUT THE TIMING AND PLACEMENT IS NOT. SUNDAY NIGHT/MONDAY MORNING A UPPER LEVEL CLOSED LOW WILL LIKELY DEVELOP OVER THE TX/NM AREA...CAUSING AMPLIFICATION AND EVENTUALLY FALLING HEIGHTS ACROSS KY AS THE LOW STARTS TO MOVE NORTHEASTWARD DURING THE DAY MONDAY...LOSING CONSIDERABLE STRENGTH AS IT REACHES THE UPPER MISSISSIPPI VALLEY BY TUESDAY. MULTIPLE WEAKER SHORTWAVES WILL MOVE AROUND THESE CLOSED LOWS...TRAVELING DIRECTLY INTO THE OHIO RIVER VALLEY. AT THE SURFACE...A LOW PRESSURE SYSTEM WILL BE COLLOCATED WITH THE UPPER LEVEL TROUGH ON FRIDAY AND FOLLOW THE TRACK NORTHEASTWARD ACROSS THE GREAT LAKES. THIS WILL SEND A COLD FRONT EASTWARD AND INTO THE STATE OF KY...STARTING OFF IN THE FAR WEST AROUND 0Z TO 3Z...AND REACHING THE JKL CWA BY LATE MORNING FRIDAY BEFORE QUICKLY SHIFTING EASTWARD IN THE AFTERNOON...JUST AS THE UPPER LEVEL TROUGH EXITS. BEST INSTABILITY AND MOISTURE WILL BE LOCATED ALONG AND JUST AHEAD OF THE FRONT...WITH SHOWERS AND THUNDERSTORMS CHANCES EXPECTED TO INCREASE THROUGH FRIDAY MORNING...BEFORE QUICKLY TAPERING OFF ONCE THE FRONT PASSES THROUGH AND A STRONG SHOT OF DRIER AND COOLER NRLY FLOW MOVES IN. AS HEIGHTS BUILD SATURDAY INTO SATURDAY NIGHT...EXPECT SURFACE HIGH PRESSURE TO BE IN CHARGE...WITH LIGHT WINDS AND GENERALLY CLEAR SKIES. THE COULD CREATE SOME RIDGE VALLEY SPLIT CONDITIONS FOR OVERNIGHT LOWS...AS WAS REFLECTED IN THE FORECAST. BY SUNDAY...THE NEXT SHORTWAVE WILL BEGIN ENCROACHING UPON THE REGION...WITH YET ANOTHER SURFACE LOW LOCATED JUST TO OUR SW. STRONG SRLY FLOW WILL TAKE HOLD...WHICH COUPLED WITH INSTABILITY/LIFT FROM THE NEARBY SYSTEM...WILL CREATE ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS SUNDAY EVENING AND INTO THE DAY MONDAY. FINALLY...THE FUN CONTINUES AS SEVERAL MORE SHORTWAVES TRAVERSE THE UPPER LEVEL TROUGH AND BRING UNSETTLED WEATHER TO THE REGION TO CONTINUE OUT THE REMAINDER OF THE EXTENDED. GIVEN THE TIMING AND PLACEMENT DISCREPANCIES OF THE LONG RANGE MODELS...CONTINUED WITH A MODEL BLEND AT THIS TIME. HOWEVER...ONE NOTE...IF THE GFS40 MODEL PANS OUT...SOME OF THESE SYSTEMS COULD PUT DOWN SOME HEAVY RAINS...WITH PWATS TOPPING OUT ABOVE 1.3 TUESDAY AFTERNOON AND EVENING. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 231 PM EDT WED APR 8 2015 TAIL END OF A THUNDERSTORM COMPLEX IS AFFECTING THE EASTERN EDGE OF THE FORECAST AREA AT THE START OF THE PERIOD. THIS SHOULD EXIT LATE THIS AFTERNOON. ADDITIONAL SHOWERS AND THUNDERSTORMS MAY POP UP...BUT THERE IS LOW CONFIDENCE AS TO TIMING/LOCATION/COVERAGE. ASIDE FROM KSJS...HAVE ONLY USED VCTS IN TAFS THIS AFTERNOON. FORECAST SOUNDINGS SUGGESTED A LESS FAVORABLE LOW LEVEL PROFILE FOR CONVECTION DEVELOPING EARLY THIS EVENING...AND HAVE ALLOWED FOR A BREAK IN CONVECTION DURING THE NIGHT. HOWEVER...THIS IS ONCE AGAIN A LOW CONFIDENCE FORECAST...AND IF ANYTHING DEVELOPS AND SHOWS PROMISE DURING THE NIGHT...THE FORECAST WILL BE SUBJECT TO CHANGE. FORECAST SOUNDINGS SHOW A POTENTIAL FOR SOME THUNDERSTORMS AS DESTABILIZATION OCCURS TOWARD THE END OF THE PERIOD...AND VCTS WAS AGAIN USED. PRECIP MAY BRING IFR...AND COULD ALLOW FOG TO DEVELOP TONIGHT IF THE LOW LEVELS ARE LEFT SATURATED ANYWHERE. HOWEVER...WITHOUT CONFIDENCE IN THIS...HAVE USED PREVAILING VFR. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JVM SHORT TERM...GREIF LONG TERM...JMW AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
218 PM EDT WED APR 8 2015 .UPDATE... ISSUED AT 218 PM EDT WED APR 8 2015 DID A QUICK DATA LOAD AND BLEND TO UPDATE GRIDS WITH MOST RECENT OBS. ALSO ADJUSTED POPS/SKY PER LATEST TRENDS WITH MCS THAT CONTINUES TO PUSH ESE. UPDATE ISSUED AT 1215 PM EDT WED APR 8 2015 BIGGEST CHANGE TO THE FORECAST WAS INCREASING POPS ALONG THE NORTHERN COUNTIES TO ACCOUNT FOR THE POSSIBLE SOUTHWESTERN EXTENSION OF THE MCS CURRENTLY MOVING ACROSS SOUTHERN OHIO. HAVE INCLUDED LARGE HAIL...DAMAGING WINDS...WITHIN THE WX GRIDS FOR THE NORTHERN COUNTIES THROUGH THIS AFTERNOON TO CORRESPOND WITH THE SPC SEVERE THUNDERSTORM WATCH 32. ADDITIONALLY...UPDATED T AND TD GRIDS TO ALIGN THEM WITH MOST RECENT OBS. SENT UPDATED GRIDS TO WEB SERVERS AND NDFD. UPDATE ISSUED AT 745 AM EDT WED APR 8 2015 THE ARRIVAL OF LOWER CLOUDS FROM THE WEST HAS ALLOWED THE EARLIER DENSE FOG TO BREAK UP AROUND DAWN. ACCORDINGLY...THIS UPDATE WAS MAINLY TO REMOVE THE ADVISORY AND FOG MENTION...BUT ALSO UPDATED THE POPS THROUGH NOON AND ADJUSTED TEMPS/DEWPOINTS PER THE LATEST OBS AND TRENDS. THE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS ALONG WITH UPDATES TO THE ZFP AND HWO. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 400 AM EDT WED APR 8 2015 07Z SFC ANALYSIS SHOWS A STATIONARY BOUNDARY JUST NORTH OF KENTUCKY PLACING THE AREA IN A WARM AND HUMID AIR MASS. THE CONVECTION OF THE PAST DAY AND EVENING LEFT PLENTY OF GROUND MOISTURE BEHIND AND NOW THAT CLOUDS ARE CLEARING OFF TO THE EAST...EXPECT WIDESPREAD FOG TO DEVELOP AND BECOME LOCALLY DENSE THIS MORNING. ALREADY JKL...SME...AND LOZ ARE SEEING DENSE FOG. AS A RESULT...A DENSE FOG ADVISORY MAY BE NEEDED FOR MUCH OF THE AREA THROUGH DAWN. OTHERWISE...TEMPERATURES ARE IN THE MID TO UPPER 50S FOR MOST LOCATIONS WHILE DEWPOINTS ARE GENERALLY WITHIN A DEGREE OF THE DRY BULB TEMP...ALSO WINDS REMAIN LIGHT AND VARIABLE. THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL SHOW SOUTHWEST FLOW OVER KENTUCKY WITH PACKETS OF ENERGY PASSING THROUGH THE REGION EVERY FEW HOURS. SOME HEIGHT FALLS WILL GET INTO THE MIX LATE IN THE PERIOD ON THURSDAY AS A LARGER TROUGH SWEEPS EAST AND INTO THE UPPER MIDWEST. THE KEY TO THIS UNSETTLED PATTERN WILL BE THE SMALLER FEATURES THAT THE HIGHER RESOLUTION MODELS HAVE A BETTER CHANCE OF CATCHING. EVEN SO...THE CONFIDENCE IN ANY PARTICULAR SOLUTION IS LOW SO THE FORECAST HAS AN ELEMENT OF HEDGING TO IT WITH THE HRRR AND NAM12 FAVORED. THE NAM12 ACTUALLY DID A DECENT JOB DEPICTING THE CONVECTION OF THE PAST DAY SO AM INCLINED TO GIVE IT HIGHER WEIGHTING TODAY. SENSIBLE WEATHER WILL LIKELY BE A REPEAT OF TUESDAY WITH A CLUSTER OF STRONG TO SEVERE THUNDERSTORMS POSSIBLY DEVELOPING BY EARLY AFTERNOON AND TRACKING THROUGH THE NORTHERN AND CENTRAL PORTION OF THE CWA. THIS IS THE SAME PLACE THAT WAS HIT HARD YESTERDAY AND PWS WILL BE SIMILAR TODAY...SO CONSIDERED A FLASH FLOOD WATCH FOR THESE LOCATIONS. HOWEVER...THE UNCERTAINTY IS STILL TOO HIGH BARRING OBVIOUS UPSTREAM DEVELOPMENT SO WILL HIT THIS THREAT WITH AN SPS FOR NOW. THE CONVECTION SHOULD DIE DOWN LATER IN THE EVENING WITH PATCHY FOG...LOCALLY DENSE AGAIN...A CONCERN. THE SET UP REMAINS SIMILAR FOR STORMS ON THURSDAY...IF NOT A TAD BETTER AS THE MAIN TROUGH APPROACHES. ACCORDINGLY...HAVE CONTINUED THE FAIRLY HIGH CHANCES FOR SHOWERS AND STORMS INTO THURSDAY AFTERNOON AND EVENING. AGAIN USED THE SHORTBLEND COMPOSITE MODEL AS A STARTING POINT FOR THE WINDS/T/TD GRIDS THROUGH THE FIRST 18-24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS BASED ON TERRAIN FOR TONIGHT/S TEMPERATURES. AS FOR POPS...ENDED UP CLOSE TO OR A BIT HIGHER THAN A BLEND OF THE MAV AND MET VALUES THROUGH THE PERIOD. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 421 AM EDT WED APR 8 2015 AN UPPER LEVEL TROUGH...WITH SEVERAL SHORTWAVES EMBEDDED AND ROTATING WITHIN IT...WILL PUSH FROM THE UPPER MISSISSIPPI VALLEY EASTWARD FROM 0Z FRIDAY AND THROUGH THE DAY FRIDAY. OVERNIGHT FRIDAY AND INTO THE DAY SATURDAY...THIS WAVE WILL WEAKEN AND CONTINUE TO SHIFT EASTWARD...WHILE BUILDING HEIGHTS AND DEAMPLIFIED RIDGING TAKES HOLD ACROSS THE OHIO RIVER VALLEY. LONG RANGE MODELS ARE IN AGREEMENT OF THIS FLOW BECOMING ZONAL THROUGH SUNDAY...WITH A SHORTWAVE DEVELOPING AND RIDING EASTWARD ACROSS KY LATE IN THE DAY AND CONTINUING INTO MONDAY. UNFORTUNATELY FOR THE REST OF THE EXTENDED...THE FEATURES ARE WELL AGREED UPON...BUT THE TIMING AND PLACEMENT IS NOT. SUNDAY NIGHT/MONDAY MORNING A UPPER LEVEL CLOSED LOW WILL LIKELY DEVELOP OVER THE TX/NM AREA...CAUSING AMPLIFICATION AND EVENTUALLY FALLING HEIGHTS ACROSS KY AS THE LOW STARTS TO MOVE NEWARD DURING THE DAY MONDAY...LOSING CONSIDERABLE STRENGTH AS IT REACHES THE UPPER MISSISSIPPI VALLEY BY TUESDAY. MULTIPLE WEAKER SHORTWAVES WILL MOVE AROUND THESE CLOSED LOWS...TRAVELING DIRECTLY INTO THE OHIO RIVER VALLEY. AT THE SURFACE...A LOW PRESSURE SYSTEM WILL BE COLLOCATED WITH THE UPPER LEVEL TROUGH ON FRIDAY AND FOLLOW THE TRACK NORTHEASTWARD ACROSS THE GREAT LAKES. THIS WILL SEND A COLD FRONT EASTWARD AND INTO THE STATE OF KY...STARTING OFF IN THE FAR WEST AROUND 0Z TO 3Z...AND REACHING THE JKL CWA BY LATE MORNING FRIDAY BEFORE QUICKLY SHIFTING EASTWARD IN THE AFTERNOON...JUST AS THE UPPER LEVEL TROUGH EXITS. BEST INSTABILITY AND MOISTURE WILL BE LOCATED ALONG AND JUST AHEAD OF THE FRONT...WITH SHOWERS AND THUNDERSTORMS CHANCES EXPECTED TO INCREASE THROUGH FRIDAY MORNING...BEFORE QUICKLY TAPERING OFF ONCE THE FRONT PASSES THROUGH AND A STRONG SHOT OF DRIER AND COOLER NRLY FLOW MOVES IN. AS HEIGHTS BUILD SATURDAY INTO SATURDAY NIGHT...EXPECT SURFACE HIGH PRESSURE TO BE IN CHARGE...WITH LIGHT WINDS AND GENERALLY CLEAR SKIES. THE COULD CREATE SOME RIDGE VALLEY SPLIT CONDITIONS FOR OVERNIGHT LOWS...AS WAS REFLECTED IN THE FORECAST. BY SUNDAY...THE NEXT SHORTWAVE WILL BEGIN ENCROACHING UPON THE REGION...WITH YET ANOTHER SURFACE LOW LOCATED JUST TO OUR SW. STRONG SRLY FLOW WILL TAKE HOLD...WHICH COUPLED WITH INSTABILITY/LIFT FROM THE NEARBY SYSTEM...WILL CREATE ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS SUNDAY EVENING AND INTO THE DAY MONDAY. FINALLY...THE FUN CONTINUES AS SEVERAL MORE SHORTWAVES TRAVERSE THE UPPER LEVEL TROUGH AND BRING UNSETTLED WEATHER TO THE REGION TO CONTINUE OUT THE REMAINDER OF THE EXTENDED. GIVEN THE TIMING AND PLACEMENT DISCREPANCIES OF THE LONG RANGE MODELS...CONTINUED WITH A MODEL BLEND AT THIS TIME. HOWEVER...ONE NOTE...IF THE GFS40 MODEL PANS OUT...SOME OF THESE SYSTEMS COULD PUT DOWN SOME HEAVY RAINS...WITH PWATS TOPPING OUT ABOVE 1.3 TUESDAY AFTERNOON AND EVENING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 800 AM EDT WED APR 8 2015 THE FOG PROVED TO BE FLEETING THIS MORNING AS A LAYER OF LOW TO MID CLOUDS MOVED IN AND CLEARED OUT THE LOWER VIS. LATER TODAY ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED THIS AFTERNOON. HAVE STAYED WITH A VCTS FOR THIS WITH MORE REFINEMENT POSSIBLE WITH FUTURE TAF ISSUANCES AS THE TIMING AND EFFECTS OF THIS NEXT WAVE BECOME MORE CLEAR. AFTER THIS WAVE OF ACTIVITY PASSES PATCHY FOG WILL BE A POSSIBILITY MAINLY...IN THE VALLEYS...AND HAVE ADDED SOME TO THE SME AND LOZ TAFS. WINDS WILL REMAIN MAINLY LIGHT FROM THE SOUTH...OUTSIDE OF ANY THUNDERSTORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JVM SHORT TERM...GREIF LONG TERM...JMW AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
1213 PM EDT WED APR 8 2015 .UPDATE... ISSUED AT 1215 PM EDT WED APR 8 2015 BIGGEST CHANGE TO THE FORECAST WAS INCREASING POPS ALONG THE NORTHERN COUNTIES TO ACCOUNT FOR THE POSSIBLE SOUTHWESTERN EXTENSION OF THE MCS CURRENTLY MOVING ACROSS SOUTHERN OHIO. HAVE INCLUDED LARGE HAIL...DAMAGING WINDS...WITHIN THE WX GRIDS FOR THE NORTHERN COUNTIES THROUGH THIS AFTERNOON TO CORRESPOND WITH THE SPC SEVERE THUNDERSTORM WATCH 32. ADDITIONALLY...UPDATED T AND TD GRIDS TO ALIGN THEM WITH MOST RECENT OBS. SENT UPDATED GRIDS TO WEB SERVERS AND NDFD. UPDATE ISSUED AT 745 AM EDT WED APR 8 2015 THE ARRIVAL OF LOWER CLOUDS FROM THE WEST HAS ALLOWED THE EARLIER DENSE FOG TO BREAK UP AROUND DAWN. ACCORDINGLY...THIS UPDATE WAS MAINLY TO REMOVE THE ADVISORY AND FOG MENTION...BUT ALSO UPDATED THE POPS THROUGH NOON AND ADJUSTED TEMPS/DEWPOINTS PER THE LATEST OBS AND TRENDS. THE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS ALONG WITH UPDATES TO THE ZFP AND HWO. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 400 AM EDT WED APR 8 2015 07Z SFC ANALYSIS SHOWS A STATIONARY BOUNDARY JUST NORTH OF KENTUCKY PLACING THE AREA IN A WARM AND HUMID AIR MASS. THE CONVECTION OF THE PAST DAY AND EVENING LEFT PLENTY OF GROUND MOISTURE BEHIND AND NOW THAT CLOUDS ARE CLEARING OFF TO THE EAST...EXPECT WIDESPREAD FOG TO DEVELOP AND BECOME LOCALLY DENSE THIS MORNING. ALREADY JKL...SME...AND LOZ ARE SEEING DENSE FOG. AS A RESULT...A DENSE FOG ADVISORY MAY BE NEEDED FOR MUCH OF THE AREA THROUGH DAWN. OTHERWISE...TEMPERATURES ARE IN THE MID TO UPPER 50S FOR MOST LOCATIONS WHILE DEWPOINTS ARE GENERALLY WITHIN A DEGREE OF THE DRY BULB TEMP...ALSO WINDS REMAIN LIGHT AND VARIABLE. THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL SHOW SOUTHWEST FLOW OVER KENTUCKY WITH PACKETS OF ENERGY PASSING THROUGH THE REGION EVERY FEW HOURS. SOME HEIGHT FALLS WILL GET INTO THE MIX LATE IN THE PERIOD ON THURSDAY AS A LARGER TROUGH SWEEPS EAST AND INTO THE UPPER MIDWEST. THE KEY TO THIS UNSETTLED PATTERN WILL BE THE SMALLER FEATURES THAT THE HIGHER RESOLUTION MODELS HAVE A BETTER CHANCE OF CATCHING. EVEN SO...THE CONFIDENCE IN ANY PARTICULAR SOLUTION IS LOW SO THE FORECAST HAS AN ELEMENT OF HEDGING TO IT WITH THE HRRR AND NAM12 FAVORED. THE NAM12 ACTUALLY DID A DECENT JOB DEPICTING THE CONVECTION OF THE PAST DAY SO AM INCLINED TO GIVE IT HIGHER WEIGHTING TODAY. SENSIBLE WEATHER WILL LIKELY BE A REPEAT OF TUESDAY WITH A CLUSTER OF STRONG TO SEVERE THUNDERSTORMS POSSIBLY DEVELOPING BY EARLY AFTERNOON AND TRACKING THROUGH THE NORTHERN AND CENTRAL PORTION OF THE CWA. THIS IS THE SAME PLACE THAT WAS HIT HARD YESTERDAY AND PWS WILL BE SIMILAR TODAY...SO CONSIDERED A FLASH FLOOD WATCH FOR THESE LOCATIONS. HOWEVER...THE UNCERTAINTY IS STILL TOO HIGH BARRING OBVIOUS UPSTREAM DEVELOPMENT SO WILL HIT THIS THREAT WITH AN SPS FOR NOW. THE CONVECTION SHOULD DIE DOWN LATER IN THE EVENING WITH PATCHY FOG...LOCALLY DENSE AGAIN...A CONCERN. THE SET UP REMAINS SIMILAR FOR STORMS ON THURSDAY...IF NOT A TAD BETTER AS THE MAIN TROUGH APPROACHES. ACCORDINGLY...HAVE CONTINUED THE FAIRLY HIGH CHANCES FOR SHOWERS AND STORMS INTO THURSDAY AFTERNOON AND EVENING. AGAIN USED THE SHORTBLEND COMPOSITE MODEL AS A STARTING POINT FOR THE WINDS/T/TD GRIDS THROUGH THE FIRST 18-24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS BASED ON TERRAIN FOR TONIGHT/S TEMPERATURES. AS FOR POPS...ENDED UP CLOSE TO OR A BIT HIGHER THAN A BLEND OF THE MAV AND MET VALUES THROUGH THE PERIOD. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 421 AM EDT WED APR 8 2015 AN UPPER LEVEL TROUGH...WITH SEVERAL SHORTWAVES EMBEDDED AND ROTATING WITHIN IT...WILL PUSH FROM THE UPPER MISSISSIPPI VALLEY EASTWARD FROM 0Z FRIDAY AND THROUGH THE DAY FRIDAY. OVERNIGHT FRIDAY AND INTO THE DAY SATURDAY...THIS WAVE WILL WEAKEN AND CONTINUE TO SHIFT EASTWARD...WHILE BUILDING HEIGHTS AND DEAMPLIFIED RIDGING TAKES HOLD ACROSS THE OHIO RIVER VALLEY. LONG RANGE MODELS ARE IN AGREEMENT OF THIS FLOW BECOMING ZONAL THROUGH SUNDAY...WITH A SHORTWAVE DEVELOPING AND RIDING EASTWARD ACROSS KY LATE IN THE DAY AND CONTINUING INTO MONDAY. UNFORTUNATELY FOR THE REST OF THE EXTENDED...THE FEATURES ARE WELL AGREED UPON...BUT THE TIMING AND PLACEMENT IS NOT. SUNDAY NIGHT/MONDAY MORNING A UPPER LEVEL CLOSED LOW WILL LIKELY DEVELOP OVER THE TX/NM AREA...CAUSING AMPLIFICATION AND EVENTUALLY FALLING HEIGHTS ACROSS KY AS THE LOW STARTS TO MOVE NEWARD DURING THE DAY MONDAY...LOSING CONSIDERABLE STRENGTH AS IT REACHES THE UPPER MISSISSIPPI VALLEY BY TUESDAY. MULTIPLE WEAKER SHORTWAVES WILL MOVE AROUND THESE CLOSED LOWS...TRAVELING DIRECTLY INTO THE OHIO RIVER VALLEY. AT THE SURFACE...A LOW PRESSURE SYSTEM WILL BE COLLOCATED WITH THE UPPER LEVEL TROUGH ON FRIDAY AND FOLLOW THE TRACK NORTHEASTWARD ACROSS THE GREAT LAKES. THIS WILL SEND A COLD FRONT EASTWARD AND INTO THE STATE OF KY...STARTING OFF IN THE FAR WEST AROUND 0Z TO 3Z...AND REACHING THE JKL CWA BY LATE MORNING FRIDAY BEFORE QUICKLY SHIFTING EASTWARD IN THE AFTERNOON...JUST AS THE UPPER LEVEL TROUGH EXITS. BEST INSTABILITY AND MOISTURE WILL BE LOCATED ALONG AND JUST AHEAD OF THE FRONT...WITH SHOWERS AND THUNDERSTORMS CHANCES EXPECTED TO INCREASE THROUGH FRIDAY MORNING...BEFORE QUICKLY TAPERING OFF ONCE THE FRONT PASSES THROUGH AND A STRONG SHOT OF DRIER AND COOLER NRLY FLOW MOVES IN. AS HEIGHTS BUILD SATURDAY INTO SATURDAY NIGHT...EXPECT SURFACE HIGH PRESSURE TO BE IN CHARGE...WITH LIGHT WINDS AND GENERALLY CLEAR SKIES. THE COULD CREATE SOME RIDGE VALLEY SPLIT CONDITIONS FOR OVERNIGHT LOWS...AS WAS REFLECTED IN THE FORECAST. BY SUNDAY...THE NEXT SHORTWAVE WILL BEGIN ENCROACHING UPON THE REGION...WITH YET ANOTHER SURFACE LOW LOCATED JUST TO OUR SW. STRONG SRLY FLOW WILL TAKE HOLD...WHICH COUPLED WITH INSTABILITY/LIFT FROM THE NEARBY SYSTEM...WILL CREATE ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS SUNDAY EVENING AND INTO THE DAY MONDAY. FINALLY...THE FUN CONTINUES AS SEVERAL MORE SHORTWAVES TRAVERSE THE UPPER LEVEL TROUGH AND BRING UNSETTLED WEATHER TO THE REGION TO CONTINUE OUT THE REMAINDER OF THE EXTENDED. GIVEN THE TIMING AND PLACEMENT DISCREPANCIES OF THE LONG RANGE MODELS...CONTINUED WITH A MODEL BLEND AT THIS TIME. HOWEVER...ONE NOTE...IF THE GFS40 MODEL PANS OUT...SOME OF THESE SYSTEMS COULD PUT DOWN SOME HEAVY RAINS...WITH PWATS TOPPING OUT ABOVE 1.3 TUESDAY AFTERNOON AND EVENING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 800 AM EDT WED APR 8 2015 THE FOG PROVED TO BE FLEETING THIS MORNING AS A LAYER OF LOW TO MID CLOUDS MOVED IN AND CLEARED OUT THE LOWER VIS. LATER TODAY ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED THIS AFTERNOON. HAVE STAYED WITH A VCTS FOR THIS WITH MORE REFINEMENT POSSIBLE WITH FUTURE TAF ISSUANCES AS THE TIMING AND EFFECTS OF THIS NEXT WAVE BECOME MORE CLEAR. AFTER THIS WAVE OF ACTIVITY PASSES PATCHY FOG WILL BE A POSSIBILITY MAINLY...IN THE VALLEYS...AND HAVE ADDED SOME TO THE SME AND LOZ TAFS. WINDS WILL REMAIN MAINLY LIGHT FROM THE SOUTH...OUTSIDE OF ANY THUNDERSTORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JVM SHORT TERM...GREIF LONG TERM...JMW AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
800 AM EDT WED APR 8 2015 .UPDATE... ISSUED AT 745 AM EDT WED APR 8 2015 THE ARRIVAL OF LOWER CLOUDS FROM THE WEST HAS ALLOWED THE EARLIER DENSE FOG TO BREAK UP AROUND DAWN. ACCORDINGLY...THIS UPDATE WAS MAINLY TO REMOVE THE ADVISORY AND FOG MENTION...BUT ALSO UPDATED THE POPS THROUGH NOON AND ADJUSTED TEMPS/DEWPOINTS PER THE LATEST OBS AND TRENDS. THE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS ALONG WITH UPDATES TO THE ZFP AND HWO. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 400 AM EDT WED APR 8 2015 07Z SFC ANALYSIS SHOWS A STATIONARY BOUNDARY JUST NORTH OF KENTUCKY PLACING THE AREA IN A WARM AND HUMID AIR MASS. THE CONVECTION OF THE PAST DAY AND EVENING LEFT PLENTY OF GROUND MOISTURE BEHIND AND NOW THAT CLOUDS ARE CLEARING OFF TO THE EAST...EXPECT WIDESPREAD FOG TO DEVELOP AND BECOME LOCALLY DENSE THIS MORNING. ALREADY JKL...SME...AND LOZ ARE SEEING DENSE FOG. AS A RESULT...A DENSE FOG ADVISORY MAY BE NEEDED FOR MUCH OF THE AREA THROUGH DAWN. OTHERWISE...TEMPERATURES ARE IN THE MID TO UPPER 50S FOR MOST LOCATIONS WHILE DEWPOINTS ARE GENERALLY WITHIN A DEGREE OF THE DRY BULB TEMP...ALSO WINDS REMAIN LIGHT AND VARIABLE. THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL SHOW SOUTHWEST FLOW OVER KENTUCKY WITH PACKETS OF ENERGY PASSING THROUGH THE REGION EVERY FEW HOURS. SOME HEIGHT FALLS WILL GET INTO THE MIX LATE IN THE PERIOD ON THURSDAY AS A LARGER TROUGH SWEEPS EAST AND INTO THE UPPER MIDWEST. THE KEY TO THIS UNSETTLED PATTERN WILL BE THE SMALLER FEATURES THAT THE HIGHER RESOLUTION MODELS HAVE A BETTER CHANCE OF CATCHING. EVEN SO...THE CONFIDENCE IN ANY PARTICULAR SOLUTION IS LOW SO THE FORECAST HAS AN ELEMENT OF HEDGING TO IT WITH THE HRRR AND NAM12 FAVORED. THE NAM12 ACTUALLY DID A DECENT JOB DEPICTING THE CONVECTION OF THE PAST DAY SO AM INCLINED TO GIVE IT HIGHER WEIGHTING TODAY. SENSIBLE WEATHER WILL LIKELY BE A REPEAT OF TUESDAY WITH A CLUSTER OF STRONG TO SEVERE THUNDERSTORMS POSSIBLY DEVELOPING BY EARLY AFTERNOON AND TRACKING THROUGH THE NORTHERN AND CENTRAL PORTION OF THE CWA. THIS IS THE SAME PLACE THAT WAS HIT HARD YESTERDAY AND PWS WILL BE SIMILAR TODAY...SO CONSIDERED A FLASH FLOOD WATCH FOR THESE LOCATIONS. HOWEVER...THE UNCERTAINTY IS STILL TOO HIGH BARRING OBVIOUS UPSTREAM DEVELOPMENT SO WILL HIT THIS THREAT WITH AN SPS FOR NOW. THE CONVECTION SHOULD DIE DOWN LATER IN THE EVENING WITH PATCHY FOG...LOCALLY DENSE AGAIN...A CONCERN. THE SET UP REMAINS SIMILAR FOR STORMS ON THURSDAY...IF NOT A TAD BETTER AS THE MAIN TROUGH APPROACHES. ACCORDINGLY...HAVE CONTINUED THE FAIRLY HIGH CHANCES FOR SHOWERS AND STORMS INTO THURSDAY AFTERNOON AND EVENING. AGAIN USED THE SHORTBLEND COMPOSITE MODEL AS A STARTING POINT FOR THE WINDS/T/TD GRIDS THROUGH THE FIRST 18-24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS BASED ON TERRAIN FOR TONIGHT/S TEMPERATURES. AS FOR POPS...ENDED UP CLOSE TO OR A BIT HIGHER THAN A BLEND OF THE MAV AND MET VALUES THROUGH THE PERIOD. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 421 AM EDT WED APR 8 2015 AN UPPER LEVEL TROUGH...WITH SEVERAL SHORTWAVES EMBEDDED AND ROTATING WITHIN IT...WILL PUSH FROM THE UPPER MISSISSIPPI VALLEY EASTWARD FROM 0Z FRIDAY AND THROUGH THE DAY FRIDAY. OVERNIGHT FRIDAY AND INTO THE DAY SATURDAY...THIS WAVE WILL WEAKEN AND CONTINUE TO SHIFT EASTWARD...WHILE BUILDING HEIGHTS AND DEAMPLIFIED RIDGING TAKES HOLD ACROSS THE OHIO RIVER VALLEY. LONG RANGE MODELS ARE IN AGREEMENT OF THIS FLOW BECOMING ZONAL THROUGH SUNDAY...WITH A SHORTWAVE DEVELOPING AND RIDING EASTWARD ACROSS KY LATE IN THE DAY AND CONTINUING INTO MONDAY. UNFORTUNATELY FOR THE REST OF THE EXTENDED...THE FEATURES ARE WELL AGREED UPON...BUT THE TIMING AND PLACEMENT IS NOT. SUNDAY NIGHT/MONDAY MORNING A UPPER LEVEL CLOSED LOW WILL LIKELY DEVELOP OVER THE TX/NM AREA...CAUSING AMPLIFICATION AND EVENTUALLY FALLING HEIGHTS ACROSS KY AS THE LOW STARTS TO MOVE NEWARD DURING THE DAY MONDAY...LOSING CONSIDERABLE STRENGTH AS IT REACHES THE UPPER MISSISSIPPI VALLEY BY TUESDAY. MULTIPLE WEAKER SHORTWAVES WILL MOVE AROUND THESE CLOSED LOWS...TRAVELING DIRECTLY INTO THE OHIO RIVER VALLEY. AT THE SURFACE...A LOW PRESSURE SYSTEM WILL BE COLLOCATED WITH THE UPPER LEVEL TROUGH ON FRIDAY AND FOLLOW THE TRACK NORTHEASTWARD ACROSS THE GREAT LAKES. THIS WILL SEND A COLD FRONT EASTWARD AND INTO THE STATE OF KY...STARTING OFF IN THE FAR WEST AROUND 0Z TO 3Z...AND REACHING THE JKL CWA BY LATE MORNING FRIDAY BEFORE QUICKLY SHIFTING EASTWARD IN THE AFTERNOON...JUST AS THE UPPER LEVEL TROUGH EXITS. BEST INSTABILITY AND MOISTURE WILL BE LOCATED ALONG AND JUST AHEAD OF THE FRONT...WITH SHOWERS AND THUNDERSTORMS CHANCES EXPECTED TO INCREASE THROUGH FRIDAY MORNING...BEFORE QUICKLY TAPERING OFF ONCE THE FRONT PASSES THROUGH AND A STRONG SHOT OF DRIER AND COOLER NRLY FLOW MOVES IN. AS HEIGHTS BUILD SATURDAY INTO SATURDAY NIGHT...EXPECT SURFACE HIGH PRESSURE TO BE IN CHARGE...WITH LIGHT WINDS AND GENERALLY CLEAR SKIES. THE COULD CREATE SOME RIDGE VALLEY SPLIT CONDITIONS FOR OVERNIGHT LOWS...AS WAS REFLECTED IN THE FORECAST. BY SUNDAY...THE NEXT SHORTWAVE WILL BEGIN ENCROACHING UPON THE REGION...WITH YET ANOTHER SURFACE LOW LOCATED JUST TO OUR SW. STRONG SRLY FLOW WILL TAKE HOLD...WHICH COUPLED WITH INSTABILITY/LIFT FROM THE NEARBY SYSTEM...WILL CREATE ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS SUNDAY EVENING AND INTO THE DAY MONDAY. FINALLY...THE FUN CONTINUES AS SEVERAL MORE SHORTWAVES TRAVERSE THE UPPER LEVEL TROUGH AND BRING UNSETTLED WEATHER TO THE REGION TO CONTINUE OUT THE REMAINDER OF THE EXTENDED. GIVEN THE TIMING AND PLACEMENT DISCREPANCIES OF THE LONG RANGE MODELS...CONTINUED WITH A MODEL BLEND AT THIS TIME. HOWEVER...ONE NOTE...IF THE GFS40 MODEL PANS OUT...SOME OF THESE SYSTEMS COULD PUT DOWN SOME HEAVY RAINS...WITH PWATS TOPPING OUT ABOVE 1.3 TUESDAY AFTERNOON AND EVENING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 800 AM EDT WED APR 8 2015 THE FOG PROVED TO BE FLEETING THIS MORNING AS A LAYER OF LOW TO MID CLOUDS MOVED IN AND CLEARED OUT THE LOWER VIS. LATER TODAY ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED THIS AFTERNOON. HAVE STAYED WITH A VCTS FOR THIS WITH MORE REFINEMENT POSSIBLE WITH FUTURE TAF ISSUANCES AS THE TIMING AND EFFECTS OF THIS NEXT WAVE BECOME MORE CLEAR. AFTER THIS WAVE OF ACTIVITY PASSES PATCHY FOG WILL BE A POSSIBILITY MAINLY...IN THE VALLEYS...AND HAVE ADDED SOME TO THE SME AND LOZ TAFS. WINDS WILL REMAIN MAINLY LIGHT FROM THE SOUTH...OUTSIDE OF ANY THUNDERSTORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...GREIF LONG TERM...JMW AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
422 AM EDT WED APR 8 2015 .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 400 AM EDT WED APR 8 2015 07Z SFC ANALYSIS SHOWS A STATIONARY BOUNDARY JUST NORTH OF KENTUCKY PLACING THE AREA IN A WARM AND HUMID AIR MASS. THE CONVECTION OF THE PAST DAY AND EVENING LEFT PLENTY OF GROUND MOISTURE BEHIND AND NOW THAT CLOUDS ARE CLEARING OFF TO THE EAST...EXPECT WIDESPREAD FOG TO DEVELOP AND BECOME LOCALLY DENSE THIS MORNING. ALREADY JKL...SME...AND LOZ ARE SEEING DENSE FOG. AS A RESULT...A DENSE FOG ADVISORY MAY BE NEEDED FOR MUCH OF THE AREA THROUGH DAWN. OTHERWISE...TEMPERATURES ARE IN THE MID TO UPPER 50S FOR MOST LOCATIONS WHILE DEWPOINTS ARE GENERALLY WITHIN A DEGREE OF THE DRY BULB TEMP...ALSO WINDS REMAIN LIGHT AND VARIABLE. THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL SHOW SOUTHWEST FLOW OVER KENTUCKY WITH PACKETS OF ENERGY PASSING THROUGH THE REGION EVERY FEW HOURS. SOME HEIGHT FALLS WILL GET INTO THE MIX LATE IN THE PERIOD ON THURSDAY AS A LARGER TROUGH SWEEPS EAST AND INTO THE UPPER MIDWEST. THE KEY TO THIS UNSETTLED PATTERN WILL BE THE SMALLER FEATURES THAT THE HIGHER RESOLUTION MODELS HAVE A BETTER CHANCE OF CATCHING. EVEN SO...THE CONFIDENCE IN ANY PARTICULAR SOLUTION IS LOW SO THE FORECAST HAS AN ELEMENT OF HEDGING TO IT WITH THE HRRR AND NAM12 FAVORED. THE NAM12 ACTUALLY DID A DECENT JOB DEPICTING THE CONVECTION OF THE PAST DAY SO AM INCLINED TO GIVE IT HIGHER WEIGHTING TODAY. SENSIBLE WEATHER WILL LIKELY BE A REPEAT OF TUESDAY WITH A CLUSTER OF STRONG TO SEVERE THUNDERSTORMS POSSIBLY DEVELOPING BY EARLY AFTERNOON AND TRACKING THROUGH THE NORTHERN AND CENTRAL PORTION OF THE CWA. THIS IS THE SAME PLACE THAT WAS HIT HARD YESTERDAY AND PWS WILL BE SIMILAR TODAY...SO CONSIDERED A FLASH FLOOD WATCH FOR THESE LOCATIONS. HOWEVER...THE UNCERTAINTY IS STILL TOO HIGH BARRING OBVIOUS UPSTREAM DEVELOPMENT SO WILL HIT THIS THREAT WITH AN SPS FOR NOW. THE CONVECTION SHOULD DIE DOWN LATER IN THE EVENING WITH PATCHY FOG...LOCALLY DENSE AGAIN...A CONCERN. THE SET UP REMAINS SIMILAR FOR STORMS ON THURSDAY...IF NOT A TAD BETTER AS THE MAIN TROUGH APPROACHES. ACCORDINGLY...HAVE CONTINUED THE FAIRLY HIGH CHANCES FOR SHOWERS AND STORMS INTO THURSDAY AFTERNOON AND EVENING. AGAIN USED THE SHORTBLEND COMPOSITE MODEL AS A STARTING POINT FOR THE WINDS/T/TD GRIDS THROUGH THE FIRST 18-24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS BASED ON TERRAIN FOR TONIGHT/S TEMPERATURES. AS FOR POPS...ENDED UP CLOSE TO OR A BIT HIGHER THAN A BLEND OF THE MAV AND MET VALUES THROUGH THE PERIOD. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 421 AM EDT WED APR 8 2015 AN UPPER LEVEL TROUGH...WITH SEVERAL SHORTWAVES EMBEDDED AND ROTATING WITHIN IT...WILL PUSH FROM THE UPPER MISSISSIPPI VALLEY EASTWARD FROM 0Z FRIDAY AND THROUGH THE DAY FRIDAY. OVERNIGHT FRIDAY AND INTO THE DAY SATURDAY...THIS WAVE WILL WEAKEN AND CONTINUE TO SHIFT EASTWARD...WHILE BUILDING HEIGHTS AND DEAMPLIFIED RIDGING TAKES HOLD ACROSS THE OHIO RIVER VALLEY. LONG RANGE MODELS ARE IN AGREEMENT OF THIS FLOW BECOMING ZONAL THROUGH SUNDAY...WITH A SHORTWAVE DEVELOPING AND RIDING EASTWARD ACROSS KY LATE IN THE DAY AND CONTINUING INTO MONDAY. UNFORTUNATELY FOR THE REST OF THE EXTENDED...THE FEATURES ARE WELL AGREED UPON...BUT THE TIMING AND PLACEMENT IS NOT. SUNDAY NIGHT/MONDAY MORNING A UPPER LEVEL CLOSED LOW WILL LIKELY DEVELOP OVER THE TX/NM AREA...CAUSING AMPLIFICATION AND EVENTUALLY FALLING HEIGHTS ACROSS KY AS THE LOW STARTS TO MOVE NEWARD DURING THE DAY MONDAY...LOSING CONSIDERABLE STRENGTH AS IT REACHES THE UPPER MISSISSIPPI VALLEY BY TUESDAY. MULTIPLE WEAKER SHORTWAVES WILL MOVE AROUND THESE CLOSED LOWS...TRAVELING DIRECTLY INTO THE OHIO RIVER VALLEY. AT THE SURFACE...A LOW PRESSURE SYSTEM WILL BE COLLOCATED WITH THE UPPER LEVEL TROUGH ON FRIDAY AND FOLLOW THE TRACK NORTHEASTWARD ACROSS THE GREAT LAKES. THIS WILL SEND A COLD FRONT EASTWARD AND INTO THE STATE OF KY...STARTING OFF IN THE FAR WEST AROUND 0Z TO 3Z...AND REACHING THE JKL CWA BY LATE MORNING FRIDAY BEFORE QUICKLY SHIFTING EASTWARD IN THE AFTERNOON...JUST AS THE UPPER LEVEL TROUGH EXITS. BEST INSTABILITY AND MOISTURE WILL BE LOCATED ALONG AND JUST AHEAD OF THE FRONT...WITH SHOWERS AND THUNDERSTORMS CHANCES EXPECTED TO INCREASE THROUGH FRIDAY MORNING...BEFORE QUICKLY TAPERING OFF ONCE THE FRONT PASSES THROUGH AND A STRONG SHOT OF DRIER AND COOLER NRLY FLOW MOVES IN. AS HEIGHTS BUILD SATURDAY INTO SATURDAY NIGHT...EXPECT SURFACE HIGH PRESSURE TO BE IN CHARGE...WITH LIGHT WINDS AND GENERALLY CLEAR SKIES. THE COULD CREATE SOME RIDGE VALLEY SPLIT CONDITIONS FOR OVERNIGHT LOWS...AS WAS REFLECTED IN THE FORECAST. BY SUNDAY...THE NEXT SHORTWAVE WILL BEGIN ENCROACHING UPON THE REGION...WITH YET ANOTHER SURFACE LOW LOCATED JUST TO OUR SW. STRONG SRLY FLOW WILL TAKE HOLD...WHICH COUPLED WITH INSTABILITY/LIFT FROM THE NEARBY SYSTEM...WILL CREATE ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS SUNDAY EVENING AND INTO THE DAY MONDAY. FINALLY...THE FUN CONTINUES AS SEVERAL MORE SHORTWAVES TRAVERSE THE UPPER LEVEL TROUGH AND BRING UNSETTLED WEATHER TO THE REGION TO CONTINUE OUT THE REMAINDER OF THE EXTENDED. GIVEN THE TIMING AND PLACEMENT DISCREPANCIES OF THE LONG RANGE MODELS...CONTINUED WITH A MODEL BLEND AT THIS TIME. HOWEVER...ONE NOTE...IF THE GFS40 MODEL PANS OUT...SOME OF THESE SYSTEMS COULD PUT DOWN SOME HEAVY RAINS...WITH PWATS TOPPING OUT ABOVE 1.3 TUESDAY AFTERNOON AND EVENING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 230 AM EDT WED APR 8 2015 NOW THAT THE CONVECTION HAS MOVED ON EAST...EXPECT SOME FOG AND LOW CEILINGS TO DEVELOP LATER TONIGHT AND BUILD TOWARDS DAWN WITH A TIME OF LIFR POSSIBLE. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED THIS AFTERNOON. HAVE INCLUDED A VCTS FOR THIS WITH MORE REFINEMENT POSSIBLE WITH FUTURE TAF ISSUANCES AS THE TIMING AND EFFECTS OF THIS NEXT WAVE BECOME MORE CLEAR. WINDS WILL REMAIN MAINLY LIGHT FROM THE SOUTH OUTSIDE OF THUNDERSTORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR KYZ044- 050>052-058>060-068-069-079-080-083>088-104-106>120. && $$ SHORT TERM...GREIF LONG TERM...JMW AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
400 AM EDT WED APR 8 2015 .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 400 AM EDT WED APR 8 2015 07Z SFC ANALYSIS SHOWS A STATIONARY BOUNDARY JUST NORTH OF KENTUCKY PLACING THE AREA IN A WARM AND HUMID AIR MASS. THE CONVECTION OF THE PAST DAY AND EVENING LEFT PLENTY OF GROUND MOISTURE BEHIND AND NOW THAT CLOUDS ARE CLEARING OFF TO THE EAST...EXPECT WIDESPREAD FOG TO DEVELOP AND BECOME LOCALLY DENSE THIS MORNING. ALREADY JKL...SME...AND LOZ ARE SEEING DENSE FOG. AS A RESULT...A DENSE FOG ADVISORY MAY BE NEEDED FOR MUCH OF THE AREA THROUGH DAWN. OTHERWISE...TEMPERATURES ARE IN THE MID TO UPPER 50S FOR MOST LOCATIONS WHILE DEWPOINTS ARE GENERALLY WITHIN A DEGREE OF THE DRY BULB TEMP...ALSO WINDS REMAIN LIGHT AND VARIABLE. THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL SHOW SOUTHWEST FLOW OVER KENTUCKY WITH PACKETS OF ENERGY PASSING THROUGH THE REGION EVERY FEW HOURS. SOME HEIGHT FALLS WILL GET INTO THE MIX LATE IN THE PERIOD ON THURSDAY AS A LARGER TROUGH SWEEPS EAST AND INTO THE UPPER MIDWEST. THE KEY TO THIS UNSETTLED PATTERN WILL BE THE SMALLER FEATURES THAT THE HIGHER RESOLUTION MODELS HAVE A BETTER CHANCE OF CATCHING. EVEN SO...THE CONFIDENCE IN ANY PARTICULAR SOLUTION IS LOW SO THE FORECAST HAS AN ELEMENT OF HEDGING TO IT WITH THE HRRR AND NAM12 FAVORED. THE NAM12 ACTUALLY DID A DECENT JOB DEPICTING THE CONVECTION OF THE PAST DAY SO AM INCLINED TO GIVE IT HIGHER WEIGHTING TODAY. SENSIBLE WEATHER WILL LIKELY BE A REPEAT OF TUESDAY WITH A CLUSTER OF STRONG TO SEVERE THUNDERSTORMS POSSIBLY DEVELOPING BY EARLY AFTERNOON AND TRACKING THROUGH THE NORTHERN AND CENTRAL PORTION OF THE CWA. THIS IS THE SAME PLACE THAT WAS HIT HARD YESTERDAY AND PWS WILL BE SIMILAR TODAY...SO CONSIDERED A FLASH FLOOD WATCH FOR THESE LOCATIONS. HOWEVER...THE UNCERTAINTY IS STILL TOO HIGH BARRING OBVIOUS UPSTREAM DEVELOPMENT SO WILL HIT THIS THREAT WITH AN SPS FOR NOW. THE CONVECTION SHOULD DIE DOWN LATER IN THE EVENING WITH PATCHY FOG...LOCALLY DENSE AGAIN...A CONCERN. THE SET UP REMAINS SIMILAR FOR STORMS ON THURSDAY...IF NOT A TAD BETTER AS THE MAIN TROUGH APPROACHES. ACCORDINGLY...HAVE CONTINUED THE FAIRLY HIGH CHANCES FOR SHOWERS AND STORMS INTO THURSDAY AFTERNOON AND EVENING. AGAIN USED THE SHORTBLEND COMPOSITE MODEL AS A STARTING POINT FOR THE WINDS/T/TD GRIDS THROUGH THE FIRST 18-24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS BASED ON TERRAIN FOR TONIGHT/S TEMPERATURES. AS FOR POPS...ENDED UP CLOSE TO OR A BIT HIGHER THAN A BLEND OF THE MAV AND MET VALUES THROUGH THE PERIOD. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 400 AM EDT WED APR 8 2015 WILL BE ISSUED SHORTLY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 230 AM EDT WED APR 8 2015 NOW THAT THE CONVECTION HAS MOVED ON EAST...EXPECT SOME FOG AND LOW CEILINGS TO DEVELOP LATER TONIGHT AND BUILD TOWARDS DAWN WITH A TIME OF LIFR POSSIBLE. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED THIS AFTERNOON. HAVE INCLUDED A VCTS FOR THIS WITH MORE REFINEMENT POSSIBLE WITH FUTURE TAF ISSUANCES AS THE TIMING AND EFFECTS OF THIS NEXT WAVE BECOME MORE CLEAR. WINDS WILL REMAIN MAINLY LIGHT FROM THE SOUTH OUTSIDE OF THUNDERSTORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GREIF LONG TERM...JMW AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
939 PM CDT THU APR 9 2015 .UPDATE... A BKN BAND OF STRONG TO SVR STORMS CONTINUES TO MARCH EAST ACRS NRN LA THIS EVENING AHEAD OF A COLD FRONT. A SECOND BAND OF TSTMS HAS FORMED ALONG THE FRONT...EXTENDING FM HOT SPRINGS ARK TO TERRELL TX. THE FRONT IS STILL ON TRACK TO REACH OUR NWRN ZONES LATE TONIGHT BETWEEN MIDNIGHT AND 3 AM. THE BAND OF SHOWERS AND TSTMS WILL GRADUALLY SHIFT SOUTH INTO THE AREA OVERNIGHT...WITH ACTIVITY BECOMING MORE WIDESPREAD DURING THE DAY FRIDAY AS THE FRONT MOVES THROUGH THE AREA. ONLY MINOR CHANGES TO GRIDS TONIGHT...MAINLY TO BRING IN LINE WITH RECENT OBS AND TRENDS. ADJUSTED THE POP/WX GRIDS FOR THE EVENING. INCORPORATED A BLEND OF RECENT HRRR RUNS...WHICH GENERALLY LOWERED POPS FOR THE EVENING. ACTIVITY HAS STAYED NORTH OF THE CWA SO FAR...BUT EXPECT IT WILL BEGIN TO AFFECT THE NRN TIER OF PARISHES AND COUNTIES TOWARD MIDNIGHT WITH CHCS INCREASING THEREAFTER. OTHERWISE...FCST SEEMS TO BE IN GOOD SHAPE. 24 && .PREV DISCUSSION... /ISSUED 635 PM CDT THU APR 9 2015/ DISCUSSION... FOR THE 10/00Z TAF ISSUANCE. AVIATION... A COLD FRONT WILL SLOWLY ADVANCE INTO THE FORECAST AREA LATER TONIGHT AND FRIDAY MORNING BEFORE STALLING FRIDAY MORNING...LIKELY NORTH OF THE I-10 CORRIDOR. AHEAD OF THE FRONT...SOUTHERLY FLOW WILL CONTINUE WITH LOW CLOUDS AGAIN DEVELOPING DURING THE EVENING HOURS...WITH CONDITIONS FROM MVFR TO IFR. SHOWERS AND THUNDERSTORMS WILL BEGIN TO DEVELOP AROUND 10/09Z NEAR KAEX WITH THE FRONT...THEN AFTER 10/12Z FOR THE TAF SITES FURTHER SOUTH. RUA PREV DISCUSSION... /ISSUED 336 PM CDT THU APR 9 2015/ DISCUSSION...SURFACE ANALYSIS INDICATING APPROACHING NE-SW ORIENTED COLD FRONT STRETCHING ACROSS WESTERN OKLAHOMA AND THROUGH CENTRAL TEXAS. RADAR MOSAIC SHOWING A FEW SHOWERS NOW DEVELOPING ALONG BOUNDARY...WITH MORE ROBUST CONVECTION DEVELOPING PRE- FRONTAL FROM SOUTHWEST ARKANSAS INTO CENTRAL TEXAS NEAR AUSTIN. OTHER THAN THAT...LOCAL AREA REMAINS CLEAR OF ANY PRECIP. CLOUDS WERE ABUNDANT TODAY BUT NONE-THE-LESS...TEMPERATURES HAVE WARMED AGAIN INTO THE LOW TO MID 80S...SEVERAL DEGREES ABOVE THE NORM. WET WEATHER PATTERN INCOMING. AFOREMENTIONED FRONTAL BOUNDARY PROGGED TO ADVANCE RAPIDLY SOUTHEAST TO ALONG A LINE FROM NEAR AEX TO BPT TOWARD SUNRISE...THEN SLOWING AND STALLING MOVING INTO THE NEAR COASTAL WATERS. FRONT THEN EXPECTED TO RETREAT RAPIDLY NORTH SUNDAY AS A WARM FRONT. LOW LEVEL CONVERGENCE WITH FRONT...ISENTROPIC ASCENT NORTH OF FRONT ALONG WITH A SERIES OF DISTURBANCES MOVING THROUGH ON A STRONG WEST TO SOUTHWEST ALOFT....WARRANTS HIGH END RAIN CHANCES BEGINNING FRIDAY AND THROUGH THE WEEKEND. SPC HAS PLACED THE FORECAST AREA WITHIN A MARGINAL TO SLIGHT RISK OF SEVERE WEATHER FOR FRIDAY. GOING INTO THE NEW WORK-WEEK...DEEP GULF/PACIFIC MOISTURE REMAINS IN PLACE THROUGH AT LEAST THURSDAY PER THE ECMWF AND GFS. THUS RESPECTABLE POPS CONTINUING. MARINE...LIGHT SOUTHERLIES WILL CONTINUE TONIGHT...BECOMING MORE EASTERLY FRIDAY AS A COLD FRONT ADVANCES INTO THE NEAR COASTAL WATERS AND STALLS. WITH THIS FRONT WILL COME A CHANCE FOR A FEW SHOWERS AND THUNDERSTORMS...WITH THIS ACTIVITY CONTINUING INTO SATURDAY. THE BOUNDARY WILL THEN LIFT NORTH AS WARM FRONT SUNDAY WITH A SOUTHERLY FLOW RETURNING. UPPER LEVEL DISTURBANCES MOVING ACROSS THE AREA WILL THEN KEEP A DAILY CHANCE FOR SHOWERS AND THUNDERSTORMS CONTINUING THROUGH MID-WEEK. 23 && .PRELIMINARY POINT TEMPS/POPS... AEX 69 77 61 77 / 40 70 30 50 LCH 71 80 65 78 / 20 70 40 60 LFT 71 82 65 78 / 10 70 40 60 BPT 71 80 66 78 / 20 70 40 60 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
718 PM EDT THU APR 9 2015 .SYNOPSIS... A WARM FRONT WILL SLOWLY LIFT NORTHWARD THROUGH VIRGINIA TONIGHT INTO FRIDAY MORNING. A STRONG COLD FRONT CROSSES THE AREA LATE FRIDAY...WITH HIGH PRESSURE BUILDING BACK INTO THE REGION OVER THE WEEKEND. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... LATEST SFC ANALYSIS REVEALS HIGH PRESSURE RIDGING DOWN THE MID ATLANTIC COAST WITH A STALLED FRONTAL BNDRY OVER INTERIOR NC. A STRONG SFC LOW IS CENTERED OVER THE MIDWEST STATES...WHILE A POTENT MID-LEVEL SHORTWAVE TROF IS OVER THE CENTRAL PLAINS. ONGOING CONVECTION REMAINS TO THE SOUTH OF THE STALLED BOUNDARY (WARM FRONT) EARLY THIS EVENING AND THUS WILL CARRY ONLY LIMITED POPS AREAWIDE THRU 10 PM OR SO. LATEST HRRR HINTS THAT CONVECTION OVER CENTRAL NC WILL MOVE NE INTO OUR FA LATE THIS EVENING AND OVERNIGHT AS THE WARM FRONT STARTS TO LIFT BACK NORTH...AND HAVE ADJUSTED POPS ACCORDINGLY TO SHOW HIGH CHC/LIKELY POPS THRU THE CENTER OF OUR FA. LOWEST POPS (~20%) WILL BE ACROSS SOUTHSIDE HAMPTON ROADS AND COASTAL NE NC. WILL CARRY SLIGHT CHC TSTMS AS WELL WITH LIMITED INSTABILITY. TEMPS WILL TEND TO HOLD STEADY THIS EVENING AND OVERNIGHT BEFORE RISING PRIOR TO SUNRISE FROM NORTH TO SOUTH WITH THE WARM FROPA. LOWS IN THE LOW 40S EASTERN SHORE TO NR 60 FAR SOUTH. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... THE AFOREMENTIONED MID-LEVEL TROUGH AND ATTENDANT SURFACE LOW OVER THE GREAT LAKES WILL LIFT INTO ONTARIO ON FRIDAY...SHUNTING A SFC COLD FRONT IN OUR DIRECTION LATE FRIDAY INTO FRIDAY NIGHT. THE LOCAL AREA REMAINS IN A MOIST AIRMASS W/SURFACE DEWPOINTS IN THE 60S...PRECIPITABLE WATER VALUES ~+2SD...INCREASING LLVL STEERING FLOW AND MUCAPE IN THE 1000-1500 J/KG RANGE. THIS WILL LIKELY BE SUFFICIENT FOR CONVECTIVE DEVELOPMENT FRIDAY AFTERNOON AND EVENING ACROSS THE REGION. SPC CONTINUES TO OUTLOOK THE REGION IN A SLIGHT RISK OF SEVERE STORMS WITH LARGE HAIL/DMGG WINDS THE PRIMARY HAZARDS. THE TIMING OF THE SEVERE THREAT LOOKS TO BE LATE AFTERNOON THROUGH EVENING AS THE FRONT PUSHES ACROSS THE AREA. MAIN CHANGE TO PREVIOUS FORECAST WAS TO INCREASE POPS TO 70% AND DELAY TIMING OF PRECIP A COUPLE HRS AS MOST GUIDANCE HAS SLOWED DOWN THE SYSTM JUST A BIT...MAKING MUCH OF THE DAY THRU 18Z DRY FOR ALL OF THE FA EXCEPT FAR WRN AREAS. QUITE WARM AS WELL...WITH HIGHS IN THE LO TO MID 80S ALONG THE COASTAL PLAIN...UPR 70S TO LWR 80S OTHER AREAS. THE COLD FRONT SLIDES OFFSHORE BY SAT MORNG. HIGH PRESSURE BUILDING IN BEHIND THE FRONT WILL BRING A PLEASANT WEEKEND TO THE FA WITH HIGHS BOTH DAYS IN THE UPR 60S TO LWR 70S UNDER A MSTLY SUNNY SKY. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE LONG TERM PERIOD BEGINS WITH HIGH PRESSURE OVER THE REGION WITH DRY CONDITIONS AND SEASONABLE TEMPERATURES THROUGH MONDAY. THE MODELS AND IN GOOD AGREEMENT ON THE THE SURFACE HIGH SLOWLY SLIDING OFF THE COAST ON MONDAY WITH THE APPROACH OF A WEAK COLD FRONT MONDAY NIGHT INTO TUESDAY MORNING. THE 12 ECMWF HAS MORE MOISTURE WITH THAN THE PREVIOUS RUN AND LOOKS MORE LIKE THE GFS. THE 12Z GFS IS A TOUCH SLOWER WITH THE FRONT..BUT STILL SHOWS GOOD LIFT AND MOISTURE SO HAVE KEPT THE CHANCE POPS FOR LATE MONDAY NIGHT INTO THE DAY ON TUESDAY. STILL WOULD EXPECT QPF TO BE ON THE LOW SIDE AS THE BULK OF THE MOISTURE IS STILL OVER THE GULF COAST STATES IN ADVANCE OF THE NEXT SYSTEM. BY TUESDAY EVENING...SHOULD SEE THE FRONT PUSH INTO SC/GA WITH HIGH PRESSURE SAGGING DOWN THE EASTERN SEABOARD. THE GFS AND ECMWF SHOW A LOT LESS MOISTURE FOR WEDNESDAY INTO THURSDAY THAN PREVIOUS RUNS...SO HAVE STARTED TO LOWER POPS DOWN TO SLIGHT CHANCE LEVELS NOW FOR MOST OF THE AREA...BUT WOULD NOT BE SURPRISED TO SEE A DRY DAY ON WEDNESDAY. THE UNCERTAINTY COMES ON THURSDAY AS THE FLOW ALOFT BECOMES MORE SOUTHWEST AND WITH A DEVELOPING TROUGH OVER THE SOUTHERN PLAINS...SHOULD SEE GULF MOISTURE BEGINNING TO ADVECT BACK INTO THE REGION. HAVE MAINTAINED THE CHANCE POPS FOR NOW AS TIMING MAY BE A QUESTION...BUT EXPECT TO SEE A DECENT RAINFALL EVENT LATE NEXT WEEK AS WAVES OF ENERGY LIFT NE AROUND THE DEVELOPING TROUGH. FOR TEMPERATURES...HAVE GENERALLY RUN CLOSE TO THE SUPERBLEND GUIDANCE WITH HIGHS GENERALLY IN THE 70S MOST OF THE WEEK...ALTHOUGH DID LOWER VALUES A TOUCH ON WEDNESDAY BEHIND THE FRONT...SO WOULD NOT BE SURPRISED TO SEE HIGH MORE IN THE MID TO UPPER 60S ON WEDNESDAY AND POSSIBLY THURSDAY IF WEDGING SETS UP WITH OVERRUNING CLOUDS. && .AVIATION /23Z THURSDAY THROUGH TUESDAY/... CONTD E/ENE FLOW HAS KEPT ALL TERMINALS LOW END MVFR/IFR...WITH CEILINGS BEGINNING TO LOWER AT KPHF/KORF/KECG WHERE CEILINGS WENT TO OR ABV 1KFT THIS AFTERNOON. CONDITIONS SHOULD CONTINUE TO DETERIORATE AND BECOME LIFR OVER THE NEXT 2-4 HOURS AS STATIONARY FRONT SOUTH OF THE REGION BEGNS LIFTING NWD TOWARD THE VA/NC BORDER. THIS HANDLED VERY WELL BY 18Z TAFS...AND HAVE MADE ONLY SOME MINOR ADJUSTMENTS TO TIMING/CEILING HEIGHTS. ONCE LO LVL FLOW TURNS SLY/SSWLY...EXPECT CONDITIONS TO BEGIN IMPROVING. IMING LOOKS TO BE AFTER 08Z AT KECG...AND AFTER 10Z AT KORF/KPHF...WITH KRIC/KSBY LIKELY TO BE THE LAST TO IMPROVE TO MVFR/VFR...13Z TO 15Z. AS FAR AS PRECIP NEXT 6-12 HOURS...CLUSTERS OF SHWRS/TSTMS OVER NC CONT LIFTING NEWD TOWARD THE REGION...BUT WEAKEN UPON ENCOUNTERING STABLE NEAR SURFACE AIRMASS NORTH OF STATIONARY FRONT. HRRR/RUC SUGGESTING THIS PRECIP MAY WELL WEAKEN SIGNIFICANTLY OR DISSIPATE BEFORE AFFECTING TERMINALS. SO HAVE KEPT SHWR/TSTM ACTVTY OUT OF TAFS OVERNIGHT. WILL MONITOR CLOSELY. SHOULD SHWR/TSTM ACTVTY MOVE INTO ANY TERMINALS...WOULD EXPECT CEILINGS TO BRIEFLY BECOME MVFR. S/SW WINDS DEVELOPING FRIDAY MORNING WILL SCOUR OUT THE LOW LEVEL MOISTURE...AND BECOME GUSTY (AROUND 25 KTS) AT TIMES AFT 13Z. SCT TSTMS...SOME STRONG...MAY IMPACT THE TAF SITES LATE FRIDAY AFTN/EVENING. VFR AND DRY WEATHER WILL PREVAIL SATURDAY THROUGH MONDAY WITH HIGH PRESSURE BUILDING INTO THE REGION. THERE WILL BE A CHANCE FOR SHOWERS ON TUESDAY. && .MARINE... STILL SEEING THE INFLUENCE OF THE HIGH PRESSURE SYSTEM OVER THE NERN US NOSING DOWN INTO THE COASTAL WATERS THIS AFTERNOON. WIND ARE GENERALLY 10 TO 15 KT OUT OF THE E TO NE. THIS IS SERVING TO KEEPING THE COAST WATERS STILL IN THE 5 TO 7 FT RANGE FOR THE NORTHERN 2 COASTAL ZONES...SO HAVE KEPT SCA ON GOING. THIS HIGH WILL PULL OUT OF THE AREA TONIGHT AND THE FLOW WILL TURN SOUTHERLY IN ADVANCE OF A COLD FRONT WHICH MOVES THROUGH ON FRIDAY. IN ADVANCE OF THE FRONT WILL SEE WINDS KICK UP TO AROUND 15 TO 20 KT. THE WINDS ALOFT WILL BE STRONGER...BUT THE COOLER WATER WILL SERVE TO KEEP THE HIGHER WINDS OFF THE WATER SURFACE. SOME THUNDERSTORMS ARE EXPECTED WITH THIS FRONT AND THESE STORMS COULD BRIEFLY BRING THE STRONGER WINDS DOWN TO THE SURFACE. ONCE THE WINDS TURN NW BEHIND THE FRONT SHOULD SLOWLY SEE THE WINDS DIMINISH LATER FRIDAY NIGHT BACK TO 10 TO 15 KT. SO FOR NOW HAVE EXTEND THE SCA THROUGH 1 AM FRIDAY FOR SEAS OF 5 TO 7 FT. HIGH PRESSURE BUILDS INTO THE REGION ON SATURDAY AND LINGERS THROUGH MONDAY. THIS SHOULD BRING A PERIOD OF QUIET WEATHER WITH THE WINDS DIMINISHING ON SUNDAY TO UNDER 10 KT. THE NEXT FRONT TO IMPACT THE WATERS ARRIVES ON MONDAY NIGHT AS A COLD FRONT SWINGS ACROSS THE AREA. EXPECT AN INCREASE IN SW WINDS ON MONDAY AHEAD OF THE FRONT...BUT SHOULD REMAIN BELOW SCA LEVELS AGAIN IN THE 15 TO 20 KT RANGE. HIGH PRESSURE RETURNS FOR THE WEDNESDAY AND THURSDAY TIME PERIOD WITH ANOTHER PERIOD OF QUIET WEATHER. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EDT SATURDAY FOR ANZ650-652. && $$ SYNOPSIS...JDM NEAR TERM...JDM/MAS SHORT TERM...MAS/MAM LONG TERM...ESS AVIATION...LSA/WRS MARINE...ESS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
251 PM EDT WED APR 8 2015 .SYNOPSIS... A COLD FRONT WILL CONTINUE TO DROP SOUTH AND WEST THROUGH OUR AREA THIS MORNING. THE BOUNDARY WILL STALL OUT OVER THE POTOMAC HIGHLANDS INTO SOUTHERN VIRGINIA THIS AFTERNOON THROUGH THURSDAY BEFORE RETURNING AS A WARM FRONT LATE THURSDAY NIGHT AND FRIDAY. A COLD FRONT WILL PASS THROUGH THE REGION FRIDAY NIGHT AND HIGH PRESSURE WILL RETURN FOR THE WEEKEND. && .NEAR TERM /THROUGH THURSDAY/... A WEDGE OF HIGH PRESSURE WILL PERSIST ACROSS MOST OF THE MID- ATLANTIC. THE FORWARD EXTENT OF THIS AIRMASS IS ACROSS CENTRAL VIRGINIA. AN ADVANCING MCS WILL APPROACH CENTRAL VIRGINIA THIS AFTERNOON. A COLD FRONT SEPERATES COOL HIGH PRESSURE WITH A WARM UNSTABLE AIRMASS. ON THE WARM SIDE...TEMPS HAVE RISEN TO NEAR 65 WITH DEWPTS IN THE MID-UPPER 50S. A MCS WILL APPROACH EASTERN WEST VIRGINIA AND CENTRAL VIRGINIA THIS AFTERNOON. STRONG AND SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS THE VIRGINIA AND SOUTHERN POTOMAC HIGHLANDS AND CENTRAL SHENANDOAH VALLEY AS INSTABILITY HAS RISEN TO ABOVE 1000 J/KG WITH 30KTS OF BULK 0-6 KM SHEAR. THIS SYSTEM HAS A HISTORY OF DAMAGING WINDS...LARGE HAIL AND FREQUENT LIGHTNING. THERE HAS BEEN A SLIGHT DOWNWARD TREND IN ACTIVITY AS IT APPROACHES VA BUT SOME POCKETS OF STRONG WINDS EXIST IN THE LEADING EDGE OF THE CONVECTIVE LINE AND THEREFORE STORMS MAY PRODUCE HAZARDOUS CONDITIONS. HRRR HAS BEEN CONSISTENT TODAY WITH LINE REACHING THE MTNS. FURTHER NORTH AND EAST AND IN THE HIGH PRESSURE WEDGE...ANY CONVECTIVE ACTIVITY WILL QUICKLY DISSAPATE AS IT MOVES INTO A VERY STABLE ATMOSPHERE. RAIN WILL TAKE OVER AND MOVE EASTWARD THIS EVENING. SUBSIDENCE BEHIND THE MCS WILL LEAD TO A LULL OF WIDESPREAD RAIN BUT LOW LEVEL SATURATION WILL MAINTAIN CHANCES OF DZ OR RAIN THROUGH THE EVENING. NOTHING WILL PUSH THE WEDGE FROM PERSISTING ACROSS THE MID- ATLANTIC THROUGH THURSDAY. THE COLD FRONT MAY RETREAT FURTHER NORTH BUT TEMPS WILL STILL REMAIN BELOW CLIMO. SLIGHT RIDGING ALOFT WILL ALLOW DISTURBANCES TO MOVE TO THE NORTHWEST OF THE REGION. LITTLE FORCING WILL LIMIT WIDESPREAD RAIN THURSDAY BUT LOW LEVEL SATURATION WILL ALLOW FOR DRIZZLE AT TIMES. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... A WARM FRONT WILL LIFT NORTH ACROSS THE REGION THURSDAY NIGHT. A STRONG INVERSION WITH ADEQUATE SATURATION IS EXPECTED IN THE BOUNDARY LAYER BUT SHOULD GRADUALLY WEAKEN THROUGHOUT THE NIGHT INTO EARLY FRIDAY MORNING. EXPECT RAIN SHOWERS OR AREAS OF DRIZZLE ACROSS PARTS OF THE REGION. LOW TEMPERATURES SHOULD BOTTOM OUT IN THE LOWER 40S IN NORTHEAST MARYLAND TO THE MIDDLE 50S IN THE CENTRAL SHENANDOAH VALLEY. SHOULD ANY EASTERLY COMPONENT TO THE WIND VEER AROUND TO MORE SOUTHERLY...THEN LOW TEMPERATURES WILL BECOME HIGHER THURSDAY NIGHT. THE LATEST MODEL RUNS OF THE NAM AND GFS HAVE GOOD AGREEMENT IN THURSDAY`S LOW TEMPERATURES. ON FRIDAY...LOW PRESSURE WILL MOVE NORTHEAST ACROSS THE GREAT LAKES. A COUPLE OF RAIN SHOWERS AND PATCHY DRIZZLE EARLY FRIDAY WILL LINGER BUT BECOME MORE SPARSE AS MILDER AIR BECOMES MORE DOMINANT BOTH ALOFT AND AT THE SURFACE. WITH A WARM FRONT NOW TO THE NORTH OF THE REGION AND A PERSISTENT...YET INCREASING...SOUTHERLY FLOW EVOLVING...TEMPERATURES SHOULD QUICKLY SORE UPWARDS FROM THE 40S AND 50S TO THE 70S AND A FEW 80S BY MID-AFTERNOON FRIDAY. ANY BREAKS IN CLOUD COVER WILL LEAD TO GREATER INSTABILITY DURING THE MORNING AND AFTERNOON HOURS. WE ARE EXPECTING A COLD FRONT...ATTACHED TO THE GREAT LAKES` LOW PRESSURE...TO PUSH ACROSS THE REGION FROM WEST TO EAST. THERE IS STILL UNCERTAINTY IN THE TIMING OF THE COLD FRONTAL PASSAGE. AS OF NOW...TIMING APPEARS TO BE AROUND NOON IN THE POTOMAC HIGHLANDS...LATE AFTERNOON ALONG I- 95 AND MID-EVENING LOWER SOUTHERN MARYLAND. SHOWERS SHOULD BE HEAVY AND THUNDERSTORMS STRONG TO SEVERE. MUCH OF ANY SEVERE THUNDERSTORMS WOULD BE MORE EXPECTED FROM THE BLUE RIDGE MOUNTAINS TO THE CHESAPEAKE BAY AND SOUTHERN MARYLAND. THERE IS CURRENTLY A SLIGHT RISK FOR AN AREA FROM ALONG I-95 TO THE SOUTH AND EAST FOR FRIDAY INTO FRIDAY EVENING. THE MAIN THREAT WOULD BE DAMAGING WIND GUSTS AND LARGE HAIL. HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE MIDWEST BEGINNING FRIDAY NIGHT. TEMPERATURES AND DEWPOINT TEMPERATURES WILL DROP AS COOLER AND DRIER AIR WORKS INTO THE REGION. OUR CURRENT FORECAST HAS LOW TEMPERATURES FRIDAY NIGHT IN THE UPPER 40S TO NEAR 50. HOWEVER...IF ENOUGH COOLER AIR ALOFT MOVES IN QUICKER THAN EXPECTED...THEN LOW TEMPERATURES MAY BE ANOTHER 5 DEGREES COOLER. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... SURFACE HIGH OVER THE REGION SATURDAY WILL MOVE OFFSHORE BY SUNDAY AFTERNOON. DRY MILD CONDITIONS ARE EXPECTED INTO THE EARLY HALF OF THE UPCOMING WEEK. RAINFALL ASSOCIATED WITH A SURFACE LOW OVER THE SOUTHERN PLAINS WILL AFFECT THE MID ATLANTIC REGION BY LATE MONDAY OR EARLY TUESDAY AND CONTINUE THROUGH MIDWEEK. A WARM FRONT WILL CROSS THE REGION DURING THE DAY TUESDAY BRINGING WARMER THAN NORMAL TEMPERATURES TO THE AREA. THE LOW WILL CROSS THE REGION AND MOVE OFFSHORE WEDNESDAY. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... MVFR/IFR CONDITIONS WILL PERSIST THIS AFTERNOON AS A WEDGE OF HIGH PRESSURE WEDGES INTO THE MID-ATLANTIC. CIGS WILL LOWER TONIGHT AND IFR WITH SUB-IFR CONDITIONS EXPECTED INTO THURSDAY MORNING. - RADZ IS POSSIBLE TONIGHT. MVFR VSBYS ARE EXPECTED THIS AFTERNOON THROUGH THURSDAY MORNING. CIGS SHOULD BECOME MVFR BY MID-MORNING THURSDAY AND PERSIST THROUGH THU AFTERNOON. A COLD FRONT WILL SLOWLY RETREAT TO THE NORTH THURSDAY NIGHT INTO FRIDAY MORNING. IFR CONDITIONS EXPECTED THURSDAY NIGHT BEFORE REACHING VFR FRIDAY MID-MORNING. PERIODS OF MVFR/IFR CONDITIONS POSSIBLE WITH SHOWERS AND NUMEROUS THUNDERSTORMS. SOME THUNDERSTORMS MAY PRODUCE GUSTY WINDS AND LARGE HAIL. && .MARINE... A RIDGE AXIS WILL PERSIST OVER THE WATERS THROUGH THURSDAY. THE GRADIENT HAS LED TO GUSTS 15-20KTS AT TIMES. SCA IS IN EFFECT THIS AFTERNOON. MIXING SHOULD BE REDUCED THIS EVENING. THE GRADIENT SHOULD RELAX THURSDAY AND SCA ARE NOT EXPECTED. NO MARINE HAZARDS EXPECTED THURSDAY NIGHT. SMALL CRAFT ADVISORY CONDITIONS POSSIBLE FRIDAY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ530>543. && $$ SYNOPSIS...HAS NEAR TERM...HAS SHORT TERM...KLW LONG TERM...CEM AVIATION...HAS/KLW MARINE...HAS/KLW
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
219 PM EDT WED APR 8 2015 .SYNOPSIS... A BACKDOOR COLD FRONT WILL DROP SOUTH ACROSS THE LOCAL AREA EARLY TODAY THROUGH TONIGHT. THE FRONT THEN WEAKENS AND LIFTS BACK NORTH AS A WARM FRONT ON THURSDAY. ANOTHER COLD FRONT CROSSES THE REGION LATE FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... FORECAST UPDATED TO LWR POPS FOR THE REMAINDER OF THE DAY AND MAKE CHANGES TO HRLY TEMPS WHICH ARE QUITE TRICKY DUE TO A SLOWLY SAGGING COLD FRNT THRU THE AREA. PREVIOUS DISCUSSION... LATEST SURFACE ANALYSIS FEATURES SFC LOW PRESSURE IN PLACE OVER THE CENTRAL HIGH PLAINS, WITH A QUASI- STATIONARY FRONTAL BOUNDARY DRAPED ACROSS THE MID MS VLY OVER INTO THE OHIO VLY AND THE LWR EASTERN SHORE. NOTING SOME POCKETS OF SHRAS ACROSS THE AREA ON REGIONAL RADAR MOSAIC IN ASSOCIATION WITH A FEW WEAK DISTURBANCES. A FEW SCT SHRAS ARE CURRENTLY PUSHING EAST ON THE SOUTHERN PERIPHERY OF THE FRONTAL ZONE ACROSS THE LWR EASTERN SHORE THIS MORNING. MEANWHILE TO THE WEST, A MORE SUBSTANTIAL AREA OF SHRAS IN ASSOCIATION WITH DECAYING CONVECTIVE COMPLEX THAT ROLLED ACROSS THE OHIO RVR VALLEY LAST NIGHT IS CURRENTLY PUSHING FROM E WV/WESTERN VA OVER TO THE PIEDMONT IN THE FORM OF SOME LIGHT TO MODERATE RAIN SHRAS. LATEST HRRR AND TO A LESSER EXTENT THE 00Z NAM HAVE BEST HANDLED THIS FEATURE THUS FAR... AND HAVE THEREFORE LEANED THE FORECAST IN THIS DIRECTION FOR THE NEAR TERM. HAVE GONE WITH A BRIEF 4-6 HR PERIOD OF LIKELY SHRAS THIS MORNING MAINLY IN THE WARM SECTOR...WITH THE BEST RAIN CHANCES FROM THE EASTERN PIEDMONT/WEST OF RIC METRO EARLY THIS MORNING...REACHING THE I-95 CORRIDOR BY DAWN AND EVENTUALLY SOUTH CENTRAL VA/HAMPTON ROADS BY MID TO LATE MORNING. EXPECT LESS SHRA ACTIVITY THIS AFTN BEHIND DEPARTING SHORTWAVE AND HV THEREFORE CUT BACK ON POP FOR THE AFTN. EXPECT THE FRONT TO THE NORTH TO DROP SOUTH-SOUTHEAST IN BACKDOOR FASHION THIS MORNING, BRINGING ABOUT A WIND SHIFT TO THE NE FROM MIDDAY INTO THE AFTN. TEMPERATURES WILL STABILIZE TO FALL SLIGHTLY ACROSS THE NORTHERN NECK/EASTERN SHORE, AS TEMPERATURES WARM INTO THE LOW TO MID 70S IN THE WARM SECTOR OVER INLAND SECTIONS ALONG AND SOUTH OF THE VA/NC BORDER. FARTHER NORTH, LOOK FOR HIGHS IN THE U40S NEAR OCEAN CITY...LOW TO MID 50S OVER THE NORTHERN HALF OF THE AREA. EXPECT ANOTHER ROUND OF CONVECTION BY EARLY EVENING AS NEXT DISTURBANCE NOW OVER THE MID MO VLY TRANSLATES EAST. WILL INCREASE POP AGAIN BRIEFLY TONIGHT AS DISTURBANCE MOVES ALONG THE FRONT, IN PLACE ALONG OR JUST SOUTH OF THE VA/NC BORDER THIS EVENING. RAIN CHANCES DROP OFF AGAIN TONIGHT BEHIND THIS FEATURE OVERNIGHT. COOLER TONIGHT IN MOIST NE FLOW BEHIND THE FRONT, WITH LOWS IN THE 40S NE TO MID 50S SW SECTIONS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 448 AM EDT WED... THE FRONT WILL WEAKEN, WITH DEVELOPING SW FLOW EVENTUALLY PUSHING IT BACK NWD AS A WARM FRONT BY THU AFTN. HIGHS THU WILL RANGE FROM THE 50S ON THE LWR ERN SHORE TO THE U60S TO L70S WITH MORE TIME IN THE WARM SECTOR ACROSS FAR SWRN/WRN AREAS. HAVE MADE A MODEST DOWNWARD ADJUSTMENT ACROSS THE NORTHERN HALF OF THE AREA WITH ONGOING NE FLOW. POPS REMAIN IN CHANCE RANGE AS SEVERAL WEAK DISTURBANCES WILL RESULT IN TWO PERIODS FOR SCT SHRAS...MAINLY ACROSS THE NORTH IN THE MORNING AND ACROSS CENTRAL AND SOUTHERN ZONES ALONG THE FROTNAL ZONE. SFC LOW OVER THE PLAINS WILL TRACK NE INTO THE GREAT LAKES LATE THU/FRI WITH THE ASSOCIATED COLD FRONT CROSSING INTO OUR AREA FM THE WEST LATE IN THE DAY ON FRI/FRI NGT. CHANCES OF ADDITIONAL SHRAS/STORMS INCREASE FM W TO E THRU THE DAY FRI...WITH THE BEST CHANCE (60% POPS) IN THE AFTN/EVE HRS. SOME TSTMS MAY HAVE STRONG GUSTY WINDS AND HEAVY RAIN...AND HV MAINTAINED THIS MENTION IN THE HWO. MORE SUN/COMPRESSIONAL HEATING AHEAD OF FRONT WILL ALLOW FOR MUCH WARMER TEMPS ON FRIDAY AS THE REGION RETURNS INTO THE WARM SECTOR. LOOK FOR HIGHS IN THE MID 70S TO LOW 80S...WITH SOME MID 80S POSSIBLE ACROSS THE SOUTH IF CLEARING OCCURS A BIT QUICKER THAN PRESENTLY MODELED. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 446 PM EDT TUE... SFC CDFNT TO PUSH OFF THE CST AFT MDNGT FRI NGT...TO BE FOLLOWED BY HI PRES FM THE WNW BUILDING OVR THE RGN THIS WKND. CONTG HI CHC/LIKELY POPS FRI EVE...THEN TAPERING OFF W-E THROUGH LT FRI NGT/EARLY SAT MRNG. XPCG CLRG ON SAT AS DRYING AIR FM THE WNW SPREADS OVR THE RGN. THE HIGH MOVES OFF THE CST BY EARLY NEXT WK...RESULTING IN WNDS BECOMING SSW...AND MOISTURE GRADUALLY INCRSG. LO TEMPS FRI NGT FM THE M50S NW TO ARND 60F SE. HI TEMPS SAT IN THE L/M60S AT THE CST...TO L70S INLAND. LO TEMPS SAT NGT FM THE M40S NW TO L50S SE. HI TEMPS SUN NR 60F AT THE CST...TO 65 TO 70F ELSW. HI TEMPS MON/TUE FM THE M60S TO M70S. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... A BACKDOOR COLD FRONT IS SITUATED FROM NEAR THE ALBEMARLE SOUND WESTWARD ACROSS NRN NC EARLY THIS AFTERNOON. STRATUS IS WIDESPREAD ON THE COOL SIDE OF THE FRONT WITH OVC CIGS ~500FT. VSBY IS AVERAGING 2-3SM NEAR THE COAST TO > 6SM INLAND. IFR CIGS SHOULD PREVAIL THIS AFTERNOON AT ALL TERMINALS WITH THE EXCEPTION OF ECG...WHICH COULD OCCASIONALLY SCATTER OUT IN CLOSER PROXIMITY TO THE BOUNDARY. MOST OF THE AFTERNOON SHOULD BE RAIN-FREE. AN MCS OVER WV COULD REACH CENTRAL VA EARLY THIS EVENING LIKELY IN THE FORM OF SHRA WITH SOME EMBEDDED THUNDER POSSIBLE. OTHERWISE...THE BOUNDARY AGAIN SINKS S OVERNIGHT. EXPECT CIGS AND VSBY TO LOWER OVERNIGHT...WITH LIFR CONDITIONS LIKELY AT ALL SITES. SOME -RA IS POSSIBLE OVERNIGHT...BUT THERE IS ENOUGH UNCERTAINTY IN TIMING AND COVERAGE...SO OTHER THAN SOME -SHRA AT RIC THIS EVENING NO OTHER -RA HAS BEEN INCLUDED. CIGS SHOULD SLOWLY LIFT THURSDAY MORNING WITH MORE IMPROVEMENT DURING THE AFTERNOON AS THE BOUNDARY LIFTS BACK THROUGH THE REGION AS A WARM FRONT. A COLD FRONT CROSSES THE REGION FRIDAY AFTERNOON AND EVENING BRINGING SHRA/TSRA...ALONG WITH A BREEZY SSW WIND AHEAD OF THE FRONT. HIGH PRESSURE RETURNS SATURDAY AND SUNDAY AND MOVES OFFSHORE MONDAY. && .MARINE... SFC LOW PRESSURE WILL MOVE ACROSS THE WATERS INVOF A BACKDOOR COLD FRONT...WHICH IS DROPPING DOWN ACROSS THE VA EASTERN SHORE AS OF 300 AM THIS MORNING. WINDS ARE GENERALLY LIGHT FROM THE S-SW SOUTH OF THE FRONT...WITH BREEZY N-NE WINDS 10-20KT WITH GUSTS AROUND 25KT NORTH OF THE FRONT. AM ALREADY SEEING AN INCREASE IN WIND SPEEDS IN CHES BAY NORTH OF TANGIER ISLAND AND ALONG THE ATLANTIC COAST FROM FENWICK ISLAND TO PARRAMORE ISLAND. THE FRONT WILL GRADUALLY DROP SWD THROUGH THE REST OF TODAY...STALLING ACROSS THE CAROLINAS TONIGHT INTO THU. EXPECT NNE WINDS TO INCREASE OVER THE WATERS THROUGH TODAY WITH A BRIEF REPRIEVE TONIGHT. SPEEDS WILL GENERALLY BE 10-20KT OVER BAY/RIVERS/SOUND AND 15-25KT OVER THE COASTAL WATERS. SEAS ARE ALSO EXPECTED TO BUILD FROM 2-3FT TO 5-7FT NORTH OF CAPE CHARLES LIGHT...3-4FT SOUTH. ONSHORE FLOW PERSISTS ON THU WITH AN UPTICK IN WIND SPEEDS TO 10-15KT DURING THE AFTN/EARLY EVENING. SEAS SUBSIDE BELOW 5FT IN SRN WATERS BY THU AFTN...WHILE SEAS LINGER AROUND 4-5FT NORTH OF PARRAMORE ISLAND UNTIL EARLY EVENING. SCA FLAGS FROM FENWICK ISLAND TO CAPE CHARLES GO INTO EFFECT AT 600 AM THIS MORNING AND WILL MAINTAIN THAT START TIME BASED ON CURRENT OBSERVATIONS. THE STALLED FRONT LIFTS NWD AS A WARM FRONT THU NIGHT INTO EARLY FRI AND WINDS BECOME SLY. SEAS 2-3FT...WAVES 1-2FT. SPEEDS BEGIN TO INCREASE AROUND SUNRISE FRI MORNING AND WILL CONTINUE TO BE BREEZY DURING THE DAY AHEAD OF AN APPROACHING COLD FRONT. SPEEDS WILL AVERAGE 15-20KT (GUSTS UP TO 25KT OVER COASTAL WATERS). SEAS BUILD TO 3-4FT AND MAY REACH UP TO 5FT NEAR BUOY 44009 BY LATE FRI AFTN/EARLY EVENING. THE COLD FRONT CROSSES THE WATERS FRI NIGHT. THE COOLER AIRMASS BEHIND THE FRONT DOES NOT ARRIVE UNTIL DURING THE DAY ON SAT. A DAYTIME ARRIVAL OF COOLER AIR WILL DECREASE CHANCES FOR POST-FRONTAL SCA WINDS. EXPECT NW WINDS ON SAT AOB 15KT...DECREASING SAT NIGHT AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE WEST AND SETTLES OVER THE WATERS ON SUN/SUN NIGHT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THURSDAY FOR ANZ652-654. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ650. && $$ SYNOPSIS...MAM NEAR TERM...MAS/MAM SHORT TERM...MAS/MAM LONG TERM...ALB AVIATION...AJZ MARINE...ALB/BMD
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1201 PM EDT WED APR 8 2015 .SYNOPSIS... A BACKDOOR COLD FRONT WILL DROP SOUTH ACROSS THE LOCAL AREA EARLY TODAY THROUGH TONIGHT. THE FRONT THEN WEAKENS AND LIFTS BACK NORTH AS A WARM FRONT ON THURSDAY. ANOTHER COLD FRONT CROSSES THE REGION LATE FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... FORECAST UPDATED TO LWR POPS FOR THE REMAINDER OF THE DAY AND MAKE CHANGES TO HRLY TEMPS WHICH ARE QUITE TRICKY DUE TO A SLOWLY SAGGING COLD FRNT THRU THE AREA. PREVIOUS DISCUSSION... LATEST SURFACE ANALYSIS FEATURES SFC LOW PRESSURE IN PLACE OVER THE CENTRAL HIGH PLAINS, WITH A QUASI- STATIONARY FRONTAL BOUNDARY DRAPED ACROSS THE MID MS VLY OVER INTO THE OHIO VLY AND THE LWR EASTERN SHORE. NOTING SOME POCKETS OF SHRAS ACROSS THE AREA ON REGIONAL RADAR MOSAIC IN ASSOCIATION WITH A FEW WEAK DISTURBANCES. A FEW SCT SHRAS ARE CURRENTLY PUSHING EAST ON THE SOUTHERN PERIPHERY OF THE FRONTAL ZONE ACROSS THE LWR EASTERN SHORE THIS MORNING. MEANWHILE TO THE WEST, A MORE SUBSTANTIAL AREA OF SHRAS IN ASSOCIATION WITH DECAYING CONVECTIVE COMPLEX THAT ROLLED ACROSS THE OHIO RVR VALLEY LAST NIGHT IS CURRENTLY PUSHING FROM E WV/WESTERN VA OVER TO THE PIEDMONT IN THE FORM OF SOME LIGHT TO MODERATE RAIN SHRAS. LATEST HRRR AND TO A LESSER EXTENT THE 00Z NAM HAVE BEST HANDLED THIS FEATURE THUS FAR... AND HAVE THEREFORE LEANED THE FORECAST IN THIS DIRECTION FOR THE NEAR TERM. HAVE GONE WITH A BRIEF 4-6 HR PERIOD OF LIKELY SHRAS THIS MORNING MAINLY IN THE WARM SECTOR...WITH THE BEST RAIN CHANCES FROM THE EASTERN PIEDMONT/WEST OF RIC METRO EARLY THIS MORNING...REACHING THE I-95 CORRIDOR BY DAWN AND EVENTUALLY SOUTH CENTRAL VA/HAMPTON ROADS BY MID TO LATE MORNING. EXPECT LESS SHRA ACTIVITY THIS AFTN BEHIND DEPARTING SHORTWAVE AND HV THEREFORE CUT BACK ON POP FOR THE AFTN. EXPECT THE FRONT TO THE NORTH TO DROP SOUTH-SOUTHEAST IN BACKDOOR FASHION THIS MORNING, BRINGING ABOUT A WIND SHIFT TO THE NE FROM MIDDAY INTO THE AFTN. TEMPERATURES WILL STABILIZE TO FALL SLIGHTLY ACROSS THE NORTHERN NECK/EASTERN SHORE, AS TEMPERATURES WARM INTO THE LOW TO MID 70S IN THE WARM SECTOR OVER INLAND SECTIONS ALONG AND SOUTH OF THE VA/NC BORDER. FARTHER NORTH, LOOK FOR HIGHS IN THE U40S NEAR OCEAN CITY...LOW TO MID 50S OVER THE NORTHERN HALF OF THE AREA. EXPECT ANOTHER ROUND OF CONVECTION BY EARLY EVENING AS NEXT DISTURBANCE NOW OVER THE MID MO VLY TRANSLATES EAST. WILL INCREASE POP AGAIN BRIEFLY TONIGHT AS DISTURBANCE MOVES ALONG THE FRONT, IN PLACE ALONG OR JUST SOUTH OF THE VA/NC BORDER THIS EVENING. RAIN CHANCES DROP OFF AGAIN TONIGHT BEHIND THIS FEATURE OVERNIGHT. COOLER TONIGHT IN MOIST NE FLOW BEHIND THE FRONT, WITH LOWS IN THE 40S NE TO MID 50S SW SECTIONS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 448 AM EDT WED... THE FRONT WILL WEAKEN, WITH DEVELOPING SW FLOW EVENTUALLY PUSHING IT BACK NWD AS A WARM FRONT BY THU AFTN. HIGHS THU WILL RANGE FROM THE 50S ON THE LWR ERN SHORE TO THE U60S TO L70S WITH MORE TIME IN THE WARM SECTOR ACROSS FAR SWRN/WRN AREAS. HAVE MADE A MODEST DOWNWARD ADJUSTMENT ACROSS THE NORTHERN HALF OF THE AREA WITH ONGOING NE FLOW. POPS REMAIN IN CHANCE RANGE AS SEVERAL WEAK DISTURBANCES WILL RESULT IN TWO PERIODS FOR SCT SHRAS...MAINLY ACROSS THE NORTH IN THE MORNING AND ACROSS CENTRAL AND SOUTHERN ZONES ALONG THE FROTNAL ZONE. SFC LOW OVER THE PLAINS WILL TRACK NE INTO THE GREAT LAKES LATE THU/FRI WITH THE ASSOCIATED COLD FRONT CROSSING INTO OUR AREA FM THE WEST LATE IN THE DAY ON FRI/FRI NGT. CHANCES OF ADDITIONAL SHRAS/STORMS INCREASE FM W TO E THRU THE DAY FRI...WITH THE BEST CHANCE (60% POPS) IN THE AFTN/EVE HRS. SOME TSTMS MAY HAVE STRONG GUSTY WINDS AND HEAVY RAIN...AND HV MAINTAINED THIS MENTION IN THE HWO. MORE SUN/COMPRESSIONAL HEATING AHEAD OF FRONT WILL ALLOW FOR MUCH WARMER TEMPS ON FRIDAY AS THE REGION RETURNS INTO THE WARM SECTOR. LOOK FOR HIGHS IN THE MID 70S TO LOW 80S...WITH SOME MID 80S POSSIBLE ACROSS THE SOUTH IF CLEARING OCCURS A BIT QUICKER THAN PRESENTLY MODELED. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 446 PM EDT TUE... SFC CDFNT TO PUSH OFF THE CST AFT MDNGT FRI NGT...TO BE FOLLOWED BY HI PRES FM THE WNW BUILDING OVR THE RGN THIS WKND. CONTG HI CHC/LIKELY POPS FRI EVE...THEN TAPERING OFF W-E THROUGH LT FRI NGT/EARLY SAT MRNG. XPCG CLRG ON SAT AS DRYING AIR FM THE WNW SPREADS OVR THE RGN. THE HIGH MOVES OFF THE CST BY EARLY NEXT WK...RESULTING IN WNDS BECOMING SSW...AND MOISTURE GRADUALLY INCRSG. LO TEMPS FRI NGT FM THE M50S NW TO ARND 60F SE. HI TEMPS SAT IN THE L/M60S AT THE CST...TO L70S INLAND. LO TEMPS SAT NGT FM THE M40S NW TO L50S SE. HI TEMPS SUN NR 60F AT THE CST...TO 65 TO 70F ELSW. HI TEMPS MON/TUE FM THE M60S TO M70S. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... A BACKDOOR COLD FRONT IS DROPPING SOUTH INTO FAR NERN COUNTIES OF THE FA EARLY THIS MORNING. VARIABLE BR WITH VISIBILITIES RANGING FROM 1-5SM ACROSS THE REGION...WITH POCKETS OF FG WITH VISIBILITIES FROM 1/4-1/2SM. NORTH OF THE FRONTAL BOUNDARY...WINDS ARE NE AROUND 10-15KT. SOUTH OF THE BOUNDARY...WINDS ARE LIGHT FROM THE SOUTH. AS THE FRONT SAGS SWD TODAY...EXPECT SIMILAR WIND SHIFTS AND SPEEDS AS THE DAY PROGRESSES. MEANWHILE...A DECENT SWATH OF RAIN SHOWERS ARE PUSHING WWD INTO THE ERN PIEDMONT AS OF 08/0800Z. RAIN WILL CONTINUE TO PUSH EWD ACROSS THE REGION TODAY...BECOMING MORE FOCUSED ACROSS THE SOUTH WHERE THE FRONTAL BOUNDARY IS LOCATED. EXPECT A COMBINATION OF MVFR/IFR CIGS IN RAIN SHOWERS TODAY. PRECIP COMES TO AN END BY MID TO LATE EVENING...WITH AREAS OF FOG EXPECTED TO DEVELOP QUICKLY OVERNIGHT. CIGS ARE EXPECTED TO BE AROUND 400FT AGL WITH VARIABLE VISIBILITIES IN IFR/MVFR CATEGORIES. THE BACKDOOR FRONT STALLS ACROSS THE CAROLINAS WED NIGHT/THU AND CONDITIONS SHOULD BE SLOW TO IMPROVE THU MORNING. THE FRONT LIFTS NWD THROUGH THE REGION THU NIGHT/EARLY FRI MORNING. BREEZY CONDITIONS ANTICIPATED FRI AHEAD OF AN APPROACHING COLD FRONT WHICH IS EXPECTED TO CROSS THE REGION FRI EVENING. HIGH PRESSURE RETURNS TO THE REGION SAT/SUN. && .MARINE... SFC LOW PRESSURE WILL MOVE ACROSS THE WATERS INVOF A BACKDOOR COLD FRONT...WHICH IS DROPPING DOWN ACROSS THE VA EASTERN SHORE AS OF 300 AM THIS MORNING. WINDS ARE GENERALLY LIGHT FROM THE S-SW SOUTH OF THE FRONT...WITH BREEZY N-NE WINDS 10-20KT WITH GUSTS AROUND 25KT NORTH OF THE FRONT. AM ALREADY SEEING AN INCREASE IN WIND SPEEDS IN CHES BAY NORTH OF TANGIER ISLAND AND ALONG THE ATLANTIC COAST FROM FENWICK ISLAND TO PARRAMORE ISLAND. THE FRONT WILL GRADUALLY DROP SWD THROUGH THE REST OF TODAY...STALLING ACROSS THE CAROLINAS TONIGHT INTO THU. EXPECT NNE WINDS TO INCREASE OVER THE WATERS THROUGH TODAY WITH A BRIEF REPRIEVE TONIGHT. SPEEDS WILL GENERALLY BE 10-20KT OVER BAY/RIVERS/SOUND AND 15-25KT OVER THE COASTAL WATERS. SEAS ARE ALSO EXPECTED TO BUILD FROM 2-3FT TO 5-7FT NORTH OF CAPE CHARLES LIGHT...3-4FT SOUTH. ONSHORE FLOW PERSISTS ON THU WITH AN UPTICK IN WIND SPEEDS TO 10-15KT DURING THE AFTN/EARLY EVENING. SEAS SUBSIDE BELOW 5FT IN SRN WATERS BY THU AFTN...WHILE SEAS LINGER AROUND 4-5FT NORTH OF PARRAMORE ISLAND UNTIL EARLY EVENING. SCA FLAGS FROM FENWICK ISLAND TO CAPE CHARLES GO INTO EFFECT AT 600 AM THIS MORNING AND WILL MAINTAIN THAT START TIME BASED ON CURRENT OBSERVATIONS. THE STALLED FRONT LIFTS NWD AS A WARM FRONT THU NIGHT INTO EARLY FRI AND WINDS BECOME SLY. SEAS 2-3FT...WAVES 1-2FT. SPEEDS BEGIN TO INCREASE AROUND SUNRISE FRI MORNING AND WILL CONTINUE TO BE BREEZY DURING THE DAY AHEAD OF AN APPROACHING COLD FRONT. SPEEDS WILL AVERAGE 15-20KT (GUSTS UP TO 25KT OVER COASTAL WATERS). SEAS BUILD TO 3-4FT AND MAY REACH UP TO 5FT NEAR BUOY 44009 BY LATE FRI AFTN/EARLY EVENING. THE COLD FRONT CROSSES THE WATERS FRI NIGHT. THE COOLER AIRMASS BEHIND THE FRONT DOES NOT ARRIVE UNTIL DURING THE DAY ON SAT. A DAYTIME ARRIVAL OF COOLER AIR WILL DECREASE CHANCES FOR POST-FRONTAL SCA WINDS. EXPECT NW WINDS ON SAT AOB 15KT...DECREASING SAT NIGHT AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE WEST AND SETTLES OVER THE WATERS ON SUN/SUN NIGHT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THURSDAY FOR ANZ652-654. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ650. && $$ SYNOPSIS...MAM NEAR TERM...MAS/MAM SHORT TERM...MAS/MAM LONG TERM...ALB AVIATION...BMD MARINE...ALB/BMD
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
449 AM EDT WED APR 8 2015 .SYNOPSIS... A BACKDOOR COLD FRONT WILL DROP SOUTH ACROSS THE LOCAL AREA EARLY TODAY THROUGH TONIGHT. THE FRONT THEN WEAKENS AND LIFTS BACK NORTH AS A WARM FRONT ON THURSDAY. ANOTHER COLD FRONT CROSSES THE REGION LATE FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 405 AM EDT WED... LATEST SURFACE ANALYSIS FEATURES SFC LOW PRESSURE IN PLACE OVER THE CENTRAL HIGH PLAINS, WITH A QUASI-STATIONARY FRONTAL BOUNDARY DRAPED ACROSS THE MID MS VLY OVER INTO THE OHIO VLY AND THE LWR EASTERN SHORE. NOTING SOME POCKETS OF SHRAS ACROSS THE AREA ON REGIONAL RADAR MOSAIC IN ASSOCIATION WITH A FEW WEAK DISTURBANCES. A FEW SCT SHRAS ARE CURRENTLY PUSHING EAST ON THE SOUTHERN PERIPHERY OF THE FRONTAL ZONE ACROSS THE LWR EASTERN SHORE THIS MORNING. MEANWHILE TO THE WEST, A MORE SUBSTANTIAL AREA OF SHRAS IN ASSOCIATION WITH DECAYING CONVECTIVE COMPLEX THAT ROLLED ACROSS THE OHIO RVR VALLEY LAST NIGHT IS CURRENTLY PUSHING FROM E WV/WESTERN VA OVER TO THE PIEDMONT IN THE FORM OF SOME LIGHT TO MODERATE RAIN SHRAS. LATEST HRRR AND TO A LESSER EXTENT THE 00Z NAM HAVE BEST HANDLED THIS FEATURE THUS FAR... AND HAVE THEREFORE LEANED THE FORECAST IN THIS DIRECTION FOR THE NEAR TERM. HAVE GONE WITH A BRIEF 4-6 HR PERIOD OF LIKELY SHRAS THIS MORNING MAINLY IN THE WARM SECTOR...WITH THE BEST RAIN CHANCES FROM THE EASTERN PIEDMONT/WEST OF RIC METRO EARLY THIS MORNING...REACHING THE I-95 CORRIDOR BY DAWN AND EVENTUALLY SOUTH CENTRAL VA/HAMPTON ROADS BY MID TO LATE MORNING. EXPECT LESS SHRA ACTIVITY THIS AFTN BEHIND DEPARTING SHORTWAVE AND HV THEREFORE CUT BACK ON POP FOR THE AFTN. EXPECT THE FRONT TO THE NORTH TO DROP SOUTH-SOUTHEAST IN BACKDOOR FASHION THIS MORNING, BRINGING ABOUT A WIND SHIFT TO THE NE FROM MIDDAY INTO THE AFTN. TEMPERATURES WILL STABILIZE TO FALL SLIGHTLY ACROSS THE NORTHERN NECK/EASTERN SHORE, AS TEMPERATURES WARM INTO THE LOW TO MID 70S IN THE WARM SECTOR OVER INLAND SECTIONS ALONG AND SOUTH OF THE VA/NC BORDER. FARTHER NORTH, LOOK FOR HIGHS IN THE U40S NEAR OCEAN CITY...LOW TO MID 50S OVER THE NORTHERN HALF OF THE AREA. EXPECT ANOTHER ROUND OF CONVECTION BY EARLY EVENING AS NEXT DISTURBANCE NOW OVER THE MID MO VLY TRANSLATES EAST. WILL INCREASE POP AGAIN BRIEFLY TONIGHT AS DISTURBANCE MOVES ALONG THE FRONT, IN PLACE ALONG OR JUST SOUTH OF THE VA/NC BORDER THIS EVENING. RAIN CHANCES DROP OFF AGAIN TONIGHT BEHIND THIS FEATURE OVERNIGHT. COOLER TONIGHT IN MOIST NE FLOW BEHIND THE FRONT, WITH LOWS IN THE 40S NE TO MID 50S SW SECTIONS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 448 AM EDT WED... THE FRONT WILL WEAKEN, WITH DEVELOPING SW FLOW EVENTUALLY PUSHING IT BACK NWD AS A WARM FRONT BY THU AFTN. HIGHS THU WILL RANGE FROM THE 50S ON THE LWR ERN SHORE TO THE U60S TO L70S WITH MORE TIME IN THE WARM SECTOR ACROSS FAR SWRN/WRN AREAS. HAVE MADE A MODEST DOWNWARD ADJUSTMENT ACROSS THE NORTHERN HALF OF THE AREA WITH ONGOING NE FLOW. POPS REMAIN IN CHANCE RANGE AS SEVERAL WEAK DISTURBANCES WILL RESULT IN TWO PERIODS FOR SCT SHRAS...MAINLY ACROSS THE NORTH IN THE MORNING AND ACROSS CENTRAL AND SOUTHERN ZONES ALONG THE FROTNAL ZONE. SFC LOW OVER THE PLAINS WILL TRACK NE INTO THE GREAT LAKES LATE THU/FRI WITH THE ASSOCIATED COLD FRONT CROSSING INTO OUR AREA FM THE WEST LATE IN THE DAY ON FRI/FRI NGT. CHANCES OF ADDITIONAL SHRAS/STORMS INCREASE FM W TO E THRU THE DAY FRI...WITH THE BEST CHANCE (60% POPS) IN THE AFTN/EVE HRS. SOME TSTMS MAY HAVE STRONG GUSTY WINDS AND HEAVY RAIN...AND HV MAINTAINED THIS MENTION IN THE HWO. MORE SUN/COMPRESSIONAL HEATING AHEAD OF FRONT WILL ALLOW FOR MUCH WARMER TEMPS ON FRIDAY AS THE REGION RETURNS INTO THE WARM SECTOR. LOOK FOR HIGHS IN THE MID 70S TO LOW 80S...WITH SOME MID 80S POSSIBLE ACROSS THE SOUTH IF CLEARING OCCURS A BIT QUICKER THAN PRESENTLY MODELED. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 446 PM EDT TUE... SFC CDFNT TO PUSH OFF THE CST AFT MDNGT FRI NGT...TO BE FOLLOWED BY HI PRES FM THE WNW BUILDING OVR THE RGN THIS WKND. CONTG HI CHC/LIKELY POPS FRI EVE...THEN TAPERING OFF W-E THROUGH LT FRI NGT/EARLY SAT MRNG. XPCG CLRG ON SAT AS DRYING AIR FM THE WNW SPREADS OVR THE RGN. THE HIGH MOVES OFF THE CST BY EARLY NEXT WK...RESULTING IN WNDS BECOMING SSW...AND MOISTURE GRADUALLY INCRSG. LO TEMPS FRI NGT FM THE M50S NW TO ARND 60F SE. HI TEMPS SAT IN THE L/M60S AT THE CST...TO L70S INLAND. LO TEMPS SAT NGT FM THE M40S NW TO L50S SE. HI TEMPS SUN NR 60F AT THE CST...TO 65 TO 70F ELSW. HI TEMPS MON/TUE FM THE M60S TO M70S. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... A BACKDOOR COLD FRONT IS DROPPING SOUTH INTO FAR NERN COUNTIES OF THE FA EARLY THIS MORNING. VARIABLE BR WITH VISIBILITIES RANGING FROM 1-5SM ACROSS THE REGION...WITH POCKETS OF FG WITH VISIBILITIES FROM 1/4-1/2SM. NORTH OF THE FRONTAL BOUNDARY...WINDS ARE NE AROUND 10-15KT. SOUTH OF THE BOUNDARY...WINDS ARE LIGHT FROM THE SOUTH. AS THE FRONT SAGS SWD TODAY...EXPECT SIMILAR WIND SHIFTS AND SPEEDS AS THE DAY PROGRESSES. MEANWHILE...A DECENT SWATH OF RAIN SHOWERS ARE PUSHING WWD INTO THE ERN PIEDMONT AS OF 08/0800Z. RAIN WILL CONTINUE TO PUSH EWD ACROSS THE REGION TODAY...BECOMING MORE FOCUSED ACROSS THE SOUTH WHERE THE FRONTAL BOUNDARY IS LOCATED. EXPECT A COMBINATION OF MVFR/IFR CIGS IN RAIN SHOWERS TODAY. PRECIP COMES TO AN END BY MID TO LATE EVENING...WITH AREAS OF FOG EXPECTED TO DEVELOP QUICKLY OVERNIGHT. CIGS ARE EXPECTED TO BE AROUND 400FT AGL WITH VARIABLE VISIBILITIES IN IFR/MVFR CATEGORIES. THE BACKDOOR FRONT STALLS ACROSS THE CAROLINAS WED NIGHT/THU AND CONDITIONS SHOULD BE SLOW TO IMPROVE THU MORNING. THE FRONT LIFTS NWD THROUGH THE REGION THU NIGHT/EARLY FRI MORNING. BREEZY CONDITIONS ANTICIPATED FRI AHEAD OF AN APPROACHING COLD FRONT WHICH IS EXPECTED TO CROSS THE REGION FRI EVENING. HIGH PRESSURE RETURNS TO THE REGION SAT/SUN. && .MARINE... SFC LOW PRESSURE WILL MOVE ACROSS THE WATERS INVOF A BACKDOOR COLD FRONT...WHICH IS DROPPING DOWN ACROSS THE VA EASTERN SHORE AS OF 300 AM THIS MORNING. WINDS ARE GENERALLY LIGHT FROM THE S-SW SOUTH OF THE FRONT...WITH BREEZY N-NE WINDS 10-20KT WITH GUSTS AROUND 25KT NORTH OF THE FRONT. AM ALREADY SEEING AN INCREASE IN WIND SPEEDS IN CHES BAY NORTH OF TANGIER ISLAND AND ALONG THE ATLANTIC COAST FROM FENWICK ISLAND TO PARRAMORE ISLAND. THE FRONT WILL GRADUALLY DROP SWD THROUGH THE REST OF TODAY...STALLING ACROSS THE CAROLINAS TONIGHT INTO THU. EXPECT NNE WINDS TO INCREASE OVER THE WATERS THROUGH TODAY WITH A BRIEF REPRIEVE TONIGHT. SPEEDS WILL GENERALLY BE 10-20KT OVER BAY/RIVERS/SOUND AND 15-25KT OVER THE COASTAL WATERS. SEAS ARE ALSO EXPECTED TO BUILD FROM 2-3FT TO 5-7FT NORTH OF CAPE CHARLES LIGHT...3-4FT SOUTH. ONSHORE FLOW PERSISTS ON THU WITH AN UPTICK IN WIND SPEEDS TO 10-15KT DURING THE AFTN/EARLY EVENING. SEAS SUBSIDE BELOW 5FT IN SRN WATERS BY THU AFTN...WHILE SEAS LINGER AROUND 4-5FT NORTH OF PARRAMORE ISLAND UNTIL EARLY EVENING. SCA FLAGS FROM FENWICK ISLAND TO CAPE CHARLES GO INTO EFFECT AT 600 AM THIS MORNING AND WILL MAINTAIN THAT START TIME BASED ON CURRENT OBSERVATIONS. THE STALLED FRONT LIFTS NWD AS A WARM FRONT THU NIGHT INTO EARLY FRI AND WINDS BECOME SLY. SEAS 2-3FT...WAVES 1-2FT. SPEEDS BEGIN TO INCREASE AROUND SUNRISE FRI MORNING AND WILL CONTINUE TO BE BREEZY DURING THE DAY AHEAD OF AN APPROACHING COLD FRONT. SPEEDS WILL AVERAGE 15-20KT (GUSTS UP TO 25KT OVER COASTAL WATERS). SEAS BUILD TO 3-4FT AND MAY REACH UP TO 5FT NEAR BUOY 44009 BY LATE FRI AFTN/EARLY EVENING. THE COLD FRONT CROSSES THE WATERS FRI NIGHT. THE COOLER AIRMASS BEHIND THE FRONT DOES NOT ARRIVE UNTIL DURING THE DAY ON SAT. A DAYTIME ARRIVAL OF COOLER AIR WILL DECREASE CHANCES FOR POST-FRONTAL SCA WINDS. EXPECT NW WINDS ON SAT AOB 15KT...DECREASING SAT NIGHT AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE WEST AND SETTLES OVER THE WATERS ON SUN/SUN NIGHT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 2 PM EDT THURSDAY FOR ANZ652-654. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ650. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...MAS/MAM LONG TERM...ALB AVIATION...BMD MARINE...ALB/BMD
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
420 AM EDT WED APR 8 2015 .SYNOPSIS... A BACKDOOR COLD FRONT WILL DROP SOUTH ACROSS THE LOCAL AREA EARLY TODAY THROUGH TONIGHT. THE FRONT THEN WEAKENS AND LIFTS BACK NORTH AS A WARM FRONT ON THURSDAY. ANOTHER COLD FRONT CROSSES THE REGION LATE FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 405 AM EDT... LATEST SURFACE ANALYSIS FEATURES SFC LOW PRESSURE IN PLACE OVER THE CENTRAL HIGH PLAINS, WITH A QUASI- STATIONARY FRONTAL BOUNDARY DRAPED ACROSS THE MID MS VLY OVER INTO THE OHIO VLY AND THE LWR EASTERN SHORE. NOTING SOME POCKETS OF SHRAS ACROSS THE AREA ON REGIONAL RADAR MOSAIC IN ASSOCIATION WITH A FEW WEAK DISTURBANCES. NOTING A FEW SCT SHRAS PUSHING ACROSS THE LWR EASTERN SHORE THIS MORNING ALONG THE FRONT. MEANWHILE, TO THE WEST A MORE SUBSTANTIAL AREA OF SHRAS IN ASSOCIATION WITH DECAYING CONVECTIVE COMPLEX THAT ROLLED ACROSS THE OHIO RVR VALLEY LAST NIGHT. THIS ACTIVITY IS PUSHING FROM E WV/WESTERN VA OVER TO THE PIEDMONT THIS MORNING IN THE FORM OF SOME LIGHT TO MODERATE RAIN SHRAS. LATEST HRRR AND TO A LESSER EXTENT THE 00Z NAM HAVE BEST HANDLED THIS FEATURE THUS FAR... AND HAVE THEREFORE LEANED THE FORECAST IN THIS DIRECTION FOR THE NEAR TERM. HAVE GONE WITH A BRIEF PERIOD OF LIKELY SHRAS THIS MORNING MAINLY IN THE WARM SECTOR... WITH THE BEST RAIN CHANCES FROM THE EASTERN PIEDMONT/WEST OF RIC METRO EARLY THIS MORNING...REACHING THE I-95 CORRIDOR BY DAWN AND EVENTUALLY SOUTH CENTRAL VA/HAMPTON ROADS BY MID TO LATE MORNING. EXPECT LESS SHRA ACTIVITY THIS AFTN BEHIND DEPARTING SHORTWAVE AND HV THEREFORE CUT BACK ON POP FOR THE AFTN. EXPECT THE FRONT TO THE NORTH TO DROP SOUTH- SOUTHEAST IN BACKDOOR FASHION THIS MORNING, BRINGING ABOUT A WIND SHIFT TO THE NE FROM MIDDAY INTO THE AFTN. TEMPERATURES WILL STABILIZE TO FALL SLIGHTLY ACROSS THE NORTHERN NECK/EASTERN SHORE, AS TEMPERATURES WARM INTO THE LOW TO MID 70S IN THE WARM SECTOR OVER INLAND SECTIONS ALONG AND SOUTH OF THE VA/NC BORDER. FARTHER NORTH, LOOK FOR HIGHS IN THE U40S NEAR OCEAN CITY...LOW TO MID 50S OVER THE NORTHERN HALF OF THE AREA. EXPECT ANOTHER ROUND OF CONVECTION BY EARLY EVENING AS NEXT DISTURBANCE NOW OVER THE MID MO VLY TRANSLATES EAST. WILL INCREASE POP AGAIN BRIEFLY TONIGHT AS DISTURBANCE MOVES ALONG THE FRONT, IN PLACE ALONG OR JUST SOUTH OF THE VA/NC BORDER THIS EVENING. RAIN CHANCES DROP OFF AGAIN TONIGHT BEHIND THIS FEATURE OVERNIGHT. COOLER TONIGHT IN MOIST NE FLOW BEHIND THE FRONT, WITH LOWS IN THE 40S NE TO MID 50S SW SECTIONS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... THE FRONT WILL WEAKEN AND SLOWLY PUSH BACK NWD AS A WARM FRONT ON THU...WITH HIGHS RANGING FM THE 50S LWR ERN SHORE TO THE 70S IN THE WARM SECTOR ACROSS FAR SRN/WRN AREAS. NEXT COLD FRONT APPROACHES FM THE W ON FRI. CHANCES OF SHRAS/TSTMS INCREASE FM W TO E THRU THE DAY...WITH THE BEST CHANCE (60% POPS) IN THE AFTN/EVE HRS. SOME TSTMS MAY HAVE STRONG GUSTY WINDS AND HEAVY RAIN...MAINTAINED MENTION IN THE HWO. TEMPS WILL BE MUCH HIGHER THAN PREVIOUS DAYS WITH THE REGION IN THE WARM SECTOR...HIGHS IN THE MID 70S TO MID 80S. && .LONG TERM /SATURDAY THROUGH TUESDAY/... SFC CDFNT TO PUSH OFF THE CST AFT MDNGT FRI NGT...TO BE FOLLOWED BY HI PRES FM THE WNW BUILDING OVR THE RGN THIS WKND. CONTG HI CHC/LIKELY POPS FRI EVE...THEN TAPERING OFF W-E THROUGH LT FRI NGT/EARLY SAT MRNG. XPCG CLRG ON SAT AS DRYING AIR FM THE WNW SPREADS OVR THE RGN. THE HIGH MOVES OFF THE CST BY EARLY NEXT WK...RESULTING IN WNDS BECOMING SSW...AND MOISTURE GRADUALLY INCRSG. LO TEMPS FRI NGT FM THE M50S NW TO ARND 60F SE. HI TEMPS SAT IN THE L/M60S AT THE CST...TO L70S INLAND. LO TEMPS SAT NGT FM THE M40S NW TO L50S SE. HI TEMPS SUN NR 60F AT THE CST...TO 65 TO 70F ELSW. HI TEMPS MON/TUE FM THE M60S TO M70S. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... A BACKDOOR COLD FRONT IS DROPPING SOUTH INTO FAR NERN COUNTIES OF THE FA EARLY THIS MORNING. VARIABLE BR WITH VISIBILITIES RANGING FROM 1-5SM ACROSS THE REGION...WITH POCKETS OF FG WITH VISIBILITIES FROM 1/4-1/2SM. NORTH OF THE FRONTAL BOUNDARY...WINDS ARE NE AROUND 10-15KT. SOUTH OF THE BOUNDARY...WINDS ARE LIGHT FROM THE SOUTH. AS THE FRONT SAGS SWD TODAY...EXPECT SIMILAR WIND SHIFTS AND SPEEDS AS THE DAY PROGRESSES. MEANWHILE...A DECENT SWATH OF RAIN SHOWERS ARE PUSHING WWD INTO THE ERN PIEDMONT AS OF 08/0800Z. RAIN WILL CONTINUE TO PUSH EWD ACROSS THE REGION TODAY...BECOMING MORE FOCUSED ACROSS THE SOUTH WHERE THE FRONTAL BOUNDARY IS LOCATED. EXPECT A COMBINATION OF MVFR/IFR CIGS IN RAIN SHOWERS TODAY. PRECIP COMES TO AN END BY MID TO LATE EVENING...WITH AREAS OF FOG EXPECTED TO DEVELOP QUICKLY OVERNIGHT. CIGS ARE EXPECTED TO BE AROUND 400FT AGL WITH VARIABLE VISIBILITIES IN IFR/MVFR CATEGORIES. THE BACKDOOR FRONT STALLS ACROSS THE CAROLINAS WED NIGHT/THU AND CONDITIONS SHOULD BE SLOW TO IMPROVE THU MORNING. THE FRONT LIFTS NWD THROUGH THE REGION THU NIGHT/EARLY FRI MORNING. BREEZY CONDITIONS ANTICIPATED FRI AHEAD OF AN APPROACHING COLD FRONT WHICH IS EXPECTED TO CROSS THE REGION FRI EVENING. HIGH PRESSURE RETURNS TO THE REGION SAT/SUN. && .MARINE... SFC LOW PRESSURE WILL MOVE ACROSS THE WATERS INVOF A BACKDOOR COLD FRONT...WHICH IS DROPPING DOWN ACROSS THE VA EASTERN SHORE AS OF 300 AM THIS MORNING. WINDS ARE GENERALLY LIGHT FROM THE S-SW SOUTH OF THE FRONT...WITH BREEZY N-NE WINDS 10-20KT WITH GUSTS AROUND 25KT NORTH OF THE FRONT. AM ALREADY SEEING AN INCREASE IN WIND SPEEDS IN CHES BAY NORTH OF TANGIER ISLAND AND ALONG THE ATLANTIC COAST FROM FENWICK ISLAND TO PARRAMORE ISLAND. THE FRONT WILL GRADUALLY DROP SWD THROUGH THE REST OF TODAY...STALLING ACROSS THE CAROLINAS TONIGHT INTO THU. EXPECT NNE WINDS TO INCREASE OVER THE WATERS THROUGH TODAY WITH A BRIEF REPRIEVE TONIGHT. SPEEDS WILL GENERALLY BE 10-20KT OVER BAY/RIVERS/SOUND AND 15-25KT OVER THE COASTAL WATERS. SEAS ARE ALSO EXPECTED TO BUILD FROM 2-3FT TO 5-7FT NORTH OF CAPE CHARLES LIGHT...3-4FT SOUTH. ONSHORE FLOW PERSISTS ON THU WITH AN UPTICK IN WIND SPEEDS TO 10-15KT DURING THE AFTN/EARLY EVENING. SEAS SUBSIDE BELOW 5FT IN SRN WATERS BY THU AFTN...WHILE SEAS LINGER AROUND 4-5FT NORTH OF PARRAMORE ISLAND UNTIL EARLY EVENING. SCA FLAGS FROM FENWICK ISLAND TO CAPE CHARLES GO INTO EFFECT AT 600 AM THIS MORNING AND WILL MAINTAIN THAT START TIME BASED ON CURRENT OBSERVATIONS. THE STALLED FRONT LIFTS NWD AS A WARM FRONT THU NIGHT INTO EARLY FRI AND WINDS BECOME SLY. SEAS 2-3FT...WAVES 1-2FT. SPEEDS BEGIN TO INCREASE AROUND SUNRISE FRI MORNING AND WILL CONTINUE TO BE BREEZY DURING THE DAY AHEAD OF AN APPROACHING COLD FRONT. SPEEDS WILL AVERAGE 15-20KT (GUSTS UP TO 25KT OVER COASTAL WATERS). SEAS BUILD TO 3-4FT AND MAY REACH UP TO 5FT NEAR BUOY 44009 BY LATE FRI AFTN/EARLY EVENING. THE COLD FRONT CROSSES THE WATERS FRI NIGHT. THE COOLER AIRMASS BEHIND THE FRONT DOES NOT ARRIVE UNTIL DURING THE DAY ON SAT. A DAYTIME ARRIVAL OF COOLER AIR WILL DECREASE CHANCES FOR POST-FRONTAL SCA WINDS. EXPECT NW WINDS ON SAT AOB 15KT...DECREASING SAT NIGHT AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE WEST AND SETTLES OVER THE WATERS ON SUN/SUN NIGHT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 2 PM EDT THURSDAY FOR ANZ652-654. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ650. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...MAS/MAM LONG TERM...ALB AVIATION...BMD MARINE...BMD
