Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/26/15


AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
630 PM CDT THU JUN 25 2015 .AVIATION... ISOLATED TSRA WILL DISSIPATE...WITH VFR CONDITIONS PREVAILING DURING THE OVERNIGHT HOURS. A LINE OF TSRA WILL DEVELOP TO THE NORTHWEST AFTER 26/15Z...AND WILL MOVE INTO THE STATE DURING THE DAY. HAVE ADDED VCTS/PROB30 GROUPS FOR THE END OF THIS TAF CYCLE. && .PREV DISCUSSION... /ISSUED 220 PM CDT THU JUN 25 2015/ SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT TODAY...HAVE CONTINUED TO SEE A FEW CLOUDS BEGIN TO POP IN THE HEAT OF THE DAY...GENERALLY ACROSS SOUTHERN ARKANSAS. WITHIN THE PAST HOUR OR TWO... HAVE BEGUN TO SEE A FEW SHOWERS AND THUNDERSTORMS FIRE IN NORTHERN LOUISIANA. AT THIS TIME...DO HAVE POPS ACROSS SOUTHERN ARKANSAS. HRRR SUGGESTS STORMS COULD FIRE AS FAR NORTH AS LITTLE ROCK...BUT DO HAVE SOME DOUBTS THAT CENTRAL ARKANSAS WILL SEE RAIN. AS A RESULT...KEPT SLIGHT CHANCE POPS LIMITED TO SOUTHERN ARKANSAS. UPPER LEVEL RIDGE HAS BEGUN TO RETROGRADE TO THE WEST WITH WESTERLY FLOW SETTING UP ALOFT. NORTHWESTERLY FLOW WILL BE MOVING INTO THE REGION AND HELP TO DRIVE A FRONT INTO THE STATE ON FRIDAY. 12Z WRF SUGGESTS PRECIP WILL BE IN PLACE ACROSS NORTHERN ARKANSAS BEFORE 12Z ON FRIDAY. DO THINK THE FRONT WILL BE A BIT QUICKER THAN THE MODELS SUGGEST...BUT BELIEVE THE WRF IS MUCH TOO QUICK. THEREFORE JUST KEPT CHANCE POPS MENTIONED ACROSS NORTHERN ARKANSAS DURING THE MORNING HOURS. AMPLE CAPE WILL BE AVAILABLE AHEAD OF THE FRONT ON FRIDAY WITH DEEP LAYER SHEAR AROUND 30 KNOTS. MID LEVEL LAPSE RATES...WILL NOT BE OUTRAGEOUS...BUT DO EXPECT DAMAGING WIND GUSTS TO BE THE PRIMARY THREAT. IT DOES APPEAR THE COLD FRONT WILL CLEAR THE STATE BY MID MORNING ON FRIDAY WITH DRY AND NOTICEABLY COOLER AND DRIER AIR FILTERING INTO THE STATE. DRY WEATHER WILL BE SHORT LIVED AS THE NEXT CHANCE FOR PRECIPITATION MOVES INTO NORTHERN ARKANSAS AS THE SHORT TERM ENDS. LONG TERM...MONDAY THROUGH THURSDAY FLOW ALOFT WILL BE FROM THE NW OVER THE REGION AT THE START OF THE LONG TERM PERIOD AS AN ELONGATED UPPER RIDGE WILL BE OVER THE ROCKIES...WITH A TROUGH OVER THE GREAT LAKES REGION. A NEW COLD FRONT WILL SLOW OVER PORTIONS OF THE STATE...WITH CHANCES FOR SHOWERS AND THUNDERSTORMS RETURNING. INITIALLY...BEST POPS WILL BE ACROSS THE NRN COUNTIES...BUT DO THINK SOME CHANCES FOR PRECIP WILL EXIST FURTHER SOUTH BY LATE MON INTO TUE WITH THE FRONT WASHING OUT. SRLY FLOW WILL RETURN FOR TUE AND THROUGH MUCH OF THE REST OF THE FORECAST...WHICH WILL ALLOW FOR TEMPS TO INCREASE FROM JUST BELOW NORMAL...TO AROUND NORMAL FOR MUCH OF NEXT WEEK. CHANCES FOR DIURNALLY DRIVEN CONVECTION WILL BE SEEN...ESPECIALLY WITH THE UPPER RIDGE REMAINING WEST OF THE STATE...AND AR IN GENERAL NW FLOW ALOFT. BY THE END OF NEXT WEEK...ANOTHER COLD FRONT WILL ATTEMPT TO MOVE INTO THE STATE...WITH ANOTHER SHOT OF COOLER AIR AND MORE CHANCES FOR PRECIP. && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$ AVIATION...58
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
227 PM CDT WED JUN 24 2015 .SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT QUITE A BIT OF CLOUDS HAVE BEEN POPPING UP AROUND THE STATE TODAY WITH TEMPS AND DEW POINTS FAIRLY SIMILAR TO WHAT WAS SEEN YESTERDAY. HAVE ALREADY BEGAN TO SEE A FEW SHOWERS AND THUNDERSTORMS FIRE ALONG THE MISSISSIPPI RIVER...AND THEREFORE HAVE ADDED POPS TO MUCH OF THE EASTERN PORTIONS OF THE CWA. BOTH HRRR AND WRF AGREE POP UP SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE IN EASTERN ARKNASAS...HOWEVER DO BELIEVE THE BETTER CHANCES FOR PRECIPITATION WILL REMAIN EAST OF THE RIVER AND THUS JUST HAVE SLIGHT CHANCE POPS AT THIS TIME. SIMILAR CONDITIONS WILL BE EXPECTED ON THURSDAY WITH CHANCES FOR DIURNALLY DRIVEN PRECIPITATION ACROSS SOUTHERN AND EASTERN ARKANSAS. CONDITIONS WILL ONCE AGAIN BE HOT AND HUMID ON THURSDAY...SO A HEAT ADVISORY WILL ONCE AGAIN BE IN EFFECT. ATTENTION THEN SHIFTS TO FRIDAY AS THE UPPER LEVEL RIDGE RETROGRADES TO THE WEST AND NW FLOW ALOFT DRIVES A COLD FRONT INTO THE STATE LATE FRIDAY AND INTO SATURDAY. SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT FRIDAY AFTERNOON AND EVENING...RESULTING IN CHANCES FOR STRONG TO SEVERE THUNDERSTORMS. THE MAIN THREATS WITH THESE STORMS WOULD BE DAMAGING WINDS. DO BELIEVE THE COLD FRONT WILL CLEAR THE STATE BY MID DAY ON SATURDAY WHICH IS A LITTLE EARLIER THAN PREVIOUSLY ADVERTISED. AS A RESULT...DID BEGIN TO TREND POPS DOWN SATURDAY MORNING AND REMOVE THEM SATURDAY AFTERNOON. THIS SETS THE STAGE FOR COOLER AND DRY AIR IN THE FORECAST FOR THE LONG TERM. && .LONG TERM...SUNDAY THROUGH THURSDAY UPPER AIR PATTERNS ACROSS NORTH AMERICA WILL BE WELL AMPLIFIED AT THE START OF THIS PERIOD...WITH A 2 SIGMA RIDGE CENTERED OVER THE NORTHERN ROCKIES...AND A 2 SIGMA TROUGH CENTERED OVER THE OHIO VALLEY. WELL BELOW NORMAL TEMPERATURES ARE EXPECTED A THE START OF THE PERIOD...WITH A SLOW WARMING TREND EXPECTED THEREAFTER...AS THE PATTERN DEAMPLIFIES. && .PRELIMINARY POINT TEMPS/POPS... BATESVILLE AR 74 95 74 90 / 20 20 30 60 CAMDEN AR 73 96 75 92 / 20 20 10 40 HARRISON AR 71 93 71 85 / 10 10 30 60 HOT SPRINGS AR 74 97 75 92 / 20 10 10 50 LITTLE ROCK AR 76 96 76 93 / 20 10 20 50 MONTICELLO AR 76 96 75 93 / 20 20 20 40 MOUNT IDA AR 70 95 73 91 / 10 10 10 50 MOUNTAIN HOME AR 71 95 71 86 / 10 20 30 60 NEWPORT AR 74 96 74 90 / 20 20 30 60 PINE BLUFF AR 75 96 74 92 / 20 20 20 50 RUSSELLVILLE AR 72 96 73 92 / 10 10 20 60 SEARCY AR 73 95 74 92 / 20 10 20 60 STUTTGART AR 76 96 75 92 / 20 20 20 50 && .LZK WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 6 PM CDT THIS EVENING FOR ARKANSAS-BRADLEY- CALHOUN-CLEBURNE-CLEVELAND-DALLAS-DESHA-DREW-FAULKNER-GRANT- INDEPENDENCE-JACKSON-JEFFERSON-LINCOLN-LONOKE-MONROE-PRAIRIE- PULASKI-SALINE-WHITE-WOODRUFF. HEAT ADVISORY FROM 1 PM TO 6 PM CDT THURSDAY FOR ARKANSAS- BRADLEY-CALHOUN-CLEBURNE-CLEVELAND-DALLAS-DESHA-DREW-FAULKNER- GRANT-INDEPENDENCE-JACKSON-JEFFERSON-LINCOLN-LONOKE-MONROE- PRAIRIE-PULASKI-SALINE-WHITE-WOODRUFF. && $$ SHORT TERM...65 / LONG TERM...55
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
859 PM MDT THU JUN 25 2015 .UPDATE... ISSUED AT 858 PM MDT THU JUN 25 2015 ISOLATED SEVERE STORMS CONTINUE AT THIS HOUR BUT OVERALL TREND WILL BE WEAKENING THROUGH LATE EVENING AS STORMS EVENTUALLY MOVE BACK INTO AREAS ALREADY WORKED OVER BY EARLIER STORMS. HOWEVER...STILL EXPECT A FEW SHOWERS AND STORMS TO CONTINUE THROUGH THE NIGHT. OVERALL ONLY MINOR CHANGES MADE TO EXISTING FORECAST. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 330 PM MDT THU JUN 25 2015 CONVECTION BEGINNING OVER THE HIGHER TERRAIN AND LARIMER COUNTY AS A SHORTWAVE MOVES CLOSER OUT WYOMING. A LONG LIVED MCS....MESOSCALE CONVECTIVE SYSTEM HAS BEEN MOVING SOUTHEAST FROM WYOMING AND INTO NEBRASKA ALL DAY....AND OUTFLOW FROM THIS SYSTEM WILL LIKELY HELP KICK OFF ADDITIONAL CONVECTION THIS EVENING. DEWPOINTS IN THE UPPER 50S TO LOWER 60S ALONG WITH TEMPERATURES IN THE MID TO UPPER 80S ARE HELPING CAPES REACH IN THE 1000-2000 J/KG AND UPWARDS OF 3000 NEAR THE WY/NE BORDER. SHEAR IS EXPECTED TO INCREASE TO 35 KTS TO NEAR 50 KTS NEAR THE WYOMING BORDER. THESE INGREDIENTS ARE COMBINING TO BRING THE THREAT OF SEVERE WEATHER...MAINLY FOR LARGE HAIL AND DAMAGING OUTFLOW WINDS TO THE PLAINS TONIGHT. BEST AREA IS ALONG AND EAST OF A LINE FROM GREELEY TO LIMON. HOWEVER OUTFLOW FROM STORMS...IN ADDITION TO ENHANCED UPSLOPE FLOW THIS EVENING MAY PRODUCE OTHER STORM FURTHER WEST. SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR MOST OF THE PLAINS AND URBAN CORRIDOR FOR THIS REASON. ACTIVITY UP NEAR CHEYENNE HAS BEEN PROGGED BY THE LATEST HRRR MODEL TO BECOME THE LONG ADVERTISED POSSIBLE MCS SYSTEM TO PUSH SOUTHEAST OVER NORTHEASTERN COLORADO AND INTO KANSAS BY MIDNIGHT. THE OUTFLOW FROM THIS SYSTEM IS EXPECTED TO PUSH BACK TOWARD THE FOOTHILLS TO BRING STRATUS AND SOME FOG OVER THE PLAINS OVER NIGHT. SO EVEN THOUGH TEMPERATURES SHOULD BE COOLING TONIGHT AND INTO TOMORROW...MINIMUM TEMPERATURES WILL BE MODERATED OVER THE PLAINS UNDER WHAT STRATUS FORMS. STRATUS WILL LIKELY STICK IN ALONG THE URBAN CORRIDOR AND PALMER DIVIDE FOR MOST OF TOMORROW. THIS WILL ALLOW FOR TEMPERATURES ABOUT 5 TO 10 DEGREES COOLER THAN TODAY. EXPECT AFTERNOON SHOWERS AND THUNDERSTORMS TO FIRE OFF THE MOUNTAINS ABOVE THE STABLE STRATUS DECK FIRST...THEN SOME MAY PUSH EAST DURING THE LATE AFTERNOON OVER THE URBAN CORRIDOR AND ADJACENT PLAINS. WITH THE UPPER RIDGE PUSHING IN FROM THE WEST SLIGHTLY MORE...THIS MAY LIMIT CONVECTION OVER THE PLAINS. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 330 PM MDT THU JUN 25 2015 THE MAIN MESSAGE CONTINUES TO BE UPPER LEVEL RIDGING OVER THE GREAT BASIN DURING THE PERIOD. THIS PUTS OUR AREA UNDER A NORTH TO NORTHWEST FLOW ALOFT WITH LITTLE IN THE WAY OF DISCERNIBLE QG DYNAMICS AFFECTING OUR WEATHER. THIS ALSO KEEPS THE PLAINS SUSCEPTIBLE TO OCCASIONAL OUTFLOWS AND FRONTAL SURGES FROM CONVECTION THAT FORMS OVER THE GREAT PLAINS. ADDITIONALLY ENOUGH MOISTURE WILL LIKELY BE CAUGHT IN THE RIDGE TO KEEP THE USUAL DIURNAL CONVECTIVE CYCLE GOING. NWP BIAS-CORRECTED CONSENSUS TEMPERATURES ARE PREDICTING SEASONAL VALUES BUT SOME OF THE LATEST GUIDANCE IS SUGGESTING MUCH WARMER VALUES. WE SHALL SEE. && .AVIATION...(FOR THE TAFS THROUGH 06Z FRIDAY EVENING) ISSUED AT 858 PM MDT THU JUN 25 2015 ANOTHER BATCH OF CONVECTION DROPPING SOUTHWARD WILL KEEP THE THREAT OF STORMS IN THE FRONT RANGE METRO AREA AIRPORTS THROUGH 06Z-07Z. STRONGER STORMS MAY STILL BE SEVERE WITH HAIL AND HEAVY RAIN REDUCING VISIBILITIES. COULD SEE A FEW STORMS LINGER OVERNIGHT...AND SOME HIGH RESOLUTION MODELS CONTINUE TO SHOW ADDITIONAL ACTIVITY ALONG THE FOOTHILLS AND ADJACENT PLAINS. WILL HAVE TO FOLLOW PROGRESSION OF STORMS AND ADJUST TAFS AS NECESSARY. EXPECTING STRATUS/FOG TO PUSH IN OVER THE AREA AFTER 09Z. IFR CONDITIONS POSSIBLE FROM 09-15Z...THEN MVFR CEILINGS MAY LAST THROUGH 00Z. && .HYDROLOGY... ISSUED AT 330 PM MDT THU JUN 25 2015 STORMS MOVING RATHER QUICKLY THIS AFTERNOON AND EVENING WITH RAINFALL AMOUNTS MAINLY UNDER ONE HALF INCH. HOWEVER...WITH A RELATIVELY WET AIRMASS...COULD SEE LOCALLY HIGHER AMOUNTS UP TO AN INCH OVER THE PLAINS. FOR THIS EVENING...WITH INCREASING UPSLOPE FLOW ALONG THE FRONT RANGE...IF STORMS FIRE IN AND NEAR THE FOOTHILLS...COULD SEE HEAVY RAINFALL DEVELOP OVER PORTIONS OF THE URBAN CORRIDOR WITH RAINFALL AMOUNTS UP TO AN INCH OR TWO IN A FEW LOCATIONS. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BARJENBRUCH SHORT TERM...KRIEDERMAN LONG TERM...ET AVIATION...BARJENBRUCH HYDROLOGY...KRIEDERMAN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
350 AM MDT WED JUN 24 2015 .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 350 AM MDT WED JUN 24 2015 THE FLOW ALOFT WILL REMAIN NEARLY ZONAL TODAY THRU TONIGHT WITH SOME MID LVL MOISTURE MOVING ACROSS THE AREA. EXPECT SCT TSTMS OVER THE HIGHER TERRAIN THIS AFTN WITH WIDELY SCT ACTIVITY OVER THE VALLEYS. OVER NERN CO AN OUTFLOW BNDRY FM CONVECTION OVER NWRN NEBRASKA AND WRN SOUTH DAKOTA WILL EVENTUALLY MOVE INTO NERN CO BY MIDDAY AND THEN MOVE WESTWARD INTO THE FRONT RANGE BY MID TO LATE AFTN IF HRRR IS CORRECT. AHEAD OF THIS BNDRY WINDS ARE SUPPOSED TO BECOME MORE WNW ALONG THE FRONT RANGE AS BEST INSTABILITY STAYS OVER THE FAR NERN PLAINS FOR MOST OF AFTN. OVERALL NOT SURE HOW THINGS ARE GOING TO EVOLVE THIS AFTN SO WILL KEEP WDLY SCT TSTMS OVER THE PLAINS. BEST CHC FOR SVR LOOKS TO BE NE OF A LINE FM GREELEY TO FORT MORGAN TO LIMON WITH MARGINAL LARGE HAIL AND STG WINDS. AS FOR HIGHS WILL KEEP READINGS SIMILAR TO YESTERDAY AS 850-700 MB TEMPS CHANGE LITTLE HOWEVER IF WNW DOWNSLOPE WINDS DO DVLP ALONG THE FRONT RANGE HIGHS COULD END UP BEING A FEW DEGREES WARMER THAN FCST. FOR TONIGHT TSTMS SHOULD END OVER THE HIGHER TERRAIN DURING THE EARLY EVENING HOURS. OVER THE PLAINS MAY SEE SOME ACTIVITY LINGER INTO THE MID EVENING HOURS WITH AN OUTSIDE CHC OF AN MCS CLIPPING THE FAR NERN CORNER LATE TONIGHT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 350 AM MDT WED JUN 24 2015 A TYPICAL SUMMER WEATHER PATTERN FOR COLORADO WILL BE IN PLACE THROUGH THE FORECAST PERIOD...BRINGING TEMPERATURES AROUND SEASONAL NORMALS AND A CHANCE OR SLIGHT CHANCE OF AFTERNOON SHOWERS ACROSS THE FORECAST AREA EACH DAY. INITIALLY...MODERATE WESTERLY FLOW ALOFT WILL BE IN PLACE AS AN UPPER RIDGE CONTINUES OVER THE SOUTHEASTERN UNITED STATES. AT LOWER AND MID LEVELS... MOISTURE AND INSTABILITY WILL BE MOVING INTO THE STATE FROM THE SOUTHERN PLAINS. DAYTIME HEATING WILL DE-STABILIZE THE AIRMASS IN THE AFTERNOONS...LEADING TO THUNDERSTORM DEVELOPMENT OVER THE MOUNTAINS AND FOOTHILLS WHICH WILL DRIFT EASTWARD THROUGH THE EARLY EVENINGS. ON THURSDAY NIGHT A SURFACE COLD FRONT WILL MOVE INTO NORTHEAST COLORADO...WHICH WILL KEEP TEMPERATURES COOLER ON FRIDAY. AT THE SAME TIME HIGH PRESSURE ALOFT OVER THE WESTERN U.S. WILL STRENGTHEN...BRINGING COLORADO UNDER A MORE NORTHWESTERLY FLOW ALOFT. GULF MOISTURE AT LOW AND MID-LEVELS WILL CONTINUE MOVING INTO EASTERN COLORADO THROUGH THE WEEKEND AND EACH DAY WILL BE A BALANCE BETWEEN WEAK SUBSIDENCE DOWNSTREAM FROM THE WESTERN U.S. UPPER RIDGE AND DAYTIME HEATING OF THE AIRMASS PRODUCING THE CHANCE OF AFTERNOON SHOWERS EACH DAY. THE NORTHWESTERLY FLOW AT MID AND UPPER LEVELS COULD ASSIST IN THE DEVELOPMENT OF SHOWER ACTIVITY DUE TO FAVORABLE VERTICAL WIND SHEAR PROFILES THAT WILL RESULT. IN THE END...EACH DAY SHOULD SEE PLENTY OF SUNSHINE THROUGH MORNING AND EARLY AFTERNOONS...AND THEN THE DEVELOPMENT OF CLOUDS AND SHOWERS THROUGH THE LATE AFTERNOONS. THE EXCEPTION TO THIS MAY BE FRIDAY MORNING WHEN STRATUS AND LOW CLOUDS WILL BE POSSIBLE IN THE POST-FRONTAL AIRMASS. THIS WILL BE ADDRESSED IN LATER FORECASTS. && .AVIATION...(FOR THE TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 350 AM MDT WED JUN 24 2015 THERE IS A WK DENVER CYCLONE NR DIA SO EXPECT LOW CLOUDS AND SOME FOG TO DVLP BY 11Z TO THE N AND NW OF THE AIRPORT. IF THE WINDS BECOME LIGHT WNW THEN COULD SEE SOME STRATUS/FOG FOR A FEW HOURS THRU 14Z AT DIA. OTHERWISE EXPECT ISOLD TO WDLY SCT HIGHER BASED TSTMS WILL BE POSSIBLE IN THE 21Z-01Z TIMEFRAME WITH GUSTY OUTFLOW WINDS. AS FOR WINDS BOTH THE HRRR AND RAP SHOW WINDS BECOMING MORE WNW BY 15Z AND LASTING THRU 18Z. AFTER 18Z THEY DIVERGE AS THE RAP KEEPS THEM MAINLY WNW THRU THE REST OF THE AFTN WHILE THE HRRR HAS THEM BECOMING MORE ELY AS A WK BNDRY MOVES IN FM THE NE. FOR NOW WILL TREND MORE WITH THE HRRR SOLUTION. FOR THIS EVENING WINDS SHOULD GRADUALLY TREND TOWARDS TO MORE OF A SSW DIRECTION AND REMAIN DRAINAGE OVERNIGHT. && .HYDROLOGY... ISSUED AT 350 AM MDT WED JUN 24 2015 STORMS WILL MOVE RATHER QUICKLY THIS AFTN AND EVENING SO RAINFALL AMOUNTS SHOULD BE MAINLY UNDER A QUARTER INCH. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RPK LONG TERM...DANKERS AVIATION...RPK HYDROLOGY...RPK
AREA FORECAST DISCUSSION
NWS NEW YORK NY
745 PM EDT THU JUN 25 2015 .SYNOPSIS... WAVES OF LOW PRESSURE TRACK ALONG A STATIONARY FRONT DRAPED ACROSS THE MID ATLANTIC STATES INTO SATURDAY. ANOTHER LOW WILL TRACK FROM THE CENTRAL APPALACHIANS THROUGH SOUTHERN NEW ENGLAND FROM SATURDAY NIGHT INTO SUNDAY. WEAK HIGH PRESSURE WILL FOLLOW FOR LATER SUNDAY THROUGH MONDAY NIGHT. A COLD FRONT WILL PASS THROUGH TUESDAY NIGHT INTO WEDNESDAY MORNING...FOLLOWED AGAIN BY HIGH PRESSURE LATER WEDNESDAY THROUGH THURSDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... LATEST SATELLITE TRENDS AND OBSERVATIONS SHOW CLOUD COVER OVER THE AREA TO BE PREDOMINATELY OVERCAST DUE TO MID-HIGH CLOUDS. WITH NO EXPECTATION OF MUCH OF A CHANGE IN CLOUD COVERAGE...WILL SEE A LOWERING OF CLOUD BASE THOUGH...HAVE GONE WITH A CLOUDY FORECAST FOR TONIGHT. 23Z OBS HAVE PRECIPITATION ONLY REACHING THE GROUND FROM A HAZLETON-POTTSTOWN-PHILADELPHIA LINE...SO RADAR RETURNS REPRESENT VIRGA FARTHER EAST. BASED ON THIS...SLOWED DOWN ONSET OF PRECIPITATION THIS EVENING. FOR NOW IT APPEARS THE BEST CHANCE FOR SHOWERS SHOULD COME LATE TONIGHT FROM A COMBINATION OF LOW LEVEL LIFT/CONVERGENCE...PLUS LIFT VIA A PASSING MID LEVEL SHORTWAVE TROUGH AND COUPLED UPPER LEVEL JET STREAKS. SO BASED ON THIS LEFT POPS OVERNIGHT AT CATEGORICAL FOR NYC METRO...NE NJ AND NEARBY PARTS OF THE LOWER HUDSON VALLEY...AND LIKELY ELSEWHERE. LATEST RUC AND HRRR SUPPORT THIS LINE OF THINKING. NIGHTTIME LOWS SHOULD BE MAINLY IN THE 60S. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... LIKELY/CAT POP TO START SHOULD TAPER OFF EARLY AS THE BEST UPPER LEVEL FORCING MOVES EAST. THE AREA WILL STILL BE IN A FAVORABLE UPPER JET REGION...SO THIS IN COMBINATION WITH ANOTHER PASSING MID LEVEL SHORTWAVE AND DAYTIME HEATING/LOW LEVEL DESTABILIZATION SHOULD RESULT IN SCT AFTERNOON SHOWERS...MAINLY NORTH AND WEST OF NYC. WITH AREA IN THE COOL SECTOR EXPECT HIGHS ONLY IN THE MID AND UPPER 70S. CHANCES FOR PRECIPITATION WILL WANE FRI EVENING WITH LOSS OF HEATING/DESTABILIZATION...AND MOST OF THE NIGHT SHOULD BE DRY AS SHORTWAVE RIDGING QUICKLY MOVES ACROSS. COULD HOWEVER START TO SEE LIGHT RAIN ENTER FAR WRN AREAS TOWARD DAYBREAK AS THE UPPER RIDGE MOVES EAST...AND LOW PRESSURE BEGINS TO APPROACH FROM THE OH VALLEY. && .LONG TERM /SATURDAY THROUGH THURSDAY/... LOW PRESSURE SYSTEM IS PROGGED TO SHIFT IN ON SATURDAY WITH A SECONDARY LOW CENTER PROBABLY PASSING NEARBY OR THROUGH SUNDAY MORNING. INCREASING ISENTROPIC LIFT AND MOISTURE WILL BRING INCREASING POPS THROUGH THE DAY...WITH ALL AREAS LIKELY SEEING RAINFALL BY LATE DAY. PW INCREASES AS WELL...AND WITH A LOW LEVEL JET SHIFTING THROUGH...RAINFALL COULD BE HEAVY AT TIMES LATE IN THE DAY AT LEAST OVER THE SW ZONES...THEN FOR THE ENTIRE CWA DURING SATURDAY EVENING. ENOUGH ELEVATED INSTABILITY AND FORCING WARRANTS ISO THUNDER DURING THIS EVENT. LEANED TOWARD THE COOLER GUIDANCE FOR TEMPS SAT/SAT NIGHT. EXPECTING THE MAIN BATCH OF RAIN TO SHIFT EAST DURING SUNDAY MORNING...SO BY NOON...JUST A CHANCE OF A SHOWER/TSTM REMAINS AS THE TRAILING UPPER TROUGH AXIS APPROACHES. THE THREAT OF RAINFALL LOOKS TO END SUNDAY EVENING AS THE EXITS MOVES EAST AND THE ATMOSPHERE STABILIZES. WEAK HIGH PRESSURE THEN BUILDS IN FOR MONDAY WITH A DRY DAY LIKELY AND HIGH TEMPS CLOSE TO NORMAL. A COLD FRONT APPROACHES ON TUESDAY AND IS FORECAST TO PASS THROUGH TUE NIGHT INTO EARLY WED MORNING. CHANCE SHOWER/TSTM FOCUSED TOWARD THE WESTERN HALF OF THE CWA DURING THE DAY...WITH BEST CHANCES FOR ALL DURING THE NIGHT. OUTSIDE OF A POSSIBLE LINGERING SHOWER WEDNESDAY MORNING FOR THE EASTERN ZONES...WEDNESDAY AND THURSDAY APPEAR TO BE DRY WITH A RETURN TO WEAK HIGH PRESSURE. HIGHS NEAR NORMAL BOTH DAYS. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... LOW PRESSURE APPROACHES OVERNIGHT AND PASSES TO THE SOUTH FRIDAY MORNING. VFR THROUGH THE EVENING...HOWEVER LGT RAIN OR SPRINKLES WILL IMPACT THE CITY ARPTS. MVFR CONDITIONS ARE POSSIBLE AFTER MIDNIGHT IN PERIODS OF STEADIER RAIN. AN IMPROVEMENT TO VFR IS EXPECTED FRIDAY MORNING AFTER THE MORNING PUSH. S/SW WINDS LIGHTEN THIS EVENING BEFORE TURNING TO THE EAST/NE LATE TONIGHT. ESE WINDS FROM ABOUT 18Z THRU THE REMAINDER OF THE TAF PERIOD. ...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: SOME -RA OR SPRINKLES THRU 3Z BUT VFR VIS EXPECTED. KLGA FCSTER COMMENTS: SOME -RA OR SPRINKLES THRU 3Z BUT VFR VIS EXPECTED. KEWR FCSTER COMMENTS: SOME -RA OR SPRINKLES THRU 3Z BUT VFR VIS EXPECTED. WINDS MAY BACK TO AROUND 190 TRUE THRU 3Z. KTEB FCSTER COMMENTS: SOME -RA OR SPRINKLES THRU 3Z BUT VFR VIS EXPECTED. WINDS MAY BACK TO AROUND 190 TRUE THRU 3Z. KHPN FCSTER COMMENTS: SOME -RA OR SPRINKLES THRU 3Z BUT VFR VIS EXPECTED. KISP FCSTER COMMENTS: SOME -RA OR SPRINKLES THRU 3Z BUT VFR VIS EXPECTED. .OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY... .FRIDAY NIGHT-SATURDAY MORNING...VFR. .SATURDAY AFTERNOON-SATURDAY NIGHT...BECOMING MVFR IN THE AFTERNOON...THEN IFR OR LOWER AT NIGHT IN RAIN. E-SE WIND G20-30KT POSSIBLE. .SUNDAY...CHANCE MVFR OR LOWER IN THE MORNING...THEN VFR. SW WINDS G20-25KT POSSIBLE IN AFTERNOON. .SUNDAY NIGHT-TUESDAY...VFR. && .MARINE... MADE MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN OBSERVATIONS AND GUIDANCE. THE FORECAST APPEARS ON TRACK. EASTERLY FLOW WILL INCREASE ON FRI AS LOW PRESSURE PASSES TO THE SOUTH. WINDS AND SEAS MAY APPROACH SCA CRITERIA BUT IT WILL BE A CLOSE CALL...SO NO HEADLINES YET. A STRONG EASTERLY FLOW WILL DEVELOP SATURDAY INTO SATURDAY NIGHT WITH THE APPROACH OF LOW PRESSURE FROM THE WEST. ALL WATERS WILL LIKELY SEE AT LEAST SCA CONDITIONS. FOR THE OCEAN...THERE IS THE POTENTIAL FOR GALE FORCE WINDS MAINLY SATURDAY AFTERNOON AND EVENING AS THE PRESSURE GRADIENT TIGHTENS AND A LOW LEVEL JET PASSES THROUGH. WINDS ARE CURRENTLY FORECAST TO DIMINISH LATE SAT NIGHT INTO SUNDAY MORNING WITH THE THINKING THAT A WEAK LOW CENTER PASSES THROUGH THE WATERS BEFORE SHIFTING EAST OF THE WATERS BY SUNDAY AFTERNOON. WINDS THEN SHIFT SW-W AND PICK UP IN INTENSITY AGAIN. THE OCEAN WATERS WOULD MORE LIKELY CONTINUE TO HAVE SCA CONDITIONS THROUGH THE DAY SUNDAY. SEAS COULD TAKE SOME TIME TO DIMINISH BELOW CRITERIA LEVELS DUE TO A LINGERING SWELL... POSSIBLY NOT DROPPING BELOW 5 FT UNTIL LATE MONDAY NIGHT. THEREAFTER...SUB-SCA CONDITIONS ARE FORECAST FOR ALL WATERS. && .HYDROLOGY... THERE IS THE POTENTIAL FOR 1/10 TO 1/4 INCH OF RAINFALL TONIGHT. SIGNIFICANT WIDESPREAD RAINFALL IS LIKELY FROM LATE SATURDAY INTO SUNDAY MORNING. RAINFALL AMOUNTS BETWEEN 1 AND 2 INCHES ARE FORECAST. LOCALLY HIGHER AMOUNTS ARE POSSIBLE. THIS RAIN IS EXPECTED TO OCCUR IN A RELATIVELY LONG DURATION SO THE CHANCE FOR ANY SIGNIFICANT FLOODING IS LOW. HOWEVER...LOCALLY HEAVY RAINFALL IS POSSIBLE LEADING TO MINOR URBAN AND POOR DRAINAGE FLOODING...PARTICULARLY LATE IN THE DAY SATURDAY AND SATURDAY EVENING. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...MALOIT/GOODMAN/JC NEAR TERM...MALOIT/GOODMAN SHORT TERM...GOODMAN LONG TERM...JC AVIATION...JMC/PW MARINE...MALOIT/GOODMAN/JC HYDROLOGY...MALOIT/GOODMAN/JC
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
250 PM EDT WED JUN 24 2015 ...ISOLD STRONG TO SEVERE STORMS REST OF TODAY... .SHORT TERM...SO FAR TODAY ONLY ISOLD TO SCT CONVECTION OVER NE FL SLOWLY MOVING ENEWD. WITH SBCAPE VALUES OF 2000-3000J...HIGH CONFIDENCE CONVECTION WILL FURTHER INCREASE AND PROPAGATE SLOWLY EWD GIVEN THE PREVAILING SWLY TO WLY FLOW AT ABOUT 5-10 MPH THROUGH ABOUT 12 KFT. WET DOWNBURSTS ARE THE PRIMARY THREAT WITH GUSTS OF 50- 60 MPH POSSIBLE. HAVE PAINTED POPS OF 40-60 PERCENT IN NE FL AND 20- 40 PERCENT IN SE GA. FOR TONIGHT...ISOLD TO SCT CONVECTION WILL BE ONGOING IN THE EVENING WITH BEST COVERAGE IN NE FL. EXPECT CONVECTION TO WIND DOWN LATER TODAY THOUGH SOME ISOLD CELLS...MAINLY SHOWERS WILL BE POSSIBLE WELL AFTER MIDNIGHT. MIN TEMPS IN THE LOWER TO MID 70S EXPECTED. THURSDAY...LOW LEVEL TROUGH REMAINS ENTRENCHED FROM THE CAROLINAS SWWD TO CENTRAL AL AND MS. BEST MOISTURE POSITIONED AGAIN OVER NE FL AND PORTIONS OF SE GA WITH GFS SOUNDING SHOW PWAT OF 2 INCHES. GUIDANCE INDICATING AN ACTIVE DAY...MORE THAN TODAY. FOR NOW SHOWED SOLID 60 PERCENT FOR NE FL AND 40-60 IN SE GA. PRIMARY THREATS REMAIN FREQUENT LIGHTNING AND STRONG DOWNBURST WINDS WITH PULSE STORMS GIVEN WEAK BULK SHEAR VALUES. HIGHS WILL BE A BIT LOWER THAN THE PAST FEW DAYS...PREVAILING IN THE LOWER 90S. UPPER PATTERN TRANSITIONS THURSDAY NIGHT THRU FRIDAY NIGHT FROM UPPER RIDGE SOUTHERN STATES...ZONAL WESTERLIES NORTHERN STATES...TO A PATTERN FEATURING A STRONG WESTERN UPR RIDGE...STRONG E-CTRL UPR TROF BY SAT MORNING. WILL CONTINUE PATTERN OF CHANCE POPS FOR AFTERNOON/EVENING SHOWERS/T-STORMS THRU FRIDAY EVENING. SLIGHTLY LOWER HIGH TEMPS EXPECTED FRIDAY WITH LWR 90S INTERIOR...AROUND 90 EASTERN COUNTIES..UPR 80S COAST. LOW TEMPS LWR-MID 70S INLAND...MID- UPR 70S COAST THURSDAY AND FRIDAY NIGHTS. .LONG TERM /SATURDAY THRU WEDNESDAY/... WEEKEND FEATURES STRONG UPR TROF OVER EASTERN STATES WITH SURFACE COLD FRONT DRIFTING SE OVER SRN GA. ANTICIPATE A DECENT FRONTAL BAND OF SHOWERS/ FEW T-STORMS OVER SRN GA SAT AFTN/NIGHT...AND ACROSS ENTIRE FORECAST AREA SUNDAY. TEMPTED TO GO LIKELY POPS THESE AREAS...BUT CAPPED AT 50 PCT FOR THE MOMENT...LATER SHIFTS MAY INCREASE POPS FURTHER AS CERTAINTY ON THAT LEVEL OF COVERAGE INCREASES. HIGH TEMPS SAT AROUND 90 COAST AND SCTRL GA... LWR 90S ELSEWHERE. FOR SUNDAY...SLIGHTLY LOWER...WITH UPR 80S SRN GA AND COAST...AROUND 90 INLAND NE FL. UPPER PATTERN CHANGES VERY LITTLE THROUGH THE MIDDLE OF NEXT WEEK. FRONTAL MOISTURE BAND SITS OVER NRN FL...WITH DECENT CHANCE POPS EACH DAY ACROSS NE FL...LESSER CHANCES ACRS SE GA. CONSENSUS MODEL GUIDANCE SUGGESTS SOME TEMPS EXPECTED TO BE CLOSE TO NORMAL EARLY NEXT WEEK. && .AVIATION...A FEW TSTMS CAN BE EXPECTED IN AND NEAR THE NE FL TAFS REST OF TODAY WITH MVFR AND GUSTY WINDS. TEMPO GROUPS ADVERTISED GENERALLY FROM 19Z-23Z...BUT THESE MAY NEED TO BE EXTENDED FURTHER INTO THE EVENING BASED ON LATEST HRRR GUIDANCE. HOWEVER...ANTICIPATE CONVECTION WILL BE ON A DOWNWARD TREND AFTER 01Z/02Z WITH VFR PREVAILING THEREAFTER. && .MARINE....SURFACE TROUGH REMAINS OVER SC INTO CTRL GA...WHILE SURFACE HIGH PRESSURE IS CENTERED WELL EAST OF THE WATERS...SETTING UP A S TO SW FLOW PATTERN OVER THE WATERS DURING THE REMAINDER OF THE WEEK. NOCTURNAL SW FLOW SURGES MAY LEAD TO WINDS CLOSE TO EXERCISE CAUTION LEVELS IN THE OFFSHORE COMPONENT EACH NIGHT. A COLD FRONT APPROACHES FROM THE NW DURING THE WEEKEND...WHICH COULD ENHANCE SW FLOW OVER THE WATERS THEN. RIP CURRENTS: LOW RISK THROUGH THURSDAY. && .PRELIMINARY POINT TEMPS/POPS... AMG 74 95 74 91 / 30 50 40 50 SSI 77 91 77 88 / 20 40 30 50 JAX 74 92 74 90 / 40 60 40 50 SGJ 75 89 75 89 / 50 60 40 50 GNV 73 91 73 90 / 50 60 40 50 OCF 74 91 73 90 / 40 60 40 50 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ SHASHY/WOLF/WALSH
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
921 AM EDT WED JUN 24 2015 ...A FEW STRONG TO SEVERE STORMS POSSIBLE THIS AFTERNOON... .UPDATE...SFC RIDGE CONTS WELL S OF THE AREA WITH PREVAILING SW TO W FLOW OVER THE LOCAL REGION. WATER VAPOR AND IR IMAGERY SHOWS A SLOWLY WEAKENING MCS OVER SRN AL WITH SOME DEBRIS MID LEVEL CLOUDS OVER PORTIONS OF NE FL AND SE GA. THESE CLOUDS MAY SLOW HEATING SOMEWHAT BUT SHOULD STILL BE ABLE TO REACH THE LOWER TO MID 90S TODAY. A MID LEVEL TROUGH ACROSS EXTREME SE GA AND NE FL WILL SLOWLY SINK SWD AND COMBINE WITH HIGH MOISTURE (PWATS NEAR 2 INCHES) AND SEA BREEZES TO PRODUCE SCT TO NUMEROUS SHOWERS AND STORMS LATER TODAY. SHORT RANGE GUIDANCE AND VSBY IMAGERY SUGGESTS LIKELY INITIATION OF CONVECTION FROM THE W COAST SEA BREEZE BOUNDARY...WHICH WILL MOVE INTO THE I-75 CORRIDOR BY EARLY AFTN. BEST COVERAGE CONTINUES TO POINT TOWARD NE FL DUE TO BETTER MOISTURE AND DYNAMICS. A MODIFIED RAP SOUNDING SHOWS SBCAPE OF ABOUT 2600 J/KG AND LI OF -6 AND DCAPE SUPPORTIVE OF STRONG TO POSSIBLY SEVERE WET DOWNBURSTS OF 50-60 MPH. WEAK STORM MOTION AND HIGH CAPE VALUES WILL LEAD TO TORRENTIAL DOWNPOURS WITH LOCAL FLOODING ISSUES POSSIBLE. SCT EVENING CONVECTION WILL SLOWLY DISSIPATE LATE TONIGHT. && .AVIATION...VFR PREVAILS THROUGH EARLY AFTN WITH A GOOD CHANCE OF TSTMS AT GNV BY MID AFTN THEN REST OF TAFS BY MID TO LATE AFTN. VCTS FOR MOST TAFS LOOKS GOOD AT THIS POINT WITH TEMPO GROUP FOR GNV 17Z-20Z. MVFR VSBY/CIG WITH STRONG WIND GUSTS LIKELY IN STRONGER STORMS THIS AFTERNOON. && .MARINE...CURRENT FCST ON TRACK WITH OFFSHORE FLOW TURNING MORE S AND SE BY LATE AFTN FROM E COAST SEA BREEZE. SEAS OF 3 FT OR LESS WITH SHOWERS AND STORMS POSSIBLE THIS AFTN. WINDS INCREASE AGAIN TONIGHT TO NEAR SCEC CONDS OFFSHORE. MAIN CONCERNS CENTERED AROUND TSTMS ACTIVITY LATER THIS AFTN OVER THE NEARSHORE WATERS. WILL ADJUST WX FCST A BIT TODAY AND TONIGHT FOR THE MORNING UPDATE. RIP CURRENTS: LOW RISK THROUGH THU OWING TO LIGHT SWELLS AND PREVAILING OFFSHORE FLOW. && .PRELIMINARY POINT TEMPS/POPS... AMG 96 74 95 74 / 20 20 40 40 SSI 90 77 89 78 / 30 30 40 30 JAX 93 75 90 74 / 50 40 50 40 SGJ 90 75 89 75 / 60 50 50 40 GNV 92 73 89 72 / 60 50 50 40 OCF 91 75 89 73 / 50 50 50 40 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ SHASHY/ALLEN
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
401 PM EDT WED JUN 24 2015 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL MUCH OF THIS WEEK WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. A COLD FRONT WILL STALL TO THE NORTH LATE WEEK INTO THE WEEKEND BEFORE FINALLY CROSSING THE AREA SUNDAY. THE FRONT COULD STALL JUST OFFSHORE BEFORE DISSIPATING EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... THROUGH THIS EVENING...SATELLITE PICTURES INDICATE THAT WE/RE FINALLY STARTING TO SEE SOME VERTICAL DEVELOPMENT TO THE CUMULUS CLOUD FIELD...FEEDING OFF THE STEEPENING LAPSE RATES. THERE ARE VARIOUS MESO-SCALE BOUNDARIES SUCH AS OUTFLOW FROM EARLIER MCS/S AND THE EVER PRESENT PIEDMONT TROUGH. BUT THEY`RE OUTSIDE THE CWFA...SO WE NEED TO FOCUS INITIALLY IN OUR AREA ON THE SEA BREEZE INLAND FROM US-17 AND A FEW POPCORN TYPE CELLS THAT FORM DURING THE MAX HEATING OF THE DAY. BUT DUE TO THE WARM MID LEVELS THEY STILL MIGHT HAVE SOME DIFFICULTY IN REACHING ANY APPRECIABLE VERTICAL GROWTH. HOWEVER THERE IS AN ABUNDANCE OF INSTABILITY...WITH SBCAPES ARE 4000-5000 J/KG AND LIFTED INDICES AS COLD AS -6 TO -8C. SO IF BOUNDARY MERGERS GET GOING WE WOULD CERTAINLY SEE AN INCREASE IN BOTH COVERAGE AND UPDRAFT STRENGTH TO THE CONVECTION. WITH DCAPES OF 1000-1200 J/KG AND WINDEX VALUES OF 65 KT THIS WOULD SUPPORT STRONG DOWNBURST WINDS...AIDED BY PRECIP LOADING WITH PWATS CLOSE TO THE 90TH PERCENTILE FOR LATE JUNE. OTHER HAZARDS INCLUDE FREQUENT LIGHTNING STRIKES...VERY HEAVY RAINS DUE TO A STORM MOTION OF ONLY AROUND 5 MPH AND SHOULD ANY TALL STORMS DEVELOP THERE IS ALSO HAIL RISK. PROBABILITY OF SEVERE WEATHER IS STILL TOO LOW TO INCLUDE IN THE HAZARDOUS WEATHER OUTLOOK...MOST NOTABLY DUE TO THE HRRR SHOWING LITTLE IN THE WAY OF SIGNIFICANT CONVECTIVE DEVELOPMENT/ORGANIZATION. WE/LL MAINTAIN A FORECAST OF ISOLATED TO SCATTERED COVERAGE...ESPECIALLY INLAND...ALTHOUGH ANY LOW-END SEVERE POTENTIAL LOOKS TO BE FROM ABOUT 6-9 PM. STORMS WILL GRADUALLY DWINDLE IN BOTH INTENSITY AND AREAL SCOPE...COMING TO AN END ENTIRELY 11 PM-MIDNIGHT. THE HEAT ADVISORY HAS WORKED PERFECTLY WITH MANY SITES HAVING HIT 105-110F...WITH EVEN A FEW LOCATIONS SUCH AS WITHERBEE...GOOSE CREEK AND SYLVANIA REACHING 111-114F. PROVIDED SHOWERS AND T-STORMS DON/T ORGANIZE TOO MUCH TO IMPACT THE TEMP CURVE...THE HEAT ADVISORY WILL CONTINUE THROUGH 7 PM. FOR THE REST OF TONIGHT...THERE ARE HINTS THAT CONVECTION MIGHT GO OVERNIGHT...BUT ODDS FAVOR THAT ANY ACTIVITY AFTER MIDNIGHT WOULD IMPACT THE WATERS OUT NEAR THE GULF STREAM AS NOCTURNAL CINH INCREASES. CONVECTIVE DEBRIS CLOUDINESS WILL DWINDLE AND FADE...LEAVING US WITH MOSTLY CLEAR OR PARTLY CLOUDY SKIES. A WARM SW SYNOPTIC FLOW AND MUCH OF THE AREA NEVER FULLY DECOUPLING WILL PREVENT TEMPS FROM DROPPING ANY LOWER THAN 73-78 INLAND AND 79-82 ON THE COAST AND IN DOWNTOWN CHARLESTON. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... THURSDAY...A LARGE MID LVL RIDGE OF HIGH PRESSURE WILL PERSIST OVER THE AREA. AT THE SFC...THE AREA WILL BE POSITIONED ALONG THE WESTERN PERIPHERY OF ATLANTIC HIGH PRESSURE WHILE A PIEDMONT TROUGH BECOMES SLIGHTLY MORE PRONOUNCED WITH A LOW PRESSURE SYSTEM TRACKING OVER THE MID ATLANTIC STATES. DESPITE LARGE SCALE SINKING MOTION ASSOCIATED WITH HIGH PRESSURE ALOFT...THE PROXIMITY OF THE LOW PRESSURE TROUGH INLAND AND A STALLING COLD FRONT TO OUR NORTH SHOULD SUPPORT A SLIGHT CHANCE TO LOW-END CHANCE OF SHOWERS AND THUNDERSTORMS DURING AFTERNOON/EVENING HOURS. DCAPES IN EXCESS OF 1000 J/KG SUGGEST DAMAGING WIND GUST POTENTIAL WITH A FEW STRONGER THUNDERSTORMS THAT DEVELOP. HOWEVER...THE THREAT OF WIDESPREAD SEVERE WEATHER IS NOT EXPECTED. THE MAIN CONCERN ON THURSDAY WILL BE HEAT/HUMIDITY LEVELS...WHICH WILL BE DEPENDENT ON HOW MUCH CONVECTIVE ACTIVITY OCCURS BEFORE TYPICAL PEAK HEATING HOURS. AT THIS TIME...HIGH TEMPS ARE FORECAST TO REACH THE MID/UPPER 90S...WARMEST INLAND. HOWEVER...STRONG HEATING SHOULD MIX OUT SFC DEWPTS TO AROUND 70 INLAND...WHILE DEWPTS REMAIN IN THE MID 70S NEAR/BEHIND AN INLAND MOVING SEABREEZE. THESE TEMPS AND MOISTURE LEVELS SHOULD SUPPORT HEAT INDEX VALUES NEAR 105 DEGREES FOR A FEW HOURS THURSDAY AFTERNOON AND A HEAT ADVISORY COULD EVENTUALLY BE NEEDED. HOWEVER...SHOULD CLOUD COVER OR PRECIP SHIFT OVER THE AREA EARLY...HEAT INDEX VALUES WILL LIKELY FALL JUST SHORT OF ADVISORY LEVELS. OVERNIGHT LOWS WILL REMAIN MILD...IN THE MID/UPPER 70S INLAND TO LOWER 80S ALONG THE COAST. FRIDAY AND SATURDAY...MODELS INDICATE LOWERING 500 MB HEIGHTS OVER THE AREA THIS WEEKEND AS THE MID LVL RIDGE OF HIGH PRESSURE WEAKENS IN RESPONSE TO A TROUGH OF LOW PRESSURE DIGGING OVER THE MIDWEST/GREAT LAKES REGION. MOISTURE LEVELS ARE EXPECTED TO INCREASE AHEAD OF THE APPROACHING TROUGH...WITH PWATS PROJECTED TO BE NEAR 2.0 INCHES OVER THE SOUTHEASTERN UNITED STATES. THESE MOISTURE LEVELS ALONG WITH INCREASED FORCING FROM A SFC LOW THAT DEVELOPS ALONG A STALLED FRONT TO OUR NORTH...WILL LIKELY RESULT IN AT LEAST CHANCES OF SHOWERS/THUNDERSTORMS ON FRIDAY. BY SATURDAY...GREATER FORCING AND SHEAR WILL LIKELY ARRIVE AS STRONGER WIND FIELDS ROUND THE SOUTHERN PERIPHERY OF THE MID/UPPER LOW CENTERED OVER THE GREAT LAKES REGION. SHOWERS AND THUNDERSTORMS WILL LIKELY OCCUR SATURDAY AFTERNOON...WITH SOME STRONGER THUNDERSTORMS POSSIBLE AHEAD OF A SFC COLD FRONT MAKING WAY INTO THE SOUTHEASTERN UNITED STATES. DAMAGING WIND GUSTS APPEAR TO BE THE MAIN THREAT WITH STRONGER THUNDERSTORMS ON SATURDAY. GIVEN THE AMPLE MOISTURE...SOME THUNDERSTORMS COULD ALSO PRODUCE HEAVY RAINFALL. TEMPS ARE EXPECTED TO BE SLIGHTLY COOLER OVER THE WEEKEND...WITH MAX TEMPS IN THE LOW/MID 90S ON FRIDAY...THEN LOW 90S ON SATURDAY DUE TO AN INCREASE IN CONVECTIVE COVERAGE. GIVEN THE COOLING TREND...HEAT ADVISORIES WILL LIKELY NO LONGER BE NEEDED THIS WEEKEND. OVERNIGHT LOWS SHOULD REMAIN IN THE MID/UPPER 70S.&& .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... BROAD UPPER TROUGH WILL ENCOMPASS THE EASTERN U.S. THROUGH THE LONG TERM PERIOD. A POTENT SHORTWAVE WILL SEND AN AREA OF LOW PRESSURE AND ATTENDANT FRONT THROUGH THE FORECAST AREA ON SUNDAY. GIVEN FORCING FROM UPPER JET...SHORTWAVE ENERGY AND COLD FRONT...IT SHOULD BE A PRETTY ACTIVE DAY ESPECIALLY GIVEN DECENT SHEAR AND DEEP MOISTURE. THE FRONT WILL LIKELY PUSH OFF THE COAST EARLY MONDAY...AND REMAIN STATIONARY OFFSHORE BEFORE DISSIPATING TUESDAY. WEAK HIGH PRESSURE IS EXPECTED TO PREVAIL BY MID WEEK. TEMPERATURES WILL BE AT OR BELOW CLIMO THROUGH THE PERIOD. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... VFR THROUGH 18Z THURSDAY. ISOLATED SHRA/TSRA WILL CONTINUE TO DEVELOP IN THE VICINITY OF KCHS THROUGH 01Z...AND WE WILL AMEND AS NECESSARY SHOULD ANYTHING LOOK TO MORE DIRECTLY AFFECT THE AIRFIELD. WHILE WE CAN/T RULE OUT A TSRA IMPACTING KSAV FROM ABOUT 21-01Z...PROBABILITIES ARE STILL TOO LOW TO INCLUDE WITH THE LATEST TAF SET. EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS ARE POSSIBLE IN AFTERNOON SHOWERS/THUNDERSTORMS...ESPECIALLY LATE THIS WEEKEND. && .MARINE... TONIGHT...IT/S STATUS QUO IN REGARDS TO THE SYNOPTIC PATTERN AND RESULTING CONDITIONS ACROSS THE COASTAL WATERS...WITH SUB-TROPICAL RIDGING TO THE SOUTH/SE...MESO-HIGH PRESSURE IN THE NE GULF OF MEXICO AND A NE-SW ALIGNED TROUGH INLAND. ADEQUATE MIXING OF 20-25 KT GEOSTROPHIC WINDS AND A MODEST GRADIENT WILL ALLOW FOR SOUTH/SW WINDS UP TO 15 OR 20 KT WITH OCCASIONAL HIGHER GUSTS. WAVES OF 1-2 FT WILL BE COMMON IN CHARLESTON HARBOR...WITH 2-4 FT IN THE OPEN ATLANTIC...HIGHEST ON AMZ350-374. THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL DOMINATE THE COASTAL WATERS WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND THROUGH LATE WEEK. A COLD FRONT IS EXPECTED TO SHIFT OVER THE WATERS LATE WEEKEND...BEFORE EVENTUALLY STALLING/DISSIPATING EARLY NEXT WEEK. A TIGHTENED PRESSURE GRADIENT WILL KEEP WINDS FAIRLY ELEVATED THROUGH THE PERIOD. NOCTURNAL JETTING AND AFTERNOON SEA BREEZE CIRCULATIONS WILL RESULT IN SOUTH/SOUTHWEST WINDS PEAKING AROUND 15- 20 KTS AT TIMES...ESPECIALLY ACROSS THE CHARLESTON COUNTY COASTAL WATERS. WIND GUSTS COULD REACH SMALL CRAFT ADVISORY CRITERIA SATURDAY AFTERNOON OR NIGHT...THEN SLOWLY IMPROVE EARLY NEXT WEE, SEAS WILL MAINLY BE 2-4 FEET...BUT COULD REACH 6 FEET IN THE OUTER PORTIONS OF THE WATERS THIS WEEKEND. && .CLIMATE... RECORD HIGH MINIMUMS FOR JUNE 24TH... KCHS...79 SET IN 1998. KCXM...85 SET IN 1998. KSAV...80 SET IN 1914. RECORD HIGH MINIMUMS FOR JUNE 25TH... KCHS...79 SET IN 2010. KCXM...83 SET IN 1998. KSAV...80 SET IN 1914. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR GAZ087-088- 099>101-114>119-137>141. SC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR SCZ040-042>045- 047>052. MARINE...NONE. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE... CLIMATE...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
138 PM EDT WED JUN 24 2015 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL MUCH OF THIS WEEK WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. A COLD FRONT WILL STALL TO THE NORTH LATE WEEK INTO THE WEEKEND BEFORE FINALLY CROSSING THE AREA LATE SUNDAY. THE FRONT MAY STALL JUST OFFSHORE BEFORE DISSIPATING EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... FOR THE AFTERNOON UPDATE WE HAVE MADE MINOR CHANGES TO HOURLY/MAX TEMPS...POPS AND SKY COVER...BUT NOTHING MAJOR. CONVECTION HAS BEEN SLOW IN DEVELOPING...WITH ONLY FEW-SCATTERED CUMULUS FORMATION. WE/LL SOON HIT OUR CONVECTIVE TEMP IN THE MID 90S...SO THE GENERAL TREND OF THE FORECAST IS STILL ON TRACK. AFTER OUR BRIEF RESPITE FROM THE EXTREME HEAT AND HUMIDITY COMBINATION YESTERDAY...IT/S BACK TO THE OPPRESSIVE AND STICKY CONDITIONS THAT WE HAVE SEEN MUCH OF THE PAST 2 WEEKS. TEMPS ARE RUNNING ON AVERAGE ABOUT 2-3F WARMER THAN 24 HOURS AGO...AND WITH 850 MB TEMPS OF 19-20C AND PLENTY OF INSOLATION...WE/RE ON OUR WAY TO THE MID AND UPPER 90S INLAND FROM US-17. A FEW SPOTS MIGHT EVEN PEAK AT THE CENTURY MARK. DEW POINTS WILL MIX OUT A BIT INLAND...BUT WILL POOL BEHIND THE SEA BREEZE...WHICH SUPPORTS MOST HEAT INDICES AS HIGH AS 105-109F...BUT A FEW SPOTS OF THE COASTAL CORRIDOR WILL MAX OUT AT 110-114F AROUND THE TIME OF THE SEA BREEZE PASSAGE. OUR HEAT ADVISORY WILL OBVIOUSLY REMAIN ACTIVE. THE FORECAST FOR HOW CONVECTION WILL PAN OUT IS FAR FROM CERTAIN GIVEN A WIDE DISPARITY IN VARIOUS MODELS. WE STILL HAVE A SUBTLE WEAKNESS IN THE RIDGING ALOFT...BUT THAT LOOKS TO BE JUST OFF THE COAST. THERE WILL BE VARIOUS MESO-SCALE BOUNDARIES SUCH AS OUTFLOW FROM EARLIER MCS THAT MOVED OFF THE MID-ATLANTIC AND ANOTHER FROM ALABAMA. THERE IS ALSO THE EVER PRESENT PIEDMONT TROUGH AND THE SEA BREEZE BOUNDARY. THESE FACTORS SHOULD PROVIDE THE NECESSARY INITIATION...BUT THERE IS STILL A STRONG 3-5C CAP AND UNFAVORABLE MID LEVEL LAPSE RATES WITH WARM 500 MB TEMPS...IMPLYING THAT STORMS MAY HAVE A DIFFICULT TIME IN ATTAINING MUCH VERTICAL GROWTH. ON THE FAVORABLE SIDE OUR LOW LEVEL LAPSE RATES ARE FAVORABLE AND THERE IS PLENTY OF INSTABILITY WITH SBCAPES FORECAST TO REACH 4000-4500 J/KG AND LIFTED INDEX OF -6 TO -8C. LOOK FOR CONVECTION TO GET GOING AROUND 3-4 PM AS WE HIT OUR CONVECTIVE TEMP IN THE MID 90S. FOR THE MOMENT A PULSE TYPE ENVIRONMENT SEEMS A MORE LIKELY CONVECTIVE MODE RATHER THAN MULTI-CELLULAR...BUT IF BOUNDARY INTERACTIONS AND MERGERS TAKE PLACE THAT COULD CHANGE. WE/LL MAINTAIN A PROBABILITY FORECAST OF 20-30 PERCENT...HIGHEST INLAND AND MAINTAIN A CLOSE WATCH ON MESO-SCALE TRENDS TO SEE IF WE NEED TO RAISE POPS. DCAPES OF 1000-1200 J/KG AND WINDEX VALUES OF 65 KT WOULD SUPPORT STRONG DOWNBURST WINDS...AIDED BY PRECIP LOADING WITH PWATS CLOSE TO THE 90TH PERCENTILE FOR LATE JUNE. OTHER HAZARDS INCLUDE FREQUENT LIGHTNING STRIKES...VERY HEAVY RAINS DUE TO A STORM MOTION OF ONLY AROUND 5 MPH AND SHOULD ANY TALL STORMS DEVELOP THERE IS ALSO HAIL RISK. PROBABILITY OF SEVERE WEATHER IS STILL TOO LOW TO INCLUDE IN THE HAZARDOUS WEATHER OUTLOOK...MOST NOTABLY DUE TO THE HRRR SHOWING LITTLE IN THE WAY OF CONVECTIVE ORGANIZATION. CONDITIONS SHOULD BE MAINLY QUIET TONIGHT WITH PARTLY CLOUDY SKIES AND LOWS A BIT WARMER THAN WEDNESDAY MORNING...ESPECIALLY IF TSTMS COVERAGE IS LOWER END TODAY. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... THURSDAY...PERSISTENT MID LEVEL RIDGE WILL HOLD FAIRLY STRONG FOR ONE MORE DAY...ALTHOUGH SUBTLE WEAKENING WILL BEGIN TO OCCUR. THE SURFACE PATTERN WILL CONTINUE TO BE FAIRLY STATIC AS THE AREA REMAINS ON THE WESTERN PERIPHERY OF ATLANTIC HIGH PRESSURE WITH A PIEDMONT TROUGH SITUATED INLAND. HIGH TEMPERATURES IN THE MID/UPPER 90S AWAY FROM THE COAST WILL COMBINE WITH MODERATE HUMIDITY LEVELS TO PRODUCE HEAT INDICES OF 105-108 IN THE AFTERNOON. THUS A HEAT ADVISORY WILL LIKELY BE NEEDED. LARGE SCALE FORCING WILL LARGELY BE MISSING HOWEVER CONVECTION WILL DEVELOP AS A RESULT OF SEA BREEZE AND/OR CONVERGENCE ALONG SURFACE TROUGH. FORECAST SURFACE BASED CAPE NEAR 3000 J/KG MAY SUPPORT A FEW STRONGER POSSIBLY SEVERE STORMS...WITH GUSTY WINDS THE PRIMARY THREAT GIVEN DCAPE VALUES IN EXCESS OF 1000 J/KG. THURSDAY NIGHT...SURFACE LOW PRESSURE WILL CROSS THE MID-ATLANTIC STATES ABSORBING THE PIEDMONT TROUGH. AN ATTENDANT FRONT WILL STALL NORTH OF THE AREA. LOWS WILL BE QUITE MILD RANGING FROM THE MID 70S INLAND TO AROUND 80 ALONG THE COAST. FRIDAY...AN AREA OF LOW PRESSURE WILL DEVELOP OVER THE CAROLINAS ALONG THE AFOREMENTIONED STALLED FRONT. DEEP MOISTURE AND PROXIMITY TO BOUNDARY WILL ALLOW FOR HIGHER COVERAGE OF SHOWERS AND THUNDERSTORMS. FORECAST CURRENTLY FEATURES HIGH CHANCE POPS OVER MUCH OF THE AREA DURING PEAK HEATING HOURS. A FEW STRONGER STORMS WILL BE POSSIBLE ESPECIALLY IN THE NORTHERN ZONES WHERE INSTABILITY AND MID LEVEL ENVIRONMENT IS MORE FAVORABLE...WITH GUSTY WINDS PRIMARY THREAT. FORECAST HEAT INDICES MAY BRIEFLY REACH THE LOCAL HEAT ADVISORY CRITERIA OF 105 IN THE AFTERNOON WITH HIGH TEMPERATURES IN THE LOW/MID 90S...HOWEVER DURATION AND AREAL EXTENT WILL BE MARGINAL AT BEST AND GIVEN EXPECTED CONVECTION...THINK A HEAT ADVISORY WILL LIKELY NOT BE NEEDED. CONVECTION MAY LINGER INTO THE OVERNIGHT PERIOD...WITH FOCUS SHIFTING MORE TO THE COASTAL WATERS. LOWS WILL AGAIN BE IN THE MID TO UPPER 70S. SATURDAY...THE UPPER LEVEL PATTERN WILL BECOME MUCH MORE AMPLIFIED AS DEEPENING TROUGH AND ASSOCIATED VORT MAX DIGS INTO THE GREAT LAKES REGION. THIS WILL HELP SEND ANOTHER AREA OF LOW PRESSURE TOWARDS EAST COAST WHICH WILL EVENTUALLY ENGULF THE STATIONARY FRONT/LOW. BETTER UPPER SUPPORT...DEEP MOISTURE AND VARIOUS SURFACE BOUNDARIES WILL ALLOW FOR A FAIRLY ACTIVE DAY WITH STRONGER STORMS POSSIBLE GIVEN DECENT SHEAR AND FORECAST INSTABILITY. HIGH TEMPERATURES WILL MAINLY BE IN THE LOW 90S. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... BROAD UPPER TROUGH WILL ENCOMPASS THE EASTERN U.S. THROUGH THE LONG TERM PERIOD. A POTENT SHORTWAVE WILL SEND AN AREA OF LOW PRESSURE AND ATTENDANT FRONT THROUGH THE FORECAST AREA ON SUNDAY. GIVEN FORCING FROM UPPER JET...SHORTWAVE ENERGY AND COLD FRONT...IT SHOULD BE A PRETTY ACTIVE DAY ESPECIALLY GIVEN DECENT SHEAR AND DEEP MOISTURE. THE FRONT WILL LIKELY PUSH OFF THE COAST EARLY MONDAY...AND REMAIN STATIONARY OFFSHORE BEFORE DISSIPATING TUESDAY. WEAK HIGH PRESSURE IS EXPECTED TO PREVAIL BY MID WEEK. TEMPERATURES WILL BE AT OR BELOW CLIMO THROUGH THE PERIOD. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... VFR THROUGH 18Z THURSDAY. WHILE WE CAN/T RULE OUT A TSRA IMPACTING EITHER TERMINAL FROM ABOUT 20Z-01Z...PROBABILITIES ARE STILL TOO LOW TO INCLUDE WITH THE LATEST TAF SET. EXTENDED AVIATION OUTLOOK...BRIEF FLIGHT RESTRICTIONS POSSIBLE IN AFTERNOON SHOWERS/THUNDERSTORMS...ESPECIALLY THIS WEEKEND. && .MARINE... THE COASTAL WATERS SYNOPTIC PATTERN IS NOT CHANGING MUCH AND MARINERS FAMILIAR WITH THE SUMMER PATTERNS WILL NOT GET ANY BIG SURPRISES THROUGH TONIGHT. SOUTH/SW SEA BREEZE CIRCULATIONS THIS AFTERNOON AND SW NOCTURNAL SURGES WILL PUSH SPEEDS INTO THE 15-20 KT RANGE WITH SOME HIGHER GUSTS AT FAVORED AREAS SUCH AS THE CHARLESTON LAND/SEA INTERFACE. SEAS WILL BE 2-4 FT ON AVERAGE...HIGHEST WELL OFFSHORE. WAVES IN THE HARBOR WILL BE 1 TO 2 FT THROUGH THIS EVENING. THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL PREVAIL OVER THE COASTAL WATERS WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND THROUGH THE REMAINDER OF THE WEEK. A COLD FRONT IS EXPECTED TO APPROACH THE WATERS OVER THE WEEKEND AND EVENTUALLY STALL AND DISSIPATE EARLY NEXT WEEK. TIGHTENED PRESSURE GRADIENT WILL KEEP WINDS FAIRLY ELEVATED THROUGH THE PERIOD. NOCTURNAL JETTING AND AFTERNOON SEA BREEZE CIRCULATIONS WILL RESULT IN SOUTH/SOUTHWEST WINDS PEAKING AROUND 15-20 KT...ESPECIALLY ACROSS THE CHARLESTON COUNTY COASTAL WATERS. GUSTS MAY REACH NEAR SMALL CRAFT ADVISORY CRITERIA OF 25 KT AT TIMES...AND HEADLINES MAY NEED TO BE CONSIDERED. SEAS WILL MAINLY BE 2-4 FEET...BUT MAY REACH 5-6 FEET IN THE OUTER PORTIONS OF THE WATERS DURING SURGES. && .CLIMATE... RECORD HIGH MINIMUMS FOR JUNE 24TH... KCHS...79 SET IN 1998. KCXM...85 SET IN 1998. KSAV...80 SET IN 1914. RECORD HIGH MINIMUMS FOR JUNE 25TH... KCHS...79 SET IN 2010. KCXM...83 SET IN 1998. KSAV...80 SET IN 1914. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR GAZ087-088- 099>101-114>119-137>141. SC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR SCZ040-042>045- 047>052. MARINE...NONE. && $$ SYNOPSIS... NEAR TERM... SHORT TERM...ECT LONG TERM...ECT AVIATION... MARINE... CLIMATE...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1139 AM EDT WED JUN 24 2015 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL MUCH OF THIS WEEK WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. A COLD FRONT WILL STALL TO THE NORTH LATE WEEK INTO THE WEEKEND BEFORE FINALLY CROSSING THE AREA LATE SUNDAY. THE FRONT MAY STALL JUST OFFSHORE BEFORE DISSIPATING EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... FOR THE MIDDAY UPDATE WE HAVE MADE MINOR CHANGES TO HOURLY TEMPS...POPS AND SKY COVER...BUT NOTHING MAJOR. SATELLITE IMAGES AND SURFACE ANALYSIS SHOWING AN OUTFLOW BOUNDARY FROM THE PREVIOUS MCS MOVING SOUTHWARD FROM FAR SE NC THROUGH THE PEE-DEE AND UPSTATE OF SC INTO NORTHERN GA. THIS IS WHERE CONVECTION WILL LIKELY START POPPING FIRST. AFTER OUR BRIEF RESPITE FROM THE EXTREME HEAT AND HUMIDITY COMBINATION YESTERDAY...IT/S BACK TO THE OPPRESSIVE AND STICKY CONDITIONS THAT WE HAVE SEEN MUCH OF THE PAST 2 WEEKS. TEMPS ARE RUNNING ON AVERAGE ABOUT 2-3F WARMER THAN 24 HOURS AGO...AND WITH 850 MB TEMPS OF 19-20C AND PLENTY OF INSOLATION...WE/RE ON OUR WAY TO THE MID AND UPPER 90S INLAND FROM US-17. A FEW SPOTS MIGHT EVEN PEAK AT THE CENTURY MARK. DEW POINTS WILL MIX OUT A BIT INLAND...BUT WILL POOL BEHIND THE SEA BREEZE...WHICH SUPPORTS MOST HEAT INDICES AS HIGH AS 105-109F...BUT A FEW SPOTS OF THE COASTAL CORRIDOR WILL MAX OUT AT 110-112F AROUND THE TIME OF THE SEA BREEZE PASSAGE. OUR HEAT ADVISORY WILL OBVIOUSLY REMAIN ACTIVE. THE FORECAST FOR HOW CONVECTION WILL PAN OUT IS FAR FROM CERTAIN GIVEN A WIDE DISPARITY IN VARIOUS MODELS. WE STILL HAVE A SUBTLE WEAKNESS IN THE RIDGING ALOFT...BUT THAT LOOKS TO BE JUST OFF THE COAST. THERE WILL BE VARIOUS MESO-SCALE BOUNDARIES SUCH S OUTFLOW FROM EARLIER MCS THAT MOVED OFF THE MID-ATLANTIC AND ANOTHER FROM ALABAMA. THERE IS ALSO THE EVER PRESENT PIEDMONT TROUGH AND THE SEA BREEZE BOUNDARY. THESE FACTORS SHOULD PROVIDE THE NECESSARY INITIATION...BUT THERE IS STILL A STRONG 3-5C CAP AND UNFAVORABLE MID LEVEL LAPSE RATES WITH WARM 500 MB TEMPS...IMPLYING THAT STORMS MAY HAVE A DIFFICULT TIME IN ATTAINING MUCH VERTICAL GROWTH. ON THE FAVORABLE SIDE OUR LOW LEVEL LAPSE RATES ARE FAVORABLE AND THERE IS PLENTY OF INSTABILITY WITH SBCAPES FORECAST TO REACH 4000-4500 J/KG AND LIFTED INDEX OF -6 TO -8C. LOOK FOR CONVECTION TO GET GOING AROUND 1-2 PM AS WE HIT OUR CONVECTIVE TEMP IN THE MID 90S. FOR THE MOMENT A PULSE TYPE ENVIRONMENT SEEMS A MORE LIKELY CONVECTIVE MODE RATHER THAN MULTI-CELLULAR...BUT IF BOUNDARY INTERACTIONS AND MERGERS TAKE PLACE THAT COULD CHANGE. WE/LL MAINTAIN A PROBABILITY FORECAST OF 20-30 PERCENT...HIGHEST INLAND AND MAINTAIN A CLOSE WATCH ON MESO-SCALE TRENDS TO SEE IF WE NEED TO RAISE POPS. DCAPES OF 1000-1200 J/KG AND WINDEX VALUES OF 65 KT WOULD SUPPORT STRONG DOWNBURST WINDS...AIDED BY PRECIP LOADING WITH PWATS CLOSE TO THE 90TH PERCENTILE FOR LATE JUNE. OTHER HAZARDS INCLUDE FREQUENT LIGHTNING STRIKES...VERY HEAVY RAINS DUE TO A STORM MOTION OF ONLY AROUND 5 MPH AND SHOULD ANY TALL STORMS DEVELOP THERE IS ALSO HAIL RISK. PROBABILITY OF SEVERE WEATHER IS STILL TOO LOW TO INCLUDE IN THE HAZARDOUS WEATHER OUTLOOK...MOST NOTABLY DUE TO THE HRRR SHOWING LITTLE IN THE WAY OF CONVECTIVE ORGANIZATION. CONDITIONS SHOULD BE MAINLY QUIET TONIGHT WITH PARTLY CLOUDY SKIES AND LOWS A BIT WARMER THAN WEDNESDAY MORNING...ESPECIALLY IF TSTMS COVERAGE IS LOWER END TODAY. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... THURSDAY...PERSISTENT MID LEVEL RIDGE WILL HOLD FAIRLY STRONG FOR ONE MORE DAY...ALTHOUGH SUBTLE WEAKENING WILL BEGIN TO OCCUR. THE SURFACE PATTERN WILL CONTINUE TO BE FAIRLY STATIC AS THE AREA REMAINS ON THE WESTERN PERIPHERY OF ATLANTIC HIGH PRESSURE WITH A PIEDMONT TROUGH SITUATED INLAND. HIGH TEMPERATURES IN THE MID/UPPER 90S AWAY FROM THE COAST WILL COMBINE WITH MODERATE HUMIDITY LEVELS TO PRODUCE HEAT INDICES OF 105-108 IN THE AFTERNOON. THUS A HEAT ADVISORY WILL LIKELY BE NEEDED. LARGE SCALE FORCING WILL LARGELY BE MISSING HOWEVER CONVECTION WILL DEVELOP AS A RESULT OF SEA BREEZE AND/OR CONVERGENCE ALONG SURFACE TROUGH. FORECAST SURFACE BASED CAPE NEAR 3000 J/KG MAY SUPPORT A FEW STRONGER POSSIBLY SEVERE STORMS...WITH GUSTY WINDS THE PRIMARY THREAT GIVEN DCAPE VALUES IN EXCESS OF 1000 J/KG. THURSDAY NIGHT...SURFACE LOW PRESSURE WILL CROSS THE MID-ATLANTIC STATES ABSORBING THE PIEDMONT TROUGH. AN ATTENDANT FRONT WILL STALL NORTH OF THE AREA. LOWS WILL BE QUITE MILD RANGING FROM THE MID 70S INLAND TO AROUND 80 ALONG THE COAST. FRIDAY...AN AREA OF LOW PRESSURE WILL DEVELOP OVER THE CAROLINAS ALONG THE AFOREMENTIONED STALLED FRONT. DEEP MOISTURE AND PROXIMITY TO BOUNDARY WILL ALLOW FOR HIGHER COVERAGE OF SHOWERS AND THUNDERSTORMS. FORECAST CURRENTLY FEATURES HIGH CHANCE POPS OVER MUCH OF THE AREA DURING PEAK HEATING HOURS. A FEW STRONGER STORMS WILL BE POSSIBLE ESPECIALLY IN THE NORTHERN ZONES WHERE INSTABILITY AND MID LEVEL ENVIRONMENT IS MORE FAVORABLE...WITH GUSTY WINDS PRIMARY THREAT. FORECAST HEAT INDICES MAY BRIEFLY REACH THE LOCAL HEAT ADVISORY CRITERIA OF 105 IN THE AFTERNOON WITH HIGH TEMPERATURES IN THE LOW/MID 90S...HOWEVER DURATION AND AREAL EXTENT WILL BE MARGINAL AT BEST AND GIVEN EXPECTED CONVECTION...THINK A HEAT ADVISORY WILL LIKELY NOT BE NEEDED. CONVECTION MAY LINGER INTO THE OVERNIGHT PERIOD...WITH FOCUS SHIFTING MORE TO THE COASTAL WATERS. LOWS WILL AGAIN BE IN THE MID TO UPPER 70S. SATURDAY...THE UPPER LEVEL PATTERN WILL BECOME MUCH MORE AMPLIFIED AS DEEPENING TROUGH AND ASSOCIATED VORT MAX DIGS INTO THE GREAT LAKES REGION. THIS WILL HELP SEND ANOTHER AREA OF LOW PRESSURE TOWARDS EAST COAST WHICH WILL EVENTUALLY ENGULF THE STATIONARY FRONT/LOW. BETTER UPPER SUPPORT...DEEP MOISTURE AND VARIOUS SURFACE BOUNDARIES WILL ALLOW FOR A FAIRLY ACTIVE DAY WITH STRONGER STORMS POSSIBLE GIVEN DECENT SHEAR AND FORECAST INSTABILITY. HIGH TEMPERATURES WILL MAINLY BE IN THE LOW 90S. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... BROAD UPPER TROUGH WILL ENCOMPASS THE EASTERN U.S. THROUGH THE LONG TERM PERIOD. A POTENT SHORTWAVE WILL SEND AN AREA OF LOW PRESSURE AND ATTENDANT FRONT THROUGH THE FORECAST AREA ON SUNDAY. GIVEN FORCING FROM UPPER JET...SHORTWAVE ENERGY AND COLD FRONT...IT SHOULD BE A PRETTY ACTIVE DAY ESPECIALLY GIVEN DECENT SHEAR AND DEEP MOISTURE. THE FRONT WILL LIKELY PUSH OFF THE COAST EARLY MONDAY...AND REMAIN STATIONARY OFFSHORE BEFORE DISSIPATING TUESDAY. WEAK HIGH PRESSURE IS EXPECTED TO PREVAIL BY MID WEEK. TEMPERATURES WILL BE AT OR BELOW CLIMO THROUGH THE PERIOD. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... VFR THROUGH 12Z THURSDAY. POTENTIAL FOR AFTERNOON AND EVENING SHOWERS AND TSTMS TODAY IS TOO LOW FOR ANY MENTIONS IN THE CURRENT TAF CYCLE AT THIS TIME...ESPECIALLY WITH UNCERTAINTIES WITH TIMING AND COVERAGE. EXTENDED AVIATION OUTLOOK...BRIEF FLIGHT RESTRICTIONS POSSIBLE IN AFTERNOON SHOWERS/THUNDERSTORMS...ESPECIALLY THIS WEEKEND. && .MARINE... THE COASTAL WATERS SYNOPTIC PATTERN IS NOT CHANGING MUCH AND MARINERS FAMILIAR WITH THE SUMMER PATTERNS WILL NOT GET ANY BIG SURPRISES THROUGH TONIGHT. SOUTH/SW SEA BREEZE CIRCULATIONS THIS AFTERNOON AND SW NOCTURNAL SURGES WILL PUSH SPEEDS INTO THE 15-20 KT RANGE WITH SOME HIGHER GUSTS AT FAVORED AREAS SUCH AS THE CHARLESTON LAND/SEA INTERFACE. SEAS WILL BE 2-4 FT ON AVERAGE...HIGHEST WELL OFFSHORE. WAVES IN THE HARBOR WILL BE 1 TO 2 FT THROUGH THIS EVENING. THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL PREVAIL OVER THE COASTAL WATERS WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND THROUGH THE REMAINDER OF THE WEEK. A COLD FRONT IS EXPECTED TO APPROACH THE WATERS OVER THE WEEKEND AND EVENTUALLY STALL AND DISSIPATE EARLY NEXT WEEK. TIGHTENED PRESSURE GRADIENT WILL KEEP WINDS FAIRLY ELEVATED THROUGH THE PERIOD. NOCTURNAL JETTING AND AFTERNOON SEA BREEZE CIRCULATIONS WILL RESULT IN SOUTH/SOUTHWEST WINDS PEAKING AROUND 15-20 KT...ESPECIALLY ACROSS THE CHARLESTON COUNTY COASTAL WATERS. GUSTS MAY REACH NEAR SMALL CRAFT ADVISORY CRITERIA OF 25 KT AT TIMES...AND HEADLINES MAY NEED TO BE CONSIDERED. SEAS WILL MAINLY BE 2-4 FEET...BUT MAY REACH 5-6 FEET IN THE OUTER PORTIONS OF THE WATERS DURING SURGES. && .CLIMATE... RECORD HIGH MINIMUMS FOR JUNE 24TH... KCHS...79 SET IN 1998. KCXM...85 SET IN 1998. KSAV...80 SET IN 1914. RECORD HIGH MINIMUMS FOR JUNE 25TH... KCHS...79 SET IN 2010. KCXM...83 SET IN 1998. KSAV...80 SET IN 1914. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR GAZ087-088- 099>101-114>119-137>141. SC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR SCZ040-042>045- 047>052. MARINE...NONE. && $$ SYNOPSIS... NEAR TERM... SHORT TERM...ECT LONG TERM...ECT AVIATION... MARINE... CLIMATE...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1022 AM EDT WED JUN 24 2015 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL MUCH OF THIS WEEK WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. A COLD FRONT WILL STALL TO THE NORTH LATE WEEK INTO THE WEEKEND BEFORE FINALLY CROSSING THE AREA LATE SUNDAY. THE FRONT MAY STALL JUST OFFSHORE BEFORE DISSIPATING EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AFTER OUR BRIEF RESPITE FROM THE EXTREME HEAT AND HUMIDITY COMBINATION YESTERDAY...IT/S BACK TO THE OPPRESSIVE AND STICKY CONDITIONS THAT WE HAVE SEEN MUCH OF THE PAST 2 WEEKS. TEMPS ARE RUNNING ON AVERAGE ABOUT 2-3F WARMER THAN 24 HOURS AGO...AND WITH 850 MB TEMPS OF 19-20C AND PLENTY OF INSOLATION...WE/RE ON OUR WAY TO THE MID AND UPPER 90S INLAND FROM US-17. A FEW SPOTS MIGHT EVEN PEAK AT THE CENTURY MARK. DEW POINTS WILL MIX OUT A BIT INLAND...BUT WILL POOL BEHIND THE SEA BREEZE...WHICH SUPPORTS MOST HEAT INDICES AS HIGH AS 105-109F...BUT A FEW SPOTS OF THE COASTAL CORRIDOR WILL MAX OUT AT 110-112F AROUND THE TIME OF THE SEA BREEZE PASSAGE. OUR HEAT ADVISORY WILL OBVIOUSLY REMAIN ACTIVE. THE FORECAST FOR HOW CONVECTION WILL PAN OUT IS FAR FROM CERTAIN GIVEN A WIDE DISPARITY IN VARIOUS MODELS. WE STILL HAVE A SUBTLE WEAKNESS IN THE RIDGING ALOFT...BUT THAT LOOKS TO BE JUST OFF THE COAST. THERE WILL BE VARIOUS MESO-SCALE BOUNDARIES SUCH S OUTFLOW FROM EARLIER MCS THAT MOVED OFF THE MID-ATLANTIC AND ANOTHER FROM ALABAMA. THERE IS ALSO THE EVER PRESENT PIEDMONT TROUGH AND THE SEA BREEZE BOUNDARY. THESE FACTORS SHOULD PROVIDE THE NECESSARY INITIATION...BUT THERE IS STILL A STRONG 3-5C CAP AND UNFAVORABLE MID LEVEL LAPSE RATES WITH WARM 500 MB TEMPS...IMPLYING THAT STORMS MAY HAVE A DIFFICULT TIME IN ATTAINING MUCH VERTICAL GROWTH. ON THE FAVORABLE SIDE OUR LOW LEVEL LAPSE RATES ARE FAVORABLE AND THERE IS PLENTY OF INSTABILITY WITH SBCAPES FORECAST TO REACH 4000-4500 J/KG AND LIFTED INDEX OF -6 TO -8C. LOOK FOR CONVECTION TO GET GOING AROUND 1-2 PM AS WE HIT OUR CONVECTIVE TEMP IN THE MID 90S. FOR THE MOMENT A PULSE TYPE ENVIRONMENT SEEMS A MORE LIKELY CONVECTIVE MODE RATHER THAN MULTI-CELLULAR...BUT IF BOUNDARY INTERACTIONS AND MERGERS TAKE PLACE THAT COULD CHANGE. WE/LL MAINTAIN A PROBABILITY FORECAST OF 20-30 PERCENT...HIGHEST INLAND AND MAINTAIN A CLOSE WATCH ON MESO-SCALE TRENDS TO SEE IF WE NEED TO RAISE POPS. DCAPES OF 1000-1200 J/KG AND WINDEX VALUES OF 65 KT WOULD SUPPORT STRONG DOWNBURST WINDS...AIDED BY PRECIP LOADING WITH PWATS CLOSE TO THE 90TH PERCENTILE FOR LATE JUNE. OTHER HAZARDS INCLUDE FREQUENT LIGHTNING STRIKES...VERY HEAVY RAINS DUE TO A STORM MOTION OF ONLY AROUND 5 MPH AND SHOULD ANY TALL STORMS DEVELOP THERE IS ALSO HAIL RISK. PROBABILITY OF SEVERE WEATHER IS STILL TOO LOW TO INCLUDE IN THE HAZARDOUS WEATHER OUTLOOK...MOST NOTABLY DUE TO THE HRRR SHOWING LITTLE IN THE WAY OF CONVECTIVE ORGANIZATION. CONDITIONS SHOULD BE MAINLY QUIET TONIGHT WITH PARTLY CLOUDY SKIES AND LOWS A BIT WARMER THAN WEDNESDAY MORNING...ESPECIALLY IF TSTMS COVERAGE IS LOWER END TODAY. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... THURSDAY...PERSISTENT MID LEVEL RIDGE WILL HOLD FAIRLY STRONG FOR ONE MORE DAY...ALTHOUGH SUBTLE WEAKENING WILL BEGIN TO OCCUR. THE SURFACE PATTERN WILL CONTINUE TO BE FAIRLY STATIC AS THE AREA REMAINS ON THE WESTERN PERIPHERY OF ATLANTIC HIGH PRESSURE WITH A PIEDMONT TROUGH SITUATED INLAND. HIGH TEMPERATURES IN THE MID/UPPER 90S AWAY FROM THE COAST WILL COMBINE WITH MODERATE HUMIDITY LEVELS TO PRODUCE HEAT INDICES OF 105-108 IN THE AFTERNOON. THUS A HEAT ADVISORY WILL LIKELY BE NEEDED. LARGE SCALE FORCING WILL LARGELY BE MISSING HOWEVER CONVECTION WILL DEVELOP AS A RESULT OF SEA BREEZE AND/OR CONVERGENCE ALONG SURFACE TROUGH. FORECAST SURFACE BASED CAPE NEAR 3000 J/KG MAY SUPPORT A FEW STRONGER POSSIBLY SEVERE STORMS...WITH GUSTY WINDS THE PRIMARY THREAT GIVEN DCAPE VALUES IN EXCESS OF 1000 J/KG. THURSDAY NIGHT...SURFACE LOW PRESSURE WILL CROSS THE MID-ATLANTIC STATES ABSORBING THE PIEDMONT TROUGH. AN ATTENDANT FRONT WILL STALL NORTH OF THE AREA. LOWS WILL BE QUITE MILD RANGING FROM THE MID 70S INLAND TO AROUND 80 ALONG THE COAST. FRIDAY...AN AREA OF LOW PRESSURE WILL DEVELOP OVER THE CAROLINAS ALONG THE AFOREMENTIONED STALLED FRONT. DEEP MOISTURE AND PROXIMITY TO BOUNDARY WILL ALLOW FOR HIGHER COVERAGE OF SHOWERS AND THUNDERSTORMS. FORECAST CURRENTLY FEATURES HIGH CHANCE POPS OVER MUCH OF THE AREA DURING PEAK HEATING HOURS. A FEW STRONGER STORMS WILL BE POSSIBLE ESPECIALLY IN THE NORTHERN ZONES WHERE INSTABILITY AND MID LEVEL ENVIRONMENT IS MORE FAVORABLE...WITH GUSTY WINDS PRIMARY THREAT. FORECAST HEAT INDICES MAY BRIEFLY REACH THE LOCAL HEAT ADVISORY CRITERIA OF 105 IN THE AFTERNOON WITH HIGH TEMPERATURES IN THE LOW/MID 90S...HOWEVER DURATION AND AREAL EXTENT WILL BE MARGINAL AT BEST AND GIVEN EXPECTED CONVECTION...THINK A HEAT ADVISORY WILL LIKELY NOT BE NEEDED. CONVECTION MAY LINGER INTO THE OVERNIGHT PERIOD...WITH FOCUS SHIFTING MORE TO THE COASTAL WATERS. LOWS WILL AGAIN BE IN THE MID TO UPPER 70S. SATURDAY...THE UPPER LEVEL PATTERN WILL BECOME MUCH MORE AMPLIFIED AS DEEPENING TROUGH AND ASSOCIATED VORT MAX DIGS INTO THE GREAT LAKES REGION. THIS WILL HELP SEND ANOTHER AREA OF LOW PRESSURE TOWARDS EAST COAST WHICH WILL EVENTUALLY ENGULF THE STATIONARY FRONT/LOW. BETTER UPPER SUPPORT...DEEP MOISTURE AND VARIOUS SURFACE BOUNDARIES WILL ALLOW FOR A FAIRLY ACTIVE DAY WITH STRONGER STORMS POSSIBLE GIVEN DECENT SHEAR AND FORECAST INSTABILITY. HIGH TEMPERATURES WILL MAINLY BE IN THE LOW 90S. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... BROAD UPPER TROUGH WILL ENCOMPASS THE EASTERN U.S. THROUGH THE LONG TERM PERIOD. A POTENT SHORTWAVE WILL SEND AN AREA OF LOW PRESSURE AND ATTENDANT FRONT THROUGH THE FORECAST AREA ON SUNDAY. GIVEN FORCING FROM UPPER JET...SHORTWAVE ENERGY AND COLD FRONT...IT SHOULD BE A PRETTY ACTIVE DAY ESPECIALLY GIVEN DECENT SHEAR AND DEEP MOISTURE. THE FRONT WILL LIKELY PUSH OFF THE COAST EARLY MONDAY...AND REMAIN STATIONARY OFFSHORE BEFORE DISSIPATING TUESDAY. WEAK HIGH PRESSURE IS EXPECTED TO PREVAIL BY MID WEEK. TEMPERATURES WILL BE AT OR BELOW CLIMO THROUGH THE PERIOD. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... VFR THROUGH 12Z THURSDAY. POTENTIAL FOR AFTERNOON AND EVENING SHOWERS AND TSTMS TODAY IS TOO LOW FOR ANY MENTIONS IN THE CURRENT TAF CYCLE AT THIS TIME...ESPECIALLY WITH UNCERTAINTIES WITH TIMING AND COVERAGE. EXTENDED AVIATION OUTLOOK...BRIEF FLIGHT RESTRICTIONS POSSIBLE IN AFTERNOON SHOWERS/THUNDERSTORMS...ESPECIALLY THIS WEEKEND. && .MARINE... THE COASTAL WATERS SYNOPTIC PATTERN IS NOT CHANGING MUCH AND MARINERS FAMILIAR WITH THE SUMMER PATTERNS WILL NOT GET ANY BIG SURPRISES THROUGH TONIGHT. SOUTH/SW SEA BREEZE CIRCULATIONS AND SW NOCTURNAL SURGES WILL PUSH SPEEDS INTO THE 15-20 KT RANGE WITH SOME HIGHER GUSTS AT FAVORED AREAS SUCH AS THE CHARLESTON LAND/SEA INTERFACE WITH SEAS 2-4 FT ON AVERAGE...HIGHEST WELL OFFSHORE. WAVES IN THE HARBOR WILL BUILD TO 1 TO 2 FT THROUGH THIS EVENING. THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL PREVAIL OVER THE COASTAL WATERS WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND THROUGH THE REMAINDER OF THE WEEK. A COLD FRONT IS EXPECTED TO APPROACH THE WATERS OVER THE WEEKEND AND EVENTUALLY STALL AND DISSIPATE EARLY NEXT WEEK. TIGHTENED PRESSURE GRADIENT WILL KEEP WINDS FAIRLY ELEVATED THROUGH THE PERIOD. NOCTURNAL JETTING AND AFTERNOON SEA BREEZE CIRCULATIONS WILL RESULT IN SOUTH/SOUTHWEST WINDS PEAKING AROUND 15-20 KT...ESPECIALLY ACROSS THE CHARLESTON COUNTY COASTAL WATERS. GUSTS MAY REACH NEAR SMALL CRAFT ADVISORY CRITERIA OF 25 KT AT TIMES...AND HEADLINES MAY NEED TO BE CONSIDERED. SEAS WILL MAINLY BE 2-4 FEET...BUT MAY REACH 5-6 FEET IN THE OUTER PORTIONS OF THE WATERS DURING SURGES. && .CLIMATE... RECORD HIGH MINIMUMS FOR JUNE 24TH... KCHS...79 SET IN 1998. KCXM...85 SET IN 1998. KSAV...80 SET IN 1914. RECORD HIGH MINIMUMS FOR JUNE 25TH... KCHS...79 SET IN 2010. KCXM...83 SET IN 1998. KSAV...80 SET IN 1914. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR GAZ087-088- 099>101-114>119-137>141. SC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR SCZ040-042>045- 047>052. MARINE...NONE. && $$ SYNOPSIS... NEAR TERM... SHORT TERM...ECT LONG TERM...ECT AVIATION... MARINE... CLIMATE...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
517 PM CDT WED JUN 24 2015 .SHORT TERM... 317 PM CDT THROUGH SATURDAY... WILL BE PUSHING BACK THE START TIME OF THE FLASH FLOOD WATCH OVER EASTERN SECTIONS OF THE AREA TILL AROUND 06 UTC THIS EVENING...OTHERWISE NO CHANGES TO THE WATCH PLANNED. THE EARLY MORNING SHOWERS AND THUNDERSTORMS OVER WEST CENTRAL ILLINOIS PUSHED AN OUTFLOW BOUNDARY SOUTHWARD OVER MISSOURI...AND THIS HAS EFFECTIVELY PUSHED THE SURFACE WARM FRONT AND BETTER INSTABILITY FARTHER SOUTH OVER MISSOURI. AS SUCH...I HAVE SOME CONCERNS THAT THE HEAVY RAIN AND SEVERE THREAT...AT LEAST INITIALLY THIS EVENING MAY BE DELAYED AND FOCUSED OVER WESTERN PORTIONS OF ILLINOIS AND IOWA. THE HRRR RUNS HAVE BEEN PICKING UP ON THIS POSSIBILITY OVER THE PAST COUPLE HOURS...AND WITH THE SURFACE BOUNDARY STILL OVER CENTRAL AND WESTERN SECTIONS OF MISSOURI...I AM THINKING IT MAY BE HEADING IN THE RIGHT DIRECTION. WITH THIS IN MIND I DID CUT BACK ON POPS THIS EVENING OVER EASTERN SECTIONS OF THE REGION AND HAVE PUSHED THE FLASH FLOOD WATCH OFF UNTIL 05 UTC FOR THE CHICAGO METRO AREA AND NORTHWESTERN INDIANA. THE CONVECTIVE ACTIVITY OVER IOWA IS ASSOCIATED WITH AN MCV...AND THIS MAY MOVE OVER PORTIONS OF NORTHERN ILLINOIS LATE THIS AFTERNOON AND EARLY THIS EVENING. HOWEVER...IT APPEARS WITH THE INSTABILITY GRADIENT REMAINING TO OUR SOUTHWEST...THUNDERSTORMS WILL LIKELY BECOME MORE SCATTERED WITH THE EASTWARD EXTENT OF THIS PRECIPITATION. THEREFORE...ONLY A FEW LINGERING SHOWERS AND PERHAPS A FEW THUNDERSTORMS MAY MOVE OVER THE AREA THROUGH EARLY THIS EVENING. THUNDERSTORMS WILL STILL LIKELY BEGIN TO DEVELOP UPSTREAM OVER EASTERN IOWA AND INTO WESTERN ILLINOIS THROUGH THE EVENING A SOUTHWESTERLY LOW LEVEL JET NOSES INTO THIS AREA. THIS WILL RESULT IN BACKBULDING AND TRAINING THUNDERSTORMS WITH HEAVY RAINFALL. HOWEVER...IT APPEARS THE MAIN FOCUS FOR THIS ACTIVITY MAY REMAIN JUST WEST OF MY AREA...AT LEAST FOR MUCH OF THE EVENING. WITH TIME...IT APPEARS THE FOCUS MAY BEGIN TO SHIFT EASTWARD INTO NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA...BUT THIS MAY NOT BE UNTIL AFTER MIDNIGHT TONIGHT. HEAVY RAIN RATES WILL STILL BE A CONCERN...AND IT APPEARS THE HEAVIEST RAIN MAY FALL SOUTH OF INTERSTATE 88. THE HEAVY RAIN THREAT WILL CONTINUE INTO THE LATE MORNING/EARLY AFTERNOON ON THURSDAY...ESPECIALLY SOUTH OF I-80 AS THE SURFACE SYSTEM MOVES OVER THE AREA. HOWEVER...ONCE THE SURFACE LOW PASSES EAST...THE FRONTAL BOUNDARY WILL SHIFT SOUTH OF THE AREA LATER IN THE DAY...BRINGING THE SHOWER AND STORM THREAT TO AN END. AS FOR THE SEVERE THREAT...IT APPEARS THIS TOO MAY END UP BEING FARTHER SOUTH THAN PREVIOUSLY THOUGHT. ALTHOUGH UNCERTAINTY REMAINS AS TO HOW THE SEVERE THREAT WILL EVOLVE TONIGHT. IT APPEARS AT THIS POINT THAT THE HIGHEST THREAT MAY END UP BEING PRIMARILY SOUTH OF INTERSTATE 80...AND BE MAINLY A DAMAGING WIND THREAT. MUCH COOLER WEATHER WILL BUILD IN OVER MUCH OF THE REGION IN THE WAKE OF THIS FRONT. ANOTHER SYSTEM LOOKS TO DEVELOP AND IMPACT THE OHIO VALLEY REGION LATER FRIDAY INTO EARLY SATURDAY AS AN UPPER TROUGH DIGS OVER THE LOWER GREAT LAKES REGION. IT APPEARS MOST OF THE PRECIP WITH THIS SYSTEM WILL REMAIN SOUTH OF MOST OF MY AREA. COOL CONDITIONS WILL BE THE RULE FOR A FEW DAYS...WITH A BREAK IN THE WEATHER...FINALLY. KJB && .LONG TERM... 346 AM CDT ADVERTISED UPPER LEVEL PATTERN SHIFT TO A MUCH HIGHER AMPLITUDE FLOW WILL BE IN PLACE BY SUNDAY. THIS HIGH AMPLIFIED PATTERN WILL BREAK DOWN GRADUALLY WITH TIME THROUGH THE 4 DAY PERIOD BUT A NORTHWEST FLOW ALOFT WILL PERSIST THROUGH WEDNESDAY. WHILE MODELS TO DEPICT A SERIES OF UPPER LEVEL SHORTWAVES TO SLIDE ACROSS THE AREA THROUGH THE PERIOD THE NATURE OF THE PRECIPITATION SYSTEMS THESE FEATURES WILL PRODUCE WILL BE MUCH DIFFERENT COMPARED TO THE PAST 3 WEEKS. DESPITE MENTION OF POPS EACH DAY THERE WILL BE LONG DRY SPELLS IN BETWEEN AND ANY RAIN THAT DOES FALL WILL BE GENERALLY BRIEF AND RELATIVELY LIGHT. THE BETTER WINDOWS FOR RAINFALL APPEAR TO BE DIURNALLY ENHANCED DURING THE AFTERNOONS MONDAY AND TUESDAY AND ASSOCIATED WITH A PAIR OF WEAK SECONDARY COLD FRONTS BEING DRIVEN SOUTH VIA UPPER LEVEL IMPULSES. TEMPERATURES WILL REMAIN BELOW AVERAGE THROUGH THE PERIOD WITH LAKE BREEZES EXPECTED SUNDAY AND WEDNESDAY... AND POSSIBLY LATE TUESDAY AS WELL. && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * AREA OF LGT-MOD RA TO MOVE ACROSS TERMINALS ROUGHLY 2330Z-0200Z. LITTLE IN WAY OF LIGHTNING EXPECTED...THOUGH BRIEF 4-6SM VIS AND MID/HIGH BASED MVFR CIG POSSIBLE DURING PRECIP. * LIGHT/VARIABLE WINDS LESS THAN 10 KT INTO EARLY THIS EVENING... THOUGH MAY FAVOR A TREND IN DIRECTION FROM SW BACKING TO SE OR E BY EARLY EVENING. * THUNDERSTORM POTENTIAL APPEARS TO BE DECREASING THROUGH MIDNIGHT AS FOCUS EXPECTED TO BE FROM WEST/CENTRAL IA INTO CENTRAL IL AT THIS TIME. RATZER //DISCUSSION...UPDATED 22Z... MCV...MESOSCALE VORTICITY CENTER...CURRENTLY CENTERED JUST EAST OF KCID/CEDAR RAPIDS IOWA AT 22Z. AREA OF LIGHT-MODERATE RAIN IN ADVANCE OF THIS MID-LEVEL FEATURE EXTENDS INTO NORTHWEST/NORTH CENTRAL IL AND EXTRAPOLATION OF RADAR FEATURES SUGGESTS A PERIOD OF LIGHT-MODERATE RAIN FOR TERMINALS ALREADY BEGUN AT KRFD...WILL ARRIVE CHI TERMINALS BETWEEN 23-00Z. LIGHTNING DETECTION NETWORK SHOWING DECREASING TREND WITH INTRA-CLOUD DISCHARGES...AND DECREASING INSTABILITY FARTHER EAST SUGGESTS ONLY LOW THUNDER PROBABILITY FOR TERMINALS. TIMING OF TRAILING EDGE SUGGESTS RAIN ENDING AROUND 01Z FOR KRFD...02Z-ISH FOR CHICAGO TERMINALS. THUNDER THREAT LATER THIS EVENING LOOKS LATER THAN PREVIOUS FORECAST...AND HAVE PUSHED THUNDER BACK TO AFTER MIDNIGHT. RATZER PREVIOUS DISCUSSION FROM 18Z... AT THE SURFACE...A LARGE AREA OF HIGH PRESSURE IS CENTERED ALONG THE IN/OH BORDER AS A MID LEVEL IMPULSE CROSSING THE MIDDLE MISSISSIPPI VALLEY IS BRINGING AN AREA OF SHOWERS AND THUNDERSTORMS FROM IOWA THROUGH CENTRAL IL TO CENTRAL IN. BASED ON THE LATEST RADAR TRENDS...EXPECT THAT ANY PCPN AND TS SHOULD REMAIN SOUTH OF OF THE TERMINALS EARLY THIS EVENING...THROUGH IT COULD CLIP THE SOUTHERN PORTIONS OF THE C90 TRACON AREA. AS THE CENTER OF THE HIGH CONTINUES TO SHIFT TO THE EAST...WINDS HAVE BECOME SSWLY AND ARE INCREASING TO ARND 10KT. LATEST RADAR IMAGERY AND COASTAL OBSERVATIONS SHOW A LAKE BREEZE MOVING ONSHORE NEAR KUGN...BUT THERE IS LITTLE WESTWARD PROGRESSION AND DO NOT EXPECT THAT THE BOUNDARY WILL REACH AS FAR WEST AS ORD/MDW. RATHER...EXPECT THAT WINDS WILL GRADUALLY BACK TO MORE SELY THROUGH THE AFTERNOON AND INTO THE EVENING IN RESPONSE TO THE LARGER SCALE PRESSURE PATTERN WITH THE HIGH MOVING OFF TO THE EAST AND LOW PRESSURE DEVELOPING OVER THE CNTRL PLAINS. THE OTHER CONCERN FOR THE PERIOD WILL BE TIMING THE NEXT ROUND OF THUNDERSTORMS TO IMPACT THE REGION. WHILE THE ONGOING PCPN SHOULD REMAIN SOUTH OF THE TERMINALS...CONFIDENCE IS HIGHER THAT ANOTHER ROUND OF THUNDERSTORMS WILL DEVELOP TONIGHT OVER THE CNTRL PLAINS/IOWA AND THEN TRACK EASTWARD. LATEST GUIDANCE IS A LITTLE FASTER THAN PREVIOUS MODEL RUNS AND SUGGESTS THAT TS COULD REACH RFD BY ARND 03Z...AND THEN QUICKLY PUSHING TO THE EAST ACROSS THE CHICAGO AREA TERMINALS. WHILE CONFIDENCE IS RELATIVELY HIGH IN TS IMPACTING THE TERMINALS OVERNIGHT TONIGHT...TIMING AND DURATION IS A LITTLE LOWER. ALSO...AS THE MAIN SFC LOW TRACKS ALONG A DEVELOPING WARM FRONT EXPECTED TO SET THROUGH CNTRL OR NRN IL/IN AND WITH UPPER LEVEL FLOW SETTING UP TO BE PARALLEL TO THE SFC FRONT...AN EXTENDED PERIOD OF TSRA IMPACTING THE TERMINALS IS QUITE POSSIBLE OVERNIGHT AND POSSIBLY EVEN INTO TOMORROW MORNING. KREIN //ORD AND MDW CONFIDENCE...UPDATED 22Z... * MEDIUM CONFIDENCE IN WIND DIRECTION TRENDS...HIGH CONFIDENCE IN WINDS GENERALLY LESS THAN 10 KTS THIS EVE. * HIGH CONFIDENCE IN RA TIMING AND GENERAL LACK OF TSRA THIS EVENING. * LOW CONFIDENCE IN TSRA AFFECTING TERMINALS OVERNIGHT AND WITH TIMING IF THEY DO. RATZER //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. WX NIL. NELY WINDS. FRIDAY...VFR. WX NIL. NELY WINDS. SATURDAY...VFR. WX NIL. NELY WINDS BACKING NWLY LATE. SUNDAY...CHANCE TSRA. MVFR POSSIBLE. NWLY WINDS BACKING SWLY. MONDAY...CHANCE TSRA. MVFR POSSIBLE. SWLY WINDS VEERING NWLY TUESDAY...SLIGHT CHANCE TSRA. VRBL WINDS. KREIN && .MARINE... 258 PM CDT HIGH PRESSURE RIDGING ACROSS THE SOUTHERN GREAT LAKES WILL EXIT THE AREA TO THE EAST THIS EVENING ALLOWING LOW PRESSURE OVER THE CENTRAL PLAINS TO MOVE NORTHEAST INTO NORTHERN ILLINOIS BY THURSDAY MORNING. MEANWHILE A WEAK COLD FRONT ACROSS THE NORTHERN GREAT LAKES WILL SAG SOUTH AHEAD OF HIGH PRESSURE OVER ONTARIO AND WASH OUT AS THE AFFOREMENTIONED LOW PRESSURE AREA MOVES INTO ILLINOIS. AS THIS LOW MOVES EAST TO OHIO THURSDAY NIGHT ITS ASSOCIATED COLD FRONT WILL DROP SOUTH AWAY FROM THE AREA ALLOWING ANOTHER AREA OF WEAK HIGH PRESSURE TO BUILD ACROSS THE GREAT LAKES. THIS HIGH WILL DRIFT EAST SUNDAY NIGHT INTO MONDAY ALLOWING A SECONDARY COLD FRONT TO SAG SOUTH ACROSS THE NORTHERN GREAT LAKES. ED F && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-ILZ019- ILZ021-ILZ032-ILZ039 UNTIL 1 PM THURSDAY. FLASH FLOOD WATCH...ILZ005-ILZ006-ILZ012-ILZ013-ILZ014-ILZ020- ILZ022-ILZ023-ILZ033...MIDNIGHT THURSDAY TO 1 PM THURSDAY. IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011- INZ019...MIDNIGHT THURSDAY TO 1 PM THURSDAY. LM...NONE. && $$ 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
346 PM CDT WED JUN 24 2015 .SHORT TERM... 317 PM CDT THROUGH SATURDAY... WILL BE PUSHING BACK THE START TIME OF THE FLASH FLOOD WATCH OVER EASTERN SECTIONS OF THE AREA TILL AROUND 06 UTC THIS EVENING...OTHERWISE NO CHANGES TO THE WATCH PLANNED. THE EARLY MORNING SHOWERS AND THUNDERSTORMS OVER WEST CENTRAL ILLINOIS PUSHED AN OUTFLOW BOUNDARY SOUTHWARD OVER MISSOURI...AND THIS HAS EFFECTIVELY PUSHED THE SURFACE WARM FRONT AND BETTER INSTABILITY FARTHER SOUTH OVER MISSOURI. AS SUCH...I HAVE SOME CONCERNS THAT THE HEAVY RAIN AND SEVERE THREAT...AT LEAST INITIALLY THIS EVENING MAY BE DELAYED AND FOCUSED OVER WESTERN PORTIONS OF ILLINOIS AND IOWA. THE HRRR RUNS HAVE BEEN PICKING UP ON THIS POSSIBILITY OVER THE PAST COUPLE HOURS...AND WITH THE SURFACE BOUNDARY STILL OVER CENTRAL AND WESTERN SECTIONS OF MISSOURI...I AM THINKING IT MAY BE HEADING IN THE RIGHT DIRECTION. WITH THIS IN MIND I DID CUT BACK ON POPS THIS EVENING OVER EASTERN SECTIONS OF THE REGION AND HAVE PUSHED THE FLASH FLOOD WATCH OFF UNTIL 05 UTC FOR THE CHICAGO METRO AREA AND NORTHWESTERN INDIANA. THE CONVECTIVE ACTIVITY OVER IOWA IS ASSOCIATED WITH AN MCV...AND THIS MAY MOVE OVER PORTIONS OF NORTHERN ILLINOIS LATE THIS AFTERNOON AND EARLY THIS EVENING. HOWEVER...IT APPEARS WITH THE INSTABILITY GRADIENT REMAINING TO OUR SOUTHWEST...THUNDERSTORMS WILL LIKELY BECOME MORE SCATTERED WITH THE EASTWARD EXTENT OF THIS PRECIPITATION. THEREFORE...ONLY A FEW LINGERING SHOWERS AND PERHAPS A FEW THUNDERSTORMS MAY MOVE OVER THE AREA THROUGH EARLY THIS EVENING. THUNDERSTORMS WILL STILL LIKELY BEGIN TO DEVELOP UPSTREAM OVER EASTERN IOWA AND INTO WESTERN ILLINOIS THROUGH THE EVENING A SOUTHWESTERLY LOW LEVEL JET NOSES INTO THIS AREA. THIS WILL RESULT IN BACKBULDING AND TRAINING THUNDERSTORMS WITH HEAVY RAINFALL. HOWEVER...IT APPEARS THE MAIN FOCUS FOR THIS ACTIVITY MAY REMAIN JUST WEST OF MY AREA...AT LEAST FOR MUCH OF THE EVENING. WITH TIME...IT APPEARS THE FOCUS MAY BEGIN TO SHIFT EASTWARD INTO NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA...BUT THIS MAY NOT BE UNTIL AFTER MIDNIGHT TONIGHT. HEAVY RAIN RATES WILL STILL BE A CONCERN...AND IT APPEARS THE HEAVIEST RAIN MAY FALL SOUTH OF INTERSTATE 88. THE HEAVY RAIN THREAT WILL CONTINUE INTO THE LATE MORNING/EARLY AFTERNOON ON THURSDAY...ESPECIALLY SOUTH OF I-80 AS THE SURFACE SYSTEM MOVES OVER THE AREA. HOWEVER...ONCE THE SURFACE LOW PASSES EAST...THE FRONTAL BOUNDARY WILL SHIFT SOUTH OF THE AREA LATER IN THE DAY...BRINGING THE SHOWER AND STORM THREAT TO AN END. AS FOR THE SEVERE THREAT...IT APPEARS THIS TOO MAY END UP BEING FARTHER SOUTH THAN PREVIOUSLY THOUGHT. ALTHOUGH UNCERTAINTY REMAINS AS TO HOW THE SEVERE THREAT WILL EVOLVE TONIGHT. IT APPEARS AT THIS POINT THAT THE HIGHEST THREAT MAY END UP BEING PRIMARILY SOUTH OF INTERSTATE 80...AND BE MAINLY A DAMAGING WIND THREAT. MUCH COOLER WEATHER WILL BUILD IN OVER MUCH OF THE REGION IN THE WAKE OF THIS FRONT. ANOTHER SYSTEM LOOKS TO DEVELOP AND IMPACT THE OHIO VALLEY REGION LATER FRIDAY INTO EARLY SATURDAY AS AN UPPER TROUGH DIGS OVER THE LOWER GREAT LAKES REGION. IT APPEARS MOST OF THE PRECIP WITH THIS SYSTEM WILL REMAIN SOUTH OF MOST OF MY AREA. COOL CONDITIONS WILL BE THE RULE FOR A FEW DAYS...WITH A BREAK IN THE WEATHER...FINALLY. KJB && .LONG TERM... 346 AM CDT ADVERTISED UPPER LEVEL PATTERN SHIFT TO A MUCH HIGHER AMPLITUDE FLOW WILL BE IN PLACE BY SUNDAY. THIS HIGH AMPLIFIED PATTERN WILL BREAK DOWN GRADUALLY WITH TIME THROUGH THE 4 DAY PERIOD BUT A NORTHWEST FLOW ALOFT WILL PERSIST THROUGH WEDNESDAY. WHILE MODELS TO DEPICT A SERIES OF UPPER LEVEL SHORTWAVES TO SLIDE ACROSS THE AREA THROUGH THE PERIOD THE NATURE OF THE PRECIPITATION SYSTEMS THESE FEATURES WILL PRODUCE WILL BE MUCH DIFFERENT COMPARED TO THE PAST 3 WEEKS. DESPITE MENTION OF POPS EACH DAY THERE WILL BE LONG DRY SPELLS IN BETWEEN AND ANY RAIN THAT DOES FALL WILL BE GENERALLY BRIEF AND RELATIVELY LIGHT. THE BETTER WINDOWS FOR RAINFALL APPEAR TO BE DIURNALLY ENHANCED DURING THE AFTERNOONS MONDAY AND TUESDAY AND ASSOCIATED WITH A PAIR OF WEAK SECONDARY COLD FRONTS BEING DRIVEN SOUTH VIA UPPER LEVEL IMPULSES. TEMPERATURES WILL REMAIN BELOW AVERAGE THROUGH THE PERIOD WITH LAKE BREEZES EXPECTED SUNDAY AND WEDNESDAY... AND POSSIBLY LATE TUESDAY AS WELL. && ED F .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * CHANCE OF LAKE BREEZE DEVELOPMENT LATE THIS AFTERNOON. * THUNDERSTORMS LIKELY OVERNIGHT TONIGHT...MVFR-IFR CIGS/VIS LIKELY. KREIN //DISCUSSION...UPDATED 18Z... AT THE SURFACE...A LARGE AREA OF HIGH PRESSURE IS CENTERED ALONG THE IN/OH BORDER AS A MID LEVEL IMPULSE CROSSING THE MIDDLE MISSISSIPPI VALLEY IS BRINGING AN AREA OF SHOWERS AND THUNDERSTORMS FROM IOWA THROUGH CENTRAL IL TO CENTRAL IN. BASED ON THE LATEST RADAR TRENDS...EXPECT THAT ANY PCPN AND TS SHOULD REMAIN SOUTH OF OF THE TERMINALS EARLY THIS EVENING...THROUGH IT COULD CLIP THE SOUTHERN PORTIONS OF THE C90 TRACON AREA. AS THE CENTER OF THE HIGH CONTINUES TO SHIFT TO THE EAST...WINDS HAVE BECOME SSWLY AND ARE INCREASING TO ARND 10KT. LATEST RADAR IMAGERY AND COASTAL OBSERVATIONS SHOW A LAKE BREEZE MOVING ONSHORE NEAR KUGN...BUT THERE IS LITTLE WESTWARD PROGRESSION AND DO NOT EXPECT THAT THE BOUNDARY WILL REACH AS FAR WEST AS ORD/MDW. RATHER...EXPECT THAT WINDS WILL GRADUALLY BACK TO MORE SELY THROUGH THE AFTERNOON AND INTO THE EVENING IN RESPONSE TO THE LARGER SCALE PRESSURE PATTERN WITH THE HIGH MOVING OFF TO THE EAST AND LOW PRESSURE DEVELOPING OVER THE CNTRL PLAINS. THE OTHER CONCERN FOR THE PERIOD WILL BE TIMING THE NEXT ROUND OF THUNDERSTORMS TO IMPACT THE REGION. WHILE THE ONGOING PCPN SHOULD REMAIN SOUTH OF THE TERMINALS...CONFIDENCE IS HIGHER THAT ANOTHER ROUND OF THUNDERSTORMS WILL DEVELOP TONIGHT OVER THE CNTRL PLAINS/IOWA AND THEN TRACK EASTWARD. LATEST GUIDANCE IS A LITTLE FASTER THAN PREVIOUS MODEL RUNS AND SUGGESTS THAT TS COULD REACH RFD BY ARND 03Z...AND THEN QUICKLY PUSHING TO THE EAST ACROSS THE CHICAGO AREA TERMINALS. WHILE CONFIDENCE IS RELATIVELY HIGH IN TS IMPACTING THE TERMINALS OVERNIGHT TONIGHT...TIMING AND DURATION IS A LITTLE LOWER. ALSO...AS THE MAIN SFC LOW TRACKS ALONG A DEVELOPING WARM FRONT EXPECTED TO SET THROUGH CNTRL OR NRN IL/IN AND WITH UPPER LEVEL FLOW SETTING UP TO BE PARALLEL TO THE SFC FRONT...AN EXTENDED PERIOD OF TSRA IMPACTING THE TERMINALS IS QUITE POSSIBLE OVERNIGHT AND POSSIBLY EVEN INTO TOMORROW MORNING. KREIN //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM TO HIGH CONFIDENCE IN GENERAL WIND TRENDS. * MEDIUM CONFIDENCE IN LAKE BREEZE DETAILS...AND THAT THE LAKE BREEZE BOUNDARY WILL REMAIN EAST OF THE TERMINALS. * MEDIUM TO HIGH CONFIDENCE IN TS IMPACTING THE TERMINALS THIS EVENING AND TONIGHT...LOWER CONFIDENCE IN EXACT TIMING AND DURATION. * MEDIUM CONFIDENCE IN A PERIOD OF MVFR-IFR CIGS/VIS WITH THE TSRA/PCPN OVERNIGHT TONIGHT AND INTO TOMORROW MORNING. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. WX NIL. NELY WINDS. FRIDAY...VFR. WX NIL. NELY WINDS. SATURDAY...VFR. WX NIL. NELY WINDS BACKING NWLY LATE. SUNDAY...CHANCE TSRA. MVFR POSSIBLE. NWLY WINDS BACKING SWLY. MONDAY...CHANCE TSRA. MVFR POSSIBLE. SWLY WINDS VEERING NWLY TUESDAY...SLIGHT CHANCE TSRA. VRBL WINDS. KREIN && .MARINE... 258 PM CDT HIGH PRESSURE RIDGING ACROSS THE SOUTHERN GREAT LAKES WILL EXIT THE AREA TO THE EAST THIS EVENING ALLOWING LOW PRESSURE OVER THE CENTRAL PLAINS TO MOVE NORTHEAST INTO NORTHERN ILLINOIS BY THURSDAY MORNING. MEANWHILE A WEAK COLD FRONT ACROSS THE NORTHERN GREAT LAKES WILL SAG SOUTH AHEAD OF HIGH PRESSURE OVER ONTARIO AND WASH OUT AS THE AFFOREMENTIONED LOW PRESSURE AREA MOVES INTO ILLINOIS. AS THIS LOW MOVES EAST TO OHIO THURSDAY NIGHT ITS ASSOCIATED COLD FRONT WILL DROP SOUTH AWAY FROM THE AREA ALLOWING ANOTHER AREA OF WEAK HIGH PRESSURE TO BUILD ACROSS THE GREAT LAKES. THIS HIGH WILL DRIFT EAST SUNDAY NIGHT INTO MONDAY ALLOWING A SECONDARY COLD FRONT TO SAG SOUTH ACROSS THE NORTHERN GREAT LAKES. ED F && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-ILZ019- ILZ021-ILZ032-ILZ039...7 PM WEDNESDAY TO 1 PM THURSDAY. FLASH FLOOD WATCH...ILZ005-ILZ006-ILZ012-ILZ013-ILZ014-ILZ020- ILZ022-ILZ023-ILZ033...MIDNIGHT THURSDAY TO 1 PM THURSDAY. IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011- INZ019...MIDNIGHT THURSDAY TO 1 PM THURSDAY. LM...NONE. && $$ 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
318 PM CDT WED JUN 24 2015 .SHORT TERM... 317 PM CDT THROUGH SATURDAY... WILL BE PUSHING BACK THE START TIME OF THE FLASH FLOOD WATCH OVER EASTERN SECTIONS OF THE AREA TILL AROUND 06 UTC THIS EVENING...OTHERWISE NO CHANGES TO THE WATCH PLANNED. THE EARLY MORNING SHOWERS AND THUNDERSTORMS OVER WEST CENTRAL ILLINOIS PUSHED AN OUTFLOW BOUNDARY SOUTHWARD OVER MISSOURI...AND THIS HAS EFFECTIVELY PUSHED THE SURFACE WARM FRONT AND BETTER INSTABILITY FARTHER SOUTH OVER MISSOURI. AS SUCH...I HAVE SOME CONCERNS THAT THE HEAVY RAIN AND SEVERE THREAT...AT LEAST INITIALLY THIS EVENING MAY BE DELAYED AND FOCUSED OVER WESTERN PORTIONS OF ILLINOIS AND IOWA. THE HRRR RUNS HAVE BEEN PICKING UP ON THIS POSSIBILITY OVER THE PAST COUPLE HOURS...AND WITH THE SURFACE BOUNDARY STILL OVER CENTRAL AND WESTERN SECTIONS OF MISSOURI...I AM THINKING IT MAY BE HEADING IN THE RIGHT DIRECTION. WITH THIS IN MIND I DID CUT BACK ON POPS THIS EVENING OVER EASTERN SECTIONS OF THE REGION AND HAVE PUSHED THE FLASH FLOOD WATCH OFF UNTIL 05 UTC FOR THE CHICAGO METRO AREA AND NORTHWESTERN INDIANA. THE CONVECTIVE ACTIVITY OVER IOWA IS ASSOCIATED WITH AN MCV...AND THIS MAY MOVE OVER PORTIONS OF NORTHERN ILLINOIS LATE THIS AFTERNOON AND EARLY THIS EVENING. HOWEVER...IT APPEARS WITH THE INSTABILITY GRADIENT REMAINING TO OUR SOUTHWEST...THUNDERSTORMS WILL LIKELY BECOME MORE SCATTERED WITH THE EASTWARD EXTENT OF THIS PRECIPITATION. THEREFORE...ONLY A FEW LINGERING SHOWERS AND PERHAPS A FEW THUNDERSTORMS MAY MOVE OVER THE AREA THROUGH EARLY THIS EVENING. THUNDERSTORMS WILL STILL LIKELY BEGIN TO DEVELOP UPSTREAM OVER EASTERN IOWA AND INTO WESTERN ILLINOIS THROUGH THE EVENING A SOUTHWESTERLY LOW LEVEL JET NOSES INTO THIS AREA. THIS WILL RESULT IN BACKBULDING AND TRAINING THUNDERSTORMS WITH HEAVY RAINFALL. HOWEVER...IT APPEARS THE MAIN FOCUS FOR THIS ACTIVITY MAY REMAIN JUST WEST OF MY AREA...AT LEAST FOR MUCH OF THE EVENING. WITH TIME...IT APPEARS THE FOCUS MAY BEGIN TO SHIFT EASTWARD INTO NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA...BUT THIS MAY NOT BE UNTIL AFTER MIDNIGHT TONIGHT. HEAVY RAIN RATES WILL STILL BE A CONCERN...AND IT APPEARS THE HEAVIEST RAIN MAY FALL SOUTH OF INTERSTATE 88. THE HEAVY RAIN THREAT WILL CONTINUE INTO THE LATE MORNING/EARLY AFTERNOON ON THURSDAY...ESPECIALLY SOUTH OF I-80 AS THE SURFACE SYSTEM MOVES OVER THE AREA. HOWEVER...ONCE THE SURFACE LOW PASSES EAST...THE FRONTAL BOUNDARY WILL SHIFT SOUTH OF THE AREA LATER IN THE DAY...BRINGING THE SHOWER AND STORM THREAT TO AN END. AS FOR THE SEVERE THREAT...IT APPEARS THIS TOO MAY END UP BEING FARTHER SOUTH THAN PREVIOUSLY THOUGHT. ALTHOUGH UNCERTAINTY REMAINS AS TO HOW THE SEVERE THREAT WILL EVOLVE TONIGHT. IT APPEARS AT THIS POINT THAT THE HIGHEST THREAT MAY END UP BEING PRIMARILY SOUTH OF INTERSTATE 80...AND BE MAINLY A DAMAGING WIND THREAT. MUCH COOLER WEATHER WILL BUILD IN OVER MUCH OF THE REGION IN THE WAKE OF THIS FRONT. ANOTHER SYSTEM LOOKS TO DEVELOP AND IMPACT THE OHIO VALLEY REGION LATER FRIDAY INTO EARLY SATURDAY AS AN UPPER TROUGH DIGS OVER THE LOWER GREAT LAKES REGION. IT APPEARS MOST OF THE PRECIP WITH THIS SYSTEM WILL REMAIN SOUTH OF MOST OF MY AREA. COOL CONDITIONS WILL BE THE RULE FOR A FEW DAYS...WITH A BREAK IN THE WEATHER...FINALLY. KJB && .LONG TERM... 340 AM CDT THURSDAY THROUGH TUESDAY... THE UPPER LEVEL ZONAL FLOW FINALLY SHIFTS EAST LATE THIS WEEK AS AN UPPER LEVEL TROUGH MOVES OVER THE REGION FRIDAY NIGHT. THE TROUGH AXIS SHIFTS EAST SATURDAY WITH NORTHWEST FLOW SUNDAY. ANOTHER WEAKER TROUGH IS POSSIBLE EARLY NEXT WEEK. A SFC LOW WILL BE OVER NORTHERN IL AND NORTHWEST IN THURSDAY MORNING AS A DYING MCS SLOWLY SHIFTS EAST. RAISED QPF AMOUNTS THURSDAY MORNING AS THE DYING MCS SHOULD PRODUCE AT LEAST ANOTHER 0.35-0.5 INCHES OF RAIN SOUTH OF I-88. GUIDANCE DIFFERS ON HOW QUICKLY THE MCS WILL EXIT THE REGION...BUT HAVE HIGH CONFIDENCE IN DRY CONDITIONS THURSDAY NIGHT. SADLY THERE IS A VERY SMALL BREAK BEFORE THE NEXT LOW PRESSURE BRINGS MORE RAIN AND STORMS TO AREAS SOUTH OF I-80 FRIDAY. THE NEXT LOW FORMS OVER THE SOUTHERN PLAINS THURSDAY NIGHT. IT THEN PASSES OVER THE MID MISSISSIPPI VALLEY AND ALONG THE OHIO RIVER THROUGH SATURDAY NIGHT. IT LOOKS LIKE THE MAJORITY OF PRECIP WILL FALL OVER CENTRAL AND SOUTHERN IL...BUT KEPT A SLIGHT CHANCE TO CHANCE OF THUNDERSTORMS SOUTH OF I-88. WE FINALLY SEE A DRY SPELL LATE THIS WEEK AS THE LOW SHIFTS EAST AND HIGH PRESSURE SPREADS OVERHEAD. THE NEXT CHANCE OF RAIN AND STORMS ARRIVES EARLY NEXT WEEK AS AN UPPER LEVEL TROUGH SWINGS THROUGH. GUIDANCE DIFFERS ON HOW STRONG THE TROUGH WILL BE AND HOW FAR SOUTH IT WILL TRAVEL...BUT HAVE ENOUGH CONFIDENCE TO KEEP A CHANCE OF PRECIP IN THE FORECAST. WE COULD SEE MULTIPLE VORTICITY STREAMERS SWING THROUGH AS THE TROUGH SITS OVERHEAD SO KEPT A CHANCE OF PRECIP FROM SUNDAY NIGHT THROUGH TUESDAY. DESPITE THE CONSTANT CHANCE OF RAIN...ONLY EXPECTING PERIODS OF SHOWERS AND STORMS AT THIS POINT AND NOT COMPLETE RAIN OUTS. FOR TEMPS...THURSDAY LOOKS LIKE THE WARMEST DAY WITH HIGHS IN THE UPPER 70S TO LOW 80S. LAKE COOLING WILL KEEP LAKEFRONT LOCATIONS IN THE LOW 70S. COOLER AIR SINKS SOUTH THURSDAY NIGHT LEADING TO HIGH TEMPS FRIDAY IN THE 70S WITH 60S ALONG THE LAKE. A SLOW WARM UP IS EXPECTED WITH HIGHS BACK IN THE LOW 80S TUESDAY. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * CHANCE OF LAKE BREEZE DEVELOPMENT LATE THIS AFTERNOON. * THUNDERSTORMS LIKELY OVERNIGHT TONIGHT...MVFR-IFR CIGS/VIS LIKELY. KREIN //DISCUSSION...UPDATED 18Z... AT THE SURFACE...A LARGE AREA OF HIGH PRESSURE IS CENTERED ALONG THE IN/OH BORDER AS A MID LEVEL IMPULSE CROSSING THE MIDDLE MISSISSIPPI VALLEY IS BRINGING AN AREA OF SHOWERS AND THUNDERSTORMS FROM IOWA THROUGH CENTRAL IL TO CENTRAL IN. BASED ON THE LATEST RADAR TRENDS...EXPECT THAT ANY PCPN AND TS SHOULD REMAIN SOUTH OF OF THE TERMINALS EARLY THIS EVENING...THROUGH IT COULD CLIP THE SOUTHERN PORTIONS OF THE C90 TRACON AREA. AS THE CENTER OF THE HIGH CONTINUES TO SHIFT TO THE EAST...WINDS HAVE BECOME SSWLY AND ARE INCREASING TO ARND 10KT. LATEST RADAR IMAGERY AND COASTAL OBSERVATIONS SHOW A LAKE BREEZE MOVING ONSHORE NEAR KUGN...BUT THERE IS LITTLE WESTWARD PROGRESSION AND DO NOT EXPECT THAT THE BOUNDARY WILL REACH AS FAR WEST AS ORD/MDW. RATHER...EXPECT THAT WINDS WILL GRADUALLY BACK TO MORE SELY THROUGH THE AFTERNOON AND INTO THE EVENING IN RESPONSE TO THE LARGER SCALE PRESSURE PATTERN WITH THE HIGH MOVING OFF TO THE EAST AND LOW PRESSURE DEVELOPING OVER THE CNTRL PLAINS. THE OTHER CONCERN FOR THE PERIOD WILL BE TIMING THE NEXT ROUND OF THUNDERSTORMS TO IMPACT THE REGION. WHILE THE ONGOING PCPN SHOULD REMAIN SOUTH OF THE TERMINALS...CONFIDENCE IS HIGHER THAT ANOTHER ROUND OF THUNDERSTORMS WILL DEVELOP TONIGHT OVER THE CNTRL PLAINS/IOWA AND THEN TRACK EASTWARD. LATEST GUIDANCE IS A LITTLE FASTER THAN PREVIOUS MODEL RUNS AND SUGGESTS THAT TS COULD REACH RFD BY ARND 03Z...AND THEN QUICKLY PUSHING TO THE EAST ACROSS THE CHICAGO AREA TERMINALS. WHILE CONFIDENCE IS RELATIVELY HIGH IN TS IMPACTING THE TERMINALS OVERNIGHT TONIGHT...TIMING AND DURATION IS A LITTLE LOWER. ALSO...AS THE MAIN SFC LOW TRACKS ALONG A DEVELOPING WARM FRONT EXPECTED TO SET THROUGH CNTRL OR NRN IL/IN AND WITH UPPER LEVEL FLOW SETTING UP TO BE PARALLEL TO THE SFC FRONT...AN EXTENDED PERIOD OF TSRA IMPACTING THE TERMINALS IS QUITE POSSIBLE OVERNIGHT AND POSSIBLY EVEN INTO TOMORROW MORNING. KREIN //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM TO HIGH CONFIDENCE IN GENERAL WIND TRENDS. * MEDIUM CONFIDENCE IN LAKE BREEZE DETAILS...AND THAT THE LAKE BREEZE BOUNDARY WILL REMAIN EAST OF THE TERMINALS. * MEDIUM TO HIGH CONFIDENCE IN TS IMPACTING THE TERMINALS THIS EVENING AND TONIGHT...LOWER CONFIDENCE IN EXACT TIMING AND DURATION. * MEDIUM CONFIDENCE IN A PERIOD OF MVFR-IFR CIGS/VIS WITH THE TSRA/PCPN OVERNIGHT TONIGHT AND INTO TOMORROW MORNING. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. WX NIL. NELY WINDS. FRIDAY...VFR. WX NIL. NELY WINDS. SATURDAY...VFR. WX NIL. NELY WINDS BACKING NWLY LATE. SUNDAY...CHANCE TSRA. MVFR POSSIBLE. NWLY WINDS BACKING SWLY. MONDAY...CHANCE TSRA. MVFR POSSIBLE. SWLY WINDS VEERING NWLY TUESDAY...SLIGHT CHANCE TSRA. VRBL WINDS. KREIN && .MARINE... 258 PM CDT HIGH PRESSURE RIDGING ACROSS THE SOUTHERN GREAT LAKES WILL EXIT THE AREA TO THE EAST THIS EVENING ALLOWING LOW PRESSURE OVER THE CENTRAL PLAINS TO MOVE NORTHEAST INTO NORTHERN ILLINOIS BY THURSDAY MORNING. MEANWHILE A WEAK COLD FRONT ACROSS THE NORTHERN GREAT LAKES WILL SAG SOUTH AHEAD OF HIGH PRESSURE OVER ONTARIO AND WASH OUT AS THE AFFOREMENTIONED LOW PRESSURE AREA MOVES INTO ILLINOIS. AS THIS LOW MOVES EAST TO OHIO THURSDAY NIGHT ITS ASSOCIATED COLD FRONT WILL DROP SOUTH AWAY FROM THE AREA ALLOWING ANOTHER AREA OF WEAK HIGH PRESSURE TO BUILD ACROSS THE GREAT LAKES. THIS HIGH WILL DRIFT EAST SUNDAY NIGHT INTO MONDAY ALLOWING A SECONDARY COLD FRONT TO SAG SOUTH ACROSS THE NORTHERN GREAT LAKES. ED F && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-ILZ019- ILZ021-ILZ032-ILZ039...7 PM WEDNESDAY TO 1 PM THURSDAY. FLASH FLOOD WATCH...ILZ005-ILZ006-ILZ012-ILZ013-ILZ014-ILZ020- ILZ022-ILZ023-ILZ033...MIDNIGHT THURSDAY TO 1 PM THURSDAY. IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011- INZ019...MIDNIGHT THURSDAY TO 1 PM THURSDAY. LM...NONE. && $$ 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
258 PM CDT WED JUN 24 2015 .UPDATE... 1217 PM CDT ALL INDICATIONS THIS MORNING CONTINUE TO POINT TO A CLASSIC TYPE HEAVY RAIN EVENT ACROSS THE AREA. THE THREAT OF SEVERE THUNDERSTORMS IS ALSO DECENT WITH THIS ACTIVITY AS WELL LATER THIS EVENING...AND THIS PRIMARILY LOOKS TO BE IN THE FORM OF STRONG STRAIGHT LINE WINDS. SHOWERS...WITH SOME EMBEDDED THUNDERSTORMS CONTINUE TO WEAKEN OVER CENTRAL ILLINOIS AS THEY MOVE AWAY FROM THE BETTER FOCUS OF LAST NIGHTS LOW LEVEL JET. SATELLITE IMAGERY CONTINUES TO INDICATE CLOUD TOPS WARMING WITH THIS ACTIVITY...AND EVEN INDICATES SOME BREAKS IN THE CLOUDS OVER FAR NORTHERN ILLINOIS. FARTHER WEST...HOWEVER...AN AREA OF CONVECTION OVER EASTERN NE AND NEAR FAR WESTERN IOWA CONTINUES TO MAINTAIN ITSELF. IT IS CERTAINLY POSSIBLE THAT THIS ACTIVITY COULD CONTINUE TO MOVE EAST OVER IOWA INTO THIS AFTERNOON...THEN SHIFT MORE SOUTHEAST ALONG THE MLCAPE GRADIENT. THIS ACTIVITY...SHOULD IT MAINTAIN ITSELF THOUGH THE DAY...WOULD LIKELY MISS MOST OF MY AREA...POSSIBLY ONLY IMPACTING MY SOUTHWESTERN COUNTIES. SOME OF THE LATEST HRRR SOLUTIONS ARE IN LINE WITH THIS THINKING. OTHERWISE...THE FOCUS CONTINUES TO CENTER ON THIS EVENING THROUGH THE OVERNIGHT FOR THE POTENTIAL OF VERY HEAVY RAIN AND FLASH FLOODING. IT IS STILL ANTICIPATED THAT RENEWED CONVECTION WILL DEVELOP LATER THIS AFTERNOON/EARLY THIS EVENING OVER PORTIONS OF EASTERN IOWA INTO NORTHWESTERN ILLINOIS ALONG AND ON THE COOL SIDE OF A NORTHWARD MOVING WARM FRONTAL BOUNDARY. THIS ACTIVITY WOULD THEN LIKELY CONTINUE TO GROW UPSCALE AS RENEWED DEVELOPMENT CONTINUES UPSTREAM THANKS TO A PERSISTENT SOUTHWESTERLY 40+ KT LOW LEVEL JET CONTINUALLY REPLENISHING THE DEEP MOISTURE. THESE STORMS WILL OCCUR WITHIN AROUND A 2 INCH PRECIPITABLE WATER ENVIRONMENT...SO EXTREMELY HEAVY RAIN RATES WILL BE A HIGH CONCERN. ALSO...WITH CONTINUAL UPSTREAM DEVELOPMENT LOOKING LIKELY...TRAINING AND BACKBULDING OF CELLS COULD RESULT IN PROLONGED PERIODS OF THESE VERY HEAVY RAIN RATES OCCURRING OVER THE SAME AREAS. AS SUCH...SOME ISOLATED AREAS OVER THE AREA COULD EXPERIENCE 4-5+ INCH AMOUNTS OF RAIN BEFORE THIS ACTIVITY ABATES LATER TONIGHT OR EARLY THURSDAY MORNING. THERE ARE STILL SOME UNCERTAINTIES ON WHERE EXACTLY THE HEAVIEST RAINFALL AMOUNTS WILL FALL. HOWEVER...WITH THE ACTIVITY LIKELY TO MOVE EAST-SOUTHEAST WITH TIME...IT WOULD APPEAR THAT AREAS ALONG AND SOUTH OF INTERSTATE 88 WOULD LIKELY STAND THE BEST POTENTIAL TO EXPERIENCE RAINFALL AMOUNTS IN EXCESS OF 1 TO 2 INCHES. WITHIN THESE TRAINING THUNDERSTORMS...THE KINEMATIC FIELDS OVER THE AREA WILL ALSO LIKELY SUPPORT FORWARD PROPAGATING EAST-SOUTHEASTWARD MOVING BOWING SEGMENTS OVER THE AREA. THEREFORE...STRONG DAMAGING WINDS...PERHAPS IN EXCESS OF 70 MPH...WILL ALSO BE A THREAT WITH THESE STORMS. A TORNADO OR TWO CAN ALSO NOT BE RULED OUT. HOWEVER... THIS THREAT APPEARS TO BE THE HIGHEST OVER MY SOUTHEASTERN CWA THIS EVENING IN CLOSER PROXIMATELY TO THE APPROACHING WARM FRONTAL BOUNDARY. KJB && .SHORT TERM... 320 AM CDT THROUGH WEDNESDAY NIGHT... STRONG TO SEVERE THUNDERSTORMS COMPRISE THE PRIMARY FORECAST CONCERNS FOR TODAY AND TONIGHT. EARLY THIS MORNING...SURFACE HIGH PRESSURE IS CENTERED ACROSS CENTRAL ILLINOIS PROVIDING MOSTLY CLEAR SKIES AND LIGHT WINDS ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA. FARTHER WEST...A SURFACE TROUGH IS ANALYZED FROM NORTHERN KANSAS NE ACROSS THE MID- MISSOURI VALLEY INTO CENTRAL IOWA. WATER VAPOR IMAGERY SHOWS A SUBTLE/SHEARED WAVE EMBEDDED WITHIN THE MAINLY ZONAL FLOW ALOFT MOVING ACROSS NORTHERN IOWA WHERE NOCTURNAL THUNDERSTORMS HAVE DEVELOPED MAINLY FOCUSED ACROSS THE I-80 CORRIDOR IN IOWA. NAM/GFS INITIALIZE ON THIS AREA OF THUNDERSTORMS AND KEEPS THE FORCING FOCUSED TO THE WEST OF THE FORECAST AREA THROUGH MOST OF THE DAY TODAY...ALONG WITH THE INSTABILITY. CANT RULE OUT SOME DECAYING ELEVATED CONVECTION PROPAGATING INTO THE FORECAST AREA LATER TODAY...HOWEVER EXPECT MOST OF THE CWA TO BE DRY THIS MORNING INTO AT LEAST EARLY EVENING. WILL HAVE TO KEEP AN EYE ON HOW EARLY MORNING CONVECTION IMPACTS THE MOVEMENT OF THE WARM FRONT THROUGH THE DAY. THIS EVENING...SURFACE TROUGH/WARM FRONT IS PROGGED TO SETTLE ACROSS CENTRAL/NORTHERN IOWA INTO NORTHERN ILLINOIS THOUGH THERE ARE NOTABLE DIFFERENCES AT THIS POINT AS TO EXACTLY HOW FAR NORTH. VERY STRONG INSTABILITY IS EXPECTED TO DEVELOP SOUTH OF THE FRONT WITH THUNDERSTORMS EXPECTED TO REDEVELOP/RESTRENGTHEN ACROSS IOWA AFTERNOON INTO THE EVENING AS ANOTHER SHEARED VORT LOBE TRAVERSES ACROSS THE REGION AND RIGHT ENTRANCE REGION TO THE LOW LEVEL JET PROVIDES ADDITIONAL SYNOPTIC SCALE ASCENT. ASSUMING ATMOSPHERE EFFECTIVELY RECOVERS FROM MORNING CONVECTION...FAVORABLE SHEAR/INSTABILITY PROFILES...IMPRESSIVE CYCLONICALLY CURVED HODOGRAPHS AND WHAT SHOULD BE SUFFICIENT FORCING TO OVERCOME ANY CAPPING INVERSION WILL RESULT IN STRONG TO SEVERE THUNDERSTORMS DEVELOPING WEST OF THE CWA...POSSIBLY IN A DISCRETE/SUPERCELL MODE INITIALLY WITH THE FULL GAMUT OF SEVERE WEATHER POSSIBLE. STRENGTHENING NOCTURNAL LOW LEVEL JET INTO THE EVENING WILL RESULT IN STORMS MERGING INTO AN MCS AND PUSHING EAST INTO THE LOCAL FORECAST AREA. AS THIS OCCURS...EXPECT THE PRIMARY SEVERE THREAT TO CHANGE TO MORE OF A STRAIGHT LINE WIND DAMAGE AND FLOODING THREAT. CORFIDI VECTORS DROP OFF TO AROUND 5 KT OR SO ON THE SOUTHERN FLANK OF THE STORMS SO BACKBUILDING AND TRAINING THUNDERSTORMS REMAIN A CONCERN. A FLASH FLOOD WATCH WAS ISSUED YESTERDAY AND OPTED TO EXPAND NORTHWARD GIVEN THE TRENDS FROM THE GFS/NAM...ALTHOUGH CONFIDENCE IS ADMITTEDLY A BIT LOWER ACROSS THE NORTHERN TIER OF COUNTIES. DEUBELBEISS && .LONG TERM... 340 AM CDT THURSDAY THROUGH TUESDAY... THE UPPER LEVEL ZONAL FLOW FINALLY SHIFTS EAST LATE THIS WEEK AS AN UPPER LEVEL TROUGH MOVES OVER THE REGION FRIDAY NIGHT. THE TROUGH AXIS SHIFTS EAST SATURDAY WITH NORTHWEST FLOW SUNDAY. ANOTHER WEAKER TROUGH IS POSSIBLE EARLY NEXT WEEK. A SFC LOW WILL BE OVER NORTHERN IL AND NORTHWEST IN THURSDAY MORNING AS A DYING MCS SLOWLY SHIFTS EAST. RAISED QPF AMOUNTS THURSDAY MORNING AS THE DYING MCS SHOULD PRODUCE AT LEAST ANOTHER 0.35-0.5 INCHES OF RAIN SOUTH OF I-88. GUIDANCE DIFFERS ON HOW QUICKLY THE MCS WILL EXIT THE REGION...BUT HAVE HIGH CONFIDENCE IN DRY CONDITIONS THURSDAY NIGHT. SADLY THERE IS A VERY SMALL BREAK BEFORE THE NEXT LOW PRESSURE BRINGS MORE RAIN AND STORMS TO AREAS SOUTH OF I-80 FRIDAY. THE NEXT LOW FORMS OVER THE SOUTHERN PLAINS THURSDAY NIGHT. IT THEN PASSES OVER THE MID MISSISSIPPI VALLEY AND ALONG THE OHIO RIVER THROUGH SATURDAY NIGHT. IT LOOKS LIKE THE MAJORITY OF PRECIP WILL FALL OVER CENTRAL AND SOUTHERN IL...BUT KEPT A SLIGHT CHANCE TO CHANCE OF THUNDERSTORMS SOUTH OF I-88. WE FINALLY SEE A DRY SPELL LATE THIS WEEK AS THE LOW SHIFTS EAST AND HIGH PRESSURE SPREADS OVERHEAD. THE NEXT CHANCE OF RAIN AND STORMS ARRIVES EARLY NEXT WEEK AS AN UPPER LEVEL TROUGH SWINGS THROUGH. GUIDANCE DIFFERS ON HOW STRONG THE TROUGH WILL BE AND HOW FAR SOUTH IT WILL TRAVEL...BUT HAVE ENOUGH CONFIDENCE TO KEEP A CHANCE OF PRECIP IN THE FORECAST. WE COULD SEE MULTIPLE VORTICITY STREAMERS SWING THROUGH AS THE TROUGH SITS OVERHEAD SO KEPT A CHANCE OF PRECIP FROM SUNDAY NIGHT THROUGH TUESDAY. DESPITE THE CONSTANT CHANCE OF RAIN...ONLY EXPECTING PERIODS OF SHOWERS AND STORMS AT THIS POINT AND NOT COMPLETE RAIN OUTS. FOR TEMPS...THURSDAY LOOKS LIKE THE WARMEST DAY WITH HIGHS IN THE UPPER 70S TO LOW 80S. LAKE COOLING WILL KEEP LAKEFRONT LOCATIONS IN THE LOW 70S. COOLER AIR SINKS SOUTH THURSDAY NIGHT LEADING TO HIGH TEMPS FRIDAY IN THE 70S WITH 60S ALONG THE LAKE. A SLOW WARM UP IS EXPECTED WITH HIGHS BACK IN THE LOW 80S TUESDAY. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * CHANCE OF LAKE BREEZE DEVELOPMENT LATE THIS AFTERNOON. * THUNDERSTORMS LIKELY OVERNIGHT TONIGHT...MVFR-IFR CIGS/VIS LIKELY. KREIN //DISCUSSION...UPDATED 18Z... AT THE SURFACE...A LARGE AREA OF HIGH PRESSURE IS CENTERED ALONG THE IN/OH BORDER AS A MID LEVEL IMPULSE CROSSING THE MIDDLE MISSISSIPPI VALLEY IS BRINGING AN AREA OF SHOWERS AND THUNDERSTORMS FROM IOWA THROUGH CENTRAL IL TO CENTRAL IN. BASED ON THE LATEST RADAR TRENDS...EXPECT THAT ANY PCPN AND TS SHOULD REMAIN SOUTH OF OF THE TERMINALS EARLY THIS EVENING...THROUGH IT COULD CLIP THE SOUTHERN PORTIONS OF THE C90 TRACON AREA. AS THE CENTER OF THE HIGH CONTINUES TO SHIFT TO THE EAST...WINDS HAVE BECOME SSWLY AND ARE INCREASING TO ARND 10KT. LATEST RADAR IMAGERY AND COASTAL OBSERVATIONS SHOW A LAKE BREEZE MOVING ONSHORE NEAR KUGN...BUT THERE IS LITTLE WESTWARD PROGRESSION AND DO NOT EXPECT THAT THE BOUNDARY WILL REACH AS FAR WEST AS ORD/MDW. RATHER...EXPECT THAT WINDS WILL GRADUALLY BACK TO MORE SELY THROUGH THE AFTERNOON AND INTO THE EVENING IN RESPONSE TO THE LARGER SCALE PRESSURE PATTERN WITH THE HIGH MOVING OFF TO THE EAST AND LOW PRESSURE DEVELOPING OVER THE CNTRL PLAINS. THE OTHER CONCERN FOR THE PERIOD WILL BE TIMING THE NEXT ROUND OF THUNDERSTORMS TO IMPACT THE REGION. WHILE THE ONGOING PCPN SHOULD REMAIN SOUTH OF THE TERMINALS...CONFIDENCE IS HIGHER THAT ANOTHER ROUND OF THUNDERSTORMS WILL DEVELOP TONIGHT OVER THE CNTRL PLAINS/IOWA AND THEN TRACK EASTWARD. LATEST GUIDANCE IS A LITTLE FASTER THAN PREVIOUS MODEL RUNS AND SUGGESTS THAT TS COULD REACH RFD BY ARND 03Z...AND THEN QUICKLY PUSHING TO THE EAST ACROSS THE CHICAGO AREA TERMINALS. WHILE CONFIDENCE IS RELATIVELY HIGH IN TS IMPACTING THE TERMINALS OVERNIGHT TONIGHT...TIMING AND DURATION IS A LITTLE LOWER. ALSO...AS THE MAIN SFC LOW TRACKS ALONG A DEVELOPING WARM FRONT EXPECTED TO SET THROUGH CNTRL OR NRN IL/IN AND WITH UPPER LEVEL FLOW SETTING UP TO BE PARALLEL TO THE SFC FRONT...AN EXTENDED PERIOD OF TSRA IMPACTING THE TERMINALS IS QUITE POSSIBLE OVERNIGHT AND POSSIBLY EVEN INTO TOMORROW MORNING. KREIN //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM TO HIGH CONFIDENCE IN GENERAL WIND TRENDS. * MEDIUM CONFIDENCE IN LAKE BREEZE DETAILS...AND THAT THE LAKE BREEZE BOUNDARY WILL REMAIN EAST OF THE TERMINALS. * MEDIUM TO HIGH CONFIDENCE IN TS IMPACTING THE TERMINALS THIS EVENING AND TONIGHT...LOWER CONFIDENCE IN EXACT TIMING AND DURATION. * MEDIUM CONFIDENCE IN A PERIOD OF MVFR-IFR CIGS/VIS WITH THE TSRA/PCPN OVERNIGHT TONIGHT AND INTO TOMORROW MORNING. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. WX NIL. NELY WINDS. FRIDAY...VFR. WX NIL. NELY WINDS. SATURDAY...VFR. WX NIL. NELY WINDS BACKING NWLY LATE. SUNDAY...CHANCE TSRA. MVFR POSSIBLE. NWLY WINDS BACKING SWLY. MONDAY...CHANCE TSRA. MVFR POSSIBLE. SWLY WINDS VEERING NWLY TUESDAY...SLIGHT CHANCE TSRA. VRBL WINDS. KREIN && .MARINE... 258 PM CDT HIGH PRESSURE RIDGING ACROSS THE SOUTHERN GREAT LAKES WILL EXIT THE AREA TO THE EAST THIS EVENING ALLOWING LOW PRESSURE OVER THE CENTRAL PLAINS TO MOVE NORTHEAST INTO NORTHERN ILLINOIS BY THURSDAY MORNING. MEANWHILE A WEAK COLD FRONT ACROSS THE NORTHERN GREAT LAKES WILL SAG SOUTH AHEAD OF HIGH PRESSURE OVER ONTARIO AND WASH OUT AS THE AFFOREMENTIONED LOW PRESSURE AREA MOVES INTO ILLINOIS. AS THIS LOW MOVES EAST TO OHIO THURSDAY NIGHT ITS ASSOCIATED COLD FRONT WILL DROP SOUTH AWAY FROM THE AREA ALLOWING ANOTHER AREA OF WEAK HIGH PRESSURE TO BUILD ACROSS THE GREAT LAKES. THIS HIGH WILL DRIFT EAST SUNDAY NIGHT INTO MONDAY ALLOWING A SECONDARY COLD FRONT TO SAG SOUTH ACROSS THE NORTHERN GREAT LAKES. ED F && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-ILZ019- ILZ021-ILZ032-ILZ039...7 PM WEDNESDAY TO 1 PM THURSDAY. FLASH FLOOD WATCH...ILZ005-ILZ006-ILZ012-ILZ013-ILZ014-ILZ020- ILZ022-ILZ023-ILZ033...MIDNIGHT THURSDAY TO 1 PM THURSDAY. IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011- INZ019...MIDNIGHT THURSDAY TO 1 PM THURSDAY. LM...NONE. && $$ 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
