Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/14/14


AREA FORECAST DISCUSSION
NWS PUEBLO CO
341 PM MDT MON MAY 12 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 340 PM MDT MON MAY 12 2014 ...HEAVY SNOW CONTINUES FOR THE CONTINENTAL DIVIDE...WITH FREEZING TEMPERATURES FOR THE SOUTHEAST PLAINS TONIGHT... ENERGY DROPPING DOWN THE WEST SIDE OF THE UPPER TROF WILL KEEP SNOW SHOWERS GOING ACROSS SOUTHERN AND WESTERN PORTIONS OF THE AREA. LAPSE RATES ARE STEEP BENEATH THE UPPER TROF ALOFT..AND SNOW HAS BEEN REALLY COMING DOWN IN WEB CAMS AT WOLF CREEK. VIS IS DOWN TO 1/4 MILE AS OF THIS LAST HOUR. ROADWAYS STILL LOOK CLEAR...BUT WITH TEMPERATURES ALREADY IN THE 20S ACROSS THE HIGHER ELEVATIONS...IT WOULD NOT TAKE MUCH MORE COOLING FOR SNOW TO BEGIN TO STICK. NAM12...GFS...AND RAP ALL KEEP HEAVY SNOW CONTINUING THROUGH THE OVERNIGHT HOURS...THOUGH MAJORITY WILL LIKELY FALL BEFORE MIDNIGHT. FOR THAT REASON...UPGRADED THE WINTER WEATHER ADVISORIES FOR THE HIGHER ELEVATIONS OF THE EASTERN SAN JUANS AND LA GARITAS TO A WINTER STORM WARNING WITH AN EARLIER FORECAST PACKAGE UPDATE. EASTERLY UPSLOPE FLOW INTO THE EASTERN SLOPES OF THESE RANGES WILL ALSO LEAD TO FAIRLY HEALTHY SNOW AMOUNTS FOR THE WESTERN SIDE OF THE SAN LUIS VALLEY. CDOT WEBCAM AT ANTONITO HAS SOME SNOW FALLING...THOUGH MOST IS MELTING ON PAVEMENT SURFACES...AND WITH TEMPERATURES STILL AROUND OR SLIGHTLY ABOVE FREEZING EXPECT THIS TO CONTINUE. HAVE PUT UP A WINTER WEATHER ADVISORY FOR THE LOWER ELEVATIONS OF THE EASTERN SAN JUANS AND LA GARITAS AS WELL AS THE HIGHER AREAS OF THE SAWATCH RANGE. WARNING AREAS COULD PICK UP A TOTAL OF 8 TO 16 INCHES...WITH 4 TO 8 INCHES FOR THE ADVISORY AREAS. THE WESTERN SIDE OF THE SAN LUIS VALLEY COULD SEE ON THE ORDER OF 1 TO 4 INCHES...BUT WARM GROUND MAY LIMIT ACCUMULATIONS TO LESSER AMOUNTS. THE SANGRES AND WETS COULD ALSO PICK UP SOME ADDITIONAL ACCUMULATIONS TONIGHT...WITH ANOTHER 1 TO 3 INCHES FOR THE LOWER ELEVATIONS...AND 2 TO 5 INCHES FOR THE HIGHER PEAKS. SNOW WILL WIND DOWN EARLY TOMORROW MORNING...SO HEADLINES WILL EXPIRE AT 6 AM. MEANWHILE...SOUTHEAST PLAINS WILL SEE A WIDESPREAD FREEZE TONIGHT...AND CURRENT FREEZE WARNING STILL LOOKS ON TRACK. UPPER TROF AXIS WILL SHIFT EAST OF THE AREA ON TUESDAY...BUT WITH LINGER MOISTURE AND INSTABILITY...EXPECT ANOTHER ROUND OF ISOLATED TO SCATTERED SHOWERS ACROSS THE MOUNTAINS. TEMPERATURES WILL REBOUND A FEW DEGREES OVER THOSE OF TODAY...BUT HIGHER MOUNTAINS WILL STILL SEE PRECIPITATION IN THE FORM OF SNOW. ANY ACCUMULATIONS SHOULD REMAIN LIGHT...WITH A SPOTTY 1-3 INCHES POSSIBLE. -KT .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 340 PM MDT MON MAY 12 2014 TUESDAY NIGHT THROUGH SATURDAY...LONG RANGE MODELS INDICATE THAT THE UPPER SYSTEM WILL PARK OVER THE MIDWEST THROUGH MUCH OF THE WORK WEEK...KEEPING COLORADO UNDER NW FLOW ALOFT. THIS FLOW IS A COOLER ONE...SO THE WARM UP FOR THE FORECAST AREA IS EXPECTED TO BE SLOWER UNTIL THE UPPER PATTERN SHIFTS. THE UPPER RIDGE TO THE WEST IS FORECAST TO FINALLY FLATTEN AND SLIDE ACROSS THE STATE ON SAT. THIS TRANSLATES TO ANOTHER THREAT OF FREEZING TEMPS FOR THE PLAINS TUE NIGHT...THEN HIGH TEMPS ON WED IN THE 50S AND 60S. TEMPS GRADUALLY WARM THU THROUGH SAT WITH MAX TEMPS IN THE 70S FOR THE PLAINS...AND IN THE 60S FOR THE HIGH VALLEYS. EXTENDED MODELS ALSO HINT AT MORE OF A SUMMERTIME PATTERN WHEN IT COMES TO CONVECTION...WITH AN ISOLATED THREAT FOR SHOWERS AND STORMS OVER THE MTS EACH AFTN AND EARLY EVE THROUGH SAT. SUNDAY AND MONDAY...A LARGE UPPER TROUGH OF LOW PRESSURE MOVES ONSHORE ACROSS THE WEST COAST LATE SAT...PRODUCING INCREASING SW FLOW ALOFT FOR THE DESERT SW. LOOK FOR DRY AND VERY WARM CONDITIONS FOR THE FORECAST AREA BOTH SUN AND MON...WITH MAX TEMPS IN THE 80S FOR THE E PLAINS...AND IN THE 60S AND 70S FOR THE HIGH VALLEYS. MOORE && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 340 PM MDT MON MAY 12 2014 VFR CIGS EXPECTED AT KCOS AND KPUB...THOUGH KCOS COULD SEE A BRIEF DIP TO MVFR AS SHOWERS DROP DOWN OUT OF THE NORTH AND CLIP BY THE TERMINAL. NORTH WINDS OFF THE PALMER DIVIDE SHOULD PREVENT FOG FORMATION TOWARDS MORNING...THOUGH SOME MVFR STRATUS WILL BE POSSIBLE AT TIMES TUESDAY MORNING. KALS WILL SEE THE BEST CHANCE FOR SNOW SHOWERS...THOUGH ACCUMULATIONS AT THE TERMINAL SHOULD REMAIN AROUND AN INCH OR LESS...MAINLY ON GRASSY SURFACES. VFR CONDITIONS ARE EXPECTED ALL THREE TERMINALS TUESDAY AFTERNOON. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM MIDNIGHT TONIGHT TO 8 AM MDT TUESDAY FOR COZ083>089-093>099. WINTER WEATHER ADVISORY UNTIL 6 AM MDT TUESDAY FOR COZ060-064- 067. WINTER STORM WARNING UNTIL 6 AM MDT TUESDAY FOR COZ066-068. && $$ SHORT TERM...KT LONG TERM...MOORE AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1217 PM MDT MON MAY 12 2014 .UPDATE... ISSUED AT 1208 PM MDT MON MAY 12 2014 ANOTHER DISTURBANCE COMING DOWN THE BACK SIDE OF THE UPPER TROF WILL KEEP SNOW GOING ALONG THE CONTINENTAL DIVIDE. NAM...GFS...AND RAP ALL SUGGEST WARNING CRITERIA SNOWFALL WILL OCCUR ACROSS THE HIGHER ELEVATIONS OF THE EASTERN SAN JUAN AND LA GARITAS WITH ADVISORY SNOWFALL AMOUNTS FOR THE LOWER ELEVATIONS. THIS SEEMS REASONABLE GIVEN THE FORCING AND INSTABILITY PRESENT. HAVE UPGRADED THE WINTER WEATHER ADVISORIES TO WARNINGS FOR ZONES 66 AND 68...AND HOISTED ADVISORIES FOR THE LOWER ELEVATIONS OF THE EASTERN SAN JUANS AND LA GARITAS...AS WELL AS THE HIGHER ELEVATIONS OF THE SAWATCH RANGE. AS TEMPERATURES DROP INTO THIS EVENING...EXPECT ROADWAYS WILL BECOME SLICK AND SNOW PACKED. WESTERN PORTIONS OF THE SAN LUIS VALLEY COULD PICK UP 1 TO 4 INCHES OF SNOW WITH EASTERLY UPSLOPE FLOW IMPINGING ON THE HIGHER TERRAIN...THOUGH SUSPECT THAT WARM GROUND WILL MELT SOME OF THIS OFF AS IT FALLS THIS AFTERNOON...SO NO HIGHLIGHTS APPEAR NEEDED. ANOTHER WAVE OF MODERATE TO HEAVY SNOW IS CURRENTLY FALLING ACROSS THE EASTERN SLOPES OF THE WETS AND SANGRES THIS AFTERNOON. HIGH RES HRRR WANES THIS OFF PRETTY QUICKLY THROUGH THE EARLY AFTERNOON...SO WILL NOT HOIST ANY HIGHLIGHTS JUST YET...BUT WILL MONITOR THESE AREAS CLOSELY. -KT UPDATE ISSUED AT 905 AM MDT MON MAY 12 2014 ANOTHER BAND OF SNOW IS MOVING INTO NORTHERN EL PASO AND TELLER COUNTIES THIS MORNING. ALTHOUGH ADDITIONAL SNOWFALL AMOUNTS WILL REMAIN LIGHT (1-2 INCHES)...GUSTY WINDS AND POOR VISIBILITIES WILL KEEP TRAVEL CONDITIONS POOR. HAVE OPTED TO ALLOW THE WINTER STORM WARNINGS FOR TELLER AND NORTHERN EL PASO COUNTY TO EXPIRE...BUT HAVE PUT UP A WINTER WEATHER ADVISORY UNTIL NOON TO ACCOUNT FOR CONTINUING SNOWFALL AND POOR VISIBILITY. ALL OTHER HIGHLIGHTS ASIDE FROM THE SOUTHWEST MOUNTAIN WINTER WEATHER ADVISORY...HAVE EXPIRED AT 9 PM. -KT UPDATE ISSUED AT 816 AM MDT MON MAY 12 2014 UPDATED TO TAKE DOWN FREEZE WARNINGS VALID FOR THIS MORNING. HOWEVER...ANOTHER ROUND OF FREEZING TEMPERATURES IS EXPECTED TONIGHT...AND FREEZE WARNINGS ARE ALREADY OUT. -KT && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 340 AM MDT MON MAY 12 2014 ...MAIN CONCERNS INCLUDE UNSEASONABLY COLD TEMPS FOR TODAY...FREEZING TEMPS FOR PLAINS TONIGHT...AND SNOWS FOR THE SW MTNS... CURRENTLY... WEATHER SYSTEM THAT HAS BROUGHT BENEFICIAL PRECIP TO THE REGION (ALONG WITH LATE SEASON SNOW) IS GRADUALLY WINDING DOWN OVER A GOOD PART OF THE REGION. MOST PRECIP OVER THE PLAINS IS DECREASING AT 3 AM WITH A SOME PRECIP STILL NOTED GENERALLY N OF HIGHWAY 50. PRECIP WAS STILL OCCURRING OVER THE MTNS AS PER RADAR...SFC OBS AND WEB CAMS. SAT PIX AND MOSAIC RADAR IMGY STILL SHOWS LOW SPINNING OVER THE CO REGION WITH 1 WELL DEFINED VORT CENTER OVER NC CO WHILE THE MAIN LOW WAS STILL BACK OVER THE 4 CORNERS REGION. TODAY... PRECIP OVER THE PLAINS WILL CONTINUE TO DECREASE AND EXPECT MOST IF NOT ALL OF IT TO BE OVER WITH BY MID TO LATE MORNING. ONLY EXCEPTION WILL BE OVER THE PALMER DVD WHERE SHOWERS MAY LINGER INTO EARLY AFTERNOON GIVEN THE STRONG NORTHERLY FLOW. MAIN AREA OF PRECIP WILL BE OVER THE GREATER SAN JUAN REGION. TROUGH IS GOING TO HOLD BACK OVER THIS AREA TODAY AND TONIGHT...AND FLOW AT 700 MB BECOMES EASTERLY OVER THE S CENTRAL CO REGION. THIS FLOW COMBINED WITH FAVORABLE LAPSE RATES AND QG FORCING SHOULD ALLOW FOR SEVERAL MORE INCHES OF SNOW FOR THE HIGHER ELEVATIONS OF THE SAN JUANS...ALONG WITH LOWER ELEVATION RAIN/SNOW SHOWERS. FOR THIS REASON I EXTENDED THE WINTER WX ADVISORIES FOR THE SAN JUAN REGION. IT IS QUITE POSSIBLE THAT WARNING CRITERIA MAY OCCUR GIVEN THE CONVECTIVE NATURE OF THE SNOW THAT WILL OCCUR TODAY. IT IS GOING TO BE QUITE COOL TODAY OVER THE REGION AND MAX TEMPS WILL RANGE 25 TO 30F DEGREES BELOW NORMAL. HIGHS WILL ONLY BE MAINLY IN THE 40S OVER THE PLAINS WITH A 50 OR TWO OVER THE FAR E PLAINS. TEMPS OVER THE PALMER DIVIDE WILL BE IN THE 30S. WE MAY SEE A MINIMUM MAX TEMP RECORD TODAY FOR AREAS OF THE PLAINS. GIVEN THE GUSTY NNW WINDS IT WILL EVEN FEEL COLDER. IN A NUTSHELL...IT WILL FEEL MORE LIKE MARCH THAN MID MAY. DRESS APPROPRIATELY. TONIGHT... FREEZE WARNINGS HAVE BEEN ISSUED FOR THE ENTIRE PLAINS. TEMPS ALONG THE LOWER ARK RVR VALLEY WILL GENERALLY BE AT OR AROUND 32 WITH TEMPS ON THE PALMER DVD AND RATON MESA IN THE 25 TO 30F DEGREE RANGE. SNOW WILL CONTINUE OVER THE SAN JUANS THIS EVENING BUT SHOULD DECREASE IN INTENSITY AND COVERAGE DURING THE EARLY MORNING HOURS AS THE LOW SHIFT EAST-SOUTHEAST INTO THE TX PHDL REGION. OVERALL...WE COULD SEE 4-8 OF ADDITIONAL SNOW FOR THE SAN JUANS TODAY THROUGH TONIGHT. /HODANISH .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 340 AM MDT MON MAY 12 2014 MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED WITH A HIGHLY AMPLIFIED PATTERN ACROSS THE REGION. AN UPPER LEVEL STORM SYSTEM STRETCHING FROM THE NORTHERN PLAINS TO THE DESERT SOUTHWEST WILL BEGIN TO SLOWLY MOVE EASTWARD ON TUESDAY. A DISTURBANCE ALONG THE BACKSIDE OF THE MAIN TROUGH WILL BE TRACKING SOUTH ACROSS THE CONTINENTAL DIVIDE TUESDAY MORNING AND MOVE INTO NEW MEXICO BY TUESDAY AFTERNOON. MODELS ALL HAVE WIDESPREAD LIGHT TO MODERATE SNOWFALL FOR ALL MOUNTAIN AREAS TUESDAY MORNING. THE HEAVIEST SNOW WILL LIKELY FALL OVER THE SAN JUAN RANGE WHERE AN ADDITIONAL 2 TO 4 INCHES OF SNOW ARE EXPECTED. THE CENTRAL AND EASTERN MOUNTAINS WILL LIKELY SEE AN ADDITIONAL 1 TO 3 INCHES ON TUESDAY. ON THE PLAINS...EXPECT DRY AND BREEZY CONDITIONS WITH COOL AFTERNOON HIGHS IN THE 50S. MODELS ALL HAVE PRECIPITATION FOR THE MOUNTAINS COMING TO AN END BY TUESDAY EVENING AS THE UPPER SYSTEM SHIFTS EAST...AND THE DISTURBANCE EMBEDDED IN THE BACKSIDE FLOW IS SOUTH IN NEW MEXICO. OVERNIGHT LOWS TUESDAY NIGHT INTO WEDNESDAY MORNING WILL ONCE AGAIN DROP INTO THE UPPER 20S TO LOWER 30S. THOSE WITH SENSITIVE OUTDOOR PLANTS SHOULD BRING THEM INDOORS. THE PATTERN STALLS ON WEDNESDAY...WITH THE LARGE UPPER LEVEL TROUGH FROM THE GREAT LAKES INTO THE SOUTHERN PLAINS...WHILE AN UPPER LEVEL RIDGE BUILDS ALONG THE WEST COAST. THIS WILL PUT SOUTHERN COLORADO UNDER BROAD AND PERSISTENT NORTHWESTERLY FLOW. PRECIPITATION CHANCES WILL BE HIGHLY DEPENDENT ON EMBEDDED DISTURBANCES IN THE NORTHWEST FLOW THROUGH AT LEAST FRIDAY. PERIODS OF LIGHT SNOW WILL BE POSSIBLE ACROSS THE MOUNTAIN AREAS EACH DAY. AS FOR THE PLAINS...MODELS REMAIN CONSISTENT WITH A DISTURBANCE ON THURSDAY NIGHT INTO FRIDAY WHICH MAY BRING SHOWER ACTIVITY TO AT LEAST THE FAR EASTERN PLAINS. COVERAGE AND CONVECTIVE NATURE ARE HIGHLY UNCERTAIN FOR THE PLAINS AT THIS TIME BUT THE POSSIBILITY IS THERE. TEMPERATURES WILL GRADUALLY WARM WEDNESDAY THROUGH FRIDAY...WITH THE PLAINS REACHING THE 70S BY THURSDAY AND FRIDAY. THE PATTERN WILL BEGIN TO PROGRESS ON SATURDAY AS A STORM SYSTEM OFF THE BRITISH COLUMBIA COAST MOVES ONSHORE. THIS WILL FORCE THE UPPER RIDGE OVER COLORADO. EXPECT DRY CONDITIONS THROUGH THIS PERIOD WITH MUCH WARMER TEMPERATURES. HIGHS ACROSS THE EASTERN PLAINS WILL LIKELY REACH WELL INTO THE 80S WITH A FEW LOW 90S POSSIBLE. MOZLEY && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1141 AM MDT MON MAY 12 2014 CIGS WILL REMAIN MVFR TO VFR THROUGH THE AFTERNOON AT THE TAF SITES...THOUGH THERE IS THE POTENTIAL INTO THIS EVENING FOR KALS TO DROP DOWN INTO THE IFR CATEGORY IN SNOW SHOWERS AND FOG. KCOS WILL ALSO HAVE THE POTENTIAL FOR SOME STRATUS AND FOG TOWARDS MORNING...THOUGH HAVE KEPT CIGS IN THE MVFR RANGE FOR NOW. WINDS WILL REMAIN GUSTY OUT OF THE NORTH AT 20 TO 35 KTS FOR BOTH KCOS AND KPUB THROUGH THE AFTERNOON BEFORE DECREASING OVERNIGHT. WINDS AT KALS WILL REMAIN OUT OF THE EAST AT 10-15 KTS THROUGH THE AFTERNOON. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM MIDNIGHT TONIGHT TO 8 AM MDT TUESDAY FOR COZ083>089-093>099. WINTER WEATHER ADVISORY UNTIL 6 AM MDT TUESDAY FOR COZ060-064- 067. WINTER STORM WARNING UNTIL 6 AM MDT TUESDAY FOR COZ066-068. && $$ UPDATE...KT SHORT TERM...HODANISH LONG TERM...MOZLEY AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1118 PM MDT SUN MAY 11 2014 .UPDATE... ISSUED AT 1108 PM MDT SUN MAY 11 2014 UPDATED TO CANCEL WINTER WX ADVISORY FOR SOUTHERN EL PASO COUNTY AND TO ADD OTERO COUNTY TO THE FREEZE WARNING. ALSO ADJUSTED SNOW AMOUNTS FOR TONIGHT. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 258 PM MDT SUN MAY 11 2014 ...SIGNIFICANT SNOWS EXPECTED TO CONTINUE ACROSS THE CENTRAL MOUNTAINS AND PIKES PEAK REGION... UPPER LOW NEARING THE FOUR CORNERS REGION THIS AFTERNOON WILL BE LIFTING NORTHEASTWARD OVERNIGHT INTO NORTHEAST CO BY 18Z MONDAY. SURFACE FRONT HAS PUSHED THROUGH ALL OF THE SOUTHEAST PLAINS AS OF 21Z. SNOWFALL AMOUNTS SO FAR HAVE BEEN HIGHLY DETERMINED BY THE SNOW LEVELS AND WARM GROUND. PIKES PEAK REGION HAS ALREADY DROPPED INTO THE LOWER TO MID 30S...WITH UPPER 20S ACROSS TELLER COUNTY. THIS HAS BEEN THE AREA WHICH HAS RECEIVED THE MOST SNOW...THOUGH A LOOK AT WEB CAMS ACROSS THE AREA SHOWS THAT WARM GROUND HAS MITIGATED ACCUMULATIONS SOME. MAINLY GRASSY SURFACES HAVE ACCUMULATION...BUT OCCASIONALLY HAVE SEEN SOME SNOW ON THE PAVEMENT DURING THE HEAVIER SNOW BURSTS. STILL WAITING FOR SNOW LEVELS TO DROP ACROSS THE UPPER ARKANSAS RIVER VALLEY...WITH SALIDA AND BUENA VISTA AIRPORTS STILL IN THE 40S AS OF 21Z. DOWN AROUND COLORADO CITY AND RYE...TEMPERATURES ARE STILL IN THE UPPER 30S AND LOWER 40S...BUT TEMPERATURES HAVE BEEN DROPPING QUICKLY THIS LAST HOUR AND SUSPECT RAIN/SNOW SWITCH OVER FOR THE UPPER ARKANSAS RIVER VALLEY OF FREMONT AND CHAFFEE AND THE LOWER ELEVATION OF THE WET MOUNTAINS IS NOT LONG OFF. AS FOR HIGHLIGHTS...HAVE LEFT THEM AS IS. A LITTLE CONCERNED THAT LATER SWITCH OVER TO SNOW ACROSS LOWER ELEVATIONS OF CHAFFEE COUNTY MAY HURT SNOW TOTALS SOME...BUT BEST FORCING WILL CONTINUE TO TREK ACROSS THIS AREA THROUGH THE EVENING...AND LATEST 18Z NAM IS NOW HITTING THIS AREA WITH AROUND 4 INCHES OF SNOW THROUGH THE EVENING HOURS. ONCE THE SWITCH OVER OCCURS...IT WILL NOT TAKE LONG FOR ACCUMULATIONS TO START STACKING UP...THOUGH SUSPECT THE WARM GROUND WILL MAKE FOR A WIDE RANGE OF ACCUMULATIONS WITH LOCATIONS LIKE SALIDA COMING UP ON THE LOW END. ON THE FENCE WITH UPGRADING TO A WINTER STORM WARNING FOR THE LOWER ELEVATIONS OF THE WET MOUNTAINS AND THE NORTHERN SANGRE DE CRISTO MOUNTAINS. THERE COULD BE A FEW AREAS THAT HIT AROUND 12 INCHES...BUT THE LATE TRANSITION OVER TO SNOW WILL LARGELY KEEP AMOUNTS MORE IN THE ADVISORY RANGE. AS FOR TIMING OF THE HEAVIER SNOWS...HEAVIEST SHOULD FALL NOW THROUGH MIDNIGHT. AFTER MIDNIGHT...BEST FORCING SHIFTS NORTH OF THE AREA...AND ALTHOUGH THERE WILL STILL BE SOME WRAP AROUND SNOWS ACROSS THE CENTRAL MOUNTAINS/PIKES PEAK AREA...DOWNSLOPE NORTHERLY WINDS OFF THE PALMER DIVIDE SHOULD OPEN UP THE PRECIPITATION MINIMUM ACROSS SOUTHERN EL PASO AND NORTHERN PUEBLO COUNTIES. THIS COULD OCCUR AS EARLY AS 10 PM. WINTER WEATHER ADVISORIES FOR SOUTHERN EL PASO COUNTY MAY RUN A TAD TOO LONG...BUT WILL LET LATER SHIFTS MONITOR TRENDS AND MAKE ANY NEEDED ADJUSTMENTS. THE WET MOUNTAINS AND SOUTHERN I-25 CORRIDOR WILL SEE MORE CONVECTIVE BURSTS OF RAIN/SNOW...WHICH SHOULD SWITCH OVER TO ALL SNOW BY AROUND 6 PM. HOWEVER...MAJORITY OF THE HEAVIER SNOW MAY BE DONE BY 6 AM...AND POSSIBLY EVEN SOONER IF LATEST HRRR IS CORRECT. AS FOR THE SOUTHEAST PLAINS...HAVE EXTENDED THE FREEZE WARNING TO INCLUDE CROWLEY COUNTY...AS AM GETTING A FEW HOURS OF SUBFREEZING TEMPERATURES THERE. NOT MUCH SNOW IS EXPECTED...THOUGH SWITCH OVER COULD OCCUR AROUND 6 PM FOR PUB...AROUND MIDNIGHT FOR LHX...AND EVEN LATER FOR POINTS FARTHER EAST WHERE IT MAY STAY ALL RAIN...OR GO TO A BRIEF RAIN/SNOW MIX TOWARDS MORNING BEFORE IT ENDS. GRASSY SURFACES AROUND PUEBLO...WALSENBURG...TRINIDAD COULD SEE AN INCH OR TWO AT ANY TIME...BUT WARM GROUND MAY MELT IT OFF QUICKLY. ON MONDAY...ANOTHER TRAILING DISTURBANCE DROPS IN IN NORTHWEST FLOW ALOFT...AND SENDS ANOTHER ROUND OF SNOW INTO THE MOUNTAIN AREAS...PARTICULARLY ALONG THE CONTINENTAL DIVIDE. THIS CONTINUES INTO MONDAY EVENING. ITS POSSIBLE THESE AREAS MAY NEED ANOTHER HIGHLIGHT...MOST LIKELY AN ADVISORY...BUT SINCE THERE SEEMS TO BE A DISTINCT BREAK BETWEEN THE TWO SYSTEMS...WILL LET LATER SHIFTS DETERMINE WHAT IF ANY HIGHLIGHTS WILL BE NEEDED. SUSPECT THAT TO SOME EXTENT...THE HIGHER SNOWFALL AMOUNTS IN THE GFS MAY BE A TAD OVERDONE DUE TO SOME CONVECTIVE COMPONENT...AND HAVE GONE CLOSER TO THE NAM FOR NOW. -KT .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 258 PM MDT SUN MAY 11 2014 SECONDARY UPPER LOW AND UPSLOPE FLOW WILL KEEP SOME SNOW GOING OVER THE SAN JUANS/SANGRES MON EVENING...AND SOME ADDITIONAL LIGHT ACCUMULATION IS POSSIBLE WITH BEST CHANCE OVER THE EASTERN SAN JUANS. PRECIP THEN SLOWLY SHIFTS SOUTH OVERNIGHT AS UPPER TROUGH MOVES EAST...WHICH WILL END MOST ACCUMULATING SNOW BY EARLY TUESDAY MORNING. MANY AREAS WILL HAVE THE POTENTIAL FOR FREEZING TEMPS ONCE AGAIN BY EARLY TUE MORNING...THOUGH AMOUNT OF MID LEVEL CLOUDINESS MAY BE THE DETERMINING FACTOR ON HOW WIDESPREAD COLD TEMPS BECOME. VERY GRADUAL WARMING AND DRYING TREND BEGINS TUESDAY AFTERNOON...THOUGH SOME RESIDUAL MOISTURE/INSTABILITY OVER THE MOUNTAINS MAY PRODUCE A FEW LIGHT SHOWERS TUE AFTERNOON. NEUTRAL TO WEAK WARM ADVECTION...COMBINED WITH INCREASING MAY SUN SHOULD BOOST MAX TEMPS SEVERAL DEGF VERSUS MONDAYS HIGHS...THOUGH READINGS WILL STILL RUN WELL BELOW SEASONAL AVERAGES. ANOTHER THREAT OF SOME PATCHY FROST TUE NIGHT/WED MORNING AS SKIES CLEAR...ESPECIALLY EL PASO COUNTY/LOW LYING AREAS OF PUEBLO COUNTY. UPPER RIDGE THEN BUILDS OVER THE WESTERN U.S. FOR MID-WEEK...THEN GRADUALLY FLATTENS NEXT WEEKEND. IN GENERAL...GRADUAL WARMING/DRYING TREND IN STORE FOR THE AREA THROUGH THE PERIOD...THOUGH A COUPLE WAVES EMBEDDED IN THE NW FLOW MAY PRODUCE AT LEAST SOME ISOLATED -TSRA/-SHRA OVER THE EASTERN MOUNTAINS AND PLAINS THU/FRI AS MODEST LOW LEVEL MOISTURE RETURNS SLOWLY INTO THE HIGH PLAINS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1108 PM MDT SUN MAY 11 2014 KALS...VFR CONDITIONS EXPECTED FOR ALS FOR THE NEXT 24 HRS...WITH SHOWERS IN THE VCNTY THROUGH 18Z TODAY. AFTER 18Z...A BRIEF BREAK THEN SHOWERS WILL REDEVELOP OVER THE MTS TO THE WEST. KCOS AND KPUB...IFR CONDITIONS WITH -SHRASN IN THE VCNTY THROUGH 18Z AND STRONG NORTH WINDS WITH GUSTS UP TO 35 MPH EXPECTED. VFR CONDITIONS THEN DEVELOPING AFTER 18Z AS THE UPPER SYSTEM LIFTS OUT TO THE EAST. MOORE && .PUB WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING UNTIL 8 AM MDT MONDAY FOR COZ083>089-093-094. WINTER STORM WARNING UNTIL 9 AM MDT MONDAY FOR COZ058>063-073- 076-080>082-084. WINTER WEATHER ADVISORY UNTIL 9 AM MDT MONDAY FOR COZ072-074-075- 077>079. WINTER WEATHER ADVISORY UNTIL 6 AM MDT MONDAY FOR COZ066-068. && $$ UPDATE...28 SHORT TERM...KT LONG TERM...PETERSEN AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1000 PM EDT TUE MAY 13 2014 .SYNOPSIS... WILL SEE THE RETURN OF SEASONABLE CONDITIONS UNDER SOUTHERLY FLOW INTO WEDNESDAY. WARMER AND MORE HUMID CONDITIONS THURSDAY AND FRIDAY WILL BE ACCOMPANIED BY SCATTERED SHOWERS...THEN A PERIOD OF HEAVY RAINFALL IS EXPECTED FRIDAY NIGHT INTO SATURDAY AS A SLOW MOVING COLD FRONT MOVES INTO THE REGION. UNSETTLED WEATHER WILL CONTINUE INTO EARLY NEXT WEEK WITH TEMPS TRENDING COOLER THAN NORMAL. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 10 PM UPDATE... PRIMARY FORECAST PARAMETERS ARE ON TRACK WITH THIS UPDATE. MAIN CHANGES WERE TO BRING TEMPS/DWPTS BETTER IN LINE. LATEST RAP BASED LAV GUIDANCE AND GFS MOS WERE HANDLING EACH OF THESE WELL...SO ADJUSTMENTS ARE TOWARD THEIR SOLUTIONS FOR THE REMAINDER OF THE OVERNIGHT HOURS. OTHERWISE...MAINLY DRY FOR MUCH OF THE NIGHT AS WARM FRONT REMAINS HUNG UP WELL TO THE SW. THE ONLY ISSUE OF NOTE IS THE CONVECTION CURRENTLY FIRING AND BUILDING ACROSS CENTRAL NY S OF LAKE ONTARIO. DUE NOTE A THETA-E GRADIENT FROM CENTRAL NY INTO THE WRN REACHES OF SRN NEW ENGLAND FOR THIS TO RIDE ALONG. HOWEVER...INSTABILITY IS LACKING. HRRR/NAM/SREF SOLUTIONS DO SHOW THESE ARRIVING AN HOUR OR TWO AFTER SUNRISE...SO MAY NEED TO KEEP AN EYE ON THIS...ALTHOUGH WITH THE MORE STABLE AIRMASS IN PLACE OVER SRN NEW ENGLAND AND TYPICAL DIUNRAL STABILIZATION OF THE AIRMASS...THESE WOULD LIKELY ARRIVE ONLY AS SOME SCT -SHRA IN THE E SLOPES OF THE BERKSHIRES AND WRN REACHES OF HARTFORD COUNTY CT BEFORE THEY DRY UP WITHIN THE INVERTED RIDGE. FOR NOW...HAVE UPPER END OF NIL POPS...BUT THESE MAY NEED TO BE ADJUSTED AS THE NIGHT PROGRESSES AND A TREND IS ESTABLISHED. PREVIOUS DISCUSSION... HIGH PRESSURE IN CONTROL AS THE MID- TO UPPER-LEVEL RIDGE CRESTS INTO NEW ENGLAND. A DRY FORECAST. MOSTLY CLOUDY CONDITIONS THROUGHOUT THE OVERNIGHT AS WEAK E-FLOW VEERS SOUTHERLY. COMBINED WITH A CHILLIER AIRMASS IN PLACE...EXPECT LOWS TO FALL INTO THE LOW- TO MID-40S. COULD SEE A FEW ISOLATED SPOTS FALL BELOW 40-DEGREES. HIGHER DEWPOINT AIR REMAINING S OF THE REGION SO DO NOT ANTICIPATE ANY FOG IMPACTS. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... WEDNESDAY... RIDGE OF HIGH PRESSURE PUSHES E ALLOWING CLOUDS TO INCREASE ACROSS THE REGION AS WINDS VEER AND BECOME BREEZY OUT OF THE S. WILL SEE THE STALLED FRONT S AND W OF THE REGION LIFT BACK N AS A WARM FRONT BUT PERHAPS KINK ALONG THE COASTLINE AS HIGH-RES FORECAST MODELS SIGNAL A DAMMING SIGNAL ACROSS THE COLDER WATERS THROUGH WHICH THE ISALLOBARIC COMPONENT OF FLOW NETS A MORE EASTERLY WIND. WHILE CLOUDS MAY IMPEDE SUNSHINE...FEEL HIGHS WILL REACH SEASONABLE LEVELS AROUND THE UPPER-60S TO LOW-70S FOR THE INTERIOR WHILE COOLER ALONG THE SHORE WITH THE AFOREMENTIONED DAMMING SIGNAL AND EASTERLY WIND OFF THE WATERS. LOW CLOUDS AND FOG WILL BE POSSIBLE ALONG THE S-SHORE LATE IN THE DAY AS HIGHER DEWPOINT AIR SURGES N OVER THE COOLER WATERS. NOTING THE WINDS...HAVE GREATER CONFIDENCE OF LOW-STRATUS OVER OCEAN-FOG. DRIZZLE WILL BE POSSIBLE WITH THE WEAK COMPONENT OF UPSLOPE FLOW PER OROGRAPHIC TERRAIN AND SHALLOW COLD-DOME OF AIR IMMEDIATELY ABOVE THE WATERS. OTHERWISE THE REMAINDER OF THE FORECAST REGION LOOKS TO REMAIN DRY AS THE BETTER MOISTURE AND FORCING REMAIN TO THE W OF THE REGION. CAN NOT RULE OUT THE SLIGHT CHANCE POSSIBILITY OF A STRAY SHOWER INTO THE FAR W NEW ENGLAND...BUT WILL HOLD WITH MODEL CONSENSUS SIGNALING THE PROXIMITY OF HIGH PRESSURE ALONG WITH ATTENDANT DRY AIR AND SUBSIDENCE LIMITING ACTIVITY. THUS LOW CONFIDENCE THUNDER. WEDNESDAY NIGHT... RIDGE OF HIGH PRES IS MAINTAINED IN CLOSE PROXIMITY TO S NEW ENGLAND BY WARM AIR ADVECTION AHEAD OF THE CENTRAL CONUS TROUGH. THIS KEEPS THE BETTER FORCING TO THE W WHILE ALLOWING AN INCREASING S-FETCH OF MOISTURE WITH PWATS UP TO 1.5-INCHES. CONSIDERING THE S-FLOW TO WHICH AIDS IN SURGING HIGHER DEWPOINT AIR N ACROSS THE COOLER WATERS UNDERGOING WEAK LIFT...LOW STRATUS AND FOG LIKELY ALONG THE S-COAST BUILDING N ACROSS THE INTERIOR. DRIZZLE WILL ALSO BE POSSIBLE. NOTING THE STRENGTH OF S-WINDS...HAVE GREATER CONFIDENCE OF LOW-CLOUDS OVER FOG. EXPECTING MIN TEMPERATURES TO BE OBSERVED AROUND MIDNIGHT WITH A NON- DIURNAL TREND THEREAFTER AS THE KINKED SURFACE WARM FRONT ALONG THE SHORE GRADUALLY LIFTS NE BUCKED BY THE INCREASING S-WINDS. LOWS DOWN TO THE UPPER-50S WITH A FEW LOCALES ACROSS THE INTERIOR POSSIBLY REMAINING AT OR ABOVE 60-DEGREES. COOLEST CONDITIONS ALONG THE S- SHORE. && .LONG TERM /THURSDAY THROUGH TUESDAY/... HIGHLIGHTS... * MILD AND HUMID WITH SCATTERED SHOWERS THURSDAY AND FRIDAY * MORE WIDESPREAD SHOWERS WITH POTENTIAL FOR HEAVY RAINFALL FRI NIGHT INTO SAT * REMAINING UNSETTLED INTO EARLY NEXT WEEK WITH TEMPS TRENDING BELOW NORMAL OVERVIEW... OVERALL UNSETTLED CONDITIONS EXPECTED FOR MUCH OF THE EXTENDED PERIOD. HIGH AMPLITUDE PATTERN SETS UP ACROSS THE CONUS WITH WESTERN ATLANTIC RIDGE TRANSITIONING TO A REX BLOCK OVER THE NORTH ATLANTIC THIS WEEKEND. MID LEVEL TROUGH MOVING EAST FROM THE UPPER MIDWEST AND GT LAKES WILL SLOW TO A CRAWL AND TAKE ON NEGATIVE TILT AS DOWNSTREAM BLOCKING PATTERN SETS UP. RESULT WILL BE DEEP MERIDIONAL FLOW WHICH WILL TRANSPORT HIGH PWAT PLUME NORTHWARD INTO SNE WITH POTENTIAL FOR HEAVY RAINFALL...ESPECIALLY FRI NIGHT INTO SAT. A PIECE OF THE MID LEVEL TROUGH EVENTUALLY CLOSES OFF AND MOVES OVER NEW ENG EARLY NEXT WEEK BRINGING A CONTINUATION OF UNSETTLED WEATHER WITH TEMPS TRENDING BELOW NORMAL. THE DAILIES... THURSDAY INTO THURSDAY NIGHT... SFC HIGH SHIFTS EAST OF NEW ENGLAND WITH BROAD SOUTHERLY FLOW DEVELOPING WHICH MAY BECOME A BIT GUSTY. USING A MOS/MODEL BLEND TEMPS THU WILL REACH THE 70S THU ACROSS MUCH OF SNE...EXCEPT 60S ALONG THE SOUTH COAST. THE SOUTHERLY FLOW WILL ADVECT HIGHER DEWPOINTS INTO THE LOWER 60S SO THERE WILL BE SOMEWHAT OF A SUMMER FEEL TO THE AIRMASS. PLENTY OF LOW LEVEL MOISTURE WILL LEAD TO AREAS OF STRATOCU AND STRATUS...ESPECIALLY INTERIOR ALONG WITH PATCHY FOG AND SOME DRIZZLE POSSIBLE. LOW LEVEL THETA-E RIDGE SETS UP WITH SOME ELEVATED INSTABILITY SO THERE WILL ALSO BE A RISK OF A FEW SHOWERS. FRIDAY INTO SATURDAY... SLOW MOVING COLD FRONT WILL BE APPROACHING FROM THE WEST NOT MOVING THROUGH THE REGION UNTIL LATE SAT/SAT NIGHT. DEEP SOUTHERLY FLOW AHEAD OF THE FRONT TRANSPORTS PWAT PLUME AROUND 1.5" INTO SNE WHICH IS ABOUT +2 SD AND SOUTHERLY LOW LEVEL JET UPWARDS TO +3 SD. THIS COMBINED WITH THE SLOW MOVING NATURE OF THIS SYSTEM LEADS TO ABOVE AVERAGE CONFIDENCE OF HEAVY RAINFALL. TIMING OF THE HEAVIEST RAINFALL IS MOSTLY FRI NIGHT INTO SAT MORNING WHEN RIGHT ENTRANCE REGION OF THE UPPER JET BECOMES COLOCATED WITH THE LOW LEVEL JET FOR OPTIMUM FORCING FOR ASCENT. THE HEAVIER SHOWERS MAY REACH W ZONES DURING FRI AFTERNOON BUT NOT UNTIL LATE FRI NIGHT FOR EASTERN NEW ENG. THERE IS SOME ELEVATED INSTABILITY SO A FEW TSTMS ALSO POSSIBLE. PROJECTED RAINFALL AMOUNTS ARE 1-3 INCHES WITH AXIS OF HEAVIEST RAIN ACROSS WESTERN NEW ENG. SATURDAY NIGHT INTO SUNDAY... BULK OF RAINFALL APPEARS TO SHIFT TO THE EAST SATURDAY AFTERNOON... BUT THERE ARE HINTS THAT A WAVE WILL DEVELOP ALONG THE BOUNDARY TO THE SOUTH AS SHORTWAVE ENERGY ROUNDS THE BASE OF THE TROF WITH INVERTED TROF EXTENDING N INTO NEW ENG WHICH WOULD LEAD TO CONTINUED RAIN THREAT SAT NIGHT INTO SUNDAY ESPECIALLY IN E NEW ENG. ECMWF MOST AGGRESSIVE WITH THIS SCENARIO AND WE HAVE THE HIGHEST POPS IN THE EAST DURING THIS PERIOD. MONDAY INTO TUESDAY... CLOSED LOW MOVES INTO NEW ENG AND LINGERS INTO TUE WITH COLD POOL OF -25C AT 500 MB. STEEP MID LEVEL LAPSE RATES AND TT INCREASING INTO THE 50S SUGGEST SCT TO NUMEROUS SHOWERS BOTH DAYS ALONG WITH A CHANCE OF TSTMS. TEMPS COOLER THAN NORMAL IN THE LOWER TO MID 60S. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH WEDNESDAY NIGHT/...MODERATE CONFIDENCE. MAINLY VFR CIGS...BUT AREAS OF MVFR/IFR CIGS WILL AFFECT THE OUTER CAPE AND ACK THROUGH MIDNIGHT. LOCALIZED MVFR CIGS ALSO POSSIBLE NC MA INTO S NH. WEAKENING E/NE WINDS ACROSS MUCH OF THE REGION WITH A SE FLOW THROUGH THE LOWER CT- VALLEY BECOMING LIGHT AND VARIABLE OVERNIGHT BEFORE VEERING SE INTO WEDNESDAY. CONDITIONS DETERIORATING INTO LATE WEDNESDAY. IFR CLOUDS AND POSSIBLE FOG DEVELOPING ALONG THE S-COAST ALONG WITH -DZ. IFR CONDITIONS AND -DZ SPREAD N AND INTO THE INTERIOR WEDNESDAY NIGHT. LIFR-VLIFR POSSIBLE ESP WITH DENSE FOG. HIGHER CONFIDENCE OF AT LEAST IFR CIGS WITH STRENGTH OF S-WINDS LATE WEDNESDAY INTO WEDNESDAY NIGHT. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE. THU INTO THU NIGHT....AREAS OF MVFR/IFR IN STRATUS AND PATCHY FOG. SCATTERED SHOWERS AND PATCHY DRIZZLE POSSIBLE. FRIDAY INTO SATURDAY...CONTINUED MVFR/IFR WITH WIDESPREAD SHOWERS AND ISOLATED TSTMS DEVELOPING BY LATE FRI IN THE WEST SPREADING EAST ACROSS THE REST OF SNE FRI NIGHT INTO SAT. AREAS OF LLWS POSSIBLE FRI NIGHT INTO SAT. SUNDAY...MVFR/VFR CIGS WITH SCT SHOWERS...ESPECIALLY EASTERN HALF NEW ENG. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE. E-WINDS RELAXING WITH INCREASING INFLUENCE OF HIGH PRESSURE. WINDS GRADUALLY VEER SOUTHERLY INTO WEDNESDAY CONTINUING INTO WEDNESDAY NIGHT WITH GUSTS REMAINING BELOW 20 KTS. SUBSEQUENTLY SEAS SHOULD REMAIN BELOW 5 FEET. ANY EXISTING SMALL-CRAFT ADVISORIES WILL BE ALLOWED TO EXPIRE BY SUNDOWN. MAIN CONCERN IS FOR LATE WEDNESDAY INTO WEDNESDAY NIGHT AS S-WINDS FETCH WARMER AIR N ACROSS THE COLDER WATERS NETTING A COMBINATION OF LOW-CLOUDS AND FOG. VISIBILITIES DOWN TO A MILE OR LESS ARE POSSIBLE. DRIZZLE WILL BE POSSIBLE AS WELL. HAVE GREATER CONFIDENCE OF LOW-CLOUDS OVER FOG WITH THE BRISK S-WINDS. SHOULD FOG DEVELOP...HAVE THE GREATEST CONFIDENCE TOWARDS IMPACTS ALONG THE S-COAST OF RI/MA PERHAPS EXCLUDING CAPE COD AND THE ISLANDS. OUTLOOK...THURSDAY THROUGH SUNDAY...HIGH CONFIDENCE. THU INTO FRI...SOUTHERLY WINDS INCREASING UP TO 20 KTS WITH A FEW G25 KT POSSIBLE...ESPECIALLY DURING FRI. PATCHY FOG WILL REDUCE VSBYS AT TIMES. BUILDING SEAS OVER THE OPEN WATERS FROM COMBINED SWELL AND WIND WAVE FRI NIGHT INTO SAT...LOW LEVEL JET MOVES ACROSS THE WATERS WILL LEAD TO SOUTHERLY WIND GUSTS TO 25-30 KT. LOW PROB OF MARGINAL GALES. WINDS DIMINISHING LATE SAT/SAT NIGHT. VSBYS REDUCED IN SHOWERS AND FOG. SUNDAY...WINDS BELOW SCA...BUT SCA SEAS OVER THE OUTER WATERS. SCT SHOWERS...ESPECIALLY E WATERS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...KJC/SIPPRELL NEAR TERM...DOODY/SIPPRELL SHORT TERM...SIPPRELL LONG TERM...KJC AVIATION...KJC/SIPPRELL MARINE...KJC/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAUNTON MA
305 PM EDT MON MAY 12 2014 .SYNOPSIS... HIGH PRESSURE REMAINS IN CONTROL THROUGH TODAY THEN A BACK DOOR COLD FRONT STARTS MOVING THROUGH THE REGION LATE TONIGHT INTO TUESDAY. MARITIME HIGH PRESSURE WEDNESDAY PROVIDES BELOW AVERAGE TEMPERATURES FOLLOWED BY A PERIOD OF UNSETTLED WEATHER THURSDAY INTO THE WEEKEND. THE BEST CHANCE OF HEAVY RAIN AND POSSIBLE THUNDERSTORMS IS EXPECTED FRIDAY NIGHT INTO SATURDAY. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... 2 PM UPDATE... TEMPS NOW IN THE LOW TO MID 80S AT 2 PM ACROSS THE INTERIOR IN RESPONSE TO DEEP BLYR MIXING WITH SURFACE WINDS WSW UP TO 20-25 MPH. AT THE COAST PGRAD WEAK ENOUGH TO SUPPORT A SSW WIND. HOWEVER TEMPS AT THE SHORE STILL WARM WITH READINGS 75-80! WATCHING AREA OF CLOUD DEVELOPMENT OVER PA WITH NOTICEABLE CYCLONIC SWIRL AS LOW AMPLITUDE SHORT WAVE MOVES ACROSS THIS AREA. THIS SHOWS UP NICELY ON THE SPC MESOANALYSIS ESPECIALLY AT H7. SHOWERS TRYING TO DEVELOP BUT INSTABILITY IS LACKING...BOTH AT THE SURFACE AND ALOFT. DEW PTS ACROSS SOUTHERN NEW ENGLAND REMAIN DRY WITH VALUES IN THE U30S AND L40S. SOME INSTABILITY OVER SOUTHERN NJ THAT MAY ADVECT NORTHEAST INTO NYC/LONG ISLAND. THUS ANY SHOWER ACTIVITY SHOULD SLIDE ACROSS PA/NJ/NYC...PERHAPS CLIPPING SOUTHWEST CT. THEREFORE EXPECTING SOUTHERN NEW ENGLAND TO REMAIN DRY THRU THIS EVENING. PREVIOUS DISCUSSION BELOW. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ANOTHER SPECTACULAR DAY IN PROGRESS WITH DEEP LAYER RIDGE OVER THE EASTERN GREAT LAKES AND SURFACE HIGH SOUTH OF NEW ENGLAND. THIS SETUP IS PROVIDING LARGE SCALE SUBSIDENCE OVER THE REGION ALONG WITH LOW LEVEL WESTERLY FLOW. THUS ABUNDANT SUNSHINE PREVAILS ALONG WITH COMFORTABLE HUMIDITY WITH DEW PTS IN THE 30S AND 40S. UPSTREAM SOUNDING AT ALBANY NY SUPPORTS HIGHS AROUND 80F WITH 850 TEMPS OF +11C. HOWEVER WITH BLYR EXTENDING UP TO 700 MB ALONG WITH WESTERLY BLYR WINDS HIGHS WILL CLIMB INTO THE M80S WITH A LOW PROBABILITY OF A FEW SPOTS BRIEFLY GETTING INTO THE U80S! THUS HAVE INCREASED HIGHS A TAD FROM PREVIOUS FORECAST. THINK DRY WEATHER WILL PREVAIL TODAY DESPITE BACKDOOR FRONT APPROACHING FROM MAINE. PREFRONTAL AIRMASS IS VERY DRY WITH DEW PTS IN THE 30S AND 40S. THIS RESULTS IN VERY LITTLE TO ANY AVAILABLE INSTABILITY. IN ADDITION AS BLYR DEEPENS WINDS BECOME WEST AND LIMIT SURFACE CONVERGENCE. HENCE DRY WEATHER SHOULD PREVAIL THRU SUNSET. THIS IS TYPICALLY THE CASE AHEAD OF BACKDOOR FRONTS. IN ADDITION LATEST HRRR KEEPS SOUTHERN NEW ENGLAND DRY THRU 23Z FOLLOWED BY A FEW POSSIBLE SHOWERS/TSTMS ZIPPING ACROSS WESTERN CT THEREAFTER. HOWEVER THIS IS A VERY LOW PROB. OTHERWISE PREVIOUS FORECAST IN GOOD SHAPE AND NO MAJOR CHANGES PLANNED. && .SHORT TERM /7 PM THIS EVENING THROUGH TUESDAY NIGHT/... TONIGHT...AN APPROACHING WARM FRONT WILL BE STALLED BY A LOW PRESSURE MOVING EAST INTO MAINE. ONCE THIS LOW PRESSURE MOVES QUICKLY EAST...A STRONG HIGH PRESSURE WILL START TO BUILD SOUTH ACROSS NORTHERN NEW ENGLAND. THIS HIGH PRESSURE WILL PUSH A BACK DOOR COLD FRONT INTO SOUTHERN NEW ENGLAND LATE TONIGHT INTO TUESDAY. WILL CONTINUE THE CHANCE FOR SOME SHOWERS INTO PARTS OF OUR REGION TONIGHT...AT LEAST UNTIL THE SUBSIDENCE BECOMES DOMINANT. THERE IS STILL SOME QUESTION AS TO WHEN THIS OCCURS... BUT THE LATEST THINKING IS IT MAY TAKE MOST OF THE NIGHT. COOLER OVERNIGHT TEMPERATURES ARE EXPECTED AS WINDS SHIFT TO THE NORTH AND NORTHEAST BEHIND THE BACK DOOR COLD FRONT. TUESDAY... BACK-DOOR COLD FRONT CONTINUES TO MOVE WEST AS A HIGH PRESSURE BUILDS OVER THE GULF OF MAINE. IT WILL TURN UNSEASONABLY COOL WITH ONSHORE FLOW OFF ROUGHLY UPPER 40S DEGREE WATER. LIKELY TO BE FAIRLY CLOUDY WITH A LONG FETCH OF EASTERLY FLOW UNDERGOING WEAK UPSLOPE AS OVERRUNNING REMAINS PREVALENT ALONG THE LOW- TO MID- LEVEL FRONTAL BOUNDARY SITUATED ACROSS AND TO THE WEST OF NEW ENGLAND. AS SUCH CANNOT COMPLETELY RULE OUT A STRAY SHOWER OR TWO. HOWEVER...EXPECTING MAINLY DRY CONDITIONS. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... HIGHLIGHTS... * DRY WEDNESDAY * UNSETTLED THU INTO WEEKEND WITH POTENTIAL FOR HEAVY RAIN * REMAINING COOL EARLY NEXT WEEK WITH SPOTTY SHOWERS FAIRLY CONFIDENT ON EVOLVING LARGE SCALE PATTERN LATER THIS WEEK AND THROUGH WEEKEND. BUILDING RIDGE OVER WEST COAST LEADS TO DEEPENING FULL LATITUDE TROUGH OVER EASTERN STATES...WHICH EVENTUALLY CLOSES ITSELF OFF OVER GREAT LAKES AS RIDGING PERSISTS ACROSS NORTH ATLANTIC. RESULT IS PERSISTENT S/SE FLOW WHICH WILL LEAD TO PERIODS OF AT LEAST ISOLATED OR SCATTERED SHOWERS. RAINFALL SHOULD BECOME MORE WIDESPREAD AS SLOW MOVING FRONT APPROACHES LATE FRI/SAT...WHEN LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE. WED... UPPER RIDGE BUILDS OVER NEW ENGLAND WHILE HIGH PRESSURE REMAINS OFFSHORE. THIS SHOULD MAINTAIN DRY WEATHER WITH NEAR SEASONABLE TEMPERATURES...ASIDE FROM IMMEDIATE COAST DUE TO ONSHORE FLOW. THU INTO SAT... MAY SEE FEW SHOWERS THU DUE MORE TO PROLONGED S FLOW AS OPPOSED TO SLOW MOVING COLD FRONT WHICH SHOULD STILL BE WELL TO OUR W. COULD BE RATHER WARM/MUGGY DAY THU AS WEAK RIDGING STILL PREVAILS... WHICH MAY ALLOW CLOUDS TO BREAK FOR A TIME. ENSEMBLES AND 12Z MODELS SUGGEST MAIN WINDOW FOR MORE WIDESPREAD SHOWERS/ISOLATED THUNDERSTORMS WILL BE LATE FRI INTO SAT MORNING AS FRONT PUSHES THROUGH. DEEP S FLOW WITH UPPER LOW CLOSING OFF ACROSS GREAT LAKES WILL BRING ANOMALOUSLY MOIST /+2 TO +3 SD/ AIRMASS INTO REGION ALONG WITH FAIRLY POTENT 850 MB JET. EARLY INDICATIONS ARE FOR AS MUCH AS 1 TO 2 INCHES OF RAIN DURING THIS TIME FRAME PER ENSEMBLE PROBABILITIES. SUN AND MON... DESPITE FRONT MOVING OFFSHORE...CLOSED UPPER LOW MEANS COOL/SHOWERY PERIOD MAY BE IN STORE. 12Z GFS IS MOST AGGRESSIVE WITH THIS FEATURE AS IT IS DAMPENED OUT IN ENSEMBLE MEANS. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY/...HIGH CONFIDENCE. THRU 00Z...VFR WITH SSW WINDS ALONG THE COAST AND WSW INLAND GUSTING UP TO 20 KT. DRY WEATHER PREVAILS WITH ANY SHOWERS/TSTMS DEVELOPING OVER PA MOVING INTO NJ/NYC/LONG ISLAND AND OFFSHORE. LOW PROBABILITY OF THIS ACTIVITY CLIPPING WESTERN CT. AFTER 00Z...BACKDOOR FRONT FROM MAINE MOVES SOUTHWEST-WARD INTO MA/RI/CT BEGINNING 01Z/02Z FIRST ACROSS NORTHEAST MA AND THEN SOUTHWEST-WARD AS THE EVENING PROGRESSES. FRONT WILL COME THRU DRY WITH ANY SHOWER ACTIVITY ACROSS THE LOWER HUDSON VALLEY OF NY/NYC/LONG ISLAND...POSSIBLY CLIPPING CT. TUE AND TUE NIGHT...VFR WITH MAINLY DRY WEATHER. ANY PRECIP WOULD BE VERY LIGHT IN THE FORM OF SPRINKLES. NE WINDS TUE WITH GUSTS UP TO 20 KT ALONG THE COAST...BECOME SE TUE NIGHT. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. S WINDS BECOME SW AS THE AFTERNOON PROGRESSES. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WEDNESDAY...HIGH CONFIDENCE. VFR WITH POSSIBLE MVFR CIGS NEAR COAST. THURSDAY...MODERATE CONFIDENCE. MVFR IN SCT SHOWERS. IFR POSSIBLE NEAR COAST IN FOG/DRIZZLE. FRIDAY INTO SATURDAY...MODERATE CONFIDENCE. MVFR/IFR IN MORE WIDESPREAD SHOWERS AND ISOLATED TSTMS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. HIGH CONFIDENCE THROUGH TUESDAY. WINDS AND SEAS EXPECTED TO REMAIN BELOW SMALL CRAFT CRITERIA THROUGH TODAY. WINDS INCREASE AS A BACK DOOR COLD FRONT MOVES FROM NORTHEAST TO SOUTHWEST TONIGHT. SMALL CRAFT ADVISORIES MAY AGAIN BE NECESSARY FOR A TIME TONIGHT INTO TUESDAY...THOUGH SEAS LOOK TO REMAIN BELOW 5 FEET. AT THIS POINT...DO NOT HAVE ENOUGH CONFIDENCE IN REACHING 25 KT GUSTS OR 5 FOOT SEAS TO ISSUE SMALL CRAFT ADVISORIES NOW. IT DOES REMAIN A POSSIBILITY...AND IS SOMETHING FUTURE SHIFTS WILL HAVE TO CONSIDER. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WEDNESDAY...HIGH CONFIDENCE. HIGH PRESSURE REMAINS OFFSHORE WITH S/SE FLOW ACROSS WATERS. INCREASING E SWELL BUT SHOULD STAY BELOW SCA. MAY SEE AREAS OF FOG/DRIZZLE LATER IN DAY OR AT NIGHT. THURSDAY INTO SATURDAY...MODERATE CONFIDENCE. PERSISTENT S/SE WINDS SHOULD REMAIN BELOW 25 KT BUT SEAS WILL SLOWLY BUILD THROUGH PERIOD...PROBABLY REACHING 5 TO 8 FT ON OUTER WATERS. AREAS FOG SHOULD PREVAIL ALONG WITH AT LEAST SCATTERED SHOWERS. BETTER CHANCE OF WIDESPREAD SHOWERS/FEW THUNDERSTORMS LATE FRI INTO SAT AS SLOW MOVING COLD FRONT APPROACHES WATERS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...NOCERA/JWD NEAR TERM...NOCERA SHORT TERM...BELK LONG TERM...JWD AVIATION...NOCERA/JWD MARINE...NOCERA/JWD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
206 PM EDT MON MAY 12 2014 .SYNOPSIS... HIGH PRESSURE REMAINS IN CONTROL THROUGH TODAY THEN A BACK DOOR COLD FRONT STARTS MOVING THROUGH THE REGION LATE TONIGHT INTO TUESDAY. MARITIME HIGH PRESSURE WEDNESDAY PROVIDES BELOW AVERAGE TEMPERATURES FOLLOWED BY A PERIOD OF UNSETTLED WEATHER THURSDAY THROUGH SATURDAY. BEST CHANCE OF HEAVY RAIN AND POSSIBLE THUNDERSTORMS EXPECTED FRIDAY NIGHT INTO SATURDAY. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... 2 PM UPDATE... TEMPS NOW IN THE LOW TO MID 80S AT 2 PM ACROSS THE INTERIOR IN RESPONSE TO DEEP BLYR MIXING WITH SURFACE WINDS WSW UP TO 20-25 MPH. AT THE COAST PGRAD WEAK ENOUGH TO SUPPORT A SSW WIND. HOWEVER TEMPS AT THE SHORE STILL WARM WITH READINGS 75-80! WATCHING AREA OF CLOUD DEVELOPMENT OVER PA WITH NOTICEABLE CYCLONIC SWIRL AS LOW AMPLITUDE SHORT WAVE MOVES ACROSS THIS AREA. THIS SHOWS UP NICELY ON THE SPC MESOANALYSIS ESPECIALLY AT H7. SHOWERS TRYING TO DEVELOP BUT INSTABILITY IS LACKING...BOTH AT THE SURFACE AND ALOFT. DEW PTS ACROSS SOUTHERN NEW ENGLAND REMAIN DRY WITH VALUES IN THE U30S AND L40S. SOME INSTABILITY OVER SOUTHERN NJ THAT MAY ADVECT NORTHEAST INTO NYC/LONG ISLAND. THUS ANY SHOWER ACTIVITY SHOULD SLIDE ACROSS PA/NJ/NYC...PERHAPS CLIPPING SOUTHWEST CT. THEREFORE EXPECTING SOUTHERN NEW ENGLAND TO REMAIN DRY THRU THIS EVENING. PREVIOUS DISCUSSION BELOW. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ANOTHER SPECTACULAR DAY IN PROGRESS WITH DEEP LAYER RIDGE OVER THE EASTERN GREAT LAKES AND SURFACE HIGH SOUTH OF NEW ENGLAND. THIS SETUP IS PROVIDING LARGE SCALE SUBSIDENCE OVER THE REGION ALONG WITH LOW LEVEL WESTERLY FLOW. THUS ABUNDANT SUNSHINE PREVAILS ALONG WITH COMFORTABLE HUMIDITY WITH DEW PTS IN THE 30S AND 40S. UPSTREAM SOUNDING AT ALBANY NY SUPPORTS HIGHS AROUND 80F WITH 850 TEMPS OF +11C. HOWEVER WITH BLYR EXTENDING UP TO 700 MB ALONG WITH WESTERLY BLYR WINDS HIGHS WILL CLIMB INTO THE M80S WITH A LOW PROBABILITY OF A FEW SPOTS BRIEFLY GETTING INTO THE U80S! THUS HAVE INCREASED HIGHS A TAD FROM PREVIOUS FORECAST. THINK DRY WEATHER WILL PREVAIL TODAY DESPITE BACKDOOR FRONT APPROACHING FROM MAINE. PREFRONTAL AIRMASS IS VERY DRY WITH DEW PTS IN THE 30S AND 40S. THIS RESULTS IN VERY LITTLE TO ANY AVAILABLE INSTABILITY. IN ADDITION AS BLYR DEEPENS WINDS BECOME WEST AND LIMIT SURFACE CONVERGENCE. HENCE DRY WEATHER SHOULD PREVAIL THRU SUNSET. THIS IS TYPICALLY THE CASE AHEAD OF BACKDOOR FRONTS. IN ADDITION LATEST HRRR KEEPS SOUTHERN NEW ENGLAND DRY THRU 23Z FOLLOWED BY A FEW POSSIBLE SHOWERS/TSTMS ZIPPING ACROSS WESTERN CT THEREAFTER. HOWEVER THIS IS A VERY LOW PROB. OTHERWISE PREVIOUS FORECAST IN GOOD SHAPE AND NO MAJOR CHANGES PLANNED. && .SHORT TERM /7 PM THIS EVENING THROUGH 6 PM TUESDAY/... TONIGHT...AN APPROACHING WARM FRONT WILL BE STALLED BY A LOW PRESSURE MOVING EAST INTO MAINE. ONCE THIS LOW PRESSURE MOVES QUICKLY EAST...A STRONG HIGH PRESSURE WILL START TO BUILD SOUTH ACROSS NORTHERN NEW ENGLAND. THIS HIGH PRESSURE WILL PUSH A BACK DOOR COLD FRONT INTO SOUTHERN NEW ENGLAND LATE TONIGHT INTO TUESDAY. WILL CONTINUE THE CHANCE FOR SOME SHOWERS INTO PARTS OF OUR REGION TONIGHT...AT LEAST UNTIL THE SUBSIDENCE BECOMES DOMINANT. THERE IS STILL SOME QUESTION AS TO WHEN THIS OCCURS... BUT THE LATEST THINKING IS IT MAY TAKE MOST OF THE NIGHT. COOLER OVERNIGHT TEMPERATURES ARE EXPECTED AS WINDS SHIFT TO THE NORTH AND NORTHEAST BEHIND THE BACK DOOR COLD FRONT. TUESDAY... BACK-DOOR COLD FRONT CONTINUES TO MOVE WEST AS A HIGH PRESSURE BUILDS OVER THE GULF OF MAINE. IT WILL TURN UNSEASONABLY COOL WITH ONSHORE FLOW OFF ROUGHLY UPPER 40S DEGREE WATER. LIKELY TO BE FAIRLY CLOUDY WITH A LONG FETCH OF EASTERLY FLOW UNDERGOING WEAK UPSLOPE AS OVERRUNNING REMAINS PREVALENT ALONG THE LOW- TO MID- LEVEL FRONTAL BOUNDARY SITUATED ACROSS AND TO THE WEST OF NEW ENGLAND. AS SUCH CANNOT COMPLETELY RULE OUT A STRAY SHOWER OR TWO. HOWEVER...EXPECTING MAINLY DRY CONDITIONS. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... HIGHLIGHTS... * HIGH PRESSURE ON WEDNESDAY WITH UNSEASONABLE TEMPS ALONG E COAST * SEASONABLE TEMPS AND UNSETTLED WEATHER THURSDAY THROUGH THE WEEKEND * POTENTIALLY TURNING CHILLY WITH SHOWERS INTO EARLY NEXT WEEK MODELS AND CONFIDENCE... LATEST 00Z GUIDANCE IS IN AGREEMENT SHOWING A STRONG WEST COAST RIDGE WHICH WILL SUPPORT A BROAD/DEEP TROUGH SETTLING OVER THE ERN HALF OF THE CONUS. CLOSER AT HOME...HIGH PRESSURE WILL BE BUILDING IN THE GULF OF MAINE ON WEDNESDAY ALLOWING FOR DRY WEATHER. AS THE TROUGH MOVES TOWARDS NEW ENGLAND...A NORTH ATLANTIC RIDGE WILL HOLD STEADY...AND EVENTUALLY BLOCKS THE PROGRESSION OF THE TROUGH. A SFC LOW PRES WILL INTENSIFIES OVER THE MID-ATLANTIC AS SEVERAL STRONG SHORTWAVES DIG INTO THE BASE OF THE TROUGH. THAT LOW WILL THEN SLIDE UP THE EAST COAST FRIDAY...AND DRAG A COLD FRONT ACROSS THE REGION FRIDAY NIGHT INTO SATURDAY. STILL A LOT OF TIMING ISSUES WITH THIS FORECAST BUT CONFIDENCE IS INCREASING THAT ASIDE FROM HIT OR MISS SHOWERS IN THE MEDIUM RANGE...THE LONG TERM WILL BE VERY UNSETTLED WITH POSSIBLE HEAVY RAIN/FLOODING ISSUES. SOLUTION SPREAD IS GRADUALLY NARROWING BUT GFS/GEFS ARE CONTINUING LEADING HGT FALLS INTO THE EAST FASTER THAN MOST OTHER GUIDANCE IN THE MID-LATE WEEK TIME FRAME. ALTHOUGH LATEST EC GUIDANCE IS ON THE SLOWER SIDE OF THE ENVELOPE WITH THE CMC ACTUALLY BEING IN THE MIDDLE OF THE SOLUTIONS AND ENSEMBLES. TRENDS AND CONTINUITY OVER MULTIPLE DAYS HAVE BEEN FAVORING SLOWER TIMING AS SUPPORTED BY THE AMPLIFIED NATURE OF THE APPROACHING TROUGH AS WELL AS BLOCKY PATTERN IN THE ATLANTIC...WHICH IS SUPPORTED WITH NAO TRENDING NEGATIVE. THEREFORE TRENDED THIS FORECAST TOWARDS THE ENSEMBLES AS WELL AS WPC. DETAILS... WEDNESDAY... HIGH PRESSURE WILL BUILD IN ACROSS THE GULF OF MAINE KEEPING MOST OF THE REGION DRY. TEMPS WILL BE SEASONABLE EXCEPT ALONG THE EASTERN COASTLINE AS ONSHORE FLOW WILL KEEP THE MARITIME AIR AROUND ON WEDNESDAY. HOWEVER STALLED BOUNDARY ACROSS CENTRAL NY MAY ALLOW FOR SOME ISO SHOWERS ACROSS WESTERN ZONES. THURSDAY INTO SATURDAY... STRONG ATLANTIC RIDGE TO THE EAST WILL SLOW THE PROGRESSION OF THE DIGGING TROUGH AND STALL IT JUST WEST OF THE REGION. HOWEVER BY THURSDAY...THE RIDGE WILL BREAK DOWN TEMPORARILY AS STRONG WESTERN RIDGE PUSHES THE TROUGH TOWARDS THE NORTHEAST. EXPECT SEVERAL WEAK WAVES TO DEVELOP AHEAD OF THIS TROUGH WHICH WILL APPROACH THE AREA. HIT OR MISS SHOWERS/T-STORMS POSSIBLE ON THURSDAY WITH MORE WIDESPREAD RAINFALL ON FRIDAY INTO SATURDAY. ALTHOUGH EXACT TIMING OF EACH WAVE IS STILL UNCERTAIN...IT APPEARS THAT THE BEST CHANCE FOR HIGHER PRECIP LOOKS TO BE FRIDAY NIGHT AS LOW PRESSURE SYSTEM DEVELOPS ALONG THE FRONT. STRONG LLJ AND INCREASING MOISTURE TRANSPORT SUPPORTS THE IDEA OF THE POSSIBILITY OF HEAVY RAINFALL. ESPECIALLY SINCE THE TROUGH IS TAPPING INTO DEEP GULF MOISTURE ALLOWING PWAT VALUES TO BE 3 STANDARD DEVIATIONS AWAY. INCREASING CONFIDENCE THAT HEAVY RAINFALL WILL OCCUR BUT THERE IS STILL SOME UNCERTAINTY ON EXACT TIMING...THEREFORE CONTINUED TO MENTION LIKELY POPS FOR FRIDAY INTO SATURDAY. ALSO A LOW CONFIDENCE ON FLOODING POTENTIAL AS FLASH FLOOD GUIDANCE IS APPROX 3 INCHES FOR MUCH OF THE AREA. IN FACT WPC IS FORECASTING 2.5 INCHES OF QPF. SO IF THIS FRONT STALLS/OR SLOWS DOWN ANY MORE WE MAY SEE SIGNIFICANT RAIN FALL AMOUNTS NEAR FLASH FLOOD GUIDANCE. A SEASONABLE BUT HUMID AIR MASS WILL OVERSPREAD THE REGION WITH SW FLOW TAPPING INTO THE GULF...ADVECTING HIGHER DEWPOINTS AHEAD OF THE TROUGH. FOG IS A POSSIBILITY ON WED NIGHT INTO THURSDAY AND AGAIN ON FRIDAY. HIGHS WILL GENERALLY TOP OFF IN THE UPPER 60S TO MID 70S WITH COOLER CONDITIONS ALONG THE COAST...ESP THE SOUTH COAST DUE TO SOUTHERLY FLOW. SUNDAY AND BEYOND... MODELS DIFFER ON THE TIMING ON THE EXIT OF THE SYSTEM LATE SATURDAY INTO SUNDAY. HAVE LOW CONFIDENCE ON WHEN THE FRONT WILL SWEEP EASTWARD AS A SLIGHT CHANGE IN THE PATH COULD LEAD TO A SIGNIFICANT CHANGE IN THE WEATHER FOR THE WEEKEND. OVERALL IT APPEARS THAT THE STRONG ATLANTIC HIGH PRESSURE WILL STALL THE SYSTEM JUST EAST OF THE REGION ON SUNDAY WITH AN UPPER LEVEL CUT OFF LOW FORMING. THIS LOW WILL KEEP THE REGION SHOWERY AS WELL AS COOLER DUE TO THE COLD CORE LOW WOBBLING OVER THE AREA. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY/...HIGH CONFIDENCE. THRU 00Z...VFR WITH SSW WINDS ALONG THE COAST AND WSW INLAND GUSTING UP TO 20 KT. DRY WEATHER PREVAILS WITH ANY SHOWERS/TSTMS DEVELOPING OVER PA MOVING INTO NJ/NYC/LONG ISLAND AND OFFSHORE. LOW PROBABILITY OF THIS ACTIVITY CLIPPING WESTERN CT. AFTER 00Z...BACKDOOR FRONT FROM MAINE MOVES SOUTHWEST-WARD INTO MA/RI/CT BEGINNING 01Z/02Z FIRST ACROSS NORTHEAST MA AND THEN SOUTHWEST-WARD AS THE EVENING PROGRESSES. FRONT WILL COME THRU DRY WITH ANY SHOWER ACTIVITY ACROSS THE LOWER HUDSON VALLEY OF NY/NYC/LONG ISLAND...POSSIBLY CLIPPING CT. TUE AND TUE NIGHT...VFR WITH MAINLY DRY WEATHER. ANY PRECIP WOULD BE VERY LIGHT IN THE FORM OF SPRINKLES. NE WINDS TUE WITH GUSTS UP TO 20 KT ALONG THE COAST...BECOME SE TUE NIGHT. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. S WINDS BECOME SW AS THE AFTERNOON PROGRESSES. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...WEDNESDAY THROUGH FRIDAY... WEDNESDAY...HIGH CONFIDENCE. EASTERLY WINDS. VFR WITH POSSIBLE MVFR CIGS ANTICIPATED. IFR OVERNIGHT IS POSSIBLE AS WINDS SWITCH BACK TO THE SOUTH. THURSDAY INTO FRIDAY...MODERATE CONFIDENCE. VFR FOR THURSDAY. CONDITIONS DETERIORATING FRIDAY TO IFR WITH INCREASING AREAL EXTENT OF SHRA AND POSSIBLE TSRA. SOUTHERLY WINDS ON THURSDAY CONTINUING INTO FRIDAY WITH GUSTS UP AROUND 25-30 KTS POSSIBLE. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. HIGH CONFIDENCE THROUGH TUESDAY. WINDS AND SEAS EXPECTED TO REMAIN BELOW SMALL CRAFT CRITERIA THROUGH TODAY. WINDS INCREASE AS A BACK DOOR COLD FRONT MOVES FROM NORTHEAST TO SOUTHWEST TONIGHT. SMALL CRAFT ADVISORIES MAY AGAIN BE NECESSARY FOR A TIME TONIGHT INTO TUESDAY...THOUGH SEAS LOOK TO REMAIN BELOW 5 FEET. AT THIS POINT...DO NOT HAVE ENOUGH CONFIDENCE IN REACHING 25 KT GUSTS OR 5 FOOT SEAS TO ISSUE SMALL CRAFT ADVISORIES NOW. IT DOES REMAIN A POSSIBILITY...AND IS SOMETHING FUTURE SHIFTS WILL HAVE TO CONSIDER. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. HIGH PRESSURE WILL BUILD OVER THE EASTERN WATERS TUESDAY NIGHT AND INTO WEDNESDAY. EXPECT EASTERLY WINDS TO CONTINUE...ALLOWING FOR EASTERLY SWELL TO BUILD. FOG AND DRIZZLE POSSIBLE BY LATE WEDNESDAY AS FLOW SWITCH TO THE SOUTH. SCA MAY BE NEEDED FOR THE PERIOD. THURSDAY INTO FRIDAY...LOW CONFIDENCE. LINGER 5FT SEAS TO START INCREASING THROUGHOUT THE DAY WITH THE POSSIBILITY FOR A FEW SHOWERS ON THURSDAY. CONDITIONS DETERIORATE ON FRIDAY AS FRONT APPROACHES THE WATERS. SEAS AND WINDS WILL BUILD IN RESPONSE AS WELL AS HEAVY DOWNPOURS AND ISO THUNDER. SCA WILL BE NEEDED. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...BELK/DUNTEN NEAR TERM...NOCERA SHORT TERM...BELK LONG TERM...DUNTEN AVIATION...NOCERA/DUNTEN MARINE...BELK/DUNTEN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1014 AM EDT MON MAY 12 2014 .SYNOPSIS... HIGH PRESSURE REMAINS IN CONTROL THROUGH TODAY THEN A BACK DOOR COLD FRONT STARTS MOVING THROUGH THE REGION LATE TONIGHT INTO TUESDAY. MARITIME HIGH PRESSURE WEDNESDAY PROVIDES BELOW AVERAGE TEMPERATURES FOLLOWED BY A PERIOD OF UNSETTLED WEATHER THURSDAY THROUGH SATURDAY. BEST CHANCE OF HEAVY RAIN AND POSSIBLE THUNDERSTORMS EXPECTED FRIDAY NIGHT INTO SATURDAY. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... 10 AM UPDATE... ANOTHER SPECTACULAR DAY IN PROGRESS WITH DEEP LAYER RIDGE OVER THE EASTERN GREAT LAKES AND SURFACE HIGH SOUTH OF NEW ENGLAND. THIS SETUP IS PROVIDING LARGE SCALE SUBSIDENCE OVER THE REGION ALONG WITH LOW LEVEL WESTERLY FLOW. THUS ABUNDANT SUNSHINE PREVAILS ALONG WITH COMFORTABLE HUMIDITY WITH DEW PTS IN THE 30S AND 40S. UPSTREAM SOUNDING AT ALBANY NY SUPPORTS HIGHS AROUND 80F WITH 850 TEMPS OF +11C. HOWEVER WITH BLYR EXTENDING UP TO 700 MB ALONG WITH WESTERLY BLYR WINDS HIGHS WILL CLIMB INTO THE M80S WITH A LOW PROBABILITY OF A FEW SPOTS BRIEFLY GETTING INTO THE U80S! THUS HAVE INCREASED HIGHS A TAD FROM PREVIOUS FORECAST. THINK DRY WEATHER WILL PREVAIL TODAY DESPITE BACKDOOR FRONT APPROACHING FROM MAINE. PREFRONTAL AIRMASS IS VERY DRY WITH DEW PTS IN THE 30S AND 40S. THIS RESULTS IN VERY LITTLE TO ANY AVAILABLE INSTABILITY. IN ADDITION AS BLYR DEEPENS WINDS BECOME WEST AND LIMIT SURFACE CONVERGENCE. HENCE DRY WEATHER SHOULD PREVAIL THRU SUNSET. THIS IS TYPICALLY THE CASE AHEAD OF BACKDOOR FRONTS. IN ADDITION LATEST HRRR KEEPS SOUTHERN NEW ENGLAND DRY THRU 23Z FOLLOWED BY A FEW POSSIBLE SHOWERS/TSTMS ZIPPING ACROSS WESTERN CT THEREAFTER. HOWEVER THIS IS A VERY LOW PROB. OTHERWISE PREVIOUS FORECAST IN GOOD SHAPE AND NO MAJOR CHANGES PLANNED. && .SHORT TERM /7 PM THIS EVENING THROUGH 6 PM TUESDAY/... TONIGHT...AN APPROACHING WARM FRONT WILL BE STALLED BY A LOW PRESSURE MOVING EAST INTO MAINE. ONCE THIS LOW PRESSURE MOVES QUICKLY EAST...A STRONG HIGH PRESSURE WILL START TO BUILD SOUTH ACROSS NORTHERN NEW ENGLAND. THIS HIGH PRESSURE WILL PUSH A BACK DOOR COLD FRONT INTO SOUTHERN NEW ENGLAND LATE TONIGHT INTO TUESDAY. WILL CONTINUE THE CHANCE FOR SOME SHOWERS INTO PARTS OF OUR REGION TONIGHT...AT LEAST UNTIL THE SUBSIDENCE BECOMES DOMINANT. THERE IS STILL SOME QUESTION AS TO WHEN THIS OCCURS... BUT THE LATEST THINKING IS IT MAY TAKE MOST OF THE NIGHT. COOLER OVERNIGHT TEMPERATURES ARE EXPECTED AS WINDS SHIFT TO THE NORTH AND NORTHEAST BEHIND THE BACK DOOR COLD FRONT. TUESDAY... BACK-DOOR COLD FRONT CONTINUES TO MOVE WEST AS A HIGH PRESSURE BUILDS OVER THE GULF OF MAINE. IT WILL TURN UNSEASONABLY COOL WITH ONSHORE FLOW OFF ROUGHLY UPPER 40S DEGREE WATER. LIKELY TO BE FAIRLY CLOUDY WITH A LONG FETCH OF EASTERLY FLOW UNDERGOING WEAK UPSLOPE AS OVERRUNNING REMAINS PREVALENT ALONG THE LOW- TO MID- LEVEL FRONTAL BOUNDARY SITUATED ACROSS AND TO THE WEST OF NEW ENGLAND. AS SUCH CANNOT COMPLETELY RULE OUT A STRAY SHOWER OR TWO. HOWEVER...EXPECTING MAINLY DRY CONDITIONS. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... HIGHLIGHTS... * HIGH PRESSURE ON WEDNESDAY WITH UNSEASONABLE TEMPS ALONG E COAST * SEASONABLE TEMPS AND UNSETTLED WEATHER THURSDAY THROUGH THE WEEKEND * POTENTIALLY TURNING CHILLY WITH SHOWERS INTO EARLY NEXT WEEK MODELS AND CONFIDENCE... LATEST 00Z GUIDANCE IS IN AGREEMENT SHOWING A STRONG WEST COAST RIDGE WHICH WILL SUPPORT A BROAD/DEEP TROUGH SETTLING OVER THE ERN HALF OF THE CONUS. CLOSER AT HOME...HIGH PRESSURE WILL BE BUILDING IN THE GULF OF MAINE ON WEDNESDAY ALLOWING FOR DRY WEATHER. AS THE TROUGH MOVES TOWARDS NEW ENGLAND...A NORTH ATLANTIC RIDGE WILL HOLD STEADY...AND EVENTUALLY BLOCKS THE PROGRESSION OF THE TROUGH. A SFC LOW PRES WILL INTENSIFIES OVER THE MID-ATLANTIC AS SEVERAL STRONG SHORTWAVES DIG INTO THE BASE OF THE TROUGH. THAT LOW WILL THEN SLIDE UP THE EAST COAST FRIDAY...AND DRAG A COLD FRONT ACROSS THE REGION FRIDAY NIGHT INTO SATURDAY. STILL A LOT OF TIMING ISSUES WITH THIS FORECAST BUT CONFIDENCE IS INCREASING THAT ASIDE FROM HIT OR MISS SHOWERS IN THE MEDIUM RANGE...THE LONG TERM WILL BE VERY UNSETTLED WITH POSSIBLE HEAVY RAIN/FLOODING ISSUES. SOLUTION SPREAD IS GRADUALLY NARROWING BUT GFS/GEFS ARE CONTINUING LEADING HGT FALLS INTO THE EAST FASTER THAN MOST OTHER GUIDANCE IN THE MID-LATE WEEK TIME FRAME. ALTHOUGH LATEST EC GUIDANCE IS ON THE SLOWER SIDE OF THE ENVELOPE WITH THE CMC ACTUALLY BEING IN THE MIDDLE OF THE SOLUTIONS AND ENSEMBLES. TRENDS AND CONTINUITY OVER MULTIPLE DAYS HAVE BEEN FAVORING SLOWER TIMING AS SUPPORTED BY THE AMPLIFIED NATURE OF THE APPROACHING TROUGH AS WELL AS BLOCKY PATTERN IN THE ATLANTIC...WHICH IS SUPPORTED WITH NAO TRENDING NEGATIVE. THEREFORE TRENDED THIS FORECAST TOWARDS THE ENSEMBLES AS WELL AS WPC. DETAILS... WEDNESDAY... HIGH PRESSURE WILL BUILD IN ACROSS THE GULF OF MAINE KEEPING MOST OF THE REGION DRY. TEMPS WILL BE SEASONABLE EXCEPT ALONG THE EASTERN COASTLINE AS ONSHORE FLOW WILL KEEP THE MARITIME AIR AROUND ON WEDNESDAY. HOWEVER STALLED BOUNDARY ACROSS CENTRAL NY MAY ALLOW FOR SOME ISO SHOWERS ACROSS WESTERN ZONES. THURSDAY INTO SATURDAY... STRONG ATLANTIC RIDGE TO THE EAST WILL SLOW THE PROGRESSION OF THE DIGGING TROUGH AND STALL IT JUST WEST OF THE REGION. HOWEVER BY THURSDAY...THE RIDGE WILL BREAK DOWN TEMPORARILY AS STRONG WESTERN RIDGE PUSHES THE TROUGH TOWARDS THE NORTHEAST. EXPECT SEVERAL WEAK WAVES TO DEVELOP AHEAD OF THIS TROUGH WHICH WILL APPROACH THE AREA. HIT OR MISS SHOWERS/T-STORMS POSSIBLE ON THURSDAY WITH MORE WIDESPREAD RAINFALL ON FRIDAY INTO SATURDAY. ALTHOUGH EXACT TIMING OF EACH WAVE IS STILL UNCERTAIN...IT APPEARS THAT THE BEST CHANCE FOR HIGHER PRECIP LOOKS TO BE FRIDAY NIGHT AS LOW PRESSURE SYSTEM DEVELOPS ALONG THE FRONT. STRONG LLJ AND INCREASING MOISTURE TRANSPORT SUPPORTS THE IDEA OF THE POSSIBILITY OF HEAVY RAINFALL. ESPECIALLY SINCE THE TROUGH IS TAPPING INTO DEEP GULF MOISTURE ALLOWING PWAT VALUES TO BE 3 STANDARD DEVIATIONS AWAY. INCREASING CONFIDENCE THAT HEAVY RAINFALL WILL OCCUR BUT THERE IS STILL SOME UNCERTAINTY ON EXACT TIMING...THEREFORE CONTINUED TO MENTION LIKELY POPS FOR FRIDAY INTO SATURDAY. ALSO A LOW CONFIDENCE ON FLOODING POTENTIAL AS FLASH FLOOD GUIDANCE IS APPROX 3 INCHES FOR MUCH OF THE AREA. IN FACT WPC IS FORECASTING 2.5 INCHES OF QPF. SO IF THIS FRONT STALLS/OR SLOWS DOWN ANY MORE WE MAY SEE SIGNIFICANT RAIN FALL AMOUNTS NEAR FLASH FLOOD GUIDANCE. A SEASONABLE BUT HUMID AIR MASS WILL OVERSPREAD THE REGION WITH SW FLOW TAPPING INTO THE GULF...ADVECTING HIGHER DEWPOINTS AHEAD OF THE TROUGH. FOG IS A POSSIBILITY ON WED NIGHT INTO THURSDAY AND AGAIN ON FRIDAY. HIGHS WILL GENERALLY TOP OFF IN THE UPPER 60S TO MID 70S WITH COOLER CONDITIONS ALONG THE COAST...ESP THE SOUTH COAST DUE TO SOUTHERLY FLOW. SUNDAY AND BEYOND... MODELS DIFFER ON THE TIMING ON THE EXIT OF THE SYSTEM LATE SATURDAY INTO SUNDAY. HAVE LOW CONFIDENCE ON WHEN THE FRONT WILL SWEEP EASTWARD AS A SLIGHT CHANGE IN THE PATH COULD LEAD TO A SIGNIFICANT CHANGE IN THE WEATHER FOR THE WEEKEND. OVERALL IT APPEARS THAT THE STRONG ATLANTIC HIGH PRESSURE WILL STALL THE SYSTEM JUST EAST OF THE REGION ON SUNDAY WITH AN UPPER LEVEL CUT OFF LOW FORMING. THIS LOW WILL KEEP THE REGION SHOWERY AS WELL AS COOLER DUE TO THE COLD CORE LOW WOBBLING OVER THE AREA. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY/...HIGH CONFIDENCE. VFR. VERY LOW PROB OF AN ISOLATED SHOWER/TSTM NEAR BDL/BAF TOWARD 00Z. OTHERWISE DRY WEATHER PREVAILS. LIGHT/VARIABLE WINDS THIS MORNING BECOME WESTERLY THIS AFTERNOON. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. LIGHT/VARIABLE WINDS BECOME WEST BY NOON. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... TUESDAY NIGHT INTO WEDNESDAY...HIGH CONFIDENCE. EASTERLY WINDS. VFR WITH POSSIBLE MVFR CIGS ANTICIPATED. IFR OVERNIGHT IS POSSIBLE AS WINDS SWITCH BACK TO THE SOUTH. THURSDAY INTO FRIDAY...MODERATE CONFIDENCE. VFR FOR THURSDAY. CONDITIONS DETERIORATING FRIDAY TO IFR WITH INCREASING AREAL EXTENT OF SHRA AND POSSIBLE TSRA. SOUTHERLY WINDS ON THURSDAY CONTINUING INTO FRIDAY WITH GUSTS UP AROUND 25-30 KTS POSSIBLE. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. HIGH CONFIDENCE THROUGH TUESDAY. WINDS AND SEAS EXPECTED TO REMAIN BELOW SMALL CRAFT CRITERIA THROUGH TODAY. WINDS INCREASE AS A BACK DOOR COLD FRONT MOVES FROM NORTHEAST TO SOUTHWEST TONIGHT. SMALL CRAFT ADVISORIES MAY AGAIN BE NECESSARY FOR A TIME TONIGHT INTO TUESDAY...THOUGH SEAS LOOK TO REMAIN BELOW 5 FEET. AT THIS POINT...DO NOT HAVE ENOUGH CONFIDENCE IN REACHING 25 KT GUSTS OR 5 FOOT SEAS TO ISSUE SMALL CRAFT ADVISORIES NOW. IT DOES REMAIN A POSSIBILITY...AND IS SOMETHING FUTURE SHIFTS WILL HAVE TO CONSIDER. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. HIGH PRESSURE WILL BUILD OVER THE EASTERN WATERS TUESDAY NIGHT AND INTO WEDNESDAY. EXPECT EASTERLY WINDS TO CONTINUE...ALLOWING FOR EASTERLY SWELL TO BUILD. FOG AND DRIZZLE POSSIBLE BY LATE WEDNESDAY AS FLOW SWITCH TO THE SOUTH. SCA MAY BE NEEDED FOR THE PERIOD. THURSDAY INTO FRIDAY...LOW CONFIDENCE. LINGER 5FT SEAS TO START INCREASING THROUGHOUT THE DAY WITH THE POSSIBILITY FOR A FEW SHOWERS ON THURSDAY. CONDITIONS DETERIORATE ON FRIDAY AS FRONT APPROACHES THE WATERS. SEAS AND WINDS WILL BUILD IN RESPONSE AS WELL AS HEAVY DOWNPOURS AND ISO THUNDER. SCA WILL BE NEEDED. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...BELK/DUNTEN NEAR TERM...BELK/NOCERA/DUNTEN SHORT TERM...BELK LONG TERM...DUNTEN AVIATION...BELK/NOCERA/DUNTEN MARINE...BELK/DUNTEN
AREA FORECAST DISCUSSION
NWS ALBANY NY
924 AM EDT MON MAY 12 2014 .SYNOPSIS...HIGH PRESSURE SLIDES OUT TO SEA OFF THE MID ATLANTIC COAST TODAY. AFTER A DELIGHTFULL SUNNY WARM DAY OUR WEATHER WILL TURN INCREASINGLY UNSETTLED AS THE WEEK PROGRESSES. LATE TODAY A BACK DOOR COLD FRONT WILL DROP SOUTH THROUGH THE REGION...STALLING ACROSS THE MID ATLANTIC STATES. BY MIDWEEK A LARGE FRONTAL SYSTEM IN THE GREAT LAKES WILL PUSH TOWARD THE EASTERN SEABOARD. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 915AM SOME HI CLOUDS ASSOC WITH CONVECTIVE DEBRIS FROM THE OVERNIGHT OHIO MCS WERE SPILLING OVER S PRTNS OF FCA...BUT THESE SHOULD THIN AND SHIFT SOUTH DURING THE REST OF THE DAY...UNTIL THE NEXT RIDGE ROLLER STARTS SPILLING CI/MID INTO FCA TWRD EVNG. TEMPS ARE A FEW DEG ABV CURRENT FCST...AND NUDGED MAXES 1-3 DEG BASED ON CURRENT TEMPS AND 06UTC MOS/MET. HRRR AND LOCAL WRF REFLECTIVITIES SUGGEST STILL THE POTENTIAL FOR SOME SHOWERS DEVELOPING ACROSS THE CATSKILLS. ALTHOUGH CONVECTIVE TEMP AT ALB ON MRNG SNDGS IS 103F. WILL CONT POPS BUT LOWERED TO SLGT CHC THERE. THE IR SATELLITE IMAGERY ALONG WITH SURFACE FRONT ANALYSIS REVEALS A BACKDOOR COLD FRONT HAS REACHED THE ST LAWRENCE VALLEY. ONE MCS THAT MOVED THROUGH OHIO INTO WV HAS DISSIPATED TO -SHRA AND CLOUDS...ANOTHER MOVING FM WI INTO MICHIGAN IS ALSO WEAKENING. COMBINATION OF THIS FRONT AND CONVECTIVE CLOUD DEBRIS WILL BRING AN INCREASE IN HIGH AND MID LEVEL MOISTURE ACROSS THE REGION LATE TODAY. CLOUD OPAQUENESS WILL VARY BUT ENOUGH SUNSHINE SHOULD RESULT IN A RATHER MILD AFTERNOON WITH HIGHS AT OR JUST ABOVE 80F FOR SEVERAL VALLEY LOCATIONS AND MAINLY 70S FOR THE REMAINDER OF THE REGION. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... INTO THIS EVENING...EXPERIENTIAL HIRES REFLECTIVITY FORECASTS FROM SPC/HRRR/WRF SUGGEST WIDESPREAD CONVECTION DEVELOPS ALONG A WARM FRONT NEAR THE NY/PA BORDER WITH ADDITIONAL SHOWER ACTIVITY ALONG THE BACKDOOR COLD FRONT INTO THE DACKS. WE WILL INCREASE POPS INTO THE SLIGHT CHANCE TO CHANCE CATEGORY FOR THE REGION WITH THE HIGHER VALUES INTO THE CATSKILLS AND MID HUDSON VALLEY. OTHERWISE...THERE WILL BE A NOTABLE INCREASE AND THICKENING CLOUD COVER ACROSS THE REGION WITH NEAR SEASONABLE OVERNIGHT LOWS FOR THE REGION WITH SLIGHTLY COOLER VALUES ACROSS THE LAKE GEORGE SARATOGA REGION AND WESTERN NEW ENGLAND AS SURFACE HIGH ACROSS NORTHEAST CANADA IS EXPECTED TO BUILD AND CREST INTO NEW ENGLAND TONIGHT. TUESDAY THROUGH WEDNESDAY...CONFIDENCE IS NOT PARTICULARLY HIGH WITH RESPECT TO PLACEMENT OF HIGHER PROBABILITIES OF SHOWERS/TSTORMS. NCEP MODEL SUITE AND INTERNATIONAL GUIDANCE FAVOR AN IDEA OF A WARM FRONT LIFTING EAST-NORTHEAST ACROSS THE REGION WITH RISING HEIGHTS ALOFT FOR A MORE ANTICYCLONIC FLOW. FURTHERMORE...BEST LOW LEVEL JET FORCING AND THETA-E ADVECTIVE PROPERTIES REMAIN UPSTREAM FROM THE LOCAL SERVICE AREA WHICH TOO LIMITS A MORE ORGANIZED PRECIPITATION EVENT. SO WE WILL KEEP POPS INTO THE SLIGHT CHANCE FOR PORTIONS OF NEW ENGLAND TO CHC-SCT VALUES FOR EASTERN NY /THE HIGHER POP VALUES WEST OF THE HUDSON RIVER/. GIVEN THE CONSIDERABLE CLOUD COVER EXPECTED...WE WILL KEEP TEMPERATURES AROUND SEASONABLE LEVELS DURING THIS TIME FRAME WITH A BLEND OF THE WARMER MAV GUIDANCE AND COOLER MET GUIDANCE WHICH IS SOMEWHAT CLOSE TO THE EXPERIMENTAL ECMWF MOS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... STRONG RIDGING WILL BE DEPARTING THE EASTERN SEABOARD AT THE START OF THE EXTENDED PERIOD...WHILE A DIGGING TROUGH MOVES ACROSS THE UPPER MIDWEST/GREAT PLAINS AND TOWARDS THE GREAT LAKES AND OHIO VALLEY. INITIALLY...THE BEST FORCING FOR PRECIP WILL BE LOCATED WEST OF OUR AREA...AND WHILE SOME STRAY SHOWERS/THUNDERSTORMS CANT BE RULED OUT FOR WESTERN PARTS OF THE CWA...IT LOOKS TO BE MAINLY DRY AND MILD FOR WED NIGHT INTO THURSDAY. MINS ON WED NIGHT WILL BE IN THE 50S...WITH HIGHS ON THURSDAY WELL INTO THE 70S...AS 850 HPA TEMPS OF 12-14 DEGREES C WILL SUPPORT QUITE A WARM DAY. EVENTUALLY...THE UPPER LEVEL TROUGH AND ASSOCIATED SLOW MOVING SFC FRONT WILL MOVE CLOSER TO OUR AREA AND PASS THROUGH FROM WEST TO EAST FOR THE LATE WEEK PERIOD. THIS WILL LIKELY BRING A BAND OF HEAVY RAIN SHOWERS ACROSS OUR REGION FOR SOMETIME BETWEEN THURSDAY NIGHT AND SATURDAY MORNING. WITH PWAT VALUES SURGING TO AROUND 1.50 INCHES...A PERIOD OF HEAVY RAIN WILL BE POSSIBLE WHEN THE BEST FORCING MOVES ACROSS THE AREA. IN ADDITION...THERE MAY BE SOME EMBEDDED CONVECTIVE ELEMENTS WITHIN THE BAND OF HEAVY RAIN SHOWERS...AS SHOWALTER VALUES DROPPING BELOW ZERO SHOW THERE MAY BE ELEVATED INSTABILITY...WHICH CAN ALSO CONTRIBUTE TO THE HEAVY RAIN POTENTIAL. IT WILL BE MILD AHEAD OF THE FRONTAL BOUNDARY WITH MINS IN THE MID 50S TO LOW 60S FOR THURSDAY NIGHT...AND TEMPS NEAR 70 ON FRIDAY. COOLER TEMPS WILL START TO MOVE IN FROM THE WEST FOR FRIDAY NIGHT...AS THE BOUNDARY STARTS TO CROSS THE REGION...WITH MID 40S TO MID 50S...AND HIGHS ON SATURDAY MAINLY IN THE 60S. OVER THE WEEKEND...THERE MAY BE SOME LINGERING RAIN SHOWERS...AS THE UPPER LEVEL TROUGH WILL STILL BE MOVING ACROSS THE AREA. IT/S STILL HARD TO SAY IF THE CORE OF THE UPPER LEVEL CLOSES OFF AND IF IT WILL CROSS OVER OUR AREA...OR IF IT WILL JUST PASS OFF TO OUR NORTH. IN EITHER CASE...A CONTINUED CHANCE FOR RAIN SHOWERS IS JUSTIFIED...ALONG WITH COOLER TEMPS FOR SAT NIGHT INTO SUNDAY. && .AVIATION /13Z MONDAY THROUGH FRIDAY/... A BATCH OF SCT-BKN MID LEVEL CLOUDS AROUND 10 KFT HAVE MOVED ACROSS THE REGION EARLY THIS MORNING. THESE CLOUDS HAVE STARTED TO THIN OUT AND MOVE AWAY FOR NOW...BUT SOME ADDITIONAL MID AND HIGH LEVEL CLOUDS CAN BE SEEN UPSTREAM ON IR SATELLITE IMAGERY. DURING THE DAY TODAY...SOME DIURNAL CU WILL DEVELOP...ALONG WITH THE AFOREMENTIONED PASSING MID AND HIGH LEVEL CLOUDS. VFR CONDITIONS WILL CONTINUE FOR ALL TERMINALS THROUGHOUT THE ENTIRE DAY. AT THIS POINT...THE THREAT FOR RAIN SHOWERS APPEARS TO BE MINIMAL...AS ANY ACTIVITY SHOULD REMAIN TO THE WEST OF THE HUDSON VALLEY TAF SITES...SO NO RAIN SHOWERS WILL BE MENTIONED IN THE TAF AT THIS TIME. WINDS FROM A W-SW DIRECTION WILL INCREASE TO ABOUT 5-10 KTS DURING THE BEST DAYTIME MIXING IN THE AFTN/EARLY EVENING. BY EVENING...MID LEVEL CLOUDS WILL INCREASE AND BECOME BKN FOR ALL SITES. WINDS WILL SWITCH TO A N-NW DIRECTION AS A BACKDOOR FRONTAL BOUNDARY MOVES THROUGH THE AREA...BUT WIND SPEEDS SHOULD DECREASE TO 5 KTS OR LESS FOR TONIGHT. THE THREAT FOR RAIN SHOWERS CONTINUES TO BE RATHER LOW...SO WILL CONTINUE WITH A DRY TAF FORECAST FOR TONIGHT WITH CONTINUED VFR CONDITIONS. OUTLOOK... TUESDAY THROUGH THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. FRIDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA. FRIDAY NIGHT THROUGH SATURDAY: MODERATE OPERATIONAL IMPACT. LIKELY SHRA. && .FIRE WEATHER... RH VALUES TODAY WILL LOWER TO BETWEEN 25 AND 35 PERCENT AS HIGH TEMPERATURES REACH THE MID 70S TO LOWER 80S. WINDS ARE EXPECTED TO BE 10 MPH OR LESS. THERE IS A CHANCE OF SHOWERS DURING THE LATE AFTERNOON HOURS. THE RH LEVELS RECOVER TONIGHT TO BETWEEN 60 AND 90 PERCENT TONIGHT WITH A LIGHT WIND. THE CHANCE FOR SHOWERS WILL CONTINUE FOR THE ENTIRE REGION WITH THE HIGHER PROBABILITIES WEST OF THE HUDSON RIVER. && .HYDROLOGY... NO WIDESPREAD HYDROLOGIC ISSUES ARE EXPECTED OVER THE NEXT SEVERAL DAYS. A MAINLY DRY AND WARM DAY IS EXPECTED TODAY WITH THE CHANCE FOR SHOWERS ON THE INCREASE LATE IN THE DAY. THIS CHANCE FOR SHOWERS WILL CONTINUE FOR MOST THE REGION WITH THE INCREASE PROBABILITY FOR SOME HEAVIER RAINFALL TOWARD THE END OF THIS WEEK. HOWEVER...ANY RAINFALL DURING THE EARLY AND MIDDLE PART OF THE WEEK WILL BE LIGHT AND HAVE LITTLE IMPACT ON AREA STREAMS AND RIVERS. THE RAINFALL LATER IN THE WEEK COULD BE HEAVY AND WE WILL NEED TO WATCH NUMERICAL TRENDS CLOSELY. 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...SNYDER NEAR TERM...BGM/SNYDER SHORT TERM...BGM LONG TERM...FRUGIS AVIATION...FRUGIS FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
147 PM EDT MON MAY 12 2014 .PREV DISCUSSION... UPDATE... /ISSUED 1046 AM EDT MON MAY 12 2014/ HI RES MODELS ARE STILL IN GOOD AGREEMENT WITH ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON BUT SOME DIFFERENCES IN TIMING. HRRR IS QUICKER WITH INITIALIZATION THAN THE LOCAL WRF...16Z COMPARED TO ABOUT 20Z. OVERALL THE POP FORECAST IS ON TRACK AND DID NOT ADJUST THE SLIGHT CHANCE/CHANCE FOR THIS AFTERNOON. I DID HOWEVER END UP PUSHING BACK THE INITIATION TO 17Z. FORECAST DEW POINTS WERE A LITTLE ON THE LOW SIDE SO INCREASED THEM INTO THE AFTERNOON. 11 SHORT TERM /TODAY THROUGH TUESDAY/... WEAK UPPER-LEVEL RIDGING CONTINUES OVER THE REGION TODAY...THEN BEGINS SHIFTING EAST INTO THE WESTERN ATLANTIC TUESDAY. THE RIDGE DOES NOT APPEAR TO BE DOMINANT ENOUGH TO SHUT OFF ALL CHANCES FOR CONVECTION BUT SHOULD LIMIT COVERAGE TO SCATTERED AT BEST AND DIURNALLY ORIENTED. MID-LEVEL LAPSE RATES AROUND 6DEGC/KM OR LESS KEEP INSTABILITY LIMITED WITH ANY THUNDERSTORMS EXPECTED TO REMAIN BELOW SEVERE LIMITS. FOR EARLY THIS MORNING...LOW-LEVEL MOISTURE AND MOIST SOILS ONCE AGAIN CONTRIBUTING TO AREAS OF FOG WITH PATCHY AREAS OF DENSE FOG. COVERAGE IS LESS THAN YESTERDAY MORNING AND IS EXPECTED TO REMAIN SO THIS MORNING AND IT DOES NOT APPEAR THAT THE AREAL COVERAGE OF VISIBILITIES BELOW 1/4 MILE WOULD BE SUFFICIENT FOR A DENSE FOG ADVISORY. 20 LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... LARGE HIGH AMPLITUDE H5 TROUGH OVER CENTRAL US FCST TO CONTINUE PROGRESSING SLOWLY EASTWARD REST OF THE WEEK. BY 12Z WED...TROUGH AXIS WILL STILL BE CENTERED ALONG 90W LONGITUDE BUT SWLY FLOW ALOFT AND WARM/MOIST ADVECTION AHEAD OF IT WILL INCREASE ACROSS THE SE STATES BRINGING CLOUDS AND SOME SCT SHRA WITH IT. INSTABILITY QUITE HIGH OVER THE CENTRAL STATES. HOWEVER AS THE TROUGH PUSHES EAST EACH DAY...LOW LEVEL FLOW PROGGED TO WEAKEN AND INSTABILITY DECREASES SOME. BY 12Z THURSDAY WHEN THE FRONT ASSOCIATED WITH THE UPPER TROUGH MOVES INTO THE STATE...MLCAPE VALUES ONLY AROUND 250-500 J/KG AND 0-1KM BULK SHEAR ONLY 10-20KTS. COULD ALSO SEE UPSTREAM CONVECTION ALONG THE CENTRAL GULF COAST AGAIN INHIBIT STORM DEVELOPMENT INLAND. DEEP SHEAR PROGGED TO REMAIN QUITE STRONG WITH 0-6KM BULK SHEAR 12Z THUR 40-50KTS...INDICATIVE OF STRONG TEMP GRADIENT ALONG FRONT AS WELL. EVEN WITH STRONG DEEP SHEAR...WITH LACK OF INSTABILITY AND LOW LEVEL SHEAR...SVR STORMS APPEAR UNLIKELY AT THIS TIME. COULD SEE PERIOD OF MDT TO HEAVY RAIN ON THURS...BUT WITH SLOW PROGRESSIVE NATURE OF SYSTEM...APPEARS ANY ONE AREA SHOULD NOT SEE MORE THAN 2 INCHES THROUGH 12Z FRI. AFTER FRONT AND ASSOCD SHORT WAVE PUSH THROUGH...UPPER TROUGH SLOW TO PUSH OUT OF EASTERN CONUS. ANOTHER WAVE IN NW FLOW OVER THE CENTRAL PLAINS PROGGED TO MOVE INTO THE TN VALLEY SAT. QUITE A BIT OF DISCREPANCY BETWEEN MED RANGE MODELS /00Z GFS...ECMWF AND CMC/ ON THIS FEATURE...ECMWF SOMEWHAT SLOWER. WITH DRY AIR MASS EXPECTED AS THIS SECOND WAVE APPROACHES...HAVE BACKED OFF A LITTLE ON POPS. NW FLOW CAN BE TRICKY IN THE WARM SEASON SO WILL NEED TO MONITOR THIS. INSTABILITY PROGGED TO BE LOW BUT NOT ZERO. SNELSON && .AVIATION... 18Z UPDATE... WINDS WILL REMAIN SOUTHERLY THROUGH THIS EVENING AND WILL BE VRB AROUND SOUTH. OVERALL THOUGH...TREND SHOULD BE TOWARDS SSW THIS AFTERNOON AND TRANSITION TO SSE THIS EVENING. POP UP SHOWERS ARE DEVELOPING ACROSS THE AREA. FOR THE MOST PART...AM HANDLING THIS WITH A TEMPO SHRA FOR THE BEST TIMING /18-23Z RANGE/. THERE IS A CHANCE OF TS BUT NOT HIGH ENOUGH AT THIS POINT TO MENTION IN THE TAFS. //ATL CONFIDENCE...18Z UPDATE... LOW CONFIDENCE ON WIND DIRECTION DUE TO VARIABILITY AROUND SOUTH. HIGH CONFIDENCE ON CIGS. HIGH CONFIDENCE ON VSBYS EXCEPT MEDIUM DURING THE MORNING. MEDIUM CONFIDENCE ON SHRA OCCURRING AT THE AIRPORT. 11 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 89 65 88 64 / 30 20 20 20 ATLANTA 87 68 86 66 / 30 20 20 20 BLAIRSVILLE 84 61 83 62 / 30 20 30 20 CARTERSVILLE 87 63 86 65 / 30 20 20 20 COLUMBUS 91 68 90 67 / 30 20 20 10 GAINESVILLE 85 66 84 65 / 30 20 20 20 MACON 90 65 89 65 / 30 20 20 10 ROME 87 63 86 63 / 30 20 30 20 PEACHTREE CITY 89 64 88 63 / 30 20 20 20 VIDALIA 90 67 89 68 / 30 20 20 10 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...11 LONG TERM....NLISTEMAA AVIATION...11
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1046 AM EDT MON MAY 12 2014 .UPDATE... HI RES MODELS ARE STILL IN GOOD AGREEMENT WITH ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON BUT SOME DIFFERENCES IN TIMING. HRRR IS QUICKER WITH INITIALIZATION THAN THE LOCAL WRF...16Z COMPARED TO ABOUT 20Z. OVERALL THE POP FORECAST IS ON TRACK AND DID NOT ADJUST THE SLIGHT CHANCE/CHANCE FOR THIS AFTERNOON. I DID HOWEVER END UP PUSHING BACK THE INITIATION TO 17Z. FORECAST DEW POINTS WERE A LITTLE ON THE LOW SIDE SO INCREASED THEM INTO THE AFTERNOON. 11 && .PREV DISCUSSION... /ISSUED 740 AM EDT MON MAY 12 2014/ SHORT TERM /TODAY THROUGH TUESDAY/... WEAK UPPER-LEVEL RIDGING CONTINUES OVER THE REGION TODAY...THEN BEGINS SHIFTING EAST INTO THE WESTERN ATLANTIC TUESDAY. THE RIDGE DOES NOT APPEAR TO BE DOMINANT ENOUGH TO SHUT OFF ALL CHANCES FOR CONVECTION BUT SHOULD LIMIT COVERAGE TO SCATTERED AT BEST AND DIURNALLY ORIENTED. MID-LEVEL LAPSE RATES AROUND 6DEGC/KM OR LESS KEEP INSTABILITY LIMITED WITH ANY THUNDERSTORMS EXPECTED TO REMAIN BELOW SEVERE LIMITS. FOR EARLY THIS MORNING...LOW-LEVEL MOISTURE AND MOIST SOILS ONCE AGAIN CONTRIBUTING TO AREAS OF FOG WITH PATCHY AREAS OF DENSE FOG. COVERAGE IS LESS THAN YESTERDAY MORNING AND IS EXPECTED TO REMAIN SO THIS MORNING AND IT DOES NOT APPEAR THAT THE AREAL COVERAGE OF VISIBILITIES BELOW 1/4 MILE WOULD BE SUFFICIENT FOR A DENSE FOG ADVISORY. 20 LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... LARGE HIGH AMPLITUDE H5 TROUGH OVER CENTRAL US FCST TO CONTINUE PROGRESSING SLOWLY EASTWARD REST OF THE WEEK. BY 12Z WED...TROUGH AXIS WILL STILL BE CENTERED ALONG 90W LONGITUDE BUT SWLY FLOW ALOFT AND WARM/MOIST ADVECTION AHEAD OF IT WILL INCREASE ACROSS THE SE STATES BRINGING CLOUDS AND SOME SCT SHRA WITH IT. INSTABILITY QUITE HIGH OVER THE CENTRAL STATES. HOWEVER AS THE TROUGH PUSHES EAST EACH DAY...LOW LEVEL FLOW PROGGED TO WEAKEN AND INSTABILITY DECREASES SOME. BY 12Z THURSDAY WHEN THE FRONT ASSOCIATED WITH THE UPPER TROUGH MOVES INTO THE STATE...MLCAPE VALUES ONLY AROUND 250-500 J/KG AND 0-1KM BULK SHEAR ONLY 10-20KTS. COULD ALSO SEE UPSTREAM CONVECTION ALONG THE CENTRAL GULF COAST AGAIN INHIBIT STORM DEVELOPMENT INLAND. DEEP SHEAR PROGGED TO REMAIN QUITE STRONG WITH 0-6KM BULK SHEAR 12Z THUR 40-50KTS...INDICATIVE OF STRONG TEMP GRADIENT ALONG FRONT AS WELL. EVEN WITH STRONG DEEP SHEAR...WITH LACK OF INSTABILITY AND LOW LEVEL SHEAR...SVR STORMS APPEAR UNLIKELY AT THIS TIME. COULD SEE PERIOD OF MDT TO HEAVY RAIN ON THURS...BUT WITH SLOW PROGRESSIVE NATURE OF SYSTEM...APPEARS ANY ONE AREA SHOULD NOT SEE MORE THAN 2 INCHES THROUGH 12Z FRI. AFTER FRONT AND ASSOCD SHORT WAVE PUSH THROUGH...UPPER TROUGH SLOW TO PUSH OUT OF EASTERN CONUS. ANOTHER WAVE IN NW FLOW OVER THE CENTRAL PLAINS PROGGED TO MOVE INTO THE TN VALLEY SAT. QUITE A BIT OF DISCREPANCY BETWEEN MED RANGE MODELS /00Z GFS...ECMWF AND CMC/ ON THIS FEATURE...ECMWF SOMEWHAT SLOWER. WITH DRY AIR MASS EXPECTED AS THIS SECOND WAVE APPROACHES...HAVE BACKED OFF A LITTLE ON POPS. NW FLOW CAN BE TRICKY IN THE WARM SEASON SO WILL NEED TO MONITOR THIS. INSTABILITY PROGGED TO BE LOW BUT NOT ZERO. SNELSON AVIATION... 12Z UPDATE... WIDE RANGE OF LIFR TO VFR CONDITIONS...MAINLY DUE TO FOG..CURRENTLY ACROSS THE FORECAST AREA. MVFR VISIBILITIES PREDOMINATE WITH SCATTERED VFR AND A FEW LOCAL LIFR VISIBILITIES. EXPECT MAINLY VFR CONDITIONS AFTER 14Z OUTSIDE OF ISOLATED TO SCATTERED CONVECTION EXPECTED BETWEEN 18-02Z. SCATTERED CUMULUS DEVELOPMENT AROUND 2-3KFT BY 14 THROUGH 18Z... LIFTING TO 4-5KFT AFTER 18Z. WINDS WILL BE LIGHT..LESS THAN 5KTS...AND SOMEWHAT VARIABLE IN DIRECTION THROUGH 14Z BUT WILL FAVOR SOUTHEAST. WIND SPEEDS WILL INCREASE TO 5-9KTS AFTER 14Z WITH DIRECTION VARYING BETWEEN SOUTHWEST AND SOUTHEAST. //ATL CONFIDENCE...12Z UPDATE... MEDIUM TO HIGH CONFIDENCE ON ALL ELEMENTS. 20 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 89 65 88 64 / 30 20 30 10 ATLANTA 87 68 86 66 / 30 20 30 10 BLAIRSVILLE 84 61 83 62 / 30 20 30 20 CARTERSVILLE 87 63 86 65 / 30 20 30 30 COLUMBUS 91 68 90 67 / 30 20 30 10 GAINESVILLE 85 66 84 65 / 30 20 30 20 MACON 90 65 89 65 / 30 20 30 10 ROME 87 63 86 63 / 30 20 30 30 PEACHTREE CITY 89 64 88 63 / 30 20 30 10 VIDALIA 90 67 89 68 / 30 20 30 5 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...11 LONG TERM....NLISTEMAA AVIATION...11
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
321 PM CDT MON MAY 12 2014 .MESOSCALE DISCUSSION... 150 PM CDT THE OVERALL COVERAGE OF CONVECTION LOOKS TO BE LOW THROUGH MID AFTERNOON. THE MESOSCALE CONVECTIVE SYSTEM /MCS/ THAT TRACKED ACROSS SOUTHERN WISCONSIN EARLIER HAS PLACED AN OUTFLOW BOUNDARY OUT TO ITS SOUTH...WHICH IS LOCATED JUST NORTH OF THE IL/WI STATE LINE. WEAK TO MODERATE CONVERGENCE EXISTS ALONG THIS BOUNDARY THANKS TO THE MODEST SOUTH-SOUTHWEST FLOW WITHIN THE WARM SECTOR. THIS WOULD BE ONE AREA FOR POSSIBLE REDEVELOPMENT WITH STORMS LIKELY MOVING EAST-NORTHEAST IF THEY CAN SPARK. FURTHER TO THE SOUTH...OUTFLOW FROM THE EARLIER MCS ACROSS EASTERN IA HAS PROGRESSED EASTWARD WITH SOME OCCASIONAL MORE AGITATED CU SEEN FROM MORRIS/PERU AREAS SOUTHWESTWARD NEAR PEORIA. OVERALL THOUGH THE CU HAS APPEARED FAIRLY FLAT OVER A LOT OF THE AREA. SO DEVELOPMENT CONFIDENCE ALONG THIS EARLIER OUTFLOW BOUNDARY IS LOW. IT IS LOW CONFIDENCE THAT ANY SEVERE STORMS...AND EVEN POSSIBLY MUCH FOR STORMS ACROSS CHICAGO...WILL DEVELOP OVER A GOOD PORTION OF THE CURRENT WATCH THROUGH 5 PM. WILL CONTINUE THE WATCH LOCALLY HOWEVER BASED ON COLLABORATION WITH SPC AND WFO MKX. CONVECTION IS ALSO POSSIBLE LATE IN THE DAY INTO THE EVE AND AS STORMS IN SEVERE THUNDERSTORM WATCH 150 IN EFFECT IMMEDIATELY TO THE WEST OF THE AREA PROGRESS EAST. THAT COULD POSSIBLY RESULT IN A WATCH SOON AFTER THE CURRENT ONE...NAMELY FOR NORTH CENTRAL ILLINOIS...SO DO NOT WANT TO SEND ANY CONFUSING MESSAGES OF A WATCH CANCELLATION THEN A RE-ISSUANCE. MTF && .DISCUSSION... 244 PM...MULTIPLE FORECAST CONCERNS AND CHALLENGES THROUGH THE PERIOD INCLUDING THUNDERSTORM COVERAGE/TIMING THROUGH TUESDAY AFTERNOON ALONG WITH SEVERE/HEAVY RAIN POTENTIAL. THEN TURNING MUCH COLDER MIDWEEK WITH A PERIOD OF SHOWERS/RAIN FROM WEDNESDAY EVENING INTO THURSDAY. CONVECTIVE TRENDS OVER THE NEXT FEW HOURS DISCUSSED IN THE ABOVE/RECENT MESOSCALE DISCUSSION WITH ATTENTION NOW SHIFTING TO THUNDERSTORMS EXTENDING FROM CENTRAL IOWA SOUTH TO TEXAS...AHEAD OF THE SLOWLY ADVANCING COLD FRONT. SHORT TERM GUIDANCE CONTINUES TO SHOW ADDITIONAL ACTIVITY DEVELOPING AHEAD OF THE CURRENT LINE AS IT ALL SLOWLY SHIFTS EAST...WHICH WOULD BRING ACTIVITY INTO THE WESTERN CWA AS SOON AS 23Z-00Z. SEVERE POTENTIAL WOULD BE HIGHEST EARLIER WITH BETTER INSTABILITY BEFORE LOST OF DAYTIME HEATING...THOUGH TEMPS WILL ONLY SLOWLY DROP THROUGH THE 70S THIS EVENING. AS NOTED IN THE PREVIOUS DISCUSSION...DO ANTICIPATE ANOTHER WATCH LATER THIS EVENING BUT HOW FAR EAST AND COVERAGE OF SEVERE POTENTIAL WILL BE TIED TO TIMING. MAIN THREATS WOULD CONTINUE TO BE LARGE HAIL AND DAMAGING WIND GUSTS. PRECIPITABLE WATER VALUES INCREASE TO 1.5 INCHES AND EVEN A BIT HIGHER TONIGHT AND COMBINED WITH DEWPOINTS IN THE UPPER 60S AND EVEN A FEW LOWER 70S...HEAVY RAIN IS LIKELY. WHILE THE INDIVIDUAL STORMS WILL BE MOVING NORTHEAST FAIRLY QUICKLY...THE ENTIRE FRONTAL PROGRESSION EASTWARD WILL BE RELATIVELY SLOW THUS HEAVY RAIN OVER THE SAME AREAS COULD RESULT IN SOME FLOODING POTENTIAL. AND WITH THE HEAVY RAINS IN PARTS OF THE AREA SUNDAY EVENING...INCLUDING THE SOUTHERN SUBURBS AND NORTHWEST INDIANA...ADDITIONAL HEAVY RAIN COULD LEAD TO LOCALIZED FLASH FLOODING. HOWEVER...CONFIDENCE IS SOMEWHAT LOW WITH THE POTENTIAL FOR CONVECTION TO THE SOUTHWEST TO MOVE EAST SOUTH OF THE AREA AND POTENTIALLY CUT OFF STRONGER/HEAVIER PRECIP ACROSS NORTHERN IL. PRECIP PROGRESSION EASTWARD WILL LIKELY SLOW TUESDAY MORNING AS IT SLOWLY ENDS FROM WEST TO EAST BUT COULD CONTINUE INTO THE AFTERNOON ACROSS NORTHWEST INDIANA. TEMP TRENDS WILL ALSO BE TRICKY AS THEY WILL LIKELY FALL OR BECOME STEADY ACROSS THE EASTERN HALF WITH SOME RECOVERY IN THE WEST IN THE AFTERNOON. TEMPS WILL CONTINUE TO FALL INTO THE MID/UPPER 40S FOR LOWS BY WEDNESDAY MORNING AND WHILE THESE ARE CLOSE TO NORMAL FOR MID MAY...IT WILL LIKELY FEEL MUCH COLDER GIVEN THE CURRENT TEMPS AND DEWPOINTS. AS THE UPPER TROUGH DIGS ACROSS THE CENTRAL AND SOUTHERN PLAINS WEDNESDAY INTO WEDNESDAY NIGHT...NEW LOW PRESSURE WILL DEVELOP OVER THE OHIO VALLEY AND LIFT NORTHEAST ACROSS THE CENTRAL OR EASTERN GREAT LAKES REGION ON THURSDAY. WHILE CONFIDENCE IS INCREASING IN THE OVERALL TRENDS WITH THIS SYSTEM...ITS EXACT TRACK COULD STILL HAVE LARGE IMPACTS ON THE SPECIFICS OF THE FORECAST. FIRST...THERE WILL PROBABLY BE A SHARP PRECIP GRADIENT ON THE NORTHWEST SIDE OF THIS SYSTEM...WHICH WILL LIKELY BE ACROSS THE WESTERN CWA. THE CLOSER THE LOW TRACKS TO THE AREA...THE STRONGER THE NORTHERLY WINDS WILL BE...ESPECIALLY ACROSS THE EASTERN CWA. BUT AS CLOUDS AND SHOWERS SPREAD NORTH WEDNESDAY WITH A RATHER COLD/WET WEDNESDAY NIGHT/THURSDAY MORNING. HIGHS WEDNESDAY AND THURSDAY LIKELY ONLY IN THE 50S...THOUGH ANY SUNSHINE ESPECIALLY WESTERN AREAS COULD PUSH TEMPS INTO THE 60S. AS AN UPPER LOW DEVELOPS ACROSS THE NORTHERN LAKES REGION THURSDAY AND SLOWLY DRIFTS EAST THIS WEEKEND...WEAK IMPULSES COULD HELP TRIGGER AFTERNOON SHOWERS ON FRIDAY AND PERHAPS AGAIN ON SATURDAY THOUGH COVERAGE SHOULD BE MAINLY ISOLATED. TEMPERATURES WILL START A SLOW WARMING TREND THROUGH THE 60S THIS WEEKEND AND PERHAPS BACK INTO THE 70S EARLY NEXT WEEK. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * SSWLY TO SWLY WINDS TO 25KT THIS AFTERNOON AND EVENING OUTSIDE OF THUNDERSTORMS. * TIMING AND CHANCES OF ADDITIONAL TSRA THIS AFTERNOON AND TONIGHT. * OCNL MVFR CIGS THIS AFTERNOON AND TONIGHT. KREIN //DISCUSSION...UPDATED 18Z... MAIN CONCERN CONTINUES TO BE THE CHANCES FOR THUNDERSTORMS THIS AFTERNOON AND TONIGHT...UNTIL A COLD FRONTAL PASSAGE TOMORROW MORNING. THE ENVIRONMENT OVER THE AREA IS WARM AND MOIST WITH TEMPERATURES IN THE 80S AND DEWPOINTS IN UPPER 60S. OLD OUTFLOW BOUNDARIES FROM EARLIER CONVECTIVE ACTIVITY CAN PROVIDE THE FOCUS FOR ADDITIONAL THUNDERSTORM DEVELOPMENT...BUT TIMING IS VERY UNCERTAIN AND RESIDUAL CLOUD COVER MAY BE A LIMITING FACTOR FOR THE NEXT FEW HOURS AS BOTH CI AND LOWER STRATOCU ARE FILTERING TH SUNSHINE. ANTICIPATE THAT CLOUD COVER SHOULD THIN WITH TIME AND IS THE TREND IN THE LATEST SATELLITE IMAGERY...SO THERE WILL BE A CHANCE FOR SCATTERED THUNDERSTORM DEVELOPMENT THROUGH THE AFTERNOON AND EVENING. GIVEN THE TIMING AND COVERAGE UNCERTAINTIES...HAVE BACK OFF TO JUST VCTS MENTION...UNTIL A MORE ORGANIZED FOCUSING MECHANISM BECOMES APPARENT. HAVE MAINTAINED THE PROB30 MENTION FOR THUNDER FOR THE LATE NIGHT TO EARLY MORNING HOURS...IN CONJUNCTION WITH THE APPROACHING COLD FRONT. EXPECT THAT WINDS SHOULD SHIFT TO WESTERLY FOLLOWING THE FROPA...WHILE REMAINING RELATIVELY BRISK AND GUSTY. KREIN //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM TO HIGH CONFIDENCE IN WIND FORECAST. * MEDIUM CONFIDENCE IN CEILING TRENDS. * LOW CONFIDENCE CONVECTIVE TIMING AND COVERAGE TODAY AND TONIGHT. * MEDIUM TO HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... * TUESDAY NIGHT...VFR. * WEDNESDAY...SLIGHT CHANCE OF PM SHRA. * THURSDAY...CHANCE OF SHRA. * FRIDAY...SLIGHT CHANCE OF SHRA. * SATURDAY AND SUNDAY...DRY/VFR. KJB && .MARINE... 320 PM CDT AREAS OF DENSE FOG CONTINUE TO PERSIST LATE THIS AFTERNOON ACROSS NORTHERN LAKE MICHIGAN PER SHIP OBS AND SURROUNDING SFC COASTAL OBS NORTH OF THE WARM FRONT DRAPED WEST TO EAST ACROSS THE MIDDLE PART OF THE LAKE. THIS WARM FRONT EXTENDS BACK WEST TO LOW PRESSURE OVER E CENTRAL MN / NORTHWEST WI WHICH WILL CONTINUE TO MOVE NORTHEAST TONIGHT. THIS FRONTAL BOUNDARY WILL CONTINUE TO BE A FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT TONIGHT AS WELL. A COLD FRONT ASSOCIATED WITH THE LOW WILL SWEEP WEST TO EAST ACROSS THE LAKE AROUND DAYBREAK TUESDAY SWEEPING OUT THE FOG AND BRINGING ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE MORNING TUESDAY. WINDS OCCASIONALLY EXCEEDING SMALL CRAFT ADVISORY THRESHOLDS WILL CONTINUE INTO THIS EVENING ALONG THE ILLINOIS AND INDIANA SHORELINES. ONGOING CONVECTION HAS DISRUPTED THE WIND FIELD CAUSING AN ONSHORE LAKE BREEZE ESPECIALLY FARTHER NORTH CLOSER TO THE OUTFLOW FROM EARLIER THUNDERSTORMS ACROSS WISCONSIN AND CENTRAL LAKE MICHIGAN. AS THE SOUTHERLY GRADIENT REESTABLISHES ITSELF... NEW SCATTERED THUNDERSTORMS MAY ALSO CAUSE HIGHER WINDS AND WAVES INTO THE EVENING THROUGHOUT THE NEAR SHORE WATERS. ED F && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM MONDAY. DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565 UNTIL 1 AM TUESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 254 PM CDT Mon May 12 2014 .DISCUSSION... ISSUED 252 PM CDT Mon May 12 2014 Warm and rather humid day across the forecast area today, with dew points in the upper 60s to around 70 degrees and temperatures mostly in the 80s. Air mass over our area is uncapped and CAPE`s are from 3500-4000 J/kg in central Illinois, but so far convection in our CWA has been spotty. More widespread showers/storms have been occurring across the Ohio Valley. Main action has been filling in across Iowa and the northwest half of Missouri, along a cold front. SHORT TERM...Tonight through Thursday: Initial forecast concern is on the severe weather potential the next several hours. The individual storms to our west have been moving northeast with the overall area only slowly shifting eastward. The HRRR and NMM high-resolution models have that particular band of storms reaching the Illinois River around 6 to 7 pm and the I-55 corridor around 9 to 10 pm. Surface observations over the area are not showing any meaningful boundary currently present, thus the popcorn nature of the showers/storms so far. Infrared and water vapor imagery showing some anti-cyclonic motion over our CWA, which could be causing enough sinking of the air to keep the showers under control so far. 0-6km shear values expected to remain rather modest in most areas, so am thinking that the storms will remain rather disorganized but briefly severe until the main line gets here. Loss of daytime heating should weaken the line of storms somewhat as it moves through tonight, but CAPE`s remain 1000-2000 J/kg ahead of the front so there will still be some instability to work with. Morning model runs have the front roughly along the Indiana border by midday, with threat of thunder diminishing from west to east through the day. Have kept the dry weather west of I-55 for the afternoon with likely PoP`s across east central and southeast Illinois continuing in the afternoon. Temperatures across the east will be slowly falling in the afternoon behind the front. Long-advertised phasing of upper troughs in the north central and southwest U.S. will try to take place the next couple days, although the models keep them somewhat distinct through mid week. Development of a surface low will take place Tuesday night across the lower Mississippi Valley, and this low will be ejected northeast on the nose of a developing 90-110 knot jet. Dry northeast flow will erode the northern fringes of the rain shield some, so will continue to focus the higher PoP`s on Wednesday across the southeast half of the forecast area. As the surface low moves northeast, a large upper low will develop over the upper Mississippi Valley, so the threat of showers will continue even after the main precipitation shield exits. High temperatures both Wednesday and Thursday only expected to be in the upper 50s to around 60 most areas due to the cooler air aloft and the rain. LONG TERM...Friday through Monday: The cool and showery weather will continue into Friday, before the upper low starts to lift into Ontario and the upper pattern over the U.S. flattens out somewhat. A fast moving wave in the upper flow tracks an area of rain southeast later in the weekend, with the ECMWF model about 12-18 hours faster and a bit further north. Have limited PoP`s on Saturday night and Sunday to slight chances across the south half of the forecast area, but this may need to be bumped up if these trends persist on the next couple model runs. A more substantial warming trend will occur early next week, as ridging occurs across the Plains. Geelhart && .AVIATION... ISSUED 1253 PM CDT Mon May 12 2014 Main aviation concern during the 18z TAF period will be timing of potential convection later this afternoon into tonight. Model solutions are all over the place concerning convective initiation: however, best forcing associated with cold front and other mesoscale boundaries appears that it will stay west of the central Illinois terminals until evening. HRRR tries to develop scattered showers/storms west of I-55 between 20z and 23z, while NAM continues to focus mainly on the evening hours. Will include VCTS at all TAF sites from mid-afternoon on, but will not mention predominant thunder until later. Based on NAM solution, will include TSRA between 00z and 04z at KPIA, then further east to KCMI between 05z and 09z. Once initial line of storms passes, a period of light rain will likely linger along and just behind the cold front overnight into early Tuesday morning. Forecast soundings suggest MVFR ceilings with this precip. Winds will initially be from the S/SW this afternoon, gusting to between 20 and 25kt at times. S/SW winds will continue through the evening before veering to the W/NW after FROPA overnight. Winds will shift to the W/NW at KPIA by 09z, then further east to KCMI by 15z. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1256 PM CDT MON MAY 12 2014 .DISCUSSION... 1056 AM CDT A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR FAR NORTHERN ILLINOIS UNTIL 5 PM THAT COVERS BASICALLY THE INTERSTATE 88 CORRIDOR AND NORTHWARD. THIS INCLUDES ROCKFORD AND THE CITY OF CHICAGO. THE REALLY CHALLENGING FORECAST OF CONVECTIVE EVOLUTION CONTINUES WITH A COUPLE REGIONAL COMPLEXES OF STORMS PROPAGATING EASTWARD AT THE LEADING EDGE OF THE WARM AND MOIST LOW-LEVEL AIR. THE NORTHERN ONE ACROSS SOUTHERN WI IS THE MORE ROBUST ONE AND FEEDING ON BETTER UPPER AND MID-LEVEL SUPPORT. THE STORMS NEAR THE QUAD CITIES HAVE SHOWN A GENERAL WEAKENING TREND. THE ORIENTATION OF DEEP LAYER SHEAR VECTORS TO THESE COMPLEXES DO NOT INDICATE A RAPID WIND THREAT DEVELOPING FROM THESE...HOWEVER THE OVERALL CAPE/SHEAR SPECTRUM IS POTENTIALLY FAVORING SCATTERED SEVERE STORMS TO DEVELOP THROUGH THE AFTERNOON. THE 12Z RAOBS AT DVN AND ILX SOUNDING MODIFIED FOR FORECAST EARLY AFTERNOON TEMPERATURES INDICATED INSTABILITY IN EXCESS OF 2000 J/KG IN THE MIXED LAYER...AND POTENTIALLY TOPPING 3500 J/KG. AS THINNING OF HIGH CLOUDS CONTINUES OVER THE FORECAST AREA...THIS HIGH DEGREE OF DESTABILIZATION SHOULD BE REALIZED. WHILE EXACT EVOLUTION OF THESE COMPLEXES AS IT RELATES TO OUR FORECAST AREA IS UNCERTAIN...AT LEAST SCATTERED CONVECTIVE DEVELOPMENT IS BELIEVED TO BE PROBABLE FROM SURFACE AND/OR ELEVATED OUTFLOW BOUNDARIES OVER FAR NORTHERN ILLINOIS. CONVECTIVE ALLOWING MODELS CERTAINLY VARY IN THEIR SOLUTIONS...BUT GENERALLY HAVE BEEN TRENDING WITH MORE AFTERNOON CONVECTION ACROSS NORTHERN ILLINOIS. SO IT WAS THOUGHT BEST TO INCLUDE FAR NORTHERN ILLINOIS IN THIS SEVERE THUNDERSTORM WATCH THROUGH THIS AFTERNOON. THE PRIMARY HAZARDS WOULD BE WINDS AND LARGE HAIL...WITH MULTI- CELL CLUSTERS THE FAVORED MODE. MTF //PREV DISCUSSION... 