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
405 AM EDT WED APR 8 2015 .SYNOPSIS... A BACKDOOR COLD FRONT WILL DROP SOUTH ACROSS THE LOCAL AREA EARLY TODAY THROUGH TONIGHT. THE FRONT THEN WEAKENS AND LIFTS BACK NORTH AS A WARM FRONT ON THURSDAY. ANOTHER COLD FRONT CROSSES THE REGION LATE FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 405 AM EDT... LATEST SURFACE ANALYSIS FEATURES SFC LOW PRESSURE IN PLACE OVER THE CENTRAL HIGH PLAINS, WITH A QUASI- STATIONARY FRONTAL BOUNDARY DRAPED ACROSS THE MID MS VLY OVER INTO THE OHIO VLY AND THE LWR EASTERN SHORE. NOTING SOME POCKETS OF SHRAS ACROSS THE AREA ON REGIONAL RADAR MOSAIC IN ASSOCIATION WITH A FEW WEAK DISTURBANCES. NOTING A FEW SCT SHRAS PUSHING ACROSS THE LWR EASTERN SHORE THIS MORNING ALONG THE FRONT. MEANWHILE, TO THE WEST A MORE SUBSTANTIAL AREA OF SHRAS IN ASSOCIATION WITH DECAYING CONVECTIVE COMPLEX THAT ROLLED ACROSS THE OHIO RVR VALLEY LAST NIGHT. THIS ACTIVITY IS PUSHING FROM E WV/WESTERN VA OVER TO THE PIEDMONT THIS MORNING IN THE FORM OF SOME LIGHT TO MODERATE RAIN SHRAS. LATEST HRRR AND TO A LESSER EXTENT THE 00Z NAM HAVE BEST HANDLED THIS FEATURE THUS FAR... AND HAVE THEREFORE LEANED THE FORECAST IN THIS DIRECTION FOR THE NEAR TERM. HAVE GONE WITH A BRIEF PERIOD OF LIKELY SHRAS THIS MORNING MAINLY IN THE WARM SECTOR... WITH THE BEST RAIN CHANCES FROM THE EASTERN PIEDMONT/WEST OF RIC METRO EARLY THIS MORNING...REACHING THE I-95 CORRIDOR BY DAWN AND EVENTUALLY SOUTH CENTRAL VA/HAMPTON ROADS BY MID TO LATE MORNING. EXPECT LESS SHRA ACTIVITY THIS AFTN BEHIND DEPARTING SHORTWAVE AND HV THEREFORE CUT BACK ON POP FOR THE AFTN. EXPECT THE FRONT TO THE NORTH TO DROP SOUTH- SOUTHEAST IN BACKDOOR FASHION THIS MORNING, BRINGING ABOUT A WIND SHIFT TO THE NE FROM MIDDAY INTO THE AFTN. TEMPERATURES WILL STABILIZE TO FALL SLIGHTLY ACROSS THE NORTHERN NECK/EASTERN SHORE, AS TEMPERATURES WARM INTO THE LOW TO MID 70S IN THE WARM SECTOR OVER INLAND SECTIONS ALONG AND SOUTH OF THE VA/NC BORDER. FARTHER NORTH, LOOK FOR HIGHS IN THE U40S NEAR OCEAN CITY...LOW TO MID 50S OVER THE NORTHERN HALF OF THE AREA. EXPECT ANOTHER ROUND OF CONVECTION BY EARLY EVENING AS NEXT DISTURBANCE NOW OVER THE MID MO VLY TRANSLATES EAST. WILL INCREASE POP AGAIN BRIEFLY TONIGHT AS DISTURBANCE MOVES ALONG THE FRONT, IN PLACE ALONG OR JUST SOUTH OF THE VA/NC BORDER THIS EVENING. RAIN CHANCES DROP OFF AGAIN TONIGHT BEHIND THIS FEATURE OVERNIGHT. COOLER TONIGHT IN MOIST NE FLOW BEHIND THE FRONT, WITH LOWS IN THE 40S NE TO MID 50S SW SECTIONS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... THE FRONT WILL WEAKEN AND SLOWLY PUSH BACK NWD AS A WARM FRONT ON THU...WITH HIGHS RANGING FM THE 50S LWR ERN SHORE TO THE 70S IN THE WARM SECTOR ACROSS FAR SRN/WRN AREAS. NEXT COLD FRONT APPROACHES FM THE W ON FRI. CHANCES OF SHRAS/TSTMS INCREASE FM W TO E THRU THE DAY...WITH THE BEST CHANCE (60% POPS) IN THE AFTN/EVE HRS. SOME TSTMS MAY HAVE STRONG GUSTY WINDS AND HEAVY RAIN...MAINTAINED MENTION IN THE HWO. TEMPS WILL BE MUCH HIGHER THAN PREVIOUS DAYS WITH THE REGION IN THE WARM SECTOR...HIGHS IN THE MID 70S TO MID 80S. && .LONG TERM /SATURDAY THROUGH TUESDAY/... SFC CDFNT TO PUSH OFF THE CST AFT MDNGT FRI NGT...TO BE FOLLOWED BY HI PRES FM THE WNW BUILDING OVR THE RGN THIS WKND. CONTG HI CHC/LIKELY POPS FRI EVE...THEN TAPERING OFF W-E THROUGH LT FRI NGT/EARLY SAT MRNG. XPCG CLRG ON SAT AS DRYING AIR FM THE WNW SPREADS OVR THE RGN. THE HIGH MOVES OFF THE CST BY EARLY NEXT WK...RESULTING IN WNDS BECOMING SSW...AND MOISTURE GRADUALLY INCRSG. LO TEMPS FRI NGT FM THE M50S NW TO ARND 60F SE. HI TEMPS SAT IN THE L/M60S AT THE CST...TO L70S INLAND. LO TEMPS SAT NGT FM THE M40S NW TO L50S SE. HI TEMPS SUN NR 60F AT THE CST...TO 65 TO 70F ELSW. HI TEMPS MON/TUE FM THE M60S TO M70S. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... ALL TAF SITES VFR EARLY THIS EVENING. MOST OF THE RAIN HAS MOVED OFFSHORE OR DISSIPATED. WINDS ARE MOSTLY FROM THE SE-S AND LESS THAN 10KT. A BACKDOOR COLD FRONT IS EXPECTED TO DROP THROUGH THE REGION LATE TONIGHT/WED MORNING. WINDS WILL SHFT TO THE NE OVERNIGHT AND CIGS WILL LOWER TO MVFR/IFR CONDS. KRIC/KORF/KPHF SHOULD SEE FRONTAL PASSAGE IN THE 11Z TO 13Z TIME FRAME...WITH IFR MOVING IN AT OR JUST AFTER FRONTAL PASSAGE. ATTM...NOT EXPECTING A LOT OF RA/SHRA ACTIVITY WITH FRONT...ALTHOUGH SOME LIGHT RAIN/DRIZZLE LIKELY TO OCCUR ANYTIME AFTER 06Z WED. ONCE FRONT MOVES THROUGH...AN 18-30 HOUR PERIOD OF IFR/LOW MVFR CEILINGS LIKELY TO PERSIST BEFORE FRONT LIFTS BACK NORTH AS A WARM FRONT THURSDAY NIGHT/FRIDAY MORNING. COLD FRONT EXPECTED TO MOVE THROUGH FRIDAY AFTERNOON/NIGHT...BRINGING ADDITIONAL SHWR/TSTM ACTIVITY. && .MARINE... SFC LO PRES WILL DEVELOP/MOVE ACRS THE WTRS INVOF BACKDOOR CDFNT THAT DROPS S ACRS THE WTRS TNGT THROUGH WED...SWITCHING WNDS TO THE N-NE. XPCG NNE WINDS TO INCREASE OVER THE WATER VERY LT TNGT/ERY WED FAR NRN OCN WTRS...THEN CONT ELSW DURG WED. SPEEDS OF 10-20 KT OVER THE ERN VA RIVERS/BAY/SOUND AND 15 TO 25 KT OVER THE COASTAL WATERS. SEAS ALSO BUILD TO 5-7 FT NORTH OF CAPE CHARLES LIGHT...3-4 FT SOUTH. ONSHORE FLOW PERSISTS THU WITH SEAS IN THE NRN WATERS HOVERING AROUND 5-6 FT...COULD BE A PD OF NR 5 FT SRN OCN WTRS WED NGT/THU AS WELL. FRONT LIFTS BACK NORTH OF THE WATERS THU NGT-FRI WITH WNDS BECOMING SSW. COLD FRONT CROSSES THE WATERS FRI NIGHT. STRONGEST CAA EXPECTED TO REMAIN N OF THE REGION POST CDFNT (INTO SAT)...SO DO NOT ANTICIPATE SCA CONDITIONS ATTM. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 2 PM EDT THURSDAY FOR ANZ652-654. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ650. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...MAS LONG TERM...ALB AVIATION...JEF/WRS MARINE...ALB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
923 PM EDT THU APR 9 2015 LATEST UPDATE... MESOSCALE DISCUSSION .MESOSCALE DISCUSSION... ISSUED AT 923 PM EDT THU APR 9 2015 WE CONTINUE TO WATCH THE CONVECTION ACROSS WISCONSIN AND ILLINOIS MOVE TOWARD THE AREA BEGINNING JUST A LITTLE LATER THIS EVENING. THESE STORMS HAVE A HISTORY OF PRODUCING SOME DAMAGING TORNADOES ACROSS ILLINOIS. THE STORMS ARE NOW IN THE PROCESS OF CONGEALING INTO MORE OF A SQUALL LINE. WE ARE EXPECTING THAT DAMAGING WINDS WILL BE THE MAIN THREAT WITH THESE STORMS AS THEY MOVE INTO THE LAKESHORE COUNTIES AROUND OR JUST AFTER 10 PM. SOME LARGE HAIL WILL BE POSSIBLE...AND AN ISOLATED TORNADO CAN NOT BE RULED OUT YET. INSTABILITY REMAINS PRESENT ACROSS THE REGION WITH MU CAPES OF OVER 1000 J/KG ACROSS THE SW CORNER OF THE CWFA WITH LESSER AMOUNTS TO THE NE. WE COULD SEE INSTABILITY INCREASE A LITTLE IN THE NEXT COUPLE OF HOURS WITH THE AIR MASS ADVECTING IN FROM THE SW. DEEP LAYER SHEAR IS INCREASING TO OVER 40 KNOTS AS THE WAVE APPROACHES THE AREA. 0-1KM HELICITY IS ON THE INCREASE TO OVER 200 MS/S2 WITH THE APPROACH OF THE SFC LOW...AND COULD INCREASE TO 400 M2/S2. ONE THING THAT WILL NEGATE THE SEVERE THREAT JUST A LITTLE IS A SHALLOW INVERSION WITHIN 1K FT OF THE SFC LIKELY DUE TO THE LOSS OF THE DAYTIME HEATING. THIS IS SHALLOW ENOUGH THAT DAMAGING WINDS/A TORNADO COULD POSSIBLY OVERCOME IT...ESPECIALLY FURTHER SOUTH. && .SYNOPSIS... ISSUED AT 330 PM EDT THU APR 9 2015 STRENGTHENING LOW PRESSURE PASSING JUST WEST OF MICHIGAN WILL BRING THE POTENTIAL FOR SEVERE THUNDERSTORMS THIS EVENING FOLLOWED BY RATHER WINDY CONDITIONS ON FRIDAY. HIGH PRESSURE WILL PROVIDE A PLEASANT WEEKEND. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 330 PM EDT THU APR 9 2015 POTENTIAL FOR DAMAGING THUNDERSTORM WINDS AND PERHAPS EVEN A FEW TORNADOES WILL INCREASE LATER THIS AFTERNOON AND ESPECIALLY THIS EVENING... MAINLY ALONG/SOUTH OF I-96. THE THREAT WILL END SHORTLY AFTER MIDNIGHT. WARM UNSTABLE AIR MASS TO OUR SOUTHWEST IS EXPECTED TO SURGE INTO THE AREA AFTER 5 PM NOW THAT THE POTENT SHORTWAVE OVER KS/NE IS EJECTING NORTHEAST. THIS FEATURE TAKES ON A NEGATIVE TILT AS IT MOVES TOWARD WISCONSIN LATER THIS EVENING... LEADING TO A DEEPENING OF THE SFC LOW AS IT MOVES TOWARD THE MILWAUKEE AREA. THIS SYNOPTIC SET UP WITH A STRONG WARM FRONT/TRIPLE POINT EXTENDING EAST OF THE DEEPENING SFC LOW LEADS TO STRONG CONCERNS FOR ROTATING CELLS AND SPIN UPS NEAR THE WARM FRONT THIS EVENING AS IT MOVES INTO SWRN LWR MI... DUE TO HIGH LOW LEVEL SHEAR VALUES AND POTENTIALLY AVAILABLE UPDRAFT HELICITY. TORNADO WATCHES ARE ALREADY IN EFFECT JUST UPSTREAM OF SW LWR MI AND THE LATEST WATCH... 41... HAS A MEAN STORM MOTION VECTOR OF 240 DEGREES AT 40 KTS. IT SEEMS REASONABLE AT THIS POINT TO BELIEVE WE WILL SEE SFC BASED CAPES OF 1000-1500 J/KG ARRIVING FROM THE SOUTHWEST TOWARD 00Z BASED ON LATEST RUC GUIDANCE AND MESOANALYSIS TO OUR SW. THE OTHER CONCERN THIS EVENING IS FOR LINES/BOWS TO DEVELOP IN THE UPSTREAM TORNADO WATCH AREAS AND RACE RAPIDLY EAST/NORTHEAST ACROSS PARTS OF SW MI. THESE FEATURES COULD PRODUCE DAMAGING STRAIGHT LINE WIND GUSTS AHEAD OF THE COLD FRONT. ALTHOUGH ANY STRONG/SEVERE CONVECTION WILL END AFTER MIDNIGHT WITH THE PASSAGE OF THE SFC COLD FRONT... STRONG SYNOPTIC WIND GUSTS BEHIND THE FRONT DUE TO CONTINUED DEEPENING OF THE SFC LOW OVR NRN LWR MI WILL LEAD TO SOME GUSTS TO 50 MPH OVERNIGHT INTO FRIDAY. CONVECTIVE SHOWERS WITH HIGH CLOUD BASES UNDER THE UPPER LOW ON FRIDAY COULD HELP PROMOTE STRONG GUSTS AS WELL. WILL ISSUE A WIND ADVISORY FOR LATE TONIGHT AND FRIDAY. THINGS QUIET DOWN CONSIDERABLY FRIDAY NIGHT AS HIGH PRESSURE BUILDS IN. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 330 PM EDT THU APR 9 2015 WARMER THAN NORMAL WEATHER FOR A CHANGE FROM SUNDAY AT LEAST INTO WEDNESDAY OF NEXT WEEK. STILL A CHANCE OF A WET STRETCH ON WEDNESDAY OR THURSDAY BUT TIMING IS REALLY UNCERTAIN. OVERALL PATTER IS SOMEWHAT PROGRESSIVE WITH GOOD NWP AGREEMENT ON WEST COAST TROF AND EAST COAST RIDGE DEVELOPING EARLY NEXT WEEK. SUCH A PATTERN WILL PROVIDE THE WARMTH WITH POSITIVE H85 TEMPS THROUGHOUT NEXT WEEK. AFTER MID 60S ON SUNDAY A COLD FRONT WILL PUSH THROUGH MONDAY MORNING. THINKING IT WILL LIKELY COOL MONDAY BY JUST A FEW DEGREES OVER SUNDAY AS THE UPSTREAM HIGH IS WEAK AND THERE IS JUST NOT MUCH OF A PUSH OF COLD AIR. THERE WILL BE SOME DECENT MOISTURE ADVECTION ALONG AND AHEAD OF THE FRONT SUNDAY EVENING SO STILL THINKING SCT SHOWERS ARE A GOOD BET WITH THE FRONTAL PASSAGE ITSELF. IN ANY CASE IT SHOULD BE A QUICK HITTER AND AT LEAST THE LATTER HALF OF MONDAY WILL BE DRY AND SEASONABLE. AFTER THAT THERE IS MUCH DISAGREEMENT ON HOW PROGRESSIVE WEST COAST TROF WILL BE AND HOW MUCH AND WHEN WILL A SOUTHERN STREAM SHORTWAVE EJECT NORTHEAST TOWARDS THE MISSISSIPPI VALLEY AND THEN GREAT LAKES. EACH OF THE PAST FEW DAYS THE GFS/ECM HAVE BEEN DELAYING THE SYSTEM BY A DAY...YESTERDAY THE SIGNAL WAS FOR A WEDNESDAY EVENT WHILE TODAY IT IS NOW LOOKING LIKE A THURSDAY EVENT. BASICALLY...THE POTENTIAL HIS SMEARED OUT IN THE FORECAST WITH CHANCE POPS FOR TUE NIGHT INTO THURSDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 803 PM EDT THU APR 9 2015 OTHER THAN SOME MARINE FOG IMPACTING MKG... WE HAVE GONE MOSTLY VFR ACROSS SRN LWR MI WITH THE WARM FRONT NORTH SURGING THROUGH THE AREA. WE ARE CURRENTLY IN A LULL AS FAR AS CONVECTION GOES RIGHT NOW... BUT NUMEROUS TSTMS TO OUR WEST SHOULD ARRIVE 01Z-03Z AND IMPACT THE TERMINALS THROUGH ABOUT 06Z OR SO. WIDESPREAD IFR TO MVFR CIGS SHOULD ARRIVE/FILL IN AFTER THE TSTMS HAVE PASSED AND A FEW RAIN SHOWERS MAY LINGER AS WELL. CIGS ARE EXPECTED TO RETURN TO VFR LEVELS ON FRIDAY AFTERNOON. LOOK FOR WINDS TO INCREASE DRAMATICALLY OUT OF THE SOUTHWEST LATER TONIGHT WITH SOME GUSTS OF 30-40 KTS LIKELY. THESE STRONG WIND GUSTS WILL PERSIST THROUGH ABOUT 18Z FRIDAY FOLLOWED BY A GRADUAL DECREASING TREND. && .MARINE... ISSUED AT 330 PM EDT THU APR 9 2015 WILL UPGRADE THE GALE WATCH TO A WARNING AS WINDS INCREASE DRAMATICALLY OUT OF THE WEST LATER TONIGHT BEHIND THE COLD FRONT. ALSO AREAS OF DENSE FOG WILL IMPACT LK MI UNTIL AROUND OR SHORTLY AFTER MIDNIGHT AS THE DRIER AIR AND STRONG WINDS ARRIVE. && .HYDROLOGY... ISSUED AT 534 PM EDT THU APR 9 2015 2 TO 3 INCHES OF RAIN HAS FALLEN IN THE PAST 15 HOURS IN PORTIONS OF OTTAWA... KENT... AND OCEANA COUNTIES. 1 TO 2 INCHES HAS FALLEN IN MANY LAKESHORE AND CENTRAL MICHIGAN COMMUNITIES... AND A QUARTER INCH TO 1 INCH IN SOUTHERN MICHIGAN. A FEW RIVERS HAVE BEGUN RISING. THE ROGUE BELOW ROCKFORD IS ALREADY ABOVE BANKFULL. SEVERAL OTHER RIVERS ARE FORECAST TO RISE ABOVE OR CLOSE TO BANKFULL. AS SUCH... RIVER FLOOD ADVISORIES HAVE BEEN ISSUED IN ADDITION TO THE AREAL FLOOD ADVISORY. RIVERS WILL BE CLOSELY MONITORED TONIGHT AS MORE RAINFALL IS EXPECTED. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...WIND ADVISORY FROM 2 AM TO 6 PM EDT FRIDAY FOR MIZ037>040- 043>046-050>052-056>059-064>067-071>074. LM...GALE WARNING UNTIL 2 PM EDT FRIDAY FOR LMZ844>849. && $$ MESOSCALE...NJJ SYNOPSIS...MEADE SHORT TERM...MEADE LONG TERM...COBB AVIATION...MEADE HYDROLOGY...CAS MARINE...MEADE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
803 PM EDT THU APR 9 2015 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 330 PM EDT THU APR 9 2015 STRENGTHENING LOW PRESSURE PASSING JUST WEST OF MICHIGAN WILL BRING THE POTENTIAL FOR SEVERE THUNDERSTORMS THIS EVENING FOLLOWED BY RATHER WINDY CONDITIONS ON FRIDAY. HIGH PRESSURE WILL PROVIDE A PLEASANT WEEKEND. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 330 PM EDT THU APR 9 2015 POTENTIAL FOR DAMAGING THUNDERSTORM WINDS AND PERHAPS EVEN A FEW TORNADOES WILL INCREASE LATER THIS AFTERNOON AND ESPECIALLY THIS EVENING... MAINLY ALONG/SOUTH OF I-96. THE THREAT WILL END SHORTLY AFTER MIDNIGHT. WARM UNSTABLE AIR MASS TO OUR SOUTHWEST IS EXPECTED TO SURGE INTO THE AREA AFTER 5 PM NOW THAT THE POTENT SHORTWAVE OVER KS/NE IS EJECTING NORTHEAST. THIS FEATURE TAKES ON A NEGATIVE TILT AS IT MOVES TOWARD WISCONSIN LATER THIS EVENING... LEADING TO A DEEPENING OF THE SFC LOW AS IT MOVES TOWARD THE MILWAUKEE AREA. THIS SYNOPTIC SET UP WITH A STRONG WARM FRONT/TRIPLE POINT EXTENDING EAST OF THE DEEPENING SFC LOW LEADS TO STRONG CONCERNS FOR ROTATING CELLS AND SPIN UPS NEAR THE WARM FRONT THIS EVENING AS IT MOVES INTO SWRN LWR MI... DUE TO HIGH LOW LEVEL SHEAR VALUES AND POTENTIALLY AVAILABLE UPDRAFT HELICITY. TORNADO WATCHES ARE ALREADY IN EFFECT JUST UPSTREAM OF SW LWR MI AND THE LATEST WATCH... 41... HAS A MEAN STORM MOTION VECTOR OF 240 DEGREES AT 40 KTS. IT SEEMS REASONABLE AT THIS POINT TO BELIEVE WE WILL SEE SFC BASED CAPES OF 1000-1500 J/KG ARRIVING FROM THE SOUTHWEST TOWARD 00Z BASED ON LATEST RUC GUIDANCE AND MESOANALYSIS TO OUR SW. THE OTHER CONCERN THIS EVENING IS FOR LINES/BOWS TO DEVELOP IN THE UPSTREAM TORNADO WATCH AREAS AND RACE RAPIDLY EAST/NORTHEAST ACROSS PARTS OF SW MI. THESE FEATURES COULD PRODUCE DAMAGING STRAIGHT LINE WIND GUSTS AHEAD OF THE COLD FRONT. ALTHOUGH ANY STRONG/SEVERE CONVECTION WILL END AFTER MIDNIGHT WITH THE PASSAGE OF THE SFC COLD FRONT... STRONG SYNOPTIC WIND GUSTS BEHIND THE FRONT DUE TO CONTINUED DEEPENING OF THE SFC LOW OVR NRN LWR MI WILL LEAD TO SOME GUSTS TO 50 MPH OVERNIGHT INTO FRIDAY. CONVECTIVE SHOWERS WITH HIGH CLOUD BASES UNDER THE UPPER LOW ON FRIDAY COULD HELP PROMOTE STRONG GUSTS AS WELL. WILL ISSUE A WIND ADVISORY FOR LATE TONIGHT AND FRIDAY. THINGS QUIET DOWN CONSIDERABLY FRIDAY NIGHT AS HIGH PRESSURE BUILDS IN. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 330 PM EDT THU APR 9 2015 WARMER THAN NORMAL WEATHER FOR A CHANGE FROM SUNDAY AT LEAST INTO WEDNESDAY OF NEXT WEEK. STILL A CHANCE OF A WET STRETCH ON WEDNESDAY OR THURSDAY BUT TIMING IS REALLY UNCERTAIN. OVERALL PATTER IS SOMEWHAT PROGRESSIVE WITH GOOD NWP AGREEMENT ON WEST COAST TROF AND EAST COAST RIDGE DEVELOPING EARLY NEXT WEEK. SUCH A PATTERN WILL PROVIDE THE WARMTH WITH POSITIVE H85 TEMPS THROUGHOUT NEXT WEEK. AFTER MID 60S ON SUNDAY A COLD FRONT WILL PUSH THROUGH MONDAY MORNING. THINKING IT WILL LIKELY COOL MONDAY BY JUST A FEW DEGREES OVER SUNDAY AS THE UPSTREAM HIGH IS WEAK AND THERE IS JUST NOT MUCH OF A PUSH OF COLD AIR. THERE WILL BE SOME DECENT MOISTURE ADVECTION ALONG AND AHEAD OF THE FRONT SUNDAY EVENING SO STILL THINKING SCT SHOWERS ARE A GOOD BET WITH THE FRONTAL PASSAGE ITSELF. IN ANY CASE IT SHOULD BE A QUICK HITTER AND AT LEAST THE LATTER HALF OF MONDAY WILL BE DRY AND SEASONABLE. AFTER THAT THERE IS MUCH DISAGREEMENT ON HOW PROGRESSIVE WEST COAST TROF WILL BE AND HOW MUCH AND WHEN WILL A SOUTHERN STREAM SHORTWAVE EJECT NORTHEAST TOWARDS THE MISSISSIPPI VALLEY AND THEN GREAT LAKES. EACH OF THE PAST FEW DAYS THE GFS/ECM HAVE BEEN DELAYING THE SYSTEM BY A DAY...YESTERDAY THE SIGNAL WAS FOR A WEDNESDAY EVENT WHILE TODAY IT IS NOW LOOKING LIKE A THURSDAY EVENT. BASICALLY...THE POTENTIAL HIS SMEARED OUT IN THE FORECAST WITH CHANCE POPS FOR TUE NIGHT INTO THURSDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 803 PM EDT THU APR 9 2015 OTHER THAN SOME MARINE FOG IMPACTING MKG... WE HAVE GONE MOSTLY VFR ACROSS SRN LWR MI WITH THE WARM FRONT NORTH SURGING THROUGH THE AREA. WE ARE CURRENTLY IN A LULL AS FAR AS CONVECTION GOES RIGHT NOW... BUT NUMEROUS TSTMS TO OUR WEST SHOULD ARRIVE 01Z-03Z AND IMPACT THE TERMINALS THROUGH ABOUT 06Z OR SO. WIDESPREAD IFR TO MVFR CIGS SHOULD ARRIVE/FILL IN AFTER THE TSTMS HAVE PASSED AND A FEW RAIN SHOWERS MAY LINGER AS WELL. CIGS ARE EXPECTED TO RETURN TO VFR LEVELS ON FRIDAY AFTERNOON. LOOK FOR WINDS TO INCREASE DRAMATICALLY OUT OF THE SOUTHWEST LATER TONIGHT WITH SOME GUSTS OF 30-40 KTS LIKELY. THESE STRONG WIND GUSTS WILL PERSIST THROUGH ABOUT 18Z FRIDAY FOLLOWED BY A GRADUAL DECREASING TREND. && .MARINE... ISSUED AT 330 PM EDT THU APR 9 2015 WILL UPGRADE THE GALE WATCH TO A WARNING AS WINDS INCREASE DRAMATICALLY OUT OF THE WEST LATER TONIGHT BEHIND THE COLD FRONT. ALSO AREAS OF DENSE FOG WILL IMPACT LK MI UNTIL AROUND OR SHORTLY AFTER MIDNIGHT AS THE DRIER AIR AND STRONG WINDS ARRIVE. && .HYDROLOGY... ISSUED AT 534 PM EDT THU APR 9 2015 2 TO 3 INCHES OF RAIN HAS FALLEN IN THE PAST 15 HOURS IN PORTIONS OF OTTAWA... KENT... AND OCEANA COUNTIES. 1 TO 2 INCHES HAS FALLEN IN MANY LAKESHORE AND CENTRAL MICHIGAN COMMUNITIES... AND A QUARTER INCH TO 1 INCH IN SOUTHERN MICHIGAN. A FEW RIVERS HAVE BEGUN RISING. THE ROGUE BELOW ROCKFORD IS ALREADY ABOVE BANKFULL. SEVERAL OTHER RIVERS ARE FORECAST TO RISE ABOVE OR CLOSE TO BANKFULL. AS SUCH... RIVER FLOOD ADVISORIES HAVE BEEN ISSUED IN ADDITION TO THE AREAL FLOOD ADVISORY. RIVERS WILL BE CLOSELY MONITORED TONIGHT AS MORE RAINFALL IS EXPECTED. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...WIND ADVISORY FROM 2 AM TO 6 PM EDT FRIDAY FOR MIZ037>040- 043>046-050>052-056>059-064>067-071>074. LM...GALE WARNING FROM MIDNIGHT TONIGHT TO 2 PM EDT FRIDAY FOR LMZ844>849. && $$ SYNOPSIS...MEADE SHORT TERM...MEADE LONG TERM...COBB AVIATION...MEADE HYDROLOGY...CAS MARINE...MEADE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
656 PM EDT WED APR 8 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 456 PM EDT WED APR 8 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW PAIR OF SHORTWAVES RESPONSIBLE FOR THE LIGHT WINTRY MIX OF PCPN EARLIER TODAY NOW N AND E OF THE FCST AREA. ANOTHER SHORTWAVE MOVING FROM MANITOBA INTO NRN ONTARIO WON`T BE A FACTOR IN THE SHORT TERM WEATHER. FARTHER TO THE NW AND ALSO TO THE SW ARE 2 SHORTWAVES THAT WILL PLAY A ROLE IN WHAT WILL BECOME A QUICK HITTING SIGNIFICANT SPRING SNOWSTORM FOR PORTIONS OF UPPER MI THU NIGHT. ONE WAVE IS DROPPING INTO NRN MANITOBA AND THE SECOND WAVE IS OVER NV/UT. DETAILS ON THE HVY/WET SNOW CAN BE FOUND IN THE LONG TERM PORTION OF THE DISCUSSION BELOW. IN THE WAKE OF THE PCPN EARLIER TODAY...ABUNDANT CLOUD COVER DOMINATES THE UPPER GREAT LAKES...THOUGH NOT ALL OF THE LOW-LEVEL DRY AIR HAS BEEN ERODED...AND THERE IS STILL A FEED OF DRIER AIR AT THE LOW LEVELS FROM THE E. THIS HAS RESULTED IN SOME BREAKS DEVELOPING IN THE CLOUD COVER OVER UPPER MI IN THE LAST FEW HRS. WHERE SOME SUN HAS APPEARED...TEMPS HAVE RISEN INTO THE MID AND UPPER 40S. SHORTWAVE OVER NV/UT WILL SHIFT E AND RESULT IN SFC LOW PRES DEVELOPING OVER KS TONIGHT. FARTHER DOWNSTREAM...WATER VAPOR IMAGERY SUGGESTS MORE SUBTLE SHORTWAVE ENERGY LIFTING OUT OVER THE PLAINS. INCREASING WAA/ISENTROPIC ASCENT REGIME DOWNSTREAM OF THE MAIN SHORTWAVE TROF AND ENHANCED BY THE SUBTLE LEAD ENERGY WILL LEAD TO A AN AREA OF RAIN DEVELOPING AND SPREADING/EXPANDING NE INTO UPPER MI LATE TONIGHT INTO THU MORNING. BASED ON NRN EDGE OF THE POOL OF MUCAPE THAT LIFTS N INTO WI...NOT OUT OF THE QUESTION THAT THERE COULD BE FEW RUMBLES OF THUNDER. WHETHER TEMPS WILL BE BLO FREEZING WHEN PCPN BEGINS IS UNCERTAIN. USING MODEL CONSENSUS DIURNAL TEMP CURVE SUGGESTS THERE WILL BE AREAS WHERE TEMPS MAY BE JUST BLO FREEZING LATE TONIGHT/EARLY THU MORNING. HOWEVER...IF TEMPS DON`T FALL MUCH THIS EVENING...-FZRA POTENTIAL WILL BE DIMINISHED. AT THIS TIME...NOT EXPECTING SUFFICIENT ICE PROBLEMS ON ROADWAYS TO WARRANT ADVY ISSUANCE...BUT WILL CONTINUE TO HIGHLIGHT POTENTIAL OF SOME ICY CONDITIONS ON UNTREATED SURFACES LATE TONIGHT THRU MID MORNING THU. AFTER THE INITIAL SURGE OF WAA/ISENTROPIC ASCENT PCPN THAT SWEEPS NE LATE TONIGHT/THU MORNING...WILL PROBABLY SEE -RA DIMINISH OR BECOME MORE SCATTERED FOR A TIME LATE MORNING THRU MID AFTN OR SO AS WE AWAIT THE MAIN SHORTWAVE/STRONG DYNAMICS THAT WILL LIFT INTO THE UPPER LAKES THU NIGHT. PCPN IS LESS LIKELY TO DIMINISH OVER THE W WHERE 850MB TROF WILL EXTEND NE FROM THE APPROACHING LOW ACROSS WRN UPPER MI/WRN LAKE SUPERIOR. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 456 PM EDT WED APR 8 2015 COMPLEX FORECAST FRONT LOADED IN FIRST PERIOD OF LONG TERM. HIGH IMPACT WEATHER EXPECTED IN FORM OF RAIN CHANGING TO HEAVY SNOW. MAIN FACTORS COMING INTO FOCUS FOR THURSDAY NIGHT WEATHER. FIRST ALOFT...UPPER TROUGH OVER THE INTERIOR WESTERN CONUS THIS MORNING MOVES TO UPPER MISSISSIPPI RIVER VALLEY BY THURSDAY EVENING WHILE SHORTWAVE TROUGH DIGGING OVER NORTHERN SASKATCHEWAN THIS AFTN MOVES TO AXIS FM NORTHERN ONTARIO TO SOUTHERN MANITOBA. MAIN JET STREAK LIFTS OVER NORTHERN ONTARIO INTO QUEBEC ON THURSDAY EVENING WHILE ANOTHER JET WILL BE IN PROCESS OF EXITING TOWARD GREAT LAKES. AS THE PLAINS JET ARRIVES OVER THE GREAT LAKES THURSDAY EVENING...LEAD SHORTWAVE TROUGH IS FORECAST TO BECOME MORE NEGATIVELY TILTED AS IT LIFTS OVER THE UPPER GREAT LAKES. FOR MOST PART...LEAD WAVE DRIVES STRENGTH AND TRACK OF H85-H7 TROUGH AND PRIMARY SFC LOW...WHICH TRACKS FM IOWA AT 00Z FRIDAY TO NORTHERN LK MICHIGAN/NORTHERN LOWER MICHIGAN BY 06Z FRIDAY AND TO EAST OF SAULT STE MARIE BY 12Z FRIDAY. MODELS CONTINUE TO DIFFER ON WESTWARD EXTENT OF SFC LOW WHICH AFFECTS WHERE SWATH OF HEAVY QPF WELL OVER 1 INCH OCCURS ROUGHLY 00Z- 09Z ON FRIDAY. GIVEN VERY STRONG LIFT FM COUPLED JET STRUCTURE AND ENHANCED DIVERGENCE ALOFT AND PERSISTENT STRONG MID-LEVEL FGEN ALONG WITH COPIOUS DEEP MOISTURE THAT SHOULD BE ABLE TO TRANSLATE INTO THE DEEPENING SYSTEM AS MAIN INFLOW FOR TSRA SHOULD STAY FAR ENOUGH SOUTHEAST OF UPR MICHIGAN...TEND TO BELIEVE WETTER IDEAS OFFERED UP BY NAM/GFS SHOWING WELL OVER 1 INCH OF QPF. THOUGH ECMWF REMAINS DRIER...IT HAS SHOWN NOTEABLE TREND TOWARD STRONGER SYSTEM THE LAST DAY...SO THAT IS ENCOURAGING AT LEAST FROM THE FORECAST STANDPOINT. RUNNING WITH THE STRONGER/WETTER IDEA...MAIN STICKING POINT IS HOW QUICK THE RAIN CHANGES TO SNOW ON THURSDAY NIGHT. THE EARLIER THAT SWITCHOVER OCCURS...THE MORE THAT HEAVY QPF WILL GO TOWARD WET HEAVY SNOW ACCUMULATION. NAM SOUNDINGS SHOW WARM LAYER BTWN 900MB-800MB VCNTY OF L`ANSE TO WATERSMEET AT 00Z...THEN TO CRYSTAL FALLS AND MARQUETTE/HARVEY BY 03Z...BEFORE PUSHING THIS ON THE MUNISING AND ESCANABA BY 06Z. GFS AND GEM-REGIONAL ARE FARTHER WEST WITH WARM LAYER ALOFT...THOUGH THEY BOTH TRENDED A BIT EAST WITH TRACK OF SFC LOW ON THE 12Z RUNS. EXPECT HEAVY WET SNOW TO IMPACT PARTS OF WESTERN HALF OF UPR MICHIGAN. RETREATING WARM LAYER TO START COULD ALSO RESULT IN SLEET OF FZRA BEFORE CHANGE TO SNOW OCCURS. DECIDED TO ISSUE A WINTER STORM WATCH FOR WESTERN UPR MICHIGAN AS THERE SHOULD BE A NARROW STRIPE OF POSSIBLE VERY HEAVY WET SNOW THURSDAY NIGHT. GIVEN THE FORCING AND MOISTURE...LOCALIZED AMOUNTS OVER 8 INCHES SEEM POSSIBLE. MAIN QUANDARY WAS HOW FAR WEST AND EAST TO PUSH THE WATCH. LEANED A BIT TOWARD THE FARTHER EAST WARM LAYER IDEA WHICH RESULTED IN BRINGING THE WATCH AS FAR EAST AS MARQUETTE COUNTY. GIVEN DECENT CHANCE THAT PRECIP STAYS MAINLY RAIN WELL INTO THE EVENING FOR DICKINSON COUNTY LEFT THEM OUT FOR NOW...THOUGH COULD SEE NEED FOR ADVY FOR EVENTUALLY SLOPPY INCH OR TWO OF SNOW. CORRIDER OF HEAVY SNOW LIKELY WILL NOT MAKE IT AS FAR WEST AS IWD THOUGH LATEST HPC/WWD GRAPHICS STILL HIT FAR WEST FOR DECENT AMOUNT OF SNOW...BUT SINCE EASTERN PORTIONS OF GOGEBIC COUNTY INTO ONTONAGON COUNTY WOULD BE IMPACTED BY THE HEAVY SNOW WITH LATEST THINKING...INCLUDED GOGEBIC AS WELL. ESSENTIALLY SINCE THIS EVENT COULD BE VERY HIGH IMPACT DECIDED TO GO THIS ROUTE INSTEAD OF HAVING AN SPS OUT ONLY. WILL TRY TO CONVEY THE UNCERTAINTY DUE TO BOTH LOCATION OF HEAVIER SNOW AND PTYPE IN THE WSW STATEMENT. COORD WITH DLH AND GRB ON SNOW AMOUNTS/HEADLINE TIMING. LOW PRESSURE EXITS OVER EASTERN CANADA FRIDAY INTO FRIDAY NIGHT. LINGERING LOW-LEVEL MOISTURE/THERMAL TROUGHING AND ADDITIONAL FORCING FM THE NORTHERN STREAM WAVE DROPPING OVER THE AREA SUPPORTS CHANCE POPS FOR SNOW ON FRIDAY THOUGH MOST OF THE BIGGER SNOW WILL BE DONE BY DAYBREAK FRIDAY. KEPT WITH TEMPS MAINLY IN THE 30S ON FRIDAY. BREEZY CONDITIONS TOO...ESPECIALLY NEAR LK SUPERIOR IN THE MORNING HOURS. SFC RIDGE CROSSES FRIDAY NIGHT AND TEMPS COULD DIP INTO THE TEENS. EXPECT THIS TO BE THE LAST NIGHT THROUGH THE LONG TERM WHERE TEMPS DROP BLO FREEZING. TEMPS THIS WEEKEND LOOKS WARMER...MUCH WARMER. HIGH CLOUDS INCREASE LATE SATURDAY AND SATURDAY NIGHT AHEAD OF LOW PRESSURE TROUGH THAT MOVES FM SCNTRL CANADA TO NORTHERN PLAINS ON SUNDAY. MIXING HEIGHTS UP TO H85 WITH SW WINDS SUPPORT READINGS WELL INTO THE 50S. COOLEST TEMPS OVER EAST CWA WITH FLOW COMING OFF LK MICHIGAN. SOME LGT RAIN MAY DEVELOP AHEAD OF THE TROUGH ON SUNDAY AS GFS/ECMWF HAVE BEEN SHOWING FOR A WHILE NOW. EVEN SO...WARMER TEMPS ALOFT AND WARMER MIN TEMPS ON SATURDAY NIGHT ALLOW MANY AREAS TO REACH 60 DEGREES. SO ANY SNOW THAT DOES OCCUR THURSDAY NIGHT INTO FRIDAY SHOULD QUICKLY MELT THIS WEEKEND. FURTHER...ONCE THE TEMPS RISE ABOVE FREEZING ON SATURDAY THEY SHOULD REMAIN ABOVE FREEZING THROUGH MUCH OF NEXT WEEK SO WE SHOULD ALSO BEGIN TO MELT GOOD PORTION OF THE SNOWPACK THAT REMAINS OVER MAINLY NORTHERN UPPER MICHIGAN. SHOULD SEE AREA RIVERS AND STREAMS BEGIN TO RESPOND WITH THE SNOWMELT AND RUNOFF. ADDITIONAL RAINFALL POSSIBLE TUESDAY INTO WEDNESDAY AS A LOW PRESSURE SYSTEM AND WARM FRONT MOVE TOWARD THE NORTHERN PLAINS AND UPPER GREAT LAKES. ANY RAINFALL FM THIS SYSTEM WOULD ONLY ADD TO THE RUNOFF. SEEMS THAT AFTER THIS WINTRY SYSTEM WE MIGHT JUST SHIFT INTO THE MAIN SNOWMELT HYDROLOGY PERIOD OF THE SPRING. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 656 PM EDT WED APR 8 2015 GUIDANCE IS STRONGLY POINTING TOWARD DETERIORATING CONDITIONS THIS EVENING AND WILL GO WITH THIS TREND AT ALL SITES. AS MOISTURE AND PCPN SPREAD N LATE TONIGHT/EARLY THU...EXPECT CONDITIONS TO FALL TO IFR AT ALL TERMINALS. PCPN MAY BEGIN AS -FZRA FOR 2-3HRS AT KCMX/KSAW...BUT WILL CHANGE TO -RA AS TEMPS RISE DURING THE MORNING. KSAW IS LIKELY TO FALL TO LIFR BY MID MORNING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 456 PM EDT WED APR 8 2015 HIGH PRES MOVING E ACROSS QUEBEC AND LOW PRES DEVELOPING OVER THE CNTRL/SRN PLAINS WILL KEEP LAKE SUPERIOR UNDER GENERAL E TO NE WINDS OF 10-20KT THRU EARLY THU AFTN. AS THE LOW PRES TRACKS NE ACROSS NORTHERN LAKE MI THU EVENING AND INTO ONTARIO FRI MORNING...WINDS WILL BACK TO THE NW. OVER THE CNTRL PART OF LAKE SUPERIOR...THE WIND WILL ALSO INCREASE TO 20-30KT...AND OVER ERN LAKE SUPERIOR N TO NW GALES WILL DEVELOP BY FRI MORNING. WINDS WILL THEN DIMINISH W TO E FRI AFTN THRU FRI NIGHT AS HIGH PRES BUILDS ACROSS THE MISSISSIPPI VALLEY. LIGHT WINDS UNDER 20KT ARE EXPECTED SAT AS THE HIGH PRES RIDGE PASSES ACROSS THE WRN GREAT LAKES. AS THE RIDGE SHIFTS E AND A LOW PRES TROF MOVES E ACROSS THE NRN PLAINS...WINDS WILL THEN INCREASE SAT NIGHT/SUN...PROBABLY REACHING 15-25KT OR MORE OVER AT LEAST THE E HALF OF LAKE SUPERIOR ON SUN. THE TROF WILL CROSS THE UPPER GREAT LAKES SUN NIGHT...BRINGING A WIND SHIFT TO THE W. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER STORM WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR MIZ001>005-009-010-084. LAKE SUPERIOR... GALE WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON FOR LSZ266-267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...07 MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
456 PM EDT WED APR 8 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 456 PM EDT WED APR 8 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW PAIR OF SHORTWAVES RESPONSIBLE FOR THE LIGHT WINTRY MIX OF PCPN EARLIER TODAY NOW N AND E OF THE FCST AREA. ANOTHER SHORTWAVE MOVING FROM MANITOBA INTO NRN ONTARIO WON`T BE A FACTOR IN THE SHORT TERM WEATHER. FARTHER TO THE NW AND ALSO TO THE SW ARE 2 SHORTWAVES THAT WILL PLAY A ROLE IN WHAT WILL BECOME A QUICK HITTING SIGNIFICANT SPRING SNOWSTORM FOR PORTIONS OF UPPER MI THU NIGHT. ONE WAVE IS DROPPING INTO NRN MANITOBA AND THE SECOND WAVE IS OVER NV/UT. DETAILS ON THE HVY/WET SNOW CAN BE FOUND IN THE LONG TERM PORTION OF THE DISCUSSION BELOW. IN THE WAKE OF THE PCPN EARLIER TODAY...ABUNDANT CLOUD COVER DOMINATES THE UPPER GREAT LAKES...THOUGH NOT ALL OF THE LOW-LEVEL DRY AIR HAS BEEN ERODED...AND THERE IS STILL A FEED OF DRIER AIR AT THE LOW LEVELS FROM THE E. THIS HAS RESULTED IN SOME BREAKS DEVELOPING IN THE CLOUD COVER OVER UPPER MI IN THE LAST FEW HRS. WHERE SOME SUN HAS APPEARED...TEMPS HAVE RISEN INTO THE MID AND UPPER 40S. SHORTWAVE OVER NV/UT WILL SHIFT E AND RESULT IN SFC LOW PRES DEVELOPING OVER KS TONIGHT. FARTHER DOWNSTREAM...WATER VAPOR IMAGERY SUGGESTS MORE SUBTLE SHORTWAVE ENERGY LIFTING OUT OVER THE PLAINS. INCREASING WAA/ISENTROPIC ASCENT REGIME DOWNSTREAM OF THE MAIN SHORTWAVE TROF AND ENHANCED BY THE SUBTLE LEAD ENERGY WILL LEAD TO A AN AREA OF RAIN DEVELOPING AND SPREADING/EXPANDING NE INTO UPPER MI LATE TONIGHT INTO THU MORNING. BASED ON NRN EDGE OF THE POOL OF MUCAPE THAT LIFTS N INTO WI...NOT OUT OF THE QUESTION THAT THERE COULD BE FEW RUMBLES OF THUNDER. WHETHER TEMPS WILL BE BLO FREEZING WHEN PCPN BEGINS IS UNCERTAIN. USING MODEL CONSENSUS DIURNAL TEMP CURVE SUGGESTS THERE WILL BE AREAS WHERE TEMPS MAY BE JUST BLO FREEZING LATE TONIGHT/EARLY THU MORNING. HOWEVER...IF TEMPS DON`T FALL MUCH THIS EVENING...-FZRA POTENTIAL WILL BE DIMINISHED. AT THIS TIME...NOT EXPECTING SUFFICIENT ICE PROBLEMS ON ROADWAYS TO WARRANT ADVY ISSUANCE...BUT WILL CONTINUE TO HIGHLIGHT POTENTIAL OF SOME ICY CONDITIONS ON UNTREATED SURFACES LATE TONIGHT THRU MID MORNING THU. AFTER THE INITIAL SURGE OF WAA/ISENTROPIC ASCENT PCPN THAT SWEEPS NE LATE TONIGHT/THU MORNING...WILL PROBABLY SEE -RA DIMINISH OR BECOME MORE SCATTERED FOR A TIME LATE MORNING THRU MID AFTN OR SO AS WE AWAIT THE MAIN SHORTWAVE/STRONG DYNAMICS THAT WILL LIFT INTO THE UPPER LAKES THU NIGHT. PCPN IS LESS LIKELY TO DIMINISH OVER THE W WHERE 850MB TROF WILL EXTEND NE FROM THE APPROACHING LOW ACROSS WRN UPPER MI/WRN LAKE SUPERIOR. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 456 PM EDT WED APR 8 2015 COMPLEX FORECAST FRONT LOADED IN FIRST PERIOD OF LONG TERM. HIGH IMPACT WEATHER EXPECTED IN FORM OF RAIN CHANGING TO HEAVY SNOW. MAIN FACTORS COMING INTO FOCUS FOR THURSDAY NIGHT WEATHER. FIRST ALOFT...UPPER TROUGH OVER THE INTERIOR WESTERN CONUS THIS MORNING MOVES TO UPPER MISSISSIPPI RIVER VALLEY BY THURSDAY EVENING WHILE SHORTWAVE TROUGH DIGGING OVER NORTHERN SASKATCHEWAN THIS AFTN MOVES TO AXIS FM NORTHERN ONTARIO TO SOUTHERN MANITOBA. MAIN JET STREAK LIFTS OVER NORTHERN ONTARIO INTO QUEBEC ON THURSDAY EVENING WHILE ANOTHER JET WILL BE IN PROCESS OF EXITING TOWARD GREAT LAKES. AS THE PLAINS JET ARRIVES OVER THE GREAT LAKES THURSDAY EVENING...LEAD SHORTWAVE TROUGH IS FORECAST TO BECOME MORE NEGATIVELY TILTED AS IT LIFTS OVER THE UPPER GREAT LAKES. FOR MOST PART...LEAD WAVE DRIVES STRENGTH AND TRACK OF H85-H7 TROUGH AND PRIMARY SFC LOW...WHICH TRACKS FM IOWA AT 00Z FRIDAY TO NORTHERN LK MICHIGAN/NORTHERN LOWER MICHIGAN BY 06Z FRIDAY AND TO EAST OF SAULT STE MARIE BY 12Z FRIDAY. MODELS CONTINUE TO DIFFER ON WESTWARD EXTENT OF SFC LOW WHICH AFFECTS WHERE SWATH OF HEAVY QPF WELL OVER 1 INCH OCCURS ROUGHLY 00Z- 09Z ON FRIDAY. GIVEN VERY STRONG LIFT FM COUPLED JET STRUCTURE AND ENHANCED DIVERGENCE ALOFT AND PERSISTENT STRONG MID-LEVEL FGEN ALONG WITH COPIOUS DEEP MOISTURE THAT SHOULD BE ABLE TO TRANSLATE INTO THE DEEPENING SYSTEM AS MAIN INFLOW FOR TSRA SHOULD STAY FAR ENOUGH SOUTHEAST OF UPR MICHIGAN...TEND TO BELIEVE WETTER IDEAS OFFERED UP BY NAM/GFS SHOWING WELL OVER 1 INCH OF QPF. THOUGH ECMWF REMAINS DRIER...IT HAS SHOWN NOTEABLE TREND TOWARD STRONGER SYSTEM THE LAST DAY...SO THAT IS ENCOURAGING AT LEAST FROM THE FORECAST STANDPOINT. RUNNING WITH THE STRONGER/WETTER IDEA...MAIN STICKING POINT IS HOW QUICK THE RAIN CHANGES TO SNOW ON THURSDAY NIGHT. THE EARLIER THAT SWITCHOVER OCCURS...THE MORE THAT HEAVY QPF WILL GO TOWARD WET HEAVY SNOW ACCUMULATION. NAM SOUNDINGS SHOW WARM LAYER BTWN 900MB-800MB VCNTY OF L`ANSE TO WATERSMEET AT 00Z...THEN TO CRYSTAL FALLS AND MARQUETTE/HARVEY BY 03Z...BEFORE PUSHING THIS ON THE MUNISING AND ESCANABA BY 06Z. GFS AND GEM-REGIONAL ARE FARTHER WEST WITH WARM LAYER ALOFT...THOUGH THEY BOTH TRENDED A BIT EAST WITH TRACK OF SFC LOW ON THE 12Z RUNS. EXPECT HEAVY WET SNOW TO IMPACT PARTS OF WESTERN HALF OF UPR MICHIGAN. RETREATING WARM LAYER TO START COULD ALSO RESULT IN SLEET OF FZRA BEFORE CHANGE TO SNOW OCCURS. DECIDED TO ISSUE A WINTER STORM WATCH FOR WESTERN UPR MICHIGAN AS THERE SHOULD BE A NARROW STRIPE OF POSSIBLE VERY HEAVY WET SNOW THURSDAY NIGHT. GIVEN THE FORCING AND MOISTURE...LOCALIZED AMOUNTS OVER 8 INCHES SEEM POSSIBLE. MAIN QUANDARY WAS HOW FAR WEST AND EAST TO PUSH THE WATCH. LEANED A BIT TOWARD THE FARTHER EAST WARM LAYER IDEA WHICH RESULTED IN BRINGING THE WATCH AS FAR EAST AS MARQUETTE COUNTY. GIVEN DECENT CHANCE THAT PRECIP STAYS MAINLY RAIN WELL INTO THE EVENING FOR DICKINSON COUNTY LEFT THEM OUT FOR NOW...THOUGH COULD SEE NEED FOR ADVY FOR EVENTUALLY SLOPPY INCH OR TWO OF SNOW. CORRIDER OF HEAVY SNOW LIKELY WILL NOT MAKE IT AS FAR WEST AS IWD THOUGH LATEST HPC/WWD GRAPHICS STILL HIT FAR WEST FOR DECENT AMOUNT OF SNOW...BUT SINCE EASTERN PORTIONS OF GOGEBIC COUNTY INTO ONTONAGON COUNTY WOULD BE IMPACTED BY THE HEAVY SNOW WITH LATEST THINKING...INCLUDED GOGEBIC AS WELL. ESSENTIALLY SINCE THIS EVENT COULD BE VERY HIGH IMPACT DECIDED TO GO THIS ROUTE INSTEAD OF HAVING AN SPS OUT ONLY. WILL TRY TO CONVEY THE UNCERTAINTY DUE TO BOTH LOCATION OF HEAVIER SNOW AND PTYPE IN THE WSW STATEMENT. COORD WITH DLH AND GRB ON SNOW AMOUNTS/HEADLINE TIMING. LOW PRESSURE EXITS OVER EASTERN CANADA FRIDAY INTO FRIDAY NIGHT. LINGERING LOW-LEVEL MOISTURE/THERMAL TROUGHING AND ADDITIONAL FORCING FM THE NORTHERN STREAM WAVE DROPPING OVER THE AREA SUPPORTS CHANCE POPS FOR SNOW ON FRIDAY THOUGH MOST OF THE BIGGER SNOW WILL BE DONE BY DAYBREAK FRIDAY. KEPT WITH TEMPS MAINLY IN THE 30S ON FRIDAY. BREEZY CONDITIONS TOO...ESPECIALLY NEAR LK SUPERIOR IN THE MORNING HOURS. SFC RIDGE CROSSES FRIDAY NIGHT AND TEMPS COULD DIP INTO THE TEENS. EXPECT THIS TO BE THE LAST NIGHT THROUGH THE LONG TERM WHERE TEMPS DROP BLO FREEZING. TEMPS THIS WEEKEND LOOKS WARMER...MUCH WARMER. HIGH CLOUDS INCREASE LATE SATURDAY AND SATURDAY NIGHT AHEAD OF LOW PRESSURE TROUGH THAT MOVES FM SCNTRL CANADA TO NORTHERN PLAINS ON SUNDAY. MIXING HEIGHTS UP TO H85 WITH SW WINDS SUPPORT READINGS WELL INTO THE 50S. COOLEST TEMPS OVER EAST CWA WITH FLOW COMING OFF LK MICHIGAN. SOME LGT RAIN MAY DEVELOP AHEAD OF THE TROUGH ON SUNDAY AS GFS/ECMWF HAVE BEEN SHOWING FOR A WHILE NOW. EVEN SO...WARMER TEMPS ALOFT AND WARMER MIN TEMPS ON SATURDAY NIGHT ALLOW MANY AREAS TO REACH 60 DEGREES. SO ANY SNOW THAT DOES OCCUR THURSDAY NIGHT INTO FRIDAY SHOULD QUICKLY MELT THIS WEEKEND. FURTHER...ONCE THE TEMPS RISE ABOVE FREEZING ON SATURDAY THEY SHOULD REMAIN ABOVE FREEZING THROUGH MUCH OF NEXT WEEK SO WE SHOULD ALSO BEGIN TO MELT GOOD PORTION OF THE SNOWPACK THAT REMAINS OVER MAINLY NORTHERN UPPER MICHIGAN. SHOULD SEE AREA RIVERS AND STREAMS BEGIN TO RESPOND WITH THE SNOWMELT AND RUNOFF. ADDITIONAL RAINFALL POSSIBLE TUESDAY INTO WEDNESDAY AS A LOW PRESSURE SYSTEM AND WARM FRONT MOVE TOWARD THE NORTHERN PLAINS AND UPPER GREAT LAKES. ANY RAINFALL FM THIS SYSTEM WOULD ONLY ADD TO THE RUNOFF. SEEMS THAT AFTER THIS WINTRY SYSTEM WE MIGHT JUST SHIFT INTO THE MAIN SNOWMELT HYDROLOGY PERIOD OF THE SPRING. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 139 PM EDT WED APR 8 2015 MVFR CONDITIONS SHOULD BE THE RULE AT KIWD/KCMX/KSAW INTO THIS EVENING. HOWEVER...WITH A FEED OF DRY AIR FROM THE E BASED ON SFC OBS...TERMINALS MAY IMPROVE TO VFR AT SOME POINT THIS AFTN. BEING CLOSER TO THE DRIER AIR...KSAW HAS THE BEST OPPORTUNITY OF VFR. GUIDANCE IS STRONGLY POINTING TOWARD DETERIORATING CONDITIONS THIS EVENING...BUT BELIEVE DRY AIR MAY CONTINUE TO HAVE AN INFLUENCE UNDER AN E TO ESE FLOW. THUS...IF VFR CONDITIONS DEVELOP THIS AFTN...VFR MAY LINGER THRU THE EVENING. AS MOISTURE AND PCPN SPREAD N LATE TONIGHT/EARLY THU...EXPECT CONDITIONS TO FALL TO IFR AT ALL TERMINALS. PCPN MAY BEGIN AS -FZRA FOR 2-3HRS AT KCMX/KSAW...BUT WILL CHANGE TO -RA AS TEMPS RISE DURING THE MORNING. KSAW IS LIKELY TO FALL TO LIFR BY MID MORNING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 456 PM EDT WED APR 8 2015 HIGH PRES MOVING E ACROSS QUEBEC AND LOW PRES DEVELOPING OVER THE CNTRL/SRN PLAINS WILL KEEP LAKE SUPERIOR UNDER GENERAL E TO NE WINDS OF 10-20KT THRU EARLY THU AFTN. AS THE LOW PRES TRACKS NE ACROSS NORTHERN LAKE MI THU EVENING AND INTO ONTARIO FRI MORNING...WINDS WILL BACK TO THE NW. OVER THE CNTRL PART OF LAKE SUPERIOR...THE WIND WILL ALSO INCREASE TO 20-30KT...AND OVER ERN LAKE SUPERIOR N TO NW GALES WILL DEVELOP BY FRI MORNING. WINDS WILL THEN DIMINISH W TO E FRI AFTN THRU FRI NIGHT AS HIGH PRES BUILDS ACROSS THE MISSISSIPPI VALLEY. LIGHT WINDS UNDER 20KT ARE EXPECTED SAT AS THE HIGH PRES RIDGE PASSES ACROSS THE WRN GREAT LAKES. AS THE RIDGE SHIFTS E AND A LOW PRES TROF MOVES E ACROSS THE NRN PLAINS...WINDS WILL THEN INCREASE SAT NIGHT/SUN...PROBABLY REACHING 15-25KT OR MORE OVER AT LEAST THE E HALF OF LAKE SUPERIOR ON SUN. THE TROF WILL CROSS THE UPPER GREAT LAKES SUN NIGHT...BRINGING A WIND SHIFT TO THE W. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER STORM WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR MIZ001>005-009-010-084. LAKE SUPERIOR... GALE WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON FOR LSZ266-267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
436 AM EDT WED APR 8 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 448 PM EDT TUE APR 7 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THAT THE CONFLUENT FLOW THAT HAS BEEN ACROSS THE UPPER GREAT LAKES IS SHIFTING E AND NE AS THE NRN STREAM TROF OVER ERN CANADA IS SLOWLY LIFTING OUT AND SRN BRANCH RIDGE OVER THE PLAINS DOWNSTREAM OF TROF ALONG THE W COAST IS GRADUALLY BUILDING NE AND E. SFC HIGH PRES SUPPORTED BY THE CONFLUENT FLOW ALOFT RIDGES W-E ACROSS NRN ONTARIO INTO SRN QUEBEC. ALTHOUGH THERE HAVE BEEN SOME MID-LEVEL RADAR RETURNS ACROSS THE FCST AREA...ESPECIALLY EARLIER TODAY...THE VERY DRY AIR AT THE LOWER LEVELS EMANATING FROM THE HIGH PRES RIDGE HAS RESULTED IN DRY WEATHER ACROSS THE FCST AREA TODAY. IN FACT...THE KEWEENAW AND ERN UPPER MI HAVE ENJOYED MOSTLY SUNNY SKIES FOR A GOOD PART OF THE DAY. TO THE S...WARM FRONT/STATIONARY FRONT EXTENDS FROM KS ACROSS CNTRL IL INTO NRN OHIO. TO THE W AND SW...A WELL-DEFINED SHORTWAVE IS TRACKING ENE ACROSS SE SASKATCHEWAN WHILE WEAKER WAVES ARE MOVING ACROSS WY/CO AND OUT ACROSS THE PLAINS. THESE FEATURES WILL PLAY A ROLE IN A CHALLENGING FCST HERE TONIGHT/WED. INITIALLY...EXPECT DRY WEATHER TO PREVAIL THIS EVENING UNDER A CONTINUED FEED OF DRY LOW-LEVEL AIR FROM THE E AND NE. SFC DWPTS AS OF 19Z WERE STILL MOSTLY IN THE 5-10F RANGE ALONG THE MI/WI BORDER...INDICATING THE DRYNESS THAT IS STILL AT THE SFC...AND LATEST RAP FCST SOUNDINGS SHOW THE DRY AIR IN THE LOWER LEVELS HANGING ON DURING THE EVENING. LATER TONIGHT INTO WED...FOCUS SHIFTS TO THE AFORMENTIONED SHORTWAVES. THE STRONGER NRN WAVE WILL REACH NRN ONTARIO EARLY WED MORNING WHILE THE WEAKER SRN WAVES WILL TRACK INTO THE UPPER LAKES. TRACK OF THE STRONGER NRN WAVE INDICATES ITS MAIN FORCING WILL PASS N OF HERE...AND THAT IS WHAT MODELS SHOW FOR PROGRESSION OF DEEP LAYER QVECTORS. FARTHER S...THE WEAKER SRN WAVES WILL BE ABLE TO INTERACT WITH THE SFC-850MB WARM FRONT AND CONSIDERABLY MORE GENEROUS MOISTURE AS WELL AS ABUNDANT INSTABILITY. LEAD SUBTLE WAVE IS ALREADY GENERATING AN EXPANDING AREA OF SHRA/TSRA IN SRN MN/NW IA ON THE MUCAPE GRADIENT PER LATEST SPC MESOANALYSIS. THRU WED MORNING...MODELS SHOW 850MB WARM FRONT NEVER LIFTING ANY FARTHER N THAN SRN WI. BELIEVE THOSE MODEL SOLUTIONS WHICH SHOW THE MAIN AREA OF PCPN PASSING S OF UPPER MI TONIGHT/WED MORNING CLOSER TO 850MB WARM FRONT OR EVEN SFC FRONT ARE PROBABLY ON THE RIGHT TRACK. THIS WOULD BE ESPECIALLY TRUE IF SIGNIFICANT CONVECTION ENDS UP DEVELOPING/EXPANDING NEAR THE WARM FRONT...A DEFINITE POSSIBILITY GIVEN THE MAGNITUDE OF INSTABILITY THAT WILL REMAIN MUCH FARTHER S. WHILE THE SHRA/TSRA MOVING ACROSS SRN MN INTO SW WI IS A CONCERN...THAT PCPN SHOULD TEND TO PEEL MORE EASTWARD WITH TIME AS THE SHRA/TSRA SHOULDN`T BREAK TOO FAR AWAY FROM THE INSTABILITY GRADIENT WHICH WILL REMAIN WELL S OF HERE. SO...THE GFS WHICH CARRIES 1/3RD TO 1/2 INCH OF PCPN INTO SCNTRL UPPER MI CERTAINLY LOOKS LIKE AN OUTLIER COMPARED TO THE OTHER MODELS WHICH ARE MUCH LIGHTER ON PCPN. NONETHELESS...TAIL END OF NRN SHORTWAVE WILL PROVIDE SUPPORT FOR AN EXTENSION OF PCPN N AND NW FROM HEAVIER PCPN TO THE S. UTILIZING A CONSENSUS APPROACH FOR POPS...WEIGHTED TOWARD HIGH RES GUIDANCE...WILL SPREAD A BAND OF CHC POPS ACROSS THE AREA OVERNIGHT/WED MORNING WITH TREND TOWARD LOWER POPS OVER THE NRN/ERN FCST AREA. WILL INCLUDE LIKELY POPS INTO MENOMINEE COUNTY. PCPN WILL END (OR DIMINISH TO DZ BEFORE ENDING) FROM SW TO NE MID MORNING THRU EARLY AFTN. PTYPE IS A CHALLENGE. INITIAL DRY AIR MASS/EVAPORATIVE COOLING SHOULD MAKE SNOW THE MORE DOMINANT PTYPE. HOWEVER...PERUSAL OF MODEL FCST SOUNDINGS SHOW TEMP PROFILE HOVERING AROUND 0C OVER A FAIRLY SIGNIFICANT DEPTH...INDICATING A VARIETY OF PTYPES WILL BE POSSIBLE WITH ONLY VERY SLIGHT CHANGES TO THE TEMP PROFILE. SO...FCST WILL REFLECT A WINTRY MIX OF SN/IP/FZRA/RA AT MOST LOCATIONS...THOUGH MAINLY SN IS MORE LIKELY IN HIGHER TERRAIN AREAS. FOR PCPN AMOUNTS...EXPECT TOTAL WATER EQUIVALENT PCPN OF ROUGHLY 0.05 TO 0.15 INCHES....GREATEST SCNTRL. SNOW AMOUNTS SHOULD BE UNDER 1 INCH...AND WHERE FRZA OCCURS...A COUPLE OF HUNDREDTHS ARE POSSIBLE. AT THIS POINT...ADVY HEADLINES ARE NOT WARRANTED. IF FOR SOME REASON TRENDS THIS EVENING POINT TOWARD HEAVIER PCPN REACHING THE AREA...HEADLINES WILL NEED TO BE RECONSIDERED. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 431 AM EDT WED APR 8 2015 MAIN FCST CONCERN IN THE LONGER TERM PERIOD WL BE ON POPS/PTYPE FOR THE THU INTO FRI TIME IN ASSOCIATION WITH LO PRES THAT IS FCST TO MOVE NE FM THE PLAINS AND THRU THE GREAT LKS. THE EXACT DETAILS ON THIS FAIRLY COMPLEX SCENARIO...INCLUDING LO INTENSITY AND TRACK...WL DEPEND ON THE PHASING/INTERACTION BTWN NRN AND SRN BRANCH SHRTWVS AND THE EVENTUAL INTENSITY OF THE SRN BRANCH DISTURBANCE THAT IS NOW OVER THE SW CONUS. FORTUNATELY...THE LATEST ROUND OF EXPLICIT MODEL FCSTS IS BEGINNING TO COME INTO BETTER AGREEMENT ON THE FCST DETAILS. HI PRES AND TRANQUIL WX WL RETURN FOR SAT. THU/THU NGT...THE UPR FLOW ON THU WL FEATURE A NRN BRANCH SHRTWV DIGGING SE INTO NW ONTARIO WHILE SRN BRANCH SHRTWV THAT IS CURRENTLY OVER THE SW CONUS WL BE LIFTING NEWD TOWARD THE UPR MIDWEST ON THE NW FLANK OF UPR RDG OVER THE SE CONSU. ON THU NGT...SOME OF THE MODELS SHOW MORE PHASING BTWN THESE WAVES...WITH A DEEPER FARTHER W SFC LO TRACK AS FAR W AS UPR MI. IN GENERAL...RECENT ECMWF RUNS HAVE FAVORED THE LESS PHASED/WEAKER SRN BRANCH DISTURANCE AND WEAKER SFC LO SCENARIO...WHILE THE CNDN MODEL AND ESPECIALLY THE GFS RUNS HAVE SIDED WITH MORE PHASING AND A DEEPER SRN BRANCH SHRTWV/FARTHER W SFC LO TRACK. ALTHOUGH CHALLENGING A CONSISTENT ECMWF FCST IS RISKY... THE INTENSITY OF THE DISTURBANCE NOW OVER THE SW CONUS WOULD SEEM TO FAVOR A DEEPER AND FARTHER W SFC LO TRACK THAN SHOWN BY THE ECMWF RUNS...EVEN IF THERE IS NOT A LOT OF PHASING WITH THE NRN BRANCH SHRTWV. IN FACT...THE 00Z NAM DOES SUPPORT A 993MB SFC LO TRACKING ACROSS NW LOWER MI AT 06Z FRI TO THE E OF SLIGHTLY NEGATIVELY TILTED SRN BRANCH DISTURBANCE EVEN WITHOUT SGNFT PHASING WITH THE NRN SHRTWV. THE 00Z GFS REMAINS A BIT DEEPER WITH A 990MB SFC LO AT 06Z...BUT ITS LO TRACK IS NOW ONLY A BIT FARTHER W THAN SHOWN BY THE NAM. GIVEN THIS FAIRLY GOOD AGREEMENT AND PREFERENCE FOR A STRONGER SRN BRANCH SHRTWV...WL RELY ON THE 00Z NAM/GFS FCSTS FOR FCST DETAILS. QUICK LOOK AT THE 00Z ECMWF SHOWS A TREND IN THIS DIRECTION...INCRSG CONFIDENCE IN THE FCST. THESE MODELS SHOW SOME GENERALLY LGT PCPN DVLPG ON THU MRNG WITH LARGER SCALE ISENTROPIC ASCENT TO THE NE OF THE APRCHG SRN BRANCH SHRTWV/SFC LO. EXCEPT OVER THE FAR NW CWA OVER LK SUP...THIS PCPN WL BE LIQUID AS H85 TEMPS ARE FCST TO BE HIER THAN 0C. BUT LINGERING NEAR SFC COLD AIR/HI STABILITY SHOWN ON FCST SDNGS WL SUPPORT GOING FCST OF FREEZING RA OVER MUCH OF THE CWA BEFORE SOME WARMING ALLOWS TEMPS TO RISE ABOVE 32 AT MOST PLACES AND CHANGES THE PCPN TO PLAIN RA WITH SLOW INFLUX OF WARMER NEAR SFC AIR. GIVEN THE MOISTENING SHALLOW STABLE LYR...ADDED SOME PATCHY FOG FOR MOST OF THE CWA. AS THE DAY WEARS ON AND THE SRN BRANCH SHRTWV APRCHS...THE ARRIVAL OF MORE VIGOROUS DEEP LYR QVECTOR CNVGC/UPR DVGC/AXIS OF MID LVL FGEN THAT WL SUPPORT SHARPENING H85 THERMAL GRADIENT WL SUPPORT HIER POPS/QPF. OVER THE W...THE FCST THERMAL FIELDS WITH THIS MORE VIGOROUS UVV INDICATE A MIX WITH SN TOWARD 00Z FRI. DESPITE THE DIFFERENCES ON THE PHASING BTWN BRANCHES...ALL THE MODELS ARE IN FAIRLY GOOD AGREEMENT SHOWING SOME ENHANCED UPR DVGC OVER THE CWA ON THU NGT IN COUPLED UPR JET STRUCTURE...RRQ OF NRN BRANCH JET CORE NEAR JAMES BAY AND LEFT EXIT OF SRN BRANCH JET STREAK MOVING TOWARD LOWER MI. THIS SHARPER UPR DVGC SHOULD ENHANCE UVV/DYNAMIC COOLING AND LEAD TO A CHANGE TO MAINLY SN W-E. ALTHOUGHTHERE ARE SOME SUBTLE DIFFERENCES EVEN AMONG THE NAM AND GFS...LOOKS LIKE THE W AND CENTRAL PORTIONS OF CWA HAVE THE BEST CHC FOR SEEING SOME HEADLINE SN AMOUNTS GIVEN TRACK OF SHRTWV AND PLACEMENT ON CYC SIDE OF ACCOMPANYING H7 LO TRACK/HINT OF A TROWAL FEATURE UNDER AXIS OF HIER H7 SPECIFIC HUMIDITY AOA 4 G/KG. AT THIS POINT...DECIDED TO ISSUE AN SPS TO COVER THE COMPLEX WINTER WX/MIXED PCPN EXPECTED THIS MRNG AND THEN AGAIN LATE TNGT THRU THU NGT. FRI...AS SRN SHRTWV LIFTS TO THE NE AND LINGERING DEEP LYR QVECTOR CNVGC EXITS TO THE NE IN THE MRNG...EXPECT PCPN TO DIMINISH... ESPECIALLY IN THE AFTN WITH APRCH OF SFC HI PRES AND WEAKENING CYC NW FLOW. BUT PASSING NRN BRANCH SHRTWV/AXIS OF SOME QVECTOR CNVGC WL MAINTAIN AT LEAST POPS. ANY LINGERING SN SHOWERS WL LIKELY MIX WITH RA IN THE PRESENCE OF DAYTIME HEATING. FRI NGT THRU SAT NGT...HI PRES IS FCST TO FOLLOW INTO THE WRN LKS ON FRI NGT AND END ANY LINGERING PCPN. AS THE RDG AXIS/DRIER AIRMASS WITH PWAT AOB 0.25 INCH TRACK OVER THE UPR LKS ON SAT...EXPECT MOSUNNY AND WARMER WX AS H85 TEMPS REBOUND TO ARND 4C. MAX TEMPS SHOULD RISE WELL INTO THE 50S AWAY FM LK MODERATION. A WAA REGIME WL TAKE OVER ON SAT NGT AND BRING A RETURN OF AT LEAST SOME MID CLDS AS THE SFC HI PRES SHIFTS TO THE E AND A STRONG SW WIND DEVELOPS. RECENT GFS RUNS HAVE GENERATED SOME LGT PCPN AS PWAT REBOUNDS CLOSE TO 0.75 INCH. BUT SINCE MOST OF THE GUIDANCE SHOWS A DRY FCST... WENT NO HIER THAN SCHC POPS. SUN THRU TUE...A SHRTWV TRACKING THRU CENTRAL CANADA WL DRAG A COLD FNT THRU THE UPR LKS LATE THIS WEEKEND/EARLY NEXT WEEK. THE AIRMASS IN PLACE WL BE WARM ENUF FOR ALL LIQUID PCPN DURING THIS FROPA...WHICH WL BE FOLLOWED BY A MARITIME POLAR PACIFIC AIRMASS. SO TEMPS SHOULD AVERAGE AOA NORMAL ON SUN THRU TUE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 129 AM EDT WED APR 8 2015 AS A DISTURBANCE MOVES INTO THE GREAT LAKES TONIGHT...LIGHT PCPN WILL PROBABLY AFFECT ALL TERMINALS LATE TONIGHT INTO WED MORNING. ALONG WITH -SN...THERE MAY BE SOME -RA/-FZRA/PL...THOUGH CONFIDENCE IS QUITE LOW ON PTYPE. EXPECT MVFR CONDITIONS TO EVENTUALLY DEVELOP...AND LINGER THRU THE END OF THE FCST PERIOD...ALTHOUGH PCPN SHOULD GENERALLY END BY LATE WED MORNING/WED AFTERNOON IN THE WAKE OF THE DISTURBANCE. THERE IS A CHANCE FOR IFR CONDITIONS TO DEVELOP AT KSAW WED EVENING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 448 PM EDT TUE APR 7 2015 WITH LAKE SUPERIOR SITUATED BETWEEN HIGH PRES THAT WILL MOVE FROM NRN ONTARIO INTO QUEBEC THRU WED AND A WARM FRONT THAT WILL REMAIN TO THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO NE WINDS WILL PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE STRONGEST OVER WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE ISLANDS AND MN NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE THE WINDS. IN THAT AREA...EXPECT NE WINDS OF 20-30KT TONIGHT...WITH SOME GALE FORCE GUSTS TO AROUND 35 KT THRU THE EVENING. E TO NE WINDS...MOSTLY 10-20KT...WILL THEN CONTINUE ON WED AND ON INTO THU AS LOW PRES LIFTS NE FROM THE CENTRAL PLAINS INTO THE GREAT LAKES REGION. AT THIS TIME...IT APPEARS THE LOW WILL NOT BE STRONG ENOUGH TO RESULT IN GALES AS THE LOW APPROACHES AND THEN DEPARTS. WINDS WILL BACK TO THE N THU AND THEN NW 20-30KT THU NIGHT INTO FRI AS THE LOW SHIFTS TO THE E AND HIGH PRES BUILDS INTO THE PLAINS. A PERIOD OF LIGHT WINDS WILL OCCUR FRI NIGHT INTO SAT AS HIGH PRES RIDGE MOVES ACROSS THE UPPER LAKES. S WINDS WILL THEN BE ON THE INCREASE TO AT LEAST 10-20KT ON SUN AS THE RIDGE SHIFTS E AND A LOW PRES TROF MOVES E TO THE UPPER MISSISSIPPI VALLEY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KC AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
129 AM EDT WED APR 8 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 448 PM EDT TUE APR 7 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THAT THE CONFLUENT FLOW THAT HAS BEEN ACROSS THE UPPER GREAT LAKES IS SHIFTING E AND NE AS THE NRN STREAM TROF OVER ERN CANADA IS SLOWLY LIFTING OUT AND SRN BRANCH RIDGE OVER THE PLAINS DOWNSTREAM OF TROF ALONG THE W COAST IS GRADUALLY BUILDING NE AND E. SFC HIGH PRES SUPPORTED BY THE CONFLUENT FLOW ALOFT RIDGES W-E ACROSS NRN ONTARIO INTO SRN QUEBEC. ALTHOUGH THERE HAVE BEEN SOME MID-LEVEL RADAR RETURNS ACROSS THE FCST AREA...ESPECIALLY EARLIER TODAY...THE VERY DRY AIR AT THE LOWER LEVELS EMANATING FROM THE HIGH PRES RIDGE HAS RESULTED IN DRY WEATHER ACROSS THE FCST AREA TODAY. IN FACT...THE KEWEENAW AND ERN UPPER MI HAVE ENJOYED MOSTLY SUNNY SKIES FOR A GOOD PART OF THE DAY. TO THE S...WARM FRONT/STATIONARY FRONT EXTENDS FROM KS ACROSS CNTRL IL INTO NRN OHIO. TO THE W AND SW...A WELL-DEFINED SHORTWAVE IS TRACKING ENE ACROSS SE SASKATCHEWAN WHILE WEAKER WAVES ARE MOVING ACROSS WY/CO AND OUT ACROSS THE PLAINS. THESE FEATURES WILL PLAY A ROLE IN A CHALLENGING FCST HERE TONIGHT/WED. INITIALLY...EXPECT DRY WEATHER TO PREVAIL THIS EVENING UNDER A CONTINUED FEED OF DRY LOW-LEVEL AIR FROM THE E AND NE. SFC DWPTS AS OF 19Z WERE STILL MOSTLY IN THE 5-10F RANGE ALONG THE MI/WI BORDER...INDICATING THE DRYNESS THAT IS STILL AT THE SFC...AND LATEST RAP FCST SOUNDINGS SHOW THE DRY AIR IN THE LOWER LEVELS HANGING ON DURING THE EVENING. LATER TONIGHT INTO WED...FOCUS SHIFTS TO THE AFORMENTIONED SHORTWAVES. THE STRONGER NRN WAVE WILL REACH NRN ONTARIO EARLY WED MORNING WHILE THE WEAKER SRN WAVES WILL TRACK INTO THE UPPER LAKES. TRACK OF THE STRONGER NRN WAVE INDICATES ITS MAIN FORCING WILL PASS N OF HERE...AND THAT IS WHAT MODELS SHOW FOR PROGRESSION OF DEEP LAYER QVECTORS. FARTHER S...THE WEAKER SRN WAVES WILL BE ABLE TO INTERACT WITH THE SFC-850MB WARM FRONT AND CONSIDERABLY MORE GENEROUS MOISTURE AS WELL AS ABUNDANT INSTABILITY. LEAD SUBTLE WAVE IS ALREADY GENERATING AN EXPANDING AREA OF SHRA/TSRA IN SRN MN/NW IA ON THE MUCAPE GRADIENT PER LATEST SPC MESOANALYSIS. THRU WED MORNING...MODELS SHOW 850MB WARM FRONT NEVER LIFTING ANY FARTHER N THAN SRN WI. BELIEVE THOSE MODEL SOLUTIONS WHICH SHOW THE MAIN AREA OF PCPN PASSING S OF UPPER MI TONIGHT/WED MORNING CLOSER TO 850MB WARM FRONT OR EVEN SFC FRONT ARE PROBABLY ON THE RIGHT TRACK. THIS WOULD BE ESPECIALLY TRUE IF SIGNIFICANT CONVECTION ENDS UP DEVELOPING/EXPANDING NEAR THE WARM FRONT...A DEFINITE POSSIBILITY GIVEN THE MAGNITUDE OF INSTABILITY THAT WILL REMAIN MUCH FARTHER S. WHILE THE SHRA/TSRA MOVING ACROSS SRN MN INTO SW WI IS A CONCERN...THAT PCPN SHOULD TEND TO PEEL MORE EASTWARD WITH TIME AS THE SHRA/TSRA SHOULDN`T BREAK TOO FAR AWAY FROM THE INSTABILITY GRADIENT WHICH WILL REMAIN WELL S OF HERE. SO...THE GFS WHICH CARRIES 1/3RD TO 1/2 INCH OF PCPN INTO SCNTRL UPPER MI CERTAINLY LOOKS LIKE AN OUTLIER COMPARED TO THE OTHER MODELS WHICH ARE MUCH LIGHTER ON PCPN. NONETHELESS...TAIL END OF NRN SHORTWAVE WILL PROVIDE SUPPORT FOR AN EXTENSION OF PCPN N AND NW FROM HEAVIER PCPN TO THE S. UTILIZING A CONSENSUS APPROACH FOR POPS...WEIGHTED TOWARD HIGH RES GUIDANCE...WILL SPREAD A BAND OF CHC POPS ACROSS THE AREA OVERNIGHT/WED MORNING WITH TREND TOWARD LOWER POPS OVER THE NRN/ERN FCST AREA. WILL INCLUDE LIKELY POPS INTO MENOMINEE COUNTY. PCPN WILL END (OR DIMINISH TO DZ BEFORE ENDING) FROM SW TO NE MID MORNING THRU EARLY AFTN. PTYPE IS A CHALLENGE. INITIAL DRY AIR MASS/EVAPORATIVE COOLING SHOULD MAKE SNOW THE MORE DOMINANT PTYPE. HOWEVER...PERUSAL OF MODEL FCST SOUNDINGS SHOW TEMP PROFILE HOVERING AROUND 0C OVER A FAIRLY SIGNIFICANT DEPTH...INDICATING A VARIETY OF PTYPES WILL BE POSSIBLE WITH ONLY VERY SLIGHT CHANGES TO THE TEMP PROFILE. SO...FCST WILL REFLECT A WINTRY MIX OF SN/IP/FZRA/RA AT MOST LOCATIONS...THOUGH MAINLY SN IS MORE LIKELY IN HIGHER TERRAIN AREAS. FOR PCPN AMOUNTS...EXPECT TOTAL WATER EQUIVALENT PCPN OF ROUGHLY 0.05 TO 0.15 INCHES....GREATEST SCNTRL. SNOW AMOUNTS SHOULD BE UNDER 1 INCH...AND WHERE FRZA OCCURS...A COUPLE OF HUNDREDTHS ARE POSSIBLE. AT THIS POINT...ADVY HEADLINES ARE NOT WARRANTED. IF FOR SOME REASON TRENDS THIS EVENING POINT TOWARD HEAVIER PCPN REACHING THE AREA...HEADLINES WILL NEED TO BE RECONSIDERED. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 414 PM EDT TUE APR 7 2015 ...AREAS OF FREEZING RAIN/ICING WED NIGHT INTO THU MORNING AND POSSIBLE HEAVY SNOW THU NIGHT... LARGE SCALE UPPER LEVEL PATTERN TO START THE LONG TERM FEATURES TROUGHING FM CENTRAL CANADA SOUTHWEST ACROSS MUCH OF THE WESTERN CONUS. MAIN SHORTWAVES WITHIN THE TROUGH ON WEDNESDAY NIGHT WILL BE DIVING SOUTHEAST ACROSS MANITOBA AND STREAMING EASTWARD NEAR THE FOUR CORNERS REGION. MAIN JET STREAKS WITHIN THE FLOW PATTERN ARE ORIENTED FM GREAT LAKES TO NEW ENGLAND AND PUSHING ACROSS NORTHERN MEXICO. AT THE SFC...MAIN CYCLONE IS VCNTY OF CNTRL PLAINS WITH WARM FRONT EAST ACROSS THE OHIO VALLEY...LIFTING NORTHWARD. WEAKER LEAD SHORTWAVE/INCREASING DIVERGENCE IN RRQ OF GREAT LAKES JET/WARM AIR ADVECTION COMBINE TO BRING SOME PRECIP IN THE FORM OF RAIN SHOWERS OVER THE REGION WEDNESDAY NIGHT INTO THURSDAY MORNING. GFS/ECMWF/GEM-NH QUICKER IN BRINGING PRECIP OVER AREA...MORE 06Z-12Z THURSDAY. NAM IS DELAYED...FAVORING 12Z-18Z ON THURSDAY. EITHER WAY THINK BEST FOCUS FOR RAIN WILL BE ON NOSE OF VEERING H85 JET MAINLY IMPACTING SOUTH AND EAST CWA. TSRA THAT COULD BE ONGOING ALONG WARM FRONT COULD FURTHER DISRUPT MOISTURE TRANSPORT INTO UPPER GREAT LAKES. DUE TO THESE REASONS...LIKE THE IDEA OF LESS QPF SINCE LARGER SCALE FORCING OVER UPR MICHIGAN IS GENERALLY WEAK. SOUNDINGS AHEAD OF ANY POTENTIAL PRECIP INDICATE LOW-LEVEL MOISTURE TO H9 BUT DRY AIR ABOVE THROUGH H5 MUCH OF WEDNESDAY EVENING. SFC WINDS FM EAST BTWN HIGH PRESSURE RIDGE OVER EASTERN CANADA AND LOW PRESSURE LIFTING NORTHEAST OVER THE CNTRL PLAINS SUPPORTS BEST CHANCE OF DZ/FZDZ GENERATED BY UPSLOPE LIFTING OVER HIGHER TERRAIN OF CNTRL CWA FM MICHIGAMME HIGHLANDS IN BARAGA AND MARQUETTE COUNTY SOUTHWEST TO MUCH OF IRON AND DICKINSON COUNTIES. EITHER FM THE FZDZ OR EVENTUALLY ARRIVAL OF LIGHT FZRA...LIGHT ICING IS LIKELY ON WEDNESDAY NIGHT AS TEMPS WILL STAY AT OR BLO FREEZING MOST OF THE NIGHT. MAIN CONCERN WOULD BE ON UNTREATED ROADS AND SIDEWALKS BUT THERE COULD ALSO BE SOME ICING THAT WOULD IMPACT ELEVATED OBJECTS SUCH AS TREES AND POWERLINES. BEST SHOT OF MOST ICING WILL BE OVER THE HIGHER TERRAIN AREAS FM BARAGA AND MARQUETTE COUNTY TO IRON AND DICKINSON COUNTY. DID NOT GET TOO SPECIFIC BTWN DZ/FZDZ AND RAIN/FZRA. SINCE EVEN IN THE DRIER SCENARIO THERE WOULD BE MEASURABLE QPF...WENT WITH RAIN/FZRA. WILL KEEP MENTION OF THIS IN HWO/EHWO...BUT NO HEADLINE ISSUED NOW AS AT THIS POINT SEEMS THAT AT WORST COULD NEED AN ADVY. BRIEF LULL POSSIBLE LATER THURSDAY MORNING INTO THURSDAY AFTERNOON IN BETWEEN SHORTWAVES...LEAD ONE LIFTING ACROSS EASTERN ONTARIO AND A MUCH STRONGER ONE...EDGING EASTWARD ACROSS CNTRL PLAINS...SET TO ARRIVE OVER UPR GREAT LAKES THURSDAY NIGHT. SOUNDINGS FOR LATER THURSDAY INDICATE SOME MOISTURE MAY STICK AROUND ON NORTHERN EDGE OF SFC LOW LIFTING NORTHEAST FROM THE CNTRL MISSISSIPPI RIVER VALLEY TOWARD THE WESTERN GREAT LAKES...BUT SEEMS THAT NET FORCING FOR ANY PRECIP WILL BE MINIMAL. NORTHERN EDGE OF HIGHER MLCAPE AND INTERSECTION OF LOW-LEVEL AND UPPER LEVEL JET AND H85 THETA-E AXIS/MAX WARM AIR ADVECTION WOULD KEEP POTENTIAL FOR TSRA STAYING WELL TO THE SOUTHEAST OF UPR MICHIGAN...LIKELY OVER LOWER GREAT LAKES OR OHIO VALLEY DEPENDING ON LOCATION OF EMBEDDED WEAKER CONVECTIVELY DRIVEN SHORTWAVES IN THE WSW FLOW ALOFT. GENERALLY QUIET WEATHER SHOULD PREVAIL OVER UPPER LAKES THURSDAY AFTN UNTIL MAIN SHORTWAVE ARRIVES ON THURSDAY NIGHT. MOISTURE ADVECTION INTO THE AREA MAY CONTINUE TO SPUR ON SOME SHOWERS OR PATCHY RAIN...SO KEPT CHANCES GOING THROUGH THE PERIOD DESPITE THE MINIMAL FORCING. MODEL DIFFERENCES WITH STRENGTH AND WESTWARD EXTENT OF THURSDAY NIGHT SHORTWAVE IS THE MAIN ISSUE ON INTO FRIDAY MORNING. OVERALL... RECENT NAM/GEM-NH RUNS WERE FARTHER WEST WITH UPPER WAVE AND SFC LOW WHILE THE 00Z ECMWF WAS MUCH FASTER WITH EASTWARD PUSH OF THE SHORTWAVE/SFC LOW AND COLD FRONT. GFS REPRESENTED A COMPROMISE SOLUTION. BY FAR...00Z AND 12Z ECMWF ARE DRIEST...INDICATING LESS THAN 0.25 INCH OF QPF FM 00Z FRIDAY TO 12Z FRIDAY. MEANWHILE... NAM/GFS/GEM-NH SHOWED QPF AMOUNTS AT LEAST UP TO 1 INCH...SO QUITE THE DIFFERENCE. 12Z NAM TRENDED MORE LIKE THE GFS IN TERMS OF LOCATION OF SFC LOW FM 00Z FRIDAY TO 12Z FRIDAY. IN TERMS OF QPF...NAM TRENDED AWAY FM STRIPE OF 1.5 INCH PLUS AMOUNTS IT WAS SHOWING BUT STILL HAS UP TO 1.25 INCHES OVER PARTS OF WESTERN UPR MICHIGAN. IN FACT...IN THE VCNTY OF KIWD IS HAS TRENDED MUCH WETTER AS 00Z RUN SHOWED LESS THAN 0.10 INCH...BUT 12Z RUN NOW HAS ALMOST 0.75 INCHES. GUESSING THIS IS DUE TO MORE PHASING OCCURRING BTWN SHORTWAVE CROSSING THE UPPER LAKES AND THE APPROACHING WAVE DRIVING SOUTHEAST OVER MANITOBA AND NORTHERN ONTARIO WHICH IN TURN INCREASES RIGHT ENTRANCE JET STREAK DIVERGENCE AND ASSOCIATED MID-LEVEL FGEN. 12Z GFS SIMILAR TO PREVIOUS RUNS WITH SFC LOW POSITION...BUT NOW FOCUSES QPF MORE OVER WESTERN CWA. GFS SHOWS NOT ONLY MAIN SHORTWAVE LIFTING OVER UPPER GREAT LAKES AND WAVE OVER NORTHERN ONTARIO...BUT ALSO ANOTHER WAVE TRYING TO SNEAK IN FM NORTHERN PLAINS. SCENARIO JUST BECOMES MORE COMPLICATED YET. PTYPE WITH MOST OF THE PRECIP WOULD BE RAIN CHANGING TO SNOW. POSSIBLE FZRA AS WELL AS ADVECTION OF COLDER LOW- LEVEL AIRMASS UNDERCUTS LINGERING WARM LAYER ALOFT AT H8-H75. SIGNAL FOCUSING THAT FAR WEST VCNTY OF KIWD COULD SEE HEAVY SNOW THURSDAY EVENING INTO THE EARLY MORNING OF FRIDAY DUE TO QUICKER CHANGE FM RAIN TO SNOW AND GREATER POTENTIAL FOR HEAVIER QPF. WILL CONTINUE TO MENTION THIS IN THE HWO/EHWO BUT NOT HIT IT UP MUCH HARDER JUST YET AS UNCERTAINTY REMAINS SINCE THE TYPICALLY BETTER PERFORMING ECMWF HAS BEEN CONSISTENTLY NOT NEAR AS BULLISH WITH THE SYSTEM AS OTHER MODELS. AND ITS REALLY NOT EVEN CLOSE. LOW PRESSURE SYSTEM EXITS ACROSS EASTERN CANADA ON FRIDAY. LINGERING AIRMASS IS COOL THOUGH AS LOWERED TEMPS WITH THERMAL TROUGH AT H85 REMAINING OVER THE AREA. SHOULD STAY MOSTLY CLOUDY EVEN FARTHER INLAND WITH POSSIBLE INSTABILITY RAIN/SNOW SHOWERS SINCE THE THERMAL TROUGH STAYS IN THE VCNTY. HIGH PRESSURE SLIDES OVERHEAD TO START THE WEEKEND SO LOOKING FOR DRY AND MUCH WARMER CONDITIONS ON SATURDAY. WINDS BECOME SOUTHWEST AS RIDGE PASSES SATURDAY AFTN. MIXING TO H9 WOULD SUPPORT HIGHS WELL INTO THE 50S OVER MOST CWA. BY LATE WEEKEND...UPPER PATTERN SHOWS LARGER TROUGH OVER WESTERN CANADA AND NORTHWEST CONUS...WITH MORE COMPACT UPPER LOW TRACKING OVER THE SOUTHWEST CONUS. THERE IS A LOT OF UNCERTAINTY IN HOW THAT SOUTHERN STREAM WAVE EVOLVES. PREVIOUS ECMWF SHOWED A WRAPPED UP SFC LOW OVER THE CNTRL PLAINS...WHILE THE 12Z ECMWF SHOWS NOTHING OF THE SORT. ESSENTIALLY...SEE NO REASON TO STRAY FM CONSENSUS BEYOND THE LATE WEEK SYSTEM GIVEN THE BIGGER UNCERTAINTY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 129 AM EDT WED APR 8 2015 AS A DISTURBANCE MOVES INTO THE GREAT LAKES TONIGHT...LIGHT PCPN WILL PROBABLY AFFECT ALL TERMINALS LATE TONIGHT INTO WED MORNING. ALONG WITH -SN...THERE MAY BE SOME -RA/-FZRA/PL...THOUGH CONFIDENCE IS QUITE LOW ON PTYPE. EXPECT MVFR CONDITIONS TO EVENTUALLY DEVELOP...AND LINGER THRU THE END OF THE FCST PERIOD...ALTHOUGH PCPN SHOULD GENERALLY END BY LATE WED MORNING/WED AFTERNOON IN THE WAKE OF THE DISTURBANCE. THERE IS A CHANCE FOR IFR CONDITIONS TO DEVELOP AT KSAW WED EVENING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 448 PM EDT TUE APR 7 2015 WITH LAKE SUPERIOR SITUATED BETWEEN HIGH PRES THAT WILL MOVE FROM NRN ONTARIO INTO QUEBEC THRU WED AND A WARM FRONT THAT WILL REMAIN TO THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO NE WINDS WILL PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE STRONGEST OVER WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE ISLANDS AND MN NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE THE WINDS. IN THAT AREA...EXPECT NE WINDS OF 20-30KT TONIGHT...WITH SOME GALE FORCE GUSTS TO AROUND 35 KT THRU THE EVENING. E TO NE WINDS...MOSTLY 10-20KT...WILL THEN CONTINUE ON WED AND ON INTO THU AS LOW PRES LIFTS NE FROM THE CENTRAL PLAINS INTO THE GREAT LAKES REGION. AT THIS TIME...IT APPEARS THE LOW WILL NOT BE STRONG ENOUGH TO RESULT IN GALES AS THE LOW APPROACHES AND THEN DEPARTS. WINDS WILL BACK TO THE N THU AND THEN NW 20-30KT THU NIGHT INTO FRI AS THE LOW SHIFTS TO THE E AND HIGH PRES BUILDS INTO THE PLAINS. A PERIOD OF LIGHT WINDS WILL OCCUR FRI NIGHT INTO SAT AS HIGH PRES RIDGE MOVES ACROSS THE UPPER LAKES. S WINDS WILL THEN BE ON THE INCREASE TO AT LEAST 10-20KT ON SUN AS THE RIDGE SHIFTS E AND A LOW PRES TROF MOVES E TO THE UPPER MISSISSIPPI VALLEY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
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
AREA FORECAST DISCUSSION
NWS DULUTH MN
326 AM CDT WED APR 8 2015 .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 325 AM CDT WED APR 8 2015 LAST OF THE PIECES OF SHORT WAVE ENERGY EARLY THIS MORNING WAS MOVING ALONG THE INTERNATIONAL BORDER WHILE ANOTHER WAS EXITING NW WI JUST BEFORE 08Z. THE LIGHT FREEZING RAIN IS COMING TO AN END...BUT SOME LIGHT SNOW REMAINS ALONG THE INTERNATIONAL BORDER AREA. CALLS TO AREA LAW ENFORCEMENT REVEALED NO SLIPPERY ROADS DUE TO THE FREEZING RAIN. THE LIGHT ICE ACCUMULATION WAS ALL ELEVATED. 2 INCHES OF SNOW WAS REPORTED AT INL WITH THE 06Z OB. LITTLE IN THE WAY OF ADDITIONAL ACCUMULATION IS EXPECTED BEFORE 12Z. MODELS ARE INDICATING ONE LAST PIECE OF ENERGY WILL CROSS NORTHERN MN THIS MORNING AND HAVE POPS AROUND THE PERIPHERY OF LAKE SUPERIOR TO REFLECT THIS TREND. THERE IS STILL A POTENTIAL FOR SOME LIGHT FREEZING RAIN...SNOW OR SLEET...ESPECIALLY OVER THE TIP OF THE ARROWHEAD. HAVE A LIGHT ICE ACCUMULATION MENTIONED. ELSEWHERE...THE HIGH PRESSURE REMAINS IN CHARGE. THE PRECIPITATION WILL END BY 15Z. MODELS ARE IN GENERAL AGREEMENT WEDNESDAY EVENING WITH SFC RIDGING COVERING A MAJORITY OF THE FORECAST AREA. THE EXCEPTION IS THE NAM WHICH IS TRYING TO GENERATE SOME PCPN UP THE NORTH SHORE. GFS IS TOO FAST AND TOO FAR NORTH WITH ITS QPF PRIOR TO 06Z. AS A COMPROMISE...HAVE SOME SMALL POPS TO ACCOUNT FOR THESE TRENDS. AFTER 06Z...MODEL DIFFERENCES BECOME A BIT LARGER WITH RESPECT TO NEXT ROUND OF PCPN SPREADING NORTHWARD FROM SOUTHERN MINNESOTA AND HIGH PRESSURE OVER THE FORECAST AREA. TRIED TO ALIGN POPS/QPF/WEATHER TO BETTER REFLECT MODEL SOLUTIONS AND MATCH NEIGHBORING OFFICES. THERE WILL BE MORE MIXED PCPN AS WAA MOVES OVER THE TOP OF COLD AIR IN THE LOWEST LEVELS. ON THURSDAY...A SFC LOW WILL MOVE FROM SW IA TO SE WI. MEANWHILE...AN UPPER LEVEL TROF WITH SEVERAL PIECES OF SHORT WAVE ENERGY WILL AFFECT THE FORECAST AREA. AT THIS TIME...IT APPEARS THAT NO PCPN WILL OCCUR TO THE WEST OF A LINE FROM LONGVILLE TO HIBBING TO NEAR ELY. HAVE REMOVED POPS AS A RESULT. EXPECT A RAIN/SNOW/SLEET MIX IN THE MORNING BEFORE TRANSITIONING TO ALL SNOW IN THE AFTERNOON. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 325 AM CDT WED APR 8 2015 COLD UPPER TROUGH WILL BE SLOWLY EXITING TO THE ESE THURSDAY NIGHT AND FRIDAY MORNING WITH A WINTRY MIX OF RAIN...SNOW...SLEET AND POSSIBLY FREEZING RAIN ASSOCIATED WITH IT THURSDAY EVENING AND A CHANGE OVER TO ALL SNOW LATE THURSDAY NIGHT. COULD SEE A COUPLE INCHES OF SNOW/SLEET OVER PORTIONS OF NW WI DURING THIS TIME...WITH LIGHT ICING AS WELL. TRAVEL CONDITIONS COULD DETERIORATE RAPIDLY. AS THE MAIN FORCING FROM THIS SYSTEM MOVES EWD...THE COLD AIR BEHIND THE FRONT WILL POUR IN FROM THE NW AND TRIGGER ADDITIONAL CHANCES FOR WEAK CONVECTIVE SNOW SHOWERS FRIDAY MORNING AND RAIN SHOWERS IN THE AFTERNOON. ADDITIONAL PRECIP AMTS WILL BE LIGHT. A LARGE WARM RIDGE OF HIGH PRESSURE WILL BUILD IN THIS WEEKEND AND KEEP CONDITIONS QUIET THROUGH SUN MORNING. THE NEXT TROUGH MOVES IN SUNDAY AFTERNOON WITH LIGHT RAIN CHANCES INTO EARLY MONDAY. HIGH PRESSURE SETTLES IN OVER NORTHERN MINNESOTA BY TUESDAY. TEMPERATURES WILL WARM QUICKLY THROUGH THE END OF THE WEEK WITH HIGHS ON FRIDAY IN THE UPPER 30S TO LOWER 50S...AND INTO THE 50S AND LOWER 60S BY SUNDAY. OVERNIGHT LOWS IN THE 20S AND LOWER 30S ARE EXPECTED FRI AND SAT MORNING...WITH 30S AND 40S LATER IN THE WEEKEND AND EARLY NEXT WEEK. CONDITIONS WILL REMAIN MILD INTO THE EARLY TO MIDDLE PART OF NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1220 AM CDT WED APR 8 2015 PRECIPITATION RANGED FROM LIGHT RAIN OVER PORTIONS OF NORTHERN WISCONSIN...TO SNOW ALONG THE INTERNATIONAL BORDER. BETWEEN THESE TWO AREAS WAS SLEET...SNOW AND FREEZING RAIN. IFR CONDITIONS WILL OCCUR IN THE HEAVIER SNOW OVER FAR NORTHERN MINNESOTA...WITH MAINLY MVFR CONDITIONS ELSEWHERE. THE PRECIPITATION WILL DIMINISH FROM THE WEST AND SOUTH LATER TONIGHT. A PERIOD OF FREEZING DRIZZLE/DRIZZLE AND FOG WILL BE POSSIBLE AS THE PRECIP EXITS THE AREA AND A MIX OF LOW MVFR/IFR CONDITIONS WILL PREVAIL INTO WEDNESDAY MORNING. THE LATEST NAM SUGGEST CEILINGS WILL RISE THROUGH THE DAY AND BECOME SCATTERED IN SPOTS. HOWEVER...THE LATEST RAP KEEPS THE CLOUDS AROUND LONGER. WE SIDED WITH THE RAP. SOME OF THE GUIDANCE SHOWS SOME FOG AND LOWER CEILINGS MOVING BACK IN WEDNESDAY EVENING...AND WE TRENDED THAT WAY. && .PRELIMINARY POINT TEMPS/POPS... DLH 39 31 41 31 / 10 50 60 30 INL 45 29 49 28 / 0 30 0 30 BRD 48 35 48 27 / 0 60 40 20 HYR 48 35 42 30 / 10 60 80 60 ASX 41 32 38 30 / 20 50 80 70 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121- 141>148. && $$ SHORT TERM...GSF LONG TERM...BJT AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1222 AM CDT WED APR 8 2015 .UPDATE... ISSUED AT 1220 AM CDT WED APR 8 2015 UPDATED FOR AVIATION DISCUSSION BELOW. UPDATE ISSUED AT 936 PM CDT TUE APR 7 2015 HAVE UPDATED GRIDS THIS EVENING TO ACCOUNT FOR LATEST TRENDS REGARDING COVERAGE AND PRECIP TYPE. SPOTTER AND LAW ENFORCEMENT REPORT FREEZING RAIN OVER PORTIONS OF AITKIN AND FAR SOUTHERN ITASCA COUNTIES WITH SLEET AND SNOW FURTHER NORTH. WE THOUGHT ABOUT ISSUING AN ADVISORY FOR SEVERAL HOURS IN THE AREA GETTING THE FREEZING RAIN...BUT DECIDED TO HOLD OFF FOR NOW BASED ON CURRENT RADAR TRENDS. WE WILL WATCH CLOSELY. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 335 PM CDT TUE APR 7 2015 CLOUDY TODAY WITH BREEZY CONDITIONS ALONG THE HEAD OF LAKE SUPERIOR DUE TO NORTHEASTERLY WINDS ACROSS THE LAKE. TONIGHT A COMPLEX WINTRY MIX WILL DEVELOP ACROSS MUCH OF THE REGION WHICH WILL BRING A MIX OF SNOW...SLEET...AND FREEZING RAIN AND POSSIBLY RESULT IN A MESSY WEDNESDAY MORNING COMMUTE FOR THE NORTHLAND. A MID-LEVEL DRY SLOT WILL BE QUICK TO MOVE IN BEHIND THIS SYSTEM BY WEDNESDAY MORNING BUT LOW LEVEL CLOUDS WILL STICK AROUND FOR MOST OF THE DAY. ON THE SYNOPTIC SCALE THE PRIMARY FEATURE AFFECTING OUR WEATHER IN THE SHORT TERM IS A MID-LEVEL SHORTWAVE TROUGH MOVING ACROSS SOUTHERN SASASK/MANITOBA. ACROSS THE CONUS A DEEPENING TROUGH OFF THE CALIFORNIA COAST AND A NEAR-ZONAL FLOW ACROSS THE EASTERN SEABOARD IS RESULTING IN SOUTHWESTERLY FLOW FROM THE CENTRAL/SOUTHERN ROCKIES AND DESERT SOUTHWEST EAST TO THE UPPER GREAT LAKES AND MISSISSIPPI RIVER VALLEY. AT THE SURFACE AN AREA OF HIGH PRESSURE OVER MUCH OF ONTARIO AND A SFC LOW IN EASTERN KANSAS IS RESULTING IN EASTERLY FLOW AT THE SFC. REST OF TODAY...GENERALLY CLOUDY AND SLIGHTLY COOLER THAN NORMAL. IN THE TWIN PORTS AND NEARBY COASTAL AREAS WINDS ARE BREEZY /GUSTING TO NEAR 30 KTS/ DUE TO NORTHEASTERLY WINDS ACROSS LAKE SUPERIOR...WHICH IS ALSO CAUSING TEMPS TO BE COOLER THAN SURROUNDING AREAS. ELSEWHERE LIGHT EASTERLY WINDS WITH TEMPS IN THE MID 30S TO NEAR 40...WARMEST ALONG THE INTERNATIONAL BORDER WHERE CLOUDS WERE MORE SCATTERED ALLOWING SUNSHINE THROUGH. CONDITIONS ARE GENERALLY VERY DRY...AND IN AREAS WHERE SUNSHINE HAS BEEN ABLE TO BREAK THROUGH THE CLOUDS IT IS UNUSUALLY DRY...WITH RELATIVE HUMIDITY 20 TO 30 PERCENT. THIS DRY AIRMASS WILL DELAY THE INITIAL ONSET ON PRECIP...AND WHILE SOME SPORADIC LIGHT RAIN/SLEET HAS BEEN REPORTED ACROSS CASS/CROW WING/AITKIN COUNTIES THIS AFTERNOON...IT HAS BEEN DRY FOR THE MOST PART DUE TO T/TD SPREADS OF 15 TO 30 DEGREES ACROSS MUCH OF NORTHEAST MINNESOTA. TONIGHT...A WINTRY MIX WILL SPREAD OVER THE REGION TONIGHT ASSOCIATED WITH A QUICK-MOVING MID-LEVEL TROUGH AXIS MOVING NORTHEAST ACROSS THE REGION TONIGHT. SOUTHERLY WINDS AT LOW/MID LEVELS /EG. 925MB TO 700MB/ WILL RESULT IN WARM AIR ADVECTION THROUGHOUT THE NIGHT...BRINGING A WARM LAYER ALOFT INTO NORTHWEST WISCONSIN AND MUCH OF NORTHEASTERN MINNESOTA ALONG/SOUTH OF HIGHWAY 2. THIS COMBINATION OF TROUGH MOVING ACROSS THE REGION AND WARM AIR ADVECTION WILL PROVIDE AMPLE LARGE-SCALE FORCING FOR PRECIPITATION ACROSS THE REGION. AS FAR AS PRECIPITATION TYPE GOES...SHORT RANGE GUIDANCE HAS BEEN TRENDING TOWARDS WEAKER WARM AIR ADVECTION...MEANING PRECIP WOULD BE MORE SNOW THAN FREEZING RAIN/SLEET. THE EXCEPTION WILL BE ACROSS FAR SOUTHERN PORTION OF THE CWA WHERE PRECIP WILL BE MORE RAIN/SLEET THAN SNOW...BUT GIVEN MODEL TRENDS WOULD NOT BE SURPRISED IF THESE LOCATIONS TOO WERE MAINLY SNOW. AS FAR AS SNOWFALL TOTALS GO...ONE TO THREE INCHES IN NORTHEAST MINNESOTA /NORTH OF HWY 2/...WITH LESS THAN AN INCH ALONG HWY 2 AND LITTLE TO NO ACCUMULATION TO THE SOUTH DUE TO RAIN MIXING IN AT TIMES. DECIDED NOT TO ISSUE A WINTER WEATHER ADVISORY AT THIS TIME MAINLY BECAUSE OF THE LIGHT PRECIP AMOUNTS. WHERE PRECIP WILL BE MAINLY SNOW /MOST OF NORTHEAST MINNESOTA/ SNOWFALL AMOUNTS WILL BE GENERALLY LESS THAN THREE INCHES...AND WHERE A MIX IS EXPECTED IT IS NOT EXPECTED TO LAST VERY LONG. IN NORTHWEST WISCONSIN SFC TEMPS WILL BE NEAR TO JUST ABOVE FREEZING...LIMITING ICE/SNOW ACCUMULATION ON ROADWAYS. HAVE DECIDED INSTEAD TO ISSUE AN SPS TO GIVE A HEADS UP FOR A SLICK COMMUTE. WEDNESDAY...MID-LEVEL DRYING BEHIND THE TROUGH WILL LEAD TO A QUICK END OF PRECIP...POSSIBLY AS DRIZZLE/FREEZING DRIZZLE...BUT LOW CLOUDS WILL STICK AROUND THROUGHOUT MOST OF THE DAY. A WEAK MID-LEVEL RIDGE MOVING ACROSS THE MIDWEST MAY LEAD TO SOME PARTIAL CLEARING...BUT GENERALLY EXPECT CLOUDY SKIES. LIGHT EASTERLY WINDS WITH NORTHEAST WINDS OVER THE LAKE...BUT MUCH LESS WINDY THAN TODAY. HIGHS IN THE LOW TO MID 40S INLAND...AND MID TO UPPER 30S NEAR LAKE SUPERIOR. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 335 PM CDT TUE APR 7 2015 THE MESSY SPRING PATTERN WILL CONTINUE THROUGHOUT THE WORK WEEK...AS THE MAIN SHORTWAVE IN THE SOUTHWEST FLOW PATTERN EJECTS INTO THE PLAINS AND THEN UPPER MIDWEST FROM WEDNESDAY NIGHT INTO THURSDAY NIGHT. THE FIRST BATCH OF WAA INDUCED PRECIPITATION WILL ARRIVE WEDNESDAY NIGHT...FOLLOWED BY PRECIPITATION FROM THE UPPER LEVEL SYSTEM INTO THURSDAY AND THURSDAY NIGHT. AS HAS BEEN THE CASE THIS WEEK...WE WILL LIKELY SEE MYRIAD OF WINTER WEATHER CONDITIONS DURING THE DIFFERENT PHASES OF THE EVOLUTION OF THIS MORE MAJOR SYSTEM. STILL NOT RULING OUT THE POTENTIAL FOR SOME SNOW ACCUMULATION WITH THE SYSTEM...ESPECIALLY ACROSS THE NORTH AND ESPECIALLY IN THE AREA OF DEFORMATION ON THE BACK SIDE OF THE DEPARTING SYSTEM. IT DOES LOOK LIKE THERE WILL BE A MIX OF RAIN...FREEZING RAIN...SLEET AND SNOW WITH MOST PLACES SEEING A FAIRLY WIDESPREAD PERIOD OF PRECIPITATION FROM WEDNESDAY NIGHT INTO THURSDAY NIGHT. SOME SCATTERED SNOW SHOWERS WILL THEN LINGER INTO FRIDAY MORNING AS THE COLD CORE MOVES ACROSS THE CWA. SHOULD BE MAINLY RAIN SHOWERS BY AFTERNOON FRIDAY. SATURDAY IS SHAPING UP TO BE A GENERALLY DRY DAY...WITH ANOTHER CHANCE OF RAIN SHOWERS MOVING BACK IN ON SUNDAY AND SUNDAY NIGHT. LOOKS LIKE DEEP MOISTURE WITH THIS SYSTEM AND WOULD NOT BE SURPRISED TO SEE A FEW THUNDERSTORMS AS WELL. HIGH TEMPERATURES WILL WARM INTO THE WEEKEND...WITH 50S AND 60S BY THE WEEKEND AND INTO EARLY IN THE WORK WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1220 AM CDT WED APR 8 2015 PRECIPITATION RANGED FROM LIGHT RAIN OVER PORTIONS OF NORTHERN WISCONSIN...TO SNOW ALONG THE INTERNATIONAL BORDER. BETWEEN THESE TWO AREAS WAS SLEET...SNOW AND FREEZING RAIN. IFR CONDITIONS WILL OCCUR IN THE HEAVIER SNOW OVER FAR NORTHERN MINNESOTA...WITH MAINLY MVFR CONDITIONS ELSEWHERE. THE PRECIPITATION WILL DIMINISH FROM THE WEST AND SOUTH LATER TONIGHT. A PERIOD OF FREEZING DRIZZLE/DRIZZLE AND FOG WILL BE POSSIBLE AS THE PRECIP EXITS THE AREA AND A MIX OF LOW MVFR/IFR CONDITIONS WILL PREVAIL INTO WEDNESDAY MORNING. THE LATEST NAM SUGGEST CEILINGS WILL RISE THROUGH THE DAY AND BECOME SCATTERED IN SPOTS. HOWEVER...THE LATEST RAP KEEPS THE CLOUDS AROUND LONGER. WE SIDED WITH THE RAP. SOME OF THE GUIDANCE SHOWS SOME FOG AND LOWER CEILINGS MOVING BACK IN WEDNESDAY EVENING...AND WE TRENDED THAT WAY. && .PRELIMINARY POINT TEMPS/POPS... DLH 32 41 30 51 / 80 70 50 20 INL 31 49 27 49 / 60 40 20 20 BRD 31 47 29 53 / 80 60 40 20 HYR 33 45 30 50 / 80 80 70 30 ASX 32 41 30 45 / 80 70 60 40 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121- 141>148. && $$ SHORT TERM...JJM LONG TERM...DAP AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1004 AM CDT Wed Apr 8 2015 .MESOSCALE DISCUSSION... Issued at 1004 AM CDT WED APR 8 2015 Convection continuing to role east across the CWA this morning along the heels of an 850-hPa low-level jet. Bulk of severe now centered well east of the KC metro and as a result...have trimmed the western two tiers of counties from Severe Thunderstorm Watch 31. Additionally...plenty of obs still reporting widespread fog across the region and have extended to inherited dense fog advisory through 11 AM. Once this morning/s activity exits to the east...eyes will quickly be drawn upstream to renewed convective development across the central Plains. Latest HRRR has convection firing over south-central KS by 20z in the form of loosely organized single cells. After developing...all models (both high-resolution convection allowing and standard operational) show convection quickly lifting northeast into the CWA by late afternoon. Right now the biggest concerns will be for locations south of Interstate 70 as these areas will likely have the best potential of seeing recovery following the passage of the warm front later this morning/early afternoon. With plenty of dynamics aloft...expect activity to quickly become severe as it moves into our area with large hail...damaging winds...and isolated tornadoes all possible. Convection later today/evening may come in a few waves as additional shortwave energy embedded with strong southwest flow aloft leads to renewed development along/near the cold front draped across south-central Kansas. In any event...will continue to monitor and update as needed. UPDATE Issued at 538 AM CDT WED APR 8 2015 Warm air wing of convection has developed more early this morning across eastern Kansas with storms quickly approaching the Missouri border at this time. Storms north of I-70 are elevated in nature and have stayed below severe warning limits, though large hail may be possible if the shear above the boundary layer inversion can organize the storms somewhat this morning. Storms farther south, generally south of a Paola Kansas to Warrensburg Missouri, Marshall and Moberly line, will have more opportunity to develop severe weather this morning. These storms will be in the vicinity of the boundary left over from last night which might help these storms get a better connection to deep layer shear and instability. Continue to think that the activity north of the Missouri River will keep the inverted surface trough anchored along our southeast border through the morning. For this reason, have added areas of fog and drizzle this morning to the western half of the forecast area. && .DISCUSSION... Issued at 403 AM CDT WED APR 8 2015 Looks like more storms are in store for eastern Kansas and Missouri today. Overnight activity took awhile Tuesday evening to get going, but once the the cap was broken there where several rather strong storms, which could have been much stronger if there had been upper level dynamics to support the storms. The difference today is that a significant trough is moving into the Plains States, which will provide any storms this afternoon or this evening with plenty of upper level support for strong robust severe thunderstorms. But, first to what will happen this morning. Today - This Morning: Early this morning an inverted surface trough remains anchored from southeast Kansas northeast through northeast Missouri, with the resulting boundary residing within the trough along our southeast county warning area border. A verity of model solutions have now coalesced on keeping this inverted surface trough in place through the morning and, possibly, through the first part of the afternoon. Additionally...it`s noted that storms are bubbling back up across east central Kansas in the elevated environment north of the trough thanks to isentropic assent on the 40 knot southwest nocturnal jet. Thoughts are that these early morning storms will likely not be severe due to their elevated nature, though marginally large hail can not be ruled out. More general thinking is that this area of storms will advect northeast into northern Missouri, staying on the cool side of the inverted trough. As a result, have added patchy fog into the northwest half few the CWA for this morning, and nudged afternoon highs near the Iowa border down a degree or two; but did up POPs for the morning, though they may need updating based on radar trends as the forecast becomes valid later this morning. Also, these morning storms could limit our instability early in the day, delaying the potential onset time for afternoon/evening activity. So, while another round of activity might wait to fire up in the late afternoon and evening hours, it is still expected to occur. Today - This Afternoon and Tonight: Expect the inverted trough to remain where it is till early afternoon when sufficient pressure falls begin across the Plains in response to the trough over the Great Basin shifting east, lifting the trough north as a warm front this afternoon. As this occurs, the environment that was rather well capped could rapidly lose that cap with any little shortwave undulation present in the flow aloft, resulting in fast development of strong and severe thunderstorms. Currently, expect storms to develop along the southern end of the inverted trough as it starts moving north this afternoon --after 20Z-- in southeast Kansas. MUCAPE values of 4000+ J/KG and 0-6KM shear of possibly 40 to 50 knots would make supercell thunderstorms possible from the first initial storms. Expect this activity to spread northeast through west central Missouri into northern Missouri during the late afternoon and evening hours Wednesday, with storms likely crossing into our area between 5 and 7 PM this evening. Uncertain as to how far into the overnight hours the strong and severe convection will last, but currently there looks to be a bit of a dry slot that works in across northwest Missouri as associated surface low lifts from Kansas into Iowa. this should bring the threat for severe storms to an end by midnight, though lingering storms could persist into Thursday. Thoughts persist that all types of severe weather may accompany our storms today, with large hail --larger than 2 inches-- strong damaging winds and isolated tornadoes possible. Thursday: The upper level trough responsible for our recent storms will be swinging past us to the north. The surface low moving into Iowa that morning will drag a Pacific cold front through the region that day. The cool air behind the front will lag far enough back to not be very notable till Friday. However, this front might be able to generate some showers and or isolated thunderstorms as it moves through, though no severe weather. Friday and through the Weekend: Cooler conditions will prevail Friday as a cool, but dry, air mass wafts through Kansas and Missouri. Temperatures will warm back into the 70s for the weekend. Saturday looks nice and dry, but by Saturday night through Sunday and into Monday a significant rain event may develop. && .AVIATION...(For the 12Z TAFS through 12Z Thursday Morning) Issued at 721 AM CDT WED APR 8 2015 Fog and thunderstorms greeted the terminals along the Kansas-Missouri border this morning. Location of a front across central Missouri indicates that the fog may linger well into the morning with easterly winds through the morning. Thunderstorm activity currently at the terminals early this morning will move east and is expected to not redevelop until this afternoon. Expect the front to lift north this afternoon allowing winds to veer to the south late this afternoon and this evening and becoming gusty as the pressure gradient tightens. Additionally, more storms are expect late this afternoon into this evening which might affect the terminals. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...DENSE FOG ADVISORY until 11 AM CDT this morning FOR KSZ025-057- 102>105. MO...DENSE FOG ADVISORY until 11 AM CDT this morning FOR MOZ020-021- 028>031-037>040-043>046. && $$ MESOSCALE DISCUSSION...32 UPDATE...Cutter DISCUSSION...Cutter AVIATION...Cutter