235 PM CDT WED JUN 24 2015 .UPDATE... 1217 PM CDT ALL INDICATIONS THIS MORNING CONTINUE TO POINT TO A CLASSIC TYPE HEAVY RAIN EVENT ACROSS THE AREA. THE THREAT OF SEVERE THUNDERSTORMS IS ALSO DECENT WITH THIS ACTIVITY AS WELL LATER THIS EVENING...AND THIS PRIMARILY LOOKS TO BE IN THE FORM OF STRONG STRAIGHT LINE WINDS. SHOWERS...WITH SOME EMBEDDED THUNDERSTORMS CONTINUE TO WEAKEN OVER CENTRAL ILLINOIS AS THEY MOVE AWAY FROM THE BETTER FOCUS OF LAST NIGHTS LOW LEVEL JET. SATELLITE IMAGERY CONTINUES TO INDICATE CLOUD TOPS WARMING WITH THIS ACTIVITY...AND EVEN INDICATES SOME BREAKS IN THE CLOUDS OVER FAR NORTHERN ILLINOIS. FARTHER WEST...HOWEVER...AN AREA OF CONVECTION OVER EASTERN NE AND NEAR FAR WESTERN IOWA CONTINUES TO MAINTAIN ITSELF. IT IS CERTAINLY POSSIBLE THAT THIS ACTIVITY COULD CONTINUE TO MOVE EAST OVER IOWA INTO THIS AFTERNOON...THEN SHIFT MORE SOUTHEAST ALONG THE MLCAPE GRADIENT. THIS ACTIVITY...SHOULD IT MAINTAIN ITSELF THOUGH THE DAY...WOULD LIKELY MISS MOST OF MY AREA...POSSIBLY ONLY IMPACTING MY SOUTHWESTERN COUNTIES. SOME OF THE LATEST HRRR SOLUTIONS ARE IN LINE WITH THIS THINKING. OTHERWISE...THE FOCUS CONTINUES TO CENTER ON THIS EVENING THROUGH THE OVERNIGHT FOR THE POTENTIAL OF VERY HEAVY RAIN AND FLASH FLOODING. IT IS STILL ANTICIPATED THAT RENEWED CONVECTION WILL DEVELOP LATER THIS AFTERNOON/EARLY THIS EVENING OVER PORTIONS OF EASTERN IOWA INTO NORTHWESTERN ILLINOIS ALONG AND ON THE COOL SIDE OF A NORTHWARD MOVING WARM FRONTAL BOUNDARY. THIS ACTIVITY WOULD THEN LIKELY CONTINUE TO GROW UPSCALE AS RENEWED DEVELOPMENT CONTINUES UPSTREAM THANKS TO A PERSISTENT SOUTHWESTERLY 40+ KT LOW LEVEL JET CONTINUALLY REPLENISHING THE DEEP MOISTURE. THESE STORMS WILL OCCUR WITHIN AROUND A 2 INCH PRECIPITABLE WATER ENVIRONMENT...SO EXTREMELY HEAVY RAIN RATES WILL BE A HIGH CONCERN. ALSO...WITH CONTINUAL UPSTREAM DEVELOPMENT LOOKING LIKELY...TRAINING AND BACKBULDING OF CELLS COULD RESULT IN PROLONGED PERIODS OF THESE VERY HEAVY RAIN RATES OCCURRING OVER THE SAME AREAS. AS SUCH...SOME ISOLATED AREAS OVER THE AREA COULD EXPERIENCE 4-5+ INCH AMOUNTS OF RAIN BEFORE THIS ACTIVITY ABATES LATER TONIGHT OR EARLY THURSDAY MORNING. THERE ARE STILL SOME UNCERTAINTIES ON WHERE EXACTLY THE HEAVIEST RAINFALL AMOUNTS WILL FALL. HOWEVER...WITH THE ACTIVITY LIKELY TO MOVE EAST-SOUTHEAST WITH TIME...IT WOULD APPEAR THAT AREAS ALONG AND SOUTH OF INTERSTATE 88 WOULD LIKELY STAND THE BEST POTENTIAL TO EXPERIENCE RAINFALL AMOUNTS IN EXCESS OF 1 TO 2 INCHES. WITHIN THESE TRAINING THUNDERSTORMS...THE KINEMATIC FIELDS OVER THE AREA WILL ALSO LIKELY SUPPORT FORWARD PROPAGATING EAST-SOUTHEASTWARD MOVING BOWING SEGMENTS OVER THE AREA. THEREFORE...STRONG DAMAGING WINDS...PERHAPS IN EXCESS OF 70 MPH...WILL ALSO BE A THREAT WITH THESE STORMS. A TORNADO OR TWO CAN ALSO NOT BE RULED OUT. HOWEVER... THIS THREAT APPEARS TO BE THE HIGHEST OVER MY SOUTHEASTERN CWA THIS EVENING IN CLOSER PROXIMATELY TO THE APPROACHING WARM FRONTAL BOUNDARY. KJB && .SHORT TERM... 320 AM CDT THROUGH WEDNESDAY NIGHT... STRONG TO SEVERE THUNDERSTORMS COMPRISE THE PRIMARY FORECAST CONCERNS FOR TODAY AND TONIGHT. EARLY THIS MORNING...SURFACE HIGH PRESSURE IS CENTERED ACROSS CENTRAL ILLINOIS PROVIDING MOSTLY CLEAR SKIES AND LIGHT WINDS ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA. FARTHER WEST...A SURFACE TROUGH IS ANALYZED FROM NORTHERN KANSAS NE ACROSS THE MID- MISSOURI VALLEY INTO CENTRAL IOWA. WATER VAPOR IMAGERY SHOWS A SUBTLE/SHEARED WAVE EMBEDDED WITHIN THE MAINLY ZONAL FLOW ALOFT MOVING ACROSS NORTHERN IOWA WHERE NOCTURNAL THUNDERSTORMS HAVE DEVELOPED MAINLY FOCUSED ACROSS THE I-80 CORRIDOR IN IOWA. NAM/GFS INITIALIZE ON THIS AREA OF THUNDERSTORMS AND KEEPS THE FORCING FOCUSED TO THE WEST OF THE FORECAST AREA THROUGH MOST OF THE DAY TODAY...ALONG WITH THE INSTABILITY. CANT RULE OUT SOME DECAYING ELEVATED CONVECTION PROPAGATING INTO THE FORECAST AREA LATER TODAY...HOWEVER EXPECT MOST OF THE CWA TO BE DRY THIS MORNING INTO AT LEAST EARLY EVENING. WILL HAVE TO KEEP AN EYE ON HOW EARLY MORNING CONVECTION IMPACTS THE MOVEMENT OF THE WARM FRONT THROUGH THE DAY. THIS EVENING...SURFACE TROUGH/WARM FRONT IS PROGGED TO SETTLE ACROSS CENTRAL/NORTHERN IOWA INTO NORTHERN ILLINOIS THOUGH THERE ARE NOTABLE DIFFERENCES AT THIS POINT AS TO EXACTLY HOW FAR NORTH. VERY STRONG INSTABILITY IS EXPECTED TO DEVELOP SOUTH OF THE FRONT WITH THUNDERSTORMS EXPECTED TO REDEVELOP/RESTRENGTHEN ACROSS IOWA AFTERNOON INTO THE EVENING AS ANOTHER SHEARED VORT LOBE TRAVERSES ACROSS THE REGION AND RIGHT ENTRANCE REGION TO THE LOW LEVEL JET PROVIDES ADDITIONAL SYNOPTIC SCALE ASCENT. ASSUMING ATMOSPHERE EFFECTIVELY RECOVERS FROM MORNING CONVECTION...FAVORABLE SHEAR/INSTABILITY PROFILES...IMPRESSIVE CYCLONICALLY CURVED HODOGRAPHS AND WHAT SHOULD BE SUFFICIENT FORCING TO OVERCOME ANY CAPPING INVERSION WILL RESULT IN STRONG TO SEVERE THUNDERSTORMS DEVELOPING WEST OF THE CWA...POSSIBLY IN A DISCRETE/SUPERCELL MODE INITIALLY WITH THE FULL GAMUT OF SEVERE WEATHER POSSIBLE. STRENGTHENING NOCTURNAL LOW LEVEL JET INTO THE EVENING WILL RESULT IN STORMS MERGING INTO AN MCS AND PUSHING EAST INTO THE LOCAL FORECAST AREA. AS THIS OCCURS...EXPECT THE PRIMARY SEVERE THREAT TO CHANGE TO MORE OF A STRAIGHT LINE WIND DAMAGE AND FLOODING THREAT. CORFIDI VECTORS DROP OFF TO AROUND 5 KT OR SO ON THE SOUTHERN FLANK OF THE STORMS SO BACKBUILDING AND TRAINING THUNDERSTORMS REMAIN A CONCERN. A FLASH FLOOD WATCH WAS ISSUED YESTERDAY AND OPTED TO EXPAND NORTHWARD GIVEN THE TRENDS FROM THE GFS/NAM...ALTHOUGH CONFIDENCE IS ADMITTEDLY A BIT LOWER ACROSS THE NORTHERN TIER OF COUNTIES. DEUBELBEISS && .LONG TERM... 340 AM CDT THURSDAY THROUGH TUESDAY... THE UPPER LEVEL ZONAL FLOW FINALLY SHIFTS EAST LATE THIS WEEK AS AN UPPER LEVEL TROUGH MOVES OVER THE REGION FRIDAY NIGHT. THE TROUGH AXIS SHIFTS EAST SATURDAY WITH NORTHWEST FLOW SUNDAY. ANOTHER WEAKER TROUGH IS POSSIBLE EARLY NEXT WEEK. A SFC LOW WILL BE OVER NORTHERN IL AND NORTHWEST IN THURSDAY MORNING AS A DYING MCS SLOWLY SHIFTS EAST. RAISED QPF AMOUNTS THURSDAY MORNING AS THE DYING MCS SHOULD PRODUCE AT LEAST ANOTHER 0.35-0.5 INCHES OF RAIN SOUTH OF I-88. GUIDANCE DIFFERS ON HOW QUICKLY THE MCS WILL EXIT THE REGION...BUT HAVE HIGH CONFIDENCE IN DRY CONDITIONS THURSDAY NIGHT. SADLY THERE IS A VERY SMALL BREAK BEFORE THE NEXT LOW PRESSURE BRINGS MORE RAIN AND STORMS TO AREAS SOUTH OF I-80 FRIDAY. THE NEXT LOW FORMS OVER THE SOUTHERN PLAINS THURSDAY NIGHT. IT THEN PASSES OVER THE MID MISSISSIPPI VALLEY AND ALONG THE OHIO RIVER THROUGH SATURDAY NIGHT. IT LOOKS LIKE THE MAJORITY OF PRECIP WILL FALL OVER CENTRAL AND SOUTHERN IL...BUT KEPT A SLIGHT CHANCE TO CHANCE OF THUNDERSTORMS SOUTH OF I-88. WE FINALLY SEE A DRY SPELL LATE THIS WEEK AS THE LOW SHIFTS EAST AND HIGH PRESSURE SPREADS OVERHEAD. THE NEXT CHANCE OF RAIN AND STORMS ARRIVES EARLY NEXT WEEK AS AN UPPER LEVEL TROUGH SWINGS THROUGH. GUIDANCE DIFFERS ON HOW STRONG THE TROUGH WILL BE AND HOW FAR SOUTH IT WILL TRAVEL...BUT HAVE ENOUGH CONFIDENCE TO KEEP A CHANCE OF PRECIP IN THE FORECAST. WE COULD SEE MULTIPLE VORTICITY STREAMERS SWING THROUGH AS THE TROUGH SITS OVERHEAD SO KEPT A CHANCE OF PRECIP FROM SUNDAY NIGHT THROUGH TUESDAY. DESPITE THE CONSTANT CHANCE OF RAIN...ONLY EXPECTING PERIODS OF SHOWERS AND STORMS AT THIS POINT AND NOT COMPLETE RAIN OUTS. FOR TEMPS...THURSDAY LOOKS LIKE THE WARMEST DAY WITH HIGHS IN THE UPPER 70S TO LOW 80S. LAKE COOLING WILL KEEP LAKEFRONT LOCATIONS IN THE LOW 70S. COOLER AIR SINKS SOUTH THURSDAY NIGHT LEADING TO HIGH TEMPS FRIDAY IN THE 70S WITH 60S ALONG THE LAKE. A SLOW WARM UP IS EXPECTED WITH HIGHS BACK IN THE LOW 80S TUESDAY. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * CHANCE OF LAKE BREEZE DEVELOPMENT LATE THIS AFTERNOON. * THUNDERSTORMS LIKELY OVERNIGHT TONIGHT...MVFR-IFR CIGS/VIS LIKELY. KREIN //DISCUSSION...UPDATED 18Z... AT THE SURFACE...A LARGE AREA OF HIGH PRESSURE IS CENTERED ALONG THE IN/OH BORDER AS A MID LEVEL IMPULSE CROSSING THE MIDDLE MISSISSIPPI VALLEY IS BRINGING AN AREA OF SHOWERS AND THUNDERSTORMS FROM IOWA THROUGH CENTRAL IL TO CENTRAL IN. BASED ON THE LATEST RADAR TRENDS...EXPECT THAT ANY PCPN AND TS SHOULD REMAIN SOUTH OF OF THE TERMINALS EARLY THIS EVENING...THROUGH IT COULD CLIP THE SOUTHERN PORTIONS OF THE C90 TRACON AREA. AS THE CENTER OF THE HIGH CONTINUES TO SHIFT TO THE EAST...WINDS HAVE BECOME SSWLY AND ARE INCREASING TO ARND 10KT. LATEST RADAR IMAGERY AND COASTAL OBSERVATIONS SHOW A LAKE BREEZE MOVING ONSHORE NEAR KUGN...BUT THERE IS LITTLE WESTWARD PROGRESSION AND DO NOT EXPECT THAT THE BOUNDARY WILL REACH AS FAR WEST AS ORD/MDW. RATHER...EXPECT THAT WINDS WILL GRADUALLY BACK TO MORE SELY THROUGH THE AFTERNOON AND INTO THE EVENING IN RESPONSE TO THE LARGER SCALE PRESSURE PATTERN WITH THE HIGH MOVING OFF TO THE EAST AND LOW PRESSURE DEVELOPING OVER THE CNTRL PLAINS. THE OTHER CONCERN FOR THE PERIOD WILL BE TIMING THE NEXT ROUND OF THUNDERSTORMS TO IMPACT THE REGION. WHILE THE ONGOING PCPN SHOULD REMAIN SOUTH OF THE TERMINALS...CONFIDENCE IS HIGHER THAT ANOTHER ROUND OF THUNDERSTORMS WILL DEVELOP TONIGHT OVER THE CNTRL PLAINS/IOWA AND THEN TRACK EASTWARD. LATEST GUIDANCE IS A LITTLE FASTER THAN PREVIOUS MODEL RUNS AND SUGGESTS THAT TS COULD REACH RFD BY ARND 03Z...AND THEN QUICKLY PUSHING TO THE EAST ACROSS THE CHICAGO AREA TERMINALS. WHILE CONFIDENCE IS RELATIVELY HIGH IN TS IMPACTING THE TERMINALS OVERNIGHT TONIGHT...TIMING AND DURATION IS A LITTLE LOWER. ALSO...AS THE MAIN SFC LOW TRACKS ALONG A DEVELOPING WARM FRONT EXPECTED TO SET THROUGH CNTRL OR NRN IL/IN AND WITH UPPER LEVEL FLOW SETTING UP TO BE PARALLEL TO THE SFC FRONT...AN EXTENDED PERIOD OF TSRA IMPACTING THE TERMINALS IS QUITE POSSIBLE OVERNIGHT AND POSSIBLY EVEN INTO TOMORROW MORNING. KREIN //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM TO HIGH CONFIDENCE IN GENERAL WIND TRENDS. * MEDIUM CONFIDENCE IN LAKE BREEZE DETAILS...AND THAT THE LAKE BREEZE BOUNDARY WILL REMAIN EAST OF THE TERMINALS. * MEDIUM TO HIGH CONFIDENCE IN TS IMPACTING THE TERMINALS THIS EVENING AND TONIGHT...LOWER CONFIDENCE IN EXACT TIMING AND DURATION. * MEDIUM CONFIDENCE IN A PERIOD OF MVFR-IFR CIGS/VIS WITH THE TSRA/PCPN OVERNIGHT TONIGHT AND INTO TOMORROW MORNING. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. WX NIL. NELY WINDS. FRIDAY...VFR. WX NIL. NELY WINDS. SATURDAY...VFR. WX NIL. NELY WINDS BACKING NWLY LATE. SUNDAY...CHANCE TSRA. MVFR POSSIBLE. NWLY WINDS BACKING SWLY. MONDAY...CHANCE TSRA. MVFR POSSIBLE. SWLY WINDS VEERING NWLY TUESDAY...SLIGHT CHANCE TSRA. VRBL WINDS. KREIN && .MARINE... 410 AM CDT HIGH PRESSURE IS OVER THE REGION WITH LIGHT SOUTHWEST WINDS. WINDS REMAIN LIGHT AND BECOME EAST THURSDAY MORNING AS A LOW PRESSURE SYSTEM MOVES OVER THE SOUTHERN END OF THE LAKE. GUIDANCE DIFFERS ON HOW STRONG THE LOW WILL BE SO WIND SPEEDS COULD BE STRONGER OVER THE SOUTHERN END OF THE LAKE IF THE LOW IS STRONGER. THE LOW SHIFTS EAST AND ANOTHER LOW PASSES WELL SOUTH OF THE LAKE OVER THE OHIO RIVER LATE THIS WEEK. PERSISTENT NORTH TO NORTHEAST WINDS AT 20KT OR LESS ARE EXPECTED THROUGH SATURDAY NIGHT. HIGH PRESSURE SPREADS SOUTH OF THE LAKE WHILE A LOW SPREADS OVER THE LAKE SUNDAY NIGHT WITH WINDS BCMG SOUTH SUNDAY EVENING AND REMAINING SOUTH TO SOUTHWEST THROUGH MONDAY NIGHT. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022- ILZ023-ILZ032-ILZ033-ILZ039...7 PM WEDNESDAY TO 1 PM THURSDAY. IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019...7 PM WEDNESDAY TO 1 PM THURSDAY. LM...NONE. && $$ 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
1238 PM CDT WED JUN 24 2015 .UPDATE... 1217 PM CDT ALL INDICATIONS THIS MORNING CONTINUE TO POINT TO A CLASSIC TYPE HEAVY RAIN EVENT ACROSS THE AREA. THE THREAT OF SEVERE THUNDERSTORMS IS ALSO DECENT WITH THIS ACTIVITY AS WELL LATER THIS EVENING...AND THIS PRIMARILY LOOKS TO BE IN THE FORM OF STRONG STRAIGHT LINE WINDS. SHOWERS...WITH SOME EMBEDDED THUNDERSTORMS CONTINUE TO WEAKEN OVER CENTRAL ILLINOIS AS THEY MOVE AWAY FROM THE BETTER FOCUS OF LAST NIGHTS LOW LEVEL JET. SATELLITE IMAGERY CONTINUES TO INDICATE CLOUD TOPS WARMING WITH THIS ACTIVITY...AND EVEN INDICATES SOME BREAKS IN THE CLOUDS OVER FAR NORTHERN ILLINOIS. FARTHER WEST...HOWEVER...AN AREA OF CONVECTION OVER EASTERN NE AND NEAR FAR WESTERN IOWA CONTINUES TO MAINTAIN ITSELF. IT IS CERTAINLY POSSIBLE THAT THIS ACTIVITY COULD CONTINUE TO MOVE EAST OVER IOWA INTO THIS AFTERNOON...THEN SHIFT MORE SOUTHEAST ALONG THE MLCAPE GRADIENT. THIS ACTIVITY...SHOULD IT MAINTAIN ITSELF THOUGH THE DAY...WOULD LIKELY MISS MOST OF MY AREA...POSSIBLY ONLY IMPACTING MY SOUTHWESTERN COUNTIES. SOME OF THE LATEST HRRR SOLUTIONS ARE IN LINE WITH THIS THINKING. OTHERWISE...THE FOCUS CONTINUES TO CENTER ON THIS EVENING THROUGH THE OVERNIGHT FOR THE POTENTIAL OF VERY HEAVY RAIN AND FLASH FLOODING. IT IS STILL ANTICIPATED THAT RENEWED CONVECTION WILL DEVELOP LATER THIS AFTERNOON/EARLY THIS EVENING OVER PORTIONS OF EASTERN IOWA INTO NORTHWESTERN ILLINOIS ALONG AND ON THE COOL SIDE OF A NORTHWARD MOVING WARM FRONTAL BOUNDARY. THIS ACTIVITY WOULD THEN LIKELY CONTINUE TO GROW UPSCALE AS RENEWED DEVELOPMENT CONTINUES UPSTREAM THANKS TO A PERSISTENT SOUTHWESTERLY 40+ KT LOW LEVEL JET CONTINUALLY REPLENISHING THE DEEP MOISTURE. THESE STORMS WILL OCCUR WITHIN AROUND A 2 INCH PRECIPITABLE WATER ENVIRONMENT...SO EXTREMELY HEAVY RAIN RATES WILL BE A HIGH CONCERN. ALSO...WITH CONTINUAL UPSTREAM DEVELOPMENT LOOKING LIKELY...TRAINING AND BACKBULDING OF CELLS COULD RESULT IN PROLONGED PERIODS OF THESE VERY HEAVY RAIN RATES OCCURRING OVER THE SAME AREAS. AS SUCH...SOME ISOLATED AREAS OVER THE AREA COULD EXPERIENCE 4-5+ INCH AMOUNTS OF RAIN BEFORE THIS ACTIVITY ABATES LATER TONIGHT OR EARLY THURSDAY MORNING. THERE ARE STILL SOME UNCERTAINTIES ON WHERE EXACTLY THE HEAVIEST RAINFALL AMOUNTS WILL FALL. HOWEVER...WITH THE ACTIVITY LIKELY TO MOVE EAST-SOUTHEAST WITH TIME...IT WOULD APPEAR THAT AREAS ALONG AND SOUTH OF INTERSTATE 88 WOULD LIKELY STAND THE BEST POTENTIAL TO EXPERIENCE RAINFALL AMOUNTS IN EXCESS OF 1 TO 2 INCHES. WITHIN THESE TRAINING THUNDERSTORMS...THE KINEMATIC FIELDS OVER THE AREA WILL ALSO LIKELY SUPPORT FORWARD PROPAGATING EAST-SOUTHEASTWARD MOVING BOWING SEGMENTS OVER THE AREA. THEREFORE...STRONG DAMAGING WINDS...PERHAPS IN EXCESS OF 70 MPH...WILL ALSO BE A THREAT WITH THESE STORMS. A TORNADO OR TWO CAN ALSO NOT BE RULED OUT. HOWEVER... THIS THREAT APPEARS TO BE THE HIGHEST OVER MY SOUTHEASTERN CWA THIS EVENING IN CLOSER PROXIMATELY TO THE APPROACHING WARM FRONTAL BOUNDARY. KJB && .SHORT TERM... 320 AM CDT THROUGH WEDNESDAY NIGHT... STRONG TO SEVERE THUNDERSTORMS COMPRISE THE PRIMARY FORECAST CONCERNS FOR TODAY AND TONIGHT. EARLY THIS MORNING...SURFACE HIGH PRESSURE IS CENTERED ACROSS CENTRAL ILLINOIS PROVIDING MOSTLY CLEAR SKIES AND LIGHT WINDS ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA. FARTHER WEST...A SURFACE TROUGH IS ANALYZED FROM NORTHERN KANSAS NE ACROSS THE MID- MISSOURI VALLEY INTO CENTRAL IOWA. WATER VAPOR IMAGERY SHOWS A SUBTLE/SHEARED WAVE EMBEDDED WITHIN THE MAINLY ZONAL FLOW ALOFT MOVING ACROSS NORTHERN IOWA WHERE NOCTURNAL THUNDERSTORMS HAVE DEVELOPED MAINLY FOCUSED ACROSS THE I-80 CORRIDOR IN IOWA. NAM/GFS INITIALIZE ON THIS AREA OF THUNDERSTORMS AND KEEPS THE FORCING FOCUSED TO THE WEST OF THE FORECAST AREA THROUGH MOST OF THE DAY TODAY...ALONG WITH THE INSTABILITY. CANT RULE OUT SOME DECAYING ELEVATED CONVECTION PROPAGATING INTO THE FORECAST AREA LATER TODAY...HOWEVER EXPECT MOST OF THE CWA TO BE DRY THIS MORNING INTO AT LEAST EARLY EVENING. WILL HAVE TO KEEP AN EYE ON HOW EARLY MORNING CONVECTION IMPACTS THE MOVEMENT OF THE WARM FRONT THROUGH THE DAY. THIS EVENING...SURFACE TROUGH/WARM FRONT IS PROGGED TO SETTLE ACROSS CENTRAL/NORTHERN IOWA INTO NORTHERN ILLINOIS THOUGH THERE ARE NOTABLE DIFFERENCES AT THIS POINT AS TO EXACTLY HOW FAR NORTH. VERY STRONG INSTABILITY IS EXPECTED TO DEVELOP SOUTH OF THE FRONT WITH THUNDERSTORMS EXPECTED TO REDEVELOP/RESTRENGTHEN ACROSS IOWA AFTERNOON INTO THE EVENING AS ANOTHER SHEARED VORT LOBE TRAVERSES ACROSS THE REGION AND RIGHT ENTRANCE REGION TO THE LOW LEVEL JET PROVIDES ADDITIONAL SYNOPTIC SCALE ASCENT. ASSUMING ATMOSPHERE EFFECTIVELY RECOVERS FROM MORNING CONVECTION...FAVORABLE SHEAR/INSTABILITY PROFILES...IMPRESSIVE CYCLONICALLY CURVED HODOGRAPHS AND WHAT SHOULD BE SUFFICIENT FORCING TO OVERCOME ANY CAPPING INVERSION WILL RESULT IN STRONG TO SEVERE THUNDERSTORMS DEVELOPING WEST OF THE CWA...POSSIBLY IN A DISCRETE/SUPERCELL MODE INITIALLY WITH THE FULL GAMUT OF SEVERE WEATHER POSSIBLE. STRENGTHENING NOCTURNAL LOW LEVEL JET INTO THE EVENING WILL RESULT IN STORMS MERGING INTO AN MCS AND PUSHING EAST INTO THE LOCAL FORECAST AREA. AS THIS OCCURS...EXPECT THE PRIMARY SEVERE THREAT TO CHANGE TO MORE OF A STRAIGHT LINE WIND DAMAGE AND FLOODING THREAT. CORFIDI VECTORS DROP OFF TO AROUND 5 KT OR SO ON THE SOUTHERN FLANK OF THE STORMS SO BACKBUILDING AND TRAINING THUNDERSTORMS REMAIN A CONCERN. A FLASH FLOOD WATCH WAS ISSUED YESTERDAY AND OPTED TO EXPAND NORTHWARD GIVEN THE TRENDS FROM THE GFS/NAM...ALTHOUGH CONFIDENCE IS ADMITTEDLY A BIT LOWER ACROSS THE NORTHERN TIER OF COUNTIES. DEUBELBEISS && .LONG TERM... 340 AM CDT THURSDAY THROUGH TUESDAY... THE UPPER LEVEL ZONAL FLOW FINALLY SHIFTS EAST LATE THIS WEEK AS AN UPPER LEVEL TROUGH MOVES OVER THE REGION FRIDAY NIGHT. THE TROUGH AXIS SHIFTS EAST SATURDAY WITH NORTHWEST FLOW SUNDAY. ANOTHER WEAKER TROUGH IS POSSIBLE EARLY NEXT WEEK. A SFC LOW WILL BE OVER NORTHERN IL AND NORTHWEST IN THURSDAY MORNING AS A DYING MCS SLOWLY SHIFTS EAST. RAISED QPF AMOUNTS THURSDAY MORNING AS THE DYING MCS SHOULD PRODUCE AT LEAST ANOTHER 0.35-0.5 INCHES OF RAIN SOUTH OF I-88. GUIDANCE DIFFERS ON HOW QUICKLY THE MCS WILL EXIT THE REGION...BUT HAVE HIGH CONFIDENCE IN DRY CONDITIONS THURSDAY NIGHT. SADLY THERE IS A VERY SMALL BREAK BEFORE THE NEXT LOW PRESSURE BRINGS MORE RAIN AND STORMS TO AREAS SOUTH OF I-80 FRIDAY. THE NEXT LOW FORMS OVER THE SOUTHERN PLAINS THURSDAY NIGHT. IT THEN PASSES OVER THE MID MISSISSIPPI VALLEY AND ALONG THE OHIO RIVER THROUGH SATURDAY NIGHT. IT LOOKS LIKE THE MAJORITY OF PRECIP WILL FALL OVER CENTRAL AND SOUTHERN IL...BUT KEPT A SLIGHT CHANCE TO CHANCE OF THUNDERSTORMS SOUTH OF I-88. WE FINALLY SEE A DRY SPELL LATE THIS WEEK AS THE LOW SHIFTS EAST AND HIGH PRESSURE SPREADS OVERHEAD. THE NEXT CHANCE OF RAIN AND STORMS ARRIVES EARLY NEXT WEEK AS AN UPPER LEVEL TROUGH SWINGS THROUGH. GUIDANCE DIFFERS ON HOW STRONG THE TROUGH WILL BE AND HOW FAR SOUTH IT WILL TRAVEL...BUT HAVE ENOUGH CONFIDENCE TO KEEP A CHANCE OF PRECIP IN THE FORECAST. WE COULD SEE MULTIPLE VORTICITY STREAMERS SWING THROUGH AS THE TROUGH SITS OVERHEAD SO KEPT A CHANCE OF PRECIP FROM SUNDAY NIGHT THROUGH TUESDAY. DESPITE THE CONSTANT CHANCE OF RAIN...ONLY EXPECTING PERIODS OF SHOWERS AND STORMS AT THIS POINT AND NOT COMPLETE RAIN OUTS. FOR TEMPS...THURSDAY LOOKS LIKE THE WARMEST DAY WITH HIGHS IN THE UPPER 70S TO LOW 80S. LAKE COOLING WILL KEEP LAKEFRONT LOCATIONS IN THE LOW 70S. COOLER AIR SINKS SOUTH THURSDAY NIGHT LEADING TO HIGH TEMPS FRIDAY IN THE 70S WITH 60S ALONG THE LAKE. A SLOW WARM UP IS EXPECTED WITH HIGHS BACK IN THE LOW 80S TUESDAY. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * CHANCE OF LAKE BREEZE DEVELOPMENT LATE THIS AFTERNOON. * THUNDERSTORMS LIKELY OVERNIGHT TONIGHT...MVFR-IFR CIGS/VIS LIKELY. KREIN //DISCUSSION...UPDATED 18Z... AT THE SURFACE...A LARGE AREA OF HIGH PRESSURE IS CENTERED ALONG THE IN/OH BORDER AS A MID LEVEL IMPULSE CROSSING THE MIDDLE MISSISSIPPI VALLEY IS BRINGING AN AREA OF SHOWERS AND THUNDERSTORMS FROM IOWA THROUGH CENTRAL IL TO CENTRAL IN. BASED ON THE LATEST RADAR TRENDS...EXPECT THAT ANY PCPN AND TS SHOULD REMAIN SOUTH OF OF THE TERMINALS EARLY THIS EVENING...THROUGH IT COULD CLIP THE SOUTHERN PORTIONS OF THE C90 TRACON AREA. AS THE CENTER OF THE HIGH CONTINUES TO SHIFT TO THE EAST...WINDS HAVE BECOME SSWLY AND ARE INCREASING TO ARND 10KT. LATEST RADAR IMAGERY AND COASTAL OBSERVATIONS SHOW A LAKE BREEZE MOVING ONSHORE NEAR KUGN...BUT THERE IS LITTLE WESTWARD PROGRESSION AND DO NOT EXPECT THAT THE BOUNDARY WILL REACH AS FAR WEST AS ORD/MDW. RATHER...EXPECT THAT WINDS WILL GRADUALLY BACK TO MORE SELY THROUGH THE AFTERNOON AND INTO THE EVENING IN RESPONSE TO THE LARGER SCALE PRESSURE PATTERN WITH THE HIGH MOVING OFF TO THE EAST AND LOW PRESSURE DEVELOPING OVER THE CNTRL PLAINS. THE OTHER CONCERN FOR THE PERIOD WILL BE TIMING THE NEXT ROUND OF THUNDERSTORMS TO IMPACT THE REGION. WHILE THE ONGOING PCPN SHOULD REMAIN SOUTH OF THE TERMINALS...CONFIDENCE IS HIGHER THAT ANOTHER ROUND OF THUNDERSTORMS WILL DEVELOP TONIGHT OVER THE CNTRL PLAINS/IOWA AND THEN TRACK EASTWARD. LATEST GUIDANCE IS A LITTLE FASTER THAN PREVIOUS MODEL RUNS AND SUGGESTS THAT TS COULD REACH RFD BY ARND 03Z...AND THEN QUICKLY PUSHING TO THE EAST ACROSS THE CHICAGO AREA TERMINALS. WHILE CONFIDENCE IS RELATIVELY HIGH IN TS IMPACTING THE TERMINALS OVERNIGHT TONIGHT...TIMING AND DURATION IS A LITTLE LOWER. ALSO...AS THE MAIN SFC LOW TRACKS ALONG A DEVELOPING WARM FRONT EXPECTED TO SET THROUGH CNTRL OR NRN IL/IN AND WITH UPPER LEVEL FLOW SETTING UP TO BE PARALLEL TO THE SFC FRONT...AN EXTENDED PERIOD OF TSRA IMPACTING THE TERMINALS IS QUITE POSSIBLE OVERNIGHT AND POSSIBLY EVEN INTO TOMORROW MORNING. KREIN //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM TO HIGH CONFIDENCE IN GENERAL WIND TRENDS. * MEDIUM CONFIDENCE IN LAKE BREEZE DETAILS...AND THAT THE LAKE BREEZE BOUNDARY WILL REMAIN EAST OF THE TERMINALS. * MEDIUM TO HIGH CONFIDENCE IN TS IMPACTING THE TERMINALS THIS EVENING AND TONIGHT...LOWER CONFIDENCE IN EXACT TIMING AND DURATION. * MEDIUM CONFIDENCE IN A PERIOD OF MVFR-IFR CIGS/VIS WITH THE TSRA/PCPN OVERNIGHT TONIGHT AND INTO TOMORROW MORNING. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. WX NIL. NELY WINDS. FRIDAY...VFR. WX NIL. NELY WINDS. SATURDAY...VFR. WX NIL. NELY WINDS BACKING NWLY LATE. SUNDAY...CHANCE TSRA. MVFR POSSIBLE. NWLY WINDS BACKING SWLY. MONDAY...CHANCE TSRA. MVFR POSSIBLE. SWLY WINDS VEERING NWLY TUESDAY...SLIGHT CHANCE TSRA. VRBL WINDS. KREIN && .MARINE... 410 AM CDT HIGH PRESSURE IS OVER THE REGION WITH LIGHT SOUTHWEST WINDS. WINDS REMAIN LIGHT AND BECOME EAST THURSDAY MORNING AS A LOW PRESSURE SYSTEM MOVES OVER THE SOUTHERN END OF THE LAKE. GUIDANCE DIFFERS ON HOW STRONG THE LOW WILL BE SO WIND SPEEDS COULD BE STRONGER OVER THE SOUTHERN END OF THE LAKE IF THE LOW IS STRONGER. THE LOW SHIFTS EAST AND ANOTHER LOW PASSES WELL SOUTH OF THE LAKE OVER THE OHIO RIVER LATE THIS WEEK. PERSISTENT NORTH TO NORTHEAST WINDS AT 20KT OR LESS ARE EXPECTED THROUGH SATURDAY NIGHT. HIGH PRESSURE SPREADS SOUTH OF THE LAKE WHILE A LOW SPREADS OVER THE LAKE SUNDAY NIGHT WITH WINDS BCMG SOUTH SUNDAY EVENING AND REMAINING SOUTH TO SOUTHWEST THROUGH MONDAY NIGHT. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022- ILZ023-ILZ032-ILZ033-ILZ039...7 PM WEDNESDAY TO 1 PM THURSDAY. IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019...7 PM WEDNESDAY TO 1 PM THURSDAY. LM...NONE. && $$ 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
1218 PM CDT WED JUN 24 2015 .UPDATE... 1217 PM CDT ALL INDICATIONS THIS MORNING CONTINUE TO POINT TO A CLASSIC TYPE HEAVY RAIN EVENT ACROSS THE AREA. THE THREAT OF SEVERE THUNDERSTORMS IS ALSO DECENT WITH THIS ACTIVITY AS WELL LATER THIS EVENING...AND THIS PRIMARILY LOOKS TO BE IN THE FORM OF STRONG STRAIGHT LINE WINDS. SHOWERS...WITH SOME EMBEDDED THUNDERSTORMS CONTINUE TO WEAKEN OVER CENTRAL ILLINOIS AS THEY MOVE AWAY FROM THE BETTER FOCUS OF LAST NIGHTS LOW LEVEL JET. SATELLITE IMAGERY CONTINUES TO INDICATE CLOUD TOPS WARMING WITH THIS ACTIVITY...AND EVEN INDICATES SOME BREAKS IN THE CLOUDS OVER FAR NORTHERN ILLINOIS. FARTHER WEST...HOWEVER...AN AREA OF CONVECTION OVER EASTERN NE AND NEAR FAR WESTERN IOWA CONTINUES TO MAINTAIN ITSELF. IT IS CERTAINLY POSSIBLE THAT THIS ACTIVITY COULD CONTINUE TO MOVE EAST OVER IOWA INTO THIS AFTERNOON...THEN SHIFT MORE SOUTHEAST ALONG THE MLCAPE GRADIENT. THIS ACTIVITY...SHOULD IT MAINTAIN ITSELF THOUGH THE DAY...WOULD LIKELY MISS MOST OF MY AREA...POSSIBLY ONLY IMPACTING MY SOUTHWESTERN COUNTIES. SOME OF THE LATEST HRRR SOLUTIONS ARE IN LINE WITH THIS THINKING. OTHERWISE...THE FOCUS CONTINUES TO CENTER ON THIS EVENING THROUGH THE OVERNIGHT FOR THE POTENTIAL OF VERY HEAVY RAIN AND FLASH FLOODING. IT IS STILL ANTICIPATED THAT RENEWED CONVECTION WILL DEVELOP LATER THIS AFTERNOON/EARLY THIS EVENING OVER PORTIONS OF EASTERN IOWA INTO NORTHWESTERN ILLINOIS ALONG AND ON THE COOL SIDE OF A NORTHWARD MOVING WARM FRONTAL BOUNDARY. THIS ACTIVITY WOULD THEN LIKELY CONTINUE TO GROW UPSCALE AS RENEWED DEVELOPMENT CONTINUES UPSTREAM THANKS TO A PERSISTENT SOUTHWESTERLY 40+ KT LOW LEVEL JET CONTINUALLY REPLENISHING THE DEEP MOISTURE. THESE STORMS WILL OCCUR WITHIN AROUND A 2 INCH PRECIPITABLE WATER ENVIRONMENT...SO EXTREMELY HEAVY RAIN RATES WILL BE A HIGH CONCERN. ALSO...WITH CONTINUAL UPSTREAM DEVELOPMENT LOOKING LIKELY...TRAINING AND BACKBULDING OF CELLS COULD RESULT IN PROLONGED PERIODS OF THESE VERY HEAVY RAIN RATES OCCURRING OVER THE SAME AREAS. AS SUCH...SOME ISOLATED AREAS OVER THE AREA COULD EXPERIENCE 4-5+ INCH AMOUNTS OF RAIN BEFORE THIS ACTIVITY ABATES LATER TONIGHT OR EARLY THURSDAY MORNING. THERE ARE STILL SOME UNCERTAINTIES ON WHERE EXACTLY THE HEAVIEST RAINFALL AMOUNTS WILL FALL. HOWEVER...WITH THE ACTIVITY LIKELY TO MOVE EAST-SOUTHEAST WITH TIME...IT WOULD APPEAR THAT AREAS ALONG AND SOUTH OF INTERSTATE 88 WOULD LIKELY STAND THE BEST POTENTIAL TO EXPERIENCE RAINFALL AMOUNTS IN EXCESS OF 1 TO 2 INCHES. WITHIN THESE TRAINING THUNDERSTORMS...THE KINEMATIC FIELDS OVER THE AREA WILL ALSO LIKELY SUPPORT FORWARD PROPAGATING EAST-SOUTHEASTWARD MOVING BOWING SEGMENTS OVER THE AREA. THEREFORE...STRONG DAMAGING WINDS...PERHAPS IN EXCESS OF 70 MPH...WILL ALSO BE A THREAT WITH THESE STORMS. A TORNADO OR TWO CAN ALSO NOT BE RULED OUT. HOWEVER... THIS THREAT APPEARS TO BE THE HIGHEST OVER MY SOUTHEASTERN CWA THIS EVENING IN CLOSER PROXIMATELY TO THE APPROACHING WARM FRONTAL BOUNDARY. KJB && .SHORT TERM... 320 AM CDT THROUGH WEDNESDAY NIGHT... STRONG TO SEVERE THUNDERSTORMS COMPRISE THE PRIMARY FORECAST CONCERNS FOR TODAY AND TONIGHT. EARLY THIS MORNING...SURFACE HIGH PRESSURE IS CENTERED ACROSS CENTRAL ILLINOIS PROVIDING MOSTLY CLEAR SKIES AND LIGHT WINDS ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA. FARTHER WEST...A SURFACE TROUGH IS ANALYZED FROM NORTHERN KANSAS NE ACROSS THE MID- MISSOURI VALLEY INTO CENTRAL IOWA. WATER VAPOR IMAGERY SHOWS A SUBTLE/SHEARED WAVE EMBEDDED WITHIN THE MAINLY ZONAL FLOW ALOFT MOVING ACROSS NORTHERN IOWA WHERE NOCTURNAL THUNDERSTORMS HAVE DEVELOPED MAINLY FOCUSED ACROSS THE I-80 CORRIDOR IN IOWA. NAM/GFS INITIALIZE ON THIS AREA OF THUNDERSTORMS AND KEEPS THE FORCING FOCUSED TO THE WEST OF THE FORECAST AREA THROUGH MOST OF THE DAY TODAY...ALONG WITH THE INSTABILITY. CANT RULE OUT SOME DECAYING ELEVATED CONVECTION PROPAGATING INTO THE FORECAST AREA LATER TODAY...HOWEVER EXPECT MOST OF THE CWA TO BE DRY THIS MORNING INTO AT LEAST EARLY EVENING. WILL HAVE TO KEEP AN EYE ON HOW EARLY MORNING CONVECTION IMPACTS THE MOVEMENT OF THE WARM FRONT THROUGH THE DAY. THIS EVENING...SURFACE TROUGH/WARM FRONT IS PROGGED TO SETTLE ACROSS CENTRAL/NORTHERN IOWA INTO NORTHERN ILLINOIS THOUGH THERE ARE NOTABLE DIFFERENCES AT THIS POINT AS TO EXACTLY HOW FAR NORTH. VERY STRONG INSTABILITY IS EXPECTED TO DEVELOP SOUTH OF THE FRONT WITH THUNDERSTORMS EXPECTED TO REDEVELOP/RESTRENGTHEN ACROSS IOWA AFTERNOON INTO THE EVENING AS ANOTHER SHEARED VORT LOBE TRAVERSES ACROSS THE REGION AND RIGHT ENTRANCE REGION TO THE LOW LEVEL JET PROVIDES ADDITIONAL SYNOPTIC SCALE ASCENT. ASSUMING ATMOSPHERE EFFECTIVELY RECOVERS FROM MORNING CONVECTION...FAVORABLE SHEAR/INSTABILITY PROFILES...IMPRESSIVE CYCLONICALLY CURVED HODOGRAPHS AND WHAT SHOULD BE SUFFICIENT FORCING TO OVERCOME ANY CAPPING INVERSION WILL RESULT IN STRONG TO SEVERE THUNDERSTORMS DEVELOPING WEST OF THE CWA...POSSIBLY IN A DISCRETE/SUPERCELL MODE INITIALLY WITH THE FULL GAMUT OF SEVERE WEATHER POSSIBLE. STRENGTHENING NOCTURNAL LOW LEVEL JET INTO THE EVENING WILL RESULT IN STORMS MERGING INTO AN MCS AND PUSHING EAST INTO THE LOCAL FORECAST AREA. AS THIS OCCURS...EXPECT THE PRIMARY SEVERE THREAT TO CHANGE TO MORE OF A STRAIGHT LINE WIND DAMAGE AND FLOODING THREAT. CORFIDI VECTORS DROP OFF TO AROUND 5 KT OR SO ON THE SOUTHERN FLANK OF THE STORMS SO BACKBUILDING AND TRAINING THUNDERSTORMS REMAIN A CONCERN. A FLASH FLOOD WATCH WAS ISSUED YESTERDAY AND OPTED TO EXPAND NORTHWARD GIVEN THE TRENDS FROM THE GFS/NAM...ALTHOUGH CONFIDENCE IS ADMITTEDLY A BIT LOWER ACROSS THE NORTHERN TIER OF COUNTIES. DEUBELBEISS && .LONG TERM... 340 AM CDT THURSDAY THROUGH TUESDAY... THE UPPER LEVEL ZONAL FLOW FINALLY SHIFTS EAST LATE THIS WEEK AS AN UPPER LEVEL TROUGH MOVES OVER THE REGION FRIDAY NIGHT. THE TROUGH AXIS SHIFTS EAST SATURDAY WITH NORTHWEST FLOW SUNDAY. ANOTHER WEAKER TROUGH IS POSSIBLE EARLY NEXT WEEK. A SFC LOW WILL BE OVER NORTHERN IL AND NORTHWEST IN THURSDAY MORNING AS A DYING MCS SLOWLY SHIFTS EAST. RAISED QPF AMOUNTS THURSDAY MORNING AS THE DYING MCS SHOULD PRODUCE AT LEAST ANOTHER 0.35-0.5 INCHES OF RAIN SOUTH OF I-88. GUIDANCE DIFFERS ON HOW QUICKLY THE MCS WILL EXIT THE REGION...BUT HAVE HIGH CONFIDENCE IN DRY CONDITIONS THURSDAY NIGHT. SADLY THERE IS A VERY SMALL BREAK BEFORE THE NEXT LOW PRESSURE BRINGS MORE RAIN AND STORMS TO AREAS SOUTH OF I-80 FRIDAY. THE NEXT LOW FORMS OVER THE SOUTHERN PLAINS THURSDAY NIGHT. IT THEN PASSES OVER THE MID MISSISSIPPI VALLEY AND ALONG THE OHIO RIVER THROUGH SATURDAY NIGHT. IT LOOKS LIKE THE MAJORITY OF PRECIP WILL FALL OVER CENTRAL AND SOUTHERN IL...BUT KEPT A SLIGHT CHANCE TO CHANCE OF THUNDERSTORMS SOUTH OF I-88. WE FINALLY SEE A DRY SPELL LATE THIS WEEK AS THE LOW SHIFTS EAST AND HIGH PRESSURE SPREADS OVERHEAD. THE NEXT CHANCE OF RAIN AND STORMS ARRIVES EARLY NEXT WEEK AS AN UPPER LEVEL TROUGH SWINGS THROUGH. GUIDANCE DIFFERS ON HOW STRONG THE TROUGH WILL BE AND HOW FAR SOUTH IT WILL TRAVEL...BUT HAVE ENOUGH CONFIDENCE TO KEEP A CHANCE OF PRECIP IN THE FORECAST. WE COULD SEE MULTIPLE VORTICITY STREAMERS SWING THROUGH AS THE TROUGH SITS OVERHEAD SO KEPT A CHANCE OF PRECIP FROM SUNDAY NIGHT THROUGH TUESDAY. DESPITE THE CONSTANT CHANCE OF RAIN...ONLY EXPECTING PERIODS OF SHOWERS AND STORMS AT THIS POINT AND NOT COMPLETE RAIN OUTS. FOR TEMPS...THURSDAY LOOKS LIKE THE WARMEST DAY WITH HIGHS IN THE UPPER 70S TO LOW 80S. LAKE COOLING WILL KEEP LAKEFRONT LOCATIONS IN THE LOW 70S. COOLER AIR SINKS SOUTH THURSDAY NIGHT LEADING TO HIGH TEMPS FRIDAY IN THE 70S WITH 60S ALONG THE LAKE. A SLOW WARM UP IS EXPECTED WITH HIGHS BACK IN THE LOW 80S TUESDAY. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * CHANCE OF LAKE BREEZE DEVELOPMENT LATE THIS AFTERNOON. * THUNDERSTORMS LIKELY OVERNIGHT TONIGHT. KREIN //DISCUSSION...UPDATED 12Z... AT THE SURFACE...A LARGE AREA OF HIGH PRESSURE IS CENTERED OVER THE SOUTHERN TIP OF LAKE MICHIGAN KEEPING A VERY WEAK PRESSURE GRADIENT OVER THE REGION. A MID LEVEL IMPULSE CROSSING THE MIDDLE MISSISSIPPI VALLEY IS BRINGING AN AREA OF SHOWERS AND THUNDERSTORMS TO SERN IOWA AND INTO CENTRAL ILLINOIS. BASED ON THE LATEST RADAR TRENDS...EXPECT THAT ANY PCPN AND TS SHOULD REMAIN SOUTH OF OF THE TERMINALS THIS MORNING...THROUGH IT COULD CLIP THE SOUTHERN PORTIONS OF THE C90 TRACON AREA. AS THE CENTER OF THE HIGH SHIFT TO THE EAST TODAY...WINDS SHOULD BACK FROM SSWLY TO SELY THROUGH THE DAY. BY THIS AFTERNOON...WINDS ALOFT SHOULD BE LESS THAN 10KT WHILE SFC WINDS ALSO REMAIN LESS THAN 10KT...SO THERE IS A CHANCE FOR A LAKE BREEZE TO FORM. CONFIDENCE IS LOWER ON WHETHER THE LAKE BREEZE WILL PUSH FAR ENOUGH INLAND TO REACH ORD/MDW...AND WHETHER WINDS WILL BACK FURTHER FROM SELY TO ELY. AT THIS POINT...CONFIDENCE IS LOW ON THE LAKE BREEZE REACHING ORD/MDW WITH WINDS SYNOPTICALLY SETTING UP SELY THIS AFTERNOON. THE OTHER CONCERN FOR THE PERIOD WILL BE TIMING THE NEXT ROUND OF THUNDERSTORMS TO IMPACT THE REGION. WHILE THE ONGOING PCPN SHOULD REMAIN SOUTH OF THE TERMINALS...CONFIDENCE IS HIGHER THAT ANOTHER ROUND OF THUNDERSTORMS WILL DEVELOP TONIGHT OVER THE CNTRL PLAINS/IOWA AND THEN TRACK EASTWARD AS A STRONG LINE OF THUNDERSTORMS. LATEST GUIDANCE SUGGESTS THAT TS COULD REACH RFD ARND 06Z...AND THEN QUICKLY PUSHING TO THE EAST ACROSS THE CHICAGO AREA TERMINALS. WHILE CONFIDENCE IS RELATIVELY HIGH IN TS IMPACTING THE TERMINALS OVERNIGHT TONIGHT...TIMING AND DURATION IS A LITTLE LOWER AND THERE IS A CHANCE THAT TS COULD REACH THE TERMINALS A LITTLE EARLIER THAN CURRENTLY INDICATED IN THE TAFS. KREIN //ORD AND MDW CONFIDENCE...UPDATED 16Z... * MEDIUM TO HIGH CONFIDENCE IN GENERAL WIND TRENDS. * LOW TO MEDIUM CONFIDENCE IN LAKE BREEZE DETAILS AND WHETHER THE LAKE BREEZE WILL REACH ORD/MDW. * MEDIUM TO HIGH CONFIDENCE IN TS IMPACTING THE TERMINALS THIS EVENING AND TONIGHT...LOWER CONFIDENCE IN EXACT TIMING... DURATION AND IMPACTS. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. WX NIL. NELY WINDS. FRIDAY...VFR. WX NIL. NELY WINDS. SATURDAY...VFR. WX NIL. NELY WINDS BACKING NWLY LATE. SUNDAY...CHANCE TSRA. MVFR POSSIBLE. NWLY WINDS BACKING SWLY. MONDAY...CHANCE TSRA. MVFR POSSIBLE. SWLY WINDS VEERING NWLY TUESDAY...SLIGHT CHANCE TSRA. VRBL WINDS. KREIN && .MARINE... 410 AM CDT HIGH PRESSURE IS OVER THE REGION WITH LIGHT SOUTHWEST WINDS. WINDS REMAIN LIGHT AND BECOME EAST THURSDAY MORNING AS A LOW PRESSURE SYSTEM MOVES OVER THE SOUTHERN END OF THE LAKE. GUIDANCE DIFFERS ON HOW STRONG THE LOW WILL BE SO WIND SPEEDS COULD BE STRONGER OVER THE SOUTHERN END OF THE LAKE IF THE LOW IS STRONGER. THE LOW SHIFTS EAST AND ANOTHER LOW PASSES WELL SOUTH OF THE LAKE OVER THE OHIO RIVER LATE THIS WEEK. PERSISTENT NORTH TO NORTHEAST WINDS AT 20KT OR LESS ARE EXPECTED THROUGH SATURDAY NIGHT. HIGH PRESSURE SPREADS SOUTH OF THE LAKE WHILE A LOW SPREADS OVER THE LAKE SUNDAY NIGHT WITH WINDS BCMG SOUTH SUNDAY EVENING AND REMAINING SOUTH TO SOUTHWEST THROUGH MONDAY NIGHT. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022- ILZ023-ILZ032-ILZ033-ILZ039...7 PM WEDNESDAY TO 1 PM THURSDAY. IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019...7 PM WEDNESDAY TO 1 PM THURSDAY. LM...NONE. && $$ 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 NORTHERN INDIANA
406 PM EDT WED JUN 24 2015 .SYNOPSIS... ISSUED AT 400 PM EDT WED JUN 24 2015 A WARM FRONT WILL MOVE NORTH INTO THE REGION TONIGHT INTO THURSDAY...PROVIDING THE FOCUS FOR SHOWERS AND THUNDERSTORMS. LOCALLY HEAVY RAINFALL WILL BE THE MAIN THREAT...BUT A RISK OF DAMAGING WINDS DOES EXIST WITH THE STRONGEST STORMS. LOWS TONIGHT WILL BE IN THE LOWER TO MIDDLE 60S. CLOUDS AND EXPECTED RAINFALL WILL KEEP HIGHS IN THE MIDDLE 70S TO NEAR 80. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 400 PM EDT WED JUN 24 2015 AS USUAL WITH SUMMER CONVECTION...A VERY COMPLICATED SETUP WITH OVERNIGHT AND THURSDAY CONVECTION HIGHLY DEPENDENT ON WHAT HAPPENS UPSTREAM TONIGHT. SEVERE WEATHER AND LOCALLY HEAVY RAINFALL THE MAIN CONCERNS. SEVERAL CLUSTERS OF CONVECTION ONGOING THIS AFTERNOON. WEAKENING CONVECTION IN IL HAS STALLED NORTHWARD MOVEMENT OF WARM FRONTAL BOUNDARY BUT CONVECTION OVER IA BEING FUELED BY STRONG MOISTURE ADVECTION AND LOW LEVEL JET OVER SURGING BOUNDARY. EXPECT EARLY EVENING TO BE DRY IN OUR REGION BUT FIRST FOCUS WILL BE ON DECAYING COMPLEX FROM IA MOVING INTO OUR NORTHWEST LATER THIS EVENING. HRRR AND RAP NOW PICKING UP ON THIS WHILE LOWER RES SPECTRAL MODELS SEEM TO KEEP THIS SYSTEM TOGETHER AND MOVE ACROSS OUR NORTH. THINK THE HIGHER RES GUIDANCE HAVE A GOOD HANDLE ON THIS SYSTEM AS INSTABILITY REMAINS WEAK TO NON EXISTENT UNTIL LATER TONIGHT WHEN MUCAPES RISE TO BETWEEN 1000 AND 1500 J/KG. 0-3 KM AND DEEPER LAYER SHEAR ALSO INCREASE LATE WITH STRENGTHENING WEST TO SOUTHWEST LOW LEVEL JET FUELING SECONDARY MCS DEVELOPMENT UPSTREAM. THIS SYSTEM EXPECTED TO PROPAGATE INTO OUR WEST AND SOUTH CLOSER TO DAYBREAK. THIS WOULD BE THE SYSTEM TO BRING FIRST ROUND OF POTENTIAL SEVERE WEATHER IN FORM OF MAINLY DAMAGING WINDS AND HEAVY RAINFALL BUT AN ISOLATED TORNADO COULD OCCUR GIVEN MAGNITUDE OF SHEAR AND LOW LEVEL BOUNDARY WITH BACKED WINDS. THUS THE ENHANCED TO SLIGHT RISK OUTLOOK FOR THIS AREA. NEXT FOCUS WILL BE ON POSSIBILITY OF ANOTHER ROUND OF SEVERE WEATHER AND HEAVY RAIN THURSDAY AFTERNOON ALONG SFC BOUNDARY. THIS REMAINS HIGHLY CONDITIONAL ON WHAT HAPPENS OVERNIGHT AND HOW MUCH WE CAN DESTABILIZE THURSDAY AFTERNOON. SOUTHERN AREAS LOOK TO BE IN THE MOST FAVORABLE AREA AND HEAVY RAINFALL REMAINS POSSIBLE WITH PWAT VALUES IN THE 1.25 TO 1.50 INCH RANGE. ALL OF THESE FACTORS FOR HEAVY RAINFALL POTENTIAL WITH MULTIPLE SYSTEMS COUPLED WITH THE VERY SATURATED GROUND AND STILL NEARLY FULL RIVERS...STREAMS AND RESERVOIRS WARRANTED THE FLASH FLOOD WATCH IN THESE AREAS THAT CANNOT TAKE MUCH RAINFALL. && .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 400 PM EDT WED JUN 24 2015 THURSDAY NIGHT THROUGH WEDNESDAY... WESTERLY FLOW WILL BUCKLE AND THE EASTERN TROF WILL DEEPENG BEGINNING FRIDAY AND PERSISTING THROUGH THE REMAINDER OF THE EXTNENDED FORECAST. WITH THE HIGH AMPLITUDE RIDGE OVER THE WESTERN US...EXPECT TO SEE CONTINUED BELOW NORMAL TEMPERATURES...MOSTLY CLOUDY SKIES AND CONTINUED THREAT OF SHOWERS / THUNHDERSTORMS. BAROCLINIC DEEPENING FORECAST TO OCCUR OVER THE CENTRAL MISSISSIPPI RIVER VALLEY FRIDAY NIGHT EJECTS INTO THE OHIO RIVER VALLEY DURING THE DAY SATURDAY AND THIS WILL FAVOR RAINFALL OVER THE EASTERN HALF OF THE CWA. THIS WILL BE SLOW TO MOVE OUT AS YET ANOTHER IN A SERIES OF SHORT WAVES DIVES INTO THE REGION. THIS WILL DEEPEN THE TROF. ALL LONG RANGE MODELS SUGGEST SEVERAL SHORTWAVES TO DROP THROUGH THE GREAT LAKES REGION THROUGHOUT THE PERIOD...AND EACH HAS SLIGHT TIMING AND INTENSITY DIFFERENCES. WITH THE WARM WATER TEMPERATURES AND THE COLD FLOW OVER THE REGION...EXPECT A PROLONGED PERIOD OF CLOUDS AND -SHRA TO CONTINUE FROM SUN-WEDNESDAY. APPEARS THAT THE FRONTAL BOUNDARY WILL REMAIN SOUTH...OVER THE OHIO RIVER VALLEY AND THIS WILL HELP KEEP SIGNIFICANT AND HEAVIER RAINFALL TO OUR SOUTH. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 133 PM EDT WED JUN 24 2015 THUNDERSTORM CHANCES REMAIN PRIMARY CONCERN FOR AVIATION THIS PERIOD. MID AND HIGH CLOUDS TO THIN THIS AFTERNOON BUT SHOULD SEE VFR CONDITIONS THROUGH THE EVENING. A CONVECTIVE COMPLEX IS EXPECTED TO MOVE THROUGH IL LATE TONIGHT AND LIKELY WILL DIVE INTO NORTHERN INDIANA AFTER 06Z. SPREAD AMONG HIRES MODELS REMAINS HIGH ON TRACK AND LOCATION OF STRONGEST THUNDERSTORMS. LOOKS LIKE BOTH TAF SITES SHOULD AT LEAST SEE SOME SHOWERS WITH VICINITY THUNDER SO CONTINUED THAT TREND WITH THIS PACKAGE UNTIL MORE DETAIL CAN BE ADDED. IFR CIGS AND VIS POSSIBLE IF THIS SYSTEM TRACKS DIRECTLY OVER TAF SITES WITH STRONG WIND GUSTS AND HEAVY RAIN POTENTIAL AS WELL...MAINLY AFTER 06Z. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING FOR INZ003-012>015-020-022>027-032>034. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...FISHER SHORT TERM...LASHLEY LONG TERM...LEWIS AVIATION...LASHLEY 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 DES MOINES IA
650 PM CDT THU JUN 25 2015 .SHORT TERM /TONIGHT/... ISSUED AT 356 PM CDT THU JUN 25 2015 MAIN FORECAST CONCERN WAS FOCUSED ON WEAK SHORTWAVE CUTTING ACROSS NEBRASKA AND POTENTIALLY BRINGING SOME LOCALLY HEAVY RAIN TO FAR SOUTHERN IOWA TONIGHT. BOUNDARY LOOKS TO BE SET UP IN NORTHERN MISSOURI AND POSSIBLY SHIFT NORTH ENOUGH TO THE IOWA BORDER TONIGHT...BUT HAVE FAIRLY HIGH CONFIDENCE THAT IS THE FARTHEST EXTENT NORTH IT WILL REACH. DECENT MOISTURE CONVERGENCE ALONG THE MO/IA BORDER WITH STILL A GOOD ATMOSPHERE FOR EFFICIENT RAIN PRODUCERS. PRECIPITABLE WATER VALUES AROUND 1.5 INCHES AND WARM LAYER CLOUD DEPTHS IN THE 3500-3800 METER RANGE. FORWARD PROPAGATION CORFIDI VECTORS ORIENTED WEST TO EAST PROVIDING SOME TRAINING POTENTIAL ALONG THE FAR SOUTH. THE 25.19Z HRRR KEEPS MUCH OF THE HEAVY CONVECTION IN MISSOURI. HOWEVER...INCREASED POPS AND QPF OVER THE SOUTHERN TIER OF COUNTIES ALONG THE MISSOURI BORDER. OTHER CONCERN WAS ANOTHER WEAK SHORTWAVE TO PROVIDE SOME ELEVATED SHOWERS AND ISOLATED THUNDERSTORM OVER THE REMAINDER OF THE FORECAST AREA. QPF AMOUNTS SHOULD REMAIN UNDER QUARTER OF AN INCH AND THUS LOW IMPACT ON ANY ONGOING FLOODING .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 356 PM CDT THU JUN 25 2015 A MUCH...MUCH QUIETER 7 DAYS AHEAD IN THIS LONG TERM FCST PERIOD. WATER VAPOR IMAGERY PICKING UP ON HIGH PRESSURE COMING ONSHORE NEAR THE OREGON COASTLINE. THIS HIGH PRESSURE WILL HAVE SIGNIFICANT INFLUENCE ON OUR WEATHER MUCH OF NEXT WEEK. FRIDAY MORNING...MODELS PICKING UP ON A SHORTWAVE CONTINUING THROUGH SOUTHERN IA/NORTHERN MO. ISENTROPIC LIFT PERSISTING INTO 12Z AS THIS SYSTEM WILL LIKELY BE CLIPPING AT LEAST THE SOUTHERN TWO TO THREE TIERS OF COUNTIES IN IA. WITH YESTERDAY/S BOUNDARY LINGERING IN NORTHERN MO...A LOT OF THE MOISTURE FROM THURSDAY/S SYSTEM STILL AROUND. MODELS FOCUSING IN ON PWATS BTX 1.5 AND 1.75 INCHES...WHICH IS AROUND +1 TO +2 STD DEV. GOOD SUPPORT ALOFT AS MID-LEVEL Q-VECTOR CONV PRESENT TO INCREASE LIFT. 0-6KM MIXING RATIOS AROUND 7 G/KG WHICH IS DECENT ENOUGH. OVERALL SOUNDING PROFILE MUCH LESS SATURATED THAN MOST OF THIS WEEK...SO THIS SYSTEM WILL NOT BE THE MOST EFFICIENT IN RAIN PRODUCTION. FRI AFTERNOON TEMPS...850MB TEMPS AROUND 12C IN OUR EAST AND 14C IN OUR WEST...ABOUT -1 TO -2 STD DEV. THURSDAY/S 850 MB TEMPS WERE AROUND 14C NE TO 17C SW. AM EXPECTING SUNSHINE TO BREAK THROUGH...BUT NOT A LOT...SO HAVE KEPT TEMPS IN THE MID 70S. FRI AFTERNOON THUNDERSTORM POTENTIAL...0-6KM MUCAPE VALUES BTX 700 AND 1000 J/KG WHICH WHICH IS MINIMAL. 0-6KM BULK SHEAR NEAR 30KTS...ALSO MINIMAL. LCL HEIGHTS ABOVE 1000M. OVERALL SOUNDING PROFILE SUGGESTS ANYTHING THAT FORMS WOULD BE ELEVATED. THUS OVERALL...AM EXPECTING NIL SVR/TOR THREAT FRI PM AND THERE MAY BE A FEW SHORT LIVED NON-SEVERE STORMS PRIMARILY IN OUR NW. FOR SATURDAY NIGHT INTO SUNDAY EVENING...MODELS CONSISTENT WITH PROPAGATING AN AREA OF LOW PRESSURE FROM NW MINNESOTA INTO SE MINNESOTA. A WEAK COLD FRONT WILL BE ATTACHED TO THIS AND PUSHING THROUGH IA DURING THE DAYTIME. THE 12Z GFS IS A FAST OUTLIER WITH THIS SYSTEM AS IT PLACES THE BOUNDARY EAST OF OUR CWA BY 12-15Z SUN. HAVE MAINLY DISREGARDED THE GFS AND WENT WITH AN AVERAGE OF OTHER MODELS. PWATS JUMP FROM AROUND 1.25 TO 1.5 INCHES AND 0-6KM MUCAPE VALUES ARE AROUND 400 TO 600 J/KG. POSITION OF FRONT DURING PEAK DAYTIME HEATING IMPORTANT FOR SVR POTENTIAL. AS OF NOW...ALL SIGNS POINT TO THIS BOUNDARY BEING WELL EAST OF THE CWA BY DAYTIME HEATING. FOR MONDAY AND THE REST OF THIS LONG TERM FCST PERIOD...PERSISTENCE BECOMES A GOOD FORECAST THROUGH MID-WEEK. AN UPPER LEVEL TROUGH OVER THE NORTHEASTERN US AND AN UPPER LEVEL RIDGE OVER THE MOUNTAIN WEST WILL KEEP THE DMX CWA IN NORTHWESTERLY FLOW SEEMING INTO THE NEXT THU/FRI/SAT TIMEFRAME. A HUGE THERMAL RIDGE WILL BUILD OVER THE MOUNTAIN WEST COINCIDENT WITH THE UPPER LEVEL HIGH. THE RIDGE WILL STAY TO OUR WEST AND 850 MB TEMPS WILL BE IN THE DMX CWA WILL BE AROUND 15C TO OUR EAST AND 18C TO THE WEST. MODELS HINTING AT THERMAL RIDGE CRASHING DOWN INTO IA SOMETIME LATER IN THE WEEK...BRINGING A RETURN TO POP CHANCES TO THE AREA. && .AVIATION...26/00Z ISSUED AT 650 PM CDT THU JUN 25 2015 THERE WILL BE A BRIEF BREAK IN THE MVFR CIGS BUT AN UPPER LEVEL WAVE WILL PUSH INTO IA LATE EVENING AND OVERNIGHT THROUGH FRIDAY MORNING LOWERING CIGS ONCE AGAIN AND BRINGING SOME SCT SHRA/TSRA TO MOST TAF LOCATIONS. SFC FLOW WILL REMAIN GENERALLY AOB 10KTS OUT OF A N TO NE DIRECTION. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...KOTENBERG AVIATION...FAB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
342 PM CDT WED JUN 24 2015 .SHORT TERM /TONIGHT/... ISSUED AT 341 PM CDT WED JUN 24 2015 COMPLEX SCENARIO SETTING UP ACROSS IOWA TONIGHT WITH A WARM FRONT SURGING NORTH-NORTHEAST INTO SOUTHWEST IOWA PROVIDING SOME DESTABILIZATION OVER SOUTHWEST IOWA. MUCH OF THIS AREA REMAINS CAPPED AT THE MOMENT...BUT WITH IMPRESSIVE EFFECTIVE SHEAR AND HIGH CAPE VALUES AVAILABLE...IF STORMS DEVELOP IN THIS LOCATION THEY LIKELY WILL RAPIDLY BECOME SEVERE THIS AFTERNOON AND EVENING. SUPERCELLS ARE CERTAINLY POSSIBLE ON INITIATION WITH STRONG VEERING AND DEEP LAYER SHEAR WILL PROVIDE A TORNADIC THREAT THROUGH THE MID- EVENING HOURS. HOWEVER...THINKING THIS AREA SHOULD REMAIN CAPPED UNTIL LLJ DEVELOPS TONIGHT COMBINED WITH THE TIMING OF A STRONG SHORTWAVE OVER THE HIGH PLAINS PUSH ACROSS THE STATE. EXPECTING THE WARM FRONT TO SURGE NORTH BETWEEN THE INTERSTATE 80 TO HIGHWAY 20 CORRIDOR. STORM REDEVELOPMENT THIS EVENING LOOKS TO BETWEEN 02Z TO 05Z THURSDAY OVER THIS CORRIDOR FROM WEST TO EAST AND THE FRONT SHOULD LIGHT UP ALONG THIS REGION. THE 24.19Z HRRR HAS A DECENT HANDLE ON CURRENT RADAR TRENDS...ALTHOUGH DIMINISHES THE CURRENT CONVECTION OVER CRAWFORD/CARROLL COUNTIES THIS AFTERNOON. POTENTIAL FOR STORMS TO LINGER A LITTLE LONGER THAN WHAT THE HRRR SUGGESTS BUT STILL LOOKING AT A BREAK BETWEEN REDEVELOPMENT LATER THIS EVENING. SEVERE POTENTIAL STILL EXISTS DURING THE OVERNIGHT BUT LOOKING MORE LIKELY STRAIGHT LINE WIND EVENT POTENTIAL. .LONG TERM /THURSDAY THROUGH WEDNESDAY/... ISSUED AT 341 PM CDT WED JUN 24 2015 MAIN SHORT WAVE TO TRACK SOUTHEAST OF AREA BY 12Z...BUT RESIDUAL CONVECTION MAY LINGER OVER THE SOUTHEAST THROUGH MORNING. AS FRONT SAGS SOUTH THURSDAY...EXPECTING A BREAK FROM THE CONVECTION THROUGH LATE AFTERNOON. ANOTHER UPPER LEVEL SHORTWAVE WILL DROP SOUTHEAST ACROSS THE AREA THURSDAY NIGHT AND INTO FRIDAY WITH ENOUGH LIFT AND INSTABILITY TO PRODUCE SCT THUNDERSTORMS THROUGH THE DAY. WITH CLOUDS ACROSS THE REGION EXPECT THAT HIGHS WILL BE HELD BACK IN THE 70S FOR ALL OF THE AREA. THE TROUGH FINALLY PULLS SOUTHEAST OF THE REGION FRIDAY NIGHT WITH A PERIOD OF QUIET WEATHER FROM FRIDAY NIGHT THROUGH SATURDAY EVENING. OVER THE NEXT FEW DAYS THE PATTERN WILL SHIFT TO A NORTHWESTERLY FLOW ALOFT. THIS WILL LESSEN THE CHANCES FOR HEAVY RAINFALL AND ALSO BRING TEMPERATURES TO NEAR NORMAL OR SLIGHTLY BELOW NORMAL. ANOTHER NORTHERN STREAM SHORTWAVE AND COOL FRONT WILL DROP SOUTH SATURDAY EVENING WITH ADDITIONAL SCATTERED THUNDERSTORMS SUNDAY. HIGHS SATURDAY AND SUNDAY WILL BE SOMEWHAT COOLER WITH NORTHWEST FLOW. HIGHS WILL REMAIN IN THE UPPER 70S TO LOWER 80S. WITH THE NORTHWEST FLOW IN PLACE THROUGH MIDWEEK NEXT WEEK...EXPECT MORE OF THE SAME. THE RIDGE SHOULD REMAIN WEST OF IOWA WITH SOME CHANCES FOR SHOWERS OR THUNDERSTORMS AS COOL FRONTS DROP SOUTH INTO THE PLAINS AND GREAT LAKES. TEMPERATURES WILL CHANGE LITTLE WITH HIGHS IN THE 70S TO LOWER 80S AND LOWS IN THE 50S TO 60S. && .AVIATION...24/18Z ISSUED AT 115 PM CDT WED JUN 24 2015 STORM ACTIVITY WILL CONTINUE ACROSS CENTRAL TO NORTH-CENTRAL IOWA THIS AFTERNOON INTO THE EVENING. CERTAINLY MVFR FOR CIGS AND VIS ARE POSSIBLE AND EVEN TO IFR/LIFR CONDITIONS WITH THE HEAVY TS...BUT LOW CONFIDENCE WITH MENTIONING IFR/LIFR CONDITIONS AS DIFFICULT TO TIME AND LOCATE OF STORMS LATER THIS AFTERNOON. ONCE THIS FIRST ROUND OF STORMS MOVES EAST BY 22Z...ANOTHER ROUND LOOKS TO DEVELOP ALONG THE WARM FRONT LATER THIS EVENING. HAVE MVFR VIS OR CIGS FOR RAIN MENTIONED BY 03Z. && .HYDROLOGY... ISSUED AT 341 PM CDT WED JUN 24 2015 WILL STILL NEED TO CONSIDER FLASH FLOODING OVERNIGHT AND HAVE EXPANDED THE WATCH FARTHER WEST. VERY GOOD MOISTURE TRANSPORT... WARM LAYER CLOUD DEPTHS IN THE 13-14KFT RANGE AND PRECIPITABLE WATER VALUES WELL OVER 2 INCHES TONIGHT. FAIRLY HIGH CONFIDENCE IN WIDESPREAD FLASH FLOODING OVER THE INTERSTATE 80 TO HIGHWAY 20 CORRIDOR. RAINFALL RATES OF 2 TO 4 INCHES PER HOUR ARE LIKELY AND WITH THE RAIN THAT FELL ALREADY TODAY...IT WILL NOT TAKE MUCH TO CAUSE SOME FLASH FLOODING AND POTENTIAL SIGNIFICANT FLASH FLOODING ISSUES OVER THE AFOREMENTIONED CORRIDOR. THUS...EXPANDED THE FLASH FLOOD WATCH FURTHER WEST AND INCREASED POPS AND QPF CONSIDERABLY B/T 03-09Z THURSDAY. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR ADAIR-APPANOOSE- AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CLARKE- CRAWFORD-DALLAS-DAVIS-FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON- HARDIN-HUMBOLDT-JASPER-LUCAS-MADISON-MAHASKA-MARION-MARSHALL- MONROE-POLK-POWESHIEK-SAC-STORY-TAMA-WAPELLO-WARREN-WEBSTER- WRIGHT. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...PODRAZIK HYDROLOGY...PODRAZIK
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
322 PM CDT WED JUN 24 2015 .SYNOPSIS... ISSUED AT 305 PM CDT WED JUN 24 2015 12Z UA ANALYSYS HAS AN 850MB WARM FRONT FROM CENTRAL NEBRASKA...THROUGH SOUTHWEST IOWA...AND INTO SOUTHERN ILLINOIS. ALONG AND SOUTH OF THIS FRONT WAS VERY WARM AND MOIST AIR. A WEAK LLJ RAN FROM WEST TEXAS INTO CENTRAL KANSAS. SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON HAS A LOOSELY ORGANIZED CONVECTIVE COMPLEX MOVING ACROSS IOWA WITH ANOTHER DEVELOPING BACK ALONG THE MISSOURI RIVER. 18Z SFC DATA PLACES AN INFERRED LOW JUST EAST OF KOMA WITH A WARM FRONT RUNNING FROM THE LOW TO NEAR KSTL. DEW POINTS ALONG AND SOUTH OF THE WARM FRONT WERE IN THE UPPER 60S TO LOWER 70S. NORTH OF THE WARM FRONT DEW POINTS WERE IN THE 50S TO LOWER 60S. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 305 PM CDT WED JUN 24 2015 RADAR AND RAP TRENDS WILL TAKE THE CURRENT CONVECTIVE COMPLEX EAST LATE THIS AFTERNOON AND INTO THE EARLY EVENING. THE LACK OF INSTABILITY ACROSS THE AREA MEANS THE COMPLEX WILL BE RAIN WITH EMBEDDED THUNDERSTORMS. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WITH THE STRONGER CONVECTION. THERE ARE STILL QUESTIONS REGARDING THE OVERALL SEVERE THREAT FOR LATE THIS AFTERNOON AND EVENING. THE SECONDARY CONVECTIVE COMPLEX BACK ALONG THE MISSOURI RIVER IN WESTERN IOWA MAY POSE THE BETTER THREAT OF SEVERE STORMS. IF SEVERE STORMS DO OCCUR LATE THIS AFTERNOON AND EVENING...AREAS SOUTH OF I-80 WOULD BE MORE AT THREAT. AFTER SUNSET AND THROUGH SUNRISE THURSDAY...THE SECONDARY CONVECTIVE COMPLEX WILL GROW UPSCALE AS FORCING AND MOISTURE INCREASES ACROSS THE AREA. THE MODELS DO SUGGEST A SURFACE LOW MOVING THROUGH THE CENTRAL PART OF THE AREA TONIGHT HELPING TO ENHANCE THE RAINFALL. HEAVY RAIN IS DEFINITELY A THREAT AS STORMS MAY MOVE REPEATEDLY OVER THE SAME AREAS. BASED ON WHAT HAS ALREADY OCCURRED TODAY...RAINFALL OF 2 TO 4 INCHES IS PLAUSIBLE SHORTLY AFTER SUNRISE THURSDAY. ON THURSDAY...RAIN WILL SLOWLY END FROM NORTHWEST TO SOUTHEAST DURING THE DAY. IF CLOUDS REMAIN ACROSS THE AREA FOR MUCH OF THE DAY...THE NORTH HALF OF THE AREA MAY BE DRY DURING THE AFTERNOON HOURS. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 305 PM CDT WED JUN 24 2015 FORECAST HIGHLIGHTS OF THE LONG TERM PERIOD INCLUDE A TRANSITION TO NORTHWEST FLOW...COOLER TEMPERATURES...AND PERIODIC RAIN CHANCES. FOR THURSDAY NIGHT...THE FAR SOUTHERN FRINGE REMAINS IN THE MARGINAL RISK AREA FOR SEVERE STORMS ALONG THE RESIDUAL BOUNDARY. WILL ALSO HAVE TO MONITOR THIS AREA FOR HEAVY RAIN PER THE 12Z NAM...ALTHOUGH THAT PARTICULAR MODEL IS THE MOST BULLISH ON QPF. ON FRIDAY...EXPECT ADDITIONAL SCATTERED SHOWERS AND STORMS AS AN UPPER TROUGH DIPS THROUGH THE REGION IN SHARPENING NORTHWEST FLOW. THIS FORCING WILL EXIT QUICKLY FRIDAY NIGHT FOR A DRY PERIOD CONTINUING THROUGH SATURDAY. LOOKING AHEAD...ADDITIONAL SCATTERED RAIN WILL BE POSSIBLE EVERY DAY FROM SUNDAY THROUGH WEDNESDAY. PERSISTENT NORTHWEST FLOW WILL GUIDE PERIODIC SHORT WAVE ENERGY INTO THE FORECAST AREA. CONSENSUS BLENDED POPS OF 20-40 PERCENT ARE REASONABLE. THE OVERALL SEVERE WEATHER THREAT THROUGH THIS PERIOD IS LOW. SLIGHTLY BELOW NORMAL TEMPERATURES ARE EXPECTED THROUGH THE BULK OF THE LONG TERM PERIOD...WITH HIGHS MAINLY IN THE UPPER 70S...PERHAPS OCCASIONALLY TOUCHING THE LOWER 80S.&& .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1233 PM CDT WED JUN 24 2015 CONVECTION ACROSS IOWA AND CENTRAL ILLINOIS WILL SLOWLY INCREASE IN COVERAGE THROUGH 00Z/25 AND THEN EVOLVE INTO AN ORGANIZED THUNDERSTORM COMPLEX AFT 00Z/25. VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH 00Z/25 WITH SPOTTY MVFR/IFR CONDITIONS IN SHRA/TSRA. AFT 00Z/25 CONDITIONS WILL SLOWLY DETERIORATE TO MVFR AS THE THUNDERSTORM COMPLEX DEVELOPS. PERIODS OF IFR CONDITIONS ARE POSSIBLE IF A STRONGER STORM AFFECTS A TAF SITE. && .HYDROLOGY... ISSUED AT 305 PM CDT WED JUN 24 2015 ANOTHER ROUND OF HEAVY RAIN WILL BE SEEN ACROSS THE AREA FROM LATE THIS AFTERNOON INTO THURSDAY MORNING. SOILS ACROSS THE AREA ARE ALREADY QUITE MOIST AND THIS ADDITIONAL RAINFALL WILL QUICKLY SATURATE THE SOILS. AREA RIVERS ARE ALREADY RUNNING HIGH FROM HEAVY RAINFALL OVER THE PAST 10 DAYS AND SOME ARE IN FLOOD. THIS ADDITIONAL RAIN WILL RESULT IN ADDITIONAL RISES...SOME POSSIBLY SIGNIFICANT...ON AREA RIVERS AND INCREASE THE FLOOD THREAT. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR BENTON-BUCHANAN- CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA- JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA- MUSCATINE-SCOTT-VAN BUREN-WASHINGTON. IL...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR BUREAU-CARROLL- HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER- PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE. MO...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR CLARK-SCOTLAND. && $$ SYNOPSIS...08 SHORT TERM...08 LONG TERM...RP KINNEY AVIATION...08 HYDROLOGY...08
AREA FORECAST DISCUSSION
NWS GOODLAND KS
225 PM MDT WED JUN 24 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 206 PM MDT WED JUN 24 2015 MAIN PROBLEM IS WHERE THE FRONT CURRENTLY WAFFLING BACK AND FORTH OVER OUR AREA IS GOING TO GO AND HOW FAST. INITIALLY THE FRONT CAME FURTHER SOUTH FASTER THAN ANYTHING DEPICTED. THE LAST FEW HOURS IT HAS STALLED NEAR A BURLINGTON TO GOODLAND TO OBERLIN TO NORTON LINE. BOUNDARY IS FORECAST TO SLOWLY SAG SOUTH THROUGH TOMORROW. MODELS...ESPECIALLY THE LARGE SCALE OUTPUT...NOT DOING WELL WITH THE FRONT POSITION. THE RAP IS THE CLOSEST TO REALITY RIGHT NOW. FOR TONIGHT...700 MB TEMPERATURES ARE LESS BUT STILL NEAR PLUS 15. SOME WEAK SHORTWAVE ENERGY IS OVER THE SOUTHEAST PORTION NEAREST THE FRONT WITH ANOTHER SHORTWAVE TROUGH MOVING IN FROM THE WEST DURING THE EVENING. SO GOING BY ABOVE REASONING WHICH MATCHES WHAT THE RAP IS SHOWING...ISOLATED CONVECTION DEVELOPS ALONG AND JUST TO THE EAST OF THE FRONTAL BOUNDARY. THIS CONVECTION GOES THROUGH ROUGHLY MID EVENING. BELIEVE THAT THUNDERSTORMS WILL MOVE IN FROM THE WEST MUCH LIKE LAST NIGHT. MODELS DO NOT SHOW THEM MAKING IT VERY FAR INTO THE FORECAST AREA. THINK THAT THEY WILL MAKE FURTHER THAN INDICATED AND THIS WILL NEED TO BE WATCHED. WENT AHEAD AND HAVE SLIGHT CHANCE TO LOW CHANCE POPS FOR TONIGHT. FOR THURSDAY...MODELS VERY SLOW IN MOVING THE FRONT SOUTH. NOT SURE HOW FAR SOUTH IT WILL GO/WHERE IT WILL BE SINCE THE MODEL OUTPUT IS SO POOR RIGHT NOW. NAM STILL DOES NOT HAVE IT THROUGH THE AREA BY LATE TOMORROW. OTHER OUTPUT HAS IT JUST SOUTH OF THE AREA. DO HAVE HAVE LOW LEVEL UPSLOPE BUT NOT A LOT OF FORCING IN THE MID AND UPPER LEVELS. SINCE AM NOT SURE OF THE FINAL FRONTAL POSITION AND THE POSSIBILITY OF A WEAK SHORTWAVE AFFECTING THE AREA JUST HAVE SLIGHT POPS IN THE AFTERNOON AT THIS TIME. TEMPERATURES WILL BE COOLER BUT HOW MUCH WILL BE DETERMINED BY FRONTAL POSITION. WENT NEAR TO SLIGHTLY BELOW GUIDANCE AT THIS TIME. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 225 PM MDT WED JUN 24 2015 THURSDAY NIGHT...MODELS CONTINUE TO SHOW POTENTIAL FOR THUNDERSTORM INITIATION ALONG FRONTAL ZONE ACROSS THE SOUTHERN PART OF OUR CWA. WITH LIMITING FORCING ALOFT I AM NOT SURE WHAT COVERAGE WILL INITIALLY LOOK LIKE EARLY IN THE EVENING. INCREASING MOISTURE FLUX/MODERATE INSTABILITY...AND PEAK HEIGHT FALLS/FORCING WILL OCCUR LATER IN THE EVENING WITH SHORTWAVE TROUGH ROTATING INTO THE REGION FROM THE NORTHERN PLAINS. THUNDERSTORM COMPLEX MAY DEVELOP OVER NORTH CENTRAL NEBRASKA AND MOVE SOUTH INTO OUR CWA. TRACK WILL BE DEPENDENT ON MAIN INSTABILITY AXIS/FRONT POSITION...HOWEVER THIS SHOULD GENERALLY REMAIN ACROSS THE NORTH/NORTHEAST HALF OF THE CWA. CONSIDERING THE VERY MOIST AIR MASS IN PLACE I COULD SEE LOCALLY HEAVY RAINFALL...THOUGH SLOWEST STORMS WOULD BE ALONG FRONTAL ZONE EARLY IN THE EVENING AS GUIDANCE SEEMS TO FAVOR A MORE PROGRESSIVE FLOW LATER IN THE EVENING WHEN BETTER COVERAGE IS EXPECTED. MODERATE INSTABILITY A GOOD EFFECTIVE SHEER WILL ALSO SUPPORT DAMAGING WIND/SEVERE HAIL THREAT...PARTICULARLY WITH THUNDERSTORM COMPLEX LATER IN THE EVENING. FRIDAY-FRIDAY NIGHT...H5 RIDGE WILL BEGIN TO AMPLIFY WITH TROUGH DEEPENING AS IT SLIDES EAST. MOISTURE ADVECTION/ LINGERING INSTABILITY MAY ALLOW FOR FURTHER THUNDERSTORM DEVELOPMENT ALONG FRONTAL ZONE LINGERING THROUGH FRIDAY NIGHT. LARGE SCALE FORCING WILL BE LIMITED TO THE NORTHEAST...AND WITH SUBSIDENCE LIKELY SPREADING INTO THE REGION FROM THE NORTHWEST FRIDAY AFTERNOON-FRIDAY NIGHT. I KEPT POPS LIMITED TO 20...SINCE I AM NOT VERY CONFIDENT IN MEASURABLE PRECIP DURING THESE PERIODS. SATURDAY-WEDNESDAY...H5 RIDGE CONTINUES TO AMPLIFY OVER THE WESTERN US WITH OMEGA BLOCK PATTERN EVENTUALLY ESTABLISHING ITSELF THROUGH THE REMAINING EXTENDED PERIOD. THIS KEEPS AMPLIFIED NW FLOW IN PLACE ACROSS THE PLAINS WITH PRIMARY STORM TRACK WELL OUTSIDE OF CWA. MODELS SHOW LEE TROUGH ATTEMPTING TO REESTABLISH ITSELF WITH SHORTWAVES ALONG THE MISSISSIPPI RIVER VALLEY OCCASIONAL KICKING BACKDOOR FRONTS TOWARDS THE WESTERN PLAINS. TREND WILL BE TOWARDS PRIMARILY DRY CONDITIONS AND NEAR SEASONAL HIGHS MOST PERIODS. GUIDANCE IS SHOWING A LITTLE BIT BETTER PRECIP SIGNAL FROM THE ECMWF WITH SHORTWAVE PASSAGE OVER OUR CWA TUESDAY AFTERNOON-TUESDAY NIGHT...AS GFS/GEFS SHOWS LOWERING HEIGHTS ALOFT WITH RIDGE FLATTENING SLIGHTLY. THERE ISN`T A LOT OF CONSISTENCY BETWEEN MODELS...SO I LIMITED POPS TO 20/30. TUESDAY IS ALSO THE DAY WITH THE LARGEST TEMP SPREAD ALOFT/AT THE SURFACE WITH GFS POSSIBLY SUPPORTING NEAR 100F AND ECMWF CLOSER TO THE LOW/MID 90S. I KEPT MID- UPPER 90S INHERITED FROM WEIGHTED BLEND CONSIDERING THE RANGE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1133 AM MDT WED JUN 24 2015 VERY LOW CONFIDENCE AND UNCERTAIN FORECAST DUE TO POOR MODEL PERFORMANCE IN THE HANDLING THE FRONT CURRENTLY OVER OUR AREA. RAP MODEL IS THE CLOSEST BUT IT STILL IS NOT FAR ENOUGH SOUTH. USED THE RAP FOR THE WIND FORECAST THEN BLENDED IN THE OTHER MODEL OUTPUT THAT FITS IN WITH THE RAP SCENARIO. AT THIS TIME THINK ANY THUNDERSTORMS WILL DEVELOP TO THE EAST AND SOUTH OF BOTH SITES. FOR MOST OF THE PERIOD EXPECT VFR CONDITIONS. HOWEVER MVFR CONDITIONS WILL BE POSSIBLE AFTER 06Z...ESPECIALLY WITH THE CEILINGS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...DR AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
220 PM MDT WED JUN 24 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 206 PM MDT WED JUN 24 2015 MAIN PROBLEM IS WHERE THE FRONT CURRENTLY WAFFLING BACK AND FORTH OVER OUR AREA IS GOING TO GO AND HOW FAST. INITIALLY THE FRONT CAME FURTHER SOUTH FASTER THAN ANYTHING DEPICTED. THE LAST FEW HOURS IT HAS STALLED NEAR A BURLINGTON TO GOODLAND TO OBERLIN TO NORTON LINE. BOUNDARY IS FORECAST TO SLOWLY SAG SOUTH THROUGH TOMORROW. MODELS...ESPECIALLY THE LARGE SCALE OUTPUT...NOT DOING WELL WITH THE FRONT POSITION. THE RAP IS THE CLOSEST TO REALITY RIGHT NOW. FOR TONIGHT...700 MB TEMPERATURES ARE LESS BUT STILL NEAR PLUS 15. SOME WEAK SHORTWAVE ENERGY IS OVER THE SOUTHEAST PORTION NEAREST THE FRONT WITH ANOTHER SHORTWAVE TROUGH MOVING IN FROM THE WEST DURING THE EVENING. SO GOING BY ABOVE REASONING WHICH MATCHES WHAT THE RAP IS SHOWING...ISOLATED CONVECTION DEVELOPS ALONG AND JUST TO THE EAST OF THE FRONTAL BOUNDARY. THIS CONVECTION GOES THROUGH ROUGHLY MID EVENING. BELIEVE THAT THUNDERSTORMS WILL MOVE IN FROM THE WEST MUCH LIKE LAST NIGHT. MODELS DO NOT SHOW THEM MAKING IT VERY FAR INTO THE FORECAST AREA. THINK THAT THEY WILL MAKE FURTHER THAN INDICATED AND THIS WILL NEED TO BE WATCHED. WENT AHEAD AND HAVE SLIGHT CHANCE TO LOW CHANCE POPS FOR TONIGHT. FOR THURSDAY...MODELS VERY SLOW IN MOVING THE FRONT SOUTH. NOT SURE HOW FAR SOUTH IT WILL GO/WHERE IT WILL BE SINCE THE MODEL OUTPUT IS SO POOR RIGHT NOW. NAM STILL DOES NOT HAVE IT THROUGH THE AREA BY LATE TOMORROW. OTHER OUTPUT HAS IT JUST SOUTH OF THE AREA. DO HAVE HAVE LOW LEVEL UPSLOPE BUT NOT A LOT OF FORCING IN THE MID AND UPPER LEVELS. SINCE AM NOT SURE OF THE FINAL FRONTAL POSITION AND THE POSSIBILITY OF A WEAK SHORTWAVE AFFECTING THE AREA JUST HAVE SLIGHT POPS IN THE AFTERNOON AT THIS TIME. TEMPERATURES WILL BE COOLER BUT HOW MUCH WILL BE DETERMINED BY FRONTAL POSITION. WENT NEAR TO SLIGHTLY BELOW GUIDANCE AT THIS TIME. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 302 AM MDT WED JUN 24 2015 AT THE BEGINNING OF THE EXTENDED PERIOD MODELS ARE SHOWING THE LONGWAVE PATTERN AMPLIFYING THROUGH THE END OF THE PERIOD. A STRONG UPPER RIDGE IS LOCATED TO OUR WEST ALONG THE ROCKIES AND EXTENDING WELL INTO WESTERN CANADA. AT THE SAME TIME A DEEPENING TROUGH IS LOCATED OVER THE GREAT LAKES REGION AND EXTENDING IN THE SOUTHEASTERN U.S. THIS PATTERN SETS UP A PREDOMINANTLY NORTHWESTERLY UPPER FLOW OVER THE TRI STATE AREA. ON THE SURFACE THE LOCATED AREA WILL BE UNDER THE INFLUENCE OF A HIGH PRESSURE CENTER TO THE WEST OF THE CWA. THERE IS A SLIGHT CHANCES OF PRECIPITATION... MOSTLY IN THE FORM OF ISOLATED AFTERNOON AND EVENING CONVECTION... ASSOCIATED WITH THE OCCASIONAL SHORTWAVE TROUGHS THAT WILL MOVE THROUGH THE AREA FROM THE NORTH. OTHERWISE... EXPECT A MOSTLY DRY PERIOD WITH TEMPERATURES CLOSER TO NORMAL DUE TO THE NORTHERLY FLOW ALOFT AND A PERSISTENT EASTERLY SURFACE WINDS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1133 AM MDT WED JUN 24 2015 VERY LOW CONFIDENCE AND UNCERTAIN FORECAST DUE TO POOR MODEL PERFORMANCE IN THE HANDLING THE FRONT CURRENTLY OVER OUR AREA. RAP MODEL IS THE CLOSEST BUT IT STILL IS NOT FAR ENOUGH SOUTH. USED THE RAP FOR THE WIND FORECAST THEN BLENDED IN THE OTHER MODEL OUTPUT THAT FITS IN WITH THE RAP SCENARIO. AT THIS TIME THINK ANY THUNDERSTORMS WILL DEVELOP TO THE EAST AND SOUTH OF BOTH SITES. FOR MOST OF THE PERIOD EXPECT VFR CONDITIONS. HOWEVER MVFR CONDITIONS WILL BE POSSIBLE AFTER 06Z...ESPECIALLY WITH THE CEILINGS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...BW AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1138 AM MDT WED JUN 24 2015 .UPDATE... ISSUED AT 1027 AM MDT WED JUN 24 2015 COLD FRONT HAS COME MUCH FURTHER SOUTH THAN EXPECTED. COMBINATION OF COLD OUTFLOW FROM STORMS UP NORTH AND SURFACE LOWS OVER EASTERN COLORADO DEVELOPING DIFFERENTLY THAN WHAT THE MODELS WERE ANTICIPATING. NOTHING IS REALLY CATCHING THIS RIGHT NOW WITH THE RAP THE CLOSEST. HOWEVER...IT STILL IS NOT FAR ENOUGH SOUTH. ALSO SOME WEAK THUNDERSTORM DEVELOPMENT HAS OCCURRED ALONG THE FRONT. SO HAD TO UPDATE THE FORECAST FOR THE WINDS...COOLER TEMPERATURES IN THE NORTHERN PORTION OF THE AREA...MORE CLOUD COVER...AND A WIDER AREA AND SOONER INITIATION OF ISOLATED THUNDERSTORMS THROUGH THIS EVENING. WILL PROBABLY NOT BE THE LAST UPDATE. && .SHORT TERM...(TODAY THROUGH FRIDAY NIGHT) ISSUED AT 344 AM MDT WED JUN 24 2015 FORECAST FOCUS IS ON THE POSSIBILITY OF SEVERE THUNDERSTORMS ACROSS THE FORECAST AREA LATE THURSDAY INTO THURSDAY NIGHT. THE UPPER LEVEL ZONAL FLOW PATTERN ACROSS THE UNITED STATES TRANSITIONS TO A MORE MERIDIONAL PATTERN THURSDAY AND THURSDAY NIGHT. A RIDGE BUILDS OVER THE INTERMOUNTAIN WEST WHILE A TROUGH DEEPENS IN THE LEE OF THE ROCKIES AND OVER THE PLAINS STATES WITH THE PATTERN BECOMING MORE HIGHLY AMPLIFIED ON FRIDAY AND FRIDAY NIGHT. THE INITIAL SHORT WAVE TROUGH MOVING THROUGH THE WESTERLY FLOW ALOFT ACROSS THE NORTHERN PLAINS TODAY LIFTS A LOW CENTER OUT OF THE LOW PRESSURE AREA IN PLACE OVER THE FORECAST AREA. A PORTION OF THE SURFACE LOW REMAINS ANCHORED OVER THE CENTRAL HIGH PLAINS AND MOVES FURTHER SOUTH OVER THE PANHANDLE REGION THURSDAY AND THURSDAY NIGHT ALONG WITH THE FRONTAL BOUNDARY AS HIGH PRESSURE MOVES INTO THE NORTHERN SECTIONS OF THE CENTRAL HIGH PLAINS. THIS WILL BRING SOMEWHAT COOLER TEMPERATURES TO MAINLY THE NORTHERN SECTIONS OF THE REGION ON THURSDAY. IT WILL ALSO BRING A BETTER CHANCE OF THUNDERSTORMS TO THE REGION LATE THURSDAY INTO THURSDAY NIGHT. THE MARGINAL TO SLIGHT RISK OF SEVERE THUNDERSTORMS ALSO TRANSITIONS SOUTHWARD FROM THE NORTHERN PLAINS TODAY TO THE CENTRAL PLAINS ON THURSDAY AND THE SOUTHERN PLAIN ON FRIDAY. COOLER MORE SEASONABLE TEMPERATURES WILL REMAIN IN PLACE THROUGH FRIDAY AND FRIDAY NIGHT. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 302 AM MDT WED JUN 24 2015 AT THE BEGINNING OF THE EXTENDED PERIOD MODELS ARE SHOWING THE LONGWAVE PATTERN AMPLIFYING THROUGH THE END OF THE PERIOD. A STRONG UPPER RIDGE IS LOCATED TO OUR WEST ALONG THE ROCKIES AND EXTENDING WELL INTO WESTERN CANADA. AT THE SAME TIME A DEEPENING TROUGH IS LOCATED OVER THE GREAT LAKES REGION AND EXTENDING IN THE SOUTHEASTERN U.S. THIS PATTERN SETS UP A PREDOMINANTLY NORTHWESTERLY UPPER FLOW OVER THE TRI STATE AREA. ON THE SURFACE THE LOCATED AREA WILL BE UNDER THE INFLUENCE OF A HIGH PRESSURE CENTER TO THE WEST OF THE CWA. THERE IS A SLIGHT CHANCES OF PRECIPITATION... MOSTLY IN THE FORM OF ISOLATED AFTERNOON AND EVENING CONVECTION... ASSOCIATED WITH THE OCCASIONAL SHORTWAVE TROUGHS THAT WILL MOVE THROUGH THE AREA FROM THE NORTH. OTHERWISE... EXPECT A MOSTLY DRY PERIOD WITH TEMPERATURES CLOSER TO NORMAL DUE TO THE NORTHERLY FLOW ALOFT AND A PERSISTENT EASTERLY SURFACE WINDS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1133 AM MDT WED JUN 24 2015 VERY LOW CONFIDENCE AND UNCERTAIN FORECAST DUE TO POOR MODEL PERFORMANCE IN THE HANDLING THE FRONT CURRENTLY OVER OUR AREA. RAP MODEL IS THE CLOSEST BUT IT STILL IS NOT FAR ENOUGH SOUTH. USED THE RAP FOR THE WIND FORECAST THEN BLENDED IN THE OTHER MODEL OUTPUT THAT FITS IN WITH THE RAP SCENARIO. AT THIS TIME THINK ANY THUNDERSTORMS WILL DEVELOP TO THE EAST AND SOUTH OF BOTH SITES. FOR MOST OF THE PERIOD EXPECT VFR CONDITIONS. HOWEVER MVFR CONDITIONS WILL BE POSSIBLE AFTER 06Z...ESPECIALLY WITH THE CEILINGS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...BULLER SHORT TERM...LOCKHART LONG TERM...BW AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
304 AM MDT WED JUN 24 2015 .SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY) ISSUED AT 154 PM MDT TUE JUN 23 2015 EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS RIDGE STILL IN PLACE ACROSS SOUTHERN PLAINS WITH WESTERLY ZONAL FLOW ACROSS THE NORTHERN PLAINS. WEAK SHORTWAVE TROUGHS AND MONSOONAL/PACIFIC FLOW CONTINUE TO ROTATE ALONG THE WESTERN PERIPHERY OF THE RIDGE AND INTO THE CENTRAL ROCKIES. AT THE SURFACE STATIONARY FRONT HAS LIFTED TO NEAR SCOTT CITY JUST SOUTH OF OUR CWA WITH STATIONARY FRONT ALONG FRONT RANGE. THIS AFTERNOON-TONIGHT...GUIDANCE CONTINUES TO SHOW WARM FRONT LIFTING NORTH THROUGH THE AFTERNOON AND EVENING AS LEE TROUGH DEEPENS. THUNDERSTORMS HAVE ALREADY DEVELOPED ACROSS SOUTH CENTRAL COLORADO. HIGH RES GUIDANCE CONTINUES TO SHOW CAP WEAKENING ALONG THE FRONT FROM THE WEST TO THE EAST...AND THUNDERSTORMS EITHER DEVELOPING OR MOVING INTO THE SW PART OF THE CWA SPREADING NORTH AND EAST THIS EVENING. WHILE PWATS AND TD VALUES ARE IMPRESSIVE...DEEP LAYER MIXING RATIOS/MOISTURE PROFILES ARE LESS THAN FAVORABLE FOR WIDESPREAD COVERAGE LOCALLY WITHOUT ORGANIZATION INTO MORE OF A CLUSTER FROM THE WEST. SHORTWAVE TROUGH ADVERTISED TO MOVE ACROSS CWA THIS EVENING COULD HELP WITH INITIATION...SO DESPITE THE DRY LAYERS ALOFT 20 TO 30 POPS STILL SEEMS REASONABLE. VEERING SHEER PROFILES IN THE 0-3KM LAYER COULD HELP SUPERCELL POTENTIAL ASSUMING THUNDERSTORMS DEVELOP THIS AFTERNOON/EARLY EVENING ALONG WARM FRONT BEFORE LOW LEVELS STABILIZE. AS EVENING PROGRESSES PROFILES FAVOR MAINLY ELEVATED THUNDERSTORMS...AND GOOD EFFECTIVE SHEER VALUES SHOULD STILL SUPPORT LARGE HAIL/DAMAGING WIND THREAT WITH ANY ONGOING ACTIVITY. WEDNESDAY...WARM FRONT STALLS NEAR THE KS/NE BORDER EARLY WEDNESDAY MORNING WITH MOISTURE POOLING NORTH OF THIS FRONT EARLY WEDNESDAY MORNING WHEN FOG/STRATUS COULD DEVELOP. GUIDANCE STILL SHOWING A POTENTIAL BUT I AM STILL NOT SURE VIS WILL BE LOW ENOUGH TO INCLUDE MENTION IN FORECAST...SO WILL MONITOR SHORT RANGE GUIDANCE/TRENDS. FRONT SETS UP ROUGHLY THROUGH THE CENTRAL PART OF THE CWA AS SURFACE LOW SHIFTS EAST WEDNESDAY AFTERNOON...WITH NEAR 100F TEMPS SOUTH OF THIS FRONT AND IN THE 90S TO THE NW. THIS FRONT WILL ACT AS A FOCUS FOR POSSIBLY THUNDERSTORM DEVELOPMENT IN THE AFTERNOON...AGAIN AIDED BY HEIGHT FALLS FROM WEAK SHORTWAVE ROTATING INTO THE REGION FROM THE WEST. I KEPT 20 POPS CONFINED TO THE SW IN THE AFTERNOON...THOUGH DEPENDING ON CAP STRENGTH I COULD SEE A ISOLATED THUNDERSTORM FURTHER EAST. NOT A STRONG SIGNAL IN THE AFTERNOON FURTHER EAST..SO I FAVOR STICKING WITH A CONSERVATIVE APPROACH FOR NOW. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 302 AM MDT WED JUN 24 2015 AT THE BEGINNING OF THE EXTENDED PERIOD MODELS ARE SHOWING THE LONGWAVE PATTERN AMPLIFYING THROUGH THE END OF THE PERIOD. A STRONG UPPER RIDGE IS LOCATED TO OUR WEST ALONG THE ROCKIES AND EXTENDING WELL INTO WESTERN CANADA. AT THE SAME TIME A DEEPENING TROUGH IS LOCATED OVER THE GREAT LAKES REGION AND EXTENDING IN THE SOUTHEASTERN U.S. THIS PATTERN SETS UP A PREDOMINANTLY NORTHWESTERLY UPPER FLOW OVER THE TRI STATE AREA. ON THE SURFACE THE LOCATED AREA WILL BE UNDER THE INFLUENCE OF A HIGH PRESSURE CENTER TO THE WEST OF THE CWA. THERE IS A SLIGHT CHANCES OF PRECIPITATION... MOSTLY IN THE FORM OF ISOLATED AFTERNOON AND EVENING CONVECTION... ASSOCIATED WITH THE OCCASIONAL SHORTWAVE TROUGHS THAT WILL MOVE THROUGH THE AREA FROM THE NORTH. OTHERWISE... EXPECT A MOSTLY DRY PERIOD WITH TEMPERATURES CLOSER TO NORMAL DUE TO THE NORTHERLY FLOW ALOFT AND A PERSISTENT EASTERLY SURFACE WINDS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1027 PM MDT TUE JUN 23 2015 CURRENT RADAR AND STORM TRENDS INDICATE INCREASING CHANCES THAT A STORM WILL MOVE INTO KMCK NEAR THE BEGINNING OF THIS FORECAST. A VICINITY THUNDERSTORM CANNOT BE RULED OUT NEAR KGLD AS WELL. OVERNIGHT STORMS WILL WEAKEN AND DISSIPATE. FORECAST SOUNDINGS INDICATE STRATUS AT KMCK TOWARD SUNRISE AND THEN BREAKING OUT AROUND 15Z. CONDITIONS MAY GET CLOSE TO MVFR AT KMCK. DURING THE DAY WEDNESDAY, EXPECT VFR CONDITIONS AT BOTH SITES WITH A SLIGHT CHANCE OF THUNDERSTORMS NEAR KGLD DURING THE EVENING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...BW AVIATION...FS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
152 AM CDT WED JUN 24 2015 ...UPDATE TO LONG TERM... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 132 AM CDT WED JUN 24 2015 EARLY MORNING CONVECTION NORTH OF THE I-70 CORRIDOR RELATED WELL WITH WHERE 850MB WARM AIR CONVECTION, LOCATED NEAR THE NOSE OF A 50KT 850MB JET, WAS OCCURRING JUST NORTH OF THE 700MB 12C TO 14C BAROCLINIC ZONE. THIS WAS ALSO JUST NORTH OF A SURFACE BOUNDARY WHICH EXTENDED FROM WEST TO EAST ACROSS NORTH CENTRAL KANSAS. THE RAP AND NAM WERE BOTH IN GOOD AGREEMENT EARLY THIS MORNING WITH KEEPING THIS CONVECTION NORTH OF ELLIS AND TREGO COUNTIES AS THESE THUNDERSTORMS WEAKEN DURING THE EARLY MORNING HOURS. AT THIS TIME WILL LEAN TOWARDS NOT INSERTING ANY MENTION OF EARLY MORNING CONVECTION IN THE HAYS OR WAKEENEY AREAS, HOWEVER WILL CONTINUE TO MONITOR THE ONGOING CONVECTION GIVEN THE DEVELOPING NORTHWEST TO SOUTHEAST ORIENTATION OF THE 700MB BAROCLINIC ZONE DURING THE PREDAWN HOURS. THE WEST TO EAST SURFACE FRONTAL BOUNDARY WILL MOVE NORTH ACROSS NORTHWEST AND NORTH CENTRAL KANSAS TODAY AS AN UPPER HIGH SHIFTS SLOWLY NORTH OUT OF NORTHERN OKLAHOMA INTO SOUTHERN KANSAS. THE WARM 700MB TEMPERATURE THAT WAS LOCATED OVER SOUTHWEST KANSAS AT 00Z WEDNESDAY WILL ALSO LIFT SLOWLY NORTH AND BY 00Z THURSDAY THESE WARM 700MB TEMPERATURES WILL EXTEND FROM EAST CENTRAL COLORADO INTO NORTH CENTRAL KANSAS. 850MB NET 24 HOUR TEMPERATURE TRENDS ACROSS SOUTHWEST KANSAS WILL CHANGE VERY LITTLE BETWEEN 00Z THURSDAY TO 00Z FRIDAY AS THE 700MB TEMPERATURES COOL BY A COUPLE OF DEGREES NEAR THE OKLAHOMA BORDER. BASED ON THESE TEMPERATURE TRENDS AND A MIXING DEPTH OF 800MB WILL STAY CLOSE TO THE PREVIOUS FORECAST WITH HIGHS RANGING FROM THE MID 90S IN SOUTH CENTRAL KANSAS TO AROUND 100 DEGREES ACROSS WEST CENTRAL AND NORTH CENTRAL KANSAS. CONVECTION LATE THURSDAY SHOULD BE CONFINED NEAR A SURFACE TROUGH OF LOW PRESSURE THAT WILL BE LOCATED WEST OF THE COLORADO BORDER AS A WEAK UPPER LEVEL TROUGH EXITS THE ROCKIES AND BEGINS TO CROSS THE CENTRAL HIGH PLAINS. 21Z THURSDAY AND 00Z FRIDAY CAPE VALUES FROM THE NAM INDICATED THAT THE INSTABILITY AXIS OF 2000 TO 3000 J/KG WILL STRETCH FROM EASTERN COLORADO INTO NORTHWEST KANSAS LATE DAY AND EARLY THIS EVENING WITH A 20 KNOT 0-6KM SHEAR. WIDELY SCATTERED THUNDERSTORMS WILL BE POSSIBLE IN THIS REGION LATE DAY BUT THESE STORMS ARE EXPECTED WEAKEN/DISSIPATE AS THEY MOVE EAST INTO A MORE STABLE AIR MASS AFTER SUNSET. TEMPERATURES TONIGHT WILL BE SIMILAR AS THE LOWS EARLY THIS MORNING GIVEN A SOUTHERLY WIND AT AROUND 15 MPH, HIGH CLOUDS SPREADING INCREASING ACROSS WEST CENTRAL/NORTH CENTRAL KANSAS AFTER MIDNIGHT, AND EARLY MORNING DEWPOINTS IN THE UPPER 50S TO LOWER 60S. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 150 AM CDT WED JUN 24 2015 PRECIP CHANCES PICK UP LATE THIS WEEK AS MEDIUM RANGE MODELS INDICATE A NORTHWEST FLOW ALOFT DEVELOPING ACROSS THE WESTERN HIGH PLAINS LATE THURSDAY WHILE AN UPPER LEVEL RIDGE OF HIGH PRESSURE BUILDS ACROSS THE GREAT BASIN. MEANWHILE, THE GFS AND ECWMF CONTINUE TO SHOW A SERIES OF H5 VORT MAXIMA COMING OFF THE AMPLIFYING RIDGE AXIS AND DIGGING SOUTHEAST OUT OF THE NORTHERN ROCKIES INTO THE PLAINS OF SOUTH DAKOTA AND NEBRASKA. AN ATTENDANT COLD FRONT IS PROJECTED TO PUSH SOUTHWARD INTO WESTERN KANSAS SOMETIME THURSDAY NIGHT/EARLY FRIDAY PROVIDING THE FOCUS FOR POTENTIAL THUNDERSTORMS ACROSS PORTIONS OF CENTRAL AND WESTERN KANSAS. THE NORTHWEST FLOW ALOFT WILL INCREASE SOME AS AN UPPER LEVEL JET CRESTING THE RIDGE AXIS OUT WEST, DIGS SOUTHEAST INTO THE SOUTHERN DAKOTAS AND NEBRASKA. ALONG WITH AMPLE LOW/MID LEVEL MOISTURE AND INSTABILITY PRESENT, THE POTENTIAL FOR THUNDERSTORMS WILL INCREASE THURSDAY NIGHT INTO FRIDAY. THUNDERSTORM CHANCES WILL LESSEN SATURDAY AS THE UPPER LEVEL RIDGE CONTINUES TO AMPLIFY OUT WEST WHILE THE AFOREMENTIONED COLD FRONT PUSHES FURTHER SOUTH INTO NORTH TEXAS. THERE IS AN OUTSIDE SHOT AT ISOLATED THUNDERSTORMS COMING OFF THE ROCKIES WITHIN A SOUTHEASTERLY UPSLOPE FLOW AND POTENTIALLY DRIFTING INTO EXTREME SOUTHWEST KANSAS SATURDAY EVENING. SEASONAL TEMPERATURES WILL CONTINUE THURSDAY EVEN AS A WEAK COLD FRONT/TROUGH AXIS BEGINS PUSHING INTO NORTHWEST AND NORTH CENTRAL KANSAS. SO LOOK FOR HIGHS BACK UP INTO THE 90S(F) ACROSS MUCH OF CENTRAL AND SOUTHWEST KANSAS THURSDAY AFTERNOON. THE COLD FRONT WILL PUSH FURTHER SOUTH ACROSS SOUTHWEST AND CENTRAL KANSAS INTO OKLAHOMA LATE THURSDAY NIGHT ALLOWING SLIGHTLY COOLER AIR TO FILTER SOUTHWARD INTO THE AREA. THIS WILL LOWER HIGHS TO ONLY THE 80S(F) FRIDAY AFTERNOON. HIGHS WILL GRADUALLY REBOUND THROUGHOUT THE WEEKEND AS A LOW LEVEL SOUTH TO SOUTHEASTERLY FLOW RETURNS TO WESTERN KANSAS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1201 AM CDT WED JUN 24 2015 VFR CONDITIONS ARE EXPECTED OVERNIGHT AS ONLY MID AND HIGH LEVEL MOISTURE PRECEDES AN UPPER LEVEL TROUGH AS IT CROSSES WESTERN KANSAS. AS THIS UPPER LEVEL DISTURBANCE PASSES SKIES WILL CLEAR FROM WEST TO EAST EARLY THURSDAY MORNING. SOUTH TO SOUTHWEST WINDS OVERNIGHT WILL BE AT 10 TO 15 KNOTS. RAP AND NAM WERE SIMILAR WITH HAVING A 50 KNOT LOW LEVEL JET ACROSS SOUTHWEST KANSAS BETWEEN 06Z AND 12Z. THIS JET AXIS APPEARS TO BE LOCATED NEAR AND WEST OF GCK AND HYS SO WILL INSERT AS WIND SHEAR GROUP INTO THESE TAFS THROUGH 12Z THURSDAY. BY LATE MORNING THESE SOUTHERLY WINDS INCREASE INTO THE 20 TO NEAR 25 KNOTS RANGE AS STRONGER WINDS LOCATED IN THE 900MB TO 850MB LEVEL BEGIN TO MIX DOWN TO THE SURFACE. THESE GUSTY WINDS WILL THEN CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... DDC 97 71 96 67 / 0 0 30 30 GCK 98 71 95 65 / 0 10 30 30 EHA 95 69 95 65 / 0 0 30 30 LBL 96 70 97 67 / 0 0 30 30 HYS 100 73 92 65 / 10 10 30 40 P28 98 73 97 70 / 0 0 30 30 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BURGERT LONG TERM...JJOHNSON AVIATION...BURGERT
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
136 AM CDT WED JUN 24 2015 ...UPDATED SHORT TERM DISCUSSION .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 132 AM CDT WED JUN 24 2015 EARLY MORNING CONVECTION NORTH OF THE I-70 CORRIDOR RELATED WELL WITH WHERE 850MB WARM AIR CONVECTION, LOCATED NEAR THE NOSE OF A 50KT 850MB JET, WAS OCCURRING JUST NORTH OF THE 700MB 12C TO 14C BAROCLINIC ZONE. THIS WAS ALSO JUST NORTH OF A SURFACE BOUNDARY WHICH EXTENDED FROM WEST TO EAST ACROSS NORTH CENTRAL KANSAS. THE RAP AND NAM WERE BOTH IN GOOD AGREEMENT EARLY THIS MORNING WITH KEEPING THIS CONVECTION NORTH OF ELLIS AND TREGO COUNTIES AS THESE THUNDERSTORMS WEAKEN DURING THE EARLY MORNING HOURS. AT THIS TIME WILL LEAN TOWARDS NOT INSERTING ANY MENTION OF EARLY MORNING CONVECTION IN THE HAYS OR WAKEENEY AREAS, HOWEVER WILL CONTINUE TO MONITOR THE ONGOING CONVECTION GIVEN THE DEVELOPING NORTHWEST TO SOUTHEAST ORIENTATION OF THE 700MB BAROCLINIC ZONE DURING THE PREDAWN HOURS. THE WEST TO EAST SURFACE FRONTAL BOUNDARY WILL MOVE NORTH ACROSS NORTHWEST AND NORTH CENTRAL KANSAS TODAY AS AN UPPER HIGH SHIFTS SLOWLY NORTH OUT OF NORTHERN OKLAHOMA INTO SOUTHERN KANSAS. THE WARM 700MB TEMPERATURE THAT WAS LOCATED OVER SOUTHWEST KANSAS AT 00Z WEDNESDAY WILL ALSO LIFT SLOWLY NORTH AND BY 00Z THURSDAY THESE WARM 700MB TEMPERATURES WILL EXTEND FROM EAST CENTRAL COLORADO INTO NORTH CENTRAL KANSAS. 850MB NET 24 HOUR TEMPERATURE CHANGE ACROSS SOUTHWEST KANSAS WILL CHANGE VERY LITTLE BETWEEN 00Z WEDNESDAY TO 00Z THURSDAY AS THE 700MB TEMPERATURES COOL BY A COUPLE OF DEGREES NEAR THE OKLAHOMA BORDER. BASED ON THESE TEMPERATURE TRENDS AND A MIXING DEPTH OF 800MB WILL STAY CLOSE TO THE PREVIOUS FORECAST WITH HIGHS RANGING FROM THE MID 90S IN SOUTH CENTRAL KANSAS TO AROUND 100 DEGREES ACROSS WEST CENTRAL AND NORTH CENTRAL KANSAS. CONVECTION LATE WEDNESDAY SHOULD BE CONFINED NEAR A SURFACE TROUGH OF LOW PRESSURE THAT WILL BE LOCATED WEST OF THE COLORADO BORDER AS A WEAK UPPER LEVEL TROUGH EXITS THE ROCKIES AND BEGINS TO CROSS THE CENTRAL HIGH PLAINS. 21Z WEDNESDAY AND 00Z THURSDAY CAPE VALUES FROM THE NAM INDICATED THAT THE INSTABILITY AXIS OF 2000 TO 3000 J/KG WILL STRETCH FROM EASTERN COLORADO INTO NORTHWEST KANSAS LATE DAY AND EARLY THIS EVENING WITH A 20 KNOT 0-6KM SHEAR. WIDELY SCATTERED THUNDERSTORMS WILL BE POSSIBLE IN THIS REGION LATE DAY BUT THESE STORMS ARE EXPECTED WEAKEN/DISSIPATE AS THEY MOVE EAST INTO A MORE STABLE AIR MASS AFTER SUNSET. TEMPERATURES TONIGHT WILL BE SIMILAR AS THE LOWS EARLY THIS MORNING GIVEN A SOUTHERLY WIND AT AROUND 15 MPH, HIGH CLOUDS SPREADING INCREASING ACROSS WEST CENTRAL/NORTH CENTRAL KANSAS AFTER MIDNIGHT, AND EARLY MORNING DEWPOINTS IN THE UPPER 50S TO LOWER 60S. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 201 PM CDT TUE JUN 23 2015 ECMWF SHOWS SOME CONVECTION DEVELOPING ACROSS THE EASTERN ZONES THURSDAY EVENING. THIS MATCHES THE TAIL END OF THE 4 KM NAM. WILL HAVE CHANCE POPS HERE AND SLIGHT POPS TO THE WEST. WIND AND HAIL MAY BE POSSIBLE WITH THIS ACTIVITY AS THERE IS LOW END SHEAR AND MODERATE CAPE. LOWS WILL BE MORE MILD FOR FAR WESTERN KANSAS FRIDAY MORNING AS COOLER AIR ADVECTS IN. SPEAKING OF, HIGHS FRIDAY WILL BE COOLER WITH 80S INSTEAD OF 90S POST FRONTAL. LOWS IN THE 60S ARE EXPECTED FOR SATURDAY MORNING. ANOTHER DAY WITH A BREAK IN THE HEAT IS EXPECTED FOR SATURDAY WITH HIGHS IN THE 80S AGAIN. FOR NEXT WEEK, THE WARM SECTOR WILL LIFT NORTHWARD WITH 90S RETURNING. THE REALLY INTENSE HEAT LOOKS TO REMAIN WEST OF HERE AS THE RIDGE AMPLIFIES OUT WEST AND NORTHERLY FLOW DEVELOPS ACROSS KANSAS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1201 AM CDT WED JUN 24 2015 VFR CONDITIONS ARE EXPECTED OVERNIGHT AS ONLY MID AND HIGH LEVEL MOISTURE PRECEDES AN UPPER LEVEL TROUGH AS IT CROSSES WESTERN KANSAS. AS THIS UPPER LEVEL DISTURBANCE PASSES SKIES WILL CLEAR FROM WEST TO EAST EARLY THURSDAY MORNING. SOUTH TO SOUTHWEST WINDS OVERNIGHT WILL BE AT 10 TO 15 KNOTS. RAP AND NAM WERE SIMILAR WITH HAVING A 50 KNOT LOW LEVEL JET ACROSS SOUTHWEST KANSAS BETWEEN 06Z AND 12Z. THIS JET AXIS APPEARS TO BE LOCATED NEAR AND WEST OF GCK AND HYS SO WILL INSERT AS WIND SHEAR GROUP INTO THESE TAFS THROUGH 12Z THURSDAY. BY LATE MORNING THESE SOUTHERLY WINDS INCREASE INTO THE 20 TO NEAR 25 KNOTS RANGE AS STRONGER WINDS LOCATED IN THE 900MB TO 850MB LEVEL BEGIN TO MIX DOWN TO THE SURFACE. THESE GUSTY WINDS WILL THEN CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... DDC 97 71 96 68 / 0 0 20 30 GCK 98 71 95 66 / 0 10 20 20 EHA 98 69 95 66 / 0 0 20 20 LBL 97 70 97 68 / 0 0 20 20 HYS 100 73 92 66 / 10 10 40 40 P28 97 73 97 71 / 0 0 20 40 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BURGERT LONG TERM...99 AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1204 AM CDT WED JUN 24 2015 ...UPDATED SYNOPSIS AND AVIATION DISCUSSION... .SYNOPSIS... ISSUED AT 1201 AM CDT WED JUN 24 2015 AT 00Z WEDNESDAY A 500MB HIGH EXTENDED FROM NEAR THE FOUR CORNERS REGION TO EASTERN OKLAHOMA NORTH OF THIS UPPER HIGH A WESTERLY FLOW EXTENDED FROM THE ROCKIES TO THE MISSISSIPPI VALLEY. WATER VAPOR LOOP AND 00Z WEDNESDAYS UPPER AIR ANALYSIS INDICATED SEVERAL WEAK UPPER LEVEL TROUGH EMBEDDED IN THIS WESTERLY FLOW. OVER THE CENTRAL HIGH PLAINS A SURFACE WARM FRONT EXTENDED FROM AN AREA OF LOW PRESSURE OVER CENTRAL COLORADO TO EAST CENTRAL KANSAS. 850MB TEMPERATURES EARLIER THIS EVENING INDICATED A BAROCLINIC ZONE STRETCHED FROM WESTERN NEBRASKA TO NORTH EASTERN KANSAS AND TEMPERATURES ACROSS THIS BAROCLNIC ZONE RANGE FROM +26C AT DODGE CITY TO +14C AT OMAHA. 700MB TEMPERATURES VARIED FROM +12C AT TOPEKA TO +16C AT DODGE CITY TO +17C AT DENVER. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 324 PM CDT TUE JUN 23 2015 A DRY FORECAST WILL CONTINUE TONIGHT THROUGH WEDNESDAY AS AN EAST-WEST ORIENTED MID-UPPER TROPOSPHERIC ANTICYCLONE WILL BASICALLY REMAIN UNCHANGED THROUGH WEDNESDAY. WE WILL CONTINUE TO SEE STRONG FAIRLY STRONG DIURNAL WINDS ON WEDNESDAY, MUCH LIKE TODAY. THE MOST INTENSE THERMAL RIDGE WILL BE FROM WEST CENTRAL INTO NORTHWEST KANSAS ON WEDNESDAY, AND THIS WILL BE WHERE THE WARMEST TEMPERATURES WILL BE IN THE FORECAST...AROUND 100 FROM NEAR SYRACUSE NORTHEAST TO WAKEENEY-HAYS. OTHERWISE, MID TO UPPER 90S CAN BE EXPECTED ELSEWHERE. THUNDERSTORMS DEVELOPING ACROSS THE HIGHER TERRAIN OF COLORADO LATE THIS AFTERNOON/EVENING WILL MOVE NORTHEAST AND ARE EXPECTED TO REMAIN OUTSIDE OF THE DODGE CITY NWS AREA OF FORECAST RESPONSIBILITY. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 201 PM CDT TUE JUN 23 2015 ECMWF SHOWS SOME CONVECTION DEVELOPING ACROSS THE EASTERN ZONES THURSDAY EVENING. THIS MATCHES THE TAIL END OF THE 4 KM NAM. WILL HAVE CHANCE POPS HERE AND SLIGHT POPS TO THE WEST. WIND AND HAIL MAY BE POSSIBLE WITH THIS ACTIVITY AS THERE IS LOW END SHEAR AND MODERATE CAPE. LOWS WILL BE MORE MILD FOR FAR WESTERN KANSAS FRIDAY MORNING AS COOLER AIR ADVECTS IN. SPEAKING OF, HIGHS FRIDAY WILL BE COOLER WITH 80S INSTEAD OF 90S POST FRONTAL. LOWS IN THE 60S ARE EXPECTED FOR SATURDAY MORNING. ANOTHER DAY WITH A BREAK IN THE HEAT IS EXPECTED FOR SATURDAY WITH HIGHS IN THE 80S AGAIN. FOR NEXT WEEK, THE WARM SECTOR WILL LIFT NORTHWARD WITH 90S RETURNING. THE REALLY INTENSE HEAT LOOKS TO REMAIN WEST OF HERE AS THE RIDGE AMPLIFIES OUT WEST AND NORTHERLY FLOW DEVELOPS ACROSS KANSAS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1201 AM CDT WED JUN 24 2015 VFR CONDITIONS ARE EXPECTED OVERNIGHT AS ONLY MID AND HIGH LEVEL MOISTURE PRECEDES AN UPPER LEVEL TROUGH AS IT CROSSES WESTERN KANSAS. AS THIS UPPER LEVEL DISTURBANCE PASSES SKIES WILL CLEAR FROM WEST TO EAST EARLY THURSDAY MORNING. SOUTH TO SOUTHWEST WINDS OVERNIGHT WILL BE AT 10 TO 15 KNOTS. RAP AND NAM WERE SIMILAR WITH HAVING A 50 KNOT LOW LEVEL JET ACROSS SOUTHWEST KANSAS BETWEEN 06Z AND 12Z. THIS JET AXIS APPEARS TO BE LOCATED NEAR AND WEST OF GCK AND HYS SO WILL INSERT AS WIND SHEAR GROUP INTO THESE TAFS THROUGH 12Z THURSDAY. BY LATE MORNING THESE SOUTHERLY WINDS INCREASE INTO THE 20 TO NEAR 25 KNOTS RANGE AS STRONGER WINDS LOCATED IN THE 900MB TO 850MB LEVEL BEGIN TO MIX DOWN TO THE SURFACE. THESE GUSTY WINDS WILL THEN CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... DDC 71 96 68 87 / 0 10 10 20 GCK 71 95 66 87 / 10 10 10 20 EHA 69 95 66 88 / 0 10 10 20 LBL 70 97 68 88 / 0 10 10 30 HYS 73 92 66 85 / 10 10 10 20 P28 73 97 71 90 / 0 10 10 30 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BURGERT SHORT TERM...UMSCHEID LONG TERM...99 AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1041 PM MDT TUE JUN 23 2015 .SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY) ISSUED AT 154 PM MDT TUE JUN 23 2015 EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS RIDGE STILL IN PLACE ACROSS SOUTHERN PLAINS WITH WESTERLY ZONAL FLOW ACROSS THE NORTHERN PLAINS. WEAK SHORTWAVE TROUGHS AND MONSOONAL/PACIFIC FLOW CONTINUE TO ROTATE ALONG THE WESTERN PERIPHERY OF THE RIDGE AND INTO THE CENTRAL ROCKIES. AT THE SURFACE STATIONARY FRONT HAS LIFTED TO NEAR SCOTT CITY JUST SOUTH OF OUR CWA WITH STATIONARY FRONT ALONG FRONT RANGE. THIS AFTERNOON-TONIGHT...GUIDANCE CONTINUES TO SHOW WARM FRONT LIFTING NORTH THROUGH THE AFTERNOON AND EVENING AS LEE TROUGH DEEPENS. THUNDERSTORMS HAVE ALREADY DEVELOPED ACROSS SOUTH CENTRAL COLORADO. HIGH RES GUIDANCE CONTINUES TO SHOW CAP WEAKENING ALONG THE FRONT FROM THE WEST TO THE EAST...AND THUNDERSTORMS EITHER DEVELOPING OR MOVING INTO THE SW PART OF THE CWA SPREADING NORTH AND EAST THIS EVENING. WHILE PWATS AND TD VALUES ARE IMPRESSIVE...DEEP LAYER MIXING RATIOS/MOISTURE PROFILES ARE LESS THAN FAVORABLE FOR WIDESPREAD COVERAGE LOCALLY WITHOUT ORGANIZATION INTO MORE OF A CLUSTER FROM THE WEST. SHORTWAVE TROUGH ADVERTISED TO MOVE ACROSS CWA THIS EVENING COULD HELP WITH INITIATION...SO DESPITE THE DRY LAYERS ALOFT 20 TO 30 POPS STILL SEEMS REASONABLE. VEERING SHEER PROFILES IN THE 0-3KM LAYER COULD HELP SUPERCELL POTENTIAL ASSUMING THUNDERSTORMS DEVELOP THIS AFTERNOON/EARLY EVENING ALONG WARM FRONT BEFORE LOW LEVELS STABILIZE. AS EVENING PROGRESSES PROFILES FAVOR MAINLY ELEVATED THUNDERSTORMS...AND GOOD EFFECTIVE SHEER VALUES SHOULD STILL SUPPORT LARGE HAIL/DAMAGING WIND THREAT WITH ANY ONGOING ACTIVITY. WEDNESDAY...WARM FRONT STALLS NEAR THE KS/NE BORDER EARLY WEDNESDAY MORNING WITH MOISTURE POOLING NORTH OF THIS FRONT EARLY WEDNESDAY MORNING WHEN FOG/STRATUS COULD DEVELOP. GUIDANCE STILL SHOWING A POTENTIAL BUT I AM STILL NOT SURE VIS WILL BE LOW ENOUGH TO INCLUDE MENTION IN FORECAST...SO WILL MONITOR SHORT RANGE GUIDANCE/TRENDS. FRONT SETS UP ROUGHLY THROUGH THE CENTRAL PART OF THE CWA AS SURFACE LOW SHIFTS EAST WEDNESDAY AFTERNOON...WITH NEAR 100F TEMPS SOUTH OF THIS FRONT AND IN THE 90S TO THE NW. THIS FRONT WILL ACT AS A FOCUS FOR POSSIBLY THUNDERSTORM DEVELOPMENT IN THE AFTERNOON...AGAIN AIDED BY HEIGHT FALLS FROM WEAK SHORTWAVE ROTATING INTO THE REGION FROM THE WEST. I KEPT 20 POPS CONFINED TO THE SW IN THE AFTERNOON...THOUGH DEPENDING ON CAP STRENGTH I COULD SEE A ISOLATED THUNDERSTORM FURTHER EAST. NOT A STRONG SIGNAL IN THE AFTERNOON FURTHER EAST..SO I FAVOR STICKING WITH A CONSERVATIVE APPROACH FOR NOW. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 318 PM MDT TUE JUN 23 2015 FORECAST PROBLEMS WILL BE CHANCES OF THUNDERSTORMS THROUGH FRIDAY. SATELLITE SHOWING A PROGRESSIVE/NEAR ZONAL FLOW FROM THE PACIFIC INTO THE WESTERN ATLANTIC. BROAD UPPER RIDGE NOW IN PLACE OVER MOST OF THE SOUTHERN HALF OF THE COUNTRY. AT JET LEVEL...MODELS START OUT FINE. AT MID LEVELS...THE CANADIAN AND GFS WERE DOING A LITTLE BETTER THAN THE NAM AND ECMWF. THE ECMWF WAS DOING A LITTLE BETTER THAN THE SREF/GFS/NAM ON THE SURFACE WIND AND PRESSURE FIELD. THE SREF/ECMWF/NAM WERE DOING A LITTLE BETTER THAN THE REST OF THE OUTPUT ON THE LOW LEVEL THERMAL FIELD. WEDNESDAY NIGHT...RIGHT REAR QUADRANT OF JET CONTINUES ACROSS THE NORTHERN HALF OF THE AREA THROUGH THE NIGHT ALTHOUGH IT WEAKENS A LITTLE LATER IN THE NIGHT. BY LATE IN THE AFTERNOON THE FRONT HAS SAGGED DOWN THROUGH ABOUT THE WHOLE AREA EXCEPT MAYBE FOR THE SOUTHERN FRINGE. MID LEVEL SHORTWAVE/LIFT MOVE AFFECT THE NORTHWEST HALF OF THE AREA THROUGH MIDDLE OF THE NIGHT BEFORE MOVING OUT OF THE NORTHERN PORTION DURING THE OVERNIGHT HOURS. SO THE NORTHWEST HALF OF THE AREA WILL HAVE THE HIGHEST POPS ESPECIALLY THE FAR WEST AND NORTH. THURSDAY/THURSDAY NIGHT... SHORTWAVE TROUGHS IN NORTHWEST FLOW IS ALWAYS A TRICKY AND POTENTIALLY ACTIVE SETUP FOR THE AREA. THERE LOOKS TO BE SOME WEAK LIFT FROM THE RIGHT REAR QUADRANT DURING THE AFTERNOON. MAIN JET LOOKS TO STAY NORTH OF THE AREA DURING THE NIGHT. THE FRONT INITIALLY STAYS CLOSE TO THE SOUTHERN PORTION OF THE AREA BEFORE MOVING EVEN FARTHER SOUTH. MULTIPLE SHORTWAVE TROUGHS MAKE AFTERNOON AND NIGHTTIME PRECIPITATION FORECAST MESSY. ONE SHORTWAVE WILL AFFECT THE SOUTHEAST PORTION OF THE AREA DURING THE AFTERNOON AS ANOTHER WAVE APPROACHES THE FAR WEST. ALSO POST FRONTAL UPSLOPE OR THE PROXIMITY OF THE BOUNDARY TO THE WESTERN PORTION OF THE AREA WILL HELP DEVELOP STORMS. SO AT THIS TIME WILL HAVE SLIGHT CHANCE TO LOW CHANCE POPS ALONG THE SOUTHEAST AND WESTERN PORTIONS OF THE AREA. FOR THE NIGHT...A DECENT BAROCLINIC ZONE LOOKS TO MOVE ACROSS IN ADVANCE OF A FEW SHORTWAVE TROUGHS. ONE SHORTWAVE TROUGH MOVES ACROSS THE SOUTHWEST PORTION WITH ANOTHER MOVING ACROSS THE NORTHERN PORTION. COMBINATION OF THE BAROCLINIC ZONE AND FAVORABLE THETA-E LAPSE RATES SHOULD ALLOW FOR A GOOD RESPONSE TO THE LIFT. SO CHANCE POPS WILL TRANSITION FROM NORTHWEST TO SOUTHEAST DURING THIS TIME. SEE THE POTENTIAL FOR THE POPS TO BE RAISED FROM THIS. AS STATED ABOVE MOST IF NOT ALL OF THE AREA WILL BE IN POST FRONTAL UPSLOPE FLOW AND LINGERING CLOUD COVER. AS A RESULT THE HIGH TEMPERATURES WILL BE COOLER. DEPENDING ON HOW LONG LOW LEVEL CLOUD COVER LASTS...TEMPERATURES MAY NEED TO BE MADE EVEN COOLER THAN WHAT IS IN THERE NOW. FRIDAY...MAIN JET REMAINS NORTH OF THE AREA. DECENT BAROCLINIC ZONE AND COLD AIR ADVECTION WILL CONTINUE TO MOVE ACROSS DURING THE DAY. SHORTWAVES WILL ROTATE THROUGH THE NORTHERLY FLOW ALOFT WITH A MODERATELY STRONG SHORTWAVE MOVING THROUGH FROM LATE IN THE MORNING THROUGH MID AFTERNOON. SO HAVE SLIGHT TO CHANCE POPS FOR NOW. COLD AIR ALOFT...POST FRONTAL SURFACE WINDS...CLOUD COVER AND PRECIPITATION WILL HELP KEEP TEMPERATURES FROM RISING TOO MUCH. TEMPERATURES LOOK TO BE COOLER THAN THE PREVIOUS DAY BUT ONCE AGAIN THE POTENTIAL IS THERE AGAIN TO HAVE TO MAKE THESE TEMPERATURES COOLER. FRIDAY NIGHT THROUGH TUESDAY...PATTERN WILL AMPLIFY THROUGH THE PERIOD WITH A RATHER STRONG/SHARP UPPER RIDGE TO OUR WEST. MODELS ARE IN GOOD AGREEMENT WITH THIS. PERIODIC SHORTWAVE TROUGHS ALONG WITH THE ASSOCIATED SURFACE FEATURES WILL MOVE THROUGH IN THE NORTHWEST TO EVENTUALLY NORTH FLOW ALOFT. HARD TO RULE OUT PRECIPITATION IN THIS PERIOD. AT THIS TIME...IT LOOKS LIKE ISOLATED AFTERNOON AND EVENING CONVECTION...MAINLY IN MY WESTERN/NORTHERN PORTIONS THROUGH THE PERIOD. THE CRH_INIT DEPICTED THIS SCENARIO NICELY AND DID NOT CHANGE THE POPS THAT I WAS GIVEN. THE ONLY TRULY DRY PERIOD LOOKS TO BE MONDAY AND MONDAY NIGHT. TEMPERATURES SHOULD NOT GET TOO HOT OR WAY ABOVE NORMAL DUE TO THE NORTHERLY FLOW ALOFT AND PERSISTENT EASTERLY SURFACE WINDS OF SOME SORT. THIS IS ALSO DEPICTED NICELY BY THE INIT AND DID NOT CHANGE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1027 PM MDT TUE JUN 23 2015 CURRENT RADAR AND STORM TRENDS INDICATE INCREASING CHANCES THAT A STORM WILL MOVE INTO KMCK NEAR THE BEGINNING OF THIS FORECAST. A VICINITY THUNDERSTORM CANNOT BE RULED OUT NEAR KGLD AS WELL. OVERNIGHT STORMS WILL WEAKEN AND DISSIPATE. FORECAST SOUNDINGS INDICATE STRATUS AT KMCK TOWARD SUNRISE AND THEN BREAKING OUT AROUND 15Z. CONDITIONS MAY GET CLOSE TO MVFR AT KMCK. DURING THE DAY WEDNESDAY, EXPECT VFR CONDITIONS AT BOTH SITES WITH A SLIGHT CHANCE OF THUNDERSTORMS NEAR KGLD DURING THE EVENING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...BULLER AVIATION...FS
AREA FORECAST DISCUSSION
NWS JACKSON KY
935 PM EDT THU JUN 25 2015 .UPDATE... ISSUED AT 935 PM EDT THU JUN 25 2015 SHOWERS AND STORMS CONTINUE ACROSS NORTHEASTERN KENTUCKY THIS EVENING...WITH MOST OF THEM PRODUCING HEAVY RAINFALL AND FREQUENT LIGHTNING. STORMS EARLIER THIS AFTERNOON PRODUCED UP TO QUARTER SIZED HAIL...AND THIS REMAINS POSSIBLE TONIGHT AS WELL. SOME PATCHY FOG/MIST HAS ALREADY SET IN AT JKL DUE TO THE MULTIPLE ROUNDS OF RAIN THIS EVENING...SO HAVE ADDED IN PATCHY VALLEY FOG TO THE NORTHERN HALF OF THE CWA. OTHERWISE...ONLY MINOR ADJUSTMENTS WERE MADE TO THE T/TD GRIDS TO ALIGN THEM WITH OBS. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS. UPDATE ISSUED AT 640 PM EDT THU JUN 25 2015 STRONG TO SEVERE STORMS HAVE FINALLY STARTED TO DEVELOP ACROSS EASTERN KENTUCKY BUT REMAIN MOSTLY SCATTERED IN NATURE. EXPECT THE COVERAGE TO INCREASE THROUGHOUT THE EVENING HOURS SINCE THE CAP IS NOW BROKEN. DECIDED TO BUMP POPS UP TO INCLUDE AT LEAST A SLIGHT CHANCE POP ACROSS OUR SOUTHERN COUNTIES...AS WELL AS ADJUST T/TD GRIDS TO ALIGN THEM WITH RECENT OBS. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 359 PM EDT THU JUN 25 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE A STATIONARY BOUNDARY DRAPED ACROSS CENTRAL AND EASTERN KENTUCKY. CURRENT VISIBLE SHOT ACROSS THE AREA SHOWS SOME BREAKS IN THE CLOUD COVER ACROSS THE AREA. THIS HAS ALLOWED SOME INCREASED HEATING DESPITE THE CAP AND LACK OF INSTABILITY FROM THIS MORNINGS MCS. IF THE BREAKS AND INCREASED HEATING CONTINUES...SOME CONVECTION MAY BEGIN TO DEVELOP IN THE NEXT COUPLE OF HOURS. THE ISSUE HERE IS IF THE CAP AT 800MB IS BROKEN. THE HRRR HAS BEEN SLIGHTLY LESS STELLAR HINTING AT CONVECTION ALL AFTERNOON BUT TO NO AVAIL. SOME SHOWER ACTIVITY HAS DEVELOPED UPSTREAM IN SOUTHERN IN AND WESTERN KY SO WILL INTRODUCE SOME POPS INTO EASTERN KENTUCKY AFTER 21Z THIS AFTERNOON. HEADING INTO TONIGHT...THE NEXT CLUSTER OF STORMS DEVELOPS AND BEGINS TO TRACK SOUTHEAST INTO KY. THE FORMATION OF THIS AREA SHOULD BEGIN IN CENTRAL KY OR EVEN A BIT FURTHER WEST. IT IS WORTH MENTIONING THAT MODELS HAVE BEEN LESS THAN STELLAR PICKING OUT THIS DEVELOPMENT. THOUGH WITH TRENDS AND COLLABORATION WITH NEIGHBORING OFFICES...WILL BE INTRODUCING LIKELY POPS INTO EASTERN KENTUCKY SHORTLY AFTER 00Z BUT DEVELOPMENT AND A STARTING POINT FOR CONVECTIVE INITIATION IS A BIT OF A TOUGH CALL. TOMORROW...A STRONGER WAVE DIPS SOUTH INTO THE LOWER OH VALLEY CROSSING OVER THE RIDGE OUT WEST AND MAKES FOR AN INTERESTING SITUATION FOR KY ON FRIDAY EVENING AND FRIDAY NIGHT. WITH THIS...THE WARM FRONT WITH A STRONG SOUTHERLY SURGE PUSHES NORTH THROUGH THE AREA. AHEAD OF THIS SHOULD BE STRONG CONVECTION AND POSSIBLY SEVERE THUNDERSTORMS. EARLY MORNING CONVECTION MAY HINDER THIS A BIT BUT THE WARM AND MOIST AIR SURGING FROM THE SOUTH SHOULD MAKE FRIDAY EVENING AND INTO FRIDAY NIGHT QUITE INTERESTING. WILL MENTION THIS PERIOD IN THE HWO AS THIS WILL BEGIN AN ACTIVE PERIOD. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 359 PM EDT THU JUN 25 2015 MODELS APPEAR TO BE IN GOOD AGREEMENT WITH MID AND UPPER LEVEL FLOW THROUGH THE EXTENDED. WE FIND OURSELVES UNDER THE INFLUENCE OF A HIGH AMPLITUDE PATTERN WITH A MEAN EAST CONUS TROUGH AND WEST CONUS RIDGE. AS SUCH WE CAN EXPECT BELOW NORMAL TEMPERATURES THROUGH THE PERIOD AND IN GENERAL AN UNSETTLED WEATHER PATTERN. MODEL GUIDANCE IS IN GOOD AGREEMENT WITH A POSITIVELY TILTED TROUGH CUTTING OFF ACROSS THE GREAT LAKES REGION BY EARLY SATURDAY. THIS FEATURE WILL EVENTUALLY TRACK EAST...BECOMING NEGATIVELY TILTED AS IT MOVES INTO SOUTHERN NEW ENGLAND STATES SUNDAY. ADDITIONAL SHORTWAVE ENERGY DIGS OUT A REINFORCING TROUGH OVER OUR REGION BY MONDAY WHICH ONLY GRADUALLY LIFTS OUT TO THE NORTHEAST BY THE END OF THE FORECAST WINDOW. BY THEN THERE IS A TENDENCY FOR THE PATTERN TO BECOME LESS AMPLIFIED AND A BIT MORE ZONALLY ORIENTED AS WESTERN CONUS RIDGE SHIFTS OUT INTO THE PACIFIC AND ADDITIONAL SHORTWAVE ENERGY DROPS INTO THE UPPER MIDWEST. AT THE SURFACE...THE INITIAL TROUGH/CUT OFF LOW WILL AID IN DEVELOPING A SURFACE LOW ACROSS THE WESTERN OHIO VALLEY AT THE START OF THE PERIOD. THIS RELATIVELY DEEP AND WELL ORGANIZED SFC LOW WILL RIDE UP THE OHIO VALLEY OVER THE WEEKEND...WITH A TRAILING COLD FRONT ADVANCING ACROSS OUR AREA SATURDAY MORNING. ANOTHER FRONTAL SYSTEM WILL SWEEP THROUGH THE REGION AT THE START OF THE WEEK...LATE MONDAY INTO TUESDAY. ONCE AGAIN...THIS PATTERN WILL ENSURE BELOW NORMAL TEMPS THROUGH THE PERIOD WITH HIGHS IN THE MID 70S TO LOWER 80S AND LOWS MAINLY FALLING INTO THE 50S TO LOWER 60S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 804 PM EDT THU JUN 25 2015 SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER THE PAST COUPLE OF HOURS...MAINLY IN AND AROUND THE JKL...SJS...AND SME TAF SITES. EXPECT THESE STORMS TO GRADUALLY WEAKEN WITH THE LOSS OF DAYTIME HEATING. BUT ANTICIPATE CIGS/VIS TO LOWER OVERNIGHT TONIGHT DUE TO LEFTOVER SHOWERS AND FOG DEVELOPMENT...WITH ALTERNATE MIN VIS POSSIBLE AT THE SJS...SME AND LOZ TAF SITES AND MVFR VIS AT THE JKL AND SYM TAF SITES. A LULL IN PRECIP DURING THE MORNING HOURS WILL ALLOW FOR VFR CONDITIONS FOR A TIME ON FRIDAY...BEFORE AFTERNOON THUNDERSTORM ACTIVITY DEVELOPS ONCE AGAIN. WINDS WILL REMAIN GENERALLY LIGHT THROUGH THE PERIOD OUTSIDE OF STORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JVM SHORT TERM...SHALLENBERGER LONG TERM...RAY/DJ AVIATION...JVM/HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