328 AM CDT AMONG THIS MORNING`S MANY RECAST CHALLENGES ARE TEMPS TODAY...PRECIP AND CONVECTIVE TRENDS THROUGH TONIGHT...RAIN CHANCES LATER IN THE WEEK WITH SECONDARY CYCLONE...AND MAGNITUDE OF COLD AIR MASS LATER THIS WEEK. IT IS FUNNY HOW OFTEN CONFIDENCE IN A FORECAST DECREASES AS THE FORECAST TIME NEARS. LAST NIGHT AT THIS TIME WAS FAIRLY CONFIDENT THAT CONVECTION TO OUR WEST WOULD DISSIPATE BEFORE MAKING IT INTO OUR AREA WITH THE FOCUS SHIFTING NORTH INTO WISCONSIN...BUT PLAYING A GAME OF METEOROLOGICAL CHICKEN WITH THE MCS OVER IOWA THAT CONTINUES TO CHARGE EAST TOWARD THE MISSISSIPPI RIVER EARLY THIS MORNING AND AM GROWING INCREASINGLY TEMPTED TO FLINCH AND BUMP UP POPS SOME THIS MORNING. THE ATMOSPHERE OVER NORTHERN ILLINOIS WAS SIGNIFICANTLY MODIFIED AND STABILIZED BY SUNDAY EVENING`S CONVECTION...BUT CONTRASTING THE 00Z SOUNDINGS FROM DVN AND ILX SHOW JUST HOW NEARBY THE CONVECTIVELY MOIST AND UNSTABLE AIR MASS LIES. THE COMPOSITE SECONDARY WARM FRONT/OUTFLOW BOUNDARY EXTENDING ROUGHLY FROM KLAF TO JUST SOUTH OF THE QUAD CITIES IS LIFTING NORTH AND/OR WASHING OUT WITH WINDS ACROSS NORTHERN ILLINOIS VEERING MORE SOUTHERLY AND HIGHER DEWPOINTS CREEPING NORTHWARD. SHORT RANGE GUIDANCE IS STRONGLY DIVIDED IN THE HANDLING OF THE MCS OVER IOWA...WITH ONE CAMP SHOWING A FAIRLY RAPID DEMISE OVER THE NEXT SEVERAL HOURS WITH ONLY SCTD SHRA/ISOLD TSRA POTENTIALLY MAKING IT INTO NW CWA WHILE ANOTHER CAMP OF MODELS IS MORE AGGRESSIVE IN BRINGING STORMS EAST ACROSS THE CWA THROUGH THE MORNING. THE IMPLICATIONS OF HOW THIS SCENARIO EVOLVES ARE HUGE FOR TEMPS...WINDS...AND SUBSEQUENT CONVECTIVE CHANCES WITH THE COLD FRONT. CONFIDENCE IS NOT HIGH...BUT LEANING TOWARD STAYING THE COURSE WITH THINKING FROM PREVIOUS FORECASTS WHICH SUGGEST A QUICK WEAKENING TREND WITHOUT MUCH CONVECTION MAKING IT FAR INTO OUR CWA. RECENT REGIONAL RADAR AND SATELLITE TRENDS SEEM TO FINALLY BE SUPPORTING THIS LINE OF THINKING WITH CLOUD TOPS BEGINNING TO QUICKLY WARM WITH DECREASING COVERAGE AND INTENSITY OF THE STORMS. SEVERAL MODELS ARE HINTING AT THE POTENTIAL FOR ADDITIONAL SCTD CONVECTION DEVELOPING IN THE WARM/MOIST/UNSTABLE AXIS EXTENDING FROM DOWNSTATE IL NNE INTO NNW INDIANA. DESPITE LEANING TOWARD THE DRIER SOLUTIONS FOR TODAY WILL BE MAINTAINING CHANCE POPS ACROSS THE CWA TO ALLOW FOR EITHER THE IOWA MCS PERSISTING LONGER AND/OR MOIST/UNSTABLE AXIS THIS AFTERNOON. HIGH TEMPS AND EVEN GUSTINESS OF THE WINDS TODAY WILL HINGE ON CLOUD COVER AND PRECIP. IF THE MCS CONTINUES TO QUICKLY WEAKEN AND DEBRIS CLOUDINESS DISSIPATE...THEN IT SHOULD ALLOW FOR PARTIAL SUNSHINE AND WHICH COULD SEND TIMES CLIMBING WELL INTO THE 80S AND ABOVE OBJECTIVE GUIDANCE. THIS IS THE CURRENT FORECAST AND RATHER THAN FLIP ONLY TO HAVE THE DAY SHIFT HAVE TO FLOP WILL STAY THE COURSE WITH ABOVE GUIDANCE HIGHS AND IF IT BECOMES CLEAR THAT CLOUDS WILL STICK AROUND THE DAY SHIFT CAN BACK OFF ON TEMPS WITH A MORNING UPDATE. THERE ARE A HANDFUL OF CONVECTIVE ALLOWING MODELS SHOWING A RELATIVE MIN IN CONVECTIVE REDEVELOPMENT OVER IOWA TONIGHT FOLLOWING THE STABILIZING EFFECTS OF CURRENT MCS...BUT WITH GREATER NUMBER OF MODELS SUPPORTING RE-DEVELOPMENT PLAN TO HANG ON TO LIKELY POPS TONIGHT AS THE FRONT MOVES EAST TOWARD THE AREA. MORE MARGINAL AND UNIDIRECTIONAL SHEAR PROFILES AND DECREASING INSTABILITY AT NIGHT BOTH WOULD ARGUE FOR STORMS MOVING INTO THE AREA TONIGHT TO BE IN A WEAKENING PHASE WITH SEVERE THREAT DECREASING WITH TIME AND EASTWARD EXTENT TONIGHT. RAIN COULD LINGER INTO TUESDAY...ESPECIALLY IN THE MORNING AND OVER THE EASTERN CWA BEFORE BETTER FORCING PUSHES OFF TO THE EAST AND DRIER AIR MOVES IN. TUESDAY AFTERNOON COULD BE SALVAGEABLE FOR MANY AREAS WITH NEAR NORMAL HIGHS AND LIKELY AN END TO THE PRECIPITATION. LATER WEDNESDAY INTO THURSDAY GUIDANCE REALLY RUNS THE GAMUT IN HANDLING OF THE SECONDARY SHORTWAVE TROUGH ROUNDING THE BASE OF THE DEEP UPPER TROUGH THAT WILL BECOME ESTABLISHED OVER EASTERN NOAM. WPC PREFERRED MODEL CHOICE WAS THE 00Z ECMWF WHICH IS CLOSE TO THE MIDDLE OF THE ROAD OF POSSIBLE SOLUTIONS AND SAW NO REASON TO DEVIATE FROM THIS LINE OF THINKING. ASSUMING THE ECMWF VERIFIES A SECONDARY WAVE OF LOW PRESSURE WILL TRACK NORTHEAST ALONG THE PASSING COLD FRONT AND PRODUCE A PERIOD OF RAIN/SHOWERS...MAINLY SOUTHEASTERN HALF OF THE CWA. REMARKABLY SOME GUIDANCE HAS 850MB TEMPS DROPPING TO 0 TO -2C DURING THE PRECIP WHICH WHILE COLD IS PROBABLY NOT COLD ENOUGH FOR ANY MIXED PRECIP GIVEN THE TIME YEAR BUT PERILOUSLY CLOSE. GIVEN THE MODEL SPREAD EARLY IN THE PERIOD PROBABLY NOT SURPRISING THAT THERE IS SUBSTANTIAL SPREAD IN THE INTENSITY OF THE UPPER TROUGH/LOW LATE IN THE WEEK AND SUBSEQUENT TEMPS WITH FAR MORE AMPLIFIED AND COLD SOLUTION IN THE ECMWF SUPPORTIVE OF TEMPS COLDER THAN WHAT OUR CURRENT FORECAST BUT WITH SO MUCH UNCERTAINTY SO NO REASON TO STRAY FROM THE BLENDED MODEL CONSENSUS. IZZI && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * SSWLY TO SWLY WINDS TO 25KT THIS AFTERNOON AND EVENING OUTSIDE OF THUNDERSTORMS. * TIMING AND CHANCES OF ADDITIONAL TSRA THIS AFTERNOON TONIGHT. * OCNL MVFR CIGS THIS AFTERNOON AND TONIGHT. KREIN //DISCUSSION...UPDATED 18Z... MAIN CONCERN CONTINUES TO BE THE CHANCES FOR THUNDERSTORMS THIS AFTERNOON AND TONIGHT...UNTIL A COLD FRONTAL PASSAGE TOMORROW MORNING. THE ENVIRONMENT OVER THE AREA IS WARM AND MOIST WITH TEMPERATURES IN THE 80S AND DEWPOINTS IN UPPER 60S. OLD OUTFLOW BOUNDARIES FROM EARLIER CONVECTIVE ACTIVITY CAN PROVIDE THE FOCUS FOR ADDITIONAL THUNDERSTORM DEVELOPMENT...BUT TIMING IS VERY UNCERTAIN AND RESIDUAL CLOUD COVER MAY BE A LIMITING FACTOR FOR THE NEXT FEW HOURS AS BOTH CI AND LOWER STRATOCU ARE FILTERING TH SUNSHINE. ANTICIPATE THAT CLOUD COVER SHOULD THIN WITH TIME AND IS THE TREND IN THE LATEST SATELLITE IMAGERY...SO THERE WILL BE A CHANCE FOR SCATTERED THUNDERSTORM DEVELOPMENT THROUGH THE AFTERNOON AND EVENING. GIVEN THE TIMING AND COVERAGE UNCERTAINTIES...HAVE BACK OFF TO JUST VCTS MENTION...UNTIL A MORE ORGANIZED FOCUSING MECHANISM BECOMES APPARENT. HAVE MAINTAINED THE PROB30 MENTION FOR THUNDER FOR THE LATE NIGHT TO EARLY MORNING HOURS...IN CONJUNCTION WITH THE APPROACHING COLD FRONT. EXPECT THAT WINDS SHOULD SHIFT TO WESTERLY FOLLOWING THE FROPA...WHILE REMAINING RELATIVELY BRISK AND GUSTY. KREIN //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM TO HIGH CONFIDENCE IN WIND FORECAST. * MEDIUM CONFIDENCE IN CEILING TRENDS. * LOW CONFIDENCE CONVECTIVE TIMING AND COVERAGE TODAY AND TONIGHT. * MEDIUM TO HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... * TUESDAY NIGHT...VFR. * WEDNESDAY...SLIGHT CHANCE OF PM SHRA. * THURSDAY...CHANCE OF SHRA. * FRIDAY...SLIGHT CHANCE OF SHRA. * SATURDAY AND SUNDAY...DRY/VFR. KJB && .MARINE... 323 AM CDT AN AREA OF LOW PRESSURE ACROSS THE MID MISSOURI VALLEY EARLY THIS MORNING WILL TRACK NORTHEASTWARD TOWARDS LAKE SUPERIOR BY TONIGHT. AS THIS OCCURS...AN ASSOCIATED WARM FRONT IS EXPECTED TO LIFT NORTHWARD UP THE LAKE THROUGH TONIGHT. AREAS OF FOG...POTENTIALLY DENSE WILL BE LIKELY ACROSS PORTIONS OF THE LAKE TODAY AND TONIGHT AS THIS FRONT...AND THE ACCOMPANYING VERY MOIST AIR MASS MOVES OVER THE COOL LAKE WATERS. A MARINE DENSE FOG ADVISORY MAY BE NEEDED. THE OTHER CONCERN WILL BE THE WINDS TODAY AND TONIGHT WITH THIS WARM FRONT LIFTING UP THE LAKE. THE WINDS SOUTH OF THIS WARM FRONT WILL BECOME SOUTHERLY AROUND 25 KT TODAY...WHILE NORTH OF THE WARM FRONT...SOME STOUT EASTERLY WINDS WILL BE LIKELY. THESE GUSTY SOUTHERLY WINDS WILL RESULT IN LIKELY RESULT IN NEAR SMALL CRAFT ADVISORY WINDS OVER THE ILLINOIS AND INDIANA NEAR SHORE WATERS BY MIDDAY. HOWEVER...IN SPITE OF THIS...I HAVE OPTED TO HOLD OFF ON AN ADVISORY DUE TO THERE BEING SOME QUESTION AS TO EXACTLY HOW STRONG THE WINDS WILL BE OVER THE NEAR SHORE WATERS. IN ADDITION...WITH THE OFFSHORE COMPONENT...WAVES WILL LIKELY NOT BUILD OVER 4 FT IN THE NEAR SHORE WATERS. THE POTENTIAL IS CERTAINLY THERE FOR 25+ KT OFFSHORE FLOW TODAY...WITH THE POTENTIAL NEED FOR AN UPGRADE TO A SMALL CRAFT ADVISORY. KJB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM MONDAY. DENSE FOG ADVISORY...LMZ567-LMZ669-LMZ671-LMZ868-LMZ870-LMZ872 UNTIL 3 PM MONDAY. DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565 UNTIL 1 AM TUESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1253 PM CDT Mon May 12 2014 .DISCUSSION... ISSUED 949 AM CDT Mon May 12 2014 Another warm and humid day is unfolding across central Illinois, as 14z/9am temps have already risen well into the 70s. The area remains convection-free for the time being, but as weak capping is broken over the next couple of hours widely scattered thunderstorms will begin to develop. Enhanced Cu field is currently evident on visible satellite imagery from Arkansas northeastward across the eastern half of the KILX CWA. Latest mesoanalysis from SPC indicates deep layer moisture convergence maximized from southeast Missouri into southeast Illinois, where HRRR shows scattered thunderstorm development between now and 18z. Elsewhere around central Illinois, convection will likely remain more isolated in nature until later this afternoon when cold front begins to approach from the west. Front is still progged to reach the area after dark tonight, so best chances for widespread convection will likely hold off until late afternoon/early evening in the Illinois River Valley, then further east across the remainder of the area overnight. Barnes && .AVIATION... ISSUED 1253 PM CDT Mon May 12 2014 Main aviation concern during the 18z TAF period will be timing of potential convection later this afternoon into tonight. Model solutions are all over the place concerning convective initiation: however, best forcing associated with cold front and other mesoscale boundaries appears that it will stay west of the central Illinois terminals until evening. HRRR tries to develop scattered showers/storms west of I-55 between 20z and 23z, while NAM continues to focus mainly on the evening hours. Will include VCTS at all TAF sites from mid-afternoon on, but will not mention predominant thunder until later. Based on NAM solution, will include TSRA between 00z and 04z at KPIA, then further east to KCMI between 05z and 09z. Once initial line of storms passes, a period of light rain will likely linger along and just behind the cold front overnight into early Tuesday morning. Forecast soundings suggest MVFR ceilings with this precip. Winds will initially be from the S/SW this afternoon, gusting to between 20 and 25kt at times. S/SW winds will continue through the evening before veering to the W/NW after FROPA overnight. Winds will shift to the W/NW at KPIA by 09z, then further east to KCMI by 15z. Barnes && .PREV DISCUSSION... ISSUED 330 AM CDT Mon May 12 2014 SHORT TERM...Today through Wednesday night Quiet conditions temporarily returned to central and southeast IL early this morning as convection with MCS had shifted east of IL into east central IN and Ohio, and a larger area of convection with a couple MCSS was over WI/IA and eastern KS into far nw MO. Cold front over western IA and eastern KS into central OK and west Texas while warm front was over northern IL. Moist dewpoints in the upper 60s over central and southern IL and mild temps 69-75F with sse winds in warm sector. Strong upper level trof over the Rockies with 557 dm 500 mb low over western CO to eject surface 1002 mb low over east central KS ne into the upper MS river valley by midnight tonight and swing a cold front east across IL overnight. 00Z models are in fair agreement with timing of this cold frontal passage. Isolated to scattered thunderstorms to develop during today especially this afternoon over the IL river valley as air mass destabilizes with CAPES increasing to 1500-2500 J/kg. Best chances of convection will be tonight with slight chance of severe storms nw of IL river this evening. Best risk of severe supercells with possible tornados form mid afternoon into mid evening will be over eastern IA northern MO into far nw IL and sw WI where stronger wind shear will be. Another very warm and humid day with highs in the mid 80s with a few areas se of IL river even seeing upper 80s with enough sunshine. Cold front to pass east into Indiana early Tue morning and have highest chances of convection over eastern IL Tue morning and diminishing to the west. SPC has 5% risk of severe storms Tue from Wabash river east so mostly over IN. Highs Tue range from mid 60s from I-55 west to the low to mid 70s east of I-57 in eastern IL. Looks like a lull in shower chances over central IL Tue night though kept chances of showers over southern areas especially se IL closer to frontal boundary stalling just se of IL. Leaned on wetter ECMWF and NAM models with surface low ejecting ne Wed and passing just se of IL while GFS appears too weak and far to the east with its QPF fields. Have isolated thunderstorms Wed se of I-70 while SPC keeps slight risk of severe storms se of IL Wed. Showers to diminish from the west during Wed night with highest chances near the IN border Wed evening. Cooler highs in the upper 50s and lower 60s Wed and these cooler readings to linger Thu. LONG TERM...Thursday through Monday Medium to long range models and their ensembles continues to advertise large upper level trof over the MS river valley Thu and upper level low lifting north of the Great Lakes this weekend while trof shifts east into the eastern states. As core of coolest 850 mb air shifts ne of central IL during the weekend with upper level low, expect temperatures to modify during this weekend into early next week but generally still stay a below normal. Cool nights in the low to mid 40s Thu night through Sat night. Instability light rain showers possible Thu & Fri especially during the afternoon and early evening with disturbances pivoting thru the nearby upper level trof. Isolated light showers still possible Sat sw of I-74 while dry conditions then prevail from Sat night through Monday. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1052 AM CDT MON MAY 12 2014 .DISCUSSION... 328 AM CDT AMONG THIS MORNING`S MANY RECAST CHALLENGES ARE TEMPS TODAY...PRECIP AND CONVECTIVE TRENDS THROUGH TONIGHT...RAIN CHANCES LATER IN THE WEEK WITH SECONDARY CYCLONE...AND MAGNITUDE OF COLD AIR MASS LATER THIS WEEK. IT IS FUNNY HOW OFTEN CONFIDENCE IN A FORECAST DECREASES AS THE FORECAST TIME NEARS. LAST NIGHT AT THIS TIME WAS FAIRLY CONFIDENT THAT CONVECTION TO OUR WEST WOULD DISSIPATE BEFORE MAKING IT INTO OUR AREA WITH THE FOCUS SHIFTING NORTH INTO WISCONSIN...BUT PLAYING A GAME OF METEOROLOGICAL CHICKEN WITH THE MCS OVER IOWA THAT CONTINUES TO CHARGE EAST TOWARD THE MISSISSIPPI RIVER EARLY THIS MORNING AND AM GROWING INCREASINGLY TEMPTED TO FLINCH AND BUMP UP POPS SOME THIS MORNING. THE ATMOSPHERE OVER NORTHERN ILLINOIS WAS SIGNIFICANTLY MODIFIED AND STABILIZED BY SUNDAY EVENING`S CONVECTION...BUT CONTRASTING THE 00Z SOUNDINGS FROM DVN AND ILX SHOW JUST HOW NEARBY THE CONVECTIVELY MOIST AND UNSTABLE AIR MASS LIES. THE COMPOSITE SECONDARY WARM FRONT/OUTFLOW BOUNDARY EXTENDING ROUGHLY FROM KLAF TO JUST SOUTH OF THE QUAD CITIES IS LIFTING NORTH AND/OR WASHING OUT WITH WINDS ACROSS NORTHERN ILLINOIS VEERING MORE SOUTHERLY AND HIGHER DEWPOINTS CREEPING NORTHWARD. SHORT RANGE GUIDANCE IS STRONGLY DIVIDED IN THE HANDLING OF THE MCS OVER IOWA...WITH ONE CAMP SHOWING A FAIRLY RAPID DEMISE OVER THE NEXT SEVERAL HOURS WITH ONLY SCTD SHRA/ISOLD TSRA POTENTIALLY MAKING IT INTO NW CWA WHILE ANOTHER CAMP OF MODELS IS MORE AGGRESSIVE IN BRINGING STORMS EAST ACROSS THE CWA THROUGH THE MORNING. THE IMPLICATIONS OF HOW THIS SCENARIO EVOLVES ARE HUGE FOR TEMPS...WINDS...AND SUBSEQUENT CONVECTIVE CHANCES WITH THE COLD FRONT. CONFIDENCE IS NOT HIGH...BUT LEANING TOWARD STAYING THE COURSE WITH THINKING FROM PREVIOUS FORECASTS WHICH SUGGEST A QUICK WEAKENING TREND WITHOUT MUCH CONVECTION MAKING IT FAR INTO OUR CWA. RECENT REGIONAL RADAR AND SATELLITE TRENDS SEEM TO FINALLY BE SUPPORTING THIS LINE OF THINKING WITH CLOUD TOPS BEGINNING TO QUICKLY WARM WITH DECREASING COVERAGE AND INTENSITY OF THE STORMS. SEVERAL MODELS ARE HINTING AT THE POTENTIAL FOR ADDITIONAL SCTD CONVECTION DEVELOPING IN THE WARM/MOIST/UNSTABLE AXIS EXTENDING FROM DOWNSTATE IL NNE INTO NNW INDIANA. DESPITE LEANING TOWARD THE DRIER SOLUTIONS FOR TODAY WILL BE MAINTAINING CHANCE POPS ACROSS THE CWA TO ALLOW FOR EITHER THE IOWA MCS PERSISTING LONGER AND/OR MOIST/UNSTABLE AXIS THIS AFTERNOON. HIGH TEMPS AND EVEN GUSTINESS OF THE WINDS TODAY WILL HINGE ON CLOUD COVER AND PRECIP. IF THE MCS CONTINUES TO QUICKLY WEAKEN AND DEBRIS CLOUDINESS DISSIPATE...THEN IT SHOULD ALLOW FOR PARTIAL SUNSHINE AND WHICH COULD SEND TIMES CLIMBING WELL INTO THE 80S AND ABOVE OBJECTIVE GUIDANCE. THIS IS THE CURRENT FORECAST AND RATHER THAN FLIP ONLY TO HAVE THE DAY SHIFT HAVE TO FLOP WILL STAY THE COURSE WITH ABOVE GUIDANCE HIGHS AND IF IT BECOMES CLEAR THAT CLOUDS WILL STICK AROUND THE DAY SHIFT CAN BACK OFF ON TEMPS WITH A MORNING UPDATE. THERE ARE A HANDFUL OF CONVECTIVE ALLOWING MODELS SHOWING A RELATIVE MIN IN CONVECTIVE REDEVELOPMENT OVER IOWA TONIGHT FOLLOWING THE STABILIZING EFFECTS OF CURRENT MCS...BUT WITH GREATER NUMBER OF MODELS SUPPORTING RE-DEVELOPMENT PLAN TO HANG ON TO LIKELY POPS TONIGHT AS THE FRONT MOVES EAST TOWARD THE AREA. MORE MARGINAL AND UNIDIRECTIONAL SHEAR PROFILES AND DECREASING INSTABILITY AT NIGHT BOTH WOULD ARGUE FOR STORMS MOVING INTO THE AREA TONIGHT TO BE IN A WEAKENING PHASE WITH SEVERE THREAT DECREASING WITH TIME AND EASTWARD EXTENT TONIGHT. RAIN COULD LINGER INTO TUESDAY...ESPECIALLY IN THE MORNING AND OVER THE EASTERN CWA BEFORE BETTER FORCING PUSHES OFF TO THE EAST AND DRIER AIR MOVES IN. TUESDAY AFTERNOON COULD BE SALVAGEABLE FOR MANY AREAS WITH NEAR NORMAL HIGHS AND LIKELY AN END TO THE PRECIPITATION. LATER WEDNESDAY INTO THURSDAY GUIDANCE REALLY RUNS THE GAMUT IN HANDLING OF THE SECONDARY SHORTWAVE TROUGH ROUNDING THE BASE OF THE DEEP UPPER TROUGH THAT WILL BECOME ESTABLISHED OVER EASTERN NOAM. WPC PREFERRED MODEL CHOICE WAS THE 00Z ECMWF WHICH IS CLOSE TO THE MIDDLE OF THE ROAD OF POSSIBLE SOLUTIONS AND SAW NO REASON TO DEVIATE FROM THIS LINE OF THINKING. ASSUMING THE ECMWF VERIFIES A SECONDARY WAVE OF LOW PRESSURE WILL TRACK NORTHEAST ALONG THE PASSING COLD FRONT AND PRODUCE A PERIOD OF RAIN/SHOWERS...MAINLY SOUTHEASTERN HALF OF THE CWA. REMARKABLY SOME GUIDANCE HAS 850MB TEMPS DROPPING TO 0 TO -2C DURING THE PRECIP WHICH WHILE COLD IS PROBABLY NOT COLD ENOUGH FOR ANY MIXED PRECIP GIVEN THE TIME YEAR BUT PERILOUSLY CLOSE. GIVEN THE MODEL SPREAD EARLY IN THE PERIOD PROBABLY NOT SURPRISING THAT THERE IS SUBSTANTIAL SPREAD IN THE INTENSITY OF THE UPPER TROUGH/LOW LATE IN THE WEEK AND SUBSEQUENT TEMPS WITH FAR MORE AMPLIFIED AND COLD SOLUTION IN THE ECMWF SUPPORTIVE OF TEMPS COLDER THAN WHAT OUR CURRENT FORECAST BUT WITH SO MUCH UNCERTAINTY SO NO REASON TO STRAY FROM THE BLENDED MODEL CONSENSUS. IZZI && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * GUSTY SOUTHERLY TO SOUTH-SOUTHWESTERLY WINDS TODAY. * TIMING AND CHANCES OF ADDITIONAL TSRA TODAY AND TONIGHT. * LOWER MVFR CIGS POSS TUESDAY MORNING. KREIN //DISCUSSION...UPDATED 16Z... ADDED TEMPO GROUP FOR TSRA TO ALL TAFS FOR EARLY THIS AFTERNOON. FOLLOWING AN MCV OVER ERN IOWA AND TIMING WOULD BRING ANY ASSOCIATED THUNDERSTORM ACTIVITY TO THE RFD AREA BY ARND 18Z AND THE CHICAGO AREA BY ARND 19-20Z. THE CONVECTIVE ACTIVITY CURRENTLY ASSOCIATED WITH THE SYSTEM IS ON A WEAKENING TREND...BUT IT WILL BE MOVING INTO A MORE CONVECTIVELY FAVORABLY ENVIRONMENT OVER THE NEXT COUPLE HOURS...SO WILL NEED TO BE MONITORED CLOSELY. KREIN UPDATED 12Z... THE CHANCES AND TIMING OF ADDITIONAL CONVECTIVE ACTIVITY WILL BE THE PRIMARILY WEATHER CONCERN ACROSS THE NORTHERN ILLINOIS TERMINALS AGAIN TODAY AND TONIGHT. THE THREAT FOR CONVECTIVE ACTIVITY OVER OR NEAR THE TERMINALS THROUGH THE DAY TODAY APPEARS LOW...BUT NOT ZERO. A WARM...MOIST AND UNSTABLE AIR MASS WILL BE IN PLACE ACROSS THE AREA TODAY. HOWEVER...WITH THE LACK OF ANY SIGNIFICANT TRIGGER MECHANISM TO GET CONVECTION GOING...IT APPEARS THAT ANY ACTIVITY THAT DEVELOPS ACROSS THE AREA DURING THE DAY WILL BE OF FAIRLY LOW AREAL COVERAGE. WITH THIS IN MIND...I WILL CONTINUE TO KEEP THE MENTION OF THUNDER OUT OF THE TAF THROUGH THE DAY. THE NEXT MAIN THREAT FOR A PERIOD OF POSSIBLY MORE WIDESPREAD SHOWERS AND STORMS WILL TONIGHT AHEAD OF AN APPROACHING COLD FRONT. WINDS ARE EXPECTED TO BE GUSTY UP AROUND 25 KT OUT OF THE SOUTH- SOUTHWEST DURING THE DAY TODAY. A COLD FRONT WILL THEN SHIFT ACROSS THE AREA AROUND DAYBREAK ON TUESDAY. THIS WILL RESULT IN A WESTERLY WIND SHIFT ACROSS THE AREA...ALONG WITH THE POTENTIAL FOR SOME LOWER CIGS TO MOVE ACROSS THE AREA. KJB //ORD AND MDW CONFIDENCE...UPDATED 16Z... * MEDIUM-HIGH CONFIDENCE IN WIND FORECAST. * LOW CONFIDENCE CONVECTIVE TIMING AND COVERAGE TODAY AND TONIGHT. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... * TUESDAY NIGHT...VFR. * WEDNESDAY...SLIGHT CHANCE OF PM SHRA. * THURSDAY...CHANCE OF SHRA. * FRIDAY...SLIGHT CHANCE OF SHRA. * SATURDAY AND SUNDAY...DRY/VFR. KJB && .MARINE... 323 AM CDT AN AREA OF LOW PRESSURE ACROSS THE MID MISSOURI VALLEY EARLY THIS MORNING WILL TRACK NORTHEASTWARD TOWARDS LAKE SUPERIOR BY TONIGHT. AS THIS OCCURS...AN ASSOCIATED WARM FRONT IS EXPECTED TO LIFT NORTHWARD UP THE LAKE THROUGH TONIGHT. AREAS OF FOG...POTENTIALLY DENSE WILL BE LIKELY ACROSS PORTIONS OF THE LAKE TODAY AND TONIGHT AS THIS FRONT...AND THE ACCOMPANYING VERY MOIST AIR MASS MOVES OVER THE COOL LAKE WATERS. A MARINE DENSE FOG ADVISORY MAY BE NEEDED. THE OTHER CONCERN WILL BE THE WINDS TODAY AND TONIGHT WITH THIS WARM FRONT LIFTING UP THE LAKE. THE WINDS SOUTH OF THIS WARM FRONT WILL BECOME SOUTHERLY AROUND 25 KT TODAY...WHILE NORTH OF THE WARM FRONT...SOME STOUT EASTERLY WINDS WILL BE LIKELY. THESE GUSTY SOUTHERLY WINDS WILL RESULT IN LIKELY RESULT IN NEAR SMALL CRAFT ADVISORY WINDS OVER THE ILLINOIS AND INDIANA NEAR SHORE WATERS BY MIDDAY. HOWEVER...IN SPITE OF THIS...I HAVE OPTED TO HOLD OFF ON AN ADVISORY DUE TO THERE BEING SOME QUESTION AS TO EXACTLY HOW STRONG THE WINDS WILL BE OVER THE NEAR SHORE WATERS. IN ADDITION...WITH THE OFFSHORE COMPONENT...WAVES WILL LIKELY NOT BUILD OVER 4 FT IN THE NEAR SHORE WATERS. THE POTENTIAL IS CERTAINLY THERE FOR 25+ KT OFFSHORE FLOW TODAY...WITH THE POTENTIAL NEED FOR AN UPGRADE TO A SMALL CRAFT ADVISORY. KJB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM MONDAY. DENSE FOG ADVISORY...LMZ567-LMZ669-LMZ671-LMZ868-LMZ870-LMZ872 UNTIL 3 PM MONDAY. DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565 UNTIL 1 AM TUESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 949 AM CDT Mon May 12 2014 .DISCUSSION... ISSUED 949 AM CDT Mon May 12 2014 Another warm and humid day is unfolding across central Illinois, as 14z/9am temps have already risen well into the 70s. The area remains convection-free for the time being, but as weak capping is broken over the next couple of hours widely scattered thunderstorms will begin to develop. Enhanced Cu field is currently evident on visible satellite imagery from Arkansas northeastward across the eastern half of the KILX CWA. Latest mesoanalysis from SPC indicates deep layer moisture convergence maximized from southeast Missouri into southeast Illinois, where HRRR shows scattered thunderstorm development between now and 18z. Elsewhere around central Illinois, convection will likely remain more isolated in nature until later this afternoon when cold front begins to approach from the west. Front is still progged to reach the area after dark tonight, so best chances for widespread convection will likely hold off until late afternoon/early evening in the Illinois River Valley, then further east across the remainder of the area overnight. Barnes && .AVIATION... ISSUED 641 AM CDT Mon May 12 2014 VFR conditions will start each TAF most of the day. Mid and high clouds will remain over the area this morning and then around noon cigs will fall to around 6kft at all TAF sites, as CU thickens ahead of the cold front. Thunderstorms are expected to develop late this afternoon to the west of the area and then move east into the area...affecting each TAF site...tonight. Lots of uncertainty on timing of the next round of storms...so kept VCTS in TAFs as previously forecasted. Did add a TEMPO group at the end as best first guess on when storms will on station. Winds will be southerly through the period with gusty conditions during the day today. Auten && .PREV DISCUSSION... ISSUED 330 AM CDT Mon May 12 2014 SHORT TERM...Today through Wednesday night Quiet conditions temporarily returned to central and southeast IL early this morning as convection with MCS had shifted east of IL into east central IN and Ohio, and a larger area of convection with a couple MCSS was over WI/IA and eastern KS into far nw MO. Cold front over western IA and eastern KS into central OK and west Texas while warm front was over northern IL. Moist dewpoints in the upper 60s over central and southern IL and mild temps 69-75F with sse winds in warm sector. Strong upper level trof over the Rockies with 557 dm 500 mb low over western CO to eject surface 1002 mb low over east central KS ne into the upper MS river valley by midnight tonight and swing a cold front east across IL overnight. 00Z models are in fair agreement with timing of this cold frontal passage. Isolated to scattered thunderstorms to develop during today especially this afternoon over the IL river valley as air mass destabilizes with CAPES increasing to 1500-2500 J/kg. Best chances of convection will be tonight with slight chance of severe storms nw of IL river this evening. Best risk of severe supercells with possible tornados form mid afternoon into mid evening will be over eastern IA northern MO into far nw IL and sw WI where stronger wind shear will be. Another very warm and humid day with highs in the mid 80s with a few areas se of IL river even seeing upper 80s with enough sunshine. Cold front to pass east into Indiana early Tue morning and have highest chances of convection over eastern IL Tue morning and diminishing to the west. SPC has 5% risk of severe storms Tue from Wabash river east so mostly over IN. Highs Tue range from mid 60s from I-55 west to the low to mid 70s east of I-57 in eastern IL. Looks like a lull in shower chances over central IL Tue night though kept chances of showers over southern areas especially se IL closer to frontal boundary stalling just se of IL. Leaned on wetter ECMWF and NAM models with surface low ejecting ne Wed and passing just se of IL while GFS appears too weak and far to the east with its QPF fields. Have isolated thunderstorms Wed se of I-70 while SPC keeps slight risk of severe storms se of IL Wed. Showers to diminish from the west during Wed night with highest chances near the IN border Wed evening. Cooler highs in the upper 50s and lower 60s Wed and these cooler readings to linger Thu. LONG TERM...Thursday through Monday Medium to long range models and their ensembles continues to advertise large upper level trof over the MS river valley Thu and upper level low lifting north of the Great Lakes this weekend while trof shifts east into the eastern states. As core of coolest 850 mb air shifts ne of central IL during the weekend with upper level low, expect temperatures to modify during this weekend into early next week but generally still stay a below normal. Cool nights in the low to mid 40s Thu night through Sat night. Instability light rain showers possible Thu & Fri especially during the afternoon and early evening with disturbances pivoting thru the nearby upper level trof. Isolated light showers still possible Sat sw of I-74 while dry conditions then prevail from Sat night through Monday. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
105 AM CDT MON MAY 12 2014 .DISCUSSION... 930 PM CDT STORMS ACROSS THE FAR SOUTHERN FORECAST AREA HAVE SHOWN A CONSISTENT WEAKENING TREND IN THE PAST HOUR. STILL SOME CONVERGENCE ON THE OUTFLOW BOUNDARY WITH WARM/MOIST ADVECTION 850-925MB ADVECTION INTO THIS AREA. SO SOME REGENERATION OF STORMS MAY CONTINUE AS RADAR TRENDS HAVE INDICATED IN MCCLEAN COUNTY...ALTHOUGH THE REFLECTIVITY TREND IS GENERALLY DOWNWARDS. SO THE FLOODING THREAT IS GRADUALLY DIMINISHING. TEMPORARY SUPPRESSION AND MID-LEVEL DRYING BEHIND MCS SHOULD KEEP MUCH OF THE FORECAST AREA QUIET THROUGH 3 AM OR SO. WIDESPREAD CONVECTION ACROSS WESTERN IOWA SHOULD EVOLVE EAST NORTHEAST WITH POSSIBLE SCATTERED DEVELOPMENT AHEAD OF THIS ON THE LOW-LEVEL JET AND JUST INCREASING UPPER/MID-LEVEL FORCING. THIS IS MOST FAVORED IN NORTH CENTRAL ILLINOIS...INCLUDING TOWARD ROCKFORD. THIS WOULD HAVE A SMALL SEVERE WEATHER CHANCE. OVERALL BUILDING HEIGHTS SHOULD LIMIT A WELL-DEVELOPED MCS FROM THE WEST MOVING INTO THE FORECAST AREA. MTF //PREV DISCUSSION... 300 PM CDT FORECAST CONCERNS ARE MAINLY ON THE IMMEDIATE SEVERE WEATHER CHANCES THROUGH EARLY/MID EVENING. ALSO FOCUS ON THE SEVERE WEATHER POTENTIAL ON MONDAY...PRIMARILY MONDAY LATE AFTERNOON INTO THE NIGHTTIME PERIOD. OVERNIGHT INTO MONDAY MORNING... STRONG UPPER JET WILL PROPAGATE AROUND THE UPPER TROUGH LATE TONIGHT INTO THE MORNING ON MONDAY AND WITH THAT LEAD TO FURTHER AMPLIFYING OF THE UPSTREAM RIDGE...INCLUDING BUILDING HEIGHTS ACROSS MUCH OF THE FORECAST AREA. MUCH OF THE FORCING FOR RAIN/STORMS IN THIS PERIOD WOULD BE FOCUSED TO THE WEST AND NORTH IN SUCH A PATTERN. THE STRONG LOW-LEVEL JET WILL AT LEAST IN PART BE OVER THE AREA...HOWEVER THE NOSE OF IT WILL BE POINTED FURTHER NORTH. CONVECTIVE CHANCES LOOK MINIMAL AND MAINLY THE NORTHWEST FORECAST AREA TOWARD ROCKFORD. CHANCES MAY BE INCREASED SOMEWHAT IF ANY ORGANIZED CONVECTION FROM THE CENTRAL PLAINS WERE TO PROPAGATE EASTWARD INTO NORTHERN IL...BUT THE GRADUALLY MORE MERIDIONAL FLOW AND ORIENTATION OF FORECAST CORFIDI VECTORS WOULD PUSH MUCH OF THE CONVECTION NORTH OF THE AREA. LOW TEMPS WILL BE BALMY WITH CONTINUED SOUTHERLY FLOW AND HIGH DEW POINT AIR...WITH SOME PLACES EXPERIENCING SOME WARMING OF TEMPS LATER THIS EVENING...ESPECIALLY THOSE IMPACTED BY EARLY EVE CONVECTION AND THOSE COMMUNITIES NEAR THE LAKE SHORE THAT HAD AFTERNOON/EVE COOLING. MONDAY AFTERNOON THROUGH TUESDAY... THE UPPER TROUGH WILL CONTINUE TO AMPLIFY AS THE UPPER JET TO ITS FRONT AND BACK INTENSITY. A WARM AND MUGGY DAY IS ANTICIPATED MONDAY. CONVECTIVE INHIBITION ON MONDAY AFTERNOON DOES LOOK TO BE OVERCOME BUT A FOCUS IS NOT OVERLY EVIDENT IN OUR FORECAST AREA. GRADUALLY MORE CONVERGENCE AND INCREASING DEEP LAYER MOISTURE AND UPWARD MOTION IS FORECAST TO MOVE EASTWARD ACROSS MAINLY NORTH CENTRAL ILLINOIS LATE IN THE DAY INTO EARLY EVE AND EASE ITS WAY EASTWARD THROUGH THE REMAINDER OF THE NIGHT. THIS LOOKS LIKE A PERIOD OF STORMS MOVING NORTHEAST WITHIN THE DEEP MOIST PLUME. THE SEVERE POTENTIAL WOULD SEEM MOST FAVORED WITH THE INITIAL CONVECTION IN THE LATE AFTERNOON/EVE AND THEN A GENERAL WANING LATER INTO THE NIGHT. LOCALLY HEAVY RAINFALL WILL BE PROBABLE IN SOME OF THESE STORMS AS THE PWATS ARE FORECAST TO BE AROUND 1.50 INCHES AND DEEP MOISTURE CONVERGENCE WILL BE ORIENTED PARALLEL TO THE UPPER FLOW. THIS PLUME WILL SHIFT EASTWARD THROUGH TUESDAY MORNING AND LIKELY POPS CERTAINLY SEEM JUSTIFIED TUESDAY MORNING. IF THE FRONT IS SLOW ENOUGH SOME AFTERNOON ENHANCEMENT OF A FEW STORMS COULD HAPPEN IN THE EAST...BUT THIS SEEMS MOST FAVORED EAST OF THE FORECAST AREA AT THIS TIME. THE COLD AIR ADVECTION WITH THE COLD FRONT...ALONG WITH POTENTIALLY SOME ANAFRONTAL SHOWERS...WILL LIKELY LEAD TO FALLING TEMPS IN SOME PLACES AT LEAST AT TIMES ON TUESDAY. WEDNESDAY AND BEYOND... LITTLE CHANGES MADE TO THIS PART OF THE FORECAST DUE TO ONGOING HIGHER IMPACT WEATHER. LARGE MODEL DIFFERENCES EXIST IN THE WED-THU TIME FRAME...WITH THE 12Z EC COMING IN SLOWER AND MORE AGGRESSIVE WITH A LOW RIDING UP THE BAROCLINIC ZONE TO OUR EAST. THIS PROVIDES WIDESPREAD SHOWERS WEDNESDAY AFTERNOON THROUGH EARLY THURSDAY AND PARTICULARY COOL TEMPS. WITH AN EC/GFS/GOING FORECAST BLEND THIS PROVIDES A FEW PERIODS OF CHANCE POPS. TEMPS TO LOOK TO BE BELOW NORMAL NO MATTER WHICH MODEL VERIFIES IN THE WED-FRI TIME FRAME. IF CONDITIONS CLEAR AND SURFACE RIDGING MOVES OVER...POSSIBLY THU NIGHT...THERE PROBABLY WILL BE A CONCERN FOR FROST. MTF && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * POSSIBLE MVFR CIGS EARLY THIS MORNING. * GUSTY SOUTHERLY WINDS TODAY. * TIMING AND CHANCES OF ADDITIONAL TSRA TODAY AND TONIGHT. KJB //DISCUSSION...UPDATED 06Z... CHANCES AND TIMING OF ADDITIONAL CONVECTIVE ACTIVITY WILL BE THE PRIMARILY WEATHER CONCERN ACROSS THE NORTHERN ILLINOIS TERMINALS AGAIN TODAY AND TONIGHT. UNFORTUNATELY...CONFIDENCE IS LOW ON ANY CONVECTIVE ACTIVITY MATERIALIZING ACROSS THE EASTERN TERMINALS TODAY...AND FOR THIS REASON...THE FORECAST REMAINS DRY FOR THE AREA. THE MAIN ATTENTION EARLY THIS MORNING IS OUT WEST ACROSS CENTRAL IOWA...WHERE A COMPLEX OF THUNDERSTORMS IS MOVING EASTWARD. THIS ACTIVITY COULD IMPACT THE TERMINALS LATER THIS MORNING IF IT HOLDS TOGETHER. HOWEVER...CONFIDENCE ON THIS MAKING IT TO THE EASTERN TERMINALS BEFORE WEAKENING...IS TOO LOW TO INCLUDE A MENTION IN THE TAF. TRAJECTORIES FOR THE STORM MOTIONS TEND TO SUPPORT AN EAST-NORTHEASTERLY MOVEMENT OF THROUGH THE EARLY MORNING HOURS...SO I HAVE INCLUDED THE MENTION OF A VCTS IN THE KRFD TAF AFTER 10 UTC THIS MORNING...TO ACCOUNT FOR ANY OF THE REMNANTS OF THIS ACTIVITY POSSIBLY IMPACTING THE TERMINAL. THE WINDS SHOULD BECOME SOUTHERLY TOWARDS DAYBREAK WITH THE SURFACE WARM FRONT STILL EXPECTED TO LIFT NORTH OF THE AREA. AS THIS OCCURS...IT IS POSSIBLE THAT A FEW LOW CLOUDS OR A BRIEF PERIOD OF LOWER CIGS COULD DEVELOP TOWARDS DAYBREAK AS LOWER LEVEL MOISTURE CONTINUES TO STREAM NORTHWARD OVER THE AREA. I CONTINUED THE MENTION OF SOME SCT015 CLOUDS IN THE GOING TAF. THERE IS A SMALL THREAT FOR AN MVFR CIG AROUND 1500 FEET TO DEVELOP FOR A BRIEF PERIOD THIS MORNING...BUT ANY LOWER CIGS SHOULD IMPROVE SHORTLY AFTER DAYBREAK TODAY. THE THREAT FOR CONVECTIVE ACTIVITY OVER OR NEAR THE TERMINALS THROUGH THE DAY TODAY APPEARS LOW...BUT NOT ZERO. IT APPEARS THAT ANY ACTIVITY...IF IT WERE TO DEVELOP ACROSS THE AREA...WOULD BE OF FAIRLY LOW AREAL COVERAGE DUE THE LACK OF ANY SIGNIFICANT TRIGGER MECHANISM ACROSS THE AREA. THERE ARE ALSO SOME CONCERNS ABOUT THE POSSIBILITY OF HIGHER LEVEL CLOUD DEBRIS...FROM THE OVERNIGHT STORMS...LINGERING OVER THE AREA TODAY AND LIMITING THE THREAT FOR ADDITIONAL DEVELOPMENT. THE NEXT MAIN THREAT FOR A PERIOD OF POSSIBLY MORE WIDESPREAD SHOWERS AND STORMS WILL LIKELY BE EITHER LATE MONDAY NIGHT OR EARLY TUESDAY AHEAD OF AN APPROACHING COLD FRONT. KJB //ORD AND MDW CONFIDENCE...UPDATED 06Z... * LOW FOR MVFR CIGS OVERNIGHT/EARLY MORNING. * LOW FOR TSRA DURING THE DAY TODAY. KJB //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... * TUESDAY...TSRA LIKELY IN THE MORNING. * WEDNESDAY...CHANCE OF SHRA. * THURSDAY...CHANCE OF SHRA. * FRIDAY...SLIGHT CHANCE OF SHRA. * SATURDAY...DRY/VFR. && .MARINE... 242 PM...LOW PRESSURE OVER KANSAS WILL MOVE NORTHEAST TO LAKE SUPERIOR TUESDAY MORNING. AS IT DOES...A WARM FRONT EXTENDING EAST FROM THE LOW WILL MOVE NORTH ACROSS THE LAKE TONIGHT THROUGH MONDAY NIGHT...SHIFTING EASTERLY WINDS SOUTHERLY. LOW LEVEL MOISTURE WILL ALSO BE INCREASING AND AS IT SPREADS ACROSS THE COOLER LAKE...AREAS OF FOG ARE POSSIBLE AND SOME OF THE FOG MAY BECOME DENSE. CURRENT WIND SPEEDS ARE FAIRLY LIGHT IN THE 5-15 KT RANGE AND WILL INCREASE INTO THE 15-25KT RANGE AND REMAIN THERE UNTIL A COLD FRONT MOVES ACROSS THE LAKE TUESDAY MORNING. THERE IS A POTENTIAL FOR WINDS TO BE A BIT STRONGER ON MONDAY...ESPECIALLY WITH THE EASTERLY FLOW NORTH OF THE WARM FRONT ACROSS NORTHERN LAKE MICHIGAN. THERE REMAINS UNCERTAINTY REGARDING THE POTENTIAL FOR STRONG NORTHERLY WINDS WEDNESDAY NIGHT INTO THURSDAY AS LOW PRESSURE DEEPENS MOVING NORTH ACROSS THE GREAT LAKES REGION. THIS TIME PERIOD WILL NEED TO BE MONITORED FOR HIGHER NORTHERLY WIND SPEEDS. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1118 PM CDT Sun May 11 2014 .DISCUSSION... ISSUED 927 PM CDT Sun May 11 2014 The rest of WW #144 will be let go at 10 pm CDT. Most of the stronger storms have shifted off to our east with some lingering showers over north central McLean county. Large bow echo over western Iowa tracking east northeast at 45 to 50 mph. Latest HRRR model suggest what is left of the complex may get into western IL just before 12z. Will continue to keep low chance POPs across the north with the remainder of the area expecting to see dry conditions. Overall, the grids are in good shape. Will update the ZFP once our watch expires at 10 pm. && .AVIATION... ISSUED 1115 PM CDT Sun May 11 2014 Main concern will be with the potential for convection, currently over central Iowa, to make it into at least our northern TAF sites by morning. Based on the current movement of the large complex of storms over central Iowa, have decided to add a VCTS group to PIA and BMI between 11z and 14z. Until then, VFR conditions will continue. We should see VFR cigs during the day on Monday with any early morning showers out of the way by 16z or 17z. Then we will wait for more storms along a cold front to move in after 23z from west to east Monday evening. Confidence on coverage not very high this far out for convection so will just include a VCTS group for each site starting out west around 00z with the potential reaching our eastern counties by 03z. Surface winds will be from a 130-160 direction tonight and then turn more southerly on Monday with speeds tonight in the 8 to 13 kt range and then increase in speed to between 12 to 17 kts on Monday with gusts up to 25 kts at times by late morning into the afternoon hours. Smith && .PREV DISCUSSION... ISSUED 248 PM CDT Sun May 11 2014 Air mass destabilizing quickly across central and southeast Illinois early this afternoon. 18Z upper air sounding from our office showing CAPE of around 2600 J/kg with no convective inhibition, although shear values are not especially impressive. Latest SPC mesoanalysis indicates CAPE`s are over 3000 J/kg south of I-72, as dew points of 70 degrees have made it as far north as Taylorville. Warm front extends from southern Nebraska along the Iowa/Missouri border, but becomes more diffuse in northern Illinois where it is more of a dew point discontinuity. Thunderstorms have been percolating most of the day across the Ohio Valley, and a persistent, small MCS is advancing across Iowa. Some development has recently started as well across northeast Missouri south of the main MCS. Has been quiet in our area the last few hours, but latest radar returns are starting to show thunderstorms developing between Taylorville and St Louis. The primary forecast concern remains with the severe weather threat over the next 24 to 36 hours. SHORT TERM...Tonight through Tuesday: Latest runs of the HRRR have been persistent with the Iowa storms affecting more of the northern third of Illinois, with more scattered strong/severe storms affecting our area through about 7 pm. Shear parameters don`t really improve any in our area, so thinking that hail/wind threat will be the primary concerns here with the tornado threat closer to the warm front. After sunset, capping of the atmosphere will begin in the warm sector. Have maintained some 30-40% PoP`s after midnight northwest of the Illinois River, and slight chances as far east as I-55, with dry conditions across the southeast half of the forecast area. Similar convective parameters expected on Monday, with CAPE`s rising to 2500-3000 J/kg, although shear remains on the low side. Day2 slight risk basically along and northwest of the Illinois River, where the shear will be a bit higher as it is closer to the incoming cold front, and severe weather threat will mainly be mid afternoon to early evening. With the front slowing down a tad, will keep any PoP`s east of I-57 around 20% during the day, while likely PoP`s around 60% found during the afternoon along/west of the Illinois River. Have maintained the 60-70% PoP`s everywhere during the night as the front slowly moves through, and over the eastern CWA on Tuesday with some 80% values south of I-70 Tuesday. Severe weather threat on Tuesday appears minimal, and would be near the Indiana border if any did occur. LONG TERM...Wednesday through Sunday: A broad upper trough will be dominating much of the eastern half of the nation into the first part of the weekend, with cool conditions prevailing. The ECMWF has been persistent with a closed upper low forming by late Thursday over the Great Lakes, then lifting northward, while the GFS keeps a more progressive trough. Toward the end of the weekend, the trough will finally start to break down as an upper low digs southward across the Pacific Northwest, causing rising heights over the center of the nation. Most challenging area in this forecast period is with rain on Wednesday. The tail end of the NAM is trending toward the solution favored by the ECMWF and GEM for the last few days, with a surface low riding northeast along the base of the trough, although the NAM is much further west with it. The GFS has keep its surface features much weaker and further east. Have kept the likely PoP`s on Wednesday across the southeast third of the area, although the ECMWF/GEM solutions would likely require this to be expanded further northwest toward the I-55 corridor. Thursday and Friday, the rain will be much more scattered in nature, as weak troughs rotate around through the broad upper trough. Rain chances will diminish this weekend as the upper flow flattens. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
922 PM EDT TUE MAY 13 2014 .SYNOPSIS... ISSUED AT 742 PM EDT TUE MAY 13 2014 A COLD FRONT WILL STALL OUT ACROSS THE REGION TONIGHT AS LOW PRESSURE DEVELOPS ACROSS THE SOUTHERN PLAINS TONIGHT AND MOVES TOWARDS THE AREA WEDNESDAY INTO WEDNESDAY NIGHT. SCATTERED SHOWERS AND MAYBE A FEW THUNDERSTORMS WILL OCCUR TONIGHT WITH INCREASING CHANCES FOR RAIN AND EMBEDDED THUNDERSTORMS ARRIVING MAINLY WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. LOW TEMPERATURES TONIGHT WILL RANGE FROM THE MIDDLE 40S IN SOUTHWESTERN MICHIGAN TO NEAR 60 ALONG THE OHIO RIVER. HIGHS WEDNESDAY WILL ONLY REACH THE MIDDLE 50S TO MIDDLE 60S. && .UPDATE... ISSUED AT 916 PM EDT TUE MAY 13 2014 GRIDS/ZONES PATCHED UP TO KEEP HIGHER POPS SE THROUGH AROUND 6Z AND THEN TRANSITION HIGHER (YET ONLY CHC) POPS TO NW OVERNIGHT. STRONGEST CONVECTION ACROSS CENTRAL INDIANA WILL MAINLY BYPASS THE SE AREAS OF THE CWA. HOWEVER...EXPANDING AREA OF RAIN/EMBEDDED THUNDER MAY STILL CLIP SE SECTIONS...WARRANTING CONTINUED LIKELY POPS WITH MENTION OF THUNDER. AS THIS DEPARTS...A WEAK DISTURBANCE WILL MOVE OUT OF NE MISSOURI/SW ILLINOIS AND TRACK TOWARDS CENTRAL/WEST SECTIONS OF THE AREA BRINGING A DECENT SHOT AT SOME LIGHT RAIN/SHOWERS INTO THE OVERNIGHT HOURS. HRRR HAS BEEN GENERALLY SPOT ON FOR MOST OF THE ACTIVITY THUS FAR SO WILL LEAN TOWARDS IT FOR THE GRIDS. REST OF THE FORECAST GENERALLY ON TRACK. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 432 PM EDT TUE MAY 13 2014 THUNDERSTORMS WERE SPREADING ACROSS THE AREA THIS AFTERNOON ALONG A PRE/FRONTAL TROF...BUT FARTHER AHEAD OF THE COLD FRONT. THE AIRMASS HAD DESTABILIZED THIS AFTERNOON WITH DAYTIME HEATING...WITH SFC BASED CAPE VALUES RISING WELL ABOVE 2000 J/KG IN FRONT OF THE STORMS PER SPC MESO ANALYSIS. MARGINAL SEVERE THREAT WILL END LATE THIS AFTERNOON AS THE FRONT MOVES EAST...AND AS COOLER AND DRIER AIR TEMPORARILY SPREADS BACK INTO THE AREA. PRECIPITABLE WATER VALUES AS HIGH AS 1.75...BUT STORMS WERE MOVING FAST ENOUGH TO KEEP NEARLY ALL RAINFALL AMOUNTS UNDER AN INCH. A SHORT WAVE TROF WILL LIFT NORTHEAST WEDNESDAY...WITH RAIN SPREADING ACROSS THE AREA AS THIS SYSTEM WILL BE ABLE TO TAP CONSIDERABLE MOISTURE. FAVORED THE 12KM NAM WHICH HAS BEEN REASONABLY CONSISTENT FROM RUN TO RUN AND APPEARS TO BE HANDLING THE EJECTING UPPER TROF WELL. RAISED RAIN CHANCES WEDNESDAY TO COME MORE IN LINE WITH THESE EXPECTATIONS. && .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 432 PM EDT TUE MAY 13 2014 POTENT SW DISTURBANCE EDGING OUT OF NM THIS AFTN AND THROUGH THE SRN PLAINS TONIGHT WILL INDUCE A DEEPENING FNTL WAVE ALG TRAILING CDFNT WED AS THE ENTIRE SYS TURNS NE AND PHASES W/NRN STREAM SW AMPLIFYING RAPIDLY SEWD. NET RESULT LOOKS TO BE A SIG CYCLONE WRAPPING UP ACRS THE WRN OH VALLEY. TRACK OF SFC LOW FM SW-NE INDIANA POINTS TO HEAVIEST RAINFALL RIGHT THROUGH CNTRL/WRN CWA W/LOW TOPPED CONVN LIKELY ERN HALF. WILL EXPAND THUNDER WWD WED NIGHT. SYS LIFTS OUT RAPIDLY NEWD THU-FRI W/SOME DIURNALLY FVRD SHRA PSBL N/NE THU AFTN AND S/SE FRI AFTN AS COLD POOL ALOFT SETTLES IN OVERHEAD. OTRWS UNSEASONABLY COLD THROUGH SUN W/PEAK DEPARTURES NR -20 DEGREES THU-FRI. MOIST CYCLONIC FLW AND LIKELY EXTENSIVE LOW CLD CVR SHLD STAVE OFF POTENTIAL FROST THU/FRI NIGHT BUT W/MORE SIG DRYING INDICATED SAT AFTN AND POSITION OF SFC RIDGE AXIS WORRIED SOMEWHAT THAT NRN AREAS COULD FROST SUN AM HWVR WILL AWAIT SPECIFICS OFFERED VIA SHORTER TERM MOS GUIDANCE WINDOW BY THU. OTRWS PATTN PROGRESSION ALOFT WILL YIELD SIG WARMING TREND TO AOA NORMAL BY WED AS NEW TROUGH DIGS IN OUT WEST. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 732 PM EDT TUE MAY 13 2014 POOR FLIGHT CONDITIONS EXPECTED DURING THE PERIOD...ESPECIALLY GOING INTO TUESDAY. COLD FRONT SHOULD REACH KFWA IN NEXT HOUR OR 2 BUT THEN LIKELY STALL OUT NEARBY. LOW CLOUDS/FOG/AREAS OF DRIZZLE AND SHOWERS WILL PERSIST MUCH OF THE EVENING AT BOTH SITES WITH HI RES MODELS POINTING TOWARDS A PERIOD OF STEADIER RAIN VS LIGHTER PCPN AT KSBN. CONVECTION MOVING UP FROM CENTRAL/SOUTHERN INDIANA MAY MOVE NEAR OR JUST EAST OF KFWA. WILL MONITOR TRENDS. OTHERWISE HEAVIER PRECIP AND RENEWED CHANCES FOR CONVECTION WILL ARRIVE WEDS AFTERNOON INTO WEDS NGT AS LOW PRESSURE MOVES ALONG THE FRONT AND BRINGS WIDESPREAD RAIN AND EMBEDDED STORMS. STILL SOME TIMING ISSUES SO WILL ATTEMPT TO GIVE BROAD BRUSHED IMPACTS AFTER 19Z WEDS AND LET LATER FORECASTS FINE TUNE LOWER CIGS/VSBYS. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ UPDATE...FISHER SYNOPSIS...FISHER SHORT TERM...SKIPPER LONG TERM...T AVIATION...FISHER VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
629 PM CDT TUE MAY 13 2014 .SYNOPSIS... ISSUED AT 309 PM CDT TUE MAY 13 2014 TEMPERATURES WERE RUNNING 25 TO 30 DEGREES COLDER THAN 24 HOURS AGO ACROSS THE FORECAST AREA THIS AFTERNOON IN THE WAKE OF THE STRONG FRONT THAT PUSHED THROUGH OVERNIGHT. AT 19Z...THE SHARP COLD FRONT WAS WELL TO THE EAST FROM LOWER MI SOUTH TO LA. AN EXPANSIVE POST FRONTAL STRATUS DECK EXTENDED WEST INTO CENTRAL IA. THE CLOUDS... COMBINED WITH LOW LEVEL COLD ADVECTION ON NW WINDS...WAS LIMITING TEMPERATURES TO THE LOWER TO MID 50S. RADAR MOSAIC INDICATED A FEW DEVELOPING LIGHT SHOWERS LIKELY ALONG THE LAGGING 850 MB FRONT OVER W CENTRAL IL NEAR MACOMB. 12Z UPPER AIR ANALYSIS SHOWED AN UPPER TROUGH REACHING FROM A LOW OVER SOUTHERN CANADA TO A SEPARATE SOUTHERN STREAM VORTEX EMBEDDED IN THE LARGER TROUGH AXIS NEAR THE OK PANHANDLE. UNSEASONABLY COLD TEMPERATURES AROUND ZERO TO SEVERAL DEGREES BELOW AT 850 MB WERE FOUND BEHIND THE FRONT IN THE NW FLOW ACROSS THE DAKOTAS INTO MN AND NW IA. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 309 PM CDT TUE MAY 13 2014 MAIN FOCUS IS ON COOL TEMPERATURES AND POTENTIAL FOR LIGHT PRECIPITATION. TONIGHT...A DEVELOPING MORE ANTICYCLONIC LOW LEVEL FLOW...BACKED BY RAP LOW LEVEL RH FIELDS INDICATES THE STRATUS DECK GRADUALLY CLEARING FROM WEST TO EAST FROM LATE AFTERNOON THROUGH MID EVENING. AT THE SAME TIME...MID AND HIGH LEVEL MOISTURE IN THE SW WITH SUPPORT FROM EMBEDDED VORT MAXIMA WILL KEEP HIGH LEVEL CLOUD COVER IN PLACE. THIS CLOUD COVER SHOULD ELIMINATE THE THREAT OF FREEZING TEMPERATURE OR FROST TONIGHT...BUT STILL LEAD TO WELL BELOW NORMAL TEMPERATURES AS THE 850 MB THERMAL TROUGH PASSING OVERHEAD TOWARD MORNING SENDS TEMPERATURES AT THAT LEVEL CLOSE TO ZERO C. HAVE KEPT MINS NEAR TO BELOW THE LOW END OF GUIDANCE FROM THE UPPER 30S NW TO MID 40S SE. DIURNALLY ENHANCE SHOWERS OVER THE FAR EAST AND SOUTHEAST SHOULD DISSIPATE BY THIS EVENING. WEDNESDAY...THE UPPER LOW OVER THE SOUTHERN PLAINS GETS PULLED NORTHEAST...SENDING LIFT INTO NORTHERN IL BY AFTERNOON. THIS...ALONG WITH A FAVORABLE RIGHT ENTRANCE REGION OF THE UPPER JET LIFTING N-NE INTO EASTERN CANADA WILL SUPPORT SHOWERS MAINLY EAST OF THE MS RIVER IN THE AFTERNOON. WILL KEEP HIGH CHANCE POPS GOING FOR WHAT SHOULD BE A VERY LOW QPF EVENT BASED ON LIMITED MOISTURE AND A DRY LAYER IN THE LOW LEVELS IN FORECAST SOUNDINGS. IN THE SAME AIRMASS AS TODAY...TEMPERATURES SHOULD BE LIMITED TO THE 50S IN THE THICKEST CLOUD COVER AND DEVELOPING SHOWERS ACROSS THE EAST...WHILE HIGHER CLOUD COVER AND DRY AIR MAY ALLOW AREAS WEST OF THE MS RIVER TO REACH THE UPPER 50S TO PERHAPS LOWER 60S. OVERALL...MODEL GUIDANCE MUCH LIKE TODAY LOOKED A BIT TOO OPTIMISTIC IN THE AMOUNT OF WARMING IN THIS AIRMASS AND HAVE TRENDED NEAR TO BELOW THE COOLEST NUMBERS. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 309 PM CDT TUE MAY 13 2014 FORECAST FOCUS ON BELOW NORMAL TEMPERATURES THROUGH THE EXTENDED. WEDNESDAY NIGHT THROUGH FRIDAY...STRONG ENERGY IN THE SOUTHERN STREAM PHASES WITH THE NORTHERN STREAM TO CARVE OUT A MAJOR TROUGH IN THE MIDDLE OF THE COUNTRY. CYCLOGENESIS DEVELOPS IN THE LOWER MS VALLEY ON WEDNESDAY AND RIDES UP A STALLED FRONT INTO THE OHIO VALLEY AND EASTERN GREAT LAKES BY THURSDAY. THIS WILL DUMP CHILLY AIR INTO MUCH OF THE MIDWEST WITH BELOW TO WELL BELOW NORMAL TEMPERATURES THE REMAINDER OF THIS WEEK INTO THE WEEKEND. 850 MB TEMPERATURES ARE PROGGED TO ABOUT -2C OVER THE CWA. MODELS SIMILAR IN KEEPING THE BULK OF THE RAIN...TIED TO THE SURFACE LOW MOVING INTO THE OHIO VALLEY...TO THE EAST OF THE DVN CWA. I WILL CONTINUE WITH CHANCE POPS IN THE FORM OF SCATTERED SHOWERS ESPECIALLY THURSDAY AND FRIDAY DURING THE AFTERNOON AND EARLY EVENING. THIS WILL BE INSTABILITY SHOWERS DUE TO THE COLD AIR ALOFT ASSOCIATED WITH THE VERY IMPRESSIVE (FOR MAY) DEEP TROUGH. EXTENSIVE CLOUD COVER THE REMAINDER OF THIS WEEK WILL KEEP AFTERNOON MAXIMUM TEMPERATURES MAINLY IN THE 50S...WITH LOWS IN THE UPPER 30S TO MID 40S. THE CLOUD COVER WILL PREVENT ANY FROST FORMATION THIS WORK WEEK. FRIDAY NIGHT THROUGH THE WEEKEND...AT THIS POINT IN THE GAME THE FAVORED TIME FOR AT LEAST SCATTERED FROST AND POSSIBLE HEADLINES APPEAR TO BE FRIDAY NIGHT/EARLY SATURDAY MORNING. MODELS SUGGEST A HIGH PRESSURE RIDGE SETTLING INTO THE REGION WITH CLEAR SKIES AND LIGHT WINDS ALLOWING FOR GOOD RADIATIONAL COOLING. LOW TEMPERATURES SHOULD DIP INTO THE 30S BUT EXACT NUMBERS REMAIN TO BE SEEN. DEEP TROUGH BEGINS TO SHIFT TO THE EAST OVER THE WEEKEND ALLOWING FOR A MODERATION IN TEMPERATURES AND RATHER PLEASANT WEATHER. MAXIMUM TEMPERATURES SHOULD PUSH INTO THE 60S WITH LOWS IN THE 40S. EARLY NEXT WEEK...THE 12Z ECMWF HAS BACKED OFF ON SURGING WARMER AIR INTO THE CWA...AND A MORE ACTIVE PATTERN...PUSHING IT OFF UNTIL THE MIDDLE AND END OF NEXT WEEK. ECMWF/GFS WANT TO HANG ON TO THE TROUGH IN THE EAST A BIT LONGER KEEPING TEMPERATURES A BIT BELOW NORMAL AND HOLDING OFF THE RAIN. WE WILL SEE. 21 && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 623 PM CDT TUE MAY 13 2014 EXPECT VFR CONDITIONS FOR THE NEXT 24 HOURS WITH PARTIAL CLEARING OF SKIES TONIGHT WITH SOME INCREASE IN HIGHER LEVEL CLOUDS BY LATE WEDNESDAY AFTERNOON. COOLER AND DRIER AIR IS SPILLING INTO THE UPPER MIDWEST. FEW-SCT CLOUD BASES AOA 4K AGL BY 14/01Z WITH SOME HIGH CLOUDS...THEN BRL/MLI TERMINALS TO SEE BKN-OVC CLOUDS WITH CIGS AOA 5K AGL TOWARD 14/22Z. NORTHWEST WINDS OF 5 TO 15 KTS TONIGHT TO SHIFT TO THE NORTH AT 5 TO 10 KTS WEDNESDAY. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...11 SHORT TERM...11 LONG TERM...21 AVIATION...NICHOLS
AREA FORECAST DISCUSSION
NWS DES MOINES IA
102 PM CDT MON MAY 12 2014 .SHORT TERM /TODAY/... ISSUED AT 321 AM CDT MON MAY 12 2014 TWO PROBLEMS TODAY ARE BOTH WITH CONVECTION THE EARLY MORNING CONVECTION WILL BE AN ISSUE WITH THE POTENTIAL FOR LOCALLY HEAVY RAINFALL MOVING INTO ALREADY SATURATED AREAS. THIS IS ASSOCIATED WITH A WEAK WAVE IN THE FLOW THAT IS LIFTING NORTHEAST ACROSS THE STATE. ADDITIONAL DEVELOPMENT IS LIKELY OVER THE SOUTHEAST HALF OF THE STATE WITH THE COLD FRONT PROGRESSING EAST. THE HRRR HAS WHAT SEEMS TO BE A REASONABLE HANDLE ON THIS. SEVERITY WILL DEPEND ON HOW MUCH RECOVERY WE CAN ACHIEVE AFTER THE MORNING CONVECTION. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 321 AM CDT MON MAY 12 2014 PRECIPITATION WILL MOVE OUT OF THE STATE BY 06Z AS THE PATTERN CHANGES FROM A SOUTHWEST FLOW TO A NORTHWEST FLOW. CANADIAN HIGH PRESSURE WILL DOMINATE THE WEEKS WEATHER WITH TEMPERATURES WELL BELOW NORMAL. WILL POTENTIAL NEED TO CONSIDER SOME FROST WORDING LATER IN THE WEEK, BUT CERTAINTY IS NOT THERE AT THIS TIME BECAUSE OF THE POTENTIAL FOR SOME CLOUD COVER. IT WILL LIKELY TAKE UNTIL THE WEEKEND BEFORE THE COOL HIGH PRESSURE MOVES OFF TO THE EAST. WARMING AND AN INCREASED CHANCE FOR THUNDERSTORMS IS EXPECTED LATER IN THE WEEKEND. && .AVIATION...12/18Z ISSUED AT 102 PM CDT MON MAY 12 2014 UNSETTLED WEATHER EXPECTED THRU THE TAF PD AS A SFC COLD FRONT SWEEPS THRU THE RGN. SHRA/TSRA POSSIBLE THRU THIS EVE AT THE KOTM...KDSM AND KALO TERMINALS. IFR/MVFR CIGS FILL IN BEHIND THE FROPA. IFR/MVFR CIGS EXPECTED TO LIFT BY 15Z TUE. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...MS MAY 14 LONG TERM...MS MAY 14 AVIATION...ZOGG
AREA FORECAST DISCUSSION
NWS DES MOINES IA
708 AM CDT MON MAY 12 2014 .SYNOPSIS... ISSUED AT 321 AM CDT MON MAY 12 2014 LOW PRESSURE MOVING INTO WESTERN IA WILL LIFT NORTHEAST AS COLD FRONT SWEEPS ACROSS THE STATE BY LATE TONIGHT. PATTERN WILL CHANGE TO A MUCH COOLER REGIME AS CANADIAN HIGH PRESSURE DOMINATES THROUGH THE REST OF THE WORK WEEK. && .UPDATE... ISSUED AT 704 AM CDT MON MAY 12 2014 UPDATED FORECAST FOR MINOR ADJUSTMENTS TO PRECIP TRENDS AND TEMP TRENDS. ALSO FOR REMOVAL OF HEADLINES. && .SHORT TERM /TODAY/... ISSUED AT 321 AM CDT MON MAY 12 2014 TWO PROBLEMS TODAY ARE BOTH WITH CONVECTION THE EARLY MORNING CONVECTION WILL BE AN ISSUE WITH THE POTENTIAL FOR LOCALLY HEAVY RAINFALL MOVING INTO ALREADY SATURATED AREAS. THIS IS ASSOCIATED WITH A WEAK WAVE IN THE FLOW THAT IS LIFTING NORTHEAST ACROSS THE STATE. ADDITIONAL DEVELOPMENT IS LIKELY OVER THE SOUTHEAST HALF OF THE STATE WITH THE COLD FRONT PROGRESSING EAST. THE HRRR HAS WHAT SEEMS TO BE A REASONABLE HANDLE ON THIS. SEVERITY WILL DEPEND ON HOW MUCH RECOVERY WE CAN ACHIEVE AFTER THE MORNING CONVECTION. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 321 AM CDT MON MAY 12 2014 PRECIPITATION WILL MOVE OUT OF THE STATE BY 06Z AS THE PATTERN CHANGES FROM A SOUTHWEST FLOW TO A NORTHWEST FLOW. CANADIAN HIGH PRESSURE WILL DOMINATE THE WEEKS WEATHER WITH TEMPERATURES WELL BELOW NORMAL. WILL POTENTIAL NEED TO CONSIDER SOME FROST WORDING LATER IN THE WEEK, BUT CERTAINTY IS NOT THERE AT THIS TIME BECAUSE OF THE POTENTIAL FOR SOME CLOUD COVER. IT WILL LIKELY TAKE UNTIL THE WEEKEND BEFORE THE COOL HIGH PRESSURE MOVES OFF TO THE EAST. WARMING AND AN INCREASED CHANCE FOR THUNDERSTORMS IS EXPECTED LATER IN THE WEEKEND. && .AVIATION...12/12Z ISSUED AT 544 AM CDT MON MAY 12 2014 LOW PRESSURE OVER SERN NEBRASKA WILL MOVE NORTHEAST THROUGH WESTERN IA AND INTO MINNESOTA BY THIS EVENING. TRAILING COLD FRONT WILL MOVE EAST ACROSS THE TAF SITES LATER TODAY AND THIS EVENING. AREA OF THUNDERSTORMS ARE EXPECTED ALONG AND AHEAD OF THE COLD FRONT TODAY...WITH MVFR STRATUS SPREADING INTO THE AREA BEHIND THE COLD FRONT. MVFR CIGS WILL HOLD THROUGH THE NIGHT. OUTLOOK...HIGH PRESSURE WILL BUILD INTO THE AREA TUE AND WED AND DOMINATE THE WEATHER THROUGH THE WORK WEEK. SEVERAL MINOR DISTURBANCES WILL MOVE THROUGH...BUT CONDITIONS WILL REMAIN VFR. && .HYDROLOGY... ISSUED AT 704 AM CDT MON MAY 12 2014 THUNDERSTORMS CONTINUE TO LIVE NORTHEAST ACROSS THE STATE AHEAD OF THE APPROACHING COLD FRONT. THE HEAVIER STORMS WILL MOVE OVER AREAS THE DID NOT RECEIVE A LOT OF RAIN DURING THE PAST 24 HOURS. THE RAIN IS EXPECTED TO END BY MID MORNING. ADDITIONAL SCATTERED THUNDERSTORMS WILL DEVELOP THIS AFTERNOON...ESPECIALLY EAST OF INTERSTATE 35. THEY ARE NOT EXPECTED TO PRODUCE FLASH FLOODING HOWEVER. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MS MAY 14 SYNOPSIS...MS MAY 14 SHORT TERM...MS MAY 14 LONG TERM...MS MAY 14 AVIATION...MS MAY 14 HYDROLOGY...MS MAY 14
AREA FORECAST DISCUSSION
NWS DES MOINES IA
547 AM CDT MON MAY 12 2014 .SYNOPSIS... ISSUED AT 321 AM CDT MON MAY 12 2014 LOW PRESSURE MOVING INTO WESTERN IA WILL LIFT NORTHEAST AS COLD FRONT SWEEPS ACROSS THE STATE BY LATE TONIGHT. PATTERN WILL CHANGE TO A MUCH COOLER REGIME AS CANADIAN HIGH PRESSURE DOMINATES THROUGH THE REST OF THE WORK WEEK. && .SHORT TERM /TODAY/... ISSUED AT 321 AM CDT MON MAY 12 2014 TWO PROBLEMS TODAY ARE BOTH WITH CONVECTION THE EARLY MORNING CONVECTION WILL BE AN ISSUE WITH THE POTENTIAL FOR LOCALLY HEAVY RAINFALL MOVING INTO ALREADY SATURATED AREAS. THIS IS ASSOCIATED WITH A WEAK WAVE IN THE FLOW THAT IS LIFTING NORTHEAST ACROSS THE STATE. ADDITIONAL DEVELOPMENT IS LIKELY OVER THE SOUTHEAST HALF OF THE STATE WITH THE COLD FRONT PROGRESSING EAST. THE HRRR HAS WHAT SEEMS TO BE A REASONABLE HANDLE ON THIS. SEVERITY WILL DEPEND ON HOW MUCH RECOVERY WE CAN ACHIEVE AFTER THE MORNING CONVECTION. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 321 AM CDT MON MAY 12 2014 PRECIPITATION WILL MOVE OUT OF THE STATE BY 06Z AS THE PATTERN CHANGES FROM A SOUTHWEST FLOW TO A NORTHWEST FLOW. CANADIAN HIGH PRESSURE WILL DOMINATE THE WEEKS WEATHER WITH TEMPERATURES WELL BELOW NORMAL. WILL POTENTIAL NEED TO CONSIDER SOME FROST WORDING LATER IN THE WEEK, BUT CERTAINTY IS NOT THERE AT THIS TIME BECAUSE OF THE POTENTIAL FOR SOME CLOUD COVER. IT WILL LIKELY TAKE UNTIL THE WEEKEND BEFORE THE COOL HIGH PRESSURE MOVES OFF TO THE EAST. WARMING AND AN INCREASED CHANCE FOR THUNDERSTORMS IS EXPECTED LATER IN THE WEEKEND. && .AVIATION...12/12Z ISSUED AT 544 AM CDT MON MAY 12 2014 LOW PRESSURE OVER SERN NEBRASKA WILL MOVE NORTHEAST THROUGH WESTERN IA AND INTO MINNESOTA BY THIS EVENING. TRAILING COLD FRONT WILL MOVE EAST ACROSS THE TAF SITES LATER TODAY AND THIS EVENING. AREA OF THUNDERSTORMS ARE EXPECTED ALONG AND AHEAD OF THE COLD FRONT TODAY...WITH MVFR STRATUS SPREADING INTO THE AREA BEHIND THE COLD FRONT. MVFR CIGS WILL HOLD THROUGH THE NIGHT. OUTLOOK...HIGH PRESSURE WILL BUILD INTO THE AREA TUE AND WED AND DOMINATE THE WEATHER THROUGH THE WORK WEEK. SEVERAL MINOR DISTURBANCES WILL MOVE THROUGH...BUT CONDITIONS WILL REMAIN VFR. && .HYDROLOGY... ISSUED AT 321 AM CDT MON MAY 12 2014 THEN ENVIRONMENT REMAINS FAVORABLE FOR HEAVY RAINFALL AT LEAST THROUGH EARLY THIS MORNING WITH THE LOW PRESSURE AND COLD FRONT CLOSE. DECENT DEVELOPMENT OVER WESTERN IOWA AND TO THE SOUTHWEST OF THE STATE WILL MOVE NORTHEAST THROUGH THE STATE THIS MORNING. MOST VULNERABLE AREAS WILL BE THE SOUTHWEST AND SOUTH CENTRAL AREAS...AND SOME IN THE NORTHWEST...WHERE RAINFALL TOTALS HAVE BEEN IN THE 2 TO 3 INCH RAIN LOCALLY WITH SOME HIGHER TOTALS. ADDITIONAL THUNDERSTORM DEVELOPMENT LATER IN THE DAY IS LIKELY TO BE EAST OF THESE AREAS AND TO NOW ANTICIPATE EXTENDING THE FLASH FLOOD WATCH AT THIS TIME. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR ADAIR-ADAMS- AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CASS- CERRO GORDO-CRAWFORD-DALLAS-EMMET-FRANKLIN-GREENE-GRUNDY-GUTHRIE- HAMILTON-HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-MADISON-MARSHALL-PALO ALTO-POCAHONTAS-POLK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-UNION- WEBSTER-WINNEBAGO-WORTH-WRIGHT. && $$ SYNOPSIS...MS MAY 14 SHORT TERM...MS MAY 14 LONG TERM...MS MAY 14 AVIATION...MS MAY 14 HYDROLOGY...MS MAY 14
AREA FORECAST DISCUSSION
NWS DES MOINES IA
332 AM CDT MON MAY 12 2014 .SYNOPSIS... ISSUED AT 321 AM CDT MON MAY 12 2014 LOW PRESSURE MOVING INTO WESTERN IA WILL LIFT NORTHEAST AS COLD FRONT SWEEPS ACROSS THE STATE BY LATE TONIGHT. PATTERN WILL CHANGE TO A MUCH COOLER REGIME AS CANADIAN HIGH PRESSURE DOMINATES THROUGH THE REST OF THE WORK WEEK. && .SHORT TERM /TODAY/... ISSUED AT 321 AM CDT MON MAY 12 2014 TWO PROBLEMS TODAY ARE BOTH WITH CONVECTION THE EARLY MORNING CONVECTION WILL BE AN ISSUE WITH THE POTENTIAL FOR LOCALLY HEAVY RAINFALL MOVING INTO ALREADY SATURATED AREAS. THIS IS ASSOCIATED WITH A WEAK WAVE IN THE FLOW THAT IS LIFTING NORTHEAST ACROSS THE STATE. ADDITIONAL DEVELOPMENT IS LIKELY OVER THE SOUTHEAST HALF OF THE STATE WITH THE COLD FRONT PROGRESSING EAST. THE HRRR HAS WHAT SEEMS TO BE A REASONABLE HANDLE ON THIS. SEVERITY WILL DEPEND ON HOW MUCH RECOVERY WE CAN ACHIEVE AFTER THE MORNING CONVECTION. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 321 AM CDT MON MAY 12 2014 PRECIPITATION WILL MOVE OUT OF THE STATE BY 06Z AS THE PATTERN CHANGES FROM A SOUTHWEST FLOW TO A NORTHWEST FLOW. CANADIAN HIGH PRESSURE WILL DOMINATE THE WEEKS WEATHER WITH TEMPERATURES WELL BELOW NORMAL. WILL POTENTIAL NEED TO CONSIDER SOME FROST WORDING LATER IN THE WEEK, BUT CERTAINTY IS NOT THERE AT THIS TIME BECAUSE OF THE POTENTIAL FOR SOME CLOUD COVER. IT WILL LIKELY TAKE UNTIL THE WEEKEND BEFORE THE COOL HIGH PRESSURE MOVES OFF TO THE EAST. WARMING AND AN INCREASED CHANCE FOR THUNDERSTORMS IS EXPECTED LATER IN THE WEEKEND. && .AVIATION...12/06Z ISSUED AT 1249 AM CDT MON MAY 12 2014 THUNDERSTORMS WILL REMAIN POSSIBLE OVERNIGHT ESPECIALLY OVER THE SOUTHEAST SITES. GUSTY WINDS FROM THE WEST TO SOUTHWEST ARE POSSIBLE WITH STORM OUTFLOW ALONG WITH GREATLY REDUCED VSBYS WITH HEAVY RAINFALL. THE PRECIPITATION SHOULD DIMINISH EARLY MONDAY MORNING BEFORE INCREASING AGAIN LATE MORNING AND INTO THE AFTERNOON. MVFR CIGS ARE EXPECTED TO DEVELOP MONDAY. A FRONTAL BOUNDARY WILL ARRIVE LATE WITH A SWITCH TO WESTERLY WINDS. && .HYDROLOGY... ISSUED AT 321 AM CDT MON MAY 12 2014 THEN ENVIRONMENT REMAINS FAVORABLE FOR HEAVY RAINFALL AT LEAST THROUGH EARLY THIS MORNING WITH THE LOW PRESSURE AND COLD FRONT CLOSE. DECENT DEVELOPMENT OVER WESTERN IOWA AND TO THE SOUTHWEST OF THE STATE WILL MOVE NORTHEAST THROUGH THE STATE THIS MORNING. MOST VULNERABLE AREAS WILL BE THE SOUTHWEST AND SOUTH CENTRAL AREAS...AND SOME IN THE NORTHWEST...WHERE RAINFALL TOTALS HAVE BEEN IN THE 2 TO 3 INCH RAIN LOCALLY WITH SOME HIGHER TOTALS. ADDITIONAL THUNDERSTORM DEVELOPMENT LATER IN THE DAY IS LIKELY TO BE EAST OF THESE AREAS AND TO NOW ANTICIPATE EXTENDING THE FLASH FLOOD WATCH AT THIS TIME. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR ADAIR-ADAMS- AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CASS- CERRO GORDO-CRAWFORD-DALLAS-EMMET-FRANKLIN-GREENE-GRUNDY-GUTHRIE- HAMILTON-HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-MADISON-MARSHALL-PALO ALTO-POCAHONTAS-POLK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-UNION- WEBSTER-WINNEBAGO-WORTH-WRIGHT. && $$ SYNOPSIS...MS MAY 14 SHORT TERM...MS MAY 14 LONG TERM...MS MAY 14 AVIATION...DONAVON HYDROLOGY...MS MAY 14
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1142 PM CDT SUN MAY 11 2014 .UPDATE... ISSUED AT 635 PM CDT SUN MAY 11 2014 DATA TRENDS THE PAST 3 HOURS NOW INDICATE THERE WILL BE A BREAK IN ACTIVITY DURING THE EVENING HOURS. THE CURRENT THUNDERSTORM COMPLEX IS SLOWLY MOVING INTO NORTHEAST ILLINOIS BUT BOUNDARIES LEFT OVER WILL ALLOW STORMS TO PERSIST OVER THE SOUTHERN PARTS OF THE AREA FOR THE NEXT SEVERAL HOURS. AN EFFECTIVE BOUNDARY IS EVIDENT ACROSS SOUTHERN IOWA WITH NO CELLULAR CLOUDS NORTH OF THE BOUNDARY AND DIURNAL CLOUDS ACROSS MISSOURI. THIS BOUNDARY MAY PROVIDE A FOCUS FOR ADDITIONAL ISOLATED TO SCATTERED STORMS THROUGH SUNSET. DATA STILL SUGGESTS THE STORMS IN NEBRASKA WILL EVOLVE INTO A NEW THUNDERSTORM COMPLEX ACROSS WESTERN IOWA THIS EVENING IN THE BETTER FORCING AND SLOWLY MOVE EASTWARD WITH ACTIVITY ENTERING THE NORTHWEST HALF OF THE AREA AFTER MIDNIGHT. && .SYNOPSIS... ISSUED AT 356 PM CDT SUN MAY 11 2014 12Z UA ANALYSIS HAS 850MB LOWS IN NORTHWEST MINNESOTA WITH A STRONG 850MB LOW IN WESTERN KANSAS. AN 850MB WARM FRONT RAN FROM THE KANSAS LOW INTO SOUTHERN IOWA. A STRONG LLJ RAN FROM THE GULF COAST INTO THE CENTRAL PLAINS. SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON HAS CONVECTION ACROSS EASTERN IOWA AND NORTHERN ILLINOIS WITH NEW CONVECTION DEVELOPING IN THE PLAINS. 18Z SFC ANALYSIS HAS A WEAK LOW IN WESTERN WISCONSIN WITH A DEVELOPING WARM FRONT SOUTHEAST INTO CENTRAL LAKE MICHIGAN. AN IMPLIED LOW WAS IN SOUTHERN IOWA APPROACHING KOTM WITH ANOTHER LOW IN WESTERN KANSAS. A FRONTAL BOUNDARY RAN FROM THE KANSAS LOW INTO THE IOWA LOW NEAR KOTM WITH A WARM FRONT FROM NEAR KOTM NORTHEAST TO THE WISCONSIN/ILLINOIS BORDER. DEW POINTS SOUTH OF THE FRONT WERE IN THE 60S WITH 40S AND 50S IN THE NORTHERN PLAINS INTO THE GREAT LAKES NORTH OF THE FRONT. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 356 PM CDT SUN MAY 11 2014 BOUNDARIES FROM THE NOCTURNAL THUNDERSTORM COMPLEX INITIATED A NEW STORM COMPLEX ALONG THE WARM FRONT IN SOUTHERN IOWA THIS MORNING. THIS NEW STORM COMPLEX MOVED EAST NORTHEAST AND IS SLOWLY DECAYING ACROSS THE AREA. HOWEVER...BOUNDARIES FROM THIS STORM ALONG WITH DIURNAL HEATING HAS INITIATED NEW DISCRETE STRONG TO SEVERE STORMS THAT WILL CONTINUE THROUGH LATE AFTERNOON. BASED ON SATELLITE...RADAR...AND RAP TRENDS...THERE MAY BE A BREAK IN STORM ACTIVITY THIS EVENING AS THE NEW SEVERE STORMS CONTINUE TO DEVELOP AND MOVE NORTHEAST WELL WEST OF THE AREA. AFTER MIDNIGHT THE STORMS OUT WEST WILL EVOLVE UPSCALE INTO ANOTHER NOCTURNAL THUNDERSTORM COMPLEX THAT WILL SLOWLY MOVE INTO THE NORTHWEST THIRD OF THE AREA. ISOLATED TO SCATTERED STORMS ARE VERY POSSIBLE AHEAD OF THIS STORM COMPLEX AS MOISTURE CONTINUES TO FEED INTO THE AREA. ON MONDAY THE BETTER RAIN CHANCES WILL BE OVER THE NORTHWEST HALF OF THE AREA DURING THE MORNING. DURING THE AFTERNOON...NEW CONVECTION IS EXPECTED TO DEVELOP AS ANOTHER DISTURBANCE ALOFT MOVES THROUGH THE AREA. BASED ON THE POSITION OF THE MAIN FEATURES AND OVERALL EXPECTED FORCING...SEVERE STORMS ARE POSSIBLE. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 356 PM CDT SUN MAY 11 2014 MONDAY NIGHT THE MAIN COLD FRONT BEGINS MOVING THROUGH THE AREA. CONVECTION IS EXPECTED TO BE WIDESPREAD AND MAY EVOLVE INTO A BAND OF STRONG STORMS DURING THE EVENING HOURS. IF A BAND DOES FORM IT WILL SLOWLY MOVE EAST OVERNIGHT. ON TUESDAY...RAIN WILL END FROM WEST TO EAST DURING THE DAY WITH MOST OF THE AREA BEING DRY BY MID DAY. TEMPERATURES WILL BE WELL BELOW NORMAL. HIGH PRESSURE MOVING THROUGH THE MIDWEST TUESDAY NIGHT WILL RESULT IN DRY CONDITIONS WITH SEASONABLY COOL TEMPERATURES. ON WEDNESDAY THE NEXT STORM SYSTEM MOVES NORTHEAST FROM THE SOUTHERN PLAINS INTO THE OHIO VALLEY. THE TRENDS WITH THE MODELS HAVE BEEN TO SLOWLY PULL THE STORM SYSTEM TO THE NORTH AND WEST. WEDNESDAY NIGHT ON... THERE CONTINUES TO BE DIFFERENCES BETWEEN THE GLOBAL MODELS AS TO WHAT WILL OCCUR...BUT...ALL AGREE THAT TEMPERATURES WILL AVERAGE BELOW NORMAL WEDNESDAY NIGHT THROUGH SUNDAY. WEDNESDAY NIGHT/THURSDAY THE MODEL CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS AS THE NEXT SYSTEM MOVES UP THROUGH THE OHIO VALLEY. THE TREND IN THE MODELS HAS BEEN TO SLOWLY BRING THE STORM FURTHER TO THE NORTH AND WEST. THE MODEL CONSENSUS HAS MAINLY DRY CONDITIONS THURSDAY NIGHT AS THE STORM SYSTEM EXITS THE AREA. FRIDAY THROUGH SATURDAY THE MODEL CONSENSUS HAS MAINLY SLIGHT CHANCE POPS FRIDAY AND SATURDAY WITH MAINLY DRY CONDITIONS FRIDAY NIGHT. DISTURBANCES WILL CONTINUE TO ROTATE AROUND THE UPPER LOW OVER THE GREAT LAKES PRODUCING MAINLY DIURNAL SHOWERS. IF ENOUGH CLEARING CAN TAKE PLACE FRIDAY NIGHT AND WINDS REMAIN LIGHT...THERE MAY BE A POTENTIAL FOR FROST. DRY CONDITIONS SHOULD BE SEEN SATURDAY NIGHT AS HIGH PRESSURE MOVES THROUGH THE AREA. ON SUNDAY...THE MODEL CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS FOR ROUGHLY THE WESTERN HALF OF THE AREA AS THE NEXT STORM SYSTEM MOVES EAST FROM THE PLAINS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1133 PM CDT SUN MAY 11 2014 A LARGE...BUT PROGRESSIVELY MORE LOOSELY ORGANIZED COMPLEX OF STORMS WILL SPREAD EAST FROM CENTRAL IOWA INTO EASTERN IOWA AND NORTHWEST ILLINOIS THE REST OF TONIGHT. THIS MAY BRING SOME GUSTY WINDS...ESPECIALLY TO NORTHEAST IOWA. VFR CONDITIONS WILL DROP TO MVFR/HIGHER IFR AT TIMES IN ANY STORM. MONDAY WILL CONTINUE TO SEE A RISK FOR SHOWERS AND STORMS...MOST WIDESPREAD IN THE LATE AFTERNOON AND EVENING HOURS. AT THAT TIME...ANOTHER ROUND OF POTENTIAL MVFR/IFR IS LIKELY IN STORMS. WINDS WILL BE SOUTH TO SOUTHEAST AROUND 10 KTS THROUGH THE PERIOD. ERVIN && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...08 SYNOPSIS...08 SHORT TERM...08 LONG TERM...08 AVIATION...ERVIN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
630 PM CDT Tue May 13 2014 ...Updated aviation discussion... .UPDATE... ISSUED AT 224 PM CDT TUE MAY 13 2014 In areas of forecast lows from 33 to 36F, went with an NPW Frost Advisory tonight, same time as the Freeze Warning, 09Z-13Z. && .SHORT TERM...(This evening through Wednesday) ISSUED AT 106 PM CDT TUE MAY 13 2014 A large scale high pressure system over Utah and Wyoming will move just slightly southeast tonight, bringing decreasing winds and clear skies. There is a swath of mid-level clouds in the 080 range across Western Kansas this afternoon. With the suppression from the southeastward progressing surface high pressure, skies will become clear by midnight. Winds will decrease from the current breezy conditions to around 10 MPH by 00z, and then even lower to 06-07 MPH after midnight. For this reason, I lowered temperatures in the west to just below freezing, and posted another NPW Freeze Warning for the 09Z to 13Z time range, basically west of a Scott City to Hugoton line. The NAM and RUC models both support these sub-freezing temperatures out west. As for Wednesday, I made a few slight changes. There is an upper level trough dragging through, with better dynamics to our north. But, we could see a few sprinkles/virga Tuesday afternoon into Tuesday evening. Chose to go with scattered sprinkles since the only support for any precipitation will be from the upper trough crossing, with no significant lower level moisture, and only in our northern 1/3rd of the CWA. Wednesday should be slightly warmer than today, mainly based on the surface high pressure segmenting into two high pressure centers, one in the Wyoming and the other over Oklahoma. Surface winds Wednesday will start out light, then be from the northwest at 10 to 20 mph. This will not be a strong down slope affect, but enough to push maximum temperatures upward a couple to few degrees warmer than today. .LONG TERM...(Wednesday night through Tuesday) ISSUED AT 346 PM CDT TUE MAY 13 2014 A large upper level trough will develop over the upper midwest by Thursday night as northern and southern stream troughs progress eastward and merge together. Surface high pressure will generally be situated across the central plains on the back side of the trough. This will lead to fairly cool weather with highs in the 60s to near 70 Thursday. A few sprinkles are possible Thursday afternoon given the cold upper level temperatures, but low level moisture will be a limiting factor. A few showers are possible by Friday, particularly in far western Kansas given the lack of capping and where temperatures may reach the upper 70s. Saturday night still looks cool as surface high pressure builds into western Kansas. Lows could be cooler than currently forecasted, with some upper 30s possible along interstate 70. By Saturday and Sunday, the flow will become more westerly at mid and high levels, which will allow for lee troughing and some moisture return into western Kansas. There is a slight chance of showers and thunderstorms through this period, but no severe weather or heavy rainfall is expected. High temperatures should remain mainly in the 70s. An upper level trough will develop near the West Coast by Monday and then progress into the Rockies by Tuesday and Wednesday. Low level moisture will continue to increase so that surface based CAPE will be higher each day. Low level moisture return from the Gulf of Mexico is progged to be rather limited even early next week since the prior cold front late this week will have shunted the low level moisture into the tropics. So instead of high CAPE ahead of a dryline and along a weak frontal boundary, instability will be rather marginal. However, given the presence of boundaries and at least marginal to moderate CAPE values, thunderstorms cannot be ruled out through Wednesday. Temperatures will be warming early next week as well, with the warmest readings in far southwest Kansas in the 90s, and cooler 80s along interstate 70. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) ISSUED AT 630 PM CDT TUE MAY 13 2014 VFR skies and visibilities can be expected through this TAF period. Winds will be gusty for an hour or so at the beginning of the period before diminishing with sunset. Winds will regain a gusty character again by mid morning Wednesday. && .PRELIMINARY POINT TEMPS/POPS... DDC 37 66 39 69 / 0 0 0 20 GCK 33 65 38 69 / 0 10 10 20 EHA 31 65 39 72 / 0 0 0 10 LBL 34 67 39 71 / 0 0 0 10 HYS 34 67 40 65 / 0 10 10 20 P28 40 70 43 69 / 0 0 0 20 && .DDC WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING from 4 AM CDT /3 AM MDT/ to 8 AM CDT /7 AM MDT/ Wednesday FOR KSZ043-044-061>063-074-075-084. FROST ADVISORY from 4 AM to 8 AM CDT Wednesday FOR KSZ030-031- 045-046-064-076-077-085-086. && $$ UPDATE...Burke SHORT TERM...Burke LONG TERM...Finch AVIATION...Gerard
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
610 AM CDT Mon May 12 2014 ...Updated aviation discussion... .SHORT TERM...(Today and tonight) ISSUED AT 200 AM CDT MON MAY 12 2014 A few high based showers will be possible across west central and portions of southwest Kansas through late morning as the closed off upper level low to our west opens up while moving east into the Western High Plains today. Much colder air aloft surging southward into the region will increase lapse rates aloft supporting the potential for a few isolated showers. Otherwise, tranquil conditions are likely Monday afternoon through Monday night as drier air continues move down into the high plains of western Kansas. Much cooler temperatures are on the way today as colder air surges southward into western Kansas through the period. The NAM/GFS show the H85 isotherm slipping southward nosing into west central and the I-70 corridor with H85 temperatures near 5C closer to the Oklahoma border. With low level stratus lingering through at least mid day, look for highs struggling to reach the 50s(F) across west central and central Kansas near the I-70 corridor with the upper 50s(F) to near 60F in south central Kansas. .LONG TERM...(Tuesday through Sunday) ISSUED AT 246 AM CDT MON MAY 12 2014 An upper level trough will slowly move east across western Kansas late Tuesday and Wednesday. Mid level moisture under the cool upper low appears to increase late Wednesday as 700mb warm air advection develops ahead of a north to south oriented upper level jet located on the western side of this upper level trough. Precipitation chances still appear small mid week, however increasing clouds are expected which may limit how warm temperatures will be mid week. At this time will lean towards the latest guidance for highs on Wednesday with temperatures mainly in the mid to upper 60s. Lows Tuesday night may also be impacted and given the potential for increasing clouds from the west towards daybreak will favor lows several degrees warmer than what the latest guidance suggests across far western Kansas. On Thursday a cold front will move into northern Kansas as an upper level disturbance drops south of of Canada and crosses the northern Plains. Timing issues exist on when this boundary will move into western Kansas. Given these timing issues with the frontal passage will stay close to the latest CRExtendFcst_Init on Temperatures Thursday and Friday. In addition to some cooler air returning to portions of northern Kansas behind the cold front late week there will also be improving chances for precipitation, especially across northern central Kansas. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday morning) ISSUED AT 608 AM CDT MON MAY 12 2014 Model soundings indicating the depth of the low level moisture will decrease today as a surface ridge axis begins to build into western Kansas. Model soundings suggesting ceilings will improve to MVFR by 14z and VFR after 18z. HRRR also suggesting this trend as well. Gusty northwest winds of 20 to near 25 knots can be expected through at 00z Tuesday based on the mean mixed layer winds. After sunset winds will decrease to around 10 knots. && .PRELIMINARY POINT TEMPS/POPS... DDC 55 35 63 36 / 10 0 0 0 GCK 52 34 61 34 / 20 0 0 0 EHA 53 34 58 36 / 10 0 10 0 LBL 55 34 64 33 / 10 0 10 0 HYS 52 35 63 36 / 30 0 0 0 P28 62 40 65 39 / 20 0 10 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JJohnson LONG TERM...Burgert AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1215 AM CDT Mon May 12 2014 ...UPDATE TO AVIATION... .SYNOPSIS... ISSUED AT 1007 PM CDT SUN MAY 11 2014 Water vapor imagery and 00Z upper air analysis indicate a strong closed off upper level low shifting eastward across the Four Corners Region. A +70kt upper level jet is lifting northeast across western Kansas. Near the surface, a strong cold front extending from northeastern Kansas southwest into the Oklahoma panhandle, is pushing southeast across central Kansas. Much colder and drier air is spilling southward into western Kansas with surface dewpoints dropping mainly into the 40s(F) with a few 30s(F) out near the Colorado border. && .SHORT TERM...(This evening through Monday) ISSUED AT 254 PM CDT SUN MAY 11 2014 Abbreviated AFD due to ongoing warning operations. From my mesoscale discussion at 1:53 PM... (Convection already has developed by the same mesoscale assessments still applies) Special 18Z KDDC raob shows just a little bit of CIN remaining. Won`t be long before convection develops. Visible satellite imagery shows increasing cumulus along the dryline/front. HRRR indicates thunderstorms developing along the Highway 283 corridor in the 3-4 pm time range. Right moving Bunkers shows propagation vectors northeasterly at 45 kt. Initial threat will be large hail (up to 20! on the LHP using NAM thermodynamic and kinematic variables) and damaging outflow winds. There is an small window of tornadic opportunity between 7 and 9 pm as low level winds back across central/south central-Kansas but all the big wedge/strong tornadoes should remain across Nebraska/Iowa with just small spin ups/weak tornadoes in our area, if possible. Convection will depart the area tonight. Some light showers will be possible on the backside of the departing wave. It will be windy post frontal through tomorrow. Right now conditions look borderline for wind advisory criteria. .LONG TERM...(Monday night through Sunday) ISSUED AT 122 PM CDT SUN MAY 11 2014 An upper level longwave trough will be moving across the Plains on Tuesday but should be dry with the moisture pushed east of the area. Colder temperatures will accompany this trough with overnight lows on Monday night into the mid 30s and highs on Tuesday in the low to mid 60s. Strong northwest winds will mix down to the surface with winds of 15 to 30 mph and partly cloudy skies. For Wednesday into Thursday, dry northwesterly upper level flow will follow with highs slowly warming into the upper 60s and 70s. Wednesday morning may be the coldest morning with light winds and lows in the low to mid 30s. For Friday and Saturday, a few showers and thunderstorms may form as as some upper air disturbances in northwest flow aloft interact with increasing upslope moisture. Lows will be in the 40s and highs around 70 to 75. On Sunday, of next week, upper level ridging is forecast with dry and warmer temps around 80. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) ISSUED AT 1215 AM CDT MON MAY 12 2014 MVFR/IFR cigs will prevail at all TAF sites through early this afternoon as low level stratus developing behind the exiting cold front persists across central and southwest Kansas. The cigs will continue to lift through the afternoon with VFR returning by Monday evening. As for winds, surface high pressure across the Northern Rockies will build southeast into the Colorado Rockies today. As a result, northwesterly winds of around 15 to 30kt will persist through Monday afternoon. && .PRELIMINARY POINT TEMPS/POPS... DDC 35 63 37 69 / 0 0 0 0 GCK 34 62 37 68 / 0 0 0 0 EHA 34 61 35 68 / 0 10 0 0 LBL 34 62 36 70 / 0 10 0 0 HYS 35 63 38 69 / 0 0 0 0 P28 40 66 42 70 / 0 10 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY until 1 AM CDT /Midnight MDT/ early this morning FOR KSZ030-031-043>046-061>066-074>081-084>090. && $$ SYNOPSIS...JJohnson SHORT TERM...Sugden LONG TERM...Kruse AVIATION...JJohnson
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1053 PM EDT TUE MAY 13 2014 .UPDATE... ISSUED AT 1053 PM EDT TUE MAY 13 2014 THERE ARE STILL A FEW ECHOES SHOWING UP ON RADAR ACROSS EASTERN KENTUCKY...MAINLY WEST OF I-75. ANOTHER CLUSTER OF STORMS HAS FIRED UP ACROSS NORTH CENTRAL KENTUCKY...AS AN OUTFLOW BOUNDARY ALIGNED FROM FRANKFORT DOWN TO BOWLING GREEN GRADUALLY MOVES EAST. GIVEN THE PROXIMITY OF THE BOUNDARY AND THE LATEST HRRR SHOWING A FEW MORE POP UPS FROM TIME TO TIME OVERNIGHT...WILL LEAVE AN ISOLATED POP IN THE FORECAST THROUGH THE REST OF THE NIGHT. LOW TEMPERATURES STILL LOOK TO BOTTOM OUT IN THE LOW TO MID 60S ACROSS THE AREA...WITH AREAS OF DENSE FOG FORMING. UPDATE ISSUED AT 855 PM EDT TUE MAY 13 2014 CLUSTERS OF SHOWERS AND THUNDERSTORMS MOVED TO THE NORTH ACROSS THE AREA. SOME OF THESE REACHED SEVERE LIMITS...PRODUCING SMALL HAIL AND SOME WIND DAMAGE. THE LAST OF THE COLD POOL RAINS ARE GRADUALLY DOWN ACROSS NORTHEAST KENTUCKY...WITH A FEW MORE CELLS OCCURRING ACROSS FAR EASTERN KENTUCKY. EXPECT CONVECTION TO WIND DOWN THROUGH 10 PM. POCKETS OF HEAVIER RAINFALL AND LOWER DEW POINT DEPRESSIONS HEADING INTO THE EVENING WILL LIKELY LEAD TO SOME FOG DEVELOPMENT...SO HIGHLIGHTED THIS A BIT MORE IN THE FORECAST. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 345 PM EDT TUE MAY 13 2014 AS OF MID AFTERNOON...A RIDGE OF HIGH PRESSURE WAS CENTERED OFF THE SOUTHEAST US COAST WHILE A TROUGH WAS OVER THE PLAINS TO MS VALLEY REGION AND A RIDGE WAS LOCATED ALONG THE PACIFIC COAST. AT THE SFC...AN AREA OF LOW PRESSURE WAS OVER NW ONTARIO WITH A COLD FRONT EXTENDING SOUTH INTO THE LOWER OH VALLEY REGION. LOCALLY...CONVECTION AT THIS TIME IS PRIMARILY CONFINED TO AREAS CLOSER TO LAKE CUMBERLAND AND DOWN IN THE TN VALLEY...THOUGH ISOLATED CONVECTION WAS OCCURRING OUTSIDE OF THESE AREAS. OVER THE NEXT FEW HOURS...THE CONVECTION WILL CONTINUE TO MOVE NORTH NORTHEAST AND GRADUALLY EXIT THE LAKE CUMBERLAND AREA. HOWEVER...SOME OF THE CONVECTION...OR EVENTUAL OUTFLOWS MAY LEAD TO CONVECTION MOVING INTO OR DEVELOPING OVER THE VA BORDER AREA OF BELL...HARLAN AND LETCHER COUNTY AREA. ALSO...A BOUNDARY THAT CURRENTLY IS NEAR A SANDY HOOK TO JKL TO MIDDLESBORO AND THEN EAST INTO NORTHEAST TN BORDER CONTINUES TO MOVE TO THE NORTH AND EAST. THIS MAY ALSO BE A FOCUS FOR CONVECTION INTO THE EVENING. WITH THE REGION IN ADVANCE OF THE COLD FRONT AND IN THE WARM SECTOR SOME ISOLATED CONVECTION CANNOT BE RULED OUT OVERNIGHT...BUT ACTIVITY SHOULD BE MINIMAL FOR MOST OF...IF NOT THE ENTIRE NIGHT. MANY OF THE SHORT TERM MODELS HAVE CONVECTION POSSIBLY ENCROACHING ON THE AREA LATE TONIGHT AND OPTED FOR SOME SLIGHT CHANCE POPS LATE. ALSO...TONIGHT INTO WEDNESDAY...A SHORTWAVE THAT IS NOW WORKING INTO THE SOUTHERN PLAINS REGION WILL APPROACH THE MS AND TN VALLEY AND NEAR THE MID MS AND LOWER OH VALLEY BY WED EVENING. THIS WILL LEAD TO SFC LOW PRESSURE DEVELOPING ALONG THE BOUNDARY AND TRACK TOWARD THE OH...KY AND IN TRI STATE AREA BY 0Z THU. THIS LOW WILL TRACK TOWARD THE WESTERN END OF LAKE ERIE BY THE END OF THE PERIOD. THIS WILL GRADUALLY LEAD TO MORE FORCING FOR ASCENT AND MORE FOCUSED CONVECTION BY THE LAST 12 HOURS OF THE PERIOD. MODEL FORECAST SOUNDINGS ALSO INDICATE INSTABILITY WILL BE MODERATE AGAIN TOMORROW AFTERNOON AND EVENING AS THE MID LEVEL SHORTWAVE TROUGH APPROACHES AND SFC LOW DEVELOPS. THE FORECAST DEEP LAYER SHEAR IS ALSO FORECAST TO BE GREATER THAN TODAY...BUT ONLY MODEST TO MODERATE...ENOUGH FOR MORE ORGANIZATION...AND GREATER INTENSITY AND COVERAGE WHEN COMBINED WITH INSTABILITY SPC HAS PLACED THE WESTERN PART OF THE CWA IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS FOR WEDNESDAY...AND GUSTY WINDS WOULD APPEAR TO BE THE PRIMARY THREAT AND WITH FREEZING LEVELS ALSO GRADUALLY LOWERING WITH THE APPROACH OF THE MID LEVEL SHORTWAVE SOME HAIL MIGHT ALSO BE POSSIBLE. THIS IS ALREADY HIGHLIGHTED IN THE HWO. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 305 PM EDT TUE MAY 13 2014 THE MODELS WERE ONCE AGAIN IN GOOD AGREEMENT IN THE LONG TERM. THE CONSENSUS VIEW BETWEEN THE ECMWF AND GFS MODELS ARE FOR A LARGE AREA OF LOW PRESSURE TO MOVE ACROSS THE GREAT LAKES REGION AND EVENTUALLY INTO NEW ENGLAND. A SURFACE COLD FRONT TRAILING FROM THIS LOW WILL PROVIDE THE INITIAL TRIGGER FOR SHOWERS AND THUNDERSTORMS ON THURSDAY. MOISTURE FROM THE GULF OF MEXICO STREAMING NORTH AHEAD OF THE FRONT WILL PROVIDE THE FUEL FOR THIS PRECIPITATION. ONCE THE FRONT MOVES THROUGH THE AREA THURSDAY NIGHT...AN AREA OF LOW PRESSURE ALOFT WILL BEGIN TO INFLUENCE OUR AREA AS IT MOVES SLOWLY SOUTHEASTWARD OUT OF THE WESTERN GREAT LAKES REGION. THIS SYSTEM WILL HAVE VERY LIMITED MOISTURE TO WORK AND IS THEREFORE EXPECTED TO BRING ONLY ISOLATED RAIN SHOWERS TO THE EASTERN CONUS THROUGH SATURDAY NIGHT. A MUCH COOLER AND DRIER AIR MASS IS THEN EXPECTED TO SETTLE OVER THE REGION THROUGH THE FIRST OF NEXT WEEK...AS A LARGE AREA OF CANADIAN HIGH PRESSURE MOVES INTO PLACE. THIS MUCH COOLER AIR WILL LEAD TO WELL BELOW NORMAL TEMPERATURES THROUGHOUT THE PERIOD...WITH DAILY HIGHS IN THE 60S AND NIGHTLY LOWS IN THE 40S AREA WIDE. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 855 PM EDT TUE MAY 13 2014 THE MAIN CONCERN THROUGH THE NIGHT WILL BE FOG...AS POCKETS OF HEAVY RAINFALL OCCURRED EARLIER. AT SME...UPWARDS OF AN INCH OF RAIN FELL...SO CONDITIONS WILL LIKELY BE DETERIORATING TO LIFR OR WORSE THROUGH THE NIGHT...WITH MVFR TO IFR ELSEWHERE. ONCE THE FOG BURNS OFF...SHOWERS AND THUNDERSTORMS WILL BE DEVELOPING...MAINLY IN THE AFTERNOON. WINDS WILL REMAIN AT AROUND 5 KTS...GENERALLY OUT OF THE SOUTH. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEOGERIAN SHORT TERM...JP LONG TERM...AR AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
215 AM EDT MON MAY 12 2014 .UPDATE... ISSUED AT 215 AM EDT MON MAY 12 2014 A FEW SHOWERS HAVE DEVELOPED OVER THE NE PART OF THE FORECAST AREA. THE HRRR MODEL HAS THIS IN HAND...AND IS SHOWING THE PRECIP HEADING OUT TO THE EAST OVERNIGHT. HAVE UPDATED TO INCLUDE A SLIGHT CHANCE OF PRECIP IN THAT AREA FOR A SHORT TIME OVERNIGHT. UPDATE ISSUED AT 1109 PM EDT SUN MAY 11 2014 THE FORECAST REMAINS ON TRACK TONIGHT. SOME OF THE MORE SHELTERED VALLEYS HAVE DROPPED OFF INTO THE MID 60S...SO A FEW UPPER 50S STILL LOOK ACHIEVABLE. THICKER HIGH CLOUD BLOW OFF FROM EARLIER CONVECTION IS ALSO THINNING ACROSS THE NORTHERN HALF OF THE AREA...SO WILL MAINTAIN PARTLY CLOUDY SKIES NORTH AND MOSTLY CLEAR SKY CONDITIONS SOUTH...BESIDES A FEW PATCHES OF MID-LEVEL CLOUDS DEVELOPING FROM TIME TO TIME. FRESHENED UP THE HOURLY SKY COVER...TEMPERATURES...AND DEW POINTS ACCORDING TO THE LATEST TRENDS IN OBSERVATIONS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 301 PM EDT SUN MAY 11 2014 FAIRLY QUIET PATTERN IN STORE FOR EASTERN KENTUCKY THROUGH TUESDAY MORNING. A RIDGE OF HIGH PRESSURE SHOULD KEEP THINGS HIGH AND DRY OVERNIGHT INTO EARLY MONDAY MORNING. THE MODEL DATA IS ALL SUGGESTING THAT JUST ENOUGH INSTABILITY AND LOW LEVEL MOISTURE WILL BE AVAILABLE TO SPARK SHOWER AND THUNDERSTORMS ACROSS THE AREA...WITH THE AFTERNOON PEAK HEATING HOURS PREFERRED. THE LATEST MOS GUIDANCE AND MODEL TIME HEIGHTS AND SOUNDINGS ALSO SUGGEST THIS POSSIBILITY. WITH THE MODELS ALL SHOWING FAIRLY SIMILAR SOLUTIONS FOR THE AREA FROM LATE TONIGHT THROUGH TUESDAY MORNING...THE NAM12 SOLUTION SEEMED AS GOOD AS ANY FOR THIS GO ROUND. IN SPITE OF A GOOD DEAL OF SHOWER AND STORM ACTIVITY ONGOING ACROSS CENTRAL AND WESTERN KENTUCKY AND SOUTHERN INDIANA...IT APPEARS THAT IT WILL BE TOO DRY SHOWERS OR STORMS TO FORM ACROSS EASTERN KENTUCKY TODAY AND TONIGHT. THEREFORE...THE NEW FORECAST WILL FEATURE A DRY OVERNIGHT PERIOD...WITH ISOLATED SHOWERS AND STORMS BEGINNING TO FIRE UP BETWEEN 16 AND 17Z ON MONDAY. ONCE THE SUN BEGINS TO SET AND HEATING IS LOST...ANY EXISTING SHOWERS OR STORMS WILL DISSIPATE QUICKLY LATE TOMORROW AFTERNOON. MONDAY NIGHT AND TUESDAY LOOK TO BE WARM AND DRY AS HIGH PRESSURE BUILDS WESTWARD AND KEEPS PRECIPITATION PUSHED OFF TO OUR WEST. TEMPERATURES WILL BE WELL ABOVE NORMAL THE NEXT COUPLE OF DAYS...WITH TOMORROWS HIGHS TOPPING OUT IN THE MID 80S AND LOWS ON MAKING IT INTO THE UPPER 50S AND LOWER 60S THE NEXT TWO NIGHTS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 425 PM EDT SUN MAY 11 2014 THE PERIOD WILL BEGIN WITH AN UPPER LEVEL RIDGE CENTERED OFF THE SOUTHEAST UNITED STATES WITH RIDGING NORTH INTO THE CENTRAL APPALACHIANS. ANOTHER RIDGE IS EXPECTED TO BE IN PLACE ALONG THE WEST COAST WITH A TROUGH EXPENDING FROM CENTRAL CANADA SOUTH INTO THE PLAINS AND SOUTHERN ROCKIES. BY THE START OF THE PERIOD...THE ECMWF IS QUICKER MOVING A SHORTWAVE TROUGH NEAR THE US/CANADIAN BORDER EAST AS IT IS WITH A MORE SOUTHERN SHORTWAVE WORKING THROUGH THE ROCKIES. DOWNSTREAM OF THIS TROUGH THE ECMWF IS ALSO FURTHER WEST WITH THE TROUGH AXIS OVER THE EASTERN CONUS. THROUGH WED EVENING...THE TROUGH AXIS WILL GRADUALLY WORK EAST AND APPROACH THE MS VALLEY REGION AS THE AXIS OF THE RIDGE TO THE EAST MOVES OFF INTO THE ATLANTIC AND THE RIDGE AXIS MOVES ONTO THE US WEST COAST. AT THE SFC...A PARENT SFC LOW SHOULD TRACK WELL NORTH OF THE REGION INTO QUEBEC BY WED EVENING. THE TRAILING SFC COLD FRONT WILL ENTER THE COMMONWEALTH ON TUE AFTERNOON AND BEGIN TO BECOME STATIONARY AS IT NEAR THE MID AND UPPER OH VALLEY AND APPALACHIANS. A SFC WAVE IS PROGGED TO DEVELOP ALONG THE BOUNDARY TUE NIGHT AND TRACK INTO THE COMMONWEALTH BY WED EVENING. THE ECMWF CONTINUES TO BE DEEPER WITH THE INITIAL SOUTHERN ROCKIES SHORTWAVE AS IT MOVES TOWARD THE MID MS VALLEY REGION. THIS LEADS TO MODEL DIFFERENCES WITH A MORE WESTERN AND DEEPER SFC WAVE DEVELOPMENT TUE NIGHT INTO WED. THE SFC LOW SHOULD EVENTUALLY TRACK INTO THE GREAT LAKES REGION BY LATE WED NIGHT OR THU AND SEND THE COLD FRONT TO THE EAST OF THE REGION BY MIDDAY ON THU. DEEPER MOISTURE SHOULD ALSO DEPART TO THE EAST AT THAT TIME...BUT THE UPPER TROUGH AXIS WILL NOT WORK ACROSS THE AREA UNTIL FRIDAY. A WESTERN RIDGE AND EASTERN TROUGH IS EXPECTED TO START THE WEEKEND...WITH THE RIDGE AXIS WORKING INTO THE PLAINS BY THE END OF THE PERIOD AND AT THAT TIME...THE TROUGH AXIS SHOULD MOVE TOWARD THE EASTERN SEABOARD. CONVECTION CHANCES WILL SOMEWHAT DIURNALLY DRIVEN EARLY IN THE PERIOD...BUT AS THE SFC FRONT APPROACHES LATE TUE NIGHT AND WED MOISTURE WILL INCREASE AND A WEAK LEAD SHORTWAVE MAY APPROACH FROM THE SOUTHWEST. HOWEVER...AS THE MAIN SHORTWAVE APPROACHES AND THE SFC WAVE TRACKS THROUGH THE OH VALLEY LATER WED INTO THU AM...CONVECTION CHANCES WILL BE BEST. UNSETTLED WEATHER WILL STILL REMAIN POSSIBLE INTO THE START OF THE WEEKEND...BEFORE THE TROUGH AXIS MOVES TO THE EAST. TEMPERATURES WILL BEGIN THE PERIOD ABOVE NORMAL...BUT BELOW NORMAL TEMPERATURES...AVERAGE ABOUT 10 OR MORE DEGREES BELOW NORMAL ARE EXPECTED BEHIND THE FRONT...FROM THU INTO SUN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 215 AM EDT MON MAY 12 2014 A FEW SHOWERS WERE OCCURRING OVER THE NE PART OF THE FORECAST AREA AT THE START OF THE PERIOD. THEY SHOULD MOVE OUT BEFORE DAWN...AND PROVIDE LITTLE IN THE WAY OF CEILING/VISIBILITY RESTRICTIONS. HOWEVER...FOG WILL AFFECT THE DEEPER VALLEYS IN EASTERN KY WITH LOCALIZED VISIBILITY LESS THAN A MILE UNTIL SHORTLY PAST SUNRISE. THERE IS A POSSIBILITY OF SHOWERS POPPING UP DURING THE DAY ON MONDAY...AND A FEW THUNDERSTORMS CAN NOT BE RULED OUT. THE PROBABILITY AT ANY GIVEN LOCATION IS RATHER LOW...AND ONLY VCSH HAS BEEN USED IN TAFS. OUTSIDE OF HEAVIER SHOWERS...VFR IS ANTICIPATED THROUGH MOST OF THE DAY. WILL LOOK FOR ANY PRECIP TO DIE OUT TOWARD EVENING. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL/GEOGERIAN SHORT TERM...AR LONG TERM...JP AVIATION...HAL