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
315 PM CDT WED APR 8 2015 .SHORT TERM...(TONIGHT THROUGH SATURDAY) ISSUED AT 315 PM CDT WED APR 8 2015 PRIMARY FORECAST CONCERNS ARE IN REGARDS TO CONVECTION TONIGHT AND ALSO SHOWERS ON THURSDAY. SOME STORMS DID OCCUR WITH SMALL HAIL FROM NORTH OF LINCOLN TOWARD OMAHA EARLY THIS MORNING. STORMS REALLY DID NOT GET GOING STRONG TO SEVERE UNTIL THEY WERE IN THE DMX FORECAST AREA. 500 MB CHART FROM 12Z SHOWED MAIN TROUGH STILL WELL OFF TO THE WEST. HEIGHT FALLS UP TO AROUND 100 METERS WERE BACK OVER UTAH AT 12Z...BUT AS OF EARLY AFTERNOON HAD PUSHED INTO PARTS OF WYOMING AND COLORADO. GENERALLY EXPECT PCPN TO INCREASE IN COVERAGE TONIGHT...WITH HEAVIEST PCPN AFTER ABOUT 11 PM. RECENT HRRR MODEL RUNS SUGGEST SOME STRONG STORMS MAY FORM EARLY EVENING NEAR THE MISSOURI BORDER AREA. OTHERWISE...MODELS TRENDS SHOWED LOW LEVEL JET SHOULD INCREASE WITH UP TO 50 KNOTS AT 850 MB BY LATE EVENING. THIS SHOULD HELP BRING AN INCREASE IN TSTMS OVER EASTERN NEBRASKA BY MIDNIGHT OR SO. 12Z NAM FORECAST SOUNDINGS SHOWED UP TO AROUND 2000 J/KG OR MORE OF ELEVATED CAPE AVAILABLE WITH 0-6 KM BULK SHEAR ADEQUATE FOR ROTATING ELEVATED STORMS. THESE SHOULD BRING A RISK OF HAIL MAINLY FROM 05Z TO 10Z...AND A FEW STORMS MAY BE SEVERE. THERE COULD ALSO BE SOME LOCALLY HEAVY RAIN. SHORTWAVE TO THE WEST WILL MOVE THROUGH THE AREA THURSDAY...WITH HEAVIEST RAIN AMOUNTS ACROSS THE NORTHERN PARTS OF THE FORECAST AREA NEAR DEFORMATION ZONE. WINDS WILL ALSO INCREASE AS SURFACE LOW TRACKS EAST/NORTHEAST ACROSS IOWA DURING THE DAY AND THE PRESSURE GRADIENT IN OUR AREA INCREASES. SPEEDS OF 20 TO 30 MPH WITH GUSTS AROUND 40 MPH OR MORE SHOULD BE COMMON. DROPPED FORECAST HIGHS JUST A BIT...WITH MOSTLY 50S EXPECTED THURSDAY. PCPN WILL END BY THURSDAY EVENING WITH CLOUDS DECREASING THURSDAY NIGHT. HIGH PRESSURE AT THE SURFACE BUILDS IN FOR THURSDAY NIGHT AND FRIDAY. SOUTHERLY FLOW IS FORECAST TO INCREASE FRIDAY NIGHT... MOSTLY TO OUR WEST...SO NO PCPN IS EXPECTED LOCALLY FRIDAY NIGHT. WILL INCLUDE A SLIGHT CHANCE TSTMS FOR MAINLY OUR WESTERN ZONES SATURDAY. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 315 PM CDT WED APR 8 2015 WILL NEED TO INCLUDE A CHANCE OF SHOWERS AND TSTMS FOR MUCH OF THE EXTENDED FORECAST PERIOD. HIGHEST CHANCES AND HEAVIEST AMOUNTS LIKELY AS SHORTWAVE MOVES OUT ACROSS THE CENTRAL PLAINS MONDAY NIGHT INTO TUESDAY. HIGHS SHOULD BE MOSTLY IN THE 70S THIS PERIOD...BUT SOME UPPER 60S POSSIBLE ON MONDAY. LOWS GENERALLY 40S TO LOWER 50S. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1251 PM CDT WED APR 8 2015 WIDESPREAD IFR/LIFR CONDITIONS REMAIN IN PLACE ACROSS ERN NEB THIS AFTN...AND SEE LITTLE CHANCE FOR ANY IMPROVING CONDITIONS THRU THE REMAINDER OF THE FCST PD. OTHER ISSUE TO CONTEND WITH IS POSSIBLE -TSRA ACTIVITY AT KOMA/KLNK BEGINNING LATER THIS EVENING THEN THRU EARLY THURSDAY MORNING. CONVECTION EXPECTED TO DEVELOP ALONG A FRONTAL BNDRY OVER ERN KS...THE GRADUALLY LIFT INTO ERN NEB DURING THE EVENING HOURS. THE -TSRA THOUGH MAY BE ISOLATED IN NATURE SO OPTED TO JUST GO WITH PROB30 GROUPS FOR NOW. ALSO...CANNOT DISCOUNT THAT A FEW STORMS MAY PRODUCE NEAR SEVERE HAIL THIS EVENING. COLD FRONT RUSHES IN THEN LATE THURSDAY MORNING WITH WIND SHIFT TO THE NW AT ALL TERMINALS. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER LONG TERM...MILLER AVIATION...DEE
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
103 PM CDT WED APR 8 2015 .SYNOPSIS... ISSUED AT 342 AM CDT WED APR 8 2015 H5 ANALYSIS FROM EARLIER THIS EVENING HAD A CLOSED LOW OVER NRN CALIFORNIA WITH A TROUGH OF LOW PRESSURE EXTENDING SWD INTO SO CALIFORNIA. SWLY FLOW ALOFT EXTENDED FROM THE SWRN CONUS NEWD INTO THE ROCKIES AND PLAINS STATES. WV IMAGERY TONIGHT HAS THE BULK OF MID AND UPPER LEVEL MOISTURE WITH THIS FEATURE ACROSS MEXICO AND TEXAS. FURTHER NORTH...MAINLY DRY MID AND UPPER LEVELS WERE NOTED...HOWEVER A SMALL DISTURBANCE...HAS SPREAD MID LEVEL CLOUDS AND SHOWERS TO THE NORTHWESTERN CWA TONIGHT...WITH AN OCCASIONAL LIGHTNING STRIKE NOTED. FOR THE REMAINDER OF THE FORECAST AREA...A MOIST BOUNDARY LAYER AND EASTERLY WINDS...HAS LED TO ANOTHER NIGHT OF LOW CLOUDS...FOG AND DRIZZLE. AT THE SURFACE...A STATIONARY FRONT EXTENDED FROM AROUND COLORADO SPRINGS...SEWD TO THE KS/OK BORDER. NORTH OF THE FRONT...EASTERLY WINDS AND MOSTLY CLOUDY SKIES WERE PRESENT ACROSS ALL OF WESTERN AND NORTH CENTRAL NEBRASKA. AS OF 3 AM CDT...TEMPERATURES RANGED FROM 39 AT VALENTINE AND AINSWORTH TO 43 AT IMPERIAL AND OGALLALA. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 342 AM CDT WED APR 8 2015 THE MAIN FORECAST CHALLENGE OVER THE NEXT TWO PERIODS IS PRECIPITATION CHANCES AND PRECIPITATION TYPES OVERNIGHT TONIGHT. FOR TODAY...EASTERLY WINDS WILL CONTINUE TO FAVOR LOW CLOUDS FOR MOST OF THE FORECAST AREA. SOME CLEARING IS POSSIBLE IN THE PANHANDLE ZONES AND ACROSS FAR SWRN PORTIONS OF THE CWA THIS AFTERNOON...PER HRRR AND NAM12 H85 AND H85-H90 RH FIELDS. WITH THIS IN MIND...FILTERED SUN WILL LEAD TO HIGHS IN THE UPPER 50S. ELSEWHERE...HIGHS WILL RANGE FROM THE UPPER 40S TO LOWER 50S. LATE THIS AFTERNOON AS THE UPPER LEVEL LOW PUSHES EAST INTO WESTERN WYOMING...NRN UT AND NWRN COLORADO ELEVATED AND SURFACE BASED INSTABILITY WILL BEGIN TO INCREASE ACROSS THE PANHANDLE. THE LATEST NAM12 IS INDICATIVE OF NEGATIVE LI`S ACROSS THE PANHANDLE FROM 21Z THROUGH 03Z AND ACROSS PORTIONS OF SWRN NEBRASKA WITH ELEVATED INSTABILITY FROM 00Z THROUGH 06Z THIS EVENING. DID GO AHEAD AND INTRODUCE THUNDERSTORMS TO THE FORECAST IN THE FAR WEST AND SWRN CWA FOR LATE THIS AFTERNOON AND EVENING IN LIGHT OF THE NEGATIVE LI/S. AS FOR PCPN CHANCES...THE HIGHEST POPS WILL CONTINUE IN THE WEST AND NORTHWEST...TRANSITIONING ACROSS THE SANDHILLS AND NORTH CENTRAL NEBRASKA OVERNIGHT. THESE AREAS ARE IN THE MOST FAVORABLE AREAS FOR ISENTROPIC LIFT AHEAD OF THE APPG TROUGH THIS EVENING...THEN IN THE WRAP AROUND OVERNIGHT. AS FOR PRECIPITATION TYPE OVERNIGHT...DECIDED TO KEEP THE BULK OF PCPN AS ALL RAIN AS BUFKIT SOUNDINGS INDICATE ONLY A 1 TO 2 HOUR WINDOW FOR CHANGEOVER TO SNOW...AND THIS IS MAINLY THURSDAY MORNING ACROSS THE FAR NORTHWESTERN AND NORTHERN CWA. DECIDED TO WORD THE FCST AS RAIN OR SNOW...AS LOWS ARE ONLY EXPECTED TO DROP INTO 33 TO 35 DEGREE RANGE IN THE NORTHWEST OVERNIGHT. AS FOR SNOW ACCUMS...DECIDED TO KEEP THESE AT A MINIMUM AS IT IS EXPECTED TO MIX WITH RAIN...AND WARM GROUND CONDS SHOULD LIMIT ANY ACCUMS IF THEY DO OCCUR. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 342 AM CDT WED APR 8 2015 UPPER LEVEL TROUGH AND ASSOCIATED COLD POOL WILL WORK EAST ACROSS THE FORECAST AREA ON THURSDAY. PRECIPITATION IS EXPECTED TO CONTINUE THROUGH MUCH OF THE MORNING HOURS...BUT BEGIN TO WANE IN THE AFTERNOON AS SYSTEM RELATIVE UPGLIDE ASSOCIATED WITH A FRONTAL BOUNDARY SHIFTS SOUTH AND EAST. IN ADDITION...LARGE SCALE LIFT DECREASES AS THE TROUGH AXIS WORKS INTO EASTERN IOWA BY MID AFTERNOON. PRECIPITATION AMOUNTS ARE ANTICIPATED TO BE LIGHT DURING THE DAYLIGHT HOURS. MOST LOCATIONS WILL ONLY ACCUMULATE A FEW ADDITIONAL TENTHS AT MOST. WHAT CONTINUES TO BE THE GREATEST ENIGMA WITH THIS SYSTEM IS WHEN AND IF A CHANGE OVER TO SNOW WERE TO OCCUR. ENOUGH MID AND UPPER LEVEL COOLING WILL HELP WITH THE CHANGE OVER...ESPECIALLY SINCE H85-H9 TEMPERATURES FALL BELOW 0C AFTER 12Z ACROSS OUR NORTHWEST THURSDAY MORNING. WOULD EXPECT THAT THE FROZEN HYDROMETEOR WOULD MAKE IT TO THE SURFACE...BUT SFC T/S ARE SHOWN LARGELY TO REMAIN JUST ABOVE 0C. CURRENT THINKING IS THAT A CHANGE OVER WILL OCCUR...AFTER SUNRISE THURSDAY...BUT THEN QUICKLY CHANGE BACK TO ALL RAIN AS THE DIURNAL HEATING TAKES CONTROL. WHERE THERE IS ENHANCEMENT OF QPF FALLING AS SNOW...SOME ACCUMULATION MAY OCCUR FOR AN HOUR OR TWO PERIOD. HOWEVER WITH THE RECENT WARM SPELL GROUND TEMPERATURES WOULD SUPPORT MELTING...THUS ACCUMULATIONS WOULD BE INSIGNIFICANT...A COUPLE TENTHS AT MOST. NORTHWEST FLOW WILL TRANSPORT COOLER AIR INTO THE REGION OVERNIGHT...WITH MORNING LOWS BELOW 0C FOR THE ENTIRE CWA FRIDAY MORNING. RETURN FLOW AND TRANSITORY UPPER RIDGING WILL PROMOTE A QUICK WARM-UP ON FRIDAY. HIGHS WILL CLIMB BACK INTO THE 60S. THE RETURN FLOW WILL ALLOW FOR AN INCREASE IN MOISTURE ACROSS THE HIGH PLAINS AND WEST CENTRAL NEBRASKA. A THETA-E GRADIENT NOSES INTO THE FORECAST AREA EARLY SATURDAY. ELEVATED INSTABILITY DEVELOPS ALONG THE GRADIENT...WITH LI/S APPROACHING -5C BY SATURDAY AFTERNOON. A FEW ELEVATED STORMS ARE POSSIBLE. SUNDAY...A SIMILAR SETUP IS IN PLACE HOWEVER THE MODELS SHOW A COLD FRONT ADVANCING ACROSS THE CWA EARLY AFTERNOON. MODEL CONSISTENCY IS NOT TOO STRONG AT THIS POINT...BUT SUFFICIENT ENOUGH FOR A MENTION OF THUNDERS ONCE AGAIN ESPECIALLY ALONG AND SOUTH OF THE FRONT. WILL NEED TO WATCH AS PRE-FRONTAL CONDITIONS WOULD HAVE SLIGHTLY MORE ENERGY TO WORK WITH. THE PATTERN REMAINS ACTIVE EARLY NEXT WEEK...AND WILL HAVE TO WATCH THE PROGRESSION OF A SOUTHERN STREAM CLOSED LOW...WHICH MAY BRING ADDITIONAL CHANCES OF QPF TO THE REGION. THE INIT GAVE US SLIGHT CHANCES...WHICH IS REASONABLE GIVEN A LACK OF CONSISTENCY IN THE LONG RANGE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1233 PM CDT WED APR 8 2015 WIDESPREAD LOW CLOUDS AND IFR/MVFR CONDITIONS WILL PERSIST THROUGH TONIGHT ACROSS WESTERN AND NORTH CENTRAL NEBRASKA. CEILINGS MAY TEMPORARILY LIFT ACROSS PORTIONS OF SOUTHWEST NEBRASKA THIS AFTERNOON...BUT LOWER ONCE AGAIN TONIGHT. AREAS OF FOG AND DRIZZLE ARE ALSO POSSIBLE. AS A POTENT UPPER LEVEL DISTURBANCE AND ASSOCIATED STRONG SURFACE LOW MOVE INTO THE AREA...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP THIS EVENING. THE SHOWERS WILL TRANSITION TO MORE OF A STEADY RAIN AFTER MIDNIGHT TONIGHT...POSSIBLY MIXING WITH WET SNOW ACROSS NORTHWEST AND PORTIONS OF NORTH CENTRAL NEBRASKA. THE PRECIPITATION SHOULD BE ENDING BY NOON TIME THURSDAY WITH OVERALL CONDITIONS IMPROVING. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...CLB LONG TERM...JACOBS AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
645 AM CDT WED APR 8 2015 .SYNOPSIS... ISSUED AT 342 AM CDT WED APR 8 2015 H5 ANALYSIS FROM EARLIER THIS EVENING HAD A CLOSED LOW OVER NRN CALIFORNIA WITH A TROUGH OF LOW PRESSURE EXTENDING SWD INTO SO CALIFORNIA. SWLY FLOW ALOFT EXTENDED FROM THE SWRN CONUS NEWD INTO THE ROCKIES AND PLAINS STATES. WV IMAGERY TONIGHT HAS THE BULK OF MID AND UPPER LEVEL MOISTURE WITH THIS FEATURE ACROSS MEXICO AND TEXAS. FURTHER NORTH...MAINLY DRY MID AND UPPER LEVELS WERE NOTED...HOWEVER A SMALL DISTURBANCE...HAS SPREAD MID LEVEL CLOUDS AND SHOWERS TO THE NORTHWESTERN CWA TONIGHT...WITH AN OCCASIONAL LIGHTNING STRIKE NOTED. FOR THE REMAINDER OF THE FORECAST AREA...A MOIST BOUNDARY LAYER AND EASTERLY WINDS...HAS LED TO ANOTHER NIGHT OF LOW CLOUDS...FOG AND DRIZZLE. AT THE SURFACE...A STATIONARY FRONT EXTENDED FROM AROUND COLORADO SPRINGS...SEWD TO THE KS/OK BORDER. NORTH OF THE FRONT...EASTERLY WINDS AND MOSTLY CLOUDY SKIES WERE PRESENT ACROSS ALL OF WESTERN AND NORTH CENTRAL NEBRASKA. AS OF 3 AM CDT...TEMPERATURES RANGED FROM 39 AT VALENTINE AND AINSWORTH TO 43 AT IMPERIAL AND OGALLALA. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 342 AM CDT WED APR 8 2015 THE MAIN FORECAST CHALLENGE OVER THE NEXT TWO PERIODS IS PRECIPITATION CHANCES AND PRECIPITATION TYPES OVERNIGHT TONIGHT. FOR TODAY...EASTERLY WINDS WILL CONTINUE TO FAVOR LOW CLOUDS FOR MOST OF THE FORECAST AREA. SOME CLEARING IS POSSIBLE IN THE PANHANDLE ZONES AND ACROSS FAR SWRN PORTIONS OF THE CWA THIS AFTERNOON...PER HRRR AND NAM12 H85 AND H85-H90 RH FIELDS. WITH THIS IN MIND...FILTERED SUN WILL LEAD TO HIGHS IN THE UPPER 50S. ELSEWHERE...HIGHS WILL RANGE FROM THE UPPER 40S TO LOWER 50S. LATE THIS AFTERNOON AS THE UPPER LEVEL LOW PUSHES EAST INTO WESTERN WYOMING...NRN UT AND NWRN COLORADO ELEVATED AND SURFACE BASED INSTABILITY WILL BEGIN TO INCREASE ACROSS THE PANHANDLE. THE LATEST NAM12 IS INDICATIVE OF NEGATIVE LI`S ACROSS THE PANHANDLE FROM 21Z THROUGH 03Z AND ACROSS PORTIONS OF SWRN NEBRASKA WITH ELEVATED INSTABILITY FROM 00Z THROUGH 06Z THIS EVENING. DID GO AHEAD AND INTRODUCE THUNDERSTORMS TO THE FORECAST IN THE FAR WEST AND SWRN CWA FOR LATE THIS AFTERNOON AND EVENING IN LIGHT OF THE NEGATIVE LI/S. AS FOR PCPN CHANCES...THE HIGHEST POPS WILL CONTINUE IN THE WEST AND NORTHWEST...TRANSITIONING ACROSS THE SANDHILLS AND NORTH CENTRAL NEBRASKA OVERNIGHT. THESE AREAS ARE IN THE MOST FAVORABLE AREAS FOR ISENTROPIC LIFT AHEAD OF THE APPG TROUGH THIS EVENING...THEN IN THE WRAP AROUND OVERNIGHT. AS FOR PRECIPITATION TYPE OVERNIGHT...DECIDED TO KEEP THE BULK OF PCPN AS ALL RAIN AS BUFKIT SOUNDINGS INDICATE ONLY A 1 TO 2 HOUR WINDOW FOR CHANGEOVER TO SNOW...AND THIS IS MAINLY THURSDAY MORNING ACROSS THE FAR NORTHWESTERN AND NORTHERN CWA. DECIDED TO WORD THE FCST AS RAIN OR SNOW...AS LOWS ARE ONLY EXPECTED TO DROP INTO 33 TO 35 DEGREE RANGE IN THE NORTHWEST OVERNIGHT. AS FOR SNOW ACCUMS...DECIDED TO KEEP THESE AT A MINIMUM AS IT IS EXPECTED TO MIX WITH RAIN...AND WARM GROUND CONDS SHOULD LIMIT ANY ACCUMS IF THEY DO OCCUR. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 342 AM CDT WED APR 8 2015 UPPER LEVEL TROUGH AND ASSOCIATED COLD POOL WILL WORK EAST ACROSS THE FORECAST AREA ON THURSDAY. PRECIPITATION IS EXPECTED TO CONTINUE THROUGH MUCH OF THE MORNING HOURS...BUT BEGIN TO WANE IN THE AFTERNOON AS SYSTEM RELATIVE UPGLIDE ASSOCIATED WITH A FRONTAL BOUNDARY SHIFTS SOUTH AND EAST. IN ADDITION...LARGE SCALE LIFT DECREASES AS THE TROUGH AXIS WORKS INTO EASTERN IOWA BY MID AFTERNOON. PRECIPITATION AMOUNTS ARE ANTICIPATED TO BE LIGHT DURING THE DAYLIGHT HOURS. MOST LOCATIONS WILL ONLY ACCUMULATE A FEW ADDITIONAL TENTHS AT MOST. WHAT CONTINUES TO BE THE GREATEST ENIGMA WITH THIS SYSTEM IS WHEN AND IF A CHANGE OVER TO SNOW WERE TO OCCUR. ENOUGH MID AND UPPER LEVEL COOLING WILL HELP WITH THE CHANGE OVER...ESPECIALLY SINCE H85-H9 TEMPERATURES FALL BELOW 0C AFTER 12Z ACROSS OUR NORTHWEST THURSDAY MORNING. WOULD EXPECT THAT THE FROZEN HYDROMETEOR WOULD MAKE IT TO THE SURFACE...BUT SFC T/S ARE SHOWN LARGELY TO REMAIN JUST ABOVE 0C. CURRENT THINKING IS THAT A CHANGE OVER WILL OCCUR...AFTER SUNRISE THURSDAY...BUT THEN QUICKLY CHANGE BACK TO ALL RAIN AS THE DIURNAL HEATING TAKES CONTROL. WHERE THERE IS ENHANCEMENT OF QPF FALLING AS SNOW...SOME ACCUMULATION MAY OCCUR FOR AN HOUR OR TWO PERIOD. HOWEVER WITH THE RECENT WARM SPELL GROUND TEMPERATURES WOULD SUPPORT MELTING...THUS ACCUMULATIONS WOULD BE INSIGNIFICANT...A COUPLE TENTHS AT MOST. NORTHWEST FLOW WILL TRANSPORT COOLER AIR INTO THE REGION OVERNIGHT...WITH MORNING LOWS BELOW 0C FOR THE ENTIRE CWA FRIDAY MORNING. RETURN FLOW AND TRANSITORY UPPER RIDGING WILL PROMOTE A QUICK WARM-UP ON FRIDAY. HIGHS WILL CLIMB BACK INTO THE 60S. THE RETURN FLOW WILL ALLOW FOR AN INCREASE IN MOISTURE ACROSS THE HIGH PLAINS AND WEST CENTRAL NEBRASKA. A THETA-E GRADIENT NOSES INTO THE FORECAST AREA EARLY SATURDAY. ELEVATED INSTABILITY DEVELOPS ALONG THE GRADIENT...WITH LI/S APPROACHING -5C BY SATURDAY AFTERNOON. A FEW ELEVATED STORMS ARE POSSIBLE. SUNDAY...A SIMILAR SETUP IS IN PLACE HOWEVER THE MODELS SHOW A COLD FRONT ADVANCING ACROSS THE CWA EARLY AFTERNOON. MODEL CONSISTENCY IS NOT TOO STRONG AT THIS POINT...BUT SUFFICIENT ENOUGH FOR A MENTION OF THUNDERS ONCE AGAIN ESPECIALLY ALONG AND SOUTH OF THE FRONT. WILL NEED TO WATCH AS PRE-FRONTAL CONDITIONS WOULD HAVE SLIGHTLY MORE ENERGY TO WORK WITH. THE PATTERN REMAINS ACTIVE EARLY NEXT WEEK...AND WILL HAVE TO WATCH THE PROGRESSION OF A SOUTHERN STREAM CLOSED LOW...WHICH MAY BRING ADDITIONAL CHANCES OF QPF TO THE REGION. THE INIT GAVE US SLIGHT CHANCES...WHICH IS REASONABLE GIVEN A LACK OF CONSISTENCY IN THE LONG RANGE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 645 AM CDT WED APR 8 2015 AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL SPREAD ABUNDANT CLOUDS AND THE THREAT FOR RAIN AND CONTINUED LOW CIGS ACROSS WESTERN AND NORTH CENTRAL NEBRASKA OVER THE NEXT 24 HOURS. FOR THE KLBF TERMINAL...LIFR CIGS UNDER 1000 FT AGL WILL CONTINUE THROUGH MID MORNING...WITH MVFR CIGS OF 1200 TO 1800 FT AGL AFTER 15Z. SOME LIMITED CLEARING WILL BE POSSIBLE AT THE KLBF TERMINAL LATER THIS AFTERNOON WITH OVERCAST SKIES EXPECTED AFTER 01Z THURSDAY. LIGHT RAIN WILL BE POSSIBLE AFTER THE LATE EVENING HOURS...WITH CIGS DROPPING DOWN TO UNDER 1000 FT AGL OVERNIGHT. FOR THE KVTN TERMINAL...EXPECT LIFR CIGS UNDER 1000 FT AGL THIS MORNING. MVFR CIGS OF 1500 FT AGL ARE EXPECTED THIS AFTERNOON. FOR TONIGHT...CIGS WILL LOWER TO UNDER 1000 FT AGL WITH RAIN EXPECTED AFTER 04Z THURSDAY. PERIODIC VISIBILITIES DOWN TO 4SM ARE POSSIBLE AS WELL. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...CLB LONG TERM...JACOBS AVIATION...CLB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
342 AM CDT WED APR 8 2015 .SYNOPSIS... ISSUED AT 342 AM CDT WED APR 8 2015 H5 ANALYSIS FROM EARLIER THIS EVENING HAD A CLOSED LOW OVER NRN CALIFORNIA WITH A TROUGH OF LOW PRESSURE EXTENDING SWD INTO SO CALIFORNIA. SWLY FLOW ALOFT EXTENDED FROM THE SWRN CONUS NEWD INTO THE ROCKIES AND PLAINS STATES. WV IMAGERY TONIGHT HAS THE BULK OF MID AND UPPER LEVEL MOISTURE WITH THIS FEATURE ACROSS MEXICO AND TEXAS. FURTHER NORTH...MAINLY DRY MID AND UPPER LEVELS WERE NOTED...HOWEVER A SMALL DISTURBANCE...HAS SPREAD MID LEVEL CLOUDS AND SHOWERS TO THE NORTHWESTERN CWA TONIGHT...WITH AN OCCASIONAL LIGHTNING STRIKE NOTED. FOR THE REMAINDER OF THE FORECAST AREA...A MOIST BOUNDARY LAYER AND EASTERLY WINDS...HAS LED TO ANOTHER NIGHT OF LOW CLOUDS...FOG AND DRIZZLE. AT THE SURFACE...A STATIONARY FRONT EXTENDED FROM AROUND COLORADO SPRINGS...SEWD TO THE KS/OK BORDER. NORTH OF THE FRONT...EASTERLY WINDS AND MOSTLY CLOUDY SKIES WERE PRESENT ACROSS ALL OF WESTERN AND NORTH CENTRAL NEBRASKA. AS OF 3 AM CDT...TEMPERATURES RANGED FROM 39 AT VALENTINE AND AINSWORTH TO 43 AT IMPERIAL AND OGALLALA. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 342 AM CDT WED APR 8 2015 THE MAIN FORECAST CHALLENGE OVER THE NEXT TWO PERIODS IS PRECIPITATION CHANCES AND PRECIPITATION TYPES OVERNIGHT TONIGHT. FOR TODAY...EASTERLY WINDS WILL CONTINUE TO FAVOR LOW CLOUDS FOR MOST OF THE FORECAST AREA. SOME CLEARING IS POSSIBLE IN THE PANHANDLE ZONES AND ACROSS FAR SWRN PORTIONS OF THE CWA THIS AFTERNOON...PER HRRR AND NAM12 H85 AND H85-H90 RH FIELDS. WITH THIS IN MIND...FILTERED SUN WILL LEAD TO HIGHS IN THE UPPER 50S. ELSEWHERE...HIGHS WILL RANGE FROM THE UPPER 40S TO LOWER 50S. LATE THIS AFTERNOON AS THE UPPER LEVEL LOW PUSHES EAST INTO WESTERN WYOMING...NRN UT AND NWRN COLORADO ELEVATED AND SURFACE BASED INSTABILITY WILL BEGIN TO INCREASE ACROSS THE PANHANDLE. THE LATEST NAM12 IS INDICATIVE OF NEGATIVE LI`S ACROSS THE PANHANDLE FROM 21Z THROUGH 03Z AND ACROSS PORTIONS OF SWRN NEBRASKA WITH ELEVATED INSTABILITY FROM 00Z THROUGH 06Z THIS EVENING. DID GO AHEAD AND INTRODUCE THUNDERSTORMS TO THE FORECAST IN THE FAR WEST AND SWRN CWA FOR LATE THIS AFTERNOON AND EVENING IN LIGHT OF THE NEGATIVE LI/S. AS FOR PCPN CHANCES...THE HIGHEST POPS WILL CONTINUE IN THE WEST AND NORTHWEST...TRANSITIONING ACROSS THE SANDHILLS AND NORTH CENTRAL NEBRASKA OVERNIGHT. THESE AREAS ARE IN THE MOST FAVORABLE AREAS FOR ISENTROPIC LIFT AHEAD OF THE APPG TROUGH THIS EVENING...THEN IN THE WRAP AROUND OVERNIGHT. AS FOR PRECIPITATION TYPE OVERNIGHT...DECIDED TO KEEP THE BULK OF PCPN AS ALL RAIN AS BUFKIT SOUNDINGS INDICATE ONLY A 1 TO 2 HOUR WINDOW FOR CHANGEOVER TO SNOW...AND THIS IS MAINLY THURSDAY MORNING ACROSS THE FAR NORTHWESTERN AND NORTHERN CWA. DECIDED TO WORD THE FCST AS RAIN OR SNOW...AS LOWS ARE ONLY EXPECTED TO DROP INTO 33 TO 35 DEGREE RANGE IN THE NORTHWEST OVERNIGHT. AS FOR SNOW ACCUMS...DECIDED TO KEEP THESE AT A MINIMUM AS IT IS EXPECTED TO MIX WITH RAIN...AND WARM GROUND CONDS SHOULD LIMIT ANY ACCUMS IF THEY DO OCCUR. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 342 AM CDT WED APR 8 2015 UPPER LEVEL TROUGH AND ASSOCIATED COLD POOL WILL WORK EAST ACROSS THE FORECAST AREA ON THURSDAY. PRECIPITATION IS EXPECTED TO CONTINUE THROUGH MUCH OF THE MORNING HOURS...BUT BEGIN TO WANE IN THE AFTERNOON AS SYSTEM RELATIVE UPGLIDE ASSOCIATED WITH A FRONTAL BOUNDARY SHIFTS SOUTH AND EAST. IN ADDITION...LARGE SCALE LIFT DECREASES AS THE TROUGH AXIS WORKS INTO EASTERN IOWA BY MID AFTERNOON. PRECIPITATION AMOUNTS ARE ANTICIPATED TO BE LIGHT DURING THE DAYLIGHT HOURS. MOST LOCATIONS WILL ONLY ACCUMULATE A FEW ADDITIONAL TENTHS AT MOST. WHAT CONTINUES TO BE THE GREATEST ENIGMA WITH THIS SYSTEM IS WHEN AND IF A CHANGE OVER TO SNOW WERE TO OCCUR. ENOUGH MID AND UPPER LEVEL COOLING WILL HELP WITH THE CHANGE OVER...ESPECIALLY SINCE H85-H9 TEMPERATURES FALL BELOW 0C AFTER 12Z ACROSS OUR NORTHWEST THURSDAY MORNING. WOULD EXPECT THAT THE FROZEN HYDROMETEOR WOULD MAKE IT TO THE SURFACE...BUT SFC T/S ARE SHOWN LARGELY TO REMAIN JUST ABOVE 0C. CURRENT THINKING IS THAT A CHANGE OVER WILL OCCUR...AFTER SUNRISE THURSDAY...BUT THEN QUICKLY CHANGE BACK TO ALL RAIN AS THE DIURNAL HEATING TAKES CONTROL. WHERE THERE IS ENHANCEMENT OF QPF FALLING AS SNOW...SOME ACCUMULATION MAY OCCUR FOR AN HOUR OR TWO PERIOD. HOWEVER WITH THE RECENT WARM SPELL GROUND TEMPERATURES WOULD SUPPORT MELTING...THUS ACCUMULATIONS WOULD BE INSIGNIFICANT...A COUPLE TENTHS AT MOST. NORTHWEST FLOW WILL TRANSPORT COOLER AIR INTO THE REGION OVERNIGHT...WITH MORNING LOWS BELOW 0C FOR THE ENTIRE CWA FRIDAY MORNING. RETURN FLOW AND TRANSITORY UPPER RIDGING WILL PROMOTE A QUICK WARM-UP ON FRIDAY. HIGHS WILL CLIMB BACK INTO THE 60S. THE RETURN FLOW WILL ALLOW FOR AN INCREASE IN MOISTURE ACROSS THE HIGH PLAINS AND WEST CENTRAL NEBRASKA. A THETA-E GRADIENT NOSES INTO THE FORECAST AREA EARLY SATURDAY. ELEVATED INSTABILITY DEVELOPS ALONG THE GRADIENT...WITH LI/S APPROACHING -5C BY SATURDAY AFTERNOON. A FEW ELEVATED STORMS ARE POSSIBLE. SUNDAY...A SIMILAR SETUP IS IN PLACE HOWEVER THE MODELS SHOW A COLD FRONT ADVANCING ACROSS THE CWA EARLY AFTERNOON. MODEL CONSISTENCY IS NOT TOO STRONG AT THIS POINT...BUT SUFFICIENT ENOUGH FOR A MENTION OF THUNDERS ONCE AGAIN ESPECIALLY ALONG AND SOUTH OF THE FRONT. WILL NEED TO WATCH AS PRE-FRONTAL CONDITIONS WOULD HAVE SLIGHTLY MORE ENERGY TO WORK WITH. THE PATTERN REMAINS ACTIVE EARLY NEXT WEEK...AND WILL HAVE TO WATCH THE PROGRESSION OF A SOUTHERN STREAM CLOSED LOW...WHICH MAY BRING ADDITIONAL CHANCES OF QPF TO THE REGION. THE INIT GAVE US SLIGHT CHANCES...WHICH IS REASONABLE GIVEN A LACK OF CONSISTENCY IN THE LONG RANGE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1135 PM CDT TUE APR 7 2015 LIFR CEILINGS CONTINUE FROM KVTN AND KBBW AND AREAS TO THE EAST. IFR CEILINGS AT KLBF ARE FORECAST TO BECOME LIFR AT 3SM -DZ BR OVC004 FROM 08Z-16Z...THEN P6SM OVC007 TIL 18Z. AFTER 18Z MVFR CEILINGS ARE EXPECTED. AT KVTN...LIFR CEILINGS NEAR 2SM -DZ BR OVC002 UNTIL 18Z...THEN MVFR FOR REMAINDER OF PERIOD. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...CLB LONG TERM...JACOBS AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
204 AM EDT WED APR 8 2015 .SYNOPSIS... A FRONTAL BOUNDARY STALLED FROM THE OHIO VALLEY TO THE MID ATLANTIC COAST WILL PROVIDE PERIODS OF UNSETTLED WEATHER AROUND THE REGION THROUGH THURSDAY. TEMPERATURES WILL GENERALLY SUPPORT RAIN DURING THE DAYLIGHT HOURS...BUT MAY TAIL OFF TO BELOW FREEZING AT NIGHT...PROVIDING A CHANCE FOR SOME LIGHT FREEZING RAIN OR SLEET BOTH LATE TONIGHT AND AGAIN LATE WEDNESDAY NIGHT FOR THE MOHAWK VALLEY...WESTERN CATSKILLS AND NORTHERN POCONOS. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 950 PM UPDATE... LATEST HRRR GUIDANCE FORECASTS THE NEXT SHORT WAVE / IMPULSE INVOF OF ELEVATED WARM FRONT TO PUSH PRECIP INTO WESTERN FA AROUND 6Z. THE PRECIPITATION WILL GRADUALLY SPREAD NORTH AND EAST THROUGHOUT THE PREDAWN HOURS UNTIL RAIN SHOWERS COVER THE ENTIRE REGION FOR THE MID-MORNING COMMUTE. A VERY SLIGHT POSSIBILITY EXISTS FOR SLEET OR FREEZING RAIN OVER THE NORTHERN FA, WHERE COLD AIR BLEEDS OFF OF THE HIGHER TERRAIN. POPS ARE VERY LOW (MAINLY SLIGHT CHANCE TO LOW CHANCE) DURING THE PERIOD OF THE MORNING WHEN TEMPS ARE MARGINAL, SO WILL KEEP THE THREAT MINIMIZED. SEE NO NEED TO RAISE A FLAG FOR SUCH A LOW PERCENTAGE EVENT. 4 PM UPDATE... FAST ZONAL FLOW ALOFT WITH MINOR IMPULSES MOVING ALONG AN 850-700 MB WARM FRONT OVER THE REGION WILL PROVIDE THE NECESSARY FORCING FOR PERIODIC BOUTS OF PRECIPITATION THROUGH THURSDAY. TIMING IS DIFFICULT IN THIS TYPE OF PATTERN TO GET A HANDLE ON EXACTLY WHEN AND WHERE IT WILL HAPPEN...BUT 12Z MODELS ARE SHOWING A LULL IN ACTION AS THIS FIRST WAVE DEPARTS THIS EVENING...FOLLOWED BY A RESURGENCE OF ENERGY AFTER MIDNIGHT AFFECTING MAINLY OUR SW ZONES...THEN THE NEPA AND WRN CATSKILLS SHORTLY AFTER DAYBREAK. COLDER AND SLIGHTLY DRIER AIRMASS UNDER HIGH PRESSURE OVER NRN NEW YORK WILL ALLOW FOR OUR NORTHERN AND EASTERN ZONES TO DROP TO NEAR AND BELOW FREEZING BEFORE PRECIP STARTS. EARLIER FORECASTS HAD MENTION OF FREEZING RAIN/SLEET FOR THE MOHAWK VALLEY AND WRN CATS LATE TONIGHT AND EARLY WEDNESDAY BEFORE WARMING. 12Z FORECAST SOUNDINGS AND GENERAL THICKNESS FIELDS MAINTAIN THIS IDEA. NO WINTER HEADLINES AT THIS TIME AS THE POPS ARE STILL UNCERTAIN AS TO THIS HAPPENING BEFORE TEMPS WARM...AND TEMPS ARE RIGHT ON THE FREEZING LINE ANYWAY. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/... TIMING CONTINUES TO BE PROBLEMATIC IN THIS FAST PATTERN THROUGH THURSDAY...HOWEVER THE 12Z GUIDANCE IS IN FAIR AGREEMENT ON A COUPLE OF KEY PERIODS WHERE MOST OF OUR FORECAST AREA SHOULD SEE PRECIP. A SURGE ALONG THE WARM FRONT ALOFT OCCURS WEDNESDAY MORNING...FOLLOWED BY ANOTHER LULL WEDNESDAY NIGHT AND THURSDAY MORNING. GREATER AMPLIFICATION OF THE PATTERN THEN TAKES PLACE WITH A DEEPER BOUNDARY LAYER FLOW INCREASING ON THURSDAY AFTERNOON WITH ADDITIONAL PERIODS OF RAIN SWEEPING INTO THE AREA. WE CONTINUE TO SEE SIGNS OF CLASSIC COLD AIR DAMMING ALONG OUR EASTERN ZONES AGAIN WEDNESDAY THROUGH THURSDAY WITH TEMPERATURES STRUGGLING TO GET OUT OF THE UPPER 30S TOMORROW FROM THE CATSKILLS TO THE NRN POCONOS. THIS WILL AGAIN SET THE STAGE FOR TEMPERATURES TO SLIP BELOW FREEZING IN THESE AREAS AS SOME LINGERING PRECIPITATION WORKS IN AGAIN LATER WEDNESDAY NIGHT AND EARLY THURSDAY FOR ANOTHER POTENTIAL ROUND OF FREEZING RAIN OR SLEET. WHEN ALL IS SAID AND DONE THURSDAY AFTERNOON...THERE COULD BE QUITE A TEMPERATURE GRADIENT FROM THE FINGER LAKES TO THE POCONOS RANGING FROM THE 50S TO THE UPPER 30S. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... 3 PM UPDATE... THE UNSETTLED PATTERN WILL CONTINUE THROUGH THE FIRST PART OF THE EXTENDED WITH FAIR WEATHER TO FOLLOW FOR THE WEEKEND. EXPECT SHOWERS THURSDAY NIGHT ALONG AND AHEAD OF A WARM FRONT WITH TEMPS NUDGING UP OVERNIGHT. WE ALSO CONTINUE TO MENTION THE SLIGHT CHANCE OF ELEVATED CONVECTION OVER WESTERN ZONES. FOR FRIDAY, STILL EXPECTING THE AREA TO BRIEFLY BREAK INTO THE WARM SECTOR BEFORE A COLD FRONT MOVES THROUGH IN THE AFTERNOON. SHOWALTER INDICES AND/OR LIFTED INDICES GET NEAR OR SLIGHTLY BELOW ZERO. PRECIPITABLE WATER VALUES GET PAST 1.25 INCHES.. CAPE ITSELF WILL BE VERY LIMITED...WHICH WILL HOLD BACK COVERAGE OF ANY THUNDER...BUT THERE APPEARS TO BE GREAT JET SUPPORT VIA FORCED ASCENT OF RIGHT ENTRANCE REGION. SO THERE WILL AT LEAST BE A GOOD BATCH OF SHOWERS WITH THE FRONTAL PASSAGE. CONTINUED THE MENTION OF THUNDER FOR MOST OF THE CWA BUT EXCLUDED NW AREAS OVER THE LAKE PLAIN SINCE FRONT WILL CROSS THIS AREA EARLIER IN THE DAY. ISOLATED LIGHT SHOWERS COULD STILL OCCUR IN THE BRIEF COLD AIR ADVECTION BEHIND THE FRONT SATURDAY...MAINLY CENTRAL NY...BUT IN GENERAL THINGS WILL DRY OUT THIS WEEKEND. HIGH PRESSURE SUNDAY SHOULD YIELD SUNSHINE AND TEMPERATURES EDGING BACK ABOVE CLIMATOLOGY AFTER A CHILLY DAWN. FURTHER WARMING EXPECTED EARLY NEXT WEEK WITH THE NEXT CHANCE OF RAIN ARRIVING LATE MONDAY INTO TUESDAY. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... WORST FLYING CONDITIONS THROUGH MID MORNING WILL BE THE SOUTHERN TERMINALS. HERE WIDESPREAD MVFR CIGS AND VSBYS EXPECTED AS LIGHT RAIN OVERSPREADS THE TERMINALS. AT KELM AND KITH SOME IFR CIGS ARE POSSIBLE BETWEEN 09Z AND 14Z, WHILE AT KBGM IFR CIGS ARE LIKELY FROM NOW THROUGH MID MORNING. IN FACT AT KBGM BELOW ALT MINS LIKELY PRIOR TO DAYBREAK. BY LATE MORNING CIGS SLOWLY CREEP UP INTO MVFR RANGE AS SHOWERS COME TO AN END ACROSS THE SOUTH. UP NORTH SHOWERS BECOME MORE LIKELY WITH MVFR CIGS AND VSBYS IN RESPONSE TO THE SHOWERS. .OUTLOOK... WED NIGHT-FRI...BUSY PATTERN WITH WAFFLING FRONTAL BOUNDARY REMAINING IN THE VICINITY...AND WAVES OF SHRA PLUS ASSOCIATED RESTRICTIONS MOVING ALONG IT. SLIGHT CHC TSRA AS WELL FRI. SAT...MAINLY VFR BUT ISOLATED -SHRA STILL POSSIBLE OVER CENTRAL NY. SUN...VFR. SUN...VFR. .HYDROLOGY... RIVERS WILL CONTINUE TO RUN HIGH AS WE CONTINUE THE GRADUAL SNOW MELT RUN OFF FROM THE NORTH FACING SLOPES AND DEEP WOODS THIS WEEK. THAT COUPLED WITH THESE PERIODIC EPISODES OF RAIN WILL HAVE US FLIRT WITH A MINOR RIVER FLOOD POTENTIAL IN OUR MOST SENSITIVE HEADWATER AREAS. AT THIS TIME...THE RAIN AMOUNTS IN THE MODELS LOOK TOO ROBUST THROUGH THURSDAY...AS SEVERAL MODELS ARE OVER PERFORMING WITH EVEN TODAY`S RAIN...BUT AS THE DEEPER SYSTEM OVER THE UPPER MIDWEST WORKS EAST THIS WEEKEND IS WHEN WE WILL REALLY NEED TO PAY ATTENTION AS THEN CONFIDENCE IN MORE RIVER POINTS REACHING FLOOD STAGE MAY INCREASE. IN THE MEANTIME...THE NEXT 72 HOURS OR SO SHOULD BE OK WITH RIVERS RISING 3/4 TO NEAR BANKFULL AT TIMES. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...JAB NEAR TERM...DJP SHORT TERM...JAB LONG TERM...PCF AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1024 PM EDT THU APR 9 2015 .SYNOPSIS... WARM AND HUMID WEATHER WILL PRECEDE A STRONG COLD FRONT...WHICH WILL CROSS THE AREA LATE FRIDAY NIGHT. A FEW THUNDERSTORMS COULD BE STRONG FRIDAY NIGHT...WITH SHOWERS LINGERING INTO SATURDAY MORNING. DRY AND SEASONABLE CONDITIONS WILL MOVE INTO THE AREA THROUGH THE REMAINDER OF THE WEEKEND. A WARMING TREND WILL UNFOLD EARLY NEXT WEEK...WITH A CHANCE OF SHOWERS TUESDAY INTO WEDNESDAY AS GULF MOISTURE MOVES INTO THE REGION. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS OF 1030 PM THURSDAY...ALTHOUGH THE ODD POP-UP SHOWER CANT BE RULED OUT IT LOOKS LIKE SIGNIFICANT CONVECTION HAS ENDED FOR THE OVERNIGHT PERIOD. FORECAST UPDATED ACCORDINGLY. PREVIOUS DISCUSSION FROM THIS AFTERNOON FOLLOWS: INITIAL ROUND OF SHOWERS AND THUNDERSTORMS HAS DISSIPATED AS AN AREA OF SUBSIDENCE IN THE WAKE OF A PASSING IMPULSE ALOFT TEMPORARILY TAKES HOLD. DIURNAL CUMULUS HAS DEVELOPED UPSTREAM AND WITH GOOD INSOLATION ACROSS THE PEE DEE AND LUMBERTON AREAS THE AREA OF SUBSIDENCE WILL WEAKEN. OUTFLOW FROM CONVECTION ACROSS COASTAL SOUTHEAST NC HAS DROPPED INTO HORRY COUNTY... AS NOTED BY EARLIER VISIBLE SATELLITE IMAGERY. THE BOUNDARY COUPLED WITH THE SEA BREEZE SHOULD PROVIDE A SPARK FOR SCATTERED SHOWERS AND THUNDERSTORMS ACROSS NORTHEAST SC THIS AFTERNOON. WIDELY SCATTERED STORMS ARE ALSO POSSIBLE IN THE BETTER INSTABILITY EXPECTED ACROSS THE PEE DEE REGION. THE EARLIER RAINFALL WILL HAVE AN IMPACT ON TODAY/S MAX TEMPERATURES IN THE WILMINGTON AND VICINITY LOCATIONS. AS A RESULT...LOWERED FORECAST MAX TEMPS THERE...WHILE RETAINED HIGHS IN THE 80S FOR LBT...FLO...AND INLAND COASTAL SC LOCATIONS. WARM SOUTHWEST FLOW TONIGHT WILL KEEP MIN TEMPERATURES ABOVE NORMAL. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... AS OF 236 PM THURSDAY...CHIEF HEADLINES ARE A CHANGE OF AIR-MASS INTO SATURDAY FROM WARM TO MUGGY TO DRY AND MILD...AND A SHOT AT STRONG STORMS LATE FRIDAY AS A COLD FRONT MOVES THROUGH. SEVERE THREAT IS NOT SUPPORTED IN DIURNAL TIMING AS IT ARRIVES BEYOND PEAK SURFACE HEATING FRIDAY NIGHT...BUT COOLING ALOFT MAY SUPPORT SOME HAIL. TIME-HEIGHT ANALYSIS IS NOT OVERLY IMPRESSIVE WITH WINDS NO GREATER THAN 35 KNOTS IN THE LOWEST 8KFT...AND H8 25-30 KT BARBS. PEAK PRECIPITABLE WATER VALUES FRIDAY NIGHT AROUND 1.75 INCHES AND SOME JET SUPPORT ALOFT SHOULD OFFER A GOOD SHOT AT RAIN FRIDAY NIGHT INTO SATURDAY MORNING FROM WEST TO EAST...AND CLEARING THE COAST AROUND MIDDAY SATURDAY. UPPER 80 MAXIMUMS FRIDAY INLAND...LOW 80S COASTAL INTERIOR...AND UPPER 60S TO MIDDLE 70S BEACHES...WILL COOL TO 70S SATURDAY TO NEAR 80 WELL INLAND...UPPER 60S TO 70 BEACHES. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 236 PM THURSDAY...EXTENDED PERIOD LOOKS RATHER QUIET AS A MODEST SOUTHWEST FLOW ALOFT PERSISTS THROUGH THE PERIOD. HIGH PRESSURE WILL SETTLE OVER THE AREA SUNDAY AND MONDAY AND WITH PRECIPITABLE WATER VALUES ARE BELOW ONE HALF INCH SUNDAY WITH A SLOW INCREASE MONDAY. HAVE KEPT THESE DAYS DRY FOR THE MOST PART. SIGNIFICANT MOISTURE INCREASE FOR TUESDAY AND WEDNESDAY AS PWS SURGE TO IN EXCESS OF 1.5 INCHES. HOWEVER SYNOPTIC CONDITIONS SHOW LITTLE IN THE WAY OF FORCING AND POPS WILL REMAIN IN THE SLIGHT CHANCE CATEGORY. SIMILAR CONDITIONS FOR WEDNESDAY. FOR THURSDAY...MEDIUM RANGE GUIDANCE IS COMING INTO BETTER AGREEMENT WITH A BACKDOOR FRONT MOVING ACROSS AS A BROAD AREA OF MID LEVEL CONFLUENCE DEVELOPS ACROSS THE MIDWEST AND GREAT LAKES. I MAINTAINED THE POPS FOR THURSDAY AS MOISTURE REMAINS AND THE BOUNDARY IN THE AREA. NO CHANGES TO TEMPERATURE FORECAST FROM THE PREVIOUS FORECAST AS READINGS WILL BE JUST A LITTLE ABOVE NORMAL. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... AS OF 00Z...MOST OF THE CONVECTION HAS DIMINISHED...HOWEVER THERE IS ONE MORE IMPULSE THAT WILL MOVE INTO THE WESTERN CWA IN AN HOUR OR SO. THE HRRR MODEL HAS FAIRLY SPIRITED CONVECTION OVER THE WESTERN CWA FOR THE NEXT SEVERAL HOURS...BUT THINK THIS MAY BE OVERDONE. WILL KEEP ANY MENTION OF THUNDER OUT OF THE TAFS AT LBT AND FLO AT THIS TIME. OVERNIGHT...MID AND HIGH CLOUD CONVECTIVE DEBRIS IS EXPECTED WITH POSSIBLE MVFR FOG. FRIDAY...AN INCREASING SOUTHWEST GRADIENT AHEAD OF A COLD FRONT WILL GIVE US WIND GUSTS APPROACHING 25 KTS BY EARLY AFTERNOON. THERE SHOULD BE A FAIRLY VIGOROUS LINE OF CONVECTION THAT WILL MARCH ACROSS THE CWA FROM LATE AFTERNOON INTO THE EVENING HOURS. POSSIBLE DAMAGING WINDS AND HAIL CAN BE EXPECTED WITH THIS LINE OF STORMS. EXTENDED OUTLOOK...CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY NIGHT THROUGH MID MORNING SATURDAY. OTHERWISE EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 PM THURSDAY...LATEST OBS CONTINUE TO SHOW SEAS OF RIGHT AROUND 3 FT WITH SOUTHERLY WINDS OF 10 TO 15 KTS. THIS IS IN LINE WITH THE LATEST FORECAST. NO CHANGES WITH THE LATEST UPDATES. PREVIOUS DISCUSSION FOLLOWS: CONVECTION HAS RESULTED IN A VARIABLE WIND FIELD ACROSS THE NC COASTAL WATERS EARLY THIS AFTERNOON. THE LARGER SCALE SYNOPTIC FLOW WILL ONCE AGAIN TAKE HOLD LATER THIS AFTERNOON WITH THE RETURN OF SOUTHERLY FLOW. SPEEDS WILL GENERALLY RANGE FROM 10 TO 15 KNOTS DURING THE OVERNIGHT. OUTSIDE ANY CONVECTION...SEAS ARE EXPECTED TO BE IN THE 2-4 FT RANGE THROUGH THE NEAR TERM. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 236 PM THURSDAY...DESPITE A COLD FRONTAL PASSAGE VERY EARLY SATURDAY JUST PRIOR TO...OR AROUND DAYBREAK THAT MAY BRING A FEW STRONG THUNDERSTORMS...NO SMALL CRAFT ADVISORIES ARE PLANNED...AS WINDS AHEAD OF AND BEHIND THE FRONT REMAIN MOSTLY BELOW 20 KT. GUSTS TO 20 KT FRIDAY AFTERNOON SEEMS LIKELY WITH SEA BREEZE ASSISTANCE...BUT SUSTAINED WINDS ARE NOT OVERLY STRONG WITH THIS SYSTEM OUTSIDE OF TSTMS. A FEW MARINE WARNINGS ARE POSSIBLE LATE FRIDAY NIGHT INTO EARLY SATURDAY. SEAS OF 2-3 FEET WILL BUILD TO 3-4 FEET FRIDAY NIGHT...POSSIBLY 5 FT VERY OUTER PORTION. PATCHY SEA FOG POSSIBLE FRIDAY BUT WATERS HAVE WARMED AND CONFIDENCE IS LOW ON ITS FORMATION. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 236 PM THURSDAY...SURFACE HIGH PRESSURE WILL MOVE FROM THE APPALACHIANS TO WELL OFFSHORE DURING THE PERIOD. WINDS WILL RESPOND BY VEERING FROM NORTHEAST SUNDAY TO SOUTHEAST BY MIDDAY MONDAY. THEY WILL MAINTAIN THIS DIRECTION THROUGH THE REMAINDER OF THE PERIOD. SPEEDS WILL BE ON THE HIGHER END OF A 10-15 KNOT RANGE SUNDAY THEN SETTLE INTO THE ENTIRE RANGE MONDAY AND TUESDAY. SIGNIFICANT SEAS WILL BE 2-4 FEET SUNDAY DROPPING TO 1-3 FEET LATER MONDAY AND TUESDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MJC NEAR TERM...REK/SRP SHORT TERM...MJC LONG TERM...SHK AVIATION...DL MARINE...MJC/REK/SHK/SRP
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
729 PM EDT THU APR 9 2015 .SYNOPSIS... WARM AND HUMID WEATHER WILL PRECEDE A STRONG COLD FRONT...WHICH WILL CROSS THE AREA LATE FRIDAY NIGHT. A FEW THUNDERSTORMS COULD BE STRONG FRIDAY NIGHT...WITH SHOWERS LINGERING INTO SATURDAY MORNING. DRY AND SEASONABLE CONDITIONS WILL MOVE INTO THE AREA THROUGH THE REMAINDER OF THE WEEKEND. A WARMING TREND WILL UNFOLD EARLY NEXT WEEK...WITH A CHANCE OF SHOWERS TUESDAY INTO WEDNESDAY AS GULF MOISTURE MOVES INTO THE REGION. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS OF 730 PM THURSDAY...ISOLATED CONVECTION NOW CONFINED TO OUR FAR INLAND COUNTIES BUT HAS BEEN STUBBORNLY PERSISTENT. NO STRONG CONVECTION AT PRESENT AND PRESENT TRENDS AND GUIDANCE INDICATE A VERY GRADUAL WEAKENING WITH A LULL IN THE ACTION FOR THE EARLY MORNING HOURS. PREVIOUS DISCUSSION FOLLOWS: INITIAL ROUND OF SHOWERS AND THUNDERSTORMS HAS DISSIPATED AS AN AREA OF SUBSIDENCE IN THE WAKE OF A PASSING IMPULSE ALOFT TEMPORARILY TAKES HOLD. DIURNAL CUMULUS HAS DEVELOPED UPSTREAM AND WITH GOOD INSOLATION ACROSS THE PEE DEE AND LUMBERTON AREAS THE AREA OF SUBSIDENCE WILL WEAKEN. OUTFLOW FROM CONVECTION ACROSS COASTAL SOUTHEAST NC HAS DROPPED INTO HORRY COUNTY... AS NOTED BY EARLIER VISIBLE SATELLITE IMAGERY. THE BOUNDARY COUPLED WITH THE SEA BREEZE SHOULD PROVIDE A SPARK FOR SCATTERED SHOWERS AND THUNDERSTORMS ACROSS NORTHEAST SC THIS AFTERNOON. WIDELY SCATTERED STORMS ARE ALSO POSSIBLE IN THE BETTER INSTABILITY EXPECTED ACROSS THE PEE DEE REGION. THE EARLIER RAINFALL WILL HAVE AN IMPACT ON TODAY/S MAX TEMPERATURES IN THE WILMINGTON AND VICINITY LOCATIONS. AS A RESULT...LOWERED FORECAST MAX TEMPS THERE...WHILE RETAINED HIGHS IN THE 80S FOR LBT...FLO...AND INLAND COASTAL SC LOCATIONS. WARM SOUTHWEST FLOW TONIGHT WILL KEEP MIN TEMPERATURES ABOVE NORMAL. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... AS OF 236 PM THURSDAY...CHIEF HEADLINES ARE A CHANGE OF AIR-MASS INTO SATURDAY FROM WARM TO MUGGY TO DRY AND MILD...AND A SHOT AT STRONG STORMS LATE FRIDAY AS A COLD FRONT MOVES THROUGH. SEVERE THREAT IS NOT SUPPORTED IN DIURNAL TIMING AS IT ARRIVES BEYOND PEAK SURFACE HEATING FRIDAY NIGHT...BUT COOLING ALOFT MAY SUPPORT SOME HAIL. TIME-HEIGHT ANALYSIS IS NOT OVERLY IMPRESSIVE WITH WINDS NO GREATER THAN 35 KNOTS IN THE LOWEST 8KFT...AND H8 25-30 KT BARBS. PEAK PRECIPITABLE WATER VALUES FRIDAY NIGHT AROUND 1.75 INCHES AND SOME JET SUPPORT ALOFT SHOULD OFFER A GOOD SHOT AT RAIN FRIDAY NIGHT INTO SATURDAY MORNING FROM WEST TO EAST...AND CLEARING THE COAST AROUND MIDDAY SATURDAY. UPPER 80 MAXIMUMS FRIDAY INLAND...LOW 80S COASTAL INTERIOR...AND UPPER 60S TO MIDDLE 70S BEACHES...WILL COOL TO 70S SATURDAY TO NEAR 80 WELL INLAND...UPPER 60S TO 70 BEACHES. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 236 PM THURSDAY...EXTENDED PERIOD LOOKS RATHER QUIET AS A MODEST SOUTHWEST FLOW ALOFT PERSISTS THROUGH THE PERIOD. HIGH PRESSURE WILL SETTLE OVER THE AREA SUNDAY AND MONDAY AND WITH PRECIPITABLE WATER VALUES ARE BELOW ONE HALF INCH SUNDAY WITH A SLOW INCREASE MONDAY. HAVE KEPT THESE DAYS DRY FOR THE MOST PART. SIGNIFICANT MOISTURE INCREASE FOR TUESDAY AND WEDNESDAY AS PWS SURGE TO IN EXCESS OF 1.5 INCHES. HOWEVER SYNOPTIC CONDITIONS SHOW LITTLE IN THE WAY OF FORCING AND POPS WILL REMAIN IN THE SLIGHT CHANCE CATEGORY. SIMILAR CONDITIONS FOR WEDNESDAY. FOR THURSDAY...MEDIUM RANGE GUIDANCE IS COMING INTO BETTER AGREEMENT WITH A BACKDOOR FRONT MOVING ACROSS AS A BROAD AREA OF MID LEVEL CONFLUENCE DEVELOPS ACROSS THE MIDWEST AND GREAT LAKES. I MAINTAINED THE POPS FOR THURSDAY AS MOISTURE REMAINS AND THE BOUNDARY IN THE AREA. NO CHANGES TO TEMPERATURE FORECAST FROM THE PREVIOUS FORECAST AS READINGS WILL BE JUST A LITTLE ABOVE NORMAL. && .AVIATION /23Z THURSDAY THROUGH TUESDAY/... AS OF 00Z...MOST OF THE CONVECTION HAS DIMINISHED...HOWEVER THERE IS ONE MORE IMPULSE THAT WILL MOVE INTO THE WESTERN CWA IN AN HOUR OR SO. THE HRRR MODEL HAS FAIRLY SPIRITED CONVECTION OVER THE WESTERN CWA FOR THE NEXT SEVERAL HOURS...BUT THINK THIS MAY BE OVERDONE. WILL KEEP ANY MENTION OF THUNDER OUT OF THE TAFS AT LBT AND FLO AT THIS TIME. OVERNIGHT...MID AND HIGH CLOUD CONVECTIVE DEBRIS IS EXPECTED WITH POSSIBLE MVFR FOG. FRIDAY...AN INCREASING SOUTHWEST GRADIENT AHEAD OF A COLD FRONT WILL GIVE US WIND GUSTS APPROACHING 25 KTS BY EARLY AFTERNOON. THERE SHOULD BE A FAIRLY VIGOROUS LINE OF CONVECTION THAT WILL MARCH ACROSS THE CWA FROM LATE AFTERNOON INTO THE EVENING HOURS. POSSIBLE DAMAGING WINDS AND HAIL CAN BE EXPECTED WITH THIS LINE OF STORMS. EXTENDED OUTLOOK...CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY NIGHT THROUGH MID MORNING SATURDAY. OTHERWISE EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 730 PM THURSDAY...LATEST OBS SHOW SEAS OF RIGHT AROUND 3 FT WITH SOUTHERLY WINDS OF 10 TO 15 KTS. THIS IS IN LINE WITH THE LATEST FORECAST. NO CHANGES WITH THE LATEST UPDATES. PREVIOUS DISCUSSION FOLLOWS: CONVECTION HAS RESULTED IN A VARIABLE WIND FIELD ACROSS THE NC COASTAL WATERS EARLY THIS AFTERNOON. THE LARGER SCALE SYNOPTIC FLOW WILL ONCE AGAIN TAKE HOLD LATER THIS AFTERNOON WITH THE RETURN OF SOUTHERLY FLOW. SPEEDS WILL GENERALLY RANGE FROM 10 TO 15 KNOTS DURING THE OVERNIGHT. OUTSIDE ANY CONVECTION...SEAS ARE EXPECTED TO BE IN THE 2-4 FT RANGE THROUGH THE NEAR TERM. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 236 PM THURSDAY...DESPITE A COLD FRONTAL PASSAGE VERY EARLY SATURDAY JUST PRIOR TO...OR AROUND DAYBREAK THAT MAY BRING A FEW STRONG THUNDERSTORMS...NO SMALL CRAFT ADVISORIES ARE PLANNED...AS WINDS AHEAD OF AND BEHIND THE FRONT REMAIN MOSTLY BELOW 20 KT. GUSTS TO 20 KT FRIDAY AFTERNOON SEEMS LIKELY WITH SEA BREEZE ASSISTANCE...BUT SUSTAINED WINDS ARE NOT OVERLY STRONG WITH THIS SYSTEM OUTSIDE OF TSTMS. A FEW MARINE WARNINGS ARE POSSIBLE LATE FRIDAY NIGHT INTO EARLY SATURDAY. SEAS OF 2-3 FEET WILL BUILD TO 3-4 FEET FRIDAY NIGHT...POSSIBLY 5 FT VERY OUTER PORTION. PATCHY SEA FOG POSSIBLE FRIDAY BUT WATERS HAVE WARMED AND CONFIDENCE IS LOW ON ITS FORMATION. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 236 PM THURSDAY...SURFACE HIGH PRESSURE WILL MOVE FROM THE APPALACHIANS TO WELL OFFSHORE DURING THE PERIOD. WINDS WILL RESPOND BY VEERING FROM NORTHEAST SUNDAY TO SOUTHEAST BY MIDDAY MONDAY. THEY WILL MAINTAIN THIS DIRECTION THROUGH THE REMAINDER OF THE PERIOD. SPEEDS WILL BE ON THE HIGHER END OF A 10-15 KNOT RANGE SUNDAY THEN SETTLE INTO THE ENTIRE RANGE MONDAY AND TUESDAY. SIGNIFICANT SEAS WILL BE 2-4 FEET SUNDAY DROPPING TO 1-3 FEET LATER MONDAY AND TUESDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MJC NEAR TERM...REK/SRP SHORT TERM...MJC LONG TERM...SHK AVIATION...DL MARINE...MJC/REK/SHK/SRP
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
959 AM EDT WED APR 8 2015 .SYNOPSIS... A COLD FRONT WILL PUSH SOUTH INTO THE REGION THIS AFTERNOON AND STALL OVER THE AREA TONIGHT. THE FRONT WILL LIFT NORTH OF THE REGION LATE THURSDAY. A COLD FRONT WILL APPROACH FROM THE WEST LATE FRIDAY AND MOVE OFFSHORE SATURDAY MORNING. HIGH PRESSURE WILL EXTEND OVER THE AREA FROM THE NORTH SATURDAY NIGHT AND SUNDAY. A WARM FRONT WILL LIFT NORTH OF THE AREA TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 10 AM WEDNESDAY...ONE AREA OF PRECIP ALBEMARLE SOUND REGION AND NORTHERN OUTER BANKS MOVG OFFSHORE AND ANOTHER DVLPG JUST W OF THE NRN COASTAL PLAINS. THE 4 KM WRF MODEL SHOWS AREA OF CONVECTION MOVG INTO THE NRN COASTAL PLAINS AND PROGRESSING E-SE ACRS THE AREA THROUGH ABT 18Z. GIVEN RADAR TRENDS...AND ADDITIONAL FOCUS OF BACKDOOR FNT ACRS NERN AREAS WILL RAISE POPS TO LIKELY WITH MODERATE SHOWERS AND HIGHER QPF VALUES ACRS THE NRN TIER CWFA AND EXTEND THROUGH EARLY AFTN. WILL CONT WITH HIGH CHC 40% POPS FOR SRN TIER THROUGH EARLY AFTN AS WELL. H5 IMPL WORKING THROUGH THE AREA HELPING TO INITIATE CONVECTION LATE THIS MORN THROUGH EARLY AFTN. LIKELY WILL SEE SUBSIDENCE IN THE WAKE OF THE WAVE WITH CONVECTION DIMINISHING BUT WITH UNSTABLE AMS WITH TEMPS IN THE LWR 80S AND FOCUS OF BACKDOOR FNT WILL KEEP LOW CHC POPS ALL BUT IMMEDIATE COAST WHERE WILL HAVE SLGT CHC POPS FOR THE RMNDR OF THE AFTN. OTRW...MADE MINOR TWEAKS TO INIT T/TD. PREV DISC...VERY DIFFICULT FORECAST NEXT 36 HOURS IN TRYING TO PROVIDE DETAIL REGARDING PRECIPITATION CHANCES IN THE MOIST BUT WEAKLY FORCED ATMOSPHERE OVER THE CAROLINAS. ZONAL FLOW WILL CONTINUE ALBEIT WITH RIDGING AND ASSOCIATED SUBTLE HEIGHT RISES OVER THE SOUTHEAST STATES THROUGH THURSDAY. WEAK LOW AMPLITUDE MID LEVEL WAVES IN THIS FLOW WILL HAVE THE POTENTIAL TO ENHANCE PRECIPITATION CHANCES ESPECIALLY IF THE ORGANIZED CONVECTION EXPECTED OVER THE PLAINS TODAY TRIGGERS A STRONGER MCV WHICH WOULD THEN MOVE EASTWARD TONIGHT. THE LARGE SCALE MODELS HAVE BEEN HAVING A DIFFICULT TIME IN HANDLING THIS SITUATION SO HAVE A RELIED ON THE HRRR AND THE HIGH RESOLUTION NMM AND WRF MODELS TO TRY TO GET A BETTER HANDLE ON THIS. TEMPERATURES WILL BE ABOVE NORMAL TODAY IN THE SOUTHERLY PRE FRONTAL FLOW WITH HIGHS INLAND IN THE LOWER 80S AND LOWER 70S BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/... AS OF 400 AM WEDNESDAY...THE BACK DOOR FRONT WILL SAG SOUTH TO NEAR THE CRYSTAL COAST OVERNIGHT THEN STALL. STILL UNCERTAIN ON PRECIPITATION DETAILS SO WILL FORECAST 30-50% POPS HIGHEST OUTER BANKS. LOWS ARE FORECAST TO CONTINUE MILD WITH READINGS IN THE UPPER 50S/LOWER 60S. && .LONG TERM /THURSDAY THROUGH TUESDAY/... AS OF 330 AM WEDNESDAY...00Z MODELS HAVE COME INTO BETTER AGREEMENT WITH BACKDOOR FRONT STALLING OVER SRN SECTIONS LATE WED NIGHT...THEN RETREATING NORTH ON THU. ECWMF AND GFS ALSO IN GOOD AGREEMENT THAT STRONGER COLD FRONT WILL MOVE IN FRIDAY NIGHT AND BE NEAR COAST SAT MORNING...THUS INCREASED POPS FRI NIGHT AND DECREASED INLAND SAT. THURSDAY AND THURSDAY NIGHT...SFC FRONT EXPECTED TO RETREAT NORTH DURING THE DAY WITH WEAK RIDGING ALOFT. LACK OF UPR SUPPORT EXPECTED TO LIMIT CONVECTIVE DEVELOPMENT BUT KEPT 20% POPS WITH FRONT MOVING BACK NORTH. DID DROP POPS FOR THU NIGHT WITH MODELS INDICATING PCPN THREAT WEST AND NORTH OF AREA. MOS GDNC CONTINUES TO HAVE LARGE DIFFERENCES ON HIGH TEMPS WITH GFS COOLER AND NAM WARMER DUE TO HANDLING OF FRONT. UPDATED PREVIOUS FCST WITH LEAN TO COOLER GFS...HIGHS RANGING FROM AROUND 80 SOUTH TO 65-70 NORTH. FRIDAY THROUGH SATURDAY...VERY WARM TEMPS EXPECTED FRIDAY AHEAD OF A STRONGER COLD FRONT APPROACHING FRIDAY NIGHT. NO CHANGE TO PREVIOUS THINKING FOR SHOWERS AND THUNDERSTORMS FRIDAY FOR INLAND SECTIONS AS DECENT INSTABILITY AND UNIDIRECTIONAL WEST-SOUTHWEST FLOW IS ENOUGH TO SUPPORT CHC POPS IN AFTERNOON INLAND OF SEA BREEZE. LOW LEVEL THICKNESSES SUPPORT MID 80S FOR INLAND SECTIONS. LATEST MODELS AGREE ON MAIN THREAT OF SHOWERS AND TSTMS ALONG AND AHEAD OF COLD FRONT FRIDAY NIGHT...AND INCREASED POPS TO 60% ALL ZONES...MAINLY FOR WRN HALF DURING EVENING AND ERN HALF OVERNIGHT. CONCUR WITH SPC OUTLOOK OF SLIGHT RISK OF SVR WITH SUFFICIENT MID LVL SHEAR TO SUPPORT ORGANIZED STRONG CONVECTION. FRONT EXPECTED TO MOVE OFFSHORE SAT MORNING AND HAVE LOWERED POPS TO INDICATE DRIER TREND. MAX TEMPS ABOUT 10 DEGS COOLER THAN FRIDAY WITH MID 70S INLAND TO LOWER 60S NRN OBX. SATURDAY NIGHT THROUGH SUNDAY NIGHT...STRONG HIGH PRES WILL EXTEND OVER AREA FROM NORTH SAT NIGHT AND SUNDAY AND GRADUALLY MOVE EAST SUN NIGHT. DRY CONDITIONS EXPECTED WITH TEMPS NEAR NORMAL. MONDAY INTO TUESDAY...NO CHANGE TO PREVIOUS FCST. HIGH PRES WILL CONTINUE MOVING OFFSHORE WITH MOIST S TO SW FLOW RETURNING. SLIGHT CHC POPS FOR SW HALF OF AREA MONDAY AND MON NIGHT...INCREASING TO 20-30% ALL AREAS TUESDAY. MAIN TEMP CHANGE WILL BE MIN TEMPS 10-15 DEGS ABOVE NORMAL MON NIGHT. && .AVIATION /13Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM /THROUGH TONIGHT/... AS OF 10 AM WEDNESDAY...DIFFICULT FORECAST WITH PRECIPITATION APPROACHING THE TAF SITES FROM THE WEST. PRECIPITATION WILL AFFECT THE TAF SITES ON AND OFF FM 14-18Z WITH BRIEF MVFR CONDITIONS POSSIBLE IN HEAVIER SHOWERS AND STORMS. VFR CONDITIONS EXPECTED OUTSIDE OF SCATTERED SHOWER/THUNDERSTORM ACTIVITY THROUGH THIS EVENING. GUIDANCE IS AGAIN POINTING TO THE POTENTIAL FOR IFR CONDITIONS REDEVELOPING AGAIN LATE THIS EVENING AS THE BL REMAINS SATURATED BUT CONFIDENCE IN THIS LOW DUE TO RECENT TENDENCY FOR GUIDANCE TO OVER FORECAST THESE CONDITIONS. LOW LEVEL EASTERLY FLOW BEHIND THE BACK DOOR FRONT MAY BE MORE CONDUCIVE TO IFR CONDITIONS THOUGH SO WILL HAVE TO CONTINUE TO MONITOR. LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 400 AM WEDNESDAY...SOME LOWER CIGS COULD PERSIST THURS MORNING WITH LOW LEVEL NE FLOW. VFR MAINLY EXPECTED THURS NIGHT INTO FRIDAY...THEN HIGHER THREAT OF SUB-VFR CONDITIONS FRI NIGHT INTO EARLY SAT WITH GOOD COVERAGE OF SHOWERS AND TSTMS EXPECTED AS STRONGER FRONT MOVES INTO AREA. GUSTY SW WINDS 15-25 MPH LIKELY FRIDAY AHEAD OF FRONT. HIGH PRESSURE WILL ALLOW AVIATION CONDITIONS TO IMPROVE TO VFR SATURDAY EVENING THROUGH SUNDAY. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 10 AM WEDNESDAY...NO SIG CHANGES ON UPDATE. WINDS WILL REMAIN 15 KT OR LESS THROUGH TONIGHT. THE MAIN FEATURE WILL BE A BACK DOOR COLD FRONT WHICH IS FORECAST TO PUSH SOUTH INTO THE NORTHERN WATERS/ALBEMARLE SOUND TODAY THEN CONTINUE SOUTH TONIGHT INTO THE CENTRAL WATERS/PAMLICO SOUND WHERE IT WILL STALL. EXPECT WINDS TO VEER FROM SOUTHERLY THIS MORNING TO SOUTHWEST TO WEST BY THIS AFTERNOON THEN TO NORTH AND NORTHEAST BEHIND THE FRONT LATER TODAY AND TONIGHT. SEAS WILL REMAIN IN THE 2-4 FT RANGE THROUGH THE PERIOD. LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 400 AM WEDNESDAY...CONTINUED PREVIOUS FCST THINKING WITH WINDS GRADUALLY RETURNING TO S-SW DURING THE DAY THU AS FRONT RETREATS BACK NORTH. MAIN CHANGE WAS TO INDICATE FASTER COLD FRONT PASSAGE SAT MORNING WITH LATEST MODELS IN GOOD AGREEMENT. STILL EXPECT STRONGEST WINDS FRI AND FRI NIGHT AHEAD OF FRONT...SW 15-25 KT WITH SEAS BUILDING TO SMALL CRAFT ADVISORY LEVELS FRI AFTN INTO EARLY SAT. NE SURGE 10-20 KT EXPECTED LATE SAT THROUGH SUNDAY. ADJUSTED SEAS WITH LATEST NWPS. HEIGHTS MAINLY 3-4 FT THU...BUILDING TO 4-6 FT FRI-FRI NIGHT...THEN DIMINISHING 2-4 FT SUNDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JME NEAR TERM...JAC/JME SHORT TERM...JME LONG TERM...JBM AVIATION...JAC/JME/JBM MARINE...JAC/JME/JBM
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
819 AM EDT WED APR 8 2015 .SYNOPSIS... UNSEASONABLY WARM AND HUMID WEATHER WILL PREVAIL OVER THE NEXT FEW DAYS...AS HIGH PRESSURE OFFSHORE CIRCULATES BALMY AIR INTO THE REGION. SHOWERS AND A FEW THUNDERSTORMS WILL ACCOMPANY THE MILD CONDITIONS...WITH RAIN CHANCES INCREASING FRIDAY NIGHT AND SATURDAY MORNING ASSOCIATED WITH A FRONTAL PASSAGE. A DRYING TREND WITH SEASONABLE TEMPERATURES WILL ARRIVE FOR THE REMAINDER OF THE WEEKEND...WITH A WARMING TREND EXPECTED EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 600 AM WEDNESDAY...THE LAST OF THE SHORTWAVE ENERGY WAS PIVOTING ACROSS FORECAST AREA. A FEW VERY LIGHT SHOWERS WERE ONGOING...BUT WERE ENDING WEST OF INTERSTATE 95. THE HIGH RESOLUTION HRRR MODEL WAS INDICATING A SLIGHT REJUVENATION IN THIS ACTIVITY ACROSS THE CAPE FEAR RIVER AREA AFTER SUNRISE AND HAVE INCLUDED HIGHEST MORNING POPS HERE. THE TROUGH WILL BE OFFSHORE BY MID MORNING. CURRENT THINKING IS THAT IN THE WAKE OF THE MID-LEVEL TROUGH... SUBSIDENCE WILL BE ON THE INCREASE MID AND LATE MORNING. HOWEVER...THE COLUMN IS EXPECTED TO BECOME QUITE UNSTABLE WITH MIXED LAYER CAPE VALUES ON THE ORDER OF 1500-2000 J/KG...HIGHEST THIS AFTERNOON. DO NOT SEE ANY DISCERNIBLE FEATURES ALOFT TO TRIGGER ANYTHING MORE THAN AIRMASS SHOWERS AND THUNDERSTORMS. THE INLAND PENETRATING SEABREEZE BOUNDARY AND RESIDUAL OUTFLOW BOUNDARIES MAY BECOME POINTS OF CONVECTIVE INITIATION/ORGANIZATION. RATHER WARM AND RELATIVELY DRIER AIR ALOFT MAY ALSO ACT TO HINDER CONVECTION THIS AFTERNOON. WILL CAP POPS AT SLIGHT CHANCE/SMALL CHANCE FOR THE REMAINDER OF THE DAY. CONCERN FOR TONIGHT IS THAT WITH A POTENT...BUT DAMPENING MID-LEVEL TROUGH APPROACHING FROM THE WNW...ITS ASSOCIATED COOLER AIR IN THE MID LEVELS MAY HELP TO MAINTAIN UPSTREAM CONVECTION AS IT MOVES INTO THE EASTERN CAROLINAS. THUS...WILL SHOW MAINLY SCATTERED SHOWERS AND SOME THUNDERSTORMS... LIKELY MOST NUMEROUS ACROSS INLAND PORTIONS OF SOUTHEAST NORTH CAROLINA AND THE ADJACENT PEE DEE REGION OF SOUTH CAROLINA. CONSIDERABLE CLOUD COVER IS EXPECTED TO GIVE WAY TO SIGNIFICANT BREAKS OF SUNSHINE AND WITH THAT...EXPECT TEMPS WELL UP INTO THE 80S INLAND TODAY WHERE RECORDS AT KLBT AND KFLO ARE 90 DEGREES. ALONG THE COAST...THE SEABREEZE IS EXPECTED TO MAKE DECENT INLAND PROGRESS...ESPECIALLY ACROSS NORTH CAROLINA AND SO WILL CAP HIGHS IN THE CAPE FEAR REGION IN THE UPPER 70S AND LOWER 80S. THE MORE IMMEDIATE CAROLINA COAST WILL LIKELY BE STYMIED IN THE MID 70S WITH SOME BEACHES IN THE LOWER 70S. ANOTHER BALMY NIGHT UPCOMING WITH LOWS TONIGHT REMAINING WELL ABOVE NORMAL...LOWER TO MID 60S. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 330 AM WEDNESDAY...EXPECT SUMMER-LIKE WEATHER THROUGH THURS AND FRI WITH UNSEASONABLY WARM TEMPERATURES AS BERMUDA HIGH DOMINATES THE WEATHER. A BACKDOOR COLD FRONT WILL DROP DOWN INTO NORTH CAROLINA AND MAY REACH FAR ENOUGH SOUTH TO PRODUCE MORE VARIABLE WINDS EARLY THURS MORNING...BUT NOT EXPECTING THIS FEATURE TO BE MUCH OF A PLAYER IN OUR OVERALL FORECAST. HIGH PRESSURE OFF SHORE WILL DOMINATE...PRODUCING A DEEPER WARM AND MOIST S-SW RETURN FLOW THROUGH THE LOW LEVELS OF THE ATMOSPHERE...INCREASING INTO FRIDAY AS COLD FRONT APPROACHES THE CAROLINAS FROM THE W-NW. THIS MORE SUMMER-LIKE MOIST AND MORE UNSTABLE AIR MASS WILL HAVE THE POTENTIAL TO PRODUCE SOME LOCALIZED CLOUDS AND CONVECTION ESPECIALLY AS MID TO UPPER RIDGE SLIPS OFF THE COAST LATE THURS. THE SEA BREEZE WILL PENETRATE FAR ENOUGH INLAND ON THURS TO KEEP MOST SHOWER ACTIVITY AWAY FROM THE COAST BUT THE WESTERLY FLOW ALOFT SHOULD CARRY SOME OF THE DEBRIS CLOUDS EASTWARD. WITH CLOUDS AND HIGH DEWPOINT AIR...TEMPS WILL REMAIN WELL ABOVE NORMAL OVERNIGHT GIVING A JUMPSTART TO DAY TIME HIGHS WHICH WILL REACH INTO THE 80S AND 70S CLOSER TO THE COAST. DEEP MOIST SOUTHWESTERLY FLOW WILL INCREASE THROUGH FRIDAY AS COLD FRONT APPROACHES FROM THE W-NW. THIS WILL INCREASE MOISTURE THROUGH THE COLUMN WITH PCP WATER VALUES INCREASING UP CLOSE TO 1.75 INCHES BY FRI NIGHT IN DECENT LLJ. INITIALLY A STRONGER SEA BREEZE SHOULD KEEP BEST CONVERGENCE AND CONVECTION AWAY FROM COAST BUT AS STEERING FLOW VEERS AROUND WITH APPROACH OF FRONT...SHWRS AND STORMS WILL REACH THE COAST. STRONGER CONVECTION IS LIKELY AHEAD OF THE COLD FRONT...BUT THE BEST DYNAMICS ALOFT WILL REMAIN NW OF FORECAST AREA AND THE COLD FRONT WILL COME THROUGH OVERNIGHT AFTER BEST DIURNAL HEATING CUTS OFF. THEREFORE STRONGER CONVECTION MAY REMAIN MORE ISOLATED. COLD FRONT SHOULD BE RIGHT AT THE COAST BY SAT MORNING. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 330 AM WEDNESDAY...COLD FRONT RIGHT ALONG THE CAROLINA COAST SATURDAY MORNING MAY GET HUNG UP BEFORE MAKING ITS WAY SOUTH LATER IN THE DAY. THIS COULD LEAVE SOME LINGERING PCP ALONG THE COAST THROUGH SAT MORNING BUT OVERALL EXPECT HIGH PRESSURE TO BUILD DOWN BEHIND FRONT BRINGING A CHANGE OF AIR MASS TO THE CAROLINAS. PCP WATER VALUES WILL DROP FROM CLOSE TO 1.75 INCHES AHEAD OF FRONT DOWN CLOSE TO A HALF INCH BEHIND IT BY SAT AFTN. EXPECT WINDS TO SHIFT AROUND TO A MORE NORTHERLY DIRECTION. COOLER AIR BEHIND FRONT WILL BRING TEMPS BACK TO NORMAL SEASONABLE VALUES THROUGH THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK. GFS IS MORE OPTIMISTIC WITH THE CLEARING BEHIND THE FRONT AND WILL HEDGE TOWARD THIS SOLUTION WITH CLEARING THROUGH LATE SATURDAY AND SUNSHINE FOR SUNDAY. HIGH PRESSURE WILL SLIP OFF THE COAST MONDAY INTO TUES WITH A DEEPER RETURN FLOW SETTING UP ONCE AGAIN. THIS WILL INTRODUCE POPS BACK INTO THE FORECAST WITH A WARMER AND MORE UNSTABLE AIR MASS RETURNING....BUT THE GFS KEEPS THE RIDGE FARTHER WEST AND THEREFORE KEEPS BEST RETURN FLOW FARTHER INLAND. ALSO THE COOLER OCEAN WATERS WILL KEEP A STRONGER SEA BREEZE THIS TIME OF YEAR AND THEREFORE SHOULD PENETRATE FARTHER INLAND MON AND TUES KEEPING BEST CHC OF PCP FARTHER INLAND. MAY END UP SUNNIER WEATHER BOTH MON AND TUES FOR MOST OF THE FORECAST AREA. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AS OF 12Z...INTERMITTENT MVFR THIS MORNING WILL GIVE WAY TO VFR OVER THE NEXT FEW HOURS AND CONTINUE THROUGH THE REST OF TODAY. POTENTIAL FOR MVFR LATE OVERNIGHT INTO EARLY THURSDAY MORNING DUE TO AREAS OF FOG AND LOW CIGS. VFR PREVAILS ACROSS MOST OF THE FORECAST AREA THIS MORNING...WITH THE EXCEPTION OF KLBT WHICH IS CURRENTLY OBSERVING MVFR CONDITIONS DUE TO FOG. EXPECT OVER THE NEXT FEW HOURS FOR CONDITIONS TO IMPROVE TO VFR ACROSS THE ENTIRE AREA...THOUGH WOULD NOT RULE OUT A PASSING LIGHT SHOWER OR TWO. LIGHT WINDS THIS MORNING WILL BECOME SOUTH-SOUTHWESTERLY...BACKING TO THE SOUTH THIS AFTERNOON AOB 10 KTS WITH ISOLATED SHOWERS POSSIBLE ON THE AFTERNOON SEA BREEZE. TONIGHT...VFR WILL PREVAIL WITH WINDS BECOMING LIGHT. MVFR POSSIBLE DUE TO FOG AND PASSING LOW CIGS LATE OVERNIGHT INTO THE EARLY MORNING HOURS ON THURSDAY. EXTENDED OUTLOOK...CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY AND BEST CHANCE FOR PRECIPITATION IS FRIDAY NIGHT INTO SATURDAY MORNING. OTHERWISE EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 600 AM WEDNESDAY...A BACKDOOR COLD FRONT WILL SLOWLY SAG SOUTH TOWARD THE AREA...REACHING JUST SOUTH OF THE VIRGINIA-NORTH CAROLINA LINE BY THE END OF THE PERIOD. CIRCULATION AROUND OFFSHORE HIGH PRESSURE WILL BE A LITTLE MORE WEST OF DUE SOUTH THAN IN RECENT DAYS...BUT THE DIRECTION IS EXPECTED TO BACK SLIGHTLY AS THE SEABREEZE BOUNDARY SHARPENS AND MOVES INLAND LATE MORNING AND THIS AFTERNOON AND EXPECT WIND SPEEDS WILL BE ENHANCED SLIGHTLY ACROSS THE NEAR SHORE WATERS DURING THIS TIME. STILL...WILL NOT FORECAST SUSTAINED WINDS ANY HIGHER THAN 10 TO 15 KT WITH GUSTS AROUND 20 KT LIKELY. THE WIND DIRECTION WILL BE SW TONIGHT. SOME NOCTURNAL JETTING MAY MIX DOWN ACROSS THE WARMER OFFSHORE WATERS...BUT WITHIN 20 NM...EXPECT WIND SPEEDS WILL BE CAPPED AT 15 KT. A SE SWELL ON THE ORDER OF 8 TO 9 SECONDS ALONG WITH WIND ENERGY WILL HELP KEEP SEAS IN THE 3 TO 4 FT RANGE. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 330 AM WEDNESDAY...RETURN FLOW AROUND BERMUDA HIGH THURS INTO FRIDAY WILL INCREASE ON FRIDAY AS COLD FRONT APPROACHES FROM THE NORTHWEST. SEAS 2 TO 3 FT EXPECTED WITH S-SW WINDS OF 10 TO 15 KT WILL INCREASE THROUGH LATE FRI AHEAD OF FRONT...UP TO 3 TO 5 FT. THE COOLER OCEAN WATERS COMPARED TO THE UNSEASONABLE WARM AIR TEMPS EXPECTED OVER LAND WILL PRODUCE STRONGER SEA BREEZES CAUSING A RISE IN BOTH WINDS AND SEAS WITH GUSTY NEAR SHORE WINDS. INCREASING S WINDS AND ELEVATED DEWPOINTS LATE THURSDAY OVER THE RELATIVELY COOLER INSHORE WATERS MAY PRODUCE PATCHY MARINE FOG PRIMARILY THURSDAY NIGHT. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 330 AM WEDNESDAY...COLD FRONT APPROACHING FROM THE NORTHWEST WILL REACH THE COAST SATURDAY MORNING AND SHOULD CROSS THE WATERS THROUGH THE MORNING HOURS. SW WINDS AHEAD OF FRONT UP TO 10 TO 15 KT WILL SHIFT AROUND TO N THROUGH SAT MORNING. HIGH PRESSURE WILL BUILD IN BEHIND COLD FRONT WITH WINDS VEERING SLIGHTLY THROUGH SUNDAY AS THE HIGH SHIFTS FARTHER EAST TOWARD THE COAST WHILE REMAINING NORTH OF LOCAL WATERS. SEAS UP TO 3 TO 5 FT AHEAD OF FRONT EARLY SAT WILL SUBSIDE IN OFF SHORE TO NORTHERLY FLOW THROUGH SAT AFTN DOWN TO 2 TO 4 FT BUT MAY SPIKE UP A LITTLE ON SUNDAY IN PERSISTENT NE FLOW. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...RJD SHORT TERM...RGZ LONG TERM...RGZ AVIATION...SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
650 AM EDT WED APR 8 2015 .SYNOPSIS...A MOIST AIR MASS AND SOUTHERLY FLOW WILL PERSIST OVER THE REGION TODAY THROUGH TONIGHT. A BACKDOOR COLD FRONT WILL DROP INTO NORTHEAST NORTH CAROLINA FROM THE NORTH LATE TONIGHT... THEN LIFT BACK NORTH LATE THURSDAY. A COLD FRONT WILL APPROACH THE REGION LATE FRIDAY. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 315 AM WEDNESDAY... TOUGH FORECAST THIS MORNING TRYING TO PINPOINT THE DETAILS OF EXPECTED CONVECTION. LATEST SURFACE ANALYSIS SHOWS A PROMINENT COLD FRONT FROM NRN OK THROUGH NRN MO... WITH A MORE DIFFUSE FRONTAL ZONE EXTENDING ACROSS IL AND THE OH VALLEY THEN SOUTHEAST THROUGH NRN/ERN VA. ISOLATED BUT STRONG AND ORGANIZED CONVECTION OVER SC INTO SE NC EARLIER TONIGHT IS EXITING BUT ADDITIONAL LESS-ORGANIZED SHOWERS AND ISOLATED STORMS ARE CLOSE BEHIND... THE DYING REMNANTS OF AN EARLIER MATURE COMPLEX THAT CROSSED KY LAST EVENING. THIS HAS MANIFESTED INTO A WEAK MCV THAT CAN BE DISCERNED IN RADAR AND WATER VAPOR IMAGERY CENTERED OVER WEST CENTRAL VA. THE LAST FEW HRRR MODEL RUNS REFLECTED BOTH OF THESE FEATURES BETTER THAN THE LARGER-SCALE MODELS WITH PARAMETERIZED CONVECTION (NOT A SURPRISE)... AND HAVE LARGELY FOLLOWED THIS SOLUTION FOR THE NEXT 12 HRS OR SO. EXPECT SCATTERED SHOWERS AND A FEW STORMS THROUGH MID MORNING... WITH THE BEST CHANCE SHIFTING TO NRN/ERN CWA NEAR AND SOON AFTER SUNRISE. WE SHOULD THEN SEE A PERIOD OF RELATIVE SUBSIDENCE FROM ROUGHLY LATE MORNING THROUGH MID AFTERNOON... AS THE VA MCV SHIFTS OFF THE COAST INDUCING SURFACE LOW FORMATION ALONG THE WEAK FRONTAL ZONE. AS THIS OCCURS... THE NORTHEAST FLOW ON THE BACKSIDE OF THIS LOW SHOULD HELP DRAW THE FRONTAL ZONE SOUTHWARD INTO NORTH CENTRAL/NE NC. THE LAST SEVERAL GFS RUNS HAVE TAKEN THIS FRONT MUCH FURTHER INTO NC THAN THE OTHER MODEL SOLUTIONS. WHILE THERE IS A CHILLY SURFACE HIGH CENTERED OVER QUEBEC NOSING SOUTHWARD OVER THE NORTHEAST STATES INTO THE NRN MIDATLANTIC REGION... THIS LOOKS TO BE CENTERED TOO FAR NORTH TO HAVE MUCH INFLUENCE ON THE FRONT THIS FAR SOUTH. EXPECT A WIND SHIFT TO NORTHEASTERLY OVER THE NE CWA WITH SLIGHTLY COOLER TEMPS MOVING IN LATE TODAY INTO TONIGHT... BUT THE COOLING SHOULDN`T BE THAT EXTREME. WILL FORECAST HIGHS TODAY IN THE LOW-MID 80S EXCEPT FOR MID- UPPER 70S IN THE FAR NE. ATTENTION THEN TURNS TO THE CONVECTION NOW ALONG THE FRONT OVER KS/MO/IA/IL AND THE POTENTIAL FOR ITS RESULTING MCV TO MOVE ESE ALONG THE FRONTAL ZONE INTO OUR REGION LATE TODAY INTO TONIGHT. THE GFS HINTS AT THIS... SHOWING SPOTTY MID LEVEL VORTICITY MAXIMA (LOOKING LIKE CONVECTIVE FEEDBACK) MOVING TO THE CENTRAL/SRN APPALACHIANS LATE TODAY INTO TONIGHT. IT MAKES SENSE THAT THIS WOULD TRIGGER CONVECTION ALONG AND EAST OF THE MOUNTAINS WHERE MODELS INDICATE MUCAPE OF 1500-2500 J/KG IN THE 21Z-06Z TIME FRAME WITH DEEP LAYER BULK SHEAR AROUND 30 KTS... STILL RATHER MODEST BUT ENOUGH TO SUSTAIN CONVECTION AS THE COLD POOL TRACKS ESE THROUGH NRN/ERN NC. WILL SHOW A PERIOD OF LOW POPS THROUGH MID AFTERNOON... FOLLOWED BY A RISE TO SCATTERED SHOWERS/STORMS LATE AFTERNOON THROUGH THIS EVENING... TRENDING DOWN OVERNIGHT AS THIS PERTURBATION EXITS TO OUR EAST. WITH THE FRONT STILL EXPECTED TO BE SITTING OVER THE NE CWA OVERNIGHT... WILL HAVE LOWS IN THE 60-65 RANGE EXCEPT FOR MID-UPPER 50S NE. -GIH && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... AS OF 330 AM WEDNESDAY... STRONG SURFACE LOW PRESSURE OVER THE CO/KS BORDER TODAY WILL REMAIN STRONG AS TRACKS ALONG THE FRONT TO SRN WI LATE THU AND NEAR SAULT STE MARIE BY DAYBREAK FRI. THE FRONTAL ZONE MEANWHILE BY LATE THU WILL EXTEND ACROSS SRN MI DOWN THROUGH WRN PA/VA THEN EASTWARD ALONG THE ERN VA/NC BORDER AREA. THE NAM/GFS SHOW DESTABILIZATION THU AFTERNOON INTO EARLY EVENING (THE NAM MORESO THAN THE GFS) ESPECIALLY OVER THE SW CWA SW OF THE FRONT WITH MUCAPE EXCEEDING 1500 J/KG... HOWEVER THE DEEP LAYER BULK SHEAR DECREASES TO LESS THAN 25 KTS... A REFLECTION OF THE DIGGING ENERGY OVER THE MIDWEST (LEADING TO THE STRONG SURFACE LOW) PROMPTING RISING HEIGHTS AND REDUCED MID LEVEL WINDS OVER THE CAROLINAS/SOUTHEAST STATES... AND THIS SHOULD REDUCE THE PROBABILITY FOR ANY STRONG TO SEVERE STORMS. WILL BRING IN CHANCE POPS FOR SHOWERS AND STORMS... FOCUSED MAINLY OVER THE NW HALF OF THE CWA... PEAKING DURING THE AFTERNOON INTO EARLY EVENING. EXPECT HIGHS FROM THE MID 70S NE TO LOWER 80S SW. WARM LOWS THU NIGHT IN THE MID 60S... WHICH WILL APPROACH RECORD HIGH MINIMUMS FOR APRIL 10TH. -GIH && LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 230 AM WEDNESDAY... THERE IS GROWING CONFIDENCE WITH REGARD TO A FRONTAL SYSTEM THAT IS PROGGED TO MOVE ACROSS THE CAROLINAS ON FRIDAY EVENING THROUGH SATURDAY MORNING. THIS WILL BE FOLLOWED BY WEAK RIDGING ALOFT AND SURFACE HIGH PRESSURE OVER THE MID ATLANTIC THROUGH THE WEEKEND. CONFIDENCE IN THE FORECAST TAKES A BIG TURN FOR THE WORSE BEGINNING ON MONDAY AS MODEL SOLUTIONS DIVERGE CONSIDERABLY. ABOUT THE ONLY THING THEY AGREE ON AT THIS POINT IS SOME KIND OF UPPER RIDGING OVER THE SOUTHEAST BUT EVEN THE POSITION AND TIMING OF THAT IS IN QUESTION AT THIS TIME. THE PROBLEMS EARLY NEXT WEEK STEM FROM A CUTOFF UPPER LEVEL LOW OVER TEXAS THAT FUNNELS MOISTURE OUT OF THE GULF AND OVER THE DEEP SOUTH BUT THERE ARE MASSIVE QUESTIONS IN TIMING AS THE ECMWF SOLUTION HAS PRECIPITATION REACHING CENTRAL NC BY MONDAY AFTERNOON AND THE GFS DOESN`T HAVE ANYTHING MEASURABLE OVER THE CWA UNTIL THURSDAY NIGHT. THAT QUALIFIES AS AN EXTREMELY LOW CONFIDENCE FORECAST AND WILL BE HANDLED AS SUCH. THEREFORE WILL MAINTAIN CHANCE POPS FROM MONDAY THROUGH THE END OF THE PERIOD. SHIFTING THE CONVERSATION FROM WHAT WE DON`T KNOW TO MORE OF WHAT WE DO KNOW REGARDING THE FRONTAL SYSTEM ON FRIDAY...SPC STILL HAS AN AREA OF 15% RISK OF SEVERE STORMS OVER ALL OF CENTRAL NC. AFTER A CLOSER LOOK AT THE FORECAST SOUNDINGS ON FRIDAY AFTERNOON...STORMS WILL BE INSTABILITY DRIVEN WITH THE SOUTHEASTERN PART OF THE CWA MOST LIKELY TO SEE STRONGER STORM ACTIVITY BUT THE POSSIBILITY WILL REMAIN EVERYWHERE. THE KFAY MODEL SOUNDINGS SHOW JUST OVER 1100 J/KG OF SURFACE BASED CAPE WITH 500 J/KG OCCURRING WITHIN THE HAIL GROWTH ZONE. THE HAIL THREAT LOOKS BETTER THAN THE WIND THREAT AT THIS TIME AS SHEAR IS MEAGER...ESPECIALLY IN THE LOW LEVELS. SOME INVERTED V SIGNATURES IN THE SOUNDING AND SOME RELATIVE DRYING AT THE 700 MB LEVEL COULD INCREASE THE POTENTIAL FOR SOME WET MICROBURSTS BUT OVERALL THE ENVIRONMENT FOR WIND OUTSIDE OF A LARGER HAIL CORE COLLAPSING IS LESS FAVORABLE AND VERY LOW AMOUNTS OF HELICITY SUGGEST TORNADOES WILL NOT BE LIKELY EITHER. OVERALL FEELING IS THAT SOME STRONGER STORMS WILL POP UP FRIDAY AFTERNOON BUT ANY SEVERE WILL BE FAIRLY ISOLATED. WORTH WATCHING TO SEE HOW IT EVOLVES OVER THE NEXT COUPLE OF DAYS. CONVECTION SHOULD PRODUCE DECENT QPF VALUES IN THE RANGE OF A QUARTER TO THREE QUARTERS OF AN INCH. PW VALUES ARE OVER AN INCH AND A HALF. FRIDAY WILL BE THE WARMEST DAY AHEAD OF THE FRONT WITH HIGHS IN THE MID 80S AND THEN TEMPS WILL COOL OFF AFTER THE FRONT PASSES WITH HIGH PRESSURE BRINGING IN COOL AIR FROM THE NORTH. EXPECT MOSTLY LOW TO MID 70S FOR HIGHS FOR THE REMAINDER OF THE PERIOD AFTER FRIDAY. LOWS IN THE LOWER 50S TO MID 60S. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AS OF 650 AM WEDNESDAY... PRIMARY AVIATION CONCERN NEXT 24 HRS: CHANCE OF MVFR OR IFR CIGS NOW THROUGH MID MORNING... WITH A FEW SHOWERS AND POSSIBLE ISOLATED STORMS. CONFIDENCE IS LOWER THAN USUAL REGARDING THE FORECAST THROUGH THIS MORNING. A VERY MOIST AIR MASS REMAINS IN PLACE FROM THE SURFACE UP THROUGH THE MID LEVELS (ABOVE 15 000 FT). CIGS ARE EXPECTED TO BE MAINLY IFR FOR ANOTHER FEW HOURS... BEFORE THEY RISE TO MVFR NEAR OR SOON AFTER 13Z THEN TO VFR BY AROUND 16Z... HOWEVER AS THESE LOW CLOUDS WILL VARY BETWEEN SCT AND BKN... FLIGHT CATEGORIES ARE LIKELY TO WAVER AMONG MVFR... IFR... AND VFR THIS MORNING. AVIATORS SHOULD REMAIN ALERT FOR THESE CHANGING CONDITIONS THIS MORNING. SCATTERED SHOWERS WILL AFFECT RDU/RWI/FAY THROUGH 16Z... BUT VSBYS SHOULD GO BE MAINLY MVFR IN THESE SHOWERS. AN ISOLATED STORM OR TWO IS POSSIBLE... ESPECIALLY AT RDU/RWI BEFORE 14Z. THERE IS A HIGH PROBABILITY OF VFR CONDITIONS FROM LATE MORNING THROUGH THE DAY... WITH VERY FEW IF ANY SHOWERS/STORMS AS WE SHOULD BE IN A RELATIVE LULL PERIOD BETWEEN CONVECTIVE SYSTEMS. A COUPLE OF MODELS HINT AT MORE STORMS ROLLING OVER THE CENTRAL/SRN APPALACHIANS THIS EVENING AND POTENTIALLY AFFECTING INT/GSO/RDU IN THE LAST 6-9 HRS OF THE TAF VALID PERIOD WITH BRIEF SUB-VFR CIGS/VSBYS AND GUSTY WINDS... HOWEVER CONFIDENCE IS NOT HIGH ENOUGH IN THE LOCATION AND TIMING OF ANY SUCH SYSTEM TO INCLUDE IN THE TAFS AT THIS TIME. WILL CONTINUE TO MONITOR. WE SHOULD SEE AREAS OF LOW CLOUDS AND FOG DEVELOP LATE TONIGHT ESPECIALLY AFFECTING RDU/RWI AS A BACKDOOR FRONT DROPS SOUTHWARD INTO THE NORTHEAST PORTION OF CENTRAL NC... WITH LIGHT SURFACE WINDS SHIFTING AROUND TO NORTHEASTERLY. LOOKING BEYOND 12Z EARLY THU MORNING... ANY LOW CLOUDS SHOULD LIFT TO VFR THU MORNING... REMAINING VFR THROUGH THU EVENING WITH A FEW SHOWERS/STORMS POSSIBLE THU AFTERNOON. AN APPROACHING COLD FRONT ON FRIDAY WILL BRING A GOOD CHANCE OF SUB-VFR CONDITIONS WITHIN SHOWERS AND STORMS FRI AFTERNOON AND EVENING. VFR CIGS/VSBYS ARE EXPECTED BEHIND THE FRONT LATE FRI NIGHT THROUGH SUN AS HIGH PRESSURE BUILDS IN. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...HARTFIELD LONG TERM...ELLIS AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
620 AM EDT WED APR 8 2015 .SYNOPSIS... A COLD FRONT WILL PUSH SOUTH INTO THE REGION LATE TODAY AND STALL OVER THE AREA TONIGHT. THE FRONT WILL LIFT NORTH OF THE REGION LATE THURSDAY. A COLD FRONT WILL APPROACH FROM THE WEST LATE FRIDAY AND MOVE OFFSHORE SATURDAY MORNING. HIGH PRESSURE WILL EXTEND OVER THE AREA FROM THE NORTH SATURDAY NIGHT AND SUNDAY. A WARM FRONT WILL LIFT NORTH OF THE AREA TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 620 AM WEDNESDAY...VERY DIFFICULT FORECAST NEXT 36 HOURS IN TRYING TO PROVIDE DETAIL REGARDING PRECIPITATION CHANCES IN THE MOIST BUT WEAKLY FORCED ATMOSPHERE OVER THE CAROLINAS. ZONAL FLOW WILL CONTINUE ALBEIT WITH RIDGING AND ASSOCIATED SUBTLE HEIGHT RISES OVER THE SOUTHEAST STATES THROUGH THURSDAY. WEAK LOW AMPLITUDE MID LEVEL WAVES IN THIS FLOW WILL HAVE THE POTENTIAL TO ENHANCE PRECIPITATION CHANCES ESPECIALLY IF THE ORGANIZED CONVECTION EXPECTED OVER THE PLAINS TODAY TRIGGERS A STRONGER MCV WHICH WOULD THEN MOVE EASTWARD TONIGHT. THE LARGE SCALE MODELS HAVE BEEN HAVING A DIFFICULT TIME IN HANDLING THIS SITUATION SO HAVE A RELIED ON THE HRRR AND THE HIGH RESOLUTION NMM AND WRF MODELS TO TRY TO GET A BETTER HANDLE ON THIS. 2 MAIN AREAS OF PRECIPITATION OCCURRING EARLY THIS MORNING. ONE ALONG THE IMMEDIATE COAST, ESPECIALLY THE ALBEMARLE SOUND REGION AND NORTHERN OUTER BANKS, AND ANOTHER MOVING INTO THE COASTAL PLAIN. THE HRRR MODEL BRINGS BOTH OF THESE AREAS ACROSS EASTERN NC TODAY MAINLY THIS MORNING THEN INDICATES A LULL IN THE PRECIPITATION THIS AFTERNOON AFTER 16Z. WILL BROADBRUSH THE FORECAST WITH 30-40% POPS DUE TO INHERENT UNCERTAINTY ESPECIALLY THIS AFTERNOON WHEN THE ATMOSPHERE BECOMES UNSTABLE AND A BACK DOOR COLD FRONT BEGINS TO DROP SOUTH INTO NORTHERN PORTIONS OF THE AREA DURING PEAK HEATING. TEMPERATURES WILL BE ABOVE NORMAL TODAY IN THE SOUTHERLY PRE FRONTAL FLOW WITH HIGHS INLAND IN THE LOWER 80S AND LOWER 70S BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/... AS OF 400 AM WEDNESDAY...THE BACK DOOR FRONT WILL SAG SOUTH TO NEAR THE CRYSTAL COAST OVERNIGHT THEN STALL. STILL UNCERTAIN ON PRECIPITATION DETAILS SO WILL FORECAST 30-50% POPS HIGHEST OUTER BANKS. LOWS ARE FORECAST TO CONTINUE MILD WITH READINGS IN THE UPPER 50S/LOWER 60S. && .LONG TERM /THURSDAY THROUGH TUESDAY/... AS OF 330 AM WEDNESDAY...00Z MODELS HAVE COME INTO BETTER AGREEMENT WITH BACKDOOR FRONT STALLING OVER SRN SECTIONS LATE WED NIGHT...THEN RETREATING NORTH ON THU. ECWMF AND GFS ALSO IN GOOD AGREEMENT THAT STRONGER COLD FRONT WILL MOVE IN FRIDAY NIGHT AND BE NEAR COAST SAT MORNING...THUS INCREASED POPS FRI NIGHT AND DECREASED INLAND SAT. THURSDAY AND THURSDAY NIGHT...SFC FRONT EXPECTED TO RETREAT NORTH DURING THE DAY WITH WEAK RIDGING ALOFT. LACK OF UPR SUPPORT EXPECTED TO LIMIT CONVECTIVE DEVELOPMENT BUT KEPT 20% POPS WITH FRONT MOVING BACK NORTH. DID DROP POPS FOR THU NIGHT WITH MODELS INDICATING PCPN THREAT WEST AND NORTH OF AREA. MOS GDNC CONTINUES TO HAVE LARGE DIFFERENCES ON HIGH TEMPS WITH GFS COOLER AND NAM WARMER DUE TO HANDLING OF FRONT. UPDATED PREVIOUS FCST WITH LEAN TO COOLER GFS...HIGHS RANGING FROM AROUND 80 SOUTH TO 65-70 NORTH. FRIDAY THROUGH SATURDAY...VERY WARM TEMPS EXPECTED FRIDAY AHEAD OF A STRONGER COLD FRONT APPROACHING FRIDAY NIGHT. NO CHANGE TO PREVIOUS THINKING FOR SHOWERS AND THUNDERSTORMS FRIDAY FOR INLAND SECTIONS AS DECENT INSTABILITY AND UNIDIRECTIONAL WEST-SOUTHWEST FLOW IS ENOUGH TO SUPPORT CHC POPS IN AFTERNOON INLAND OF SEA BREEZE. LOW LEVEL THICKNESSES SUPPORT MID 80S FOR INLAND SECTIONS. LATEST MODELS AGREE ON MAIN THREAT OF SHOWERS AND TSTMS ALONG AND AHEAD OF COLD FRONT FRIDAY NIGHT...AND INCREASED POPS TO 60% ALL ZONES...MAINLY FOR WRN HALF DURING EVENING AND ERN HALF OVERNIGHT. CONCUR WITH SPC OUTLOOK OF SLIGHT RISK OF SVR WITH SUFFICIENT MID LVL SHEAR TO SUPPORT ORGANIZED STRONG CONVECTION. FRONT EXPECTED TO MOVE OFFSHORE SAT MORNING AND HAVE LOWERED POPS TO INDICATE DRIER TREND. MAX TEMPS ABOUT 10 DEGS COOLER THAN FRIDAY WITH MID 70S INLAND TO LOWER 60S NRN OBX. SATURDAY NIGHT THROUGH SUNDAY NIGHT...STRONG HIGH PRES WILL EXTEND OVER AREA FROM NORTH SAT NIGHT AND SUNDAY AND GRADUALLY MOVE EAST SUN NIGHT. DRY CONDITIONS EXPECTED WITH TEMPS NEAR NORMAL. MONDAY INTO TUESDAY...NO CHANGE TO PREVIOUS FCST. HIGH PRES WILL CONTINUE MOVING OFFSHORE WITH MOIST S TO SW FLOW RETURNING. SLIGHT CHC POPS FOR SW HALF OF AREA MONDAY AND MON NIGHT...INCREASING TO 20-30% ALL AREAS TUESDAY. MAIN TEMP CHANGE WILL BE MIN TEMPS 10-15 DEGS ABOVE NORMAL MON NIGHT. && .AVIATION /10Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM /THROUGH TONIGHT/... AS OF 620 AM WEDNESDAY...DIFFICULT FORECAST WITH CONVECTIVE DEBRIS CLOUDS AND MIXING LIMITING RADIATIONAL COOLING AT TIMES THIS MORNING...AND PRECIPITATION APPROACHING THE TAF SITES FROM THE WEST. THE MOSTLY LIGHT PRECIPITATION WILL AFFECT THE TAF SITES ON AND OFF THROUGH ABOUT 16Z WITH BRIEF MVFR CONDITIONS POSSIBLE IN HEAVIER SHOWERS. THREAT NOT LOOKING AS WIDESPREAD AS EARLIER AND SHOULD END BY 14Z. VFR CONDITIONS EXPECTED OUTSIDE OF SCATTERED SHOWER/THUNDERSTORM ACTIVITY THROUGH THIS EVENING. GUIDANCE IS AGAIN POINTING TO THE POTENTIAL FOR IFR CONDITIONS REDEVELOPING AGAIN LATE THIS EVENING AS THE BL REMAINS SATURATED BUT CONFIDENCE IN THIS LOW DUE TO RECENT TENDENCY FOR GUIDANCE TO OVER FORECAST THESE CONDITIONS. LOW LEVEL EASTERLY FLOW BEHIND THE BACK DOOR FRONT MAY BE MORE CONDUCIVE TO IFR CONDITIONS THOUGH SO WILL HAVE TO CONTINUE TO MONITOR. LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 400 AM WEDNESDAY...SOME LOWER CIGS COULD PERSIST THURS MORNING WITH LOW LEVEL NE FLOW. VFR MAINLY EXPECTED THURS NIGHT INTO FRIDAY...THEN HIGHER THREAT OF SUB-VFR CONDITIONS FRI NIGHT INTO EARLY SAT WITH GOOD COVERAGE OF SHOWERS AND TSTMS EXPECTED AS STRONGER FRONT MOVES INTO AREA. GUSTY SW WINDS 15-25 MPH LIKELY FRIDAY AHEAD OF FRONT. HIGH PRESSURE WILL ALLOW AVIATION CONDITIONS TO IMPROVE TO VFR SATURDAY EVENING THROUGH SUNDAY. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 620 AM WEDNESDAY...WINDS WILL REMAIN 15 KT OR LESS THROUGH TONIGHT. THE MAIN FEATURE WILL BE A BACK DOOR COLD FRONT WHICH IS FORECAST TO PUSH SOUTH INTO THE NORTHERN WATERS/ALBEMARLE SOUND TODAY THEN CONTINUE SOUTH TONIGHT INTO THE CENTRAL WATERS/PAMLICO SOUND WHERE IT WILL STALL. EXPECT WINDS TO VEER FROM SOUTHERLY THIS MORNING TO SOUTHWEST TO WEST BY THIS AFTERNOON THEN TO NORTH AND NORTHEAST BEHIND THE FRONT LATER TODAY AND TONIGHT. SEAS WILL REMAIN IN THE 2-4 FT RANGE THROUGH THE PERIOD. LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 400 AM WEDNESDAY...CONTINUED PREVIOUS FCST THINKING WITH WINDS GRADUALLY RETURNING TO S-SW DURING THE DAY THU AS FRONT RETREATS BACK NORTH. MAIN CHANGE WAS TO INDICATE FASTER COLD FRONT PASSAGE SAT MORNING WITH LATEST MODELS IN GOOD AGREEMENT. STILL EXPECT STRONGEST WINDS FRI AND FRI NIGHT AHEAD OF FRONT...SW 15-25 KT WITH SEAS BUILDING TO SMALL CRAFT ADVISORY LEVELS FRI AFTN INTO EARLY SAT. NE SURGE 10-20 KT EXPECTED LATE SAT THROUGH SUNDAY. ADJUSTED SEAS WITH LATEST NWPS. HEIGHTS MAINLY 3-4 FT THU...BUILDING TO 4-6 FT FRI-FRI NIGHT...THEN DIMINISHING 2-4 FT SUNDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JME NEAR TERM...JME SHORT TERM...JME LONG TERM...JBM AVIATION...JME/JBM MARINE...JME/JBM
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