804 PM EDT THU JUN 25 2015 .UPDATE... ISSUED AT 640 PM EDT THU JUN 25 2015 STRONG TO SEVERE STORMS HAVE FINALLY STARTED TO DEVELOP ACROSS EASTERN KENTUCKY BUT REMAIN MOSTLY SCATTERED IN NATURE. EXPECT THE COVERAGE TO INCREASE THROUGHOUT THE EVENING HOURS SINCE THE CAP IS NOW BROKEN. DECIDED TO BUMP POPS UP TO INCLUDE AT LEAST A SLIGHT CHANCE POP ACROSS OUR SOUTHERN COUNTIES...AS WELL AS ADJUST T/TD GRIDS TO ALIGN THEM WITH RECENT OBS. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 359 PM EDT THU JUN 25 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE A STATIONARY BOUNDARY DRAPED ACROSS CENTRAL AND EASTERN KENTUCKY. CURRENT VISIBLE SHOT ACROSS THE AREA SHOWS SOME BREAKS IN THE CLOUD COVER ACROSS THE AREA. THIS HAS ALLOWED SOME INCREASED HEATING DESPITE THE CAP AND LACK OF INSTABILITY FROM THIS MORNINGS MCS. IF THE BREAKS AND INCREASED HEATING CONTINUES...SOME CONVECTION MAY BEGIN TO DEVELOP IN THE NEXT COUPLE OF HOURS. THE ISSUE HERE IS IF THE CAP AT 800MB IS BROKEN. THE HRRR HAS BEEN SLIGHTLY LESS STELLAR HINTING AT CONVECTION ALL AFTERNOON BUT TO NO AVAIL. SOME SHOWER ACTIVITY HAS DEVELOPED UPSTREAM IN SOUTHERN IN AND WESTERN KY SO WILL INTRODUCE SOME POPS INTO EASTERN KENTUCKY AFTER 21Z THIS AFTERNOON. HEADING INTO TONIGHT...THE NEXT CLUSTER OF STORMS DEVELOPS AND BEGINS TO TRACK SOUTHEAST INTO KY. THE FORMATION OF THIS AREA SHOULD BEGIN IN CENTRAL KY OR EVEN A BIT FURTHER WEST. IT IS WORTH MENTIONING THAT MODELS HAVE BEEN LESS THAN STELLAR PICKING OUT THIS DEVELOPMENT. THOUGH WITH TRENDS AND COLLABORATION WITH NEIGHBORING OFFICES...WILL BE INTRODUCING LIKELY POPS INTO EASTERN KENTUCKY SHORTLY AFTER 00Z BUT DEVELOPMENT AND A STARTING POINT FOR CONVECTIVE INITIATION IS A BIT OF A TOUGH CALL. TOMORROW...A STRONGER WAVE DIPS SOUTH INTO THE LOWER OH VALLEY CROSSING OVER THE RIDGE OUT WEST AND MAKES FOR AN INTERESTING SITUATION FOR KY ON FRIDAY EVENING AND FRIDAY NIGHT. WITH THIS...THE WARM FRONT WITH A STRONG SOUTHERLY SURGE PUSHES NORTH THROUGH THE AREA. AHEAD OF THIS SHOULD BE STRONG CONVECTION AND POSSIBLY SEVERE THUNDERSTORMS. EARLY MORNING CONVECTION MAY HINDER THIS A BIT BUT THE WARM AND MOIST AIR SURGING FROM THE SOUTH SHOULD MAKE FRIDAY EVENING AND INTO FRIDAY NIGHT QUITE INTERESTING. WILL MENTION THIS PERIOD IN THE HWO AS THIS WILL BEGIN AN ACTIVE PERIOD. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 359 PM EDT THU JUN 25 2015 MODELS APPEAR TO BE IN GOOD AGREEMENT WITH MID AND UPPER LEVEL FLOW THROUGH THE EXTENDED. WE FIND OURSELVES UNDER THE INFLUENCE OF A HIGH AMPLITUDE PATTERN WITH A MEAN EAST CONUS TROUGH AND WEST CONUS RIDGE. AS SUCH WE CAN EXPECT BELOW NORMAL TEMPERATURES THROUGH THE PERIOD AND IN GENERAL AN UNSETTLED WEATHER PATTERN. MODEL GUIDANCE IS IN GOOD AGREEMENT WITH A POSITIVELY TILTED TROUGH CUTTING OFF ACROSS THE GREAT LAKES REGION BY EARLY SATURDAY. THIS FEATURE WILL EVENTUALLY TRACK EAST...BECOMING NEGATIVELY TILTED AS IT MOVES INTO SOUTHERN NEW ENGLAND STATES SUNDAY. ADDITIONAL SHORTWAVE ENERGY DIGS OUT A REINFORCING TROUGH OVER OUR REGION BY MONDAY WHICH ONLY GRADUALLY LIFTS OUT TO THE NORTHEAST BY THE END OF THE FORECAST WINDOW. BY THEN THERE IS A TENDENCY FOR THE PATTERN TO BECOME LESS AMPLIFIED AND A BIT MORE ZONALLY ORIENTED AS WESTERN CONUS RIDGE SHIFTS OUT INTO THE PACIFIC AND ADDITIONAL SHORTWAVE ENERGY DROPS INTO THE UPPER MIDWEST. AT THE SURFACE...THE INITIAL TROUGH/CUT OFF LOW WILL AID IN DEVELOPING A SURFACE LOW ACROSS THE WESTERN OHIO VALLEY AT THE START OF THE PERIOD. THIS RELATIVELY DEEP AND WELL ORGANIZED SFC LOW WILL RIDE UP THE OHIO VALLEY OVER THE WEEKEND...WITH A TRAILING COLD FRONT ADVANCING ACROSS OUR AREA SATURDAY MORNING. ANOTHER FRONTAL SYSTEM WILL SWEEP THROUGH THE REGION AT THE START OF THE WEEK...LATE MONDAY INTO TUESDAY. ONCE AGAIN...THIS PATTERN WILL ENSURE BELOW NORMAL TEMPS THROUGH THE PERIOD WITH HIGHS IN THE MID 70S TO LOWER 80S AND LOWS MAINLY FALLING INTO THE 50S TO LOWER 60S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 804 PM EDT THU JUN 25 2015 SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER THE PAST COUPLE OF HOURS...MAINLY IN AND AROUND THE JKL...SJS...AND SME TAF SITES. EXPECT THESE STORMS TO GRADUALLY WEAKEN WITH THE LOSS OF DAYTIME HEATING. BUT ANTICIPATE CIGS/VIS TO LOWER OVERNIGHT TONIGHT DUE TO LEFTOVER SHOWERS AND FOG DEVELOPMENT...WITH ALTERNATE MIN VIS POSSIBLE AT THE SJS...SME AND LOZ TAF SITES AND MVFR VIS AT THE JKL AND SYM TAF SITES. A LULL IN PRECIP DURING THE MORNING HOURS WILL ALLOW FOR VFR CONDITIONS FOR A TIME ON FRIDAY...BEFORE AFTERNOON THUNDERSTORM ACTIVITY DEVELOPS ONCE AGAIN. WINDS WILL REMAIN GENERALLY LIGHT THROUGH THE PERIOD OUTSIDE OF STORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JVM SHORT TERM...SHALLENBERGER LONG TERM...RAY/DJ AVIATION...JVM/HAL
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
927 PM CDT THU JUN 25 2015 .DISCUSSION... OUTFLOW BOUNDARY HAS PUSHED INTO NORTHEAST TEXAS LATE THIS EVENING BUT CONVECTION HAS NOT BEEN ABLE TO SUSTAIN ITSELF THIS EVENING LIKE THE PREVIOUS TWO EVENINGS. LATEST HRRR IN GOOD AGREEMENT WITH THIS ASSESSMENT SO IT SHOULD BE SAFE TO REMOVE POPS FROM THE FORECAST FOR THE REMAINDER OF THE EVENING. CONCERNING TEMPS... HAVE LOWERED TEMPS A FEW DEGREES ACROSS N LA WHERE EARLIER RAINFALL ALREADY HAD 02Z TEMPS NEAR OR AT FCST MIN TEMPS. DID RAISE TEMPS A DEGREE OR TWO ACROSS NE TX WHERE THE RAINFALL DID NOT MAKE IT...FOLLOWING PERSISTENCE OVER THE LAST SEVERAL MORNINGS IN THIS LOCATION. WE ARE LEFT WITH AN EXPANSIVE CLOUD DEBRIS PATTERN ON IR IMAGERY IN THE WAKE OF THE CONVECTION SO BEEFED UP SKY CONDITIONS FOR THE NEXT 6 HOURS OR SO BUT THE CLOUD COVER SHOULD BEGIN TO THIN AFTER MIDNIGHT. OTHER DEWPOINT/WIND GRIDS CHANGES WERE MOSTLY COSMETIC. UPDATE OUT SHORTLY...13. && .PREV DISCUSSION... /ISSUED 707 PM CDT THU JUN 25 2015/ AVIATION... SCT SHWRS/TSTM STILL ROAMING WESTWARD ON OUTFLOW FROM KSHV VCNTY...DOWN INTO TOLEDO BEND COUNTRY FOR ANOTHER HOUR OR TWO. SFC WINDS LIGHT S AND CLIMB WINDS SE-SW 10-20KTS...VEERING TO NW FLOW BY 12KFT. SKC OVERNIGHT WITH MAYBE A SITE OR TWO WITH DAYBREAK BR. ANOTHER ROUND OF DIURNAL HEATING CONVECTION FOR FRI. W/ A TWIST AS A COLD FRONT EDGES INTO PLAY FOR THE OVERNIGHT AND MUCH OF SAT. SCT/NUMEROUS STORMS EXPECTED...SOME NOCTURNAL. GUSTY WINDS AND TURBULENCE NEAR DOWNPOURS/TOWERS WITH BETTER WX BY SUN. 24 && .PRELIMINARY POINT TEMPS/POPS... SHV 75 93 75 85 / 10 20 60 60 MLU 74 93 75 86 / 10 30 60 60 DEQ 72 92 70 86 / 10 40 60 30 TXK 75 93 72 86 / 10 30 60 40 ELD 73 94 73 84 / 10 40 60 50 TYR 75 92 75 88 / 10 20 50 50 GGG 76 93 75 86 / 10 20 50 50 LFK 76 93 75 89 / 10 30 40 60 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$ 24/13
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
410 PM CDT WED JUN 24 2015 .SYNOPSIS...MOISTURE CONTINUES TO DEEPEN IN RESPONSE TO AN UPPER LOW OVER THE SOUTHWESTERN GULF AND A PERSISTENT RIDGE OF HIGH PRESSURE IN THE LOWER LEVELS OVER THE EASTERN GULF. THIS WILL GIVE THE AREA A DECENT CHANCE FOR SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EVENING ON THURSDAY. && .SHORT RANGE...THE HRRR DEPICTS ANOTHER IMPULSE MOVING THROUGH THE ATCHAFALAYA IN EASTERLY FLOW AND MOVING INTO THE ACADIANA AREA THIS EVENING BRINGING SCATTERED SHOWERS AND THUNDERSTORMS. WENT HIGHER THAN GUIDANCE ON POPS DUE TO THIS FEATURE AS WELL AS HIGH THETA AIR AND AMPLE MOISTURE WITH PRECIP WATER VALUES CONTINUING ABOUT A STANDARD DEVIATION ABOVE CLIMO. && .LONG RANGE...MODELS ARE STILL CONSISTENT ON A DIGGING UPPER LEVEL TROF INTO THE MIDWEST WITH A FAIRLY DEEP LOW FOR THIS TIME OF YEAR SOUTH OF THE GREAT LAKES. THIS WILL DRIVE A WEAK COLD FRONT INTO OUR AREA AND BRING A LIKELY CHANCE FOR SHOWERS AND TSTMS THIS WEEKEND. THE UPPER TROF REMAINS A FEATURE INTO NEXT WEEK OVER THE EASTERN PORTION OF THE U.S. WHICH WILL WEAKEN THE RIDGE OVER OUR AREA AND ALLOW FOR HIGHER THAN NORMAL RAIN CHANCES NEXT WEEK. SWEENEY && .PRELIMINARY POINT TEMPS/POPS... AEX 73 91 77 90 / 30 40 20 30 LCH 75 90 79 88 / 30 40 10 30 LFT 77 92 77 88 / 30 40 10 30 BPT 76 90 78 89 / 30 30 10 30 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ PUBLIC...11
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
831 AM CDT WED JUN 24 2015 ...SOUNDING DISCUSSION... THE SOUNDING THIS MORNING DEPICTS AN ATMOSPHERE THAT IS MOIST AND UNSTABLE. PW IS ABOVE AVERAGE AT 1.96 INCHES AND MIXED LAYER CAPE IS 1000 J/KG... MOST UNSTABLE CAPE IS 2700 J/KG. A SHALLOW TEMPERATURE INVERSION IS AT THE SFC TO 1500 FT AND WILL MIX OUT QUICKLY. WINDS ARE LIGHT AND NORTHEASTERLY FROM THE SFC TO 500 MB THEN BECOME EASTERLY THROUGH THE REST OF THE PROFILE. CONVECTIVE TEMPERATURE ON THE SOUNDING IS LISTED AT 93F AND STORMS ARE EXPECTED TO FIRE WITH DAYTIME HEATING SIMILAR TO THE PAST FEW DAYS. KRAUTMANN && .PREV DISCUSSION... /ISSUED 333 AM CDT WED JUN 24 2015/ SHORT TERM... CURRENTLY MONITORING TRENDS AND EVOLUTION OF CONVECTION OVER ALABAMA AND NORTHERN MISSISSIPPI THIS MORNING AS A RESULT OF A LARGE OUTFLOW BOUNDARY THAT IS MOWING SOUTHWEST THROUGH AN UNSTABLE AIR MASS. THE SOUTHERN ALABAMA ACTIVITY HAS CONGEALED INTO A RATHER LARGE AND EXPANDING MCS WITH PLENTY OF IN-CLOUD LIGHTNING AND ONLY ABOUT 10 PERCENT CLOUD-TO-GROUND PRODUCTION. THE LARGER SCALE MODELS ARE NOT HANDLING THIS DEVELOPMENT PARTICULARLY WELLL BUT THE HIGHER RESOLUTION SHORT-RANGE CONVECTIVE BASED MODELS LIKE THE HRRR AND WRF ARE LATCHED IN ON CURRENT TRENDS. AS A RESULT...HAVE OPTED TO INCREASE RAIN CHANCES TO 50 PERCENT WITH EARLY ONSET ON THE MISSISIPPI COAST...AND EARLIER THAN TYPICAL IN LOUISIANA BY MID-MORNING. HIGH CAPE AND LOW SHEAR ENVIRONMENT WOULD SUGGEST MAIN THREAT TO BE WET MICROBURSTS OVER LAND AREAS AFTER SUNRISE AND TYPE II WATERSPOUT PRODUCTION IN THE COASTAL WATERS AND POSSIBLY OVER AREA BAYS AND INLAND WATERWAYS. RAINFALL CAN ALSO BE EFFICIENT WITH SOME LOCALIZED PONDING POSSIBLE...THOUGH MUCH OF THE RAINFALL WILL BE ANVIL DECAY TYPE AWAY FROM THE PRIMARY CORES. MOVEMENT AND PROPAGATION DUE TO OUTFLOW SHOULD BE ABLE TO KEEP STORM TOTAL RAINFALL AT MANAGEABLE LEVELS TODAY. CONVECTION WILL ALSO LIKELY DISRUPT THE SEA BREEZE CYCLE TODAY...OR AT LEAST GREATLY DELAY THE ONSET UNTIL MUCH LATER IN THE AFTERNOON AS THE AIR MASS WILL NEED TIME TO RECOVER AFTER MORNING CONVECTION AND INDUCTION OF DEEPER NORTHERLY FLOW ALOFT. OTHERWISE...TEMPERATURES OF MODEL CONSENSUS WILL BE PROVIDED BUT MAY BE IN LINE FOR SOME BUSTS OR AT LEAST ATYPICAL DIURNAL TREND BEHAVIORS DUE TO CLOUD COVER EARLY ON. FRIDAY COULD BE A REPEAT AS A COLD POOL REMAINS IN PLACE ALOFT AND NOCTURNAL CONVECTION MAY ONCE AGAIN ERUPT DUE TO OUTFLOW FEATURES GENERATED FROM CONVECTION ALONG THE FRINGES OF UPPER RIDGE FARTHER NORTH. LONG TERM... MODELS ARE STILL IN VERY GOOD AGREEMENT WITH LARGE SCALE TROUGHING TO TAKE PLACE OVER THE WEEKEND. THIS SHOULD ALLOW A SURFACE FRONTAL FEATURE TO SETTLE INTO THE AREA...POSSIBLY DROPPING INTO THE NORTH GULF LATE SUNDAY...AND PROVIDING A GENERALLY COOLING TO AT LEAST NEAR NORMAL TEMPERATURES FOR NEXT WEEK. THE PATTERN WOULD ALSO FAVOR INCREASED CHANCES AT RAINFALL EACH DAY POSSIBLY IN MCS FASHION IN BASE OF TROUGH BY MID-WEEK. CONSENSUS MODEL GUIDANCE ON TEMPERATURES AND POPS DURING THE EXTENDED PORTION. 24/RR AVIATION... EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE TAF PERIOD WITH GENERALLY LIGHT AND VARIABLE WINDS. HOWEVER OVERNIGHT CONVECTION FROM SOUTH CENTRAL ALABAMA CONTINUES TO DRIFT TOWARDS THE FORECAST AREA THIS MORNING AND WILL PROBABLY HAVE TO AMEND TAFS BEFORE THE 12Z ISSUANCE TO ADD THUNDERSTORMS INTO THE KGPT TAF AND TO START CONVECTION EARLIER AT KMCB AND KASD. WILL HAVE TO CONTINUE TO WATCH. GUSTY WINDS AND FREQUENT LIGHTNING WILL BE THE MAIN THREATS. VSBY WITHIN THUNDERSTORMS COULD DROP TO IFR CONDITIONS BUT OUTSIDE OF CONVECTION EXPECT MOSTLY VFR CONDITIONS. 13/MH MARINE... A WEAK SURFACE RIDGE REMAINS ACROSS THE REGION WITH NO MAJOR CHANGES TO THE FORECAST AS WINDS WILL BE GENERALLY 10 KNOTS OR LESS. ISOLATED TO SCATTERED CONVECTION IS POSSIBLE EACH AFTERNOON. THE PATTERN SHOULD BE BROKEN BY AN APPROACHING COLD FRONT ON SATURDAY AS WIND SPEEDS AND SEAS WILL BEGIN TO PICK UP. 13/MH DECISION SUPPORT... DSS CODE...BLUE. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...RIVER FLOOD WARNINGS ON MISSISSIPPI RIVER. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 94 74 91 74 / 50 30 40 20 BTR 95 76 92 75 / 50 30 40 10 ASD 94 77 91 77 / 50 20 40 20 MSY 94 78 91 77 / 50 20 40 20 GPT 93 79 91 78 / 50 30 40 20 PQL 93 77 91 78 / 50 30 30 20 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
333 AM CDT WED JUN 24 2015 .SHORT TERM... CURRENTLY MONITORING TRENDS AND EVOLUTION OF CONVECTION OVER ALABAMA AND NORTHERN MISSISSIPPI THIS MORNING AS A RESULT OF A LARGE OUTFLOW BOUNDARY THAT IS MOWING SOUTHWEST THROUGH AN UNSTABLE AIR MASS. THE SOUTHERN ALABAMA ACTIVITY HAS CONGEALED INTO A RATHER LARGE AND EXPANDING MCS WITH PLENTY OF IN-CLOUD LIGHTNING AND ONLY ABOUT 10 PERCENT CLOUD-TO-GROUND PRODUCTION. THE LARGER SCALE MODELS ARE NOT HANDLING THIS DEVELOPMENT PARTICULARLY WELLL BUT THE HIGHER RESOLUTION SHORT-RANGE CONVECTIVE BASED MODELS LIKE THE HRRR AND WRF ARE LATCHED IN ON CURRENT TRENDS. AS A RESULT...HAVE OPTED TO INCREASE RAIN CHANCES TO 50 PERCENT WITH EARLY ONSET ON THE MISSISIPPI COAST...AND EARLIER THAN TYPICAL IN LOUISIANA BY MID-MORNING. HIGH CAPE AND LOW SHEAR ENVIRONMENT WOULD SUGGEST MAIN THREAT TO BE WET MICROBURSTS OVER LAND AREAS AFTER SUNRISE AND TYPE II WATERSPOUT PRODUCTION IN THE COASTAL WATERS AND POSSIBLY OVER AREA BAYS AND INLAND WATERWAYS. RAINFALL CAN ALSO BE EFFICIENT WITH SOME LOCALIZED PONDING POSSIBLE...THOUGH MUCH OF THE RAINFALL WILL BE ANVIL DECAY TYPE AWAY FROM THE PRIMARY CORES. MOVEMENT AND PROPAGATION DUE TO OUTFLOW SHOULD BE ABLE TO KEEP STORM TOTAL RAINFALL AT MANAGEABLE LEVELS TODAY. CONVECTION WILL ALSO LIKELY DISRUPT THE SEA BREEZE CYCLE TODAY...OR AT LEAST GREATLY DELAY THE ONSET UNTIL MUCH LATER IN THE AFTERNOON AS THE AIR MASS WILL NEED TIME TO RECOVER AFTER MORNING CONVECTION AND INDUCTION OF DEEPER NORTHERLY FLOW ALOFT. OTHERWISE...TEMPERATURES OF MODEL CONSENSUS WILL BE PROVIDED BUT MAY BE IN LINE FOR SOME BUSTS OR AT LEAST ATYPICAL DIURNAL TREND BEHAVIORS DUE TO CLOUD COVER EARLY ON. FRIDAY COULD BE A REPEAT AS A COLD POOL REMAINS IN PLACE ALOFT AND NOCTURNAL CONVECTION MAY ONCE AGAIN ERUPT DUE TO OUTFLOW FEATURES GENERATED FROM CONVECTION ALONG THE FRINGES OF UPPER RIDGE FARTHER NORTH. .LONG TERM... MODELS ARE STILL IN VERY GOOD AGREEMENT WITH LARGE SCALE TROUGHING TO TAKE PLACE OVER THE WEEKEND. THIS SHOULD ALLOW A SURFACE FRONTAL FEATURE TO SETTLE INTO THE AREA...POSSIBLY DROPPING INTO THE NORTH GULF LATE SUNDAY...AND PROVIDING A GENERALLY COOLING TO AT LEAST NEAR NORMAL TEMPERATURES FOR NEXT WEEK. THE PATTERN WOULD ALSO FAVOR INCREASED CHANCES AT RAINFALL EACH DAY POSSIBLY IN MCS FASHION IN BASE OF TROUGH BY MID-WEEK. CONSENSUS MODEL GUIDANCE ON TEMPERATURES AND POPS DURING THE EXTENDED PORTION. 24/RR && .AVIATION... EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE TAF PERIOD WITH GENERALLY LIGHT AND VARIABLE WINDS. HOWEVER OVERNIGHT CONVECTION FROM SOUTH CENTRAL ALABAMA CONTINUES TO DRIFT TOWARDS THE FORECAST AREA THIS MORNING AND WILL PROBABLY HAVE TO AMEND TAFS BEFORE THE 12Z ISSUANCE TO ADD THUNDERSTORMS INTO THE KGPT TAF AND TO START CONVECTION EARLIER AT KMCB AND KASD. WILL HAVE TO CONTINUE TO WATCH. GUSTY WINDS AND FREQUENT LIGHTNING WILL BE THE MAIN THREATS. VSBY WITHIN THUNDERSTORMS COULD DROP TO IFR CONDITIONS BUT OUTSIDE OF CONVECTION EXPECT MOSTLY VFR CONDITIONS. 13/MH && .MARINE... A WEAK SURFACE RIDGE REMAINS ACROSS THE REGION WITH NO MAJOR CHANGES TO THE FORECAST AS WINDS WILL BE GENERALLY 10 KNOTS OR LESS. ISOLATED TO SCATTERED CONVECTION IS POSSIBLE EACH AFTERNOON. THE PATTERN SHOULD BE BROKEN BY AN APPROACHING COLD FRONT ON SATURDAY AS WIND SPEEDS AND SEAS WILL BEGIN TO PICK UP. 13/MH && .DECISION SUPPORT... DSS CODE...BLUE. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...RIVER FLOOD WARNINGS ON MISSISSIPPI RIVER. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 94 74 91 74 / 50 30 40 20 BTR 95 76 92 75 / 50 30 40 10 ASD 94 77 91 77 / 50 20 40 20 MSY 94 78 91 77 / 50 20 40 20 GPT 93 79 91 78 / 50 30 40 20 PQL 93 77 91 78 / 50 30 30 20 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$ 24/RR 13/MH
AREA FORECAST DISCUSSION
NWS GAYLORD MI
905 PM EDT THU JUN 25 2015 .UPDATE... ISSUED AT 905 PM EDT THU JUN 25 2015 BROAD HIGH PRESSURE REMAINS DRAPED ACROSS THE NRN GREAT LAKES REGION WITH GENERALLY LIGHT EASTERLY FLOW ACROSS NRN MICHIGAN ALTHOUGH LAKE BREEZES AND OUTFLOW BOUNDARIES HAVE DOMINATING THE SCENE TODAY. SATELLITE/WATER VAPOR IMAGERY CLEARLY SHOWS A SHORT WAVE SAGGING DOWN INTO NRN MICHIGAN AND A DEFINITIVE PUSH OF SOME DRIER AIR HEADING DOWN INTO NRN MICHIGAN BEHIND THE WAVE. WITH THE LIGHT FLOW/HEATING AND SOME INSTABILITY/WEAK QG- FORCING...WE GOT OUR INLAND CONVECTION TODAY...SOME OF WHICH CONTINUES TO PERCOLATE AT THIS HOUR. REST OF TONIGHT...ONGOING INLAND CONVECTION WILL CONTINUE TO PERCOLATE ABOUT FOR A FEW MORE HOURS UNTIL REMAINING INSTABILITY FADES. HAVE STRETCHED INLAND POPS INTO THE OVERNIGHT HOURS TO COVER IT...ALTHOUGH I/VE SEEN THIS SORT OF STUFF LAST WELL INTO THE NIGHT. OTHERWISE...DRIER AIR WILL EVENTUALLY SAG DOWN THROUGH NRN LOWER MICHIGAN SUPPRESSING MUCH OF THIS MID AND HIGH CLOUD COVER INTO THE LOWER LAKES DURING THE OVERNIGHT LEADING TO DECREASING CLOUD TREND FOR ALL AREAS. SOME FOG IS POSSIBLE PARTICULARLY FOR AREAS THAT HAVE HAD RAIN IN THE LAST FEW HOURS. && .NEAR TERM...(THIS EVENING THROUGH TONIGHT) ISSUED AT 309 PM EDT THU JUN 25 2015 THE STORM SYSTEM WHICH MOVED INTO THE OHIO VALLEY AND SRN GREAT LAKES EARLIER...WILL PUSH EAST TOWARD THE MID ATLANTIC TONIGHT WHILE A LARGE AREA OF HIGH PRESSURE BEGINS TO SETTLE INTO THE NORTHERN GREAT LAKES. AT UPPER LVLS...A 500MB TROUGH CURRENTLY DROPPING SOUTHWARD ACROSS THE STATE...WILL WEAKEN AND MOVE EAST OF THE REGION AFTER 06Z. THE OVERALL TREND OVERNIGHT INTO EARLY FRIDAY WILL BE CLEARING SKIES WITH DIMINISHING PCPN. MODEL SOUNDINGS AND MSTR PROGS SHOWING SUFFICIENT MSTR IN PLACE ACRS THE GREAT LAKES TO CONTINUE PCPN THROUGH THE EVENING HOURS. 850MB DEW PTS WILL BE BETWEEN 9C AND 11C...SFC DEW PTS WILL LINGER IN THE MID AND UPPER 50S WHILE MODEL SOUNDINGS SHOW PWAT VALUES NEAR 1.20 INCHES. FORCING THIS EVENING WILL BE FROM A COMBINED EFFORT OF LAKE BREEZE BOUNDARIES AND UPPER LVL CONVERGENCE. 500-300MB QVECTORS SHOW FORCING (ASSOCIATED WITH THE 500MB TROUGH)...CENTERED OVER NORTHERN MICHIGAN THIS EVENING BEFORE SHIFTING EAST BY 06Z. CURRENT SFC OBS SHOWING SOME LAKE BREEZE DEVELOPMENT THIS AFTN IN WEAK SYNOPTIC WIND FLOW AND AFTN TEMPS IN THE MID 70S. THE LAKE BREEZE FORMATION HAS HELPED CONCENTRATE MOST OF THE PCPN THIS AFTN TO INTERIOR PORTIONS OF NRN LWR MI. A THUNDERSTORM IS ALSO POSSIBLE THIS EVENING...AS MODEL SOUNDINGS AND HRRR DATA SHOW CAPE VALUES NEARING 1200 J/KG (AWAY FROM THE GREAT LAKES). CAPES VALUES DIMINISH QUICKLY TO UNDER 500 J/KG ARND 03Z...AS DRIER AIR BEGINS TO FILTER INTO NRN MI. MODEL SOUNDINGS AND MSTR PROGS SHOW MUCH DRIER AIRMASS TO DEVELOP OVER THE NRN GREAT LAKES AFTER 03Z...THE RESULT OF A LARGE AREA OF CANADIAN HIGH PRESSURE SETTLING FURTHER SOUTH INTO MI. 850/500MB RH FALLS FROM 80 PCT TO UNDER 40 PCT...PWAT VALUES FALL FROM 1.20IN TO 0.50IN AND 850MB DEW PTS DRY FROM ARND 12C TO ARND 4C. OVERALL WILL CONTINUE CURRENT FORECAST TREND OF SCATTERED SHOWERS AND A FEW THUNDERSTORMS THIS EVENING...ENDING AROUND MIDNIGHT FOR MOST LOCATIONS. WILL MENTION SOME PATCHY FOG OVERNIGHT AS TEMPS FALL THROUGH THE 50S WHILE SFC DEW PTS SLOWLY DROP INTO THE LOWER 50S. && .SHORT TERM...(FRIDAY THROUGH SUNDAY) ISSUED AT 309 PM EDT THU JUN 25 2015 ZONAL FLOW BECOMING MORE AMPLIFIED OVER THE NEXT SEVERAL DAYS AS QUASI-PERMANENT WESTERN CONUS RIDGE BUILDS WITH DOWNSTREAM TROUGHING ACROSS THE EASTERN STATES. ALTHOUGH AIRMASS IS BECOMING DRIER ON FRIDAY...STILL A HINT OF SOME HIGHER LOW LEVEL MOISTURE/H9-H8 THETA-E RIDGING UP THE US-131 AND I-75 CORRIDORS IN NORTHERN LOWER AND OVER PARTS OF EASTERN UPPER. THIS MOISTURE COMBINED WITH SOME LAKE BREEZE CONVERGENCE...CAN/T RULE OUT AN ISOLATED AFTERNOON SHOWER AND WILL ADD THIS TO THE FORECAST. OTHERWISE...A TERRIFIC STRETCH OF SUMMER WEATHER FOR THE WEEKEND. WILL STILL HAVE TO KEEP AN EYE ON THE UPPER LOW CLOSING OFF OVER THE NORTHERN OHIO VALLEY ON SATURDAY AND PUSHING NORTH/NORTHEAST INTO THE WESTERN LAKES. MODEL CONSENSUS STILL KEEPS THIS SYSTEM JUST SOUTH/EAST OF OUR AREA...WHICH SEEMS PLAUSIBLE GIVEN THE LACK OF DOWNSTREAM BLOCKING. BUT IT WILL BE VERY CLOSE FOR AREAS NEAR SAGINAW BAY AND SOMETHING THAT COULD RESULT IN A FEW SHOWERS CREEPING NORTHWARD TOWARD GLADWIN/ARENAC/IOSCO COUNTIES LATER SATURDAY INTO SATURDAY NIGHT. NORTHERN MICHIGAN WILL BE BETWEEN SYSTEMS ON SUNDAY...WITH UPPER LOW TO THE EAST AND NEXT UPSTREAM SHORTWAVE DIVING THROUGH THE UPPER MIDWEST. THE END RESULT SHOULD BE A FAIRLY NICE DAY WITH POSSIBLY A FEW MORE CLOUDS BUT COMFORTABLE TEMPERATURES/DRY CONDITIONS. && .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 309 PM EDT THU JUN 25 2015 RIDGING OVER THE WESTERN THIRD OF THE CONUS WILL LEAD TO TROUGHING OVER THE EASTERN TWO-THIRDS THROUGH MUCH...IF NOT ALL OF THE EXTENDED PERIOD. THIS WILL LEAD TO SLIGHTLY COOLER THAN NORMAL TEMPERATURES AND INCREASED CHANCES FOR SCATTERED RAIN SHOWERS AND PERHAPS A FEW THUNDERSTORMS FROM SUNDAY NIGHT THROUGH AT LEAST TUESDAY NIGHT (ALTHOUGH RECENT TRENDS HAVE INDICATED LIMITED MOISTURE ACROSS NORTHERN MICHIGAN THROUGH THE MONDAY-TUESDAY TIMEFRAME...SO BY ALL MEANS NEITHER DAY LOOKS LIKE A WASHOUT). TOWARD THE VERY END OF THE PERIOD...LONG-RANGE GLOBAL MODEL GUIDANCE SUGGESTS A MORE MOISTURE-RICH SYSTEM TO APPROACH THE MIDWEST/GREAT LAKES...PERHAPS PROVIDING A BETTER CHANCE AT WIDESPREAD RAIN ACROSS THE REGION. LOTS OF TIME TO IRON OF THE DETAILS ON IF/WHEN THAT`S EXPECTED TO OCCUR. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 731 PM EDT THU JUN 25 2015 VFR CONDITIONS PERSIST ACROSS NRN LOWER MICHIGAN ALTHOUGH BKN-OVC MID CLOUD WILL LINGER THROUGH THE EVENING HOURS BEFORE THINNING OUT OVERNIGHT. SPOTTY HEATING OF THE DAY SHOWERS ARE OUT THERE AS WELL BUT LARGELY IMPACTING INTERIOR NRN LOWER MICHIGAN. AS CLOUD COVER THINS LATER TONIGHT...THERE IS A RISK FOR SOME FOG DEVELOPMENT PARTICULARLY AT PLN AND APN...WITH MVFR CONDITIONS AND RISK FOR IFR VSBYS OVERNIGHT. WINDS GO NEARLY CALM BY LATER THIS EVENING...INCREASE AGAIN ON FRIDAY BUT REMAIN UNDER 10 KNOTS FOR THE MOST PART. LAKE BREEZE WIND DIRECTIONS WILL AGAIN DOMINATE THE TERMINAL SITES BY AFTERNOON. && .MARINE... ISSUED AT 309 PM EDT THU JUN 25 2015 WINDS AND WAVES ARE TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH THE FORECAST PERIOD...AS A LARGE AREA OF CANADIAN HIGH PRESSURE SINKS SOUTH OVER THE GREAT LAKES. MAINLY DRY CONDS CAN BE EXPECTED IN THE NEARSHORE AREAS THROUGH THE FORECAST PERIOD. HOWEVER SCATTERED SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE THIS EVENING AS AN UPPER TROUGH EXITS THE STATE. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...ADAM NEAR TERM...SWR SHORT TERM...KEYSOR LONG TERM...GILLEN AVIATION...ADAM MARINE...SWR
AREA FORECAST DISCUSSION
NWS GAYLORD MI
731 PM EDT THU JUN 25 2015 .NEAR TERM...(THIS EVENING THROUGH TONIGHT) ISSUED AT 309 PM EDT THU JUN 25 2015 THE STORM SYSTEM WHICH MOVED INTO THE OHIO VALLEY AND SRN GREAT LAKES EARLIER...WILL PUSH EAST TOWARD THE MID ATLANTIC TONIGHT WHILE A LARGE AREA OF HIGH PRESSURE BEGINS TO SETTLE INTO THE NORTHERN GREAT LAKES. AT UPPER LVLS...A 500MB TROUGH CURRENTLY DROPPING SOUTHWARD ACROSS THE STATE...WILL WEAKEN AND MOVE EAST OF THE REGION AFTER 06Z. THE OVERALL TREND OVERNIGHT INTO EARLY FRIDAY WILL BE CLEARING SKIES WITH DIMINISHING PCPN. MODEL SOUNDINGS AND MSTR PROGS SHOWING SUFFICIENT MSTR IN PLACE ACRS THE GREAT LAKES TO CONTINUE PCPN THROUGH THE EVENING HOURS. 850MB DEW PTS WILL BE BETWEEN 9C AND 11C...SFC DEW PTS WILL LINGER IN THE MID AND UPPER 50S WHILE MODEL SOUNDINGS SHOW PWAT VALUES NEAR 1.20 INCHES. FORCING THIS EVENING WILL BE FROM A COMBINED EFFORT OF LAKE BREEZE BOUNDARIES AND UPPER LVL CONVERGENCE. 500-300MB QVECTORS SHOW FORCING (ASSOCIATED WITH THE 500MB TROUGH)...CENTERED OVER NORTHERN MICHIGAN THIS EVENING BEFORE SHIFTING EAST BY 06Z. CURRENT SFC OBS SHOWING SOME LAKE BREEZE DEVELOPMENT THIS AFTN IN WEAK SYNOPTIC WIND FLOW AND AFTN TEMPS IN THE MID 70S. THE LAKE BREEZE FORMATION HAS HELPED CONCENTRATE MOST OF THE PCPN THIS AFTN TO INTERIOR PORTIONS OF NRN LWR MI. A THUNDERSTORM IS ALSO POSSIBLE THIS EVENING...AS MODEL SOUNDINGS AND HRRR DATA SHOW CAPE VALUES NEARING 1200 J/KG (AWAY FROM THE GREAT LAKES). CAPES VALUES DIMINISH QUICKLY TO UNDER 500 J/KG ARND 03Z...AS DRIER AIR BEGINS TO FILTER INTO NRN MI. MODEL SOUNDINGS AND MSTR PROGS SHOW MUCH DRIER AIRMASS TO DEVELOP OVER THE NRN GREAT LAKES AFTER 03Z...THE RESULT OF A LARGE AREA OF CANADIAN HIGH PRESSURE SETTLING FURTHER SOUTH INTO MI. 850/500MB RH FALLS FROM 80 PCT TO UNDER 40 PCT...PWAT VALUES FALL FROM 1.20IN TO 0.50IN AND 850MB DEW PTS DRY FROM ARND 12C TO ARND 4C. OVERALL WILL CONTINUE CURRENT FORECAST TREND OF SCATTERED SHOWERS AND A FEW THUNDERSTORMS THIS EVENING...ENDING AROUND MIDNIGHT FOR MOST LOCATIONS. WILL MENTION SOME PATCHY FOG OVERNIGHT AS TEMPS FALL THROUGH THE 50S WHILE SFC DEW PTS SLOWLY DROP INTO THE LOWER 50S. && .SHORT TERM...(FRIDAY THROUGH SUNDAY) ISSUED AT 309 PM EDT THU JUN 25 2015 ZONAL FLOW BECOMING MORE AMPLIFIED OVER THE NEXT SEVERAL DAYS AS QUASI-PERMANENT WESTERN CONUS RIDGE BUILDS WITH DOWNSTREAM TROUGHING ACROSS THE EASTERN STATES. ALTHOUGH AIRMASS IS BECOMING DRIER ON FRIDAY...STILL A HINT OF SOME HIGHER LOW LEVEL MOISTURE/H9-H8 THETA-E RIDGING UP THE US-131 AND I-75 CORRIDORS IN NORTHERN LOWER AND OVER PARTS OF EASTERN UPPER. THIS MOISTURE COMBINED WITH SOME LAKE BREEZE CONVERGENCE...CAN/T RULE OUT AN ISOLATED AFTERNOON SHOWER AND WILL ADD THIS TO THE FORECAST. OTHERWISE...A TERRIFIC STRETCH OF SUMMER WEATHER FOR THE WEEKEND. WILL STILL HAVE TO KEEP AN EYE ON THE UPPER LOW CLOSING OFF OVER THE NORTHERN OHIO VALLEY ON SATURDAY AND PUSHING NORTH/NORTHEAST INTO THE WESTERN LAKES. MODEL CONSENSUS STILL KEEPS THIS SYSTEM JUST SOUTH/EAST OF OUR AREA...WHICH SEEMS PLAUSIBLE GIVEN THE LACK OF DOWNSTREAM BLOCKING. BUT IT WILL BE VERY CLOSE FOR AREAS NEAR SAGINAW BAY AND SOMETHING THAT COULD RESULT IN A FEW SHOWERS CREEPING NORTHWARD TOWARD GLADWIN/ARENAC/IOSCO COUNTIES LATER SATURDAY INTO SATURDAY NIGHT. NORTHERN MICHIGAN WILL BE BETWEEN SYSTEMS ON SUNDAY...WITH UPPER LOW TO THE EAST AND NEXT UPSTREAM SHORTWAVE DIVING THROUGH THE UPPER MIDWEST. THE END RESULT SHOULD BE A FAIRLY NICE DAY WITH POSSIBLY A FEW MORE CLOUDS BUT COMFORTABLE TEMPERATURES/DRY CONDITIONS. && .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 309 PM EDT THU JUN 25 2015 RIDGING OVER THE WESTERN THIRD OF THE CONUS WILL LEAD TO TROUGHING OVER THE EASTERN TWO-THIRDS THROUGH MUCH...IF NOT ALL OF THE EXTENDED PERIOD. THIS WILL LEAD TO SLIGHTLY COOLER THAN NORMAL TEMPERATURES AND INCREASED CHANCES FOR SCATTERED RAIN SHOWERS AND PERHAPS A FEW THUNDERSTORMS FROM SUNDAY NIGHT THROUGH AT LEAST TUESDAY NIGHT (ALTHOUGH RECENT TRENDS HAVE INDICATED LIMITED MOISTURE ACROSS NORTHERN MICHIGAN THROUGH THE MONDAY-TUESDAY TIMEFRAME...SO BY ALL MEANS NEITHER DAY LOOKS LIKE A WASHOUT). TOWARD THE VERY END OF THE PERIOD...LONG-RANGE GLOBAL MODEL GUIDANCE SUGGESTS A MORE MOISTURE-RICH SYSTEM TO APPROACH THE MIDWEST/GREAT LAKES...PERHAPS PROVIDING A BETTER CHANCE AT WIDESPREAD RAIN ACROSS THE REGION. LOTS OF TIME TO IRON OF THE DETAILS ON IF/WHEN THAT`S EXPECTED TO OCCUR. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 731 PM EDT THU JUN 25 2015 VFR CONDITIONS PERSIST ACROSS NRN LOWER MICHIGAN ALTHOUGH BKN-OVC MID CLOUD WILL LINGER THROUGH THE EVENING HOURS BEFORE THINNING OUT OVERNIGHT. SPOTTY HEATING OF THE DAY SHOWERS ARE OUT THERE AS WELL BUT LARGELY IMPACTING INTERIOR NRN LOWER MICHIGAN. AS CLOUD COVER THINS LATER TONIGHT...THERE IS A RISK FOR SOME FOG DEVELOPMENT PARTICULARLY AT PLN AND APN...WITH MVFR CONDITIONS AND RISK FOR IFR VSBYS OVERNIGHT. WINDS GO NEARLY CALM BY LATER THIS EVENING...INCREASE AGAIN ON FRIDAY BUT REMAIN UNDER 10 KNOTS FOR THE MOST PART. LAKE BREEZE WIND DIRECTIONS WILL AGAIN DOMINATE THE TERMINAL SITES BY AFTERNOON. && .MARINE... ISSUED AT 309 PM EDT THU JUN 25 2015 WINDS AND WAVES ARE TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH THE FORECAST PERIOD...AS A LARGE AREA OF CANADIAN HIGH PRESSURE SINKS SOUTH OVER THE GREAT LAKES. MAINLY DRY CONDS CAN BE EXPECTED IN THE NEARSHORE AREAS THROUGH THE FORECAST PERIOD. HOWEVER SCATTERED SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE THIS EVENING AS AN UPPER TROUGH EXITS THE STATE. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ NEAR TERM...SWR SHORT TERM...KEYSOR LONG TERM...GILLEN AVIATION...ADAM MARINE...SWR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
353 PM EDT WED JUN 24 2015 .UPDATE... ISSUED AT 1120 AM EDT WED JUN 24 2015 ONLY MINOR TWEAKS TO THE GOING FORECAST WITH THIS MORNINGS UPDATE. A SHORTWAVE MOVING THROUGH NORTHERN MINNESOTA HAS SPREAD SOME SHOWERS AND A FEW THUNDERSTORMS EAST-SOUTHEAST INTO WESTERN LAKE SUPERIOR...BETWEEN THE APOSTLE ISLANDS AND ISLE ROYALE. EXPECT THIS WAVE TO CONTINUE TO THE EAST AND SPREAD SHOWERS ACROSS THE NORTHERN HALF OF THE KEWEENAW PENINSULA EARLY THIS AFTERNOON. THE QUESTION FOR THIS AFTERNOON WILL BE THE AMOUNT OF SHOWER DEVELOPMENT THAT WILL OCCUR OVER THE LAND AREAS...WHICH WILL BE AIDED BY LAKE BREEZES. SURFACE DEWPOINTS AT THE 11AM WERE IN THE MID-UPPER 50S...BUT THE 12Z KGRB SOUNDING AND RAP ANALYSIS SOUNDINGS SHOW A DECENT POCKET OF DRY AIR JUST ABOVE THE SURFACE AND THROUGH 800MB/7KFT. EXPECT THE SUN THAT IS OCCURRING OVER THE AREA TO AID MIXING OF THAT DRIER AIR TO THE SURFACE OVER THE NEXT COUPLE OF HOURS...WHICH WILL LIMIT THE INSTABILITY OVER THE AREA (DEWPOINTS FALLING INTO THE LOWER 50S AND PROBABLY UPPER 40S TOWARDS THE WISCONSIN BORDER). WHILE THERE WILL BE ENOUGH MOISTURE ABOVE THAT DRY AIR TO DEVELOP CLOUDS AND LIKELY SOME SHOWERS...CONFIDENCE IS LOWER ON WIDESPREAD SHOWERS AND HEAVIER RAIN. MODIFIED SOUNDINGS TO EXPECTED AFTERNOON T/TD VALUES CONTINUES TO SHOW 500-600J/KG OF MLCAPE...SO THUNDER REMAINS POSSIBLE ALONG WITH BRIEF GUSTY WINDS DUE TO ABUNDANT LOW LEVEL DRY AIR PUSHING DCAPE VALUES OVER 800- 900J/KG OVER AT LEAST THE SOUTHERN HALF OF THE CWA. OVERALL EXPECT THE GREATEST FOCUS OF SHOWERS TO BE OVER THE INTERIOR CENTRAL CWA WHEN THEY DEVELOP AROUND MID AFTERNOON AND THEN MOVE TO THE SOUTHEAST AROUND 20-25KTS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 411 AM EDT WED JUN 24 2015 A COLD FRONT AND A SUBTLE UPPER SHORTWAVE WILL MOVE THROUGH TODAY. THESE FEATURES AND LAKE BREEZE FORMATION WILL PROVIDE FORCING FOR CONVECTION MAINLY INLAND FROM THE GREAT LAKES. SBCAPE VALUES SHOULD BE IN THE 500-800J/KG RANGE INLAND...WITH RELATIVELY WEAK SHEAR DUE TO NEARLY CALM WINDS AT AND BELOW 800MB. INVERTED V SOUNDINGS WITH DRY LOW LEVELS AND EVEN AN INDICATION OF AN EML MAY LEAD TO SOME GUSTY WINDS UNDER ANY COLLAPSING STORMS...BUT SEVERE IS NOT EXPECTED AS BEST CONVECTION SHOULD BE WHERE LOW LEVEL MOISTURE IS GREATER...AWAY FROM THE WI BORDER. CONVECTION IS STILL EXPECTED ALONG THE WI BORDER...JUST TO A LESSER EXTENT. NOT SURE ON EXACTLY HOW THINGS PLAY OUT TONIGHT AS A SHORTWAVE CURRENTLY NEAR THE MT/ALBERTA BORDER MOVES INTO OR NEAR THE CWA WHILE A SFC TROUGH MOVES THROUGH. THE NAM...GFS...GEM AND ECMWF HAVE PRECIP MOVING ALONG WITH THESE FEATURES THROUGH THE CWA...BUT A COUPLE OF HIGH-RES MODELS DO NOT SHOW NEARLY THE EXTENT OF PRECIP. AT THIS TIME...SIDED WITH THE MAJORITY OF MODELS AND HAVE HIGH CHANCE TO LIKELY POPS...BUT IS IS ENTIRELY POSSIBLE THAT SOME LOCATIONS WILL STAY DRY TONIGHT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 426 AM EDT WED JUN 24 2015 SEVERAL PERIODS OF LIGHT SHOWERS ARE EXPECTED ACROSS UPPER MICHIGAN DURING THE LONG TERM PERIOD...FIRST WITH LINGERING SHOWERS ON THURSDAY FROM A PASSING SHORTWAVE...AND AGAIN DURING THE LATER PART OF THE WEEKEND AND INTO EARLY NEXT WEEK. THURSDAY...PASSING SHORTWAVE IN A NW FLOW COULD ALLOW SOME ISOLD TO SCT SHOWERS TO LINGER DURING THE MORNING INTO EARLY AFTERNOON HOURS AS MODELS GENERALLY SHOW 200-400 J/KG MLCAPE FOR INSTABILITY OVER INLAND LOCATIONS. OTHERWISE...CONFLUENT FLOW ALOFT AHEAD OF BUILDING RIDGE AND ASSOC MID-LVL Q-VECT DIV/SUBSIDENCE SHOULD GENERALLY LEAD TO DRYING CONDITIONS ESPECIALLY BY LATE AFTERNOON. TEMPORARY SPLIT-FLOW PATTERN DEVELOPING WILL ALLOW AN AREA OF SFC HIGH PRESSURE TO DROP SOUTHEAST ACROSS THE UPPER GREAT LAKES REGION THU NIGHT AND PERSIST INTO SATURDAY RESULTING IN MAINLY DRY CONDITIONS. 00Z NAM HINTS AT A FEW DIURNAL SHOWERS DEVELOPING ON FRIDAY ALONG THE LAKE BREEZES BUT FOR NOW WL MAINTAIN DRY FCST AS MID-LVLS WILL LIKELY BE TOO DRY FOR SHRA DEVELOPMENT. OTHERWISE SHOULD SEE PARTLY CLOUDY TO MOSTLY CLEAR SKIES OVER THE AREA. AMPLIFICATION OF UPSTREAM RIDGE OVER THE WRN CONUS ALONG WITH A SERIES OF WAVES DIVING SOUTH THROUGH THE NRN AND CENTRAL PLAINS LATE THIS WEEK WILL HELP AMPLIFY THE UPPER TROUGH OVER THE EASTERN HALF OF THE CONUS FOR THIS WEEKEND. WHILE THE TROUGH WILL WEAKEN AND SHIFT EAST INTO EARLY NEXT WEEK...A SERIES OF SHORTWAVES DROPPING SOUTHEAST INTO THE GREAT LAKES REGION SUNDAY INTO TUESDAY WILL REINFORCE THE UPPER TROUGH OVER THE GREAT LAKES REGION FOR NEXT WEEK. THIS WILL YIELD NORMAL TO BELOW NORMAL TEMPERATURES ALONG WITH PERIODS OF RAIN SHOWERS AND MAYBE EVEN A FEW THUNDERSTORMS. ALSO SOMETHING TO WATCH...THE LATEST 00Z RUN OF THE ECMWF SHOWS 850 MB TEMPS PLUMMETING TO AROUND 1C BY NEXT TUE EVENING (THE LAST DAY OF JUNE)...BRRR! THIS 00Z SOLUTION IS DEFINITELY MORE AMPLIFIED WITH THE MID-UPR TROUGH INTO THE UPPER GREAT LAKES THAN EITHER THE 00Z GFS OR THE PREVIOUS 12Z ECMWF SOLN...ALLOWING A DIRECT PATH FOR ARCTIC AIR TO DIVE SOUTH INTO THE REGION. AGAIN THIS IS JUST ONE MODEL RUN...BUT IT WILL BE SOMETHING TO MONITOR OVER THE NEXT SEVERAL MODEL RUNS AS A TREND TOWARD THIS MORE AMPLIFIED AND COLDER SOLUTION COULD RESULT IN A BRIEF SPELL OF WELL BELOW NORMAL TEMPS FOR THE MIDDLE OF NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 152 PM EDT WED JUN 24 2015 DIURNAL HEATING HAS LED TO THE DEVELOPMENT OF CLOUDS AND SHOWERS OVER THE INTERIOR PORTIONS OF UPPER MICHIGAN...WHILE A WEAK UPPER LEVEL DISTURBANCE MOVING EAST ACROSS THE NORTHERN HALF OF LAKE SUPERIOR IS PRODUCING SHOWERS THERE TOO. EXPECT THE SHOWERS THAT ARE AFFECTING KCMX TO PUSH EAST AND DIMINISH OVER THE NEXT FEW HOURS. MEANWHILE...THE SHOWERS DEVELOPING OVER THE INTERIOR WEST/CENTRAL U.P. WILL CONTINUE TO EXPAND IN COVERAGE AND AFFECT KIWD/KSAW A LITTLE LATER THIS AFTERNOON. THERE IS ENOUGH INSTABILITY FOR SOME RUMBLES OF THUNDER...BUT DIDN/T FEEL CONFIDENT ENOUGH TO INCLUDE AT KSAW/KIWD AND WILL AMEND AS NECESSARY IF THEY DEVELOP. FOR TONIGHT...ANOTHER DISTURBANCE WILL MOVE THROUGH THE AREA AND IT SHOULD LEAD TO SHOWERS AT ALL THREE SITES. DEPENDING ON THE RAIN...COULD SEE SOME PATCHY GROUND FOG DEVELOP AND HAVE INCLUDED A BRIEF MVFR VSBY FOR KSAW DUE TO THAT. THAT DISTURBANCE WILL SHIFT EAST OF THE AREA THROUGH THE DAY TOMORROW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 352 PM EDT WED JUN 24 2015 THERE WAS SOME LOW CLOUDS AND FOG OVER PORTIONS OF LAKE SUPERIOR THIS MORNING. SOME OF THAT HAS DISSIPATED AND THE NORTHERN PORTIONS HAVE BEEN COVERED BY CLOUDS. THUS...HAVE LIMITED CONFIDENCE ON COVERAGE AND THICKNESS. HIGH PRESSURE DROPPING SOUTH OVER LAKE SUPERIOR TONIGHT WILL LEAD TO WINDS STAYING BELOW 20KTS THROUGH AT LEAST SATURDAY. THEN A SERIES OF WEAK TROUGHS WILL DROP SOUTHEAST ACROSS LAKE SUPERIOR SUNDAY INTO EARLY NEXT WEEK...BUT WINDS ARE STILL EXPECTED TO STAY BELOW 20KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...SRF SHORT TERM...TITUS LONG TERM...VOSS AVIATION...SRF MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
153 PM EDT WED JUN 24 2015 .UPDATE... ISSUED AT 1120 AM EDT WED JUN 24 2015 ONLY MINOR TWEAKS TO THE GOING FORECAST WITH THIS MORNINGS UPDATE. A SHORTWAVE MOVING THROUGH NORTHERN MINNESOTA HAS SPREAD SOME SHOWERS AND A FEW THUNDERSTORMS EAST-SOUTHEAST INTO WESTERN LAKE SUPERIOR...BETWEEN THE APOSTLE ISLANDS AND ISLE ROYALE. EXPECT THIS WAVE TO CONTINUE TO THE EAST AND SPREAD SHOWERS ACROSS THE NORTHERN HALF OF THE KEWEENAW PENINSULA EARLY THIS AFTERNOON. THE QUESTION FOR THIS AFTERNOON WILL BE THE AMOUNT OF SHOWER DEVELOPMENT THAT WILL OCCUR OVER THE LAND AREAS...WHICH WILL BE AIDED BY LAKE BREEZES. SURFACE DEWPOINTS AT THE 11AM WERE IN THE MID-UPPER 50S...BUT THE 12Z KGRB SOUNDING AND RAP ANALYSIS SOUNDINGS SHOW A DECENT POCKET OF DRY AIR JUST ABOVE THE SURFACE AND THROUGH 800MB/7KFT. EXPECT THE SUN THAT IS OCCURRING OVER THE AREA TO AID MIXING OF THAT DRIER AIR TO THE SURFACE OVER THE NEXT COUPLE OF HOURS...WHICH WILL LIMIT THE INSTABILITY OVER THE AREA (DEWPOINTS FALLING INTO THE LOWER 50S AND PROBABLY UPPER 40S TOWARDS THE WISCONSIN BORDER). WHILE THERE WILL BE ENOUGH MOISTURE ABOVE THAT DRY AIR TO DEVELOP CLOUDS AND LIKELY SOME SHOWERS...CONFIDENCE IS LOWER ON WIDESPREAD SHOWERS AND HEAVIER RAIN. MODIFIED SOUNDINGS TO EXPECTED AFTERNOON T/TD VALUES CONTINUES TO SHOW 500-600J/KG OF MLCAPE...SO THUNDER REMAINS POSSIBLE ALONG WITH BRIEF GUSTY WINDS DUE TO ABUNDANT LOW LEVEL DRY AIR PUSHING DCAPE VALUES OVER 800- 900J/KG OVER AT LEAST THE SOUTHERN HALF OF THE CWA. OVERALL EXPECT THE GREATEST FOCUS OF SHOWERS TO BE OVER THE INTERIOR CENTRAL CWA WHEN THEY DEVELOP AROUND MID AFTERNOON AND THEN MOVE TO THE SOUTHEAST AROUND 20-25KTS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 411 AM EDT WED JUN 24 2015 A COLD FRONT AND A SUBTLE UPPER SHORTWAVE WILL MOVE THROUGH TODAY. THESE FEATURES AND LAKE BREEZE FORMATION WILL PROVIDE FORCING FOR CONVECTION MAINLY INLAND FROM THE GREAT LAKES. SBCAPE VALUES SHOULD BE IN THE 500-800J/KG RANGE INLAND...WITH RELATIVELY WEAK SHEAR DUE TO NEARLY CALM WINDS AT AND BELOW 800MB. INVERTED V SOUNDINGS WITH DRY LOW LEVELS AND EVEN AN INDICATION OF AN EML MAY LEAD TO SOME GUSTY WINDS UNDER ANY COLLAPSING STORMS...BUT SEVERE IS NOT EXPECTED AS BEST CONVECTION SHOULD BE WHERE LOW LEVEL MOISTURE IS GREATER...AWAY FROM THE WI BORDER. CONVECTION IS STILL EXPECTED ALONG THE WI BORDER...JUST TO A LESSER EXTENT. NOT SURE ON EXACTLY HOW THINGS PLAY OUT TONIGHT AS A SHORTWAVE CURRENTLY NEAR THE MT/ALBERTA BORDER MOVES INTO OR NEAR THE CWA WHILE A SFC TROUGH MOVES THROUGH. THE NAM...GFS...GEM AND ECMWF HAVE PRECIP MOVING ALONG WITH THESE FEATURES THROUGH THE CWA...BUT A COUPLE OF HIGH-RES MODELS DO NOT SHOW NEARLY THE EXTENT OF PRECIP. AT THIS TIME...SIDED WITH THE MAJORITY OF MODELS AND HAVE HIGH CHANCE TO LIKELY POPS...BUT IS IS ENTIRELY POSSIBLE THAT SOME LOCATIONS WILL STAY DRY TONIGHT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 426 AM EDT WED JUN 24 2015 SEVERAL PERIODS OF LIGHT SHOWERS ARE EXPECTED ACROSS UPPER MICHIGAN DURING THE LONG TERM PERIOD...FIRST WITH LINGERING SHOWERS ON THURSDAY FROM A PASSING SHORTWAVE...AND AGAIN DURING THE LATER PART OF THE WEEKEND AND INTO EARLY NEXT WEEK. THURSDAY...PASSING SHORTWAVE IN A NW FLOW COULD ALLOW SOME ISOLD TO SCT SHOWERS TO LINGER DURING THE MORNING INTO EARLY AFTERNOON HOURS AS MODELS GENERALLY SHOW 200-400 J/KG MLCAPE FOR INSTABILITY OVER INLAND LOCATIONS. OTHERWISE...CONFLUENT FLOW ALOFT AHEAD OF BUILDING RIDGE AND ASSOC MID-LVL Q-VECT DIV/SUBSIDENCE SHOULD GENERALLY LEAD TO DRYING CONDITIONS ESPECIALLY BY LATE AFTERNOON. TEMPORARY SPLIT-FLOW PATTERN DEVELOPING WILL ALLOW AN AREA OF SFC HIGH PRESSURE TO DROP SOUTHEAST ACROSS THE UPPER GREAT LAKES REGION THU NIGHT AND PERSIST INTO SATURDAY RESULTING IN MAINLY DRY CONDITIONS. 00Z NAM HINTS AT A FEW DIURNAL SHOWERS DEVELOPING ON FRIDAY ALONG THE LAKE BREEZES BUT FOR NOW WL MAINTAIN DRY FCST AS MID-LVLS WILL LIKELY BE TOO DRY FOR SHRA DEVELOPMENT. OTHERWISE SHOULD SEE PARTLY CLOUDY TO MOSTLY CLEAR SKIES OVER THE AREA. AMPLIFICATION OF UPSTREAM RIDGE OVER THE WRN CONUS ALONG WITH A SERIES OF WAVES DIVING SOUTH THROUGH THE NRN AND CENTRAL PLAINS LATE THIS WEEK WILL HELP AMPLIFY THE UPPER TROUGH OVER THE EASTERN HALF OF THE CONUS FOR THIS WEEKEND. WHILE THE TROUGH WILL WEAKEN AND SHIFT EAST INTO EARLY NEXT WEEK...A SERIES OF SHORTWAVES DROPPING SOUTHEAST INTO THE GREAT LAKES REGION SUNDAY INTO TUESDAY WILL REINFORCE THE UPPER TROUGH OVER THE GREAT LAKES REGION FOR NEXT WEEK. THIS WILL YIELD NORMAL TO BELOW NORMAL TEMPERATURES ALONG WITH PERIODS OF RAIN SHOWERS AND MAYBE EVEN A FEW THUNDERSTORMS. ALSO SOMETHING TO WATCH...THE LATEST 00Z RUN OF THE ECMWF SHOWS 850 MB TEMPS PLUMMETING TO AROUND 1C BY NEXT TUE EVENING (THE LAST DAY OF JUNE)...BRRR! THIS 00Z SOLUTION IS DEFINITELY MORE AMPLIFIED WITH THE MID-UPR TROUGH INTO THE UPPER GREAT LAKES THAN EITHER THE 00Z GFS OR THE PREVIOUS 12Z ECMWF SOLN...ALLOWING A DIRECT PATH FOR ARCTIC AIR TO DIVE SOUTH INTO THE REGION. AGAIN THIS IS JUST ONE MODEL RUN...BUT IT WILL BE SOMETHING TO MONITOR OVER THE NEXT SEVERAL MODEL RUNS AS A TREND TOWARD THIS MORE AMPLIFIED AND COLDER SOLUTION COULD RESULT IN A BRIEF SPELL OF WELL BELOW NORMAL TEMPS FOR THE MIDDLE OF NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 152 PM EDT WED JUN 24 2015 DIURNAL HEATING HAS LED TO THE DEVELOPMENT OF CLOUDS AND SHOWERS OVER THE INTERIOR PORTIONS OF UPPER MICHIGAN...WHILE A WEAK UPPER LEVEL DISTURBANCE MOVING EAST ACROSS THE NORTHERN HALF OF LAKE SUPERIOR IS PRODUCING SHOWERS THERE TOO. EXPECT THE SHOWERS THAT ARE AFFECTING KCMX TO PUSH EAST AND DIMINISH OVER THE NEXT FEW HOURS. MEANWHILE...THE SHOWERS DEVELOPING OVER THE INTERIOR WEST/CENTRAL U.P. WILL CONTINUE TO EXPAND IN COVERAGE AND AFFECT KIWD/KSAW A LITTLE LATER THIS AFTERNOON. THERE IS ENOUGH INSTABILITY FOR SOME RUMBLES OF THUNDER...BUT DIDN/T FEEL CONFIDENT ENOUGH TO INCLUDE AT KSAW/KIWD AND WILL AMEND AS NECESSARY IF THEY DEVELOP. FOR TONIGHT...ANOTHER DISTURBANCE WILL MOVE THROUGH THE AREA AND IT SHOULD LEAD TO SHOWERS AT ALL THREE SITES. DEPENDING ON THE RAIN...COULD SEE SOME PATCHY GROUND FOG DEVELOP AND HAVE INCLUDED A BRIEF MVFR VSBY FOR KSAW DUE TO THAT. THAT DISTURBANCE WILL SHIFT EAST OF THE AREA THROUGH THE DAY TOMORROW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 411 AM EDT WED JUN 24 2015 WINDS WILL REMAIN BELOW 20KTS INTO THE MIDDLE OF NEXT WEEK. A LOW PRESSURE SYSTEM DEVELOPING IN THE CENTRAL PLAINS TODAY WILL SLIDE E THROUGH FRIDAY...WHILE ELONGATING OVER THE TENNESSEE VALLEY. A HIGH OVER W ONTARIO THURSDAY MORNING WILL REMAIN OVER THE W GREAT LAKES THROUGH SATURDAY. THIS RIDGE WILL SLIDE SLOWLY TO THE SE SATURDAY NIGHT INTO SUNDAY AS A LOW SLIDES ACROSS N ONTARIO. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...SRF SHORT TERM...TITUS LONG TERM...VOSS AVIATION...SRF MARINE...TITUS
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1122 AM EDT WED JUN 24 2015 .UPDATE... ISSUED AT 1120 AM EDT WED JUN 24 2015 ONLY MINOR TWEAKS TO THE GOING FORECAST WITH THIS MORNINGS UPDATE. A SHORTWAVE MOVING THROUGH NORTHERN MINNESOTA HAS SPREAD SOME SHOWERS AND A FEW THUNDERSTORMS EAST-SOUTHEAST INTO WESTERN LAKE SUPERIOR...BETWEEN THE APOSTLE ISLANDS AND ISLE ROYALE. EXPECT THIS WAVE TO CONTINUE TO THE EAST AND SPREAD SHOWERS ACROSS THE NORTHERN HALF OF THE KEWEENAW PENINSULA EARLY THIS AFTERNOON. THE QUESTION FOR THIS AFTERNOON WILL BE THE AMOUNT OF SHOWER DEVELOPMENT THAT WILL OCCUR OVER THE LAND AREAS...WHICH WILL BE AIDED BY LAKE BREEZES. SURFACE DEWPOINTS AT THE 11AM WERE IN THE MID-UPPER 50S...BUT THE 12Z KGRB SOUNDING AND RAP ANALYSIS SOUNDINGS SHOW A DECENT POCKET OF DRY AIR JUST ABOVE THE SURFACE AND THROUGH 800MB/7KFT. EXPECT THE SUN THAT IS OCCURRING OVER THE AREA TO AID MIXING OF THAT DRIER AIR TO THE SURFACE OVER THE NEXT COUPLE OF HOURS...WHICH WILL LIMIT THE INSTABILITY OVER THE AREA (DEWPOINTS FALLING INTO THE LOWER 50S AND PROBABLY UPPER 40S TOWARDS THE WISCONSIN BORDER). WHILE THERE WILL BE ENOUGH MOISTURE ABOVE THAT DRY AIR TO DEVELOP CLOUDS AND LIKELY SOME SHOWERS...CONFIDENCE IS LOWER ON WIDESPREAD SHOWERS AND HEAVIER RAIN. MODIFIED SOUNDINGS TO EXPECTED AFTERNOON T/TD VALUES CONTINUES TO SHOW 500-600J/KG OF MLCAPE...SO THUNDER REMAINS POSSIBLE ALONG WITH BRIEF GUSTY WINDS DUE TO ABUNDANT LOW LEVEL DRY AIR PUSHING DCAPE VALUES OVER 800- 900J/KG OVER AT LEAST THE SOUTHERN HALF OF THE CWA. OVERALL EXPECT THE GREATEST FOCUS OF SHOWERS TO BE OVER THE INTERIOR CENTRAL CWA WHEN THEY DEVELOP AROUND MID AFTERNOON AND THEN MOVE TO THE SOUTHEAST AROUND 20-25KTS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 411 AM EDT WED JUN 24 2015 A COLD FRONT AND A SUBTLE UPPER SHORTWAVE WILL MOVE THROUGH TODAY. THESE FEATURES AND LAKE BREEZE FORMATION WILL PROVIDE FORCING FOR CONVECTION MAINLY INLAND FROM THE GREAT LAKES. SBCAPE VALUES SHOULD BE IN THE 500-800J/KG RANGE INLAND...WITH RELATIVELY WEAK SHEAR DUE TO NEARLY CALM WINDS AT AND BELOW 800MB. INVERTED V SOUNDINGS WITH DRY LOW LEVELS AND EVEN AN INDICATION OF AN EML MAY LEAD TO SOME GUSTY WINDS UNDER ANY COLLAPSING STORMS...BUT SEVERE IS NOT EXPECTED AS BEST CONVECTION SHOULD BE WHERE LOW LEVEL MOISTURE IS GREATER...AWAY FROM THE WI BORDER. CONVECTION IS STILL EXPECTED ALONG THE WI BORDER...JUST TO A LESSER EXTENT. NOT SURE ON EXACTLY HOW THINGS PLAY OUT TONIGHT AS A SHORTWAVE CURRENTLY NEAR THE MT/ALBERTA BORDER MOVES INTO OR NEAR THE CWA WHILE A SFC TROUGH MOVES THROUGH. THE NAM...GFS...GEM AND ECMWF HAVE PRECIP MOVING ALONG WITH THESE FEATURES THROUGH THE CWA...BUT A COUPLE OF HIGH-RES MODELS DO NOT SHOW NEARLY THE EXTENT OF PRECIP. AT THIS TIME...SIDED WITH THE MAJORITY OF MODELS AND HAVE HIGH CHANCE TO LIKELY POPS...BUT IS IS ENTIRELY POSSIBLE THAT SOME LOCATIONS WILL STAY DRY TONIGHT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 426 AM EDT WED JUN 24 2015 SEVERAL PERIODS OF LIGHT SHOWERS ARE EXPECTED ACROSS UPPER MICHIGAN DURING THE LONG TERM PERIOD...FIRST WITH LINGERING SHOWERS ON THURSDAY FROM A PASSING SHORTWAVE...AND AGAIN DURING THE LATER PART OF THE WEEKEND AND INTO EARLY NEXT WEEK. THURSDAY...PASSING SHORTWAVE IN A NW FLOW COULD ALLOW SOME ISOLD TO SCT SHOWERS TO LINGER DURING THE MORNING INTO EARLY AFTERNOON HOURS AS MODELS GENERALLY SHOW 200-400 J/KG MLCAPE FOR INSTABILITY OVER INLAND LOCATIONS. OTHERWISE...CONFLUENT FLOW ALOFT AHEAD OF BUILDING RIDGE AND ASSOC MID-LVL Q-VECT DIV/SUBSIDENCE SHOULD GENERALLY LEAD TO DRYING CONDITIONS ESPECIALLY BY LATE AFTERNOON. TEMPORARY SPLIT-FLOW PATTERN DEVELOPING WILL ALLOW AN AREA OF SFC HIGH PRESSURE TO DROP SOUTHEAST ACROSS THE UPPER GREAT LAKES REGION THU NIGHT AND PERSIST INTO SATURDAY RESULTING IN MAINLY DRY CONDITIONS. 00Z NAM HINTS AT A FEW DIURNAL SHOWERS DEVELOPING ON FRIDAY ALONG THE LAKE BREEZES BUT FOR NOW WL MAINTAIN DRY FCST AS MID-LVLS WILL LIKELY BE TOO DRY FOR SHRA DEVELOPMENT. OTHERWISE SHOULD SEE PARTLY CLOUDY TO MOSTLY CLEAR SKIES OVER THE AREA. AMPLIFICATION OF UPSTREAM RIDGE OVER THE WRN CONUS ALONG WITH A SERIES OF WAVES DIVING SOUTH THROUGH THE NRN AND CENTRAL PLAINS LATE THIS WEEK WILL HELP AMPLIFY THE UPPER TROUGH OVER THE EASTERN HALF OF THE CONUS FOR THIS WEEKEND. WHILE THE TROUGH WILL WEAKEN AND SHIFT EAST INTO EARLY NEXT WEEK...A SERIES OF SHORTWAVES DROPPING SOUTHEAST INTO THE GREAT LAKES REGION SUNDAY INTO TUESDAY WILL REINFORCE THE UPPER TROUGH OVER THE GREAT LAKES REGION FOR NEXT WEEK. THIS WILL YIELD NORMAL TO BELOW NORMAL TEMPERATURES ALONG WITH PERIODS OF RAIN SHOWERS AND MAYBE EVEN A FEW THUNDERSTORMS. ALSO SOMETHING TO WATCH...THE LATEST 00Z RUN OF THE ECMWF SHOWS 850 MB TEMPS PLUMMETING TO AROUND 1C BY NEXT TUE EVENING (THE LAST DAY OF JUNE)...BRRR! THIS 00Z SOLUTION IS DEFINITELY MORE AMPLIFIED WITH THE MID-UPR TROUGH INTO THE UPPER GREAT LAKES THAN EITHER THE 00Z GFS OR THE PREVIOUS 12Z ECMWF SOLN...ALLOWING A DIRECT PATH FOR ARCTIC AIR TO DIVE SOUTH INTO THE REGION. AGAIN THIS IS JUST ONE MODEL RUN...BUT IT WILL BE SOMETHING TO MONITOR OVER THE NEXT SEVERAL MODEL RUNS AS A TREND TOWARD THIS MORE AMPLIFIED AND COLDER SOLUTION COULD RESULT IN A BRIEF SPELL OF WELL BELOW NORMAL TEMPS FOR THE MIDDLE OF NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 741 AM EDT WED JUN 24 2015 MAINLY VFR CONDITIONS AS HIGH BASED SHOWERS AND POSSIBLY SOME THUNDER THIS AFTERNOON AND EARLY EVENING. ADDITIONAL SHOWERS WILL MOVE IN FROM THE WEST THIS EVENING/TONIGHT...BRINGING SOME LOWERING CIGS LATE TONIGHT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 411 AM EDT WED JUN 24 2015 WINDS WILL REMAIN BELOW 20KTS INTO THE MIDDLE OF NEXT WEEK. A LOW PRESSURE SYSTEM DEVELOPING IN THE CENTRAL PLAINS TODAY WILL SLIDE E THROUGH FRIDAY...WHILE ELONGATING OVER THE TENNESSEE VALLEY. A HIGH OVER W ONTARIO THURSDAY MORNING WILL REMAIN OVER THE W GREAT LAKES THROUGH SATURDAY. THIS RIDGE WILL SLIDE SLOWLY TO THE SE SATURDAY NIGHT INTO SUNDAY AS A LOW SLIDES ACROSS N ONTARIO. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...SRF SHORT TERM...TITUS LONG TERM...VOSS AVIATION...TITUS MARINE...TITUS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1104 PM CDT TUE JUN 23 2015 .UPDATE...CLUSTER OF STORMS OVER TN WILL MAKE A MORE SOUTHWARD PUSH AND LIKELY ENTER THE N-CENTRAL AND NE PORTIONS OF THE CWA AS IT BEGINS TO WEAKEN. THE LATEST ANALYSIS ALONG WITH HRRR GUID SUPPORTS THE STORM CLUSTER TO MAKE A MUCH FURTHER SOUTHWARD PROGRESS THAN EXPECTED. LOW LEVEL TRAJECTORIES SUPPORT STORM PROPAGATION INTO THE NE CWA WITH TIMING OF THE CLUSTER BETWEEN 1-2 AM. VERY ANOMALOUS HEAT/HUMIDITY EXIST FOR THIS TIME OF EVENING AND SBCAPE IS HOLDING AT ROUGHLY 4000 J/KG ALONG WITH SFC THETA E >360 K AND 850MB THETA E AROUND 350 K. THESE INGREDIENTS SHOULD BE PLENTY TO SUPPORT THESE STORMS AS THEY ENTER N/NE MS BUT EXPECTATIONS ARE FOR THINGS TO BECOME LESS FAVORABLE AS THEY NEAR THE CWA BOARDER AND THE HWY 82 CORRIDOR. AT THIS POINT...JUST STRONG GUSTS ARE EXPECTED BUT SOME SEVERE THREAT CANNOT BE TOTALLY RULED OUT. HOWEVER...WILL SIDE WITH THE HRRR AND FORECAST WEAKENING AS IT NEARS THE CWA. THE FORECAST HAS BEEN ADJUSTED TO INCREASE POPS. /CME/ && .AVIATION...VFR CONDITIONS WILL PREVAIL MORE HAZY HOT CONDITIONS. LIKE THE PREV DAYS...THE HAZE LOOKS TO NOT IMPACT CONDITIONS WITH VIS REMAINING AT 6SM OR GREATER. MORE OF AN OPPORTUNITY FOR CONVECTION LOOKS TO EXIST AFTER 21Z WED AND VCTS WAS INCLUDED FOR THAT PERIOD AT A FEW LOCATIONS. /CME/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 77 96 76 93 / 9 33 27 40 MERIDIAN 76 96 74 94 / 13 38 27 45 VICKSBURG 76 96 75 93 / 6 29 25 33 HATTIESBURG 76 97 75 93 / 5 48 37 50 NATCHEZ 75 94 75 91 / 5 37 32 35 GREENVILLE 76 98 77 95 / 12 18 14 31 GREENWOOD 76 95 76 94 / 25 21 16 34 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...HEAT ADVISORY FROM 11 AM TO 7 PM CDT WEDNESDAY FOR MSZ026>033- 036>039-042>046-048>052. HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR MSZ018-019-025-034- 035-040-041-047-053. LA...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR LAZ007>009-015-016- 023-025. AR...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR ARZ074-075. && $$ CME
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1202 AM CDT Wed Jun 24 2015 .SHORT TERM...(This Evening through Thursday) Issued at 200 PM CDT TUE JUN 23 2015 A front has stalled out across the area. This frontal boundary shows up very nicely on the visible satellite imagery and surface obs this afternoon. The front was currently located from near Nevada to near Eminence. This front will start to slowly back up northward later this evening and tonight. There is a complex of storms northwest of the Kansas City area which are moving east- southeastward. The latest Hi-Res models suggest this complex if it holds together may clip our central Missouri counties late this afternoon and early evening. The HRRR and the ARW continues to suggest a few isolated showers and storms developing near the stalled out frontal boundary across central Missouri into the eastern Missouri Ozarks. There will be a limited risk for a strong storm or two with small hail and gusty winds as the main threat. Any convection should either dissipate or move off to the east of the area after sunset. Wednesday and Thursday will be hot and humid with the upper level ridge nosing in a bit over the area. High temperatures may be a couple degrees warmer than today with most areas in the lower to middle 90s. Heat index will be around 100. Southwest winds will be gusty up to 30 mph for areas west of Highway 65. .LONG TERM...(Thursday Night through Tuesday) Issued at 200 PM CDT TUE JUN 23 2015 A stronger shortwave will move through the Midwest and Ohio River Valley region on Friday. This feature will begin to carve out a trough across the eastern U.S. while an upper level ridge builds across the western U.S. A cold front will move down into the region starting Thursday night. Showers and thunderstorms will begin to impact portions of central Missouri late Thursday night and area wide by Friday. Will not rule out a few strong storms possible Friday with gusty winds and small hail the main threats. The front will clear through the area by Friday night with rain ending from north to south. The weekend is shaping up to be extremely nice. Drier air will move into the area with dewpoints in the 50s. The latest model guidance came in a degree or two cooler with lows Saturday night and Sunday night in the upper 50s to lower 60s. Highs will be in the upper 70s to lower 80s and Mostly sunny skies. Looks like the below average temperatures will continue into early next week. Another weak front may try to move into the area by Monday night with a few showers and storms possible. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday Night) Issued at 1159 PM CDT TUE JUN 23 2015 Mostly clear skies and VFR conditions will continue through Wednesday evening. Winds will increase out of the southwest on Wednesday and will become somewhat gusty around Joplin. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ SHORT TERM...Griffin LONG TERM...Griffin AVIATION...Schaumann
AREA FORECAST DISCUSSION
NWS BILLINGS MT
328 PM MDT WED JUN 24 2015 .SHORT TERM...VALID FOR THU AND FRI... THUNDERSTORMS REMAIN THE MAIN FOCUS IN THE SHORT TERM. THUNDERSTORM CHANCES THE REST OF TODAY HAVE SHIFTED TOWARDS BIG HORN AND SHERIDAN COUNTIES. MUCH OF THE ENERGY WHAT WAS EXPECTED TO BE IN THE EASTERN ZONES HAS BEEN DISSIPATED BY CONVECTION EARLIER THIS MORNING. MUCH OF THE HI RES GUIDANCE SHOWS LIMITED CAPE VALUES FROM CUSTER AND POWDER RIVER COUNTIES EASTWARD. ACROSS BIG HORN AND SHERIDAN COUNTIES CAPE VALUES REACH 1000 TO 1200 J/KG ALONG WITH SHEAR VALUES FROM 0 TO 6 KM REACHING 50 TO 60 KNOTS. MID MORNING RUNS OF THE HRRR...ALONG WITH THE 12Z NSSL WRF...SHOWS ACTIVITY DEVELOPING OVER THE THE SNOWY MOUNTAINS AND THEN STRENGTHENING ACROSS BIG HORN COUNTY IN THE BETTER ENVIRONMENT. THE CAVEAT TO THIS IS THE HIGH CLOUDS OVER MUCH OF THE AREA AND THE LOW CLOUDS THAT HAVE HUNG AROUND IN SHERIDAN INTO EARLY AFTERNOON. THE LATEST RUNS OF THE HRRR ARE RATHER QUIET THIS AFTERNOON. EVEN WITH THE SHORTWAVE MOVING THROUGH THE AREA...MODELS ARE NOT GIVING A HIGH DEGREE OF CONFIDENCE IN THE CHANCES FOR THUNDERSTORMS. GIVEN THE SHEAR AND CAPE...AT LEAST ACROSS PART OF THE AREA...IF STORMS CAN DEVELOP THEY HAVE THE POTENTIAL TO BE STRONG TO SEVERE. THE SETUP FOR THURSDAY DOES NOT LOOK AS GOOD FOR SEVERE WEATHER...ALTHOUGH SOME STORMS STILL COULD BE STRONGER. THE AREA WILL BEGIN TO SEE THE INFLUENCE OF THE RIDGE THAT IS BUILDING INTO THE WESTERN US. THIS WILL RESULT IN SUBTLE RISING HEIGHTS. THIS WILL HELP TO DECREASE RAIN CHANCES SOME. THAT SAID ANOTHER SHORTWAVE WILL MOVE ACROSS SOUTHEASTERN MONTANA...WHICH WILL PLACES THE BEST CHANCES FOR CONVECTION AGAIN FROM POWDER RIVER AND CUSTER COUNTIES EAST. FRIDAY THE AREA IS WILL UNDER THE INFLUENCE OF THE BUILDING RIDGE AND WILL SEE RAIN CHANCES DIMINISH. TEMPERATURES WILL ALSO BEGIN THEIR INCREASE INTO THE WEEKEND. REIMER .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... VERY HOT WEATHER IS EXPECTED THIS WEEKEND AND INTO EARLY NEXT WEEK THANKS TO A LARGE 500-MB RIDGE THAT WILL DEVELOP OVER THE WESTERN UNITED STATES. THE MULTI-MODEL CONSENSUS THAT WE USED TO BUILD THE FORECAST CALLS FOR HIGHS WELL INTO THE 90S F SATURDAY AND SUNDAY...AND WE ARE STILL CALLING FOR HIGHS OF 100 F IN MANY SPOTS ON MONDAY WHEN 700-MB TEMPERATURES PEAK AT +15 TO +18 C. THE 12 UTC GFS AND ECMWF SUGGEST THAT THE RIDGE WILL RETROGRADE A BIT NEXT TUESDAY AND WEDNESDAY...WHICH WILL SHOULD LET HIGHS DROP BACK A BIT INTO THE LOWER TO MIDDLE 90S F. THE FORECAST IS ESSENTIALLY A DRY ONE AT THIS POINT SINCE MODEL OUTPUT HAS ONLY A WEAK SIGNAL OF MONSOONAL MOISTURE REACHING THE REGION UNDERNEATH THE LARGE RIDGE ALOFT. SCHULTZ && .AVIATION... A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE ACROSS SOUTHERN MT AND NORTH CENTRAL WY THROUGH TONIGHT...BUT OUR CONFIDENCE IS LOW WITH REGARD TO THE COVERAGE OF THAT ACTIVITY. SUB-VFR CONDITIONS ARE POSSIBLE IN ANY STORMS THAT DEVELOP...BUT VFR WEATHER WILL OTHERWISE PREVAIL THROUGH TONIGHT. SCHULTZ && .PRELIMINARY POINT TEMP/POPS... THU FRI SAT SUN MON TUE WED ----------------------------------------------------------- BIL 060/084 060/091 061/093 063/096 066/100 068/094 064/090 22/T 10/U 00/U 01/U 11/U 11/B 11/U LVM 053/086 051/093 053/095 056/098 056/100 059/093 056/093 21/B 10/U 01/U 11/U 11/B 11/B 11/B HDN 060/086 057/093 060/095 063/099 064/101 066/095 063/091 33/T 20/B 00/U 00/U 00/G 11/B 11/U MLS 059/083 059/088 061/093 062/095 063/097 066/092 063/089 23/T 21/B 00/U 00/U 00/U 11/B 11/U 4BQ 059/081 058/086 058/090 060/093 062/095 065/092 061/088 34/T 31/B 00/U 00/U 11/U 11/B 11/U BHK 056/080 057/084 058/089 059/089 061/091 062/086 059/084 24/T 31/B 10/U 00/U 00/U 11/B 12/T SHR 057/080 054/085 055/088 056/091 057/093 061/091 058/086 33/T 21/B 10/U 11/U 11/U 11/B 11/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
557 PM MDT THU JUN 25 2015 .AVIATION... 00Z TAF CYCLE SCATTERED THUNDERSTORMS WILL CONTINUE UNTIL AROUND 03Z BEFORE GRADUALLY DIMINISHING. AN UPPER LEVEL NLY WIND SPEED MAX MOVING THROUGH ERN NM THIS EVENING AND OVERNIGHT WILL KEEP CONVECTION GOING FROM CENTRAL HIGHLANDS AND SOUTH-CENTRAL MTNS EAST TO EAST- CENTRAL PLAINS UNTIL AROUND 07Z INCLUDING KTCC AND POSSIBLY AS FAR SOUTH AS KROW. BRIEF PERIOD OF MODERATE EAST WINDS POSSIBLE AT KABQ BTWN 02Z-05Z. ANOTHER ROUND OF AFTERNOON AND EVENING CONVECTION EXPECTED FRIDAY BUT STORMS OVER CENTRAL AND EASTERN AREAS WILL BE MARKEDLY STRONGER DUE TO A STRONG BACKDOOR COLD FRONT DROPPING INTO ERN PLAINS. 33 && .PREV DISCUSSION...317 PM MDT THU JUN 25 2015... .SYNOPSIS... AN ACTIVE PERIOD OF WEATHER WILL BE THE RULE THROUGH AT LEAST MONDAY. STORMS SHOULD EXPAND IN COVERAGE TONIGHT ACROSS THE EASTERN PLAINS...PERHAPS RESULTING IN AN EAST CANYON WIND IN THE RIO GRANDE VALLEY. STORM COVERAGE WILL INCREASE FURTHER ON FRIDAY THANKS TO A BACK DOOR COLD FRONT PUSHING THROUGH THE GAPS OF THE CENTRAL MOUNTAIN CHAIN. MOISTURE BEHIND THE FRONT WILL FUEL THUNDERSTORMS THROUGH THE WEEKEND INTO MONDAY. SLOW STORM MOTIONS AND HEAVY RAIN MAY LEAD TO FLASH FLOODING...ESPECIALLY ACROSS VULNERABLE DRAINAGES. A DOWNTREND IN STORM COVERAGE IS POSSIBLE TUESDAY AND WEDNESDAY...BUT STORM ACTIVITY WILL QUICKLY RAMP BACK UP AGAIN ON THURSDAY THANKS TO ANOTHER BACK DOOR FRONT AND MOISTURE SURGE. && .DISCUSSION... AS EXPECTED...ANOTHER CROP OF SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ACROSS THE HIGHER TERRAIN. AS THE UPPER HIGH REBUILDS OVER THE FOUR CORNERS...STEERING FLOW WILL CONTINUE TO TAKE STORMS TOWARD THE SOUTH. THUS FAR...STORMS HAVE BEEN MOVING JUST ENOUGH...AND HAVE BEEN PULSEY ENOUGH...TO NOT CAUSE TOO MANY WATER ISSUES. HI-RES MODELS SHOWING STORMS FIRING ALONG A BOUNDARY NEAR THE E NM/E CO BORDER THROUGH THE REMAINDER OF THE AFTN. APPEARS THAT STORMS MAY GET SOMEWHAT ORGANIZED INTO A CLUSTER...FORMING A COLD POOL...WITH STORMS PROPAGATING SOUTHWARD ACROSS THE PLAINS ALONG THE OUTFLOW BOUNDARY. THE QUESTION WILL BE HOW FAR SOUTH THE STORMS CAN HOLD TOGETHER BEFORE THE OUTFLOW BOUNDARY OUTRACES THE STORMS. HRRR KEEPS STORMS TOGETHER AS FAR SOUTH AS ROSWELL...BUT THE NAM SHOWS PRECIP FALLING APART SHORT OF THERE. NONETHELESS...HAVE INCREASED POPS ACROSS THE EASTERN PLAINS TONIGHT. THE SMALL DISTURBANCE NOTED ON WV SATELLITE IMAGERY NOSING INTO NE NM ATTM SHOULD AID IN STORM DEVELOPMENT AND MAINTENANCE. DEPENDING ON IF STORMS FIRE ALONG THE EAST SLOPES OF THE SANDIAS...AS THE HRRR SUGGESTS...COULD SEE A PRETTY STRONG...BUT SHORT-LIVED...EAST WIND INTO THE RGV. FRIDAY LOOKS TO BE MORE ACTIVE THAN TODAY...ESPECIALLY ACROSS THE PLAINS. THOUGH THE REMNANT BOUNDARY FROM TONIGHTS CONVECTION SHOULD BE SOMEWHERE ACROSS THE PLAINS TOMORROW...A BACK DOOR FRONT...LIKELY CONVECTIVELY AIDED... WILL SLIDE DOWN THE PLAINS EARLY FRIDAY. THUS...MULTIPLE ROUNDS OF STORMS WILL BE POSSIBLE...INITIALLY WITH THE FRONT...AND THEN AGAIN LATER IN THE DAY AFTER THE FRONT NUDGES UP TO THE CENTRAL MTN CHAIN...IGNITING STORMS...AND THOSE STORMS SHOULD TRAVEL S OR SE-WARD OUT INTO THE PLAINS ONCE AGAIN. MEANWHILE...THE FRONT WILL PUSH THROUGH THE CENTRAL MOUNTAIN CHAIN BY EARLY-MID AFTN...SPILLING LOW LEVEL MOISTURE WESTWARD. THUS...EXPECT ANOTHER ROUND OF STORMS ACROSS WESTERN NM AS WELL...PERHAPS WITH BETTER COVERAGE THAN TODAY. EAST CANYON WINDS SHOULD ONCE AGAIN BE PRETTY STRONG. WITH ABUNDANT MOISTURE /PWATS LIKELY ABOVE 1 INCH AREAWIDE/... NORTH TO SOUTH STEERING FLOW...AND LOW LEVEL S TO SELY FLOW THROUGH THE WEEKEND...AN ACTIVE PERIOD MIGHT BE AN UNDERSTATEMENT. STEERING FLOW WILL REMAIN WEAK...AND STORMS CONTAINING HEAVY RAIN IS A CERTAINTY. THIS SPELLS A RECIPE FOR FLASH FLOOD POTENTIAL...AND A FLASH FLOOD WATCH MAY BE NEEDED. MONDAY LOOKS TO BE MORE OF THE SAME...THOUGH A WEAK BOUNDARY WILL ALSO NOSE INTO NE NM AS WELL. ON TUESDAY AND WEDNESDAY... DRIER AIR LOOKS TO CIRCLE AROUND THE HIGH AND OVER NM. THOUGH THIS SHOULD LIMIT CONVECTIVE COVERAGE OVER THE FRI-SUN PERIOD...THERE WILL STILL BE ENOUGH MOISTURE AROUND FOR THE HIGH TERRAIN TO SEE SOME ACTION. ACTIVITY RAMPS BACK UP ON THURSDAY THANKS TO ANOTHER BACK DOOR FRONT REPLENISHING MOISTURE ACROSS THE STATE. CURRENT INDICATIONS IS THAT THIS FRONT WILL ALSO PUSH THROUGH THE GAPS OF THE CENTRAL MTN CHAIN...SETTING THE STAGE FOR NUMEROUS SHRA/TSRA THURS...AND FRIDAY. ANOTHER FRONT...OR PERHAPS OUTFLOW BOUNDARY FROM CONVECTION MAY ARRIVE ON THE 4TH OF JULY. LOOKS LIKE MOTHER NATURE WILL PROVIDE HER OWN FIREWORKS AGAIN THIS YEAR. 34 && .FIRE WEATHER... NO REAL BIG CHANGES. A MORE SIGNIFICANT PUSH OF MOISTURE FROM NORTHEAST TO SOUTHWEST WILL OCCUR TONIGHT THROUGH FRIDAY NIGHT VIA A BACK DOOR COLD FRONT. THIS SURGE WILL KICK OFF A WET PHASE TO THE MONSOON PERIOD. AS FAR AS THE REST OF TODAY...HIT AND MISS STORMS CONTAINING WETTING RAIN WILL IMPACT MOST OF THE AREA THROUGH THIS EVENING. THE MAIN FOCUS AREA FOR WETTING RAIN WILL BE FOUND ACROSS EASTERN/CENTRAL AREAS. THUNDERSTORMS SHOULD BLEED INTO THE EARLY MORNING HOURS ON FRIDAY. EXPECT GOOD TO EXCELLENT HUMIDITY RECOVERIES. GUSTY OUTFLOW WIND WILL BE ASSOCIATED WITH SOME OF THE STORMS. THE LOWEST HUMIDITY WILL BE FOUND ACROSS THE FAR NORTHWEST. STORMS WILL TEND TO MOVE TOWARDS A SOUTHERLY DIRECTION AND GENERALLY BE SLOW MOVING. AS THE UPPER RIDGE SHIFTS FURTHER NORTHWEST OF THE STATE ON FRIDAY. THIS WILL ALLOW A VIGOROUS BACK DOOR COLD FRONT TO SWEEP UNDERNEATH AND REENERGIZE MOISTURE SUPPLIES WITHIN THE PERIPHERY OF THE UPPER HIGH. HUMIDITY VALUES WILL GO UP AND TEMPERATURES WILL LOWER. A FOCUS FOR WIDESPREAD WETTING RAIN WILL BE FOUND ALONG THIS FRONTAL PUSH. CENTRAL AND EASTERN AREAS SHOULD BE FAVORED FRIDAY/FRIDAY NIGHT AND THEN SHIFT WESTWARD ON SATURDAY. WETTING THUNDERSTORM COVERAGE SHOULD LOWER SLIGHTLY ON SUNDAY BUT STILL BE PRETTY WIDESPREAD. HIGHER HUMIDITY AND COOLER TEMPERATURES WILL ALSO PREVAIL DURING THIS PERIOD. OUTFLOW WIND GUSTS WILL BE AROUND BUT NOT AS STRONG COMPARED TO A DRIER ATMOSPHERIC ENVIRONMENT. RESIDUAL IMPACTS OF THE MOISTURE TRAPPED WITHIN THE UPPER HIGH WILL CONTINUE EARLY NEXT WEEK. ANOTHER BACK DOOR COLD FRONT IS POSSIBLE SUNDAY NIGHT. A GRADUAL DRYING TREND IS EXPECTED TUESDAY AND COULD POSSIBLY TREND INTO WEDNESDAY. BY LATE WEEK ANOTHER BACK DOOR COLD FRONT SHOULD REPLENISH THE MOISTURE LOST EARLIER IN THE WAY AND INCREASE WETTING THUNDERSTORM COVERAGE. OVERALL VENTILATION WILL BE THE LOWEST DURING THE WEEKEND DUE TO REDUCED MIXING HEIGHTS...PLENTY OF CLOUD COVER AND LOWER TRANSPORT WINDS. 50 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 48
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
200 PM EDT WED JUN 24 2015 .SYNOPSIS... HIGH PRESSURE WILL RESULT IN DRY WEATHER WITH INCREASING AMOUNTS OF SUNSHINE THIS AFTERNOON. A PASSING WAVE OF LOW PRESSURE WILL BRING SHOWERS THROUGH THE REGION LATE THURSDAY. OUR PATTERN WILL REMAIN SLIGHTLY COOLER THAN NORMAL...AND UNSETTLED WITH PERIODIC CHANCES OF SHOWERS THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... 9 AM UPDATE... VISIBLE SATELLITE IMAGERY SHOWS AN OVC LAYER OF STRATOCUMULUS ACROSS NORTH CENTRAL NY TO THE CATSKILLS...EASTERN SOUTHERN TIER OF NY AND SOUTH INTO THE POCONOS AND SCRANTON/WILKES BARRE AREAS OF PA. THIS LAYER WAS BTWN 1800 AND 3000 FEET AND SLOWLY DEVELOPING TO THE W-SW AS A LOW-LEVEL NW FLOW ASCENDS UP THE HILLS OF C NY AND NE PA AND SATURATES OUT. THIS IS AIDED BY SOME BOUNDARY LAYER HEATING. AS THE BNDRY LAYER HEATS AND GROWS INTO THE AFTERNOON DRIER AIR FROM ABOVE WILL ENTRAIN DOWNWARD AND MUCH OF THE CLOUDINESS WILL BREAK UP. MODEL SOUNDINGS FROM NAM...GFS...RAP AND HRRR ALL SEEM TO QUICK TO MIX OUT THE OVC LAYER. THE NAM4KM MODEL SOUNDINGS APPEAR TO HAVE THE BEST HANDLE ON THE PRESENT SITUATION AND DELAY THE CLOUDS BREAKING UP INTO THE AFTERNOON. SO WILL FOLLOW NAM 4KM. LOOKING AT THE CU RULE WHICH TAKES THE 850 MB TEMP AND SUBTRACTS THE 1000 MB DWPT THE GFS...NAM AND ECMWF SUGGEST A SCT CUMULUS LAYER THIS AFTERNOON AS THE BNDRY LAYER REACHES ITS MAX HGHT PROBABLY ARND 5-6 KFT. SO WILL KEEP PC SKIES BY MID AFTERNOON AS WE BELIEVE THE PRESENT OVC SC LAYER WILL EVOLVE INTO SCT CU BY 19-20Z. ALSO ADJUSTED TEMPS DOWN A TAD TO ACCOUNT FOR MORE CLOUD COVER. HARD TO BELIEVE IT IS LATE JUNE HERE AT BGM AS THE SKY LOOKS VERY MUCH LIKE NOVEMBER NOW!! 4 AM UPDATE... NORTHWEST WINDS WILL CONTINUE TO ADVECT IN A DRY AIR MASS...AS HIGH PRESSURE SPREADS IN FROM THE MIDWEST. PLENTY OF SUNSHINE CAN BE EXPECTED...WITH HIGHS TODAY MAINLY IN THE 70S...A FEW TO SEVERAL DEGREES SHORT OF CLIMATOLOGY. DEWPOINTS WILL ONLY BE LOW TO MID 50S...WHICH FOR MOST IS VERY COMFORTABLE. QUIET CONDITIONS PERSIST TONIGHT WITH A MAINLY CLEAR SKY...THEN INCREASING HIGH THIN CLOUDS TOWARDS DAWN AHEAD OF THE NEXT DISTURBANCE...WITH LOWS IN THE 50S. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... 4 AM UPDATE... THURSDAY STARTS OFF FAIRLY QUIET...BUT A NORTHERN STREAM SUMMER CLIPPER OF SORTS...WILL ARRIVE FROM THE UPPER MIDWEST MID TO LATE AFTERNOON. MEANWHILE...SOUTHERN STREAM WARM FRONT WILL ATTEMPT TO LIFT NORTHWARD FROM THE MIDATLANTIC STATES BUT WILL FALL SHORT. BAROCLINIC LIFT WILL OCCUR NORTH OF THAT WARM FRONT...AS THE NORTHERN STREAM WAVE ALSO PASSES. HOWEVER...INSTABILITY LOOKING MORE DOUBTFUL...AND THUS EXPECTING MAINLY JUST SHOWERS OR EVEN STRATIFORM RAIN INSTEAD OF THUNDER. I INCLUDE ONLY A SLIGHT CHANCE OF THUNDER IN NORTHEAST PA AT THIS TIME...TO ACCOMPANY LIKELIHOOD OF SHOWERS LATE THURSDAY INTO THURSDAY EVENING. FURTHER NORTH...CHANCES DROP OFF...TO THE POINT THAT SOME PORTIONS OF CENTRAL NY MAY RECEIVE VERY LITTLE RAIN FROM THIS SYSTEM. 00Z NAM APPEARS TO BE SUFFERING FROM CONVECTIVE FEEDBACK GIVEN THE FAIR AMOUNT OF STABILITY...AND THUS ITS QPF AMOUNTS LOOK UNREASONABLE. SOMETHING ON THE ORDER OF UP TO A FEW TENTHS OF AN INCH...OR CONSENSUS OF NON-NAM MODELS...APPEARS MORE PROBABLE...AND THOSE AMOUNTS FOCUSED MAINLY TWIN TIERS SOUTHWARD. WITH TIME...EASTERN UPPER TROUGH WILL BE SETTING UP. SO WHILE CHANCES OF ADDITIONAL SHOWERS FRIDAY-FRIDAY NIGHT ARE NOT THAT HIGH...WE COULD STILL HAVE SCATTERED SHOWERS POPPING UP WITH WEAK SHORTWAVES EMBEDDED IN THE LARGER DEVELOPING TROUGH...COMBINED WITH DIURNAL HEATING. TEMPERATURES THROUGH THE PERIOD WILL GENERALLY BE A FEW TO SEVERAL DEGREES BELOW NORMAL VALUES. && .LONG TERM /SATURDAY THROUGH TUESDAY/... 115 PM EDT UPDATE... CLOSELY FOLLOWED WPC GUIDANCE. A VERY ACTIVE PATTERN CONTINUES AND WILL REMAIN IN PLACE THRU THE END OF THE FORECAST PERIOD. THIS PATTERN CONSISTS OF TROUGHING OVER THE EAST AND RIDGING OVER THE WEST. KEPT A CHANCE FOR PRECIP OVER THE CWA THRU THE WHOLE PERIOD. MULT WAVES WILL RIDE AROUND THE TROUGH AND CREATE ENOUGH UPPR LVL SUPPORT FOR SHOWERS. THIS PATTERN WILL ALSO CREATE CLOUDY SKIES ALONG WITH BELOW NORMAL TEMPS FOR THIS TIME OF YR. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... SCT-BKN CUMULUS HAS EVOLVED FROM AN MVFR STRATOCUMULUS DECK OF THIS MORNING WITH THE STRONG LATE SUMMER SUN. CLOUD BASES WERE UP TO 5 KFT AND MAY EVEN REACH 6 KFT. HAVE TAFS ALL VFR SCT CUMULUS FOR THE AFTERNOON. SKIES WILL CLEAR OUT QUICKLY BY SUNSET. THEN WE WILL SEE HIGH CLOUDS STREAM IN ACRS OUR NRN TAF SITES BTWN 5-6Z AND THESE CLOUDS WILL SPREAD SOUTHWARD BY 12Z-13Z ACRS REST OF TAF SITES. AN ALTOCUMULUS DECK ARND 10 TO 12 KFT WILL REACH KRME AND KSYR BY 12-13Z. THE REST OF THE NY TAFS CUD SEE SOME PATCHY MID CLDS UNDER BKN-OVC CIRRUS. WITH MAINLY CLEAR SKIES MOST OF THE NGT...WE EXPECT IFR FG TO DEVELOP AT LEAST FOR A FEW HOURS AT KELM. CROSS-OVER TEMPS WILL FALL TO ABT 52-53F THIS PM WITH MINS EXPECTED TO BE CLOSE TO 50F AT KELM. OUR LOCAL ELM FOG CHECKLIST RETURNS IFR FOG AT LEAST A FEW HOURS OR SO BETWEEN 9 AND 13Z AND THUS HAVE PATCHY IFR FG AT KELM. REST OF TAFS VFR THRU 18Z THU. WINDS WILL BE NW ARND 10 KNOTS THIS AFTERNOON AND LIGHT WESTERLY AFTER SUNSET AND W-SW 5-10 KNOTS THU AM. .OUTLOOK... THURS NGT/FRI/SAT/SUN/MON...CHANCE OF SHRA AND ASSOCIATED RESTRICTIONS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...PCF NEAR TERM...DJN/MDP SHORT TERM...MDP LONG TERM...MDP AVIATION...DJN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
907 AM EDT WED JUN 24 2015 .SYNOPSIS... HIGH PRESSURE WILL RESULT IN DRY WEATHER WITH INCREASING AMOUNTS OF SUNSHINE THIS AFTERNOON. A PASSING WAVE OF LOW PRESSURE WILL BRING SHOWERS THROUGH THE REGION LATE THURSDAY. OUR PATTERN WILL REMAIN SLIGHTLY COOLER THAN NORMAL...AND UNSETTLED WITH PERIODIC CHANCES OF SHOWERS THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... 9 AM UPDATE... VISIBLE SATELLITE IMAGERY SHOWS AN OVC LAYER OF STRATOCUMULUS ACROSS NORTH CENTRAL NY TO THE CATSKILLS...EASTERN SOUTHERN TIER OF NY AND SOUTH INTO THE POCONOS AND SCRANTON/WILKES BARRE AREAS OF PA. THIS LAYER WAS BTWN 1800 AND 3000 FEET AND SLOWLY DEVELOPING TO THE W-SW AS A LOW-LEVEL NW FLOW ASCENDS UP THE HILLS OF C NY AND NE PA AND SATURATES OUT. THIS IS AIDED BY SOME BOUNDARY LAYER HEATING. AS THE BNDRY LAYER HEATS AND GROWS INTO THE AFTERNOON DRIER AIR FROM ABOVE WILL ENTRAIN DOWNWARD AND MUCH OF THE CLOUDINESS WILL BREAK UP. MODEL SOUNDINGS FROM NAM...GFS...RAP AND HRRR ALL SEEM TO QUICK TO MIX OUT THE OVC LAYER. THE NAM4KM MODEL SOUNDINGS APPEAR TO HAVE THE BEST HANDLE ON THE PRESENT SITUATION AND DELAY THE CLOUDS BREAKING UP INTO THE AFTERNOON. SO WILL FOLLOW NAM 4KM. LOOKING AT THE CU RULE WHICH TAKES THE 850 MB TEMP AND SUBTRACTS THE 1000 MB DWPT THE GFS...NAM AND ECMWF SUGGEST A SCT CUMULUS LAYER THIS AFTERNOON AS THE BNDRY LAYER REACHES ITS MAX HGHT PROBABLY ARND 5-6 KFT. SO WILL KEEP PC SKIES BY MID AFTERNOON AS WE BELIEVE THE PRESENT OVC SC LAYER WILL EVOLVE INTO SCT CU BY 19-20Z. ALSO ADJUSTED TEMPS DOWN A TAD TO ACCOUNT FOR MORE CLOUD COVER. HARD TO BELIEVE IT IS LATE JUNE HERE AT BGM AS THE SKY LOOKS VERY MUCH LIKE NOVEMBER NOW!! 4 AM UPDATE... NORTHWEST WINDS WILL CONTINUE TO ADVECT IN A DRY AIR MASS...AS HIGH PRESSURE SPREADS IN FROM THE MIDWEST. PLENTY OF SUNSHINE CAN BE EXPECTED...WITH HIGHS TODAY MAINLY IN THE 70S...A FEW TO SEVERAL DEGREES SHORT OF CLIMATOLOGY. DEWPOINTS WILL ONLY BE LOW TO MID 50S...WHICH FOR MOST IS VERY COMFORTABLE. QUIET CONDITIONS PERSIST TONIGHT WITH A MAINLY CLEAR SKY...THEN INCREASING HIGH THIN CLOUDS TOWARDS DAWN AHEAD OF THE NEXT DISTURBANCE...WITH LOWS IN THE 50S. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... 4 AM UPDATE... THURSDAY STARTS OFF FAIRLY QUIET...BUT A NORTHERN STREAM SUMMER CLIPPER OF SORTS...WILL ARRIVE FROM THE UPPER MIDWEST MID TO LATE AFTERNOON. MEANWHILE...SOUTHERN STREAM WARM FRONT WILL ATTEMPT TO LIFT NORTHWARD FROM THE MIDATLANTIC STATES BUT WILL FALL SHORT. BAROCLINIC LIFT WILL OCCUR NORTH OF THAT WARM FRONT...AS THE NORTHERN STREAM WAVE ALSO PASSES. HOWEVER...INSTABILITY LOOKING MORE DOUBTFUL...AND THUS EXPECTING MAINLY JUST SHOWERS OR EVEN STRATIFORM RAIN INSTEAD OF THUNDER. I INCLUDE ONLY A SLIGHT CHANCE OF THUNDER IN NORTHEAST PA AT THIS TIME...TO ACCOMPANY LIKELIHOOD OF SHOWERS LATE THURSDAY INTO THURSDAY EVENING. FURTHER NORTH...CHANCES DROP OFF...TO THE POINT THAT SOME PORTIONS OF CENTRAL NY MAY RECEIVE VERY LITTLE RAIN FROM THIS SYSTEM. 00Z NAM APPEARS TO BE SUFFERING FROM CONVECTIVE FEEDBACK GIVEN THE FAIR AMOUNT OF STABILITY...AND THUS ITS QPF AMOUNTS LOOK UNREASONABLE. SOMETHING ON THE ORDER OF UP TO A FEW TENTHS OF AN INCH...OR CONSENSUS OF NON-NAM MODELS...APPEARS MORE PROBABLE...AND THOSE AMOUNTS FOCUSED MAINLY TWIN TIERS SOUTHWARD. WITH TIME...EASTERN UPPER TROUGH WILL BE SETTING UP. SO WHILE CHANCES OF ADDITIONAL SHOWERS FRIDAY-FRIDAY NIGHT ARE NOT THAT HIGH...WE COULD STILL HAVE SCATTERED SHOWERS POPPING UP WITH WEAK SHORTWAVES EMBEDDED IN THE LARGER DEVELOPING TROUGH...COMBINED WITH DIURNAL HEATING. TEMPERATURES THROUGH THE PERIOD WILL GENERALLY BE A FEW TO SEVERAL DEGREES BELOW NORMAL VALUES. && .LONG TERM /SATURDAY THROUGH TUESDAY/... 115 PM EDT UPDATE... CLOSELY FOLLOWED WPC GUIDANCE. A VERY ACTIVE PATTERN CONTINUES AND WILL REMAIN IN PLACE THRU THE END OF THE FORECAST PERIOD. THIS PATTERN CONSISTS OF TROUGHING OVER THE EAST AND RIDGING OVER THE WEST. KEPT A CHANCE FOR PRECIP OVER THE CWA THRU THE WHOLE PERIOD. MULT WAVES WILL RIDE AROUND THE TROUGH AND CREATE ENOUGH UPPR LVL SUPPORT FOR SHOWERS. THIS PATTERN WILL ALSO CREATE CLOUDY SKIES ALONG WITH BELOW NORMAL TEMPS FOR THIS TIME OF YR. && .AVIATION /13Z WEDNESDAY THROUGH SUNDAY/... PATCH OF SC OVER ERN NY BRINGING MVFR CIGS TO SYR AND RME THIS MRNG. BRIEF FOG PSBL WEST OF THE CLDS...ESP AT ITH...OTRW HIPRES WILL BRING MAINLY CLR SKIES AND VFR CONDS TO THE TAF SITES FOR THE NEXT 24 HRS. WINDS WILL BE WEST BHD YSTRDYS COLD FNT...GNRLY 10 KTS OR LESS. .OUTLOOK... THURS AFTN/FRI/SAT/SUN...CHANCE OF SHRA AND ASSOCIATED RESTRICTIONS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...PCF/DJN NEAR TERM...DJN/MDP SHORT TERM...MDP LONG TERM...MDP AVIATION...DGM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
955 PM EDT THU JUN 25 2015 .SYNOPSIS... A COUPLE OF DISTURBANCES IN THE NORTHWEST FLOW ALOFT WILL IMPACT THE AREA TONIGHT. AN UPPER LEVEL TROUGH DIGGING SOUTHEAST INTO THE OHIO VALLEY ON FRIDAY WILL DEEPEN ALONG THE EASTERN SEABOARD OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 955 PM THURSDAY... ...SEVERE THUNDERSTORM WATCH 353 CONTINUES UNTIL MIDNIGHT EDT TONIGHT AREA FROM THE TRIANGLE TO THE NORTHEAST.. THERE HAS BEEN NEARLY CONTINUOUS CONVECTIVE INITIATION THIS EVENING.. ALONG WHAT MAY HAVE BEEN THE REMNANTS OF OUTFLOW FROM EARLY MORNING CONVECTION STRETCHING FROM BURLINGTON TO RALEIGH. MOST OF THE STORMS HAVE BEEN RATHER INTENSE IN WHAT ULTIMATELY WAS A HIGH CAPE ENVIRONMENT ONCE STRONG HEATING FINALLY TOOK HOLD. WHILE THESE STORMS HAVE FINALLY BEGUN MOVE SOUTHEAST AND WEAKEN..AT LEAST TEMPORARILY...THERE IS ANOTHER ROUND OF CONVECTION POSSIBLE AS MERGING SUPERCELLS OVER CENTRAL VA AND/OR OUTFLOW FROM STORMS OVER EASTERN KY APPROACH THE AREA. WHILE A SMALL AREA BETWEEN THE TRIAD AND TRIANGLE HAS BEEN WORKED OVER AND THERE WILL BE SOME SMALL NOCTURNAL COOLING IN THE NEXT COUPLE OF HOURS...THERE SHOULD STILL BE PLENTY OF ENERGY FOR STORMS TO FEED ON...POSSIBLY EVEN REMAINING ROOTED NEAR THE SURFACE. DEEP LAYER SHEAR WILL BE STRONG...35- 40KT...AND BACKED SOUTHEASTERLY SURFACE WINDS WILL MAINTAIN AT LEAST A SMALL AREA OF ENHANCED HELICITY AND A TORNADO THREAT OVER THE NORTHERN COASTAL PLAIN. OTHERWISE...THE PRIMARY CONCERN WILL BE DAMAGING WINDS WITH BOWING SEGMENTS. THE LATEST HRRR BRINGS A CLUSTER OF STORMS THROUGH BETWEEN 04Z AND 09Z...WHICH EXTENDS BEYOND THE CURRENT SEVERE WATCH THAT ENDS AT 05Z...SO SOME CONSIDERATION WILL HAVE TO BE GIVEN TO THAT AS WELL. LOWS TONIGHT WILL BE IN THE LOWER 70S ONCE CONVECTION CLEARS THE AREA. && .SHORT TERM /FRIDAY AND FRIDAY NIGHT/... AS OF 310 PM THURSDAY... THE AREA WILL BE IN BETWEEN TWO SYSTEMS DURING THE DAY ON FRIDAY AND WITH SOME BRIEF SHORT WAVE RIDGING MOVING OVERHEAD...PRECIP SHOULD BE AT A MINIMUM DURING THE DAY (COMPARED TO RECENT DAYS). HOWEVER... THIS WILL BE SHORT LIVED AS OUR NEXT SHORT WAVE APPROACHES DURING THE EVENING OR OVERNIGHT HOURS. PRECIP CHANCES WILL QUICKLY INCREASE THROUGH THE OVERNIGHT HOURS. GIVEN THE FACT THAT THIS WILL OCCUR OVERNIGHT...AM NOT EXPECTING MUCH IN THE WAY OF SEVERE POTENTIAL SINCE INSTABILITY WILL BE WEAK. HOWEVER...SHEAR WILL BEGIN TO INCREASE THROUGH THE EARLY MORNING HOURS OF SATURDAY AS A DEEP LAYER TROUGH GETS CLOSER...THEREFORE A FEW STORMS WILL HAVE THE POTENTIAL TO BECOME MORE ORGANIZED. ANOTHER HOT DAY IS EXPECTED ON FRIDAY (LIKELY OUR LAST FOR THIS CURRENT HEAT WAVE)...WITH MID TO UPPER 90S EXPECTED. HEAT INDEX VALUES MAY APPROACH OR EXCEED 105 DEGREES IN THE SOUTHEAST PORTIONS OF THE CWA...POSSIBLY NECESSITATING A HEAT ADVISORY. OVERNIGHT LOWS WILL GENERALLY BE IN THE LOW/MID 70S. && .LONG TERM /SATURDAY THROUGH THURSDAY/... AS OF 310 PM THURSDAY... AN UPPER LOW WILL DEEPEN OVER THE OHIO VALLEY/GREAT LAKES AS A RATHER DEEP TROUGH DIGS SOUTH INTO THE TN VALLEY. AN ASSOCIATED COLD FRONT WILL APPROACH AND CROSS THE REGION SATURDAY/SATURDAY NIGHT. ALTHOUGH NOT OVERLY IMPRESSIVE...BULK SHEAR VALUES WILL BE ON THE ORDER OF 30 KNOTS. MORE UNCERTAIN WILL BE THE AMOUNT OF INSTABILITY SINCE CONVECTION SHOULD BE ONGOING SATURDAY MORNING...THUS LIMITING THE AMOUNT OF INSOLATION. REGARDLESS...MODELS PROG MARGINAL DESTABILIZATION AND SOME STORMS MAY BECOME STRONG TO SEVERE...WITH DAMAGING WINDS AND HAIL BEING THE PRIMARY THREATS. PRECIP WILL GRADUALLY COME TO AN END LATE SATURDAY NIGHT/EARLY SUNDAY THE FRONT MOVES EAST OF THE AREA. HIGHS ON SATURDAY WILL BE TEMPERED SOME BY THE CLOUDS/PRECIP...WITH MOSTLY MID/UPPER 80S TO LOWER 90S EXPECTED. COOLER AND DRIER AIR WILL FILTER IN BEHIND THE FRONT FOR SUNDAY AND INTO EARLY NEXT WEEK. THIS WILL RESULT IN MOSTLY DRY CONDITIONS AND TEMPS ACTUALLY BEING BELOW NORMAL. LONGWAVE TROUGHING WILL SET UP OVER THE EAST COAST THROUGH MUCH OF NEXT WEEK...WITH IT BECOME SLIGHTLY MORE AMPLIFIED BY THE MIDDLE OF THE WEEK. GIVEN THIS SET UP...ANY SHORT WAVE CROSSING THE REGION WILL BRING A CHANCE FOR SHOWERS/STORMS...ESPECIALLY WEDNESDAY/THURSDAY. TEMPS WILL GRADUALLY MODERATE...WITH MOSTLY NEAR TO SLIGHTLY ABOVE NORMAL EXPECTED. && .AVIATION /00Z THURSDAY THROUGH TUESDAY/... AS OF 735 PM THURSDAY 24 HOUR TAF PERIOD: CONVECTION CURRENTLY OCCURRING IN THE VICINITY OF KRDU WITH A THUNDERSTORM HEADED FOR THE TERMINAL AT THIS TIME. EXPECT THIS ACTIVITY TO CONTINUE FOR THE NEXT COUPLE OF HOURS. OTHER TERMINALS NOT AFFECTED AT THIS TIME BUT KRWI AND KFAY COULD SEE VICINITY SHOWERS OR STORMS OVER THE NEXT COUPLE OF HOURS. A SECOND ROUND OF CONVECTION COMING OUT OF EASTERN KY COULD AFFECT NORTHERN COUNTIES LATER DURING THE OVERNIGHT HOURS WITH KRWI THE MOST LIKELY TO SEE STRONGER CONVECTION BUT KRDU AND TO A LESSER EXTENT KGSO AND KINT ARE NOT COMPLETELY OUT OF THE PICTURE EITHER. WITH THIS LINE OF STORMS STRONG WINDS GENERALLY OUT OF THE NORTHWEST ARE PROBABLE. AFTER STORMS PASS OVERNIGHT...THERE IS A POTENTIAL FOR SOME FOG/LOW STRATUS IN THE NORTHEAST. OTHERWISE CONDITIONS WILL RETURN TO VFR AND SHOULD REMAIN THERE THROUGH THE END OF THE TAF PERIOD. LONG TERM: THE BEST CHANCE FOR ADVERSE CONDITIONS IN THE LONG TERM WILL BE ON SATURDAY WITH A FRONTAL SYSTEM PROGRESSING ACROSS THE AREA EXPECTED TO BRING WIDESPREAD RAINFALL TO THE AREA. SUB-VFR CONDITIONS ARE PROBABLE THROUGH SUNDAY MORNING BEFORE CLEARING OUT FROM NW TO SE WITH A RETURN TO VFR CONDITIONS PERSISTING THROUGH EARLY NEXT WEEK. && .CLIMATE... REC DAY MAX YR RDU RECORDS 06/25 100 1952 06/26 102 1952 GSO RECORDS 06/25 101 1914 06/26 102 1914 FAY RECORDS 06/25 102 1914 06/26 101 1951 && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RAH NEAR TERM...ELLIS/22 SHORT TERM...KRD LONG TERM...KRD AVIATION...ELLIS CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
347 PM EDT WED JUN 24 2015 .SYNOPSIS... HOT AND HUMID CONDITIONS WILL PERSIST THROUGH THE END OF THE WEEK WITH ISOLATED SHOWERS AND THUNDERSTORMS PRIMARILY DURING THE AFTERNOONS AND EVENINGS. MUCH COOLER TEMPERATURES ALONG WITH A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS WEEKEND. A DRYING TREND WILL BEGIN NEXT WEEK AS FRONT STALLED IN THE AREA DISSIPATES AND HIGH PRESSURE RETURNS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 200 PM WEDNESDAY...A HEAT ADVISORY REMAINS IN EFFECT THROUGH EARLY THIS EVENING AS TEMPS SOAR INTO AND THROUGH THE 90S ONCE AGAIN AND COMBINE WITH A VERY HUMID AIR MASS TO CREATE DANGEROUS HEAT. VISIBLE IMAGERY KEEPING MOSTLY SUNNY SKIES OVER MUCH OF THE AREA VERY EARLY THIS AFTERNOON BUT CU WAS DEVELOPING AND CLUSTERING MAINLY OVER NORTHERN TIER COUNTIES WITH SOME ALSO EVIDENT ALONG SEA BREEZE BOUNDARY. NORTHERLY WINDS REACHING DOWN TO NORTH/SC BORDER EARLY THIS AFTN AS WEAKENING COLD FRONT DROPS SLOWLY SOUTH. THIS WILL HELP TO ADVECT SLIGHTLY DRIER AIR IN FROM THE N-NW AND WILL CREATE A TIGHTER GRADIENT FLOW AND ENHANCED LOW LEVEL CONVERGENCE. OVERALL IT WILL JUST PRODUCE A WIND SHIFT TO A MORE N-NE DIRECTION BEHIND IT AS IT REACHES DOWN ALONG THE NC/SC BORDER CUTTING ACROSS OUR LOCAL FORECAST AREA THIS AFTERNOON. THE MUCH DRIER AIR WILL REMAIN WELL TO THE NORTHWEST AS SW FLOW AT THE SURFACE CONTINUES TO KEEP A MOISTURE RICH AIR MASS OVER MUCH OF LOCAL FORECAST AREA....WITH DEWPOINT TEMPS INTO THE 70S AND PCP WATER VALUES NEAR 2 INCHES. ML CAPE VALUES WERE REACHING CLOSE TO 4000 J/KG WITH LI VALUES TO -11. THIS UNSTABLE ENVIRONMENT WILL INCREASE THE POTENTIAL FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON. OVERALL THE FORCING WILL BE SHALLOW WITH STEEP LOW LEVEL LAPSE RATES TO INITIATE STORM DEVELOPMENT THIS AFTERNOON. THE FOCUS OF CONVECTION WILL BE ALONG THIS SFC BOUNDARY AS IT SHIFTS SLIGHTLY SOUTH THROUGH THIS AFTERNOON AND COMBINES WITH ENHANCED CONVERGENCE ALONG SEA BREEZE BOUNDARY AS IT ADVANCES INLAND ALONG WITH OTHER LOCALIZED BOUNDARIES. WITH ALL THIS BEING SAID...THERE IS NOT MUCH IN THE WAY OF UPPER LEVEL SUPPORT AS WE REMAIN ON THE TOP OF RIDGE ALOFT. THE SW FLOW FROM THE SFC THROUGH THE LOW LEVEL FLOW WILL VEER TO BECOME MORE WESTERLY WHICH WILL AID IN DOWNSLOPE FLOW AND HEATING...SOME DRYING AND WILL ALSO HELP TO KEEP SEA BREEZE PINNED CLOSER TO THE COAST INITIALLY. AS HEATING INCREASES EXPECT CU AND SHWRS/TSTMS TO FORM ALONG CONVERGENT BOUNDARIES. SPC HAS KEPT OUR AREA IN A MARGINAL RISK FOR SVR STORMS AS A MODERATELY UNSTABLE AIR MASS YIELDS STRONG UPDRAFT/DOWNDRAFT GROWTH WITH POTENTIAL FOR ISOLATED DAMAGING WINDS. THE HRRR SHOWS MAIN FOCUS ALONG WEAKENING FRONT FROM MARLBORO TO PENDER COUNTIES BY 18Z AND OTHER MORE ISOLATED CONVECTIVE DEVELOPMENT ALONG SEA BREEZE FROM GEORGETOWN COUNTY UP THROUGH THE GRAND STRAND INTO THE CAPE FEAR AREA. THE STEERING FLOW WILL BE OUT OF THE NW WHICH WILL PUSH ALL STORMS SOUTHEAST AND TOWARD THE COAST WITH OTHER STORMS DEVELOPING ALONG COLLIDING BOUNDARIES. MOST OF THIS ACTIVITY WILL END THIS EVENING AS CONVECTION WILL BE ALMOST EXCLUSIVELY DIURNALLY FORCED. KEPT SOME LINGERING POPS INTO LATE THIS EVENING BUT NOT TOO CONFIDENT AS TO HOW MUCH WILL LINGER AFTER DARK. MIN TEMPS TONIGHT WILL AGAIN BE QUITE WARM...DROPPING ONLY TO AROUND 80 AT THE BEACHES...75 WELL INLAND. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...LONG LIVED MID LEVEL RIDGE WILL START SHOWING SIGNS OF WEAKENING DURING THE PERIOD ALTHOUGH THE HEAT AND HUMIDITY WILL CONTINUE. RIDGE HOLDS ON THU BUT STARTS TO BREAK DOWN LATER FRI AS 5H TROUGH APPROACHES FROM THE NORTHWEST. AT THE SURFACE THE BERMUDA HIGH AND PIEDMONT TROUGH REMAIN IN PLACE ALONG WITH DAILY DEVELOPMENT OF THE AFTERNOON SEA BREEZE. DEEP MOISTURE REMAINS IN PLACE WITH PRECIPITABLE WATER VALUES RUNNING BETWEEN 1.75 AND 2 INCHES. MID LEVEL LAPSE RATES ARE STEEP ENOUGH FOR DEVELOPMENT OF MODERATE TO STRONG UPDRAFTS WITH ONLY A SHALLOW LAYER OF LESS FAVORABLE LAPSE RATES TO OVERCOME. THE PROBLEM IS THE HEIGHT OF THIS SHALLOW STABLE LAYER WHICH IS BASED BETWEEN 7K AND 8K FT. THIS MAY BE TOO HIGH FOR THE SEA BREEZE AND PIEDMONT TROUGH TO OVERCOME ON THEIR OWN. ATMOSPHERE MAY REQUIRE SOME BOUNDARY INTERACTION...WITH LEFT OVER CONVECTIVE BOUNDARIES...AND HEATING BEFORE DEEPER CONVECTION IS ABLE TO DEVELOP. WILL CARRY CHC POP EACH AFTERNOON BUT FAVOR A LATER TIMING GIVEN THE AFOREMENTIONED LIMITATIONS. TEMPERATURES WILL CONTINUE TO RUN WELL ABOVE CLIMO WITH HIGHS IN THE MID 90S AND LOWS IN THE MID TO UPPER 70S. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY...MID LEVEL TROUGH AND STALLED SURFACE BOUNDARY WILL RESULT IN UNSETTLED WEATHER FOR MUCH OF THE PERIOD. LARGE 5H TROUGH SETS UP OVER THE EASTERN CONUS BUT THE TROUGHS AXIS WILL REMAIN WEST OF THE AREA THROUGH TUE. COMBINATION OF DIURNAL HEATING...DEEP AND MOIST SOUTHWEST FLOW...AND AN OCCASIONAL SHORTWAVE ROTATING AROUND THE BASE OF THE TROUGH WILL LEAD TO AN INCREASE IN SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE AREA. BEST CHANCES WILL BE SAT INTO SUN AS THE TROUGH ARRIVES AND PUSHES A COLD FRONT INTO THE AREA. DEEP MOISTURE PRESENT AHEAD OF THE TROUGH ALONG WITH SHORTWAVE ENERGY WARRANTS AT LEAST HIGH CHC TO LIKELY POP SAT. MOISTURE LINGERS THROUGH THE FIRST HALF OF SUN BUT LOW LEVEL INSTABILITY DECREASES. WILL HOLD ONTO PRECIP CHANCES SUN AND SUN NIGHT BUT TREND POP DOWNWARD...ESPECIALLY SUN NIGHT. MID LEVEL DRY AIR WORKS IN FOR LATE SUN THROUGH TUE AS A LOBE OF THE 5H TROUGH EJECTS NORTHEAST...WITH WEAK SUBSIDENCE OVER THE SOUTHEAST. LONGWAVE TROUGH AXIS REMAINS WEST OF THE AREA AND THE DISSIPATING FRONT WILL REMAIN STALLED OVER OR JUST EAST OF THE AREA. THE LACK OF MID LEVEL MOISTURE WILL HINDER DEEPER CONVECTION BUT STILL EXPECT AT LEAST SOME DEVELOPMENT. PLAN TO MAINTAIN INHERITED SILENT POP MON AND TUE GIVEN AN UNFAVORABLE ENVIRONMENT AND A FAIR AMOUNT OF UNCERTAINTY. HIGH TEMPERATURES WILL BE NEAR TO SLIGHTLY BELOW CLIMO DUE TO THE INCREASED MOISTURE/CLOUD COVER ALONG WITH THE POTENTIAL FOR MORE CONVECTION. LOWS WILL CONTINUE TO RUN ABOVE CLIMO. && .AVIATION /17Z WEDNESDAY THROUGH SUNDAY/... AS OF 12Z...TERMINALS ARE VFR THIS MORNING AND VFR WILL LIKELY CONTINUE THROUGH 18Z. WINDS WILL BE SW-W 5-10 KTS EXCEPT BECOMING SSW AT THE COASTAL TERMINALS MID MORNING ON. THUNDERSTORMS RESULTING IN TEMPO REDUCED FLIGHT CONDITIONS AND GUSTY WINDS WILL BE THE BIGGEST THREATS TO AVIATION MAINLY THIS AFTERNOON AND EVENING. THUNDERSTORMS SHOULD DEVELOP AFTER 17Z INITIALLY ALONG A WEAK FRONT NEAR KLBT TO N OF KILM. DRY AIR IN THE MID LEVELS SHOULD ALLOW FOR LESS ACTIVITY TO DEVELOP ELSEWHERE. SOME BOUNDARIES COULD THROWN OFF TO THE SOUTH ALLOWING THUNDERSTORMS TO DEVELOP FURTHER S IN THE AFTERNOON AND EVENING. CONFIDENCE OF THUNDERSTORM OCCURRENCE IS HIGHEST N. ACTIVITY DISSIPATES DURING THE EVENING. WINDS MAY BE VARIABLE IN THE EVENING/EARLY MORNING WHERE STORMS HAVE OCCURRED...BUT GENERALLY LIGHT SW WINDS CAN BE EXPECTED OVERNIGHT WITH VFR CONDITIONS. EXTENDED OUTLOOK...ISOLATED SHOWERS AND STORMS THURSDAY. MODERATE CONFIDENCE FOR SCATTERED TO NUMEROUS SHOWERS AND STORMS FRIDAY AFTERNOON THROUGH SUNDAY WITH MVFR/IFR CONDITIONS AND POSSIBLE HEAVY RAIN. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 200 PM WEDNESDAY...WINDS WILL REMAIN OUT OF THE SW BETWEEN ATLANTIC HIGH PRESSURE AND TROUGH INLAND. SHOULD REMAIN BETWEEN 10 AND 15 KTS OVER MOST OF THE WATERS...BUT WILL SEE SOME HIGHER GUSTS OVER 20 KTS. SEAS WILL BE 2 TO 4 FT WITH THE SW WIND CHOP DOMINATING. WINDS WILL SPIKE UP AND REMAIN GUSTIER THROUGH EARLY THIS EVENING AS SEA BREEZE ENHANCES THE FLOW. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...BERMUDA HIGH AND PIEDMONT TROUGH COMBO WILL MAINTAIN SOUTHWEST FLOW ACROSS THE WATERS THROUGH THE PERIOD. GRADIENT WILL INCREASE THU INTO FRI WITH SOLID 20 KT DEVELOPING THU NIGHT AND CONTINUING THROUGH THE END OF THE PERIOD. SEAS 3 TO 4 FT AT THE START OF THE PERIOD WILL BUILD TO 3 TO 5 FT AND POSSIBLY 4 TO 6 FT FRI AND FRI NIGHT. HEADLINES MAY BE REQUIRED FOR THE SECOND HALF OF THE PERIOD. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 AM WEDNESDAY...BERMUDA HIGH COMBINED WITH LOW PRESSURE ROTATING THROUGH THE MID ATLANTIC AND THE APPROACH OF THE ASSOCIATED COLD FRONT WILL PINCH THE SURFACE GRADIENT SAT INTO SUN. SOUTHWEST FLOW WILL REMAIN 15 TO 20 KT THOUGH THE PERIOD. FRONT IS NOT EXPECTED TO MOVE OVER THE WATERS BUT INSTEAD REMAIN STALLED INLAND. THIS WILL KEEP WINDS OUT OF THE SOUTHWEST THROUGH SUN. SEAS WILL RUN 3 TO 5 FT BUT GIVEN THE EXTENDED PERIOD OF WINDS AROUND 20 KT CANNOT RULE OUT SOME 6 FT SEAS...ESPECIALLY WATERS NEAR 20 NM OPEN TO SOUTHWEST FETCH AND HEADLINES COULD BE REQUIRED FOR AT LEAST A PORTION OF THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SCZ017-023-024- 032-033-039-053>056. HEAT ADVISORY FROM 10 AM TO 8 PM EDT THURSDAY FOR SCZ017-023- 024-032-033-039-053>056. NC...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NCZ087-096-099- 105>110. HEAT ADVISORY FROM 10 AM TO 8 PM EDT THURSDAY FOR NCZ087-096- 099-105>110. MARINE...NONE. && $$ NEAR TERM...RGZ SHORT TERM...III LONG TERM...III AVIATION...RGZ/MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
130 PM EDT WED JUN 24 2015 .SYNOPSIS... HOT AND HUMID CONDITIONS WILL PERSIST THROUGH THE END OF THE WEEK WITH ISOLATED SHOWERS AND THUNDERSTORMS PRIMARILY EACH AFTERNOON AND EVENING. COOLER TEMPERATURES ALONG WITH A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS WEEKEND. A DRYING TREND WILL BEGIN NEXT WEEK AS FRONT STALLED IN THE AREA DISSIPATES AND HIGH PRESSURE RETURNS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 10 AM WEDNESDAY...A HEAT ADVISORY REMAINS IN EFFECT THROUGH EARLY THIS EVENING AS TEMPS SOAR INTO AND THROUGH THE 90S ONCE AGAIN AND COMBINE WITH A VERY HUMID AIR MASS TO CREATE DANGEROUS HEAT. A COLD FRONT EXTENDING FROM THE MOUNTAINS OF WESTERN NC E-NE TOWARD NC/VA COAST THIS MORNING WILL PUSH ONLY SLOWLY SOUTH AS IT WASHES OUT. THIS WILL HELP TO ADVECT SLIGHTLY DRIER AIR IN FROM THE N-NW AND WILL CREATE A TIGHTER GRADIENT FLOW PRODUCING ENHANCED LOW LEVEL CONVERGENCE ALONG TROUGH AHEAD OF IT. OVERALL IT WILL JUST PRODUCE A WIND SHIFT TO A MORE N-NE DIRECTION BEHIND IT AS IT REACHES DOWN ALONG THE NC/SC BORDER CUTTING ACROSS OUR LOCAL FORECAST AREA THIS AFTERNOON. THE MUCH LOWER DEWPOINT AIR WILL REMAIN WELL TO THE NORTH AS SW FLOW AT THE SURFACE CONTINUES TO KEEP A MOISTURE RICH AIR MASS OVER MUCH OF LOCAL FORECAST AREA....WITH DEWPOINT TEMPS INTO THE 70S THIS MORNING AND PCP WATER VALUES NEAR 2 INCHES. ML CAPE VALUES WERE REACHING CLOSE TO 4000 J/KG WITH LI VALUES TO -11. THIS UNSTABLE ENVIRONMENT WILL INCREASE THE POTENTIAL FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON. OVERALL THE FORCING WILL BE SHALLOW WITH STEEP LOW LEVEL LAPSE RATES TO INITIATE STORM DEVELOPMENT THIS AFTERNOON. THE FOCUS OF CONVECTION WILL BE ALONG THIS SFC BOUNDARY AS IT SHIFTS SLIGHTLY SOUTH THROUGH THIS AFTERNOON AND COMBINES WITH ENHANCED CONVERGENCE ALONG SEA BREEZE BOUNDARY AS IT ADVANCES INLAND AND OTHER LOCALIZED BOUNDARIES. WITH ALL THIS BEING SAID...THERE IS NOT MUCH IN THE WAY OF UPPER LEVEL SUPPORT AS WE REMAIN ON THE TOP OF RIDGE ALOFT. THE SW FLOW FROM THE SFC THROUGH THE LOW LEVEL FLOW WILL VEER TO BECOME MORE WESTERLY WHICH WILL AID IN DOWNSLOPE FLOW AND HEATING...SOME DRYING AND WILL ALSO HELP TO KEEP SEA BREEZE PINNED CLOSER TO THE COAST INITIALLY. AS HEATING INCREASES EXPECT CU AND SHWRS/TSTMS TO FORM ALONG CONVERGENT BOUNDARIES. SPC HAS KEPT OUR AREA IN A MARGINAL RISK FOR SVR STORMS AS A MODERATELY UNSTABLE AIR MASS YIELDS STRONG UPDRAFT/DOWNDRAFT GROWTH WITH POTENTIAL FOR ISOLATED DAMAGING WINDS. THE HRRR SHOWS MAIN FOCUS ALONG WEAKENING FRONT FROM MARLBORO TO PENDER COUNTIES BY 18Z AND OTHER MORE ISOLATED CONVECTIVE DEVELOPMENT ALONG SEA BREEZE FROM GEORGETOWN COUNTY UP THROUGH THE GRAND STRAND INTO THE CAPE FEAR AREA. THE STEERING FLOW WILL BE OUT OF THE NW WHICH WILL PUSH ALL STORMS SOUTHEAST AND TOWARD THE COAST WITH OTHER STORMS DEVELOPING ALONG COLLIDING BOUNDARIES. MOST OF THIS ACTIVITY WILL END THIS EVENING AS CONVECTION WILL BE ALMOST EXCLUSIVELY DIURNALLY FORCED. MIN TEMPS TONIGHT WILL AGAIN BE QUITE WARM...DROPPING ONLY TO AROUND 80 AT THE BEACHES...75 WELL INLAND. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 130 PM WEDNESDAY...HOT/HUMID SOUTHWESTERLY FLOW WILL CONTINUE THURSDAY AND FRIDAY NIGHT WHILE MID/UPPER RIDGE MAINTAINS ITS PRESENCE FOR A COUPLE MORE DAYS. THE HEAT INDEX IS PROJECTED TO SURPASS HEAT ADVISORY CRITERIA THURSDAY AND WILL LIKELY DO SO AGAIN ON FRIDAY. THE SOUTHWESTERLY FLOW WILL ALSO SUPPORT ABOVE NORMAL MIN TEMPERATURES EACH NIGHT WITH LOWS IN THE MID TO UPPER 70S. HIGHS EACH DAY ARE EXPECTED TO RANGE FROM THE LOWER 90S AT THE COAST TO THE UPPER 90S TO AROUND 100. ALTHOUGH THE BETTER CHANCES FOR SHOWERS/TSTMS EXISTS IN THE EXTENDED A CHANCE EXISTS PRIMARILY FOR EACH AFTERNOON AND EVENING WITH THE SEA BREEZE AS A TRIGGER. PLENTY OF INSTABILITY EXISTS SO ANY STORM THAT DOES FIRE COULD BE STRONG. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 130 PM WEDNESDAY...A LONG WAVE TROUGH WILL DEVELOP OVER THE GREAT LAKES BY SATURDAY AND BRING SOME RELIEF FROM THE EXTENDED HEAT WAVE OF THE LAST COUPLE OF WEEKS. SOUTHWEST FLOW EAST OF THE TROUGH AXIS WILL RESULT IN A SURGE OF GULF MOISTURE AND UNSETTLED WEATHER SATURDAY INTO EARLY SUNDAY. CONVECTION WILL COME TO AN END AS A COLD FRONT MOVES OFF THE COAST BY SUNDAY MORNING...AND SURFACE HIGH PRESSURE SHOULD BRING TEMPERATURES DOWN TO AROUND CLIMO FOR MONDAY. RETURN FLOW WILL SET UP TUESDAY AND CONTINUE WEDNESDAY BUT THE LACK OF DEEP MOISTURE WILL KEEP CONVECTION SCATTERED AT BEST. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AS OF 1730Z...TERMINALS ARE VFR THIS AFTERNOON. WINDS ARE LIGHT AND VARIABLE AT KFLO/KLBT SSW-W AT THE COASTAL TERMINALS. THUNDERSTORMS RESULTING IN TEMPO REDUCED FLIGHT CONDITIONS AND GUSTY WINDS WILL BE THE BIGGEST THREATS TO AVIATION MAINLY THIS AFTERNOON AND EVENING. MOSTLY ISOLATED THUNDERSTORMS WILL DEVELOP ALONG A WEAK TROUGH AHEAD OF A WEAK COLD FRONT FROM KLBT TO N OF KILM. BEST CONFIDENCE OF OCCURRENCE WILL BE AT KILM WITH TROUGH/SEA BREEZE BOUNDARY INTERACTIONS. SOME OUTFLOW BOUNDARIES COULD BE THROWN OFF TO THE SOUTH ALLOWING THUNDERSTORMS TO RE-DEVELOP FURTHER S TOWARDS THE SOUTHERN TERMINALS LATER THIS AFTERNOON AND EVENING...BUT ACTIVITY SHOULD BE WEAKER AND EVEN ISOLATED. ACTIVITY DISSIPATES DURING THE EVENING WITH LOSS OF HEATING. WINDS MAY BE VARIABLE IN THE EVENING/EARLY MORNING WHERE STORMS HAVE OCCURRED...BUT GENERALLY WILL RECOVER TO LIGHT SW FOR THE OVERNIGHT WITH VFR CONDITIONS. VFR CONTINUES AFTER SUNRISE WITH LIGHT SW WINDS CONTINUING. EXTENDED OUTLOOK...ISOLATED SHOWERS AND STORMS THURSDAY. MODERATE CONFIDENCE FOR SCATTERED TO NUMEROUS SHOWERS AND STORMS FRIDAY AFTERNOON THROUGH SUNDAY WITH MVFR/IFR CONDITIONS AND POSSIBLE HEAVY RAIN. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 12 PM WEDNESDAY...WINDS WILL REMAIN OUT OF THE SW 10 TO 15 KTS BETWEEN ATLANTIC HIGH PRESSURE AND TROUGH INLAND. SEAS WILL BE 2 TO 4 FT WITH THE SW WIND CHOP DOMINATING. WINDS WILL SPIKE UP AND BE GUSTY THROUGH THIS AFTERNOON AS SEA BREEZE ENHANCES THE FLOW. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 130 PM WEDNESDAY...THE SOUTHWEST PRESSURE GRADIENT WILL PERSIST BETWEEN INLAND TROUGH OF LOW PRESSURE AND HIGH PRESSURE OFF THE SOUTHEAST UNITED STATES COAST EACH DAY. THE GRADIENT WILL TIGHTEN BY THURSDAY AFTERNOON AND BREEZY SOUTHWEST FLOW WILL CARRY INTO FRIDAY. WAVE GUIDANCE INDICATES THAT A 1-2 FT SOUTHEAST SWELL WILL REMAIN MASKED BY THE MORE DOMINANT LOWER PERIOD WAVES AS A RESULT OF THE SOUTHWESTERLY FETCH. THUS NOT THE BEST OF BOATING FOR THE COASTAL WATERS WITH SOME STEEP CONDITIONS POSSIBLE. LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 130 PM WEDNESDAY...SOUTHWEST FLOW WILL INCREASE SATURDAY WITH A TIGHTENING GRADIENT AHEAD OF A COLD FRONT. SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE SATURDAY INTO EARLY SUNDAY AS WINDS SPEEDS ARE EXPECTED TO REACH 20-25 KTS. THE GRADIENT WILL RELAX WITH THE APPROACH FROM THE WEST OF THE SURFACE TROUGH AND ASSOCIATED COLD FRONT. SCATTERED TO NUMEROUS SHOWERS AND TSTMS AHEAD OF THE FRONT WILL DIMINISH ON SUNDAY...AND WINDS ARE EXPECTED TO SHIFT TO THE NORTHEAST SUNDAY NIGHT AS HIGH PRESSURE BUILDS OVER THE WATERS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SCZ017-023-024- 032-033-039-053>056. HEAT ADVISORY FROM 10 AM TO 8 PM EDT THURSDAY FOR SCZ017-023- 024-032-033-039-053>056. NC...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NCZ087-096-099- 105>110. HEAT ADVISORY FROM 10 AM TO 8 PM EDT THURSDAY FOR NCZ087-096- 099-105>110. MARINE...NONE. && $$ NEAR TERM...RGZ SHORT TERM...SRP LONG TERM...CRM AVIATION...MRR/RGZ