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1156 PM CDT Sun May 11 2014 .UPDATE... Issued at 1155 PM CDT SUN MAY 11 2014 The AVIATION section has been updated for the 06Z TAF issuance. UPDATE Issued at 930 PM CDT SUN MAY 11 2014 The likelihood of lightning strikes has dropped low enough this evening that there will be no mention of them in the HWO or the gridded products overnight. Despite ridging in the mid levels, the tepid lower trop is such that a stray light rain shower cannot be ruled out overnight, however. && .SHORT TERM...(Tonight through Tuesday night) Issued at 317 PM CDT SUN MAY 11 2014 Pockets of surface-based instability continue to expand over the WFO PAH CWA this afternoon, aided by decent insolation and weak to moderate directional shear (25-35 knots) aloft (as evidenced by the anvil rain plumes oriented from northwest to southeast). The old cold pool has eroded over southeast IL and southwest IN from the morning convection, so distinct theta-e gradients are in place. Given the GOES Water Vapor imagery, the moisture gradient aloft implies a gradient in lapse rates as well, helping to enhance updrafts. (This is evidenced by the newly organized storms with hail in Southeast IL). The 12km RUC also suggests that the expended CAPE along and north of the implied surface warm frontal reflection arcing from northwest to southeast through southeast Illinois into northwest Kentucky. Further expenditure of CAPE through 01z suggests that the pool of convective instability should drop markedly. In addition, model heights are expected to rise this evening with a subtle change in balance takes place between the eastern U.S. ridge and the center of the sharpening trough over Western Nebraska. Expect that rain chances will be essentially nil over the entire WFO PAH CWA by midnight, as the warm frontal boundary moves well north of the area and shear decreases with time. As mentioned in yesterday`s discussion, channeled vorticity along the eastern limb of the trough near the inflection point between the trough/ridge circulation (cyclonic/anticyclonic flow) will aid in creating some lift in advance of an approaching moisture plume from the Gulf of Mexico around daybreak on Monday. This transition zone for convection will move slowly east through Monday afternoon, as the main trough actually sharpens and becomes slightly negatively tilted west of Iowa and Missouri Monday night into Tuesday morning. By 09z (4 am CDT) Tuesday morning, the cold front associated with this trough is expected to move into western sections of the WFO PAH Forecast area (Southwest IL/Southeast MO). By late evening Monday and into early Tuesday, the coverage of showers and thunderstorms should pick up significantly. It is at this time, that my concern for heavy rain potential will increase, with the potential for at least minor flooding by daybreak on Tuesday over parts of Southeast Missouri northeast to the Mississippi River. QPF values in excess of two inches would not be out of the question during that time period. The 12km NAM-WRF is actually suggesting a new closed circulation will develop at the based of the mean trough over the upper Midwest, somewhere near the OK/TX panhandles by Tuesday night, moving into southern Missouri by Wednesday evening. This is similar to what the ECMWF advertised in the Friday/Saturday model runs. This will lead to enhanced precipitation, both pre/post frontal as the frontal boundary remains fixed along the Interstate 57/55 corridor in Southern IL/Southeast Missouri. Most of the upright (thunderstorm) instability may be mixed out by Tuesday afternoon and night, but warm top (satellite reference) convection processes will likely take over increasing the effectiveness of the rainfall from Tuesday into Wednesday. There is still some question with respect to severe potential during this time period, but heavy rainfall still remains the dominant threat Tuesday into Wednesday. .LONG TERM...(Wednesday through Sunday) Issued at 417 PM CDT SUN MAY 11 2014 Confidence is fairly high concerning the general synoptic pattern in the Wed-Sun time frame. It is looking more and more like a high amplitude mid level trof will be carved out from southeast Canada southward all the way into the Ms River Valley by the Wed/Thu period. On east side of the trof, broad swly flow aloft will be evident. As a sfc low lifts ne along the spine of the Appalachians Wed, it appears showers will once again overspread most of the forecast area. Highest rain amounts will probably be over wrn KY and sw IN. Once the sfc low pulls off to the northeast Wed night, and the h50 trof axis moves east of the region, rain chcs should decrease considerably for much of the remainder of the extended. However, very low height fields and extensive daytime cloudiness behind the system will likely lead to an extended period of below normal temperatures. Highs are only expected to reach the 60s most locations Thu/Fri/Sat. && .AVIATION... Issued at 1155 PM CDT SUN MAY 11 2014 The latest guidance seems to be trending wetter for Monday, but figure with the entire area in the warm sector, diurnal convection will be very sparse in coverage. Kept the TAFs dry for the entire period. South southwest winds should gust 20-25kts for much of the day. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ UPDATE...DRS SHORT TERM...Smith LONG TERM...GM AVIATION...DRS
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
318 PM CDT MON MAY 12 2014 .DISCUSSION... SIGNIFICANT HEAVY RAINFALL EVENT IS IN ITS BEGINNING STAGES ACROSS CENTRAL AND N TX THIS AFTN PER REGIONAL MOSAIC RADAR IMAGERY. MODELS ARE IN GOOD AGREEMENT THAT THIS EVENT WILL CONTINUE TO UNFOLD AS THE FRONT PUSHES EWD INTO OUR REGION THIS EVENING/TONIGHT. THE HEAVIEST RAINFALL IS EXPECTED TO FALL DURING THE OVERNIGHT HOURS...BEFORE THE FRONT OUTRUNS THE UPPER LEVEL SUPPORT. TRAINING OF STORMS...ESPECIALLY OVER AREAS THAT HAVE SEEN SIGNIFICANT RAINFALL WITHIN THE LAST 7 DAYS WILL BRING THE THREAT OF FLASH FLOODING TO MUCH OF E TX/SE OK/SW AR. IT APPEARS THAT THIS THREAT MAY BEGIN EARLIER THAN ANTICIPATED...SO HAVE PUSHED THE START TIME OF THE FLASH FLOOD WATCH UP TO 7 PM THIS EVENING. THE HEAVIEST RAINFALL IS EXPECTED TO FALL DURING THE OVERNIGHT HOURS...BEFORE THE FRONT OUTRUNS THE UPPER LEVEL SUPPORT. LIFT WILL BECOME MORE ISENTROPIC AS WE LOSE THE SFC FORCING DURING THE DAY TUESDAY... WHICH WILL LIKELY RESULT IN DECREASING RAIN RATES. DESPITE THIS... A CONTINUING THREAT FOR FLASH FLOODING MAY BE SEEN DUE TO THE OVERNIGHT RAINS...AND THE WATCH MAY NEED TO BE EXTENDED INTO WEDNESDAY. MODELS CONTINUE TO BE IN RESPECTABLE AGREEMENT WITH REGARD TO QPF...PAINTING A WIDESPREAD 3-5 INCHES /WITH HIGHER ISOLD TOTALS LIKELY/ ACROSS THE WATCH AREA...TAPERING OFF SIGNIFICANTLY TO THE SE. RAIN IS EXPECTED TO FINALLY COME TO AN END WEDNESDAY AFTERNOON/NIGHT...AS THE BASE OF THE UPPER TROF MOVES OVERHEAD. UNSEASONABLY COOL TEMPERATURES ARE STILL EXPECTED TUESDAY THROUGH THURSDAY AS NW FLOW ALOFT AND A COOL AIRMASS LINGER OVER THE REGION. MODELS CONTINUE TO TOY WITH A BACK-DOOR COLD FRONT DROPPING INTO OUR EXTREME N DURING FRI/SAT...WITH POSSIBLY SOME LIGHT PRECIP OVER THE NRN HALF OF OUR REGION. BOTH THE GFS AND EURO STALL THE FRONT TO OUR N...SO TEMPS ARE EXPECTED TO GRADUALLY WARM THROUGH THE WEEKEND. /12/ && .PREV DISCUSSION... /ISSUED 1229 PM CDT MON MAY 12 2014/ AVIATION... OBSERVED SOUNDING THIS MORNING FROM SHV SHOWED A NEARLY SATURATED SOUNDING TO NEAR 10KFT AND STRONG LOW LEVEL WINDS IN EXCESS OF 30KTS IN THE LOWEST 5KFT. LATE MORNING/EARLY AFTERNOON HEATING AND A WEAKLY CAPPED ENVIRONMENT HAS RESULTED IN THE DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN AND AROUND THE TERMINALS THIS AFTERNOON. CURRENTLY CEILINGS RANGE FROM NEAR 3KFT TO NEAR 6KFT BUT EXPECT BRIEF MVFR CONDITIONS WITH BOTH CEILINGS AND VSBYS IF AND WHEN ANY CONVECTION MOVES OVER A TERMINAL LOCATION. A STRONG PRESSURE GRADIENT WILL KEEP SSE WINDS SUSTAINED NEAR 10-12KTS WITH HIGHER GUSTS THROUGH THE EARLY EVENING HOURS. LATEST HRRR PROGS SHOW THIS SCATTERED ACTIVITY CONTINUING THROUGH THE AFTERNOON WITH MORE OF A SOLID LINE OF CONVECTION MOVING EASTWARD FROM N CENTRAL TEXAS/CENTRAL OK LATER THIS EVENING ALONG AND AHEAD OF A STRONG COLD FRONT. HANDLED THE SCATTERED AFTERNOON CONVECTION WITH VCTS WITH TEMPO GROUPS BUT PREVAILED TSRA DURING THE EVENING AND OVERNIGHT HOURS ACROSS ALL BUT OUR EASTERN MOST TERMINAL LOCATIONS BASED ON THE HRRR PROGRESSION ON THE CONVECTIVE LINE. /13/ && .PRELIMINARY POINT TEMPS/POPS... SHV 67 72 56 67 48 / 90 70 60 60 10 MLU 68 82 62 70 48 / 30 60 50 60 10 DEQ 59 65 52 65 40 / 100 60 60 50 10 TXK 60 66 54 64 46 / 100 70 60 60 10 ELD 66 72 55 65 43 / 70 70 50 60 10 TYR 60 64 53 67 46 / 100 60 60 30 10 GGG 62 67 54 66 45 / 100 70 60 30 10 LFK 69 73 56 69 47 / 80 70 50 40 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH TUESDAY AFTERNOON FOR THE FOLLOWING ZONES: ARZ050-051-059>061-070>072. LA...FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH TUESDAY AFTERNOON FOR THE FOLLOWING ZONES: LAZ001>003. OK...FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH TUESDAY AFTERNOON FOR THE FOLLOWING ZONES: OKZ077. TX...FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH TUESDAY AFTERNOON FOR THE FOLLOWING ZONES: TXZ096-097-108>112-124>126-136>138-149>151. && $$ 12
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1229 PM CDT MON MAY 12 2014 .AVIATION... OBSERVED SOUNDING THIS MORNING FROM SHV SHOWED A NEARLY SATURATED SOUNDING TO NEAR 10KFT AND STRONG LOW LEVEL WINDS IN EXCESS OF 30KTS IN THE LOWEST 5KFT. LATE MORNING/EARLY AFTERNOON HEATING AND A WEAKLY CAPPED ENVIRONMENT HAS RESULTED IN THE DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN AND AROUND THE TERMINALS THIS AFTERNOON. CURRENTLY CEILINGS RANGE FROM NEAR 3KFT TO NEAR 6KFT BUT EXPECT BRIEF MVFR CONDITIONS WITH BOTH CEILINGS AND VSBYS IF AND WHEN ANY CONVECTION MOVES OVER A TERMINAL LOCATION. A STRONG PRESSURE GRADIENT WILL KEEP SSE WINDS SUSTAINED NEAR 10-12KTS WITH HIGHER GUSTS THROUGH THE EARLY EVENING HOURS. LATEST HRRR PROGS SHOW THIS SCATTERED ACTIVITY CONTINUING THROUGH THE AFTERNOON WITH MORE OF A SOLID LINE OF CONVECTION MOVING EASTWARD FROM N CENTRAL TEXAS/CENTRAL OK LATER THIS EVENING ALONG AND AHEAD OF A STRONG COLD FRONT. HANDLED THE SCATTERED AFTERNOON CONVECTION WITH VCTS WITH TEMPO GROUPS BUT PREVAILED TSRA DURING THE EVENING AND OVERNIGHT HOURS ACROSS ALL BUT OUR EASTERN MOST TERMINAL LOCATIONS BASED ON THE HRRR PROGRESSION ON THE CONVECTIVE LINE. && .PREV DISCUSSION... /ISSUED 1055 AM CDT MON MAY 12 2014/ DISCUSSION... WIDELY SCATTERED SHWRS/TSTMS ONGOING THIS MORNING...MOSTLY ASSOCIATED WITH A WEAK PIECE OF ENERGY /BARELY VISIBLE IN WV IMAGERY/ MOVING SEWD ACROSS E TX. SCATTERED CONVECTION WILL CONTINUE TO DEVELOP WITH HEATING...BEFORE THE BIG SHOW BEGINS LATE THIS AFTERNOON/EARLY THIS EVENING WITH THE APPROACH OF THE FRONT. THE FRONT IS CURRENTLY ALONG A ABILENE/WICHITA FALLS/STILLWATER LINE AND MAKING SIGNIFICANT EWD PROGRESS. THAT SAID...CURRENT TEMP/POP FCST IS ON-TRACK...SO NO CHANGES TO THESE MAJOR FCST ELEMENTS ARE EXPECTED. WIND-WISE...WIND SPEEDS ARE RUNNING SIGNIFICANTLY LOWER THAN PREVIOUSLY ANTICIPATED...AND WELL BELOW LAKE WIND ADVISORY CRITERIA. HAVE GONE AHEAD AND MADE THE NECESSARY ADJUSTMENTS TO THE WIND GRIDS AND DROPPED THE ADVISORY. /12/ && .PRELIMINARY POINT TEMPS/POPS... SHV 68 70 56 66 49 / 70 70 60 50 10 MLU 67 80 62 69 48 / 50 60 60 60 20 DEQ 59 65 52 64 41 / 90 60 50 60 10 TXK 60 66 54 65 47 / 90 70 60 60 10 ELD 66 72 55 65 44 / 70 70 60 60 20 TYR 61 65 51 65 47 / 90 60 60 30 10 GGG 62 67 53 66 47 / 90 70 60 50 10 LFK 69 75 57 69 49 / 70 70 60 50 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...FLASH FLOOD WATCH FROM 10 PM CDT THIS EVENING THROUGH TUESDAY AFTERNOON FOR THE FOLLOWING ZONES: ARZ050-051-059>061-070>072. LA...FLASH FLOOD WATCH FROM 10 PM CDT THIS EVENING THROUGH TUESDAY AFTERNOON FOR THE FOLLOWING ZONES: LAZ001>003. OK...FLASH FLOOD WATCH FROM 10 PM CDT THIS EVENING THROUGH TUESDAY AFTERNOON FOR THE FOLLOWING ZONES: OKZ077. TX...FLASH FLOOD WATCH FROM 10 PM CDT THIS EVENING THROUGH TUESDAY AFTERNOON FOR THE FOLLOWING ZONES: TXZ096-097-108>112-124>126-136>138-149>151. && $$ 13
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1135 PM CDT SUN MAY 11 2014 .AVIATION... FOR THE 12/06Z TAF ISSUE...EXPECT MVFR CIGS TO CONTINUE SPREADING NORTHWARD INTO EAST TEXAS AND WESTERN LOUISIANA. ISOLATED SHWRS AND TSTMS WILL ALSO BE ONGOING IN THE EAST TEXAS LAKES AREA AS WELL AS NORTH CENTRAL LOUISIANA. BY 09Z AND CONTINUING UNTIL 14Z...IFR CIGS BETWEEN 5 HUNDRED AND 1 KFT WILL BE COMMON ACROSS THE REGION. LIGHT FOG WILL ACCOMPANY THE LOWER CIGS AT A FEW TERMINALS WITH VSBYS BETWEEN 3 AND 5 MILES. VFR SHOULD RETURN TO MOST LOCATIONS BETWEEN 15Z AND 16Z...WITH CIGS 3 TO 4 KFT. ISOLATED TSTMS WILL DEVELOP WITH AFTERNOON HEATING...BECOMING MORE NUMEROUS FROM SE OK INTO E TX AFTER 21Z. SURFACE WIND SOUTH TO SOUTHEAST 10 TO 15 KTS TONIGHT AND INTO MONDAY WITH GUSTS 20 TO 25 KTS AFTER 14Z. /14/ && .PREV DISCUSSION... /ISSUED 1028 PM CDT SUN MAY 11 2014/ DISCUSSION... INTERESTING FORECAST UPDATE FOR THE REMAINDER OF THE OVERNIGHT HOURS. CONVECTION ACROSS NATCHITOCHES PARISH HAS FINALLY DISSIPATED BUT RENEWED CONVECTION CONTINUES TO DEVELOP ACROSS DEEP EAST TEXAS AND SHOWS SIGNS OF EXPANDING NORTH AND WEST. THIS WOULD MAKE SENSE AS LATEST RUN OF THE HRRR SUGGESTS INCREASING CAPE OVERNIGHT ACROSS OUR WESTERN HALF. CONVECTION IS PROBABLY BEING AIDED BY A 50KT LOW LEVEL JET OFF SHV`S WSR-88D VAD WIND PROFILER. A QUICK LOOK AT ISENTROPIC SFCS NEAR OR SLIGHTLY ABOVE THE 930MB LEVEL SUGGEST A CONTINUATION OF ISENTROPIC LIFT WITH LOW CONDENSATION PRESSURE DEFICITS ACROSS OUR WESTERN HALF AS WELL. HAVING SAID ALL THIS...FOR THE UPDATE...WILL CONTINUE WITH A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE REMAINDER OF THE NIGHT ACROSS ALL ZONES...EVEN THOUGH I`M A LITTLE MORE CERTAIN OF THE BEST COVERAGE BEING ACROSS OUR WESTERN ZONES WHERE THE INSTABILITY OVERNIGHT WILL BE GREATER. TEMPERATURES AS OF 03Z ARE RUNNING A LITTLE WARMER THAN THIS TIME AND GIVEN THE QUICK RETURN TO THE LOW LEVEL CLOUD COVER ALREADY SEEN ON IR IMAGERY ALONG AND SOUTH OF A LFK...SHV...MLU LINE...ANOTHER WARM NIGHT IS IN STORE ACROSS THE REGION. HOURLY TEMPS ARE ALMOST DEAD ON WITH FCST HOURLY TEMPS AND OVERNIGHT MINS ARE FORECAST TO BE SOME 2 TO 3 DEGREES WARMER THAN LAST NIGHT. FOR THAT REASON...TEMPS APPEAR TO BE IN PRETTY GOOD SHAPE. EXPECTING SOUTHEAST WINDS NEAR 10 TO 15 MPH AREAWIDE WITH AN OCCASIONAL GUST FROM TIME TO TIME GIVEN THE STRONG PRESSURE GRADIENT IN THE LOWER LEVELS. ONLY UPDATE NECESSARY APPEAR TO BE AN EXTENSION TO THE POP FORECAST SPATIALLY BUT OTHERWISE...NO OTHER CHANGES ARE NECESSARY. FCST UPDATE OUT SHORTLY...13. && .PRELIMINARY POINT TEMPS/POPS... SHV 73 86 67 79 57 / 20 50 60 70 50 MLU 70 86 67 83 60 / 20 50 50 60 50 DEQ 71 82 60 70 51 / 20 60 80 70 50 TXK 71 83 62 72 54 / 20 60 80 70 50 ELD 70 84 66 78 55 / 20 50 60 70 50 TYR 73 84 61 70 52 / 20 60 80 60 50 GGG 73 85 65 74 54 / 20 50 80 70 50 LFK 73 87 69 79 55 / 20 50 60 70 50 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1045 PM EDT TUE MAY 13 2014 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OFFSHORE THROUGH THE REST OF THE WEEK. A COLD FRONT EXTENDING FROM WISCONSIN TO TEXAS WILL TRACK SLOWLY EAST...MOVING INTO THE MID ATLANTIC STATES THURSDAY AND FRIDAY. HIGH PRESSURE IS EXPECTED TO RETURN TO THE MID ATLANTIC THIS WEEKEND. && .NEAR TERM /THROUGH WEDNESDAY/... BACKDOOR CDFNT SLIPPED THRU MOST OF CWFA LT TAFTN...COLLIDING W/ TRRN INDUCED TSRA INVOF HGR-OKV. THE RESULTANT COMPLEX OF TSRA MIGRATING SWD INTO THE WRN BURBS OF DC...AS WELL AS IN THE CENTRL FOOTHILLS OF VA. TSRA HV BEEN PULSE IN NATURE...SUPPORTING LARGE HAIL. TSRA IN AXIS OF MUCAPE 1500-2000 J/KG...W/ MINIMAL INHIBITION. /WE WERE UNABLE TO GET A RAOB OFF DUE TO TSRA./ RECENT RUNS OF THE HRRR HAS BEEN DOING A DECENT JOB AT MODELING STORMS...ALTHO LTST RUN /22 UTC/ NOT QUITE PICKING UP ON ACTIVITY IN CENTRL VA ATTM. GIVEN ELY FLOW ACROS MUCH OF CWFA AS WELL AS NOCTURNAL COOLING...THINK THAT 1...STORMS WL HV DIFFICULTY SPREADING MUCH FURTHER EAST AND 2...A GENERAL WEAKENING TREND WL BE OBSVD FOR THE REST OF THE EVNG. SINCE THAT WRITING...THE TSRA INVOF METRO DC HV WEAKENED...BUT A NEW AREA DVLPD INVOF EZF. AM STILL GOING W/ HRRR THEME...THINKING THAT TSRA SHUDNT LAST TOO MUCH BYD MIDNGT. HWVR...THE EVE TSRA ACTIVITY PLACES A BIG WRINKLE IN THE WAY OF OVNGT MARINE LYR FCST. TEMPS ACRS DE/NJ IN THE MID 50S ATTM. MEANWHILE...DCA STILL 73F. AT THIS STAGE...IT/LL BE QUITE CHALLENGING TO MAKE SUCH A BIG ADVECTIVE CHANGE. AM STILL KEEPING CLDS IN THE FCST...BUT HV RMVD DZ FOR ELY WED MRNG. TEMPS HV BEEN RAISED BY A CAT OR TWO AREAWIDE. THESE CHGS HV BEEN THE SMALLEST METRO BALT GIVEN HIGH DEGREE OF UNCERTAINTY. SHOWERS AND STORMS EXPECTED TO DEVELOP AGAIN DURING THE PEAK HEATING HRS ON WED. POPS HIGHEST IN CENTRAL SHENANDOAH VLY AND FOOTHILLS OF VA...WHERE CONVERGENCE AND INSTABILITY WILL BE GREATEST NEAR THE FRONT. STABLE MARINE LAYER WILL BE MORE STUBBORN TO MIX OUT FARTHER NORTH AND EAST. MAX TEMPS RANGE FROM LOW 70S IN NERN MD TO MID 80S IN CENTRAL VA. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... UPPER LEVEL TROUGHING WILL AMPLIFY OVER CENTRAL NORTH AMERICA THROUGH THE MIDDLE OF THE WEEK. THE ANOMALOUSLY FAR SOUTH EXTENT OF THIS TROF WILL ALLOW IT TO VERY EFFICIENTLY TAP INTO GULF MOISTURE. LOW PRESSURE WILL DEVELOP OVER THE GULF STATES AND RIDE NORTH ALONG THE UPSTREAM SIDE OF THE UPPER LEVEL TROF THROUGH THE DAY ON THURSDAY. LOCALLY...RELATIVELY COOL AND MOIST ONSHORE FLOW AROUND THE NORTH SIDE OF HIGH PRESSURE SITTING OFF OF THE CAROLINA COAST MAY PERSIST FOR THE NORTHEASTERN 1/4 TO 1/2 OF THE CWA INTO EARLY THURSDAY MORNING. THE NAM IN PARTICULAR HOLDS ONTO THIS ONSHORE FLOW LONGER THAN OTHER MODELS. OVER THE COURSE OF THE MORNING AND EARLY AFTERNOON THURSDAY EXPECT ANY REMAINING COOL AIR AT THE LOWER LEVELS TO MIX OUT AND SOUTHERLY FLOW TO DOMINATE. PRESSURE GRADIENT WILL TIGHTEN LOCALLY AS THE LOW MOVES NORTH THROUGH THE OHIO VALLEY AND GREAT LAKES AND HIGH PRESSURE REMAINS PARKED OFF THE NEW ENGLAND COAST THROUGH THE DAY ON THURSDAY. BREEZY SOUTHEAST WINDS WILL RAISE CONCERNS FOR MARINE HEADLINES AND COASTAL FLOOD HEADLINES...GIVEN THAT THEY WILL COINCIDE WITH HIGH TIDAL ANOMALIES...THROUGH THE END OF THE WORKWEEK. THE COLD FRONT WILL APPROACH THE AREA THURSDAY AFTERNOON...SLOWING CONSIDERABLY OVER THE APPALACHIAN MTNS. A STRONG LOW LEVEL JET AHEAD OF THE FRONT WILL EFFECTIVELY USHER MOISTURE INTO THE MID ATLANTIC THROUGH THE DAY THURSDAY. WITH PW VALUES BETWEEN ONE AND A HALF AND TWO INCHES OVER THE AREA FROM THURSDAY EVENING THROUGH FRIDAY MORNING AND MODERATE INSTABILITY AHEAD OF THE FRONT...PERSISTENT MODERATE TO HEAVY RAINS COULD LEAD TO FLOODING CONCERNS. A WAVE OF LOW PRESSURE WILL FORM ALONG THE STALLED FRONT EARLY FRIDAY MORNING AND RIDE UP ALONG THE EAST COAST THROUGH THE DAY ON FRIDAY. THOUGH THERE IS MINOR MODEL DISAGREEMENT ABOUT THE EXACT LOCATION OF THIS FRONT...THE EFFECTS OF THE WAVE ARE GENERALLY AGREED UPON. THE HEAVIEST RAIN SHOULD FALL AS THE WAVE PASSES LATE THURSDAY NIGHT AND FRIDAY MORNING. THUNDERSTORM COVERAGE WILL DEPEND UPON THE EXACT TRACK OF THE LOW. THE UPPER LEVEL TROF WILL BECOME MORE NEGATIVELY TILTED BY THIS TIME AND THE PASSAGE OF THE WAVE WILL USHER THE FRONT OFF OF THE COAST THROUGH THE DAY ON FRIDAY...WITH CHANCE POPS HANGING AROUND INTO THE EVENING MOSTLY ALONG AND EAST OF I95. HIGHS THURS WILL BE NEAR 80 E OF BLUE RIDGE AND MID 70S W. FRIDAY SHOULD BE ABOUT 10 DEG COOLER AS THE COLD FRONT WILL MOVE THROUGH LATE THURS NIGHT/FRI MORNING. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... SURFACE FRONT WILL BE CLEARING THE EASTERN ZONES/BAY FRIDAY EVENING ALTHOUGH FRONT ALOFT WILL STILL BE PUSHING EAST. SINCE TREND HAS BEEN FOR SLOWER PROGRESSION WITH THE FROPA...HAVE LINGERED POPS INTO THE FRIDAY EVENING HOURS ACCORDINGLY. LONG WAVE TROUGH OVER THE WESTERN GREAT LAKES OCCLUDES AND BECOME CLOSED UPPER LOW OVER THE EASTERN GREAT LAKE THROUGH THE WEEKEND. AS COLD POOL ALOFT MOVES OVERHEAD SATURDAY...DIURNALLY INDUCED INSTABILITY SCATTERED SHOWERS LOOK POSSIBLE...MAINLY ACROSS THE ELEVATED TERRAIN AS WEAK VORT MAX ROUND THE BASE OF THE LOW THERE. WILL LIKELY SEE AT LEAST GOOD CU FIELDS BOTH SATURDAY AND SUNDAY WITH RESIDUAL MOISTURE FROM RAINS AND SURFACE HEATING. MOUNTAIN AFTERNOON INSTABILITY SHOWERS WILL ALSO POSSIBLE AGAIN ON SUNDAY. TEMPERATURES WILL BE COMFORTABLE AND A BIT LOWER THAN NORMAL WITH THIS COOLER AND DRIER AIRMASS IN PLACE INTO MONDAY. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... TSRA INVOF MRB/IAD/CHO ABT OVER. VFR CONDS FOR THE REMINDER OF THE EVNG INTO THE OVNGT HRS. IFR CIGS WITH LOW CLOUDS POTENTIALLY WL MOVE IN OVNGT...BUT DETAILS UNCERTAIN GIVEN EVE TSRA ACTIVITY. WL ADVISE MIDSHIFT FCSTR TO ADDRESS THIS CLOSELY. CIGS GRADUALLY IMPROVE TO MVFR AND VFR FROM SW TO NE ACROSS THE TERMINALS BY MIDDAY WED. ADDITIONAL SHRA AND TSRA POSSIBLE IN VC OF CHO. IFR CONDITIONS MAY EXIST IN LOW CEILINGS...SHOWERS AND THUNDERSTORMS AHEAD OF A COLD FRONT THURSDAY AND FRIDAY. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR THE WEEKEND. A COUPLE OF UPPER LEVEL DISTURBANCES MAY BRING SCATTERED AFTERNOON SHOWERS. && .MARINE... STILL HV SCA CONDS AT TPLM2...BUT NO WHERE ELSE. MARINE AMS ACRS DELMARVA...WHILE SUMMER AMS W OF THE BAY. IF THE MARINE AIR ADVECTS WWD...IT/LL HV TO BE ACCOMPANIED BY A STIFF BREEZE. DONT THINK THAT WL HPPN...AND WL PLAN FOR A MIDNGT EXPIRATION. HWVR... WL ADVISE MIDSHIFT FCSTR. LGT ONSHORE WINDS LATE TNGT AND WED WITH HIPRES CONTINUING TO WEDGE DOWN INTO THE WATERS. A SMALL CRAFT ADVISORY MAY BE NECESSARY WEDNESDAY NIGHT AND WILL LIKELY BE NECESSARY THURSDAY INTO FRIDAY MORNING. GALE CRITERIA WILL BE APPROACHED FRIDAY AS A WAVE OF LOW PRESSURE PASSES CLOSE TO THE REGION. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR THE WEEKEND BEHIND A DEPARTING COLD FRONT. AFTERNOON SCATTERED SHOWERS WILL BE POSSIBLE THIS WEEKEND. && .TIDES/COASTAL FLOODING... TIDAL SITES CURRENTLY NEAR ASTRONOMICAL TIDE ALONG THE WRN SHORE OF THE CHSPK BAY AND TIDAL POTOMAC RIVER. POSITIVE TIDAL ANOMALIES ARE EXPECTED TO DEVELOP TUE NGT AND WED AS THE ARRIVAL OF A BACKDOOR COLD FRONT MARKS THE ONSET OF ONSHORE FLOW. MINOR COASTAL FLOODING MAY DEVELOP LATE IN THE WEEK WHEN THESE POSITIVE ANOMALIES INCREASE UNDER STRENGTHENING SLY FLOW AHEAD OF A SLOW- MOVING COLD FRONT. ASTRONOMICAL TIDES WILL ALREADY BE HIGH WITH A FULL MOON THIS WEEK. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ530>534- 537>543. && $$ SYNOPSIS...JRK NEAR TERM...HTS/JRK SHORT TERM...CEB LONG TERM...AEB AVIATION...HTS/JRK/CEB/AEB MARINE...HTS/JRK/CEB/AEB TIDES/COASTAL FLOODING...JRK
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
816 PM EDT TUE MAY 13 2014 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OFFSHORE THROUGH THE REST OF THE WEEK. A COLD FRONT EXTENDING FROM WISCONSIN TO TEXAS WILL TRACK SLOWLY EAST...MOVING INTO THE MID ATLANTIC STATES THURSDAY AND FRIDAY. HIGH PRESSURE IS EXPECTED TO RETURN TO THE MID ATLANTIC THIS WEEKEND. && .NEAR TERM /THROUGH WEDNESDAY/... BACKDOOR CDFNT SLIPPED THRU MOST OF CWFA LT TAFTN...COLLIDING W/ TRRN INDUCED TSRA INVOF HGR-OKV. THE RESULTANT COMPLEX OF TSRA MIGRATING SWD INTO THE WRN BURBS OF DC...AS WELL AS IN THE CENTRL FOOTHILLS OF VA. TSRA HV BEEN PULSE IN NATURE...SUPPORTING LARGE HAIL. TSRA IN AXIS OF MUCAPE 1500-2000 J/KG...W/ MINIMAL INHIBITION. /WE WERE UNABLE TO GET A RAOB OFF DUE TO TSRA./ OF GREATER IMMEDIATE CONCERN IS COPIOUS LIGHTNING. RECENT RUNS OF THE HRRR HAS BEEN DOING A DECENT JOB AT MODELING STORMS...ALTHO LTST RUN /22 UTC/ NOT QUITE PICKING UP ON ACTIVITY IN CENTRL VA ATTM. GIVEN ELY FLOW ACROS MUCH OF CWFA AS WELL AS NOCTURNAL COOLING...THINK THAT 1...STORMS WL HV DIFFICULTY SPREADING MUCH FURTHER EAST AND 2...A GENERAL WEAKENING TREND WL BE OBSVD FOR THE REST OF THE EVNG. HRRR SUGGESTS THAT THERE WL BE SHRA/TSRA INTHE SAME AREA THRU MIDNGT...WHICH SEEMS LIKE A GOOD BET FROM THIS VANTAGE POINT. STRATUS AND FOG EXPECTED TO DEVELOP LATE THIS EVE AND ESPECIALLY OVNGT EAST OF THE BLUE RIDGE AND IN NRN SHENANDOAH VLY WHERE MARINE LAYER BECOMES ESTABLISHED. ADDED PATCHY DRIZZLE ALONG THE CHSPK BAY AND DC METRO FOR LATE TNGT AND ERY WED MRNG. SHOWERS AND STORMS EXPECTED TO DEVELOP AGAIN DURING THE PEAK HEATING HRS ON WED. POPS HIGHEST IN CENTRAL SHENANDOAH VLY AND FOOTHILLS OF VA...WHERE CONVERGENCE AND INSTABILITY WILL BE GREATEST NEAR THE FRONT. STABLE MARINE LAYER WILL BE MORE STUBBORN TO MIX OUT FARTHER NORTH AND EAST. MAX TEMPS RANGE FROM LOW 70S IN NERN MD TO MID 80S IN CENTRAL VA. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... UPPER LEVEL TROUGHING WILL AMPLIFY OVER CENTRAL NORTH AMERICA THROUGH THE MIDDLE OF THE WEEK. THE ANOMALOUSLY FAR SOUTH EXTENT OF THIS TROF WILL ALLOW IT TO VERY EFFICIENTLY TAP INTO GULF MOISTURE. LOW PRESSURE WILL DEVELOP OVER THE GULF STATES AND RIDE NORTH ALONG THE UPSTREAM SIDE OF THE UPPER LEVEL TROF THROUGH THE DAY ON THURSDAY. LOCALLY...RELATIVELY COOL AND MOIST ONSHORE FLOW AROUND THE NORTH SIDE OF HIGH PRESSURE SITTING OFF OF THE CAROLINA COAST MAY PERSIST FOR THE NORTHEASTERN 1/4 TO 1/2 OF THE CWA INTO EARLY THURSDAY MORNING. THE NAM IN PARTICULAR HOLDS ONTO THIS ONSHORE FLOW LONGER THAN OTHER MODELS. OVER THE COURSE OF THE MORNING AND EARLY AFTERNOON THURSDAY EXPECT ANY REMAINING COOL AIR AT THE LOWER LEVELS TO MIX OUT AND SOUTHERLY FLOW TO DOMINATE. PRESSURE GRADIENT WILL TIGHTEN LOCALLY AS THE LOW MOVES NORTH THROUGH THE OHIO VALLEY AND GREAT LAKES AND HIGH PRESSURE REMAINS PARKED OFF THE NEW ENGLAND COAST THROUGH THE DAY ON THURSDAY. BREEZY SOUTHEAST WINDS WILL RAISE CONCERNS FOR MARINE HEADLINES AND COASTAL FLOOD HEADLINES...GIVEN THAT THEY WILL COINCIDE WITH HIGH TIDAL ANOMALIES...THROUGH THE END OF THE WORKWEEK. THE COLD FRONT WILL APPROACH THE AREA THURSDAY AFTERNOON...SLOWING CONSIDERABLY OVER THE APPALACHIAN MTNS. A STRONG LOW LEVEL JET AHEAD OF THE FRONT WILL EFFECTIVELY USHER MOISTURE INTO THE MID ATLANTIC THROUGH THE DAY THURSDAY. WITH PW VALUES BETWEEN ONE AND A HALF AND TWO INCHES OVER THE AREA FROM THURSDAY EVENING THROUGH FRIDAY MORNING AND MODERATE INSTABILITY AHEAD OF THE FRONT...PERSISTENT MODERATE TO HEAVY RAINS COULD LEAD TO FLOODING CONCERNS. A WAVE OF LOW PRESSURE WILL FORM ALONG THE STALLED FRONT EARLY FRIDAY MORNING AND RIDE UP ALONG THE EAST COAST THROUGH THE DAY ON FRIDAY. THOUGH THERE IS MINOR MODEL DISAGREEMENT ABOUT THE EXACT LOCATION OF THIS FRONT...THE EFFECTS OF THE WAVE ARE GENERALLY AGREED UPON. THE HEAVIEST RAIN SHOULD FALL AS THE WAVE PASSES LATE THURSDAY NIGHT AND FRIDAY MORNING. THUNDERSTORM COVERAGE WILL DEPEND UPON THE EXACT TRACK OF THE LOW. THE UPPER LEVEL TROF WILL BECOME MORE NEGATIVELY TILTED BY THIS TIME AND THE PASSAGE OF THE WAVE WILL USHER THE FRONT OFF OF THE COAST THROUGH THE DAY ON FRIDAY...WITH CHANCE POPS HANGING AROUND INTO THE EVENING MOSTLY ALONG AND EAST OF I95. HIGHS THURS WILL BE NEAR 80 E OF BLUE RIDGE AND MID 70S W. FRIDAY SHOULD BE ABOUT 10 DEG COOLER AS THE COLD FRONT WILL MOVE THROUGH LATE THURS NIGHT/FRI MORNING. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... SURFACE FRONT WILL BE CLEARING THE EASTERN ZONES/BAY FRIDAY EVENING ALTHOUGH FRONT ALOFT WILL STILL BE PUSHING EAST. SINCE TREND HAS BEEN FOR SLOWER PROGRESSION WITH THE FROPA...HAVE LINGERED POPS INTO THE FRIDAY EVENING HOURS ACCORDINGLY. LONG WAVE TROUGH OVER THE WESTERN GREAT LAKES OCCLUDES AND BECOME CLOSED UPPER LOW OVER THE EASTERN GREAT LAKE THROUGH THE WEEKEND. AS COLD POOL ALOFT MOVES OVERHEAD SATURDAY...DIURNALLY INDUCED INSTABILITY SCATTERED SHOWERS LOOK POSSIBLE...MAINLY ACROSS THE ELEVATED TERRAIN AS WEAK VORT MAX ROUND THE BASE OF THE LOW THERE. WILL LIKELY SEE AT LEAST GOOD CU FIELDS BOTH SATURDAY AND SUNDAY WITH RESIDUAL MOISTURE FROM RAINS AND SURFACE HEATING. MOUNTAIN AFTERNOON INSTABILITY SHOWERS WILL ALSO POSSIBLE AGAIN ON SUNDAY. TEMPERATURES WILL BE COMFORTABLE AND A BIT LOWER THAN NORMAL WITH THIS COOLER AND DRIER AIRMASS IN PLACE INTO MONDAY. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... TSRA INVOF MRB/IAD/CHO. RESTRICTIONS LOCALIZED MVFR/IFR. HV ACCOUNTED FOR THAT IN TAFS THRU EVE. WL AMD AS REQD. IFR CIGS WITH LOW CLOUDS LIKELY TO MOVE IN OVNGT...BUT TIMING A BIT MORE UNCERTAIN NOW GIVEN ONGOING TSRA ACTIVITY. HV KEPT PRVS TIMING...BETWEEN 03-06Z BWI/MTN AND POSSIBLY BETWEEN 07-10Z AT DCA/IAD/MRB. PATCHY FOG AND DRIZZLE ALSO POSSIBLE. CIGS GRADUALLY IMPROVE TO MVFR AND VFR FROM SW TO NE ACROSS THE TERMINALS BY MIDDAY WED. ADDITIONAL SHRA AND TSRA POSSIBLE IN VC OF CHO. IFR CONDITIONS MAY EXIST IN LOW CEILINGS...SHOWERS AND THUNDERSTORMS AHEAD OF A COLD FRONT THURSDAY AND FRIDAY. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR THE WEEKEND. A COUPLE OF UPPER LEVEL DISTURBANCES MAY BRING SCATTERED AFTERNOON SHOWERS. && .MARINE... ELY SURGE BHD CDFNT OVERSPREAD WATERS LT TAFTN. SCA CONDS VERIFIED...BUT THOSE CONDS NOW DIMINISHING. WL BE ABLE TO LET SCA DROP AOB PLANNED MIDNGT EXPIRATION. LGT ONSHORE WINDS LATE TNGT AND WED WITH HIPRES CONTINUING TO WEDGE DOWN INTO THE WATERS. A SMALL CRAFT ADVISORY MAY BE NECESSARY WEDNESDAY NIGHT AND WILL LIKELY BE NECESSARY THURSDAY INTO FRIDAY MORNING. GALE CRITERIA WILL BE APPROACHED FRIDAY AS A WAVE OF LOW PRESSURE PASSES CLOSE TO THE REGION. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR THE WEEKEND BEHIND A DEPARTING COLD FRONT. AFTERNOON SCATTERED SHOWERS WILL BE POSSIBLE THIS WEEKEND. && .TIDES/COASTAL FLOODING... TIDAL SITES CURRENTLY NEAR ASTRONOMICAL TIDE ALONG THE WRN SHORE OF THE CHSPK BAY AND TIDAL POTOMAC RIVER. POSITIVE TIDAL ANOMALIES ARE EXPECTED TO DEVELOP TUE NGT AND WED AS THE ARRIVAL OF A BACKDOOR COLD FRONT MARKS THE ONSET OF ONSHORE FLOW. MINOR COASTAL FLOODING MAY DEVELOP LATE IN THE WEEK WHEN THESE POSITIVE ANOMALIES INCREASE UNDER STRENGTHENING SLY FLOW AHEAD OF A SLOW- MOVING COLD FRONT. ASTRONOMICAL TIDES WILL ALREADY BE HIGH WITH A FULL MOON THIS WEEK. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ530>534- 537>543. && $$ SYNOPSIS...JRK NEAR TERM...HTS/JRK SHORT TERM...CEB LONG TERM...AEB AVIATION...HTS/JRK/CEB/AEB MARINE...HTS/JRK/CEB/AEB TIDES/COASTAL FLOODING...JRK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
820 PM EDT TUE MAY 13 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 353 PM EDT TUE MAY 13 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE TROF OVER CENTRAL NAMERICA BTWN RDGS ALONG THE W COAST AND ANOTHER STRETCHING FM QUEBEC THRU THE SE CONUS. THE INTERACTION BTWN A SHRTWV RIDING NNEWD IN THE STRONG SSW FLOW ALF TO THE E OF THE TROF AXIS AND RIBBON OF DEEPER MSTR REPRESENTED BY THE 12Z GRB RAOB RESULTED IN SOME SHRA OVER MAINLY THE ERN CWA INTO EARLY AFTN...BUT MID LVL DRYING UNDER THE JET SURGE OF PRIMARY SHRTWV LIFTING THRU NW ONTARIO IS BRINGING DRY WX TO THE ENTIRE CWA LATER THIS AFTN. HOWEVER...QUITE A BIT OF LOWER CLD IS LINGERING ESPECIALLY OVER THE WRN CWA WITH ABUNDANT LLVL MSTR BLO SHARPENING SUBSIDENCE INVRNS SHOWN ON THE 12Z INL/MPX RAOBS BEING ADVECTED TO THE E IN GUSTY SFC W FLOW TO THE S OF DEPARTING SFC LO IN NW ONTARIO. MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON LO CLD TRENDS/ IMPACT ON TEMPS. TNGT...DESPITE THE ABUNDANT LLVL MSTR...INCRSG ACYC NATURE OF THE LLVL FLOW WITH CLOSER APRCH OF SFC HI PRES IN THE CENTRAL PLAINS AND LOSS OF DAYTIME HEATING/MIXING SHOULD PROMOTE CLRG OF THE LO CLD. WITH LOSS OF DAYTIME HEATING AND WEAKENING PRES GRADIENT...THE GUSTY W WINDS WL DIMINISH THIS EVNG. UPSTREAM LO TEMPS THIS MRNG AND MOS FCSTS INDICATE MIN TEMPS WL DIP INTO THE 30S AS H85 TEMPS FALL TO BTWN 0 AND -2C BY 12Z WED. WED...SFC HI PRES RDG/LLVL ACYC FLOW WL RESULT IN LIGHTER WINDS/DRY WX AS PWAT FALLS TO 0.25-0.50 INCH. EXPECT SOME SC TO DVLP AWAY FM THE STABILIZING/COOLING INFLUENCE OF THE LKS WITH DAYTIME HEATING/ MIXING IN THE PRESENCE OF LINGERING CHILLY H85 TEMPS. THERE WL BE SOME INCRS IN HI CLDS OVER AT LEAST THE SE PORTION OF THE CWA AS ANOTHER SHRTWV RIDING NE OUT OF THE BASE OF DEEP TROF IN THE CENTRAL CONUS MOVES TOWARD THE GREAT LKS. DEEP MIXING TO H75 ON NAM/GFS FCST SDNGS YIELD MAX TEMPS RISING INTO THE MID/UPR 50S AWAY FM THE COOLING INFLUENCE OF THE LKS. ALTHOUGH THE DEEP MIXING WL ALLOW DEWPTS TO MIX OUT INTO THE LO-MID 20S/MIN RH TO FALL TOWARD 25 PCT... FAIRLY LGT WINDS/MOIST GROUND WL LIMIT ANY FIRE WX CONCERNS. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 445 PM EDT TUE MAY 13 2014 COOL TEMPERATURES WILL REMAIN THROUGH THE LONG TERM PERIOD...AS THE AREAS IS DOMINATED BY LOW PRESSURE AT 500MB. THE 500MB TROUGH CURRENTLY EXTENDING OVER MUCH OF CENTRAL CANADA AND THE CENTRAL UNITED STATES WILL SLIDE ACROSS ONTARIO AND MN BY 06Z THURSDAY. LOOK FOR A LOW TO DEVELOP OVER THE UPPER GREAT LAKES FROM AROUND 00Z FRIDAY THROUGH AT LEAST FRIDAY...AND THEN SHIFT OFF ACROSS LAKE HURON AND THE LOWER GREAT LAKES SATURDAY AFTERNOON THROUGH SUNDAY. ONE OF THE BIG QUESTIONS THIS PERIOD WAS THE POTENTIAL FOR MIXED PRECIP /RAIN OR SNOW SHOWERS/ FROM THURSDAY EVENING THROUGH SATURDAY MORNING. AN OVERALL DRIER SOLUTION HAS BEEN COMING IN WITH THE 12Z MODEL GUIDANCE. BY 12Z THURSDAY UPPER MI WILL BE IN BETWEEN THE LARGE HIGH PRESSURE OVER S CENTRAL CANADA AND THE N PLAINS...AND THE SFC LOW SURGING N ACROSS OH AND E MI. THE TRACK OF THE LOW IS FARTHEST W OFF THE CANADIAN AND ECMWF...WITH ALL SOLUTIONS KEEPING A WEAK TROUGH OVER CENTRAL AND E UPPER MI THURSDAY-THURSDAY NIGHT...WITH FAVORABLE COOL N-NW WINDS OFF LAKE SUPERIOR AND 850MB TEMPS FALLING TO AROUND -6C. THE WETTEST SOLUTION HAS BEEN THE 18Z NAM CAME IN WITH 0.25IN OF LIQUID OVER E UPPER MI /MAINLY E OF MUNISING/ FROM 18Z THURSDAY-00Z FRIDAY/. HAVE GONE AHEAD WITH A DRIER SCENARIO FOR NOW...BUT KEPT THE POTENTIAL FOR SLIGHT CHANCE RAIN/SNOW SHOWERS. WILL NEED TO WAIT AND SEE ON THIS ONE...AS A LOT CAN HAPPEN BETWEEN NOW AND THURSDAY AFTERNOON. LOOK FOR THE SFC LOW TO EXIT INTO SW QUEBEC THURSDAY NIGHT AS HIGH PRESSURE SLOWLY BUILDS ACROSS THE UPPER GREAT LAKES. LOOK FOR A RETURN TO NEAR NORMAL TEMPERATURES FOR THE END OF THE WEEKEND AND START OF THE NEXT WORK WEEK AS HIGH PRESSURE REMAINS OVERHEAD...AND THE 500MB RIDGE BUILDS IN FROM THE GULF OF MEXICO UP THROUGH THE UPPER GREAT LAKES. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 819 PM EDT TUE MAY 13 2014 VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD AS DRY HIGH PRES MOVES INTO THE REGION. WINDS WILL ALSO DIMINISH AS THE PRES GRADIENT WEAKENS THIS EVENING AND DAYTIME MIXING SUBSIDES. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 353 PM EDT TUE MAY 13 2014 EXPECT W WINDS UP TO 30 KKTS ON THE SOUTHERN FLANK OF LO PRES MOVING NEWD THRU ONTARIO...STRONGEST OVER THE NCENTRAL WHERE THE TERRAIN FUNNELS THIS FLOW BETWEEN THE KEWEENAW AND ISLE ROYALE...TO DIMINISH TO UNDER 20-25 KTS TONIGHT WITH THE ARRIVAL OF A WEAKER PRES GRADIENT CLOSER TO APPROACHING HI PRES. WINDS WILL THEN REMAIN UNDER 25 KTS THRU THE REST OF THE FORECAST PERIOD WITH A RELATIVELY WEAK PRES GRADIENT DOMINATING. THERE DOES REMAIN SOME POTENTIAL THAT N WINDS ON THU INTO FRI MAY REACH 25-30 KTS OVER MAINLY THE E HALF OF LAKE SUPERIOR IF A LO PRES SYSTEM LIFTING ACROSS THE GREAT LAKES TRACKS FARTHER TO THE W. THIS SCENARIO DOES NOT APPEAR LIKELY AT THIS TIME. && .HYDROLOGY... ISSUED AT 328 PM EDT TUE MAY 13 2014 THE NEXT CHANCE OF PRECIPITATION LOOKS TO FALL THURSDAY THROUGH FRIDAY. HOWEVER THE BEST CHANCE OF 0.10IN OR MORE WILL BE OVER THE E THIRD OF UPPER MI. SOME VERY LIGHT SNOW MAY EVEN BE POSSIBLE OVER THE W HALF THURSDAY NIGHT INTO FRIDAY. THE MAIN CONCERNS RIVER WISE WILL CONTINUE TO BE OVER THE W HALF OF UPPER MI. THEY INCLUDE THE STURGEON RIVER AT CHASSELL...WHICH IS SLOWLY FALLING...AND THE MICHIGAMME AT REPUBLIC...WITCH LAKE...AND CRYSTAL FALLS...WHICH LOOK TO HAVE ALL CRESTED AS WELL AND ARE SLOWLY ON THEIR WAY DOWN. RIVER FLOWS WILL LIKELY REMAIN HIGH THROUGH THE REST OF THE WEEK. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KF AVIATION...JLB MARINE...KC HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
421 PM EDT MON MAY 12 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 420 PM EDT MON MAY 12 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A DEEP MID LEVEL TROUGH FROM WRN MANITOBA INTO THE SRN ROCKIES RESULTING IN SW FLOW FROM THE SRN PLAINS INTO THE WRN GREAT LAKES. AT THE SFC... LOW PRES WAS LOCATED OVER WRN WI WITH A COLD FRONT TO THE SE THROUGH CNTRL IA AND A WARM FRONT INTO NRN WI. RADARS INDICATED THERE WAS A GAP IN THE PCPN OVER NRN WI AND UPPER MI AS ONE MCS SLIDES TO THE E INTO WRN LOWER MI AND ANOTHER LINE OF CONVECTION STRETCHED TO THE SW FROM ERN IA. WITH ABUNDANT LOW LEVEL MOISTURE OVER THE AREA...AREAS OF FOG HAD DEVELOPED ESPECIALLY IN AREAS WITH UPSLOPE ERLY FLOW. TONIGHT...AS SFC LOW PRES LIFTS FROM WRN WI ACROSS WRN LAKE SUPERIOR TONIGHT...THE WARM FRONT WILL ATTEMPT TO MOVE INTO UPPER MI. AT THIS POINT...IT APPEARS THE WARM FRONT MAY JUST SLIP INTO FAR SRN UPPER MI. SHRA/TSRA ARE EXPECTED TO DEVELOP BUT THE GREATEST COVERAGE IS EXPECTED FROM WI INTO FAR SRN UPPER MI...CLOSER TO THE HIGHER INSTABILITY AND MORE FAVORABLE LOW LEVEL INFLOW. WITH ELEVATED CAPE UP AROUND 1000J/KG AND DEEP LAYER SHEAR AROUND 30KT OR SO...STORMS WILL HAVE THE POTENTIAL TO BECOME ORGANIZED WITH ISOLD SVR POSSIBLE...MAINLY OVER FAR SCNTRL UPPER MI...CLOSER TO WARM FRONT. THE MAIN THREAT SHOULD BE HAIL...BUT WITH PWATS NEAR 1.5 INCH ...HEAVY RAINFALL WILL ALSO BE POSSIBLE. ADDITIONAL SHRA/TSRA MAY ALSO DEVELOP LATE TONIGHT ALONG THE COLD FRONT AS IT MOVES INTO THE W HALF BTWN 06Z-12Z. TUE...SHRA/TSRA WILL BE LIKELY IN THE MORNING OVER THE EAST HALF AS THE COLD FRONT MOVES THROUGH THE AREA. OTHERWISE...STRONG DRYING WILL MOVE INTO THE REST OF THE CWA. TEMPERATURES MAY CLIMB TO AROUND 60 BEFORE CAA STRENGTHENS IN THE AFTERNOON. GUSTY WEST WINDS WILL ALSO DEVELOP ESPECIALLY ACROSS THE HIGHER TERRAIN OF THE KEWEENAW. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 401 PM EDT MON MAY 12 2014 NAM SHOWS A CLOSED 500 MB LOW OVER EASTERN MANITOBA 00Z WED WITH A TROUGH OVER THE UPPER GREAT LAKES AND A RIDGE ON THE WEST COAST. THIS TROUGH DOES NOT MOVE MUCH THROUGH THU. NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE THROUGH THE PERIOD WITH THE STRONGEST CONVERGENCE OVER THE ERN CWA. MOISTURE STAYS LIMITED UNTIL THU AND WILL REMAIN DRY THROUGH WED NIGHT BEFORE MOISTURE MOVES IN. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH THIS FORECAST PERIOD AND DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST. IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE UPPER GREAT LAKES 12Z FRI WITH A RIDGE OVER THE WESTERN U.S. PATTERN CHANGES LITTLE 12Z SAT WITH THE RIDGE MOVING INTO THE PLAINS ON SUN AND THE TROUGH MOVING INTO THE LOWER GREAT LAKES. THE RIDGE MOVES INTO THE MISSISSIPPI RIVER VALLEY ON MON. TEMPERATURES LOOK TO STAY BELOW NORMAL THIS FORECAST PERIOD WITH A SLOW MODIFICATION TREND AND LOOKS WET THIS FORECAST PERIOD UNTIL SUN AND SUN NIGHT WHEN THE UPPER RIDGE MOVES IN. OTHERWISE...PCPN CHANCES WILL STAY LOW THROUGH THE PERIOD. HAVING SOME SNOW IN DURING THE LATE NIGHT AND EARLY MORNING HOURS THU NIGHT THROUGH SAT MORNING STILL LOOKS GOOD AS WELL WITH COLD ENOUGH TEMPERATURES TO NOT COMPLETELY RULE THIS POSSIBILITY OUT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 142 PM EDT MON MAY 12 2014 AFTER THE WIDESPREAD MODERATE RAINFALL...ABUNDANT LOW LEVEL MOISTURE WILL REMAIN ACROSS THE REGION THIS AFTERNOON EVEN THOUGH THERE WILL LITTLE ADDITIONAL RAIN. AS A RESULT...LIFR CONDITIONS WILL LINGER INTO THIS EVENING. SHRA WILL REDEVELOP TONIGHT WITH LIFR/IFR CONDITIONS PREVAILING. THERE COULD BE SOME TSRA AS WELL...PARTICULARLY AROUND KSAW...BUT LIMITED CONFIDENCE IN TIMING/COVERAGE OF TSRA PRECLUDES A MENTION IN THIS FCST. CONDITIONS WILL IMPROVE TO MVFR TUE MORNING WITH LOW LEVEL DRYING IN THE WAKE OF A COLD FRONT. WEST WINDS WILL ALSO BECOME GUSTY...ESPECIALLY AT CMX. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 420 PM EDT MON MAY 12 2014 NE GALES ACROSS WRN LAKE SUPERIOR LATE THIS AFTERNOON INTO THIS EVENING WILL DIMINISH OVERNIGHT AS LOW PRES LIFTS TOWARD THE AREA AND THE PRES GRADIENT WEAKENS. ONCE THE LOW MOVES NORTH OF THE LAKE TUE MORNING...STRONG WEST WINDS WILL DEVELOP. THE GUSTY WINDS WILL SLOWLY DIMINISHING BELOW 25 KTS BY WEDNESDAY MORNING. WINDS FOR THE REST OF THE WEEK WILL MAINLY BE BLO 20 KTS. HOWEVER...A LOW PRESSURE SYSTEM COULD IMPACT THE REGION LATE THIS WEEK WITH WINDS OVER 25 KTS THURSDAY INTO FRIDAY. UNCERTAINTY IS HIGH WITH THAT SYSTEM THOUGH...SO CURRENT FORECAST WILL ONLY CALL FOR NORTHWEST TO 20 KTS AT THIS TIME. && .HYDROLOGY... ISSUED AT 401 PM EDT MON MAY 12 2014 RAINFALL AMOUNTS FOR THIS WHOLE RAIN EVENT THROUGH TUE AFTERNOON MAY EXCEED ONE TO ONE AND A HALF INCHES OVER PORTIONS OF WESTERN UPR MICHIGAN. RAIN CHANCES DIMINISH FROM WEST TO EAST ON TUESDAY AS A FRONTAL BOUNDARY EXITS THE REGION. RAINFALL WILL ONLY ADD TO THE ONGOING SNOWMELT AND ALREADY HIGH FLOWS ON AREA RIVERS AND STREAMS. THE MICHIGAMME RIVER NEAR REPUBLIC AND WITCH LAKE...THE STURGEON RIVER AT CHASSELL AND ALSTON AND THE MICHIGAMME RIVER DOWNSTREAM OF THE WAY DAM TO THE EAST OF CRYSTAL FALLS ARE UNDER FLOOD WARNINGS. GIVEN THE RAINFALL THAT WILL OCCUR THE NEXT 24-36 HOURS...RIVER LEVELS WILL KEEP RISING AND ADJUSTMENTS WILL LIKELY BE NEEDED BASED ON LATEST TRENDS. ALL THIS WATER DUE TO THE SNOWMELT AND THE RAINFALL WILL TAKE A WHILE TO WORK THROUGH THE RIVERS...SO IT IS QUITE LIKELY THAT HIGHER RIVER FLOWS AND THE ASSOCIATED ADVISORIES AND WARNINGS ON AREA RIVERS WILL CONTINUE THROUGH LATE THIS WEEK...IF NOT INTO THIS WEEKEND. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL MIDNIGHT EDT /11 PM CDT/ TONIGHT FOR LSZ162. GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...07 AVIATION...JLB MARINE...JLB HYDROLOGY...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
402 PM EDT MON MAY 12 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 515 AM EDT MON MAY 12 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A BUILDING RIDGE ALONG THE W COAST OF NAMERICA WITH AMPLIFIED DOWNSTREAM TROF OVER THE ROCKIES. MAIN PIECE OF ENERGY IS IN THE BASE OF THE TROF OVER COLORADO. WAA/ISENTROPIC ASCENT DOWNSTREAM INTO THE UPPER LAKES IS SUPPORTING A LARGE AREA OF SHRA/TSRA LIFTING NE ACROSS MN/WI EARLY THIS MORNING. SHORTWAVE MOVING NE INTO WRN WI IS FURTHER AIDING THE PCPN. INSTABILITY HAS BEEN SLOW TO ADVANCE N PER SPC MESOANALYIS...SO WHILE SHRA ARE ADVANCING STEADILY N AND E...TSRA ARE LAGGING FARTHER AND FARTHER S WITHIN THE OVERALL SHRA AREA. HIGH RES MODEL GUIDANCE...PARTICULARLY THE HIGH RES RAPID REFRESH... HAS A DECENT HANDLE ON APPROACHING SHRA. UTILIZED RADAR TRENDS AND HIGH RES GUIDANCE TO SWING A PERIOD OF CATEGORICAL POPS ACROSS THE FCST AREA THIS MORNING. FORTUNATELY...PCPN AMOUNTS DON`T LOOK TO BE EXCESSIVE AS MAIN AREA OF TSRA WILL PASS BY TO THE S. STILL... EXPECT ROUGHLY 0.5 TO 0.75 INCHES WHICH WILL GIVE AREA RIVERS/STREAMS A BOOST IN FLOW. AS SUPPORTING SHORTWAVE MOVES NE OF THE AREA...MUCH OF THE AFTN MAY TURN DRY IN ITS WAKE. POPS WERE LOWERED INTO THE CHC/SCT CATEGORY...BUT BELIEVE MANY AREAS WILL PROBABLY SEE A GOOD PERIOD OF DRY WEATHER THIS AFTN. WITH PCPN AT A MINIMUM DURING THE AFTN...TEMPS WILL HAVE A CHANCE TO RESPOND...AT LEAST IN AREAS WHERE GENERAL EASTERLY FLOW IS NOT OFF THE GREAT LAKES. BUMPED TEMPS UP INTO THE UPPER 50S/LWR 60S ACROSS MUCH OF THE INTERIOR. HIGH RES RAPID REFRESH SHOWS TEMPS RISING TO AROUND 70F OVER THE INTERIOR W THIS AFTN...CERTAINLY POSSIBLE IF CLOUDS THIN OUT SUFFICIENTLY. AS SFC LOW PRES LIFTS FROM WRN WI ACROSS WRN LAKE SUPERIOR TONIGHT...WARM FRONT WILL ATTEMPT TO MOVE INTO UPPER MI. AT THIS POINT...IT APPEARS THE WARM FRONT MAY JUST SLIP INTO FAR SRN UPPER MI. ADDITIONAL SHRA/TSRA WILL LIKELY DEVELOP AS SFC LOW/WARM FRONT LIFT N...THOUGH PCPN COVERAGE PROBABLY WON`T BE AS WIDESPREAD AS WHAT WILL OCCUR THIS MORNING. WITH ELEVATED CAPE UP AROUND 1000J/KG AND DEEP LAYER SHEAR AROUND 30KT OR SO...STORMS WILL HAVE THE POTENTIAL TO BECOME ORGANIZED WITH ISOLD SVR POSSIBLE...MAINLY OVER FAR SCNTRL UPPER MI...CLOSER TO WARM FRONT. MAIN THREAT SHOULD BE HAIL...BUT WITH PRECIPITABLE WATER 200-250PCT OF NORMAL...HVY RAINFALL WILL BE A GOOD BET WITH ANY TSRA. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 401 PM EDT MON MAY 12 2014 NAM SHOWS A CLOSED 500 MB LOW OVER EASTERN MANITOBA 00Z WED WITH A TROUGH OVER THE UPPER GREAT LAKES AND A RIDGE ON THE WEST COAST. THIS TROUGH DOES NOT MOVE MUCH THROUGH THU. NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE THROUGH THE PERIOD WITH THE STRONGEST CONVERGENCE OVER THE ERN CWA. MOISTURE STAYS LIMITED UNTIL THU AND WILL REMAIN DRY THROUGH WED NIGHT BEFORE MOISTURE MOVES IN. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH THIS FORECAST PERIOD AND DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST. IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE UPPER GREAT LAKES 12Z FRI WITH A RIDGE OVER THE WESTERN U.S. PATTERN CHANGES LITTLE 12Z SAT WITH THE RIDGE MOVING INTO THE PLAINS ON SUN AND THE TROUGH MOVING INTO THE LOWER GREAT LAKES. THE RIDGE MOVES INTO THE MISSISSIPPI RIVER VALLEY ON MON. TEMPERATURES LOOK TO STAY BELOW NORMAL THIS FORECAST PERIOD WITH A SLOW MODIFICATION TREND AND LOOKS WET THIS FORECAST PERIOD UNTIL SUN AND SUN NIGHT WHEN THE UPPER RIDGE MOVES IN. OTHERWISE...PCPN CHANCES WILL STAY LOW THROUGH THE PERIOD. HAVING SOME SNOW IN DURING THE LATE NIGHT AND EARLY MORNING HOURS THU NIGHT THROUGH SAT MORNING STILL LOOKS GOOD AS WELL WITH COLD ENOUGH TEMPERATURES TO NOT COMPLETELY RULE THIS POSSIBILITY OUT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 142 PM EDT MON MAY 12 2014 AFTER THE WIDESPREAD MODERATE RAINFALL...ABUNDANT LOW LEVEL MOISTURE WILL REMAIN ACROSS THE REGION THIS AFTERNOON EVEN THOUGH THERE WILL LITTLE ADDITIONAL RAIN. AS A RESULT...LIFR CONDITIONS WILL LINGER INTO THIS EVENING. SHRA WILL REDEVELOP TONIGHT WITH LIFR/IFR CONDITIONS PREVAILING. THERE COULD BE SOME TSRA AS WELL...PARTICULARLY AROUND KSAW...BUT LIMITED CONFIDENCE IN TIMING/COVERAGE OF TSRA PRECLUDES A MENTION IN THIS FCST. CONDITIONS WILL IMPROVE TO MVFR TUE MORNING WITH LOW LEVEL DRYING IN THE WAKE OF A COLD FRONT. WEST WINDS WILL ALSO BECOME GUSTY...ESPECIALLY AT CMX. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 504 AM EDT MON MAY 12 2014 EXPECT PERIOD OF STRONGER WINDS OVER LAKE SUPERIOR. APPROACHING LOW PRESSURE SYSTEM RESULTS IN NORTHEAST WINDS INCREASING TO GALES BY AFTN OVER WEST HALF OF LK SUPERIOR. WINDS TO 30 KTS OVER REST OF LK SUPERIOR. STRONG WINDS DIMINISH BRIEFLY LATER THIS EVENING AND OVERNIGHT TONIGHT AS THE LOW SLIDES ACROSS WESTERN LK SUPERIOR. ONCE THE LOW MOVES NORTH OF THE LAKE ON TUESDAY MORNING...STRONG WEST WINDS KICK UP. EXPECT THESE STRONG WESTERLIES...PROBABLY REACHING GALES ON TUESDAY OVER NCNTRL LK SUPERIOR...TO SLOWLY FADE BLO 25 KTS BY WEDNESDAY MORNING. WINDS REST OF THE WEEK WILL MAINLY BE BLO 20 KTS. HOWEVER...A LOW PRESSURE SYSTEM COULD IMPACT THE REGION LATE THIS WEEK WITH WINDS OVER 25 KTS THURSDAY INTO FRIDAY. UNCERTAINTY IS HIGH WITH THAT SYSTEM THOUGH...SO CURRENT FORECAST WILL ONLY CALL FOR NORTHWEST TO 20 KTS AT THIS TIME. && .HYDROLOGY... ISSUED AT 401 PM EDT MON MAY 12 2014 RAINFALL AMOUNTS FOR THIS WHOLE RAIN EVENT THROUGH TUE AFTERNOON MAY EXCEED ONE TO ONE AND A HALF INCHES OVER PORTIONS OF WESTERN UPR MICHIGAN. RAIN CHANCES DIMINISH FROM WEST TO EAST ON TUESDAY AS A FRONTAL BOUNDARY EXITS THE REGION. RAINFALL WILL ONLY ADD TO THE ONGOING SNOWMELT AND ALREADY HIGH FLOWS ON AREA RIVERS AND STREAMS. THE MICHIGAMME RIVER NEAR REPUBLIC AND WITCH LAKE...THE STURGEON RIVER AT CHASSELL AND ALSTON AND THE MICHIGAMME RIVER DOWNSTREAM OF THE WAY DAM TO THE EAST OF CRYSTAL FALLS ARE UNDER FLOOD WARNINGS. GIVEN THE RAINFALL THAT WILL OCCUR THE NEXT 24-36 HOURS...RIVER LEVELS WILL KEEP RISING AND ADJUSTMENTS WILL LIKELY BE NEEDED BASED ON LATEST TRENDS. ALL THIS WATER DUE TO THE SNOWMELT AND THE RAINFALL WILL TAKE A WHILE TO WORK THROUGH THE RIVERS...SO IT IS QUITE LIKELY THAT HIGHER RIVER FLOWS AND THE ASSOCIATED ADVISORIES AND WARNINGS ON AREA RIVERS WILL CONTINUE THROUGH LATE THIS WEEK...IF NOT INTO THIS WEEKEND. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL MIDNIGHT EDT /11 PM CDT/ TONIGHT FOR LSZ162. GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...07 AVIATION...JLB MARINE...JLA HYDROLOGY...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
144 PM EDT MON MAY 12 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 515 AM EDT MON MAY 12 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A BUILDING RIDGE ALONG THE W COAST OF NAMERICA WITH AMPLIFIED DOWNSTREAM TROF OVER THE ROCKIES. MAIN PIECE OF ENERGY IS IN THE BASE OF THE TROF OVER COLORADO. WAA/ISENTROPIC ASCENT DOWNSTREAM INTO THE UPPER LAKES IS SUPPORTING A LARGE AREA OF SHRA/TSRA LIFTING NE ACROSS MN/WI EARLY THIS MORNING. SHORTWAVE MOVING NE INTO WRN WI IS FURTHER AIDING THE PCPN. INSTABILITY HAS BEEN SLOW TO ADVANCE N PER SPC MESOANALYIS...SO WHILE SHRA ARE ADVANCING STEADILY N AND E...TSRA ARE LAGGING FARTHER AND FARTHER S WITHIN THE OVERALL SHRA AREA. HIGH RES MODEL GUIDANCE...PARTICULARLY THE HIGH RES RAPID REFRESH... HAS A DECENT HANDLE ON APPROACHING SHRA. UTILIZED RADAR TRENDS AND HIGH RES GUIDANCE TO SWING A PERIOD OF CATEGORICAL POPS ACROSS THE FCST AREA THIS MORNING. FORTUNATELY...PCPN AMOUNTS DON`T LOOK TO BE EXCESSIVE AS MAIN AREA OF TSRA WILL PASS BY TO THE S. STILL... EXPECT ROUGHLY 0.5 TO 0.75 INCHES WHICH WILL GIVE AREA RIVERS/STREAMS A BOOST IN FLOW. AS SUPPORTING SHORTWAVE MOVES NE OF THE AREA...MUCH OF THE AFTN MAY TURN DRY IN ITS WAKE. POPS WERE LOWERED INTO THE CHC/SCT CATEGORY...BUT BELIEVE MANY AREAS WILL PROBABLY SEE A GOOD PERIOD OF DRY WEATHER THIS AFTN. WITH PCPN AT A MINIMUM DURING THE AFTN...TEMPS WILL HAVE A CHANCE TO RESPOND...AT LEAST IN AREAS WHERE GENERAL EASTERLY FLOW IS NOT OFF THE GREAT LAKES. BUMPED TEMPS UP INTO THE UPPER 50S/LWR 60S ACROSS MUCH OF THE INTERIOR. HIGH RES RAPID REFRESH SHOWS TEMPS RISING TO AROUND 70F OVER THE INTERIOR W THIS AFTN...CERTAINLY POSSIBLE IF CLOUDS THIN OUT SUFFICIENTLY. AS SFC LOW PRES LIFTS FROM WRN WI ACROSS WRN LAKE SUPERIOR TONIGHT...WARM FRONT WILL ATTEMPT TO MOVE INTO UPPER MI. AT THIS POINT...IT APPEARS THE WARM FRONT MAY JUST SLIP INTO FAR SRN UPPER MI. ADDITIONAL SHRA/TSRA WILL LIKELY DEVELOP AS SFC LOW/WARM FRONT LIFT N...THOUGH PCPN COVERAGE PROBABLY WON`T BE AS WIDESPREAD AS WHAT WILL OCCUR THIS MORNING. WITH ELEVATED CAPE UP AROUND 1000J/KG AND DEEP LAYER SHEAR AROUND 30KT OR SO...STORMS WILL HAVE THE POTENTIAL TO BECOME ORGANIZED WITH ISOLD SVR POSSIBLE...MAINLY OVER FAR SCNTRL UPPER MI...CLOSER TO WARM FRONT. MAIN THREAT SHOULD BE HAIL...BUT WITH PRECIPITABLE WATER 200-250PCT OF NORMAL...HVY RAINFALL WILL BE A GOOD BET WITH ANY TSRA. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 504 AM EDT MON MAY 12 2014 DEEP TROUGH FOR MAY AND REALLY ANYTIME OF THE YEAR STRETCHES FROM CENTRAL CANADA TO THE SOUTHERN PLAINS ON TUESDAY. SFC LOW CURRENTLY OVER THE CENTRAL PLAINS SHOULD BE JUST NORTHWEST OF LK SUPERIOR DAYBREAK ON TUESDAY. OCCLUDED FRONT WILL BE SLICING ACROSS CWA THROUGH MID MORNING...EXITING EASTERN CWA BY EARLY AFTN. SHOULD BE AT LEAST SCT SHRA/TSRA EXPECTED ALONG AND AHEAD OF FRONT AS HIGHER 1000-850MB THETA-E POOLS ALONG THE BOUNDARY. SHARP DRYING ENDS ANY RAIN QUICKLY OVER WEST HALF IN THE MORNING...BUT MAY SEE ISOLD SHRA/TSRA OVER FAR SOUTHEAST CWA AS WEAK LOW-LEVEL CONVERGENCE LINGERS AND AS ANOTHER WEAKER SHORTWAVE/Q-VECTOR CONVERGENCE AT H85-H5 LIFTS OVER FAR EAST CWA. ANY STORMS AHAEAD OF FRONT IN THE MORNING SHOULD BE WEAK AS 1-6KM MUCAPE AND MLCAPE BOTH DIMINISH STEADILY COMPARED TO THE OVERNIGHT HOURS. TEMPS WILL RISE INTO THE 60S OVER THE CNTRL WHERE WEST WINDS DOWNSLOPE...IMT-ESC-MNM...BUT WILL STAY IN THE 50S OVER THE WESTERN/NORTHWEST CWA WITH GRADIENT WINDS OFF LK SUPERIOR. THOSE WINDS COULD BE QUITE GUSTY...ESPECIALLY OVER THE MORE EXPOSED KEWEENAW...WHERE NAM/GFS SOUNDINGS INDICATE MIXED LAYER BUILDING TO H85-H8 WITH WINDS OVER 35 KTS IN THE MIXED LAYER. QUIET WEATHER TUESDAY NIGHT AND WEDNESDAY AS DEEP SFC LOW SLOWLY LIFTS TO JAMES BAY/HUDSON BAY. GRADIENT WEST FLOW STAYS OVER UPR MICHIGAN...BUT WILL LIGHTEN ENOUGH ON WEDNESDAY TO RESULT IN LAKE BREEZES. SLIM CHANCE THAT RESULTING LOW-LEVEL CONVERGENCE ADDED TO WEAK H7-H5 FORCING FM SHORTWAVE DROPPING ACROSS ON PERIFERY OF DEEP TROUGH ALOFT COULD TRIGGER A FEW SHOWERS/SPRINKLES INTERIOR CENTRAL. DEEP MIXING TO H8 WILL LIMIT POTENTIAL THOUGH AS LOW-LEVEL RH VALUES DROP OFF BLO 40 PCT. MAX TEMPS SHOULD PUSH INTO THE 50S INLAND AND FALL BACK INTO THE 40S NEAR LK SUPERIOR ONCE LAKE BREEZE DEVELOPS. THE FORECAST FOR THURSDAY INTO FRIDAY REMAINS UNCERTAIN. AT THE LEAST...TEMPS WILL BE BLO NORMAL FOR MOST CWA...PERHAPS BY MORE THAN 10-15F OVER THE NORTHERN CWA. ECMWF STILL SUPPORTS POTENTIAL FOR ACCUMULATING SNOW...NOW MAINLY DELAYED UNTIL THURSDAY NIGHT THROUGH FRIDAY AND POSSIBLY INTO FRIDAY NIGHT. LATEST UKMET ALSO IN LINE WITH THE ECMWF IDEA. MEANWHILE...GFS AND GEM-NH STAY WITH PROGRESSIVE IDEA INDICATING STRONG SHORTWAVE ROUNDING BASE OF DEEP TROUGH STAYS SEPARATE ENOUGH FROM TROUGH FROM HUDSON BAY TO THE NORTHERN PLAINS TO LIMIT PHASING. IF GFS THEME IDEA IS RIGHT...WOULD SEE SETUP WITH MORE DIURNALLY DRIVEN MAINLY RAIN SHOWERS DUE TO INSTABILITY ALOFT BENEATH THE TROUGH AXIS. IF THE ECMWF AND UKMET ARE ON THE RIGHT TRACK...THEY INDICATE ENOUGH PHASING BTWN THE LARGE SCALE TROUGHS TO DRAG A SFC LOW PRESSURE SYSTEM NORTHWARD OVER THE CNTRL GREAT LAKES INTO TOWARD THE UPPER GREAT LAKES THURSDAY INTO FRIDAY. WITH THAT SCNEARIO...WIDESPREAD RAIN AND SNOW THURSDAY EVENING WOULD CHANGE TO SNOW THURSDAY NIGHT INTO MUCH OF FRIDAY AND NORTHERLY FLOW WOULD ONLY BOOST THE SNOW OVER HIGHER TERRAIN AREAS NEAR LK SUPERIOR. SNOW COULD BE PRETTY WIDESRPEAD AS PYTPE WITH H85 TEMPS DROPPING BLO -5C AND SINCE 1000-850MB THICKNESSES FALL BLO 1300M. PHASING SYSTEMS ARE ALWAYS TOUGH TO FORECAST. ADD TO THAT FACT THAT WE ARE PUSHING INTO MIDDLE OF MAY AND IT MAKES IT REALLY TOUGH TO SAY IF UKMET AND ECMWF SOLUTION WILL WORK OUT AS FORECAST. SINCE ECMWF ENSEMBLE MEAN WOULD ALSO SUPPORT SIMILAR IDEA AND SOME CANADIAN ENSEMBLES HAVE SHOWN THIS RECENTLY IT DOES SUGGEST THE IDEA AT LEAST HAS SOME MERIT COMPARED TO JUST ONE ROUGE OPERATIONAL MODEL RUN SHOWING A BIG STORM IN THE FAR REACHES OF THE EXTENDED. ONCE THE SYSTEM OR JUST THE OPEN TROUGH MOVES BY...WEEKEND LOOKS DRIER WITH GRADUAL WARMING TREND. DID NOT STRAY FROM CONSENSUS LOW CHANCE POPS FOR NEXT WEEKEND ATTM. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 142 PM EDT MON MAY 12 2014 AFTER THE WIDESPREAD MODERATE RAINFALL...ABUNDANT LOW LEVEL MOISTURE WILL REMAIN ACROSS THE REGION THIS AFTERNOON EVEN THOUGH THERE WILL LITTLE ADDITIONAL RAIN. AS A RESULT...LIFR CONDITIONS WILL LINGER INTO THIS EVENING. SHRA WILL REDEVELOP TONIGHT WITH LIFR/IFR CONDITIONS PREVAILING. THERE COULD BE SOME TSRA AS WELL...PARTICULARLY AROUND KSAW...BUT LIMITED CONFIDENCE IN TIMING/COVERAGE OF TSRA PRECLUDES A MENTION IN THIS FCST. CONDITIONS WILL IMPROVE TO MVFR TUE MORNING WITH LOW LEVEL DRYING IN THE WAKE OF A COLD FRONT. WEST WINDS WILL ALSO BECOME GUSTY...ESPECIALLY AT CMX. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 504 AM EDT MON MAY 12 2014 EXPECT PERIOD OF STRONGER WINDS OVER LAKE SUPERIOR. APPROACHING LOW PRESSURE SYSTEM RESULTS IN NORTHEAST WINDS INCREASING TO GALES BY AFTN OVER WEST HALF OF LK SUPERIOR. WINDS TO 30 KTS OVER REST OF LK SUPERIOR. STRONG WINDS DIMINISH BRIEFLY LATER THIS EVENING AND OVERNIGHT TONIGHT AS THE LOW SLIDES ACROSS WESTERN LK SUPERIOR. ONCE THE LOW MOVES NORTH OF THE LAKE ON TUESDAY MORNING...STRONG WEST WINDS KICK UP. EXPECT THESE STRONG WESTERLIES...PROBABLY REACHING GALES ON TUESDAY OVER NCNTRL LK SUPERIOR...TO SLOWLY FADE BLO 25 KTS BY WEDNESDAY MORNING. WINDS REST OF THE WEEK WILL MAINLY BE BLO 20 KTS. HOWEVER...A LOW PRESSURE SYSTEM COULD IMPACT THE REGION LATE THIS WEEK WITH WINDS OVER 25 KTS THURSDAY INTO FRIDAY. UNCERTAINTY IS HIGH WITH THAT SYSTEM THOUGH...SO CURRENT FORECAST WILL ONLY CALL FOR NORTHWEST TO 20 KTS AT THIS TIME. && .HYDROLOGY... ISSUED AT 504 AM EDT MON MAY 12 2014 WIDESRPEAD MODERATE TO HEAVY RAIN WILL AFFECT ALL OF UPR MICHIGAN THROUGH EARLY THIS AFTN BEFORE DIMINISHING...THEN THERE MAY BE ANOTHER PERIOD OF MODERATE RAINFALL TONIGHT. RAINFALL AMOUNTS MAY EXCEED ONE INCH TODAY OVER PORTIONS OF WESTERN UPR MICHIGAN. RAIN CHANCES DIMINISH FROM WEST TO EAST ON TUESDAY AS A FRONTAL BOUNDARY EXITS THE REGION. RAINFALL WILL ONLY ADD TO THE ONGOING SNOWMELT AND ALREADY HIGH FLOWS ON AREA RIVERS AND STREAMS. THE PRIMARY CHANGE TO ONGOING HEADLINES WAS LAST EVENING...WHEN BASED ON EXPECTED RAINFALL...WHICH LOOKS LIKE IT IS WORKING OUT...ADVISORIES WERE UPGRADED TO WARNINGS FOR THE MICHIGAMME RIVER NEAR REPUBLIC AND WITCH LAKE. THE WARNING FOR THE STURGEON RIVER NEAR CHASSELL AND THE ADVISORY FOR THE STURGEON RIVER NEAR ALSTON CONTINUE...AS DOES THE ADVISORY FOR THE MICHIGAMME RIVER DOWNSTREAM OF WAY DAM...TO THE EAST OF CRYSTAL FALLS IN IRON COUNTY. GIVEN THE RAINFALL THAT WILL AFFECT THE AREA THE NEXT 24-36 HOURS...RIVER LEVELS WILL KEEP RISING AND ADJUSTMENTS WILL LIKELY BE NEEDED BASED ON LATEST TRENDS. ALL THIS WATER DUE TO THE SNOWMELT AND THE RAINFALL WILL TAKE A WHILE TO WORK THROUGH THE RIVERS...SO IT IS QUITE LIKELY THAT HIGHER RIVER FLOWS AND THE ASSOCIATED ADVISORIES AND WARNINGS ON AREA RIVERS WILL CONTINUE THROUGH LATE THIS WEEK...IF NOT INTO NEXT WEEKEND. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL MIDNIGHT EDT /11 PM CDT/ TONIGHT FOR LSZ162. GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...JLB MARINE...JLA HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
740 AM EDT MON MAY 12 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 515 AM EDT MON MAY 12 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A BUILDING RIDGE ALONG THE W COAST OF NAMERICA WITH AMPLIFIED DOWNSTREAM TROF OVER THE ROCKIES. MAIN PIECE OF ENERGY IS IN THE BASE OF THE TROF OVER COLORADO. WAA/ISENTROPIC ASCENT DOWNSTREAM INTO THE UPPER LAKES IS SUPPORTING A LARGE AREA OF SHRA/TSRA LIFTING NE ACROSS MN/WI EARLY THIS MORNING. SHORTWAVE MOVING NE INTO WRN WI IS FURTHER AIDING THE PCPN. INSTABILITY HAS BEEN SLOW TO ADVANCE N PER SPC MESOANALYIS...SO WHILE SHRA ARE ADVANCING STEADILY N AND E...TSRA ARE LAGGING FARTHER AND FARTHER S WITHIN THE OVERALL SHRA AREA. HIGH RES MODEL GUIDANCE...PARTICULARLY THE HIGH RES RAPID REFRESH... HAS A DECENT HANDLE ON APPROACHING SHRA. UTILIZED RADAR TRENDS AND HIGH RES GUIDANCE TO SWING A PERIOD OF CATEGORICAL POPS ACROSS THE FCST AREA THIS MORNING. FORTUNATELY...PCPN AMOUNTS DON`T LOOK TO BE EXCESSIVE AS MAIN AREA OF TSRA WILL PASS BY TO THE S. STILL... EXPECT ROUGHLY 0.5 TO 0.75 INCHES WHICH WILL GIVE AREA RIVERS/STREAMS A BOOST IN FLOW. AS SUPPORTING SHORTWAVE MOVES NE OF THE AREA...MUCH OF THE AFTN MAY TURN DRY IN ITS WAKE. POPS WERE LOWERED INTO THE CHC/SCT CATEGORY...BUT BELIEVE MANY AREAS WILL PROBABLY SEE A GOOD PERIOD OF DRY WEATHER THIS AFTN. WITH PCPN AT A MINIMUM DURING THE AFTN...TEMPS WILL HAVE A CHANCE TO RESPOND...AT LEAST IN AREAS WHERE GENERAL EASTERLY FLOW IS NOT OFF THE GREAT LAKES. BUMPED TEMPS UP INTO THE UPPER 50S/LWR 60S ACROSS MUCH OF THE INTERIOR. HIGH RES RAPID REFRESH SHOWS TEMPS RISING TO AROUND 70F OVER THE INTERIOR W THIS AFTN...CERTAINLY POSSIBLE IF CLOUDS THIN OUT SUFFICIENTLY. AS SFC LOW PRES LIFTS FROM WRN WI ACROSS WRN LAKE SUPERIOR TONIGHT...WARM FRONT WILL ATTEMPT TO MOVE INTO UPPER MI. AT THIS POINT...IT APPEARS THE WARM FRONT MAY JUST SLIP INTO FAR SRN UPPER MI. ADDITIONAL SHRA/TSRA WILL LIKELY DEVELOP AS SFC LOW/WARM FRONT LIFT N...THOUGH PCPN COVERAGE PROBABLY WON`T BE AS WIDESPREAD AS WHAT WILL OCCUR THIS MORNING. WITH ELEVATED CAPE UP AROUND 1000J/KG AND DEEP LAYER SHEAR AROUND 30KT OR SO...STORMS WILL HAVE THE POTENTIAL TO BECOME ORGANIZED WITH ISOLD SVR POSSIBLE...MAINLY OVER FAR SCNTRL UPPER MI...CLOSER TO WARM FRONT. MAIN THREAT SHOULD BE HAIL...BUT WITH PRECIPITABLE WATER 200-250PCT OF NORMAL...HVY RAINFALL WILL BE A GOOD BET WITH ANY TSRA. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 504 AM EDT MON MAY 12 2014 DEEP TROUGH FOR MAY AND REALLY ANYTIME OF THE YEAR STRETCHES FROM CENTRAL CANADA TO THE SOUTHERN PLAINS ON TUESDAY. SFC LOW CURRENTLY OVER THE CENTRAL PLAINS SHOULD BE JUST NORTHWEST OF LK SUPERIOR DAYBREAK ON TUESDAY. OCCLUDED FRONT WILL BE SLICING ACROSS CWA THROUGH MID MORNING...EXITING EASTERN CWA BY EARLY AFTN. SHOULD BE AT LEAST SCT SHRA/TSRA EXPECTED ALONG AND AHEAD OF FRONT AS HIGHER 1000-850MB THETA-E POOLS ALONG THE BOUNDARY. SHARP DRYING ENDS ANY RAIN QUICKLY OVER WEST HALF IN THE MORNING...BUT MAY SEE ISOLD SHRA/TSRA OVER FAR SOUTHEAST CWA AS WEAK LOW-LEVEL CONVERGENCE LINGERS AND AS ANOTHER WEAKER SHORTWAVE/Q-VECTOR CONVERGENCE AT H85-H5 LIFTS OVER FAR EAST CWA. ANY STORMS AHAEAD OF FRONT IN THE MORNING SHOULD BE WEAK AS 1-6KM MUCAPE AND MLCAPE BOTH DIMINISH STEADILY COMPARED TO THE OVERNIGHT HOURS. TEMPS WILL RISE INTO THE 60S OVER THE CNTRL WHERE WEST WINDS DOWNSLOPE...IMT-ESC-MNM...BUT WILL STAY IN THE 50S OVER THE WESTERN/NORTHWEST CWA WITH GRADIENT WINDS OFF LK SUPERIOR. THOSE WINDS COULD BE QUITE GUSTY...ESPECIALLY OVER THE MORE EXPOSED KEWEENAW...WHERE NAM/GFS SOUNDINGS INDICATE MIXED LAYER BUILDING TO H85-H8 WITH WINDS OVER 35 KTS IN THE MIXED LAYER. QUIET WEATHER TUESDAY NIGHT AND WEDNESDAY AS DEEP SFC LOW SLOWLY LIFTS TO JAMES BAY/HUDSON BAY. GRADIENT WEST FLOW STAYS OVER UPR MICHIGAN...BUT WILL LIGHTEN ENOUGH ON WEDNESDAY TO RESULT IN LAKE BREEZES. SLIM CHANCE THAT RESULTING LOW-LEVEL CONVERGENCE ADDED TO WEAK H7-H5 FORCING FM SHORTWAVE DROPPING ACROSS ON PERIFERY OF DEEP TROUGH ALOFT COULD TRIGGER A FEW SHOWERS/SPRINKLES INTERIOR CENTRAL. DEEP MIXING TO H8 WILL LIMIT POTENTIAL THOUGH AS LOW-LEVEL RH VALUES DROP OFF BLO 40 PCT. MAX TEMPS SHOULD PUSH INTO THE 50S INLAND AND FALL BACK INTO THE 40S NEAR LK SUPERIOR ONCE LAKE BREEZE DEVELOPS. THE FORECAST FOR THURSDAY INTO FRIDAY REMAINS UNCERTAIN. AT THE LEAST...TEMPS WILL BE BLO NORMAL FOR MOST CWA...PERHAPS BY MORE THAN 10-15F OVER THE NORTHERN CWA. ECMWF STILL SUPPORTS POTENTIAL FOR ACCUMULATING SNOW...NOW MAINLY DELAYED UNTIL THURSDAY NIGHT THROUGH FRIDAY AND POSSIBLY INTO FRIDAY NIGHT. LATEST UKMET ALSO IN LINE WITH THE ECMWF IDEA. MEANWHILE...GFS AND GEM-NH STAY WITH PROGRESSIVE IDEA INDICATING STRONG SHORTWAVE ROUNDING BASE OF DEEP TROUGH STAYS SEPARATE ENOUGH FROM TROUGH FROM HUDSON BAY TO THE NORTHERN PLAINS TO LIMIT PHASING. IF GFS THEME IDEA IS RIGHT...WOULD SEE SETUP WITH MORE DIURNALLY DRIVEN MAINLY RAIN SHOWERS DUE TO INSTABILITY ALOFT BENEATH THE TROUGH AXIS. IF THE ECMWF AND UKMET ARE ON THE RIGHT TRACK...THEY INDICATE ENOUGH PHASING BTWN THE LARGE SCALE TROUGHS TO DRAG A SFC LOW PRESSURE SYSTEM NORTHWARD OVER THE CNTRL GREAT LAKES INTO TOWARD THE UPPER GREAT LAKES THURSDAY INTO FRIDAY. WITH THAT SCNEARIO...WIDESPREAD RAIN AND SNOW THURSDAY EVENING WOULD CHANGE TO SNOW THURSDAY NIGHT INTO MUCH OF FRIDAY AND NORTHERLY FLOW WOULD ONLY BOOST THE SNOW OVER HIGHER TERRAIN AREAS NEAR LK SUPERIOR. SNOW COULD BE PRETTY WIDESRPEAD AS PYTPE WITH H85 TEMPS DROPPING BLO -5C AND SINCE 1000-850MB THICKNESSES FALL BLO 1300M. PHASING SYSTEMS ARE ALWAYS TOUGH TO FORECAST. ADD TO THAT FACT THAT WE ARE PUSHING INTO MIDDLE OF MAY AND IT MAKES IT REALLY TOUGH TO SAY IF UKMET AND ECMWF SOLUTION WILL WORK OUT AS FORECAST. SINCE ECMWF ENSEMBLE MEAN WOULD ALSO SUPPORT SIMILAR IDEA AND SOME CANADIAN ENSEMBLES HAVE SHOWN THIS RECENTLY IT DOES SUGGEST THE IDEA AT LEAST HAS SOME MERIT COMPARED TO JUST ONE ROUGE OPERATIONAL MODEL RUN SHOWING A BIG STORM IN THE FAR REACHES OF THE EXTENDED. ONCE THE SYSTEM OR JUST THE OPEN TROUGH MOVES BY...WEEKEND LOOKS DRIER WITH GRADUAL WARMING TREND. DID NOT STRAY FROM CONSENSUS LOW CHANCE POPS FOR NEXT WEEKEND ATTM. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 738 AM EDT MON MAY 12 2014 CHALLENGING FCST SHAPING OVER THE NEXT 24HRS AS LOW PRES AND WARM FRONT LIFT INTO THE UPPER GREAT LAKES. ONGOING SHRA WILL WORK TO MOISTEN THE LOW-LEVELS...AND EXPECT KIWD/KCMX/KSAW TO FALL TO MVFR THIS MORNING WITH SOME PERIODS OF IFR POSSIBLE. AS DISTURBANCE GENERATING THE MORNING SHRA EXITS TO THE NE...THERE MAY NOT BE ANY SHRA AT THE TERMINALS DURING THE AFTN HRS. WITH E UPSLOPE FLOW OFF CHILLY LAKE SUPERIOR...KCMX WILL PROBABLY SEE LIFR CONDITIONS DEVELOP. MAINTAINED MVFR CONDITIONS AT KIWD/KSAW. WITH MORE OF A DOWNSLOPE COMPONENT AT KIWD...EXPECT HIGHER CIGS THERE...AND ITS POSSIBLE THERE COULD BE SOME PERIODS OF VFR. ON THE OTHER HAND...UPSLOPE WIND AT KSAW COULD LEAD TO SOME PERIODS OF IFR. SHRA WILL REDEVELOP TONIGHT WITH LIFR/IFR CONDITIONS PREVAILING. COULD BE SOME TSRA AS WELL...PARTICULARLY AROUND KSAW...BUT LIMITED CONFIDENCE IN TIMING/COVERAGE OF TSRA PRECLUDES A MENTION IN THIS FCST. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 504 AM EDT MON MAY 12 2014 EXPECT PERIOD OF STRONGER WINDS OVER LAKE SUPERIOR. APPROACHING LOW PRESSURE SYSTEM RESULTS IN NORTHEAST WINDS INCREASING TO GALES BY AFTN OVER WEST HALF OF LK SUPERIOR. WINDS TO 30 KTS OVER REST OF LK SUPERIOR. STRONG WINDS DIMINISH BRIEFLY LATER THIS EVENING AND OVERNIGHT TONIGHT AS THE LOW SLIDES ACROSS WESTERN LK SUPERIOR. ONCE THE LOW MOVES NORTH OF THE LAKE ON TUESDAY MORNING...STRONG WEST WINDS KICK UP. EXPECT THESE STRONG WESTERLIES...PROBABLY REACHING GALES ON TUESDAY OVER NCNTRL LK SUPERIOR...TO SLOWLY FADE BLO 25 KTS BY WEDNESDAY MORNING. WINDS REST OF THE WEEK WILL MAINLY BE BLO 20 KTS. HOWEVER...A LOW PRESSURE SYSTEM COULD IMPACT THE REGION LATE THIS WEEK WITH WINDS OVER 25 KTS THURSDAY INTO FRIDAY. UNCERTAINTY IS HIGH WITH THAT SYSTEM THOUGH...SO CURRENT FORECAST WILL ONLY CALL FOR NORTHWEST TO 20 KTS AT THIS TIME. && .HYDROLOGY... ISSUED AT 504 AM EDT MON MAY 12 2014 WIDESRPEAD MODERATE TO HEAVY RAIN WILL AFFECT ALL OF UPR MICHIGAN THROUGH EARLY THIS AFTN BEFORE DIMINISHING...THEN THERE MAY BE ANOTHER PERIOD OF MODERATE RAINFALL TONIGHT. RAINFALL AMOUNTS MAY EXCEED ONE INCH TODAY OVER PORTIONS OF WESTERN UPR MICHIGAN. RAIN CHANCES DIMINISH FROM WEST TO EAST ON TUESDAY AS A FRONTAL BOUNDARY EXITS THE REGION. RAINFALL WILL ONLY ADD TO THE ONGOING SNOWMELT AND ALREADY HIGH FLOWS ON AREA RIVERS AND STREAMS. THE PRIMARY CHANGE TO ONGOING HEADLINES WAS LAST EVENING...WHEN BASED ON EXPECTED RAINFALL...WHICH LOOKS LIKE IT IS WORKING OUT...ADVISORIES WERE UPGRADED TO WARNINGS FOR THE MICHIGAMME RIVER NEAR REPUBLIC AND WITCH LAKE. THE WARNING FOR THE STURGEON RIVER NEAR CHASSELL AND THE ADVISORY FOR THE STURGEON RIVER NEAR ALSTON CONTINUE...AS DOES THE ADVISORY FOR THE MICHIGAMME RIVER DOWNSTREAM OF WAY DAM...TO THE EAST OF CRYSTAL FALLS IN IRON COUNTY. GIVEN THE RAINFALL THAT WILL AFFECT THE AREA THE NEXT 24-36 HOURS...RIVER LEVELS WILL KEEP RISING AND ADJUSTMENTS WILL LIKELY BE NEEDED BASED ON LATEST TRENDS. ALL THIS WATER DUE TO THE SNOWMELT AND THE RAINFALL WILL TAKE A WHILE TO WORK THROUGH THE RIVERS...SO IT IS QUITE LIKELY THAT HIGHER RIVER FLOWS AND THE ASSOCIATED ADVISORIES AND WARNINGS ON AREA RIVERS WILL CONTINUE THROUGH LATE THIS WEEK...IF NOT INTO NEXT WEEKEND. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL MIDNIGHT EDT /11 PM CDT/ TONIGHT FOR LSZ162. GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...ROLFSON MARINE...JLA HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
516 AM EDT MON MAY 12 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 515 AM EDT MON MAY 12 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A BUILDING RIDGE ALONG THE W COAST OF NAMERICA WITH AMPLIFIED DOWNSTREAM TROF OVER THE ROCKIES. MAIN PIECE OF ENERGY IS IN THE BASE OF THE TROF OVER COLORADO. WAA/ISENTROPIC ASCENT DOWNSTREAM INTO THE UPPER LAKES IS SUPPORTING A LARGE AREA OF SHRA/TSRA LIFTING NE ACROSS MN/WI EARLY THIS MORNING. SHORTWAVE MOVING NE INTO WRN WI IS FURTHER AIDING THE PCPN. INSTABILITY HAS BEEN SLOW TO ADVANCE N PER SPC MESOANALYIS...SO WHILE SHRA ARE ADVANCING STEADILY N AND E...TSRA ARE LAGGING FARTHER AND FARTHER S WITHIN THE OVERALL SHRA AREA. HIGH RES MODEL GUIDANCE...PARTICULARLY THE HIGH RES RAPID REFRESH... HAS A DECENT HANDLE ON APPROACHING SHRA. UTILIZED RADAR TRENDS AND HIGH RES GUIDANCE TO SWING A PERIOD OF CATEGORICAL POPS ACROSS THE FCST AREA THIS MORNING. FORTUNATELY...PCPN AMOUNTS DON`T LOOK TO BE EXCESSIVE AS MAIN AREA OF TSRA WILL PASS BY TO THE S. STILL... EXPECT ROUGHLY 0.5 TO 0.75 INCHES WHICH WILL GIVE AREA RIVERS/STREAMS A BOOST IN FLOW. AS SUPPORTING SHORTWAVE MOVES NE OF THE AREA...MUCH OF THE AFTN MAY TURN DRY IN ITS WAKE. POPS WERE LOWERED INTO THE CHC/SCT CATEGORY...BUT BELIEVE MANY AREAS WILL PROBABLY SEE A GOOD PERIOD OF DRY WEATHER THIS AFTN. WITH PCPN AT A MINIMUM DURING THE AFTN...TEMPS WILL HAVE A CHANCE TO RESPOND...AT LEAST IN AREAS WHERE GENERAL EASTERLY FLOW IS NOT OFF THE GREAT LAKES. BUMPED TEMPS UP INTO THE UPPER 50S/LWR 60S ACROSS MUCH OF THE INTERIOR. HIGH RES RAPID REFRESH SHOWS TEMPS RISING TO AROUND 70F OVER THE INTERIOR W THIS AFTN...CERTAINLY POSSIBLE IF CLOUDS THIN OUT SUFFICIENTLY. AS SFC LOW PRES LIFTS FROM WRN WI ACROSS WRN LAKE SUPERIOR TONIGHT...WARM FRONT WILL ATTEMPT TO MOVE INTO UPPER MI. AT THIS POINT...IT APPEARS THE WARM FRONT MAY JUST SLIP INTO FAR SRN UPPER MI. ADDITIONAL SHRA/TSRA WILL LIKELY DEVELOP AS SFC LOW/WARM FRONT LIFT N...THOUGH PCPN COVERAGE PROBABLY WON`T BE AS WIDESPREAD AS WHAT WILL OCCUR THIS MORNING. WITH ELEVATED CAPE UP AROUND 1000J/KG AND DEEP LAYER SHEAR AROUND 30KT OR SO...STORMS WILL HAVE THE POTENTIAL TO BECOME ORGANIZED WITH ISOLD SVR POSSIBLE...MAINLY OVER FAR SCNTRL UPPER MI...CLOSER TO WARM FRONT. MAIN THREAT SHOULD BE HAIL...BUT WITH PRECIPITABLE WATER 200-250PCT OF NORMAL...HVY RAINFALL WILL BE A GOOD BET WITH ANY TSRA. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 504 AM EDT MON MAY 12 2014 DEEP TROUGH FOR MAY AND REALLY ANYTIME OF THE YEAR STRETCHES FROM CENTRAL CANADA TO THE SOUTHERN PLAINS ON TUESDAY. SFC LOW CURRENTLY OVER THE CENTRAL PLAINS SHOULD BE JUST NORTHWEST OF LK SUPERIOR DAYBREAK ON TUESDAY. OCCLUDED FRONT WILL BE SLICING ACROSS CWA THROUGH MID MORNING...EXITING EASTERN CWA BY EARLY AFTN. SHOULD BE AT LEAST SCT SHRA/TSRA EXPECTED ALONG AND AHEAD OF FRONT AS HIGHER 1000-850MB THETA-E POOLS ALONG THE BOUNDARY. SHARP DRYING ENDS ANY RAIN QUICKLY OVER WEST HALF IN THE MORNING...BUT MAY SEE ISOLD SHRA/TSRA OVER FAR SOUTHEAST CWA AS WEAK LOW-LEVEL CONVERGENCE LINGERS AND AS ANOTHER WEAKER SHORTWAVE/Q-VECTOR CONVERGENCE AT H85-H5 LIFTS OVER FAR EAST CWA. ANY STORMS AHAEAD OF FRONT IN THE MORNING SHOULD BE WEAK AS 1-6KM MUCAPE AND MLCAPE BOTH DIMINISH STEADILY COMPARED TO THE OVERNIGHT HOURS. TEMPS WILL RISE INTO THE 60S OVER THE CNTRL WHERE WEST WINDS DOWNSLOPE...IMT-ESC-MNM...BUT WILL STAY IN THE 50S OVER THE WESTERN/NORTHWEST CWA WITH GRADIENT WINDS OFF LK SUPERIOR. THOSE WINDS COULD BE QUITE GUSTY...ESPECIALLY OVER THE MORE EXPOSED KEWEENAW...WHERE NAM/GFS SOUNDINGS INDICATE MIXED LAYER BUILDING TO H85-H8 WITH WINDS OVER 35 KTS IN THE MIXED LAYER. QUIET WEATHER TUESDAY NIGHT AND WEDNESDAY AS DEEP SFC LOW SLOWLY LIFTS TO JAMES BAY/HUDSON BAY. GRADIENT WEST FLOW STAYS OVER UPR MICHIGAN...BUT WILL LIGHTEN ENOUGH ON WEDNESDAY TO RESULT IN LAKE BREEZES. SLIM CHANCE THAT RESULTING LOW-LEVEL CONVERGENCE ADDED TO WEAK H7-H5 FORCING FM SHORTWAVE DROPPING ACROSS ON PERIFERY OF DEEP TROUGH ALOFT COULD TRIGGER A FEW SHOWERS/SPRINKLES INTERIOR CENTRAL. DEEP MIXING TO H8 WILL LIMIT POTENTIAL THOUGH AS LOW-LEVEL RH VALUES DROP OFF BLO 40 PCT. MAX TEMPS SHOULD PUSH INTO THE 50S INLAND AND FALL BACK INTO THE 40S NEAR LK SUPERIOR ONCE LAKE BREEZE DEVELOPS. THE FORECAST FOR THURSDAY INTO FRIDAY REMAINS UNCERTAIN. AT THE LEAST...TEMPS WILL BE BLO NORMAL FOR MOST CWA...PERHAPS BY MORE THAN 10-15F OVER THE NORTHERN CWA. ECMWF STILL SUPPORTS POTENTIAL FOR ACCUMULATING SNOW...NOW MAINLY DELAYED UNTIL THURSDAY NIGHT THROUGH FRIDAY AND POSSIBLY INTO FRIDAY NIGHT. LATEST UKMET ALSO IN LINE WITH THE ECMWF IDEA. MEANWHILE...GFS AND GEM-NH STAY WITH PROGRESSIVE IDEA INDICATING STRONG SHORTWAVE ROUNDING BASE OF DEEP TROUGH STAYS SEPARATE ENOUGH FROM TROUGH FROM HUDSON BAY TO THE NORTHERN PLAINS TO LIMIT PHASING. IF GFS THEME IDEA IS RIGHT...WOULD SEE SETUP WITH MORE DIURNALLY DRIVEN MAINLY RAIN SHOWERS DUE TO INSTABILITY ALOFT BENEATH THE TROUGH AXIS. IF THE ECMWF AND UKMET ARE ON THE RIGHT TRACK...THEY INDICATE ENOUGH PHASING BTWN THE LARGE SCALE TROUGHS TO DRAG A SFC LOW PRESSURE SYSTEM NORTHWARD OVER THE CNTRL GREAT LAKES INTO TOWARD THE UPPER GREAT LAKES THURSDAY INTO FRIDAY. WITH THAT SCNEARIO...WIDESPREAD RAIN AND SNOW THURSDAY EVENING WOULD CHANGE TO SNOW THURSDAY NIGHT INTO MUCH OF FRIDAY AND NORTHERLY FLOW WOULD ONLY BOOST THE SNOW OVER HIGHER TERRAIN AREAS NEAR LK SUPERIOR. SNOW COULD BE PRETTY WIDESRPEAD AS PYTPE WITH H85 TEMPS DROPPING BLO -5C AND SINCE 1000-850MB THICKNESSES FALL BLO 1300M. PHASING SYSTEMS ARE ALWAYS TOUGH TO FORECAST. ADD TO THAT FACT THAT WE ARE PUSHING INTO MIDDLE OF MAY AND IT MAKES IT REALLY TOUGH TO SAY IF UKMET AND ECMWF SOLUTION WILL WORK OUT AS FORECAST. SINCE ECMWF ENSEMBLE MEAN WOULD ALSO SUPPORT SIMILAR IDEA AND SOME CANADIAN ENSEMBLES HAVE SHOWN THIS RECENTLY IT DOES SUGGEST THE IDEA AT LEAST HAS SOME MERIT COMPARED TO JUST ONE ROUGE OPERATIONAL MODEL RUN SHOWING A BIG STORM IN THE FAR REACHES OF THE EXTENDED. ONCE THE SYSTEM OR JUST THE OPEN TROUGH MOVES BY...WEEKEND LOOKS DRIER WITH GRADUAL WARMING TREND. DID NOT STRAY FROM CONSENSUS LOW CHANCE POPS FOR NEXT WEEKEND ATTM. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 128 AM EDT MON MAY 12 2014 LINGERING DRY AIR AT THE LOW LEVELS WITH PREVAILING VFR CONDITIONS ARE EXPECTED TIL LATE IN THE NIGHT. A NORTHWARD MOVING LOW AND A WARM FRONT WILL SPREAD SHRA INTO UPPER MI...MAINLY AFT 09Z ALTHOUGH THERE IS STILL SOME UNCERTAINTY IN HOW FAST PCPN WILL DEVELOP. KIWD HAS THE BEST CHC OF CONDITIONS FALLING TO MVFR OVERNIGHT WITH THE ONSET OF RAIN. EXPECT ALL SITES TO QUICKLY FALL TO IFR OR LIFR IN LOWERING STRATUS BY 12Z OR SHORTLY THEREAFTER WITH CONTINUED SHOWERS AND ADVECTION OF HIGHER DEWPOINTS INTO THE AREA. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 504 AM EDT MON MAY 12 2014 EXPECT PERIOD OF STRONGER WINDS OVER LAKE SUPERIOR. APPROACHING LOW PRESSURE SYSTEM RESULTS IN NORTHEAST WINDS INCREASING TO GALES BY AFTN OVER WEST HALF OF LK SUPERIOR. WINDS TO 30 KTS OVER REST OF LK SUPERIOR. STRONG WINDS DIMINISH BRIEFLY LATER THIS EVENING AND OVERNIGHT TONIGHT AS THE LOW SLIDES ACROSS WESTERN LK SUPERIOR. ONCE THE LOW MOVES NORTH OF THE LAKE ON TUESDAY MORNING...STRONG WEST WINDS KICK UP. EXPECT THESE STRONG WESTERLIES...PROBABLY REACHING GALES ON TUESDAY OVER NCNTRL LK SUPERIOR...TO SLOWLY FADE BLO 25 KTS BY WEDNESDAY MORNING. WINDS REST OF THE WEEK WILL MAINLY BE BLO 20 KTS. HOWEVER...A LOW PRESSURE SYSTEM COULD IMPACT THE REGION LATE THIS WEEK WITH WINDS OVER 25 KTS THURSDAY INTO FRIDAY. UNCERTAINTY IS HIGH WITH THAT SYSTEM THOUGH...SO CURRENT FORECAST WILL ONLY CALL FOR NORTHWEST TO 20 KTS AT THIS TIME. && .HYDROLOGY... ISSUED AT 504 AM EDT MON MAY 12 2014 WIDESRPEAD MODERATE TO HEAVY RAIN WILL AFFECT ALL OF UPR MICHIGAN THROUGH EARLY THIS AFTN BEFORE DIMINISHING...THEN THERE MAY BE ANOTHER PERIOD OF MODERATE RAINFALL TONIGHT. RAINFALL AMOUNTS MAY EXCEED ONE INCH TODAY OVER PORTIONS OF WESTERN UPR MICHIGAN. RAIN CHANCES DIMINISH FROM WEST TO EAST ON TUESDAY AS A FRONTAL BOUNDARY EXITS THE REGION. RAINFALL WILL ONLY ADD TO THE ONGOING SNOWMELT AND ALREADY HIGH FLOWS ON AREA RIVERS AND STREAMS. THE PRIMARY CHANGE TO ONGOING HEADLINES WAS LAST EVENING...WHEN BASED ON EXPECTED RAINFALL...WHICH LOOKS LIKE IT IS WORKING OUT...ADVISORIES WERE UPGRADED TO WARNINGS FOR THE MICHIGAMME RIVER NEAR REPUBLIC AND WITCH LAKE. THE WARNING FOR THE STURGEON RIVER NEAR CHASSELL AND THE ADVISORY FOR THE STURGEON RIVER NEAR ALSTON CONTINUE...AS DOES THE ADVISORY FOR THE MICHIGAMME RIVER DOWNSTREAM OF WAY DAM...TO THE EAST OF CRYSTAL FALLS IN IRON COUNTY. GIVEN THE RAINFALL THAT WILL AFFECT THE AREA THE NEXT 24-36 HOURS...RIVER LEVELS WILL KEEP RISING AND ADJUSTMENTS WILL LIKELY BE NEEDED BASED ON LATEST TRENDS. ALL THIS WATER DUE TO THE SNOWMELT AND THE RAINFALL WILL TAKE A WHILE TO WORK THROUGH THE RIVERS...SO IT IS QUITE LIKELY THAT HIGHER RIVER FLOWS AND THE ASSOCIATED ADVISORIES AND WARNINGS ON AREA RIVERS WILL CONTINUE THROUGH LATE THIS WEEK...IF NOT INTO NEXT WEEKEND. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL MIDNIGHT EDT /11 PM CDT/ TONIGHT FOR LSZ162. GALE WARNING FROM 10 AM THIS MORNING TO 11 PM EDT THIS EVENING FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...JLB MARINE...JLA HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
505 AM EDT MON MAY 12 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 347 PM EDT SUN MAY 11 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW STRONG SHORTWAVE ENERGY ROUNDING BASE OF AMPLIFIED TROF OVER THE FOUR CORNERS REGION OF THE SW CONUS. MODELS SHOW THIS STRONG SHORTWAVE BEGINNING TO EJECT NE FROM WRN/CENTRAL PLAINS TONIGHT AS ITS ASSOC SFC LOW LIFTS NE THROUGH THE PLAINS. INCREASING MOISTURE AND ISENTROPIC ASCENT AHEAD OF THIS LOW PRES SYSTEM SHOULD SIGNAL THE BEGINNING OF A FAIRLY WET PERIOD FOR THE CWA STARTING LATE TONIGHT AND CONTINUING INTO EARLY TUESDAY. TONIGHT...AS THE STRONGER SHORTWAVE BEGINS TO EJECT OUT OF THE DEEPENING UPPER TROF THE SFC LOW PRES WILL IN TURN LIFT NE THRU THE PLAINS. THE EVENING SHOULD REMAIN DRY...AND PERHAPS CONTINUE INTO THE OVERNIGHT OVER THE NE HALF OF THE FCST AREA CLOSER TO DRY LOW-LEVEL NE TRAJECTORIES OUT OF SFC HIGH PRES IN ONTARIO. MOST OF THE MODELS SHOW INCREASING 850-700 MB MOISTURE TRANSPORT AND ADVECTION INTO THE AREA FM THE SOUTH BTWN 06-12Z ALONG WITH INCREASING 300-305K WAA/ISENTROPIC ASCENT AHEAD OF THE APPROACHING LOW PRES SYSTEM. MODELS ALSO INDICATE A SUBTLE SHORTWAVE WILL LIFT NE INTO THE UPPER MISSISSIPPI VALLEY LATE TONIGHT THAT WILL FURTHER AID THE DEVELOPMENT/SPREAD OF SHRA NE INTO UPPER MI DURING THE OVERNIGHT. NOT MUCH INSTABILITY IS NOTED PER 0-3KM MUCAPE OFF THE NAM/GFS. WITH A COUPLE HUNDRED J/KG AND SHOWALTER INDEX FALLING JUST BLO 0C OVER THE FAR SCNTRL LATE TONIGHT IN MOST MODEL GUIDANCE...WILL CONTINUE THE MENTION OF THUNDER IN THAT AREA LATE TONIGHT. MONDAY...WITH H85 WARM FRONT IN THE VICINITY...MODELS SHOW CONTINUED MOISTURE TRANSPORT/ADVECTION AT H85-H7 ACROSS THE FRONTAL BOUNDARY AS PWATS OVER OUR AREA RISE TO AROUND 1.5 INCHES OR WELL OVER 200 PCT OF NORMAL. SHORTWAVE/PV ANAMOLY EMERGING NORTHEAST OUT OF THE WESTERN CONUS TROUGH WILL SPREAD AREA OF H85-H5 Q-VECTOR CONVERGENCE INTO THE UPPER GREAT LAKES BY MONDAY AFTERNOON. DESPITE THESE FAVORABLE FACTORS FOR SHOWERS...MODELS STILL DIFFER SOMEWHAT ON PLACEMENT OF MAXIMUM MOISTURE ADVECTION...WITH THE GFS AND NAM INDICATING BEST MOISTURE ADVECTION WEST AND THE REG GEM TO THE EAST. HOWEVER CORFIDI VECTORS...BOTH FORWARD AND BACKWARD PROPAGATING...ARE GENERALLY ORIENTED FROM WEST TO EAST ACROSS THE FCST AREA WHICH WOULD ARGUE SHOWERS MAKING IT INTO THE WRN FCST AREA SHOULD ADVECT INTO THE ERN COUNTIES AS WELL. GOING FCST LIKELY POPS STILL SEEM REASONABLE CONSIDERING THE H85 FRONT IS IN THE VICINTY. WILL CONTINUE IDEA OF LIKELY POPS WEST IN THE MORNING SPREADING EAST INTO THE AFTERNOON HRS. ALSO WILL CONTINUE TO KEEP MENTION OF TSRA MAINLY OVER SOUTH HALF INTO THE WESTERN CWA ALONG NORTHERN GRADIENT OF ELEVATED INSTABILITY WITH SEVERAL HUNDRED J/KG OF ELEVATED CAPE AND NEG SHOWALTER INDICES. BIGGEST THREAT WITH ANY TSRA WILL BE HEAVY RAIN GIVEN HIGH PWATS ACROSS AREA. ANY HEAVY RAIN OVER THE WRN COUNTIES WILL CONTINUE TO ADD MORE RUNOFF TO RIVERS ALREADY RUNNING NEAR BANKFULL...ESPECIALLY THE STURGEON...TRAP ROCK AND MICHIGAMME RIVERS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 504 AM EDT MON MAY 12 2014 DEEP TROUGH FOR MAY AND REALLY ANYTIME OF THE YEAR STRETCHES FROM CENTRAL CANADA TO THE SOUTHERN PLAINS ON TUESDAY. SFC LOW CURRENTLY OVER THE CENTRAL PLAINS SHOULD BE JUST NORTHWEST OF LK SUPERIOR DAYBREAK ON TUESDAY. OCCLUDED FRONT WILL BE SLICING ACROSS CWA THROUGH MID MORNING...EXITING EASTERN CWA BY EARLY AFTN. SHOULD BE AT LEAST SCT SHRA/TSRA EXPECTED ALONG AND AHEAD OF FRONT AS HIGHER 1000-850MB THETA-E POOLS ALONG THE BOUNDARY. SHARP DRYING ENDS ANY RAIN QUICKLY OVER WEST HALF IN THE MORNING...BUT MAY SEE ISOLD SHRA/TSRA OVER FAR SOUTHEAST CWA AS WEAK LOW-LEVEL CONVERGENCE LINGERS AND AS ANOTHER WEAKER SHORTWAVE/Q-VECTOR CONVERGENCE AT H85-H5 LIFTS OVER FAR EAST CWA. ANY STORMS AHAEAD OF FRONT IN THE MORNING SHOULD BE WEAK AS 1-6KM MUCAPE AND MLCAPE BOTH DIMINISH STEADILY COMPARED TO THE OVERNIGHT HOURS. TEMPS WILL RISE INTO THE 60S OVER THE CNTRL WHERE WEST WINDS DOWNSLOPE...IMT-ESC-MNM...BUT WILL STAY IN THE 50S OVER THE WESTERN/NORTHWEST CWA WITH GRADIENT WINDS OFF LK SUPERIOR. THOSE WINDS COULD BE QUITE GUSTY...ESPECIALLY OVER THE MORE EXPOSED KEWEENAW...WHERE NAM/GFS SOUNDINGS INDICATE MIXED LAYER BUILDING TO H85-H8 WITH WINDS OVER 35 KTS IN THE MIXED LAYER. QUIET WEATHER TUESDAY NIGHT AND WEDNESDAY AS DEEP SFC LOW SLOWLY LIFTS TO JAMES BAY/HUDSON BAY. GRADIENT WEST FLOW STAYS OVER UPR MICHIGAN...BUT WILL LIGHTEN ENOUGH ON WEDNESDAY TO RESULT IN LAKE BREEZES. SLIM CHANCE THAT RESULTING LOW-LEVEL CONVERGENCE ADDED TO WEAK H7-H5 FORCING FM SHORTWAVE DROPPING ACROSS ON PERIFERY OF DEEP TROUGH ALOFT COULD TRIGGER A FEW SHOWERS/SPRINKLES INTERIOR CENTRAL. DEEP MIXING TO H8 WILL LIMIT POTENTIAL THOUGH AS LOW-LEVEL RH VALUES DROP OFF BLO 40 PCT. MAX TEMPS SHOULD PUSH INTO THE 50S INLAND AND FALL BACK INTO THE 40S NEAR LK SUPERIOR ONCE LAKE BREEZE DEVELOPS. THE FORECAST FOR THURSDAY INTO FRIDAY REMAINS UNCERTAIN. AT THE LEAST...TEMPS WILL BE BLO NORMAL FOR MOST CWA...PERHAPS BY MORE THAN 10-15F OVER THE NORTHERN CWA. ECMWF STILL SUPPORTS POTENTIAL FOR ACCUMULATING SNOW...NOW MAINLY DELAYED UNTIL THURSDAY NIGHT THROUGH FRIDAY AND POSSIBLY INTO FRIDAY NIGHT. LATEST UKMET ALSO IN LINE WITH THE ECMWF IDEA. MEANWHILE...GFS AND GEM-NH STAY WITH PROGRESSIVE IDEA INDICATING STRONG SHORTWAVE ROUNDING BASE OF DEEP TROUGH STAYS SEPARATE ENOUGH FROM TROUGH FROM HUDSON BAY TO THE NORTHERN PLAINS TO LIMIT PHASING. IF GFS THEME IDEA IS RIGHT...WOULD SEE SETUP WITH MORE DIURNALLY DRIVEN MAINLY RAIN SHOWERS DUE TO INSTABILITY ALOFT BENEATH THE TROUGH AXIS. IF THE ECMWF AND UKMET ARE ON THE RIGHT TRACK...THEY INDICATE ENOUGH PHASING BTWN THE LARGE SCALE TROUGHS TO DRAG A SFC LOW PRESSURE SYSTEM NORTHWARD OVER THE CNTRL GREAT LAKES INTO TOWARD THE UPPER GREAT LAKES THURSDAY INTO FRIDAY. WITH THAT SCNEARIO...WIDESPREAD RAIN AND SNOW THURSDAY EVENING WOULD CHANGE TO SNOW THURSDAY NIGHT INTO MUCH OF FRIDAY AND NORTHERLY FLOW WOULD ONLY BOOST THE SNOW OVER HIGHER TERRAIN AREAS NEAR LK SUPERIOR. SNOW COULD BE PRETTY WIDESRPEAD AS PYTPE WITH H85 TEMPS DROPPING BLO -5C AND SINCE 1000-850MB THICKNESSES FALL BLO 1300M. PHASING SYSTEMS ARE ALWAYS TOUGH TO FORECAST. ADD TO THAT FACT THAT WE ARE PUSHING INTO MIDDLE OF MAY AND IT MAKES IT REALLY TOUGH TO SAY IF UKMET AND ECMWF SOLUTION WILL WORK OUT AS FORECAST. SINCE ECMWF ENSEMBLE MEAN WOULD ALSO SUPPORT SIMILAR IDEA AND SOME CANADIAN ENSEMBLES HAVE SHOWN THIS RECENTLY IT DOES SUGGEST THE IDEA AT LEAST HAS SOME MERIT COMPARED TO JUST ONE ROUGE OPERATIONAL MODEL RUN SHOWING A BIG STORM IN THE FAR REACHES OF THE EXTENDED. ONCE THE SYSTEM OR JUST THE OPEN TROUGH MOVES BY...WEEKEND LOOKS DRIER WITH GRADUAL WARMING TREND. DID NOT STRAY FROM CONSENSUS LOW CHANCE POPS FOR NEXT WEEKEND ATTM. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 128 AM EDT MON MAY 12 2014 LINGERING DRY AIR AT THE LOW LEVELS WITH PREVAILING VFR CONDITIONS ARE EXPECTED TIL LATE IN THE NIGHT. A NORTHWARD MOVING LOW AND A WARM FRONT WILL SPREAD SHRA INTO UPPER MI...MAINLY AFT 09Z ALTHOUGH THERE IS STILL SOME UNCERTAINTY IN HOW FAST PCPN WILL DEVELOP. KIWD HAS THE BEST CHC OF CONDITIONS FALLING TO MVFR OVERNIGHT WITH THE ONSET OF RAIN. EXPECT ALL SITES TO QUICKLY FALL TO IFR OR LIFR IN LOWERING STRATUS BY 12Z OR SHORTLY THEREAFTER WITH CONTINUED SHOWERS AND ADVECTION OF HIGHER DEWPOINTS INTO THE AREA. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 504 AM EDT MON MAY 12 2014 EXPECT PERIOD OF STRONGER WINDS OVER LAKE SUPERIOR. APPROACHING LOW PRESSURE SYSTEM RESULTS IN NORTHEAST WINDS INCREASING TO GALES BY AFTN OVER WEST HALF OF LK SUPERIOR. WINDS TO 30 KTS OVER REST OF LK SUPERIOR. STRONG WINDS DIMINISH BRIEFLY LATER THIS EVENING AND OVERNIGHT TONIGHT AS THE LOW SLIDES ACROSS WESTERN LK SUPERIOR. ONCE THE LOW MOVES NORTH OF THE LAKE ON TUESDAY MORNING...STRONG WEST WINDS KICK UP. EXPECT THESE STRONG WESTERLIES...PROBABLY REACHING GALES ON TUESDAY OVER NCNTRL LK SUPERIOR...TO SLOWLY FADE BLO 25 KTS BY WEDNESDAY MORNING. WINDS REST OF THE WEEK WILL MAINLY BE BLO 20 KTS. HOWEVER...A LOW PRESSURE SYSTEM COULD IMPACT THE REGION LATE THIS WEEK WITH WINDS OVER 25 KTS THURSDAY INTO FRIDAY. UNCERTAINTY IS HIGH WITH THAT SYSTEM THOUGH...SO CURRENT FORECAST WILL ONLY CALL FOR NORTHWEST TO 20 KTS AT THIS TIME. && .HYDROLOGY... ISSUED AT 504 AM EDT MON MAY 12 2014 WIDESRPEAD MODERATE TO HEAVY RAIN WILL AFFECT ALL OF UPR MICHIGAN THROUGH EARLY THIS AFTN BEFORE DIMINISHING...THEN THERE MAY BE ANOTHER PERIOD OF MODERATE RAINFALL TONIGHT. RAINFALL AMOUNTS MAY EXCEED ONE INCH TODAY OVER PORTIONS OF WESTERN UPR MICHIGAN. RAIN CHANCES DIMINISH FROM WEST TO EAST ON TUESDAY AS A FRONTAL BOUNDARY EXITS THE REGION. RAINFALL WILL ONLY ADD TO THE ONGOING SNOWMELT AND ALREADY HIGH FLOWS ON AREA RIVERS AND STREAMS. THE PRIMARY CHANGE TO ONGOING HEADLINES WAS LAST EVENING...WHEN BASED ON EXPECTED RAINFALL...WHICH LOOKS LIKE IT IS WORKING OUT...ADVISORIES WERE UPGRADED TO WARNINGS FOR THE MICHIGAMME RIVER NEAR REPUBLIC AND WITCH LAKE. THE WARNING FOR THE STURGEON RIVER NEAR CHASSELL AND THE ADVISORY FOR THE STURGEON RIVER NEAR ALSTON CONTINUE...AS DOES THE ADVISORY FOR THE MICHIGAMME RIVER DOWNSTREAM OF WAY DAM...TO THE EAST OF CRYSTAL FALLS IN IRON COUNTY. GIVEN THE RAINFALL THAT WILL AFFECT THE AREA THE NEXT 24-36 HOURS...RIVER LEVELS WILL KEEP RISING AND ADJUSTMENTS WILL LIKELY BE NEEDED BASED ON LATEST TRENDS. ALL THIS WATER DUE TO THE SNOWMELT AND THE RAINFALL WILL TAKE A WHILE TO WORK THROUGH THE RIVERS...SO IT IS QUITE LIKELY THAT HIGHER RIVER FLOWS AND THE ASSOCIATED ADVISORIES AND WARNINGS ON AREA RIVERS WILL CONTINUE THROUGH LATE THIS WEEK...IF NOT INTO NEXT WEEKEND. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL MIDNIGHT EDT /11 PM CDT/ TONIGHT FOR LSZ162. GALE WARNING FROM 10 AM THIS MORNING TO 11 PM EDT THIS EVENING FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...JLA AVIATION...JLB MARINE...JLA HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