447 AM EDT WED APR 8 2015 .SYNOPSIS... A COLD FRONT WILL PUSH SOUTH INTO THE REGION LATE TODAY AND STALL OVER THE AREA TONIGHT. THE FRONT WILL LIFT NORTH OF THE REGION LATE THURSDAY. A COLD FRONT WILL APPROACH FROM THE WEST LATE FRIDAY AND MOVE OFFSHORE SATURDAY MORNING. HIGH PRESSURE WILL EXTEND OVER THE AREA FROM THE NORTH SATURDAY NIGHT AND SUNDAY. A WARM FRONT WILL LIFT NORTH OF THE AREA TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 400 AM WEDNESDAY...VERY DIFFICULT FORECAST NEXT 36 HOURS IN TRYING TO PROVIDE DETAIL ON PRECIPITATION CHANCES IN THE MOIST BUT WEAKLY FORCED ATMOSPHERE OVER THE CAROLINAS. ZONAL FLOW WILL CONTINUE ALBEIT WITH RIDGING AND ASSOCIATED SUBTLE HEIGHT RISES OVER THE SOUTHEAST STATES THROUGH THURSDAY. WEAK LOW AMPLITUDE MID LEVEL WAVES IN THIS FLOW WILL HAVE THE POTENTIAL TO ENHANCE PRECIPITATION CHANCES ESPECIALLY IF THE ORGANIZED CONVECTION EXPECTED OVER THE PLAINS TODAY TRIGGERS A MCV WHICH WOULD THEN MOVE EASTWARD TONIGHT. THE LARGE SCALE MODELS HAVE BEEN HAVING A DIFFICULT TIME IN HANDLING THIS SITUATION SO HAVE A RELAYED ON THE HRRR AND THE HIGH RESOLUTION NMM AND WRF MODELS TO TRY TO GET A BETTER HANDLE ON THIS. 2 MAIN AREAS OF PRECIPITATION OCCURRING EARLY THIS MORNING. ONE OVER THE COASTAL PLAIN AND ANOTHER MOVING INTO PIEDMONT. THE HRRR MODEL BRINGS BOTH OF THESE AREAS ACROSS EASTERN NC TODAY MAINLY THIS MORNING THEN INDICATES A LULL IN THE PRECIPITATION THIS AFTERNOON. WILL BROADBRUSH THE FORECAST WITH 30-40% POPS DUE TO INHERENT UNCERTAINTY ESPECIALLY THIS AFTERNOON WHEN THE ATMOSPHERE BECOMES UNSTABLE AND A BACK DOOR COLD FRONT BEGINS TO DROP SOUTH INTO NORTHERN PORTIONS OF THE AREA DURING PEAK HEATING. TEMPERATURES WILL BE ABOVE NORMAL TODAY IN THE SOUTHERLY PRE FRONTAL FLOW WITH HIGHS INLAND IN THE LOWER 80S AND LOWER 70S BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/... AS OF 400 AM WEDNESDAY...THE BACK DOOR FRONT WILL SAG SOUTH TO NEAR THE CRYSTAL COAST THEN STALL. STILL UNCERTAIN ON PRECIPITATION DETAILS SO WILL FORECAST 30-50% POPS HIGHEST OUTER BANKS. LOWS ARE FORECAST TO CONTINUE MILD WITH READINGS IN THE UPPER 50S/LOWER 60S. && .LONG TERM /THURSDAY THROUGH TUESDAY/... AS OF 330 AM WEDNESDAY...00Z MODELS HAVE COME INTO BETTER AGREEMENT WITH BACKDOOR FRONT STALLING OVER SRN SECTIONS LATE WED NIGHT...THEN RETREATING NORTH ON THU. ECWMF AND GFS ALSO IN GOOD AGREEMENT THAT STRONGER COLD FRONT WILL MOVE IN FRIDAY NIGHT AND BE NEAR COAST SAT MORNING...THUS INCREASED POPS FRI NIGHT AND DECREASED INLAND SAT. THURSDAY AND THURSDAY NIGHT...SFC FRONT EXPECTED TO RETREAT NORTH DURING THE DAY WITH WEAK RIDGING ALOFT. LACK OF UPR SUPPORT EXPECTED TO LIMIT CONVECTIVE DEVELOPMENT BUT KEPT 20% POPS WITH FRONT MOVING BACK NORTH. DID DROP POPS FOR THU NIGHT WITH MODELS INDICATING PCPN THREAT WEST AND NORTH OF AREA. MOS GDNC CONTINUES TO HAVE LARGE DIFFERENCES ON HIGH TEMPS WITH GFS COOLER AND NAM WARMER DUE TO HANDLING OF FRONT. UPDATED PREVIOUS FCST WITH LEAN TO COOLER GFS...HIGHS RANGING FROM AROUND 80 SOUTH TO 65-70 NORTH. FRIDAY THROUGH SATURDAY...VERY WARM TEMPS EXPECTED FRIDAY AHEAD OF A STRONGER COLD FRONT APPROACHING FRIDAY NIGHT. NO CHANGE TO PREVIOUS THINKING FOR SHOWERS AND THUNDERSTORMS FRIDAY FOR INLAND SECTIONS AS DECENT INSTABILITY AND UNIDIRECTIONAL WEST-SOUTHWEST FLOW IS ENOUGH TO SUPPORT CHC POPS IN AFTERNOON INLAND OF SEA BREEZE. LOW LEVEL THICKNESSES SUPPORT MID 80S FOR INLAND SECTIONS. LATEST MODELS AGREE ON MAIN THREAT OF SHOWERS AND TSTMS ALONG AND AHEAD OF COLD FRONT FRIDAY NIGHT...AND INCREASED POPS TO 60% ALL ZONES...MAINLY FOR WRN HALF DURING EVENING AND ERN HALF OVERNIGHT. CONCUR WITH SPC OUTLOOK OF SLIGHT RISK OF SVR WITH SUFFICIENT MID LVL SHEAR TO SUPPORT ORGANIZED STRONG CONVECTION. FRONT EXPECTED TO MOVE OFFSHORE SAT MORNING AND HAVE LOWERED POPS TO INDICATE DRIER TREND. MAX TEMPS ABOUT 10 DEGS COOLER THAN FRIDAY WITH MID 70S INLAND TO LOWER 60S NRN OBX. SATURDAY NIGHT THROUGH SUNDAY NIGHT...STRONG HIGH PRES WILL EXTEND OVER AREA FROM NORTH SAT NIGHT AND SUNDAY AND GRADUALLY MOVE EAST SUN NIGHT. DRY CONDITIONS EXPECTED WITH TEMPS NEAR NORMAL. MONDAY INTO TUESDAY...NO CHANGE TO PREVIOUS FCST. HIGH PRES WILL CONTINUE MOVING OFFSHORE WITH MOIST S TO SW FLOW RETURNING. SLIGHT CHC POPS FOR SW HALF OF AREA MONDAY AND MON NIGHT...INCREASING TO 20-30% ALL AREAS TUESDAY. MAIN TEMP CHANGE WILL BE MIN TEMPS 10-15 DEGS ABOVE NORMAL MON NIGHT. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM /THROUGH TONIGHT/... AS OF 1245 AM WEDNESDAY...DIFFICULT FORECAST WITH CONVECTIVE DEBRIS CLOUDS AND MIXING LIMITING RADIATIONAL COOLING AT TIMES...AND PRECIPITATION APPROACHING THE TAF SITES FROM THE WEST. THE PRECIPITATION WILL AFFECT ALL OF THE TAF SITES LATE TONIGHT INTO WEDNESDAY MORNING ESPECIALLY KOAJ AND KEWN BUT SHOULD BE MOSTLY LIGHT WITH BRIEF MVFR CONDITIONS. OUTSIDE OF THE PRECIPITATION FORECAST SOUNDINGS INDICATED A SATURATED BOUNDARY LAYER WHICH WILL LEAD TO FOG AND OR LOW STRATUS CLOUDS. NEW BERN HAS DECOUPLED AS HAS RICHLANDS SO THESE AREAS HAVE THE BEST POTENTIAL FOR IFR FOG OVERNIGHT AS THE GUIDANCE INDICATES THAT KPGV AND KISO MAY REMAIN MIXED. HOWEVER THE HRRR AND NARRE GUIDANCE IS INDICATING IFR CEILINGS ALL TAF SITES BY 09Z SO EXPECTING POOR CONDITIONS OVERNIGHT EARLY WEDNESDAY FOR AT LEAST SEVERAL HOURS AT ALL OF THE TAF SITES. CONDITIONS SHOULD IMPROVE TO VFR LATE WEDNESDAY MORNING AND AFTERNOON OUTSIDE OF ANY SCATTERED SHOWER/THUNDERSTORM ACTIVITY THAT DEVELOPS. GUIDANCE IS AGAIN POINTING TO THE POTENTIAL FOR IFR CONDITIONS REDEVELOPING AGAIN WEDNESDAY EVENING AS THE BL REMAINS SATURATED. LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 400 AM WEDNESDAY...SOME LOWER CIGS COULD PERSIST THURS MORNING WITH LOW LEVEL NE FLOW. VFR MAINLY EXPECTED THURS NIGHT INTO FRIDAY...THEN HIGHER THREAT OF SUB-VFR CONDITIONS FRI NIGHT INTO EARLY SAT WITH GOOD COVERAGE OF SHOWERS AND TSTMS EXPECTED AS STRONGER FRONT MOVES INTO AREA. GUSTY SW WINDS 15-25 MPH LIKELY FRIDAY AHEAD OF FRONT. HIGH PRESSURE WILL ALLOW AVIATION CONDITIONS TO IMPROVE TO VFR SATURDAY EVENING THROUGH SUNDAY. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 400 AM WEDNESDAY...WINDS WILL REMAIN 15 KT OR LESS THROUGH TONIGHT. THE MAIN FEATURE WILL BE A BACK DOOR COLD FRONT WHICH IS FORECAST TO PUSH SOUTH INTO THE NORTHERN WATERS/ALBEMARLE SOUND LATE TODAY THEN CONTINUE SOUTH TONIGHT INTO THE CENTRAL WATERS/PAMLICO SOUND WHERE IT WILL SATLL. EXPECT WINDS TO VEER FROM SOUTHERLY THIS MORNING TO SOUTHWEST TO WEST THIS AFTERNOON THEN TO NORTH AND NORTHEAST BEHIND THE FRONT LATE TODAY AND TONIGHT. SEAS WILL REMAIN IN THE 2-4 FT RANGE THROUGH THE PERIOD. LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 400 AM WEDNESDAY...CONTINUED PREVIOUS FCST THINKING WITH WINDS GRADUALLY RETURNING TO S-SW DURING THE DAY THU AS FRONT RETREATS BACK NORTH. MAIN CHANGE WAS TO INDICATE FASTER COLD FRONT PASSAGE SAT MORNING WITH LATEST MODELS IN GOOD AGREEMENT. STILL EXPECT STRONGEST WINDS FRI AND FRI NIGHT AHEAD OF FRONT...SW 15-25 KT WITH SEAS BUILDING TO SMALL CRAFT ADVISORY LEVELS FRI AFTN INTO EARLY SAT. NE SURGE 10-20 KT EXPECTED LATE SAT THROUGH SUNDAY. ADJUSTED SEAS WITH LATEST NWPS. HEIGHTS MAINLY 3-4 FT THU...BUILDING TO 4-6 FT FRI-FRI NIGHT...THEN DIMINISHING 2-4 FT SUNDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JME NEAR TERM...JME SHORT TERM...JME LONG TERM...JBM AVIATION...JME/JBM MARINE...JME/JBM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 AM EDT WED APR 8 2015 .SYNOPSIS...A MOIST AIR MASS AND SOUTHERLY FLOW WILL PERSIST OVER THE REGION TODAY THROUGH TONIGHT. A BACKDOOR COLD FRONT WILL DROP INTO NORTHEAST NORTH CAROLINA FROM THE NORTH LATE TONIGHT... THEN LIFT BACK NORTH LATE THURSDAY. A COLD FRONT WILL APPROACH THE REGION LATE FRIDAY. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 315 AM WEDNESDAY... TOUGH FORECAST THIS MORNING TRYING TO PINPOINT THE DETAILS OF EXPECTED CONVECTION. LATEST SURFACE ANALYSIS SHOWS A PROMINENT COLD FRONT FROM NRN OK THROUGH NRN MO... WITH A MORE DIFFUSE FRONTAL ZONE EXTENDING ACROSS IL AND THE OH VALLEY THEN SOUTHEAST THROUGH NRN/ERN VA. ISOLATED BUT STRONG AND ORGANIZED CONVECTION OVER SC INTO SE NC EARLIER TONIGHT IS EXITING BUT ADDITIONAL LESS-ORGANIZED SHOWERS AND ISOLATED STORMS ARE CLOSE BEHIND... THE DYING REMNANTS OF AN EARLIER MATURE COMPLEX THAT CROSSED KY LAST EVENING. THIS HAS MANIFESTED INTO A WEAK MCV THAT CAN BE DISCERNED IN RADAR AND WATER VAPOR IMAGERY CENTERED OVER WEST CENTRAL VA. THE LAST FEW HRRR MODEL RUNS REFLECTED BOTH OF THESE FEATURES BETTER THAN THE LARGER-SCALE MODELS WITH PARAMETERIZED CONVECTION (NOT A SURPRISE)... AND HAVE LARGELY FOLLOWED THIS SOLUTION FOR THE NEXT 12 HRS OR SO. EXPECT SCATTERED SHOWERS AND A FEW STORMS THROUGH MID MORNING... WITH THE BEST CHANCE SHIFTING TO NRN/ERN CWA NEAR AND SOON AFTER SUNRISE. WE SHOULD THEN SEE A PERIOD OF RELATIVE SUBSIDENCE FROM ROUGHLY LATE MORNING THROUGH MID AFTERNOON... AS THE VA MCV SHIFTS OFF THE COAST INDUCING SURFACE LOW FORMATION ALONG THE WEAK FRONTAL ZONE. AS THIS OCCURS... THE NORTHEAST FLOW ON THE BACKSIDE OF THIS LOW SHOULD HELP DRAW THE FRONTAL ZONE SOUTHWARD INTO NORTH CENTRAL/NE NC. THE LAST SEVERAL GFS RUNS HAVE TAKEN THIS FRONT MUCH FURTHER INTO NC THAN THE OTHER MODEL SOLUTIONS. WHILE THERE IS A CHILLY SURFACE HIGH CENTERED OVER QUEBEC NOSING SOUTHWARD OVER THE NORTHEAST STATES INTO THE NRN MIDATLANTIC REGION... THIS LOOKS TO BE CENTERED TOO FAR NORTH TO HAVE MUCH INFLUENCE ON THE FRONT THIS FAR SOUTH. EXPECT A WIND SHIFT TO NORTHEASTERLY OVER THE NE CWA WITH SLIGHTLY COOLER TEMPS MOVING IN LATE TODAY INTO TONIGHT... BUT THE COOLING SHOULDN`T BE THAT EXTREME. WILL FORECAST HIGHS TODAY IN THE LOW-MID 80S EXCEPT FOR MID- UPPER 70S IN THE FAR NE. ATTENTION THEN TURNS TO THE CONVECTION NOW ALONG THE FRONT OVER KS/MO/IA/IL AND THE POTENTIAL FOR ITS RESULTING MCV TO MOVE ESE ALONG THE FRONTAL ZONE INTO OUR REGION LATE TODAY INTO TONIGHT. THE GFS HINTS AT THIS... SHOWING SPOTTY MID LEVEL VORTICITY MAXIMA (LOOKING LIKE CONVECTIVE FEEDBACK) MOVING TO THE CENTRAL/SRN APPALACHIANS LATE TODAY INTO TONIGHT. IT MAKES SENSE THAT THIS WOULD TRIGGER CONVECTION ALONG AND EAST OF THE MOUNTAINS WHERE MODELS INDICATE MUCAPE OF 1500-2500 J/KG IN THE 21Z-06Z TIME FRAME WITH DEEP LAYER BULK SHEAR AROUND 30 KTS... STILL RATHER MODEST BUT ENOUGH TO SUSTAIN CONVECTION AS THE COLD POOL TRACKS ESE THROUGH NRN/ERN NC. WILL SHOW A PERIOD OF LOW POPS THROUGH MID AFTERNOON... FOLLOWED BY A RISE TO SCATTERED SHOWERS/STORMS LATE AFTERNOON THROUGH THIS EVENING... TRENDING DOWN OVERNIGHT AS THIS PERTURBATION EXITS TO OUR EAST. WITH THE FRONT STILL EXPECTED TO BE SITTING OVER THE NE CWA OVERNIGHT... WILL HAVE LOWS IN THE 60-65 RANGE EXCEPT FOR MID-UPPER 50S NE. -GIH && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... AS OF 330 AM WEDNESDAY... STRONG SURFACE LOW PRESSURE OVER THE CO/KS BORDER TODAY WILL REMAIN STRONG AS TRACKS ALONG THE FRONT TO SRN WI LATE THU AND NEAR SAULT STE MARIE BY DAYBREAK FRI. THE FRONTAL ZONE MEANWHILE BY LATE THU WILL EXTEND ACROSS SRN MI DOWN THROUGH WRN PA/VA THEN EASTWARD ALONG THE ERN VA/NC BORDER AREA. THE NAM/GFS SHOW DESTABILIZATION THU AFTERNOON INTO EARLY EVENING (THE NAM MORESO THAN THE GFS) ESPECIALLY OVER THE SW CWA SW OF THE FRONT WITH MUCAPE EXCEEDING 1500 J/KG... HOWEVER THE DEEP LAYER BULK SHEAR DECREASES TO LESS THAN 25 KTS... A REFLECTION OF THE DIGGING ENERGY OVER THE MIDWEST (LEADING TO THE STRONG SURFACE LOW) PROMPTING RISING HEIGHTS AND REDUCED MID LEVEL WINDS OVER THE CAROLINAS/SOUTHEAST STATES... AND THIS SHOULD REDUCE THE PROBABILITY FOR ANY STRONG TO SEVERE STORMS. WILL BRING IN CHANCE POPS FOR SHOWERS AND STORMS... FOCUSED MAINLY OVER THE NW HALF OF THE CWA... PEAKING DURING THE AFTERNOON INTO EARLY EVENING. EXPECT HIGHS FROM THE MID 70S NE TO LOWER 80S SW. WARM LOWS THU NIGHT IN THE MID 60S... WHICH WILL APPROACH RECORD HIGH MINIMUMS FOR APRIL 10TH. -GIH && LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 230 AM WEDNESDAY... THERE IS GROWING CONFIDENCE WITH REGARD TO A FRONTAL SYSTEM THAT IS PROGGED TO MOVE ACROSS THE CAROLINAS ON FRIDAY EVENING THROUGH SATURDAY MORNING. THIS WILL BE FOLLOWED BY WEAK RIDGING ALOFT AND SURFACE HIGH PRESSURE OVER THE MID ATLANTIC THROUGH THE WEEKEND. CONFIDENCE IN THE FORECAST TAKES A BIG TURN FOR THE WORSE BEGINNING ON MONDAY AS MODEL SOLUTIONS DIVERGE CONSIDERABLY. ABOUT THE ONLY THING THEY AGREE ON AT THIS POINT IS SOME KIND OF UPPER RIDGING OVER THE SOUTHEAST BUT EVEN THE POSITION AND TIMING OF THAT IS IN QUESTION AT THIS TIME. THE PROBLEMS EARLY NEXT WEEK STEM FROM A CUTOFF UPPER LEVEL LOW OVER TEXAS THAT FUNNELS MOISTURE OUT OF THE GULF AND OVER THE DEEP SOUTH BUT THERE ARE MASSIVE QUESTIONS IN TIMING AS THE ECMWF SOLUTION HAS PRECIPITATION REACHING CENTRAL NC BY MONDAY AFTERNOON AND THE GFS DOESN`T HAVE ANYTHING MEASURABLE OVER THE CWA UNTIL THURSDAY NIGHT. THAT QUALIFIES AS AN EXTREMELY LOW CONFIDENCE FORECAST AND WILL BE HANDLED AS SUCH. THEREFORE WILL MAINTAIN CHANCE POPS FROM MONDAY THROUGH THE END OF THE PERIOD. SHIFTING THE CONVERSATION FROM WHAT WE DON`T KNOW TO MORE OF WHAT WE DO KNOW REGARDING THE FRONTAL SYSTEM ON FRIDAY...SPC STILL HAS AN AREA OF 15% RISK OF SEVERE STORMS OVER ALL OF CENTRAL NC. AFTER A CLOSER LOOK AT THE FORECAST SOUNDINGS ON FRIDAY AFTERNOON...STORMS WILL BE INSTABILITY DRIVEN WITH THE SOUTHEASTERN PART OF THE CWA MOST LIKELY TO SEE STRONGER STORM ACTIVITY BUT THE POSSIBILITY WILL REMAIN EVERYWHERE. THE KFAY MODEL SOUNDINGS SHOW JUST OVER 1100 J/KG OF SURFACE BASED CAPE WITH 500 J/KG OCCURRING WITHIN THE HAIL GROWTH ZONE. THE HAIL THREAT LOOKS BETTER THAN THE WIND THREAT AT THIS TIME AS SHEAR IS MEAGER...ESPECIALLY IN THE LOW LEVELS. SOME INVERTED V SIGNATURES IN THE SOUNDING AND SOME RELATIVE DRYING AT THE 700 MB LEVEL COULD INCREASE THE POTENTIAL FOR SOME WET MICROBURSTS BUT OVERALL THE ENVIRONMENT FOR WIND OUTSIDE OF A LARGER HAIL CORE COLLAPSING IS LESS FAVORABLE AND VERY LOW AMOUNTS OF HELICITY SUGGEST TORNADOES WILL NOT BE LIKELY EITHER. OVERALL FEELING IS THAT SOME STRONGER STORMS WILL POP UP FRIDAY AFTERNOON BUT ANY SEVERE WILL BE FAIRLY ISOLATED. WORTH WATCHING TO SEE HOW IT EVOLVES OVER THE NEXT COUPLE OF DAYS. CONVECTION SHOULD PRODUCE DECENT QPF VALUES IN THE RANGE OF A QUARTER TO THREE QUARTERS OF AN INCH. PW VALUES ARE OVER AN INCH AND A HALF. FRIDAY WILL BE THE WARMEST DAY AHEAD OF THE FRONT WITH HIGHS IN THE MID 80S AND THEN TEMPS WILL COOL OFF AFTER THE FRONT PASSES WITH HIGH PRESSURE BRINGING IN COOL AIR FROM THE NORTH. EXPECT MOSTLY LOW TO MID 70S FOR HIGHS FOR THE REMAINDER OF THE PERIOD AFTER FRIDAY. LOWS IN THE LOWER 50S TO MID 60S. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 110 AM WEDNESDAY... PRIMARY AVIATION CONCERN NEXT 24 HRS: CHANCE OF MVFR OR IFR CIGS NOW THROUGH MID MORNING WITH A FEW SHOWERS AND POSSIBLE ISOLATED STORMS. CONFIDENCE IS LOWER THAN USUAL REGARDING THE FORECAST THROUGH THIS MORNING. A VERY MOIST AIR MASS REMAINS IN PLACE FROM THE SURFACE UP THROUGH THE MID LEVELS (ABOVE 15 000 FT). FLIGHT CATEGORIES ARE LIKELY TO WAVER AMONG MVFR... IFR... AND VFR THIS MORNING... HOWEVER EXPECT VFR CONDITIONS TO OCCUR MOST OF THE TIME THROUGH MID MORNING. AVIATORS SHOULD REMAIN ALERT FOR POCKETS OF SUB-VFR CIGS... AS THEY ARE LIKELY TO HAPPEN BUT DIFFICULT TO PINPOINT. SCATTERED SHOWERS WILL AFFECT CENTRAL NC THROUGH THE FIRST 6-9 HRS OF THE TAF VALID PERIOD... BUT VSBYS SHOULD REMAIN MAINLY VFR WITH THESE... ONLY BRIEFLY DROPPING TO MVFR FOR LESS THAN A HALF HOUR AT A TIME. MODELS HAVE HAD DIFFICULTY WITH RECENT AND CURRENT CONDITIONS HERE AND UPSTREAM... BUT ALL AGREE ON A HIGH PROBABILITY OF VFR CONDITIONS FROM LATE MORNING THROUGH THE DAY... WITH VERY FEW IF ANY SHOWERS/STORMS AS WE SHOULD BE IN A RELATIVE LULL PERIOD BETWEEN CONVECTIVE SYSTEMS. A COUPLE OF MODELS HINT AT MORE STORMS ROLLING OVER THE CENTRAL/SRN APPALACHIANS THIS EVENING AND POTENTIALLY AFFECTING INT/GSO/RDU TOWARD THE END OF THE TAF VALID PERIOD WITH BRIEF SUB-VFR CIGS/VSBYS AND GUSTY WINDS... HOWEVER CONFIDENCE IS NOT HIGH ENOUGH IN THE LOCATION AND TIMING OF ANY SUCH SYSTEM TO INCLUDE IN THE TAFS AT THIS TIME. WILL CONTINUE TO MONITOR. LOOKING BEYOND 06Z EARLY THU MORNING... MAY NEED TO INCLUDE A CHANCE FOR SUB-VFR SHOWERS/STORMS INTO THE OVERNIGHT HOURS. OTHERWISE... WE SHOULD SEE AREAS OF LOW CLOUDS AND FOG DEVELOP ESPECIALLY AFFECTING RDU/RWI AS A BACKDOOR FRONT DROPS SOUTHWARD INTO THE NORTHEAST PORTION OF CENTRAL NC... WITH LIGHT SURFACE WINDS SHIFTING AROUND TO NORTHEASTERLY. ANY LOW CLOUDS SHOULD LIFT TO VFR THU MORNING... REMAINING VFR THROUGH THU EVENING WITH A FEW SHOWERS/STORMS POSSIBLE THU AFTERNOON. AN APPROACHING COLD FRONT ON FRIDAY WILL BRING A GOOD CHANCE OF SUB-VFR CONDITIONS WITHIN SHOWERS AND STORMS FRI AFTERNOON AND EVENING. VFR CIGS/VSBYS ARE EXPECTED BEHIND THE FRONT LATE FRI NIGHT THROUGH SUN AS HIGH PRESSURE BUILDS IN. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...HARTFIELD LONG TERM...ELLIS AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
315 AM EDT WED APR 8 2015 .SYNOPSIS...A MOIST AIR MASS AND SOUTHERLY FLOW WILL PERSIST OVER THE REGION TODAY THROUGH TONIGHT. A BACKDOOR COLD FRONT WILL DROP INTO NORTHEAST NORTH CAROLINA FROM THE NORTH LATE TONIGHT... THEN LIFT BACK NORTH LATE THURSDAY. A COLD FRONT WILL APPROACH THE REGION LATE FRIDAY. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 315 AM WEDNESDAY... TOUGH FORECAST THIS MORNING TRYING TO PINPOINT THE DETAILS OF EXPECTED CONVECTION. LATEST SURFACE ANALYSIS SHOWS A PROMINENT COLD FRONT FROM NRN OK THROUGH NRN MO... WITH A MORE DIFFUSE FRONTAL ZONE EXTENDING ACROSS IL AND THE OH VALLEY THEN SOUTHEAST THROUGH NRN/ERN VA. ISOLATED BUT STRONG AND ORGANIZED CONVECTION OVER SC INTO SE NC EARLIER TONIGHT IS EXITING BUT ADDITIONAL LESS-ORGANIZED SHOWERS AND ISOLATED STORMS ARE CLOSE BEHIND... THE DYING REMNANTS OF AN EARLIER MATURE COMPLEX THAT CROSSED KY LAST EVENING. THIS HAS MANIFESTED INTO A WEAK MCV THAT CAN BE DISCERNED IN RADAR AND WATER VAPOR IMAGERY CENTERED OVER WEST CENTRAL VA. THE LAST FEW HRRR MODEL RUNS REFLECTED BOTH OF THESE FEATURES BETTER THAN THE LARGER-SCALE MODELS WITH PARAMETERIZED CONVECTION (NOT A SURPRISE)... AND HAVE LARGELY FOLLOWED THIS SOLUTION FOR THE NEXT 12 HRS OR SO. EXPECT SCATTERED SHOWERS AND A FEW STORMS THROUGH MID MORNING... WITH THE BEST CHANCE SHIFTING TO NRN/ERN CWA NEAR AND SOON AFTER SUNRISE. WE SHOULD THEN SEE A PERIOD OF RELATIVE SUBSIDENCE FROM ROUGHLY LATE MORNING THROUGH MID AFTERNOON... AS THE VA MCV SHIFTS OFF THE COAST INDUCING SURFACE LOW FORMATION ALONG THE WEAK FRONTAL ZONE. AS THIS OCCURS... THE NORTHEAST FLOW ON THE BACKSIDE OF THIS LOW SHOULD HELP DRAW THE FRONTAL ZONE SOUTHWARD INTO NORTH CENTRAL/NE NC. THE LAST SEVERAL GFS RUNS HAVE TAKEN THIS FRONT MUCH FURTHER INTO NC THAN THE OTHER MODEL SOLUTIONS. WHILE THERE IS A CHILLY SURFACE HIGH CENTERED OVER QUEBEC NOSING SOUTHWARD OVER THE NORTHEAST STATES INTO THE NRN MIDATLANTIC REGION... THIS LOOKS TO BE CENTERED TOO FAR NORTH TO HAVE MUCH INFLUENCE ON THE FRONT THIS FAR SOUTH. EXPECT A WIND SHIFT TO NORTHEASTERLY OVER THE NE CWA WITH SLIGHTLY COOLER TEMPS MOVING IN LATE TODAY INTO TONIGHT... BUT THE COOLING SHOULDN`T BE THAT EXTREME. WILL FORECAST HIGHS TODAY IN THE LOW-MID 80S EXCEPT FOR MID- UPPER 70S IN THE FAR NE. ATTENTION THEN TURNS TO THE CONVECTION NOW ALONG THE FRONT OVER KS/MO/IA/IL AND THE POTENTIAL FOR ITS RESULTING MCV TO MOVE ESE ALONG THE FRONTAL ZONE INTO OUR REGION LATE TODAY INTO TONIGHT. THE GFS HINTS AT THIS... SHOWING SPOTTY MID LEVEL VORTICITY MAXIMA (LOOKING LIKE CONVECTIVE FEEDBACK) MOVING TO THE CENTRAL/SRN APPALACHIANS LATE TODAY INTO TONIGHT. IT MAKES SENSE THAT THIS WOULD TRIGGER CONVECTION ALONG AND EAST OF THE MOUNTAINS WHERE MODELS INDICATE MUCAPE OF 1500-2500 J/KG IN THE 21Z-06Z TIME FRAME WITH DEEP LAYER BULK SHEAR AROUND 30 KTS... STILL RATHER MODEST BUT ENOUGH TO SUSTAIN CONVECTION AS THE COLD POOL TRACKS ESE THROUGH NRN/ERN NC. WILL SHOW A PERIOD OF LOW POPS THROUGH MID AFTERNOON... FOLLOWED BY A RISE TO SCATTERED SHOWERS/STORMS LATE AFTERNOON THROUGH THIS EVENING... TRENDING DOWN OVERNIGHT AS THIS PERTURBATION EXITS TO OUR EAST. WITH THE FRONT STILL EXPECTED TO BE SITTING OVER THE NE CWA OVERNIGHT... WILL HAVE LOWS IN THE 60-65 RANGE EXCEPT FOR MID-UPPER 50S NE. -GIH && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... AS OF 220 PM TUESDAY... THE WEST-CENTRAL UNITED STATES TROUGH AND UPPER RIDGING OVER THE SOUTH ATLANTIC STATES WILL GENERATE WARMTH THURSDAY INTO FRIDAY WITH A CHANCE OF SHOWERS AND THUNDERSTORMS LATE FRIDAY INTO FRIDAY NIGHT. THE MID/UPPER TROUGH IS FORECAST TO MOVE EAST AND BRING AN ACTIVE COLD FRONT ACROSS THE APPALACHIANS LATE FRIDAY. HOWEVER... THE SYSTEM IS FORECAST TO BE IN A WEAKENING MODE AS IT PUSHES EAST OF THE MOUNTAINS RESULTING IN LESS IN THE WAY OF A SEVERE WEATHER THREAT OVER OUR REGION AS OPPOSED TO WEST OF THE MOUNTAINS. THE FRONT WILL PUSH OFFSHORE BY SATURDAY LATE AND THIS WILL DECREASE THE CHANCE OF SHOWERS WITH A BRIEF PERIOD OF TRANQUIL WEATHER EXPECTED SUNDAY INTO MONDAY. A RETURN TO STORMY WEATHER IS EXPECTED ESPECIALLY BY MONDAY NIGHT AND TUESDAY AS YET ANOTHER SYSTEM IS FORECAST TO DEVELOP OVER THE MID MISSISSIPPI VALLEY PULLING GULF MOISTURE AND A WARM FRONT INTO THE TENNESSEE VALLEY AND MID ATLANTIC REGION. THURSDAY AND FRIDAY SHOULD BE THE WARMEST DAYS WITH HIGHS 80-85 AND LOWS IN THE 60S. THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL INCREASE FRIDAY INTO FRIDAY NIGHT WITH THE COLD FRONT APPROACHING. THERE IS A CHANCE OF SHOWERS... MAINLY IN THE SOUTH AND EAST SATURDAY MORNING... OTHERWISE DRIER AND COOLER WEATHER IS EXPECTED LATER SATURDAY THROUGH SUNDAY. LOWS IN THE 50S. HIGHS IN THE LOWER O MID 70S. THERE IS A CHANCE OF SHOWERS AGAIN LATE MONDAY INTO TUESDAY WITH WARMER TEMPERATURES. -BV && LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 230 AM WEDNESDAY... THERE IS GROWING CONFIDENCE WITH REGARD TO A FRONTAL SYSTEM THAT IS PROGGED TO MOVE ACROSS THE CAROLINAS ON FRIDAY EVENING THROUGH SATURDAY MORNING. THIS WILL BE FOLLOWED BY WEAK RIDGING ALOFT AND SURFACE HIGH PRESSURE OVER THE MID ATLANTIC THROUGH THE WEEKEND. CONFIDENCE IN THE FORECAST TAKES A BIG TURN FOR THE WORSE BEGINNING ON MONDAY AS MODEL SOLUTIONS DIVERGE CONSIDERABLY. ABOUT THE ONLY THING THEY AGREE ON AT THIS POINT IS SOME KIND OF UPPER RIDGING OVER THE SOUTHEAST BUT EVEN THE POSITION AND TIMING OF THAT IS IN QUESTION AT THIS TIME. THE PROBLEMS EARLY NEXT WEEK STEM FROM A CUTOFF UPPER LEVEL LOW OVER TEXAS THAT FUNNELS MOISTURE OUT OF THE GULF AND OVER THE DEEP SOUTH BUT THERE ARE MASSIVE QUESTIONS IN TIMING AS THE ECMWF SOLUTION HAS PRECIPITATION REACHING CENTRAL NC BY MONDAY AFTERNOON AND THE GFS DOESN`T HAVE ANYTHING MEASURABLE OVER THE CWA UNTIL THURSDAY NIGHT. THAT QUALIFIES AS AN EXTREMELY LOW CONFIDENCE FORECAST AND WILL BE HANDLED AS SUCH. THEREFORE WILL MAINTAIN CHANCE POPS FROM MONDAY THROUGH THE END OF THE PERIOD. SHIFTING THE CONVERSATION FROM WHAT WE DON`T KNOW TO MORE OF WHAT WE DO KNOW REGARDING THE FRONTAL SYSTEM ON FRIDAY...SPC STILL HAS AN AREA OF 15% RISK OF SEVERE STORMS OVER ALL OF CENTRAL NC. AFTER A CLOSER LOOK AT THE FORECAST SOUNDINGS ON FRIDAY AFTERNOON...STORMS WILL BE INSTABILITY DRIVEN WITH THE SOUTHEASTERN PART OF THE CWA MOST LIKELY TO SEE STRONGER STORM ACTIVITY BUT THE POSSIBILITY WILL REMAIN EVERYWHERE. THE KFAY MODEL SOUNDINGS SHOW JUST OVER 1100 J/KG OF SURFACE BASED CAPE WITH 500 J/KG OCCURRING WITHIN THE HAIL GROWTH ZONE. THE HAIL THREAT LOOKS BETTER THAN THE WIND THREAT AT THIS TIME AS SHEAR IS MEAGER...ESPECIALLY IN THE LOW LEVELS. SOME INVERTED V SIGNATURES IN THE SOUNDING AND SOME RELATIVE DRYING AT THE 700 MB LEVEL COULD INCREASE THE POTENTIAL FOR SOME WET MICROBURSTS BUT OVERALL THE ENVIRONMENT FOR WIND OUTSIDE OF A LARGER HAIL CORE COLLAPSING IS LESS FAVORABLE AND VERY LOW AMOUNTS OF HELICITY SUGGEST TORNADOES WILL NOT BE LIKELY EITHER. OVERALL FEELING IS THAT SOME STRONGER STORMS WILL POP UP FRIDAY AFTERNOON BUT ANY SEVERE WILL BE FAIRLY ISOLATED. WORTH WATCHING TO SEE HOW IT EVOLVES OVER THE NEXT COUPLE OF DAYS. CONVECTION SHOULD PRODUCE DECENT QPF VALUES IN THE RANGE OF A QUARTER TO THREE QUARTERS OF AN INCH. PW VALUES ARE OVER AN INCH AND A HALF. FRIDAY WILL BE THE WARMEST DAY AHEAD OF THE FRONT WITH HIGHS IN THE MID 80S AND THEN TEMPS WILL COOL OFF AFTER THE FRONT PASSES WITH HIGH PRESSURE BRINGING IN COOL AIR FROM THE NORTH. EXPECT MOSTLY LOW TO MID 70S FOR HIGHS FOR THE REMAINDER OF THE PERIOD AFTER FRIDAY. LOWS IN THE LOWER 50S TO MID 60S. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 110 AM WEDNESDAY... PRIMARY AVIATION CONCERN NEXT 24 HRS: CHANCE OF MVFR OR IFR CIGS NOW THROUGH MID MORNING WITH A FEW SHOWERS AND POSSIBLE ISOLATED STORMS. CONFIDENCE IS LOWER THAN USUAL REGARDING THE FORECAST THROUGH THIS MORNING. A VERY MOIST AIR MASS REMAINS IN PLACE FROM THE SURFACE UP THROUGH THE MID LEVELS (ABOVE 15 000 FT). FLIGHT CATEGORIES ARE LIKELY TO WAVER AMONG MVFR... IFR... AND VFR THIS MORNING... HOWEVER EXPECT VFR CONDITIONS TO OCCUR MOST OF THE TIME THROUGH MID MORNING. AVIATORS SHOULD REMAIN ALERT FOR POCKETS OF SUB-VFR CIGS... AS THEY ARE LIKELY TO HAPPEN BUT DIFFICULT TO PINPOINT. SCATTERED SHOWERS WILL AFFECT CENTRAL NC THROUGH THE FIRST 6-9 HRS OF THE TAF VALID PERIOD... BUT VSBYS SHOULD REMAIN MAINLY VFR WITH THESE... ONLY BRIEFLY DROPPING TO MVFR FOR LESS THAN A HALF HOUR AT A TIME. MODELS HAVE HAD DIFFICULTY WITH RECENT AND CURRENT CONDITIONS HERE AND UPSTREAM... BUT ALL AGREE ON A HIGH PROBABILITY OF VFR CONDITIONS FROM LATE MORNING THROUGH THE DAY... WITH VERY FEW IF ANY SHOWERS/STORMS AS WE SHOULD BE IN A RELATIVE LULL PERIOD BETWEEN CONVECTIVE SYSTEMS. A COUPLE OF MODELS HINT AT MORE STORMS ROLLING OVER THE CENTRAL/SRN APPALACHIANS THIS EVENING AND POTENTIALLY AFFECTING INT/GSO/RDU TOWARD THE END OF THE TAF VALID PERIOD WITH BRIEF SUB-VFR CIGS/VSBYS AND GUSTY WINDS... HOWEVER CONFIDENCE IS NOT HIGH ENOUGH IN THE LOCATION AND TIMING OF ANY SUCH SYSTEM TO INCLUDE IN THE TAFS AT THIS TIME. WILL CONTINUE TO MONITOR. LOOKING BEYOND 06Z EARLY THU MORNING... MAY NEED TO INCLUDE A CHANCE FOR SUB-VFR SHOWERS/STORMS INTO THE OVERNIGHT HOURS. OTHERWISE... WE SHOULD SEE AREAS OF LOW CLOUDS AND FOG DEVELOP ESPECIALLY AFFECTING RDU/RWI AS A BACKDOOR FRONT DROPS SOUTHWARD INTO THE NORTHEAST PORTION OF CENTRAL NC... WITH LIGHT SURFACE WINDS SHIFTING AROUND TO NORTHEASTERLY. ANY LOW CLOUDS SHOULD LIFT TO VFR THU MORNING... REMAINING VFR THROUGH THU EVENING WITH A FEW SHOWERS/STORMS POSSIBLE THU AFTERNOON. AN APPROACHING COLD FRONT ON FRIDAY WILL BRING A GOOD CHANCE OF SUB-VFR CONDITIONS WITHIN SHOWERS AND STORMS FRI AFTERNOON AND EVENING. VFR CIGS/VSBYS ARE EXPECTED BEHIND THE FRONT LATE FRI NIGHT THROUGH SUN AS HIGH PRESSURE BUILDS IN. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...VINCENT LONG TERM...ELLIS AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1250 AM EDT WED APR 8 2015 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE OFFSHORE THROUGH MIDWEEK. A COLD FRONT WILL PUSH SOUTH INTO THE REGION LATE WEDNESDAY AND STALL OVER THE AREA THROUGH EARLY THURSDAY. THE FRONT WILL LIFT NORTH OF THE REGION THURSDAY NIGHT AND FRIDAY. A COLD FRONT WILL APPROACH FROM THE WEST FRIDAY NIGHT. THE FRONT WILL CROSS EASTERN NC SATURDAY THEN STALL SOUTH OF THE AREA SUNDAY INTO MONDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1245 AM WEDNESDAY...NORTHERN FRINGE OF PRECIPITATION AREA OVER SOUTH CAROLINA EXTENDS NORTH INTO OUR COASTAL PLAIN COUNTIES LATE TONIGHT. BASED ON TRENDS IN THE RADAR WITH ACTIVITY HOLDING TOGETHER AND LATEST HRRR MODEL RUN WHICH TAKES THE PRECIPITATION SLOWLY EAST ACROSS THE REGION THROUGH THE MORNING HOURS HAVE DECIDED TO INCREASE POPS TO LIKELY ALONG AND SOUTH OF THE HIGHWAY 70 CORRIDOR WITH CHANCE POPS ELSEWHERE. LOW AMPLITUDE SHORTWAVES WILL CONTINUE TO TRAVERSE THE AREA DURING THE NEXT 24-36 HOURS ENHANCING PRECIPITATION AS THEY CROSS THE REGION. MILD TEMPS EXPECTED WITH LOWS IN THE UPPER 50S/LOWER 60S. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 AM THURSDAY/... AS OF 255 PM TUESDAY...CONTINUED PREVIOUS FCST INDICATING A WEAK BACK DOOR FRONT PUSHING S INTO NERN SXNS LATE WED. EXPECT THERE WILL BE ENOUGH MOISTURE LIFT AND INSTABILITY FOR SCT SHRA/TSRA AWAY FROM THE COAST DURING MAX HEATING. TEMPS WARM FROM THE LOWER 80S INLAND TO LOWER 70S COAST. && .LONG TERM /THURSDAY THROUGH WEDNESDAY/... AS OF 355 PM TUESDAY...SOME DIFFERENCES EXIST BETWEEN THE 12Z GUIDANCE WITH REGARDS TO THE BACKDOOR COLD FRONT MOVING SOUTH INTO EASTERN NC WEDNESDAY EVENING INTO WEDNESDAY NIGHT. WEAK ZONAL FLOW ALOFT WED NIGHT. GUIDANCE NOW SUGGESTS THE FRONT WILL STRUGGLE TO REACH SOUTHERN ZONES AND HAVE INDICATED THIS TREND IN WINDS FORECAST. MAINTAINED LOW CHANCE TO SLIGHT CHANCE POPS WEDNESDAY NIGHT INTO THURSDAY AND KEPT MENTION OF THUNDERSTORMS FOR SOUTHERN ZONES/COAST THURSDAY DUE TO WEAK INSTABILITY NOTED IN FORECAST SOUNDINGS/SREF PLUMES. WEAK SHORT WAVE RIDGING WILL EVOLVE ACROSS AREA THURSDAY AS THE WEAK SURFACE FRONT LIFTS NORTH OF THE CWA. MORE CONFIDENT WITH WARMER TEMPS THURSDAY AS THE FRONT REMAINS VERY WEAK EARLY, THEN LIFTS NORTH OF THE AREA DURING THE DAY ALLOWING FOR AMPLE INSOLATION. THIS SHOULD AID IN DESTABILIZING THE ATMOSPHERE THOUGH SHEAR REMAINS THE LIMITING FACTOR. THURSDAY NIGHT THROUGH FRIDAY NIGHT, SW FLOW EXPECTED TO PERSIST AHEAD OF A STRONGER COLD FRONT APPROACHING LATE FRIDAY NIGHT. THURSDAY NIGHT SHOULD STAY MOSTLY DRY. NO CHANGE TO PREVIOUS THINKING FOR SHOWERS AND THUNDERSTORMS FRIDAY FOR INLAND SECTIONS AS DECENT INSTABILITY AND UNIDIRECTIONAL WEST-SOUTHWEST FLOW IS ENOUGH TO SUPPORT CHC POPS IN AFTERNOON INLAND OF SEA BREEZE. LOW LEVEL THICKNESSES SUPPORT MID 80S FOR INLAND SECTIONS. INCREASING CHANCES FOR SHOWERS/TSTMS AHEAD OF FRONT FRI NIGHT INTO SAT WITH FRONT EXPECTED TO PUSH THROUGH AREA SAT MIDDAY. DROPPED POPS SAT NIGHT WITH MODELS INDICATING FRONT S AND E OF AREA. MILD OVERNIGHT TEMPS FRI AND WARM SATURDAY MORNING AHEAD OF THE FRONT, HIGHS IN THE MID 70S INLAND TO 60S ALONG THE COAST. SUNDAY INTO TUESDAY, MODELS INDICATE DRY CONDITIONS SUN AND SUN NIGHT WITH HIGH PRESSURE EXTENDING OVER THE AREA FROM THE DELMARVA REGION. HIGH MOVES OFFSHORE MON LEADING TO SOUTHEASTERLY FLOW ACROSS EASTERN NC. SOME DIFFERENCES BEGIN TO APPEAR IN THE EXTENDED GUIDANCE WITH THE GFS MUCH SLOWER WITH A FRONT APPROACHING FROM THE WEST MONDAY NIGHT, WHILE THE ECMWF MOVES A WEAK BOUNDARY INTO THE AREA BY EARLY TUESDAY MORNING. TEMPS FOR THE WEEKEND INTO TUESDAY WILL BE NEAR CLIMATOLOGY WITH HIGHS IN THE 70S AND LOWS IN THE 50S. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM /THROUGH WEDNESDAY NIGHT/... AS OF 1245 AM WEDNESDAY...DIFFICULT FORECAST WITH CONVECTIVE DEBRIS CLOUDS AND MIXING LIMITING RADIATIONAL COOLING AT TIMES...AND PRECIPITATION APPROACHING THE TAF SITES FROM THE WEST. THE PRECIPITATION WILL AFFECT ALL OF THE TAF SITES LATE TONIGHT INTO WEDNESDAY MORNING ESPECIALLY KOAJ AND KEWN BUT SHOULD BE MOSTLY LIGHT WITH BRIEF MVFR CONDITIONS. OUTSIDE OF THE PRECIPITATION FORECAST SOUNDINGS INDICATED A SATURATED BOUNDARY LAYER WHICH WILL LEAD TO FOG AND OR LOW STRATUS CLOUDS. NEW BERN HAS DECOUPLED AS HAS RICHLANDS SO THESE AREAS HAVE THE BEST POTENTIAL FOR IFR FOG OVERNIGHT AS THE GUIDANCE INDICATES THAT KPGV AND KISO MAY REMAIN MIXED. HOWEVER THE HRRR AND NARRE GUIDANCE IS INDICATING IFR CEILINGS ALL TAF SITES BY 09Z SO EXPECTING POOR CONDITIONS OVERNIGHT EARLY WEDNESDAY FOR AT LEAST SEVERAL HOURS AT ALL OF THE TAF SITES. CONDITIONS SHOULD IMPROVE TO VFR LATE WEDNESDAY MORNING AND AFTERNOON OUTSIDE OF ANY SCATTERED SHOWER/THUNDERSTORM ACTIVITY THAT DEVELOPS. GUIDANCE IS AGAIN POINTING TO THE POTENTIAL FOR IFR CONDITIONS REDEVELOPING AGAIN WEDNESDAY EVENING AS THE BL REMAINS SATURATED. LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 430 PM TUESDAY...SOME LOWER CIGS COULD PERSIST THURS MORNING WITH LOW LEVEL NE FLOW. VFR MAINLY EXPECTED THURS NIGHT INTO FRIDAY...THEN HIGHER THREAT OF SUB-VFR CONDITIONS FRI NIGHT INTO SAT WITH GOOD COVERAGE OF SHOWERS AND TSTMS EXPECTED AS STRONGER FRONT MOVES INTO AREA. GUSTY SW WINDS 15-25 MPH LIKELY FRIDAY AHEAD OF FRONT. HIGH PRESSURE WILL ALLOW AVIATION CONDITIONS TO IMPROVE TO VFR SATURDAY EVENING THROUGH SUNDAY. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 1245 AM WEDNESDAY...NO CHANGES TO PREVIOUS THINKING. OFFSHORE HIGH PRESSURE WILL CONTINUE TO EXTEND WEST INTO THE NC WATERS THROUGH TONIGHT. S-SW FLOW 5 TO 15 KT WITH SEAS MAINLY 2-4 FT. SW WINDS 10-15 KT MOST OF THE DAY ON WED EXCEPT FOR THE NRN WATERS WHERE A BACKDOOR FRONT MOVES INTO THE NRN COASTAL WATERS LATE. WINDS SHIFT TO N ACROSS THE NRN WATERS AROUND 10 KT IN THE AFTERNOON. SEAS WILL BE 2-4 FT ON WED. LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 430 PM TUESDAY...WEAK BACKDOOR FRONT WILL SAG SOUTH INTO THE EASTERN NC WATERS WED EVENING INTO WED NIGHT, WITH FRONT EXPECTED TO RETURN NORTH THURS. WINDS GENERALLY 15 KT OR LESS WITH THIS FRONT. STRONGEST WINDS EXPECTED FRI AND FRI NIGHT AHEAD OF STRONGER COLD FRONT, SW 15-25 KT WITH SEAS BUILDING TO SMALL CRAFT ADVISORY LEVELS FRI NIGHT THROUGH MIDDAY SATURDAY. NE SURGE 10-20 KT EXPECTED LATE SAT THROUGH SUNDAY. ADJUSTED SEAS WITH LATEST NWPS. HEIGHTS MAINLY 3-4 FT WED-THURS, BUILDING TO 4-6 FT FRI-SAT THEN DIMINISHING 2-4 FT SUNDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JAC NEAR TERM...JAC/JME/BTC SHORT TERM...JAC LONG TERM...DAG AVIATION...JME/DAG MARINE...JAC/JME/BTC/DAG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
949 PM CDT THU APR 9 2015 .UPDATE... ISSUED AT 949 PM CDT THU APR 9 2015 PRETTY STRONG SHORTWAVE CONTINUES TO DIG TOWARDS THE NORTHEASTERN CWA AND A BIT OF RAIN HAS BEEN REPORTED IN THAT AREA. MODELS DO NOT REALLY KICK IN THE HIGHER QPF VALUES UNTIL THE 06 TO 09Z TIME FRAME...AND THIS SEEMS REASONABLE GIVEN CANADIAN RADAR. WILL CONTINUE TO KEEP POPS MAINLY IN THE NORTHEASTERN CWA LATER TONIGHT. THE NAM AND RAP DROP 3-4 INCHES OF SNOW IN SPOTS...BUT MODEL SOUNDINGS SHOW THAT THE LOWEST PART OF THE COLUMN WILL BE STILL ABOVE ZERO SO THINK THAT THE ACCUMULATIONS ARE OVERDONE. WILL CONTINUE TO KEEP A RAIN SNOW MIX BUT HAVE FAIRLY LIGHT ACCUMULATIONS FOR NOW AND WILL KEEP AN EYE ON HOW TEMPERATURES RESPOND AS THE SYSTEM DIGS DOWN. UPDATE ISSUED AT 644 PM CDT THU APR 9 2015 TWEAKED UP WINDS A BIT THIS EVENING AS IT HAS BECOME RATHER GUSTY AS A FRONTAL BOUNDARY MOVES THROUGH. NOT MUCH FROM THE RADAR RETURNS IN NORTHWESTERN MN HAS BEEN REACHING THE GROUND YET...SO WILL KEEP POPS FAIRLY LOW UNTIL THE MAIN UPPER LOW COMES DOWN LATER TONIGHT. THE RAP HAS BEEN SHOWING THE POSSIBILITY OF SOME FZRA IN THE FAR NORTHEASTERN COUNTIES...BUT MODEL SOUNDINGS FROM OTHER MODELS HAVE THE COLUMN COOLING JUST AS FAST AS SFC TEMPS AND KEEP MORE OF A RAIN/SNOW MIX. FOR NOW WILL KEEP ANY FREEZING PRECIP OUT BUT WILL TAKE ANOTHER LOOK AT THINGS AS FURTHER MODEL RUNS TRICKLE IN. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 338 PM CDT THU APR 9 2015 UPPER LOW FORECASTED BY ALL MODELS TO PROPAGATE SOUTHWARD JUST EAST OF THE VALLEY TONIGHT. AHEAD OF THIS FEATURE LIKELY ENOUGH FORCING AND MOISTURE FOR ISOLD SHOWERS. THE BETTER PRECIP CHANCES WILL BE ASSOCIATED WITH THE DEFORMATION ZONE FORCING...WHERE THE P-TYPE SHOULD BE MOSTLY SNOW...WITH AMOUNTS UP TO AN INCH. HIGH PRESSURE INFLUENCES THE REGION FRIDAY INTO FRIDAY NIGHT...LEADING TO NO/MINIMAL IMPACTS. NOT MUCH CHANCE TO EXPECTED TEMPERATURES. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 338 PM CDT THU APR 9 2015 SATURDAY-SUNDAY...STRONGER WAVE IN MORE ZONAL UPPER FLOW APPROACHES THE REGION ON SATURDAY...MOVING THROUGH ON SUNDAY. MODELS INDICATE THAT STRONG LOW LEVEL SOUTHERLY FLOW MAY BE SUFFICIENT TO BRING ENOUGH MOISTURE NORTHWARD FOR AN UNSTABLE ATMOSPHERE SAT NIGHT...AT LEAST EAST OF THE VALLEY. INSTABILITY COMBINED WITH POCKETS OF STRONGER 850MB WARM AIR ADVECTION WILL BRING THUNDER CHANCES. INSTABILITY IS WEAK...AND MODELS INDICATE COVERAGE ISOLD-SCT...BUT THERE ARE ENOUGH SIGNALS TO CONTINUE THE THUNDER MENTION. SHOWERS QUICKLY MOVE EAST ON SUNDAY. WINDY CONDITIONS...POSSIBLY ADVISORY CRITERIA...LIKELY ON SUNDAY (DEEP MIX LAYER WITH UNIDIRECTIONAL FLOW AND AVERAGE SPEEDS AROUND 35 KNOTS). THIS COULD ALSO BE A POTENTIAL CRITICAL FIRE WEATHER DAY. MONDAY-THURSDAY...A MORE ACTIVE PATTERN WILL DEVELOP IN THE LONG TERM. ALTHOUGH LONG TERM MODELS HAVE TYPICAL DIFFERENCES IN TIMING AND PLACEMENT OF A SYSTEM 5 TO 6 DAYS OUT...THEY ARE IN GENERAL AGREEMENT WITH A DECENT WARMUP INTO THE 70S FOLLOWED BY A MID PLAINS CYCLONE DEVELOPING AND WELCOMING SOME WELL NEEDED MOISTURE TO THE REGION. THERE IS THE POTENTIAL FOR A COUPLE OF DAYS OF PERIODIC RAIN SHOWERS AND PERHAPS SOME THUNDER AS A FRONTAL SYSTEM MOVES THROUGH. THE MIDDLE OF THE WEEK IS SHOWING THE BEST AGREEMENT FOR PRECIPITATION AND PLANS TO CHANGE THE CHANCE POPS IN FOR DAYS 5 AND 6. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 644 PM CDT THU APR 9 2015 CIGS HAVE ALL BE VFR AS THERE HAS BEEN A FAIR AMOUNT OF MID LEVEL CU AS A COLD FRONT MOVES THROUGH THE AREA. THE WINDS HAVE BECOME QUITE STRONG AS THE FRONT MOVES THROUGH SO BUMPED UP SPEEDS TO 15 TO 20 SUSTAINED WITH GUSTS NEAR 25 KTS AT TIMES. SOME MVFR CIGS WILL MOVE INTO KTVF AND KBJI LATER TONIGHT AS THE MAIN UPPER LOW DIGS DOWN INTO THE AREA...ALONG WITH SOME SCATTERED RAIN OR SNOW SHOWERS. WILL KEEP THE SITES FURTHER WEST VFR AND DRY. ALL SITES SHOULD BE VFR BY MID MORNING TOMORROW AND WINDS SHOUL BEGIN TO SETTLE DOWN. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...JR SHORT TERM...TG LONG TERM...TG/SPEICHER AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
934 PM CDT THU APR 9 2015 .UPDATE... ISSUED AT 930 PM CDT THU APR 9 2015 FOR LATE EVENING UPDATE HAVE DROPPED CLOUD COVER DOWN QUITE A BIT WITH ONLY SOME HIGH CLOUDS MOVING THROUGH. ONLY CONCERN WITH CLOUD COVER IS FOR LATER TONIGHT AS SOME LOW CLOUDS TO THE WEST OF LAKE MANITOBA ARE TRYING TO SLOWLY SETTLE SOUTHWARD. THIS MAY GRAZE PARTS OF FAR NORTH CENTRAL LATE TONIGHT. ONLY OTHER CHANGE TO THE FORECAST WAS TO ADD SOME PATCHY FOG OVER THE SOUTHWESTERN PART OF THE STATE THAT RECEIVED ACCUMULATING SNOW LAST NIGHT. WITH TODAYS MELTING...PLENTY OF LOW LEVEL MOISTURE IS IN PLACE AS WINDS ARE GOING CALM AND TEMPERATURE CONTINUES TO DROP. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 623 PM CDT THU APR 9 2015 GUSTY WEST TO NORTHWEST WINDS STILL ON TRACK TO DIMINISH BY AROUND SUNSET. OTHERWISE...A QUIET EVENING IS EXPECTED AS SKIES CLEAR UP AND ISOLATED LIGHT SHOWERS COME TO AN END LATER THIS EVENING. UPDATES HAVE BEEN SENT. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 323 PM CDT THU APR 9 2015 FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE ISOLATED SHOWERS AND GUSTY WINDS THROUGH EARLY THIS EVENING. OTHERWISE A QUIET TONIGHT AND FRIDAY. CURRENTLY...NORTHERLY FLOW ALOFT WITH A WEAK RIDGE ACROSS THE NORTHERN ROCKIES AND A STRONG S/WV MOVING SOUTH TOWARDS NORTHERN MINNESOTA. LARGE CU FIELD DEVELOPING AS EXPECTED THIS AFTERNOON AHEAD OF AN INVERTED SFC TROUGH/FRONTAL BOUNDARY NOW PUSHING SOUTH ACROSS NORTHERN NORTH DAKOTA. A FEW SHOWERS POPPING UP WITHIN THE CU AS THE HRRR AND 4KM WRF ADVERTISED. DOUBTFUL MUCH WILL REACH THE GROUND BUT WILL MAINTAIN SHOWERS IN THE FORECAST NOW THROUGH 03Z. WINDS GUSTING TO AROUND 30KTS AS WE MIX TO AROUND 700MB AND SHOULD CONTINUE UNTIL AROUND SUNDOWN...THEN DISSIPATE QUICKLY. WINDS WILL BE ENHANCED BY THE SHOWER ACTIVITY...AIDED WITH EVAPORATIONAL COOLING BENEATH THE CLOUD BASES AS PRECIPITATION FALLS. SURFACE HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS TONIGHT CLEARING THE SKY. HIGH PRESSURE CONTINUES SOUTH AND EAST FRIDAY ALLOWING FOR RETURN FLOW/WAA INTO THE REGION. DECENT DAY FRIDAY WITH HIGHS IN THE 50S AND A RELATIVELY LIGHT WIND AND MOSTLY SUNNY SKY. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 323 PM CDT THU APR 9 2015 THE MAIN FORECAST ISSUES IN THE LONG TERM INCLUDE STRONG AND GUSTY NORTHWEST WINDS SUNDAY - WITH POTENTIAL FIRE WEATHER ISSUES - AND AN UPPER LEVEL LOW/TROUGH SETTING UP FOR NEXT WEDNESDAY/THURSDAY. FRIDAY NIGHT AND SATURDAY: HIGH PRESSURE EXITS THE AREA TO THE EAST AS LOW PRESSURE DEVELOPS IN THE LEE OF THE ROCKIES AND APPROACHES NORTH DAKOTA. BY SATURDAY AFTERNOON AN UPPER LEVEL TROUGH EXPANDS EASTWARD AND SOUTHWEST FLOW ALOFT IS ESTABLISHED OVER THE NORTHERN PLAINS. MEANWHILE A SURFACE WARM FRONT IS EXPECTED TO ENTER WESTERN NORTH DAKOTA...WITH HIGHS REACHING THE UPPER 60S AND LOWER 70S. SATURDAY NIGHT: UPPER LEVEL ENERGY REACHES NORTH DAKOTA AHEAD OF AND ALONG AN ASSOCIATED COLD FRONT. CHANCE OF SHOWERS...MAINLY NORTH AND WEST. SUNDAY: THE COLD FRONT PUSHES SOUTHEAST ACROSS THE STATE EARLY SUNDAY MORNING...WITH STRONG NORTHWEST WINDS OF 20 TO 35 MPH WITH GUSTS TO 40 MPH POSSIBLE. SEE THE FIRE WEATHER DISCUSSION BELOW FOR FIRE WEATHER CONCERNS. MONDAY AND TUESDAY SHOULD BE DRY WITH HIGHS IN THE 60S MONDAY...AND 65 TO 75 TUESDAY. THE NEXT UPPER LEVEL TROUGH MOVES ACROSS THE ROCKIES AND EMERGES IN THE WESTERN PLAINS TUESDAY NIGHT...CROSSING THE PLAINS WEDNESDAY AND THURSDAY. CHANCES OF RAIN SHOWERS INCREASE DURING THIS TIME...WITH HIGHS 50 TO 60 WEDNESDAY...AND UPPER 40S TO LOWER 50S THURSDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 623 PM CDT THU APR 9 2015 GUSTY WEST TO NORTHWEST WINDS WILL DIMINISH AROUND SUNSET THIS EVENING. VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. && .FIRE WEATHER... ISSUED AT 323 PM CDT THU APR 9 2015 SUNDAY: STRONG NORTHWEST WINDS OF 20 TO 35 MPH WITH GUSTS TO 40 MPH POSSIBLE. HIGHS OF 55 TO 60 EXPECTED...WITH MINIMUM RELATIVE HUMIDITY VALUES AROUND 20 PERCENT SOUTHWEST TO AROUND 25 PERCENT NORTHWEST AND CENTRAL. WILL CONTINUE TO MONITOR FOR POSSIBLE FIRE WEATHER WATCH. RECENT RAIN AND SNOWFALL OVER THE REGION IS NOTED...AND WEATHER DORMANT GRASSES WILL HAVE TIME TO DRY OUT IS THE MAIN QUESTION. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJS SHORT TERM...JV LONG TERM...NH AVIATION...JJS FIRE WEATHER...JV
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
644 PM CDT THU APR 9 2015 .UPDATE... ISSUED AT 644 PM CDT THU APR 9 2015 TWEAKED UP WINDS A BIT THIS EVENING AS IT HAS BECOME RATHER GUSTY AS A FRONTAL BOUNDARY MOVES THROUGH. NOT MUCH FROM THE RADAR RETURNS IN NORTHWESTERN MN HAS BEEN REACHING THE GROUND YET...SO WILL KEEP POPS FAIRLY LOW UNTIL THE MAIN UPPER LOW COMES DOWN LATER TONIGHT. THE RAP HAS BEEN SHOWING THE POSSIBILITY OF SOME FZRA IN THE FAR NORTHEASTERN COUNTIES...BUT MODEL SOUNDINGS FROM OTHER MODELS HAVE THE COLUMN COOLING JUST AS FAST AS SFC TEMPS AND KEEP MORE OF A RAIN/SNOW MIX. FOR NOW WILL KEEP ANY FREEZING PRECIP OUT BUT WILL TAKE ANOTHER LOOK AT THINGS AS FURTHER MODEL RUNS TRICKLE IN. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 338 PM CDT THU APR 9 2015 UPPER LOW FORECASTED BY ALL MODELS TO PROPAGATE SOUTHWARD JUST EAST OF THE VALLEY TONIGHT. AHEAD OF THIS FEATURE LIKELY ENOUGH FORCING AND MOISTURE FOR ISOLD SHOWERS. THE BETTER PRECIP CHANCES WILL BE ASSOCIATED WITH THE DEFORMATION ZONE FORCING...WHERE THE P-TYPE SHOULD BE MOSTLY SNOW...WITH AMOUNTS UP TO AN INCH. HIGH PRESSURE INFLUENCES THE REGION FRIDAY INTO FRIDAY NIGHT...LEADING TO NO/MINIMAL IMPACTS. NOT MUCH CHANCE TO EXPECTED TEMPERATURES. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 338 PM CDT THU APR 9 2015 SATURDAY-SUNDAY...STRONGER WAVE IN MORE ZONAL UPPER FLOW APPROACHES THE REGION ON SATURDAY...MOVING THROUGH ON SUNDAY. MODELS INDICATE THAT STRONG LOW LEVEL SOUTHERLY FLOW MAY BE SUFFICIENT TO BRING ENOUGH MOISTURE NORTHWARD FOR AN UNSTABLE ATMOSPHERE SAT NIGHT...AT LEAST EAST OF THE VALLEY. INSTABILITY COMBINED WITH POCKETS OF STRONGER 850MB WARM AIR ADVECTION WILL BRING THUNDER CHANCES. INSTABILITY IS WEAK...AND MODELS INDICATE COVERAGE ISOLD-SCT...BUT THERE ARE ENOUGH SIGNALS TO CONTINUE THE THUNDER MENTION. SHOWERS QUICKLY MOVE EAST ON SUNDAY. WINDY CONDITIONS...POSSIBLY ADVISORY CRITERIA...LIKELY ON SUNDAY (DEEP MIX LAYER WITH UNIDIRECTIONAL FLOW AND AVERAGE SPEEDS AROUND 35 KNOTS). THIS COULD ALSO BE A POTENTIAL CRITICAL FIRE WEATHER DAY. MONDAY-THURSDAY...A MORE ACTIVE PATTERN WILL DEVELOP IN THE LONG TERM. ALTHOUGH LONG TERM MODELS HAVE TYPICAL DIFFERENCES IN TIMING AND PLACEMENT OF A SYSTEM 5 TO 6 DAYS OUT...THEY ARE IN GENERAL AGREEMENT WITH A DECENT WARMUP INTO THE 70S FOLLOWED BY A MID PLAINS CYCLONE DEVELOPING AND WELCOMING SOME WELL NEEDED MOISTURE TO THE REGION. THERE IS THE POTENTIAL FOR A COUPLE OF DAYS OF PERIODIC RAIN SHOWERS AND PERHAPS SOME THUNDER AS A FRONTAL SYSTEM MOVES THROUGH. THE MIDDLE OF THE WEEK IS SHOWING THE BEST AGREEMENT FOR PRECIPITATION AND PLANS TO CHANGE THE CHANCE POPS IN FOR DAYS 5 AND 6. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 644 PM CDT THU APR 9 2015 CIGS HAVE ALL BE VFR AS THERE HAS BEEN A FAIR AMOUNT OF MID LEVEL CU AS A COLD FRONT MOVES THROUGH THE AREA. THE WINDS HAVE BECOME QUITE STRONG AS THE FRONT MOVES THROUGH SO BUMPED UP SPEEDS TO 15 TO 20 SUSTAINED WITH GUSTS NEAR 25 KTS AT TIMES. SOME MVFR CIGS WILL MOVE INTO KTVF AND KBJI LATER TONIGHT AS THE MAIN UPPER LOW DIGS DOWN INTO THE AREA...ALONG WITH SOME SCATTERED RAIN OR SNOW SHOWERS. WILL KEEP THE SITES FURTHER WEST VFR AND DRY. ALL SITES SHOULD BE VFR BY MID MORNING TOMORROW AND WINDS SHOUL BEGIN TO SETTLE DOWN. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...JR SHORT TERM...TG LONG TERM...TG/SPEICHER AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
632 PM CDT THU APR 9 2015 .UPDATE... ISSUED AT 623 PM CDT THU APR 9 2015 GUSTY WEST TO NORTHWEST WINDS STILL ON TRACK TO DIMINISH BY AROUND SUNSET. OTHERWISE...A QUIET EVENING IS EXPECTED AS SKIES CLEAR UP AND ISOLATED LIGHT SHOWERS COME TO AN END LATER THIS EVENING. UPDATES HAVE BEEN SENT. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 323 PM CDT THU APR 9 2015 FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE ISOLATED SHOWERS AND GUSTY WINDS THROUGH EARLY THIS EVENING. OTHERWISE A QUIET TONIGHT AND FRIDAY. CURRENTLY...NORTHERLY FLOW ALOFT WITH A WEAK RIDGE ACROSS THE NORTHERN ROCKIES AND A STRONG S/WV MOVING SOUTH TOWARDS NORTHERN MINNESOTA. LARGE CU FIELD DEVELOPING AS EXPECTED THIS AFTERNOON AHEAD OF AN INVERTED SFC TROUGH/FRONTAL BOUNDARY NOW PUSHING SOUTH ACROSS NORTHERN NORTH DAKOTA. A FEW SHOWERS POPPING UP WITHIN THE CU AS THE HRRR AND 4KM WRF ADVERTISED. DOUBTFUL MUCH WILL REACH THE GROUND BUT WILL MAINTAIN SHOWERS IN THE FORECAST NOW THROUGH 03Z. WINDS GUSTING TO AROUND 30KTS AS WE MIX TO AROUND 700MB AND SHOULD CONTINUE UNTIL AROUND SUNDOWN...THEN DISSIPATE QUICKLY. WINDS WILL BE ENHANCED BY THE SHOWER ACTIVITY...AIDED WITH EVAPORATIONAL COOLING BENEATH THE CLOUD BASES AS PRECIPITATION FALLS. SURFACE HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS TONIGHT CLEARING THE SKY. HIGH PRESSURE CONTINUES SOUTH AND EAST FRIDAY ALLOWING FOR RETURN FLOW/WAA INTO THE REGION. DECENT DAY FRIDAY WITH HIGHS IN THE 50S AND A RELATIVELY LIGHT WIND AND MOSTLY SUNNY SKY. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 323 PM CDT THU APR 9 2015 THE MAIN FORECAST ISSUES IN THE LONG TERM INCLUDE STRONG AND GUSTY NORTHWEST WINDS SUNDAY - WITH POTENTIAL FIRE WEATHER ISSUES - AND AN UPPER LEVEL LOW/TROUGH SETTING UP FOR NEXT WEDNESDAY/THURSDAY. FRIDAY NIGHT AND SATURDAY: HIGH PRESSURE EXITS THE AREA TO THE EAST AS LOW PRESSURE DEVELOPS IN THE LEE OF THE ROCKIES AND APPROACHES NORTH DAKOTA. BY SATURDAY AFTERNOON AN UPPER LEVEL TROUGH EXPANDS EASTWARD AND SOUTHWEST FLOW ALOFT IS ESTABLISHED OVER THE NORTHERN PLAINS. MEANWHILE A SURFACE WARM FRONT IS EXPECTED TO ENTER WESTERN NORTH DAKOTA...WITH HIGHS REACHING THE UPPER 60S AND LOWER 70S. SATURDAY NIGHT: UPPER LEVEL ENERGY REACHES NORTH DAKOTA AHEAD OF AND ALONG AN ASSOCIATED COLD FRONT. CHANCE OF SHOWERS...MAINLY NORTH AND WEST. SUNDAY: THE COLD FRONT PUSHES SOUTHEAST ACROSS THE STATE EARLY SUNDAY MORNING...WITH STRONG NORTHWEST WINDS OF 20 TO 35 MPH WITH GUSTS TO 40 MPH POSSIBLE. SEE THE FIRE WEATHER DISCUSSION BELOW FOR FIRE WEATHER CONCERNS. MONDAY AND TUESDAY SHOULD BE DRY WITH HIGHS IN THE 60S MONDAY...AND 65 TO 75 TUESDAY. THE NEXT UPPER LEVEL TROUGH MOVES ACROSS THE ROCKIES AND EMERGES IN THE WESTERN PLAINS TUESDAY NIGHT...CROSSING THE PLAINS WEDNESDAY AND THURSDAY. CHANCES OF RAIN SHOWERS INCREASE DURING THIS TIME...WITH HIGHS 50 TO 60 WEDNESDAY...AND UPPER 40S TO LOWER 50S THURSDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 623 PM CDT THU APR 9 2015 GUSTY WEST TO NORTHWEST WINDS WILL DIMINISH AROUND SUNSET THIS EVENING. VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. && .FIRE WEATHER... ISSUED AT 323 PM CDT THU APR 9 2015 SUNDAY: STRONG NORTHWEST WINDS OF 20 TO 35 MPH WITH GUSTS TO 40 MPH POSSIBLE. HIGHS OF 55 TO 60 EXPECTED...WITH MINIMUM RELATIVE HUMIDITY VALUES AROUND 20 PERCENT SOUTHWEST TO AROUND 25 PERCENT NORTHWEST AND CENTRAL. WILL CONTINUE TO MONITOR FOR POSSIBLE FIRE WEATHER WATCH. RECENT RAIN AND SNOWFALL OVER THE REGION IS NOTED...AND WEATHER DORMANT GRASSES WILL HAVE TIME TO DRY OUT IS THE MAIN QUESTION. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJS SHORT TERM...JV LONG TERM...NH AVIATION...JJS FIRE WEATHER...JV
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1158 PM CDT TUE APR 7 2015 .UPDATE... ISSUED AT 1158 PM CDT TUE APR 7 2015 INCLUDED A BIT OF MIXED PRECIP IN THE SOUTHEASTERN COUNTIES AS PRECIP WINDS DOWN. A FEW SPOTS HAVE REPORTED SOME SLEET. SHOULD NOT LAST TOO MUCH LONGER. UPDATE ISSUED AT 945 PM CDT TUE APR 7 2015 PRECIP CURRENTLY STRETCHING FROM LAKE OF THE WOODS DOWN IN A NARROWING BAND TOWARDS FARGO. THE PRECIP SHOULD CONTINUE TO PUSH EASTWARD AS A RAIN/SNOW MIX AND ADJUSTED GRIDS TO REFLECT THE RADAR TRENDS AND RAP/HRRR WHICH SEEM TO HAVE A GOOD HANDLE ON THE PRECIP. THE 21Z SREF HAS BACKED OFF ON THE VERY HIGH PROBABILITIES OF LOW VISIBILITY IN THE NORTHWESTERN COUNTIES...BUT THE RAP AND HRRR STILL HAVE SOME FOG FORMATION. A FEW SPOTS IN THE JAMES AND SHEYENNE VALLEYS HAVE SEEN DROPS IN VISIBILITY SO WILL KEEP THE PATCHY/AREAS OF FOG FORMATION FOR NOW BUT AT THIS POINT DO NOT THINK WE WILL GET A LOT OF SUPER DENSE FOG. UPDATE ISSUED AT 652 PM CDT TUE APR 7 2015 TWEAKED POPS FOR CURRENT RADAR TRENDS...THINK THAT THE PRECIP SHOULD CONTINUE TO MOVE EASTWARD THROUGH THE RED RIVER VALLEY AND WILL BE MOSTLY IN WESTERN MINNESOTA BY LATE EVENING. REPORTS HAVE 1 TO 2 INCHES MAINLY IN THE NORTHERN COUNTIES...SO WILL KEEP THE 1-3 INCH ACCUMULATIONS NORTH OF HIGHWAY 2 THAT WE HAVE GOING. SREF PROBABILITIES AND HRRR VIS SHOW SOME FOG IN THE DEVILS LAKE BASIN TOWARDS MORNING. BUMPED UP MENTION TO AREAS OF FOG AND WILL KEEP AN EYE ON DENSITY FOR NOW. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 300 PM CDT TUE APR 7 2015 CHALLENGES CENTER AROUND PRECIP AND PRECIP TYPE THROUGH THU...THEN TEMPS. MODELS ARE IN PRETTY GOOD OVERALL AGREEMENT THROUGH FRIDAY...LEADING TO SOME INCREASED CONFIDENCE IN THIS FORECAST. FOR THE REST OF THIS AFTERNOON AND OVERNIGHT...THE BAND OF PRECIP WILL SLOWLY SHIFT FROM WEST TO EAST. THERE IS STRONG OMEGA/WAA IN THE MID LEVELS THAT SHOULD TARGET AREAS ALONG AND NORTH OF US HIGHWAY 2 THROUGH 6Z. EXPECT MOST SNOW IN THE FAR NORTH WITH A MIX OF RAIN/SNOW POSSIBLE FURTHER SOUTH AND PROBABLY JUST RAIN IN THE SOUTH. THERE COULD BE AN INCH OR 2 OF SNOW IN THE NORTH THROUGH THE OVERNIGHT...WITH SOME SLICK SPOTS IF SNOW RATES BECOME HIGH ENOUGH AND AFTER DARK. TEMPS WON/T FALL TOO MUCH OVERNIGHT GIVEN THE POTENTIAL OF LOW CLOUDS AND EVEN SOME PATCHY FOG LATE IN THE WEST. FOR NOW WON/T MENTION FOG...BUT POTENTIAL WILL HAVE TO BE MONITORED. FOR WED...IT SHOULD BE DRY FOR MOST OF THE DAY...WITH THE THREAT FOR SOME LIGHT PRECIP MOVING INTO THE WEST AND SOUTH TOWARDS 00Z THU. TEMPS SHOULD WARM A BIT FROM TODAY...AND HINGE LARGELY ON IF THERE IS ANY SUNSHINE. FOR WED NIGHT...THE COLUMN WILL SATURATE AS A LARGE STORM SYSTEM MOVES INTO THE CENTRAL PLAINS. EXPECT SOME RAIN INITIALLY IN THE SOUTH WITH PRECIP POSSIBLY MIXING WITH SOME SNOW FURTHER NORTH OVERNIGHT. NOT EXPECTING HEAVY PRECIP RATES WITH THIS SYSTEM...SO LITTLE IF ANY SNOW ACCUMS EXPECTED. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 300 PM CDT TUE APR 7 2015 FOR THURSDAY...ANY PRECIP SHOULD MOVE OUT OF THE SOUTHEAST FA BY 18Z. TEMPS WILL WARM A BIT FROM WED WITH SOME SUNSHINE EXPECTED. ON FRIDAY...ANOTHER DRY DAY IS EXPECTED WITH TEMPS SIMILAR TO THU. THERE WILL BE SOME COOL AIR ALOFT IN THE FAR NORTHEAST...AND CAN/T RULE OUT A SPRINKLE...BUT FOR NOW WILL KEEP IT DRY. FOR FRIDAY NIGHT THROUGH TUESDAY...WILL START OFF THE PERIOD WITH RIDGING AT 500MB AND THUS MILD TEMPS FOR SAT/SUN. THE 12Z GFS SHOWS A LITTLE PREFRONTAL PCPN ACROSS THE FA AS EARLY AS SATURDAY AFTERNOON...WHILE THE OTHER MODELS ARE DRY. THINK PCPN CHANCES WILL INCREASE AS A COLD FRONT MOVES THRU SUNDAY/SUN NIGHT. SHOULD STILL BE WARM ENOUGH THAT THIS PCPN WILL FALL AS RAIN. MORE UNCERTAINTY ENTERS THE FORECAST BY MON INTO TUE WITH THE 12Z GFS ESSENTIALLY DRY. ECMWF SHOWS A LITTLE LIGHT PCPN BUT CONFIDENCE PRETTY LOW AT THIS POINT. WILL KEEP THE LOW GUIDANCE PCPN CHANCES ON MONDAY BUT THINK THAT MAY BE OVERDONE. SHOULD BE A LITTLE COOLER MON/TUE BEHIND THE COLD FRONT BUT TEMPS STILL LOOK TO BE WARMER THAN NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1158 PM CDT TUE APR 7 2015 KDVL HAS ALREADY DROPPED BELOW IFR...EVERYONE ELSE IS CURRENTLY MVFR. CIGS SHOULD START TO DROP DOWN A BIT MORE IN THE VALLEY AND SOME VIS AROUND 2-5SM IS POSSIBLE. HAVE KDVL GOING DOWN TO 1SM OR SO EARLY THIS MORNING. SHOULD IMPROVE TO MVFR BY MID MORNING AND THEN VFR BY LATE IN THE PERIOD. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...JR SHORT TERM...DK LONG TERM...GODON/DK AVIATION...JR
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
829 PM EDT THU APR 9 2015 .SYNOPSIS... THUNDERSTORMS WANING TONIGHT. ROUND OF SHOWERS AND THUNDERSTORMS FRIDAY MORNING AHEAD OF COLD FRONT WHICH CROSSES MIDDAY. HIGH PRESSURE FOR THE WEEKEND. COLD FRONT CROSSES EARLY NEXT WEEK. && .NEAR TERM /THROUGH FRIDAY/... 800 PM UPDATE... FCST ON TRACK SAVE FOR WET BULB ADJUSTMENTS. WX QUIETING DOWN UNTIL THE MAIN PRE FRONTAL CONVECTION SHOWS UP EARLY FRI MORNING. PREV DISCN... YET ANOTHER CONVECTIVE COMPLEX DEVELOPING TO OUR WEST...HOWEVER THE MEAN FLOW TODAY LOOKS TO KEEP THE STRONGEST STORMS TO OUR WEST...OR JUST CLIPPING THE WESTERN CWA. THE HIGHEST ML CAPE REMAINS WEST OF CWA...AND WOULD EXPECT STRONGEST STORMS TO STICK CLOSER TO THIS. WE ARE STILL FIRMLY WITHIN THE WARM SECTOR HOWEVER WITH CONVECTION POPPING UP ACROSS WV SOUTHWEST INTO SOUTHERN KENTUCKY...SO WILL STILL HAVE SHOWERS AND THUNDERSTORMS DRIFTING NE ACROSS FORECAST AREA THIS AFTERNOON...INTO THIS EVENING ACROSS THE NORTH. THINK THE BEST CHANCE OF WIDESPREAD SEVERE THUNDERSTORMS WILL REMAIN MOSTLY WEST OF FORECAST AREA. IN CWA BEST CHANCE LOOKS TO BE IN THE WESTERN THIRD OF CWA...ALONG THE OHIO RIVER AND WEST THIS AFTERNOON INTO EVENING. USED THE HRRR TO TIME THE BEST POPS...ALTHOUGH ISOLATED TO SCATTERED CONVECTION IS TOUGH TO GET EXACT. LOW TO MID LEVEL FLOW IS GENERALLY OUT OF THE SOUTHWEST...20-30KTS AROUND 925 MB...UP TO 50-60KTS AT 500MB. THIS WILL KEEP THINGS MOVING WHICH SHOULD HELP WITH WATER CONCERNS. MAIN CONCERN WATER-WISE WILL BE TRAINING CELLS...ESPECIALLY ALONG ANY OUTFLOW BOUNDARIES THAT LINGER PARALLEL TO THE FLOW. NO REASON TO MAKE ANY CHANGES TO THE FLASH FLOOD WATCH. IN THE WETTER AREAS...THAT WERE HIT LAST NIGHT BY HEAVY RAIN...IT WOULD LIKELY ONLY TAKE 1-1.5 INCHES IN 3 HOURS OR LESS TO START CAUSING PROBLEMS AGAIN...WHILE AREAS THAT HAVE NOT RECEIVED AS MUCH RAIN OVER THE LAST DAY OR TWO IT WOULD TAKE 1.5-2 IN 3 HOURS. TRIED TO SHOW A BREAK LATE THIS EVENING INTO TONIGHT...AS CONVECTION FROM THIS AFTERNOON EXITS TO THE NE...AND A COLD FRONT FINALLY APPROACHES FROM THE WNW. STILL HAVE ISOLATED SHOWERS/STORMS MENTIONED THROUGH THE NIGHT...AS WE REMAIN IN THE WARM SECTOR. COLD FRONT ARRIVES TO WESTERN ZONES FRIDAY MORNING. GFS/ECMWF ARE FAIRLY SIMILAR IN TIMING WITH THE FRONT...WHILE NAM LAGS BEHIND A BIT. DID NOT CHANGE PREVIOUS FORECAST TIMING A WHOLE LOT...BUT DID INCREASE POPS. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... CURRENT FORECAST OF A DRY AND MILD WEEKEND CONTINUES ONT RACK...AS MODELS VERY CONSISTENT WITH HIGH PRESSURE DOMINATING THE OHIO VALLEY. LOOK FOR NEAR SEASONAL DAYTIME TEMPERATURES BUT CHILLY NIGHTS WITH A LARGE DIURNAL RANGE IN TEMPERATURES. && .LONG TERM /MONDAY THROUGH THURSDAY/... MODELS DEPICT ANOTHER FRONTAL SYSTEM MEANDERING BACK AND FORTH ACROSS OUR REGION FOR MUCH OF NEXT WEEK. WHILE SPECIFIC DETAILS MAY BE DIFFERENT FOR EACH SYSTEM THAT RUNS ALONG THIS FRONT...THE GENERAL SCENARIO IS FOR WARM...MOIST AND RELATIVELY UNSTABLE AIR IN PLACE TO PRESENT A CHANCE OF SHOWERS AND THUNDERSTORMS ANYTIME FOR MUCH OF THE WEEK. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... SEVERE THUNDERSTORM AT EKN AT 00Z MOVED QUICKLY OFF TO THE E. ANOTHER SEVERE THUNDERSTORM MOVING NE THROUGH THE POINT PLEASANT AREA WILL PASS JUST S OF PKB 0040Z. THERE MAY BE ADDITIONAL WIDELY SCATTERED THUNDERSTORMS FORMING IN THE AREA TONIGHT...BUT WITH THE LOSS OF HEATING...THUNDERSTORM ACTIVITY SHOULD CONTINUE TO WANE...ALLOWING FOR A QUIET OVERNIGHT. THAT REPRIEVE WILL NOT LAST LONG THOUGH. A COLD FRONT CHARGING THROUGH IL THIS EVENING WILL CROSS THE MIDDLE OHIO VALLEY AND CENTRAL APPALACHIANS FRI MORNING. THIS WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. WHILE THE STORMS CAN BE HEAVY AND STRONG...THEY ARE IN GENERAL NOT EXPECTED TO BE SEVERE AS THOSE THIS PAST AFTERNOON AND EVENING WERE. THE FRONT WILL CROSS LATE MORNING AND MIDDAY FRIDAY...FOLLOWED Y BRIEF MVFR CIGS AND THEN VFR FLIGHT CONDITIONS. ANOTHER MINOR DETAIL...AN MVFR STRATOCU DECK MAY APPROACH BKW FROM THE GREENBRIER VALLEY FOR A TIME OVERNIGHT...ESPECIALLY IF THE FLOW THERE VEERS FURTHER THAN 180. SFC FLOW WILL GENERALLY BE S TO SW OVERNIGHT...BECOMING GUSTY TOWARD FRI MORNING. STRONG AND GUSTY SW WINDS AHEAD OF THE FRONT WILL BECOME STRONG AND GUSTY W BEHIND THE FRONT BEFORE DIMINISHING LATE. MODERATE TO STRONG SW FLOW AHEAD OF THE FRONT WILL BECOME MODERATE W BEHIND THE FRONT FRI AFTERNOON. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SATURDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING AND RESTRICTIONS IN SHOWERS/STORMS COULD VARY. MVFR STRATOCU DECK MAY OR MAY NOT MAKE IT INTO BKW OVERNIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE FRI 04/10/15 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 CRW CONSISTENCY H H H H H H H H H H M M HTS CONSISTENCY H H H H H H H H H M M L BKW CONSISTENCY H H H M M M M M H H H M EKN CONSISTENCY M H H H H H H H H H H M PKB CONSISTENCY H H H H H H H H H M M L CKB CONSISTENCY H H H H H H H H H H M M AFTER 00Z SATURDAY... NO WIDESPREAD IFR CONDITIONS EXPECTED AT THIS TIME. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR WVZ005>011-013- 014-017-019-020. FLASH FLOOD WATCH THROUGH FRIDAY AFTERNOON FOR WVZ015-016-018- 024>032-037>040-046-047. OH...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR OHZ066-067-075- 076-083>087. KY...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ101>103-105. VA...NONE. && $$ SYNOPSIS...JMV/MZ NEAR TERM...TRM/MZ SHORT TERM...JMV LONG TERM...JMV AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
749 PM EDT THU APR 9 2015 .SYNOPSIS... LOW PRESSURE WILL MOVE THROUGH THE CENTRAL GREAT LAKES TONIGHT AND DRAG A COLD FRONT THROUGH THE AREA. A SECONDARY COLD FRONT WILL DROP ACROSS THE AREA FRIDAY EVENING. HIGH PRESSURE WILL BUILD IN FOR SATURDAY AND SUNDAY && .NEAR TERM /THROUGH FRIDAY NIGHT/... UPDATED FORECAST TO ALLOW FOR A LITTLE SUNSHINE IN NW OHIO. THE LOCAL AREA IS CURRENTLY PRETTY QUIET. WILL HAVE TO WAIT AND SEE IF CONVECTION NEAR CINCINNATI HOLDS TOGETHER. OTHER STORMS COULD ALSO DEVELOP THIS EVENING IN THE WEST BUT EXPECTED THE BRUNT OF THE PRECIP TONIGHT TO OCCUR AFTER MIDNIGHT AS COLD FRONT APPROACHES. PREVIOUS...USED A MIX OF THE HRRR AND SREF FOR TRENDS THROUGH THE EVENING AND OVERNIGHT. RAIN ACROSS NORTHERN OHIO SHIFTING NORTHEAST QUICKLY AND IS NOW MAINLY IN NERN OHIO AND NWRN PA. ANOTHER AREA OF SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE SOUTHERN AND EASTERN COUNTIES THROUGH THE EVENING AS WELL. NOT A LOT OCCURRING IN THE WESTERN HALF OF THE AREA ALTHOUGH DO EXPECT SCATTERED CONVECTION WILL DEVELOP/MOVE IN. THROUGH THE EARLY EVENING WILL SHIFT HIGH POPS NORTH OF THE AREA FOR A SHORT WHILE DROPPING MOST TO CHANCE. AFTER MIDNIGHT COLD FRONT MOVES IN FROM THE WEST. EXPECT SHOWERS AND THUNDERSTORMS ALONG AND AHEAD OF THE BOUNDARY. WILL HAVE CAT POPS COMING BACK FOR THE OVERNIGHT AND THEN WILL ATTEMPT TO MOVE THIS EAST DURING THE EARLY MORNING HOURS WHILE ALSO MOVING DRYING IN FROM THE WEST. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... FRIDAY MORNING 12Z THE COLD FRONT SHOULD BE JUST EAST OF KCLE WITH DRYING MOVING IN FROM THE WEST. WILL HANG ONTO A CHANCE OF THUNDER EAST THROUGH THE FIRST HALF OF THE MORNING BUT EXPECT PRECIP TO END BY LATE MORNING. WILL ALLOW FOR SS TO BREAK THROUGH DURING THE DAY BUT AM STILL A BIT SKEPTICAL GIVEN LOW LEVEL RH REMAINING ACROSS THE AREA. ANOTHER BIG CONCERN FOR FRIDAY WILL BE WINDS. 850MB FLOW INCREASES TO 50 KNOTS ACROSS THE AREA LATE TONIGHT WITH 40-45 KNOTS AT 925MB. THIS CONTINUES POST COLD FRONT. AT THIS TIME IT DOESNT LOOK LIKE WARNING LEVELS WILL BE REACHED BUT COULD REQUIRE A WIND ADVISORY. IF THIS CONTINUES WILL LIKELY ISSUE ON THE EVENING OR OVERNIGHT FORECAST PACKAGE. BOTH THE NAM AND GFS CONTINUE TO SHOW A SECONDARY COLD FRONT/UPPER SHORT WAVE MOVING THROUGH DURING THE EVENING AND EARLY OVERNIGHT FRIDAY NIGHT. WILL BRING CLOUDS BACK AS WELL AS A SMALL CHANCE POPS. DRY AIR AND HIGH PRESSURE BUILD IN FOR SATURDAY AND SUNDAY. && .LONG TERM /MONDAY THROUGH THURSDAY/... MODELS GENERALLY AGREE WITH WEAK COLD FRONT PUSHING SE ACROSS THE AREA MON SO WILL MAINTAIN DECENT THREAT FOR SHRA. THE FRONT IS SHOWN TO MOVE FAR ENOUGH SOUTH OF THE AREA TO PROBABLY ALLOW FOR DRY CONDITIONS ON TUE WITH WEAK HIGH PRESSURE OVER THE AREA. WED THRU FRI...A SLOW MOVING UPPER LOW OVER THE PLAINS WILL DRIFT NE CAUSING A LOW TO LIFT NE TOWARD LAKE MICHIGAN BY LATE FRI. THE STALLED FRONT WILL SLOWLY LIFT NORTH INTO THE REGION AS A WARM FRONT PROVIDING A FOCUS FOR SHRA AND TSRA TO START SPREADING NE OVER THE AREA WED INTO WED NIGHT AND CONTINUE ON THU...AND PROBABLY FOR SEVERAL MOVE DAYS AFTER THAT. TEMPS UNCERTAIN AS THE NORTHERN PART OF THE CWA MAY SEE NE WINDS AHEAD OF THE FRONT THUS PRODUCING A COOL FLOW OFF OF LAKE ERIE WHILE THE SOUTHERN COUNTIES HAVE A GOOD CHANCE OF SEEING TEMPS WELL INTO THE 60S ANY MAYBE SOME 70S. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... CLUSTERS OF THUNDERSTORMS WILL MOVE NORTHEAST INTO THE TOLEDO AREA BETWEEN 00Z AND 01Z THIS EVENING. MORE ACTIVITY WILL MOVE NORTHEAST AND MAY CLIP MANSFIELD AND AFFECT AKRON CANTON AND YOUNGSTOWN. SHOWERS SHOULD MOVE FAIRLY QUICKLY OUT OF ERIE IN THE NEXT HOUR. OTHERWISE...EXPECTING COLD FRONT TO MOVE THROUGH THE AREA TOMORROW MORNING AND WINDS WILL SHIFT TO A SOUTHWESTERLY DIRECTION. AT THIS TIME...LATEST MODELS ARE COMING IN STATING THAT IT WILL BE FAIRLY QUIET OVERNIGHT BUT CANT RULE OUT A FEW SHOWERS AND THUNDERSTORMS IN THE WARM SECTOR AHEAD OF THE COLD FRONT. WINDS WILL BE GUSTY BEHIND THE COLD FRONT THROUGH A GOOD PART OF THE DAY ON FRIDAY. IMPROVING CEILINGS EXPECTED ON FRIDAY FROM WEST TO EAST AND WINDS WILL BEGIN TO GRADUALLY DIMINISH AS WELL. .OUTLOOK..SOME NON VFR POSSIBLE ACROSS NW PA FOR EARLY SATURDAY MORNING. NON VFR POSSIBLE AGAIN FOR MONDAY. && .MARINE... A STRONG COLD FRONT SWEEPING ACROSS LAKE ERIE LATE TONIGHT AND FRIDAY MORNING AND THE FOLLOWING COLD ADVECTION SHOULD BE ABLE TO PRODUCE GALE FORCE WINDS FOR A WHILE. WILL GO WITH LOW END GALES FOR A WHILE ON FRI. THE PRESSURE GRADIENT STARTS TO WEAKEN LATER FRI INTO FRI NIGHT SO WINDS SHOULD SLOWLY START DIMINISHING THEN BECOME LIGHT BY SAT EVE AS HIGH PRESSURE MOVES ACROSS OHIO INTO PA. A RETURN SOUTHERLY FLOW SHOULD SET UP IN THE WAKE OF THE HIGH FOR SUN INCREASING TO ABOUT 10 TO 20 KNOTS FOR SUN NIGHT AHEAD OF A WEAK COLD FRONT THAT CROSSES THE LAKE MON. WEAK HIGH PRESSURE QUICKLY BUILDS IN BY MON NIGHT SO WINDS WILL DIMINISH AND SHOULD STAY FAIRLY LIGHT THRU TUE. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...FLASH FLOOD WATCH UNTIL 7 AM EDT FRIDAY FOR OHZ029>032-036>038- 047. PA...NONE. MARINE...GALE WARNING FROM 6 AM TO 4 PM EDT FRIDAY FOR LEZ061-142>149- 162>169. && $$ SYNOPSIS...TK NEAR TERM...TK/KUBINA SHORT TERM...TK LONG TERM...ADAMS AVIATION...LOMBARDY MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
633 PM EDT WED APR 8 2015 .SYNOPSIS... ROUNDS OF SHOWERS AND THUNDERSTORMS TONIGHT INTO THURSDAY NIGHT. COLD FRONT CROSSES FRIDAY. HIGH PRESSURE FOR THE WEEKEND. COLD FRONT APPROACHES AND THEN STALLS FOR UNSETTLED WEATHER EARLY NEXT WEEK. && .NEAR TERM /THROUGH THURSDAY/... 630 PM UPDATE... UPDATED POPS TO REFLECT NEXT COMPLEX COMING INTO OUR SRN AND CENTRAL ZONES AND THEN MOVING NEWD OVERNIGHT. ALSO WW33 IS GONE. PREV DISCN... BUSY DAY WITH LINE OF STRONG TO SEVERE STORMS CURRENTLY MOVING THROUGH CWA. THIS IS ASSOCIATED WITH MCV PASSING JUST TO OUR NORTH AND GOOD INFLOW INTO THE SOUTH. RELIED HEAVILY ON THE HRRR FOR TIMING OF THE LINE...WHICH IS MOVING ESE AROUND 40KTS. THINGS BECOME A BIT MORE UNCERTAIN TONIGHT...AS CONVECTION WILL BE LINGERING AROUND A WEAK BOUNDARY THAT SHOULD BE NEAR OUR SOUTHERN CWA BORDER. HRRR SHOWING TWO SEPARATE COMPLEXES MOVING ALONG THIS BOUNDARY THIS EVENING INTO TONIGHT. GENERALLY HAVE GOTTEN AROUND A HALF AN INCH IN TODAYS LINE OF CONVECTION...AND COULD GET ANOTHER HALF TO ONE INCH OVERNIGHT. BELIEVE IT WOULD TAKE AROUND 1.5 INCHES IN 3 HOURS TO START CREATING LOCAL PROBLEMS. THIS BOUNDARY WILL SLOWLY LIFT NORTH AS A WARM FRONT THURSDAY MORNING WITH SHOWERS AND T-STORMS. IN THE UNSTABLE WARM SECTOR...COULD AGAIN SEE STRONG TO SEVERE STORMS APPROACH FROM THE WEST THURSDAY AFTERNOON. ONLY MINIMAL CHANGES MADE TO TEMPERATURE FORECAST THROUGH THE PERIOD...AS EXISTING FORECAST LOOKED DECENT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... MODELS ARE IN GOOD AGREEMENT WITH THE STRONG COLD FRONT THAT MOVES ACROSS LATE THURSDAY NIGHT AND FRIDAY MORNING. LOTS OF JUICE AND GOOD DYNAMICS WILL BRING A BAND OF SHOWERS AND STRONG THUNDERSTORMS ALONG AND AHEAD OF THE FRONT. SHOWERS AND STORMS END FROM WEST TO EAST DURING FRIDAY...WITH THE FRONT EXITING THE MOUNTAINS BY LATER IN THE AFTERNOON. HIGH PRESSURE BUILDS IN FROM THE WEST FOR A DRY BUT COOLER START TO THE WEEKEND. ABOVE NORMAL TEMPERATURES FRIDAY AHEAD OF THE FRONT WILL LOWER TO NEAR OR SLIGHTLY BELOW NORMAL LEVELS BEHIND THE FRONT. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED PERIOD. WEEKEND STARTS OUT WARM AND DRY...AND HIGH PRESSURE...SURFACE AND ALOFT BUILDS IN. AN ACTIVE AND STORMY WEEK THEN TAKES HOLD NEXT WEEK...AS ANOTHER FRONTAL BOUNDARY...STALLS OUT ACROSS THE AREA BRIEFLY...BEFORE LIFTING BACK NORTH AS A WARM FRONT BY TUESDAY...WITH LOW PRESSURE MOVING NORTHEAST OUT OF THE SOUTHERN PLAINS TOWARDS THE OHIO VALLEY. THIS WILL PROVIDE THE SET UP FOR WARM...AND HUMID WEATHER ACROSS THE AREA...ALONG WITH CHANCES FOR THUNDERSTORMS IN THE INCREASINGLY MOIST AND UNSTABLE ATMOSPHERE. FOR NOW...BROAD BRUSHED POPS IN THE EXTENDED...WITH A DIURNAL TREND TO CONVECTION/HIGHER POPS. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... 630 PM UPDATE... UPDATED TAFS TO REFLECT CURRENT BREAK. MORE CONVECTION OVERSPREADS THE AREA TONIGHT AS THE NEXT COMPLEX COMES UP THE OHIO VALLEY FROM THE W. PREV DISCN... HAVE LINE OF THUNDERSTORMS MOVING ACROSS CWA...WITH IFR AND A PERIOD OF WINDS GUSTING 30-40 KTS. HAVE IFR AT HTS/PKB/CRW...BUT OPTED TO WAIT AT OTHER THREE SITES TO SEE HOW THINGS GO. STRONGEST PART OF THE LINE LOOKS TO BE HEADED ACROSS MIDDLE AND SOUTHERN CWA. OVERNIGHT...CANNOT RULE OUT A SHOWER OR THUNDERSHOWERS...BUT COVERAGE SHOULD NOT BE VERY WIDESPREAD. AS A WEAK WARM FRONT LIFTS NORTH ON THURSDAY...WILL HAVE A BETTER CHANCE OF SHOWERS AND STORMS. CANNOT RULE OUT SOME FOG TONIGHT WHERE IT HAS RAINED...ESPECIALLY IF FLOW DROPS OFF. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z FRIDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: TIMING/CATEGORY IN SHOWERS/STORMS MAY VARY. UNCERTAIN ON FOG FORMATION TONIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H M H H M H H H H H H H BKW CONSISTENCY H H H M M H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 00Z FRIDAY... BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS THROUGH FRIDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR WVZ005-006-013. OH...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR OHZ087. KY...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR KYZ101>103-105. VA...NONE. && $$ SYNOPSIS...TRM/JMV/MZ/SL NEAR TERM...TRM/MZ SHORT TERM...JMV LONG TERM...SL AVIATION...TRM/MZ
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
343 PM EDT WED APR 8 2015 .SYNOPSIS... A STATIONARY FRONT WILL REMAIN ACROSS THE AREA TONIGHT BUT SHOULD LIFT NORTH ON THURSDAY AHEAD OF LOW PRESSURE APPROACHING THE GREAT LAKES. THE LOW WILL MOVE ACROSS THE GREAT LAKES THURSDAY NIGHT AND WILL DRAG A COLD FRONT THROUGH ON FRIDAY. HIGH PRESSURE WILL BUILD IN FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... SHOWERS AND THUNDERSTORMS NOW IN THE EASTERN MOST COUNTIES OF THE CWA WITH THE REMAINDER OF THE AREA DRY. NEAR TERM HIGH REZ GUIDANCE HAS BEEN CHANGEABLE FOR THE EVENING AND FIRST HALF OF THE NIGHT...FIRST DEVELOPING PRECIP IN THE AREA THIS EVENING AND NOW NOT UNTIL MIDNIGHT OR SO NORTHWEST ON THE FRONT. WILL USE A BLEND OF THE NAM AND HRRR AND HAVE PRECIP EAST MOVING OUT DURING THE EVENING AND THEN MORE SHOWERS/THUNDER DEVELOPING TO OUR SOUTHWEST AND WEST DRIFTING INTO THE AREA THROUGH THE EVENING. OVERNIGHT CONTINUED TO INCREASE POPS TO CATEGORICAL FOR ALL BUT FAR NORTHEAST. TEMPS TOUGH WITH THE FRONT AND LAKE INFLUENCES. NEAR THE LAKE LOWS WILL BE IN THE LOWER 40S BUT INLAND A SHORT DISTANCE 50S LOOK BETTER. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/... THURSDAY THE FRONT WILL HAVE TURNED WARM AND MOVED NORTH OF MUCH OF THE AREA AHEAD OF LOW PRESSURE HEADING TOWARD THE CENTRAL LAKES. GUIDANCE SUGGESTS IT GETS STUCK LIFTING OUT OF NERN OHIO...POSSIBLY NEVER CLEARING OUT OF NWRN PA. WILL BE CLOSE. OTHERWISE DEEP MOISTURE ACROSS THE AREA WITH MODERATE AMOUNTS OF CAPE. GUIDANCE POPS HIGH AND WOULD BE TOUGH TO GO AGAINST THE TREND. WILL HAVE CAT POPS FOR SHOWERS AND THUNDERSTORMS. WITH WARM FRONT NORTH OF MOST HOWEVER TEMPS SHOULD TOUCH 70 MANY AREAS. CONTINUED WET THURSDAY NIGHT AS COLD FRONT TRAILING THE LOW MOVES THROUGH FROM WEST TO EAST. WILL CONTINUE WITH CAT POPS FOR SHOWERS AND THUNDERSTORMS. FRIDAY THE DEEP MOISTURE MOVES EAST. GUIDANCE SHOWS CLEARING MOVING IN FROM THE WEST ALTHOUGH MODELS ALSO SHOW QUITE A BIT OF LOW LEVEL (850MB) MOISTURE REMAINING IN THE AREA. NOT SURE I BUY THE RAPID CLEARING GUIDANCE IS FORECAST SO BACKED OFF THE SPEED AT WHICH THIS MOVES IN. THAT SHOULD RESULT IN A CLOUDY/MOSTLY CLOUDY START WITH COUNTIES BECOMING -PARTLY- SUNNY FROM SOUTHWEST TO EAST. FRIDAY NIGHT WILL HOLD ONTO A SMALL CHANCE POPS AS BOTH THE NAM AND GFS SHOW A SHORT WAVE MOVING THROUGH WITH A GENERAL LONG WAVE TROUGH ACROSS THE LAKES. DRY SATURDAY AND SATURDAY NIGHT BUT COOLER FOR THE WEEKEND WITH THE TROUGH ALOFT. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... MODELS IN GOOD AGREEMENT ON SUNDAY WITH HIGH PRESSURE SHIFTING EAST OF THE FORECAST AREA AND MOVING OFF THE MID ATLANTIC COAST. SO SUNDAY SHOULD BE WARMER AND DRY. TIMING OF THE NEXT SYSTEM STILL IN DOUBT...GFS BRINGS WARM FRONT INTO AREA WITH CHANCE OF PRECIP MONDAY NIGHT WHILE ECMWF A LITTLE SLOWER. FOR NOW WILL JUST GO LOW CHANCE POPS MONDAY NIGHT. BOTH MODELS CONTINUE TO MOVE THE NEXT WAVE THROUGH ON TUESDAY. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... FRONT LIFTED NORTH OF EVERYWHERE EXCEPT NW OH WHERE DENSE FOG WILL LINGER THIS EVENING. ELSEWHERE SCATTERED TSRA WILL MOVE EAST OF THE FORECAST BY EARLY EVENING. ANOTHER WAVE WILL DEVELOP TO THE WEST AND MOVE INTO THE AREA OVERNIGHT...TIMING OF WHICH IS STILL IN DOUBT. .OUTLOOK...NON VFR SHOULD IMPROVE WEST TO EAST ON FRI WITH PASSAGE OF COLD FRONT BUT AREAS OF NON VFR MAY HANG AROUND SNOWBELT INTO EARLY SATURDAY. && .MARINE... HAVE DROPPED THE SMALL CRAFT ADVISORY AS NE WINDS HAVE DIMINISHED TO 5 TO 15 KNOTS. TOMORROW THE WINDS SHIFT TO THE SOUTH AND INCREASE TO AROUND 20 KNOTS AHEAD OF NEXT SYSTEM. STRONG COLD FRONT WILL MOVE ACROSS THE LAKE FRIDAY MORNING. 925MB WINDS INCREASE TO 50 KNOTS...NOT SURE HOW MUCH OF THAT CAN MIX DOWN AHEAD OF FRONT SO WILL CONTINUE WITH 30 KNOTS IN THE FORECAST. COULD SEE A BRIEF PERIOD OF 35 KNOT GALES WITH THE FRONT ITSELF. WINDS DIMINISH QUICKLY BEHIND THE FRONT. HIGH PRESSURE BUILDS OVER THE LAKE SATURDAY AND WILL REMAIN OVER THE LAKE THROUGH THE END OF THE WEEKEND. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...TK NEAR TERM...TK SHORT TERM...TK LONG TERM...DJB AVIATION...DJB MARINE...DJB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
327 PM EDT WED APR 8 2015 .SYNOPSIS... ROUNDS OF SHOWERS AND THUNDERSTORMS TONIGHT INTO THURSDAY NIGHT. COLD FRONT CROSSES AT THE END OF THE WORK WEEK. HIGH PRESSURE FOR THE WEEKEND. && .NEAR TERM /THROUGH THURSDAY/... BUSY DAY WITH LINE OF STRONG TO SEVERE STORMS CURRENTLY MOVING THROUGH CWA. THIS IS ASSOCIATED WITH MCV PASSING JUST TO OUR NORTH AND GOOD INFLOW INTO THE SOUTH. RELIED HEAVILY ON THE HRRR FOR TIMING OF THE LINE...WHICH IS MOVING ESE AROUND 40KTS. THINGS BECOME A BIT MORE UNCERTAIN TONIGHT...AS CONVECTION WILL BE LINGERING AROUND A WEAK BOUNDARY THAT SHOULD BE NEAR OUR SOUTHERN CWA BORDER. HRRR SHOWING TWO SEPARATE COMPLEXES MOVING ALONG THIS BOUNDARY THIS EVENING INTO TONIGHT. GENERALLY HAVE GOTTEN AROUND A HALF AN INCH IN TODAYS LINE OF CONVECTION...AND COULD GET ANOTHER HALF TO ONE INCH OVERNIGHT. BELIEVE IT WOULD TAKE AROUND 1.5 INCHES IN 3 HOURS TO START CREATING LOCAL PROBLEMS. THIS BOUNDARY WILL SLOWLY LIFT NORTH AS A WARM FRONT THURSDAY MORNING WITH SHOWERS AND T-STORMS. IN THE UNSTABLE WARM SECTOR...COULD AGAIN SEE STRONG TO SEVERE STORMS APPROACH FROM THE WEST THURSDAY AFTERNOON. ONLY MINIMAL CHANGES MADE TO TEMPERATURE FORECAST THROUGH THE PERIOD...AS EXISTING FORECAST LOOKED DECENT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... MODELS ARE IN GOOD AGREEMENT WITH THE STRONG COLD FRONT THAT MOVES ACROSS LATE THURSDAY NIGHT AND FRIDAY MORNING. LOTS OF JUICE AND GOOD DYNAMICS WILL BRING A BAND OF SHOWERS AND STRONG THUNDERSTORMS ALONG AND AHEAD OF THE FRONT. SHOWERS AND STORMS END FROM WEST TO EAST DURING FRIDAY...WITH THE FRONT EXITING THE MOUNTAINS BY LATER IN THE AFTERNOON. HIGH PRESSURE BUILDS IN FROM THE WEST FOR A DRY BUT COOLER START TO THE WEEKEND. ABOVE NORMAL TEMPERATURES FRIDAY AHEAD OF THE FRONT WILL LOWER TO NEAR OR SLIGHTLY BELOW NORMAL LEVELS BEHIND THE FRONT. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED PERIOD. WEEKEND STARTS OUT WARM AND DRY...AND HIGH PRESSURE...SURFACE AND ALOFT BUILDS IN. AN ACTIVE AND STORMY WEEK THEN TAKES HOLD NEXT WEEK...AS ANOTHER FRONTAL BOUNDARY...STALLS OUT ACROSS THE AREA BRIEFLY...BEFORE LIFTING BACK NORTH AS A WARM FRONT BY TUESDAY...WITH LOW PRESSURE MOVING NORTHEAST OUT OF THE SOUTHERN PLAINS TOWARDS THE OHIO VALLEY. THIS WILL PROVIDE THE SET UP FOR WARM...AND HUMID WEATHER ACROSS THE AREA...ALONG WITH CHANCES FOR THUNDERSTORMS IN THE INCREASINGLY MOIST AND UNSTABLE ATMOSPHERE. FOR NOW...BROAD BRUSHED POPS IN THE EXTENDED...WITH A DIURNAL TREND TO CONVECTION/HIGHER POPS. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... HAVE LINE OF THUNDERSTORMS MOVING ACROSS CWA...WITH IFR AND A PERIOD OF WINDS GUSTING 30-40 KTS. HAVE IFR AT HTS/PKB/CRW...BUT OPTED TO WAIT AT OTHER THREE SITES TO SEE HOW THINGS GO. STRONGEST PART OF THE LINE LOOKS TO BE HEADED ACROSS MIDDLE AND SOUTHERN CWA. OVERNIGHT...CANNOT RULE OUT A SHOWER OR THUNDERSHOWERS...BUT COVERAGE SHOULD NOT BE VERY WIDESPREAD. AS A WEAK WARM FRONT LIFTS NORTH ON THURSDAY...WILL HAVE A BETTER CHANCE OF SHOWERS AND STORMS. CANNOT RULE OUT SOME FOG TONIGHT WHERE IT HAS RAINED...ESPECIALLY IF FLOW DROPS OFF. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: TIMING/CATEGORY IN SHOWERS/STORMS MAY VARY. UNCERTAIN ON FOG FORMATION TONIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H M H H M H H H H H H H BKW CONSISTENCY H H H M M H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z THURSDAY... BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS THROUGH FRIDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH THURSDAY MORNING FOR WVZ005-006-013. OH...FLASH FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH THURSDAY MORNING FOR OHZ087. KY...FLASH FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH THURSDAY MORNING FOR KYZ101>103-105. VA...NONE. && $$ SYNOPSIS...JMV/MZ/SL NEAR TERM...MZ SHORT TERM...JMV LONG TERM...SL AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
149 PM EDT WED APR 8 2015 .SYNOPSIS... ROUNDS OF SHOWERS AND THUNDERSTORMS TONIGHT INTO THURSDAY NIGHT. COLD FRONT CROSSES AT THE END OF THE WORK WEEK. HIGH PRESSURE FOR THE WEEKEND. && .NEAR TERM /THROUGH THURSDAY/... BUSY DAY WITH LINE OF STRONG TO SEVERE STORMS CURRENTLY MOVING THROUGH CWA. THIS IS ASSOCIATED WITH MCV PASSING JUST TO OUR NORTH AND GOOD INFLOW INTO THE SOUTH. RELIED HEAVILY ON THE HRRR FOR TIMING OF THE LINE...WHICH IS MOVING ESE AROUND 40KTS. THINGS BECOME A BIT MORE UNCERTAIN TONIGHT...AS CONVECTION WILL BE LINGERING AROUND A WEAK BOUNDARY THAT SHOULD BE NEAR OUR SOUTHERN CWA BORDER. THIS BOUNDARY WILL SLOWLY LIFT NORTH AS A WARM FRONT THURSDAY MORNING WITH SHOWERS AND T-STORMS. DO NOT EXPECT THE SHOWERS AND STORMS TONIGHT TO PRODUCING WIDESPREAD HEAVY RAIN...BUT AS GROUND CONTINUES TO SOAK UP MORE WATER...FLOODING CONCERNS WILL INCREASE. HOWEVER THINK ANY ISSUES THROUGH TONIGHT AND TOMORROW WOULD BE VERY LOCALIZED...SO OPTED TO NOT ISSUE ANY FLOOD HEADLINE AT THIS TIME. GENERALLY WILL GET AROUND HALF AN INCH WITH THIS INITIAL LINE...THEN COULD GET ANOTHER QUARTER TO HALF OVERNIGHT. BELIEVE IT WOULD TAKE AROUND 1.5 INCHES IN 3 HOURS TO START CREATING LOCAL PROBLEMS. ONLY MINIMAL CHANGES MADE TO TEMPERATURE FORECAST THROUGH THE PERIOD...AS EXISTING FORECAST LOOKED DECENT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... MODELS ARE IN GOOD AGREEMENT WITH THE STRONG COLD FRONT THAT MOVES ACROSS LATE THURSDAY NIGHT AND FRIDAY MORNING. LOTS OF JUICE AND GOOD DYNAMICS WILL BRING A BAND OF SHOWERS AND STRONG THUNDERSTORMS ALONG AND AHEAD OF THE FRONT. SHOWERS AND STORMS END FROM WEST TO EAST DURING FRIDAY...WITH THE FRONT EXITING THE MOUNTAINS BY LATER IN THE AFTERNOON. HIGH PRESSURE BUILDS IN FROM THE WEST FOR A DRY BUT COOLER START TO THE WEEKEND. ABOVE NORMAL TEMPERATURES FRIDAY AHEAD OF THE FRONT WILL LOWER TO NEAR OR SLIGHTLY BELOW NORMAL LEVELS BEHIND THE FRONT. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED PERIOD. WEEKEND STARTS OUT WARM AND DRY...AND HIGH PRESSURE...SURFACE AND ALOFT BUILDS IN. AN ACTIVE AND STORMY WEEK THEN TAKES HOLD NEXT WEEK...AS ANOTHER FRONTAL BOUNDARY...STALLS OUT ACROSS THE AREA BRIEFLY...BEFORE LIFTING BACK NORTH AS A WARM FRONT BY TUESDAY...WITH LOW PRESSURE MOVING NORTHEAST OUT OF THE SOUTHERN PLAINS TOWARDS THE OHIO VALLEY. THIS WILL PROVIDE THE SET UP FOR WARM...AND HUMID WEATHER ACROSS THE AREA...ALONG WITH CHANCES FOR THUNDERSTORMS IN THE INCREASINGLY MOIST AND UNSTABLE ATMOSPHERE. FOR NOW...BROAD BRUSHED POPS IN THE EXTENDED...WITH A DIURNAL TREND TO CONVECTION/HIGHER POPS. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... HAVE LINE OF THUNDERSTORMS MOVING ACROSS CWA...WITH IFR AND A PERIOD OF WINDS GUSTING 30-40 KTS. HAVE IFR AT HTS/PKB/CRW...BUT OPTED TO WAIT AT OTHER THREE SITES TO SEE HOW THINGS GO. STRONGEST PART OF THE LINE LOOKS TO BE HEADED ACROSS MIDDLE AND SOUTHERN CWA. OVERNIGHT...CANNOT RULE OUT A SHOWER OR THUNDERSHOWERS...BUT COVERAGE SHOULD NOT BE VERY WIDESPREAD. AS A WEAK WARM FRONT LIFTS NORTH ON THURSDAY...WILL HAVE A BETTER CHANCE OF SHOWERS AND STORMS. CANNOT RULE OUT SOME FOG TONIGHT WHERE IT HAS RAINED...ESPECIALLY IF FLOW DROPS OFF. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: TIMING/CATEGORY IN SHOWERS/STORMS MAY VARY. UNCERTAIN ON FOG FORMATION TONIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY M H H H H H H H H H H H HTS CONSISTENCY M M M M H H M H H H H H BKW CONSISTENCY H H H H H M M H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY M H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z THURSDAY... BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS THROUGH FRIDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/MZ/SL NEAR TERM...MZ SHORT TERM...JMV LONG TERM...SL AVIATION...MZ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
144 PM EDT WED APR 8 2015 .SYNOPSIS... A FRONTAL BOUNDARY NEAR THE AREA WILL KEEP CHANCES FOR SHOWERS IN AND THUNDERSTORMS IN THE FORECAST THROUGH FRIDAY MORNING. AFTER A COLD FRONT MOVES THROUGH FRIDAY MORNING HIGH PRESSURE WILL WORK INTO THE REGION FOR THE START OF THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ORGANIZED SYSTEM OF CONVECTION HAS MAINTAINED ITSELF UPON ENTRY INTO THE WESTERN PORTION OF THE CWA...AND SIGNS ARE THAT IT WILL CONTINUE TO HOLD TOGETHER AND MAY EVEN INTENSIFY SOME AS IT PROPAGATES EASTWARD ACROSS THE CWA FROM LATE MORNING THROUGH EARLY/MID AFTERNOON. SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR THE CWA MAINLY ALONG/SOUTH OF INTERSTATE 70. MAIN THREAT IS DAMAGING WIND GUSTS...ALTHOUGH THERE MAY BE LOCALIZED LARGE HAIL. SYNOPTICALLY...THERE IS A QUASI-STATIONARY BOUNDARY DRAPED ACROSS CENTRAL/WESTERN OHIO. NEAR THIS BOUNDARY AND TO IT/S SOUTH IS WHERE THE BEST MOISTURE/INSTABILITY WILL RESIDE AND WHERE THE SEVERE WEATHER POTENTIAL EXISTS. THIS BOUNDARY LIKELY DOESN/T MOVE MUCH DURING THE DAYTIME. THE FATE OF THIS MCS WILL HELP DETERMINE WHAT OCCURS LATER THIS AFTERNOON. CONVECTIVE EVOLUTION/DETAILS ARE QUITE UNCERTAIN IN THE WAKE ON THIS MCS AND DIFFERENT MODELS SHOW DIFFERENT SOLUTIONS. HAVE BEEN FOLLOWING NSSL WRF-ARW MOST CLOSELY UP TO THIS POINT...ALTHOUGH LATEST RUN OF THE HRRR HAS NOW PICKED UP THE MCS SHOWING A SIMILAR SOLUTION FOR WRF. THERE MAY BE A BREAK LULL IN ACTIVITY AFTER THIS MCS MOVES THROUGH ALTHOUGH THE TAIL OF IT MAY RE-ACTIVATE SOONER MAINLY ACROSS NORTHEAST KENTUCKY AND THEN ADDITIONAL THUNDERSTORM DEVELOPMENT THEN MAY FOLLOW SUIT THROUGH EVENING. POPS/WX HAVE BEEN RE-WORKED TO REFLECT THIS THINKING. HAVE LOWERED MAX BY A DEG OR TWO GIVEN LOTS OF CLOUDS/CONVECTION BUT STILL EXPECT CWA TO RISE AOA 70 FOR MAXIMA THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... EXPECT A LULL OR A DECREASE IN THE PRECIPITATION COVERAGE BRIEFLY AT THE START OF THE SHORT TERM. ANOTHER DISTURBANCE WILL MOVE THROUGH TONIGHT HOWEVER BRINGING A RETURN OF PRECIPITATION TO THE REGION. YET ANOTHER WAVE BRINGS ADDITIONAL SHOWERS AND THUNDERSTORMS TO THE FA ON THURSDAY. SOME OF THE THUNDERSTORMS ON THURSDAY MAY BE SEVERE WITH DAMAGING WINDS AND LARGE HAIL THE PRIMARY THREATS. A COLD FRONT APPROACHES THURSDAY EVENING AND MOVES THROUGH THE REGION THURSDAY NIGHT INTO FRIDAY MORNING. AS THIS STRONG COLD FRONT WORKS THROUGH THE REGION THERE IS THE POTENTIAL FOR A DAMAGING WIND THREAT. HIGH PRESSURE WILL THEN WORK INTO THE FA DURING THE DAY ON FRIDAY. COOLER AND DRIER AIR WILL WORK INTO THE AREA FOR THE START OF THE WEEKEND. NOT EXPECTING TEMPERATURES TO DROP MUCH WEDNESDAY NIGHT WITH LOW TEMPERATURES IN THE MIDDLE 50S TO THE LOW 60S. DECENT SOUTHERLY FLOW ON THURSDAY WILL ALLOW TEMPERATURES TO RISE INTO THE 70S TO AROUND 80. WIND GUSTS WILL REACH UP AROUND 35 MPH AT TIMES ON THURSDAY. ADDITIONAL WIND GUSTS ARE EXPECTED EARLY FRIDAY MORNING AS THE FRONT MOVES THROUGH AND THE WINDS PICK UP. CLOUD COVER IS EXPECTED TO DECREASE FRIDAY NIGHT. THIS WILL ALLOW TEMPERATURES TO DROP OFF FRIDAY NIGHT. WITH THE DECREASE IN CLOUDS AND THE COOLER AIR MASS WORKING INTO THE REGION ON FRIDAY TEMPERATURES WILL DROP DOWN INTO THE 30S ACROSS A LARGE PORTION OF THE FA FRIDAY NIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... SURFACE HIGH PRESSURE AND A DRIER AIRMASS WILL BUILD INTO THE AREA SATURDAY BEFORE SLIDING OFF TO THE EAST THROUGH THE DAY ON SUNDAY. HIGHS ON SATURDAY WILL BE NEAR OR SLIGHTLY BELOW NORMAL...RANGING FROM THE MID/UPPER 50S NORTH TO LOW 60S SOUTH. AS WE START TO GET INTO SOME RETURN FLOW...HIGHS ON SUNDAY WILL PUSH UP INTO THE 60S ACROSS THE ENTIRE FA. LOWS SATURDAY NIGHT WILL BE DEPENDENT ON HOW FAST THE HIGH BUILDS IN AND THEN PUSHES OFF TO THE EAST. WE MAY END UP WITH THE BEST RADIATIONAL COOLING ACROSS OUR WEST SATURDAY MORNING AND THEN OUR EAST FOR SATURDAY NIGHT/SUNDAY MORNING. WILL GENERALLY KEEP LOWS IN THE UPPER 30S TO LOWER 40S...BUT SOME COLDER READINGS WILL BE POSSIBLE IF OPTIMAL RADIATIONAL COOLING DEVELOPS. IN DEVELOPING WAA...EXPECT SCATTERED SHOWERS AND PERHAPS A FEW THUNDERSTORMS TO DEVELOP SUNDAY NIGHT. PCPN SHOULD THEN BECOME MORE WIDESPREAD MONDAY INTO MONDAY NIGHT AS SHORTWAVE ENERGY PUSHES EAST TOWARD THE REGION. EXPECT HIGHS ON MONDAY IN THE UPPER 60S TO LOWERS 70S. AS THE SHORT WAVE PUSHES OFF TO THE EAST...PCPN SHOULD TAPER OFF THROUGH THE DAY ON TUESDAY WITH HIGHS GENERALLY IN THE 60S. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... BRUNT OF THE MCS HAD MOVED EAST OF THE TERMINALS AS OF 17Z. STILL MAY HOLD ONTO MVFR CONDITIONS AT KCMH/KLCK FOR A COUPLE OF HOURS...BUT TREND FOR A RETURN TO VFR IS LIKELY THROUGH THE REST OF THE AFTERNOON. THERE IS LIKELY TO BE SOME RE-DEVELOPMENT OF THUNDERSTORMS LATER IN THE AFTERNOON/EVENING. THERE IS UNCERTAINTY REGARDING TIMING AND PLACEMENT...HOWEVER CONSENSUS IS FOR KCVG/KLUK TO HAVE THE BEST CHANCE FOR CONVECTION AND HAVE INCLUDED A TEMPO GROUP. JUST HAVE VCTS FOR THE REMAINING TERMINALS THIS EVENING. QUASI-STATIONARY BOUNDARY REMAINS IN PLACE TONIGHT/THURSDAY. DISTURBANCES RIDING ALONG THE BOUNDARY WILL KEEP A CHANCE OF SHOWERS/THUNDERSTORMS IN THE FORECAST. THERE MAY BE AN OVERNIGHT LULL BUT THUNDERSTORMS MAY RETURN AS EARLY AS THURSDAY MORNING TO THE TERMINALS. OUTLOOK...THUNDERSTORMS POSSIBLE THURSDAY NIGHT/EARLY FRIDAY MORNING AS A COLD FRONT MOVES THROUGH THE AREA. GUSTY WEST WINDS ARE EXPECTED BEHIND THE COLD FRONT ON FRIDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...NOVAK NEAR TERM...BPP SHORT TERM...NOVAK LONG TERM...JGL AVIATION...BPP
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