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1212 PM EDT WED JUN 24 2015 .SYNOPSIS... HOT AND HUMID CONDITIONS WILL PERSIST THROUGH THE END OF THE WEEK WITH ISOLATED SHOWERS AND THUNDERSTORMS PRIMARILY DURING THE AFTERNOONS AND EVENINGS. MUCH COOLER TEMPERATURES ALONG WITH A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS WEEKEND. A DRYING TREND WILL BEGIN NEXT WEEK AS FRONT STALLED IN THE AREA DISSIPATES AND HIGH PRESSURE RETURNS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1000 AM WEDNESDAY...A HEAT ADVISORY REMAINS IN EFFECT THROUGH EARLY THIS EVENING AS TEMPS SOAR INTO AND THROUGH THE 90S ONCE AGAIN AND COMBINE WITH A VERY HUMID AIR MASS TO CREATE DANGEROUS HEAT. A COLD FRONT EXTENDING FROM THE MOUNTAINS OF WESTERN NC E-NE TOWARD NC/VA COAST THIS MORNING WILL PUSH ONLY SLOWLY SOUTH AS IT WASHES OUT. THIS WILL HELP TO ADVECT SLIGHTLY DRIER AIR IN FROM THE N-NW AND WILL CREATE A TIGHTER GRADIENT FLOW PRODUCING ENHANCED LOW LEVEL CONVERGENCE ALONG TROUGH AHEAD OF IT. OVERALL IT WILL JUST PRODUCE A WIND SHIFT TO A MORE N-NE DIRECTION BEHIND IT AS IT REACHES DOWN ALONG THE NC/SC BORDER CUTTING ACROSS OUR LOCAL FORECAST AREA THIS AFTERNOON. THE MUCH LOWER DEWPOINT AIR WILL REMAIN WELL TO THE NORTH AS SW FLOW AT THE SURFACE CONTINUES TO KEEP A MOISTURE RICH AIR MASS OVER MUCH OF LOCAL FORECAST AREA....WITH DEWPOINT TEMPS INTO THE 70S THIS MORNING AND PCP WATER VALUES NEAR 2 INCHES. ML CAPE VALUES WERE REACHING CLOSE TO 4000 J/KG WITH LI VALUES TO -11. THIS UNSTABLE ENVIRONMENT WILL INCREASE THE POTENTIAL FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON. OVERALL THE FORCING WILL BE SHALLOW WITH STEEP LOW LEVEL LAPSE RATES TO INITIATE STORM DEVELOPMENT THIS AFTERNOON. THE FOCUS OF CONVECTION WILL BE ALONG THIS SFC BOUNDARY AS IT SHIFTS SLIGHTLY SOUTH THROUGH THIS AFTERNOON AND COMBINES WITH ENHANCED CONVERGENCE ALONG SEA BREEZE BOUNDARY AS IT ADVANCES INLAND AND OTHER LOCALIZED BOUNDARIES. WITH ALL THIS BEING SAID...THERE IS NOT MUCH IN THE WAY OF UPPER LEVEL SUPPORT AS WE REMAIN ON THE TOP OF RIDGE ALOFT. THE SW FLOW FROM THE SFC THROUGH THE LOW LEVEL FLOW WILL VEER TO BECOME MORE WESTERLY WHICH WILL AID IN DOWNSLOPE FLOW AND HEATING...SOME DRYING AND WILL ALSO HELP TO KEEP SEA BREEZE PINNED CLOSER TO THE COAST INITIALLY. AS HEATING INCREASES EXPECT CU AND SHWRS/TSTMS TO FORM ALONG CONVERGENT BOUNDARIES. SPC HAS KEPT OUR AREA IN A MARGINAL RISK FOR SVR STORMS AS A MODERATELY UNSTABLE AIR MASS YIELDS STRONG UPDRAFT/DOWNDRAFT GROWTH WITH POTENTIAL FOR ISOLATED DAMAGING WINDS. THE HRRR SHOWS MAIN FOCUS ALONG WEAKENING FRONT FROM MARLBORO TO PENDER COUNTIES BY 18Z AND OTHER MORE ISOLATED CONVECTIVE DEVELOPMENT ALONG SEA BREEZE FROM GEORGETOWN COUNTY UP THROUGH THE GRAND STRAND INTO THE CAPE FEAR AREA. THE STEERING FLOW WILL BE OUT OF THE NW WHICH WILL PUSH ALL STORMS SOUTHEAST AND TOWARD THE COAST WITH OTHER STORMS DEVELOPING ALONG COLLIDING BOUNDARIES. MOST OF THIS ACTIVITY WILL END THIS EVENING AS CONVECTION WILL BE ALMOST EXCLUSIVELY DIURNALLY FORCED. MIN TEMPS TONIGHT WILL AGAIN BE QUITE WARM...DROPPING ONLY TO AROUND 80 AT THE BEACHES...75 WELL INLAND. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...LONG LIVED MID LEVEL RIDGE WILL START SHOWING SIGNS OF WEAKENING DURING THE PERIOD ALTHOUGH THE HEAT AND HUMIDITY WILL CONTINUE. RIDGE HOLDS ON THU BUT STARTS TO BREAK DOWN LATER FRI AS 5H TROUGH APPROACHES FROM THE NORTHWEST. AT THE SURFACE THE BERMUDA HIGH AND PIEDMONT TROUGH REMAIN IN PLACE ALONG WITH DAILY DEVELOPMENT OF THE AFTERNOON SEA BREEZE. DEEP MOISTURE REMAINS IN PLACE WITH PRECIPITABLE WATER VALUES RUNNING BETWEEN 1.75 AND 2 INCHES. MID LEVEL LAPSE RATES ARE STEEP ENOUGH FOR DEVELOPMENT OF MODERATE TO STRONG UPDRAFTS WITH ONLY A SHALLOW LAYER OF LESS FAVORABLE LAPSE RATES TO OVERCOME. THE PROBLEM IS THE HEIGHT OF THIS SHALLOW STABLE LAYER WHICH IS BASED BETWEEN 7K AND 8K FT. THIS MAY BE TOO HIGH FOR THE SEA BREEZE AND PIEDMONT TROUGH TO OVERCOME ON THEIR OWN. ATMOSPHERE MAY REQUIRE SOME BOUNDARY INTERACTION...WITH LEFT OVER CONVECTIVE BOUNDARIES...AND HEATING BEFORE DEEPER CONVECTION IS ABLE TO DEVELOP. WILL CARRY CHC POP EACH AFTERNOON BUT FAVOR A LATER TIMING GIVEN THE AFOREMENTIONED LIMITATIONS. TEMPERATURES WILL CONTINUE TO RUN WELL ABOVE CLIMO WITH HIGHS IN THE MID 90S AND LOWS IN THE MID TO UPPER 70S. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY...MID LEVEL TROUGH AND STALLED SURFACE BOUNDARY WILL RESULT IN UNSETTLED WEATHER FOR MUCH OF THE PERIOD. LARGE 5H TROUGH SETS UP OVER THE EASTERN CONUS BUT THE TROUGHS AXIS WILL REMAIN WEST OF THE AREA THROUGH TUE. COMBINATION OF DIURNAL HEATING...DEEP AND MOIST SOUTHWEST FLOW...AND AN OCCASIONAL SHORTWAVE ROTATING AROUND THE BASE OF THE TROUGH WILL LEAD TO AN INCREASE IN SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE AREA. BEST CHANCES WILL BE SAT INTO SUN AS THE TROUGH ARRIVES AND PUSHES A COLD FRONT INTO THE AREA. DEEP MOISTURE PRESENT AHEAD OF THE TROUGH ALONG WITH SHORTWAVE ENERGY WARRANTS AT LEAST HIGH CHC TO LIKELY POP SAT. MOISTURE LINGERS THROUGH THE FIRST HALF OF SUN BUT LOW LEVEL INSTABILITY DECREASES. WILL HOLD ONTO PRECIP CHANCES SUN AND SUN NIGHT BUT TREND POP DOWNWARD...ESPECIALLY SUN NIGHT. MID LEVEL DRY AIR WORKS IN FOR LATE SUN THROUGH TUE AS A LOBE OF THE 5H TROUGH EJECTS NORTHEAST...WITH WEAK SUBSIDENCE OVER THE SOUTHEAST. LONGWAVE TROUGH AXIS REMAINS WEST OF THE AREA AND THE DISSIPATING FRONT WILL REMAIN STALLED OVER OR JUST EAST OF THE AREA. THE LACK OF MID LEVEL MOISTURE WILL HINDER DEEPER CONVECTION BUT STILL EXPECT AT LEAST SOME DEVELOPMENT. PLAN TO MAINTAIN INHERITED SILENT POP MON AND TUE GIVEN AN UNFAVORABLE ENVIRONMENT AND A FAIR AMOUNT OF UNCERTAINTY. HIGH TEMPERATURES WILL BE NEAR TO SLIGHTLY BELOW CLIMO DUE TO THE INCREASED MOISTURE/CLOUD COVER ALONG WITH THE POTENTIAL FOR MORE CONVECTION. LOWS WILL CONTINUE TO RUN ABOVE CLIMO. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... AS OF 12Z...TERMINALS ARE VFR THIS MORNING AND VFR WILL LIKELY CONTINUE THROUGH 18Z. WINDS WILL BE SW-W 5-10 KTS EXCEPT BECOMING SSW AT THE COASTAL TERMINALS MID MORNING ON. THUNDERSTORMS RESULTING IN TEMPO REDUCED FLIGHT CONDITIONS AND GUSTY WINDS WILL BE THE BIGGEST THREATS TO AVIATION MAINLY THIS AFTERNOON AND EVENING. THUNDERSTORMS SHOULD DEVELOP AFTER 17Z INITIALLY ALONG A WEAK FRONT NEAR KLBT TO N OF KILM. DRY AIR IN THE MID LEVELS SHOULD ALLOW FOR LESS ACTIVITY TO DEVELOP ELSEWHERE. SOME BOUNDARIES COULD THROWN OFF TO THE SOUTH ALLOWING THUNDERSTORMS TO DEVELOP FURTHER S IN THE AFTERNOON AND EVENING. CONFIDENCE OF THUNDERSTORM OCCURRENCE IS HIGHEST N. ACTIVITY DISSIPATES DURING THE EVENING. WINDS MAY BE VARIABLE IN THE EVENING/EARLY MORNING WHERE STORMS HAVE OCCURRED...BUT GENERALLY LIGHT SW WINDS CAN BE EXPECTED OVERNIGHT WITH VFR CONDITIONS. EXTENDED OUTLOOK...ISOLATED SHOWERS AND STORMS THURSDAY. MODERATE CONFIDENCE FOR SCATTERED TO NUMEROUS SHOWERS AND STORMS FRIDAY AFTERNOON THROUGH SUNDAY WITH MVFR/IFR CONDITIONS AND POSSIBLE HEAVY RAIN. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1200 PM WEDNESDAY...WINDS WILL REMAIN OUT OF THE SW 10 TO 15 KTS BETWEEN ATLANTIC HIGH PRESSURE AND TROUGH INLAND. SEAS WILL BE 2 TO 4 FT WITH THE SW WIND CHOP DOMINATING. WINDS WILL SPIKE UP AND BE GUSTY THROUGH THIS AFTERNOON AS SEA BREEZE ENHANCES THE FLOW. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...BERMUDA HIGH AND PIEDMONT TROUGH COMBO WILL MAINTAIN SOUTHWEST FLOW ACROSS THE WATERS THROUGH THE PERIOD. GRADIENT WILL INCREASE THU INTO FRI WITH SOLID 20 KT DEVELOPING THU NIGHT AND CONTINUING THROUGH THE END OF THE PERIOD. SEAS 3 TO 4 FT AT THE START OF THE PERIOD WILL BUILD TO 3 TO 5 FT AND POSSIBLY 4 TO 6 FT FRI AND FRI NIGHT. HEADLINES MAY BE REQUIRED FOR THE SECOND HALF OF THE PERIOD. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 AM WEDNESDAY...BERMUDA HIGH COMBINED WITH LOW PRESSURE ROTATING THROUGH THE MID ATLANTIC AND THE APPROACH OF THE ASSOCIATED COLD FRONT WILL PINCH THE SURFACE GRADIENT SAT INTO SUN. SOUTHWEST FLOW WILL REMAIN 15 TO 20 KT THOUGH THE PERIOD. FRONT IS NOT EXPECTED TO MOVE OVER THE WATERS BUT INSTEAD REMAIN STALLED INLAND. THIS WILL KEEP WINDS OUT OF THE SOUTHWEST THROUGH SUN. SEAS WILL RUN 3 TO 5 FT BUT GIVEN THE EXTENDED PERIOD OF WINDS AROUND 20 KT CANNOT RULE OUT SOME 6 FT SEAS...ESPECIALLY WATERS NEAR 20 NM OPEN TO SOUTHWEST FETCH AND HEADLINES COULD BE REQUIRED FOR AT LEAST A PORTION OF THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SCZ017-023-024- 032-033-039-053>056. NC...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NCZ087-096-099- 105>110. MARINE...NONE. && $$ NEAR TERM...RGZ SHORT TERM...III LONG TERM...III AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1137 AM EDT WED JUN 24 2015 .SYNOPSIS... HOT AND HUMID CONDITIONS WILL PERSIST THROUGH THE END OF THE WEEK WITH ISOLATED SHOWERS AND THUNDERSTORMS PRIMARILY DURING THE AFTERNOONS AND EVENINGS. MUCH COOLER TEMPERATURES ALONG WITH A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS WEEKEND. A DRYING TREND WILL BEGIN NEXT WEEK AS FRONT STALLED IN THE AREA DISSIPATES AND HIGH PRESSURE RETURNS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1000 AM WEDNESDAY...A HEAT ADVISORY REMAINS IN EFFECT TODAY AS TEMPS SOAR INTO AND THROUGH THE 90S ONCE AGAIN AND COMBINE WITH A VERY HUMID AIR MASS TO CREATE DANGEROUS HEAT. A COLD FRONT EXTENDING FROM THE MOUNTAINS OF WESTERN NC E-NE TOWARD NC/VA COAST THIS MORNING WILL PUSH ONLY SLOWLY SOUTH AS IT WASHES OUT. THIS WILL HELP TO ADVECT SLIGHTLY DRIER AIR IN FROM THE N-NW AND WILL CREATE A TIGHTER GRADIENT FLOW PRODUCING ENHANCED LOW LEVEL CONVERGENCE ALONG TROUGH AHEAD OF IT. OVERALL IT WILL JUST PRODUCE A WIND SHIFT TO A MORE N-NE DIRECTION BEHIND IT AS IT REACHES DOWN ALONG THE NC/SC BORDER CUTTING ACROSS OUR LOCAL FORECAST AREA THIS AFTERNOON. THE MUCH LOWER DEWPOINT AIR WILL REMAIN WELL TO THE NORTH AS SW FLOW AT THE SURFACE CONTINUES TO KEEP A MOISTURE RICH AIR MASS OVER MUCH OF LOCAL FORECAST AREA....WITH DEWPOINT TEMPS INTO THE 70S THIS MORNING AND PCP WATER VALUES NEAR 2 INCHES. ML CAPE VALUES WERE REACHING CLOSE TO 4000 J/KG WITH LI VALUES TO -11. THIS UNSTABLE ENVIRONMENT WILL INCREASE THE POTENTIAL FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON. OVERALL THE FORCING WILL BE SHALLOW WITH STEEP LOW LEVEL LAPSE RATES TO INITIATE STORM DEVELOPMENT THIS AFTERNOON. THE FOCUS OF CONVECTION WILL BE ALONG THIS SFC BOUNDARY AS IT SHIFTS SLIGHTLY SOUTH THROUGH THIS AFTERNOON AND COMBINES WITH ENHANCED CONVERGENCE ALONG SEA BREEZE BOUNDARY AS IT ADVANCES INLAND AND OTHER LOCALIZED BOUNDARIES. WITH ALL THIS BEING SAID...THERE IS NOT MUCH IN THE WAY OF UPPER LEVEL SUPPORT AS WE REMAIN ON THE TOP OF RIDGE ALOFT. THE SW FLOW FROM THE SFC THROUGH THE LOW LEVEL FLOW WILL VEER TO BECOME MORE WESTERLY WHICH WILL AID IN DOWNSLOPE FLOW AND HEATING...SOME DRYING AND WILL ALSO HELP TO KEEP SEA BREEZE PINNED CLOSER TO THE COAST INITIALLY. AS HEATING INCREASES EXPECT CU AND SHWRS/TSTMS TO FORM ALONG CONVERGENT BOUNDARIES. SPC HAS KEPT OUR AREA IN A MARGINAL RISK FOR SVR STORMS AS A MODERATELY UNSTABLE AIR MASS YIELDS STRONG UPDRAFT/DOWNDRAFT GROWTH WITH POTENTIAL FOR ISOLATED DAMAGING WINDS. THE HRRR SHOWS MAIN FOCUS ALONG WEAKENING FRONT FROM MARLBORO TO PENDER COUNTIES BY 18Z AND OTHER MORE ISOLATED CONVECTIVE DEVELOPMENT ALONG SEA BREEZE FROM GEORGETOWN COUNTY UP THROUGH THE GRAND STRAND INTO THE CAPE FEAR AREA. THE STEERING FLOW WILL BE OUT OF THE NW WHICH WILL PUSH ALL STORMS SOUTHEAST AND TOWARD THE COAST WITH OTHER STORMS DEVELOPING ALONG COLLIDING BOUNDARIES. MOST OF THIS ACTIVITY WILL END THIS EVENING AS CONVECTION WILL BE ALMOST EXCLUSIVELY DIURNALLY FORCED. MIN TEMPS TONIGHT WILL AGAIN BE QUITE WARM...DROPPING ONLY TO AROUND 80 AT THE BEACHES...75 WELL INLAND. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...LONG LIVED MID LEVEL RIDGE WILL START SHOWING SIGNS OF WEAKENING DURING THE PERIOD ALTHOUGH THE HEAT AND HUMIDITY WILL CONTINUE. RIDGE HOLDS ON THU BUT STARTS TO BREAK DOWN LATER FRI AS 5H TROUGH APPROACHES FROM THE NORTHWEST. AT THE SURFACE THE BERMUDA HIGH AND PIEDMONT TROUGH REMAIN IN PLACE ALONG WITH DAILY DEVELOPMENT OF THE AFTERNOON SEA BREEZE. DEEP MOISTURE REMAINS IN PLACE WITH PRECIPITABLE WATER VALUES RUNNING BETWEEN 1.75 AND 2 INCHES. MID LEVEL LAPSE RATES ARE STEEP ENOUGH FOR DEVELOPMENT OF MODERATE TO STRONG UPDRAFTS WITH ONLY A SHALLOW LAYER OF LESS FAVORABLE LAPSE RATES TO OVERCOME. THE PROBLEM IS THE HEIGHT OF THIS SHALLOW STABLE LAYER WHICH IS BASED BETWEEN 7K AND 8K FT. THIS MAY BE TOO HIGH FOR THE SEA BREEZE AND PIEDMONT TROUGH TO OVERCOME ON THEIR OWN. ATMOSPHERE MAY REQUIRE SOME BOUNDARY INTERACTION...WITH LEFT OVER CONVECTIVE BOUNDARIES...AND HEATING BEFORE DEEPER CONVECTION IS ABLE TO DEVELOP. WILL CARRY CHC POP EACH AFTERNOON BUT FAVOR A LATER TIMING GIVEN THE AFOREMENTIONED LIMITATIONS. TEMPERATURES WILL CONTINUE TO RUN WELL ABOVE CLIMO WITH HIGHS IN THE MID 90S AND LOWS IN THE MID TO UPPER 70S. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY...MID LEVEL TROUGH AND STALLED SURFACE BOUNDARY WILL RESULT IN UNSETTLED WEATHER FOR MUCH OF THE PERIOD. LARGE 5H TROUGH SETS UP OVER THE EASTERN CONUS BUT THE TROUGHS AXIS WILL REMAIN WEST OF THE AREA THROUGH TUE. COMBINATION OF DIURNAL HEATING...DEEP AND MOIST SOUTHWEST FLOW...AND AN OCCASIONAL SHORTWAVE ROTATING AROUND THE BASE OF THE TROUGH WILL LEAD TO AN INCREASE IN SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE AREA. BEST CHANCES WILL BE SAT INTO SUN AS THE TROUGH ARRIVES AND PUSHES A COLD FRONT INTO THE AREA. DEEP MOISTURE PRESENT AHEAD OF THE TROUGH ALONG WITH SHORTWAVE ENERGY WARRANTS AT LEAST HIGH CHC TO LIKELY POP SAT. MOISTURE LINGERS THROUGH THE FIRST HALF OF SUN BUT LOW LEVEL INSTABILITY DECREASES. WILL HOLD ONTO PRECIP CHANCES SUN AND SUN NIGHT BUT TREND POP DOWNWARD...ESPECIALLY SUN NIGHT. MID LEVEL DRY AIR WORKS IN FOR LATE SUN THROUGH TUE AS A LOBE OF THE 5H TROUGH EJECTS NORTHEAST...WITH WEAK SUBSIDENCE OVER THE SOUTHEAST. LONGWAVE TROUGH AXIS REMAINS WEST OF THE AREA AND THE DISSIPATING FRONT WILL REMAIN STALLED OVER OR JUST EAST OF THE AREA. THE LACK OF MID LEVEL MOISTURE WILL HINDER DEEPER CONVECTION BUT STILL EXPECT AT LEAST SOME DEVELOPMENT. PLAN TO MAINTAIN INHERITED SILENT POP MON AND TUE GIVEN AN UNFAVORABLE ENVIRONMENT AND A FAIR AMOUNT OF UNCERTAINTY. HIGH TEMPERATURES WILL BE NEAR TO SLIGHTLY BELOW CLIMO DUE TO THE INCREASED MOISTURE/CLOUD COVER ALONG WITH THE POTENTIAL FOR MORE CONVECTION. LOWS WILL CONTINUE TO RUN ABOVE CLIMO. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AS OF 12Z...TERMINALS ARE VFR THIS MORNING AND VFR WILL LIKELY CONTINUE THROUGH 18Z. WINDS WILL BE SW-W 5-10 KTS EXCEPT BECOMING SSW AT THE COASTAL TERMINALS MID MORNING ON. THUNDERSTORMS RESULTING IN TEMPO REDUCED FLIGHT CONDITIONS AND GUSTY WINDS WILL BE THE BIGGEST THREATS TO AVIATION MAINLY THIS AFTERNOON AND EVENING. THUNDERSTORMS SHOULD DEVELOP AFTER 17Z INITIALLY ALONG A WEAK FRONT NEAR KLBT TO N OF KILM. DRY AIR IN THE MID LEVELS SHOULD ALLOW FOR LESS ACTIVITY TO DEVELOP ELSEWHERE. SOME BOUNDARIES COULD THROWN OFF TO THE SOUTH ALLOWING THUNDERSTORMS TO DEVELOP FURTHER S IN THE AFTERNOON AND EVENING. CONFIDENCE OF THUNDERSTORM OCCURRENCE IS HIGHEST N. ACTIVITY DISSIPATES DURING THE EVENING. WINDS MAY BE VARIABLE IN THE EVENING/EARLY MORNING WHERE STORMS HAVE OCCURRED...BUT GENERALLY LIGHT SW WINDS CAN BE EXPECTED OVERNIGHT WITH VFR CONDITIONS. EXTENDED OUTLOOK...ISOLATED SHOWERS AND STORMS THURSDAY. MODERATE CONFIDENCE FOR SCATTERED TO NUMEROUS SHOWERS AND STORMS FRIDAY AFTERNOON THROUGH SUNDAY WITH MVFR/IFR CONDITIONS AND POSSIBLE HEAVY RAIN. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1000 AM WEDNESDAY...A SCEC REMAINS IN EFFECT UNTIL NOON AS MODERATE SW WINDS CONTINUED. CONDITIONS WILL IMPROVE AS WINDS DIMINISH. WINDS AND SEAS WILL EASE THIS AFTN AS THE LLJ WEAKENS AND THE OVERALL GRADIENT RELAXES A BIT. WINDS WILL REMAIN FROM THE SW THROUGH TODAY...BUT FALL TO AROUND 15 KTS...AND SEAS WILL DROP IN TANDEM TO 3-4 FT WITH THE SW WIND CHOP DOMINATING THE SPECTRUM. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...BERMUDA HIGH AND PIEDMONT TROUGH COMBO WILL MAINTAIN SOUTHWEST FLOW ACROSS THE WATERS THROUGH THE PERIOD. GRADIENT WILL INCREASE THU INTO FRI WITH SOLID 20 KT DEVELOPING THU NIGHT AND CONTINUING THROUGH THE END OF THE PERIOD. SEAS 3 TO 4 FT AT THE START OF THE PERIOD WILL BUILD TO 3 TO 5 FT AND POSSIBLY 4 TO 6 FT FRI AND FRI NIGHT. HEADLINES MAY BE REQUIRED FOR THE SECOND HALF OF THE PERIOD. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 AM WEDNESDAY...BERMUDA HIGH COMBINED WITH LOW PRESSURE ROTATING THROUGH THE MID ATLANTIC AND THE APPROACH OF THE ASSOCIATED COLD FRONT WILL PINCH THE SURFACE GRADIENT SAT INTO SUN. SOUTHWEST FLOW WILL REMAIN 15 TO 20 KT THOUGH THE PERIOD. FRONT IS NOT EXPECTED TO MOVE OVER THE WATERS BUT INSTEAD REMAIN STALLED INLAND. THIS WILL KEEP WINDS OUT OF THE SOUTHWEST THROUGH SUN. SEAS WILL RUN 3 TO 5 FT BUT GIVEN THE EXTENDED PERIOD OF WINDS AROUND 20 KT CANNOT RULE OUT SOME 6 FT SEAS...ESPECIALLY WATERS NEAR 20 NM OPEN TO SOUTHWEST FETCH AND HEADLINES COULD BE REQUIRED FOR AT LEAST A PORTION OF THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SCZ017-023-024- 032-033-039-053>056. NC...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NCZ087-096-099- 105>110. MARINE...NONE. && $$ NEAR TERM...RGZ SHORT TERM...III LONG TERM...III AVIATION...MRR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
107 PM CDT WED JUN 24 2015 .UPDATE... ISSUED AT 1253 PM CDT WED JUN 24 2015 AS THE FOCUS BEGINS TO SHIFT TO THE NEXT ROUND OF SHOWERS AND THUNDERSTORMS...TIMING ONCE AGAIN NEEDED ADJUSTMENT ON THE BROKEN LINE OF SHOWERS AND THUNDERSTORMS MOVING THROUGH THE U.S. 83 CORRIDOR. UPDATE ISSUED AT 940 AM CDT WED JUN 24 2015 THE LATEST RADAR INDICATES CONVECTION IS MOVING FASTER THAN A CONSENSUS OF THE LAST THREE HRRR RUNS. PRECIPITATION CHANCES WERE UPDATED TO DO A BETTER JOB OF INDICATING THE MOST LIKELY TIMES FOR PRECIPITATION AS A MID LEVEL SHORTWAVE RACES ACROSS THE STATE TODAY. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL COMMENCE AS THE NEXT IN A LONG TRAIN OF SHORTWAVES MOVES FROM WESTERN MONTANA INTO THE DAKOTAS AFTER MIDNIGHT TONIGHT...SO THAT WILL BE THE SHORT TERM FOCUS FOR LATER FORECAST UPDATES. UPDATE ISSUED AT 618 AM CDT WED JUN 24 2015 APPROACHING SHORT WAVE IS BRINGING SCATTERED SHOWERS/THUNDERSTORMS ACROSS EASTERN MONTANA NUDGING INTO NORTHWEST NORTH DAKOTA. HAVE ADJUSTED POPS A BIT TO ACCOUNT FOR THIS. HAVE ALSO ADJUSTED CLOUD COVER WITH THE APPROACHING STORMS AND TO ACCOUNT FOR CLOUDS STREAMING OFF THE ONGOING CONVECTION OVER SOUTHWEST/SOUTH CENTRAL SOUTH DAKOTA. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 333 AM CDT WED JUN 24 2015 THUNDERSTORMS ONCE AGAIN HIGHLIGHT THE SHORT TERM. WITH PERSISTENT ZONAL FLOW AND UPPER LEVEL JET PARKED OVER THE REGION...AND LEE CYCLOGENESIS...DIURNAL THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE. SHORT TERM MODELS INDICATE THUNDERSTORM DEVELOPMENT ACROSS EASTERN MONTANA AND WESTERN NORTH DAKOTA LATE THIS MORNING INTO THE EARLY AFTERNOON HOURS...SPREADING ACROSS CENTRAL NORTH DAKOTA LATE IN THE AFTERNOON AND EVENING HOURS. A MOIST AND UNSTABLE BOUNDARY LAYER REMAINS ACROSS THE NORTHERN PLAINS. WITH SOUTHERLY FLOW AT THE SURFACE AND STRONG WESTERLIES ALOFT...SHEAR WILL CONTINUE TO BE VERY STRONG. SPC HAS NORTH DAKOTA IN A MARGINAL RISK FOR SEVERE STORMS TODAY. WITH PERSISTENT CAPE GREATER THAN 1K J/KG AND SHEAR GREATER THAN 50 KNOTS...ANY STORMS THAT DO FORM COULD QUICKLY BECOME SUPERCELLULAR WITH THE THREAT FOR DAMAGING WIND AND HAIL. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 333 AM CDT WED JUN 24 2015 HIGHLIGHT IN THE LONG TERM WILL BE DIMINISHING THUNDERSTORM CHANCES GOING INTO THE WEEKEND ALONG WITH A WARMING TREND. WEST/NORTHWEST FLOW CONTINUES ON THURSDAY WHILE UPPER RIDGE OVER THE WESTERN CONUS STARTS TO GRADUALLY INTENSIFY. VARIETY OF WEAK DISTURBANCES CONTINUE TO MOVE THROUGH THE FLOW BRINGING THUNDERSTORM CHANCES. MODEST SHEAR/INSTABILITY OVER MOST OF THE AREA WILL KEEP SEVERE THREAT ON THE LOW SIDE...THOUGH OVER THE SOUTHWEST 0-6 KM BULK SHEAR WILL APPROACH 40KTS WITH CAPE VALUES ~1-1.5 KJ/KG WILL BRING A MARGINAL SEVERE THREAT. FOR FRIDAY RIDGE CONTINUES TO AMPLIFY WITH UPPER FLOW SHIFTING MORE NORTHWESTERLY...THOUGH A FEW WEAK WAVES MOVING THROUGH MAY BRING A FEW THUNDERSTORMS TO THE AREA. FOR THE WEEKEND...RIDGE CONTINUES TO AMPLIFY. THIS WILL BRING DRY CONDITIONS OVER OUR WEST...WITH POSSIBLY A FEW STORMS TOWARDS THE EAST AS A FEW WEAK WAVES MOVE THROUGH. TEMPERATURES WILL WARM TO ABOVE AVERAGE. WARM TEMPERATURES CONTINUE INTO EARLY NEXT WEEK WITH OCCASIONAL LOW THUNDERSTORMS CHANCES AS A FEW WEAK WAVES MOVE THROUGH NORTHWESTERLY UPPER LEVEL FLOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1253 PM CDT WED JUN 24 2015 A BROKEN LINE OF CONVECTION STRETCHING FROM KMOT TO KBIS WILL PROGRESS EAST TO KJMS TODAY. A SECOND ROUND OF SHOWERS AND THUNDERSTORMS ARE FORECAST FOR TONIGHT...WITH LOW CONFIDENCE ON TIMING IN TAFS INDICATED BY VCTS AT KBIS/KISN/KDIK. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SCHECK SHORT TERM...AJ LONG TERM...JJS AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
956 AM CDT WED JUN 24 2015 .UPDATE... ISSUED AT 940 AM CDT WED JUN 24 2015 THE LATEST RADAR INDICATES CONVECTION IS MOVING FASTER THAN A CONSENSUS OF THE LAST THREE HRRR RUNS. PRECIPITATION CHANCES WERE UPDATED TO DO A BETTER JOB OF INDICATING THE MOST LIKELY TIMES FOR PRECIPITATION AS A MID LEVEL SHORTWAVE RACES ACROSS THE STATE TODAY. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL COMMENCE AS THE NEXT IN A LONG TRAIN OF SHORTWAVES MOVES FROM WESTERN MONTANA INTO THE DAKOTAS AFTER MIDNIGHT TONIGHT...SO THAT WILL BE THE SHORT TERM FOCUS FOR LATER FORECAST UPDATES. UPDATE ISSUED AT 618 AM CDT WED JUN 24 2015 APPROACHING SHORT WAVE IS BRINGING SCATTERED SHOWERS/THUNDERSTORMS ACROSS EASTERN MONTANA NUDGING INTO NORTHWEST NORTH DAKOTA. HAVE ADJUSTED POPS A BIT TO ACCOUNT FOR THIS. HAVE ALSO ADJUSTED CLOUD COVER WITH THE APPROACHING STORMS AND TO ACCOUNT FOR CLOUDS STREAMING OFF THE ONGOING CONVECTION OVER SOUTHWEST/SOUTH CENTRAL SOUTH DAKOTA. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 333 AM CDT WED JUN 24 2015 THUNDERSTORMS ONCE AGAIN HIGHLIGHT THE SHORT TERM. WITH PERSISTENT ZONAL FLOW AND UPPER LEVEL JET PARKED OVER THE REGION...AND LEE CYCLOGENESIS...DIURNAL THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE. SHORT TERM MODELS INDICATE THUNDERSTORM DEVELOPMENT ACROSS EASTERN MONTANA AND WESTERN NORTH DAKOTA LATE THIS MORNING INTO THE EARLY AFTERNOON HOURS...SPREADING ACROSS CENTRAL NORTH DAKOTA LATE IN THE AFTERNOON AND EVENING HOURS. A MOIST AND UNSTABLE BOUNDARY LAYER REMAINS ACROSS THE NORTHERN PLAINS. WITH SOUTHERLY FLOW AT THE SURFACE AND STRONG WESTERLIES ALOFT...SHEAR WILL CONTINUE TO BE VERY STRONG. SPC HAS NORTH DAKOTA IN A MARGINAL RISK FOR SEVERE STORMS TODAY. WITH PERSISTENT CAPE GREATER THAN 1K J/KG AND SHEAR GREATER THAN 50 KNOTS...ANY STORMS THAT DO FORM COULD QUICKLY BECOME SUPERCELLULAR WITH THE THREAT FOR DAMAGING WIND AND HAIL. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 333 AM CDT WED JUN 24 2015 HIGHLIGHT IN THE LONG TERM WILL BE DIMINISHING THUNDERSTORM CHANCES GOING INTO THE WEEKEND ALONG WITH A WARMING TREND. WEST/NORTHWEST FLOW CONTINUES ON THURSDAY WHILE UPPER RIDGE OVER THE WESTERN CONUS STARTS TO GRADUALLY INTENSIFY. VARIETY OF WEAK DISTURBANCES CONTINUE TO MOVE THROUGH THE FLOW BRINGING THUNDERSTORM CHANCES. MODEST SHEAR/INSTABILITY OVER MOST OF THE AREA WILL KEEP SEVERE THREAT ON THE LOW SIDE...THOUGH OVER THE SOUTHWEST 0-6 KM BULK SHEAR WILL APPROACH 40KTS WITH CAPE VALUES ~1-1.5 KJ/KG WILL BRING A MARGINAL SEVERE THREAT. FOR FRIDAY RIDGE CONTINUES TO AMPLIFY WITH UPPER FLOW SHIFTING MORE NORTHWESTERLY...THOUGH A FEW WEAK WAVES MOVING THROUGH MAY BRING A FEW THUNDERSTORMS TO THE AREA. FOR THE WEEKEND...RIDGE CONTINUES TO AMPLIFY. THIS WILL BRING DRY CONDITIONS OVER OUR WEST...WITH POSSIBLY A FEW STORMS TOWARDS THE EAST AS A FEW WEAK WAVES MOVE THROUGH. TEMPERATURES WILL WARM TO ABOVE AVERAGE. WARM TEMPERATURES CONTINUE INTO EARLY NEXT WEEK WITH OCCASIONAL LOW THUNDERSTORMS CHANCES AS A FEW WEAK WAVES MOVE THROUGH NORTHWESTERLY UPPER LEVEL FLOW. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 618 AM CDT WED JUN 24 2015 ISOLD/SCT TSRA EXPECTED THROUGH TODAY INTO TONIGHT ACROSS WESTERN AND CENTRAL NORTH DAKOTA. OTHERWISE...VFR CONDITIONS WILL PREVAIL. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SCHECK SHORT TERM...AJ LONG TERM...JJS AVIATION...AJ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1220 AM CDT WED JUN 24 2015 .UPDATE... ISSUED AT 1216 AM CDT WED JUN 24 2015 NO MAJOR CHANGES WITH THIS UPDATE. THUNDERSTORMS CONTINUE TO DIMINISH EARLY THIS MORNING. ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED LATER THIS MORNING ACROSS EASTERN MONTANA AND WESTERN NORTH DAKOTA. UPDATE ISSUED AT 937 PM CDT TUE JUN 23 2015 THE CHALLENGE FOR THE REMAINDER OF THE NIGHT IS THE COVERAGE AND INTENSITY OF CONVECTION LATE TONIGHT ACROSS WESTERN AND CENTRAL NORTH DAKOTA FROM THUNDERSTORM ACTIVITY THAT WILL PROPAGATE EAST FROM CENTRAL AND EASTERN MONTANA. THE 01 UTC RAP DEPICTS MULTIPLE IMPULSES EVIDENCED BY ONGOING CONVECTION ACROSS MONTANA PROPAGATING INTO NORTH DAKOTA TONIGHT. 850 MB CAPE VALUES ARE IN THE 500-800 J/KG RANGE WITH STRONG DEEP LAYER SHEAR WITH THE FAST WESTERLIES ALOFT. THUS...SMALL HAIL APPEARS TO BE THE LIKELY THREAT WITH SCATTERED CONVECTION SUSTAINED BY A STRENGTHENING LOW LEVEL JET AND WARM AIR ADVECTION INTO NORTH DAKOTA. UPDATE ISSUED AT 543 PM CDT TUE JUN 23 2015 THE 19-21 UTC HRRR ITERATIONS HAVE A GOOD HANDLE ON THE ONGOING CONVECTION ACROSS WESTERN NORTH DAKOTA...AND WILL USE A BLEND OF THEIR SOLUTIONS FOR SKY COVER AND POPS THROUGH THE EVENING AND OVERNIGHT. A MARGINAL THREAT FOR LARGE HAIL AND DAMAGING WINDS WILL CONTINUE ACROSS SOUTHWEST AND POSSIBLY INTO SOUTH CENTRAL NORTH DAKOTA THROUGH SUNSET. THE 22 UTC RAP ANALYSIS DEPICTS STRONG DEEP LAYER SHEAR OF 40 KTS...WITH ML CAPE VALUES AROUND 1000-1500 J/KG...400 J/KG OF HAIL CAPE AND DOWNDRAFT CAPE AROUND 1000 J/KG. OVERALL...DEEPER MOISTURE APPEARS TO BE A MITIGATING FACTOR FOR GREATER STORM INTENSITY. MULTIPLE FUNNEL CLOUD REPORTS HAVE ALSO BEEN RECEIVED ACROSS THE SOUTHWEST GIVEN THE AT TIMES SUPERCELLUR NATURE OF THE STORMS. HOWEVER...LOW LEVEL KINEMATIC FIELDS ARE NOT OVERLY SUPPORTIVE OF TORNADOES. && .SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY) ISSUED AT 129 PM CDT TUE JUN 23 2015 FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CHANCES FOR THUNDERSTORMS THROUGH THE PERIOD...SOME MARGINALLY SEVERE SOUTHWEST THIS AFTERNOON/EVENING...AND ACROSS WESTERN AND CENTRAL NORTH DAKOTA WEDNESDAY. CURRENTLY...ACTIVE WEST-NORTHWEST FLOW ALOFT WITH A SFC TROUGH STATIONARY ACROSS THE NORTHERN HIGH PLAINS OF MT/WY. UPPER LEVEL DIVERGENCE IN THE EXIT REGION OF AN UPPER LEVEL JET COUPLED WITH DIURNAL INSTABILITY WILL SEE THE CHANCE FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON WEST AND NORTH...THEN SPREADING SLOWLY SOUTHEAST TONIGHT. BEST CHANCE FOR STRONGER STORMS REMAINS ACROSS THE WESTERN THIRD OF THE STATE...MORE SO THE SOUTHWEST WHERE MODELS PORTRAY 800-1200 J/KG OF MUCAPE ALONG WITH 50KTS OF 0-6KM SHEAR. LATEST HRRR ALONG WITH THE 00Z 4KM NSSL WRF INDICATE CONVECTIVE DEVELOPMENT EARLY TO MID AFTERNOON FROM EASTERN MONTANA INTO SOUTHWEST AND WEST CENTRAL NORTH DAKOTA. WILL MAINTAIN HIGH CHANCE SCATTERED POPS FOR THIS AREA. FOR WEDNESDAY...FLOW ALOFT AND UPPER DIVERGENCE REMAINS UNCHANGED OVER THE NORTHERN PLAINS. SFC TROUGH ADVANCES EAST WED MORNING AND AFTERNOON INTO THE CENTRAL DAKOTAS. DAYTIME INSTABILITY AND BULK SHEAR INDICATE CHANCE FOR THUNDERSTORMS AREA WIDE...MARGINALLY SEVERE OVER THE ENTIRE COUNTY WARNING AREA (ALL OF WEST AND CENTRAL ND). WILL MAINTAIN POSSIBLE SEVERE WORDING IN THE HWO. DUE TO THE UNCERTAINTY...OPTED TO NOT INCLUDE IN THE GRIDS AT THIS TIME. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 129 PM CDT TUE JUN 23 2015 CHANCES FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED TO PERSIST INTO WEDNESDAY NIGHT...AS AN UPPER LEVEL SHORTWAVE TROUGH CONTINUES ON AN EASTWARD TRACK OUT OF THE STATE. A TRANSITION FROM QUASI ZONAL FLOW ALOFT INTO NORTHWEST FLOW IS EXPECTED THROUGH THURSDAY. THE CURRENT MODEL PACKAGE PROVIDES GOOD AGREEMENT ON NORTH/NORTHWEST FLOW ALOFT REMAINING IN PLACE THROUGH THE REST OF THE EXTENDED. SEVERAL EMBEDDED MID-LEVEL SHORTWAVES ARE PROJECTED ACROSS THE AREA...RESULTING IN FREQUENT CHANCES FOR ISOLATED/SCATTERED THUNDERSTORMS THOUGH PREDICTABILITY IS LOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1216 AM CDT WED JUN 24 2015 VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH THE PERIOD. THUNDERSTORMS ARE ONCE AGAIN POSSIBLE BEGINNING LATE THIS MORNING AND EARLY THIS AFTERNOON ACROSS WESTERN NORTH DAKOTA AND SPREADING EAST THROUGH THE EVENING. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AJ SHORT TERM...NH LONG TERM...AC AVIATION...AJ
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
658 PM EDT WED JUN 24 2015 .SYNOPSIS... HIGH PRESSURE OVER THE AREA WILL MOVE EAST INTO PENNSYLVANIA BY MORNING. LOW PRESSURE WILL MOVE SLOWLY EAST ACROSS OHIO BY THURSDAY EVENING AND SOUTHEAST OF THE AREA BY FRIDAY. ANOTHER WAVE OF LOW PRESSURE WILL FORM ALONG A STALLED FRONT OVER THE LOWER OHIO VALLEY ON FRIDAY AND TRACK INTO PENNSYLVANIA ON SUNDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... A FAIRLY THICK CIRRUS DECK HAS OVERSPREAD THE AREA AND RAISED CLOUD COVER IN THE FORECAST THROUGH THE EVENING. CLOUDS WILL THIN SOME LATER THIS EVENING AND THEN INCREASE AGAIN OVERNIGHT AS MID-LEVEL MOISTURE ADVECTION ARRIVES. ALSO MADE SOME ADJUSTMENTS TO HIGH TEMPERATURES ON THURDSDAY. ALTHOUGH CAN NOT ENTIRELY RULE OUT THE MORE NORTHERN TRACK OF THE LOW EXHIBITED BY SOME OF THE HIGH RESOLUTION MODELS...THE 18Z SUITE CONTINUES TO FAVOR A MORE SOUTHERN TRACK. LOOKS LIKE OUR SOUTHERN TIER OF COUNTIES HAS A CHANCE OF APPROACHING THE 80 DEGREE MARK BUT THINK IT IS UNLIKELY TO REACH MUCH FARTHER NORTH SO LOWERED HIGHS...ESPECIALLY FROM TOLEDO TO AKRON GIVEN THE EXPECTED CLOUD COVER AND PRECIPITATION. PREVIOUS DISCUSSION... FAIR WEATHER THIS EVENING WILL END AS CLOUDS AND MOISTURE INCREASE AFTER MIDNIGHT AS THE NEXT CONVECTIVE SYSTEM APPROACHES FROM THE WEST. MODEL GUIDANCE IS RATHER CONSISTENT OVERNIGHT IN BRINGING ABOUT A TENTH OF INCH OF QPF INTO THE TOL AREA BY 12Z AS THE NOSE OF A LOW LEVEL JET AND ATTENDANT CONVERGENCE INCREASES TOWARD MORNING. ALL CONVECTION ALLOWING MODELS PRODUCE SIMILAR QPF AND PROGRESSION OF PRECIPITATION INTO NW OHIO. ELSEWHERE FAIR WEATHER CLOUDS WILL DISSIPATE BEFORE SUNSET WITH JUST THICKENING HIGH AND MID CLOUDS. THERE IS A SMALL CHANCE OF SHOWERS TOWARD MORNING MAINLY WEST OF I-71. HAVE USED MAV MEX GUIDANCE FOR OVERNIGHT LOW TEMPERATURES. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/... MORE PRECIPITATION IS EXPECTED IN TWO ROUNDS. ONE ON THURSDAY AND ANOTHER OVER THE WEEKEND. FOR THURSDAY THE HIGH RESOLUTION MODELS TRACK THE SURFACE LOW FARTHER NORTH ACROSS NORTHERN OHIO WHILE THE LARGE SCALE MODELS HAVE IT FARTHER SOUTH. SPC HAS LIKELY MOVED THE SLIGHT RISK AREA FARTHER NORTH TO ACKNOWLEDGE THE MORE NORTHERLY TRACK OF THE LOW AND HAS NOW INCLUDED THE SOUTHERN PORTION OF REGION IN A SLIGHT RISK. WITH LOW LCL HEIGHTS AND CLOSE PROXIMITY TO THE WARM FRONT WILL NEED TO BE VERY AWARE OF ANY ROTATING STORMS. FARTHER NORTH MORE RAIN IS EXPECTED AS THE REGION WILL BE IN THE ENTRANCE REGION OF THE UPPER JET AS WELL AS IN THE NOSE OF THE LOW LEVEL JET. THIS ISENTROPIC SETUP SHOULD PROVIDE MOD TO STRONG UPWARD MOTION FOR INCREASING HUMID AIR. WOULD NOT RULE OUT 1-2 INCHES OF QPF ON ALREADY NEARLY SATURATED SOIL. WE MAY HAVE MORE WATER/FLOOD ISSUES. WILL HOLD OFF ON MENTIONING ANY FLOOD HEADLINES FOR NOW. WITH THE REGION MORE IN THE WARM SECTOR...WILL RAISE MAX TEMPERATURES AS DEPICTED BY THE DOWNSCALED NAM. THE LOW WILL TRACK EAST THURSDAY EVENING AND THE ATTENDANT TRAILING FRONT WILL STALL SOUTH OF THE REGION. WILL ATTEMPT TO KEEP THE FORECAST DRY FOR FRIDAY BUT CAN NOT RULE OUT A BRIEF LIGHT SHOWER IN THE SOUTH. ANOTHER MORE SIGNIFICANT SHORT WAVE WILL PROGRESS ACROSS THE REGION FRIDAY NIGHT AND DEEPEN AS IT PROGRESSES ACROSS THE REGION OVER THE WEEKEND. THE SREF/GFS/ECMWF ALL TRACK A RATHER STRONG/DEEP SURFACE LOW JUST SOUTH AND EAST OF THE CWA. THIS WILL LIKELY PRODUCE MORE RAIN WHICH MAY BE HEAVY. THE SHOWERS WILL SPREAD INTO THE REGION AFTER MIDNIGHT FRIDAY NIGHT AND CONTINUE INTO SUNDAY. EXPECT THE HEAVIEST RAIN OVER THE CENTRAL AND EASTERN PORTIONS OF THE AREA. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AN UNSEASONABLY STRONG UPPER LOW WILL BE OVERHEAD THE OHIO VALLEY THIS WEEKEND. ON SUNDAY THIS SYSTEM WILL BE SLOWLY PULLING AWAY. GFSENS BRINGS H8 TEMPERATURES DOWN BELOW 10C. HIGHS SUNDAY WILL BE SIGNIFICANTLY BELOW NORMAL...LIKELY NOT GETTING OUT OF THE 60S ACROSS EASTERN OH/NW PA. WILL LINGER PRECIP CHANCES ACROSS THE AREA UNTIL THAT SYSTEM FULLY DEPARTS. MONDAY WILL BE IN BETWEEN SYSTEMS WITH SLIGHT RIDGING. THE NEXT SHORTWAVE OF NOTE WILL ARRIVE WITH A COLD FRONT FOR TUESDAY...RE-ENFORCING THE EASTERN U.S. TROUGH. THIS IS LATER THAN PREVIOUS FORECAST...BUT WITH STRONG AND SLOWER WEEKEND SYSTEM THIS IS EXPECTED. SHOWERS AND THUNDERSTORMS WILL BE ASSOCIATED WITH THIS FRONT. WEDNESDAY SHOULD BE A FAIR WEATHER WITH CURRENT TIMING OF ALL OF THESE SYSTEMS. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... A LOW WILL MOVE INTO OHIO BY LATE THU. WIDESPREAD SHRA AND SOME TSRA ARE EXPECTED TO MOVE INTO TOL AND FDY TOWARD THE END OF THE NIGHT AND SHOULD REACH CLE AROUND 9 TO 10 AM AND FINALLY YNG AND MAYBE ERI ABOUT MIDDAY. THE RAP MODEL AND NOW THE HRRR ARE SHOWING A SLOWER AND FURTHER SOUTHWARD PROGRESSION SO UNCERTAINTY WITH THE FORECAST IS PRESENT. AREAS OF MVFR WILL LIKELY DEVELOP AFTER A FEW HOURS OF RAIN AS THE LOWER LEVELS BECOME SATURATED. WINDS SHOULD STAY LIGHT...GENERALLY UNDER 12 KNOTS THRU THU. OUTLOOK...NON VFR LIKELY THU NIGHT INTO EARLY FRI IN SHRA THEN NON VFR MAY LINGER ACROSS EASTERN OH/NW PA THE REST OF FRI. WIDESPREAD NON VFR RETURNS FOR FRIDAY NIGHT THROUGH SUNDAY IN MORE WIDESPREAD RAIN. && .MARINE... FAIR WEATHER AND A QUIET LAKE TONIGHT. AFTER THAT WEATHER QUITE UNSETTLED. LOW PRESSURE WILL TRACK EAST ACROSS OHIO ON THURSDAY...BRINGING WINDS AROUND TO THE NORTHEAST ON THE LAKE BY THURSDAY EVENING. NORTHEAST WINDS WILL CONTINUE THROUGH FRIDAY AS HIGH PRESSURE REMAINS NEARLY STATIONARY ACROSS THE CENTRAL GREAT LAKES. SIGNIFICANT CHANGES FOR THE WEEKEND FORECAST WITH A TREND TOWARD A STRONG LOW MOVING INTO THE OHIO VALLEY FRIDAY NIGHT AND SLOWLY MOVING UP THE OHIO VALLEY THROUGH THE WEEKEND. THIS WOULD CONTINUE AND STRENGTHEN THE NORTHEAST FLOW ON THE LAKE FOR SATURDAY. STILL STRONG BUT MORE NORTHERLY WINDS ARE EXPECTED SUNDAY AS THE LOW BEGINS TO PULL AWAY. SMALL CRAFT ADVISORIES WILL BE A CERTAINTY. WE ARE TALKING 20 TO 30 KNOTS FOR A BIG CHUNK OF THE WEEKEND. CONDITIONS SLOWLY IMPROVE ON MONDAY WITH HIGH PRESSURE CENTERED OVER THE TN VALLEY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...LAPLANTE NEAR TERM...KEC/LAPLANTE SHORT TERM...LAPLANTE LONG TERM...OUDEMAN AVIATION...ADAMS MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS NORMAN OK
1029 PM CDT THU JUN 25 2015 .AVIATION... 06Z TAFS... A COLD FRONT WILL MOVE ACROSS THE REGION FRIDAY. SCATTERED SHOWERS/STORMS WILL ALSO BE POSSIBLE EARLY FRIDAY MORNING THROUGH FRIDAY EVENING ACROSS THE AREA ALTHOUGH CHANCES ARE TOO LOW FOR MENTION IN SOME TAFS. VFR/LOW VFR CEILINGS ARE EXPECTED... HOWEVER... SOME MVFR CEILINGS ARE NOT OUT OF THE QUESTION AT A FEW LOCATIONS. && .PREV DISCUSSION... /ISSUED 901 PM CDT THU JUN 25 2015/ UPDATE... INCREASED PRECIPITATION CHANCES IN THE NORTH GIVEN THE ROBUST STORMS IN KANSAS AND RECENT HRRR SOLUTIONS SHOWING SOME REDEVELOPMENT OVERNIGHT EVEN IF THESE INITIAL STORMS DO DISSIPATE. HRRR MAY BE TOO AGGRESSIVE BUT STILL BELIEVE THERE IS ENOUGH CHANCE TO INCREASE POPS A LITTLE OVERNIGHT. OTHERWISE... FORECAST APPEARS TO BE IN GOOD SHAPE. PREV DISCUSSION... /ISSUED 617 PM CDT THU JUN 25 2015/ AVIATION... 0Z TAFS...VFR CEILINGS... POSSIBLY SOME MVFR CEILINGS... THIS TAF PERIOD. A COLD FRONT WILL MOVE ACROSS THE REGION FRIDAY. SCATTERED SHOWERS/STORMS WILL BE POSSIBLE FRIDAY... WITH THE BEST CHANCE IN NORTH CENTRAL AND CENTRAL OK ALONG THE FRONT. SOME OF THE RAIN COULD OCCUR IN PARTS OF N OK BEFORE 12Z FRI BUT CHANCES TOO LOW FOR MENTION ATTM. PREV DISCUSSION... /ISSUED 243 PM CDT THU JUN 25 2015/ DISCUSSION... HOT WEATHER PATTERN WILL PERSIST THROUGH THE REST OF TODAY...AS WEAK MID LEVEL RIDGING PREVAILS ACROSS THE REGION WITHIN SOUTHWESTERLY SFC FLOW. HOWEVER...A PATTERN CHANGE IS ON THE WAY AS WE HEAD TOWARD THIS WEEKEND. LATE TONIGHT THROUGH EARLY FRIDAY...A COLD FRONT WILL MOVE FROM KANSAS INTO NORTHERN OKLAHOMA. A FEW STORMS MAY ACCOMPANY THIS FRONT...THOUGH NO SEVERE STORMS ARE EXPECTED THROUGH TONIGHT. THE PRESENCE OF SOUTHWESTERLY WINDS AHEAD OF THE FRONT WILL KEEP OVERNIGHT LOWS QUITE WARM...WITH TEMPS ONLY BOTTOMING OUT IN THE LOW TO MID 70S. THE FRONT WILL CONTINUE TO MOVE SOUTHWARD THROUGH THE DAY ON FRIDAY...AS A DOMINANT UPPER RIDGE BUILDS ACROSS THE WESTERN U.S. TEMPERATURES NORTH OF THE BOUNDARY SHOULD GENERALLY BE IN THE UPPER 80S...WITH LOW TO MID 90S COMMON SOUTH OF THE FRONT. DIFFLUENT UPPER FLOW WILL OVERSPREAD THE AREA ALONG/SOUTH OF THE FRONT BY MID TO LATE AFTERNOON...ALLOWING FOR SCATTERED THUNDERSTORM DEVELOPMENT. GIVEN AMPLE MOISTURE AND INSTABILITY...AND SOME INCREASE IN MID LEVEL WINDS...SEVERE STORMS WILL BE POSSIBLE. THE MAIN CONCERNS WILL BE DAMAGING WIND GUSTS AND LARGE HAIL...THOUGH LOCALLY HEAVY RAINFALL MAY ALSO OCCUR. STORMS WILL LIKELY MERGE INTO ONE OR MORE SOUTHEASTWARD MOVING STORM COMPLEXES...MOVING ALONG THE FRONT TOWARD THE RED RIVER AND INTO NORTH TEXAS OVERNIGHT. IN THE WAKE OF THE FRONT...THE WEEKEND LOOKS FANTASTIC...WITH HIGHS IN THE MID TO UPPER 80S TO LOW 90S...AND A DRIER AIRMASS OVERALL. THE WESTERN U.S. RIDGE/EAST COAST TROUGH CONFIGURATION LOOKS TO LINGER INTO MUCH OF NEXT WEEK...WITH SEVERAL PASSING FRONTS AND ASSOCIATED THUNDERSTORM CHANCES MONDAY THROUGH THE LATTER HALF OF THE WEEK. AUSTIN && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 76 90 67 85 / 10 50 40 10 HOBART OK 75 93 67 87 / 20 40 40 10 WICHITA FALLS TX 76 95 70 87 / 10 30 50 10 GAGE OK 72 87 63 87 / 30 30 10 0 PONCA CITY OK 77 88 66 86 / 30 40 20 10 DURANT OK 75 92 69 85 / 0 20 60 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 26/25/25
AREA FORECAST DISCUSSION
NWS NORMAN OK
901 PM CDT THU JUN 25 2015 .UPDATE... INCREASED PRECIPITATION CHANCES IN THE NORTH GIVEN THE ROBUST STORMS IN KANSAS AND RECENT HRRR SOLUTIONS SHOWING SOME REDEVELOPMENT OVERNIGHT EVEN IF THESE INITIAL STORMS DO DISSIPATE. HRRR MAY BE TOO AGGRESSIVE BUT STILL BELIEVE THERE IS ENOUGH CHANCE TO INCREASE POPS A LITTLE OVERNIGHT. OTHERWISE... FORECAST APPEARS TO BE IN GOOD SHAPE. && .PREV DISCUSSION... /ISSUED 617 PM CDT THU JUN 25 2015/ AVIATION... 0Z TAFS...VFR CEILINGS... POSSIBLY SOME MVFR CEILINGS... THIS TAF PERIOD. A COLD FRONT WILL MOVE ACROSS THE REGION FRIDAY. SCATTERED SHOWERS/STORMS WILL BE POSSIBLE FRIDAY... WITH THE BEST CHANCE IN NORTH CENTRAL AND CENTRAL OK ALONG THE FRONT. SOME OF THE RAIN COULD OCCUR IN PARTS OF N OK BEFORE 12Z FRI BUT CHANCES TOO LOW FOR MENTION ATTM. PREV DISCUSSION... /ISSUED 243 PM CDT THU JUN 25 2015/ DISCUSSION... HOT WEATHER PATTERN WILL PERSIST THROUGH THE REST OF TODAY...AS WEAK MID LEVEL RIDGING PREVAILS ACROSS THE REGION WITHIN SOUTHWESTERLY SFC FLOW. HOWEVER...A PATTERN CHANGE IS ON THE WAY AS WE HEAD TOWARD THIS WEEKEND. LATE TONIGHT THROUGH EARLY FRIDAY...A COLD FRONT WILL MOVE FROM KANSAS INTO NORTHERN OKLAHOMA. A FEW STORMS MAY ACCOMPANY THIS FRONT...THOUGH NO SEVERE STORMS ARE EXPECTED THROUGH TONIGHT. THE PRESENCE OF SOUTHWESTERLY WINDS AHEAD OF THE FRONT WILL KEEP OVERNIGHT LOWS QUITE WARM...WITH TEMPS ONLY BOTTOMING OUT IN THE LOW TO MID 70S. THE FRONT WILL CONTINUE TO MOVE SOUTHWARD THROUGH THE DAY ON FRIDAY...AS A DOMINANT UPPER RIDGE BUILDS ACROSS THE WESTERN U.S. TEMPERATURES NORTH OF THE BOUNDARY SHOULD GENERALLY BE IN THE UPPER 80S...WITH LOW TO MID 90S COMMON SOUTH OF THE FRONT. DIFFLUENT UPPER FLOW WILL OVERSPREAD THE AREA ALONG/SOUTH OF THE FRONT BY MID TO LATE AFTERNOON...ALLOWING FOR SCATTERED THUNDERSTORM DEVELOPMENT. GIVEN AMPLE MOISTURE AND INSTABILITY...AND SOME INCREASE IN MID LEVEL WINDS...SEVERE STORMS WILL BE POSSIBLE. THE MAIN CONCERNS WILL BE DAMAGING WIND GUSTS AND LARGE HAIL...THOUGH LOCALLY HEAVY RAINFALL MAY ALSO OCCUR. STORMS WILL LIKELY MERGE INTO ONE OR MORE SOUTHEASTWARD MOVING STORM COMPLEXES...MOVING ALONG THE FRONT TOWARD THE RED RIVER AND INTO NORTH TEXAS OVERNIGHT. IN THE WAKE OF THE FRONT...THE WEEKEND LOOKS FANTASTIC...WITH HIGHS IN THE MID TO UPPER 80S TO LOW 90S...AND A DRIER AIRMASS OVERALL. THE WESTERN U.S. RIDGE/EAST COAST TROUGH CONFIGURATION LOOKS TO LINGER INTO MUCH OF NEXT WEEK...WITH SEVERAL PASSING FRONTS AND ASSOCIATED THUNDERSTORM CHANCES MONDAY THROUGH THE LATTER HALF OF THE WEEK. AUSTIN && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 76 90 67 85 / 10 50 40 10 HOBART OK 75 93 67 87 / 20 40 40 10 WICHITA FALLS TX 76 95 70 87 / 10 30 50 10 GAGE OK 72 87 63 87 / 30 30 10 0 PONCA CITY OK 77 88 66 86 / 30 40 20 10 DURANT OK 75 92 69 85 / 0 20 60 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
805 PM EDT THU JUN 25 2015 .SYNOPSIS... STRONG MID LEVEL HIGH PRESSURE WILL DISSIPATE ACROSS THE SOUTHEAST FRIDAY AS A SIGNIFICANT COLD FRONT APPROACHES THE AREA...ENDING THE RECENT PERIOD OF ABOVE AVERAGE TEMPS. THE COLD FRONT MOVES THROUGH SATURDAY BRINGING WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE AREA. BY SUNDAY THE FRONT WILL HAVE MOVED EAST OF THE REGION LEAVING BEHIND SLIGHTLY BELOW NORMAL TEMPERATURES AND DRIER AIR ACROSS THE AREA. A WEAK FRONTAL BOUNDARY WILL APPROACH THE AREA BY MID-WEEK AND LINGER NEAR THE REGION...INCREASING CHANCES FOR SHOWERS THROUGH THE END OF NEXT WEEK AND RETURNING TEMPERATURES TO SEASONAL NORMS. && .NEAR TERM /THROUGH FRIDAY/... 730 PM UPDATE...THE CHANCE OF CONVECTION FIRING IN SITU OVER THE CWFA APPEARS MINIMAL. A COUPLE CLUSTERS OF CELLS OVER ERN KY HAVE FORMED IN AN AREA WITH SUFFICIENT INSTABILTIY AND SHEAR THAT THEY LOOKED LIKELY TO ORGANIZE AND PROPAGATE INTO EAST TN...BUT THEY ARE NOT LOOKING THAT HEALTHY NOW THAT THE SUN IS LOWERING. EARLIER CAM RUNS SHOWING A WELL DEVELOPED LINEAR MCS OVERNIGHT ARE NOT VERIFYING WELL SO FAR. THE HRRR IS KEYING ON THE SHEAR...TRYING TO ORGANIZE ACTIVITY OVER KY OR IL OVER THE NEXT COUPLE HRS...BUT THESE RUNS TOO SEEM TO BE A BIT OVERDONE. THE CHANCE OF ANY ACTIVITY MOVING ACRS THE MTNS LOOKS EVEN LESS AT THIS POINT...BUT HAVE KEPT A SCHC NEAR THE TN/NC BORDER FOR THE SECOND HALF OF THE NIGHT. POPS OVER THE PIEDMONT WILL DIMINISH STEADILY THRU THE EVENING. AS OF 230 PM THU...THE AXIS OF A THERMAL SURFACE TROUGH CURRENTLY EXTENDS THROUGH THE CHARLOTTE METRO AREA INTO THE NC TRIAD. SBCAPE ALONG THIS AXIS IS QUITE ROBUST...IN EXCESS OF 3000 J/KG PER THE LATEST SPC MESOANALYSIS. SOME CONGESTUS WAS BEGINNING TO DEVELOP IN THIS AREA...ALTHOUGH FROM ITS APPEARANCE AND SATELLITE...WE/RE STILL PROBABLY A GOOD 1-2 HOURS FROM SEEING THE FIRST CELL INITIATE. THERE ARE STILL DOUBTS AS TO HOW MUCH COVERAGE WILL BE SEEN IN THIS AREA...AND THE CONSENSUS OF CURRENT CAM MODELS STILL SUGGESTS AREAS TO OUR EAST WILL BE MORE LIKELY TO SEE CONVECTION. THUS...HELD POPS IN THE LOW CHANCE RANGE. FARTHER WEST...CONVECTION APPEARS EVEN LESS LIKELY TO INITIATE ANYTIME SOON. DEWPOINTS WERE MIXING OUT ACROSS THE MTNS...AND THE CU FIELD THERE IS ATYPICALLY FLAT AND SPARSE. HELD ON TO A SLIGHT CHANCE POPS ACROSS MOST OF THE REMAINDER OF THE AREA...WITH A LOW CHANCE IN THE CLIMO-FAVORED INITIATION AREA ACROSS THE UPPER FRENCH BROAD VALLEY AND VICINITY...BUT EVEN THIS MAY PROVE TO BE A BIT OF A STRETCH. ATTENTION THIS EVENING WILL TURN TOWARD THE OHIO VALLEY...WHERE CONVECTION IS FORECAST TO DEVELOP ALONG A FRONTAL ZONE. SBCAPE IN THIS REGION HAS INCREASED TO AS MUCH AS 5000 J/KG THIS AFTERNOON...WHILE BULK SHEAR IS MORE THAN RESPECTABLE FOR LATE JUNE. SOME OF THE CONVECTION-ALLOWING MODELS AND SHORT TERM GUIDANCE ORGANIZES CLUSTERS OF CONVECTION FROM THE OHIO VALLEY INTO THE CENTRAL APPALACHIANS...AND TRIES TO DROP SOME ACTIVITY TOWARD THE WESTERN CAROLINAS LATER THIS EVENING. JUST DO NOT HAVE MUCH CONFIDENCE THAT ORGANIZED CONVECTION WILL BE ABLE TO SUSTAIN ITSELF THIS FAR SOUTHEAST...WHERE SHEAR AND INSTABILITY ARE EXPECTED TO REMAIN CONSIDERABLY WEAKER. THUS...WILL LIMIT OVERNIGHT POPS TO A SLIGHT CHANCE ACROSS THE FAR NW ZONES. FRIDAY WILL BE ANOTHER QUITE UNSTABLE DAY ACROSS THE FORECAST AREA...WITH TEMPS EXPECTED TO SOAR INTO THE 90S ONCE AGAIN. IN TERMS OF THE CONVECTIVE POTENTIAL...MIXED SIGNALS ABOUND...WITH THE NAM BLOWING UP A CONSIDERABLE AMOUNT OF CONVECTIVE QPF ACROSS THE AREA DURING THE AFTERNOON...WHILE THE GFS AND OPERATIONAL CAMS DEPICT VERY LITTLE IN THE WAY OF CONVECTION OUTSIDE THE MTNS. AS SURFACE LOW PRESSURE DEVELOPS ACROSS THE OHIO VALLEY LATE IN THE DAY...THERE COULD BE A PSEUDO-WARM FRONT/SURFACE TROUGH THAT DEVELOPS ACROSS THE AREA...POSSIBLY PROVIDING AN ADDITIONAL FOCUS FOR CONVECTION. IN ADDITION...HEIGHT FALLS ARE EXPECTED TO BEGIN OVERSPREADING THE AREA BY LATE IN THE DAY. THEREFORE...WILL FORECAST 50-60 POPS ACROSS A MAJORITY OF THE AREA...FAVORING THE EVENING HOURS FOR THE HIGHEST COVERAGE. SEVERE STORMS WILL BE POSSIBLE...ESPECIALLY IF THE ATMOSPHERE DOES WAIT THAT LATE IN THE DAY TO RELEASE INSTABILITY... WHILE HEIGHT FALLS WILL RESULT IN IMPROVING PROFILES...WITH POSSIBLY AS MUCH AS 25 KTS OF DEEP LAYER SHEAR ANTICIPATED BY EVENING. && .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/... AS OF 210 PM...EXPECT THAT RATHER WIDESPREAD CONVECTION WILL BE ONGOING AT THE START OF THE PERIOD FRIDAY EVENING AS THE RESULT OF CONVERGENCE ASSOCIATED WITH A WEAK LOW MOVING NORTHEAST ACROSS THE SC PIEDMONT IN NC. THE NAM SEEMS TO BE MOST CONSISTENT WITH THIS FEATURE AND RESULTANT CONVECTION. HENCE...WILL ADVERTISE SCT- NUMEROUS TYPE POPS FRIDAY EVENING AND SOME OF THESE STORMS COULD BE SEVERE AS THEY TAP INTO AN AIRMASS WITH CAPES IN EXCESS OF 2000J AND ENOUGH DRY AIR ALOFT FOR A FEW MICROBURSTS. SOME LOCALLY HEAVY RAIN IS ALSO POSSIBLE AS PRECIP. WATER INCREASES TO AROUND 2 INCHES OVER THE PIEDMONT WITH SLOW MOVING STORMS. CONVECTION SHOULD WANE OVER OUR AREA AS IT MOVES/REDEVLOPS EASTWARD. HENCE...WILL SHOW A DECREASING TREND IN THE POPS OVERNIGHT BUT SOME SCT SHOWERS/THUNDERSTORMS MAY PERSIST AS HEIGHTS FALL AS UPPER TROUGH APPROACHES. ON SATURDAY...THE 12Z OPERATIONAL MODELS ARE IN AGREEMENT THAT THE WELL ADVERTISED COLD FRONT IS STILL ON TRACK TO CROSS THE AREA AS AN UPPER TROUGH DEVELOPS OVER THE EAST. BULK SHEAR IS FORECAST TO INCREASE INTO THE 30-40 KT RANGE AS THE FRONT APPROACHES. HOWEVER... ONLY MODEST INSTABILITY IN THE RANGE OF 1000-1500J IS FORECAST. THIS MAY BE ENOUGH FOR SOME ORGANIZED LINE SEGMENTS TO DEVELOP ALONG AND AHEAD OF THE COLD FRONT DURING THE SATURDAY. THEREFORE...SOME SCT DAMAGING WIND EVENTS ARE POSSIBLE MAINLY OUTSIDE THE MOUNTAINS WHERE THE BEST INSTABILITY WILL EXIST. SPC HAS A LARGE PART OF THE CWA IN A MARGINAL RISK FOR SEVERE STORMS ON SAT. THE FRONT AND ASSOCIATED SHOWERS/STORMS WILL MOVE EAST OF THE AREA SATURDAY EVENING. A MUCH DRYER AND COOLER AIRMASS WILL BEGIN OVERSPREADING THE AREA SAT NIGHT PRODUCING CLEARING. HIGH PRESSURE WILL BUILD OVER THE AREA ON SUNDAY PRODUCING PLENTY OF SUNSHINE WITH PLEASANT TEMPS AND MUCH LOWER HUMIDITY. STAYED CLOSE TO A MODEL BLEND FOR MOST GRID FIELDS...EXCEPT LEANED ON THE NAM FOR POP TRENDS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... AS OF 300 PM THURSDAY...THE EXTENDED PERIOD BEGINS SUNDAY DRY AND WITH SLIGHTLY BELOW AVERAGE TEMPERATURES THANKS TO A SIGNIFICANT COLD FRONTAL PASSAGE. TEMPERATURES REBOUND TO SEASONAL LEVELS THROUGH THE REMAINDER OF THE WEEK AS THE AREA REMAINS NEAR THE BASE OF A BROAD MID-LEVEL TROUGH. GUIDANCE BRINGS A WEAKENING FRONT INTO THE AREA BY MIDWEEK ASSOCIATED WITH A SHORTWAVE TROUGH OVER THE LOWER GREAT LAKES. THE FRONT WILL STALL INVOF THE TENNESSEE VALLEY THROUGH THE REMAINDER OF THE WEEK AS WEAK SHORTWAVES RIDE THE BASE OF THE TROUGH. AS A RESULT...CHANCE POPS EXIST ACROSS THE AREA BEGINNING TUESDAY AND LASTING THROUGH THE WEEK WITH THE HIGHEST POPS ACROSS THE MOUNTAINS CLOSER TO THE DIFFUSE FRONTAL BOUNDARY AND WEAK SHORTWAVE ENERGY. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... AT KCLT...EXPECTING VFR THRU FRI MRNG WITH DRY PROFILES AND WITH DEWPOINTS HAVING MIXED OUT APPRECIABLY THU AFTN. CYCLONIC UPPER FLOW WILL SPIN UP A WEAK SFC LOW OVER THE MID-ATLANTIC COAST TONIGHT WHICH WILL EVENTUALLY VEER WINDS TO NW. THESE WINDS WILL PERSIST THRU THE MRNG BEFORE STRONGER LOW PRESSURE DEVELOPS OVER THE OHIO VALLEY AND WINDS RETURN TO SW. HEIGHTS ALOFT GRADUALLY BEGIN TO FALL FRIDAY WHICH WILL INCREASINGLY SUPPORT CONVECTION THRU THE DAY. BEST TSRA CHANCE IS LIKELY NEAR THE END OF THE PERIOD...BUT CHC SUPPORTS PROB30 FROM 18Z ONWARD. ELSEWHERE...EXPECTING VFR AT ALL TERMINALS INTO FRI MRNG. TSRA NOW OVER ERN KY MAY PROPAGATE SWD TO NEAR THE TN/NC BORDER LATER TONIGHT. HOWEVER THE CHC OF ANY PRECIP CROSSING THE MTNS IS QUITE LOW...THOUGH SOME REMNANT LOW VFR CLOUDS COULD DRIFT OVER KAVL. SOME OF THE OUTLYING MTN VALLEYS MAY FOG UP OVERNIGHT. DESTABILIZATION AND TSRA WILL LIKELY BE A BIT LATER THAN NORMAL ON FRIDAY...AS UPPER DYNAMIC FORCING STRENGTHENS OVER THE AREA...BUT CHC RAMPS UP TO A MENTIONABLE LEVEL BY MIDDAY. LIGHT NWLY WINDS WILL RETURN OVERNIGHT OVER NC IN RESPONSE TO LOW PRESSURE DEVELOPING OVER THE MID-ATLANTIC...WITH THE SC SITES LIKELY REMAINING SW. ALL SITES RETURN SW BY FRI AFTN AS A STRONGER LOW DEVELOPS TO THE W. OUTLOOK...A COLD FRONT APPROACHES FROM THE NW FRI NIGHT AND PASSES SATURDAY. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE...PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY...AND IN THE MOUNTAIN RIVER VALLEYS. BEHIND THE COLD FRONT...A MUCH DRIER AND COOLER AIRMASS WILL OVERSPREAD THE REGION FOR EARLY NEXT WEEK...WITH A SECOND COLD FRONT POSSIBLY ARRIVING BY MID-WEEK. CONFIDENCE TABLE... 00-06Z 06-12Z 12-18Z 18-00Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 97% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% 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...JP NEAR TERM...JDL/WIMBERLEY SHORT TERM...LG LONG TERM...JP AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
459 PM EDT WED JUN 24 2015 .SYNOPSIS... STRONG MID LEVEL HIGH PRESSURE WILL PERSIST ACROSS THE REGION THROUGH THE REMAINDER OF THE WORK WEEK...MAINTAINING WELL ABOVE NORMAL TEMPERATURES. A BROAD UPPER LEVEL TROF WILL MOVE OVER THE REGION OVER THE WEEKEND RETURNING TEMPERATURES TO SEASONAL LEVELS BY SUNDAY AND INCREASING CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS. A COOLER AND DRIER PATTERN WILL TAKE SHAPE AFTER A FRONT PASSES EARLY IN THE WEEK BEFORE ANOTHER FRONTAL BOUNDARY APPROACHES THE AREA LATER NEXT WEEK. && .NEAR TERM /THROUGH THURSDAY/... 445 PM UPDATE...CLUSTERS OF CONVECTION ARE ONGOING OVER NE GA AND THE SRN FACING BLUE RIDGE OF SW NC. GENERAL CONSENSUS FROM CONVECTION ALLOWING GUIDANCE IS THAT THE ACTIVITY WILL PROPAGATE SEWD OVER THE NEXT 2-3 HRS. SOME DEVELOPMENT OF SHOWERS OR TSTMS OVER THE NC PIEDMONT AND ERN UPSTATE CANNOT BE RULED OUT...BUT THE LOOK OF CUMULUS ON SATELLITE SUGGESTS SPARSE COVERAGE AT BEST. A COUPLE OF LIGHT RETURNS HAVE BEEN SEEN ON RADAR IN THESE AREAS...BUT MODEL PROGS OF WIDESPREAD SMALL CELLS DEVELOPING JUST LOOKS OVERDONE. POPS HAVE BEEN REDUCED BASICALLY EAST OF I-26. AS OF 230 PM...CUMULUS CLOUDS HAVE CAPPED THE TEMP RUN UP SOMEWHAT THIS AFTERNOON PARTICULARLY IN THE GREENVILLE-SPARTANBURG AREA. THEREFORE...DIALED BACK THE MAX TEMPS BY A 2-3 DEGREES THOSE AREAS. THE RISE AT CLT HAS SLOWED AS WELL SO THEY SHOULD COME UP SHY OF 100. CONVECTION FIRING OVER FAR WESTERN NC AND NE GA AS EXPECTED. LATEST HRRR USES THE SFC TROUGH LAYING ACROSS UPSTATE SC INTO WESTERN NC TO DEVELOP SCT THUNDERSTORMS BY LATE AFTERNOON. WITH CAPES BETWEEN 2000-3000J AND DCAPES >1000J A FEW WET DAMAGING MICROBURSTS ARE LIKELY. THE CONVECTION SHOULD ASH OUT DURING THE EVENING WITH THE LOSS OF HEATING. FOR THE OVERNIGHT...IT WILL BE A MUGGY NIGHT WITH CLEAR TO PARTLY CLOUDY CONDITIONS. MIN TEMPS WILL BE WELL ABOVE CLIMO WITH LOW TO MID 70S OUTSIDE THE MOUNTAINS AND LOW TO MID 60S MOUNTAINS. THURSDAY WILL BE ANOTHER HOT DAY AS THE UPPER HIGH TO THE WEST BEGINS TO SLIP EASTWARD BUT WEAKEN SOMEWHAT. ALSO SUBTLE CHANGES OCCUR AT THE SURFACE AS THE WEAK BOUNDARY ACROSS THE AREA IS FORECAST TO MOVE NORTHEAST AS A LOW MOVES THROUGH THE OHIO VALLEY. HENCE...THE AMOUNT OF FORCING FOR THUNDERSTORMS WILL BE SOMEWHAT LESS WITH SOME DEGREE OF SYNOPTIC SUBSIDENCE. HOWEVER...FORECAST SOUNDINGS SHOW CIN ERODING IN THE AFTERNOON TO WHERE WE EXPECT A FEW UPDRAFTS TO BREAK THE CAP. HENCE...WILL CARRY ISOLATED TO SCATTERED POPS OVER THE MOUNTAINS AND THE SOUTHERN PIEDMONT. THE OTHER CONCERN WILL CONTINUE TO BE THE HEAT. HAVE GONE ON THE HIGH END OF THE GUIDANCE ENVELOPE FOR MAX TEMPS ON FRIDAY WHICH IS WHAT THE THICKNESS WOULD SUPPORT. DEWPOINTS WILL TRY TO MIX OUT SOME DURING THE AFTERNOON...BUT PROBABLY NOT ENOUGH TO PRECLUDE AN HOUR OR TWO OF APPARENT TEMPS REACHING 105 ACROSS PARTS OF THE UPSTATE. IF CURRENT NUMBERS HOLD...MAY HAVE TO CONSIDER A HEAT ADVISORY FOR PARTS OF NE GA...UPSTATE SC AND PERHAPS THE CLT AREA. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... AS OF 145 PM WEDNESDAY...THE BIG STORY OF THE SHORT TERM PERIOD WILL BE THE SIGNIFICANT PATTERN CHANGE THAT IS ANTICIPATED...AS A SIGNIFICANT SHORT WAVE DIVES OUT OF THE NORTHERN CONUS...AND CARVES OUT A LONG WAVE TROUGH ACROSS THE EASTERN CONUS BY THE START OF THE WEEKEND. SURFACE LOW PRESSURE TRACKING ALONG THE ASSOCIATED FRONTAL ZONE...FROM THE TENN TO THE OHIO VALLEY IS EXPECTED TO ACTIVATE A PSEUDO-WARM FRONT/E-W ORIENTED CONVERGENCE ZONE ACROSS THE REGION ON FRIDAY...AND THIS COULD ACT AS AN ADDITIONAL FOCUS FOR CONVECTIVE INITIATION ACROSS OUR AREA FRI AFTERNOON. HOWEVER...THERE ARE QUITE A FEW MIXED SIGNALS IN THE GUIDANCE REGARDING HOW WIDESPREAD ANY CONVECTION WILL BE DURING THE AFTERNOON. THE HIGHEST POPS (LIKELY) WILL BE FOCUSED ACROSS THE NORTHERN ZONES...WHERE A MODEL CONSENSUS SUGGESTS THE CONVERGENCE ZONE WILL RESIDE DURING PEAK HEATING...AND ACROSS THE HIGH TERRAIN...WHERE THE COMBINATION OF TERRAIN EFFECTS AND INCREASED CONVERGENCE SHOULD RESULT IN HIGHER THAN NORMAL COVERAGE. DESPITE IMPROVING MID/UPPER FLOW RESPONDING TO HEIGHT FALLS...SHEAR MAGNITUDE WILL REMAIN QUITE WEAK OWING TO UNIDIRECTIONAL PROFILES. NEVERTHELESS...A FEW SEVERE STORMS WILL BE POSSIBLE. WITH HEIGHTS CONTINUING TO FALL AND AN APPROACHING FRONTAL ZONE... GOOD CHANCES FOR CONVECTION ARE EXPECTED TO CONTINUE WELL INTO FRI NIGHT...AND LIKELY POPS WILL ACTUALLY BE CARRIED THROUGH THE OVERNIGHT HOURS...DUE TO THE POTENTIAL FOR PRE-FRONTAL CONVECTION MOVING INTO THE FORECAST AREA...BUT ALSO DUE TO DEVELOPMENT OF AN ANOMALOUSLY STRONG W/SW LOW LEVEL FLOW...WHICH COULD ALLOW FOR SOME TERRAIN-INDUCED CONVECTION. SATURDAY WILL FEATURE AMPLE GOOD SOURCES OF LIFT...WITH LOW LEVEL CONVERGENCE ALONG THE FRONT...AND AN UPPER PATTERN SUPPORTIVE OF UVV. HOWEVER...SATURDAY WILL BE THE MOST STABLE DAY OF THE WEEK AS WELL...OWING TO THE LIKELIHOOD OF ABUNDANT MORNING CLOUD COVER AND DEEP MOIST ADIABATIC LAPSE RATES. ON THE OTHER HAND...SHEAR WILL BE RATHER IMPRESSIVE FOR LATE JUNE...ABOUT 30 KTS THROUGH A DEEP LAYER. SOME UPSCALE ORGANIZATION COULD THEREFORE OCCUR IF POCKETS OF MORE ROBUST INSTABILITY CAN BE REALIZED. LIKELY POPS WILL BE CARRIED ACROSS THE MAJORITY OF THE AREA SAT AFTERNOON. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 300 PM WEDNESDAY...THE MEDIUM RANGE BEGINS SATURDAY NIGHT WITH A FRONTAL BOUNDARY APPROACHING THE FORECAST AREA. POPS WILL REMAIN ELEVATED THROUGH EARLY SUNDAY BEFORE THE FRONT CLEARS THE REGION AND DRIER AIR WORKS IN. THE PLEASANT DRIER AND UNSEASONABLY COOL REGIME WILL PERSIST THROUGH MONDAY AND PERHAPS EARLY TUESDAY. LOW-LEVEL FLOW TURNS SOUTHWESTERLY ON TUESDAY...ADVECTING SLIGHTLY WARMER AND MORE MOIST AIR INTO THE CWA. ANOTHER FRONT APPROACHES THE AREA TOWARDS THE END OF THE PERIOD. MODEL DISCREPANCIES ON TIMING AND ASSOCIATED QPF AMOUNTS REMAIN SIGNIFICANT THOUGH INCREASED POPS TOWARDS THE END OF THE PERIOD ARE LIKELY. GIVEN ABUNDANT CLOUD COVER ASSOCIATED WITH THE INITIAL FRONTAL PASSAGE...TEMPS WILL BE 5-10 DEGREES BELOW CLIMO ON SUNDAY AND MONDAY. HEADING INTO TUESDAY TEMPS WILL RECOVER TO NEAR NORMAL VALUES AND REMAIN NEAR NORMAL THROUGH THE END OF THE PERIOD. && .AVIATION /21Z WEDNESDAY THROUGH MONDAY/... AT KCLT...A WEAK FRONTAL TROUGH IN THE VICINITY OF THE AIRFIELD WILL SERVE TO TRIGGER ISOLD TO WIDELY SCT TSRA IN UNSTABLE AIRMASS. HENCE...WILL CARRY A TEMPO TSRA FROM 22-00Z THIS AFTERNOON. OTHERWISE...VFR CUMULUS WILL DISSIPATE AFTER SUNSET. WINDS SHOULD PREVAIL NORTHERLY BUT OCNL VARIABILITY IS POSSIBLE DUE TO THE PROXIMITY OF THE TROUGH...AND ANY NEARBY TSRA WILL PRODUCE GUSTY OUTFLOWS. ELSEWHERE...AIRMASS IS QUITE UNSTABLE OUTSIDE THE MOUNTAINS THIS AFTERNOON ALONG WITH A WEAK FRONTAL TROUGH EXTENDING FROM WESTERN NC...THROUGH UPSTATE SC INTO NE GA. SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP BY MID AFTERNOON. CAMS FAVOR WESTERN AREAS WITH THE BEST COVERAGE...SO WILL CARRY A TEMPO TSRA AT KAND. WILL MENTION VCTS AT GSP AND GMU. THE CHANCE OF TSRA TOO LOW TO MENTION AT AVL AND HKY. EXPECT SOME FOG FORMATION EARLY THURSDAY MORNING WITH GUIDANCE SUGGESTING MVFR RESTRICTIONS AT AVL AND HKY. OUTLOOK...TSTM CHANCES WILL INCREASE LATE IN THE WEEK INTO THE WEEKEND AS A COLD FRONT EVENTUALLY APPROACHES FROM THE NW. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE...PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY...AND IN THE MOUNTAIN RIVER VALLEYS. BEHIND THE COLD FRONT...A MUCH DRYER AND COOLER AIRMASS WILL OVERSPREAD THE REGION ON SUNDAY. CONFIDENCE TABLE... 21-03Z 03-09Z 09-15Z 15-18Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 91% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 91% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 91% 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 && .CLIMATE... RECORD MAXIMUM TEMPERATURES FOR THIS WEEK...WITH YEARS IN WHICH THE VALUES WERE LAST REACHED. WEDNESDAY JUNE 24... AVL 94 1952 CLT 102 1930 GSP 100 1952 THURSDAY JUNE 25... AVL 96 1952 CLT 102 1914 GSP 101 1952 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...LEV NEAR TERM...LG/WIMBERLEY SHORT TERM...JDL LONG TERM...JP/LEV AVIATION...LG/WIMBERLEY CLIMATE...GSP
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
346 PM EDT WED JUN 24 2015 .SYNOPSIS... STRONG MID LEVEL HIGH PRESSURE WILL PERSIST ACROSS THE REGION THROUGH THE REMAINDER OF THE WORK WEEK...MAINTAINING WELL ABOVE NORMAL TEMPERATURES. A BROAD UPPER LEVEL TROF WILL MOVE OVER THE REGION OVER THE WEEKEND RETURNING TEMPERATURES TO SEASONAL LEVELS BY SUNDAY AND INCREASING CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS. A COOLER AND DRIER PATTERN WILL TAKE SHAPE AFTER A FRONT PASSES EARLY IN THE WEEK BEFORE ANOTHER FRONTAL BOUNDARY APPROACHES THE AREA LATER NEXT WEEK. && .NEAR TERM /THROUGH THURSDAY/... AS OF 230 PM...CUMULUS CLOUDS HAVE CAPPED THE TEMP RUN UP SOMEWHAT THIS AFTERNOON PARTICULARLY IN THE GREENVILLE-SPARTANBURG AREA. THEREFORE...DIALED BACK THE MAX TEMPS BY A 2-3 DEGREES THOSE AREAS. THE RISE AT CLT HAS SLOWED AS WELL SO THEY SHOULD COME UP SHY OF 100. CONVECTION FIRING OVER FAR WESTERN NC AND NE GA AS EXPECTED. LATEST HRRR USES THE SFC TROUGH LAYING ACROSS UPSTATE SC INTO WESTERN NC TO DEVELOP SCT THUNDERSTORMS BY LATE AFTERNOON. WITH CAPES BETWEEN 2000-3000J AND DCAPES >1000J A FEW WET DAMAGING MICROBURSTS ARE LIKELY. THE CONVECTION SHOULD ASH OUT DURING THE EVENING WITH THE LOSS OF HEATING. FOR THE OVERNIGHT...IT WILL BE A MUGGY NIGHT WITH CLEAR TO PARTLY CLOUDY CONDITIONS. MIN TEMPS WILL BE WELL ABOVE CLIMO WITH LOW TO MID 70S OUTSIDE THE MOUNTAINS AND LOW TO MID 60S MOUNTAINS. THURSDAY WILL BE ANOTHER HOT DAY AS THE UPPER HIGH TO THE WEST BEGINS TO SLIP EASTWARD BUT WEAKEN SOMEWHAT. ALSO SUBTLE CHANGES OCCUR AT THE SURFACE AS THE WEAK BOUNDARY ACROSS THE AREA IS FORECAST TO MOVE NORTHEAST AS A LOW MOVES THROUGH THE OHIO VALLEY. HENCE...THE AMOUNT OF FORCING FOR THUNDERSTORMS WILL BE SOMEWHAT LESS WITH SOME DEGREE OF SYNOPTIC SUBSIDENCE. HOWEVER...FORECAST SOUNDINGS SHOW CIN ERODING IN THE AFTERNOON TO WHERE WE EXPECT A FEW UPDRAFTS TO BREAK THE CAP. HENCE...WILL CARRY ISOLATED TO SCATTERED POPS OVER THE MOUNTAINS AND THE SOUTHERN PIEDMONT. THE OTHER CONCERN WILL CONTINUE TO BE THE HEAT. HAVE GONE ON THE HIGH END OF THE GUIDANCE ENVELOPE FOR MAX TEMPS ON FRIDAY WHICH IS WHAT THE THICKNESS WOULD SUPPORT. DEWPOINTS WILL TRY TO MIX OUT SOME DURING THE AFTERNOON...BUT PROBABLY NOT ENOUGH TO PRECLUDE AN HOUR OR TWO OF APPARENT TEMPS REACHING 105 ACROSS PARTS OF THE UPSTATE. IF CURRENT NUMBERS HOLD...MAY HAVE TO CONSIDER A HEAT ADVISORY FOR PARTS OF NE GA...UPSTATE SC AND PERHAPS THE CLT AREA. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... AS OF 145 PM WEDNESDAY...THE BIG STORY OF THE SHORT TERM PERIOD WILL BE THE SIGNIFICANT PATTERN CHANGE THAT IS ANTICIPATED...AS A SIGNIFICANT SHORT WAVE DIVES OUT OF THE NORTHERN CONUS...AND CARVES OUT A LONG WAVE TROUGH ACROSS THE EASTERN CONUS BY THE START OF THE WEEKEND. SURFACE LOW PRESSURE TRACKING ALONG THE ASSOCIATED FRONTAL ZONE...FROM THE TENN TO THE OHIO VALLEY IS EXPECTED TO ACTIVATE A PSEUDO-WARM FRONT/E-W ORIENTED CONVERGENCE ZONE ACROSS THE REGION ON FRIDAY...AND THIS COULD ACT AS AN ADDITIONAL FOCUS FOR CONVECTIVE INITIATION ACROSS OUR AREA FRI AFTERNOON. HOWEVER...THERE ARE QUITE A FEW MIXED SIGNALS IN THE GUIDANCE REGARDING HOW WIDESPREAD ANY CONVECTION WILL BE DURING THE AFTERNOON. THE HIGHEST POPS (LIKELY) WILL BE FOCUSED ACROSS THE NORTHERN ZONES...WHERE A MODEL CONSENSUS SUGGESTS THE CONVERGENCE ZONE WILL RESIDE DURING PEAK HEATING...AND ACROSS THE HIGH TERRAIN...WHERE THE COMBINATION OF TERRAIN EFFECTS AND INCREASED CONVERGENCE SHOULD RESULT IN HIGHER THAN NORMAL COVERAGE. DESPITE IMPROVING MID/UPPER FLOW RESPONDING TO HEIGHT FALLS...SHEAR MAGNITUDE WILL REMAIN QUITE WEAK OWING TO UNIDIRECTIONAL PROFILES. NEVERTHELESS...A FEW SEVERE STORMS WILL BE POSSIBLE. WITH HEIGHTS CONTINUING TO FALL AND AN APPROACHING FRONTAL ZONE... GOOD CHANCES FOR CONVECTION ARE EXPECTED TO CONTINUE WELL INTO FRI NIGHT...AND LIKELY POPS WILL ACTUALLY BE CARRIED THROUGH THE OVERNIGHT HOURS...DUE TO THE POTENTIAL FOR PRE-FRONTAL CONVECTION MOVING INTO THE FORECAST AREA...BUT ALSO DUE TO DEVELOPMENT OF AN ANOMALOUSLY STRONG W/SW LOW LEVEL FLOW...WHICH COULD ALLOW FOR SOME TERRAIN-INDUCED CONVECTION. SATURDAY WILL FEATURE AMPLE GOOD SOURCES OF LIFT...WITH LOW LEVEL CONVERGENCE ALONG THE FRONT...AND AN UPPER PATTERN SUPPORTIVE OF UVV. HOWEVER...SATURDAY WILL BE THE MOST STABLE DAY OF THE WEEK AS WELL...OWING TO THE LIKELIHOOD OF ABUNDANT MORNING CLOUD COVER AND DEEP MOIST ADIABATIC LAPSE RATES. ON THE OTHER HAND...SHEAR WILL BE RATHER IMPRESSIVE FOR LATE JUNE...ABOUT 30 KTS THROUGH A DEEP LAYER. SOME UPSCALE ORGANIZATION COULD THEREFORE OCCUR IF POCKETS OF MORE ROBUST INSTABILITY CAN BE REALIZED. LIKELY POPS WILL BE CARRIED ACROSS THE MAJORITY OF THE AREA SAT AFTERNOON. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 300 PM WEDNESDAY...THE MEDIUM RANGE BEGINS SATURDAY NIGHT WITH A FRONTAL BOUNDARY APPROACHING THE FORECAST AREA. POPS WILL REMAIN ELEVATED THROUGH EARLY SUNDAY BEFORE THE FRONT CLEARS THE REGION AND DRIER AIR WORKS IN. THE PLEASANT DRIER AND UNSEASONABLY COOL REGIME WILL PERSIST THROUGH MONDAY AND PERHAPS EARLY TUESDAY. LOW-LEVEL FLOW TURNS SOUTHWESTERLY ON TUESDAY...ADVECTING SLIGHTLY WARMER AND MORE MOIST AIR INTO THE CWA. ANOTHER FRONT APPROACHES THE AREA TOWARDS THE END OF THE PERIOD. MODEL DISCREPANCIES ON TIMING AND ASSOCIATED QPF AMOUNTS REMAIN SIGNIFICANT THOUGH INCREASED POPS TOWARDS THE END OF THE PERIOD ARE LIKELY. GIVEN ABUNDANT CLOUD COVER ASSOCIATED WITH THE INITIAL FRONTAL PASSAGE...TEMPS WILL BE 5-10 DEGREES BELOW CLIMO ON SUNDAY AND MONDAY. HEADING INTO TUESDAY TEMPS WILL RECOVER TO NEAR NORMAL VALUES AND REMAIN NEAR NORMAL THROUGH THE END OF THE PERIOD. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... AT KCLT...A WEAK FRONTAL TROUGH IN THE VICINITY OF THE AIRFIELD WILL SERVE TO TRIGGER SCT TSRA AS AIRMASS IS QUITE UNSTABLE THIS AFTERNOON. HENCE...WILL CARRY A TEMPO TSRA FROM 21-23Z THIS AFTERNOON. OTHERWISE...VFR CUMULUS WILL DISSIPATE AFTER SUNSET. ELSEWHERE...AIRMASS IS QUITE UNSTABLE OUTSIDE THE MOUNTAINS THIS AFTERNOON ALONG WITH A WEAK FRONTAL TROUGH EXTENDING FROM WESTERN NC...THROUGH UPSTATE SC INTO NE GA. SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP BY MID AFTERNOON. CAMS FAVOR WESTERN AREAS WITH THE BEST COVERAGE...SO WILL CARRY A TEMPO TSRA AT KAND. WILL MENTION VCTS AT GSP AND GMU. THE CHANCE OF TSRA TOO LOW TO MENTION AT AVL AND HKY. EXPECT SOME FOG FORMATION EARLY THURSDAY MORNING WITH GUIDANCE SUGGESTING MVFR RESTRICTIONS AT AVL AND HKY. OUTLOOK...TSTM CHANCES WILL INCREASE LATE IN THE WEEK INTO THE WEEKEND AS A COLD FRONT EVENTUALLY APPROACHES FROM THE NW. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE...PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY...AND IN THE MOUNTAIN RIVER VALLEYS. BEHIND THE COLD FRONT...A MUCH DRYER AND COOLER AIRMASS WILL OVERSPREAD THE REGION ON SUNDAY. CONFIDENCE TABLE... 19-01Z 01-07Z 07-13Z 13-18Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 86% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 96% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 93% HIGH 100% KGMU HIGH 86% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 93% 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 && .CLIMATE... RECORD MAXIMUM TEMPERATURES FOR THIS WEEK...WITH YEARS IN WHICH THE VALUES WERE LAST REACHED. THURSDAY JUNE 25... AVL 96 1952 CLT 102 1914 GSP 101 1952 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...LEV NEAR TERM...LG SHORT TERM...JDL LONG TERM...JP/LEV AVIATION...LG CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
252 PM EDT WED JUN 24 2015 .SYNOPSIS... STRONG MID LEVEL HIGH PRESSURE WILL PERSIST ACROSS THE REGION THROUGH THE REMAINDER OF THE WORK WEEK...MAINTAINING WELL ABOVE NORMAL TEMPERATURES. A BROAD UPPER LEVEL TROF WILL MOVE OVER THE REGION OVER THE WEEKEND RETURNING TEMPERATURES TO SEASONAL LEVELS BY SUNDAY AND INCREASING CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS. A COOLER AND DRIER PATTERN WILL TAKE SHAPE AFTER A FRONT PASSES EARLY IN THE WEEK BEFORE ANOTHER FRONTAL BOUNDARY APPROACHES THE AREA LATER NEXT WEEK. && .NEAR TERM /THROUGH THURSDAY/... AS OF 230 PM...CUMULUS CLOUDS HAVE CAPPED THE TEMP RUN UP SOMEWHAT THIS AFTERNOON PARTICULARLY IN THE GREENVILLE-SPARTANBURG AREA. THEREFORE...DIALED BACK THE MAX TEMPS BY A 2-3 DEGREES THOSE AREAS. THE RISE AT CLT HAS SLOWED AS WELL SO THEY SHOULD COME UP SHY OF 100. CONVECTION FIRING OVER FAR WESTERN NC AND NE GA AS EXPECTED. LATEST HRRR USES THE SFC TROUGH LAYING ACROSS UPSTATE SC INTO WESTERN NC TO DEVELOP SCT THUNDERSTORMS BY LATE AFTERNOON. WITH CAPES BETWEEN 2000-3000J AND DCAPES >1000J A FEW WET DAMAGING MICROBURSTS ARE LIKELY. THE CONVECTION SHOULD ASH OUT DURING THE EVENING WITH THE LOSS OF HEATING. FOR THE OVERNIGHT...IT WILL BE A MUGGY NIGHT WITH CLEAR TO PARTLY CLOUDY CONDITIONS. MIN TEMPS WILL BE WELL ABOVE CLIMO WITH LOW TO MID 70S OUTSIDE THE MOUNTAINS AND LOW TO MID 60S MOUNTAINS. THURSDAY WILL BE ANOTHER HOT DAY AS THE UPPER HIGH TO THE WEST BEGINS TO SLIP EASTWARD BUT WEAKEN SOMEWHAT. ALSO SUBTLE CHANGES OCCUR AT THE SURFACE AS THE WEAK BOUNDARY ACROSS THE AREA IS FORECAST TO MOVE NORTHEAST AS A LOW MOVES THROUGH THE OHIO VALLEY. HENCE...THE AMOUNT OF FORCING FOR THUNDERSTORMS WILL BE SOMEWHAT LESS WITH SOME DEGREE OF SYNOPTIC SUBSIDENCE. HOWEVER...FORECAST SOUNDINGS SHOW CIN ERODING IN THE AFTERNOON TO WHERE WE EXPECT A FEW UPDRAFTS TO BREAK THE CAP. HENCE...WILL CARRY ISOLATED TO SCATTERED POPS OVER THE MOUNTAINS AND THE SOUTHERN PIEDMONT. THE OTHER CONCERN WILL CONTINUE TO BE THE HEAT. HAVE GONE ON THE HIGH END OF THE GUIDANCE ENVELOPE FOR MAX TEMPS ON FRIDAY WHICH IS WHAT THE THICKNESS WOULD SUPPORT. DEWPOINTS WILL TRY TO MIX OUT SOME DURING THE AFTERNOON...BUT PROBABLY NOT ENOUGH TO PRECLUDE AN HOUR OR TWO OF APPARENT TEMPS REACHING 105 ACROSS PARTS OF THE UPSTATE. IF CURRENT NUMBERS HOLD...MAY HAVE TO CONSIDER A HEAT ADVISORY FOR PARTS OF NE GA...UPSTATE SC AND PERHAPS THE CLT AREA. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... AS OF 145 PM WEDNESDAY...THE BIG STORY OF THE SHORT TERM PERIOD WILL BE THE SIGNIFICANT PATTERN CHANGE THAT IS ANTICIPATED...AS A SIGNIFICANT SHORT WAVE DIVES OUT OF THE NORTHERN CONUS...AND CARVES OUT A LONG WAVE TROUGH ACROSS THE EASTERN CONUS BY THE START OF THE WEEKEND. SURFACE LOW PRESSURE TRACKING ALONG THE ASSOCIATED FRONTAL ZONE...FROM THE TENN TO THE OHIO VALLEY IS EXPECTED TO ACTIVATE A PSEUDO-WARM FRONT/E-W ORIENTED CONVERGENCE ZONE ACROSS THE REGION ON FRIDAY...AND THIS COULD ACT AS AN ADDITIONAL FOCUS FOR CONVECTIVE INITIATION ACROSS OUR AREA FRI AFTERNOON. HOWEVER...THERE ARE QUITE A FEW MIXED SIGNALS IN THE GUIDANCE REGARDING HOW WIDESPREAD ANY CONVECTION WILL BE DURING THE AFTERNOON. THE HIGHEST POPS (LIKELY) WILL BE FOCUSED ACROSS THE NORTHERN ZONES...WHERE A MODEL CONSENSUS SUGGESTS THE CONVERGENCE ZONE WILL RESIDE DURING PEAK HEATING...AND ACROSS THE HIGH TERRAIN...WHERE THE COMBINATION OF TERRAIN EFFECTS AND INCREASED CONVERGENCE SHOULD RESULT IN HIGHER THAN NORMAL COVERAGE. DESPITE IMPROVING MID/UPPER FLOW RESPONDING TO HEIGHT FALLS...SHEAR MAGNITUDE WILL REMAIN QUITE WEAK OWING TO UNIDIRECTIONAL PROFILES. NEVERTHELESS...A FEW SEVERE STORMS WILL BE POSSIBLE. WITH HEIGHTS CONTINUING TO FALL AND AN APPROACHING FRONTAL ZONE... GOOD CHANCES FOR CONVECTION ARE EXPECTED TO CONTINUE WELL INTO FRI NIGHT...AND LIKELY POPS WILL ACTUALLY BE CARRIED THROUGH THE OVERNIGHT HOURS...DUE TO THE POTENTIAL FOR PRE-FRONTAL CONVECTION MOVING INTO THE FORECAST AREA...BUT ALSO DUE TO DEVELOPMENT OF AN ANOMALOUSLY STRONG W/SW LOW LEVEL FLOW...WHICH COULD ALLOW FOR SOME TERRAIN-INDUCED CONVECTION. SATURDAY WILL FEATURE AMPLE GOOD SOURCES OF LIFT...WITH LOW LEVEL CONVERGENCE ALONG THE FRONT...AND AN UPPER PATTERN SUPPORTIVE OF UVV. HOWEVER...SATURDAY WILL BE THE MOST STABLE DAY OF THE WEEK AS WELL...OWING TO THE LIKELIHOOD OF ABUNDANT MORNING CLOUD COVER AND DEEP MOIST ADIABATIC LAPSE RATES. ON THE OTHER HAND...SHEAR WILL BE RATHER IMPRESSIVE FOR LATE JUNE...ABOUT 30 KTS THROUGH A DEEP LAYER. SOME UPSCALE ORGANIZATION COULD THEREFORE OCCUR IF POCKETS OF MORE ROBUST INSTABILITY CAN BE REALIZED. LIKELY POPS WILL BE CARRIED ACROSS THE MAJORITY OF THE AREA SAT AFTERNOON. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 3 AM WEDNESDAY...SIGNIFICANT PATTERN CHANGE WILL SETTLE OVER THE REGION THIS WEEKEND AND SHOULD REMAIN THROUGH THE EXTENDED PERIOD. MODELS INDICATE THAT THE AXIS OF A L/W TROUGH WILL SWEEP ACROSS THE REGION THIS WEEKEND...WITH A SECONDARY WAVE EXPECTED TO CROSS THE APPALACHIANS ON TUESDAY. AT THE SFC...THE CENTER OF A DEEPENING LOW WILL MOVE FROM THE OHIO RIVER VALLEY ON SATURDAY TO SOUTHERN NY BY SUNDAY EVENING. A COLD FRONT SHOULD PUSH ACROSS THE REGION LATE SATURDAY AFTERNOON AND EVENING. THE ENVIRONMENT AHEAD OF THE FRONT WILL FEATURE WIDESPREAD INSTABILITY AND WEAK SHEAR...POSSIBLY SUPPORTING A BAND OF TSRA SAT AFTERNOON. I WILL FORECAST CATE COVERAGE NEAR THE TN LINE...WITH GENERALLY LIKELY POPS ACROSS THE REST OF THE CWA. DRIER AIR WILL BUILD ACROSS THE REGION ON SUNDAY...RESULTING IN FALLING POP VALUES. I WILL FORECAST PRIMARILY DIURNAL POPS ACROSS THE REGION MON AND TUES. TEMPERATURES THROUGH THE EXTENDED ARE FORECAST TO RANGE FROM BELOW NORMAL THIS WEEKEND TO NEAR NORMAL BY TUESDAY. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... AT KCLT...A WEAK FRONTAL TROUGH IN THE VICINTY OF THE AIRFIELD WILL SERVE TO TRIGGER SCT TSRA AS AIRMASS IS QUITE UNSTABLE THIS AFTERNOON. HENCE...WILL CARRY A TEMPO TSRA FROM 21-23Z THIS AFTERNOON. OTHERWISE...VFR CUMULUS WILL DISSIPATE AFTER SUNSET. ELSEWHERE...AIRMASS IS QUITE UNSTABLE OUTSIDE THE MOUNTAINS THIS AFTERNOON ALONG WITH A WEAK FRONTAL TROUGH EXTENDING FROM WESTERN NC...THROUGH UPSTATE SC INTO NE GA. SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP BY MID AFTERNOON. CAMS FAVOR WESTERN AREAS WITH THE BEST COVERAGE...SO WILL CARRY A TEMPO TSRA AT KAND. WILL MENTION VCTS AT GSP AND GMU. THE CHANCE OF TSRA TOO LOW TO MENTION AT AVL AND HKY. EXPECT SOME FOG FORMATION EARLY THURSDAY MORNING WITH GUIDNACE SUGGESTING MVFR RESTRICTIONS AT AVL AND HKY. OUTLOOK...TSTM CHANCES WILL INCREASE LATE IN THE WEEK INTO THE WEEKEND AS A COLD FRONT EVENTUALLY APPROACHES FROM THE NW. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE...PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY...AND IN THE MOUNTAIN RIVER VALLEYS. BEHIND THE COLD FRONT...A MUCH DRYER AND COOLER AIRMASS WILL OVERSPREAD THE REGION ON SUNDAY. CONFIDENCE TABLE... 19-01Z 01-07Z 07-13Z 13-18Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 86% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 96% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 93% HIGH 100% KGMU HIGH 86% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 93% 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 && .CLIMATE... RECORD MAXIMUM TEMPERATURES FOR THIS WEEK...WITH YEARS IN WHICH THE VALUES WERE LAST REACHED. WEDNESDAY JUNE 24... AVL 94 1952 CLT 102 1930 GSP 100 1952 THURSDAY JUNE 25... AVL 96 1952 CLT 102 1914 GSP 101 1952 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...LEV NEAR TERM...LG SHORT TERM...JDL LONG TERM...JP/LEV AVIATION...LG CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
707 AM EDT WED JUN 24 2015 .SYNOPSIS... STRONG MID LEVEL HIGH PRESSURE WILL PERSIST ACROSS THE REGION THROUGH THE REMAINDER OF THE WORK WEEK...MAINTAINING WELL ABOVE NORMAL TEMPERATURES. A BROAD UPPER LEVEL TROF WILL MOVE OVER THE REGION OVER THE WEEKEND RETURNING TEMPERATURES TO SEASONAL LEVELS BY SUNDAY AND INCREASING CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS. A COOLER AND DRIER PATTERN WILL TAKE SHAPE AFTER A FRONT PASSES EARLY IN THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 700 AM EDT...DEBRIS CLOUDS HAVE KEPT ANY MORNING VALLEY FOG TO A MINIMUM. OTHERWISE...THE WEAK SURFACE FRONTAL BOUNDARY IS FORECAST TO STALL OVER THE FORECAST AREA TODAY AND THEN GRADUALLY LIFT NORTHWARD AS A WARM FRONT TONIGHT. THE HRRR CONTINUES TO TREND TOWARD BETTER TSTM COVERAGE IN SRN SECTIONS THIS AFTN...SOUTH OF THE BOUNDARY. MODEL PROFILES REMAIN FAIRLY WARM ALOFT...HOWEVER...SEVERE WEATHER WILL BE A THREAT WITH ANY TSTMS THAT FORM AS MODERATE OR BETTER CAPE LOOKS LIKELY ALONG WITH MID LEVEL DRY AIR AND ASSOCIATED THETA E LAPSES YIELDING SOME MEASURE OF MICROBURST POTENTIAL. THE SRN HALF WILL BE MOST AT RISK GIVEN THE BOUNDARY LOCATION AND LIKELY SBCAPE VALUES OF 3000 TO 3500 J/KG THERE DURING PEAK HEATING. TEMPERATURES AND ASSOCIATED HEAT INDEX VALUES WILL BE THE OTHER ISSUE FOR THE FORECAST TODAY. BL AND 850 TEMPS LOOK COMPARABLE TO YESTERDAY...BUT SO DOES THE POTENTIAL FOR SOME DEWPOINT MIXING IN THE WARMEST PIEDMONT SECTIONS. PLUS...THERE COULD BE DEBRIS CLOUDS AROUND AT TIMES TODAY. WILL KEEP HEAT INDEX VALUES IN THE SRN PIEDMONT AT 100 TO 104 THIS AFTN. ANTICIPATE ANOTHER VERY MILD NIGHT WITH PRECIPITATION CHANCES STEADILY WANING WITH THE LOSS OF HEATING. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... AS OF 245 AM WEDNESDAY...ON THURSDAY...THE H5 AND H7 RIDGE WILL REMAIN CENTERED OVER THE DEEP SOUTH. HOWEVER...HEIGHTS SHOULD RISE FROM THE SOUTH AS THE RIDGE CENTER DRIFTS EAST DURING THE DAY. USING A BLEND OF PREFERRED GUIDANCE...I WILL FORECAST HIGHS AROUND 90 WITHIN THE MTN VALLEYS TO MID TO HIGH 90S ACROSS THE FOOTHILLS AND PIEDMONT. A WEST TO EAST FRONT WILL REMAIN ACROSS THE OHIO RIVER VALLEYS AS A SFC TROF COVERS THE FOOTHILLS AND PIEDMONT. GIVEN THE SFC PATTERN...LLVL WINDS ARE FORECAST TO REMAIN LIGHT FROM THE WSW. FORECAST SOUNDINGS REVEAL THAT A SIGNIFICANT LAYER OF CIN WILL REMAIN AROUND H75...VALUES RANGING FROM 40-60 J/KG. THE LACK OF FORCING AND LINGERING CAPPING SHOULD FAVOR LITTLE TO NO COVERAGE OF DEEP CONVECTION ON THURSDAY. I WILL FORECAST DRY CONDITIONS EAST OF THE MTNS...WITH SCHC OVER THE RIDGES. ON FRIDAY...SHORT RANGE MODELS INDICATE THAT A WEAK MID LEVEL LOW WILL LINGER NEAR THE GA/FL LINE DURING THE DAY. IN ADDITION...A POSITIVE TILTED L/W TROF WILL BEGIN TO AMPLIFY ACROSS THE MID WEST...SLIDING EAST. AT THE SFC...A BROAD AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS THE CAROLINAS AS A SFC FRONT STALLS OVER THE REGION. FORECAST SOUNDINGS INDICATE THAT MOISTURE WILL SURGE ACROSS THE REGION...WITH PW VALUES OVER 2 INCHES BY THE AFTERNOON. THE MOISTURE COMBINED WITH WELL ABOVE AVERAGE HIGH TEMPERATURES SHOULD YIELD WIDESPREAD MODERATE VALUES OF CAPE. GIVEN THE BROAD AREA OF LLVL MOISTURE CONVERGENCE...INSTABILITY...AND INCREASING MID LEVEL FORCING...TSRA COVERAGE WILL INCREASE SIGNIFICANTLY FROM THURSDAY. I WILL FORECAST LIKELY POPS ACROSS THE MTNS WITH VALUES IN THE 40 TO 50 RANGE EAST. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY...SIGNIFICANT PATTERN CHANGE WILL SETTLE OVER THE REGION THIS WEEKEND AND SHOULD REMAIN THROUGH THE EXTENDED PERIOD. MODELS INDICATE THAT THE AXIS OF A L/W TROUGH WILL SWEEP ACROSS THE REGION THIS WEEKEND...WITH A SECONDARY WAVE EXPECTED TO CROSS THE APPALACHIANS ON TUESDAY. AT THE SFC...THE CENTER OF A DEEPENING LOW WILL MOVE FROM THE OHIO RIVER VALLEY ON SATURDAY TO SOUTHERN NY BY SUNDAY EVENING. A COLD FRONT SHOULD PUSH ACROSS THE REGION LATE SATURDAY AFTERNOON AND EVENING. THE ENVIRONMENT AHEAD OF THE FRONT WILL FEATURE WIDESPREAD INSTABILITY AND WEAK SHEAR...POSSIBLY SUPPORTING A BAND OF TSRA SAT AFTERNOON. I WILL FORECAST CATE COVERAGE NEAR THE TN LINE...WITH GENERALLY LIKELY POPS ACROSS THE REST OF THE CWA. DRIER AIR WILL BUILD ACROSS THE REGION ON SUNDAY...RESULTING IN FALLING POP VALUES. I WILL FORECAST PRIMARILY DIURNAL POPS ACROSS THE REGION MON AND TUES. TEMPERATURES THROUGH THE EXTENDED ARE FORECAST TO RANGE FROM BELOW NORMAL THIS WEEKEND TO NEAR NORMAL BY TUESDAY. && .AVIATION /11Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...A WEAK FRONT SAGGING SOUTH ACROSS THE TERMINAL AREA THIS MORNING WILL TOGGLE SURFACE WINDS TO NE LATE MORNING THROUGH THE AFTN. PRECIPITATION CHANCES LOOK RATHER SMALL AROUND THE AIRFIELD GIVEN THE WARM PROFILES ALOFT...BUT ANY CONVECTION THAT FORMS WILL BE STRONG. VFR CONDITIONS WILL CONTINUE WITH HIGH BASED CUMULUS FORMING AND BEING TOPPED BY TEMPO HIGH CLOUD DEBRIS CIGS FROM TIME TO TIME. ELSEWHERE...CONVECTIVE CHANCES REMAIN GREATEST AT KAVL THIS AFTN DUE TO TERRAIN FLOW AND LOW LEVEL CONVERGENCE...BUT A TSRA CANNOT BE RULED OUT ACROSS THE UPSTATE SITES WHERE INSTABILITY WILL BE THE GREATEST. ANY TSRA WOULD BE QUITE STRONG WITH THE POTENTIAL FOR GUSTY WINDS GIVEN THE MID LEVEL DRY AIR. EXPECT SFC WINDS TO TOGGLE NW THEN NE THROUGH THE DAY BEFORE TURNING AROUND THE DIAL TO SE LATE. THE BEST CHANCE FOR RESTRICTIONS EARLY THU MORNING WILL BE IN THE MTN VALLEYS...BUT WILL CONFINE THE FOG TO MVFR AT KAVL FOR NOW. OUTLOOK...SCT DIURNAL TSTM CHANCES WILL INCREASE LATE WEEK INTO THE WEEKEND AS A COLD FRONT EVENTUALLY APPROACHES FROM THE NW. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE...PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY...AND IN THE MOUNTAIN RIVER VALLEYS. CONFIDENCE TABLE... 11-17Z 17-23Z 23-05Z 05-06Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 94% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% 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 && .CLIMATE... RECORD MAXIMUM TEMPERATURES FOR THIS WEEK...WITH YEARS IN WHICH THE VALUES WERE LAST REACHED. WEDNESDAY JUNE 24... AVL 94 1952 CLT 102 1930 GSP 100 1952 THURSDAY JUNE 25... AVL 96 1952 CLT 102 1914 GSP 101 1952 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...NED NEAR TERM...HG SHORT TERM...NED LONG TERM...NED AVIATION...HG CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
452 AM EDT WED JUN 24 2015 .SYNOPSIS... STRONG MID LEVEL HIGH PRESSURE WILL PERSIST ACROSS THE REGION THROUGH THE REMAINDER OF THE WORK WEEK...MAINTAINING WELL ABOVE NORMAL TEMPERATURES. A BROAD UPPER LEVEL TROF WILL MOVE OVER THE REGION OVER THE WEEKEND RETURNING TEMPERATURES TO SEASONAL LEVELS BY SUNDAY AND INCREASING CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS. A COOLER AND DRIER PATTERN WILL TAKE SHAPE AFTER A FRONT PASSES EARLY IN THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 445 AM EDT...THE LATEST HRRR RUNS ALLOW ANY LINGERING ERN TN CONVECTION TO DIMINISH OVER THE WESTERN MOUNTAINS THROUGH DAYBREAK. OTHERWISE...THE WEAK SURFACE FRONTAL BOUNDARY WILL STALL IN THE FORECAST AREA TODAY AND THEN LIKELY LIFT NORTHWARD AS A WARM FRONT TONIGHT. THE HRRR HAS ALSO TRENDED TOWARD BETTER TSTM COVERAGE IN SRN SECTIONS THIS AFTN...SOUTH OF THE BOUNDARY. MODEL PROFILES REMAIN FAIRLY WARM ALOFT...HOWEVER...SEVERE WEATHER WILL BE A THREAT WITH ANY TSTMS THAT FORM AS MODERATE OR BETTER CAPE LOOKS LIKELY ALONG WITH MID LEVEL DRY AIR AND ASSOCIATED THETA E LAPSES YIELDING SOME MEASURE OF MICROBURST POTENTIAL. THE SRN HALF WILL BE MOST AT RISK GIVEN THE BOUNDARY LOCATION AND LIKELY SBCAPE VALUES OF 3000 TO 3500 J/KG THERE DURING PEAK HEATING. TEMPERATURES AND ASSOCIATED HEAT INDEX VALUES WILL BE THE OTHER ISSUE FOR THE FORECAST TODAY. BL AND 850 TEMPS LOOK COMPARABLE TO YESTERDAY...BUT SO DOES THE POTENTIAL FOR SOME DEWPOINT MIXING IN THE WARMEST PIEDMONT SECTIONS. PLUS...THERE COULD BE DEBRIS CLOUDS AROUND AT TIMES TODAY. WILL KEEP HEAT INDEX VALUES IN THE SRN PIEDMONT AT 100 TO 104 THIS AFTN. ANTICIPATE ANOTHER VERY MILD NIGHT WITH PRECIPITATION CHANCES STEADILY WANING WITH THE LOSS OF HEATING. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... AS OF 245 AM WEDNESDAY...ON THURSDAY...THE H5 AND H7 RIDGE WILL REMAIN CENTERED OVER THE DEEP SOUTH. HOWEVER...HEIGHTS SHOULD RISE FROM THE SOUTH AS THE RIDGE CENTER DRIFTS EAST DURING THE DAY. USING A BLEND OF PREFERRED GUIDANCE...I WILL FORECAST HIGHS AROUND 90 WITHIN THE MTN VALLEYS TO MID TO HIGH 90S ACROSS THE FOOTHILLS AND PIEDMONT. A WEST TO EAST FRONT WILL REMAIN ACROSS THE OHIO RIVER VALLEYS AS A SFC TROF COVERS THE FOOTHILLS AND PIEDMONT. GIVEN THE SFC PATTERN...LLVL WINDS ARE FORECAST TO REMAIN LIGHT FROM THE WSW. FORECAST SOUNDINGS REVEAL THAT A SIGNIFICANT LAYER OF CIN WILL REMAIN AROUND H75...VALUES RANGING FROM 40-60 J/KG. THE LACK OF FORCING AND LINGERING CAPPING SHOULD FAVOR LITTLE TO NO COVERAGE OF DEEP CONVECTION ON THURSDAY. I WILL FORECAST DRY CONDITIONS EAST OF THE MTNS...WITH SCHC OVER THE RIDGES. ON FRIDAY...SHORT RANGE MODELS INDICATE THAT A WEAK MID LEVEL LOW WILL LINGER NEAR THE GA/FL LINE DURING THE DAY. IN ADDITION...A POSITIVE TILTED L/W TROF WILL BEGIN TO AMPLIFY ACROSS THE MID WEST...SLIDING EAST. AT THE SFC...A BROAD AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS THE CAROLINAS AS A SFC FRONT STALLS OVER THE REGION. FORECAST SOUNDINGS INDICATE THAT MOISTURE WILL SURGE ACROSS THE REGION...WITH PW VALUES OVER 2 INCHES BY THE AFTERNOON. THE MOISTURE COMBINED WITH WELL ABOVE AVERAGE HIGH TEMPERATURES SHOULD YIELD WIDESPREAD MODERATE VALUES OF CAPE. GIVEN THE BROAD AREA OF LLVL MOISTURE CONVERGENCE...INSTABILITY...AND INCREASING MID LEVEL FORCING...TSRA COVERAGE WILL INCREASE SIGNIFICANTLY FROM THURSDAY. I WILL FORECAST LIKELY POPS ACROSS THE MTNS WITH VALUES IN THE 40 TO 50 RANGE EAST. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY...SIGNIFICANT PATTERN CHANGE WILL SETTLE OVER THE REGION THIS WEEKEND AND SHOULD REMAIN THROUGH THE EXTENDED PERIOD. MODELS INDICATE THAT THE AXIS OF A L/W TROUGH WILL SWEEP ACROSS THE REGION THIS WEEKEND...WITH A SECONDARY WAVE EXPECTED TO CROSS THE APPALACHIANS ON TUESDAY. AT THE SFC...THE CENTER OF A DEEPENING LOW WILL MOVE FROM THE OHIO RIVER VALLEY ON SATURDAY TO SOUTHERN NY BY SUNDAY EVENING. A COLD FRONT SHOULD PUSH ACROSS THE REGION LATE SATURDAY AFTERNOON AND EVENING. THE ENVIRONMENT AHEAD OF THE FRONT WILL FEATURE WIDESPREAD INSTABILITY AND WEAK SHEAR...POSSIBLY SUPPORTING A BAND OF TSRA SAT AFTERNOON. I WILL FORECAST CATE COVERAGE NEAR THE TN LINE...WITH GENERALLY LIKELY POPS ACROSS THE REST OF THE CWA. DRIER AIR WILL BUILD ACROSS THE REGION ON SUNDAY...RESULTING IN FALLING POP VALUES. I WILL FORECAST PRIMARILY DIURNAL POPS ACROSS THE REGION MON AND TUES. TEMPERATURES THROUGH THE EXTENDED ARE FORECAST TO RANGE FROM BELOW NORMAL THIS WEEKEND TO NEAR NORMAL BY TUESDAY. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...EXPECT MAINLY LIGHT SW TO WSW FLOW EARLY THIS MORNING AS A WEAK FRONT SAGS SOUTH TOWARD THE TERMINAL...WITH FLOW TOGGLING NW AND THEN NE TODAY BEHIND THE BOUNDARY. PRECIPITATION CHANCES LOOK RATHER SMALL AROUND THE AIRFIELD GIVEN THE WARM PROFILES ALOFT...BUT ANY CONVECTION THAT FORMS WILL BE STRONG. VFR CONDITIONS WILL CONTINUE WITH HIGH BASED CUMULUS FORMING AND BEING TOPPED BY TEMPO HIGH CLOUD DEBRIS CIGS FROM TIME TO TIME. ELSEWHERE...CONVECTIVE CHANCES REMAIN GREATEST AT KAVL THIS AFTN DUE TO TERRAIN FLOW AND LOW LEVEL CONVERGENCE...BUT A TSRA CANNOT BE RULED OUT ACROSS THE UPSTATE SITES WHERE INSTABILITY WILL BE THE GREATEST. ANY TSRA WOULD BE QUITE STRONG WITH THE POTENTIAL FOR GUSTY WINDS GIVEN THE MID LEVEL DRY AIR. EXPECT SFC WINDS TO TOGGLE NW THEN NE THROUGH THE DAY BEFORE TURNING AROUND THE DIAL TO SE LATE. THE BEST CHANCE FOR DAYBREAK RESTRICTIONS WILL BE IN THE MTN VALLEYS...BUT WILL CONFINE THE FOG TO MVFR AT KAVL FOR NOW. OUTLOOK...SCT DIURNAL TSTM CHANCES WILL INCREASE LATE WEEK INTO THE WEEKEND AS A FRONT EVENTUALLY APPROACHES FROM THE NW. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE...PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY...AND IN THE MOUNTAIN RIVER VALLEYS. CONFIDENCE TABLE... 09-15Z 15-21Z 21-03Z 03-06Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 88% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 91% 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 && .CLIMATE... RECORD MAXIMUM TEMPERATURES FOR THIS WEEK...WITH YEARS IN WHICH THE VALUES WERE LAST REACHED. WEDNESDAY JUNE 24... AVL 94 1952 CLT 102 1930 GSP 100 1952 THURSDAY JUNE 25... AVL 96 1952 CLT 102 1914 GSP 101 1952 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...NED NEAR TERM...HG/WJM SHORT TERM...NED LONG TERM...NED AVIATION...HG CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
307 AM EDT WED JUN 24 2015 .SYNOPSIS... STRONG MID LEVEL HIGH PRESSURE WILL PERSIST ACROSS THE REGION THROUGH THE REMAINDER OF THE WORK WEEK...MAINTAINING WELL ABOVE NORMAL TEMPERATURES. A BROAD UPPER LEVEL TROF WILL MOVE OVER THE REGION OVER THE WEEKEND RETURNING TEMPERATURES TO SEASONAL LEVELS BY SUNDAY AND INCREASING CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS. A COOLER AND DRIER PATTERN WILL TAKE SHAPE AFTER A FRONT PASSES EARLY IN THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 250 AM EDT...THE LATEST HRRR RUNS ALLOW LINGERING EARLY MORNING DECAYING CONVECTION TO PASS MAINLY NE OF THE AREA ALONG THE FRONTAL BOUNDARY DROPPING SWD...AND ALSO W OF THE AREA WITH CONVECTION FANNING OUT IN THE BETTER INSTABILITY ACROSS SRN TN AND INTO THE DEEP SOUTH OVERNIGHT. LITTLE MORE THAN AN ISOLD TO SCT EARLY MORNING SHRA/TSRA MENTION WILL BE NEEDED ALONG THE SPINE OF THE SOUTHERN APPALACHIANS. OTHERWISE...THE WEAK SURFACE FRONTAL BOUNDARY WILL STALL IN THE FORECAST AREA TODAY AND THEN LIKELY LIFT NORTHWARD AS A WARM FRONT TONIGHT. THE NUMERICAL MODELS HAVE SURPRISINGLY LITTLE CONVECTION FIRING OVER THE FORECAST AREA THIS AFTN GIVEN THE BOUNDARY IN THE REGION. THIS APPEARS TO BE DUE TO WARM PROFILES ALOFT AND NEGATIVE AREA IN MODEL SOUNDINGS. HOWEVER...SEVERE WEATHER WILL BE A THREAT WITH ANY TSTMS THAT FORM AS MODERATE OR BETTER CAPE LOOKS LIKELY ALONG WITH MID LEVEL DRY AIR AND ASSOCIATED THETA E LAPSES YIELDING SOME MEASURE OF MICROBURST POTENTIAL. THE SRN HALF WILL BE MOST AT RISK GIVEN THE BOUNDARY LOCATION AND LIKELY SBCAPE VALUES OF 3000 TO 3500 J/KG THERE DURING PEAK HEATING. TEMPERATURES AND ASSOCIATED HEAT INDEX VALUES WILL BE THE OTHER ISSUE FOR THE FORECAST TODAY. BL AND 850 TEMPS LOOK COMPARABLE TO YESTERDAY...BUT SO DOES THE POTENTIAL FOR SOME DEWPOINT MIXING IN THE WARMEST PIEDMONT SECTIONS. PLUS...THERE COULD BE CONSIDERABLE DEBRIS CLOUDS AROUND AT TIMES TODAY. WILL KEEP HEAT INDEX VALUES IN THE SRN PIEDMONT AT 100 TO 104 THIS AFTN. ANTICIPATE ANOTHER VERY MILD NIGHT WITH PRECIPITATION CHANCES STEADILY WANING WITH THE LOSS OF HEATING. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... AS OF 245 AM WEDNESDAY...ON THURSDAY...THE H5 AND H7 RIDGE WILL REMAIN CENTERED OVER THE DEEP SOUTH. HOWEVER...HEIGHTS SHOULD RISE FROM THE SOUTH AS THE RIDGE CENTER DRIFTS EAST DURING THE DAY. USING A BLEND OF PREFERRED GUIDANCE...I WILL FORECAST HIGHS AROUND 90 WITHIN THE MTN VALLEYS TO MID TO HIGH 90S ACROSS THE FOOTHILLS AND PIEDMONT. A WEST TO EAST FRONT WILL REMAIN ACROSS THE OHIO RIVER VALLEYS AS A SFC TROF COVERS THE FOOTHILLS AND PIEDMONT. GIVEN THE SFC PATTERN...LLVL WINDS ARE FORECAST TO REMAIN LIGHT FROM THE WSW. FORECAST SOUNDINGS REVEAL THAT A SIGNIFICANT LAYER OF CIN WILL REMAIN AROUND H75...VALUES RANGING FROM 40-60 J/KG. THE LACK OF FORCING AND LINGERING CAPPING SHOULD FAVOR LITTLE TO NO COVERAGE OF DEEP CONVECTION ON THURSDAY. I WILL FORECAST DRY CONDITIONS EAST OF THE MTNS...WITH SCHC OVER THE RIDGES. ON FRIDAY...SHORT RANGE MODELS INDICATE THAT A WEAK MID LEVEL LOW WILL LINGER NEAR THE GA/FL LINE DURING THE DAY. IN ADDITION...A POSITIVE TILTED L/W TROF WILL BEGIN TO AMPLIFY ACROSS THE MID WEST...SLIDING EAST. AT THE SFC...A BROAD AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS THE CAROLINAS AS A SFC FRONT STALLS OVER THE REGION. FORECAST SOUNDINGS INDICATE THAT MOISTURE WILL SURGE ACROSS THE REGION...WITH PW VALUES OVER 2 INCHES BY THE AFTERNOON. THE MOISTURE COMBINED WITH WELL ABOVE AVERAGE HIGH TEMPERATURES SHOULD YIELD WIDESPREAD MODERATE VALUES OF CAPE. GIVEN THE BROAD AREA OF LLVL MOISTURE CONVERGENCE...INSTABILITY...AND INCREASING MID LEVEL FORCING...TSRA COVERAGE WILL INCREASE SIGNIFICANTLY FROM THURSDAY. I WILL FORECAST LIKELY POPS ACROSS THE MTNS WITH VALUES IN THE 40 TO 50 RANGE EAST. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY...SIGNIFICANT PATTERN CHANGE WILL SETTLE OVER THE REGION THIS WEEKEND AND SHOULD REMAIN THROUGH THE EXTENDED PERIOD. MODELS INDICATE THAT THE AXIS OF A L/W TROUGH WILL SWEEP ACROSS THE REGION THIS WEEKEND...WITH A SECONDARY WAVE EXPECTED TO CROSS THE APPALACHIANS ON TUESDAY. AT THE SFC...THE CENTER OF A DEEPENING LOW WILL MOVE FROM THE OHIO RIVER VALLEY ON SATURDAY TO SOUTHERN NY BY SUNDAY EVENING. A COLD FRONT SHOULD PUSH ACROSS THE REGION LATE SATURDAY AFTERNOON AND EVENING. THE ENVIRONMENT AHEAD OF THE FRONT WILL FEATURE WIDESPREAD INSTABILITY AND WEAK SHEAR...POSSIBLY SUPPORTING A BAND OF TSRA SAT AFTERNOON. I WILL FORECAST CATE COVERAGE NEAR THE TN LINE...WITH GENERALLY LIKELY POPS ACROSS THE REST OF THE CWA. DRIER AIR WILL BUILD ACROSS THE REGION ON SUNDAY...RESULTING IN FALLING POP VALUES. I WILL FORECAST PRIMARILY DIURNAL POPS ACROSS THE REGION MON AND TUES. TEMPERATURES THROUGH THE EXTENDED ARE FORECAST TO RANGE FROM BELOW NORMAL THIS WEEKEND TO NEAR NORMAL BY TUESDAY. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...EXPECT MAINLY LIGHT SW TO WSW FLOW EARLY THIS MORNING AS A WEAK FRONT SAGS SOUTH TOWARD THE TERMINAL...WITH FLOW TOGGLING NW AND THEN NE TODAY BEHIND THE BOUNDARY. PRECIPITATION CHANCES CONTINUE TO LOOK SMALL AROUND THE AIRFIELD GIVEN THE WARM PROFILES ALOFT...BUT ANY CONVECTION THAT FORMS WILL BE STRONG. VFR CONDITIONS WILL CONTINUE WITH HIGH BASED CUMULUS FORMING AND BEING TOPPED BY TEMPO HIGH CLOUD DEBRIS CIGS FROM TIME TO TIME. ELSEWHERE...CONVECTIVE CHANCES REMAIN GREATEST AT KAVL THIS AFTN DUE TO TERRAIN FLOW AND LOW LEVEL CONVERGENCE...BUT A TSRA CANNOT BE RULED OUT ACROSS THE UPSTATE SITES WHERE INSTABILITY WILL BECOME THE GREATEST. ANY TSRA WOULD BE QUITE STRONG WITH THE POTENTIAL FOR GUSTY WINDS GIVEN THE MID LEVEL DRY AIR. EXPECT SFC WINDS TO TOGGLE NW THEN NE THROUGH THE DAY BEFORE TURNING AROUND THE DIAL TO SE LATE. THE BEST CHANCE FOR DAYBREAK RESTRICTIONS WILL BE IN THE MTN VALLEYS...BUT WILL CONFINE THE FOG TO MVFR AT KAVL FOR NOW. OUTLOOK...SCT DIURNAL TSTM CHANCES WILL INCREASE LATE WEEK INTO THE WEEKEND AS A FRONT EVENTUALLY APPROACHES FROM THE NW. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE...PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY...AND IN THE MOUNTAIN RIVER VALLEYS. CONFIDENCE TABLE... 07-13Z 13-19Z 19-01Z 01-06Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 96% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 95% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 93% 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 && .CLIMATE... RECORD MAXIMUM TEMPERATURES FOR THIS WEEK...WITH YEARS IN WHICH THE VALUES WERE LAST REACHED. WEDNESDAY JUNE 24... AVL 94 1952 CLT 102 1930 GSP 100 1952 THURSDAY JUNE 25... AVL 96 1952 CLT 102 1914 GSP 101 1952 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...LEV/NED NEAR TERM...HG/WJM SHORT TERM...NED LONG TERM...NED AVIATION...HG CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
229 AM EDT WED JUN 24 2015 .SYNOPSIS... STRONG MID LEVEL HIGH PRESSURE WILL PERSIST ACROSS THE REGION THROUGH THE REMAINDER OF THE WORK WEEK...MAINTAINING WELL ABOVE NORMAL TEMPERATURES. A BROAD UPPER LEVEL TROF WILL MOVE OVER THE REGION OVER THE WEEKEND RETURNING TEMPERATURES TO SEASONAL LEVELS BY SUNDAY AND INCREASING CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS. A COOLER AND DRIER PATTERN WILL TAKE SHAPE AFTER A FRONT PASSES EARLY IN THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 210 AM EDT...THE LATEST HRRR RUNS ALLOW CONVECTION TO PASS MAINLY NE OF THE AREA ALONG THE FRONTAL BOUNDARY DROPPING SWD...AND ALSO W OF THE AREA WITH CONVECTION FANNING OUT IN THE BETTER INSTABILITY ACROSS SRN TN AND INTO THE DEEP SOUTH OVERNIGHT. LITTLE MORE THAN AN ISOLD TO SCT EARLY MORNING SHRA/TSRA MENTION WILL BE NEEDED ALONG THE SPINE OF THE SOUTHERN APPALACHIANS. OTHERWISE...A SURFACE FRONTAL BOUNDARY WILL STALL IN THE FORECAST AREA TODAY AND THEN LIKELY LIFT NORTHWARD AS A WARM FRONT TONIGHT. THE NUMERICAL MODELS HAVE SURPRISINGLY LITTLE CONVECTION FIRING OVER THE FORECAST AREA THIS AFTN GIVEN THE BOUNDARY IN THE REGION. THIS APPEARS TO BE DUE TO WARM PROFILES ALOFT AND NEGATIVE AREA IN MODEL SOUNDINGS. HOWEVER...SEVERE WEATHER WILL BE A THREAT WITH ANY TSTMS THAT FORM AS MODERATE OR BETTER CAPE LOOKS LIKELY ALONG WITH SOME MID LEVEL DRY AIR AND ASSOCIATED THETA E LAPSES YIELDING SOME MICROBURST POTENTIAL. THE SRN HALF WILL BE MOST AT RISK GIVEN THE BOUNDARY LOCATION AND LIKELY SBCAPE VALUES OF 3000 TO 3500 J/KG THERE DURING PEAK HEATING. TEMPERATURES AND ASSOCIATED HEAT INDEX VALUES WILL BE THE OTHER ISSUE FOR THE FORECAST TODAY. BL AND 850 TEMPS LOOK COMPARABLE TO YESTERDAY...BUT SO DOES THE POTENTIAL FOR SOME DEWPOINT MIXING IN THE WARMEST PIEDMONT SECTIONS. PLUS...THERE COULD BE CONSIDERABLE DEBRIS CLOUDS AROUND AT TIMES TODAY. WILL KEEP HEAT INDEX VALUES IN THE SRN PIEDMONT AT 100 TO 104 THIS AFTN. ANTICIPATE ANOTHER VERY MILD NIGHT WITH PRECIPITATION CHANCES STEADILY WANING WITH THE LOSS OF HEATING. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... AS OF 205 PM TUESDAY...SOME SUBTLE CHANGES OCCUR BY THE END OF THE SHORT TERM PERIOD WHICH WILL PORTEND AN EVENTUAL END TO THE ABNORMALLY HOT CONDITIONS THAT HAVE PREVAILED. HOWEVER PRIOR TO THAT...THE UPPER HIGH OVER THE TN VALLEY WILL CONTINUE TO NOSE EASTWARD INTO THE SOUTHERN APPALACHIANS AND WESTERN CAROLINAS WED NIGHT AND THEN SLOWLY WEAKEN AS IT SLIDES EASTWARD TO THE COAST BY EARLY FRIDAY. THIS IS IN REPONSE TO A SHORT WAVE TROUGH DIGGING SE INTO THE MIDWEST WHICH WILL BEGIN LOWERING HEIGHTS ACROSS THE SE STATES DURING FRIDAY. AT THE SURFACE...THE WEAK FRONTAL BOUNDARY IS FORECAST TO LIE FROM NEAR CLT...SW THROUGH GREENVILLE INTO NE GA WEDNESDAY EVENING. BOTH THE NAM AND GFS USE THIS BOUNDARY TO FIRE UP SOME WED EVENING CONVECTION. HENCE...WILL NEED TO ADDRESS THIS POSSIBILITY WITH SOME SCT TYPE POPS. BOTH THE NAM AND GFS ARE IN AGREEMENT THAT CONVECTIVE CHANCES WILL BE SUPRESSED ON THURSDAY AS THE WEAKENING UPPER HIGH SLIDES EAST INTO THE AREA. THE SYNOPTIC SUBSIDENCE ASSOCIATED WITH THE UPPER HIGH SHOULD SERVE TO LIMIT CONVECTION TO THE MOUNTAINS AND THAT MAY BE JUST ALONG THE BLUE RIDGE WHERE BEST DIFFERENTIAL HEATING SETS UP. MODEL SOUNDINGS INDICATE CONSIDERABLE CINH TO OVERCOME SO WILL LIMIT POPS TO WIDELY SCT OVER THE MOUNTAINS. IT WILL REMAIN QUITE HOT ON THURSDAY AND WILL TREND MAX TEMPERATURES TOWARD THE UPPER RANGE OF GUIDANCE WHICH MEANS MID TO UPPER 90S OUTSIDE THE MOUNTAINS. ON FRIDAY AS HEIGHTS BEGIN TO LOWER...WE SHOULD SEE A NOTABLE UPTICK IN CONVECTIVE COVERAGE. THEREFORE...WILL FEATURE SCT-NUMEROUS TYPE POPS WITH THE BEST COVERAGE OVER THE MOUNTAINS AND WESTERN AREAS. THE INCREASED CONVECTIVE COVERAGE SHOULD SERVE TO KEEP MAXIMUM TEMPERATURES IN CHECK SOMEWHAT. HOWEVER...IT WILL STILL BE QUITE WARM WITH THE HOTTEST TEMPS OVER THE I-77 CORRIDOR WHERE MID 90S ARE IN THE FORECAST. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 230 PM TUESDAY...THE BEGINNING OF THE MEDIUM RANGE FEATURES A PRONOUNCED TRANSITION IN THE SYNOPTIC PATTERN OVER THE CONUS. AN H5 TROUGH WILL DIG DEEP INTO THE SOUTHEAST ON SATURDAY...WITH A TRAIL OF SURFACE LOWS ROUNDING THE BASE OF THE TROUGH AND TRACKING THROUGH THE OHIO RIVER VALLEY. A FRONTAL BOUNDARY ASSOCIATED WITH A CLOSED SURFACE LOW ON THAT TRACK WILL APPROACH THE FORECAST AREA SATURDAY AND EARLY SUNDAY...BRINGING LIKELY POPS TO THE ENTIRE CWA. THE FRONT WILL PASS THE AREA BY LATE SUNDAY. THERE IS SOME DISCREPANCY IN THE AMOUNT OF CLEARING BEHIND THE FRONT...WITH THE ECMWF MAINTAINING MORE MOISTURE AFTER THE FRONTAL PASSAGE THAN THE DRY GFS. THE PATTERN DOES LOOK TO DRY OUT SOMEWHAT MONDAY AND TUESDAY AS A SURFACE HIGH BUILDS OVER THE SOUTHEAST...WITH POPS PEAKING DIURNALLY YET REMAINING JUST BELOW CLIMO THROUGH THE END OF THE EXTENDED PERIOD. THE EXTENDED PERIOD WILL BEGIN WITH MAX TEMPS JUST ABOVE CLIMO...AND WILL TAPER TO NEAR AVEAGE OVER THE WEEKEND. TEMPS WILL BE A CATEGORY OR TWO COOLER THAN THE SHORT TERM ON MONDAY AND TUESDAY AFTER THE FRONTAL PASSAGE. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...EXPECT MAINLY LIGHT SW TO WSW FLOW EARLY THIS MORNING AS A WEAK FRONT SAGS SOUTH INTO THE REGION...WITH FLOW TOGGLING NW AND THEN NE TODAY BEHIND THE BOUNDARY. PRECIPITATION CHANCES CONTINUE TO LOOK SMALL AROUND THE AIRFIELD GIVEN THE WARM PROFILES ALOFT...BUT ANY CONVECTION THAT FORMS WILL BE STRONG. VFR CONDITIONS WILL CONTINUE WITH HIGH BASED CUMULUS FORMING AND BEING TOPPED BY TEMPO HIGH CLOUD DEBRIS CIGS FROM TIME TO TIME. ELSEWHERE...CONVECTIVE CHANCES REMAIN GREATEST AT KAVL THIS AFTN DUE TO TERRAIN FLOW AND LOW LEVEL CONVERGENCE...BUT A TSRA CANNOT BE RULED OUT ACROSS THE UPSTATE SITES WHERE INSTABILITY WILL BECOME THE GREATEST. ANY TSRA WOULD BE QUITE STRONG WITH THE POTENTIAL FOR GUSTY WINDS GIVEN THE MID LEVEL DRY AIR. EXPECT SFC WINDS TO TOGGLE NW THEN NE THROUGH THE DAY BEFORE TURNING AROUND THE DIAL TO SE LATE. THE BEST CHANCE FOR DAYBREAK RESTRICTIONS WILL BE IN THE MTN VALLEYS...BUT WILL CONFINE IT TO MVFR AT KAVL FOR NOW. OUTLOOK...SCT DIURNAL TSTM CHANCES WILL INCREASE LATE WEEK INTO THE WEEKEND AS A FRONT EVENTUALLY APPROACHES FROM THE NW. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE...PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY...AND IN THE MOUNTAIN RIVER VALLEYS. CONFIDENCE TABLE... 06-12Z 12-18Z 18-24Z 00-06Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 91% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 94% 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 && .CLIMATE... RECORD MAXIMUM TEMPERATURES FOR THIS WEEK...WITH YEARS IN WHICH THE VALUES WERE LAST REACHED. WEDNESDAY JUNE 24... AVL 94 1952 CLT 102 1930 GSP 100 1952 THURSDAY JUNE 25... AVL 96 1952 CLT 102 1914 GSP 101 1952 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...LEV NEAR TERM...HG/WJM SHORT TERM...LG LONG TERM...JP/LEV AVIATION...HG CLIMATE...