128 AM EDT MON MAY 12 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 347 PM EDT SUN MAY 11 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW STRONG SHORTWAVE ENERGY ROUNDING BASE OF AMPLIFIED TROF OVER THE FOUR CORNERS REGION OF THE SW CONUS. MODELS SHOW THIS STRONG SHORTWAVE BEGINNING TO EJECT NE FROM WRN/CENTRAL PLAINS TONIGHT AS ITS ASSOC SFC LOW LIFTS NE THROUGH THE PLAINS. INCREASING MOISTURE AND ISENTROPIC ASCENT AHEAD OF THIS LOW PRES SYSTEM SHOULD SIGNAL THE BEGINNING OF A FAIRLY WET PERIOD FOR THE CWA STARTING LATE TONIGHT AND CONTINUING INTO EARLY TUESDAY. TONIGHT...AS THE STRONGER SHORTWAVE BEGINS TO EJECT OUT OF THE DEEPENING UPPER TROF THE SFC LOW PRES WILL IN TURN LIFT NE THRU THE PLAINS. THE EVENING SHOULD REMAIN DRY...AND PERHAPS CONTINUE INTO THE OVERNIGHT OVER THE NE HALF OF THE FCST AREA CLOSER TO DRY LOW-LEVEL NE TRAJECTORIES OUT OF SFC HIGH PRES IN ONTARIO. MOST OF THE MODELS SHOW INCREASING 850-700 MB MOISTURE TRANSPORT AND ADVECTION INTO THE AREA FM THE SOUTH BTWN 06-12Z ALONG WITH INCREASING 300-305K WAA/ISENTROPIC ASCENT AHEAD OF THE APPROACHING LOW PRES SYSTEM. MODELS ALSO INDICATE A SUBTLE SHORTWAVE WILL LIFT NE INTO THE UPPER MISSISSIPPI VALLEY LATE TONIGHT THAT WILL FURTHER AID THE DEVELOPMENT/SPREAD OF SHRA NE INTO UPPER MI DURING THE OVERNIGHT. NOT MUCH INSTABILITY IS NOTED PER 0-3KM MUCAPE OFF THE NAM/GFS. WITH A COUPLE HUNDRED J/KG AND SHOWALTER INDEX FALLING JUST BLO 0C OVER THE FAR SCNTRL LATE TONIGHT IN MOST MODEL GUIDANCE...WILL CONTINUE THE MENTION OF THUNDER IN THAT AREA LATE TONIGHT. MONDAY...WITH H85 WARM FRONT IN THE VICINITY...MODELS SHOW CONTINUED MOISTURE TRANSPORT/ADVECTION AT H85-H7 ACROSS THE FRONTAL BOUNDARY AS PWATS OVER OUR AREA RISE TO AROUND 1.5 INCHES OR WELL OVER 200 PCT OF NORMAL. SHORTWAVE/PV ANAMOLY EMERGING NORTHEAST OUT OF THE WESTERN CONUS TROUGH WILL SPREAD AREA OF H85-H5 Q-VECTOR CONVERGENCE INTO THE UPPER GREAT LAKES BY MONDAY AFTERNOON. DESPITE THESE FAVORABLE FACTORS FOR SHOWERS...MODELS STILL DIFFER SOMEWHAT ON PLACEMENT OF MAXIMUM MOISTURE ADVECTION...WITH THE GFS AND NAM INDICATING BEST MOISTURE ADVECTION WEST AND THE REG GEM TO THE EAST. HOWEVER CORFIDI VECTORS...BOTH FORWARD AND BACKWARD PROPAGATING...ARE GENERALLY ORIENTED FROM WEST TO EAST ACROSS THE FCST AREA WHICH WOULD ARGUE SHOWERS MAKING IT INTO THE WRN FCST AREA SHOULD ADVECT INTO THE ERN COUNTIES AS WELL. GOING FCST LIKELY POPS STILL SEEM REASONABLE CONSIDERING THE H85 FRONT IS IN THE VICINTY. WILL CONTINUE IDEA OF LIKELY POPS WEST IN THE MORNING SPREADING EAST INTO THE AFTERNOON HRS. ALSO WILL CONTINUE TO KEEP MENTION OF TSRA MAINLY OVER SOUTH HALF INTO THE WESTERN CWA ALONG NORTHERN GRADIENT OF ELEVATED INSTABILITY WITH SEVERAL HUNDRED J/KG OF ELEVATED CAPE AND NEG SHOWALTER INDICES. BIGGEST THREAT WITH ANY TSRA WILL BE HEAVY RAIN GIVEN HIGH PWATS ACROSS AREA. ANY HEAVY RAIN OVER THE WRN COUNTIES WILL CONTINUE TO ADD MORE RUNOFF TO RIVERS ALREADY RUNNING NEAR BANKFULL...ESPECIALLY THE STURGEON...TRAP ROCK AND MICHIGAMME RIVERS. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 329 PM EDT SUN MAY 11 2014 AT THE START OF THE PERIOD /00Z TUE/ MODELS ARE IN DECENT LARGE SCALE AGREEMENT IN SHOWING A SHARP AND DEEP 500MB TROUGH FROM THE SASK/MANITOBA BORDER S ACROSS THE DAKOTAS THEN TO THE FOUR CORNERS REGION. A 1004MB SFC LOW WILL BE SOMEWHERE IN THE SERN MN TO NWRN WI. MODELS HAVE BEEN TRENDING TOWARD THE CURRENT SOLUTION THAT TAKES THE SFC LOW W OF THE CWA TO JUST N OF THE MN ARROWHEAD BY 12Z TUE. WITH THE MORE NLY TRACK...MODELS ARE NOW SHOWING THE SFC WARM FRONT MOVING INTO THE FAR SRN CWA MON NIGHT...BUT WITH COLD LAKE TEMPS AND CONVECTION EXPECTED ALONG THE FRONT...CONFIDENCE IN THE FRONT MOVING THAT FAR N IS LOW. FORCING FROM UPPER LEVEL HEIGHT FALLS FROM THE DEEPENING TROUGH...GOOD MOISTURE TRANSPORT AND ISENTROPIC ASCENT WILL FAVOR PERIODS OF MODERATE RAIN SHOWERS MON NIGHT INTO EARLY TUE. THE OCCLUDED/COLD FRONT WILL MOVE THROUGH FROM LATE MON NIGHT INTO TUE...BRINGING AN END TO THE BULK OF THE PRECIP. SOME SHOWERS COULD REDEVELOP BEHIND THE FRONT AS CLEARING OVER THE WRN U.P. MAY ALLOW FOR ENOUGH INSTABILITY. MODELS GENERALLY SHOW ADDITIONAL QPF AMOUNTS OF AN INCH...BUT THAT WILL BE HIGHLY DEPENDENT ON EXACT DETAILS OF CONVECTION...MAKING EXACT PRECIP AMOUNTS HIGHLY UNCERTAIN. INSTABILITY FOR CONVECTION WILL ALSO BE HIGHLY UNCERTAIN DUE TO DEPENDENCY ON WARM FRONTAL LOCATION AND OTHER CONVECTION. IF THE FRONT CAN MAKE IT FARTHER N...THE WARM NOSE AT 900MB MAY BE STRONG ENOUGH TO LEAD TO GREATER ELEVATED CONVECTION. GFS AND NAM ARE SHOWING UP TO AROUND 1000 J/KG OF ELEVATED CAPE OVER THE SCENTRAL CWA...BUT STILL THINK THAT IS NOT AS LIKELY AS THE FRONT WILL PROBABLY STAY FARTHER S. IF THE WORST CASE SCENARIO OF THE FARTHER N FRONTAL POSITION DOES OCCUR...SOME HAIL WOULD BE POSSIBLE SCENTRAL. THE ADDITIONAL QPF AMOUNTS /COMBINED WITH PRECIP ON MON/ WOULD LIKELY LEAD TO ADDITIONAL FLOODING CONCERNS ON AREA RIVERS THAT ALREADY HAVE ELEVATED LEVELS. THE UPPER TROUGH MOVES OVERHEAD THROUGH MUCH OF THE REST OF THE WORK WEEK...ALTHOUGH THE ECMWF CLOSES IT OFF INTO A LOW THU INTO FRI. THE ECMWF SOLUTION WOULD RESULT IN MORE WIDESPREAD PRECIP THU INTO FRI...BUT THE GFS AND GEM SOLUTIONS WITH THE OPEN TROUGH WOULD LEAD TO SCATTERED SHOWER ACTIVITY MAINLY DURING PEAK HEATING WED THROUGH FRI. THIS DUE TO 850MB TEMPS OF -2C TO -4C WED THROUGH FRI NIGHT /AND AS COLD AS -7C IF THE ECMWF SOLUTION PANS OUT/. OF COURSE...THIS WILL LEAD TO A RETURN OF SIGNIFICANTLY BELOW NORMAL TEMPS /10-15 DEGREES BELOW NORMAL/. NEXT WEEKEND LOOKS DRIER AND WARMER AS RIDGING MOVES OVERHEAD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 128 AM EDT MON MAY 12 2014 LINGERING DRY AIR AT THE LOW LEVELS WITH PREVAILING VFR CONDITIONS ARE EXPECTED TIL LATE IN THE NIGHT. A NORTHWARD MOVING LOW AND A WARM FRONT WILL SPREAD SHRA INTO UPPER MI...MAINLY AFT 09Z ALTHOUGH THERE IS STILL SOME UNCERTAINTY IN HOW FAST PCPN WILL DEVELOP. KIWD HAS THE BEST CHC OF CONDITIONS FALLING TO MVFR OVERNIGHT WITH THE ONSET OF RAIN. EXPECT ALL SITES TO QUICKLY FALL TO IFR OR LIFR IN LOWERING STRATUS BY 12Z OR SHORTLY THEREAFTER WITH CONTINUED SHOWERS AND ADVECTION OF HIGHER DEWPOINTS INTO THE AREA. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 347 PM EDT SUN MAY 11 2014 NE WINDS 15-25 KTS THIS EVENING WILL BEGIN TO INCREASE OVER WESTERN PORTIONS OF LK SUPERIOR LATE TONIGHT AND MORE SO ON MONDAY AS LOW PRESSURE APPROACHES FROM THE SOUTHWEST. DECIDED TO REPLACE GALE WATCH WITH GALE WARNING OVER WESTERN TWO ZONES LATE TONIGHT THROUGH TUE EVENING. WINDS OVER THE REST OF THE LAKE WILL STAY AT OR BLO 30 KTS. WINDS DIMINISH LATER MONDAY NIGHT AND THEN SWITCH TO THE WEST TO 20-25 KTS ON TUESDAY. LOW SLOWLY SLIDES TO THE NORTHEAST OF LK SUPERIOR REST OF THE WEEK...RESULTING IN NORTHWEST WINDS MAINLY STAYING BLO 20 KTS. && .HYDROLOGY... ISSUED AT 329 PM EDT SUN MAY 11 2014 HIGHS MOSTLY IN THE 60S TODAY WILL RESULT IN ADDITIONAL SNOWMELT OVER HIGHER TERRAIN OF NORTHERN UPR MICHIGAN. MINIMAL RAIN AMOUNTS ARE EXPECTED THROUGH AT LEAST EARLY TONIGHT...BUT RAIN CHANCES INCREASE LATE TONIGHT INTO TUESDAY MORNING. THERE IS A POTENTIAL FOR MODERATE TO HEAVY RAIN OVER THE AREAS THAT ARE STILL MELTING SNOW...SO THE RECENT HIGHER RIVER LEVELS WILL CONTINUE THROUGH MUCH OF THE UPCOMING WEEK. THE FLOOD WARNING CONTINUES FOR THE STURGEON RIVER NEAR CHASSELL...WHILE ADVISORIES ARE IN PLACE FOR OTHER PORTIONS OF THE STURGEON RIVER IN HOUGHTON AND BARAGA COUNTIES AS WELL AS PORTIONS OF THE MICHIGAMME RIVER. IF HEAVIER RAINS MATERIALIZE EARLY THIS WEEK... ADDITIONAL ADVISORIES AND WARNINGS MAY BE NEEDED. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 6 AM EDT /5 AM CDT/ THIS MORNING TO MIDNIGHT EDT /11 PM CDT/ TONIGHT FOR LSZ162. GALE WARNING FROM 10 AM THIS MORNING TO 11 PM EDT THIS EVENING FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...TITUS AVIATION...JLB MARINE...VOSS HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1220 PM CDT MON MAY 12 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 334 AM CDT MON MAY 12 2014 SHOWERS ARE PUSHING EAST OF OUR WEST CENTRAL WI COUNTIES EARLY THIS MORNING WITH JUST A FEW SCATTERED SHOWERS ACROSS THE MN COUNTIES. RAINFALL AMOUNTS OVERNIGHT FROM 1 TO 1.50 INCHES HAVE BEEN COMMON ACROSS SOUTHERN MN AND ADJOINING AREAS OF WEST CENTRAL WI. RAINFALL AMOUNTS DROP OFF TO AROUND A HALF INCH FROM WEST CENTRAL MN TO NW WI. THE DAY AHEAD WILL FEATURE A LOW PRESSURE SYSTEM MOVING SLOWLY NORTHEAST FROM IA TO THE SOUTHERN TWIN CITIES METRO BY EARLY THIS AFTERNOON. THE LOW SHOULD REACH FAR NORTHERN WI BY LATE THIS EVENING. THERE IS PLENTY OF POTENTIAL FOR SEVERE STORMS TO DEVELOP THIS AFTERNOON/EVENING IN THE VICINITY OF THE SURFACE LOW AND WARM FRONT EXTENDING TO THE EAST. LIMITING FACTORS WILL BE THE EXTENSIVE CLOUDINESS THAT WILL HOLD DOWN ON THE DESTABILIZATION. RAP DATA SHOWS A WARM POCKET MOVING NORTHEAST FROM IA THIS MORNING BETWEEN 650-700MB. THIS IS SQUARELY OVER WEST CENTRAL WI EARLY THIS AFTERNOON. LOW LEVEL LAPSE RATES SUFFER AS WELL AS SURFACE BASED CAPE. HOWEVER...BY LATE IN THE AFTERNOON...SOUNDING DATA FOR KEAU SHOWS THE POTENTIAL TO WARM ENOUGH TO GET PAST THE MID LEVEL WARM POCKET. SURFACE BASED CAPE REACHES A LITTLE MORE THAN 2000 J/KG. SHEAR IS ADEQUATE WITH 0-1KM REACHING 25 KNOTS WITH 0-6KM BETTER THAN 45 KNOTS. 500MB WINDS ARE VERY IMPRESSIVE WITH A CORE OF 60-70 KNOT WINDS PROGGED ACROSS THE TWIN CITIES AND WEST CENTRAL WI THIS AFTERNOON. OUR MPXWRF...THE HOPWRF AND THE SPCWRF START BREWING TROUBLE ALONG OUR MN/WI BORDER AREA BY 21Z WITH THE HINT OF A FEW SUPERCELLS ACROSS WEST CENTRAL WI INTO THE EARLY EVENING. GIVEN THE LOW LCLS...SHEAR AND WARM FRONT...A TORNADO OR TWO CAN NOT BE RULED OUT. IN FACT...THERE HAVE BEEN TORNADOES THE PAST TWO DAYS NEAR THE SURFACE LOW AND WARM FRONT. NORTHWEST WINDS WILL STRENGTHEN ACROSS THE FA TONIGHT IN THE WAKE OF THE LOW PRESSURE SYSTEM. THIS WILL USHER IN MUCH COOLER AIR THAT WILL BE WITH US FOR THE BALANCE OF THE WEEK AS A LARGE TROUGH ALOFT DOMINATES ACROSS THE MISSISSIPPI VALLEY REGION. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 334 AM CDT MON MAY 12 2014 THE THEME FOR THE LONG TERM PERIOD IS DRY WEATHER FOR THE UPPER MIDWEST. ALTHOUGH...IT WILL ALSO BE A COOL PERIOD MAINLY TUESDAY THROUGH FRIDAY AS TEMPERATURES WILL RUN 10 TO 15 DEGREES BELOW NORMAL. PICKING UP TUESDAY MORNING...THE UPPER LEVEL TROUGH AXIS WILL BE IN THE VICINITY OF THE WESTERN MN/EASTERN DAKOTAS BORDER. THE SURFACE LOW WILL HAVE LIFTED UP INTO ONTARIO NORTH OF LAKE SUPERIOR. THE NAM REMAINS STUBBORN IN HAVING THE MOVEMENT OF THE LOW A TAD SLOWER/GIVEN ITS DEEPER SOLUTION WITH THE TROUGH MONDAY NIGHT/...BUT IT HAS STARTED TO MOVE TOWARD THE GFS/EC SOLUTIONS. PREFERRED A EC/GFS BLEND THAT HAS THE LOW QUICKLY MOVING NORTH. THE UPPER TROUGH AND MOISTURE ON THE BACK SIDE OF THE LOW WARRANTED THE MENTION OF POPS ACROSS THE NORTHERN PART OF THE FA...BUT ANY PRECIPITATION WILL BE VERY LIGHT. WITH THE UPPER TROUGH OVERHEAD...TEMPERATURES WILL BE HELD IN THE 50S DURING THE DAY...AND WITH THE DEPARTING LOW NORTHWEST WINDS WILL BE BLUSTERY AND MAKE FOR A COOL DAY. WINDS SHOULD SLACKEN AND SKY COVER BEGIN TO BREAK UP TUESDAY EVENING. 850H TEMPS WILL FALL BELOW ZERO OVERNIGHT AND GIVEN WEAKENING WINDS AND AND DIMINISHING SKY COVER OVERNIGHT...TEMPERATURES BY EARLY WEDNESDAY MORNING WILL BE IN THE 30S ACROSS THE FA. LITTLE CHANGE IS EXPECTED WEDNESDAY AS THE AMPLIFIED UPPER TROUGH AND CORE OF THE COOL AIR REMAINS OVERHEAD. MEANWHILE...BOTH THE EAST COAST AND WEST COAST WILL HAVE HIGHLY AMPLIFIED RIDGING AND WARM TEMPERATURES. SLIGHT CHANCE POPS DO SHOW UP AGAIN WEDNESDAY AFTERNOON ACROSS THE WEST AS ADDITIONAL MOISTURE ALOFT ROTATES SOUTH ON THE BACK SIDE OF THE UPPER TROUGH. WOULD NOT BE SURPRISED IF LOW LEVEL DRY AIR PREVENTS ANYTHING FROM REACHING THE GROUND. WEDNESDAY NIGHT WILL BE COLDER AS 850H TEMPS DROP TO -2C TO -6C GENERALLY ACROSS THE FA. WIDESPREAD 30S ARE EXPECTED WITH SOME SPOTS HITTING THE FREEZING MARK. THE AMPLIFIED TROUGH WILL PUSH SLIGHTLY EAST AND BECOME A CLOSED UPPER LOW OVER WISCONSIN THURSDAY NIGHT INTO FRIDAY SO CYCLONICALLY CURVED FLOW MAY AGAIN PRODUCE VERY LIGHT PRECIP THURSDAY AFTERNOON. THE POPS ASSOCIATED WITH THIS TROUGH DURING THE MIDWEEK MAY BE OVERDONE BY THE LARGE SCALE SYNOPTIC MODELS...HOWEVER...SO WHILE THERE ARE SOME POPS IN THE FORECAST FOR THE MIDWEEK TIME FRAME...TOTAL AMOUNTS WILL BE UNDER A TENTH OF AN INCH...AND WILL LIKELY BE ZERO FOR PARTS OF THE AREA. WE`LL SEE THE CORE OF THE COOL AIR ALOFT PUSH EAST AT THE START OF THE WEEKEND AS THE WESTERN CONUS RIDGE STARTS PUSHING INTO THE CENTER OF THE COUNTRY BY SUNDAY. BESIDES A COOL START...THE WEEKEND LOOKS DRY...PARTLY CLOUDY...AND WARMER THAN THE COLD MIDWEEK AHEAD. BEYOND THE WEEKEND...THE RIDGE AXIS WILL PUSH OVER OUR AREA EARLY NEXT WEEK AND TEMPERATURES WILL CONTINUE TO WARM. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1203 PM CDT MON MAY 12 2014 WEAK SFC LOW THAT WAS ACROSS EC MN THIS MORNING HAS SHIFTED FURTHER TO THE NE AND W/NW WINDS HAVE NEARLY MOVED THRU THE METRO AREA. ONLY AREAS WITH A SOUTHERLY WIND FLOW WAS ACROSS WC WI/SE MN WHERE THE BEST CHC OF ANY TSRA ACTIVITY IN THE NEXT 6 TO 12 HRS. IN ADDITION TO THE WINDS SHIFTING TO THE W/NW...CIGS DROP TO IFR/LIFR AND VSBYS DROP WITH DRIZZLE/-RA. MORE PERSISTENT SHRA WERE ACROSS SD/ND EARLY THIS AFTN. WILL CONTINUE CHC POPS...BUT IT WILL LIKELY BE MORE SCATTERED IN NATURE WITH A BETTER CHC OF WIDESPREAD ACTIVITY ACROSS WC MN DURING THE LATE AFTN AS THE MAIN UPPER LOW MOVES ACROSS THE UPPER MIDWEST. CIGS/VSBYS WILL REMAIN IFR/LIFR FOR THE BULK OF THE AFTN/EVENING ACROSS MN...WITH WC WI HAVING THE BEST CHC OF MVFR CIGS AND TSRA. CONFIDENCE IN TSRA REMAINS LOW FOR ALL MPX TAF SITES WITH THE EXCEPTION OF KEAU WHERE VCTS LOOKS REASONABLE FOR THIS AFTN/EVENING. WILL UPDATE KEAU AS PER LATEST RADAR AND ADJUST AS NEEDED. WINDS WILL REMAIN FROM THE NW/WNW THRU THE PERIOD ACROSS MN...WITH WINDS SHIFTING TO THE W/NW AT KRNH BY EARLY/MID AFTN...AND AT KEAU AFT 23Z. KMSP... WINDS HAVE SHIFTED TO THE NW IN THE LAST HR...WHICH BASICALLY CAUSES ANY CHC/S OF TSRA ALMOST NIL THIS AFTN WITH ONLY A SMALL CHC BASED ON MID LEVEL LAPSE RATES IN FAR EC MN. WILL LEAVE OUT VCTS ATTM...BUT WILL NEED TO SEE HOW CONVECTION DEVELOPS IN NC IA THIS AFTN. OTHERWISE...IFR CIGS WILL CONTINUE WITH VSBYS SLOWLY IMPROVING LATER THIS AFTN/EVENING AS WINDS INCREASE FROM THE WNW/NW AND BECOME GUSTY. SOME INSTABILITY SHRA ARE POSSIBLE TUESDAY AFTN...BUT NOT CONFIDENT ENOUGH TO WARRANT ANYTHING MORE THAN VCSH AFT 18Z. CIGS SHOULD BEGIN TO LIFT TUESDAY MORNING...WITH VFR CIGS DURING THE AFTN. /OUTLOOK FOR KMSP/ TUE AFTN...VFR. MVFR POSSIBLE IN -SHRA. WINDS W-NW 15-20 KTS. WED...VFR. WINDS W 5-15 KTS. THU...VFR. WINDS N/NE 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...RAH LONG TERM...SPD AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
706 AM CDT MON MAY 12 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 334 AM CDT MON MAY 12 2014 SHOWERS ARE PUSHING EAST OF OUR WEST CENTRAL WI COUNTIES EARLY THIS MORNING WITH JUST A FEW SCATTERED SHOWERS ACROSS THE MN COUNTIES. RAINFALL AMOUNTS OVERNIGHT FROM 1 TO 1.50 INCHES HAVE BEEN COMMON ACROSS SOUTHERN MN AND ADJOINING AREAS OF WEST CENTRAL WI. RAINFALL AMOUNTS DROP OFF TO AROUND A HALF INCH FROM WEST CENTRAL MN TO NW WI. THE DAY AHEAD WILL FEATURE A LOW PRESSURE SYSTEM MOVING SLOWLY NORTHEAST FROM IA TO THE SOUTHERN TWIN CITIES METRO BY EARLY THIS AFTERNOON. THE LOW SHOULD REACH FAR NORTHERN WI BY LATE THIS EVENING. THERE IS PLENTY OF POTENTIAL FOR SEVERE STORMS TO DEVELOP THIS AFTERNOON/EVENING IN THE VICINITY OF THE SURFACE LOW AND WARM FRONT EXTENDING TO THE EAST. LIMITING FACTORS WILL BE THE EXTENSIVE CLOUDINESS THAT WILL HOLD DOWN ON THE DESTABILIZATION. RAP DATA SHOWS A WARM POCKET MOVING NORTHEAST FROM IA THIS MORNING BETWEEN 650-700MB. THIS IS SQUARELY OVER WEST CENTRAL WI EARLY THIS AFTERNOON. LOW LEVEL LAPSE RATES SUFFER AS WELL AS SURFACE BASED CAPE. HOWEVER...BY LATE IN THE AFTERNOON...SOUNDING DATA FOR KEAU SHOWS THE POTENTIAL TO WARM ENOUGH TO GET PAST THE MID LEVEL WARM POCKET. SURFACE BASED CAPE REACHES A LITTLE MORE THAN 2000 J/KG. SHEAR IS ADEQUATE WITH 0-1KM REACHING 25 KNOTS WITH 0-6KM BETTER THAN 45 KNOTS. 500MB WINDS ARE VERY IMPRESSIVE WITH A CORE OF 60-70 KNOT WINDS PROGGED ACROSS THE TWIN CITIES AND WEST CENTRAL WI THIS AFTERNOON. OUR MPXWRF...THE HOPWRF AND THE SPCWRF START BREWING TROUBLE ALONG OUR MN/WI BORDER AREA BY 21Z WITH THE HINT OF A FEW SUPERCELLS ACROSS WEST CENTRAL WI INTO THE EARLY EVENING. GIVEN THE LOW LCLS...SHEAR AND WARM FRONT...A TORNADO OR TWO CAN NOT BE RULED OUT. IN FACT...THERE HAVE BEEN TORNADOES THE PAST TWO DAYS NEAR THE SURFACE LOW AND WARM FRONT. NORTHWEST WINDS WILL STRENGTHEN ACROSS THE FA TONIGHT IN THE WAKE OF THE LOW PRESSURE SYSTEM. THIS WILL USHER IN MUCH COOLER AIR THAT WILL BE WITH US FOR THE BALANCE OF THE WEEK AS A LARGE TROUGH ALOFT DOMINATES ACROSS THE MISSISSIPPI VALLEY REGION. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 334 AM CDT MON MAY 12 2014 THE THEME FOR THE LONG TERM PERIOD IS DRY WEATHER FOR THE UPPER MIDWEST. ALTHOUGH...IT WILL ALSO BE A COOL PERIOD MAINLY TUESDAY THROUGH FRIDAY AS TEMPERATURES WILL RUN 10 TO 15 DEGREES BELOW NORMAL. PICKING UP TUESDAY MORNING...THE UPPER LEVEL TROUGH AXIS WILL BE IN THE VICINITY OF THE WESTERN MN/EASTERN DAKOTAS BORDER. THE SURFACE LOW WILL HAVE LIFTED UP INTO ONTARIO NORTH OF LAKE SUPERIOR. THE NAM REMAINS STUBBORN IN HAVING THE MOVEMENT OF THE LOW A TAD SLOWER/GIVEN ITS DEEPER SOLUTION WITH THE TROUGH MONDAY NIGHT/...BUT IT HAS STARTED TO MOVE TOWARD THE GFS/EC SOLUTIONS. PREFERRED A EC/GFS BLEND THAT HAS THE LOW QUICKLY MOVING NORTH. THE UPPER TROUGH AND MOISTURE ON THE BACK SIDE OF THE LOW WARRANTED THE MENTION OF POPS ACROSS THE NORTHERN PART OF THE FA...BUT ANY PRECIPITATION WILL BE VERY LIGHT. WITH THE UPPER TROUGH OVERHEAD...TEMPERATURES WILL BE HELD IN THE 50S DURING THE DAY...AND WITH THE DEPARTING LOW NORTHWEST WINDS WILL BE BLUSTERY AND MAKE FOR A COOL DAY. WINDS SHOULD SLACKEN AND SKY COVER BEGIN TO BREAK UP TUESDAY EVENING. 850H TEMPS WILL FALL BELOW ZERO OVERNIGHT AND GIVEN WEAKENING WINDS AND AND DIMINISHING SKY COVER OVERNIGHT...TEMPERATURES BY EARLY WEDNESDAY MORNING WILL BE IN THE 30S ACROSS THE FA. LITTLE CHANGE IS EXPECTED WEDNESDAY AS THE AMPLIFIED UPPER TROUGH AND CORE OF THE COOL AIR REMAINS OVERHEAD. MEANWHILE...BOTH THE EAST COAST AND WEST COAST WILL HAVE HIGHLY AMPLIFIED RIDGING AND WARM TEMPERATURES. SLIGHT CHANCE POPS DO SHOW UP AGAIN WEDNESDAY AFTERNOON ACROSS THE WEST AS ADDITIONAL MOISTURE ALOFT ROTATES SOUTH ON THE BACK SIDE OF THE UPPER TROUGH. WOULD NOT BE SURPRISED IF LOW LEVEL DRY AIR PREVENTS ANYTHING FROM REACHING THE GROUND. WEDNESDAY NIGHT WILL BE COLDER AS 850H TEMPS DROP TO -2C TO -6C GENERALLY ACROSS THE FA. WIDESPREAD 30S ARE EXPECTED WITH SOME SPOTS HITTING THE FREEZING MARK. THE AMPLIFIED TROUGH WILL PUSH SLIGHTLY EAST AND BECOME A CLOSED UPPER LOW OVER WISCONSIN THURSDAY NIGHT INTO FRIDAY SO CYCLONICALLY CURVED FLOW MAY AGAIN PRODUCE VERY LIGHT PRECIP THURSDAY AFTERNOON. THE POPS ASSOCIATED WITH THIS TROUGH DURING THE MIDWEEK MAY BE OVERDONE BY THE LARGE SCALE SYNOPTIC MODELS...HOWEVER...SO WHILE THERE ARE SOME POPS IN THE FORECAST FOR THE MIDWEEK TIME FRAME...TOTAL AMOUNTS WILL BE UNDER A TENTH OF AN INCH...AND WILL LIKELY BE ZERO FOR PARTS OF THE AREA. WE`LL SEE THE CORE OF THE COOL AIR ALOFT PUSH EAST AT THE START OF THE WEEKEND AS THE WESTERN CONUS RIDGE STARTS PUSHING INTO THE CENTER OF THE COUNTRY BY SUNDAY. BESIDES A COOL START...THE WEEKEND LOOKS DRY...PARTLY CLOUDY...AND WARMER THAN THE COLD MIDWEEK AHEAD. BEYOND THE WEEKEND...THE RIDGE AXIS WILL PUSH OVER OUR AREA EARLY NEXT WEEK AND TEMPERATURES WILL CONTINUE TO WARM. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 706 AM CDT MON MAY 12 2014 SURFACE LOW PRESSURE OVER FAR SOUTH CENTRAL MN WILL BE MOVING SLOWLY NORTHEAST TODAY...REACHING THE TWIN CITIES BY EARLY THIS AFTERNOON AND NORTHERN WI BY LATE THIS EVENING. IFR CEILINGS AND MVFR VSBYS IN -RA/DZ/BR ARE WIDESPREAD ON THE COLD SIDE OF THE LOW (KRWF/KSTC/KAXN). THESE SITES SHOULD STAY THIS WAY THROUGH THE DAY WITH ONLY A LITTLE IMPROVEMENT OVERNIGHT. CONFIDENCE IS LOWER FOR KMSP...KRNH AND KEAU WHERE MAINLY VFR CEILINGS EXISTS. HOWEVER...DUE TO THE HIGHS DEW POINTS AND NEAR SATURATION IN THE LOW LEVELS...MVFR OR LOWER CIGS SHOULD DEVELOP THIS MORNING AND PERSIST THROUGH THE AFTERNOON AND THEN LOWER TO IFR TONIGHT ON THE BACKSIDE OF THE LOW. SOME SHOWERS WILL MOVE THROUGH THIS MORNING WITH THE THREAT FOR THUNDERSTORMS THIS AFTERNOON AND EARLY EVENING. CONFIDENCE IS HIGHEST FOR THUNDER AT KEAU DURING THE LATE AFTERNOON HOURS. SOUTHEAST WINDS AHEAD OF THE LOW ON THE WARM SIDE WITH NORTH TO NORTHWEST WINDS 10-15 KNOTS ON THE COLD SIDE. KMSP...LOW CONFIDENCE FORECAST ON MVFR CEILINGS THIS MORNING. ERRED ON THE LOW SIDE VERSUS VFR BEING OBSERVED FROM THE AIRFIELD ON SOUTH AND EAST. FIGURING A LITTLE HEATING THIS MORNING WITH THE SATURATED CONDITIONS WILL RESULT IN LOW CEILINGS DEVELOPING QUICKLY. CERTAINLY THIS AFTERNOON AS WE TRANSITION TO THE BACKSIDE OF THE APPROACHING LOW PRESSURE SYSTEM CEILINGS WILL DROP TO IFR AND STAY THERE THROUGH MUCH OF TONIGHT. SHOWER/TSRA CHANCES ARE BEST TO THE EAST AND SOUTH OF THE AIRFIELD TODAY WITH -RA/DZ MORE LIKELY LATER THIS AFTERNOON AND TONIGHT. WINDS HAVE DIMINISHED SINCE TAF ISSUANCE WITH LIGHT WINDS FOR THE NEXT FEW HOURS. THE WINDS SHOULD PICK UP LATER IN THE MORNING FROM THE NE AND THEN BECOME NW THIS AFTERNOON. /OUTLOOK FOR KMSP/ TUE...MVFR LIKELY. SLGT CHC -SHRA. WINDS W-NW 15-20 KTS. WED...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS W-NW 10-15 KTS. THU...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS NW 10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...RAH LONG TERM...SPD AVIATION...RAH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
421 AM CDT MON MAY 12 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 334 AM CDT MON MAY 12 2014 SHOWERS ARE PUSHING EAST OF OUR WEST CENTRAL WI COUNTIES EARLY THIS MORNING WITH JUST A FEW SCATTERED SHOWERS ACROSS THE MN COUNTIES. RAINFALL AMOUNTS OVERNIGHT FROM 1 TO 1.50 INCHES HAVE BEEN COMMON ACROSS SOUTHERN MN AND ADJOINING AREAS OF WEST CENTRAL WI. RAINFALL AMOUNTS DROP OFF TO AROUND A HALF INCH FROM WEST CENTRAL MN TO NW WI. THE DAY AHEAD WILL FEATURE A LOW PRESSURE SYSTEM MOVING SLOWLY NORTHEAST FROM IA TO THE SOUTHERN TWIN CITIES METRO BY EARLY THIS AFTERNOON. THE LOW SHOULD REACH FAR NORTHERN WI BY LATE THIS EVENING. THERE IS PLENTY OF POTENTIAL FOR SEVERE STORMS TO DEVELOP THIS AFTERNOON/EVENING IN THE VICINITY OF THE SURFACE LOW AND WARM FRONT EXTENDING TO THE EAST. LIMITING FACTORS WILL BE THE EXTENSIVE CLOUDINESS THAT WILL HOLD DOWN ON THE DESTABILIZATION. RAP DATA SHOWS A WARM POCKET MOVING NORTHEAST FROM IA THIS MORNING BETWEEN 650-700MB. THIS IS SQUARELY OVER WEST CENTRAL WI EARLY THIS AFTERNOON. LOW LEVEL LAPSE RATES SUFFER AS WELL AS SURFACE BASED CAPE. HOWEVER...BY LATE IN THE AFTERNOON...SOUNDING DATA FOR KEAU SHOWS THE POTENTIAL TO WARM ENOUGH TO GET PAST THE MID LEVEL WARM POCKET. SURFACE BASED CAPE REACHES A LITTLE MORE THAN 2000 J/KG. SHEAR IS ADEQUATE WITH 0-1KM REACHING 25 KNOTS WITH 0-6KM BETTER THAN 45 KNOTS. 500MB WINDS ARE VERY IMPRESSIVE WITH A CORE OF 60-70 KNOT WINDS PROGGED ACROSS THE TWIN CITIES AND WEST CENTRAL WI THIS AFTERNOON. OUR MPXWRF...THE HOPWRF AND THE SPCWRF START BREWING TROUBLE ALONG OUR MN/WI BORDER AREA BY 21Z WITH THE HINT OF A FEW SUPERCELLS ACROSS WEST CENTRAL WI INTO THE EARLY EVENING. GIVEN THE LOW LCLS...SHEAR AND WARM FRONT...A TORNADO OR TWO CAN NOT BE RULED OUT. IN FACT...THERE HAVE BEEN TORNADOES THE PAST TWO DAYS NEAR THE SURFACE LOW AND WARM FRONT. NORTHWEST WINDS WILL STRENGTHEN ACROSS THE FA TONIGHT IN THE WAKE OF THE LOW PRESSURE SYSTEM. THIS WILL USHER IN MUCH COOLER AIR THAT WILL BE WITH US FOR THE BALANCE OF THE WEEK AS A LARGE TROUGH ALOFT DOMINATES ACROSS THE MISSISSIPPI VALLEY REGION. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 334 AM CDT MON MAY 12 2014 THE THEME FOR THE LONG TERM PERIOD IS DRY WEATHER FOR THE UPPER MIDWEST. ALTHOUGH...IT WILL ALSO BE A COOL PERIOD MAINLY TUESDAY THROUGH FRIDAY AS TEMPERATURES WILL RUN 10 TO 15 DEGREES BELOW NORMAL. PICKING UP TUESDAY MORNING...THE UPPER LEVEL TROUGH AXIS WILL BE IN THE VICINITY OF THE WESTERN MN/EASTERN DAKOTAS BORDER. THE SURFACE LOW WILL HAVE LIFTED UP INTO ONTARIO NORTH OF LAKE SUPERIOR. THE NAM REMAINS STUBBORN IN HAVING THE MOVEMENT OF THE LOW A TAD SLOWER/GIVEN ITS DEEPER SOLUTION WITH THE TROUGH MONDAY NIGHT/...BUT IT HAS STARTED TO MOVE TOWARD THE GFS/EC SOLUTIONS. PREFERRED A EC/GFS BLEND THAT HAS THE LOW QUICKLY MOVING NORTH. THE UPPER TROUGH AND MOISTURE ON THE BACK SIDE OF THE LOW WARRANTED THE MENTION OF POPS ACROSS THE NORTHERN PART OF THE FA...BUT ANY PRECIPITATION WILL BE VERY LIGHT. WITH THE UPPER TROUGH OVERHEAD...TEMPERATURES WILL BE HELD IN THE 50S DURING THE DAY...AND WITH THE DEPARTING LOW NORTHWEST WINDS WILL BE BLUSTERY AND MAKE FOR A COOL DAY. WINDS SHOULD SLACKEN AND SKY COVER BEGIN TO BREAK UP TUESDAY EVENING. 850H TEMPS WILL FALL BELOW ZERO OVERNIGHT AND GIVEN WEAKENING WINDS AND AND DIMINISHING SKY COVER OVERNIGHT...TEMPERATURES BY EARLY WEDNESDAY MORNING WILL BE IN THE 30S ACROSS THE FA. LITTLE CHANGE IS EXPECTED WEDNESDAY AS THE AMPLIFIED UPPER TROUGH AND CORE OF THE COOL AIR REMAINS OVERHEAD. MEANWHILE...BOTH THE EAST COAST AND WEST COAST WILL HAVE HIGHLY AMPLIFIED RIDGING AND WARM TEMPERATURES. SLIGHT CHANCE POPS DO SHOW UP AGAIN WEDNESDAY AFTERNOON ACROSS THE WEST AS ADDITIONAL MOISTURE ALOFT ROTATES SOUTH ON THE BACK SIDE OF THE UPPER TROUGH. WOULD NOT BE SURPRISED IF LOW LEVEL DRY AIR PREVENTS ANYTHING FROM REACHING THE GROUND. WEDNESDAY NIGHT WILL BE COLDER AS 850H TEMPS DROP TO -2C TO -6C GENERALLY ACROSS THE FA. WIDESPREAD 30S ARE EXPECTED WITH SOME SPOTS HITTING THE FREEZING MARK. THE AMPLIFIED TROUGH WILL PUSH SLIGHTLY EAST AND BECOME A CLOSED UPPER LOW OVER WISCONSIN THURSDAY NIGHT INTO FRIDAY SO CYCLONICALLY CURVED FLOW MAY AGAIN PRODUCE VERY LIGHT PRECIP THURSDAY AFTERNOON. THE POPS ASSOCIATED WITH THIS TROUGH DURING THE MIDWEEK MAY BE OVERDONE BY THE LARGE SCALE SYNOPTIC MODELS...HOWEVER...SO WHILE THERE ARE SOME POPS IN THE FORECAST FOR THE MIDWEEK TIME FRAME...TOTAL AMOUNTS WILL BE UNDER A TENTH OF AN INCH...AND WILL LIKELY BE ZERO FOR PARTS OF THE AREA. WE`LL SEE THE CORE OF THE COOL AIR ALOFT PUSH EAST AT THE START OF THE WEEKEND AS THE WESTERN CONUS RIDGE STARTS PUSHING INTO THE CENTER OF THE COUNTRY BY SUNDAY. BESIDES A COOL START...THE WEEKEND LOOKS DRY...PARTLY CLOUDY...AND WARMER THAN THE COLD MIDWEEK AHEAD. BEYOND THE WEEKEND...THE RIDGE AXIS WILL PUSH OVER OUR AREA EARLY NEXT WEEK AND TEMPERATURES WILL CONTINUE TO WARM. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1221 AM CDT MON MAY 12 2014 RAIN WITH EMBEDDED TSTMS SPREAD ACROS ENTIRE COVERAGE AREA... ALTHOUGH BACK EDGE HAS ENTERED SWRN MN AND IS PROGRESSING NEWD. HAVE TRIED TO TIME THIS BACK EDGE ACRS ALL TAF SITES DURING THE FIRST PORTION OF THE 12/06Z TAF SET. CEILINGS HAVE STEADILY LOWERED...AND ONCE THE PRECIP ENDS...AM LOOKING FOR CIGS TO DROP INTO IFR RANGE DUE TO LOW LEVEL MOISTURE CAUSING LOW STRATUS DEVELOPMENT. WITH WINDS NOT GOING CALM...STAYING CLOSE TO 5 KT OVERNIGHT EVEN WHEN GOING VRBL IN ERN MN INTO WRN WI...NOT LOOKING FOR ANYTHING WORSE THAN MVFR VSBY. THERE LOOKS TO BE A SECOND BATCH OF -RA FOR LATE TMRW MRNG INTO TMRW AFTN. THERE ARE ENOUGH QUESTIONS REGARDING CONVECTIVE POTENTIAL SO HAVE OPTED TO OMIT ITS MENTION ATTM...BUT WILL ANALYZE LATEST MODELS AND DETERMINE IF CONVECTION NEEDS TO BE ADDED TO LATER TAFS. WINDS FROM THE E AND SE WILL GO VRBL ARND DAYBREAK THEN ALL SITES WILL SWING TO THE W AND NW THIS AFTN AND REMAIN THERE THRU THE EVE. SUSTAINED SPEEDS WILL INCRS TO 10-15 KT WITH GUSTS NEAR 25 KT THIS AFTN AND EVE BEFORE SLIGHTLY DIMINISHING THIS EVE. KMSP...VFR CONDS TO START DESPITE WIDESPREAD -RA WITH A FEW TSRA...MAINLY S AND E OF MSP. STILL MAY BE POCKETS OF MOD/HVY RAIN IN THE FIRST COUPLE OF HRS THAT WILL DROP VSBY INTO IFR RANGE. ONCE THE RAIN EXITS...LOW STRATUS WITH MVFR VSBY WILL PREVAIL FOR THE REST OF THE EARLY MRNG HRS THRU ARND NOON. THEN THE NEXT BATCH OF RAIN WILL PUSH THRU...SLIGHTLY IMPROVING CONDITIONS AS THE RAIN HELPS WASH OUT SOME OF THE LOW LEVEL MOISTURE. AFTER THIS BATCH...THEN THE IFR CEILINGS ARE EXPECTED TO REDEVELOP. THAT SAID...CEILINGS SUB-1700 FT WILL LIKELY PREVAIL FOR MUCH OF THE TAF PERIOD STARTING OVERNIGHT AND PERSISTING THRU THE REST OF THIS TAF PERIOD. /OUTLOOK FOR KMSP/ TUE...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS W-NW 15-20 KTS. WED...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS W-NW 5-15 KTS. THU...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS NW 5-15 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...RAH LONG TERM...SPD AVIATION...JPC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1240 AM CDT MON MAY 12 2014 .UPDATE... ISSUED AT 1221 AM CDT MON MAY 12 2014 UPDATED TO INCLUDE 06Z AVIATION DISCUSSION BELOW. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 355 PM CDT SUN MAY 11 2014 EARLY AFTERNOON WATER VAPOR IMAGERY TOGETHER WITH RAP 500MB HEIGHTS AND WINDS IDENTIFIED A VIGOROUS SHORTWAVE ROTATING OVER THE 4-CORNERS REGION...WITH AN MCS ONGOING IN EASTERN IA. VISIBLE SATELLITE SHOWED CLEARING BEHIND THIS MCS...AND THE SURFACE OBS HAVE ALREADY REFLECTED THE BOUNDARY LAYER DESTABILIZATION AS TEMPERATURES HAVE INCREASED 5DEG/HR BUT KEPT THE EASTERLY COMPONENT IN THE WIND FIELD. THIS WIND SHIFT MARKED THE STOUT FRONTAL BOUNDARY WHICH WILL BE THE FOCUS FOR TORNADOES LATER THIS AFTERNOON ACROSS EASTERN NE AND WESTERN IA. TEMPERATURES WERE IN THE MID 80S SOUTH OF THIS WARM FRONT WITH SOUTHERLY WINDS...WHILE NORTH OF THE WARM FRONT TEMPERATURES WERE IN THE LOW TO MID 70S WITH DEWPOINTS IN THE MID 60S. THE MLCAPE GRADIENT MIRRORED THE POSITION OF THE EAST/WEST ORIENTED WARM FRONT...BUT INSTABILITY WAS BUILDING WELL NORTH OF THE FRONT AS EVIDENT BY THE 3HR SBCAPE CHANGE ON THE SPC MESOANALYSIS PAGE. THE FINAL POSITION OF THE WARM FRONT WILL DICTATE WHERE THE SURFACE BASED STORMS ARE...AND THUS THE BEST THREAT FOR TORNADOES. AT THIS TIME IT APPEARS THAT THE THREAT WILL REMAIN WELL SOUTH OF THE CWA. HOWEVER...THE LAST FEW RUNS OF THE HRRR AND HOPWRF INDICATE THAT A FEW ELEVATED STORMS ARE EXPECTED AFTER 00Z ACROSS THE SOUTHERN PART OF THE FORECAST AREA. THESE STORMS WILL HAVE 1000-1500J/KG OF MUCAPE TO WORK WITH DEEP SHEAR FAVORABLE FOR ORGANIZED CONVECTION. A FEW STORMS WILL HAVE THE POTENTIAL FOR PRODUCE SEVERE HAIL...MAINLY ALONG THE I-90 CORRIDOR. HEAVY RAIN IS ALSO A THREAT...PERHAPS MORESO THAN THE SEVERE WEATHER. AT THIS TIME...IT APPEARS THAT THE HEAVIEST RAINFALL WILL FALL JUST SOUTH AND EAST OF THE FORECAST AREA ALONG A LINE FROM OMAHA TO LA CROSSE WI. IT IS WITHIN THIS LINE THAT A HP SUPERCELLS ARE EXPECTED WHICH WILL BE CAPABLE OF PRODUCING 2-3IN/HR RAINFALL RATES AND FLASH FLOODING GIVEN THE RAINFALL THAT OCCURRED EARLIER THIS MORNING. IN OUR CWA...WE DID NOT HAVE THE MORNING RAINFALL...AND SUPERCELLS APPEAR LESS LIKELY...SO ALTHOUGH WE MAY GET A QUICK 1-2 INCHES OF RAIN WITH A FEW OF THE HEAVIER CELLS...THIS IS ABOVE FLASH FLOOD GUIDANCE. THEREFORE HAVE OPTED TO HOLD OFF ON A FLOOD WATCH FOR NOW. TO TIE BACK INTO THE HIRES MODELS...THE PROGRESSIVE NATURE OF THE EASTWARD MOVING STORMS ALSO SUPPORTS NOT ISSUING A FLOOD WATCH. THERE WILL BE A LULL IN THE PRECIP ACROSS CENTRAL MN AS THE SURFACE LOW TRACKS NORTHEASTWARD OVERNIGHT. MEANWHILE LIGHT RAIN WILL CONTINUE ACROSS THE WESTERN CWA IN THE DEFORMATION AREA OF THE UPPER LEVEL WAVE. FORECAST MODELS SHOW THE POTENTIAL FOR SOME CONVECTION REDEVELOPING IN THE WARM SECTOR OF THE SURFACE LOW ACROSS EASTERN MN AND WESTERN WI...SO TRIED TO REFLECT THAT IN THE AFTERNOON POP GRIDS. THESE STORMS DO HAVE THE POTENTIAL TO BE SEVERE. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 355 PM CDT SUN MAY 11 2014 NOT MUCH IN THE WAY OF CHANGE TO THE EXTENDED PORTION OF THE FORECAST...WITH THE UPCOMING WEEK BEING MARKED BY COOL TEMPERATURES AND PERIODIC SCATTERED LIGHT SHOWERS AS A DEEPLY AMPLIFIED LONGWAVE TROUGH PIVOTS ACROSS THE UPPER MIDWEST AND GREAT LAKES REGIONS. THE BEGINNING OF THE LONG TERM PERIOD /MONDAY NIGHT/ WILL FEATURE RAIN SHOWERS WINDING DOWN AS THE LOW LIFTS TO LAKE SUPERIOR. ADDITIONAL RAINFALL AMOUNTS SHOULD BE AROUND A COUPLE TENTHS OF AN INCH OR LESS. TUESDAY THROUGH FRIDAY BRINGS CYCLONIC FLOW WITH COOLER THAN NORMAL TEMPERATURES AND THE POTENTIAL FOR OCCASIONAL SCATTERED SHOWERS AS THE TROUGH BLANKETS THE REGION. HIGHS WILL BE IN THE 50S AND LOWS WILL DIP INTO THE LOWER 30S AND 40S. THE POTENTIAL FOR FROST LOOKS TO BE TUESDAY THROUGH THURSDAY NIGHTS. TEMPERATURES MODERATE NEXT WEEKEND AS WESTERN UPPER RIDGING BUILDS INTO THE CENTRAL CONUS. HIGHS IN THE 60S LOOK LIKE A GOOD BET FOR NEXT WEEKEND...ALTHOUGH A FEW SHOWERS MAY BE LURKING ON SUNDAY IF THE ECMWF SOLUTION VERIFIES /WHICH INDICATES A TROUGH WILL BUST IN FROM THE PACIFIC NORTHWEST AND BREAK DOWN THE RIDGE/. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1221 AM CDT MON MAY 12 2014 RAIN WITH EMBEDDED TSTMS SPREAD ACROS ENTIRE COVERAGE AREA... ALTHOUGH BACK EDGE HAS ENTERED SWRN MN AND IS PROGRESSING NEWD. HAVE TRIED TO TIME THIS BACK EDGE ACRS ALL TAF SITES DURING THE FIRST PORTION OF THE 12/06Z TAF SET. CEILINGS HAVE STEADILY LOWERED...AND ONCE THE PRECIP ENDS...AM LOOKING FOR CIGS TO DROP INTO IFR RANGE DUE TO LOW LEVEL MOISTURE CAUSING LOW STRATUS DEVELOPMENT. WITH WINDS NOT GOING CALM...STAYING CLOSE TO 5 KT OVERNIGHT EVEN WHEN GOING VRBL IN ERN MN INTO WRN WI...NOT LOOKING FOR ANYTHING WORSE THAN MVFR VSBY. THERE LOOKS TO BE A SECOND BATCH OF -RA FOR LATE TMRW MRNG INTO TMRW AFTN. THERE ARE ENOUGH QUESTIONS REGARDING CONVECTIVE POTENTIAL SO HAVE OPTED TO OMIT ITS MENTION ATTM...BUT WILL ANALYZE LATEST MODELS AND DETERMINE IF CONVECTION NEEDS TO BE ADDED TO LATER TAFS. WINDS FROM THE E AND SE WILL GO VRBL ARND DAYBREAK THEN ALL SITES WILL SWING TO THE W AND NW THIS AFTN AND REMAIN THERE THRU THE EVE. SUSTAINED SPEEDS WILL INCRS TO 10-15 KT WITH GUSTS NEAR 25 KT THIS AFTN AND EVE BEFORE SLIGHTLY DIMINISHING THIS EVE. KMSP...VFR CONDS TO START DESPITE WIDESPREAD -RA WITH A FEW TSRA...MAINLY S AND E OF MSP. STILL MAY BE POCKETS OF MOD/HVY RAIN IN THE FIRST COUPLE OF HRS THAT WILL DROP VSBY INTO IFR RANGE. ONCE THE RAIN EXITS...LOW STRATUS WITH MVFR VSBY WILL PREVAIL FOR THE REST OF THE EARLY MRNG HRS THRU ARND NOON. THEN THE NEXT BATCH OF RAIN WILL PUSH THRU...SLIGHTLY IMPROVING CONDITIONS AS THE RAIN HELPS WASH OUT SOME OF THE LOW LEVEL MOISTURE. AFTER THIS BATCH...THEN THE IFR CEILINGS ARE EXPECTED TO REDEVELOP. THAT SAID...CEILINGS SUB-1700 FT WILL LIKELY PREVAIL FOR MUCH OF THE TAF PERIOD STARTING OVERNIGHT AND PERSISTING THRU THE REST OF THIS TAF PERIOD. /OUTLOOK FOR KMSP/ TUE...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS W-NW 15-20 KTS. WED...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS W-NW 5-15 KTS. THU...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS NW 5-15 KTS. && .HYDROLOGY... ISSUED AT 355 PM CDT SUN MAY 11 2014 AT THIS TIME RIVER FLOODING APPEARS TO BE THE PRIMARY CONCERN MAINLY IN WESTERN WI AND THE MAINSTEM OF THE MISSISSIPPI RIVER. ANOTHER ROUND OF 1 TO 2 INCHES OF BASIN-WIDE RAINFALL IS EXPECTED OVER THE NEXT 24 HRS. AT THIS TIME...THE THREAT FOR THE HEAVIEST RAIN AND FLASH FLOODING APPEARS TO BE ACROSS IOWA...SO NOT ANTICIPATING ANY FLASH FLOODING IN MN OR WI. IF IT WERE TO HAPPEN...IT WOULD BE IN FAR SOUTHERN MN. LASTLY, IF THE FORECAST RAINFALL AMOUNTS TREND HIGHER THAN CURRENTLY EXPECTED...THE FLOODING POTENTIAL WILL INCREASE AS WELL. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ UPDATE...JPC SHORT TERM...JRB LONG TERM...LS AVIATION...JPC
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1239 PM CDT Mon May 12 2014 .SHORT TERM: (Today and Tonight) Issued at 330 AM CDT Mon May 12 2014 Main forecast issues for today are the probability of thunderstorms and any severe potential, as well as just how warm it may get. Current thinking is there should be a gradual upswing in convection as the day progresses, primarily during the later half of the afternoon. It appears that northeast Missouri will be the area we will have to watch most closely through mid morning. Two things to key an eye on - an outflow boundary pushing southeastward across eastern Iowa as a focus for additional thunderstorms, and also a cluster of thunderstorms across eastern Kansas just southwest of Kansas City and if they will hold together as they move northeastward. Otherwise I think that there will be a general decrease in the convective cloud debris during the morning, which given the mild early morning temperatures should allow for a quick warm-up by early afternoon. The convection allowing models and more specifically the HRRR is suggesting that by mid morning, isolated showers or thunderstorms could develop just about anywhere within the CWA, but most favored across southeast Missouri and southern Illinois. The main action still looks like the later half of the afternoon. The warm sector air mass ahead of the cold front will become quite unstable by mid-late afternoon with SBCAPE in excess of 2000 J/KG and little CIN. Expecting numerous thunderstorms to develop across western Missouri into central and northeast Missouri. Deep layer shear of 20-30 kts and the anticipated CAPE would support a few severe storms capable of large hail and damaging winds from the afternoon into about mid-evening. The front moves through all but the far eastern sections of the CWA tonight accompanied by widespread showers and thunderstorms and ushering much cooler air into the region in its wake. It also appears that there will be an increasing amount of post-frontal showers overnight immediately in the cool air in response to large scale forcing. Glass .LONG TERM: (Tuesday through Sunday) Issued at 330 AM CDT Mon May 12 2014 This marks the beginning of a cooler than normal period with a slow-moving and deep upper trof dominating the region through the week. The front will quickly exit the remainder of the CWA early Tuesday morning with post-frontal showers impacting eastern Missouri and southwest Illinois in the morning and exiting by early-mid afternoon. Highs on Tuesday will be around 20 degrees cooler than today. A strong short-wave and possibly upper low will then migrate through the base of the deep trof from the southern Plains and into the mid MS valley Tuesday night-Wednesday night. More reminiscent of Fall or early Spring, large scale ascent with this system should produce a large area of showers or rain spreading into the area late Tuesday night into Wednesday. Its northward extent and longevity is all dependent on the strength of the system, and NAM featuring a closed low and large deformation zone, has the greatest northward push and keeps precipitation well into Wednesday night. Regardless the precipitation and accompanying overcast low clouds will keep temperatures well below average on Wednesday. We could continue to see a periodic shower threat through the end of the week as we get into deeper cyclonic flow on the backside of the slow-moving deep upper trof. Temperatures will remain below average into at least Friday. Glass && .AVIATION: (For the 18z TAFs through 18z Tuesday Afternoon) Issued at 1227 PM CDT Mon May 12 2014 Specifics for KSTL, KSUS, KCPS, KUIN, KCOU: An approaching cold front will likely bring a period of SHRA/TSRA to all TAF sites during the late afternoon and evening. A stray shower or thunderstorm is possible early this afternoon, but the main precipitation threat is with the front. A broad area of MVFR cigs is located behind the front, and these clouds will remain over the terminals even after the front has moved eastward and precipitation has ended. Initially south to southwest winds will become northwesterly after fropa. Kanofsky && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
650 AM CDT Mon May 12 2014 .SHORT TERM: (Today and Tonight) Issued at 330 AM CDT Mon May 12 2014 Main forecast issues for today are the probability of thunderstorms and any severe potental, as well as just how warm it may get. Current thinking is there should be a gradual upswing in convection as the day progresses, primarily during the later half of the afternoon. It appears that northeast Missouri will be the area we will have to watch most closely through mid morning. Two things to key an eye on - an outflow boundary pushing southeastward across eastern Iowa as a focus for additional thunderstorms, and also a cluster of thunderstorms across eastern Kansas just southwest of Kansas City and if they will hold together as they move northeastward. Otherwise I think that there will be a general decrease in the convective cloud debris during the morning, which given the mild early morning temperatures should allow for a quick warm-up by early afternoon. The convection allowing models and more specifically the HRRR is suggesting that by mid morning, isolated showers or thunderstorms could develop just about anywhere within the CWA, but most favored across southeast Missouri and southern Illinois. The main action still looks like the later half of the afternoon. The warm sector air mass ahead of the cold front will become quite unstable by mid-late afternoon with SBCAPE in excess of 2000 J/KG and little CIN. Expecting numerous thunderstorms to develop across western Missouri into central and northeast Missouri. Deep layer shear of 20-30 kts and the anticipated CAPE would support a few severe storms capable of large hail and damaging winds from the afternoon into about mid-evening. The front moves through all but the far eastern sections of the CWA tonight accompanied by widespread showers and thunderstorms and ushering much cooler air into the region in its wake. It also appears that there will be an increasing amount of post-frontal showers overnight immediately in the cool air in response to large scale forcing. Glass .LONG TERM: (Tuesday through Sunday) Issued at 330 AM CDT Mon May 12 2014 This marks the beginning of a cooler than normal period with a slow-moving and deep upper trof dominating the region through the week. The front will quickly exit the remainder of the CWA early Tuesday morning with post-frontal showers impacting eastern Missouri and southwest Illinois in the morning and exiting by early-mid afternoon. Highs on Tuesday will be around 20 degrees cooler than today. A strong short-wave and possibly upper low will then migrate through the base of the deep trof from the southern Plains and into the mid MS valley Tuesday night-Wednesday night. More reminiscent of Fall or early Spring, large scale ascent with this system should produce a large area of showers or rain spreading into the area late Tuesday night into Wednesday. Its northward extent and longevity is all dependent on the strength of the system, and NAM featuring a closed low and large deformation zone, has the greatest northward push and keeps precipitation well into Wednesday night. Regardless the precipitation and accompanying overcast low clouds will keep temperatures well below average on Wednesday. We could continue to see a periodic shower threat through the end of the week as we get into deeper cyclonic flow on the backside of the slow-moving deep upper trof. Temperatures will remain below average into at least Friday. Glass && .AVIATION: (For the 12z TAFs through 12z Tuesday Morning) Issued at 640 AM CDT Mon May 12 2014 Mvfr strato cu deck advecting northward in warm sector and will remain over region through mid morning before scattering out. Otherwise, main issue is the chance for showers and thunderstorms as cold front moves through region late this afternoon and tonight. Activity will be scattered ahead of boundary so added vcnty ts mention after 15z with tempo of thunderstorms later this afternoon, mainly after 21z. Once front moves through will still see some lingering showers through rest of forecast period. As for winds, to remain from the south and pickup with gusts to near 25kts at times today. Then veer to the west as front moves through and become northwesterly later tonight. Specifics for KSTL: Mvfr strato cu deck advecting northward in warm sector and will remain over region through mid morning before scattering out. Otherwise, main issue is the chance for showers and thunderstorms as cold front moves through region late this afternoon and tonight. Thunderstorms to develop and move in later this afternoon, mainly after 00z Tuesday. Once front moves through will still see some lingering showers through rest of forecast period. As for winds, to remain from the south and pickup with gusts to near 25kts at times today. Then veer to the west by 04z Tuesday as front moves through and become northwesterly after 09z Tuesday. Byrd && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
346 AM CDT Mon May 12 2014 .SHORT TERM: (Today and Tonight) Issued at 330 AM CDT Mon May 12 2014 Main forecast issues for today are the probability of thunderstorms and any severe potental, as well as just how warm it may get. Current thinking is there should be a gradual upswing in convection as the day progresses, primarily during the later half of the afternoon. It appears that northeast Missouri will be the area we will have to watch most closely through mid morning. Two things to key an eye on - an outflow boundary pushing southeastward across eastern Iowa as a focus for additional thunderstorms, and also a cluster of thunderstorms across eastern Kansas just southwest of Kansas City and if they will hold together as they move northeastward. Otherwise I think that there will be a general decrease in the convective cloud debris during the morning, which given the mild early morning temperatures should allow for a quick warm-up by early afternoon. The convection allowing models and more specifically the HRRR is suggesting that by mid morning, isolated showers or thunderstorms could develop just about anywhere within the CWA, but most favored across southeast Missouri and southern Illinois. The main action still looks like the later half of the afternoon. The warm sector air mass ahead of the cold front will become quite unstable by mid-late afternoon with SBCAPE in excess of 2000 J/KG and little CIN. Expecting numerous thunderstorms to develop across western Missouri into central and northeast Missouri. Deep layer shear of 20-30 kts and the anticipated CAPE would support a few severe storms capable of large hail and damaging winds from the afternoon into about mid-evening. The front moves through all but the far eastern sections of the CWA tonight accompanied by widespread showers and thunderstorms and ushering much cooler air into the region in its wake. It also appears that there will be an increasing amount of post-frontal showers overnight immediately in the cool air in response to large scale forcing. Glass .LONG TERM: (Tuesday through Sunday) Issued at 330 AM CDT Mon May 12 2014 This marks the beginning of a cooler than normal period with a slow-moving and deep upper trof dominating the region through the week. The front will quickly exit the remainder of the CWA early Tuesday morning with post-frontal showers impacting eastern Missouri and southwest Illinois in the morning and exiting by early-mid afternoon. Highs on Tuesday will be around 20 degrees cooler than today. A strong short-wave and possibly upper low will then migrate through the base of the deep trof from the southern Plains and into the mid MS valley Tuesday night-Wednesday night. More reminiscent of Fall or early Spring, large scale ascent with this system should produce a large area of showers or rain spreading into the area late Tuesday night into Wednesday. Its northward extent and longevity is all dependent on the strength of the system, and NAM featuring a closed low and large deformation zone, has the greatest northward push and keeps precipitation well into Wednesday night. Regardless the precipitation and accompanying overcast low clouds will keep temperatures well below average on Wednesday. We could continue to see a periodic shower threat through the end of the week as we get into deeper cyclonic flow on the backside of the slow-moving deep upper trof. Temperatures will remain below average into at least Friday. Glass && .AVIATION: (For the 06z TAFs through 06z Monday Night) Issued at 1136 PM CDT Sun May 11 2014 Expecting VFR flight conditions to prevail across most of the area for the rest of the night. Low level wind shear conditions will spread further than previously thought; probably as far east as southwest Illinois. Have included LLWS in all terminal forecasts. Thunderstorms over Iowa are trying to spread a bit further south into northern Missouri, however most guidance agrees that storms will be weakening as they get far enough east to threaten our area. Some widely scattered showers or storms may develop as diurnal heating increases during the late morning or early afternoon, but the primary threat for thunderstorms will be during the late afternoon and evening ahead of the cold front. Guidance seems to be in good agreement that there will be a line of storms marching eastward from western Missouri in the afternoon, reaching eastern Missouri by early evening. With these high precipitation chances in guidance, feel it`s ok to go ahead and star TEMPOs in the terminal forecasts. Specifics for KSTL: VFR flight conditions are expected to continue at Lambert tonight. Low level wind shear looks to spread further east than previously forecast with 45kt or higher winds around 1500-2000ft, so have included it until 12Z. The guidance suite seems to be in good agreement that the storms over Iowa won`t spread south to affect Lambert through the morning, but there may be some widely scattered showers or storms developing during the late morning or early afternoon. Think coverage will be pretty low though so have not mentioned it in this update. The primary threat for thunderstorms will come during the early evening ahead of a cold front. While timing is still uncertain, it looks very likely that Lambert will receive a period of thunderstorms in the early evening followed by lighter rain later in the evening/overnight. Carney && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1022 PM EDT TUE MAY 13 2014 .SYNOPSIS... A FRONTAL BOUNDARY WILL REMAIN IN OUR VICINITY TODAY THROUGH THURSDAY. WHILE MUCH OF THE TIME WILL BE DRY, SCATTERED SHOWERS AND PERHAPS A FEW THUNDERSTORMS WILL BE POSSIBLE. A COLD FRONT WILL SLOWLY MOVE EAST ON FRIDAY WITH A SOAKING RAIN. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 1015 PM UPDATE...SCATTERED TO NUMEROUS CONVECTION CONTINUES JUST WEST OF BACKDOOR COLD FRONT, PRIMARILY IN THE FINGER LAKES REGION. THIS ACTIVITY IS EXPECTED TO SLOWLY LIFT NORTH AND EAST OVER THE NRN PTN OF THE CWA THROUGH LATE NIGHT. MUCH OF THE WESTERN CATSKILLS, BGM AREA AND NORTHEAST PA WILL REMAIN PRIMARILY DRY AS AIRMASS HERE IS STABLE UNDER COOL SE FLOW. WILL CONTINUE WITH LIKELY POPS OVER FINGER LAKES AND NRN CWA THROUGH 06Z THEN LOWER POPS INTO CHC/SLIGHT CHC FOR REMAINDER OF NIGHT EXCEPT DRY SE FA. 6 PM UPDATE...LATEST LOCAL RADAR IMAGERY SHOWS THE BACKDOOR COLD FRONT ABOUT TO MOVE THROUGH THE LOCAL BGM AREA. THIS FEATURE EXTENDS UP THROUGH THE WESTERN MOHAWK VALLEY AND SOUTH ACROSS THE WYOMING VALLEY. LOCATIONS EAST OF THE FEATURE ARE IN THE LOWER TO MIDDLE 70S WHILE OVER THE CENTRAL SOUTHERN TIER AND FINGER LAKES AREA ITS IN THE LOWER TO MIDDLE 80S. THIS BOUNDARY IS EXPECTED TO REACH THE CENTRAL SOUTHERN TIER AND EASTERN FINGER LAKES BEFORE STALLING AND MOVING BACK EAST. SCATTERED CONVECTION MAY FIRE ALONG THIS BOUNDARY UNTIL EARLY EVENING WHEN CAPE AND LOW LEVEL LAPSE RATES WILL LESSEN. CONVECTION OVER GEORGIAN BAY WHICH IS ASSOCIATED WITH COLD FRONT MAY MOVE INTO THE NRN PTN OF CWA LATE TONIGHT BUT BOUNDARY WILL SLOW OVERNIGHT AND CONVECTION WILL MOVE INTO A MUCH MORE STABLE ENVIRONMENT BY THEN. 3 PM UPDATE... A WEAK WARM FRONT IS ACROSS THE AREA WITH DEWPOINTS IN THE L60S IN THE WEST. AS THE WARM FRONT LIFTS NE WITH A WEAK WAVE A FEW SHOWERS AND MAYBE A TSTORM WILL GET GOING LATE TODAY AND THIS EVE. THE UL RIDGE ALSO MOVES THROUGH CREATING A DEEPER SOUTHERLY FLOW OF WARM AND MOIST AIR INTO THE CWA. WITH THE HIGH DEWPT TEMPS...MIN TEMPS WILL VARY WIDELY FROM U40S EAST TO A60 FAR WEST. DEWPTS DROP AS THE NIGHT GOES ON WITH THE EXIT OF THE WARM FRONT AND THE COLD FRONT NEARLY STATIONARY IN ERN MICIGAN. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... 3 PM UPDATE... WED AND THU WILL BE SIMILAR TO THE LAST 2 DAYS. WEAK FORCING AND MORE COVERAGE LATE IN THE DAY WITH DIURNAL HEATING. WED WILL BE BETTER THAN THU AS A COLD FRONT MOVES EAST INTO NW NY THEN LIFTS NORTH WED NGT. THU LITTLE FORCING AS WE WAIT FOR THE MAIN SHOW WHICH IS THE COLD FRONT. A SFC LOW WILL MOVE NORTH UP THE MISS VALLEY TO MICHIGAN THEN INTO QUEBEC AHEAD OF A DEEP DIGGING UPPER LEVEL LOW OVER THE MIDWEST. THIS STALLS OVER THE GREAT LAKES BUT KEEPS THE COLD FRONT MOVING THROUGH THE CWA FRIDAY. WITH THE FRONT WILL BE A BAND OF HEAVY RAIN OF WIDESPREAD 1 TO 2 INCHES. HIGHER AMOUNTS POSSIBLE WHICH COULD CAUSE MINOR ISOLATED HYDRO PROBLEMS. THIS RAIN HELPED BY GOOD LIFT AND FORCING AND PWATS OF 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL. DEWPTS 60S AND TROPICAL MOISTURE. WITH RIVERS NEAR NORMAL 1 TO 2 INCHES WOULD MOST LIKELY NOT CAUSE ANY FLOODING. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... 230 PM UPDATE... MED RANGE MODELS INDICATING CDFNT WL BE BISECTING CWA AT BEGINNING OF LONG TERM. HV GONE WITH LKLY/CATEGORICAL POPS EAST OF I-81 WITH CHC FURTHER BACK TO THE WEST. MAINLY SHOWERS EXPECTED FOLLOWING FROPA. REMAINDER OF LONG TERM WL FEATURE SHOWERS EACH PD COURTESY OF UPR LVL LOW HANGING BACK TO THE WEST. AS IS TYPICAL IN THESE CASES, EXPECT THAT AFT 12Z SATURDAY MOST OF THE SHOWERS WL BE OF THE MORE HIT AND MISS VARIETY WITH MOSTLY MISSES. THUS, THRU THE END OF THE LONG TERM WL KEEP 20-30 POPS OVR ENTIRE CWA. TEMPS DRG THE PD EXPECTED TO BE BLO NRML UNDER EXTENSIVE CLD CVR. FOLLOWED WPC GRIDS FOR THE LONG TERM WITH NO SIGNIFICANT DISCREPANCIES BTWN MED RANGE GUIDANCE. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... THE NAM AND RAP MODELS ARE BACKING OFF ON THE EXTENT OF THE PROJECTED MARINE LAYER FOR THE OVERNIGHT HOURS. OUR LATEST FORECAST INCLUDES A TEMPO PERIOD FOR MVFR TO BORDERLINE IFR CEILINGS FROM AVP UP TO ITH. MODEL SOUNDINGS SUGGEST A BURN OFF BETWEEN 13Z AND 15Z, THEN A PARTLY SUNNY AFTERNOON WITH A SCATTERED CU DECK BETWEEN 3500 AND 5000 FEET. THERE IS A SLIGHT CHANCE FOR AN AFTERNOON SHOWER OR THUNDERSTORM. OUTLOOK... WED NGT/THUR...MAINLY VFR, BUT POSSIBLE MVFR PDS IN SHOWERS AND THUNDERSTORMS. THUR NGT/FRI...MVFR AND POSSIBLE IFR RESTRICTIONS IN SHRA/TSRA AS COLD FRONT STALLS NEAR AREA. SAT...MVFR RESTRICTIONS POSSIBLE EARLY, BECOMING VFR DURING THE AFTERNOON. SUN...MVFR RESTRICTIONS POSSIBLE IN ISOLATED SHOWERS BUT MAINLY VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...TAC NEAR TERM...RRM/TAC SHORT TERM...TAC LONG TERM...PVN AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BUFFALO NY
740 PM EDT TUE MAY 13 2014 .SYNOPSIS... WARM AND INCREASINGLY HUMID AIR ACROSS THE REGION WILL MAINTAIN AN UNSTABLE ENVIRONMENT WHICH WILL SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE REGION THROUGH WEDNESDAY NIGHT. A COLD FRONT WILL THEN CROSS THE REGION LATER THURSDAY AND EARLY FRIDAY WITH LIKELY SHOWERS AND THUNDERSTORMS...SOME OF WHICH MAY BRING DOWNPOURS. && .NEAR TERM /THROUGH WEDNESDAY/... THROUGH 730 PM...THERE WAS SIGNIFICANT INSTABILITY ACROSS INTERIOR SECTIONS SOUTH OF LAKE ONTARIO WITH LAPS SHOWING AVERAGE CAPE VALUES IN THE 1000 TO 1500 J/KG RANGE. OVER THE PAST HOUR...RADAR SHOWS THUNDERSTORMS HAVE DEVELOPED RAPIDLY ACROSS INTERIOR PORTIONS WHERE THIS CAPE WAS IN PLACE. MEANWHILE...A WELL DEFINED AREA OF CONVECTION IS JUST UPSTREAM ACROSS CENTRAL LAKE ERIE AND SOUTHERN ONTARIO WITH THIS MOVING GRADUALLY EASTWARD. THIS IS FORECAST TO WEAKEN AS IT MOVES AHEAD OF UPPER LEVEL SUPPORT...BUT 18Z NAM AND HRRR GUIDANCE CONTINUE TO BRING ITS REMNANTS INTO OUR REGION MID- LATE EVENING. ALSO...AS OUTFLOWS SPREAD AHEAD OF THIS...SCATTERED SHOWERS AND THUNDERSTORMS HAVE BROKEN OUT AHEAD OF THIS. THIS SLUG OF MOISTURE IS LIKELY TO IMPACT WESTERN SECTIONS MID TO LATE EVENING...AND EASTERN SECTIONS LATE EVENING TO JUST AFTER MIDNIGHT. LATE TONIGHT...A SHOWERS OR THUNDERSTORM STILL CANNOT BE RULED OUT...BUT WHAT DOES FORM SHOULD BE MORE SCATTERED IN NATURE...WITH LESS AREAL COVERAGE. PRECIPITABLE WATER VALUES REMAIN QUITE HIGH...AROUND 1.3 TO 15 INCHES...SO HEAVIER RAINS ARE POSSIBLE. THE UPSIDE IS THAT THE STEERING WINDS WILL BE STRONGER TONIGHT WITH ABOUT 20 KNOTS AT 5KFT AND 35 KNOTS AT 10KFT...SO STORMS WILL NOT LINGER AS LONG OVER ANY INDIVIDUAL WATERSHED. THIS SAID...AREAS WHICH RECEIVED RECENT HEAVY RAINS WILL HAVE TO BE MONITORED VERY CLOSELY AS THIS PASSES THROUGH. OVERNIGHT LOWS WILL BE QUITE SUMMERLIKE FOR ONE MORE NIGHT WITH TEMPERATURES IN THE UPPER 50S TO LOWER 60S FOR THE EASTERN LAKE ONTARIO REGION AND LOWER TO MID 60S ELSEWHERE. WEDNESDAY WILL SEE THE CONTINUED CHANCE OF PRECIP...THE LOWER CHANCE POPS IN THE MORNING WILL INCREASE TO LOW LIKELY POPS IN THE AFTERNOON WITH INCREASED DAYTIME INSTABILITY. AGAIN...THE STALLED FRONT ACTING AS THE FOCUS FOR CONVECTIVE DEVELOPMENT. HIGH TEMPS WILL BE IN THE LOWER 70S ACROSS THE WEST WHERE THERE WILL BE A WINDSHIFT TO NORTHWESTERLY...AND COOLER AIR INFILTRATING DURING THE AFTERNOON...TO THE MID TO UPPER 70S ACROSS CENTRAL AND NORTHERN NY WHERE COOLER AIR WILL BE DISPLACED BY A WARM ADVECTIVE PATTERN ON SOUTHERLY WINDS. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... VERY UNSETTLED WEATHER WILL REMAIN OVER OUR REGION DURING THIS PERIOD...AS A DEEP TROUGH BASED OVER THE MISSISSIPPI VALLEY WILL MAINTAIN A RICH MOISTURE PLUME THAT WILL EXTEND FROM THE GULF OF MEXICO TO QUEBEC. THIS PROLONGED FEED OF SUB TROPICAL AIR WILL CONTAIN PWAT VALUES OF 1.25 TO 1.5 INCHES...WHICH WILL KEEP THE THREAT OF EXCESSIVE RAINS IN PLACE. THE GREATEST RISK FOR WIDESPREAD SIGNIFICANT RAINFALL WILL BE DURING THE SECOND HALF OF THURSDAY INTO FRIDAY. THE DETAILS... AN INVERTED SFC TROUGH EXTENDING FROM THE TENNESSEE VALLEY TO THE LOWER GREAT LAKES WEDNESDAY EVENING WILL BECOME ENERGIZED OVERNIGHT AS A STRONG SHORTWAVE WILL LIFT OUT OF THE LOWER OHIO VALLEY. THIS WILL ENCOURAGE A WAVE WITHIN THE TROUGH TO DEVELOP INTO A FAIRLY WELL ORGANIZED AREA OF LOW PRESSURE...WHICH IN TURN WILL INCREASE THE SOUTHERLY LOW LEVEL FLOW OVER OUR FORECAST AREA AND TIGHTEN A BAROCLINIC ZONE OVER SOUTHERN ONTARIO. WHILE THERE MAY BE SOME SHOWERS AND THUNDERSTORMS OVER OUR REGION AS A RESULT...THE BULK OF THE NIGHT SHOULD BE RAIN FREE WITH THE BULK OF THE PCPN STAYING WEST OF THE IAG RIVER. OTHERWISE...WE SHOULD EXPECT A VERY MILD AND SOMEWHAT HUMID NIGHT FOR MID MAY WITH MINS GENERALLY IN THE MID 60S. AS THE AXIS OF A 100KT H25 JET WITH ITS UPPER LEVEL LIFT PUSHES EAST ACROSS MICHIGAN AND OHIO ON THURSDAY...AND THE AFOREMENTIONED SFC LOW LIFTS ACROSS THE LOWER GREAT LAKES...MORE WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE GENERATED. THIS WILL ESPECIALLY BE THE CASE WEST OF THE GENESEE VALLEY WHERE SOME HEAVY RAIN WILL BE POSSIBLE. AS THE INITIAL SFC LOW WILL LIFT NORTH OF OUR REGION ON THURSDAY NIGHT...A QUASI-STATIONARY FRONTAL BOUNDARY WILL PUSH VERY SLOWLY TO THE EAST ACROSS OUR REGION. MEANWHILE...A 150KT JETLET IS EXPECTED TO RACE TO THE NORTH ACROSS THE UPPER GREAT LAKES. THE LIFT PROVIDED BY THIS JET...COUPLED WITH THE CONVERGENCE IN PROXIMITY OF THE FRONTAL BOUNDARY...WILL PRODUCE MODERATE TO HEAVY SHOWERS AND POSSIBLY SOME THUNDERSTORMS WITHIN THE SUB TROPICAL AIRMASS. WILL CONTINUE TO USE CAT POPS FOR THIS PERIOD. AVERAGE BASIN RAINFALL THURSDAY NIGHT IS FORECAST TO RANGE FROM A QUARTER INCH EAST OF LK ONTARIO TO AN INCH OR MORE ACROSS MOST OF THE WESTERN COUNTIES. LOCAL AMOUNTS IN EXCESS OF 1.5 INCHES WILL BE POSSIBLE OVER THE SOUTHERN TIER. THE SLOW MOVING FRONTAL BOUNDARY WILL THEN SLOWLY CROSS THE FINGER LAKES AND EASTERN LAKE ONTARIO REGIONS DURING THE DAY FRIDAY. THIS WILL KEEP THE THREAT FOR SIGNIFICANT RAINS IN PLACE FOR THE EASTERN HALF OF OUR FORECAST AREA WHERE BASIN AVERAGE RAINFALL IS FORECAST TO BE IN THE VICINITY OF ONE INCH. MEANWHILE...LIGHTER SHOWERS OVER THE FAR WESTERN COUNTIES WILL TAPER OFF DURING THE COURSE OF THE AFTERNOON. ONE LAST WAVE OF LOW PRESSURE WILL TRACK NORTH ALONG THE SLOW MOVING FRONTAL BOUNDARY FRIDAY NIGHT...AND THIS WILL FURTHER SLOW ITS EASTWARD PROGRESSION...IF NOT STALLING IT FOR SOME 6 HOURS. WHILE THE MOST UNSTABLE AIR AND DEEPEST MOISTURE FIELD AHEAD OF THE FRONT WILL PUSH EAST ACROSS THE ADIRONDACKS...WIDESPREAD SHOWERS AND THE CHANCE FOR LEFTOVER THUNDERSTORMS WILL REMAIN OVER THE EASTERN LAKE ONTARIO REGION. && .LONG TERM /SATURDAY THROUGH TUESDAY/... IT WILL BE COOLER...AND FOR THE MOST PART...DRIER THAN THE WEEK LEADING UP TO THIS PERIOD AS A DEAMPLIFICATION IN THE LONGWAVE PATTERN OVER NORTH AMERICA WILL RESULT IN OUR BOUNDARY LAYER WINDS COMING OUT OF THE EASTERN HALF OF CANADA VERSUS THE GULF OF MEXICO. THAT IS NOT TO SAY THAT THERE WILL NOT BE THE CHANCE FOR SOME NUISANCE SHOWERS THOUGH...AS THE LONGWAVE TROUGH THAT WAS RESPONSIBLE FOR THE SIGNIFICANT RAINS DURING THE WEEK WILL EVOLVE INTO A CLOSED LOW IN THE VCNTY OF NEW JERSEY. A CORRESPONDING SFC LOW ON THE EAST SIDE OF THIS CLOSED LOW IS FORECAST BY BOTH THE ECMWF AND GFS ENSEMBLE PACKAGES TO ROTATE NORTHWEST TO THE NEW ENGLAND COAST. ATLANTIC MOISTURE ASSOCIATED WITH THIS FEATURE WOULD THEN CIRCULATE BACK ACROSS OUR REGION...WITH SOME SHOWERS POSSIBLE ACROSS THE NORTH COUNTRY ON SUNDAY...THEN ACROSS ALL OF OUR FORECAST AREA ON MONDAY. RIDGING IS THEN EXPECTED TO BUILD ACROSS THE LOWER GREAT LAKES IN THE WAKE OF THE CLOSED LOW ON TUESDAY. THIS SHOULD PROMOTE MAINLY DRY WEATHER ACROSS WESTERN NEW YORK WHILE A LOW CHC FOR RESIDUAL SHOWERS WILL BE FOUND FURTHER EAST. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AN AREA OF THUNDERSTORMS IS GRADUALLY APPROACHING FROM THE WEST AT 00Z...WITH SCATTERED SHOWERS AND THUNDERSTORMS OUT JUST AHEAD OF THIS. EXPECT A 2-3 HOUR PERIOD OF THUNDERSTORMS AT MOST TAF SITES LATE THIS EVENING. THE LINE UPSTREAM SHOULD WEAKEN AND VARY IN STRENGTH BASED ON SUBTLE BOUNDARIES ACROSS OUR REGION SO THERE IS ONLY LOW TO MODERATE CONFIDENCE IN TIMING OF THE THUNDERSTORMS IN THE TAFS. EXPECT CONVECTION TO EXIT EAST 06-08Z WITH MORE SCATTERED ACTIVITY. CONDITIONS WILL BE VFR OUTSIDE OF THUNDERSTORMS. ON WEDNESDAY...EXPECT MAINLY VFR CONDITIONS WITH SCATTERED SHOWERS IN THE MORNING. THE EXCEPTION IS IN WESTERN AREAS...WHERE MOIST DEW POINTS WILL INTERACT WITH THE COOL LAKE WATERS AND POSSIBLY BRING MFR OR LOWER CIGS. OUTLOOK... WEDNESDAY NIGHT AND THURSDAY...VFR/MVFR WITH SCATTERED TO EVENTUALLY MORE NUMEROUS SHOWERS AND POSSIBLE THUNDERSTORMS. THURSDAY NIGHT AND FRIDAY...MVFR/POSSIBLE IFR IN OCCASIONAL SHOWERS AND POSSIBLE THUNDERSTORMS. RAIN MAY BE HEAVY AT TIMES OVERNIGHT. SATURDAY...MAINLY VFR WITH A CHANCE OF SHOWERS. SUNDAY...VFR. && .MARINE... RELATIVELY LIGHT WINDS WILL CONTINUE THROUGH WEDNESDAY AS A NEARLY STATIONARY FRONTAL BOUNDARY REMAINS DRAPED ACROSS THE LOWER GREAT LAKES. A SLOW MOVING FRONTAL BOUNDARY WILL THEN MOVE INTO THE REGION AND STALL OUT ON WEDNESDAY...WITH A MODEST INCREASE IN WINDS ACCOMPANYING ITS APPROACH. WINDS AND WAVES WILL LIKELY REMAIN BELOW SMALL CRAFT CRITERIA THROUGH FRIDAY. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...WCH NEAR TERM...APFFEL/WCH SHORT TERM...RSH LONG TERM...RSH AVIATION...APFFEL MARINE...APFFEL/THOMAS/WCH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1103 PM EDT TUE MAY 13 2014 .SYNOPSIS... HIGH PRESSURE OFFSHORE WILL MAINTAIN ABOVE NORMAL TEMPERATURES THROUGH WEDNESDAY. A COLD FRONT WILL APPROACH ON THURSDAY AND MOVE ACROSS THE AREA AND OFFSHORE ON FRIDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED THURSDAY AFTERNOON AND NIGHT...PERHAPS LINGERING INTO FRIDAY FOR PORTIONS OF THE AREA. MUCH COOLER AND DRIER CONDITIONS ARE EXPECTED FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 1045 PM TUESDAY...THE WELL AMPLIFIED UPPER RIDGING WILL SLOWLY PROGRESS EASTWARD TONIGHT...WITH MODELS INDICATING THE NORTH TO SOUTH UPPER RIDGE AXIS NEARLY OVERHEAD BY WEDNESDAY DAYBREAK. SUBSIDENCE UNDERNEATH THIS UPPER RIDGING HAS KEPT THE DIURNALLY INDUCED/DRIVEN CONVECTION TO A MINIMUM...INCLUDING ALONG THE INLAND PROGRESSIVE SEA BREEZE BOUNDARY. LATEST HRRR HOURLY REFLECTIVITY MODEL RUN HAS FINALLY CAUGHT UP WITH REALITY AND NOW INDICATES NO PCPN ACROSS THE FA FOR THE REMAINDER OF THE NIGHT. SKIES OVERALL WILL REMAIN CLEAR OVERNIGHT. NAMBUFR SOUNDINGS INDICATE A WEAK SFC BASED INVERSION TO OCCUR OVERNIGHT BUT NOT ALL THAT IMPRESSIVE FOR A WIDESPREAD FOG OR LOW STRATUS OCCURRENCE. FAMOUS LAST WORDS. AS A RESULT...HAVE KEPT FOG AND LOW STRATUS TO A MINIMUM DURING THE OVERNIGHT PERIOD. SFC WINDS PROGGED TO REMAIN JUST ACTIVE ENOUGH...5 MPH OR LESS. USING THE PREVIOUS NIGHT MIN TEMPS AS GUIDANCE AND PERSISTENCE...STAYED JUST ABOVE LAST NIGHTS MINS. PREVIOUS DISCUSSION.................................... AS OF 300 PM TUESDAY...ELONGATED AREA OF HIGH PRESSURE CENTERED SEVERAL HUNDRED MILES OFF THE SOUTH CAROLINA COAST IS EXTENDING BACK TOWARDS THE SOUTHEAST...WITH A RIDGE AXIS ALIGNED E-W JUST SOUTH OF CHARLESTON, SC. THIS IS PUMPING WARM SW RETURN FLOW ACROSS THE ILM CWA. AT THE SAME TIME...HIGHLY AMPLIFIED 500MB RIDGE IS DRIFTING EAST...REMAINING NEARLY OVERHEAD THROUGH TONIGHT. THESE TWO FEATURES TOGETHER ARE CREATING A TYPICAL SUMMERTIME PATTERN...WITH TEMPS ONCE AGAIN RISING TO AROUND 90 LOCALLY...4-8 DEGREES ABOVE NORMAL. THE COMBINATION OF HOT TEMPS AND DEWPOINT VALUES IN THE MID/UPR 60S HAS ONCE AGAIN ALLOWED WIDESPREAD DIURNAL CU TO DEVELOP ACROSS THE AREA...WITH THE MOST CONGESTED FIELDS FOCUSED ALONG THE SEA BREEZE. HAVE CONTINUED WITH A SMALL AREA OF 20 POP FOR ISOLATED SHOWERS ALONG THE SEA BREEZE FOR THE NEXT FEW HOURS...AND A FEW REFLECTIVITY ECHOES HAVE APPEARED THIS AFTN...BUT THE CHANCE FOR ANY MEANINGFUL SHOWERS ANYWHERE IS DECREASING RAPIDLY. AS EXPECTED...COVERAGE HAS BEEN MUCH LESS THAN YESTERDAY THANKS TO MORE SUBSIDENCE ALOFT AND DRIER MID-LEVEL AIR. ANY CONVECTION WILL WANE TOWARDS...AND ESPECIALLY AFTER...SUNSET...AS WILL ANY DIURNALLY FORCED CLOUD COVER. ALTHOUGH SKY CONDITIONS WILL CLEAR TONIGHT...LIGHT SW WINDS WILL MAINTAIN SOME MIXING...AND THUS LOWS WILL FALL ONLY TO AROUND 70 AT THE COAST...COOLING TO THE MID 60S WELL INLAND...AS ANOTHER ABOVE NORMAL NIGHT OCCURS LOCALLY. THE AIR MASS IS PRIMARILY UNCHANGED FROM LAST NIGHT...SO PATCHY FOG WILL ONCE AGAIN DEVELOP...BUT WIDESPREAD OR DENSE FOG IS NOT ANTICIPATED. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...WEDNESDAY WILL BE ONE LAST WARM AND RAIN FREE DAY BEFORE SOME SUBSTANTIAL CHANGES GET UNDERWAY. EASTWARD MOVING UPPER RIDGE STILL OVER THE AREA ENOUGH ON WEDNESDAY TO KEEP A CAP ON CONVECTION ALONG THE COAST. AT THE SURFACE WEST ATLANTIC HIGH PRESSURE WILL WEAKEN FOR A LIGHT AND VARIABLE FLOW THAT WILL ALLOW GOOD INLAND PROGRESS OF A SEA BREEZE THAT WILL TAPER THE HEAT ANYWHERE EAST OF ITS PROGRESS. A SHARPENING AND PHASING TROUGH OVER THE NATIONS MIDSECTION ALONG WITH ITS ATTENDANT COLD FRONT WILL MAKE FOR SOME DEEP MOISTURE ADVECTION FROM WEST TO EAST...KICKING IN OVER WESTERN ZONES LATER WEDNESDAY NIGHT. THE RAPID WEST TO EAST INC IN CLOUDS WILL THEN BE FOLLOWED BY RAIN CHANCES THAT INCREASE IN THE SAME FASHION ON THURSDAY AS HEIGHT FALLS OVERSPREAD THE AREA. THE MOST UNSETTLED WEATHER COMES THURSDAY EVENING AND NIGHT HOWEVER AS ENERGY BELLYING UNDER THE SLIGHTLY NEGATIVELY TILTED UPPER WAVE BRINGS A SURFACE LOW UP THE COAST. MODERATE TO HEAVY RAINFALL SEEMS A NEAR CERTAINTY...THE SEVERE WEATHER THREAT IS A BIT HIGHER TO DIAGNOSE. LOW LEVEL WIND FIELDS WILL BE STRONG INCLUDING IN THE LOWER LEVELS. DEEP LAYER INSTABILITY IS LACKING FOR THE MOST PART THURSDAY NIGHT...BUT EVEN ABSENT DEEP CONVECTION THERE MAY BE STRONG ENOUGH FORCING FOR THE STRAY TORNADO SPIN UP GIVEN VERY STRONG SRH IN BOTH THE 0-3KM AND 0-1KM LAYERS. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...A NORTH-SOUTH ORIENTED COLD FRONT WILL BE DRAPED ACROSS EASTERN NC EARLY FRIDAY...WITH THE BOUNDARY EXPECTED TO PUSH OFF THE SOUTHEAST NC COAST DURING THE MORNING HOURS. ONGOING WIDESPREAD CONVECTIVE ACTIVITY EARLY FRIDAY WILL BE ENHANCED IN THE VICINITY OF A SURFACE WAVE OF LOW PRESSURE LIFTING ACROSS THE CWA. CONVECTION WILL SHIFT NORTHEAST OF THE AREA WITH POPS TRENDING DOWN FROM SOUTHWEST TO NORTHEAST DURING THE 12-18 UTC WINDOW. THE SYNOPTIC PATTERN WILL BE SLOW TO PROGRESS DURING THE FRI-TUE TIME FRAME...SO THE WEAK SURFACE HIGH PRESSURE THAT BUILDS ACROSS THE CAROLINAS IN THE WAKE OF THE COLD FRONT WILL PERSIST THROUGH THE PERIOD. TEMPS WILL REMAIN A FEW DEGREES SHY OF CLIMO EACH DAY. MODELS SUGGEST SOME MOISTURE ROTATING AROUND THE BASE OF THE MID-UPPER TROUGH SUNDAY WHICH WOULD RESULT IN SOME ENHANCED CLOUDINESS. IMPULSES CIRCULATING THROUGH THE MID-LEVEL FLOW MAY AFFECT THE AREA SUN-TUE AND THEREFORE CAN`T RULE OUT PRECIP POTENTIAL ALTOGETHER...BUT CHANCES WILL REMAIN LOW. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... AS OF 00Z...THE SEA BREEZE MOVED WELL INLAND THIS EVENING TODAY. ISOLATED SHOWERS THAN OCCURRED THIS AFTERNOON HAVE DISSIPATED LOCALLY...BUT ARE STILL DEVELOPING WELL N OF KLBT. SINCE THE AIRMASS REMAINS RELATIVELY UNCHANGED THERE SHOULD THE SAME POTENTIAL FOR FOG/ST AS LAST NIGHT. CONFIDENCE IS SLIGHTLY HIGHER TERMINALS WILL BE AFFECTED BASED ON GREATER LOW LEVEL MOISTURE INDICATED IN GFS TIME HEIGHT ANALYSIS. TIME OF OCCURRENCE SHOULD BE GENERALLY 08-12Z. LATEST GFS MOS GUIDANCE IS SUGGESTING IFR OR LESS CONDITIONS AT ALL TERMINALS. MVFR CIGS ARE POSSIBLE 12-15Z WITH VFR EXPECTED THEREAFTER. WINDS WEDNESDAY WILL BE MORE SE-S THAN TODAY. NO PRECIPITATION IS EXPECTED. EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR SHRA/ISOLATED TSRA WITH MVFR/IFR THURS AFTN THROUGH FRI MORNING. VFR SAT AND SUN. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1045 PM TUESDAY...RIDGING ACROSS THE WATERS FROM THE SFC HIGH CENTERED OFFSHORE AND EAST OF THE CAROLINAS...WILL PERSIST OVERNIGHT INTO WEDNESDAY. THE POSITIONING OF THE SFC RIDGE AXIS WILL DETERMINE WIND DIRECTIONS. NORTH OF THE RIDGE AXIS...LOOK FOR SSW-SW DIRECTIONS...SOUTH OF THE AXIS LOOK FOR SSE-SSW DIRECTIONS. THE SFC PRESSURE GRADIENT REMAINS LOOSE AND THUS WIND SPEEDS IN GENERAL AROUND 10 KT OR LESS. EXCEPTION 10 TO 15 KT NEAR SHORE THROUGH THIS EVENING DUE TO THE DEMISE OF THE SEA BREEZE CIRCULATION. SIGNIFICANT SEAS WILL RUN 2 TO 3 FT. WITH A DECENT FETCH IN PLACE AND EXTENDING OFFSHORE...A SOLID 2 FOOT SE PSEUDO GROUND SWELL EXHIBITING 7 TO 8 SECOND PERIODS WILL AFFECT THE AREA WATERS. COMBINED WITH LOCALLY PRODUCED WIND-WAVES...A SOLID 2 TO 3 FOOT SIGNIFICANT SEAS WILL BE FORECAST. PREVIOUS DISCUSSION.................................... AS OF 300 PM TUESDAY...HIGH PRESSURE ANCHORED OFFSHORE REMAINS IN PLACE...RIDGING BACK TOWARDS THE COAST. THIS IS PRODUCING SW WINDS AROUND 10 KTS OVER THE COASTAL WATERS...EXCEPT WITHIN THE NEAR-SHORE SEA BREEZE WHERE SOUTHERLY WINDS UP TO 15 KTS EXIST. THESE WILL ONCE AGAIN BECOME A UNIFORM SSW WIND AROUND 10 KTS OVERNIGHT. WAVE HEIGHTS WILL BE 2-3 FT THROUGH THE PERIOD...WITH A SE GROUND SWELL AND S/SW WIND WAVE COMPRISING THE SPECTRUM. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...QUITE A BIT OF DICHOTOMY BETWEEN THE PERIODS OF THE SHORT TERM. STARTING OFF WEDNESDAY WITH A VERY LIGHT WIND OUT OF THE SOUTH AS HIGH PRESSURE WILL BE FOUND ACROSS MUCH OF THE WESTERN ATLANTIC BUT WITH A CENTER REMOVED NORTH AND EAST OF WHAT IS MORE TYPICAL DURING THE SPRING. THE WIND WAVES WILL BE LIGHT BUT WNA GUIDANCE SHOWING SOME SOUTHEASTERLY SWELL ENERGY. SOUTHEASTERLY FLOW ON THURSDAY WILL SIMILARLY BE FAIRLY BENIGN THROUGH THE DAY BUT WILL SHOW A STEEP RAMP UP THOUGH THE EVENING AND INTO THE OVERNIGHT HOURS. A VERY STRONG UPPER LEVEL STORM SYSTEM WILL BE GETTING CARVED OUT OVER THE MID SECTION OF THE NATION. A COLD FRONT WILL BE APPROACHING FROM THE WEST WHILE LOW PRESSURE STRENGTHENS ALONG THE BOUNDARY OVER THE WEST COAST OF FLORIDA. AS THIS WAVE MOVES UP ALONG THE SOUTHEAST COAST THE WINDS WILL BECOME QUITE STRONG AND A SMALL CRAFT ADVISORY IS EXPECTED. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 3 PM TUESDAY...DEPENDING ON THE EXACT TIMING OF THE FRONTAL PASSAGE EARLY FRIDAY...SMALL CRAFT ADVISORY CONDITIONS MAY STILL BE ONGOING FRIDAY MORNING...ESPECIALLY FROM CAPE FEAR NORTH. HOWEVER CONDITIONS WILL IMPROVE DURING THE MORNING HOURS AS WEAK HIGH PRESSURE BUILDS IN. WINDS WILL DIMINISH TO 15 KT BY MIDDAY FRIDAY AND SHIFT TO AN OFFSHORE TRAJECTORY. THE PRESSURE GRADIENT WILL CONTINUE TO WEAKEN WITH SPEEDS EXPECTED TO FALL TO 10 KT OR LESS SATURDAY-SUNDAY. BY SUNDAY...SOME VARIABILITY IN THE WIND DIRECTION CAN BE EXPECTED AS SPEEDS LOOK TO DROP BELOW 10 KT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...DCH/JDW SHORT TERM...MBB LONG TERM...CRM AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
719 PM EDT TUE MAY 13 2014 .SYNOPSIS... HIGH PRESSURE OFFSHORE WILL MAINTAIN ABOVE NORMAL TEMPERATURES THROUGH WEDNESDAY. A COLD FRONT WILL APPROACH ON THURSDAY AND MOVE ACROSS THE AREA AND OFFSHORE ON FRIDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED THURSDAY AFTERNOON AND NIGHT...PERHAPS LINGERING INTO FRIDAY FOR PORTIONS OF THE AREA. MUCH COOLER AND DRIER CONDITIONS ARE EXPECTED FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 700 PM TUESDAY...THE WELL AMPLIFIED UPPER RIDGING WILL BEGIN TO PROGRESS EASTWARD TONIGHT...WITH MODELS INDICATING THE NORTH TO SOUTH UPPER RIDGE AXIS NEARLY OVERHEAD BY WEDNESDAY DAYBREAK. SUBSIDENCE UNDERNEATH THIS UPPER RIDGING HAS KEPT THE DIURNALLY INDUCED CONVECTION TO A MINIMUM...INCLUDING THE INLAND PROGRESSIVE SEA BREEZE BNDRY. LATEST HRRR HOURLY REFLECTIVITY MODEL RUN REMAINS A BIT OVERDONE WITH THE PCPN CHANCES ACROSS THE FA. OTHER THAN FEW/SCATTERED DIURNALLY DRIVEN CU ACROSS THE FA...SKIES WILL OVERALL BECOME CLEAR AFTER SUNSET. NAMBUFR SOUNDINGS INDICATE A WEAK SFC BASED INVERSION TO OCCUR OVERNIGHT BUT NOT ALL THAT IMPRESSIVE FOR A WIDESPREAD FOG OR LOW STRATUS OCCURRENCE. AS A RESULT...HAVE KEPT FOG TO A MINIMUM DURING THE OVERNIGHT PERIOD. HAVE TWEAKED MINS BY 1 TO 2 DEGREES EITHER SIDE OF THE CURRENT MIN FORECAST...USING THE PREVIOUS NIGHT MIN TEMPS AS GUIDANCE...IE. PERSISTENCE. PREVIOUS DISCUSSION............................................... AS OF 300 PM TUESDAY...ELONGATED AREA OF HIGH PRESSURE CENTERED SEVERAL HUNDRED MILES OFF THE SOUTH CAROLINA COAST IS EXTENDING BACK TOWARDS THE SOUTHEAST...WITH A RIDGE AXIS ALIGNED E-W JUST SOUTH OF CHARLESTON, SC. THIS IS PUMPING WARM SW RETURN FLOW ACROSS THE ILM CWA. AT THE SAME TIME...HIGHLY AMPLIFIED 500MB RIDGE IS DRIFTING EAST...REMAINING NEARLY OVERHEAD THROUGH TONIGHT. THESE TWO FEATURES TOGETHER ARE CREATING A TYPICAL SUMMERTIME PATTERN...WITH TEMPS ONCE AGAIN RISING TO AROUND 90 LOCALLY...4-8 DEGREES ABOVE NORMAL. THE COMBINATION OF HOT TEMPS AND DEWPOINT VALUES IN THE MID/UPR 60S HAS ONCE AGAIN ALLOWED WIDESPREAD DIURNAL CU TO DEVELOP ACROSS THE AREA...WITH THE MOST CONGESTED FIELDS FOCUSED ALONG THE SEA BREEZE. HAVE CONTINUED WITH A SMALL AREA OF 20 POP FOR ISOLATED SHOWERS ALONG THE SEA BREEZE FOR THE NEXT FEW HOURS...AND A FEW REFLECTIVITY ECHOES HAVE APPEARED THIS AFTN...BUT THE CHANCE FOR ANY MEANINGFUL SHOWERS ANYWHERE IS DECREASING RAPIDLY. AS EXPECTED...COVERAGE HAS BEEN MUCH LESS THAN YESTERDAY THANKS TO MORE SUBSIDENCE ALOFT AND DRIER MID-LEVEL AIR. ANY CONVECTION WILL WANE TOWARDS...AND ESPECIALLY AFTER...SUNSET...AS WILL ANY DIURNALLY FORCED CLOUD COVER. ALTHOUGH SKY CONDITIONS WILL CLEAR TONIGHT...LIGHT SW WINDS WILL MAINTAIN SOME MIXING...AND THUS LOWS WILL FALL ONLY TO AROUND 70 AT THE COAST...COOLING TO THE MID 60S WELL INLAND...AS ANOTHER ABOVE NORMAL NIGHT OCCURS LOCALLY. THE AIR MASS IS PRIMARILY UNCHANGED FROM LAST NIGHT...SO PATCHY FOG WILL ONCE AGAIN DEVELOP...BUT WIDESPREAD OR DENSE FOG IS NOT ANTICIPATED. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...WEDNESDAY WILL BE ONE LAST WARM AND RAIN FREE DAY BEFORE SOME SUBSTANTIAL CHANGES GET UNDERWAY. EASTWARD MOVING UPPER RIDGE STILL OVER THE AREA ENOUGH ON WEDNESDAY TO KEEP A CAP ON CONVECTION ALONG THE COAST. AT THE SURFACE WEST ATLANTIC HIGH PRESSURE WILL WEAKEN FOR A LIGHT AND VARIABLE FLOW THAT WILL ALLOW GOOD INLAND PROGRESS OF A SEA BREEZE THAT WILL TAPER THE HEAT ANYWHERE EAST OF ITS PROGRESS. A SHARPENING AND PHASING TROUGH OVER THE NATIONS MIDSECTION ALONG WITH ITS ATTENDANT COLD FRONT WILL MAKE FOR SOME DEEP MOISTURE ADVECTION FROM WEST TO EAST...KICKING IN OVER WESTERN ZONES LATER WEDNESDAY NIGHT. THE RAPID WEST TO EAST INC IN CLOUDS WILL THEN BE FOLLOWED BY RAIN CHANCES THAT INCREASE IN THE SAME FASHION ON THURSDAY AS HEIGHT FALLS OVERSPREAD THE AREA. THE MOST UNSETTLED WEATHER COMES THURSDAY EVENING AND NIGHT HOWEVER AS ENERGY BELLYING UNDER THE SLIGHTLY NEGATIVELY TILTED UPPER WAVE BRINGS A SURFACE LOW UP THE COAST. MODERATE TO HEAVY RAINFALL SEEMS A NEAR CERTAINTY...THE SEVERE WEATHER THREAT IS A BIT HIGHER TO DIAGNOSE. LOW LEVEL WIND FIELDS WILL BE STRONG INCLUDING IN THE LOWER LEVELS. DEEP LAYER INSTABILITY IS LACKING FOR THE MOST PART THURSDAY NIGHT...BUT EVEN ABSENT DEEP CONVECTION THERE MAY BE STRONG ENOUGH FORCING FOR THE STRAY TORNADO SPIN UP GIVEN VERY STRONG SRH IN BOTH THE 0-3KM AND 0-1KM LAYERS. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...A NORTH-SOUTH ORIENTED COLD FRONT WILL BE DRAPED ACROSS EASTERN NC EARLY FRIDAY...WITH THE BOUNDARY EXPECTED TO PUSH OFF THE SOUTHEAST NC COAST DURING THE MORNING HOURS. ONGOING WIDESPREAD CONVECTIVE ACTIVITY EARLY FRIDAY WILL BE ENHANCED IN THE VICINITY OF A SURFACE WAVE OF LOW PRESSURE LIFTING ACROSS THE CWA. CONVECTION WILL SHIFT NORTHEAST OF THE AREA WITH POPS TRENDING DOWN FROM SOUTHWEST TO NORTHEAST DURING THE 12-18 UTC WINDOW. THE SYNOPTIC PATTERN WILL BE SLOW TO PROGRESS DURING THE FRI-TUE TIME FRAME...SO THE WEAK SURFACE HIGH PRESSURE THAT BUILDS ACROSS THE CAROLINAS IN THE WAKE OF THE COLD FRONT WILL PERSIST THROUGH THE PERIOD. TEMPS WILL REMAIN A FEW DEGREES SHY OF CLIMO EACH DAY. MODELS SUGGEST SOME MOISTURE ROTATING AROUND THE BASE OF THE MID-UPPER TROUGH SUNDAY WHICH WOULD RESULT IN SOME ENHANCED CLOUDINESS. IMPULSES CIRCULATING THROUGH THE MID-LEVEL FLOW MAY AFFECT THE AREA SUN-TUE AND THEREFORE CAN`T RULE OUT PRECIP POTENTIAL ALTOGETHER...BUT CHANCES WILL REMAIN LOW. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AS OF 00Z...THE SEA BREEZE MOVED WELL INLAND THIS EVENING TODAY. ISOLATED SHOWERS THAN OCCURRED THIS AFTERNOON HAVE DISSIPATED LOCALLY...BUT ARE STILL DEVELOPING WELL N OF KLBT. SINCE THE AIRMASS REMAINS RELATIVELY UNCHANGED THERE SHOULD THE SAME POTENTIAL FOR FOG/ST AS LAST NIGHT. CONFIDENCE IS SLIGHTLY HIGHER TERMINALS WILL BE AFFECTED BASED ON GREATER LOW LEVEL MOISTURE INDICATED IN GFS TIME HEIGHT ANALYSIS. TIME OF OCCURRENCE SHOULD BE GENERALLY 08-12Z. LATEST GFS MOS GUIDANCE IS SUGGESTING IFR OR LESS CONDITIONS AT ALL TERMINALS. MVFR CIGS ARE POSSIBLE 12-15Z WITH VFR EXPECTED THEREAFTER. WINDS WEDNESDAY WILL BE MORE SE-S THAN TODAY. NO PRECIPITATION IS EXPECTED. EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR SHRA/ISOLATED TSRA WITH MVFR/IFR THURS AFTN THROUGH FRI MORNING. VFR SAT AND SUN. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 700 PM TUESDAY...RIDGING ACROSS THE WATERS FROM THE SFC HIGH CENTERED OFFSHORE AND EAST OF THE CAROLINAS...WILL PERSIST OVERNIGHT INTO WEDNESDAY. THE POSITIONING OF THE SFC RIDGE AXIS WILL DETERMINE WIND DIRECTIONS. NORTH OF THE RIDGE AXIS LOOK FOR SSW-SW DIRECTIONS...SOUTH OF THE AXIS LOOK FOR SSE-SSW DIRECTIONS. THE SFC PRESSURE GRADIENT REMAINS LOOSE AND THUS WIND SPEEDS IN GENERAL AROUND 10 KT OR LESS. EXCEPTION 10 TO 15 KT NEAR SHORE THIS EVENING DUE TO THE MESOSCALE SEA BREEZE CIRCULATION. SIGNIFICANT SEAS WILL RUN 2 TO 3 FT. WITH A DECENT FETCH IN PLACE AND EXTENDING OFFSHORE...A SOLID 2 FOOT SE PSEUDO GROUND SWELL EXHIBITING 7 TO 8 SECOND PERIODS WILL AFFECT THE AREA WATERS. COMBINED WITH LOCALLY PRODUCED WIND-WAVES...A SOLID 2 TO 3 FOOT SIGNIFICANT SEAS TO OCCUR. PREVIOUS DISCUSSION............................................... AS OF 300 PM TUESDAY...HIGH PRESSURE ANCHORED OFFSHORE REMAINS IN PLACE...RIDGING BACK TOWARDS THE COAST. THIS IS PRODUCING SW WINDS AROUND 10 KTS OVER THE COASTAL WATERS...EXCEPT WITHIN THE NEAR-SHORE SEA BREEZE WHERE SOUTHERLY WINDS UP TO 15 KTS EXIST. THESE WILL ONCE AGAIN BECOME A UNIFORM SSW WIND AROUND 10 KTS OVERNIGHT. WAVE HEIGHTS WILL BE 2-3 FT THROUGH THE PERIOD...WITH A SE GROUND SWELL AND S/SW WIND WAVE COMPRISING THE SPECTRUM. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...QUITE A BIT OF DICHOTOMY BETWEEN THE PERIODS OF THE SHORT TERM. STARTING OFF WEDNESDAY WITH A VERY LIGHT WIND OUT OF THE SOUTH AS HIGH PRESSURE WILL BE FOUND ACROSS MUCH OF THE WESTERN ATLANTIC BUT WITH A CENTER REMOVED NORTH AND EAST OF WHAT IS MORE TYPICAL DURING THE SPRING. THE WIND WAVES WILL BE LIGHT BUT WNA GUIDANCE SHOWING SOME SOUTHEASTERLY SWELL ENERGY. SOUTHEASTERLY FLOW ON THURSDAY WILL SIMILARLY BE FAIRLY BENIGN THROUGH THE DAY BUT WILL SHOW A STEEP RAMP UP THOUGH THE EVENING AND INTO THE OVERNIGHT HOURS. A VERY STRONG UPPER LEVEL STORM SYSTEM WILL BE GETTING CARVED OUT OVER THE MID SECTION OF THE NATION. A COLD FRONT WILL BE APPROACHING FROM THE WEST WHILE LOW PRESSURE STRENGTHENS ALONG THE BOUNDARY OVER THE WEST COAST OF FLORIDA. AS THIS WAVE MOVES UP ALONG THE SOUTHEAST COAST THE WINDS WILL BECOME QUITE STRONG AND A SMALL CRAFT ADVISORY IS EXPECTED. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 3 PM TUESDAY...DEPENDING ON THE EXACT TIMING OF THE FRONTAL PASSAGE EARLY FRIDAY...SMALL CRAFT ADVISORY CONDITIONS MAY STILL BE ONGOING FRIDAY MORNING...ESPECIALLY FROM CAPE FEAR NORTH. HOWEVER CONDITIONS WILL IMPROVE DURING THE MORNING HOURS AS WEAK HIGH PRESSURE BUILDS IN. WINDS WILL DIMINISH TO 15 KT BY MIDDAY FRIDAY AND SHIFT TO AN OFFSHORE TRAJECTORY. THE PRESSURE GRADIENT WILL CONTINUE TO WEAKEN WITH SPEEDS EXPECTED TO FALL TO 10 KT OR LESS SATURDAY-SUNDAY. BY SUNDAY...SOME VARIABILITY IN THE WIND DIRECTION CAN BE EXPECTED AS SPEEDS LOOK TO DROP BELOW 10 KT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...DCH/JDW SHORT TERM...MBB LONG TERM...CRM AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
130 AM EDT MON MAY 12 2014 .SYNOPSIS... HIGH PRESSURE OFFSHORE WILL MAINTAIN WELL ABOVE NORMAL TEMPERATURES THROUGH THE MIDDLE OF THE UPCOMING WEEK. A COLD FRONT WILL APPROACH THURSDAY BEFORE CROSSING OFFSHORE ON FRIDAY...BRINGING A GOOD CHANCE FOR SHOWERS AND THUNDERSTORMS. COOLER TEMPERATURES WILL DEVELOP IN THE WAKE OF THIS COLD FRONT INTO NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... AS OF 1045 PM SUNDAY...RIDGING ALOFT AND ITS AXIS NEARLY OVERHEAD...WILL AMPLIFY-SOME ACROSS THE BI-STATE REGION OVERNIGHT AND INTO THE SHORT TERM PERIOD. THIS WILL DEFLECT ANY S/W TROFS ALOFT TO THE WEST AND NORTH OF THE FA. AT THE SFC...MODEST HIGH PRESSURE CENTERED OFFSHORE AND EAST OF THE CAROLINAS...WILL RIDGE BACK ACROSS THE REGION...AND PREVAIL GOING INTO THE SHORT TERM PERIOD. FOR THE REMAINDER OF THIS EVENING AND OVERNIGHT...THE DIURNALLY INDUCED CONVECTION HAS DISSIPATED LEAVING A FEW OUTFLOW BOUNDARIES ACROSS PORTIONS OF THE FA GOING INTO DAYLIGHT MONDAY. WITH THE MAJORITY OF THE LEFTOVER CONVECTIVE CLOUDINESS DISSIPATING...A SFC BASED INVERSION SHOULD DEVELOP COURTESY OF THE HOURLY NAMBUFR SOUNDINGS. LOW LEVEL STRATUS BELOW 1K FEET WILL DEVELOP ACROSS THE FA VIA LATEST HRRR MODEL RUNS. MIN TEMPS HAVE BEEN MASSAGED UPWARDS ESPECIALLY WITH LOW LEVEL STRATUS OVERTAKING THE FA AND SFC DEWPOINTS REMAINING WELL INTO THE 60S ACROSS THE MAJORITY OF THE FA. PATCHY TO AREAS OF FOG WILL ALSO BE ADVERTISED ACROSS THE FA...FOR MAINLY THE HOURS BETWEEN MIDNIGHT TO JUST AFTER SUNRISE. COULD BE ONE OF THOSE NIGHTS WHERE LOW LEVEL STRATUS AND FOG DUEL WITH ONE ANOTHER IN SEEING WHO WILL PREVAIL OVER THE OTHER. PREVIOUS DISCUSSION............................................ AS OF 300 PM SUNDAY...ISOLATED TO WIDELY SCATTERED SHOWERS ARE BREAKING OUT ACROSS THE FORECAST AREA EARLY THIS AFTERNOON. SO FAR HAVE NOTED ONLY ONE BRIEF THUNDERSTORM OVER COASTAL GEORGETOWN COUNTY. WITH A MODERATELY UNSTABLE ATMOSPHERE AND MOIST LOW LEVELS EXPECT THIS ACTIVITY TO CONTINUE FOR THE REMAINDER OF THE AFTERNOON AND INTO THE EARLY EVENING. BOTH GFS AND NAM INDICATE COLUMN MOISTURE BECOMING MORE SHALLOW AFTER SUNSET AND WITH AN UPPER RIDGE BUILDING IN SEE LITTLE CHANCE FOR SIGNIFICANT OVERNIGHT PRECIPITATION. SO...AS THIS ACTIVITY SEEMS DIURNALLY DRIVEN WITH NO STRONG FORCING MECHANISM PRESENT...EXPECT CONVECTION TO FADE WITH THE SETTING SUN AND TO BE OVER WITH BY MIDNIGHT. HAVE CONTINUED RECENT TREND OF FORECASTING MINIMUM TEMPERATURES A FEW DEGREES ABOVE GUIDANCE. THIS METHOD HAS BEEN VERIFYING WELL AGAINST GUIDANCE RECENTLY AND GIVES US OVERNIGHT MINIMUMS IN THE MID 60S FOR MOST PLACES. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...SUMMERTIME PATTERN AMPLIFIES DURING THE BEGINNING OF THE WEEK THANKS TO A STRENGTHENING 5H RIDGE. THIS WILL DRIVE TEMPERATURES WELL INTO THE 80S TO AROUND 90 MONDAY AND TUESDAY AWAY FROM THE COAST...WITH LOW 80S ANTICIPATED AT THE BEACHES. THESE VERY WARM TEMPS...COMBINED WITH STILL COOL OCEAN TEMPS...AND A WEAK GRADIENT BOTH AT THE SURFACE AND ALOFT...SHOULD ALLOW DECENT INLAND PENETRATION OF THE SEA BREEZE BOTH DAYS. THIS WILL HAVE ONLY LIMITED IMPACT ON HIGHS THOUGH SINCE TEMPS WILL SOAR QUICKLY DURING LATE MORNING EARLY AFTN...THANKS TO LOWS ONLY FALLING INTO THE MID/UPR 60S...70 AT THE COAST. MORE QUESTIONABLE PORTION OF THE FORECAST INVOLVES CONVECTIVE POTENTIAL THROUGH EARLY WEEK. GUIDANCE IS STUBBORNLY DEPICTING SCATTERED SHOWERS/TSTMS BOTH MONDAY AND TUESDAY AFTNS...FOCUSED PRIMARILY ON THE SEA BREEZE. SPC HAS GENERAL RISK ACROSS THE AREA BOTH DAYS AS WELL. AM STRUGGLING TO FIND REASONS TO INCLUDE CONVECTION IN THE FORECAST...OTHER THAN DEWPOINTS WELL INTO THE 60S AND STEEP SURFACE-BASED LAPSE RATES. HOWEVER...PRETTY MUCH EVERYTHING ELSE POINTS TO THE NEXT TWO DAYS BEING DRY. 500MB RIDGE AXIS SITS NEARLY OVERHEAD...PROVIDING A SUBSIDENT LID WITH VERY WEAK MID-LEVEL LAPSE RATES. 700MB RIDGE REMAINS ANCHORED OVERHEAD AS WELL...FORCING ANY MOISTURE AROUND TO THE WEST OF THE AREA...WHICH IS ALSO ECHOED BY WEAK 850-700MB MOISTURE TRANSPORT VECTORS AND DRYING FORECAST SOUNDINGS. LCL`S ARE AT THE TOP OF WHATEVER RESIDUAL MOIST LAYER EXISTS MONDAY AND TUESDAY...SO UPDRAFTS SHOULD SUFFER FROM SIGNIFICANT DRY AIR ENTRAINMENT...FURTHER LIMITING CONVECTIVE POTENTIAL. STILL...INHERITED HAS SCHC MONDAY AND SURROUNDING WFO`S HAVE AT LEAST THAT...SO WILL KEEP SCHC MONDAY FOR ISOLATED SHOWERS...BUT DROP POP TO SILENT ON TUESDAY. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 300 PM SUNDAY...THE BIG WEATHER MAKER IN THE LONG TERM WILL BE AN EASTWARD-MOVING COLD FRONT THURSDAY...PUSHED ALONG BY A FULL LATITUDE UPPER TROUGH EXTENDING FROM HUDSON BAY TO THE GULF COAST. THE WESTERN EXTENSION OF THE BERMUDA HIGH WILL COVER THE AREA WEDNESDAY. RELATIVELY STABLE ONSHORE WINDS AND PLENTY OF DRY AIR ASSOCIATED WITH THE DEEP-LAYER RIDGING SHOULD KEEP THINGS MOSTLY SUNNY AND DRY WITH HIGHS IN THE UPPER 80S INLAND AND AROUND 80 ON THE BEACHES. PRESSURES WILL BEGIN TO FALL WEDNESDAY NIGHT AS THE AFOREMENTIONED FRONT CROSSES THE LOWER MISSISSIPPI VALLEY. INCREASING SOUTHERLY FLOW WILL BEGIN TO MOISTEN OUR AIRMASS...AND PRECIPITABLE WATER VALUES SHOULD CLIMB FROM AROUND 1 INCH WEDNESDAY TO 1.5 INCHES BY LATE WEDNESDAY NIGHT. INTEGRATED COLUMN MOISTURE PEAKS JUST AHEAD OF THE FRONT THURSDAY EVENING WITH PW VALUES NEAR 1.9 INCHES. 850 MB WINDS DO NOT BECOME PARTICULARLY STRONG...20-30 KT DEPENDING ON YOUR MODEL...AND KINEMATIC FIELDS ARE NOT OVERLY CONCERNING FOR A SEVERE WEATHER RISK. GIVEN MODEST FORECAST INSTABILITY (CAPE 1000-1500 J/KG) AND SUCH MOIST SOUNDINGS THE LARGEST CONCERN COULD BE LOCALLY HEAVY RAIN AND PERHAPS A WET DOWNBURST IN STRONGER CELLS. THE BULK OF THE LATEST OPERATIONAL MODEL RUNS SHOW THE COLD FRONT PUSHING ACROSS THE EASTERN CAROLINAS THURSDAY NIGHT...HOWEVER THE 12Z CANADIAN AS WELL AS ABOUT 25% OF THE 00Z & 06Z GFS ENSEMBLE MEMBERS ARE SLOWER MOVING THE BOUNDARY OFF THE COAST. I HAVE THEREFORE MAINTAINED A 30-40 POP INTO FRIDAY. DRY WEATHER SHOULD ALMOST CERTAINLY DEVELOP BY FRIDAY EVENING LASTING INTO SATURDAY AS HIGH PRESSURE BUILDS OVER THE CAROLINAS. THE MOST NOTABLE FEATURE ABOUT THIS INCOMING AIRMASS WILL BE HOW MILD TEMPERATURES WILL BE COMPARED TO WHAT WE HAVE EXPERIENCED THE PAST WEEK. WITH 850 MB TEMPS PROGGED +8C TO +10C BOTH FRIDAY AND SATURDAY...HIGHS SHOULD REMAIN IN THE UPPER 70S FOR MOST AREAS WITH LOWS IN THE 50S. BY NEXT SUNDAY BOTH THE GFS AND ECMWF SHOW THE TRAILING END OF A POTENT UPPER LEVEL DISTURBANCE MOVING ACROSS THE CAROLINAS. EVEN WITH NO LOW-LEVEL GULF OR ATLANTIC INFLOW...MODELS SHOW ENOUGH PACIFIC MOISTURE COMING ACROSS AT AND ABOVE 850 MB THAT A 30 POP FOR SHOWERS APPEARS WARRANTED. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... AS OF 06Z...EXPECT IFR CIGS/VSBYS ACROSS THE CWA TONIGHT AS NEARLY CALM CONDITIONS PROMOTE FOG AND STRATUS. WIDESPREAD STRATUS AND SOME FOG WAS ALREADY OCCURRING ACROSS THE COASTAL TAF SITES...PRODUCING IFR OR LOWER CONDITIONS. WE EXPECT THESE SAME CONDITIONS WILL OVERSPREAD KLBT AND KFLO THROUGH 08Z. CONDITIONS SHOULD IMPROVE TO VFR BY 13Z OR SO...WITH LIGHT AND VRB WINDS EARLY BECOMING SOUTH AOB 10 KT IN THE AFTERNOON. FCST SOUNDINGS SHOW A LOT OF DRY MID-LEVEL AIR DURING THE DAY...SO CONVECTION SHOULD BE ISOLATED AT BEST AS DIURNAL CU BUILDS WITH DAYTIME HEATING. EXTENDED OUTLOOK...EARLY MORNING MVFR/IFR FOG/STRATUS IS POSSIBLE THROUGH THURSDAY. OTHERWISE VFR CONDITIONS WILL PREVAIL THROUGH WEDNESDAY. SHOWERS/TSTMS EXPECTED THURSDAY THROUGH EARLY FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1045 PM SUNDAY...ORIENTATION OF THE SFC RIDGE AXIS EXTENDING ACROSS THE AREA WATERS FROM THE HIGHS CENTER OFFSHORE AND EAST OF THE CAROLINAS...WILL DETERMINE WIND DIRECTIONS. AT THIS POINT...MODELS INDICATE WINDS BECOMING SW-WSW NORTH OF LITTLE RIVER INLET...AND S TO SSW SOUTH OF THIS INLET. THIS TO OCCUR AFTER THE DEMISE OF THE SEA BREEZE CIRCULATION. THE LOOSE SYNOPTIC SFC PRESSURE GRADIENT WILL KEEP WIND SPEEDS AT OR BELOW 10 KT. SIGNIFICANT SEAS WILL RUN 2 TO OCCASIONALLY 3 FT...AND MAINLY BE COMPRISED OF WIND DRIVEN WAVES WITH PERIODS OF 5 TO 6 SECONDS. AT THIS POINT...THE 11 TO 13 SECOND PERIOD EASTERLY GROUND SWELL REMAINS NEGLIGIBLE FOR ANY INPUT INTO THE SIGNIFICANT SEAS. PREVIOUS DISCUSSION.......................... AS OF 300 PM SUNDAY...MANAGEABLE MARINE CONDITIONS EXPECTED. EXPECT A LIGHT SW WIND FLOW ACROSS THE WATERS THROUGH TONIGHT. SEAS GENERALLY 2-3 FEET...IN A MIX OF SSW WAVES 1-2 FEET EVERY 4-5 SEC AND SE WAVES 1-2 FT EVERY 7-8 SECONDS. ISOLATED TSTMS ARE POSSIBLE NEAR SHORE THIS AFTERNOON INTO THIS EVENING...AND THE MOTION WILL BE FROM SW TO NE. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...PRIMARILY UNIFORM WIND/WAVE CONDITIONS DURING THE SHORT TERM AS BERMUDA HIGH PRESSURE SITS OFFSHORE INTO MID-WEEK. RETURN FLOW AROUND THIS HIGH PRODUCES SW WINDS OF 10-15 KTS DURING THE DAY...AND 5-10 KTS AT NIGHT. THE EXCEPTION WILL BE IN THE NEAR-SHORE WATERS WHERE A SEA BREEZE WILL CAUSE WINDS TO GUST UP TO 20 KTS FOR A FEW HOURS EACH AFTN/EVE. THESE WINDS COMBINED WITH THE LONG FETCH AROUND THE HIGH PRESSURE WILL BUILD SEAS TO 2-3 FT THROUGH THE PERIOD...WITH A 5 SEC S/SW WIND WAVE AND A 7 SEC SE GROUND SWELL COMPRISING THE SPECTRUM. LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 300 PM SUNDAY...HIGH PRESSURE JUST OFFSHORE WEDNESDAY SHOULD PROVIDE GENTLE ONSHORE WINDS AND DRY WEATHER. MOISTURE WILL INCREASE THURSDAY AHEAD OF A COLD FRONT...EXPECTED TO MOVE OFF THE COAST FRIDAY MORNING. THIS FRONT SHOULD BE PRECEDED BY WAVES OF SHOWERS AND EMBEDDED THUNDERSTORMS...ESPECIALLY LATE THURSDAY AFTERNOON INTO THURSDAY NIGHT. ONCE THE FRONT MOVES FARTHER OFFSHORE FRIDAY... CLEARING CONDITIONS ARE EXPECTED ALONG WITH BREEZY NORTH TO NORTHWEST WINDS. AT THIS TIME IT APPEARS CONDITIONS SHOULD REMAIN BELOW ADVISORY THRESHOLDS...ALTHOUGH WINDS BOTH AHEAD OF AND BEHIND THE FRONT COULD APPROACH 20 KNOTS SOUTHEAST OF CAPE FEAR WHERE SEA SURFACE TEMPERATURES ARE CURRENTLY HIGHEST. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...DCH/REK SHORT TERM...JDW LONG TERM...TRA AVIATION...BJR/RJD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