117 PM EDT WED APR 8 2015 .SYNOPSIS... A QUASI-STATIONARY FRONT WILL REMAIN OVER NORTHERN OHIO AND NORTHWEST PENNSYLVANIA TODAY THROUGH THURSDAY. A COLD FRONT WILL MOVE THROUGH THE REGION LATE THURSDAY NIGHT INTO FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATE...ADJUSTED TEMPS AGAIN BASED ON HRRR. POPS DECENT BUT TRIMMED BACK THE FOG TO THE WEST. ORIGINAL...THE SHOWER ACTIVITY FROM OVERNIGHT HAS DECREASED AS EXPECTED. SHOWERS AND A FEW THUNDERSTORMS ARE FORMING TO THE WEST AND THIS SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO INCREASE LATE THIS MORNING AND INTO THE AFTERNOON. PATCHY DENSE FOG HAS FORMED IN MANY LOCATIONS THIS MORNING...INCLUDING REPORTS IN NW PA. I WILL EXPAND THE MENTION OF PATCHY DENSE FOG TO ALMOST ALL AREAS FOR THE NEXT FEW HOURS. MINOR ADJUSTMENTS TO TEMPERATURES AND PRECIPITATION TO REFLECT THE CURRENT TRENDS. PREVIOUS DISCUSSION... THE STATIONARY FRONTAL BOUNDARY WILL REMAIN OVER NORTHERN OHIO AND NORTHWEST PA TODAY. LITTLE MOVEMENT IS EXPECTED WITH THE FRONT WHICH IS TYPICAL FOR THIS TIME OF YEAR AS THESE TYPE OF STATIONARY FRONTS SET UP ON THE SOUTH SHORE OF LAKE ERIE. SHOWERS ARE EXPECTED NEAR THE FRONTAL BOUNDARY TODAY BUT I DO NOT EXPECT WIDE SPREAD AREAL COVERAGE. IT WILL BE TOUGH TO PREDICT THE TIMING. LOCALIZED BOUNDARIES AND DAYTIME HEATING WILL MOST LIKELY TRIGGER THE SHOWERS. THIS IS RE-ENFORCED BY THE HRRR MODEL AS SEVERAL RUNS INDICATED SCATTERED/ISOLATED SHOWER PATTERN OVER THE REGION THROUGH THE DAY. I WILL KEEP HIGH CHANCE TO LOW LIKELY RANGED POPS OVER THE AREA. THUNDER IS POSSIBLE AND THE THREAT WILL INCREASE THIS AFTERNOON. THE STORM PREDICTION CENTER HAS PLACED SOME OF THE NORTHWEST AND NORTH CENTRAL OHIO IN A SLIGHT RISK CATEGORY FOR SEVERE THUNDERSTORMS TODAY. BIG TEMPERATURE GRADIENT AGAIN NORTH TO SOUTH ACROSS THE AREA. NORTHEAST FLOW NEAR THE LAKE WILL KEEP TEMPERATURES MUCH COOLER && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... THE STATIONARY FRONTAL BOUNDARY WILL REMAIN OVER THE FORECAST AREA WEDNESDAY NIGHT INTO THURSDAY. WITH THE LACK OF STRONG DYNAMICS EARLY IN THE PERIOD...THE SHOWERS WILL ONCE AGAIN BE DIFFICULT TO TIME. SHOWERS AND A FEW THUNDERSTORMS WILL REMAIN OVER THE AREA BUT IT WILL BE FAIRLY UNORGANIZED. AS THE SHORT WAVE IN ADVANCE OF THE COLD FRONT BEGINS TO MOVE TOWARDS THE AREA THURSDAY...THE STATIONARY FRONT WILL MOVE NORTHWARD AS A WARM FRONT AND THE UPPER LEVEL SUPPORT WILL BECOME MORE FOCUSED. A LARGE AREA OF Q-VECTOR CONVERGENCE IS NOTED THURSDAY NIGHT WITH THE UPPER LEVEL SYSTEM. THE SHOWER AND THUNDERSTORM ACTIVITY SHOULD BE MUCH MORE NUMEROUS AND ORGANIZED ON THURSDAY NIGHT AND SEVERE WEATHER THREAT IS STILL A QUESTION. THE TIMING IS NOT OPTIMAL AS THE BEST LIFT WILL OCCUR DURING THE OVERNIGHT HOURS. WE WILL STILL CONTINUE TO MONITOR THE THREAT. AT THIS TIME MOST OF THE FORECAST AREA HAS A MARGINAL RISK FOR SEVERE THUNDERSTORMS THURSDAY NIGHT. THE COLD FRONT WILL SWEEP ACROSS THE REGION ON FRIDAY. A FEW SHOWERS AND A POSSIBLE THUNDERSTORM MAY LINGER OVER THE EASTERN SECTIONS OF THE AREA FRIDAY MORNING BUT SHOWER ACTIVITY SHOULD RAPIDLY DECREASE IN THE AFTERNOON. DRY AIR AND COLD ADVECTION WILL OCCUR FRIDAY NIGHT. 850MB TEMPS AS LOW AS -8C COULD MOVE OVER THE LAKE FRIDAY NIGHT INTO EARLY SATURDAY. A FEW WET SNOW FLAKES ARE NOT OUT OF THE QUESTION FOR NE OH AND NW PA BUT I WILL LEAVE THE MENTION OF SNOW OUT OF THE FORECAST AT THIS TIME. THE AIR IS VERY DRY BEHIND THE FRONT AND IT MAY BE DIFFICULT TO GET ANY TYPE OF PRECIPITATION WITHOUT ASSISTANCE FROM THE LAKE. HIGH PRESSURE WILL BUILD OVER THE REGION LATE SATURDAY THROUGH SATURDAY NIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... HIGH PRESSURE OVER THE AREA SHOULD PROVIDE DRY CONDITIONS ON SUN AND ALLOW TEMPS TO MODERATE BACK A FEW DEGREES ABOVE NORMAL. THE DRY CONDITIONS WILL QUICKLY CHANGE GOING INTO SUN NIGHT AS RETURN FLOW MOISTURE ARRIVES ALONG WITH A WEAK COLD FRONT FROM THE WEST. WILL GENERALLY LEAVE SUN NIGHT FORECAST AS IS BUT ALLOW FOR A MORE UNIFORM PRECIP THREAT ON MON. MODELS TRYING TO SHOW A REPEAT SETUP OF THE CURRENT PATTERN WITH A FRONT STALLED NEAR THE AREA STARTING BY TUE AND LASTING ALL WEEK SO WILL INCREASE POPS A LITTLE MORE. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... FRONT LIFTED NORTH OF EVERYWHERE EXCEPT NW OH WHERE DENSE FOG WILL LINGER THIS EVENING. ELSEWHERE SCATTERED TSRA WILL MOVE EAST OF THE FORECAST BY EARLY EVENING. ANOTHER WAVE WILL DEVELOP TO THE WEST AND MOVE INTO THE AREA OVERNIGHT...TIMING OF WHICH IS STILL IN DOUBT. .OUTLOOK...NON VFR SHOULD IMPROVE WEST TO EAST ON FRI WITH PASSAGE OF COLD FRONT BUT AREAS OF NON VFR MAY HANG AROUND SNOWBELT INTO EARLY SATURDAY. && .MARINE... WILL LEAVE SCA FOR WEST PART OF THE LAKE GOING UNTIL 3 PM BUT COULD BE TAKEN DOWN SOONER IF FRONT LIFTS INTO NEARSHORE WATERS A LITTLE BEFORE THEN AND TURNS WINDS MORE SOUTH AT A DIMINISHED SPEED. MODELS INDICATE THE FRONT MAY SAG BACK SOUTH OF THE LAKE TOWARD EVENING...POSSIBLY DUE TO LAKE BREEZE ENHANCEMENT BUT THEN SHOULD START TO LIFT BACK INTO THE LAKE LATER IN THE NIGHT AND CONTINUE OFF TO THE NORTH ON THU. THE WARM AIR FLOWING OVER THE COLD LAKE SHOULD PROVIDE A STABILIZING EFFECT SO WILL CONTINUE TO KEEP WINDS UNDER 20 KTS UNTIL THU NIGHT WHEN LOW LEVEL FLOW INCREASES MORE AND STARTS TO TURN SW. THIS WILL PROVIDE MORE FAVORABLE CONDITIONS FOR WINDS TO INCREASE TO AT LEAST 15 TO 25 KNOTS. THE PASSAGE OF THE COLD FRONT LATE THU NIGHT AND FRI MORNING WILL TURN THE WINDS TO THE WEST AND AS COLDER AIR MOVES IN CAN SEE WINDS AROUND 30 KNOTS SO WILL INCREASE THE FORECAST. HIGH PRESSURE SLOWLY PUSHES INTO OH TO GRADUALLY DIMINISH THE WINDS FRI NIGHT THRU SAT SO THE SCA WILL END. NOT SURE IF THE ICE IS BROKEN UP ENOUGH OR NOT BUT THIS MAY BE THE EVENT WHERE THE ICE TYPICALLY GETS PUSHED INTO THE EAST END OF THE LAKE WITH THE STRONGER SW TO W WINDS. THE HIGH WILL SHIFT OFF THE MID ATLANTIC COAST BY SUN NIGHT TO ALLOW LIGHT WINDS TO TURN SE AND START TO INCREASE SOME. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR LEZ142>146. && $$ SYNOPSIS...GARNET NEAR TERM...GARNET/TK SHORT TERM...GARNET LONG TERM...ADAMS AVIATION...DJB MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1150 AM EDT WED APR 8 2015 .SYNOPSIS... A QUASI-STATIONARY FRONT WILL REMAIN OVER NORTHERN OHIO AND NORTHWEST PENNSYLVANIA TODAY THROUGH THURSDAY. A COLD FRONT WILL MOVE THROUGH THE REGION LATE THURSDAY NIGHT INTO FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATE...ADJUSTED TEMPS AGAIN BASED ON HRRR. POPS DECENT BUT TRIMMED BACK THE FOG TO THE WEST. ORIGINAL...THE SHOWER ACTIVITY FROM OVERNIGHT HAS DECREASED AS EXPECTED. SHOWERS AND A FEW THUNDERSTORMS ARE FORMING TO THE WEST AND THIS SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO INCREASE LATE THIS MORNING AND INTO THE AFTERNOON. PATCHY DENSE FOG HAS FORMED IN MANY LOCATIONS THIS MORNING...INCLUDING REPORTS IN NW PA. I WILL EXPAND THE MENTION OF PATCHY DENSE FOG TO ALMOST ALL AREAS FOR THE NEXT FEW HOURS. MINOR ADJUSTMENTS TO TEMPERATURES AND PRECIPITATION TO REFLECT THE CURRENT TRENDS. PREVIOUS DISCUSSION... THE STATIONARY FRONTAL BOUNDARY WILL REMAIN OVER NORTHERN OHIO AND NORTHWEST PA TODAY. LITTLE MOVEMENT IS EXPECTED WITH THE FRONT WHICH IS TYPICAL FOR THIS TIME OF YEAR AS THESE TYPE OF STATIONARY FRONTS SET UP ON THE SOUTH SHORE OF LAKE ERIE. SHOWERS ARE EXPECTED NEAR THE FRONTAL BOUNDARY TODAY BUT I DO NOT EXPECT WIDE SPREAD AREAL COVERAGE. IT WILL BE TOUGH TO PREDICT THE TIMING. LOCALIZED BOUNDARIES AND DAYTIME HEATING WILL MOST LIKELY TRIGGER THE SHOWERS. THIS IS RE-ENFORCED BY THE HRRR MODEL AS SEVERAL RUNS INDICATED SCATTERED/ISOLATED SHOWER PATTERN OVER THE REGION THROUGH THE DAY. I WILL KEEP HIGH CHANCE TO LOW LIKELY RANGED POPS OVER THE AREA. THUNDER IS POSSIBLE AND THE THREAT WILL INCREASE THIS AFTERNOON. THE STORM PREDICTION CENTER HAS PLACED SOME OF THE NORTHWEST AND NORTH CENTRAL OHIO IN A SLIGHT RISK CATEGORY FOR SEVERE THUNDERSTORMS TODAY. BIG TEMPERATURE GRADIENT AGAIN NORTH TO SOUTH ACROSS THE AREA. NORTHEAST FLOW NEAR THE LAKE WILL KEEP TEMPERATURES MUCH COOLER && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... THE STATIONARY FRONTAL BOUNDARY WILL REMAIN OVER THE FORECAST AREA WEDNESDAY NIGHT INTO THURSDAY. WITH THE LACK OF STRONG DYNAMICS EARLY IN THE PERIOD...THE SHOWERS WILL ONCE AGAIN BE DIFFICULT TO TIME. SHOWERS AND A FEW THUNDERSTORMS WILL REMAIN OVER THE AREA BUT IT WILL BE FAIRLY UNORGANIZED. AS THE SHORT WAVE IN ADVANCE OF THE COLD FRONT BEGINS TO MOVE TOWARDS THE AREA THURSDAY...THE STATIONARY FRONT WILL MOVE NORTHWARD AS A WARM FRONT AND THE UPPER LEVEL SUPPORT WILL BECOME MORE FOCUSED. A LARGE AREA OF Q-VECTOR CONVERGENCE IS NOTED THURSDAY NIGHT WITH THE UPPER LEVEL SYSTEM. THE SHOWER AND THUNDERSTORM ACTIVITY SHOULD BE MUCH MORE NUMEROUS AND ORGANIZED ON THURSDAY NIGHT AND SEVERE WEATHER THREAT IS STILL A QUESTION. THE TIMING IS NOT OPTIMAL AS THE BEST LIFT WILL OCCUR DURING THE OVERNIGHT HOURS. WE WILL STILL CONTINUE TO MONITOR THE THREAT. AT THIS TIME MOST OF THE FORECAST AREA HAS A MARGINAL RISK FOR SEVERE THUNDERSTORMS THURSDAY NIGHT. THE COLD FRONT WILL SWEEP ACROSS THE REGION ON FRIDAY. A FEW SHOWERS AND A POSSIBLE THUNDERSTORM MAY LINGER OVER THE EASTERN SECTIONS OF THE AREA FRIDAY MORNING BUT SHOWER ACTIVITY SHOULD RAPIDLY DECREASE IN THE AFTERNOON. DRY AIR AND COLD ADVECTION WILL OCCUR FRIDAY NIGHT. 850MB TEMPS AS LOW AS -8C COULD MOVE OVER THE LAKE FRIDAY NIGHT INTO EARLY SATURDAY. A FEW WET SNOW FLAKES ARE NOT OUT OF THE QUESTION FOR NE OH AND NW PA BUT I WILL LEAVE THE MENTION OF SNOW OUT OF THE FORECAST AT THIS TIME. THE AIR IS VERY DRY BEHIND THE FRONT AND IT MAY BE DIFFICULT TO GET ANY TYPE OF PRECIPITATION WITHOUT ASSISTANCE FROM THE LAKE. HIGH PRESSURE WILL BUILD OVER THE REGION LATE SATURDAY THROUGH SATURDAY NIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... HIGH PRESSURE OVER THE AREA SHOULD PROVIDE DRY CONDITIONS ON SUN AND ALLOW TEMPS TO MODERATE BACK A FEW DEGREES ABOVE NORMAL. THE DRY CONDITIONS WILL QUICKLY CHANGE GOING INTO SUN NIGHT AS RETURN FLOW MOISTURE ARRIVES ALONG WITH A WEAK COLD FRONT FROM THE WEST. WILL GENERALLY LEAVE SUN NIGHT FORECAST AS IS BUT ALLOW FOR A MORE UNIFORM PRECIP THREAT ON MON. MODELS TRYING TO SHOW A REPEAT SETUP OF THE CURRENT PATTERN WITH A FRONT STALLED NEAR THE AREA STARTING BY TUE AND LASTING ALL WEEK SO WILL INCREASE POPS A LITTLE MORE. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... WEST TO EAST LYING FRONT NEAR MFD WILL DRIFT SLOWLY NORTH TO THE SOUTH SHORE OF LAKE ERIE THIS AFTERNOON AND THEN WAVER SOME BEFORE HEADING OFF TO THE NORTH INTO FRI MORNING. GUIDANCE INDICATES IMPROVEMENT TO MVFR/LOW VFR LATE MORNING INTO MIDDAY SO WILL PLAY TAFS THAT WAY. SCT SHRA WILL AFFECT THE AREA THRU THE PERIOD. BETTER THREAT FOR TSRA THIS AFTERNOON AND TONIGHT AS AIRMASS BECOMES MORE UNSTABLE...BUT WHERE AND WHEN TSRA MAY OCCUR IS ANYBODY`S GUESS SO FOR NOW WILL KEEP OUT OF TAFS OTHER THAN MENTION WITH VCTS. CONDITIONS EXPECTED TO LOWER AGAIN BY LATE EVENING AS LOW LEVELS COOL A FEW DEGREES. .OUTLOOK...NON VFR SHOULD IMPROVE WEST TO EAST ON FRI WITH PASSAGE OF COLD FRONT BUT AREAS OF NON VFR MAY HANG AROUND SNOWBELT INTO EARLY SATURDAY. && .MARINE... WILL LEAVE SCA FOR WEST PART OF THE LAKE GOING UNTIL 3 PM BUT COULD BE TAKEN DOWN SOONER IF FRONT LIFTS INTO NEARSHORE WATERS A LITTLE BEFORE THEN AND TURNS WINDS MORE SOUTH AT A DIMINISHED SPEED. MODELS INDICATE THE FRONT MAY SAG BACK SOUTH OF THE LAKE TOWARD EVENING...POSSIBLY DUE TO LAKE BREEZE ENHANCEMENT BUT THEN SHOULD START TO LIFT BACK INTO THE LAKE LATER IN THE NIGHT AND CONTINUE OFF TO THE NORTH ON THU. THE WARM AIR FLOWING OVER THE COLD LAKE SHOULD PROVIDE A STABILIZING EFFECT SO WILL CONTINUE TO KEEP WINDS UNDER 20 KTS UNTIL THU NIGHT WHEN LOW LEVEL FLOW INCREASES MORE AND STARTS TO TURN SW. THIS WILL PROVIDE MORE FAVORABLE CONDITIONS FOR WINDS TO INCREASE TO AT LEAST 15 TO 25 KNOTS. THE PASSAGE OF THE COLD FRONT LATE THU NIGHT AND FRI MORNING WILL TURN THE WINDS TO THE WEST AND AS COLDER AIR MOVES IN CAN SEE WINDS AROUND 30 KNOTS SO WILL INCREASE THE FORECAST. HIGH PRESSURE SLOWLY PUSHES INTO OH TO GRADUALLY DIMINISH THE WINDS FRI NIGHT THRU SAT SO THE SCA WILL END. NOT SURE IF THE ICE IS BROKEN UP ENOUGH OR NOT BUT THIS MAY BE THE EVENT WHERE THE ICE TYPICALLY GETS PUSHED INTO THE EAST END OF THE LAKE WITH THE STRONGER SW TO W WINDS. THE HIGH WILL SHIFT OFF THE MID ATLANTIC COAST BY SUN NIGHT TO ALLOW LIGHT WINDS TO TURN SE AND START TO INCREASE SOME. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR LEZ142>146. && $$ SYNOPSIS...GARNET NEAR TERM...GARNET/TK SHORT TERM...GARNET LONG TERM...ADAMS AVIATION...ADAMS MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1038 AM EDT WED APR 8 2015 .SYNOPSIS... A WARM AND MOIST SOUTH TO SOUTHWEST WIND FLOW WILL BRING ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGHOUT THE WEEK. COLD FRONT CROSSES AT THE END OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... 1025 AM UPDATE...THE 12Z HRRR HAS FINALLY LATCHED ON TO CONVECTION COMING ACROSS INDIANA...UP TO THIS POINT EVERYTHING TRIED TO KEEP ACTIVITY WELL TO OUR NORTH...BUT THE RECENT HRRR AND NEW 12Z NAM AS ITS JUST ROLLING IN ARE MUCH MORE BELIEVABLE ROLLING A LINE OF CONVECTION ACROSS SOUTHERN OHIO LATE THIS MORNING INTO THIS AFTERNOON. RELIED VERY HEAVILY ON THE 12Z HRRR TO UPDATE POPS. THINGS MAY BE SPEEDING UP JUST A TOUCH...SO MAY NEED TO ADJUST TIMING AGAIN IN A COUPLE HOURS AS THINGS APPROACH. DECENT LINE...ALTHOUGH HAVE NOT SEEN ANY SEVERE LEVEL LSRS OUT OF UPSTREAM OFFICES...BUT EXPECT AT LEAST SOME RISK OF SEVERE LEVEL WINDS AS THIS LINE CONTINUES TOWARD US. HAVE COORDINATED A SEVERE THUNDERSTORM WATCH INTO OUR WESTERN COUNTIES. PREVIOUS DISCUSSION... MESO NAM SHOWS A BOUNDARY MOVING INTO THE FORECAST AREA THIS AFTERNOON PRODUCING SHOWERS AND THUNDERSTORMS. TRACING THIS BOUNDARY BACK TO THE CURRENT TIME...IT MATCHES WELL WITH CONVECTION OVER MISSOURI AND IOWA. THEREFORE...WILL CONTINUE WITH LIKELY POPS PROPAGATING WEST TO EAST DURING THE AFTERNOON HOURS. WITH THIS BAND HITTING DURING THE AFTERNOON HOURS...AM A BIT CONCERNED ABOUT THE POTENTIAL FOR FLOODING. HOWEVER...NAM IS SHOWING THE BAND ORIENTATION IS PERPENDICULAR TO THE STORM MOVEMENT WITH A DECENT 15 KNOT MOVEMENT. IN ADDITION...PRECIPITABLE WATER IS NOT THAT HIGH. THEREFORE...WILL HOLD OFF ON A WATCH FOR NOW AND CONTINUE TO HIGHLIGHT IN THE HWO. NAM HAS ANOTHER DISTURBANCE MOVING OVER TONIGHT THAT IS NOT REFLECTED IN THE GFS. THIS BAND ORIGINATES FROM A VORTICITY LOBE DURING CONVECTION THIS AFTERNOON. THAT LEADS TO A LOWER CONFIDENCE...SO WILL BE FAIRLY GENERIC WITH POPS. && .SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... WARMEST DAY OF THE WEEK STILL SHAPING UP FOR WEDNESDAY. STILL TRICKY FORECASTING HIGHS AS AREA WILL BE BATTLING SHRA/TSRA CHANCES...ESPECIALLY EARLY AND ACROSS SE OH AND N WV. WILL ROLL A MIDDLE GROUND SOLUTION WITH LOW 80S...PRIMARILY ACROSS S ZONES. IT WILL BE BREEZY AMID STRENGTHENING S FLOW. CANT RULE OUT A FEW SHRA AND TSRA IN THE AFTERNOON. SOME OF THESE STORMS COULD BE STRONG TO SVR...ESPECIALLY ACROSS SE OH. A BREEZY AND WARM NIGHT THURSDAY NIGHT WITH THE COLD FRONT MAKING AN APPROACH ON OUR WESTERN FLANK AFTER MIDNIGHT. MODELS CONTINUE TO SPEED UP THE FRONT...NOW BLOWING IT THRU BY MIDDAY FRIDAY. SO...HAVE THE BOUNDARY CROSSING THE OH RIVER 12Z FRIDAY AND C WV 15Z...EXITING THE MOUNTAINS BY 18Z. WILL HAVE SOME FRONTAL SHRA/TSRA TO CONTEND WITH...SOME OF WHICH COULD BE STRONG TO LOW END SVR AS HIGHLIGHTED BY SPC CONVECTIVE OUTLOOK. CLEARING WILL TAKE PLACE IN THE FRESHENING POSTFRONTAL AIRMASS FRIDAY NIGHT. THIS WILL TAKE US INTO WHAT WILL BE A STELLAR WEEKEND...WITH MILD DAYTIME TEMPS AND A PARTLY CLOUDY SKY. TI WILL CHILL OFF PRETTY GOOD SATURDAY NIGHT WITH HIGH PRESSURE OVERHEAD WITH A FROST CONCERN FOR THE LOWLANDS. && .LONG TERM /SUNDAY THROUGH TUESDAY/... MODELS ARE QUICKER WITH THE COLD FRONTAL PASSAGE ON FRIDAY LEAVING FRIDAY NIGHT MOSTLY DRY. THE OUTLIER IS THE ECMWF WHICH LAGS ABOUT 6 HOURS IN ITS QPF FIELD. WENT WITH THE CONSENSUS OF MODELS WITH A FASTER SOLUTIONS. HIGH PRESSURE BRINGS WIDESPREAD DRY WEATHER FRIDAY NIGHT THROUGH THE WEEKEND. ANOTHER UPPER WAVE APPROACHES MONDAY BRINGING BACK CHANCES FOR PCPN ACROSS THE AREA. TEMPERATURES EXPECTED TO BE WARM REACHING THE UPPER 70S THROUGH THE PERIOD...EXCEPT FOR A SLIGHT COOL DOWN BEHIND THE COLD FRONT SATURDAY...GENERALLY IN THE MID TO UPPER 60S. WENT CLOSE TO WPC GUIDANCE WITH FEW TWEAKS THROUGH THE PERIOD. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... A STRATUS DECK ACROSS THE AREA THIS MORNING HAS SOME HOLES THAT HAVE ALLOWED PATCHY FOG. AFTER ANY MORNING FOG BURNS OFF THIS MORNING...EXPECT THE STRATUS DECK TO CHANGE INTO A CUMULUS DECK...GRADUALLY RISING DURING THE DAY. AN AREA OF SHOWERS AND THUNDERSTORMS IS EXPECTED THIS AFTERNOON...BEGINNING FIRST IN SOUTHEAST OHIO AND NORTHEASTERN KY...THEN PUSHING EASTWARD. BRIEF IFR RESTRICTIONS ARE POSSIBLE WITH THE STRONG CELLS. CLOUDS SHOULD GENERALLY BE VFR WEDNESDAY EVENING...BUT DEPENDING ON SKY COVER...SOME PATCHES OF FOG COULD ALSO FORM. SHOWERS AND THUNDERSTORMS WILL REMAIN A POSSIBILITY TONIGHT. THE HEIGHT OF ANY CLOUD DECKS LATE TONIGHT IS HARD TO FORECAST...AS MOISTURE AT MOST LEVELS COULD FORM A CLOUD DECK. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY... FORECAST CONFIDENCE: MEDIUM TODAY...LOW TONIGHT. ALTERNATE SCENARIOS: TIMING AND DENSITY OF FOG THIS MORNING AND TONIGHT COULD VARY. STRONGER STORMS THIS AFTERNOON COULD CAUSE BRIEF IFR CONDITIONS. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21 CRW CONSISTENCY M H M H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H M H H H H H H H EKN CONSISTENCY M H H H H H H H H H H H PKB CONSISTENCY H H H M M M H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 12Z THURSDAY... BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS THROUGH FRIDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...ARJ/RPY/30 NEAR TERM...RPY/MZ SHORT TERM...30 LONG TERM...ARJ AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
941 AM EDT WED APR 8 2015 .SYNOPSIS... A QUASI-STATIONARY FRONT WILL REMAIN OVER NORTHERN OHIO AND NORTHWEST PENNSYLVANIA TODAY THROUGH THURSDAY. A COLD FRONT WILL MOVE THROUGH THE REGION LATE THURSDAY NIGHT INTO FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATE...ADJUSTED TEMPS BASED ON HRRR. ALSO ADJUSTED POPS. TRIED TO TIME CURRENT CONVECTION EAST ACROSS THE AREA BASED ON EXTRAPOLATION AND HRRR GUIDANCE. ORIGINAL...THE SHOWER ACTIVITY FROM OVERNIGHT HAS DECREASED AS EXPECTED. SHOWERS AND A FEW THUNDERSTORMS ARE FORMING TO THE WEST AND THIS SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO INCREASE LATE THIS MORNING AND INTO THE AFTERNOON. PATCHY DENSE FOG HAS FORMED IN MANY LOCATIONS THIS MORNING...INCLUDING REPORTS IN NW PA. I WILL EXPAND THE MENTION OF PATCHY DENSE FOG TO ALMOST ALL AREAS FOR THE NEXT FEW HOURS. MINOR ADJUSTMENTS TO TEMPERATURES AND PRECIPITATION TO REFLECT THE CURRENT TRENDS. PREVIOUS DISCUSSION... THE STATIONARY FRONTAL BOUNDARY WILL REMAIN OVER NORTHERN OHIO AND NORTHWEST PA TODAY. LITTLE MOVEMENT IS EXPECTED WITH THE FRONT WHICH IS TYPICAL FOR THIS TIME OF YEAR AS THESE TYPE OF STATIONARY FRONTS SET UP ON THE SOUTH SHORE OF LAKE ERIE. SHOWERS ARE EXPECTED NEAR THE FRONTAL BOUNDARY TODAY BUT I DO NOT EXPECT WIDE SPREAD AREAL COVERAGE. IT WILL BE TOUGH TO PREDICT THE TIMING. LOCALIZED BOUNDARIES AND DAYTIME HEATING WILL MOST LIKELY TRIGGER THE SHOWERS. THIS IS RE-ENFORCED BY THE HRRR MODEL AS SEVERAL RUNS INDICATED SCATTERED/ISOLATED SHOWER PATTERN OVER THE REGION THROUGH THE DAY. I WILL KEEP HIGH CHANCE TO LOW LIKELY RANGED POPS OVER THE AREA. THUNDER IS POSSIBLE AND THE THREAT WILL INCREASE THIS AFTERNOON. THE STORM PREDICTION CENTER HAS PLACED SOME OF THE NORTHWEST AND NORTH CENTRAL OHIO IN A SLIGHT RISK CATEGORY FOR SEVERE THUNDERSTORMS TODAY. BIG TEMPERATURE GRADIENT AGAIN NORTH TO SOUTH ACROSS THE AREA. NORTHEAST FLOW NEAR THE LAKE WILL KEEP TEMPERATURES MUCH COOLER && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... THE STATIONARY FRONTAL BOUNDARY WILL REMAIN OVER THE FORECAST AREA WEDNESDAY NIGHT INTO THURSDAY. WITH THE LACK OF STRONG DYNAMICS EARLY IN THE PERIOD...THE SHOWERS WILL ONCE AGAIN BE DIFFICULT TO TIME. SHOWERS AND A FEW THUNDERSTORMS WILL REMAIN OVER THE AREA BUT IT WILL BE FAIRLY UNORGANIZED. AS THE SHORT WAVE IN ADVANCE OF THE COLD FRONT BEGINS TO MOVE TOWARDS THE AREA THURSDAY...THE STATIONARY FRONT WILL MOVE NORTHWARD AS A WARM FRONT AND THE UPPER LEVEL SUPPORT WILL BECOME MORE FOCUSED. A LARGE AREA OF Q-VECTOR CONVERGENCE IS NOTED THURSDAY NIGHT WITH THE UPPER LEVEL SYSTEM. THE SHOWER AND THUNDERSTORM ACTIVITY SHOULD BE MUCH MORE NUMEROUS AND ORGANIZED ON THURSDAY NIGHT AND SEVERE WEATHER THREAT IS STILL A QUESTION. THE TIMING IS NOT OPTIMAL AS THE BEST LIFT WILL OCCUR DURING THE OVERNIGHT HOURS. WE WILL STILL CONTINUE TO MONITOR THE THREAT. AT THIS TIME MOST OF THE FORECAST AREA HAS A MARGINAL RISK FOR SEVERE THUNDERSTORMS THURSDAY NIGHT. THE COLD FRONT WILL SWEEP ACROSS THE REGION ON FRIDAY. A FEW SHOWERS AND A POSSIBLE THUNDERSTORM MAY LINGER OVER THE EASTERN SECTIONS OF THE AREA FRIDAY MORNING BUT SHOWER ACTIVITY SHOULD RAPIDLY DECREASE IN THE AFTERNOON. DRY AIR AND COLD ADVECTION WILL OCCUR FRIDAY NIGHT. 850MB TEMPS AS LOW AS -8C COULD MOVE OVER THE LAKE FRIDAY NIGHT INTO EARLY SATURDAY. A FEW WET SNOW FLAKES ARE NOT OUT OF THE QUESTION FOR NE OH AND NW PA BUT I WILL LEAVE THE MENTION OF SNOW OUT OF THE FORECAST AT THIS TIME. THE AIR IS VERY DRY BEHIND THE FRONT AND IT MAY BE DIFFICULT TO GET ANY TYPE OF PRECIPITATION WITHOUT ASSISTANCE FROM THE LAKE. HIGH PRESSURE WILL BUILD OVER THE REGION LATE SATURDAY THROUGH SATURDAY NIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... HIGH PRESSURE OVER THE AREA SHOULD PROVIDE DRY CONDITIONS ON SUN AND ALLOW TEMPS TO MODERATE BACK A FEW DEGREES ABOVE NORMAL. THE DRY CONDITIONS WILL QUICKLY CHANGE GOING INTO SUN NIGHT AS RETURN FLOW MOISTURE ARRIVES ALONG WITH A WEAK COLD FRONT FROM THE WEST. WILL GENERALLY LEAVE SUN NIGHT FORECAST AS IS BUT ALLOW FOR A MORE UNIFORM PRECIP THREAT ON MON. MODELS TRYING TO SHOW A REPEAT SETUP OF THE CURRENT PATTERN WITH A FRONT STALLED NEAR THE AREA STARTING BY TUE AND LASTING ALL WEEK SO WILL INCREASE POPS A LITTLE MORE. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... WEST TO EAST LYING FRONT NEAR MFD WILL DRIFT SLOWLY NORTH TO THE SOUTH SHORE OF LAKE ERIE THIS AFTERNOON AND THEN WAVER SOME BEFORE HEADING OFF TO THE NORTH INTO FRI MORNING. GUIDANCE INDICATES IMPROVEMENT TO MVFR/LOW VFR LATE MORNING INTO MIDDAY SO WILL PLAY TAFS THAT WAY. SCT SHRA WILL AFFECT THE AREA THRU THE PERIOD. BETTER THREAT FOR TSRA THIS AFTERNOON AND TONIGHT AS AIRMASS BECOMES MORE UNSTABLE...BUT WHERE AND WHEN TSRA MAY OCCUR IS ANYBODY`S GUESS SO FOR NOW WILL KEEP OUT OF TAFS OTHER THAN MENTION WITH VCTS. CONDITIONS EXPECTED TO LOWER AGAIN BY LATE EVENING AS LOW LEVELS COOL A FEW DEGREES. .OUTLOOK...NON VFR SHOULD IMPROVE WEST TO EAST ON FRI WITH PASSAGE OF COLD FRONT BUT AREAS OF NON VFR MAY HANG AROUND SNOWBELT INTO EARLY SATURDAY. && .MARINE... WILL LEAVE SCA FOR WEST PART OF THE LAKE GOING UNTIL 3 PM BUT COULD BE TAKEN DOWN SOONER IF FRONT LIFTS INTO NEARSHORE WATERS A LITTLE BEFORE THEN AND TURNS WINDS MORE SOUTH AT A DIMINISHED SPEED. MODELS INDICATE THE FRONT MAY SAG BACK SOUTH OF THE LAKE TOWARD EVENING...POSSIBLY DUE TO LAKE BREEZE ENHANCEMENT BUT THEN SHOULD START TO LIFT BACK INTO THE LAKE LATER IN THE NIGHT AND CONTINUE OFF TO THE NORTH ON THU. THE WARM AIR FLOWING OVER THE COLD LAKE SHOULD PROVIDE A STABILIZING EFFECT SO WILL CONTINUE TO KEEP WINDS UNDER 20 KTS UNTIL THU NIGHT WHEN LOW LEVEL FLOW INCREASES MORE AND STARTS TO TURN SW. THIS WILL PROVIDE MORE FAVORABLE CONDITIONS FOR WINDS TO INCREASE TO AT LEAST 15 TO 25 KNOTS. THE PASSAGE OF THE COLD FRONT LATE THU NIGHT AND FRI MORNING WILL TURN THE WINDS TO THE WEST AND AS COLDER AIR MOVES IN CAN SEE WINDS AROUND 30 KNOTS SO WILL INCREASE THE FORECAST. HIGH PRESSURE SLOWLY PUSHES INTO OH TO GRADUALLY DIMINISH THE WINDS FRI NIGHT THRU SAT SO THE SCA WILL END. NOT SURE IF THE ICE IS BROKEN UP ENOUGH OR NOT BUT THIS MAY BE THE EVENT WHERE THE ICE TYPICALLY GETS PUSHED INTO THE EAST END OF THE LAKE WITH THE STRONGER SW TO W WINDS. THE HIGH WILL SHIFT OFF THE MID ATLANTIC COAST BY SUN NIGHT TO ALLOW LIGHT WINDS TO TURN SE AND START TO INCREASE SOME. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR LEZ142>146. && $$ SYNOPSIS...GARNET NEAR TERM...GARNET/TK SHORT TERM...GARNET LONG TERM...ADAMS AVIATION...ADAMS MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
702 AM EDT WED APR 8 2015 .SYNOPSIS... A QUASI-STATIONARY FRONT WILL REMAIN OVER NORTHERN OHIO AND NORTHWEST PENNSYLVANIA TODAY THROUGH THURSDAY. A COLD FRONT WILL MOVE THROUGH THE REGION LATE THURSDAY NIGHT INTO FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE SHOWER ACTIVITY FROM OVERNIGHT HAS DECREASED AS EXPECTED. SHOWERS AND A FEW THUNDERSTORMS ARE FORMING TO THE WEST AND THIS SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO INCREASE LATE THIS MORNING AND INTO THE AFTERNOON. PATCHY DENSE FOG HAS FORMED IN MANY LOCATIONS THIS MORNING...INCLUDING REPORTS IN NW PA. I WILL EXPAND THE MENTION OF PATCHY DENSE FOG TO ALMOST ALL AREAS FOR THE NEXT FEW HOURS. MINOR ADJUSTMENTS TO TEMPERATURES AND PRECIPITATION TO REFLECT THE CURRENT TRENDS. PREVIOUS DISCUSSION... THE STATIONARY FRONTAL BOUNDARY WILL REMAIN OVER NORTHERN OHIO AND NORTHWEST PA TODAY. LITTLE MOVEMENT IS EXPECTED WITH THE FRONT WHICH IS TYPICAL FOR THIS TIME OF YEAR AS THESE TYPE OF STATIONARY FRONTS SET UP ON THE SOUTH SHORE OF LAKE ERIE. SHOWERS ARE EXPECTED NEAR THE FRONTAL BOUNDARY TODAY BUT I DO NOT EXPECT WIDE SPREAD AREAL COVERAGE. IT WILL BE TOUGH TO PREDICT THE TIMING. LOCALIZED BOUNDARIES AND DAYTIME HEATING WILL MOST LIKELY TRIGGER THE SHOWERS. THIS IS RE-ENFORCED BY THE HRRR MODEL AS SEVERAL RUNS INDICATED SCATTERED/ISOLATED SHOWER PATTERN OVER THE REGION THROUGH THE DAY. I WILL KEEP HIGH CHANCE TO LOW LIKELY RANGED POPS OVER THE AREA. THUNDER IS POSSIBLE AND THE THREAT WILL INCREASE THIS AFTERNOON. THE STORM PREDICTION CENTER HAS PLACED SOME OF THE NORTHWEST AND NORTH CENTRAL OHIO IN A SLIGHT RISK CATEGORY FOR SEVERE THUNDERSTORMS TODAY. BIG TEMPERATURE GRADIENT AGAIN NORTH TO SOUTH ACROSS THE AREA. NORTHEAST FLOW NEAR THE LAKE WILL KEEP TEMPERATURES MUCH COOLER && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... THE STATIONARY FRONTAL BOUNDARY WILL REMAIN OVER THE FORECAST AREA WEDNESDAY NIGHT INTO THURSDAY. WITH THE LACK OF STRONG DYNAMICS EARLY IN THE PERIOD...THE SHOWERS WILL ONCE AGAIN BE DIFFICULT TO TIME. SHOWERS AND A FEW THUNDERSTORMS WILL REMAIN OVER THE AREA BUT IT WILL BE FAIRLY UNORGANIZED. AS THE SHORT WAVE IN ADVANCE OF THE COLD FRONT BEGINS TO MOVE TOWARDS THE AREA THURSDAY...THE STATIONARY FRONT WILL MOVE NORTHWARD AS A WARM FRONT AND THE UPPER LEVEL SUPPORT WILL BECOME MORE FOCUSED. A LARGE AREA OF Q-VECTOR CONVERGENCE IS NOTED THURSDAY NIGHT WITH THE UPPER LEVEL SYSTEM. THE SHOWER AND THUNDERSTORM ACTIVITY SHOULD BE MUCH MORE NUMEROUS AND ORGANIZED ON THURSDAY NIGHT AND SEVERE WEATHER THREAT IS STILL A QUESTION. THE TIMING IS NOT OPTIMAL AS THE BEST LIFT WILL OCCUR DURING THE OVERNIGHT HOURS. WE WILL STILL CONTINUE TO MONITOR THE THREAT. AT THIS TIME MOST OF THE FORECAST AREA HAS A MARGINAL RISK FOR SEVERE THUNDERSTORMS THURSDAY NIGHT. THE COLD FRONT WILL SWEEP ACROSS THE REGION ON FRIDAY. A FEW SHOWERS AND A POSSIBLE THUNDERSTORM MAY LINGER OVER THE EASTERN SECTIONS OF THE AREA FRIDAY MORNING BUT SHOWER ACTIVITY SHOULD RAPIDLY DECREASE IN THE AFTERNOON. DRY AIR AND COLD ADVECTION WILL OCCUR FRIDAY NIGHT. 850MB TEMPS AS LOW AS -8C COULD MOVE OVER THE LAKE FRIDAY NIGHT INTO EARLY SATURDAY. A FEW WET SNOW FLAKES ARE NOT OUT OF THE QUESTION FOR NE OH AND NW PA BUT I WILL LEAVE THE MENTION OF SNOW OUT OF THE FORECAST AT THIS TIME. THE AIR IS VERY DRY BEHIND THE FRONT AND IT MAY BE DIFFICULT TO GET ANY TYPE OF PRECIPITATION WITHOUT ASSISTANCE FROM THE LAKE. HIGH PRESSURE WILL BUILD OVER THE REGION LATE SATURDAY THROUGH SATURDAY NIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... HIGH PRESSURE OVER THE AREA SHOULD PROVIDE DRY CONDITIONS ON SUN AND ALLOW TEMPS TO MODERATE BACK A FEW DEGREES ABOVE NORMAL. THE DRY CONDITIONS WILL QUICKLY CHANGE GOING INTO SUN NIGHT AS RETURN FLOW MOISTURE ARRIVES ALONG WITH A WEAK COLD FRONT FROM THE WEST. WILL GENERALLY LEAVE SUN NIGHT FORECAST AS IS BUT ALLOW FOR A MORE UNIFORM PRECIP THREAT ON MON. MODELS TRYING TO SHOW A REPEAT SETUP OF THE CURRENT PATTERN WITH A FRONT STALLED NEAR THE AREA STARTING BY TUE AND LASTING ALL WEEK SO WILL INCREASE POPS A LITTLE MORE. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... WEST TO EAST LYING FRONT NEAR MFD WILL DRIFT SLOWLY NORTH TO THE SOUTH SHORE OF LAKE ERIE THIS AFTERNOON AND THEN WAVER SOME BEFORE HEADING OFF TO THE NORTH INTO FRI MORNING. GUIDANCE INDICATES IMPROVEMENT TO MVFR/LOW VFR LATE MORNING INTO MIDDAY SO WILL PLAY TAFS THAT WAY. SCT SHRA WILL AFFECT THE AREA THRU THE PERIOD. BETTER THREAT FOR TSRA THIS AFTERNOON AND TONIGHT AS AIRMASS BECOMES MORE UNSTABLE...BUT WHERE AND WHEN TSRA MAY OCCUR IS ANYBODY`S GUESS SO FOR NOW WILL KEEP OUT OF TAFS OTHER THAN MENTION WITH VCTS. CONDITIONS EXPECTED TO LOWER AGAIN BY LATE EVENING AS LOW LEVELS COOL A FEW DEGREES. .OUTLOOK...NON VFR SHOULD IMPROVE WEST TO EAST ON FRI WITH PASSAGE OF COLD FRONT BUT AREAS OF NON VFR MAY HANG AROUND SNOWBELT INTO EARLY SATURDAY. && .MARINE... WILL LEAVE SCA FOR WEST PART OF THE LAKE GOING UNTIL 3 PM BUT COULD BE TAKEN DOWN SOONER IF FRONT LIFTS INTO NEARSHORE WATERS A LITTLE BEFORE THEN AND TURNS WINDS MORE SOUTH AT A DIMINISHED SPEED. MODELS INDICATE THE FRONT MAY SAG BACK SOUTH OF THE LAKE TOWARD EVENING...POSSIBLY DUE TO LAKE BREEZE ENHANCEMENT BUT THEN SHOULD START TO LIFT BACK INTO THE LAKE LATER IN THE NIGHT AND CONTINUE OFF TO THE NORTH ON THU. THE WARM AIR FLOWING OVER THE COLD LAKE SHOULD PROVIDE A STABILIZING EFFECT SO WILL CONTINUE TO KEEP WINDS UNDER 20 KTS UNTIL THU NIGHT WHEN LOW LEVEL FLOW INCREASES MORE AND STARTS TO TURN SW. THIS WILL PROVIDE MORE FAVORABLE CONDITIONS FOR WINDS TO INCREASE TO AT LEAST 15 TO 25 KNOTS. THE PASSAGE OF THE COLD FRONT LATE THU NIGHT AND FRI MORNING WILL TURN THE WINDS TO THE WEST AND AS COLDER AIR MOVES IN CAN SEE WINDS AROUND 30 KNOTS SO WILL INCREASE THE FORECAST. HIGH PRESSURE SLOWLY PUSHES INTO OH TO GRADUALLY DIMINISH THE WINDS FRI NIGHT THRU SAT SO THE SCA WILL END. NOT SURE IF THE ICE IS BROKEN UP ENOUGH OR NOT BUT THIS MAY BE THE EVENT WHERE THE ICE TYPICALLY GETS PUSHED INTO THE EAST END OF THE LAKE WITH THE STRONGER SW TO W WINDS. THE HIGH WILL SHIFT OFF THE MID ATLANTIC COAST BY SUN NIGHT TO ALLOW LIGHT WINDS TO TURN SE AND START TO INCREASE SOME. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR LEZ142>146. && $$ SYNOPSIS...GARNET NEAR TERM...GARNET SHORT TERM...GARNET LONG TERM...ADAMS AVIATION...ADAMS MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
602 AM EDT WED APR 8 2015 .SYNOPSIS... A QUASI-STATIONARY FRONT WILL REMAIN OVER NORTHERN OHIO AND NORTHWEST PENNSYLVANIA TODAY THROUGH THURSDAY. A COLD FRONT WILL MOVE THROUGH THE REGION LATE THURSDAY NIGHT INTO FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE SHOWER ACTIVITY FROM OVERNIGHT HAS DECREASED AS EXPECTED. SHOWERS AND A FEW THUNDERSTORMS ARE FORMING TO THE WEST AND THIS SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO INCREASE LATE THIS MORNING AND INTO THE AFTERNOON. PATCHY DENSE FOG HAS FORMED IN MANY LOCATIONS THIS MORNING...INCLUDING REPORTS IN NW PA. I WILL EXPAND THE MENTION OF PATCHY DENSE FOG TO ALMOST ALL AREAS FOR THE NEXT FEW HOURS. MINOR ADJUSTMENTS TO TEMPERATURES AND PRECIPITATION TO REFLECT THE CURRENT TRENDS. PREVIOUS DISCUSSION... THE STATIONARY FRONTAL BOUNDARY WILL REMAIN OVER NORTHERN OHIO AND NORTHWEST PA TODAY. LITTLE MOVEMENT IS EXPECTED WITH THE FRONT WHICH IS TYPICAL FOR THIS TIME OF YEAR AS THESE TYPE OF STATIONARY FRONTS SET UP ON THE SOUTH SHORE OF LAKE ERIE. SHOWERS ARE EXPECTED NEAR THE FRONTAL BOUNDARY TODAY BUT I DO NOT EXPECT WIDE SPREAD AREAL COVERAGE. IT WILL BE TOUGH TO PREDICT THE TIMING. LOCALIZED BOUNDARIES AND DAYTIME HEATING WILL MOST LIKELY TRIGGER THE SHOWERS. THIS IS RE-ENFORCED BY THE HRRR MODEL AS SEVERAL RUNS INDICATED SCATTERED/ISOLATED SHOWER PATTERN OVER THE REGION THROUGH THE DAY. I WILL KEEP HIGH CHANCE TO LOW LIKELY RANGED POPS OVER THE AREA. THUNDER IS POSSIBLE AND THE THREAT WILL INCREASE THIS AFTERNOON. THE STORM PREDICTION CENTER HAS PLACED SOME OF THE NORTHWEST AND NORTH CENTRAL OHIO IN A SLIGHT RISK CATEGORY FOR SEVERE THUNDERSTORMS TODAY. BIG TEMPERATURE GRADIENT AGAIN NORTH TO SOUTH ACROSS THE AREA. NORTHEAST FLOW NEAR THE LAKE WILL KEEP TEMPERATURES MUCH COOLER && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... THE STATIONARY FRONTAL BOUNDARY WILL REMAIN OVER THE FORECAST AREA WEDNESDAY NIGHT INTO THURSDAY. WITH THE LACK OF STRONG DYNAMICS EARLY IN THE PERIOD...THE SHOWERS WILL ONCE AGAIN BE DIFFICULT TO TIME. SHOWERS AND A FEW THUNDERSTORMS WILL REMAIN OVER THE AREA BUT IT WILL BE FAIRLY UNORGANIZED. AS THE SHORT WAVE IN ADVANCE OF THE COLD FRONT BEGINS TO MOVE TOWARDS THE AREA THURSDAY...THE STATIONARY FRONT WILL MOVE NORTHWARD AS A WARM FRONT AND THE UPPER LEVEL SUPPORT WILL BECOME MORE FOCUSED. A LARGE AREA OF Q-VECTOR CONVERGENCE IS NOTED THURSDAY NIGHT WITH THE UPPER LEVEL SYSTEM. THE SHOWER AND THUNDERSTORM ACTIVITY SHOULD BE MUCH MORE NUMEROUS AND ORGANIZED ON THURSDAY NIGHT AND SEVERE WEATHER THREAT IS STILL A QUESTION. THE TIMING IS NOT OPTIMAL AS THE BEST LIFT WILL OCCUR DURING THE OVERNIGHT HOURS. WE WILL STILL CONTINUE TO MONITOR THE THREAT. AT THIS TIME MOST OF THE FORECAST AREA HAS A MARGINAL RISK FOR SEVERE THUNDERSTORMS THURSDAY NIGHT. THE COLD FRONT WILL SWEEP ACROSS THE REGION ON FRIDAY. A FEW SHOWERS AND A POSSIBLE THUNDERSTORM MAY LINGER OVER THE EASTERN SECTIONS OF THE AREA FRIDAY MORNING BUT SHOWER ACTIVITY SHOULD RAPIDLY DECREASE IN THE AFTERNOON. DRY AIR AND COLD ADVECTION WILL OCCUR FRIDAY NIGHT. 850MB TEMPS AS LOW AS -8C COULD MOVE OVER THE LAKE FRIDAY NIGHT INTO EARLY SATURDAY. A FEW WET SNOW FLAKES ARE NOT OUT OF THE QUESTION FOR NE OH AND NW PA BUT I WILL LEAVE THE MENTION OF SNOW OUT OF THE FORECAST AT THIS TIME. THE AIR IS VERY DRY BEHIND THE FRONT AND IT MAY BE DIFFICULT TO GET ANY TYPE OF PRECIPITATION WITHOUT ASSISTANCE FROM THE LAKE. HIGH PRESSURE WILL BUILD OVER THE REGION LATE SATURDAY THROUGH SATURDAY NIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... HIGH PRESSURE OVER THE AREA SHOULD PROVIDE DRY CONDITIONS ON SUN AND ALLOW TEMPS TO MODERATE BACK A FEW DEGREES ABOVE NORMAL. THE DRY CONDITIONS WILL QUICKLY CHANGE GOING INTO SUN NIGHT AS RETURN FLOW MOISTURE ARRIVES ALONG WITH A WEAK COLD FRONT FROM THE WEST. WILL GENERALLY LEAVE SUN NIGHT FORECAST AS IS BUT ALLOW FOR A MORE UNIFORM PRECIP THREAT ON MON. MODELS TRYING TO SHOW A REPEAT SETUP OF THE CURRENT PATTERN WITH A FRONT STALLED NEAR THE AREA STARTING BY TUE AND LASTING ALL WEEK SO WILL INCREASE POPS A LITTLE MORE. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... FRONT IN CENTRAL OH WILL DRIFT SLOWLY NORTH TO BE NEAR LAKE ERIE BY MIDNIGHT. LITTLE WILL CHANGE INTO DAYLIGHT SO IFR SHOULD PREVAIL WITH SCT SHRA. GUIDANCE INDICATES IMPROVEMENT TO MVFR/LOW VFR LATE MORNING INTO MIDDAY. BETTER THREAT FOR TSRA THIS AFTERNOON AND EARLY TONIGHT AS AIRMASS BECOMES MORE UNSTABLE...BUT WHERE AND WHEN TSRA MAY OCCUR IS ANYBODY`S GUESS SO FOR NOW WILL KEEP OUT OF TAFS OTHER THAN MENTION WITH VCTS. CONDITIONS SHOULD START TO LOWER AGAIN BY LATE EVENING AS LOW LEVELS COOL A FEW DEGREES. .OUTLOOK...NON VFR AT TIMES INTO FRIDAY...POSSIBLY CONTINUING IN NW PA EARLY SATURDAY. && .MARINE... WILL LEAVE SCA FOR WEST PART OF THE LAKE GOING UNTIL 3 PM BUT COULD BE TAKEN DOWN SOONER IF FRONT LIFTS INTO NEARSHORE WATERS A LITTLE BEFORE THEN AND TURNS WINDS MORE SOUTH AT A DIMINISHED SPEED. MODELS INDICATE THE FRONT MAY SAG BACK SOUTH OF THE LAKE TOWARD EVENING...POSSIBLY DUE TO LAKE BREEZE ENHANCEMENT BUT THEN SHOULD START TO LIFT BACK INTO THE LAKE LATER IN THE NIGHT AND CONTINUE OFF TO THE NORTH ON THU. THE WARM AIR FLOWING OVER THE COLD LAKE SHOULD PROVIDE A STABILIZING EFFECT SO WILL CONTINUE TO KEEP WINDS UNDER 20 KTS UNTIL THU NIGHT WHEN LOW LEVEL FLOW INCREASES MORE AND STARTS TO TURN SW. THIS WILL PROVIDE MORE FAVORABLE CONDITIONS FOR WINDS TO INCREASE TO AT LEAST 15 TO 25 KNOTS. THE PASSAGE OF THE COLD FRONT LATE THU NIGHT AND FRI MORNING WILL TURN THE WINDS TO THE WEST AND AS COLDER AIR MOVES IN CAN SEE WINDS AROUND 30 KNOTS SO WILL INCREASE THE FORECAST. HIGH PRESSURE SLOWLY PUSHES INTO OH TO GRADUALLY DIMINISH THE WINDS FRI NIGHT THRU SAT SO THE SCA WILL END. NOT SURE IF THE ICE IS BROKEN UP ENOUGH OR NOT BUT THIS MAY BE THE EVENT WHERE THE ICE TYPICALLY GETS PUSHED INTO THE EAST END OF THE LAKE WITH THE STRONGER SW TO W WINDS. THE HIGH WILL SHIFT OFF THE MID ATLANTIC COAST BY SUN NIGHT TO ALLOW LIGHT WINDS TO TURN SE AND START TO INCREASE SOME. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR LEZ142>146. && $$ SYNOPSIS...GARNET NEAR TERM...GARNET SHORT TERM...GARNET LONG TERM...ADAMS AVIATION...ADAMS MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
300 AM EDT WED APR 8 2015 .SYNOPSIS... A QUASI-STATIONARY FRONT WILL REMAIN OVER NORTHERN OHIO AND NORTHWEST PENNSYLVANIA TODAY THROUGH THURSDAY. A COLD FRONT WILL MOVE THROUGH THE REGION LATE THURSDAY NIGHT INTO FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE STATIONARY FRONTAL BOUNDARY WILL REMAIN OVER NORTHERN OHIO AND NORTHWEST PA TODAY. LITTLE MOVEMENT IS EXPECTED WITH THE FRONT WHICH IS TYPICAL FOR THIS TIME OF YEAR AS THESE TYPE OF STATIONARY FRONTS SET UP ON THE SOUTH SHORE OF LAKE ERIE. SHOWERS ARE EXPECTED NEAR THE FRONTAL BOUNDARY TODAY BUT I DO NOT EXPECT WIDE SPREAD AREAL COVERAGE. IT WILL BE TOUGH TO PREDICT THE TIMING. LOCALIZED BOUNDARIES AND DAYTIME HEATING WILL MOST LIKELY TRIGGER THE SHOWERS. THIS IS RE-ENFORCED BY THE HRRR MODEL AS SEVERAL RUNS INDICATED SCATTERED/ISOLATED SHOWER PATTERN OVER THE REGION THROUGH THE DAY. I WILL KEEP HIGH CHANCE TO LOW LIKELY RANGED POPS OVER THE AREA. THUNDER IS POSSIBLE AND THE THREAT WILL INCREASE THIS AFTERNOON. THE STORM PREDICTION CENTER HAS PLACED SOME OF THE NORTHWEST AND NORTH CENTRAL OHIO IN A SLIGHT RISK CATEGORY FOR SEVERE THUNDERSTORMS TODAY. BIG TEMPERATURE GRADIENT AGAIN NORTH TO SOUTH ACROSS THE AREA. NORTHEAST FLOW NEAR THE LAKE WILL KEEP TEMPERATURES MUCH COOLER && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... THE STATIONARY FRONTAL BOUNDARY WILL REMAIN OVER THE FORECAST AREA WEDNESDAY NIGHT INTO THURSDAY. WITH THE LACK OF STRONG DYNAMICS EARLY IN THE PERIOD...THE SHOWERS WILL ONCE AGAIN BE DIFFICULT TO TIME. SHOWERS AND A FEW THUNDERSTORMS WILL REMAIN OVER THE AREA BUT IT WILL BE FAIRLY UNORGANIZED. AS THE SHORT WAVE IN ADVANCE OF THE COLD FRONT BEGINS TO MOVE TOWARDS THE AREA THURSDAY...THE STATIONARY FRONT WILL MOVE NORTHWARD AS A WARM FRONT AND THE UPPER LEVEL SUPPORT WILL BECOME MORE FOCUSED. A LARGE AREA OF Q-VECTOR CONVERGENCE IS NOTED THURSDAY NIGHT WITH THE UPPER LEVEL SYSTEM. THE SHOWER AND THUNDERSTORM ACTIVITY SHOULD BE MUCH MORE NUMEROUS AND ORGANIZED ON THURSDAY NIGHT AND SEVERE WEATHER THREAT IS STILL A QUESTION. THE TIMING IS NOT OPTIMAL AS THE BEST LIFT WILL OCCUR DURING THE OVERNIGHT HOURS. WE WILL STILL CONTINUE TO MONITOR THE THREAT. AT THIS TIME MOST OF THE FORECAST AREA HAS A MARGINAL RISK FOR SEVERE THUNDERSTORMS THURSDAY NIGHT. THE COLD FRONT WILL SWEEP ACROSS THE REGION ON FRIDAY. A FEW SHOWERS AND A POSSIBLE THUNDERSTORM MAY LINGER OVER THE EASTERN SECTIONS OF THE AREA FRIDAY MORNING BUT SHOWER ACTIVITY SHOULD RAPIDLY DECREASE IN THE AFTERNOON. DRY AIR AND COLD ADVECTION WILL OCCUR FRIDAY NIGHT. 850MB TEMPS AS LOW AS -8C COULD MOVE OVER THE LAKE FRIDAY NIGHT INTO EARLY SATURDAY. A FEW WET SNOW FLAKES ARE NOT OUT OF THE QUESTION FOR NE OH AND NW PA BUT I WILL LEAVE THE MENTION OF SNOW OUT OF THE FORECAST AT THIS TIME. THE AIR IS VERY DRY BEHIND THE FRONT AND IT MAY BE DIFFICULT TO GET ANY TYPE OF PRECIPITATION WITHOUT ASSISTANCE FROM THE LAKE. HIGH PRESSURE WILL BUILD OVER THE REGION LATE SATURDAY THROUGH SATURDAY NIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... HIGH PRESSURE OVER THE AREA SHOULD PROVIDE DRY CONDITIONS ON SUN AND ALLOW TEMPS TO MODERATE BACK A FEW DEGREES ABOVE NORMAL. THE DRY CONDITIONS WILL QUICKLY CHANGE GOING INTO SUN NIGHT AS RETURN FLOW MOISTURE ARRIVES ALONG WITH A WEAK COLD FRONT FROM THE WEST. WILL GENERALLY LEAVE SUN NIGHT FORECAST AS IS BUT ALLOW FOR A MORE UNIFORM PRECIP THREAT ON MON. MODELS TRYING TO SHOW A REPEAT SETUP OF THE CURRENT PATTERN WITH A FRONT STALLED NEAR THE AREA STARTING BY TUE AND LASTING ALL WEEK SO WILL INCREASE POPS A LITTLE MORE. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... FRONT IN CENTRAL OH WILL DRIFT SLOWLY NORTH TO BE NEAR LAKE ERIE BY MIDNIGHT. LITTLE WILL CHANGE INTO DAYLIGHT SO IFR SHOULD PREVAIL WITH SCT SHRA. GUIDANCE INDICATES IMPROVEMENT TO MVFR/LOW VFR LATE MORNING INTO MIDDAY. BETTER THREAT FOR TSRA THIS AFTERNOON AND EARLY TONIGHT AS AIRMASS BECOMES MORE UNSTABLE...BUT WHERE AND WHEN TSRA MAY OCCUR IS ANYBODY`S GUESS SO FOR NOW WILL KEEP OUT OF TAFS OTHER THAN MENTION WITH VCTS. CONDITIONS SHOULD START TO LOWER AGAIN BY LATE EVENING AS LOW LEVELS COOL A FEW DEGREES. .OUTLOOK...NON VFR AT TIMES INTO FRIDAY...POSSIBLY CONTINUING IN NW PA EARLY SATURDAY. && .MARINE... WILL LEAVE SCA FOR WEST PART OF THE LAKE GOING UNTIL 3 PM BUT COULD BE TAKEN DOWN SOONER IF FRONT LIFTS INTO NEARSHORE WATERS A LITTLE BEFORE THEN AND TURNS WINDS MORE SOUTH AT A DIMINISHED SPEED. MODELS INDICATE THE FRONT MAY SAG BACK SOUTH OF THE LAKE TOWARD EVENING...POSSIBLY DUE TO LAKE BREEZE ENHANCEMENT BUT THEN SHOULD START TO LIFT BACK INTO THE LAKE LATER IN THE NIGHT AND CONTINUE OFF TO THE NORTH ON THU. THE WARM AIR FLOWING OVER THE COLD LAKE SHOULD PROVIDE A STABILIZING EFFECT SO WILL CONTINUE TO KEEP WINDS UNDER 20 KTS UNTIL THU NIGHT WHEN LOW LEVEL FLOW INCREASES MORE AND STARTS TO TURN SW. THIS WILL PROVIDE MORE FAVORABLE CONDITIONS FOR WINDS TO INCREASE TO AT LEAST 15 TO 25 KNOTS. THE PASSAGE OF THE COLD FRONT LATE THU NIGHT AND FRI MORNING WILL TURN THE WINDS TO THE WEST AND AS COLDER AIR MOVES IN CAN SEE WINDS AROUND 30 KNOTS SO WILL INCREASE THE FORECAST. HIGH PRESSURE SLOWLY PUSHES INTO OH TO GRADUALLY DIMINISH THE WINDS FRI NIGHT THRU SAT SO THE SCA WILL END. NOT SURE IF THE ICE IS BROKEN UP ENOUGH OR NOT BUT THIS MAY BE THE EVENT WHERE THE ICE TYPICALLY GETS PUSHED INTO THE EAST END OF THE LAKE WITH THE STRONGER SW TO W WINDS. THE HIGH WILL SHIFT OFF THE MID ATLANTIC COAST BY SUN NIGHT TO ALLOW LIGHT WINDS TO TURN SE AND START TO INCREASE SOME. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR LEZ142>146. && $$ SYNOPSIS...GARNET NEAR TERM...GARNET SHORT TERM...GARNET LONG TERM...ADAMS AVIATION...ADAMS MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS NORMAN OK
1213 PM CDT WED APR 8 2015 .AVIATION... 18Z TAFS...A COMPLEX OF HIGH BASED THUNDERSTORMS WILL MOVE ACROSS SOUTHWESTERN AND SOUTHERN OKLAHOMA...AND WESTERN NORTH TEXAS...AND MAY AFFECT KOUN/KOKC IN THE 18Z TO 20Z TIMEFRAME. THEREAFTER...A SECOND ROUND OF MORE ISOLATED TSRA IS EXPECTED TO DEVELOP OVER MAINLY NORTHERN AND WESTERN OKLAHOMA...AND TREK EASTWARD. WILL INTRODUCE TEMPO GROUPS AND VCTS...AS CONFIDENCE REMAINS RELATIVELY LOW ON TIMING AND IMPACTS TO ANY SINGLE TERMINAL. KPNC...ACROSS NORTH CENTRAL OKLAHOMA...PROBABLY HAS THE BETTER CHANCE OF SEEING TSRA IN THE 21Z THROUGH 00Z TIMEFRAME. SHRA/TSRA MAY LINGER BEYOND 00Z...WITH DECREASING INTENSITY. MVFR/IFR CIGS THEN LOOK TO DEVELOP AHEAD OF AN APPROACHING FRONT...WHICH WILL RESULT IN A NORTHWESTERLY WIND SHIFT FROM 09Z THROUGH 18Z THURS. && .PREV DISCUSSION... /ISSUED 1126 AM CDT WED APR 8 2015/ DISCUSSION... UPDATED POPS FOR LATE THIS MORNING/EARLY AFTERNOON TO ACCOUNT FOR ELEVATED CONVECTION. SHOWERS AND A FEW STORMS SHOULD REACH CENTRAL OKLAHOMA BETWEEN 1230-130 PM. STILL EXPECT SEVERE STORMS WILL DEVELOP IN WESTERN AND NORTHERN OKLAHOMA...MAINLY AFTER 3-4 PM. A LITTLE UNSURE ABOUT RED FLAG WARNING IN FAR WESTERN OKLAHOMA BUT DRY AIR SHOULD REACH AREAS WEST OF BUFFALO...WOODWARD AND ELK CITY BY MID TO LATE AFTERNOON. PREV DISCUSSION... /ISSUED 648 AM CDT WED APR 8 2015/ DISCUSSION... THE 12Z AVIATION DISCUSSION FOLLOWS.... AVIATION... A STATIONARY FRONT VERY NEAR THE OK/KS BORDER MAY SAG A LITTLE FARTHER S THIS MORNING...BEFORE MOVING N AS A WARM FRONT LATER TODAY. IF IT MOVES S OF KGAG/KWWR/KPNC EARLY THIS MORNING...LOW CLOUDS AND BR/FG COULD MOVE INTO THOSE SITES...BUT SHOULD BE SHORT-LIVED. TSRA MAY FORM THIS MORNING...MOST LIKELY ALONG I-44...AND ARE EXPECTED TO BE ELEVATED IN NATURE...SO NOT LIKELY SEVERE. MUCH MORE ROBUST TSRA...POSSIBLY WITH SEVERE WEATHER...OUTFLOW...AND OTHER TYPICAL AVIATION HAZARDS...WILL DEVELOP AROUND MID-AFTERNOON THROUGH THIS EVENING IF THE LOW-LEVEL INVERSION CAN BE OVERCOME. THIS IS MOST LIKELY TO HAPPEN AT KPNC...BUT IS ALSO POSSIBLE AT ALL OTHER TAF SITES. TSRA SHOULD BECOME MORE NUMEROUS...BUT LESS SEVERE...OVERNIGHT AS THE DRYLINE AND A COLD FRONT BEGIN TO ADVANCE E. LOW CEILINGS ARE LIKELY TOMORROW MORNING IN ADVANCE OF THE DRYLINE/FRONT COMBINATION. CMS PREV DISCUSSION... /ISSUED 424 AM CDT WED APR 8 2015/ DISCUSSION... AN APPROACHING UPPER-LEVEL WAVE MAY GENERATE A FEW SHOWERS/THUNDERSTORMS THIS MORNING OR EARLY AFTERNOON OVER NORTH TEXAS AND OKLAHOMA. THESE SHOWERS/STORMS WOULD BE ELEVATED...AND WOULD POSE LITTLE OR NO RISK OF PRODUCING SEVERE WEATHER. THE RISK OF SEVERE WEATHER LATER THIS AFTERNOON AND THIS EVENING CONTINUES TO BE PROBLEMATIC...AS A RATHER STRONG CAPPING INVERSION WILL REDUCE THE ABILITY OF STORMS TO DEVELOP IN AN OTHERWISE FAVORABLE ENVIRONMENT FOR SEVERE WEATHER. WE CONTINUE WITH RELATIVELY LOW PROBABILITIES OF RAIN...BUT IT IS STILL THE CASE THAT ANY STORM OR STORMS THAT DO FORM WILL HAVE PLENTY OF INSTABILITY AND SHEAR TO WORK WITH. THE PRESENCE OF A DRYLINE AND STATIONARY FRONT WILL LIKELY OVERCOME THE CAP...AT LEAST NEAR THE KANSAS BORDER...THIS AFTERNOON. THAT CONVECTION WILL LIKELY GENERATE NEW CONVECTION AS OUTFLOW BOUNDARIES PROVIDE SUFFICIENT LOW-LEVEL CONVERGENCE TO OVERCOME THE WEAKER PARTS OF THE CAP. STORMS THAT DEVELOP WILL LIKELY PERSIST INTO THE NIGHT. STORMS WILL CONTINUE OFF AND ON INTO TOMORROW AFTERNOON...AND AN APPARENTLY SLOWER MOVEMENT OF THE COLD FRONT WILL KEEP RAIN CHANCES IN OUR SOUTHEAST COUNTIES THROUGH EARLY FRIDAY. IN ADDITION TO THE SLOWNESS...IT APPEARS THAT THE FRONT WILL NOT GO VERY FAR SOUTH...AND RETURN MOISTURE WILL BRING RAIN CHANCES BACK INTO OUR SOUTHERN COUNTIES FRIDAY EVENING...ELIMINATING THE ONLY DAY THAT HAD BEEN FORECAST TO BE COMPLETELY RAIN-FREE BETWEEN NOW AND THE EARLY PART OF NEXT WEEK. SHOWERS AND STORMS WILL PROBABLY BECOME FAIRLY NUMEROUS OVER THE WEEKEND...THEN DIMINISH SLOWLY IN PROBABILITY INTO EARLY NEXT WEEK. ALSO PROBLEMATIC TODAY IS THE WILDFIRE POTENTIAL FOR THIS AFTERNOON AND THIS EVENING. ALL MODELS SHOW THE DRYLINE FARTHER WEST THAN BEFORE...AND NONE OF THEM SUPPORT A RED FLAG WARNING OUTSIDE THE NEW WARNING AREA...GENERALLY WEST OF A LINE FROM WOODWARD TO SAYRE. THE HRRR DOES SHOW THE DRYLINE FARTHER EAST THAN THIS...BUT DOES NOT HAVE SUFFICIENT WIND SPEEDS OUTSIDE THIS AREA. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 63 78 49 72 / 40 10 10 10 HOBART OK 61 78 46 73 / 20 10 10 10 WICHITA FALLS TX 66 84 51 74 / 30 10 10 10 GAGE OK 53 71 39 75 / 10 0 0 0 PONCA CITY OK 60 74 44 72 / 40 10 10 0 DURANT OK 66 77 53 73 / 30 30 40 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR OKZ004-009-010- 014-021. TX...NONE. && $$ 06/84
AREA FORECAST DISCUSSION
NWS NORMAN OK
1126 AM CDT WED APR 8 2015 .DISCUSSION... UPDATED POPS FOR LATE THIS MORNING/EARLY AFTERNOON TO ACCOUNT FOR ELEVATED CONVECTION. SHOWERS AND A FEW STORMS SHOULD REACH CENTRAL OKLAHOMA BETWEEN 1230-130 PM. STILL EXPECT SEVERE STORMS WILL DEVELOP IN WESTERN AND NORTHERN OKLAHOMA...MAINLY AFTER 3-4 PM. A LITTLE UNSURE ABOUT RED FLAG WARNING IN FAR WESTERN OKLAHOMA BUT DRY AIR SHOULD REACH AREAS WEST OF BUFFALO...WOODWARD AND ELK CITY BY MID TO LATE AFTERNOON. && .PREV DISCUSSION... /ISSUED 648 AM CDT WED APR 8 2015/ DISCUSSION... THE 12Z AVIATION DISCUSSION FOLLOWS.... AVIATION... A STATIONARY FRONT VERY NEAR THE OK/KS BORDER MAY SAG A LITTLE FARTHER S THIS MORNING...BEFORE MOVING N AS A WARM FRONT LATER TODAY. IF IT MOVES S OF KGAG/KWWR/KPNC EARLY THIS MORNING...LOW CLOUDS AND BR/FG COULD MOVE INTO THOSE SITES...BUT SHOULD BE SHORT-LIVED. TSRA MAY FORM THIS MORNING...MOST LIKELY ALONG I-44...AND ARE EXPECTED TO BE ELEVATED IN NATURE...SO NOT LIKELY SEVERE. MUCH MORE ROBUST TSRA...POSSIBLY WITH SEVERE WEATHER...OUTFLOW...AND OTHER TYPICAL AVIATION HAZARDS...WILL DEVELOP AROUND MID-AFTERNOON THROUGH THIS EVENING IF THE LOW-LEVEL INVERSION CAN BE OVERCOME. THIS IS MOST LIKELY TO HAPPEN AT KPNC...BUT IS ALSO POSSIBLE AT ALL OTHER TAF SITES. TSRA SHOULD BECOME MORE NUMEROUS...BUT LESS SEVERE...OVERNIGHT AS THE DRYLINE AND A COLD FRONT BEGIN TO ADVANCE E. LOW CEILINGS ARE LIKELY TOMORROW MORNING IN ADVANCE OF THE DRYLINE/FRONT COMBINATION. CMS PREV DISCUSSION... /ISSUED 424 AM CDT WED APR 8 2015/ DISCUSSION... AN APPROACHING UPPER-LEVEL WAVE MAY GENERATE A FEW SHOWERS/THUNDERSTORMS THIS MORNING OR EARLY AFTERNOON OVER NORTH TEXAS AND OKLAHOMA. THESE SHOWERS/STORMS WOULD BE ELEVATED...AND WOULD POSE LITTLE OR NO RISK OF PRODUCING SEVERE WEATHER. THE RISK OF SEVERE WEATHER LATER THIS AFTERNOON AND THIS EVENING CONTINUES TO BE PROBLEMATIC...AS A RATHER STRONG CAPPING INVERSION WILL REDUCE THE ABILITY OF STORMS TO DEVELOP IN AN OTHERWISE FAVORABLE ENVIRONMENT FOR SEVERE WEATHER. WE CONTINUE WITH RELATIVELY LOW PROBABILITIES OF RAIN...BUT IT IS STILL THE CASE THAT ANY STORM OR STORMS THAT DO FORM WILL HAVE PLENTY OF INSTABILITY AND SHEAR TO WORK WITH. THE PRESENCE OF A DRYLINE AND STATIONARY FRONT WILL LIKELY OVERCOME THE CAP...AT LEAST NEAR THE KANSAS BORDER...THIS AFTERNOON. THAT CONVECTION WILL LIKELY GENERATE NEW CONVECTION AS OUTFLOW BOUNDARIES PROVIDE SUFFICIENT LOW-LEVEL CONVERGENCE TO OVERCOME THE WEAKER PARTS OF THE CAP. STORMS THAT DEVELOP WILL LIKELY PERSIST INTO THE NIGHT. STORMS WILL CONTINUE OFF AND ON INTO TOMORROW AFTERNOON...AND AN APPARENTLY SLOWER MOVEMENT OF THE COLD FRONT WILL KEEP RAIN CHANCES IN OUR SOUTHEAST COUNTIES THROUGH EARLY FRIDAY. IN ADDITION TO THE SLOWNESS...IT APPEARS THAT THE FRONT WILL NOT GO VERY FAR SOUTH...AND RETURN MOISTURE WILL BRING RAIN CHANCES BACK INTO OUR SOUTHERN COUNTIES FRIDAY EVENING...ELIMINATING THE ONLY DAY THAT HAD BEEN FORECAST TO BE COMPLETELY RAIN-FREE BETWEEN NOW AND THE EARLY PART OF NEXT WEEK. SHOWERS AND STORMS WILL PROBABLY BECOME FAIRLY NUMEROUS OVER THE WEEKEND...THEN DIMINISH SLOWLY IN PROBABILITY INTO EARLY NEXT WEEK. ALSO PROBLEMATIC TODAY IS THE WILDFIRE POTENTIAL FOR THIS AFTERNOON AND THIS EVENING. ALL MODELS SHOW THE DRYLINE FARTHER WEST THAN BEFORE...AND NONE OF THEM SUPPORT A RED FLAG WARNING OUTSIDE THE NEW WARNING AREA...GENERALLY WEST OF A LINE FROM WOODWARD TO SAYRE. THE HRRR DOES SHOW THE DRYLINE FARTHER EAST THAN THIS...BUT DOES NOT HAVE SUFFICIENT WIND SPEEDS OUTSIDE THIS AREA. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 81 63 78 49 / 40 40 10 10 HOBART OK 85 61 78 46 / 30 20 10 10 WICHITA FALLS TX 81 66 84 51 / 30 30 10 10 GAGE OK 87 53 71 39 / 10 10 0 0 PONCA CITY OK 84 60 74 44 / 40 40 10 10 DURANT OK 79 66 77 53 / 20 30 30 40 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR OKZ004-009-010- 014-021. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS NORMAN OK
648 AM CDT WED APR 8 2015 .DISCUSSION... THE 12Z AVIATION DISCUSSION FOLLOWS.... && .AVIATION... A STATIONARY FRONT VERY NEAR THE OK/KS BORDER MAY SAG A LITTLE FARTHER S THIS MORNING...BEFORE MOVING N AS A WARM FRONT LATER TODAY. IF IT MOVES S OF KGAG/KWWR/KPNC EARLY THIS MORNING...LOW CLOUDS AND BR/FG COULD MOVE INTO THOSE SITES...BUT SHOULD BE SHORT-LIVED. TSRA MAY FORM THIS MORNING...MOST LIKELY ALONG I-44...AND ARE EXPECTED TO BE ELEVATED IN NATURE...SO NOT LIKELY SEVERE. MUCH MORE ROBUST TSRA...POSSIBLY WITH SEVERE WEATHER...OUTFLOW...AND OTHER TYPICAL AVIATION HAZARDS...WILL DEVELOP AROUND MID-AFTERNOON THROUGH THIS EVENING IF THE LOW-LEVEL INVERSION CAN BE OVERCOME. THIS IS MOST LIKELY TO HAPPEN AT KPNC...BUT IS ALSO POSSIBLE AT ALL OTHER TAF SITES. TSRA SHOULD BECOME MORE NUMEROUS...BUT LESS SEVERE...OVERNIGHT AS THE DRYLINE AND A COLD FRONT BEGIN TO ADVANCE E. LOW CEILINGS ARE LIKELY TOMORROW MORNING IN ADVANCE OF THE DRYLINE/FRONT COMBINATION. CMS && .PREV DISCUSSION... /ISSUED 424 AM CDT WED APR 8 2015/ DISCUSSION... AN APPROACHING UPPER-LEVEL WAVE MAY GENERATE A FEW SHOWERS/THUNDERSTORMS THIS MORNING OR EARLY AFTERNOON OVER NORTH TEXAS AND OKLAHOMA. THESE SHOWERS/STORMS WOULD BE ELEVATED...AND WOULD POSE LITTLE OR NO RISK OF PRODUCING SEVERE WEATHER. THE RISK OF SEVERE WEATHER LATER THIS AFTERNOON AND THIS EVENING CONTINUES TO BE PROBLEMATIC...AS A RATHER STRONG CAPPING INVERSION WILL REDUCE THE ABILITY OF STORMS TO DEVELOP IN AN OTHERWISE FAVORABLE ENVIRONMENT FOR SEVERE WEATHER. WE CONTINUE WITH RELATIVELY LOW PROBABILITIES OF RAIN...BUT IT IS STILL THE CASE THAT ANY STORM OR STORMS THAT DO FORM WILL HAVE PLENTY OF INSTABILITY AND SHEAR TO WORK WITH. THE PRESENCE OF A DRYLINE AND STATIONARY FRONT WILL LIKELY OVERCOME THE CAP...AT LEAST NEAR THE KANSAS BORDER...THIS AFTERNOON. THAT CONVECTION WILL LIKELY GENERATE NEW CONVECTION AS OUTFLOW BOUNDARIES PROVIDE SUFFICIENT LOW-LEVEL CONVERGENCE TO OVERCOME THE WEAKER PARTS OF THE CAP. STORMS THAT DEVELOP WILL LIKELY PERSIST INTO THE NIGHT. STORMS WILL CONTINUE OFF AND ON INTO TOMORROW AFTERNOON...AND AN APPARENTLY SLOWER MOVEMENT OF THE COLD FRONT WILL KEEP RAIN CHANCES IN OUR SOUTHEAST COUNTIES THROUGH EARLY FRIDAY. IN ADDITION TO THE SLOWNESS...IT APPEARS THAT THE FRONT WILL NOT GO VERY FAR SOUTH...AND RETURN MOISTURE WILL BRING RAIN CHANCES BACK INTO OUR SOUTHERN COUNTIES FRIDAY EVENING...ELIMINATING THE ONLY DAY THAT HAD BEEN FORECAST TO BE COMPLETELY RAIN-FREE BETWEEN NOW AND THE EARLY PART OF NEXT WEEK. SHOWERS AND STORMS WILL PROBABLY BECOME FAIRLY NUMEROUS OVER THE WEEKEND...THEN DIMINISH SLOWLY IN PROBABILITY INTO EARLY NEXT WEEK. ALSO PROBLEMATIC TODAY IS THE WILDFIRE POTENTIAL FOR THIS AFTERNOON AND THIS EVENING. ALL MODELS SHOW THE DRYLINE FARTHER WEST THAN BEFORE...AND NONE OF THEM SUPPORT A RED FLAG WARNING OUTSIDE THE NEW WARNING AREA...GENERALLY WEST OF A LINE FROM WOODWARD TO SAYRE. THE HRRR DOES SHOW THE DRYLINE FARTHER EAST THAN THIS...BUT DOES NOT HAVE SUFFICIENT WIND SPEEDS OUTSIDE THIS AREA. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 82 63 78 49 / 20 30 10 10 HOBART OK 87 61 78 46 / 20 20 10 10 WICHITA FALLS TX 85 66 84 51 / 20 30 10 10 GAGE OK 92 53 71 39 / 10 10 0 0 PONCA CITY OK 81 60 74 44 / 40 30 10 10 DURANT OK 80 66 77 53 / 20 30 30 40 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING FOR OKZ004-009-010-014-021. TX...NONE. && $$ 09/23/23
AREA FORECAST DISCUSSION
NWS NORMAN OK
424 AM CDT WED APR 8 2015 .DISCUSSION... AN APPROACHING UPPER-LEVEL WAVE MAY GENERATE A FEW SHOWERS/THUNDERSTORMS THIS MORNING OR EARLY AFTERNOON OVER NORTH TEXAS AND OKLAHOMA. THESE SHOWERS/STORMS WOULD BE ELEVATED...AND WOULD POSE LITTLE OR NO RISK OF PRODUCING SEVERE WEATHER. THE RISK OF SEVERE WEATHER LATER THIS AFTERNOON AND THIS EVENING CONTINUES TO BE PROBLEMATIC...AS A RATHER STRONG CAPPING INVERSION WILL REDUCE THE ABILITY OF STORMS TO DEVELOP IN AN OTHERWISE FAVORABLE ENVIRONMENT FOR SEVERE WEATHER. WE CONTINUE WITH RELATIVELY LOW PROBABILITIES OF RAIN...BUT IT IS STILL THE CASE THAT ANY STORM OR STORMS THAT DO FORM WILL HAVE PLENTY OF INSTABILITY AND SHEAR TO WORK WITH. THE PRESENCE OF A DRYLINE AND STATIONARY FRONT WILL LIKELY OVERCOME THE CAP...AT LEAST NEAR THE KANSAS BORDER...THIS AFTERNOON. THAT CONVECTION WILL LIKELY GENERATE NEW CONVECTION AS OUTFLOW BOUNDARIES PROVIDE SUFFICIENT LOW-LEVEL CONVERGENCE TO OVERCOME THE WEAKER PARTS OF THE CAP. STORMS THAT DEVELOP WILL LIKELY PERSIST INTO THE NIGHT. STORMS WILL CONTINUE OFF AND ON INTO TOMORROW AFTERNOON...AND AN APPARENTLY SLOWER MOVEMENT OF THE COLD FRONT WILL KEEP RAIN CHANCES IN OUR SOUTHEAST COUNTIES THROUGH EARLY FRIDAY. IN ADDITION TO THE SLOWNESS...IT APPEARS THAT THE FRONT WILL NOT GO VERY FAR SOUTH...AND RETURN MOISTURE WILL BRING RAIN CHANCES BACK INTO OUR SOUTHERN COUNTIES FRIDAY EVENING...ELIMINATING THE ONLY DAY THAT HAD BEEN FORECAST TO BE COMPLETELY RAIN-FREE BETWEEN NOW AND THE EARLY PART OF NEXT WEEK. SHOWERS AND STORMS WILL PROBABLY BECOME FAIRLY NUMEROUS OVER THE WEEKEND...THEN DIMINISH SLOWLY IN PROBABILITY INTO EARLY NEXT WEEK. ALSO PROBLEMATIC TODAY IS THE WILDFIRE POTENTIAL FOR THIS AFTERNOON AND THIS EVENING. ALL MODELS SHOW THE DRYLINE FARTHER WEST THAN BEFORE...AND NONE OF THEM SUPPORT A RED FLAG WARNING OUTSIDE THE NEW WARNING AREA...GENERALLY WEST OF A LINE FROM WOODWARD TO SAYRE. THE HRRR DOES SHOW THE DRYLINE FARTHER EAST THAN THIS...BUT DOES NOT HAVE SUFFICIENT WIND SPEEDS OUTSIDE THIS AREA. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 82 63 78 49 / 20 30 10 10 HOBART OK 87 61 78 46 / 20 20 10 10 WICHITA FALLS TX 85 66 84 51 / 20 30 10 10 GAGE OK 92 53 71 39 / 10 10 0 0 PONCA CITY OK 81 60 74 44 / 40 30 10 10 DURANT OK 80 66 77 53 / 20 30 30 40 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING FOR OKZ004-009-010-014-021. TX...NONE. && $$ 09/23
AREA FORECAST DISCUSSION
NWS TULSA OK
1149 PM CDT TUE APR 7 2015 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. RATHER STRONG SOUTHERLY WINDS WILL PREVAIL THROUGH THE FORECAST PERIOD. MVFR CEILINGS WILL DEVELOP AROUND SUNRISE AT ALL SITES WITH SOME IMPROVEMENT EXPECTED BY AFTERNOON. WIDELY SCATTERED THUNDERSTORMS WILL BE POSSIBLE WEDNESDAY AFTERNOON AND EVENING BUT THE EXPECTED COVERAGE IS TOO LOW TO INCLUDE IN THE TAFS AT THIS TIME. && .PREV DISCUSSION... /ISSUED 935 PM CDT TUE APR 7 2015/ ..UPDATE... DISCUSSION... A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 2 AM FOR THE NORTHERN TIER OF COUNTIES IN NORTHEAST OKLAHOMA. RAISED POPS IN THAT AREA EARLIER THIS EVENING BUT SO FAR HAVE HAD NO CONVECTIVE DEVELOPMENT SOUTH OF THE KANSAS BORDER. STORMS WILL REMAIN POSSIBLE OVERNIGHT IN THIS AREA. NO OTHER SIGNIFICANT CHANGES TO THE AFTERNOON FORECAST HAVE BEEN MADE THIS EVENING. PREV DISCUSSION... /ISSUED 608 PM CDT TUE APR 7 2015/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. FOR THE 0Z TAFS... VFR CONDITIONS WILL PREVAIL INTO THIS EVENING AT ALL TAF SITES WITH FAIRLY STRONG SOUTHERLY WINDS CONTINUING. MVFR CEILINGS ARE EXPECTED TO DEVELOP AREAWIDE BEFORE MIDNIGHT. THUNDERSTORMS MAY AFFECT NORTHEAST OKLAHOMA SITES THIS EVENING BUT CHANCES ARE LOW. MORE WIDESPREAD... POSSIBLE STRONG THUNDERSTORMS WILL AFFECT ALL SITES BEGINNING WEDNESDAY AFTERNOON. PREV DISCUSSION... /ISSUED 322 PM CDT TUE APR 7 2015/ DISCUSSION... A WEAK FRONTAL BOUNDARY EXTENDS FROM WEST OF KANSAS CITY INTO NW OKLAHOMA THIS AFTERNOON WITH A VERY UNSTABLE BUT STRONGLY CAPPED AIRMASS RESIDING OVER EASTERN OK AND NORTHWEST AR. TEMPS ALONG AND SE OF THE FRONT HAVE WARMED INTO THE MID 80S TO NEAR 90...AND ALSO A SUBTLE OUTFLOW BOUNDARY FROM EARLIER STORMS PUSHING THROUGH SW MISSOURI AT THIS TIME. NO SIGNIFICANT UPPER AIR FORCING AT THIS POINT...BUT ISOLATED STORMS STILL MAY DEVELOP NEAR THE SFC FRONT AND OUTFLOW BOUNDARY LATER THIS AFTERNOON OR EARLY THIS EVENING AS HRRR AND TO A LESSER EXTENT OUR LOCALLY RUN 5KM WRF CONTINUE TO INDICATE. GIVEN THE AMOUNT OF AVAILABLE CAPE AND AT LEAST MODERATE SHEAR ANY STORMS COULD BECOME SEVERE SHOULD UPDRAFTS BE SUSTAINED... LARGE HAIL AND WINDS THE MAIN THREATS. CAP WILL REMAIN WITH US FOR THE MOST PART THROUGH TONIGHT WITH ONLY A LIMITED CHANCE OF STORMS NEAR KANSAS AND MISSOURI BORDERS. UNSTABLE AND CAPPED ENVIRONMENT REMAINS WITH US WEDNESDAY... HOWEVER WITH UPPER LOW CURRENTLY OFF THE CALIFORNIA COAST MOVING INTO THE CENTRAL ROCKIES DURING THE DAY...MID LEVEL HEIGHT FALLS AND A POTENTIAL LEAD SHORT WAVE/ JET STREAK SHOULD HELP ERODE THE CAP ENOUGH FOR SOME STORMS TO DEVELOP ALONG THE DRY LINE FROM CENTRAL KS INTO NORTHERN OK. MOST LIKELY TIME WOULD BE 21-00Z HOWEVER EARLIER RUNS OF THE NAM HAVE SHOWN SOME EARLIER DEVELOPMENT THAN THAT. WIND PROFILES SUGGEST THAT ONCE A STORM DEVELOPS IT WILL QUICKLY BECOME SUPERCELLULAR AND POSE A THREAT FOR VERY LARGE GAIL AND DAMAGING WINDS...AND SOME DEGREE OF TORNADO POTENTIAL. OVERALL STORM COVERAGE IS EXPECTED TO REMAIN FAIRLY LIMITED THROUGH WED NIGHT DUE TO PERSISTENT CAP ISSUES. MAIN UPPER SYSTEM CONTINUES TO PROGRESS EAST THURSDAY WITH A COLD FRONT OVERTAKING THE DRY LINE AND LIKELY PUSHING THROUGH PARTS OF NE OKLAHOMA BY EARLY AFTERNOON. CONTINUED MOIST AND VERY UNSTABLE AHEAD OF THE FRONT WITH MORE WIDESPREAD THUNDERSTORMS LIKELY THU AFTERNOON AND EVENING MAINLY OVER SOUTHEAST OK AND NORTHWEST AR. SHEAR PROFILES SUGGEST A MORE LINEAR STORM MODE AT THIS TIME. STORMS WILL END THU EVENING WITH A COOLER AND STABLE AIRMASS SETTLING OVER THE AREA FRIDAY. ANOTHER UPPER LEVEL SYSTEM WILL MOVE IN FROM THE WEST BY THIS WEEKEND AND WITH THE PRESENCE OF A SFC BOUNDARY IN THE AREA... THUNDERSTORM CHANCES WILL RETURN BY SATURDAY AND CONTINUE INTO EARLY NEXT WEEK. GENERAL CONSENSUS IS THIS UPPER LOW WILL ULTIMATELY TACK A MUCH MORE SOUTHERLY TRACK...ANY SEVERE WEATHER THREATS DURING THIS TIME REMAIN EXTREMELY UNCERTAIN. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...05
AREA FORECAST DISCUSSION
NWS PENDLETON OR
1025 AM PDT WED APR 8 2015 UPDATED AVIATION DISCUSSION .UPDATE...TODAY AND TONIGHT...MOSTLY CLOUDY SKIES OVER MUCH OF THE AREA THIS MORNING...EXCEPT A FEW BREAKS OVER THE YAKIMA VALLEY EXTENDING DOWN INTO CENTRAL OREGON. CURRENT RADAR IS INDICATING A FEW SPRINKLES OR LIGHT SHOWERS OVER THE NORTHERN BLUE MOUNTAINS AND BLUE MOUNTAIN FOOTHILLS...ANYTHING THAT FALLS WILL BE VERY LIGHT THROUGH 18Z. BY 19-21Z LATEST HRRR AND OTHER SHORT TERM GUIDANCE IS INDICATING SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS DEVELOPING OVER MUCH OF THE CWA IN RESPONSE TO INCREASED INSTABILITY ASSOCIATED WITH THE UPPER LEVEL LOW CENTERED OVER NORTHERN NEVADA. THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS WILL LIKELY BE FROM ABOUT 21Z THIS AFTERNOON THROUGH 03Z THIS EVENING. AFTER 03Z THIS EVENING SHOWERS AND ANY LINGERING STORMS WILL QUICKLY DECREASE IN COVERAGE AS WE LOSE DAYTIME HEATING AND INSTABILITY. AFTER 06Z MOST AREAS WILL DRY OUT WITH THE ONLY EXCEPTION BEING OVER THE NORTHERN BLUE MOUNTAINS AND ESPECIALLY WALLOWA COUNTY WHERE THERE WILL BE A SLIGHT CHC TO LOW END CHC FOR RAIN AND HIGHER ELEVATION SNOW SHOWERS THROUGH THE OVERNIGHT. SNOW LEVELS WILL BE BETWEEN 4500 TO 5200 FEET THIS AFTERNOON LOWERING SLIGHTLY TO BETWEEN 4200 TO 4700 FEET OVERNIGHT. TEMPERATURES LOOKED FINE FOR TODAY AND TONIGHT WITH THE LOWER ELEVATIONS AND BASINS RANGING FROM THE UPPER 50S TO MID 60S THIS AFTERNOON AND THE MOUNTAINS IN THE 40S TO AROUND 50. OVERNIGHT LOWS WILL REMAIN ABOVE FREEZING TONIGHT IN THE LOWER ELEVATIONS...MAINLY IN THE MID TO UPPER 30S. THE MOUNTAINS AND HIGHER PLATEAUS...INCLUDING CENTRAL OREGON...WILL FALL INTO THE 20S OVERNIGHT. WINDS WILL INCREASE AN BECOME BREEZY OUT OF THE NORTHWEST AT 8 TO 16 MPH FOR MOST LOCATIONS THIS AFTERNOON...ONE OF THE WINDIER SPOTS WILL BE THE GRANDE RONDE VALLEY WHERE WINDS OF AROUND 20 MPH WITH GUSTS TO 30-35 MPH ARE EXPECTED THIS AFTERNOON. 77 .AVIATION...18Z TAFS...VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HOURS. A LOW OFF THE COAST WILL KEEP A BKN DECK OF CLOUDS GENERALLY BETWEEN 6000-8000 FEET OVER THE AREA THROUGH THIS AFTERNOON BUT LOCALLY LOWER AROUND KRDM AND KBDN. AFTERNOON CONVECTIVE SHOWERS AND PERHAPS A FEW ISOLATED THUNDERSTORMS ARE EXPECTED AFTER 21Z. NOT ENOUGH CONFIDENCE TO MENTION VCTS OR -TSRA IN THE TAFS. WINDS WILL GENERALLY REMAIN BELOW 15 KTS FOR THE NEXT 24 HOURS THOUGH KRDM, KBDN AND KDLS WILL HAVE GUSTS TO 20 KTS AFTER 21Z...SHOWERS EXPECTED TO DIMINISH AFTER 03-05Z THIS EVENING AT ALL TAF SITES. && .PREV DISC... /ISSUED 415 AM PDT WED APR 8 2015/ SHORT TERM...TODAY THROUGH THURSDAY NIGHT...AN UPPER TROUGH WILL REMAIN OVER THE REGION TODAY. A LOW CENTER AT THE BASE OF THE TROUGH WILL WEAKEN AND SLIDE EAST TO WYOMING TODAY. THIS LOW HAS BEEN SPREADING MOISTURE NORTH INTO CENTRAL AND NORTHEAST OREGON EARLY THIS MORNING. PRECIP ASSOCIATED WITH THIS WRAP AROUND MOISTURE HAS BEEN LIMITED THIS MORNING, MAINLY OVER CENTRAL OREGON. UPSLOPE AFFECTS HAVE BEEN CAUSING LOCALLY ENHANCED RAIN AND/OR SNOW SOUTH AND WEST OF BEND. THIS PRECIP SHOULD WIND DOWN TOWARDS DAYBREAK. BEFORE THEN, LOCAL SNOW AMOUNTS OF AN INCH OR TWO COULD ACCUMULATE OVER THESE UPSLOPE AREAS. LATE THIS MORNING THROUGH THIS EVENING, COLD AIR ALOFT COMBINED WITH DAYTIME HEATING SHOULD PRODUCE ENOUGH INSTABILITY FOR ISOLATED TO SCATTERED SHOWER OVER THE AREA. ALSO STRAY THUNDERSTORMS WILL BE POSSIBLE LATE AFTERNOON AND EARLY EVENING OVER MUCH OF THE ARE, THOUGH WESTERLY LOW LEVEL FLOW IS CURRENTLY EXPECTED TO INHIBIT STORM DEVELOPMENT FROM THE GORGE SOUTH TO CENTRAL OREGON. THE SHOWERS WILL DECREASE ACROSS THE AREA LATE THIS EVENING AND OVERNIGHT, WITH ONLY A FEW SHOWERS LINGERING OVER THE BLUES AND WALLOWA COUNTY. A WEAK PIECE OF ENERGY LOOKS TO DRIFT OVER THE REGION THURSDAY. THIS ENERGY IS EXPECTED TO CAUSE A FEW SHOWERS TO OCCUR OVER PORTIONS OF THE AREA, WITH THE POSSIBILITY OF A STRAY THUNDERSTORM OVER OUR NORTHEASTERN ZONES. THESE SHOWERS AND STORMS WILL DECREASE THROUGH THURSDAY EVENING, AND LARGELY END AFTER MIDNIGHT. 90 LONG TERM...FRIDAY THROUGH TUESDAY...FRIDAY AN UPPER LEVEL TROUGH WILL MOVE TOWARD WASHINGTON AND OREGON BRINGING WIND, RAIN AND MOUNTAIN SNOW FRIDAY NIGHT AND SATURDAY. BREEZY TO WINDY CONDITIONS WILL DEVELOP SATURDAY AS SURFACE PRESSURE GRADIENTS TIGHTEN BEHIND A COLD FRONT AND STRONGER WINDS ALOFT MIX TO THE SURFACE. SOME WIND ADVISORIES ARE POSSIBLE...PARTICULARLY IN THE LOWER COLUMBIA BASIN. STRONG COLD ADVECTION BEHIND THE FRONT WILL DROP SNOW LEVELS TO 2000-3000 FT BY SUNDAY MORNING. SATURDAY NIGHT AND SUNDAY WESTERLY FLOW WITH SOME EMBEDDED DISTURBANCES WILL BE OVER EASTERN WASHINGTON AND OREGON. THESE DISTURBANCES WILL KEEP SOME UPSLOPE SHOWERS OVER MOST OF THE AREA. AND TUESDAY MODELS DIVERGE SIGNIFICANTLY. ECMWF HAS A WEAK TROUGH DEVELOPING OVER WASHINGTON AND OREGON. GFS HAS A CLOSED LOW OVER THE EASTERN PACIFIC MONDAY THAT MOVES INLAND TUESDAY. GFS ENSEMBLES SHOW ENOUGH SPREAD TO COVER BOTH POSIBILITIES. THIS LOWERS CONFIDENCE IN ANY FORECAST TIMING AND STRENGTH MONDAY AND TUESDAY. GIVEN THE MODELS DIFFERENCES MADE FEW CHANGES TO CURRENT FORECAST OF A SLIGHT CHANCE OF RAIN SHOWERS IN THE LOWER ELEVATIONS AND A CHANCE OF RAIN AND SNOW IN THE MOUNTAINS SUNDAY NIGHT THROUGH TUESDAY. COONFIELD && .PRELIMINARY POINT TEMPS/POPS... PDT 60 37 63 38 / 30 30 10 20 ALW 62 42 64 42 / 30 30 20 20 PSC 65 38 67 37 / 20 30 10 10 YKM 62 37 64 35 / 30 20 10 10 HRI 64 37 67 34 / 30 30 10 10 ELN 62 36 65 33 / 30 20 10 10 RDM 54 24 61 28 / 40 20 10 10 LGD 55 33 57 34 / 40 40 20 30 GCD 56 32 62 33 / 50 40 20 20 DLS 63 40 68 40 / 20 20 10 10 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. && FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT... WWW.WEATHER.GOV/PENDLETON $$ 77/91/91
AREA FORECAST DISCUSSION
NWS PENDLETON OR
917 AM PDT WED APR 8 2015 .UPDATE...TODAY AND TONIGHT...MOSTLY CLOUDY SKIES OVER MUCH OF THE AREA THIS MORNING...EXCEPT A FEW BREAKS OVER THE YAKIMA VALLEY EXTENDING DOWN INTO CENTRAL OREGON. CURRENT RADAR IS INDICATING A FEW SPRINKLES OR LIGHT SHOWERS OVER THE NORTHERN BLUE MOUNTAINS AND BLUE MOUNTAIN FOOTHILLS...ANYTHING THAT FALLS WILL BE VERY LIGHT THROUGH 18Z. BY 19-21Z LATEST HRRR AND OTHER SHORT TERM GUIDANCE IS INDICATING SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS DEVELOPING OVER MUCH OF THE CWA IN RESPONSE TO INCREASED INSTABILITY ASSOCIATED WITH THE UPPER LEVEL LOW CENTERED OVER NORTHERN NEVADA. THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS WILL LIKELY BE FROM ABOUT 21Z THIS AFTERNOON THROUGH 03Z THIS EVENING. AFTER 03Z THIS EVENING SHOWERS AND ANY LINGERING STORMS WILL QUICKLY DECREASE IN COVERAGE AS WE LOSE DAYTIME HEATING AND INSTABILITY. AFTER 06Z MOST AREAS WILL DRY OUT WITH THE ONLY EXCEPTION BEING OVER THE NORTHERN BLUE MOUNTAINS AND ESPECIALLY WALLOWA COUNTY WHERE THERE WILL BE A SLIGHT CHC TO LOW END CHC FOR RAIN AND HIGHER ELEVATION SNOW SHOWERS THROUGH THE OVERNIGHT. SNOW LEVELS WILL BE BETWEEN 4500 TO 5200 FEET THIS AFTERNOON LOWERING SLIGHTLY TO BETWEEN 4200 TO 4700 FEET OVERNIGHT. TEMPERATURES LOOKED FINE FOR TODAY AND TONIGHT WITH THE LOWER ELEVATIONS AND BASINS RANGING FROM THE UPPER 50S TO MID 60S THIS AFTERNOON AND THE MOUNTAINS IN THE 40S TO AROUND 50. OVERNIGHT LOWS WILL REMAIN ABOVE FREEZING TONIGHT IN THE LOWER ELEVATIONS...MAINLY IN THE MID TO UPPER 30S. THE MOUNTAINS AND HIGHER PLATEAUS...INCLUDING CENTRAL OREGON...WILL FALL INTO THE 20S OVERNIGHT. WINDS WILL INCREASE AN BECOME BREEZY OUT OF THE NORTHWEST AT 8 TO 16 MPH FOR MOST LOCATIONS THIS AFTERNOON...ONE OF THE WINDIER SPOTS WILL BE THE GRANDE RONDE VALLEY WHERE WINDS OF AROUND 20 MPH WITH GUSTS TO 30-35 MPH ARE EXPECTED THIS AFTERNOON. 77 && .PREV DISC... /ISSUED 415 AM PDT WED APR 8 2015/ SHORT TERM...TODAY THROUGH THURSDAY NIGHT...AN UPPER TROUGH WILL REMAIN OVER THE REGION TODAY. A LOW CENTER AT THE BASE OF THE TROUGH WILL WEAKEN AND SLIDE EAST TO WYOMING TODAY. THIS LOW HAS BEEN SPREADING MOISTURE NORTH INTO CENTRAL AND NORTHEAST OREGON EARLY THIS MORNING. PRECIP ASSOCIATED WITH THIS WRAP AROUND MOISTURE HAS BEEN LIMITED THIS MORNING, MAINLY OVER CENTRAL OREGON. UPSLOPE AFFECTS HAVE BEEN CAUSING LOCALLY ENHANCED RAIN AND/OR SNOW SOUTH AND WEST OF BEND. THIS PRECIP SHOULD WIND DOWN TOWARDS DAYBREAK. BEFORE THEN, LOCAL SNOW AMOUNTS OF AN INCH OR TWO COULD ACCUMULATE OVER THESE UPSLOPE AREAS. LATE THIS MORNING THROUGH THIS EVENING, COLD AIR ALOFT COMBINED WITH DAYTIME HEATING SHOULD PRODUCE ENOUGH INSTABILITY FOR ISOLATED TO SCATTERED SHOWER OVER THE AREA. ALSO STRAY THUNDERSTORMS WILL BE POSSIBLE LATE AFTERNOON AND EARLY EVENING OVER MUCH OF THE ARE, THOUGH WESTERLY LOW LEVEL FLOW IS CURRENTLY EXPECTED TO INHIBIT STORM DEVELOPMENT FROM THE GORGE SOUTH TO CENTRAL OREGON. THE SHOWERS WILL DECREASE ACROSS THE AREA LATE THIS EVENING AND OVERNIGHT, WITH ONLY A FEW SHOWERS LINGERING OVER THE BLUES AND WALLOWA COUNTY. A WEAK PIECE OF ENERGY LOOKS TO DRIFT OVER THE REGION THURSDAY. THIS ENERGY IS EXPECTED TO CAUSE A FEW SHOWERS TO OCCUR OVER PORTIONS OF THE AREA, WITH THE POSSIBILITY OF A STRAY THUNDERSTORM OVER OUR NORTHEASTERN ZONES. THESE SHOWERS AND STORMS WILL DECREASE THROUGH THURSDAY EVENING, AND LARGELY END AFTER MIDNIGHT. 90 LONG TERM...FRIDAY THROUGH TUESDAY...FRIDAY AN UPPER LEVEL TROUGH WILL MOVE TOWARD WASHINGTON AND OREGON BRINGING WIND, RAIN AND MOUNTAIN SNOW FRIDAY NIGHT AND SATURDAY. BREEZY TO WINDY CONDITIONS WILL DEVELOP SATURDAY AS SURFACE PRESSURE GRADIENTS TIGHTEN BEHIND A COLD FRONT AND STRONGER WINDS ALOFT MIX TO THE SURFACE. SOME WIND ADVISORIES ARE POSSIBLE...PARTICULARLY IN THE LOWER COLUMBIA BASIN. STRONG COLD ADVECTION BEHIND THE FRONT WILL DROP SNOW LEVELS TO 2000-3000 FT BY SUNDAY MORNING. SATURDAY NIGHT AND SUNDAY WESTERLY FLOW WITH SOME EMBEDDED DISTURBANCES WILL BE OVER EASTERN WASHINGTON AND OREGON. THESE DISTURBANCES WILL KEEP SOME UPSLOPE SHOWERS OVER MOST OF THE AREA. AND TUESDAY MODELS DIVERGE SIGNIFICANTLY. ECMWF HAS A WEAK TROUGH DEVELOPING OVER WASHINGTON AND OREGON. GFS HAS A CLOSED LOW OVER THE EASTERN PACIFIC MONDAY THAT MOVES INLAND TUESDAY. GFS ENSEMBLES SHOW ENOUGH SPREAD TO COVER BOTH POSIBILITIES. THIS LOWERS CONFIDENCE IN ANY FORECAST TIMING AND STRENGTH MONDAY AND TUESDAY. GIVEN THE MODELS DIFFERENCES MADE FEW CHANGES TO CURRENT FORECAST OF A SLIGHT CHANCE OF RAIN SHOWERS IN THE LOWER ELEVATIONS AND A CHANCE OF RAIN AND SNOW IN THE MOUNTAINS SUNDAY NIGHT THROUGH TUESDAY. COONFIELD AVIATION...12Z TAFS...VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HOURS. A LOW OFF THE COAST WILL KEEP SOME MID AND HIGH LEVEL CLOUDS GENERALLY ABOVE 5000 FEET OVER THE AREA THROUGH THIS AFTERNOON. AFTERNOON CONVECTIVE SHOWERS AND PERHAPS A FEW ISOLATED THUNDERSTORMS ARE EXPECTED AFTER 20Z. NOT ENOUGH CONFIDENCE TO MENTION VCTS OR -TSRA IN THE TAFS. WINDS WILL GENERALLY REMAIN BELOW 15 KTS FOR THE NEXT 24 HOURS THOUGH KRDM, KBDN AND KDLS WILL HAVE GUSTS TO 20 KTS AFTER 21Z...SHOWERS EXPECTED TO DIMINISH AFTER 03Z THIS EVENING AT ALL TAF SITES. && .PRELIMINARY POINT TEMPS/POPS... PDT 60 37 63 38 / 30 30 10 20 ALW 62 42 64 42 / 30 30 20 20 PSC 65 38 67 37 / 20 30 10 10 YKM 62 37 64 35 / 30 20 10 10 HRI 64 37 67 34 / 30 30 10 10 ELN 62 36 65 33 / 30 20 10 10 RDM 54 24 61 28 / 40 20 10 10 LGD 55 33 57 34 / 40 40 20 30 GCD 56 32 62 33 / 50 40 20 20 DLS 63 40 68 40 / 20 20 10 10 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. && FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT... WWW.WEATHER.GOV/PENDLETON $$ 77/91/91
AREA FORECAST DISCUSSION
NWS MEDFORD OR
1013 PM PDT TUE APR 7 2015 .UPDATE...UPDATED POPS TO TAPER OFF WEST SIDE POPS TO SCATTERED SHOWERS AFTER MIDNIGHT AS THE UPPER LOW PULLS FARTHER TO THE EAST. /FB && .PREV DISCUSSION... /ISSUED 858 PM PDT TUE APR 7 2015/ DISCUSSION...THE CLOSED LOW PRESSURE HAS MOVED INTO NW CALIFORNIA. THIS LOW WILL CONTINUE TO MOVE TO THE E-SE AND THE CENTER IS EXPECTED TO BE IN NORTHERN NEVADA BY LATE TONIGHT. SATELLITE IMAGERY SHOWS CONTINUED UPSLOPE PRECIPITATION INTO THE WARNER MOUNTAINS AS WELL AS THE EAST SLOPES OF THE CASCADES. SHORT TERM HIGH RESOLUTION MODELS CONTINUE TO PAINT SNOW SHOWERS ACROSS THE WARNERS AS WELL AS THE MOUNTAINS OF EASTERN KLAMATH COUNTY, WHILE ROADCAMS CONTINUE TO SHOW SNOW SHOWERS OVER THE CASCADES PASSES. WILL KEEP THE CURRENT SUITE OF WINTER WEATHER ADVISORIES GOING THROUGH THE NIGHT. NEW MODEL RUNS SHOW NO BIG DEPARTURE FROM THE PREVIOUS FORECAST SO NO UPDATES WILL ISSUED THIS EVENING. /FB AVIATION...FOR THE 08/00Z TAF CYCLE...THIS EVENING THROUGH EARLY WEDNESDAY MORNING...EXPECT MVFR CIGS/VISIBILITY FROM THE CASCADES EASTWARD...WITH AREAS OF IFR IN LIGHT TO OCCASIONALLY MODERATE SNOW SHOWERS. TERRAIN OBSCURATION WILL BE WIDESPREAD. WEST OF THE CASCADES...EXPECT A MIX OF VFR/MVFR CIGS IN ISO/SCT SHOWERS WITH MOUNTAINS OBSCURED. CONDITIONS WILL LIKELY IMPROVE TO VFR FOR MOST AREAS MID TO LATE MORNING WEDNESDAY, THOUGH ISOLATED SHOWERS WILL PERSIST. SPILDE MARINE...UPDATED 400 PM PDT TUESDAY APR 07 2015...MAINLY LIGHT WINDS AND LOW SEAS ARE EXPECTED TONIGHT THROUGH THURSDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE WATERS. A COLD FRONT WILL MOVE THROUGH LATE FRIDAY OR FRIDAY NIGHT WITH SLIGHTLY HIGHER WINDS AND SEAS. A LARGER WESTERLY SWELL WILL ARRIVE LATER SATURDAY NIGHT AND PERSIST THROUGH MONDAY. SPILDE PREV DISCUSSION... /ISSUED 500 PM PDT TUE APR 7 2015/ SHORT TERM...THE UPPER LOW CURRENTLY OFF THE COAST IN NORTHWEST CAL IS MOVING SOUTH. WET SNOW CONTINUES IN SISKIYOU COUNTY, BUT IT`S BECOMING SHOWERY AND ROADS ARE WET. THE MODELS ARE IN PRETTY GOOD AGREEMENT SHOWING A DEFORMATION ZONE OF PRECIPITATION SETTING UP EAST OF THE CASCADES LATER THIS EVENING AND LASTING INTO WEDNESDAY MORNING, BUT DIFFER SLIGHTLY ON THE PLACEMENT OF THE CORE OF HEAVIEST QPF. THE LATEST HRRR SHOWS THE DEFORMATION ZONE WELL AND THE FORECAST FOR TONIGHT WILL LEAN TOWARDS THAT SOLUTION. GIVEN THAT THIS WILL SET UP AT NIGHT, THERE WILL BE AN OPPORTUNITY FOR SNOW TO ACCUMULATE ON ROADS DURING THE OVERNIGHT HOURS FOR MOST AREAS EAST OF THE CASCADES. THE CASCADES WILL ALSO GET ACCUMULATING SNOW TONIGHT, THUS HAVE EXTENDED THE END TIME OF THE WINTER WEATHER ADVISORY UNTIL WEDNESDAY MORNING. DETAILS CAN BE FOUND AT WSWMFR. GIVEN THE ABOVE MENTIONED SCENARIO, HAVE INCREASED POPS...QPF AND SNOW AMOUNTS SIGNIFICANTLY, BUT IT STILL MAY NOT BE ENOUGH. LATER SHIFTS MAY NEED TO TAKE ANOTHER LOOK AT THIS AND ADJUST AMOUNTS HIGHER IF LATER MODEL RUNS CONTINUE TO SHOW THE HIGHER QPF AMOUNTS. WEDNESDAY WILL BE A TRANSITION DAY WITH THE DEFORMATION ZONE WEAKENING IN THE MORNING. RAIN AND MOUNTAIN SNOW SHOWERS WILL CONTINUE IN THE AFTERNOON, BUT SNOW LEVELS WILL COME UP TO AROUND 5000 FEET IN THE AFTERNOON, SO NOT EXPECTING MUCH IF ANY ACCUMULATIONS FROM ABOUT MID MORNING WEDNESDAY ON DUE TO WARMING ROAD TEMPERATURES AND SPOTTY PRECIPITATION. DRY AND MILDER WEATHER FINALLY RETURNS THURSDAY AND CONTINUES INTO THURSDAY NIGHT WITH SHORTWAVE RIDGING BUILDING INTO THE AREA. MOST OF FRIDAY WILL BE DRY, THEN THE NEXT FRONT WILL REACH THE COAST TOWARDS FRIDAY EVENING. THE GFS AND NAM ARE SLOWER WITH THE ARRIVAL OF THE FRONT WHILE THE EC IS FASTER. FOR NOW WENT WITH A BLEND BETWEEN THE TWO, BUT THE UPPER FLOW IS WEST OT NORTHWEST WHICH NORMALLY LEADS TO QUICKER ARRIVAL TIMES OF FRONTS. -PETRUCELLI LONG TERM...THE ACTIVE PATTERN CONTINUES IN THE LONG TERM WITH ANOTHER FRONTAL BOUNDARY MOVING INTO THE AREA LATE FRIDAY NIGHT INTO SATURDAY MORNING. THE MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH THE LONG TERM. THE EC IS A BIT FASTER TO PUSH THE FRONT INLAND ON SATURDAY COMPARED TO THE GFS BUT BOTH MODELS HAVE IT PUSHED THROUGH THE AREA BY LATE SATURDAY NIGHT. ZONAL FLOW WILL SET UP FOR SUNDAY AND THE GFS IS HINTING AT SOME UPSLOPE SHOWERS CONTINUING ALONG THE CASCADES THROUGH SUNDAY AFTERNOON. THERE MAY ALSO BE SOME LINGERING SHOWERS FOR THE NORTHERN PORTION OF THE CWA...MAINLY FROM THE UMPQUA DIVIDE NORTH. OTHERWISE, SUNDAY LOOKS TO BE THE DRIEST DAY, RELATIVELY, THROUGH THE EXTENDED TERM. BY MONDAY MORNING, THE MODELS ARE SLIGHTLY DIFFERENT IN THE TIMING AND STRENGTH OF THE NEXT SYSTEM TO MOVE THROUGH. THE GFS IS FASTER AND DEEPER WITH THE NEXT TROUGH, MEANING COOLER TEMPERATURES AND LOWER SNOW LEVELS COMPARED TO THE EC...WHICH IS SLOWER BY ABOUT 12 HOURS AND NOT AS DEEP WITH THE TROUGH. EITHER WAY, IT LOOKS LIKE UNSETTLED WEATHER WILL CONTINUE THROUGH THE END OF THE EXTENDED TERM. MND AVIATION...FOR THE 08/00Z TAF CYCLE...THIS EVENING THROUGH EARLY WEDNESDAY MORNING...EXPECT MVFR CIGS/VISIBILITY FROM THE CASCADES EASTWARD...WITH AREAS OF IFR IN LIGHT TO OCCASIONALLY MODERATE SNOW SHOWERS. TERRAIN OBSCURATION WILL BE WIDESPREAD. WEST OF THE CASCADES...EXPECT A MIX OF VFR/MVFR CIGS IN ISO/SCT SHOWERS WITH MOUNTAINS OBSCURED. CONDITIONS WILL LIKELY IMPROVE TO VFR FOR MOST AREAS MID TO LATE MORNING WEDNESDAY, THOUGH ISOLATED SHOWERS WILL PERSIST. SPILDE MARINE...UPDATED 500 PM PDT TUESDAY APR 07 2015...MAINLY LIGHT WINDS AND LOW SEAS ARE EXPECTED TONIGHT THROUGH THURSDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE WATERS. A COLD FRONT WILL MOVE THROUGH LATE FRIDAY OR FRIDAY NIGHT WITH SLIGHTLY HIGHER WINDS AND SEAS. A LARGER WESTERLY SWELL WILL ARRIVE LATER SATURDAY NIGHT AND PERSIST THROUGH MONDAY. SPILDE && .MFR WATCHES/WARNINGS/ADVISORIES... OR...WINTER WEATHER ADVISORY UNTIL 9 AM PDT WEDNESDAY FOR ORZ029>031-624-625. WINTER WEATHER ADVISORY UNTIL 9 AM PDT WEDNESDAY FOR ORZ027-028-617-621-623. CA...WINTER WEATHER ADVISORY UNTIL 9 AM PDT WEDNESDAY FOR CAZ085-285. PACIFIC COASTAL WATERS...NONE. $$ FJB/CC/FJB
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1110 PM EDT THU APR 9 2015 .SYNOPSIS... STRONG HIGH PRESSURE RIDGING SOUTHWEST INTO THE STATE FROM THE CANADIAN MARITIMES WILL CONTINUE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH TONIGHT. LOW PRESSURE WILL MOVE THROUGH THE GREAT LAKES LATE TONIGHT AND FRIDAY...DRAGGING A COLD FRONT ACROSS PENNSYLVANIA FRIDAY. MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER VALUES NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME THIS EVENING BETWEEN STRONG-COLD HIGH PRESSURE OVER THE CANADIAN MARITIMES AND A NEARLY STATIONARY FRONTAL SYSTEM TO OUR WEST AND SOUTH. REGIONAL RADAR MOSAIC AT 0130Z SHOWS FAIRLY WIDESPREAD SHOWERS ACROSS CENTRAL PA IN REGION OF LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING UP THE OHIO VALLEY. WILL MAINTAIN CAT TO LIKELY POPS ACROSS THE ENTIRE AREA THRU MUCH OF THE NIGHT...AS LL JET AND ASSOC PLUME OF ANOMALOUS PWATS OVERRUN BOUNDARY TO OUR WEST. ALTHOUGH THE ENTIRE CWA REMAINS IN THE STABLE AIR EAST OF THE FRONT...ELEVATED TSRA IS CERTAINLY POSSIBLE OVERNIGHT ACROSS THE WESTERN AND CENTRAL COUNTIES...WHERE RAP SHOWS SOME MARGINAL ELEVATED INSTABILITY OVERNIGHT. HAVE ALSO ADDED AREAS OF DZ OVERNIGHT...DUE TO NEARLY SATURATED SFC-850MB LYR AND SERLY FLOW/OROGRAPHIC LIFT. A LULL IN THE SHOWER ACTIVITY SEEMS LIKELY LATE TONIGHT/EARLY FRI AM...AS SHORTWAVE LIFTS NORTHEAST OF PA AND APPROACHING COLD FRONT REMAINS WEST OF THE STATE. OVERNIGHT LOWS WILL RANGE FROM 40-45F OVER MOST OF THE AREA. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... OPERATIONAL MODELS ARE IN GOOD AGREEMENT WITH HAVING THE COLD /OCCLUDED/ FRONT TRACKING SE ACROSS THE CWA BTWN 15Z-20Z. LOOKS LIKE ONLY THE S TIER COUNTIES WILL BRIEFLY BREAK INTO THE WARM SECTOR AND LATEST SREF/GEFS CONTINUE TO PRODUCE SOME MARGINAL CAPES ACROSS THE SE COUNTIES DURING THE AFTN. SPC CONTINUES TO HIGHLIGHT THIS AREA FOR A SLIGHT RISK OF SVR WX IN THE AFTN. EARLY LOW CLOUDS/PATCHY DRIZZLE SHOULD GIVE WAY TO A ROUND OF SHOWERS AND POSS TSRA AS POTENT MID LVL SHORTWAVE PUSHES FRONT THRU DURING THE LATE AM AND AFTN. ALTHOUGH RAINFALL AMTS NOT EXPECTED TO BE SIGNIFICANT /LESS THAN A QUARTER INCH BASED ON MDL BLEND/ HAVE INCREASED POPS TO NR 90 PCT ACROSS THE ENTIRE AREA BASED ON SREF/GEFS PLUME DATA. ALSO...GIVEN POSITIVE PWAT ANOMALIES OF 2-3SD AND STRONG LG SCALE FORCING ACCOMPANYING FRONT...HARD TO SEE MANY SPOTS MISSING OUT ON AT LEAST SOME RAIN FRIDAY. DESPITE ABUNDANT CLOUD COVER...TEMPS WILL REBOUND FRIDAY AS LOW LVL COOL AIR IS SCOURED OUT. WIDESPREAD 60S EXPECTED FOR HIGHS...WITH L70S EVEN POSSIBLE ACROSS THE S TIER VALLEYS. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... COLD FRONT EXITING TO THE SOUTHEAST BY FRI NIGHT...WILL BE FOLLOWED BY A RATHER STRONG SMALL UPPER LEVEL TROUGH FRIDAY NIGHT INTO SAT. DYNAMICS LOOK STRONG ENOUGH TO MAINTAIN CHANCE FOR SHOWERS...TAPERING BACK TO SPRINKLES ON SAT AS THEY MOVE AWAY. ANY SHOWERS WILL BE ON THE LIGHT SIDE. BREEZY WITH A QUICK SHOT OF COOLER AIR ON SAT...THEN WARMER AIR RETURNS ON SUNDAY INTO MONDAY AS RIDGE BUILDS IN. MENTION OF POPS RETURNS LATE MONDAY INTO TUE AS ANOTHER FRONT TRACKS ACROSS THE REGION. AGAIN...PRECIP AMOUNTS LOOK TO REMAIN ON THE LIGHT SIDE. SHARP RIDGE BUILDS IN FOR MID/LATE WEEK AS SOUTHERLY WINDS BRING A PERIOD OF MILD WEATHER. WEAKENING SYSTEM OVER THE UPPER MIDWEST MAY BRING SHOWERY WEATHER BACK INTO PA FOR THU/FRI. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... FRONTAL BOUNDARY REMAINS DRAPED NORTH TO SOUTH ACROSS WESTERN PA THEN SOUTH INTO THE CAROLINAS AS COLD AIR IS DAMMED UP AGAINST THE MTNS...SUPPORTING THE COOL AND MOIST AIR MASS COVERING MOST OF CENTRAL PA. SHORTWAVE ENERGY MOVING ACROSS THE OHIO VALLEY HAS/WILL PUSHED SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS INTO PA. RAIN AND A FEW EMBEDDED THUNDERSTORMS WILL EXIT THE EASTERN SECTIONS OF THE AIRSPACE. BEHIND THIS SCATTERED SHOWERS AND THUNDERSTORMS ARE DEVELOPING IN THE MOIST AIRMASS. THE PLENTIFUL LOW LEVEL MOISTURE WILL KEEP WIDESPREAD IFR-MVFR CONDITIONS ACROSS MOST OF THE THE REGION INTO THE OVERNIGHT. SOME IMPROVEMENT HAS MANAGED TO CREEP INTO MY FAR WESTERN TERMINALS...BUT THIS WILL LIKELY NOT BE LONG LIVED AS SHOWERS AND THUNDERSTORMS ENTERING WESTERN PA PROGRESS EASTWARD THROUGH THE LATE AFTERNOON AND EVENING. LLWS IS POSSIBLE OVERNIGHT AND INTO FRIDAY AFTERNOON AS SFC WINDS REMAIN OUT OF THE SOUTHEAST...AND WINDS JUST ABOVE THE SURFACE INCREASE OUT OF THE SOUTHWEST AT 30-50KT. A COLD FRONT WILL SWEEP ACROSS THE REGION FRIDAY...CLEARING THE LOWER SUSQ VALLEY BY 21-00Z. WINDS SHIFTING TO THE WEST WILL FINALLY SCOUR OUT THE STUBBORN LOW CLOUDS WITH WIDESPREAD VFR CONDITIONS DEVELOPING DURING THE AFTERNOON INTO THE EVENING. ISOLATED STRONG THUNDERSTORMS WILL BE POSSIBLE OVER THE LOWER SUSQ VALLEY WITH THE COLD FRONT FRIDAY AFTERNOON. OUTLOOK... SAT-SUN...VFR. MON...COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS ALONG WITH LOCALLY REDUCED CONDITIONS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD/LA CORTE LONG TERM...RXR AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1006 PM EDT THU APR 9 2015 .SYNOPSIS... STRONG HIGH PRESSURE RIDGING SOUTHWEST INTO THE STATE FROM THE CANADIAN MARITIMES WILL CONTINUE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH TONIGHT. LOW PRESSURE WILL MOVE THROUGH THE GREAT LAKES LATE TONIGHT AND FRIDAY...DRAGGING A COLD FRONT ACROSS PENNSYLVANIA FRIDAY. MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER VALUES NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME THIS EVENING BETWEEN STRONG-COLD HIGH PRESSURE OVER THE CANADIAN MARITIMES AND A NEARLY STATIONARY FRONTAL SYSTEM TO OUR WEST AND SOUTH. REGIONAL RADAR MOSAIC AT 0130Z SHOWS FAIRLY WIDESPREAD SHOWERS ACROSS CENTRAL PA IN REGION OF LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING UP THE OHIO VALLEY. WILL MAINTAIN CAT TO LIKELY POPS ACROSS THE ENTIRE AREA THRU MUCH OF THE NIGHT...AS LL JET AND ASSOC PLUME OF ANOMALOUS PWATS OVERRUN BOUNDARY TO OUR WEST. ALTHOUGH THE ENTIRE CWA REMAINS IN THE STABLE AIR EAST OF THE FRONT...ELEVATED TSRA IS CERTAINLY POSSIBLE OVERNIGHT ACROSS THE WESTERN AND CENTRAL COUNTIES...WHERE RAP SHOWS SOME MARGINAL ELEVATED INSTABILITY OVERNIGHT. HAVE ALSO ADDED AREAS OF DZ OVERNIGHT...DUE TO NEARLY SATURATED SFC-850MB LYR AND SERLY FLOW/OROGRAPHIC LIFT. A LULL IN THE SHOWER ACTIVITY SEEMS LIKELY LATE TONIGHT/EARLY FRI AM...AS SHORTWAVE LIFTS NORTHEAST OF PA AND APPROACHING COLD FRONT REMAINS WEST OF THE STATE. OVERNIGHT LOWS WILL RANGE FROM 40-45F OVER MOST OF THE AREA. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... OPERATIONAL MODELS ARE IN GOOD AGREEMENT WITH HAVING THE COLD /OCCLUDED/ FRONT TRACKING SE ACROSS THE CWA BTWN 15Z-20Z. LOOKS LIKE ONLY THE S TIER COUNTIES WILL BRIEFLY BREAK INTO THE WARM SECTOR AND LATEST SREF/GEFS CONTINUE TO PRODUCE SOME MARGINAL CAPES ACROSS THE SE COUNTIES DURING THE AFTN. SPC CONTINUES TO HIGHLIGHT THIS AREA FOR A SLIGHT RISK OF SVR WX IN THE AFTN. EARLY LOW CLOUDS/PATCHY DRIZZLE SHOULD GIVE WAY TO A ROUND OF SHOWERS AND POSS TSRA AS POTENT MID LVL SHORTWAVE PUSHES FRONT THRU DURING THE LATE AM AND AFTN. ALTHOUGH RAINFALL AMTS NOT EXPECTED TO BE SIGNIFICANT /LESS THAN A QUARTER INCH BASED ON MDL BLEND/ HAVE INCREASED POPS TO NR 90 PCT ACROSS THE ENTIRE AREA BASED ON SREF/GEFS PLUME DATA. ALSO...GIVEN POSITIVE PWAT ANOMALIES OF 2-3SD AND STRONG LG SCALE FORCING ACCOMPANYING FRONT...HARD TO SEE MANY SPOTS MISSING OUT ON AT LEAST SOME RAIN FRIDAY. DESPITE ABUNDANT CLOUD COVER...TEMPS WILL REBOUND FRIDAY AS LOW LVL COOL AIR IS SCOURED OUT. WIDESPREAD 60S EXPECTED FOR HIGHS...WITH L70S EVEN POSSIBLE ACROSS THE S TIER VALLEYS. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... COLD FRONT EXITING TO THE SOUTHEAST BY FRI NIGHT...WILL BE FOLLOWED BY A RATHER STRONG SMALL UPPER LEVEL TROUGH FRIDAY NIGHT INTO SAT. DYNAMICS LOOK STRONG ENOUGH TO MAINTAIN CHANCE FOR SHOWERS...TAPERING BACK TO SPRINKLES ON SAT AS THEY MOVE AWAY. ANY SHOWERS WILL BE ON THE LIGHT SIDE. BREEZY WITH A QUICK SHOT OF COOLER AIR ON SAT...THEN WARMER AIR RETURNS ON SUNDAY INTO MONDAY AS RIDGE BUILDS IN. MENTION OF POPS RETURNS LATE MONDAY INTO TUE AS ANOTHER FRONT TRACKS ACROSS THE REGION. AGAIN...PRECIP AMOUNTS LOOK TO REMAIN ON THE LIGHT SIDE. SHARP RIDGE BUILDS IN FOR MID/LATE WEEK AS SOUTHERLY WINDS BRING A PERIOD OF MILD WEATHER. WEAKENING SYSTEM OVER THE UPPER MIDWEST MAY BRING SHOWERY WEATHER BACK INTO PA FOR THU/FRI. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... PLENTIFUL LOW LEVEL MOISTURE WILL KEEP WIDESPREAD IFR-MVFR CONDITIONS ACROSS MOST OF THE THE REGION INTO THE OVERNIGHT. SOME IMPROVEMENT HAS MANAGED TO CREEP INTO MY FAR WESTERN TERMINALS...BUT THIS WILL LIKELY NOT BE LONG LIVED AS SHOWERS AND THUNDERSTORMS ENTERING WESTERN PA PROGRESS EASTWARD THROUGH THE LATE AFTERNOON AND EVENING. LLWS IS POSSIBLE THIS EVENING AS SFC WINDS REMAIN OUT OF THE SOUTHEAST...AND WINDS JUST ABOVE THE SURFACE INCREASE OUT OF THE SOUTHWEST AT 30-50KT. A COLD FRONT WILL SWEEP ACROSS THE REGION FRIDAY...CLEARING THE LOWER SUSQ VALLEY BY 21-00Z. WINDS SHIFTING TO THE WEST WILL FINALLY SCOUR OUT THE STUBBORN LOW CLOUDS WITH WIDESPREAD VFR CONDITIONS DEVELOPING DURING THE AFTERNOON INTO THE EVENING. ISOLATED STRONG THUNDERSTORMS WILL BE POSSIBLE OVER THE LOWER SUSQ VALLEY WITH THE COLD FRONT FRIDAY AFTERNOON. OUTLOOK... SAT-SUN...VFR. MON...COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS ALONG WITH LOCALLY REDUCED CONDITIONS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD/LA CORTE LONG TERM...RXR AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