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
948 PM CDT THU JUN 25 2015 .UPDATE... A WARM AND MUGGY EVENING ACROSS THE MIDSOUTH...WITH FAIR WEATHER PREVAILING NEAR THE CENTER OF OF A 592DM 500MB RIDGE. TO THE NORTH... AN MCS WAS RIDING THE PERIPHERY OF THE RIDGE ALONG THE I-70 CORRIDOR. THE 01Z HRRR MODEL APPEARED A LITTLE TOO QUICK IN GENERATING AND ACCELERATING A COLD POOL DIRECTLY SOUTH FROM THE CENTRAL MO MCS. REGARDLESS...OUTFLOW FROM THE CURRENT ACTIVITY ENTERING SOUTH CENTRAL MO WILL LIKELY ENTER NORTHEAST AR AND THE MO BOOTHEEL DURING THE EARLY OVERNIGHT. IT/S UNKNOWN IF THIS OUTFLOW WILL GENERATE NEW CONVECTION AT IT MOVES SOUTH UNDER THE MIDLEVEL RIDGE. MUCH WILL DEPEND ON IF THE COLD POOL CAN ORGANIZE AND ACCELERATE SOUTHWARD AT THE RATE THE HRRR SUGGESTS. FOR THE LATE EVENING UPDATE...HAVE INTRODUCED SLIGHT CHANCE POPS FROM NORTHEAST AR THROUGH NORTHWEST LATE TONIGHT. PWB && .PREV DISCUSSION... /ISSUED 624 PM CDT THU JUN 25 2015/ DISCUSSION... UPDATED FOR 00Z AVIATION DISCUSSION. PREV DISCUSSION... /ISSUED 256 PM CDT THU JUN 25 2015/ DISCUSSION... SKIES REMAIN MOSTLY SUNNY OVER MUCH OF THE FORECAST AREA THIS AFTERNOON WITH TEMPERATURES IN THE LOW TO MID 90S. TEMPERATURES ARE ACTUALLY RUNNING A COUPLE OF DEGREES COOLER THAN YESTERDAY AND HEAT INDEX VALUE ARE ALSO NOT QUITE AS HIGH AS WELL. SOME LOCATIONS ALREADY HAVE HAD HEAT INDEX READINGS ABOVE 105 AND WITH A COUPLE MORE HOURS OF HEATING LEFT SOME OTHER AREAS MAY ALSO REACH ABOVE 105. WILL LET HEAT ADVISORY CONTINUE THROUGH 7 PM CDT. CURRENT RADAR SHOWS VERY LITTLE IF ANY THUNDERSTORM ACTIVITY OVER THE FORECAST AREA SO IT APPEARS THAT MOST AREAS SHOULD REMAIN DRY TONIGHT. CURRENTLY A NEARLY STATIONARY BOUNDARY EXTENDS ACROSS THE CENTRAL PLAINS THROUGH THE OHIO VALLEY AND INTO THE MID-ATLANTIC STATES. THIS FRONT WILL START TO MOVE SOUTH AS A COLD FRONT ON FRIDAY. THUNDERSTORMS ARE EXPECTED TO DEVELOP AHEAD OF THE FRONT AND SOME OF THESE THUNDERSTORMS SHOULD MOVE INTO THE FORECAST AREA. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL AND NORTHWEST TENNESSEE WITH DAMAGING WINDS AND LARGE HAIL AS THE MAIN THREATS. TEMPERATURES WILL BE A LITTLE COOLER WITH THE INCREASE IN CLOUDS AHEAD OF THE FRONT AS HIGHS WILL BE MAINLY IN THE LOWER 90S. HEAT INDEX VALUES WILL NOT BE AS HIGH AS THEY HAVE BEEN THE LAST COUPLE OF DAYS SO A HEAT ADVISORY WILL NOT BE NEEDED. THE COLD FRONT WILL CONTINUE TO MOVE SOUTH AND WILL REACH NORTHERN SECTIONS OF THE FORECAST AREA FRIDAY NIGHT SO THERE WILL BE A BETTER CHANCE OF THUNDERSTORMS. THE SLIGHT RISK OF SEVERE THUNDERSTORMS WILL CONTINUE OVER NORTHERN SECTIONS OF THE FORECAST AREA AS WELL. TEMPERATURES WILL NOT BE AS WARM AS THEY BEEN THE LAST FEW DAYS WITH LOWS SATURDAY MORNING IN THE UPPER 60S TO LOWER 70S. THE COLD FRONT WILL EXIT THE FORECAST AREA SATURDAY MORNING WITH THUNDERSTORMS ENDING OVER NORTH MISSISSIPPI. MUCH COOLER AND DRIER AIR WILL MOVE INTO THE REGION BEHIND THE FRONT WITH HIGHS ON SATURDAY ONLY IN THE LOW TO MID 80S. HIGH PRESSURE WILL BUILD INTO THE REGION SATURDAY NIGHT WITH LOWS SUNDAY MORNING MAINLY IN THE 60S. DRY WEATHER AND BELOW NORMAL TEMPERATURES WILL CONTINUE INTO SUNDAY. BY SUNDAY NIGHT...ANOTHER COLD FRONT WILL START TO MOVE INTO THE CENTRAL PLAINS AND THE MID MISSISSIPPI VALLEY. SOME ISOLATED THUNDERSTORMS MAY BE POSSIBLE OVER EXTREME NORTHWEST SECTIONS OF THE FORECAST AREA. BY MONDAY...THE COLD FRONT WILL CONTINUE TO MOVE SLOWLY SOUTH TOWARD THE FORECAST AREA. AS IT DOES THERE WILL BE A LITTLE BETTER CHANCE OF THUNDERSTORMS. TEMPERATURES WILL CONTINUE TO BE BELOW NORMAL WITH HIGHS IN THE MID 80S. THE COLD FRONT WILL START TO STALL OUT ALONG THE NORTHERN BORDER OF THE FORECAST AREA SO THERE WILL STILL BE SCATTERED THUNDERSTORMS FOR TUESDAY THROUGH NEXT THURSDAY. TEMPERATURES WILL CONTINUE TO BE BELOW NORMAL THROUGH THE PERIOD. ARS && .AVIATION... 00Z TAF CYCLE (26/00Z-26/24Z) VFR THIS PERIOD...WITH THE EXCEPTION FOR TEMPO STORMS AT JBR LATE. OTHER SITES EXPECTING CONVECTIVE ACTIVITY NEARBY WITH IMPACTS ON SITE JUST BEYOND THE PERIOD. LIGHT SOUTHWEST WINDS TONIGHT WILL INCREASE TO 8-10 KTS...WITH OCCASIONAL HIGHER GUSTS. JAB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1154 PM CDT TUE JUN 23 2015 .UPDATE...FOR 06Z AVIATION DISCUSSION. && .AVIATION UPDATE...06Z AVIATION DISCUSSION. SFC FRONT IS EXPECTED TO MOVE S OF MID STATE BY 24/12Z...WHICH WILL USHER IN SOME DRIER AIR TO THE AREA. WITH CONVECTION THIS EVENING NOW HAVING MOVED S OF TERMINALS..SOME MVFR FOG INDUCED VSBYS/CEILINGS POSSIBLE CKV/BNA AROUND 24/06Z-24/15Z PER SUITABLE DEWPOINT DEPRESSIONS AND FROM RAINFALL FROM THIS EVENING`S CONVECTION ALONG WITH LOW LEVEL MOISTURE POOLING POTENTIAL AND SLOWLY CLRING SKIES APPROACHING 24/12Z. WITH DRIER AIR WORKING INTO MID STATE THRU 25/06Z...BELIEVE POTENTIAL FOR ISO SHWRS/TSTMS WILL BE OVERALL LESS THAN THIS AFTERNOON`S COVERAGE AND WILL MENTION ONLY SCT CU...SCT/BKN AC...AND SCT/BKN CI THRU 25/02Z...WITH BKN CI THRU 25/06Z. && .PREV DISCUSSION... /ISSUED 939 PM CDT TUE JUN 23 2015/ UPDATE... 18Z GFS RUN SHOWING UPPER HIGH OVER EASTERN OK WITH THE RIDGE AXIS EXTENDING ESE ACROSS NRN AL. CURVATURE AND SHEAR NOTED UPSTREAM WITH VORT MAX NOW MOVING THROUGH NRN MIDDLE TN. PVA IS CURRENTLY ACROSS SOUTHERN MIDDLE TN AND IS COUPLING WITH DIVERGENCE ALOFT...JUST NORTH OF THE RIDGE AXIS. MEAN 700-500MB FLOW IS RATHER WEAK AND THUS STORMS ARE SLOW MOVERS. PWATS ARE STILL RATHER HIGH AND ISOL AREAS OF FLOODING IS ONGOING. FOR THE UPDATE...WILL INCREASE POPS ACROSS SOUTHWESTERN AREAS AND THE SOUTHERN AND CENTRAL PLATEAU...PER ONGOING CONVECTION. WILL ALSO MAKE A SLIGHT UPWARD TWEAK WITH THE SKY GRIDS. PREV DISCUSSION... /ISSUED 801 PM CDT TUE JUN 23 2015/ UPDATE... WILL ISSUE A QUICK UPDATE AND INCREASE POPS INTO THE CHANCE CATEGORY AREA WIDE BETWEEN NOW AND 03Z. ALSO...WILL INCLUDE FOG ACROSS THE PLATEAU FOR THE AFT MIDNIGHT PERIOD. WILL ALLOW THE SLIGHT CHANCE TO COVER THE PRECIP CHANCES FROM 03Z TO 06Z. THE FRONT IS APPROACHING THE KY/TN BORDER AT THIS TIME. IT IS QUITE WEAK AND THE UPPER RIDGING BUILDING IN FROM THE WEST IS STRENGTHENING. THEREFORE...THIS ACTIVITY SHOULD DIE OUT AS THE NIGHT PROGRESSES. HRRR AND ISC BOTH CONCUR. UPDATE OUT SHORTLY. PREV DISCUSSION... /ISSUED 703 PM CDT TUE JUN 23 2015/ UPDATE...FOR 00Z AVIATION DISCUSSION. AVIATION UPDATE...00Z AVIATION DISCUSSION. SFC FRONT IS EXPECTED TO MOVE S OF MID STATE BY 24/12Z...WHICH WILL USHER IN SOME DRIER AIR TO THE AREA. WITH CONVECTION THIS EVENING NOW HAVING MOVED S OF TERMINALS..SOME MVFR FOG INDUCED VSBYS/CEILINGS POSSIBLE CKV/BNA AROUND 24/06Z-24/15Z PER SUITABLE DEWPOINT DEPRESSIONS AND FROM RAINFALL FROM THIS EVENING`S CONVECTION ALONG WITH LOW LEVEL MOISTURE POOLING POTENTIAL AND SLOWLY CLRING SKIES APPROACHING 24/12Z. WITH DRIER AIR WORKING INTO MID STATE THRU 25/06Z...BELIEVE POTENTIAL FOR ISO SHWRS/TSTMS WILL BE OVERALL LESS THAN THIS AFTERNOON`S COVERAGE AND WILL MENTION ONLY SCT CU...SCT/BKN AC...AND SCT/BKN CI THRU 25/02Z...WITH BKN CI THRU 25/06Z. PREV DISCUSSION.../ISSUED 404 PM CDT TUE JUN 23 2015/ DISCUSSION... TEMPS AND DEWPOINTS SOARING AGAIN THIS AFTERNOON...HEAT INDICES WILL BE BETWEEN 100 AND 104 TODAY. A FEW STORMS HAVE BEEN MOVING ACROSS NORTHERN KENTUCKY THIS AFTERNOON AHEAD OF A COLD FRONT SLOWLY MAKING ITS WAY THROUGH THE OHIO VALLEY. MODELS INDICATE IT WILL MAKE IT FAR ENOUGH SOUTH THIS EVENING TO BRING A FEW ISOLATED SHOWERS AND THUNDERSTORMS TO MIDDLE TENNESSEE...WITH THE BEST CHANCE FOR PRECIP IN THE NORTHEAST COUNTIES. SOME STORMS MAY BECOME STRONG WITH GUSTY WINDS AND HEAVY RAIN. WINDS WILL SHIFT OUT OF THE NORTH OVERNIGHT TONIGHT BRINGING IN SLIGHTLY DRIER AIR...WHICH LOOKS TO KEEP OUR DEWPOINTS LOW ENOUGH ON WEDNESDAY TO ALLOW US TO ONCE AGAIN AVOID A HEAT ADVISORY. HOWEVER, THE HEAT INDICES ARE STILL EXPECTED TO BE IN THE 100 TO 105 RANGE FOR OUR SOUTHERN COUNTIES...SO WE`LL CONTINUE TO KEEP AN EYE ON DEWPOINTS AND TEMPS THROUGHOUT THE DAY IN THAT AREA. WITH WEDNESDAY`S DRIER AIR COMES LOWER POPS WITH ONLY AN AFTERNOON THUNDERSTORM OR TWO EXPECTED. DEWPOINTS RECOVER ON THURSDAY AS A SURFACE HIGH PASSES NORTHEAST OF THE TENNESSEE VALLEY STIRRING UP A LIGHT SOUTHERLY FLOW AND AN INCREASE IN MOISTURE OVER MIDDLE TENNESSEE. CONSEQUENTLY EXPECT A FEW MORE SHOWERS AND THUNDERSTORMS THURSDAY AFTERNOON AND EVENING ALONG WITH HEAT INDICES AROUND ADVISORY CRITERIA...105 TO 108. WILL HOLD OFF ON ISSUING AN ADVISORY AT THIS TIME UNTIL CONFIDENCE IS HIGHER. PRECIP CHANCES INCREASE AS WE HEAD INTO FRIDAY. AN UPPER TROUGH WILL DEEPEN OVER THE EASTERN U.S. AND SWING A COLD FRONT THROUGH THE TENNESSEE VALLEY EARLY SATURDAY MORNING. THIS WILL ALLOW FOR A GOOD FOCUSING MECHANISM FOR THUNDERSTORM DEVELOPMENT. FRIDAY AFTERNOON INSTABILITY IS HIGH ENOUGH FOR THUNDERSTORM DEVELOPMENT...HOWEVER THE FRONT WILL BE LOCATED TO THE NORTH OF THE CWA DURING THIS TIME...SO ANY STORMS WILL LIKELY SPARK DUE TO AFTERNOON HEATING. ALONG WITH THE LACK OF A FOCUSING MECHANISM...ORGANIZATION MAY BE LIMITED BY BULK SHEAR VALUES LESS THAN 30KTS...HOWEVER SOME SEVERE STORMS WILL STILL BE POSSIBLE WITH THE AMOUNT OF INSTABILITY IN PLACE. PWATS ARE IMPRESSIVE DURING THIS TIME FRAME WITH VALUES OF 1.9 TO 2.00 INCHES STILL INDICATED ON BOTH THE NAM AND THE GFS...SO EXPECTING STRONG...POSSIBLY SEVERE STORMS WITH HEAVY RAINFALL FRIDAY AFTERNOON AND EVENING. AS THE FRONT APPROACHES ON SATURDAY MORNING BULK SHEAR VALUES INCREASE TO AROUND 40KTS. COULD SEE A SPIKE IN THUNDERSTORM ACTIVITY EARLY SATURDAY MORNING ALONG THE FRONTAL BOUNDARY THEN COOLER TEMPS DURING THE AFTERNOON WITH MOSTLY CLOUDY SKIES BEHIND THE FRONT. CONDITIONS DRY OUT GOING INTO SUNDAY AS THE PREVIOUS SYSTEM CONTINUES OFF TO THE EAST AND LEAVES THE MID STATE WITH MUCH MORE PLEASANT DEWPOINTS AND HIGH TEMPERATURES. SUNDAY LOOKS TO BE A GREAT DAY TO GET OUTSIDE AND ENJOY TEMPERATURES AROUND 80 WITH DEWPOINTS IN THE LOW 60S. TEMPERATURES GRADUALLY WARM DURING THE FIRST HALF OF THE WORK WEEK NEXT WEEK AS A WEAK SURFACE HIGH MOVES ACROSS THE TENNESSEE VALLEY. A CHANCE OF THUNDERSTORMS CREEPS INTO THE FORECAST BY TUESDAY. PREV DISCUSSION... /ISSUED 108 PM CDT TUE JUN 23 2015/ AVIATION UPDATE... SURFACE FRONT JUST NORTH OF THE OHIO RIVER WILL MOVE SOUTHWARD AS WE GO THROUGH THE AFTERNOON AND INTO TONIGHT. AM LOOKING FOR A LINE OF CONVECTION TO FIRE OFF ALONG THE OHIO RIVER 20Z-21Z TIME FRAME AND SINK SOUTHWARD WITH THE LEADING EDGE ALONG THE TENNESSEE/KENTUCKY BORDER AROUND 00Z AND CONTINUE SOUTHWARD INTO MIDDLE TENNESSEE DURING THE EVENING. FOR NOW WILL RUN VICINITY THUNDERSTORMS AT TERMINALS BUT WILL UPDATE ONCE LINE DEVELOPS AND TRY AND TIME IT A LITTLE BETTER. ALSO...LOOKING FOR SOME LATE NIGHT FOG. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 74 92 73 96 / 30 20 10 20 CLARKSVILLE 72 89 72 94 / 30 20 10 10 CROSSVILLE 70 86 68 90 / 40 20 10 20 COLUMBIA 74 93 73 97 / 30 20 10 20 LAWRENCEBURG 74 93 73 95 / 50 20 10 20 WAVERLY 73 91 73 95 / 30 20 10 20 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1124 PM CDT TUE JUN 23 2015 .UPDATE... UPDATED TO ADD 06Z AVIATION DISCUSSION. && .PREV DISCUSSION... /ISSUED 1022 PM CDT TUE JUN 23 2015/ UPDATE...EVENING UPDATE IT NOW LOOKS MORE LIKELY THAT THUNDERSTORMS WILL CONTINUE OVERNIGHT PUSHING SOUTH ACROSS MOST IF NOT ALL OF THE MIDSOUTH. ADJUSTED POPS ACCORDINGLY. STORMS WILL MAINLY IMPACT WEST TENNESSEE AND NORTH MISSISSIPPI...BUT CANNOT BE RULED OUT ANYWHERE. FREQUENT LIGHTENING AND VERY HEAVY RAINFALL CAN BE EXPECTED. LOCALIZED FLOODING IS POSSIBLE. WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED AT THIS TIME. 30 PREV DISCUSSION... /ISSUED 719 PM CDT TUE JUN 23 2015/ UPDATE...EVENING UPDATE. DISCUSSION... INCREASED POPS ACROSS WEST TENNESSEE...THE MISSOURI BOOTHEEL AND NORTHEAST ARKANSAS. DON`T THINK THERE IS ANY REAL SEVERE THREAT BUT LOCALLY HEAVY RAIN AND FREQUENT LIGHTNING IS LIKELY. STORMS SHOULD DIMINISH IN BOTH INTENSITY AND COVERAGE AFTER SUNSET. PREV DISCUSSION... /ISSUED 623 PM CDT TUE JUN 23 2015/ CURRENTLY...STRONG UPPER RIDGE EXTENDS FROM THE SOUTHERN PLAINS INTO THE MIDSOUTH. MEANWHILE A WEAK COLD FRONT HAS PUSHED INTO SOUTHERN MISSOURI AND WESTERN KY...JUST NORTH OF THE MIDSOUTH. VERY WARM AIR HAS PUSHED INTO THE MIDSOUTH WITH TEMPS IN THE MID 90S ACROSS MUCH OF THE AREA. SURFACE DEWPOINTS ARE POOLING ACROSS THE REGION...SOUTH OF THE COLD FRONT...WITH READINGS IN THE MID TO SOMETIMES UPPER 70S. THIS IS CREATING HEAT INDEX VALUES ABOVE 105 ACROSS MUCH OF THE MIDSOUTH. HAVE EXPANDED THE HEAT ADVISORY TO COVER MOST OF THE MIDSOUTH THIS AFTERNOON INTO WEDNESDAY. THE HRRR HAS BEEN TRYING TO DEVELOP CONVECTION ALONG THE WEAK COLD FRONT TO THE NORTH FOR THE LAST FEW HOURS BUT IT HAS NOT HAPPENED YET. GIVEN THE WEAK CAP AND SBCAPES AROUND 5000 J/KG THERE IS STILL THE POSSIBILITY OF ISOLATED STORMS DEVELOPING OVER THE NEXT FEW HOURS. TONIGHT...ANY CONVECTION WILL DISSIPATE BY 02Z OR SO WITH MOSTLY CLEAR SKIES AND WARM TEMPERATURES OVERNIGHT. LOWS IN THE 70S. WEDNESDAY...ANOTHER VERY HOT AND HUMID DAY WITH THE UPPER RIDGE CENTERED OVER THE AREA. EXPECT HIGHS IN THE MID 90S AND DEWPOINTS IN THE MID 70S. THE HEAT ADVISORY HAS BEEN EXTENDED THROUGH 7 PM THURSDAY FOR MOST OF THE MIDSOUTH FOR HEAT INDICES EXCEEDING 105 DEGREES WEDNESDAY AFTERNOON. AN ISOLATED AFTERNOON STORM COULD OCCUR ANYWHERE BUT THE BEST CHANCE WILL PROBABLY BE ACROSS NORTH MISSISSIPPI. THURSDAY...THE UPPER RIDGE WEAKENS A BIT ON THURSDAY BUT STILL HOT AND HUMID. HEAT ADVISORIES MAY NEED TO BE EXTENDED. STILL VERY WARM AIRMASS ACROSS THE REGION WITH 925MB TEMPS OF 28C ACROSS MUCH OF THE AREA. MODELS ARE POINTING TOWARD INCREASING MOISTURE MOVING UP FROM THE GULF WITH BETTER CHANCES OF AFTERNOON SHOWERS AND THUNDERSTORMS ACROSS NORTH MISSISSIPPI. FRIDAY AND SATURDAY...MAJOR PATTERN SHIFT AS THE UPPER RIDGE BREAKS DOWN AND A DEEP UPPER TROF DEVELOPS OVER THE EASTERN U.S. A COLD FRONT WILL PUSH THROUGH THE AREA FRIDAY INTO SATURDAY MORNING WITH NUMEROUS SHOWERS AND THUNDERSTORMS. A FEW STRONG TO SEVERE STORMS ARE POSSIBLE DURING THIS PERIOD. MUCH COOLER AND DRIER WEATHER WILL SETTLE OVER THE REGION LATER SATURDAY INTO EARLY NEXT WEEK AS THE REGION REMAINS UNDER THE INFLUENCE OF THE UNSEASONABLE DEEP UPPER TROF. SJM && .AVIATION... 06Z TAF CYCLE SHOWERS AND THUNDERSTORMS WILL AFFECT TUP THROUGH 24/08Z. OTHERWISE...SHORT TERM TRENDS SUGGEST A WEAK SURFACE BOUNDARY AND LEFTOVER OUTFLOW BOUNDARIES FROM TONIGHT/S CONVECTIVE ACTIVITY MAY INTERACT WITH AN UNSTABLE ATMOSPHERE TO TRIGGER REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS TAF SITES...PREDOMINANTLY AT MKL...TUP...AND MEM MAINLY AFTER 24/17Z. TEMPORARY IFR CONDITIONS POSSIBLE WITHIN THUNDERSTORMS. OTHERWISE...VFR CONDITIONS EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD. LIGHT W/NW WINDS WILL VEER N ON WEDNESDAY. CJC && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY FROM NOON TO 7 PM CDT WEDNESDAY FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...HEAT ADVISORY FROM NOON TO 7 PM CDT WEDNESDAY FOR DUNKLIN- PEMISCOT. MS...HEAT ADVISORY FROM NOON TO 7 PM CDT WEDNESDAY FOR ALCORN-BENTON MS-CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN- TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA. TN...HEAT ADVISORY FROM NOON TO 7 PM CDT WEDNESDAY FOR CHESTER- CROCKETT-DYER-FAYETTE-HARDEMAN-HARDIN-HAYWOOD-LAKE- LAUDERDALE-MADISON-MCNAIRY-OBION-SHELBY-TIPTON. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
110 AM CDT WED JUN 24 2015 .UPDATE... PLEASE SEE THE 06Z AVIATION DISCUSSION BELOW. && .AVIATION... LITTLE CHANGES HAVE BEEN MADE TO THE ONGOING AVIATION FORECASTS. THE LATEST RADAR DATA DOES SHOW SOME CONVECTION ACROSS THE WESTERN HILL COUNTRY...SOUTHERN EDWARDS PLATEAU AND RIO GRANDE PLAINS EARLY THIS MORNING. THIS ACTIVITY IS EXPECTED TO REMAIN TOO ISOLATED TO MENTION IN THE LATEST FORECAST. OTHERWISE...LOW CLOUDS WILL CONTINUE TO DEVELOP OVERNIGHT...LEADING TO MVFR AND IFR CONDITIONS THROUGH ROUGHLY 16Z. CLOUDS WILL LIFT WITH VFR EXPECTED FOR TOMORROW AFTERNOON. && .PREV DISCUSSION... /ISSUED 1124 PM CDT TUE JUN 23 2015/ UPDATE... HAVE MADE A QUICK PRE-MORNING PACKAGE UPDATE TO THE ONGOING FORECAST BASED ON CURRENT RADAR TRENDS AND RECENT RUNS OF THE HRRR. THE HRRR SUGGESTS THAT THE VERY ISOLATED SHOWERS THAT ARE CURRENTLY ONGOING FROM COMSTOCK...EAST TO HONDO...AND NORTH TO LLANO WILL CONTINUE THROUGH THE EARLY MORNING HOURS. HAVE ADDED SLIGHT CHANCE POPS TO THE WESTERN HILL COUNTRY...EDWARDS PLATEAU...AND RIO GRANDE PLAINS. HAVE ALSO RETRENDED HOURLY GRIDS. PREV DISCUSSION... /ISSUED 543 PM CDT TUE JUN 23 2015/ UPDATE... /SLIGHT ADJUSTMENT TO EVENING POPS/ SOME POPS WERE ADDED DEEPER INTO THE HILL COUNTRY TO ACCOUNT FOR SOME SEA-BREEZE ENHANCED STREAMER CONVECTION...AND WERE RAISED TO 30 PERCENT WHERE SOME CLUSTERS HAVE FORMED OVER THE RIO GRANDE PLAINS. RAPID REFRESH MODELS STILL SHOW A WEAKENING TREND WITH THE LOSS OF DAYTIME HEATING...SO THE AFTERNOON FORECAST PACKAGE REMAINS ON TRACK FOR THE REST OF TONIGHT. PREV DISCUSSION... /ISSUED 233 PM CDT TUE JUN 23 2015/ SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)... STARTING TO SEE MORE EFFECTS FROM THE UPPER RIDGE TODAY AND THE OVERALL COVERAGE OF SHOWERS AND THUNDERSTORMS IS LOWER. WE DO HAVE A FEW STORMS ACROSS THE SOUTHERN COUNTIES...BUT THIS IS NOT ACCOUNTING FOR MUCH RAINFALL. SHOULD SEE THIS ACTIVITY LINGER FOR THE NEXT SEVERAL HOURS BEFORE DISSIPATING WITH THE LOSS OF DAYTIME HEATING. WILL CARRY 20 POPS AFTER 00Z FOR VAL VERDE COUNTY AS HIGH-RES MODELS ARE HINTING AT SOME ACTIVITY REMAINING CLOSER TO THE DEPARTING UPPER LOW. TOMORROW SHOULD BE SIMILAR TO TODAY WITH 20-40 POPS ACROSS THE SOUTHERN AND SOUTHEASTERN CWA FOR ANY ACTIVITY ASSOCIATED WITH THE AFTERNOON SEA BREEZE. HIGHS TOMORROW WILL BE NEAR 90 DEGREES AND WITH AFTERNOON DEWPOINTS REMAINING IN THE LOW 70S...HEAT INDICES WILL REACH THE UPPER 90S. LONG TERM (THURSDAY THROUGH TUESDAY)... THURSDAY SHOULD CONTINUE TO SAME FORECAST AS THE PREVIOUS COUPLE OF DAYS. WE COULD SEE THE BEST DAY FOR SEA BREEZE ACTIVITY AS LOW-LEVEL WINDS ARE A BIT LESS AND SHOULD PROMOTE A BIT MORE COVERAGE OF SHOWERS AND STORMS. THE ATMOSPHERE SHOULD TEMPORARILY DRY OUT A BIT FRIDAY AND WE SHOULD NOT SEE MUCH ACTIVITY. THE FOCUS OF THE REMAINING FORECASTS SHIFTS TO A POSSIBLE COLD FRONT AFFECTING THE AREA AND INCREASING RAIN CHANCES SATURDAY NIGHT THROUGH TUESDAY. A STRONG RIDGE WILL AMPLIFY ACROSS THE WESTERN CONUS THIS WEEKEND WITH A DEEP TROUGH ACROSS THE EASTERN CONUS. THIS WILL ALLOW A LATE-SEASON COLD FRONT TO DIVE SOUTH AND BEGIN TO ENTER OUR NORTHERN CWA SATURDAY NIGHT. POPS FOR NOW WILL BE IN THE 20 TO 50 PERCENT RANGE BUT COULD BE RAISED AS CONFIDENCE INCREASES CLOSER TO THIS WEEKEND. PRECIPITABLE WATER VALUES WILL BE NEAR 2 INCHES AND THIS COMBINED WITH A FRONTAL BOUNDARY AND EXPECTED SLOW STORM MOTIONS COULD LEAD TO LOCALLY HEAVY RAINFALL. THIS WILL BE SOMETHING THAT NEEDS TO BE WATCHED CLOSELY AS WE NEAR THE WEEKEND. THE FRONT IS EXPECTED TO LIFT NORTH ON MONDAY AND ADDITIONAL RAIN CHANCES WILL CONTINUE THROUGH TUESDAY WITH PLENTY OF MOISTURE LEFT OVER. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 90 72 89 73 91 / 20 10 20 10 - AUSTIN BERGSTROM INTL AIRPORT 89 71 88 72 90 / 20 10 20 10 - NEW BRAUNFELS MUNI AIRPORT 89 72 89 73 91 / 20 10 20 10 - BURNET MUNI AIRPORT 88 71 89 72 91 / 10 10 10 10 - DEL RIO INTL AIRPORT 89 73 91 73 93 / 20 10 10 10 - GEORGETOWN MUNI AIRPORT 89 72 89 73 91 / 10 10 10 10 - HONDO MUNI AIRPORT 88 72 89 72 90 / 20 10 20 10 - SAN MARCOS MUNI AIRPORT 88 72 88 73 90 / 20 10 20 10 - LA GRANGE - FAYETTE REGIONAL 90 73 89 74 90 / 30 10 40 10 10 SAN ANTONIO INTL AIRPORT 88 73 89 74 90 / 20 10 20 10 - STINSON MUNI AIRPORT 89 73 89 73 91 / 20 10 20 10 - && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...24 SYNOPTIC/GRIDS...TREADWAY
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
352 PM CDT WED JUN 24 2015 .SHORT TERM... TONIGHT... FORECAST CONFIDENCE MEDIUM. CONVECTION ASSOCIATED WITH THE LOW LEVEL JET /LLJ/... SHORTWAVE ENERGY AND UPPER LEVEL DIVERGENCE OVER CENTRAL IOWA WILL CONTINUE TO MOVE ESE THROUGH NORTHERN IL. ONLY LIGHT SHOWERS... IF ANYTHING... ARE EXPECTED TO REACH SOUTHERN WI FROM LATE AFTERNOON THROUGH EARLY EVENING. THE LLJ IS EXPECTED TO INTENSIFY OVER SOUTH CENTRAL IOWA THIS EVENING AS IT VEERS EAST. THE NOSE OF THE LLJ IS NOW EXPECTED TO REMAIN OVER EAST CENTRAL IOWA OR SOUTH... ALONG WITH THE 850MB WARM FRONT. THIS IS FARTHER SOUTH THAN MANY OF THE PREVIOUS MODEL RUNS. THUNDERSTORMS ARE ANTICIPATED TO FIRE UP ALONG THE SURFACE WARM FRONT OVER CENTRAL IOWA WITH THE INCREASING LLJ LATE THIS EVENING PER THE HRRR AND THEN SLIDE EAST THROUGH CENTRAL IL. KEPT CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS SOUTHERN WI DUE TO THE VICINITY OF THE NOSE OF THE LLJ... UPPER DIVERGENCE WITH THE RIGHT ENTRANCE REGION OF THE UPPER JET... AND WEAK VORTICITY ADVECTION. ELEVATED INSTABILITY WILL REMAIN WEAK WITH LESS THAN 500 J/KG CAPE. NOT EXPECTING HEAVY RAIN TRAINING OVER AN AREA FOR A LONG PERIOD OF TIME. NOT EXPECTING SEVERE WEATHER ALTHOUGH SPC HAS NOT TRIMMED SOUTHERN WI OUT OF THE SLIGHT RISK YET THIS AFTERNOON. .THURSDAY... FORECAST CONFIDENCE MEDIUM. LIGHT SURFACE WINDS AND LINGERING LOW LEVEL MOISTURE SHOULD LEAD TO LOW CLOUDS ACROSS SOUTHERN WI EARLY THURSDAY MORNING. THESE SHOULD SLOWLY SCOUR OUT THROUGH THE DAY. LIGHT RAIN SHOWERS MAY LINGER WITH THIS MOISTURE THROUGH THE MORNING HOURS BUT CONFIDENCE IS LOW... SO ONLY HAVE SLIGHT CHANCE POPS IN FORECAST. AFTERNOON SHOULD BE DRY WITH INCREASING SUNSHINE AND HIGHS BACK UP AROUND 80 EXCEPT NEAR THE LAKE. .LONG TERM... .FRIDAY AND SATURDAY... NW FLOW ALOFT WILL TURN MORE CYCLONIC AS A SHARP UPPER LEVEL TROF DIVES SOUTH ACROSS THE REGION ON FRIDAY AND SATURDAY. HOWEVER...THE FLOW OVER WISCONSIN DURING THIS PERIOD WILL BE WEAK...AND THERE WILL BE LITTLE FORCING FOR ASCENT IN THE UPPER LEVELS. IN THE MID- LEVELS...WE WILL BE ON THE COOL AND DRY SIDE OF A FRONT EXTENDING WEST FROM THE LOW THAT WILL PASS ON THURSDAY. A SECOND LOW WILL APPROACH THE STATE FROM THE SOUTHWEST ON FRIDAY...BUT SHOULD STAY TO THE SOUTH OF THE STATE THANKS TO THE FRONT IN PLACE. GFS AND EURO DO BRING SOME LIGHT PRECIP INTO THE AREA ON FRIDAY AFTERNOON...BUT CHOSE TO REMAIN DRY AT THIS POINT GIVEN THE MEAGER ASCENT AND MOISTURE. BY FRIDAY EVENING...THE UPPER LEVEL TROF AXIS WILL HAVE PASSED TO THE EAST OF THE STATE...PLACING WISCONSIN UNDER NORTHERLY FLOW ALOFT. THE MID AND LOW LEVELS WILL DRY OUT...MAKING FOR A VERY NICE DAY ON SATURDAY. .SUNDAY THROUGH WEDNESDAY... WISCONSIN WILL BE FIRMLY ENTRENCHED IN NNW FLOW ALOFT AS A DEEP UPPER LEVEL TROF STALLS OVER THE EASTERN CONUS AND A ROBUST RIDGE/CLOSED HIGH BUILDS INTO THE WESTERN CONUS. THIS PATTERN WILL PERSIST THROUGH THE PERIOD AS A FEW SHORTWAVE TROFS PASS ACROSS THE STATE REINFORCING THE TROF OVER THE EAST. THOSE SHORTWAVES WILL PROVIDE THE LIFT FOR RAIN CHANCES EACH DAY IN THIS PERIOD. THE NW FLOW SHOULD KEEP TEMPS SLIGHTLY BELOW NORMAL THROUGH THIS PERIOD. && .AVIATION/00Z TAFS/... VFR CONDITIONS ARE EXPECTED THROUGH LATE EVENING. A COMPLEX OF STORMS IS THEN EXPECTED TO TRACK ACROSS CENTRAL ILLINOIS OVERNIGHT. SOUTHERN WI SHOULD GET CLIPPED BY SHOWERS AND A FEW THUNDERSTORMS ON THE NORTHERN SIDE OF THE MAIN AREA OF CONVECTION. MVFR CONDITIONS CAN BE EXPECTED WITHIN ANY THUNDERSTORMS. IFR CONDITIONS WITH CIGS/VSBYS ARE POSSIBLE LATER TONIGHT AS THE CONVECTION MOVES OFF WHILE THE ATMOSPHERE REMAINS VERY MOIST WITHIN A VERY WEAK LOW LEVEL FLOW. VFR EXPECTED BY THU AFTERNOON. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TONIGHT/THURSDAY AND AVIATION/MARINE...MRC THURSDAY NIGHT THROUGH WEDNESDAY...BSH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
217 PM CDT WED JUN 24 2015 .SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT) ISSUED AT 217 PM CDT WED JUN 24 2015 WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS THIS AFTERNOON SHOWS WEST/NORTHWEST FLOW ACROSS THE DAKOTAS INTO THE GREAT LAKES REGION. WITHIN THIS FLOW A COUPLE OF WEAK EMBEDDED SHORT WAVE TROUGHS WERE ACROSS NORTHERN MN AND ACROSS EASTERN NEB/WESTERN IA. STRONG TO SEVERE THUNDERSTORMS WERE TIED TO SHORTWAVE COMING ACROSS EASTERN NEB/WESTERN IA WHILE THE CONVECTION ACROSS NORTHERN MN/UPPER MI WAS TIED MORE TO CONVERGENCE OF LAKE BREEZE FRONT. OUR AREA WAS IN BETWEEN THESE TWO SYSTEM...HIGH AND DRY FOR NOW. UNDER PARTLY CLOUDY SKIES...TEMPERATURES RANGED FROM THE MIDDLE 70S TO THE LOWER 80S. FOR TONIGHT...WILL SEE THAT MID-LEVEL SHORTWAVE AND MCV ACROSS IA PASS SOUTH OF THE AREA EARLY THIS EVENING. MODELS THEN SHOW RETURN 850MB FLOW BEHIND THIS SYSTEM LATER THIS EVENING INTO THE OVERNIGHT HOURS. THIS PUSHES A WARM FRONT THAT WAS OVER NORTHERN KS INTO NORTHERN MO...NORTHWARD NEAR I-80. 850MB MOISTURE TRANSPORT LOOKS TO REGENERATE A BAND OF ELEVATED SHOWERS AND THUNDERSTORMS NORTH OF THE WARM FRONT...POSSIBLE GRAZING OUR NORTHEAST IA COUNTIES. LATEST WRF RUNS KEEP CONVECTION JUST TO OUR SOUTH WHILE COARSER DETERMINISTIC NAM/GFS/ECMWF MODELS SUGGESTING CONVECTION REACHING INTO NORTHEAST IA AND SOUTHWEST WI. WILL KEEP LIKELY POPS CONFINED TO FAR SOUTHERN FAYETTE/CLAYTON COUNTIES IN NORTHEAST IA AND FAR SOUTHER GRANT COUNTY IN WI...TAPERING OFF RAPIDLY TO SLIGHT CHANCE POPS ALONG/SOUTH OF I-90. HIGHER CAPE AXIS STAYS SOUTH OF THE AREA THROUGH TONIGHT...SO NOT ANTICIPATING ANY SEVERE WEATHER IN OUR FORECAST AREA...BUT WILL CONTINUE TO MAINTAIN A WATCHFUL EYE IN CASE THE WARM FRONT/CAPE POOL SURGES FARTHER NORTHWARD THAN ANTICIPATED. ALSO...WILL HAVE TO KEEP AN EYE ON THE SHOWERS/STORMS ACROSS NORTHERN WI OVERNIGHT AS THAT WEAK MID-LEVEL TROUGH SWINGS THROUGH. NOT MUCH WORKING FOR IT OTHER THAN STEEPER MID-LEVEL LAPSE RATES...BUT NO SURFACE CONVERGENCE OR TRIGGER. IN FACT...MOST OF THE WRF MODELS SHOW A WEAKENING TREND AFTER SUNSET WITH LOSS OF HEATING. THURSDAY LOOKS FAIRLY QUIET AND COOLER THAN NORMAL AS NORTHWEST FLOW ALOFT DOMINATES THE REGION. WITH SURFACE HIGH PRESSURE OVER LAKE SUPERIOR PUMPING DRIER NORTHEAST FLOW INTO THE AREA...THINKING MODELS ARE OVERDONE ON CONVECTION. LOOKS LIKE A LOT OF CUMULUS...BUT ANY SHOWER/THUNDER SHOULD REMAIN CONFINED TO FAR NORTHERN WI/U.P. IN STEEPER LAPSE RATES AND CLOSER TO ANY LAKE BREEZE CONVERGENCE ZONES. OTHERWISE...LOOK FOR HIGHS GENERALLY IN THE 75-80 DEGREE RANGE. FOR THURSDAY NIGHT...NORTHWEST FLOW DROPS ANOTHER MID-LEVEL TROUGH/PV-ADVECTION ACROSS MN INTO IA WITH A SURFACE TROUGH IN PLACE. THIS LOOKS TO PRODUCE A FEW SHOWERS/ISOLATED STORMS WEST OF THE MISSISSIPPI RIVER. LOOK FOR OVERNIGHT TEMPERATURES DROPPING INTO THE MID 50S TO THE LOWER 60S. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 217 PM CDT WED JUN 24 2015 WILL STILL SEE A SLIGHT CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS MAINLY WEST OF THE MISSISSIPPI RIVER FRIDAY AS THE MID-LEVEL TROUGH CONTINUES TO ROTATE SOUTHEAST ACROSS THAT AREA. OTHERWISE...PLAN ON A PARTLY SUNNY DAY DOMINATED WITH DECENT CUMULUS FIELD WITH HIGHS ONLY TOPPING OFF IN THE LOWER/MIDDLE 70S. FRIDAY NIGHT THROUGH SATURDAY LOOK DRY AS A WEAK RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION. LOOK FOR HIGHS IN THE 75-80 DEGREE RANGE. THE REST OF THE WEEKEND INTO MID-NEXT WEEK IS DOMINATED WITH MUDDLED NORTHWEST FLOW ALOFT WITH EMBEDDED SHORTWAVE TROUGH ENERGY. AS A RESULT...PLAN ON PERIODIC ON/OFF SHOWER AND THUNDERSTORM CHANCES WITH TEMPERATURES REMAINING BELOW NORMAL. LOOK FOR HIGHS IN THE MIDDLE/UPPER 70S WITH LOWS IN THE MIDDLE 50S TO THE LOWER 60S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1215 PM CDT WED JUN 24 2015 WARM FRONT OF INTEREST FOR CONVECTION LATE THIS AFTERNOON AND TONIGHT REMAINS IN NORTHERN MO EARLY THIS AFTERNOON. CONVECTION EARLY THIS AFTERNOON CONFINED TO FAR EASTERN NEB AND SOUTHERN 2/3 OF IA...MOVING STEADILY EAST. THIS CONVECTION WILL KEEP THE FRONT FROM MOVING NORTH THRU THE AFTERNOON...WITH LITTLE MORE THAN SCT DIURNAL CUMULUS AND GOOD VFR EXPECTED AT THE TAF SITES THRU EARLY THIS EVENING. STILL A SHRA/TSRA CHANCE LATER THIS EVENING AND OVERNIGHT AS A SURGE OF MOISTURE PUSHES NORTHEAST OVER THE WARM FRONT. APPEARS THE BULK OF THIS WILL STAY SOUTH OF THE MN/IA BORDER AND LEFT TAFS FREE OF A SHRA/TSRA MENTION TONIGHT BUT DID INCLUDE SOME 3500-4500 FT CIGS OVERNIGHT. SFC LOW PASSES ACROSS IA TONIGHT WITH DRIER NORTHEAST TO NORTH FLOW AND GOOD VFR SPREADING ACROSS THE AREA THU. && .HYDROLOGY... ISSUED AT 217 PM CDT WED JUN 24 2015 RIVERS ARE RECEDING. SOME MINOR FLOODING REMAINS ALONG THE CEDAR RIVER AT CHARLES CITY...BUT THE RIVER IS FORECAST TO FALL BELOW STAGE THIS AFTERNOON. REFER TO THE LATEST FLOOD STATEMENTS FOR THE LATEST STAGES AND FORECAST. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM....DAS AVIATION.....RRS HYDROLOGY....DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
346 AM CDT WED JUN 24 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 346 AM CDT WED JUN 24 2015 LATEST WATER VAPOR SATELLITE IMAGERY INDICATING WEST TO EAST ZONAL FLOW ACROSS THE NORTHERN TIER STATES WITH SEVERAL PIECES OF ENERGY EMBEDDED IN THE FLOW. LATEST 08Z SURFACE ANALYSIS SHOWS SURFACE FRONT EXTENDING FROM WESTERN KANSAS INTO WESTERN KENTUCKY. CURRENT MOSAIC RADAR INDICATES SHOWERS AND THUNDERSTORMS OVER EASTERN NEBRASKA...CENTRAL AND WESTERN IOWA. THIS IS IN RESPONSE TO 850-700MB MOISTURE TRANSPORT/CONVERGENCE IN ASSOCIATION WITH A SUBTLE SHORTWAVE TROUGH OVER CENTRAL NEBRASKA. MAIN FORECAST CONCERNS TODAY INTO TONIGHT CONTINUE TO BE PLACEMENT OF SURFACE FRONT AND HOW FAR NORTH SURFACE FRONT MOVES TODAY. FIRST WEAK SHORTWAVE OVER EASTERN NEBRASKA/WESTERN IOWA AND ASSOCIATED CONVECTION IS EXPECTED TO REMAIN TO THE SOUTH OF THE FORECAST AREA THIS MORNING. A SECOND PIECE OF ENERGY OVER WESTERN SOUTH DAKOTA WILL QUICKLY PUSH INTO CENTRAL IOWA AROUND 18Z TODAY AND SPREAD SCATTERED CONVECTION INTO THE FAR SOUTHERN PART OF THE FORECAST AREA. THEN FOCUS TURNS TO SURFACE FRONT...AS THE LATEST 24.00Z GFS/NAM CONTINUE TO LIFT SURFACE FRONT INTO CENTRAL IOWA...AND THE 24.00Z ECMWF SUGGEST FRONT WILL REMAIN OVER IOWA/MISSOURI BORDER THIS AFTERNOON INTO TONIGHT. HIGH RESOLUTION MODELS...ARW/NMM/NAM NEST...SHOW SETTLE DIFFERENCES ON PLACEMENT OF SURFACE FRONT OVER SOUTHERN IOWA. WITH THE 24.00Z GFS/NAM FARTHER NORTH SOLUTION...CONVECTION DEVELOPS OVER THE SOUTHERN HALF OF THE FORECAST AREA. WITH THE FARTHER SOLUTION PLACEMENT OF THE FRONT...THE 24.00Z ECMWF AND HIGH RESOLUTION MODELS FOCUS CONVECTION OVER THE FAR SOUTHERN FORECAST AREA OR JUST TO THE SOUTH OF THE FORECAST AREA THIS AFTERNOON INTO TONIGHT. WITH THIS...CONFIDENCE TODAY INTO TONIGHT REMAINS ON THE LOW SIDE. GIVEN THE HIGH RESOLUTION MODELS ARE SOMEWHAT IN AGREEMENT WITH THE 24.00Z ECMWF...WILL CONTINUE TO FOCUS HIGHER PRECIPITATION CHANCES OVER THE SOUTHERN PART OF THE FORECAST AREA TODAY INTO TONIGHT. MODELS CONTINUE TO SHOW DECENT SHEAR OF 30 TO 40 KNOTS OF 0-3KM SHEAR/AROUND 50 KNOTS OF 0-6KM SHEAR ACROSS MUCH OF THE FORECAST AREA...AND 0-6KM MOST UNSTABLE CAPE OF 1000-2000 J/KG ACROSS THE EXTREME SOUTHERN PORTION OF THE FORECAST AREA. CANNOT RULE THE POSSIBILITY OF AN ISOLATED LARGE HAIL OR DAMAGING WIND WITH ANY THUNDERSTORMS CONFINED TO THE FAR SOUTHERN PART OF THE FORECAST AREA. THE BIGGEST CONCERN IS THE POSSIBILITY OF ENTRAINMENT OF CONVECTION ACROSS THE FAR SOUTHERN PART OF THE FORECAST AREA LATE THIS EVENING INTO TONIGHT...WHICH WOULD POSE A FLASH FLOODING THREAT. THE MAJORITY OF THE HIGH RESOLUTION MODELS SUGGEST ENTRAINMENT OF THE CONVECTION TO BE JUST SOUTH OF THE FORECAST AREA. IF CONVECTION DEVELOPS FARTHER NORTH...THEN THE FAR SOUTHERN FORECAST AREA...COULD SEE THE POTENTIAL FOR LOCALLY HEAVY RAINFALL. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 346 AM CDT WED JUN 24 2015 MAIN SHORTWAVE TROUGH PUSHES EAST OF THE FORECAST AREA AND WEAK SUBSIDENCE BEHIND SHORTWAVE TROUGH WILL ALLOW FOR PRECIPITATION TO MOVE EAST OF THE FORECAST AREA THURSDAY INTO THURSDAY NIGHT. THE 24.00Z GFS/NAM/ECMWF ARE IN AGREEMENT IN DIGGING UPPER LEVEL TROUGH INTO THE OHIO RIVER VALLEY FRIDAY. WITH DEEPER MOISTURE/CONVERGENCE WEST/SOUTH OF THE FORECAST AREA...AND A DRY EASTERLY FLOW ALOFT OVER FORECAST AREA. HAVE REDUCED PRECIPITATION CHANCES OVER THE EASTERN FORECAST AREA AND KEPT PRECIPITATION CHANCES CONFINED OVER THE WESTERN FORECAST AREA. THE LATEST 24.00Z GFS/ECMWF/GEM CONTINUE TO DIG UPPER LEVEL TROUGH OVER THE OHIO RIVER VALLEY SATURDAY INTO EARLY NEXT WEEK. TIMING DIFFERENCES ON EACH INDIVIDUAL IMPULSE EMBEDDED IN THE NORTHWEST FLOW ALOFT ARE INDICATED BETWEEN THE MODELS THROUGH THIS PERIOD. WILL CONTINUE WITH TREND OF PERIODIC SMALL CHANCES OF PRECIPITATION SATURDAY THROUGH TUESDAY. TEMPERATURES THROUGH THE PERIOD ARE EXPECTED TO BE SLIGHTLY BELOW NORMAL OR NEAR NORMAL...AS NORTHERLY FLOW ALOFT ADVECTS COOLER AIRMASS INTO THE FORECAST AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1141 PM CDT TUE JUN 23 2015 THE FRONT REMAINS OVER CENTRAL KANSAS INTO CENTRAL MISSOURI LATE THIS EVENING. CONVECTION HAS FORMED NEAR AN AREA OF LOW PRESSURE OVER EASTERN COLORADO AND WAS MOVING EAST ALONG AND NORTH OF THE FRONT. NO MODEL IS PICKING UP ON THIS CONVECTION WITH THE 24.00Z NAM AND 24.03Z HRRR COMPLETELY WHIFFING ON THIS. THE 24.00Z SPC WRF AT LEAST SHOWED THIS BUT THEN DIES IT OUT IN FAVOR OF DEVELOPING CONVECTION OVER EASTERN NEBRASKA AND SOUTHERN IOWA...WHICH IS WHERE THE NAM AND HRRR ALSO TRY TO INITIATE OVERNIGHT. WITH BOTH SCENARIOS...THE CONVECTION WILL STAY TO THE SOUTH TONIGHT BUT IT WILL IMPACT HOW FAR NORTH THE FRONT CAN PROGRESS WEDNESDAY. THE NAM WITH THE 00Z RUN IS EVEN FARTHER NORTH WITH DEVELOPMENT LATE WEDNESDAY AFTERNOON AND EVENING THAN WHAT THE 18Z RUN WAS. THE SPC WRF SUGGESTS THE FRONT STAYS WELL TO THE SOUTH WITH DEVELOPMENT OCCURRING ACROSS SOUTHERN NEBRASKA AND IOWA INTO NORTHERN MISSOURI. THE 24.00Z GFS LOOKS TO BE IN BETWEEN THESE OTHER TWO SOLUTIONS WITH MOST OF THE ACTIVITY OVER THE NORTHERN HALF OF IOWA. WITH TWO OUT THREE OF THE NEW MODEL RUNS KEEPING THE CONVECTION SOUTH OF THE AREA WEDNESDAY...PLAN TO TO DO THE SAME WITH THE UPCOMING TAFS. && .HYDROLOGY... ISSUED AT 346 AM CDT WED JUN 24 2015 THE RECENT RAINFALL THAT OCCURRED MONDAY MORNING NEAR THE MINNESOTA/IOWA BORDER HAS CAUSED HIGH RIVER LEVELS ON AREA RIVERS AND STREAMS. MANY OF THE RIVERS HAVE BEGUN TO RECEDE...HOWEVER SOME FLOODING REMAINS ALONG THE CEDAR RIVER. REFER TO THE LATEST FLOOD STATEMENTS FOR THE LATEST STAGES AND FORECAST. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DTJ LONG TERM...DTJ AVIATION...04 HYDROLOGY...DTJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1141 PM CDT TUE JUN 23 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 341 PM CDT TUE JUN 23 2015 CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED SUBTROPICAL RIDGING ENCOMPASSING THE SOUTHERN U.S.. WHILE A WEST-NORTHWEST FLOW RUNS FROM THE PACIFIC NORTHWEST INTO THE MID- ATLANTIC. THE TWO MAIN SHORTWAVES OF NOTE WERE OVER THE SIOUX FALLS AREA AND SOUTHERN BRITISH COLUMBIA. THE ONE IN SIOUX FALLS ALONG WITH A WIDE AREA OF LOW TO MID LEVEL FRONTOGENESIS WAS HELPING TO PRODUCE PLENTY OF ALTOSTRATUS FROM SOUTH DAKOTA/NEBRASKA EAST INTO THE SOUTHERN PORTION OF THE FORECAST AREA. AIRMASS HAS BEEN TOO DRY TO SUPPORT ANY PRECIPITATION DESPITE SEEING ECHOES ON RADAR...AS REFLECTED BY THE 12Z MPX SOUNDING WITH A 700MB DEWPOINT DEPRESSION OF 40C. ONLY A VERY FEW SITES HAVE REPORTED SPRINKLES. MAIN SURFACE FRONTAL BOUNDARY ASSOCIATED WITH THE FRONTOGENESIS WAS WELL TO THE SOUTH...SITUATED JUST SOUTH OF I-70 AND WAS VERY SLOWLY LIFTING NORTH TODAY. THAT NORTHWARD PROGRESS HAS BEEN HELD BACK BY A PERSISTENT COMPLEX OF CONVECTION FROM SOUTHEAST NEBRASKA INTO THE KANSAS CITY AREA. SUNSHINE TODAY COMBINED WITH 850MB TEMPS AROUND 10C HAS RESULTED IN HIGHS MOSTLY IN THE 70S. MUCH LOWER DEWPOINTS TODAY THAN YESTERDAY WITH MIXING AND DRY AIR RESULTING IN READINGS OF 45 TO 55F. LOOK FOR A CONTINUATION OF QUIET CONDITIONS TONIGHT ACROSS THE FORECAST AREA AS THE AREA OF HIGH PRESSURE HELPING TO PROVIDE THE DRY CONDITIONS ONLY DRIFTS OFF TO THE SOUTHEAST. WE WILL HAVE TO DEAL WITH THE SOME HIGHER BASED FRONTOGENESIS...YIELDING SOME ALTOSTRATUS AS WE ARE SEEING TODAY. THESE CLOUDS SHOULD HELP TO PRECLUDE FOG FORMATION...AND ALSO KEEP TEMPERATURES FROM FALLING BELOW THE MID 50S. THE MORE INTERESTING PART OF THE SHORT TERM IS FOR WEDNESDAY. MODELS CONTINUE TO ADVERTISE THAT THE FRONTAL BOUNDARY IN KANSAS WILL LIFT NORTHWARD OVER THE NEXT 24 HOURS...IN RESPONSE TO A MONSOONAL SHORTWAVE COMING OUT OF COLORADO AND ROTATING AROUND THE SOUTHERN U.S. SUBTROPICAL RIDGE. AS THIS OCCURS WITH THE NOCTURNAL LOW LEVEL JET...MODELS ARE ADVERTISING AT LEAST CONVECTION IF NOT AN MCS TO DEVELOP OVER EASTERN NEBRASKA AND WESTERN IOWA LATE TONIGHT. CORFIDI VECTORS WOULD TAKE THIS MCS INTO NORTHERN MO WEDNESDAY MORNING... HOLDING THE FRONT BACK. HOWEVER...SOME GUIDANCE LIKE THE 23.12Z GFS/NAM WANT TO KEEP MOVING THE FRONT NORTH INTO THE AFTERNOON... SPREADING EITHER PREVIOUS OR NEW CONVECTION INTO NORTHEAST IA AND SOUTHWEST WI. BELIEVE THIS IS GOING TO BE TOUGH AS CLOUD DEBRIS LIMITS DAYTIME MIXING...AND CONVECTIVE OUTFLOW HOLDS THE BOUNDARY BACK. MORE LIKELY...WHEN NEW CONVECTION FIRES IT WILL BE FARTHER SOUTH CLOSER TO THE FRONT...WHICH SHOULD BE HUNG UP NEAR THE MO/IA BORDER BY 00Z THU. THE 23.12Z ECMWF REMAINS THE FARTHEST SOUTH MODEL WITH THE FRONT AND CONVECTION...AND SEEMS MOST REASONABLE GIVEN EXPECTED CONVECTION TRACKS. THEREFORE...PRECIPITATION CHANCES ARE HIGHEST IN NORTHEAST IA BUT STILL ONLY AS MUCH AS 50 PERCENT BY LATE IN THE DAY GIVEN ANTICIPATION FOR MOST CONVECTION TO STAY SOUTH. GIVEN THE MAJORITY OF CAPE TO STAY WELL SOUTH OF THE AREA...THE SLIGHT RISK ON SPCS DAY 2 OUTLOOK WAS SHIFTED MOSTLY OUT OF THE FORECAST AREA. ITS WORTH NOTING THAT MODELS...OUTSIDE THE 23.12Z ECMWF...HAVE REALLY STRUGGLED WITH THE ONGOING CONVECTION NORTH OF THE FRONT IN THE KANSAS CITY AREA. THERE IS ALSO SOME CONCERN FOR SHOWERS AND STORMS TO FIRE NORTH OF HIGHWAY 29 WEDNESDAY AFTERNOON...RELATED TO THE SHORTWAVE IN BRITISH COLUMBIA HEADING INTO NORTHERN PORTIONS OF MN OR WI. THE ECMWF IS SLOWEST WITH THE SHORTWAVE AND THEREFORE IS DRY...WHEREAS THE GFS AND NAM ARE FASTER AND HAVE PRECIP. THE GFS/NAM ALSO HAVE HIGHER SURFACE DEWPOINTS WHICH SEEM TOO HIGH. THEREFORE...HAVE ONLY KEPT A 20 PERCENT CHANCE IN TAYLOR COUNTY LATE IN THE DAY. WITH 850MB TEMPS IN THE 12-14C RANGE AND SOME SUN LIKELY FOR AT LEAST THE MORNING HOURS...HIGHS SHOULD PUSH INTO THE MID 70S TO LOW 80S...WARMEST TO THE NORTH WHERE LONGER PERIOD OF SUN IS EXPECTED. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 341 PM CDT TUE JUN 23 2015 23.12Z ECMWF/GFS/CANADIAN MAINTAIN THE SAME LONG WAVE PATTERN THEY HAVE BEEN SHOWING THE PAST SEVERAL DAYS...WITH STRONG SUBTROPICAL RIDGING SHIFTING AND BUILDING OVER THE WESTERN U.S. ON THURSDAY...CAUSING FAIRLY DEEP TROUGHING FOR THIS TIME OF YEAR OVER THE EASTERN U.S.. THIS SHIFT IS IN RESPONSE TO THE MADDEN JULIAN OSCILLATION GOING INTO AN ANOMALOUSLY STRONG PHASE 6. WHAT THIS MEANS FOR THE FORECAST AREA IS TEMPERATURES TO HOLD AT OR NEAR SEASONABLE NORMALS...WITH PERHAPS A SLOW WARMUP LATE IN THE WEEKEND INTO EARLY NEXT WEEK. ANY GULF OF MEXICO RETURN OF MOISTURE SHOULD GET SHUTOFF WITH MOISTURE SOURCES MOSTLY TURNING TO EVAPOTRANSPIRATION AND WHAT SYSTEMS CAN BRING OFF THE PACIFIC DOWN THE RIDGE. THE MAIN FOCUS FOR PRECIPITATION REMAINS WEDNESDAY NIGHT. HOWEVER...SIMILAR TO WEDNESDAY...HOW FAR NORTH THE WARM FRONT NEAR THE IA/MO BORDER AT 00Z THU REALLY DETERMINES THE CONVECTION CHANCES. CURRENT THINKING LIES ALONG THE MORE PREFERRED ECMWF VERSUS THE BIASED NORTH GFS/NAM/SREF/CANADIAN...WHICH SUGGESTS ANOTHER MCS FORMING OVER CENTRAL IOWA WEDNESDAY EVENING...MARCHING LIKELY SOUTHEASTWARD FOLLOWING CORFIDI VECTORS. THIS IS IN LINE WITH THE HIGHEST SPC DAY 2 OUTLOOK PROBABILITIES. THE NORTHERN PART OF THIS MCS COULD CLIP OUR FAR SOUTH...THUS HAVE THE HIGHEST 50-60 PERCENT CHANCES THERE FOR THE EVENING. TRIMMED CHANCES BACK FARTHER NORTH AND AREAS NORTH OF U.S. HIGHWAY 18 MAY END UP DRY. THE LONE EXCEPTION WOULD BE NORTH OF HIGHWAY 29...CLOSER TO THAT SHORTWAVE TROUGH MARCHING ACROSS MN AND NORTHERN WI. PRECIPITATION SHOULD DIMINISH WEST TO EAST DURING THE OVERNIGHT HOURS AS THE MCS AND SHORTWAVE TROUGHS MOVE FURTHER AWAY FROM THE AREA. FOR THURSDAY AND FRIDAY...THE 23.12Z GFS AND TO A LESSER EXTENT THE NAM WANT TO FIRE UP SOME DIURNAL SHOWERS AND STORMS...ASSOCIATED WITH WEAK SHORTWAVES DROPPING THROUGH THE NORTHWEST FLOW. THE 23.12Z ECMWF SHOWS THESE SAME SHORTWAVES BUT IS DRY. MUCH OF THE DIFFERENCE RELATES TO BOUNDARY LAYER MOISTURE AND ITS IMPACT TO CAPE. AT BOTH 00Z FRI AND 00Z SAT...THE GFS IS NEARLY 10F HIGHER ON SURFACE DEWPOINTS TO THE ECMWF. THINKING THE ECMWF IS MORE CORRECT AND THUS HAVE ONLY 20-30 PERCENT CHANCES AT MOST...HIGHEST IN WESTERN AREAS. SATURDAY LOOKS DRY WITH HIGH PRESSURE IN PLACE...BUT THEN THERE IS AN ISSUE WITH SUNDAY INTO MONDAY WITH MODELS TIMING A STRONGER SHORTWAVE TROUGH DROPPING THROUGH THE NORTHWEST FLOW. THE 23.12Z ECMWF IS FASTEST AND SPREADS SOME CONVECTION ACROSS THE AREA ON SUNDAY...WHEREAS THE 23.12Z CANADIAN/GFS WAIT UNTIL EITHER LATER SUNDAY NIGHT OR MONDAY. GIVEN THE SPREAD...HAVE KEPT A 20-40 PERCENT CHANCE FOR ALL 3 12 HOUR TIME PERIOD. NEEDLESS TO SAY A GOOD PORTION CAN PROBABLY BE DRIED OUT IN LATER FORECASTS ONCE THE TIMING GETS RESOLVED. ANOTHER NORTHWEST FLOW WAVE IS PROGGED FOR TUESDAY... RESULTING IN MORE CHANCES OF PRECIPITATION. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1141 PM CDT TUE JUN 23 2015 THE FRONT REMAINS OVER CENTRAL KANSAS INTO CENTRAL MISSOURI LATE THIS EVENING. CONVECTION HAS FORMED NEAR AN AREA OF LOW PRESSURE OVER EASTERN COLORADO AND WAS MOVING EAST ALONG AND NORTH OF THE FRONT. NO MODEL IS PICKING UP ON THIS CONVECTION WITH THE 24.00Z NAM AND 24.03Z HRRR COMPLETELY WHIFFING ON THIS. THE 24.00Z SPC WRF AT LEAST SHOWED THIS BUT THEN DIES IT OUT IN FAVOR OF DEVELOPING CONVECTION OVER EASTERN NEBRASKA AND SOUTHERN IOWA...WHICH IS WHERE THE NAM AND HRRR ALSO TRY TO INITIATE OVERNIGHT. WITH BOTH SCENARIOS...THE CONVECTION WILL STAY TO THE SOUTH TONIGHT BUT IT WILL IMPACT HOW FAR NORTH THE FRONT CAN PROGRESS WEDNESDAY. THE NAM WITH THE 00Z RUN IS EVEN FARTHER NORTH WITH DEVELOPMENT LATE WEDNESDAY AFTERNOON AND EVENING THAN WHAT THE 18Z RUN WAS. THE SPC WRF SUGGESTS THE FRONT STAYS WELL TO THE SOUTH WITH DEVELOPMENT OCCURRING ACROSS SOUTHERN NEBRASKA AND IOWA INTO NORTHERN MISSOURI. THE 24.00Z GFS LOOKS TO BE IN BETWEEN THESE OTHER TWO SOLUTIONS WITH MOST OF THE ACTIVITY OVER THE NORTHERN HALF OF IOWA. WITH TWO OUT THREE OF THE NEW MODEL RUNS KEEPING THE CONVECTION SOUTH OF THE AREA WEDNESDAY...PLAN TO TO DO THE SAME WITH THE UPCOMING TAFS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
730 PM MDT THU JUN 25 2015 .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 330 PM MDT THU JUN 25 2015 ANTICIPATED SEVERE WEATHER EVENT ONGOING THIS AFTERNOON. AFTER MORNING SEVERE THUNDERSTORMS WE ARE IN A LULL RIGHT NOW AND GETTING READY FOR ROUND TWO. CURRENTLY...MCS COMPLEX HAS CLEARED THE NEBRASKA PANHANDLE THIS AFTERNOON AND IS PUSHING OFF INTO CENTRAL NEBRASKA. LATEST RADAR MOSAIC SHOWING ISOLATED TO SCATTERED THUNDERSTORMS BEGINNING TO DEVELOP OVER NORTH CENTRAL AND NORTHEASTERN WYOMING...MOVING SOUTHEAST. LATEST MESOANALYSIS PAGE SHOWING SOUTHEAST WYOMING IN AN AREA OF UNCAPPED ENVIRONMENT...WITH SURFACE BASED CAPES BETWEEN 2500 AND 3500 J/KG. AREAS THAT SAW CONVECTION THIS MORNING ARE SEEING SOME CONVECTIVE INHIBITION RANGING FROM -50 TO -75 J/KG OVER THE NORTHERN PANHANDLE. WATER VAPOR IMAGERY SHOWING A WEAK SHORTWAVE MOVING INTO NORTH CENTRAL WYOMING THIS AFTERNOON AND THIS SHOULD BE THE CATALYST FOR MORE WIDESPREAD CONVECTION THIS AFTERNOON. FOR THE REMAINDER OF THIS AFTERNOON AND EVENING...A SCATTERED COVERAGE OF STORMS BEING FORECAST FOR AREAS EAST OF THE LARAMIE RANGE. WITH AFTERNOON HEATING...CAPE SHOULD REMAIN HIGH...IN THE 2500-3000 J/KG RANGE. LATEST HRRR SIMULATED RADAR IMAGERY SHOWING THE MAJORITY OF CONVECTION OVER THE SOUTHERN PANHANDLE THROUGH MID EVENING. ONE AREA OF CONCERN HYDRO WISE. MORNING CONVECTION OVER DAWES AND NORTHERN SIOUX COUNTIES HAVE PRIMED THIS AREA FOR POTENTIAL FLASH FLOODING. WE RECEIVED REPORTS OF UP TO AS MUCH AS 2.5 INCHES OF RAIN HAS THAT HAS ALREADY FALLEN IN DAWES COUNTY JUST SOUTH OF CHADRON. REPORTS OVER NORTHERN SIOUX AROUND AN INCH AND FURTHER WEST IN CONVERSE COUNTY...WE RECEIVED REPORTS CLOSE TO AN INCH FROM MORNING CONVECTION. WILL KEEP THE FLASH FLOOD WATCH GOING AS ANY MORE STORMS UP THERE COULD PRODUCE FLOODING CONDITIONS QUICKLY. SHORTWAVE PASSES TO THE EAST INTO WESTERN NEBRASKA AFTER 06Z THIS EVENING AND CONVECTION SHOULD COME TO AN END FROM WEST TO EAST AS THIS OCCURS THROUGH THE EVENING HOURS. CONTINUED THE POTENTIAL FOR AM FOG ESPECIALLY ACROSS THE PANHANDLE WHERE NORTHEAST WINDS WILL LINGER. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 330 PM MDT THU JUN 25 2015 RELATIVELY QUIET WEATHER THIS WEEKEND AS A STRONG UPPER LEVEL HIGH DEVELOPS NEAR THE FOUR CORNERS REGION AND GRADUALLY DRIFTS NORTHWARD OVER THE NORTHERN GREAT BASIN. MODEL SOUNDINGS CONTINUE TO INDICATE STRONG MIDLEVEL SUBSIDENCE OVER THE FORECAST AREA WHICH WILL GREATLY INHIBIT CONVECTION SATURDAY AND SUNDAY AFTERNOON. CAN NOT RULE OUT A FEW THUNDER SHOWERS OVER THE MOUNTAINS THIS WEEKEND...OTHERWISE KEPT POP BELOW 10 PERCENT OVER THE HIGH PLAINS. ALTHOUGH PRECIPITATION CHANCES WILL BE LOW...DEWPOINTS WILL BE HIGH EAST OF THE LARAMIE RANGE WITH PRETTY HIGH RELATIVE HUMIDITIES. HOWEVER...SUBSIDENCE ALOFT WILL BE TOO GREAT TO OVERCOME FOR DEEP CONVECTION. THIS MAY CHANGE BY EARLY NEXT WEEK AS THE UPPER LEVEL HIGH DRIFTS TO THE WEST AND WEAKENS...ALLOWING SHORTWAVE ACTIVITY AND A MORE FAVORABLE SHEAR PROFILE TO ENTER THE FORECAST AREA. INCREASED POP TUESDAY THROUGH THURSDAY...WITH THE HIGHEST POTENTIAL FOR TSTORMS OVER SOUTHEAST WYOMING. HIGH TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE NORMAL FOR THIS TIME OF THE YEAR WITH HIGHS IN THE 80S TO NEAR 90. MODELS THEN INDICATE A COOL FRONT QUICKLY MOVING SOUTHWARD ACROSS THE AREA BY WEDNESDAY EVENING...WHICH MAY RESULT IN TEMPERATURES SLIGHTLY BELOW NORMAL BY THE END OF NEXT WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH FRIDAY AFTERNOON) THE STRONGEST THUNDERSTORMS HAVE PUSHED EAST OF KSNY AND KBFF THIS EVENING. IFR CONDITIONS AND HEAVY RAIN WILL BE POSSIBLE OVER THE NEXT FEW HOURS UNTIL THUNDERSTORMS DISSIPATE AFTER 03Z. AFTER A BRIEF BREAK...IFR CONDITIONS MAY RETURN TO LOCATIONS EAST OF THE LARAMIE RANGE DUE TO LOW CLOUDS AND FOG. PATCHY FOG AND LOW CIGS WILL CONTINUE INTO EARLY FRIDAY MORNING. && .FIRE WEATHER... ISSUED AT 330 PM MDT THU JUN 25 2015 ACTIVE WEATHER TODAY AS SCATTERED SHOWERS AND THUNDERSTORMS WILL IMPACT MUCH OF SOUTHEAST WYOMING AND NEBRASKA PANHANDLE. THESE STORMS LOOK TO GRADUALLY DECREASE AS THE EVENING PROGRESSES. A DRIER DAY ON TAP FOR FRIDAY AS THE FRONT THATS CURRENTLY OVER THE AREA MOVES EAST. NICE AND DRY WEATHER FOR THE WEEKEND WITH AFTERNOON HUMIDITIES IN THE UPPER TEENS WEST OF THE LARAMIE RANGE AND LOWER 30S EAST. NO FIRE WEATHER CONCERNS AS AREA FUELS ARE RATED NONRECEPTIVE TO LARGE FIRE GROWTH. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...FLASH FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR WYZ102. NE...FLASH FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR NEZ002-095. && $$ SHORT TERM...GCC LONG TERM...TJT AVIATION...TJT FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
1247 AM CDT FRI JUN 26 2015 .AVIATION...26/06Z TAF CYCLE VFR CONDS WL PREVAIL THRU THE MRNG HRS ACRS THE FA. A CDFNT IS FCST TO MOVE INTO NRN AR FRI AFTN. SCTD SHRA/TSRA WL DVLP ALONG THE FNT...PRODUCING MAINLY MVFR CONDS. CONVECTION WL BCM MORE ORGANIZED AS IT SHIFTS SWD INTO CNTRL AR BY EARLY FRI EVENING... AND EVENTUALLY AFFECTING SRN AR LATE IN THE FCST PD. /44/ && .PREV DISCUSSION... /ISSUED 220 PM CDT THU JUN 25 2015/ SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT TODAY...HAVE CONTINUED TO SEE A FEW CLOUDS BEGIN TO POP IN THE HEAT OF THE DAY...GENERALLY ACROSS SOUTHERN ARKANSAS. WITHIN THE PAST HOUR OR TWO... HAVE BEGUN TO SEE A FEW SHOWERS AND THUNDERSTORMS FIRE IN NORTHERN LOUISIANA. AT THIS TIME...DO HAVE POPS ACROSS SOUTHERN ARKANSAS. HRRR SUGGESTS STORMS COULD FIRE AS FAR NORTH AS LITTLE ROCK...BUT DO HAVE SOME DOUBTS THAT CENTRAL ARKANSAS WILL SEE RAIN. AS A RESULT...KEPT SLIGHT CHANCE POPS LIMITED TO SOUTHERN ARKANSAS. UPPER LEVEL RIDGE HAS BEGUN TO RETROGRADE TO THE WEST WITH WESTERLY FLOW SETTING UP ALOFT. NORTHWESTERLY FLOW WILL BE MOVING INTO THE REGION AND HELP TO DRIVE A FRONT INTO THE STATE ON FRIDAY. 12Z WRF SUGGESTS PRECIP WILL BE IN PLACE ACROSS NORTHERN ARKANSAS BEFORE 12Z ON FRIDAY. DO THINK THE FRONT WILL BE A BIT QUICKER THAN THE MODELS SUGGEST...BUT BELIEVE THE WRF IS MUCH TOO QUICK. THEREFORE JUST KEPT CHANCE POPS MENTIONED ACROSS NORTHERN ARKANSAS DURING THE MORNING HOURS. AMPLE CAPE WILL BE AVAILABLE AHEAD OF THE FRONT ON FRIDAY WITH DEEP LAYER SHEAR AROUND 30 KNOTS. MID LEVEL LAPSE RATES...WILL NOT BE OUTRAGEOUS...BUT DO EXPECT DAMAGING WIND GUSTS TO BE THE PRIMARY THREAT. IT DOES APPEAR THE COLD FRONT WILL CLEAR THE STATE BY MID MORNING ON FRIDAY WITH DRY AND NOTICEABLY COOLER AND DRIER AIR FILTERING INTO THE STATE. DRY WEATHER WILL BE SHORT LIVED AS THE NEXT CHANCE FOR PRECIPITATION MOVES INTO NORTHERN ARKANSAS AS THE SHORT TERM ENDS. LONG TERM...MONDAY THROUGH THURSDAY FLOW ALOFT WILL BE FROM THE NW OVER THE REGION AT THE START OF THE LONG TERM PERIOD AS AN ELONGATED UPPER RIDGE WILL BE OVER THE ROCKIES...WITH A TROUGH OVER THE GREAT LAKES REGION. A NEW COLD FRONT WILL SLOW OVER PORTIONS OF THE STATE...WITH CHANCES FOR SHOWERS AND THUNDERSTORMS RETURNING. INITIALLY...BEST POPS WILL BE ACROSS THE NRN COUNTIES...BUT DO THINK SOME CHANCES FOR PRECIP WILL EXIST FURTHER SOUTH BY LATE MON INTO TUE WITH THE FRONT WASHING OUT. SRLY FLOW WILL RETURN FOR TUE AND THROUGH MUCH OF THE REST OF THE FORECAST...WHICH WILL ALLOW FOR TEMPS TO INCREASE FROM JUST BELOW NORMAL...TO AROUND NORMAL FOR MUCH OF NEXT WEEK. CHANCES FOR DIURNALLY DRIVEN CONVECTION WILL BE SEEN...ESPECIALLY WITH THE UPPER RIDGE REMAINING WEST OF THE STATE...AND AR IN GENERAL NW FLOW ALOFT. BY THE END OF NEXT WEEK...ANOTHER COLD FRONT WILL ATTEMPT TO MOVE INTO THE STATE...WITH ANOTHER SHOT OF COOLER AIR AND MORE CHANCES FOR PRECIP. && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1035 PM MST THU JUN 25 2015 .UPDATE...UPDATED AVIATION DISCUSSION... .SYNOPSIS... ABOVE NORMAL TEMPERATURES WILL PERSIST ACROSS THE REGION THROUGH THE WEEKEND. THUNDERSTORMS ARE EXPECTED TO BE LARGELY CONFINED TO THE WHITE MOUNTAINS AND SOUTHEAST ARIZONA THROUGH SATURDAY...BUT WITH STRONG WINDS AND AREAS OF BLOWING DUST POSSIBLE ON THE LOWER DESERTS DUE TO DISTANT STORMS. MORE HUMID AIR IS ANTICIPATED TO OVERSPREAD THE REGION BEGINNING LATER IN THE WEEKEND WITH STORM CHANCES EXPANDING TO MANY LOWER DESERT LOCATIONS BY EARLY NEXT WEEK. THE INCREASE IN MONSOON STORM ACTIVITY COULD LEAD TO SLIGHTLY COOLER DAYTIMES BUT WARMER OVERNIGHTS. && .DISCUSSION... AS EXPECTED...TODAY WAS NOT QUITE AS ACTIVE ACROSS OUR CWA THEN WHAT WE SAW YESTERDAY...WHEN A WEAK INVERTED TROF HELPED TO TRIGGER THUNDERSTORM ACTIVITY ACROSS THE HIGHER TERRAIN OF SOUTH-CENTRAL ARIZONA...WHICH GENERATED AN OUTFLOW BOUNDARY THAT MOVED WESTWARD INTO THE GREATER PHOENIX AREA. ALTHOUGH A FEW STORMS DID AGAIN DEVELOP OVER GILA COUNTY...TODAY/S ACTIVITY WAS MORE FOCUSED OVER SE AZ...WITH TUCSON INTERNATIONAL AIRPORT SEEING WIND GUSTS UP TO 60 MPH FROM NEARBY THUNDERSTORMS. ALTHOUGH OUTFLOWS FROM THE STORMS OVER THE TUCSON AREA DID ATTEMPT TO MOVE NORTHWARD...THEY PRETTY MUCH DISSIPATED WELL TO THE SOUTH OF OUR CWA. ANOTHER AREA THAT ACTUALLY SAW A FEW SPRINKLES TODAY...WITH CONSIDERABLE CLOUDINESS THAT KEPT HIGHS DOWN AT/BELOW 100 WAS THE YUMA AREA. THE CLOUDINESS OVER THAT AREA IS NOW BEGINNING TO THIN/CLEAR AS THE MOISTURE PLUME IS PUSHED OFF TO THE WEST. AS FAR AS THE FORECAST FOR THE REST OF THE NIGHT AND EARLY FRIDAY IS CONCERNED...IT SHOULD BE PRETTY QUIET...WITH THE LATEST HRRR KEEPING CONVECTIVE ACTIVITY PRETTY MUCH OVER THE TUCSON CWA. OTHER THAN SOME MINOR ADJUSTMENTS TO HOURLY TRENDS...INHERITED FORECASTS ARE LOOKING GOOD. && .PREVIOUS DISCUSSION... STRONG HIGH PRESSURE ALOFT WAS SITUATED OVER THE DESERT SOUTHWEST EARLY THIS AFTERNOON WITH THE UPPER HIGH CENTER LOCATED OVER FAR NCENTRAL ARIZONA NEAR THE UTAH BORDER. H5 HEIGHTS REMAINED HIGH ACROSS SRN AZ...NEAR 592DM AND UNDER MOSTLY SUNNY SKIES THE CENTRAL DESERTS WERE RAPIDLY CLIMBING TOWARDS 110 DEGREES AS OF 1 PM. SURFACE DEWPOINTS OVER THE CENTRAL DESERTS WERE ELEVATED EARLY THIS AFTERNOON COMPARED TO 24 HOURS AGO...RANGING FROM UPPER 40S TO MID 50S...BUT THEY WILL LIKELY DROP ANOTHER FEW DEGREES BY LATE AFTERNOON AND WILL BE TOO LOW TO SUPPORT DESERT CONVECTION. RADAR AS WELL AS IR/LIGHTNING IMAGERY SHOWED A FEW STORMS DEVELOPING OVER FAR SERN AZ AND THE WHITE MOUNTAINS BUT LITTLE WAS HAPPENING CONVECTIVELY OVER SRN GILA COUNTY. PART OF THE REDUCTION IN CONVECTION IS DUE TO THE COOLER TEMPS TODAY COMPARED TO YESTERDAY. FOR TONIGHT THROUGH FRIDAY NIGHT...THE STRONG UPPER HIGH WILL REMAIN CENTERED TO OUR NORTH...GIVING THE SRN DESERTS A WEAK ELY STEERING FLOW MOSTLY AOB 15KT. MODEL GUIDANCE IS CONSISTENT IN CALLING FOR LIMITED MOISTURE AND INSTABILITY OVER THE LOWER DESERTS...WITH CAPE VALUES MOSTLY BELOW 200J/KG. THE STRENGTH OF THE UPPER HIGH WILL ACT TO CAP CONVECTION SOMEWHAT OVER OUR AREA WITH THE ONLY REAL THREAT FOR STORMS TO FOCUS OVER THE HIGHER TERRAIN OF SOUTHERN GILA COUNTY. ESSENTIALLY WE ARE LOOKING AT LOW GRADE MONSOON CONDITIONS TONIGHT THROUGH FRIDAY NIGHT WITH SLIGHT CHANCES ACROSS ZONE 24 AND SINGLE DIGIT POPS ELSEWHERE. GIVEN THE RATHER LOW GRADE CONDITIONS...THE THREAT OF BLOWING DUST INTO NRN PINAL COUNTY OR THE EAST VALLEY WILL BE MINIMAL AS WELL. LOW GRADE MONSOON CONDITIONS WILL ALSO CONTINUE DURING THE DAY ON SATURDAY. UNDER PARTLY TO MOSTLY SUNNY SKIES FRIDAY INTO SATURDAY...HIGH TEMPS WILL STAY WELL ABOVE SEASONAL NORMALS WITH MOST OF THE HOTTER DESERTS REACHING OR EXCEEDING 110 DEGREES. WE EXPECT HIGHS TO STAY SLIGHTLY BELOW EXCESSIVE HEAT WARNING CRITERIA HOWEVER. OVERNIGHT SATURDAY INTO SUNDAY A DEEPER MOISTURE FROM THE EAST WILL OVERSPREAD THE AREA...INCREASING CHANCES FOR SHOWER AND THUNDERSTORM ACTIVITY FOR THE LATE WEEKEND AND EARLY NEXT WEEK. FLOW THROUGH THE 700-500MB LAYER BECOMES A BIT MORE UNIDIRECTIONAL FROM THE SOUTHEAST AND ELEVATED IN VELOCITY ACROSS SOUTHEAST AZ FIRST ON SUNDAY BUT THEN EXPANDS INTO SOUTH-CENTRAL AND SOUTHWEST AZ LATER INTO THE DAY ON MONDAY. PWATS NEAR THE 1.25 INCH MARK AND 850MB DEWPOINTS ARE PROGGED INTO THE 8-10C RANGE ACROSS THE NORTHERN CWA TIER AND 10C+ ACROSS SW AZ AND SOUTHERN CWA BORDER. A GRADUAL SHIFT IN THE 500MB HIGH CENTER FURTHER TO THE NORTH ACROSS THE INTERMOUNTAIN WEST COULD ALLOW FOR MORE INVERTED TROUGHING TO SKIRT ALONG ITS SOUTHERN PERIPHERY AND RIGHT THROUGH THE SOUTHWEST DURING THIS TIME FRAME. CONCEPTUALLY WITH THE INCREASE IN THE MOISTURE AND DEEP EASTERLY FLOW THROUGH THE MID AND UPPER LEVELS OF THE PROFILE...STORM ACTIVITY HAS THE POTENTIAL TO INCREASE ACROSS ARIZONA FOR SUNDAY AND CWA-WIDE BY MONDAY AS MOISTURE REACHES BEYOND THE CO RIVER VALLEY. ELEVATED DEWPOINTS AND EASTERLY FLOW ALOFT WARRANT CONTINUED ABOVE CLIMO POPS FOR NEXT WEEK...HOWEVER ONE DAY`S FORECAST MAY BE OFFSET BY THE PREVIOUS NIGHT`S ACTIVITY. DAYTIME TEMPERATURES WILL GRADUALLY TREND COOLER AND CLOSER TOWARD SEASONAL NORMALS WHILE THE OVERNIGHTS WILL REMAIN ON THE MILD TO WARM SIDE. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... OUTFLOWS FROM DECAYING THUNDERSTORMS OVER THE TUCSON AREA ARE EXPECTED TO REACH THE GREATER PHX AREA DURING THE NEXT HOUR OR TWO...WITH A PERIOD OF GUSTY SE-LY WINDS LIKELY AS THE BOUNDARY PASSES THROUGH EACH TAF SITE. AS THIS POINT...IT DOES NOT APPEAR THAT THE WINDS WILL BE STRONG ENOUGH TO PRODUCE SIGNIFICANT BLOWING DUST. WINDS WILL THEN REVERT BACK TO TYPICAL DIURNAL DIRECTIONS/SPEEDS AT ALL OF THE PHOENIX TAF SITES LATER TONIGHT AND ON FRIDAY. SCT-BKN MID TO HIGH LEVEL CIGS TO PREVAIL THROUGH THE TAF PERIOD AT ALL OF THE TERMINALS. SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... MOSTLY CLEAR SKIES AND LIGHT/DIURNALLY DRIVEN WINDS EXPECTED AT BOTH TAF SITES THROUGH FRIDAY. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SATURDAY THROUGH WEDNESDAY... STORM CHANCES WILL BE CONFINED TO THE HIGHER TERRAIN LOCATIONS OF EASTERN ARIZONA TO FINISH OUT THE WEEK BEFORE STORM CHANCES EXPAND ACROSS THE AREA EARLY NEXT WEEK. STRONG WINDS AND LIGHTNING WILL GRADUALLY BECOME MORE LIKELY DURING THIS TIME FRAME WITH WETTING RAINS TENDING TO BE LOCALIZED. ACCORDINGLY...HUMIDITIES WILL BE TRENDING UPWARD. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...PERCHA/CB/NOLTE AVIATION...LEINS FIRE WEATHER...DEWEY
AREA FORECAST DISCUSSION
NWS TUCSON AZ
925 PM MST THU JUN 25 2015 .SYNOPSIS...THUNDERSTORM CHANCES WILL INTO EARLY NEXT WEEK AS MOISTURE INCREASES ACROSS THE AREA. HEAVIER RAINFALL SHOULD OCCUR ACROSS VALLEY LOCATIONS...AND DAYTIME TEMPERATURES WILL TREND CLOSER TO NORMAL BY EARLY NEXT WEEK. && .DISCUSSION...SCATTERED SHOWERS HAVE DEVELOPED DURING ABOUT THE PAST 30-60 MINUTES ACROSS SRN GRAHAM/NRN COCHISE COUNTIES EAST TO NORTHEAST OF TUCSON. THE REST OF SE ARIZONA WAS VOID OF PRECIP ECHOES AS PER KEMX WSR-88D AT THIS TIME. LATEST HRRR SUGGESTS THE BULK OF THIS RAINFALL WILL DISSIPATE BY AROUND DAYBREAK FRI. FOR THE REST OF TONIGHT...HAVE MAINTAINED A SLIGHT CHANCE OF SHOWERS/TSTMS MAINLY FROM TUCSON EWD/SWD TO THE NEW MEXICO/INTERNATIONAL BORDERS. CLEARING SKIES MAY THEN OCCUR AROUND DAYBREAK FRI FOLLOWED BY ANOTHER ROUND OF SHOWERS/TSTMS MAINLY EAST TO SOUTH OF TUCSON FRI AFTERNOON/EVENING. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL. && .AVIATION...VALID THRU 27/06Z. SCATTERED -SHRA WITH ISOLATED -TSRA WILL MOSTLY END AROUND 26/12Z. ISOLATED TO SCATTERED -TSRA/-SHRA WILL RETURN MAINLY EAST TO SOUTH OF KTUS FRIDAY AFTERNOON AND EVENING. BRIEF WIND GUSTS OF 40-50 KTS SHOULD ACCOMPANY THE STRONGER TSRA FRIDAY AFTERNOON. OTHERWISE... CLOUD DECKS WILL GENERALLY BE AT OR ABOVE 10K FT AGL...AND SURFACE WIND BE LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...ADEQUATE MOISTURE WILL RESULT IN DAILY THUNDERSTORM ACTIVITY INTO NEXT WEEK. FRIDAY MAY BE A BIT LESS ACTIVE DAY BUT THIS WEEKEND AND MONDAY SHOULD SEE SUBSTANTIAL STORM COVERAGE. INITIAL THUNDERSTORM HAZARDS WILL BE STRONG GUSTY OUTFLOWS AND DRY LIGHTNING UNTIL MOISTURE BECOMES MORE ENTRENCHED THIS WEEKEND. WIND GUSTS OF 35-45 MPH WILL BE FAIRLY COMMON WITH THE POTENTIAL FOR THE STRONGEST AFTERNOON AND EARLY EVENING STORMS TO PRODUCE WINDS IN EXCESS OF 50 MPH. && .PREVIOUS DISCUSSION...FOR FRIDAY...HIGH PRESSURE WILL BRIEFLY STRENGTHEN AND RECONSOLIDATE SLIGHTLY OVER NORTHERN ARIZONA WHICH WILL RESULT IN LESSER CHANCES OF SHOWERS AND THUNDERSTORMS FROM TUCSON NORTH AND WEST WITH THE BULK OF THE STORMS SOUTH AND EAST OF TUCSON AND ESPECIALLY NEAR THE NEW MEXICO AND INTERNATIONAL BORDERS. FOR THIS WEEKEND INTO NEXT WEEK...HIGH PRESSURE ALOFT WILL BE LOCATED OVER THE GREAT BASIN RESULTING IN FAVORABLE EASTERLY FLOW WITH CONSIDERABLE MOISTURE. THERE WILL BE EMBEDDED WEAK INVERTED TROUGHS IN THE FLOW TO OUR SOUTH THAT WILL LIKELY ENHANCE CONVECTION...PERHAPS SUNDAY INTO MONDAY BUT THESE ARE SMALL SCALE FEATURES THAT THE MODELS WILL HAVE A HARD TIME PICKING UP ON THIS FAR OUT. BOTTOM LINE IS PLENTY OF MOISTURE TO WORK WITH FOR AN OVERALL MID GRADE MONSOON THIS WEEKEND INTO NEXT WEEK BUT CERTAINLY ACTIVE FOR LATE JUNE. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
915 PM MST THU JUN 25 2015 .SYNOPSIS... ABOVE NORMAL TEMPERATURES WILL PERSIST ACROSS THE REGION THROUGH THE WEEKEND. THUNDERSTORMS ARE EXPECTED TO BE LARGELY CONFINED TO THE WHITE MOUNTAINS AND SOUTHEAST ARIZONA THROUGH SATURDAY...BUT WITH STRONG WINDS AND AREAS OF BLOWING DUST POSSIBLE ON THE LOWER DESERTS DUE TO DISTANT STORMS. MORE HUMID AIR IS ANTICIPATED TO OVERSPREAD THE REGION BEGINNING LATER IN THE WEEKEND WITH STORM CHANCES EXPANDING TO MANY LOWER DESERT LOCATIONS BY EARLY NEXT WEEK. THE INCREASE IN MONSOON STORM ACTIVITY COULD LEAD TO SLIGHTLY COOLER DAYTIMES BUT WARMER OVERNIGHTS. && .DISCUSSION... AS EXPECTED...TODAY WAS NOT QUITE AS ACTIVE ACROSS OUR CWA THEN WHAT WE SAW YESTERDAY...WHEN A WEAK INVERTED TROF HELPED TO TRIGGER THUNDERSTORM ACTIVITY ACROSS THE HIGHER TERRAIN OF SOUTH-CENTRAL ARIZONA...WHICH GENERATED AN OUTFLOW BOUNDARY THAT MOVED WESTWARD INTO THE GREATER PHOENIX AREA. ALTHOUGH A FEW STORMS DID AGAIN DEVELOP OVER GILA COUNTY...TODAY/S ACTIVITY WAS MORE FOCUSED OVER SE AZ...WITH TUCSON INTERNATIONAL AIRPORT SEEING WIND GUSTS UP TO 60 MPH FROM NEARBY THUNDERSTORMS. ALTHOUGH OUTFLOWS FROM THE STORMS OVER THE TUCSON AREA DID ATTEMPT TO MOVE NORTHWARD...THEY PRETTY MUCH DISSIPATED WELL TO THE SOUTH OF OUR CWA. ANOTHER AREA THAT ACTUALLY SAW A FEW SPRINKLES TODAY...WITH CONSIDERABLE CLOUDINESS THAT KEPT HIGHS DOWN AT/BELOW 100 WAS THE YUMA AREA. THE CLOUDINESS OVER THAT AREA IS NOW BEGINNING TO THIN/CLEAR AS THE MOISTURE PLUME IS PUSHED OFF TO THE WEST. AS FAR AS THE FORECAST FOR THE REST OF THE NIGHT AND EARLY FRIDAY IS CONCERNED...IT SHOULD BE PRETTY QUIET...WITH THE LATEST HRRR KEEPING CONVECTIVE ACTIVITY PRETTY MUCH OVER THE TUCSON CWA. OTHER THAN SOME MINOR ADJUSTMENTS TO HOURLY TRENDS...INHERITED FORECASTS ARE LOOKING GOOD. && .PREVIOUS DISCUSSION... STRONG HIGH PRESSURE ALOFT WAS SITUATED OVER THE DESERT SOUTHWEST EARLY THIS AFTERNOON WITH THE UPPER HIGH CENTER LOCATED OVER FAR NCENTRAL ARIZONA NEAR THE UTAH BORDER. H5 HEIGHTS REMAINED HIGH ACROSS SRN AZ...NEAR 592DM AND UNDER MOSTLY SUNNY SKIES THE CENTRAL DESERTS WERE RAPIDLY CLIMBING TOWARDS 110 DEGREES AS OF 1 PM. SURFACE DEWPOINTS OVER THE CENTRAL DESERTS WERE ELEVATED EARLY THIS AFTERNOON COMPARED TO 24 HOURS AGO...RANGING FROM UPPER 40S TO MID 50S...BUT THEY WILL LIKELY DROP ANOTHER FEW DEGREES BY LATE AFTERNOON AND WILL BE TOO LOW TO SUPPORT DESERT CONVECTION. RADAR AS WELL AS IR/LIGHTNING IMAGERY SHOWED A FEW STORMS DEVELOPING OVER FAR SERN AZ AND THE WHITE MOUNTAINS BUT LITTLE WAS HAPPENING CONVECTIVELY OVER SRN GILA COUNTY. PART OF THE REDUCTION IN CONVECTION IS DUE TO THE COOLER TEMPS TODAY COMPARED TO YESTERDAY. FOR TONIGHT THROUGH FRIDAY NIGHT...THE STRONG UPPER HIGH WILL REMAIN CENTERED TO OUR NORTH...GIVING THE SRN DESERTS A WEAK ELY STEERING FLOW MOSTLY AOB 15KT. MODEL GUIDANCE IS CONSISTENT IN CALLING FOR LIMITED MOISTURE AND INSTABILITY OVER THE LOWER DESERTS...WITH CAPE VALUES MOSTLY BELOW 200J/KG. THE STRENGTH OF THE UPPER HIGH WILL ACT TO CAP CONVECTION SOMEWHAT OVER OUR AREA WITH THE ONLY REAL THREAT FOR STORMS TO FOCUS OVER THE HIGHER TERRAIN OF SOUTHERN GILA COUNTY. ESSENTIALLY WE ARE LOOKING AT LOW GRADE MONSOON CONDITIONS TONIGHT THROUGH FRIDAY NIGHT WITH SLIGHT CHANCES ACROSS ZONE 24 AND SINGLE DIGIT POPS ELSEWHERE. GIVEN THE RATHER LOW GRADE CONDITIONS...THE THREAT OF BLOWING DUST INTO NRN PINAL COUNTY OR THE EAST VALLEY WILL BE MINIMAL AS WELL. LOW GRADE MONSOON CONDITIONS WILL ALSO CONTINUE DURING THE DAY ON SATURDAY. UNDER PARTLY TO MOSTLY SUNNY SKIES FRIDAY INTO SATURDAY...HIGH TEMPS WILL STAY WELL ABOVE SEASONAL NORMALS WITH MOST OF THE HOTTER DESERTS REACHING OR EXCEEDING 110 DEGREES. WE EXPECT HIGHS TO STAY SLIGHTLY BELOW EXCESSIVE HEAT WARNING CRITERIA HOWEVER. OVERNIGHT SATURDAY INTO SUNDAY A DEEPER MOISTURE FROM THE EAST WILL OVERSPREAD THE AREA...INCREASING CHANCES FOR SHOWER AND THUNDERSTORM ACTIVITY FOR THE LATE WEEKEND AND EARLY NEXT WEEK. FLOW THROUGH THE 700-500MB LAYER BECOMES A BIT MORE UNIDIRECTIONAL FROM THE SOUTHEAST AND ELEVATED IN VELOCITY ACROSS SOUTHEAST AZ FIRST ON SUNDAY BUT THEN EXPANDS INTO SOUTH-CENTRAL AND SOUTHWEST AZ LATER INTO THE DAY ON MONDAY. PWATS NEAR THE 1.25 INCH MARK AND 850MB DEWPOINTS ARE PROGGED INTO THE 8-10C RANGE ACROSS THE NORTHERN CWA TIER AND 10C+ ACROSS SW AZ AND SOUTHERN CWA BORDER. A GRADUAL SHIFT IN THE 500MB HIGH CENTER FURTHER TO THE NORTH ACROSS THE INTERMOUNTAIN WEST COULD ALLOW FOR MORE INVERTED TROUGHING TO SKIRT ALONG ITS SOUTHERN PERIPHERY AND RIGHT THROUGH THE SOUTHWEST DURING THIS TIME FRAME. CONCEPTUALLY WITH THE INCREASE IN THE MOISTURE AND DEEP EASTERLY FLOW THROUGH THE MID AND UPPER LEVELS OF THE PROFILE...STORM ACTIVITY HAS THE POTENTIAL TO INCREASE ACROSS ARIZONA FOR SUNDAY AND CWA-WIDE BY MONDAY AS MOISTURE REACHES BEYOND THE CO RIVER VALLEY. ELEVATED DEWPOINTS AND EASTERLY FLOW ALOFT WARRANT CONTINUED ABOVE CLIMO POPS FOR NEXT WEEK...HOWEVER ONE DAY`S FORECAST MAY BE OFFSET BY THE PREVIOUS NIGHT`S ACTIVITY. DAYTIME TEMPERATURES WILL GRADUALLY TREND COOLER AND CLOSER TOWARD SEASONAL NORMALS WHILE THE OVERNIGHTS WILL REMAIN ON THE MILD TO WARM SIDE. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... STORMS EXPECTED AGAIN THIS AFTERNOON BUT THERE SHOULD BE MUCH LESS COVERAGE AND MUCH LOWER CHANCES OF OUTFLOWS MAKING THEIR WAY THROUGH THE METRO AREA. THUS...GOING WITH TYPICAL DIURNAL WINDS AT ALL PHOENIX TAF SITES. LIKELY LOOKING AT SOME AFTERNOON/EARLY EVENING GUSTINESS OUT OF THE WEST EVENTUALLY TURNING AROUND OUT OF THE EAST RIGHT BEFORE 12Z FRIDAY. SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... MOSTLY CLEAR SKIES AND LIGHT/DIURNALLY DRIVEN WINDS EXPECTED AT BOTH TAF SITES THROUGH THURSDAY. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SATURDAY THROUGH WEDNESDAY... STORM CHANCES WILL BE CONFINED TO THE HIGHER TERRAIN LOCATIONS OF EASTERN ARIZONA TO FINISH OUT THE WEEK BEFORE STORM CHANCES EXPAND ACROSS THE AREA EARLY NEXT WEEK. STRONG WINDS AND LIGHTNING WILL GRADUALLY BECOME MORE LIKELY DURING THIS TIME FRAME WITH WETTING RAINS TENDING TO BE LOCALIZED. ACCORDINGLY...HUMIDITIES WILL BE TRENDING UPWARD. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...PERCHA/CB/NOLTE AVIATION...LEINS FIRE WEATHER...DEWEY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
457 AM EDT FRI JUN 26 2015 .SYNOPSIS... 08Z WATER VAPOR AND H4 RAP ANALYSIS ARE SHOWING THE BEGINNING STAGES OF A SIGNIFICANT UPPER LEVEL PATTERN AMPLIFICATION THAT WILL COMPLETE DURING THE UPCOMING WEEKEND. CURRENT PATTERN CONSISTS OF RIDGING OVER THE INTER-MOUNTAIN WEST INTO SOUTHWEST CANADA...WITH THE NORTHERN STREAM FLOW THEN DIPPING SOUTHWARD ACROSS THE UPPER MIDWEST AND OHIO VALLEY. AS MENTIONED ABOVE...THIS IS JUST THE BEGINNING TO A MUCH GREATER AMPLIFICATION. SHORTWAVE ENERGY CURRENTLY MOVING THROUGH THE NORTHERN PLAINS IS FORECAST TO SHARPEN AND EVENTUALLY CUT OFF AS IT MOVES EASTWARD DURING THE NEXT 24-30 HOURS. THIS WILL RESULT IN AN UNUSUALLY PATTERN FOR THE END OF JUNE SUPPORTIVE OF A DEEP SURFACE CYCLONE OVER THE OHIO VALLEY BY LATE SATURDAY. CURRENTLY WE FIND THE SUBTROPICAL SURFACE RIDGE AXIS IN A POSITION ACROSS THE CENTRAL FLORIDA PENINSULA/EASTERN GULF OF MEXICO...HOWEVER THIS RIDGE WILL BE SETTLING SOUTHWARD TODAY INTO TONIGHT AS THE AMPLIFICATION EVOLVES INTO THE EASTERN CONUS. CONDITIONS ARE CURRENTLY QUIET AND DRY ACROSS THE FORECAST AREA...AND OTHER THAN A FEW ISOLATED SHOWERS UP TOWARD LEVY COUNTY...ANTICIPATE THESE QUIET CONDITIONS TO CONTINUE FOR AT LEAST A FEW HOURS AFTER SUNRISE. THEREAFTER...THE TYPICAL DAILY SEA BREEZE AND ASSOCIATED SCT CONVECTION WILL BEGIN TO EVOLVE. && .SHORT TERM... TODAY... AS THE SURFACE RIDGE AXIS SLOWLY SETTLES SOUTHWARD TODAY...THIS WILL PRESENT OUR FORECAST AREA WITH A GENERAL LIGHT SOUTHWESTERLY LOW LEVEL FLOW REGIME...WITH THE MOST DEFINED SOUTHWEST FLOW ACROSS THE NATURE COAST ZONES. SOUTHWEST FLOW REGIME DAYS TEND TO RESULT IN A SCATTERING OF STORMS ALONG THE COAST DURING THE LATE MORNING/EARLY AFTERNOON HOURS...WITH THE MAJORITY OF THE CONVECTION THEN MIGRATING RAPIDLY INLAND WITH THE SEA BREEZE FOR THE LATER AFTERNOON AND EVENING HOURS. WILL USE THIS MODEL FOR THE TEMPORAL AND SPATIAL RAINFALL CHANCES TODAY. WILL HAVE THE GREATEST PUSH INLAND OVER THE NORTHERN ZONES...WITH A SLOWER INLAND PROPAGATION DOWN TOWARD LEE/CHARLOTTE COUNTIES IN CLOSER PROXIMITY TO THE RIDGE AXIS. THE HIGHEST COVERAGE OF STORMS TODAY WILL LIKELY BE DURING THE LATE AFTERNOON/EARLY EVENING OVER THE SOUTH-CENTRAL ZONES OF POLK/HIGHLANDS/HARDEE/DESOTO COUNTIES. AWAY FROM THE STORMS...TYPICAL SUMMER CONDITIONS ARE EXPECTED WITH PARTLY SUNNY SKIES AND TEMPERATURES CLIMBING TO WITHIN A COUPLE DEGREES OF 90. TONIGHT...CONVECTION LIKELY LINGERS INTO THE LATE EVENING HOURS ACROSS EASTERN POLK/HIGHLANDS COUNTIES...WHILE THE REMAINDER OF THE FORECAST AREA SEE DRIER CONDITIONS. AFTER MIDNIGHT...WOULD EXPECT MOST DRY CONDITIONS FOR ALL INLAND ZONES...ALTHOUGH A FEW LATE NIGHT SHOWERS ARE CLIMO FAVORED WITHIN THE SOUTHWEST FLOW OFF THE GULF OF MEXICO AT THE IMMEDIATE COAST. SATURDAY...THE FORECAST AREA WILL RESIDE BETWEEN THE SUBTROPICAL RIDGE AXIS TO OUR SOUTH...AND AN APPROACHING COLD FRONT DROPPING THROUGH THE SOUTHEAST CONUS TO OUR NORTH. THE ENTIRE REGION WILL SEE A DEFINED SOUTHWEST FLOW FOR THE DAYLIGHT HOURS OF SATURDAY...SUGGESTING THE SEA-BREEZE WILL REMAIN LESS DEFINED AND ALSO RAPIDLY PROGRESS INLAND TOWARD THE EASTERN PORTION OF THE STATE. THIS PATTERN FAVORS MOST OF THE AFTERNOON/EVENING STORMS TO OCCUR TO THE EAST OF OUR FORECAST ZONES. IN ADDITION TO THE PATTERN...THE NWP ENSEMBLES ARE ALL SUGGESTING SOME MUCH DRIER AIR ARRIVING IN THE MID-LEVELS FROM THE WEST DURING THE DAY. THE COMBINATION OF THESE TWO FACTORS SHOULD KEEP RAIN CHANCES BELOW CLIMO NORMS FOR JUST ABOUT ALL. RAIN CHANCES ACTUALLY LOOK QUITE LOW DURING THE AFTERNOON HOURS ALONG AREA BEACHES. HOWEVER...IF HEADING TO THE BEACHES...KEEP IN MIND THAT THE STEADY SOUTHWEST FLOW WILL BEGIN TO INCREASE THE RISK FOR STRONGER AND MORE FREQUENT RIP CURRENTS BY THE SECOND HALF OF THE DAY. THIS THREAT FOR ENHANCED RIP CURRENTS WILL CONTINUE THROUGH SUNDAY AS WELL. && .LONG TERM (SATURDAY NIGHT - THURSDAY)... BY THE START OF THE LONG TERM PERIOD...A DEEP UPPER LEVEL TROUGH WILL ALREADY BE IN PLACE OVER THE EASTERN CONUS...AND WILL HOLD IN PLACE THROUGH THE START OF THE WORK WEEK. AT THE SURFACE...A LOW PRESSURE SYSTEM CENTERED JUST SOUTH OF THE EASTERN GREAT LAKES WILL LIFT NORTHEAST INTO CANADA...DRAGGING A WEAK COLD FRONT INTO NORTHERN FLORIDA ON SUNDAY...WHERE IT WILL STALL OUT. THE SURFACE RIDGE AXIS WILL REMAIN SOUTH OF FLORIDA SUNDAY AND MONDAY...SETTING UP SOUTHWESTERLY FLOW ACROSS THE FORECAST AREA. ALTHOUGH SUNDAY WILL START OUT WITH A PATCH OF DRY AIR OVER MUCH OF THE FORECAST AREA...THE ENHANCED SOUTHEASTERLY FLOW SOUTH OF THE FRONTAL BOUNDARY WILL BRING DEEP MOISTURE BACK INTO THE REGION...ALLOWING FOR SCATTERED TO NUMEROUS THUNDERSTORMS SUNDAY AFTERNOON THROUGH MONDAY...WITH THE HIGHEST CHANCES FARTHER NORTH. TUESDAY THROUGH THURSDAY...THE UPPER LEVEL TROUGH WILL PULL AWAY FROM FLORIDA...ALLOWING THE COLD FRONT TO DEGRADE AND THE SURFACE RIDGE AXIS TO LIFT BACK NORTH TO AROUND THE INTERSTATE 4 CORRIDOR. THIS WILL BRING ABOUT A MORE TYPICAL SUMMERTIME PATTERN...WITH LIGHT GRADIENT FLOW AND SCATTERED THUNDERSTORMS...MOSTLY DURING THE AFTERNOON AND EARLY EVENING HOURS ALONG SEA BREEZE BOUNDARIES. && .AVIATION... VFR CONDITIONS ARE OBSERVED EARLY THIS MORNING ACROSS WEST-CENTRAL AND SOUTHWEST FLORIDA. OVERALL EXPECTING A TYPICAL SUMMER TYPE DAY FOR THE FORECAST TERMINALS WITH VFR CONDITIONS PERSISTING OUTSIDE OF SCATTERED MAINLY AFTERNOON/EVENING THUNDERSTORMS. SCATTERED STORMS WILL BE MOST LIKELY FOR KTPA/KPIE/KSRQ DURING THE LATE MORNING OR EARLY AFTERNOON...WITH STORMS THEN MOVING INLAND TOWARD KLAL. FURTHER SOUTH...A SCATTERING OF STORMS DURING THE AFTERNOON SHOULD PUSH EAST OF KPGD/KFMY/KRSW BY THE EVENING HOURS. && .MARINE... HIGH PRESSURE ACROSS THE EASTERN GULF OF MEXICO WILL SETTLE SOUTH THROUGH SATURDAY AS A COLD FRONT DROPS INTO THE SOUTHEASTERN STATES AND STALLS JUST NORTH OF THE AREA ON SUNDAY. WINDS AND SEAS WILL REMAIN LOW TONIGHT...HOWEVER THE GRADIENT WILL TIGHTEN THIS WEEKEND AHEAD OF THE FRONT RESULTING IN MORE STEADY SOUTHWEST FLOW AND HIGHER SEAS. THE WINDS AND SEAS WILL GENERALLY BE HIGHEST TO THE NORTH OF TARPON SPRINGS. WINDS NORTH OF TARPON SPRINGS MAY APPROACH CAUTIONARY LEVELS AT TIMES THIS WEEKEND. SHOWERS AND THUNDERSTORMS WILL ALSO BECOME MORE NUMEROUS THIS WEEKEND...MAINLY TO THE NORTH OF TARPON SPRINGS. && .FIRE WEATHER... NO SIGNIFICANT FIRE WEATHER CONCERNS ARE EXPECTED THROUGH THE UPCOMING WEEKEND AS RELATIVE HUMIDITY VALUES REMAIN ABOVE CRITICAL LEVELS. SHOWERS AND THUNDERSTORM WILL TAKE ON A TYPICAL PATTERN TODAY...BUT IT NOW APPEARS THAT DRIER AIR ARRIVING ALOFT WILL KEEP CONVECTIVE ACTIVITY BELOW NORMAL FOR SATURDAY. A FRONT WILL STALL JUST NORTH OF THE REGION SUNDAY INTO THE EARLY PORTION OF NEXT WEEK BRINGING HIGHER THAN NORMAL RAIN CHANCES TO AREAS NORTH OF THE INTERSTATE 4 CORRIDOR. FOG IMPACT...NO WIDESPREAD FOG IMPACTS ARE EXPECTED OVER THE NEXT SEVERAL DAYS. && .PRELIMINARY POINT TEMPS/POPS... TPA 91 79 91 79 / 40 10 20 10 FMY 92 76 93 77 / 40 20 20 10 GIF 93 75 93 75 / 60 40 30 10 SRQ 89 78 89 78 / 30 20 20 10 BKV 92 74 92 74 / 40 10 20 10 SPG 90 80 91 79 / 30 10 20 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WEATHER...14/MROCZKA LONG TERM/DECISION SUPPORT...18/FLEMING
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1152 PM CDT THU JUN 25 2015 .SHORT TERM /TONIGHT/... ISSUED AT 356 PM CDT THU JUN 25 2015 MAIN FORECAST CONCERN WAS FOCUSED ON WEAK SHORTWAVE CUTTING ACROSS NEBRASKA AND POTENTIALLY BRINGING SOME LOCALLY HEAVY RAIN TO FAR SOUTHERN IOWA TONIGHT. BOUNDARY LOOKS TO BE SET UP IN NORTHERN MISSOURI AND POSSIBLY SHIFT NORTH ENOUGH TO THE IOWA BORDER TONIGHT...BUT HAVE FAIRLY HIGH CONFIDENCE THAT IS THE FARTHEST EXTENT NORTH IT WILL REACH. DECENT MOISTURE CONVERGENCE ALONG THE MO/IA BORDER WITH STILL A GOOD ATMOSPHERE FOR EFFICIENT RAIN PRODUCERS. PRECIPITABLE WATER VALUES AROUND 1.5 INCHES AND WARM LAYER CLOUD DEPTHS IN THE 3500-3800 METER RANGE. FORWARD PROPAGATION CORFIDI VECTORS ORIENTED WEST TO EAST PROVIDING SOME TRAINING POTENTIAL ALONG THE FAR SOUTH. THE 25.19Z HRRR KEEPS MUCH OF THE HEAVY CONVECTION IN MISSOURI. HOWEVER...INCREASED POPS AND QPF OVER THE SOUTHERN TIER OF COUNTIES ALONG THE MISSOURI BORDER. OTHER CONCERN WAS ANOTHER WEAK SHORTWAVE TO PROVIDE SOME ELEVATED SHOWERS AND ISOLATED THUNDERSTORM OVER THE REMAINDER OF THE FORECAST AREA. QPF AMOUNTS SHOULD REMAIN UNDER QUARTER OF AN INCH AND THUS LOW IMPACT ON ANY ONGOING FLOODING .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 356 PM CDT THU JUN 25 2015 A MUCH...MUCH QUIETER 7 DAYS AHEAD IN THIS LONG TERM FCST PERIOD. WATER VAPOR IMAGERY PICKING UP ON HIGH PRESSURE COMING ONSHORE NEAR THE OREGON COASTLINE. THIS HIGH PRESSURE WILL HAVE SIGNIFICANT INFLUENCE ON OUR WEATHER MUCH OF NEXT WEEK. FRIDAY MORNING...MODELS PICKING UP ON A SHORTWAVE CONTINUING THROUGH SOUTHERN IA/NORTHERN MO. ISENTROPIC LIFT PERSISTING INTO 12Z AS THIS SYSTEM WILL LIKELY BE CLIPPING AT LEAST THE SOUTHERN TWO TO THREE TIERS OF COUNTIES IN IA. WITH YESTERDAY/S BOUNDARY LINGERING IN NORTHERN MO...A LOT OF THE MOISTURE FROM THURSDAY/S SYSTEM STILL AROUND. MODELS FOCUSING IN ON PWATS BTX 1.5 AND 1.75 INCHES...WHICH IS AROUND +1 TO +2 STD DEV. GOOD SUPPORT ALOFT AS MID-LEVEL Q-VECTOR CONV PRESENT TO INCREASE LIFT. 0-6KM MIXING RATIOS AROUND 7 G/KG WHICH IS DECENT ENOUGH. OVERALL SOUNDING PROFILE MUCH LESS SATURATED THAN MOST OF THIS WEEK...SO THIS SYSTEM WILL NOT BE THE MOST EFFICIENT IN RAIN PRODUCTION. FRI AFTERNOON TEMPS...850MB TEMPS AROUND 12C IN OUR EAST AND 14C IN OUR WEST...ABOUT -1 TO -2 STD DEV. THURSDAY/S 850 MB TEMPS WERE AROUND 14C NE TO 17C SW. AM EXPECTING SUNSHINE TO BREAK THROUGH...BUT NOT A LOT...SO HAVE KEPT TEMPS IN THE MID 70S. FRI AFTERNOON THUNDERSTORM POTENTIAL...0-6KM MUCAPE VALUES BTX 700 AND 1000 J/KG WHICH WHICH IS MINIMAL. 0-6KM BULK SHEAR NEAR 30KTS...ALSO MINIMAL. LCL HEIGHTS ABOVE 1000M. OVERALL SOUNDING PROFILE SUGGESTS ANYTHING THAT FORMS WOULD BE ELEVATED. THUS OVERALL...AM EXPECTING NIL SVR/TOR THREAT FRI PM AND THERE MAY BE A FEW SHORT LIVED NON-SEVERE STORMS PRIMARILY IN OUR NW. FOR SATURDAY NIGHT INTO SUNDAY EVENING...MODELS CONSISTENT WITH PROPAGATING AN AREA OF LOW PRESSURE FROM NW MINNESOTA INTO SE MINNESOTA. A WEAK COLD FRONT WILL BE ATTACHED TO THIS AND PUSHING THROUGH IA DURING THE DAYTIME. THE 12Z GFS IS A FAST OUTLIER WITH THIS SYSTEM AS IT PLACES THE BOUNDARY EAST OF OUR CWA BY 12-15Z SUN. HAVE MAINLY DISREGARDED THE GFS AND WENT WITH AN AVERAGE OF OTHER MODELS. PWATS JUMP FROM AROUND 1.25 TO 1.5 INCHES AND 0-6KM MUCAPE VALUES ARE AROUND 400 TO 600 J/KG. POSITION OF FRONT DURING PEAK DAYTIME HEATING IMPORTANT FOR SVR POTENTIAL. AS OF NOW...ALL SIGNS POINT TO THIS BOUNDARY BEING WELL EAST OF THE CWA BY DAYTIME HEATING. FOR MONDAY AND THE REST OF THIS LONG TERM FCST PERIOD...PERSISTENCE BECOMES A GOOD FORECAST THROUGH MID-WEEK. AN UPPER LEVEL TROUGH OVER THE NORTHEASTERN US AND AN UPPER LEVEL RIDGE OVER THE MOUNTAIN WEST WILL KEEP THE DMX CWA IN NORTHWESTERLY FLOW SEEMING INTO THE NEXT THU/FRI/SAT TIMEFRAME. A HUGE THERMAL RIDGE WILL BUILD OVER THE MOUNTAIN WEST COINCIDENT WITH THE UPPER LEVEL HIGH. THE RIDGE WILL STAY TO OUR WEST AND 850 MB TEMPS WILL BE IN THE DMX CWA WILL BE AROUND 15C TO OUR EAST AND 18C TO THE WEST. MODELS HINTING AT THERMAL RIDGE CRASHING DOWN INTO IA SOMETIME LATER IN THE WEEK...BRINGING A RETURN TO POP CHANCES TO THE AREA. && .AVIATION...26/06Z ISSUED AT 1152 PM CDT THU JUN 25 2015 AN UPPER LEVEL WAVE WILL PUSH INTO IA OVERNIGHT THROUGH FRIDAY MORNING LOWERING CIGS TO OCNL MVFR IN PRECIP. SCT SHRA/TSRA WILL OCCUR WITH THIS FEATURE AND WHILE MOST LOCATIONS WILL SEE SOMETHING...IT IS NOT EXPECTED TO BE WIDESPREAD. THE BEST LOCATIONS TO SEE STORMS WILL BE ACROSS FAR SOUTHERN IA...MAINLY AFFECTING KOTM. A LINE OF STORMS ACROSS MO/KS AND INTO NE WILL SHIFT A LITTLE NORTH AFFECTING FAR SRN IA. MVFR CIGS WILL BE MOST PREVALENT ACROSS THIS AREA. AS THE UPPER WAVE PASSES EAST PRECIP CHANCES WILL WANE AFT 18Z THOUGH SOME SPOTTY SHRA MAY PERSIST. ALL LOCATIONS WILL CLR AFT 21Z THROUGH THE REMAINDER OF THE TAF PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...KOTENBERG AVIATION...FAB
AREA FORECAST DISCUSSION
NWS JACKSON KY
141 AM EDT FRI JUN 26 2015 .UPDATE... ISSUED AT 141 AM EDT FRI JUN 26 2015 GIVEN ONGOING CONVECTION OVERNIGHT AND STORMS THURSDAY PRODUCING HEAVY RAINFALL HAVE OPTED TO ISSUE A FLASH FLOOD WATCH THROUGH THIS EVENING. DID UPDATE GRIDS AND GRIDS SENT TO NDFD. UPDATE ISSUED AT 1205 AM EDT FRI JUN 26 2015 QUICK UPDATE TO REFRESH THE T/TD GRIDS AND TO REMOVE THE SEVERE THUNDERSTORM WATCH. EXPECT SCATTERED STORMS TO CONTINUE THROUGHOUT THE NIGHT BUT THE SITUATION SEEMS TO HAVE TRANSITIONED TO MORE OF A HYDRO ISSUE...SO WILL HAVE TO KEEP AN EYE ON STORMS UPSTREAM. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS. UPDATE ISSUED AT 935 PM EDT THU JUN 25 2015 SHOWERS AND STORMS CONTINUE ACROSS NORTHEASTERN KENTUCKY THIS EVENING...WITH MOST OF THEM PRODUCING HEAVY RAINFALL AND FREQUENT LIGHTNING. STORMS EARLIER THIS AFTERNOON PRODUCED UP TO QUARTER SIZED HAIL...AND THIS REMAINS POSSIBLE TONIGHT AS WELL. SOME PATCHY FOG/MIST HAS ALREADY SET IN AT JKL DUE TO THE MULTIPLE ROUNDS OF RAIN THIS EVENING...SO HAVE ADDED IN PATCHY VALLEY FOG TO THE NORTHERN HALF OF THE CWA. OTHERWISE...ONLY MINOR ADJUSTMENTS WERE MADE TO THE T/TD GRIDS TO ALIGN THEM WITH OBS. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS. UPDATE ISSUED AT 640 PM EDT THU JUN 25 2015 STRONG TO SEVERE STORMS HAVE FINALLY STARTED TO DEVELOP ACROSS EASTERN KENTUCKY BUT REMAIN MOSTLY SCATTERED IN NATURE. EXPECT THE COVERAGE TO INCREASE THROUGHOUT THE EVENING HOURS SINCE THE CAP IS NOW BROKEN. DECIDED TO BUMP POPS UP TO INCLUDE AT LEAST A SLIGHT CHANCE POP ACROSS OUR SOUTHERN COUNTIES...AS WELL AS ADJUST T/TD GRIDS TO ALIGN THEM WITH RECENT OBS. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 359 PM EDT THU JUN 25 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE A STATIONARY BOUNDARY DRAPED ACROSS CENTRAL AND EASTERN KENTUCKY. CURRENT VISIBLE SHOT ACROSS THE AREA SHOWS SOME BREAKS IN THE CLOUD COVER ACROSS THE AREA. THIS HAS ALLOWED SOME INCREASED HEATING DESPITE THE CAP AND LACK OF INSTABILITY FROM THIS MORNINGS MCS. IF THE BREAKS AND INCREASED HEATING CONTINUES...SOME CONVECTION MAY BEGIN TO DEVELOP IN THE NEXT COUPLE OF HOURS. THE ISSUE HERE IS IF THE CAP AT 800MB IS BROKEN. THE HRRR HAS BEEN SLIGHTLY LESS STELLAR HINTING AT CONVECTION ALL AFTERNOON BUT TO NO AVAIL. SOME SHOWER ACTIVITY HAS DEVELOPED UPSTREAM IN SOUTHERN IN AND WESTERN KY SO WILL INTRODUCE SOME POPS INTO EASTERN KENTUCKY AFTER 21Z THIS AFTERNOON. HEADING INTO TONIGHT...THE NEXT CLUSTER OF STORMS DEVELOPS AND BEGINS TO TRACK SOUTHEAST INTO KY. THE FORMATION OF THIS AREA SHOULD BEGIN IN CENTRAL KY OR EVEN A BIT FURTHER WEST. IT IS WORTH MENTIONING THAT MODELS HAVE BEEN LESS THAN STELLAR PICKING OUT THIS DEVELOPMENT. THOUGH WITH TRENDS AND COLLABORATION WITH NEIGHBORING OFFICES...WILL BE INTRODUCING LIKELY POPS INTO EASTERN KENTUCKY SHORTLY AFTER 00Z BUT DEVELOPMENT AND A STARTING POINT FOR CONVECTIVE INITIATION IS A BIT OF A TOUGH CALL. TOMORROW...A STRONGER WAVE DIPS SOUTH INTO THE LOWER OH VALLEY CROSSING OVER THE RIDGE OUT WEST AND MAKES FOR AN INTERESTING SITUATION FOR KY ON FRIDAY EVENING AND FRIDAY NIGHT. WITH THIS...THE WARM FRONT WITH A STRONG SOUTHERLY SURGE PUSHES NORTH THROUGH THE AREA. AHEAD OF THIS SHOULD BE STRONG CONVECTION AND POSSIBLY SEVERE THUNDERSTORMS. EARLY MORNING CONVECTION MAY HINDER THIS A BIT BUT THE WARM AND MOIST AIR SURGING FROM THE SOUTH SHOULD MAKE FRIDAY EVENING AND INTO FRIDAY NIGHT QUITE INTERESTING. WILL MENTION THIS PERIOD IN THE HWO AS THIS WILL BEGIN AN ACTIVE PERIOD. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 359 PM EDT THU JUN 25 2015 MODELS APPEAR TO BE IN GOOD AGREEMENT WITH MID AND UPPER LEVEL FLOW THROUGH THE EXTENDED. WE FIND OURSELVES UNDER THE INFLUENCE OF A HIGH AMPLITUDE PATTERN WITH A MEAN EAST CONUS TROUGH AND WEST CONUS RIDGE. AS SUCH WE CAN EXPECT BELOW NORMAL TEMPERATURES THROUGH THE PERIOD AND IN GENERAL AN UNSETTLED WEATHER PATTERN. MODEL GUIDANCE IS IN GOOD AGREEMENT WITH A POSITIVELY TILTED TROUGH CUTTING OFF ACROSS THE GREAT LAKES REGION BY EARLY SATURDAY. THIS FEATURE WILL EVENTUALLY TRACK EAST...BECOMING NEGATIVELY TILTED AS IT MOVES INTO SOUTHERN NEW ENGLAND STATES SUNDAY. ADDITIONAL SHORTWAVE ENERGY DIGS OUT A REINFORCING TROUGH OVER OUR REGION BY MONDAY WHICH ONLY GRADUALLY LIFTS OUT TO THE NORTHEAST BY THE END OF THE FORECAST WINDOW. BY THEN THERE IS A TENDENCY FOR THE PATTERN TO BECOME LESS AMPLIFIED AND A BIT MORE ZONALLY ORIENTED AS WESTERN CONUS RIDGE SHIFTS OUT INTO THE PACIFIC AND ADDITIONAL SHORTWAVE ENERGY DROPS INTO THE UPPER MIDWEST. AT THE SURFACE...THE INITIAL TROUGH/CUT OFF LOW WILL AID IN DEVELOPING A SURFACE LOW ACROSS THE WESTERN OHIO VALLEY AT THE START OF THE PERIOD. THIS RELATIVELY DEEP AND WELL ORGANIZED SFC LOW WILL RIDE UP THE OHIO VALLEY OVER THE WEEKEND...WITH A TRAILING COLD FRONT ADVANCING ACROSS OUR AREA SATURDAY MORNING. ANOTHER FRONTAL SYSTEM WILL SWEEP THROUGH THE REGION AT THE START OF THE WEEK...LATE MONDAY INTO TUESDAY. ONCE AGAIN...THIS PATTERN WILL ENSURE BELOW NORMAL TEMPS THROUGH THE PERIOD WITH HIGHS IN THE MID 70S TO LOWER 80S AND LOWS MAINLY FALLING INTO THE 50S TO LOWER 60S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 141 AM EDT FRI JUN 26 2015 SHOWER AND THUNDERSTORMS CONTINUE TO DEVELOP TONIGHT SO HAVE OPTED TO KEEP AT LEAST VCTS IN THE TAFS OVERNIGHT. ALSO GIVEN ONGOING CONVECTION AND MORE OVERNIGHT MANY SITES WILL ALSO SEE POSSIBILITY OF FOG AND LOWER VIS DURING CONVECTION. IT DOES LOOK LIKE WE WILL SEE A LULL AS WE MOVE INTO THE DAY ON FRIDAY BEFORE MORE CONVECTION IS POSSIBLE ONCE AGAIN IN THE AFTERNOON. WINDS WILL REMAIN LIGHT...EXCEPT UNDER STORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...DJ SHORT TERM...SHALLENBERGER LONG TERM...RAY AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
1204 AM EDT FRI JUN 26 2015 .UPDATE... ISSUED AT 1205 AM EDT FRI JUN 26 2015 QUICK UPDATE TO REFRESH THE T/TD GRIDS AND TO REMOVE THE SEVERE THUNDERSTORM WATCH. EXPECT SCATTERED STORMS TO CONTINUE THROUGHOUT THE NIGHT BUT THE SITUATION SEEMS TO HAVE TRANSITIONED TO MORE OF A HYDRO ISSUE...SO WILL HAVE TO KEEP AN EYE ON STORMS UPSTREAM. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS. UPDATE ISSUED AT 935 PM EDT THU JUN 25 2015 SHOWERS AND STORMS CONTINUE ACROSS NORTHEASTERN KENTUCKY THIS EVENING...WITH MOST OF THEM PRODUCING HEAVY RAINFALL AND FREQUENT LIGHTNING. STORMS EARLIER THIS AFTERNOON PRODUCED UP TO QUARTER SIZED HAIL...AND THIS REMAINS POSSIBLE TONIGHT AS WELL. SOME PATCHY FOG/MIST HAS ALREADY SET IN AT JKL DUE TO THE MULTIPLE ROUNDS OF RAIN THIS EVENING...SO HAVE ADDED IN PATCHY VALLEY FOG TO THE NORTHERN HALF OF THE CWA. OTHERWISE...ONLY MINOR ADJUSTMENTS WERE MADE TO THE T/TD GRIDS TO ALIGN THEM WITH OBS. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS. UPDATE ISSUED AT 640 PM EDT THU JUN 25 2015 STRONG TO SEVERE STORMS HAVE FINALLY STARTED TO DEVELOP ACROSS EASTERN KENTUCKY BUT REMAIN MOSTLY SCATTERED IN NATURE. EXPECT THE COVERAGE TO INCREASE THROUGHOUT THE EVENING HOURS SINCE THE CAP IS NOW BROKEN. DECIDED TO BUMP POPS UP TO INCLUDE AT LEAST A SLIGHT CHANCE POP ACROSS OUR SOUTHERN COUNTIES...AS WELL AS ADJUST T/TD GRIDS TO ALIGN THEM WITH RECENT OBS. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 359 PM EDT THU JUN 25 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE A STATIONARY BOUNDARY DRAPED ACROSS CENTRAL AND EASTERN KENTUCKY. CURRENT VISIBLE SHOT ACROSS THE AREA SHOWS SOME BREAKS IN THE CLOUD COVER ACROSS THE AREA. THIS HAS ALLOWED SOME INCREASED HEATING DESPITE THE CAP AND LACK OF INSTABILITY FROM THIS MORNINGS MCS. IF THE BREAKS AND INCREASED HEATING CONTINUES...SOME CONVECTION MAY BEGIN TO DEVELOP IN THE NEXT COUPLE OF HOURS. THE ISSUE HERE IS IF THE CAP AT 800MB IS BROKEN. THE HRRR HAS BEEN SLIGHTLY LESS STELLAR HINTING AT CONVECTION ALL AFTERNOON BUT TO NO AVAIL. SOME SHOWER ACTIVITY HAS DEVELOPED UPSTREAM IN SOUTHERN IN AND WESTERN KY SO WILL INTRODUCE SOME POPS INTO EASTERN KENTUCKY AFTER 21Z THIS AFTERNOON. HEADING INTO TONIGHT...THE NEXT CLUSTER OF STORMS DEVELOPS AND BEGINS TO TRACK SOUTHEAST INTO KY. THE FORMATION OF THIS AREA SHOULD BEGIN IN CENTRAL KY OR EVEN A BIT FURTHER WEST. IT IS WORTH MENTIONING THAT MODELS HAVE BEEN LESS THAN STELLAR PICKING OUT THIS DEVELOPMENT. THOUGH WITH TRENDS AND COLLABORATION WITH NEIGHBORING OFFICES...WILL BE INTRODUCING LIKELY POPS INTO EASTERN KENTUCKY SHORTLY AFTER 00Z BUT DEVELOPMENT AND A STARTING POINT FOR CONVECTIVE INITIATION IS A BIT OF A TOUGH CALL. TOMORROW...A STRONGER WAVE DIPS SOUTH INTO THE LOWER OH VALLEY CROSSING OVER THE RIDGE OUT WEST AND MAKES FOR AN INTERESTING SITUATION FOR KY ON FRIDAY EVENING AND FRIDAY NIGHT. WITH THIS...THE WARM FRONT WITH A STRONG SOUTHERLY SURGE PUSHES NORTH THROUGH THE AREA. AHEAD OF THIS SHOULD BE STRONG CONVECTION AND POSSIBLY SEVERE THUNDERSTORMS. EARLY MORNING CONVECTION MAY HINDER THIS A BIT BUT THE WARM AND MOIST AIR SURGING FROM THE SOUTH SHOULD MAKE FRIDAY EVENING AND INTO FRIDAY NIGHT QUITE INTERESTING. WILL MENTION THIS PERIOD IN THE HWO AS THIS WILL BEGIN AN ACTIVE PERIOD. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 359 PM EDT THU JUN 25 2015 MODELS APPEAR TO BE IN GOOD AGREEMENT WITH MID AND UPPER LEVEL FLOW THROUGH THE EXTENDED. WE FIND OURSELVES UNDER THE INFLUENCE OF A HIGH AMPLITUDE PATTERN WITH A MEAN EAST CONUS TROUGH AND WEST CONUS RIDGE. AS SUCH WE CAN EXPECT BELOW NORMAL TEMPERATURES THROUGH THE PERIOD AND IN GENERAL AN UNSETTLED WEATHER PATTERN. MODEL GUIDANCE IS IN GOOD AGREEMENT WITH A POSITIVELY TILTED TROUGH CUTTING OFF ACROSS THE GREAT LAKES REGION BY EARLY SATURDAY. THIS FEATURE WILL EVENTUALLY TRACK EAST...BECOMING NEGATIVELY TILTED AS IT MOVES INTO SOUTHERN NEW ENGLAND STATES SUNDAY. ADDITIONAL SHORTWAVE ENERGY DIGS OUT A REINFORCING TROUGH OVER OUR REGION BY MONDAY WHICH ONLY GRADUALLY LIFTS OUT TO THE NORTHEAST BY THE END OF THE FORECAST WINDOW. BY THEN THERE IS A TENDENCY FOR THE PATTERN TO BECOME LESS AMPLIFIED AND A BIT MORE ZONALLY ORIENTED AS WESTERN CONUS RIDGE SHIFTS OUT INTO THE PACIFIC AND ADDITIONAL SHORTWAVE ENERGY DROPS INTO THE UPPER MIDWEST. AT THE SURFACE...THE INITIAL TROUGH/CUT OFF LOW WILL AID IN DEVELOPING A SURFACE LOW ACROSS THE WESTERN OHIO VALLEY AT THE START OF THE PERIOD. THIS RELATIVELY DEEP AND WELL ORGANIZED SFC LOW WILL RIDE UP THE OHIO VALLEY OVER THE WEEKEND...WITH A TRAILING COLD FRONT ADVANCING ACROSS OUR AREA SATURDAY MORNING. ANOTHER FRONTAL SYSTEM WILL SWEEP THROUGH THE REGION AT THE START OF THE WEEK...LATE MONDAY INTO TUESDAY. ONCE AGAIN...THIS PATTERN WILL ENSURE BELOW NORMAL TEMPS THROUGH THE PERIOD WITH HIGHS IN THE MID 70S TO LOWER 80S AND LOWS MAINLY FALLING INTO THE 50S TO LOWER 60S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 804 PM EDT THU JUN 25 2015 SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER THE PAST COUPLE OF HOURS...MAINLY IN AND AROUND THE JKL...SJS...AND SME TAF SITES. EXPECT THESE STORMS TO GRADUALLY WEAKEN WITH THE LOSS OF DAYTIME HEATING. BUT ANTICIPATE CIGS/VIS TO LOWER OVERNIGHT TONIGHT DUE TO LEFTOVER SHOWERS AND FOG DEVELOPMENT...WITH ALTERNATE MIN VIS POSSIBLE AT THE SJS...SME AND LOZ TAF SITES AND MVFR VIS AT THE JKL AND SYM TAF SITES. A LULL IN PRECIP DURING THE MORNING HOURS WILL ALLOW FOR VFR CONDITIONS FOR A TIME ON FRIDAY...BEFORE AFTERNOON THUNDERSTORM ACTIVITY DEVELOPS ONCE AGAIN. WINDS WILL REMAIN GENERALLY LIGHT THROUGH THE PERIOD OUTSIDE OF STORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JVM SHORT TERM...SHALLENBERGER LONG TERM...RAY/DJ AVIATION...JVM/HAL
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1205 AM CDT FRI JUN 26 2015 .AVIATION... FAIR AND VFR WITH SFC WINDS LIGHT S AND CLIMB WINDS SE- SW 10-20KTS...VEERING TO NW FLOW BY 12KFT. THERE MAYBE A SITE OR TWO WITH DAYBREAK BR. EXPECTING ANOTHER ROUND OF DIURNAL HEATING CONVECTION FOR FRI AFTN. W/ A TWIST AS A COLD FRONT EDGES INTO PLAY FOR THE OVERNIGHT AND MUCH OF SAT. SCT/NUMEROUS STORMS EXPECTED TO BECOME NOCTURNAL. GUSTY WINDS AND TURBULENCE NEAR DOWNPOURS/TOWERS WITH BETTER WX BY SUN WITH WEAK FROPA. /24/ && .PREV DISCUSSION... /ISSUED 927 PM CDT THU JUN 25 2015/ DISCUSSION... OUTFLOW BOUNDARY HAS PUSHED INTO NORTHEAST TEXAS LATE THIS EVENING BUT CONVECTION HAS NOT BEEN ABLE TO SUSTAIN ITSELF THIS EVENING LIKE THE PREVIOUS TWO EVENINGS. LATEST HRRR IN GOOD AGREEMENT WITH THIS ASSESSMENT SO IT SHOULD BE SAFE TO REMOVE POPS FROM THE FORECAST FOR THE REMAINDER OF THE EVENING. CONCERNING TEMPS... HAVE LOWERED TEMPS A FEW DEGREES ACROSS N LA WHERE EARLIER RAINFALL ALREADY HAD 02Z TEMPS NEAR OR AT FCST MIN TEMPS. DID RAISE TEMPS A DEGREE OR TWO ACROSS NE TX WHERE THE RAINFALL DID NOT MAKE IT...FOLLOWING PERSISTENCE OVER THE LAST SEVERAL MORNINGS IN THIS LOCATION. WE ARE LEFT WITH AN EXPANSIVE CLOUD DEBRIS PATTERN ON IR IMAGERY IN THE WAKE OF THE CONVECTION SO BEEFED UP SKY CONDITIONS FOR THE NEXT 6 HOURS OR SO BUT THE CLOUD COVER SHOULD BEGIN TO THIN AFTER MIDNIGHT. OTHER DEWPOINT/WIND GRIDS CHANGES WERE MOSTLY COSMETIC. UPDATE OUT SHORTLY...13. && .PRELIMINARY POINT TEMPS/POPS... SHV 75 85 70 89 / 60 60 30 0 MLU 75 86 70 88 / 60 60 30 20 DEQ 70 86 66 87 / 60 30 10 0 TXK 72 86 68 88 / 60 40 10 0 ELD 73 84 68 88 / 60 50 20 0 TYR 75 88 70 89 / 50 50 20 0 GGG 75 86 70 88 / 50 50 20 0 LFK 75 89 71 90 / 40 60 40 30 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$ 24/14
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
326 AM CDT Fri Jun 26 2015 .SHORT TERM: (Tonight through Friday) Issued at 322 AM CDT Fri Jun 26 2015 Active elements of large MCS over western MO will continue to move south and southeast early this morning while the stratiform rain area will continue to move east. RAP and HRRR continue to support the solution that stratiform rain area with moderate to occasionally heavy rain will slowly move east across the CWA today. RAP as well as the GFS/NAM show strong 850-925 moisture convergence moving from west to east across the area with PWATS near 2 inches. Will maintain going flash flood watch given these parameters and the saturated soils. Both the GFS and NAM show low level moisture convergence shifting southeast of the CWA by 00Z with the upper trough shifting east of the CWA by 06Z. Think that that the current end time of the flash flood watch of 00Z still is okay because the heavy rain should have ended by then. Rain chances overnight should be just scattered showers over the southeast half of the CWA after midnight. Temperatures will be much cooler today behind the front with cloudy skies, cold air advection, and rain. Highs in most areas will only be in the 70s. Britt .LONG TERM: (Tonight through Thursday) Issued at 322 AM CDT Fri Jun 26 2015 (Saturday and Sunday) Dry weather is expect on Saturday as subsidence sets in behind the exiting trough. Then chances of showers and thunderstorms increases Sunday and Sunday night as a shortwave trough dives down embedded in the northwestly flow aloft. MUCAPES will be in the 1500-2000 J/kg range and deep layer shear will be in the 30-40kt range which may be sufficient to produce a few isolated severe storms. (Monday through Thursday) Amplified upper pattern will dominate next week with shortwave troughs moving through the area every other day. This will keep a chance of showers and thunderstorm in the forecast during the period with below normal temperatures. Britt && .AVIATION: (For the 00z TAFs through 00z Friday Evening) Issued at 640 PM CDT Thu Jun 25 2015 Complex of showers and thunderstorms will affect the metro TAF sites over the next few hours with heavy rain accompanied by IFR visbilities possible along with gusty northwest winds. KUIN is likely to stay just north of most activity while KCOU will also likely have a period of storms this evening. Still anticipating some break late this evening/early overnight period before an organized bout of showers/storms associated with an MCS moves roughly along I-70. MVFR ceilings and even visibilities are likely behind this system into Friday afternoon along with a wind shift to the northwest. Specifics for KSTL: Complex of showers and thunderstorms will affect the metro TAF sites over the next few hours with heavy rain accompanied by IFR visbilities possible along with gusty northwest winds. Still anticipating some break late this evening/early overnight period before an organized bout of showers/storms associated with an MCS moves roughly along I-70 and affect KSTL Friday morning. Lingering showers with embedded thunder likely into early Friday afternoon. MVFR ceilings and even visibilities are also likely behind this system into Friday afternoon along with a wind shift to the northwest. Gosselin && .LSX WATCHES/WARNINGS/ADVISORIES: MO...FLASH FLOOD WATCH through this evening FOR Audrain MO-Boone MO- Callaway MO-Cole MO-Franklin MO-Gasconade MO-Jefferson MO- Knox MO-Lewis MO-Lincoln MO-Marion MO-Moniteau MO-Monroe MO- Montgomery MO-Osage MO-Pike MO-Ralls MO-Shelby MO-St. Charles MO-St. Louis City MO-St. Louis MO-Ste. Genevieve MO- Warren MO. IL...FLASH FLOOD WATCH through this evening FOR Adams IL-Bond IL- Brown IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL-Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL- Pike IL-Randolph IL-St. Clair IL-Washington IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
337 AM CDT FRI JUN 26 2015 .SYNOPSIS... ISSUED AT 336 AM CDT FRI JUN 26 2015 AT 08Z...ISOLATED SHOWERS CONTINUE TO TRAIL TO THE WEST ACROSS NCTRL NEBR BUT HAVE SHOWN RECENT TRENDS OF SLOWLY DISSIPATING AS THEY DROP SOUTHWARD. MOST OF THE THUNDERSTORM ACTIVITY RESIDES ACROSS PARTS OF KS AND MO. UPSTREAM ACROSS THE WRN DAKOTAS...MT AND WYOMING SKIES ARE CLEAR IN MOST AREAS. TEMPERATURES IN WRN NEBR RANGE FROM 59 TO 64 DEGREES. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 336 AM CDT FRI JUN 26 2015 TODAY...THE H5 UPPER TROUGH AXIS AND ASSOCIATED VORT MAX AT 12Z TO BE LOCATED IN WRN IA. UPSTREAM...THERE WILL BE CHANNELIZED VORTICITY TODAY. WHILE THIS WOULD SEEM SUPPORTIVE OF AT LEAST ISOLATED SHOWERS ACROSS THE ERN HALF OF FA AS INDICATED BY THE HRRR AND RAP MODELS...LATEST NAM AND GFS ARE DRIER. A CROSS SECTION ACROSS EASTERN AREAS SHOWS SUFFICIENT MOISTURE AVBL EXCEPT THAT GENERAL SUBSIDENCE NOTED. CURRENT FCST IS DRY TODAY...ALTHOUGH ISOLATED SHOWERS WOULD BE POSSIBLE. CURRENT BAND OF SHOWERS EAST-WEST ACROSS CHERRY COUNTY TO HOLT COUNTY CONTINUES TO DIMINISH IN COVERAGE AND EXPECTED TO DISSIPATED BY 12Z. THERE IS HOWEVER INCREASING COVERAGE OF STRATUS ACROSS THE CENTRAL SANDHILLS INCLUDING THEDFORD ATTM. SATELLITE TRENDS SHOWS AREA IS DEVELOPING TO THE SOUTHWEST WITH MAINLY MID LEVEL CLOUDS COVERING NCTRL NEBR. ANY STRATUS SHOULD BEGIN TO SCATTER OUT AFTER 15Z WITH SCT TO BKN STRATOCUMULUS EXPECTED TODAY. HIGHS TODAY NEAR PREVIOUS FCST FROM 77 TO 81 DEGREES. WINDS STEADY NORTH TO NORTHEAST 5 TO 10 MPH. LOOKING SYNOPTICALLY ACROSS THE CONUS...THE UPPER RIDGE WILL INTENSIFY ACROSS THE WRN CONUS AS THE UPPER TROUGH AMPLIFIES FROM THE GREAT LAKES INTO THE MID MISSISSIPPI VALLEY. WEAK SURFACE HIGH PRESSURE WILL BUILD SOUTH FROM THE NRN INTO THE CNTRL PLAINS. TONIGHT...UPPER FLOW WILL REMAIN NWRLY AS SURFACE HIGH PRESSURE RESIDES OVER THE CENTRAL PLAINS. SKIES EXPECTED TO BE MOSTLY CLEAR AND TEMPERATURES WILL BE COOLER FROM 55 TO 59 DEGREES. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 336 AM CDT FRI JUN 26 2015 THIS WEEKEND INTO THE FIRST OF NEXT WEEK WILL SEE A RIDGE DOMINATE THE WESTERN CONUS AS A TROUGH DIGS OVER THE GREAT LAKES REGION. NORTHWEST FLOW ACROSS THE HIGH PLAINS...HOWEVER THE RIDGE RIDING SHORT WAVES/STORMS ARE EXPECTED TO REMAIN TO THE NORTHEAST OF THE CWA. TEMPS ABOVE NORMAL /MORE SUMMER LIKE/ WITH HIGHS IN THE MID 80S TO LOWER 90S. MONDAY NIGHT INTO TUESDAY A STRONG DISTURBANCE WILL RIDE THE CREST OF THE RIDGE AND CAUSE A SFC LOW PRESSURE TO DEVELOP ON THE LEE SIDE OF THE ROCKIES. BY TUESDAY NIGHT THE LOW PRESSURE ALONG WITH A TRAILING WEAK COLD FRONT WILL SLIDE SOUTH ACROSS THE CENTRAL/HIGH PLAINS. MODELS STILL DIFFERING ON THE STRENGTH OF LOW PRESSURE AND HOW STRONG THE CAP WILL BE. THUS STORMS ARE POSSIBLE BUT THERE IS GREAT UNCERTAINTY. THE LATEST GFS HAS GONE DRIER WHILE THE ECMWF HAS INCREASED QPF ACROSS THE AREA. ONE AGREEMENT IS A SLIGHT BOOST OF TEMPS FOR TUESDAY AHEAD OF THE FRONT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1135 PM CDT THU JUN 25 2015 THE PROBABILITY OF THUNDERSTORMS WILL DECREASE THE REST OF TONIGHT. IN NORTHERN NEBRASKA...NORTH OF A BBW-TIF-MHN LINE...ANOTHER THUNDERSTORM SYSTEM WILL MOVE THROUGH. AFTER THE STORMS PASS...LOWER CEILINGS ARE LIKELY AS STRATUS FORMS IN THE MOIST STABLE AIR LEFT IN THE WAKE OF THE STORMS. THOUGH THERE IS A POSSIBILITY THAT CEILINGS BELOW 1000 FEET AGL WOULD FORM...THE MORE LIKELY SCENARIO IS CEILINGS WILL BE 1000-2000 FEET. THE NORTHERN STATIONS...NAMELY VTN...ANW AND ONL...HAVE A BETTER CHANCE OF HAVING CEILINGS AT OR BELOW 1000 FEET THAN ARE THE CENTRAL AND SOUTHWEST STATIONS...NAMELY BBW...LBF...OGA AND IML. && .HYDROLOGY... ISSUED AT 336 AM CDT FRI JUN 26 2015 CURRENT FLOOD WARNINGS FOR BRADY ON THE PLATTE RIVER SYSTEM AND LEWELLEN ON THE NORTH PLATTE RIVER SYSTEM REMAIN IN PLACE. RIVER LEVELS CONTINUE TO SLOWLY FALL. THE SOUTH PLATTE RIVER AT ROSCOE IS CURRENTLY JUST BELOW FLOOD STAGE AT 8.9 FEET AND WILL CONTINUE TO SLOWLY FALL THROUGH EARLY NEXT WEEK WITH THE FLOOD ADVISORY TO CONTINUE. THE SOUTH PLATTE RIVER AT NORTH PLATTE IS CURRENTLY NEAR 12.35 FEET AND WILL ALSO SLOWLY FALL THROUGH EARLY NEXT WEEK WITH THE FLOOD ADVISORY TO CONTINUE. RECENT RAINFALL FROM LAST EVENING DOES NOT APPEAR TO CAUSE CONCERN FOR ANY RISES...ONLY A SLIGHTLY LESS FALL IN STAGE IN THE NEAR TERM. RIVER LEVELS ALONG THE NORTH PLATTE RIVER UPSTREAM OF LAKE MCCONAUGHY ARE ELEVATED NEAR ACTION STAGE AT LISCO WHILE REMAINING ABOVE MINOR FLOOD STAGE AT LEWELLEN THROUGH EARLY NEXT WEEK. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...ROBERG SHORT TERM...ROBERG LONG TERM...MASEK AVIATION...SPRINGER HYDROLOGY...ROBERG