329 PM CDT MON MAY 12 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 329 PM CDT MON MAY 12 2014 MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE WINDS ACROSS THE AREA THROUGH THE REMAINDER OF THE AFTERNOON...PRECIPITATION ENDING IN THE EAST THIS EVENING AND OVERNIGHT TEMPERATURES. CURRENTLY...SURFACE LOW PRESSURE OVER SOUTHEAST MINNESOTA WITH AN INVERTED TROUGH NORTH THROUGH NORTHERN MINNESOTA. THE DEFORMATION ZONE ASSOCIATED WITH THIS LOW PRESSURE SYSTEM WILL CONTINUE TO TRACK EAST THIS EVENING AND RAIN SHOWERS WILL END OVER THE JAMES RIVER VALLEY THIS EVENING. LATEST RAP SOUNDINGS INDICATE THAT AREAS ALONG AND WEST OF HIGHWAY 83 WILL SEE DIMINISHING WINDS THIS EVENING. IT MAY BE BREEZY THROUGH AROUND 9 PM BUT WINDS SHOULD REMAIN BELOW ADVISORY LEVELS. WINDS COULD HOLD ON OVER EASTERN PORTIONS OF CENTRAL NORTH DAKOTA WITH KJMS AND CARRINGTON 19 UTC BUFR SOUNDINGS INDICATING THE BOUNDARY LAYER REMAINING LIFTED WITH 40 KNOT WINDS AVAILABLE TO WORK DOWN. GRADIENT WINDS WILL BE STRONGEST HERE ALSO...CLOSER TO THE SURFACE LOW. WILL KEEP THE ADVISORY GOING AND EVENING SHIFT WILL NEED TO LOOK INTO POSSIBLY EXTENDING EASTERN PORTIONS OF THE ADVISORY. CONVECTIVE CUMULUS FLATTENING OUT SHOULD SLOWLY DISSIPATE THIS EVENING. THUS MOSTLY CLEAR SKIES ARE EXPECTED BY MORNING. WILL SEE LOWS IN THE LOW TO MID 30S MOST AREAS. WINDS SHOULD REMAIN AT 5 TO 10 MPH OVERNIGHT...KEEPING TEMPERATURES FROM FALLING INTO THE 20S. MID 30S ARE EXPECTED OVER EASTERN PORTIONS OF CENTRAL NORTH DAKOTA WHERE WINDS AND CLOUDS HANG ON LONGER TONIGHT. TUESDAY WILL BE MUCH NICER THAN TODAY OVER THE JAMES RIVER VALLEY...WITH NO RAIN...LESS WIND AND MORE SUN. ELSEWHERE...TUESDAY IS EXPECTED TO SIMILAR TO TODAY...BUT WITH A LITTLE LESS CLOUDS AND WINDS AND A LITTLE MORE SUNSHINE. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 329 PM CDT MON MAY 12 2014 TROUGH MOVES EAST WEDNESDAY WITH NORTHWEST FLOW ALOFT DEVELOPING AND PERSISTING THROUGH THE FIRST HALF OF NEXT WEEKEND. EMBEDDED WAVE IS DEPICTED TO MOVE THROUGH SOMETIME THURSDAY NIGHT OR FRIDAY BRINGING A CHANCE FOR SHOWERS TO THE LOCAL AREA. OTHERWISE THE REST OF THE WORK WEEK APPEARS MAINLY DRY. 12Z GFS/ECMWF SHOW A SHORT WAVE RIDGE SATURDAY NIGHT FOLLOWED BY A MORE ACTIVE FLOW SUNDAY INTO MONDAY AHEAD AND ALONG A DEVELOPING TROUGH ORIGINATING OVER THE PACIFIC NORTHWEST AND PROGRESSING EASTWARD. MILDER TEMPERATURES OVER THE WEEKEND AS WELL...HELPING TO INCREASE THE POTENTIAL FOR THUNDERSTORMS SUNDAY-MONDAY. UNCERTAINTY STILL HIGH SO WILL LEAVE OUT OF THE FORECAST AT THIS TIME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 329 PM CDT MON MAY 12 2014 MVFR CEILINGS WILL CONTINUE THROUGH THE AFTERNOON AT KJMS...WITH CEILINGS EXPECTED TO LIFT ABOVE MVFR MONDAY EVENING. ELSEWHERE VFR CEILINGS ARE EXPECTED THROUGH THE PERIOD. LOW VFR CEILINGS WILL CONTINUE TO LIFT AND DISSIPATE THIS EVENING...BECOMING MOSTLY CLEAR OVERNIGHT. STRONG NORTH WINDS THROUGH THE AFTERNOON WILL DIMINISH TONIGHT AND PICK UP AGAIN ON TUESDAY BUT ARE NOT EXPECTED TO BE AS STRONG...WITH MORE OF A NORTHWEST DIRECTION. WE MAY SEE A PERIOD OF LOW VFR CEILINGS IN CUMULUS EARLY TUESDAY AFTERNOON...JUST BEYOND THE TAF PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR NDZ002>005-010>013-018>023-025-031>037-040>048-050-051. && $$ SHORT TERM...TWH LONG TERM...NH AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1005 AM CDT MON MAY 12 2014 .UPDATE... ISSUED AT 1005 AM CDT MON MAY 12 2014 MADE SOME SLIGHT ADJUSTMENTS TO BUMP UP SKY COVER A LITTLE IN THE WEST THROUGH THIS MORNING. ALSO ADJUSTED PRECIPITATION BASED ON LATEST RADAR AND 12Z HRRR GUIDANCE. OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST. UPDATE ISSUED AT 639 AM CDT MON MAY 12 2014 NO MAJOR UPDATES ARE REQUIRED TO THE ONGOING FORECAST. THE CURRENT WIND ADVISORY STILL LOOKS GOOD FOR TODAY. ONLY MODIFIED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 353 AM CDT MON MAY 12 2014 MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE PRECIPITATION CHANCES OVER THE EASTERN THIRD OF THE FORECAST AREA TODAY...AND WINDS TODAY. CURRENTLY...FRONTAL BOUNDARY EXTENDED FROM LAKE WINNIPEG SOUTHEAST ACROSS MINNESOTA SOUTH INTO IOWA AND SOUTHWESTWARD TO KANSAS AND OKLAHOMA. HIGH PRESSURE EXTENDED ALONG THE FRONT RANGE OF THE ROCKIES. WIDESPREAD LOWER CLOUD COVER ACROSS EASTERN PORTIONS OF CENTRAL NORTH DAKOTA...WITH HIGHER CLOUDS TO THE WEST. AT UPPER LEVELS...A LARGE LONGWAVE TROUGH EXTENDED FROM NORTH CENTRAL CANADA SOUTHWARD ACROSS THE DAKOTAS TO THE 4-CORNERS AREA. MODELS ARE IN GOOD AGREEMENT KEEPING AN AREA OF SHOWERS MAINLY FROM SOUTH CENTRAL NORTH DAKOTA EAST OF THE MISSOURI RIVER TO THE JAMES AND DEVILS LAKE BASINS...MAINLY SOUTH AND EAST OF A LINE FROM LINTON TO HARVEY AND CARRINGTON. THERE MAY BE A RAIN/SNOW MIX ON THE FAR WESTERN EDGE OF THE PRECIPITATION - BUT WOULD BE VERY LIGHT. TEMPERATURES WEST OF THE PRECIPITATION AREA WERE IN THE LOWER 30S...WITH UPPER 30S TO 40 WHERE SCATTERED SHOWERS WERE OCCURRING. THE UPPER LEVEL TROUGH IS PROGGED TO MOVE EASTWARD SLOWLY TODAY - REACHING MINNESOTA BY DAYBREAK TUESDAY MORNING. MEANWHILE THE SURFACE FRONTAL BOUNDARY EVOLVES INTO A CLOSED LOW OVER WISCONSIN BY THIS EVENING...LIFTING NORTHWARD ACROSS LAKE SUPERIOR INTO WESTERN ONTARIO BY DAYBREAK TUESDAY. THIS WILL KEEP THE EASTERN THIRD OF NORTH DAKOTA WITHIN THE WESTERN BOUNDARY OF THE EXPECTED AREA OF SHOWERS TODAY THROUGH THIS EVENING...WITH CHANCES OF PRECIPITATION DECREASING DURING THE OVERNIGHT HOURS MONDAY NIGHT. THE WEST WILL CONTINUE TO DRY OUT AS HIGH PRESSURE CONTINUES TO MOVE SOUTH/SOUTHEAST INTO THE WESTERN PLAINS. THE PRESSURE GRADIENT BETWEEN THE STRONG LOW AND HIGH PRESSURE SYSTEMS WILL SET UP FOR WINDY CONDITIONS TODAY - AND THE CURRENT WIND ADVISORY FOR ALL BUT THE FAR NORTHWEST SEEMS REASONABLE AND WILL NOT CHANGE AREAL COVERAGE OR TIMING OF THE WIND ADVISORY. BUFR SOUNDINGS STILL INDICATE THAT BY AROUND 9-10 AM SHOULD SEE MIXING OF BOUNDARY LAYER WINDS...RESULTING IN AN AREA OF SUSTAINED 30 MPH WINDS WITH GUSTS TO 40 MPH AT TIMES. USED A CONSENSUS BLEND OF MODELS FOR WIND SPEEDS WHICH KEEPS THE ADVISORY CRITERIA ACROSS MOST OF THE CWA. WINDS SHOULD DECREASE FROM WEST TO EAST TONIGHT TO AROUND 10 TO 15 MPH. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 353 AM CDT MON MAY 12 2014 THE 00Z GFS/GEM/ECMWF PROG AN UPPER LOW/WAVE TO CONTINUE TO MEANDER EAST INTO NORTHEASTERN MANITOBA/NORTHWESTERN ONTARIO TUESDAY. MOST OF THE MOISTURE/PRECIPITATION CHANCES OVER WESTERN AND CENTRAL NORTH DAKOTA WILL CONTINUE TO SHIFT EAST IN RESPONSE. BY WEDNESDAY AND THURSDAY...SYNOPTIC SUBSIDENCE IS PROGGED TO OVERSPREAD THE STATE LEADING TO DRY CONDITIONS. SURFACE HIGH PRESSURE IS PROGGED TO SETTLE ACROSS THE STATE THURSDAY MORNING. THIS COULD LEAD TO LOWS IN THE LOWER 30S/UPPER 20S THURSDAY MORNING...ESPECIALLY IN LOW-LYING AREAS. THE MEDIUM RANGE MODELS HAVE BACKED OFF ON A WEAK WAVE PREVIOUSLY FORECAST TO TRAVERSE NORTH DAKOTA FRIDAY/FRIDAY NIGHT. FOR THE SAKE OF CONSISTENCY...CONTINUED TO INDICATE SLIGHT CHANCE POPS FRIDAY/FRIDAY NIGHT. IF THE LATEST TRENDS CONTINUE...FUTURE SHIFTS MAY NEED TO REMOVE POPS FROM THE FRIDAY FORECAST ALTOGETHER. AN UPPER LEVEL RIDGE IS THEN FORECAST TO TRANSLATE EAST INTO THE GREAT PLAINS BY SATURDAY GENERATING DRY CONDITIONS AND NEAR NORMAL TEMPERATURES. THE MEDIUM RANGE MODELS ARE SURPRISINGLY CONSISTENT PROGGING A PACIFIC NORTHWEST LONGWAVE TROUGH TO ENTER THE NORTHERN ROCKIES SUNDAY. THE POSITION OF THIS FEATURE WARRANTS A CHANCE OF SHOWERS MENTION FOR NOW...ESPECIALLY ACROSS WESTERN NORTH DAKOTA. COULD BEGIN TO SEE SOME THUNDER CHANCES SNEAK IN OVER WESTERN NORTH DAKOTA GIVEN THE FORECAST UPPER PATTERN SUNDAY. HOWEVER...WILL KEEP THUNDER OUT OF THE FORECAST FOR NOW DUE TO THE UNCERTAINTIES ASSOCIATED WITH A DAY 7 FORECAST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 1005 AM CDT MON MAY 12 2014 SCATTERED TO NUMEROUS SHOWERS EXPECTED AT KJMS WITH MVFR CEILINGS THE PREVAILING CONDITIONS. VFR CLOUDS WILL BE IN PLACE AT THE REMAINING TAF SITES. STRONG NORTH WINDS EXPECTED ACROSS MOST OF WESTERN AND CENTRAL NORTH DAKOTA TODAY. SUSTAINED WINDS AROUND 25 KTS AT KDID...KBIS...KMOT AND KJMS WITH GUSTS UP TO AROUND 35 KTS. WINDS WILL BE NOT AS STRONG AT KISN WITH SUSTAINED 15 T0 20 KNOTS AND GUSTS TO 30 KTS. WINDS TO SUBSIDE BY AROUND 00Z WEST TO 03Z EAST. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR NDZ002>005-010>013-018>023-025-031>037-040>048-050-051. && $$ UPDATE...TWH SHORT TERM...JV LONG TERM...TM AVIATION...TWH
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1026 PM EDT TUE MAY 13 2014 .SYNOPSIS... HIGH PRESSURE WILL PERSIST THROUGH MID WEEK...BEFORE A COLD FRONT CROSSES FROM THE WEST ON THURSDAY. A COOLER AND DRIER AIR MASS WILL SETTLE ACROSS THE REGION FRIDAY AND SLOWLY MODIFY WARMER THROUGH EARLY NEXT WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 1025 PM...GOING FCST ON TRACK. ONLY A COUPLE OF SHRA LEFT TO DISSIPATE BEFORE MIDNIGHT. LOW TEMPS LOOK ON TRACK AS WELL. UPDATES FOR CURRENT CONDITIONS. AS OF 740 PM...COVERAGE OF CONVECTION BEGINNING TO DIMINISH EARLY THIS EVENING. A FEW CELLS COULD LINGER UNTIL AFTER SUNSET...BUT ALL SHOULD BE GONE BY MIDNIGHT. DO NOT EXPECT ANY CONVECTION RETURNING UNTIL AFTER DAYBREAK WED. MADE SOME MINOR ADJUSTMENTS DOWNWARD TO LOW TEMPS OVERNIGHT IN LINE WITH LATEST GUIDANCE. OTHERWISE... UPDATES WERE MAINLY LIMITED TO CURRENT CONDITIONS. AS OF 425 PM...SCT CONVECTION REMAINS LIMITED TO THE TN BORDER AREA WITH ISOLATED CONVECTION SOUTH TO THE NC/SC BORDER. THINK THIS TREND WILL CONTINUE INTO THE EVENING BEFORE DISSIPATING OVERNIGHT. HAVE UPDATED FOR THESE TRENDS AND FOR OTHER CURRENT CONDITIONS. AS OF 200 PM EDT TUESDAY...THE LATEST RUNS OF THE HRRR AND OUR LOCAL WORKSTATION WRF DRIFT MOST OF THE SHOWER AND TSTM ACTIVITY OVER THE NC MTNS INTO ERN TN OVER THE NEXT FEW HOURS. ISOLATED SHOWERS AND A FEW TSTMS ARE ALSO EXPECTED FOR A WHILE LONGER OVER THE NC FOOTHILLS WHERE THERE IS LIGHT UPSLOPE FLOW AND SIGNS OF TOWERING CU ON THE VSBL SATELLITE IMAGERY. ELSEWHERE THE LATE AFTN AND EVENING HOURS SHOULD BE LARGELY DRY. OVERNIGHT...AREAS OF VALLEY FOG ARE AGAIN EXPECTED TO DEVELOP OVER THE SOUTHWEST AND CENTRAL NC MTNS. LATE IN THE DAY ON WEDNESDAY THERE ARE SIGNS THAT SHOWER AND THUNDERSTORM ACTIVITY WILL BEGIN TO PICK UP OVER THE REGION... ESPECIALLY OVER THE MOUNTAINS AND THE FOOTHILLS. HOWEVER...THIS IS NOT EXPECTED TO HAPPEN UNTIL THE EARLY EVENING HOURS. UPSLOPE FLOW SHOULD RESULT IN A LITTLE MORE CLOUD COVER ALONG THE SOUTHERN ESCARPMENT OF THE APPALACHIANS AND MAX TEMPS HAVE BEEN ADJUSTED DOWN A FEW DEGREES IN THOSE AREAS. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... AS OF MIDDAY TUESDAY...WRN ATLANTIC HIGH PRESSURE WILL BEGIN TO DISLODGE WED NIGHT AS DEEP LONGWAVE TROUGH DIGS INTO THE MISSISSIPPI VALLEY. UNDER THE INFLUENCE OF A SHORTWAVE EMBEDDED IN THE TROUGH...A SFC LOW WILL DEVELOP ALONG THE STALLED COLD FRONT EXTENDING FROM THE WRN GULF NEWD INTO THE ERN GREAT LAKES. THE LOW WILL LIFT THRU THE OHIO VALLEY THURSDAY AND THE COLD FRONT WILL PUSH EWD INTO OUR AREA AT THIS TIME. STRONG MOISTURE ADVECTION THROUGH A DEEP LAYER AHEAD OF THE FRONT WILL BRING A HEAVY RAIN THREAT TO THE CWFA AS EARLY AS THU MRNG. A SECONDARY THREAT MAY BE POSED BY SEVERE WX BUT THE HEAVY RAIN IS OF GREATER CONCERN AT THIS TIME. NEARLY DUE SOUTHERLY LLJ WILL QUICKLY GET UNDERWAY WED EVENING AS THE GRADIENT TIGHTENS AHEAD OF THE DEVELOPING FRONTAL WAVE. GFS AND NAM BOTH DEPICT PWAT VALUES SURGING ABOVE 1.5 INCHES BY 06Z THU. ENHANCEMENT ALONG THE BLUE RIDGE IS TO BE EXPECTED AND IS REFLECTED IN QPF GUIDANCE FROM THE MAJOR MODELS. A FAIR NUMBER OF SREF AND GEFS MEMBERS PRODUCE QPF OF OVER 1 INCH IN 6 HOURS WHICH IS IN LINE WITH THE UPPER END OF THE OPNL GUIDANCE RANGE AND WPC. THE EVENT LOOKS TO BE TWO-PRONGED...AFFECTING THE BLUE RIDGE AREAS EARLIER ON AS THE LLJ INTERCEPTS THE RIDGE...AND LATER AS THE BEST MOISTURE ADVECTION OCCURS OVER THE NW PIEDMONT AND CHARLOTTE METRO. THE LATTER BECOMES AN ISSUE LATE THU AFTN OR EVENING. THE GFS AND NAM BOTH PRODUCE A FRONTAL WAVE AT THIS TIME MOVING NWD FROM THE GA COAST. THIS ENHANCES MOISTURE TRANSPORT FROM THE ATLANTIC AND ALSO SLOWS THE EWD MOVEMENT OF THE FRONT. A FLOOD WATCH IS LIKELY TO BE NEEDED ONCE BOTH WAVES OF HEAVIER PRECIP COME WITHIN THE USUAL WINDOW FOR ISSUANCE. SOUNDINGS ARE DEEPLY SATURATED AND LAPSE RATES ACCORDINGLY MARGINAL DURING THE BULK OF THE EVENT. OVERALL INSTABILITY IS LOW BUT SHEAR BECOMES QUITE STRONG LATE WED NIGHT. EXCEPT IN THE SW MTNS WHERE THE FRONT PUSHES IN EARLY ON...OVERLAP OF THESE PARAMETERS CONTINUES THRU THE DAY THU ACRS THE AREA SO CONVECTIVE CELLS WILL NEED TO BE MONITORED CLOSELY. THAT SECONDARY FRONTAL WAVE WILL MOVE NORTH OF THE AREA AS THE UPPER TROUGH SWINGS IN FRIDAY...GRADUALLY BRINGING THE PIEDMONT PRECIP TO AN END DURING THE MORNING. AFTER A MORE SETTLED PERIOD...SOME DIURNAL CONVECTION MAY KICK OFF LATE IN THE DAY OVER THE HIGH TERRAIN...AND GARDEN VARIETY SHOWERS COULD RETURN MAINLY IN THE NRN MTNS. MAX TEMPS FOLLOWING THE FROPA WILL BE NOTICEABLY COOLER...A FEW DEGREES BELOW CLIMO. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AT 200 PM EDT TUESDAY...A LARGE ULVL LOW WILL PERSIST ACROSS THE ERN CONUS TO BEGIN THE EXT RANGE AND SLOWLY LIFT AND PUSH EAST THROUGH THE PERIOD. THERE IS GOOD AGREEMENT IN THE OP MODELS WITH THIS SCENARIO WITH LITTLE OUTLYING DEVIATIONS ON THE SYNOPTIC SCALE. SOME SIGFNT DIFFERENCES SHOW UP IN AVAILABLE LLVL MOISTURE SAT/SUN AND THIS IS ALREADY ACCOUNTED FOR WELL WITH THE LOW END CHANCE POPS. THE ATMOS WILL BE SLOW TO MODIFY AT THE SFC WITH A FAIRLY STRONG THETA/E TROF ACCOMPANYING A CP HIPRES CENTER ACROSS THE GLAKES. THIS WILL HOLD TD/S WELL BELOW NORMAL OVER THE WEEKEND AND ALLOW NON/MTN LCL/S TO AROUND 8 KFT. THERE WILL BE SEVERAL UPPER ENERGY POCKETS CROSSING THROUGH THE PERIOD...WITH SAT INTO MID DAY SUN HAVING THE BEST CHANCE FOR A FORCED PRECIP ENHANCEMENT. STILL DON/T SEE ENOUGH DEEP CONVECTIVE POTENTIAL TO INCLUDE TSTMS IN THE FCST AS LFC/S REMAIN TOO COOL AND A MLVL WARM LAYER PERSISTS. WILL MAINTAIN THE SLIGHT CHANCE POPS EARLY SAT AND INCREASE TO LOW END CHANCES SAT NIGHT AND SUN ACROSS THE MTNS. DEEPER SUBSIDENCE BUILDS IN SUN NIGHT AS THE UPPER LOW SHIFTS EAST AND THE CHANCES FOR PRECIP WILL ACCORDINGLY GO TO NON/MENTIONABLE MON AND TUE WITH LOWERING COLUMN MOISTURE. OVERALL...IT LOOKS LIKE A VERY PLEASANT PERIOD WITH MAX TEMPS A FEW DEGREES BELOW NORMAL...PERHAPS A DEGREE OR TWO COOLER ON SUN WITH INCREASING MLVL CLOUDINESS. THEN A GENERAL WARM UP TO NORMAL AND ABOVE MON/TUE WITH TD/S HELD RELATIVELY LOW. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...FEW CU WILL DISSIPATE THIS EVENING LEAVING ON CIRRUS THRU DAYBREAK. SSW WINDS BECOME LIGHT SLY THIS EVENING. SWLY WINDS PICK UP AGAIN BY LATE MORNING WITH FEW CU DEVELOPING. STRONGER SLY WINDS EXPECTED FOR THE AFTERNOON WITH CU LIFTING AND BECOMING SCT. CANNOT RULE OUT AN ISOLATED CONVECTIVE CELL DURING THE AFTERNOON...BUT CHC TOO LOW TO INCLUDE IN THE TAF ATTM. ELSEHWERE...SCT TO ISOLATED CONVECTION WILL DISSIPATE THIS EVENING WITH MAYBE SOME LINGERING CONVECTIVE DEBRIS AT KAVL. ELSEWHERE DISSIPATING CU WILL LEAVE ONLY CIRRUS. S TO SW WIND WILL BECOME LIGHT OVERNIGHT. MTN VALLEY FOG SHOULD DEVELOP ONCE AGAIN...BUT WILL MOST LIKELY NOT DEVELOP AT KAVL AS BOUNDARY LAYER DEW POINTS ACTUALLY FALL LITTLE OVERNIGHT. FEW CU DEVELOP BY LATE MORNING WITH INCREASING S TO SW WINDS. WINDS INCREASE IN SPEED FOR THE AFTERNOON. AGAIN...BEST CHC FOR CONVECTION WILL BE OVER THE MTNS...SO PROB30 INCLUDED AT KAVL ONLY FOR THE AFTERNOON. OUTLOOK...ON THURSDAY A SLOW MOVING COLD FRONT WILL YIELD A BETTER CHANCE OF RESTRICTIONS IN PROLONGED PRECIPITATION AND THUNDERSTORMS. EXPECT VFR AGAIN FRIDAY AND SATURDAY. CONFIDENCE TABLE... 02-08Z 08-14Z 14-20Z 20-02Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 98% 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 98% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 98% 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...SBK NEAR TERM...MCAVOY/RWH SHORT TERM...WIMBERLEY LONG TERM...SBK AVIATION...RWH
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
741 PM EDT TUE MAY 13 2014 .SYNOPSIS... HIGH PRESSURE WILL PERSIST THROUGH MID WEEK...BEFORE A COLD FRONT CROSSES FROM THE WEST ON THURSDAY. A COOLER AND DRIER AIR MASS WILL SETTLE ACROSS THE REGION FRIDAY AND SLOWLY MODIFY WARMER THROUGH EARLY NEXT WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 740 PM...COVERAGE OF CONVECTION BEGINNING TO DIMINISH EARLY THIS EVENING. A FEW CELLS COULD LINGER UNTIL AFTER SUNSET...BUT ALL SHOULD BE GONE BY MIDNIGHT. DO NOT EXPECT ANY CONVECTION RETURNING UNTIL AFTER DAYBREAK WED. MADE SOME MINOR ADJUSTMENTS DOWNWARD TO LOW TEMPS OVERNIGHT IN LINE WITH LATEST GUIDANCE. OTHERWISE... UPDATES WERE MAINLY LIMITED TO CURRENT CONDITIONS. AS OF 425 PM...SCT CONVECTION REMAINS LIMITED TO THE TN BORDER AREA WITH ISOLATED CONVECTION SOUTH TO THE NC/SC BORDER. THINK THIS TREND WILL CONTINUE INTO THE EVENING BEFORE DISSIPATING OVERNIGHT. HAVE UPDATED FOR THESE TRENDS AND FOR OTHER CURRENT CONDITIONS. AS OF 200 PM EDT TUESDAY...THE LATEST RUNS OF THE HRRR AND OUR LOCAL WORKSTATION WRF DRIFT MOST OF THE SHOWER AND TSTM ACTIVITY OVER THE NC MTNS INTO ERN TN OVER THE NEXT FEW HOURS. ISOLATED SHOWERS AND A FEW TSTMS ARE ALSO EXPECTED FOR A WHILE LONGER OVER THE NC FOOTHILLS WHERE THERE IS LIGHT UPSLOPE FLOW AND SIGNS OF TOWERING CU ON THE VSBL SATELLITE IMAGERY. ELSEWHERE THE LATE AFTN AND EVENING HOURS SHOULD BE LARGELY DRY. OVERNIGHT...AREAS OF VALLEY FOG ARE AGAIN EXPECTED TO DEVELOP OVER THE SOUTHWEST AND CENTRAL NC MTNS. LATE IN THE DAY ON WEDNESDAY THERE ARE SIGNS THAT SHOWER AND THUNDERSTORM ACTIVITY WILL BEGIN TO PICK UP OVER THE REGION... ESPECIALLY OVER THE MOUNTAINS AND THE FOOTHILLS. HOWEVER...THIS IS NOT EXPECTED TO HAPPEN UNTIL THE EARLY EVENING HOURS. UPSLOPE FLOW SHOULD RESULT IN A LITTLE MORE CLOUD COVER ALONG THE SOUTHERN ESCARPMENT OF THE APPALACHIANS AND MAX TEMPS HAVE BEEN ADJUSTED DOWN A FEW DEGREES IN THOSE AREAS. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... AS OF MIDDAY TUESDAY...WRN ATLANTIC HIGH PRESSURE WILL BEGIN TO DISLODGE WED NIGHT AS DEEP LONGWAVE TROUGH DIGS INTO THE MISSISSIPPI VALLEY. UNDER THE INFLUENCE OF A SHORTWAVE EMBEDDED IN THE TROUGH...A SFC LOW WILL DEVELOP ALONG THE STALLED COLD FRONT EXTENDING FROM THE WRN GULF NEWD INTO THE ERN GREAT LAKES. THE LOW WILL LIFT THRU THE OHIO VALLEY THURSDAY AND THE COLD FRONT WILL PUSH EWD INTO OUR AREA AT THIS TIME. STRONG MOISTURE ADVECTION THROUGH A DEEP LAYER AHEAD OF THE FRONT WILL BRING A HEAVY RAIN THREAT TO THE CWFA AS EARLY AS THU MRNG. A SECONDARY THREAT MAY BE POSED BY SEVERE WX BUT THE HEAVY RAIN IS OF GREATER CONCERN AT THIS TIME. NEARLY DUE SOUTHERLY LLJ WILL QUICKLY GET UNDERWAY WED EVENING AS THE GRADIENT TIGHTENS AHEAD OF THE DEVELOPING FRONTAL WAVE. GFS AND NAM BOTH DEPICT PWAT VALUES SURGING ABOVE 1.5 INCHES BY 06Z THU. ENHANCEMENT ALONG THE BLUE RIDGE IS TO BE EXPECTED AND IS REFLECTED IN QPF GUIDANCE FROM THE MAJOR MODELS. A FAIR NUMBER OF SREF AND GEFS MEMBERS PRODUCE QPF OF OVER 1 INCH IN 6 HOURS WHICH IS IN LINE WITH THE UPPER END OF THE OPNL GUIDANCE RANGE AND WPC. THE EVENT LOOKS TO BE TWO-PRONGED...AFFECTING THE BLUE RIDGE AREAS EARLIER ON AS THE LLJ INTERCEPTS THE RIDGE...AND LATER AS THE BEST MOISTURE ADVECTION OCCURS OVER THE NW PIEDMONT AND CHARLOTTE METRO. THE LATTER BECOMES AN ISSUE LATE THU AFTN OR EVENING. THE GFS AND NAM BOTH PRODUCE A FRONTAL WAVE AT THIS TIME MOVING NWD FROM THE GA COAST. THIS ENHANCES MOISTURE TRANSPORT FROM THE ATLANTIC AND ALSO SLOWS THE EWD MOVEMENT OF THE FRONT. A FLOOD WATCH IS LIKELY TO BE NEEDED ONCE BOTH WAVES OF HEAVIER PRECIP COME WITHIN THE USUAL WINDOW FOR ISSUANCE. SOUNDINGS ARE DEEPLY SATURATED AND LAPSE RATES ACCORDINGLY MARGINAL DURING THE BULK OF THE EVENT. OVERALL INSTABILITY IS LOW BUT SHEAR BECOMES QUITE STRONG LATE WED NIGHT. EXCEPT IN THE SW MTNS WHERE THE FRONT PUSHES IN EARLY ON...OVERLAP OF THESE PARAMETERS CONTINUES THRU THE DAY THU ACRS THE AREA SO CONVECTIVE CELLS WILL NEED TO BE MONITORED CLOSELY. THAT SECONDARY FRONTAL WAVE WILL MOVE NORTH OF THE AREA AS THE UPPER TROUGH SWINGS IN FRIDAY...GRADUALLY BRINGING THE PIEDMONT PRECIP TO AN END DURING THE MORNING. AFTER A MORE SETTLED PERIOD...SOME DIURNAL CONVECTION MAY KICK OFF LATE IN THE DAY OVER THE HIGH TERRAIN...AND GARDEN VARIETY SHOWERS COULD RETURN MAINLY IN THE NRN MTNS. MAX TEMPS FOLLOWING THE FROPA WILL BE NOTICEABLY COOLER...A FEW DEGREES BELOW CLIMO. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AT 200 PM EDT TUESDAY...A LARGE ULVL LOW WILL PERSIST ACROSS THE ERN CONUS TO BEGIN THE EXT RANGE AND SLOWLY LIFT AND PUSH EAST THROUGH THE PERIOD. THERE IS GOOD AGREEMENT IN THE OP MODELS WITH THIS SCENARIO WITH LITTLE OUTLYING DEVIATIONS ON THE SYNOPTIC SCALE. SOME SIGFNT DIFFERENCES SHOW UP IN AVAILABLE LLVL MOISTURE SAT/SUN AND THIS IS ALREADY ACCOUNTED FOR WELL WITH THE LOW END CHANCE POPS. THE ATMOS WILL BE SLOW TO MODIFY AT THE SFC WITH A FAIRLY STRONG THETA/E TROF ACCOMPANYING A CP HIPRES CENTER ACROSS THE GLAKES. THIS WILL HOLD TD/S WELL BELOW NORMAL OVER THE WEEKEND AND ALLOW NON/MTN LCL/S TO AROUND 8 KFT. THERE WILL BE SEVERAL UPPER ENERGY POCKETS CROSSING THROUGH THE PERIOD...WITH SAT INTO MID DAY SUN HAVING THE BEST CHANCE FOR A FORCED PRECIP ENHANCEMENT. STILL DON/T SEE ENOUGH DEEP CONVECTIVE POTENTIAL TO INCLUDE TSTMS IN THE FCST AS LFC/S REMAIN TOO COOL AND A MLVL WARM LAYER PERSISTS. WILL MAINTAIN THE SLIGHT CHANCE POPS EARLY SAT AND INCREASE TO LOW END CHANCES SAT NIGHT AND SUN ACROSS THE MTNS. DEEPER SUBSIDENCE BUILDS IN SUN NIGHT AS THE UPPER LOW SHIFTS EAST AND THE CHANCES FOR PRECIP WILL ACCORDINGLY GO TO NON/MENTIONABLE MON AND TUE WITH LOWERING COLUMN MOISTURE. OVERALL...IT LOOKS LIKE A VERY PLEASANT PERIOD WITH MAX TEMPS A FEW DEGREES BELOW NORMAL...PERHAPS A DEGREE OR TWO COOLER ON SUN WITH INCREASING MLVL CLOUDINESS. THEN A GENERAL WARM UP TO NORMAL AND ABOVE MON/TUE WITH TD/S HELD RELATIVELY LOW. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...FEW CU WILL DISSIPATE THIS EVENING LEAVING ON CIRRUS THRU DAYBREAK. SSW WINDS BECOME LIGHT SLY THIS EVENING. SWLY WINDS PICK UP AGAIN BY LATE MORNING WITH FEW CU DEVELOPING. STRONGER SLY WINDS EXPECTED FOR THE AFTERNOON WITH CU LIFTING AND BECOMING SCT. CANNOT RULE OUT AN ISOLATED CONVECTIVE CELL DURING THE AFTERNOON...BUT CHC TOO LOW TO INCLUDE IN THE TAF ATTM. ELSEHWERE...SCT TO ISOLATED CONVECTION WILL DISSIPATE THIS EVENING WITH MAYBE SOME LINGERING CONVECTIVE DEBRIS AT KAVL. ELSEWHERE DISSIPATING CU WILL LEAVE ONLY CIRRUS. S TO SW WIND WILL BECOME LIGHT OVERNIGHT. MTN VALLEY FOG SHOULD DEVELOP ONCE AGAIN...BUT WILL MOST LIKELY NOT DEVELOP AT KAVL AS BOUNDARY LAYER DEW POINTS ACTUALLY FALL LITTLE OVERNIGHT. FEW CU DEVELOP BY LATE MORNING WITH INCREASING S TO SW WINDS. WINDS INCREASE IN SPEED FOR THE AFTERNOON. AGAIN...BEST CHC FOR CONVECTION WILL BE OVER THE MTNS...SO PROB30 INCLUDED AT KAVL ONLY FOR THE AFTERNOON. OUTLOOK...ON THURSDAY A SLOW MOVING COLD FRONT WILL YIELD A BETTER CHANCE OF RESTRICTIONS IN PROLONGED PRECIPITATION AND THUNDERSTORMS. EXPECT VFR AGAIN FRIDAY AND SATURDAY. CONFIDENCE TABLE... 23-05Z 05-11Z 11-17Z 17-23Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% MED 79% HIGH 100% KAVL HIGH 91% MED 67% MED 75% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% MED 79% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 82% 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...SBK NEAR TERM...MCAVOY/RWH SHORT TERM...WIMBERLEY LONG TERM...SBK AVIATION...RWH
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
542 PM MDT TUE MAY 13 2014 .SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT ISSUED AT 220 PM MDT TUE MAY 13 2014 LONG WAVE TROF JUST EAST OF THE CWA THIS MORNING WITH UPSTREAM RIDGE JUST OFF THE WEST COAST. LONG WAVES HAVE BEEN VERY SLOW MOVING LAST SEVERAL DAYS AND ARE FORECAST TO REMAIN NEARLY STATIONARY THROUGH THURSDAY. AMPLIFICATION THAT HAD BEEN UNDERWAY HAS CEASED. SO LITTLE CHANGE IN THE LONG WAVE PATTERN IS EXPECTED DURING THE SHORT TERM. WEAK SHORT WAVE TROFS ARE MOVING SOUTHWARD BEHIND THE LONG WAVE TROF OVER OUR CWA. ONE HAS EXITED THE AREA WITH ANOTHER VERY SUBTLE ONE JUST BARELY VISIBLE ON THE WATER VAPOR LOOP APPROACHING THIS AFTERNOON. HRRR MODEL HAS BEEN CONSISTENTLY SHOWING WIDELY SCATTERED SHOWERS DEVELOPING THIS AFTN OVER NE WYOMING AND THE BLACK HILLS...BUT WITH A BIT STRONGER AND MORE WELL ORGANIZED SHOWERS AND A FEW TSTMS FORECAST TO DEVELOP WITH THE SHORT WAVE LATE AFTN INTO THIS EVENING OVER NE WYOMING INTO THE BLACK HILLS. THERE IS SUPPORT FOR THIS DEVELOPMENT IN MODEST 700 MB Q VECTOR CONVERGENCE SHOWN BY THE NAM. TOMORROW NIGHT THERE IS A HINT OF ANOTHER WAVE...BUT LESS CERTAINTY ACCOMPANIES THIS FEATURE. CONVECTION IS ALSO SUGGESTED BY THE GFS FORECASTS OF 500MB TEMPERATURES NEAR 5 STANDARD DEVIATIONS BELOW THE SEASONAL MEAN. WITH STRONG SFC HEATING...THIS IMPLIES CONSIDERABLE INSTABILITY NEXT SEVERAL DAYS. STAYED CLOSE TO GUIDANCE WITH TEMPERATURES AND USED THE NAM FOR SURFACE WINDS...WITH SOME UPWARD ADJUSTMENT IN AFTN SPEEDS. BECAUSE WE HAVE BEEN QUITE COLD LATELY...I DECIDED NOT TO ISSUE FROST/FREEZE ADVISORY. && .LONG TERM...THURSDAY THROUGH TUESDAY ISSUED AT 220 PM MDT TUE MAY 13 2014 NORTHWEST FLOW WILL CONTINUE THROUGH THE END OF THE WEEK WITH FAST MOVING UPPER DISTURBANCES AND A NEARLY STATIONARY FRONTAL BOUNDARY OVER THE HIGH PLAINS. THIS WILL RESULT IN NEAR DAILY CHANCES FOR SHOWERS...ESPECIALLY OVER NORTHEAST WYOMING AND FAR WESTERN SOUTH DAKOTA. SLIGHTLY BELOW AVERAGE TEMPS ARE EXPECTED THROUGH THE END OF THE WEEK. AN UPPER TROUGH/CUT OFF LOW IS PROGGED TO DEVELOP EARLY NEXT WEEK OVER THE NW CONUS. UPPER FLOW WOULD THEN BECOME MORE SWRLY WITH WARM AND MOIST AIR ADVECTING IN FROM THE S/SE. THIS WILL INCREASE CHANCES FOR THUNDERSTORMS FOR THE EARLY PART OF NEXT WEEK ALONG WITH NEAR TO SLIGHTLY ABOVE AVERAGE TEMPERATURES. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 540 PM MDT TUE MAY 13 2014 ISOLD -SHRA WILL AFFECT NORTHEASTERN WYOMING INTO FAR SOUTHWESTERN SOUTH DAKOTA THIS EVENING. ADDITIONAL SHOWERS/THUNDERSTORMS POSSIBLE ON WEDNESDAY AFTERNOON. LCL MVFR VSBY WITH SHOWERS...OTHERWISE VFR CONDITIONS WILL PREVAIL. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...BARBER LONG TERM...77 AVIATION...7
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1214 AM CDT MON MAY 12 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 347 PM CDT SUN MAY 11 2014 COMPLEX FORECAST CONTINUES THIS AFTERNOON INTO THE OVERNIGHT. CURRENT ANALYSIS SHOWS SURFACE LOW PRESSURE OVER WESTERN KANSAS. KIND OF A DUAL WARM FRONT SIGNATURE. WITH MAIN AND STRONGEST WARM FRONT ACROSS FAR SOUTHERN NEBRASKA INTO SOUTHWEST IOWA...WHICH WAS REINFORCED BY THE OVERNIGHT MCS. MODELS IN GOOD AGREEMENT WITH THE POSITION OF THIS FRONT...AND ALL GUIDANCE SUGGESTS IT WILL ONLY SLOWLY MOVE NORTH TODAY. THIS IS THE AREA...SOUTHEASTERN NEBRASKA INTO SOUTHWESTERN IOWA...AT GREATEST RISK FOR SEVERE WEATHER AND TORNADOES...AS HIGHLIGHTED BY THE SPC OUTLOOK. FURTHER NORTH WE HAVE A SECONDARY WARM FRONT RUNNING FROM THE TRIPLE POINT OVER SOUTHERN NEBRASKA...NORTHEAST TO JUST SOUTH OF STORM LAKE. MARGINAL SURFACE INSTABILITY IS BEGINNING TO FORM IN THIS AREA...ALTHOUGH MOST OF IT IS REMAINING SOUTH OF OUR CWA. ALSO LARGE SCALE LIFT INCREASING ON THE NOSE OF A PV WAVE IS HELPING TO TRIGGER ELEVATED SHOWERS AND THUNDERSTORMS ACROSS THE NORTHWEST HALF OF THE CWA. THESE SHOULD STAY BELOW SEVERE LIMITS AND PUSH NORTH OF THE AREA BY THIS EVENING. DAYTIME HEATING AND INCREASING FORCING HAS ALSO HELPED FIRE CONVECTION ACROSS SOUTH CENTRAL NEBRASKA. THE STRONGEST SURFACE BASED SUPERCELLS WILL LIKELY RIDE FROM NEAR THE SOUTHERN WARM FRONT TO THE SECONDARY WARM FRONT...AND THUS STAY SOUTH OF OUR CWA. ALTHOUGH WILL NEED TO WATCH AREAS FROM SIOUX CITY TO STORM LAKE. LOW LEVELS REMAIN STABLE...BUT ENOUGH DESTABILIZATION IS POSSIBLE FOR STORMS MOVING INTO THIS AREA TO TAP INTO THE NEAR SURFACE LAYER. IF THIS HAPPENED AN ISOLATED TORNADO WOULD BE POSSIBLE. WHILE THIS STILL SEEMS TO BE A LOW THREAT...IT IS NOT IMPOSSIBLE AND WILL NEED TO MONITOR TRENDS. SEEMS MORE LIKELY THAT STORMS THAT FORM AND MOVE INTO OUR CWA WILL STAY ELEVATED...BASED ABOVE THE LOW LEVEL STABLE LAYER. DECENT ELEVATED INSTABILITY SHOULD INCREASE AND COULD MAKE IT ALL THE WAY TO ALMOST THE JAMES RIVER. QUESTION IS HOW MUCH MOISTURE WE CAN GET ADVECTED INTO THE CWA...WITH THE CONVECTION TO OUR SOUTH HAMPERING THIS TO A DEGREE. SEEMS LIKE A GOOD BET THAT NORTHWEST IOWA AND SOUTHWEST MINNESOTA WILL GET INTO THE ACTION...LESS CERTAIN FURTHER NORTHWEST. WITH THE ELEVATED WARM FRONT WELL TO OUR NORTH...EVEN PARCELS LIFTED FROM NEAR 750 MB SHOULD HAVE AROUND 40 KTS OF SHEAR TO WORK WITH. SO THOUGHT IS ELEVATED SUPERCELLS WILL BE POSSIBLE IF WE CAN GET THE MOISTURE AND ELEVATED INSTABILITY INTO THE AREA. MAIN THREAT WOULD BE LARGE HAIL WITH ANY STORM. AGAIN HIGHEST SEVERE THREAT SHOULD BE ACROSS NORTHWEST IOWA AND ADJACENT AREAS OF SOUTHWEST MINNESOTA WHERE CONFIDENCE IS HIGHEST ON INSTABILITY...THREAT IS MORE CONDITIONAL TOWARDS INTERSTATE 29. DO LIKE THE HRRR IDEA OF PUSHING EVERYTHING EAST BY LATER THIS EVENING AS STORMS ORGANIZE AND HELP PUSH THE FRONT EATS OF THE CWA. STILL COULD BE SOME SCATTERED SHOWERS...BUT MOST OF THE OVERNIGHT MAY END UP FREE OF HEAVY RAIN. ANOTHER PUSH OF THETAE ADVECTION LATE TONIGHT INTO EARLY MONDAY AS THE WHOLE SYSTEM BEGINS MOVING NORTHEAST. PRETTY GOOD LARGE SCALE LIFT TOO AS A STRONG JET ROUNDS THE BASE OF THE TROUGH. THUS THINKING PRECIPITATION COVERAGE WILL RAPIDLY INCREASE LATER TONIGHT INTO TOMORROW. MOST OF THIS WEST OF THE JAMES RIVER WILL BE MORE STABLE SHOWERY PRECIPITATION. DOES LOOK LIKE ELEVATED INSTABILITY WILL REMAIN TO THE EAST...THUS SHOULD GET SOME THUNDER OUT OF THE ACTIVITY. MAYBE EVEN SOME MARGINALLY SEVERE HAIL LATE TONIGHT INTO MONDAY MORNING GIVEN THE WIND PROFILES IF ENOUGH INSTABILITY IS PRESENT. ANY SURFACE BASED SEVERE WEATHER SHOULD STAY EAST OF THE CWA. SO OVERALL MONDAY LOOKS LIKE A PRETTY WET DAY WITH HIGHS IN THE 40S AND 50S. WINDS WILL BE ON THE INCREASE AS WELL...WITH AROUND 35 KTS AT 925 MB. WILL BE VERY CLOSE TO WIND ADVISORY CRITERIA ALONG AND WETS OF THE JAMES RIVER...WITH GUSTS APPROACHING 40 KTS. GIVEN EXPECTED WEAK MIXING DUE TO THE RAIN AND MARGINAL WINDS ALOFT...WILL HOLD OFF ON AN ADVISORY FOR NOW. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 347 PM CDT SUN MAY 11 2014 IN THE LONGER TERM...THE WEATHER IS HIGHLIGHTED BY MUCH BELOW NORMAL TEMPERATURES FOR A BULK OF THE UPCOMING WEEK. FOR MONDAY NIGHT...DECIDED TO RAISE POPS TO A LOW END LIKELY CATEGORY IN SOME OF OUR WESTERN ZONES. ALTHOUGH THE GFS IS DRY BY MONDAY EVENING... THE HIGHER RESOLUTION MODELS DO HANG BACK DEEPER RESIDUAL MOISTURE IN OUR FORECAST AREA...ESPECIALLY FOR LOCATIONS WEST OF I 29. IN ADDITION...BOTH THE NAM AND GFS SHOW TROWALING MONDAY EVENING IN THE 305-315K LAYER. STILL...RAINFALL WILL BE LIGHT EVEN IN OUR WESTERN ZONES...WITH OUR EASTERN ZONES NOT SEEING MUCH OF A RAINFALL POTENTIAL. ALTHOUGH COOL...THE CLOUD COVER AND WIND WILL HELP OUR LOWS FROM PLUMMETING TOO FAR MONDAY NIGHT WITH READINGS MOSTLY A COUPLE OF DEGREES EITHER SIDE OF 40. THEN THE UPPER LOW BEGINS TO MEANDER ACROSS SOUTHERN CANADA AND THE NORTHERN MS VALLEY ALL THE WAY FROM TUESDAY THROUGH THURSDAY... EVENTUALLY LIFTING INTO THE WESTERN GREAT LAKES BY FRIDAY. THEREFORE VERY CHILLY WEATHER FOR THIS TIME OF YEAR WILL FOLLOW SUIT. EVEN THE BIAS CORRECTED TEMPERATURES ARE NOW COLD...AND THEY HAVE BEEN THE BEST RECENTLY IN OUR FORECAST AREA IN CAPTURING WARM... MIXED OUT TEMPERATURES DURING THE DAYTIME. INSTABILITY CU WILL POP ON TUESDAY WITH A STRONG UPPER CYCLONIC FLOW EXISTING...WITH A SMALL CHANCE FOR LIGHT SHOWERS AROUND BROOKINGS AND SOUTHWEST MN. AFTER SUNSET...SKIES WILL CLEAR TUESDAY NIGHT FOLLOWED BY SOME MORE INSTABILITY DAYTIME CU ON WEDNESDAY...AND THERE ARE STRONG INDICATIONS THAT A SHORT WAVE WILL DIVE DOWN THE NORTHWEST FLOW ALOFT GIVING THE POSSIBILITY OF MORE WIDELY SCATTERED LIGHT SHOWERS ACROSS THE ENTIRE FORECAST AREA. BUT LOW POPS ARE STILL WARRANTED AS A QUESTION EXISTS AS TO HOW MUCH OF THIS RAINFALL WILL ACTUALLY MEASURE. ULTIMATELY...THIS SHORT WAVE WILL REINFORCE THE PARENT UPPER LOW AND KEEP OUR CYCLONIC FLOW GOING WITH A FEW SHOWERS AGAIN POSSIBLE ON THURSDAY. AS MENTIONED ABOVE...TUESDAY THROUGH THURSDAY WILL BE COLD WITH HIGHS ONLY IN THE 50S TO AROUND 60. FURTHERMORE...MIXED LAYER WINDS ARE STOUT ON TUESDAY PROMISING BREEZY CONDITIONS...LESS SO ON WEDNESDAY BUT STILL THE WIND WILL BE STRONG ENOUGH TO GIVE A RATHER RAW DAY. ONE THING TO WATCH FOR BOTH TUESDAY NIGHT AND WEDNESDAY NIGHT AS SKIES CLEAR AFTER SUNSET AND WINDS SUBSIDE...IS THE POSSIBILITY OF FROST HERE AND THERE. DID NOT PUT THEM IN THE GRIDS YET...AND CERTAINLY DID NOT ISSUE ANY FROST HEADLINES. BUT SOME OF OUR LOWS DO FALL INTO THE MID 30S SO WOULD NOT BE SURPRISED TO SEE SOME LIGHT FROST IN LOW LYING AREAS. FURTHER OUT FRIDAY THROUGH SUNDAY...THE UPPER LOW FINALLY MOVES INTO THE GREAT LAKES...THE NORTH OF THE GREAT LAKES ALLOWING THE FLOW TO BECOME QUASI ZONAL. THERE MAY BE SOME WARM AIR ADVECTION SHOWERS ON SUNDAY AS THE NEXT UPPER TROUGH BEGINS TO DIG DOWN THE WESTERN U.S. COAST. THEREFORE HIGHS WILL FINALLY WARM UP INTO THE 60S FRIDAY THROUGH SUNDAY WITH LOWS ALSO MODERATING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1204 AM CDT MON MAY 12 2014 WIDESPREAD SHOWERS AND STORMS HAVE MOVED EAST OF THE AREA...HOWEVER COULD SEE AN ADDITIONAL CLUSTER OF SHOWERS AND STORMS MOVE ACROSS OUR FAR SOUTHEAST COUNTIES...INCLUDING KSUX THROUGH AROUND 09Z. ANOTHER BAND OF RAINFALL IS EXPECTED TO LIFT ACROSS SOUTHEAST SOUTH DAKOTA...WITH MORE SCATTERED COVERAGE INTO SOUTHWEST MINNESOTA AFTER 07Z. ALONG WITH OCCASIONAL RAINFALL...MVFR TO IFR CEILINGS ARE EXPECTED TO SPREAD NORTHEAST...BECOMING WIDESPREAD OVERNIGHT. THESE CEILINGS WILL STICK AROUND THROUGH THE DAY ON MONDAY AND COULD BEGIN LIFTING ACROSS THE WEST AFTER 00Z TUESDAY...POSSIBLY ALSO NEAR THE MISSOURI VALLEY...INCLUDING KHON AND KSUX. WINDS WILL BE GUSTY FROM THE NORTHWEST THROUGHOUT THE PERIOD...AVERAGING 15 TO 25 KT WITH GUSTS AS HIGH AS 35 KT. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...CHENARD LONG TERM...MJ AVIATION...
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
833 PM CDT TUE MAY 13 2014 .UPDATE... A STRONG COLD FRONT STRETCHED FROM AROUND PARIS TN TO TO NEAR OXFORD MS THIS EVENING. THE FRONT WILL GRADUALLY STALL ACROSS THE AREA TONIGHT WITH BROAD SOUTHWESTERLY FLOW ALOFT. A FEW THUNDERSTORMS LINGER ALONG THE FRONT BUT HAVE WEAKENED IN INTENSITY FROM EARLIER THIS AFTERNOON AS MLCAPES HAVE DECREASED TO BETWEEN 500 AND 1000 J/KG. THE HRRR MODEL CONTINUE TO INDICATE WIDESPREAD RAIN PUSHING INTO MUCH OF THE MIDSOUTH OVERNIGHT FROM THE SOUTHWEST...ESPECIALLY ALONG AND BEHIND THE FRONT...AS A SHORT WAVE EMBEDDED IN THE SOUTHWEST FLOW ALOFT MOVES TOWARD THE REGION. MUCH COOLER AIR WILL ALSO CONTINUE TO MOVE INTO THE AREA BEHIND THE FRONT. HAVE ALREADY UPDATED THE ZONE FORECASTS AND GRIDS TO MAKE A FEW TWEAKS FOR TONIGHT...BUT THE FORECAST REMAINS ON TRACK. LEFT THE FLASH FLOOD WATCH AS IS FOR EASTERN AR AND THE MO BOOTHEEL. THUNDERSTORMS ARE EXPECTED TO INCREASE IN INTENSITY ALONG AND AHEAD OF THE FRONT BY LATE WEDNESDAY MORNING INTO AFTERNOON WITH A FEW STORMS POSSIBLY SEVERE FROM THE SOUTHEASTERN CORNER OF WEST TN NEAR THE TN RIVER INTO NORTHEAST MS. JCL && .DISCUSSION... /ISSUED 343 PM CDT TUE MAY 13 2014/ A LARGE UPPER LEVEL TROUGH REMAINS STRETCHED FROM THE UPPER MISSISSIPPI VALLEY SOUTHWESTWARD ACROSS THE SOUTHERN PLAINS THIS AFTERNOON. A POTENT SHORTWAVE EMBEDDED WITHIN THE BASE OF THE UPPER TROUGH CONTINUES TO MOVE EAST ACROSS EASTERN NEW MEXICO THIS AFTERNOON. THIS SHORTWAVE WILL BE THE FOCUS FOR EXPECTED WEATHER CONDITIONS TONIGHT AND WEDNESDAY. IN THE SHORT-TERM...A SLOW MOVING COLD FRONT ALIGNED ALONG THE MISSISSIPPI RIVER AS OF 20Z CONTINUES TO PUSH SLOWLY EASTWARD. SCATTERED SHOWERS AND THUNDERSTORMS ARE FORMING LATE THIS AFTERNOON JUST AHEAD OF THE FRONT. THESE STORMS HAVE FORMED IN A MODERATELY UNSTABLE AND LOW SHEAR ENVIRONMENT. MLCAPES IN A CORRIDOR JUST AHEAD OF THE FRONT RANGE FROM 1000-1500 J/KG WITH LOW LEVEL LAPSE RATES APPROACHING 8.0 C/KM. THIS HAS ALLOWED STORMS TO BECOME STRONG THIS AFTERNOON IN THESE AREAS WITH THE POTENTIAL FOR STRONG GUSTY WINDS AND SMALL HAIL. MEAGER MID LEVEL LAPSE RATES AND WEAK SHEAR WILL LIKELY KEEP STORMS OF THE PULSE VARIETY AND MAINLY BELOW SEVERE LIMITS. THESE SHOWERS AND STORMS SHOULD CONTINUE INTO THE EVENING WITH A REDUCTION IN INTENSITY AND COVERAGE LATER THIS EVENING. BY LATER TONIGHT...THE AFOREMENTIONED SHORTWAVE OVER THE SOUTHERN PLAINS WILL CONTINUE TO MOVE EASTWARD WITH FALLING MID LEVEL HEIGHTS...ESPECIALLY ACROSS WESTERN AREAS AFTER MIDNIGHT. SHOWERS AND THUNDERSTORMS SHOULD EXPAND IN COVERAGE LATE TONIGHT ESPECIALLY ON THE COOL SIDE OF THE SLOW MOVING COLD FRONT WHICH SHOULD MOVE AS FAR EAST AS WEST TENNESSEE INTO NORTHWEST MISSISSIPPI BY SUNRISE WEDNESDAY MORNING. THUNDERSTORMS MAY PRODUCE HEAVY RAINFALL ACROSS WESTERN PORTIONS OF THE MID SOUTH. THE POTENTIAL FOR FLOODING REMAINS SOMEWHAT BORDERLINE...BUT CONSIDERING THE FACT THAT FLASH FLOOD GUIDANCE IS LOW AND CONVECTIVE COVERAGE SHOULD EXPAND LATER TONIGHT INTO WEDNESDAY MORNING...WILL LEAVE THE FLASH FLOOD WATCH IN PLACE. THE SHORTWAVE WILL CONTINUE TO DIG OVER THE MID SOUTH ON WEDNESDAY AS IT TAKES ON AN INCREASINGLY NEUTRAL TO EVEN SLIGHTLY POSITIVE TILT. AS MID LEVEL HEIGHT FALLS ASSOCIATED WITH THE SHORTWAVE BEGIN TO OVERTAKE THE SURFACE FRONT AND OVERSPREAD THE WARM SECTOR STILL IN PLACE OVER PORTIONS OF WEST TENNESSEE...NEAR THE TENNESSEE RIVER...AND NORTHEAST MISSISSIPPI....THE ATMOSPHERE SHOULD FURTHER DESTABILIZE BY LATE MORNING INTO EARLY AFTERNOON. THE UPPER LEVEL FORCING AND ASSOCIATED 70 KT CYCLONICALLY CURVED MID LEVEL JET SHOULD HELP TO INDUCE A SURFACE WAVE OF LOW PRESSURE THAT WILL LIFT NORTHEAST ALONG THE FRONT OVER EASTERN PORTIONS OF THE FORECAST AREA THROUGH WEDNESDAY AFTERNOON. DEEP LAYER SHEAR SHOULD STRENGTHEN OVER THE AREA AS THE ATMOSPHERE BECOMES SOMEWHAT UNSTABLE OVER EASTERN SECTIONS OF THE REGION. NUMEROUS THUNDERSTORMS SHOULD DEVELOP AND INTENSIFY ALONG AND AHEAD OF THE FRONT. LOW LEVEL DIRECTIONAL SHEAR IN ADVANCE OF THE SURFACE FLOW SHOULD BECOME BACKED. CONSIDERING ALL OF THESE FACTORS...THERE WILL BE THE POTENTIAL FOR A FEW SEVERE STORMS TO DEVELOP ACROSS PORTIONS OF WEST TENNESSEE...NEAR THE TENNESSEE RIVER...AND NORTHEAST MISSISSIPPI ON WEDNESDAY. THE PRIMARY SEVERE WEATHER THREATS SHOULD BE DAMAGING WINDS AND A FEW TORNADOES. A SLIGHT RISK FOR SEVERE STORMS EXISTS OVER THESE AREAS FOR TOMORROW. TIMING FOR THE SEVERE WEATHER THREAT WILL BE FROM LATE MORNING THROUGH THE AFTERNOON HOURS. TO THE WEST OF THE FRONT...VERY COOL CONDITIONS WILL PREVAIL WITH HIGH TEMPERATURES REMAINING IN UPPER 50S TO LOWER 60S. AHEAD OF THE FRONT...TEMPERATURES SHOULD RISE INTO THE MID AND UPPER 70S. AS THE SHORTWAVE MOVES NORTHEAST OF THE AREA BY EVENING AND THE SURFACE LOW LIFTS QUICKLY NORTHEAST...EXPECT THE COLD FRONT TO SWEEP EAST OF THE AREA WITH SHOWERS AND THUNDERSTORMS ENDING FROM WEST TO EAST THROUGH THE EVENING. DRY AND COOL CONDITIONS WILL RETURN BRIEFLY BY LATER WEDNESDAY NIGHT. ANOTHER SHORTWAVE ROTATING THROUGH THE UPPER TROUGH AND TO THE SOUTH OF A DEVELOPING UPPER LEVEL LOW PRESSURE SYSTEM OVER THE GREAT LAKES REGION WILL MOVE ACROSS THE MID SOUTH THURSDAY AFTERNOON AND EVENING. VERY COLD MID LEVEL TEMPERATURES AND STEEP MID LEVEL LAPSE RATES WILL SUPPORT ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS THURSDAY AFTERNOON AND EVENING. THE GREATEST COVERAGE SHOULD REMAIN ACROSS NORTHEAST ARKANSAS AND THE MISSOURI BOOTHEEL INTO NORTHWEST TENNESSEE WHERE INSTABILITY WILL BE MAXIMIZED. A FEW OF THE STORMS MAY PRODUCE GUSTY WINDS AND SMALL HAIL. TEMPERATURES WILL BE HELD SEVERAL DEGREES BELOW NORMAL WITH HIGHS MAINLY IN THE MID TO UPPER 60S. THE UPPER LEVEL LOW WILL SLOWLY MOVE ACROSS THE GREAT LAKES THROUGH THE WEEKEND. A SERIES OF WEAKER SHORTWAVES SHOULD MOVE ACROSS THE REGION BRINGING PERIODIC CHANCES FOR SHOWERS AND CONTINUED BELOW AVERAGE TEMPERATURES. UPPER LEVEL RIDGING WILL FINALLY REBUILD BACK INTO THE REGION BY EARLY NEXT WEEK WITH A RETURN TO DRY WEATHER AND WARMER TEMPERATURES. JLH && .AVIATION... FOR 00Z TAF CYCLE COMPLICATED PATTERN WITH SCATTERED SHOWERS AND THUNDERSTORMS SO MIX OF MVFR AND VFR CONDITIONS. EXPECT MORE RAIN OVER NEXT 24 HOURS AND CEILINGS WILL BE LOW AS STORMS MOVE THROUGH EXPECTING PERIODS OF IFR CEILINGS AND MVFR VISIBLITY WITH RAIN. WINDS WILL SHIFT FROM NORTH/NORTHEAST TO NORTHWEST WEDNESDAY. WINDS SHIFT IN WEST EARLY WEDNESDAY...AFTERNOON IN MEMPHIS AND LATE AFTERNOON IN JACKSON/TN/. TLSJR && .MEG WATCHES/WARNINGS/ADVISORIES... AR...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR DUNKLIN-PEMISCOT. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1008 AM EDT MON MAY 12 2014 .DISCUSSION... AN UPPER-LEVEL RIDGE OF HIGH PRESSURE WILL REMAIN THE DOMINANT WEATHER FEATURE ACROSS THE FORECAST AREA TODAY...AND HAS PROMOTED MOSTLY CLEAR CONDITIONS ACROSS THE TENNESSEE VALLEY THIS MORNING /EXCEPTION OF A FEW BANDS OF HIGH CLOUDS MOVING OVER THE NORTHERN PLATEAU AND CENTRAL VALLEY/. THE ABUNDANT SUNSHINE AND WARM TEMPERATURES ALOFT/HIGH THICKNESS VALUES WILL ALLOW FOR A QUICK WARM-UP INTO THE LOW 80S BY MIDDAY AND A EVENTUALLY INTO THE MID TO UPPER 80S ACROSS MUCH OF THE VALLEY AGAIN BY THE AFTERNOON /WITH A FEW SPOTS APPROACHING 90 DEGREES/. WITH MOISTURE UNDERNEATH THIS RIDGE HOWEVER...THE SOME DIURNALLY DRIVEN CONVECTION IS EXPECTED /PRIMARILY ALONG THE EAST TENNESSEE/WESTERN NORTH CAROLINA MOUNTAINS/ THIS AFTERNOON AND EVENING. MODELS ARE ALSO SHOWING SOME ADDITIONAL CONVECTION FIRING ACROSS SOUTHERN KENTUCKY AND MAKING ITS WAY ALONG THE NORTHERN PLATEAU AND SOUTHWEST VIRGINIA BY THE AFTERNOON. GIVEN THIS...HAVE LOW-END MENTIONABLE POPS IN THESE AREAS AND CHANCE POPS ALONG THE MOUNTAINS /AS THIS ACTIVITY SHOULD BE ISOLATED TO SCATTERED IN NATURE/. HOWEVER...KEPT MENTIONABLE POPS OUT OF THE VALLEY FOR NOW AS THINK MODELS ARE OVER DOING IT SOMEWHAT WITH THE CAP STILL IN PLACE. THIS THINKING IS SUPPORTED WELL BY THE HRRR WHICH SHOWS CONVECTION PRIMARILY ALONG THE MOUNTAINS AND LATE MOVING INTO SW VIRGINIA. THERE WILL BE ENOUGH INSTABILITY LATER TO SUPPORT SOME STRONG STORMS CAPABLE OF GUSTY WINDS AND SMALL HAIL ALONG THE MOUNTAINS...WITH THE POTENTIAL FOR A ROGUE SEVERE STORM OR TWO. HOWEVER...GIVEN THE LACK OF ORGANIZATION...AM NOT ANTICIPATING ANYTHING MORE THAN A VERY ISOLATED SEVERE THREAT FOR THOSE AFOREMENTIONED AREAS ATTM. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 88 65 87 64 / 10 10 30 40 KNOXVILLE MCGHEE TYSON AIRPORT, TN 87 63 86 63 / 10 10 30 30 OAK RIDGE, TN 87 63 85 63 / 10 10 30 40 TRI CITIES AIRPORT, TN 85 60 84 60 / 20 10 30 30 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ AMP
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
931 PM CDT TUE MAY 13 2014 .DISCUSSION... AREA OF SHRA & ISO TSRA ASSOCIATED W/ UPPER TROF WILL BE PUSHING THRU OVERNIGHT. PRECIP IS A BIT FURTHER SOUTH THAN EARLIER GUIDANCE SUGGESTED IT WOULD BE SO EXPANDED HIGHER POPS CLOSER TO THE COAST. HRRR SEEMS TO HAVE A DECENT HANDLE ON THINGS ATTM AND GEARED SHORT TERM FCST TOWARD ITS SOLN. NOT EXPECTING THE MAGNITUDE OF ACCUMULATIONS WE SAW LAST NIGHT...BUT ANY ADDITIONAL RAIN REMAINS WELCOME FOR MOST PARTS. TEMPS LOOK GOOD SO NO UPDATES THERE. DID MOVE UP BEGIN TIME FOR THE SMALL CRAFT ADVY AS WINDS ARE PICKING UP AND ARE NEAR OR ABOVE CRITERIA FOR MOST WATERS. 47 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 55 70 48 77 53 / 70 20 10 0 0 HOUSTON (IAH) 59 70 50 79 55 / 70 20 10 0 0 GALVESTON (GLS) 63 72 57 76 64 / 60 30 10 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 4 PM CDT WEDNESDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
109 PM CDT MON MAY 12 2014 .AVIATION... MVFR CONDITIONS ARE EXPECTED FOR THIS FORECAST PERIOD AND WIDESPREAD DISRUPTIONS ARE EXPECTED THIS AFTERNOON AND EVENING DUE TO THUNDERSTORM ACTIVITY AFFECTING THE AREA. A COLD FRONT CONTINUES TO APPROACH FROM THE NORTHWEST. AT 1730Z... THE FRONT WAS LOCATED ALONG A LINE FROM JACKSBORO TO JUST WEST OF COMANCHE AND WAS MOVING EAST AROUND 14KTS. HOWEVER... THE SPEED OF THE FRONT MAY INCREASE DEPENDING ON THE INTENSITY OF THE CONVECTION ALONG THE BOUNDARY. WINDS WILL CONTINUE TO BE GUSTY BUT WILL SHIFT TO THE NORTH BEHIND THE FRONT. STORMS HAVE ALREADY BEGUN TO DEVELOP ALONG THE FRONT BUT CONVECTION WILL LIKELY AFFECT AREAS AHEAD OF THE PRIMARY WIND SHIFT. CONVECTION WILL BEGIN TO AFFECT DFW TAF SITES AROUND 20Z AND WACO AROUND 22Z. SOME OF THE STORMS MAY BE MARGINALLY SEVERE WITH A DAMAGING WIND THREAT BEING THE PRIMARY CONCERN. WINDS WILL LIKELY SHIFT TO THE NORTHWEST WITH CONVECTION ALONG THE FRONT. AMENDMENTS WILL LIKELY BE REQUIRED OVER THE NEXT COUPLE OF HOURS AS CONVECTION MOVES EAST TO ADDRESS WINDS/TIMING OF TSTMS. WHILE MVFR CONDITIONS ARE FORECAST...IFR VIS MAY BRIEFLY AFFECT TAF SITES DURING CONVECTION. IT WAS NOTED DURING THE MORNING CONVECTION THAT AFFECTED THE DFW METRO TAF SITES THAT THE RAINFALL APPEARED LIGHT ON RADAR...BUT RESULTED IN LOW VIS AND HIGHER RAINFALL AMOUNTS THAN EXPECTED. && .UPDATE... CURRENT FORECAST IS IN GOOD SHAPE AND HAVE ONLY MADE SOME COSMETIC CHANGES TO THE HOURLY DATA AND MORNING POPS. LATEST SURFACE ANALYSIS INDICATES THAT THE COLD FRONT IS LOCATED ALONG A LINE ACROSS CENTRAL OKLAHOMA INTO NORTHWEST TEXAS BETWEEN BOWIE AND WICHITA FALLS SOUTHWARD TO BRECKENRIDGE. AHEAD OF THE COLD FRONT AN AREA OF SHOWERS AND THUNDERSTORMS INITIATED ON WHAT APPEARS TO BE AN INITIAL WAVE OF FORCING OR A SOUTHWARD PROPAGATING GRAVITY WAVE. EITHER WAY...AMDAR SOUNDING DATA FROM DFW AIRCRAFT INDICATE THAT STRONG CAPPING INVERSION NOTED ON 12Z FWD SOUNDING WAS ALL BUT COMPLETELY ERODED IN ABOUT 45 MINUTES. THIS INITIAL WAVE OF ACTIVITY HAS FAILED TO ORGANIZE OR REALLY TAKE OFF IN INTENSITY WHICH HAS LEFT THE LOW LEVEL WINDS AND MOISTURE IN PLACE BEHIND IT. THIS WILL LIKELY HELP TO INITIATE MORE ROBUST THUNDERSTORM ACTIVITY OVER THE NEXT FEW HOURS AS THE FRONT CONTINUES TO MOVE SOUTH. LATEST OBJECTIVE ANALYSIS ACROSS NORTH TEXAS SHOWS AROUND 2000 J/KG OF SURFACE BASED INSTABILITY SOUTH/EAST OF THE FRONT WHERE THE SUN HAS COME OUT A BIT WITH LITTLE INHIBITION LEFT. EXPECT THUNDERSTORMS TO BECOME MORE NUMEROUS IN COVERAGE THROUGH EARLY AFTERNOON. THE SEVERE THREAT REMAINS ACROSS NORTH TEXAS...ESPECIALLY GIVEN THE STRONG INSTABILITY...HOWEVER DEEP LAYER SHEAR ISNT ALL THAT STRONG SO MULTICELL CLUSTERS ARE EXPECTED. SOME SEVERE WIND GUSTS WOULD BE POSSIBLE ALONG WITH SEVERE HAIL. THE MORE SIGNIFICANT THREAT WILL BE FOR VERY HEAVY RAINFALL AND FLASH FLOODING...ESPECIALLY ACROSS THE EASTERN COUNTIES WHERE THE FRONT IS EXPECTED TO SLOWLY MOVE THROUGH TONIGHT. SOME AREAS COULD PICK UP IN EXCESS OF 3 INCHES OF RAIN IN A SHORT PERIOD OF TIME WITH ADDITIONAL RAINFALL PERSISTING INTO TONIGHT. DUNN && .PREV DISCUSSION... /ISSUED 437 AM CDT MON MAY 12 2014/ THE POTENT UPPER LEVEL LOW OVER THE FOUR CORNERS THAT WAS RESPONSIBLE FOR SNOW IN DENVER YESTERDAY WILL EJECT NORTHEAST OUT INTO THE PLAINS TODAY...BUT ADDITIONAL UPPER ENERGY WILL DROP INTO THE BASE OF A DEEPENING LONGWAVE TROUGH TODAY. THIS UPPER TROUGH WILL ENGULF THE CENTRAL US BY TOMORROW...A PATTERN THAT IS VERY UNUSUAL FOR MID MAY. THIS SYSTEM HAS TAPPED INTO A CANADIAN AIRMASS AND HAS SENT AN UNSEASONABLY STRONG COLD FRONT BARRELING SOUTH. AT 4AM...THIS FRONT WAS LOCATED JUST SOUTH OF LUBBOCK TO NEAR VERNON TO EL RENO OKLAHOMA AND WAS MOVING SOUTHEAST AT 15 TO 20MPH. THE FRONT IS AHEAD OF MOST MODEL PROJECTIONS...WHICH IS NOT SURPRISING GIVEN THE COLD AIR BEHIND IT. THE RAP HAS A GOOD HANDLE ON THE FRONT/S SPEED AND IT WILL BE USED FOR TIMING. THE FRONT WILL ARRIVE INTO THE NORTHWEST CWA BY MID-MORNING AND CONTINUE TO TRACK SOUTHEAST...BUT SLOW DOWN A BIT DUE TO DAYTIME HEATING. THE FRONT SHOULD REACH A SHERMAN TO DFW TO COMANCHE LINE BY MID-AFTERNOON. THE AIRMASS AHEAD OF THE FRONT WILL BE WARM AND MOIST...WITH SEVERAL DAYS OF SOUTHERLY FLOW NOW BRINGING PRECIPITABLE WATER VALUES UP TO 1.75 TO 2 INCHES. SURFACE BASED CAPE WILL PEAK AROUND 2000-2500 J/KG THIS AFTERNOON AS TEMPS WARM INTO THE MID 80S. DAYTIME HEATING AND FORCING FOR ASCENT FROM THE UPPER LEVEL TROUGH WILL LIFT/ERODE THE WEAK CAPPING INVERSION...AND THUS CONVECTION WILL INCREASE IN COVERAGE ALONG THE FRONT BY LATE MORNING. BULK LAYER SHEAR IS FAIRLY WEAK...ON THE ORDER OF 25KT...SO MULTICELLULAR CONVECTIVE MODES ARE EXPECTED. GIVEN THE HIGH INSTABILITY AND WEAK SHEAR...SOME SEVERE WIND/HAIL REPORTS ARE POSSIBLE TODAY WITH THE STRONGEST STORMS. CONVECTION ALONG THE FRONT WILL LIKELY CONGEAL INTO A SOLID LINE OF THUNDERSTORMS BY MID-AFTERNOON...WITH THE LINE CONTINUING TO GROW UPSCALE INTO A FORMIDABLE LINEAR MCS BY THE EVENING HOURS. MCS PROPAGATION VECTORS AND DIFFLUENT THICKNESS FIELDS ALOFT SUGGEST THAT THE MOVEMENT OF THIS SYSTEM WILL REMAIN FAIRLY SLOW...LIKELY LESS THAN 10-15MPH. THIS FORWARD SPEED SHOULD IN THEORY LIMIT THE DAMAGING WIND THREAT THIS EVENING OVER THE SOUTHEAST HALF OF THE CWA...BUT WILL RESULT IN ENHANCED RAINFALL TOTALS. THE MCS WILL LIKELY HAVE SLOWER WEST TO EAST MOVEMENT THAN NORTH TO SOUTH...AND THUS THE ORIENTATION OF THE LINE SUGGESTS THAT EASTERN ZONES WILL HAVE A GREATER RISK FOR PROLONGED HEAVY RAINFALL. EXPECT THE LINE TO PUSH THROUGH THE SOUTHWEST ZONES FAIRLY QUICKLY...LIKELY REACHING A LAMPASAS TO WACO LINE BY 6 PM. A TIGHT RAINFALL GRADIENT IS FORECAST OVER THE CWA WITH LESS THAN A HALF INCH EXPECTED OVER THE NW ZONES...TO 1-2 INCHES IN A BAND FROM THE SHERMAN AREA TO THE METROPLEX TO COMANCHE...AND 2-3 INCHES SOUTH AND EAST OF A PARIS TO GREENVILLE TO HILLSBORO LINE. THIS LATTER REGION WAS THE SAME AREA THAT RECEIVED A SWATH OF 2-4 INCHES OF RAIN THURSDAY AND SOILS ARE ALREADY SATURATED. THUS A FLASH FLOOD WATCH WAS ISSUED FOR LOCATIONS ALONG AND SOUTHEAST OF A BONHAM TO DALLAS TO TEMPLE LINE. WHILE WE DONT EXPECT MOST OF DALLAS AND COLLIN COUNTIES TO RECEIVE MORE THAN 2 INCHES...GIVEN THE URBAN DEVELOPMENT THERE AND THE FACT THAT THE SOUTHEAST PARTS OF THESE COUNTIES DID SEE OVER 4 INCHES...FELT IT WAS BEST TO INCLUDE THEM. FARTHER SOUTH...FROM WACO TO ATHENS...LESS RAIN FELL IN THIS AREA LAST THURSDAY...BUT QUICK TOTALS OF 2-3 INCHES ARE POSSIBLE THIS EVENING. FOR WACO/TEMPLE/KILLEEN ONLY AROUND 2 INCHES ARE FORECAST...BUT AGAIN URBAN INFRASTRUCTURE MAY EXACERBATE ANY FLOODING...SO THEY WERE INCLUDED IN THE WATCH TOO. BECAUSE THE UPPER LEVEL TROUGH WILL BE SLOW TO MOVE EAST...CONTINUED SOUTHERLY FLOW ALOFT BEHIND THE FRONT/LINE OF STORMS WILL OCCUR THIS EVENING. THUS THE LINE OF STORMS WILL LIKELY BE SUCCEEDED BY A FEW HOURS OF STEADY LIGHT TO MODERATE STRATIFORM RAINS...ESPECIALLY ACROSS THE WATCH AREA. THIS ACTIVITY SHOULD END FROM NORTHWEST TO SOUTHEAST LATE TONIGHT...BUT MAY LINGER OVER THE SOUTHEAST ZONES INTO TUESDAY MORNING. TUESDAY SHOULD BE DRY FOR THE REMAINDER OF THE AREA WITH MOSTLY CLOUDY AND COOL CONDITIONS AS COOLER AIR POURS INTO THE REGION BEHIND THE FRONT. FORECAST HIGH TEMPS MAY BE TOO WARM...BUT IT WOULD ONLY TAKE AN HOUR OR TWO OF AFTERNOON MAY SUNSHINE TO WARM US INTO THE MID 60S...SO STAYED CONSERVATIVE THERE. THE STRONGEST UPPER LEVEL FORCING WILL CROSS THE REGION TUESDAY EVENING BUT THE AIRMASS WILL BE PRETTY WORKED OVER. HOWEVER THIS FORCING SHOULD RESULT IN SCATTERED ELEVATED SHOWERS AND A FEW STORMS OVER THE REGION AND SHOULD SQUEEZE OUT ANOTHER TENTH TO QUARTER INCH OF RAINFALL. HAVE BUMPED POPS UP TUESDAY NIGHT AS MODEL GUIDANCE HAS COME INTO BETTER AGREEMENT ON THIS ROUND. OTHERWISE THE REMAINDER OF THE FORECAST LOOKS QUIET AND VERY NICE FOR MID TO LATE MAY. DRY NORTHWESTERLY FLOW ALOFT WILL PREVAIL THROUGH THE WEEKEND LEADING TO CLEAR SKIES AND LIGHT WINDS. GOOD RADIATIONAL COOLING WEDNESDAY NIGHT WILL SEND LOW TEMPS DOWN INTO THE 40S AREA WIDE...AND WACO MAY BREAK ITS RECORD LOW OF 46. HIGHS IN THE UPPER 60S ARE EXPECTED THURSDAY...BUT TEMPS SHOULD WARM INTO THE 70S FRIDAY AND THE 80S BY THE WEEKEND. DRY WEATHER WILL CONTINUE INTO NEXT WEEK WITH TEMPS WARMING TO ABOVE NORMAL. TR.92 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 83 54 66 51 68 / 90 80 20 40 10 WACO, TX 87 57 65 51 69 / 70 100 40 60 10 PARIS, TX 84 56 63 51 64 / 70 90 20 50 20 DENTON, TX 80 52 65 49 68 / 80 70 20 40 10 MCKINNEY, TX 83 53 64 50 68 / 90 80 20 40 10 DALLAS, TX 84 55 65 52 68 / 90 80 20 50 10 TERRELL, TX 85 57 64 51 67 / 70 90 20 50 20 CORSICANA, TX 86 59 64 52 67 / 60 100 40 60 20 TEMPLE, TX 87 58 64 52 69 / 50 100 50 60 10 MINERAL WELLS, TX 80 50 66 47 71 / 70 60 20 30 10 && .FWD WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 4 PM CDT THIS AFTERNOON THROUGH LATE TONIGHT FOR TXZ094-095-104>107-119>123-134-135-145>148-158>162- 174-175. && $$ /
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1250 PM CDT MON MAY 12 2014 .AVIATION... /18Z TAFS/ A cold front has moved into the southeast half of the CWA this afternoon, with showers and thunderstorms developing in the warm sector. The greatest threat for thunderstorms will be from the KBWD, to KBBD, to KJCT terminals. VCTS remarks were included through early evening in these areas with winds eventually shifting to the northwest as the front moves slowly south. Behind the front, winds will remain from the northwest at near 15 kts, gusting up to 25 kts at times. MVFR ceilings will continue for a bit longer at KABI but VFR conditions will persist at KSJT. More widespread rain will be possible over the southeast terminals overnight, mainly at KJCT. The NAM model is suggesting very low clouds continuing across the southeast through the period but the GFS looks more reasonable, keeping prevailing ceilings above 3000 ft. Johnson && .PREV DISCUSSION... /ISSUED 1131 AM CDT MON MAY 12 2014/ UPDATE... The cold front is just a bit ahead of schedule, currently bifurcating the CWA from southwest to northeast (Ozona, to Paint Rock, to Cross Plains). Winds are from the north at 15-20 mph in the wake of this front. Temperatures remain in the 60s in areas that experienced the frontal passage early this morning, but have only regressed into the mid 70s at locations where the front as arrived in the past 1-2 hours. I lowered max temps across the Big Country and western Concho Valley a few degrees with only minor tweaks needed elsewhere. Other minor changes were made to the dewpoint/wind grids to account for the faster cold front. Convection is just now beginning to ramp up in the warm sector, primarily from Paint Rock to Brownwood. The EMC RAP meso-analysis provided by the SPC indicates MLCAPE values of 2000-3000 J/kg across the area with little/no CINH. Effective shear has increased over the past few hours and should be supportive of organized convection this afternoon and early this evening. Steep mid-level lapse rates will promote hail growth, however, the drier air behind this front may push the severe threat east of the area by early evening. During the late afternoon and evening hours, this convection should grow upscale, decreasing the severe threat and becoming more of a heavy rain producer. PREV DISCUSSION... /ISSUED 634 AM CDT MON MAY 12 2014/ AVIATION... /12Z TAFS/ Stratus will remain over the Heartland and Northwest Hill Country through mid morning and then will dissipate. Going with MVFR CIGS at the KJCT and KBBD terminals until 16Z. Mainly VFR conditions are expected the rest of the TAF forecast. Isolated to scattered thunderstorms will be possible east of an Abilene to San Angelo line mainly this afternoon and tonight. Storms may even be more numerous by tonight east of a Coleman to Junction line. The models are developing an MCS along a cold front by 06Z Tuesday and moving it slowly east into central Texas. However, confidence is only high enough to add VCTS to the terminals through 02Z Tuesday. Winds will be south and then become north as cold front moves through West Central Texas today and this evening. PREV DISCUSSION... /ISSUED 442 AM CDT MON MAY 12 2014/ SHORT TERM... (Today and Tonight) WV imagery this morning was showing and a strong upper level trough over the central and southern Rockies with a mid level speed max of 50 to 70 knots rotating out in the Plains. Upper level flow has backed to southwest over Texas. Also, a lot mid and upper subsidence evident which is still resulting in a strong cap over West Central Texas. At the surface, a cold front was located along a Quanah to Seminole line. A dryline extended south along a Wink to Sanderson line. Not much happening yet convection wise as low level inhibition and cap is still holding strong. A few showers have developed just behind the cold front across northwest Texas. The airmass was very moist across our area with southerly flow and dewpoints in the mid to upper 60s. For today, the chance of showers and thunderstorms will increase mid morning through the afternoon across mainly the eastern half of the CWFA. The cold front will continue southeast into West Central Texas and will probably slow its forward speed. Scattered showers and thunderstorms will develop along and behind the front as elevated instability erases the cap. The HRRR convective allowing model is showing best coverage of activity east of an Abilene to San Angelo line. The combination of good instability in the warm sector and weak 0-6KM shear of 25 to 30 knots will result in multicell storms with possible brief supercell structures. A few strong to severe storms are possible across mainly the Heartland and Northwest Hill Country. The main hazards will be large hail, damaging winds and dangerous cloud to ground lightning. Going with mainly chance to slight chance POPS for today. Temperatures will be cooler with highs in the 80s. For tonight, There will be a chance of showers thunderstorms across much of our area with better coverage of storms east of a Coleman to Sonora line. a few storms may be severe. The main hazards will be large hail, damaging winds and dangerous cloud to ground lightning mainly before 06Z Tuesday. The bigger focus will be the potential for locally heavy rainfall across the Heartland and Northwest Hill Country, due to good low level southerly flow. moisture flux convergence along a slow moving cold front, PWAT values of 1.5 to 1.75 inches and in the RRQ of highly amplified 250MB jet. Rainfall amounts of 1 to 2 inches with locally heavy amounts are possible along and east of a Brownwood to Junction line. Also, going with LKLY to CAT POPS across the southeast CWFA. LONG TERM... (Tuesday through next Monday) The cold front will be well south of the area early Tuesday morning, with the upper level trough axis over New Mexico. Showers and thunderstorms may be ongoing across far southeast sections early Tuesday morning but will move east of the area by mid to late morning. Additional showers and isolated thunderstorms will be possible across much of the area during the day as lift increases ahead of the approaching upper trough. Moisture will be limited, so precipitation is expected to be light, with most areas seeing one tenth inch or less of rainfall. It will be considerably cooler on Tuesday with highs well below normal for this time of year. NAM guidance looks too cool with highs in the upper 50s, so went with a GFS/NAM blend, which looks more reasonable with highs topping out in the lower 60s. Lingering showers will be possible Tuesday evening over southeast sections, otherwise dry conditions are expected overnight with clearing skies, as drier air filters in behind the departing upper trough. Temperatures will be very chilly Wednesday night with overnight lows in the lower and middle 40s. Dry and cool weather will continue on Wednesday with sunny skies, light winds and highs in the lower 70s. Another cool night is in store Wednesday night with low temperatures again in the 40s. Will maintain a dry forecast Thursday into next weekend with a warming trend through the period. Northwest flow aloft is expected through Saturday, with a short wave ridge overspreading the Plains on Sunday. High temperatures will warm from the mid 80s late week, to the upper 80s and lower 90s by the end of the weekend. Expect overnight lows in the 50s, warming into the 60s through the period. FIRE WEATHER... Elevated fire weather conditions will be possible across much of West Central Texas Wednesday through Friday, as minimum relative humidity values drop to 15 to 20 percent, but 20 foot winds generally remain below 15 mph. && .PRELIMINARY POINT TEMPS/POPS... Abilene 50 63 44 71 45 / 20 20 10 0 0 San Angelo 52 62 42 72 42 / 20 20 10 0 0 Junction 57 64 46 72 41 / 70 40 20 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ Aviation: Johnson
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1131 AM CDT MON MAY 12 2014 .UPDATE... The cold front is just a bit ahead of schedule, currently bifurcating the CWA from southwest to northeast (Ozona, to Paint Rock, to Cross Plains). Winds are from the north at 15-20 mph in the wake of this front. Temperatures remain in the 60s in areas that experienced the frontal passage early this morning, but have only regressed into the mid 70s at locations where the front as arrived in the past 1-2 hours. I lowered max temps across the Big Country and western Concho Valley a few degrees with only minor tweaks needed elsewhere. Other minor changes were made to the dewpoint/wind grids to account for the faster cold front. Convection is just now beginning to ramp up in the warm sector, primarily from Paint Rock to Brownwood. The EMC RAP meso-analysis provided by the SPC indicates MLCAPE values of 2000-3000 J/kg across the area with little/no CINH. Effective shear has increased over the past few hours and should be supportive of organized convection this afternoon and early this evening. Steep mid-level lapse rates will promote hail growth, however, the drier air behind this front may push the severe threat east of the area by early evening. During the late afternoon and evening hours, this convection should grow upscale, decreasing the severe threat and becoming more of a heavy rain producer. && .PREV DISCUSSION... /ISSUED 634 AM CDT MON MAY 12 2014/ AVIATION... /12Z TAFS/ Stratus will remain over the Heartland and Northwest Hill Country through mid morning and then will dissipate. Going with MVFR CIGS at the KJCT and KBBD terminals until 16Z. Mainly VFR conditions are expected the rest of the TAF forecast. Isolated to scattered thunderstorms will be possible east of an Abilene to San Angelo line mainly this afternoon and tonight. Storms may even be more numerous by tonight east of a Coleman to Junction line. The models are developing an MCS along a cold front by 06Z Tuesday and moving it slowly east into central Texas. However, confidence is only high enough to add VCTS to the terminals through 02Z Tuesday. Winds will be south and then become north as cold front moves through West Central Texas today and this evening. PREV DISCUSSION... /ISSUED 442 AM CDT MON MAY 12 2014/ SHORT TERM... (Today and Tonight) WV imagery this morning was showing and a strong upper level trough over the central and southern Rockies with a mid level speed max of 50 to 70 knots rotating out in the Plains. Upper level flow has backed to southwest over Texas. Also, a lot mid and upper subsidence evident which is still resulting in a strong cap over West Central Texas. At the surface, a cold front was located along a Quanah to Seminole line. A dryline extended south along a Wink to Sanderson line. Not much happening yet convection wise as low level inhibition and cap is still holding strong. A few showers have developed just behind the cold front across northwest Texas. The airmass was very moist across our area with southerly flow and dewpoints in the mid to upper 60s. For today, the chance of showers and thunderstorms will increase mid morning through the afternoon across mainly the eastern half of the CWFA. The cold front will continue southeast into West Central Texas and will probably slow its forward speed. Scattered showers and thunderstorms will develop along and behind the front as elevated instability erases the cap. The HRRR convective allowing model is showing best coverage of activity east of an Abilene to San Angelo line. The combination of good instability in the warm sector and weak 0-6KM shear of 25 to 30 knots will result in multicell storms with possible brief supercell structures. A few strong to severe storms are possible across mainly the Heartland and Northwest Hill Country. The main hazards will be large hail, damaging winds and dangerous cloud to ground lightning. Going with mainly chance to slight chance POPS for today. Temperatures will be cooler with highs in the 80s. For tonight, There will be a chance of showers thunderstorms across much of our area with better coverage of storms east of a Coleman to Sonora line. a few storms may be severe. The main hazards will be large hail, damaging winds and dangerous cloud to ground lightning mainly before 06Z Tuesday. The bigger focus will be the potential for locally heavy rainfall across the Heartland and Northwest Hill Country, due to good low level southerly flow. moisture flux convergence along a slow moving cold front, PWAT values of 1.5 to 1.75 inches and in the RRQ of highly amplified 250MB jet. Rainfall amounts of 1 to 2 inches with locally heavy amounts are possible along and east of a Brownwood to Junction line. Also, going with LKLY to CAT POPS across the southeast CWFA. LONG TERM... (Tuesday through next Monday) The cold front will be well south of the area early Tuesday morning, with the upper level trough axis over New Mexico. Showers and thunderstorms may be ongoing across far southeast sections early Tuesday morning but will move east of the area by mid to late morning. Additional showers and isolated thunderstorms will be possible across much of the area during the day as lift increases ahead of the approaching upper trough. Moisture will be limited, so precipitation is expected to be light, with most areas seeing one tenth inch or less of rainfall. It will be considerably cooler on Tuesday with highs well below normal for this time of year. NAM guidance looks too cool with highs in the upper 50s, so went with a GFS/NAM blend, which looks more reasonable with highs topping out in the lower 60s. Lingering showers will be possible Tuesday evening over southeast sections, otherwise dry conditions are expected overnight with clearing skies, as drier air filters in behind the departing upper trough. Temperatures will be very chilly Wednesday night with overnight lows in the lower and middle 40s. Dry and cool weather will continue on Wednesday with sunny skies, light winds and highs in the lower 70s. Another cool night is in store Wednesday night with low temperatures again in the 40s. Will maintain a dry forecast Thursday into next weekend with a warming trend through the period. Northwest flow aloft is expected through Saturday, with a short wave ridge overspreading the Plains on Sunday. High temperatures will warm from the mid 80s late week, to the upper 80s and lower 90s by the end of the weekend. Expect overnight lows in the 50s, warming into the 60s through the period. FIRE WEATHER... Elevated fire weather conditions will be possible across much of West Central Texas Wednesday through Friday, as minimum relative humidity values drop to 15 to 20 percent, but 20 foot winds generally remain below 15 mph. && .PRELIMINARY POINT TEMPS/POPS... Abilene 76 50 63 45 72 / 40 20 20 10 0 San Angelo 85 52 62 43 73 / 20 20 20 10 0 Junction 84 57 64 46 73 / 30 70 40 20 0 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ Update: Johnson
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1039 AM CDT MON MAY 12 2014 .UPDATE... CURRENT FORECAST IS IN GOOD SHAPE AND HAVE ONLY MADE SOME COSMETIC CHANGES TO THE HOURLY DATA AND MORNING POPS. LATEST SURFACE ANALYSIS INDICATES THAT THE COLD FRONT IS LOCATED ALONG A LINE ACROSS CENTRAL OKLAHOMA INTO NORTHWEST TEXAS BETWEEN BOWIE AND WICHITA FALLS SOUTHWARD TO BRECKENRIDGE. AHEAD OF THE COLD FRONT AN AREA OF SHOWERS AND THUNDERSTORMS INITIATED ON WHAT APPEARS TO BE AN INITIAL WAVE OF FORCING OR A SOUTHWARD PROPAGATING GRAVITY WAVE. EITHER WAY...AMDAR SOUNDING DATA FROM DFW AIRCRAFT INDICATE THAT STRONG CAPPING INVERSION NOTED ON 12Z FWD SOUNDING WAS ALL BUT COMPLETELY ERODED IN ABOUT 45 MINUTES. THIS INITIAL WAVE OF ACTIVITY HAS FAILED TO ORGANIZE OR REALLY TAKE OFF IN INTENSITY WHICH HAS LEFT THE LOW LEVEL WINDS AND MOISTURE IN PLACE BEHIND IT. THIS WILL LIKELY HELP TO INITIATE MORE ROBUST THUNDERSTORM ACTIVITY OVER THE NEXT FEW HOURS AS THE FRONT CONTINUES TO MOVE SOUTH. LATEST OBJECTIVE ANALYSIS ACROSS NORTH TEXAS SHOWS AROUND 2000 J/KG OF SURFACE BASED INSTABILITY SOUTH/EAST OF THE FRONT WHERE THE SUN HAS COME OUT A BIT WITH LITTLE INHIBITION LEFT. EXPECT THUNDERSTORMS TO BECOME MORE NUMEROUS IN COVERAGE THROUGH EARLY AFTERNOON. THE SEVERE THREAT REMAINS ACROSS NORTH TEXAS...ESPECIALLY GIVEN THE STRONG INSTABILITY...HOWEVER DEEP LAYER SHEAR ISNT ALL THAT STRONG SO MULTICELL CLUSTERS ARE EXPECTED. SOME SEVERE WIND GUSTS WOULD BE POSSIBLE ALONG WITH SEVERE HAIL. THE MORE SIGNIFICANT THREAT WILL BE FOR VERY HEAVY RAINFALL AND FLASH FLOODING...ESPECIALLY ACROSS THE EASTERN COUNTIES WHERE THE FRONT IS EXPECTED TO SLOWLY MOVE THROUGH TONIGHT. SOME AREAS COULD PICK UP IN EXCESS OF 3 INCHES OF RAIN IN A SHORT PERIOD OF TIME WITH ADDITIONAL RAINFALL PERSISTING INTO TONIGHT. DUNN && .AVIATION... CONCERNS...TIMING OF CONVECTION AND WIND SHIFT. ...WIDESPREAD DISRUPTIONS ARE EXPECTED THIS AFTERNOON AT DFW AIRPORT AND DALLAS LOVE FIELD... A COLD FRONT IS STEADILY APPROACHING FROM THE NORTHWEST. ALTHOUGH FRONTS TEND TO SLOW DOWN DURING THE DAYLIGHT HOURS...THE MOTION OF THE BOUNDARY TODAY WILL BE ENHANCED BY CONVECTION. SHOWERS AND THUNDERSTORMS HAVE ALREADY REDEVELOPED ALONG THE BOUNDARY DURING THE PREDAWN HOURS...AND ADDITIONAL ACTIVITY MAY DEVELOP WELL IN ADVANCE OF THE WIND SHIFT THIS MORNING. THIS ACTIVITY WILL PRIMARILY IMPACT NORTHWEST ARRIVALS THIS MORNING...BUT SOME SHOWERS OR STORMS COULD OCCUR NEAR METROPLEX AIRPORTS BEFORE MIDDAY. THE BULK OF THE THUNDERSTORM ACTIVITY IN THE IMMEDIATE METROPLEX WILL BE DURING THE AFTERNOON HOURS...WHEN A LINE OF STORMS MOVES SLOWLY THROUGH. WINDS MAY BE CHAOTIC WITH THE ACTIVITY...BUT NORTHWEST WINDS SHOULD PREVAIL BY MID-AFTERNOON. ALTHOUGH SOME STRONG OR MARGINALLY SEVERE STORMS WILL BE POSSIBLE WITHIN THE LINE...THE MAIN IMPACTS TO COMMERCIAL AVIATION TODAY WILL BE FROM LIGHTNING. SIMILAR IMPACTS ARE EXPECTED AT CENTRAL TEXAS AIRPORTS...BUT THE ACTIVITY AND WIND SHIFT WILL LIKELY OCCUR A FEW HOURS LATER THAN IN THE METROPLEX. THE FRONTAL PASSAGE WILL NOT BRING AN END TO THE PRECIPITATION... AND RAIN WILL CONTINUE MUCH OF THE EVENING. THE 850MB FRONT MAY BE AS MUCH AS 12 HOURS BEHIND THE SURFACE BOUNDARY...AND BUOYANT GULF AIR WILL MAINTAIN INSTABILITY ABOVE THE FRONTAL LAYER SUFFICIENT FOR THUNDER. HOWEVER...THE THUNDER THIS EVENING AND OVERNIGHT IS EXPECTED TO BE ISOLATED. TO REDUCE THE NUMBER OF HOURS WITH THUNDER IN THE TAFS...WILL CARRY PREVAILING RAIN WITHOUT THUNDER. 25 && .PREV DISCUSSION... /ISSUED 437 AM CDT MON MAY 12 2014/ THE POTENT UPPER LEVEL LOW OVER THE FOUR CORNERS THAT WAS RESPONSIBLE FOR SNOW IN DENVER YESTERDAY WILL EJECT NORTHEAST OUT INTO THE PLAINS TODAY...BUT ADDITIONAL UPPER ENERGY WILL DROP INTO THE BASE OF A DEEPENING LONGWAVE TROUGH TODAY. THIS UPPER TROUGH WILL ENGULF THE CENTRAL US BY TOMORROW...A PATTERN THAT IS VERY UNUSUAL FOR MID MAY. THIS SYSTEM HAS TAPPED INTO A CANADIAN AIRMASS AND HAS SENT AN UNSEASONABLY STRONG COLD FRONT BARRELING SOUTH. AT 4AM...THIS FRONT WAS LOCATED JUST SOUTH OF LUBBOCK TO NEAR VERNON TO EL RENO OKLAHOMA AND WAS MOVING SOUTHEAST AT 15 TO 20MPH. THE FRONT IS AHEAD OF MOST MODEL PROJECTIONS...WHICH IS NOT SURPRISING GIVEN THE COLD AIR BEHIND IT. THE RAP HAS A GOOD HANDLE ON THE FRONT/S SPEED AND IT WILL BE USED FOR TIMING. THE FRONT WILL ARRIVE INTO THE NORTHWEST CWA BY MID-MORNING AND CONTINUE TO TRACK SOUTHEAST...BUT SLOW DOWN A BIT DUE TO DAYTIME HEATING. THE FRONT SHOULD REACH A SHERMAN TO DFW TO COMANCHE LINE BY MID-AFTERNOON. THE AIRMASS AHEAD OF THE FRONT WILL BE WARM AND MOIST...WITH SEVERAL DAYS OF SOUTHERLY FLOW NOW BRINGING PRECIPITABLE WATER VALUES UP TO 1.75 TO 2 INCHES. SURFACE BASED CAPE WILL PEAK AROUND 2000-2500 J/KG THIS AFTERNOON AS TEMPS WARM INTO THE MID 80S. DAYTIME HEATING AND FORCING FOR ASCENT FROM THE UPPER LEVEL TROUGH WILL LIFT/ERODE THE WEAK CAPPING INVERSION...AND THUS CONVECTION WILL INCREASE IN COVERAGE ALONG THE FRONT BY LATE MORNING. BULK LAYER SHEAR IS FAIRLY WEAK...ON THE ORDER OF 25KT...SO MULTICELLULAR CONVECTIVE MODES ARE EXPECTED. GIVEN THE HIGH INSTABILITY AND WEAK SHEAR...SOME SEVERE WIND/HAIL REPORTS ARE POSSIBLE TODAY WITH THE STRONGEST STORMS. CONVECTION ALONG THE FRONT WILL LIKELY CONGEAL INTO A SOLID LINE OF THUNDERSTORMS BY MID-AFTERNOON...WITH THE LINE CONTINUING TO GROW UPSCALE INTO A FORMIDABLE LINEAR MCS BY THE EVENING HOURS. MCS PROPAGATION VECTORS AND DIFFLUENT THICKNESS FIELDS ALOFT SUGGEST THAT THE MOVEMENT OF THIS SYSTEM WILL REMAIN FAIRLY SLOW...LIKELY LESS THAN 10-15MPH. THIS FORWARD SPEED SHOULD IN THEORY LIMIT THE DAMAGING WIND THREAT THIS EVENING OVER THE SOUTHEAST HALF OF THE CWA...BUT WILL RESULT IN ENHANCED RAINFALL TOTALS. THE MCS WILL LIKELY HAVE SLOWER WEST TO EAST MOVEMENT THAN NORTH TO SOUTH...AND THUS THE ORIENTATION OF THE LINE SUGGESTS THAT EASTERN ZONES WILL HAVE A GREATER RISK FOR PROLONGED HEAVY RAINFALL. EXPECT THE LINE TO PUSH THROUGH THE SOUTHWEST ZONES FAIRLY QUICKLY...LIKELY REACHING A LAMPASAS TO WACO LINE BY 6 PM. A TIGHT RAINFALL GRADIENT IS FORECAST OVER THE CWA WITH LESS THAN A HALF INCH EXPECTED OVER THE NW ZONES...TO 1-2 INCHES IN A BAND FROM THE SHERMAN AREA TO THE METROPLEX TO COMANCHE...AND 2-3 INCHES SOUTH AND EAST OF A PARIS TO GREENVILLE TO HILLSBORO LINE. THIS LATTER REGION WAS THE SAME AREA THAT RECEIVED A SWATH OF 2-4 INCHES OF RAIN THURSDAY AND SOILS ARE ALREADY SATURATED. THUS A FLASH FLOOD WATCH WAS ISSUED FOR LOCATIONS ALONG AND SOUTHEAST OF A BONHAM TO DALLAS TO TEMPLE LINE. WHILE WE DONT EXPECT MOST OF DALLAS AND COLLIN COUNTIES TO RECEIVE MORE THAN 2 INCHES...GIVEN THE URBAN DEVELOPMENT THERE AND THE FACT THAT THE SOUTHEAST PARTS OF THESE COUNTIES DID SEE OVER 4 INCHES...FELT IT WAS BEST TO INCLUDE THEM. FARTHER SOUTH...FROM WACO TO ATHENS...LESS RAIN FELL IN THIS AREA LAST THURSDAY...BUT QUICK TOTALS OF 2-3 INCHES ARE POSSIBLE THIS EVENING. FOR WACO/TEMPLE/KILLEEN ONLY AROUND 2 INCHES ARE FORECAST...BUT AGAIN URBAN INFRASTRUCTURE MAY EXACERBATE ANY FLOODING...SO THEY WERE INCLUDED IN THE WATCH TOO. BECAUSE THE UPPER LEVEL TROUGH WILL BE SLOW TO MOVE EAST...CONTINUED SOUTHERLY FLOW ALOFT BEHIND THE FRONT/LINE OF STORMS WILL OCCUR THIS EVENING. THUS THE LINE OF STORMS WILL LIKELY BE SUCCEEDED BY A FEW HOURS OF STEADY LIGHT TO MODERATE STRATIFORM RAINS...ESPECIALLY ACROSS THE WATCH AREA. THIS ACTIVITY SHOULD END FROM NORTHWEST TO SOUTHEAST LATE TONIGHT...BUT MAY LINGER OVER THE SOUTHEAST ZONES INTO TUESDAY MORNING. TUESDAY SHOULD BE DRY FOR THE REMAINDER OF THE AREA WITH MOSTLY CLOUDY AND COOL CONDITIONS AS COOLER AIR POURS INTO THE REGION BEHIND THE FRONT. FORECAST HIGH TEMPS MAY BE TOO WARM...BUT IT WOULD ONLY TAKE AN HOUR OR TWO OF AFTERNOON MAY SUNSHINE TO WARM US INTO THE MID 60S...SO STAYED CONSERVATIVE THERE. THE STRONGEST UPPER LEVEL FORCING WILL CROSS THE REGION TUESDAY EVENING BUT THE AIRMASS WILL BE PRETTY WORKED OVER. HOWEVER THIS FORCING SHOULD RESULT IN SCATTERED ELEVATED SHOWERS AND A FEW STORMS OVER THE REGION AND SHOULD SQUEEZE OUT ANOTHER TENTH TO QUARTER INCH OF RAINFALL. HAVE BUMPED POPS UP TUESDAY NIGHT AS MODEL GUIDANCE HAS COME INTO BETTER AGREEMENT ON THIS ROUND. OTHERWISE THE REMAINDER OF THE FORECAST LOOKS QUIET AND VERY NICE FOR MID TO LATE MAY. DRY NORTHWESTERLY FLOW ALOFT WILL PREVAIL THROUGH THE WEEKEND LEADING TO CLEAR SKIES AND LIGHT WINDS. GOOD RADIATIONAL COOLING WEDNESDAY NIGHT WILL SEND LOW TEMPS DOWN INTO THE 40S AREA WIDE...AND WACO MAY BREAK ITS RECORD LOW OF 46. HIGHS IN THE UPPER 60S ARE EXPECTED THURSDAY...BUT TEMPS SHOULD WARM INTO THE 70S FRIDAY AND THE 80S BY THE WEEKEND. DRY WEATHER WILL CONTINUE INTO NEXT WEEK WITH TEMPS WARMING TO ABOVE NORMAL. TR.92 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 83 54 66 51 68 / 90 80 20 40 10 WACO, TX 87 57 65 51 69 / 70 100 40 60 10 PARIS, TX 84 56 63 51 64 / 70 90 20 50 20 DENTON, TX 80 52 65 49 68 / 80 70 20 40 10 MCKINNEY, TX 83 53 64 50 68 / 90 80 20 40 10 DALLAS, TX 84 55 65 52 68 / 90 80 20 50 10 TERRELL, TX 85 57 64 51 67 / 70 90 20 50 20 CORSICANA, TX 86 59 64 52 67 / 60 100 40 60 20 TEMPLE, TX 87 58 64 52 69 / 50 100 50 60 10 MINERAL WELLS, TX 80 50 66 47 71 / 70 60 20 30 10 && .FWD WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 4 PM CDT THIS AFTERNOON THROUGH LATE TONIGHT FOR TXZ094-095-104>107-119>123-134-135-145>148-158>162- 174-175. && $$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
634 AM CDT MON MAY 12 2014 .AVIATION... /12Z TAFS/ Stratus will remain over the Heartland and Northwest Hill Country through mid morning and then will dissipate. Going with MVFR CIGS at the KJCT and KBBD terminals until 16Z. Mainly VFR conditions are expected the rest of the TAF forecast. Isolated to scattered thunderstorms will be possible east of an Abilene to San Angelo line mainly this afternoon and tonight. Storms may even be more numerous by tonight east of a Coleman to Junction line. The models are developing an MCS along a cold front by 06Z Tuesday and moving it slowly east into central Texas. However, confidence is only high enough to add VCTS to the terminals through 02Z Tuesday. Winds will be south and then become north as cold front moves through West Central Texas today and this evening. && .PREV DISCUSSION... /ISSUED 442 AM CDT MON MAY 12 2014/ SHORT TERM... (Today and Tonight) WV imagery this morning was showing and a strong upper level trough over the central and southern Rockies with a mid level speed max of 50 to 70 knots rotating out in the Plains. Upper level flow has backed to southwest over Texas. Also, a lot mid and upper subsidence evident which is still resulting in a strong cap over West Central Texas. At the surface, a cold front was located along a Quanah to Seminole line. A dryline extended south along a Wink to Sanderson line. Not much happening yet convection wise as low level inhibition and cap is still holding strong. A few showers have developed just behind the cold front across northwest Texas. The airmass was very moist across our area with southerly flow and dewpoints in the mid to upper 60s. For today, the chance of showers and thunderstorms will increase mid morning through the afternoon across mainly the eastern half of the CWFA. The cold front will continue southeast into West Central Texas and will probably slow its forward speed. Scattered showers and thunderstorms will develop along and behind the front as elevated instability erases the cap. The HRRR convective allowing model is showing best coverage of activity east of an Abilene to San Angelo line. The combination of good instability in the warm sector and weak 0-6KM shear of 25 to 30 knots will result in multicell storms with possible brief supercell structures. A few strong to severe storms are possible across mainly the Heartland and Northwest Hill Country. The main hazards will be large hail, damaging winds and dangerous cloud to ground lightning. Going with mainly chance to slight chance POPS for today. Temperatures will be cooler with highs in the 80s. For tonight, There will be a chance of showers thunderstorms across much of our area with better coverage of storms east of a Coleman to Sonora line. a few storms may be severe. The main hazards will be large hail, damaging winds and dangerous cloud to ground lightning mainly before 06Z Tuesday. The bigger focus will be the potential for locally heavy rainfall across the Heartland and Northwest Hill Country, due to good low level southerly flow. moisture flux convergence along a slow moving cold front, PWAT values of 1.5 to 1.75 inches and in the RRQ of highly amplified 250MB jet. Rainfall amounts of 1 to 2 inches with locally heavy amounts are possible along and east of a Brownwood to Junction line. Also, going with LKLY to CAT POPS across the southeast CWFA. LONG TERM... (Tuesday through next Monday) The cold front will be well south of the area early Tuesday morning, with the upper level trough axis over New Mexico. Showers and thunderstorms may be ongoing across far southeast sections early Tuesday morning but will move east of the area by mid to late morning. Additional showers and isolated thunderstorms will be possible across much of the area during the day as lift increases ahead of the approaching upper trough. Moisture will be limited, so precipitation is expected to be light, with most areas seeing one tenth inch or less of rainfall. It will be considerably cooler on Tuesday with highs well below normal for this time of year. NAM guidance looks too cool with highs in the upper 50s, so went with a GFS/NAM blend, which looks more reasonable with highs topping out in the lower 60s. Lingering showers will be possible Tuesday evening over southeast sections, otherwise dry conditions are expected overnight with clearing skies, as drier air filters in behind the departing upper trough. Temperatures will be very chilly Wednesday night with overnight lows in the lower and middle 40s. Dry and cool weather will continue on Wednesday with sunny skies, light winds and highs in the lower 70s. Another cool night is in store Wednesday night with low temperatures again in the 40s. Will maintain a dry forecast Thursday into next weekend with a warming trend through the period. Northwest flow aloft is expected through Saturday, with a short wave ridge overspreading the Plains on Sunday. High temperatures will warm from the mid 80s late week, to the upper 80s and lower 90s by the end of the weekend. Expect overnight lows in the 50s, warming into the 60s through the period. FIRE WEATHER... Elevated fire weather conditions will be possible across much of West Central Texas Wednesday through Friday, as minimum relative humidity values drop to 15 to 20 percent, but 20 foot winds generally remain below 15 mph. && .PRELIMINARY POINT TEMPS/POPS... Abilene 80 50 63 45 72 / 40 20 20 10 0 San Angelo 86 52 62 43 73 / 30 20 20 10 0 Junction 85 57 64 46 73 / 50 70 40 20 0 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21/24
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
608 AM CDT MON MAY 12 2014 .AVIATION... CONCERNS...TIMING OF CONVECTION AND WIND SHIFT. ...WIDESPREAD DISRUPTIONS ARE EXPECTED THIS AFTERNOON AT DFW AIRPORT AND DALLAS LOVE FIELD... A COLD FRONT IS STEADILY APPROACHING FROM THE NORTHWEST. ALTHOUGH FRONTS TEND TO SLOW DOWN DURING THE DAYLIGHT HOURS...THE MOTION OF THE BOUNDARY TODAY WILL BE ENHANCED BY CONVECTION. SHOWERS AND THUNDERSTORMS HAVE ALREADY REDEVELOPED ALONG THE BOUNDARY DURING THE PREDAWN HOURS...AND ADDITIONAL ACTIVITY MAY DEVELOP WELL IN ADVANCE OF THE WIND SHIFT THIS MORNING. THIS ACTIVITY WILL PRIMARILY IMPACT NORTHWEST ARRIVALS THIS MORNING...BUT SOME SHOWERS OR STORMS COULD OCCUR NEAR METROPLEX AIRPORTS BEFORE MIDDAY. THE BULK OF THE THUNDERSTORM ACTIVITY IN THE IMMEDIATE METROPLEX WILL BE DURING THE AFTERNOON HOURS...WHEN A LINE OF STORMS MOVES SLOWLY THROUGH. WINDS MAY BE CHAOTIC WITH THE ACTIVITY...BUT NORTHWEST WINDS SHOULD PREVAIL BY MID-AFTERNOON. ALTHOUGH SOME STRONG OR MARGINALLY SEVERE STORMS WILL BE POSSIBLE WITHIN THE LINE...THE MAIN IMPACTS TO COMMERCIAL AVIATION TODAY WILL BE FROM LIGHTNING. SIMILAR IMPACTS ARE EXPECTED AT CENTRAL TEXAS AIRPORTS...BUT THE ACTIVITY AND WIND SHIFT WILL LIKELY OCCUR A FEW HOURS LATER THAN IN THE METROPLEX. THE FRONTAL PASSAGE WILL NOT BRING AN END TO THE PRECIPITATION... AND RAIN WILL CONTINUE MUCH OF THE EVENING. THE 850MB FRONT MAY BE AS MUCH AS 12 HOURS BEHIND THE SURFACE BOUNDARY...AND BUOYANT GULF AIR WILL MAINTAIN INSTABILITY ABOVE THE FRONTAL LAYER SUFFICIENT FOR THUNDER. HOWEVER...THE THUNDER THIS EVENING AND OVERNIGHT IS EXPECTED TO BE ISOLATED. TO REDUCE THE NUMBER OF HOURS WITH THUNDER IN THE TAFS...WILL CARRY PREVAILING RAIN WITHOUT THUNDER. 25 && .PREV DISCUSSION... /ISSUED 437 AM CDT MON MAY 12 2014/ THE POTENT UPPER LEVEL LOW OVER THE FOUR CORNERS THAT WAS RESPONSIBLE FOR SNOW IN DENVER YESTERDAY WILL EJECT NORTHEAST OUT INTO THE PLAINS TODAY...BUT ADDITIONAL UPPER ENERGY WILL DROP INTO THE BASE OF A DEEPENING LONGWAVE TROUGH TODAY. THIS UPPER TROUGH WILL ENGULF THE CENTRAL US BY TOMORROW...A PATTERN THAT IS VERY UNUSUAL FOR MID MAY. THIS SYSTEM HAS TAPPED INTO A CANADIAN AIRMASS AND HAS SENT AN UNSEASONABLY STRONG COLD FRONT BARRELING SOUTH. AT 4AM...THIS FRONT WAS LOCATED JUST SOUTH OF LUBBOCK TO NEAR VERNON TO EL RENO OKLAHOMA AND WAS MOVING SOUTHEAST AT 15 TO 20MPH. THE FRONT IS AHEAD OF MOST MODEL PROJECTIONS...WHICH IS NOT SURPRISING GIVEN THE COLD AIR BEHIND IT. THE RAP HAS A GOOD HANDLE ON THE FRONT/S SPEED AND IT WILL BE USED FOR TIMING. THE FRONT WILL ARRIVE INTO THE NORTHWEST CWA BY MID-MORNING AND CONTINUE TO TRACK SOUTHEAST...BUT SLOW DOWN A BIT DUE TO DAYTIME HEATING. THE FRONT SHOULD REACH A SHERMAN TO DFW TO COMANCHE LINE BY MID-AFTERNOON. THE AIRMASS AHEAD OF THE FRONT WILL BE WARM AND MOIST...WITH SEVERAL DAYS OF SOUTHERLY FLOW NOW BRINGING PRECIPITABLE WATER VALUES UP TO 1.75 TO 2 INCHES. SURFACE BASED CAPE WILL PEAK AROUND 2000-2500 J/KG THIS AFTERNOON AS TEMPS WARM INTO THE MID 80S. DAYTIME HEATING AND FORCING FOR ASCENT FROM THE UPPER LEVEL TROUGH WILL LIFT/ERODE THE WEAK CAPPING INVERSION...AND THUS CONVECTION WILL INCREASE IN COVERAGE ALONG THE FRONT BY LATE MORNING. BULK LAYER SHEAR IS FAIRLY WEAK...ON THE ORDER OF 25KT...SO MULTICELLULAR CONVECTIVE MODES ARE EXPECTED. GIVEN THE HIGH INSTABILITY AND WEAK SHEAR...SOME SEVERE WIND/HAIL REPORTS ARE POSSIBLE TODAY WITH THE STRONGEST STORMS. CONVECTION ALONG THE FRONT WILL LIKELY CONGEAL INTO A SOLID LINE OF THUNDERSTORMS BY MID-AFTERNOON...WITH THE LINE CONTINUING TO GROW UPSCALE INTO A FORMIDABLE LINEAR MCS BY THE EVENING HOURS. MCS PROPAGATION VECTORS AND DIFFLUENT THICKNESS FIELDS ALOFT SUGGEST THAT THE MOVEMENT OF THIS SYSTEM WILL REMAIN FAIRLY SLOW...LIKELY LESS THAN 10-15MPH. THIS FORWARD SPEED SHOULD IN THEORY LIMIT THE DAMAGING WIND THREAT THIS EVENING OVER THE SOUTHEAST HALF OF THE CWA...BUT WILL RESULT IN ENHANCED RAINFALL TOTALS. THE MCS WILL LIKELY HAVE SLOWER WEST TO EAST MOVEMENT THAN NORTH TO SOUTH...AND THUS THE ORIENTATION OF THE LINE SUGGESTS THAT EASTERN ZONES WILL HAVE A GREATER RISK FOR PROLONGED HEAVY RAINFALL. EXPECT THE LINE TO PUSH THROUGH THE SOUTHWEST ZONES FAIRLY QUICKLY...LIKELY REACHING A LAMPASAS TO WACO LINE BY 6 PM. A TIGHT RAINFALL GRADIENT IS FORECAST OVER THE CWA WITH LESS THAN A HALF INCH EXPECTED OVER THE NW ZONES...TO 1-2 INCHES IN A BAND FROM THE SHERMAN AREA TO THE METROPLEX TO COMANCHE...AND 2-3 INCHES SOUTH AND EAST OF A PARIS TO GREENVILLE TO HILLSBORO LINE. THIS LATTER REGION WAS THE SAME AREA THAT RECEIVED A SWATH OF 2-4 INCHES OF RAIN THURSDAY AND SOILS ARE ALREADY SATURATED. THUS A FLASH FLOOD WATCH WAS ISSUED FOR LOCATIONS ALONG AND SOUTHEAST OF A BONHAM TO DALLAS TO TEMPLE LINE. WHILE WE DONT EXPECT MOST OF DALLAS AND COLLIN COUNTIES TO RECEIVE MORE THAN 2 INCHES...GIVEN THE URBAN DEVELOPMENT THERE AND THE FACT THAT THE SOUTHEAST PARTS OF THESE COUNTIES DID SEE OVER 4 INCHES...FELT IT WAS BEST TO INCLUDE THEM. FARTHER SOUTH...FROM WACO TO ATHENS...LESS RAIN FELL IN THIS AREA LAST THURSDAY...BUT QUICK TOTALS OF 2-3 INCHES ARE POSSIBLE THIS EVENING. FOR WACO/TEMPLE/KILLEEN ONLY AROUND 2 INCHES ARE FORECAST...BUT AGAIN URBAN INFRASTRUCTURE MAY EXACERBATE ANY FLOODING...SO THEY WERE INCLUDED IN THE WATCH TOO. BECAUSE THE UPPER LEVEL TROUGH WILL BE SLOW TO MOVE EAST...CONTINUED SOUTHERLY FLOW ALOFT BEHIND THE FRONT/LINE OF STORMS WILL OCCUR THIS EVENING. THUS THE LINE OF STORMS WILL LIKELY BE SUCCEEDED BY A FEW HOURS OF STEADY LIGHT TO MODERATE STRATIFORM RAINS...ESPECIALLY ACROSS THE WATCH AREA. THIS ACTIVITY SHOULD END FROM NORTHWEST TO SOUTHEAST LATE TONIGHT...BUT MAY LINGER OVER THE SOUTHEAST ZONES INTO TUESDAY MORNING. TUESDAY SHOULD BE DRY FOR THE REMAINDER OF THE AREA WITH MOSTLY CLOUDY AND COOL CONDITIONS AS COOLER AIR POURS INTO THE REGION BEHIND THE FRONT. FORECAST HIGH TEMPS MAY BE TOO WARM...BUT IT WOULD ONLY TAKE AN HOUR OR TWO OF AFTERNOON MAY SUNSHINE TO WARM US INTO THE MID 60S...SO STAYED CONSERVATIVE THERE. THE STRONGEST UPPER LEVEL FORCING WILL CROSS THE REGION TUESDAY EVENING BUT THE AIRMASS WILL BE PRETTY WORKED OVER. HOWEVER THIS FORCING SHOULD RESULT IN SCATTERED ELEVATED SHOWERS AND A FEW STORMS OVER THE REGION AND SHOULD SQUEEZE OUT ANOTHER TENTH TO QUARTER INCH OF RAINFALL. HAVE BUMPED POPS UP TUESDAY NIGHT AS MODEL GUIDANCE HAS COME INTO BETTER AGREEMENT ON THIS ROUND. OTHERWISE THE REMAINDER OF THE FORECAST LOOKS QUIET AND VERY NICE FOR MID TO LATE MAY. DRY NORTHWESTERLY FLOW ALOFT WILL PREVAIL THROUGH THE WEEKEND LEADING TO CLEAR SKIES AND LIGHT WINDS. GOOD RADIATIONAL COOLING WEDNESDAY NIGHT WILL SEND LOW TEMPS DOWN INTO THE 40S AREA WIDE...AND WACO MAY BREAK ITS RECORD LOW OF 46. HIGHS IN THE UPPER 60S ARE EXPECTED THURSDAY...BUT TEMPS SHOULD WARM INTO THE 70S FRIDAY AND THE 80S BY THE WEEKEND. DRY WEATHER WILL CONTINUE INTO NEXT WEEK WITH TEMPS WARMING TO ABOVE NORMAL. TR.92 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 83 54 66 51 68 / 90 80 20 40 10 WACO, TX 87 57 65 51 69 / 70 100 40 60 10 PARIS, TX 84 56 63 51 64 / 70 90 20 50 20 DENTON, TX 80 52 65 49 68 / 80 70 20 40 10 MCKINNEY, TX 83 53 64 50 68 / 90 80 20 40 10 DALLAS, TX 84 55 65 52 68 / 90 80 20 50 10 TERRELL, TX 85 57 64 51 67 / 70 90 20 50 20 CORSICANA, TX 86 59 64 52 67 / 60 100 40 60 20 TEMPLE, TX 87 58 64 52 69 / 50 100 50 60 10 MINERAL WELLS, TX 79 50 66 47 71 / 70 60 20 30 10 && .FWD WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 4 PM CDT THIS AFTERNOON THROUGH LATE TONIGHT FOR TXZ094-095-104>107-119>123-134-135-145>148-158>162- 174-175. && $$ 25/92
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
442 AM CDT MON MAY 12 2014 .SHORT TERM... (Today and Tonight) WV imagery this morning was showing and a strong upper level trough over the central and southern Rockies with a mid level speed max of 50 to 70 knots rotating out in the Plains. Upper level flow has backed to southwest over Texas. Also, a lot mid and upper subsidence evident which is still resulting in a strong cap over West Central Texas. At the surface, a cold front was located along a Quanah to Seminole line. A dryline extended south along a Wink to Sanderson line. Not much happening yet convection wise as low level inhibition and cap is still holding strong. A few showers have developed just behind the cold front across northwest Texas. The airmass was very moist across our area with southerly flow and dewpoints in the mid to upper 60s. For today, the chance of showers and thunderstorms will increase mid morning through the afternoon across mainly the eastern half of the CWFA. The cold front will continue southeast into West Central Texas and will probably slow its forward speed. Scattered showers and thunderstorms will develop along and behind the front as elevated instability erases the cap. The HRRR convective allowing model is showing best coverage of activity east of an Abilene to San Angelo line. The combination of good instability in the warm sector and weak 0-6KM shear of 25 to 30 knots will result in multicell storms with possible brief supercell structures. A few strong to severe storms are possible across mainly the Heartland and Northwest Hill Country. The main hazards will be large hail, damaging winds and dangerous cloud to ground lightning. Going with mainly chance to slight chance POPS for today. Temperatures will be cooler with highs in the 80s. For tonight, There will be a chance of showers thunderstorms across much of our area with better coverage of storms east of a Coleman to Sonora line. a few storms may be severe. The main hazards will be large hail, damaging winds and dangerous cloud to ground lightning mainly before 06Z Tuesday. The bigger focus will be the potential for locally heavy rainfall across the Heartland and Northwest Hill Country, due to good low level southerly flow. moisture flux convergence along a slow moving cold front, PWAT values of 1.5 to 1.75 inches and in the RRQ of highly amplified 250MB jet. Rainfall amounts of 1 to 2 inches with locally heavy amounts are possible along and east of a Brownwood to Junction line. Also, going with LKLY to CAT POPS across the southeast CWFA. .LONG TERM... (Tuesday through next Monday) The cold front will be well south of the area early Tuesday morning, with the upper level trough axis over New Mexico. Showers and thunderstorms may be ongoing across far southeast sections early Tuesday morning but will move east of the area by mid to late morning. Additional showers and isolated thunderstorms will be possible across much of the area during the day as lift increases ahead of the approaching upper trough. Moisture will be limited, so precipitation is expected to be light, with most areas seeing one tenth inch or less of rainfall. It will be considerably cooler on Tuesday with highs well below normal for this time of year. NAM guidance looks too cool with highs in the upper 50s, so went with a GFS/NAM blend, which looks more reasonable with highs topping out in the lower 60s. Lingering showers will be possible Tuesday evening over southeast sections, otherwise dry conditions are expected overnight with clearing skies, as drier air filters in behind the departing upper trough. Temperatures will be very chilly Wednesday night with overnight lows in the lower and middle 40s. Dry and cool weather will continue on Wednesday with sunny skies, light winds and highs in the lower 70s. Another cool night is in store Wednesday night with low temperatures again in the 40s. Will maintain a dry forecast Thursday into next weekend with a warming trend through the period. Northwest flow aloft is expected through Saturday, with a short wave ridge overspreading the Plains on Sunday. High temperatures will warm from the mid 80s late week, to the upper 80s and lower 90s by the end of the weekend. Expect overnight lows in the 50s, warming into the 60s through the period. && .FIRE WEATHER... Elevated fire weather conditions will be possible across much of West Central Texas Wednesday through Friday, as minimum relative humidity values drop to 15 to 20 percent, but 20 foot winds generally remain below 15 mph. && .PRELIMINARY POINT TEMPS/POPS... Abilene 80 50 63 45 72 / 40 20 20 10 0 San Angelo 86 52 62 43 73 / 30 20 20 10 0 Junction 85 57 64 46 73 / 50 70 40 20 0 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21/24