601 PM EDT WED APR 8 2015 .SYNOPSIS... A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA AND STRONG HIGH PRESSURE OVER QUEBEC WILL COMBINE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH THURSDAY. A STORM SYSTEM WILL BRING A COLD FRONT ACROSS PENNSYLVANIA DURING FRIDAY. AFTER A WARM DAY ON FRIDAY...MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER CONDITIONS NEXT WEEK. THERE COULD BE A SHOWER FROM TIME TO TIME NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE OVER THE APPALACHIANS. MAIN FEATURE OF NOTE THIS EVENING IS WELL DEFINED SHORTWAVE/MCV TRACKING ACROSS SOUTHERN PA. REGIONAL RADAR LOOP AT 21Z SHOWS WEAKENING CONVECTION MOVING INTO THE ALLEGHENY MTNS AS IT ENCOUNTERS COOL/STABLE AIR MASS. HOWEVER...LG SCALE FORCING AHEAD OF THIS FEATURE WILL LIKELY SUPPORT A PERIOD OF SHOWERS ACROSS MOST OF CENTRAL PA AS IT MOVES THRU THIS EVENING. RADAR TRENDS AND LATEST HRRR OUTPUT SUGGEST THE SHOWERS WILL BE EXITING THE EASTERN COUNTIES BY ARND 03Z. IN THE WAKE OF THIS EVENING/S SHORTWAVE...EXPECT DRY CONDS FOR MOST OF THE REGION LATE TONIGHT. THE EXCEPTION WILL BE ACROSS THE SOUTHWEST COUNTIES...WHERE SHOWERS MAY ARRIVE TOWARD DAWN IN ASSOC WITH INCREASING ISENTROPIC LIFT IN ADVANCE OF DEVELOPING STORM SYSTEM/SOUTHERLY LL JET OVR THE MIDWEST. BLEND OF LATEST GUIDANCE KEEPS TEMPS NEARLY STEADY OVERNIGHT WITH LOWS RANGING FROM THE U30S OVR THE HIGH TERRAIN NORTH AND EAST OF KIPT...TO THE M40S ALONG THE SPINE OF THE ALLEGHENY MTNS. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... ANOTHER COOL/CLOUDY DAY ON TAP FOR THURSDAY...AS CENTRAL PA REMAINS IN CAD REGIME. THERE WILL BE AN INCREASING CHC OF SHOWERS...ESP OVR THE NW MTNS BY AFTN...AS SWRLY LL JET ASSOC WITH DEVELOPING LOW OVR THE MIDWEST APPROACHES. GEFS 8H MFLUX VALUES SKYROCKET TO 5SD ABV NORMAL ACROSS NW PA BY 00Z THU. BASED ON LATEST ENSEMBLE OUTPUT...WILL MAINTAIN CATEGORICAL POPS ACROSS THE NW MTNS...TO CHC ACROSS THE LOWER SUSQ VALLEY. LIFTED INDEX PROGS INDICATE ALL OF CENTRAL PA WILL REMAIN STRONGLY DAMMED. HOWEVER...ELEVATED TSRA A DEFINITE POSSIBILITY ACROSS THE NW COUNTIES LATE IN THE DAY. HIGHS WILL BE WITHIN A DEGREE OR TWO OF TODAY IN MOST AREAS. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... NOT A LOT OF CHANGE TO PACKAGE FROM RECENT DAYS. MAIN CHANGE WAS TO UP TEMPERATURES THU NIGHT...GIVEN THAT 850 MB FRONT IS WELL NORTH OF THE AREA...AND VERY STRONG LOW LEVEL FLOW IS EXPECTED ACROSS THE AREA. ALSO DID UP TEMPERATURES ON FRIDAY...GIVEN NEW GUIDANCE AND THAT 850 MB FRONT IS NORTH OF THE AREA. HAVE INCREASING CONCERN FOR AT LEAST A FEW STRONG STORMS ACROSS THE AREA. EARLY ON...FAR WEST MAY SEE ONE...GIVEN STRONGER WIND FIELDS TO THE WEST. LATER ON...TEMPERATURES IN THE 70 TO 75 DEGREE RANGE...WITH DEWPTS IN THE 50S...MAY LEAD SOME STORMS LATER IN THE AFT...EVEN WITH NOT THE BEST HEIGHT FALLS. ONE ONLY HAS TO LOOK OVER COLD LAKE ERIE. CONVECTION FORMED ALONG THE LAKE SHORE...WITH JUST SOME MINOR AMTS OF HEATING THIS AFT. ANYWAY...DID LOWER TEMPS FOR FRIDAY NIGHT INTO SAT. A RATHER STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE FRIDAY INTO SAT. MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION USUALLY LEADS TO SOME SHOWERS. OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE. FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO. && .AVIATION /22Z WEDNESDAY THROUGH MONDAY/... WIDESPREAD IFR/MVFR WILL CONTINUE NORTH OF THE FRONTAL SYSTEM THAT IS STALLED SOUTH OF PA. THIS STATIONARY FRONTAL BOUNDARY WILL KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT AND THURSDAY. AREAS OF DRIZZLE WITH SCATTERED SHOWERS WILL BE THE RULE WITH LITTLE IF ANY IMPROVEMENT EXPECTED. WINDS WILL REMAIN FROM THE EAST OR SOUTHEAST AT 5-10 MPH THROUGH THE PERIOD. OUTLOOK... FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. SAT-MON...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/MARTIN NEAR TERM...FITZGERALD/LA CORTE SHORT TERM...FITZGERALD/LA CORTE LONG TERM...MARTIN AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
336 PM EDT WED APR 8 2015 .SYNOPSIS... A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA AND STRONG HIGH PRESSURE OVER QUEBEC WILL COMBINE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH THURSDAY. A STORM SYSTEM WILL BRING A COLD FRONT ACROSS PENNSYLVANIA DURING FRIDAY. AFTER A WARM DAY ON FRIDAY...MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER CONDITIONS NEXT WEEK. THERE COULD BE A SHOWER FROM TIME TO TIME NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... WE REMAIN FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE OVER SOUTHERN CANADA AND A STATIONARY FRONT WHICH DOG LEGS FROM WRN PA SOUTH THROUGH WEST VIRGINIA ALL THE WAY THROUGH SOUTHERN VA BEFORE TURNING EAST AND OFF THE COAST NEAR THE DEL MARVA. ALOFT WE ARE ACTUALLY UNDER A FLAT UPPER RIDGE WITH 500 HEIGHTS THAT ARE SLIGHTLY ABOVE NORMAL FOR THE SEASON. HOWEVER THE FAST WSW FLOW IS SERVING AS A PATHWAY TO FUNNEL WEAK SHORTWAVES AND MOISTURE OUR WAY FROM THE LARGE SCALE UPPER TROF OVER THE ROCKY MOUNTAIN STATES. THE WARM-MOIST ADVECTION IS PROGGED TO CONTINUE AS THE SURFACE HIGH TO OUR NORTH STUBBORNLY MAINTAINS A LOW LEVEL EAST OR SOUTHEAST FLOW. WHILE THE AREA OF MORE ORGANIZED SHOWERS HAS MOVED OUT OF MY EASTERN ZONES...WE CANNOT RULE OUT THE THREAT FOR MORE RAIN THROUGH LATE DAY AS THE WEAK LIFT CONTINUES. I EVEN INTRODUCED A SMALL CHANCE FOR A RUMBLE OF THUNDER. DESPITE HIGH TEMPS THAT WILL ONLY AVERAGE IN THE 40S OVER MOST OF THE AREA...MID LEVEL LAPSE RATES ARE SHOWN BY THE RAP TO EXCEED 6C/KM AS THE MOIST WARM ADVECTION CONTINUES...SO SOME ELEVATED CONVECTION CANNOT BE RULED OUT. HIGH TEMPS THIS AFTERNOON WILL AVERAGE IN THE LOW TO MID 40S. FAR SWRN ZONES MAY BREAK OUT INTO THE MID 50S FOR A SHORT TIME. CLOUDY...COOL AND DAMP CONDITIONS WILL CONTINUE TONIGHT AS HIGH PRESSURE OVER QUEBEC CANADA NOSES SWWD INTO THE STATE ACCOMPANIED BY A LIGHT EAST TO NE BREEZE. THIS SHOULD LEAD TO WIDESPREAD LOW CLOUDS AND RIDGE-SHROUDING FOG ACROSS MUCH OF THE REGION WITH THE LOWEST VSBYS ON THE EAST FACING UPPER SLOPES. MAIN QUESTION WILL CENTER ON HOW MUCH OF THE OHIO CONVECTION CAN SURVIVE THE TREK INTO OUR WEDGE OF COLD AND STABLE AIR. LATEST HRRR SHOWS A CLUSTER OF SHOWERS MOVING ACROSS FAR NRN PA THROUGH EARLY EVENING WHILE THE MAIN MCS/BOW ECHO TRACKS OFF TO OUR SOUTH TOWARD THE DEEPEST INSTABILITY. FOR MOST OF PA THE HRRR SHOWS THE CHANCE OF SCATTERED SHOWERS NOT SHOWING ANY PARTICULAR ORGANIZATION. A BLEND OF MODEL POPS SHOWS PRETTY MUCH A 50-50 COIN FLIP FOR RAIN IN MOST AREAS OVERNIGHT...BUT THAT SEEMS A PRETTY ACCURATE REPRESENTATION FOR WHAT IS LIKELY TO OCCUR. ALONG WITH AREAS OF FOG AND DRIZZLE IT POINTS TO MORE COOL-DAMP CONDITIONS OVERNIGHT. LATEST HIGH RES GUIDANCE KEEPS OVERNIGHT LOWS MAINLY IN THE 40S...MINIMIZING THE THREAT FOR POCKETS OF FREEZING DRIZZLE OVER OUR FAR NERN ZONES THAT WE WERE CONCERNED WITH EARLIER. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... THURSDAY LOOKS LIKE A CARBON COPY OF TODAY AS THE HIGH ONLY SLOWLY RETREATS TOWARD THE CANADIAN MARITIMES. LIFTED INDEX PROGS INDICATE WE REMAIN STRONGLY DAMMED OVER MOST OF THE AREA THROUGHOUT THE DAY WHILE WARM MOIST ADVECTION OVER THE LOW LEVEL COLD WEDGE KEEPS US VULNERABLE TO SCATTERED SHOWERS AND POSSIBLY AN ELEVATED THUNDERSTORM. HARD TO TIME IN ANY PARTICULAR FEATURE AT THIS RANGE...AS THIS WILL LIKELY DEPEND ON ANY REMNANTS OF OHIO VALLEY CONVECTION THAT CAN ORGANIZE IN THE HIGH CAPE AIR IN THE WARM SECTOR. HIGHS WILL BE WITHIN A DEGREE OR TOW OF TODAY IN MOST AREAS. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... NOT A LOT OF CHANGE TO PACKAGE FROM RECENT DAYS. MAIN CHANGE WAS TO UP TEMPERATURES THU NIGHT...GIVEN THAT 850 MB FRONT IS WELL NORTH OF THE AREA...AND VERY STRONG LOW LEVEL FLOW IS EXPECTED ACROSS THE AREA. ALSO DID UP TEMPERATURES ON FRIDAY...GIVEN NEW GUIDANCE AND THAT 850 MB FRONT IS NORTH OF THE AREA. HAVE INCREASING CONCERN FOR AT LEAST A FEW STRONG STORMS ACROSS THE AREA. EARLY ON...FAR WEST MAY SEE ONE...GIVEN STRONGER WIND FIELDS TO THE WEST. LATER ON...TEMPERATURES IN THE 70 TO 75 DEGREE RANGE...WITH DEWPTS IN THE 50S...MAY LEAD SOME STORMS LATER IN THE AFT...EVEN WITH NOT THE BEST HEIGHT FALLS. ONE ONLY HAS TO LOOK OVER COLD LAKE ERIE. CONVECTION FORMED ALONG THE LAKE SHORE...WITH JUST SOME MINOR AMTS OF HEATING THIS AFT. ANYWAY...DID LOWER TEMPS FOR FRIDAY NIGHT INTO SAT. A RATHER STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE FRIDAY INTO SAT. MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION USUALLY LEADS TO SOME SHOWERS. OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE. FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... WIDESPREAD IFR/MVFR WILL CONTINUE NORTH OF THE FRONTAL SYSTEM THAT IS STALLED SOUTH OF PA. THIS STATIONARY FRONTAL BOUNDARY WILL KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT AND THURSDAY. AREAS OF DRIZZLE WITH SCATTERED SHOWERS WILL BE THE RULE WITH LITTLE IF ANY IMPROVEMENT EXPECTED. WINDS WILL REMAIN FROM THE EAST OR SOUTHEAST AT 5-10 MPH THROUGH THE PERIOD. OUTLOOK... FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. SAT-MON...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/MARTIN NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...MARTIN AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
110 PM EDT WED APR 8 2015 .SYNOPSIS... A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA AND STRONG HIGH PRESSURE OVER QUEBEC WILL COMBINE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH THURSDAY. A STORM SYSTEM WILL BRING A COLD FRONT ACROSS PENNSYLVANIA DURING FRIDAY. MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... WE REMAIN FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE OVER SOUTHERN CANADA AND A STATIONARY FRONT WHICH DOG LEGS FROM WRN PA SOUTH THROUGH WEST VIRGINIA ALL THE WAY THROUGH SOUTHERN VA BEFORE TURNING EAST AND OFF THE COAST NEAR THE DEL MARVA. ALOFT WE ARE ACTUALLY UNDER A FLAT UPPER RIDGE WITH 500 HEIGHTS THAT ARE SLIGHTLY ABOVE NORMAL FOR THE SEASON. HOWEVER THE FAST WSW FLOW IS SERVING AS A PATHWAY TO FUNNEL WEAK SHORTWAVES AND MOISTURE OUR WAY FROM THE LARGE SCALE UPPER TROF OVER THE ROCKY MOUNTAIN STATES. THE WARM-MOIST ADVECTION IS PROGGED TO CONTINUE AS THE SURFACE HIGH TO OUR NORTH STUBBORNLY MAINTAINS A LOW LEVEL EAST OR SOUTHEAST FLOW. WHILE THE AREA OF MORE ORGANIZED SHOWERS HAS MOVED OUT OF MY EASTERN ZONES...WE CANNOT RULE OUT THE THREAT FOR MORE RAIN THROUGH LATE DAY AS THE WEAK LIFT CONTINUES. I EVEN INTRODUCED A SMALL CHANCE FOR A RUMBLE OF THUNDER. DESPITE HIGH TEMPS THAT WILL ONLY AVERAGE IN THE 40S OVER MOST OF THE AREA...MID LEVEL LAPSE RATES ARE SHOWN BY THE RAP TO EXCEED 6C/KM AS THE MOIST WARM ADVECTION CONTINUES...SO SOME ELEVATED CONVECTION CANNOT BE RULED OUT. HIGH TEMPS THIS AFTERNOON WILL AVERAGE IN THE LOW TO MID 40S. FAR SWRN ZONES MAY BREAK OUT INTO THE MID 50S FOR A SHORT TIME. CLOUDY...COOL AND DAMP CONDITIONS WILL CONTINUE TONIGHT AS HIGH PRESSURE OVER QUEBEC CANADA NOSES SWWD INTO THE STATE ACCOMPANIED BY A LIGHT EAST TO NE BREEZE. THIS SHOULD LEAD TO WIDESPREAD LOW CLOUDS AND RIDGE-SHROUDING FOG ACROSS MUCH OF THE REGION WITH THE LOWEST VSBYS ON THE EAST FACING UPPER SLOPES. MAIN QUESTION WILL CENTER ON HOW MUCH OF THE OHIO CONVECTION CAN SURVIVE THE TREK INTO OUR WEDGE OF COLD AND STABLE AIR. LATEST HRRR SHOWS A CLUSTER OF SHOWERS MOVING ACROSS FAR NRN PA THROUGH EARLY EVENING WHILE THE MAIN MCS/BOW ECHO TRACKS OFF TO OUR SOUTH TOWARD THE DEEPEST INSTABILITY. FOR MOST OF PA THE HRRR SHOWS THE CHANCE OF SCATTERED SHOWERS NOT SHOWING ANY PARTICULAR ORGANIZATION. A BLEND OF MODEL POPS SHOWS PRETTY MUCH A 50-50 COIN FLIP FOR RAIN IN MOST AREAS OVERNIGHT...BUT THAT SEEMS A PRETTY ACCURATE REPRESENTATION FOR WHAT IS LIKELY TO OCCUR. ALONG WITH AREAS OF FOG AND DRIZZLE IT POINTS TO MORE COOL-DAMP CONDITIONS OVERNIGHT. LATEST HIGH RES GUIDANCE KEEPS OVERNIGHT LOWS MAINLY IN THE 40S...MINIMIZING THE THREAT FOR POCKETS OF FREEZING DRIZZLE OVER OUR FAR NERN ZONES THAT WE WERE CONCERNED WITH EARLIER. && .SHORT TERM /THURSDAY/... THURSDAY LOOKS LIKE A CARBON COPY OF TODAY AS THE HIGH ONLY SLOWLY RETREATS TOWARD THE CANADIAN MARITIMES. LIFTED INDEX PROGS INDICATE WE REMAIN STRONGLY DAMMED OVER MOST OF THE AREA THROUGHOUT THE DAY WHILE WARM MOIST ADVECTION OVER THE LOW LEVEL COLD WEDGE KEEPS US VULNERABLE TO SCATTERED SHOWERS AND POSSIBLY AN ELEVATED THUNDERSTORM. HARD TO TIME IN ANY PARTICULAR FEATURE AT THIS RANGE...AS THIS WILL LIKELY DEPEND ON ANY REMNANTS OF OHIO VALLEY CONVECTION THAT CAN ORGANIZE IN THE HIGH CAPE AIR IN THE WARM SECTOR. HIGHS WILL BE WITHIN A DEGREE OR TOW OF TODAY IN MOST AREAS. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... WARMER AIR WILL WORK INTO THE AREA LATE THU INTO FRIDAY...AS LOW LEVEL WIND FIELDS INCREASE. WARMEST TEMPERATURES MIGHT END UP BEING ACROSS WARREN COUNTY. DID NOT UP TEMPS MUCH FOR FRIDAY...MODELS MOVE COLD FRONT ACROSS THE AREA RATHER FAST. SOME CHANCE OF A STRONG THUNDERSTORM ACROSS THE WEST LATER FRIDAY. THIS BASED ON TIMING AND THE THERMAL RIDGE OVER THE BEST MOISTURE. HAVE TO WATCH FOR SEVERE...BUT DYNAMICS LIKELY TO LIFT NE AWAY FROM THE AREA. ALSO TIMING NOT THE BEST. WHILE WE WILL SEE SOME SHOWERS EACH DAY THIS WEEK...NOT SEEING ANY LARGE AMTS. THUS NOT SEEING ANY WIDESPREAD HYDRO CONCERNS AT THIS POINT. ENJOY THE MILDER TEMPERATURES. RATHER STRONG SMALL UPPER LEVEL TROUGH FOR LATE FRIDAY INTO SAT. TOOK OUT SHOWERS AFTER EARLY FRIDAY EVENING. MAIN THING WAS TO LOWER TEMPS FOR FRIDAY NIGHT INTO SAT...GIVEN AIRMASS TO THE NORTH AND COLD ADVECTION. WEEKEND SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID PUT SOME SHOWERS IN THE FAR WEST LATE MONDAY AND ACROSS THE AREA ON TUE. MODELS SHOW ANOTHER COLD FRONT MOVING IN. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... WIDESPREAD IFR/MVFR WILL CONTINUE NORTH OF THE FRONTAL SYSTEM THAT IS STALLED SOUTH OF PA. THIS STATIONARY FRONTAL BOUNDARY WILL KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT AND THURSDAY. AREAS OF DRIZZLE WITH SCATTERED SHOWERS WILL BE THE RULE WITH LITTLE IF ANY IMPROVEMENT EXPECTED. WINDS WILL REMAIN FROM THE EAST OR SOUTHEAST AT 5-10 MPH THROUGH THE PERIOD. OUTLOOK... FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. SAT-MON...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/MARTIN AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
758 AM EDT WED APR 8 2015 .SYNOPSIS... A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA WILL COMBINE WITH STRONG HIGH PRESSURE OVER QUEBEC CANADA...TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH THURSDAY WITH PERIODS OF RAIN AND DRIZZLE...AND A GENERALLY LIGHT EAST TO NORTHEAST WIND. DEEPENING LOW PRESSURE MOVING NORTHEAST ACROSS THE UPPER GREAT LAKES THURSDAY NIGHT WILL PUSH ITS TRAILING COLD FRONT ACROSS PENNSYLVANIA DURING THE MIDDAY AND AFTERNOON HOURS FRIDAY. MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY...WITH EVEN A FEW SNOW SHOWERS POSSIBLE ACROSS THE NORTHWEST MOUNTAINS SATURDAY MORNING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE EARLIER LULL IN THE RAIN SHOWERS IS COMING TO AN END AS A COMPACT AND QUITE FLAT UPPER SHORT WAVE SLIDES EAST OF THE PENN/OHIO BORDER. WEAK LLVL RIDGING THROUGH THE SUSQ VALLEY AND SCENT MTNS WILL CONTINUE THE RELATIVE MIN IN SHOWERS THERE FOR THE NEXT 1-2 HOURS. 05Z HRRR WAS BLENDED IN TO POPULATE NEAR TERM POPS/WEATHER AND QPF GRIDS THROUGH THIS AFTERNOON. THIS DATA SHOWS A STEADY PROGRESSION OF SHOWERS ACROSS CENTRAL PENN DURING THE MID TO LATER MORNING HOURS...FOLLOWED BY A DISTINCT LULL IN THE PRECIP THIS AFTERNOON WITH WIDESPREAD STRATUS REMAINING AND JUST A FEW ISOLATED SHOWERS OR SOME PATCHY DRIZZLE POSSIBLE. CONSIDERING THE TIGHT TEMP/DWPT SPREAD OF GENERALLY 1-2 DEG F ACROSS THE CENTRAL AND WESTERN ZONES...TEMPS ARE RIGHT NEAR THEIR MINS. A SLIGHTLY GREATER T/TD SPREAD ACROSS THE SUSQ VALLEY WILL ALLOW FOR A 2-4 DEG F TEMP DROP BETWEEN 10-12Z AS THE INCREASING COVERAGE OF SHOWERS SPREADS EWD INTO THAT AREA. HIGH TEMPS THIS AFTERNOON WILL BE MUCH COOLER THAN TUESDAY...RANGING FROM AROUND 40 DEG ACROSS THE HIGHER TERRAIN OF THE WRN POCONOS AND ENDLESS MTNS NW OF KIPT...TO THE MID 50S ON THE WRN SIDE OF THE ATLANTIC/GOMEX WATER SHED BOUNDARY /NEAR THE RT 219 CORRIDOR/. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... CLOUDY...COOL AND DAMP CONDITIONS WILL CONTINUE TONIGHT AS HIGH PRESSURE OVER QUEBEC CANADA RIDGES SWWD INTO THE STATE ACCOMPANIED BY A LIGHT EAST TO NE BREEZE. AT THE SAME TIME...MEAN TEMPS IN THE 900-850 MB LAYER WILL INCREASE BY ABOUT 2-3 DEG C /BETWEEN 00Z-12Z THU/. THIS SHOULD LEAD TO RIDGE SHROUDING FOG ACROSS MUCH OF THE REGION WITH THE LOWEST VSBYS ON THE EAST-FACING UPPER SLOPES. ANOTHER FLAT SHORTWAVE /OR MCV FROM WEAKENING UPSTREAM TSRA/ APPEARS TO MOVE EAST FROM THE OHIO VALLEY AND TARGET MUCH OF THE REGION OVERNIGHT TONIGHT. CAN/T RULE OUT A FEW TSRA ACROSS OUR WESTERN ZONES LATE TODAY/THIS EVENING...NEAR THE EASTERN EDGE OF WEAK-MDT LEVELS OF MLCAPE OF 500-1000 J/KG. ELSEWHERE...A FEW SHOWERS WILL BE LIKELY WITH BASIN AVG RAINFALL AMOUNTS AROUND 0.10 OF AN INCH /PERHAPS A FEW TENTHS HIGHER THOUGH ACROSS THE LAURELS - CLOSER TO THE WEAKENING TSRA/. TEMPS TONIGHT COULD DIP OR STAY 3-5F COOLER THAN MOST GUIDANCE AS VERY SHALLOW AND ANOMALOUSLY COOL NEAR SFC AIR WILL BE FUNNELED SWWD FROM THE NEW ENGLAND STATES AND HUDSON VALLEY. APPROX 03Z SREF GUIDANCE WAS USED FOR TONIGHT/S MINS...WHICH SUPPORT A LOW PROBABILITY FOR -FZRA/-FZDZ ACROSS THE WRN POCONOS AND ENDLESS MTNS REGION NE OF KIPT. LOWS TONIGHT RANGE FROM THE LOWER 30S ACROSS THE ERN HIGH TERRAIN...TO THE MID AND UPPER 40S WEST OF RT 219 IN WRN PENN. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... WARMER AIR WILL WORK INTO THE AREA LATE THU INTO FRIDAY...AS LOW LEVEL WIND FIELDS INCREASE. WARMEST TEMPERATURES MIGHT END UP BEING ACROSS WARREN COUNTY. DID NOT UP TEMPS MUCH FOR FRIDAY...MODELS MOVE COLD FRONT ACROSS THE AREA RATHER FAST. SOME CHANCE OF A STRONG THUNDERSTORM ACROSS THE WEST LATER FRIDAY. THIS BASED ON TIMING AND THE THERMAL RIDGE OVER THE BEST MOISTURE. HAVE TO WATCH FOR SEVERE...BUT DYNAMICS LIKELY TO LIFT NE AWAY FROM THE AREA. ALSO TIMING NOT THE BEST. WHILE WE WILL SEE SOME SHOWERS EACH DAY THIS WEEK...NOT SEEING ANY LARGE AMTS. THUS NOT SEEING ANY WIDESPREAD HYDRO CONCERNS AT THIS POINT. ENJOY THE MILDER TEMPERATURES. RATHER STRONG SMALL UPPER LEVEL TROUGH FOR LATE FRIDAY INTO SAT. TOOK OUT SHOWERS AFTER EARLY FRIDAY EVENING. MAIN THING WAS TO LOWER TEMPS FOR FRIDAY NIGHT INTO SAT...GIVEN AIRMASS TO THE NORTH AND COLD ADVECTION. WEEKEND SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID PUT SOME SHOWERS IN THE FAR WEST LATE MONDAY AND ACROSS THE AREA ON TUE. MODELS SHOW ANOTHER COLD FRONT MOVING IN. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... SHORTWAVE SLIDING OVERHEAD THIS MORNING GENERATING AN AREA OF SHOWERS THAT WILL CONTINUE TO PROGRESS ACROSS CENTRAL PA...REACHING THE LOWER SUSQ AROUND 14Z. THESE WILL END FROM THE WEST BY MID MORNING IN THE NORTHERN/CENTRAL MTNS AND BY 18Z IN THE LOWER SUSQ...WITH JUST SOME DRIZZLE LIKELY THIS AFT. WIDESPREAD IFR CIG RESTRICTIONS ONGOING WILL PERSIST FOR MUCH OF THE DAY AND THROUGH TONIGHT...THOUGH COULD SEE CIGS LIFT ABOVE 1000FT IN THE EAST FOR SEVERAL HOURS THIS AFT. VSBYS VARIABLE...BUT MOVING FROM GENERALLY MVFR TO MORE WIDESPREAD VFR LATER THIS MORNING. STATIONARY FRONTAL BOUNDARY OFF TO OUR SW WILL KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT...AS CONDITIONS SETTLE BACK INTO WIDESPREAD IFR. AREAS OF DRIZZLE WILL BE AROUND...WITH RAIN SLIPPING INTO WESTERN SECTIONS OVERNIGHT. WINDS WILL REMAIN FROM THE EAST AT 5-10 MPH THROUGH THE PERIOD. OUTLOOK... WED...WIDESPREAD MVFR/IFR IN SHRA/PERIODS OF RA. THU...REDUCTIONS LIKELY IN SCT SHRA. FRI...REDUCTIONS LIKELY IN SHRA...ESPECIALLY DURING THE AFT. CHC OF THUNDER AFT. SAT-SUN...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/MARTIN AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
528 AM EDT WED APR 8 2015 .SYNOPSIS... A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA WILL COMBINE WITH STRONG HIGH PRESSURE OVER QUEBEC CANADA...TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH THURSDAY WITH PERIODS OF RAIN AND DRIZZLE...AND A GENERALLY LIGHT EAST TO NORTHEAST WIND. DEEPENING LOW PRESSURE MOVING NORTHEAST ACROSS THE UPPER GREAT LAKES THURSDAY NIGHT WILL PUSH ITS TRAILING COLD FRONT ACROSS PENNSYLVANIA DURING THE MIDDAY AND AFTERNOON HOURS FRIDAY. MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY...WITH EVEN A FEW SNOW SHOWERS POSSIBLE ACROSS THE NORTHWEST MOUNTAINS SATURDAY MORNING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE EARLIER LULL IN THE RAIN SHOWERS IS COMING TO AN END AS A COMPACT AND QUITE FLAT UPPER SHORT WAVE SLIDES EAST OF THE PENN/OHIO BORDER. WEAK LLVL RIDGING THROUGH THE SUSQ VALLEY AND SCENT MTNS WILL CONTINUE THE RELATIVE MIN IN SHOWERS THERE FOR THE NEXT 1-2 HOURS. 05Z HRRR WAS BLENDED IN TO POPULATE NEAR TERM POPS/WEATHER AND QPF GRIDS THROUGH THIS AFTERNOON. THIS DATA SHOWS A STEADY PROGRESSION OF SHOWERS ACROSS CENTRAL PENN DURING THE MID TO LATER MORNING HOURS...FOLLOWED BY A DISTINCT LULL IN THE PRECIP THIS AFTERNOON WITH WIDESPREAD STRATUS REMAINING AND JUST A FEW ISOLATED SHOWERS OR SOME PATCHY DRIZZLE POSSIBLE. CONSIDERING THE TIGHT TEMP/DWPT SPREAD OF GENERALLY 1-2 DEG F ACROSS THE CENTRAL AND WESTERN ZONES...TEMPS ARE RIGHT NEAR THEIR MINS. A SLIGHTLY GREATER T/TD SPREAD ACROSS THE SUSQ VALLEY WILL ALLOW FOR A 2-4 DEG F TEMP DROP BETWEEN 10-12Z AS THE INCREASING COVERAGE OF SHOWERS SPREADS EWD INTO THAT AREA. HIGH TEMPS THIS AFTERNOON WILL BE MUCH COOLER THAN TUESDAY...RANGING FROM AROUND 40 DEG ACROSS THE HIGHER TERRAIN OF THE WRN POCONOS AND ENDLESS MTNS NW OF KIPT...TO THE MID 50S ON THE WRN SIDE OF THE ATLANTIC/GOMEX WATER SHED BOUNDARY /NEAR THE RT 219 CORRIDOR/. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... CLOUDY...COOL AND DAMP CONDITIONS WILL CONTINUE TONIGHT AS HIGH PRESSURE OVER QUEBEC CANADA RIDGES SWWD INTO THE STATE ACCOMPANIED BY A LIGHT EAST TO NE BREEZE. AT THE SAME TIME...MEAN TEMPS IN THE 900-850 MB LAYER WILL INCREASE BY ABOUT 2-3 DEG C /BETWEEN 00Z-12Z THU/. THIS SHOULD LEAD TO RIDGE SHROUDING FOG ACROSS MUCH OF THE REGION WITH THE LOWEST VSBYS ON THE EAST-FACING UPPER SLOPES. ANOTHER FLAT SHORTWAVE /OR MCV FROM WEAKENING UPSTREAM TSRA/ APPEARS TO MOVE EAST FROM THE OHIO VALLEY AND TARGET MUCH OF THE REGION OVERNIGHT TONIGHT. CAN/T RULE OUT A FEW TSRA ACROSS OUR WESTERN ZONES LATE TODAY/THIS EVENING...NEAR THE EASTERN EDGE OF WEAK-MDT LEVELS OF MLCAPE OF 500-1000 J/KG. ELSEWHERE...A FEW SHOWERS WILL BE LIKELY WITH BASIN AVG RAINFALL AMOUNTS AROUND 0.10 OF AN INCH /PERHAPS A FEW TENTHS HIGHER THOUGH ACROSS THE LAURELS - CLOSER TO THE WEAKENING TSRA/. TEMPS TONIGHT COULD DIP OR STAY 3-5F COOLER THAN MOST GUIDANCE AS VERY SHALLOW AND ANOMALOUSLY COOL NEAR SFC AIR WILL BE FUNNELED SWWD FROM THE NEW ENGLAND STATES AND HUDSON VALLEY. APPROX 03Z SREF GUIDANCE WAS USED FOR TONIGHT/S MINS...WHICH SUPPORT A LOW PROBABILITY FOR -FZRA/-FZDZ ACROSS THE WRN POCONOS AND ENDLESS MTNS REGION NE OF KIPT. LOWS TONIGHT RANGE FROM THE LOWER 30S ACROSS THE ERN HIGH TERRAIN...TO THE MID AND UPPER 40S WEST OF RT 219 IN WRN PENN. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... WARMER AIR WILL WORK INTO THE AREA LATE THU INTO FRIDAY...AS LOW LEVEL WIND FIELDS INCREASE. WARMEST TEMPERATURES MIGHT END UP BEING ACROSS WARREN COUNTY. DID NOT UP TEMPS MUCH FOR FRIDAY...MODELS MOVE COLD FRONT ACROSS THE AREA RATHER FAST. SOME CHANCE OF A STRONG THUNDERSTORM ACROSS THE WEST LATER FRIDAY. THIS BASED ON TIMING AND THE THERMAL RIDGE OVER THE BEST MOISTURE. HAVE TO WATCH FOR SEVERE...BUT DYNAMICS LIKELY TO LIFT NE AWAY FROM THE AREA. ALSO TIMING NOT THE BEST. WHILE WE WILL SEE SOME SHOWERS EACH DAY THIS WEEK...NOT SEEING ANY LARGE AMTS. THUS NOT SEEING ANY WIDESPREAD HYDRO CONCERNS AT THIS POINT. ENJOY THE MILDER TEMPERATURES. RATHER STRONG SMALL UPPER LEVEL TROUGH FOR LATE FRIDAY INTO SAT. TOOK OUT SHOWERS AFTER EARLY FRIDAY EVENING. MAIN THING WAS TO LOWER TEMPS FOR FRIDAY NIGHT INTO SAT...GIVEN AIRMASS TO THE NORTH AND COLD ADVECTION. WEEKEND SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID PUT SOME SHOWERS IN THE FAR WEST LATE MONDAY AND ACROSS THE AREA ON TUE. MODELS SHOW ANOTHER COLD FRONT MOVING IN. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... LOW CIGS AND FOG WILL SUPPORT REDUCED FLYING CONDS ACROSS THE ENTIRE AIRSPACE OVER NIGHT..WIDESPREAD MVFR AND IFR OR LOWER ACROSS HIGHER ELEVATIONS. CONDS CAUSED BY FRONTAL BOUNDARY VCNTY STATE AND ABUNDANT LOW LEVEL MOISTURE FROM ONGOING SHOWERS AND THOSE FROM EARLIER TODAY. WINDS WILL REMAIN LIGHT INTO WED. OUTLOOK... WED...WIDESPREAD MVFR/IFR IN SHRA/PERIODS OF RA. THU...REDUCTIONS LIKELY IN SCT SHRA. FRI...REDUCTIONS LIKELY IN SHRA...ESPECIALLY DURING THE AFT. CHC OF THUNDER AFT. SAT-SUN...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...MARTIN AVIATION...DEVOIR/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
201 AM EDT WED APR 8 2015 .SYNOPSIS... A STATIONARY FRONTAL BOUNDARY WILL REMAIN DRAPED FROM NORTHERN VIRGINIA TO CENTRAL OHIO TODAY...BEFORE MOVING NORTHEAST ACROSS PENNSYLVANIA AS A WARM FRONT ON THURSDAY. HIGH PRESSURE OVER THE CANADIAN MARITIMES WILL SUPPLY A NORTHEAST FLOW OF COOL...MOIST AIR INTO THE REGION TODAY...HELPING TO CREATE AREAS OF RAIN AND DRIZZLE. A DEEP STORM SYSTEM WILL TRACK NORTHEAST ACROSS THE GREAT LAKES ON FRIDAY...DRAGGING A TRAILING COLD FRONT THROUGH PENNSYLVANIA. && .NEAR TERM /UNTIL 9 AM THIS MORNING/... REGIONAL RADAR MOSAIC AND LATEST...04Z HRRR INDICATE THAT THE BEST CHANCE FOR RAIN THROUGH THE MID MORNING HOURS WILL BE ACROSS THE NRN MTNS AND LAUREL HIGHLANDS OF SWRN PENN...CLOSE TO THE STATIONARY FRONT NEAR THE MASON-DIXON LINE...AND AN INVERTED TROUGH NEAR THE SOUTH SHORE OF LAKE ERIE. WEAK LLVL RIDGING THROUGH THE SUSQ VALLEY AND CENT MTNS WILL CONTINUE THE RELATIVE MIN IN SHOWERS THERE. CONSIDERING THE TIGHT TEMP/DWPT SPREAD OF GENERALLY 2 DEG F OR LESS...TEMPS WILL ONLY FALL ANOTHER DEG OR SO BY DAYBREAK...WITH MINS RANGING FROM THE U30S ACROSS THE NRN AND ERN MTNS...TO THE UPPER 40S IN OUR SWRN ZONES. && .SHORT TERM /9 AM THIS MORNING THROUGH 6 PM THURSDAY/... COOL AND DANK CONDITIONS WILL BE THE NORM TODAY IN LLVL CAD REGIME WITH PLENTY OF LLVL MOISTURE AND OVERRUNNING ZONAL FLOW ALOFT PROMOTING LIGHT SHOWERS ESPECIALLY IN THE AFTERNOON. HIGHS WILL RANGE THROUGH THE 40S FOR MOST...BUT AREAS ALONG THE ALLEGHENY FRONT MAY NUDGE INTO THE WARM SECTOR WITH WESTERN WARREN AND WESTERN SOMERSET COUNTIES REACHING INTO THE 50S /AND PERHAPS NEAR 60 ACROSS SOUTHWEST SOMERSET COUNTY/. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... DID NOT CHANGE POPS OR WEATHER FOR TONIGHT...GIVEN SLIGHT CHANCE FOR A LITTLE FREEZING DRIZZLE OR RAIN ACROSS THE NE. LOWS NEAR HUDSON AND JAMES BAY AREA WERE ZERO TO 20 BELOW THIS MORNING. THAT IS VERY COLD FOR EARLY APRIL. DETAILS BELOW... GIVEN THE FACT THAT WE/LL HAVE A 1040 MB SFC HIGH BECOMING PARKED ACROSS SRN QUEBEC /WHERE CURRENT TEMPS ARE IN THE SINGLE DIGITS TO TEENS/ AND 1000 MB AGEOSTROPHIC FLOW INCREASING FROM THE NORTH-NORTHEAST /AND STAYING THERE FOR A 24-36 HOUR PERIOD/...WENT SEVERAL DEG F BELOW MODEL TEMPS FOR WED MAXES AND WED NIGHT MINS. EVEN MENTIONED A SLIGHT CHC FOR LIGHT FZRA ACROSS PARTS OF THE NCENT MTNS AND WRN POCONOS LATE WED NIGHT AND EARLY THURSDAY. THIS LLVL COLD AIR DAMMING LIKELY TO LINGER INTO THURSDAY AFT. SOME NEW DETAIL BELOW... WHILE TEMPS MAY NOT WARM UP TO A GREAT EXTENT THU...AND I LEFT THEM CLOSE TO WHAT WE HAD...WILL CONTINUE TO MONITOR. VERY TIGHT TEMPERATURE GRADIENT AT 850 MB LATE WED EVENING ACROSS CENTRAL NY...MINUS 4 TO PLUS 10 IN ABOUT 80 TO 100 MILE BAND. ANYWAY...WARMER AIR WILL WORK INTO THE AREA LATE THU INTO FRIDAY...AS LOW LEVEL WIND FIELDS INCREASE. WARMEST TEMPERATURES MIGHT END UP BEING ACROSS WARREN COUNTY. DID NOT UP TEMPS MUCH FOR FRIDAY...MODELS MOVE COLD FRONT ACROSS THE AREA RATHER FAST. SOME CHANCE OF A STRONG THUNDERSTORM ACROSS THE WEST LATER FRIDAY. THIS BASED ON TIMING AND THE THERMAL RIDGE OVER THE BEST MOISTURE. HAVE TO WATCH FOR SEVERE...BUT DYNAMICS LIKELY TO LIFT NE AWAY FROM THE AREA. ALSO TIMING NOT THE BEST. WHILE WE WILL SEE SOME SHOWERS EACH DAY THIS WEEK...NOT SEEING ANY LARGE AMTS. THUS NOT SEEING ANY WIDESPREAD HYDRO CONCERNS AT THIS POINT. ENJOY THE MILDER TEMPERATURES. RATHER STRONG SMALL UPPER LEVEL TROUGH FOR LATE FRIDAY INTO SAT. TOOK OUT SHOWERS AFTER EARLY FRIDAY EVENING. MAIN THING WAS TO LOWER TEMPS FOR FRIDAY NIGHT INTO SAT...GIVEN AIRMASS TO THE NORTH AND COLD ADVECTION. WEEKEND SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID PUT SOME SHOWERS IN THE FAR WEST LATE MONDAY AND ACROSS THE AREA ON TUE. MODELS SHOW ANOTHER COLD FRONT MOVING IN. && .AVIATION /05Z WEDNESDAY THROUGH SUNDAY/... LOW CIGS AND FOG WILL SUPPORT REDUCED FLYING CONDS ACROSS THE ENTIRE AIRSPACE OVER NIGHT..WIDESPREAD MVFR AND IFR OR LOWER ACROSS HIGHER ELEVATIONS. CONDS CAUSED BY FRONTAL BOUNDARY VCNTY STATE AND ABUNDANT LOW LEVEL MOISTURE FROM ONGOING SHOWERS AND THOSE FROM EARLIER TODAY. WINDS WILL REMAIN LIGHT INTO WED. OUTLOOK... WED...WIDESPREAD MVFR/IFR IN SHRA/PERIODS OF RA. THU...REDUCTIONS LIKELY IN SCT SHRA. FRI...REDUCTIONS LIKELY IN SHRA...ESPECIALLY DURING THE AFT. CHC OF THUNDER AFT. SAT-SUN...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT/FITZGERALD NEAR TERM...LAMBERT SHORT TERM...LAMBERT/DEVOIR LONG TERM...LAMBERT/MARTIN AVIATION...DEVOIR/GARTNER
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
511 PM EDT WED APR 8 2015 .SYNOPSIS... M AND HUMID SOUTHWESTERLY FLOW WILL PERSIST OVER THE REGION THROUGH THE WORK WEEK...KEEPING CONDITIONS UNSETTLED WITH CHANCES FOR SHOWERS AND THUNDERSTORMS EACH DAY. A COLD FRONT IS FORECAST TO CROSS THE REGION BY THE END OF FRIDAY...LIKELY SUPPORTING A BAND OF SHOWER AND THUNDERSTORMS. DRIER WEATHER IS EXPECTED TO RETURN TO THE REGION THIS WEEKEND. && .NEAR TERM /THROUGH THURSDAY/... AS OF 500 PM EDT...THE ATMOS CONTINUES TO BE RATHER SUPPRESSED ACRS THE CWFA...AS AS UPPER RIDGING DOMINATES. HAVE CUT BACK POP HEADING INTO THE EVENING HOURS...IN LINE WITH THE LAST FEW HRRR RUNS OF SIMULATED REFLECTIVITY. MCS ACTIVITY LOOKS TO REMAIN NORTH OF THE AREA. HOWEVER...ONE CLUSTER OF STORMS OVER CENTRAL KY MAY DROP SE IN TO THE NC MTNS LATE THIS EVENING (PER THE CONVECTION ALLOWING MODELS). SO WILL LEAVE THE CHC POP ACRS THE NRN TIER FOR LATE EVENING INTO OVERNIGHT. THE UPSTATE AND NE GA MAY NOT SEE ANY PRECIP...IF THE LATEST TRENDS HOLD. AS OF 230 PM EDT...WEAK UPPER RIDGING CONTINUES TO STRENGTHEN DOWN THE EASTERN SEABOARD IN RESPONSE TO A DIGGING UPPER TROUGH ACROSS THE ROCKIES. STRONG SHORTWAVE CROSSING THE FLOW ACROSS THE CENTRAL APPALACHIANS IS RESULTING IN A FAIRLY SIGNIFICANT CONVECTIVE COMPLEX MOVING INTO WEST VIRGINIA AT AFD TIME. HI-RES REFLECTIVITY GUIDANCE WANTS TO CONTINUE TO DRAG THIS COMPLEX SOUTHEAST ALONG THE NORTHWEST FLOW ALOFT...CLIPPING THE NORTHERN PORTION OF OUR FORECAST AREA. SBCAPE VALUES EAST OF THE RIDGES CONTINUE TO INCREASE AND ARE UP TO BETWEEN 1000-1500 J/KG AT AFD TIME AND LOOK TO SUPPORT THE SUSTAINING OF THIS COMPLEX. ADDITIONALLY...WITH THE INCREASING SBCAPE VALUES...CANNOT RULE OUT AT LEAST ISOLATED CONVECTION ELSEWHERE ACROSS THE AREA THIS AFTERNOON AND EVENING AS THE LOW LEVEL CAP ERODES. BUFR SOUNDINGS MAX OUT BETWEEN 1500-2000 J/KG AT VARIOUS LOCATIONS ACROSS THE FORECAST AREA AND WITH SLIGHTLY STEEPER LAPSE RATES THAN YESTERDAY...CERTAINLY CANNOT RULE OUT ISOLATED SEVERE THOUGH BEST CHANCES REMAIN ACROSS EXTREME NORTHERN ZONES CLOSER TO THE UPPER SHORTWAVE. THREATS SIMILAR TO YESTERDAY WITH LARGE HAIL AND DAMAGING WINDS. UPPER RIDGING WILL CONTINUE TO INCREASE OVERNIGHT BUT COULD STILL SEE ANOTHER ROUND OF LOW CLOUDS AND LIGHT FOG THURSDAY MORNING. THE ROCKIES UPPER WAVE WILL PUSH INTO THE PLAINS DURING THE DAY ON THURSDAY...DRAGGING A FRONT THROUGH THE MID MISSISSIPPI VALLEY. WE REMAIN SOLIDLY IN THE WARM SECTOR ACROSS THE SOUTHEAST WITH BOTH GFS AND NAM INCREASING CAPES ACROSS ESPECIALLY THE PIEDMONT TO BETWEEN 1500-2000 J/KG AGAIN. NO REAL DEEP LAYER BULK SHEAR TO SPEAK OF...TOO FAR AHEAD OF THE UPPER SYSTEM...BUT THERE IS ENOUGH TURNING IN THE WIND PROFILE WITH THE SOUTHERLY WINDS AT THE SURFACE AND WEST TO SOUTHWESTERLY WINDS ALOFT TO RESULT IN SOME DECENT HELICITY VALUES THAT MAY HELP TO ORGANIZE CONVECTION THURSDAY AFTERNOON INTO EVENING. CURRENT SPC DAY2 OUTLOOK ONLY HAS OUR AREA IN GENERAL THUNDER BUT WOULD NOT BE SURPRISED TO AGAIN SEE ISOLATED SEVERE POTENTIAL. POPS THROUGH THE NEAR TERM CONTINUE TO FOLLOW A GENERAL DIURNAL TREND BUT HIGHER POPS ARE EMPHASIZED ACROSS NORTHERN ZONES CLOSER TO ANY SHORTWAVE ACTIVITY. TEMPERATURES REMAIN WARM UNDER THE INCREASING THICKNESSES ALOFT... WITH LOWS TONIGHT A GOOD 10-15 DEGREES ABOVE NORMAL AND HIGHS THURSDAY 10 OR SO DEGREES ABOVE SEASONAL NORMALS. GUIDANCE OVERALL IN FAIRLY GOOD AGREEMENT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... AS OF 215 PM WEDNESDAY...THE MAIN FOCUS FOR THE SHORT TERM CONTINUES TO BE THE POTENTIAL FOR SEVERE THUNDERSTORMS AHEAD/ALONG A COLD FRONT MAINLY IN THE AFTERNOON. BUT BEFORE WE GET THERE...WE WILL STILL HAVE TO DEAL WITH A CHANCE OF THUNDERSTORMS...PERHAPS A FEW STRONG TO SEVERE...ON THURSDAY EVENING. THE WHOLE FCST AREA WARRANTS A CHANCE POP INTO THURSDAY EVENING...BUT LOSS OF DAYTIME HEATING SHOULD REDUCE THE CHANCES BACK TO WHERE SOME MECHANICAL FORCING REMAINS IN THE VICINITY OF THE BLUE RIDGE BY LATE EVENING. THE PRECIP CHANCES THEN START RAMPING UP ON THE TN BORDER AFTER MIDNIGHT AS CONVECTION ALONG A PRE-FRONTAL TROF MAY REACH THE NC MTNS BEFORE DAYBREAK. EXPECT AREAS E OF THE MTNS TO GET A BREAK IN THE ACTION AROUND SUNRISE FRIDAY...WHICH RESULTS IN A SHORT PERIOD WITH A LARGE POP GRADIENT FROM W TO E. TEMPS SHOULD BE SEASONALLY MILD OVERNIGHT. WHICH BRINGS US TO FRIDAY. THE MODELS SHOW EXCELLENT FORCING ALONG THE FRONT TO THE WEST DURING THE EARLY MORNING HOURS...BUT THIS WEAKENS AS IT CROSSES THE WESTERN CAROLINAS. THE RECENT MODEL TREND SHOWING POORER CONVERGENCE ACROSS THE FRONT ALSO CONTINUES ON THE NEW RUNS. THE CORE OF THE LOW LEVEL JET PULLS NWD BY AFTERNOON AND 850 MB WINDS WEAKEN AND VEER. THE RESULT IS SOMEWHAT WEAKER SHEAR AND A MORE UNIDIRECTIONAL HODOGRAPH. ON THE OTHER HAND...A SLIGHT DELAY IN THE TIMING ALLOWS SURFACE BASED CAPE IN THE MODELS TO CLIMB A BIT HIGHER...CLOSER TO 1000 J/KG ON THE GFS AND ABOVE 1500 J/KG ON THE OPERATIONAL NAM. SO...THE TREND ON THE SIGNALS IS MIXED. STILL THINK WE HAVE A DECENT CHANCE FOR ORGANIZED SEVERE CONVECTION... ESPECIALLY E OF THE MTNS...SO WE WILL CONTINUE TO MENTION IT IN THE HWO. THE PRECIP PROBABILITY GOES UP TO CATEGORICAL ON THE TN BORDER...BUT HAVE KEPT ONLY A LIKELY E OF THE MTNS BECAUSE IT IS POSSIBLE THAT A CONVECTIVE LINE COULD BREAK UP A BIT OVER THE MTNS AND THEN FILL BACK IN AS IT IS LEAVING THE EASTERN PART OF THE FCST AREA LATE IN THE DAY. THE CONVECTION SHOULD PUSH E OF THE REGION IN THE EARLY EVENING EVEN IF THE FRONT GETS HELD UP ON THE MTNS. PRECIP CHANCES RAMP DOWN FROM THE WEST WITH FRONTAL PASSAGE. ON SATURDAY...A NRN STREAM TROF PASSING TO THE WEST WILL RESULT IN A NEARLY ZONAL FLOW ACROSS THE SOUTHEAST. HIGH PRESSURE SHOULD BUILD IN TO DRY US OUT AND GIVE US A NORMAL SPRING DAY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 215 PM WED...GUIDANCE IN GENERAL AGREEMENT WITH SHORT WAVE RIDGING SETTING UP FOR SUNDAY AND MONDAY AS A SRN STREAM UPPER LOW DEVELOPS AND MOVES INTO THE SRN PLAINS. AHEAD OF THIS SYSTEM...A DAMPENING SHORT WAVE TOPS THE RIDGE AND CROSSES THE AREA TUE AS THE UPPER LOW WEAKENS AND MOVES INTO THE GREAT LAKES. RIDGING BEGINS TO REBUILD ON WED...BUT SWLY FLOW ALOFT REMAINS OVER OUR AREA WITH WEAK SHORT WAVES MOVING THRU THE FLOW. AT THE SFC...DRY AND MILD HIGH PRESSURE MOVES IN ON SUN...WITH POTENTIALLY ENUF LINGERING MOISTURE FOR ISOLATES SHOWERS ACROSS THE MTNS. TEMPS WILL BE UP TO 5 DEGREES ABOVE NORMAL. THE HIGH MOVES EAST MON WITH SLY RETURN FLOW DEVELOPING. WITHOUT ANY STRONG FORCING DEVELOPING...EXPECT SCT SHRA ACROSS THE MTNS AND ISOLATED SHRA ELSEWHERE. TEMPS 5 TO 10 DEGREES ABOVE NORMAL. THE SLY RETURN FLOW REMAINS IN PLACE TUE AND WED WITH WEAK SFC RIDGING OVER THE AREA AND ANY FRONTAL SYSTEMS WELL TO OUR NORTH. THIS WILL CREATE SCT MAINLY DIURNAL CONVECTION BOTH DAYS. LOWS WILL BE UP TO 15 DEGREES ABOVE NORMAL WITH HIGHS AROUND 10 DEGREES ABOVE NORMAL. && .AVIATION /21Z WEDNESDAY THROUGH MONDAY/... AT KCLT...STUBBORN MVFR CIGS ARE BEGINNING TO LIFT AND SCATTER AND EXPECT VFR CONDITIONS THIS AFTERNOON WITH SW WINDS GENERALLY REMAINING 7KT OR LESS. AN UPPER LEVEL DISTURBANCE PASSES TO THE NORTH OF THE AREA LATE THIS AFTERNOON AND EVENING AND HAVE INTRODUCED TEMPO TSRA FROM 23-03Z TO ACCOUNT FOR PROXIMITY...BUT IT IS VERY POSSIBLE THAT ALL TSRA WILL STAY NORTH OF KCLT. AS THE DISTURBANCE APPROACHES...WINDS WILL BACK MORE TO THE S WITH SPEEDS DECREASING. POTENTIAL FOR RESTRICTED VSBYS/CIGS THURSDAY MORNING HIGHLY DEPENDENT ON COVERAGE OF CONVECTION LATER TODAY BUT OVERALL CANNOT RULE OUT A REPEAT OF THIS MORNING. HAVE BROUGHT IN MVFR VSBY BUT ONLY SCT IFR CLOUDS FOR NOW. IMPROVING CONDITIONS AFTER SUNRISE THURSDAY. ELSEWHERE...VERY SIMILAR TO KCLT OVERALL. KHKY HAS THE BEST CHANCE OF LATE AFTERNOON/EVENING CONVECTION WITH KAND THE LEAST...OPTED TO NOT INTRODUCE TEMPO TSRA AT KAND FOR NOW. AS WITH KCLT...COULD SEE PATCHY IFR CIGS AND AT LEAST MVFR VSBY THURSDAY MORNING BUT OVERALL RESTRICTIONS WILL DEPEND HIGHLY ON COVERAGE OF EVENING CONVECTION. IMPROVING AFTER SUNRISE THURSDAY. OUTLOOK...EXPECT ANOTHER ROUND OF AFTERNOON CONVECTION THURSDAY AFTERNOON/EVENING...AND A COLD FRONT WILL PUSH THROUGH LATE FRIDAY ALSO WITH THE POTENTIAL FOR AT LEAST SCATTERED CONVECTION. WITH AFTERNOON CONVECTION WILL FOLLOW POTENTIAL FOR RESTRICTIONS EACH MORNING. MUCH IMPROVED CONDITIONS FOR THE WEEKEND AFTER THE FRONT CLEARS THE AREA. CONFIDENCE TABLE... 21-03Z 03-09Z 09-15Z 15-18Z KCLT HIGH 100% HIGH 94% HIGH 94% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 94% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 89% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 94% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...NED NEAR TERM...ARK/TDP SHORT TERM...PM LONG TERM...RWH AVIATION...TDP
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
346 PM CDT WED APR 8 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 346 PM CDT WED APR 8 2015 PERSISTENT LOW CLOUD EVENT EXPECTED TO CONTINUE ACROSS THE AREA TONIGHT INTO TOMORROW AS LOW LEVEL EASTERLY FLOW REINFORCES STRATUS ACROSS THE AREA. BAD OF 850 HPA THETA-E ADVECTION IS EXPECTED TO LIFT NORTH THROUGH THE LATE AFTERNOON INTO THE EVENING HOURS. STILL SOME QUESTION AS TO HOW CONVECTIVE ANY ACTIVITY MAY GET AS VERY STEEP LAPSE RATES EXIST FROM 700-300 MB ACROSS THE SOUTHEASTERN CWA. RAP SOUNDINGS SHOW SMALL WARM NOSE HOLDING...BUT NOT SURE AM READY TO BUY INTO THAT ENTIRELY SO HAVE HELD ON TO THE MENTION OF THUNDER THROUGH THE LATE AFTERNOON. WITH STEEP LAPSE RATES AND COLD ATMOSPHERE...CERTAINLY A GOOD CASE FOR HAIL IF A STORM CAN DEVELOP FROM THE ELEVATED WARM AIR AND MOISTURE ADVECTION. ISENTROPIC LIFT CONTINUES THROUGH THE OVERNIGHT THOUGH CONTINUE TO HAVE OFF AND ON SATURATION ISSUES ALOFT. THEREFORE...AM EXPECTING LIGHT RAIN OR DRIZZLE THROUGH THE EVENING HOURS...INCREASING AFTER MIDNIGHT AS THE DEFORMATION BAND APPROACHES FROM THE WEST. AS THE SURFACE COLD FRONT/INVERTED TROUGH MOVES THROUGH THE AREA...FLOW TURNS MORE NORTHERLY WITH WARM NOSE ALOFT COOLING. THERE IS THE POTENTIAL FOR A FEW FLAKES TO MIX IN WITH THE RAIN TOMORROW DURING THE DAY...ESPECIALLY IN THE HIGHER ELEVATIONS...BUT WITH THE WARM LAYER NEAR THE SURFACE REMAINING STEADY THROUGH THE DAY...AM NOT EXPECTING SNOW TO ACCUMULATE. HAVE LOWERED FORECAST HIGHS ACROSS THE EAST WITH PRECIPITATION LINGERING THROUGH MUCH OF THE DAY...WHILE SKIES SHOULD BEGIN TO CLEAR OUT IN CENTRAL SOUTH DAKOTA THROUGH THE AFTERNOON HOURS LEADING TO A LATE DAY RECOVERY. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 346 PM CDT WED APR 8 2015 COULD SEE A LITTLE PRECIP LINGERING IN OUR FAR EAST INTO THURSDAY EVENING...BUT OTHERWISE EXPECT GENERALLY DRY CONDITIONS TO PREVAIL THROUGH THE MIDDLE RANGE OF THE FORECAST AS MID LEVEL RIDGE MOVES ACROSS THE NORTHERN PLAINS. AS THE RIDGE AXIS SHIFTS EAST INTO IOWA AND MINNESOTA LATE SATURDAY/SATURDAY NIGHT...RETURN FLOW OF MOISTURE AND WEAK ELEVATED INSTABILITY COULD LEAD TO SOME ISOLATED SHOWERS OR THUNDERSTORMS. THIS CHANCE WILL LINGER IN THE EAST INTO SUNDAY AS THE MID LEVEL TROUGH AND ASSOCIATED SURFACE FRONT PUSH THROUGH THE AREA. TEMPERATURES WILL BE ON A WARMING TREND AGAIN...WITH MID 50S TO MID 60S EXPECTED FOR HIGHS ON FRIDAY...AND UPPER 60S TO MID 70S BY SATURDAY. THE MILD AIR WILL STICK AROUND THROUGH AT LEAST THE MIDDLE OF NEXT WEEK...THOUGH WITH THE DIVERGENCE IN MODEL SOLUTIONS BY TUESDAY AND WEDNESDAY...THERE IS SOME UNCERTAINTY ON JUST HOW WARM TEMPERATURES WILL BE. OPTED TO STICK FAIRLY CLOSE TO BROAD MODEL BLEND FOR NOW... WHICH KEEPS HIGHS IN THE MID 60S TO MID 70S AND LOWS IN THE 40S TO LOWER 50S. AS FAR AS PRECIP CHANCES...IT CURRENTLY LOOKS LIKE SUNDAY NIGHT TO MONDAY SHOULD BE FAIRLY DRY AS THE NORTHERN STREAM TROUGH SHIFTS TO THE EAST...AND WEAK RIDGING DEVELOPS AHEAD OF A SOUTHERN STREAM WAVE THAT IS FORECAST TO SWING INTO THE PLAINS FROM THE SOUTHERN ROCKIES MONDAY NIGHT. THIS WILL BRING A BIT MORE UNSETTLED WEATHER TO THE AREA MONDAY NIGHT/TUESDAY. GREATER UNCERTAINTY REGARDING THE CHANCE FOR PRECIP TUESDAY NIGHT/WEDNESDAY DUE TO AFOREMENTIONED DIVERGENCE IN MODEL SOLUTIONS. WITH LOW CONFIDENCE IN ANY ONE SOLUTION...WILL HANG ON TO SOME LOW 20-30 RANGE POPS FOR NOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1229 PM CDT WED APR 8 2015 PERSISTENT LOW LYING STRATUS SHOULD CONTINUE TO REMAIN ACROSS THE AREA THROUGH THE FORECAST PERIOD. COULD SEE PERIODS OF RAIN AND DRIZZLE...REDUCING VISIBILITY. WINDS ARE EXPECTED TO INCREASE OUT OF THE NORTH LATE IN THE PERIOD AS A COLD FRONT DROPS FROM NORTHWEST TO SOUTHEAST. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM... LONG TERM...JH AVIATION...
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
921 PM CDT THU APR 9 2015 .UPDATE... OVERNIGHT GRIDS ARE IN PRETTY GOOD SHAPE. BUMPED POPS IN THE WESTERN HALF. HRRR INDICATING SOME ACTIVITY MOVING UP FROM THE SOUTHWEST AND AHEAD OF THE MAIN FORCING. A COUPLE STORMS HAVE MOVED UP FROM NE MISSISSIPPI BUT HAVE WEAKENED AS THEY MOVED INTO THE CWA. AS MENTIONED IN THE MESOSCALE DISCUSSION OVERALL INTENSITY OF THE LINE BACK TO THE WEST IS EXPECTED TO DIMINISH AS IT MOVES EAST GIVEN SHORT TERM MODEL TRENDS. BUMPED HOURLY TEMPERATURES UP A COUPLE DEGREES IN THE NW OTHERWISE TEMPERATURES ARE OVERALL ON TRACK. REAGAN && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 10
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
949 PM EDT THU APR 9 2015 .DISCUSSION...SEVERE THUNDERSTORMS THAT DEVELOPED EARLY THIS EVENING ACROSS FAR NORTHEAST TENNESSEE HAS WEAKEND AND MOVED EAST OF THE AREA. A SQUALL LINE IS CURRENTLY NEAR THE MISSISSIPPI RIVER. MODELS SHOW STRONG UPPER FORCING WITH THE RIGHT ENTRANCE REGION OF THE JET MOVING ACROSS THE TENNESSEE VALLEY. THE DIRECT CIRCULATION WITH THE JET WILL ENHANCE THE FRONTO-GENETIC FORCING ALONG THE PRE-FRONTAL TROUGH. USING THE HRRR MODEL FOR TIMING...EXPECT STRONG STORMS TO GET INTO THE PLATEAU COUNTIES BETWEEN 06-08Z...WITH MAIN LINE BETWEEN 08-10Z. DAMAGING WINDS WILL BE THE MAIN CONCERN. MADE MINOR CHANGES TO TEMPERATURES AND POPS...OTHERWISE...CURRENT FORECAST LOOKS GOOD. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 66 72 51 75 / 80 80 10 0 KNOXVILLE MCGHEE TYSON AIRPORT, TN 65 71 48 70 / 80 80 10 0 OAK RIDGE, TN 64 71 46 71 / 80 80 10 0 TRI CITIES AIRPORT, TN 61 72 44 67 / 60 80 10 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
614 PM EDT WED APR 8 2015 .DISCUSSION...QUICK UPDATE BASED ON PRESENT CONDITIONS AND HI-RES MODELS. CAP CURRENTLY WINNING BATTLE AS DEEP CONVECTION STAYING TO THE NORTH. RAP SOUNDING SHOWING WARM LAYER AT 700MB THAT NAM IS NOT SHOWING. MODELS GENERALLY AGREE THAT 700MB WARM ADVECTION IS OCCURRING...SO THINK THAT CAP WILL CONTINUE TO KEEP MOST CONVECTION TO THE NORTH. HOWEVER...AROUND 04Z-08Z RAP 700MB TEMP MAP SHOWS THERMAL TROUGH PUSHING THRU NE SECTIONS FROM NW-SE. SO BEST CHANCES OF CAP WEAKENING IN THAT AREA DURING THAT TIME PERIOD. CURRENT POP GRADIENT PATTERN LOOKS GOOD...BUT WILL LOWER POPS IN GENERAL...BUT KEEPING HIGHEST POPS IN THE NORTHEAST. WILL KEEP MENTION OF THUNDER. 850MB LOW LEVEL JET WILL BE INCREASING...BUT ALONG WITH THE CAP...SO LOOKS LIKE MOST OF THIS INCREASED TRANSPORT WILL BE GOING INTO DEEP CONVECTION MAINLY NORTH. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 64 83 64 72 / 10 20 90 90 KNOXVILLE MCGHEE TYSON AIRPORT, TN 62 82 64 70 / 10 20 70 90 OAK RIDGE, TN 63 82 63 70 / 10 20 80 90 TRI CITIES AIRPORT, TN 56 81 60 70 / 30 30 70 90 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ GM
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1203 PM CDT WED APR 8 2015 .UPDATE... /ISSUED 1014 AM CDT WED APR 8 2015/ SKIES ARE MOSTLY SUNNY OVER MUCH OF THE FORECAST AREA THIS MORNING WITH TEMPERATURES IN THE 70S. SOME ISOLATED SHOWERS CONTINUE TO MOVE OVER NORTHERN SECTIONS OF THE FORECAST AREA BUT THIS ACTIVITY IS JUST ABOUT DONE. SOME ISOLATED THUNDERSTORMS MAY MOVE THROUGH NORTHERN SECTIONS OF THE FORECAST AREA THIS AFTERNOON. WILL SEND AN UPDATE TO THE FORECAST TO REMOVE MORNING WORDING. ARS .DISCUSSION... /ISSUED 608 AM CDT WED APR 8 2015/ AS OF 4AM...TEMPERATURES ARE MILD ONCE AGAIN THIS MORNING WITH READINGS MAINLY IN THE MID TO UPPER 60S ACROSS THE REGION. EARLIER CONVECTION NEAR THE SOUTHERN KANSAS/MISSOURI BORDER HAS WEAKENED SIGNIFICANTLY IN THE LAST COUPLE OF HOURS WITH ONLY LIGHT SHOWERS DEVELOPING TO THE SOUTH OF THE LEFTOVER COMPLEX. A BROAD AREA OF SCATTERED SHOWERS AND THUNDERSTORMS WERE MOVING OVER PORTIONS OF CENTRAL AND NORTHEAST ARKANSAS ASSOCIATED WITH A WEAK SHORTWAVE EMBEDDED IN THE MEAN FLOW. WATER VAPOR IMAGERY ALSO SHOWS A LARGE CUTOFF LOW ROTATING OVER THE GREAT BASIN THIS MORNING. THIS FEATURE WILL BE MAIN WEATHER MAKER ACROSS OUR AREA OVER THE NEXT 48 HOURS OR SO. SHORT TERM...TODAY THROUGH FRIDAY... THE HRRR HI-RES SHORT TERM MODEL INDICATES THAT SHOWERS AND SCATTERED THUNDERSTORMS WILL MOVE THROUGH THE MID-SOUTH AGAIN THIS MORNING. COVERAGE IS EXPECTED TO LESS THAN YESTERDAY...BUT WILL STILL WARRANT A 20 POP. BY EARLY AFTERNOON...SHOWERS WILL EXIT THE AREA AND SLIGHT UPPER LEVEL RIDGING WILL RESULT IN CLEARING SKIES AND VERY WARM CONDITIONS FOR THIS TIME OF YEAR. READINGS WILL BE IN THE LOW TO MID 80S THIS AFTERNOON...WHICH IS AS MUCH AS 15 DEGREES ABOVE THE CLIMATOLOGICAL NORMAL FOR THIS TIME OF YEAR AND NEAR RECORD HIGHS. BY LATE TONIGHT...MODELS ARE IN REASONABLE AGREEMENT THAT THE UPPER LEVEL CLOSED LOW OUT WEST WILL EVOLVE INTO AN OPEN WAVE AS IT MOVES ACROSS THE ROCKIES...AND SURFACE LOW PRESSURE WILL DEVELOP NEAR THE OKLAHOMA PANHANDLE. THIS SURFACE LOW WILL MOVE ACROSS THE CENTRAL PLAINS AND INTO THE GREAT LAKES REGION FROM THURSDAY MORNING AND INTO FRIDAY. AS IT DOES...A STRONG COLD FRONT WILL SWEEP ACROSS THE MISSISSIPPI VALLEY AND INTERACT WITH A MODERATELY UNSTABLE AIRMASS. MLCAPE VALUES APPROACHING 2000 J/KG AND A 50 KT MID LEVEL JET WILL SUPPORT AT LEAST A FEW STRONG TO SEVERE STORMS. STORM MODE IS STILL A LITTLE UNCLEAR AT THE MOMENT...BUT IT DOES APPEAR SOME STORMS COULD DEVELOP AHEAD OF THE LINE AS HEIGHT FALLS OVERSPREAD THE REGION...BEFORE CONGEALING INTO A QLCS STRUCTURE BY LATE THURSDAY EVENING. DAMAGING WINDS AND LARGE HAIL LOOK TO BE THE MAIN THREATS...WITH A SECONDARY THREAT OF FLASH FLOODING. TORNADO THREAT LOOKS VERY MINIMAL...AS THE FAVORABLE JET STRUCTURE REMAINS WELL TO OUR NORTH. WILL CONTINUE TO MAKE A MENTION OF SEVERE STORMS IN THE HWO WITH THE BEST CHANCES REMAINING OVER NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...AND PORTIONS OF NORTHWEST TENNESSEE. BY FRIDAY AFTERNOON...THE FRONT WILL PUSH TO THE SOUTH AND EAST AS SURFACE HIGH PRESSURE BUILDS IN. TEMPERATURES WILL BE MILD DURING THE DAY WITH UPPER 60S AND LOWER 70S EXPECTED. SATURDAY WILL BE A BEAUTIFUL MILD SPRING DAY WITH LOW HUMIDITY... TEMPERATURES IN THE LOWER 70...AND ABUNDANT SUNSHINE. LONG TERM...SUNDAY THROUGH EARLY NEXT WEEK... A STALLED COLD FRONT TO OUR SOUTH WILL PUSH NORTH AS A WARM FRONT ON SUNDAY MORNING. AS IT DOES...SHOWERS AND THUNDERSTORMS WILL OVERSPREAD THE REGION BY THE AFTERNOON HOURS. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE ON MONDAY BEFORE A COLD FRONT PUSHES THROUGH THE MID-SOUTH BY TUESDAY. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO MIDWEEK AS RETURN FLOW REMAINS DOMINANT ACROSS THE REGION. AC3 && .AVIATION... 18Z TAF SET VFR CONDITIONS EXPECTED THROUGH MUCH OF THE NEXT 24 HOURS. THE ONLY EXCEPTION MAY BE BETWEEN 09-15Z WHEN STRATUS MAY MOVE UP OVER THE AREA FROM THE SOUTH LOWERING CIGS TO MVFR. ALSO INTRODUCED VCTS WORDING AT KJBR BETWEEN 9Z-13Z FOR REMNANT TSRAS THAT MAY PUSH IN FROM SOUTHERN M0. STRONG S TO SSW WINDS WILL CONTINUE OVER THE AREA OVER THE NEXT 24 HOURS. SPEEDS WILL GENERALLY BE BETWEEN 10-15 KTS WITH HIGHER GUSTS AT TIMES. KRM && && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1014 AM CDT WED APR 8 2015 .DISCUSSION... SKIES ARE MOSTLY SUNNY OVER MUCH OF THE FORECAST AREA THIS MORNING WITH TEMPERATURES IN THE 70S. SOME ISOLATED SHOWERS CONTINUE TO MOVE OVER NORTHERN SECTIONS OF THE FORECAST AREA BUT THIS ACTIVITY IS JUST ABOUT DONE. SOME ISOLATED THUNDERSTORMS MAY MOVE THROUGH NORTHERN SECTIONS OF THE FORECAST AREA THIS AFTERNOON. WILL SEND AN UPDATE TO THE FORECAST TO REMOVE MORNING WORDING. ARS && .PREV DISCUSSION... /ISSUED 608 AM CDT WED APR 8 2015/ AS OF 4AM...TEMPERATURES ARE MILD ONCE AGAIN THIS MORNING WITH READINGS MAINLY IN THE MID TO UPPER 60S ACROSS THE REGION. EARLIER CONVECTION NEAR THE SOUTHERN KANSAS/MISSOURI BORDER HAS WEAKENED SIGNIFICANTLY IN THE LAST COUPLE OF HOURS WITH ONLY LIGHT SHOWERS DEVELOPING TO THE SOUTH OF THE LEFTOVER COMPLEX. A BROAD AREA OF SCATTERED SHOWERS AND THUNDERSTORMS WERE MOVING OVER PORTIONS OF CENTRAL AND NORTHEAST ARKANSAS ASSOCIATED WITH A WEAK SHORTWAVE EMBEDDED IN THE MEAN FLOW. WATER VAPOR IMAGERY ALSO SHOWS A LARGE CUTOFF LOW ROTATING OVER THE GREAT BASIN THIS MORNING. THIS FEATURE WILL BE MAIN WEATHER MAKER ACROSS OUR AREA OVER THE NEXT 48 HOURS OR SO. SHORT TERM...TODAY THROUGH FRIDAY... THE HRRR HI-RES SHORT TERM MODEL INDICATES THAT SHOWERS AND SCATTERED THUNDERSTORMS WILL MOVE THROUGH THE MID-SOUTH AGAIN THIS MORNING. COVERAGE IS EXPECTED TO LESS THAN YESTERDAY...BUT WILL STILL WARRANT A 20 POP. BY EARLY AFTERNOON...SHOWERS WILL EXIT THE AREA AND SLIGHT UPPER LEVEL RIDGING WILL RESULT IN CLEARING SKIES AND VERY WARM CONDITIONS FOR THIS TIME OF YEAR. READINGS WILL BE IN THE LOW TO MID 80S THIS AFTERNOON...WHICH IS AS MUCH AS 15 DEGREES ABOVE THE CLIMATOLOGICAL NORMAL FOR THIS TIME OF YEAR AND NEAR RECORD HIGHS. BY LATE TONIGHT...MODELS ARE IN REASONABLE AGREEMENT THAT THE UPPER LEVEL CLOSED LOW OUT WEST WILL EVOLVE INTO AN OPEN WAVE AS IT MOVES ACROSS THE ROCKIES...AND SURFACE LOW PRESSURE WILL DEVELOP NEAR THE OKLAHOMA PANHANDLE. THIS SURFACE LOW WILL MOVE ACROSS THE CENTRAL PLAINS AND INTO THE GREAT LAKES REGION FROM THURSDAY MORNING AND INTO FRIDAY. AS IT DOES...A STRONG COLD FRONT WILL SWEEP ACROSS THE MISSISSIPPI VALLEY AND INTERACT WITH A MODERATELY UNSTABLE AIRMASS. MLCAPE VALUES APPROACHING 2000 J/KG AND A 50 KT MID LEVEL JET WILL SUPPORT AT LEAST A FEW STRONG TO SEVERE STORMS. STORM MODE IS STILL A LITTLE UNCLEAR AT THE MOMENT...BUT IT DOES APPEAR SOME STORMS COULD DEVELOP AHEAD OF THE LINE AS HEIGHT FALLS OVERSPREAD THE REGION...BEFORE CONGEALING INTO A QLCS STRUCTURE BY LATE THURSDAY EVENING. DAMAGING WINDS AND LARGE HAIL LOOK TO BE THE MAIN THREATS...WITH A SECONDARY THREAT OF FLASH FLOODING. TORNADO THREAT LOOKS VERY MINIMAL...AS THE FAVORABLE JET STRUCTURE REMAINS WELL TO OUR NORTH. WILL CONTINUE TO MAKE A MENTION OF SEVERE STORMS IN THE HWO WITH THE BEST CHANCES REMAINING OVER NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...AND PORTIONS OF NORTHWEST TENNESSEE. BY FRIDAY AFTERNOON...THE FRONT WILL PUSH TO THE SOUTH AND EAST AS SURFACE HIGH PRESSURE BUILDS IN. TEMPERATURES WILL BE MILD DURING THE DAY WITH UPPER 60S AND LOWER 70S EXPECTED. SATURDAY WILL BE A BEAUTIFUL MILD SPRING DAY WITH LOW HUMIDITY... TEMPERATURES IN THE LOWER 70...AND ABUNDANT SUNSHINE. LONG TERM...SUNDAY THROUGH EARLY NEXT WEEK... A STALLED COLD FRONT TO OUR SOUTH WILL PUSH NORTH AS A WARM FRONT ON SUNDAY MORNING. AS IT DOES...SHOWERS AND THUNDERSTORMS WILL OVERSPREAD THE REGION BY THE AFTERNOON HOURS. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE ON MONDAY BEFORE A COLD FRONT PUSHES THROUGH THE MID-SOUTH BY TUESDAY. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO MIDWEEK AS RETURN FLOW REMAINS DOMINANT ACROSS THE REGION. AC3 && .AVIATION... 12Z TAF CYCLE (08/12Z-09/12Z) IFR CONDITIONS IN FOG WILL OCCUR AT KTUP UNTIL 13Z...OTHERWISE MVFR CONDITIONS ARE POSSIBLE AT THE TAF SITES THROUGH 14Z. MENTIONED VCTS AT KJBR UNTIL 14Z WITH PATCHY LIGHT RAIN AFFECTING KMEM...KMKL...AND KJBR UNTIL 14Z. VFR CONDITIONS ARE EXPECTED AFTER 14Z THROUGH THE REMAINDER OF THE PERIOD. WINDS TODAY AT KMEM...KMKL...AND KJBR INCREASING FROM THE SW AT 12-18 KTS WITH GUSTS 20-27 KTS. WINDS TODAY AT KTUP BECOMING SW 12 KTS. WINDS TONIGHT AT KMEM...KMKL AND KJBR S 8-13 KTS BECOMING AT KJBR AFTER 09/07Z S 15 KTS WITH GUSTS 22 KTS. WINDS TONIGHT AT KTUP S 6-8 KTS. JCL && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
608 AM CDT WED APR 8 2015 .UPDATE... UPDATED TO INCLUDE THE 12Z AVIATION DISCUSSION BELOW. JCL && .DISCUSSION... /ISSUED 434 AM CDT WED APR 8 2015/ AS OF 4AM...TEMPERATURES ARE MILD ONCE AGAIN THIS MORNING WITH READINGS MAINLY IN THE MID TO UPPER 60S ACROSS THE REGION. EARLIER CONVECTION NEAR THE SOUTHERN KANSAS/MISSOURI BORDER HAS WEAKENED SIGNIFICANTLY IN THE LAST COUPLE OF HOURS WITH ONLY LIGHT SHOWERS DEVELOPING TO THE SOUTH OF THE LEFTOVER COMPLEX. A BROAD AREA OF SCATTERED SHOWERS AND THUNDERSTORMS WERE MOVING OVER PORTIONS OF CENTRAL AND NORTHEAST ARKANSAS ASSOCIATED WITH A WEAK SHORTWAVE EMBEDDED IN THE MEAN FLOW. WATER VAPOR IMAGERY ALSO SHOWS A LARGE CUTOFF LOW ROTATING OVER THE GREAT BASIN THIS MORNING. THIS FEATURE WILL BE MAIN WEATHER MAKER ACROSS OUR AREA OVER THE NEXT 48 HOURS OR SO. SHORT TERM...TODAY THROUGH FRIDAY... THE HRRR HI-RES SHORT TERM MODEL INDICATES THAT SHOWERS AND SCATTERED THUNDERSTORMS WILL MOVE THROUGH THE MID-SOUTH AGAIN THIS MORNING. COVERAGE IS EXPECTED TO LESS THAN YESTERDAY...BUT WILL STILL WARRANT A 20 POP. BY EARLY AFTERNOON...SHOWERS WILL EXIT THE AREA AND SLIGHT UPPER LEVEL RIDGING WILL RESULT IN CLEARING SKIES AND VERY WARM CONDITIONS FOR THIS TIME OF YEAR. READINGS WILL BE IN THE LOW TO MID 80S THIS AFTERNOON...WHICH IS AS MUCH AS 15 DEGREES ABOVE THE CLIMATOLOGICAL NORMAL FOR THIS TIME OF YEAR AND NEAR RECORD HIGHS. BY LATE TONIGHT...MODELS ARE IN REASONABLE AGREEMENT THAT THE UPPER LEVEL CLOSED LOW OUT WEST WILL EVOLVE INTO AN OPEN WAVE AS IT MOVES ACROSS THE ROCKIES...AND SURFACE LOW PRESSURE WILL DEVELOP NEAR THE OKLAHOMA PANHANDLE. THIS SURFACE LOW WILL MOVE ACROSS THE CENTRAL PLAINS AND INTO THE GREAT LAKES REGION FROM THURSDAY MORNING AND INTO FRIDAY. AS IT DOES...A STRONG COLD FRONT WILL SWEEP ACROSS THE MISSISSIPPI VALLEY AND INTERACT WITH A MODERATELY UNSTABLE AIRMASS. MLCAPE VALUES APPROACHING 2000 J/KG AND A 50 KT MID LEVEL JET WILL SUPPORT AT LEAST A FEW STRONG TO SEVERE STORMS. STORM MODE IS STILL A LITTLE UNCLEAR AT THE MOMENT...BUT IT DOES APPEAR SOME STORMS COULD DEVELOP AHEAD OF THE LINE AS HEIGHT FALLS OVERSPREAD THE REGION...BEFORE CONGEALING INTO A QLCS STRUCTURE BY LATE THURSDAY EVENING. DAMAGING WINDS AND LARGE HAIL LOOK TO BE THE MAIN THREATS...WITH A SECONDARY THREAT OF FLASH FLOODING. TORNADO THREAT LOOKS VERY MINIMAL...AS THE FAVORABLE JET STRUCTURE REMAINS WELL TO OUR NORTH. WILL CONTINUE TO MAKE A MENTION OF SEVERE STORMS IN THE HWO WITH THE BEST CHANCES REMAINING OVER NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...AND PORTIONS OF NORTHWEST TENNESSEE. BY FRIDAY AFTERNOON...THE FRONT WILL PUSH TO THE SOUTH AND EAST AS SURFACE HIGH PRESSURE BUILDS IN. TEMPERATURES WILL BE MILD DURING THE DAY WITH UPPER 60S AND LOWER 70S EXPECTED. SATURDAY WILL BE A BEAUTIFUL MILD SPRING DAY WITH LOW HUMIDITY... TEMPERATURES IN THE LOWER 70...AND ABUNDANT SUNSHINE. LONG TERM...SUNDAY THROUGH EARLY NEXT WEEK... A STALLED COLD FRONT TO OUR SOUTH WILL PUSH NORTH AS A WARM FRONT ON SUNDAY MORNING. AS IT DOES...SHOWERS AND THUNDERSTORMS WILL OVERSPREAD THE REGION BY THE AFTERNOON HOURS. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE ON MONDAY BEFORE A COLD FRONT PUSHES THROUGH THE MID-SOUTH BY TUESDAY. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO MIDWEEK AS RETURN FLOW REMAINS DOMINANT ACROSS THE REGION. AC3 && .AVIATION... 12Z TAF CYCLE (08/12Z-09/12Z) IFR CONDITIONS IN FOG WILL OCCUR AT KTUP UNTIL 13Z...OTHERWISE MVFR CONDITIONS ARE POSSIBLE AT THE TAF SITES THROUGH 14Z. MENTIONED VCTS AT KJBR UNTIL 14Z WITH PATCHY LIGHT RAIN AFFECTING KMEM...KMKL...AND KJBR UNTIL 14Z. VFR CONDITIONS ARE EXPECTED AFTER 14Z THROUGH THE REMAINDER OF THE PERIOD. WINDS TODAY AT KMEM...KMKL...AND KJBR INCREASING FROM THE SW AT 12-18 KTS WITH GUSTS 20-27 KTS. WINDS TODAY AT KTUP BECOMING SW 12 KTS. WINDS TONIGHT AT KMEM...KMKL AND KJBR S 8-13 KTS BECOMING AT KJBR AFTER 09/07Z S 15 KTS WITH GUSTS 22 KTS. WINDS TONIGHT AT KTUP S 6-8 KTS. JCL && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
434 AM CDT WED APR 8 2015 .DISCUSSION... AS OF 4AM...TEMPERATURES ARE MILD ONCE AGAIN THIS MORNING WITH READINGS MAINLY IN THE MID TO UPPER 60S ACROSS THE REGION. EARLIER CONVECTION NEAR THE SOUTHERN KANSAS/MISSOURI BORDER HAS WEAKENED SIGNIFICANTLY IN THE LAST COUPLE OF HOURS WITH ONLY LIGHT SHOWERS DEVELOPING TO THE SOUTH OF THE LEFTOVER COMPLEX. A BROAD AREA OF SCATTERED SHOWERS AND THUNDERSTORMS WERE MOVING OVER PORTIONS OF CENTRAL AND NORTHEAST ARKANSAS ASSOCIATED WITH A WEAK SHORTWAVE EMBEDDED IN THE MEAN FLOW. WATER VAPOR IMAGERY ALSO SHOWS A LARGE CUTOFF LOW ROTATING OVER THE GREAT BASIN THIS MORNING. THIS FEATURE WILL BE MAIN WEATHER MAKER ACROSS OUR AREA OVER THE NEXT 48 HOURS OR SO. SHORT TERM...TODAY THROUGH FRIDAY... THE HRRR HI-RES SHORT TERM MODEL INDICATES THAT SHOWERS AND SCATTERED THUNDERSTORMS WILL MOVE THROUGH THE MID-SOUTH AGAIN THIS MORNING. COVERAGE IS EXPECTED TO LESS THAN YESTERDAY...BUT WILL STILL WARRANT A 20 POP. BY EARLY AFTERNOON...SHOWERS WILL EXIT THE AREA AND SLIGHT UPPER LEVEL RIDGING WILL RESULT IN CLEARING SKIES AND VERY WARM CONDITIONS FOR THIS TIME OF YEAR. READINGS WILL BE IN THE LOW TO MID 80S THIS AFTERNOON...WHICH IS AS MUCH AS 15 DEGREES ABOVE THE CLIMATOLOGICAL NORMAL FOR THIS TIME OF YEAR AND NEAR RECORD HIGHS. BY LATE TONIGHT...MODELS ARE IN REASONABLE AGREEMENT THAT THE UPPER LEVEL CLOSED LOW OUT WEST WILL EVOLVE INTO AN OPEN WAVE AS IT MOVES ACROSS THE ROCKIES...AND SURFACE LOW PRESSURE WILL DEVELOP NEAR THE OKLAHOMA PANHANDLE. THIS SURFACE LOW WILL MOVE ACROSS THE CENTRAL PLAINS AND INTO THE GREAT LAKES REGION FROM THURSDAY MORNING AND INTO FRIDAY. AS IT DOES...A STRONG COLD FRONT WILL SWEEP ACROSS THE MISSISSIPPI VALLEY AND INTERACT WITH A MODERATELY UNSTABLE AIRMASS. MLCAPE VALUES APPROACHING 2000 J/KG AND A 50 KT MID LEVEL JET WILL SUPPORT AT LEAST A FEW STRONG TO SEVERE STORMS. STORM MODE IS STILL A LITTLE UNCLEAR AT THE MOMENT...BUT IT DOES APPEAR SOME STORMS COULD DEVELOP AHEAD OF THE LINE AS HEIGHT FALLS OVERSPREAD THE REGION...BEFORE CONGEALING INTO A QLCS STRUCTURE BY LATE THURSDAY EVENING. DAMAGING WINDS AND LARGE HAIL LOOK TO BE THE MAIN THREATS...WITH A SECONDARY THREAT OF FLASH FLOODING. TORNADO THREAT LOOKS VERY MINIMAL...AS THE FAVORABLE JET STRUCTURE REMAINS WELL TO OUR NORTH. WILL CONTINUE TO MAKE A MENTION OF SEVERE STORMS IN THE HWO WITH THE BEST CHANCES REMAINING OVER NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...AND PORTIONS OF NORTHWEST TENNESSEE. BY FRIDAY AFTERNOON...THE FRONT WILL PUSH TO THE SOUTH AND EAST AS SURFACE HIGH PRESSURE BUILDS IN. TEMPERATURES WILL BE MILD DURING THE DAY WITH UPPER 60S AND LOWER 70S EXPECTED. SATURDAY WILL BE A BEAUTIFUL MILD SPRING DAY WITH LOW HUMIDITY... TEMPERATURES IN THE LOWER 70...AND ABUNDANT SUNSHINE. LONG TERM...SUNDAY THROUGH EARLY NEXT WEEK... A STALLED COLD FRONT TO OUR SOUTH WILL PUSH NORTH AS A WARM FRONT ON SUNDAY MORNING. AS IT DOES...SHOWERS AND THUNDERSTORMS WILL OVERSPREAD THE REGION BY THE AFTERNOON HOURS. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE ON MONDAY BEFORE A COLD FRONT PUSHES THROUGH THE MID-SOUTH BY TUESDAY. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO MIDWEEK AS RETURN FLOW REMAINS DOMINANT ACROSS THE REGION. AC3 && .AVIATION... 06Z TAF SET VFR CONDITIONS PREVAIL AT ALL TAF SITES TONIGHT. HI RES GUIDANCE SHOWS SOME SHOWER DEVELOPMENT DURING THE EARLY MORNING SO HAVE ADDED -RA TO THE TEMPO GROUP BETWEEN 09 AND 12Z FOR JBR AND MEM. THIS SHOULD MOVE OUT QUICKLY WEDNESDAY MORNING. MVFR CONDITIONS ARE POSSIBLE DURING THIS PERIOD AS WELL. THIS WILL PERSIST THROUGH THE EARLY MORNING HOURS BUT LIFT AS THE DAY PROGRESSES. VFR CONDITIONS ARE EXPECTED AFTER 18Z AT ALL SITES. WINDS WILL BE STRONG OUT OF THE SOUTH NEAR 15 KTS WITH GUSTS NEAR 20 KTS. TVT && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1009 PM CDT THU APR 9 2015 .UPDATE... UPDATE FOR RAIN CHANCES. && .DISCUSSION... WILL RAISE POPS OVERNIGHT INTO FRI MORNING. LATEST HRRR IS MATCHING UP WELL WITH ADDITIONAL DEVELOPMENT ON THE APPROACHING COLD FRONT. THE FRONT COUPLED WITH A WEAK DISTURBANCE MOVING INTO THE STATE SHOULD YIELD HIGHER POPS THROUGH 15Z FRI. NEW ZONES OUT BY 1015 PM. 43 && .PREV DISCUSSION... /ISSUED 858 PM CDT THU APR 9 2015/ UPDATE... SEE EVENING UPDATE. DISCUSSION... AT 8 PM...A COLD FRONT EXTENDED FROM SPRINGFIELD MO TO PARIS TO SAN ANGELO. A PRE FRONTAL TROUGH EXTENDED FROM TEXARKANA TO WACO TO A WEAK AREA OF LOW PRESSURE WEST OF LAREDO. SHRA/TSRA DEVELOPED ALONG THE PRE FRONTAL TROUGH AND HAVE THUS FAR REMAINED JUST NORTH AND WEST OF THE HGX CWA. MODELS HAVE BEEN WAY TOO AGGRESSIVE WITH RAINFALL THIS EVENING AND HAVE LEANED TOWARD THE 18Z TEXAS TECH WRF SINCE IT INITIALIZED BEST. 00Z SOUNDINGS SHOW PW VALUES HAVE GONE UP TO 1.50 INCHES AND THE ATMOSPHERE IS LESS CAPPED THAN LAST EVENING. SOUNDINGS STILL SHOW SOME DRY AIR BETWEEN 850 AND 700 MB. THE COLD FRONT IS SURGING SOUTH AT A PRETTY GOOD CLIP OVER CENTRAL TEXAS WHILE THE EASTERN PART OF THE FRONT IS MOVING MORE SLUGGISHLY. THE DILEMMA FOR THE NIGHT IS FAR SOUTH THE FRONT MOVES AND ITS EFFECT ON TEMPERATURES AND RAIN CHANCES. THE TEXAS TECH WRF KEEPS THINGS RELATIVELY DRY OVERNIGHT AS THE CONVECTION PUSHES NORTHEAST AND AWAY FROM THE STATE. STILL FEEL THERE WILL BE SUFFICIENT LOW LEVEL CONVERGENCE ALONG THE BOUNDARY TO GENERATE A FEW SHOWERS/THUNDERSTORMS OVERNIGHT AND WILL LEAVE POPS AS THEY ARE. A S/WV ON WATER VAPOR WILL APPROACH SE TX FRIDAY MORNING AND FEEL SHRA/TSRA WILL INCREASE IN COVERAGE BY MID MORNING. MIN TEMPS ARE A TOUGH CALL AND WILL BE STRONGLY DEPENDENT ON THE FRONTAL POSITION. SINCE THE EASTERN PART OF THE FRONT IS MOVING SLOWER...FEEL THE FRONT WILL HAVE TROUBLE CLEARING THE CWA. CURRENT MIN TEMPS LOOK GOOD BASED ON WHERE THE FRONT IS EXPECTED TO BE AT 12Z FRIDAY. TWEAKED SKY GRIDS TO MATCH CURRENT OBS OTHERWISE WILL LEAVE CURRENT FCST AS IS. PREV DISCUSSION... /ISSUED 639 PM CDT THU APR 9 2015/ DISCUSSION... SEE THE 00Z AVIATION DISCUSSION BELOW. 40 AVIATION... A FRONTAL BOUNDARY WILL SINK INTO SE TX FROM THE NORTH TONIGHT. THE MODELS DIFFERED ON THE FRONTAL TIMING AND ON COVERAGE OF SHOWERS AND THUNDERSTORMS. DECIDED TO GO WITH A CONSENSUS OF THE RAP...NAM...AND GFS. WITH THIS IN MIND...THINK THAT MVFR IS FAIRLY CERTAIN TO DEVELOP OVER THE INLAND COUNTIES SOMETIME BETWEEN 03Z AND 09Z. MVFR CONDITIONS HAD ALREADY DEVELOPED OVER KLBX AND KGLS AT 23Z. THINK THAT WITH THE END OF DAYTIME HEATING...THE RAIN AND THUNDERSTORM COVERAGE WILL DECREASE AS THE FRONT REACHES INTO THE KCLL AND KUTS AREAS OVERNIGHT TONIGHT. HOWEVER...CHANCES OF RAIN WILL INCREASE OVER THE METRO HOUSTON SITES AND SOUTHWARD AFTER MID MORNING AND THROUGH MOST OF THE AFTERNOON ON FRIDAY. 40 PREV DISCUSSION... /ISSUED 336 PM CDT THU APR 9 2015/ DISCUSSION... SCT TSRA DEVELOPING N AND NW OF SE TX THIS AFT. BEGINNING TO SEE ISO TSTMS ACROSS FAR NORTHERN AREAS AS TEMPS REACH THE MID 80S. THE CF WILL APPROACH NW AREAS OF SE TX DURING THE LATE EVE HOURS AND WILL MOVE TO NEAR A CLL-DKR LINE AROUND OR A LITTLE AFTER MIDNIGHT. EXPECT SCT TSRA ALONG THE BOUNDARY LATE TONIGHT...WITH CONVECTION WEAKENING AS THE BOUNDARY SINKS SOUTH ACROSS SE TX DURING THE EARLY MORNING HOURS. THE SLIGHT SVR TSTM RISK GENERALLY NORTH OF A MADISONVILLE TO TRINITY LINE LOOKS APPROPRIATE FOR THIS AFT/TONIGHT. HAVE MADE SOME COOLER ADJUSTMENTS TO FRIDAY`S TEMPS AS THE FRONT WILL PROVIDE COOLING TO THE NORTHWEST HALF OF THE AREA. STILL A LITTLE UNCERTAIN HOW FAR SOUTH THE FRONT WILL MAKE IT ON FRIDAY BEFORE STALLING. THERE WILL BE AMPLE CLOUD COVER AREAWIDE WITH SHWRS/TSTMS IN THE VICINITY OF THE BOUNDARY...SO COOLER TEMPS ARE EXPECTED FOR ALL...WITH THE EXCEPTION OF POSSIBLY THE IMMEDIATE COAST. WILL TAPER POPS ON FRIDAY FROM THE SOUTHEAST THIRD (HIGHEST) TO THE NORTH. COULD BE AN ISO SVR THREAT FRIDAY NEAR AND SOUTH OF THE FRONT...BUT THIS THREAT IS CONDITIONAL ON INSTABILITY...WHICH COULD BE LACKING. IF THE INSTABILITY IS SUFFICIENT...COULD SEE A SVR WIND GUST THREAT WITH ANY ORGANIZED CONVECTION. SOUTHERLY WINDS WILL RETURN ON SATURDAY WITH SHWRS/TSTMS LIKELY ACROSS MOST OF SE TX WITH AN APPROACHING DISTURBANCE. MOISTURE LEVELS WILL CONTINUE TO INCREASE SUN/MON AS A STORM SYSTEM APPROACHES FROM THE WEST AND MOVES NORTH OF THE AREA. SE TX WILL LIKELY SEE A HEAVY RAINFALL THREAT LATE SUNDAY AND INTO MONDAY WITH WELL ABOVE NORMAL MOISTURE LEVELS AND UPPER LEVEL DIFFLUENCE PRESENT. CHC POPS CONTINUE NEXT WEEK AS A LARGE SCALE MID/UPPER TROF/CLOSED LOW DEVELOPS OVER THE CENTRAL PLAINS. THIS FEATURE WILL LIKELY ALLOW A STRONG COLD FRONT TO MOVE THROUGH SE TX NEXT THU. SHOULD HAVE A COOL AND BENIGN PD IN THE WAKE OF THIS FRONT/FEATURE. 33 MARINE... SOUTHERLY WINDS WILL DECREASE THIS EVENING...A CAUTION STATEMENT WILL CONTINUE THROUGH 8 PM. SEAS OF 2-4 FEET WILL CONTINUE THROUGH SUNDAY. SHOWER AND THUNDERSTORM CHANCES INCREASE ON FRIDAY AND CONTINUE INTO EARLY NEXT WEEK WITH AN UNSETTLED WEATHER PATTERN IN PLACE. 14/33 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 62 73 64 77 66 / 40 30 20 60 60 HOUSTON (IAH) 69 77 67 79 68 / 30 60 30 60 60 GALVESTON (GLS) 72 78 69 76 70 / 20 60 30 60 50 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...43
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
347 PM CDT WED APR 8 2015 .SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)... OVERALL HIGHLIGHTS FOR THIS PERIOD WILL FOCUS ON THE ISOLATED TO SCATTERED STRONG TO SEVERE STORM POSSIBILITIES THURSDAY AFTERNOON INTO THURSDAY EVENING FOR AREAS GENERALLY ALONG AND NORTH OF A FREDERICKSBURG TO LA GRANGE LINE. FOR TODAY...WATER VAPOR IMAGERY CHANNELS DEPICT A SHORTWAVE TROUGH OVER UTAH WITH RAP ANALYSIS INDICATING AN ENHANCED MID-LEVEL WIND SPEED BELT EXTENDING INTO SOUTH-CENTRAL TEXAS BACK WESTWARD INTO NORTHERN MEXICO. THE INCREASING H5-H3 WIND FLOW IS AIDING IN BETTER DIVERGENCE ALOFT AND HELPING GENERATE SOME ELEVATED SHOWERS ABOVE A CAPPING INVERSION. 315K THETA SURFACE DEPICTS LOWEST CONDENSATION PRESSURE DEFICITS WITH LOWER LAYERS STILL DRY. THIS IS LIMITING OVERALL AMOUNTS FROM REACHING THE GROUND SO FAR THIS AFTERNOON. THIS BIG QUESTION FOR LATE AFTERNOON WILL BE HOW MUCH CLOUD COVER EROSION OCCURS WHICH COULD ALLOW FOR MORE SURFACE HEATING AND POSSIBLY AID SURFACE BASED STORMS OUT WEST. VIS SATELLITE TRENDS SHOW CLEARING ACROSS MAVERICK BUT VAL VERDE REMAINS MOSTLY SOCKED IN. SOME ADDITIONAL CLEARING IS EXPECTED ACROSS THE NORTHERN RIO GRANDE PLAINS THROUGH 6PM BUT BOTH GFS/NAM FORECAST SOUNDINGS SUGGEST OVERALL CAP SHOULD HOLD AND LIMIT SURFACE BASED CONVECTIVE POTENTIAL. DESPITE THIS FACT...ELEVATED INSTABILITY WILL GROW AS CAPPING INVERSION THINS ABOVE 700MB. WHILE AN ISOLATED STRONG STORM CAPABLE OF SMALL HAIL OR WIND GUSTS TO 40 MPH CAN NOT BE ENTIRELY RULED OUT THROUGH THIS EVENING...THE CHANCES ARE RELATIVELY LOW. OVERNIGHT...EXPECT SOME LINGERING SHOWERS ACROSS THE RIO GRANDE PLAINS WITH SOUTHEASTERN AREAS MOSTLY DRY. FOR THURSDAY...THE SHORTWAVE TROUGH OVER UTAH WILL HELP PUSH A WEAK FRONT TOWARDS THE REGION THAT WILL IMPINGE ON THE DRYLINE TO EDGE TOWARDS THE HILL COUNTY BY THE AFTERNOON. AFTER MORNING CLOUD COVER SLOWLY ERODES...SURFACE INSTABILITY IS PROGGED TO INCREASE TOWARDS 3000 J/KG AS MIXING OCCURS BY MID AFTERNOON. BOTH NAM/GFS BUFR SOUNDINGS INDICATE THE EROSION OF THE CAP ACROSS NORTHERN AREAS WITH 30KT 0-6 KM SHEAR IN PLACE. WHILE NOT SUPER HIGH...THIS AMOUNT IN CONJUNCTION WITH A LOW-LEVEL FORCING BOUNDARY (DRYLINE) COULD HELP SUPPORT SOME ISOLATED TO SCATTERED STORMS THAT COULD TAKE ON A SUPERCELL APPEARANCE. MOST FAVORED AREAS WILL BE TOWARDS WACO TO DALLAS WITH TAIL END CELLS POSSIBLE TO SKIRT BURNET TO WILLIAMSON. QUARTER SIZED HAIL AND WIND GUSTS TO 60 MPH WILL BE PRIMARY THREATS. THIS ACTIVITY WILL WANE THROUGH THE MID EVENING HOURS AS INSTABILITY DECREASES BUT MID-LEVEL SHOWERS COULD REGENERATE LATE THURSDAY INTO FRIDAY AS AN IMPULSE MOVES OVER THE REGION FROM THE WEST. /ALLEN/ && .LONG TERM (FRIDAY THROUGH WEDNESDAY)... AN UNSETTLED PATTERN WILL BE IN PLACE FRIDAY THROUGH NEXT WEEK AS AREA WILL REMAIN IN SW FLOW WITH EMBEDDED IMPULSES TRAVERSING THE REGION. THERE WILL BE A CHANCE OF STRONG TO SEVERE STORMS FRIDAY AND POCKETS OF HEAVY RAIN OVER THE WEEKEND. FOR FRIDAY...THE WEAK BOUNDARY/DRYLINE WILL BE LOCATED OVER THE NORTHERN HALF OF THE REGION LEAVING SOUTHERN LOCATIONS IN A MORE UNSTABLE AIRMASS BY FRIDAY AFTERNOON. THE QUESTION FRIDAY WILL BE HOW MUCH INSTABILITY WILL OCCUR GIVEN CLOUD COVER FROM MID-LEVEL LIFT FROM A MORNING TRAVERSING IMPULSE. GLOBAL MODELS INDICATE RENEWED CONVECTION DURING THE AFTERNOON PER MASS FIELDS WHICH INCREASES CONFIDENCE OF MORE SURFACE BASED ACTIVITY. SUPPORTIVE LAPSE RATES AND SHEAR APPEAR TO BE IN PLACE FOR SOME ISOLATED STRONG TO SEVERE STORMS WITH MORE FAVORED AREA ACROSS WESTERN AND SOUTHERN ZONES. FOR THE WEEKEND...THE BOUNDARY WILL WASH OUT WITH REESTABLISHING SE LOW-LVL FLOW UNDERNEATH CONTINUED ZONAL TO SW FLOW AS EMBEDDED IMPULSES TRAVERSE THE REGION. THESE IMPULSES IN COMBINATION WITH INSTABILITY AND AT LEAST MODEST H5 WIND SPEEDS SHOULD HELP AT LEAST SCATTERED SHOWER AND THUNDERSTORM GENERATION SATURDAY AND SUNDAY AFTERNOON. THESE IMPULSES WILL BE EJECTING AHEAD OF A LARGER CUT-OFF H5 LOW ACROSS NORTHERN MEXICO THAT WILL AID IN SURFACE LOW DEVELOPMENT INTO MONDAY MORNING ACROSS NORTHERN TEXAS. FOR EARLY NEXT WEEK...THE NEGATIVELY TILTED TROUGH FROM THE MAIN LOW WILL PIVOT ACROSS THE REGION AND AID IN LIKELY CONTINUED SHOWER AND THUNDERSTORM ACTIVITY. BOTH GFS AND EC PRECIP RUN ACCUMULATION TOTALS SUGGEST POCKETS OF 4-5 INCHES THROUGH THE END OF NEXT WEEK. TRENDS WILL NEED TO MONITORED EACH DAY FOR POSSIBLE FLOODING CONCERNS IF A MORE CONCENTRATED COMPLEX DEVELOPS. /ALLEN/ && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 69 85 66 77 64 / 20 30 30 50 50 AUSTIN BERGSTROM INTL AIRPORT 68 83 66 77 64 / 20 30 30 50 50 NEW BRAUNFELS MUNI AIRPORT 68 85 67 79 65 / 20 20 10 50 50 BURNET MUNI AIRPORT 66 84 63 74 62 / 30 40 30 50 50 DEL RIO INTL AIRPORT 68 89 69 83 67 / 30 - 20 50 50 GEORGETOWN MUNI AIRPORT 68 84 64 75 63 / 30 40 40 50 50 HONDO MUNI AIRPORT 68 86 68 80 66 / 30 10 10 50 50 SAN MARCOS MUNI AIRPORT 69 84 66 78 65 / 20 20 20 50 50 LA GRANGE - FAYETTE REGIONAL 70 84 69 80 67 / 10 20 20 50 50 SAN ANTONIO INTL AIRPORT 69 85 69 79 66 / 20 10 10 50 50 STINSON MUNI AIRPORT 69 86 69 80 67 / 20 10 10 50 50 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...01 SYNOPTIC/GRIDS...15 PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
331 PM CDT Wed Apr 8 2015 .SHORT TERM... (Tonight and Tomorrow) Initial shortwave has worked itself off to the east and has taken the first round of mainly elevated convection with it. A little more potent shortwave is approaching for late this afternoon and this evening. At the surface, a fairly diffuse dryline extends across the Permian Basin northward into the Panhandle. Much sharper feature to the north where the high clouds have thinned enough to allow much better mixing and a more defined dryline. Morning soundings showed a substantial cap to overcome for surface based convection, and the abundant high clouds limiting sunshine and heating has so far not weakened the cap enough. However, as the shortwave approaches, should see the cap finally weaken enough to see at least scattered convection develop from the Permian Basin north into the South Plains, with the activity spreading into West Central Texas by sunset. How much convection we see is still a question, with the HRRR showing a fairly extensive area of storms while the TTU WRF shows quite a bit less. Given the shear and at least some instability, if storms can develop and get organized, they certainly have the potential to reach severe levels. And given a 50 kt low level jet developing during the evening, storms may be slow to dissipate through the evening and into the early morning hours. Pacific front shifts east into West Central Texas on Thursday, although perhaps not quite clearing the eastern sections by afternoon. May have enough moisture still in place for a few storms to redevelop across areas of a Brownwood to Junction line. .LONG TERM... (Thursday Night through Wednesday) Rain chances will continue Thursday night over southern sections of the forecast where the frontal boundary will be located. The frontal boundary will continue to provide a focus of thunderstorm activity Friday and into the weekend as low level winds return to south and southeasterly allowing isentropic upglide across over the area. The best chance of additional rainfall will be over the southern half of the area. Winds aloft will become southwesterly ahead of an upper level low that will move across the northern Baja Peninsula Saturday night. Periodic disturbances in the flow aloft will keep the chance of thunderstorms over the area through Sunday night. Rain chances will decrease over most of the CWA from west to east on Monday as the Pacific upper low lifts northeast from extreme western Texas to the Central Plains. Residual thunderstorms will still be possible over primarily the southern CWA through Wednesday as a southwestern flow aloft reestablishes ahead of another upper level low digging southeast from the Pacific Northwest to the Central Rockies. Post-frontal afternoon temperatures on Friday will be in the lower 70s across the forecast area after Friday morning lows in 50s. Given the continuation of rainfall chances and good cloud cover through the middle of next week, warm-up will be gradual with upper 70s for Saturday highs, upper 70s and lower 80s on Sunday and Monday, and lower 80s for highs on Tuesday and Wednesday. Morning lows will climb back into the upper 50s to the lower 60s into the middle of next week. 15 && .PRELIMINARY POINT TEMPS/POPS... Abilene 66 86 55 73 60 / 30 5 10 20 40 San Angelo 66 87 57 73 61 / 30 10 10 40 40 Junction 66 85 62 75 62 / 40 20 20 40 50 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