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
333 AM CDT FRI JUN 26 2015 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 333 AM CDT FRI JUN 26 2015 THE CHANCE FOR THUNDERSTORMS TODAY IS THE PRIMARY FORECAST CONCERN. THEN A GENERALLY DRY AND WARMER WEEKEND...WITH THE EXCEPTION OF A SMALL CHANCE FOR STORMS SUNDAY. NORTHWEST MID LEVEL FLOW ACROSS THE PLAINS WAS NOTED ON EVENING UPPER AIR CHARTS AND SHORT TERM MODEL OUTPUT. A COUPLE OF SHORTWAVES COULD BE IDENTIFIED WITHIN THE FLOW...AND RECENT RAP HEIGHT FORECASTS ALONG WITH WATER VAPOR IMAGERY SUGGESTED ONE WAVE WAS MOVING OUT OF SOUTHEAST NEBRASKA AS OF 3 AM...AND ANOTHER WAS APPROACHING NORTHEAST NEBRASKA FROM SOUTH DAKOTA. BOTH WAVES WERE TRIGGERING SCATTERED SHOWERS AND STORMS...HOWEVER THE STRONGEST WERE IN NORTHERN KANSAS WHERE LIFT WAS MAXIMIZED JUST NORTH OF FRONTAL BOUNDARY EXTENDING FROM KANSAS CITY TO WICHITA. GIVEN NORTHWEST FLOW ALOFT...SOUTHERN STORMS MOVING OUT OF OUR AREA WILL REMAIN THERE THIS MORNING. SHORTWAVE TO THE NORTH WILL GRADUALLY WORK SOUTHEAST TODAY...BUT ABSENCE OF SURFACE BOUNDARY/LOW LEVEL CONVERGENCE SUGGESTS ACTIVITY WILL REMAIN ISOLATED TO SCATTERED IN NATURE. IN FACT...MANY SHORT RANGE MESOSCALE MODELS INCLUDING HRRR AND RAP SUGGEST A DECREASE IN ACTIVITY THROUGH THE MORNING BEFORE AFTERNOON HEATING HELPS BUBBLE UP WIDELY SCATTERED AFTERNOON CONVECTION. SO WILL PLAY THE HIGHEST POPS IN NORTHEAST NEBRASKA THIS MORNING...THEN BROADBRUSH SMALL CHANCES THROUGH THE AFTERNOON ACROSS MUCH OF EASTERN NEBRASKA AND SOUTHWEST IOWA. COULD SEE SOME LINGERING SHOWERS/STORMS IN SOUTHEAST NEBRASKA OR SOUTHWEST IOWA DURING THE EARLY EVENING BEFORE SHORTWAVE PUSHES FARTHER AWAY AND WE LOSE AFTERNOON HEATING. OTHERWISE WE WILL SEE A TENDENCY TOWARD NORTHERLY LOW LEVEL FLOW TONIGHT AND SATURDAY AS HIGH PRESSURE SETTLES ACROSS THE REGION...AND BRINGS SLIGHTLY DRIER AIR INTO OUR AREA. SHOULD SEE PLENTY OF SUNSHINE SATURDAY WITH HIGHS IN THE LOWER 80S AFTER MORNING LOWS IN THE LOWER 60S. SOUTHERLY FLOW WILL RETURN SATURDAY NIGHT AS A SHORTWAVE DIVES INTO MINNESOTA THEN EVENTUALLY IOWA/WISCONSIN/ILLINOIS. SURFACE COLD FRONT WILL FOLLOW THIS WAVE AND SWEEP THROUGH EASTERN NEBRASKA AND SOUTHWEST IOWA ON SUNDAY. CONVECTION SATURDAY NIGHT SHOULD BE CONFINED TO AREAS TO OUR NORTHEAST WHERE STRONG WARM ADVECTION IS REALIZED JUST AHEAD OF MID LEVEL WAVE. ON SUNDAY...AXIS OF BEST LIFT NEAR SHORTWAVE AND SURFACE REFLECTION WILL STILL LIE WELL TO OUR EAST AND NORTHEAST IN MINNESOTA AND IOWA...BUT COULD SEE A FEW SHOWERS OR STORMS NEAR AND EAST OF THE NEBRASKA/IOWA BORDER AS COLD FRONT SWINGS SOUTHEAST. SHOULD SEE NICE WARMING ON SUNDAY AS SOUTHWEST FLOW AHEAD AND NORTHWEST FLOW BEHIND FRONT WILL PROMOTE DECENT MIXING. HIGHS THEN SHOULD EASILY REACH THE MID AND UPPER 80S. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 333 AM CDT FRI JUN 26 2015 GENERAL MID LEVEL FLOW PATTERN CHANGES ONLY A LITTLE DURING THE WEEK. BROAD HIGH PRESSURE WILL REMAIN OVER THE SOUTHWESTERN STATES THROUGH THE PERIOD. MEANWHILE UPPER LOW IN THE EASTERN GREAT LAKES EARLY IN THE PERIOD WILL LIFT TO THE NORTHEAST...LEAVING BROAD TROUGH BEHIND OVER THE EASTERN HALF OF THE COUNTRY. IN BETWEEN THESE FEATURES...FLOW IN THE CENTRAL PLAINS WILL SHIFT FROM NEARLY NORTHERLY TO NORTHWESTERLY BY MID WEEK. SEVERAL IMPULSES RIDING OVER WESTERN RIDGE WILL ENTER THE PLAINS...BRINGING OFF AND ON THUNDERSTORM CHANCES TO OUR REGION. GFS AND ECMWF ARE IN FAIRLY GOOD AGREEMENT WITH THIS OVERALL PATTERN CHANGE...BUT DIFFER ON TIMING OF PRECIPITATION-PRODUCING SHORTWAVES. HOWEVER BOTH MODELS ARE RELATIVELY SIMILAR IN DROPPING A MORE SIGNIFICANT SHORTWAVE INTO THE PLAINS ON TUESDAY...INCREASING THUNDERSTORM CHANCES IN EASTERN NEBRASKA AND WESTERN IOWA TUESDAY NIGHT AS ATTENDANT SURFACE LOW AND FRONTAL SYSTEM MOVE THROUGH THE REGION. WILL HAVE THE HIGHEST PRECIP CHANCES AT THIS TIME...THOUGH STILL ONLY IN THE CHANCE CATEGORY AS MOISTURE RETURN AFTER SUNDAY COLD FRONT WILL BE SLOW TO OCCUR. SHOULD SEE MINIMAL RAIN CHANCES BEHIND THIS SYSTEM ON WEDNESDAY AND THURSDAY...BUT GIVEN UNCERTAINTY IN SMALL-SCALE MID LEVEL FEATURES...CAN NOT RULE OUT A STRAY STORM OR TWO. OTHERWISE EXPECT TEMPERATURES TO AVERAGE 60S AND 80S FOR LOWS AND HIGHS THROUGH THE PERIOD. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1200 AM CDT FRI JUN 26 2015 SHORTWAVE STILL MOVING THROUGH TONIGHT AND FRIDAY WILL RESULT IN SPOTTY SHOWERS AND A FEW THUNDERSTORMS. MAINLY HAVE VFR CIGS WITH SOME PERIODS OF SHOWERS THROUGH 18Z. DUE TO THE SPOTTY NATURE OF THE THUNDERSTORM WILL HAVE TO MONITOR AND ADD IF NEEDED FOR THE THUNDER THREAT. SOME PATCHY MVFR VSBYS MAY TRY TO DEVELOP BY MORNING. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...DERGAN LONG TERM...DERGAN AVIATION...ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS ELKO NV
230 AM PDT FRI JUN 26 2015 .SYNOPSIS...HIGH PRESSURE WILL BUILD OVER THE BATTLE BORN STATE RESULTING IN TRIPLE DIGIT TEMPERATURES. EXPECT THE HEAT WAVE TO PERSIST THROUGH MONDAY. && .SHORT TERM...TODAY THROUGH SATURDAY. LOTS OF RIDGING THIS FORECAST PERIOD...MEANWHILE THE HRRR AND GFS ARE DRY AS A BONE...WITH THE RMOP IN UBER CONFIDENT TERRITORY. THE MEAN MAX TEMP FOR THE ELKO AIRPORT ON JUNE 26TH IS 85F...AND IS 87F FOR WINNEMUCCA... WENT FOR A HIGH OF 99F AND 101F RESPECTIVELY. FOR JUNE 27TH THE MEAN MAX TEMP FOR THE ELKO AIRPORT IS 85F...AND IS 88F FOR WINNEMUCCA... WENT FOR A HIGH OF 101F AND 104F RESPECTIVELY. ALL EYES WILL BE ON THE ASOS TO SEE IF THE RECORD MAXIMUM TEMPERATURES GET SHATTERED. .LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY. HUGE RIDGE IN PLACE THROUGH THE PERIOD MAKES IT LOOK LIKE THE DOGS DAYS WHEN IT`S BARELY THE END OF SPRING. HIGH TEMPS IN THE TRIPLE DIGITS OR NEAR THEM FOR EVERYWHERE. SOME PLACES WILL CERTAINLY SET DAILY RECORD HIGHS...SOME JUNE RECORDS. HOT ENOUGH TO PRODUCE LIMITED INSTABILITY...DRY ENOUGH THAT INITIALLY CB BASES WILL BE ABOVE 12000 FEET...SOME CLOSE TO 18000 FEET...FOR DRY THUNDERSTORMS. LATER A LOW FORMS OFFSHORE...FUNNELING MOISTURE INTO THE GREAT BASIN...BUT IT`S PATHETIC IN THE LOWER ATMOSPHERE AND...ALTHOUGH POPS RISE A FEW POINTS...QPF IS STILL BASEMENT BARGAIN. TOWARD THE END OF THE LONG TERM THE MODELS START TO QUARREL OVER HEIGHTS AND ORIENTATION...SO NO TWEAKS THEN...JUST STATUS QUO. BB && .AVIATION...VFR CONDITIONS ARE EXPECTED AT ALL TAF TERMINALS FOR THE ENSUING 24 HR PERIOD. ISOLATED DRY THUNDER POSSIBLE AT KTPH AND KELY FRIDAY AFTERNOON. NOTE: LIGHTNING SENSOR AT KWMC HAS BEEN TEMPORARILY TURNED OFF TO ELIMINATE FALSE REPORTS OF VCTS. REPAIRS WILL EFFECTED WHEN POSSIBLE. && .FIRE WEATHER...HOT AND DRY...HAINES OF 6 IMMINENT. WITH THE RIDGE IN PLACE EXPECTING A MAJOR HEAT WAVE. SOME MOISTURE WILL BE ABLE TO WORK ITS WAY AROUND THE BACK SIDE OF THE RIDGE SUPPORTING ISOLATED DRY THUNDERSTORMS. && .LKN WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM PDT SUNDAY FOR HUMBOLDT COUNTY-NORTHERN LANDER COUNTY AND NORTHERN EUREKA COUNTY. && $$ 97/98/98
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1152 PM MDT THU JUN 25 2015 .AVIATION... 06Z TAF CYCLE ISOLD THUNDERSTORMS WILL CONTINUE OVER SOUTH-CENTRAL NM OVERNIGHT...WITH SCATTERED ACTIVITY NEAR KCVS CONTINUING UNTIL AROUND 07Z. ANOTHER ROUND OF AFTERNOON AND EVENING CONVECTION EXPECTED FRIDAY BUT STORMS WILL BE MARKEDLY STRONGER DUE TO A STRONG BACKDOOR COLD FRONT DROPPING INTO ERN PLAINS DURING THE AFTERNOON AND THROUGH CENTRAL NM DURING THE AFTERNOON. STORM MOTION WILL BE TOWARD THE WEST OR SOUTHWEST AROUND 5KT. STRONG EAST CANYON WINDS LIKELY AT KABQ BY LATE AFTERNOON WITH MODERATE TO STRONG SE WINDS AT KSAF. SHOWERS AND STORMS WILL LINGER WELL AFTER SUNSET FRIDAY AS LARGE SCALE ATMOSPHERIC LIFT KEEPS STORMS GOING. 33 && .PREV DISCUSSION...317 PM MDT THU JUN 25 2015... .SYNOPSIS... AN ACTIVE PERIOD OF WEATHER WILL BE THE RULE THROUGH AT LEAST MONDAY. STORMS SHOULD EXPAND IN COVERAGE TONIGHT ACROSS THE EASTERN PLAINS...PERHAPS RESULTING IN AN EAST CANYON WIND IN THE RIO GRANDE VALLEY. STORM COVERAGE WILL INCREASE FURTHER ON FRIDAY THANKS TO A BACK DOOR COLD FRONT PUSHING THROUGH THE GAPS OF THE CENTRAL MOUNTAIN CHAIN. MOISTURE BEHIND THE FRONT WILL FUEL THUNDERSTORMS THROUGH THE WEEKEND INTO MONDAY. SLOW STORM MOTIONS AND HEAVY RAIN MAY LEAD TO FLASH FLOODING...ESPECIALLY ACROSS VULNERABLE DRAINAGES. A DOWNTREND IN STORM COVERAGE IS POSSIBLE TUESDAY AND WEDNESDAY...BUT STORM ACTIVITY WILL QUICKLY RAMP BACK UP AGAIN ON THURSDAY THANKS TO ANOTHER BACK DOOR FRONT AND MOISTURE SURGE. && .DISCUSSION... AS EXPECTED...ANOTHER CROP OF SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ACROSS THE HIGHER TERRAIN. AS THE UPPER HIGH REBUILDS OVER THE FOUR CORNERS...STEERING FLOW WILL CONTINUE TO TAKE STORMS TOWARD THE SOUTH. THUS FAR...STORMS HAVE BEEN MOVING JUST ENOUGH...AND HAVE BEEN PULSEY ENOUGH...TO NOT CAUSE TOO MANY WATER ISSUES. HI-RES MODELS SHOWING STORMS FIRING ALONG A BOUNDARY NEAR THE E NM/E CO BORDER THROUGH THE REMAINDER OF THE AFTN. APPEARS THAT STORMS MAY GET SOMEWHAT ORGANIZED INTO A CLUSTER...FORMING A COLD POOL...WITH STORMS PROPAGATING SOUTHWARD ACROSS THE PLAINS ALONG THE OUTFLOW BOUNDARY. THE QUESTION WILL BE HOW FAR SOUTH THE STORMS CAN HOLD TOGETHER BEFORE THE OUTFLOW BOUNDARY OUTRACES THE STORMS. HRRR KEEPS STORMS TOGETHER AS FAR SOUTH AS ROSWELL...BUT THE NAM SHOWS PRECIP FALLING APART SHORT OF THERE. NONETHELESS...HAVE INCREASED POPS ACROSS THE EASTERN PLAINS TONIGHT. THE SMALL DISTURBANCE NOTED ON WV SATELLITE IMAGERY NOSING INTO NE NM ATTM SHOULD AID IN STORM DEVELOPMENT AND MAINTENANCE. DEPENDING ON IF STORMS FIRE ALONG THE EAST SLOPES OF THE SANDIAS...AS THE HRRR SUGGESTS...COULD SEE A PRETTY STRONG...BUT SHORT-LIVED...EAST WIND INTO THE RGV. FRIDAY LOOKS TO BE MORE ACTIVE THAN TODAY...ESPECIALLY ACROSS THE PLAINS. THOUGH THE REMNANT BOUNDARY FROM TONIGHTS CONVECTION SHOULD BE SOMEWHERE ACROSS THE PLAINS TOMORROW...A BACK DOOR FRONT...LIKELY CONVECTIVELY AIDED... WILL SLIDE DOWN THE PLAINS EARLY FRIDAY. THUS...MULTIPLE ROUNDS OF STORMS WILL BE POSSIBLE...INITIALLY WITH THE FRONT...AND THEN AGAIN LATER IN THE DAY AFTER THE FRONT NUDGES UP TO THE CENTRAL MTN CHAIN...IGNITING STORMS...AND THOSE STORMS SHOULD TRAVEL S OR SE-WARD OUT INTO THE PLAINS ONCE AGAIN. MEANWHILE...THE FRONT WILL PUSH THROUGH THE CENTRAL MOUNTAIN CHAIN BY EARLY-MID AFTN...SPILLING LOW LEVEL MOISTURE WESTWARD. THUS...EXPECT ANOTHER ROUND OF STORMS ACROSS WESTERN NM AS WELL...PERHAPS WITH BETTER COVERAGE THAN TODAY. EAST CANYON WINDS SHOULD ONCE AGAIN BE PRETTY STRONG. WITH ABUNDANT MOISTURE /PWATS LIKELY ABOVE 1 INCH AREAWIDE/... NORTH TO SOUTH STEERING FLOW...AND LOW LEVEL S TO SELY FLOW THROUGH THE WEEKEND...AN ACTIVE PERIOD MIGHT BE AN UNDERSTATEMENT. STEERING FLOW WILL REMAIN WEAK...AND STORMS CONTAINING HEAVY RAIN IS A CERTAINTY. THIS SPELLS A RECIPE FOR FLASH FLOOD POTENTIAL...AND A FLASH FLOOD WATCH MAY BE NEEDED. MONDAY LOOKS TO BE MORE OF THE SAME...THOUGH A WEAK BOUNDARY WILL ALSO NOSE INTO NE NM AS WELL. ON TUESDAY AND WEDNESDAY... DRIER AIR LOOKS TO CIRCLE AROUND THE HIGH AND OVER NM. THOUGH THIS SHOULD LIMIT CONVECTIVE COVERAGE OVER THE FRI-SUN PERIOD...THERE WILL STILL BE ENOUGH MOISTURE AROUND FOR THE HIGH TERRAIN TO SEE SOME ACTION. ACTIVITY RAMPS BACK UP ON THURSDAY THANKS TO ANOTHER BACK DOOR FRONT REPLENISHING MOISTURE ACROSS THE STATE. CURRENT INDICATIONS IS THAT THIS FRONT WILL ALSO PUSH THROUGH THE GAPS OF THE CENTRAL MTN CHAIN...SETTING THE STAGE FOR NUMEROUS SHRA/TSRA THURS...AND FRIDAY. ANOTHER FRONT...OR PERHAPS OUTFLOW BOUNDARY FROM CONVECTION MAY ARRIVE ON THE 4TH OF JULY. LOOKS LIKE MOTHER NATURE WILL PROVIDE HER OWN FIREWORKS AGAIN THIS YEAR. 34 && .FIRE WEATHER... NO REAL BIG CHANGES. A MORE SIGNIFICANT PUSH OF MOISTURE FROM NORTHEAST TO SOUTHWEST WILL OCCUR TONIGHT THROUGH FRIDAY NIGHT VIA A BACK DOOR COLD FRONT. THIS SURGE WILL KICK OFF A WET PHASE TO THE MONSOON PERIOD. AS FAR AS THE REST OF TODAY...HIT AND MISS STORMS CONTAINING WETTING RAIN WILL IMPACT MOST OF THE AREA THROUGH THIS EVENING. THE MAIN FOCUS AREA FOR WETTING RAIN WILL BE FOUND ACROSS EASTERN/CENTRAL AREAS. THUNDERSTORMS SHOULD BLEED INTO THE EARLY MORNING HOURS ON FRIDAY. EXPECT GOOD TO EXCELLENT HUMIDITY RECOVERIES. GUSTY OUTFLOW WIND WILL BE ASSOCIATED WITH SOME OF THE STORMS. THE LOWEST HUMIDITY WILL BE FOUND ACROSS THE FAR NORTHWEST. STORMS WILL TEND TO MOVE TOWARDS A SOUTHERLY DIRECTION AND GENERALLY BE SLOW MOVING. AS THE UPPER RIDGE SHIFTS FURTHER NORTHWEST OF THE STATE ON FRIDAY. THIS WILL ALLOW A VIGOROUS BACK DOOR COLD FRONT TO SWEEP UNDERNEATH AND REENERGIZE MOISTURE SUPPLIES WITHIN THE PERIPHERY OF THE UPPER HIGH. HUMIDITY VALUES WILL GO UP AND TEMPERATURES WILL LOWER. A FOCUS FOR WIDESPREAD WETTING RAIN WILL BE FOUND ALONG THIS FRONTAL PUSH. CENTRAL AND EASTERN AREAS SHOULD BE FAVORED FRIDAY/FRIDAY NIGHT AND THEN SHIFT WESTWARD ON SATURDAY. WETTING THUNDERSTORM COVERAGE SHOULD LOWER SLIGHTLY ON SUNDAY BUT STILL BE PRETTY WIDESPREAD. HIGHER HUMIDITY AND COOLER TEMPERATURES WILL ALSO PREVAIL DURING THIS PERIOD. OUTFLOW WIND GUSTS WILL BE AROUND BUT NOT AS STRONG COMPARED TO A DRIER ATMOSPHERIC ENVIRONMENT. RESIDUAL IMPACTS OF THE MOISTURE TRAPPED WITHIN THE UPPER HIGH WILL CONTINUE EARLY NEXT WEEK. ANOTHER BACK DOOR COLD FRONT IS POSSIBLE SUNDAY NIGHT. A GRADUAL DRYING TREND IS EXPECTED TUESDAY AND COULD POSSIBLY TREND INTO WEDNESDAY. BY LATE WEEK ANOTHER BACK DOOR COLD FRONT SHOULD REPLENISH THE MOISTURE LOST EARLIER IN THE WAY AND INCREASE WETTING THUNDERSTORM COVERAGE. OVERALL VENTILATION WILL BE THE LOWEST DURING THE WEEKEND DUE TO REDUCED MIXING HEIGHTS...PLENTY OF CLOUD COVER AND LOWER TRANSPORT WINDS. 50 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 99
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1157 PM CDT THU JUN 25 2015 .UPDATE... ISSUED AT 1157 PM CDT THU JUN 25 2015 LATEST LOCAL RADAR SHOWS AREAL COVERAGE OF SHOWERS SOUTHWEST AND FAR SOUTH CENTRAL DIMINISHING. A RENEWED AREA OF SHOWERS DEVELOPING OVER WELLS COUNTY MAY CONTINUE FOR THE NEXT COUPLE OF HOURS PER LATEST HRRR AS THIS AREA SLIDES SOUTH. HAVE MENTIONED ISOLATED SHOWERS NORTHERN JAMES RIVER VALLEY. ONLY ADDITION OF WEATHER TO THE OVERNIGHT PERIOD WAS PATCHY FOG WEST AND PORTIONS OF CENTRAL NORTH DAKOTA PER HRRR MODEL. THIS SEEMS REASONABLE GIVEN THE SHOWERS EARLIER TODAY AND TEMPERATURE/DEWPOINT SPREADS CLOSING UP ON EACH OTHER. WILL LET THE FLASH FLOOD WARNING THAT WAS ISSUED EARLIER THIS EVENING FOR SOUTHWESTERN WILLIAMS AND NORTHWESTERN MCKENZIE COUNTIES TO EXPIRE AT 1215 AM CDT FRIDAY. STATE RADIO TELLS US TRAFFIC WAS MOVING NORMALLY IN THIS AREA AND THE WATER HAS RECEDED. UPDATE ISSUED AT 944 PM CDT THU JUN 25 2015 WILL CONTINUE THE TREND OF SHOWERS/THUNDERSTORM CHANCES DECREASING AS WE APPROACH MIDNIGHT. DRY OVERNIGHT THROUGH FRIDAY MORNING...FOLLOWED BY ANOTHER ROUND OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. UPDATE ISSUED AT 710 PM CDT THU JUN 25 2015 ISOLATED STORMS CONTINUE TO MOVE SOUTHEAST THROUGH THE WESTERN AND CENTRAL PARTS OF THE FORECAST AREA...GENERALLY ALONG AND WEST OF THE MISSOURI RIVER. SOME WERE PRODUCING SMALL HAIL AND WINDS TO 45 MPH. MESOSCALE MODELS SHOW A DECREASE IN INSTABILITY OVER THE NEXT FEW HOURS. WILL EXPECT A WEAKENING OF STORMS...AND FOR THEM TO DISSIPATE BY 10 PM OR SO. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 400 PM CDT THU JUN 25 2015 THE FORECAST FOCUS TODAY IS ON THUNDERSTORMS. THUNDERSTORMS HAVE GREATLY INCREASED IN COVERAGE OVER THE PAST COUPLE HOURS...AND PRECIPITATION CHANCES HAVE ONCE AGAIN BEEN INCREASED. THE SOUTHWEST REMAINS THE MOST LIKELY AREA FOR SUSTAINED CONVECTION...BUT WATER VAPOR SATELLITE IMAGERY INDICATES A COMPLEX TRAIN OF MID LEVEL SHORTWAVES PARADING TOWARD THE DAKOTAS. SO...WHILE ANY ONE OF THESE WAVES HAS SUFFICIENT DYNAMICS TO RELEASE THE CONVECTIVE INSTABILITY IN PLACE...COVERAGE SHOULD DIMINISH AS DIURNAL DESTABILIZATION REDUCES THIS EVENING. THIS FORECAST IS SUPPORTED BY THE 12 UTC HIRES ARW/NMM AND THE LAST SEVERAL RUNS OF THE HRRR. FINALLY...THE HIRES AND GLOBAL MODEL SUITE IS DRY BETWEEN MIDNIGHT AND SUNRISE...SO PRECIPITATION CHANCES HAVE BEEN REMOVED FROM THE FORECAST. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 358 PM CDT THU JUN 25 2015 THE WAVE THAT BRINGS ISOLATED STORMS AGAIN FRIDAY MOVES OUT BY DAYBREAK SATURDAY ENDING THE STORM CHANCES. SATURDAY AND SUNDAY...EVEN MONDAY...WILL BE DRY...MOSTLY SUNNY...AND VERY WARM WITH HIGHS IN THE 80S...TOUCHING 90 LIKELY ON SATURDAY ACROSS THE SOUTH. WINDS THROUGH THE PERIOD WILL BE 15 MPH OR LESS...LIGHT FOR NORTH DAKOTA STANDARDS. STORM CHANCES RETURN FOR TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1157 PM CDT THU JUN 25 2015 MENTIONED VCFG AT KDIK/KISN/KBIS THROUGH 15Z FRIDAY. OTHERWISE VFR CIGS/VSBYS NEXT 24HR. A VCTS WAS ADDED TO KMOT/KBIS/KJMS AFTER 22Z FRIDAY THROUGH 02Z SATURDAY. ANY SHOWER OR THUNDERSTORM THAT DEVELOPS WILL BE ISOLATED. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KS SHORT TERM...SCHECK LONG TERM...JPM AVIATION...KS
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
321 AM EDT FRI JUN 26 2015 .SHORT TERM (TODAY AND TONIGHT)... CONVECTION OVER KY HAS NOT MADE MUCH SOUTHWARD PROGRESS IN THE PAST FEW HOURS. WITH THE MIDLEVEL FLOW GENERALLY FROM THE WEST...OUR SW VA COUNTIES WILL HAVE THE BEST CHANCES OF RAIN THIS MORNING. THE HRRR HAS NOT BEEN HANDLING THE SITUATION VERY WELL...AND IT IS PROBABLY TOO AGGRESSIVE TO BRING THE CONVECTION SE. THE NAM IS REALLY UNDERDONE WITH THE ONGOING ACTIVITY...AS WELL AS THE RAP. WILL HAVE CHANCE POPS JUST ACROSS THE NORTH THIS MORNING. WITH DAYTIME HEATING...WILL BRING POPS SOUTHWARD IN THE AFTERNOON. CAPE WILL BE ABUNDANT TODAY WITH MLCAPES IN THE NAM OVER 3000 J/KG...SO SEVERE STORMS (WIND/HAIL) WILL BE POSSIBLE. THE THREAT OF STORMS WILL CONTINUE OVERNIGHT AS LOW PRESSURE TRACKS EAST ACROSS THE OHIO VALLEY...STRENGTHENING THE LLJ AND PUSHING THE SURFACE COLD FRONT IN TO MIDDLE TN. RAIN CHANCES WILL RISE AFTER MIDNIGHT TO LIKELY AND CATEGORICAL AS FORCING INCREASES. FLOODING WILL BE A THREAT AS WELL WITH HIGH PW VALUES AND TRAINING CELLS EXPECTED IN THE UNIDIRECTIONAL FLOW ALOFT. MOST AREAS HAVE BEEN DRY THE PAST FEW DAYS AND CAN ABSORB QUITE A BIT OF RAIN...SO WILL NOT ISSUE A FLOOD WATCH AT THIS TIME. .LONG TERM (TOMORROW THROUGH FRIDAY)... TOMORROW MORNING STARTS WITH THE COLD FRONT KNOCKING ON THE DOOR OF OUR AREA. FRONT WILL USHER IN TWO THINGS THAT WE`VE BEEN MISSING OUT ON FOR MOST OF THE MONTH... RAIN AND BELOW NORMAL TEMPERATURES. LOOKS LIKE THE TIMING OF THE FRONT WILL LIMIT THE CHANCES FOR WIDESPREAD SEVERE WEATHER AS ENERGY WILL BE LIMITED BY COOLER TEMPERATURES. HOWEVER... CAN`T RULE OUT THE CHANCE FOR A FEW STORMS TO CONVERGE OR STRENGTHEN TO THE POINT OF SEVERE LEVELS. THEY WILL BE AIDED BY AN 850MB JET OVER THE AREA OF AROUND 30 - 40 KNOTS. CAN`T RULE OUT SEVERE SIZE HAIL, BUT THE BIGGEST THREAT WOULD BE DAMAGING WIND GUSTS WITH THESE STORMS. HIGH TEMPERATURES ON SATURDAY WILL BE ABOUT 10 DEGREES COOLER THAN THEY WILL BE ON FRIDAY, WITH MUCH OF THE AREA EXPECTED TO ONLY GET INTO THE LOWER 80`S. LOOKS LIKELY THAT WE WILL NOT EXPERIENCE ANY HIGH TEMPERATURES IN THE 90`S THROUGH THE REMAINDER OF THE FORECAST. RAIN CHANCES LOOK GOOD FOR MOST PLACES, WITH THE BEST CHANCES IN THE NORTH CLOSER TO THE LOW MOVING OFF INTO NEW ENGLAND. WE THEN DRY OUT BEHIND THE FRONT AS IT PUSHES MOISTURE SOUTH INTO THE GULF OF MEXICO. RAIN CHANCES THEN INCREASE AS A SERIES OF WEAKER SYSTEMS MOVE THROUGH THE AREA. CURRENTLY HAVE CONTINUOUS RAIN CHANCES STARTING MONDAY THROUGH THE END OF THE 7-DAY FORECAST. UNFORTUNATELY MODEL DIFFERENCES BECOME LARGER AS THEY STRUGGLE WITH WHERE THE SYSTEMS WILL TRACK AND HOW MUCH PRECIPITATION WILL OCCUR. BUT THEY ALL DO AGREE THAT WE WILL SEE SEVERAL SYSTEMS MOVE THROUGH THAT SHOULD CAUSE AN INCREASE IN RAIN CHANCES/CLOUD COVERAGE WHILE SEEING CONTINUOUSLY COOLER TEMPERATURES. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 94 72 85 63 / 50 70 80 20 KNOXVILLE MCGHEE TYSON AIRPORT, TN 92 71 82 61 / 40 70 80 20 OAK RIDGE, TN 91 70 81 62 / 50 80 80 20 TRI CITIES AIRPORT, TN 88 70 80 56 / 50 80 80 30 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DGS/ABM
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1139 PM CDT THU JUN 25 2015 .DISCUSSION... UPDATED FOR 06Z AVIATION DISCUSSION. && .PREV DISCUSSION... /ISSUED 948 PM CDT THU JUN 25 2015/ UPDATE... A WARM AND MUGGY EVENING ACROSS THE MIDSOUTH...WITH FAIR WEATHER PREVAILING NEAR THE CENTER OF OF A 592DM 500MB RIDGE. TO THE NORTH... AN MCS WAS RIDING THE PERIPHERY OF THE RIDGE ALONG THE I-70 CORRIDOR. THE 01Z HRRR MODEL APPEARED A LITTLE TOO QUICK IN GENERATING AND ACCELERATING A COLD POOL DIRECTLY SOUTH FROM THE CENTRAL MO MCS. REGARDLESS...OUTFLOW FROM THE CURRENT ACTIVITY ENTERING SOUTH CENTRAL MO WILL LIKELY ENTER NORTHEAST AR AND THE MO BOOTHEEL DURING THE EARLY OVERNIGHT. IT/S UNKNOWN IF THIS OUTFLOW WILL GENERATE NEW CONVECTION AT IT MOVES SOUTH UNDER THE MIDLEVEL RIDGE. MUCH WILL DEPEND ON IF THE COLD POOL CAN ORGANIZE AND ACCELERATE SOUTHWARD AT THE RATE THE HRRR SUGGESTS. FOR THE LATE EVENING UPDATE...HAVE INTRODUCED SLIGHT CHANCE POPS FROM NORTHEAST AR THROUGH NORTHWEST LATE TONIGHT. PWB && .PREV DISCUSSION... /ISSUED 624 PM CDT THU JUN 25 2015/ .DISCUSSION... UPDATED FOR 00Z AVIATION DISCUSSION. PREV DISCUSSION... /ISSUED 256 PM CDT THU JUN 25 2015/ DISCUSSION... SKIES REMAIN MOSTLY SUNNY OVER MUCH OF THE FORECAST AREA THIS AFTERNOON WITH TEMPERATURES IN THE LOW TO MID 90S. TEMPERATURES ARE ACTUALLY RUNNING A COUPLE OF DEGREES COOLER THAN YESTERDAY AND HEAT INDEX VALUE ARE ALSO NOT QUITE AS HIGH AS WELL. SOME LOCATIONS ALREADY HAVE HAD HEAT INDEX READINGS ABOVE 105 AND WITH A COUPLE MORE HOURS OF HEATING LEFT SOME OTHER AREAS MAY ALSO REACH ABOVE 105. WILL LET HEAT ADVISORY CONTINUE THROUGH 7 PM CDT. CURRENT RADAR SHOWS VERY LITTLE IF ANY THUNDERSTORM ACTIVITY OVER THE FORECAST AREA SO IT APPEARS THAT MOST AREAS SHOULD REMAIN DRY TONIGHT. CURRENTLY A NEARLY STATIONARY BOUNDARY EXTENDS ACROSS THE CENTRAL PLAINS THROUGH THE OHIO VALLEY AND INTO THE MID-ATLANTIC STATES. THIS FRONT WILL START TO MOVE SOUTH AS A COLD FRONT ON FRIDAY. THUNDERSTORMS ARE EXPECTED TO DEVELOP AHEAD OF THE FRONT AND SOME OF THESE THUNDERSTORMS SHOULD MOVE INTO THE FORECAST AREA. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL AND NORTHWEST TENNESSEE WITH DAMAGING WINDS AND LARGE HAIL AS THE MAIN THREATS. TEMPERATURES WILL BE A LITTLE COOLER WITH THE INCREASE IN CLOUDS AHEAD OF THE FRONT AS HIGHS WILL BE MAINLY IN THE LOWER 90S. HEAT INDEX VALUES WILL NOT BE AS HIGH AS THEY HAVE BEEN THE LAST COUPLE OF DAYS SO A HEAT ADVISORY WILL NOT BE NEEDED. THE COLD FRONT WILL CONTINUE TO MOVE SOUTH AND WILL REACH NORTHERN SECTIONS OF THE FORECAST AREA FRIDAY NIGHT SO THERE WILL BE A BETTER CHANCE OF THUNDERSTORMS. THE SLIGHT RISK OF SEVERE THUNDERSTORMS WILL CONTINUE OVER NORTHERN SECTIONS OF THE FORECAST AREA AS WELL. TEMPERATURES WILL NOT BE AS WARM AS THEY BEEN THE LAST FEW DAYS WITH LOWS SATURDAY MORNING IN THE UPPER 60S TO LOWER 70S. THE COLD FRONT WILL EXIT THE FORECAST AREA SATURDAY MORNING WITH THUNDERSTORMS ENDING OVER NORTH MISSISSIPPI. MUCH COOLER AND DRIER AIR WILL MOVE INTO THE REGION BEHIND THE FRONT WITH HIGHS ON SATURDAY ONLY IN THE LOW TO MID 80S. HIGH PRESSURE WILL BUILD INTO THE REGION SATURDAY NIGHT WITH LOWS SUNDAY MORNING MAINLY IN THE 60S. DRY WEATHER AND BELOW NORMAL TEMPERATURES WILL CONTINUE INTO SUNDAY. BY SUNDAY NIGHT...ANOTHER COLD FRONT WILL START TO MOVE INTO THE CENTRAL PLAINS AND THE MID MISSISSIPPI VALLEY. SOME ISOLATED THUNDERSTORMS MAY BE POSSIBLE OVER EXTREME NORTHWEST SECTIONS OF THE FORECAST AREA. BY MONDAY...THE COLD FRONT WILL CONTINUE TO MOVE SLOWLY SOUTH TOWARD THE FORECAST AREA. AS IT DOES THERE WILL BE A LITTLE BETTER CHANCE OF THUNDERSTORMS. TEMPERATURES WILL CONTINUE TO BE BELOW NORMAL WITH HIGHS IN THE MID 80S. THE COLD FRONT WILL START TO STALL OUT ALONG THE NORTHERN BORDER OF THE FORECAST AREA SO THERE WILL STILL BE SCATTERED THUNDERSTORMS FOR TUESDAY THROUGH NEXT THURSDAY. TEMPERATURES WILL CONTINUE TO BE BELOW NORMAL THROUGH THE PERIOD. ARS && .AVIATION... 06Z TAF CYCLE (26/06Z-27/06Z) VFR MOST OF THE PERIOD UNTIL CONVECTION DEVELOPS ALONG A PASSING COLD FRONT. NARROWED DOWN TIMING OF HEAVIER ACTIVITY...RESULTING IN EXPECTED IMPACTS DURING FEDEX NIGHT OPS AT MEM. IT IS POSSIBLE FOR ISOLATED EARLIER/AFTERNOON ACTIVITY AHEAD OF THE FRONT...BUT CONFIDENCE FOR NOW IS LEANING TOWARDS A VCSH REMARK. REMAINED CONSERVATIVE WITH STORM INDUCED WINDS...KNOWING THAT A FEW STORMS IN THE AREA COULD PRODUCE STRONGER GUSTS. CONVECTION WILL START TO IMPACT TUP AT THE VERY END OF THE PERIOD WHILE IT STARTS TAPERING OFF AT JBR. LIGHT SOUTHWEST GRADIENT WINDS WILL INCREASE TO 8 TO 12 KTS BY MID MORNING...WITH AFTERNOON GUSTS AT JBR AND MEM. JAB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS ALBANY NY
959 AM EDT FRI JUN 26 2015 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE REGION THIS AFTERNOON WITH ISOLATED SHOWERS MAINLY FROM THE MOHAWK VALLEY SOUTH AND EAST. THEREAFTER...HIGH PRESSURE WILL BUILD OVER THE REGION LATE THIS AFTERNOON INTO THIS EVENING...RESULTING IN A BRIEF PERIOD OF FAIR AND DRY WEATHER. AN INTENSIFYING STORM OVER THE OHIO VALLEY WILL APPROACH ON SATURDAY...BRINGING PERIODS OF RAIN AND COOL CONDITIONS FOR THIS FIRST FULL WEEKEND OF SUMMER. && .NEAR TERM /THROUGH TONIGHT/... AS OF 959 AM EDT...THIS UPDATE IS TO RETOOL THE POP TRENDS AND CLOUD COVERAGE ACROSS THE REGION. THE COLD FRONT HAS SLIPPED SOUTH OF THE REGION WITH THE MAIN FEATURE OF INTEREST THE UPPER LEVEL TROUGH AXIS MOVING TOWARDS THE ST LAWRENCE RIVER VALLEY PER THE LATEST HRRR/RAP40/NAM. PARTLY CLOUDY/MOSTLY CLEAR CONDITIONS WILL BECOME MOSTLY CLOUDY FROM THE CAPITAL REGION/MOHAWK VALLEY SOUTH WITH THE UPPER TROUGH PASSAGE THIS AFTERNOON. SOME ISOLD SHOWERS ARE POSSIBLE DUE TO THE CYCLONIC VORTICITY ADVECTION DUE TO THE SHORT-WAVE ROTATING AROUND THE UPPER LOW. SOME SCT SHOWERS ARE POSSIBLE OVER THE HIGHER TERRAIN. ANY RAINFALL AMOUNTS SHOULD BE LIGHT WITH A FEW HUNDREDTHS. THE LATEST HRRR INDICATES THE SHOWER SHOULD DIMINISH NORTH OF THE CAPITAL REGION/MOHAWK VALLEY IN THE EARLY PM. HIGHS MOSTLY IN THE MID TO UPPER 70S FOR VALLEY LOCATIONS WITH UPPER 60S TO LOWER 70S FOR THE HIGHER TERRAIN. INTO TONIGHT...SURFACE HIGH BUILDS AND CRESTS ACROSS THE REGION FOR A TRANQUIL PERIOD OF WEATHER. A LIGHT NORTHERLY WIND WILL SUBSIDE TO LIGHT AND VARIABLE UNDER PTCLOUDY-MOCLEAR SKIES. HOWEVER...THE METEOROLOGICAL EYES WILL BE WATCHING WHAT TRANSPIRES UPSTREAM AS NCEP MODEL SUITE AND INTERNATIONAL GUIDANCE ARE BECOMING MORE IN AGREEMENT WITH AN ANOMALOUS DIGGING/PHASING TROUGH ACROSS THE MID WEST WITH EXPANDING AREA OF CLOUDS AND RAIN/SHOWERS. CLOUD COVERAGE MAY APPROACHING OUR SOUTHERN MOST ZONES OVERNIGHT BUT IT WILL REMAIN DRY. OVERNIGHT LOWS MAINLY INTO THE 50S WITH SOME UPPER 40S ACROSS PORTIONS OF THE DACKS...BERKS...SOUTHERN GREENS. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... IMPRESSIVE STORM TO DEVELOP ACROSS THE OHIO VALLEY AND IMPACT OUR REGION THIS WEEKEND... THE PREVIOUS EXCELLENT AFD FOLLOWS WITH MINOR UPDATES PER THE 00Z GUIDANCE. SATURDAY...THE 26/00Z ECMWF SHOWS THE SFC WAVE MOVING A LITTLE SLOWER TOWARDS A MID LEVEL JET CONFLUENT REGION OVER E-OH AND W-PA BY MID MORNING. THE ISENTROPIC LIFT INCREASES QUICKLY ON THE 290-300K SFC BY THE LATE MORNING INTO THE AFTERNOON ESPECIALLY SOUTH AND WEST OF THE CAPITAL REGION. THE LOW-LEVEL BAROCLINIC LEAFLET STRENGTHENS BETWEEN THE RETREATING AND STRENGTHENING HIGH OFF THE NEW ENGLAND COAST /1022MB/ ...AND THE LOW PRESSURE SYSTEM MOVING TOWARDS LAKE ERIE AND WRN PA BY THE EARLY PM WITH SUB 1000MB EXPECTED. THE GFS/ECMWF ATTEMPT TO HAVE A SECONDARY LOW FORM OVER THE MID ATLANTIC REGION THROUGH THE AFTERNOON. OVER RUNNING RAINFALL AHEAD OF THE PRIMARY SFC CYCLONE...AND THE WARM FRONT SHOULD OVER SPREAD THE REGION BY THE EARLY EVENING. AN ANOMALOUS H850/925 E/SE LLJ INCREASES AHEAD OF THE SFC WAVE TO BETTER THAN 40KTS. THE LATEST GFS/ECMWF HAVE E/SE WINDS OF 45-55KTS OVER THE FCST AREA BY 8 PM SAT. PLENTY OF ATLANTIC MOISTURE ENTRAINMENT SHOULD BE ADVECTED INTO THE REGION FOR PERIODS OF MDT-HVY RAIN BY SAT EVENING. HIGHS WILL BE BELOW NORMAL WITH MID AND U60S COMMON IN THE LOWER ELEVATIONS AND M50S TO L60S OVER THE HIGHER TERRAIN ACROSS THE CATSKILLS. SATURDAY NIGHT...THIS WILL BE THE HIGHEST POTENTIAL IMPACT PERIOD...AND WILL CONTINUE WHAT THE PREVIOUS SHIFT HIGHLIGHTED IN THE SEGMENTED HWO. THE GEFS INDICATE ANOMALOUS LLJ WITH U-WIND ANOMALIES 3 TO 5 STANDARD DEVIATIONS GREATER THAN NORMAL /STRONG EASTERLIES/ AND STRONG V-WIND ANOMALIES /STRONG SOUTHERLIES/ 3 TO 5 STANDARD DEVIATIONS GREATER THAN NORMAL. HENCE...A SE LOW-LEVEL JET MAX WILL FOCUS PERIODS OF MODERATE TO HEAVY RAINFALL. THE E/SE FLOW WILL ENHANCE THE RAINFALL ALONG THE SPINE OF THE ERN DACKS...ERN CATSKILLS...SRN GREENS..BERKS...AND NORTHERN LITCHFIELD HILLS. PWATS LOOK TO BE 1 TO 2 STD DEVS ABOVE NORMAL...SLIGHTLY HIGHER SOUTH AND EAST OF THE CAPITAL DISTRICT WHERE UP TO 3 STD IS CURRENT PROGGED. THERE IS A SMALL WINDOW WHERE THE E/SE WINDS MAY GUST CLOSE TO WIND ADVISORY LEVELS OVER THE SRN GREENS IN SRN VT...NRN TACONICS...AND POSSIBLY THE NRN BERKS. IT WILL DEPEND ON HOW MUCH MOMENTUM CAN BE TRANSFERRED TO SFC THROUGH A STRONG INVERSION IN THE SOUNDINGS AND ITS OCCURRING NOCTURNALLY. WE WILL MENTION THE THREAT AND CONTINUE WHAT THE DAY SHIFT HAS IN THE HWO. IT IS HARD TO TELL HOW MUCH OF A THREAT THE RAIN WILL HAVE FOR FLOODING AT THIS TIME. 1 TO 3 INCHES LOOKS POSSIBLE SAT PM INTO SUNDAY MORNING BASED ON THE EC/WPC/CAN GGEM GUIDANCE...WITH THE MESOSCALE MODELS SHOWING SOME 3-4 INCH AMOUNTS IN THE ERN CATSKILLS...AND ERN DACKS. PER EXTENSIVE COLLABORATION FROM SURROUNDING WFOS...CONFIDENCE REMAINS LOW FOR A FLOOD WATCH AT THIS TIME...BUT WILL CONTINUE TO MONITOR AND MENTION IN THE HWO. ZONE FFG VALUES REMAIN HIGH IN THE 3/6-HR TIME FRAME. CATEGORICAL POPS WERE CONTINUED WITH RAIN...HVY AT TIMES...SATURDAY NIGHT. IN ADDITION...SHOWALTER VALUES ARE PROGGED EVEN LOWER WITH SUB ZERO VALUES ADVECTING INTO THE REGION TO WARRANT AN INCLUSION OF THUNDERSTORMS OVERNIGHT. LOWS WILL BE MAINLY IN THE 50S. SUNDAY...MODEL TRENDS NOW WANT TO ADVECT IN A DRY SLOT DURING THE DAY WHICH WILL REDUCE THE PRECIP COVERAGE AND INTENSITY ACROSS MOST OF THE REGION FOR A SMALL WINDOW OF TIME. QUESTION IS IF WE ARE ABLE TO SEE SOME INSOLATION TO ASSIST WITH DESTABILIZATION. WHILE THE MAIN THRUST OF ADVECTION WILL BE WELL TO OUR NORTH...THE VERTICALLY STACKED LOW ACROSS WESTERN NY WITH SECONDARY LOW POSSIBLY TRACKING NORTH...NARROW LINES OF CONVECTION COULD EVOLVE. WE WILL FOLLOW A BLENDED MOS VALUES WHICH REQUIRES A SLIGHT ADJUSTMENT UPWARD IN THE AFTERNOON HIGH TEMPS TO LOWER HALF OF THE 70S FOR VALLEY LOCATIONS AND 60S ELSEWHERE. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE LARGE VERTICALLY STACKED STORM SYSTEM IMPACTING THE REGION WILL FINALLY START TO MOVE AWAY ON SUNDAY NIGHT...AS BOTH THE SFC AND UPPER LEVEL LOWS MOVE FROM UPSTATE NY TOWARDS SOUTHERN QUEBEC AND NORTHERN NEW ENGLAND. AS A RESULT...CHANCES FOR RAIN SHOWERS WILL DECREASE THROUGH THE OVERNIGHT HOURS ON SUN NIGHT...ALTHOUGH WITH CYCLONIC FLOW STILL IN PLACE...A FEW LIGHT RAIN SHOWERS AND PLENTY OF CLOUDS REMAIN POSSIBLE. MIN TEMPS LOOK TO FALL INTO THE MID 50S FOR MOST PLACES. BY MONDAY...WEAK RIDGING ALOFT WILL POKE INTO THE REGION...ALLOWING FOR PARTIAL SUNSHINE. CANNOT TOTALLY RULE OUT A BRIEF SHOWER...ESP EARLY IN THE DAY...ACROSS THE ADIRONDACKS OR SRN GREENS...BUT MOST AREAS LOOK TO STAY DRY. MAX TEMPS SHOULD REACH INTO THE MIDDLE TO UPPER 70S FOR VALLEY AREAS...WITH 60S FOR THE HIGH TERRAIN. DRY WEATHER LOOKS TO CONTINUE INTO MONDAY NIGHT WITH LOWS IN THE 50S ONCE AGAIN. WITHIN THE FLOW AT 500 HPA...ANOTHER SHORTWAVE TROUGH WILL ROTATE TOWARDS THE REGION FROM THE GREAT LAKES. COMBINED WITH A MOIST SOUTHERLY FLOW AND DAYTIME HEATING...A FEW ROUNDS OF SHOWERS AND THUNDERSTORMS CAN BE EXPECTED FOR TUESDAY...ESP DURING THE AFTN AND EVENING. CAN/T RULE OUT A FEW STRONG STORMS...ALTHOUGH WILL ULTIMATELY DEPEND ON HOW MUCH INSTABILITY WILL BE IN PLACE. MAX TEMPS LOOK TO REACH CLOSE TO 80 IN MANY VALLEY AREAS. SHOWERS AND THUNDERSTORMS WILL WIND DOWN ON TUESDAY EVENING WITH THE LOSS OF DAYTIME HEATING AND AS THE BEST UPPER LEVEL FORCING SHIFT EASTWARD. HOWEVER...MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON WEDNESDAY WITH THE BROAD UPPER LEVEL TROUGH REMAINING OVER THE AREA AND ANOTHER SHORTWAVE ROTATING BY CLOSE TO THE REGION. TEMPS ONCE AGAIN LOOK TO REACH THE UPPER 70S TO NEAR 80. DRIER WEATHER LOOKS TO RETURN FOR THE LATE WEEK PERIOD...ALTHOUGH THIS WILL BE DETERMINED BY JUST WHEN THE FLOW AT 500 HPA CAN FLATTEN OUT. WILL CONTINUE SLIGHT TO LOW CHC POPS FOR THURSDAY DUE TO THE UNCERTAINTY...WITH TEMPS MAINLY IN THE UPPER 70S. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS WILL CONTINUE FOR ALL TAF SITES FOR TODAY INTO TONIGHT. A WEAK UPPER LEVEL DISTURBANCE IS PASSING BY TO THE NORTH OF THE REGION. THIS SYSTEM HAS ALLOWED FOR SOME VERY LIGHT RAIN SHOWERS OVERNIGHT. MOST OF THESE SHOWERS ARE DEPARTING OFF TO THE EAST...AND ASIDE FROM A BRIEF SHOWER/SPRINKLE OVER THE NEXT HOUR OR TWO...NO ADDIIONAL RAIN IS EXPECTED AT THE TERMINALS TODAY. ANY SHOWER EARLY THIS MORNING WILL BE VERY LIGHT AND HAVE LITTLE TO NO EFFECT ON VSBYS/CIGS. OTHERWISE...BKN MID LEVEL CLOUDS THIS MORNING WILL EVENTUALLY BECOME SCT FOR THIS AFTN. NORTHERLY WINDS WILL PICK UP TO 5-10 KTS FOR DURING THE DAY TODAY. WINDS WILL DECREASE THIS EVENING WITH THE LOSS OF DAYTIME HEATING/MIXING. HIGH CLOUDS WILL INCREASE THROUGH THE EVENING HOURS...AND BECOME SCT-BKN FOR ALL SITES BY THE LATE EVENING HOURS...AS A STORM SYSTEM STARTS TO APPROACH FROM THE OHIO VALLEY. ANY RAIN LOOKS TO HOLD OFF UNTIL DURING THE DAY SATURDAY. OUTLOOK... SATURDAY THROUGH SUNDAY: HIGH OPERATIONAL IMPACT. RA LIKELY. SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. && .FIRE WEATHER... MINIMAL TO LOW FIRE WEATHER RELATED CONCERNS THROUGH THE WEEKEND AS ISOLATED TO SCATTERED SHOWERS PERSIST INTO THIS MORNING. A BRIEF PERIOD OF DRY WEATHER IS EXPECTED LATER THIS AFTERNOON INTO EARLY SATURDAY MORNING BEFORE A WIDESPREAD...SOAKING RAINFALL OCCURS FOR THE MAJORITY OF THE REGION SATURDAY AFTERNOON INTO SUNDAY MORNING. THE RH VALUES WILL LOWER TO 40 TO 60 PERCENT TODAY WITH THE LOWER VALUES NORTH OF THE MOHAWK RIVER VALLEY. THE RH VALUES WILL HAVE AN EXCELLENT RECOVERY SATURDAY MORNING IN THE 75 TO 100 PERCENT RANGE AND REMAIN HIGH THROUGH THE DAY AS WET WEATHER SPREADS ACROSS THE ENTIRE REGION. THE WINDS WILL LIGHT FROM THE NORTH TO NORTHWEST AT AROUND 10 MPH TODAY...BECOMING LIGHT AND VARIABLE TO CALM WINDS FRIDAY NIGHT. && .HYDROLOGY... LIGHT RAIN SHOWERS WILL IMPACT MANY PORTIONS OF THE FORECAST AREA THROUGH THIS MORNING WITH RAINFALL AMOUNTS GENERALLY ONE TENTH OF AN INCH OR LESS. DRIER WEATHER IS EXPECTED LATE THIS AFTERNOON INTO SATURDAY MORNING BEFORE A STRONG LOW PRESSURE SYSTEM DEVELOPS NEAR THE OHIO VALLEY AND MOVES TOWARDS THE EASTERN GREAT LAKES REGION. PERIODS OF MODERATE TO HEAVY RAINFALL ARE POSSIBLE LATE SATURDAY AFTERNOON INTO SUNDAY...DEPENDING ON THE EVENTUAL TRACK AND EVOLUTION OF LOW PRESSURE DEVELOPING ACROSS THE OHIO VALLEY REGION. RIGHT NOW...ONE TO UP TO TWO INCHES OF RAINFALL ARE POSSIBLE ACROSS THE HSA WITH UP TO 3 INCHES OR SO OVER THE EASTERN CATSKILLS...AND POSSIBLE THE EASTERN ADIRONDACKS. THE TRACK AND RAINFALL DURATION WILL DETERMINE WHERE THE HIGHER AMOUNTS WILL OCCUR. THE LATEST MMEFS GUIDANCE CONTINUES TO SUGGEST WITHIN BANK RISES TO THE CAUTION OR ALERT STAGES AT A FEW SITES AT THIS TIME. URBAN AND SMALL STREAM CONCERNS ACROSS THE HSA WILL HAVE TO BE MONITORED...AND WILL MENTION IN THE HWO. ALSO...IF CONFIDENCE INCREASES FOR THE POTENTIAL OF WIDESPREAD MINOR FLOODING...THEN A FLOOD WATCH MAY BE NEEDED FOR PORTIONS OF THE HSA LATER IN TIME. 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...NONE. VT...NONE. && $$ SYNOPSIS...BGM/WASULA NEAR TERM...BGM/WASULA SHORT TERM...BGM/WASULA LONG TERM...FRUGIS AVIATION...FRUGIS FIRE WEATHER...BGM/WASULA HYDROLOGY...BGM/WASULA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
913 AM EDT FRI JUN 26 2015 .SYNOPSIS... HOT TEMPERATURES WILL PREVAIL TODAY AS A COLD FRONT LINGERS TO OUR NORTH. SOMEWHAT COOLER TEMPERATURES AND MORE WIDESPREAD THUNDERSTORMS ARE LIKELY SATURDAY AS AN UPPER-LEVEL TROUGH DEVELOPS OVER THE EASTERN STATES. A COLD FRONT WILL CROSS THE AREA SATURDAY NIGHT WITH DRY CONDITIONS AND TEMPERATURES NEAR NORMAL ARRIVING EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... UPPER-LEVEL RIDGING OVER THE FORECAST AREA WILL HELP SUPPORT ANOTHER HOT DAY WITH HIGHS NEAR 100. SUPPORT FOR THUNDERSTORMS WILL BE MAINLY CONVERGENCE INTO A HEAT TROUGH AND POSSIBLE OUTFLOW BOUNDARIES FROM PREVIOUS CONVECTION...MAINLY IN THE NORTH PART. SOMEWHAT SHALLOW MOISTURE ASSOCIATED WITH THE UPPER-RIDGING SHOULD LIMIT COVERAGE. THE HRRR AND ARW DISPLAY ISOLATED TO SCATTERED COVERAGE MAINLY AFTER 200 PM AND IN THE NORTH PART. THE SPC WRF HAS THE GREATEST THUNDERSTORM COVERAGE AROUND 800 PM. A THREAT OF THUNDERSTORMS WILL CONTINUE TONIGHT MAINLY BECAUSE OF OUTFLOW BOUNDARY INTERACTION EARLY. THE MODELS ALSO INDICATE UPPER-LEVEL LIFT LATE AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. WE KEPT CHANCE POPS THROUGH THE NIGHT. STRONG INSTABILITY WITH CONSIDERABLE CAPE IN THE HAIL GROWTH AREA INDICATES A THREAT OF DAMAGING WIND AND HAIL WITH ANY THUNDERSTORMS THIS AFTERNOON INTO THE EVENING. THE TEMPERATURE GUIDANCE WAS CLOSE TONIGHT WITH LOWS IN THE MID AND UPPER 70S. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... AS THE UPPER TROUGH DEEPENS OVER THE EASTERN STATES...A SURFACE LOW PRESSURE SYSTEM WILL CROSS THE UPPER MISSISSIPPI RIVER VALLEY TO THE GREAT LAKES REGION. ITS ASSOCIATED COLD FRONT WILL CROSS OUR AREA SATURDAY NIGHT. EXPECT WIDESPREAD CONVECTION SATURDAY AS A COUPLE OF SHORT WAVES MOVE THROUGH AND INSTABILITY INCREASES. PW VALUES WILL BE AROUND 2.O SO LOCALLY HEAVY RAINS WILL BE ASSOCIATED WITH THUNDERSTORMS. KEPT HIGHS IN THE UPPER 80S AND LOWER 90S ON SATURDAY...WHICH ARE A FEW DEGREES BELOW GUIDANCE CONSENSUS...GIVEN CLOUDS AND PRECIP. LOWS SATURDAY NIGHT ARE EXPECTED TO RANGE FROM THE MID 60S WEST TO LOWER 70S EAST AS CONVECTION COMES TO AN END BEHIND THE COLD FRONT. && .LONG TERM /SUNDAY THROUGH THURSDAY/... GFS AND ECMWF IN GOOD AGREEMENT KEEPING THE UPPER LEVEL TROUGH ACROSS THE EASTERN STATES SUNDAY THEN SHIFTING OFF THE COAST BY THE MIDDLE OF NEXT WEEK. SURFACE HIGH PRESSURE WILL USHER IN DRIER MORE STABLE AIR BEGINNING SUNDAY AND CONTINUING THROUGH MONDAY. MOISTURE AND INSTABILITY BEGIN TO INCREASE AGAIN TUESDAY AND WEDNESDAY. HIGHS IN THE UPPER 80S SUNDAY...AROUND 90 MONDAY...AND 90 TO 95 TUESDAY AND WEDNESDAY. && .AVIATION /13Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS ARE EXPECTED FOR MUCH OF THE TAF PERIOD...BUT THERE WILL BE A THREAT OF THUNDERSTORMS. SUPPORT FOR THUNDERSTORMS WILL BE MAINLY CONVERGENCE INTO A HEAT TROUGH AND POSSIBLE OUTFLOW BOUNDARIES FROM PREVIOUS CONVECTION. SOMEWHAT SHALLOW MOISTURE ASSOCIATED WITH THE UPPER-RIDGING SHOULD LIMIT COVERAGE. THE HRRR AND ARW DISPLAY ISOLATED TO SCATTERED COVERAGE MAINLY AFTER 200 PM. THE SPC WRF HAS THE GREATEST THUNDERSTORM COVERAGE AROUND 800 PM. A THREAT OF THUNDERSTORMS WILL CONTINUE TONIGHT MAINLY BECAUSE OF OUTFLOW BOUNDARY INTERACTION EARLY. THE MODELS ALSO INDICATE UPPER-LEVEL LIFT LATE AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. THERE WILL BE A THUNDERSTORM CHANCE THROUGH THE NIGHT DESPITE NOCTURNAL COOLING. UNCERTAINTY WAS TOO HIGH TO FORECAST THUNDERSTORMS EXPLICITLY IN THE TAFS AT ISSUANCE TIME...BUT WE DID INCLUDE A VICINITY MENTION DURING THE MORE LIKELY TIME OF CONVECTION. STRONG INSTABILITY WITH CONSIDERABLE CAPE IN THE HAIL GROWTH AREA INDICATES A THREAT OF STRONG WIND AND HAIL WITH ANY THUNDERSTORMS THIS AFTERNOON INTO THE EVENING. OTHER THAN IN SHOWERS...THE THREAT OF FOG IS LOW OVERNIGHT BECAUSE OF CONTINUED INSTABILITY. EXTENDED AVIATION OUTLOOK...WIDESPREAD RESTRICTIONS IN SHOWERS AND THUNDERSTORMS MAY OCCUR SATURDAY AND SATURDAY NIGHT ASSOCIATED WITH A COLD FRONT MOVING INTO THE AREA. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 99
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1053 AM CDT FRI JUN 26 2015 .UPDATE... ISSUED AT 1045 AM CDT FRI JUN 26 2015 WILL UPDATE THE FORECAST TO EXPAND THE FLASH FLOOD WATCH FURTHER NORTH THIS AFTERNOON AND INTO MID EVENING UNTIL 10 PM TO INCLUDE ALL OF OUR CWA EXCEPT FOR KNOX...STARK AND MARSHALL COUNTIES. SHOWERS AND THUNDERSTORMS HAVE SPREAD SLOWLY AS FAR NORTH AS PEORIA BY LATE MORNING WITH HEAVIEST RAINS OVER 1 INCH ALONG A LEWISTOWN TO PEKIN TO BLOOMINGTON TO DANVILLE LINE. A QUASI STATIONARY BOUNDARY WAS NEAR I-72 AND EXTENDED TO 1013 MB SURFACE LOW PRESSURE OVER NE MO BETWEEN KIRKSVILLE AND QUINCY. ANOTHER 1013 MB SURFACE LOW PRESSURE WAS OVER SOUTHEAST MO. HRRR MODEL HANDLING THIS CONVECTION WELL AND USED THIS MODEL FOR FORECAST THIS AFTERNOON AND EVENING. SURFACE LOW PRESSURE TO QUICKLY DEEPEN TO 1006 MB AS IT TRACKS TO NEAR TERRE HAUTE INDIANA BY SUNSET. HEAVIEST RAINS TO FALL ALONG AND NORTH OF THE LOW PRESSURE TRACK AND FRONTAL BOUNDARY NORTH OF I-70 WHERE ADDITIONAL 1 INCH OF RAIN EXPECTED WITH LOCALLY 1 TO 2 MORE INCHES OF RAIN POSSIBLE FROM I-72 NORTH. SPC ALSO HAS SLIGHT RISK OF SEVERE STORMS THIS AFTERNOON OVER FAR SE IL SE OF A OLNEY TO ROBINSON LINE FOR 15% RISK OF DAMAGING WIND GUSTS AND LARGE HAIL AND 2% RISK OF TORNADOES. ENHANCED SLIGHT RISK WAS SE OF LAWERNCE COUNTY AND CENTERED OVER KY AND MID/NW TN. HIGHS MOSTLY IN THE MID 70S OVER CENTRAL IL WITH LOWER 80S IN FAR SOUTHEAST IL AND HUMID WITH DEWPOINTS IN THE MID 60S TO LOWER 70S. && .SHORT TERM...(TODAY) ISSUED AT 305 AM CDT FRI JUN 26 2015 08Z/3AM SURFACE ANALYSIS SHOWS LOW PRESSURE NEAR KANSAS CITY...WITH STATIONARY FRONTAL BOUNDARY EXTENDING E/SE INTO FAR SOUTHERN ILLINOIS. MCS THAT IMPACTED THE SE KILX CWA EARLIER THIS EVENING HAS NOW TRACKED INTO CENTRAL/EASTERN KENTUCKY...WHILE A SECOND MCS HAS DEVELOPED UPSTREAM OVER EASTERN KANSAS INTO WEST-CENTRAL MISSOURI. THIS SECOND SYSTEM WILL CONTINUE TO TRACK E/SE ALONG THE SYNOPTIC FRONT/OUTFLOW FROM PREVIOUS COMPLEX INTO SOUTHERN ILLINOIS LATER THIS MORNING. FURTHER NORTH...STRATIFORM RAIN WITH A FEW EMBEDDED THUNDERSTORMS WILL SPREAD INTO CENTRAL ILLINOIS FROM THE WEST. DUE TO EXTENSIVE CLOUD COVER NORTH OF THE FRONT...WILL ONLY MENTION ISOLATED THUNDER ALONG/NORTH OF THE I-72 CORRIDOR. FURTHER SOUTH...WILL GO WITH PREDOMINANT THUNDER CLOSER TO THE BOUNDARY AND THE MORE UNSTABLE AIRMASS ALONG/SOUTH OF I-70. LATEST DAY 1 CONVECTIVE OUTLOOK PLACES THE FAR SOUTHEAST CWA IN A SLIGHT RISK FOR SEVERE...WITH DAMAGING WIND GUSTS AND LARGE HAIL BEING THE PRIMARY THREATS LATER TODAY. HEAVIEST RAINFALL WILL ALSO BE FOCUSED ACROSS THE SOUTHEAST WHERE 1 TO 1.5 INCHES WILL BE LIKELY. .LONG TERM...(TONIGHT THROUGH THURSDAY) ISSUED AT 305 AM CDT FRI JUN 26 2015 SHORT-WAVE TROUGH EVIDENT ON CURRENT WATER VAPOR IMAGERY OVER EASTERN NEBRASKA/KANSAS WILL TRACK EASTWARD INTO INDIANA TONIGHT. SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE ALONG/AHEAD OF THIS FEATURE THIS EVENING...WITH RAIN CHANCES DIMINISHING FROM WEST TO EAST AFTER MIDNIGHT. ONCE THE WAVE PASSES TO THE EAST AND THE PERSISTENT FRONTAL BOUNDARY DRAPED ACROSS SOUTHERN ILLINOIS GETS A GOOD PUSH SOUTHWARD...COOLER AND DRIER WEATHER WILL BE ON TAP FOR SATURDAY. EVEN WITH MOSTLY SUNNY SKIES...BRISK NORTHERLY FLOW WILL KEEP TEMPS SEVERAL DEGREES BELOW NORMAL FOR THIS TIME OF YEAR IN THE MIDDLE TO UPPER 70S. SYNOPTIC PATTERN THROUGHOUT THE EXTENDED WILL FEATURE A LARGE UPPER RIDGE OVER THE ROCKIES AND A CORRESPONDING DOWNSTREAM TROUGH ACROSS THE GREAT LAKES/MIDWEST. WITH THIS PATTERN REMAINING FIRMLY IN PLACE THROUGH NEXT WEEK...A CONTINUATION OF BELOW NORMAL TEMPERATURES IS ANTICIPATED ALONG WITH PERIODIC RAIN CHANCES. SEVERAL SHORT-WAVES WILL DROP INTO THE REGION WITHIN THE BROAD NORTHWESTERLY FLOW PATTERN...HOWEVER THE EXACT TIMING AND STRENGTH OF THESE FEATURES WILL BE DIFFICULT TO DETERMINE THIS FAR OUT. BASED ON GFS/ECMWF CONSENSUS...IT APPEARS TWO DISTINCT PERIODS OF ENHANCED RAIN CHANCES ARE EMERGING. ONE LATE SUNDAY INTO MONDAY AND ANOTHER LATE TUESDAY INTO WEDNESDAY. HAVE INCLUDED MENTIONABLE POPS DURING THOSE TIME FRAMES...THEN HAVE GONE WITH A DRY FORECAST THE REST OF THE TIME. NEITHER OF THESE TWO SYSTEMS WILL HAVE NEARLY AS MUCH MOISTURE TO WORK WITH AS RECENT SYSTEMS...SO DESPITE POPS...RAINFALL AMOUNTS WILL REMAIN LIGHT NEXT WEEK. MAIN STORY WILL THE UNSEASONABLY COOL CONDITIONS...WITH HIGHS IN THE UPPER 70S AND LOWER 80S THROUGH THE ENTIRE WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 653 AM CDT FRI JUN 26 2015 LOW STRATUS AND LIGHT TO MODERATE FOG HAS OVERSPREAD THE TAF SITES THIS MORNING WHILE REMNANTS OF AN MCS WILL BE MOVING ACROSS THE AERA MOST OF THE DAY. ADDITIONAL DEVELOPMENT BEHIND THIS AREA WILL ALSO OCCUR...SO RAIN WILL CONTINUE THROUGH THE AFTERNOON AT ALL TAF SITES. IFR AND LIFR CONDITIONS ARE EXPECTED THROUGH THE MORNING AND INTO THE AFTERNOON. CONDITIONS SHOULD GRADUALLY IMPROVE LATE AFTERNOON/EARLY EVENING AT ALL SITES AS THE MCS/LOW PRESSURE AREA MOVES FURTHER EAST OF THE AREA. PCPN SHOULD END AS WELL BUT CIGS WILL REMAIN LOW. CONDITIONS FINALLY IMPROVE TO AROUND VFR AROUND MIDNIGHT. && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 10 PM CDT THIS EVENING FOR ILZ029-031- 036>038-040>057-061>063-066>068-071>073. && $$ UPDATE...07 SHORT TERM...BARNES LONG TERM...BARNES AVIATION...AUTEN
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
710 AM CDT Fri Jun 26 2015 .SHORT TERM: (Tonight through Friday) Issued at 322 AM CDT Fri Jun 26 2015 Active elements of large MCS over western MO will continue to move south and southeast early this morning while the stratiform rain area will continue to move east. RAP and HRRR continue to support the solution that stratiform rain area with moderate to occasionally heavy rain will slowly move east across the CWA today. RAP as well as the GFS/NAM show strong 850-925 moisture convergence moving from west to east across the area with PWATS near 2 inches. Will maintain going flash flood watch given these parameters and the saturated soils. Both the GFS and NAM show low level moisture convergence shifting southeast of the CWA by 00Z with the upper trough shifting east of the CWA by 06Z. Think that that the current end time of the flash flood watch of 00Z still is okay because the heavy rain should have ended by then. Rain chances overnight should be just scattered showers over the southeast half of the CWA after midnight. Temperatures will be much cooler today behind the front with cloudy skies, cold air advection, and rain. Highs in most areas will only be in the 70s. Britt .LONG TERM: (Tonight through Thursday) Issued at 322 AM CDT Fri Jun 26 2015 (Saturday and Sunday) Dry weather is expect on Saturday as subsidence sets in behind the exiting trough. Then chances of showers and thunderstorms increases Sunday and Sunday night as a shortwave trough dives down embedded in the northwestly flow aloft. MUCAPES will be in the 1500-2000 J/kg range and deep layer shear will be in the 30-40kt range which may be sufficient to produce a few isolated severe storms. (Monday through Thursday) Amplified upper pattern will dominate next week with shortwave troughs moving through the area every other day. This will keep a chance of showers and thunderstorm in the forecast during the period with below normal temperatures. Britt && .AVIATION: (For the 12z TAFs through 12z Saturday Morning) Issued at 650 AM CDT Fri Jun 26 2015 Area of rain with embedded thunderstorms will continue moving east across the area today. Have seen visibility drop as low as 3/4SM in the heaviest thunderstorms, but surprisingly the vast majority of the area remains VFR. Think some lower ceilings across northern Missouri will gradually work their way southeast across central and eastern Missouri into Illinois later this morning...though I am not certain this will occur. If the ceilings don`t move southeast..my TAFs are too pessimistic. Rain should slowly come to an end from northwest to southeast...with perhaps some showers lingering over parts of eastern Missouri and west central/southwest Illinois into the evening. Ceiling forecast is low confidence into the evening, but it looks like there is a decent chance much of the area will stay MVFR and possibly drop to IFR range tonight. Specifics for KSTL: Heaviest thunderstorms should clear Lambert in the next hour or so. Until then...there`s a decent threat for heavy rain dropping visibility to 1-2 miles. Am unsure how long the lighter rain will last...but it looks like it should stick around until early afternoon at least. However, if there`s no redevelopment behind the clearing line currently moving through central Missouri, my TAF is too pessimistic. Do not have a great deal of confidence in the ceiling forecast either. Guidance suggests that the lower ceilings over northern Missouri will drop down into the STL area later this morning/this afternoon. However, guidance hasn`t been doing a stellar job, and it looks like the lower ceilings are having some trouble making southward progress. Again, my TAF may be too pessimistic if those ceilings don`t start coming south over the next 2-3 hours. Carney && .LSX WATCHES/WARNINGS/ADVISORIES: MO...FLASH FLOOD WATCH through this evening FOR Audrain MO-Boone MO- Callaway MO-Cole MO-Franklin MO-Gasconade MO-Jefferson MO- Knox MO-Lewis MO-Lincoln MO-Marion MO-Moniteau MO-Monroe MO- Montgomery MO-Osage MO-Pike MO-Ralls MO-Shelby MO-St. Charles MO-St. Louis City MO-St. Louis MO-Ste. Genevieve MO- Warren MO. IL...FLASH FLOOD WATCH through this evening FOR Adams IL-Bond IL- Brown IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL-Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL- Pike IL-Randolph IL-St. Clair IL-Washington IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
707 AM CDT FRI JUN 26 2015 .SYNOPSIS... ISSUED AT 336 AM CDT FRI JUN 26 2015 AT 08Z...ISOLATED SHOWERS CONTINUE TO TRAIL TO THE WEST ACROSS NCTRL NEBR BUT HAVE SHOWN RECENT TRENDS OF SLOWLY DISSIPATING AS THEY DROP SOUTHWARD. MOST OF THE THUNDERSTORM ACTIVITY RESIDES ACROSS PARTS OF KS AND MO. UPSTREAM ACROSS THE WRN DAKOTAS...MT AND WYOMING SKIES ARE CLEAR IN MOST AREAS. TEMPERATURES IN WRN NEBR RANGE FROM 59 TO 64 DEGREES. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 336 AM CDT FRI JUN 26 2015 TODAY...THE H5 UPPER TROUGH AXIS AND ASSOCIATED VORT MAX AT 12Z TO BE LOCATED IN WRN IA. UPSTREAM...THERE WILL BE CHANNELIZED VORTICITY TODAY. WHILE THIS WOULD SEEM SUPPORTIVE OF AT LEAST ISOLATED SHOWERS ACROSS THE ERN HALF OF FA AS INDICATED BY THE HRRR AND RAP MODELS...LATEST NAM AND GFS ARE DRIER. A CROSS SECTION ACROSS EASTERN AREAS SHOWS SUFFICIENT MOISTURE AVBL EXCEPT THAT GENERAL SUBSIDENCE NOTED. CURRENT FCST IS DRY TODAY...ALTHOUGH ISOLATED SHOWERS WOULD BE POSSIBLE. CURRENT BAND OF SHOWERS EAST-WEST ACROSS CHERRY COUNTY TO HOLT COUNTY CONTINUES TO DIMINISH IN COVERAGE AND EXPECTED TO DISSIPATED BY 12Z. THERE IS HOWEVER INCREASING COVERAGE OF STRATUS ACROSS THE CENTRAL SANDHILLS INCLUDING THEDFORD ATTM. SATELLITE TRENDS SHOWS AREA IS DEVELOPING TO THE SOUTHWEST WITH MAINLY MID LEVEL CLOUDS COVERING NCTRL NEBR. ANY STRATUS SHOULD BEGIN TO SCATTER OUT AFTER 15Z WITH SCT TO BKN STRATOCUMULUS EXPECTED TODAY. HIGHS TODAY NEAR PREVIOUS FCST FROM 77 TO 81 DEGREES. WINDS STEADY NORTH TO NORTHEAST 5 TO 10 MPH. LOOKING SYNOPTICALLY ACROSS THE CONUS...THE UPPER RIDGE WILL INTENSIFY ACROSS THE WRN CONUS AS THE UPPER TROUGH AMPLIFIES FROM THE GREAT LAKES INTO THE MID MISSISSIPPI VALLEY. WEAK SURFACE HIGH PRESSURE WILL BUILD SOUTH FROM THE NRN INTO THE CNTRL PLAINS. TONIGHT...UPPER FLOW WILL REMAIN NWRLY AS SURFACE HIGH PRESSURE RESIDES OVER THE CENTRAL PLAINS. SKIES EXPECTED TO BE MOSTLY CLEAR AND TEMPERATURES WILL BE COOLER FROM 55 TO 59 DEGREES. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 336 AM CDT FRI JUN 26 2015 THIS WEEKEND INTO THE FIRST OF NEXT WEEK WILL SEE A RIDGE DOMINATE THE WESTERN CONUS AS A TROUGH DIGS OVER THE GREAT LAKES REGION. NORTHWEST FLOW ACROSS THE HIGH PLAINS...HOWEVER THE RIDGE RIDING SHORT WAVES/STORMS ARE EXPECTED TO REMAIN TO THE NORTHEAST OF THE CWA. TEMPS ABOVE NORMAL /MORE SUMMER LIKE/ WITH HIGHS IN THE MID 80S TO LOWER 90S. MONDAY NIGHT INTO TUESDAY A STRONG DISTURBANCE WILL RIDE THE CREST OF THE RIDGE AND CAUSE A SFC LOW PRESSURE TO DEVELOP ON THE LEE SIDE OF THE ROCKIES. BY TUESDAY NIGHT THE LOW PRESSURE ALONG WITH A TRAILING WEAK COLD FRONT WILL SLIDE SOUTH ACROSS THE CENTRAL/HIGH PLAINS. MODELS STILL DIFFERING ON THE STRENGTH OF LOW PRESSURE AND HOW STRONG THE CAP WILL BE. THUS STORMS ARE POSSIBLE BUT THERE IS GREAT UNCERTAINTY. THE LATEST GFS HAS GONE DRIER WHILE THE ECMWF HAS INCREASED QPF ACROSS THE AREA. ONE AGREEMENT IS A SLIGHT BOOST OF TEMPS FOR TUESDAY AHEAD OF THE FRONT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 705 AM CDT FRI JUN 26 2015 SOME LIFR CEILINGS EXIST ACROSS WRN NEBR...MAINLY NEAR THE KLBF TERMINAL. RECENT LIFR CEILINGS HAVE MOVED SOUTH OF KVTN WITH VFR CONDITIONS EXPECTED TODAY. AT KLBF...DURATION OF LIFR CEILINGS ARE PROBLEMATIC. UPSTREAM CONDITIONS AT TIF HAVE IMPROVED TO MVFR AND THE AREA SURROUNDING KLBF CONTINUES TO MOVE SOUTH. MVFR CEILINGS ARE FORECAST AT 13Z...IMPROVING TO VFR BY 15Z. WILL NEED TO MONITOR TRENDS AND MAKE ADJUSTMENTS AS NEEDED. && .HYDROLOGY... ISSUED AT 336 AM CDT FRI JUN 26 2015 CURRENT FLOOD WARNINGS FOR BRADY ON THE PLATTE RIVER SYSTEM AND LEWELLEN ON THE NORTH PLATTE RIVER SYSTEM REMAIN IN PLACE. RIVER LEVELS CONTINUE TO SLOWLY FALL. THE SOUTH PLATTE RIVER AT ROSCOE IS CURRENTLY JUST BELOW FLOOD STAGE AT 8.9 FEET AND WILL CONTINUE TO SLOWLY FALL THROUGH EARLY NEXT WEEK WITH THE FLOOD ADVISORY TO CONTINUE. THE SOUTH PLATTE RIVER AT NORTH PLATTE IS CURRENTLY NEAR 12.35 FEET AND WILL ALSO SLOWLY FALL THROUGH EARLY NEXT WEEK WITH THE FLOOD ADVISORY TO CONTINUE. RECENT RAINFALL FROM LAST EVENING DOES NOT APPEAR TO CAUSE CONCERN FOR ANY RISES...ONLY A SLIGHTLY LESS FALL IN STAGE IN THE NEAR TERM. RIVER LEVELS ALONG THE NORTH PLATTE RIVER UPSTREAM OF LAKE MCCONAUGHY ARE ELEVATED NEAR ACTION STAGE AT LISCO WHILE REMAINING ABOVE MINOR FLOOD STAGE AT LEWELLEN THROUGH EARLY NEXT WEEK. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...ROBERG SHORT TERM...ROBERG LONG TERM...MASEK AVIATION...ROBERG HYDROLOGY...ROBERG
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
629 AM CDT FRI JUN 26 2015 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 333 AM CDT FRI JUN 26 2015 THE CHANCE FOR THUNDERSTORMS TODAY IS THE PRIMARY FORECAST CONCERN. THEN A GENERALLY DRY AND WARMER WEEKEND...WITH THE EXCEPTION OF A SMALL CHANCE FOR STORMS SUNDAY. NORTHWEST MID LEVEL FLOW ACROSS THE PLAINS WAS NOTED ON EVENING UPPER AIR CHARTS AND SHORT TERM MODEL OUTPUT. A COUPLE OF SHORTWAVES COULD BE IDENTIFIED WITHIN THE FLOW...AND RECENT RAP HEIGHT FORECASTS ALONG WITH WATER VAPOR IMAGERY SUGGESTED ONE WAVE WAS MOVING OUT OF SOUTHEAST NEBRASKA AS OF 3 AM...AND ANOTHER WAS APPROACHING NORTHEAST NEBRASKA FROM SOUTH DAKOTA. BOTH WAVES WERE TRIGGERING SCATTERED SHOWERS AND STORMS...HOWEVER THE STRONGEST WERE IN NORTHERN KANSAS WHERE LIFT WAS MAXIMIZED JUST NORTH OF FRONTAL BOUNDARY EXTENDING FROM KANSAS CITY TO WICHITA. GIVEN NORTHWEST FLOW ALOFT...SOUTHERN STORMS MOVING OUT OF OUR AREA WILL REMAIN THERE THIS MORNING. SHORTWAVE TO THE NORTH WILL GRADUALLY WORK SOUTHEAST TODAY...BUT ABSENCE OF SURFACE BOUNDARY/LOW LEVEL CONVERGENCE SUGGESTS ACTIVITY WILL REMAIN ISOLATED TO SCATTERED IN NATURE. IN FACT...MANY SHORT RANGE MESOSCALE MODELS INCLUDING HRRR AND RAP SUGGEST A DECREASE IN ACTIVITY THROUGH THE MORNING BEFORE AFTERNOON HEATING HELPS BUBBLE UP WIDELY SCATTERED AFTERNOON CONVECTION. SO WILL PLAY THE HIGHEST POPS IN NORTHEAST NEBRASKA THIS MORNING...THEN BROADBRUSH SMALL CHANCES THROUGH THE AFTERNOON ACROSS MUCH OF EASTERN NEBRASKA AND SOUTHWEST IOWA. COULD SEE SOME LINGERING SHOWERS/STORMS IN SOUTHEAST NEBRASKA OR SOUTHWEST IOWA DURING THE EARLY EVENING BEFORE SHORTWAVE PUSHES FARTHER AWAY AND WE LOSE AFTERNOON HEATING. OTHERWISE WE WILL SEE A TENDENCY TOWARD NORTHERLY LOW LEVEL FLOW TONIGHT AND SATURDAY AS HIGH PRESSURE SETTLES ACROSS THE REGION...AND BRINGS SLIGHTLY DRIER AIR INTO OUR AREA. SHOULD SEE PLENTY OF SUNSHINE SATURDAY WITH HIGHS IN THE LOWER 80S AFTER MORNING LOWS IN THE LOWER 60S. SOUTHERLY FLOW WILL RETURN SATURDAY NIGHT AS A SHORTWAVE DIVES INTO MINNESOTA THEN EVENTUALLY IOWA/WISCONSIN/ILLINOIS. SURFACE COLD FRONT WILL FOLLOW THIS WAVE AND SWEEP THROUGH EASTERN NEBRASKA AND SOUTHWEST IOWA ON SUNDAY. CONVECTION SATURDAY NIGHT SHOULD BE CONFINED TO AREAS TO OUR NORTHEAST WHERE STRONG WARM ADVECTION IS REALIZED JUST AHEAD OF MID LEVEL WAVE. ON SUNDAY...AXIS OF BEST LIFT NEAR SHORTWAVE AND SURFACE REFLECTION WILL STILL LIE WELL TO OUR EAST AND NORTHEAST IN MINNESOTA AND IOWA...BUT COULD SEE A FEW SHOWERS OR STORMS NEAR AND EAST OF THE NEBRASKA/IOWA BORDER AS COLD FRONT SWINGS SOUTHEAST. SHOULD SEE NICE WARMING ON SUNDAY AS SOUTHWEST FLOW AHEAD AND NORTHWEST FLOW BEHIND FRONT WILL PROMOTE DECENT MIXING. HIGHS THEN SHOULD EASILY REACH THE MID AND UPPER 80S. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 333 AM CDT FRI JUN 26 2015 GENERAL MID LEVEL FLOW PATTERN CHANGES ONLY A LITTLE DURING THE WEEK. BROAD HIGH PRESSURE WILL REMAIN OVER THE SOUTHWESTERN STATES THROUGH THE PERIOD. MEANWHILE UPPER LOW IN THE EASTERN GREAT LAKES EARLY IN THE PERIOD WILL LIFT TO THE NORTHEAST...LEAVING BROAD TROUGH BEHIND OVER THE EASTERN HALF OF THE COUNTRY. IN BETWEEN THESE FEATURES...FLOW IN THE CENTRAL PLAINS WILL SHIFT FROM NEARLY NORTHERLY TO NORTHWESTERLY BY MID WEEK. SEVERAL IMPULSES RIDING OVER WESTERN RIDGE WILL ENTER THE PLAINS...BRINGING OFF AND ON THUNDERSTORM CHANCES TO OUR REGION. GFS AND ECMWF ARE IN FAIRLY GOOD AGREEMENT WITH THIS OVERALL PATTERN CHANGE...BUT DIFFER ON TIMING OF PRECIPITATION-PRODUCING SHORTWAVES. HOWEVER BOTH MODELS ARE RELATIVELY SIMILAR IN DROPPING A MORE SIGNIFICANT SHORTWAVE INTO THE PLAINS ON TUESDAY...INCREASING THUNDERSTORM CHANCES IN EASTERN NEBRASKA AND WESTERN IOWA TUESDAY NIGHT AS ATTENDANT SURFACE LOW AND FRONTAL SYSTEM MOVE THROUGH THE REGION. WILL HAVE THE HIGHEST PRECIP CHANCES AT THIS TIME...THOUGH STILL ONLY IN THE CHANCE CATEGORY AS MOISTURE RETURN AFTER SUNDAY COLD FRONT WILL BE SLOW TO OCCUR. SHOULD SEE MINIMAL RAIN CHANCES BEHIND THIS SYSTEM ON WEDNESDAY AND THURSDAY...BUT GIVEN UNCERTAINTY IN SMALL-SCALE MID LEVEL FEATURES...CAN NOT RULE OUT A STRAY STORM OR TWO. OTHERWISE EXPECT TEMPERATURES TO AVERAGE 60S AND 80S FOR LOWS AND HIGHS THROUGH THE PERIOD. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 627 AM CDT FRI JUN 26 2015 SHOWERS ARE AFFECTING KOFK THIS MORNING AND MAY AFFECT KOMA/KLNK THROUGH THE MORNING HOURS...WITH BRIEF MVFR VIS POSSIBLE. A FEW SHOWERS/STORMS ARE POSSIBLE IN THE AREA THIS AFTERNOON...BUT WITH LOW CONFIDENCE ON DEVELOPMENT AND COVERAGE...HAVE LEFT MENTION OUT OF TAFS. OTHERWISE...WILL SEE A CLEARING TREND TONIGHT...WITH WINDS BECOMING LIGHT AND VARIABLE THROUGH SATURDAY MORNING. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...DERGAN LONG TERM...DERGAN AVIATION...MAYES
AREA FORECAST DISCUSSION
NWS BISMARCK ND
834 AM CDT FRI JUN 26 2015 .UPDATE... ISSUED AT 829 AM CDT FRI JUN 26 2015 GIVEN A TIME LAGGED ENSEMBLE OF THE 09-11 UTC HRRR ITERATIONS AND A CONSENSUS OF THE 00 UTC WRF-ARW/NMM AND 06 UTC NAM...DECREASED THE OVERALL MENTION OF ISOLATED THUNDERSTORMS ACROSS CENTRAL NORTH DAKOTA TODAY...CONFINING THE MENTION TO PRIMARILY THE TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY. UPDATE ISSUED AT 639 AM CDT FRI JUN 26 2015 MAIN ADJUSTMENT TO THE FORECAST WAS TO ADD ISOLATED SHOWERS IN THE JAMES RIVER VALLEY THIS MORNING. KBIS WSR-88D SHOWS A FEW SHOWERS IN THAT AREA...AND THE LATEST HRRR HINTS THAT THEY COULD PERSIST FOR A FEW HOURS. PATCHY FOG WAS LEFT IN PLACE WITH A FEW SPOTS ACROSS WESTERN AND CENTRAL NORTH DAKOTA REPORTING REDUCED VISIBILITIES. DID NOT ADJUST POPS FOR THIS AFTERNOON WITH ISOLATED TO SCATTERED SHOWERS / THUNDERSTORMS STILL SUPPORTED IN THE HRRR AND 26.06Z NAM. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 308 AM CDT FRI JUN 26 2015 THE LATEST WATER VAPOR IMAGERY DEPICTS A NORTHWEST FLOW INTO NORTH DAKOTA WITH THE NEXT SIGNIFICANT UPSTREAM SHORTWAVE TROUGH WORKING THROUGH CENTRAL BRITISH COLUMBIA. THIS SHORTWAVE TROUGH WILL MOVE EAST THEN PIVOT SOUTHEAST AS IT SLIDES INTO SOUTH CENTRAL MANITOBA 12Z SATURDAY. IN RESPONSE...A SURFACE LOW PRESSURE AND ASSOCIATED COLD FRONT WILL EMERGE OVER SOUTHERN ALBERTA/SASKATCHEWAN INTO NORTHERN MONTANA FRIDAY EVENING/NIGHT. THE COLD FRONT WILL ENTER NORTHWESTERN NORTH DAKOTA AROUND 12Z SATURDAY. IN ADVANCE OF THIS SYSTEM FOR TODAY(FRIDAY)...A COUPLE OF SUBTLE SHORTWAVES STRETCHING FROM SOUTHERN/EASTERN SASKATCHEWAN INTO CENTRAL NORTH DAKOTA WILL HELP PRODUCE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON/EVENING. CAPE/SHEAR VALUES REMAIN WEAK AND THE LATEST HIGH RESOLUTION MODELS...ARW WEST/NMM WEST/HRRR...PORTRAY ISOLATED TO SCATTERED SHOWERS/THUNDERSTORMS...MAINLY FROM THE TURTLE MOUNTAINS SOUTH INTO THE JAMES RIVER VALLEY. THE GLOBAL MODELS EXTEND PRECIPITATION CHANCES ACROSS CENTRAL NORTH DAKOTA WITH THE FAR WEST REMAINING DRY. USED A BLEND OF THE HIGH RESOLUTION AND GLOBAL SUITE FOR POPS TODAY...AS THE SHORTWAVES INTERACT WITH THE WEAK INSTABILITY ALREADY IN PLACE THIS AFTERNOON AND EVENING. THE ISOLATED SHOWERS/THUNDERSTORMS WILL CONTINUE FRIDAY NIGHT AS A WEAK LOW LEVEL/850MB JET BRIEFLY DEVELOPS FRIDAY EVENING ADVECTING IN MOISTURE AHEAD OF THE AFOREMENTIONED SHORTWAVE TROUGH AND SURFACE FRONT. HOWEVER NOT EXPECTING ANY SEVERE WEATHER AT THIS TIME...AND SPC CONVECTIVE OUTLOOK HIGHLIGHTS GENERAL THUNDERSTORMS FRIDAY/FRIDAY NIGHT. HIGH TEMPERATURES FRIDAY AFTERNOON WILL BE IN THE LOW TO MID 80S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 308 AM CDT FRI JUN 26 2015 A WEAK COLD FRONT MOVING ACROSS THE NORTHERN PLAINS COULD BRING A CHANCE OF THUNDERSTORMS ON SATURDAY. THE MAIN CHANCES SHOULD BE IN THE EASTERN PART OF THE FORECAST AREA WITH THE BOUNDARY REACHING THAT AREA SATURDAY AFTERNOON DURING PEAK HEATING. THE THUNDERSTORM CHANCES ARE EXPECTED TO DIMINISH IN THE EVENING AS THE BOUNDARY EXITS THE REGION. DRY WEATHER IS EXPECTED SUNDAY AND MONDAY WITH H5 HEIGHTS BUILDING ACROSS NORTH DAKOTA. BY MONDAY NIGHT...THE FIRST IN A SERIES OF UPPER WAVES MOVES ACROSS IN NORTHWESTERLY FLOW ALOFT. WILL FOLLOW THE MODEL BLEND IN REGARDS TO POPS WHICH BRINGS SMALL CHANCES OF THUNDERSTORMS ACROSS AT LEAST PARTS OF WESTERN AND CENTRAL NORTH DAKOTA FROM MONDAY NIGHT AND BEYOND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 829 AM CDT FRI JUN 26 2015 MORNING FOG IS QUICKLY BURNING OFF ACROSS WESTERN AND CENTRAL NORTH DAKOTA AS OF 1330 UTC. OTHERWISE...VFR CONDITIONS ARE EXPECTED TODAY WITH SURFACE HIGH PRESSURE. ISOLATED THUNDERSTORMS MAY BE POSSIBLE IN THE KJMS VICINITY THIS AFTERNOON. FOG WILL ONCE AGAIN BE POSSIBLE TONIGHT FOR KBIS/KJMS. GIVEN UNCERTAINTY...WILL LEAVE THE MENTION OUT FOR NOW. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...KS LONG TERM...CK AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
639 AM CDT FRI JUN 26 2015 .UPDATE... ISSUED AT 639 AM CDT FRI JUN 26 2015 MAIN ADJUSTMENT TO THE FORECAST WAS TO ADD ISOLATED SHOWERS IN THE JAMES RIVER VALLEY THIS MORNING. KBIS WSR-88D SHOWS A FEW SHOWERS IN THAT AREA...AND THE LATEST HRRR HINTS THAT THEY COULD PERSIST FOR A FEW HOURS. PATCHY FOG WAS LEFT IN PLACE WITH A FEW SPOTS ACROSS WESTERN AND CENTRAL NORTH DAKOTA REPORTING REDUCED VISIBILITIES. DID NOT ADJUST POPS FOR THIS AFTERNOON WITH ISOLATED TO SCATTERED SHOWERS / THUNDERSTORMS STILL SUPPORTED IN THE HRRR AND 26.06Z NAM. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 308 AM CDT FRI JUN 26 2015 THE LATEST WATER VAPOR IMAGERY DEPICTS A NORTHWEST FLOW INTO NORTH DAKOTA WITH THE NEXT SIGNIFICANT UPSTREAM SHORTWAVE TROUGH WORKING THROUGH CENTRAL BRITISH COLUMBIA. THIS SHORTWAVE TROUGH WILL MOVE EAST THEN PIVOT SOUTHEAST AS IT SLIDES INTO SOUTH CENTRAL MANITOBA 12Z SATURDAY. IN RESPONSE...A SURFACE LOW PRESSURE AND ASSOCIATED COLD FRONT WILL EMERGE OVER SOUTHERN ALBERTA/SASKATCHEWAN INTO NORTHERN MONTANA FRIDAY EVENING/NIGHT. THE COLD FRONT WILL ENTER NORTHWESTERN NORTH DAKOTA AROUND 12Z SATURDAY. IN ADVANCE OF THIS SYSTEM FOR TODAY(FRIDAY)...A COUPLE OF SUBTLE SHORTWAVES STRETCHING FROM SOUTHERN/EASTERN SASKATCHEWAN INTO CENTRAL NORTH DAKOTA WILL HELP PRODUCE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON/EVENING. CAPE/SHEAR VALUES REMAIN WEAK AND THE LATEST HIGH RESOLUTION MODELS...ARW WEST/NMM WEST/HRRR...PORTRAY ISOLATED TO SCATTERED SHOWERS/THUNDERSTORMS...MAINLY FROM THE TURTLE MOUNTAINS SOUTH INTO THE JAMES RIVER VALLEY. THE GLOBAL MODELS EXTEND PRECIPITATION CHANCES ACROSS CENTRAL NORTH DAKOTA WITH THE FAR WEST REMAINING DRY. USED A BLEND OF THE HIGH RESOLUTION AND GLOBAL SUITE FOR POPS TODAY...AS THE SHORTWAVES INTERACT WITH THE WEAK INSTABILITY ALREADY IN PLACE THIS AFTERNOON AND EVENING. THE ISOLATED SHOWERS/THUNDERSTORMS WILL CONTINUE FRIDAY NIGHT AS A WEAK LOW LEVEL/850MB JET BRIEFLY DEVELOPS FRIDAY EVENING ADVECTING IN MOISTURE AHEAD OF THE AFOREMENTIONED SHORTWAVE TROUGH AND SURFACE FRONT. HOWEVER NOT EXPECTING ANY SEVERE WEATHER AT THIS TIME...AND SPC CONVECTIVE OUTLOOK HIGHLIGHTS GENERAL THUNDERSTORMS FRIDAY/FRIDAY NIGHT. HIGH TEMPERATURES FRIDAY AFTERNOON WILL BE IN THE LOW TO MID 80S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 308 AM CDT FRI JUN 26 2015 A WEAK COLD FRONT MOVING ACROSS THE NORTHERN PLAINS COULD BRING A CHANCE OF THUNDERSTORMS ON SATURDAY. THE MAIN CHANCES SHOULD BE IN THE EASTERN PART OF THE FORECAST AREA WITH THE BOUNDARY REACHING THAT AREA SATURDAY AFTERNOON DURING PEAK HEATING. THE THUNDERSTORM CHANCES ARE EXPECTED TO DIMINISH IN THE EVENING AS THE BOUNDARY EXITS THE REGION. DRY WEATHER IS EXPECTED SUNDAY AND MONDAY WITH H5 HEIGHTS BUILDING ACROSS NORTH DAKOTA. BY MONDAY NIGHT...THE FIRST IN A SERIES OF UPPER WAVES MOVES ACROSS IN NORTHWESTERLY FLOW ALOFT. WILL FOLLOW THE MODEL BLEND IN REGARDS TO POPS WHICH BRINGS SMALL CHANCES OF THUNDERSTORMS ACROSS AT LEAST PARTS OF WESTERN AND CENTRAL NORTH DAKOTA FROM MONDAY NIGHT AND BEYOND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 639 AM CDT FRI JUN 26 2015 PATCHY FOG IS POSSIBLE AT KDIK/KISN/KBIS THROUGH 15Z FRIDAY. OTHERWISE VFR CIGS/VSBYS NEXT 24HR. HELD ONTO VCTS AT KMOT/KBIS/KJMS FROM 22Z FRIDAY THROUGH 04Z SATURDAY. ANY SHOWER OR THUNDERSTORM THAT DEVELOPS WILL BE ISOLATED. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CK SHORT TERM...KS LONG TERM...CK AVIATION...KS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1038 AM EDT FRI JUN 26 2015 .SYNOPSIS... A LOW PRESSURE CENTER WILL APPROACH TODAY AND TONIGHT...BRINGING A WARM FRONT NORTHWARD ACROSS THE AREA TONIGHT. THE LOW WILL PULL A COLD FRONT ACROSS THE AREA SATURDAY. NEXT FRONT EARLY NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... 1030 AM UPDATE... EVALUATING THE 12Z NAM AS IT COMES IN...AND LOOKS A LITTLE TOO ACTIVE IN THE NEAR TERM...LIKE YESTERDAY. HAVE WEAKER LOW LEVEL FLOWS IN PLACE...AND LIKE THE LOOKS OF THE HRRR RIGHT NOW THAT HAVE A BREAK IN THE CONVECTION FOR A FEW HOURS. PREV DISCN... A LOW PRESSURE CENTER OVER THE CENTRAL PLAINS EARLY THIS MORNING WILL MOVE E AND DEEPEN...REACHING W CENTRAL OHIO BY DAWN SAT. THE ASSOCIATED UPPER LEVEL S/W TROUGH DEEPENS AND ACTUALLY CLOSES OFF DURING THIS TIME. CONVECTIVE COMPLEX MOVING INTO THE AREA EARLY THIS MORNING WAS ASSOCIATED WITH WARM / THETA E ADVECTION AHEAD OF THE APPROACHING SYSTEM...AND WILL LIKELY HOLD TOGETHER AT LEAST SOMEWHAT BEFORE BREAKING UP LATER THIS MORNING. MODELS KEEP WARM FRONT S OF THE AREA MOST OF THE DAY TODAY...NOT PUSHING N IN EARNEST UNTIL LATE TODAY AND TONIGHT...IN RESPONSE TO STRENGTHENING LOW TO MID LEVEL S TO SW FLOW AHEAD OF THE APPROACHING LOW CENTER. THIS BRINGS TO QUESTION THE NATURE OF CONVECTION THIS AFTERNOON...WHICH IS LIKELY TO BE MOST INTENSE ACROSS THE FAR S. WARM ADVECTION PRECIPITATION SHOULD BECOME MORE WIDESPREAD ACROSS THE AREA LATE TODAY BEFORE SHIFTING N TONIGHT...ALLOWING FOR BREAKS IN PRECIPITATION AT LEAST ACROSS EASTERN PORTIONS OF THE AREA. CONVECTION OUT AHEAD OF THE COLD FRONT SHOULD THEN SPREAD W TO E ACROSS THE AREA OVERNIGHT TONIGHT. WITH MULTIPLE ROUNDS OF CONVECTION AND PW VALUES 1.5 TO AT TIMES CLOSE TO TWO INCHES...FLASH FLOODING IS A CONCERN...AND A FLASH FLOOD WATCH IS ISSUED FOR 2 PM TODAY THROUGH SAT. NOTWITHSTANDING THE CONVECTION THIS MORNING...WHICH WILL PRIME SRN AND PERHAPS CENTRAL PORTIONS OF THE CWA...THE THREAT THIS AFTERNOON COULD MATERIALIZE IF WARM FRONTAL PRECIPITATION MANAGES TO BE PERSISTENT ALTHOUGH THAT MAY BE MORE OF A STRAIGHT FLOOD THREAT OR JUST A PRIMER FOR TONIGHT. CONVECTION AHEAD OF THE COLD FRONT COULD THEN BRING THE POTENTIAL FOR FLASH FLOODING TONIGHT ALTHOUGH THE MODELS APPEAR TO STABILIZE THE ATMOSPHERE IN THE WARM SECTOR FAIRLY QUICKLY AFTER SUNSET. FFA IS ISSUED AREA WIDE ALTHOUGH THE THREAT IS LIKELY TO BE PIECEMEAL IN NATURE. THE WPC SLIGHT RISK FOR EXCESSIVE RAINFALL FOR TODAY AND TONIGHT IS MAINLY N OF WHERE THE WARM FRONT WILL BE MOST OF TODAY. AFTER THE QUICKLY WANING THREAT EARLY THIS MORNING...THE SEVERE THREAT IS GREATEST IN OUR FAR SRN ZONES THIS AFTERNOON BEFORE SPREADING NWD AHEAD OF THE COLD FRONT TONIGHT. THE THREAT TONIGHT IS HIGHEST IN THE W EARLY ON...WITH A DIMINISHING THREAT OVERALL OVERNIGHT TONIGHT. THE SLIGHT RISK OUTLOOK FROM SPC REFLECTS BOTH OF THESE FACTORS AS IT IS PLACED ACROSS SRN AND CENTRAL PORTIONS OF THE FCST AREA...WITH AN ENHANCED THREAT OVER SWRN PORTIONS OF THE AREA. A BIAS CORRECTED CONSENSUS BLEND WAS USED FOR TEMPERATURES ALTHOUGH THE BUST POTENTIAL IS THAT A CLOUDY...WETTER DAY WOULD HOLD HIGH TEMPERATURES DOWN. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... NO SIGNIFICANT CHANGES MADE TO THE PREVIOUS FORECAST. A STRONG COLD FRONT WILL SWEEP ACROSS THE AREA ON SATURDAY AS LOW PRESSURE LIFTS NORTHEAST ACROSS THE AREA. FRONT WILL BE TO THE EAST OF THE CWA BY SATURDAY AFTERNOON OR EVENING. COULD BE SEVERE WEATHER ON SATURDAY...MAINLY ACROSS THE EASTERN ZONES...BUT CANT BE COMPLETELY RULED OUT OTHER PLACES AS WELL. IN ADDITION...GUSTY WINDS EXPECTED ACROSS THE AREA ON SATURDAY AS THE LOW AND ASSOCIATED FRONT PUSH THROUGH THE AREA. LOW WILL CONTINUE TO PUSH OFF TO THE NORTHEAST SATURDAY NIGHT AND SUNDAY. AREA WILL BE IN A COOL MOIST PATTERN ON SUNDAY...WITH SOME LIGHT SHOWERS CONTINUING ON SUNDAY...PARTICULARLY ACROSS THE MOUNTAINS AND NORTHERN WV/SOUTHEAST OHIO ZONES IN THE NW FLOW. BRIEF HIGH PRESSURE WILL BUILD IN LATER IN THE DAY SUNDAY...FOR SOME GRADUAL CLEARING/DRYING...PARTICULARLY ACROSS THE WEST AND SOUTH. && .LONG TERM /MONDAY THROUGH THURSDAY/... GIVEN THE CONTINUATION OF A SERIES OF UPPER TROUGHS AND FRONTS MOVING ACROSS THE AREA NEXT WEEK...WILL GENERALLY KEEP THIS PERIOD UNSETTLED. HARD TO TIME THESE SYSTEMS...SO WILL BROADBRUSH AND KEEP CHANCE POPS FOR SHOWERS AND STORMS FOR EACH DAY NEXT WEEK. TEMPERATURES WILL CONTINUE TO BE MODERATE DUE TO THE CLOUDS AND SHOWERS...EVEN AS THE COOLER CANADIAN AIRMASS EXITS EAST BY MONDAY. .AVIATION /06Z FRIDAY THROUGH TUESDAY/... MORNING CONVECTIVE COMPLEX ASSOCIATED WITH A WARM FRONT WAS MOVING OUT AND DISSIPATING JUST AS QUICKLY. MVFR CONDITIONS OR BETTER EXPECTED FROM WHAT IS LEFT. THE FRONT WILL STAY S OF THE TAF SITES TODAY...SO AFTER A MIDDAY BREAK...THE SHOWERS AND THUNDERSTORMS MAY REFIRE THIS AFTERNOON BRINGING OCCASIONAL MVFR TO PERHAPS IFR CONDITIONS. A COLD FRONT AND LOW PRESSURE SYSTEM WILL BRING EVEN MORE WIDESPREAD SHOWERS AND THUNDERSTORMS TONIGHT THAT WILL LIKELY EVENTUALLY BRING IFR CONDITIONS OVERNIGHT TONIGHT. SFC FLOW WILL BE VARIABLE TO LIGHT W ACROSS NRN SITES AND MOUNTAINS OVERNIGHT TODAY AND VARIABLE TO LIGHT E ELSEWHERE BECOMING LIGHT E TO SE EVERYWHERE TONIGHT. LIGHT W TO NW FLOW ALOFT THIS MORNING WILL BECOME LIGHT SW THIS AFTERNOON AND EVENING AND THEN MODERATE TO STRONG SW OVERNIGHT TONIGHT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SATURDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: CONDITIONS IN SHOWERS AND THUNDERSTORMS WILL VARY. AFTER 12Z SATURDAY...POSSIBLE IFR IN SHOWERS AND THUNDERSTORMS SAT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH SATURDAY AFTERNOON FOR WVZ005>011-013>020-024>040-046-047. OH...FLASH FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH SATURDAY AFTERNOON FOR OHZ066-067-075-076-083>087. KY...FLASH FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH SATURDAY AFTERNOON FOR KYZ101>103-105. VA...FLASH FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH SATURDAY AFTERNOON FOR VAZ003-004. && $$ SYNOPSIS...TRM/SL NEAR TERM...TRM/26 SHORT TERM...SL LONG TERM...JMV AVIATION...TRM
AREA FORECAST DISCUSSION...UPDATED
NWS MEDFORD OR
0850 AM PDT FRI JUN 26 2015 .UPDATED MARINE DISCUSSION. .DISCUSSION...A HOT AND UNSTABLE AIR MASS WILL PERSIST OVER THE REGION DURING THE NEXT WEEK. LOW PRESSURE OFFSHORE FROM CALIFORNIA AND HIGH PRESSURE CENTERED IN THE GREAT BASIN ARE THE MAIN UPPER LEVEL FEATURES AFFECTING OUR WEATHER IN THE SHORT TERM WITH THAT STRONG RIDGING LIKELY TO PERSIST THROUGH THE WEEK. TODAY AND SATURDAY WILL BE THE HOTTEST DAYS WITH RECORD HIGHS LIKELY TO BE SET. BUT, THE FOLLOWING FIVE DAYS WILL NOT BE THAT MUCH COOLER. THE FORECAST HAS BEEN CONSISTENT IN EXPECTING VALLEY HIGHS DURING THE NEXT TWO DAYS OF 95 TO 110 DEGREES ON THE WEST SIDE OF THE CASCADES THIS AFTERNOON AND 92 TO 102 ON THE EAST SIDE. THE OTHER MAIN FOCUS OF THE FORECAST IS THE DEVELOPMENT OF THUNDERSTORMS WITH THE POTENTIAL FOR LIGHTNING TO CAUSE NEW FIRES. ATMOSPHERIC MOISTURE LEVELS WILL GRADUALLY INCREASE WITH PRECIPITABLE WATER AMOUNTS THAT WERE AT 0.50 TO 0.75 INCHES YESTERDAY TO RISE TO 0.75 TO 1.00 INCHES TODAY. THE LEAST AMOUNT OF RAINFALL WITH THUNDERSTORMS WILL BE IN THOSE THAT DEVELOP SOUTH AND EAST OF SOUTHWEST OREGON. AN EARLY AFTERNOON THUNDERSTORM CANNOT BE COMPLETELY RULED OUT, BUT THERE IS GOOD MODEL AGREEMENT BETWEEN THE NAM AND THE SREF AND RAP SHORT TERM MODELS THAT THE FIRST THUNDERSTORMS WILL DEVELOP AROUND 3 PM OVER THE HIGHER TERRAIN FROM WESTERN SISKIYOU COUNTY TO THE SISKIYOU MOUNTAINS AND CASCADES EASTWARD. COVERAGE OF STORMS WILL INCREASE DURING THE EVENING WITH A PRIMARY FOCUS FOR NORTHWARD MOVING THUNDERSTORMS FROM THE FOOTHILLS OF THE CASCADES (IN EASTERN PORTIONS OF JACKSON AND DOUGLAS COUNTIES) EASTWARD. THAT WILL NOT BE THE EXCLUSIVE LOCATION OF THUNDERSTORMS, JUST THE LIKELY FOCUS. THESE STORMS WILL BE MOVING AT 10 TO 15 KNOTS. EMBEDDED SHORTWAVES IN THE SOUTHERLY FLOW ALOFT ARE EXPECTED TO KEEP THUNDERSTORMS GOING OVERNIGHT INTO SATURDAY MORNING WITH THE HIGHEST PROBABILITY ALONG THE CASCADES. THERE IS UNCERTAINTY IN THE TRACK AND STRENGTH OF SHORTWAVES AS THE GFS HAS A FOCUS DURING THE EVENING HOURS BEFORE LIFTING THE MAJORITY OF ACTIVITY INTO NORTHERN OREGON WHILE THE NAM SOLUTION WOULD ACTUALLY INCREASE THE NUMBER OF THUNDERSTORMS IN OUR AREA DURING THE OVERNIGHT HOURS WHILE SPREADING THEM IN A SOUTHEAST RATHER THAN SOUTH FLOW ALOFT TO THE COAST AND COASTAL WATERS. THUNDERSTORMS ON SATURDAY WILL PRODUCE MORE RAINFALL BUT THEY WILL ALSO BE FASTER MOVING AT 15 TO 25 KNOTS. THUNDERSTORM COVERAGE IS EXPECTED TO BE AT ITS PEAK DURING SATURDAY AFTERNOON AND EVENING. THE PERSISTENT PATTERN WILL ONCE AGAIN PRODUCE NOCTURNAL THUNDERSTORMS SATURDAY NIGHT INTO SUNDAY MORNING. THERE IS UNCERTAINTY IN THE TIMING AND TRACK OF THE OFFSHORE LOW. THE NAM IS FASTER THAN THE GFS BUT BOTH HAVE IT MOVING NORTH TO THE SOUTHERN OREGON COAST ON SUNDAY. THIS WILL BRING IN SLIGHTLY COOLER AIR AND EVENTUALLY KICK THE CONVECTIVE ACTIVITY TO THE EAST WITH WEST SIDE OF THE CASCADES FOCUS OF THUNDERSTORMS ON SUNDAY MORNING SHIFTING TO THE EAST SIDE FOR SUNDAY EVENING INTO MONDAY. THUNDERSTORMS ON SUNDAY WILL HAVE A HIGHER PROBABILITY OF PRODUCING SEVERE WIND GUSTS. THE TROUGH WITH A MUCH DRIER AIR MASS WILL BE IN PLACE OVER THE PACIFIC NORTHWEST ON MONDAY. THUS, A SLIGHT CHANCE OF THUNDERSTORMS WILL BE NEARLY LIMITED TO ONLY LAKE AND MODOC COUNTIES. MONDAY NIGHT SHOULD TRANSPIRE WITHOUT THUNDERSTORMS. RIDGING FROM THE GREAT BASIN IS EXPECTED TO REBUILD INTO OUR AREA TUESDAY FOR THE START OF ANOTHER WARMING TREND INTO THURSDAY. THIS WILL ALSO SEND HIGHER AMOUNTS OF MOISTURE INTO THE EAST SIDE ON TUESDAY THAT WILL EXPAND FARTHER WEST...TO THE WEST SIDE ON WEDNESDAY FOR ANOTHER EPISODE OF A SLIGHT CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS. THE PROBABILITY WILL BE THE LOWEST FOR THE COAST AND DOUGLAS COUNTY. FORECAST UNCERTAINTY INCREASES BEYOND WEDNESDAY AS THE ECMWF MODEL INDICATES A STRONG TROUGH MOVING INTO THE PACIFIC NORTHWEST WILL FINALLY CHANGE THE PATTERN AND BRING SOME COOLING FOR THE END OF THE WEEK, BUT THE GFS IS PERSISTENT AND LEAVES THE HOT GREAT BASIN RIDGE IN COMMAND. FOR NOW, WE WILL LEAN TOWARD PERSISTENCE. && .AVIATION...FOR THE 26/12Z TAF CYCLE...LOW CLOUDS WILL CONTINUE ALONG THE NORTH COAST WITH IFR TO LIFR CIGS THIS MORNING GRADUALLY RISING TO MVFR THIS AFTERNOON. ELSEWHERE VFR CONDITIONS WILL PREVAIL. LATE THIS AFTERNOON INTO THE EVENING ISOLATED THUNDERSTORMS ARE EXPECTED ALONG AND NEAR THE OREGON CASCADES...THE UPPER KLAMATH BASIN...AND WESTERN SISKIYOU COUNTY. THE BEST CHANCE OF THUNDERSTORMS IS IN THE 00-06Z TIME FRAME FOR THIS TAF CYCLE AT KLMT AND KRBG. THESE STORMS ARE EXPECTED TO BE HIGH-BASED, DRY, AND THEREFORE COULD CONTAIN GUSTY OUTFLOW WINDS AND POSSIBLY ISOLATED MICROBURSTS. BTL/SPILDE && .MARINE...UPDATED 900 AM PDT FRIDAY 26 JUNE 2015...A THERMAL TROUGH WILL BRING GALE FORCE NORTH WINDS SOUTH OF CAPE BLANCO TODAY WITH VERY STEEP WIND WAVE DOMINATED SEAS. AS IS TYPICAL WITH THERMAL TROUGH WIND PATTERNS...CONFIDENCE IS ONLY MODERATE ON EXACTLY HOW CLOSE TO SHORE THE GALES REACH...WITH THE FORECAST REFLECTING GALES BEYOND 10 NM FROM SHORE TODAY. THE THERMAL TROUGH WILL WEAKEN AND BOTH WINDS AND SEAS ARE EXPECTED TO LOWER THIS WEEKEND. THUNDERSTORMS ARE POSSIBLE TONIGHT INTO SATURDAY MORNING WITHIN 10 NM FROM SHORE. THE THERMAL TROUGH WILL THEN STRENGTHEN AGAIN MONDAY AND TUESDAY WITH CONDITIONS AT LEAST HAZARDOUS TO SMALL CRAFT. STRONGEST WINDS AND SEAS WILL AGAIN BE SOUTH OF CAPE BLANCO. SK/SPILDE && .FIRE WEATHER...UPDATED 400 AM PDT FRIDAY 26 JUNE 2015...HAVE MADE NO CHANGES WITH RESPECT TO THE RED FLAG WARNING (RFWMFR) HEADLINES IN PLACE ACROSS THE AREA BEGINNING LATER THIS AFTERNOON. MODELS CONTINUE TO SHOW MOISTURE INCREASING IN THE SOUTH TO SOUTHEAST FLOW DEVELOPING ALOFT IN A CORRIDOR BETWEEN AN UPPER LOW OFFSHORE AND THE MID LEVEL RIDGE CENTERED OVER THE GREAT BASIN. THIS IS A FAVORABLE THUNDERSTORM PATTERN AND THIS CORRIDOR IS AIMED RIGHT OVER SW OREGON/NORCAL, WHERE ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP LATER THIS AFTERNOON AND EVENING. THIS PATTERN WILL PERSIST FRIDAY NIGHT THROUGH MUCH OF THE WEEKEND AS THE UPPER LOW SLOWLY MOVES NORTHWARD ALONG THE CALIFORNIA COAST. CONFIDENCE ON THE EXACT LOCATION OF STORMS REMAINS FAIRLY LOW AS MID AND UPPER LEVEL SUPPORT FOR STORMS (SHORTWAVES) IS WEAK, BUT WITH STRONG HEATING AND THE RESULTING INSTABILITY OVER ABNORMALLY DRY FUELS ACROSS A LARGE PART OF THE AREA (NEAR-RECORD DRYNESS ALONG THE COAST)...THE THREAT FOR ABUNDANT LIGHTNING IS A BIG CONCERN FOR INITIAL ATTACK. STORMS SHOULD INITIATE OVER THE HIGHER TERRAIN THIS AFTERNOON, THEN PROPAGATE NORTHWESTWARD WITH TIME THIS EVENING AND OVERNIGHT. A STRONG MOISTURE GRADIENT WILL EXIST ALONG THE CASCADES. STORMS OVER THE EAST SIDE SHOULD BE FAIRLY DRY, WHERE PWS ARE GENERALLY LESS THAN 0.75 OF AN INCH. PWS OF 1.00-1.25 INCHES EXIST ALONG AND WEST OF THE CASCADES WHERE STORMS THAT DEVELOP SHOULD BE COMPARABLY WETTER. ANY STORMS WILL HAVE THE ABILITY TO PRODUCE GUSTY OUTFLOWS THAT COULD CAUSE NEW FIRE STARTS TO SPREAD QUICKLY. BY SATURDAY AND SATURDAY NIGHT, ADDITIONAL SHORT WAVE ACTIVITY WILL MOVE NORTH-NORTHWESTWARD INTO THE AREA AND MOISTURE SHOULD BE ADEQUATE FOR MOSTLY WET STORMS. WE STILL EXPECT SATURDAY TO BE THE MOST ACTIVE DAY (AT LEAST IN TERMS OF COVERAGE OF STORMS). BY SUNDAY, THE MODELS SUGGEST THE STRONGEST SHORT WAVE WILL MOVE THROUGH THE AREA. BUT THE AREA OF GREATEST INSTABILITY WILL SLOWLY SHIFT EASTWARD, SO AREAS ALONG AND EAST OF THE CASCADES WILL BE THE AREAS THAT LIKELY SEE THE MOST COVERAGE OF STORMS. FIRE ZONES 615 AND 618 SHOULD BE IN THE CLEAR, WHILE ISOLATED STORMS MAY STILL FORM INLAND OVER THE WEST SIDE. IT WILL BE A CLOSE CALL FOR FIRE ZONE 619. THE RIDGE AXIS SHIFTS EAST MONDAY AS THE UPPER TROUGH AXIS MOVES THROUGH AND THUNDERSTORM THREAT SHOULD BE MOSTLY CONFINED TO PORTIONS OF FIRE ZONES 624 AND 625. SPILDE && .MFR WATCHES/WARNINGS/ADVISORIES... OR...RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT SUNDAY FOR ORZ615>625. HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 5 AM PDT SUNDAY FOR ORZ023. HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 5 AM PDT SUNDAY FOR ORZ024-026. CA...RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT SUNDAY FOR CAZ280-281-284-285. HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 5 AM PDT SUNDAY FOR CAZ080-081. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT THIS EVENING FOR PZZ356-376. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT SATURDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT THIS EVENING FOR PZZ350-370. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT SATURDAY FOR PZZ370-376. GALE WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376. HAZARDOUS SEAS WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376. $$ DW/MAS
AREA FORECAST DISCUSSION...UPDATED
NWS MEDFORD OR
501 AM PDT FRI JUN 26 2015 .DISCUSSION...A HOT AND UNSTABLE AIR MASS WILL PERSIST OVER THE REGION DURING THE NEXT WEEK. LOW PRESSURE OFFSHORE FROM CALIFORNIA AND HIGH PRESSURE CENTERED IN THE GREAT BASIN ARE THE MAIN UPPER LEVEL FEATURES AFFECTING OUR WEATHER IN THE SHORT TERM WITH THAT STRONG RIDGING LIKELY TO PERSIST THROUGH THE WEEK. TODAY AND SATURDAY WILL BE THE HOTTEST DAYS WITH RECORD HIGHS LIKELY TO BE SET. BUT, AT LEAST THE FOLLOWING FIVE DAYS WILL NOT BE THAT MUCH COOLER. THE FORECAST HAS BEEN CONSISTENT IN EXPECTING VALLEY HIGHS DURING THE NEXT TWO DAYS OF 95 TO 110 DEGREES ON THE WEST SIDE OF THE CASCADES THIS AFTERNOON AND 92 TO 102 ON THE EAST SIDE. THE OTHER MAIN FOCUS OF THE FORECAST IS THE DEVELOPMENT OF THUNDERSTORMS WITH THE POTENTIAL FOR LIGHTNING TO CAUSE NEW FIRES. ATMOSPHERIC MOISTURE LEVELS WILL GRADUALLY INCREASE WITH PRECIPITABLE WATER AMOUNTS THAT WERE AT 0.50 TO 0.75 INCHES YESTERDAY TO RISE TO 0.75 TO 1.00 INCHES TODAY. THE LEAST AMOUNT OF RAINFALL WITH THUNDERSTORMS WILL BE IN THOSE THAT DEVELOP SOUTH AND EAST OF SOUTHWEST OREGON. AN EARLY AFTERNOON THUNDERSTORM CANNOT BE COMPLETELY RULED OUT, BUT THERE IS GOOD MODEL AGREEMENT BETWEEN THE NAM AND THE SREF AND RAP SHORT TERM MODELS THAT THE FIRST THUNDERSTORMS WILL DEVELOP AROUND 3 PM OVER THE HIGHER TERRAIN FROM WESTERN SISKIYOU COUNTY TO THE SISKIYOU MOUNTAINS AND CASCADES EASTWARD. COVERAGE OF STORMS WILL INCREASE DURING THE EVENING WITH A PRIMARY FOCUS FOR NORTHWARD MOVING THUNDERSTORMS FROM THE FOOTHILLS OF THE CASCADES (IN EASTERN PORTIONS OF JACKSON AND DOUGLAS COUNTIES) EASTWARD. THAT WILL NOT BE THE EXCLUSIVE LOCATION OF THUNDERSTORMS, JUST THE LIKELY FOCUS. THESE STORMS WILL BE MOVING AT 10 TO 15 KNOTS. EMBEDDED SHORTWAVES IN THE SOUTHERLY FLOW ALOFT ARE EXPECTED TO KEEP THUNDERSTORMS GOING OVERNIGHT INTO SATURDAY MORNING WITH THE HIGHEST PROBABILITY ALONG THE CASCADES. THERE IS UNCERTAINTY IN THE TRACK AND STRENGTH OF SHORTWAVES AS THE GFS HAS A FOCUS DURING THE EVENING HOURS BEFORE LIFTING THE MAJORITY OF ACTIVITY INTO NORTHERN OREGON WHILE THE NAM SOLUTION WOULD ACTUALLY INCREASE THE NUMBER OF THUNDERSTORMS IN OUR AREA DURING THE OVERNIGHT HOURS WHILE SPREADING THEM IN A SOUTHEAST RATHER THAN SOUTH FLOW ALOFT TO THE COAST AND COASTAL WATERS. THUNDERSTORMS ON SATURDAY WILL PRODUCE MORE RAINFALL BUT THEY WILL ALSO BE FASTER MOVING AT 15 TO 25 KNOTS. THUNDERSTORM COVERAGE IS EXPECTED TO BE AT ITS PEAK DURING SATURDAY AFTERNOON AND EVENING. THE PERSISTENT PATTERN WILL ONCE AGAIN PRODUCE NOCTURNAL THUNDERSTORMS SATURDAY NIGHT INTO SUNDAY MORNING. THERE IS UNCERTAINTY IN THE TIMING AND TRACK OF THE OFFSHORE LOW. THE NAM IS FASTER THAN THE GFS BUT BOTH HAVE IT MOVING NORTH TO THE SOUTHERN OREGON COAST ON SUNDAY. THIS WILL BRING IN SLIGHTLY COOLER AIR AND EVENTUALLY KICK THE CONVECTIVE ACTIVITY TO THE EAST WITH WEST SIDE OF THE CASCADES FOCUS OF THUNDERSTORMS ON SUNDAY MORNING SHIFTING TO THE EAST SIDE FOR SUNDAY EVENING INTO MONDAY. THUNDERSTORMS ON SUNDAY WILL HAVE A HIGHER PROBABILITY OF PRODUCING SEVERE WIND GUSTS. THE TROUGH WITH A MUCH DRIER AIR MASS WILL BE IN PLACE OVER THE PACIFIC NORTHWEST ON MONDAY. THUS, A SLIGHT CHANCE OF THUNDERSTORMS WILL BE NEARLY LIMITED TO ONLY LAKE AND MODOC COUNTIES. MONDAY NIGHT SHOULD TRANSPIRE WITHOUT THUNDERSTORMS. RIDGING FROM THE GREAT BASIN IS EXPECTED TO REBUILD INTO OUR AREA TUESDAY FOR THE START OF ANOTHER WARMING TREND INTO THURSDAY. THIS WILL ALSO SEND HIGHER AMOUNTS OF MOISTURE INTO THE EAST SIDE ON TUESDAY THAT WILL EXPAND FARTHER WEST...TO THE WEST SIDE ON WEDNESDAY FOR ANOTHER EPISODE OF A SLIGHT CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS. THE PROBABILITY WILL BE THE LOWEST FOR THE COAST AND DOUGLAS COUNTY. FORECAST UNCERTAINTY INCREASES BEYOND WEDNESDAY AS THE ECMWF MODEL INDICATES A STRONG TROUGH MOVING INTO THE PACIFIC NORTHWEST WILL FINALLY CHANGE THE PATTERN AND BRING SOME COOLING FOR THE END OF THE WEEK, BUT THE GFS IS PERSISTENT AND LEAVES THE HOT GREAT BASIN RIDGE IN COMMAND. FOR NOW, WE WILL LEAN TOWARD PERSISTENCE. && .AVIATION...FOR THE 26/12Z TAF CYCLE...LOW CLOUDS WILL CONTINUE ALONG THE NORTH COAST WITH IFR TO LIFR CIGS THIS MORNING GRADUALLY RISING TO MVFR THIS AFTERNOON. ELSEWHERE VFR CONDITIONS WILL PREVAIL. LATE THIS AFTERNOON INTO THE EVENING ISOLATED THUNDERSTORMS ARE EXPECTED ALONG AND NEAR THE OREGON CASCADES...THE UPPER KLAMATH BASIN...AND WESTERN SISKIYOU COUNTY. THE BEST CHANCE OF THUNDERSTORMS IS IN THE 00-06Z TIME FRAME FOR THIS TAF CYCLE AT KLMT AND KRBG. THESE STORMS ARE EXPECTED TO BE HIGH-BASED, DRY, AND THEREFORE COULD CONTAIN GUSTY OUTFLOW WINDS AND POSSIBLY ISOLATED MICROBURSTS. BTL/SPILDE && .MARINE...UPDATED 300 AM PDT FRIDAY 26 JUNE 2015...A THERMAL TROUGH WILL BRING GALE FORCE NORTH WINDS SOUTH OF CAPE BLANCO TODAY WITH VERY STEEP WIND WAVE DOMINATED SEAS. THE THERMAL TROUGH WILL WEAKEN AND BOTH WINDS AND SEAS ARE EXPECTED TO LOWER THIS WEEKEND. THUNDERSTORMS ARE POSSIBLE TONIGHT INTO SATURDAY MORNING. THE THERMAL TROUGH WILL THEN STRENGTHEN AGAIN MONDAY AND TUESDAY WITH CONDITIONS AT LEAST HAZARDOUS TO SMALL CRAFT. STRONGEST WINDS AND SEAS WILL AGAIN BE SOUTH OF CAPE BLANCO. SPILDE && .FIRE WEATHER...UPDATED 400 AM PDT FRIDAY 26 JUNE 2015...HAVE MADE NO CHANGES WITH RESPECT TO THE RED FLAG WARNING (RFWMFR) HEADLINES IN PLACE ACROSS THE AREA BEGINNING LATER THIS AFTERNOON. MODELS CONTINUE TO SHOW MOISTURE INCREASING IN THE SOUTH TO SOUTHEAST FLOW DEVELOPING ALOFT IN A CORRIDOR BETWEEN AN UPPER LOW OFFSHORE AND THE MID LEVEL RIDGE CENTERED OVER THE GREAT BASIN. THIS IS A FAVORABLE THUNDERSTORM PATTERN AND THIS CORRIDOR IS AIMED RIGHT OVER SW OREGON/NORCAL, WHERE ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP LATER THIS AFTERNOON AND EVENING. THIS PATTERN WILL PERSIST FRIDAY NIGHT THROUGH MUCH OF THE WEEKEND AS THE UPPER LOW SLOWLY MOVES NORTHWARD ALONG THE CALIFORNIA COAST. CONFIDENCE ON THE EXACT LOCATION OF STORMS REMAINS FAIRLY LOW AS MID AND UPPER LEVEL SUPPORT FOR STORMS (SHORTWAVES) IS WEAK, BUT WITH STRONG HEATING AND THE RESULTING INSTABILITY OVER ABNORMALLY DRY FUELS ACROSS A LARGE PART OF THE AREA (NEAR-RECORD DRYNESS ALONG THE COAST)...THE THREAT FOR ABUNDANT LIGHTNING IS A BIG CONCERN FOR INITIAL ATTACK. STORMS SHOULD INITIATE OVER THE HIGHER TERRAIN THIS AFTERNOON, THEN PROPAGATE NORTHWESTWARD WITH TIME THIS EVENING AND OVERNIGHT. A STRONG MOISTURE GRADIENT WILL EXIST ALONG THE CASCADES. STORMS OVER THE EAST SIDE SHOULD BE FAIRLY DRY, WHERE PWS ARE GENERALLY LESS THAN 0.75 OF AN INCH. PWS OF 1.00-1.25 INCHES EXIST ALONG AND WEST OF THE CASCADES WHERE STORMS THAT DEVELOP SHOULD BE COMPARABLY WETTER. ANY STORMS WILL HAVE THE ABILITY TO PRODUCE GUSTY OUTFLOWS THAT COULD CAUSE NEW FIRE STARTS TO SPREAD QUICKLY. BY SATURDAY AND SATURDAY NIGHT, ADDITIONAL SHORT WAVE ACTIVITY WILL MOVE NORTH-NORTHWESTWARD INTO THE AREA AND MOISTURE SHOULD BE ADEQUATE FOR MOSTLY WET STORMS. WE STILL EXPECT SATURDAY TO BE THE MOST ACTIVE DAY (AT LEAST IN TERMS OF COVERAGE OF STORMS). BY SUNDAY, THE MODELS SUGGEST THE STRONGEST SHORT WAVE WILL MOVE THROUGH THE AREA. BUT THE AREA OF GREATEST INSTABILITY WILL SLOWLY SHIFT EASTWARD, SO AREAS ALONG AND EAST OF THE CASCADES WILL BE THE AREAS THAT LIKELY SEE THE MOST COVERAGE OF STORMS. FIRE ZONES 615 AND 618 SHOULD BE IN THE CLEAR, WHILE ISOLATED STORMS MAY STILL FORM INLAND OVER THE WEST SIDE. IT WILL BE A CLOSE CALL FOR FIRE ZONE 619. THE RIDGE AXIS SHIFTS EAST MONDAY AS THE UPPER TROUGH AXIS MOVES THROUGH AND THUNDERSTORM THREAT SHOULD BE MOSTLY CONFINED TO PORTIONS OF FIRE ZONES 624 AND 625. SPILDE && .MFR WATCHES/WARNINGS/ADVISORIES... OR...RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT SUNDAY FOR ORZ615>625. HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 5 AM PDT SUNDAY FOR ORZ023. HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 5 AM PDT SUNDAY FOR ORZ024-026. CA...RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT SUNDAY FOR CAZ280-281-284-285. HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 5 AM PDT SUNDAY FOR CAZ080-081. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT THIS EVENING FOR PZZ356-376. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT SATURDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT THIS EVENING FOR PZZ350-370. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT SATURDAY FOR PZZ370-376. GALE WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376. HAZARDOUS SEAS WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376. $$ DW/MAS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1035 AM EDT FRI JUN 26 2015 .SYNOPSIS... HIGH PRESSURE WILL WEAKEN ACROSS THE SOUTHEAST TODAY AS A COLD FRONT APPROACHES. THE COLD FRONT MOVES THROUGH SATURDAY...MOVING EAST OF THE REGION BY SUNDAY. A WEAK FRONT WILL APPROACH BY MID WEEK AND LINGER NEAR THE REGION. && .NEAR TERM /THROUGH TONIGHT/... 1030 AM EDT UPDATE...AREA IS CLEAR OF RADAR ACTIVITY AT THE MOMENT...WITH AT LEAST SOME ACTIVITY EXPECTED LATER THIS AFTERNOON. LATEST HRRR HAS SOME CONVECTION AFTER 19Z. SHEAR IS BETTER TO THE NORTH IN THE BLUE RIDGE MOUNTAINS...WITH A CONSEQUENT INCREASE IN THE POSSIBILITY FOR SEVERE WEATHER. TWEAKED TEMPERATURES...SKY...AND POP TO ACCOUNT FOR LATEST OBSERVATIONS AND HRRR EXPECTATIONS. AS OF 6 AM...AIDED BY ENCROACHING OUTFLOW BOUNDARIES...A FEW SHOWERS SHOULD PERCOLATE ALONG THE TENN BORDER COUNTIES BEFORE ASHING OUT LATER THIS MORNING. OTHERWISE...VARYING DEGREES OF HIGH LVL DEBRIS CLOUDS WILL GIVE WAY TO DEVELOPING CU. THERE REMAINS THE POSSIBILITY OF DEEP CONVECTIVE REMNANTS FROM KY MCS ACTIVITY REACHING THE NC MTNS BY DAYBREAK BEFORE ASHING OUT COMPLETELY BY MID-MORNING. WILL CONTINUE TO MONITOR CONVECTION ALLOWING MODELS AND UPSTREAM TRENDS. EXPECTING AN UPTICK IN FORCING AND FLOW AS THE AFTERNOON AND EVENING WEARS ON AS S/WV ENERGY ENCROACHES THE SE CONUS AND UPPER HEIGHTS STEADILY FALL. GIVEN THIS...TSTM CVRG MAY WIND UP BECOMING NUMEROUS AND POSSIBLY SVR THIS AFTERNOON GIVEN FORECAST SNDGS DEPICTING MODERATE INSTABILITY...DECENTLY STEEP LAPSE RATES AND FAVORABLE DELTA THETA-E VALUES. WILL FORECAST ONE MORE HOT DAY TODAY...CLOSE TO PERSISTENCE AND FEATURING WIDESPREAD MIDDLE AND UPPER 90S ACRS THE PIEDMONT. IMPULSES WITHIN THE QUICKENING SW FLOW MAY BE ABLE TO SUSTAIN SOME DEGREE OF TSTM ACTIVITY WELL PAST SUNSET...WILL WILL KEEP AT LEAST A TOKEN CHANCE POP INTO THE OVERNIGHT HOURS. && .SHORT TERM /SATURDAY/... AT 230 AM EDT FRIDAY...ON SATURDAY MORNING AN UPPER TROUGH WILL BE OVER THE EASTER USA...WHILE A RIDGE WILL BE OVER THE WEST. THIS PATTERN AMPLIFIES INTO SUNDAY...WHILE A CLOSED UPPER LOW CROSSES THE LOWER GREAT LAKES. A WEAKER OPEN UPPER LOW CROSSES THE UPPER GREAT LAKES ON SUNDAY NIGHT. AT THE SURFACE...A ROBUST COLD WILL APPROACH FORM THE WEST ON ON SATURDAY...CROSSING THE AREA IN THE EARLY EVENING. WHILE CAPE MAY BE SOMEWHAT MODEST...SHEAR WILL BE PRESENT...AND ORGANIZED CONVECTION CANNOT BE RULED OUT. COOLER AND DRIER AIR WILL MOVE IN BEHIND THE FRONT FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. TEMPERATURES WILL RUN BELOW NORMAL. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... AT 230 AM EDT FRIDAY...ON MONDAY AN ANOMALOUS HIGH AMPLITUDE UPPER ROUGH WILL EXTENDING ROM HUDSON BAY TO THE GULF OF MEXICO...WHILE AN UPPER RIDGE WILL BE OVER THE WESTERN USA AND WESTER CANADA. THIS PATTER PERSISTS INTO TUESDAY...THEN DEAMPLIFIES ON WEDNESDAY. ON THURSDAY THE UPPER TROUGH REAMPLIFIES SOMEWHAT...WHILE THE RIDGE TO THE WEST REMAINS RATHER FLAT. AT THE SURFACE...A SURFACE RIDGE WILL BE OVER THE SOUTHERN APPALACHIANS ON MONDAY...IN THE WAKE OF A DEPARTING COLD FRONT. THE TRAILING PORTION OF THE FRONT LIFTS NORTH ACROSS OUR AREA AS A WARM FRONT BY EARLY TUESDAY. ANOTHER COLD FRONT DROPS SOUTHEAST ACROSS OUR AREA ON WEDNESDAY...STALLING NEAR THE NC AND SC BORDER BY THURSDAY. A WEAK CAPPING INVERSION ALOFT MAY KEEP OUR AREA SOMEWHAT STABLE ON MONDAY...BUT WITH FRONTS MOVING TROUGH THE AREA AND INSTABILITY INCREASING...THE REST OF THE WEEK SHOULD BE INCREASINGLY MORE ACTIVE. TEMPERATURES WILL RUN NEAR NORMAL. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... AT KCLT...JUST VARYING DEGREES OF HIGH LVL DEBRIS CLOUDS AND A LIGHT WIND TENDING TO THE NORTH THIS MORNING EXPECTED FOR THIS MORNING. WINDS WILL BECOME SW 6-8 KTS THIS AFTERNOON AND TSTM CHANCES WILL INCREASE...ESPECIALLY AFTER 20Z. THE THREAT FOR TSTMS REDEVELOPING AND MOVING ACRS THE NC PIEDMONT WILL LINGER THROUGH LATE EVENING. ELSEWHERE...JUST A FEW SHOWERS ACRS THE WESTERN NC MTNS THIS MORNING WITH THE TSTM CVRG STEADILY INCREASING THIS AFTERNOON...A PROB30 GROUP WILL BE CARRIED FOR ALL TERMINAL LOCATIONS. TSTM CHANCES SHOULD LINGER THROUGH AT LEAST LATE EVENING WITH AT LEAST SMALL SHOWER CHANCES CONTINUING OVERNIGHT. GETTING MIXED SIGNALS WITH RESPECT TO SATURDAY MORNING FLIGHT RESTRICTION CVRG...BUT THE SREF LIMITS THE BEST CHANCES TO THE UPSLOPE AREAS OF THE SOUTHERN MOUNTAINS. OUTLOOK...A COLD FRONT WILL APPROACH FROM THE NW AND PASS THRU ON SATURDAY. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE...PARTICULARLY WHERE HEAVY RAIN FALLS LATER TODAY...AND IN THE MOUNTAIN RIVER VALLEYS. BEHIND THE COLD FRONT...A MUCH DRIER AND COOLER AIRMASS WILL OVERSPREAD THE REGION FOR EARLY NEXT WEEK...WITH A SECOND COLD FRONT POSSIBLY ARRIVING BY MID-WEEK. CONFIDENCE TABLE... 14-20Z 20-02Z 02-08Z 08-12Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 97% KAVL HIGH 100% HIGH 100% HIGH 100% MED 68% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 87% 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...JAT NEAR TERM...CSH/WJM SHORT TERM...JAT LONG TERM...JAT AVIATION...CSH
AREA FORECAST DISCUSSION
NWS ALBANY NY