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
437 AM CDT MON MAY 12 2014 .DISCUSSION... THE POTENT UPPER LEVEL LOW OVER THE FOUR CORNERS THAT WAS RESPONSIBLE FOR SNOW IN DENVER YESTERDAY WILL EJECT NORTHEAST OUT INTO THE PLAINS TODAY...BUT ADDITIONAL UPPER ENERGY WILL DROP INTO THE BASE OF A DEEPENING LONGWAVE TROUGH TODAY. THIS UPPER TROUGH WILL ENGULF THE CENTRAL US BY TOMORROW...A PATTERN THAT IS VERY UNUSUAL FOR MID MAY. THIS SYSTEM HAS TAPPED INTO A CANADIAN AIRMASS AND HAS SENT AN UNSEASONABLY STRONG COLD FRONT BARRELING SOUTH. AT 4AM...THIS FRONT WAS LOCATED JUST SOUTH OF LUBBOCK TO NEAR VERNON TO EL RENO OKLAHOMA AND WAS MOVING SOUTHEAST AT 15 TO 20MPH. THE FRONT IS AHEAD OF MOST MODEL PROJECTIONS...WHICH IS NOT SURPRISING GIVEN THE COLD AIR BEHIND IT. THE RAP HAS A GOOD HANDLE ON THE FRONT/S SPEED AND IT WILL BE USED FOR TIMING. THE FRONT WILL ARRIVE INTO THE NORTHWEST CWA BY MID-MORNING AND CONTINUE TO TRACK SOUTHEAST...BUT SLOW DOWN A BIT DUE TO DAYTIME HEATING. THE FRONT SHOULD REACH A SHERMAN TO DFW TO COMANCHE LINE BY MID-AFTERNOON. THE AIRMASS AHEAD OF THE FRONT WILL BE WARM AND MOIST...WITH SEVERAL DAYS OF SOUTHERLY FLOW NOW BRINGING PRECIPITABLE WATER VALUES UP TO 1.75 TO 2 INCHES. SURFACE BASED CAPE WILL PEAK AROUND 2000-2500 J/KG THIS AFTERNOON AS TEMPS WARM INTO THE MID 80S. DAYTIME HEATING AND FORCING FOR ASCENT FROM THE UPPER LEVEL TROUGH WILL LIFT/ERODE THE WEAK CAPPING INVERSION...AND THUS CONVECTION WILL INCREASE IN COVERAGE ALONG THE FRONT BY LATE MORNING. BULK LAYER SHEAR IS FAIRLY WEAK...ON THE ORDER OF 25KT...SO MULTICELLULAR CONVECTIVE MODES ARE EXPECTED. GIVEN THE HIGH INSTABILITY AND WEAK SHEAR...SOME SEVERE WIND/HAIL REPORTS ARE POSSIBLE TODAY WITH THE STRONGEST STORMS. CONVECTION ALONG THE FRONT WILL LIKELY CONGEAL INTO A SOLID LINE OF THUNDERSTORMS BY MID-AFTERNOON...WITH THE LINE CONTINUING TO GROW UPSCALE INTO A FORMIDABLE LINEAR MCS BY THE EVENING HOURS. MCS PROPAGATION VECTORS AND DIFFLUENT THICKNESS FIELDS ALOFT SUGGEST THAT THE MOVEMENT OF THIS SYSTEM WILL REMAIN FAIRLY SLOW...LIKELY LESS THAN 10-15MPH. THIS FORWARD SPEED SHOULD IN THEORY LIMIT THE DAMAGING WIND THREAT THIS EVENING OVER THE SOUTHEAST HALF OF THE CWA...BUT WILL RESULT IN ENHANCED RAINFALL TOTALS. THE MCS WILL LIKELY HAVE SLOWER WEST TO EAST MOVEMENT THAN NORTH TO SOUTH...AND THUS THE ORIENTATION OF THE LINE SUGGESTS THAT EASTERN ZONES WILL HAVE A GREATER RISK FOR PROLONGED HEAVY RAINFALL. EXPECT THE LINE TO PUSH THROUGH THE SOUTHWEST ZONES FAIRLY QUICKLY...LIKELY REACHING A LAMPASAS TO WACO LINE BY 6 PM. A TIGHT RAINFALL GRADIENT IS FORECAST OVER THE CWA WITH LESS THAN A HALF INCH EXPECTED OVER THE NW ZONES...TO 1-2 INCHES IN A BAND FROM THE SHERMAN AREA TO THE METROPLEX TO COMANCHE...AND 2-3 INCHES SOUTH AND EAST OF A PARIS TO GREENVILLE TO HILLSBORO LINE. THIS LATTER REGION WAS THE SAME AREA THAT RECEIVED A SWATH OF 2-4 INCHES OF RAIN THURSDAY AND SOILS ARE ALREADY SATURATED. THUS A FLASH FLOOD WATCH WAS ISSUED FOR LOCATIONS ALONG AND SOUTHEAST OF A BONHAM TO DALLAS TO TEMPLE LINE. WHILE WE DONT EXPECT MOST OF DALLAS AND COLLIN COUNTIES TO RECEIVE MORE THAN 2 INCHES...GIVEN THE URBAN DEVELOPMENT THERE AND THE FACT THAT THE SOUTHEAST PARTS OF THESE COUNTIES DID SEE OVER 4 INCHES...FELT IT WAS BEST TO INCLUDE THEM. FARTHER SOUTH...FROM WACO TO ATHENS...LESS RAIN FELL IN THIS AREA LAST THURSDAY...BUT QUICK TOTALS OF 2-3 INCHES ARE POSSIBLE THIS EVENING. FOR WACO/TEMPLE/KILLEEN ONLY AROUND 2 INCHES ARE FORECAST...BUT AGAIN URBAN INFRASTRUCTURE MAY EXACERBATE ANY FLOODING...SO THEY WERE INCLUDED IN THE WATCH TOO. BECAUSE THE UPPER LEVEL TROUGH WILL BE SLOW TO MOVE EAST...CONTINUED SOUTHERLY FLOW ALOFT BEHIND THE FRONT/LINE OF STORMS WILL OCCUR THIS EVENING. THUS THE LINE OF STORMS WILL LIKELY BE SUCCEEDED BY A FEW HOURS OF STEADY LIGHT TO MODERATE STRATIFORM RAINS...ESPECIALLY ACROSS THE WATCH AREA. THIS ACTIVITY SHOULD END FROM NORTHWEST TO SOUTHEAST LATE TONIGHT...BUT MAY LINGER OVER THE SOUTHEAST ZONES INTO TUESDAY MORNING. TUESDAY SHOULD BE DRY FOR THE REMAINDER OF THE AREA WITH MOSTLY CLOUDY AND COOL CONDITIONS AS COOLER AIR POURS INTO THE REGION BEHIND THE FRONT. FORECAST HIGH TEMPS MAY BE TOO WARM...BUT IT WOULD ONLY TAKE AN HOUR OR TWO OF AFTERNOON MAY SUNSHINE TO WARM US INTO THE MID 60S...SO STAYED CONSERVATIVE THERE. THE STRONGEST UPPER LEVEL FORCING WILL CROSS THE REGION TUESDAY EVENING BUT THE AIRMASS WILL BE PRETTY WORKED OVER. HOWEVER THIS FORCING SHOULD RESULT IN SCATTERED ELEVATED SHOWERS AND A FEW STORMS OVER THE REGION AND SHOULD SQUEEZE OUT ANOTHER TENTH TO QUARTER INCH OF RAINFALL. HAVE BUMPED POPS UP TUESDAY NIGHT AS MODEL GUIDANCE HAS COME INTO BETTER AGREEMENT ON THIS ROUND. OTHERWISE THE REMAINDER OF THE FORECAST LOOKS QUIET AND VERY NICE FOR MID TO LATE MAY. DRY NORTHWESTERLY FLOW ALOFT WILL PREVAIL THROUGH THE WEEKEND LEADING TO CLEAR SKIES AND LIGHT WINDS. GOOD RADIATIONAL COOLING WEDNESDAY NIGHT WILL SEND LOW TEMPS DOWN INTO THE 40S AREA WIDE...AND WACO MAY BREAK ITS RECORD LOW OF 46. HIGHS IN THE UPPER 60S ARE EXPECTED THURSDAY...BUT TEMPS SHOULD WARM INTO THE 70S FRIDAY AND THE 80S BY THE WEEKEND. DRY WEATHER WILL CONTINUE INTO NEXT WEEK WITH TEMPS WARMING TO ABOVE NORMAL. TR.92 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 83 54 66 51 68 / 90 80 20 40 10 WACO, TX 87 57 65 51 69 / 70 100 40 60 10 PARIS, TX 84 56 63 51 64 / 70 90 20 50 20 DENTON, TX 80 52 65 49 68 / 80 70 20 40 10 MCKINNEY, TX 83 53 64 50 68 / 90 80 20 40 10 DALLAS, TX 84 55 65 52 68 / 90 80 20 50 10 TERRELL, TX 85 57 64 51 67 / 70 90 20 50 20 CORSICANA, TX 86 59 64 52 67 / 60 100 40 60 20 TEMPLE, TX 87 58 64 52 69 / 50 100 50 60 10 MINERAL WELLS, TX 79 50 66 47 71 / 70 60 20 30 10 && .FWD WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM THIS AFTERNOON THROUGH LATE TONIGHT FOR TXZ094-095-104>107-119>123-134-135-145>148-158>162-174-175. && $$
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1248 AM CDT MON MAY 12 2014 .DISCUSSION...NOTE AVIATION DISCUSSION BELOW. && .AVIATION...MVFR/IFR CEILINGS EXPECTED OVERNIGHT. MVFR/VFR CEILINGS EXPECTED DRG THE DAYTIME MONDAY ALONG WITH THE POSSIBILITY OF SHOWERS AND THUNDERSTORMS...WITH MVFR VISIBILITIES... DRG THE AFTN MAINLY WEST OF U.S. ROUTE 77. THE CHANCE FOR SHOWERS AND THUNDERSTORMS WL INCREASE MONDAY EVENING/NIGHT. ANTICIPATE THAT VERTICAL WIND SHEAR WL REMAIN BELOW NON-CONVECTIVE LLWS CRITERION OVERNIGHT. MODERATE/BREEZY ONSHORE FLOW EXPECTED DRG THE LATE MORNING/AFTN. && .PREV DISCUSSION... /ISSUED 917 PM CDT SUN MAY 11 2014/ DISCUSSION...MINOR TEMPERATURE/DEW POINT ADJUSTMENTS TO FALL IN LINE WITH CURRENT/FORECAST TEMPERATURES. SEE NO REASON AT THIS TIME TO MAKE OTHER CHANGES INLAND AREAS. MARINE...INCLUDED PATCHY FOG FOR THE MARINE ZONES AND SOME LOCATIONS REPORTING 2-5SM. WILL PUT A BRIEF MENTION OF THIS IN MWW. AM KEEPING SCA GOING AS THIS IS WHAT THE RUC IS SHOWING AND OTHER MODELS TOO. PREV DISCUSSION... /ISSUED 644 PM CDT SUN MAY 11 2014/ DISCUSSION...UPDATE FOR 00Z AVIATION DISCUSSION. AVIATION...DETERIORATING FLIGHT RULES OVERNIGHT. MVFR EARLY IN THE TAF PERIOD AT KCRP/KVCT/KALI WITH CONDITIONS QUICKLY LOWERING TO IFR BY MID EVENING...AND REMAINING AT IFR OVERNIGHT. KLRD SHOULD REMAIN VFR THRU MUCH OF THE NIGHT WITH CIGS LOWERING TO IFR BY LATE IN THE NIGHT. CIGS AT ALL TERMINALS WILL SLOWLY RISE MON MRNG WITH MVFR TO VFR RETURNING TO KLRD BY LATE MRNG...KALI BY MIDDAY...WITH KCRP/KVCT LIKELY REMAINING AT MVFR THRU MON AFTN. ISO CONVECTION MAY APPROACH KLRD BY LATE MON AFTN BUT BETTER CHANCES WILL OCCUR JUST BEYOND VALID TAF TIME FRAME...SO WILL ONLY INCLUDE VCTS FOR NOW. ELSEWHERE...CURRENTLY XPCT KCRP/KVCT/KALI TO REMAIN DRY THRU THE TAF PERIOD ASIDE FROM SOME BRIEF -DZ. MODERATE/GUSTY SE WINDS THIS EVENING WILL REMAIN BETWEEN 08-14 KTS OVERNIGHT...WITH GUSTY SE WINDS RETURNING FOR MIDDAY/AFTN HRS OF MON. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 88 73 76 59 75 / 30 50 70 60 20 VICTORIA 88 72 75 57 75 / 30 60 70 60 20 LAREDO 96 74 80 61 79 / 40 70 60 40 10 ALICE 91 72 77 58 76 / 30 60 70 60 20 ROCKPORT 84 73 75 62 74 / 20 40 70 60 20 COTULLA 92 71 77 57 78 / 40 70 50 40 10 KINGSVILLE 90 73 77 59 76 / 30 50 70 60 20 NAVY CORPUS 84 73 75 61 74 / 20 40 60 60 20 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. && $$ WC/87...AVIATION
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1157 PM CDT SUN MAY 11 2014 .AVIATION... /06Z TAFS/ Thunderstorms and widespread MVFR ceilings do not look likely for the remainder of tonight. The latest satellite imagery indicates stratus is returning. However, the latest METAR for Junction indicates a broken ceiling at only twenty nine hundred feet above ground level. So, stratus may not be as low as the previous forecast package indicated. Thunderstorms, associated with the cold front, still look possible for tomorrow. && .PREV DISCUSSION... /ISSUED 813 PM CDT SUN MAY 11 2014/ DISCUSSION... Despite the instability in place and persistent cumulus field, thunderstorms have not developed along the dryline so far this evening in the eastern TX Panhandle or Low Rolling Plains east of Lubbock. Surface convergence is weak and upper forcing is still lagging to the west over the southern Rockies. The dryline farther south is retreating to the west. The GFS looks to be the the most optimistic with convective development early tonight before 06Z in our northern and western counties. Recent HRRR and Texas Tech WRF, however, hold off with shower/thunderstorm development until 2-3 hours after Midnight across our far western counties. The Texas Tech WRF indicates possibility of isolated thunderstorm development near our northwestern border counties (Fisher and Nolan Counties) late this evening/early tonight. Given the satellite and model trends, have scaled back the PoPs early tonight with slight chance confined to the the area west of Haskell to Sweetwater before 2 AM. With the instability and deep layer shear, severe potential remains for any storms which can develop on the dryline. As large scale ascent begins to impinge on the area late tonight, could have shower/thunderstorm development across our west and northwest counties, spreading east overnight and early Monday morning. Carrying 30-40 PoPs across the area north and west of a San Angelo to Baird line late tonight. Have also adjusted sky condition to clear skies this evening based on satellite indications. Updated forecast will be out shortly. 19 PREV DISCUSSION... /ISSUED 650 PM CDT SUN MAY 11 2014/ AVIATION... /00Z TAFS/ Thunderstorms and MVFR ceilings are possible across West Central Texas during the next 24 hours. Forecast models indicate stratus will return to our southern terminals a couple hours after midnight. The best timing for thunderstorms will also begin after midnight and continue through tomorrow, as another cold front moves into West Central Texas. PREV DISCUSSION... /ISSUED 335 PM CDT SUN MAY 11 2014/ SHORT TERM... (Tonight and Monday) A fairly complex weather forecast can be expected through the next 24 hours. Currently a dryline is located west of the area, with all of West Central Texas experiencing dewpoints in the mid 50s to lower 60s. The dryline is forecast to continue to sharpen to our west this afternoon, with an increasingly unstable atmosphere ahead of it. The main caveat is the lack of upper level forcing, and whether we are able to break the cap late this afternoon or early this evening. My current thinking is that we will see at least isolated convection along the dryline, mainly beginning this evening as better upper level forcing arrives, then moving east late this evening and early Monday morning. A strengthening low level jet should help to sustain any convection that does develop, with most convection waning by sunrise. Any storms that do develop this evening, have the potential to become strong to severe, with large hail and damaging winds being the main hazards. The main feature of interest on Monday is a cold front that will slowly move through the area. The front is forecast to move into the northern Big Country late Monday morning, then into the Concho Valley during the afternoon, with a dryline extending south across the northern Edwards Plateau. Showers and thunderstorms are forecast to develop along and ahead of the front late in the morning, then increase in coverage by mid to late afternoon. At this time, the best coverage and heaviest rainfall looks to generally east of a Cross Plains, to Eden, to Junction line, where precipitable water values of 1 to 1.5 inches are forecast. Again, a few storms could become strong to severe, with large hail and damaging winds being the main hazards. Daniels LONG TERM... (Monday night through Sunday) ..A heavy rainfall threat will exist through Monday night... A very slow moving cold front will ease across the southeast quadrant of the CWA Monday night, providing a low-level focus for convective development. Ascent will be aided by strong upper-level divergence in the right entrance region to the polar jet. Forecast precipitable water values Monday night are progged to be in the 1.4 to 1.7" range, about 2 standard deviations above the mean for this time of year. The 0-6km shear vector will be nearly parallel with the aforementioned frontal boundary, suggesting that storms may train along the baroclinic zone, enhancing the potential for locally heavy rainfall. Widespread showers and thunderstorms will result in general rainfall amounts of 1-3", with locally higher amounts, generally east of a Cross Plains to Junction line. Farther west, QPF amounts are quite a bit lighter, but a good 1/4" of rain or more is expected from Sweetwater south to Sonora. There is a threat for severe thunderstorms as well, mainly during the afternoon and evening hours before convection congeals into a multicell mess. The primary threats will be large hail and damaging winds. The cold front will be south of the area by Tuesday morning with north winds of 15-20 mph expected throughout the day. Upper-level forcing will remain present, but without the frontal forcing, it looks like precipitation will be weaker, with thunder becoming less likely. PoPs in the 20-40% range were carried southeast of an Ozona to Cross Plains line, but rainfall amounts should remain less than 1/4" on average. Temperatures will be noticeably cooler on Tuesday with highs generally in the mid 60s. The NAM is still keeping highs in the 50s across the area but this seems a bit extreme. Precip is expected to come to an end by Tuesday evening with drier air advecting into the area overnight. As winds decrease, the dry air should allow fairly strong decoupling of the boundary layer. With skies clearing, temps are expected to fall into the low/mid 40s. North to northeast winds on Wednesday will keep temps on the cool side, with highs only the 70s. We`re in store for another cool morning on Thursday with 40s once again expected across most of the area. Generally benign weather conditions are expected through the remainder of the forecast period. Dry northwesterly flow downstream of the western CONUS ridge will promote mostly clear skies. Southerly winds will resume across the area by Thursday as lee cyclogenesis ramps up. With the return flow, temps will rebound quickly into the 80s with highs expected to reach 90 degrees over the weekend. This is a potential cold front we`ll have to watch out for Friday into Saturday as a potent shortwave trough moves across the central Plains. However, the current model guidance stalls this boundary near the Red River, maintaining southerly winds across the region. Johnson FIRE WEATHER... Elevated fire weather conditions are forecast across the western Concho Valley and Crockett County Monday afternoon. Minimum relative humidity values will drop below 20 percent, but 20 foot winds will remain light. Elevated fire weather conditions will once again be possible across much of West Central Texas Wednesday through Friday, as minimum relative humidity values drop to 15 to 20 percent, but 20 foot winds generally remain below 15 mph. && .PRELIMINARY POINT TEMPS/POPS... Abilene 69 80 50 66 46 / 30 40 20 10 5 San Angelo 69 84 52 65 44 / 30 30 30 10 5 Junction 72 82 57 68 47 / 10 50 70 40 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
843 AM EDT MON MAY 12 2014 .SYNOPSIS... HIGH PRESSURE OFF THE SOUTHEAST COAST IS GOING TO KEEP OUR REGION IN A INCREASINGLY HUMID AIRMASS. A SLOW MOVING FRONT ENTERS THE REGION BY THURSDAY AND SLIDES EAST FRIDAY. A COOLER AIRMASS FOLLOWS THIS FRONT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 700 AM EDT MONDAY... FEW SHOWERS ACROSS GREENBRIER COUNTY WV THIS MORNING...OTHERWISE MAINLY SEEING SOME AC/CI. UPDATES JUST REFLECT TRENDS IN TEMPS/SKY COVER WITH ISOLATED POPS IN THE NW CWA. PREVIOUS VALID DISCUSSION... DESPITE INCREASING 5H HEIGHTS TODAY...WILL STILL SEE A COUPLE OF EMBEDDED SHORTWAVES RIDE THE NRN CENTER OF THE HIGH ACROSS OUR AREA. EARLY THIS MORNING...THERE IS A WEAK SHORTWAVE MOVING ACROSS WV WITH TAIL END OF SHOWERS PUSHING EAST BETWEEN BKW-CRW BUT WEAKENING. THE LATEST HRRR SHOWS THIS AREA MAYBE SCRAPING NRN GREENBRIER AND BATH. OVERALL...SHOULD BE A DRY MORNING WITH PATCH FOG IN THE VALLEYS/RIVER AREAS. TODAY...THE SFC HIGH OFF THE COAST WILL CONTINUE TO KEEP MOISTURE STREAMING NWD INTO THE CENTRAL APPALACHIANS. HEATING WILL LEAD TO INSTABILITY AND OVERALL WEAK FORCING FAVORS SCATTERED SHOWERS AND STORMS POPPING AROUND MIDDAY IN THE MTNS WITH STEERING FLOW TAKING THEM EAST TO THE BLUE RIDGE AND FOOTHILLS DURING THE AFTERNOON. FURTHER SOUTH ACROSS NC/SOUTHSIDE VA...AIRMASS MAY BE JUST CAPPED ENOUGH TO LIMIT CONVECTION...ALTHOUGH A FEW SHOULD SKIRT BY THIS EVENING WHEN CAP WEAKENS. OVERALL KEPT POPS UNDER HIGH CHANCE...BUT WILL BE A CASE WHERE 1/3-1/2 OF A COUNTY GETS RAINED ON...WHILE THE OTHER HALF MISSES OUT. FOR HIGHS WILL SEE MOSTLY SUNNY SKIES EARLY WITH CU/TCU DEVELOPING WITH SOME AC/CI OVERTOP. THIS WILL LIMIT HEATING MAINLY OVER THE MOUNTAINS BUT STILL LOOKING AT TEMPS RUNNING AROUND 10 DEGREES ABOVE NORMAL. HIGHS RANGING FROM THE UPPER 70S/LOWER 80S WEST TO NEAR 90 SOUTHEAST. TONIGHT...CONVECTION WEAKENS WITH LOSS OF HEATING. THE 00Z WRF/NAM HOLD ONTO ACTIVITY INTO LATE EVENING WHILE THE OTHER MODELS SHOWING LITTLE TO NONE AFTER 00Z/8 PM. WILL LEAN TOWARD THE HIGHER RES MODELS SINCE ANY OUTFLOW COULD KEEP A SHOWER/STORM GOING PAST 8 PM. BY MIDNIGHT WILL BE CLEAR TO PARTLY CLOUDY AND HUMID WITH LOWS IN THE UPPER 50S TO LOWER 60S. FOG COULD BECOME AN ISSUE SINCE RAIN SHOWERS ARE EXPECTED THIS AFTERNOON...ALTHOUGH COVERAGE WILL BE PATCHY. && .SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/... AS OF 415 AM EDT MONDAY... UPPER LEVEL RIDGING WILL BE FIRMLY IN PLACE TUESDAY MORNING ACROSS THE EASTERN SEABOARD...WHICH WILL RESULT IN VERY SUMMER LIKE TEMPERATURES. EXPECT AFTERNOON HIGHS TO RANGE FROM THE LOW/MID 80S ACROSS THE MOUNTAINS... TO THE LOW 90S ACROSS THE SOUTHSIDE. STRONG HEATING AND CONTINUED MOISTURE INFLOW SHOULD HELP KICK OFF A FEW SHOWERS AND THUNDERSTORMS DURING LATE AFTERNOON AND EARLY EVENING... HOWEVER THE RIDGING WILL KEEP THIS ACTIVITY SPOTTY AT BEST AND DISORGANIZED. WILL BE KEEPING AN EYE ON A COLD FRONT BACK DOORING ITS WAY SOUTHWARD FROM NEW ENGLAND DURING THE AFTERNOON AND EVENING...BUT DO NOT THINK IT WILL APPROACH CLOSE ENOUGH TO ENHANCE CONVECTION OVER OUR AREA. AT ANY RATE...ANY CONVECTION SHOULD GRADUALLY FIZZLE TOWARD SUNSET...AND PATCHY FOG WILL BE POSSIBLE TUESDAY NIGHT...ESPECIALLY IN AREAS WHICH DO RECEIVE A DOWNPOUR. BETTER CHANCES FOR SHOWER AND THUNDERSTORMS WILL OCCUR ON WEDNESDAY AS UPPER LEVEL RIDGING BEGINS TO SHIFT EAST...WHILE THE BACK DOOR FRONT STALLS ACROSS NORTHERN VIRGINIA JUST OUTSIDE OUR FORECAST REGION. ANOTHER DAY OF STRONG HEATING AS HIGHS REACH INTO THE 80S MOST LOCATIONS...COMBINED WITH LOW LEVEL CONVERGENCE ASSOCIATED WITH THE NEARBY FRONT...WILL LEAD TO HIGHER RAIN CHANCES ACROSS THE MOUNTAINS AND THE PIEDMONT NORTH OF HIGHWAY 460. THE INCREASED INSTABILITY WILL ALLOW FOR GREATER POTENTIAL FOR ORGANIZED THUNDERSTORM ACTIVITY...AND A FEW STORMS WILL LIKELY BECOME STRONG DURING LATE AFTERNOON AND EARLY EVENING...CAPABLE OF PRODUCING LOCALLY STRONG WINDS AND HAIL. WILL SEE THE BOUNDARY ACROSS NORTHERN VIRGINIA LIFT TOWARD NEW ENGLAND DURING LATE EVENING AS A WARM FRONT...WHILE A STRONG COLD FRONT APPROACHES OUR REGION FROM THE WEST. THE COLD FRONT WILL ENTER OUR WESTERN MOST COUNTIES DURING MID AFTERNOON...RESULTING IN WAVES OF LOCALLY HEAVY RAIN AS UPPER LEVEL DISTURBANCES PASS OVERHEAD ALONG THE BOUNDARY. MODELS ARE PICKING UP ON AT LEAST ONE STRONG WAVE POTENTIALLY BRINGING HEAVY RAIN TO THE FOOTHILLS AND THE PIEDMONT DURING THE EVENING...AND POSSIBLY A SECOND WAVE IF THE COLD FRONT SLOWS/STALLS BEFORE EXITING OUR REGION DURING EARLY FRIDAY MORNING. STILL NOT ENOUGH CONFIDENCE IN THE MODELS TO TACK DOWN RAINFALL AMOUNTS...BUT IT IS LOOKING SAFE TO SAY THAT THE MUCH OF THE REGION WILL RECEIVE BETWEEN ONE AND TWO INCHES FOR THE THURSDAY AND EARLY FRIDAY TIME PERIOD...WITH SOME AREAS PICKING IN EXCESS OF 3 INCHES...ESPECIALLY ALONG THE BLUE RIDGE. MODELS ARE IN DECENT AGREEMENT THAT THE FRONT AND ASSOCIATED HEAVY RAIN WILL BE EAST OF OUR AREA DURING EARLY FRIDAY AFTERNOON... LEAVING ONLY RESIDUAL SHOWER ACTIVITY...AS WELL AS A SHARP DROP IN TEMPERATURES AS A DEEP UPPER TROUGH APPROACHES FROM THE WEST. && .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 400 PM EDT SUNDAY... AN AMPLIFIED MID-UPPER LEVEL MEAN TROUGH SETTLES OVER THE ERN HALF OF THE CONUS FOR THE LATTER HALF OF THE WEEK AND INTO NEXT WEEKEND. AS WE TRANSITION INTO THE WEEKEND...FLOW BECOMES BLOCKY WITH A DEEP QUASI-STATIONARY...ALMOST WINTERLIKE UPPER LOW PARKED OVER THE GREAT LAKES REGION. 850MB TEMPS WILL DROP INTO THE 3C TO 6C RANGE FOR MOST OF THE CWA AND LINGER IN THIS RANGE FOR SEVERAL DAYS. SEVERAL SPOKES OF PVA ARE EXPECTED TO ROTATE AROUND THIS UPPER LOW WHICH SUGGESTS POTENTIAL FOR CLOUDS AND SHOWERS... ESPECIALLY ACROSS THE MOUNTAINS. TEMPERATURES WILL TREND TO THE COOLER SIDE OF NORMAL. FORTUNATELY...CLOUDS...SHOWERS...AND A BIT OF A NW BREEZE SHOULD MITIGATE FROST POTENTIAL. NONETHELESS...IT WILL BE QUITE CHILLY WITH HIGHS IN THE 60S AND LOWS IN THE 40S ACROSS MUCH OF THE REGION...A BIG CONTRAST FROM THE WARMTH THE FIRST HALF OF THIS WEEK. && .AVIATION /13Z MONDAY THROUGH FRIDAY/... AS OF 710 AM EDT MONDAY... NOT MUCH CHANGE FROM PREVIOUS TAFS. MODELS STILL SHOWING A SCATTERING OF CONVECTION BETWEE 16-18Z TODAY OVER THE MOUNTAINS...AND SKIRTING TOWARD LYH BY 20Z. STILL TOO LOOSE OF COVERAGE TO HAVE ANYTHING MORE THAN VCTS IN THE TAFS ASIDE FROM BLF. ASIDE FROM THE STORMS...EXPECT VFR. THIS EVENING...CONVECTION WANES AND SKIES WILL BE CLEAR/PC AND VFR. SOME MVFR VSBYS AND POSSIBLY LOWER OVERNIGHT. WILL HAVE TO SEE WHERE IT RAINS THIS AFTERNOON WHICH CAN SET UP MORE FOG OVERNIGHT. RIGHT NOW CONFIDENCE HIGH THAT AT LEAST THE CLIMO FAVORED STATIONS OF LWB/BCB GET MVFR VSBYS OVERNIGHT. FORECAST FAVORS SLOWING OF THE FRONT SO THAT NOW EVEN WEDNESDAY COULD HAVE LESS COVERAGE. UNTIL THE FRONT GETS CLOSER EXPECT MAINLY VFR WITH POP UP STORMS IN THE AFTERNOON...AND MAYBE FOG ENTERING THE PICTURE MORE OVERNIGHT AT MOST SITES OUTSIDE OF BLF/LWB. HEAVY RAINS AND STORMS WILL BE AFFECTING OUR REGION BY THURSDAY AND COULD LINGER INTO EARLY FRIDAY. SO DURING THE WED-FRI TIME FRAME GOOD CHANCE OF SUB VFR VSBYS/CIGS. && .CLIMATE... TEMPERATURES REMAIN VERY WARM MONDAY AND TUESDAY. MONDAYS RECORD HIGH FOR BLUEFIELD WV IS 83 DEGREES AND IN BLACKSBURG VA IT IS 85 DEGREES. THESE ARE THE ONLY TWO LOCATIONS MONDAY WHERE HIGH TEMPERATURES MAY TIE OR EXCEED THE CURRENT RECORD HIGH TEMPERATURE. TEMPERATURES ARE EXPECTED TO BE EVEN WARMER ON TUESDAY ALLOWING ALL CLIMATE STATIONS TO HAVE A SHOT AT BREAKING A RECORD. HERE ARE THE CURRENT RECORD HIGH TEMPERATURES FOR TUESDAY: MAY 13 ROA92 (2000) LYH92 (1956) DAN93 (2000) BCB84 (2000) BLF83 (2010) LWB 84 (2000) && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...PC/WP NEAR TERM...WP SHORT TERM...NF LONG TERM...PM AVIATION...RCS/WP CLIMATE...CF
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
718 AM EDT MON MAY 12 2014 .SYNOPSIS... HIGH PRESSURE OFF THE SOUTHEAST COAST IS GOING TO KEEP OUR REGION IN A INCREASINGLY HUMID AIRMASS. A SLOW MOVING FRONT ENTERS THE REGION BY THURSDAY AND SLIDES EAST FRIDAY. A COOLER AIRMASS FOLLOWS THIS FRONT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 700 AM EDT MONDAY... FEW SHOWERS ACROSS GREENBRIER COUNTY WV THIS MORNING...OTHERWISE MAINLY SEEING SOME AC/CI. UPDATES JUST REFLECT TRENDS IN TEMPS/SKY COVER WITH ISOLATED POPS IN THE NW CWA. PREVIOUS VALID DISCUSSION... DESPITE INCREASING 5H HEIGHTS TODAY...WILL STILL SEE A COUPLE OF EMBEDDED SHORTWAVES RIDE THE NRN CENTER OF THE HIGH ACROSS OUR AREA. EARLY THIS MORNING...THERE IS A WEAK SHORTWAVE MOVING ACROSS WV WITH TAIL END OF SHOWERS PUSHING EAST BETWEEN BKW-CRW BUT WEAKENING. THE LATEST HRRR SHOWS THIS AREA MAYBE SCRAPING NRN GREENBRIER AND BATH. OVERALL...SHOULD BE A DRY MORNING WITH PATCH FOG IN THE VALLEYS/RIVER AREAS. TODAY...THE SFC HIGH OFF THE COAST WILL CONTINUE TO KEEP MOISTURE STREAMING NWD INTO THE CENTRAL APPALACHIANS. HEATING WILL LEAD TO INSTABILITY AND OVERALL WEAK FORCING FAVORS SCATTERED SHOWERS AND STORMS POPPING AROUND MIDDAY IN THE MTNS WITH STEERING FLOW TAKING THEM EAST TO THE BLUE RIDGE AND FOOTHILLS DURING THE AFTERNOON. FURTHER SOUTH ACROSS NC/SOUTHSIDE VA...AIRMASS MAY BE JUST CAPPED ENOUGH TO LIMIT CONVECTION...ALTHOUGH A FEW SHOULD SKIRT BY THIS EVENING WHEN CAP WEAKENS. OVERALL KEPT POPS UNDER HIGH CHANCE...BUT WILL BE A CASE WHERE 1/3-1/2 OF A COUNTY GETS RAINED ON...WHILE THE OTHER HALF MISSES OUT. FOR HIGHS WILL SEE MOSTLY SUNNY SKIES EARLY WITH CU/TCU DEVELOPING WITH SOME AC/CI OVERTOP. THIS WILL LIMIT HEATING MAINLY OVER THE MOUNTAINS BUT STILL LOOKING AT TEMPS RUNNING AROUND 10 DEGREES ABOVE NORMAL. HIGHS RANGING FROM THE UPPER 70S/LOWER 80S WEST TO NEAR 90 SOUTHEAST. TONIGHT...CONVECTION WEAKENS WITH LOSS OF HEATING. THE 00Z WRF/NAM HOLD ONTO ACTIVITY INTO LATE EVENING WHILE THE OTHER MODELS SHOWING LITTLE TO NONE AFTER 00Z/8 PM. WILL LEAN TOWARD THE HIGHER RES MODELS SINCE ANY OUTFLOW COULD KEEP A SHOWER/STORM GOING PAST 8 PM. BY MIDNIGHT WILL BE CLEAR TO PARTLY CLOUDY AND HUMID WITH LOWS IN THE UPPER 50S TO LOWER 60S. FOG COULD BECOME AN ISSUE SINCE RAIN SHOWERS ARE EXPECTED THIS AFTERNOON...ALTHOUGH COVERAGE WILL BE PATCHY. && .SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/... AS OF 415 AM EDT MONDAY... UPPER LEVEL RIDGING WILL BE FIRMLY IN PLACE TUESDAY MORNING ACROSS THE EASTERN SEABOARD...WHICH WILL RESULT IN VERY SUMMER LIKE TEMPERATURES. EXPECT AFTERNOON HIGHS TO RANGE FROM THE LOW/MID 80S ACROSS THE MOUNTAINS... TO THE LOW 90S ACROSS THE SOUTHSIDE. STRONG HEATING AND CONTINUED MOISTURE INFLOW SHOULD HELP KICK OFF A FEW SHOWERS AND THUNDERSTORMS DURING LATE AFTERNOON AND EARLY EVENING... HOWEVER THE RIDGING WILL KEEP THIS ACTIVITY SPOTTY AT BEST AND DISORGANIZED. WILL BE KEEPING AN EYE ON A COLD FRONT BACK DOORING ITS WAY SOUTHWARD FROM NEW ENGLAND DURING THE AFTERNOON AND EVENING...BUT DO NOT THINK IT WILL APPROACH CLOSE ENOUGH TO ENHANCE CONVECTION OVER OUR AREA. AT ANY RATE...ANY CONVECTION SHOULD GRADUALLY FIZZLE TOWARD SUNSET...AND PATCHY FOG WILL BE POSSIBLE TUESDAY NIGHT...ESPECIALLY IN AREAS WHICH DO RECEIVE A DOWNPOUR. BETTER CHANCES FOR SHOWER AND THUNDERSTORMS WILL OCCUR ON WEDNESDAY AS UPPER LEVEL RIDGING BEGINS TO SHIFT EAST...WHILE THE BACK DOOR FRONT STALLS ACROSS NORTHERN VIRGINIA JUST OUTSIDE OUR FORECAST REGION. ANOTHER DAY OF STRONG HEATING AS HIGHS REACH INTO THE 80S MOST LOCATIONS...COMBINED WITH LOW LEVEL CONVERGENCE ASSOCIATED WITH THE NEARBY FRONT...WILL LEAD TO HIGHER RAIN CHANCES ACROSS THE MOUNTAINS AND THE PIEDMONT NORTH OF HIGHWAY 460. THE INCREASED INSTABILITY WILL ALLOW FOR GREATER POTENTIAL FOR ORGANIZED THUNDERSTORM ACTIVITY...AND A FEW STORMS WILL LIKELY BECOME STRONG DURING LATE AFTERNOON AND EARLY EVENING...CAPABLE OF PRODUCING LOCALLY STRONG WINDS AND HAIL. WILL SEE THE BOUNDARY ACROSS NORTHERN VIRGINIA LIFT TOWARD NEW ENGLAND DURING LATE EVENING AS A WARM FRONT...WHILE A STRONG COLD FRONT APPROACHES OUR REGION FROM THE WEST. THE COLD FRONT WILL ENTER OUR WESTERN MOST COUNTIES DURING MID AFTERNOON...RESULTING IN WAVES OF LOCALLY HEAVY RAIN AS UPPER LEVEL DISTURBANCES PASS OVERHEAD ALONG THE BOUNDARY. MODELS ARE PICKING UP ON AT LEAST ONE STRONG WAVE POTENTIALLY BRINGING HEAVY RAIN TO THE FOOTHILLS AND THE PIEDMONT DURING THE EVENING...AND POSSIBLY A SECOND WAVE IF THE COLD FRONT SLOWS/STALLS BEFORE EXITING OUR REGION DURING EARLY FRIDAY MORNING. STILL NOT ENOUGH CONFIDENCE IN THE MODELS TO TACK DOWN RAINFALL AMOUNTS...BUT IT IS LOOKING SAFE TO SAY THAT THE MUCH OF THE REGION WILL RECEIVE BETWEEN ONE AND TWO INCHES FOR THE THURSDAY AND EARLY FRIDAY TIME PERIOD...WITH SOME AREAS PICKING IN EXCESS OF 3 INCHES...ESPECIALLY ALONG THE BLUE RIDGE. MODELS ARE IN DECENT AGREEMENT THAT THE FRONT AND ASSOCIATED HEAVY RAIN WILL BE EAST OF OUR AREA DURING EARLY FRIDAY AFTERNOON... LEAVING ONLY RESIDUAL SHOWER ACTIVITY...AS WELL AS A SHARP DROP IN TEMPERATURES AS A DEEP UPPER TROUGH APPROACHES FROM THE WEST. && .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 400 PM EDT SUNDAY... AN AMPLIFIED MID-UPPER LEVEL MEAN TROUGH SETTLES OVER THE ERN HALF OF THE CONUS FOR THE LATTER HALF OF THE WEEK AND INTO NEXT WEEKEND. AS WE TRANSITION INTO THE WEEKEND...FLOW BECOMES BLOCKY WITH A DEEP QUASI-STATIONARY...ALMOST WINTERLIKE UPPER LOW PARKED OVER THE GREAT LAKES REGION. 850MB TEMPS WILL DROP INTO THE 3C TO 6C RANGE FOR MOST OF THE CWA AND LINGER IN THIS RANGE FOR SEVERAL DAYS. SEVERAL SPOKES OF PVA ARE EXPECTED TO ROTATE AROUND THIS UPPER LOW WHICH SUGGESTS POTENTIAL FOR CLOUDS AND SHOWERS... ESPECIALLY ACROSS THE MOUNTAINS. TEMPERATURES WILL TREND TO THE COOLER SIDE OF NORMAL. FORTUNATELY...CLOUDS...SHOWERS...AND A BIT OF A NW BREEZE SHOULD MITIGATE FROST POTENTIAL. NONETHELESS...IT WILL BE QUITE CHILLY WITH HIGHS IN THE 60S AND LOWS IN THE 40S ACROSS MUCH OF THE REGION...A BIG CONTRAST FROM THE WARMTH THE FIRST HALF OF THIS WEEK. && .AVIATION /11Z MONDAY THROUGH FRIDAY/... AS OF 710 AM EDT MONDAY... NOT MUCH CHANGE FROM PREVIOUS TAFS. MODELS STILL SHOWING A SCATTERING OF CONVECTION BETWEE 16-18Z TODAY OVER THE MOUNTAINS...AND SKIRTING TOWARD LYH BY 20Z. STILL TOO LOOSE OF COVERAGE TO HAVE ANYTHING MORE THAN VCTS IN THE TAFS ASIDE FROM BLF. ASIDE FROM THE STORMS...EXPECT VFR. THIS EVENING...CONVECTION WANES AND SKIES WILL BE CLEAR/PC AND VFR. SOME MVFR VSBYS AND POSSIBLY LOWER OVERNIGHT. WILL HAVE TO SEE WHERE IT RAINS THIS AFTERNOON WHICH CAN SET UP MORE FOG OVERNIGHT. RIGHT NOW CONFIDENCE HIGH THAT AT LEAST THE CLIMO FAVORED STATIONS OF LWB/BCB GET MVFR VSBYS OVERNIGHT. FORECAST FAVORS SLOWING OF THE FRONT SO THAT NOW EVEN WEDNESDAY COULD HAVE LESS COVERAGE. UNTIL THE FRONT GETS CLOSER EXPECT MAINLY VFR WITH POP UP STORMS IN THE AFTERNOON...AND MAYBE FOG ENTERING THE PICTURE MORE OVERNIGHT AT MOST SITES OUTSIDE OF BLF/LWB. HEAVY RAINS AND STORMS WILL BE AFFECTING OUR REGION BY THURSDAY AND COULD LINGER INTO EARLY FRIDAY. SO DURING THE WED-FRI TIME FRAME GOOD CHANCE OF SUB VFR VSBYS/CIGS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...PC/WP NEAR TERM...WP SHORT TERM...NF LONG TERM...PM AVIATION...RCS/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
501 AM EDT MON MAY 12 2014 .SYNOPSIS... HIGH PRESSURE OFF THE SOUTHEAST COAST IS GOING TO KEEP OUR REGION IN A INCREASINGLY HUMID AIRMASS. A SLOW MOVING FRONT ENTERS THE REGION BY THURSDAY AND SLIDES EAST FRIDAY. A COOLER AIRMASS FOLLOWS THIS FRONT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM EDT MONDAY... DESPITE INCREASING 5H HEIGHTS TODAY...WILL STILL SEE A COUPLE OF EMBEDDED SHORTWAVES RIDE THE NRN CENTER OF THE HIGH ACROSS OUR AREA. EARLY THIS MORNING...THERE IS A WEAK SHORTWAVE MOVING ACROSS WV WITH TAIL END OF SHOWERS PUSHING EAST BETWEEN BKW-CRW BUT WEAKENING. THE LATEST HRRR SHOWS THIS AREA MAYBE SCRAPING NRN GREENBRIER AND BATH. OVERALL...SHOULD BE A DRY MORNING WITH PATCH FOG IN THE VALLEYS/RIVER AREAS. TODAY...THE SFC HIGH OFF THE COAST WILL CONTINUE TO KEEP MOISTURE STREAMING NWD INTO THE CENTRAL APPALACHIANS. HEATING WILL LEAD TO INSTABILITY AND OVERALL WEAK FORCING FAVORS SCATTERED SHOWERS AND STORMS POPPING AROUND MIDDAY IN THE MTNS WITH STEERING FLOW TAKING THEM EAST TO THE BLUE RIDGE AND FOOTHILLS DURING THE AFTERNOON. FURTHER SOUTH ACROSS NC/SOUTHSIDE VA...AIRMASS MAY BE JUST CAPPED ENOUGH TO LIMIT CONVECTION...ALTHOUGH A FEW SHOULD SKIRT BY THIS EVENING WHEN CAP WEAKENS. OVERALL KEPT POPS UNDER HIGH CHANCE...BUT WILL BE A CASE WHERE 1/3-1/2 OF A COUNTY GETS RAINED ON...WHILE THE OTHER HALF MISSES OUT. FOR HIGHS WILL SEE MOSTLY SUNNY SKIES EARLY WITH CU/TCU DEVELOPING WITH SOME AC/CI OVERTOP. THIS WILL LIMIT HEATING MAINLY OVER THE MOUNTAINS BUT STILL LOOKING AT TEMPS RUNNING AROUND 10 DEGREES ABOVE NORMAL. HIGHS RANGING FROM THE UPPER 70S/LOWER 80S WEST TO NEAR 90 SOUTHEAST. TONIGHT...CONVECTION WEAKENS WITH LOSS OF HEATING. THE 00Z WRF/NAM HOLD ONTO ACTIVITY INTO LATE EVENING WHILE THE OTHER MODELS SHOWING LITTLE TO NONE AFTER 00Z/8 PM. WILL LEAN TOWARD THE HIGHER RES MODELS SINCE ANY OUTFLOW COULD KEEP A SHOWER/STORM GOING PAST 8 PM. BY MIDNIGHT WILL BE CLEAR TO PARTLY CLOUDY AND HUMID WITH LOWS IN THE UPPER 50S TO LOWER 60S. FOG COULD BECOME AN ISSUE SINCE RAIN SHOWERS ARE EXPECTED THIS AFTERNOON...ALTHOUGH COVERAGE WILL BE PATCHY. && .SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/... AS OF 415 AM EDT MONDAY... UPPER LEVEL RIDGING WILL BE FIRMLY IN PLACE TUESDAY MORNING ACROSS THE EASTERN SEABOARD...WHICH WILL RESULT IN VERY SUMMER LIKE TEMPERATURES. EXPECT AFTERNOON HIGHS TO RANGE FROM THE LOW/MID 80S ACROSS THE MOUNTAINS... TO THE LOW 90S ACROSS THE SOUTHSIDE. STRONG HEATING AND CONTINUED MOISTURE INFLOW SHOULD HELP KICK OFF A FEW SHOWERS AND THUNDERSTORMS DURING LATE AFTERNOON AND EARLY EVENING... HOWEVER THE RIDGING WILL KEEP THIS ACTIVITY SPOTTY AT BEST AND DISORGANIZED. WILL BE KEEPING AN EYE ON A COLD FRONT BACK DOORING ITS WAY SOUTHWARD FROM NEW ENGLAND DURING THE AFTERNOON AND EVENING...BUT DO NOT THINK IT WILL APPROACH CLOSE ENOUGH TO ENHANCE CONVECTION OVER OUR AREA. AT ANY RATE...ANY CONVECTION SHOULD GRADUALLY FIZZLE TOWARD SUNSET...AND PATCHY FOG WILL BE POSSIBLE TUESDAY NIGHT...ESPECIALLY IN AREAS WHICH DO RECEIVE A DOWNPOUR. BETTER CHANCES FOR SHOWER AND THUNDERSTORMS WILL OCCUR ON WEDNESDAY AS UPPER LEVEL RIDGING BEGINS TO SHIFT EAST...WHILE THE BACK DOOR FRONT STALLS ACROSS NORTHERN VIRGINIA JUST OUTSIDE OUR FORECAST REGION. ANOTHER DAY OF STRONG HEATING AS HIGHS REACH INTO THE 80S MOST LOCATIONS...COMBINED WITH LOW LEVEL CONVERGENCE ASSOCIATED WITH THE NEARBY FRONT...WILL LEAD TO HIGHER RAIN CHANCES ACROSS THE MOUNTAINS AND THE PIEDMONT NORTH OF HIGHWAY 460. THE INCREASED INSTABILITY WILL ALLOW FOR GREATER POTENTIAL FOR ORGANIZED THUNDERSTORM ACTIVITY...AND A FEW STORMS WILL LIKELY BECOME STRONG DURING LATE AFTERNOON AND EARLY EVENING...CAPABLE OF PRODUCING LOCALLY STRONG WINDS AND HAIL. WILL SEE THE BOUNDARY ACROSS NORTHERN VIRGINIA LIFT TOWARD NEW ENGLAND DURING LATE EVENING AS A WARM FRONT...WHILE A STRONG COLD FRONT APPROACHES OUR REGION FROM THE WEST. THE COLD FRONT WILL ENTER OUR WESTERN MOST COUNTIES DURING MID AFTERNOON...RESULTING IN WAVES OF LOCALLY HEAVY RAIN AS UPPER LEVEL DISTURBANCES PASS OVERHEAD ALONG THE BOUNDARY. MODELS ARE PICKING UP ON AT LEAST ONE STRONG WAVE POTENTIALLY BRINGING HEAVY RAIN TO THE FOOTHILLS AND THE PIEDMONT DURING THE EVENING...AND POSSIBLY A SECOND WAVE IF THE COLD FRONT SLOWS/STALLS BEFORE EXITING OUR REGION DURING EARLY FRIDAY MORNING. STILL NOT ENOUGH CONFIDENCE IN THE MODELS TO TACK DOWN RAINFALL AMOUNTS...BUT IT IS LOOKING SAFE TO SAY THAT THE MUCH OF THE REGION WILL RECEIVE BETWEEN ONE AND TWO INCHES FOR THE THURSDAY AND EARLY FRIDAY TIME PERIOD...WITH SOME AREAS PICKING IN EXCESS OF 3 INCHES...ESPECIALLY ALONG THE BLUE RIDGE. MODELS ARE IN DECENT AGREEMENT THAT THE FRONT AND ASSOCIATED HEAVY RAIN WILL BE EAST OF OUR AREA DURING EARLY FRIDAY AFTERNOON... LEAVING ONLY RESIDUAL SHOWER ACTIVITY...AS WELL AS A SHARP DROP IN TEMPERATURES AS A DEEP UPPER TROUGH APPROACHES FROM THE WEST. && .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 400 PM EDT SUNDAY... AN AMPLIFIED MID-UPPER LEVEL MEAN TROUGH SETTLES OVER THE ERN HALF OF THE CONUS FOR THE LATTER HALF OF THE WEEK AND INTO NEXT WEEKEND. AS WE TRANSITION INTO THE WEEKEND...FLOW BECOMES BLOCKY WITH A DEEP QUASI-STATIONARY...ALMOST WINTERLIKE UPPER LOW PARKED OVER THE GREAT LAKES REGION. 850MB TEMPS WILL DROP INTO THE 3C TO 6C RANGE FOR MOST OF THE CWA AND LINGER IN THIS RANGE FOR SEVERAL DAYS. SEVERAL SPOKES OF PVA ARE EXPECTED TO ROTATE AROUND THIS UPPER LOW WHICH SUGGESTS POTENTIAL FOR CLOUDS AND SHOWERS... ESPECIALLY ACROSS THE MOUNTAINS. TEMPERATURES WILL TREND TO THE COOLER SIDE OF NORMAL. FORTUNATELY...CLOUDS...SHOWERS...AND A BIT OF A NW BREEZE SHOULD MITIGATE FROST POTENTIAL. NONETHELESS...IT WILL BE QUITE CHILLY WITH HIGHS IN THE 60S AND LOWS IN THE 40S ACROSS MUCH OF THE REGION...A BIG CONTRAST FROM THE WARMTH THE FIRST HALF OF THIS WEEK. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... AS OF 120 AM EDT MONDAY... CIRRUS FROM UPSTREAM CONVECTION ALONG WITH SCATTERED AC WILL BE PUSHING ACROSS SE WV THIS MORNING AND PORTIONS OF THE ROA/BCB CORRIDOR. OVERALL THE CONDITIONS WILL BE VFR...WITH MOISTURE SITUATED IN THE SFC LAYER TO PROVIDE FOG POTENTIAL AT ALL SITES WITH BEST THREAT AT BCB/LWB...TO GO AS LOW AS LIFR AROUND 09-12Z. THE HIGH CLOUDINESS IF IT HANGS AROUND WILL PRECLUDE THIS BUT CONFIDENCE IS ENOUGH THINNING AND CALM WINDS TO ADD IT TO THE TAFS. TODAY...ANY FOG BURNS OFF AROUND 12-13Z. SW FLOW ALOFT PLUS HEATING THROUGH THE DAY WILL BE ENOUGH TO PRODUCE SCT/BKN CU...WITH HIGHER COVERAGE OVER THE MOUNTAINS. PER LATEST NAM/WRF...SHOULD SEE ISOLATED COVERAGE OF SHOWERS/STORMS IN THE PIEDMONT THIS AFTERNOON WITH SCATTERED COVERAGE ALONG AND WEST OF THE BLUE RIDGE. THINK HIGH PRESSURE ALOFT MAY CAP THINGS ACROSS SOUTHSIDE VA/DAN AND POINTS SOUTH. FOR NOW HAVE VCTS AT ALL BUT DAN DURING THE AFTERNOON...BEFORE TAKING IT OUT AROUND 0Z TUE. UPPER RIDGE ALOFT STRENGTHENS OVER THE REGION TUESDAY...PROVIDING MAINLY VFR CONDITIONS. THE UPPER RIDGE WILL SHIFT EAST OF THE REGION WEDNESDAY AS A STRONG COLD FRONT AND DEEPENING UPPER LOW MOVE INTO THE AREA FROM THE CENTRAL UNITED STATES. THIS SYSTEM HAS THE POTENTIAL TO BRING AN EXTENDED PERIOD OF SHRA/TSRA AND ASSOCIATED MVFR OR LOWER CIGS AND VSBYS TO THE REGION...LINGERING PERHAPS INTO EARLY FRIDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...PC/WP NEAR TERM...WP SHORT TERM...NF LONG TERM...PM AVIATION...RCS/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
328 PM CDT MON MAY 12 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 328 PM CDT MON MAY 12 2014 FOCUS OF THE FORECAST IS ON THE RAIN CHANCES AND IMPACTS TONIGHT. LATEST SURFACE ANALYSIS SUGGESTS THE INVERTED TROUGH/COLD FRONT EXTENDS FROM NORTHWEST WISCONSIN INTO WESTERN WISCONSIN. HARD TO DEFINE A COMPACT AREA OF LOW PRESSURE BUT LOOKS TO BE MORE OF AN ELONGATED FEATURE ALONG THE TROUGH/FRONT FROM SOUTHEAST MINNESOTA ACROSS MUCH OF IOWA. A WARM FRONT LOOKED TO EXTEND ACROSS NORTHEAST IOWA INTO NORTHERN ILLINOIS...ROUGHLY ALONG THE HIGHWAY 20 CORRIDOR. LOCAL AND REGIONAL RADARS SHOWING A LINE OF CONVECTION ALONG THE COLD FRONT FROM NORTHEAST IOWA INTO WESTERN MISSOURI/EASTERN KANSAS. LATEST ANALYSIS INDICATES AROUND 500 J/KG OF SB CAPE WAS ALONG INTERSTATE 90 BUT THIS INCREASED TO ALMOST 2000 J/KG ALONG THE SOUTHERN BORDER OF THE FORECAST AREA. THE 12.18Z RAP SUGGESTS THESE HIGHER CAPE VALUES WILL SPREAD ACROSS THE EASTERN PARTS OF THE FORECAST AREA THROUGH THE REST OF THE AFTERNOON INTO THE EARLY EVENING. THE RAP BUFKIT SOUNDINGS STILL SUGGESTS THIS IS PRIMARILY A TALL SKINNY CAPE PROFILE WHICH WOULD SUGGEST THAT LARGE HAIL MAY NOT BE MUCH OF A THREAT. FOR ANY STORMS THAT GET INTO THE AREA AND CAN ORIENT WITH THE 0-3KM SHEAR VECTORS...DAMAGING WIND WILL BE POSSIBLE. CANNOT TOTALLY RULE OUT AN ISOLATED TORNADO AS THE WARM FRONT MOVES INTO THE AREA...BUT BECAUSE OF THE ELONGATED SURFACE LOW...NOT REALLY SEEING ANY LOCALIZED BACKING OF THE WINDS TO ENHANCE THE LOW LEVEL HELICITY. CURRENTLY EXPECTING THE LINE OF ACTIVITY ACROSS IOWA INTO MISSOURI TO CONTINUE TRANSLATING NORTHEAST AHEAD OF THE TROUGH/FRONT AND PRIMARILY AFFECTING THE EASTERN SECTIONS OF THE FORECAST AREA FROM NORTHEAST IOWA INTO CENTRAL WISCONSIN. HAVE LINED UP THE RAIN CHANCES WITH 80 PERCENT OVER THIS AREA TRAILING BACK TO ABOUT A 40 PERCENT CHANCE ACROSS THE WEST. AS THE TROUGH/COLD FRONT ADVANCES SLOWLY EAST TONIGHT...THE RAIN CHANCES WILL ESSENTIALLY END FROM WEST TO EAST AND EXPECT THE ENTIRE AREA TO BE DRY BY 12Z TUESDAY. AFTER TONIGHT...SOME SMALL RAIN CHANCES RETURN TO THE SOUTHEAST PARTS OF THE FORECAST AREA WEDNESDAY NIGHT. THE MEAN LONG WAVE TROUGH WILL REMAIN OVER THE CENTRAL PART OF THE COUNTRY THANKS TO AN UPPER LEVEL LOW NEAR HUDSON BAY AND ANOTHER SHORT WAVE TROUGH COMING OUT OF THE SOUTHWEST PART OF THE COUNTRY. THIS SHORT WAVE TROUGH IS EXPECTED TO PASS OFF JUST TO THE SOUTHEAST OF THE AREA ACROSS ILLINOIS WITH THE SURFACE LOW NEAR THE OHIO RIVER. THE DEFORMATION AREA OF RAIN ON THE NORTHWEST SIDE OF THE LOW COULD EXTEND BACK INTO THE AREA AND WILL HAVE THE SMALL RAIN CHANCES FOR THIS POSSIBILITY. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 328 PM CDT MON MAY 12 2014 THE LONG WAVE TROUGH WILL THEN MOVE SLOWLY NORTHEAST AS SEVERAL WEAKER SHORT WAVE TROUGHS COME INTO THE LONG WAVE TROUGH ON THE NORTHWEST FLOW FROM SOUTHERN AND WESTERN CANADA. THIS WILL PROVIDE JUST ENOUGH FORCING FOR SOME SMALL RAIN CHANCES THURSDAY THROUGH FRIDAY...SATURDAY AND AGAIN MONDAY. TEMPERATURES WILL STILL BE COOL TO CLOSE OUT THE WEEK BUT THEN START TO MODERATE FOR THE WEEKEND INTO EARLY NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1247 PM CDT MON MAY 12 2014 MUCH OF THE AREA TO GET A BREAK FROM THE SHRA/TSRA DURING THE EARLY AFTERNOON HOURS. A SFC TROUGH/FRONT WILL SLIDE EAST INTO AND ACROSS THE TAF SITES LATER THIS AFTERNOON/EARLY THIS EVENING. ONE MORE ROUND OF SHRA/TSRA EXPECTED TO DEVELOP ALONG/AHEAD OF THIS BOUNDARY AND IMPACT THE TAF SITES MAINLY IN THE 20Z-01Z PERIOD THIS AFTERNOON/EARLY THIS EVENING. SHRA/TSRA WITH MVFR/IFR CIGS/VSBYS TO BE MORE OF AN IMPACT AT KLSE VS. KRST...CARRIED A PERIOD OF TEMPO TSRA AT KLSE AND ONLY VCTS/CB AT KRST DURING THIS TIME-FRAME. ONCE THE TROUGH/FRONT PUSHES THRU...CONCERN SHIFTS TO THE ABUNDANT LOW LEVEL MOISTURE AND IFR/LIFR CIGS BEHIND IT WHICH WILL SPREAD ACROSS THE TAF SITES FOR MUCH OF TONIGHT INTO TUE MORNING. A PERIOD OF MVFR VSBYS IN BR EXPECTED AS WELL. EVENTUALLY THE BRISK NORTHWEST WINDS/LOW LEVEL FLOW WILL SPREAD/MIX SOME DRIER BOUNDARY LAYER AIR INTO THE AREA WITH VSBYS EXPECTED TO IMPROVE TO VFR AND CIGS TO IMPROVE TO MVFR THRU TUE MORNING. && .HYDROLOGY... ISSUED AT 328 PM CDT MON MAY 12 2014 AS THE STORMS COME IN ACROSS THE EASTERN SECTIONS TONIGHT...THE TALL SKINNY CAPE PROFILE SHOULD LEAD TO MORE RAIN DROP PRODUCTION INSTEAD OF HAIL. THIS CAN ALSO BE SEEN IN THE WARM CLOUD DEPTHS...WHICH THE 12.18Z NAM CONTINUES TO SHOW TO BE AROUND 3500 METERS. WHILE THE QPF THAT FALLS THROUGH THE REST OF THE AFTERNOON AND EVENING MAY BE AN INCH OR LESS...IT WILL BE FALLING ON GROUND THAT RECEIVED UP TO 1.5 INCHES SUNDAY NIGHT. WITH THE GROUND BEING SATURATED FROM THESE PREVIOUS RAINS...THE ADDITIONAL RAIN COULD STILL PRODUCE SOME LOCALIZED FLOODING PROBLEMS AND WILL CONTINUE THE FLASH FLOOD WATCH FOR ALL BUT THE FAR NORTHWEST SECTION OF THE FORECAST AREA. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FLASH FLOOD WATCH UNTIL 1 AM CDT TUESDAY FOR WIZ017-029-032>034- 041>044-053>055-061. MN...FLASH FLOOD WATCH UNTIL 1 AM CDT TUESDAY FOR MNZ088-095-096. IA...FLASH FLOOD WATCH UNTIL 1 AM CDT TUESDAY FOR IAZ009>011-018-019- 029-030. && $$ SHORT TERM...04 LONG TERM...04 AVIATION.....RRS HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
310 PM CDT MON MAY 12 2014 .REST OF THIS AFTERNOON AND TONIGHT - CONFIDENCE...MEDIUM ELONGATED LOW PRESSURE FROM ERN IA INTO WRN WI AREA WILL LIFT TO NORTH OF LAKE SUPERIOR. PLENTY OF MOIST AND UNSTABLE AIR RETURNING. SPC MESO CHARTS ARE SHOWING SOME VERY IMPRESSIVE PARAMETERS ESPECIALLY INTO SC WI. SO HEIGHTENED CONCERN FOR ALL FORMS OF SEVERE WEATHER AND THIS INCLUDES THE POTENTIAL FOR TORNADOGENESIS. OUTFLOW BOUNDARY SETTING UP FAR SRN WI WILL ONLY ADD TO THAT CONCERN. ISOLATED STORMS ALREADY FIRING ACRS NRN IL. 0-6KM SHEAR AND 0-1KM SHEAR GETS A LITTLE BETTER MOVING FROM IL INTO WI. LATEST HRRR SHOWING IA DEVELOPMENT SPREADS ACRS SRN WI LATE AFTN/ERLY EVE WITH LESS CONFIDENCE LATER IN THE NIGHT WITH THE APPROACH OF THE COLD FRONT. AIRMASS MAY BE PRETTY WORKED OVER BY THEN. TWO AREAS RECEIVED DECENT RAINS...ONE BEING IN THE NW CWA NEAR THE DELLS AND THE OTHER IN THE SE. WILL HOLD OFF ON FLASH FLOOD WATCH AS CONVECTION SHOULD BE ON THE MOVE BUT ANY TRAINING ALONG THE OUTFLOW COULD CAUSE PROBLEMS. .TUESDAY - CONFIDENCE...MEDIUM LOW PRESSURE WILL CONTINUE TO LIFT NNE INTO CANADA WITH COLD FRONT SHIFTING TO THE EAST. EXPECT SOME LINGERING SHRA IN ERN CWA DURG THE MRNG HRS. UPPER FLOW IS STILL SOUTHWEST SO THIS WILL LIKELY CARRY SOME WEAK DISTURBANCES ALONG AND AHEAD OF 850 FRONT TO MAINTAIN RAIN CHANCES IN THE MORNING ACROSS THE SE 1/2. THEN WITH THE COLD ADVECTION ON THE BACK SIDE OF THIS SYSTEM WE CAN TAKE ABOUT 10-15 DEGREES OFF THE 925 TEMPS. SO TURNING COOLER...LESS HUMID AND LIKELY A GOOD DEAL OF CLOUD COVER TO CONTEND WITH. LLVL RH PROGS AND MOS SKY COVER SUGGEST THIS... ESPECIALLY WITH THE INCOMING LOW LEVEL COOL POOL AND MID LEVEL TROUGH AXIS STILL TO THE WEST. .TUESDAY NIGHT - CONFIDENCE...HIGH A QUIET PERIOD AS DRY...COOLER AIR SETTLES INTO SOUTHERN WI. 85H TEMPS FALL TO AROUND 0C OVERNIGHT. BOUNDARY LAYER MIXING WILL KEEP THE LOWEST LEVELS STIRRED ENOUGH TO KEEP OVERNIGHT TEMPS MOSTLY 40 TO 45F. .WEDNESDAY THROUGH THURSDAY...FORECAST CONFIDENCE - MEDIUM. UNCERTAINTY CREEPS IN LATER WEDNESDAY THROUGH THURSDAY FOR PRECIP THREAT. SHORT TERM GUIDANCE IN GENERAL AGREEMENT ON CYCLOGENESIS OCCURRING OVER SOUTHERN PLAINS LATER WEDNESDAY WITH STRENGTHENING LOW PRESSURE TRACKING NORTHEAST THROUGH THE TN AND OH VALLEYS. MID- LEVEL CIRCULATION TRACKING ALONG BAROCLINIC ZONE OVER IL MAY BRING SOME -RA TO SOUTHEAST WI WED NGT INTO THU. HOWEVER LATEST CANADIAN A LITTLE FARTHER EAST WITH THE BAROCLINIC ZONE. DUE TO UNCERTAINTY...WL BUMP UP POPS TO HIGH CHANCE IN MY SOUTHEAST...DROPPING OFF FAIRLY QUICKLY TO LOW/SLIGHT CHANCE AS EXPECT A SHARP CUTOFF ACROSS SOUTHEAST WI. LOW LEVEL THERMAL PROFILE FAVORS RAIN...HOWEVER IF SLIGHT ADDITIONAL COOLING WERE TO TAKE PLACE...THEN COULD BE SOME SNOW MIXED IN WITH THE RAIN AT TIMES. .THURSDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE - MEDIUM. LOW MOVING NORTH FROM THE OH VALLEY ACROSS THE GTLAKES THU AND THU NIGHT WILL TRANSITION TO STATIONARY UPPER LOW OVER THE REGION FOR THE END OF THE WEEK...ON INTO THE WEEKEND. THIS WILL RESULT IN CONTINUED PERIOD OF COLD NORTHWEST WINDS REINFORCING CHILLY AIR OVER SRN WI INTO SATURDAY. THE UPPER LOW FINALLY STARTS TO BREAK DOWN OVER THE WEEKEND...WHICH WOULD ALLOW MILDER AIR TO RETURN TO THE AREA BEGINNING SUNDAY. OVERNIGHT LOWS EXPECTED TO DIP INTO THE 30S SEVERAL NIGHTS. WL NEED TO WATCH NIGHT TIME CLOUD COVER AND THINK ABOUT FROST POTENTIAL FOR THURSDAY NIGHT AND FRIDAY NIGHT. && .AVIATION/00Z TAFS/...MAIN SHORT TERM CONCERN WILL BE CONVECTION INTO THE EVENING HOURS. NEXT WAVE OF STORMS APPROACHING FROM IOWA WILL ARRIVE LATER THIS AFTN/EVE. ISOLATED STORMS FIRING VCNTY OUTFLOW BOUNDARY IN NRN IL. THESE MAY BECOME SVR. STORMS IN IA MOVG INTO WI THIS EVE MAY BE SVR AS WELL. LATEST HRRR SUGGESTS LESS ACTIVITY LATER IN THE NIGHT AS AIRMASS STABILIZES ONCE THIS SURGE PASSES. HOWEVER WILL STILL KEEP TSRA CHANCES DUE TO APPROACHING UPPER JET DYNAMICS AND SURFACE COLD FRONT DRAWING CLOSER. DENSE FOG CONCERNS ARE NORTH OF TAF SITES. && .MARINE...WILL RETAIN DENSE FOG ADVISORY THROUGH LATER IN THE NIGHT FOR PORT WASHINGTON TO SHEBOYGAN AS THAT AREA ENTRENCHED IN THE FOGGY CONDITIONS WITH COOL FLOW OFF THE LAKE. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...DENSE FOG ADVY LMZ643 TIL 03Z/13. && $$ TONIGHT/TUESDAY AND AVIATION/MARINE...PC TUESDAY NIGHT THROUGH MONDAY...MBK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1119 AM CDT MON MAY 12 2014 .UPDATE...LOTS GOING ON FROM DENSE FOG IN PARTS OF EC WI AND OVER THE LAKE...TO LINE OF STORMS RACING EAST THROUGH SRN WI. SPC MESO PAGE SHOWS DECENT AIRMASS IN PLACE FOR THE STORMS IN NRN IL TO FEED OFF. LOTS OF CLOUDS UPSTREAM SO FURTHER DESTABILIZATION LATER WILL HINGE ON GETTING THINGS CLEARED OFF. BUT BETTER DYNAMICS AND COLD FRONT ARRIVES TONIGHT. LATEST HRRR DOES SHOW MORE CONVECTION ARRIVING TONIGHT WITH SLIGHT RISK STILL IN PLACE. PC && .AVIATION/18Z TAFS/...MAIN SHORT TERM CONCERN WILL BE ONGOING LINE OF STORMS SWEEPING THROUGH SRN WI. DENSE FOG CONCERNS ARE NORTH OF TAF SITES. WILL CLEAR CURRENT STORMS OUT OF THE FAR EAST BY 20Z OR SO THEN WAIT FOR POSSIBLE REDEVELOPMENT THIS EVENING AND OVERNIGHT AS COLD FRONT AND BETTER DYNAMICS GET A BIT CLOSER. PC && .PREV DISCUSSION... /ISSUED 340 AM CDT MON MAY 12 2014/ TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH THE UPPER LEVEL RIDGE OVER THE WESTERN GREAT LAKES AHEAD OF THE STRONG WESTERN TROUGH ACROSS THE ROCKIES WILL PUSH INTO THE EASTERN GREAT LAKES BY SUNRISE TUESDAY. THE 105 KNOT JET MAX WAS LIFTING NORTHEAST FROM THE BASE OF THE TROUGH THIS MORNING AND WILL REACH WESTERN MINNESOTA THIS EVENING STRENGTHENING TO 115 KNOTS. WEAK TO MODERATE UPPER DIVERGENCE CONTINUES ACROSS SOUTHERN WISCONSIN TODAY AND TONIGHT. A 700 MB WIND MAX OF 40 KNOTS PUSHES INTO CENTRAL WISCONSIN BY SUNRISE. A SECOND STRONGER 700 MB WIND MAX OF 55 KNOTS ASSOCIATED WITH THE MAIN TROUGH REACHES WESTERN WISCONSIN THIS EVENING AND PUSHES EAST EARLY TUESDAY MORNING. AT 850 MB A 50 KNOT LOW LEVEL JET ACROSS EASTERN KANSAS INTO SOUTHERN IOWA PUSHES INTO SOUTHWEST WISCONSIN JUST AFTER SUNRISE BEFORE WEAKENING AND LIFTING NORTH LATER THIS MORNING. A 45 KNOT 850 MB JET MAX ALSO MOVES ACROSS SOUTHERN WISCONSIN LATE TONIGHT. 700 MB MODERATE UPWARD MOTION OCCURS EARLY THIS MORNING WITH THE APPROACHING LOW LEVEL JET MAX AND 850 MB MOISTURE CONVERGENCE AS THE WARM FRONT ADVANCES NORTH. THEREFORE EXPECT AN AREA OF THUNDERSTORMS TO ROLL THROUGH THIS MORNING. SOME MAY PRODUCE BRIEF HEAVY RAINS. 850/700 MB DEW POINTS INCREASE THIS MORNING WITH 850 MB DEWPOINTS AROUND 11 TO 12 CELSIUS THIS EVENING UNTIL THE CONVECTION OCCURS. BY AFTERNOON SOUTH CENTRAL AND SOUTHEAST WISCONSIN WILL BE IN THE WARM SECTOR. UNTIL THEN EAST TO SOUTHEAST WINDS WILL KEEP THE LAKESHORE AREAS COOL WITH SOME FOG POSSIBLE AS THE AIRMASS DEW POINTS RISE INTO IN THE MID 60S...WITH SOME UPPER 60S POSSIBLE. INLAND AREAS SHOULD REACH 80...BUT AREAS ALONG THE LAKE...ESPECIALLY TOWARD SHEBOYGAN SHOULD STAY COOLER WITH SOUTH/SOUTHEAST FLOW MUCH OF THE DAY. WITH MODELS PRODUCING SOME PRECIPITATION TODAY IN THE WARM SECTOR...THE AMOUNT OF MODEL CAPE IS LIKELY LESS THAN WHAT WILL OCCUR. THERE WILL BE A CHANCE OF THUNDERSTORMS...BUT LIFTING MECHANISM DIFFICULT FOR TIMING DUE TO LIKELY MORNING CONVECTION AND BOUNDARIES. FOCUS FOR SEVERE WILL LIKELY BE IN AREAS WEST OF MADISON EARLY THIS EVENING AHEAD OF THE ADVANCING COLD FRONT. HELICITY VALUES DO RISE TO NEAR 200 WITH SOME LOW LEVEL VEERING. THEREFORE THERE WILL BE A TORNADO THREAT. COLD FRONT THEN MOVES ACROSS SOUTHERN WISCONSIN TONIGHT WITH A LINE OF THUNDERSTORMS EXPECTED. CAPE VALUES WILL DECREASE AS THE STORMS MOVE EAST DUE TO DIURNAL COOLING. LOCAL SEVERE PROBABILITY CWASP VALUES INCREASE TO 75 TO 80 PCT INTO PORTIONS OF SOUTH CENTRAL WISCONSIN THIS AFTERNOON AND EARLY EVENING WITH 70 PCT EAST. TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE...MEDIUM THE SURFACE COLD FRONT SHOULD BE THROUGH BY DAYBREAK TUESDAY...WITH A FEW SHOWERS/STORMS POSSIBLY LINGERING EAST IN THE MORNING. IT SHOULD BE DRY THEN THE REST OF THE DAY WITH MUCH COOLER TEMPS BEHIND THE DEPARTING FRONT. DRY WEATHER WILL THEN PERSIST TUESDAY NIGHT THROUGH AT LEAST WEDNESDAY MORNING. LOW PRESSURE PASSING BY WELL TO THE SOUTHEAST MAY BRING SOME LIGHT RAIN THEN LATE WEDNESDAY AFTERNOON INTO THE NIGHT...MAINLY ACROSS THE SOUTHEAST. EVEN COOLER TEMPS ARE LIKELY WEDNESDAY...STRUGGLING INTO THE UPPER 50S MOST PLACES. THURSDAY THROUGH SUNDAY...FORECAST CONFIDENCE...MEDIUM NORTHWEST FLOW WILL BRING CONTINUED BELOW NORMAL TEMPERATURES FOR THURSDAY THROUGH THE WEEKEND. A SERIES OF SHORTWAVES WILL ALSO BRING A CHANCE FOR SHOWERS AT TIMES. AVIATION/12Z TAFS/... STILL EXPECTING SOME MVFR CIGS/VSBYS AHEAD OF A WARM FRONT. THE WARM FRONT WILL LIFT NORTH THIS MORNING...BUT SOME SOUTHEAST FLOW MAY STILL AFFECT THE LAKESHORE AREAS OF LAKE MICHIGAN WITH MVFR VSBYS IN FOG/HAZE. EXPECT AN AREA OF THUNDERSTORMS THIS MORNING WITH THE WARM FRONT AND A CHANCE OF THUNDERSTORMS THIS AFTERNOON. THEN MORE THUNDERSTORMS LIKELY WITH A COLD FRONT TONIGHT. SOME OF THE STORMS COULD BE SEVERE...ESPECIALLY THIS AFTERNOON AND EVENING. IFR CONDITIONS IN ANY STORMS. MARINE... LIGHT EAST TO SOUTHEAST WINDS THIS MORNING AHEAD OF AN ADVANCING WARM FRONT WILL BRING AREAS OF FOG. THE WARM FRONT WILL MOVE NORTH LATER TODAY BUT A WEAK ONSHORE FLOW WILL LIKELY CONTINUE NORTH OF MILWAUKEE. LOOK FOR PERIODS OF THUNDERSTORMS TODAY AND TONIGHT. SOME MAY BE SEVERE ESPECIALLY TONIGHT. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR WIZ052. LM...DENSE FOG ADVISORY UNTIL 2 PM CDT THIS AFTERNOON FOR LMZ643. && $$ TODAY/TONIGHT AND AVIATION/MARINE...HENTZ TUESDAY THROUGH SUNDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1133 PM CDT SUN MAY 11 2014 .UPDATE... ISSUED AT 938 PM CDT SUN MAY 11 2014 WITH RAINFALL RATES OF 1 TO 2 INCHES PER HOUR POSSIBLE OVERNIGHT AND GRB ADDING A FLASH FLOOD WATCH FOR SOME OF THEIR COUNTIES IN NORTH CENTRAL WISCONSIN...HAVE DECIDED TO CHANGE OVER THE FLOOD WATCH TO A FLASH FLOOD WATCH AND EXTEND IT THROUGH 6Z TUESDAY WHEN THE COLD FRONT SHOULD BE CLEAR OF THE REGION. TIMING OF THE COMPLEX MAKING IT INTO NORTHEAST IOWA STILL LOOKS GOOD FOR AROUND MIDNIGHT NEAR THE I-35 CORRIDOR...IT IS JUST A MATTER OF HOW INTENSE IT WILL BE AS IT GETS IN. UPDATE ISSUED AT 855 PM CDT SUN MAY 11 2014 THE MAIN FOCUS WITH THE FORECAST IS WITH THE SEVERE WEATHER POTENTIAL OVERNIGHT. CURRENT SURFACE ANALYSIS SHOWS A LOW PRESSURE SYSTEM CENTERED NEAR OMAHA WHERE A BOWING COMPLEX HAS EMERGED FROM A LONG TRACK HP SUPERCELL THAT TRACKED ACROSS SOUTHEAST NEBRASKA THIS AFTERNOON. THE MAIN SURFACE WARM FRONT APPEARS TO EXTEND EAST FROM OMAHA ACROSS SOUTHERN IOWA WITH AN INVERTED TROUGH EXTENDING NORTH FROM THE LOW INTO SOUTHWEST MINNESOTA. ANOTHER DEW POINT GRADIENT EXISTS ALONG THE MINNESOTA/IOWA BORDER WHERE DEW POINTS GO FROM THE MID 50S IN SOUTHEAST MINNESOTA TO THE LOW 60S IN NORTHEAST IOWA. 12.00Z RAP ANALYSIS SUGGESTS THAT THERE STILL IS QUITE A BIT OF INSTABILITY AHEAD OF THIS COMPLEX RUNNING EAST ACROSS IOWA WITH 0-3KM MUCAPE AROUND 2000 J/KG FROM DES MOINES EAST AND AROUND 1000 J/KG RUNNING ALONG THE MINNESOTA/IOWA BORDER. SURFACE BASED CAPE IS STARTING TO DECREASE...BUT IS STILL FAIRLY DECENT OUT AHEAD OF THE BOW AT 2000 J/KG. SHORT TERM GUIDANCE HAS BEEN VERY CONSISTENT THIS AFTERNOON/EARLY EVENING WITH SHOWING AN INITIAL BAND OF MAINLY WEAK CONVECTION DEVELOPING ALONG THE LEADING EDGE OF THE 925-850MB MOISTURE TRANSPORT AND LIFTING NORTH THROUGH THE EVENING. THE MAIN QUESTION IS WITH WHERE THE COMPLEX IN WESTERN IOWA WILL TRACK. WITH THE 925MB JET AND MOISTURE TRANSPORT INCREASING AND LIFTING NORTH OVERNIGHT...THE SUPPORT IS THERE FOR ANY CONVECTION TO CONTINUE TO TRACK EAST-NORTHEAST. FORWARD PROPAGATING CORFIDI VECTORS AND 0-3KM SHEAR IS ALL POINTING FROM THE SOUTHWEST TO THE NORTHEAST AND THAT HAS BEEN BACKED BY THE INITIAL TRENDS WITH THE BOW. CURRENT EXTRAPOLATION AND MESO-MODELS WOULD SAY THAT THE LEADING EDGE OF THIS COMPLEX WOULD BE INTO THE CHARLES CITY IOWA AREA AROUND OR SHORTLY AFTER MIDNIGHT...TO THE MISSISSIPPI RIVER IN NE IA/SW WI AROUND 3AM...AND ON INTO SOUTH CENTRAL WISCONSIN BY 5AM. THIS LINE OF STORMS HAS ALREADY PRODUCED 80MPH WIND GUSTS AT OMAHA...BUT DO NOT EXPECT IT TO BE AT THAT STRENGTH...BUT STILL POSSIBLY SEVERE...AS IT GETS INTO THE REGION. AM CONSIDERING CHANGING THE FLOOD WATCH TO A FLASH FLOOD WATCH SINCE THERE APPEARS TO BE A CHANCE THAT THIS COMPLEX SLOWS DOWN AND PRODUCES SOME HEAVY RAINFALL OVER A SHORT PERIOD OVERNIGHT THAT IS TIED MORE TO CONVECTION THAN A LONG LIVED MODERATE RAIN. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 325 PM CDT SUN MAY 11 2014 FOCUS OF THE FORECAST IS ON RAIN THROUGH TUESDAY. REGIONAL RADARS SHOW A CONVECTIVE COMPLEX HAS SURVIVED FROM THE OVERNIGHT HOURS AND CONTINUES TO TRANSLATE ACROSS SOUTHERN IOWA. THAT HAS EFFECTIVELY PINNED THE WARM FRONT WELL SOUTH OF THE AREA ALONG THE IOWA/MISSOURI BORDER. THIS HAS ALSO PINNED MOST OF THE CAPE TO THE SOUTH WITH THE 19Z MU CAPE SHOWING LESS THAN 500 J/KG ACROSS THE AREA. THE CONCERN BECOMES WHAT HAPPENS THIS EVENING AS THE COMPLEX CONTINUES TO MOVE EAST AND IF THE WARM FRONT CAN MAKE A MOVE NORTH. THE 11.17Z HRRR SUGGESTS THAT THE WARM FRONT WILL START TO PUSH NORTH THIS EVENING BUT MAY STILL BE ONLY ABOUT AS FAR NORTH AS THE INTERSTATE 80 CORRIDOR BY 03Z. THE WARM FRONT COULD THEN GET PUSHED NORTHEAST THROUGH THE REST OF THE EVENING AND NIGHT AS A STRONG SHORT WAVE TROUGH MOVES NORTHEAST ACROSS THE REGION. THE 11.12Z NAM DOES SUGGEST BETWEEN 1000-1500 J/KG OF ML CAPE WILL BE IN PLACE ALONG AND NEAR THE WARM FRONT...BUT IF THE WARM FRONT GETS PUSHED NORTHEAST...THIS CAPE MAY JUST CLIP THE SOUTHEAST PORTIONS OF THE AREA. HOWEVER...IF THIS SCENARIO DOES NOT PLAY OUT AND THE CAPE IS FARTHER WEST...THERE WILL STILL BE A SEVERE THREAT. THE 0-6KM SHEAR THIS EVENING SHOULD INCREASE TO A RANGE OF 30 TO 50 KNOTS THIS EVENING THEN TO AROUND 60 KNOTS FOR THE OVERNIGHT HOURS. THE NAM REMAINS CONSISTENT SHOWING 200-300 M2/S2 OF HELICITY OVER THE AREA IN THE 0-3KM LAYER WITH THE BULK OF THE RESIDING THE 0-1KM LAYER. SO IF THE WARM FRONT CAN GET INTO THE AREA...THERE WOULD STILL BE A THREAT FOR AN ISOLATED TORNADO...BUT CONFIDENCE ON THE POSITION OF THE WARM FRONT IS NOT VERY HIGH. CONFIDENCE IS HIGH THAT IT WILL RAIN TONIGHT. THE MODELS HAVE BEEN CONVERGING TOWARD THE SCENARIO THAT AS THE SHORT WAVE TROUGH COMES OUT OF THE CENTRAL PLAINS AND MOVES NORTHEAST OVER THE REGION TONIGHT THAT CONVECTION WILL FORM ALONG AN INVERTED TROUGH. THIS TROUGH CURRENTLY EXTENDS FROM THE SOUTHWEST KANSAS ACROSS WESTERN IOWA INTO WESTERN WISCONSIN. AS THE SHORT WAVE TROUGH COMES OUT...MODERATE PV ADVECTION IN THE 500-300 MB LAYER IS EXPECTED TO OCCUR. IN THE LOW LEVELS...THE WARM AIR ADVECTION WILL INCREASE AHEAD OF THE WAVE WITH 5 TO 7 UBAR/S OF UP GLIDE ON THE 300K ISENTROPIC SURFACE WITH THE MOISTURE TRANSPORT ON THIS LEVEL RIGHT INTO THE AREA. EXPECT TO SEE THE LINE OF CONVECTION DEVELOP IN RESPONSE TO THIS WAVE FROM SOUTHERN MINNESOTA INTO KANSAS AND THEN MOVE NORTHEAST ACROSS THE AREA THROUGH THE NIGHT. ONCE THE SHORT WAVE TROUGH MOVES PAST...THE FORCING WILL SHIFT BACK TO THE WEST AGAIN AHEAD OF THE MAIN LONG WAVE TROUGH AND THE EMBEDDED SHORT WAVE TROUGH. THIS IS EXPECTED TO MAKE THE MAIN SURFACE LOW MOVE FROM KANSAS INTO MINNESOTA OR WISCONSIN DURING THE DAY MONDAY WITH THE COLD FRONT ADVANCING EAST INTO THE AREA. ANOTHER ROUND OF VERY SIMILAR ISENTROPIC UP GLIDE AND MOISTURE TRANSPORT IS EXPECTED ON THE 300K SURFACE FOR CONTINUED SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONT. EVERYTHING THEN STARTS TO TRANSLATE EAST FOR MONDAY NIGHT WITH THE RAIN CHANCES ENDING FROM WEST TO EAST THROUGH TUESDAY MORNING. .LONG TERM...(WEDNESDAY THROUGH SUNDAY) ISSUED AT 325 PM CDT SUN MAY 11 2014 WILL CARRY SOME SMALL RAIN CHANCES FOR WEDNESDAY THROUGH FRIDAY AND THEN SOME ON AND OFF CHANCES OVER THE WEEKEND. ONCE THE SYSTEM FROM EARLY IN THE WEEK MOVES PAST...THE LONG WAVE TROUGH LOOKS TO REMAIN OVER THE CENTRAL PART OF THE COUNTRY WITH A NORTHWEST FLOW FROM NORTHWEST CANADA. THIS SHOULD ALLOW SEVERAL WEAK SHORT WAVE TROUGHS TO ROTATE THROUGH THE LONG WAVE TROUGH TO SUPPORT THE RAIN CHANCES. THIS FLOW WILL ALSO HELP TO KEEP TEMPERATURES BELOW NORMAL WITH HIGHS IN THE 50S TO END THE WEEK AND THEN CREEPING BACK INTO THE 60S FOR THE WEEKEND. OVERNIGHT LOWS WILL BE IN THE 30S AND MAY HAVE TO DEAL WITH SOME FROST HEADLINES TOWARD THE END OF THE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1133 PM CDT SUN MAY 11 2014 A BAND OF SHOWERS AND THUNDERSTORMS ARE CURRENTLY MOVING ACROSS SOUTHEAST MINNESOTA AND NORTH CENTRAL IOWA AND WILL CONTINUE TO TRACK TO THE EAST THROUGH THE EARLY MORNING HOURS. VISIBILITY HAS DROPPED TO 1SM WITH SOME OF THE STRONGER THUNDERSTORMS...SO HAVE KEPT THAT AS THE TEMPO GROUP THROUGH 10Z AT LSE AND 8Z AT RST. IT APPEARS THAT THIS RAIN WILL TRACK EAST WITH A DRY PERIOD POSSIBLE THROUGH THE REST OF THE MORNING. ANOTHER ROUND OF CONVECTION WILL DEVELOP IN THE AFTERNOON...BUT CONFIDENCE IS NOT VERY HIGH AT THIS POINT WITH HOW IT WILL PAN OUT AND WHEN IT WILL COME THROUGH THE TAF SITES. && .HYDROLOGY... ISSUED AT 325 PM CDT SUN MAY 11 2014 RAINFALL FROM THIS SYSTEM THROUGH MONDAY SHOULD AVERAGE AROUND 2 INCHES FOR MUCH OF THE FORECAST AREA WITH LOCALIZED HIGHER AMOUNTS EXPECTED. MANY OF THE RIVERS REMAIN HIGH FROM RECENT RUN OFFS AND THE LATEST FORECASTS FROM THE RFC INDICATED WITHIN BANK RISES FOR MANY OF THE TRIBUTARIES WITH RENEWED FLOODING POSSIBLE AT SOME SPOTS ALONG THE MISSISSIPPI. IF THE RAINFALL ENDS UP BEING HIGHER THAN THE QPF USED BY THE RFC...WHICH IS HIGH PROBABILITY...SOME THE TRIBUTARIES COULD ALSO GO TO FLOOD. BASED ON THIS...HAVE OPTED TO ISSUE A FLOOD WATCH FOR THE ENTIRE AREA FOR TONIGHT AND MONDAY. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FLASH FLOOD WATCH THROUGH LATE MONDAY NIGHT FOR WIZ017-029- 032>034-041>044-053>055-061. MN...FLASH FLOOD WATCH THROUGH LATE MONDAY NIGHT FOR MNZ079-086>088- 094>096. IA...FLASH FLOOD WATCH THROUGH LATE MONDAY NIGHT FOR IAZ008>011-018- 019-029-030. && $$ UPDATE...HALBACH SHORT TERM...04 LONG TERM...04 AVIATION...HALBACH HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS ALBANY NY
430 AM EDT WED MAY 14 2014 .SYNOPSIS... A BACKDOOR COLD FRONT IS SITUATED SOUTH AND WEST OF THE REGION AND WILL REMAIN NEARLY STATIONARY THROUGHOUT THE DAY TODAY. THIS FRONT WILL BE THE FOCUS FOR SOME SHOWERS AND THUNDERSTORMS FOR THE WESTERN PORTION OF THE REGION. BY TONIGHT INTO TOMORROW...THIS FRONT WILL START TO DISSIPATE...AS A WARMER AND MORE HUMID AIR MASS MOVES INTO THE AREA. A SLOW MOVING COLD FRONT FROM THE WEST WILL BRING A WIDESPREAD SOAKING RAIN TO THE ENTIRE REGION FOR LATE THURSDAY NIGHT THROUGH SATURDAY MORNING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 430 AM EDT...A BACK DOOR COLD FRONTAL BOUNDARY IS DRAPED ACROSS CENTRAL NY SOUTHWARD THROUGH CENTRAL PA AND TOWARDS THE MID ATLANTIC REGION. THERE IS A NOTICEABLE CHANGE BETWEEN MILDER AND MORE HUMID AIR OVER WESTERN/CENTRAL NY AS COMPARED TO THE AIR MASS OVER MUCH OF OUR AREA...AS STABLE MARINE AIR HAS BEEN IN PLACE OVER OUR REGION. THIS BOUNDARY ALLOWED FOR CONVECTION TO DEVELOP DURING TUESDAY EVENING...AND THIS COMPLEX OF SHOWERS/THUNDERSTORMS GRADUALLY WORKED EASTWARD INTO THE MORE STABLE AIR. ALTHOUGH WEAKENING...AN AREA OF SHOWERS AND THUNDERSTORMS IS CURRENTLY STILL ONGOING OVER THE SCHOHARIE AND MOHAWK VALLEY...EASTERN CATSKILLS...CAPITAL REGION...AND SARATOGA AREA. THE 05Z 3KM HRRR GUIDANCE SUGGESTS THIS ACTIVITY WILL CONTINUE TO WEAKEN AS IT LIFTS NORTHEAST...AND MOST OF THE REGION WILL BE DRY BY ABOUT 8 AM. BEFORE THEN...SOME CONTINUED LIGHT RAIN WITH EMBEDDED THUNDER WILL BE POSSIBLE OVER BASICALLY THE ENTIRE REGION EXCEPT FOR THE MID HUDSON VALLEY AND NW CT. ALTHOUGH THERE WILL BE CLOUDS TO START THE DAY...THERE SHOULD BE SOME BREAKS BY THE MID TO LATE MORNING. THE BOUNDARY WILL REMAIN SITUATED WEST OF OUR REGION...AND WE WILL CONTINUE TO HAVE ONE MORE DAY WITH LOW DEWPOINTS /MAINLY IN THE 40S/. SOME RENEWED SHOWER/THUNDERSTORM ACTIVITY MAY GET GOING DURING DAYTIME HEATING ACROSS CENTRAL NY...AND IT/S POSSIBLE OUR FAR WESTERN AREAS MAY GET BRUSHED ONCE AGAIN FROM THIS DEVELOPMENT. OTHERWISE...A DRY DAY IS EXPECTED FOR MUCH OF THE AREA. ALTHOUGH IT/S VERY WARM ALOFT /850 HPA TEMPS AROUND 15 DEGREES C/...MODEL SOUNDINGS SUGGEST WE WILL ONLY MIX TO ABOUT 925-950 HPA. STILL...THIS WILL EQUATE TO HIGHS REACHING THE MID TO UPPER 70S FOR VALLEY AREAS /UPPER 60S TO LOW 70S FOR THE HIGH TERRAIN/...WHICH IS STILL ABOVE NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... ANY SHOWERS/THUNDERSTORMS OVER FAR WESTERN AREAS SHOULD START TO DISSIPATE IN THE EVENING DUE TO THE LOSS OF DAYTIME HEATING. OTHERWISE... WITH THE LOW LEVEL FLOW EXPECTED TO CONTINUE TO BE OUT OF THE SOUTH...THE BACKDOOR FRONT WILL START TO BECOME DIFFUSE AND EVENTUALLY DISSIPATE TONIGHT. THIS WILL ALLOW MORE HUMID AIR TO MOVE INTO OUR REGION. ALONG WITH THE PERSISTENTLY HUMID SOUTHERLY FLOW WILL BE MORE CLOUDS...AS SOME STRATUS MAY MAKE ITS WAY INTO THE REGION OFF THE CHILLY ATLANTIC. IT/S POSSIBLE THAT SOME LIGHT RAIN SHOWERS OR DRIZZLE MAY ALSO OCCUR ACROSS SOUTHERN AREAS DUE TO MOIST FLOW...ESP IN UPSLOPE FAVORED LOCATIONS. OVERNIGHT LOWS TONIGHT WILL BE IN THE 50S TO NEAR 60. OUR REGION WILL BE IN A WARM SECTOR ON THURSDAY...AS A SLOW MOVING FRONTAL SYSTEM WILL BE OVER THE OHIO VALLEY...AND A STRONG RIDGE WILL BE JUST DOWNSTREAM OF OUR AREA OVER THE WESTERN ATLANTIC. IT SHOULD BE MAINLY DRY ON THURSDAY...ALTHOUGH DIFFERENTIAL HEATING BOUNDARIES...MAINLY ALONG THE HIGH TERRAIN...MAY ALLOW AN AFTN OR EVENING SHOWER OR THUNDERSTORM TO DEVELOP. THE CONTINUED SOUTHERLY FLOW MAY STILL KEEP A LOT OF CLOUDS AROUND...BUT IT STILL LOOKS TO BE ANOTHER WARM DAY...WITH MAX TEMPS WELL INTO THE 70S TO NEAR 80. BY THURSDAY NIGHT...THE FRONTAL SYSTEM TO OUR WEST WILL START TO APPROACH. IT WILL BE MOVING RATHER SLOWLY...AS WEAK WAVES OF LOW PRESSURE DEVELOP AND RIDE UP AND ALONG THE BOUNDARY. AS A RESULT...THE BEST RAIN LOOKS TO STAY TO OUR WEST THURSDAY NIGHT...BUT THERE WILL BE AN INCREASING THREAT FOR SHOWERS AND ISOLATED THUNDERSTORMS. THE STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL CONTINUE TO ADVECT PLENTY OF MOIST AIR INTO THE REGION RIGHT OUT OF THE SUBTROPICS...WITH PWATS EXPECTED TO REACH NEAR 1.50 INCHES. IT WILL BE MUGGY AHEAD OF THE BOUNDARY WITH MIN TEMPS IN THE UPPER 50S TO LOW 60S FOR MANY AREAS. THE BEST RAINFALL LOOKS TO FINALLY REACH OUR AREA FOR FRIDAY INTO FRIDAY NIGHT. RAINFALL MAY BRIEFLY FALL HEAVILY AT TIMES...WITH OVER AN INCH POSSIBLE IN A 6 HR PERIOD FOR SOME LOCATIONS. THIS WILL ESPECIALLY BE TRUE WITHIN ANY EMBEDDED CONVECTION THAT MAY OCCUR WITHIN THE SHIELD OF RAIN SHOWERS...AS SOME ELEVATED INSTABILITY WILL BE PRESENT. WITH THE RAIN/CLOUDS EXPECTED...MAX TEMPS WILL BE COOLER THAN RECENT DAYS...WITH ONLY MID 60S TO LOW 70S ACROSS THE REGION. THE HEAVIEST RAIN WILL BE ENDING FROM WEST TO EAST ON FRIDAY NIGHT...BUT IT WILL CERTAINLY BE TAKING ITS TIME AS IT MOVES ACROSS THE AREA. IT MAY TAKE UNTIL SUNRISE SATURDAY FOR MOST OF THE RAIN TO WIND DOWN ACROSS OUR AREA AS THE FRONT CROSSES FROM WEST TO EAST. TOTAL QPF LOOKS TO GENERALLY BE ONE TO TWO INCHES...ALTHOUGH SOME HIGHER AMOUNTS WILL BE POSSIBLE ACROSS THE HIGH TERRAIN...SOUTHERN AREAS...AND ANY PLACE THAT SEES EMBEDDED CONVECTIVE ELEMENTS. OVERNIGHT LOWS WILL STILL BE IN THE 50S...BUT COOLER AND LESS HUMID AIR WILL MAKING ITS WAY ON IN. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AN UPPER LOW OVER THE WESTERN GREAT LAKES WILL BE SLOWLY APPROACHING THE NORTHEASTERN U.S. SATURDAY AND SUNDAY. THE COLD FRONT AND LOW LEVEL FORCING SHOULD BE EXITING EASTERN NY AND WESTERN NEW ENGLAND SATURDAY MORNING...LEAVING LINGERING SCATTERED SHOWERS OVER OUR AREA INTO SATURDAY NIGHT. CLOUDS IN THE MORNING AND SOME BREAKS OF SUN IN THE AFTERNOON SHOULD SUPPORT HIGHS IN THE 60S TO AROUND 70...SOME UPPER 50S IN HIGHER TERRAIN. WEAK FORCING BUT APPROACHING UPPER DYNAMICS ASSOCIATED WITH THE APPROACHING AND DEVELOPING UPPER LOW IS EXPECTED TO SUPPORT PERIODS OF CLOUDS AND SUN AND ISOLATED TO SCATTERED SHOWERS SUNDAY BUT MOST AREAS SHOULD NOT SEE RAIN. BEST COVERAGE OF SHOWERS MAY BE THE SOUTHERN GREEN MOUNTAINS AND THE BERKSHIRES BUT EVEN THERE SHOULD BE WIDELY SCATTERED. HIGHS SUNDAY IN THE 60S TO AROUND 70 WITH UPPER 50S ONCE AGAIN IN HIGHER TERRAIN. THE UPPER LOW AND UPPER COLD POOL ARE OVER OUR REGION MONDAY AND TUESDAY WITH THE CLASSIC DIURNAL INSTABILITY DAYTIME CLOUDS... SHOWERS AND ISOLATED THUNDERSTORMS...AND PARTIAL CLEARING DURING THE NIGHT. HIGHS MONDAY AND TUESDAY IN THE MID TO UPPER 60S...WITH UPPER 50S IN HIGHER TERRAIN. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... FRONTAL BOUNDARY OVER THE REGION PROVIDING SOME FOCUS FOR SHOWERS AND ISOLATED THUNDERSTORMS IN CENTRAL NY THAT ARE TRACKING EAST BUT WEAKENING AT THE SAME TIME. SOME QUESTION AS TO WHETHER THE SCATTERED SHOWERS AND STORMS MAKE IT TO KALB AND KGFL BETWEEN 07Z AND 13Z- 14Z. IF A SHOWER WERE TO AFFECT KALB AND KGFL...IT WOULD BE CLOSER TO 07Z-09Z...BUT THERE ARE SOME LINGERING SHOWERS BEHIND THE LEADING EDGE...SO JUST KEEPING VCSH THROUGH ABOUT 13Z-14Z. IF A SHOWER OR ISOLATED THUNDERSTORM SURVIVES ITS TRACK INTO THE MORE STABLE ENVIRONMENT AROUND KALB AND KGFL...WILL AMEND TO MVFR...AS ANY IFR WOULD BE BRIEF IF AT ALL. RAIN SHOULD NOT MAKE IT TO KPSF OR KPOU. OUTSIDE OF THE SCATTERED ACTIVITY EARLY THIS MORNING...CONDITIONS SHOULD BE VFR...WITH CEILINGS ABOVE 4000 FEET. CONVECTIVE DEBRIS ABOVE 4000 FEET SHOULD PREVENT ANY FOG OR LOW CLOUDS FROM FORMING. VFR CONDITIONS SHOULD CONTINUE THROUGH THE DAY TODAY...BUT SCATTERED SHOWERS COULD DEVELOP LATE INT HE AFTERNOON AND EVENING SO INDICATING VCSH AFTER 0000Z AT KALB AND KGFL. THERE COLD ALSO BE SOME LOWER CLOUDS BELOW 3000 FEET THAT BEGIN TO DEVELOP THIS EVENING AS THE FRONTAL BOUNDARY DRIFTS EAST AND A MORE HUMID AIRMASS SLOWLY BUILDS EAST ACROSS THE REGION. WINDS TONIGHT WILL GENERALLY BE LESS THAN 5 KNOTS BEFORE BECOMING SOUTHERLY WEDNESDAY AROUND 5-10 KNOTS. OUTLOOK... THURSDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA. FRIDAY: HIGH OPERATIONAL IMPACT. DEFINITE SHRA...TSRA. FRIDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE SHRA...TSRA. SATURDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA. SATURDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA. SUNDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA. SUNDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA. MONDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA. && .FIRE WEATHER... RAIN SHOWERS HAVE OCCURRED OVERNIGHT ACROSS MANY AREAS. THERE WILL BE A THREAT FOR RAIN SHOWERS AND THUNDERSTORMS OVER THE NEXT FEW DAYS...ESPECIALLY FOR THURSDAY NIGHT THROUGH FRIDAY NIGHT...WHEN A WIDESPREAD HEAVY RAINFALL IS EXPECTED. RH VALUES WILL FALL TO 40 TO 50 PERCENT THIS AFTERNOON ALONG WITH SOUTH WINDS AROUND 10 MPH. RH VALUES WILL RETURN TO NEAR 90 PERCENT TONIGHT WITH CONTINUED SOUTH WINDS AROUND 10 MPH. RH VALUES WILL FALL BACK TO 45 TO 55 PERCENT ON TOMORROW AFTN WITH STRONGER SOUTHERLY WINDS OF 10 TO 20 MPH. && .HYDROLOGY... RAINFALL OVERNIGHT FROM SHOWERS AND THUNDERSTORMS LEAD TO SOME VERY MINOR RISES /LESS THAN A HALF A FOOT/ ACROSS THE WESTERN MOHAWK VALLEY. DURING THE DAY TODAY...SOME ADDITIONAL SHOWERS OR THUNDERSTORMS WILL BE POSSIBLE OVER FAR WESTERN AREAS...BUT THIS WILL HAVE LIMITED IMPACT ON OUR HSA. ASIDE FROM AN ISOLATED SHOWER...MAINLY DRY CONDITIONS ARE EXPECTED FOR TONIGHT INTO TOMORROW. HOWEVER...AN APPROACHING FRONTAL BOUNDARY WILL RETURN WIDESPREAD RAIN TO THE REGION FOR LATE TOMORROW NIGHT THROUGH FRIDAY AND INTO FRIDAY NIGHT. MODERATE TO HEAVY RAINFALL IS POSSIBLE...WITH MOST AREAS EXPECTED TO RECEIVE ONE TO TWO INCHES OF RAINFALL. SOME SPOTS CAN LOCALLY SEE HIGHER AMOUNTS AS WELL. THIS RAINFALL WILL LEAD TO WITHIN BANK RISES ON RIVERS/STREAMS. AT THIS POINT...NO FLOODING IS EXPECTED...ALTHOUGH IF RAINFALL IS GREATER THAN EXPECTED...THEN MINOR RIVER FLOODING COULD BE POSSIBLE AT A FEW LOCATIONS. ALSO...SINCE THE RAINFALL IS EXPECTED TO FALL HEAVY IN A SHORT PERIOD OF TIME...MINOR NUISANCE FLOODING OF POOR DRAINAGE OR LOW LYING AREAS COULD BE POSSIBLE...SUCH AS IN URBAN AREAS. PONDING OF WATER IS EXPECTED ON ROADWAYS...MAKING FOR SLOWER TRAVEL. BEHIND THIS SYSTEM...SOME ISOLATED TO SCATTERED RAIN SHOWERS ARE POSSIBLE OVER THE WEEKEND...BUT COVERAGE SHOULD BE SMALL ENOUGH TO PREVENT ANY ADDITIONAL HYDROLOGIC CONCERNS. THIS SHOULD ALLOW RIVER AND STREAM LEVELS TO RECEDE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...FRUGIS NEAR TERM...FRUGIS SHORT TERM...FRUGIS LONG TERM...NAS AVIATION...NAS FIRE WEATHER...FRUGIS HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
127 AM EDT WED MAY 14 2014 .SYNOPSIS... A BACKDOOR COLD FRONT IS SITUATED SOUTH AND WEST OF THE REGION. THIS BOUNDARY WILL REMAIN NEARLY STATIONARY THROUGH THE DAY ON WEDNESDAY...BEFORE LIFTING ACROSS THE AREA AS A WARM FRONT ON WEDNESDAY NIGHT. SOME SCATTERED SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THIS BOUNDARY MAY IMPACT MAINLY WESTERN PARTS OF THE REGION. A WARM AND HUMID AIR MASS WILL BE IN PLACE ON THURSDAY...BEFORE A SLOW MOVING COLD FRONT BRINGS A WIDESPREAD SOAKING RAIN TO THE ENTIRE REGION FOR LATE THURSDAY NIGHT THROUGH SATURDAY MORNING. && .NEAR TERM /THROUGH TODAY/... AS OF 127 AM EDT...A BACKDOOR FRONTAL BOUNDARY IS DRAPED FROM CENTRAL NY SOUTHWARD THROUGH CENTRAL PA AND TOWARDS THE MID ATLANTIC STATES. THERE IS A SHARP RISE IN THE DEWPOINTS GOING FROM EAST TO WEST ACROSS OUR AREA...WITH DEWPOINTS ONLY NEAR 40 F OVER THE BERKSHIRES RISING TO NEAR 60 F IN THE WESTERN MOHAWK VALLEY. A CLUSTER OF SHOWERS/THUNDERSTORMS THAT DEVELOPED ALONG THE BOUNDARY HAVE BEEN MOVING NORTHEASTWARD INTO THE MORE STABLE AIR. WHILE THESE SHOWERS/THUNDERSTORMS ARE WEAKENING...RAIN WITH EMBEDDED THUNDER HAS MADE IT INTO THE WESTERN MOHAWK VALLEY AND WESTERN ADIRONDACKS. THERE HAVE BEEN SOME HEAVY DOWNPOURS...WITH RADAR ESTIMATES SHOWING NEARLY ONE INCH OF RAIN HAVING FALLEN ALREADY IN EXTREME SOUTHERN HERKIMER COUNTY. THESE SHOWERS AND THUNDERSTORMS WILL CONTINUE TO WEAKEN...BUT ALSO MOVE NORTHEAST. ALL AREAS WEST AND NORTH OF THE CAPITAL REGION MAY SEE SOME RAIN OVERNIGHT...ALTHOUGH RADAR TRENDS...AS WELL AS SEEN IN THE LATEST 3KM HRRR GUIDANCE...ALL SHOW THIS ACTIVITY WEAKENING AND EVENTUALLY DISSIPATING TOWARDS DAYBREAK...AS THE BEST MOISTURE/FORCING/INSTABILITY ALL REMAIN TO THE WEST OVER CENTRAL NY. AS A RESULT OF WEAKENING TREND...NO FLOODING OR SEVERE WX IS ANTICIPATED...ALTHOUGH SOME PONDING OF WATER AND HIGHER FLOWS ON SMALL CREEKS IS POSSIBLE ACROSS FAR WESTERN PARTS OF OUR AREA. AS A RESULT OF THE SHOWERS/THUNDERSTORMS...MOST AREAS WILL BE MOSTLY CLOUDY OVERNIGHT...WITH THE MOST BREAKS ACROSS FAR SOUTHERN PARTS OF THE AREA. OVERNIGHT LOWS WILL MAINLY IN THE 50S...WITH SOME UPPER 40S IN THE ADIRONDACKS AND WESTERN NEW ENGLAND. WED 500HPA RIDGE AXIS IS THROUGH FCA AND DRIFTS ONLY SLOWLY TO NEW ENG CST. THIS ALLOWS CDFNT IN GRTLKS TO TO BEGIN TO SHIFT E...BUT IT REMAINS PARALLEL TO THE SERIOUSLY MERIDIONAL 500HPA FLOW...AND ITS EASTWARD PROGRESS WILL BE GLACIAL. WITH SOME SUN...CAPE VALUES ALONG W FCA REACH 500-1500 IN VARIOUS MDLS AS SW FLOW ADVECTS INCR TD OVER W AREAS. WITH CDFNT APPROACHING IT WILL BE THE FOCUS FOR CONVECTION IN W AREAS WED AFTN. HWVR FURTHER E AIR MASS WILL REMAIN STABLE. MOST OF FCA IN EVOLVING WM SECTOR WED AS MARINE LAYER DISSIPATES...HWVR THIS WILL BE SLOWEST IN THE EAST WHERE IT IS DEEPER. WITH HIGH MAY SUN...EVEN THOUGH MDL RH 50-70 PCT...THIS WILL GIVE WAY TO SUN AT TIMES IN MANY AREAS. MAX TEMPS WILL REACH THE 70S...WITH SOME NEAR 80 READINGS. THE NORMAL TEMP PATTERN WILL BE REVERSED...WARMEST AREAS WILL BE WEST AND NORTH...COOLEST IN MID HUD VLY AND W CT WHERE MARITIME AIR WILL REMAIN MOST FIRMLY ENTRENCHED...AND SOME ADDITIONAL LLVL MOISTURE MAY BE ADVECTED NWRD...RESULTING IN MORE CLOUDS. && .SHORT TERM /TONIGHT THROUGH 6 PM THURSDAY/... POPS WILL CONTINUE TO BE ON THE LOW SIDE THROUGH EARLY THURSDAY (GENERALLY IN THE 20 TO 30 PERCENT RANGE. AS THE MARITIME INFLUENCE BEGINS TO WANE AND THE FRONTAL BOUNDARY TO THE WEST GETS CLOSER... POPS ARE FORECAST TO SLOWLY INCREASE THURSDAY AFTERNOON AND NIGHT... REACHING LIKELY LEVELS BY AROUND SUNRISE FRIDAY. HOWEVER...THERE ARE SOME MODEL FORECASTS THAT INDICATE THAT THE MORE WIDESPREAD RAINFALL MAY HOLD OFF UNTIL SOMETIME DURING THE DAY ON FRIDAY. NOT MUCH THREAT FOR THUNDERSTORMS UNTIL THURSDAY AFTERNOON WHEN SURFACE WINDS BECOME MORE SOUTHERLY AND THE MARITIME INFLUENCE BECOMES NEGLIGIBLE ACROSS MOST OF THE REGION. HIGHS WEDNESDAY WILL GENERALLY BE IN THE 70S...WITH THE COOLEST TEMPS ACROSS THE MID HUDSON VALLEY AND LITCHFIELD COUNTY. LOWS WEDNESDAY NIGHT WILL BE IN THE MID 50S TO LOWER 60S. HIGHS THURSDAY IN THE MID 70S TO LOWER 80S. LOWS THURSDAY NIGHT IN THE UPPER 50S TO LOWER 60S. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... THE EXTENDED FORECAST BEGINS VERY UNSETTLED WITH A STRONG UPPER LEVEL TROUGH IMPACTING THE FORECAST AREA. A POTENT DISTURBANCE MOVING N/NE ALONG A FRONTAL BOUNDARY WILL BRING PERIODS OF RAINFALL...POTENTIALLY HEAVY...TO ERN NY AND WRN NEW ENGLAND FRIDAY INTO SATURDAY. THE UPPER LEVEL LOW MAY CUT OFF OVER PA AND THE NORTHEAST LATE IN THE WEEKEND...AND KEEP A CHANCE OF SHOWERS IN THE FCST FOR MUCH OF THE REGION INTO EARLY NEXT WEEK. THE LATEST GFS/ECMWF/ENSEMBLES/WPC GUIDANCE ARE ALL IN FAIRLY GOOD AGREEMENT THAT A FRONTAL BOUNDARY WILL SLOWLY APPROACH FROM THE WEST ON FRIDAY. THERE WILL BE A DEEP FETCH OF MOISTURE OUT OF THE GULF OF MEXICO AND WRN ATLANTIC LATE IN THE WEEK. PWAT ANOMALIES WILL GENERALLY BE 1 TO 3 STANDARD DEVIATIONS ABOVE NORMAL ACCORDING TO THE LATEST GEFS. AN ANOMALOUSLY STRONG 850 HPA LOW LEVEL JET WITH STRONG SOUTHERLIES /+V ANOMALIES/ OF 3 TO 4 STANDARD DEVIATIONS ABOVE NORMAL WILL IMPACT ERN NY AND WRN NEW ENGLAND LATE FRI AFTERNOON INTO SATURDAY MORNING. STRONG UPWARD VERTICAL MOTION WILL BE GENERATED WITH A WAVE MOVING ALONG THE BOUNDARY...AND THE UPPER LEVEL TROUGH TURNING NEGATIVELY TILTED...WHICH WILL FOCUS THE MODERATE TO HEAVY RAINFALL. INITIALLY...THE RAINFALL WILL BE WEST OF THE HUDSON RIVER VALLEY ON FRI...THEN GRADUALLY MOVE EASTWARD ACROSS THE REST OF THE FCST AREA. LIKELY AND CATEGORICAL POPS WERE KEPT IN THE FCST FRI INTO SATURDAY. THERE IS ALSO A CHANCE OF THUNDERSTORMS OR EMBEDDED CONVECTION IN THE RAIN BANDS...AS THE GFS CONTINUES TO SHOW SHOWALTER INDICES SLIGHTLY BELOW ZERO. TOTAL QPF RIGHT NOW /WPC...GFS...AND ECMWF/ RANGES FROM ONE TO TWO AND A HALF INCHES WITH PERHAPS SOME LOCALLY HIGHER AMOUNTS IN A 24-36 HR TIME FRAME. A MENTION IN THE HWO WILL CONTINUE FOR HVY RAINFALL FRI INTO SAT. PONDING OF WATER ON ROADWAYS...AND POOR DRAINAGE FLOODING COULD OCCUR IN LOW LYING AREAS...BUT IT IS STILL UNCERTAIN ANY POTENTIAL FLOODING WILL OCCUR ON THE MAIN STEM RIVERS. SOME WITHIN BANK RISES WILL BE POSSIBLE...AND THIS SITUATION WILL CONTINUE TO BE MONITORED. TEMPS WILL GENERALLY BE A LITTLE BELOW NORMAL IN THE DAMP AIR MASS WITH HIGHS IN THE 60S TO L70S ON FRI...LOWS IN THE M40S TO U50S FRI NIGHT. HIGHS WILL BE IN THE M60S TO L70S ON SATURDAY WITH U50S TO M60S OVER THE HILLS/MTNS. THE RAIN WILL TEND TO TAPER TO SHOWERS ON SATURDAY...ESPECIALLY EAST OF THE HUDSON RIVER VALLEY...AS THE COLD FRONT...AND SFC WAVE MOVE EASTWARD. SAT NIGHT INTO SUNDAY... THE UPPER LEVEL LOW REMAINS UPSTREAM OVER THE NRN GREAT LAKES REGION...AS SFC HIGH PRESSURE ATTEMPTS TO RIDGE IN FROM THE SOUTH AND WEST. A SERIES OF SHORT-WAVES WILL ROTATE AROUND THE UPPER LEVEL LOW THAT WILL BE CLOSING OFF NEAR THE REGION. A SLIGHT TO LOW CHC OF SHOWERS WAS KEPT IN THE FCST WITH THE HIGHER CHANCES NORTH AND EAST OF THE CAPITAL REGION. LOWS WILL GENERALLY BE IN THE 40S TO L50S...AND HIGHS WILL REMAIN A SHADE BELOW NORMAL IN THE 60S TO L70S WITH SOME U50S OVER THE SRN DACKS...AND SRN GREENS. SUNDAY NIGHT INTO TUESDAY...THE UPPER LEVEL LOW CUTS OFF AND BECOMES VERTICALLY STACKED OVER NY AND NEW ENGLAND BY MONDAY AFTERNOON. THE CYCLONIC VORTICITY ADVECTION COUPLED WITH THE MID AND UPPER LEVEL COLD POOL WILL KEEP A SLIGHT TO LOW CHC OF SHOWERS IN THE FCST INTO TUESDAY. THE SHOWERS WILL BE TIED TO THE DIURNAL HEATING MONDAY AND TUESDAY AFTERNOONS. THE GFS TENDS TO MOVE THE CUT-OFF EAST OF THE REGION BY TUESDAY...WITH THE ECMWF MOVING IT MORE TO THE SOUTH TOWARDS THE DELMARVA REGION. TEMPS WILL BE RUNNING A BIT COOLER THAN NORMAL INTO EARLY NEXT WEEK. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... FRONTAL BOUNDARY OVER THE REGION PROVIDING SOME FOCUS FOR SHOWERS AND ISOLATED THUNDERSTORMS IN CENTRAL NY THAT ARE TRACKING EAST BUT WEAKENING AT THE SAME TIME. SOME QUESTION AS TO WHETHER THE SCATTERED SHOWERS AND STORMS MAKE IT TO KALB AND KGFL BETWEEN 07Z AND 13Z- 14Z. IF A SHOWER WERE TO AFFECT KALB AND KGFL...IT WOULD BE CLOSER TO 07Z-09Z...BUT THERE ARE SOME LINGERING SHOWERS BEHIND THE LEADING EDGE...SO JUST KEEPING VCSH THROUGH ABOUT 13Z-14Z. IF A SHOWER OR ISOLATED THUNDERSTORM SURVIVES ITS TRACK INTO THE MORE STABLE ENVIRONMENT AROUND KALB AND KGFL...WILL AMEND TO MVFR...AS ANY IFR WOULD BE BRIEF IF AT ALL. RAIN SHOULD NOT MAKE IT TO KPSF OR KPOU. OUTSIDE OF THE SCATTERED ACTIVITY EARLY THIS MORNING...CONDITIONS SHOULD BE VFR...WITH CEILINGS ABOVE 4000 FEET. CONVECTIVE DEBRIS ABOVE 4000 FEET SHOULD PREVENT ANY FOG OR LOW CLOUDS FROM FORMING. VFR CONDITIONS SHOULD CONTINUE THROUGH THE DAY TODAY...BUT SCATTERED SHOWERS COULD DEVELOP LATE INT HE AFTERNOON AND EVENING SO INDICATING VCSH AFTER 0000Z AT KALB AND KGFL. THERE COLD ALSO BE SOME LOWER CLOUDS BELOW 3000 FEET THAT BEGIN TO DEVELOP THIS EVENING AS THE FRONTAL BOUNDARY DRIFTS EAST AND A MORE HUMID AIRMASS SLOWLY BUILDS EAST ACROSS THE REGION. WINDS TONIGHT WILL GENERALLY BE LESS THAN 5 KNOTS BEFORE BECOMING SOUTHERLY WEDNESDAY AROUND 5-10 KNOTS. OUTLOOK... THURSDAY THROUGH THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. FRIDAY THROUGH FRIDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY RA...TSRA. SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. && .FIRE WEATHER... A FRONTAL BOUNDARY WAS NEARLY STATIONARY JUST TO THE SOUTH OF THE REGION. AT THE SAME TIME...HIGH PRESSURE WAS BUILDING IN OVER NORTHERN NEW ENGLAND INTO THE CANADIAN MARITIMES. THIS WILL KEEP PARTLY TO MOSTLY CLOUDY CONDITIONS ACROSS THE REGION...ALONG WITH THE THREAT FOR ISOLATED TO SCATTERED SHOWERS THROUGH TONIGHT. THE FRONTAL BOUNDARY WILL LIFT NORTHWARD AS A WARM FRONT DURING THE MID WEEK PERIOD. A MORE WIDESPREAD RAINFALL IS EXPECTED LATE IN THE WEEK AS A STRONGER FRONT OVER THE GREAT LAKES PUSHES TOWARD THE EASTERN SEABOARD. RH VALUES WILL RECOVER TO BETWEEN 80 AND 100 PERCENT TONIGHT...THEN LOWER TO BETWEEN 35 AND 50 PERCENT WEDNESDAY AFTERNOON. SURFACE WINDS WILL BE SOUTHEAST AT 5 TO 15 MPH TONIGHT AND WEDNESDAY...WITH GUSTS OF 20 TO 25 MPH ON WEDNESDAY. && .HYDROLOGY... NO WIDESPREAD HYDROLOGIC ISSUES ARE EXPECTED OVER THE NEXT FEW DAYS. A FRONTAL BOUNDARY WAS NEARLY STATIONARY JUST TO THE SOUTH OF THE REGION. AT THE SAME TIME...HIGH PRESSURE WAS BUILDING IN OVER NORTHERN NEW ENGLAND INTO THE CANADIAN MARITIMES. THIS WILL KEEP PARTLY TO MOSTLY CLOUDY CONDITIONS ACROSS THE REGION...ALONG WITH THE THREAT FOR ISOLATED TO SCATTERED SHOWERS THROUGH TONIGHT. THE FRONTAL BOUNDARY WILL LIFT NORTHWARD AS A WARM FRONT DURING THE MID WEEK PERIOD. A MORE WIDESPREAD RAINFALL IS EXPECTED LATE IN THE WEEK AS A STRONGER FRONT OVER THE GREAT LAKES PUSHES TOWARD THE EASTERN SEABOARD. ANY RAINFALL THROUGH THURSDAY NIGHT WILL BE LIGHT AND HAVE LITTLE IMPACT ON AREA STREAMS AND RIVERS. THE RAINFALL FRIDAY AND FRIDAY NIGHT COULD BE HEAVY AND WE WILL CONTINUE TO WATCH NUMERICAL MODEL TRENDS CLOSELY. 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...FRUGIS NEAR TERM...FRUGIS/SNYDER SHORT TERM...GJM LONG TERM...GJM AVIATION...NAS FIRE WEATHER...GJM HYDROLOGY...GJM
AREA FORECAST DISCUSSION...CORRECTED
NWS MIAMI FL
306 AM EDT WED MAY 14 2014 ...CORRECTED MISSPELLING IN SEVENTH LINE... .SHORT TERM (TODAY-FRIDAY)... MOISTURE WILL BE ON THE INCREASE ACROSS SOUTH FLORIDA THROUGH THURSDAY AS A WEAK MID/UPPER LEVEL TROUGH APPROACHES FROM THE BAHAMAS. THIS TROUGH IS ROTATING AROUND THE BASE OF A LARGE RIDGE OVER THE ATLANTIC. AS THE LOW TRACKS ACROSS SOUTH FLORIDA LATE TODAY AND THURSDAY, LAPSE RATES WILL BECOME MORE CONDUCIVE FOR THUNDERSTORM DEVELOPMENT MAINLY DURING THE AFTERNOON AND EVENING HOURS, ALTHOUGH FORECAST SOUNDINGS ONLY SHOW MODEST INSTABILITY. ADJUSTED THE POPS FOR THIS MORNING BASED ON THIS AND THE FACT THE HRRR DOES NOT SHOW MUCH OUT THROUGH 18Z THIS AFTERNOON. FORECAST SOUNDINGS ALSO INDICATE THE PWAT INCREASING TO AROUND 1.8 INCHES TODAY AND CLOSE TO TWO INCHES ON THURSDAY WHICH IS SLIGHTLY ABOVE THE AVERAGE FOR MID MAY. THAT BEING SAID, THERE WILL BE AN INCREASING THREAT FOR THUNDER BUT THE STORMS ARE NOT EXPECTED TO BE SEVERE WITH GUSTY WINDS AND FREQUENT LIGHTNING STRIKES THE PRIMARY CONCERNS ALONG WITH THE BRIEF HEAVY RAIN. OVERALL RAINFALL AMOUNTS WILL NOT BE EXCESSIVE WITH WPC QPF ONLY DEPICTING ONE-HALF TO ONE INCH TOTALS THROUGH FRIDAY MORNING. THERE HOWEVER COULD BE LOCALLY HEAVIER AMOUNTS IN ISOLATED LOCATIONS WHEREVER ECHOES MOVE OVER THE SAME AREA. THE MORE IMPRESSIVE ASPECT OF THE UPCOMING WEATHER CONDITIONS IS A LARGE SCALE MID/UPPER TROUGH THAT HAS BEEN EVOLVING ACROSS THE CENTRAL/SOUTHERN PLAINS STATES THE PAST FEW DAYS. THIS TROUGH WILL BEGIN TO SHIFT EASTWARD ON FRIDAY IN RESPONSE TO A LARGE AMPLIFYING RIDGE ALONG THE COAST OF CALIFORNIA. THE WEAK TROUGH OVER SOUTH FLORIDA WILL BEGIN TO BECOME ABSORBED BY THE UPSTREAM TROUGH AND LIFT TO THE NORTHEAST ON FRIDAY ALLOWING FOR A LITTLE BIT OF DRYING TO THE AREA AS A LATE SEASON COLD FRONT MOVES ACROSS SOUTH FLORIDA DURING THE DAY WITH PWAT FALLING TO AROUND 1.5 INCHES. THIS WILL ALSO LEAD TO A DECREASING TREND IN SHOWER AND THUNDERSTORM COVERAGE. .LONG TERM (SATURDAY-TUESDAY)... THE EXTENDED PERIOD LOOKS TO BE QUITE DRY WITH FORECAST SOUNDINGS SHOWING PWAT FALLING TO AROUND ONE-HALF INCH OVER THE WEEKEND AND INTO EARLY NEXT WEEK. THESE ARE QUITE IMPRESSIVE AND IF THIS MATERIALIZES, IT WILL BE LOWEST PWAT VALUES FOR MAY ACROSS SOUTH FLORIDA SINCE 1948. AS THE TROUGH EXITS TO THE EAST, A LARGE RIDGE WILL BUILD OVER THE GULF OF MEXICO WHICH WILL KEEP SOUTH FLORIDA IN A DRY, NORTHWESTERLY UPPER AIR FLOW THROUGH TUESDAY. && .MARINE... AN EAST SOUTHEAST WIND WILL CONTINUE THROUGH TODAY AT 15-20 KNOTS AND THEN SLOWLY DIMINISH TONIGHT AND THURSDAY INTO THE END OF THE WEEK WHILE VEERING TO THE SOUTHEAST TONIGHT THEN TO THE SOUTH ON THURSDAY AND SOUTHWEST ON THURSDAY NIGHT. THE WIND WILL THEN SHIFT TO THE NORTH AND INCREASE AGAIN TO THE 15-20 KNOT RANGE ON FRIDAY AS A COLD FRONT MOVES ACROSS THE LOCAL WATERS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 85 75 86 72 / 60 50 70 50 FORT LAUDERDALE 85 76 86 74 / 60 50 70 50 MIAMI 84 76 86 74 / 60 50 70 50 NAPLES 88 73 85 72 / 40 40 50 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR FLZ168-172-173. AM...NONE. GM...NONE. && $$ SHORT TERM...13/SI LONG TERM....30/KOB
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