130 PM CDT WED APR 8 2015 .AVIATION... MVFR CIGS WILL GIVE WAY TO VFR CONDITIONS AT SAT/SSF/AUS OVER THE NEXT 2-4 HOURS AS A SHOWER ACTIVITY DUE TO A WEAK DISTURBANCE REMAINS TO THE WEST. DRT CIGS WILL REMAIN BORDERLINE IFR/MVFR FOR A FEW HOURS BEFORE IMPROVING TO BORDERLINE MVFR/VFR WITH SHOWERS MOST LIKELY BETWEEN 22-02Z. TSTMS CANNOT BE RULED OUT AT DRT DURING THIS TIME AS HRRR SUGGESTS...BUT ARE UNLIKELY IF LOW CLOUDS AND SHOWERS CONTINUE UPSTREAM WITHOUT SUFFICIENT CLEARING. EXPECT CIGS TO LOWER AT ALL SITES TO MVFR BY LATE EVENING AND IFR FOR A FEW HOURS BETWEEN 09-15Z BEFORE IMPROVING TO MVFR. LH && .PREV DISCUSSION... /ISSUED 1000 AM CDT WED APR 8 2015/ UPDATE...HAVE INCREASED POPS 10-20% ACROSS THE WESTERN COUNTIES AND SEGMENTED THE MORNING TIME PERIOD INTO THREE HOUR BLOCKS TO BETTER ACCOUNT FOR SHOWER TIMING AND PROGRESSION NORTHEASTWARD. HAVE LOWERED TEMPERATURES OUT WEST GIVEN ADDITIONAL SHOWER COVERAGE AND ASSOCIATED CLOUD COVER. THIS TREND MAY NEED TO BE REVISITED IF HRRR OUTPUT IS AN ACCURATE INDICATION OF SHOWER EVOLUTION TODAY. UPDATES ARE OUT AND UPDATED DISCUSSION CAN BE FOUND BELOW. /ALLEN/ DISCUSSION...ISENTROPIC LIFT IN COMBINATION WITH A MID- TO UPPER- LEVEL DIVERGENCE DUE TO INCREASING WIND SPEEDS ROUNDING THE BASE OF A CLOSED H5 LOW OVER NEVADA IS AIDING ELEVATED SHOWER AND THUNDERSTORM DEVELOPMENT ALONG THE RIO GRANDE. THE 12Z KDRT SOUNDING REVEALED MUCAPE VALUES NEAR 1000-1500 J/KG WITH THE LFC LOCATED NEAR 10 KFT. THIS HEIGHT IS CO-LOCATED WITH MOISTURE LADEN ISENTROPIC UPGLIDE WITHIN THIS LAYER AND THUS SUPPORTING SOME THUNDERSTORM ACTIVITY. THE RAP/HRRR ARE THE MORE AGGRESSIVE SHORT TERM MODELS BUT SO FAR HAVE BEEN MORE CORRECT OVER PAST COUPLE HOURS. HAVE TRENDED THE NEXT 3-12 HOURS THIS DIRECTION AND BUMPED UP POPS ALONG AND WEST OF I-35...ESPECIALLY FOR WESTERN REGIONS AND THE SOUTHERN EDWARDS PLATEAU. A STRONG STORM OR TWO MAY BE POSSIBLE OUT WEST THIS AFTERNOON AND TRENDS WILL NEED MONITORED CLOSELY IF ANOTHER POSSIBLE SHORTWAVE EMBEDDED WITHIN THE INCREASING MID LEVEL FLOW SUPPORTS GREATER COVERAGE LIKE THE HRRR SUGGESTS. SPC SSEO GIVES CONFIDENCE THAT THE WEST IS THE FAVORED REGION FOR STRONGER ACTIVITY BUT THE AMOUNT OF OVERALL PRECIPITATION COVERAGE IS STILL A QUESTION. NOT READY TO FULLY LEAN TOWARDS THE AGGRESSIVE HRRR DIRECTION ON THIS UPDATE BUT WILL MONITOR FOR FUTURE UPDATES. /ALLEN/ PREV DISCUSSION... /ISSUED 651 AM CDT WED APR 8 2015/ AVIATION... MVFR CIGS SHOULD SCATTER OUT FIRST AT KAUS...THEN LATER AT KSAT/KSSF. WINDS WILL BE S-SE AND FAIRLY STEADY AT 10-15 KTS THROUGH THE FORECAST PERIOD...BUT DID INCLUDE SOME HIGHER GUSTS FOR MID TO LATE MORNING. THE ARRIVAL OF A SHORTWAVE TROUGH AND MORE FAVORABLE SURFACE HEATING SHOULD LEAD TO A BETTER CHANCE OF -TSRA AT KDRT...SO INCLUDED THAT AS A PROB30 FOR LATE THIS AFTERNOON AND EARLY EVENING. LOOK FOR MOIST GULF FLOW TO RE- ESTABLISH MVFR...THEN IFR CIGS OVERNIGHT INTO THURSDAY MORNING. PREV DISCUSSION... /ISSUED 357 AM CDT WED APR 8 2015/ SHORT TERM (TODAY THROUGH THURSDAY)... SOUTHERLY LOWER LEVEL FLOW WILL MAINTAIN A MOIST AIRMASS TODAY INTO THURSDAY WITH A PATTERN OF NIGHT AND MORNING STRATUS MIXING OUT IN THE AFTERNOON. AN UPPER LEVEL JET STREAK WILL MOVE ACROSS TEXAS TODAY INTO TONIGHT PUSHING THE DRYLINE EAST ACROSS WESTERN TEXAS. SOME SHOWERS AND THUNDERSTORMS WILL FORM ALONG THE DRYLINE AND OVER THE SERRIANAS DEL BURRO AND THEN MOVE ACROSS THE EDWARDS PLATEAU AND HILL COUNTRY TODAY AND TOWARD THE I-35 CORRIDOR TONIGHT. CAPE VALUES INDICATE SOME STORMS IN THE EDWARDS PLATEAU MAY BE STRONG TO MARGINALLY SEVERE THIS AFTERNOON INTO EVENING. AN UPPER LEVEL TROUGH CURRENTLY OVER THE GREAT BASIN MOVES ACROSS THE NORTHERN PLAINS FORCING THE DRYLINE EAST INTO THE EDWARDS PLATEAU AND POSSIBLY FAR NORTHERN HILL COUNTRY ON THURSDAY. THE MOIST AXIS SHIFTS EAST WITH SHOWERS AND THUNDERSTORMS MAINLY NORTHEAST OF I-10. CAPE VALUES AGAIN INDICATE A POSSIBILITY OF STRONG TO MARGINALLY SEVERE STORMS ON THURSDAY. HOWEVER...A CAPPING INVERSION OF WARM MID LEVEL TEMPERATURES MAY INHIBIT DEVELOPMENT TODAY AND THURSDAY. LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)... THE UPPER LEVEL TROUGH CONTINUES FURTHER TO THE NORTHEAST ACROSS THE GREAT LAKES AND THEN PHASES WITH AN UPPER LEVEL TROUGH OVER SOUTHEASTERN CANADA. THIS FORCES A COLD FRONT INTO SOUTH CENTRAL TEXAS ON FRIDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED ALONG THE FRONT WITH CONVECTIVE PARAMETERS INDICATING A POTENTIAL FOR STRONG TO MARGINALLY SEVERE STORMS. AGAIN...THIS DEPENDS ON THE AMOUNT OF INSTABILITY AND THE BREAKING OF THE CAPPING INVERSION. THE FRONT STALLS JUST SOUTH OF SOUTH CENTRAL TEXAS FRIDAY NIGHT AND THEN DISSIPATES SATURDAY AS AN UPPER LEVEL TROUGH CURRENTLY OVER JUST SOUTH OF THE GULF OF ALASKA MOVES INTO NORTHWESTERN MEXICO. THIS TROUGH MOVES ACROSS TEXAS ON MONDAY WHILE FORCING A PACIFIC FRONT OR A DRYLINE INTO WESTERN PARTS OF SOUTH CENTRAL TEXAS. HOWEVER...THERE IS SOME UNCERTAINTY ON ITS SPEED SINCE IT HAS NOT YET BEEN SAMPLED BY THE NORTH AMERICAN UPPER AIR OBSERVATION NETWORK. WILL MAINTAIN SHOWERS AND THUNDERSTORMS THIS WEEKEND ENDING FROM WEST TO EAST ON MONDAY AS THE TROUGH MOVES EAST OF OUR AREA. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 68 85 66 77 64 / 20 30 30 50 50 AUSTIN BERGSTROM INTL AIRPORT 69 83 66 77 64 / 20 30 30 50 50 NEW BRAUNFELS MUNI AIRPORT 68 85 67 79 65 / 20 20 20 50 50 BURNET MUNI AIRPORT 66 84 63 74 62 / 30 30 40 50 50 DEL RIO INTL AIRPORT 67 89 69 83 67 / 30 - 20 50 50 GEORGETOWN MUNI AIRPORT 67 84 64 75 63 / 30 30 40 50 50 HONDO MUNI AIRPORT 68 86 68 80 66 / 30 10 10 50 50 SAN MARCOS MUNI AIRPORT 68 84 66 78 65 / 20 20 20 50 50 LA GRANGE - FAYETTE REGIONAL 71 84 69 80 67 / 10 20 20 50 50 SAN ANTONIO INTL AIRPORT 69 85 69 79 66 / 20 10 20 50 50 STINSON MUNI AIRPORT 69 86 69 80 67 / 20 10 10 50 50 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...00 SYNOPTIC/GRIDS...15 PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1242 PM CDT Wed Apr 8 2015 .AVIATION... /18Z TAFS/ Scattered showers and storms continue near West Central Texas terminals this afternoon and tonight. Most of this first wave will exit the are by mid afternoon, leaving VFR conditions for much of the afternoon and evening. Stronger storms are possible later this afternoon and evening, but the activity should be more isolated and the exact timing is still a question. Will include a VCTS at KABI (Abilene) for this time period, but will hold off on mentioning any drop in visibility or ceiling for now. MVFR cigs move back in overnight as low level moisture streams back into the area. && .PREV DISCUSSION... /ISSUED 807 AM CDT WED APR 8 2015/ AVIATION... /12Z TAFS/ Good flight conditions will prevail at KABI, KSJT, and KBBD through the next 24 hours. Farther south, ceilings near 1500 feet this morning will lift to around 4000 feet by late morning. Southwest wind gusts near 25 kts are likely late this morning and afternoon at all terminals. These wind gusts will diminish to near 20 kts after sunset. Showers and thunderstorms may develop this afternoon/evening. However, confidence in timing/location remain high enough not to include in the TAFs at this time. PREV DISCUSSION... /ISSUED 458 AM CDT Wed Apr 8 2015/ SHORT TERM... (Today and Tonight) .Severe weather possible this afternoon/evening... The forecast challenges are plentiful through the next 24 hours. The TTU WRF and HRRR models indicate showers should be developing to our southwest at 4 AM, moving into the region from west to east this morning through mid-afternoon. They then try to re-develop convection to our west by late afternoon, with this convection dissipating before midnight as it approaches our western counties. Conversely, the NAM/GFS/ECMWF all show nothing for this morning through mid afternoon, and then develop convection from mid- afternoon through midnight at varying locations/intensities across the region. Given the current satellite imagery and upstream observations, we`ll lean more towards this scenario. The NAM/GFS have also trended significantly farther west with the dryline position this afternoon. The ECMWF brings it farther east with it positioned along a line from eastern Haskell County, to San Angelo, to west of Ozona. We`ll take a middle-ground approach with the expectation of the dryline halting its eastward progression, being located along the western edge of the forecast area. A strong cap will remain in place for much of the day. By late afternoon/early evening, a mid-level jet streak will approach the area from the southwest. Increasing ascent from this, afternoon mixing, and convergence along the dryline, may be sufficient to weaken the cap enough for a few storms to develop. If this occurs, the environment will be characterized by 1500-2500 J/kg of SBCAPE (possibly more if skies are less cloudy than currently forecast), steep mid-level lapse rates near 8 C/km, with 0-6km effective shear values of 40-55 kts. With this type of setup, storms would rapidly become severe/supercells with large hail and damaging winds the main concerns. Soundings also show low-level winds backing to the southeast, which really increases 0-3km helicity values making isolated tornadoes a possibility as well, especially across the northwestern this of the area which is closer to the track of the mid-level disturbance. LONG TERM... (Thursday through Tuesday) Rain chances remain in most periods of the long term. Another cold front will push across West Central Texas on Thursday and bring cooler air, and it will enhance the rain potential for Friday through the weekend. A developing upper-level disturbance well to our west will also enhance the rain potential by creating southwest flow aloft, where embedded minor disturbance will move across Texas. Isentropic upglide will be best across our southern counties from Friday through the weekend. Thus, the best chance for rain will be there. The ECMWF is more aggressive than the GFS regarding QPF amounts for Friday through the weekend, and the ECMWF indicates better divergence aloft over Texas for those periods. So, continuing the best rain chances across our southern counties looks best. Plus, continuing a PoP forecast closer to the ECMWF looks better than something closer to the drier GFS. && .PRELIMINARY POINT TEMPS/POPS... Abilene 84 65 86 55 73 / 50 40 5 10 30 San Angelo 84 65 86 57 73 / 40 40 10 10 30 Junction 83 64 87 62 75 / 40 30 30 10 40 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1000 AM CDT WED APR 8 2015 .UPDATE...HAVE INCREASED POPS 10-20% ACROSS THE WESTERN COUNTIES AND SEGMENTED THE MORNING TIME PERIOD INTO THREE HOUR BLOCKS TO BETTER ACCOUNT FOR SHOWER TIMING AND PROGRESSION NORTHEASTWARD. HAVE LOWERED TEMPERATURES OUT WEST GIVEN ADDITIONAL SHOWER COVERAGE AND ASSOCIATED CLOUD COVER. THIS TREND MAY NEED TO BE REVISITED IF HRRR OUTPUT IS AN ACCURATE INDICATION OF SHOWER EVOLUTION TODAY. UPDATES ARE OUT AND UPDATED DISCUSSION CAN BE FOUND BELOW. /ALLEN/ && .DISCUSSION...ISENTROPIC LIFT IN COMBINATION WITH A MID- TO UPPER- LEVEL DIVERGENCE DUE TO INCREASING WIND SPEEDS ROUNDING THE BASE OF A CLOSED H5 LOW OVER NEVADA IS AIDING ELEVATED SHOWER AND THUNDERSTORM DEVELOPMENT ALONG THE RIO GRANDE. THE 12Z KDRT SOUNDING REVEALED MUCAPE VALUES NEAR 1000-1500 J/KG WITH THE LFC LOCATED NEAR 10 KFT. THIS HEIGHT IS CO-LOCATED WITH MOISTURE LADEN ISENTROPIC UPGLIDE WITHIN THIS LAYER AND THUS SUPPORTING SOME THUNDERSTORM ACTIVITY. THE RAP/HRRR ARE THE MORE AGGRESSIVE SHORT TERM MODELS BUT SO FAR HAVE BEEN MORE CORRECT OVER PAST COUPLE HOURS. HAVE TRENDED THE NEXT 3-12 HOURS THIS DIRECTION AND BUMPED UP POPS ALONG AND WEST OF I-35...ESPECIALLY FOR WESTERN REGIONS AND THE SOUTHERN EDWARDS PLATEAU. A STRONG STORM OR TWO MAY BE POSSIBLE OUT WEST THIS AFTERNOON AND TRENDS WILL NEED MONITORED CLOSELY IF ANOTHER POSSIBLE SHORTWAVE EMBEDDED WITHIN THE INCREASING MID LEVEL FLOW SUPPORTS GREATER COVERAGE LIKE THE HRRR SUGGESTS. SPC SSEO GIVES CONFIDENCE THAT THE WEST IS THE FAVORED REGION FOR STRONGER ACTIVITY BUT THE AMOUNT OF OVERALL PRECIPITATION COVERAGE IS STILL A QUESTION. NOT READY TO FULLY LEAN TOWARDS THE AGGRESSIVE HRRR DIRECTION ON THIS UPDATE BUT WILL MONITOR FOR FUTURE UPDATES. /ALLEN/ && .PREV DISCUSSION... /ISSUED 651 AM CDT WED APR 8 2015/ AVIATION... MVFR CIGS SHOULD SCATTER OUT FIRST AT KAUS...THEN LATER AT KSAT/KSSF. WINDS WILL BE S-SE AND FAIRLY STEADY AT 10-15 KTS THROUGH THE FORECAST PERIOD...BUT DID INCLUDE SOME HIGHER GUSTS FOR MID TO LATE MORNING. THE ARRIVAL OF A SHORTWAVE TROUGH AND MORE FAVORABLE SURFACE HEATING SHOULD LEAD TO A BETTER CHANCE OF -TSRA AT KDRT...SO INCLUDED THAT AS A PROB30 FOR LATE THIS AFTERNOON AND EARLY EVENING. LOOK FOR MOIST GULF FLOW TO RE- ESTABLISH MVFR...THEN IFR CIGS OVERNIGHT INTO THURSDAY MORNING. PREV DISCUSSION... /ISSUED 357 AM CDT WED APR 8 2015/ SHORT TERM (TODAY THROUGH THURSDAY)... SOUTHERLY LOWER LEVEL FLOW WILL MAINTAIN A MOIST AIRMASS TODAY INTO THURSDAY WITH A PATTERN OF NIGHT AND MORNING STRATUS MIXING OUT IN THE AFTERNOON. AN UPPER LEVEL JET STREAK WILL MOVE ACROSS TEXAS TODAY INTO TONIGHT PUSHING THE DRYLINE EAST ACROSS WESTERN TEXAS. SOME SHOWERS AND THUNDERSTORMS WILL FORM ALONG THE DRYLINE AND OVER THE SERRIANAS DEL BURRO AND THEN MOVE ACROSS THE EDWARDS PLATEAU AND HILL COUNTRY TODAY AND TOWARD THE I-35 CORRIDOR TONIGHT. CAPE VALUES INDICATE SOME STORMS IN THE EDWARDS PLATEAU MAY BE STRONG TO MARGINALLY SEVERE THIS AFTERNOON INTO EVENING. AN UPPER LEVEL TROUGH CURRENTLY OVER THE GREAT BASIN MOVES ACROSS THE NORTHERN PLAINS FORCING THE DRYLINE EAST INTO THE EDWARDS PLATEAU AND POSSIBLY FAR NORTHERN HILL COUNTRY ON THURSDAY. THE MOIST AXIS SHIFTS EAST WITH SHOWERS AND THUNDERSTORMS MAINLY NORTHEAST OF I-10. CAPE VALUES AGAIN INDICATE A POSSIBILITY OF STRONG TO MARGINALLY SEVERE STORMS ON THURSDAY. HOWEVER...A CAPPING INVERSION OF WARM MID LEVEL TEMPERATURES MAY INHIBIT DEVELOPMENT TODAY AND THURSDAY. LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)... THE UPPER LEVEL TROUGH CONTINUES FURTHER TO THE NORTHEAST ACROSS THE GREAT LAKES AND THEN PHASES WITH AN UPPER LEVEL TROUGH OVER SOUTHEASTERN CANADA. THIS FORCES A COLD FRONT INTO SOUTH CENTRAL TEXAS ON FRIDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED ALONG THE FRONT WITH CONVECTIVE PARAMETERS INDICATING A POTENTIAL FOR STRONG TO MARGINALLY SEVERE STORMS. AGAIN...THIS DEPENDS ON THE AMOUNT OF INSTABILITY AND THE BREAKING OF THE CAPPING INVERSION. THE FRONT STALLS JUST SOUTH OF SOUTH CENTRAL TEXAS FRIDAY NIGHT AND THEN DISSIPATES SATURDAY AS AN UPPER LEVEL TROUGH CURRENTLY OVER JUST SOUTH OF THE GULF OF ALASKA MOVES INTO NORTHWESTERN MEXICO. THIS TROUGH MOVES ACROSS TEXAS ON MONDAY WHILE FORCING A PACIFIC FRONT OR A DRYLINE INTO WESTERN PARTS OF SOUTH CENTRAL TEXAS. HOWEVER...THERE IS SOME UNCERTAINTY ON ITS SPEED SINCE IT HAS NOT YET BEEN SAMPLED BY THE NORTH AMERICAN UPPER AIR OBSERVATION NETWORK. WILL MAINTAIN SHOWERS AND THUNDERSTORMS THIS WEEKEND ENDING FROM WEST TO EAST ON MONDAY AS THE TROUGH MOVES EAST OF OUR AREA. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 83 69 85 66 79 / 20 20 30 30 50 AUSTIN BERGSTROM INTL AIRPORT 84 69 83 66 78 / 20 20 30 30 50 NEW BRAUNFELS MUNI AIRPORT 86 68 86 66 81 / 10 20 20 20 50 BURNET MUNI AIRPORT 82 67 85 64 75 / 30 40 30 30 50 DEL RIO INTL AIRPORT 84 68 90 68 83 / 40 40 - 20 60 GEORGETOWN MUNI AIRPORT 83 68 84 65 75 / 20 20 30 40 50 HONDO MUNI AIRPORT 86 68 87 67 81 / 20 30 10 10 50 SAN MARCOS MUNI AIRPORT 82 69 85 66 80 / 10 20 30 20 50 LA GRANGE - FAYETTE REGIONAL 84 70 84 69 81 / - 10 30 20 50 SAN ANTONIO INTL AIRPORT 86 70 86 67 80 / 20 20 20 10 50 STINSON MUNI AIRPORT 87 69 86 68 81 / 10 20 20 10 50 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...01 SYNOPTIC/GRIDS...15 PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
930 AM CDT WED APR 8 2015 .UPDATE...HAVE INCREASED POPS 10-20% ACROSS THE WESTERN COUNTIES AND SEGMENTED THE MORNING TIME PERIOD INTO THREE HOUR BLOCKS TO BETTER ACCOUNT FOR SHOWER TIMING AND PROGRESSION NORTHEASTWARD. HAVE LOWERED TEMPERATURES OUT WEST GIVEN ADDITIONAL SHOWER COVERAGE AND ASSOCIATED CLOUD COVER. THIS TREND MAY NEED TO BE REVISITED IF HRRR OUTPUT IS AN ACCURATE INDICATION OF SHOWER EVOLUTION TODAY. UPDATES ARE OUT AND UPDATED DISCUSSION CAN BE FOUND BELOW. /ALLEN/ && .DISCUSSION...ISENTROPIC LIFT IN COMBINATION WITH A MID- TO UPPER- LEVEL DIVERGENCE DUE TO INCREASING WIND SPEEDS ROUNDING THE BASE OF A CLOSED H5 LOW OVER NEVADA IS AIDING ELEVATED SHOWER AND THUNDERSTORM DEVELOPMENT ALONG THE RIO GRANDE. THE 12Z KDRT SOUNDING REVEALED MUCAPE VALUES NEAR 1500 J/KG WITH THE LFC LOCATED NEAR 10 KFT. THIS HEIGHT IS CO-LOCATED WITH MOISTURE LADEN ISENTROPIC UPGLIDE WITHIN THIS LAYER AND THUS SUPPORTING SOME THUNDERSTORM ACTIVITY. THE RAP/HRRR ARE THE MORE AGGRESSIVE SHORT TERM MODELS BUT SO FAR HAVE BEEN MORE CORRECT OVER PAST COUPLE HOURS. HAVE TRENDED THE NEXT 3-12 HOURS THIS DIRECTION AND BUMPED UP POPS ALONG AND WEST OF I-35...ESPECIALLY FOR WESTERN REGIONS AND THE SOUTHERN EDWARDS PLATEAU. A STRONG STORM OR TWO MAY BE POSSIBLE OUT WEST THIS AFTERNOON AND TRENDS WILL NEED MONITORED CLOSELY IF ANOTHER POSSIBLE SHORTWAVE EMBEDDED WITHIN THE INCREASING MID LEVEL FLOW SUPPORTS GREATER COVERAGE LIKE THE HRRR SUGGESTS. SPC SSEO GIVES CONFIDENCE THAT THE WEST IS THE FAVORED REGION FOR STRONGER ACTIVITY BUT THE AMOUNT OF OVERALL PRECIPITATION COVERAGE IS STILL A QUESTION. NOT READY TO FULLY LEAN TOWARDS THE AGGRESSIVE HRRR DIRECTION ON THIS UPDATE BUT WILL MONITOR FOR FUTURE UPDATES. /ALLEN/ && .PREV DISCUSSION... /ISSUED 651 AM CDT WED APR 8 2015/ AVIATION... MVFR CIGS SHOULD SCATTER OUT FIRST AT KAUS...THEN LATER AT KSAT/KSSF. WINDS WILL BE S-SE AND FAIRLY STEADY AT 10-15 KTS THROUGH THE FORECAST PERIOD...BUT DID INCLUDE SOME HIGHER GUSTS FOR MID TO LATE MORNING. THE ARRIVAL OF A SHORTWAVE TROUGH AND MORE FAVORABLE SURFACE HEATING SHOULD LEAD TO A BETTER CHANCE OF -TSRA AT KDRT...SO INCLUDED THAT AS A PROB30 FOR LATE THIS AFTERNOON AND EARLY EVENING. LOOK FOR MOIST GULF FLOW TO RE- ESTABLISH MVFR...THEN IFR CIGS OVERNIGHT INTO THURSDAY MORNING. PREV DISCUSSION... /ISSUED 357 AM CDT WED APR 8 2015/ SHORT TERM (TODAY THROUGH THURSDAY)... SOUTHERLY LOWER LEVEL FLOW WILL MAINTAIN A MOIST AIRMASS TODAY INTO THURSDAY WITH A PATTERN OF NIGHT AND MORNING STRATUS MIXING OUT IN THE AFTERNOON. AN UPPER LEVEL JET STREAK WILL MOVE ACROSS TEXAS TODAY INTO TONIGHT PUSHING THE DRYLINE EAST ACROSS WESTERN TEXAS. SOME SHOWERS AND THUNDERSTORMS WILL FORM ALONG THE DRYLINE AND OVER THE SERRIANAS DEL BURRO AND THEN MOVE ACROSS THE EDWARDS PLATEAU AND HILL COUNTRY TODAY AND TOWARD THE I-35 CORRIDOR TONIGHT. CAPE VALUES INDICATE SOME STORMS IN THE EDWARDS PLATEAU MAY BE STRONG TO MARGINALLY SEVERE THIS AFTERNOON INTO EVENING. AN UPPER LEVEL TROUGH CURRENTLY OVER THE GREAT BASIN MOVES ACROSS THE NORTHERN PLAINS FORCING THE DRYLINE EAST INTO THE EDWARDS PLATEAU AND POSSIBLY FAR NORTHERN HILL COUNTRY ON THURSDAY. THE MOIST AXIS SHIFTS EAST WITH SHOWERS AND THUNDERSTORMS MAINLY NORTHEAST OF I-10. CAPE VALUES AGAIN INDICATE A POSSIBILITY OF STRONG TO MARGINALLY SEVERE STORMS ON THURSDAY. HOWEVER...A CAPPING INVERSION OF WARM MID LEVEL TEMPERATURES MAY INHIBIT DEVELOPMENT TODAY AND THURSDAY. LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)... THE UPPER LEVEL TROUGH CONTINUES FURTHER TO THE NORTHEAST ACROSS THE GREAT LAKES AND THEN PHASES WITH AN UPPER LEVEL TROUGH OVER SOUTHEASTERN CANADA. THIS FORCES A COLD FRONT INTO SOUTH CENTRAL TEXAS ON FRIDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED ALONG THE FRONT WITH CONVECTIVE PARAMETERS INDICATING A POTENTIAL FOR STRONG TO MARGINALLY SEVERE STORMS. AGAIN...THIS DEPENDS ON THE AMOUNT OF INSTABILITY AND THE BREAKING OF THE CAPPING INVERSION. THE FRONT STALLS JUST SOUTH OF SOUTH CENTRAL TEXAS FRIDAY NIGHT AND THEN DISSIPATES SATURDAY AS AN UPPER LEVEL TROUGH CURRENTLY OVER JUST SOUTH OF THE GULF OF ALASKA MOVES INTO NORTHWESTERN MEXICO. THIS TROUGH MOVES ACROSS TEXAS ON MONDAY WHILE FORCING A PACIFIC FRONT OR A DRYLINE INTO WESTERN PARTS OF SOUTH CENTRAL TEXAS. HOWEVER...THERE IS SOME UNCERTAINTY ON ITS SPEED SINCE IT HAS NOT YET BEEN SAMPLED BY THE NORTH AMERICAN UPPER AIR OBSERVATION NETWORK. WILL MAINTAIN SHOWERS AND THUNDERSTORMS THIS WEEKEND ENDING FROM WEST TO EAST ON MONDAY AS THE TROUGH MOVES EAST OF OUR AREA. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 83 69 85 66 79 / 20 20 30 30 50 AUSTIN BERGSTROM INTL AIRPORT 84 69 83 66 78 / 20 20 30 30 50 NEW BRAUNFELS MUNI AIRPORT 86 68 86 66 81 / 10 20 20 20 50 BURNET MUNI AIRPORT 82 67 85 64 75 / 30 40 30 30 50 DEL RIO INTL AIRPORT 84 68 90 68 83 / 40 40 - 20 60 GEORGETOWN MUNI AIRPORT 83 68 84 65 75 / 20 20 30 40 50 HONDO MUNI AIRPORT 86 68 87 67 81 / 20 30 10 10 50 SAN MARCOS MUNI AIRPORT 82 69 85 66 80 / 10 20 30 20 50 LA GRANGE - FAYETTE REGIONAL 84 70 84 69 81 / - 10 30 20 50 SAN ANTONIO INTL AIRPORT 86 70 86 67 80 / 20 20 20 10 50 STINSON MUNI AIRPORT 87 69 86 68 81 / 10 20 20 10 50 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...01 SYNOPTIC/GRIDS...15 PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION...CORRECTED
NWS SAN ANGELO TX
807 AM CDT WED APR 8 2015 .AVIATION... /12Z TAFS/ Good flight conditions will prevail at KABI, KSJT, and KBBD through the next 24 hours. Farther south, ceilings near 1500 feet this morning will lift to around 4000 feet by late morning. Southwest wind gusts near 25 kts are likely late this morning and afternoon at all terminals. These wind gusts will diminish to near 20 kts after sunset. Showers and thunderstorms may develop this afternoon/evening. However, confidence in timing/location remain high enough not to include in the TAFs at this time. && .PREV DISCUSSION... /ISSUED 458 AM CDT Wed Apr 8 2015/ SHORT TERM... (Today and Tonight) ..Severe weather possible this afternoon/evening... The forecast challenges are plentiful through the next 24 hours. The TTU WRF and HRRR models indicate showers should be developing to our southwest at 4 AM, moving into the region from west to east this morning through mid-afternoon. They then try to re-develop convection to our west by late afternoon, with this convection dissipating before midnight as it approaches our western counties. Conversely, the NAM/GFS/ECMWF all show nothing for this morning through mid afternoon, and then develop convection from mid- afternoon through midnight at varying locations/intensities across the region. Given the current satellite imagery and upstream observations, we`ll lean more towards this scenario. The NAM/GFS have also trended significantly farther west with the dryline position this afternoon. The ECMWF brings it farther east with it positioned along a line from eastern Haskell County, to San Angelo, to west of Ozona. We`ll take a middle-ground approach with the expectation of the dryline halting its eastward progression, being located along the western edge of the forecast area. A strong cap will remain in place for much of the day. By late afternoon/early evening, a mid-level jet streak will approach the area from the southwest. Increasing ascent from this, afternoon mixing, and convergence along the dryline, may be sufficient to weaken the cap enough for a few storms to develop. If this occurs, the environment will be characterized by 1500-2500 J/kg of SBCAPE (possibly more if skies are less cloudy than currently forecast), steep mid-level lapse rates near 8 C/km, with 0-6km effective shear values of 40-55 kts. With this type of setup, storms would rapidly become severe/supercells with large hail and damaging winds the main concerns. Soundings also show low-level winds backing to the southeast, which really increases 0-3km helicity values making isolated tornadoes a possibility as well, especially across the northwestern this of the area which is closer to the track of the mid-level disturbance. LONG TERM... (Thursday through Tuesday) Rain chances remain in most periods of the long term. Another cold front will push across West Central Texas on Thursday and bring cooler air, and it will enhance the rain potential for Friday through the weekend. A developing upper-level disturbance well to our west will also enhance the rain potential by creating southwest flow aloft, where embedded minor disturbance will move across Texas. Isentropic upglide will be best across our southern counties from Friday through the weekend. Thus, the best chance for rain will be there. The ECMWF is more aggressive than the GFS regarding QPF amounts for Friday through the weekend, and the ECMWF indicates better divergence aloft over Texas for those periods. So, continuing the best rain chances across our southern counties looks best. Plus, continuing a PoP forecast closer to the ECMWF looks better than something closer to the drier GFS. && .PRELIMINARY POINT TEMPS/POPS... Abilene 84 65 86 55 73 / 30 40 5 10 20 San Angelo 84 65 86 57 74 / 40 40 10 10 40 Junction 83 64 87 61 75 / 30 30 30 10 50 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ Aviation: Doll
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
6423 AM CDT WED APR 8 2015 .AVIATION... /12Z TAFS/ Good flight conditions will prevail at KABI, KSJT, and KBBD through the next 24 hours. Farther south, ceilings near 1500 feet this morning will lift to around 4000 feet by late morning. Southwest wind gusts near 25 kts are likely late this morning and afternoon at all terminals. These wind gusts will diminish to near 20 kts after sunset. Showers and thunderstorms may develop this afternoon/evening. However, confidence in timing/location remain high enough not to include in the TAFs at this time. && .PREV DISCUSSION... /ISSUED 458 AM CDT Wed Apr 8 2015/ SHORT TERM... (Today and Tonight) ..Severe weather possible this afternoon/evening... The forecast challenges are plentiful through the next 24 hours. The TTU WRF and HRRR models indicate showers should be developing to our southwest at 4 AM, moving into the region from west to east this morning through mid-afternoon. They then try to re-develop convection to our west by late afternoon, with this convection dissipating before midnight as it approaches our western counties. Conversely, the NAM/GFS/ECMWF all show nothing for this morning through mid afternoon, and then develop convection from mid- afternoon through midnight at varying locations/intensities across the region. Given the current satellite imagery and upstream observations, we`ll lean more towards this scenario. The NAM/GFS have also trended significantly farther west with the dryline position this afternoon. The ECMWF brings it farther east with it positioned along a line from eastern Haskell County, to San Angelo, to west of Ozona. We`ll take a middle-ground approach with the expectation of the dryline halting its eastward progression, being located along the western edge of the forecast area. A strong cap will remain in place for much of the day. By late afternoon/early evening, a mid-level jet streak will approach the area from the southwest. Increasing ascent from this, afternoon mixing, and convergence along the dryline, may be sufficient to weaken the cap enough for a few storms to develop. If this occurs, the environment will be characterized by 1500-2500 J/kg of SBCAPE (possibly more if skies are less cloudy than currently forecast), steep mid-level lapse rates near 8 C/km, with 0-6km effective shear values of 40-55 kts. With this type of setup, storms would rapidly become severe/supercells with large hail and damaging winds the main concerns. Soundings also show low-level winds backing to the southeast, which really increases 0-3km helicity values making isolated tornadoes a possibility as well, especially across the northwestern this of the area which is closer to the track of the mid-level disturbance. LONG TERM... (Thursday through Tuesday) Rain chances remain in most periods of the long term. Another cold front will push across West Central Texas on Thursday and bring cooler air, and it will enhance the rain potential for Friday through the weekend. A developing upper-level disturbance well to our west will also enhance the rain potential by creating southwest flow aloft, where embedded minor disturbance will move across Texas. Isentropic upglide will be best across our southern counties from Friday through the weekend. Thus, the best chance for rain will be there. The ECMWF is more aggressive than the GFS regarding QPF amounts for Friday through the weekend, and the ECMWF indicates better divergence aloft over Texas for those periods. So, continuing the best rain chances across our southern counties looks best. Plus, continuing a PoP forecast closer to the ECMWF looks better than something closer to the drier GFS. && .PRELIMINARY POINT TEMPS/POPS... Abilene 84 65 86 55 73 / 30 40 5 10 20 San Angelo 84 65 86 57 74 / 40 40 10 10 40 Junction 83 64 87 61 75 / 30 30 30 10 50 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ Aviation: Doll
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
458 AM CDT Wed Apr 8 2015 .SHORT TERM... (Today and Tonight) ...Severe weather possible this afternoon/evening... The forecast challenges are plentiful through the next 24 hours. The TTU WRF and HRRR models indicate showers should be developing to our southwest at 4 AM, moving into the region from west to east this morning through mid-afternoon. They then try to re-develop convection to our west by late afternoon, with this convection dissipating before midnight as it approaches our western counties. Conversely, the NAM/GFS/ECMWF all show nothing for this morning through mid afternoon, and then develop convection from mid- afternoon through midnight at varying locations/intensities across the region. Given the current satellite imagery and upstream observations, we`ll lean more towards this scenario. The NAM/GFS have also trended significantly farther west with the dryline position this afternoon. The ECMWF brings it farther east with it positioned along a line from eastern Haskell County, to San Angelo, to west of Ozona. We`ll take a middle-ground approach with the expectation of the dryline halting its eastward progression, being located along the western edge of the forecast area. A strong cap will remain in place for much of the day. By late afternoon/early evening, a mid-level jet streak will approach the area from the southwest. Increasing ascent from this, afternoon mixing, and convergence along the dryline, may be sufficient to weaken the cap enough for a few storms to develop. If this occurs, the environment will be characterized by 1500-2500 J/kg of SBCAPE (possibly more if skies are less cloudy than currently forecast), steep mid-level lapse rates near 8 C/km, with 0-6km effective shear values of 40-55 kts. With this type of setup, storms would rapidly become severe/supercells with large hail and damaging winds the main concerns. Soundings also show low-level winds backing to the southeast, which really increases 0-3km helicity values making isolated tornadoes a possibility as well, especially across the northwestern this of the area which is closer to the track of the mid-level disturbance. .LONG TERM... (Thursday through Tuesday) Rain chances remain in most periods of the long term. Another cold front will push across West Central Texas on Thursday and bring cooler air, and it will enhance the rain potential for Friday through the weekend. A developing upper-level disturbance well to our west will also enhance the rain potential by creating southwest flow aloft, where embedded minor disturbance will move across Texas. Isentropic upglide will be best across our southern counties from Friday through the weekend. Thus, the best chance for rain will be there. The ECMWF is more aggressive than the GFS regarding QPF amounts for Friday through the weekend, and the ECMWF indicates better divergence aloft over Texas for those periods. So, continuing the best rain chances across our southern counties looks best. Plus, continuing a PoP forecast closer to the ECMWF looks better than something closer to the drier GFS. && .PRELIMINARY POINT TEMPS/POPS... Abilene 84 65 86 55 73 / 30 40 5 10 20 San Angelo 84 65 86 57 74 / 40 40 10 10 40 Junction 83 64 87 61 75 / 30 30 30 10 50 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ Doll/Huber
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
101 AM CDT WED APR 8 2015 .AVIATION... MVFR CIGS WILL DIP DOWN INTO IFR AFTER 08-09Z FOR THE I-35 TAF SITES...BUT LATER TOWARD 13Z AT KDRT. THEN LOOK FOR CIGS TO LIFT BACK INTO MVFR BY 18Z...THEN BECOME SCT BY 20Z. WINDS WILL BE S-SE AND FAIRLY STEADY AT 10-15 KTS THROUGH THE FORECAST PERIOD. && .PREV DISCUSSION... /ISSUED 703 PM CDT TUE APR 7 2015/ AVIATION... /00Z TAF UPDATE/ CONVECTION OVER MEXICO IS NOT ACCOUNTED FOR IN THE DRT IN THIS TAF UPDATE AS MOST OF THE MODEL DATA SHOWS LITTLE OR NO ACTIVITY LATER THIS EVENING. AN OUTLIER IS THE HRRR WHICH SHOWS A SMALL COMPLEX DEVELOP AND POSSIBLY IMPACT AREAS ALONG THE RIO GRANDE LATE TONIGHT. MODEL GUIDANCE SUGGESTS MVFR CIGS WILL ARRIVE BY MIDNIGHT AGAIN AND LOWERS BOTH CIGS AND VSBYS INTO IFR CATEGORIES EARLY WEDNESDAY. WILL LEAN ON PERSISTENCE TO KEEP VSBYS A BIT HIGHER. AS WITH TODAY...MUCH OF THE DAY WEDNESDAY SKIES SHOULD BE FILLED WITH AN MVFR CIG. WINDS SHOULD ALSO FOLLOW A DIURNAL PERSISTENCE TREND. PREV DISCUSSION... /ISSUED 310 PM CDT TUE APR 7 2015/ SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...STRATOCU HAS BEEN SLOWER TO ERODE ALONG THE RIO GRANDE THAN EXPECTED THIS AFTERNOON...BUT SHOULD EVENTUALLY SCATTER OUT THROUGH THE LATE AFTERNOON HOURS. ISOLATED CONVECTION BEGINNING TO DEVELOP ALONG THE HIGHER TERRAIN IN MEXICO. CAN NOT RULE AN ISOLATED STORM CROSSING INTO VAL VERDE COUNTY EARLY THIS EVENING...BUT CAP MAY HOLD...ESPECIALLY GIVEN AFOREMENTIONED CLOUDS THAT WERE SLOW TO ERODE. STRATUS RE-DEVELOPS OVERNIGHT AND SCATTERS TOMORROW AFTERNOON SIMILAR TO TODAY. OTHERWISE WARM AND BREEZY TOMORROW. THE DRY LINE ADVANCES SLIGHTLY FARTHER EAST THURSDAY AFTERNOON... AND WITH WEAK MID LEVEL DISTURBANCE THE CAP DOES ERODE LATE AFTERNOON ACROSS THE FAR WESTERN AREAS. COULD SEE ISOLATED STORMS DEVELOPING OVER THE FAR NORTHERN HILL COUNTRY AND EDWARDS PLATEAU TOMORROW AFTERNOON ADVANCING SOUTHEAST INTO THE SOUTHERN HILL COUNTRY TOMORROW EVENING. AT THE MOMENT UNSURE IF STORMS WILL HOLD TOGETHER INTO THE I-35 CORRIDOR LATE EVENING GIVEN THE CAP. CAN NOT RULE OUT THE POSSIBILITY OF A STRONG STORM OR TWO TOMORROW AFTERNOON AND EVENING...ESPECIALLY CLOSER TO THE RIO GRANDE. LONG TERM (THURSDAY THROUGH TUESDAY)...THE DRY LINE ADVANCES ALL THE WAY INTO VAL VERDE COUNTY ON THURSDAY AFTERNOON....WITH THE MOIST LOW LEVEL THETA-E RIDGE ALONG AND EAST OF I-35. ANOTHER MID LEVEL SHORTWAVE AND COOLING HELPS TO ERODE CAP FARTHER INTO THE CENTRAL AND EASTERN CWA. THE BETTER CHANCES FOR CONVECTION THURSDAY WILL BE ALONG AND NORTH OF A FREDERICKSBURG TO SAN MARCOS TO LA GRANGE LINE. A FEW STRONGER STORMS WILL BE POSSIBLE ALONG AND NORTH OF THIS LINE. A WEAK COLD FRONT ENTERS THE AREA EARLY FRIDAY MORNING...STALLING ALONG OR NORTH OF I-10...THEN LIFTING BACK TO THE NORTH FRIDAY AFTERNOON AND EVENING. MOISTURE POOLING WILL BE BEST ACROSS THE WESTERN CWA...COINCIDING WITH BROAD LOW LEVEL CONVERGENCE AXIS. SCATTERED POPS ARE FORECAST FOR THE ENTIRE...BUT BEST CHANCES WILL BE OUT WEST. BOTH THE ECMWF AND GFS SHOW 700MB SHORTWAVE AND MOISTURE POOL MOVING NORTHEAST THROUGH THE EDWARDS PLATEAU AND NORTHERN HILL COUNTRY ON FRIDAY. FORECAST SOUNDINGS INDICANT DEEP LAYER SHEAR AND INSTABILITY WILL BE SUFFICIENT FOR A FEW STRONG TO SEVERE STORMS FRIDAY ALONG THE RIO GRANDE...EDWARDS PLATEAU AND HILL COUNTRY. DO MAINTAIN POPS INTO SATURDAY GIVEN THE MOISTURE POOL OVER THE AREA...BUT LACK OF SIGNIFICANT FORCING FEATURE MAY KEEP COVERAGE IN THE LOW END SCATTERED RANGE. BETTER SHOT FOR SHOWERS AND STORMS COMES INTO THE FORECAST SUNDAY AND SUNDAY NIGHT...AS SOUTHERN STREAM UPPER LEVEL SHORTWAVE ACROSS BAJA CALIFORNIA EJECTS EAST ACROSS TEXAS. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 85 68 83 68 84 / - - 10 20 40 AUSTIN BERGSTROM INTL AIRPORT 84 68 84 68 82 / - - 10 20 30 NEW BRAUNFELS MUNI AIRPORT 85 68 86 67 85 / - - 10 20 20 BURNET MUNI AIRPORT 84 67 82 66 84 / - - 10 20 40 DEL RIO INTL AIRPORT 84 68 86 67 89 / - 10 20 20 - GEORGETOWN MUNI AIRPORT 84 68 83 67 83 / - - 10 20 40 HONDO MUNI AIRPORT 85 68 86 67 86 / - - 10 20 20 SAN MARCOS MUNI AIRPORT 84 69 82 68 84 / - - 10 20 30 LA GRANGE - FAYETTE REGIONAL 84 70 84 70 83 / - - 10 10 30 SAN ANTONIO INTL AIRPORT 85 69 86 69 85 / - - 10 20 20 STINSON MUNI AIRPORT 85 69 87 68 85 / - - 10 10 20 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...26 SYNOPTIC/GRIDS...04
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1145 PM CDT TUE APR 7 2015 .DISCUSSION... SEE THE 06Z AVIATION DISCUSSION BELOW. 40 && .AVIATION... 11-3.9 MICRON IR WAS SHOWING LOW CLOUDS SPREADING INLAND FROM THE COAST. THE LATEST HIGH RESOLUTION MODELS FORECAST AT LEAST MVFR CONDITIONS THROUGH ABOUT 15Z. WHILE THERE IS A CHANCE FOR IFR... DECIDED TO GO WITH PREVAILING MVFR FOR NOW. VFR AND BREEZY CONDITIONS WILL DEVELOP DURING THE LATE MORNING. 40 && .PREV DISCUSSION... /ISSUED 841 PM CDT TUE APR 7 2015/ UPDATE... SEE EVENING UPDATE. DISCUSSION... 00Z SOUNDINGS SHOW A CAPPING LAYER BETWEEN 850-700 MB AND RELATIVELY MEAGER PW VALUES. 850 MB MSTR IS CONFINED TO NE TX TO SE LA. 700MB LOOKS VERY DRY WITH VERY WARM 700 MB TEMPS EXTENDING FROM LCH TO BRO. TWEAKED SKY GRIDS AS LOW LEVEL CLOUDS EXPANDING QUICKLY OVER THE COASTAL COUNTIES. LEANED TOWARD THE HRRR FOR CLOUD COVER TONIGHT AND FEEL SKIES WILL BECOME MOSTLY CLOUDY PRIOR TO SUNRISE. MIN TEMPS LOOK ON TRACK SO NO CHANGES PLANNED THERE. PATCHY FOG STILL BEING REPORTED OVER THE WESTERN GULF SO WILL KEEP WX GRIDS AS IS. LOOKING AHEAD...CURRENT FCST SEEMS TO HAVE A GOOD HANDLE ON TWO WEATHER EVENTS FOR LATER THIS WEEK AND OVER THE WEEKEND. LOOKS LIKE HIGH RAIN CHANCES FRI-SUN WITH SUNDAY LOOKING INTERESTING FOR BOTH HEAVY RAIN AND POSSIBLY STRONG STORMS. THE HIGH AT BUSH IAH TODAY WAS 87 DEGREES. IT IS THE WARMEST TEMPERATURE SO FAR THIS YEAR. THE LAST TIME HOUSTON REACHED 87 DEGREES WAS ON OCT 16 2014. 43 PREV DISCUSSION... /ISSUED 627 PM CDT TUE APR 7 2015/ DISCUSSION... SEE THE 00Z AVIATION DISCUSSION BELOW. 40 AVIATION... THE MODEL FORECAST SOUNDINGS CONTINUE THE THEME OF THE 12Z RAOB SOUNDINGS AND KEEP A LOW-LEVEL CAPPING INVERSION IN PLACE TONIGHT INTO WEDNESDAY. EXPECTING MVFR CEILINGS TO DEVELOP BY AROUND 06Z AND PERSIST THROUGH POSSIBLY AS LATE AS 16Z. SOME LOCATIONS MAY EXPERIENCE BRIEF IFR CONDITIONS...ALTHOUGH THESE LOOK TO BECOME MORE PREVALENT AT KLBX AND KGLS. EXPECTING VFR AND BREEZY CONDITIONS TO DEVELOP DURING THE LATE MORNING WEDNESDAY. 40 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 69 84 70 83 68 / 10 10 20 50 40 HOUSTON (IAH) 69 83 71 83 70 / 10 10 10 30 30 GALVESTON (GLS) 70 79 71 80 71 / 10 10 10 20 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...43 AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS PORTLAND
850 PM PDT THU APR 9 2015 .SYNOPSIS...A WEAK UPPER RIDGE WILL BRING DRY WEATHER TO SOUTHWEST WASHINGTON AND NORTHWEST OREGON TONIGHT AND MOST OF FRIDAY. THE NEXT DECENT PACIFIC COLD FRONT WILL SPREAD SOME RAIN ONTO MAINLY THE SOUTH WASHINGTON AND FAR NORTH OREGON COASTAL AREAS FRIDAY AFTERNOON...THEN MOVE THROUGH SOUTHWEST WASHINGTON AND NORTHWEST OREGON FRIDAY NIGHT WITH DECENT RAINS AND SOME MOUNTAIN SNOW. A COOL SHOWERY ONSHORE FLOW PATTERN WILL FOLLOW ON SATURDAY BEHIND THE FRONT WITH MOST OF THE AREA LOOKING DRY ON SUNDAY AND EARLY MONDAY. ANOTHER COOL AND WET STORM SYSTEM LOOKS TO ARRIVE LATER MONDAY AND MONDAY NIGHT FOR MORE VALLEY RAIN AND MOUNTAIN SNOW BEFORE HIGH PRESSURE BRINGS DRIER AND WARMER WEATHER BEGINNING THE MIDDLE OF NEXT WEEK. && .SHORT TERM...TONIGHT THROUGH SUNDAY...CLOUDS HAVE MOSTLY CLEARED THIS EVENING ACROSS SOUTHWEST WASHINGTON AND NORTHWEST OREGON WITH ANY CASCADE SHOWERS LONG GONE. SKIES SHOULD REMAIN MOSTLY CLEAR OVERNIGHT UNDER A WEAK UPPER RIDGE...THOUGH SOME PATCHY RADIATIONAL FOG OR LOW CLOUDS ARE POSSIBLE LATE TONIGHT AND FRIDAY MORNING. DEWPOINTS AND THUS THE FOG CROSSOVER TEMP HAVE FALLEN AS COMPARED TO 24 HOURS AGO DUE TO THE WARMER DAY TODAY...SO EXPECT ANY FOG WILL BE PATCHIER TONIGHT THAN THIS MORNING. ATTENTION THEN TURNS TO THE NEXT PACIFIC COLD FRONT...WHICH IS FORECAST TO SPREAD SOME PRECIPITATION ONTO THE SOUTH WASHINGTON AND NORTH OREGON COASTAL AREAS FRIDAY AFTERNOON...THEN MOVE THROUGH THE REST OF SOUTHWEST WASHINGTON AND NORTHWEST OREGON FRIDAY NIGHT. THE FRONT SHOULD MOSTLY BE EAST OF THE CASCADES BY SUNRISE SATURDAY. THIS FRONT WILL HAVE SOME BREEZY CONDITIONS ALONG THE COAST WHERE WINDS OVER THE WATERS COULD GET CLOSE TO GALE FORCE. THE FRONT WILL HAVE A DECENT DOSE OF RAIN AS IT MOVES THROUGH. SNOW LEVELS IN THE CASCADES WILL START OFF WELL ABOVE THE PASSES LATE FRIDAY AND FRIDAY EVENING...THEN FALL BELOW PASS ELEVATIONS AFTER MIDNIGHT FRIDAY NIGHT AND ON SATURDAY. SNOW LEVELS WILL BOTTOM OUT BETWEEN 3000 AND 4000 FEET ESPECIALLY IN THE SOUTH WASHINGTON AND NORTH OREGON CASCADES...WHILE THE LANE COUNTY CASCADES WILL BOTTOM OUT BETWEEN 4000 AND 5000 FEET. AMOUNTS COULD REACH CLOSE TO 6 INCHES ESPECIALLY AT THE SKI RESORTS LATER FRIDAY NIGHT INTO SATURDAY...ESPECIALLY NORTH OF ABOUT SANTIAM PASS. THE COOL POST FRONTAL ONSHORE FLOW WILL KEEP DECENT SHOWER ACTIVITY GOING THROUGH MOST OF SATURDAY. UPPER RIDGING WILL MOVE IN SATURDAY NIGHT AND SUNDAY THAT WILL BRING MOSTLY DRY WEATHER TO MOST OF THE AREA BY SUNDAY. TOLLESON .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS... SUNDAY NIGHT THROUGH WEDNESDAY...MODELS CONTINUE TO SHOW AN UPPER LEVEL TROUGH APPROACHING THE PACIFIC NORTHWEST EARLY NEXT WEEK. THE FRONT LOOKS TO PUSH ONSHORE LATE MONDAY/EARLY TUESDAY. HOWEVER...DUE TO TIMING DIFFERENCES BETWEEN YESTERDAYS AND TODAYS RUNS DECIDED TO KEEP SLIGHT CHANCE POPS FOR SUNDAY NIGHT OVER PORTIONS OF THE CWA. SNOW LEVELS WILL REMAIN AROUND 3000 FT THROUGH EARLY WEDNESDAY. WITH DECENT MOISTURE...MODEST PRE AND POST FRONTAL INSTABILITY...AND STRONG MID AND UPPER LEVEL ONSHORE FLOW THE CASCADES AND FOOTHILLS COULD SEE ADVISORY LEVEL SNOW TOTALS. STILL NOT EXPECTING THUNDERSTORMS AT THE MOMENT...BUT WILL NEED TO REEVALUATE IN THE COMING DAYS. STRONG UPPER LEVEL RIDGING LOOKS TO RETURN ON WEDNESDAY AND COULD STICK AROUND THROUGH THE END OF THE WORKWEEK. EXPECT DRIER AND WARMER WEATHER...WITH HIGHS APPROACHING 70 DEGREES THURSDAY AFTERNOON ACROSS PORTIONS OF THE CWA. /64 && .AVIATION...VFR THIS EVENING UNDER HIGH PRESSURE. WITH RECENT RAIN AND CALM WINDS...SHOULD STILL SEE A BRIEF PERIOD OF MVFR/IFR LOW STRATUS OR FOG BETWEEN 08-12Z FRI. INCREASING WINDS OUT OF THE SOUTH SHOULD CLEAR OUT FOG BY 15Z IMPROVING CONDITIONS TO VFR. MODERATE CONFIDENCE THAT FOG WILL IMPACT PROTECTED INLAND SITES...AND HIGHER CONFIDENCE THAT FOG WILL DEVELOP ALONG THE COAST...REDUCING CIGS AND VIS TO IFR/LIFR. VFR CONDITIONS TO CONTINUE AFTER 16Z THROUGH MIDDAY SATURDAY...WITH INCREASING RAIN BY 21Z AT THE COAST AND BY 00Z SAT INLAND. KPDX AND APPROACHES...VFR CONDITIONS TO CONTINUE THIS EVENING. THERE MAY BE A PERIOD AFTER 08Z WHERE FOG COULD DEVELOP...BUT INCREASING SOUTHERLY WINDS FRI MORNING SHOULD CLEAR OUT ANY FOG THAT DEVELOPS BY 16Z. RAIN ARRIVES BETWEEN 00Z-03Z SAT. -MCCOY/27 && .MARINE...PACIFIC FRONT FORECAST TO MOVE THROUGH THE WATERS FRI AFTERNOON/EVENING. WINDS RAMP UP TO 20 TO 30 KTS AHEAD OF THE FRONT...WITH A FEW GUSTS TO 35 KTS LIKELY JUST AHEAD OF THE FRONT. MODELS ARE STILL KEEPING BOUNDARY LAYER WINDS HOVERING RIGHT AROUND 35 KTS FRI AFTERNOON AND EVENING...DECIDED TO HOLD OFF ON ISSUING A GALE WATCH AT THIS POINT. WOULD LIKE ANOTHER MODEL RUN GIVEN SUCH BORDERLINE WINDS. BEHIND THE FRONT...WINDS DECREASE A BIT TO 15 TO 20 KTS WITH GUSTS TO 25 KTS THROUGH SAT MORNING. WINDS GRADUALLY DECREASE THROUGH THE DAY SAT. AS WINDS RAMP UP...SEAS BUILD TO 10 TO 12 FT FRI EVENING...PEAKING FRI EVENING WITH FRONTAL PASSAGE. 8 TO 9 FT SWELL WILL KEEP SEAS UP AROUND 8 TO 10 FT THROUGH SAT. ANOTHER FRONT FORECAST TO MOVE THROUGH THE WATERS LATE SUN/EARLY MON...BRINGING ANOTHER ROUND OF SMALL CRAFT WINDS AND BUILDING SEAS BACK UP INTO THE LOW-TO-MIDDLE TEENS. -MCCOY/27 && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 11 AM FRIDAY TO 11 AM PDT SATURDAY FOR COASTAL WATERS FROM CAPE SHOALWATER TO FLORENCE OUT 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 11 AM FRIDAY TO 11 AM PDT SATURDAY FOR WATERS FROM CAPE SHOALWATER TO FLORENCE FROM 10 TO 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 2 PM FRIDAY TO 11 AM PDT SATURDAY FOR COASTAL WATERS FROM CAPE SHOALWATER TO FLORENCE OUT 10 NM. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
  [top] Area Forecast Discussion National Weather Service Spokane WA 451 PM PDT THU APR 9 2015 .SYNOPSIS... A few showers will linger into the evening then a drier and mild southerly flow returns Friday, pushing temperatures above normal. A strong cold front passes through Friday night bringing the next round of showers and breezy winds. Saturday remains windy and unsettled, with cooler temperatures. Another strong cold front is expected by Tuesday...with dry weather returning Wednesday and next Thursday. && .DISCUSSION... Tonight through Friday night: An active spring weather pattern will persist for the Northwestern US but we will see a break and period of mild and dry weather in between storm systems. First off, a weakening low pressure system currently lifting northward through southern WA will keep enough instability over the area to promote isolated mountain showers through the early evening. Showers will be a bit more organized at the base of the trof or generally over SE WA and the ID Panhandle. Afternoon satellite and radar support this idea and HRRR for several runs suggest this cluster will slowly lift north near the WA/ID border late this afternoon and evening before decaying prior to midnight. There has been some wavering how far east or west to bring these clusters of showers with the possibility ranging from Wilbur to ID/MT border but given the run to run continuity...PoPs have been increased. Our lowest confidence is related the thunder potential. Model instability parameters support an isolated threat but excess cloud cover within these regions may keep temperatures down some and cut into the potential afternoon CAPE. Overall, the impacts from this activity will be low. This wave will lift out the region by early Saturday and shortwave ridging will briefly return Friday ahead of the next storm system. Look for increase in southerly winds through the day coupled with afternoon temperatures in the mid to upper 60s. There is a small chance for an isolated shower or thunderstorm developing around NE OR to the Blue Mtns but confidence is low. If any storms develop, they will track quickly to the northeast and may brush the Camas Prairie, L-C Valley, and Central Panhandle Mtns. A strong cold front will press through the Inland NW Friday night into early Saturday morning. The front will bring increasing clouds, chance for showers, and increase in west to southwest winds. The Basin will receive very light precipitation from this event with little to no QPF in the immediate lee of the Cascades. Up to 0.20" will be possible in the Idaho Panhandle and closer to a half an inch along the Cascade Crest. There will be a good deal of cooler air behind the front which will allow snow levels to drop below pass levels in the Cascades early Saturday morning and periods of snow will be possible just prior to sunrise. /sb Saturday through Monday morning...A fast moving cold front will track through the Inland northwest early Saturday morning. This will result in a chance of rain and mountain snow showers, cooler temperatures, and gusty winds. Saturday night and Sunday weak high pressure will build back into the region for weaker winds and stable conditions. On Saturday the cold front will cross the Cascades right around 12z and push rapidly through the forecast area through the morning. Southwest flow ahead of the front will tap into slightly deeper Pacific moisture. Precipitation should come as showers with the frontal passage. Behind the front the atmosphere will destabilize enough for showers through the afternoon and early evening for just about all locations, with the best chance near the Cascade crest and the Panhandle mountains. Model guidance shows there is a low end chance for a lightning strike or two across the northeast mountains, but confidence is not real high, so will leave the mention of thunder out of the forecast for now. The southwest-west flow will likely result in little to no precipitation for the lower east slopes and deep basin, With amounts ranging from .10 to .30 for the Cascade crest and Panhandle mountains. In between the basin and the mountains local amounts up to .10 of an inch will be possible. Snow levels drop to between 2500-3500 feet for snow in the mountains and rain in the lower elevations. Some of the higher elevation could pick up 3-6 inches of fresh snow. The Puget Sound Convergence Zone is expected to develop across the Cascades in the vicinity of Stevens Pass and Snoqualmie Pass. If the convergence zone does set up this could result in several hours of moderate to heavy snow near the crest. Moderate to cold air advection behind the cold front will result in temperatures dropping 10-14 degrees on Saturday with highs on the cool side of normal. A spring air mass change with moderate to strong cold air advection, a tightening surface gradient and 25-30kt 850mb winds sets up the perfect pattern for a windy/gusty event beginning Saturday morning and lasting until after sunset Saturday evening. Southwest-west winds 15-25 mph with gusts 30-35mph will be common across the area. People doing outside activities should be prepared for a raw, blustery day. Saturday night through Monday morning high pressure will build into the region. Temperatures will likely not be able to rebound by more than a degree or two on Sunday. Southwest-west surface to mid level flow and lingering low level moisture will keep a chance for rain and snow showers in the forecast for the usual up-sloping areas like the Cascade Crest, the northeast Washington mountains, and the Idaho Panhandle mountains. Locations that do get precipitation will be rather light with amounts under a tenth of an inch. Winds will remain slightly elevated but mainly in the 10-15 mph category. Tobin Monday through Thursday...Forecast models have continued the slower trend of a cold front passage...which is expected Monday night. Southwest flow ahead of the front will probably allow a tongue of warmer air to move into Eastern Washington and North Idaho with 850mb temps warming to 5-12C. The GFS/GEM solutions are the warmest while the ECMWF is a bit faster with the cold front...reaching Central Washington in the late afternoon. This in turn leads to lower confidence with precise values of high temps on Monday especially Central and Eastern Washington with a bit higher confidence of significant warming for North Idaho. As the cold front moves in Monday night models show it to be a fast mover with mid level westerly flow leading to the orographically favored areas of the Cascade crest and Idaho Panhandle likely seeing some precipitation. Central Washington will likely be rain shadowed with little to no precipitation, with generally a tenth of an inch or less for Eastern Washington. Snow levels with the cold front will be around 4000-5000 feet and then will lower to 2000-3000 feet behind the front on Tuesday. Light to moderate snow accumulations will be possible in the mountains Monday night and Tuesday morning. With the upper trough overhead on Tuesday with 500mb temps around -34C convective shower activity will pop up with mid level westerly flow keeping activity isolated in the basin with the most numerous activity over the mountains of northern Washington and the Idaho Panhandle. A few thunderstorms will also be possible mainly over the Idaho Panhandle and possibly extreme Eastern Washington. Drier air mixing down in Central and Eastern Washington will result in higher LCL levels (and thus colder LCL temps), making it more difficult for charge separation with model soundings showing LCL temps near -10C in the basin. On Wednesday and Thursday the trough moves out and is replaced by an upper ridge. The amplitude of the ridge is in question...but models agree that it will be enough for dry conditions...except for a chance for a few lingering showers over North Idaho mountains on Wednesday. With a cooler air mass initially in place on the back side of the departing trough...and clearing skies most areas are expected to drop to at or below freezing Tuesday and Wednesday night. JW && .AVIATION... 00Z TAFS: A negatively tilted upper level trough of lower pressure will push across the region this evening. Convective showers will continue through this evening and then dissipate tonight as surface heating is lost with sunset. Some of the stronger showers will be capable of producing brief lightning and heavy downpours. More organized thunderstorm activity has been observed over the Northeast Blue Mtns and Camas Prairie, but have shown considerable weakening as they move northeast off of the higher terrain. Still, there is a small chance that this convection holds on long enough to impact the KLWS and KPUW TAF sites. Confidence is too low to include thunderstorms at any other TAF sites. /SVH && .PRELIMINARY POINT TEMPS/POPS... Spokane 37 64 41 51 32 51 / 30 10 40 40 20 10 Coeur d`Alene 37 63 39 50 31 50 / 30 10 60 60 30 20 Pullman 37 64 43 50 33 52 / 20 10 60 70 20 10 Lewiston 37 69 47 56 36 58 / 20 10 50 40 10 10 Colville 36 67 42 55 31 53 / 20 10 40 60 20 10 Sandpoint 37 62 38 50 30 50 / 20 10 70 80 40 20 Kellogg 35 62 38 44 30 47 / 30 10 70 100 40 30 Moses Lake 38 69 43 58 34 58 / 0 0 10 10 10 10 Wenatchee 40 67 44 56 38 58 / 10 0 10 30 10 10 Omak 36 66 39 57 30 57 / 10 10 10 10 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML

Area Forecast Discussion National Weather Service Spokane WA 226 PM PDT THU APR 9 2015 .SYNOPSIS... A few showers will linger into the evening then a drier and mild southerly flow returns Friday, pushing temperatures above normal. A strong cold front passes through Friday night bringing the next round of showers and breezy winds. Saturday remains windy and unsettled, with cooler temperatures. Another strong cold front is expected by Tuesday...with dry weather returning Wednesday and next Thursday. && .DISCUSSION... Tonight through Friday night: An active spring weather pattern will persist for the Northwestern US but we will see a break and period of mild and dry weather in between storm systems. First off, a weakening low pressure system currently lifting northward through southern WA will keep enough instability over the area to promote isolated mountain showers through the early evening. Showers will be a bit more organized at the base of the trof or generally over SE WA and the ID Panhandle. Afternoon satellite and radar support this idea and HRRR for several runs suggest this cluster will slowly lift north near the WA/ID border late this afternoon and evening before decaying prior to midnight. There has been some wavering how far east or west to bring these clusters of showers with the possibility ranging from Wilbur to ID/MT border but given the run to run continuity...PoPs have been increased. Our lowest confidence is related the thunder potential. Model instability parameters support an isolated threat but excess cloud cover within these regions may keep temperatures down some and cut into the potential afternoon CAPE. Overall, the impacts from this activity will be low. This wave will lift out the region by early Saturday and shortwave ridging will briefly return Friday ahead of the next storm system. Look for increase in southerly winds through the day coupled with afternoon temperatures in the mid to upper 60s. There is a small chance for an isolated shower or thunderstorm developing around NE OR to the Blue Mtns but confidence is low. If any storms develop, they will track quickly to the northeast and may brush the Camas Prairie, L-C Valley, and Central Panhandle Mtns. A strong cold front will press through the Inland NW Friday night into early Saturday morning. The front will bring increasing clouds, chance for showers, and increase in west to southwest winds. The Basin will receive very light precipitation from this event with little to no QPF in the immediate lee of the Cascades. Up to 0.20" will be possible in the Idaho Panhandle and closer to a half an inch along the Cascade Crest. There will be a good deal of cooler air behind the front which will allow snow levels to drop below pass levels in the Cascades early Saturday morning and periods of snow will be possible just prior to sunrise. /sb Saturday through Monday morning...A fast moving cold front will track through the Inland northwest early Saturday morning. This will result in a chance of rain and mountain snow showers, cooler temperatures, and gusty winds. Saturday night and Sunday weak high pressure will build back into the region for weaker winds and stable conditions. On Saturday the cold front will cross the Cascades right around 12z and push rapidly through the forecast area through the morning. Southwest flow ahead of the front will tap into slightly deeper Pacific moisture. Precipitation should come as showers with the frontal passage. Behind the front the atmosphere will destabilize enough for showers through the afternoon and early evening for just about all locations, with the best chance near the Cascade crest and the Panhandle mountains. Model guidance shows there is a low end chance for a lightning strike or two across the northeast mountains, but confidence is not real high, so will leave the mention of thunder out of the forecast for now. The southwest-west flow will likely result in little to no precipitation for the lower east slopes and deep basin, With amounts ranging from .10 to .30 for the Cascade crest and Panhandle mountains. In between the basin and the mountains local amounts up to .10 of an inch will be possible. Snow levels drop to between 2500-3500 feet for snow in the mountains and rain in the lower elevations. Some of the higher elevation could pick up 3-6 inches of fresh snow. The Puget Sound Convergence Zone is expected to develop across the Cascades in the vicinity of Stevens Pass and Snoqualmie Pass. If the convergence zone does set up this could result in several hours of moderate to heavy snow near the crest. Moderate to cold air advection behind the cold front will result in temperatures dropping 10-14 degrees on Saturday with highs on the cool side of normal. A spring air mass change with moderate to strong cold air advection, a tightening surface gradient and 25-30kt 850mb winds sets up the perfect pattern for a windy/gusty event beginning Saturday morning and lasting until after sunset Saturday evening. Southwest-west winds 15-25 mph with gusts 30-35mph will be common across the area. People doing outside activities should be prepared for a raw, blustery day. Saturday night through Monday morning high pressure will build into the region. Temperatures will likely not be able to rebound by more than a degree or two on Sunday. Southwest-west surface to mid level flow and lingering low level moisture will keep a chance for rain and snow showers in the forecast for the usual up-sloping areas like the Cascade Crest, the northeast Washington mountains, and the Idaho Panhandle mountains. Locations that do get precipitation will be rather light with amounts under a tenth of an inch. Winds will remain slightly elevated but mainly in the 10-15 mph category. Tobin Monday through Thursday...Forecast models have continued the slower trend of a cold front passage...which is expected Monday night. Southwest flow ahead of the front will probably allow a tongue of warmer air to move into Eastern Washington and North Idaho with 850mb temps warming to 5-12C. The GFS/GEM solutions are the warmest while the ECMWF is a bit faster with the cold front...reaching Central Washington in the late afternoon. This in turn leads to lower confidence with precise values of high temps on Monday especially Central and Eastern Washington with a bit higher confidence of significant warming for North Idaho. As the cold front moves in Monday night models show it to be a fast mover with mid level westerly flow leading to the orographically favored areas of the Cascade crest and Idaho Panhandle likely seeing some precipitation. Central Washington will likely be rain shadowed with little to no precipitation, with generally a tenth of an inch or less for Eastern Washington. Snow levels with the cold front will be around 4000-5000 feet and then will lower to 2000-3000 feet behind the front on Tuesday. Light to moderate snow accumulations will be possible in the mountains Monday night and Tuesday morning. With the upper trough overhead on Tuesday with 500mb temps around -34C convective shower activity will pop up with mid level westerly flow keeping activity isolated in the basin with the most numerous activity over the mountains of northern Washington and the Idaho Panhandle. A few thunderstorms will also be possible mainly over the Idaho Panhandle and possibly extreme Eastern Washington. Drier air mixing down in Central and Eastern Washington will result in higher LCL levels (and thus colder LCL temps), making it more difficult for charge separation with model soundings showing LCL temps near -10C in the basin. On Wednesday and Thursday the trough moves out and is replaced by an upper ridge. The amplitude of the ridge is in question...but models agree that it will be enough for dry conditions...except for a chance for a few lingering showers over North Idaho mountains on Wednesday. With a cooler air mass initially in place on the back side of the departing trough...and clearing skies most areas are expected to drop to at or below freezing Tuesday and Wednesday night. JW && .AVIATION... 18Z TAFS: An upper low drifts from the WA/OR border toward the northern Rockies. This feature and afternoon instability will bring increasing clouds and a threat of isolated to scattered showers this afternoon, particularly closer to the ID/WA border eastward and to a lesser extent near the Cascades. A more organized cluster of showers will drift from KPUW-KLWS to KGEG- KCOE btwn 22-03z. There is a threat for thunder but confidence is too low to include in TAF. Any storms will bring the potential for brief downpours of rain and small hail. /sb && .PRELIMINARY POINT TEMPS/POPS... Spokane 37 64 41 51 32 51 / 30 10 40 40 20 10 Coeur d`Alene 37 63 39 50 31 50 / 30 10 60 60 30 20 Pullman 37 64 43 50 33 52 / 20 10 60 70 20 10 Lewiston 37 69 47 56 36 58 / 20 10 50 40 10 10 Colville 36 67 42 55 31 53 / 20 10 40 60 20 10 Sandpoint 37 62 38 50 30 50 / 20 10 70 80 40 20 Kellogg 35 62 38 44 30 47 / 30 10 70 100 40 30 Moses Lake 38 69 43 58 34 58 / 0 0 10 10 10 10 Wenatchee 40 67 44 56 38 58 / 10 0 10 30 10 10 Omak 36 66 39 57 30 57 / 10 10 10 10 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1105 PM CDT THU APR 9 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 350 PM CDT THU APR 9 2015 TWO AREAS OF CONCERN TONIGHT FOR PRECIPITATION. THE FIRST WILL BE EARLY THIS EVENING ACROSS THE FAR SOUTH AS THE SURFACE LOW PASSES BY THE REGION. THE LATEST INDICATIONS CONTINUE TO POINT TO THE SURFACE LOW TRACKING JUST SOUTH OF THE AREA AS IT COMES OUT OF EASTERN IOWA INTO SOUTH CENTRAL WISCONSIN. ON THIS PATH...THE WARM SECTOR AND THE BEST SUPPORT FOR SEVERE WEATHER WILL REMAIN OUTSIDE OF THE FORECAST AREA. LOOKING AT THE TRENDS IN THE 09.19Z RAP AND HRRR...THE CONVECTION THAT DEVELOPS AHEAD OF THE SURFACE LOW LATE THIS AFTERNOON COULD POSSIBLY CLIP GRANT COUNTY BUT SHOULD BE TO THE EAST OF THE AREA BY 00Z. BASED ON THIS SCENARIO...WILL ONLY SHOW ABOUT A 50 PERCENT CHANCE FOR SHOWERS AND STORMS ACROSS THE FAR SOUTHERN SECTIONS FOR EARLY THIS EVENING. THE OTHER AREA OF CONCERN WILL BE IN THE DEFORMATION AREA ON THE BACK SIDE OF THE SURFACE LOW. THIS AREA LOOKS TO HAVE SOME PRETTY GOOD FORCING IN IT THIS EVENING AS THE SHORT WAVE TROUGH...CURRENTLY OVER THE MISSOURI RIVER VALLEY...CONTINUES TO MOVE NORTHEAST AND TAKES ON A NEGATIVE TILT. THIS WILL ALLOW FOR A QUICK SHOT OF STRONG PV ADVECTION TO OCCUR IN THE 500-300 MB LAYER. THERE IS A GOOD LOW LEVEL BAROCLINIC ZONE IN PLACE WITH TEMPERATURES IN THE 30S AND 40S ON THE COOL SIDE OF THE LOW AND IN THE 60S AND 70S IN THE WARM SECTOR. BOTH THE 09.12Z NAM AND GFS SHOW MODERATE TO STRONG FRONTOGENESIS OCCURRING IN THE DEFORMATION ZONE WITH THIS BEING THE STRONGEST IN THE 750-650 MB LAYER. THIS FRONTOGENESIS LOOKS TO SIT UNDERNEATH AN AREA OF STRONG UPPER LEVEL DIVERGENCE FROM A COUPLED UPPER LEVEL JET STRUCTURE. THE NAM SUGGESTS THIS SYSTEM SHOULD GET STRONG ENOUGH TO WRAP THE WARM CONVEYOR BELT AROUND THE LOW TO PRODUCE 4-6 UBAR/S OF ISENTROPIC UP GLIDE ON THE 295K SURFACE THIS EVENING IN THE SAME GENERAL AREA AS THE FRONTOGENESIS. LOOKS LIKE THE DEFORMATION PRECIPITATION IS ALREADY STARTING TO FORM ACROSS SOUTHEAST MINNESOTA AND EXPECT THIS WILL CONTINUE TO GROW AS THE FORCING INCREASES THIS EVENING. WHEN THE STRONGEST FORCING OCCURS...THIS SHOULD BE ENOUGH TO PRODUCE SOME HIGH PRECIPITATION RATES TO ALLOW FOR A CHANGE OVER TO ALL SNOW DESPITE SOME WARM LOW LEVEL BOUNDARY TEMPERATURES. THE BEST CHANCES FOR THIS TO OCCUR THIS EVENING WILL BE FROM SOUTHEAST MINNESOTA INTO NORTH CENTRAL WISCONSIN. THE DURATION OF THIS SHOULD NOT BE VERY LONG OVER SOUTHEAST MINNESOTA...BUT THE SNOW COULD PERSIST INTO THE OVERNIGHT HOURS FOR NORTH CENTRAL MINNESOTA. THIS COULD LEAD TO ACCUMULATIONS OF 2 TO 3 INCHES ACROSS TAYLOR COUNTY AND WILL ISSUE A WINTER WEATHER ADVISORY TO HANDLE THIS. A SECONDARY SHORT WAVE TROUGH WILL DROP ACROSS THE AREA THURSDAY. IT LOOKS LIKE A LOT OF THE DEEP MOISTURE WILL GET SCOURED OUT BEHIND THE MAIN SHORT WAVE TROUGH BUT STILL EXPECT THAT THIS WAVE WILL BE STRONG ENOUGH TO PRODUCE SOME LIGHT PRECIPITATION FOR AREAS ALONG AND EAST OF THE MISSISSIPPI RIVER FROM LATE MORNING THROUGH THE AFTERNOON. HIGH PRESSURE THEN LOOKS TO BUILD IN BEHIND THIS SYSTEM AND DRIFT ACROSS THE REGION TO KEEP THE FRIDAY NIGHT THROUGH SATURDAY NIGHT PERIOD DRY. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 350 PM CDT THU APR 9 2015 THE MODELS ARE ALL IN GOOD AGREEMENT OF ANOTHER SHORT WAVE TROUGH COMING ACROSS THE UPPER MIDWEST FOR SUNDAY AND SUNDAY NIGHT. THIS IS EXPECTED TO PUSH A COLD FRONT ACROSS THE REGION WHICH SHOULD BE ACCOMPANIED BY A LINE OF SHOWERS AND STORMS. SOME DIFFERENCES BETWEEN THE 09.12Z GFS AND ECMWF ON HOW FAST THIS ACTIVITY MOVES IN SUNDAY WITH THE GFS QUICKER TO BRING IT IN THAN THE ECMWF. WILL ATTEMPT TO RESOLVE THESE DIFFERENCES WITH LATER FORECASTS ONCE THE SHORT TERM WEATHER QUIETS DOWN. THE MODELS ALSO ARE IN GOOD AGREEMENT FOR LATER IN THE PERIOD BRINGING ANOTHER SYSTEM INTO THE CENTRAL PART OF THE COUNTRY FOR LATE IN THE PERIOD. WITH THE SOUTHWEST FLOW AHEAD OF THIS SYSTEM...COULD SEE SOME ACTIVITY FORM AS EARLY AS TUESDAY NIGHT AND THEN CONTINUE OFF AND ON THROUGH THURSDAY. HAVE LET THE MODEL CONSENSUS GRIDS RIDE WITH THIS SYSTEM WITH GENERAL 30 TO 40 PERCENT CHANCES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1105 PM CDT THU APR 9 2015 CIGS: GOING TO BE QUICK IMPROVEMENT AS THE PCPN AREA MOVES EAST. SATELLITE IMAGERY AND SFC OBS POINT TO THE CIGS GIVING WAY TO SCT SKIES ABOUT AN HOUR AFTER THE PCPN ENDS. SHOULD HAVE CLEARED AT KRST BY NEXT TAF ISSUANCE...AND BY 07-08Z FOR KLSE. AN UPPER LEVEL SHORTWAVE TROUGH TRACKS ACROSS THE AREA LATE FRI MORNING-AFTERNOON. MVFR CIGS LOOK LIKELY WITH THIS...BUT SHOULD CLEAR AGAIN AROUND 00Z. WINDS: WINDS SHOULD SLACKEN A BIT OVERNIGHT...BUT WINDS WILL STAY +10 KTS THROUGH THE DAY FRI. HIGH PRESSURE BUILDS IN FRIDAY NIGHT...WITH WINDS BECOMING LIGHT FROM THE SOUTH SOUTHWEST. WX/VSBY: DEFORMATION REGION OF A STORM SYSTEM IS CLEARING KRST...AND SHOULD PASS KLSE BY 07Z. SOME VSBY REDUCTIONS IN THE RASN...BUT IMPROVES AFTER IT ENDS. ANOTHER ROUND OF SCATTERED -SHRA IS LIKELY FROM LATE MORNING INTO THE AFTERNOON FRIDAY AS A SHORTWAVE PASSES ACROSS THE AREA. COULD HAVE SOME DIP INTO MVFR VSBYS WITH THE SHOWERS...BUT MOSTLY P6SM. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 7 AM CDT FRIDAY FOR WIZ017. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...RIECK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
935 PM CDT THU APR 9 2015 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE AND NEW INFORMATION ADDED TO UPDATE SECTION .UPDATE... ISSUED AT 929 PM CDT THU APR 9 2015 HAVE DECIDED TO UPGRADE MY NW/NRN 4 COUNTIES TO A WINTER STORM WARNING. NOT A CLEAR-CUT SITN AT ALL...BUT GIVEN THE STRENGTH OF THE DYNAMICS TO COME ACRS THAT AREA LATER IN THE NGT...COULD EASILY SEE SOME 1-2 INCH PER HOUR SNOWFALL RATES. WL CALL FOR 4-8 INCH TOTALS IN THE WSW. THINK THE HIGHEST TOTALS WILL END UP IN AN AREA NE OF A LINE FROM BOULDER JUNCTION...TO RHINELANDER...TO CRANDON...TO FLORENCE. ELSEWHERE ACRS THE AREA...INITIAL SURGE OF PCPN HAS SHIFTED THROUGH...BUT EXPECT SOME REDEVELOPMENT AHEAD OF THE MAIN SHRTWV. WL KEEP HIGH POPS GOING MOST OF THE NGT. UPDATED PRODUCT SUITE WL BE OUT ASAP. UPDATE ISSUED AT 536 PM CDT THU APR 9 2015 FCST ISSUES SPAN THE SEASONS THIS EVENING AS STRENGTHENING CYCLONE LIFTS NEWD FM IA. CLUSTER OF SVR STORMS IN S-C WI HEADING NE. LOCAL MESO PLOTS SHOW POOL OF INSTABILITY EXPANDING NE...BUT NOT AS QUICKLY AS THE STORMS ARE MOVG NE. IT/S GOING TO BE A CLOSE CALL ON WHETHER A SVR STORM COULD CLIP THE SRN PART OF THE FCST AREA BEFORE WEAKENING. THE PRIMARY SVR THREAT WOULD BE HAIL...AND THINK THAT WOULD NEED TO HAPPEN WITHIN THE NEXT COUPLE HRS...BEFORE PCPN GETS TOO WIDESPREAD. IT/S A COMPLETELY DIFFERENT SITN ACRS THE NW CORNER OF THE FCST AREA...WHERE THE THREAT IS HEAVY SNOW. WATCHING THE UPR DEFORMATION ZONE EXPAND NEWD AS MAIN SHRTWV EJECTS TOWARD WI. EXTRAOLATION OF SRN EDGE OF THE DEFORMATION ZONE WOULD BRING IT ACRS THE NW PART OF THE FCST AREA. MAIN QUESTIONS FOR SNOW AMNTS CONTINUE TO BE TIMING OF THE CHANGEOVER AND HOW MUCH PCPN FALLS AFTER THAT TIME. NRN STREAM SHRTWV EDGING IN FM THE NW MAY TEND TO DISRUPT THE COMMA HEAD AND NUDGE IT EWD...LIMITING THE AMNT OF PCPN THAT FALLS AFTER THE CHANGEOVER. ON THE OTHER HAND...PCPN COULD BE FALLING QUITE HEAVILY AFTER THE CHANGEOVER...SO THE POTENTIAL IS THERE FOR A PERIOD OF HEAVY SNOW. NEED TO WATCH THIS VERY CLOSELY...BUT LIKELY WON/T BE ABLE TO MAKE ANY HEADLINE CHANGES UNTIL WE START TO SEE THE CHANGEOVER OCCURRING. && .SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 241 PM CDT THU APR 9 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE HEADING NORTHEAST AS IT ENTERS SOUTH-CENTRAL IOWA EARLY THIS AFTERNOON. COMMA HEAD PRECIPITATION IS OCCURRING JUST TO THE REAR OF THE PRIMARY SHORTWAVE LOCATED OVER CENTRAL NEBRASKA...WHERE HEAVY SNOW AND A FEW LIGHTNING STRIKES HAVE BEEN DETECTED. DOWNSTREAM OF THE SYSTEM...A SHORTWAVE IMPULSE IS GENERATING SHOWERS AND THUNDERSTORMS OVER THE EASTERN HALF OF WISCONSIN. MOST OF THE THUNDERSTORM ACTIVITY HAS DIMINISHED AS THEY REACHED THE WAUTOMA TO MANITOWOC CORRIDOR SINCE ELEVATED INSTABILITY HAS NOT BEEN ABLE TO EXTEND THAT FAR NORTH. AS A RESULT...LOOK FOR PERIODS OF SHOWERS AND DRIZZLE TO CONTINUE TO IMPACT THE REGION FOR THE REST OF THE AFTERNOON. THE MAIN FORECAST CONCERNS REVOLVE AROUND HEAVY WINTRY PRECIP ACROSS THE NORTH AND THUNDERSTORM CHANCES OVER THE SOUTH AS A CYCLONE PASSES ACROSS THE REGION TONIGHT. TONIGHT...THE STRONG SHORTWAVE OVER NEBRASKA WILL SWING NORTHEAST AS IT PUSHES A SURFACE LOW FROM THE NORTHWEST CORNER OF ILLINOIS TO CENTRAL LAKE MICHIGAN TO THE STRAITS OF MACKINAC. AHEAD OF THE LOW...ELEVATED INSTABILITY UP TO 500 J/KG MAY SNEAK INTO EAST-CENTRAL WISCONSIN WITHIN A REGION OF STRONG UPWARD MOTION WHICH COULD GENERATE SCATTERED THUNDERSTORMS THOUGH AROUND MID-EVENING. IF THUNDERSTORMS DO OCCUR...SMALL HAIL WILL BE POSSIBLE. TO THE NORTH OF THE LOW...EXCELLENT UPPER DIVERGENCE COMBINED WITH STRONG MID-LEVEL FGEN AND REDUCED STABILITY WILL LEAD TO A HEALTHY DEFORMATION BAND DEVELOPING FROM WEST-CENTRAL TO NORTH-CENTRAL WISCONSIN. THIS DEFORMATION BAND WILL BRING A PROLONGED PERIOD OF MODERATE TO HEAVY PRECIP AT TIMES. WITH TEMPS AND DEWPOINTS IN THE MIDDLE 30S AT THE START OF THE EVENING...PRECIP WILL LIKELY BE ALL RAIN FOR THE FIRST COUPLE HOURS. THEN COLDER AIR WILL GRADUALLY GET DRAWN INTO NORTH-CENTRAL WISCONSIN TO CHANGE PRECIP TO SLEET AND THEN SNOW. BUFKIT SOUNDINGS INDICATE THAT THE NORTH COULD SEE A FEW HOUR PERIOD OF SLEET WHICH COULD LEAD TO DECENT SLEET ACCUMULATIONS GIVEN THE EXPECTED PRECIP RATES. THEN ONCE TEMPS COOL ENOUGH FOR ALL SNOW...SNOWFALL RATES COULD EASILY EXCEED AN INCH PER HOUR AT TIMES. BUT ONE OF THE MOST DIFFICULT ASPECTS OF THIS FORECAST IS IN REGARDS TO HOW QUICKLY THIS CHANGE OVER OCCURS SINCE COLD AIR IS NOT THAT PLENTIFUL TO OUR NORTH. BEST GUESS FROM GUIDANCE INDICATES THIS CHANGE OVER WILL OCCUR LATE THIS EVENING OVER N-C WISCONSIN AND EARLY OVERNIGHT OVER TO CENTRAL WISCONSIN TO THE IRON MOUNTAIN AREA. THE INITIAL RAIN AND SLEET WILL EAT UP SOME OF THE QPF AMOUNTS THIS EVENING...BUT GUIDANCE STILL POINT TOWARDS OVER A HALF INCH FALLING AFTER 06Z. ADDITIONALLY...THE HI-RES MODELS ARE ALSO INDICATING BANDING TAKING PLACE...AND A LITTLE FARTHER TO THE EAST THAN SHOWN PREVIOUSLY. HAVE SHIFTED QPF AND SNOW AMOUNTS TO THE EAST AS A RESULT...WHICH GIVES SNOW AMOUNTS OF 3-6 INCHES FROM LINCOLN AND LANGLADE ON NORTH. A QUARTER TO A HALF INCH OF THAT COULD TURN OUT TO BE SLEET ACCUMULATION. LOCALLY HIGHER AMOUNTS WILL BE POSSIBLE DEPENDING ON WHERE THE SNOW BANDS SET UP. BECAUSE OF THIS UNCERTAINTY...WILL ISSUE A WINTER WEATHER ADVISORY FROM 02Z-13Z. FRIDAY...PRECIP WITH SNOW WEST OF THE FOX VALLEY AND RAIN TO THE EAST WILL DIMINISH EARLY FRIDAY MORNING. SHOULD SEE A CLOUDY AND WINDY START TO THE DAY OTHERWISE. A TRAILING SHORTWAVE WILL PUSH ACROSS SOUTHERN WISCONSIN DURING THE AFTERNOON WHICH COULD CREATE AN ISOLATED SHOWER OVER THE NORTHERN HALF OF THE STATE. LEFT A SMALL CHANCE TO ACCOUNT FOR THIS. HIGHS RANGING FROM THE LOW 40S NORTH TO LOW 50S SOUTH. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 241 PM CDT THU APR 9 2015 PCPN TRENDS SUNDAY/SUNDAY NIGHT AND DURING THE MIDDLE OF NEXT WEEK ARE THE MAIN FCST CONCERNS. HIGH PRESSURE IS EXPECTED TO BUILD INTO THE REGION FRIDAY NIGHT. USED A BLEND OF THE BETTER PERFORMING GUIDANCE SETS FOR MIN TEMPS...BUT WITH THE POTENTIAL FOR A LINGERING SNOW COVER OVER NC WI...HAVE BUMPED MIN TEMPS DOWN THERE. HIGH PRESSURE WILL BRING DRY CONDITIONS SATURDAY AND SATURDAY NIGHT... WITH DEVELOPING SOUTH FLOW RESULTING IN MODERATING TEMPERATURES. A COLD FRONT WILL MOVE INTO WESTERN WI ON SUNDAY AFTERNOON...THEN ACROSS THE FORECAST AREA SUNDAY EVENING. HAVE SLOWED DOWN THE ARRIVAL TIME OF SHOWERS ON SUNDAY AFTERNOON (MAINLY NC/C WI LATE IN THE DAY)...BUT WILL SPREAD HIGH CHC/LOW LIKELY POPS OVER THE ENTIRE CWA SUNDAY NIGHT. H8 LI`S SLIGHTLY BLO ZERO AND STEEP MID- LEVEL LAPSE RATES SUGGEST POTENTIAL FOR AT LEAST ISOLD TSTMS...SO HAVE INCLUDED A SLGT CHC OF TSTMS. HIGH PRESSURE AND AND ASSOCIATED DRY AND MILD CONDITIONS WILL RETURN TO WISCONSIN ON MONDAY AND TUESDAY. THE FCST BECOMES A BIT MUDDLED DURING THE MIDDLE OF THE WEEK...AS SW FLOW ALOFT DEVELOPS AND LOW PRESSURE AND AN ASSOCIATED COLD FRONT EDGE TOWARD THE WESTERN GREAT LAKES. MOST MODELS NOW KEEP TUESDAY NIGHT DRY...WITH THE ECMWF BRINGING PCPN INTO THE REGION ON WEDS...AND THE GFS HOLDING OFF UNTIL ABOUT THURSDAY. GIVEN THE UNCERTAINTY...WILL CARRY CHC POPS THROUGH THIS PERIOD. THE GOOD NEWS IS THAT ANY PCPN THAT OCCURS SHOULD FALL AS ALL RAIN...WHICH IS DEFINITELY A STEP IN THE RIGHT DIRECTION. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 929 PM CDT THU APR 9 2015 MAY NOT NEED TO CARRY THUNDER IN THE 06Z TAFS...WL MAKE AN ISSUANCE TIME DECIDISON ON THAT. OTHERWISE...VERY POOR FLIGHT CONDITIONS DURING THE FIRST PORTION OF THE TAF PERIOD WL GRADUALLY IMPROVE FRIDAY AS THE CYCLONE PULLS AWAY FM THE REGION. && .GRB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 10 AM CDT FRIDAY FOR WIZ011-012. WINTER WEATHER ADVISORY UNTIL 10 AM CDT FRIDAY FOR WIZ019. WINTER WEATHER ADVISORY UNTIL 10 AM CDT FRIDAY FOR WIZ018. WINTER STORM WARNING UNTIL 10 AM CDT FRIDAY FOR WIZ005-010. && $$ UPDATE.........SKOWRONSKI SHORT TERM.....MPC LONG TERM......KIECKBUSCH AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
436 AM MDT WED APR 8 2015 .SHORT TERM...(TODAY THROUGH FRIDAY NIGHT) ISSUED AT 206 AM MDT WED APR 8 2015 TODAY...FIRST CHALLENGE IS THE FOG. AREAS OF FOG HAVE DEVELOPED FROM THE EASTERN SLOPES OF THE LARAMIE RANGE TO CHEYENNE...KIMBALL AND SIDNEY. BASED ON SATELLITE LOOPS AND THE BOUNDARY LAYER MODEL PROGS...EXPECT FOG TO CONTINUE THROUGH MID MORNING BEFORE DISSIPATING. WITH AREAS OF DENSE FOG INCREASING IN COVERAGE FROM CHEYENNE WESTWARD TO THE FOOTHILLS...AS SEEN ON WEBCAMS...WE HAVE OPTED TO ISSUE A DENSE FOG ADVISORY FOR CHEYENNE AND THE EASTERN FOOTHILLS OF THE LARAMIE RANGE THROUGH MID MORNING. IN THE AFTERNOON...PROGRESSIVE SHORTWAVE TROUGH ALOFT MOVES TO CENTRAL WYOMING AND AN INVERTED SURFACE TROUGH EXTENDING FROM LUSK TO PINE BLUFFS. IMPRESSIVE 850 MB THETA-E RIDGE AXIS WILL ALSO BE ALONG THE WYOMING AND NEBRASKA STATE LINE BY LATE AFTERNOON. ALTHOUGH CAPE IS RELATIVELY MINIMAL...ENOUGH DYNAMIC LIFT AND QUASIGEOSTROPHIC LIFT WILL COMBINE WITH SHEAR AND INSTABILITY TO PRODUCE A FEW STRONG TO SEVERE THUNDERSTORMS LATE THIS AFTERNOON AND THIS EVENING ROUGHLY EAST OF A LUSK TO PINE BLUFFS LINE. TONIGHT...THE SHORTWAVE TROUGH ALOFT AND ITS ASSOCIATED COLD FRONT MOVE EASTWARD OVER OUR REGION. WITH DECENT DYNAMICS AND PLENTY OF LOW AND MID LEVEL MOISTURE...WILL SEE WIDESPREAD SHOWERS...ESPECIALLY OVER THE NORTHERN LOCATIONS FROM DOUGLAS TO CHADRON. THURSDAY...AS THE SHORTWAVE TROUGH ALOFT MOVES FURTHER AWAY TO OUR EAST...EXPECT AREAL COVERAGE OF SHOWERS TO DECREASE AS WELL. COOL AND WINDY DAY IN THE WAKE OF THE COLD FRONT FRIDAY AND FRIDAY NIGHT...SURFACE TROUGH EXTENDS FROM NEAR LUSK TO PINE BLUFFS IN THE AFTERNOON. MODELS PAINTING SOME QPF...THOUGH WILL BLEND AND GO ALONG WITH OUR NEIGHBORS KEEPING OUR WEATHER DRY. .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 300 AM MDT WED APR 8 2015 DEPARTING SHORTWAVE FOR SATURDAY WITH BREEZY WINDS AND DRY CONDITIONS EXPECTED. SHOULD BE FAIRLY NICE TEMPERATURE WISE AS 700MB TEMPERATURES REMAIN ABOVE FREEZING. LOOKING AT LOW 70S IN THE PANHANDLE AND LOW 60S WEST OF THE LARAMIE RANGE. CURRENT MODEL RUNS HAVE BACKED OFF ON WINDS FOR SUNDAY/MONDAY TIME FRAME. GFS NOW SHOWING THE STRONGER WINDS BEGINNING TUESDAY NIGHT INTO WEDNESDAY. NEED TO BE WATCHING A SLOW MOVING LOW PRESSURE SYSTEM THE FIRST PART OF NEXT WEEK. GFS AND ECMWF TRACK THIS LOW ACROSS SOUTHERN COLORADO MONDAY WITH WRAP AROUND MOISTURE MAKING IT INTO OUR EASTERN AND CENTRAL ZONES MONDAY AFTERNOON/NIGHT. RIGHT NOW...FORECAST 700MB TEMPERATURES ARE STILL ABOVE FREEZING...SO MUCH OF THIS MOISTURE SHOULD FALL AS LIQUID. BUT IF THEY SHOULD COME IN JUST A FEW DEGREES COLDER OR THE LOW TRACKS A LITTLE FURTHER NORTH...WE COULD BE LOOKING AT SIGNIFICANT SNOW FALL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1102 PM MDT TUE APR 7 2015 IFR/LIFR CONDITIONS EXPECTED ONCE AGAIN OVERNIGHT WITH EAST TO SOUTHEAST UPSLOPE FLOW. HRRR GUIDANCE KEEPS LOW CONDITIONS IN THROUGH MOST OF THE MORNING FOR AREAS EAST OF THE LARAMIE RANGE BEFORE BREAKING AT 17Z OR SO. && .FIRE WEATHER... ISSUED AT 206 AM MDT WED APR 8 2015 MINIMAL CONCERNS AS HUMIDITIES WILL BE ABOVE CRITICAL THRESHOLDS TODAY. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...RUBIN LONG TERM...GCC AVIATION...GCC FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
421 AM MDT WED APR 8 2015 .SHORT TERM...(TODAY THROUGH FRIDAY NIGHT) ISSUED AT 206 AM MDT WED APR 8 2015 TODAY...FIRST CHALLENGE IS THE FOG. AREAS OF FOG HAVE DEVELOPED FROM THE EASTERN SLOPES OF THE LARAMIE RANGE TO CHEYENNE...KIMBALL AND SIDNEY. BASED ON SATELLITE LOOPS AND THE BOUNDARY LAYER MODEL PROGS...EXPECT FOG TO CONTINUE THROUGH MID MORNING BEFORE DISSIPATING. WITH AREAS OF DENSE FOG INCREASING IN COVERAGE FROM CHEYENNE WESTWARD TO THE FOOTHILLS...AS SEEN ON WEBCAMS...WE HAVE OPTED TO ISSUE A DENSE FOG ADVISORY FOR CHEYENNE AND THE EASTERN FOOTHILLS OF THE LARAMIE RANGE THROUGH MID MORNING. IN THE AFTERNOON...PROGRESSIVE SHORTWAVE TROUGH ALOFT MOVES TO CENTRAL WYOMING AND AN INVERTED SURFACE TROUGH EXTENDING FROM LUSK TO PINE BLUFFS. IMPRESSIVE 850 MB THETA-E RIDGE AXIS WILL ALSO BE ALONG THE WYOMING AND NEBRASKA STATE LINE BY LATE AFTERNOON. ALTHOUGH CAPE IS RELATIVELY MINIMAL...ENOUGH DYNAMIC LIFT AND QUASIGEOSTROPHIC LIFT WILL COMBINE WITH SHEAR AND INSTABILITY TO PRODUCE A FEW STRONG TO SEVERE THUNDERSTORMS LATE THIS AFTERNOON AND THIS EVENING ROUGHLY EAST OF A LUSK TO PINE BLUFFS LINE. TONIGHT...THE SHORTWAVE TROUGH ALOFT AND ITS ASSOCIATED COLD FRONT MOVE EASTWARD OVER OUR REGION. WITH DECENT DYNAMICS AND PLENTY OF LOW AND MID LEVEL MOISTURE...WILL SEE WIDESPREAD SHOWERS...ESPECIALLY OVER THE NORTHERN LOCATIONS FROM DOUGLAS TO CHADRON. THURSDAY...AS THE SHORTWAVE TROUGH ALOFT MOVES FURTHER AWAY TO OUR EAST...EXPECT AREAL COVERAGE OF SHOWERS TO DECREASE AS WELL. COOL AND WINDY DAY IN THE WAKE OF THE COLD FRONT FRIDAY AND FRIDAY NIGHT...SURFACE TROUGH EXTENDS FROM NEAR LUSK TO PINE BLUFFS IN THE AFTERNOON. MODELS PAINTING SOME QPF...THOUGH WILL BLEND AND GO ALONG WITH OUR NEIGHBORS KEEPING OUR WEATHER DRY. .FIRE WEATHER...MINIMAL CONCERNS AS HUMIDITIES WILL BE ABOVE CRITICAL THRESHOLDS TODAY. .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 300 AM MDT WED APR 8 2015 DEPARTING SHORTWAVE FOR SATURDAY WITH BREEZY WINDS AND DRY CONDITIONS EXPECTED. SHOULD BE FAIRLY NICE TEMPERATURE WISE AS 700MB TEMPERATURES REMAIN ABOVE FREEZING. LOOKING AT LOW 70S IN THE PANHANDLE AND LOW 60S WEST OF THE LARAMIE RANGE. CURRENT MODEL RUNS HAVE BACKED OFF ON WINDS FOR SUNDAY/MONDAY TIME FRAME. GFS NOW SHOWING THE STRONGER WINDS BEGINNING TUESDAY NIGHT INTO WEDNESDAY. NEED TO BE WATCHING A SLOW MOVING LOW PRESSURE SYSTEM THE FIRST PART OF NEXT WEEK. GFS AND ECMWF TRACK THIS LOW ACROSS SOUTHERN COLORADO MONDAY WITH WRAP AROUND MOISTURE MAKING IT INTO OUR EASTERN AND CENTRAL ZONES MONDAY AFTERNOON/NIGHT. RIGHT NOW...FORECAST 700MB TEMPERATURES ARE STILL ABOVE FREEZING...SO MUCH OF THIS MOISTURE SHOULD FALL AS LIQUID. BUT IF THEY SHOULD COME IN JUST A FEW DEGREES COLDER OR THE LOW TRACKS A LITTLE FURTHER NORTH...WE COULD BE LOOKING AT SIGNIFICANT SNOW FALL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1102 PM MDT TUE APR 7 2015 IFR/LIFR CONDITIONS EXPECTED ONCE AGAIN OVERNIGHT WITH EAST TO SOUTHEAST UPSLOPE FLOW. HRRR GUIDANCE KEEPS LOW CONDITIONS IN THROUGH MOST OF THE MORNING FOR AREAS EAST OF THE LARAMIE RANGE BEFORE BREAKING AT 17Z OR SO. && .FIRE WEATHER... ISSUED AT 206 AM MDT WED APR 8 2015 MINIMAL CONCERNS AS HUMIDITIES WILL BE ABOVE CRITICAL THRESHOLDS TODAY. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...RUBIN LONG TERM...GCC AVIATION...GCC FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1104 PM MDT TUE APR 7 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 230 PM MDT TUE APR 7 2015 MAIN FORECAST CONCERN CONTINUES TO BE THE PACIFIC STORM SYSTEM CURRENTLY NEAR THE NORTHERN CALIFORNIA COASTLINE FOR WEDNESDAY AND THURSDAY. FOR TODAY...LOW STRATUS CLOUD DECK STILL LINGERING ACROSS WESTERN NEBRASKA AS FAR WEST AS SCOTTSBLUFF. THE FOG HAS LIFTED FROM THIS MORNING...BUT EXPECT THE FOG TO REFORM TONIGHT. CURRENT KCYS RADAR LOOP SHOWS SOME RAIN SHOWERS DEVELOPING NEAR AND SLIGHTLY EAST OF THE LARAMIE RANGE THIS AFTERNOON. CAN NOT RULE OUT SOME THUNDER INTO THIS EVENING...SO KEPT ISOLATED THUNDER WITH A 20 TO 30 PERCENT CHANCE OF RAIN SHOWERS MAINLY ALONG AND EAST OF THE LARAMIE RANGE. THE BEST CHANCE APPEARS TO BE EAST OF I25. FOR TONIGHT...ISOLATED RAIN SHOWERS ACTIVITY ACROSS THE HIGH PLAINS WILL GRADUALLY DISSIPATE OVERNIGHT. FOG WILL REFORM AND POTENTIALLY PUSH AS FAR WEST AS THE LARAMIE RANGE FOOTHILLS. MODEL SOUNDINGS ARE MARGINAL FOR SOME DRIZZLE ACROSS WESTERN NEBRASKA...BUT KEPT LOW POP AND PATCHY/OCCASIONAL DRIZZLE FOR NOW. DRY AIR JUST ABOVE 750 MB MAY PREVENT WIDESPREAD DRIZZLE FROM DEVELOPING HOWEVER. MODELS ARE COMING INTO SLIGHTLY BETTER AGREEMENT REGARDING THE NORTHWARD TRACK OF THIS STORM SYSTEM...AS THE UPPER LEVEL TROUGH AXIS INITIALLY MOVES OVER WYOMING...AND THEN DIGS A BIT SOUTHEAST WEDNESDAY NIGHT DUE TO CYCLOGENESIS OVER EASTERN COLORADO AND WESTERN KANSAS. WITH THE MORE NORTHWARD TRACK AND RELATIVE PROGRESSIVE NATURE OF THE SYSTEM...SNOWFALL APPEARS TO BE MUCH LESS OF A CONCERN COMPARED TO 3 TO 4 DAYS AGO. IN FACT...SOME AREAS FURTHER SOUTH WILL BE LUCKY TO GET ANYTHING AT ALL FROM THIS SYSTEM. HOWEVER...TSTORMS MAY DEVELOP ACROSS THE FORECAST AREA EARLY WEDNESDAY AFTERNOON AND SOME MAY BECOME STRONG OVER THE HIGH PLAINS. CAPE VALUES AND LI/S ARE NOT TOO IMPRESSIVE...BUT THERE IS SOME DYNAMIC FORCING WITH THIS STORM SYSTEM. DYNAMICS AND STRONG WIND SHEAR MAY BE JUST ENOUGH TO TRIGGER A FEW STRONGER STORMS EAST OF THE LARAMIE RANGE...WITH THE BEST CHANCE OVER WESTERN NEBRASKA. SOME OF THESE SHOWERS AND STORMS WILL CONTAIN BRIEF HEAVY RAINFALL...HAIL...AND GUSTY WINDS AS THEY MOVE NORTHEAST INTO WEDNESDAY EVENING. THE GFS...NAM...AND GEM ALL SHOW A DRY SLOT MOVING ALONG THE I80 CORRIDOR WHILE THE ECMWF SHOWS THE PRECIPITATION MORE WIDESPREAD OVER THE HIGH PLAINS. KEPT POP ABOVE 60 PERCENT FURTHER NORTH AND EAST...MAINLY NORTH OF I80 WITH LOWER POP NEAR THE COLORADO BORDER. COLDER AIR BEHIND THE PACIFIC COLD FRONT PUSHES INTO THE AREA WEDNESDAY EVENING FROM WEST TO EAST...WITH RAINFALL CHANGING TO SNOW FROM RAWLINS TO LARAMIE AROUND SUNSET. THIS COLDER AIR WILL NOT MAKE IT INTO THE HIGH PLAINS UNTIL LATE WEDNESDAY EVENING. SNOW LEVELS APPEARS TO BE LOWER AROUND 4500 FEET BY EARLY THURSDAY. MODELS INDICATE THAT THIS STORM SYSTEM WILL RAPIDLY MOVE EAST INTO THE GREAT PLAINS ON THURSDAY...GREATLY LIMITING SNOWFALL AMOUNTS. EXPECT MAYBE 1 TO 2 INCHES OF SNOW WEST OF THE LARAMIE RANGE WITH 3 TO 6 INCHES OVER THE MOUNTAINS. FOR THE HIGH PLAINS...GENERALLY A DUSTING TO UP TO ONE INCH OF SNOW IS POSSIBLE...MAINLY NEAR THE LARAMIE RANGE AND AROUND THE PINE AND CHEYENNE RIDGE. HIGH TEMPERATURES ON THURSDAY WILL BE COOLER...BUT STILL IN THE 40S FOR HIGHS DUE TO SOME LATE DAY SUNSHINE. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 212 PM MDT TUE APR 7 2015 A FEW MINOR MODEL DIFFERENCES EARLY IN THE FCST PERIOD WITH THE GFS SHOWING A WEAK MID LEVEL SHORTWAVE DRIFTING ACROSS CENTRAL MT ON FRI AFTN. THE ECMWF SUGGESTS BROAD RIDGING AND SUBSIDENCE ALOFT...WHICH WOULD TEND TO BE THE WARMER AND DRIER SOLUTION. THIS IS THE OUTLIER ATTM SO HAVE KEPT TEMPS ON THE COOLER SIDE OF AVAILABLE GUIDANCE AND MAINTAINED MENTION OF ISOLATED SHOWERS OVER THE MOUNTAINS. A QUASI- ZONAL FLOW PATTERN WILL GOVERN THE PATTERN THROUGH THE WEEKEND INTO EARLY NEXT WEEK. H7-H3 RH PROGS FROM THE GFS/ECM/GEM ALL SUGGEST WE SHOULD SEE MORE SUNSHINE AS A TRANSITORY RIDGE PASSES OVER THE AREA AHEAD OF THE NEXT SYSTEM. H7 TEMPS AROUND 3-5 C AND LOW LEVEL DOWNSLOPE FLOW WILL HELP YIELD 65-75 DEGREE READINGS EAST OF THE LARAMIE RANGE ON SAT AFTN. A FAIRLY POTENT SHORTWAVE WILL MOVE FROM THE PACIFIC NORTHWEST INTO THE NORTHERN AND CENTRAL ROCKIES ON SUN/MON. MEDIUM RANGE GUIDANCE DIFFERS WITH THE TIMING AND AMPLITUDE OF THIS SYSTEM WITH THE GFS KEEPING MOST OF THE ENERGY TO OUR NORTH. THAT IS WHERE THE HIGHER CHANCES FOR PCPN COULD REMAIN AS WELL. DEFINITELY LOOKING AT A WINDIER STRETCH OF DAYS SUN/MON WITH INCREASING H7-H5 GRADIENTS AND RESULTANT STRONG FLOW ALOFT. OVERALL EXPECT A PERIOD OF SEASONAL WEATHER CONDITIONS WITH MINIMAL CHANCES FOR PCPN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1102 PM MDT TUE APR 7 2015 IFR/LIFR CONDITIONS EXPECTED ONCE AGAIN OVERNIGHT WITH EAST TO SOUTHEAST UPSLOPE FLOW. HRRR GUIDANCE KEEPS LOW CONDITIONS IN THROUGH MOST OF THE MORNING FOR AREAS EAST OF THE LARAMIE RANGE BEFORE BREAKING AT 17Z OR SO. && .FIRE WEATHER... ISSUED AT 212 PM MDT TUE APR 7 2015 LOW FIRE WEATHER CONCERNS FOR THE REST OF THIS WEEK AS A PACIFIC STORM SYSTEM IMPACTS THE REGION STARTING TOMORROW. COOLER TEMPERATURES ARE EXPECTED ALONG WITH HIGHER RELATIVE HUMIDITIES THROUGH FRIDAY. THERE IS A DECENT CHANCE OF RAIN SHOWERS AND TSTORMS ON WEDNESDAY AS WELL...MAINLY ACROSS WESTERN NEBRASKA. DRIER WEATHER IS EXPECTED THIS WEEKEND WITH WARMER TEMPERATURES AND RELATIVE HUMIDITIES TRENDING LOWER. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...TJT LONG TERM...CLH AVIATION...GCC FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