447 PM EDT FRI JUN 26 2015 .SYNOPSIS... HIGH PRESSURE WILL BUILD OVER THE REGION THIS EVENING...RESULTING IN A BRIEF PERIOD OF FAIR AND DRY WEATHER. AN INTENSIFYING STORM OVER THE OHIO VALLEY WILL APPROACH ON SATURDAY...BRINGING PERIODS OF RAIN AND COOL CONDITIONS FOR THIS FIRST FULL WEEKEND OF SUMMER. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... COMING SOON... AS OF 130 PM EDT...THIS UPDATE IS TO MAKE MINOR ADJUSTMENTS TO THE POP...WX...SKY COVER...HOURLY TEMPS AND MAX TEMP GRIGDS FOR THIS AFTERNOON. PREVIOUS DISCUSSION... THE COLD FRONT HAS SLIPPED SOUTH OF THE REGION WITH THE MAIN FEATURE OF INTEREST THE UPPER LEVEL TROUGH AXIS MOVING TOWARDS THE ST LAWRENCE RIVER VALLEY PER THE LATEST HRRR/RAP40/NAM. PARTLY CLOUDY/MOSTLY CLEAR CONDITIONS WILL BECOME MOSTLY CLOUDY FROM THE CAPITAL REGION/MOHAWK VALLEY SOUTH WITH THE UPPER TROUGH PASSAGE THIS AFTERNOON. SOME ISOLD SHOWERS ARE POSSIBLE DUE TO THE CYCLONIC VORTICITY ADVECTION DUE TO THE SHORT- WAVE ROTATING AROUND THE UPPER LOW. SOME SCT SHOWERS ARE POSSIBLE OVER THE HIGHER TERRAIN. ANY RAINFALL AMOUNTS SHOULD BE LIGHT WITH A FEW HUNDREDTHS. THE LATEST HRRR INDICATES THE SHOWER SHOULD DIMINISH NORTH OF THE CAPITAL REGION/MOHAWK VALLEY IN THE EARLY PM. HIGHS MOSTLY 70 TO 80 WITH SOME UPPER 60S OVER THE HIGHER TERRAIN. INTO TONIGHT...SURFACE HIGH BUILDS AND CRESTS ACROSS THE REGION FOR A TRANQUIL PERIOD OF WEATHER. A LIGHT NORTHERLY WIND WILL SUBSIDE TO LIGHT AND VARIABLE UNDER PTCLOUDY-MOCLEAR SKIES. HOWEVER...THE METEOROLOGICAL EYES WILL BE WATCHING WHAT TRANSPIRES UPSTREAM AS NCEP MODEL SUITE AND INTERNATIONAL GUIDANCE ARE BECOMING MORE IN AGREEMENT WITH AN ANOMALOUS DIGGING/PHASING TROUGH ACROSS THE MID WEST WITH EXPANDING AREA OF CLOUDS AND RAIN/SHOWERS. CLOUD COVERAGE MAY APPROACHING OUR SOUTHERN MOST ZONES OVERNIGHT BUT IT WILL REMAIN DRY. OVERNIGHT LOWS MAINLY INTO THE 50S WITH SOME UPPER 40S ACROSS PORTIONS OF THE DACKS...BERKS...SOUTHERN GREENS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... COMING SOON... IMPRESSIVE STORM TO DEVELOP ACROSS THE OHIO VALLEY AND IMPACT OUR REGION THIS WEEKEND... THE PREVIOUS EXCELLENT AFD FOLLOWS WITH MINOR UPDATES PER THE 00Z GUIDANCE. SATURDAY...THE 26/00Z ECMWF SHOWS THE SFC WAVE MOVING A LITTLE SLOWER TOWARDS A MID LEVEL JET CONFLUENT REGION OVER E-OH AND W-PA BY MID MORNING. THE ISENTROPIC LIFT INCREASES QUICKLY ON THE 290-300K SFC BY THE LATE MORNING INTO THE AFTERNOON ESPECIALLY SOUTH AND WEST OF THE CAPITAL REGION. THE LOW-LEVEL BAROCLINIC LEAFLET STRENGTHENS BETWEEN THE RETREATING AND STRENGTHENING HIGH OFF THE NEW ENGLAND COAST /1022MB/ ...AND THE LOW PRESSURE SYSTEM MOVING TOWARDS LAKE ERIE AND WRN PA BY THE EARLY PM WITH SUB 1000MB EXPECTED. THE GFS/ECMWF ATTEMPT TO HAVE A SECONDARY LOW FORM OVER THE MID ATLANTIC REGION THROUGH THE AFTERNOON. OVER RUNNING RAINFALL AHEAD OF THE PRIMARY SFC CYCLONE...AND THE WARM FRONT SHOULD OVER SPREAD THE REGION BY THE EARLY EVENING. AN ANOMALOUS H850/925 E/SE LLJ INCREASES AHEAD OF THE SFC WAVE TO BETTER THAN 40KTS. THE LATEST GFS/ECMWF HAVE E/SE WINDS OF 45-55KTS OVER THE FCST AREA BY 8 PM SAT. PLENTY OF ATLANTIC MOISTURE ENTRAINMENT SHOULD BE ADVECTED INTO THE REGION FOR PERIODS OF MDT-HVY RAIN BY SAT EVENING. HIGHS WILL BE BELOW NORMAL WITH MID AND U60S COMMON IN THE LOWER ELEVATIONS AND M50S TO L60S OVER THE HIGHER TERRAIN ACROSS THE CATSKILLS. SATURDAY NIGHT...THIS WILL BE THE HIGHEST POTENTIAL IMPACT PERIOD...AND WILL CONTINUE WHAT THE PREVIOUS SHIFT HIGHLIGHTED IN THE SEGMENTED HWO. THE GEFS INDICATE ANOMALOUS LLJ WITH U-WIND ANOMALIES 3 TO 5 STANDARD DEVIATIONS GREATER THAN NORMAL /STRONG EASTERLIES/ AND STRONG V-WIND ANOMALIES /STRONG SOUTHERLIES/ 3 TO 5 STANDARD DEVIATIONS GREATER THAN NORMAL. HENCE...A SE LOW-LEVEL JET MAX WILL FOCUS PERIODS OF MODERATE TO HEAVY RAINFALL. THE E/SE FLOW WILL ENHANCE THE RAINFALL ALONG THE SPINE OF THE ERN DACKS...ERN CATSKILLS...SRN GREENS..BERKS...AND NORTHERN LITCHFIELD HILLS. PWATS LOOK TO BE 1 TO 2 STD DEVS ABOVE NORMAL...SLIGHTLY HIGHER SOUTH AND EAST OF THE CAPITAL DISTRICT WHERE UP TO 3 STD IS CURRENT PROGGED. THERE IS A SMALL WINDOW WHERE THE E/SE WINDS MAY GUST CLOSE TO WIND ADVISORY LEVELS OVER THE SRN GREENS IN SRN VT...NRN TACONICS...AND POSSIBLY THE NRN BERKS. IT WILL DEPEND ON HOW MUCH MOMENTUM CAN BE TRANSFERRED TO SFC THROUGH A STRONG INVERSION IN THE SOUNDINGS AND ITS OCCURRING NOCTURNALLY. WE WILL MENTION THE THREAT AND CONTINUE WHAT THE DAY SHIFT HAS IN THE HWO. IT IS HARD TO TELL HOW MUCH OF A THREAT THE RAIN WILL HAVE FOR FLOODING AT THIS TIME. 1 TO 3 INCHES LOOKS POSSIBLE SAT PM INTO SUNDAY MORNING BASED ON THE EC/WPC/CAN GGEM GUIDANCE...WITH THE MESOSCALE MODELS SHOWING SOME 3-4 INCH AMOUNTS IN THE ERN CATSKILLS...AND ERN DACKS. PER EXTENSIVE COLLABORATION FROM SURROUNDING WFOS...CONFIDENCE REMAINS LOW FOR A FLOOD WATCH AT THIS TIME...BUT WILL CONTINUE TO MONITOR AND MENTION IN THE HWO. ZONE FFG VALUES REMAIN HIGH IN THE 3/6-HR TIME FRAME. CATEGORICAL POPS WERE CONTINUED WITH RAIN...HVY AT TIMES...SATURDAY NIGHT. IN ADDITION...SHOWALTER VALUES ARE PROGGED EVEN LOWER WITH SUB ZERO VALUES ADVECTING INTO THE REGION TO WARRANT AN INCLUSION OF THUNDERSTORMS OVERNIGHT. LOWS WILL BE MAINLY IN THE 50S. SUNDAY...MODEL TRENDS NOW WANT TO ADVECT IN A DRY SLOT DURING THE DAY WHICH WILL REDUCE THE PRECIP COVERAGE AND INTENSITY ACROSS MOST OF THE REGION FOR A SMALL WINDOW OF TIME. QUESTION IS IF WE ARE ABLE TO SEE SOME INSOLATION TO ASSIST WITH DESTABILIZATION. WHILE THE MAIN THRUST OF ADVECTION WILL BE WELL TO OUR NORTH...THE VERTICALLY STACKED LOW ACROSS WESTERN NY WITH SECONDARY LOW POSSIBLY TRACKING NORTH...NARROW LINES OF CONVECTION COULD EVOLVE. WE WILL FOLLOW A BLENDED MOS VALUES WHICH REQUIRES A SLIGHT ADJUSTMENT UPWARD IN THE AFTERNOON HIGH TEMPS TO LOWER HALF OF THE 70S FOR VALLEY LOCATIONS AND 60S ELSEWHERE. && .LONG TERM /MONDAY THROUGH FRIDAY/... THE EXTENDED FORECAST BEGINS WITH A BRIEF PERIOD OF DRY WEATHER...AS A SHORT-WAVE RIDGE BUILDS IN OVER NY AND NEW ENGLAND ON MONDAY. SOME ISOLD-SCT INSTABILITY SHOWERS /AS THE COLD POOL ALOFT DRIFTS OVER NEW ENGLAND AND SE QUEBEC/ ARE POSSIBLE DURING THE AFTERNOON NORTH OF THE CAPITAL REGION/MOHAWK VALLEY ESPECIALLY OVER THE SRN DACKS...AND SRN GREENS. MOST OF THE FCST AREA SHOULD BE DRY...WITH MORE SUNSHINE FROM THE CAPITAL REGION SOUTH. TEMPS WILL STILL RUN A LITTLE BELOW NORMAL WITH H850 TEMPS IN THE +10C TO +12C RANGE DURING THE AFTERNOON. MAX TEMPS WILL BE IN THE M60S TO L70S OVER THE HILLS AND MTNS...AND MAINLY LOWER TO M70S IN THE VALLEYS /A FEW U70S IN THE MID HUDSON VALLEY/. CLOUDS BEGIN TO INCREASE FROM THE WEST MONDAY NIGHT...AS THE NEXT UPPER LEVEL TROUGH MOVES TOWARDS NY AND NEW ENGLAND. SOME WARM ADVECTION SHOWERS MAY GET CLOSE TO LOCATIONS WEST OF THE HUDSON RIVER VALLEY BTWN 06Z-12Z. LOWS WILL BE MAINLY IN THE 50S WITH A FEW LOWER 60S IN THE MID HUDSON VALLEY/NW CT. TUE-TUE NIGHT...A POTENTIAL ACTIVE WEATHER DAY...AS A WARM FRONT OR PREFRONTAL SFC TROUGH BASED ON THE GEFS/GFS/ECMWF IMPACTS THE FCST AREA WITH SHOWERS AND THUNDERSTORMS. THE SHORT-WAVE PIVOTING THROUGH THE NEUTRAL-NEGATIVELY TILTED LONG-WAVE TROUGH WILL ALSO HELP ENHANCE THE LIFT FOR THE SHOWERS AND THUNDERSTORMS. THE GFS CONTINUES TO HAVE SFC DEWPTS IN THE 60S WITH SOME L70S. NOT SURE ABOUT L70S THIS FAR OUT...BUT SBCAPES IN THE 1000-2000 J/KG RANGE ARE NOT OUT OF THE QUESTION...IF SUFFICIENT SFC DESTABILIZATION/HEATING OCCURS. THE GFS FOR TUE CONTINUES TO HAVE 0- 6 KM BULK SHEAR VALUES OF 35-40 KTS INDICATIVE OF SOME DEEP ORGANIZED CONVECTION. SOME STRONGER STORMS WILL BE POSSIBLE IN THE PM INTO THE EARLY EVENING...ESPECIALLY IF THERE IS ENOUGH SUNSHINE. THE GEFS HAVE PWATS RISE ABOUT 1-2 STANDARD DEVIATIONS ABOVE NORMAL...AS SOME LOCALLY HEAVY RAINFALL WILL BE POSSIBLE. IT WILL BE MORE HUMID WITH HIGHS IN THE 70S TO L80S. THE SHOWERS AND THUNDERSTORMS SHOULD DIMINISH OVERNIGHT WITH LOWS IN THE U50S TO L60S. WEDNESDAY-WEDNESDAY NIGHT...THE UPPER LEVEL TROUGH CONTINUES TO BE OVER SE CANADA AND THE NORTHEAST WITH BROAD CYCLONIC FLOW. THE FIRST COLD FRONT SHOULD PASS SOUTH OF THE REGION EARLY IN THE DAY. ANOTHER SFC TROUGH OR SECONDARY COLD FRONT MAY MOVE THROUGH IN THE CYCLONIC FLOW FOR SCT SHOWERS AND ISOLD THUNDERSTORMS. HIGHS WILL BE IN THE U60S TO L70S OVER THE MTNS...AND MAINLY MID AND U70S OVER THE HILLS AND VALLEY LOCATIONS. THE MEDIUM RANGE GUIDANCE HAS TRENDED DRIER WED NIGHT WITH HIGH PRESSURE RIDGING IN FROM THE GREAT LAKES REGION. COOLER AND DRIER CONDITIONS WILL RETURN WITH LOWS IN THE 50S. THURSDAY INTO FRIDAY...TEMPERED THE POPS DOWN FURTHER THURSDAY TO NOTHING OR SLIGHT CHC...AS THE ECMWF/GFS INDICATES A BRIEF PERIOD OF DRY WX WITH THE UPPER TROUGH AXIS MOVING DOWNSTREAM OF ERN NY AND WRN NEW ENGLAND...AND A SFC RIDGE MOVING IN OVER THE REGION IN THE QUASI-ZONAL FLOW UPSTREAM. LOWS PRESSURE MAY MOVE NORTHEAST FROM THE MID ATLANTIC REGION THU NIGHT INTO FRIDAY WITH INCREASING CHANCES OF SHOWERS FROM SOUTH TO NORTH. TEMPS STILL LOOK A LITTLE BELOW NORMAL TO CLOSE THE EXTENDED. && .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... VFR CONDITIONS THROUGH THE FIRST 24 HOURS...EXCEPT PERHAPS MVFR LAST COUPLE OF HOURS AT KPOU AS -RA MOVES IN TO LOWER VSBYS...PART OF LOW PRESSURE DEEPENING OVER THE OHIO VALLEY AND HEADING EAST. THINGS LOOK MUCH WORSE JUST BEYOND 24 HOURS...WITH MOISTURE AND INSTABILITY INCREASING. ONLY SUB-MARGINAL SHEAR AT KPOU TOWARD 18Z SAT. SFC WINDS SHOULD REMAIN UNDER 10 KTS AT ALL AIRPORTS. OUTLOOK... SATURDAY NIGHT: HIGH OPERATIONAL IMPACT. BREEZY DEFINITE RA...TSRA. SUNDAY: HIGH OPERATIONAL IMPACT. BREEZY DEFINITE SHRA...TSRA. SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. BREEZY CHANCE OF SHRA. MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. && .FIRE WEATHER... MINIMAL TO LOW FIRE WEATHER RELATED CONCERNS THROUGH THE WEEKEND AS A WIDESPREAD...SOAKING RAINFALL OCCURS ACROSS THE REGION SATURDAY AFTERNOON INTO SUNDAY. THE RH VALUES WILL RECOVER TO BETWEEN 75 AND 100 PERCENT TONIGHT AND REMAIN HIGH THROUGH THE WEEKEND. && .HYDROLOGY... EXCEPT FOR ISOLATED SHOWERS THIS EVENING...DRY WEATHER IS EXPECTED INTO SATURDAY MORNING BEFORE A STRONG LOW PRESSURE SYSTEM DEVELOPS NEAR THE OHIO VALLEY AND MOVES TOWARDS THE EASTERN GREAT LAKES REGION. PERIODS OF MODERATE TO HEAVY RAINFALL ARE POSSIBLE LATE SATURDAY AFTERNOON INTO EARLY SUNDAY...DEPENDING ON THE EVENTUAL TRACK AND EVOLUTION OF LOW PRESSURE DEVELOPING ACROSS THE OHIO VALLEY REGION. RIGHT NOW...ONE TO TWO INCHES OF RAINFALL ARE POSSIBLE ACROSS THE HSA WITH SOME UPSLOPE AREAS GETTING A LITTLE MORE. THE TRACK AND RAINFALL DURATION WILL DETERMINE WHERE THE HIGHER AMOUNTS WILL OCCUR. 12Z MODEL RUNS HAVE GENERALLY DECREASED THE RAINFALL AMOUNTS BY A QUARTER TO HALF AN INCH COMPARED TO PREVIOUS RUNS. THE LATEST MMEFS GUIDANCE CONTINUES TO SUGGEST WITHIN BANK RISES TO THE CAUTION OR ALERT STAGES AT ONLY A COUPLE OF SITES AT THIS TIME. URBAN AND SMALL STREAM CONCERNS ACROSS THE HSA WILL HAVE TO BE MONITORED...AND WILL MENTION IN THE HWO. ALSO...IF CONFIDENCE INCREASES FOR THE POTENTIAL OF WIDESPREAD MINOR FLOODING...THEN A FLOOD WATCH MAY BE NEEDED FOR PORTIONS OF THE HSA LATER IN TIME. 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...NONE. VT...NONE. && $$ SYNOPSIS...GJM NEAR TERM...GJM SHORT TERM...GJM LONG TERM...WASULA AVIATION...ELH FIRE WEATHER...GJM/BGM/WASULA HYDROLOGY...GJM/BGM/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
159 PM EDT FRI JUN 26 2015 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE REGION THIS AFTERNOON WITH ISOLATED SHOWERS MAINLY FROM THE MOHAWK VALLEY SOUTH AND EAST. THEREAFTER...HIGH PRESSURE WILL BUILD OVER THE REGION LATE THIS AFTERNOON INTO THIS EVENING...RESULTING IN A BRIEF PERIOD OF FAIR AND DRY WEATHER. AN INTENSIFYING STORM OVER THE OHIO VALLEY WILL APPROACH ON SATURDAY...BRINGING PERIODS OF RAIN AND COOL CONDITIONS FOR THIS FIRST FULL WEEKEND OF SUMMER. && .NEAR TERM /THROUGH TONIGHT/... AS OF 130 PM EDT...THIS UPDATE IS TO MAKE MINOR ADJUSTMENTS TO THE POP...WX...SKY COVER...HOURLY TEMPS AND MAX TEMP GRIGDS FOR THIS AFTERNOON. PREVIOUS DISCUSSION... THE COLD FRONT HAS SLIPPED SOUTH OF THE REGION WITH THE MAIN FEATURE OF INTEREST THE UPPER LEVEL TROUGH AXIS MOVING TOWARDS THE ST LAWRENCE RIVER VALLEY PER THE LATEST HRRR/RAP40/NAM. PARTLY CLOUDY/MOSTLY CLEAR CONDITIONS WILL BECOME MOSTLY CLOUDY FROM THE CAPITAL REGION/MOHAWK VALLEY SOUTH WITH THE UPPER TROUGH PASSAGE THIS AFTERNOON. SOME ISOLD SHOWERS ARE POSSIBLE DUE TO THE CYCLONIC VORTICITY ADVECTION DUE TO THE SHORT- WAVE ROTATING AROUND THE UPPER LOW. SOME SCT SHOWERS ARE POSSIBLE OVER THE HIGHER TERRAIN. ANY RAINFALL AMOUNTS SHOULD BE LIGHT WITH A FEW HUNDREDTHS. THE LATEST HRRR INDICATES THE SHOWER SHOULD DIMINISH NORTH OF THE CAPITAL REGION/MOHAWK VALLEY IN THE EARLY PM. HIGHS MOSTLY 70 TO 80 WITH SOME UPPER 60S OVER THE HIGHER TERRAIN. INTO TONIGHT...SURFACE HIGH BUILDS AND CRESTS ACROSS THE REGION FOR A TRANQUIL PERIOD OF WEATHER. A LIGHT NORTHERLY WIND WILL SUBSIDE TO LIGHT AND VARIABLE UNDER PTCLOUDY-MOCLEAR SKIES. HOWEVER...THE METEOROLOGICAL EYES WILL BE WATCHING WHAT TRANSPIRES UPSTREAM AS NCEP MODEL SUITE AND INTERNATIONAL GUIDANCE ARE BECOMING MORE IN AGREEMENT WITH AN ANOMALOUS DIGGING/PHASING TROUGH ACROSS THE MID WEST WITH EXPANDING AREA OF CLOUDS AND RAIN/SHOWERS. CLOUD COVERAGE MAY APPROACHING OUR SOUTHERN MOST ZONES OVERNIGHT BUT IT WILL REMAIN DRY. OVERNIGHT LOWS MAINLY INTO THE 50S WITH SOME UPPER 40S ACROSS PORTIONS OF THE DACKS...BERKS...SOUTHERN GREENS. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... IMPRESSIVE STORM TO DEVELOP ACROSS THE OHIO VALLEY AND IMPACT OUR REGION THIS WEEKEND... THE PREVIOUS EXCELLENT AFD FOLLOWS WITH MINOR UPDATES PER THE 00Z GUIDANCE. SATURDAY...THE 26/00Z ECMWF SHOWS THE SFC WAVE MOVING A LITTLE SLOWER TOWARDS A MID LEVEL JET CONFLUENT REGION OVER E-OH AND W-PA BY MID MORNING. THE ISENTROPIC LIFT INCREASES QUICKLY ON THE 290-300K SFC BY THE LATE MORNING INTO THE AFTERNOON ESPECIALLY SOUTH AND WEST OF THE CAPITAL REGION. THE LOW-LEVEL BAROCLINIC LEAFLET STRENGTHENS BETWEEN THE RETREATING AND STRENGTHENING HIGH OFF THE NEW ENGLAND COAST /1022MB/ ...AND THE LOW PRESSURE SYSTEM MOVING TOWARDS LAKE ERIE AND WRN PA BY THE EARLY PM WITH SUB 1000MB EXPECTED. THE GFS/ECMWF ATTEMPT TO HAVE A SECONDARY LOW FORM OVER THE MID ATLANTIC REGION THROUGH THE AFTERNOON. OVER RUNNING RAINFALL AHEAD OF THE PRIMARY SFC CYCLONE...AND THE WARM FRONT SHOULD OVER SPREAD THE REGION BY THE EARLY EVENING. AN ANOMALOUS H850/925 E/SE LLJ INCREASES AHEAD OF THE SFC WAVE TO BETTER THAN 40KTS. THE LATEST GFS/ECMWF HAVE E/SE WINDS OF 45-55KTS OVER THE FCST AREA BY 8 PM SAT. PLENTY OF ATLANTIC MOISTURE ENTRAINMENT SHOULD BE ADVECTED INTO THE REGION FOR PERIODS OF MDT-HVY RAIN BY SAT EVENING. HIGHS WILL BE BELOW NORMAL WITH MID AND U60S COMMON IN THE LOWER ELEVATIONS AND M50S TO L60S OVER THE HIGHER TERRAIN ACROSS THE CATSKILLS. SATURDAY NIGHT...THIS WILL BE THE HIGHEST POTENTIAL IMPACT PERIOD...AND WILL CONTINUE WHAT THE PREVIOUS SHIFT HIGHLIGHTED IN THE SEGMENTED HWO. THE GEFS INDICATE ANOMALOUS LLJ WITH U-WIND ANOMALIES 3 TO 5 STANDARD DEVIATIONS GREATER THAN NORMAL /STRONG EASTERLIES/ AND STRONG V-WIND ANOMALIES /STRONG SOUTHERLIES/ 3 TO 5 STANDARD DEVIATIONS GREATER THAN NORMAL. HENCE...A SE LOW-LEVEL JET MAX WILL FOCUS PERIODS OF MODERATE TO HEAVY RAINFALL. THE E/SE FLOW WILL ENHANCE THE RAINFALL ALONG THE SPINE OF THE ERN DACKS...ERN CATSKILLS...SRN GREENS..BERKS...AND NORTHERN LITCHFIELD HILLS. PWATS LOOK TO BE 1 TO 2 STD DEVS ABOVE NORMAL...SLIGHTLY HIGHER SOUTH AND EAST OF THE CAPITAL DISTRICT WHERE UP TO 3 STD IS CURRENT PROGGED. THERE IS A SMALL WINDOW WHERE THE E/SE WINDS MAY GUST CLOSE TO WIND ADVISORY LEVELS OVER THE SRN GREENS IN SRN VT...NRN TACONICS...AND POSSIBLY THE NRN BERKS. IT WILL DEPEND ON HOW MUCH MOMENTUM CAN BE TRANSFERRED TO SFC THROUGH A STRONG INVERSION IN THE SOUNDINGS AND ITS OCCURRING NOCTURNALLY. WE WILL MENTION THE THREAT AND CONTINUE WHAT THE DAY SHIFT HAS IN THE HWO. IT IS HARD TO TELL HOW MUCH OF A THREAT THE RAIN WILL HAVE FOR FLOODING AT THIS TIME. 1 TO 3 INCHES LOOKS POSSIBLE SAT PM INTO SUNDAY MORNING BASED ON THE EC/WPC/CAN GGEM GUIDANCE...WITH THE MESOSCALE MODELS SHOWING SOME 3-4 INCH AMOUNTS IN THE ERN CATSKILLS...AND ERN DACKS. PER EXTENSIVE COLLABORATION FROM SURROUNDING WFOS...CONFIDENCE REMAINS LOW FOR A FLOOD WATCH AT THIS TIME...BUT WILL CONTINUE TO MONITOR AND MENTION IN THE HWO. ZONE FFG VALUES REMAIN HIGH IN THE 3/6-HR TIME FRAME. CATEGORICAL POPS WERE CONTINUED WITH RAIN...HVY AT TIMES...SATURDAY NIGHT. IN ADDITION...SHOWALTER VALUES ARE PROGGED EVEN LOWER WITH SUB ZERO VALUES ADVECTING INTO THE REGION TO WARRANT AN INCLUSION OF THUNDERSTORMS OVERNIGHT. LOWS WILL BE MAINLY IN THE 50S. SUNDAY...MODEL TRENDS NOW WANT TO ADVECT IN A DRY SLOT DURING THE DAY WHICH WILL REDUCE THE PRECIP COVERAGE AND INTENSITY ACROSS MOST OF THE REGION FOR A SMALL WINDOW OF TIME. QUESTION IS IF WE ARE ABLE TO SEE SOME INSOLATION TO ASSIST WITH DESTABILIZATION. WHILE THE MAIN THRUST OF ADVECTION WILL BE WELL TO OUR NORTH...THE VERTICALLY STACKED LOW ACROSS WESTERN NY WITH SECONDARY LOW POSSIBLY TRACKING NORTH...NARROW LINES OF CONVECTION COULD EVOLVE. WE WILL FOLLOW A BLENDED MOS VALUES WHICH REQUIRES A SLIGHT ADJUSTMENT UPWARD IN THE AFTERNOON HIGH TEMPS TO LOWER HALF OF THE 70S FOR VALLEY LOCATIONS AND 60S ELSEWHERE. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE LARGE VERTICALLY STACKED STORM SYSTEM IMPACTING THE REGION WILL FINALLY START TO MOVE AWAY ON SUNDAY NIGHT...AS BOTH THE SFC AND UPPER LEVEL LOWS MOVE FROM UPSTATE NY TOWARDS SOUTHERN QUEBEC AND NORTHERN NEW ENGLAND. AS A RESULT...CHANCES FOR RAIN SHOWERS WILL DECREASE THROUGH THE OVERNIGHT HOURS ON SUN NIGHT...ALTHOUGH WITH CYCLONIC FLOW STILL IN PLACE...A FEW LIGHT RAIN SHOWERS AND PLENTY OF CLOUDS REMAIN POSSIBLE. MIN TEMPS LOOK TO FALL INTO THE MID 50S FOR MOST PLACES. BY MONDAY...WEAK RIDGING ALOFT WILL POKE INTO THE REGION...ALLOWING FOR PARTIAL SUNSHINE. CANNOT TOTALLY RULE OUT A BRIEF SHOWER...ESP EARLY IN THE DAY...ACROSS THE ADIRONDACKS OR SRN GREENS...BUT MOST AREAS LOOK TO STAY DRY. MAX TEMPS SHOULD REACH INTO THE MIDDLE TO UPPER 70S FOR VALLEY AREAS...WITH 60S FOR THE HIGH TERRAIN. DRY WEATHER LOOKS TO CONTINUE INTO MONDAY NIGHT WITH LOWS IN THE 50S ONCE AGAIN. WITHIN THE FLOW AT 500 HPA...ANOTHER SHORTWAVE TROUGH WILL ROTATE TOWARDS THE REGION FROM THE GREAT LAKES. COMBINED WITH A MOIST SOUTHERLY FLOW AND DAYTIME HEATING...A FEW ROUNDS OF SHOWERS AND THUNDERSTORMS CAN BE EXPECTED FOR TUESDAY...ESP DURING THE AFTN AND EVENING. CAN/T RULE OUT A FEW STRONG STORMS...ALTHOUGH WILL ULTIMATELY DEPEND ON HOW MUCH INSTABILITY WILL BE IN PLACE. MAX TEMPS LOOK TO REACH CLOSE TO 80 IN MANY VALLEY AREAS. SHOWERS AND THUNDERSTORMS WILL WIND DOWN ON TUESDAY EVENING WITH THE LOSS OF DAYTIME HEATING AND AS THE BEST UPPER LEVEL FORCING SHIFT EASTWARD. HOWEVER...MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON WEDNESDAY WITH THE BROAD UPPER LEVEL TROUGH REMAINING OVER THE AREA AND ANOTHER SHORTWAVE ROTATING BY CLOSE TO THE REGION. TEMPS ONCE AGAIN LOOK TO REACH THE UPPER 70S TO NEAR 80. DRIER WEATHER LOOKS TO RETURN FOR THE LATE WEEK PERIOD...ALTHOUGH THIS WILL BE DETERMINED BY JUST WHEN THE FLOW AT 500 HPA CAN FLATTEN OUT. WILL CONTINUE SLIGHT TO LOW CHC POPS FOR THURSDAY DUE TO THE UNCERTAINTY...WITH TEMPS MAINLY IN THE UPPER 70S. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... VFR CONDITIONS THROUGH THE FIRST 24 HOURS...EXCEPT PERHAPS MVFR LAST COUPLE OF HOURS AT KPOU AS -RA MOVES IN TO LOWER VSBYS...PART OF LOW PRESSURE DEEPENING OVER THE OHIO VALLEY AND HEADING EAST. THINGS LOOK MUCH WORSE JUST BEYOND 24 HOURS...WITH MOISTURE AND INSTABILITY INCREASING. ONLY SUB-MARGINAL SHEAR AT KPOU TOWARD 18Z SAT. SFC WINDS SHOULD REMAIN UNDER 10 KTS AT ALL AIRPORTS. OUTLOOK... SATURDAY NIGHT: HIGH OPERATIONAL IMPACT. BREEZY DEFINITE RA...TSRA. SUNDAY: HIGH OPERATIONAL IMPACT. BREEZY DEFINITE SHRA...TSRA. SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. BREEZY CHANCE OF SHRA. MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. && .FIRE WEATHER... MINIMAL TO LOW FIRE WEATHER RELATED CONCERNS THROUGH THE WEEKEND AS ISOLATED TO SCATTERED SHOWERS PERSIST INTO THIS MORNING. A BRIEF PERIOD OF DRY WEATHER IS EXPECTED LATER THIS AFTERNOON INTO EARLY SATURDAY MORNING BEFORE A WIDESPREAD...SOAKING RAINFALL OCCURS FOR THE MAJORITY OF THE REGION SATURDAY AFTERNOON INTO SUNDAY MORNING. THE RH VALUES WILL LOWER TO 40 TO 60 PERCENT TODAY WITH THE LOWER VALUES NORTH OF THE MOHAWK RIVER VALLEY. THE RH VALUES WILL HAVE AN EXCELLENT RECOVERY SATURDAY MORNING IN THE 75 TO 100 PERCENT RANGE AND REMAIN HIGH THROUGH THE DAY AS WET WEATHER SPREADS ACROSS THE ENTIRE REGION. THE WINDS WILL LIGHT FROM THE NORTH TO NORTHWEST AT AROUND 10 MPH TODAY...BECOMING LIGHT AND VARIABLE TO CALM WINDS FRIDAY NIGHT. && .HYDROLOGY... LIGHT RAIN SHOWERS WILL IMPACT MANY PORTIONS OF THE FORECAST AREA THROUGH THIS MORNING WITH RAINFALL AMOUNTS GENERALLY ONE TENTH OF AN INCH OR LESS. DRIER WEATHER IS EXPECTED LATE THIS AFTERNOON INTO SATURDAY MORNING BEFORE A STRONG LOW PRESSURE SYSTEM DEVELOPS NEAR THE OHIO VALLEY AND MOVES TOWARDS THE EASTERN GREAT LAKES REGION. PERIODS OF MODERATE TO HEAVY RAINFALL ARE POSSIBLE LATE SATURDAY AFTERNOON INTO SUNDAY...DEPENDING ON THE EVENTUAL TRACK AND EVOLUTION OF LOW PRESSURE DEVELOPING ACROSS THE OHIO VALLEY REGION. RIGHT NOW...ONE TO UP TO TWO INCHES OF RAINFALL ARE POSSIBLE ACROSS THE HSA WITH UP TO 3 INCHES OR SO OVER THE EASTERN CATSKILLS...AND POSSIBLE THE EASTERN ADIRONDACKS. THE TRACK AND RAINFALL DURATION WILL DETERMINE WHERE THE HIGHER AMOUNTS WILL OCCUR. THE LATEST MMEFS GUIDANCE CONTINUES TO SUGGEST WITHIN BANK RISES TO THE CAUTION OR ALERT STAGES AT A FEW SITES AT THIS TIME. URBAN AND SMALL STREAM CONCERNS ACROSS THE HSA WILL HAVE TO BE MONITORED...AND WILL MENTION IN THE HWO. ALSO...IF CONFIDENCE INCREASES FOR THE POTENTIAL OF WIDESPREAD MINOR FLOODING...THEN A FLOOD WATCH MAY BE NEEDED FOR PORTIONS OF THE HSA LATER IN TIME. 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...NONE. VT...NONE. && $$ SYNOPSIS...BGM/WASULA NEAR TERM...GJM/BGM/WASULA SHORT TERM...BGM/WASULA LONG TERM...FRUGIS AVIATION...ELH FIRE WEATHER...BGM/WASULA HYDROLOGY...BGM/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
138 PM EDT FRI JUN 26 2015 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE REGION THIS AFTERNOON WITH ISOLATED SHOWERS MAINLY FROM THE MOHAWK VALLEY SOUTH AND EAST. THEREAFTER...HIGH PRESSURE WILL BUILD OVER THE REGION LATE THIS AFTERNOON INTO THIS EVENING...RESULTING IN A BRIEF PERIOD OF FAIR AND DRY WEATHER. AN INTENSIFYING STORM OVER THE OHIO VALLEY WILL APPROACH ON SATURDAY...BRINGING PERIODS OF RAIN AND COOL CONDITIONS FOR THIS FIRST FULL WEEKEND OF SUMMER. && .NEAR TERM /THROUGH TONIGHT/... AS OF 130 PM EDT...THIS UPDATE IS TO MAKE MINOR ADJUSTMENTS TO THE POP...WX...SKY COVER...HOURLY TEMPS AND MAX TEMP GRIGDS FOR THIS AFTERNOON. PREVIOUS DISCUSSION... THE COLD FRONT HAS SLIPPED SOUTH OF THE REGION WITH THE MAIN FEATURE OF INTEREST THE UPPER LEVEL TROUGH AXIS MOVING TOWARDS THE ST LAWRENCE RIVER VALLEY PER THE LATEST HRRR/RAP40/NAM. PARTLY CLOUDY/MOSTLY CLEAR CONDITIONS WILL BECOME MOSTLY CLOUDY FROM THE CAPITAL REGION/MOHAWK VALLEY SOUTH WITH THE UPPER TROUGH PASSAGE THIS AFTERNOON. SOME ISOLD SHOWERS ARE POSSIBLE DUE TO THE CYCLONIC VORTICITY ADVECTION DUE TO THE SHORT- WAVE ROTATING AROUND THE UPPER LOW. SOME SCT SHOWERS ARE POSSIBLE OVER THE HIGHER TERRAIN. ANY RAINFALL AMOUNTS SHOULD BE LIGHT WITH A FEW HUNDREDTHS. THE LATEST HRRR INDICATES THE SHOWER SHOULD DIMINISH NORTH OF THE CAPITAL REGION/MOHAWK VALLEY IN THE EARLY PM. HIGHS MOSTLY 70 TO 80 WITH SOME UPPER 60S OVER THE HIGHER TERRAIN. INTO TONIGHT...SURFACE HIGH BUILDS AND CRESTS ACROSS THE REGION FOR A TRANQUIL PERIOD OF WEATHER. A LIGHT NORTHERLY WIND WILL SUBSIDE TO LIGHT AND VARIABLE UNDER PTCLOUDY-MOCLEAR SKIES. HOWEVER...THE METEOROLOGICAL EYES WILL BE WATCHING WHAT TRANSPIRES UPSTREAM AS NCEP MODEL SUITE AND INTERNATIONAL GUIDANCE ARE BECOMING MORE IN AGREEMENT WITH AN ANOMALOUS DIGGING/PHASING TROUGH ACROSS THE MID WEST WITH EXPANDING AREA OF CLOUDS AND RAIN/SHOWERS. CLOUD COVERAGE MAY APPROACHING OUR SOUTHERN MOST ZONES OVERNIGHT BUT IT WILL REMAIN DRY. OVERNIGHT LOWS MAINLY INTO THE 50S WITH SOME UPPER 40S ACROSS PORTIONS OF THE DACKS...BERKS...SOUTHERN GREENS. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... IMPRESSIVE STORM TO DEVELOP ACROSS THE OHIO VALLEY AND IMPACT OUR REGION THIS WEEKEND... THE PREVIOUS EXCELLENT AFD FOLLOWS WITH MINOR UPDATES PER THE 00Z GUIDANCE. SATURDAY...THE 26/00Z ECMWF SHOWS THE SFC WAVE MOVING A LITTLE SLOWER TOWARDS A MID LEVEL JET CONFLUENT REGION OVER E-OH AND W-PA BY MID MORNING. THE ISENTROPIC LIFT INCREASES QUICKLY ON THE 290-300K SFC BY THE LATE MORNING INTO THE AFTERNOON ESPECIALLY SOUTH AND WEST OF THE CAPITAL REGION. THE LOW-LEVEL BAROCLINIC LEAFLET STRENGTHENS BETWEEN THE RETREATING AND STRENGTHENING HIGH OFF THE NEW ENGLAND COAST /1022MB/ ...AND THE LOW PRESSURE SYSTEM MOVING TOWARDS LAKE ERIE AND WRN PA BY THE EARLY PM WITH SUB 1000MB EXPECTED. THE GFS/ECMWF ATTEMPT TO HAVE A SECONDARY LOW FORM OVER THE MID ATLANTIC REGION THROUGH THE AFTERNOON. OVER RUNNING RAINFALL AHEAD OF THE PRIMARY SFC CYCLONE...AND THE WARM FRONT SHOULD OVER SPREAD THE REGION BY THE EARLY EVENING. AN ANOMALOUS H850/925 E/SE LLJ INCREASES AHEAD OF THE SFC WAVE TO BETTER THAN 40KTS. THE LATEST GFS/ECMWF HAVE E/SE WINDS OF 45-55KTS OVER THE FCST AREA BY 8 PM SAT. PLENTY OF ATLANTIC MOISTURE ENTRAINMENT SHOULD BE ADVECTED INTO THE REGION FOR PERIODS OF MDT-HVY RAIN BY SAT EVENING. HIGHS WILL BE BELOW NORMAL WITH MID AND U60S COMMON IN THE LOWER ELEVATIONS AND M50S TO L60S OVER THE HIGHER TERRAIN ACROSS THE CATSKILLS. SATURDAY NIGHT...THIS WILL BE THE HIGHEST POTENTIAL IMPACT PERIOD...AND WILL CONTINUE WHAT THE PREVIOUS SHIFT HIGHLIGHTED IN THE SEGMENTED HWO. THE GEFS INDICATE ANOMALOUS LLJ WITH U-WIND ANOMALIES 3 TO 5 STANDARD DEVIATIONS GREATER THAN NORMAL /STRONG EASTERLIES/ AND STRONG V-WIND ANOMALIES /STRONG SOUTHERLIES/ 3 TO 5 STANDARD DEVIATIONS GREATER THAN NORMAL. HENCE...A SE LOW-LEVEL JET MAX WILL FOCUS PERIODS OF MODERATE TO HEAVY RAINFALL. THE E/SE FLOW WILL ENHANCE THE RAINFALL ALONG THE SPINE OF THE ERN DACKS...ERN CATSKILLS...SRN GREENS..BERKS...AND NORTHERN LITCHFIELD HILLS. PWATS LOOK TO BE 1 TO 2 STD DEVS ABOVE NORMAL...SLIGHTLY HIGHER SOUTH AND EAST OF THE CAPITAL DISTRICT WHERE UP TO 3 STD IS CURRENT PROGGED. THERE IS A SMALL WINDOW WHERE THE E/SE WINDS MAY GUST CLOSE TO WIND ADVISORY LEVELS OVER THE SRN GREENS IN SRN VT...NRN TACONICS...AND POSSIBLY THE NRN BERKS. IT WILL DEPEND ON HOW MUCH MOMENTUM CAN BE TRANSFERRED TO SFC THROUGH A STRONG INVERSION IN THE SOUNDINGS AND ITS OCCURRING NOCTURNALLY. WE WILL MENTION THE THREAT AND CONTINUE WHAT THE DAY SHIFT HAS IN THE HWO. IT IS HARD TO TELL HOW MUCH OF A THREAT THE RAIN WILL HAVE FOR FLOODING AT THIS TIME. 1 TO 3 INCHES LOOKS POSSIBLE SAT PM INTO SUNDAY MORNING BASED ON THE EC/WPC/CAN GGEM GUIDANCE...WITH THE MESOSCALE MODELS SHOWING SOME 3-4 INCH AMOUNTS IN THE ERN CATSKILLS...AND ERN DACKS. PER EXTENSIVE COLLABORATION FROM SURROUNDING WFOS...CONFIDENCE REMAINS LOW FOR A FLOOD WATCH AT THIS TIME...BUT WILL CONTINUE TO MONITOR AND MENTION IN THE HWO. ZONE FFG VALUES REMAIN HIGH IN THE 3/6-HR TIME FRAME. CATEGORICAL POPS WERE CONTINUED WITH RAIN...HVY AT TIMES...SATURDAY NIGHT. IN ADDITION...SHOWALTER VALUES ARE PROGGED EVEN LOWER WITH SUB ZERO VALUES ADVECTING INTO THE REGION TO WARRANT AN INCLUSION OF THUNDERSTORMS OVERNIGHT. LOWS WILL BE MAINLY IN THE 50S. SUNDAY...MODEL TRENDS NOW WANT TO ADVECT IN A DRY SLOT DURING THE DAY WHICH WILL REDUCE THE PRECIP COVERAGE AND INTENSITY ACROSS MOST OF THE REGION FOR A SMALL WINDOW OF TIME. QUESTION IS IF WE ARE ABLE TO SEE SOME INSOLATION TO ASSIST WITH DESTABILIZATION. WHILE THE MAIN THRUST OF ADVECTION WILL BE WELL TO OUR NORTH...THE VERTICALLY STACKED LOW ACROSS WESTERN NY WITH SECONDARY LOW POSSIBLY TRACKING NORTH...NARROW LINES OF CONVECTION COULD EVOLVE. WE WILL FOLLOW A BLENDED MOS VALUES WHICH REQUIRES A SLIGHT ADJUSTMENT UPWARD IN THE AFTERNOON HIGH TEMPS TO LOWER HALF OF THE 70S FOR VALLEY LOCATIONS AND 60S ELSEWHERE. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE LARGE VERTICALLY STACKED STORM SYSTEM IMPACTING THE REGION WILL FINALLY START TO MOVE AWAY ON SUNDAY NIGHT...AS BOTH THE SFC AND UPPER LEVEL LOWS MOVE FROM UPSTATE NY TOWARDS SOUTHERN QUEBEC AND NORTHERN NEW ENGLAND. AS A RESULT...CHANCES FOR RAIN SHOWERS WILL DECREASE THROUGH THE OVERNIGHT HOURS ON SUN NIGHT...ALTHOUGH WITH CYCLONIC FLOW STILL IN PLACE...A FEW LIGHT RAIN SHOWERS AND PLENTY OF CLOUDS REMAIN POSSIBLE. MIN TEMPS LOOK TO FALL INTO THE MID 50S FOR MOST PLACES. BY MONDAY...WEAK RIDGING ALOFT WILL POKE INTO THE REGION...ALLOWING FOR PARTIAL SUNSHINE. CANNOT TOTALLY RULE OUT A BRIEF SHOWER...ESP EARLY IN THE DAY...ACROSS THE ADIRONDACKS OR SRN GREENS...BUT MOST AREAS LOOK TO STAY DRY. MAX TEMPS SHOULD REACH INTO THE MIDDLE TO UPPER 70S FOR VALLEY AREAS...WITH 60S FOR THE HIGH TERRAIN. DRY WEATHER LOOKS TO CONTINUE INTO MONDAY NIGHT WITH LOWS IN THE 50S ONCE AGAIN. WITHIN THE FLOW AT 500 HPA...ANOTHER SHORTWAVE TROUGH WILL ROTATE TOWARDS THE REGION FROM THE GREAT LAKES. COMBINED WITH A MOIST SOUTHERLY FLOW AND DAYTIME HEATING...A FEW ROUNDS OF SHOWERS AND THUNDERSTORMS CAN BE EXPECTED FOR TUESDAY...ESP DURING THE AFTN AND EVENING. CAN/T RULE OUT A FEW STRONG STORMS...ALTHOUGH WILL ULTIMATELY DEPEND ON HOW MUCH INSTABILITY WILL BE IN PLACE. MAX TEMPS LOOK TO REACH CLOSE TO 80 IN MANY VALLEY AREAS. SHOWERS AND THUNDERSTORMS WILL WIND DOWN ON TUESDAY EVENING WITH THE LOSS OF DAYTIME HEATING AND AS THE BEST UPPER LEVEL FORCING SHIFT EASTWARD. HOWEVER...MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON WEDNESDAY WITH THE BROAD UPPER LEVEL TROUGH REMAINING OVER THE AREA AND ANOTHER SHORTWAVE ROTATING BY CLOSE TO THE REGION. TEMPS ONCE AGAIN LOOK TO REACH THE UPPER 70S TO NEAR 80. DRIER WEATHER LOOKS TO RETURN FOR THE LATE WEEK PERIOD...ALTHOUGH THIS WILL BE DETERMINED BY JUST WHEN THE FLOW AT 500 HPA CAN FLATTEN OUT. WILL CONTINUE SLIGHT TO LOW CHC POPS FOR THURSDAY DUE TO THE UNCERTAINTY...WITH TEMPS MAINLY IN THE UPPER 70S. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... VFR CONDITIONS THROUGH THE FIRST 24 HOURS...EXCEPT PERHAPS MVFR LAST COUPLE OF HOURS AT KPOU AS -RA MOVES IN TO LOWER VSBYS...PART OF LOW PRESSURE DEEPENING OVER THE OHIO VALLEY AND HEADING EAST. THINGS LOOK MUCH WORSE JUST BEYOND 24 HOURS...WITH MOISTURE AND INSTABILITY INCREASING. ONLY SUB-MARGINAL SHEAR AT KPOU TOWARD 18Z SAT. SFC WINDS SHOULD REMAIN UNDER 10 KTS AT ALL AIRPORTS. OUTLOOK... SATURDAY NIGHT: HIGH OPERATIONAL IMPACT. BREEZY DEFINITE RA...TSRA. SUNDAY: HIGH OPERATIONAL IMPACT. BREEZY DEFINITE SHRA...TSRA. SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. BREEZY CHANCE OF SHRA. MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. && .FIRE WEATHER... MINIMAL TO LOW FIRE WEATHER RELATED CONCERNS THROUGH THE WEEKEND AS ISOLATED TO SCATTERED SHOWERS PERSIST INTO THIS MORNING. A BRIEF PERIOD OF DRY WEATHER IS EXPECTED LATER THIS AFTERNOON INTO EARLY SATURDAY MORNING BEFORE A WIDESPREAD...SOAKING RAINFALL OCCURS FOR THE MAJORITY OF THE REGION SATURDAY AFTERNOON INTO SUNDAY MORNING. THE RH VALUES WILL LOWER TO 40 TO 60 PERCENT TODAY WITH THE LOWER VALUES NORTH OF THE MOHAWK RIVER VALLEY. THE RH VALUES WILL HAVE AN EXCELLENT RECOVERY SATURDAY MORNING IN THE 75 TO 100 PERCENT RANGE AND REMAIN HIGH THROUGH THE DAY AS WET WEATHER SPREADS ACROSS THE ENTIRE REGION. THE WINDS WILL LIGHT FROM THE NORTH TO NORTHWEST AT AROUND 10 MPH TODAY...BECOMING LIGHT AND VARIABLE TO CALM WINDS FRIDAY NIGHT. && .HYDROLOGY... LIGHT RAIN SHOWERS WILL IMPACT MANY PORTIONS OF THE FORECAST AREA THROUGH THIS MORNING WITH RAINFALL AMOUNTS GENERALLY ONE TENTH OF AN INCH OR LESS. DRIER WEATHER IS EXPECTED LATE THIS AFTERNOON INTO SATURDAY MORNING BEFORE A STRONG LOW PRESSURE SYSTEM DEVELOPS NEAR THE OHIO VALLEY AND MOVES TOWARDS THE EASTERN GREAT LAKES REGION. PERIODS OF MODERATE TO HEAVY RAINFALL ARE POSSIBLE LATE SATURDAY AFTERNOON INTO SUNDAY...DEPENDING ON THE EVENTUAL TRACK AND EVOLUTION OF LOW PRESSURE DEVELOPING ACROSS THE OHIO VALLEY REGION. RIGHT NOW...ONE TO UP TO TWO INCHES OF RAINFALL ARE POSSIBLE ACROSS THE HSA WITH UP TO 3 INCHES OR SO OVER THE EASTERN CATSKILLS...AND POSSIBLE THE EASTERN ADIRONDACKS. THE TRACK AND RAINFALL DURATION WILL DETERMINE WHERE THE HIGHER AMOUNTS WILL OCCUR. THE LATEST MMEFS GUIDANCE CONTINUES TO SUGGEST WITHIN BANK RISES TO THE CAUTION OR ALERT STAGES AT A FEW SITES AT THIS TIME. URBAN AND SMALL STREAM CONCERNS ACROSS THE HSA WILL HAVE TO BE MONITORED...AND WILL MENTION IN THE HWO. ALSO...IF CONFIDENCE INCREASES FOR THE POTENTIAL OF WIDESPREAD MINOR FLOODING...THEN A FLOOD WATCH MAY BE NEEDED FOR PORTIONS OF THE HSA LATER IN TIME. 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...NONE. VT...NONE. && $$ SYNOPSIS...BGM/WASULA NEAR TERM...GJM/BGM/WASULA SHORT TERM...BGM/WASULA LONG TERM...FRUGIS AVIATION...FRUGIS FIRE WEATHER...BGM/WASULA HYDROLOGY...BGM/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
131 PM EDT FRI JUN 26 2015 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE REGION THIS AFTERNOON WITH ISOLATED SHOWERS MAINLY FROM THE MOHAWK VALLEY SOUTH AND EAST. THEREAFTER...HIGH PRESSURE WILL BUILD OVER THE REGION LATE THIS AFTERNOON INTO THIS EVENING...RESULTING IN A BRIEF PERIOD OF FAIR AND DRY WEATHER. AN INTENSIFYING STORM OVER THE OHIO VALLEY WILL APPROACH ON SATURDAY...BRINGING PERIODS OF RAIN AND COOL CONDITIONS FOR THIS FIRST FULL WEEKEND OF SUMMER. && .NEAR TERM /THROUGH TONIGHT/... AS OF 959 AM EDT...THIS UPDATE IS TO RETOOL THE POP TRENDS AND CLOUD COVERAGE ACROSS THE REGION. THE COLD FRONT HAS SLIPPED SOUTH OF THE REGION WITH THE MAIN FEATURE OF INTEREST THE UPPER LEVEL TROUGH AXIS MOVING TOWARDS THE ST LAWRENCE RIVER VALLEY PER THE LATEST HRRR/RAP40/NAM. PARTLY CLOUDY/MOSTLY CLEAR CONDITIONS WILL BECOME MOSTLY CLOUDY FROM THE CAPITAL REGION/MOHAWK VALLEY SOUTH WITH THE UPPER TROUGH PASSAGE THIS AFTERNOON. SOME ISOLD SHOWERS ARE POSSIBLE DUE TO THE CYCLONIC VORTICITY ADVECTION DUE TO THE SHORT-WAVE ROTATING AROUND THE UPPER LOW. SOME SCT SHOWERS ARE POSSIBLE OVER THE HIGHER TERRAIN. ANY RAINFALL AMOUNTS SHOULD BE LIGHT WITH A FEW HUNDREDTHS. THE LATEST HRRR INDICATES THE SHOWER SHOULD DIMINISH NORTH OF THE CAPITAL REGION/MOHAWK VALLEY IN THE EARLY PM. HIGHS MOSTLY IN THE MID TO UPPER 70S FOR VALLEY LOCATIONS WITH UPPER 60S TO LOWER 70S FOR THE HIGHER TERRAIN. INTO TONIGHT...SURFACE HIGH BUILDS AND CRESTS ACROSS THE REGION FOR A TRANQUIL PERIOD OF WEATHER. A LIGHT NORTHERLY WIND WILL SUBSIDE TO LIGHT AND VARIABLE UNDER PTCLOUDY-MOCLEAR SKIES. HOWEVER...THE METEOROLOGICAL EYES WILL BE WATCHING WHAT TRANSPIRES UPSTREAM AS NCEP MODEL SUITE AND INTERNATIONAL GUIDANCE ARE BECOMING MORE IN AGREEMENT WITH AN ANOMALOUS DIGGING/PHASING TROUGH ACROSS THE MID WEST WITH EXPANDING AREA OF CLOUDS AND RAIN/SHOWERS. CLOUD COVERAGE MAY APPROACHING OUR SOUTHERN MOST ZONES OVERNIGHT BUT IT WILL REMAIN DRY. OVERNIGHT LOWS MAINLY INTO THE 50S WITH SOME UPPER 40S ACROSS PORTIONS OF THE DACKS...BERKS...SOUTHERN GREENS. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... IMPRESSIVE STORM TO DEVELOP ACROSS THE OHIO VALLEY AND IMPACT OUR REGION THIS WEEKEND... THE PREVIOUS EXCELLENT AFD FOLLOWS WITH MINOR UPDATES PER THE 00Z GUIDANCE. SATURDAY...THE 26/00Z ECMWF SHOWS THE SFC WAVE MOVING A LITTLE SLOWER TOWARDS A MID LEVEL JET CONFLUENT REGION OVER E-OH AND W-PA BY MID MORNING. THE ISENTROPIC LIFT INCREASES QUICKLY ON THE 290-300K SFC BY THE LATE MORNING INTO THE AFTERNOON ESPECIALLY SOUTH AND WEST OF THE CAPITAL REGION. THE LOW-LEVEL BAROCLINIC LEAFLET STRENGTHENS BETWEEN THE RETREATING AND STRENGTHENING HIGH OFF THE NEW ENGLAND COAST /1022MB/ ...AND THE LOW PRESSURE SYSTEM MOVING TOWARDS LAKE ERIE AND WRN PA BY THE EARLY PM WITH SUB 1000MB EXPECTED. THE GFS/ECMWF ATTEMPT TO HAVE A SECONDARY LOW FORM OVER THE MID ATLANTIC REGION THROUGH THE AFTERNOON. OVER RUNNING RAINFALL AHEAD OF THE PRIMARY SFC CYCLONE...AND THE WARM FRONT SHOULD OVER SPREAD THE REGION BY THE EARLY EVENING. AN ANOMALOUS H850/925 E/SE LLJ INCREASES AHEAD OF THE SFC WAVE TO BETTER THAN 40KTS. THE LATEST GFS/ECMWF HAVE E/SE WINDS OF 45-55KTS OVER THE FCST AREA BY 8 PM SAT. PLENTY OF ATLANTIC MOISTURE ENTRAINMENT SHOULD BE ADVECTED INTO THE REGION FOR PERIODS OF MDT-HVY RAIN BY SAT EVENING. HIGHS WILL BE BELOW NORMAL WITH MID AND U60S COMMON IN THE LOWER ELEVATIONS AND M50S TO L60S OVER THE HIGHER TERRAIN ACROSS THE CATSKILLS. SATURDAY NIGHT...THIS WILL BE THE HIGHEST POTENTIAL IMPACT PERIOD...AND WILL CONTINUE WHAT THE PREVIOUS SHIFT HIGHLIGHTED IN THE SEGMENTED HWO. THE GEFS INDICATE ANOMALOUS LLJ WITH U-WIND ANOMALIES 3 TO 5 STANDARD DEVIATIONS GREATER THAN NORMAL /STRONG EASTERLIES/ AND STRONG V-WIND ANOMALIES /STRONG SOUTHERLIES/ 3 TO 5 STANDARD DEVIATIONS GREATER THAN NORMAL. HENCE...A SE LOW-LEVEL JET MAX WILL FOCUS PERIODS OF MODERATE TO HEAVY RAINFALL. THE E/SE FLOW WILL ENHANCE THE RAINFALL ALONG THE SPINE OF THE ERN DACKS...ERN CATSKILLS...SRN GREENS..BERKS...AND NORTHERN LITCHFIELD HILLS. PWATS LOOK TO BE 1 TO 2 STD DEVS ABOVE NORMAL...SLIGHTLY HIGHER SOUTH AND EAST OF THE CAPITAL DISTRICT WHERE UP TO 3 STD IS CURRENT PROGGED. THERE IS A SMALL WINDOW WHERE THE E/SE WINDS MAY GUST CLOSE TO WIND ADVISORY LEVELS OVER THE SRN GREENS IN SRN VT...NRN TACONICS...AND POSSIBLY THE NRN BERKS. IT WILL DEPEND ON HOW MUCH MOMENTUM CAN BE TRANSFERRED TO SFC THROUGH A STRONG INVERSION IN THE SOUNDINGS AND ITS OCCURRING NOCTURNALLY. WE WILL MENTION THE THREAT AND CONTINUE WHAT THE DAY SHIFT HAS IN THE HWO. IT IS HARD TO TELL HOW MUCH OF A THREAT THE RAIN WILL HAVE FOR FLOODING AT THIS TIME. 1 TO 3 INCHES LOOKS POSSIBLE SAT PM INTO SUNDAY MORNING BASED ON THE EC/WPC/CAN GGEM GUIDANCE...WITH THE MESOSCALE MODELS SHOWING SOME 3-4 INCH AMOUNTS IN THE ERN CATSKILLS...AND ERN DACKS. PER EXTENSIVE COLLABORATION FROM SURROUNDING WFOS...CONFIDENCE REMAINS LOW FOR A FLOOD WATCH AT THIS TIME...BUT WILL CONTINUE TO MONITOR AND MENTION IN THE HWO. ZONE FFG VALUES REMAIN HIGH IN THE 3/6-HR TIME FRAME. CATEGORICAL POPS WERE CONTINUED WITH RAIN...HVY AT TIMES...SATURDAY NIGHT. IN ADDITION...SHOWALTER VALUES ARE PROGGED EVEN LOWER WITH SUB ZERO VALUES ADVECTING INTO THE REGION TO WARRANT AN INCLUSION OF THUNDERSTORMS OVERNIGHT. LOWS WILL BE MAINLY IN THE 50S. SUNDAY...MODEL TRENDS NOW WANT TO ADVECT IN A DRY SLOT DURING THE DAY WHICH WILL REDUCE THE PRECIP COVERAGE AND INTENSITY ACROSS MOST OF THE REGION FOR A SMALL WINDOW OF TIME. QUESTION IS IF WE ARE ABLE TO SEE SOME INSOLATION TO ASSIST WITH DESTABILIZATION. WHILE THE MAIN THRUST OF ADVECTION WILL BE WELL TO OUR NORTH...THE VERTICALLY STACKED LOW ACROSS WESTERN NY WITH SECONDARY LOW POSSIBLY TRACKING NORTH...NARROW LINES OF CONVECTION COULD EVOLVE. WE WILL FOLLOW A BLENDED MOS VALUES WHICH REQUIRES A SLIGHT ADJUSTMENT UPWARD IN THE AFTERNOON HIGH TEMPS TO LOWER HALF OF THE 70S FOR VALLEY LOCATIONS AND 60S ELSEWHERE. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE LARGE VERTICALLY STACKED STORM SYSTEM IMPACTING THE REGION WILL FINALLY START TO MOVE AWAY ON SUNDAY NIGHT...AS BOTH THE SFC AND UPPER LEVEL LOWS MOVE FROM UPSTATE NY TOWARDS SOUTHERN QUEBEC AND NORTHERN NEW ENGLAND. AS A RESULT...CHANCES FOR RAIN SHOWERS WILL DECREASE THROUGH THE OVERNIGHT HOURS ON SUN NIGHT...ALTHOUGH WITH CYCLONIC FLOW STILL IN PLACE...A FEW LIGHT RAIN SHOWERS AND PLENTY OF CLOUDS REMAIN POSSIBLE. MIN TEMPS LOOK TO FALL INTO THE MID 50S FOR MOST PLACES. BY MONDAY...WEAK RIDGING ALOFT WILL POKE INTO THE REGION...ALLOWING FOR PARTIAL SUNSHINE. CANNOT TOTALLY RULE OUT A BRIEF SHOWER...ESP EARLY IN THE DAY...ACROSS THE ADIRONDACKS OR SRN GREENS...BUT MOST AREAS LOOK TO STAY DRY. MAX TEMPS SHOULD REACH INTO THE MIDDLE TO UPPER 70S FOR VALLEY AREAS...WITH 60S FOR THE HIGH TERRAIN. DRY WEATHER LOOKS TO CONTINUE INTO MONDAY NIGHT WITH LOWS IN THE 50S ONCE AGAIN. WITHIN THE FLOW AT 500 HPA...ANOTHER SHORTWAVE TROUGH WILL ROTATE TOWARDS THE REGION FROM THE GREAT LAKES. COMBINED WITH A MOIST SOUTHERLY FLOW AND DAYTIME HEATING...A FEW ROUNDS OF SHOWERS AND THUNDERSTORMS CAN BE EXPECTED FOR TUESDAY...ESP DURING THE AFTN AND EVENING. CAN/T RULE OUT A FEW STRONG STORMS...ALTHOUGH WILL ULTIMATELY DEPEND ON HOW MUCH INSTABILITY WILL BE IN PLACE. MAX TEMPS LOOK TO REACH CLOSE TO 80 IN MANY VALLEY AREAS. SHOWERS AND THUNDERSTORMS WILL WIND DOWN ON TUESDAY EVENING WITH THE LOSS OF DAYTIME HEATING AND AS THE BEST UPPER LEVEL FORCING SHIFT EASTWARD. HOWEVER...MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON WEDNESDAY WITH THE BROAD UPPER LEVEL TROUGH REMAINING OVER THE AREA AND ANOTHER SHORTWAVE ROTATING BY CLOSE TO THE REGION. TEMPS ONCE AGAIN LOOK TO REACH THE UPPER 70S TO NEAR 80. DRIER WEATHER LOOKS TO RETURN FOR THE LATE WEEK PERIOD...ALTHOUGH THIS WILL BE DETERMINED BY JUST WHEN THE FLOW AT 500 HPA CAN FLATTEN OUT. WILL CONTINUE SLIGHT TO LOW CHC POPS FOR THURSDAY DUE TO THE UNCERTAINTY...WITH TEMPS MAINLY IN THE UPPER 70S. && .AVIATION /18Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS THROUGH THE FIRST 24 HOURS...EXCEPT PERHAPS MVFR LAST COUPLE OF HOURS AT KPOU AS -RA MOVES IN TO LOWER VSBYS...PART OF LOW PRESSURE DEEPENING OVER THE OHIO VALLEY AND HEADING EAST. THINGS LOOK MUCH WORSE JUST BEYOND 24 HOURS...WITH MOISTURE AND INSTABILITY INCREASING. ONLY SUB-MARGINAL SHEAR AT KPOU TOWARD 18Z SAT. SFC WINDS SHOULD REMAIN UNDER 10 KTS AT ALL AIRPORTS. OUTLOOK... SATURDAY NIGHT: HIGH OPERATIONAL IMPACT. BREEZY DEFINITE RA...TSRA. SUNDAY: HIGH OPERATIONAL IMPACT. BREEZY DEFINITE SHRA...TSRA. SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. BREEZY CHANCE OF SHRA. MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. && .FIRE WEATHER... MINIMAL TO LOW FIRE WEATHER RELATED CONCERNS THROUGH THE WEEKEND AS ISOLATED TO SCATTERED SHOWERS PERSIST INTO THIS MORNING. A BRIEF PERIOD OF DRY WEATHER IS EXPECTED LATER THIS AFTERNOON INTO EARLY SATURDAY MORNING BEFORE A WIDESPREAD...SOAKING RAINFALL OCCURS FOR THE MAJORITY OF THE REGION SATURDAY AFTERNOON INTO SUNDAY MORNING. THE RH VALUES WILL LOWER TO 40 TO 60 PERCENT TODAY WITH THE LOWER VALUES NORTH OF THE MOHAWK RIVER VALLEY. THE RH VALUES WILL HAVE AN EXCELLENT RECOVERY SATURDAY MORNING IN THE 75 TO 100 PERCENT RANGE AND REMAIN HIGH THROUGH THE DAY AS WET WEATHER SPREADS ACROSS THE ENTIRE REGION. THE WINDS WILL LIGHT FROM THE NORTH TO NORTHWEST AT AROUND 10 MPH TODAY...BECOMING LIGHT AND VARIABLE TO CALM WINDS FRIDAY NIGHT. && .HYDROLOGY... LIGHT RAIN SHOWERS WILL IMPACT MANY PORTIONS OF THE FORECAST AREA THROUGH THIS MORNING WITH RAINFALL AMOUNTS GENERALLY ONE TENTH OF AN INCH OR LESS. DRIER WEATHER IS EXPECTED LATE THIS AFTERNOON INTO SATURDAY MORNING BEFORE A STRONG LOW PRESSURE SYSTEM DEVELOPS NEAR THE OHIO VALLEY AND MOVES TOWARDS THE EASTERN GREAT LAKES REGION. PERIODS OF MODERATE TO HEAVY RAINFALL ARE POSSIBLE LATE SATURDAY AFTERNOON INTO SUNDAY...DEPENDING ON THE EVENTUAL TRACK AND EVOLUTION OF LOW PRESSURE DEVELOPING ACROSS THE OHIO VALLEY REGION. RIGHT NOW...ONE TO UP TO TWO INCHES OF RAINFALL ARE POSSIBLE ACROSS THE HSA WITH UP TO 3 INCHES OR SO OVER THE EASTERN CATSKILLS...AND POSSIBLE THE EASTERN ADIRONDACKS. THE TRACK AND RAINFALL DURATION WILL DETERMINE WHERE THE HIGHER AMOUNTS WILL OCCUR. THE LATEST MMEFS GUIDANCE CONTINUES TO SUGGEST WITHIN BANK RISES TO THE CAUTION OR ALERT STAGES AT A FEW SITES AT THIS TIME. URBAN AND SMALL STREAM CONCERNS ACROSS THE HSA WILL HAVE TO BE MONITORED...AND WILL MENTION IN THE HWO. ALSO...IF CONFIDENCE INCREASES FOR THE POTENTIAL OF WIDESPREAD MINOR FLOODING...THEN A FLOOD WATCH MAY BE NEEDED FOR PORTIONS OF THE HSA LATER IN TIME. 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...NONE. VT...NONE. && $$ SYNOPSIS...BGM/WASULA NEAR TERM...BGM/WASULA SHORT TERM...BGM/WASULA LONG TERM...FRUGIS AVIATION...ELH FIRE WEATHER...BGM/WASULA HYDROLOGY...BGM/WASULA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
525 PM EDT FRI JUN 26 2015 .SYNOPSIS... THUNDERSTORMS WILL BE SCATTERED WELL AHEAD OF A COLD FRONT THROUGH TONIGHT. THUNDERSTORM COVERAGE WILL INCREASE FOR SATURDAY AS THE FRONT GETS CLOSER TO THE AREA. THE FRONT WILL CROSS THE AREA SATURDAY NIGHT WITH DRY CONDITIONS AND TEMPERATURES NEAR NORMAL ARRIVING EARLY NEXT WEEK. && .NEAR TERM /TONIGHT/... CONVERGENCE INTO THE HEAT TROUGH OVER THE AREA AND OUTFLOW BOUNDARIES FROM PREVIOUS CONVECTION WILL RESULT IN ISOLATED TO SCATTERED THUNDERSTORMS. SOMEWHAT SHALLOW MOISTURE ASSOCIATED WITH THE UPPER-RIDGING SHOULD HELP TO LIMIT COVERAGE. DAMAGING WIND AND HAIL WILL BE A THREAT WITH THE THUNDERSTORMS THIS AFTERNOON AND EVENING. THE THREAT OF THUNDERSTORMS WILL CONTINUE TONIGHT MAINLY BECAUSE OF OUTFLOW BOUNDARY INTERACTION EARLY...ALONG WITH UPPER-LEVEL LIFT LATE AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. KEPT CHANCE POPS THROUGH THE NIGHT. THE TEMPERATURE GUIDANCE WAS CLOSE TONIGHT WITH LOWS IN THE MID AND UPPER 70S. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... A COLD FRONT WILL BE OFF TO THE WEST OF THE AREA THROUGH MUCH OF THE DAY SATURDAY. PW VALUES WILL BE AROUND 2.0 SO LOCALLY HEAVY RAINS WILL BE ASSOCIATED WITH THUNDERSTORMS. HIGHS WILL BE NEAR NORMAL SATURDAY WITH THE MERCURY RANGING FROM 90 TO 95 DEGREES. COLD FRONT WILL PUSH THROUGH THE AREA SATURDAY NIGHT. EXPECT WIDESPREAD CONVECTION AS UPPER LEVEL SUPPORT VIA A SERIES OF SHORT WAVES AND INCREASED INSTABILITY. SATURDAY NIGHT LOWS WILL RANGE FROM THE MID 60S WEST TO LOWER 70S EAST AS CONVECTION COMES TO AN END BEHIND THE COLD FRONT. && .LONG TERM /SUNDAY THROUGH FRIDAY/... MODELS CONTINUE TO BE IN GOOD AGREEMENT KEEPING THE UPPER LEVEL TROUGH ACROSS THE EASTERN STATES SUNDAY THEN SHIFTING OFF THE COAST BY THE MIDDLE OF NEXT WEEK. SURFACE HIGH PRESSURE WILL USHER IN DRIER MORE STABLE AIR BEGINNING SUNDAY AND CONTINUING THROUGH MONDAY. INCREASING MOISTURE AND INSTABILITY TUESDAY THROUGH THURSDAY WILL INCREASE THE CHANCE FOR AFTERNOON/EVENING CONVECTION. HIGHS WILL BE IN THE UPPER 80S SUNDAY...AROUND 90 MONDAY...AND 90 TO 95 TUESDAY THROUGH THURSDAY. && .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... VFR CONDITIONS ARE EXPECTED FOR MUCH OF THE TAF PERIOD...BUT THERE WILL BE A THREAT OF THUNDERSTORMS. SUPPORT FOR THUNDERSTORMS WILL BE MAINLY CONVERGENCE INTO A HEAT TROUGH AND POSSIBLE OUTFLOW BOUNDARIES FROM PREVIOUS CONVECTION. SOMEWHAT SHALLOW MOISTURE ASSOCIATED WITH THE UPPER-RIDGING SHOULD LIMIT COVERAGE. THE HRRR AND ARW DISPLAY ISOLATED TO SCATTERED COVERAGE. THE SPC WRF HAS THE GREATEST THUNDERSTORM COVERAGE AROUND 800 PM. A THREAT OF THUNDERSTORMS WILL CONTINUE TONIGHT MAINLY BECAUSE OF OUTFLOW BOUNDARY INTERACTION EARLY. THE MODELS ALSO INDICATE UPPER-LEVEL LIFT LATE AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. THERE WILL BE A THUNDERSTORM CHANCE THROUGH THE NIGHT DESPITE NOCTURNAL COOLING. UNCERTAINTY WAS TOO HIGH TO FORECAST THUNDERSTORMS EXPLICITLY IN THE TAFS AT ISSUANCE TIME...BUT WE DID INCLUDE A VICINITY MENTION DURING THE MORE LIKELY TIME OF CONVECTION. THE THREAT OF FOG IS LOW OVERNIGHT BECAUSE OF CONTINUED INSTABILITY AND LOW-LEVEL WINDS. EXTENDED AVIATION OUTLOOK...WIDESPREAD RESTRICTIONS IN SHOWERS AND THUNDERSTORMS MAY OCCUR SATURDAY EVENING AND SATURDAY NIGHT ASSOCIATED WITH A COLD FRONT MOVING INTO THE AREA. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
208 PM EDT FRI JUN 26 2015 .SYNOPSIS... THUNDERSTORMS WILL BE SCATTERED WELL AHEAD OF A COLD FRONT THROUGH TONIGHT. THUNDERSTORM COVERAGE WILL INCREASE FOR SATURDAY AS THE FRONT GETS CLOSER TO THE AREA. THE FRONT WILL CROSS THE AREA SATURDAY NIGHT WITH DRY CONDITIONS AND TEMPERATURES NEAR NORMAL ARRIVING EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... IT IS ANOTHER HOT AFTERNOON. UPPER-LEVEL RIDGING OVER THE FORECAST AREA HAS HELPED PUSH TEMPERATURES TO AROUND 100 WITH HEAT INDEX VALUES NEAR 105. CONVERGENCE INTO THE HEAT TROUGH OVER THE AREA AND OUTFLOW BOUNDARIES FROM PREVIOUS CONVECTION WILL RESULT IN THUNDERSTORMS. SOMEWHAT SHALLOW MOISTURE ASSOCIATED WITH THE UPPER-RIDGING SHOULD LIMIT COVERAGE. THE HRRR AND ARW DISPLAY ISOLATED TO SCATTERED COVERAGE. THE SPC WRF HAS THE GREATEST THUNDERSTORM COVERAGE AROUND 800 PM. A THREAT OF THUNDERSTORMS WILL CONTINUE TONIGHT MAINLY BECAUSE OF OUTFLOW BOUNDARY INTERACTION EARLY. THE MODELS ALSO INDICATE UPPER-LEVEL LIFT LATE AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. WE KEPT CHANCE POPS THROUGH THE NIGHT. STRONG INSTABILITY HAS DEVELOPED. MIXED-LAYER CAPE WAS ABOVE 3000 J/KG OVER PART OF THE FORECAST AREA EARLY THIS AFTERNOON. THE LATEST LAPS SOUNDINGS HAD CONSIDERABLE CAPE IN THE HAIL GROWTH AREA. DAMAGING WIND AND HAIL WILL BE A THREAT WITH THE THUNDERSTORMS THIS AFTERNOON AND EVENING. THE TEMPERATURE GUIDANCE WAS CLOSE TONIGHT WITH LOWS IN THE MID AND UPPER 70S. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... COLD FRONT WILL PUSH THROUGH THE AREA SATURDAY NIGHT. EXPECT WIDESPREAD CONVECTION AS UPPER LEVEL SUPPORT VIA A SERIES OF SHORT WAVES AND INCREASED INSTABILITY. PW VALUES WILL BE AROUND 2.O SO LOCALLY HEAVY RAINS WILL BE ASSOCIATED WITH THUNDERSTORMS. HIGHS WILL BE NEAR NORMAL SATURDAY WITH THE MERCURY RANGING FROM 90 TO 95 DEGREES. SATURDAY NIGHT LOWS WILL RANGE FROM THE MID 60S WEST TO LOWER 70S EAST AS CONVECTION COMES TO AN END BEHIND THE COLD FRONT. && .LONG TERM /SUNDAY THROUGH THURSDAY/... MODELS CONTINUE TO BE IN GOOD AGREEMENT KEEPING THE UPPER LEVEL TROUGH ACROSS THE EASTERN STATES SUNDAY THEN SHIFTING OFF THE COAST BY THE MIDDLE OF NEXT WEEK. SURFACE HIGH PRESSURE WILL USHER IN DRIER MORE STABLE AIR BEGINNING SUNDAY AND CONTINUING THROUGH MONDAY. INCREASING MOISTURE AND INSTABILITY TUESDAY THROUGH THURSDAY WILL INCREASE THE CHANCE FOR AFTERNOON/EVENING CONVECTION. HIGHS WILL BE IN THE UPPER 80S SUNDAY...AROUND 90 MONDAY...AND 90 TO 95 TUESDAY THROUGH THURSDAY. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... VFR CONDITIONS ARE EXPECTED FOR MUCH OF THE TAF PERIOD...BUT THERE WILL BE A THREAT OF THUNDERSTORMS. SUPPORT FOR THUNDERSTORMS WILL BE MAINLY CONVERGENCE INTO A HEAT TROUGH AND POSSIBLE OUTFLOW BOUNDARIES FROM PREVIOUS CONVECTION. SOMEWHAT SHALLOW MOISTURE ASSOCIATED WITH THE UPPER-RIDGING SHOULD LIMIT COVERAGE. THE HRRR AND ARW DISPLAY ISOLATED TO SCATTERED COVERAGE. THE SPC WRF HAS THE GREATEST THUNDERSTORM COVERAGE AROUND 800 PM. A THREAT OF THUNDERSTORMS WILL CONTINUE TONIGHT MAINLY BECAUSE OF OUTFLOW BOUNDARY INTERACTION EARLY. THE MODELS ALSO INDICATE UPPER-LEVEL LIFT LATE AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. THERE WILL BE A THUNDERSTORM CHANCE THROUGH THE NIGHT DESPITE NOCTURNAL COOLING. UNCERTAINTY WAS TOO HIGH TO FORECAST THUNDERSTORMS EXPLICITLY IN THE TAFS AT ISSUANCE TIME...BUT WE DID INCLUDE A VICINITY MENTION DURING THE MORE LIKELY TIME OF CONVECTION. STRONG INSTABILITY WITH CONSIDERABLE CAPE IN THE HAIL GROWTH AREA INDICATES A THREAT OF STRONG WIND AND HAIL WITH ANY THUNDERSTORMS THIS AFTERNOON INTO THE EVENING. OTHER THAN IN SHOWERS...THE THREAT OF FOG IS LOW OVERNIGHT BECAUSE OF CONTINUED INSTABILITY. EXTENDED AVIATION OUTLOOK...WIDESPREAD RESTRICTIONS IN SHOWERS AND THUNDERSTORMS MAY OCCUR SATURDAY AND SATURDAY NIGHT ASSOCIATED WITH A COLD FRONT MOVING INTO THE AREA. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1238 PM EDT FRI JUN 26 2015 .SYNOPSIS... THUNDERSTORMS WILL BE SCATTERED WELL AHEAD OF A COLD FRONT THROUGH TONIGHT. THUNDERSTORM COVERAGE WILL INCREASE FOR SATURDAY AS THE FRONT GETS CLOSER TO THE AREA. THE FRONT WILL CROSS THE AREA SATURDAY NIGHT WITH DRY CONDITIONS AND TEMPERATURES NEAR NORMAL ARRIVING EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... IT IS ANOTHER HOT AFTERNOON. UPPER-LEVEL RIDGING OVER THE FORECAST AREA HAS HELPED PUSH TEMPERATURES TO AROUND 100. CONVERGENCE INTO THE HEAT TROUGH OVER THE AREA AND OUTFLOW BOUNDARIES FROM PREVIOUS CONVECTION...MAINLY IN THE NORTH PART WILL RESULT IN THUNDERSTORMS. SOMEWHAT SHALLOW MOISTURE ASSOCIATED WITH THE UPPER-RIDGING SHOULD LIMIT COVERAGE. THE HRRR AND ARW DISPLAY ISOLATED TO SCATTERED COVERAGE MAINLY IN THE NORTH PART. THE SPC WRF HAS THE GREATEST THUNDERSTORM COVERAGE AROUND 800 PM. A THREAT OF THUNDERSTORMS WILL CONTINUE TONIGHT MAINLY BECAUSE OF OUTFLOW BOUNDARY INTERACTION EARLY. THE MODELS ALSO INDICATE UPPER-LEVEL LIFT LATE AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. WE KEPT CHANCE POPS THROUGH THE NIGHT. STRONG INSTABILITY HAS DEVELOPED. MIXED-LAYER CAPE WAS ABOVE 3000 J/KG OVER PART OF THE FORECAST AREA EARLY THIS AFTERNOON. THE LATEST LAPS SOUNDING HAD CONSIDERABLE CAPE IN THE HAIL GROWTH AREA. DAMAGING WIND AND HAIL WILL BE A THREAT WITH THE THUNDERSTORMS THIS AFTERNOON AND EVENING. THE TEMPERATURE GUIDANCE WAS CLOSE TONIGHT WITH LOWS IN THE MID AND UPPER 70S. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... COLD FRONT WILL PUSH THROUGH THE AREA SATURDAY NIGHT. EXPECT WIDESPREAD CONVECTION AS UPPER LEVEL SUPPORT VIA A SERIES OF SHORT WAVES AND INCREASED INSTABILITY. PW VALUES WILL BE AROUND 2.O SO LOCALLY HEAVY RAINS WILL BE ASSOCIATED WITH THUNDERSTORMS. HIGHS WILL BE NEAR NORMAL SATURDAY WITH THE MERCURY RANGING FROM 90 TO 95 DEGREES. SATURDAY NIGHT LOWS WILL RANGE FROM THE MID 60S WEST TO LOWER 70S EAST AS CONVECTION COMES TO AN END BEHIND THE COLD FRONT. && .LONG TERM /SUNDAY THROUGH THURSDAY/... MODELS CONTINUE TO BE IN GOOD AGREEMENT KEEPING THE UPPER LEVEL TROUGH ACROSS THE EASTERN STATES SUNDAY THEN SHIFTING OFF THE COAST BY THE MIDDLE OF NEXT WEEK. SURFACE HIGH PRESSURE WILL USHER IN DRIER MORE STABLE AIR BEGINNING SUNDAY AND CONTINUING THROUGH MONDAY. INCREASING MOISTURE AND INSTABILITY TUESDAY THROUGH THURSDAY WILL INCREASE THE CHANCE FOR AFTERNOON/EVENING CONVECTION. HIGHS WILL BE IN THE UPPER 80S SUNDAY...AROUND 90 MONDAY...AND 90 TO 95 TUESDAY THROUGH THURSDAY. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... VFR CONDITIONS ARE EXPECTED FOR MUCH OF THE TAF PERIOD...BUT THERE WILL BE A THREAT OF THUNDERSTORMS. SUPPORT FOR THUNDERSTORMS WILL BE MAINLY CONVERGENCE INTO A HEAT TROUGH AND POSSIBLE OUTFLOW BOUNDARIES FROM PREVIOUS CONVECTION. SOMEWHAT SHALLOW MOISTURE ASSOCIATED WITH THE UPPER-RIDGING SHOULD LIMIT COVERAGE. THE HRRR AND ARW DISPLAY ISOLATED TO SCATTERED COVERAGE. THE SPC WRF HAS THE GREATEST THUNDERSTORM COVERAGE AROUND 800 PM. A THREAT OF THUNDERSTORMS WILL CONTINUE TONIGHT MAINLY BECAUSE OF OUTFLOW BOUNDARY INTERACTION EARLY. THE MODELS ALSO INDICATE UPPER-LEVEL LIFT LATE AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. THERE WILL BE A THUNDERSTORM CHANCE THROUGH THE NIGHT DESPITE NOCTURNAL COOLING. UNCERTAINTY WAS TOO HIGH TO FORECAST THUNDERSTORMS EXPLICITLY IN THE TAFS AT ISSUANCE TIME...BUT WE DID INCLUDE A VICINITY MENTION DURING THE MORE LIKELY TIME OF CONVECTION. STRONG INSTABILITY WITH CONSIDERABLE CAPE IN THE HAIL GROWTH AREA INDICATES A THREAT OF STRONG WIND AND HAIL WITH ANY THUNDERSTORMS THIS AFTERNOON INTO THE EVENING. OTHER THAN IN SHOWERS...THE THREAT OF FOG IS LOW OVERNIGHT BECAUSE OF CONTINUED INSTABILITY. EXTENDED AVIATION OUTLOOK...WIDESPREAD RESTRICTIONS IN SHOWERS AND THUNDERSTORMS MAY OCCUR SATURDAY AND SATURDAY NIGHT ASSOCIATED WITH A COLD FRONT MOVING INTO THE AREA. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1231 PM EDT FRI JUN 26 2015 .SYNOPSIS...THUNDERSTORMS WILL BE SCATTERED WELL AHEAD OF A COLD FRONT THROUGH TONIGHT. THUNDERSTORM COVERAGE WILL INCREASE FOR SATURDAY AS THE FRONT GETS CLOSER TO THE AREA. THE FRONT WILL CROSS THE AREA SATURDAY NIGHT WITH DRY CONDITIONS AND TEMPERATURES NEAR NORMAL ARRIVING EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... IT IS ANOTHER HOT AFTERNOON. UPPER-LEVEL RIDGING OVER THE FORECAST AREA HAS HELPED PUSH TEMPERATURES TO AROUND 100. CONVERGENCE INTO THE HEAT TROUGH OVER THE AREA AND OUTFLOW BOUNDARIES FROM PREVIOUS CONVECTION...MAINLY IN THE NORTH PART WILL RESULT IN THUNDERSTORMS. SOMEWHAT SHALLOW MOISTURE ASSOCIATED WITH THE UPPER-RIDGING SHOULD LIMIT COVERAGE. THE HRRR AND ARW DISPLAY ISOLATED TO SCATTERED COVERAGE MAINLY IN THE NORTH PART. THE SPC WRF HAS THE GREATEST THUNDERSTORM COVERAGE AROUND 800 PM. A THREAT OF THUNDERSTORMS WILL CONTINUE TONIGHT MAINLY BECAUSE OF OUTFLOW BOUNDARY INTERACTION EARLY. THE MODELS ALSO INDICATE UPPER-LEVEL LIFT LATE AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. WE KEPT CHANCE POPS THROUGH THE NIGHT. STRONG INSTABILITY HAS DEVELOPED. MIXED-LAYER CAPE WAS ABOVE 3000 J/KG OVER PART OF THE FORECAST AREA EARLY THIS AFTERNOON. THE LATEST LAPS SOUNDING HAD CONSIDERABLE CAPE IN THE HAIL GROWTH AREA. DAMAGING WIND AND HAIL WILL BE A THREAT WITH THE THUNDERSTORMS THIS AFTERNOON AND EVENING. THE TEMPERATURE GUIDANCE WAS CLOSE TONIGHT WITH LOWS IN THE MID AND UPPER 70S. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... AS THE UPPER TROUGH DEEPENS OVER THE EASTERN STATES...A SURFACE LOW PRESSURE SYSTEM WILL CROSS THE UPPER MISSISSIPPI RIVER VALLEY TO THE GREAT LAKES REGION. ITS ASSOCIATED COLD FRONT WILL CROSS OUR AREA SATURDAY NIGHT. EXPECT WIDESPREAD CONVECTION SATURDAY AS A COUPLE OF SHORT WAVES MOVE THROUGH AND INSTABILITY INCREASES. PW VALUES WILL BE AROUND 2.O SO LOCALLY HEAVY RAINS WILL BE ASSOCIATED WITH THUNDERSTORMS. KEPT HIGHS IN THE UPPER 80S AND LOWER 90S ON SATURDAY...WHICH ARE A FEW DEGREES BELOW GUIDANCE CONSENSUS...GIVEN CLOUDS AND PRECIP. LOWS SATURDAY NIGHT ARE EXPECTED TO RANGE FROM THE MID 60S WEST TO LOWER 70S EAST AS CONVECTION COMES TO AN END BEHIND THE COLD FRONT. && .LONG TERM /SUNDAY THROUGH THURSDAY/... GFS AND ECMWF IN GOOD AGREEMENT KEEPING THE UPPER LEVEL TROUGH ACROSS THE EASTERN STATES SUNDAY THEN SHIFTING OFF THE COAST BY THE MIDDLE OF NEXT WEEK. SURFACE HIGH PRESSURE WILL USHER IN DRIER MORE STABLE AIR BEGINNING SUNDAY AND CONTINUING THROUGH MONDAY. MOISTURE AND INSTABILITY BEGIN TO INCREASE AGAIN TUESDAY AND WEDNESDAY. HIGHS IN THE UPPER 80S SUNDAY...AROUND 90 MONDAY...AND 90 TO 95 TUESDAY AND WEDNESDAY. && .AVIATION /16Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS ARE EXPECTED FOR MUCH OF THE TAF PERIOD...BUT THERE WILL BE A THREAT OF THUNDERSTORMS. SUPPORT FOR THUNDERSTORMS WILL BE MAINLY CONVERGENCE INTO A HEAT TROUGH AND POSSIBLE OUTFLOW BOUNDARIES FROM PREVIOUS CONVECTION. SOMEWHAT SHALLOW MOISTURE ASSOCIATED WITH THE UPPER-RIDGING SHOULD LIMIT COVERAGE. THE HRRR AND ARW DISPLAY ISOLATED TO SCATTERED COVERAGE. THE SPC WRF HAS THE GREATEST THUNDERSTORM COVERAGE AROUND 800 PM. A THREAT OF THUNDERSTORMS WILL CONTINUE TONIGHT MAINLY BECAUSE OF OUTFLOW BOUNDARY INTERACTION EARLY. THE MODELS ALSO INDICATE UPPER-LEVEL LIFT LATE AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. THERE WILL BE A THUNDERSTORM CHANCE THROUGH THE NIGHT DESPITE NOCTURNAL COOLING. UNCERTAINTY WAS TOO HIGH TO FORECAST THUNDERSTORMS EXPLICITLY IN THE TAFS AT ISSUANCE TIME...BUT WE DID INCLUDE A VICINITY MENTION DURING THE MORE LIKELY TIME OF CONVECTION. STRONG INSTABILITY WITH CONSIDERABLE CAPE IN THE HAIL GROWTH AREA INDICATES A THREAT OF STRONG WIND AND HAIL WITH ANY THUNDERSTORMS THIS AFTERNOON INTO THE EVENING. OTHER THAN IN SHOWERS...THE THREAT OF FOG IS LOW OVERNIGHT BECAUSE OF CONTINUED INSTABILITY. EXTENDED AVIATION OUTLOOK...WIDESPREAD RESTRICTIONS IN SHOWERS AND THUNDERSTORMS MAY OCCUR SATURDAY AND SATURDAY NIGHT ASSOCIATED WITH A COLD FRONT MOVING INTO THE AREA. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 99
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1259 PM CDT FRI JUN 26 2015 .UPDATE... ISSUED AT 1045 AM CDT FRI JUN 26 2015 WILL UPDATE THE FORECAST TO EXPAND THE FLASH FLOOD WATCH FURTHER NORTH THIS AFTERNOON AND INTO MID EVENING UNTIL 10 PM TO INCLUDE ALL OF OUR CWA EXCEPT FOR KNOX...STARK AND MARSHALL COUNTIES. SHOWERS AND THUNDERSTORMS HAVE SPREAD SLOWLY AS FAR NORTH AS PEORIA BY LATE MORNING WITH HEAVIEST RAINS OVER 1 INCH ALONG A LEWISTOWN TO PEKIN TO BLOOMINGTON TO DANVILLE LINE. A QUASI STATIONARY BOUNDARY WAS NEAR I-72 AND EXTENDED TO 1013 MB SURFACE LOW PRESSURE OVER NE MO BETWEEN KIRKSVILLE AND QUINCY. ANOTHER 1013 MB SURFACE LOW PRESSURE WAS OVER SOUTHEAST MO. HRRR MODEL HANDLING THIS CONVECTION WELL AND USED THIS MODEL FOR FORECAST THIS AFTERNOON AND EVENING. SURFACE LOW PRESSURE TO QUICKLY DEEPEN TO 1006 MB AS IT TRACKS TO NEAR TERRE HAUTE INDIANA BY SUNSET. HEAVIEST RAINS TO FALL ALONG AND NORTH OF THE LOW PRESSURE TRACK AND FRONTAL BOUNDARY NORTH OF I-70 WHERE ADDITIONAL 1 INCH OF RAIN EXPECTED WITH LOCALLY 1 TO 2 MORE INCHES OF RAIN POSSIBLE FROM I-72 NORTH. SPC ALSO HAS SLIGHT RISK OF SEVERE STORMS THIS AFTERNOON OVER FAR SE IL SE OF A OLNEY TO ROBINSON LINE FOR 15% RISK OF DAMAGING WIND GUSTS AND LARGE HAIL AND 2% RISK OF TORNADOES. ENHANCED SLIGHT RISK WAS SE OF LAWERNCE COUNTY AND CENTERED OVER KY AND MID/NW TN. HIGHS MOSTLY IN THE MID 70S OVER CENTRAL IL WITH LOWER 80S IN FAR SOUTHEAST IL AND HUMID WITH DEWPOINTS IN THE MID 60S TO LOWER 70S. && .SHORT TERM...(TODAY) ISSUED AT 305 AM CDT FRI JUN 26 2015 08Z/3AM SURFACE ANALYSIS SHOWS LOW PRESSURE NEAR KANSAS CITY...WITH STATIONARY FRONTAL BOUNDARY EXTENDING E/SE INTO FAR SOUTHERN ILLINOIS. MCS THAT IMPACTED THE SE KILX CWA EARLIER THIS EVENING HAS NOW TRACKED INTO CENTRAL/EASTERN KENTUCKY...WHILE A SECOND MCS HAS DEVELOPED UPSTREAM OVER EASTERN KANSAS INTO WEST-CENTRAL MISSOURI. THIS SECOND SYSTEM WILL CONTINUE TO TRACK E/SE ALONG THE SYNOPTIC FRONT/OUTFLOW FROM PREVIOUS COMPLEX INTO SOUTHERN ILLINOIS LATER THIS MORNING. FURTHER NORTH...STRATIFORM RAIN WITH A FEW EMBEDDED THUNDERSTORMS WILL SPREAD INTO CENTRAL ILLINOIS FROM THE WEST. DUE TO EXTENSIVE CLOUD COVER NORTH OF THE FRONT...WILL ONLY MENTION ISOLATED THUNDER ALONG/NORTH OF THE I-72 CORRIDOR. FURTHER SOUTH...WILL GO WITH PREDOMINANT THUNDER CLOSER TO THE BOUNDARY AND THE MORE UNSTABLE AIRMASS ALONG/SOUTH OF I-70. LATEST DAY 1 CONVECTIVE OUTLOOK PLACES THE FAR SOUTHEAST CWA IN A SLIGHT RISK FOR SEVERE...WITH DAMAGING WIND GUSTS AND LARGE HAIL BEING THE PRIMARY THREATS LATER TODAY. HEAVIEST RAINFALL WILL ALSO BE FOCUSED ACROSS THE SOUTHEAST WHERE 1 TO 1.5 INCHES WILL BE LIKELY. .LONG TERM...(TONIGHT THROUGH THURSDAY) ISSUED AT 305 AM CDT FRI JUN 26 2015 SHORT-WAVE TROUGH EVIDENT ON CURRENT WATER VAPOR IMAGERY OVER EASTERN NEBRASKA/KANSAS WILL TRACK EASTWARD INTO INDIANA TONIGHT. SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE ALONG/AHEAD OF THIS FEATURE THIS EVENING...WITH RAIN CHANCES DIMINISHING FROM WEST TO EAST AFTER MIDNIGHT. ONCE THE WAVE PASSES TO THE EAST AND THE PERSISTENT FRONTAL BOUNDARY DRAPED ACROSS SOUTHERN ILLINOIS GETS A GOOD PUSH SOUTHWARD...COOLER AND DRIER WEATHER WILL BE ON TAP FOR SATURDAY. EVEN WITH MOSTLY SUNNY SKIES...BRISK NORTHERLY FLOW WILL KEEP TEMPS SEVERAL DEGREES BELOW NORMAL FOR THIS TIME OF YEAR IN THE MIDDLE TO UPPER 70S. SYNOPTIC PATTERN THROUGHOUT THE EXTENDED WILL FEATURE A LARGE UPPER RIDGE OVER THE ROCKIES AND A CORRESPONDING DOWNSTREAM TROUGH ACROSS THE GREAT LAKES/MIDWEST. WITH THIS PATTERN REMAINING FIRMLY IN PLACE THROUGH NEXT WEEK...A CONTINUATION OF BELOW NORMAL TEMPERATURES IS ANTICIPATED ALONG WITH PERIODIC RAIN CHANCES. SEVERAL SHORT-WAVES WILL DROP INTO THE REGION WITHIN THE BROAD NORTHWESTERLY FLOW PATTERN...HOWEVER THE EXACT TIMING AND STRENGTH OF THESE FEATURES WILL BE DIFFICULT TO DETERMINE THIS FAR OUT. BASED ON GFS/ECMWF CONSENSUS...IT APPEARS TWO DISTINCT PERIODS OF ENHANCED RAIN CHANCES ARE EMERGING. ONE LATE SUNDAY INTO MONDAY AND ANOTHER LATE TUESDAY INTO WEDNESDAY. HAVE INCLUDED MENTIONABLE POPS DURING THOSE TIME FRAMES...THEN HAVE GONE WITH A DRY FORECAST THE REST OF THE TIME. NEITHER OF THESE TWO SYSTEMS WILL HAVE NEARLY AS MUCH MOISTURE TO WORK WITH AS RECENT SYSTEMS...SO DESPITE POPS...RAINFALL AMOUNTS WILL REMAIN LIGHT NEXT WEEK. MAIN STORY WILL THE UNSEASONABLY COOL CONDITIONS...WITH HIGHS IN THE UPPER 70S AND LOWER 80S THROUGH THE ENTIRE WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1255 PM CDT FRI JUN 26 2015 LARGE AREA OF SHOWERS AND ISOLATED THUNDERSTORMS OVER CENTRAL IL WILL BRING IFR TO MVFR VISIBILITIES AND CEILINGS THIS AFTERNOON AND GENERALLY LOWEST ALONG I-74 AIRPORTS OF PIA...BMI AND CMI WHERE CEILINGS AS LOW AS AROUND 500 FT. RAIN SHOWERS TO GRADUALLY DIMINISH FROM WEST TO EAST DURING MID/LATE EVENING AS 1012 MB LOW PRESSURE OVER NE MO DEEPENS TO 1005 MB AS IT TRACKS TO SOUTH CENTRAL INDIANA BY MIDNIGHT TONIGHT. MVFR CEILINGS TO CONTINUE TONIGHT INTO SAT MORNING AND COULD BE BELOW 1K FT OVER EASTERN TAF SITES TONIGHT. LOW CLOUDS SHOULD SCATTER OUT FROM NW TO SE BETWEEN 14-18Z SAT HAPPENING FIRST AT PIA AND LAST AT CMI. SSE WINDS NEAR 10 KTS OR LESS AT SPI AND DEC SHOULD VEER NE NEXT FEW HOURS AND NE WINDS TO INCREASE TO 10-15 KTS ACROSS CENTRAL IL LATER THE AFTERNOON AND EVENING. NE WINDS TO VEER NORTHERLY DURING TONIGHT INTO SAT MORNING AS LOW PRESSURE DEEPENS AND PULLS AWAY FROM IL. && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 10 PM CDT THIS EVENING FOR ILZ029-031- 036>038-040>057-061>063-066>068-071>073. && $$ UPDATE...07 SHORT TERM...BARNES LONG TERM...BARNES AVIATION...07
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
607 PM EDT FRI JUN 26 2015 .SYNOPSIS... UNSEASONABLY DEEP LOW PRESSURE WILL MOVE THROUGH THE REGION ON SATURDAY...WITH MUCH COLDER AND WINDY CONDITIONS TO END THE WEEKEND. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... NO MAJOR CHANGES WERE COMPLETED FOR THE EARLY EVE UPDATE ALTHOUGH THE THUNDER MENTION WAS REMOVED GIVEN A PROGGED LACK OF INSTABILITY. PREVIOUS... THE UPPER TROUGH OVER THE WESTERN GREAT LAKES WILL CONTINUE TO DEEPEN AS IT PIVOTS EASTWARD TOWARD THE OHIO VALLEY OVERNIGHT. THIS AND A COUPLED JET WILL HELP TO INTENSIFY THE SURFACE LOW AS IT MOVES TOWARD NORTHERN OHIO BY SATURDAY MORNING. TONIGHT...THE WARM FRONT WILL BE LIFTED ACROSS THE REGION. THE MODELS HAVE STRUGGLED TO RESOLVE THIS INITIAL PRECIPITATION WITH THE BOUNDARY...BUT SO FAR THE RUC AND THE HRRR HAVE HANDLED IT BEST...SO LOW CHANCE POPS WERE MAINTAIN AND THEN RAMPED UP AS THE LOW APPROACHES. OVERNIGHT...STRONG ISENTROPIC LIFT AND DEEP MOISTURE WILL PROVIDE FOR A PROLONGED PERIOD OF RAINFALL...AT LEAST UNTIL DRY AIR WRAPS INTO THE MID LEVELS OF THE OCCLUDING LOW LATER ON SATURDAY MORNING. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... RAIN WILL BE ONGOING AT THE START OF THIS PERIOD...WITH SURFACE LOW POSITIONED IN WESTERN OHIO. OVERALL SURFACE LOW PROGRESSION AND DEEPENING IS FORECAST TO SLOW AS THE MID LEVEL LOW CLOSES OVER NORTHEAST OHIO. THE MATURING SYSTEM IS THEN PROJECTED TO DRIFT NORTHEASTWARD THROUGH SUNDAY. TAIL END OF RAIN SHIELD WILL THUS PROGRESS NORTHEASTWARD WITH THE MID LEVEL DRY SLOT THROUGH THE MORNING. THE TIMING OF THAT FEATURE WITH WARM FRONT POSITIONING AND PROLONGED MOISTURE CONVERGENCE NORTH AND EAST OF THE MID LEVEL LOW WILL DETERMINE WHERE THE HEAVIEST RAINFALL OCCURS. AT MOMENT...AREAS NORTH OF PITTSBURGH...ESPECIALLY THOSE ALONG AND NORTH OF I-80...ARE PROJECTED FOR THE HIGHER TOTALS AROUND...AND IN EXCESS OF 2 INCHES. GIVEN THE RECENT WET PERIOD...THE COLLABORATED FLOOD WATCH HAS BEEN CONTINUED WITH A GENERAL 1 TO 2 INCHES ANTICIPATED ELSEWHERE. THERE IS AN INTERESTING CONDITIONAL COMPONENT TO THE SATURDAY AFTERNOON/EVENING FORECAST. GIVEN THE STRENGTH AND CUTOFF NATURE OF THIS SYSTEM...DEEP LAYER SPEED AND DIRECTIONAL SHEAR WILL BE DANGEROUSLY HIGH...WHILE BOUNDARY LAYER VALUES ESCALATE IN VICINITY OF THE AFOREMENTIONED WARM FRONT. SHOULD SUFFICIENT DESTABILIZATION OCCUR UNDER THE ENCROACHING DRY SLOT...THEN THE POTENTIAL FOR SEVERE WEATHER WILL ESCALATE. NO ACTION WAS TAKEN JUST YET...BUT THIS POTENTIAL WILL BE CLOSELY MONITORED. PERIODIC SHOWER POTENTIAL AND COOLER TEMPERATURES CAN BE EXPECTED THEREAFTER AS AN AMPLIFIED GREAT LAKE-TO-GULF OF MEXICO UPPER TROUGH DEVELOPS FOR THE START OF THE NEW WEEK. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... LONGER RANGE MODEL GUIDANCE FAVORS DRASTICALLY INCREASED RIDGING IN THE WEST WITH DOWNSTREAM DEEPENING TROUGHING ACROSS THE GREAT LAKES. THIS WILL LIKELY KEEP THINGS FAIRLY ACTIVE AND WET OVER THE CWA...WITH TEMPERATURES LIKELY TO REMAIN A BIT BELOW NORMAL. MODEL TIMING OF INDIVIDUAL SHORT WAVES IS EXCEEDINGLY SUSPECT AT THIS JUNCTURE...HOWEVER MONDAY NIGHT INTO TUESDAY PROBABLY SEES THE BEST SHOT AT WIDESPREAD RAIN SHOWERS ACROSS THE AREA. FRIES && .AVIATION /22Z FRIDAY THROUGH WEDNESDAY/... WARM FRONT SHOULD SLOWLY LIFT ACROSS THE REGION OVERNIGHT. HAVE CONTINUED VCTS AT ZZV WITH THUNDERSTORMS CONTINUING ACROSS CENTRAL OHIO...BUT WITH AMOUNT OF CLOUD COVER ACROSS EASTERN OHIO INTO WESTERN PENNSYLVANIA...THINK THAT THUNDERSTORM COVERAGE SHOULD REMAIN CONTAINED TO CENTRAL WEST VIRGINIA. MAINLY MVFR CIG RESTRICTIONS ARE ANTICIPATED UNTIL THE LOW APPROACHES OVERNIGHT AND STRATIFORM RAINFALL APPROACHES AT WHICH POINT MOST SITES SHOULD EXPERIENCE A PERIOD OF IFR CIGS AND/OR VISIBILITY. CONDITIONS MAY IMPROVE TOWARD MORNING AS THE DRY SLOT APPROACHES. STARTED AN UPWARD TREND BUT DID NOT GO BACK TO VFR AT THIS TIME. THUNDERSTORMS MAY BE POSSIBLE TOMORROW AFTERNOON IF WE CAN SCATTER OUT THE CLOUDS IN THE DRY SLOT. .OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/... RESTRICTIONS ARE LIKELY THROUGH THE REST OF THE WEEKEND WITH PASSAGE OF A STRONG LOW PRESSURE SYSTEM. AN APPROACHING COLD FRONT MAY CAUSE POSSIBLE RESTRICTIONS WITH RAIN MONDAY AND TUESDAY. && .HYDROLOGY... A RAPIDLY DEEPENING SYSTEM WILL DROP HEAVY RAIN ONTO THE AREA FRIDAY NIGHT INTO SATURDAY. AT THIS TIME...MOST OF THE AREA SEEMS LIKELY TO RECEIVE 1 TO 1.75 INCHES THROUGH THE PERIOD...HOWEVER SOME AREAS NORTH OF I-80 MAY SEE IN EXCESS OF 2 INCHES. LOCALIZED URBAN AND SMALL STREAM FLOODING WILL BE THE MOST LIKELY PROBLEM...HOWEVER AS THE TRACK OF THE SYSTEM IS PINNED DOWN MORE CLOSELY...AND EXACT BASINS WHICH WILL RECEIVE THE MOST RAINFALL ARE DETERMINED...A MORE ADEQUATE DETERMINATION OF THE RISK OF RIVER FLOODING CAN BE MADE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...FLOOD WATCH THROUGH SATURDAY AFTERNOON FOR MDZ001. OH...FLOOD WATCH THROUGH SATURDAY AFTERNOON FOR OHZ039>041-048>050- 057>059-068-069. PA...FLOOD WATCH THROUGH SATURDAY AFTERNOON FOR PAZ014-020>023-029- 031-073>076. FLOOD WATCH FROM 11 PM EDT THIS EVENING THROUGH LATE SATURDAY NIGHT FOR PAZ007>009-013-015-016. WV...FLOOD WATCH THROUGH SATURDAY AFTERNOON FOR WVZ001>004-012- 021>023-041. && $$ 15/33
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
312 PM EDT FRI JUN 26 2015 .SYNOPSIS... UNSEASONABLY DEEP LOW PRESSURE WILL MOVE THROUGH THE REGION ON SATURDAY...WITH MUCH COLDER AND WINDY CONDITIONS TO END THE WEEKEND. UNSETTLED WEATHER REMAINS THROUGH MUCH OF THE UPCOMING WEEK. && .NEAR TERM /THROUGH TONIGHT/... UPPER TROUGH OVER THE WESTERN GREAT LAKES WILL CONTINUE TO DEEPEN AS IT PIVOTS EASTWARD TOWARD THE OHIO VALLEY OVERNIGHT. THIS AND A COUPLED JET WILL HELP TO INTENSIFY THE SURFACE LOW AS IT MOVES TOWARD NORTHERN OHIO BY SATURDAY MORNING. TONIGHT...THE WARM FRONT WILL BE LIFTED ACROSS THE REGION. THE MODELS HAVE STRUGGLED TO RESOLVE THIS INITIAL PRECIPITATION WITH THE BOUNDARY...BUT SO FAR THE RUC AND THE HRRR HAVE HANDLED IT BEST...SO LOW CHANCE POPS WERE MAINTAIN AND THEN RAMPED UP AS THE LOW APPROACHES. OVERNIGHT...STRONG ISENTROPIC LIFT AND DEEP MOISTURE WILL PROVIDE FOR A PROLONGED PERIOD OF RAINFALL. PWAT VALUES WILL APPROACH 1.75 TO 2.00 INCHES...WHICH SHOULD ALLOW FOR DECENT RAINFALL RATES AT LEAST UNTIL MORNING BEFORE DRY AIR WRAPS AROUND THE OCCLUDING LOW PRESSURE. WITH AMPLE CLOUD COVER AND PRECIPITATION...DO NOT SEE TEMPERATURES DOING MUCH OVERNIGHT. SO...LOWS WERE KEPT ABOVE SEASONAL AVERAGES...IN THE 60`S. && .SHORT TERM /SATURDAY THROUGH MONDAY/... HEAVY RAIN EVENT WILL BE ONGOING AT THE START OF THIS PERIOD...WITH SURFACE LOW POSITIONED IN WESTERN OHIO. CONTINUE TO BE IMPRESSED WITH THIS SYSTEM...AS IT COMBINES WINTERTIME SYNOPTIC FORCING WITH SUMMERTIME MOISTURE. OVERALL SURFACE LOW PROGRESSION AND DEEPENING WILL SLOW WITH TIME AS H500 PATTERN CLOSES OFF AND SYSTEM BECOMES VERTICALLY STACKED ACROSS NORTHEAST OHIO SATURDAY NIGHT. THE UPPER LOW WILL THEN DRIFT NORTHEASTWARD OVER THE EASTERN GREAT LAKES THROUGH SUNDAY BEFORE FINALLY PULLING AWAY SUNDAY NIGHT. TAIL END OF HEAVY RAIN SHIELD WILL PROGRESS FROM SOUTHWEST TO NORTHEAST DURING THE MORNING AS THE LONG-ADVERTISED DRY SLOT DEVELOPS. THE TIMING AND POSITIONING OF THIS FEATURE WILL OF COURSE ULTIMATELY DETERMINE WHERE THE HEAVIEST RAINFALL TOTALS OCCUR. FOR NOW...IT APPEARS THAT AREAS ALONG AND NORTH OF I-80 WILL SEE THE HIGHER TOTALS AS DRY SLOT MAY NOT BE ABLE TO FULLY DEVELOP IN THIS REGION BEFORE COMMAHEAD PRECIP MOVES IN. THIS IS WHERE THE 2+ INCH STORM TOTAL RAINFALL VALUES ARE MOST LIKELY. AREAS TO THE SOUTH WILL STILL REACH THE 1-2 INCH RANGE AT LEAST WITH LOCALLY HIGHER TOTALS. WHILE FLOODING ISSUES ARE NOT EXPECTED TO BE WIDESPREAD...ENOUGH OF A THREAT REMAINS TO MAINTAIN THE GOING WATCH. THERE IS AN INTERESTING CONDITIONAL COMPONENT TO THE SATURDAY AFTERNOON/EVENING FORECAST. BUFKIT SOUNDINGS ARE SHOWING A FAIRLY DECENT ENVIRONMENT THAT COULD FAVOR STRONG TO EVEN SEVERE THUNDERSTORMS. BETWEEN 18Z SAT AND 00Z SUN...PROFILES SHOW IMPRESSIVELY CURVED HODOGRAPHS IN THE DRY SLOT ACROSS SOUTHWEST PA WITH DIRECTIONAL AND SPEED SHEAR. THE NAM HINTS AT THE DEVELOPMENT OF A FAST-MOVING CONVECTIVE LINE AFTER 21Z. INSTABILITY IS THE CRITICAL FACTOR. IF THE DRY SLOT DEVELOPS EARLY ENOUGH TO ALLOW FOR GOOD DIABATIC HEATING...THE ENVIRONMENT COULD QUITE READILY SUPPORT STRONG STORMS. CERTAINLY SOMETHING TO MONITOR. A BRIEF LULL IN PRECIP IS EXPECTED BEHIND ANY EVENING CONVECTION BUT NUMEROUS SHOWERS WILL REDEVELOP DURING THE NIGHT AS THE WRAPAROUND PRECIP ARRIVES IN THE DEFORMATION ZONE. THIS WILL BE OF A MORE SHOWERY AND LIGHTER NATURE...AND SHOULD NOT AGGRAVATE ANY WATER PROBLEMS THAT MANAGE TO OCCUR. THIS PATTERN WILL CONTINUE THROUGH SUNDAY MORNING...WITH PRECIP SLOWLY PULLING AWAY DURING THE AFTERNOON AND EVENING. A LONGER DRY BREAK SUNDAY NIGHT WILL BE FOLLOWED ANOTHER SYSTEM ON MONDAY...WITH MORE RAIN IN THE FORECAST. TEMPERATURES WILL OF COURSE BE BELOW SEASONAL LEVELS IN THIS TROFFY PATTERN. SUNDAY IN PARTICULAR LOOKS COOL WITH HIGHS REACHING THE 60S AT BEST. RECORD LOW MAXIMUM TEMPERATURES COULD BE CHALLENGED AT PIT. CL && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... LONGER RANGE MODEL GUIDANCE FAVORS DRASTICALLY INCREASED RIDGING IN THE WEST WITH DOWNSTREAM DEEPENING TROUGHING ACROSS THE GREAT LAKES. THIS WILL LIKELY KEEP THINGS FAIRLY ACTIVE AND WET OVER THE CWA...WITH TEMPERATURES LIKELY TO REMAIN A BIT BELOW NORMAL. MODEL TIMING OF INDIVIDUAL SHORT WAVES IS EXCEEDINGLY SUSPECT AT THIS JUNCTURE...HOWEVER MONDAY NIGHT INTO TUESDAY PROBABLY SEES THE BEST SHOT AT WIDESPREAD RAIN SHOWERS ACROSS THE AREA. FRIES && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... WARM FRONT SHOULD SLOWLY LIFT ACROSS THE REGION THIS EVE AND OVERNIGHT. AT THIS TIME...WITH CONVECTION FIRING IN CENTRAL OHIO...DECIDED TO ADD A VCTS MENTION TO ZZV. FURTHER NORTH...WILL LEAVE TS MENTION OUT AS THUNDERSTORM COVERAGE LOOKS TO BE LOWER BASED ON MODEL SOUNDINGS AND THE TIMING OF PRECIP ONSET WITH THE BOUNDARY. MAINLY MVFR CIG RESTRICTIONS ARE ANTICIPATED UNTIL THE LOW APPROACHES OVERNIGHT AND STRATIFORM RAINFALL APPROACHES AT WHICH POINT MOST SITES SHOULD EXPERIENCE A PERIOD OF IFR CIGS AND/OR VISIBILITY. CONDITIONS MAY IMPROVE TOWARD MORNING AS THE DRY SLOT APPROACHES. STARTED AN UPWARD TREND BUT DID NOT GO BACK TO VFR AT THIS TIME. THUNDERSTORMS MAY BE POSSIBLE TOMORROW AFTERNOON IF WE CAN SCATTER OUT THE CLOUDS IN THE DRY SLOT. .OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/... RESTRICTIONS ARE LIKELY OVER THE WEEKEND WITH PASSAGE OF A STRONG LOW PRESSURE SYSTEM. AN APPROACHING COLD FRONT ON MONDAY MAY CAUSE POSSIBLE RESTRICTIONS WITH RAIN. && .HYDROLOGY... A RAPIDLY DEEPENING SYSTEM WILL DROP HEAVY RAIN ONTO THE AREA FRIDAY NIGHT INTO SATURDAY. AT THIS TIME...MOST OF THE AREA SEEMS LIKELY TO RECEIVE 1 TO 1.75 INCHES THROUGH THE PERIOD...HOWEVER SOME AREAS NORTH OF I-80 MAY SEE IN EXCESS OF 2 INCHES. LOCALIZED URBAN AND SMALL STREAM FLOODING WILL BE THE MOST LIKELY PROBLEM...HOWEVER AS THE TRACK OF THE SYSTEM IS PINNED DOWN MORE CLOSELY...AND EXACT BASINS WHICH WILL RECEIVE THE MOST RAINFALL ARE DETERMINED...A MORE ADEQUATE DETERMINATION OF THE RISK OF RIVER FLOODING CAN BE MADE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH SATURDAY AFTERNOON FOR MDZ001. OH...FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH SATURDAY AFTERNOON FOR OHZ039>041-048>050-057>059-068-069. PA...FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH SATURDAY AFTERNOON FOR PAZ014-020>023-029-031-073>076. FLOOD WATCH FROM 11 PM EDT THIS EVENING THROUGH LATE SATURDAY NIGHT FOR PAZ007>009-013-015-016. WV...FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH SATURDAY AFTERNOON FOR WVZ001>004-012-021>023-041. && $$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1231 PM CDT Fri Jun 26 2015 .SHORT TERM: (Tonight through Friday) Issued at 322 AM CDT Fri Jun 26 2015 Active elements of large MCS over western MO will continue to move south and southeast early this morning while the stratiform rain area will continue to move east. RAP and HRRR continue to support the solution that stratiform rain area with moderate to occasionally heavy rain will slowly move east across the CWA today. RAP as well as the GFS/NAM show strong 850-925 moisture convergence moving from west to east across the area with PWATS near 2 inches. Will maintain going flash flood watch given these parameters and the saturated soils. Both the GFS and NAM show low level moisture convergence shifting southeast of the CWA by 00Z with the upper trough shifting east of the CWA by 06Z. Think that that the current end time of the flash flood watch of 00Z still is okay because the heavy rain should have ended by then. Rain chances overnight should be just scattered showers over the southeast half of the CWA after midnight. Temperatures will be much cooler today behind the front with cloudy skies, cold air advection, and rain. Highs in most areas will only be in the 70s. Britt .LONG TERM: (Tonight through Thursday) Issued at 322 AM CDT Fri Jun 26 2015 (Saturday and Sunday) Dry weather is expect on Saturday as subsidence sets in behind the exiting trough. Then chances of showers and thunderstorms increases Sunday and Sunday night as a shortwave trough dives down embedded in the northwestly flow aloft. MUCAPES will be in the 1500-2000 J/kg range and deep layer shear will be in the 30-40kt range which may be sufficient to produce a few isolated severe storms. (Monday through Thursday) Amplified upper pattern will dominate next week with shortwave troughs moving through the area every other day. This will keep a chance of showers and thunderstorm in the forecast during the period with below normal temperatures. Britt && .AVIATION: (For the 18z TAFs through 18z Saturday Afternoon) Issued at 1226 PM CDT Fri Jun 26 2015 Main concerns over the next 24 hours will be on chances of rain and ceiling trends. Actual cold front is still across north- central Missouri so will have to monitor chances for showers and possibly a thunderstorm out ahead of this boundary. KUIN most likely to see rain this afternoon whereas KCOU and metro St. Louis TAF sites have a lesser chance so included a VCSH group for now. Thinking ceiling trends will improve a bit through late this afternoon before coming back down into MVFR...with IFR also possible...particularly for metro St. Louis terminals. Ceilings should scatter out by Saturday morning with northerly winds around 10 knots continuing. Specifics for KSTL: Main concerns over the next 24 hours will be on chances of rain and ceiling trends. Actual cold front is still across north- central Missouri so will have to monitor chances for showers and possibly a thunderstorm out ahead of this boundary. Have a VCSH group for late this afternoon/early this evening for nwo but will continue to have to monitor. Thinking ceiling trends will improve a bit through late this afternoon before coming back down into MVFR...with IFR also possible late tonight. Ceilings should scatter out by Saturday morning with northerly winds around 10 knots continuing through Saturday afternoon. Gosselin && .LSX WATCHES/WARNINGS/ADVISORIES: MO...FLASH FLOOD WATCH until 7 PM CDT this evening FOR Knox MO-Lewis MO-Marion MO-Monroe MO-Pike MO-Ralls MO-Shelby MO. IL...FLASH FLOOD WATCH until 7 PM CDT this evening FOR Adams IL-Brown IL-Pike IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1229 PM CDT FRI JUN 26 2015 .UPDATE... ISSUED AT 1151 AM CDT FRI JUN 26 2015 NO SIGNIF CHANGES...BUT DID ADJUST TEMPS TO SLOW THE FCST RISE OVER S-CNTRL NEB WHERE CLOUDS WERE LIMITING HEATING. THE BAND OF SHWRS DROPPING S HAS DISSIPATED. DID ADD SOME 20% POPS TO THE FCST FOR ISOLATED SHWRS THAT MIGHT DEVELOP IN DAYTIME HEATING 4PM- 7PM. CONFIDENCE IS LOW. FCST SOUNDINGS FROM THE RAP AND NAM INDICATE NO CAP WHILE THE GFS MIXES DEEPER AND HAS A CAP. THE SOURCE REGION IS FROM SD AND THE 12Z ABR SOUNDING DOES INDICATE INSTABILITY AND NO CAP EVEN WITH MIXING OUT THE DWPT IN THE SFC LAYER. THERE IS NO DISCERNIBLE FORCING MECHANISM...BUT BELIEVE ONE OR TWO SHWRS COULD POP-UP. MOST LOCATIONS WILL REMAIN DRY AND ANYTHING THAT DOES DEVELOP WILL DISSIPATE EARLY THIS EVE. OVERALL...EXPECT A NICE AFTERNOON WITH A GOOD AMOUNT OF CU AND STRATOCU. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 340 AM CDT FRI JUN 26 2015 A WEAKENING LINE OF SHOWERS AND ISOLATED THUNDERSTORMS IS MAKING ITS WAY SOUTH ACROSS NORTHERN NEBRASKA THIS MORNING. SATELLITE AND RADAR TRENDS SHOW THIS LINE IS WEAKENING RAPIDLY...AND ONLY KEPT SOME SMALL POPS PRIMARILY NORTH OF HIGHWAY 92 DURING THE EARLY MORNING HOURS TO REFLECT THIS. OTHERWISE...SKY COVER IS ANTICIPATED TO DECREASE THROUGH THE MORNING HOURS...WITH A PARTLY TO MOSTLY SUNNY AFTERNOON ALONG WITH PLEASANT TEMPERATURES IN STORE. OVERNIGHT...EXPECT SURFACE HIGH PRESSURE TO TRANSITION FROM THE HIGH PLAINS TOWARDS THE MISSOURI RIVER VALLEY...RESULTING IN LIGHT WINDS ACROSS THE LOCAL AREA. WITH LIGHT WINDS...AND MAINLY CLOUD FREE SKIES...FELT SAFE UNDERCUTTING GUIDANCE A FEW DEGREES ON LOW TEMPERATURES TO START THE WEEKEND...WITH LOWS EXPECTED TO DIP INTO THE MID TO UPPER 50S ACROSS THE MAJORITY OF THE FORECAST AREA. OTHER THAN THE SMALL CHANCE FOR SHOWERS WITH A WEAK UPPER WAVE VISIBLE IN WV IMAGERY TO OUR NORTH THIS MORNING...EXPECT DRY CONDITIONS OVER THE NEXT 24 HOURS WITH LIGHT WINDS AND SEASONABLY COOL TEMPERATURES FOR LATE JUNE. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 340 AM CDT FRI JUN 26 2015 LOOKING AT THE START OF THE LONG TERM PERIOD SATURDAY MORNING...MODELS ARE IN GOOD AGREEMENT SHOWING A WELL AMPLIFIED UPPER LEVEL PATTERN ACROSS THE CONUS. HIGH PRESSURE CENTERED OVER THE NV/UT/AZ BORDER AREA IS RESULTING IN RIDGING WELL NORTH INTO WRN CANADA...WHILE AN AREA OF LOW PRESSURE IS EXPECTED TO BE LOCATED OVER THE MIDWEST REGION. THE RESULT OVER THE CENTRAL PLAINS IS SHARP N/NWRLY FLOW...AND AT THIS TIME NO NOTABLE DISTURBANCES IN THE IMMEDIATE AREA. LITTLE CHANGE IN THE FLOW IS EXPECTED FOR THIS UPCOMING WEEKEND...AND WHILE NO DISTURBANCES LOOK TO PASS DIRECTLY OVER THE CWA...MODELS ARE IN GOOD AGREEMENT SHOWING ONE PASSING SOUTH THROUGH THE MAIN FLOW JUST OFF TO OUR EAST. THE CURRENT FORECAST REMAINS A DRY ONE...BUT A LITTLE UNCERTAINTY EXISTS WITH THAT...MAINLY DURING THE LATE SUNDAY AFTERNOON/EVENING HOURS. WHILE THE SURFACE PATTERN ACROSS THE AREA ON SATURDAY IS DOMINATED BY HIGH PRESSURE...BRINGING FAIRLY LIGHT WINDS...SUNDAY A FRONTAL BOUNDARY WILL BE PUSHED SOUTH THROUGH THE AREA BY THIS UPPER LEVEL DISTURBANCE. SIMILAR TO RECENT FRONTAL PASSAGES...NOT LOOKING AT A NOTABLE DROP IN TEMPS...BUT IT WILL USHER IN ANOTHER ROUND OF NRLY WINDS ACROSS THE CWA DURING THE DAYTIME HOURS. SOME MODELS SUGGEST THE DEVELOPMENT OF THUNDERSTORMS IN PROXIMITY TO THIS FRONT...WHICH BY LATE SUNDAY AFTERNOON SHOULD BE JUST SOUTH OF THE CWA...BUT IS CLOSE ENOUGH TO ESP OUR NC KS COUNTIES THAT IT WOULDNT TAKE MUCH OF A SLOW DOWN FROM MODELS AND POPS MAY NEED TO BE ADDED TO THE FORECAST. WILL SEE HOW THINGS TREND. FORECAST STILL CALLING FOR DEWPOINTS THIS WEEKEND TO BE IN THE MID 50S TO LOWER 60S...WITH HIGHS IN THE 80S FOR MOST OF THE CWA...THOUGH A FEW LOWER 90S ARE POSSIBLE MAINLY ACROSS NC KS. AS WE GET INTO THE NEXT WORK WEEK...MONDAY THROUGH THURSDAY...THUNDERSTORM CHANCES DO EVENTUALLY MAKE THEIR WAY BACK INTO THE FORECAST. MONDAY MORNING...OVERALL NOT A LOT OF CHANGE IS EXPECTED LOOKING AT THE UPPER LEVEL PATTERN...REMAINING WELL AMPLIFIED. HOWEVER...A COUPLE OF PIECES OF SHORTWAVE ENERGY ARE SHOWN BY MODELS TO BE WORKING INTO THE PAC NW REGION MONDAY MORNING...BREAKING DOWN THE RIDGE A TOUCH AS WE GET INTO TUESDAY. THE NEXT CHANCED FOR THUNDERSTORMS CURRENTLY IN THE FORECAST COME TUESDAY NIGHT THROUGH THURSDAY...AS THESE WEAKER DISTURBANCES MOVE THROUGH THE MORE NWRLY FLOW. CONFIDENCE THOUGH IS ON THE LOWER SIDE...WITH SOME DIFFERENCES IN MODELS STILL IN PLACE TO BE WORKED OUT IN THE COMING DAYS. OTHERWISE...NO BIG SWINGS IN TEMPERATURES EXPECTED...WITH HIGHS GENERALLY IN THE 80S. && .AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z SAT AFTERNOON) ISSUED AT 1229 PM CDT FRI JUN 26 2015 THIS AFTERNOON: VFR WITH SCT 2000-2500 FT STRATOCU LIFTING TO AROUND 5K FT. THERE IS A LOW PROBABILITY OF A BRIEF SHWR PRIMARILY AFTER 20Z. N WINDS 10-12 KTS WITH OCCASIONAL G17-18 KTS. CONFIDENCE: MEDIUM TONIGHT: BECOMING VFR SKC BY 02Z. LGT AND VRBL OR CALM WINDS. CONFIDENCE: HIGH SAT THRU 18Z: VFR WITH A FEW STRATOCU DEVELOPING AFTER 15Z. LIGHT NW WINDS. CONFIDENCE: HIGH && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...HALBLAUB SHORT TERM...ROSSI LONG TERM...ADP AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1227 PM CDT FRI JUN 26 2015 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 333 AM CDT FRI JUN 26 2015 THE CHANCE FOR THUNDERSTORMS TODAY IS THE PRIMARY FORECAST CONCERN. THEN A GENERALLY DRY AND WARMER WEEKEND...WITH THE EXCEPTION OF A SMALL CHANCE FOR STORMS SUNDAY. NORTHWEST MID LEVEL FLOW ACROSS THE PLAINS WAS NOTED ON EVENING UPPER AIR CHARTS AND SHORT TERM MODEL OUTPUT. A COUPLE OF SHORTWAVES COULD BE IDENTIFIED WITHIN THE FLOW...AND RECENT RAP HEIGHT FORECASTS ALONG WITH WATER VAPOR IMAGERY SUGGESTED ONE WAVE WAS MOVING OUT OF SOUTHEAST NEBRASKA AS OF 3 AM...AND ANOTHER WAS APPROACHING NORTHEAST NEBRASKA FROM SOUTH DAKOTA. BOTH WAVES WERE TRIGGERING SCATTERED SHOWERS AND STORMS...HOWEVER THE STRONGEST WERE IN NORTHERN KANSAS WHERE LIFT WAS MAXIMIZED JUST NORTH OF FRONTAL BOUNDARY EXTENDING FROM KANSAS CITY TO WICHITA. GIVEN NORTHWEST FLOW ALOFT...SOUTHERN STORMS MOVING OUT OF OUR AREA WILL REMAIN THERE THIS MORNING. SHORTWAVE TO THE NORTH WILL GRADUALLY WORK SOUTHEAST TODAY...BUT ABSENCE OF SURFACE BOUNDARY/LOW LEVEL CONVERGENCE SUGGESTS ACTIVITY WILL REMAIN ISOLATED TO SCATTERED IN NATURE. IN FACT...MANY SHORT RANGE MESOSCALE MODELS INCLUDING HRRR AND RAP SUGGEST A DECREASE IN ACTIVITY THROUGH THE MORNING BEFORE AFTERNOON HEATING HELPS BUBBLE UP WIDELY SCATTERED AFTERNOON CONVECTION. SO WILL PLAY THE HIGHEST POPS IN NORTHEAST NEBRASKA THIS MORNING...THEN BROADBRUSH SMALL CHANCES THROUGH THE AFTERNOON ACROSS MUCH OF EASTERN NEBRASKA AND SOUTHWEST IOWA. COULD SEE SOME LINGERING SHOWERS/STORMS IN SOUTHEAST NEBRASKA OR SOUTHWEST IOWA DURING THE EARLY EVENING BEFORE SHORTWAVE PUSHES FARTHER AWAY AND WE LOSE AFTERNOON HEATING. OTHERWISE WE WILL SEE A TENDENCY TOWARD NORTHERLY LOW LEVEL FLOW TONIGHT AND SATURDAY AS HIGH PRESSURE SETTLES ACROSS THE REGION...AND BRINGS SLIGHTLY DRIER AIR INTO OUR AREA. SHOULD SEE PLENTY OF SUNSHINE SATURDAY WITH HIGHS IN THE LOWER 80S AFTER MORNING LOWS IN THE LOWER 60S. SOUTHERLY FLOW WILL RETURN SATURDAY NIGHT AS A SHORTWAVE DIVES INTO MINNESOTA THEN EVENTUALLY IOWA/WISCONSIN/ILLINOIS. SURFACE COLD FRONT WILL FOLLOW THIS WAVE AND SWEEP THROUGH EASTERN NEBRASKA AND SOUTHWEST IOWA ON SUNDAY. CONVECTION SATURDAY NIGHT SHOULD BE CONFINED TO AREAS TO OUR NORTHEAST WHERE STRONG WARM ADVECTION IS REALIZED JUST AHEAD OF MID LEVEL WAVE. ON SUNDAY...AXIS OF BEST LIFT NEAR SHORTWAVE AND SURFACE REFLECTION WILL STILL LIE WELL TO OUR EAST AND NORTHEAST IN MINNESOTA AND IOWA...BUT COULD SEE A FEW SHOWERS OR STORMS NEAR AND EAST OF THE NEBRASKA/IOWA BORDER AS COLD FRONT SWINGS SOUTHEAST. SHOULD SEE NICE WARMING ON SUNDAY AS SOUTHWEST FLOW AHEAD AND NORTHWEST FLOW BEHIND FRONT WILL PROMOTE DECENT MIXING. HIGHS THEN SHOULD EASILY REACH THE MID AND UPPER 80S. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 333 AM CDT FRI JUN 26 2015 GENERAL MID LEVEL FLOW PATTERN CHANGES ONLY A LITTLE DURING THE WEEK. BROAD HIGH PRESSURE WILL REMAIN OVER THE SOUTHWESTERN STATES THROUGH THE PERIOD. MEANWHILE UPPER LOW IN THE EASTERN GREAT LAKES EARLY IN THE PERIOD WILL LIFT TO THE NORTHEAST...LEAVING BROAD TROUGH BEHIND OVER THE EASTERN HALF OF THE COUNTRY. IN BETWEEN THESE FEATURES...FLOW IN THE CENTRAL PLAINS WILL SHIFT FROM NEARLY NORTHERLY TO NORTHWESTERLY BY MID WEEK. SEVERAL IMPULSES RIDING OVER WESTERN RIDGE WILL ENTER THE PLAINS...BRINGING OFF AND ON THUNDERSTORM CHANCES TO OUR REGION. GFS AND ECMWF ARE IN FAIRLY GOOD AGREEMENT WITH THIS OVERALL PATTERN CHANGE...BUT DIFFER ON TIMING OF PRECIPITATION-PRODUCING SHORTWAVES. HOWEVER BOTH MODELS ARE RELATIVELY SIMILAR IN DROPPING A MORE SIGNIFICANT SHORTWAVE INTO THE PLAINS ON TUESDAY...INCREASING THUNDERSTORM CHANCES IN EASTERN NEBRASKA AND WESTERN IOWA TUESDAY NIGHT AS ATTENDANT SURFACE LOW AND FRONTAL SYSTEM MOVE THROUGH THE REGION. WILL HAVE THE HIGHEST PRECIP CHANCES AT THIS TIME...THOUGH STILL ONLY IN THE CHANCE CATEGORY AS MOISTURE RETURN AFTER SUNDAY COLD FRONT WILL BE SLOW TO OCCUR. SHOULD SEE MINIMAL RAIN CHANCES BEHIND THIS SYSTEM ON WEDNESDAY AND THURSDAY...BUT GIVEN UNCERTAINTY IN SMALL-SCALE MID LEVEL FEATURES...CAN NOT RULE OUT A STRAY STORM OR TWO. OTHERWISE EXPECT TEMPERATURES TO AVERAGE 60S AND 80S FOR LOWS AND HIGHS THROUGH THE PERIOD. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1226 PM CDT FRI JUN 26 2015 VFR CONDITIONS ARE EXPECTED TO PREVAIL AT ALL TAF SITES. A FEW SHOWERS AND THUNDERSTORMS COULD POP UP THIS AFTERNOON WITH DAYTIME HEATING...HOWEVER CONFIDENCE IN COVERAGE STILL REMAINS FAIRLY LOW. NORTHERLY WINDS WILL BECOME LIGHT AND VARIABLE TONIGHT WITH SKIES CLEARING THROUGH SATURDAY MORNING. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...DERGAN LONG TERM...DERGAN AVIATION...KG
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1225 PM CDT FRI JUN 26 2015 .SYNOPSIS... ISSUED AT 336 AM CDT FRI JUN 26 2015 AT 08Z...ISOLATED SHOWERS CONTINUE TO TRAIL TO THE WEST ACROSS NCTRL NEBR BUT HAVE SHOWN RECENT TRENDS OF SLOWLY DISSIPATING AS THEY DROP SOUTHWARD. MOST OF THE THUNDERSTORM ACTIVITY RESIDES ACROSS PARTS OF KS AND MO. UPSTREAM ACROSS THE WRN DAKOTAS...MT AND WYOMING SKIES ARE CLEAR IN MOST AREAS. TEMPERATURES IN WRN NEBR RANGE FROM 59 TO 64 DEGREES. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 336 AM CDT FRI JUN 26 2015 TODAY...THE H5 UPPER TROUGH AXIS AND ASSOCIATED VORT MAX AT 12Z TO BE LOCATED IN WRN IA. UPSTREAM...THERE WILL BE CHANNELIZED VORTICITY TODAY. WHILE THIS WOULD SEEM SUPPORTIVE OF AT LEAST ISOLATED SHOWERS ACROSS THE ERN HALF OF FA AS INDICATED BY THE HRRR AND RAP MODELS...LATEST NAM AND GFS ARE DRIER. A CROSS SECTION ACROSS EASTERN AREAS SHOWS SUFFICIENT MOISTURE AVBL EXCEPT THAT GENERAL SUBSIDENCE NOTED. CURRENT FCST IS DRY TODAY...ALTHOUGH ISOLATED SHOWERS WOULD BE POSSIBLE. CURRENT BAND OF SHOWERS EAST-WEST ACROSS CHERRY COUNTY TO HOLT COUNTY CONTINUES TO DIMINISH IN COVERAGE AND EXPECTED TO DISSIPATED BY 12Z. THERE IS HOWEVER INCREASING COVERAGE OF STRATUS ACROSS THE CENTRAL SANDHILLS INCLUDING THEDFORD ATTM. SATELLITE TRENDS SHOWS AREA IS DEVELOPING TO THE SOUTHWEST WITH MAINLY MID LEVEL CLOUDS COVERING NCTRL NEBR. ANY STRATUS SHOULD BEGIN TO SCATTER OUT AFTER 15Z WITH SCT TO BKN STRATOCUMULUS EXPECTED TODAY. HIGHS TODAY NEAR PREVIOUS FCST FROM 77 TO 81 DEGREES. WINDS STEADY NORTH TO NORTHEAST 5 TO 10 MPH. LOOKING SYNOPTICALLY ACROSS THE CONUS...THE UPPER RIDGE WILL INTENSIFY ACROSS THE WRN CONUS AS THE UPPER TROUGH AMPLIFIES FROM THE GREAT LAKES INTO THE MID MISSISSIPPI VALLEY. WEAK SURFACE HIGH PRESSURE WILL BUILD SOUTH FROM THE NRN INTO THE CNTRL PLAINS. TONIGHT...UPPER FLOW WILL REMAIN NWRLY AS SURFACE HIGH PRESSURE RESIDES OVER THE CENTRAL PLAINS. SKIES EXPECTED TO BE MOSTLY CLEAR AND TEMPERATURES WILL BE COOLER FROM 55 TO 59 DEGREES. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 336 AM CDT FRI JUN 26 2015 THIS WEEKEND INTO THE FIRST OF NEXT WEEK WILL SEE A RIDGE DOMINATE THE WESTERN CONUS AS A TROUGH DIGS OVER THE GREAT LAKES REGION. NORTHWEST FLOW ACROSS THE HIGH PLAINS...HOWEVER THE RIDGE RIDING SHORT WAVES/STORMS ARE EXPECTED TO REMAIN TO THE NORTHEAST OF THE CWA. TEMPS ABOVE NORMAL /MORE SUMMER LIKE/ WITH HIGHS IN THE MID 80S TO LOWER 90S. MONDAY NIGHT INTO TUESDAY A STRONG DISTURBANCE WILL RIDE THE CREST OF THE RIDGE AND CAUSE A SFC LOW PRESSURE TO DEVELOP ON THE LEE SIDE OF THE ROCKIES. BY TUESDAY NIGHT THE LOW PRESSURE ALONG WITH A TRAILING WEAK COLD FRONT WILL SLIDE SOUTH ACROSS THE CENTRAL/HIGH PLAINS. MODELS STILL DIFFERING ON THE STRENGTH OF LOW PRESSURE AND HOW STRONG THE CAP WILL BE. THUS STORMS ARE POSSIBLE BUT THERE IS GREAT UNCERTAINTY. THE LATEST GFS HAS GONE DRIER WHILE THE ECMWF HAS INCREASED QPF ACROSS THE AREA. ONE AGREEMENT IS A SLIGHT BOOST OF TEMPS FOR TUESDAY AHEAD OF THE FRONT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1223 PM CDT FRI JUN 26 2015 LOW CIGS FROM MORNING STRATUS DECK WILL CONTINUE TO RISE THIS AFTERNOON. CLOUD COVER WILL BEGIN TO DECREASE THIS EVENING WITH SKC EXPECTED OVERNIGHT AND INTO SATURDAY MORNING. VFR CONDITIONS WILL PREVAIL ACROSS ALL OF WESTERN AND NORTH CENTRAL NEBRASKA THROUGH THE CURRENT TAF PERIOD. && .HYDROLOGY... ISSUED AT 336 AM CDT FRI JUN 26 2015 CURRENT FLOOD WARNINGS FOR BRADY ON THE PLATTE RIVER SYSTEM AND LEWELLEN ON THE NORTH PLATTE RIVER SYSTEM REMAIN IN PLACE. RIVER LEVELS CONTINUE TO SLOWLY FALL. THE SOUTH PLATTE RIVER AT ROSCOE IS CURRENTLY JUST BELOW FLOOD STAGE AT 8.9 FEET AND WILL CONTINUE TO SLOWLY FALL THROUGH EARLY NEXT WEEK WITH THE FLOOD ADVISORY TO CONTINUE. THE SOUTH PLATTE RIVER AT NORTH PLATTE IS CURRENTLY NEAR 12.35 FEET AND WILL ALSO SLOWLY FALL THROUGH EARLY NEXT WEEK WITH THE FLOOD ADVISORY TO CONTINUE. RECENT RAINFALL FROM LAST EVENING DOES NOT APPEAR TO CAUSE CONCERN FOR ANY RISES...ONLY A SLIGHTLY LESS FALL IN STAGE IN THE NEAR TERM. RIVER LEVELS ALONG THE NORTH PLATTE RIVER UPSTREAM OF LAKE MCCONAUGHY ARE ELEVATED NEAR ACTION STAGE AT LISCO WHILE REMAINING ABOVE MINOR FLOOD STAGE AT LEWELLEN THROUGH EARLY NEXT WEEK. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...ROBERG SHORT TERM...ROBERG LONG TERM...MASEK AVIATION...MARTIN HYDROLOGY...ROBERG
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1151 AM CDT FRI JUN 26 2015 .UPDATE... ISSUED AT 1151 AM CDT FRI JUN 26 2015 NO SIGNIF UPDATES CHANGES...BUT DID ADJUST TEMPS TO SLOW THE FCST RISE OVER S-CNTRL NEB WHERE CLOUDS WERE LIMITING HEATING. THE BAND OF SHWRS DROPPING S HAS DISSIPATED. DID ADD SOME 20% POPS TO THE FCST FOR ISOLATED SHWRS THAT MIGHT DEVELOP IN DAYTIME HEATING 4PM- 7PM. CONFIDENCE IS LOW. FCST SOUNDINGS FROM THE RAP AND NAM INDICATE NO CAP WHILE THE GFS MIXES DEEPER AND HAS A CAP. THE SOURCE REGION IS FROM SD AND THE 12Z ABR SOUNDING DOES INDICATE INSTABILITY AND NO CAP EVEN WITH MIXING OUT THE DWPT IN THE SFC LAYER. THERE IS NO DISCERNIBLE FORCING MECHANISM...BUT BELIEVE ONE OR TWO SHWRS COULD POP-UP. MOST LOCATIONS WILL REMAIN DRY AND ANYTHING THAT DOES DEVELOP WILL DISSIPATE EARLY THIS EVE. OVERALL...EXPECT A NICE AFTERNOON WITH A GOOD AMOUNT OF CU AND STRATOCU. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 340 AM CDT FRI JUN 26 2015 A WEAKENING LINE OF SHOWERS AND ISOLATED THUNDERSTORMS IS MAKING ITS WAY SOUTH ACROSS NORTHERN NEBRASKA THIS MORNING. SATELLITE AND RADAR TRENDS SHOW THIS LINE IS WEAKENING RAPIDLY...AND ONLY KEPT SOME SMALL POPS PRIMARILY NORTH OF HIGHWAY 92 DURING THE EARLY MORNING HOURS TO REFLECT THIS. OTHERWISE...SKY COVER IS ANTICIPATED TO DECREASE THROUGH THE MORNING HOURS...WITH A PARTLY TO MOSTLY SUNNY AFTERNOON ALONG WITH PLEASANT TEMPERATURES IN STORE. OVERNIGHT...EXPECT SURFACE HIGH PRESSURE TO TRANSITION FROM THE HIGH PLAINS TOWARDS THE MISSOURI RIVER VALLEY...RESULTING IN LIGHT WINDS ACROSS THE LOCAL AREA. WITH LIGHT WINDS...AND MAINLY CLOUD FREE SKIES...FELT SAFE UNDERCUTTING GUIDANCE A FEW DEGREES ON LOW TEMPERATURES TO START THE WEEKEND...WITH LOWS EXPECTED TO DIP INTO THE MID TO UPPER 50S ACROSS THE MAJORITY OF THE FORECAST AREA. OTHER THAN THE SMALL CHANCE FOR SHOWERS WITH A WEAK UPPER WAVE VISIBLE IN WV IMAGERY TO OUR NORTH THIS MORNING...EXPECT DRY CONDITIONS OVER THE NEXT 24 HOURS WITH LIGHT WINDS AND SEASONABLY COOL TEMPERATURES FOR LATE JUNE. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 340 AM CDT FRI JUN 26 2015 LOOKING AT THE START OF THE LONG TERM PERIOD SATURDAY MORNING...MODELS ARE IN GOOD AGREEMENT SHOWING A WELL AMPLIFIED UPPER LEVEL PATTERN ACROSS THE CONUS. HIGH PRESSURE CENTERED OVER THE NV/UT/AZ BORDER AREA IS RESULTING IN RIDGING WELL NORTH INTO WRN CANADA...WHILE AN AREA OF LOW PRESSURE IS EXPECTED TO BE LOCATED OVER THE MIDWEST REGION. THE RESULT OVER THE CENTRAL PLAINS IS SHARP N/NWRLY FLOW...AND AT THIS TIME NO NOTABLE DISTURBANCES IN THE IMMEDIATE AREA. LITTLE CHANGE IN THE FLOW IS EXPECTED FOR THIS UPCOMING WEEKEND...AND WHILE NO DISTURBANCES LOOK TO PASS DIRECTLY OVER THE CWA...MODELS ARE IN GOOD AGREEMENT SHOWING ONE PASSING SOUTH THROUGH THE MAIN FLOW JUST OFF TO OUR EAST. THE CURRENT FORECAST REMAINS A DRY ONE...BUT A LITTLE UNCERTAINTY EXISTS WITH THAT...MAINLY DURING THE LATE SUNDAY AFTERNOON/EVENING HOURS. WHILE THE SURFACE PATTERN ACROSS THE AREA ON SATURDAY IS DOMINATED BY HIGH PRESSURE...BRINGING FAIRLY LIGHT WINDS...SUNDAY A FRONTAL BOUNDARY WILL BE PUSHED SOUTH THROUGH THE AREA BY THIS UPPER LEVEL DISTURBANCE. SIMILAR TO RECENT FRONTAL PASSAGES...NOT LOOKING AT A NOTABLE DROP IN TEMPS...BUT IT WILL USHER IN ANOTHER ROUND OF NRLY WINDS ACROSS THE CWA DURING THE DAYTIME HOURS. SOME MODELS SUGGEST THE DEVELOPMENT OF THUNDERSTORMS IN PROXIMITY TO THIS FRONT...WHICH BY LATE SUNDAY AFTERNOON SHOULD BE JUST SOUTH OF THE CWA...BUT IS CLOSE ENOUGH TO ESP OUR NC KS COUNTIES THAT IT WOULDNT TAKE MUCH OF A SLOW DOWN FROM MODELS AND POPS MAY NEED TO BE ADDED TO THE FORECAST. WILL SEE HOW THINGS TREND. FORECAST STILL CALLING FOR DEWPOINTS THIS WEEKEND TO BE IN THE MID 50S TO LOWER 60S...WITH HIGHS IN THE 80S FOR MOST OF THE CWA...THOUGH A FEW LOWER 90S ARE POSSIBLE MAINLY ACROSS NC KS. AS WE GET INTO THE NEXT WORK WEEK...MONDAY THROUGH THURSDAY...THUNDERSTORM CHANCES DO EVENTUALLY MAKE THEIR WAY BACK INTO THE FORECAST. MONDAY MORNING...OVERALL NOT A LOT OF CHANGE IS EXPECTED LOOKING AT THE UPPER LEVEL PATTERN...REMAINING WELL AMPLIFIED. HOWEVER...A COUPLE OF PIECES OF SHORTWAVE ENERGY ARE SHOWN BY MODELS TO BE WORKING INTO THE PAC NW REGION MONDAY MORNING...BREAKING DOWN THE RIDGE A TOUCH AS WE GET INTO TUESDAY. THE NEXT CHANCED FOR THUNDERSTORMS CURRENTLY IN THE FORECAST COME TUESDAY NIGHT THROUGH THURSDAY...AS THESE WEAKER DISTURBANCES MOVE THROUGH THE MORE NWRLY FLOW. CONFIDENCE THOUGH IS ON THE LOWER SIDE...WITH SOME DIFFERENCES IN MODELS STILL IN PLACE TO BE WORKED OUT IN THE COMING DAYS. OTHERWISE...NO BIG SWINGS IN TEMPERATURES EXPECTED...WITH HIGHS GENERALLY IN THE 80S. && .AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z SAT MORNING) ISSUED AT 653 AM CDT FRI JUN 26 2015 WHILE A VCSH IS NOT OUT OF THE QUESTION OVER THE NEXT FEW HOURS...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD AS HIGH PRESSURE BEGINS TO APPROACH THE AREA FROM THE WEST. EXPECT MID LEVEL CLOUD COVER THIS MORNING TO BEGIN TO BREAK UP OVER THE NEXT SEVERAL HOURS...WITH CLEAR SKIES AND LIGHT NORTHERLY WINDS EXPECTED THEREAFTER. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...HALBLAUB SHORT TERM...ROSSI LONG TERM...ADP AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS ELKO NV