210 AM EDT WED MAY 14 2014 .SYNOPSIS... ISSUED AT 202 AM EDT WED MAY 14 2014 A FRONTAL BOUNDARY HAS STALLED ACROSS OHIO TO EASTERN TENNESSEE THIS MORNING. SEVERAL FRONTAL WAVES WILL MOVE NORTHEAST ALONG THIS BOUNDARY TODAY INTO TONIGHT. SCATTERED SHOWERS WILL BECOME MORE NUMEROUS THIS AFTERNOON...AND PERHAPS A FEW THUNDERSTORMS EAST OF INTERSTATE 69 WILL OCCUR. && .UPDATE... ISSUED AT 916 PM EDT TUE MAY 13 2014 GRIDS/ZONES PATCHED UP TO KEEP HIGHER POPS SE THROUGH AROUND 6Z AND THEN TRANSITION HIGHER (YET ONLY CHC) POPS TO NW OVERNIGHT. STRONGEST CONVECTION ACROSS CENTRAL INDIANA WILL MAINLY BYPASS THE SE AREAS OF THE CWA. HOWEVER...EXPANDING AREA OF RAIN/EMBEDDED THUNDER MAY STILL CLIP SE SECTIONS...WARRANTING CONTINUED LIKELY POPS WITH MENTION OF THUNDER. AS THIS DEPARTS...A WEAK DISTURBANCE WILL MOVE OUT OF NE MISSOURI/SW ILLINOIS AND TRACK TOWARDS CENTRAL/WEST SECTIONS OF THE AREA BRINGING A DECENT SHOT AT SOME LIGHT RAIN/SHOWERS INTO THE OVERNIGHT HOURS. HRRR HAS BEEN GENERALLY SPOT ON FOR MOST OF THE ACTIVITY THUS FAR SO WILL LEAN TOWARDS IT FOR THE GRIDS. REST OF THE FORECAST GENERALLY ON TRACK. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 432 PM EDT TUE MAY 13 2014 THUNDERSTORMS WERE SPREADING ACROSS THE AREA THIS AFTERNOON ALONG A PRE/FRONTAL TROF...BUT FARTHER AHEAD OF THE COLD FRONT. THE AIRMASS HAD DESTABILIZED THIS AFTERNOON WITH DAYTIME HEATING...WITH SFC BASED CAPE VALUES RISING WELL ABOVE 2000 J/KG IN FRONT OF THE STORMS PER SPC MESO ANALYSIS. MARGINAL SEVERE THREAT WILL END LATE THIS AFTERNOON AS THE FRONT MOVES EAST...AND AS COOLER AND DRIER AIR TEMPORARILY SPREADS BACK INTO THE AREA. PRECIPITABLE WATER VALUES AS HIGH AS 1.75...BUT STORMS WERE MOVING FAST ENOUGH TO KEEP NEARLY ALL RAINFALL AMOUNTS UNDER AN INCH. A SHORT WAVE TROF WILL LIFT NORTHEAST WEDNESDAY...WITH RAIN SPREADING ACROSS THE AREA AS THIS SYSTEM WILL BE ABLE TO TAP CONSIDERABLE MOISTURE. FAVORED THE 12KM NAM WHICH HAS BEEN REASONABLY CONSISTENT FROM RUN TO RUN AND APPEARS TO BE HANDLING THE EJECTING UPPER TROF WELL. RAISED RAIN CHANCES WEDNESDAY TO COME MORE IN LINE WITH THESE EXPECTATIONS. && .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 432 PM EDT TUE MAY 13 2014 POTENT SW DISTURBANCE EDGING OUT OF NM THIS AFTN AND THROUGH THE SRN PLAINS TONIGHT WILL INDUCE A DEEPENING FNTL WAVE ALG TRAILING CDFNT WED AS THE ENTIRE SYS TURNS NE AND PHASES W/NRN STREAM SW AMPLIFYING RAPIDLY SEWD. NET RESULT LOOKS TO BE A SIG CYCLONE WRAPPING UP ACRS THE WRN OH VALLEY. TRACK OF SFC LOW FM SW-NE INDIANA POINTS TO HEAVIEST RAINFALL RIGHT THROUGH CNTRL/WRN CWA W/LOW TOPPED CONVN LIKELY ERN HALF. WILL EXPAND THUNDER WWD WED NIGHT. SYS LIFTS OUT RAPIDLY NEWD THU-FRI W/SOME DIURNALLY FVRD SHRA PSBL N/NE THU AFTN AND S/SE FRI AFTN AS COLD POOL ALOFT SETTLES IN OVERHEAD. OTRWS UNSEASONABLY COLD THROUGH SUN W/PEAK DEPARTURES NR -20 DEGREES THU-FRI. MOIST CYCLONIC FLW AND LIKELY EXTENSIVE LOW CLD CVR SHLD STAVE OFF POTENTIAL FROST THU/FRI NIGHT BUT W/MORE SIG DRYING INDICATED SAT AFTN AND POSITION OF SFC RIDGE AXIS WORRIED SOMEWHAT THAT NRN AREAS COULD FROST SUN AM HWVR WILL AWAIT SPECIFICS OFFERED VIA SHORTER TERM MOS GUIDANCE WINDOW BY THU. OTRWS PATTN PROGRESSION ALOFT WILL YIELD SIG WARMING TREND TO AOA NORMAL BY WED AS NEW TROUGH DIGS IN OUT WEST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 208 AM EDT WED MAY 14 2014 CONTINUED POOR FLIGHT CONDITIONS IFR TO FUELING/ALT REQUIREMENTS THROUGH MUCH OF FORECAST PERIOD. STALLED/SHALLOW FRONTAL BOUNDARY EXTENDS FROM LOWER GREAT LAKES THROUGH OHIO TO EAST CENTRAL TN. NUMEROUS FRONTAL WAVES TO EMANATE FROM SOUTHERN MISSISSIPPI VALLEY NEXT 24 HOURS WITH KFWA WITHIN RICHEST MOISTURE PLUME/DEEP SATURATION THROUGHOUT. INITIAL VFR CONDITIONS FARTHER NW AT KSBN...THOUGH WITH TIME AND APPROACH OF MORE SIGNIFICANT WAVE LATE TONIGHT...ALSO ANTICIPATE CEILINGS PROGRESSIVELY LOWERING INTO IFR DOMINANT. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ UPDATE...FISHER SYNOPSIS...FISHER SHORT TERM...SKIPPER LONG TERM...T AVIATION...MURPHY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1141 PM CDT TUE MAY 13 2014 .SYNOPSIS... ISSUED AT 309 PM CDT TUE MAY 13 2014 TEMPERATURES WERE RUNNING 25 TO 30 DEGREES COLDER THAN 24 HOURS AGO ACROSS THE FORECAST AREA THIS AFTERNOON IN THE WAKE OF THE STRONG FRONT THAT PUSHED THROUGH OVERNIGHT. AT 19Z...THE SHARP COLD FRONT WAS WELL TO THE EAST FROM LOWER MI SOUTH TO LA. AN EXPANSIVE POST FRONTAL STRATUS DECK EXTENDED WEST INTO CENTRAL IA. THE CLOUDS... COMBINED WITH LOW LEVEL COLD ADVECTION ON NW WINDS...WAS LIMITING TEMPERATURES TO THE LOWER TO MID 50S. RADAR MOSAIC INDICATED A FEW DEVELOPING LIGHT SHOWERS LIKELY ALONG THE LAGGING 850 MB FRONT OVER W CENTRAL IL NEAR MACOMB. 12Z UPPER AIR ANALYSIS SHOWED AN UPPER TROUGH REACHING FROM A LOW OVER SOUTHERN CANADA TO A SEPARATE SOUTHERN STREAM VORTEX EMBEDDED IN THE LARGER TROUGH AXIS NEAR THE OK PANHANDLE. UNSEASONABLY COLD TEMPERATURES AROUND ZERO TO SEVERAL DEGREES BELOW AT 850 MB WERE FOUND BEHIND THE FRONT IN THE NW FLOW ACROSS THE DAKOTAS INTO MN AND NW IA. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 309 PM CDT TUE MAY 13 2014 MAIN FOCUS IS ON COOL TEMPERATURES AND POTENTIAL FOR LIGHT PRECIPITATION. TONIGHT...A DEVELOPING MORE ANTICYCLONIC LOW LEVEL FLOW...BACKED BY RAP LOW LEVEL RH FIELDS INDICATES THE STRATUS DECK GRADUALLY CLEARING FROM WEST TO EAST FROM LATE AFTERNOON THROUGH MID EVENING. AT THE SAME TIME...MID AND HIGH LEVEL MOISTURE IN THE SW WITH SUPPORT FROM EMBEDDED VORT MAXIMA WILL KEEP HIGH LEVEL CLOUD COVER IN PLACE. THIS CLOUD COVER SHOULD ELIMINATE THE THREAT OF FREEZING TEMPERATURE OR FROST TONIGHT...BUT STILL LEAD TO WELL BELOW NORMAL TEMPERATURES AS THE 850 MB THERMAL TROUGH PASSING OVERHEAD TOWARD MORNING SENDS TEMPERATURES AT THAT LEVEL CLOSE TO ZERO C. HAVE KEPT MINS NEAR TO BELOW THE LOW END OF GUIDANCE FROM THE UPPER 30S NW TO MID 40S SE. DIURNALLY ENHANCE SHOWERS OVER THE FAR EAST AND SOUTHEAST SHOULD DISSIPATE BY THIS EVENING. WEDNESDAY...THE UPPER LOW OVER THE SOUTHERN PLAINS GETS PULLED NORTHEAST...SENDING LIFT INTO NORTHERN IL BY AFTERNOON. THIS...ALONG WITH A FAVORABLE RIGHT ENTRANCE REGION OF THE UPPER JET LIFTING N-NE INTO EASTERN CANADA WILL SUPPORT SHOWERS MAINLY EAST OF THE MS RIVER IN THE AFTERNOON. WILL KEEP HIGH CHANCE POPS GOING FOR WHAT SHOULD BE A VERY LOW QPF EVENT BASED ON LIMITED MOISTURE AND A DRY LAYER IN THE LOW LEVELS IN FORECAST SOUNDINGS. IN THE SAME AIRMASS AS TODAY...TEMPERATURES SHOULD BE LIMITED TO THE 50S IN THE THICKEST CLOUD COVER AND DEVELOPING SHOWERS ACROSS THE EAST...WHILE HIGHER CLOUD COVER AND DRY AIR MAY ALLOW AREAS WEST OF THE MS RIVER TO REACH THE UPPER 50S TO PERHAPS LOWER 60S. OVERALL...MODEL GUIDANCE MUCH LIKE TODAY LOOKED A BIT TOO OPTIMISTIC IN THE AMOUNT OF WARMING IN THIS AIRMASS AND HAVE TRENDED NEAR TO BELOW THE COOLEST NUMBERS. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 309 PM CDT TUE MAY 13 2014 FORECAST FOCUS ON BELOW NORMAL TEMPERATURES THROUGH THE EXTENDED. WEDNESDAY NIGHT THROUGH FRIDAY...STRONG ENERGY IN THE SOUTHERN STREAM PHASES WITH THE NORTHERN STREAM TO CARVE OUT A MAJOR TROUGH IN THE MIDDLE OF THE COUNTRY. CYCLOGENESIS DEVELOPS IN THE LOWER MS VALLEY ON WEDNESDAY AND RIDES UP A STALLED FRONT INTO THE OHIO VALLEY AND EASTERN GREAT LAKES BY THURSDAY. THIS WILL DUMP CHILLY AIR INTO MUCH OF THE MIDWEST WITH BELOW TO WELL BELOW NORMAL TEMPERATURES THE REMAINDER OF THIS WEEK INTO THE WEEKEND. 850 MB TEMPERATURES ARE PROGGED TO ABOUT -2C OVER THE CWA. MODELS SIMILAR IN KEEPING THE BULK OF THE RAIN...TIED TO THE SURFACE LOW MOVING INTO THE OHIO VALLEY...TO THE EAST OF THE DVN CWA. I WILL CONTINUE WITH CHANCE POPS IN THE FORM OF SCATTERED SHOWERS ESPECIALLY THURSDAY AND FRIDAY DURING THE AFTERNOON AND EARLY EVENING. THIS WILL BE INSTABILITY SHOWERS DUE TO THE COLD AIR ALOFT ASSOCIATED WITH THE VERY IMPRESSIVE (FOR MAY) DEEP TROUGH. EXTENSIVE CLOUD COVER THE REMAINDER OF THIS WEEK WILL KEEP AFTERNOON MAXIMUM TEMPERATURES MAINLY IN THE 50S...WITH LOWS IN THE UPPER 30S TO MID 40S. THE CLOUD COVER WILL PREVENT ANY FROST FORMATION THIS WORK WEEK. FRIDAY NIGHT THROUGH THE WEEKEND...AT THIS POINT IN THE GAME THE FAVORED TIME FOR AT LEAST SCATTERED FROST AND POSSIBLE HEADLINES APPEAR TO BE FRIDAY NIGHT/EARLY SATURDAY MORNING. MODELS SUGGEST A HIGH PRESSURE RIDGE SETTLING INTO THE REGION WITH CLEAR SKIES AND LIGHT WINDS ALLOWING FOR GOOD RADIATIONAL COOLING. LOW TEMPERATURES SHOULD DIP INTO THE 30S BUT EXACT NUMBERS REMAIN TO BE SEEN. DEEP TROUGH BEGINS TO SHIFT TO THE EAST OVER THE WEEKEND ALLOWING FOR A MODERATION IN TEMPERATURES AND RATHER PLEASANT WEATHER. MAXIMUM TEMPERATURES SHOULD PUSH INTO THE 60S WITH LOWS IN THE 40S. EARLY NEXT WEEK...THE 12Z ECMWF HAS BACKED OFF ON SURGING WARMER AIR INTO THE CWA...AND A MORE ACTIVE PATTERN...PUSHING IT OFF UNTIL THE MIDDLE AND END OF NEXT WEEK. ECMWF/GFS WANT TO HANG ON TO THE TROUGH IN THE EAST A BIT LONGER KEEPING TEMPERATURES A BIT BELOW NORMAL AND HOLDING OFF THE RAIN. WE WILL SEE. 21 && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1134 PM CDT TUE MAY 13 2014 VFR CONDITIONS TO CONTINUE FOR THE NEXT 24 HOURS WITH PERIODS OF BKN- OVC MID/HIGH CLOUDS. TOWARD LATE WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT...BKN-OVC CLOUDS WITH BASES AOA 6K AGL TO BECOME COMMON AS UPPER LOW APPROACHES WITH ISOLATED TO WIDELY SCATTERED SHOWERS DEVELOPING. COVERAGE MINIMAL ENOUGH TO KEEP AS VCSH AT BRL/MLI/CID AND LEAVE OUT AT DBQ TERMINAL. NORTHWEST WINDS AROUND 5 KTS OVERNIGHT TO SHIFT GRADUALLY TO THE NORTH AT 5 TO 10 KTS WEDNESDAY AFTERNOON AND EVENING. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...11 SHORT TERM...11 LONG TERM...21 AVIATION...NICHOLS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1217 AM CDT Wed May 14 2014 ...Updated synopsis and aviation discussion... .SYNOPSIS... ISSUED AT 1212 AM CDT WED MAY 14 2014 At 00z Wednesday a 500mb trough extended from the Panhandle of Texas northward to an upper low located into western Manitoba. A -31c upper level trough was located on the west side of the Manitoba upper low over central Saskatchewan. A +90 knot upper level jet streak was located near the base of this 500mb trough over New Mexico. A surface to 850mb ridge axis was located over the Central High Plains. 850mb temperatures at 00z Wednesday ranging from +8 at Amarillo to +6c at Dodge City and +3c at Omaha. && .UPDATE... ISSUED AT 224 PM CDT TUE MAY 13 2014 In areas of forecast lows from 33 to 36F, went with an NPW Frost Advisory tonight, same time as the Freeze Warning, 09Z-13Z. && .SHORT TERM...(This evening through Wednesday) ISSUED AT 106 PM CDT TUE MAY 13 2014 A large scale high pressure system over Utah and Wyoming will move just slightly southeast tonight, bringing decreasing winds and clear skies. There is a swath of mid-level clouds in the 080 range across Western Kansas this afternoon. With the suppression from the southeastward progressing surface high pressure, skies will become clear by midnight. Winds will decrease from the current breezy conditions to around 10 MPH by 00z, and then even lower to 06-07 MPH after midnight. For this reason, I lowered temperatures in the west to just below freezing, and posted another NPW Freeze Warning for the 09Z to 13Z time range, basically west of a Scott City to Hugoton line. The NAM and RUC models both support these sub-freezing temperatures out west. As for Wednesday, I made a few slight changes. There is an upper level trough dragging through, with better dynamics to our north. But, we could see a few sprinkles/virga Tuesday afternoon into Tuesday evening. Chose to go with scattered sprinkles since the only support for any precipitation will be from the upper trough crossing, with no significant lower level moisture, and only in our northern 1/3rd of the CWA. Wednesday should be slightly warmer than today, mainly based on the surface high pressure segmenting into two high pressure centers, one in the Wyoming and the other over Oklahoma. Surface winds Wednesday will start out light, then be from the northwest at 10 to 20 mph. This will not be a strong down slope affect, but enough to push maximum temperatures upward a couple to few degrees warmer than today. .LONG TERM...(Wednesday night through Tuesday) ISSUED AT 346 PM CDT TUE MAY 13 2014 A large upper level trough will develop over the upper midwest by Thursday night as northern and southern stream troughs progress eastward and merge together. Surface high pressure will generally be situated across the central plains on the back side of the trough. This will lead to fairly cool weather with highs in the 60s to near 70 Thursday. A few sprinkles are possible Thursday afternoon given the cold upper level temperatures, but low level moisture will be a limiting factor. A few showers are possible by Friday, particularly in far western Kansas given the lack of capping and where temperatures may reach the upper 70s. Saturday night still looks cool as surface high pressure builds into western Kansas. Lows could be cooler than currently forecasted, with some upper 30s possible along interstate 70. By Saturday and Sunday, the flow will become more westerly at mid and high levels, which will allow for lee troughing and some moisture return into western Kansas. There is a slight chance of showers and thunderstorms through this period, but no severe weather or heavy rainfall is expected. High temperatures should remain mainly in the 70s. An upper level trough will develop near the West Coast by Monday and then progress into the Rockies by Tuesday and Wednesday. Low level moisture will continue to increase so that surface based CAPE will be higher each day. Low level moisture return from the Gulf of Mexico is progged to be rather limited even early next week since the prior cold front late this week will have shunted the low level moisture into the tropics. So instead of high CAPE ahead of a dryline and along a weak frontal boundary, instability will be rather marginal. However, given the presence of boundaries and at least marginal to moderate CAPE values, thunderstorms cannot be ruled out through Wednesday. Temperatures will be warming early next week as well, with the warmest readings in far southwest Kansas in the 90s, and cooler 80s along interstate 70. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) ISSUED AT 1212 AM CDT WED MAY 14 2014 Northwest winds will be at 10 knots or less overnight and early Wednesday as a surface to 850mb ridge axis builds across the Central High Plains. VFR conditions will continue overnight and Wednesday based on BUFR soundings indicating only mid level moisture will be present under the 500mb trough as it crosses western Kansas over the next 12 to 18 hours. && .PRELIMINARY POINT TEMPS/POPS... DDC 39 69 41 72 / 10 20 10 10 GCK 37 69 41 73 / 10 20 10 10 EHA 39 72 42 78 / 0 10 10 10 LBL 38 71 42 77 / 0 10 10 10 HYS 40 65 41 66 / 20 20 10 20 P28 42 69 44 71 / 10 20 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING from 4 AM CDT /3 AM MDT/ to 8 AM CDT /7 AM MDT/ this morning FOR KSZ043-044-061>063-074-075-084. FROST ADVISORY from 4 AM to 8 AM CDT this morning FOR KSZ030-031- 045-046-064-076-077-085-086. && $$ UPDATE...Burke SYNOPSIS...Burgert SHORT TERM...Burke LONG TERM...Finch AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS JACKSON KY
129 AM EDT WED MAY 14 2014 .UPDATE... ISSUED AT 129 AM EDT WED MAY 14 2014 ONLY A FEW WIDELY ISOLATED SHOWERS AND THUNDERSTORMS LEFT OUT THERE PRESENTLY. HOWEVER...GIVEN THE PRESENCE OF BOUNDARIES CONTINUING TO LINGER OVER THE AREA FROM EARLIER DAY CONVECTION...CANNOT RULE OUT ISOLATED SHOWERS AND STORMS CONTINUING TO DEVELOP THROUGH THE OVERNIGHT HOURS...ESPECIALLY FOR THE WESTERN HALF OF THE FORECAST AREA. SOME SHOWERS/THUNDERSTORMS ARE BEGINNING TO MOVE INTO THE LAKE CUMBERLAND REGION AND HAS SHOWN SIGNS OF EXPANDING AS THEY MOVE NORTH. THUS...IT LOOKS LIKE UNSETTLED WEATHER WILL CONTINUE IN SOME FASHION THROUGH THE REST OF THE NIGHT. OTHERWISE...FORECAST LOOKS ON TRACK AND WILL UPDATE TEMPERATURES/DEWPOINTS. UPDATE ISSUED AT 1053 PM EDT TUE MAY 13 2014 THERE ARE STILL A FEW ECHOES SHOWING UP ON RADAR ACROSS EASTERN KENTUCKY...MAINLY WEST OF I-75. ANOTHER CLUSTER OF STORMS HAS FIRED UP ACROSS NORTH CENTRAL KENTUCKY...AS AN OUTFLOW BOUNDARY ALIGNED FROM FRANKFORT DOWN TO BOWLING GREEN GRADUALLY MOVES EAST. GIVEN THE PROXIMITY OF THE BOUNDARY AND THE LATEST HRRR SHOWING A FEW MORE POP UPS FROM TIME TO TIME OVERNIGHT...WILL LEAVE AN ISOLATED POP IN THE FORECAST THROUGH THE REST OF THE NIGHT. LOW TEMPERATURES STILL LOOK TO BOTTOM OUT IN THE LOW TO MID 60S ACROSS THE AREA...WITH AREAS OF DENSE FOG FORMING. UPDATE ISSUED AT 855 PM EDT TUE MAY 13 2014 CLUSTERS OF SHOWERS AND THUNDERSTORMS MOVED TO THE NORTH ACROSS THE AREA. SOME OF THESE REACHED SEVERE LIMITS...PRODUCING SMALL HAIL AND SOME WIND DAMAGE. THE LAST OF THE COLD POOL RAINS ARE GRADUALLY DOWN ACROSS NORTHEAST KENTUCKY...WITH A FEW MORE CELLS OCCURRING ACROSS FAR EASTERN KENTUCKY. EXPECT CONVECTION TO WIND DOWN THROUGH 10 PM. POCKETS OF HEAVIER RAINFALL AND LOWER DEW POINT DEPRESSIONS HEADING INTO THE EVENING WILL LIKELY LEAD TO SOME FOG DEVELOPMENT...SO HIGHLIGHTED THIS A BIT MORE IN THE FORECAST. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 345 PM EDT TUE MAY 13 2014 AS OF MID AFTERNOON...A RIDGE OF HIGH PRESSURE WAS CENTERED OFF THE SOUTHEAST US COAST WHILE A TROUGH WAS OVER THE PLAINS TO MS VALLEY REGION AND A RIDGE WAS LOCATED ALONG THE PACIFIC COAST. AT THE SFC...AN AREA OF LOW PRESSURE WAS OVER NW ONTARIO WITH A COLD FRONT EXTENDING SOUTH INTO THE LOWER OH VALLEY REGION. LOCALLY...CONVECTION AT THIS TIME IS PRIMARILY CONFINED TO AREAS CLOSER TO LAKE CUMBERLAND AND DOWN IN THE TN VALLEY...THOUGH ISOLATED CONVECTION WAS OCCURRING OUTSIDE OF THESE AREAS. OVER THE NEXT FEW HOURS...THE CONVECTION WILL CONTINUE TO MOVE NORTH NORTHEAST AND GRADUALLY EXIT THE LAKE CUMBERLAND AREA. HOWEVER...SOME OF THE CONVECTION...OR EVENTUAL OUTFLOWS MAY LEAD TO CONVECTION MOVING INTO OR DEVELOPING OVER THE VA BORDER AREA OF BELL...HARLAN AND LETCHER COUNTY AREA. ALSO...A BOUNDARY THAT CURRENTLY IS NEAR A SANDY HOOK TO JKL TO MIDDLESBORO AND THEN EAST INTO NORTHEAST TN BORDER CONTINUES TO MOVE TO THE NORTH AND EAST. THIS MAY ALSO BE A FOCUS FOR CONVECTION INTO THE EVENING. WITH THE REGION IN ADVANCE OF THE COLD FRONT AND IN THE WARM SECTOR SOME ISOLATED CONVECTION CANNOT BE RULED OUT OVERNIGHT...BUT ACTIVITY SHOULD BE MINIMAL FOR MOST OF...IF NOT THE ENTIRE NIGHT. MANY OF THE SHORT TERM MODELS HAVE CONVECTION POSSIBLY ENCROACHING ON THE AREA LATE TONIGHT AND OPTED FOR SOME SLIGHT CHANCE POPS LATE. ALSO...TONIGHT INTO WEDNESDAY...A SHORTWAVE THAT IS NOW WORKING INTO THE SOUTHERN PLAINS REGION WILL APPROACH THE MS AND TN VALLEY AND NEAR THE MID MS AND LOWER OH VALLEY BY WED EVENING. THIS WILL LEAD TO SFC LOW PRESSURE DEVELOPING ALONG THE BOUNDARY AND TRACK TOWARD THE OH...KY AND IN TRI STATE AREA BY 0Z THU. THIS LOW WILL TRACK TOWARD THE WESTERN END OF LAKE ERIE BY THE END OF THE PERIOD. THIS WILL GRADUALLY LEAD TO MORE FORCING FOR ASCENT AND MORE FOCUSED CONVECTION BY THE LAST 12 HOURS OF THE PERIOD. MODEL FORECAST SOUNDINGS ALSO INDICATE INSTABILITY WILL BE MODERATE AGAIN TOMORROW AFTERNOON AND EVENING AS THE MID LEVEL SHORTWAVE TROUGH APPROACHES AND SFC LOW DEVELOPS. THE FORECAST DEEP LAYER SHEAR IS ALSO FORECAST TO BE GREATER THAN TODAY...BUT ONLY MODEST TO MODERATE...ENOUGH FOR MORE ORGANIZATION...AND GREATER INTENSITY AND COVERAGE WHEN COMBINED WITH INSTABILITY SPC HAS PLACED THE WESTERN PART OF THE CWA IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS FOR WEDNESDAY...AND GUSTY WINDS WOULD APPEAR TO BE THE PRIMARY THREAT AND WITH FREEZING LEVELS ALSO GRADUALLY LOWERING WITH THE APPROACH OF THE MID LEVEL SHORTWAVE SOME HAIL MIGHT ALSO BE POSSIBLE. THIS IS ALREADY HIGHLIGHTED IN THE HWO. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 305 PM EDT TUE MAY 13 2014 THE MODELS WERE ONCE AGAIN IN GOOD AGREEMENT IN THE LONG TERM. THE CONSENSUS VIEW BETWEEN THE ECMWF AND GFS MODELS ARE FOR A LARGE AREA OF LOW PRESSURE TO MOVE ACROSS THE GREAT LAKES REGION AND EVENTUALLY INTO NEW ENGLAND. A SURFACE COLD FRONT TRAILING FROM THIS LOW WILL PROVIDE THE INITIAL TRIGGER FOR SHOWERS AND THUNDERSTORMS ON THURSDAY. MOISTURE FROM THE GULF OF MEXICO STREAMING NORTH AHEAD OF THE FRONT WILL PROVIDE THE FUEL FOR THIS PRECIPITATION. ONCE THE FRONT MOVES THROUGH THE AREA THURSDAY NIGHT...AN AREA OF LOW PRESSURE ALOFT WILL BEGIN TO INFLUENCE OUR AREA AS IT MOVES SLOWLY SOUTHEASTWARD OUT OF THE WESTERN GREAT LAKES REGION. THIS SYSTEM WILL HAVE VERY LIMITED MOISTURE TO WORK AND IS THEREFORE EXPECTED TO BRING ONLY ISOLATED RAIN SHOWERS TO THE EASTERN CONUS THROUGH SATURDAY NIGHT. A MUCH COOLER AND DRIER AIR MASS IS THEN EXPECTED TO SETTLE OVER THE REGION THROUGH THE FIRST OF NEXT WEEK...AS A LARGE AREA OF CANADIAN HIGH PRESSURE MOVES INTO PLACE. THIS MUCH COOLER AIR WILL LEAD TO WELL BELOW NORMAL TEMPERATURES THROUGHOUT THE PERIOD...WITH DAILY HIGHS IN THE 60S AND NIGHTLY LOWS IN THE 40S AREA WIDE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 129 AM EDT WED MAY 14 2014 TOUGH AVIATION PERIOD AS WE WILL HAVE SHOWERS AND STORMS MOVING ACROSS THE AREA AT TIMES OVER THE NEXT 24 TO 36 HOURS. FOG POTENTIAL IS QUESTIONABLE TONIGHT AS CLOUDS CONTINUE TO EXPAND ACROSS THE AREA. IF THIS TREND CONTINUES...WE MAY NOT SEE VISIBILITIES COME DOWN AS EARLIER EXPECTED. WE ALSO HAVE ADDITIONAL SHOWERS AND STORMS PUSHING IN FROM THE SOUTH...AND COULD LIMIT THE FOG POTENTIAL AS WELL. OTHERWISE...ISOLATED/SCATTERED SHOWERS AND STORMS LOOKS LIKELY MAINLY WEST OF KJKL THROUGH THE DAY. AS A COLD FRONT PUSHES ACROSS THE AREA TONIGHT...WE WILL SEE A PERIOD OF SHOWERS AND STORMS FOR ALL AREAS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...JP LONG TERM...AR AVIATION...KAS
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
358 AM CDT WED MAY 14 2014 .SYNOPSIS... SURFACE COLD FRONT NEARING NORTHWESTERN ZONES...BUT COOLER AIR STILL LAGGING A BIT BEHIND. ISOLATED SHOWERS BEGINNING TO POP UP OVER COASTAL AREAS OF SE LA AND ALSO OVER GULF WATERS EAST OF THE MS RIVER. TEMPS GENERALLY SITTING IN THE LOWER 70S WITH DEWPOINTS IN THE UPPER 60S AND LOWER 70S. && .DISCUSSION... COLD FRONT WILL SLOWLY MOVE THROUGH THE LOCAL AREA TODAY AS DEEP UPPER TROUGH SLIDES TOWARD THE MISSISSIPPI VALLEY. PLENTY OF MOISTURE WITH ADDED LIFT ALONG AND AHEAD OF THE FRONT SHOULD LEAD RESULT IN SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE REGION. BEST INSTABILITY AND FORCING LOOK TO BE NORTH AND EAST OF LOCAL AREA...SO RISK OF SEVERE WEATHER IS LOW...BUT A FEW ISOLATED STORMS COULD BECOME SEVERE THIS AFTERNOON WITH THE MAIN THUNDERSTORM THREATS BEING STRONG/DAMAGING WIND GUSTS AND FREQUENT LIGHTNING. RISK WILL BE HIGHEST ACROSS FAR NORTHEASTERN ZONES WHERE SPC CONTINUES TO INDICATE A SLIGHT RISK OF SEVERE WEATHER MAINLY FOR PIKE AND WALTHALL COUNTIES. STILL LOOKS LIKE A BROKEN SQUALL LINE WILL DEVELOP ALONG THE FRONT AT SOME POINT... THOUGH WHETHER THAT HAPPENS OVER THE LOCAL AREA OR EAST OF THE LOCAL AREA IS A BIT UNCERTAIN. BOTH NCEP WRF AND LATEST HRRR RUNS INDICATE SOME POTENTIAL THAT THE LINE WILL BEGIN TO SOLIDIFY OVER EASTERN ZONES...WITH THE NCEP WRF A BIT MORE AGGRESSIVE THAN THE HRRR. SHOULD ALSO MENTION THAT THERE IS AT LEAST SOME POTENTIAL FOR LOCALLY HEAVY RAINFALL ACROSS EASTERN ZONES WHERE PW VALUES ARE FORECAST TO APPROACH 2 INCHES BY THIS AFTERNOON. THESE VALUES ARE SIMILAR TO WHAT WAS SEEN LAST WEEK AND RAINFALL RATES COULD EASILY TOP 2 INCHES PER HOUR IN SOME OF THE HEAVIER STORMS. THAT BEING SAID...WE COULD START TO SEE SOME PONDING ISSUES IN THE USUAL LOW LYING AND POOR DRAINAGE AREAS. RAIN CHANCES GRADUALLY TAPER OFF FROM WEST TO EAST TONIGHT AS THE UPPER TROUGH AXIS FINALLY SLIDES THROUGH THE LOCAL AREA AND STRONG COLD AIR ADVECTION TAKES HOLD OF THE AREA. LOWS TONIGHT FORECAST TO DROP INTO THE UPPER 40S NORTHWEST TO MID 50S SOUTHEAST...WHICH IS ROUGHLY 25 DEGREES LOWER THAN TEMPERATURES WILL BE THIS MORNING. COOL AND DRY HIGH PRESSURE CONTINUES TO BUILD INTO THE AREA DURING THE DAY TOMORROW AND WILL REMAIN IN PLACE FOR A DAY OR TWO...WITH TEMPERATURES REMAINING BELOW NORMAL THROUGH AT LEAST FRIDAY. THE STRONG COLD AIR ADVECTION WILL RESULT IN BREEZY CONDITIONS TONIGHT AND TOMORROW...ESPECIALLY ACROSS AREAS SOUTH OF THE TIDAL LAKES. DOESN/T LOOK LIKE WE/LL MEET WIND ADVISORY CRITERIA AT THIS TIME...BUT IT COULD GET CLOSE RIGHT ALONG THE SOUTH SHORE OF LAKE PONTCHARTRAIN. SHOULD ALSO MENTION THAT STRONG NORTHERLY WINDS OVER LAKE PONTCHARTRAIN COULD PUSH SOME WATER UP ONTO LAKESHORE DRIVE OUTSIDE OF LEVEE PROTECTION. FOR THAT REASON WILL BE ISSUING A COASTAL FLOOD ADVISORY FOR ORLEANS PARISH THAT WILL BE LIKELY BE IN EFFECT FROM 6PM THIS EVENING THROUGH NOON TOMORROW. GOOD NEWS IS THAT THE STRONGEST WINDS WILL COINCIDE WITH LOW TIDE...SO IMPACTS SHOULD BE MINIMAL. SLOW MODERATION OF THE AIR MASS BEGINS ON SATURDAY AS THE SURFACE HIGH SHIFTS EASTWARD AND AN ONSHORE COMPONENT TO THE WIND RETURNS. DESPITE INCREASE IN MOISTURE AND WARMING AFTERNOON TEMPERATURES... AMPLIFIED UPPER LEVEL RIDGING WILL TAKE HOLD OF THE AREA BY MONDAY AND SUBSIDENCE ALOFT SHOULD KEEP A LID ON CONVECTIVE POTENTIAL. SHOULD BE BACK TO WARM AND MUGGY BY MIDWEEK. && .AVIATION... EXPECT VFR TO MVFR CONDITIONS TO PREVAIL THROUGH THE FORECAST PERIOD. SHOWERS AND THUNDERSTORMS REMAIN VERY ISOLATED OVERNIGHT AND MAINLY ACROSS THE THE WESTERN PORTIONS OF THE FORECAST AREA POSSIBLY AFFECTING KBTR...KMCB AND KMSY. AS A RESULT...WILL MAINTAIN VICINITY SHOWERS THROUGH AT LEAST 15Z. THERE IS A CHANCE FOR SOME LIGHT PATCHY FOG TO DEVELOP NEAR DAYBREAK AT MCB AND HUM. A COLD FRONT WILL MOVE THROUGH THE AREA TODAY AND COVERAGE WILL INCREASE AT 15Z THROUGH 00Z THURSDAY. LOOKS FOR TEMP/PREVAILING TSRA GROUPS DURING THIS TIME AS THE CONVECTION TRACK FROM WEST TO EAST TODAY AND TAPERING AFTER 00Z THURSDAY. && .MARINE... SOUTHEAST FLOW HAS EASED IN ADVANCE OF A COLD FRONT. THE COLD FRONT WILL LIKELY TRACK ACROSS THE COASTAL WATERS FROM WEST TO EAST THIS AFTERNOON AND EVENING. STRONG OFFSHORE FLOW WILL DEVELOP IN THE WAKE OF THE AFOREMENTIONED COLD FRONT LATE THIS AFTERNOON AND CONTINUE THROUGH THURSDAY. AFTER THE FRONTAL PASSAGE...STRONG COLD AIR ADVECTION WILL CAUSE THICKNESS LAYER 1000-700MB TO DECREASE AROUND 50M OVER UPPER 70S WATER TEMPS. AS A RESULT...BOUNDARY LAYER WINDS OF 20 TO 25 KNOTS WILL MIXED DOWN TO THE WARM SEA SURFACE LATE THIS AFTERNOON THROUGH THURSDAY EVENING. THEREFORE...A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR ALL COASTAL WATERS 6PM TODAY THROUGH 6PM THURSDAY. THE WINDS WILL GRADUALLY DIMINISH ON FRIDAY. && .DECISION SUPPORT... DSS CODE...BLUE. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...SLURRY SUPPORT MONITORING RIVER FLOODING 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 TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 75 47 71 45 / 50 20 10 0 BTR 75 50 74 49 / 50 20 10 0 ASD 80 52 73 49 / 60 30 10 0 MSY 80 56 73 56 / 60 20 10 0 GPT 80 54 74 51 / 70 30 10 0 PQL 82 55 74 46 / 70 40 10 0 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. MS...NONE. GM...SMALL CRAFT ADVISORY FROM 6 PM WEDNESDAY TO 6 PM THURSDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND MISSISSIPPI SOUND. && $$ AVIATION/MARINE...18 REST OF DISCUSSION...95/DM
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
533 AM EDT WED MAY 14 2014 .SYNOPSIS... HIGH PRESSURE WILL SLIDE EAST TODAY AND RETURN FLOW SETS UP OVER THE AREA. AN UNSETTLED WEATHER PATTERN WILL BE IN PLACE THURSDAY THROUGH EARLY NEXT WEEK AS A SLOW-MOVING COLD FRONT APPROACHES OVER THE WEEKEND...THEN LOW PRESSURE DEVELOPS ALONG IT NEARBY AND LINGERS INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATE...WAA SHRA HAVE EXPANDED IN COVERAGE IN A LINE ROUGHLY PARALLEL TO THE NH/ME BORDER. THESE WILL CONTINUE TO MOVE EWD THIS MORNING AND HAVE ADJUSTED POP ACCORDINGLY. PREVIOUS DISCUSSION...CONVECTIVE COMPLEX OVER NY STATE IS SLOWLY SAGGING S AND DRYING UP AS IT MOVES EWD. THIS TREND SUPPORTS HI- RES MODEL SOLUTIONS LIKE THE HRRR/RAP. HOWEVER A WING OF WAA WILL BRUSH THE CWFA THIS MORNING...AS UPPER RIDGE AXIS SLIDES EWD. THESE SHRA ARE ELEVATED IN NATURE AND THERE REMAINS SOME LINGERING DRY AIR AT THE SFC ESPECIALLY ACROSS WRN ME. WILL LEAVE ANY MENTION OF PCPN AT SCT OR ISOLD ATTM. AS RETURN FLOW SETS UP TODAY BROAD WAA WILL SUPPORT A MIX OF SUN AND CLOUDS. TEMPS WILL MODERATE SOME THOUGH...ESPECIALLY ACROSS NH. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... FOCUS TONIGHT WILL BE ON DEVELOPING MARINE FOG/STRATUS. MESOSCALE MODELS AND MOS GUIDANCE BOTH SUGGEST IT WILL OCCUR. ATTM IR SATELLITE SHOWS A LARGE AREA OF STRATUS OVER THE MID ATLANTIC...SLOWLY EXPANDING NWD. LATEST HRRR HAS A VERY GOOD HANDLE ON THIS AREA AND CLOUD HEIGHTS WITHIN IT. IN THE NEXT SEVERAL HOURS IT DEVELOPS STRATUS IN THE GULF OF ME. ATTM STRATUS IS ABSENT HERE ON SATELLITE IMAGERY. FEEL THAT IT MAY BE SLIGHTLY OVERAGGRESSIVE DUE TO THE COLD WATER TEMPS IN THE GULF. HOWEVER DURING THE DAY AS WINDS TURN MUCH MORE SLY OVER A LONGER FETCH TO OUR S THIS AREA OF FOG/STRATUS SHOULD DEVELOP QUICKLY. CURRENT FORECAST IS FOR THIS AREA TO MOVE ONSHORE BY OR SHORTLY AFTER 00Z. SOME SHALLOW LIFT COUPLED WITH DRY AIR ALOFT WILL LIKELY LEAD TO SOME DZ THROUGHOUT THE NIGHT AS WELL. DIURNAL HEATING AND INCREASING SLY WINDS SHOULD HELP TO PARTIALLY MIX OUT THE STRATUS DURING THE DAY THU. THIS HEATING COULD ALSO LEAD TO SCT AFTERNOON SHRA. ON THE NRN AND WRN FRINGES OF THE MARINE LAYER MARGINAL LAPSE RATES WILL BE PRESENT ALOFT. NAM BUFKIT SOUNDINGS YIELD CAPE AOA 500 J/KG FOR THESE AREAS...SO WILL MAINTAIN SOME MENTION OF THUNDER DURING THE DAY THU. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... A SLOW MOVING FRONTAL BOUNDARY WILL APPROACH NEW ENGLAND THURSDAY NIGHT FROM THE WEST. WAVES OF LOW PRESSURE ALONG THIS FRONT WILL SLOW THE PROGRESS OF THIS SYSTEM AS IT BUMPS INTO THE UPPER LEVEL RIDGE WITH TIME. AHEAD OF THE PRECIPITATION...EXPECT WARM AND MUGGY CONDITIONS ON FRIDAY AWAY FROM THE COAST. ALONG THE SHORELINE...IT WILL BE A COOLER DUE TO AN ONSHORE FLOW. PATCHY DRIZZLE AND FOG IS LIKELY AS WELL...MAINLY DURING THE MORNING AND EVENING HOURS. 00Z MODEL SUITE HAS SOME DISAGREEMENT ON THE TIMING OF THE BAND OF PRECIPITATION ASSOCIATED WITH THE SLOW MOVING COLD FRONT. THE EURO IS THE FASTEST WITH THIS PRECIPITATION...WHILE THE GFS HOLDS MOISTURE TO THE WEST...KEEPING MUCH OF OUR FORECAST AREA DRY FRIDAY NIGHT...WITH THE EXCEPTION OF SOUTHWEST NEW HAMPSHIRE. WILL ALLOW FOR A COMPROMISE IN TERMS OF THE TIMING OF THE PRECIP. SHOWERS MAY BE LOCALLY HEAVY SATURDAY MORNING...MAINLY OVER NEW HAMPSHIRE AS DEEP LAYERED MOISTURE ENTERS THE REGION FROM WELL OFF THE EASTERN SEABOARD. A WEAK AREA OF LOW PRESSURE SLOWLY DEVELOPS ALONG THIS FRONT OFF THE NEW ENGLAND COASTLINE LATE IN THE WEEKEND AND EARLY NEXT WEEK. THIS WILL ALLOW A PERSISTENT COOL AND MOIST MARITIME FLOW OVER THE REGION WITH AT LEAST SCATTERED SHOWERS ON A DAILY BASIS. PREFER THE GFS SOLUTION WITH QPF THROUGH THIS EXTENDED TIME RANGE...BRINGING UP TO THREE INCHES OF RAIN FOR THE FOOTHILLS OF MAINE AND THE HIGHER TERRAIN OVER CENTRAL/NORTHERN NEW HAMPSHIRE. && .AVIATION /10Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM...VFR CONDITIONS GENERALLY EXPECTED TODAY. WILL HAVE TO WATCH FOR BKN MVFR DECK OF CLOUDS TO DEVELOP WITH DIURNAL HEATING...AS SUGGESTED BY SOME SHORT TERM GUIDANCE. THEN FOCUS TURNS TO MARINE FOG/STRATUS AS WARM...MOIST AIR RETURNS NWD. MESOSCALE MODELS ARE IN AGREEMENT THAT IT WILL FORM AROUND OR SHORTLY AFTER 00Z THIS EVENING. EXPECTED WIDESPREAD IFR OR LOWER FOR COASTAL TERMINALS. LONG TERM...IFR OR LOWER CONDITIONS EXPECTED AGAIN THU NIGHT IN MARINE FOG/STRATUS. SOME IMPROVEMENT DURING THE DAY FRI BEFORE COLD FNT APPROACHES WILL DETERIORATING CIGS/VSBYS AND POSSIBLE HEAVY RNFL INTO SAT. && .MARINE... SHORT TERM...DEEP SLY FLOW EXPECTED TO DEVELOP TODAY AS HIGH PRES SHIFTS E OF THE WATERS. LATE THU SEAS ON THE OUTER WATERS WILL BEGIN TO BUILD TOWARDS 5 FT. EXPECT VSBY RESTRICTIONS IN FOG BEGINNING TONIGHT. LONG TERM...WINDS GENERALLY EXPECTED TO REMAIN BELOW SCA THRESHOLDS...THOUGH SUSTAINED SLY FLOW WILL BRING SEAS ABOVE 5 FT FOR AN EXTENDED PERIOD THROUGH THE WEEKEND. && .FIRE WEATHER... DEEP SOUTHERLY FLOW DEVELOPING TODAY WILL KEEP MOISTURE ON THE RISE THROUGH THE WEEKEND. DESPITE WARMING TEMPERATURES...RISING MOISTURE WILL ALSO KEEP RELATIVE HUMIDITY VALUES IN THE MODERATE RANGE DURING THE DAY AND HIGH AT NIGHT. THE BEST CHANCE FOR WETTING RAINS WILL BE LATE FRIDAY INTO SATURDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ LEGRO/JC
AREA FORECAST DISCUSSION
NWS CARIBOU ME
357 AM EDT WED MAY 14 2014 .SYNOPSIS... HIGH PRESSURE WILL MOVE EAST OF THE REGION TODAY AS A WARM FRONT LIFTS NORTHWARD ACROSS THE REGION. LOW PRESSURE AND A COLD FRONT WILL MOVE VERY SLOWLY TOWARD REGION FROM THE QUEBEC PROVINCE LATE IN THE WEEK WHILE HIGH PRESSURE HOLDS ACROSS THE WESTERN ATLANTIC. && .NEAR TERM /THROUGH TONIGHT/... LATEST RADAR SHOWED A BAND OF SHOWERS IN ASSOCIATION WITH THE APPROACHING 850 MB WARM FRONT WORKING EAST FROM QUEBEC. LATEST MESOSCALE GUIDANCE INCLUDING THE HRRR AND RAP SHOW THIS BAND WILL MOVE NORTHEAST ACROSS THE REGION THIS MORNING. THE BEST CHANCE FOR SHOWERS WILL BE ACROSS NORTHERN AREAS THIS MORNING WITH LESSER CHANCES DOWNEAST. THIS BAND OF SHOWERS WILL MOVE EAST INTO NEW BRUNSWICK BY LATE MORNING OR EARLY AFTERNOON WITH MOSTLY CLOUDY/PARTLY SUNNY SKIES IN ITS WAKE. HIGHS TODAY WILL BE DEPENDANT ON HOW MUCH SUN WE SEE LATER TODAY. THE BEST CHANCES WILL BE BACK ACROSS WESTERN AREAS LATER THIS AFTERNOON AND THIS MAY ALLOW TEMPERATURES TO RISE WELL INTO THE 60S. IT WILL BE COOLER ACROSS DOWNEAST MAINE ESPECIALLY THE IMMEDIATE COAST WHERE A COOLER ONSHORE FLOW WILL KEEP TEMPERATURES ONLY IN THE LOW TO MID 50S. THE 500MB RIDGE AXIS WILL MOVE EAST OF THE REGION TONIGHT. SOUTH WINDS AROUND THE HIGH TO OUR EAST WILL BRING THE POTENTIAL FOR LOW CLOUDS AND FOG ESPECIALLY ACROSS DOWNEAST MAINE. BUFKIT SOUNDINGS CERTAINLY APPEAR FAVORABLE FOR LOW STRATUS DEVELOPMENT DOWNEAST LATER TONIGHT. OTHER THAN SOME PATCHY LIGHT DRIZZLE DOWNEAST IT SHOULD REMAIN DRY TONIGHT. LOWS TONIGHT WILL BE MAINLY IN THE MID TO UPPER 40S WITH UPPER 40S TO LOW 50S DOWNEAST. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... HIGH AMPLITUDE UPPER RIDGE OVR THE WRN ATLC/ERN US/ERN CAN W/ DIGGING UPPER TROF ACROSS THE WRN GRT LAKES AND MISSISSIPPI RVR VLY AT THE START OF THE SHORT TERM PD THU AM... AT THE SFC...LOW PRES OVR THE WRN OH VLY/SRN GRT LAKES REGION W/ BROAD SRLY FLOW ACROSS OUR REGION W/ SFC HIGH PRES JUST E OF OUR AREA. STRONG UPPER RIDGE ACROSS THE REGION WILL KEEP SYSTEM TO OUR W INITIALLY AT BAY W/ DRY BUT MILD BUT RATHER HUMID CONDS ACROSS OUR REGION THRU FRI. TEMPS WILL BE ON THE TRICKY SIDE AS OVERALL UPPER HGTS AND SFC-1000 THICKNESS SUGGESTS TEMPS QUITE WARM DURING THIS PD BUT SRLY FLOW OFF THE COLD ATLC WATERS WILL LIKELY HAVE SOME MODERATING INFLUENCES ON OVERALL TEMPS SO HAVE GONE CONSERVATIVE FOR NOW. FOG MAY ALSO BE AN ISSUE SPCLY ACROSS SRN AREAS W/ THE WARM AND HUMID SRLY FLOW OFF THE COLD ATLC WATERS... OVERALL HOWEVER...A VERY SPRING-LIKE PTRN THU/FRI W/ NO MAJOR ISSUES EXPECTED. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE STRONG UPPER RIDGE WHICH PROTECTED OUR REGION THRU FRI W/ DRY AND MILD CONDS WILL GRADUALLY SHIFT EWRD ALLOWING THE WX SYSTEM W OF THE AREA TO GRADUALLY BECOME MORE OF A FACTOR FOR OUR AREA... ATTM...THE LONGER RANGE MODEL GUIDANCE PLACES A SLOW MOVG FRONTAL SYSTEM ACROSS WRN NEW ENGLAND BY ERLY SAT AM W/ PRECIP BEGINNING TO OVERSPREAD OUR WRN AREAS. THIS FRONTAL BNDRY CONTS TO SLOWLY PUSH EWRD THEN STALL OVR THE AREA AS THE UPPER SUPPORTING TROF IS FCST TO CUTOFF WELL S OF THE AREA W/ A RATHER MOIST AND UNSETTLED ENERLY FLOW TO DVLP ACROSS OUR AREA AND PERSIST THRU THE REMAINDER OF LONG TERM PD. MAIN UNCERTAINTY DURING THIS PD WILL BE THE EXTEND THAT THE CUTOFF TO OUR S WILL BE ABLE TO KEEP DEEPER MOISTURE ACROSS OUR AREA. PLACEMENT MAY BE FAR ENUF S THAT ONLY OCNL SHOWERS DOMINATE THE WX PTRN AND ANY FURTHER SRN SHIFT COULD RENDER SPCLY NRN AREAS MAINLY DRY. GIVEN THESE UNCERTAINTIES...WILL CARRY MOSTLY JUST CHC POPS THRU THE PD. TEMPS WILL START A LITTLE ABV SEASONAL NORMS AND THEN COOL TO NR OR JUST SLIGHTLY BLO SEASONAL NORMS DEPENDING ON CLD CVR AND PRECIP. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... NEAR TERM: VFR CONDITIONS EARLY THIS MORNING WILL GIVE WAY TO SOME MVFR CONDITIONS IN SHOWERS ACROSS NORTHERN AREAS THIS MORNING. VFR/MVFR BKN-OVC CIGS ARE POSSIBLE THIS AFTERNOON. MVFR/IFR IS EXPECTED TO DEVELOP LATE TONIGHT DEVELOPING LOW CLOUDS AND PATCHY FOG ESPECIALLY KBGR/KBHB WHERE LIFR CONDITIONS ARE POSSIBLE AFTER 06Z. SHORT TERM: A WARM AND INCREASINGLY HUMID SRLY FLOW WILL LEAD TO INCREASING CHCS FOR FOG SPCLY SRN AREAS DURING THE OVRNGT/ERLY AM HRS W/ THESE CONDS LIKELY INTO SUN. OTHERWISE VFR CONDS ARE ANTICIPATED. && .MARINE... NEAR TERM: WIND/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH TONIGHT. VISIBILITY WILL BE REDUCED TO 1 TO 3 NM IN AREAS OF FOG LATE TONIGHT. SHORT TERM: WNDS/SEAS EXPECTED TO REMAIN BLO SCA LEVELS THRU THE PD THO SEAS MAY APPROACH 5 FT LATE IN THE PD IN PERSISTENT SRLY FLOW. ALSO EXPECT FOG TO BECOME RATHER PREVALENT W/ THE WARM AND HUMID SRLY FLOW OVR THE COLD ATLC WATERS... && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...DUDA SHORT TERM...KHW LONG TERM...KHW AVIATION...DUDA/KHW MARINE...DUDA/KHW
AREA FORECAST DISCUSSION
NWS GRAY ME
321 AM EDT WED MAY 14 2014 .SYNOPSIS... HIGH PRESSURE WILL SLIDE EAST TODAY AND RETURN FLOW SETS UP OVER THE AREA. AN UNSETTLED WEATHER PATTERN WILL BE IN PLACE THURSDAY THROUGH EARLY NEXT WEEK AS A SLOW-MOVING COLD FRONT APPROACHES OVER THE WEEKEND...THEN LOW PRESSURE DEVELOPS ALONG IT NEARBY AND LINGERS INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... CONVECTIVE COMPLEX OVER NY STATE IS SLOWLY SAGGING S AND DRYING UP AS IT MOVES EWD. THIS TREND SUPPORTS HI-RES MODEL SOLUTIONS LIKE THE HRRR/RAP. HOWEVER A WING OF WAA WILL BRUSH THE CWFA THIS MORNING...AS UPPER RIDGE AXIS SLIDES EWD. THESE SHRA ARE ELEVATED IN NATURE AND THERE REMAINS SOME LINGERING DRY AIR AT THE SFC ESPECIALLY ACROSS WRN ME. WILL LEAVE ANY MENTION OF PCPN AT SCT OR ISOLD ATTM. AS RETURN FLOW SETS UP TODAY BROAD WAA WILL SUPPORT A MIX OF SUN AND CLOUDS. TEMPS WILL MODERATE SOME THOUGH...ESPECIALLY ACROSS NH. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... FOCUS TONIGHT WILL BE ON DEVELOPING MARINE FOG/STRATUS. MESOSCALE MODELS AND MOS GUIDANCE BOTH SUGGEST IT WILL OCCUR. ATTM IR SATELLITE SHOWS A LARGE AREA OF STRATUS OVER THE MID ATLANTIC...SLOWLY EXPANDING NWD. LATEST HRRR HAS A VERY GOOD HANDLE ON THIS AREA AND CLOUD HEIGHTS WITHIN IT. IN THE NEXT SEVERAL HOURS IT DEVELOPS STRATUS IN THE GULF OF ME. ATTM STRATUS IS ABSENT HERE ON SATELLITE IMAGERY. FEEL THAT IT MAY BE SLIGHTLY OVERAGGRESSIVE DUE TO THE COLD WATER TEMPS IN THE GULF. HOWEVER DURING THE DAY AS WINDS TURN MUCH MORE SLY OVER A LONGER FETCH TO OUR S THIS AREA OF FOG/STRATUS SHOULD DEVELOP QUICKLY. CURRENT FORECAST IS FOR THIS AREA TO MOVE ONSHORE BY OR SHORTLY AFTER 00Z. SOME SHALLOW LIFT COUPLED WITH DRY AIR ALOFT WILL LIKELY LEAD TO SOME DZ THROUGHOUT THE NIGHT AS WELL. DIURNAL HEATING AND INCREASING SLY WINDS SHOULD HELP TO PARTIALLY MIX OUT THE STRATUS DURING THE DAY THU. THIS HEATING COULD ALSO LEAD TO SCT AFTERNOON SHRA. ON THE NRN AND WRN FRINGES OF THE MARINE LAYER MARGINAL LAPSE RATES WILL BE PRESENT ALOFT. NAM BUFKIT SOUNDINGS YIELD CAPE AOA 500 J/KG FOR THESE AREAS...SO WILL MAINTAIN SOME MENTION OF THUNDER DURING THE DAY THU. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... A SLOW MOVING FRONTAL BOUNDARY WILL APPROACH NEW ENGLAND THURSDAY NIGHT FROM THE WEST. WAVES OF LOW PRESSURE ALONG THIS FRONT WILL SLOW THE PROGRESS OF THIS SYSTEM AS IT BUMPS INTO THE UPPER LEVEL RIDGE WITH TIME. AHEAD OF THE PRECIPITATION...EXPECT WARM AND MUGGY CONDITIONS ON FRIDAY AWAY FROM THE COAST. ALONG THE SHORELINE...IT WILL BE A COOLER DUE TO AN ONSHORE FLOW. PATCHY DRIZZLE AND FOG IS LIKELY AS WELL...MAINLY DURING THE MORNING AND EVENING HOURS. 00Z MODEL SUITE HAS SOME DISAGREEMENT ON THE TIMING OF THE BAND OF PRECIPITATION ASSOCIATED WITH THE SLOW MOVING COLD FRONT. THE EURO IS THE FASTEST WITH THIS PRECIPITATION...WHILE THE GFS HOLDS MOISTURE TO THE WEST...KEEPING MUCH OF OUR FORECAST AREA DRY FRIDAY NIGHT...WITH THE EXCEPTION OF SOUTHWEST NEW HAMPSHIRE. WILL ALLOW FOR A COMPROMISE IN TERMS OF THE TIMING OF THE PRECIP. SHOWERS MAY BE LOCALLY HEAVY SATURDAY MORNING...MAINLY OVER NEW HAMPSHIRE AS DEEP LAYERED MOISTURE ENTERS THE REGION FROM WELL OFF THE EASTERN SEABOARD. A WEAK AREA OF LOW PRESSURE SLOWLY DEVELOPS ALONG THIS FRONT OFF THE NEW ENGLAND COASTLINE LATE IN THE WEEKEND AND EARLY NEXT WEEK. THIS WILL ALLOW A PERSISTENT COOL AND MOIST MARITIME FLOW OVER THE REGION WITH AT LEAST SCATTERED SHOWERS ON A DAILY BASIS. PREFER THE GFS SOLUTION WITH QPF THROUGH THIS EXTENDED TIME RANGE...BRINGING UP TO THREE INCHES OF RAIN FOR THE FOOTHILLS OF MAINE AND THE HIGHER TERRAIN OVER CENTRAL/NORTHERN NEW HAMPSHIRE. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM...VFR CONDITIONS GENERALLY EXPECTED TODAY. WILL HAVE TO WATCH FOR BKN MVFR DECK OF CLOUDS TO DEVELOP WITH DIURNAL HEATING...AS SUGGESTED BY SOME SHORT TERM GUIDANCE. THEN FOCUS TURNS TO MARINE FOG/STRATUS AS WARM...MOIST AIR RETURNS NWD. MESOSCALE MODELS ARE IN AGREEMENT THAT IT WILL FORM AROUND OR SHORTLY AFTER 00Z THIS EVENING. EXPECTED WIDESPREAD IFR OR LOWER FOR COASTAL TERMINALS. LONG TERM...IFR OR LOWER CONDITIONS EXPECTED AGAIN THU NIGHT IN MARINE FOG/STRATUS. SOME IMPROVEMENT DURING THE DAY FRI BEFORE COLD FNT APPROACHES WILL DETERIORATING CIGS/VSBYS AND POSSIBLE HEAVY RNFL INTO SAT. && .MARINE... SHORT TERM...DEEP SLY FLOW EXPECTED TO DEVELOP TODAY AS HIGH PRES SHIFTS E OF THE WATERS. LATE THU SEAS ON THE OUTER WATERS WILL BEGIN TO BUILD TOWARDS 5 FT. EXPECT VSBY RESTRICTIONS IN FOG BEGINNING TONIGHT. LONG TERM...WINDS GENERALLY EXPECTED TO REMAIN BELOW SCA THRESHOLDS...THOUGH SUSTAINED SLY FLOW WILL BRING SEAS ABOVE 5 FT FOR AN EXTENDED PERIOD THROUGH THE WEEKEND. && .FIRE WEATHER... DEEP SOUTHERLY FLOW DEVELOPING TODAY WILL KEEP MOISTURE ON THE RISE THROUGH THE WEEKEND. DESPITE WARMING TEMPERATURES...RISING MOISTURE WILL ALSO KEEP RELATIVE HUMIDITY VALUES IN THE MODERATE RANGE DURING THE DAY AND HIGH AT NIGHT. THE BEST CHANCE FOR WETTING RAINS WILL BE LATE FRIDAY INTO SATURDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ LEGRO/JC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
529 AM EDT WED MAY 14 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 527 AM EDT WED MAY 14 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A HIGH AMPLITUDE PATTERN OVER NAMERICA...CONSISTING OF A RIDGE ALONG THE W COAST AND A TROF EXTENDING FROM NRN CANADA TO TX. WITHIN THE TROF...THE NRN STREAM FEATURES A MIDLEVEL LOW OVER NRN ONTARIO TO THE SW OF HUDSON BAY... BUT NRN STREAM ENERGY IS DIVING S ALONG THE SASKATCHEWAN/MANITOBA BORDER REGION. IN THE SRN PART OF THE TROF...A SHORTWAVE IS OVER TX/OK. EXACTLY HOW THE AFOREMENTIONED SOUTHWARD DIVING NRN STREAM ENERGY INTERACTS WITH THE SRN PLAINS SHORTWAVE WILL BE KEY TO THE WEATHER IN THE NEXT COUPLE OF DAYS...INCLUDING THE POTENTIAL FOR VERY LATE SEASON ACCUMULATING SNOW WHICH IS LOOKING A BIT MORE LIKELY FOR SOME AREAS. DRIER AIR MASS HAS PUSHED INTO THE FCST AREA OVER THE LAST 12-18HRS. WHILE 00Z KGRB SOUNDING SHOWED DRY LOW TO MID LEVELS...UPSTREAM KINL SOUNDING SHOWED MOISTURE EXTENDING UP TO AROUND 700MB. SOME OF THIS MOISTURE WILL PROBABLY MANIFEST ITSELF AS HIGHER BASED SCT-BKN CU/STRATOCU THIS AFTN...ESPECIALLY INLAND FROM LAKE SUPERIOR. ISOLD/SCT -SHRA WERE COMMON UPSTREAM YESTERDAY...BUT WITH DRY BOUNDARY LAYER AND LOW-LEVEL FLOW HERE TRENDING ANTICYCLONIC RATHER THAN CYCLONIC AS IT WAS YESTERDAY WHERE THE SHRA WERE OCCURRING... DON`T EXPECT ANY -SHRA/SPRINKLES IN THE FCST AREA TODAY. LAKE BREEZES WILL DEVELOP OFF LAKE SUPERIOR AND LAKE MICHIGAN TODAY... KEEPING LAKESIDE LOCATIONS CHILLY THIS AFTN. INLAND...DEEP MIXING TO TOWARD 750MB ON FCST SOUNDINGS YIELDS MAX TEMPS IN THE MID TO UPPER 50S. MAY SEE A FEW READINGS AROUND 60F OVER THE SCNTRL. DWPTS WILL MIX OUT INTO THE MID 20S THIS AFTN...RESULTING IN MIN RH DOWN AROUND 30PCT IN THE INTERIOR W HALF THIS AFTN. FAIRLY LIGHT WINDS/MOIST GROUND WILL LIMIT FIRE WX CONCERNS. NRN STREAM ENERGY DIVING S INTO THE NRN PLAINS TODAY WILL CONTINUE S INTO IA TONIGHT. THIS WILL HELP PULL SRN PLAINS SHORTWAVE N INTO IL BY SUNRISE WED WITH ORGANIZING SFC LOW LIFTING INTO ERN IN. PUSH OF WAA/ISENTROPIC ASCENT AND DEEP LAYER FORCING AHEAD OF WAVE ALONG WITH STRONG MOISTURE TRANSPORT WILL LEAD TO EXPANDING PCPN SHIELD LIFTING N INTO THE GREAT LAKES TONIGHT. NRN FRINGE OF PCPN MAY REACH THE FAR E AND SE FCST AREA AROUND SUNRISE THU. INCLUDED SCHC POPS IN THAT AREA. WETBULB ZERO HEIGHTS/1000-850MB THICKNESS SUGGEST THERE COULD BE SOME SNOWFLAKES MIXED IN WITH THE RAIN IF PCPN DOES IN FACT ARRIVE LATE TONIGHT. OTHERWISE...EXPECT INCREASING CLOUDS TONIGHT WITH LOW TEMPS IN THE 30S. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 447 AM EDT WED MAY 14 2014 ...MODELS TRENDING BACK TO STRONGER SYSTEM/ACCUMULATING SNOW TO END THE WEEK... HIGHLY AMPLIFIED UPPER LEVEL PATTERN IN PLACE LATE THIS WEEK AS UPPER TROUGH WITH H5 HEIGHTS OF 2-3 STANDARD DEVIATIONS BLO CLIMO CENTERED OVER THE MIDDLE MISSISSIPPI RIVER VALLEY. STILL HINTS THAT THIS UPPER TROUGH BECOMES CLOSED OFF BY FRIDAY AS IT CROSSES THE WESTERN GREAT LAKES. COUPLE OF SHORTWAVES LIFTING NEARLY DUE NORTH ON LEAD FLANK OF THE UPPER LOW MAY LOOKS TO BRING AT LEAST A BRIEF SHOT OF WINTRY PRECIP TO UPPER LAKES LATER THURSDAY INTO FRIDAY. PORTION OF TROUGH MOVES TOWARD MID ATLANTIC THIS WEEKEND WHILE HEIGHTS SLOWLY BEGIN TO REBOUND OVER THE GREAT LAKES. RIDGING ALOFT MAKES RETURN TO UPPER LAKES REGION EARLY NEXT WEEK BUT SINCE THE LOW-LEVELS REMAIN UNDER FIRM INFLUENCE OF SFC HIGH AND WORKED OVER CP AIRMASS...ONLY MODERATE WARMING WILL OCCUR BY NEXT WEEK WITH TEMPS LIKELY REMAINING AT OR BLO NORMAL. PRIMARY FOCUS IN THE LONG TERM IS ON THE SYSTEM AND POSSIBLE WINTRY PRECIPITATION THURSDAY INTO FRIDAY. APPEARS THAT THE 00Z ECMWF RUN FROM TUE 5/13 WAS AN ABERATION...AS WITH THE 12Z RUN ON TUE 5/13 THE UPPER LOW IS CLOSED OFF AGAIN...DRAWING THE PRIMARY SHORTWAVE AND SFC WAVE BACK WEST AGAIN SPREADING QPF OVER MAINLY EAST THIRD OF CWA THROUGH 00Z FRIDAY. LATEST SET OF MODEL RUNS NOT SET ON ANY ONE IDEA THOUGH AS ESSENTIALLY WE CONTINUE TO SEE ALL THE DIFFERENT ENSEMBLE MEMBERS WITH THIS SYSTEM. EVEN WITH THAT UNCERTAINTY THOUGH...ENOUGH OF TREND EMERGING TO INCREASE POPS SIGNIFICANTLY THURSDAY/THURSDAY NIGHT/FRIDAY. NAM FARTHEST WEST WITH THE INITIAL SHORTWAVE AND PV ANAMOLY AND ASSOCIATED QPF ON THURSDAY. FARTHEST EAST IDEA IS UKMET WHICH FOCUSES MOST OF ITS FORCING/MOISTURE WITH THE SHORTWAVE OVER FAR EASTERN UPR MICHIGAN AND TO THE EAST. LATEST GFS AND GEM ALONG WITH 12Z ECMWF ARE IN BETWEEN THESE TWO EXTREMES AND FOCUS WHAT LOOKS LIKE AREA OF TROWAL/DEFORMATION PRECIP OVER THE EAST HALF OF CWA THROUGH 00Z FRIDAY. PTYPE FOR THIS INITIAL WAVE OF PRECIP LIKELY WOULD BE MOSTLY A MIX OF RAIN/SNOW...THOUGH HIGHER TERRAIN AREAS OF NCNTRL UPR MICHIGAN COULD SEE JUST SNOW BY LATER AFTN. LATER THURSDAY NIGHT INTO FRIDAY THERE ARE HINTS FROM THE ECMWF AND ESPECIALLY THE GFS/NAM THAT MID-LEVEL FRONTOGENESIS H7-H6 IMPACTS LK SUPERIOR AND NORTH CENTRAL AND PERHAPS NORTHWEST CWA AT LEAST FRIDAY MORNING AS TEMP GRADIENT STRENGTHENS AT H7 DUE TO PERSISTENT COLD/WARM ADVECTION ALONG AXIS OVER CNTRL LK SUPERIOR. MAY BE GETTING LOST IN THE DETAILS HERE...BUT FN CONVERGENCE IS DECENT AND THERE IS ALSO FS VECTOR CONVERGENCE THAT SUGGESTS AN AREA OF WIDESPREAD PRECIPITATION WOULD PIVOT ACROSS THOSE PORTIONS OF THE CWA. ADDED LIFT WILL BE PROVIDED BY NNW WINDS UPSLOPING OVER HIGHER TERRAIN OF NW AND NCNTRL CWA. AGAIN...THIS IS ONE MODEL RUN OF MANY DIFFERENT TAKES ON THIS SYSTEM...BUT GIVEN UPPER LOW DEEPENING AND SHORTWAVES WRAPPING INTO THE BACK SIDE OF THE UPPER LOW...THE GENERAL IDEA OF ENHANCED FRONTOGENESIS OCCURRING HAS SOME MERIT. UNCERTAINTY OF THAT FEATURES PLACEMENT IS MAIN ISSUE FROM INTRODUCING THAT KIND OF DETAIL TO FORECAST ATTM. TEMP GRADIENT ALOFT WEAKENS IN THE AFTN...SO INTENSITY OF MID-LEVEL LIFT/FGEN SHOULD DO LIKEWISE. LINGERING LOW-LEVEL MOISTURE AND UPSLOPE LIFTING SHOULD KEEP LIGHT PRECIP GOING INTO THE AFTN THOUGH. BASED ON LIFT OVER THE AREA WITH H85 TEMPS WELL BLO ZERO AND 1000-850MB THICKNESSES BLO 1300M...AND NOT MUCH OF ABOVE FREEZING NEAR SFC LAYER SHOWING UP IN THE SOUNDINGS...PTYPE THURSDAY NIGHT INTO FRIDAY MORNING FOR THE MOST PART WILL BE SNOW ACROSS MUCH OF CWA. BY FRIDAY AFTN...BLYR WARMING WILL ALLOW FOR MIX OF RAIN/SNOW SHOWERS OVER LOWER ELEVATIONS OF CWA...ESPECIALLY EASTERN HALF. NOW THE MAIN QUESTION TURNS TO SNOW AMOUNTS. AS WITH ANY SNOW THIS LATE IN THE SEASON THE MAIN HURDLES OF WARM GROUND TEMPS...SNOW INTENSITY...TIME OF DAY...ALL HAVE TO BE CONSIDERED. BUT...AT LEAST IN THESE LATITUDES IT IS NOT UNHEARD OF AT ALL TO SEE SIGNIFICANT LATE SEASON SNOWS. LOCAL RECORDS/OTHER ACCOUNTS INCLUDE A SEVERAL INCH SNOWSTORM THAT OCCURED OVER HIGHER TERRAIN OF NORTH CENTRAL UPR MICHIGAN EARLY IN JUNE OF 1945...AND THERE HAVE BEEN OTHERS THAN HAVE OCCURRED IN LATE MAY EVEN AS FAR SOUTH AS WISCONSIN. THIS SYSTEM WILL HAVE TO BE WATCHED...AS IF THE REVERSAL OF TRACK MAJORITY OF MODELS ARE SHOWING COMES TO FRUITION...THERE IS A HIGHER POTENTIAL TO SEE SEVERAL INCHES OF WET SNOW OVER PARTS OF UPR MICHIGAN. LOOKING AT THE FACTORS MENTIONED ABOVE...GOOD PART OF SNOW OCCURS THURSDAY NIGHT INTO FRIDAY MORNING...SO THE INSOLATION WILL BE MINIMAL FACTOR IN CUTTING DOWN ON AMOUNTS...AND SNOW MAY FALL AT GOOD CLIP LATER THURSDAY NIGHT INTO FRIDAY...ESPECIALLY IF THE FGEN AND DEFORMATION AREA INCREASES AS SOME MODELS INDICATE. BEST GUESS TO START IS PROBABILITIES ARE PRETTY HIGH THAT AT LEAST A FEW INCHES OF WET SNOW WILL OCCUR OVER THE HIGHER TERRAIN OF THE KEWEENAW PENINSULA...PERHAPS AS FAR WEST AS THE PORCUPINE MOUNTAINS...AND ALSO OVER THE HIGHER TERRAIN OF BARAGA AND MARQUETTE COUNTIES. THESE AREAS WILL ALSO HAVE THE ADDED BENEFIT OF NW WINDS PROVIDING UPSLOPE LIFT. NOTEABLE IS THAT SOME OF THE ENSEMBLE OUTPUT FROM THE 03Z SREF MEMBERS TRENDED HIGHER THAN PREVIOUS RUNS...INDICATING MUCH MORE SNOW...WITH A FEW MEMBERS EVEN PRINTING OUT AMOUNTS OVER 6 INCHES...WITH ISOLATED MEMBERS OVER 10 INCHES. HOWEVER...SREF OUTPUT IS SEEMING TO KEY ON LARGER SCALE FORCING IMPACTING MOST OF UPR MICHIGAN AS IT SHOWS SEVERAL INCHES OF SNOW AS FAR SOUTH AS KIMT AND EAST AS KERY. SREF MEAN SHOWS 2-4 INCHES OVER THE HIGHER TERRAIN AREAS NEAR LK SUPERIOR AND PERHAPS AN INCH OR TWO IN THAT IMT TO ERY CORRIDOR. ENOUGH EVIDENCE TO PUT MENTION OF THIS SYSTEM INTO THE HAZARDOUS WEATHER OUTLOOK AND EHWO GRAPHICS. AND THEN WE WILL WAIT TO SEE WHAT THE LATER MODEL RUNS INDICATE. SYSTEM...HOWEVER STRONG IT ENDS UP BEING...WILL LEAVE A WELL ESTABLISHED CP AIRMASS OVER THE UPPER GREAT LAKES ON SATURDAY. HOWEVER...INLAND AREAS WILL MIX TO AROUND H85 SO TEMPS WILL PUSH INTO THE 50S DEGREES THERE. RIDGE AT THE SFC MOVING OVERHEAD WILL SUPPORT LAKE BREEZES WHICH WILL PACK A PUNCH NEAR LK SUPERIOR /KEEPING TEMPS IN THE LOWER 40S/ AS WATERS OFFSHORE ARE STILL VERY COLD OR EVEN ICE COVERED IN SOME AREAS. SFC RIDGE SLOWLY SLIDES ACROSS INTO MONDAY. TEMPS SUNDAY AND MONDAY WILL MODERATE INLAND WITH READINGS WELL INTO THE 60S BY MONDAY. ONSHORE WINDS WILL CONTINUE TO KEEP GREAT LAKES SHORES MUCH COOLER. THE COOL/DRY AIRMASS AND THE RIDGE WILL ALLOW NIGHTTIME LOWS TO DIP BELOW FREEZING FOR MANY SPOTS INLAND SATURDAY NIGHT THROUGH MONDAY NIGHT. NEAR THE SHORE...READINGS WILL LIKELY STAY JUST ABOVE FREEZING. NEXT CHANCE OF RAIN...YES JUST RAIN...ARRIVES LATER MONDAY AND MORE SO INTO TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 119 AM EDT WED MAY 14 2014 VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD AS DRY HIGH PRES MOVES INTO THE REGION. SOME DIURNAL CU ARE EXPECTED WITH BKN VFR CIGS. A WEAKER PRES GRADIENT WILL ALLOW A LAKE BREEZE TO DEVELOP AT KSAW WITH NNE WINDS THIS AFTERNOON. OTHERWISE...WRLY WINDS WILL PREVAIL AT IWD AND CMX. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 527 AM EDT WED MAY 14 2014 EXPECT WESTERLY WINDS UP TO 15-25KT OVER THE W HALF OF LAKE SUPERIOR TODAY AND MOSTLY UNDER 20KT OVER THE E HALF. WINDS WILL DIMINISH TONIGHT UNDER WEAKENING PRES GRADIENT. ATTENTION THEN TURNS TO SFC LOW PRES THAT WILL LIFT N ACROSS LAKE HURON THU AND THEN TO JAMES BAY BY FRI NIGHT. TIGHTENING PRES GRADIENT WILL RESULT IN INCREASING WINDS THU...MAINLY OVER THE E HALF OF LAKE SUPERIOR. NORTHERLY WINDS THU NIGHT WILL REACH 20-30KT OVER THE E HALF. THE STRONGER WINDS OVER THE ERN LAKE WILL BEGIN TO DIMINISH LATER FRI AS THE LOW MOVES FARTHER AWAY. WINDS WILL BE MUCH LIGHTER OVER WRN LAKE SUPERIOR THU AND FRI. WEAK PRES GRADIENT OVER THE WEEKEND WILL LEAD TO WINDS UNDER 20KT. && .HYDROLOGY... ISSUED AT 527 AM EDT WED MAY 14 2014 PERIODS OF RAIN AND SNOW ARE EXPECTED TO DEVELOP THU AND CONTINUE INTO FRI. SOME LIGHT PCPN WILL LINGER ON INTO SAT. RIGHT NOW...PCPN AMOUNTS ARE EXPECTED TO BE LIGHT ENOUGH SO THAT THERE IS LITTLE IMPACT ON AREA RIVERS/STREAMS...AND SINCE NO SIGNIFICANT PCPN IS IN THE OFFING THRU EARLY NEXT WEEK...EXPECT ALL RIVERS TO HAVE AN OVERALL DOWNWARD TREND OVER THE NEXT SEVERAL DAYS. HOWEVER...THERE ARE SOME INDICATIONS THAT PCPN AMOUNTS MAY BE HEAVIER THAN CURRENTLY EXPECTED THU/FRI OVER NRN UPPER MI. IF SO...HIGHER RIVER LEVELS WILL BE SUSTAINED AND COULD RISE SOME FRI INTO SAT. THE MAIN RIVERS OF CONCERN ARE OVER THE W HALF OF UPPER MI... INCLUDING THE STURGEON RIVER AT CHASSELL AND THE MICHIGAMME RIVER AT REPUBLIC...WITCH LAKE...AND CRYSTAL FALLS. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...JLB MARINE...ROLFSON HYDROLOGY...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
450 AM EDT WED MAY 14 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 353 PM EDT TUE MAY 13 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE TROF OVER CENTRAL NAMERICA BTWN RDGS ALONG THE W COAST AND ANOTHER STRETCHING FM QUEBEC THRU THE SE CONUS. THE INTERACTION BTWN A SHRTWV RIDING NNEWD IN THE STRONG SSW FLOW ALF TO THE E OF THE TROF AXIS AND RIBBON OF DEEPER MSTR REPRESENTED BY THE 12Z GRB RAOB RESULTED IN SOME SHRA OVER MAINLY THE ERN CWA INTO EARLY AFTN...BUT MID LVL DRYING UNDER THE JET SURGE OF PRIMARY SHRTWV LIFTING THRU NW ONTARIO IS BRINGING DRY WX TO THE ENTIRE CWA LATER THIS AFTN. HOWEVER...QUITE A BIT OF LOWER CLD IS LINGERING ESPECIALLY OVER THE WRN CWA WITH ABUNDANT LLVL MSTR BLO SHARPENING SUBSIDENCE INVRNS SHOWN ON THE 12Z INL/MPX RAOBS BEING ADVECTED TO THE E IN GUSTY SFC W FLOW TO THE S OF DEPARTING SFC LO IN NW ONTARIO. MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON LO CLD TRENDS/ IMPACT ON TEMPS. TNGT...DESPITE THE ABUNDANT LLVL MSTR...INCRSG ACYC NATURE OF THE LLVL FLOW WITH CLOSER APRCH OF SFC HI PRES IN THE CENTRAL PLAINS AND LOSS OF DAYTIME HEATING/MIXING SHOULD PROMOTE CLRG OF THE LO CLD. WITH LOSS OF DAYTIME HEATING AND WEAKENING PRES GRADIENT...THE GUSTY W WINDS WL DIMINISH THIS EVNG. UPSTREAM LO TEMPS THIS MRNG AND MOS FCSTS INDICATE MIN TEMPS WL DIP INTO THE 30S AS H85 TEMPS FALL TO BTWN 0 AND -2C BY 12Z WED. WED...SFC HI PRES RDG/LLVL ACYC FLOW WL RESULT IN LIGHTER WINDS/DRY WX AS PWAT FALLS TO 0.25-0.50 INCH. EXPECT SOME SC TO DVLP AWAY FM THE STABILIZING/COOLING INFLUENCE OF THE LKS WITH DAYTIME HEATING/ MIXING IN THE PRESENCE OF LINGERING CHILLY H85 TEMPS. THERE WL BE SOME INCRS IN HI CLDS OVER AT LEAST THE SE PORTION OF THE CWA AS ANOTHER SHRTWV RIDING NE OUT OF THE BASE OF DEEP TROF IN THE CENTRAL CONUS MOVES TOWARD THE GREAT LKS. DEEP MIXING TO H75 ON NAM/GFS FCST SDNGS YIELD MAX TEMPS RISING INTO THE MID/UPR 50S AWAY FM THE COOLING INFLUENCE OF THE LKS. ALTHOUGH THE DEEP MIXING WL ALLOW DEWPTS TO MIX OUT INTO THE LO-MID 20S/MIN RH TO FALL TOWARD 25 PCT... FAIRLY LGT WINDS/MOIST GROUND WL LIMIT ANY FIRE WX CONCERNS. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 447 AM EDT WED MAY 14 2014 ...MODELS TRENDING BACK TO STRONGER SYSTEM/ACCUMULATING SNOW TO END THE WEEK... HIGHLY AMPLIFIED UPPER LEVEL PATTERN IN PLACE LATE THIS WEEK AS UPPER TROUGH WITH H5 HEIGHTS OF 2-3 STANDARD DEVIATIONS BLO CLIMO CENTERED OVER THE MIDDLE MISSISSIPPI RIVER VALLEY. STILL HINTS THAT THIS UPPER TROUGH BECOMES CLOSED OFF BY FRIDAY AS IT CROSSES THE WESTERN GREAT LAKES. COUPLE OF SHORTWAVES LIFTING NEARLY DUE NORTH ON LEAD FLANK OF THE UPPER LOW MAY LOOKS TO BRING AT LEAST A BRIEF SHOT OF WINTRY PRECIP TO UPPER LAKES LATER THURSDAY INTO FRIDAY. PORTION OF TROUGH MOVES TOWARD MID ATLANTIC THIS WEEKEND WHILE HEIGHTS SLOWLY BEGIN TO REBOUND OVER THE GREAT LAKES. RIDGING ALOFT MAKES RETURN TO UPPER LAKES REGION EARLY NEXT WEEK BUT SINCE THE LOW-LEVELS REMAIN UNDER FIRM INFLUENCE OF SFC HIGH AND WORKED OVER CP AIRMASS...ONLY MODERATE WARMING WILL OCCUR BY NEXT WEEK WITH TEMPS LIKELY REMAINING AT OR BLO NORMAL. PRIMARY FOCUS IN THE LONG TERM IS ON THE SYSTEM AND POSSIBLE WINTRY PRECIPITATION THURSDAY INTO FRIDAY. APPEARS THAT THE 00Z ECMWF RUN FROM TUE 5/13 WAS AN ABERATION...AS WITH THE 12Z RUN ON TUE 5/13 THE UPPER LOW IS CLOSED OFF AGAIN...DRAWING THE PRIMARY SHORTWAVE AND SFC WAVE BACK WEST AGAIN SPREADING QPF OVER MAINLY EAST THIRD OF CWA THROUGH 00Z FRIDAY. LATEST SET OF MODEL RUNS NOT SET ON ANY ONE IDEA THOUGH AS ESSENTIALLY WE CONTINUE TO SEE ALL THE DIFFERENT ENSEMBLE MEMBERS WITH THIS SYSTEM. EVEN WITH THAT UNCERTAINTY THOUGH...ENOUGH OF TREND EMERGING TO INCREASE POPS SIGNIFICANTLY THURSDAY/THURSDAY NIGHT/FRIDAY. NAM FARTHEST WEST WITH THE INITIAL SHORTWAVE AND PV ANAMOLY AND ASSOCIATED QPF ON THURSDAY. FARTHEST EAST IDEA IS UKMET WHICH FOCUSES MOST OF ITS FORCING/MOISTURE WITH THE SHORTWAVE OVER FAR EASTERN UPR MICHIGAN AND TO THE EAST. LATEST GFS AND GEM ALONG WITH 12Z ECMWF ARE IN BETWEEN THESE TWO EXTREMES AND FOCUS WHAT LOOKS LIKE AREA OF TROWAL/DEFORMATION PRECIP OVER THE EAST HALF OF CWA THROUGH 00Z FRIDAY. PTYPE FOR THIS INITIAL WAVE OF PRECIP LIKELY WOULD BE MOSTLY A MIX OF RAIN/SNOW...THOUGH HIGHER TERRAIN AREAS OF NCNTRL UPR MICHIGAN COULD SEE JUST SNOW BY LATER AFTN. LATER THURSDAY NIGHT INTO FRIDAY THERE ARE HINTS FROM THE ECMWF AND ESPECIALLY THE GFS/NAM THAT MID-LEVEL FRONTOGENESIS H7-H6 IMPACTS LK SUPERIOR AND NORTH CENTRAL AND PERHAPS NORTHWEST CWA AT LEAST FRIDAY MORNING AS TEMP GRADIENT STRENGTHENS AT H7 DUE TO PERSISTENT COLD/WARM ADVECTION ALONG AXIS OVER CNTRL LK SUPERIOR. MAY BE GETTING LOST IN THE DETAILS HERE...BUT FN CONVERGENCE IS DECENT AND THERE IS ALSO FS VECTOR CONVERGENCE THAT SUGGESTS AN AREA OF WIDESPREAD PRECIPITATION WOULD PIVOT ACROSS THOSE PORTIONS OF THE CWA. ADDED LIFT WILL BE PROVIDED BY NNW WINDS UPSLOPING OVER HIGHER TERRAIN OF NW AND NCNTRL CWA. AGAIN...THIS IS ONE MODEL RUN OF MANY DIFFERENT TAKES ON THIS SYSTEM...BUT GIVEN UPPER LOW DEEPENING AND SHORTWAVES WRAPPING INTO THE BACK SIDE OF THE UPPER LOW...THE GENERAL IDEA OF ENHANCED FRONTOGENESIS OCCURRING HAS SOME MERIT. UNCERTAINTY OF THAT FEATURES PLACEMENT IS MAIN ISSUE FROM INTRODUCING THAT KIND OF DETAIL TO FORECAST ATTM. TEMP GRADIENT ALOFT WEAKENS IN THE AFTN...SO INTENSITY OF MID-LEVEL LIFT/FGEN SHOULD DO LIKEWISE. LINGERING LOW-LEVEL MOISTURE AND UPSLOPE LIFTING SHOULD KEEP LIGHT PRECIP GOING INTO THE AFTN THOUGH. BASED ON LIFT OVER THE AREA WITH H85 TEMPS WELL BLO ZERO AND 1000-850MB THICKNESSES BLO 1300M...AND NOT MUCH OF ABOVE FREEZING NEAR SFC LAYER SHOWING UP IN THE SOUNDINGS...PTYPE THURSDAY NIGHT INTO FRIDAY MORNING FOR THE MOST PART WILL BE SNOW ACROSS MUCH OF CWA. BY FRIDAY AFTN...BLYR WARMING WILL ALLOW FOR MIX OF RAIN/SNOW SHOWERS OVER LOWER ELEVATIONS OF CWA...ESPECIALLY EASTERN HALF. NOW THE MAIN QUESTION TURNS TO SNOW AMOUNTS. AS WITH ANY SNOW THIS LATE IN THE SEASON THE MAIN HURDLES OF WARM GROUND TEMPS...SNOW INTENSITY...TIME OF DAY...ALL HAVE TO BE CONSIDERED. BUT...AT LEAST IN THESE LATITUDES IT IS NOT UNHEARD OF AT ALL TO SEE SIGNIFICANT LATE SEASON SNOWS. LOCAL RECORDS/OTHER ACCOUNTS INCLUDE A SEVERAL INCH SNOWSTORM THAT OCCURED OVER HIGHER TERRAIN OF NORTH CENTRAL UPR MICHIGAN EARLY IN JUNE OF 1945...AND THERE HAVE BEEN OTHERS THAN HAVE OCCURRED IN LATE MAY EVEN AS FAR SOUTH AS WISCONSIN. THIS SYSTEM WILL HAVE TO BE WATCHED...AS IF THE REVERSAL OF TRACK MAJORITY OF MODELS ARE SHOWING COMES TO FRUITION...THERE IS A HIGHER POTENTIAL TO SEE SEVERAL INCHES OF WET SNOW OVER PARTS OF UPR MICHIGAN. LOOKING AT THE FACTORS MENTIONED ABOVE...GOOD PART OF SNOW OCCURS THURSDAY NIGHT INTO FRIDAY MORNING...SO THE INSOLATION WILL BE MINIMAL FACTOR IN CUTTING DOWN ON AMOUNTS...AND SNOW MAY FALL AT GOOD CLIP LATER THURSDAY NIGHT INTO FRIDAY...ESPECIALLY IF THE FGEN AND DEFORMATION AREA INCREASES AS SOME MODELS INDICATE. BEST GUESS TO START IS PROBABILITIES ARE PRETTY HIGH THAT AT LEAST A FEW INCHES OF WET SNOW WILL OCCUR OVER THE HIGHER TERRAIN OF THE KEWEENAW PENINSULA...PERHAPS AS FAR WEST AS THE PORCUPINE MOUNTAINS...AND ALSO OVER THE HIGHER TERRAIN OF BARAGA AND MARQUETTE COUNTIES. THESE AREAS WILL ALSO HAVE THE ADDED BENEFIT OF NW WINDS PROVIDING UPSLOPE LIFT. NOTEABLE IS THAT SOME OF THE ENSEMBLE OUTPUT FROM THE 03Z SREF MEMBERS TRENDED HIGHER THAN PREVIOUS RUNS...INDICATING MUCH MORE SNOW...WITH A FEW MEMBERS EVEN PRINTING OUT AMOUNTS OVER 6 INCHES...WITH ISOLATED MEMBERS OVER 10 INCHES. HOWEVER...SREF OUTPUT IS SEEMING TO KEY ON LARGER SCALE FORCING IMPACTING MOST OF UPR MICHIGAN AS IT SHOWS SEVERAL INCHES OF SNOW AS FAR SOUTH AS KIMT AND EAST AS KERY. SREF MEAN SHOWS 2-4 INCHES OVER THE HIGHER TERRAIN AREAS NEAR LK SUPERIOR AND PERHAPS AN INCH OR TWO IN THAT IMT TO ERY CORRIDOR. ENOUGH EVIDENCE TO PUT MENTION OF THIS SYSTEM INTO THE HAZARDOUS WEATHER OUTLOOK AND EHWO GRAPHICS. AND THEN WE WILL WAIT TO SEE WHAT THE LATER MODEL RUNS INDICATE. SYSTEM...HOWEVER STRONG IT ENDS UP BEING...WILL LEAVE A WELL ESTABLISHED CP AIRMASS OVER THE UPPER GREAT LAKES ON SATURDAY. HOWEVER...INLAND AREAS WILL MIX TO AROUND H85 SO TEMPS WILL PUSH INTO THE 50S DEGREES THERE. RIDGE AT THE SFC MOVING OVERHEAD WILL SUPPORT LAKE BREEZES WHICH WILL PACK A PUNCH NEAR LK SUPERIOR /KEEPING TEMPS IN THE LOWER 40S/ AS WATERS OFFSHORE ARE STILL VERY COLD OR EVEN ICE COVERED IN SOME AREAS. SFC RIDGE SLOWLY SLIDES ACROSS INTO MONDAY. TEMPS SUNDAY AND MONDAY WILL MODERATE INLAND WITH READINGS WELL INTO THE 60S BY MONDAY. ONSHORE WINDS WILL CONTINUE TO KEEP GREAT LAKES SHORES MUCH COOLER. THE COOL/DRY AIRMASS AND THE RIDGE WILL ALLOW NIGHTTIME LOWS TO DIP BELOW FREEZING FOR MANY SPOTS INLAND SATURDAY NIGHT THROUGH MONDAY NIGHT. NEAR THE SHORE...READINGS WILL LIKELY STAY JUST ABOVE FREEZING. NEXT CHANCE OF RAIN...YES JUST RAIN...ARRIVES LATER MONDAY AND MORE SO INTO TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 119 AM EDT WED MAY 14 2014 VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD AS DRY HIGH PRES MOVES INTO THE REGION. SOME DIURNAL CU ARE EXPECTED WITH BKN VFR CIGS. A WEAKER PRES GRADIENT WILL ALLOW A LAKE BREEZE TO DEVELOP AT KSAW WITH NNE WINDS THIS AFTERNOON. OTHERWISE...WRLY WINDS WILL PREVAIL AT IWD AND CMX. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 353 PM EDT TUE MAY 13 2014 EXPECT W WINDS UP TO 30 KKTS ON THE SOUTHERN FLANK OF LO PRES MOVING NEWD THRU ONTARIO...STRONGEST OVER THE NCENTRAL WHERE THE TERRAIN FUNNELS THIS FLOW BETWEEN THE KEWEENAW AND ISLE ROYALE...TO DIMINISH TO UNDER 20-25 KTS TONIGHT WITH THE ARRIVAL OF A WEAKER PRES GRADIENT CLOSER TO APPROACHING HI PRES. WINDS WILL THEN REMAIN UNDER 25 KTS THRU THE REST OF THE FORECAST PERIOD WITH A RELATIVELY WEAK PRES GRADIENT DOMINATING. THERE DOES REMAIN SOME POTENTIAL THAT N WINDS ON THU INTO FRI MAY REACH 25-30 KTS OVER MAINLY THE E HALF OF LAKE SUPERIOR IF A LO PRES SYSTEM LIFTING ACROSS THE GREAT LAKES TRACKS FARTHER TO THE W. THIS SCENARIO DOES NOT APPEAR LIKELY AT THIS TIME. && .HYDROLOGY... ISSUED AT 328 PM EDT TUE MAY 13 2014 THE NEXT CHANCE OF PRECIPITATION LOOKS TO FALL THURSDAY THROUGH FRIDAY. HOWEVER THE BEST CHANCE OF 0.10IN OR MORE WILL BE OVER THE E THIRD OF UPPER MI. SOME VERY LIGHT SNOW MAY EVEN BE POSSIBLE OVER THE W HALF THURSDAY NIGHT INTO FRIDAY. THE MAIN CONCERNS RIVER WISE WILL CONTINUE TO BE OVER THE W HALF OF UPPER MI. THEY INCLUDE THE STURGEON RIVER AT CHASSELL...WHICH IS SLOWLY FALLING...AND THE MICHIGAMME AT REPUBLIC...WITCH LAKE...AND CRYSTAL FALLS...WHICH LOOK TO HAVE ALL CRESTED AS WELL AND ARE SLOWLY ON THEIR WAY DOWN. RIVER FLOWS WILL LIKELY REMAIN HIGH THROUGH THE REST OF THE WEEK. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...JLB MARINE...KC HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
120 AM EDT WED MAY 14 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 353 PM EDT TUE MAY 13 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE TROF OVER CENTRAL NAMERICA BTWN RDGS ALONG THE W COAST AND ANOTHER STRETCHING FM QUEBEC THRU THE SE CONUS. THE INTERACTION BTWN A SHRTWV RIDING NNEWD IN THE STRONG SSW FLOW ALF TO THE E OF THE TROF AXIS AND RIBBON OF DEEPER MSTR REPRESENTED BY THE 12Z GRB RAOB RESULTED IN SOME SHRA OVER MAINLY THE ERN CWA INTO EARLY AFTN...BUT MID LVL DRYING UNDER THE JET SURGE OF PRIMARY SHRTWV LIFTING THRU NW ONTARIO IS BRINGING DRY WX TO THE ENTIRE CWA LATER THIS AFTN. HOWEVER...QUITE A BIT OF LOWER CLD IS LINGERING ESPECIALLY OVER THE WRN CWA WITH ABUNDANT LLVL MSTR BLO SHARPENING SUBSIDENCE INVRNS SHOWN ON THE 12Z INL/MPX RAOBS BEING ADVECTED TO THE E IN GUSTY SFC W FLOW TO THE S OF DEPARTING SFC LO IN NW ONTARIO. MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON LO CLD TRENDS/ IMPACT ON TEMPS. TNGT...DESPITE THE ABUNDANT LLVL MSTR...INCRSG ACYC NATURE OF THE LLVL FLOW WITH CLOSER APRCH OF SFC HI PRES IN THE CENTRAL PLAINS AND LOSS OF DAYTIME HEATING/MIXING SHOULD PROMOTE CLRG OF THE LO CLD. WITH LOSS OF DAYTIME HEATING AND WEAKENING PRES GRADIENT...THE GUSTY W WINDS WL DIMINISH THIS EVNG. UPSTREAM LO TEMPS THIS MRNG AND MOS FCSTS INDICATE MIN TEMPS WL DIP INTO THE 30S AS H85 TEMPS FALL TO BTWN 0 AND -2C BY 12Z WED. WED...SFC HI PRES RDG/LLVL ACYC FLOW WL RESULT IN LIGHTER WINDS/DRY WX AS PWAT FALLS TO 0.25-0.50 INCH. EXPECT SOME SC TO DVLP AWAY FM THE STABILIZING/COOLING INFLUENCE OF THE LKS WITH DAYTIME HEATING/ MIXING IN THE PRESENCE OF LINGERING CHILLY H85 TEMPS. THERE WL BE SOME INCRS IN HI CLDS OVER AT LEAST THE SE PORTION OF THE CWA AS ANOTHER SHRTWV RIDING NE OUT OF THE BASE OF DEEP TROF IN THE CENTRAL CONUS MOVES TOWARD THE GREAT LKS. DEEP MIXING TO H75 ON NAM/GFS FCST SDNGS YIELD MAX TEMPS RISING INTO THE MID/UPR 50S AWAY FM THE COOLING INFLUENCE OF THE LKS. ALTHOUGH THE DEEP MIXING WL ALLOW DEWPTS TO MIX OUT INTO THE LO-MID 20S/MIN RH TO FALL TOWARD 25 PCT... FAIRLY LGT WINDS/MOIST GROUND WL LIMIT ANY FIRE WX CONCERNS. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 445 PM EDT TUE MAY 13 2014 COOL TEMPERATURES WILL REMAIN THROUGH THE LONG TERM PERIOD...AS THE AREAS IS DOMINATED BY LOW PRESSURE AT 500MB. THE 500MB TROUGH CURRENTLY EXTENDING OVER MUCH OF CENTRAL CANADA AND THE CENTRAL UNITED STATES WILL SLIDE ACROSS ONTARIO AND MN BY 06Z THURSDAY. LOOK FOR A LOW TO DEVELOP OVER THE UPPER GREAT LAKES FROM AROUND 00Z FRIDAY THROUGH AT LEAST FRIDAY...AND THEN SHIFT OFF ACROSS LAKE HURON AND THE LOWER GREAT LAKES SATURDAY AFTERNOON THROUGH SUNDAY. ONE OF THE BIG QUESTIONS THIS PERIOD WAS THE POTENTIAL FOR MIXED PRECIP /RAIN OR SNOW SHOWERS/ FROM THURSDAY EVENING THROUGH SATURDAY MORNING. AN OVERALL DRIER SOLUTION HAS BEEN COMING IN WITH THE 12Z MODEL GUIDANCE. BY 12Z THURSDAY UPPER MI WILL BE IN BETWEEN THE LARGE HIGH PRESSURE OVER S CENTRAL CANADA AND THE N PLAINS...AND THE SFC LOW SURGING N ACROSS OH AND E MI. THE TRACK OF THE LOW IS FARTHEST W OFF THE CANADIAN AND ECMWF...WITH ALL SOLUTIONS KEEPING A WEAK TROUGH OVER CENTRAL AND E UPPER MI THURSDAY-THURSDAY NIGHT...WITH FAVORABLE COOL N-NW WINDS OFF LAKE SUPERIOR AND 850MB TEMPS FALLING TO AROUND -6C. THE WETTEST SOLUTION HAS BEEN THE 18Z NAM CAME IN WITH 0.25IN OF LIQUID OVER E UPPER MI /MAINLY E OF MUNISING/ FROM 18Z THURSDAY-00Z FRIDAY/. HAVE GONE AHEAD WITH A DRIER SCENARIO FOR NOW...BUT KEPT THE POTENTIAL FOR SLIGHT CHANCE RAIN/SNOW SHOWERS. WILL NEED TO WAIT AND SEE ON THIS ONE...AS A LOT CAN HAPPEN BETWEEN NOW AND THURSDAY AFTERNOON. LOOK FOR THE SFC LOW TO EXIT INTO SW QUEBEC THURSDAY NIGHT AS HIGH PRESSURE SLOWLY BUILDS ACROSS THE UPPER GREAT LAKES. LOOK FOR A RETURN TO NEAR NORMAL TEMPERATURES FOR THE END OF THE WEEKEND AND START OF THE NEXT WORK WEEK AS HIGH PRESSURE REMAINS OVERHEAD...AND THE 500MB RIDGE BUILDS IN FROM THE GULF OF MEXICO UP THROUGH THE UPPER GREAT LAKES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 119 AM EDT WED MAY 14 2014 VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD AS DRY HIGH PRES MOVES INTO THE REGION. SOME DIURNAL CU ARE EXPECTED WITH BKN VFR CIGS. A WEAKER PRES GRADIENT WILL ALLOW A LAKE BREEZE TO DEVELOP AT KSAW WITH NNE WINDS THIS AFTERNOON. OTHERWISE...WRLY WINDS WILL PREVAIL AT IWD AND CMX. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 353 PM EDT TUE MAY 13 2014 EXPECT W WINDS UP TO 30 KKTS ON THE SOUTHERN FLANK OF LO PRES MOVING NEWD THRU ONTARIO...STRONGEST OVER THE NCENTRAL WHERE THE TERRAIN FUNNELS THIS FLOW BETWEEN THE KEWEENAW AND ISLE ROYALE...TO DIMINISH TO UNDER 20-25 KTS TONIGHT WITH THE ARRIVAL OF A WEAKER PRES GRADIENT CLOSER TO APPROACHING HI PRES. WINDS WILL THEN REMAIN UNDER 25 KTS THRU THE REST OF THE FORECAST PERIOD WITH A RELATIVELY WEAK PRES GRADIENT DOMINATING. THERE DOES REMAIN SOME POTENTIAL THAT N WINDS ON THU INTO FRI MAY REACH 25-30 KTS OVER MAINLY THE E HALF OF LAKE SUPERIOR IF A LO PRES SYSTEM LIFTING ACROSS THE GREAT LAKES TRACKS FARTHER TO THE W. THIS SCENARIO DOES NOT APPEAR LIKELY AT THIS TIME. && .HYDROLOGY... ISSUED AT 328 PM EDT TUE MAY 13 2014 THE NEXT CHANCE OF PRECIPITATION LOOKS TO FALL THURSDAY THROUGH FRIDAY. HOWEVER THE BEST CHANCE OF 0.10IN OR MORE WILL BE OVER THE E THIRD OF UPPER MI. SOME VERY LIGHT SNOW MAY EVEN BE POSSIBLE OVER THE W HALF THURSDAY NIGHT INTO FRIDAY. THE MAIN CONCERNS RIVER WISE WILL CONTINUE TO BE OVER THE W HALF OF UPPER MI. THEY INCLUDE THE STURGEON RIVER AT CHASSELL...WHICH IS SLOWLY FALLING...AND THE MICHIGAMME AT REPUBLIC...WITCH LAKE...AND CRYSTAL FALLS...WHICH LOOK TO HAVE ALL CRESTED AS WELL AND ARE SLOWLY ON THEIR WAY DOWN. RIVER FLOWS WILL LIKELY REMAIN HIGH THROUGH THE REST OF THE WEEK. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KF AVIATION...JLB MARINE...KC HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
115 AM EDT WED MAY 14 2014 .SYNOPSIS... A FRONTAL BOUNDARY WILL REMAIN IN OUR VICINITY TODAY THROUGH THURSDAY. WHILE MUCH OF THE TIME WILL BE DRY, SCATTERED SHOWERS AND PERHAPS A FEW THUNDERSTORMS WILL BE POSSIBLE. A COLD FRONT WILL SLOWLY MOVE EAST ON FRIDAY WITH A SOAKING RAIN. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... UPDATED AT 115 AM... LARGE CLUSTER OF CONVECTIVE RAIN CONTINUES TO MOVE SLOWLY NORTHEAST ACROSS CENTRAL NY WITH BURSTS OF HEAVY RAIN TRAINING ALONG THE SOUTH EDGE OF THIS SYSTEM FROM THE FINGER LAKES ACROSS NORTHERN CHENANGO COUNTY. DUAL POL RAINFALL ESTIMATES OF OVER 5 INCHES IN PARTS OF YATES COUNTY HAS RESULTED IN SIGNIFICANT FLOODING FOR PARTS OF THAT AREA. WATCHING ANOTHER SMALL CLUSTER OF SHOWERS AND STORMS OVER NORTHWEST PA EARLY THIS MORNING. HOPEFULLY THAT CLUSTER WILL LIFT NORTH AND PASS TO THE WEST OF AREAS THAT ARE GETTING HEAVY RAIN CURRENTLY. THE EXPECTATION FOR THE NEXT SEVERAL HOURS IS FOR SCATTERED SHOWERS AND STORMS TO CONTINUE FROM NW PA NORTHEAST ACROSS THE FINGER LAKES WITH NOTHING MORE THAN ISOLATED SHOWERS FARTHER EAST IN THE MORE STABLE AIRMASS ALONG AND EAST OF I-81. PREVIOUS DISCUSSION IS BELOW. 1015 PM UPDATE...SCATTERED TO NUMEROUS CONVECTION CONTINUES JUST WEST OF BACKDOOR COLD FRONT, PRIMARILY IN THE FINGER LAKES REGION. THIS ACTIVITY IS EXPECTED TO SLOWLY LIFT NORTH AND EAST OVER THE NRN PTN OF THE CWA THROUGH LATE NIGHT. MUCH OF THE WESTERN CATSKILLS, BGM AREA AND NORTHEAST PA WILL REMAIN PRIMARILY DRY AS AIRMASS HERE IS STABLE UNDER COOL SE FLOW. WILL CONTINUE WITH LIKELY POPS OVER FINGER LAKES AND NRN CWA THROUGH 06Z THEN LOWER POPS INTO CHC/SLIGHT CHC FOR REMAINDER OF NIGHT EXCEPT DRY SE FA. 6 PM UPDATE...LATEST LOCAL RADAR IMAGERY SHOWS THE BACKDOOR COLD FRONT ABOUT TO MOVE THROUGH THE LOCAL BGM AREA. THIS FEATURE EXTENDS UP THROUGH THE WESTERN MOHAWK VALLEY AND SOUTH ACROSS THE WYOMING VALLEY. LOCATIONS EAST OF THE FEATURE ARE IN THE LOWER TO MIDDLE 70S WHILE OVER THE CENTRAL SOUTHERN TIER AND FINGER LAKES AREA ITS IN THE LOWER TO MIDDLE 80S. THIS BOUNDARY IS EXPECTED TO REACH THE CENTRAL SOUTHERN TIER AND EASTERN FINGER LAKES BEFORE STALLING AND MOVING BACK EAST. SCATTERED CONVECTION MAY FIRE ALONG THIS BOUNDARY UNTIL EARLY EVENING WHEN CAPE AND LOW LEVEL LAPSE RATES WILL LESSEN. CONVECTION OVER GEORGIAN BAY WHICH IS ASSOCIATED WITH COLD FRONT MAY MOVE INTO THE NRN PTN OF CWA LATE TONIGHT BUT BOUNDARY WILL SLOW OVERNIGHT AND CONVECTION WILL MOVE INTO A MUCH MORE STABLE ENVIRONMENT BY THEN. 3 PM UPDATE... A WEAK WARM FRONT IS ACROSS THE AREA WITH DEWPOINTS IN THE L60S IN THE WEST. AS THE WARM FRONT LIFTS NE WITH A WEAK WAVE A FEW SHOWERS AND MAYBE A TSTORM WILL GET GOING LATE TODAY AND THIS EVE. THE UL RIDGE ALSO MOVES THROUGH CREATING A DEEPER SOUTHERLY FLOW OF WARM AND MOIST AIR INTO THE CWA. WITH THE HIGH DEWPT TEMPS...MIN TEMPS WILL VARY WIDELY FROM U40S EAST TO A60 FAR WEST. DEWPTS DROP AS THE NIGHT GOES ON WITH THE EXIT OF THE WARM FRONT AND THE COLD FRONT NEARLY STATIONARY IN ERN MICIGAN. && .SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/... 3 PM UPDATE... WED AND THU WILL BE SIMILAR TO THE LAST 2 DAYS. WEAK FORCING AND MORE COVERAGE LATE IN THE DAY WITH DIURNAL HEATING. WED WILL BE BETTER THAN THU AS A COLD FRONT MOVES EAST INTO NW NY THEN LIFTS NORTH WED NGT. THU LITTLE FORCING AS WE WAIT FOR THE MAIN SHOW WHICH IS THE COLD FRONT. A SFC LOW WILL MOVE NORTH UP THE MISS VALLEY TO MICHIGAN THEN INTO QUEBEC AHEAD OF A DEEP DIGGING UPPER LEVEL LOW OVER THE MIDWEST. THIS STALLS OVER THE GREAT LAKES BUT KEEPS THE COLD FRONT MOVING THROUGH THE CWA FRIDAY. WITH THE FRONT WILL BE A BAND OF HEAVY RAIN OF WIDESPREAD 1 TO 2 INCHES. HIGHER AMOUNTS POSSIBLE WHICH COULD CAUSE MINOR ISOLATED HYDRO PROBLEMS. THIS RAIN HELPED BY GOOD LIFT AND FORCING AND PWATS OF 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL. DEWPTS 60S AND TROPICAL MOISTURE. WITH RIVERS NEAR NORMAL 1 TO 2 INCHES WOULD MOST LIKELY NOT CAUSE ANY FLOODING. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... 230 PM UPDATE... MED RANGE MODELS INDICATING CDFNT WL BE BISECTING CWA AT BEGINNING OF LONG TERM. HV GONE WITH LKLY/CATEGORICAL POPS EAST OF I-81 WITH CHC FURTHER BACK TO THE WEST. MAINLY SHOWERS EXPECTED FOLLOWING FROPA. REMAINDER OF LONG TERM WL FEATURE SHOWERS EACH PD COURTESY OF UPR LVL LOW HANGING BACK TO THE WEST. AS IS TYPICAL IN THESE CASES, EXPECT THAT AFT 12Z SATURDAY MOST OF THE SHOWERS WL BE OF THE MORE HIT AND MISS VARIETY WITH MOSTLY MISSES. THUS, THRU THE END OF THE LONG TERM WL KEEP 20-30 POPS OVR ENTIRE CWA. TEMPS DRG THE PD EXPECTED TO BE BLO NRML UNDER EXTENSIVE CLD CVR. FOLLOWED WPC GRIDS FOR THE LONG TERM WITH NO SIGNIFICANT DISCREPANCIES BTWN MED RANGE GUIDANCE. && .AVIATION /05Z WEDNESDAY THROUGH SUNDAY/... THE NAM AND RAP MODELS ARE BACKING OFF ON THE EXTENT OF THE PROJECTED MARINE LAYER FOR THE OVERNIGHT HOURS. OUR LATEST FORECAST INCLUDES A TEMPO PERIOD FOR MVFR TO BORDERLINE IFR CEILINGS FROM AVP UP TO ITH. MODEL SOUNDINGS SUGGEST A BURN OFF BETWEEN 13Z AND 15Z, THEN A PARTLY SUNNY AFTERNOON WITH A SCATTERED CU DECK BETWEEN 3500 AND 5000 FEET. THERE IS A SLIGHT CHANCE FOR AN AFTERNOON SHOWER OR THUNDERSTORM. OUTLOOK... WED NGT/THUR...MAINLY VFR, BUT POSSIBLE MVFR PDS IN SHOWERS AND THUNDERSTORMS. THUR NGT/FRI...MVFR AND POSSIBLE IFR RESTRICTIONS IN SHRA/TSRA AS COLD FRONT STALLS NEAR AREA. SAT...MVFR RESTRICTIONS POSSIBLE EARLY, BECOMING VFR DURING THE AFTERNOON. SUN...MVFR RESTRICTIONS POSSIBLE IN ISOLATED SHOWERS BUT MAINLY VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...TAC NEAR TERM...MSE/RRM/TAC SHORT TERM...TAC LONG TERM...PVN AVIATION...DJP
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
144 AM EDT WED MAY 14 2014 .SYNOPSIS... HIGH PRESSURE OFFSHORE WILL MAINTAIN ABOVE NORMAL TEMPERATURES FOR ONE MORE DAY. A COLD FRONT WILL APPROACH ON THURSDAY AND MOVE ACROSS THE AREA LATE THURSDAY NIGHT AND EARLY FRIDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED THURSDAY AND THURSDAY NIGHT...PERHAPS LINGERING INTO FRIDAY FOR PORTIONS OF THE AREA. MUCH COOLER AND DRIER CONDITIONS ARE EXPECTED FOR THE WEEKEND AND EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 1045 PM TUESDAY...THE WELL AMPLIFIED UPPER RIDGING WILL SLOWLY PROGRESS EASTWARD TONIGHT...WITH MODELS INDICATING THE NORTH TO SOUTH UPPER RIDGE AXIS NEARLY OVERHEAD BY WEDNESDAY DAYBREAK. SUBSIDENCE UNDERNEATH THIS UPPER RIDGING HAS KEPT THE DIURNALLY INDUCED/DRIVEN CONVECTION TO A MINIMUM...INCLUDING ALONG THE INLAND PROGRESSIVE SEA BREEZE BOUNDARY. LATEST HRRR HOURLY REFLECTIVITY MODEL RUN HAS FINALLY CAUGHT UP WITH REALITY AND NOW INDICATES NO PCPN ACROSS THE FA FOR THE REMAINDER OF THE NIGHT. SKIES OVERALL WILL REMAIN CLEAR OVERNIGHT. NAMBUFR SOUNDINGS INDICATE A WEAK SFC BASED INVERSION TO OCCUR OVERNIGHT BUT NOT ALL THAT IMPRESSIVE FOR A WIDESPREAD FOG OR LOW STRATUS OCCURRENCE. FAMOUS LAST WORDS. AS A RESULT...HAVE KEPT FOG AND LOW STRATUS TO A MINIMUM DURING THE OVERNIGHT PERIOD. SFC WINDS PROGGED TO REMAIN JUST ACTIVE ENOUGH...5 MPH OR LESS. USING THE PREVIOUS NIGHT MIN TEMPS AS GUIDANCE AND PERSISTENCE...STAYED JUST ABOVE LAST NIGHTS MINS. PREVIOUS DISCUSSION.................................... AS OF 300 PM TUESDAY...ELONGATED AREA OF HIGH PRESSURE CENTERED SEVERAL HUNDRED MILES OFF THE SOUTH CAROLINA COAST IS EXTENDING BACK TOWARDS THE SOUTHEAST...WITH A RIDGE AXIS ALIGNED E-W JUST SOUTH OF CHARLESTON, SC. THIS IS PUMPING WARM SW RETURN FLOW ACROSS THE ILM CWA. AT THE SAME TIME...HIGHLY AMPLIFIED 500MB RIDGE IS DRIFTING EAST...REMAINING NEARLY OVERHEAD THROUGH TONIGHT. THESE TWO FEATURES TOGETHER ARE CREATING A TYPICAL SUMMERTIME PATTERN...WITH TEMPS ONCE AGAIN RISING TO AROUND 90 LOCALLY...4-8 DEGREES ABOVE NORMAL. THE COMBINATION OF HOT TEMPS AND DEWPOINT VALUES IN THE MID/UPR 60S HAS ONCE AGAIN ALLOWED WIDESPREAD DIURNAL CU TO DEVELOP ACROSS THE AREA...WITH THE MOST CONGESTED FIELDS FOCUSED ALONG THE SEA BREEZE. HAVE CONTINUED WITH A SMALL AREA OF 20 POP FOR ISOLATED SHOWERS ALONG THE SEA BREEZE FOR THE NEXT FEW HOURS...AND A FEW REFLECTIVITY ECHOES HAVE APPEARED THIS AFTN...BUT THE CHANCE FOR ANY MEANINGFUL SHOWERS ANYWHERE IS DECREASING RAPIDLY. AS EXPECTED...COVERAGE HAS BEEN MUCH LESS THAN YESTERDAY THANKS TO MORE SUBSIDENCE ALOFT AND DRIER MID-LEVEL AIR. ANY CONVECTION WILL WANE TOWARDS...AND ESPECIALLY AFTER...SUNSET...AS WILL ANY DIURNALLY FORCED CLOUD COVER. ALTHOUGH SKY CONDITIONS WILL CLEAR TONIGHT...LIGHT SW WINDS WILL MAINTAIN SOME MIXING...AND THUS LOWS WILL FALL ONLY TO AROUND 70 AT THE COAST...COOLING TO THE MID 60S WELL INLAND...AS ANOTHER ABOVE NORMAL NIGHT OCCURS LOCALLY. THE AIR MASS IS PRIMARILY UNCHANGED FROM LAST NIGHT...SO PATCHY FOG WILL ONCE AGAIN DEVELOP...BUT WIDESPREAD OR DENSE FOG IS NOT ANTICIPATED. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 300 PM TUESDAY...WEDNESDAY WILL BE ONE LAST WARM AND RAIN FREE DAY BEFORE SOME SUBSTANTIAL CHANGES GET UNDERWAY. EASTWARD MOVING UPPER RIDGE STILL OVER THE AREA ENOUGH ON WEDNESDAY TO KEEP A CAP ON CONVECTION ALONG THE COAST. AT THE SURFACE WEST ATLANTIC HIGH PRESSURE WILL WEAKEN FOR A LIGHT AND VARIABLE FLOW THAT WILL ALLOW GOOD INLAND PROGRESS OF A SEA BREEZE THAT WILL TAPER THE HEAT ANYWHERE EAST OF ITS PROGRESS. A SHARPENING AND PHASING TROUGH OVER THE NATIONS MIDSECTION ALONG WITH ITS ATTENDANT COLD FRONT WILL MAKE FOR SOME DEEP MOISTURE ADVECTION FROM WEST TO EAST...KICKING IN OVER WESTERN ZONES LATER WEDNESDAY NIGHT. THE RAPID WEST TO EAST INC IN CLOUDS WILL THEN BE FOLLOWED BY RAIN CHANCES THAT INCREASE IN THE SAME FASHION ON THURSDAY AS HEIGHT FALLS OVERSPREAD THE AREA. THE MOST UNSETTLED WEATHER COMES THURSDAY EVENING AND NIGHT HOWEVER AS ENERGY BELLYING UNDER THE SLIGHTLY NEGATIVELY TILTED UPPER WAVE BRINGS A SURFACE LOW UP THE COAST. MODERATE TO HEAVY RAINFALL SEEMS A NEAR CERTAINTY...THE SEVERE WEATHER THREAT IS A BIT HIGHER TO DIAGNOSE. LOW LEVEL WIND FIELDS WILL BE STRONG INCLUDING IN THE LOWER LEVELS. DEEP LAYER INSTABILITY IS LACKING FOR THE MOST PART THURSDAY NIGHT...BUT EVEN ABSENT DEEP CONVECTION THERE MAY BE STRONG ENOUGH FORCING FOR THE STRAY TORNADO SPIN UP GIVEN VERY STRONG SRH IN BOTH THE 0-3KM AND 0-1KM LAYERS. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 300 PM TUESDAY...A NORTH-SOUTH ORIENTED COLD FRONT WILL BE DRAPED ACROSS EASTERN NC EARLY FRIDAY...WITH THE BOUNDARY EXPECTED TO PUSH OFF THE SOUTHEAST NC COAST DURING THE MORNING HOURS. ONGOING WIDESPREAD CONVECTIVE ACTIVITY EARLY FRIDAY WILL BE ENHANCED IN THE VICINITY OF A SURFACE WAVE OF LOW PRESSURE LIFTING ACROSS THE CWA. CONVECTION WILL SHIFT NORTHEAST OF THE AREA WITH POPS TRENDING DOWN FROM SOUTHWEST TO NORTHEAST DURING THE 12-18 UTC WINDOW. THE SYNOPTIC PATTERN WILL BE SLOW TO PROGRESS DURING THE FRI-TUE TIME FRAME...SO THE WEAK SURFACE HIGH PRESSURE THAT BUILDS ACROSS THE CAROLINAS IN THE WAKE OF THE COLD FRONT WILL PERSIST THROUGH THE PERIOD. TEMPS WILL REMAIN A FEW DEGREES SHY OF CLIMO EACH DAY. MODELS SUGGEST SOME MOISTURE ROTATING AROUND THE BASE OF THE MID-UPPER TROUGH SUNDAY WHICH WOULD RESULT IN SOME ENHANCED CLOUDINESS. IMPULSES CIRCULATING THROUGH THE MID-LEVEL FLOW MAY AFFECT THE AREA SUN-TUE AND THEREFORE CAN`T RULE OUT PRECIP POTENTIAL ALTOGETHER...BUT CHANCES WILL REMAIN LOW. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 06Z...SINCE THE AIRMASS REMAINS RELATIVELY UNCHANGED FROM EARLY TUE MORNING...THERE SHOULD BE THE SAME POTENTIAL FOR IFR FOG/ST EARLY THIS MORNING. CONFIDENCE IS SLIGHTLY HIGHER THAT TERMINALS WILL BE AFFECTED BASED ON SLIGHTLY MORE LOW LEVEL MOISTURE. TIME OF OCCURRENCE SHOULD BE GENERALLY 08-12Z WHEN AIRMASS IS COOLEST AND WINDS LIGHTEST. MVFR CIGS WILL BE POSSIBLE 12-15Z WITH VFR EXPECTED THEREAFTER. WINDS WILL BE SE-S DURING THE DAY...STRONGEST AT THE COASTAL TERMINALS DURING THE AFTERNOON. AFTER 00Z WINDS WILL DECREASE...BUT FAIRLY STRONG BOUNDARY LAYER WINDS WILL CONTINUE. THIS SHOULD PUMP LOW LEVEL ATLANTIC MOISTURE IN OFF THE ATLANTIC. MVFR CIGS COULD OCCUR DURING THE EVENING BUT CONFIDENCE IS LOW ATTM. EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR SHRA/ISOLATED TSRA WITH MVFR/IFR THU AFTN THROUGH FRI MORNING. VFR SAT AND SUN. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1045 PM TUESDAY...RIDGING ACROSS THE WATERS FROM THE SFC HIGH CENTERED OFFSHORE AND EAST OF THE CAROLINAS...WILL PERSIST OVERNIGHT INTO WEDNESDAY. THE POSITIONING OF THE SFC RIDGE AXIS WILL DETERMINE WIND DIRECTIONS. NORTH OF THE RIDGE AXIS...LOOK FOR SSW-SW DIRECTIONS...SOUTH OF THE AXIS LOOK FOR SSE-SSW DIRECTIONS. THE SFC PRESSURE GRADIENT REMAINS LOOSE AND THUS WIND SPEEDS IN GENERAL AROUND 10 KT OR LESS. EXCEPTION 10 TO 15 KT NEAR SHORE THROUGH THIS EVENING DUE TO THE DEMISE OF THE SEA BREEZE CIRCULATION. SIGNIFICANT SEAS WILL RUN 2 TO 3 FT. WITH A DECENT FETCH IN PLACE AND EXTENDING OFFSHORE...A SOLID 2 FOOT SE PSEUDO GROUND SWELL EXHIBITING 7 TO 8 SECOND PERIODS WILL AFFECT THE AREA WATERS. COMBINED WITH LOCALLY PRODUCED WIND-WAVES...A SOLID 2 TO 3 FOOT SIGNIFICANT SEAS WILL BE FORECAST. PREVIOUS DISCUSSION.................................... AS OF 300 PM TUESDAY...HIGH PRESSURE ANCHORED OFFSHORE REMAINS IN PLACE...RIDGING BACK TOWARDS THE COAST. THIS IS PRODUCING SW WINDS AROUND 10 KTS OVER THE COASTAL WATERS...EXCEPT WITHIN THE NEAR-SHORE SEA BREEZE WHERE SOUTHERLY WINDS UP TO 15 KTS EXIST. THESE WILL ONCE AGAIN BECOME A UNIFORM SSW WIND AROUND 10 KTS OVERNIGHT. WAVE HEIGHTS WILL BE 2-3 FT THROUGH THE PERIOD...WITH A SE GROUND SWELL AND S/SW WIND WAVE COMPRISING THE SPECTRUM. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 PM TUESDAY...QUITE A BIT OF DICHOTOMY BETWEEN THE PERIODS OF THE SHORT TERM. STARTING OFF WEDNESDAY WITH A VERY LIGHT WIND OUT OF THE SOUTH AS HIGH PRESSURE WILL BE FOUND ACROSS MUCH OF THE WESTERN ATLANTIC BUT WITH A CENTER REMOVED NORTH AND EAST OF WHAT IS MORE TYPICAL DURING THE SPRING. THE WIND WAVES WILL BE LIGHT BUT WNA GUIDANCE SHOWING SOME SOUTHEASTERLY SWELL ENERGY. SOUTHEASTERLY FLOW ON THURSDAY WILL SIMILARLY BE FAIRLY BENIGN THROUGH THE DAY BUT WILL SHOW A STEEP RAMP UP THOUGH THE EVENING AND INTO THE OVERNIGHT HOURS. A VERY STRONG UPPER LEVEL STORM SYSTEM WILL BE GETTING CARVED OUT OVER THE MID SECTION OF THE NATION. A COLD FRONT WILL BE APPROACHING FROM THE WEST WHILE LOW PRESSURE STRENGTHENS ALONG THE BOUNDARY OVER THE WEST COAST OF FLORIDA. AS THIS WAVE MOVES UP ALONG THE SOUTHEAST COAST THE WINDS WILL BECOME QUITE STRONG AND A SMALL CRAFT ADVISORY IS EXPECTED. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 300 PM TUESDAY...DEPENDING ON THE EXACT TIMING OF THE FRONTAL PASSAGE EARLY FRIDAY...SMALL CRAFT ADVISORY CONDITIONS MAY STILL BE ONGOING FRIDAY MORNING...ESPECIALLY FROM CAPE FEAR NORTH. HOWEVER CONDITIONS WILL IMPROVE DURING THE MORNING HOURS AS WEAK HIGH PRESSURE BUILDS IN. WINDS WILL DIMINISH TO 15 KT BY MIDDAY FRIDAY AND SHIFT TO AN OFFSHORE TRAJECTORY. THE PRESSURE GRADIENT WILL CONTINUE TO WEAKEN WITH SPEEDS EXPECTED TO FALL TO 10 KT OR LESS SATURDAY-SUNDAY. BY SUNDAY...SOME VARIABILITY IN THE WIND DIRECTION CAN BE EXPECTED AS SPEEDS LOOK TO DROP BELOW 10 KT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...DCH/JDW SHORT TERM...MBB LONG TERM...CRM AVIATION...MRR/RJD
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1119 PM MDT TUE MAY 13 2014 .SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT ISSUED AT 220 PM MDT TUE MAY 13 2014 LONG WAVE TROF JUST EAST OF THE CWA THIS MORNING WITH UPSTREAM RIDGE JUST OFF THE WEST COAST. LONG WAVES HAVE BEEN VERY SLOW MOVING LAST SEVERAL DAYS AND ARE FORECAST TO REMAIN NEARLY STATIONARY THROUGH THURSDAY. AMPLIFICATION THAT HAD BEEN UNDERWAY HAS CEASED. SO LITTLE CHANGE IN THE LONG WAVE PATTERN IS EXPECTED DURING THE SHORT TERM. WEAK SHORT WAVE TROFS ARE MOVING SOUTHWARD BEHIND THE LONG WAVE TROF OVER OUR CWA. ONE HAS EXITED THE AREA WITH ANOTHER VERY SUBTLE ONE JUST BARELY VISIBLE ON THE WATER VAPOR LOOP APPROACHING THIS AFTERNOON. HRRR MODEL HAS BEEN CONSISTENTLY SHOWING WIDELY SCATTERED SHOWERS DEVELOPING THIS AFTN OVER NE WYOMING AND THE BLACK HILLS...BUT WITH A BIT STRONGER AND MORE WELL ORGANIZED SHOWERS AND A FEW TSTMS FORECAST TO DEVELOP WITH THE SHORT WAVE LATE AFTN INTO THIS EVENING OVER NE WYOMING INTO THE BLACK HILLS. THERE IS SUPPORT FOR THIS DEVELOPMENT IN MODEST 700 MB Q VECTOR CONVERGENCE SHOWN BY THE NAM. TOMORROW NIGHT THERE IS A HINT OF ANOTHER WAVE...BUT LESS CERTAINTY ACCOMPANIES THIS FEATURE. CONVECTION IS ALSO SUGGESTED BY THE GFS FORECASTS OF 500MB TEMPERATURES NEAR 5 STANDARD DEVIATIONS BELOW THE SEASONAL MEAN. WITH STRONG SFC HEATING...THIS IMPLIES CONSIDERABLE INSTABILITY NEXT SEVERAL DAYS. STAYED CLOSE TO GUIDANCE WITH TEMPERATURES AND USED THE NAM FOR SURFACE WINDS...WITH SOME UPWARD ADJUSTMENT IN AFTN SPEEDS. BECAUSE WE HAVE BEEN QUITE COLD LATELY...I DECIDED NOT TO ISSUE FROST/FREEZE ADVISORY. && .LONG TERM...THURSDAY THROUGH TUESDAY ISSUED AT 220 PM MDT TUE MAY 13 2014 NORTHWEST FLOW WILL CONTINUE THROUGH THE END OF THE WEEK WITH FAST MOVING UPPER DISTURBANCES AND A NEARLY STATIONARY FRONTAL BOUNDARY OVER THE HIGH PLAINS. THIS WILL RESULT IN NEAR DAILY CHANCES FOR SHOWERS...ESPECIALLY OVER NORTHEAST WYOMING AND FAR WESTERN SOUTH DAKOTA. SLIGHTLY BELOW AVERAGE TEMPS ARE EXPECTED THROUGH THE END OF THE WEEK. AN UPPER TROUGH/CUT OFF LOW IS PROGGED TO DEVELOP EARLY NEXT WEEK OVER THE NW CONUS. UPPER FLOW WOULD THEN BECOME MORE SWRLY WITH WARM AND MOIST AIR ADVECTING IN FROM THE S/SE. THIS WILL INCREASE CHANCES FOR THUNDERSTORMS FOR THE EARLY PART OF NEXT WEEK ALONG WITH NEAR TO SLIGHTLY ABOVE AVERAGE TEMPERATURES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1118 PM MDT TUE MAY 13 2014 ISOLATED SHOWERS/THUNDERSTORMS POSSIBLE ON WEDNESDAY AFTERNOON WITH LCL MVFR VSBY...OTHERWISE VFR CONDITIONS WILL PREVAIL. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...BARBER LONG TERM...77 AVIATION...7
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1212 AM CDT WED MAY 14 2014 .UPDATE...AVIATION DISCUSSION. && .PREV DISCUSSION... /ISSUED 833 PM CDT TUE MAY 13 2014/ UPDATE... A STRONG COLD FRONT STRETCHED FROM AROUND PARIS TN TO TO NEAR OXFORD MS THIS EVENING. THE FRONT WILL GRADUALLY STALL ACROSS THE AREA TONIGHT WITH BROAD SOUTHWESTERLY FLOW ALOFT. A FEW THUNDERSTORMS LINGER ALONG THE FRONT BUT HAVE WEAKENED IN INTENSITY FROM EARLIER THIS AFTERNOON AS MLCAPES HAVE DECREASED TO BETWEEN 500 AND 1000 J/KG. THE HRRR MODEL CONTINUE TO INDICATE WIDESPREAD RAIN PUSHING INTO MUCH OF THE MIDSOUTH OVERNIGHT FROM THE SOUTHWEST...ESPECIALLY ALONG AND BEHIND THE FRONT...AS A SHORT WAVE EMBEDDED IN THE SOUTHWEST FLOW ALOFT MOVES TOWARD THE REGION. MUCH COOLER AIR WILL ALSO CONTINUE TO MOVE INTO THE AREA BEHIND THE FRONT. HAVE ALREADY UPDATED THE ZONE FORECASTS AND GRIDS TO MAKE A FEW TWEAKS FOR TONIGHT...BUT THE FORECAST REMAINS ON TRACK. LEFT THE FLASH FLOOD WATCH AS IS FOR EASTERN AR AND THE MO BOOTHEEL. THUNDERSTORMS ARE EXPECTED TO INCREASE IN INTENSITY ALONG AND AHEAD OF THE FRONT BY LATE WEDNESDAY MORNING INTO AFTERNOON WITH A FEW STORMS POSSIBLY SEVERE FROM THE SOUTHEASTERN CORNER OF WEST TN NEAR THE TN RIVER INTO NORTHEAST MS. JCL DISCUSSION... /ISSUED 343 PM CDT TUE MAY 13 2014/ A LARGE UPPER LEVEL TROUGH REMAINS STRETCHED FROM THE UPPER MISSISSIPPI VALLEY SOUTHWESTWARD ACROSS THE SOUTHERN PLAINS THIS AFTERNOON. A POTENT SHORTWAVE EMBEDDED WITHIN THE BASE OF THE UPPER TROUGH CONTINUES TO MOVE EAST ACROSS EASTERN NEW MEXICO THIS AFTERNOON. THIS SHORTWAVE WILL BE THE FOCUS FOR EXPECTED WEATHER CONDITIONS TONIGHT AND WEDNESDAY. IN THE SHORT-TERM...A SLOW MOVING COLD FRONT ALIGNED ALONG THE MISSISSIPPI RIVER AS OF 20Z CONTINUES TO PUSH SLOWLY EASTWARD. SCATTERED SHOWERS AND THUNDERSTORMS ARE FORMING LATE THIS AFTERNOON JUST AHEAD OF THE FRONT. THESE STORMS HAVE FORMED IN A MODERATELY UNSTABLE AND LOW SHEAR ENVIRONMENT. MLCAPES IN A CORRIDOR JUST AHEAD OF THE FRONT RANGE FROM 1000-1500 J/KG WITH LOW LEVEL LAPSE RATES APPROACHING 8.0 C/KM. THIS HAS ALLOWED STORMS TO BECOME STRONG THIS AFTERNOON IN THESE AREAS WITH THE POTENTIAL FOR STRONG GUSTY WINDS AND SMALL HAIL. MEAGER MID LEVEL LAPSE RATES AND WEAK SHEAR WILL LIKELY KEEP STORMS OF THE PULSE VARIETY AND MAINLY BELOW SEVERE LIMITS. THESE SHOWERS AND STORMS SHOULD CONTINUE INTO THE EVENING WITH A REDUCTION IN INTENSITY AND COVERAGE LATER THIS EVENING. BY LATER TONIGHT...THE AFOREMENTIONED SHORTWAVE OVER THE SOUTHERN PLAINS WILL CONTINUE TO MOVE EASTWARD WITH FALLING MID LEVEL HEIGHTS...ESPECIALLY ACROSS WESTERN AREAS AFTER MIDNIGHT. SHOWERS AND THUNDERSTORMS SHOULD EXPAND IN COVERAGE LATE TONIGHT ESPECIALLY ON THE COOL SIDE OF THE SLOW MOVING COLD FRONT WHICH SHOULD MOVE AS FAR EAST AS WEST TENNESSEE INTO NORTHWEST MISSISSIPPI BY SUNRISE WEDNESDAY MORNING. THUNDERSTORMS MAY PRODUCE HEAVY RAINFALL ACROSS WESTERN PORTIONS OF THE MID SOUTH. THE POTENTIAL FOR FLOODING REMAINS SOMEWHAT BORDERLINE...BUT CONSIDERING THE FACT THAT FLASH FLOOD GUIDANCE IS LOW AND CONVECTIVE COVERAGE SHOULD EXPAND LATER TONIGHT INTO WEDNESDAY MORNING...WILL LEAVE THE FLASH FLOOD WATCH IN PLACE. THE SHORTWAVE WILL CONTINUE TO DIG OVER THE MID SOUTH ON WEDNESDAY AS IT TAKES ON AN INCREASINGLY NEUTRAL TO EVEN SLIGHTLY POSITIVE TILT. AS MID LEVEL HEIGHT FALLS ASSOCIATED WITH THE SHORTWAVE BEGIN TO OVERTAKE THE SURFACE FRONT AND OVERSPREAD THE WARM SECTOR STILL IN PLACE OVER PORTIONS OF WEST TENNESSEE...NEAR THE TENNESSEE RIVER...AND NORTHEAST MISSISSIPPI....THE ATMOSPHERE SHOULD FURTHER DESTABILIZE BY LATE MORNING INTO EARLY AFTERNOON. THE UPPER LEVEL FORCING AND ASSOCIATED 70 KT CYCLONICALLY CURVED MID LEVEL JET SHOULD HELP TO INDUCE A SURFACE WAVE OF LOW PRESSURE THAT WILL LIFT NORTHEAST ALONG THE FRONT OVER EASTERN PORTIONS OF THE FORECAST AREA THROUGH WEDNESDAY AFTERNOON. DEEP LAYER SHEAR SHOULD STRENGTHEN OVER THE AREA AS THE ATMOSPHERE BECOMES SOMEWHAT UNSTABLE OVER EASTERN SECTIONS OF THE REGION. NUMEROUS THUNDERSTORMS SHOULD DEVELOP AND INTENSIFY ALONG AND AHEAD OF THE FRONT. LOW LEVEL DIRECTIONAL SHEAR IN ADVANCE OF THE SURFACE FLOW SHOULD BECOME BACKED. CONSIDERING ALL OF THESE FACTORS...THERE WILL BE THE POTENTIAL FOR A FEW SEVERE STORMS TO DEVELOP ACROSS PORTIONS OF WEST TENNESSEE...NEAR THE TENNESSEE RIVER...AND NORTHEAST MISSISSIPPI ON WEDNESDAY. THE PRIMARY SEVERE WEATHER THREATS SHOULD BE DAMAGING WINDS AND A FEW TORNADOES. A SLIGHT RISK FOR SEVERE STORMS EXISTS OVER THESE AREAS FOR TOMORROW. TIMING FOR THE SEVERE WEATHER THREAT WILL BE FROM LATE MORNING THROUGH THE AFTERNOON HOURS. TO THE WEST OF THE FRONT...VERY COOL CONDITIONS WILL PREVAIL WITH HIGH TEMPERATURES REMAINING IN UPPER 50S TO LOWER 60S. AHEAD OF THE FRONT...TEMPERATURES SHOULD RISE INTO THE MID AND UPPER 70S. AS THE SHORTWAVE MOVES NORTHEAST OF THE AREA BY EVENING AND THE SURFACE LOW LIFTS QUICKLY NORTHEAST...EXPECT THE COLD FRONT TO SWEEP EAST OF THE AREA WITH SHOWERS AND THUNDERSTORMS ENDING FROM WEST TO EAST THROUGH THE EVENING. DRY AND COOL CONDITIONS WILL RETURN BRIEFLY BY LATER WEDNESDAY NIGHT. ANOTHER SHORTWAVE ROTATING THROUGH THE UPPER TROUGH AND TO THE SOUTH OF A DEVELOPING UPPER LEVEL LOW PRESSURE SYSTEM OVER THE GREAT LAKES REGION WILL MOVE ACROSS THE MID SOUTH THURSDAY AFTERNOON AND EVENING. VERY COLD MID LEVEL TEMPERATURES AND STEEP MID LEVEL LAPSE RATES WILL SUPPORT ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS THURSDAY AFTERNOON AND EVENING. THE GREATEST COVERAGE SHOULD REMAIN ACROSS NORTHEAST ARKANSAS AND THE MISSOURI BOOTHEEL INTO NORTHWEST TENNESSEE WHERE INSTABILITY WILL BE MAXIMIZED. A FEW OF THE STORMS MAY PRODUCE GUSTY WINDS AND SMALL HAIL. TEMPERATURES WILL BE HELD SEVERAL DEGREES BELOW NORMAL WITH HIGHS MAINLY IN THE MID TO UPPER 60S. THE UPPER LEVEL LOW WILL SLOWLY MOVE ACROSS THE GREAT LAKES THROUGH THE WEEKEND. A SERIES OF WEAKER SHORTWAVES SHOULD MOVE ACROSS THE REGION BRINGING PERIODIC CHANCES FOR SHOWERS AND CONTINUED BELOW AVERAGE TEMPERATURES. UPPER LEVEL RIDGING WILL FINALLY REBUILD BACK INTO THE REGION BY EARLY NEXT WEEK WITH A RETURN TO DRY WEATHER AND WARMER TEMPERATURES. JLH && .AVIATION...06Z TAF CYCLE MAINLY IFR CEILINGS WILL BE FOUND FOR MUCH OF THE FORECAST PERIOD. PERIODS OF RAIN SHOWERS WILL OCCUR OVERNIGHT AND CONTINUE THROUGH MUCH OF WEDNESDAY BEFORE FINALLY ENDING FROM WEST TO EAST DURING THE EVENING HOURS. WINDS WILL BE MAINLY FROM THE NORTH AT 5 TO 10 KNOTS FOR MUCH OF THE FORECAST PERIOD. ARS && .MEG WATCHES/WARNINGS/ADVISORIES... AR...FLASH FLOOD WATCH THROUGH THIS EVENING FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...FLASH FLOOD WATCH THROUGH THIS EVENING FOR DUNKLIN-PEMISCOT. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1203 AM CDT WED MAY 14 2014 .AVIATION... WILL BE KEEPING WITH -RA AS PREVAILING WX FOR MOST SITES THE REST OF THE NIGHT AS THE NEXT SHORTWAVE ARRIVES FROM THE WEST AND INT- ERACTS WITH THE MOISTURE/LIFT STILL MOVING IN FROM THE EAST. MVFR CIGS/VIS LIKELY GIVEN THE ONGOING TRENDS. OTHERWISE STILL LOOKING FOR CLEARING/SKC LATE THIS MORNING/EARLY AFTN HRS. 41 && .PREV DISCUSSION... /ISSUED 931 PM CDT TUE MAY 13 2014/ AREA OF SHRA & ISO TSRA ASSOCIATED W/ UPPER TROF WILL BE PUSHING THRU OVERNIGHT. PRECIP IS A BIT FURTHER SOUTH THAN EARLIER GUIDANCE SUGGESTED IT WOULD BE SO EXPANDED HIGHER POPS CLOSER TO THE COAST. HRRR SEEMS TO HAVE A DECENT HANDLE ON THINGS ATTM AND GEARED SHORT TERM FCST TOWARD ITS SOLN. NOT EXPECTING THE MAGNITUDE OF ACCUMULATIONS WE SAW LAST NIGHT...BUT ANY ADDITIONAL RAIN REMAINS WELCOME FOR MOST PARTS. TEMPS LOOK GOOD SO NO UPDATES THERE. DID MOVE UP BEGIN TIME FOR THE SMALL CRAFT ADVY AS WINDS ARE PICKING UP AND ARE NEAR OR ABOVE CRITERIA FOR MOST WATERS. 47 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 55 70 48 77 53 / 70 20 10 0 0 HOUSTON (IAH) 59 70 50 79 55 / 70 20 10 0 0 GALVESTON (GLS) 63 72 57 76 64 / 60 30 10 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 4 PM CDT WEDNESDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...99 AVIATION/MARINE...41