323 AM MDT FRI APR 10 2015 .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 323 AM MDT FRI APR 10 2015 WLY FLOW ALOFT WILL BE OVER THE AREA THRU TONIGHT AS A WK DISTURBANCE MOVES ACROSS LATE THIS AFTN AND EVENING. THERE WILL BE QUITE A BIT OF MOISTURE ABV 500 MB WITH LAPSE RATES AOB 8 C/KM. HOWEVER CAPES ARE FCST TO BE ONLY IN THE 100-200 J/KG RANGE MAINLY OVER THE HIGHER TERRAIN. AT THIS TIME IT LOOKS LIKE PCPN WILL BE IN THE FORM OF WDLY SCT HIGH BASED SHOWERS WITH THE FOCUS MAINLY OVER THE HIGHER TERRAIN AND ACROSS THE PALMER DIVIDE. FOR THIS EVENING THE HIGH BASED SHOWERS SHOULD GRADUALLY END BEFORE MIDNIGHT. AS FOR HIGHS THIS AFTN READINGS WILL RISE BACK INTO THE LOWER TO MID 60S OVER NERN CO. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 323 AM MDT FRI APR 10 2015 WARM AND DRY WEATHER WILL PREVAIL SATURDAY AND SUNDAY. LIGHT WEST/SOUTHWEST FLOW ALOFT AND WARM ADVECTION WILL OCCUR SATURDAY...PUSHING HIGHS INTO THE LOWER TO MID 70S OVER THE PLAINS...WITH UPPER 50S AND 60S MOUNTAIN VALLEYS AND FOOTHILLS...AND 40S IN HIGHER MOUNTAIN AREAS. OVERNIGHT LOWS SATURDAY NIGHT WILL BE QUITE MILD ESPECIALLY IN/NEAR THE FRONT RANGE AS DOWNSLOPE FLOW INCREASES AHEAD OF A SHORT WAVE. THIS SHORT WAVE MOVES ACROSS THE NORTHERN ROCKIES SUNDAY...PUSHING A WEAK COLD FRONT ACROSS NORTHEAST COLORADO BY LATE IN THE DAY. THERE IS ONLY SLIGHT COOLING AND LITTLE IF ANY MOISTENING WITH THIS FRONT. AS A RESULT...SUNDAY WILL FEATURE CONTINUED WARM AND DRY CONDITIONS WITH POTENTIAL FOR FIRE WEATHER CONCERNS...SEE FIRE WEATHER SECTION BELOW. DRY CONDITIONS WILL PREVAIL MONDAY AND TUESDAY AS THERE IS MORE AGREEMENT AS DISCUSSED YESTERDAY THAT THE EJECTING TROUGH FROM BAJA WILL STAY TOO FAR SOUTH TO AFFECT THE FORECAST AREA. TEMPERATURES WILL AVERAGE WELL ABOVE NORMAL WITH HIGHS LIKELY PUSHING INTO THE LOWER TO MID 70S ON THE PLAINS AGAIN BY TUESDAY. THEN ATTENTION TURNS TOWARD NEXT POTENTIAL STORM SYSTEM MOVING IN FROM THE PACIFIC. THERE IS GOOD AGREEMENT THAT THIS SYSTEM WILL MOVE INTO THE PACIFIC NORTHWEST BY MONDAY NIGHT...BUT THEN CONSIDERABLE MODEL SPREAD EXISTS FROM THERE. SOME DRIVE IT TOWARD THE FOUR CORNERS AREA WHILE OTHERS LIKE THE ECMWF MAINTAIN A MUCH MORE OPEN AND PROGRESSIVE WAVE. HARD TO GET CAUGHT UP IN ANY DETAILS AT THIS TIME CONSIDERING THE AMOUNT OF SPREAD EVEN IN THE GFS ENSEMBLE GUIDANCE. WILL HAVE POPS JUST ABOVE CLIMATOLOGY AS THERE IS GENERAL AGREEMENT WITH REGARD TO AT LEAST A TROUGH IN THE VICINITY. && .AVIATION...(FOR THE TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 323 AM MDT FRI APR 10 2015 WINDS HAVE BECOME SLY EARLY THIS MORNING AND MAY BECOME LIGHT WSW BY 15Z. BOTH THE HRRR AND RAP HAVE A WK DENVER CYCLONE DEVELOPING BY 18Z GENERALLY SOUTH OF THE AIRPORT. IF THIS OCCURS THEN WINDS MAY TREND TOWARDS A MORE ENE COMPONENT FOR THE AFTN HOURS. BY EARLY EVENING THE CYCLONE IS FCST TO BECOME MORE DIFFUSE WITH DRAINAGE WINDS DEVELOPING BY 06Z. VFR CONDITIONS WILL BE IN PLACE TODAY THRU TONIGHT ALTHOUGH THERE WILL BE A MID LVL CLOUD DECK FM MID AFTN THRU THE EARLY EVENING HOURS. && .FIRE WEATHER... ISSUED AT 323 AM MDT FRI APR 10 2015 LOW HUMIDITIES WILL OCCUR SATURDAY AFTERNOON. WHILE SOUTHWEST WINDS INCREASE SLIGHTLY...THEY WILL STAY UNDER RED FLAG CRITERIA. ON SUNDAY...GUSTY WEST/NORTHWEST WINDS WILL LIKELY DEVELOP IN MOST AREAS BY MID DAY WITH INCREASED MIXING AND APPROACH OF COLD FRONT. HUMIDITIES ARE NOT EXPECTED TO INCREASE MUCH WITH THIS DRY FRONT...SO SOME POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS DEVELOPING ACROSS THE FORECAST AREA SUNDAY LATE MORNING THROUGH THE AFTERNOON. PEAK GUSTS SHOULD MOSTLY BE IN THE 20-30 MPH RANGE WITH THE STRONGEST GUSTS IN THE FOOTHILLS AND OVER THE NORTHEASTERN PLAINS. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RPK LONG TERM...BARJENBRUCH AVIATION...RPK FIRE WEATHER...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS ALBANY NY
503 AM EDT FRI APR 10 2015 .SYNOPSIS... A WARM FRONT WILL MOVE NORTHWARD ACROSS THE REGION THIS MORNING...BRINGING RAIN AND A FEW THUNDERSTORMS. A MILDER AIR MASS WILL BRIEFLY BUILD IN FOR THIS AFTERNOON...BEFORE A COLD FRONT MOVES ACROSS THE REGION LATER THIS AFTERNOON AND EARLY EVENING WITH MORE SHOWERS AND ISOLATED THUNDERSTORMS. MAINLY DRY AND BRISK CONDITIONS OPEN THE WEEKEND...WITH JUST A FEW SHOWERS NORTH AND WEST OF THE CAPITAL REGION. SUNNY AND MILD CONDITIONS ARE THEN EXPECTED FOR SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ...FREEZING RAIN ADVISORY REMAINS IN EFFECT UNTIL 6 AM EDT TODAY FOR ELEVATIONS ABOVE 1200 FT IN SOUTHERN VT AND WESTERN MA... AS OF 455 AM EDT...SEVERAL AREAS OF LIGHT TO MODERATE RAIN...ALONG WITH A FEW EMBEDDED CONVECTIVE ELEMENTS...CONTINUE TO TRANSLATE NORTHEAST ACROSS THE REGION...WITH THE MOST CONCENTRATED AREA OF RAINFALL EXTENDING FROM THE SE CATSKILLS ACROSS THE MID HUDSON VALLEY INTO NW CT AND WESTERN MA. MEANWHILE...RECENT MESONET OBS...AND ALSO INFORMATION FROM THE 00Z/10 KALY SOUNDING INDICATE A PERSISTENT SUBFREEZING LAYER GENERALLY ABOVE 1200 FT ACROSS SOUTHERN VT AND WESTERN MA. THIS WILL LIKELY CONTRIBUTE TO AREAS OF FREEZING RAIN ACROSS HIGHER ELEVATIONS OF EASTERN BERKSHIRE CO...EASTERN BENNINGTON CO...AND WEST CENTRAL WINDHAM COS...MAINLY FOR ELEVATIONS ABOVE 1200 FT...THROUGH 6 AM THIS MORNING. IN THESE AREAS...SOME ICE ACCRETION OF UP TO ONE QUARTER OF AN INCH WILL BE POSSIBLE. ELSEWHERE...PERIODS OF RAIN SHOULD CONTINUE THROUGH DAYBREAK...ALONG WITH THE POSSIBILITY OF A FEW RUMBLES OF THUNDER. THE OVERALL AREAL COVERAGE OF RAIN SHOULD DECREASE BETWEEN ROUGHLY 8 AM AND 11 AM FROM SW TO NE ACROSS THE REGION...AS THE INITIAL LOW LEVEL JET SHIFTS NORTHWARD...AND THE BETTER UPPER LEVEL DYNAMICS AND LIFT CLOSER TO THE SFC COLD FRONT REMAIN TO THE WEST. SO A SLIGHT LULL IN PRECIP IS QUITE POSSIBLE LATER THIS MORNING INTO EARLY AFTERNOON. DURING THIS LULL...SOME BREAKS IN THE CLOUDS COULD DEVELOP...PARTICULARLY ACROSS THE EASTERN CATSKILLS...SCHOHARIE VALLEY AND AREAS JUST S OF THE CAPITAL REGION...AS 925-850 HPA WINDS VEER INTO THE SOUTHWEST...AND SOME DOWNSLOPING FROM THE CATSKILLS CONTRIBUTES TO SOME WARMING/DRYING. ELSEWHERE...THE COLD STABLE BOUNDARY LAYER WILL LIKELY PERSIST LONGER...PERHAPS WELL INTO THE AFTERNOON ACROSS PORTIONS OF THE UPPER HUDSON VALLEY/LAKE GEORGE REGION...AND ALSO SE VT. EVENTUALLY...SHOWERS AND SOME EMBEDDED THUNDERSTORMS WILL PRECEDE AND ACCOMPANY THE COLD FRONT AS IT TRACKS EASTWARD LATER THIS AFTERNOON. AT THIS TIME...IT APPEARS THAT INSTABILITY SHOULD REMAIN RATHER WEAK...AND ALSO THE STRONGER UPPER LEVEL DYNAMICS PASS MAINLY TO OUR N AND W. HIGHER RES MODELS SUGGEST THAT AREAL COVERAGE OF SHOWERS/THUNDERSTORMS WITH THE COLD FRONT REMAINS GENERALLY ISOLATED TO SCATTERED. WILL INDICATE MAINLY HIGH CHC POPS FOR THIS AFTERNOON...WITH SOME AREAS OF LIKELY POPS ACROSS SOUTHERN AREAS...AS WELL AS ACROSS THE WESTERN ADIRONDACKS. TEMPS WILL BE VERY TRICKY TODAY GIVEN THE INITIAL COLD AND STABLE BOUNDARY LAYER AND PERSISTENT LOW LEVEL NORTHEAST AGEOSTROPHIC WINDS. HOWEVER...TEMPS SHOULD EVENTUALLY RISE THIS AFTERNOON...WITH 50S TO LOWER 60S EXPECTED IN VALLEY AREAS FROM ALBANY SOUTH...AND MAINLY 40S AND 50S TO THE NORTH AND ACROSS MOST HIGHER ELEVATIONS. THE WARMEST AREAS MAY ULTIMATELY BE ACROSS PORTIONS OF THE CATSKILLS/SCHOHARIE VALLEY...ESP SHOULD ANY BREAKS OF SUN DEVELOP. MAX TEMPS MAY REACH 60-65 OR WARMER IN THESE AREAS. WINDS WILL REMAIN BRISK FROM THE SOUTH TO SOUTHEAST THIS MORNING AT 15-25 MPH...ESP ACROSS HIGHER ELEVATIONS OF THE TACONICS/GREENS AND BERKSHIRES. WINDS WILL BECOME SOUTH TO SOUTHWEST AT SIMILAR SPEEDS THIS AFTERNOON. AS THE FRONT PASSES...EVEN STRONGER WIND GUSTS WILL BE POSSIBLE...ESP ACROSS THE WESTERN ADIRONDACKS WHERE SOME GUSTS OF 35-45 MPH COULD OCCUR. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... TONIGHT...EVENING SHOWERS WILL REMAIN POSSIBLE FOR AREAS NEAR AND E OF THE HUDSON RIVER VALLEY. SKIES SHOULD THEN BECOME CLEAR TO PARTLY CLOUDY...BEFORE CLOUDS AND SOME RAIN/SNOW SHOWERS INCREASE ACROSS THE WESTERN ADIRONDACKS AS THE MAIN UPPER LEVEL TROUGH APPROACHES. SOME LIGHT SNOWFALL ACCUMS OF AN INCH OR LESS WILL BE POSSIBLE IN THESE AREAS. MIN TEMPS SHOULD FALL INTO THE 30S TO LOWER 40S. SATURDAY...THE AFOREMENTIONED UPPER LEVEL TROUGH WILL MOVE ACROSS THE REGION IN THE MORNING. THIS WILL BRING A PERIOD OF CLOUDS...AND ISOLATED TO SCATTERED SHOWERS OF RAIN/SNOW...MAINLY ACROSS THE ADIRONDACKS...MOHAWK VALLEY...UPPER HUDSON VALLEY AND SOUTHERN VT. SHOWERS SHOULD DECREASE IN AREAL COVERAGE IN THE AFTERNOON AS THE TROUGH PASSES. HOWEVER...WINDS WILL REMAIN RATHER STRONG THROUGH SATURDAY AS DEEP MIXING OCCURS. EXPECT WIND GUSTS TO REACH 35-45 MPH IN MANY AREAS FROM LATE MORNING INTO THE AFTERNOON...STRONGEST IN CLOSE PROXIMITY TO THE MOHAWK RIVER VALLEY/CAPITAL REGION AND BERKSHIRES. MAX TEMPS SHOULD REACH THE LOWER/MID 50S IN VALLEYS...AND 40S ACROSS HIGHER TERRAIN...ALTHOUGH SOME OF THE HIGHER PEAKS OF THE SOUTHERN ADIRONDACKS AND SOUTHERN VT MAY ONLY REACH THE 30S. SAT NT-SUNDAY...HIGH PRESSURE BUILDS IN FROM THE SOUTHWEST...ALLOWING FOR MAINLY CLEAR SKIES SAT NT...AND SUNNY SKIES ON SUNDAY. SAT NT/SUN AM MINS WILL BE RATHER COOL...GENERALLY IN THE 20S TO LOWER 30S. SUN AFTERNOON MAXES SHOULD BE QUITE MILD WITH LIGHT WINDS...WITH LOWER/MID 60S IN VALLEYS AND MAINLY 50S ACROSS HIGHER ELEVATIONS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... WE BEGIN THIS LONG TERM PORTION OF THE FORECAST UNDER TRANQUIL CONDITIONS AS SURFACE HIGH SLIDES OFF THE MIDDLE ATLANTIC COAST SUNDAY NIGHT. THIS WILL KEEP SKIES MOSTLY CLEAR WITH NEAR SEASONABLE TEMPERATURES. MEANWHILE...RATHER STRONG AND FAST MOVING PACIFIC ENERGY COMES ASHORE ACROSS THE PACIFIC NORTHWEST AND EJECTS OUT ONTO THE NORTHERN PLAINS. AS THE SURFACE HIGH SLIDES WELL OFFSHORE...THE RETURN FLOW COMBINING WITH THE AFOREMENTIONED PACIFIC ENERGY WILL ALLOW DEEPER MOISTURE TRANSPORT FROM THE GULF TO BECOME ENTRAINED ACROSS THE MISSISSIPPI RIVER VALLEY FOR EARLY NEXT WEEK. THE IMPACT FOR OUR REGION WILL BE AN INCREASE IN CLOUD COVERAGE THROUGH MONDAY WITH THE CHANCE OF SHOWERS ARRIVING MONDAY NIGHT WITH THE FRONTAL BOUNDARY. QPF FROM THE GLOBAL MODELS CONTINUE TO SHOW TRENDS OF A BIT HIGHER AMOUNTS. IN THE WAKE OF THE FROPA...IMPROVING CONDITIONS EXPECTED THROUGH THE DAY TUESDAY. HOWEVER..CYCLONIC FLOW ALOFT MAY KEEP CLOUDS AND ISOLATED SHOWERS ACROSS THE TERRAIN. TEMPERATURES WILL BE SEASONABLE COOL WITH MAINLY 50S AND LOWER 60S EXPECTED. TUESDAY NIGHT INTO THURSDAY...HIGH PRESSURE FROM THE SURFACE TO ALOFT WILL NOT ONLY KEEP OUR WEATHER TRANQUIL...BUT WITH THERMAL PROFILES MODERATING AND MID APRIL SUNSHINE IT WILL FEEL MORE LIKE SPRING THROUGH THE MID WEEK PERIOD. AVERAGE HIGHS CLIMB WELL INTO THE 60S FOR VALLEY LOCATIONS AND PERHAPS NEAR 70F WITH FAVORABLE DOWNSLOPING WITHIN THE DEVELOPING SOUTHWEST FLOW REGIME AND OVERNIGHT LOWS FROM THE 30S ACROSS THE TERRAIN TO 40S ELSEWHERE. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... COMBINATION OF MVFR/IFR FLIGHT CONDITIONS THE REMAINDER OF THE OVERNIGHT AS WARM FRONT SLOWLY LIFTS NORTHWARD WITH OCCASIONAL SHOWERS/PERIODS OF RAIN. AS MENTIONED IN THE PREVIOUS EXCELLENT DISCUSSION...LLWS WILL BECOME AN ISSUE AS EVIDENT IN THE LATEST VWP FROM THE RADAR AND HAVE CONTINUED THE MENTION IN THE LATEST FORECASTS OVERNIGHT. DURING THE DAYLIGHT HOURS FRIDAY...PER THE HRRR AND 4KM SPC WRF REFLECTIVITY FORECASTS...SEEMS THERE WILL BE A REDUCTION IN PRECIP COVERAGE AS WARM FRONT LIFTS NORTHWARD. LATER IN THE DAY...COLD FRONT WILL APPROACH WITH A CHC-SCT CONVECTION ALONG THE BOUNDARY. FOR NOW...WE WILL PLACE A PROB30 AND MONITOR TRENDS. FLIGHT CONDITIONS SHOULD IMPROVE TO AT LEAST MVFR THROUGH THE DAY. FRIDAY EVENING WITH FROPA...WINDS WILL QUICKLY SHIFT FROM THE WESTERLY DIRECTION WITH FLIGHT CONDITIONS IMPROVING TO VFR. THE EXCEPTION TO THIS WOULD BE INTO KPSF WHERE UPSLOPE CONDITIONS MAY LINGER MVFR CIGS A BIT LONGER. OUTLOOK... SATURDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY NO SIG WX. SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. MONDAY: NO OPERATIONAL IMPACT. NO SIG WX. MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS ANTICIPATED THROUGH TODAY DUE TO EXPECTED WET AND UNSETTLED CONDITIONS AND MAINLY COOL WEATHER. A WARM FRONT WILL MOVE NORTHWARD ACROSS THE REGION THIS MORNING...BRINGING RAIN AND A FEW THUNDERSTORMS. A MILDER AIR MASS WILL BRIEFLY BUILD IN FOR THIS AFTERNOON...BEFORE A COLD FRONT MOVES ACROSS THE REGION LATER THIS AFTERNOON AND EARLY EVENING WITH MORE SHOWERS AND ISOLATED THUNDERSTORMS. MAINLY DRY AND BRISK CONDITIONS OPEN THE WEEKEND...WITH JUST A FEW SHOWERS NORTH AND WEST OF THE CAPITAL REGION. SUNNY AND MILD CONDITIONS ARE THEN EXPECTED FOR SUNDAY. && .HYDROLOGY... A WARM FRONT WILL LIFT NORTHWARD ACROSS THE REGION TODAY...BEFORE A COLD FRONT MOVES ACROSS FROM THE WEST THIS AFTERNOON AND EVENING. PERIODS OF RAIN...ALONG WITH A FEW THUNDERSTORMS...WILL OCCUR WITH THESE FEATURES TODAY. RAINFALL AMTS OVERNIGHT GENERALLY RANGED FROM ONE QUARTER TO ONE HALF INCH. ANOTHER ONE TENTH TO ONE QUARTER INCH OF RAINFALL IS EXPECTED THROUGH TODAY. THE LATEST MMEFS /ENSEMBLE GUIDANCE/ INDICATES RIVER LEVELS WILL RISE BY EARLY IN THE WEEKEND...WITH SEVERAL POINTS POTENTIALLY APPROACHING ACTION STAGE. THE ONLY POINT THAT MAY REACH MINOR FLOOD STAGE IS GILBOA. WE WILL CONTINUE TO WATCH THE POTENTIAL FOR RIVER RISES OVER THE NEXT DAY OR TWO. WIDESPREAD FLOODING IS NOT EXPECTED AT THIS TIME...BUT SIGNIFICANT WITHIN BANK RISES ARE POSSIBLE. COOLER AND DRIER WEATHER RETURNS ON SATURDAY...ALTHOUGH A FEW PASSING RAIN OR SNOW SHOWERS WILL BE POSSIBLE PRODUCING QPF OF LESS THAN ONE TENTH OF AN INCH. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...FREEZING RAIN ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR MAZ001-025. VT...FREEZING RAIN ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR VTZ013>015. && $$ SYNOPSIS...KL/WASULA NEAR TERM...KL SHORT TERM...KL LONG TERM...BGM AVIATION...FRUGIS/BGM FIRE WEATHER...KL/BGM/WASULA HYDROLOGY...KL/BGM/WASULA
AREA FORECAST DISCUSSION
NWS TAUNTON MA
323 AM EDT FRI APR 10 2015 .SYNOPSIS... A WARM FRONT WILL LIFT ACROSS THE REGION THIS AFTERNOON BRINGING MILDER TEMPS...BUT ONE LAST ROUND OF SHOWERS IS EXPECTED LATER TODAY INTO THIS EVENING AS A COLD FRONT MOVES THROUGH. HIGH PRESSURE WILL BRING SEASONABLY MILD TEMPS AND DRY WEATHER FOR THE WEEKEND. A COLD FRONT MAY BRING SHOWERS MONDAY NIGHT FOLLOWED BY DRY AND MORE SEASONABLE WEATHER THROUGH MIDWEEK. && .NEAR TERM /THROUGH TODAY/... AREA OF RAIN ASSOCD WITH 850 MB WARM FRONT AND NOSE OF THE LOW LEVEL JET MOVING ACROSS SNE EARLY THIS MORNING. HRRR HAS A GOOD HANDLE ON THE RAIN AND MOVES IT OUT 10-14Z AS AREA OF MID LEVEL DRYING MOVES IN. THIS WILL RESULT IN A PERIOD OF MAINLY DRY WEATHER MID MORNING INTO THE AFTERNOON BEFORE NEXT ROUND OF SHOWERS MOVE IN LATER AFTERNOON AND EVENING ASSOCD WITH THE COLD FRONT WHICH MOVES INTO W NEW ENG BY EARLY EVENING. MODELS INDICATE MARGINAL ELEVATED INSTABILITY...ESPECIALLY NEAR THE COAST WHERE LOW RISK FOR ISOLD TSTMS. IN FACT...SOME OF THE HI-RES GUIDANCE IS SUGGESTING SOME LOCALLY HEAVY RAINFALL LATE AFTERNOON/EVENING GIVEN PWATS INCREASING TO 1.5" AHEAD OF THE FRONT WHICH IS +3 SD ABOVE CLIMO. SFC WARM FRONT STILL BACK ACROSS CENTRAL NY AND WILL PROBABLY TAKE UNTIL THE AFTERNOON BEFORE IT MOVES THROUGH. THIS WILL RESULT IN AREAS OF STRATUS AND FOG PERSISTING TODAY. TEMPS WILL REMAIN COOL THIS MORNING...BUT WILL SHOOT UP INTO THE 50S DURING THE AFTERNOON AS THE FRONT LIFTS TO THE N. && .SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/... TONIGHT... FOCUS FOR SHOWERS AND ISOLD TSTMS WILL SHIFT TO THE S COAST AND CAPE/ISLANDS THIS EVENING WHERE LOW RISK FOR BRIEF HEAVY RAIN. OTHERWISE EXPECT IMPROVING CONDITIONS WITH PARTIAL CLEARING OVERNIGHT AS DRIER AIR MOVES IN WITH WIND SHIFT TO WEST. SATURDAY... HIGH PRES BUILDS OVER OH VALLEY WITH DRY W/NW FLOW INTO NEW ENG. MID LEVEL SHORTWAVE AND COLD POOL MOVES INTO SNE WHICH WILL ACT ON LOW LEVEL MOISTURE LEADING TO SCT-BKN CU DEVELOPING...BUT DRY CONDITIONS. SEASONABLY MILD TEMPS IN THE MID/UPPER 50S...BUT GUSTY WEST WINDS EXPECTED WITH GUSTS TO 30-35 MPH. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... HIGHLIGHTS... * PLEASANT WEATHER AND SEASONABLE TEMPS THRU MIDWEEK * CHANCE OF RAIN SHOWERS SOMETIME MONDAY OR TUESDAY THE MODELS ARE IN EXCELLENT AGREEMENT THROUGH THE LONG TERM PORTION OF THE FORECAST. THERE ARE SOME DISCREPANCIES WITH THE TIMING OF A COLD FRONT MONDAY OR TUESDAY. THE ECMWF IS A BIT FASTER THAN THE GFS WITH THE FRONT...BRINGING IT THROUGH THE REGION MONDAY NIGHT. THE GFS BRINGS THE FRONT THROUGH ABOUT 12 HOURS LATER. THIS AFFECTS THE TIMING OF SHOWERS AS WELL AS THE AMOUNT OF INSTABILITY POTENTIALLY AVAILABLE FOR THUNDER. SATURDAY NIGHT AND SUNDAY...HIGH PRESSURE BUILDS IN BRINGING DRY WEATHER AND SEASONABLE TEMPERATURES. MONDAY AND TUESDAY...LOW PRESSURE MOVES ACROSS QUEBEC BRINGING A COLD FRONT THROUGH SOUTHERN NEW ENGLAND. AS STATED ABOVE...THERE IS SOME UNCERTAINTY ON THE TIMING OF THIS FRONT. THIS WILL LIKELY BRING A PERIOD OF RAIN SHOWERS TO THE REGION. TEMPERATURES WILL SOAR INTO THE 60S TO NEAR 70. WEDNESDAY AND THURSDAY...UPPER LEVEL RIDGE AND SURFACE HIGH PRESSURE BUILD OVER SOUTHERN NEW ENGLAND BRINGING DRY...SEASONABLE WEATHER TO THE REGION. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. .SHORT TERM /THROUGH FRIDAY NIGHT/... THROUGH TODAY...MODERATE CONFIDENCE. WIDESPREAD IFR/LIFR IN STRATUS AND PATCHY FOG WILL PERSIST FOR MUCH OF THE DAY...POSSIBLY IMPROVING TO MVFR THIS AFTERNOON AWAY FROM THE S COAST. RAIN EARLY THIS MORNING MOVES OUT BY DAYBREAK FOLLOWED BY A LULL IN PRECIP. SHOWERS REDEVELOP 18-21Z WEST AND 21-00Z EAST. LOW RISK OF ISOLATED THUNDER ALONG WITH HEAVY DOWNPOURS...MAINLY NEAR S COAST LATE AFTERNOON/EVENING. LLWS DEVELOPING AFT 21Z CAPE/ISLANDS AS LOW LEVEL JET DEVELOPS. TONIGHT...HIGH CONFIDENCE IN TRENDS. LOWER CONFIDENCE IN TIMING. MVFR/IFR IN THE EVENING...IMPROVING TO VFR 03-07Z AS WINDS SHIFT TO W. SHOWERS AND POSSIBLY AN ISOLD TSTM EXITS THE S COAST IN THE EVENING. SATURDAY...HIGH CONFIDENCE. VFR. W WIND GUSTS 25-30 KT DEVELOPING. KBOS TAF...MODERATE CONFIDENCE. IMPROVEMENT TO VFR TONIGHT BUT TIMING UNCERTAIN. KBDL TAF...MODERATE CONFIDENCE. IMPROVEMENT TO VFR TONIGHT BUT TIMING UNCERTAIN. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... SATURDAY NIGHT AND SUNDAY...HIGH CONFIDENCE. VFR. MONDAY AND TUESDAY...MODERATE CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF MVFR CONDITIONS IN SCT -SHRA SOMETIME LATE MONDAY INTO TUESDAY MORNING. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. .SHORT TERM /THROUGH SATURDAY/...HIGH CONFIDENCE. TODAY...INCREASING SW WINDS AHEAD OF COLD FRONT. A FEW G25 KT POSSIBLE BUT STRONG LOW LEVEL INVERSION WILL PREVENT STRONGER WINDS ALOFT FROM MIXING DOWN. AREAS OF FOG WILL REDUCE VSBYS. RAIN ENDS BY MID MORNING...THEN SHOWERS REDEVELOP TOWARD EVENING. TONIGHT...FRONTAL PASSAGE IN THE EVENING WITH SW WINDS BECOMING W. SPEEDS MOSTLY BELOW SCA BUT A FEW G25 KT POSSIBLE IN THE EVENING JUST AHEAD OF THE FRONT. SHOWERS AND AN ISOLD TSTM EXIT AFTER FROPA. VSBY IMPROVES WITH THE WIND SHIFT. SATURDAY...W/NW WIND GUSTS TO 25 KT...ESPECIALLY NE MA COASTAL WATERS. SCA WILL BE NEED TO BE EXTENDED. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... SATURDAY NIGHT THROUGH SUNDAY...HIGH CONFIDENCE. SEAS AND WINDS DIMINISH AS HIGH PRESSURE BUILDS OVER THE WATERS. WESTERLY WINDS SHIFT TO THE SOUTHWEST SUNDAY. MONDAY AND TUESDAY...MODERATE CONFIDENCE. SOUTHWESTERLY WINDS AND SEAS INCREASE IN ADVANCE OF A COLD FRONT CROSSING THE WATERS. THEN WINDS SHIFT TO THE WEST AND DIMINISH...ALONG WITH SEAS...AS HIGH PRESSURE BUILDS IN BEHIND THE FRONT. SMALL CRAFT ADVISORIES MAY BE NECESSARY FOR A PERIOD. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 6 AM EDT SATURDAY FOR ANZ235-237. SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ250-251- 254>256. && $$ SYNOPSIS...KJC/RLG NEAR TERM...KJC SHORT TERM...KJC LONG TERM...RLG AVIATION...KJC/RLG MARINE...KJC/RLG
AREA FORECAST DISCUSSION
NWS ALBANY NY
151 AM EDT FRI APR 10 2015 .SYNOPSIS... A WARM FRONT APPROACHES FROM THE SOUTH AND WEST TONIGHT WITH A PERIOD OF RAINFALL. THE WARM FRONT WILL MOVE NORTH OF MOST OF EASTERN NEW YORK AND WESTERN NEW ENGLAND TOMORROW...AS A MILDER AIR MASS BRIEFLY BUILDS IN. A COLD FRONT MOVES ACROSS THE REGION LATE TOMORROW AFTERNOON INTO THE EARLY EVENING WITH MORE SHOWERS AND ISOLATED THUNDERSTORMS. MAINLY DRY AND BRISK CONDITIONS OPEN THE WEEKEND WITH JUST A FEW SHOWERS NORTH AND WEST OF THE CAPITAL REGION. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1130 PM EDT...MESONET OBS AND KALY 00Z/10 SOUNDING CONTINUE TO INDICATE A SUBFREEZING LAYER MAINLY ABOVE 1200 FT AGL ACROSS THE BERKSHIRES AND SOUTHERN VT. STEADIER PRECIP IS QUICKLY APPROACHING FROM THE WEST. WE EXPECT A PERIOD OF FREEZING RAIN TO DEVELOP ACROSS THESE HIGHER ELEVATIONS ACROSS EASTERN BERKSHIRE CO...EASTERN BENNINGTON AND CENTRAL/WESTERN WINDHAM COS FOR SEVERAL HOURS OVERNIGHT. SOME ICE ACCRETIONS MAY REACH INTO THE 0.10-0.25 RANGE IN THESE HIGHER ELEVATIONS BEFORE TEMPS WARM TO ABOVE FREEZING CLOSER TO DAYBREAK. THEREFORE...A FREEZING RAIN ADVISORY HAS BEEN ISSUED FOR THE OVERNIGHT HOURS SPECIFICALLY FOR ELEVATIONS ABOVE 1200 FT IN THESE AREAS. OTHERWISE...WEAK MID-LEVEL RIDGING HAS NOW SHIFTED EASTWARD INTO NEW ENGLAND...AS A SHORT-WAVE IN THE WATER VAPOR LOOP CONTINUES TO APPROACH FROM THE MIDWEST AND EASTERN GREAT LAKES REGION. AT THE SFC...A WARM FRONT NOW EXTENDED INTO WESTERN PA....AND IS CONTINUING TO SLOWLY PUSH EAST-NORTHEAST. RADAR IMAGERY SHOWS A BATCH OF STEADY LIGHT RAIN MOVING FROM WEST TO EAST ACROSS THE REGION THANKS TO THE INITIAL PUSH OF WARM ADVECTION. THIS RAIN IS JUST NOW REACHING THE HUDSON VALLEY...AND WILL CONTINUE TO SPREAD EAST INTO NEW ENGLAND OVER THE NEXT FEW HOURS. OUTSIDE OF THE AFOREMENTIONED ADVISORY AREAS...TEMPS ARE HOLDING STEADY IN THE MID 30S TO LOW 40S. THESE LOOK TO BE THE LOW TEMPS FOR THE NIGHT...AS TEMPS WILL CONTINUE TO HOLD STEADY OR SLOWLY RISE THROUGH THE REMAINDER OF THE NIGHT. THE BETTER QG LIFT OR SYNOPTIC FORCING LOOKS LIKE IT WILL BE BETWEEN 06Z-12Z. BY LATE TONIGHT...A RUMBLE OR TWO OF THUNDER MAY OCCUR OVER W-CNTRL NY AND MAY GET CLOSE TO THE WRN PERIPHERY OF THE FCST AREA. THE NAM ACTUALLY BRINGS SHOWALTER VALUES DOWN TO 0 TO -2C BY 12Z. THE GFS IS MORE STABLE WITH THE LOWER SHOWALTER STABILITY INDICIES WEST OF THE FCST AREA. TOTAL RAINFALL AMOUNTS LOOK TO BE IN THE TWO TENTHS OF AN INCH TO HALF AN INCH RANGE WITH THE HIGHER TALLIES OVER THE SRN DACKS REGION. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/... TOMORROW...THE WARM FRONT MAKES STEADY PROGRESS ACROSS THE FCST AREA...WITH A MILDER AIR MASS BUILDING IN. SOME RAINFALL WILL LIKELY BE ONGOING THROUGH THE MORNING...AS THE S TO SW H850 LLJ OF 40-55 KTS MOVES ACROSS THE REGION. THE UPSTREAM UPPER LEVEL TROUGH TURNS NEGATIVELY TILTED OVER SE ONTARIO AND THE GREAT LAKES REGION WITH THE SFC CYCLONE MOVING TOWARDS SW QUEBEC. CLOUDS WILL BE PREVALENT TOMORROW...BUT THE LOW AND MID LEVEL WARMING WILL BE SIGNIFICANT WITH H850 TEMPS RISING INTO +9C TO +12C RANGE. SFC DEWPTS WILL RISE INTO THE U30S TO 40S ACROSS THE REGION AHEAD OF AN APPROACHING COLD FRONT. THERE IS A PRETTY GOOD POTENTIAL TEMP GRADIENT WITH THE BOUNDARY...BUT THE ONE LACKING INGREDIENT FOR ROBUST CONVECTION IS INSTABILITY. THE SHOWALTER VALUES ARE CLOSE TO 0C. SPC DOES HAVE THE ENTIRE AREA IN GENERAL THUNDER. WE WILL KEEP A SLIGHT CHC OF THUNDERSTORMS IN THE FCST AREA DURING THE AFTERNOON AND INTO THE EARLY EVENING DUE TO THE THERMAL GRADIENT AND LOW-LEVEL CONVERGENCE WITH THE FRONT. POPS WERE ALSO KEPT IN THE LIKELY CATEGORY DURING THE AFTERNOON. HIGHS ARE TRICKY BASED ON THE CLOUDS AND WE WENT CLOSE TO A BLEND OF THE GFS/NAM MOS GUIDANCE VALUES. THE GFSMOS VALUES WERE WARMER THAN THE COOLER METMOS NUMBERS. HIGHS IN THE WARM SECTOR COULD REACH THE U50S TO L60S SOUTH AND WEST OF THE CAPITAL REGION...AND MAINLY MID AND U50S TO THE NORTH AND EAST WITH A FEW U40S TO L50S IN THE SRN DACKS AREA. FRIDAY NIGHT...THE COLD FRONT MOVES EAST OF THE FCST AREA EARLY IN THE EVENING WITH FAIRLY STRONG COLD ADVECTION SETTLING IN. THE GFS HAS H850 TEMPS FALLING BACK TO -4C TO -6C FROM THE TRI CITIES NORTH AND WEST...AND -1C TO -4C SOUTH AND EAST. STRONG SUBSIDENCE IN THE WAKE OF THE FRONTAL PASSAGE MAY MAKE THE SKIES PARTLY CLOUDY. A FEW UPSLOPE SHOWERS WILL BE POSSIBLE FOR THE SRN DACKS REGION...AND SRN VT EARLY ON...AND THEY WILL TRANSITION TO SNOW SHOWERS WITH THE COLD ADVECTION KICKING IN. LOWS RANGE FROM THE U20S TO M30S OVER THE ADIRONDACK PARK AND SRN GREENS...AND U30S TO M40S SOUTH AND EAST WITH BRISK CONDITIONS. SATURDAY...CYCLONIC FLOW ALOFT IMPACTS THE FCST AREA WITH PIECES OF SHORT-WAVE ENERGY MOVING THROUGH. A SFC TROUGH EARLY IN THE DAY WILL FOCUS SOME ISOLD-SCT RAIN OR SNOW SHOWERS ESPECIALLY NORTHWEST OF THE CAPITAL REGION. DOWNSLOPING EFFECTS MAY OFFSET THE COOL CYCLONIC FLOW WITH HIGHS IN THE 50S IN THE VALLEYS...POSSIBLY A FEW L60S IN THE MID HID HUDSON VALLEY...AND 40S OVER THE MTNS. THE H850 WINDS WILL BE IN THE 30-40 KTS...AND AS THE PREVIOUS DISCUSSION MENTIONED SOME OF THE BUFKIT MOMENTUM TRANSFER PROFILES HINT AT GOOD MIXING WITH A FEW GUSTS AROUND 35 KTS OR SO. EXPECT W TO NW WINDS OF 10-25 MPH WITH SOME GUSTS IN THE 30 TO 40 MPH RANGE. SATURDAY NIGHT...A WEAKENING SFC PRESSURE GRADIENT,,,AND SFC HIGH PRESSURE RIDGING IN FROM THE OH VALLEY AND THE MID ATLANTIC STATES WILL ALLOW FOR CLEARING SKIES...LIGHT WINDS AND COLD CONDITIONS WITH LOWS IN THE 20S TO L30S. && .LONG TERM /SUNDAY THROUGH THURSDAY/... THE PERIODS STARTS OUT ON SUNDAY WITH HIGH PRESSURE CENTERED OVER THE MID ATLANTIC STATES AND RIDGING EXTENDING NORTHWARD INTO OUR REGION. THIS WILL PROVIDE FOR DRY...SUNNY AND RELATIVELY WARM WEATHER WITH LIGHT WINDS TOO MAKING FOR A PLEASANT SPRING DAY. TEMPERATURES SHOULD REACH THE LOWER 60S IN MOST VALLEY LOCATIONS. THE HIGH IS FORECAST TO SHIFT EASTWARD OFF THE EAST COAST SUNDAY NIGHT...AS AN UPPER LEVEL TROUGH AND ASSOCIATED SURFACE COLD FRONT ADVANCE EASTWARD ACROSS THE UPPER GREAT LAKES. DRY CONDITIONS SHOULD PREVAIL THROUGH SUNDAY NIGHT. THE NEXT CHANCE OF SHOWERS ARRIVES ON MONDAY INTO MONDAY EVENING... AS THE COLD FRONT AND UPPER TROUGH CROSS THE AREA. THIS SYSTEM WILL HAVE FAIRLY LIMITED MOISTURE TO WORK WITH AND NORTHERN STREAM ENERGY...SO WILL ONLY MENTION SCATTERED SHOWERS FOR NOW. AHEAD OF THE FRONT TEMPERATURES SHOULD WARM WELL INTO THE 60S WITH A SOUTHERLY FLOW DEVELOPING AND SOME SUNSHINE ESPECIALLY DURING THE FIRST HALF OF THE DAY. A FEW SHOWERS MAY LINGER INTO MONDAY EVENING ACROSS THE SOUTHEAST HALF OF THE AREA...OTHERWISE DRYING CONDITIONS WILL OCCUR LATE MONDAY NIGHT INTO EARLY TUESDAY MORNING. DRY NORTHWEST FLOW WILL BE IN PLACE FOR TUESDAY...PROVIDING SEASONABLE TEMPERATURES AND BREEZE NORTHWEST WINDS. OTHERWISE...HIGH PRESSURE LOOKS TO BUILD BACK IN ACROSS THE REGION ON WEDNESDAY AND POSSIBLY LASTING INTO THURSDAY BASED ON THE LATEST GUIDANCE. WILL TAKE OUT ANY MENTION OF POPS DURING THIS TIME WITH DRY CONDITIONS NOW EXPECTED. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... COMBINATION OF MVFR/IFR FLIGHT CONDITIONS THE REMAINDER OF THE OVERNIGHT AS WARM FRONT SLOWLY LIFTS NORTHWARD WITH OCCASIONAL SHOWERS/PERIODS OF RAIN. AS MENTIONED IN THE PREVIOUS EXCELLENT DISCUSSION...LLWS WILL BECOME AN ISSUE AS EVIDENT IN THE LATEST VWP FROM THE RADAR AND HAVE CONTINUED THE MENTION IN THE LATEST FORECASTS OVERNIGHT. DURING THE DAYLIGHT HOURS FRIDAY...PER THE HRRR AND 4KM SPC WRF REFLECTIVITY FORECASTS...SEEMS THERE WILL BE A REDUCTION IN PRECIP COVERAGE AS WARM FRONT LIFTS NORTHWARD. LATER IN THE DAY...COLD FRONT WILL APPROACH WITH A CHC-SCT CONVECTION ALONG THE BOUNDARY. FOR NOW...WE WILL PLACE A PROB30 AND MONITOR TRENDS. FLIGHT CONDITIONS SHOULD IMPROVE TO AT LEAST MVFR THROUGH THE DAY. FRIDAY EVENING WITH FROPA...WINDS WILL QUICKLY SHIFT FROM THE WESTERLY DIRECTION WITH FLIGHT CONDITIONS IMPROVING TO VFR. THE EXCEPTION TO THIS WOULD BE INTO KPSF WHERE UPSLOPE CONDITIONS MAY LINGER MVFR CIGS A BIT LONGER. OUTLOOK... FRIDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY NO SIG WX. SATURDAY: MODERATE OPERATIONAL IMPACT. WINDY WITH GUSTS TO 30.0 NO SIG WX. SATURDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY NO SIG WX. SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS ANTICIPATED THROUGH THE REST OF THE WORK WEEK DUE TO EXPECTED WET AND UNSETTLED CONDITIONS AND MAINLY COOL WEATHER. A WARM FRONT APPROACHES FROM THE SOUTH AND WEST TONIGHT WITH A PERIOD OF RAINFALL. THE WARM FRONT WILL MOVE NORTH OF MOST OF EASTERN NEW YORK AND WESTERN NEW ENGLAND TOMORROW...AS A MILDER AIR MASS BRIEFLY BUILDS IN. A COLD FRONT MOVES ACROSS THE REGION LATE TOMORROW AFTERNOON INTO THE EARLY EVENING WITH MORE SHOWERS AND ISOLATED THUNDERSTORMS. MAINLY DRY AND BRISK CONDITIONS OPEN THE WEEKEND WITH JUST A FEW SHOWERS NORTH AND WEST OF THE CAPITAL REGION. DRY WEATHER IS EXPECTED TO CLOSE THE WEEKEND. && .HYDROLOGY... A WARM FRONT IS EXPECTED TO LIFT BACK NORTH TONIGHT INTO TOMORROW...RESULTING IN A WARMUP WITH A CONTINUED THREAT FOR RAIN AND EVEN A SLIGHT CHANCE OF THUNDERSTORMS ON FRIDAY. SNOW MELT IS LIKELY WITH THE QUARTER TO HALF AN INCH RAINFALL TONIGHT. ANOTHER TENTH TO QUARTER INCH OF RAINFALL IS POSSIBLE TOMORROW AHEAD OF THE COLD FRONT. THE LATEST MMEFS /ENSEMBLE GUIDANCE/ INDICATES RIVER LEVELS WILL RISE BY EARLY IN THE WEEKEND...WITH SEVERAL POINTS POTENTIALLY APPROACHING ACTION STAGE. THE ONLY POINT THAT MAY REACH MINOR FLOOD STAGE IS GILBOA. WE WILL CONTINUE TO WATCH THE POTENTIAL FOR RIVER RISES OVER THE NEXT DAY OR TWO. WIDESPREAD FLOODING IS NOT EXPECTED AT THIS TIME...BUT SIGNIFICANT WITHIN BANK RISES ARE POSSIBLE. TOTAL QPF TONIGHT THROUGH FRIDAY WILL BE IN THE THIRD OF AN INCH TO THREE QUARTERS OF AN INCH RANGE WITH THE HIGHER AMOUNTS OVER THE SRN DACKS REGION. COOLER AND DRIER WEATHER RETURNS ON SATURDAY. THE DRY WEATHER MAY EXTEND INTO EARLY NEXT WEEK ALLOWING FLOWS TO RECEDE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...FREEZING RAIN ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR MAZ001-025. VT...FREEZING RAIN ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR VTZ013>015. && $$ SYNOPSIS...WASULA NEAR TERM...FRUGIS/KL/WASULA SHORT TERM...WASULA LONG TERM...JPV AVIATION...FRUGIS/BGM FIRE WEATHER...BGM/WASULA HYDROLOGY...BGM/WASULA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
359 AM CDT FRI APR 10 2015 .SHORT TERM... 323 AM CDT THROUGH SATURDAY... BEYOND THE STRONG WINDS TODAY...A QUIET PERIOD IS IN STORE AFTER A BUSY THURSDAY. THE LOW PRESSURE SYSTEM AND FRONTAL ZONE THAT SUPPORTED THURSDAYS STORMS ARE LIFTING OUT OF THE GREAT LAKES AHEAD OF A SFC HIGH APPROACHING FROM THE SOUTHERN PLAINS. THE UPPER TROUGH IS OF COURSE TRAILING THE SFC LOW AND STILL CONTAINS SOME DECENT SHORTWAVES AS SEEN UPSTREAM FROM THE LOCAL AREA...BOTH IN SATELLITE IMAGERY AND IN THE AREAS OF LIGHT PRECIP ACROSS WI. EVEN SOUTH INTO ILLINOIS...SOME POCKETS OF LIGHT RAIN OR DRIZZLE ON THE RADAR EARLY THIS MORNING MAY PERSIST AT TIMES THROUGHOUT THE DAY AS STRONGER SHORTWAVES IN THE UPPER TROUGH ADVECT OVERHEAD...BUT LITTLE IF ANY MEASURABLE PRECIP IS EXPECTED TODAY. THE CENTER OF THE HIGH MOVES OVERHEAD TONIGHT...CLEARING OUT ANY CLOUDS THAT DO FORM TODAY AND DROPPING WINDS ENOUGH TO SUPPORT RADIATIONAL COOLING AND THE LOWEST LOWS EXPECTED OVER THE NEXT WEEK. THE DAYTIME SATURDAY PERIOD ALSO WILL BE DOMINATED BY THE SFC HIGH BUT THIS TIME WITH RIDGING ALOFT. LOCATIONS NEAR THE LAKE LIKELY WILL SEE AFTERNOON COOLING AS THE LAKE BREEZE DEVELOPS...BUT IN GENERAL SATURDAY IS LOOKING PRETTY GOOD FOR THOSE WHO ENJOY SUNNY AND MILD SPRING DAYS. LENNING && .LONG TERM... 323 AM CDT SATURDAY NIGHT THROUGH THURSDAY... COOLER BUT GENERALLY MILD TEMPERATURES IN THE 60S WILL PERSIST INTO THE LATE WEEKEND AND NEXT WEEK. BY SATURDAY NIGHT THE SFC RIDGE THAT KEEPS THINGS QUIET TODAY AND SATURDAY WILL HAVE MOVED INTO THE OHIO VALLEY AND ALLOWED GULF RETURN FLOW TO START DEVELOPING. THE EFFECTS OF THIS BECOME MUCH MORE PRONOUNCED BY SUNDAY NIGHT...BUT PRECIP CHANCES WILL START A GRADUAL INCREASE BEGINNING DURING THE DAYTIME PERIOD SUNDAY. BY SUNDAY NIGHT INTO MONDAY MORNING THE INCREASED GULF MOISTURE AND AN APPROACHING COLD FRONT WILL SUPPORT LIKELY PRECIP AND CHANCES OF THUNDERSTORMS...BUT THIS APPEARS TO BE SHORT LIVED AS THE FRONT MOVES QUICKLY THROUGH THE AREA AND EXITS BY MONDAY AFTERNOON. TUESDAY AND WEDNESDAY REPEAT THE PATTERN WITH HIGH PRESSURE SUPPRESSING ACTIVITY TUESDAY AND GRADUALLY MOVING EAST TO ALLOW RETURN FLOW BY WEDNESDAY. RIGHT NOW THE CHANCE POPS FOR WEDNESDAY LOOK OVERDONE...BUT WILL ELECT TO WAIT FOR MORE INFORMATION BEFORE MAKING ANY CHANGES. THE MORE PRONOUNCED RETURN FLOW BECOMES ESTABLISHED BY NEXT THURSDAY AHEAD OF THE NEXT APPROACHING COLD FRONT...AT LEAST ACCORDING TO THE DETERMINISTIC GFS AND ECMWF. LENNING && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * MVFR CIGS OVERNIGHT. * GUSTY WINDS BCMG SW TO W ARND MIDNIGHT WITH MAX GUSTS AROUND 40 KT. SUSTAINED WINDS OF 25-27 KT LATE THIS EVENING AND OVERNIGHT. GUSTY W WINDS THROUGH THE DAY FRIDAY. KMD //DISCUSSION...UPDATED 06Z... MAIN NEAR TERM CONCERN IS GUSTY SW WINDS. EXPECT A PERIOD OF SUSTAINED WINDS 25-30 KT AND GUSTS TO 40 KT OR SO THROUGH THE EARLY MORNING HOURS...DIMINISHING SOME BUT REMAINING GUSTY OUT OF THE WEST FRIDAY. EXPECT MVFR CIGS LOWERING LATE TONIGHT BUT LARGELY REMAINING ABOVE IFR...THEN LIFTING IS EXPECTED FRIDAY MORNING BUT CONTINUED GUSTY WINDS. A FEW SHOWERS ARE POSSIBLE FRIDAY AFTERNOON...BUT CONFIDENCE IS LOW AND HAVE THUS MAINTAINED ONLY A VCSH AT KRFD. KMD //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN MVFR CIGS TONIGHT...MEDIUM ON SPECIFIC HEIGHTS. * MEDIUM/HIGH CONFIDENCE IN WIND GUSTS OVERNIGHT AND TOMORROW...THOUGH LOWER/MEDIUM CONFIDENCE ON SPECIFIC SPEEDS ON FRIDAY. KMD //OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z... 00Z... * SATURDAY...DRY/VFR. SOUTHWEST WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...DRY/VFR. GUSTY SOUTH WINDS. * MONDAY...DRY/VFR. EAST WINDS. * TUESDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS. * WEDNESDAY...CHANCE OF SHRA. SOUTH WINDS. && .MARINE... 323 AM CDT STRONG AND GUSTY WEST GALES IN THE WAKE OF THE COLD FRONT THAT MOVED ACROSS THE LAKE LATE ON THURSDAY WILL GRADUALLY DIMINISH AND TURN NORTHWESTERLY THIS AFTERNOON BEFORE FLIPPING BACK TO THE SOUTHWEST TONIGHT AND SATURDAY. THIS GENERALLY SOUTHERN FLOW PERSISTS UNTIL SUNDAY NIGHT WHEN THE NEXT APPROACHING COLD FRONT MOVES ACROSS THE LAKE AND TURNS THINGS NORTHWEST AGAIN. THIS WEST TO NORTHWEST TO SOUTH PATTERN REPEATS ITSELF MONDAY THROUGH WEDNESDAY BEFORE THE NEXT COLD FRONT APPROACHES ON THURSDAY. OVERALL MOSTLY QUIET WEATHER IS EXPECTED THROUGH THE PERIOD...THOUGH THE FRONT ON SUNDAY NIGHT COULD SUPPORT SHOWERS AND THUNDERSTORMS. LENNING && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011- ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023- ILZ032-ILZ033-ILZ039 UNTIL 4 AM FRIDAY. IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 4 AM FRIDAY. LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777- LMZ779 UNTIL 1 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 305 AM CDT Fri Apr 10 2015 .SHORT TERM...(Today) ISSUED AT 304 AM CDT FRI APR 10 2015 Much cooler and less humid conditions are expected across central and southeast Illinois today in the wake of Thursday evening`s cold front. While high temperatures should average at least 15 degrees cooler than yesterday, they will still be near normal levels for early April. Breezy westerly winds will persist for much of the day, with a gradual decrease in speed toward evening as high pressure begins to build into the area. && .LONG TERM...(Tonight through Thursday) ISSUED AT 304 AM CDT FRI APR 10 2015 Quiet start to the weekend on tap as high pressure drifts through the Midwest. After that, focus shifts to a shortwave traveling along the U.S./Canadian border. Some timing differences amongst the evening models on the speed of this system, with the ECMWF and Canadian models lagging several hours behind the U.S. counterparts. However, enough agreement exists to bump up PoP`s to around 60% Sunday night in many areas. The discrepancies widen on Monday, as a small closed low traverses the southwest U.S. border and emerges into northwest Texas. The progress of our cold front will be slowed as low pressure develops along the tail end of the front over the southern Plains, with only the GFS progressive enough to get the any lingering rain out of the CWA before Monday afternoon. Thus, have lingered rain chances across the southeast third of the CWA into much of Monday. Have dropped rain chances for Tuesday, as upper ridging drifts through the central U.S., and scaled back quite a bit for Tuesday night as well, although this may not be far enough. Some moisture return on Wednesday may be enough for some light showers, as the remnants of the Texas closed low nudge toward the mid-Mississippi Valley. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) ISSUED AT 1235 AM CDT FRI APR 10 2015 Gusty westerly winds will persist across the central Illinois terminals through 00z Saturday in the wake of the cold front that passed through the area Thursday evening. A period of wrap around MVFR cigs are expected over the next few hours behind the cold front, but VFR conditions are expected otherwise. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Bak LONG TERM...Geelhart AVIATION...Bak
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1235 AM CDT Fri Apr 10 2015 .UPDATE... ISSUED AT 854 PM CDT THU APR 9 2015 Vigorous shortwave and jet streak are pushing a cold front rapidly across IL. They have triggered strong to severe storms with isolated tornadoes this afternoon/evening. Remaining storms seem to be evolving into more outflow dominated storms, but will continue to monitor for any localized rotations the next couple hours. Storms and cold front are projected to be east of our IL counties by 11 pm, with strong west-southwest winds in their wake. Sustained winds behind the front will increase to 20 mph and gust to 35 mph at times. A brief period of clearing skies may follow the front for an hour or so, but low clouds will return for 6-8 hours the rest of the night. Clear skies will return from west to east around sunrise tomorrow, with gusty winds continuing. Low temps will drop about 20 degrees colder than last night, with readings in the mid to upper 40s toward sunrise. Likewise, highs on Friday will be around 15-18F colder than today, but still in the low 60s. Updated the weather and PoP forecasts to match expected trends, with minor adjustments to clouds cover timing. Updated info will be available by 9 pm. && .SHORT TERM...(Tonight) ISSUED AT 307 PM CDT THU APR 9 2015 19z/2pm surface analysis shows 998mb low centered over southeast Iowa, with cold front trailing southward into western Missouri. Line of convection is rapidly developing along the front within the moderately unstable and uncapped airmass in the warm sector. 0-6km bulk shear values will be on the increase as the afternoon progresses as a mid-level short-wave approaches from the west, resulting in continued convective intensification. HRRR has had a good handle on the situation throughout the day, with its latest iteration agreeing closely with prior runs. Based on satellite timing tools and HRRR guidance, it appears the line of storms will cross the Mississippi River by 23z/6pm, then will track through the Illinois River Valley and to the I-55 corridor by about 02z/8pm. Damaging wind gusts will be the primary threat, but large hail and a few tornadoes will be possible as well. As the storms move further east, they will likely congeal into a solid line and the tornado threat will diminish accordingly. Once the front passes, windy and cooler weather will be on tap overnight with a slow west to east clearing trend by dawn. && .LONG TERM...(Friday through Thursday) ISSUED AT 307 PM CDT THU APR 9 2015 Morning upper air shows a potential severe event this afternoon and evening, as main upper level shortwave and vort max over southwest NE at 12z will be rotating to the east. Low level thermal ridge and moisture axis extends into MO/IL ahead of the approaching front. low level jet is particularly strong flowing into MO/western IL and so ample shear available in warm sector. HRRR model and NAM a little slower on the movement of the front through the region, going through this evening. Shear with strong upper jet and low level southern jet will make severe potential with severe storms possible on the cold front as it sweeps through. Deepening surface low to move northeast into eastern IA and then southern WI. High pressure in control until weak front moves in and brings showers on late Sunday and Sunday night. Another chance off showers Tuesday into Thursday. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) ISSUED AT 1235 AM CDT FRI APR 10 2015 Gusty westerly winds will persist across the central Illinois terminals through 00z Saturday in the wake of the cold front that passed through the area Thursday evening. A period of wrap around MVFR cigs are expected over the next few hours behind the cold front, but VFR conditions are expected otherwise. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Shimon SHORT TERM...Barnes LONG TERM...Goetsch AVIATION...Bak
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
136 AM EDT FRI APR 10 2015 .SYNOPSIS... ISSUED AT 136 AM EDT FRI APR 10 2015 DRY AND WINDY CONDITIONS ARE EXPECTED TODAY BEHIND A STRONG COLD FRONT. HIGH PRESSURE WILL BUILD IN LATER TONIGHT INTO SATURDAY PROVIDING LIGHTER WINDS AND MAINLY CLEAR SKIES. TEMPERATURES TODAY INTO SATURDAY WILL BE COOLER WITH HIGHS GENERALLY IN THE 50S AND LOWS IN THE 30S. && .UPDATE... ISSUED AT 815 PM EDT THU APR 9 2015 18Z RAOB OUT OF KILX INDICATES CURRENT CONV PROB ATTM W/CAPPING INVERSION ARND H85 AND NO DOUBT EXACERBATED BY SUBSIDENCE ASSOCD/W SW TROUGH OVERHEAD. EXTENT/DURATION OF POPS THIS EVENING AHD OF STG CDFNT SWEEPING EWD OUT OF WRN IL PROBLEMATIC IN LIGHT OF LIMITED UPSTREAM DVLPMNT SO FAR AND LACK OF LARGER SCALE ORGANIZATION. LATEST NR TERM AND 18Z GUIDANCE TEPID AT BEST AND SUGGESTIVE OF TEMPERING PRIOR CAT MENTION. REGARDLESS COOLING ALOFT SPREAD EWD OVERTOP FNTL ZONE IN TANDEM W/RAMPING LLJ SHLD PREDICATE MORE ERSTWHILE DVLPMNT THOUGH MID EVENING AS CONVN SLIDES EWD INTO WRN ZONES. && .SHORT TERM...(THIS EVENING AND TONIGHT) ISSUED AT 324 PM EDT THU APR 9 2015 MULTIPLE CONVECTIVELY-ENHANCED SHORTWAVES CONTINUE TO RIPPLE THROUGH THE REGION IN SOUTHWEST FLOW AHEAD OF MAIN TROUGH AXIS STILL WELL TO OUR WEST. THIS HAS LED TO A MUDDLED MESOSCALE ENVIRONMENT WITH MULTIPLE ROUNDS OF WEAK/ELEVATED CONVECTION SO FAR TODAY. DIURNAL DESTABILIZATION HAS BEEN SLOW GIVEN ABUNDANT RAIN AND STRATUS. STARTED TO SEE SOME BREAKS IN THE CLOUDS DURING THE LAST COUPLE HOURS BUT STILL A LOT OF CONVECTIVE DEBRIS TO INHIBIT SURFACE DIABATIC HEATING. LATEST RAP/SPC MESOANALYSIS SHOWS BETTER SURFACE BASED INSTABILITY JUST NOW STARTING TO NOSE INTO OUR SOUTHWESTERN CWA AS WARM FRONT IS PUSHED NORTHWARD BY STRENGTHENING LOW LEVEL GRADIENT AHEAD OF APPROACHING LOW BUT RAP SOUNDINGS STILL SHOW A SUBTLE 700-800MB INVERSION OVER MUCH OF OUR AREA THROUGH THE LATE AFTERNOON. TWO FEATURES TO WATCH FOR SEVERE WEATHER THREAT THIS EVENING...ONE IS A SUBTLE PREFRONTAL TROUGH CURRENTLY PUSHING THROUGH NORTH-CENTRAL ILLINOIS AND SECOND IS THE ACTUAL COLD FRONT ITSELF...STILL IN CENTRAL MISSOURI. FORCING IS WEAK WITH THE FIRST WAVE BUT APPEARS TO BE ENOUGH SURFACE HEATING TO GENERATE AROUND 1000 J/KG OF MLCAPE OVER ILLINOIS. THERE IS HOWEVER A LOCAL MINIMUM OF INSTABILITY SEEN ON RAP/SPC MESOANALYSIS OVER WESTERN INDIANA. RAP SUGGESTS INSTABILITY IN THIS AREA WILL FILL IN OVER THE NEXT FEW HOURS AND IF THE CLUSTER OF STORMS OVER CENTRAL ILLINOIS CAN LATCH ONTO THAT...IT WILL BE CAPABLE OF PRODUCING SEVERE WEATHER IN OUR AREA LATER THIS AFTERNOON. CONFIDENCE IN THIS HAPPENING IS LOW THOUGH...GIVEN NORTHWARD DISPLACEMENT OF STORMS CURRENTLY ON RADAR AND RELATIVELY DIFFUSE FORCING. STORMS MAY CLIP OUR NORTHWEST COUNTIES BUT DIFFICULT TO SAY HOW MUCH INSTABILITY WILL BE LEFT BY THAT POINT. SPC HAS ISSUED A TORNADO WATCH RIGHT UP TO OUR WESTERN BORDER. WILL CONTINUE TO MONITOR CLUSTER OF STORMS UPSTREAM DURING THE NEXT FEW HOURS TO SEE IF A LOCAL EXTENSION MAY BE NECESSARY BUT FOR NOW THREAT APPEARS LOW. POTENTIAL THREAT WITH THIS FEATURE WILL FALL IN THE 22-00Z TIMEFRAME WITH THE MAIN HAZARD BEING DAMAGING WINDS. SECOND FEATURE TO WATCH IS THE ACTUAL COLD FRONT. THIS FEATURE WILL NOT ARRIVE UNTIL 03-04Z TONIGHT AND BY THEN WE LOSE ANY SURFACE BASED INSTABILITY. MIDLEVEL LAPSE RATES ARE MODEST...AROUND 7 C/KM...BUT NOT QUITE HIGH ENOUGH TO SUPPORT A WIDESPREAD SEVERE WEATHER THREAT. SOME DAMAGING WINDS ARE CERTAINLY POSSIBLE GIVEN VERY STRONG LLJ WITH 850MB WINDS OVER 50 KTS BUT WILL BE CONTINGENT UPON GETTING A SUSTAINED UPDRAFT AND ADEQUATE PRECIP LOADING. THAT IS QUESTIONABLE AT THIS POINT. THREAT IS CERTAINLY THERE BUT IS CONDITIONAL ON HOW MUCH INSTABILITY IS LEFT BY THE TIME IT REACHES US. WILL CONTINUE TO MONITOR UPSTREAM TRENDS CLOSELY THROUGH THE LATE AFTERNOON AND EVENING TO UPDATE THE FORECAST AS NECESSARY. UPDATED GRIDS/ZFP WILL BE OUT SHORTLY. && .LONG TERM...(FRIDAY THROUGH THURSDAY) ISSUED AT 324 PM EDT THU APR 9 2015 PRIMARY FOCUS FOR THE LONG TERM WILL BE HIGH WINDS ON FRIDAY... THE SFC LOW PRESSURE SYSTEM RESPONSIBLE FOR THE ACTIVE WEATHER TODAY WILL HAVE MADE ITS WAY INTO EASTERN UPPER MICHIGAN BY FRIDAY MORNING. THIS PUTS THE CWA LARGELY IN THE DRY SLOT AND IN THE REGION OF CAA. ALOFT...A CLOSED 500MB LOW LIFTS FROM UPPER MICHIGAN FRIDAY MORNING TO JUST SOUTH OF JAMES BAY BY FRIDAY NIGHT. WITH A STRONG RIDGE ANCHORED OVER THE ATLANTIC/NEW ENGLAND STATES...A 100 KT 500MB JET DEVELOPS OVER THE CWA AND REMAINS THROUGH AT LEAST THE EARLY AFTERNOON. LOOKING AT MODEL SOUNDINGS...IT APPEARS WE WILL BE MIXING TO NEAR 900MB EARLIER IN THE DAY...THEN UP AS HIGH AS 700-750MB BY MID AFTERNOON. THINKING GUSTS WILL BE HIGHEST IN THE EARLY AFTERNOON THEN TAPER OFF WEST TO EAST AS THE UPPER LEVEL WIND MAXIMUM AND SFC PRESSURE RISE/FALL COUPLET MOVES NORTHEASTWARD. THINKING GUSTS TO 35-45 MPH ARE LIKELY GIVEN MIXING POTENTIAL TOMORROW...BUT WILL HOLD OFF ON ISSUING ANY WIND ADVISORIES FOR NOW...AS WE ARE RIGHT BELOW CRITERIA AND DO NOT WANT TO DETRACT PUBLIC ATTENTION AWAY FROM THE THREAT OF SEVERE WEATHER THIS EVENING/OVERNIGHT. KEPT THE GOING HEADLINE FOR THE GALE WARNING UNTIL 15Z...AS CONDITIONS ARE MORE STABLE OVER THE LAKE. OTHERWISE...SHORTWAVE/PV ANOMALY ROTATING AROUND THE EXITING LOW PRESSURE MAY BRING ADDITIONAL LL MOISTURE FORCING FOR RAIN SHOWERS FRIDAY AFTERNOON/EVENING...MAINLY IN THE NORTHERN PORTIONS OF OUR CWA. MODELS WERE IN GREAT DISAGREEMENT AS TO THE STRENGTH OF THE WAVE...SO FOR NOW KEPT JUST SLIGHT CHANCE POPS/RAIN SHOWERS FOR NOW. HIGHS WILL RANGE FROM THE MID-UPPER 50S TO LOW 60S. SATURDAY INTO SUNDAY AFTERNOON WILL BE RELATIVELY QUIET...WITH HIGH PRESSURE SETTLING IN OVERHEAD. HIGH TEMPERATURES WILL BE COOL...WITH HIGHS AGAIN STRUGGLING TO REACH ABOVE THE LOW 60S. FOR THE EXTENDED PERIOD...500MB FLOW IS SOMEWHAT SPLIT BY SUNDAY NIGHT...WITH A DEEPENING TROUGH MOVING ACROSS NORTHERN ONTARIO AND UPPER MI/NORTHERN LOWER MI THROUGH MONDAY NIGHT...THEN A DEVELOPING CLOSED LOW IN THE SOUTHWESTERN U.S. TAKES SHAPE MONDAY NIGHT INTO TUE AS A RIDGE BUILDS OVER OUR CWA AND THE SOUTHEASTERN STATES. THE LOW DEEPENS AND MOVES NORTHEASTWARD TUE NIGHT INTO THE NORTH-CENTRAL PLAINS BEFORE PHASING INTO THE NORTHERN BRANCH WED. FOR OUR CWA...MODELS ARE IN GENERAL AGREEMENT WITH RESPECT TO THE COLD FRONT ASSOCIATED WITH THE NORTHERN STREAM SYSTEM IN ONTARIO/UPPER MI. BOTH THE ECMWF/GFS BRING THE FRONT ACROSS OUR AREA SUNDAY NIGHT INTO MONDAY...THOUGH THEY DIFFER WITH RESPECT TO EXACT TIMING AND STRENGTH. AS USUAL...THE GFS IS FASTER AND SLIGHTLY DEEPER WITH THE UPPER LEVEL TROUGH MOVING THROUGH...AND THUS THE FRONT IS MORE ORGANIZED. THE ECMWF SHOWS A WEAKER UL TROUGH AND CORRESPONDING SFC SYSTEM/COLD FRONT. KEPT CONSENSUS POPS FOR NOW...WHICH DID A DECENT JOB SHOWING THE OVERALL TREND. TUESDAY LOOKS TO REMAIN LARGELY QUIET...WITH SMALL RIDGE BUILDING OVER THE AREA FOR THE FIRST PART OF THE DAY. SLIGHT CHANCE FOR RAIN SHOWERS BY LATE AFTERNOON WITH NEXT APPROACHING SYSTEM. OF COURSE...THE PHASING SYSTEMS/STREAMS ARE A COMPLETE MESS IN THE MODEL WORLD...WITH A WHOLE HOST OF SOLUTIONS THAT COULD PLAY OUT TUESDAY NIGHT INTO THURSDAY. JUST KEPT THE CONSENSUS POPS AND OUR FORECASTED THUNDER AS THERE IS TOO MUCH DISAGREEMENT TO MAKE ANY REAL IMPROVEMENTS. GOOD NEWS IS...TEMPS WARM INTO THE UPPER 60S AND LOW 70S FOR MUCH OF THIS TIME PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 136 AM EDT FRI APR 10 2015 STRONG POST FRONTAL LOW LEVEL COLD ADVECTION/PRESSURE RISES WILL SUPPORT A RATHER WINDY DAY AT THE TERMINALS. RETAINED VTCS WITH THE FRONTAL PASSAGE THROUGH 07Z AT KSBN AND 08-09Z AT KFWA. DRY/MAINLY VFR OTHERWISE OUTSIDE OF A PERIOD OF HIGH MVFR STRATOCU THIS MORNING/EARLY AFTERNOON. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...GALE WARNING UNTIL 11 AM EDT THIS MORNING FOR LMZ043-046. && $$ UPDATE...T SYNOPSIS...MURPHY SHORT TERM...AGD LONG TERM...MCD AVIATION...STEINWEDEL VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
206 AM EDT FRI APR 10 2015 .UPDATE... ISSUED AT 205 AM EDT FRI APR 10 2015 FINE TUNED THE POPS AND TEMPERATURES ACCORDING TO THE LATEST TRENDS IN RADAR AND OBSERVATIONS. OVERALL...THERE IS A SLOWER TREND TO THE WIDEPREAD CONVECTION. CLOUD TOPS HAVE BEEN GENERALLY WARMING OFF TO THE WEST...HOWEVER A STRONG 850 MB JET OF 50 TO 55 KTS WILL CONTINUE TO REMAIN IN PLACE THROUGH DAWN...SO WILL HAVE TO WATCH FOR STRONGER WIND GUSTS WITHIN EVEN MODERATE TO STRONG STORMS. UPDATE ISSUED AT 1033 PM EDT THU APR 9 2015 JUST SENT OUT ONE LAST UPDATE TO THE FORECAST FOR THIS EVENING. UPSTREAM RADAR IMAGERY SHOWING THE NEAREST THUNDERSTORMS TO OUR AREA CURRENTLY MOVING INTO FAR WESTERN KENTUCKY AND SOUTHWESTERN INDIANA. BASED ON THE SOUTHWEST TO NORTHEAST MOVEMENT OF THE INDIVIDUAL STORMS...AND THE EASTWARD MOVEMENT OF THE LINE AS THE WHOLE...IT APPEARS THAT IT MAY BE EVEN LATER BEFORE WE SEE THE FIRST STORMS MOVING INTO OUR WESTERN COUNTIES OVERNIGHT. AS IT STANDS...PRECIP ONSET IS FORECAST TO OCCUR BETWEEN 6 AND 7Z IN OUR FAR NORTHWEST AND WESTERN COUNTIES...WITH THE LINE OF SHOWERS AND STORMS MOVING THROUGH THE CENTRAL AND EASTERN PORTIONS OF THE FORECAST AREA BETWEEN 9 AND 16Z ON FRIDAY. DAMAGING WINDS GUSTS...LARGE HAIL...AND LOCALLY HEAVY RAINFALL AND POSSIBLY FLASH FLOODING WILL REMAIN THREATS WITH THE LINE OF STORMS AS THEY TRACK EASTWARD ACROSS THE AREA. A NEW SET OF ZONES HAS ALREADY BEEN ISSUED BASED ON THE AFOREMENTIONED GRID UPDATES. UPDATE ISSUED AT 813 PM EDT THU APR 9 2015 ANOTHER UPDATE TO THE FORECAST GRIDS AND THE ZONE FORECAST TEXT PRODUCT WERE NECESSARY THIS EVENING. BASED ON CURRENT SATELLITE AND RADAR TRENDS...IT APPEARS THAT PRECIPITATION ONSET ACROSS THE AREA WILL OCCUR A FEW HOURS LATER THAN PREVIOUSLY FORECAST. OVER THE PAST HOUR OR SO THERE HAVE BEEN NO SHOWERS OR STORMS PRESENT ACROSS MOST OF CENTRAL AND ALL OF EASTERN KENTUCKY. BASED ON UPSTREAM RADAR RETURNS...IT APPEARS THAT IT WILL BE MUCH LATER TONIGHT BEFORE WIDESPREAD PRECIPITATION BEGINS TO AFFECT THE AREA. THEREFORE...BOTH THE FORECAST GRIDS AND ZONES WERE UPDATED TO REFLECT THIS NEW TREND. THE SAME ISSUES WITH THE STORMS WILL HOLD TRUE...WITH DAMAGING WINDS...LARGE HAIL...AND LOCALLY HEAVY RAINFALL ALL STILL POSSIBLE. A LINE OF STRONG TO POTENTIALLY SEVERE THUNDERSTORMS IS NOW EXPECTED TO MOVE ACROSS THE AREA BETWEEN ROUGHLY 8 AND 13Z ON FRIDAY. THE FLASH FLOOD WATCH IS STILL IN EFFECT. UPDATE ISSUED AT 641 PM EDT THU APR 9 2015 JUST UPDATED THE GRIDS...ZONE FORECAST TEXT PRODUCT...AND HAZARDOUS WEATHER PRODUCT TO ALL REFLECT THE CANCELLATION OF SEVERE THUNDERSTORM WATCH 40. WITH ONLY A FEW MEAGER THUNDERSTORMS HAVING MOVED ACROSS THE AREA SO FAR THIS EVENING...AND WITH NO NEW STORMS EXPECTED TO AFFECT THE AREA ANY TIME SOON...THE WATCH WAS CANCELLED. THE FLASH FLOOD WATCH IS STILL IN EFFECT. THE GRIDS WERE ALSO FRESHENED UP A BIT USING THE LATEST OBS DATA ACROSS THE BOARD. WILL CONTINUE TO MONITOR CURRENT CONDITIONS TO DETERMINE WHEN TO ISSUE THE NEXT FORECAST UPDATE. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 351 PM EDT THU APR 9 2015 MODELS ARE IN GOOD AGREEMENT IN THE SHORT TERM WITH EASTERN KENTUCKY REMAINING UNDER BROAD SW FLOW TODAY BEFORE AN UL TROUGH SWINGS THROUGH THE AREA THIS EVENING. A WARM FRONT REMAINS TO OUR NORTH...HELPING TO FOCUS SOME OF THE MORE INTENSE CONVECTION SO FAR THIS AFTERNOON. HOWEVER...GIVEN THAT THE ATMOSPHERE IS VERY MOIST AND UNSTABLE...THERE IS STILL A CHANCE FOR SCATTERED CONVECTION ACROSS OUR CWA THIS AFTERNOON AND EVENING WITH BEST CHANCES ALONG THE NORTHERN COUNTIES WHERE A SPC SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED. AND AS THE UL TROUGH APPROACHES THE AREA ALLOWING FOR ADDITIONAL HEIGHT FALLS AND UL ENERGY...THE CHANCES FOR THUNDERSTORMS INCREASE. HIGH RES MODELS SUCH AS THE HRRR AND NAM12 BOTH INDICATE A LULL IN CONVECTION TONIGHT AFTER THE DIURNAL CONVECTION WANES AND BEFORE THE COLD FRONT REACHES OUR AREA. AS SUCH...HAVE INDICATED A DECREASE IN SHOWERS/CONVECTION DURING THAT TIME IN THE POP/SKY/WX GRIDS. BY THE TIME THE COLD FRONT REACHES KY AROUND 06Z...SHOWERS AND THUNDERSTORMS WILL BE NUMEROUS AND WIDESPREAD ACROSS THE MAJORITY OF THE STATE. PER LATEST MODEL OUTPUT AND SOUNDINGS...A CONVECTIVE LINE COULD DEVELOP ALONG AND AHEAD OF THE COLD FRONT OVERNIGHT TONIGHT...ALLOWING FOR A THREAT OF HIGH WINDS AND HEAVY RAIN. WILL HAVE TO SEE HOW THE CONVECTION FORMS WITH THE FRONTAL BOUNDARY LATER TONIGHT...BUT IT IS LIKELY THAT THERE WILL BE AT LEAST WIDESPREAD RAINFALL WITH SOME THUNDERSTORMS AS THE FRONT PASSES THROUGH THE REGION TONIGHT. THERE WONT BE THE ADDED BENEFIT OF DAYTIME HEATING BUT THERE WILL BE ENOUGH MID TO UPPER LEVEL SUPPORT FOR CONVECTION TO SUSTAIN ITSELF. THE COLD FRONT SHOULD THEN EXIT EASTERN KY BY 18Z...FOLLOWED QUICKLY BY COOLER...DRIER AIR AND N TO NW FLOW. THE COOLER AIR BEHIND THE FRONT WILL QUICKLY CUT OFF ANY REMAINING SHOWER ACTIVITY AND DRY THE AIR...DECREASING HUMIDITY LEVELS SUBSTANTIALLY. THIS WILL ALLOW FOR TEMPERATURES TO REMAIN NEAR NORMAL VALUES...IN THE MID 60S...ON SATURDAY AS A HIGH PRESSURE SITS OVERHEAD. THIS IS A BIG CHANGE FROM TODAY/S TEMPERATURES WHICH HAVE SURPASSED THE 80 DEGREE MARK FOR THE FIRST TIME THIS YEAR. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 501 PM EDT THU APR 9 2015 A LARGE AREA OF SURFACE HIGH PRESSURE OVER THE OHIO VALLEY ON SATURDAY WILL BRING DRY WEATHER WHICH SHOULD LAST INTO SUNDAY NIGHT. BY THEN THE HIGH WILL BE MOVING OFF THE EAST COAST...AND MODELS SHOW GULF MOISTURE TRYING TO MAKE A RETURN TO THE NORTH AS ANOTHER COLD FRONT PUSHES IN FROM THE NW. IT NOW LOOKS LIKE THIS FRONT WILL BRING A QUICK CHANCE AT SOME SHOWERS ON MONDAY INTO MONDAY NIGHT. MODELS HAVE NOT BEEN CONSISTENT IN THEIR SOLUTIONS FOR TUESDAY THROUGH THURSDAY. THE 12Z RUNS OF BOTH THE GFS AND ECMWF NOW SUGGEST MAINLY DRY WEATHER FOR TUESDAY INTO WEDNESDAY AS HIGH PRESSURE SLIDES BY TO OUR NORTH...AND THE AFOREMENTIONED COLD FRONT STALLS TO OUR SOUTH AND KEEPS MOISTURE AT BAY. HOWEVER...WITH THIS BEING A RECENT CHANGE...HAVE ONLY TRENDED THE POP LOWER INSTEAD OF REMOVING PRECIP FROM THE FORECAST. 12Z RUNS SHOW A RETURN OF GULF MOISTURE FROM WEDNESDAY INTO THURSDAY...BUT LITTLE IN THE WAY OF INSTABILITY AND HAVE CONTINUED CHANCE POPS FOR SHOWERS AT THAT TIME. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 205 AM EDT FRI APR 10 2015 CEILINGS WILL BE LOWERING THROUGH DAWN AS A COLD FRONT AND LINE OF CONVECTION APPROACH FROM THE WEST. THE STRONGER AND MORE WIDEPSREAD CONVECTION LOOKS TO AFFECT EASTERN KENTUCKY BETWEEN 09 AND 13Z...BEFORE DIMINISHING THROUGH THE MID AND LATE MORNING FROM WEST TO EAST AS THE COLD FRONT CROSSES THE AREA. GUSTY SOUTH TO SOUTHWEST WINDS OF 7 TO 15 KTS...WITH GUSTS OF 15 TO 20 KTS WILL VEER TO THE WEST AND NORTHWEST BEHIND THE COLD FRONT. CEILINGS WILL DROP DOWN TO MVFR AT TIMES WITHIN THE STORMS...WITH EVEN SOME TEMPORARY IFR POSSIBLE. SKIES WILL CLEAR OUT LATE THIS AFTERNOON...WITH WINDS DIMINISHING AS HIGH PRESSURE BUILDS IN. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL NOON EDT TODAY FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...GEOGERIAN SHORT TERM...JVM LONG TERM...HAL AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1133 PM CDT THU APR 9 2015 .DISCUSSION... FOR THE 10/06Z TAF ISSUANCE. && .AVIATION... A COLD FRONT EXTENDING FROM SOUTHWEST ARKANSAS TO NORTHEAST TEXAS WILL CONTINUE TO MOVE SOUTHEAST OVERNIGHT...REACHING AND MOVING THROUGH KAEX NEAR 10/12Z...THEN REACHING AND STALLING AT KBPT/KLCH AROUND 10/14-15Z...AND KLFT/KARA 10/16-17Z. STILL EXPECTING LOW CLOUDS WITH MVFR TO IFR CEILINGS AND SOME PATCHY FOG TO DEVELOP BEFORE THE FRONT ARRIVES. AS THE FRONT ARRIVES...A FEW SHOWERS WILL DEVELOP AHEAD OF IT...THEN A BAND OF SHOWERS RIGHT ALONG AND BEHIND IT. AGAIN MVFR/IFR TYPE CEILINGS EXPECTED WITH THIS ACTIVITY...ALONG WITH THE POSSIBILITY OF HEAVY RAIN REDUCING VISIBILITY IN THUNDERSTORMS...THAT SHOULD LINGER INTO THE AFTERNOON. RUA && .PREV DISCUSSION... /ISSUED 939 PM CDT THU APR 9 2015/ UPDATE... A BKN BAND OF STRONG TO SVR STORMS CONTINUES TO MARCH EAST ACRS NRN LA THIS EVENING AHEAD OF A COLD FRONT. A SECOND BAND OF TSTMS HAS FORMED ALONG THE FRONT...EXTENDING FM HOT SPRINGS ARK TO TERRELL TX. THE FRONT IS STILL ON TRACK TO REACH OUR NWRN ZONES LATE TONIGHT BETWEEN MIDNIGHT AND 3 AM. THE BAND OF SHOWERS AND TSTMS WILL GRADUALLY SHIFT SOUTH INTO THE AREA OVERNIGHT...WITH ACTIVITY BECOMING MORE WIDESPREAD DURING THE DAY FRIDAY AS THE FRONT MOVES THROUGH THE AREA. ONLY MINOR CHANGES TO GRIDS TONIGHT...MAINLY TO BRING IN LINE WITH RECENT OBS AND TRENDS. ADJUSTED THE POP/WX GRIDS FOR THE EVENING. INCORPORATED A BLEND OF RECENT HRRR RUNS...WHICH GENERALLY LOWERED POPS FOR THE EVENING. ACTIVITY HAS STAYED NORTH OF THE CWA SO FAR...BUT EXPECT IT WILL BEGIN TO AFFECT THE NRN TIER OF PARISHES AND COUNTIES TOWARD MIDNIGHT WITH CHCS INCREASING THEREAFTER. OTHERWISE...FCST SEEMS TO BE IN GOOD SHAPE. 24 PREV DISCUSSION... /ISSUED 336 PM CDT THU APR 9 2015/ DISCUSSION...SURFACE ANALYSIS INDICATING APPROACHING NE-SW ORIENTED COLD FRONT STRETCHING ACROSS WESTERN OKLAHOMA AND THROUGH CENTRAL TEXAS. RADAR MOSAIC SHOWING A FEW SHOWERS NOW DEVELOPING ALONG BOUNDARY...WITH MORE ROBUST CONVECTION DEVELOPING PRE- FRONTAL FROM SOUTHWEST ARKANSAS INTO CENTRAL TEXAS NEAR AUSTIN. OTHER THAN THAT...LOCAL AREA REMAINS CLEAR OF ANY PRECIP. CLOUDS WERE ABUNDANT TODAY BUT NONE-THE-LESS...TEMPERATURES HAVE WARMED AGAIN INTO THE LOW TO MID 80S...SEVERAL DEGREES ABOVE THE NORM. WET WEATHER PATTERN INCOMING. AFOREMENTIONED FRONTAL BOUNDARY PROGGED TO ADVANCE RAPIDLY SOUTHEAST TO ALONG A LINE FROM NEAR AEX TO BPT TOWARD SUNRISE...THEN SLOWING AND STALLING MOVING INTO THE NEAR COASTAL WATERS. FRONT THEN EXPECTED TO RETREAT RAPIDLY NORTH SUNDAY AS A WARM FRONT. LOW LEVEL CONVERGENCE WITH FRONT...ISENTROPIC ASCENT NORTH OF FRONT ALONG WITH A SERIES OF DISTURBANCES MOVING THROUGH ON A STRONG WEST TO SOUTHWEST ALOFT....WARRANTS HIGH END RAIN CHANCES BEGINNING FRIDAY AND THROUGH THE WEEKEND. SPC HAS PLACED THE FORECAST AREA WITHIN A MARGINAL TO SLIGHT RISK OF SEVERE WEATHER FOR FRIDAY. GOING INTO THE NEW WORK-WEEK...DEEP GULF/PACIFIC MOISTURE REMAINS IN PLACE THROUGH AT LEAST THURSDAY PER THE ECMWF AND GFS. THUS RESPECTABLE POPS CONTINUING. MARINE...LIGHT SOUTHERLIES WILL CONTINUE TONIGHT...BECOMING MORE EASTERLY FRIDAY AS A COLD FRONT ADVANCES INTO THE NEAR COASTAL WATERS AND STALLS. WITH THIS FRONT WILL COME A CHANCE FOR A FEW SHOWERS AND THUNDERSTORMS...WITH THIS ACTIVITY CONTINUING INTO SATURDAY. THE BOUNDARY WILL THEN LIFT NORTH AS WARM FRONT SUNDAY WITH A SOUTHERLY FLOW RETURNING. UPPER LEVEL DISTURBANCES MOVING ACROSS THE AREA WILL THEN KEEP A DAILY CHANCE FOR SHOWERS AND THUNDERSTORMS CONTINUING THROUGH MID-WEEK. 23 && .PRELIMINARY POINT TEMPS/POPS... AEX 69 77 61 77 / 40 70 30 50 LCH 71 80 65 78 / 20 70 40 60 LFT 71 82 65 78 / 10 70 40 60 BPT 71 80 66 78 / 20 70 40 60 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ AVIATION...07
AREA FORECAST DISCUSSION
NWS CARIBOU ME
602 AM EDT FRI APR 10 2015 .SYNOPSIS... WARM FRONT WILL SPREAD MIXED PRECIPITATION TO THE AREA OVERNIGHT BECOMING ALL RAIN BY AFTERNOON AS WARMER AIR MOVES INTO THE REGION. TEMPERATURES WILL BE MILD THROUGHOUT THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... 6 AM UPDATE...FIRST ROUND OF WINTRY PRECIPITATION IS CROSSING THE REGION ATTM. ONCE THIS GOES BY, WE`LL SEE A BIT OF A BREAK, THEN ANOTHER ROUND OF MAINLY RAIN TO FOLLOW THIS AFTERNOON AS THE COLD FRONT PASSES THROUGH. THE LATEST NAM WAS HANDLING THIS WELL AND MATCHED CLOSELY THE RUC AND THE HRRR. THEREFORE USED THE NAM TO ADJUST POPS AND THE PRECIP TYPE FOR TODAY. TEMPERATURES ARE CURRENTLY AT OR BELOW FREEZING AT MANY LOCATIONS AT THIS HOUR, SO STILL EXPECT A SLIPPERY COMMUTE FOR JUST ABOUT EVERYONE THIS MORNING. THE WINTER WEATHER ADVISORY THEREFORE REMAINS IN EFFECT FOR OUR ENTIRE AREA. PREVIOUS DISCUSSION...RADAR ECHOES BLOSSOMING ACRS WRN MAINE AND SPREADING INTO CWA AS OF 06Z. AIRMASS IS VRY SLOWLY SATURATING AND EXPECT PRECIP TO BEGIN BY 09Z AT BANGOR AND 10-11Z ELSEWHERE. TRICKY FCST AS TO HOW PCPN WL EVOLVE DRG THE OVRNGT HRS. VWP FROM GYX RADAR INDICATING SERLY WINDS 15-20KTS JUST OFF THE SFC DRAWING IN WM AIR. SFC TEMPS RANGE FM M20S OVR CNTRL ZONES TO L/M 30S OVR INTERIOR DOWNEAST AND COASTAL AREAS. WITH DRY DWPTS STILL IN PLACE COURTESY OF SFC RIDGE AXIS EXPECT PCPN TO WET BULB DOWN AND START OFF AS SNOW ACRS NRN SXNS IN THE NEXT SVRL HRS. WHAT LITTLE SNOW THERE IS WL QUICKLY MIX WITH SLEET AND FRZG RAIN BEFORE BCMG ALL RAIN BY 17Z THIS AFTN IN THE CROWN OF MAINE. FURTHER TO THE SOUTH WARM AIR WL RAPIDLY ENCROACH INTO AREA WITH INTERIOR DOWNEAST BCMG RAIN BY 12Z AND COASTAL SXNS STARTING OFF AS RAIN. EXPECT LOW-LVL MOISTURE TO BE PRESENT BTWN FRONTAL BNDRY DRG THE AFTN/EVNG HRS. STILL SOME QUESTION AS TO HOW FAR NORTH WMFNT CAN ACCELERATE ACRS THE MTNS THIS AFTN AS 00Z GFS INDICATING IT GETS HUNG UP ACRS SRN NEW ENGLAND 18Z TDA WITH NAM BRINGING IT INTO NRN AREAS BY THIS TIME. EITHER WAY, WITH SFC TEMPS ABV FRZG AT THIS TIME AND H8 TEMPS SURGING TO > +4C FOR ALL AREAS EXPECT ALL RAIN BY THIS TIME. CWA WL LKLY SEE FOG TONIGHT WITH MELTING SNOW AND MINIMAL DWPT DEPRESSION AS OCCLUDED FRONT TAKES ITS SWEET TIME WORKING THRU. FRONT WL EVENTUALLY MV THRU AFT 06Z WITH WINDS GOING WEST AND BRINGING IN COOLER AND DRIER AIR, POSSIBLY ENUF TO SCOUR OUT FOG. WL CONTINUE WINTER WX ADVISORY FOR GLAZE OF ICE ACROSS MOST AREAS WITH BIGGEST QUESTION MARK CENTERING ON COASTAL AREAS. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... AN UPPER TROUGH WILL SWING ACROSS THE REGION ON SATURDAY, BRINGING THE CHANCES FOR RAIN AND SNOW SHOWERS TO THE REGION. THESE WILL BE MAINLY IN THE MORNING, AND ANY ACCUMULATING SNOW WILL OCCUR IN THE HIGHER ELEVATIONS OF THE NORTH MAINE WOODS. EVEN THERE, SNOW ACCUMULATION WILL BE MINIMAL. SATURDAY`S HIGHS WILL BE MILD, RANGING FROM THE MID 40S IN THE NORTH TO AROUND 50 DOWNEAST. BUFKIT PROFILES INDICATE THERE WILL BE DEEP MIXING ON SATURDAY, WHICH WILL LEAD TO BREEZY CONDITIONS DURING THE AFTERNOON; WEST WINDS OF 10 TO 15 MPH WITH GUSTS TO 30 MPH ARE LIKELY. HIGH PRESSURE THEN BUILDS ACROSS THE REGION SATURDAY NIGHT AND SUNDAY. THERE WILL BE ENOUGH LINGERING MOISTURE SATURDAY NIGHT TO KEEP SKIES AT LEAST PARTLY CLOUDY OVER MUCH OF THE REGION. THIS WITH CONTINUING WEST TO NORTHWEST WINDS WILL LIMIT RADIATIONAL COOLING, LEADING TO A RELATIVELY MILD NIGHT. LOWS WILL RANGE FROM AROUND 30 IN THE NORTH TO THE LOWER TO MID 30S DOWNEAST. A WEAK DISTURBANCE WILL CROSS THE REGION ON SUNDAY, WHICH MAY LEAD TO A FEW SPRINKLES OVER THE NORTH DURING THE AFTERNOON. TEMPERATURES WILL BE A LITTLE WARMER THAN THOSE ON SATURDAY; HIGHS WILL BE IN THE UPPER 40S TO AROUND 50 IN THE NORTH AND CENTRAL PARTS OF OUR AREA AND THE LOWER 50S DOWNEAST. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... HIGH PRESSURE WILL DOMINATE THE AREA`S WEATHER SUNDAY NIGHT INTO MONDAY. HOWEVER, IT WILL GIVE WAY BY MONDAY AFTERNOON AS LOW PRESSURE MOVING ACROSS THE HUDSON BAY BRINGS A COLD FRONT TOWARD NEW ENGLAND. PRECIPITATION CHANCES WILL INCREASE THROUGH MONDAY AFTERNOON, BUT THE BULK OF THE PRECIPITATION WILL FALL OVERNIGHT MONDAY NIGHT ALONG WITH THE ACTUAL FRONTAL PASSAGE. EXPECT MAINLY RAIN WITH THIS FRONT, ALTHOUGH SOME SNOW MAY MIX IN LATE MONDAY NIGHT IN THE HIGHER ELEVATIONS OF THE NORTH MAINE WOODS. LINGERING WRAP-AROUND SHOWERS WILL BE POSSIBLE TUESDAY, ESPECIALLY ACROSS THE NORTH AND WEST. HIGH PRESSURE WILL BUILD TO OUR SOUTH ON WEDNESDAY, AND WHILE MUCH OF THE REGION WILL BE DRY AS A RESULT, A FAST-MOVING UPPER DISTURBANCE WILL MOVE ACROSS THE CANADIAN MARITIMES ON WEDNESDAY AND MAY PRODUCE A FEW SHOWERS OVER FAR NORTHERN MAINE. OTHERWISE, EXPECT DRY CONDITIONS FOR THE WEDNESDAY-THURSDAY TIMEFRAME. TEMPERATURES WILL STAY MILD THROUGH THE EXTENDED, WITH HIGHS IN THE 50S AND EVEN APPROACHING 60 FOR INTERIOR DOWNEAST. OVERNIGHT LOWS WILL BE IN THE 30S MOST NIGHTS, THOUGH CAN`T RULE OUT SOME 20S ACROSS THE NORTH ON WEDNESDAY NIGHT. && .AVIATION /10Z FRIDAY THROUGH TUESDAY/... NEAR TERM: VFR AT NRN TERMINALS WITH MVFR AT BGR AND BHB EARLY ON. MIXED PRECIPITATION MOVES IN WITH -SN AT FVE, CAR, PQI AND HUL BETWEEN 10Z AND 12Z-14Z BEFORE MIXING WITH -FZRAPL. IFR EXPECTED THRU END OF TAF VALID TIME IN FOG AND/OR DRIZZLE AT ALL SITES. BHB WILL LIKELY SEE -RA THRU 22Z TDA WITH BGR BECOMING RAIN AFTER 12Z. SOUTHERN TERMINALS MOST LIKELY TO BE IMPACTED BY LLWS THRU 17Z. SHORT TERM: MVFR CONDITIONS WILL BE LIKELY ON SATURDAY, ESPECIALLY AT THE NORTHERN TERMINALS AS A FRONT CROSSES THE REGION. THIS WILL PRODUCE CEILINGS AOB 3000 FT AS WELL AS SCATTERED RAIN AND SNOW SHOWERS, AGAIN, MAINLY IN THE NORTH. WINDS WILL INCREASE BEHIND THE FRONT, WITH GUSTS TO 30 KT POSSIBLE. CONDITIONS LOOK TO BECOME VFR AND REMAIN SO THROUGH THE REST OF THE WEEKEND AND INTO EARLY NEXT WEEK. THE NEXT CHANCE OF SIGNIFICANT PRECIPITATION ARRIVES WITH ANOTHER FRONTAL PASSAGE MONDAY NIGHT AND TUESDAY. && .MARINE... NEAR TERM: WL CONTINUE SCA INTO TONIGHT AS SEAS REMAIN ABOVE 5KT. WIND GUSTS REMAIN LOW DUE TO STABLE AIRMASS OVER WATERS. SHORT TERM: A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FOR SATURDAY AS WINDS AND WAVES WILL BUILD IN RESPONSE TO A FRONTAL PASSAGE. THEREAFTER, CONDITIONS LOOK TO BE FAIRLY QUIESCENT AS HIGH PRESSURE BUILDS ACROSS THE WATERS FOR SUNDAY AND MONDAY. && .HYDROLOGY... THE TOTAL QPF FROM THIS UPCOMING EVENT STILL LOOKS TO BE AROUND 0.50" FOR MOST OF THE HSA W/A COMBO OF SLEET/FREEZING RAIN THIS MORNING CHANGING TO RAIN BY LATE MORNING/EARLY AFTERNOON. THE SNOWPACK INITIALLY WILL BE ABLE TO ABSORB THE LIQUID. WARMER TEMPERATURES LATER FRIDAY INTO FRIDAY NIGHT WILL LEAD TO FURTHER EROSION OF THE SNOWPACK AND RUNOFF. THEREFORE, RISES ON STREAMS AND RIVERS ARE EXPECTED ALONG WITH ICE MOVEMENT. THE BIGGER CONCERN CONTINUES TO BE THE EXPECTED WARMUP FOR EARLY NEXT WEEK THAT WILL PUSH TEMPERATURES TOWARD 60 DEGREES IN MANY AREAS. IN ADDITION, OVERNIGHT LOWS WILL BE AT OR ABOVE FREEZING BOTH MONDAY AND TUESDAY NIGHTS. BELOW FREEZING TEMPERATURES ARE FAVORABLE IN THAT THEY RESULT IN A "PAUSE" IN RUNOFF AND SLOW RIVER RISES. WITH THE LONG STRETCH OF MILD AND ABOVE FREEZING TEMPERATURES, SIGNIFICANT SNOW MELT AND RUNOFF WILL CAUSE WATER LEVELS TO RISE ON AREA WATERWAYS AND COULD CAUSE ICE TO MOVE AND POTENTIALLY JAM. THIS COULD LEAD TO ICE JAM FLOODING. OUR MORE CENTRAL RIVERS, INCLUDING THE PENOBSCOT AND PISCATAQUIS AND THEIR TRIBUTARIES, HAVE THE BEST CHANCE OF SEEING ICE MOVEMENT EARLY NEXT WEEK. FURTHER NORTH, ALONG THE ST JOHN AND AROOSTOOK RIVERS, THE ICE IS STRONGER AND OVERNIGHT TEMPERATURES WILL BE CLOSER TO FREEZING, WHICH COULD DELAY POTENTIAL BREAKUP UNTIL LATE IN THE WEEK INTO THE WEEKEND WHEN MODEL GUIDANCE IS TRYING TO INDICATE A POTENTIAL HEAVIER RAIN EVENT. THIS WILL CONTINUE TO BE MONITORED. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...WINTER WEATHER ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR MEZ001>006-010-031. WINTER WEATHER ADVISORY UNTIL 11 AM EDT THIS MORNING FOR MEZ011-015>017-032. WINTER WEATHER ADVISORY UNTIL 9 AM EDT THIS MORNING FOR MEZ029- 030. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ050- 051. && $$ NEAR TERM...FARRAR/HASTINGS SHORT TERM...HASTINGS LONG TERM...HASTINGS AVIATION...FARRAR/HASTINGS/HASTINGS MARINE...FARRAR/HASTINGS/HASTINGS HYDROLOGY...
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
349 AM EDT FRI APR 10 2015 .SHORT TERM...TODAY AND TONIGHT THE LOW PRESSURE SYSTEM WHICH PULLED THE ACTIVE WARM FRONT UP THROUGH SE MI LATE THURSDAY IS NOW LOCATED OVER NORTHERN LOWER MI. IT WILL CONTINUE TO DEEPEN AS IT LIFTS NE THROUGH THE DAY. LINGERING CONVECTION OVER THE SAGINAW VALLEY AND THUMB SHOULD LIFT OUT OF THE AREA IN THE NEXT FEW HOURS. THIS AREA HAS SPLIT FROM THE COLD FRONTAL CONVECTION LOCATED TO OUR SOUTH OVER IN/OH...WHICH HAS BEEN ADVERTISED BY THE HRRR FOR THE LAST FEW MODEL RUNS. A FEW SHOWERS WILL CONTINUE TO POP UP IN THE PRE-FRONTAL AIRMASS BUT NOT MORE THAN A CHANCE POP FOR ANY LOCATION. AS THE CONVECTION BEGINS TO WANE...ATTENTION TURNS TOWARD WINDS. SOUTHERLY FLOW AHEAD OF THE COLD FRONT HAS BEEN ABLE TO GUST UP TO 25 KNOTS OVER SW LOWER MI. THIS WILL DRIFT ACROSS THE STATE OVER US PRIOR TO 09Z. WINDS WILL VEER TO WESTERLY BEHIND THE FRONT AND INCREASE FURTHER AS THE TIGHT E/W PRESSURE GRADIENT LIFTS UP INTO SE MI. THESE POST FRONTAL WINDS HAVE BEEN GUSTING TO AROUND 35 KNOTS THROUGH THE NIGHT ACROSS IA/IL/MO WITH AN INITIAL POP RIGHT BEHIND THE FRONT CLOSER TO 40 KNOTS. MODELS SHOW THIS TREND CONTINUING ACROSS SOUTHERN MI THROUGH THE AFTERNOON WITH ADDITIONAL DIURNAL SUPPORT. MODEL SOUNDINGS SHOW A DEEP MIXED LAYER DEVELOPING BEHIND THE FRONT UP TO AROUND 850MB WITH STEEP LL LAPSE RATES DUE TO IMPRESSIVE CAA BETWEEN THE SFC AND 700MB. IN THIS MIXED LAYER...MODELS ARE SHOWING WINDS OF AROUND 50 KNOTS AS LOW AS 925MB IN THE COLUMN PEAKING FROM 09-14Z BEFORE SLOWLY DIMINISHING. THIS SHOULD PRODUCE WIDESPREAD WIND GUSTS AROUND 40-50 MPH AT THE SFC THUS THE WIND ADVISORY WAS ISSUED THURSDAY AFTERNOON. THERE DOES REMAIN THE CHANCE OF HIGHER GUSTS REACHING THE SFC...ESPECIALLY IF A FEW SHALLOW CONVECTIVE CELLS CAN DEVELOP AS THE LINGERING TROUGH SWINGS THROUGH. AT THIS POINT WILL HOLD WITH THE ADVISORY AND ALLOW THE NEXT SHIFT TO ASSESS TRENDS HEADING INTO THE DIURNAL CYCLE. A SHORT FUSE HIGH WIND WARNING IS NOT OUT OF THE QUESTION. SOME LINGERING SHOWERS WILL PERSIST THROUGH THE AFTERNOON SLOWLY WANING TOWARD THE EVENING HOURS. MODELS ARE ALL SHOWING A COMPACT VORT MAX DIVING INTO THE BACKSIDE OF THE EXITING TROUGH AND TRACKING ACROSS THE MI/OH BORDER BETWEEN ABOUT 00-06Z SATURDAY. ADDED A CHANCE OF SHOWERS FOR THIS PERIOD TO ACCOUNT FOR THE GOOD MODEL AGREEMENT WITH THIS FEATURE. && .LONG TERM...SATURDAY THROUGH THURSDAY SE MI WILL BE INFLUENCED BY HIGH PRESSURE TRACKING FROM THE OHIO VALLEY INTO THE MID ATLANTIC DURING THE COURSE OF THE WEEKEND...ASSOCIATED WITH A BROAD MID LEVEL RIDGE FCST TO BUILD FROM THE UPPER MIDWEST TO THE ERN GREAT LAKES. THIS WILL SUPPORT A DRY FORECAST THROUGH THE WEEKEND. THE CORE OF LOW LEVEL COLD AIR WILL PUSH OFF TO THE EAST DURING THE DAY SATURDAY BUT WILL STILL SUPPORT DAYTIME HIGHS ONLY IN THE 50S. LOW LEVEL WARMING WILL GET A BOOST ON SUNDAY UNDER STRENGTHENING LOW LEVEL SOUTHERLY WINDS. THIS AND DECENT MIXING DEPTHS SUGGEST DAYTIME HIGHS ON SUN WILL RISE WELL INTO THE 60S. A FAST MOVING MID LEVEL SHORT WAVE IS FORECAST TO EJECT OUT OF THE GULF OF ALASKA UPPER LOW AND TRACK ACROSS THE NRN GREAT LAKES SUN NIGHT INTO MONDAY. THERE IS REASONABLE AGREEMENT AMONG THE LATEST GFS AND ECMWF IN BRINGING THE ASSOCIATED SFC FRONT ACROSS SE MI MON MORNING. THE BETTER LARGE SCALE DYNAMICS ARE SHOWN TO PASS ACROSS THE NRN GREAT LAKES REGION. FORECAST AMPLIFICATION OF THE MID LEVEL WAVE AS IT ROTATES INTO THE WRN GREAT LAKES WILL HOWEVER OFFER AN OPPORTUNITY FOR INCREASED LOW LEVEL SW FLOW TO ADVECT A PLUME OF DEEP MOISTURE INTO LOWER MI ALONG/AHEAD OF THE SFC FRONT. THIS WILL REMAIN SUPPORTIVE OF A CHANCE OF SHOWERS LATE SUN NIGHT THROUGH MON MORNING. COOLER AND DRIER AIR WILL ADVECT INTO THE REGION IN THE WAKE OF THIS FRONT. DAYTIME HEATING AND DRY AIR ADVECTION WILL HOWEVER BOOST MIXING DEPTHS AND SHOULD REMAIN SUPPORTIVE OF HIGHS INTO THE 60S BOTH MON AND TUES. REBOUNDING MID LEVEL HEIGHTS ACROSS THE REGION AND DEVELOPING SOUTHERLY FLOW WILL SUPPORT TEMPS ON THE WARM SIDE OF MID APRIL SEASONAL NORMS DURING THE REMAINDER OF NEXT WEEK. && .MARINE... GALE WARNINGS REMAIN IN EFFECT FOR ALL MARINE AREAS TODAY. A DEEP LOW PRESSURE SYSTEM WILL TRACK ACROSS NORTHERN LAKE HURON THIS MORNING BEFORE LIFTING NORTHEAST OF THE REGION DURING THE AFTERNOON. THIS SYSTEM IS NOW DRIVING A STRONG COLD FRONT ACROSS THE GREAT LAKES. OBSERVATIONS ON THE COLD SIDE OF THIS FRONTAL SYSTEM ARE IN STRONG SUPPORT OF WIDESPREAD GALES. GALES WILL STEADILY DIMINISH TONIGHT AS THE GRADIENT RELAXES AND HIGH PRESSURE BUILDS INTO THE OHIO VALLEY/SRN GREAT LAKES. THIS HIGH WILL INFLUENCE THE REGION DURING THE WEEKEND AND WILL SUSTAIN LIGHT WINDS ON SATURDAY. DESPITE A STRENGTHENING SOUTHERLY WIND ON SUNDAY AS THE HIGH DEPARTS TO THE MID ATLANTIC...STRONG STABILITY OVER THE COLD LAKES WILL KEEP WIND SPEEDS BELOW 20 KNOTS. && .AVIATION...ISSUED 125 AM EDT FRI APR 10 2015 COMPLEX FORECAST WITH A COLD FRONT BRINGING A BROKEN LINE OF SHOWERS AND THUNDERSTORMS ACROSS SOUTHERN MICHIGAN...FOLLOWED BY STRONG GUSTY WINDS. THE SOUTHERN FLANK OF THE LINE OF SHOWERS/THUNDERSTORMS HAS BEEN WEAKENING DURING THE TREK EAST BUT NEW DEVELOPMENT OF SHOWERS COMING NORTH FROM INDIANA WILL WARRANT A TEMPO FOR SHOWERS FOR THE DETROIT TAFS AND PTK. MBS WILL BEGIN THE PERIOD WITH STORMS AND FNT IS ON THE BUBBLE REGARDING THE LINE OF STORM AS THEY MAY WEAKEN TO SHOWERS BY THE TIME THEY APPROACH THE TAF SITE. ONCE THE COLD FRONT PASSES EARLY THIS MORNING THE WINDS WILL INCREASE RAPIDLY. LOOK FOR EARLY AFTERNOON PEAK GUSTS REACHING OR EXCEEDING 40 KNOTS AFTER 12Z BEFORE DROPPING OFF IN THE EVENING. FOR DTW...LOW PROBABILITY OF THUNDERSTORMS WITH THE COLD FRONT LATER IN THE 08-11Z TIMEFRAME. SOUTHERLY SFC WINDS WILL VEER TO SOUTHWESTERLY AFTER THE FROPA AROUND 10Z AND WILL GUST TO 25-30KTS. WINDS WILL FURTHER VEER TO WESTERLY DURING THE DAY FRI...GUSTING TO 40 KTS OR HIGHER. //DTW THRESHOLD PROBABILITIES... * MEDIUM FOR CEILINGS AOB 5KFT THIS MORNING...LOW AFTER 15Z. * LOW THAT TSTORMS WILL IMPACT KDTW FROM 06-10Z. * HIGH IN EXCEEDING CROSSWIND THRESHOLDS FROM 260-280 DEGREES FRIDAY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MIZ047>049-053>055- 060>063-068>070-075-076-082-083. LAKE HURON...GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR LHZ363-421-422- 441>443-462>464. GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EDT SATURDAY FOR LHZ361-362. LAKE ST CLAIR...GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR LCZ460. MICHIGAN WATERS OF LAKE ERIE...GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR LEZ444. && $$ SHORT TERM...DRK LONG TERM....SC MARINE.......SC AVIATION.....DRK YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
154 AM EDT FRI APR 10 2015 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 330 PM EDT THU APR 9 2015 STRENGTHENING LOW PRESSURE PASSING JUST WEST OF MICHIGAN WILL BRING THE POTENTIAL FOR SEVERE THUNDERSTORMS THIS EVENING FOLLOWED BY RATHER WINDY CONDITIONS ON FRIDAY. HIGH PRESSURE WILL PROVIDE A PLEASANT WEEKEND. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 330 PM EDT THU APR 9 2015 POTENTIAL FOR DAMAGING THUNDERSTORM WINDS AND PERHAPS EVEN A FEW TORNADOES WILL INCREASE LATER THIS AFTERNOON AND ESPECIALLY THIS EVENING... MAINLY ALONG/SOUTH OF I-96. THE THREAT WILL END SHORTLY AFTER MIDNIGHT. WARM UNSTABLE AIR MASS TO OUR SOUTHWEST IS EXPECTED TO SURGE INTO THE AREA AFTER 5 PM NOW THAT THE POTENT SHORTWAVE OVER KS/NE IS EJECTING NORTHEAST. THIS FEATURE TAKES ON A NEGATIVE TILT AS IT MOVES TOWARD WISCONSIN LATER THIS EVENING... LEADING TO A DEEPENING OF THE SFC LOW AS IT MOVES TOWARD THE MILWAUKEE AREA. THIS SYNOPTIC SET UP WITH A STRONG WARM FRONT/TRIPLE POINT EXTENDING EAST OF THE DEEPENING SFC LOW LEADS TO STRONG CONCERNS FOR ROTATING CELLS AND SPIN UPS NEAR THE WARM FRONT THIS EVENING AS IT MOVES INTO SWRN LWR MI... DUE TO HIGH LOW LEVEL SHEAR VALUES AND POTENTIALLY AVAILABLE UPDRAFT HELICITY. TORNADO WATCHES ARE ALREADY IN EFFECT JUST UPSTREAM OF SW LWR MI AND THE LATEST WATCH... 41... HAS A MEAN STORM MOTION VECTOR OF 240 DEGREES AT 40 KTS. IT SEEMS REASONABLE AT THIS POINT TO BELIEVE WE WILL SEE SFC BASED CAPES OF 1000-1500 J/KG ARRIVING FROM THE SOUTHWEST TOWARD 00Z BASED ON LATEST RUC GUIDANCE AND MESOANALYSIS TO OUR SW. THE OTHER CONCERN THIS EVENING IS FOR LINES/BOWS TO DEVELOP IN THE UPSTREAM TORNADO WATCH AREAS AND RACE RAPIDLY EAST/NORTHEAST ACROSS PARTS OF SW MI. THESE FEATURES COULD PRODUCE DAMAGING STRAIGHT LINE WIND GUSTS AHEAD OF THE COLD FRONT. ALTHOUGH ANY STRONG/SEVERE CONVECTION WILL END AFTER MIDNIGHT WITH THE PASSAGE OF THE SFC COLD FRONT... STRONG SYNOPTIC WIND GUSTS BEHIND THE FRONT DUE TO CONTINUED DEEPENING OF THE SFC LOW OVR NRN LWR MI WILL LEAD TO SOME GUSTS TO 50 MPH OVERNIGHT INTO FRIDAY. CONVECTIVE SHOWERS WITH HIGH CLOUD BASES UNDER THE UPPER LOW ON FRIDAY COULD HELP PROMOTE STRONG GUSTS AS WELL. WILL ISSUE A WIND ADVISORY FOR LATE TONIGHT AND FRIDAY. THINGS QUIET DOWN CONSIDERABLY FRIDAY NIGHT AS HIGH PRESSURE BUILDS IN. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 330 PM EDT THU APR 9 2015 WARMER THAN NORMAL WEATHER FOR A CHANGE FROM SUNDAY AT LEAST INTO WEDNESDAY OF NEXT WEEK. STILL A CHANCE OF A WET STRETCH ON WEDNESDAY OR THURSDAY BUT TIMING IS REALLY UNCERTAIN. OVERALL PATTER IS SOMEWHAT PROGRESSIVE WITH GOOD NWP AGREEMENT ON WEST COAST TROF AND EAST COAST RIDGE DEVELOPING EARLY NEXT WEEK. SUCH A PATTERN WILL PROVIDE THE WARMTH WITH POSITIVE H85 TEMPS THROUGHOUT NEXT WEEK. AFTER MID 60S ON SUNDAY A COLD FRONT WILL PUSH THROUGH MONDAY MORNING. THINKING IT WILL LIKELY COOL MONDAY BY JUST A FEW DEGREES OVER SUNDAY AS THE UPSTREAM HIGH IS WEAK AND THERE IS JUST NOT MUCH OF A PUSH OF COLD AIR. THERE WILL BE SOME DECENT MOISTURE ADVECTION ALONG AND AHEAD OF THE FRONT SUNDAY EVENING SO STILL THINKING SCT SHOWERS ARE A GOOD BET WITH THE FRONTAL PASSAGE ITSELF. IN ANY CASE IT SHOULD BE A QUICK HITTER AND AT LEAST THE LATTER HALF OF MONDAY WILL BE DRY AND SEASONABLE. AFTER THAT THERE IS MUCH DISAGREEMENT ON HOW PROGRESSIVE WEST COAST TROF WILL BE AND HOW MUCH AND WHEN WILL A SOUTHERN STREAM SHORTWAVE EJECT NORTHEAST TOWARDS THE MISSISSIPPI VALLEY AND THEN GREAT LAKES. EACH OF THE PAST FEW DAYS THE GFS/ECM HAVE BEEN DELAYING THE SYSTEM BY A DAY...YESTERDAY THE SIGNAL WAS FOR A WEDNSDAY EVENT WHILE TODAY IT IS NOW LOOKING LIKE A THURSDAY EVENT. BASICALLY...THE POTENTIAL HIS SMEARED OUT IN THE FORECAST WITH CHANCE POPS FOR TUE NIGHT INTO THURSDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 154 AM EDT FRI APR 10 2015 THE LINE OF THUNDERSTORMS SHOULD CLEAR THE EASTERN TAF SITES BY 09Z AND LIKELY WILL NOT IMPACT THE I-94 TAF SITES...MEANING ONLY LAN SHOULD SEE ANY STORMS FROM WHAT REMAINS OF THIS LINE. THERE IS A NARROW AREA OF CLEARING BEHIND THE CONVECTION THEN THE MVFR CIGS WILL FOLLOW MOSTLY AFTER 09Z AND SPREAD WEST TO EAST ACROSS THE CWA BEHIND THE COLD FRONT WITH WEST WINDS OF 25 KNOTS GUSTING TO 35 KNOTS AT TIMES. THERE COULD BE SOME LIGHT RAIN SHOWERS IN THE 12Z TO 18Z TIME FRAME FROM WRAP AROUND MOISTURE BUT SKIES SHOULD CLEAR IN THE AFTERNOON. WINDS WILL DIMINISH BY EVENING. && .MARINE... ISSUED AT 330 PM EDT THU APR 9 2015 WILL UPGRADE THE GALE WATCH TO A WARNING AS WINDS INCREASE DRAMATICALLY OUT OF THE WEST LATER TONIGHT BEHIND THE COLD FRONT. ALSO AREAS OF DENSE FOG WILL IMPACT LK MI UNTIL AROUND OR SHORTLY AFTER MIDNIGHT AS THE DRIER AIR AND STRONG WINDS ARRIVE. && .HYDROLOGY... ISSUED AT 534 PM EDT THU APR 9 2015 2 TO 3 INCHES OF RAIN HAS FALLEN IN THE PAST 15 HOURS IN PORTIONS OF OTTAWA... KENT... AND OCEANA COUNTIES. 1 TO 2 INCHES HAS FALLEN IN MANY LAKESHORE AND CENTRAL MICHIGAN COMMUNITIES... AND A QUARTER INCH TO 1 INCH IN SOUTHERN MICHIGAN. A FEW RIVERS HAVE BEGUN RISING. THE ROGUE BELOW ROCKFORD IS ALREADY ABOVE BANKFULL. SEVERAL OTHER RIVERS ARE FORECAST TO RISE ABOVE OR CLOSE TO BANKFULL. AS SUCH... RIVER FLOOD ADVISORIES HAVE BEEN ISSUED IN ADDITION TO THE AREAL FLOOD ADVISORY. RIVERS WILL BE CLOSELY MONITORED TONIGHT AS MORE RAINFALL IS EXPECTED. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MIZ037>040-043>046- 050>052-056>059-064>067-071>074. LM...GALE WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR LMZ844>849. && $$ SYNOPSIS...MEADE SHORT TERM...MEADE LONG TERM...COBB AVIATION...WDM HYDROLOGY...CAS MARINE...MEADE
AREA FORECAST DISCUSSION
NWS DULUTH MN
314 AM CDT FRI APR 10 2015 .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 314 AM CDT FRI APR 10 2015 A COUPLE OF UPPER LEVEL LOWS WERE AFFECTING THE FORECAST AREA AT 07Z. ONE WAS LOCATED IN NW MN AND THE SECOND IN CENTRAL WI. THEIR ASSOCIATED TROFS WERE ROTATING THROUGH THE AREA AS WELL AND DRIVING SOME PCPN...MAINLY A RAIN/SNOW MIX OVER THE WESTERN EDGE OF THE REGION. THE LAST OF THE SNOW WAS OVER THE FAR EASTERN EDGE OF THE NW WI FORECAST AREA WHERE COLDEST CLOUD TOPS WERE FOUND. THE SNOW IN NW WI WILL EXIT THE AREA BY 815Z AND HAVE CANCELED THE ADVISORY WITH NO ADDITIONAL ACCUMULATION EXPECTED. SOME ADDITIONAL SNOW SHOWERS WILL BE FOUND UNTIL 15Z OVER THIS SAME AREA. NOT EXPECTING ANY ADDITIONAL ACCUMULATION EVEN THOUGH A NW WIND OVER LAKE SUPERIOR WILL OCCUR. THE REASON...LOW LEVEL WAA IN THE 1000-900MB LEVEL WILL OFFSET ANY POTENTIAL ACCUMULATION. WILL MAINTAIN THE DENSE FOG ADVISORY OVER SOUTHERN ST. LOUIS AND CARLTON COUNTIES WITH VSBYS BELOW FIVE EIGHTHS OF A MILE EXPECTED THROUGH 12Z. THE UPPER LOW/TROF IN NW MN IS PROGGED TO MOVE TO SE MN BY 18Z TODAY. NOT ANTICIPATING ANY WIDESPREAD PCPN...BUT DO HAVE SOME POPS FROM 20Z TO 22Z OVER SOUTHERN SAWYER COUNTY WHERE ENOUGH FORCING FROM THE PASSING UPPER TROF MAY GENERATE A FEW SHOWERS. THIS IS SEEN IN THE LAST FEW RUNS OF THE HRRR MODEL...AS WELL AS THE 00Z RUN OF THE ARW AND NMM. OTHERWISE...HIGH PRESSURE WILL BE BUILDING ACROSS THE REST OF THE FORECAST AREA. UPPER LEVEL AND SFC RIDGING COVER THE AREA TONIGHT AND SLIP OFF TO THE EAST ON SATURDAY. WEAK WAA IS ON TAP FOR TONIGHT AND A BIT STRONGER ON SATURDAY. AN UPPER LEVEL TROF CROSSES INT