149 PM PDT FRI JUN 26 2015 .SYNOPSIS...HIGH PRESSURE REMAINS ENTRENCHED OVER THE BATTLE BORN STATE RESULTING IN TRIPLE DIGIT TEMPERATURES AND ISOLATED AFTERNOON THUNDERSTORMS. EXPECT THE HEAT WAVE TO PERSIST THROUGH MONDAY. && .SHORT TERM...TODAY THROUGH SUNDAY. 595 500MB HIGH IS CENTERED ALONG THE UT/NV BORDER WITH AN WEAK 500MB LOW WELL OFF THE SOUTHERN CA COAST. THIS SETUP IS DRAWING SOME MOISTURE INTO THE CWA AND CREATING UNSTABLE CONDITIONS ALOFT. SOME ISOLATED THUNDERSTORMS ARE DEVELOPING OVER NORTHERN NYE AND SOUTHERN LANDER/EUREKA COUNTIES WHERE THE DEEPER MOISTURE EXIST. NAM12...RAP...AND HRRR MODELED RADAR OUTPUT AGREE WITH THIS ASSESSMENT...BUT ALSO POINT SOME ISOLATED CONVECTION IN HUMBOLDT COUNTY. ALTHOUGH PW VALUES INCREASED THE PAST 24HRS...ANY THUNDERSTORMS THAT DO DEVELOP WILL STILL REMAIN ON THE DRY; THEREFORE THE MAIN THREAT FROM THESE IS GUSTY OUTFLOW WINDS. THIS SOUTHERN FLOW ALOFT WILL BUILD THE RIDGE FURTHER OVER THE AREA TOMORROW...PUSHING 500MB HEIGHTS TO 598DM. ONCE AGAIN PW HANGS AROUND .5 TO .6 AS MOISTURE REMAINS TRAPPED UNDERNEATH THE RIDGE...SO ISOLATED DRY THUNDERSTORMS ARE POSSIBLE OVER THE HIGHER MTNS TOPS. RIDGE AXIS ORIENTATION BECOMES MORE NORTH TO SOUTH AND SHIFTS EAST SLIGHTLY ON SUNDAY AS THE ABOVE MENTIONED UPPER LEVEL LOW LIFTS NORTH TO OREGON...ALLOWING ADDITIONAL MOISTURE TO BE PULLED INTO THE AREA... AND INCREASING THE CHANCES OF THUNDERSTORMS WITH SOME TRANSITIONING TO WET OVER THE HIGHER TERRAIN. THE HIGHEST MOISTURE VALUES ARE POSITIONED ALONG THE WESTERN EDGE...PUSHING 1 INCH IN WESTERN HUMBOLDT COUNTY. AS FOR THE HEAT ADV...IT STILL LOOKS VALID; THEREFORE NO CHANGES MADE AT THIS TIME. .LONG TERM...SUNDAY NIGHT THROUGH NEXT FRIDAY. HIGH PRESSURE WILL REMAIN STRONG AND CENTERED WEST OF THE 4 CORNERS AREA OF THE COUNTRY THROUGH THURSDAY BEFORE MODELS INDICATE A BREAKDOWN OF THE RIDGE PATTERN. PERSISTENCE WILL BE THE KEY TO TEMPERATURES ALL THROUGH THE PERIOD AND MOISTURE WILL CREEP NORTH THROUGH THE LKN CWFA. 100 DEGREE TEMPERATURES WILL CONTINUE...FAVORING WESTERN NEVADA. HOWEVER DUE TO THE ECCENTRIC NATURE OF THE SYNOPTIC RIDGE...INSTABILITY ASSOCIATED WITH THE MOISTURE INFLUX UNDERNEATH THE RIDGE MAY BE INTERMITTENT WITH A PULSE ATTRIBUTE DUE TO THE OSCILLATIONS OF THE RIDGE AXIS. DO NOT THINK THERE WILL BE OVERNIGHT CONVECTION AT THIS POINT HOWEVER THUNDERSTORMS WITH LITTLE OR NO RAINFALL IS EXPECTED EACH AFTERNOON AND EVENING WITH ISOLATED ACTIVITY POSSIBLE ALL ACROSS THE LKN CWFA. && .AVIATION...VFR CONDITIONS ARE EXPECTED AT KWMC KEKO KELY AND KTPH THROUGH SATURDAY AFTERNOON. NOTE: LIGHTNING SENSOR AT KWMC HAS BEEN TEMPORARILY TURNED OFF TO ELIMINATE FALSE REPORTS OF VCTS. REPAIRS WILL EFFECTED WHEN POSSIBLE. && .FIRE WEATHER...MAINLY HOT AND DRY...HAINES OF 6 IMMINENT. WITH THE RIDGE IN PLACE EXPECTING A MAJOR HEAT WAVE. SOME MOISTURE WILL BE ABLE TO WORK ITS WAY AROUND THE BACK SIDE OF THE RIDGE SUPPORTING ISOLATED DRY THUNDERSTORMS TODAY AND TOMORROW...WITH A TRANSITION TO ISOLATED WET THUNDERSTORMS IN THE HIGHER TERRAIN ON SUNDAY. ANY OF THESE THUNDERSTORMS MAY PRODUCE ERRACTIC AND GUSTY SURFACE WINDS. && .LKN WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 8 PM PDT SUNDAY FOR HUMBOLDT COUNTY-NORTHERN LANDER COUNTY AND NORTHERN EUREKA COUNTY. && $$ 85/92/92
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
313 PM MDT FRI JUN 26 2015 .SYNOPSIS... THOUGH STORMS HAVE BEEN SLOW TO START THIS AFTERNOON...THEY ARE EXPECTED TO INCREASE IN COVERAGE THIS EVENING. STORM MOTIONS WILL BE SLOW AND HEAVY RAIN IS POSSIBLE. THANKS TO THE BACK DOOR FRONT AND ASSOCIATED MOISTURE SURGE FROM TODAY...AN ACTIVE PATTERN IS EXPECTED FOR THE WEEKEND INTO MONDAY WITH WIDESPREAD STORMS PRODUCING HEAVY RAINFALL. AREAS OF FLASH FLOODING WILL BE POSSIBLE. STORM COVERAGE WILL TREND DOWNWARD ON TUESDAY...BUT WILL RAMP BACK UP LATER IN THE WEEK. && .DISCUSSION... BACK DOOR COLD FRONT NUDGED UP TO THE CENTRAL MOUNTAIN CHAIN THIS MORNING...AND HAS BEEN STUCK THERE SINCE. LATEST HRRR SUGGESTS IT MAY BE A FEW HOURS YET UNTIL THE FRONT IS ABLE TO PUSH THROUGH THE GAPS OF THE CENTRAL MOUNTAIN CHAIN...BUT SHOULD OCCUR BY 02-03Z. WHEN THAT DOES OCCUR...COULD SEE SOME STORMS DEVELOP IN THE ABQ METRO AREA. MEANWHILE...DUE TO THE FRONTS EARLY ARRIVAL...IT HAS TAKEN A BIT FOR STORMS TO DEVELOP SINCE AREAS ALONG THE EAST SLOPES HAVE NOT YET REACHED THERE CONVECTIVE TEMPERATURE. THIS WILL OCCUR LATER THIS AFTERNOON...AND STORMS ARE EXPECTED TO ROLL SOUTH OFF THE HIGHER TERRAIN INTO THE CENTRAL HIGH PLAINS. THE HRRR SHOWS STORMS FURTHER EAST...BUT THE NAM MAKES MORE SENSE AT THIS POINT THAT UPSLOPE FLOW AND OROGRAPHICS WILL BE THE MAIN TRIGGER FOR STORMS AND STORM MOTION WILL TAKE THEM SLOWLY SOUTH...IF NOT SW. MOISTURE VALUES LOOK TO BE AROUND 125 PERCENT OF NORMAL...THUS STORMS WILL BE CAPABLE OF PRODUCING HEAVY RAIN. THEREFORE...THE FLASH FLOOD WATCH WILL REMAIN INTACT...BUT CERTAINLY BEARS WATCHING. STORMS SHOULD INITIATE A BIT EARLIER ON SATURDAY...AND FAVOR THE HIGH TERRAIN INITIALLY. STORM MOTIONS WILL BE SLOW ONCE AGAIN... ESPECIALLY ACROSS WESTERN NM. GIVEN HOW WARM IT IS EXPECTED TO BE...WOULD NOT BE SURPRISED TO SEE SOME STRONG OUTFLOW WINDS FROM THESE STORMS. OTHERWISE...HEAVY RAIN WILL BE THE MAIN THREAT. PENDING HOW MODELS TREND TONIGHT...THE MIDNIGHT SHIFT MAY NEED TO ISSUE A FLASH FLOOD WATCH FOR PORTIONS OF WESTERN AND CENTRAL NM. THE ACTIVE PERIOD STILL LOOKS TO CONTINUE THROUGH MONDAY. RELATIVELY SLOW STORM MOTIONS AND HEAVY RAIN POTENTIAL WILL CONTINUE AS PWATS RAISE TO ABOUT 1 INCH OR BETTER ACROSS THE AREA. SOME RELIEF STILL LOOKS TO COME ON TUESDAY AS DRIER AIR ROUNDS THE UPPER HIGH INTO THE STATE. STILL ENOUGH MOISTURE FOR STORMS TO DEVELOP OVER THE MOUNTAINS...BUT OVERALL STORM COVERAGE SHOULD DECREASE SOME. COULD SEE A FEW MORE HAIL PRODUCING STORMS THOUGH VS MAINLY RAIN. MODELS NOW SHOWING A BACK DOOR FRONT/WIND SHIFT ON WEDNESDAY... RATHER THAN THURSDAY...WHICH MAY RESULT IN WEDNESDAY BEING A LITTLE MORE ACTIVE THAT THOUGHT YESTERDAY...ESPECIALLY ACROSS THE NE. A MUCH STRONGER FRONT LOOKS TO ARRIVE NEXT FRIDAY AND SATURDAY...AS A SHORTWAVE TROUGH SLIDES ACROSS COLORADO IN NW FLOW. THIS WILL BE JUST IN TIME FOR 4TH OF JULY FESTIVITIES. STAY TUNED. 34 && .FIRE WEATHER... WETTING SHOWERS AND THUNDERSTORMS WILL CONTINUE TO BE ACTIVE THROUGH THE WEEKEND INTO THE EARLY HALF OF NEXT WEEK. TEMPERATURES WILL RANGE NEAR TO BELOW NORMAL FOLLOWING AN INCREASE IN SURFACE MOISTURE. STORM MOTIONS WILL BE SLOW MOVING INCREASING FLASH FLOODING POTENTIAL...ESPECIALLY EAST OF THE CENTRAL MOUNTAIN CHAIN. THE FOUR CORNERS WILL BE THE LEAST ACTIVE FOR THE NEXT SEVERAL DAYS. TUESDAY AND WEDNESDAY WILL SEE A SLIGHT DOWNTREND IN STORM ACTIVITY AND UPTICK IN TEMPERATURES. ANOTHER BACK DOOR COLD FRONT SHOULD REPLENISH MOISTURE LATER NEXT WEEK. WETTING SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS AFTERNOON INTO THE EVENING ACROSS MUCH OF CENTRAL AND EASTERN NEW MEXICO. THUNDERSTORM COVERAGE WILL BE HIGHER THAN PREVIOUS BECAUSE OF A BACK DOOR FRONT SLOWLY PUSHING SOUTH/WESTWARD TOWARD THE CENTRAL MOUNTAIN CHAIN. A DEEP SURGE IN MOISTURE WILL FOLLOW THE BACK DOOR COLD FRONT AS IT PUSHES WESTWARD INCREASING THUNDERSTORM CHANCES WITH HEAVY RAINFALL. GUSTY GAP WINDS WILL BE EXPECTED LATE TONIGHT WITHIN THE CENTRAL RIO GRANDE VALLEY...ALTHOUGH THE FORECAST TIMING FOR THE GAP WINDS WILL BE A BIT TRICKY SINCE THE FRONT IS MOVING SLOWER THAN ANTICIPATED. STORM MOTION WILL BE SLOW MOVING FROM NORTHEAST TO SOUTHWEST OVER THE NEXT 24 HOUR...INCREASING FLASH FLOODING POTENTIAL FOR AREAS EAST OF THE CENTRAL MOUNTAIN CHAIN TONIGHT...THEN EXPANDING TO CENTRAL AND WESTERN AREAS OVER THE WEEKEND. LOW LEVEL MOISTURE WILL CONTINUE TO PUSH TOWARD THE CONTINENTAL DIVIDE BY SATURDAY INCREASING WET THUNDERSTORMS FOR CENTRAL AND WESTERN NEW MEXICO. THE HIGHER THUNDERSTORM COVERAGE TREND SHOULD CONTINUE INTO EARLY NEXT WEEK. BASED ON THE UPPER HIGH POSITION THE STEERING FLOW SHOULD BE NORTHERLY FOR THE STORMS. TEMPERATURES WILL BE COOLER WITH HIGHER RELATIVE HUMIDITY VALUES. BY TUESDAY....STORMS WILL DOWNTREND A BIT BECAUSE OF DRIER MID LEVEL AIR ROTATING AROUND THE UPPER LEVEL HIGH. THIS DRIER TREND WILL NOT ELIMINATE STORM CHANCES. STORM CHANCES SHOULD INCREASE BY THURSDAY DUE TO A BACK DOOR COLD FRONT. 32 && .AVIATION... 18Z TAF CYCLE SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP. INITIALLY IMPACTING THE MOUNTAINS BUT EVENTUALLY PUSHING OFF AND IMPACTS LOWLAND SITES. TS COVERAGE WILL BE HIGHER TODAY AND THE STORMS HAVE MORE POTENTIAL OF PRODUCING BRIEF MVFR/IFR CONDITIONS. MTN TOP OBSCD WILL ALSO BE POSSIBLE FOR A BRIEF PERIOD OVER MOST OF THE MTN RANGES. MOST OF THE TERMINAL SITES WILL BE IMPACTED BUT USING VCSH/VCTS FOR MOST OF THEM UNTIL THE DEVELOPMENT BECOMES MORE ROBUST. LVS/TCC ARE LIKELY TO BE IMPACTED BY THE HEAVIER RAIN. GUSTY EAST WIND WILL ALSO DEVELOP AND IMPACT ABQ LATER TODAY. SUSPECT GUSTS BETWEEN 35-40 KT BUT COULD BE SLIGHTLY HIGHER FOR A BRIEF PERIOD. TIMING OF THE ONSET OF THIS EAST WIND IS PRETTY TRICKY. AWW WIND SPEEDS DUE TO GUSTY EAST WIND POSSIBLE. LOW CLOUD DEVELOPMENT ALONG THE EAST SLOPES OF THE CENTRAL MTNS ARE POSSIBLE INCLUDING IMPACTS TO LVS BUT THE SIGNAL ISNT AS GOOD RIGHT NOW IN THE MODELS SO WILL HOLD OFF THERE. 50 && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 63 95 63 94 / 5 20 30 10 DULCE........................... 51 87 49 86 / 30 40 50 30 CUBA............................ 53 82 53 83 / 40 60 60 40 GALLUP.......................... 55 91 55 90 / 10 30 30 30 EL MORRO........................ 55 87 53 85 / 40 60 60 70 GRANTS.......................... 57 87 54 87 / 30 50 60 50 QUEMADO......................... 59 88 56 84 / 40 70 60 60 GLENWOOD........................ 56 90 57 87 / 40 60 60 60 CHAMA........................... 48 81 48 82 / 40 60 60 50 LOS ALAMOS...................... 60 82 59 84 / 50 70 60 60 PECOS........................... 56 79 55 81 / 70 60 90 60 CERRO/QUESTA.................... 50 74 50 76 / 60 60 60 60 RED RIVER....................... 46 67 46 69 / 70 70 60 60 ANGEL FIRE...................... 47 71 43 71 / 80 70 60 70 TAOS............................ 51 80 50 82 / 40 50 50 60 MORA............................ 52 74 51 78 / 80 80 70 60 ESPANOLA........................ 58 87 56 89 / 30 40 50 40 SANTA FE........................ 61 80 59 83 / 50 70 70 60 SANTA FE AIRPORT................ 60 85 58 87 / 50 40 60 50 ALBUQUERQUE FOOTHILLS........... 66 88 63 87 / 60 50 70 50 ALBUQUERQUE HEIGHTS............. 68 90 67 90 / 40 30 60 50 ALBUQUERQUE VALLEY.............. 66 92 64 91 / 40 30 60 40 ALBUQUERQUE WEST MESA........... 68 91 65 90 / 40 30 60 30 LOS LUNAS....................... 65 92 63 91 / 30 20 60 30 RIO RANCHO...................... 67 91 64 91 / 40 30 60 50 SOCORRO......................... 66 93 64 91 / 30 20 50 30 SANDIA PARK/CEDAR CREST......... 58 84 58 84 / 70 50 80 60 TIJERAS......................... 60 86 59 86 / 60 50 80 60 MORIARTY/ESTANCIA............... 53 85 53 85 / 70 50 80 50 CLINES CORNERS.................. 56 80 56 82 / 80 60 90 70 GRAN QUIVIRA.................... 59 83 58 82 / 60 50 70 50 CARRIZOZO....................... 62 86 61 85 / 50 40 60 30 RUIDOSO......................... 56 78 56 79 / 70 60 60 50 CAPULIN......................... 56 79 56 81 / 60 40 30 30 RATON........................... 54 81 54 84 / 70 40 30 30 SPRINGER........................ 56 81 55 85 / 70 50 30 30 LAS VEGAS....................... 53 78 53 81 / 80 60 70 40 CLAYTON......................... 60 83 61 90 / 30 30 20 20 ROY............................. 58 79 58 84 / 70 40 40 30 CONCHAS......................... 64 86 64 92 / 70 30 40 20 SANTA ROSA...................... 63 86 62 90 / 80 30 60 20 TUCUMCARI....................... 64 88 65 93 / 50 20 30 20 CLOVIS.......................... 63 83 63 88 / 50 20 40 20 PORTALES........................ 65 85 64 89 / 50 20 40 20 FORT SUMNER..................... 66 85 64 89 / 70 20 60 20 ROSWELL......................... 67 90 66 93 / 60 20 50 20 PICACHO......................... 61 83 60 86 / 70 40 50 20 ELK............................. 59 76 58 79 / 60 50 50 30 && .ABQ WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR THE FOLLOWING ZONES... NMZ515-523-526-528-529-532-533-537>539. && $$ 34
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
622 PM EDT FRI JUN 26 2015 .SYNOPSIS... A WEAK FRONT WILL MOVE SOUTH INTO EASTERN NORTH CAROLINA THIS EVENING, THEN MOVE BACK NORTH TONIGHT. A STRONGER COLD FRONT WILL MOVE THROUGH SUNDAY MORNING THAT WILL BECOME STATIONARY SOUTH OF THE REGION THROUGH MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 610 PM FRI...SEVERAL STRONG TO SEVERE STORMS MOVING THROUGH EASTERN NORTH CAROLINA THIS EARLY EVENING. THESE WILL CONTINUE TO EFFECT EASTERN SECTIONS OVER THE NEXT FEW HOURS. SEVERE THUNDERSTORM WATCH HAS BEEN EXTENDED TO INCLUDE ALL COUNTIES IN FORECAST AREA AND WATERS. AS OF 410 PM FRIDAY...SEVERE THUNDERSTORM WATCH 361 IS NOW IN EFFECT UNTIL 1000 PM EDT. HIGH RESOLUTION AND GLOBAL GUIDANCE INDICATE A WEAK FRONTAL BOUNDARY WILL SHIFT SOUTH ACROSS THE NORTHERN PORTIONS OF THE MHX CWA LATER THIS AFTERNOON. LATEST RUNS OF THE HRRR SUGGESTS AN MCS WILL DEVELOP ACROSS THE NORTHERN PIEDMONT AND MOVE INTO EASTERN NC LATER THIS EVENING. 12Z NAM DOES NOT INDICATE THE MCS FEATURE BUT INDICATES DECENT CONVECTIVE COVERAGE ASSOCIATED WITH THE FRONT SINKING SOUTH INTO EASTERN NC. WE HAVE REACHED CONVECTIVE TEMP ACROSS MANY INLAND LOCATIONS BUT LACK A TRIGGER AND ALSO SUFFER FROM SUBSIDENCE IN THE WAKE OF THIS MORNINGS SHORTWAVE/SQUALL LINE THAT MOVED THROUGH THE OBX. EXPECT CONVECTION TO DEVELOP AFTER 19-20Z DUE TO A COMBINATION OF THE FRONT, SEABREEZE, AND LEFTOVER BOUNDARIES FROM OVERNIGHT CONVECTION. TRIED TO BETTER PINPOINT TIMING OF CONVECTION THIS AFTERNOON AND TRENDED POPS A BIT HIGHER FOR THE HWY 64 AND NORTH AREAS ASSOCIATED WITH THE FRONT SAGGING INTO THE AREA. SOME ISOLATED CONVECTION BEGINNING TO DEVELOP IN RAH CWA SLOWLY PUSHING EAST BUT STRUGGLING TO SEE MUCH DEVELOPMENT ALONG THE SEABREEZE JUST YET. NUCAPS SOUNDINGS MIRROR THE SIGNIFICANT INSTABILITY ACROSS EASTERN NC NOTED IN THE SPC MESOANALYSES, WITH MUCAPE VALUES NEAR 4000 J/KG. WEAK WEST- SOUTHWESTERLY SHEAR 25-30 KNOTS IS FORECAST TO INCREASE, ESPECIALLY ACROSS NORTHERN PORTIONS OF THE CWA, TO 35-45 KNOTS LATE THIS AFTERNOON AND EVENING. ANY STORMS THAT BECOME SEVERE WILL HAVE THE POTENTIAL TO PRODUCE HAIL AND/OR DAMAGING WIND GUSTS. A FEW SITES ARE REPORTING HEAT INDICES ABOVE 105 DEGREES F BUT EXPECT CLOUDS AND CONVECTIVE COVERAGE IN INCREASE WHICH SHOULD DIMINISH TEMPS AND THUS HEAT INDEX VALUES BELOW HEAT ADVISORY THRESHOLDS. TONIGHT...THE FRONT WILL LIFT NORTH OF THE REGION TONIGHT. TIMING AND COVERAGE OF SHOWERS AND THUNDERSTORMS REMAINS TRICKY DUE TO LOSS OF DAYTIME HEATING AND LIFTING MECHANISMS. WILL MAINTAIN CHANCE POPS THROUGH LATE EVENING, THEN LIKELY POPS LATE TONIGHT AS A MOIST SOUTHERLY FLOW OVERTAKES THE REGION WHICH WOULD SUPPORT SLIGHTLY BETTER COVERAGE OF SHOWERS AND THUNDERSTORMS. OVERNIGHT LOWS WILL FALL INTO THE LOW/MID 70S INLAND TO MID/UPPER 70S ALONG THE COAST. && .SHORT TERM /SATURDAY/... AS OF 3 PM FRIDAY...WIDESPREAD SHOWERS AND THUNDERSTORMS EXPECTED ON SATURDAY. AN UPPER TROUGH WILL CONTINUE TO DIG SOUTHEAST INTO THE MIDWESTERN STATES AND INTO THE EASTERN CONUS. A SURFACE LOW WILL STRENGTHEN AS IT MOVES THROUGH THE OHIO RIVER VALLEY SATURDAY. A MOIST/MODERATE SOUTHWESTERLY FLOW WILL PERSIST DURING THE DAY SATURDAY. A VORTMAX/SHORTWAVE EMBEDDED IN THE MEAN NORTHEASTERLY FLOW ALOFT WILL TRAVERSE EASTERN NC DURING THE AFTERNOON HOURS. PWATS INCREASE TO ABOVE 2 INCHES, NEARLY 2 STANDARD DEVIATIONS ABOVE NORMAL FOR JUNE. A SLIGHT RISK FOR SEVERE STORMS CONTINUES FOR SATURDAY WITH THE MAIN THREATS OF DAMAGING WIND GUSTS, HAIL, AND AN ISOLATED TORNADO (GIVEN AN IMPROVING SHEAR PROFILE). MAX TEMPERATURES WILL BUILD INTO THE UPPER 80S TO NEAR 90S INLAND WITH MID 80S ALONG THE COAST, THOUGH TEMP FORECAST REMAINS TRICKY AS SHOWERS/CLOUDS COULD SIGNIFICANTLY IMPACT TEMPERATURES. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... AS OF 310 PM FRIDAY...WET WEEKEND FOLLOWED BY SOME DRIER MORE COMFORTABLE DAYS. THREAT OF RAIN RETURNS BY THE MIDDLE OF NEXT WEEK. SATURDAY NIGHT/SUNDAY...DEEPENING UPPER TROUGH COUPLED WITH A GULF MOISTURE FEED PUSHING PRECIPITABLE WATER TO 2 INCHES OR GREATER...AND A STALLED FRONTAL BOUNDARY TO OUR NORTH WILL LEAD TO WIDESPREAD SHOWERS AND THUNDERSTORMS SATURDAY NIGHT. THE FRONT WILL PUSH OFFSHORE WITH THE UPPER TROUGH AXIS EXITING THE COAST DURING SUNDAY. KEPT A CHANCE OF SHOWERS/THUNDERSTORMS NEAR THE COAST DURING SUNDAY MORNING...BUT DOWNSLOPING FLOW SHOULD QUICKLY CLEAR THINGS OUT SUNDAY AFTERNOON. DRIER AIR FILTERS IN LEADING TO A MUCH MORE COMFORTABLE SUNDAY WITH HIGHS IN THE 80S AND DEWPOINTS DROPPING INTO THE 60S. SUNDAY NIGHT THROUGH TUESDAY...SURFACE HIGH PRESSURE AND LOW UPPER HEIGHTS LEAD TO MORE SEASONABLE WEATHER SUNDAY NIGHT THROUGH TUESDAY WITH NO PRECIPITATION EXPECTED. TEMPERATURES WILL GENERALLY BE IN THE MID/UPPER 80S FOR HIGHS AND MID 60S/LOW 70S FOR LOWS...BEFORE WARMING BACK WELL INTO THE 90S BY TUESDAY. WEDNESDAY THROUGH FRIDAY...A SIMILAR PATTERN TO THIS WEEKEND`S PATTERN WILL SET UP FOR MID/LATE NEXT WEEK. A MID-LEVEL TROUGH WILL DEVELOP AS HEIGHTS LOWER. COUPLED WITH A STALLED FRONTAL BOUNDARY AND DEEP MOISTURE...EXPECT A RETURN OF RAIN CHANCES WEDNESDAY THROUGH THURSDAY NIGHT...WITH SLIGHTLY LOWER POPS FRIDAY AS THE UPPER TROUGH LIFTS OUT. TEMPERATURES WILL BE BACK CLOSE TO SEASONAL NORMALS FOR LATE NEXT WEEK. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH 18Z SATURDAY/... AS OF 130 PM FRI...VFR CONDITIONS EXPECTED DURING MUCH OF THE PERIOD. HOWEVER...WITH SUMMER-TIME HEATING...INSTABILITY IN PLACE AND DISTURBANCES CROSSING THE AREA...THUNDERSTORMS ARE POSSIBLE AGAIN THIS AFTERNOON/EVENING. GIVEN THIS...EXPECT SUB-VFR CONDITIONS COLLOCATED WITH THIS PRECIPITATION ACTIVITY. TIMING THESE SHOWER/STORMS AND THEIR OVERALL EXTENT IS PROVING DIFFICULT AT THIS TIME. AS OF RIGHT NOW...BKN CU FIELD IS DEVELOPING AROUND 4-5 KFT AND EXPECT CLOUD COVER TO LINGER THROUGH THE OVERNIGHT AS ANY CONVECTIVE DEBRIS WORKS ITS WAY EASTWARD. ANTICIPATE WINDS TO BECOME SSW OVERNIGHT. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 330 PM FRIDAY...WIDESPREAD SUB-VFR CONDITIONS ARE LIKELY SATURDAY NIGHT INTO EARLY SUNDAY AS SHOWERS AND THUNDERSTORMS WILL BE NUMEROUS. VFR RETURNS ON SUNDAY AS DOWNSLOPING DRIER AIR MOVES IN WITH GENERALLY DRY WEATHER THROUGH TUESDAY. A CHANCE OF SCATTERED THUNDERSTORMS RETURNS FOR WEDNESDAY...AND SOME BRIEF PERIODS OF LATE DAY MVFR CEILINGS/VSBYS ARE POSSIBLE. && .MARINE... SHORT TERM /THROUGH SATURDAY/ AS OF 620 PM FRI...MAINLY SOUTHWEST FLOW OVER THE COASTAL WATERS SOUTH OF FRONTAL BOUNDARY NEAR OREGON INLET WITH NORTHEASTERLY FLOW NORTH OF THE BOUNDARY. SEAS 4 TO 5 FEET SOUTH OF THIS BOUNDARY WITH 2 TO 3 FEET NORTH OF IT. BOUNDARY EXPECT TO DROP A LITTLE FURTHER SOUTH THIS EVENING BEFORE SHIFTING NORTH OVERNIGHT. SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR ALL THE WATERS THROUGH 10PM WITH ASSOCIATED STORMS. PREV DISC...AS OF 305 PM FRIDAY...LATEST SURFACE AND BUOY DATA INDICATE MOSTLY SOUTHWESTERLY FLOW 15-20 KT WITH SEAS 3-5 FT. CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH TONIGHT DUE TO A FRONTAL BOUNDARY SHIFTING SOUTH ACROSS THE NORTHERN/CENTRAL COASTAL WATERS. THE FRONT SHOULD ACT TO DIMINISH THE SW GRADIENT OVER THE WATERS THROUGH TONIGHT, THEN EXPECT THE GRADIENT TO INCREASE ON SATURDAY AS THE WEAK BOUNDARY SHIFTS NORTH OF THE EASTERN NC WATERS. POOR BOATING CONDITIONS EXPECTED LATE SATURDAY AS SOUTH-SOUTHWESTERLY WINDS INCREASE, BUILDING SEAS 5-8 FT THROUGH SATURDAY NIGHT. SMALL CRAFT ADVISORIES WILL BE ISSUED FOR MOST OF THE EASTERN NC COASTAL WATERS FOR SOUTHWESTERLY WINDS 20-30 KT AND SEAS PEAKING AT 6-9 FT FOR THE OUTER WATERS. LOCAL SWAN/NWPS AND WAVEWATCH IN DECENT AGREEMENT FOR THE SHORT TERM, THOUGH HEDGED CLOSER TO SWAN/NWPS FOR THE NORTHERN WATERS GIVEN ITS BETTER PERFORMANCE IN NEAR SHORE NORTHEASTERLY FLOW. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 330 PM FRIDAY...SMALL CRAFT ADVISORY CONDITIONS WILL BE ONGOING AT THE BEGINNING OF THE EXTENDED PERIOD WITH GRADIENT BEHIND BOUNDARY TO THE NORTH AND BERMUDA HIGH PRESSURE. SOUTHWEST WINDS OF 20 TO 25 KNOTS WITH 25 TO 30 KNOTS CENTRAL WATERS CAN BE EXPECTED WITH SEAS AS HIGH AS 8 FEET. GUSTY WINDS CONTINUE THROUGH SUNDAY BEFORE SUBSIDING AS A COLD FRONT EASES OFFSHORE AND WINDS BECOME MORE W/NW BY LATE SUNDAY THEN NE AT 10 KNOTS OR LESS BY EARLY MONDAY MORNING. THE FRONT QUICKLY WASHES OUT WITH A S/SW WIND FLOW RESUMING MONDAY EVENING. THE GRADIENT TIGHTENS AGAIN WEDNESDAY WITH 15 TO 20 KNOT SOUTHWEST WINDS AND SEAS BUILDING TO AS HIGH AS 6 FEET WEDNESDAY AFTERNOON. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 4 PM TO 11 PM EDT SATURDAY FOR AMZ136-137. SMALL CRAFT ADVISORY FROM 2 PM SATURDAY TO NOON EDT SUNDAY FOR AMZ135. SMALL CRAFT ADVISORY FROM 4 PM SATURDAY TO 5 AM EDT SUNDAY FOR AMZ130-131. SMALL CRAFT ADVISORY FROM 2 PM SATURDAY TO 1 AM EDT MONDAY FOR AMZ152-154. SMALL CRAFT ADVISORY FROM 4 PM SATURDAY TO 10 PM EDT SUNDAY FOR AMZ156-158. SMALL CRAFT ADVISORY FROM 2 PM SATURDAY TO 8 PM EDT SUNDAY FOR AMZ150. && $$ SYNOPSIS...DAG NEAR TERM...CGG/DAG SHORT TERM...DAG LONG TERM...CTC AVIATION...CTC/LEP MARINE...CGG/CTC/DAG
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
411 PM EDT FRI JUN 26 2015 .SYNOPSIS... A WEAK FRONT WILL MOVE SOUTH INTO EASTERN NORTH CAROLINA THIS EVENING, THEN MOVE BACK NORTH TONIGHT. A STRONGER COLD FRONT WILL MOVE THROUGH SUNDAY MORNING THAT WILL BECOME STATIONARY SOUTH OF THE REGION THROUGH MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 410 PM FRIDAY...SEVERE THUNDERSTORM WATCH 361 IS NOW IN EFFECT UNTIL 1000 PM EDT. HIGH RESOLUTION AND GLOBAL GUIDANCE INDICATE A WEAK FRONTAL BOUNDARY WILL SHIFT SOUTH ACROSS THE NORTHERN PORTIONS OF THE MHX CWA LATER THIS AFTERNOON. LATEST RUNS OF THE HRRR SUGGESTS AN MCS WILL DEVELOP ACROSS THE NORTHERN PIEDMONT AND MOVE INTO EASTERN NC LATER THIS EVENING. 12Z NAM DOES NOT INDICATE THE MCS FEATURE BUT INDICATES DECENT CONVECTIVE COVERAGE ASSOCIATED WITH THE FRONT SINKING SOUTH INTO EASTERN NC. WE HAVE REACHED CONVECTIVE TEMP ACROSS MANY INLAND LOCATIONS BUT LACK A TRIGGER AND ALSO SUFFER FROM SUBSIDENCE IN THE WAKE OF THIS MORNINGS SHORTWAVE/SQUALL LINE THAT MOVED THROUGH THE OBX. EXPECT CONVECTION TO DEVELOP AFTER 19-20Z DUE TO A COMBINATION OF THE FRONT, SEABREEZE, AND LEFTOVER BOUNDARIES FROM OVERNIGHT CONVECTION. TRIED TO BETTER PINPOINT TIMING OF CONVECTION THIS AFTERNOON AND TRENDED POPS A BIT HIGHER FOR THE HWY 64 AND NORTH AREAS ASSOCIATED WITH THE FRONT SAGGING INTO THE AREA. SOME ISOLATED CONVECTION BEGINNING TO DEVELOP IN RAH CWA SLOWLY PUSHING EAST BUT STRUGGLING TO SEE MUCH DEVELOPMENT ALONG THE SEABREEZE JUST YET. NUCAPS SOUNDINGS MIRROR THE SIGNIFICANT INSTABILITY ACROSS EASTERN NC NOTED IN THE SPC MESOANALYSES, WITH MUCAPE VALUES NEAR 4000 J/KG. WEAK WEST- SOUTHWESTERLY SHEAR 25-30 KNOTS IS FORECAST TO INCREASE, ESPECIALLY ACROSS NORTHERN PORTIONS OF THE CWA, TO 35-45 KNOTS LATE THIS AFTERNOON AND EVENING. ANY STORMS THAT BECOME SEVERE WILL HAVE THE POTENTIAL TO PRODUCE HAIL AND/OR DAMAGING WIND GUSTS. A FEW SITES ARE REPORTING HEAT INDICES ABOVE 105 DEGREES F BUT EXPECT CLOUDS AND CONVECTIVE COVERAGE IN INCREASE WHICH SHOULD DIMINISH TEMPS AND THUS HEAT INDEX VALUES BELOW HEAT ADVISORY THRESHOLDS. TONIGHT...THE FRONT WILL LIFT NORTH OF THE REGION TONIGHT. TIMING AND COVERAGE OF SHOWERS AND THUNDERSTORMS REMAINS TRICKY DUE TO LOSS OF DAYTIME HEATING AND LIFTING MECHANISMS. WILL MAINTAIN CHANCE POPS THROUGH LATE EVENING, THEN LIKELY POPS LATE TONIGHT AS A MOIST SOUTHERLY FLOW OVERTAKES THE REGION WHICH WOULD SUPPORT SLIGHTLY BETTER COVERAGE OF SHOWERS AND THUNDERSTORMS. OVERNIGHT LOWS WILL FALL INTO THE LOW/MID 70S INLAND TO MID/UPPER 70S ALONG THE COAST. && .SHORT TERM /SATURDAY/... AS OF 3 PM FRIDAY...WIDESPREAD SHOWERS AND THUNDERSTORMS EXPECTED ON SATURDAY. AN UPPER TROUGH WILL CONTINUE TO DIG SOUTHEAST INTO THE MIDWESTERN STATES AND INTO THE EASTERN CONUS. A SURFACE LOW WILL STRENGTHEN AS IT MOVES THROUGH THE OHIO RIVER VALLEY SATURDAY. A MOIST/MODERATE SOUTHWESTERLY FLOW WILL PERSIST DURING THE DAY SATURDAY. A VORTMAX/SHORTWAVE EMBEDDED IN THE MEAN NORTHEASTERLY FLOW ALOFT WILL TRAVERSE EASTERN NC DURING THE AFTERNOON HOURS. PWATS INCREASE TO ABOVE 2 INCHES, NEARLY 2 STANDARD DEVIATIONS ABOVE NORMAL FOR JUNE. A SLIGHT RISK FOR SEVERE STORMS CONTINUES FOR SATURDAY WITH THE MAIN THREATS OF DAMAGING WIND GUSTS, HAIL, AND AN ISOLATED TORNADO (GIVEN AN IMPROVING SHEAR PROFILE). MAX TEMPERATURES WILL BUILD INTO THE UPPER 80S TO NEAR 90S INLAND WITH MID 80S ALONG THE COAST, THOUGH TEMP FORECAST REMAINS TRICKY AS SHOWERS/CLOUDS COULD SIGNIFICANTLY IMPACT TEMPERATURES. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... AS OF 310 PM FRIDAY...WET WEEKEND FOLLOWED BY SOME DRIER MORE COMFORTABLE DAYS. THREAT OF RAIN RETURNS BY THE MIDDLE OF NEXT WEEK. SATURDAY NIGHT/SUNDAY...DEEPENING UPPER TROUGH COUPLED WITH A GULF MOISTURE FEED PUSHING PRECIPITABLE WATER TO 2 INCHES OR GREATER...AND A STALLED FRONTAL BOUNDARY TO OUR NORTH WILL LEAD TO WIDESPREAD SHOWERS AND THUNDERSTORMS SATURDAY NIGHT. THE FRONT WILL PUSH OFFSHORE WITH THE UPPER TROUGH AXIS EXITING THE COAST DURING SUNDAY. KEPT A CHANCE OF SHOWERS/THUNDERSTORMS NEAR THE COAST DURING SUNDAY MORNING...BUT DOWNSLOPING FLOW SHOULD QUICKLY CLEAR THINGS OUT SUNDAY AFTERNOON. DRIER AIR FILTERS IN LEADING TO A MUCH MORE COMFORTABLE SUNDAY WITH HIGHS IN THE 80S AND DEWPOINTS DROPPING INTO THE 60S. SUNDAY NIGHT THROUGH TUESDAY...SURFACE HIGH PRESSURE AND LOW UPPER HEIGHTS LEAD TO MORE SEASONABLE WEATHER SUNDAY NIGHT THROUGH TUESDAY WITH NO PRECIPITATION EXPECTED. TEMPERATURES WILL GENERALLY BE IN THE MID/UPPER 80S FOR HIGHS AND MID 60S/LOW 70S FOR LOWS...BEFORE WARMING BACK WELL INTO THE 90S BY TUESDAY. WEDNESDAY THROUGH FRIDAY...A SIMILAR PATTERN TO THIS WEEKEND`S PATTERN WILL SET UP FOR MID/LATE NEXT WEEK. A MID-LEVEL TROUGH WILL DEVELOP AS HEIGHTS LOWER. COUPLED WITH A STALLED FRONTAL BOUNDARY AND DEEP MOISTURE...EXPECT A RETURN OF RAIN CHANCES WEDNESDAY THROUGH THURSDAY NIGHT...WITH SLIGHTLY LOWER POPS FRIDAY AS THE UPPER TROUGH LIFTS OUT. TEMPERATURES WILL BE BACK CLOSE TO SEASONAL NORMALS FOR LATE NEXT WEEK. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH 18Z SATURDAY/... AS OF 130 PM FRI...VFR CONDITIONS EXPECTED DURING MUCH OF THE PERIOD. HOWEVER...WITH SUMMER-TIME HEATING...INSTABILITY IN PLACE AND DISTURBANCES CROSSING THE AREA...THUNDERSTORMS ARE POSSIBLE AGAIN THIS AFTERNOON/EVENING. GIVEN THIS...EXPECT SUB-VFR CONDITIONS COLLOCATED WITH THIS PRECIPITATION ACTIVITY. TIMING THESE SHOWER/STORMS AND THEIR OVERALL EXTENT IS PROVING DIFFICULT AT THIS TIME. AS OF RIGHT NOW...BKN CU FIELD IS DEVELOPING AROUND 4-5 KFT AND EXPECT CLOUD COVER TO LINGER THROUGH THE OVERNIGHT AS ANY CONVECTIVE DEBRIS WORKS ITS WAY EASTWARD. ANTICIPATE WINDS TO BECOME SSW OVERNIGHT. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 330 PM FRIDAY...WIDESPREAD SUB-VFR CONDITIONS ARE LIKELY SATURDAY NIGHT INTO EARLY SUNDAY AS SHOWERS AND THUNDERSTORMS WILL BE NUMEROUS. VFR RETURNS ON SUNDAY AS DOWNSLOPING DRIER AIR MOVES IN WITH GENERALLY DRY WEATHER THROUGH TUESDAY. A CHANCE OF SCATTERED THUNDERSTORMS RETURNS FOR WEDNESDAY...AND SOME BRIEF PERIODS OF LATE DAY MVFR CEILINGS/VSBYS ARE POSSIBLE. && .MARINE... SHORT TERM /THROUGH SATURDAY/ AS OF 305 PM FRIDAY...LATEST SURFACE AND BUOY DATA INDICATE MOSTLY SOUTHWESTERLY FLOW 15-20 KT WITH SEAS 3-5 FT. CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH TONIGHT DUE TO A FRONTAL BOUNDARY SHIFTING SOUTH ACROSS THE NORTHERN/CENTRAL COASTAL WATERS. THE FRONT SHOULD ACT TO DIMINISH THE SW GRADIENT OVER THE WATERS THROUGH TONIGHT, THEN EXPECT THE GRADIENT TO INCREASE ON SATURDAY AS THE WEAK BOUNDARY SHIFTS NORTH OF THE EASTERN NC WATERS. POOR BOATING CONDITIONS EXPECTED LATE SATURDAY AS SOUTH-SOUTHWESTERLY WINDS INCREASE, BUILDING SEAS 5-8 FT THROUGH SATURDAY NIGHT. SMALL CRAFT ADVISORIES WILL BE ISSUED FOR MOST OF THE EASTERN NC COASTAL WATERS FOR SOUTHWESTERLY WINDS 20-30 KT AND SEAS PEAKING AT 6-9 FT FOR THE OUTER WATERS. LOCAL SWAN/NWPS AND WAVEWATCH IN DECENT AGREEMENT FOR THE SHORT TERM, THOUGH HEDGED CLOSER TO SWAN/NWPS FOR THE NORTHERN WATERS GIVEN ITS BETTER PERFORMANCE IN NEAR SHORE NORTHEASTERLY FLOW. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 330 PM FRIDAY...SMALL CRAFT ADVISORY CONDITIONS WILL BE ONGOING AT THE BEGINNING OF THE EXTENDED PERIOD WITH GRADIENT BEHIND BOUNDARY TO THE NORTH AND BERMUDA HIGH PRESSURE. SOUTHWEST WINDS OF 20 TO 25 KNOTS WITH 25 TO 30 KNOTS CENTRAL WATERS CAN BE EXPECTED WITH SEAS AS HIGH AS 8 FEET. GUSTY WINDS CONTINUE THROUGH SUNDAY BEFORE SUBSIDING AS A COLD FRONT EASES OFFSHORE AND WINDS BECOME MORE W/NW BY LATE SUNDAY THEN NE AT 10 KNOTS OR LESS BY EARLY MONDAY MORNING. THE FRONT QUICKLY WASHES OUT WITH A S/SW WIND FLOW RESUMING MONDAY EVENING. THE GRADIENT TIGHTENS AGAIN WEDNESDAY WITH 15 TO 20 KNOT SOUTHWEST WINDS AND SEAS BUILDING TO AS HIGH AS 6 FEET WEDNESDAY AFTERNOON. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 4 PM TO 11 PM EDT SATURDAY FOR AMZ136-137. SMALL CRAFT ADVISORY FROM 2 PM SATURDAY TO NOON EDT SUNDAY FOR AMZ135. SMALL CRAFT ADVISORY FROM 4 PM SATURDAY TO 5 AM EDT SUNDAY FOR AMZ130-131. SMALL CRAFT ADVISORY FROM 2 PM SATURDAY TO 1 AM EDT MONDAY FOR AMZ152-154. SMALL CRAFT ADVISORY FROM 4 PM SATURDAY TO 10 PM EDT SUNDAY FOR AMZ156-158. SMALL CRAFT ADVISORY FROM 2 PM SATURDAY TO 8 PM EDT SUNDAY FOR AMZ150. && $$ SYNOPSIS...DAG NEAR TERM...DAG SHORT TERM...DAG LONG TERM...CTC AVIATION...CTC/LEP MARINE...CTC/DAG
AREA FORECAST DISCUSSION
NWS RALEIGH NC
259 PM EDT FRI JUN 26 2015 .SYNOPSIS...AN UPPER LEVEL TROUGH DIGGING SOUTHEAST INTO THE OHIO VALLEY TODAY WILL DEEPEN ALONG THE EASTERN SEABOARD OVER THE WEEKEND. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 300 PM FRIDAY... THINGS HAVING A REALLY HARD TIME GETTING GOING THIS AFTERNOON AS SUBSIDENCE BEHIND THIS MORNINGS WAVE OF CONVECTION ACROSS THE VA BORDER IS DELAYING THE ONSET OF AFTERNOON SHOWERS AND THUNDERSTORMS. CONVECTIVE ALLOWING MODELS ALREADY HEAD SHOWERS IN THE TRIAD BY 18Z WHICH IS NOT CLOSE TO HAPPENING AT THIS POINT AND RAP MODEL VORTICITY NOW SHOWS ANY SHORTWAVE ACTIVITY REMAINING NORTHEAST OF THE AREA FOR THE MOST PART. LOOKING AT VARIOUS PARAMETERS ON THE SPC MESOSCALE ANALYSIS THERE ARE STILL SEVERAL THINGS STILL GOING WELL FOR THE CHANCES FOR CONVECTION THIS AFTERNOON INCLUDING INCREASING SHEAR FROM THE NORTH...DECENT INSTABILITY...AND UPWARDS OF 2 INCHES OF PRECIPITABLE WATER. THE PROBLEM WE MAY HAVE HOWEVER...IS GETTING THINGS TO LINE UP. WHILE SHEAR IS BEST IN THE NORTH...DCAPE IS BEST IN THE SOUTH. WHILE THE BEST VORTICITY WOULD BE IN THE NORTHEAST...THE STRONGEST LAPSE RATES WILL BE IN THE SOUTHWEST. WITH THE SHORTWAVE MOVING OFF TO THE NORTHEAST...ANY FOCUS FOR CONVECTION WILL BE ALONG THE RESIDUAL FRONT AND A POTENTIAL DIFFERENTIAL HEATING BOUNDARY. SURFACE OBS CURRENTLY SHOW 80S IN THE NORTHEAST WITH LOW 90S ACROSS THE US 64 CORRIDOR BUT MID 90S ACROSS THE SOUTHERN TIER OF COUNTIES. HERE ARE THE TAKEAWAYS. FIRST...CONVECTION THIS AFTERNOON IS STILL POSSIBLE AND SEVERE WEATHER IS ALSO POSSIBLE AS SUGGESTED BY THE SPC SLIGHT RISK AREA. HOWEVER...COVERAGE AND STRENGTH OF STORMS SHOULD NOT BE AS STRONG AS YESTERDAY. THE EVOLUTION OF THE CUMULUS FIELD ON SATELLITE SUGGEST THAT THE FRONTAL BOUNDARY WILL BE THE MOST LIKELY SPOT FOR CONVECTION THIS AFTERNOON WHICH IS ROUGHLY ALONG THE US 64 CORRIDOR. MAIN THREATS TODAY WILL BE FROM WIND AND POTENTIALLY SOME HAIL AS A SECONDARY THREAT AS WELL AS FLOODING IN ANY SLOW MOVING OR TRAINING CELLS. TIMING WILL BE LATER THIS AFTERNOON INTO THE EVENING. FOR TONIGHT...ATTENTION WILL TURN TO THE WEST AND AN APPROACHING COLD FRONTAL SYSTEM. AS THE SYSTEM MOVES CLOSER TO THE AREA...A PRE- FRONTAL TROUGH WILL FIRST MOVE THROUGH THE AREA DURING THE OVERNIGHT AREAS FROM SOUTHWEST TO NORTHEAST. THIS COULD BRING A ROUND OF CONVECTION INTO THE TRIAD AROUND 6Z AND PUSHING THROUGH THE NORTHEASTERN PART OF THE CWA BY 9Z. AFTER THIS MOVES THROUGH...EXPECT A LULL IN PRECIPITATION THROUGH SUNRISE. LOWS MAINLY IN THE LOWER 70S WITH SOME FOG/STRATUS POSSIBLE BEFORE DAYBREAK. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... AS OF 300 PM FRIDAY... CENTRAL NC IS UNDER A SLIGHT RISK FOR SEVERE WEATHER ON SATURDAY AS AN UPPER LEVEL TROUGH BEGINS TO DIG INTO THE SOUTHEAST AND A SURFACE LOW AMPLIFIES OVER THE OHIO VALLEY. THE ATTENDANT COLD FRONT IS PROGGED TO SWING THROUGH THE CWA ON SATURDAY EVENING. PRIOR TO THAT HAPPENING...DIURNAL DESTABILIZATION AND INCREASING MOISTURE TRANSPORT WILL HELP CONVECTION TO BEGIN DEVELOPING ACROSS THE CWA BY EARLY AFTERNOON. WHAT WILL START AS SCATTERED SHOWERS AND THUNDERSTORMS WILL GRADUALLY BECOME MORE ORGANIZED INTO CLUSTERS AND SMALL LINE SEGMENTS WHICH WILL BEGIN TO MOVE EAST AS FORCING FROM THE FRONT GETS CLOSER. BY EVENING...THE MAIN COLD FRONT WILL BEGIN TO MOVE THROUGH THE AREA SUPPORTING A QUASI-LINEAR CONVECTIVE SYSTEM THAT WILL BE CAPABLE OF PRODUCING SEVERE WEATHER...MOST LIKELY IN THE FORM OF DAMAGING WINDS ALONG BOWING SEGMENTS OF THE LINE. CONVECTIVE ALLOWING MODELS HAVE BEEN CONSISTENTLY SHOWING A SIMILAR EVOLUTION OF THE CONVECTION AND THIS IS SUPPORTED BY THE LARGER SCALE MODELS SO CONFIDENCE IS FAIRLY HIGH AT THIS TIME. IN ADDITION TO DAMAGING WINDS...SECONDARY THREATS WILL BE FROM LARGE HAIL AND POTENTIALLY A BRIEF TORNADO...MOST LIKELY ALONG THE LINE OF CONVECTION. THE SYSTEM WILL MOVE THROUGH FAIRLY QUICKLY SO FLOODING DOES NOT LOOK PARTICULARLY LIKELY BUT URBAN AREAS AND PLACES WHERE ANTECEDENT CONDITIONS ARE FAIRLY WET COULD BECOME SUBJECT TO FLOODING. TIMING OF THE SYSTEM SHOULD HAVE CONVECTION STARTING ACROSS THE CWA AROUND 18Z...WITH THE MAIN FRONTAL BOUNDARY MOVING THROUGH THE TRIAD AROUND 00Z ON SUNDAY WITH THE TRIANGLE AFFECTED JUST BEFORE MIDNIGHT AND OUT OF THE EASTERN PORTION OF THE AREA BY 6Z ON SUNDAY. WITH MORE CLOUD COVER BY AFTERNOON...HIGHS ON SATURDAY WILL ONLY GET INTO THE MID 80S ACROSS THE NORTH TO NEAR 90 IN THE SOUTH. LOWS ON SUNDAY MORNING WILL BE DEPENDENT UPON THE TIMING OF THE FRONT WITH THE TRIAD MOST LIKELY IN THE LOWER 60S TO LOWER 70S IN THE EAST. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AS OF 1240 PM FRIDAY... A LINGERING SHOWER IS POSSIBLE IN THE FAR SOUTHEASTERN CWFA SUNDAY MORNING...OTHERWISE COOLER AND DRIER AIR WILL FILTER IN RAPIDLY BEHIND THE FRONT. HIGHS WILL TOP OUT MOSTLY IN THE MID 80S...A COUPLE OF DEGREES BELOW NORMAL. AN UPPER TROF IN THE WAKE OF THIS SYSTEM WILL SETTLE OVER THE EASTERN CONUS AND PERSIST FOR THE REMAINDER OF THE WEEK. MONDAY LOOKS DRY AND SEASONABLE...WITH LEE SURFACE TROF SETTING UP THE PREDOMINANTLY WESTERLY FLOW. HIGHS WILL BEGIN THE INEVITABLE CREEP UPWARDS...REACHING THE MID TO UPPER 80S AFTER MORNING LOWS FROM 60 TO 65. WARMING CONTINUES TUESDAY WITH HIGHS IN THE UPPER 80S TO LOWER 90S...AND THE SURFACE REFLECTION OF AN INITIAL SHORT WAVE DIGGING INTO THE UPPER TROF WILL MOVE ACROSS THE AREA TUESDAY NIGHT. MOISTURE WILL BE LIMITED...BUT INSTABILITY WILL BE SUFFICIENT FOR AT LEAST WIDELY SCATTERED CONVECTION INTO THE EVENING. A SECOND FRONT NUDGES SOUTH AND STALLS IN THE VICINITY OF THE CAROLINAS ON WEDNESDAY...WITH A SERIES OF DISTURBANCES IN THE NORTHWEST FLOW PROVIDING US WITH A HIGH CONFIDENCE IN THE OCCURRENCE OF CONVECTION...BUT LOW CONFIDENCE IN THE TIMING OTHER THAN COVERAGE WHICH WILL BE MAXIMIZED DURING FAVORABLE DIURNAL HEATING. HIGHS WEDNESDAY THROUGH FRIDAY WILL PROBABLY BE A SHADE WARMER THAN NORMAL...UPPER 80S NORTH TO LOW 90S ACROSS THE SOUTHERN TIER. MORNING LOWS WILL BE WITHIN A DEGREE OR TWO OF 70. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 200 PM FRIDAY 24 HOUR TAF PERIOD: VFR CONDITIONS ACROSS THE AREA AS EARLIER SHOWER ACTIVITY HAS DISSIPATED AND LEFT SOME SUBSIDENCE IN ITS WAKE. AS A RESULT...CONVECTION HAS BEEN A LITTLE SLOW TO GET GOING THIS AFTERNOON. NOT SURE IF RECOVERY WILL BEGIN EARLY ENOUGH TO THREATEN THE TRIAD AS THE NEXT WAVE MOVES THROUGH SO HAVE TAKEN THUNDER OUT OF THE TAFS THERE FOR THIS AFTERNOON BUT KEPT IT IN AT KRDU AND KRWI AS WE WILL CONTINUE TO DESTABILIZE THIS AFTERNOON AND SHOULD REALIZE CONVECTION A BIT LATER. PARAMETERS ARE STILL GOOD FOR SEVERE WX SO THERE IS A RISK FOR SOME STRONG WIND GUSTS IN THE VICINITY OF SHOWERS AND THUNDERSTORMS. OTHERWISE WINDS WILL BE LIGHT AND VARIABLE STRATOCUMULUS ACROSS THE AREA. OVERNIGHT TONIGHT A FIRST WAVE AHEAD OF AN APPROACHING COLD FRONT WILL MOVE THROUGH DURING THE EARLY MORNING HOURS...BRINING A CHANCE FOR SHOWERS AND THUNDERSTORMS TO ALL SITES BEFORE MOVING NORTHEAST OUT OF THE AREA. A BREAK IN PRECIPITATION NEAR SUNRISE WILL GIVE WAY TO MUCH BETTER CHANCES FOR SHOWERS...THUNDERSTORMS...A GOOD CHANCE OF SEVERE WEATHER SATURDAY AFTERNOON IN THE WEST THROUGH THE EARLY MORNING HOURS ON SUNDAY IN THE EAST. LONG TERM: CONDITIONS SHOULD RETURN TO VFR ON SUNDAY WITH THE FIRST HALF OF THE WORK WEEK LOOKING VERY NICE WITH A MORE UNSETTLED PATTERN RETURN FOR THE SECOND HALF OF THE WEEK. && .CLIMATE... REC DAY MAX YR RDU RECORDS 06/26 102 1952 GSO RECORDS 06/26 102 1914 FAY RECORDS 06/26 101 1951 && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...NP NEAR TERM...ELLIS SHORT TERM...ELLIS LONG TERM...MLM AVIATION...ELLIS CLIMATE...BLAES
AREA FORECAST DISCUSSION
NWS BISMARCK ND
504 PM CDT FRI JUN 26 2015 .UPDATE... ISSUED AT 504 PM CDT FRI JUN 26 2015 CONFINED POPS TO THE MORE DENSE CU FIELDS...SOUTHWEST AND EAST...ALSO WHERE RADAR RETURNS ARE AT. OTHERWISE UPDATES WERE MINOR FOR THIS FORECAST ISSUANCE. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 238 PM CDT FRI JUN 26 2015 THUNDERSTORM POTENTIAL THIS AFTERNOON THROUGH TONIGHT AND A WARM SATURDAY HIGHLIGHT THE SHORT TERM FORECAST. THE 18 UTC RAP ANALYSIS DEPICTS 800-1500 J/KG OF ML CAPE FROM THE JAMES RIVER VALLEY THROUGH THE TURTLE MOUNTAINS AND INTO THE SOURIS BASIN...WITH DEEP LAYER SHEAR ON THE ORDER OF 20-25 KTS. RADAR TRENDS THROUGH 1940 UTC DEPICT ISOLATED CONVECTION INITIATING ACROSS THESE AREAS...WITH A FEW WEAK IMPULSES EMBEDDED IN NORTHWEST FLOW ALOFT. CANNOT RULE OUT A STRONG STORM WITH SMALL HAIL AND GUSTY WINDS...HOWEVER...ANY SEVERE THREAT AT THIS TIME APPEARS LOW. THESE AFTERNOON STORMS ARE EXPECTED TO FADE WITH SUNSET. ANOTHER ROUND OF STORMS ASSOCIATED WITH A WAVE ACROSS CENTRAL SASKATCHEWAN THIS AFTERNOON MAY PROPAGATE INTO NORTHERN NORTH DAKOTA TONIGHT. THESE STORMS ARE EXPECTED TO BE NON-SEVERE. ACROSS SOUTH CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY...A SIMILAR FOG SETUP TONIGHT IS EXPECTED WHICH PRODUCED FOG THIS MORNING FOR THESE AREAS. THUS...ADDED FOG FOR LATE TONIGHT INTO SATURDAY MORNING FOR THESE LOCATIONS. FOR SATURDAY...A WARM DAY IS FORECAST AHEAD OF A WEAK COLD FRONT THAT WILL PROPAGATE ACROSS WESTERN AND CENTRAL NORTH DAKOTA FROM SOUTHERN CANADA THROUGH THE AFTERNOON. WITH GOOD MIXING AND INSOLATION...WIDESPREAD HIGHS IN THE UPPER 80S TO LOWER 90S ARE EXPECTED...ON THE WARMER EDGE OF THE 12 UTC DETERMINISTIC AND STATISTICAL SUITES. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 238 PM CDT FRI JUN 26 2015 DETERMINISTIC AND ENSEMBLE MODELS INDICATE MAINLY DRY CONDITIONS TO BEGIN THE LONG TERM PERIOD. ALTHOUGH AN ISOLATED THUNDERSTORM CAN NOT BE COMPLETELY RULED OUT DUE TO DAYTIME HEATING. UPPER LEVEL RIDGING WILL BE THE DOMINANT FEATURE IN THE FORECAST SUNDAY AND MONDAY. SHORTWAVE ENERGY BEGINS TO MAKE ITS WAY THROUGH THE MEAN UPPER LEVEL RIDGE BEGINNING MONDAY NIGHT. WILL UTILIZE THE MODEL BLEND IN REGARDS TO POPS WHICH BRINGS SMALL CHANCES OF THUNDERSTORMS ACROSS AT LEAST PARTS OF WESTERN AND CENTRAL NORTH DAKOTA MONDAY NIGHT THROUGH FRIDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 238 PM CDT FRI JUN 26 2015 VFR CONDITIONS ARE EXPECTED TODAY WITH SURFACE HIGH PRESSURE. ISOLATED THUNDERSTORMS MAY BE POSSIBLE IN THE KJMS VICINITY THIS AFTERNOON...AND KMOT THIS AFTERNOON INTO TONIGHT. FOG WILL ONCE AGAIN BE POSSIBLE TONIGHT FOR KBIS/KJMS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...NH SHORT TERM...AYD LONG TERM...TWH AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
252 PM CDT FRI JUN 26 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 238 PM CDT FRI JUN 26 2015 THUNDERSTORM POTENTIAL THIS AFTERNOON THROUGH TONIGHT AND A WARM SATURDAY HIGHLIGHT THE SHORT TERM FORECAST. THE 18 UTC RAP ANALYSIS DEPICTS 800-1500 J/KG OF ML CAPE FROM THE JAMES RIVER VALLEY THROUGH THE TURTLE MOUNTAINS AND INTO THE SOURIS BASIN...WITH DEEP LAYER SHEAR ON THE ORDER OF 20-25 KTS. RADAR TRENDS THROUGH 1940 UTC DEPICT ISOLATED CONVECTION INITIATING ACROSS THESE AREAS...WITH A FEW WEAK IMPULSES EMBEDDED IN NORTHWEST FLOW ALOFT. CANNOT RULE OUT A STRONG STORM WITH SMALL HAIL AND GUSTY WINDS...HOWEVER...ANY SEVERE THREAT AT THIS TIME APPEARS LOW. THESE AFTERNOON STORMS ARE EXPECTED TO FADE WITH SUNSET. ANOTHER ROUND OF STORMS ASSOCIATED WITH A WAVE ACROSS CENTRAL SASKATCHEWAN THIS AFTERNOON MAY PROPAGATE INTO NORTHERN NORTH DAKOTA TONIGHT. THESE STORMS ARE EXPECTED TO BE NON-SEVERE. ACROSS SOUTH CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY...A SIMILAR FOG SETUP TONIGHT IS EXPECTED WHICH PRODUCED FOG THIS MORNING FOR THESE AREAS. THUS...ADDED FOG FOR LATE TONIGHT INTO SATURDAY MORNING FOR THESE LOCATIONS. FOR SATURDAY...A WARM DAY IS FORECAST AHEAD OF A WEAK COLD FRONT THAT WILL PROPAGATE ACROSS WESTERN AND CENTRAL NORTH DAKOTA FROM SOUTHERN CANADA THROUGH THE AFTERNOON. WITH GOOD MIXING AND INSOLATION...WIDESPREAD HIGHS IN THE UPPER 80S TO LOWER 90S ARE EXPECTED...ON THE WARMER EDGE OF THE 12 UTC DETERMINISTIC AND STATISTICAL SUITES. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 238 PM CDT FRI JUN 26 2015 DETERMINISTIC AND ENSEMBLE MODELS INDICATE MAINLY DRY CONDITIONS TO BEGIN THE LONG TERM PERIOD. ALTHOUGH AN ISOLATED THUNDERSTORM CAN NOT BE COMPLETELY RULED OUT DUE TO DAYTIME HEATING. UPPER LEVEL RIDGING WILL BE THE DOMINANT FEATURE IN THE FORECAST SUNDAY AND MONDAY. SHORTWAVE ENERGY BEGINS TO MAKE ITS WAY THROUGH THE MEAN UPPER LEVEL RIDGE BEGINNING MONDAY NIGHT. WILL UTILIZE THE MODEL BLEND IN REGARDS TO POPS WHICH BRINGS SMALL CHANCES OF THUNDERSTORMS ACROSS AT LEAST PARTS OF WESTERN AND CENTRAL NORTH DAKOTA MONDAY NIGHT THROUGH FRIDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 238 PM CDT FRI JUN 26 2015 VFR CONDITIONS ARE EXPECTED TODAY WITH SURFACE HIGH PRESSURE. ISOLATED THUNDERSTORMS MAY BE POSSIBLE IN THE KJMS VICINITY THIS AFTERNOON...AND KMOT THIS AFTERNOON INTO TONIGHT. FOG WILL ONCE AGAIN BE POSSIBLE TONIGHT FOR KBIS/KJMS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...AYD LONG TERM...TWH AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
101 PM CDT FRI JUN 26 2015 .UPDATE... ISSUED AT 1255 PM CDT FRI JUN 26 2015 NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE...AS THE 15-17 UTC HRRR ITERATIONS CONTINUE TO SUPPORT AFTERNOON ISOLATED TO SCATTERED THUNDERSTORM ACTIVITY FROM THE TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY AND POINTS EAST...WHERE CUMULUS FIELDS CONTINUE TO BUILD ON VISIBLE SATELLITE. UPDATE ISSUED AT 829 AM CDT FRI JUN 26 2015 GIVEN A TIME LAGGED ENSEMBLE OF THE 09-11 UTC HRRR ITERATIONS AND A CONSENSUS OF THE 00 UTC WRF-ARW/NMM AND 06 UTC NAM...DECREASED THE OVERALL MENTION OF ISOLATED THUNDERSTORMS ACROSS CENTRAL NORTH DAKOTA TODAY...CONFINING THE MENTION TO PRIMARILY THE TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY. UPDATE ISSUED AT 639 AM CDT FRI JUN 26 2015 MAIN ADJUSTMENT TO THE FORECAST WAS TO ADD ISOLATED SHOWERS IN THE JAMES RIVER VALLEY THIS MORNING. KBIS WSR-88D SHOWS A FEW SHOWERS IN THAT AREA...AND THE LATEST HRRR HINTS THAT THEY COULD PERSIST FOR A FEW HOURS. PATCHY FOG WAS LEFT IN PLACE WITH A FEW SPOTS ACROSS WESTERN AND CENTRAL NORTH DAKOTA REPORTING REDUCED VISIBILITIES. DID NOT ADJUST POPS FOR THIS AFTERNOON WITH ISOLATED TO SCATTERED SHOWERS / THUNDERSTORMS STILL SUPPORTED IN THE HRRR AND 26.06Z NAM. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 308 AM CDT FRI JUN 26 2015 THE LATEST WATER VAPOR IMAGERY DEPICTS A NORTHWEST FLOW INTO NORTH DAKOTA WITH THE NEXT SIGNIFICANT UPSTREAM SHORTWAVE TROUGH WORKING THROUGH CENTRAL BRITISH COLUMBIA. THIS SHORTWAVE TROUGH WILL MOVE EAST THEN PIVOT SOUTHEAST AS IT SLIDES INTO SOUTH CENTRAL MANITOBA 12Z SATURDAY. IN RESPONSE...A SURFACE LOW PRESSURE AND ASSOCIATED COLD FRONT WILL EMERGE OVER SOUTHERN ALBERTA/SASKATCHEWAN INTO NORTHERN MONTANA FRIDAY EVENING/NIGHT. THE COLD FRONT WILL ENTER NORTHWESTERN NORTH DAKOTA AROUND 12Z SATURDAY. IN ADVANCE OF THIS SYSTEM FOR TODAY(FRIDAY)...A COUPLE OF SUBTLE SHORTWAVES STRETCHING FROM SOUTHERN/EASTERN SASKATCHEWAN INTO CENTRAL NORTH DAKOTA WILL HELP PRODUCE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON/EVENING. CAPE/SHEAR VALUES REMAIN WEAK AND THE LATEST HIGH RESOLUTION MODELS...ARW WEST/NMM WEST/HRRR...PORTRAY ISOLATED TO SCATTERED SHOWERS/THUNDERSTORMS...MAINLY FROM THE TURTLE MOUNTAINS SOUTH INTO THE JAMES RIVER VALLEY. THE GLOBAL MODELS EXTEND PRECIPITATION CHANCES ACROSS CENTRAL NORTH DAKOTA WITH THE FAR WEST REMAINING DRY. USED A BLEND OF THE HIGH RESOLUTION AND GLOBAL SUITE FOR POPS TODAY...AS THE SHORTWAVES INTERACT WITH THE WEAK INSTABILITY ALREADY IN PLACE THIS AFTERNOON AND EVENING. THE ISOLATED SHOWERS/THUNDERSTORMS WILL CONTINUE FRIDAY NIGHT AS A WEAK LOW LEVEL/850MB JET BRIEFLY DEVELOPS FRIDAY EVENING ADVECTING IN MOISTURE AHEAD OF THE AFOREMENTIONED SHORTWAVE TROUGH AND SURFACE FRONT. HOWEVER NOT EXPECTING ANY SEVERE WEATHER AT THIS TIME...AND SPC CONVECTIVE OUTLOOK HIGHLIGHTS GENERAL THUNDERSTORMS FRIDAY/FRIDAY NIGHT. HIGH TEMPERATURES FRIDAY AFTERNOON WILL BE IN THE LOW TO MID 80S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 308 AM CDT FRI JUN 26 2015 A WEAK COLD FRONT MOVING ACROSS THE NORTHERN PLAINS COULD BRING A CHANCE OF THUNDERSTORMS ON SATURDAY. THE MAIN CHANCES SHOULD BE IN THE EASTERN PART OF THE FORECAST AREA WITH THE BOUNDARY REACHING THAT AREA SATURDAY AFTERNOON DURING PEAK HEATING. THE THUNDERSTORM CHANCES ARE EXPECTED TO DIMINISH IN THE EVENING AS THE BOUNDARY EXITS THE REGION. DRY WEATHER IS EXPECTED SUNDAY AND MONDAY WITH H5 HEIGHTS BUILDING ACROSS NORTH DAKOTA. BY MONDAY NIGHT...THE FIRST IN A SERIES OF UPPER WAVES MOVES ACROSS IN NORTHWESTERLY FLOW ALOFT. WILL FOLLOW THE MODEL BLEND IN REGARDS TO POPS WHICH BRINGS SMALL CHANCES OF THUNDERSTORMS ACROSS AT LEAST PARTS OF WESTERN AND CENTRAL NORTH DAKOTA FROM MONDAY NIGHT AND BEYOND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1255 PM CDT FRI JUN 26 2015 VFR CONDITIONS ARE EXPECTED TODAY WITH SURFACE HIGH PRESSURE. ISOLATED THUNDERSTORMS MAY BE POSSIBLE IN THE KJMS VICINITY THIS AFTERNOON. FOG WILL ONCE AGAIN BE POSSIBLE TONIGHT FOR KBIS/KJMS. GIVEN UNCERTAINTY...WILL LEAVE THE MENTION OUT FOR NOW. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...KS LONG TERM...CK AVIATION...AYD
AREA FORECAST DISCUSSION
NWS MEDFORD OR
235 PM PDT FRI JUN 26 2015 .DISCUSSION...DISCUSSION...THE LATEST VISIBLE IMAGE IS STARTING TO SHOW SOME CU DEVELOP OVER THE CASCADES...SISKIYOUS...EASTERN SIKSYOU...MODOC AND HIGHER TERRAIN IN LAKE AND KLAMATH COUNTY. THE SPC MESOSCALE ANALYSIS SHOWS CAPE VALUES INCREASING ALONG THE CASCADES AND WESTERN SIKSYOU COUNTY THROUGH SOUTHWEST OREGON. INTERESTING IS THE CIN VALUES HAVE TRENDED LOWER IN THE LAST FEW HOURS. THE SOUNDING PUT OUR CONVECTIVE TEMPERATURE AT 93 DEGREES AND IT WAS NOT MUCH LONGER AFTER WE REACHED AND EXCEEDED THAT IS WHEN THE CU HAS STARTED TO POP UP. THE LATEST HRRR REFLECTIVITY MODEL PUTS MOST OF THE RETURNS ALONG AND EAST OF THE CASCADES AND A FEW IN SOUTHWEST OREGON. THE LATEST RAP SHOWS A SIMILAR SOLUTION, BUT WITH MORE "QPF" IN SOUTHWEST OREGON. ALSO THE RAP SHOWS A SHORTWAVE MOVING NORTHWEST INTO SOUTHWEST OREGON EARLY THIS EVENING AND WITH CONDITIONS ALREADY UNSTABLE WITH INCREASING MID LEVEL MOISTURE, COULD SET THE TABLE FOR ISOLATED THUNDERSTORMS IN THIS AREA. MEANWHILE INSTABILITY WILL BE GREATER ALONG THE CASCADES AND SISKIYOUS...SO WE COULD SEE MORE FREQUENT THUNDERSTORMS IN THESE AREAS. UNFORTUNATELY THE MODEL SOUNDINGS HAVE AN INVERTED "V" PROFILE WHICH MEANS THAT STORMS COULD PRODUCE LITTLE OR NO PRECIPITATION, SO WE`LL KEEP DRY THUNDERSTORMS IN THE FORECAST. OF NOTE SPC HAS A MARGINAL RISK IN THE CENTER OF OUR CWA AND THE POTENTIAL FOR SCATTERED DRY THUNDERSTORMS FOR A GOOD CHUNK OF OUR AREA TONIGHT. OF BIG CONCERN WILL BE THE POTENTIAL FOR NEW STARTS FROM LIGHTNING. THIS WILL BE ADDRESSED IN MORE DETAIL IN THE FORE WEATHER SECTION. TODAY AND SATURDAY WILL BE THE HOTTEST DAYS WITH RECORD HIGHS LIKELY TO BE SET. THE FORECAST HAS BEEN CONSISTENT IN EXPECTING VALLEY HIGHS DURING THE NEXT TWO DAYS OF 95 TO 110 DEGREES ON THE WEST SIDE OF THE CASCADES THIS AFTERNOON AND 92 TO 102 ON THE EAST SIDE. THE ONLY THING THAT COULD LIMIT THE AMOUNT OF HEATING SATURDAY AND SUNDAY WILL BE CLOUD COVER...EVEN THEN WE`LL BE HOT, BUT NOT AS HOT AS TODAY. PWATS WILL GRADUALLY INCREASE TO 0.75 TO 1.00 INCHES. THE LEAST AMOUNT OF RAINFALL WITH THUNDERSTORMS WILL BE IN THOSE THAT DEVELOP SOUTH AND EAST OF SOUTHWEST OREGON. COVERAGE OF STORMS WILL INCREASE DURING THE EVENING WITH A PRIMARY FOCUS FOR NORTHWARD MOVING THUNDERSTORMS FROM THE FOOTHILLS OF THE CASCADES AND CASCADES ITSELF AND SISKIYOUS. HOWEVER THE RAP SHOWS A SHORTWAVE MOVING INTO SOUTHWEST OREGON THIS EVENING, SO THERE COULD BE A SECONDARY FOCUS IN JOSEPHINE...CURRY...COOS AND PARTS OF DOUGLAS COUNTY. THESE STORMS WILL BE MOVING AT 10 TO 15 KNOTS. EMBEDDED SHORTWAVES IN THE SOUTHERLY FLOW ALOFT ARE EXPECTED TO KEEP THUNDERSTORMS GOING OVERNIGHT INTO SATURDAY MORNING WITH THE HIGHEST PROBABILITY ALONG THE CASCADES. THUNDERSTORMS CONTINUE SATURDAY AND THERE IS A BETTER CHANCE WE COULD GET SOME WETTING RAINS FROM THIS, BUT THEY COULD BE FASTER MOVING. WE EXPECT A GREATER COVERAGE OF THUNDERSTORMS SATURDAY OVERING A GOOD PORTION OF THE CWA, PEAKING IN THE AFTERNOON AND EARLY EVENING. THERE IS CONCERN FOR ANOTHER SURGE IN MID LEVEL MOISTURE AND INSTABILITY SATURDAY NIGHT INTO SUNDAY. THE GFS AND EC ARE IN FAIRLY GOOD AGREEMENT SHOWING ANOTHER SURGE OF MID LEVEL MOISTURE AND SHORTWAVES MOVING INTO SOUTHWEST OREGON AS THE UPPER TROUGH MOVES NORTH ALONG THE CALIFORNIA COAST. AT THE SAME TIME 850 LI`S WILL GET INTO THE NEGATIVE TERRITORY. SO THERE IS CONCERN WE COULD SEE ANOTHER ROUND OF NOCTURNAL STORMS IN PARTS OF JOSEPHINE...JACKSON...CURRY...COOS AND DOUGLAS COUNTY AND CASCADES AND SISKIYOUS SATURDAY NIGHT INTO SUNDAY MORNING. THEREFORE HAVE INCREASED POPS IN THESE AREAS. PWATS ARE EXPECTED TO BE HIGHER, SO WE THINK STORMS WILL PRODUCE SOME RAINFALL. HOWEVER 700-500MB WIND SPEED IS EXPECTED TO BE BETWEEN 20-25 KTS, SO THEY WILL BE FASTER MOVING. THE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE TIMING OF THE TROUGH AXIS SUNDAY. IT WILL STILL BE TO OUR SOUTH SUNDAY, BUT THE MID LEVELS WILL GRADUALLY DRY OUT IN SOUTHWEST OREGON AND WESTERN SISKIYOU COUNTY LATE SUNDAY AFTERNOON...THEREFORE WE COULD BE LOOKING AT ANOTHER ACTIVE DAY WITH SLOW IMPROVEMENT IN THE ABOVE MENTIONED AREAS LATE SUNDAY AFTERNOON. BY SUNDAY NIGHT, THE FOCUS FOR THUNDERSTORMS WILL SHIFT EAST WITH THE BEST CHANCE FOR STORMS ALONG AND EAST OF THE CASCADES. THE TROUGH AXIS WILL MOVE NORTHEAST SUNDAY NIGHT INTO MONDAY AND THE FOCUS FOR THUNDERSTORMS WILL SHRINK AND BE MAINLY CONFINED TO KLAMATH AND LAKE COUNTY. IT LOOKS LIKE WE COULD CATCH A BREAK IN THE ACTION TUESDAY AS WE GET A MORE STABLE SOUTHWEST FLOW. I LEFT IN A SLIGHT CHANCE FOR THUNDERSTORMS IN THE SOUTHEAST PORTION OF THE FORECAST AREA, BUT THERE IS PLENTY OF DRYING AT THE MID LEVELS, SO WOULD NOT BE SURPRISED IF WE DON`T GET ANYTHING. THE MODELS SHOW THE RIDGE RE BUILDING WESTWARD BEYOND TUESDAY, BUT THE HIGHEST MID LEVEL MOISTURE AND INSTABILITY SHOULD BE MOSTLY ALONG AND EAST OF THE CASCADES, THUS HAVE TRIMMED BACK THE POPS AND THREAT OF THUNDERSTORMS TO MODOC AND SOUTHEAST LAKE AND KLAMATH COUNTY. -PETRUCELLI && .AVIATION...FOR THE 26/18Z TAF CYCLE...LOW CLOUDS WILL CONTINUE TO HUG THE COAST NORTH OF CAPE BLANCO WITH MAINLY IFR CONDITIONS...AND OCCASIONAL SCATTERING TO VFR CONDITIONS. NORTH BEND SHOULD BE IN AND OUT OF THE CEILINGS DURING THE MORNING...AND IN THE AFTERNOON THE TERMINAL IS MORE LIKELY TO BE SOCKED IN...REMAINING THAT WAY OVERNIGHT. ELSEWHERE VFR CONDITIONS WILL PREVAIL. LATE THIS AFTERNOON INTO THE EVENING ISOLATED THUNDERSTORMS ARE EXPECTED ALONG AND NEAR THE OREGON CASCADES...THE UPPER KLAMATH BASIN...AND WESTERN SISKIYOU COUNTY. THE BEST CHANCE OF THUNDERSTORMS IS IN THE 00-06Z TIME FRAME FOR THIS TAF CYCLE AT KLMT AND KRBG. THESE STORMS ARE EXPECTED TO BE HIGH-BASED, DRY, AND THEREFORE COULD CONTAIN GUSTY OUTFLOW WINDS AND POSSIBLY ISOLATED MICROBURSTS. SK/SPILDE && .MARINE...UPDATED 200 PM PDT FRIDAY 26 JUNE 2015...A THERMAL TROUGH WILL BRING GALE FORCE NORTH WINDS SOUTH OF CAPE BLANCO THIS AFTERNOON AND EVENING WITH VERY STEEP WIND WAVE DOMINATED SEAS. AS IS TYPICAL WITH THERMAL TROUGH WIND PATTERNS...CONFIDENCE IS ONLY MODERATE ON EXACTLY HOW CLOSE TO SHORE THE GALES REACH...WITH THE FORECAST REFLECTING GALES BEYOND 10 NM FROM SHORE TODAY. THE THERMAL TROUGH WILL WEAKEN AND BOTH WINDS AND SEAS ARE EXPECTED TO LOWER THIS WEEKEND. THUNDERSTORMS ARE POSSIBLE TONIGHT INTO SATURDAY MORNING WITHIN 10 NM FROM SHORE. THE THERMAL TROUGH WILL THEN STRENGTHEN AGAIN MONDAY AND TUESDAY WITH CONDITIONS AT LEAST HAZARDOUS TO SMALL CRAFT. STRONGEST WINDS AND SEAS WILL AGAIN BE SOUTH OF CAPE BLANCO. /FB && .FIRE WEATHER...UPDATED 200 PM PDT FRIDAY 26 JUNE 2015...ONLY MINOR CHANGES TO THE AREAS COVERED BY THE RED FLAG WARNING THROUGH THE WEEKEND. THE CONVECTIVE TEMPERATURE HAS FINALLY BEEN REACHED WITH CUMULUS DEVELOPING FROM THE SOUTH AS THE CAP OVER THE REGION IS BEING BROKEN. WIDESPREAD INSTABILITY IS OVER THE REGION BUT WITH THE STRONGEST THETA E CONVERGENCE OVER WESTERN SISKIYOU COUNTY...THE MOUNT SHASTA AREA AND UP THE CASCADES AND THEN DOWN THE RIDGES BETWEEN 624 AND 625 THIS SHOULD BE WHERE THE MOST CONVECTION WILL DEVELOP. THE 700 MB WINDS ARE FROM THE SSE AND WILL BE BORDERLINE STRENGTH TO PUSH THE THUNDERSTORMS THAT DO DEVELOP OFF OF THE HIGHER TERRAIN AND INTO THE WEST SIDE OF OREGON. WITH THE DRY LAYER BENEATH AT LOWER LEVEL THE BASES OF THE STORMS SHOULD GENERALLY BE ABOVE TEN THOUSAND FEET WITH MUCH OF THE PRECIPITATION EVAPORATING BEFORE REACHING THE GROUND EARLY ON IN THE AFTERNOON THROUGH EARLY EVENING. ELEVATED INSTABILITY REMAINS OVERNIGHT WITH A STRONG SHORT WAVE MOVING THROUGH OVERNIGHT. WITH THIS A CONTINUATION OF THUNDERSTORMS OVERNIGHT TONIGHT SEEMS A GOOD POSSIBILITY. THE MOISTURE FLOW CONTINUES TO POUR INTO THE REGION WITH PRECIPITABLE WATER VALUES INCREASING TO A LITTLE OVER 1.2 INCHES. THERE SHOULD BE ENOUGH CLEARING AFTER THE SHORT WAVE BRINGS CONVECTION THROUGH THE REGION AROUND 6-9Z TO ALLOW FOR SUFFICIENT SURFACE HEATING TO REACH THE LEVEL OF INSTABILITY INDICATED AND MOST OF THE REGION FROM THE COASTAL RANGES ACROSS THE EAST SIDE SHOULD BE AT LEAST CLOSE TO SOME CONVECTION TOMORROW AS WELL. TOMORROW NIGHT WILL ALSO SEE THE COMBINATION OF ELEVATED CONVECTION WITH A SHORT WAVE MOVING THROUGH THE AREA...BRINGING ANOTHER NIGHT OF AT LEAST ISOLATED THUNDERSTORMS. THE PATTERN CONTINUES SUNDAY...BUT A DRY MID LAYER MOVES INTO THE WEST SIDE WITH 700-500 RH IN THE 20S INHIBITING THUNDERSTORM DEVELOPMENT IN THAT AREA. THE OVERALL PATTERN REMAINS THROUGH MUCH OF NEXT WEEK...WITH ADJUSTMENTS TO THE AREAS OF THUNDERSTORMS BEING THE MAIN ADJUSTER TO CONFIDENCE. -SVEN && .MFR WATCHES/WARNINGS/ADVISORIES... OR... RED FLAG WARNING UNTIL 11 PM PDT SUNDAY FOR ORZ615>625. HEAT ADVISORY UNTIL 5 AM PDT SUNDAY FOR ORZ023. HEAT ADVISORY UNTIL 5 AM PDT SUNDAY FOR ORZ024-026. CA...RED FLAG WARNING UNTIL 11 PM PDT SUNDAY FOR CAZ280>282-284-285. HEAT ADVISORY UNTIL 5 AM PDT SUNDAY FOR CAZ080-081. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT THIS EVENING FOR PZZ350-356-370-376. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT SATURDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT SATURDAY FOR PZZ370-376. GALE WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376. HAZARDOUS SEAS WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376. $$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
1027 AM PDT FRI JUN 26 2015 .UPDATED AVIATION DISCUSSION. .DISCUSSION...CURRENT VISIBLE IMAGE SHOWS CLEAR SKIES WITH SOME LIGHT HAZE FROM THE FIRES IN CALIFORNIA MOVING NORTHWEST INTO THE AREA AS THE UPPER FLOW HAS NOT BECOME SOUTH TO SOUTHEAST. MARINE STRATUS REMAIN NORTH OF CAPE BLANCO AND IN THE COQUILLE VALLEY, BUT THAT WILL BURN OFF IN THE NEXT FEW HOURS. THE WATER VAPOR IMAGE SHOWS A WEAK UPPER LOW OFF THE CALIFORNIA COAST AND MOISTURE ALREADY STARTING TO MOVE NORTH INTO CENTRAL NEVADA. THIS WILL CONTINUE TO MOVE NORTH TO NORTHWEST DURING THE DAY AND WE`LL START TO SEE CUMULUS DEVELOPING OVER THE CASCADES AND NORTHERN CAL AROUND MIDDAY. HOWEVER THE ATMOSPHERE IS EXPECTED TO BE RATHER DRY AND THE MID LEVEL MOISTURE IS NOT EXPECTED TO INCREASE UNTIL LATER THIS AFTERNOON, THUS HAVE REMOVED ISOLATED THUNDERSTORMS FOR LATE MORNING AND AFTERNOON. HOWEVER THEY ARE STILL A CONCERN STARTING MID AFTERNOON. SOME GUIDANCE SUGGEST THE BEST CHANCE FOR STORMS MAY END UP OVER THE CASCADES AND EASTSIDE, BUT FIND THIS SUSPECT GIVEN WE`LL STILL BE IN A MOIST SOUTH TO SOUTHEAST FLOW AND THE RAP SHOWS PVA MOVING THROUGH SOUTHWEST OREGON IN THE EVENING WITH 850 LI`S IN THE NEGATIVE. ALSO MID LEVEL LAPSE RATES ARE EXPECTED TO INCREASE AND MODEL SOUNDINGS SHOW ENOUGH INSTABILITY TO KEEP ISOLATED STORMS IN THE FORECAST TONIGHT WEST OF THE CASCADES. IT STILL LOOKS LIKE SATURDAY WILL BE THE MOST ACTIVE WITH A GOOD CHUNK OF THE AREA UNDER THE THREAT OF STORMS WITH MORE FREQUENT STORMS POSSIBLE. THE BULK OF THE ACTION WILL GRADUALLY SHIFT EAST SUNDAY AS THE UPPER TROUGH MOVES NORTH SQUEEZING THE RIDGE DOWN A LITTLE. -PETRUCELLI && .AVIATION...FOR THE 26/18Z TAF CYCLE...LOW CLOUDS WILL CONTINUE TO HUG THE COAST NORTH OF CAPE BLANCO WITH MAINLY IFR CONDITIONS...AND OCCASIONAL SCATTERING TO VFR CONDITIONS. NORTH BEND SHOULD BE IN AND OUT OF THE CEILINGS DURING THE MORNING...AND IN THE AFTERNOON THE TERMINAL IS MORE LIKELY TO BE SOCKED IN...REMAINING THAT WAY OVERNIGHT. ELSEWHERE VFR CONDITIONS WILL PREVAIL. LATE THIS AFTERNOON INTO THE EVENING ISOLATED THUNDERSTORMS ARE EXPECTED ALONG AND NEAR THE OREGON CASCADES...THE UPPER KLAMATH BASIN...AND WESTERN SISKIYOU COUNTY. THE BEST CHANCE OF THUNDERSTORMS IS IN THE 00-06Z TIME FRAME FOR THIS TAF CYCLE AT KLMT AND KRBG. THESE STORMS ARE EXPECTED TO BE HIGH-BASED, DRY, AND THEREFORE COULD CONTAIN GUSTY OUTFLOW WINDS AND POSSIBLY ISOLATED MICROBURSTS. SK/SPILDE && .MARINE....MARINE...UPDATED 900 AM PDT FRIDAY 26 JUNE 2015...A THERMAL TROUGH WILL BRING GALE FORCE NORTH WINDS SOUTH OF CAPE BLANCO TODAY WITH VERY STEEP WIND WAVE DOMINATED SEAS. AS IS TYPICAL WITH THERMAL TROUGH WIND PATTERNS...CONFIDENCE IS ONLY MODERATE ON EXACTLY HOW CLOSE TO SHORE THE GALES REACH...WITH THE FORECAST REFLECTING GALES BEYOND 10 NM FROM SHORE TODAY. THE THERMAL TROUGH WILL WEAKEN AND BOTH WINDS AND SEAS ARE EXPECTED TO LOWER THIS WEEKEND. THUNDERSTORMS ARE POSSIBLE TONIGHT INTO SATURDAY MORNING WITHIN 10 NM FROM SHORE. THE THERMAL TROUGH WILL THEN STRENGTHEN AGAIN MONDAY AND TUESDAY WITH CONDITIONS AT LEAST HAZARDOUS TO SMALL CRAFT. STRONGEST WINDS AND SEAS WILL AGAIN BE SOUTH OF CAPE BLANCO. SK/SPILDE && FIRE WEATHER...UPDATED 400 AM PDT FRIDAY 26 JUNE 2015...HAVE MADE NO CHANGES WITH RESPECT TO THE RED FLAG WARNING (RFWMFR) HEADLINES IN PLACE ACROSS THE AREA BEGINNING LATER THIS AFTERNOON. MODELS CONTINUE TO SHOW MOISTURE INCREASING IN THE SOUTH TO SOUTHEAST FLOW DEVELOPING ALOFT IN A CORRIDOR BETWEEN AN UPPER LOW OFFSHORE AND THE MID LEVEL RIDGE CENTERED OVER THE GREAT BASIN. THIS IS A FAVORABLE THUNDERSTORM PATTERN AND THIS CORRIDOR IS AIMED RIGHT OVER SW OREGON/NORCAL, WHERE ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP LATER THIS AFTERNOON AND EVENING. THIS PATTERN WILL PERSIST FRIDAY NIGHT THROUGH MUCH OF THE WEEKEND AS THE UPPER LOW SLOWLY MOVES NORTHWARD ALONG THE CALIFORNIA COAST. CONFIDENCE ON THE EXACT LOCATION OF STORMS REMAINS FAIRLY LOW AS MID AND UPPER LEVEL SUPPORT FOR STORMS (SHORTWAVES) IS WEAK, BUT WITH STRONG HEATING AND THE RESULTING INSTABILITY OVER ABNORMALLY DRY FUELS ACROSS A LARGE PART OF THE AREA (NEAR-RECORD DRYNESS ALONG THE COAST)...THE THREAT FOR ABUNDANT LIGHTNING IS A BIG CONCERN FOR INITIAL ATTACK. STORMS SHOULD INITIATE OVER THE HIGHER TERRAIN THIS AFTERNOON, THEN PROPAGATE NORTHWESTWARD WITH TIME THIS EVENING AND OVERNIGHT. A STRONG MOISTURE GRADIENT WILL EXIST ALONG THE CASCADES. STORMS OVER THE EAST SIDE SHOULD BE FAIRLY DRY, WHERE PWS ARE GENERALLY LESS THAN 0.75 OF AN INCH. PWS OF 1.00-1.25 INCHES EXIST ALONG AND WEST OF THE CASCADES WHERE STORMS THAT DEVELOP SHOULD BE COMPARABLY WETTER. ANY STORMS WILL HAVE THE ABILITY TO PRODUCE GUSTY OUTFLOWS THAT COULD CAUSE NEW FIRE STARTS TO SPREAD QUICKLY. BY SATURDAY AND SATURDAY NIGHT, ADDITIONAL SHORT WAVE ACTIVITY WILL MOVE NORTH-NORTHWESTWARD INTO THE AREA AND MOISTURE SHOULD BE ADEQUATE FOR MOSTLY WET STORMS. WE STILL EXPECT SATURDAY TO BE THE MOST ACTIVE DAY (AT LEAST IN TERMS OF COVERAGE OF STORMS). BY SUNDAY, THE MODELS SUGGEST THE STRONGEST SHORT WAVE WILL MOVE THROUGH THE AREA. BUT THE AREA OF GREATEST INSTABILITY WILL SLOWLY SHIFT EASTWARD, SO AREAS ALONG AND EAST OF THE CASCADES WILL BE THE AREAS THAT LIKELY SEE THE MOST COVERAGE OF STORMS. FIRE ZONES 615 AND 618 SHOULD BE IN THE CLEAR, WHILE ISOLATED STORMS MAY STILL FORM INLAND OVER THE WEST SIDE. IT WILL BE A CLOSE CALL FOR FIRE ZONE 619. THE RIDGE AXIS SHIFTS EAST MONDAY AS THE UPPER TROUGH AXIS MOVES THROUGH AND THUNDERSTORM THREAT SHOULD BE MOSTLY CONFINED TO PORTIONS OF FIRE ZONES 624 AND 625. SPILDE && .PREV DISCUSSION... /ISSUED 0850 AM PDT FRI JUN 26 2015/ UPDATED MARINE DISCUSSION. DISCUSSION...A HOT AND UNSTABLE AIR MASS WILL PERSIST OVER THE REGION DURING THE NEXT WEEK. LOW PRESSURE OFFSHORE FROM CALIFORNIA AND HIGH PRESSURE CENTERED IN THE GREAT BASIN ARE THE MAIN UPPER LEVEL FEATURES AFFECTING OUR WEATHER IN THE SHORT TERM WITH THAT STRONG RIDGING LIKELY TO PERSIST THROUGH THE WEEK. TODAY AND SATURDAY WILL BE THE HOTTEST DAYS WITH RECORD HIGHS LIKELY TO BE SET. BUT, THE FOLLOWING FIVE DAYS WILL NOT BE THAT MUCH COOLER. THE FORECAST HAS BEEN CONSISTENT IN EXPECTING VALLEY HIGHS DURING THE NEXT TWO DAYS OF 95 TO 110 DEGREES ON THE WEST SIDE OF THE CASCADES THIS AFTERNOON AND 92 TO 102 ON THE EAST SIDE. THE OTHER MAIN FOCUS OF THE FORECAST IS THE DEVELOPMENT OF THUNDERSTORMS WITH THE POTENTIAL FOR LIGHTNING TO CAUSE NEW FIRES. ATMOSPHERIC MOISTURE LEVELS WILL GRADUALLY INCREASE WITH PRECIPITABLE WATER AMOUNTS THAT WERE AT 0.50 TO 0.75 INCHES YESTERDAY TO RISE TO 0.75 TO 1.00 INCHES TODAY. THE LEAST AMOUNT OF RAINFALL WITH THUNDERSTORMS WILL BE IN THOSE THAT DEVELOP SOUTH AND EAST OF SOUTHWEST OREGON. AN EARLY AFTERNOON THUNDERSTORM CANNOT BE COMPLETELY RULED OUT, BUT THERE IS GOOD MODEL AGREEMENT BETWEEN THE NAM AND THE SREF AND RAP SHORT TERM MODELS THAT THE FIRST THUNDERSTORMS WILL DEVELOP AROUND 3 PM OVER THE HIGHER TERRAIN FROM WESTERN SISKIYOU COUNTY TO THE SISKIYOU MOUNTAINS AND CASCADES EASTWARD. COVERAGE OF STORMS WILL INCREASE DURING THE EVENING WITH A PRIMARY FOCUS FOR NORTHWARD MOVING THUNDERSTORMS FROM THE FOOTHILLS OF THE CASCADES (IN EASTERN PORTIONS OF JACKSON AND DOUGLAS COUNTIES) EASTWARD. THAT WILL NOT BE THE EXCLUSIVE LOCATION OF THUNDERSTORMS, JUST THE LIKELY FOCUS. THESE STORMS WILL BE MOVING AT 10 TO 15 KNOTS. EMBEDDED SHORTWAVES IN THE SOUTHERLY FLOW ALOFT ARE EXPECTED TO KEEP THUNDERSTORMS GOING OVERNIGHT INTO SATURDAY MORNING WITH THE HIGHEST PROBABILITY ALONG THE CASCADES. THERE IS UNCERTAINTY IN THE TRACK AND STRENGTH OF SHORTWAVES AS THE GFS HAS A FOCUS DURING THE EVENING HOURS BEFORE LIFTING THE MAJORITY OF ACTIVITY INTO NORTHERN OREGON WHILE THE NAM SOLUTION WOULD ACTUALLY INCREASE THE NUMBER OF THUNDERSTORMS IN OUR AREA DURING THE OVERNIGHT HOURS WHILE SPREADING THEM IN A SOUTHEAST RATHER THAN SOUTH FLOW ALOFT TO THE COAST AND COASTAL WATERS. THUNDERSTORMS ON SATURDAY WILL PRODUCE MORE RAINFALL BUT THEY WILL ALSO BE FASTER MOVING AT 15 TO 25 KNOTS. THUNDERSTORM COVERAGE IS EXPECTED TO BE AT ITS PEAK DURING SATURDAY AFTERNOON AND EVENING. THE PERSISTENT PATTERN WILL ONCE AGAIN PRODUCE NOCTURNAL THUNDERSTORMS SATURDAY NIGHT INTO SUNDAY MORNING. THERE IS UNCERTAINTY IN THE TIMING AND TRACK OF THE OFFSHORE LOW. THE NAM IS FASTER THAN THE GFS BUT BOTH HAVE IT MOVING NORTH TO THE SOUTHERN OREGON COAST ON SUNDAY. THIS WILL BRING IN SLIGHTLY COOLER AIR AND EVENTUALLY KICK THE CONVECTIVE ACTIVITY TO THE EAST WITH WEST SIDE OF THE CASCADES FOCUS OF THUNDERSTORMS ON SUNDAY MORNING SHIFTING TO THE EAST SIDE FOR SUNDAY EVENING INTO MONDAY. THUNDERSTORMS ON SUNDAY WILL HAVE A HIGHER PROBABILITY OF PRODUCING SEVERE WIND GUSTS. THE TROUGH WITH A MUCH DRIER AIR MASS WILL BE IN PLACE OVER THE PACIFIC NORTHWEST ON MONDAY. THUS, A SLIGHT CHANCE OF THUNDERSTORMS WILL BE NEARLY LIMITED TO ONLY LAKE AND MODOC COUNTIES. MONDAY NIGHT SHOULD TRANSPIRE WITHOUT THUNDERSTORMS. RIDGING FROM THE GREAT BASIN IS EXPECTED TO REBUILD INTO OUR AREA TUESDAY FOR THE START OF ANOTHER WARMING TREND INTO THURSDAY. THIS WILL ALSO SEND HIGHER AMOUNTS OF MOISTURE INTO THE EAST SIDE ON TUESDAY THAT WILL EXPAND FARTHER WEST...TO THE WEST SIDE ON WEDNESDAY FOR ANOTHER EPISODE OF A SLIGHT CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS. THE PROBABILITY WILL BE THE LOWEST FOR THE COAST AND DOUGLAS COUNTY. FORECAST UNCERTAINTY INCREASES BEYOND WEDNESDAY AS THE ECMWF MODEL INDICATES A STRONG TROUGH MOVING INTO THE PACIFIC NORTHWEST WILL FINALLY CHANGE THE PATTERN AND BRING SOME COOLING FOR THE END OF THE WEEK, BUT THE GFS IS PERSISTENT AND LEAVES THE HOT GREAT BASIN RIDGE IN COMMAND. FOR NOW, WE WILL LEAN TOWARD PERSISTENCE. && .MFR WATCHES/WARNINGS/ADVISORIES... OR... RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT SUNDAY FOR ORZ615>625. HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 5 AM PDT SUNDAY FOR ORZ023. HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 5 AM PDT SUNDAY FOR ORZ024-026. CA...RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT SUNDAY FOR CAZ280-281-284-285. HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 5 AM PDT SUNDAY FOR CAZ080-081. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT THIS EVENING FOR PZZ350-356-370-376. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT SATURDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT SATURDAY FOR PZZ370-376. GALE WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376. HAZARDOUS SEAS WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376. $$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
936 AM PDT FRI JUN 26 2015 .DISCUSSION...CURRENT VISIBLE IMAGE SHOWS CLEAR SKIES WITH SOME LIGHT HAZE FROM THE FIRES IN CALIFORNIA MOVING NORTHWEST INTO THE AREA AS THE UPPER FLOW HAS NOT BECOME SOUTH TO SOUTHEAST. MARINE STRATUS REMAIN NORTH OF CAPE BLANCO AND IN THE COQUILLE VALLEY, BUT THAT WILL BURN OFF IN THE NEXT FEW HOURS. THE WATER VAPOR IMAGE SHOWS A WEAK UPPER LOW OFF THE CALIFORNIA COAST AND MOISTURE ALREADY STARTING TO MOVE NORTH INTO CENTRAL NEVADA. THIS WILL CONTINUE TO MOVE NORTH TO NORTHWEST DURING THE DAY AND WE`LL START TO SEE CUMULUS DEVELOPING OVER THE CASCADES AND NORTHERN CAL AROUND MIDDAY. HOWEVER THE ATMOSPHERE IS EXPECTED TO BE RATHER DRY AND THE MID LEVEL MOISTURE IS NOT EXPECTED TO INCREASE UNTIL LATER THIS AFTERNOON, THUS HAVE REMOVED ISOLATED THUNDERSTORMS FOR LATE MORNING AND AFTERNOON. HOWEVER THEY ARE STILL A CONCERN STARTING MID AFTERNOON. SOME GUIDANCE SUGGEST THE BEST CHANCE FOR STORMS MAY END UP OVER THE CASCADES AND EASTSIDE, BUT FIND THIS SUSPECT GIVEN WE`LL STILL BE IN A MOIST SOUTH TO SOUTHEAST FLOW AND THE RAP SHOWS PVA MOVING THROUGH SOUTHWEST OREGON IN THE EVENING WITH 850 LI`S IN THE NEGATIVE. ALSO MID LEVEL LAPSE RATES ARE EXPECTED TO INCREASE AND MODEL SOUNDINGS SHOW ENOUGH INSTABILITY TO KEEP ISOLATED STORMS IN THE FORECAST TONIGHT WEST OF THE CASCADES. IT STILL LOOKS LIKE SATURDAY WILL BE THE MOST ACTIVE WITH A GOOD CHUNK OF THE AREA UNDER THE THREAT OF STORMS WITH MORE FREQUENT STORMS POSSIBLE. THE BULK OF THE ACTION WILL GRADUALLY SHIFT EAST SUNDAY AS THE UPPER TROUGH MOVES NORTH SQUEEZING THE RIDGE DOWN A LITTLE. -PETRUCELLI && .AVIATION....AVIATION...FOR THE 26/12Z TAF CYCLE...LOW CLOUDS WILL CONTINUE ALONG THE NORTH COAST WITH IFR TO LIFR CIGS THIS MORNING GRADUALLY RISING TO MVFR THIS AFTERNOON. ELSEWHERE VFR CONDITIONS WILL PREVAIL. LATE THIS AFTERNOON INTO THE EVENING ISOLATED THUNDERSTORMS ARE EXPECTED ALONG AND NEAR THE OREGON CASCADES...THE UPPER KLAMATH BASIN...AND WESTERN SISKIYOU COUNTY. THE BEST CHANCE OF THUNDERSTORMS IS IN THE 00-06Z TIME FRAME FOR THIS TAF CYCLE AT KLMT AND KRBG. THESE STORMS ARE EXPECTED TO BE HIGH-BASED, DRY, AND THEREFORE COULD CONTAIN GUSTY OUTFLOW WINDS AND POSSIBLY ISOLATED MICROBURSTS. BTL/SPILDE && .MARINE....MARINE...UPDATED 900 AM PDT FRIDAY 26 JUNE 2015...A THERMAL TROUGH WILL BRING GALE FORCE NORTH WINDS SOUTH OF CAPE BLANCO TODAY WITH VERY STEEP WIND WAVE DOMINATED SEAS. AS IS TYPICAL WITH THERMAL TROUGH WIND PATTERNS...CONFIDENCE IS ONLY MODERATE ON EXACTLY HOW CLOSE TO SHORE THE GALES REACH...WITH THE FORECAST REFLECTING GALES BEYOND 10 NM FROM SHORE TODAY. THE THERMAL TROUGH WILL WEAKEN AND BOTH WINDS AND SEAS ARE EXPECTED TO LOWER THIS WEEKEND. THUNDERSTORMS ARE POSSIBLE TONIGHT INTO SATURDAY MORNING WITHIN 10 NM FROM SHORE. THE THERMAL TROUGH WILL THEN STRENGTHEN AGAIN MONDAY AND TUESDAY WITH CONDITIONS AT LEAST HAZARDOUS TO SMALL CRAFT. STRONGEST WINDS AND SEAS WILL AGAIN BE SOUTH OF CAPE BLANCO. SK/SPILDE && FIRE WEATHER...UPDATED 400 AM PDT FRIDAY 26 JUNE 2015...HAVE MADE NO CHANGES WITH RESPECT TO THE RED FLAG WARNING (RFWMFR) HEADLINES IN PLACE ACROSS THE AREA BEGINNING LATER THIS AFTERNOON. MODELS CONTINUE TO SHOW MOISTURE INCREASING IN THE SOUTH TO SOUTHEAST FLOW DEVELOPING ALOFT IN A CORRIDOR BETWEEN AN UPPER LOW OFFSHORE AND THE MID LEVEL RIDGE CENTERED OVER THE GREAT BASIN. THIS IS A FAVORABLE THUNDERSTORM PATTERN AND THIS CORRIDOR IS AIMED RIGHT OVER SW OREGON/NORCAL, WHERE ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP LATER THIS AFTERNOON AND EVENING. THIS PATTERN WILL PERSIST FRIDAY NIGHT THROUGH MUCH OF THE WEEKEND AS THE UPPER LOW SLOWLY MOVES NORTHWARD ALONG THE CALIFORNIA COAST. CONFIDENCE ON THE EXACT LOCATION OF STORMS REMAINS FAIRLY LOW AS MID AND UPPER LEVEL SUPPORT FOR STORMS (SHORTWAVES) IS WEAK, BUT WITH STRONG HEATING AND THE RESULTING INSTABILITY OVER ABNORMALLY DRY FUELS ACROSS A LARGE PART OF THE AREA (NEAR-RECORD DRYNESS ALONG THE COAST)...THE THREAT FOR ABUNDANT LIGHTNING IS A BIG CONCERN FOR INITIAL ATTACK. STORMS SHOULD INITIATE OVER THE HIGHER TERRAIN THIS AFTERNOON, THEN PROPAGATE NORTHWESTWARD WITH TIME THIS EVENING AND OVERNIGHT. A STRONG MOISTURE GRADIENT WILL EXIST ALONG THE CASCADES. STORMS OVER THE EAST SIDE SHOULD BE FAIRLY DRY, WHERE PWS ARE GENERALLY LESS THAN 0.75 OF AN INCH. PWS OF 1.00-1.25 INCHES EXIST ALONG AND WEST OF THE CASCADES WHERE STORMS THAT DEVELOP SHOULD BE COMPARABLY WETTER. ANY STORMS WILL HAVE THE ABILITY TO PRODUCE GUSTY OUTFLOWS THAT COULD CAUSE NEW FIRE STARTS TO SPREAD QUICKLY. BY SATURDAY AND SATURDAY NIGHT, ADDITIONAL SHORT WAVE ACTIVITY WILL MOVE NORTH-NORTHWESTWARD INTO THE AREA AND MOISTURE SHOULD BE ADEQUATE FOR MOSTLY WET STORMS. WE STILL EXPECT SATURDAY TO BE THE MOST ACTIVE DAY (AT LEAST IN TERMS OF COVERAGE OF STORMS). BY SUNDAY, THE MODELS SUGGEST THE STRONGEST SHORT WAVE WILL MOVE THROUGH THE AREA. BUT THE AREA OF GREATEST INSTABILITY WILL SLOWLY SHIFT EASTWARD, SO AREAS ALONG AND EAST OF THE CASCADES WILL BE THE AREAS THAT LIKELY SEE THE MOST COVERAGE OF STORMS. FIRE ZONES 615 AND 618 SHOULD BE IN THE CLEAR, WHILE ISOLATED STORMS MAY STILL FORM INLAND OVER THE WEST SIDE. IT WILL BE A CLOSE CALL FOR FIRE ZONE 619. THE RIDGE AXIS SHIFTS EAST MONDAY AS THE UPPER TROUGH AXIS MOVES THROUGH AND THUNDERSTORM THREAT SHOULD BE MOSTLY CONFINED TO PORTIONS OF FIRE ZONES 624 AND 625. SPILDE && .PREV DISCUSSION... /ISSUED 0850 AM PDT FRI JUN 26 2015/ UPDATED MARINE DISCUSSION. DISCUSSION...A HOT AND UNSTABLE AIR MASS WILL PERSIST OVER THE REGION DURING THE NEXT WEEK. LOW PRESSURE OFFSHORE FROM CALIFORNIA AND HIGH PRESSURE CENTERED IN THE GREAT BASIN ARE THE MAIN UPPER LEVEL FEATURES AFFECTING OUR WEATHER IN THE SHORT TERM WITH THAT STRONG RIDGING LIKELY TO PERSIST THROUGH THE WEEK. TODAY AND SATURDAY WILL BE THE HOTTEST DAYS WITH RECORD HIGHS LIKELY TO BE SET. BUT, THE FOLLOWING FIVE DAYS WILL NOT BE THAT MUCH COOLER. THE FORECAST HAS BEEN CONSISTENT IN EXPECTING VALLEY HIGHS DURING THE NEXT TWO DAYS OF 95 TO 110 DEGREES ON THE WEST SIDE OF THE CASCADES THIS AFTERNOON AND 92 TO 102 ON THE EAST SIDE. THE OTHER MAIN FOCUS OF THE FORECAST IS THE DEVELOPMENT OF THUNDERSTORMS WITH THE POTENTIAL FOR LIGHTNING TO CAUSE NEW FIRES. ATMOSPHERIC MOISTURE LEVELS WILL GRADUALLY INCREASE WITH PRECIPITABLE WATER AMOUNTS THAT WERE AT 0.50 TO 0.75 INCHES YESTERDAY TO RISE TO 0.75 TO 1.00 INCHES TODAY. THE LEAST AMOUNT OF RAINFALL WITH THUNDERSTORMS WILL BE IN THOSE THAT DEVELOP SOUTH AND EAST OF SOUTHWEST OREGON. AN EARLY AFTERNOON THUNDERSTORM CANNOT BE COMPLETELY RULED OUT, BUT THERE IS GOOD MODEL AGREEMENT BETWEEN THE NAM AND THE SREF AND RAP SHORT TERM MODELS THAT THE FIRST THUNDERSTORMS WILL DEVELOP AROUND 3 PM OVER THE HIGHER TERRAIN FROM WESTERN SISKIYOU COUNTY TO THE SISKIYOU MOUNTAINS AND CASCADES EASTWARD. COVERAGE OF STORMS WILL INCREASE DURING THE EVENING WITH A PRIMARY FOCUS FOR NORTHWARD MOVING THUNDERSTORMS FROM THE FOOTHILLS OF THE CASCADES (IN EASTERN PORTIONS OF JACKSON AND DOUGLAS COUNTIES) EASTWARD. THAT WILL NOT BE THE EXCLUSIVE LOCATION OF THUNDERSTORMS, JUST THE LIKELY FOCUS. THESE STORMS WILL BE MOVING AT 10 TO 15 KNOTS. EMBEDDED SHORTWAVES IN THE SOUTHERLY FLOW ALOFT ARE EXPECTED TO KEEP THUNDERSTORMS GOING OVERNIGHT INTO SATURDAY MORNING WITH THE HIGHEST PROBABILITY ALONG THE CASCADES. THERE IS UNCERTAINTY IN THE TRACK AND STRENGTH OF SHORTWAVES AS THE GFS HAS A FOCUS DURING THE EVENING HOURS BEFORE LIFTING THE MAJORITY OF ACTIVITY INTO NORTHERN OREGON WHILE THE NAM SOLUTION WOULD ACTUALLY INCREASE THE NUMBER OF THUNDERSTORMS IN OUR AREA DURING THE OVERNIGHT HOURS WHILE SPREADING THEM IN A SOUTHEAST RATHER THAN SOUTH FLOW ALOFT TO THE COAST AND COASTAL WATERS. THUNDERSTORMS ON SATURDAY WILL PRODUCE MORE RAINFALL BUT THEY WILL ALSO BE FASTER MOVING AT 15 TO 25 KNOTS. THUNDERSTORM COVERAGE IS EXPECTED TO BE AT ITS PEAK DURING SATURDAY AFTERNOON AND EVENING. THE PERSISTENT PATTERN WILL ONCE AGAIN PRODUCE NOCTURNAL THUNDERSTORMS SATURDAY NIGHT INTO SUNDAY MORNING. THERE IS UNCERTAINTY IN THE TIMING AND TRACK OF THE OFFSHORE LOW. THE NAM IS FASTER THAN THE GFS BUT BOTH HAVE IT MOVING NORTH TO THE SOUTHERN OREGON COAST ON SUNDAY. THIS WILL BRING IN SLIGHTLY COOLER AIR AND EVENTUALLY KICK THE CONVECTIVE ACTIVITY TO THE EAST WITH WEST SIDE OF THE CASCADES FOCUS OF THUNDERSTORMS ON SUNDAY MORNING SHIFTING TO THE EAST SIDE FOR SUNDAY EVENING INTO MONDAY. THUNDERSTORMS ON SUNDAY WILL HAVE A HIGHER PROBABILITY OF PRODUCING SEVERE WIND GUSTS. THE TROUGH WITH A MUCH DRIER AIR MASS WILL BE IN PLACE OVER THE PACIFIC NORTHWEST ON MONDAY. THUS, A SLIGHT CHANCE OF THUNDERSTORMS WILL BE NEARLY LIMITED TO ONLY LAKE AND MODOC COUNTIES. MONDAY NIGHT SHOULD TRANSPIRE WITHOUT THUNDERSTORMS. RIDGING FROM THE GREAT BASIN IS EXPECTED TO REBUILD INTO OUR AREA TUESDAY FOR THE START OF ANOTHER WARMING TREND INTO THURSDAY. THIS WILL ALSO SEND HIGHER AMOUNTS OF MOISTURE INTO THE EAST SIDE ON TUESDAY THAT WILL EXPAND FARTHER WEST...TO THE WEST SIDE ON WEDNESDAY FOR ANOTHER EPISODE OF A SLIGHT CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS. THE PROBABILITY WILL BE THE LOWEST FOR THE COAST AND DOUGLAS COUNTY. FORECAST UNCERTAINTY INCREASES BEYOND WEDNESDAY AS THE ECMWF MODEL INDICATES A STRONG TROUGH MOVING INTO THE PACIFIC NORTHWEST WILL FINALLY CHANGE THE PATTERN AND BRING SOME COOLING FOR THE END OF THE WEEK, BUT THE GFS IS PERSISTENT AND LEAVES THE HOT GREAT BASIN RIDGE IN COMMAND. FOR NOW, WE WILL LEAN TOWARD PERSISTENCE. && .MFR WATCHES/WARNINGS/ADVISORIES... OR... RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT SUNDAY FOR ORZ615>625. HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 5 AM PDT SUNDAY FOR ORZ023. HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 5 AM PDT SUNDAY FOR ORZ024-026. CA...RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT SUNDAY FOR CAZ280-281-284-285. HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 5 AM PDT SUNDAY FOR CAZ080-081. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT THIS EVENING FOR PZZ350-356-370-376. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT SATURDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT SATURDAY FOR PZZ370-376. GALE WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376. HAZARDOUS SEAS WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376. $$
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
142 PM EDT FRI JUN 26 2015 .SYNOPSIS... HIGH PRESSURE WILL WEAKEN ACROSS THE SOUTHEAST TODAY AS A COLD FRONT APPROACHES. THE COLD FRONT MOVES THROUGH SATURDAY...MOVING EAST OF THE REGION BY SUNDAY. A WEAK FRONT WILL APPROACH BY MID WEEK AND LINGER NEAR THE REGION. && .NEAR TERM /THROUGH TONIGHT/... 130 PM EDT UPDATE...CONVECTIVE ACTIVITY HAS HELD OFF THUS FAR THIS AFTERNOON DUE TO SOME INHIBITION TO VERTICAL MOTION...ESPECIAL IN AREAS IN THE MOUNTAINS TO THE NORTH. MOST MODELS HAVE CONVECTIVE ACTIVITY LATER THIS AFTERNOON...THOUGH WITH DISAGREEMENTS IN LOCATION AND TIMING. CURRENTLY EXPECT CUMULUS FIELD OVER WESTERN GEORGIA TO CONTINUE TO DEVELOP INTO PULSE-TYPE THUNDERSTORMS LATER THIS AFTERNOON. POTENTIALLY MORE SEVERE STORMS COULD DEVELOP OVER THE BLUE RIDGE AS WELL...IF NEGATIVE ENERGY IN THE SOUNDINGS CAN BE OVERCOME...CURRENT SATELLITE SHOWS SOME CU FINALLY BEGINNING TO DEVELOP OVER THE MOUNTAINS AS WELL. 1030 AM EDT UPDATE...AREA IS CLEAR OF RADAR ACTIVITY AT THE MOMENT...WITH AT LEAST SOME ACTIVITY EXPECTED LATER THIS AFTERNOON. LATEST HRRR HAS SOME CONVECTION AFTER 19Z. SHEAR IS BETTER TO THE NORTH IN THE BLUE RIDGE MOUNTAINS...WITH A CONSEQUENT INCREASE IN THE POSSIBILITY FOR SEVERE WEATHER. TWEAKED TEMPERATURES...SKY...AND POP TO ACCOUNT FOR LATEST OBSERVATIONS AND HRRR EXPECTATIONS. AS OF 6 AM...AIDED BY ENCROACHING OUTFLOW BOUNDARIES...A FEW SHOWERS SHOULD PERCOLATE ALONG THE TENN BORDER COUNTIES BEFORE ASHING OUT LATER THIS MORNING. OTHERWISE...VARYING DEGREES OF HIGH LVL DEBRIS CLOUDS WILL GIVE WAY TO DEVELOPING CU. THERE REMAINS THE POSSIBILITY OF DEEP CONVECTIVE REMNANTS FROM KY MCS ACTIVITY REACHING THE NC MTNS BY DAYBREAK BEFORE ASHING OUT COMPLETELY BY MID-MORNING. WILL CONTINUE TO MONITOR CONVECTION ALLOWING MODELS AND UPSTREAM TRENDS. EXPECTING AN UPTICK IN FORCING AND FLOW AS THE AFTERNOON AND EVENING WEARS ON AS S/WV ENERGY ENCROACHES THE SE CONUS AND UPPER HEIGHTS STEADILY FALL. GIVEN THIS...TSTM CVRG MAY WIND UP BECOMING NUMEROUS AND POSSIBLY SVR THIS AFTERNOON GIVEN FORECAST SNDGS DEPICTING MODERATE INSTABILITY...DECENTLY STEEP LAPSE RATES AND FAVORABLE DELTA THETA-E VALUES. WILL FORECAST ONE MORE HOT DAY TODAY...CLOSE TO PERSISTENCE AND FEATURING WIDESPREAD MIDDLE AND UPPER 90S ACRS THE PIEDMONT. IMPULSES WITHIN THE QUICKENING SW FLOW MAY BE ABLE TO SUSTAIN SOME DEGREE OF TSTM ACTIVITY WELL PAST SUNSET...WILL WILL KEEP AT LEAST A TOKEN CHANCE POP INTO THE OVERNIGHT HOURS. && .SHORT TERM /SATURDAY/... AT 230 AM EDT FRIDAY...ON SATURDAY MORNING AN UPPER TROUGH WILL BE OVER THE EASTER USA...WHILE A RIDGE WILL BE OVER THE WEST. THIS PATTERN AMPLIFIES INTO SUNDAY...WHILE A CLOSED UPPER LOW CROSSES THE LOWER GREAT LAKES. A WEAKER OPEN UPPER LOW CROSSES THE UPPER GREAT LAKES ON SUNDAY NIGHT. AT THE SURFACE...A ROBUST COLD WILL APPROACH FORM THE WEST ON ON SATURDAY...CROSSING THE AREA IN THE EARLY EVENING. WHILE CAPE MAY BE SOMEWHAT MODEST...SHEAR WILL BE PRESENT...AND ORGANIZED CONVECTION CANNOT BE RULED OUT. COOLER AND DRIER AIR WILL MOVE IN BEHIND THE FRONT FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. TEMPERATURES WILL RUN BELOW NORMAL. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... AT 230 AM EDT FRIDAY...ON MONDAY AN ANOMALOUS HIGH AMPLITUDE UPPER ROUGH WILL EXTENDING ROM HUDSON BAY TO THE GULF OF MEXICO...WHILE AN UPPER RIDGE WILL BE OVER THE WESTERN USA AND WESTER CANADA. THIS PATTER PERSISTS INTO TUESDAY...THEN DEAMPLIFIES ON WEDNESDAY. ON THURSDAY THE UPPER TROUGH REAMPLIFIES SOMEWHAT...WHILE THE RIDGE TO THE WEST REMAINS RATHER FLAT. AT THE SURFACE...A SURFACE RIDGE WILL BE OVER THE SOUTHERN APPALACHIANS ON MONDAY...IN THE WAKE OF A DEPARTING COLD FRONT. THE TRAILING PORTION OF THE FRONT LIFTS NORTH ACROSS OUR AREA AS A WARM FRONT BY EARLY TUESDAY. ANOTHER COLD FRONT DROPS SOUTHEAST ACROSS OUR AREA ON WEDNESDAY...STALLING NEAR THE NC AND SC BORDER BY THURSDAY. A WEAK CAPPING INVERSION ALOFT MAY KEEP OUR AREA SOMEWHAT STABLE ON MONDAY...BUT WITH FRONTS MOVING TROUGH THE AREA AND INSTABILITY INCREASING...THE REST OF THE WEEK SHOULD BE INCREASINGLY MORE ACTIVE. TEMPERATURES WILL RUN NEAR NORMAL. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AT KCLT AND ELSEWHERE...SHOWERS AND STORMS HAVE HELD OFF THUS FAR THIS AFTERNOON...HOWEVER SOME CUMULUS IS DEVELOPING AS SEEN ON THE VISIBLE SATELLITE...WHICH MAY SIGNAL THE APPROACH OF CONVECTIVE ACTIVITY LATER THIS AFTERNOON. LOCATION AND TIMING OF THUNDER IS SOMEWHAT UNCERTAIN DUE TO POORLY DEFINED SURFACE BOUNDARIES AND FORCING MECHANISMS. CAMS HAVE BEEN INCONSISTENT AS WELL. CURRENTLY EXPECT SOME PULSE STORM ACTIVITY IN AREAS ON THE PIEDMONT HELPED BY A WEAK SHORTWAVE IMPULSE TRAVERSING THE AREA...POTENTIALLY MORE SEVERE ACTIVITY MAY INITIATE IN THE HIGHER TERRAIN IF SOME CONVECTIVE INHIBITION CAN BE OVERCOME. A BREAK IN SHOWERS IS EXPECTED AFTER 6Z BEFORE THE APPROACH OF A COLD FRONT SATURDAY AFTERNOON. OUTLOOK...A COLD FRONT WILL APPROACH FROM THE NW AND PASS THRU ON SATURDAY. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE...PARTICULARLY WHERE HEAVY RAIN FALLS LATER TODAY...AND IN THE MOUNTAIN RIVER VALLEYS. BEHIND THE COLD FRONT...A MUCH DRIER AND COOLER AIRMASS WILL OVERSPREAD THE REGION FOR EARLY NEXT WEEK...WITH A SECOND COLD FRONT POSSIBLY ARRIVING BY MID-WEEK. CONFIDENCE TABLE... 17-23Z 23-05Z 05-11Z 11-12Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 91% KAVL HIGH 100% HIGH 100% HIGH 100% LOW 58% KHKY HIGH 100% HIGH 100% HIGH 100% LOW 58% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 91% 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...JAT NEAR TERM...CSH/WJM SHORT TERM...JAT LONG TERM...JAT AVIATION...WJM
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
130 PM EDT FRI JUN 26 2015 .SYNOPSIS... HIGH PRESSURE WILL WEAKEN ACROSS THE SOUTHEAST TODAY AS A COLD FRONT APPROACHES. THE COLD FRONT MOVES THROUGH SATURDAY...MOVING EAST OF THE REGION BY SUNDAY. A WEAK FRONT WILL APPROACH BY MID WEEK AND LINGER NEAR THE REGION. && .NEAR TERM /THROUGH TONIGHT/... 1030 AM EDT UPDATE...AREA IS CLEAR OF RADAR ACTIVITY AT THE MOMENT...WITH AT LEAST SOME ACTIVITY EXPECTED LATER THIS AFTERNOON. LATEST HRRR HAS SOME CONVECTION AFTER 19Z. SHEAR IS BETTER TO THE NORTH IN THE BLUE RIDGE MOUNTAINS...WITH A CONSEQUENT INCREASE IN THE POSSIBILITY FOR SEVERE WEATHER. TWEAKED TEMPERATURES...SKY...AND POP TO ACCOUNT FOR LATEST OBSERVATIONS AND HRRR EXPECTATIONS. AS OF 6 AM...AIDED BY ENCROACHING OUTFLOW BOUNDARIES...A FEW SHOWERS SHOULD PERCOLATE ALONG THE TENN BORDER COUNTIES BEFORE ASHING OUT LATER THIS MORNING. OTHERWISE...VARYING DEGREES OF HIGH LVL DEBRIS CLOUDS WILL GIVE WAY TO DEVELOPING CU. THERE REMAINS THE POSSIBILITY OF DEEP CONVECTIVE REMNANTS FROM KY MCS ACTIVITY REACHING THE NC MTNS BY DAYBREAK BEFORE ASHING OUT COMPLETELY BY MID-MORNING. WILL CONTINUE TO MONITOR CONVECTION ALLOWING MODELS AND UPSTREAM TRENDS. EXPECTING AN UPTICK IN FORCING AND FLOW AS THE AFTERNOON AND EVENING WEARS ON AS S/WV ENERGY ENCROACHES THE SE CONUS AND UPPER HEIGHTS STEADILY FALL. GIVEN THIS...TSTM CVRG MAY WIND UP BECOMING NUMEROUS AND POSSIBLY SVR THIS AFTERNOON GIVEN FORECAST SNDGS DEPICTING MODERATE INSTABILITY...DECENTLY STEEP LAPSE RATES AND FAVORABLE DELTA THETA-E VALUES. WILL FORECAST ONE MORE HOT DAY TODAY...CLOSE TO PERSISTENCE AND FEATURING WIDESPREAD MIDDLE AND UPPER 90S ACRS THE PIEDMONT. IMPULSES WITHIN THE QUICKENING SW FLOW MAY BE ABLE TO SUSTAIN SOME DEGREE OF TSTM ACTIVITY WELL PAST SUNSET...WILL WILL KEEP AT LEAST A TOKEN CHANCE POP INTO THE OVERNIGHT HOURS. && .SHORT TERM /SATURDAY/... AT 230 AM EDT FRIDAY...ON SATURDAY MORNING AN UPPER TROUGH WILL BE OVER THE EASTER USA...WHILE A RIDGE WILL BE OVER THE WEST. THIS PATTERN AMPLIFIES INTO SUNDAY...WHILE A CLOSED UPPER LOW CROSSES THE LOWER GREAT LAKES. A WEAKER OPEN UPPER LOW CROSSES THE UPPER GREAT LAKES ON SUNDAY NIGHT. AT THE SURFACE...A ROBUST COLD WILL APPROACH FORM THE WEST ON ON SATURDAY...CROSSING THE AREA IN THE EARLY EVENING. WHILE CAPE MAY BE SOMEWHAT MODEST...SHEAR WILL BE PRESENT...AND ORGANIZED CONVECTION CANNOT BE RULED OUT. COOLER AND DRIER AIR WILL MOVE IN BEHIND THE FRONT FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. TEMPERATURES WILL RUN BELOW NORMAL. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... AT 230 AM EDT FRIDAY...ON MONDAY AN ANOMALOUS HIGH AMPLITUDE UPPER ROUGH WILL EXTENDING ROM HUDSON BAY TO THE GULF OF MEXICO...WHILE AN UPPER RIDGE WILL BE OVER THE WESTERN USA AND WESTER CANADA. THIS PATTER PERSISTS INTO TUESDAY...THEN DEAMPLIFIES ON WEDNESDAY. ON THURSDAY THE UPPER TROUGH REAMPLIFIES SOMEWHAT...WHILE THE RIDGE TO THE WEST REMAINS RATHER FLAT. AT THE SURFACE...A SURFACE RIDGE WILL BE OVER THE SOUTHERN APPALACHIANS ON MONDAY...IN THE WAKE OF A DEPARTING COLD FRONT. THE TRAILING PORTION OF THE FRONT LIFTS NORTH ACROSS OUR AREA AS A WARM FRONT BY EARLY TUESDAY. ANOTHER COLD FRONT DROPS SOUTHEAST ACROSS OUR AREA ON WEDNESDAY...STALLING NEAR THE NC AND SC BORDER BY THURSDAY. A WEAK CAPPING INVERSION ALOFT MAY KEEP OUR AREA SOMEWHAT STABLE ON MONDAY...BUT WITH FRONTS MOVING TROUGH THE AREA AND INSTABILITY INCREASING...THE REST OF THE WEEK SHOULD BE INCREASINGLY MORE ACTIVE. TEMPERATURES WILL RUN NEAR NORMAL. && .AVIATION /17Z FRIDAY THROUGH TUESDAY/... AT KCLT AND ELSEWHERE...SHOWERS AND STORMS HAVE HELD OFF THUS FAR THIS AFTERNOON...HOWEVER SOME CUMULUS IS DEVELOPING AS SEEN ON THE VISIBLE SATELLITE...WHICH MAY SIGNAL THE APPROACH OF CONVECTIVE ACTIVITY LATER THIS AFTERNOON. LOCATION AND TIMING OF THUNDER IS SOMEWHAT UNCERTAIN DUE TO POORLY DEFINED SURFACE BOUNDARIES AND FORCING MECHANISMS. CAMS HAVE BEEN INCONSISTENT AS WELL. CURRENTLY EXPECT SOME PULSE STORM ACTIVITY IN AREAS ON THE PIEDMONT HELPED BY A WEAK SHORTWAVE IMPULSE TRAVERSING THE AREA...POTENTIALLY MORE SEVERE ACTIVITY MAY INITIATE IN THE HIGHER TERRAIN IF SOME CONVECTIVE INHIBITION CAN BE OVERCOME. A BREAK IN SHOWERS IS EXPECTED AFTER 6Z BEFORE THE APPROACH OF A COLD FRONT SATURDAY AFTERNOON. OUTLOOK...A COLD FRONT WILL APPROACH FROM THE NW AND PASS THRU ON SATURDAY. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE...PARTICULARLY WHERE HEAVY RAIN FALLS LATER TODAY...AND IN THE MOUNTAIN RIVER VALLEYS. BEHIND THE COLD FRONT...A MUCH DRIER AND COOLER AIRMASS WILL OVERSPREAD THE REGION FOR EARLY NEXT WEEK...WITH A SECOND COLD FRONT POSSIBLY ARRIVING BY MID-WEEK. CONFIDENCE TABLE... 17-23Z 23-05Z 05-11Z 11-12Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 91% KAVL HIGH 100% HIGH 100% HIGH 100% LOW 58% KHKY HIGH 100% HIGH 100% HIGH 100% LOW 58% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 91% 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...JAT NEAR TERM...CSH/WJM SHORT TERM...JAT LONG TERM...JAT AVIATION...WJM
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
235 PM EDT FRI JUN 26 2015 .SHORT TERM /THIS AFTERNOON THROUGH SATURDAY/... THE ATMOSPHERE HAS VERY QUICKLY DESTABILIZED EARLY THIS AFTERNOON...UNDER A SUNNY SKY AND A MOIST ENVIRONMENT. TEMPERATURES HAVE SOARED INTO THE UPPER 80S TO LOWER 90S OVER MUCH OF THE AREA AS OF 2 PM EDT...WITH DEWPOINTS STILL IN THE LOW 70S IN MANY PLACES. THE STAGE IS SET FOR SCATTERED DIURNAL THUNDERSTORM DEVELOPMENT THIS AFTERNOON...WITH STORMS HAVING THE POTENTIAL TO GO STRONG/SEVERE VERY QUICKLY. CAPE VALUES /ALREADY HIGH/...ARE PROGGED TO CLIMB AS HIGH AS 4000+ J/KG BY THE AFTERNOON. THIS WILL ALSO FOR SOME STRONG/ROBUST UPDRAFTS CAPABLE OF PRODUCING LOCALIZED DOWNBURSTS IN THIS FAVORABLE ENVIRONMENT. ADDITIONALLY...LIGHTNING... HEAVY RAINFALL AND MARGINALLY SEVERE HAIL ARE POSSIBLE. THIS INITIAL DIURNAL ACTIVITY SHOULD WANE BY EARLY EVENING. THE THEN MORE CHALLENGING ASPECT OF THE FORECAST WILL BE WHAT EXACTLY WILL OCCUR THIS EVENING/OVERNIGHT. THE LATEST RUNS OF THE HRRR SHOW A MUCH MORE PROGRESSIVE MCS/CONVECTIVE SYSTEM DEVELOPING OVER WESTERN KY/TN AND MOVING INTO THE NW PLATEAU/CUMBERLAND MTNS OF SW VA AROUND 03Z. THE NAM/GFS SOLUTIONS ARE SLOWER...WITH THE CONVECTIVE LINE /IN A WEAKER STATE/...MAKING IT IN AROUND/AFTER 06Z. WHILE INSTABILITY IS MUCH WEAKER /COMPARED TO THIS AFTERNOON/ AFTER SUNSET...WIND SHEAR INCREASES QUITE A BIT AS THE 850 MB LLJ RAMPS UP AND MOVES NORTHEAST OF MIDDLE TN/EASTERN KY. THOUGH SLIGHTLY DISPLACED...THIS FEATURE MAY HELP TO KEEP THE LINE GOING INTO OUR AREA LATE THIS EVENING AND INTO PARTS OF THE OVERNIGHT HOURS. THUS...THINK THAT THERE IS AT SOME RISK FOR ADDITIONAL SEVERE STORMS ALONG THE LINE LATER TONIGHT DESPITE SOME UNCERTAINTY WITH THE EXACT TIMING/DETAILS. THIS ACTIVITY WILL CONTINUE INTO THE MORNING ON SATURDAY...THOUGH IN A MUCH WEAKENED STATE. GOOD CHANCES FOR MUCH NEEDED RAINFALL WILL EXIST WITH THIS SHOWERY ACTIVITY AHEAD OF THE FRONT. ATTENTION WILL QUICKLY TURN TO THE AFTERNOON AS THE ACTUAL COLD FRONT FINALLY MAKES IT INTO THE REGION. SOUNDING PROFILES INDICATE THAT SOME HEATING WILL OCCUR PRIOR TO THE FRONTAL PASSAGE. THIS WILL ALLOW FOR AT LEAST A MARGINALLY UNSTABLE ENVIRONMENT TO DEVELOP OVER THE AREA BY THE MID AFTERNOON. COMBINED WITH BETTER 40-50 KT BULK SHEAR AND SOME COOLER TEMPS ALOFT/LOWER WET-BULB ZERO HGTS...A MARGINAL RISK FOR SEVERE STORMS WILL EXIST IN THE AFTERNOON...MAINLY IN THE 18-00Z TIMEFRAME. SOUNDINGS ALSO SHOW SOME DRIER AIR NEAR THE SURFACE...WHICH WOULD SUGGEST A LOCALIZED DOWNBURST THREAT...ALONG WITH SMALL HAIL. COOLER TEMPS WILL BE IN STORE...WITH HIGHS IN THE UPPER 70S TO LOWER 80S EXPECTED. .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... A COLD FRONT WILL BE EXITING THE AREA SATURDAY EVENING AND A FEW SHOWERS MAY LINGER ACROSS THE REGION UNTIL AROUND MIDNIGHT. HOWEVER...BEHIND THE FRONT...DRY AND MUCH COOLER AIR WILL PUSH IN. SUNDAY SHOULD BE DRY AND WILL ONLY SEE HIGHS REACH INTO THE LOWER TO MID 80S ACROSS MUCH OF THE VALLEY. THE COOLER AIR MASS WILL PERSIST THROUGHOUT THE EXTENDED BUT THE DRY CONDITIONS WILL BE SHORT LIVED AS WE QUICKLY TRANSITION INTO AN UNSETTLE WEATHER PATTERN. THROUGHOUT THE WEEK...A SERIES OF WEATHER SYSTEMS WILL MOVE THROUGH. TIMING OF EACH SYSTEM OR DISTURBANCE IS IN QUESTION BUT SHOULD SEE A CHANCE OF CONVECTION PRETTY MUCH EACH PERIOD. THE PERIODS WITH THE BEST CHANCE OF SCATTERED THUNDERSTORM DEVELOP WILL BE MONDAY NIGHT INTO TUESDAY AND AGAIN AROUND THE THURSDAY TIME FRAME. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 73 83 63 85 / 70 80 20 0 KNOXVILLE MCGHEE TYSON AIRPORT, TN 71 81 60 82 / 80 80 20 0 OAK RIDGE, TN 71 80 60 82 / 80 80 20 0 TRI CITIES AIRPORT, TN 68 78 58 79 / 80 80 30 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ AMP/MJB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
215 PM CDT FRI JUN 26 2015 .SHORT TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 215 PM CDT FRI JUN 26 2015 CONVECTION FIRING IN A BROAD REGION OF UNSTABLE AIR...JUST NEEDING A FOCUS TO GET IT GOING. LATEST RADAR IMAGERY PLACES ONE CLUSTER DIVING SOUTH ACROSS CENTRAL MN IS TIED TO A BIT OF UPPER LEVEL ENERGY. OVER IA INTO NORTHERN ILL IS CO-LOCATED WITH THE BASE OF THE UPPER LEVEL TROUGH. ELSEWHERE...ENHANCED CU AND SOME ISOLATED SHOWERS WERE THE RULE. HEADING INTO THE EVENING...EXPECT BOTH AREAS OF PCPN TO CONTINUE - DYING OUT WITH THE LOSS OF THE DAYTIME HEATING. BUT...THE RAP AND NAM12 SUGGEST A SOUTHWEST-NORTHEAST RUNNING BOUNDARY ACROSS THE FORECAST AREA...WHICH COULD SERVE AS A TRIGGER FOR A SCATTERED LINE OF SHOWERS/STORMS LATE AFTERNOON/EARLY EVENING. WILL MONITOR AND INCREASE POPS IF THIS BECOMES LIKELY. UPPER LEVEL SHORTWAVE TROUGH SLATED TO MOVE ACROSS THE AMPLIFIED RIDGE OVER THE WEST...SPINNING ACROSS THE UPPER MISSISSIPPI RIVER VALLEY ON SUNDAY. DECENT QG CONVERGENCE WITH THIS FEATURE...ALONG WITH LOW LEVEL WARMING - ALTHOUGH MOSTLY CENTERED OVER IA. 300 MB JET STREAK LOOKS TO ENHANCE THE LIFT. PLENTY OF DYNAMICS AND ENOUGH SATURATION FOR AN AREA OF SHOWERS AND THUNDERSTORMS...AND ALL THE MODELS HAVE SAID AS MUCH OVER THE PAST FEW DAYS. QUESTIONS ARISE WITH THE TIMING OF THE SHORTWAVE/AREAS OF RAIN AND HOW MUCH INSTABILITY/SHEAR WILL BE PRESENT. 12Z GFS/NAM RUNS BRING THE SHORTWAVE IN BY 12Z SUN...WITH PCPN LIKELY FOR AT LEAST THE WESTERN 1/2 OF THE FORECAST AREA BY THAT TIME. THE PCPN AND TROUGH AXIS THEN SWINGS INTO WESTERN WI FOR SUN AFTERNOON. NOT A LOT OF SHEAR THROUGH THE DAY...MOST OF WHICH LIES IN THE 0-3KM LAYER - ROUGHLY 20-30 KTS. AS ONE WOULD EXPECT...NOT MUCH INSTABILITY AT 12Z SUN MORNING...BUT THE GFS/NAM DEVELOP A RIBBON OF 1500-2000 J/KG SBCAPE ACROSS THE WESTERN 2/3RDS OF THE FORECAST AREA IN THE AFTERNOON. HOWEVER...THIS IS POST THE PCPN SHIELD AND MUCH OF THE DYNAMICS. NOT SURE IT WILL/COULD BE UTILIZED BY THE EXPECTED ONGOING CONVECTION...OR FOR ANY REDEVELOPMENT IN THE WEST. AS A RESULT...BELIEVE THE POTENTIAL FOR ORGANIZED SEVERE WEATHER IS LOW...ALTHOUGH A FEW STRONGER STORMS COULD BE POSSIBLE. ALL IN ALL...SUNDAY LOOKS LIKE A WET DAY...WEST OF THE MISSISSIPPI RIVER IN THE MORNING...EAST IN THE AFTERNOON. .LONG TERM...(MONDAY THROUGH FRIDAY) ISSUED AT 215 PM CDT FRI JUN 26 2015 AFTER SUNDAY...THE GFS/ECMWF HOLD ONTO THE WESTERN RIDGE-EASTERN TROUGH CONFIGURATION FOR MUCH OF THE NEW WEEK...KEEPING THE LOCAL AREA UNDER NORTHWEST FLOW. VARIOUS PERTURBATIONS IN THE UPPER LEVEL LEVEL FLOW WOULD SPIN ACROSS THE UPPER MISSISSIPPI RIVER VALLEY...RESULTING IN PERIODIC RAIN CHANCES. MODEL DIFFERENCES IN PLACEMENT AND TIMING OF THESE BITS OF ENERGY - AS EXPECTED - BUT NONE OF THE SOLUTIONS ARE SUGGESTIVE OF WIDESPREAD...ALL-DAY KIND OF RAIN EVENTS. INSTABILITY AND WIND SHEAR DON/T FAVOR ORGANIZED SEVERE WEATHER AT THIS TIME EITHER. WILL CONTINUE THE BLANKET OF SMALL RAIN CHANCES THROUGH THE PERIOD...REVISING AS THE DETAILS BECOMING CLEARER. WITH THE RELATIVELY COOLER NORTHWEST TRAJECTORY COUPLED WITH CLOUDS/RAIN POTENTIAL...TEMPERATURES SHOULD HOLD NEAR OR BELOW THE SEASONABLE NORMALS. IN ADDITION...NO TO LIMITED TAP INTO GULF MOISTURE DURING THE WEEK SHOULD KEEP HUMIDITIES IN CHECK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1254 PM CDT FRI JUN 26 2015 ISOLATED SHOWERS ARE DEVELOPING ALONG A WEAK AREA OF CONVERGENCE ACROSS SOUTHEAST MINNESOTA. DUE TO THIS...INCLUDED SHOWERS IN THE TEMPO GROUP AT KRST THROUGH 26.20Z. OTHERWISE...THERE WILL BE A SCATTERED TO BROKEN 3-5K DECK OF CLOUDS THROUGH 27.05Z AND THEN SKIES WILL CLEAR. WINDS WILL BE INITIALLY BE NORTHEAST AND THEN SHIFT TO NORTH AFTER 27.05Z. WIND SPEEDS WILL BE LESS THAN 10 KNOTS. WITH LIGHT WINDS TONIGHT AND SCATTERED SHOWERS THROUGH THIS EVENING...WILL HAVE TO WATCH FOR THE POTENTIAL OF FOG...BUT WITH UNCERTAINTY ON WHERE THESE SHOWERS WILL OCCUR...DID NOT INCLUDE IT IN THE TAFS AT THIS TIME. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RIECK LONG TERM....RIECK AVIATION.....BOYNE