AREA FORECAST DISCUSSION
NWS ALBANY NY
722 AM EDT WED MAY 14 2014 .SYNOPSIS... A BACKDOOR COLD FRONT IS SITUATED SOUTH AND WEST OF THE REGION AND WILL REMAIN NEARLY STATIONARY THROUGHOUT THE DAY TODAY. THIS FRONT WILL BE THE FOCUS FOR SOME SHOWERS AND THUNDERSTORMS FOR THE WESTERN PORTION OF THE REGION. BY TONIGHT INTO TOMORROW...THIS FRONT WILL START TO DISSIPATE...AS A WARMER AND MORE HUMID AIR MASS MOVES INTO THE AREA. A SLOW MOVING COLD FRONT FROM THE WEST WILL BRING A WIDESPREAD SOAKING RAIN TO THE ENTIRE REGION FOR LATE THURSDAY NIGHT THROUGH SATURDAY MORNING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 631 AM EDT...A BACK DOOR COLD FRONTAL BOUNDARY IS DRAPED ACROSS CENTRAL NY SOUTHWARD THROUGH CENTRAL PA AND TOWARDS THE MID ATLANTIC REGION. THERE IS A NOTICEABLE CHANGE BETWEEN MILDER AND MORE HUMID AIR OVER WESTERN/CENTRAL NY AS COMPARED TO THE DRIER AIR MASS OVER MUCH OF OUR AREA...AS STABLE MARINE AIR HAS BEEN IN PLACE OVER OUR REGION. THIS BOUNDARY ALLOWED FOR REPEATED ROUNDS OF CONVECTION TO DEVELOP DURING TUESDAY EVENING INTO TUESDAY NIGHT...AND THESE COMPLEXES OF SHOWERS/THUNDERSTORMS GRADUALLY WORKED EASTWARD INTO THE MORE STABLE AIR. ALTHOUGH WEAKENING...AN AREA OF SHOWERS AND THUNDERSTORMS IS CURRENTLY STILL ONGOING OVER THE SCHOHARIE VALLEY...EASTERN CATSKILLS...CAPITAL REGION...SARATOGA AREA INTO SRN VT AND THE BERKSHIRES. THE 08Z 3KM HRRR GUIDANCE SUGGESTS THIS ACTIVITY WILL CONTINUE TO WEAKEN AS IT LIFTS NORTHEAST...AND MOST OF THE REGION WILL BECOME DRY BETWEEN 7 AND 10 AM. BEFORE THEN...SOME CONTINUED LIGHT RAIN WITH EMBEDDED THUNDER WILL BE POSSIBLE OVER MUCH OF THE REGION...EXCEPT FOR THE FAR NW ADIRONDACKS THE FAR SE CORNER OF LITCHFIELD COUNTY. THE MOST CONCENTRATED AREA OF RAIN IS CURRENTLY OVER THE WESTERN PARTS OF THE CAPITAL REGION AND HELDERBERGS...WHERE A QUICK QUARTER OF AN INCH OF RAIN COULD FALL OVER THE NEXT HOUR OR TWO. ALTHOUGH THERE WILL BE CLOUDS TO START THE DAY...THERE SHOULD BE SOME BREAKS BY THE MID TO LATE MORNING. THE BOUNDARY WILL REMAIN SITUATED WEST OF OUR REGION...AND WE WILL CONTINUE TO HAVE ONE MORE DAY WITH LOW DEWPOINTS /MAINLY IN THE 40S/. SOME RENEWED SHOWER/THUNDERSTORM ACTIVITY MAY GET GOING DURING DAYTIME HEATING ACROSS CENTRAL NY...AND IT/S POSSIBLE OUR FAR WESTERN AREAS MAY GET BRUSHED ONCE AGAIN FROM THIS DEVELOPMENT. OTHERWISE...A DRY DAY IS EXPECTED FOR MUCH OF THE AREA. ALTHOUGH IT/S VERY WARM ALOFT /850 HPA TEMPS AROUND 15 DEGREES C/...MODEL SOUNDINGS SUGGEST WE WILL ONLY MIX TO ABOUT 925-950 HPA. STILL...THIS WILL EQUATE TO HIGHS REACHING THE MID TO UPPER 70S FOR VALLEY AREAS /UPPER 60S TO LOW 70S FOR THE HIGH TERRAIN/...WHICH IS STILL ABOVE NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... ANY SHOWERS/THUNDERSTORMS OVER FAR WESTERN AREAS SHOULD START TO DISSIPATE IN THE EVENING DUE TO THE LOSS OF DAYTIME HEATING. OTHERWISE... WITH THE LOW LEVEL FLOW EXPECTED TO CONTINUE TO BE OUT OF THE SOUTH...THE BACKDOOR FRONT WILL START TO BECOME DIFFUSE AND EVENTUALLY DISSIPATE TONIGHT. THIS WILL ALLOW MORE HUMID AIR TO MOVE INTO OUR REGION. ALONG WITH THE PERSISTENTLY HUMID SOUTHERLY FLOW WILL BE MORE CLOUDS...AS SOME STRATUS MAY MAKE ITS WAY INTO THE REGION OFF THE CHILLY ATLANTIC. IT/S POSSIBLE THAT SOME LIGHT RAIN SHOWERS OR DRIZZLE MAY ALSO OCCUR ACROSS SOUTHERN AREAS DUE TO MOIST FLOW...ESP IN UPSLOPE FAVORED LOCATIONS. OVERNIGHT LOWS TONIGHT WILL BE IN THE 50S TO NEAR 60. OUR REGION WILL BE IN A WARM SECTOR ON THURSDAY...AS A SLOW MOVING FRONTAL SYSTEM WILL BE OVER THE OHIO VALLEY...AND A STRONG RIDGE WILL BE JUST DOWNSTREAM OF OUR AREA OVER THE WESTERN ATLANTIC. IT SHOULD BE MAINLY DRY ON THURSDAY...ALTHOUGH DIFFERENTIAL HEATING BOUNDARIES...MAINLY ALONG THE HIGH TERRAIN...MAY ALLOW AN AFTN OR EVENING SHOWER OR THUNDERSTORM TO DEVELOP. THE CONTINUED SOUTHERLY FLOW MAY STILL KEEP A LOT OF CLOUDS AROUND...BUT IT STILL LOOKS TO BE ANOTHER WARM DAY...WITH MAX TEMPS WELL INTO THE 70S TO NEAR 80. BY THURSDAY NIGHT...THE FRONTAL SYSTEM TO OUR WEST WILL START TO APPROACH. IT WILL BE MOVING RATHER SLOWLY...AS WEAK WAVES OF LOW PRESSURE DEVELOP AND RIDE UP AND ALONG THE BOUNDARY. AS A RESULT...THE BEST RAIN LOOKS TO STAY TO OUR WEST THURSDAY NIGHT...BUT THERE WILL BE AN INCREASING THREAT FOR SHOWERS AND ISOLATED THUNDERSTORMS. THE STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL CONTINUE TO ADVECT PLENTY OF MOIST AIR INTO THE REGION RIGHT OUT OF THE SUBTROPICS...WITH PWATS EXPECTED TO REACH NEAR 1.50 INCHES. IT WILL BE MUGGY AHEAD OF THE BOUNDARY WITH MIN TEMPS IN THE UPPER 50S TO LOW 60S FOR MANY AREAS. THE BEST RAINFALL LOOKS TO FINALLY REACH OUR AREA FOR FRIDAY INTO FRIDAY NIGHT. RAINFALL MAY BRIEFLY FALL HEAVILY AT TIMES...WITH OVER AN INCH POSSIBLE IN A 6 HR PERIOD FOR SOME LOCATIONS. THIS WILL ESPECIALLY BE TRUE WITHIN ANY EMBEDDED CONVECTION THAT MAY OCCUR WITHIN THE SHIELD OF RAIN SHOWERS...AS SOME ELEVATED INSTABILITY WILL BE PRESENT. WITH THE RAIN/CLOUDS EXPECTED...MAX TEMPS WILL BE COOLER THAN RECENT DAYS...WITH ONLY MID 60S TO LOW 70S ACROSS THE REGION. THE HEAVIEST RAIN WILL BE ENDING FROM WEST TO EAST ON FRIDAY NIGHT...BUT IT WILL CERTAINLY BE TAKING ITS TIME AS IT MOVES ACROSS THE AREA. IT MAY TAKE UNTIL SUNRISE SATURDAY FOR MOST OF THE RAIN TO WIND DOWN ACROSS OUR AREA AS THE FRONT CROSSES FROM WEST TO EAST. TOTAL QPF LOOKS TO GENERALLY BE ONE TO TWO INCHES...ALTHOUGH SOME HIGHER AMOUNTS WILL BE POSSIBLE ACROSS THE HIGH TERRAIN...SOUTHERN AREAS...AND ANY PLACE THAT SEES EMBEDDED CONVECTIVE ELEMENTS. OVERNIGHT LOWS WILL STILL BE IN THE 50S...BUT COOLER AND LESS HUMID AIR WILL MAKING ITS WAY ON IN. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AN UPPER LOW OVER THE WESTERN GREAT LAKES WILL BE SLOWLY APPROACHING THE NORTHEASTERN U.S. SATURDAY AND SUNDAY. THE COLD FRONT AND LOW LEVEL FORCING SHOULD BE EXITING EASTERN NY AND WESTERN NEW ENGLAND SATURDAY MORNING...LEAVING LINGERING SCATTERED SHOWERS OVER OUR AREA INTO SATURDAY NIGHT. CLOUDS IN THE MORNING AND SOME BREAKS OF SUN IN THE AFTERNOON SHOULD SUPPORT HIGHS IN THE 60S TO AROUND 70...SOME UPPER 50S IN HIGHER TERRAIN. WEAK FORCING BUT APPROACHING UPPER DYNAMICS ASSOCIATED WITH THE APPROACHING AND DEVELOPING UPPER LOW IS EXPECTED TO SUPPORT PERIODS OF CLOUDS AND SUN AND ISOLATED TO SCATTERED SHOWERS SUNDAY BUT MOST AREAS SHOULD NOT SEE RAIN. BEST COVERAGE OF SHOWERS MAY BE THE SOUTHERN GREEN MOUNTAINS AND THE BERKSHIRES BUT EVEN THERE SHOULD BE WIDELY SCATTERED. HIGHS SUNDAY IN THE 60S TO AROUND 70 WITH UPPER 50S ONCE AGAIN IN HIGHER TERRAIN. THE UPPER LOW AND UPPER COLD POOL ARE OVER OUR REGION MONDAY AND TUESDAY WITH THE CLASSIC DIURNAL INSTABILITY DAYTIME CLOUDS... SHOWERS AND ISOLATED THUNDERSTORMS...AND PARTIAL CLEARING DURING THE NIGHT. HIGHS MONDAY AND TUESDAY IN THE MID TO UPPER 60S...WITH UPPER 50S IN HIGHER TERRAIN. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... FRONTAL BOUNDARY OVER THE REGION PROVIDING SOME FOCUS FOR SHOWERS IN OUR AREA THAT ARE TRACKING EAST BUT WEAKENING AT THE SAME TIME. SO JUST KEEPING VCSH THROUGH ABOUT 13Z-14Z. OUTSIDE OF THE SCATTERED ACTIVITY EARLY THIS MORNING...CONDITIONS SHOULD BE VFR...WITH CEILINGS ABOVE 3000 FEET. VFR CONDITIONS SHOULD CONTINUE THROUGH THE DAY TODAY...BUT SCATTERED SHOWERS COULD DEVELOP LATE IN THE AFTERNOON AND EVENING SO INDICATING VCSH AFTER 0000Z AT KALB AND KGFL. THERE COULD ALSO BE SOME LOWER CLOUDS BELOW 3000 FEET THAT BEGIN TO DEVELOP THIS EVENING AS THE FRONTAL BOUNDARY DRIFTS EAST AND A MORE HUMID AIRMASS SLOWLY BUILDS EAST ACROSS THE REGION. WINDS TONIGHT WILL GENERALLY BE LESS THAN 5 KNOTS BEFORE BECOMING SOUTHERLY WEDNESDAY AROUND 5-10 KNOTS...BECOMING LIGHT AGAIN TONIGHT. OUTLOOK... THURSDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA. FRIDAY: HIGH OPERATIONAL IMPACT. DEFINITE SHRA...TSRA. FRIDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE SHRA...TSRA. SATURDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA. SATURDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA. SUNDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA. SUNDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA. MONDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA. && .FIRE WEATHER... RAIN SHOWERS HAVE OCCURRED OVERNIGHT ACROSS MANY AREAS. THERE WILL BE A THREAT FOR RAIN SHOWERS AND THUNDERSTORMS OVER THE NEXT FEW DAYS...ESPECIALLY FOR THURSDAY NIGHT THROUGH FRIDAY NIGHT...WHEN A WIDESPREAD HEAVY RAINFALL IS EXPECTED. RH VALUES WILL FALL TO 40 TO 50 PERCENT THIS AFTERNOON ALONG WITH SOUTH WINDS AROUND 10 MPH. RH VALUES WILL RETURN TO NEAR 90 PERCENT TONIGHT WITH CONTINUED SOUTH WINDS AROUND 10 MPH. RH VALUES WILL FALL BACK TO 45 TO 55 PERCENT ON TOMORROW AFTN WITH STRONGER SOUTHERLY WINDS OF 10 TO 20 MPH. && .HYDROLOGY... RAINFALL OVERNIGHT FROM SHOWERS AND THUNDERSTORMS LEAD TO SOME VERY MINOR RISES /LESS THAN A HALF A FOOT/ ACROSS THE WESTERN MOHAWK VALLEY. DURING THE DAY TODAY...SOME ADDITIONAL SHOWERS OR THUNDERSTORMS WILL BE POSSIBLE OVER FAR WESTERN AREAS...BUT THIS WILL HAVE LIMITED IMPACT ON OUR HSA. ASIDE FROM AN ISOLATED SHOWER...MAINLY DRY CONDITIONS ARE EXPECTED FOR TONIGHT INTO TOMORROW. HOWEVER...AN APPROACHING FRONTAL BOUNDARY WILL RETURN WIDESPREAD RAIN TO THE REGION FOR LATE TOMORROW NIGHT THROUGH FRIDAY AND INTO FRIDAY NIGHT. MODERATE TO HEAVY RAINFALL IS POSSIBLE...WITH MOST AREAS EXPECTED TO RECEIVE ONE TO TWO INCHES OF RAINFALL. SOME SPOTS CAN LOCALLY SEE HIGHER AMOUNTS AS WELL. THIS RAINFALL WILL LEAD TO WITHIN BANK RISES ON RIVERS/STREAMS. AT THIS POINT...NO FLOODING IS EXPECTED...ALTHOUGH IF RAINFALL IS GREATER THAN EXPECTED...THEN MINOR RIVER FLOODING COULD BE POSSIBLE AT A FEW LOCATIONS. ALSO...SINCE THE RAINFALL IS EXPECTED TO FALL HEAVY IN A SHORT PERIOD OF TIME...MINOR NUISANCE FLOODING OF POOR DRAINAGE OR LOW LYING AREAS COULD BE POSSIBLE...SUCH AS IN URBAN AREAS. PONDING OF WATER IS EXPECTED ON ROADWAYS...MAKING FOR SLOWER TRAVEL. BEHIND THIS SYSTEM...SOME ISOLATED TO SCATTERED RAIN SHOWERS ARE POSSIBLE OVER THE WEEKEND...BUT COVERAGE SHOULD BE SMALL ENOUGH TO PREVENT ANY ADDITIONAL HYDROLOGIC CONCERNS. THIS SHOULD ALLOW RIVER AND STREAM LEVELS TO RECEDE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...FRUGIS NEAR TERM...FRUGIS SHORT TERM...FRUGIS LONG TERM...NAS AVIATION...NAS FIRE WEATHER...FRUGIS HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
631 AM EDT WED MAY 14 2014 .SYNOPSIS... A BACKDOOR COLD FRONT IS SITUATED SOUTH AND WEST OF THE REGION AND WILL REMAIN NEARLY STATIONARY THROUGHOUT THE DAY TODAY. THIS FRONT WILL BE THE FOCUS FOR SOME SHOWERS AND THUNDERSTORMS FOR THE WESTERN PORTION OF THE REGION. BY TONIGHT INTO TOMORROW...THIS FRONT WILL START TO DISSIPATE...AS A WARMER AND MORE HUMID AIR MASS MOVES INTO THE AREA. A SLOW MOVING COLD FRONT FROM THE WEST WILL BRING A WIDESPREAD SOAKING RAIN TO THE ENTIRE REGION FOR LATE THURSDAY NIGHT THROUGH SATURDAY MORNING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 631 AM EDT...A BACK DOOR COLD FRONTAL BOUNDARY IS DRAPED ACROSS CENTRAL NY SOUTHWARD THROUGH CENTRAL PA AND TOWARDS THE MID ATLANTIC REGION. THERE IS A NOTICEABLE CHANGE BETWEEN MILDER AND MORE HUMID AIR OVER WESTERN/CENTRAL NY AS COMPARED TO THE DRIER AIR MASS OVER MUCH OF OUR AREA...AS STABLE MARINE AIR HAS BEEN IN PLACE OVER OUR REGION. THIS BOUNDARY ALLOWED FOR REPEATED ROUNDS OF CONVECTION TO DEVELOP DURING TUESDAY EVENING INTO TUESDAY NIGHT...AND THESE COMPLEXES OF SHOWERS/THUNDERSTORMS GRADUALLY WORKED EASTWARD INTO THE MORE STABLE AIR. ALTHOUGH WEAKENING...AN AREA OF SHOWERS AND THUNDERSTORMS IS CURRENTLY STILL ONGOING OVER THE SCHOHARIE VALLEY...EASTERN CATSKILLS...CAPITAL REGION...SARATOGA AREA INTO SRN VT AND THE BERKSHIRES. THE 08Z 3KM HRRR GUIDANCE SUGGESTS THIS ACTIVITY WILL CONTINUE TO WEAKEN AS IT LIFTS NORTHEAST...AND MOST OF THE REGION WILL BECOME DRY BETWEEN 7 AND 10 AM. BEFORE THEN...SOME CONTINUED LIGHT RAIN WITH EMBEDDED THUNDER WILL BE POSSIBLE OVER MUCH OF THE REGION...EXCEPT FOR THE FAR NW ADIRONDACKS THE FAR SE CORNER OF LITCHFIELD COUNTY. THE MOST CONCENTRATED AREA OF RAIN IS CURRENTLY OVER THE WESTERN PARTS OF THE CAPITAL REGION AND HELDERBERGS...WHERE A QUICK QUARTER OF AN INCH OF RAIN COULD FALL OVER THE NEXT HOUR OR TWO. ALTHOUGH THERE WILL BE CLOUDS TO START THE DAY...THERE SHOULD BE SOME BREAKS BY THE MID TO LATE MORNING. THE BOUNDARY WILL REMAIN SITUATED WEST OF OUR REGION...AND WE WILL CONTINUE TO HAVE ONE MORE DAY WITH LOW DEWPOINTS /MAINLY IN THE 40S/. SOME RENEWED SHOWER/THUNDERSTORM ACTIVITY MAY GET GOING DURING DAYTIME HEATING ACROSS CENTRAL NY...AND IT/S POSSIBLE OUR FAR WESTERN AREAS MAY GET BRUSHED ONCE AGAIN FROM THIS DEVELOPMENT. OTHERWISE...A DRY DAY IS EXPECTED FOR MUCH OF THE AREA. ALTHOUGH IT/S VERY WARM ALOFT /850 HPA TEMPS AROUND 15 DEGREES C/...MODEL SOUNDINGS SUGGEST WE WILL ONLY MIX TO ABOUT 925-950 HPA. STILL...THIS WILL EQUATE TO HIGHS REACHING THE MID TO UPPER 70S FOR VALLEY AREAS /UPPER 60S TO LOW 70S FOR THE HIGH TERRAIN/...WHICH IS STILL ABOVE NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... ANY SHOWERS/THUNDERSTORMS OVER FAR WESTERN AREAS SHOULD START TO DISSIPATE IN THE EVENING DUE TO THE LOSS OF DAYTIME HEATING. OTHERWISE... WITH THE LOW LEVEL FLOW EXPECTED TO CONTINUE TO BE OUT OF THE SOUTH...THE BACKDOOR FRONT WILL START TO BECOME DIFFUSE AND EVENTUALLY DISSIPATE TONIGHT. THIS WILL ALLOW MORE HUMID AIR TO MOVE INTO OUR REGION. ALONG WITH THE PERSISTENTLY HUMID SOUTHERLY FLOW WILL BE MORE CLOUDS...AS SOME STRATUS MAY MAKE ITS WAY INTO THE REGION OFF THE CHILLY ATLANTIC. IT/S POSSIBLE THAT SOME LIGHT RAIN SHOWERS OR DRIZZLE MAY ALSO OCCUR ACROSS SOUTHERN AREAS DUE TO MOIST FLOW...ESP IN UPSLOPE FAVORED LOCATIONS. OVERNIGHT LOWS TONIGHT WILL BE IN THE 50S TO NEAR 60. OUR REGION WILL BE IN A WARM SECTOR ON THURSDAY...AS A SLOW MOVING FRONTAL SYSTEM WILL BE OVER THE OHIO VALLEY...AND A STRONG RIDGE WILL BE JUST DOWNSTREAM OF OUR AREA OVER THE WESTERN ATLANTIC. IT SHOULD BE MAINLY DRY ON THURSDAY...ALTHOUGH DIFFERENTIAL HEATING BOUNDARIES...MAINLY ALONG THE HIGH TERRAIN...MAY ALLOW AN AFTN OR EVENING SHOWER OR THUNDERSTORM TO DEVELOP. THE CONTINUED SOUTHERLY FLOW MAY STILL KEEP A LOT OF CLOUDS AROUND...BUT IT STILL LOOKS TO BE ANOTHER WARM DAY...WITH MAX TEMPS WELL INTO THE 70S TO NEAR 80. BY THURSDAY NIGHT...THE FRONTAL SYSTEM TO OUR WEST WILL START TO APPROACH. IT WILL BE MOVING RATHER SLOWLY...AS WEAK WAVES OF LOW PRESSURE DEVELOP AND RIDE UP AND ALONG THE BOUNDARY. AS A RESULT...THE BEST RAIN LOOKS TO STAY TO OUR WEST THURSDAY NIGHT...BUT THERE WILL BE AN INCREASING THREAT FOR SHOWERS AND ISOLATED THUNDERSTORMS. THE STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL CONTINUE TO ADVECT PLENTY OF MOIST AIR INTO THE REGION RIGHT OUT OF THE SUBTROPICS...WITH PWATS EXPECTED TO REACH NEAR 1.50 INCHES. IT WILL BE MUGGY AHEAD OF THE BOUNDARY WITH MIN TEMPS IN THE UPPER 50S TO LOW 60S FOR MANY AREAS. THE BEST RAINFALL LOOKS TO FINALLY REACH OUR AREA FOR FRIDAY INTO FRIDAY NIGHT. RAINFALL MAY BRIEFLY FALL HEAVILY AT TIMES...WITH OVER AN INCH POSSIBLE IN A 6 HR PERIOD FOR SOME LOCATIONS. THIS WILL ESPECIALLY BE TRUE WITHIN ANY EMBEDDED CONVECTION THAT MAY OCCUR WITHIN THE SHIELD OF RAIN SHOWERS...AS SOME ELEVATED INSTABILITY WILL BE PRESENT. WITH THE RAIN/CLOUDS EXPECTED...MAX TEMPS WILL BE COOLER THAN RECENT DAYS...WITH ONLY MID 60S TO LOW 70S ACROSS THE REGION. THE HEAVIEST RAIN WILL BE ENDING FROM WEST TO EAST ON FRIDAY NIGHT...BUT IT WILL CERTAINLY BE TAKING ITS TIME AS IT MOVES ACROSS THE AREA. IT MAY TAKE UNTIL SUNRISE SATURDAY FOR MOST OF THE RAIN TO WIND DOWN ACROSS OUR AREA AS THE FRONT CROSSES FROM WEST TO EAST. TOTAL QPF LOOKS TO GENERALLY BE ONE TO TWO INCHES...ALTHOUGH SOME HIGHER AMOUNTS WILL BE POSSIBLE ACROSS THE HIGH TERRAIN...SOUTHERN AREAS...AND ANY PLACE THAT SEES EMBEDDED CONVECTIVE ELEMENTS. OVERNIGHT LOWS WILL STILL BE IN THE 50S...BUT COOLER AND LESS HUMID AIR WILL MAKING ITS WAY ON IN. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AN UPPER LOW OVER THE WESTERN GREAT LAKES WILL BE SLOWLY APPROACHING THE NORTHEASTERN U.S. SATURDAY AND SUNDAY. THE COLD FRONT AND LOW LEVEL FORCING SHOULD BE EXITING EASTERN NY AND WESTERN NEW ENGLAND SATURDAY MORNING...LEAVING LINGERING SCATTERED SHOWERS OVER OUR AREA INTO SATURDAY NIGHT. CLOUDS IN THE MORNING AND SOME BREAKS OF SUN IN THE AFTERNOON SHOULD SUPPORT HIGHS IN THE 60S TO AROUND 70...SOME UPPER 50S IN HIGHER TERRAIN. WEAK FORCING BUT APPROACHING UPPER DYNAMICS ASSOCIATED WITH THE APPROACHING AND DEVELOPING UPPER LOW IS EXPECTED TO SUPPORT PERIODS OF CLOUDS AND SUN AND ISOLATED TO SCATTERED SHOWERS SUNDAY BUT MOST AREAS SHOULD NOT SEE RAIN. BEST COVERAGE OF SHOWERS MAY BE THE SOUTHERN GREEN MOUNTAINS AND THE BERKSHIRES BUT EVEN THERE SHOULD BE WIDELY SCATTERED. HIGHS SUNDAY IN THE 60S TO AROUND 70 WITH UPPER 50S ONCE AGAIN IN HIGHER TERRAIN. THE UPPER LOW AND UPPER COLD POOL ARE OVER OUR REGION MONDAY AND TUESDAY WITH THE CLASSIC DIURNAL INSTABILITY DAYTIME CLOUDS... SHOWERS AND ISOLATED THUNDERSTORMS...AND PARTIAL CLEARING DURING THE NIGHT. HIGHS MONDAY AND TUESDAY IN THE MID TO UPPER 60S...WITH UPPER 50S IN HIGHER TERRAIN. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... FRONTAL BOUNDARY OVER THE REGION PROVIDING SOME FOCUS FOR SHOWERS AND ISOLATED THUNDERSTORMS IN CENTRAL NY THAT ARE TRACKING EAST BUT WEAKENING AT THE SAME TIME. SOME QUESTION AS TO WHETHER THE SCATTERED SHOWERS AND STORMS MAKE IT TO KALB AND KGFL BETWEEN 07Z AND 13Z- 14Z. IF A SHOWER WERE TO AFFECT KALB AND KGFL...IT WOULD BE CLOSER TO 07Z-09Z...BUT THERE ARE SOME LINGERING SHOWERS BEHIND THE LEADING EDGE...SO JUST KEEPING VCSH THROUGH ABOUT 13Z-14Z. IF A SHOWER OR ISOLATED THUNDERSTORM SURVIVES ITS TRACK INTO THE MORE STABLE ENVIRONMENT AROUND KALB AND KGFL...WILL AMEND TO MVFR...AS ANY IFR WOULD BE BRIEF IF AT ALL. RAIN SHOULD NOT MAKE IT TO KPSF OR KPOU. OUTSIDE OF THE SCATTERED ACTIVITY EARLY THIS MORNING...CONDITIONS SHOULD BE VFR...WITH CEILINGS ABOVE 4000 FEET. CONVECTIVE DEBRIS ABOVE 4000 FEET SHOULD PREVENT ANY FOG OR LOW CLOUDS FROM FORMING. VFR CONDITIONS SHOULD CONTINUE THROUGH THE DAY TODAY...BUT SCATTERED SHOWERS COULD DEVELOP LATE INT HE AFTERNOON AND EVENING SO INDICATING VCSH AFTER 0000Z AT KALB AND KGFL. THERE COLD ALSO BE SOME LOWER CLOUDS BELOW 3000 FEET THAT BEGIN TO DEVELOP THIS EVENING AS THE FRONTAL BOUNDARY DRIFTS EAST AND A MORE HUMID AIRMASS SLOWLY BUILDS EAST ACROSS THE REGION. WINDS TONIGHT WILL GENERALLY BE LESS THAN 5 KNOTS BEFORE BECOMING SOUTHERLY WEDNESDAY AROUND 5-10 KNOTS. OUTLOOK... THURSDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA. FRIDAY: HIGH OPERATIONAL IMPACT. DEFINITE SHRA...TSRA. FRIDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE SHRA...TSRA. SATURDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA. SATURDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA. SUNDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA. SUNDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA. MONDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA. && .FIRE WEATHER... RAIN SHOWERS HAVE OCCURRED OVERNIGHT ACROSS MANY AREAS. THERE WILL BE A THREAT FOR RAIN SHOWERS AND THUNDERSTORMS OVER THE NEXT FEW DAYS...ESPECIALLY FOR THURSDAY NIGHT THROUGH FRIDAY NIGHT...WHEN A WIDESPREAD HEAVY RAINFALL IS EXPECTED. RH VALUES WILL FALL TO 40 TO 50 PERCENT THIS AFTERNOON ALONG WITH SOUTH WINDS AROUND 10 MPH. RH VALUES WILL RETURN TO NEAR 90 PERCENT TONIGHT WITH CONTINUED SOUTH WINDS AROUND 10 MPH. RH VALUES WILL FALL BACK TO 45 TO 55 PERCENT ON TOMORROW AFTN WITH STRONGER SOUTHERLY WINDS OF 10 TO 20 MPH. && .HYDROLOGY... RAINFALL OVERNIGHT FROM SHOWERS AND THUNDERSTORMS LEAD TO SOME VERY MINOR RISES /LESS THAN A HALF A FOOT/ ACROSS THE WESTERN MOHAWK VALLEY. DURING THE DAY TODAY...SOME ADDITIONAL SHOWERS OR THUNDERSTORMS WILL BE POSSIBLE OVER FAR WESTERN AREAS...BUT THIS WILL HAVE LIMITED IMPACT ON OUR HSA. ASIDE FROM AN ISOLATED SHOWER...MAINLY DRY CONDITIONS ARE EXPECTED FOR TONIGHT INTO TOMORROW. HOWEVER...AN APPROACHING FRONTAL BOUNDARY WILL RETURN WIDESPREAD RAIN TO THE REGION FOR LATE TOMORROW NIGHT THROUGH FRIDAY AND INTO FRIDAY NIGHT. MODERATE TO HEAVY RAINFALL IS POSSIBLE...WITH MOST AREAS EXPECTED TO RECEIVE ONE TO TWO INCHES OF RAINFALL. SOME SPOTS CAN LOCALLY SEE HIGHER AMOUNTS AS WELL. THIS RAINFALL WILL LEAD TO WITHIN BANK RISES ON RIVERS/STREAMS. AT THIS POINT...NO FLOODING IS EXPECTED...ALTHOUGH IF RAINFALL IS GREATER THAN EXPECTED...THEN MINOR RIVER FLOODING COULD BE POSSIBLE AT A FEW LOCATIONS. ALSO...SINCE THE RAINFALL IS EXPECTED TO FALL HEAVY IN A SHORT PERIOD OF TIME...MINOR NUISANCE FLOODING OF POOR DRAINAGE OR LOW LYING AREAS COULD BE POSSIBLE...SUCH AS IN URBAN AREAS. PONDING OF WATER IS EXPECTED ON ROADWAYS...MAKING FOR SLOWER TRAVEL. BEHIND THIS SYSTEM...SOME ISOLATED TO SCATTERED RAIN SHOWERS ARE POSSIBLE OVER THE WEEKEND...BUT COVERAGE SHOULD BE SMALL ENOUGH TO PREVENT ANY ADDITIONAL HYDROLOGIC CONCERNS. THIS SHOULD ALLOW RIVER AND STREAM LEVELS TO RECEDE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...FRUGIS NEAR TERM...FRUGIS SHORT TERM...FRUGIS LONG TERM...NAS AVIATION...NAS FIRE WEATHER...FRUGIS HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS MIAMI FL
1025 AM EDT WED MAY 14 2014 .UPDATE... MADE SOME SLIGHT ADJUSTMENTS TO THE SHORT TERM FORECAST. INITIALLY WAS GOING TO REDUCE THE POP`S ACROSS THE PENINSULA AND THE ATLANTIC WATERS. ALTHOUGH CURRENT COVERAGE OF SHOWERS HAS DIMINISHED FROM EARLIER THIS MORNING...ADDITIONAL LOW LEVEL MOISTURE CONTINUES TO ENTER THE REGION. THAT COUPLED WITH FAVORABLE UPPER LEVEL SPEED DIVERGENCE ACROSS THE REGION AND ADDITIONAL DAY TIME HEATING COULD RESULT IN MORE WIDESPREAD COVERAGE OF SHOWERS AND THUNDERSTORMS BY THIS AFTERNOON. HAVE SHIFTED MORE WIDESPREAD COVERAGE STARTING AROUND 20Z TO REFLECT THESE CONSIDERATIONS. 60 && .PREV DISCUSSION... /ISSUED 723 AM EDT WED MAY 14 2014/ AVIATION... SHOWERS ASSOCIATED WITH A SURFACE TROUGH OF LOW PRESSURE AND AN APPROACHING FRONTAL BOUNDARY WILL REMAIN LIKELY THROUGH THE 24 HR FORECAST PERIOD...ESPECIALLY ALONG THE EAST COAST WHERE SHOWERS CONTINUE TO DEVELOP AND SPREAD ASHORE FROM THE ATLANTIC. IN ADDITION TO THIS ACTIVITY...A FEW STORMS CAN`T BE RULED OUT. GUSTY EAST-SOUTHEAST WINDS WILL PERSIST THROUGH THE PERIOD AND GRADUALLY VEER TO THE SOUTH-SOUTHEAST ON THURSDAY AS THE FRONT APPROACHES. PERIODS WITH SUB-VFR CONDITIONS WILL BE POSSIBLE AS SHOWERS QUICKLY MOVE OVER/AROUND THE TERMINALS. 85/AG PREV DISCUSSION... /ISSUED 306 AM EDT WED MAY 14 2014/ .CORRECTED MISSPELLING IN SEVENTH LINE... SHORT TERM (TODAY-FRIDAY)... MOISTURE WILL BE ON THE INCREASE ACROSS SOUTH FLORIDA THROUGH THURSDAY AS A WEAK MID/UPPER LEVEL TROUGH APPROACHES FROM THE BAHAMAS. THIS TROUGH IS ROTATING AROUND THE BASE OF A LARGE RIDGE OVER THE ATLANTIC. AS THE LOW TRACKS ACROSS SOUTH FLORIDA LATE TODAY AND THURSDAY, LAPSE RATES WILL BECOME MORE CONDUCIVE FOR THUNDERSTORM DEVELOPMENT MAINLY DURING THE AFTERNOON AND EVENING HOURS, ALTHOUGH FORECAST SOUNDINGS ONLY SHOW MODEST INSTABILITY. ADJUSTED THE POPS FOR THIS MORNING BASED ON THIS AND THE FACT THE HRRR DOES NOT SHOW MUCH OUT THROUGH 18Z THIS AFTERNOON. FORECAST SOUNDINGS ALSO INDICATE THE PWAT INCREASING TO AROUND 1.8 INCHES TODAY AND CLOSE TO TWO INCHES ON THURSDAY WHICH IS SLIGHTLY ABOVE THE AVERAGE FOR MID MAY. THAT BEING SAID, THERE WILL BE AN INCREASING THREAT FOR THUNDER BUT THE STORMS ARE NOT EXPECTED TO BE SEVERE WITH GUSTY WINDS AND FREQUENT LIGHTNING STRIKES THE PRIMARY CONCERNS ALONG WITH THE BRIEF HEAVY RAIN. OVERALL RAINFALL AMOUNTS WILL NOT BE EXCESSIVE WITH WPC QPF ONLY DEPICTING ONE-HALF TO ONE INCH TOTALS THROUGH FRIDAY MORNING. THERE HOWEVER COULD BE LOCALLY HEAVIER AMOUNTS IN ISOLATED LOCATIONS WHEREVER ECHOES MOVE OVER THE SAME AREA. THE MORE IMPRESSIVE ASPECT OF THE UPCOMING WEATHER CONDITIONS IS A LARGE SCALE MID/UPPER TROUGH THAT HAS BEEN EVOLVING ACROSS THE CENTRAL/SOUTHERN PLAINS STATES THE PAST FEW DAYS. THIS TROUGH WILL BEGIN TO SHIFT EASTWARD ON FRIDAY IN RESPONSE TO A LARGE AMPLIFYING RIDGE ALONG THE COAST OF CALIFORNIA. THE WEAK TROUGH OVER SOUTH FLORIDA WILL BEGIN TO BECOME ABSORBED BY THE UPSTREAM TROUGH AND LIFT TO THE NORTHEAST ON FRIDAY ALLOWING FOR A LITTLE BIT OF DRYING TO THE AREA AS A LATE SEASON COLD FRONT MOVES ACROSS SOUTH FLORIDA DURING THE DAY WITH PWAT FALLING TO AROUND 1.5 INCHES. THIS WILL ALSO LEAD TO A DECREASING TREND IN SHOWER AND THUNDERSTORM COVERAGE. LONG TERM (SATURDAY-TUESDAY)... THE EXTENDED PERIOD LOOKS TO BE QUITE DRY WITH FORECAST SOUNDINGS SHOWING PWAT FALLING TO AROUND ONE-HALF INCH OVER THE WEEKEND AND INTO EARLY NEXT WEEK. THESE ARE QUITE IMPRESSIVE AND IF THIS MATERIALIZES, IT WILL BE LOWEST PWAT VALUES FOR MAY ACROSS SOUTH FLORIDA SINCE 1948. AS THE TROUGH EXITS TO THE EAST, A LARGE RIDGE WILL BUILD OVER THE GULF OF MEXICO WHICH WILL KEEP SOUTH FLORIDA IN A DRY, NORTHWESTERLY UPPER AIR FLOW THROUGH TUESDAY. MARINE... AN EAST SOUTHEAST WIND WILL CONTINUE THROUGH TODAY AT 15-20 KNOTS AND THEN SLOWLY DIMINISH TONIGHT AND THURSDAY INTO THE END OF THE WEEK WHILE VEERING TO THE SOUTHEAST TONIGHT THEN TO THE SOUTH ON THURSDAY AND SOUTHWEST ON THURSDAY NIGHT. THE WIND WILL THEN SHIFT TO THE NORTH AND INCREASE AGAIN TO THE 15-20 KNOT RANGE ON FRIDAY AS A COLD FRONT MOVES ACROSS THE LOCAL WATERS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 85 75 86 72 / 60 50 70 50 FORT LAUDERDALE 85 76 86 74 / 60 50 70 50 MIAMI 84 76 86 74 / 60 50 70 50 NAPLES 88 73 85 72 / 50 40 50 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR FLZ168-172- 173. AM...NONE. GM...NONE. && $$ SHORT TERM...85/AG LONG TERM....60/BD
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
930 AM EDT WED MAY 14 2014 .DISCUSSION... ...GUSTY ALONG THE SPACE/TREASURE COASTS TODAY... ...RAIN CHANCES INCREASE FOR TODAY AND ESPECIALLY THURSDAY... CURRENT...DEEP LAYER RIDGE PRESENTLY OVER FLORIDA AND THE SOUTHEAST UNITED STATE. DEEP SOUTHEAST FLOW AS INDICATED BY THE 915MHZ VERTICAL WIND PROFILER(S) AT THE SPACE CENTER AND THE MORNING SOUNDINGS FROM CAPE CANAVERAL...MIAMI AND KEY WEST. THE SOUNDINGS ALSO ARE REPORTING PRECIPITABLE WATER VALUES 1.7 TO 1.8 INCHES. THE RADAR MOSAIC LOOP IS SHOWING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN THE SOUTHEAST FLOW THAT ARE MOVING TO THE NORTHWEST AT AROUND 20 MPH PER THE AWIPS DISTANCE SPEED TOOL. THIS AFTERNOON...DEPENDING ON WHERE ONE IS LOCATED...SKIES WILL RANGE FROM PARTLY CLOUDY TO CLOUDY SO THE FORECAST CONSIDERABLE CLOUDINESS LOOKS TO BE A NICE AVERAGE FOR THE AFTERNOON. THE SHOWERS AND STORMS SHOULD INCREASE IN COVERAGE WITH DAYTIME HEATING. THE WINDS SHOULD INCREASE AS THE STRONGER WINDS JUST ABOVE THE SURFACE START MIXING DOWN LATE MORNING AND THROUGH THE AFTERNOON. THE LAKE WIND ADVISORY AT THE COAST FROM BREVARD TO MARTIN COUNTY LOOKS GOOD. AFTERNOON HIGH TEMPERATURES OF MID 80S AT THE COAST AND THE UPPER 80S TO AROUND 90 FOR THE INTERIOR ARE OK. PREVIOUS ZONES DISCUSSION CURRENT...ANOTHER WARM MORNING WITH CURRENT TEMPERATURES IN THE 70S AND MUGGY CONDITIONS EXIST WITH DEWPOINTS IN THE LOW 70S AREAWIDE. NEXRAD 88D SHOWS SCT SHOWERS/SPRINKLES OVER THE COASTAL WATERS OCCASIONALLY MAKING IT ONSHORE AND MAINLY DISSIPATING AS THEY PASS WEST OF I-95...WITH MARTIN COUNTY THE ONE EXCEPTION. AN ISOLATED RUMBLE OR THUNDER CANNOT BE RULED OUT EARLY THIS MORNING ALONG THE TREASURE COAST. A BRIEF DOWNPOUR CAN BE EXPECTED WITH THIS ACTIVITY. TODAY-TONIGHT...A FAIRLY TIGHT PRESSURE GRADIENT MOST EVERYWHERE TODAY WITH EAST TO EAST-SOUTHEAST WINDS INCREASING TO AROUND 15-20 MPH WITH HIGHER GUSTS ACROSS MUCH OF THE INTERIOR BY THIS AFTERNOON AND AROUND 20 MPH SUSTAINED NEAR THE SPACE/TREASURE COASTS WITH FREQUENT HIGHER GUSTS. WILL HOIST A LAKE WIND ADVISORY ALONG THE COAST FROM NORTH BREVARD THROUGH MARTIN COUNTY. WINDS WILL VEER TO SOUTHEAST THIS EVENING AND OVERNIGHT BUT WILL STAY ELEVATED NEAR 10 MPH ACROSS MUCH OF THE INTERIOR AND AROUND 15 MPH WITH HIGHER GUSTS ALONG THE COAST SOUTH FROM THE CAPE. DEEP LAYER MOISTURE WILL CONTINUE TO INCREASE ACROSS EAST CENTRAL FLORIDA THIS MORNING. GFS HINTS AT A DRIER POCKET OF AIR MOVING IN BEHIND THIS SURGE ACROSS THE EAST COAST IN THE AFTERNOON...BUT INCREASING VALUES AGAIN TONIGHT APPROACHING 1.80"-1.90". MAINLY SCATTERED SHOWERS WILL CONTINUE THIS MORNING OVER THE AREA AS THEY MOVE ON LAND FROM THE WESTERN ATLANTIC. AN ISOLATED LIGHTNING STORM ALSO REMAINS POSSIBLE THIS MORNING. INCREASING PRECIPITATION CHANCES THIS AFTERNOON INLAND FROM THE COAST AS THE EAST COAST SEA BREEZE MOVES INLAND PROVIDING A BOUNDARY FOR CONVECTIVE DEVELOPMENT ALONG WITH SURFACE HEATING. HIGHEST POPS THIS AFTERNOON EXPECTED INTO THE INTERIOR AND EVENTUALLY LATE DAY/EVENING INTO WEST CENTRAL FLORIDA. AFTER SHOWERS/ISOLD STORMS EXIT LATE TODAY TO THE WEST EXPECT A BRIEF LULL IN SHOWERS/ISOLATED STORMS...BUT WILL NOT RULE THEM OUT COMPLETELY EARLY THIS EVENING. EXPECT A NOCTURNAL INCREASE LATER IN THE EVENING AND OVERNIGHT AS ADDITIONAL MOISTURE SURGES INTO THE AREA AND WILL KEEP HIGHEST POPS ALONG THE COAST...DUE TO GREATER MOISTURE CONVERGENCE THERE. STILL EXPECTING MIDDLE 80S FOR HIGH TEMPERATURES ALONG THE COAST WITH UPPER 80S TO AROUND 90 DEGREE INLAND. LOWS CONTINUE MILD TONIGHT AND IN THE 70S. THU...HIGH MOISTURE WITH NEAR 2 INCHES PRECIPITABLE WATER WILL ADVECT NORTHWARD OVER THE AREA AHEAD OF A COOL FRONT APPROACHING FROM THE GULF OF MEXICO. WITH THIS BOUNDARY MOVING INTO A VERY MOIST AIR MASS...WILL HAVE TO WATCH FOR POTENTIAL OF HEAVY RAIN...ESPECIALLY IF WEAK LOW INDICATED BY THE MODELS IN THE EASTERN GULF MATERIALIZES AND PROVIDES MORE FOCUSED LOW LEVEL CONVERGENCE. MOS POPS ARE 70-80 PERCENT AND WITH VALUES LIKE THAT...GUIDANCE IS USUALLY DIFFICULT TO BEAT. EXPECT THAT THERE WILL BE CONSIDERABLE CLOUDINESS SO KNOCKED A COUPLE DEGREES OFF OF MOS MAX TEMPS WHICH WERE IN THE LOWER 90S AT MANY SITES. WITH SLIGHTLY LIMITED SURFACE HEATING AND AVERAGE LOOKING MID LEVEL TEMPS...THE MAIN THUNDERSTORM HAZARDS SHOULD BE LIGHTNING AND HEAVY RAINFALL. THE HEAVIER FRONTAL BAND PRECIP SHOULD GRADUALLY END FROM WEST TO EAST THU EVENING AND HAVE GENERALLY FOLLOWED MOS POPS WHICH ARE AROUND 40 PERCENT. SOME LINGERING LIGHT PRECIP MAY CONTINUE PAST MIDNIGHT ESPECIALLY IN THE SOUTH. FRI...THE FRONT IS FORECAST TO BE OFFSHORE BY SUNRISE WITH DRIER AIR ADVECTING IN. THE GFS SHOWS A SLIGHT CHANCE FOR RAIN IN THE MORNING ACROSS THE TREASURE COAST AND FOR CONTINUITY WITH PREVIOUS FORECAST...WILL LEAVE THIS SMALL CHANCE. WEAK COOL AIR ADVECTION WILL KEEP MAX TEMPS BELOW NORMAL...MAINLY LOWER 80S WITH SOME MID 80S INLAND. SAT-NEXT WED...FLOW ALOFT FLATTENS OUT OVER THE WEEKEND AND THEN TURNS NORTHWEST EARLY/MID WEEK. HIGH PRESSURE RIDGE WILL EXTEND OVER THE AREA BEHIND THE FRONT OVER THE WEEKEND. THIS WILL KEEP IT DRY AND TEMPS WILL RUN A FEW DEGREES BELOW NORMAL...WITH MINS MAINLY LOWER/MID 60S AND HIGHS IN THE MID 80S WITH A FEW UPPER 80S OVER THE INTERIOR. A WEAK BACK DOOR FRONT SLIDING OFFSHORE EARLY NEXT WEEK IS SHOWN BY THE GFS PRODUCING WEAK MOISTURE CONVERGENCE. MOS POPS ARE BELOW 20 PERCENT...SO WILL NOT INTRODUCE SHOWER CHANCES. TEMPS EARLY-MID WEEK LOOK AVERAGE...LOWS MID-UPPER 60S AND HIGHS MID-UPPER 80S. && .AVIATION... SHORT LIVED MVFR/IFR CEILINGS AS AREAS OF LOW CLOUDS...SHOWERS AND ISOLATED THUNDERSTORMS COME OFF THE OCEAN AND WORK THEIR WAY QUICKLY FROM THE COAST INLAND TO KLEE. FIRST FEW VISIBLE SATELLITE IMAGES INDICATE GOING VFR WITH STATUS FRAC AND STRATOCU/FL010-FL040 BEST BET FOR THE AFTERNOON. PREVIOUS AVIATION DISCUSSION GENERALLY VFR CONDITIONS TO CONTINUE...EXCEPT BRIEF MVFR IN WDLY SCT SHRA/ISOLD TSRA ACTIVITY...ESPECIALLY ALONG THE COAST THIS MORNING...TRANSITIONING INTO THE INTERIOR THIS AFTERNOON WITH THE EAST COAST SEA BREEZE. HIGHER SHRA/ISOLD TSRA ACROSS CNTRL/WCNTRL THIS AFTERNOON/EVENING. GUSTY ESE WINDS EXPECTED TODAY WITH SPEEDS INCREASING TO AROUND 15 KTS INTERIOR WITH HIGHER GUSTS BY AFTERNOON. FROM KTIX-KMLB-KVRB-KFPR-KSUA ESE WINDS INCREASING TO 15-20 KTS WITH FREQUENT GUSTS TO AROUND 25 KTS IN THE AFTERNOON. NOCTURNAL SHRA/ISOLD TSRA TONIGHT AS ADDITIONAL MOISTURE SURGES INTO THE AREA AND FRONTAL BOUNDARY TO THE WEST SLOWLY APPROACHES. && .MARINE... CURRENT-THIS AFTERNOON...THE NOAA AND SCRIPPS BUOYS FROM 4NM OFF PORT CANAVERAL TO 12NM EAST OF NEW SMYRNA BEACH WERE RECORDING SOUTHEAST WINDS 15 TO 20 KNOTS AND SEAS RANGING FROM 4 FEET AT 4 AND 6NM OFF THE BEACH TO 5 TO 6 FEET FROM 20NM TO 120NM OFFSHORE. THE LATEST RUC 12 HOUR FORECAST SERIES SHOWS A 3 MB GRADIENT FROM AROUND MIAMI TO JACKSONVILLE. THIS GRADIENT SHOULD SUPPORT 15 TO 20 KNOT WINDS. FOR THE AFTERNOON AND EVENING THE SMALL CRAFT EXERCISE CAUTION IS GOOD. THE GRADIENT TIGHTENS MORE LATE OVERNIGHT AS THE FRONT CURRENTLY OVER MISSISSIPPI AND WESTERN TENNESSEE MOVES EAST TO THE FLORIDA PANHANDLE AND NORTHEAST GULF OF MEXICO. PREVIOUS MARINE DISCUSSION TODAY-TONIGHT...ESE WINDS 15-20 KTS ACROSS MUCH OF THE COASTAL WATERS THRU THE PERIOD. SEAS BUILDING TO 4-6 FT NEAR SHORE SOUTH OF THE BREVARD-VOLUSIA COUNTY LINE AND 5-6 FT OFFSHORE. WILL CONTINUE CAUTIONARY STATEMENTS FOR SMALL CRAFT FOR ALL MARINE ZONES EXCEPT NEAR SHORE VOLUSIA COUNTY. BORDERLINE SCA CONDITIONS LATE THIS AFTERNOON/EVENING AWAY FROM THE COAST AS WINDS APPROACH 20 KTS AND SEA BUILD TO 6 FT. WILL BRIEF DAY SHIFT AND ALLOW THEM TO UPGRADE FOR LATE TODAY OR TONIGHT IF NECESSARY. THU-FRI...POOR TO MARGINALLY HAZARDOUS BOATING CONDITIONS AHEAD/BEHIND COOL FRONT. SOUTHERLY WINDS WILL BE 15-20 KNOTS THU THEN BECOME NORTHWEST EARLY FRI. A HIGH COVERAGE OF SHOWERS/STORMS WILL OCCUR THU INTO THU EVENING THEN FRI LOOKS DRY EXCEPT FOR FAR SOUTHERN WATERS IN THE MORNING. WEEKEND...HIGH PRESSURE RIDGE BUILDING ACROSS NORTH FLORIDA WILL PROVIDE A MAINLY NORTHEAST WIND FLOW. SPEEDS LOOK TO BE 10-15 KNOTS AND AROUND 15 KNOTS IN THE GULF STREAM. && .PRELIMINARY POINT TEMPS/POPS... DAB 85 74 88 62 / 50 50 70 40 MCO 89 72 89 65 / 50 40 70 40 MLB 87 76 90 65 / 50 50 70 40 VRB 86 76 87 68 / 50 50 70 40 LEE 89 72 86 62 / 50 40 70 40 SFB 90 73 89 64 / 50 40 70 40 ORL 89 74 89 65 / 50 40 70 40 FPR 85 75 87 69 / 50 50 70 40 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...LAKE WIND ADVISORY FROM 10 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR INDIAN RIVER-MARTIN-NORTHERN BREVARD-SOUTHERN BREVARD-ST. LUCIE. AM...NONE. && $$ SHORT TERM/AVIATION...WIMMER LONG TERM/IMPACT WX...PENDERGRAST
AREA FORECAST DISCUSSION
NWS MIAMI FL
723 AM EDT WED MAY 14 2014 .AVIATION... SHOWERS ASSOCIATED WITH A SURFACE TROUGH OF LOW PRESSURE AND AN APPROACHING FRONTAL BOUNDARY WILL REMAIN LIKELY THROUGH THE 24 HR FORECAST PERIOD...ESPECIALLY ALONG THE EAST COAST WHERE SHOWERS CONTINUE TO DEVELOP AND SPREAD ASHORE FROM THE ATLANTIC. IN ADDITION TO THIS ACTIVITY...A FEW STORMS CAN`T BE RULED OUT. GUSTY EAST-SOUTHEAST WINDS WILL PERSIST THROUGH THE PERIOD AND GRADUALLY VEER TO THE SOUTH-SOUTHEAST ON THURSDAY AS THE FRONT APPROACHES. PERIODS WITH SUB-VFR CONDITIONS WILL BE POSSIBLE AS SHOWERS QUICKLY MOVE OVER/AROUND THE TERMINALS. 85/AG && .PREV DISCUSSION... /ISSUED 306 AM EDT WED MAY 14 2014/ ..CORRECTED MISSPELLING IN SEVENTH LINE... SHORT TERM (TODAY-FRIDAY)... MOISTURE WILL BE ON THE INCREASE ACROSS SOUTH FLORIDA THROUGH THURSDAY AS A WEAK MID/UPPER LEVEL TROUGH APPROACHES FROM THE BAHAMAS. THIS TROUGH IS ROTATING AROUND THE BASE OF A LARGE RIDGE OVER THE ATLANTIC. AS THE LOW TRACKS ACROSS SOUTH FLORIDA LATE TODAY AND THURSDAY, LAPSE RATES WILL BECOME MORE CONDUCIVE FOR THUNDERSTORM DEVELOPMENT MAINLY DURING THE AFTERNOON AND EVENING HOURS, ALTHOUGH FORECAST SOUNDINGS ONLY SHOW MODEST INSTABILITY. ADJUSTED THE POPS FOR THIS MORNING BASED ON THIS AND THE FACT THE HRRR DOES NOT SHOW MUCH OUT THROUGH 18Z THIS AFTERNOON. FORECAST SOUNDINGS ALSO INDICATE THE PWAT INCREASING TO AROUND 1.8 INCHES TODAY AND CLOSE TO TWO INCHES ON THURSDAY WHICH IS SLIGHTLY ABOVE THE AVERAGE FOR MID MAY. THAT BEING SAID, THERE WILL BE AN INCREASING THREAT FOR THUNDER BUT THE STORMS ARE NOT EXPECTED TO BE SEVERE WITH GUSTY WINDS AND FREQUENT LIGHTNING STRIKES THE PRIMARY CONCERNS ALONG WITH THE BRIEF HEAVY RAIN. OVERALL RAINFALL AMOUNTS WILL NOT BE EXCESSIVE WITH WPC QPF ONLY DEPICTING ONE-HALF TO ONE INCH TOTALS THROUGH FRIDAY MORNING. THERE HOWEVER COULD BE LOCALLY HEAVIER AMOUNTS IN ISOLATED LOCATIONS WHEREVER ECHOES MOVE OVER THE SAME AREA. THE MORE IMPRESSIVE ASPECT OF THE UPCOMING WEATHER CONDITIONS IS A LARGE SCALE MID/UPPER TROUGH THAT HAS BEEN EVOLVING ACROSS THE CENTRAL/SOUTHERN PLAINS STATES THE PAST FEW DAYS. THIS TROUGH WILL BEGIN TO SHIFT EASTWARD ON FRIDAY IN RESPONSE TO A LARGE AMPLIFYING RIDGE ALONG THE COAST OF CALIFORNIA. THE WEAK TROUGH OVER SOUTH FLORIDA WILL BEGIN TO BECOME ABSORBED BY THE UPSTREAM TROUGH AND LIFT TO THE NORTHEAST ON FRIDAY ALLOWING FOR A LITTLE BIT OF DRYING TO THE AREA AS A LATE SEASON COLD FRONT MOVES ACROSS SOUTH FLORIDA DURING THE DAY WITH PWAT FALLING TO AROUND 1.5 INCHES. THIS WILL ALSO LEAD TO A DECREASING TREND IN SHOWER AND THUNDERSTORM COVERAGE. LONG TERM (SATURDAY-TUESDAY)... THE EXTENDED PERIOD LOOKS TO BE QUITE DRY WITH FORECAST SOUNDINGS SHOWING PWAT FALLING TO AROUND ONE-HALF INCH OVER THE WEEKEND AND INTO EARLY NEXT WEEK. THESE ARE QUITE IMPRESSIVE AND IF THIS MATERIALIZES, IT WILL BE LOWEST PWAT VALUES FOR MAY ACROSS SOUTH FLORIDA SINCE 1948. AS THE TROUGH EXITS TO THE EAST, A LARGE RIDGE WILL BUILD OVER THE GULF OF MEXICO WHICH WILL KEEP SOUTH FLORIDA IN A DRY, NORTHWESTERLY UPPER AIR FLOW THROUGH TUESDAY. MARINE... AN EAST SOUTHEAST WIND WILL CONTINUE THROUGH TODAY AT 15-20 KNOTS AND THEN SLOWLY DIMINISH TONIGHT AND THURSDAY INTO THE END OF THE WEEK WHILE VEERING TO THE SOUTHEAST TONIGHT THEN TO THE SOUTH ON THURSDAY AND SOUTHWEST ON THURSDAY NIGHT. THE WIND WILL THEN SHIFT TO THE NORTH AND INCREASE AGAIN TO THE 15-20 KNOT RANGE ON FRIDAY AS A COLD FRONT MOVES ACROSS THE LOCAL WATERS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 85 75 86 72 / 60 50 70 50 FORT LAUDERDALE 85 76 86 74 / 60 50 70 50 MIAMI 84 76 86 74 / 60 50 70 50 NAPLES 88 73 85 72 / 40 40 50 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR FLZ168-172-173. AM...NONE. GM...NONE. && $$ SHORT TERM...13/SI LONG TERM....30/KOB AVIATION...13/SI Area Forecast Discussion National Weather Service Lincoln IL 1041 AM CDT Wed May 14 2014 .DISCUSSION... ISSUED 1036 AM CDT Wed May 14 2014 Deep trof aloft associated with developing low over the Gulf Coast this morning. Plenty of moisture streaming into the region and rain is spreading across the Midwest. Though the activity is currently focused just north of the Ohio River Valley, HRRR model is persistent in continuing to develop and spread out the precipitation through the afternoon. Going forecast is doing well with temperatures almost holding steady/barely rising and PoPs increasing through the afternoon and into the evening. Not planning any updates to the forecast at this time. HJS && .AVIATION... ISSUED 618 AM CDT Wed May 14 2014 All sites will begin as VFR as mid and high clouds will be over the entire area this morning, in advance of the next weather system coming up from the south. Some uncertainty to the timing of the pcpn starting, but best estimate is around 18z at CMI and then spreading westward, reaching PIA around 21z. Conditions will be VFR to start, but conditions will get worse as the afternoon progresses into the evening. More steady rain will move into the area, affecting the TAFs with vis around 3-4sm and cigs 1.5kft in the east, to 2.5kft in the west. Around midnight, conditions will decrease again, dropping below MVFR to IFR conditions CMI, DEC, and BMI. PIA and SPI will see lower MVFR conditions with vis down to 3sm and cigs around 1.5kft. Winds will be northerly through the period, but increasing in speed as the gradient tightens in response to the low pressure area moving up the line into the area. Could also be some gusty winds during the evening and overnight hours as the low moves into westerly IND. Auten && .PREV DISCUSSION... ISSUED 330 AM CDT Wed May 14 2014 SHORT TERM...Today through Saturday night An unsettled weather pattern looks to continue across central and southeast IL the next few days along with cool temperatures. 00Z short range models are in fair agreement next few days and models show much of CWA will see another round of showers today and tonight and heaviest over eastern/se IL where around 1 inch or more of rain expected. Early morning surface map shows a frontal boundary stretched from nw Ohio through mid KY/TN and central MS/LA. 1015 mb surface low pressure was near the LA coast. Radar mosaic shows showers se of a Danville to Charleston to Effingham line and lifting nne into east central and especially se IL. A few heavier showers near the Wabash river while thunderstorms are further se in warm sector over TN and southern KY. Cooler temps are in the upper 40s north of I-72 and lower 50s from I-72 south. Aloft a strong upper level trof was over the Great Plains with strong upper level ridges off the Atlantic and west coasts. Models shows surface low pressure over the southern MS river valley strengthening as it ejects nne along frontal boundary reaching southern Indiana by midnight tonight and into eastern lower MI by early afternoon Thu. Water vapor loop shows a tropical plume of deep moisture streaming northward from the western gulf of Mexico into IL so this could bring some heavy rains around 1 inch or more over eastern IL today into tonight. NW areas will likely stay dry this morning but see rain chances increase during the afternoon and evening. SPC keeps slight risk of severe storms se of IL today with chance of thunderstorms over far se IL near the Wabash river. Tropical plume of moisture shifts east/ne of central IL during overnight though strong upper level trof moving into IL Thu and Fri to keep good chances of rain showers around especially during the afternoon and early evening hours. Sided toward cooler highs in the mid 50s to near 60F through Friday due to abundant cloud cover and cooling 850 mb temps. Lows in the upper 30s and lower 40s Thu and Fri night and thinking Friday night to be the coolest night. Strong/large upper level trof starts to pull ne into Great Lakes region Sat so just have isolated showers possible with more peaks of sunshine and highs in the lower 60s, with a few upper 50s from I-74 ne. LONG TERM...Sunday through Wednesday Extended models shower upper level ridge shifting east into the MS river valley early next work week with below normal temperatures this weekend moderating closer to normal by middle of next week. Dry conditions looks to prevail Sunday through Monday across central/se IL. Then short waves riding over top of upper level ridge along with developing frontal boundary from central plains into central IL to bring isolated convection to mainly northern areas from Monday night through Wed. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1125 AM EDT WED MAY 14 2014 .UPDATE... ISSUED AT 1120 AM EDT WED MAY 14 2014 THE HOURLY GRIDS HAVE BEEN UPDATED MAINLY FOR RECENT SATELLITE...RADAR AND OBSERVATION TRENDS. MID LEVEL RIDGING LONG THE EASTERN SEABOARD WILL CONTINUE TO SHIFT SHIFT EAST THROUGH THIS EVENING AS A TROUGH OVER THE CENTRAL US GRADUALLY MOVES EAST INTO THE MS VALLEY REGION. A SHORTWAVE WITHIN THIS TROUGH WILL MOVE FROM THE SOUTHERN PLAINS TO THE MID MS VALLEY BY LATE THIS EVENING. THIS WILL LEAD TO A SFC WAVE DEVELOPING ALONG A BOUNDARY THAT HAS STALLED OUT BETWEEN THE INTERSTATE 65 AND INTERSTATE 75 CORRIDORS IN KY. AS THIS LOW TRACKS INTO WESTERN KY THIS EVENING...THIS WILL BACK THE LOW LEVEL FLOW A BIT TOWARD THE SOUTHEAST WHILE THE UPPER LEVEL WINDS WILL BE GENERALLY SOUTHERLY. THE SFC LOW SHOULD REACH NORTHEAST IN/NORTHWEST OH REGION BY DAWN ON THURSDAY AND THIS LOW WILL SEND THE BOUNDARY EAST AS A COLD FRONT INTO EASTERN KY LATE TONIGHT...BUT NOT EXIT INTO WV UNTIL AROUND MIDDAY ON THU. PW IS PROGGED TO CLIMB TO AROUND 1.5 INCHES OR HIGHER BY LATE THIS EVENING INTO THE OVERNIGHT HOURS IN THE DEEP SOUTHERLY FLOW. THESE VALUES ARE BETWEEN THE 75TH PERCENTILE AND 2 SD ABOVE NORMAL. RECENT RUNS OF THE NEAR TERM MODELS SUCH AS THE RAP...HRRR AND THE 12Z NAM SUGGEST MOSTLY JUST ISOLATED TO POSSIBLY SCATTERED COVERAGE OF CONVECTION THROUGH ABOUT SUNSET WITH THE HEATING OF THE DAY AS LI IS PROGGED TO REACH -5C OR LOWER AND CAPE TO REACH NEAR 2000 J/KG. MORE WIDESPREAD ACTIVITY IS ANTICIPATED LATER INTO THE EVENING AND INTO THE OVERNIGHT HOURS. THE SHORTWAVE WILL BEGIN TO TAKE ON MORE OF A NEGATIVE TILT AS IT APPROACHES THE OH VALLEY REGION WHICH SHOULD LEAD TO UPPER LEVEL DIFFLUENT FLOW AND DEEPER LIFT WITHIN THE DEEP MOISTURE LAYER. THE INCREASED SHEAR IN THE LATE AFTERNOON AND ESPECIALLY THE EVENING SHOULD LEAD TO MORE STORM ORGANIZATION COMPARED TO THIS AFTERNOON AND THE THREAT FOR SOME STRONG TO DAMAGING WINDS AND MARGINALLY SEVERE HAIL. ANY SUPERCELLS THAT DEVELOP...ESPECIALLY ALONG OR WEST OF I 75 AND OVER OUR NW COUNTIES WOULD HAVE THE POTENTIAL TO PRODUCE AN ISOLATED TORNADO. HOWEVER...HEAVY RAIN COULD END UP BEING THE BIGGEST THREAT. WITH THE PW FORECAST TO BE AS HIGH AS IT IS...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE. THE THREAT WILL LINGER IN EASTERN LOCATIONS UNTIL THE FRONT MOVES INTO WV. THE LOCALLY HEAVY RAIN THREAT HAS BEEN ADDED TO THE GRIDS AND THE HWO HAS BEEN UPDATED ACCORDINGLY. UPDATE ISSUED AT 639 AM EDT WED MAY 14 2014 A FEW SHOWERS HAVE DEVELOPING AND ARE MOVING NORTH NEAR THE I-64 CORRIDOR. THESE SHOULD LIFT NORTH OVER THE NEXT FEW HOURS. OTHERWISE...LOOKS LIKE A FAIRLY QUIET START TO THE DAY IN THE WAKE OF THIS MORNINGS SHOWER ACTIVITY. HRRR AND RAP REALLY TARGET THE WESTERN COUNTIES IN THE FORECAST AREA THIS AFTERNOON. BASED ON RADAR TRENDS THIS SEEMS REASONABLE...BUT AS WE SAW YESTERDAY...IF STORMS DEVELOP...OUTFLOW BOUNDARIES MAY PUSH THINGS FURTHER EAST BY LATE IN THE DAY. NO SIGNIFICANT UPDATE PLANNED THIS MORNING EXCEPT TO ADJUST TEMPERATURES FOR LATEST TRENDS. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 314 AM EDT WED MAY 14 2014 PRESENTLY...A POTENT SHORTWAVE TROUGH IS PUSHING ITS WAVE EAST ACROSS WEST TEXAS WITH A SFC FRONTAL BOUNDARY STRETCHING FROM NORTHWEST INDIANA...SOUTHWARD INTO SOUTHERN ILLINOIS...AND INTO EASTERN TEXAS. THIS FRONTAL BOUNDARY WILL SERVE AS THE FOCUS FOR AN AREA OF LOW PRESSURE TO DEVELOP THIS AFTERNOON AND EVENING AS THE MID LEVEL TROUGH PUSHES INTO THE LOWER MISSISSIPPI RIVER VALLEY. THIS SURFACE LOW WILL TRACK NORTHEAST FROM WESTERN KENTUCKY LATE TODAY...INTO THE SOUTHERN GREAT LAKES BY THURSDAY MORNING. SOUTHERLY FLOW WILL CONTINUE TO PUMP MOIST SFC CONDITIONS INTO EASTERN KENTUCKY THROUGH THE DAY. AS THE LOW APPROACHES FROM THE WEST...SHOWERS AND STORMS WILL RAMP UP THROUGH THE DAY. BASED ON LATEST SATELLITE/RADAR...LOOKS LIKE A CLUSTER OF STORMS WILL MOVE ACROSS CENTRAL KENTUCKY THIS MORNING. THIS COULD SEND SOME OUTFLOW BOUNDARIES TO THE EAST INTO EASTERN KENTUCKY AND SET THE STAGE FOR STORM DEVELOPMENT LATER TODAY. SHEAR IS NOT FANTASTIC...BUT IT LOOKS LIKE INSTABILITY SHOULD BE FAIRLY GOOD...SUPPORTING THE THREAT FOR SEVERE STORMS. IN FACT...NEARLY ALL OF EASTERN KENTUCKY RESIDES IN A SLIGHT RISK OF SEVERE THUNDERSTORMS THROUGH THE DAY. MAIN THREATS APPEAR TO BE DAMAGING WINDS...BUT CANNOT RULE OUT A FEW ROTATING SUPERCELLS...ESPECIALLY TOWARDS THE I-75 CORRIDOR...AND THUS AN ISOLATED TORNADO WOULD ALSO BE POSSIBLE. GIVEN WET BULB FREEZING HEIGHTS AROUND 10KFT...SOME HAIL WILL ALSO BE POSSIBLE WITH THE STRONGER CELLS. SEEMS CONDITIONS ARE TRENDING TOWARDS SUPPORTING A BETTER THREAT OF SEVERE STORMS TODAY. AS THE SFC LOW TRACKS NORTHEAST TONIGHT...THE FRONTAL BOUNDARY WILL FINALLY BE ON THE MOVE AND TRACK EAST INTO EASTERN KENTUCKY. WITH GOOD CONVERGENCE AND FORCING ANTICIPATED...WE SHOULD SEE WIDESPREAD SHOWERS AND STORMS THROUGH A GOOD PORTION OF THE NIGHT. A RISK OF A FEW SEVERE STORMS COULD CONTINUE WELL INTO THE NIGHT UNTIL THE FRONTAL BOUNDARY PUSHES ON THROUGH. SHOWERS AND STORMS WILL WIND DOWN INTO THE MIDDAY HOURS ON THURSDAY AS THE FRONT EXITS TO THE EAST. THUS...BY MID TO LATE AFTERNOON...DRY WEATHER SHOULD RETURN. MILD AND HUMID CONDITIONS WILL CONTINUE THROUGH TODAY. WITH THE PASSAGE OF THE COLD FRONT TONIGHT AND THURSDAY...MUCH COOLER WEATHER WILL RETURN THROUGH THE DAY THURSDAY WITH THE HIGHER HUMIDITY ALSO EXITING. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 314 AM EDT WED MAY 14 2014 THE MODELS ARE IN A BIT BETTER AGREEMENT THIS NIGHT FOR THE MID LEVELS DURING THE FIRST PART OF THE EXTENDED. THEY ALL SHOW A LARGE AND DEEP LOW CENTERED OVER THE UPPER MIDWEST AT 00Z FRIDAY WITH A SWEEP OF WEAKENING ENERGY CROSSING EAST KENTUCKY ALONG WITH BETTER HEIGHT FALLS. THE MODEL AGREEMENT STARTS TO WANE BY MIDDAY FRIDAY WHEN THE GEM HOLDS ON TO A STRONGER LOW FURTHER SOUTH THAN THE SIMILAR GFS AND ECMWF. THE SOLID AGREEMENT OF THE LATTER TWO MODELS CONTINUE INTO SATURDAY MORNING WITH THEIR UPPER LOW NOW NORTH OF THE GREAT LAKES AND KENTUCKY ON THE SOUTHERN FRINGE OF THIS SLOW MOVING TROUGH. PACKETS OF SHORTWAVE ENERGY MOVING THROUGH THE BASE OF THIS TROUGH WILL CONTINUE TO PASS THROUGH THE STATE WITH ONE LAST BATCH CROSSING OVERHEAD LATER THAT NIGHT WITH THE PASSAGE OF THE 500MB TROUGH AXIS. AT THIS POINT THE ECMWF...IN A SWAP OF POSITIONS WITH THE GFS...STARTS TO AMPLIFY THE REMAINS OF THE LOW JUST TO THE NORTHEAST OF KENTUCKY WHILE THE GFS KEEPS THE CORE OF ITS TROUGH FURTHER NORTH. BY SUNDAY NIGHT...THE TROUGHING WILL STILL BE IN CONTROL OF THE WEATHER OVER EAST KENTUCKY...THOUGH THE ECMWF IS CERTAINLY MORE AMPLIFIED WITH ITS SOUTHERN CLOSED LOW IN CONTRAST TO THE OPEN TROUGH FROM THE GFS CENTERED NORTH OF LAKE EERIE. REGARDLESS...THIS DEVELOPMENT WILL LIKELY KEEP CYCLONIC FLOW OVER THE AREA INTO THE START OF THE NEW WEEK AND ALSO PREVENT MUCH IN THE WAY OF RIDGING FROM MOVING IN FROM THE PLAINS. TO CLOSE OUT THE EXTENDED...THE ECMWF DEPICTS AN OMEGA BLOCK OVER THE UNITED STATES WITH ITS EASTERN LOW CENTERED JUST OFF THE MID ATLANTIC COAST... FURTHER WEST THAN THE GFS VERSION...BUT ALSO STRONG AND BROAD ENOUGH TO STILL DOMINATE THE WX FOR THE JKL CWA. FAVORED A GENERAL MODEL BLEND EARLY IN THE EXTENDED THEN A LEAN TOWARD THE MORE AMPLIFIED AND BLOCKY ECMWF FOR THE LATTER PART...THOUGH PREFERRED A MORE GRADUAL EVOLUTION THAN WHAT IT PORTRAYED THROUGH THE WEEKEND. SENSIBLE WEATHER WILL FEATURE MUCH COOLER AIR MOVING INTO EAST KENTUCKY IN THE WAKE OF A DEPARTING COLD FRONT. AS THE UPPER LOW CYCLES OVERHEAD...A FEW SHOWERS WILL BE POSSIBLE THROUGH THE START OF THE WEEKEND BEFORE DRIER AIR AND A STRENGTHENING AREA OF HIGH PRESSURE WIN OUT AND LIKELY KEEP THE WEATHER QUIET INTO THE START OF THE NEW WORK WEEK. THIS SFC HIGH...AND A LOW SHAPING UP WELL TO THE EAST OF THE AREA...SHOULD SUPPRESS A DEVELOPING WARM FRONT TO THE SOUTH OF THE AREA KEEPING DRY AND SEASONABLY COOL WEATHER GOING THROUGH TUESDAY. THE CR GRID LOAD CAME IN REASONABLE FOR THE BULK OF THE EXTENDED... THOUGH DID MAKE SOME ADJUSTMENTS TOWARD THE LATEST ECMWF SOLUTION LATER ON AND ALSO TO EMPHASIZE MORE OF A DIURNAL COMPONENT TO THE SHOWERS FRIDAY INTO SATURDAY MORNING. DID ALSO FINE TUNE THE LOW TEMPERATURE GRIDS FROM SUNDAY THROUGH TUESDAY MORNING TO BETTER DEPICT RIDGE AND VALLEY DETAILS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 639 AM EDT WED MAY 14 2014 AN APPROACHING COLD FRONT WILL BE THE FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT ACROSS EASTERN KENTUCKY TODAY AND TONIGHT. THUNDERSTORM ACTIVITY MAY BE SLOW TO MOVE INTO THE TAF SITES TODAY...BUT SHOULD EVENTUALLY SPREAD INTO FAR EASTERN KENTUCKY BY LATE IN THE DAY OR THIS EVENING. GOING TO KEEP EVERYTHING VFR INTO TONIGHT...ALTHOUGH WE SHOULD SEE SOME LOWER CIGS AND VISBYS WITH THE THUNDERSTORMS LATE TODAY AND TONIGHT. OF COURSE ANTICIPATING THUNDERSTORM DEVELOPMENT BEYOND 9 TO 12 HOURS IS HARD TO DO...SO WILL REMAIN GENERIC WITH THUNDERSTORM MENTION IN THE TAFS UNTIL WE CAN GET SOME BETTER CONFIDENCE ON WHEN AND WHERE STORMS MAY DEVELOP. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...KAS LONG TERM...GREIF AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
639 AM EDT WED MAY 14 2014 .UPDATE... ISSUED AT 639 AM EDT WED MAY 14 2014 A FEW SHOWERS HAVE DEVELOPING AND ARE MOVING NORTH NEAR THE I-64 CORRIDOR. THESE SHOULD LIFT NORTH OVER THE NEXT FEW HOURS. OTHERWISE...LOOKS LIKE A FAIRLY QUIET START TO THE DAY IN THE WAKE OF THIS MORNINGS SHOWER ACTIVITY. HRRR AND RAP REALLY TARGET THE WESTERN COUNTIES IN THE FORECAST AREA THIS AFTERNOON. BASED ON RADAR TRENDS THIS SEEMS REASONABLE...BUT AS WE SAW YESTERDAY...IF STORMS DEVELOP...OUTFLOW BOUNDARIES MAY PUSH THINGS FURTHER EAST BY LATE IN THE DAY. NO SIGNIFICANT UPDATE PLANNED THIS MORNING EXCEPT TO ADJUST TEMPERATURES FOR LATEST TRENDS. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 314 AM EDT WED MAY 14 2014 PRESENTLY...A POTENT SHORTWAVE TROUGH IS PUSHING ITS WAVE EAST ACROSS WEST TEXAS WITH A SFC FRONTAL BOUNDARY STRETCHING FROM NORTHWEST INDIANA...SOUTHWARD INTO SOUTHERN ILLINOIS...AND INTO EASTERN TEXAS. THIS FRONTAL BOUNDARY WILL SERVE AS THE FOCUS FOR AN AREA OF LOW PRESSURE TO DEVELOP THIS AFTERNOON AND EVENING AS THE MID LEVEL TROUGH PUSHES INTO THE LOWER MISSISSIPPI RIVER VALLEY. THIS SURFACE LOW WILL TRACK NORTHEAST FROM WESTERN KENTUCKY LATE TODAY...INTO THE SOUTHERN GREAT LAKES BY THURSDAY MORNING. SOUTHERLY FLOW WILL CONTINUE TO PUMP MOIST SFC CONDITIONS INTO EASTERN KENTUCKY THROUGH THE DAY. AS THE LOW APPROACHES FROM THE WEST...SHOWERS AND STORMS WILL RAMP UP THROUGH THE DAY. BASED ON LATEST SATELLITE/RADAR...LOOKS LIKE A CLUSTER OF STORMS WILL MOVE ACROSS CENTRAL KENTUCKY THIS MORNING. THIS COULD SEND SOME OUTFLOW BOUNDARIES TO THE EAST INTO EASTERN KENTUCKY AND SET THE STAGE FOR STORM DEVELOPMENT LATER TODAY. SHEAR IS NOT FANTASTIC...BUT IT LOOKS LIKE INSTABILITY SHOULD BE FAIRLY GOOD...SUPPORTING THE THREAT FOR SEVERE STORMS. IN FACT...NEARLY ALL OF EASTERN KENTUCKY RESIDES IN A SLIGHT RISK OF SEVERE THUNDERSTORMS THROUGH THE DAY. MAIN THREATS APPEAR TO BE DAMAGING WINDS...BUT CANNOT RULE OUT A FEW ROTATING SUPERCELLS...ESPECIALLY TOWARDS THE I-75 CORRIDOR...AND THUS AN ISOLATED TORNADO WOULD ALSO BE POSSIBLE. GIVEN WET BULB FREEZING HEIGHTS AROUND 10KFT...SOME HAIL WILL ALSO BE POSSIBLE WITH THE STRONGER CELLS. SEEMS CONDITIONS ARE TRENDING TOWARDS SUPPORTING A BETTER THREAT OF SEVERE STORMS TODAY. AS THE SFC LOW TRACKS NORTHEAST TONIGHT...THE FRONTAL BOUNDARY WILL FINALLY BE ON THE MOVE AND TRACK EAST INTO EASTERN KENTUCKY. WITH GOOD CONVERGENCE AND FORCING ANTICIPATED...WE SHOULD SEE WIDESPREAD SHOWERS AND STORMS THROUGH A GOOD PORTION OF THE NIGHT. A RISK OF A FEW SEVERE STORMS COULD CONTINUE WELL INTO THE NIGHT UNTIL THE FRONTAL BOUNDARY PUSHES ON THROUGH. SHOWERS AND STORMS WILL WIND DOWN INTO THE MIDDAY HOURS ON THURSDAY AS THE FRONT EXITS TO THE EAST. THUS...BY MID TO LATE AFTERNOON...DRY WEATHER SHOULD RETURN. MILD AND HUMID CONDITIONS WILL CONTINUE THROUGH TODAY. WITH THE PASSAGE OF THE COLD FRONT TONIGHT AND THURSDAY...MUCH COOLER WEATHER WILL RETURN THROUGH THE DAY THURSDAY WITH THE HIGHER HUMIDITY ALSO EXITING. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 314 AM EDT WED MAY 14 2014 THE MODELS ARE IN A BIT BETTER AGREEMENT THIS NIGHT FOR THE MID LEVELS DURING THE FIRST PART OF THE EXTENDED. THEY ALL SHOW A LARGE AND DEEP LOW CENTERED OVER THE UPPER MIDWEST AT 00Z FRIDAY WITH A SWEEP OF WEAKENING ENERGY CROSSING EAST KENTUCKY ALONG WITH BETTER HEIGHT FALLS. THE MODEL AGREEMENT STARTS TO WANE BY MIDDAY FRIDAY WHEN THE GEM HOLDS ON TO A STRONGER LOW FURTHER SOUTH THAN THE SIMILAR GFS AND ECMWF. THE SOLID AGREEMENT OF THE LATTER TWO MODELS CONTINUE INTO SATURDAY MORNING WITH THEIR UPPER LOW NOW NORTH OF THE GREAT LAKES AND KENTUCKY ON THE SOUTHERN FRINGE OF THIS SLOW MOVING TROUGH. PACKETS OF SHORTWAVE ENERGY MOVING THROUGH THE BASE OF THIS TROUGH WILL CONTINUE TO PASS THROUGH THE STATE WITH ONE LAST BATCH CROSSING OVERHEAD LATER THAT NIGHT WITH THE PASSAGE OF THE 500MB TROUGH AXIS. AT THIS POINT THE ECMWF...IN A SWAP OF POSITIONS WITH THE GFS...STARTS TO AMPLIFY THE REMAINS OF THE LOW JUST TO THE NORTHEAST OF KENTUCKY WHILE THE GFS KEEPS THE CORE OF ITS TROUGH FURTHER NORTH. BY SUNDAY NIGHT...THE TROUGHING WILL STILL BE IN CONTROL OF THE WEATHER OVER EAST KENTUCKY...THOUGH THE ECMWF IS CERTAINLY MORE AMPLIFIED WITH ITS SOUTHERN CLOSED LOW IN CONTRAST TO THE OPEN TROUGH FROM THE GFS CENTERED NORTH OF LAKE EERIE. REGARDLESS...THIS DEVELOPMENT WILL LIKELY KEEP CYCLONIC FLOW OVER THE AREA INTO THE START OF THE NEW WEEK AND ALSO PREVENT MUCH IN THE WAY OF RIDGING FROM MOVING IN FROM THE PLAINS. TO CLOSE OUT THE EXTENDED...THE ECMWF DEPICTS AN OMEGA BLOCK OVER THE UNITED STATES WITH ITS EASTERN LOW CENTERED JUST OFF THE MID ATLANTIC COAST... FURTHER WEST THAN THE GFS VERSION...BUT ALSO STRONG AND BROAD ENOUGH TO STILL DOMINATE THE WX FOR THE JKL CWA. FAVORED A GENERAL MODEL BLEND EARLY IN THE EXTENDED THEN A LEAN TOWARD THE MORE AMPLIFIED AND BLOCKY ECMWF FOR THE LATTER PART...THOUGH PREFERRED A MORE GRADUAL EVOLUTION THAN WHAT IT PORTRAYED THROUGH THE WEEKEND. SENSIBLE WEATHER WILL FEATURE MUCH COOLER AIR MOVING INTO EAST KENTUCKY IN THE WAKE OF A DEPARTING COLD FRONT. AS THE UPPER LOW CYCLES OVERHEAD...A FEW SHOWERS WILL BE POSSIBLE THROUGH THE START OF THE WEEKEND BEFORE DRIER AIR AND A STRENGTHENING AREA OF HIGH PRESSURE WIN OUT AND LIKELY KEEP THE WEATHER QUIET INTO THE START OF THE NEW WORK WEEK. THIS SFC HIGH...AND A LOW SHAPING UP WELL TO THE EAST OF THE AREA...SHOULD SUPPRESS A DEVELOPING WARM FRONT TO THE SOUTH OF THE AREA KEEPING DRY AND SEASONABLY COOL WEATHER GOING THROUGH TUESDAY. THE CR GRID LOAD CAME IN REASONABLE FOR THE BULK OF THE EXTENDED... THOUGH DID MAKE SOME ADJUSTMENTS TOWARD THE LATEST ECMWF SOLUTION LATER ON AND ALSO TO EMPHASIZE MORE OF A DIURNAL COMPONENT TO THE SHOWERS FRIDAY INTO SATURDAY MORNING. DID ALSO FINE TUNE THE LOW TEMPERATURE GRIDS FROM SUNDAY THROUGH TUESDAY MORNING TO BETTER DEPICT RIDGE AND VALLEY DETAILS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 639 AM EDT WED MAY 14 2014 AN APPROACHING COLD FRONT WILL BE THE FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT ACROSS EASTERN KENTUCKY TODAY AND TONIGHT. THUNDERSTORM ACTIVITY MAY BE SLOW TO MOVE INTO THE TAF SITES TODAY...BUT SHOULD EVENTUALLY SPREAD INTO FAR EASTERN KENTUCKY BY LATE IN THE DAY OR THIS EVENING. GOING TO KEEP EVERYTHING VFR INTO TONIGHT...ALTHOUGH WE SHOULD SEE SOME LOWER CIGS AND VISBYS WITH THE THUNDERSTORMS LATE TODAY AND TONIGHT. OF COURSE ANTICIPATING THUNDERSTORM DEVELOPMENT BEYOND 9 TO 12 HOURS IS HARD TO DO...SO WILL REMAIN GENERIC WITH THUNDERSTORM MENTION IN THE TAFS UNTIL WE CAN GET SOME BETTER CONFIDENCE ON WHEN AND WHERE STORMS MAY DEVELOP. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...KAS LONG TERM...GREIF AVIATION...KAS
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
903 AM CDT WED MAY 14 2014 .SOUNDING DISCUSSION... NO PROBLEMS WITH FLIGHT THIS MORNING. CONSIDERABLE RECOVERY OF MOISTURE SINCE 00Z WITH PRECIPITABLE WATER INCREASED TO 1.61 INCHES AND LIFTED INDEX UP FROM A STABLE +3 TO A VERY UNSTABLE -9.6. SHALLOW 2C SURFACE BASED INVERSION TO 1000MB...THEN MOIST ADIABATIC TO ANOTHER 2C INVERSION AT 476MB...THEN PSEUDO TO FIRST TROPOPAUSE AT 182MB WITH A TEMPATURE OF -62.1C. A SECOND TROP WAS DETECTED AT 102MB/-72.5C. MOISTURE PROFILE WAS NEAR SATURATION SURFACE TO 690 MB...THEN A RELATIVELY DRY LAYER TO 470MB...THEN SATURATED TO TROPOPAUSE. WIND PROFILE SHOWS DEEP SE FLOW SURFACE TO 800MB GENERALLY LESS THAN 20KT...S-SW 20-85KT ABOVE. PEAK WIND 246/85KT AT 44.2KFT. BALLOON BURST AT 7.06 MB/20.8 MILES UP NEAR PROGRESS ROAD 1 MILE NE OF THE POPLARVILLE/PEARL RIVER COUNTY AIRPORT. USING CHAP ON THIS MORNING`S SOUNDING LIFTING 347K FROM 950 MB YIELDS AT 80 PERCENT CHANCE OF THUNDERSTORMS TODAY. GUST POTENTIAL 32 KT...PEA HAIL POSSIBLE WITH A 71 VIL. EFFICIENT PRECIPITATION 3.39 INCHES INDICATED WITH POTENTIAL FOR 5.77 INCHES FOR TEMPERATURES BELOW 75F. HEAVY RAIN UNDERWAY IN NEW ORLEANS WHERE TEMPERATURE IS 74F...SO FLOODING RAIN POTENTIAL IS IN PLAY FOR TRAIN ECHO DYNAMICS. 24/RR && .PREV DISCUSSION... /ISSUED 358 AM CDT WED MAY 14 2014/ SYNOPSIS... SURFACE COLD FRONT NEARING NORTHWESTERN ZONES...BUT COOLER AIR STILL LAGGING A BIT BEHIND. ISOLATED SHOWERS BEGINNING TO POP UP OVER COASTAL AREAS OF SE LA AND ALSO OVER GULF WATERS EAST OF THE MS RIVER. TEMPS GENERALLY SITTING IN THE LOWER 70S WITH DEWPOINTS IN THE UPPER 60S AND LOWER 70S. DISCUSSION... COLD FRONT WILL SLOWLY MOVE THROUGH THE LOCAL AREA TODAY AS DEEP UPPER TROUGH SLIDES TOWARD THE MISSISSIPPI VALLEY. PLENTY OF MOISTURE WITH ADDED LIFT ALONG AND AHEAD OF THE FRONT SHOULD LEAD RESULT IN SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE REGION. BEST INSTABILITY AND FORCING LOOK TO BE NORTH AND EAST OF LOCAL AREA...SO RISK OF SEVERE WEATHER IS LOW...BUT A FEW ISOLATED STORMS COULD BECOME SEVERE THIS AFTERNOON WITH THE MAIN THUNDERSTORM THREATS BEING STRONG/DAMAGING WIND GUSTS AND FREQUENT LIGHTNING. RISK WILL BE HIGHEST ACROSS FAR NORTHEASTERN ZONES WHERE SPC CONTINUES TO INDICATE A SLIGHT RISK OF SEVERE WEATHER MAINLY FOR PIKE AND WALTHALL COUNTIES. STILL LOOKS LIKE A BROKEN SQUALL LINE WILL DEVELOP ALONG THE FRONT AT SOME POINT... THOUGH WHETHER THAT HAPPENS OVER THE LOCAL AREA OR EAST OF THE LOCAL AREA IS A BIT UNCERTAIN. BOTH NCEP WRF AND LATEST HRRR RUNS INDICATE SOME POTENTIAL THAT THE LINE WILL BEGIN TO SOLIDIFY OVER EASTERN ZONES...WITH THE NCEP WRF A BIT MORE AGGRESSIVE THAN THE HRRR. SHOULD ALSO MENTION THAT THERE IS AT LEAST SOME POTENTIAL FOR LOCALLY HEAVY RAINFALL ACROSS EASTERN ZONES WHERE PW VALUES ARE FORECAST TO APPROACH 2 INCHES BY THIS AFTERNOON. THESE VALUES ARE SIMILAR TO WHAT WAS SEEN LAST WEEK AND RAINFALL RATES COULD EASILY TOP 2 INCHES PER HOUR IN SOME OF THE HEAVIER STORMS. THAT BEING SAID...WE COULD START TO SEE SOME PONDING ISSUES IN THE USUAL LOW LYING AND POOR DRAINAGE AREAS. RAIN CHANCES GRADUALLY TAPER OFF FROM WEST TO EAST TONIGHT AS THE UPPER TROUGH AXIS FINALLY SLIDES THROUGH THE LOCAL AREA AND STRONG COLD AIR ADVECTION TAKES HOLD OF THE AREA. LOWS TONIGHT FORECAST TO DROP INTO THE UPPER 40S NORTHWEST TO MID 50S SOUTHEAST...WHICH IS ROUGHLY 25 DEGREES LOWER THAN TEMPERATURES WILL BE THIS MORNING. COOL AND DRY HIGH PRESSURE CONTINUES TO BUILD INTO THE AREA DURING THE DAY TOMORROW AND WILL REMAIN IN PLACE FOR A DAY OR TWO...WITH TEMPERATURES REMAINING BELOW NORMAL THROUGH AT LEAST FRIDAY. THE STRONG COLD AIR ADVECTION WILL RESULT IN BREEZY CONDITIONS TONIGHT AND TOMORROW...ESPECIALLY ACROSS AREAS SOUTH OF THE TIDAL LAKES. DOESN/T LOOK LIKE WE/LL MEET WIND ADVISORY CRITERIA AT THIS TIME...BUT IT COULD GET CLOSE RIGHT ALONG THE SOUTH SHORE OF LAKE PONTCHARTRAIN. SHOULD ALSO MENTION THAT STRONG NORTHERLY WINDS OVER LAKE PONTCHARTRAIN COULD PUSH SOME WATER UP ONTO LAKESHORE DRIVE OUTSIDE OF LEVEE PROTECTION. FOR THAT REASON WILL BE ISSUING A COASTAL FLOOD ADVISORY FOR ORLEANS PARISH THAT WILL BE LIKELY BE IN EFFECT FROM 6PM THIS EVENING THROUGH NOON TOMORROW. GOOD NEWS IS THAT THE STRONGEST WINDS WILL COINCIDE WITH LOW TIDE...SO IMPACTS SHOULD BE MINIMAL. SLOW MODERATION OF THE AIR MASS BEGINS ON SATURDAY AS THE SURFACE HIGH SHIFTS EASTWARD AND AN ONSHORE COMPONENT TO THE WIND RETURNS. DESPITE INCREASE IN MOISTURE AND WARMING AFTERNOON TEMPERATURES... AMPLIFIED UPPER LEVEL RIDGING WILL TAKE HOLD OF THE AREA BY MONDAY AND SUBSIDENCE ALOFT SHOULD KEEP A LID ON CONVECTIVE POTENTIAL. SHOULD BE BACK TO WARM AND MUGGY BY MIDWEEK. AVIATION... EXPECT VFR TO MVFR CONDITIONS TO PREVAIL THROUGH THE FORECAST PERIOD. SHOWERS AND THUNDERSTORMS REMAIN VERY ISOLATED OVERNIGHT AND MAINLY ACROSS THE THE WESTERN PORTIONS OF THE FORECAST AREA POSSIBLY AFFECTING KBTR...KMCB AND KMSY. AS A RESULT...WILL MAINTAIN VICINITY SHOWERS THROUGH AT LEAST 15Z. THERE IS A CHANCE FOR SOME LIGHT PATCHY FOG TO DEVELOP NEAR DAYBREAK AT MCB AND HUM. A COLD FRONT WILL MOVE THROUGH THE AREA TODAY AND COVERAGE WILL INCREASE AT 15Z THROUGH 00Z THURSDAY. LOOKS FOR TEMP/PREVAILING TSRA GROUPS DURING THIS TIME AS THE CONVECTION TRACK FROM WEST TO EAST TODAY AND TAPERING AFTER 00Z THURSDAY. MARINE... SOUTHEAST FLOW HAS EASED IN ADVANCE OF A COLD FRONT. THE COLD FRONT WILL LIKELY TRACK ACROSS THE COASTAL WATERS FROM WEST TO EAST THIS AFTERNOON AND EVENING. STRONG OFFSHORE FLOW WILL DEVELOP IN THE WAKE OF THE AFOREMENTIONED COLD FRONT LATE THIS AFTERNOON AND CONTINUE THROUGH THURSDAY. AFTER THE FRONTAL PASSAGE...STRONG COLD AIR ADVECTION WILL CAUSE THICKNESS LAYER 1000-700MB TO DECREASE AROUND 50M OVER UPPER 70S WATER TEMPS. AS A RESULT...BOUNDARY LAYER WINDS OF 20 TO 25 KNOTS WILL MIXED DOWN TO THE WARM SEA SURFACE LATE THIS AFTERNOON THROUGH THURSDAY EVENING. THEREFORE...A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR ALL COASTAL WATERS 6PM TODAY THROUGH 6PM THURSDAY. THE WINDS WILL GRADUALLY DIMINISH ON FRIDAY. DECISION SUPPORT... DSS CODE...BLUE. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...SLURRY SUPPORT MONITORING RIVER FLOODING 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 TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 75 47 71 45 / 70 20 10 0 BTR 75 50 74 49 / 60 20 10 0 ASD 80 52 73 49 / 60 30 10 0 MSY 80 56 73 56 / 60 20 10 0 GPT 80 54 74 51 / 70 30 10 0 PQL 82 55 74 46 / 70 40 10 0 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...COASTAL FLOOD ADVISORY FROM 6 PM WEDNESDAY TO NOON THURSDAY FOR THE FOLLOWING ZONES: AND ORLEANS. GM...SMALL CRAFT ADVISORY FROM 6 PM WEDNESDAY TO 6 PM THURSDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND MISSISSIPPI SOUND. MS...NONE. GM...SMALL CRAFT ADVISORY FROM 6 PM WEDNESDAY TO 6 PM THURSDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND MISSISSIPPI SOUND. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1039 AM EDT WED MAY 14 2014 .SYNOPSIS... HIGH PRESSURE WILL SLIDE EAST TODAY AND RETURN FLOW SETS UP OVER THE AREA. AN UNSETTLED WEATHER PATTERN WILL BE IN PLACE THURSDAY THROUGH EARLY NEXT WEEK AS A SLOW-MOVING COLD FRONT APPROACHES OVER THE WEEKEND...THEN LOW PRESSURE DEVELOPS ALONG IT NEARBY AND LINGERS INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 1030 AM UPDATE...A FEW MINOR ADJUSTMENTS TO THE FORECAST BASED ON LATEST TRENDS IN OBSERVATIONAL DATA. MOST OF THE AREA WILL REMAIN DRY TODAY EXCEPT FOR A FEW SHOWERS IN THE NORTH AND EASTERN ZONES. OTHERWISE...CLOUDS WILL PREVAIL WITH BREAKS OF SUN AT TIMES. HIGHS SHOULD GET INTO THE 70S WELL INLAND...WITH 50S ALONG THE COAST. PREVIOUSLY... UPDATE...A FEW MINOR ADJUSTMENTS TO POP BASED ON LATEST RADAR TRENDS. WAA SHRA ARE SLIDING EWD TOWARDS CENTRAL ME. REMNANTS OF NY STATE CONVECTION ARE ALSO DISSIPATING ACROSS WRN NH. GRADUALLY WE SHOULD WORK TOWARDS DRY WX FOR MOST OF THE AREA THIS AFTERNOON. PREVIOUS DISCUSSION...CONVECTIVE COMPLEX OVER NY STATE IS SLOWLY SAGGING S AND DRYING UP AS IT MOVES EWD. THIS TREND SUPPORTS HI- RES MODEL SOLUTIONS LIKE THE HRRR/RAP. HOWEVER A WING OF WAA WILL BRUSH THE CWFA THIS MORNING...AS UPPER RIDGE AXIS SLIDES EWD. THESE SHRA ARE ELEVATED IN NATURE AND THERE REMAINS SOME LINGERING DRY AIR AT THE SFC ESPECIALLY ACROSS WRN ME. WILL LEAVE ANY MENTION OF PCPN AT SCT OR ISOLD ATTM. AS RETURN FLOW SETS UP TODAY BROAD WAA WILL SUPPORT A MIX OF SUN AND CLOUDS. TEMPS WILL MODERATE SOME THOUGH...ESPECIALLY ACROSS NH. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... FOCUS TONIGHT WILL BE ON DEVELOPING MARINE FOG/STRATUS. MESOSCALE MODELS AND MOS GUIDANCE BOTH SUGGEST IT WILL OCCUR. ATTM IR SATELLITE SHOWS A LARGE AREA OF STRATUS OVER THE MID ATLANTIC...SLOWLY EXPANDING NWD. LATEST HRRR HAS A VERY GOOD HANDLE ON THIS AREA AND CLOUD HEIGHTS WITHIN IT. IN THE NEXT SEVERAL HOURS IT DEVELOPS STRATUS IN THE GULF OF ME. ATTM STRATUS IS ABSENT HERE ON SATELLITE IMAGERY. FEEL THAT IT MAY BE SLIGHTLY OVERAGGRESSIVE DUE TO THE COLD WATER TEMPS IN THE GULF. HOWEVER DURING THE DAY AS WINDS TURN MUCH MORE SLY OVER A LONGER FETCH TO OUR S THIS AREA OF FOG/STRATUS SHOULD DEVELOP QUICKLY. CURRENT FORECAST IS FOR THIS AREA TO MOVE ONSHORE BY OR SHORTLY AFTER 00Z. SOME SHALLOW LIFT COUPLED WITH DRY AIR ALOFT WILL LIKELY LEAD TO SOME DZ THROUGHOUT THE NIGHT AS WELL. DIURNAL HEATING AND INCREASING SLY WINDS SHOULD HELP TO PARTIALLY MIX OUT THE STRATUS DURING THE DAY THU. THIS HEATING COULD ALSO LEAD TO SCT AFTERNOON SHRA. ON THE NRN AND WRN FRINGES OF THE MARINE LAYER MARGINAL LAPSE RATES WILL BE PRESENT ALOFT. NAM BUFKIT SOUNDINGS YIELD CAPE AOA 500 J/KG FOR THESE AREAS...SO WILL MAINTAIN SOME MENTION OF THUNDER DURING THE DAY THU. && .LONG TERM /FRIDAY THROUGH TUESDAY/... A SLOW MOVING FRONTAL BOUNDARY WILL APPROACH NEW ENGLAND THURSDAY NIGHT FROM THE WEST. WAVES OF LOW PRESSURE ALONG THIS FRONT WILL SLOW THE PROGRESS OF THIS SYSTEM AS IT BUMPS INTO THE UPPER LEVEL RIDGE WITH TIME. AHEAD OF THE PRECIPITATION...EXPECT WARM AND MUGGY CONDITIONS ON FRIDAY AWAY FROM THE COAST. ALONG THE SHORELINE...IT WILL BE A COOLER DUE TO AN ONSHORE FLOW. PATCHY DRIZZLE AND FOG IS LIKELY AS WELL...MAINLY DURING THE MORNING AND EVENING HOURS. 00Z MODEL SUITE HAS SOME DISAGREEMENT ON THE TIMING OF THE BAND OF PRECIPITATION ASSOCIATED WITH THE SLOW MOVING COLD FRONT. THE EURO IS THE FASTEST WITH THIS PRECIPITATION...WHILE THE GFS HOLDS MOISTURE TO THE WEST...KEEPING MUCH OF OUR FORECAST AREA DRY FRIDAY NIGHT...WITH THE EXCEPTION OF SOUTHWEST NEW HAMPSHIRE. WILL ALLOW FOR A COMPROMISE IN TERMS OF THE TIMING OF THE PRECIP. SHOWERS MAY BE LOCALLY HEAVY SATURDAY MORNING...MAINLY OVER NEW HAMPSHIRE AS DEEP LAYERED MOISTURE ENTERS THE REGION FROM WELL OFF THE EASTERN SEABOARD. A WEAK AREA OF LOW PRESSURE SLOWLY DEVELOPS ALONG THIS FRONT OFF THE NEW ENGLAND COASTLINE LATE IN THE WEEKEND AND EARLY NEXT WEEK. THIS WILL ALLOW A PERSISTENT COOL AND MOIST MARITIME FLOW OVER THE REGION WITH AT LEAST SCATTERED SHOWERS ON A DAILY BASIS. PREFER THE GFS SOLUTION WITH QPF THROUGH THIS EXTENDED TIME RANGE...BRINGING UP TO THREE INCHES OF RAIN FOR THE FOOTHILLS OF MAINE AND THE HIGHER TERRAIN OVER CENTRAL/NORTHERN NEW HAMPSHIRE. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM...VFR CONDITIONS GENERALLY EXPECTED TODAY. WILL HAVE TO WATCH FOR BKN MVFR DECK OF CLOUDS TO DEVELOP WITH DIURNAL HEATING...AS SUGGESTED BY SOME SHORT TERM GUIDANCE. THEN FOCUS TURNS TO MARINE FOG/STRATUS AS WARM...MOIST AIR RETURNS NWD. MESOSCALE MODELS ARE IN AGREEMENT THAT IT WILL FORM AROUND OR SHORTLY AFTER 00Z THIS EVENING. EXPECTED WIDESPREAD IFR OR LOWER FOR COASTAL TERMINALS. LONG TERM...IFR OR LOWER CONDITIONS EXPECTED AGAIN THU NIGHT IN MARINE FOG/STRATUS. SOME IMPROVEMENT DURING THE DAY FRI BEFORE COLD FNT APPROACHES WILL DETERIORATING CIGS/VSBYS AND POSSIBLE HEAVY RNFL INTO SAT. && .MARINE... SHORT TERM...DEEP SLY FLOW EXPECTED TO DEVELOP TODAY AS HIGH PRES SHIFTS E OF THE WATERS. LATE THU SEAS ON THE OUTER WATERS WILL BEGIN TO BUILD TOWARDS 5 FT. EXPECT VSBY RESTRICTIONS IN FOG BEGINNING TONIGHT. LONG TERM...WINDS GENERALLY EXPECTED TO REMAIN BELOW SCA THRESHOLDS...THOUGH SUSTAINED SLY FLOW WILL BRING SEAS ABOVE 5 FT FOR AN EXTENDED PERIOD THROUGH THE WEEKEND. && .FIRE WEATHER... DEEP SOUTHERLY FLOW DEVELOPING TODAY WILL KEEP MOISTURE ON THE RISE THROUGH THE WEEKEND. DESPITE WARMING TEMPERATURES...RISING MOISTURE WILL ALSO KEEP RELATIVE HUMIDITY VALUES IN THE MODERATE RANGE DURING THE DAY AND HIGH AT NIGHT. THE BEST CHANCE FOR WETTING RAINS WILL BE LATE FRIDAY INTO SATURDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
953 AM EDT WED MAY 14 2014 .SYNOPSIS... HIGH PRESSURE WILL MOVE EAST OF THE REGION TODAY AS A WARM FRONT LIFTS NORTHWARD ACROSS THE REGION. LOW PRESSURE AND A COLD FRONT WILL MOVE VERY SLOWLY TOWARD REGION FROM THE QUEBEC PROVINCE LATE IN THE WEEK WHILE HIGH PRESSURE HOLDS ACROSS THE WESTERN ATLANTIC. && .NEAR TERM /THROUGH TONIGHT/... UPDATE...DECREASED POPS FOR TODAY AS SCATTERED SHOWERS SEEMS TO CAPTURE THE THREAT BEST. TEMPERATURES WILL WARM TO THE UPPER 50S TO NEAR 60F LATER THIS AFTERNOON AFTER THE WARM FRONT CROSSES. TEMPERATURES WILL NOT FALL MUCH TONIGHT WITH WARM AND MOIST AIR ADVECTING INTO THE AREA. THIS WILL CAUSE AREAS OF DRIZZLE AND FOG LATER TONIGHT INTO EARLY THURSDAY MORNING...MOSTLY FOR THE COAST AND UPSLOPE AREAS IN SOUTHERN PISCATAQUIS AND NORTHERN PENOBSCOT. LOW MORNING CLOUDS WILL GIVE WAY TO SOME SUNSHINE AND THE WARMEST DAY OF THE YEAR FOR MOST LOCATIONS. TEMPERATURES WILL REACH THE 70S INLAND WITH UPPER 70S IN THE ALLAGASH. THE COAST WILL BE MUCH COOLER WITH AN ONSHORE FLOW AND HIGHS IN THE LOW 60S. PREVIOUS DISCUSSION LATEST RADAR SHOWED A BAND OF SHOWERS IN ASSOCIATION WITH THE APPROACHING 850 MB WARM FRONT WORKING EAST FROM QUEBEC. LATEST MESOSCALE GUIDANCE INCLUDING THE HRRR AND RAP SHOW THIS BAND WILL MOVE NORTHEAST ACROSS THE REGION THIS MORNING. THE BEST CHANCE FOR SHOWERS WILL BE ACROSS NORTHERN AREAS THIS MORNING WITH LESSER CHANCES DOWNEAST. THIS BAND OF SHOWERS WILL MOVE EAST INTO NEW BRUNSWICK BY LATE MORNING OR EARLY AFTERNOON WITH MOSTLY CLOUDY/PARTLY SUNNY SKIES IN ITS WAKE. HIGHS TODAY WILL BE DEPENDENT ON HOW MUCH SUN WE SEE LATER TODAY. THE BEST CHANCES WILL BE BACK ACROSS WESTERN AREAS LATER THIS AFTERNOON AND THIS MAY ALLOW TEMPERATURES TO RISE WELL INTO THE 60S. IT WILL BE COOLER ACROSS DOWNEAST MAINE ESPECIALLY THE IMMEDIATE COAST WHERE A COOLER ONSHORE FLOW WILL KEEP TEMPERATURES ONLY IN THE LOW TO MID 50S. THE 500MB RIDGE AXIS WILL MOVE EAST OF THE REGION TONIGHT. SOUTH WINDS AROUND THE HIGH TO OUR EAST WILL BRING THE POTENTIAL FOR LOW CLOUDS AND FOG ESPECIALLY ACROSS DOWNEAST MAINE. BUFKIT SOUNDINGS CERTAINLY APPEAR FAVORABLE FOR LOW STRATUS DEVELOPMENT DOWNEAST LATER TONIGHT. OTHER THAN SOME PATCHY LIGHT DRIZZLE DOWNEAST IT SHOULD REMAIN DRY TONIGHT. LOWS TONIGHT WILL BE MAINLY IN THE MID TO UPPER 40S WITH UPPER 40S TO LOW 50S DOWNEAST. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... HIGH AMPLITUDE UPPER RIDGE OVR THE WRN ATLC/ERN US/ERN CAN W/ DIGGING UPPER TROF ACROSS THE WRN GRT LAKES AND MISSISSIPPI RVR VLY AT THE START OF THE SHORT TERM PD THU AM... AT THE SFC...LOW PRES OVR THE WRN OH VLY/SRN GRT LAKES REGION W/ BROAD SRLY FLOW ACROSS OUR REGION W/ SFC HIGH PRES JUST E OF OUR AREA. STRONG UPPER RIDGE ACROSS THE REGION WILL KEEP SYSTEM TO OUR W INITIALLY AT BAY W/ DRY BUT MILD BUT RATHER HUMID CONDS ACROSS OUR REGION THRU FRI. TEMPS WILL BE ON THE TRICKY SIDE AS OVERALL UPPER HGTS AND SFC-1000 THICKNESS SUGGESTS TEMPS QUITE WARM DURING THIS PD BUT SRLY FLOW OFF THE COLD ATLC WATERS WILL LIKELY HAVE SOME MODERATING INFLUENCES ON OVERALL TEMPS SO HAVE GONE CONSERVATIVE FOR NOW. FOG MAY ALSO BE AN ISSUE SPCLY ACROSS SRN AREAS W/ THE WARM AND HUMID SRLY FLOW OFF THE COLD ATLC WATERS... OVERALL HOWEVER...A VERY SPRING-LIKE PTRN THU/FRI W/ NO MAJOR ISSUES EXPECTED. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE STRONG UPPER RIDGE WHICH PROTECTED OUR REGION THRU FRI W/ DRY AND MILD CONDS WILL GRADUALLY SHIFT EWRD ALLOWING THE WX SYSTEM W OF THE AREA TO GRADUALLY BECOME MORE OF A FACTOR FOR OUR AREA... ATTM...THE LONGER RANGE MODEL GUIDANCE PLACES A SLOW MOVG FRONTAL SYSTEM ACROSS WRN NEW ENGLAND BY ERLY SAT AM W/ PRECIP BEGINNING TO OVERSPREAD OUR WRN AREAS. THIS FRONTAL BNDRY CONTS TO SLOWLY PUSH EWRD THEN STALL OVR THE AREA AS THE UPPER SUPPORTING TROF IS FCST TO CUTOFF WELL S OF THE AREA W/ A RATHER MOIST AND UNSETTLED ENERLY FLOW TO DVLP ACROSS OUR AREA AND PERSIST THRU THE REMAINDER OF LONG TERM PD. MAIN UNCERTAINTY DURING THIS PD WILL BE THE EXTEND THAT THE CUTOFF TO OUR S WILL BE ABLE TO KEEP DEEPER MOISTURE ACROSS OUR AREA. PLACEMENT MAY BE FAR ENUF S THAT ONLY OCNL SHOWERS DOMINATE THE WX PTRN AND ANY FURTHER SRN SHIFT COULD RENDER SPCLY NRN AREAS MAINLY DRY. GIVEN THESE UNCERTAINTIES...WILL CARRY MOSTLY JUST CHC POPS THRU THE PD. TEMPS WILL START A LITTLE ABV SEASONAL NORMS AND THEN COOL TO NR OR JUST SLIGHTLY BLO SEASONAL NORMS DEPENDING ON CLD CVR AND PRECIP. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... NEAR TERM: VFR CONDITIONS EARLY THIS MORNING WILL GIVE WAY TO SOME MVFR CONDITIONS IN SHOWERS ACROSS NORTHERN AREAS THIS MORNING. VFR/MVFR BKN-OVC CIGS ARE POSSIBLE THIS AFTERNOON. MVFR/IFR IS EXPECTED TO DEVELOP LATE TONIGHT DEVELOPING LOW CLOUDS AND PATCHY FOG ESPECIALLY KBGR/KBHB WHERE LIFR CONDITIONS ARE POSSIBLE AFTER 06Z. SHORT TERM: A WARM AND INCREASINGLY HUMID SRLY FLOW WILL LEAD TO INCREASING CHCS FOR FOG SPCLY SRN AREAS DURING THE OVRNGT/ERLY AM HRS W/ THESE CONDS LIKELY INTO SUN. OTHERWISE VFR CONDS ARE ANTICIPATED. && .MARINE... NEAR TERM: WIND/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH TONIGHT. VISIBILITY WILL BE REDUCED TO 1 TO 3 NM IN AREAS OF FOG LATE TONIGHT. SHORT TERM: WNDS/SEAS EXPECTED TO REMAIN BLO SCA LEVELS THRU THE PD THO SEAS MAY APPROACH 5 FT LATE IN THE PD IN PERSISTENT SRLY FLOW. ALSO EXPECT FOG TO BECOME RATHER PREVALENT W/ THE WARM AND HUMID SRLY FLOW OVR THE COLD ATLC WATERS... && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...DUDA/MCW SHORT TERM...KHW LONG TERM...KHW AVIATION...DUDA/MCW/KHW MARINE...DUDA/MCW/KHW
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
725 AM EDT WED MAY 14 2014 .SYNOPSIS... HIGH PRESSURE WILL SLIDE EAST TODAY AND RETURN FLOW SETS UP OVER THE AREA. AN UNSETTLED WEATHER PATTERN WILL BE IN PLACE THURSDAY THROUGH EARLY NEXT WEEK AS A SLOW-MOVING COLD FRONT APPROACHES OVER THE WEEKEND...THEN LOW PRESSURE DEVELOPS ALONG IT NEARBY AND LINGERS INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... UPDATE...A FEW MINOR ADJUSTMENTS TO POP BASED ON LATEST RADAR TRENDS. WAA SHRA ARE SLIDING EWD TOWARDS CENTRAL ME. REMNANTS OF NY STATE CONVECTION ARE ALSO DISSIPATING ACROSS WRN NH. GRADUALLY WE SHOULD WORK TOWARDS DRY WX FOR MOST OF THE AREA THIS AFTERNOON. PREVIOUS DISCUSSION...CONVECTIVE COMPLEX OVER NY STATE IS SLOWLY SAGGING S AND DRYING UP AS IT MOVES EWD. THIS TREND SUPPORTS HI- RES MODEL SOLUTIONS LIKE THE HRRR/RAP. HOWEVER A WING OF WAA WILL BRUSH THE CWFA THIS MORNING...AS UPPER RIDGE AXIS SLIDES EWD. THESE SHRA ARE ELEVATED IN NATURE AND THERE REMAINS SOME LINGERING DRY AIR AT THE SFC ESPECIALLY ACROSS WRN ME. WILL LEAVE ANY MENTION OF PCPN AT SCT OR ISOLD ATTM. AS RETURN FLOW SETS UP TODAY BROAD WAA WILL SUPPORT A MIX OF SUN AND CLOUDS. TEMPS WILL MODERATE SOME THOUGH...ESPECIALLY ACROSS NH. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... FOCUS TONIGHT WILL BE ON DEVELOPING MARINE FOG/STRATUS. MESOSCALE MODELS AND MOS GUIDANCE BOTH SUGGEST IT WILL OCCUR. ATTM IR SATELLITE SHOWS A LARGE AREA OF STRATUS OVER THE MID ATLANTIC...SLOWLY EXPANDING NWD. LATEST HRRR HAS A VERY GOOD HANDLE ON THIS AREA AND CLOUD HEIGHTS WITHIN IT. IN THE NEXT SEVERAL HOURS IT DEVELOPS STRATUS IN THE GULF OF ME. ATTM STRATUS IS ABSENT HERE ON SATELLITE IMAGERY. FEEL THAT IT MAY BE SLIGHTLY OVERAGGRESSIVE DUE TO THE COLD WATER TEMPS IN THE GULF. HOWEVER DURING THE DAY AS WINDS TURN MUCH MORE SLY OVER A LONGER FETCH TO OUR S THIS AREA OF FOG/STRATUS SHOULD DEVELOP QUICKLY. CURRENT FORECAST IS FOR THIS AREA TO MOVE ONSHORE BY OR SHORTLY AFTER 00Z. SOME SHALLOW LIFT COUPLED WITH DRY AIR ALOFT WILL LIKELY LEAD TO SOME DZ THROUGHOUT THE NIGHT AS WELL. DIURNAL HEATING AND INCREASING SLY WINDS SHOULD HELP TO PARTIALLY MIX OUT THE STRATUS DURING THE DAY THU. THIS HEATING COULD ALSO LEAD TO SCT AFTERNOON SHRA. ON THE NRN AND WRN FRINGES OF THE MARINE LAYER MARGINAL LAPSE RATES WILL BE PRESENT ALOFT. NAM BUFKIT SOUNDINGS YIELD CAPE AOA 500 J/KG FOR THESE AREAS...SO WILL MAINTAIN SOME MENTION OF THUNDER DURING THE DAY THU. && .LONG TERM /FRIDAY THROUGH TUESDAY/... A SLOW MOVING FRONTAL BOUNDARY WILL APPROACH NEW ENGLAND THURSDAY NIGHT FROM THE WEST. WAVES OF LOW PRESSURE ALONG THIS FRONT WILL SLOW THE PROGRESS OF THIS SYSTEM AS IT BUMPS INTO THE UPPER LEVEL RIDGE WITH TIME. AHEAD OF THE PRECIPITATION...EXPECT WARM AND MUGGY CONDITIONS ON FRIDAY AWAY FROM THE COAST. ALONG THE SHORELINE...IT WILL BE A COOLER DUE TO AN ONSHORE FLOW. PATCHY DRIZZLE AND FOG IS LIKELY AS WELL...MAINLY DURING THE MORNING AND EVENING HOURS. 00Z MODEL SUITE HAS SOME DISAGREEMENT ON THE TIMING OF THE BAND OF PRECIPITATION ASSOCIATED WITH THE SLOW MOVING COLD FRONT. THE EURO IS THE FASTEST WITH THIS PRECIPITATION...WHILE THE GFS HOLDS MOISTURE TO THE WEST...KEEPING MUCH OF OUR FORECAST AREA DRY FRIDAY NIGHT...WITH THE EXCEPTION OF SOUTHWEST NEW HAMPSHIRE. WILL ALLOW FOR A COMPROMISE IN TERMS OF THE TIMING OF THE PRECIP. SHOWERS MAY BE LOCALLY HEAVY SATURDAY MORNING...MAINLY OVER NEW HAMPSHIRE AS DEEP LAYERED MOISTURE ENTERS THE REGION FROM WELL OFF THE EASTERN SEABOARD. A WEAK AREA OF LOW PRESSURE SLOWLY DEVELOPS ALONG THIS FRONT OFF THE NEW ENGLAND COASTLINE LATE IN THE WEEKEND AND EARLY NEXT WEEK. THIS WILL ALLOW A PERSISTENT COOL AND MOIST MARITIME FLOW OVER THE REGION WITH AT LEAST SCATTERED SHOWERS ON A DAILY BASIS. PREFER THE GFS SOLUTION WITH QPF THROUGH THIS EXTENDED TIME RANGE...BRINGING UP TO THREE INCHES OF RAIN FOR THE FOOTHILLS OF MAINE AND THE HIGHER TERRAIN OVER CENTRAL/NORTHERN NEW HAMPSHIRE. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM...VFR CONDITIONS GENERALLY EXPECTED TODAY. WILL HAVE TO WATCH FOR BKN MVFR DECK OF CLOUDS TO DEVELOP WITH DIURNAL HEATING...AS SUGGESTED BY SOME SHORT TERM GUIDANCE. THEN FOCUS TURNS TO MARINE FOG/STRATUS AS WARM...MOIST AIR RETURNS NWD. MESOSCALE MODELS ARE IN AGREEMENT THAT IT WILL FORM AROUND OR SHORTLY AFTER 00Z THIS EVENING. EXPECTED WIDESPREAD IFR OR LOWER FOR COASTAL TERMINALS. LONG TERM...IFR OR LOWER CONDITIONS EXPECTED AGAIN THU NIGHT IN MARINE FOG/STRATUS. SOME IMPROVEMENT DURING THE DAY FRI BEFORE COLD FNT APPROACHES WILL DETERIORATING CIGS/VSBYS AND POSSIBLE HEAVY RNFL INTO SAT. && .MARINE... SHORT TERM...DEEP SLY FLOW EXPECTED TO DEVELOP TODAY AS HIGH PRES SHIFTS E OF THE WATERS. LATE THU SEAS ON THE OUTER WATERS WILL BEGIN TO BUILD TOWARDS 5 FT. EXPECT VSBY RESTRICTIONS IN FOG BEGINNING TONIGHT. LONG TERM...WINDS GENERALLY EXPECTED TO REMAIN BELOW SCA THRESHOLDS...THOUGH SUSTAINED SLY FLOW WILL BRING SEAS ABOVE 5 FT FOR AN EXTENDED PERIOD THROUGH THE WEEKEND. && .FIRE WEATHER... DEEP SOUTHERLY FLOW DEVELOPING TODAY WILL KEEP MOISTURE ON THE RISE THROUGH THE WEEKEND. DESPITE WARMING TEMPERATURES...RISING MOISTURE WILL ALSO KEEP RELATIVE HUMIDITY VALUES IN THE MODERATE RANGE DURING THE DAY AND HIGH AT NIGHT. THE BEST CHANCE FOR WETTING RAINS WILL BE LATE FRIDAY INTO SATURDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ NEAR TERM...LEGRO
AREA FORECAST DISCUSSION
NWS CARIBOU ME
612 AM EDT WED MAY 14 2014 .SYNOPSIS... HIGH PRESSURE WILL MOVE EAST OF THE REGION TODAY AS A WARM FRONT LIFTS NORTHWARD ACROSS THE REGION. LOW PRESSURE AND A COLD FRONT WILL MOVE VERY SLOWLY TOWARD REGION FROM THE QUEBEC PROVINCE LATE IN THE WEEK WHILE HIGH PRESSURE HOLDS ACROSS THE WESTERN ATLANTIC. && .NEAR TERM /THROUGH TONIGHT/... UPDATE...INCREASED THE CHANCE FOR SHOWERS THIS MORNING BASED ON LATEST RADAR REFLECTIVITY. LATEST HRRR STILL INDICATED THAT MOST OF THE SHOWER ACTIVITY SHOULD MOVE EAST OF THE AREA BY MIDDAY. NO OTHER SIGNIFICANT CHANGES AT THIS TIME. PREVIOUS DISCUSSION LATEST RADAR SHOWED A BAND OF SHOWERS IN ASSOCIATION WITH THE APPROACHING 850 MB WARM FRONT WORKING EAST FROM QUEBEC. LATEST MESOSCALE GUIDANCE INCLUDING THE HRRR AND RAP SHOW THIS BAND WILL MOVE NORTHEAST ACROSS THE REGION THIS MORNING. THE BEST CHANCE FOR SHOWERS WILL BE ACROSS NORTHERN AREAS THIS MORNING WITH LESSER CHANCES DOWNEAST. THIS BAND OF SHOWERS WILL MOVE EAST INTO NEW BRUNSWICK BY LATE MORNING OR EARLY AFTERNOON WITH MOSTLY CLOUDY/PARTLY SUNNY SKIES IN ITS WAKE. HIGHS TODAY WILL BE DEPENDANT ON HOW MUCH SUN WE SEE LATER TODAY. THE BEST CHANCES WILL BE BACK ACROSS WESTERN AREAS LATER THIS AFTERNOON AND THIS MAY ALLOW TEMPERATURES TO RISE WELL INTO THE 60S. IT WILL BE COOLER ACROSS DOWNEAST MAINE ESPECIALLY THE IMMEDIATE COAST WHERE A COOLER ONSHORE FLOW WILL KEEP TEMPERATURES ONLY IN THE LOW TO MID 50S. THE 500MB RIDGE AXIS WILL MOVE EAST OF THE REGION TONIGHT. SOUTH WINDS AROUND THE HIGH TO OUR EAST WILL BRING THE POTENTIAL FOR LOW CLOUDS AND FOG ESPECIALLY ACROSS DOWNEAST MAINE. BUFKIT SOUNDINGS CERTAINLY APPEAR FAVORABLE FOR LOW STRATUS DEVELOPMENT DOWNEAST LATER TONIGHT. OTHER THAN SOME PATCHY LIGHT DRIZZLE DOWNEAST IT SHOULD REMAIN DRY TONIGHT. LOWS TONIGHT WILL BE MAINLY IN THE MID TO UPPER 40S WITH UPPER 40S TO LOW 50S DOWNEAST. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... HIGH AMPLITUDE UPPER RIDGE OVR THE WRN ATLC/ERN US/ERN CAN W/ DIGGING UPPER TROF ACROSS THE WRN GRT LAKES AND MISSISSIPPI RVR VLY AT THE START OF THE SHORT TERM PD THU AM... AT THE SFC...LOW PRES OVR THE WRN OH VLY/SRN GRT LAKES REGION W/ BROAD SRLY FLOW ACROSS OUR REGION W/ SFC HIGH PRES JUST E OF OUR AREA. STRONG UPPER RIDGE ACROSS THE REGION WILL KEEP SYSTEM TO OUR W INITIALLY AT BAY W/ DRY BUT MILD BUT RATHER HUMID CONDS ACROSS OUR REGION THRU FRI. TEMPS WILL BE ON THE TRICKY SIDE AS OVERALL UPPER HGTS AND SFC-1000 THICKNESS SUGGESTS TEMPS QUITE WARM DURING THIS PD BUT SRLY FLOW OFF THE COLD ATLC WATERS WILL LIKELY HAVE SOME MODERATING INFLUENCES ON OVERALL TEMPS SO HAVE GONE CONSERVATIVE FOR NOW. FOG MAY ALSO BE AN ISSUE SPCLY ACROSS SRN AREAS W/ THE WARM AND HUMID SRLY FLOW OFF THE COLD ATLC WATERS... OVERALL HOWEVER...A VERY SPRING-LIKE PTRN THU/FRI W/ NO MAJOR ISSUES EXPECTED. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE STRONG UPPER RIDGE WHICH PROTECTED OUR REGION THRU FRI W/ DRY AND MILD CONDS WILL GRADUALLY SHIFT EWRD ALLOWING THE WX SYSTEM W OF THE AREA TO GRADUALLY BECOME MORE OF A FACTOR FOR OUR AREA... ATTM...THE LONGER RANGE MODEL GUIDANCE PLACES A SLOW MOVG FRONTAL SYSTEM ACROSS WRN NEW ENGLAND BY ERLY SAT AM W/ PRECIP BEGINNING TO OVERSPREAD OUR WRN AREAS. THIS FRONTAL BNDRY CONTS TO SLOWLY PUSH EWRD THEN STALL OVR THE AREA AS THE UPPER SUPPORTING TROF IS FCST TO CUTOFF WELL S OF THE AREA W/ A RATHER MOIST AND UNSETTLED ENERLY FLOW TO DVLP ACROSS OUR AREA AND PERSIST THRU THE REMAINDER OF LONG TERM PD. MAIN UNCERTAINTY DURING THIS PD WILL BE THE EXTEND THAT THE CUTOFF TO OUR S WILL BE ABLE TO KEEP DEEPER MOISTURE ACROSS OUR AREA. PLACEMENT MAY BE FAR ENUF S THAT ONLY OCNL SHOWERS DOMINATE THE WX PTRN AND ANY FURTHER SRN SHIFT COULD RENDER SPCLY NRN AREAS MAINLY DRY. GIVEN THESE UNCERTAINTIES...WILL CARRY MOSTLY JUST CHC POPS THRU THE PD. TEMPS WILL START A LITTLE ABV SEASONAL NORMS AND THEN COOL TO NR OR JUST SLIGHTLY BLO SEASONAL NORMS DEPENDING ON CLD CVR AND PRECIP. && .AVIATION /10Z WEDNESDAY THROUGH SUNDAY/... NEAR TERM: VFR CONDITIONS EARLY THIS MORNING WILL GIVE WAY TO SOME MVFR CONDITIONS IN SHOWERS ACROSS NORTHERN AREAS THIS MORNING. VFR/MVFR BKN-OVC CIGS ARE POSSIBLE THIS AFTERNOON. MVFR/IFR IS EXPECTED TO DEVELOP LATE TONIGHT DEVELOPING LOW CLOUDS AND PATCHY FOG ESPECIALLY KBGR/KBHB WHERE LIFR CONDITIONS ARE POSSIBLE AFTER 06Z. SHORT TERM: A WARM AND INCREASINGLY HUMID SRLY FLOW WILL LEAD TO INCREASING CHCS FOR FOG SPCLY SRN AREAS DURING THE OVRNGT/ERLY AM HRS W/ THESE CONDS LIKELY INTO SUN. OTHERWISE VFR CONDS ARE ANTICIPATED. && .MARINE... NEAR TERM: WIND/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH TONIGHT. VISIBILITY WILL BE REDUCED TO 1 TO 3 NM IN AREAS OF FOG LATE TONIGHT. SHORT TERM: WNDS/SEAS EXPECTED TO REMAIN BLO SCA LEVELS THRU THE PD THO SEAS MAY APPROACH 5 FT LATE IN THE PD IN PERSISTENT SRLY FLOW. ALSO EXPECT FOG TO BECOME RATHER PREVALENT W/ THE WARM AND HUMID SRLY FLOW OVR THE COLD ATLC WATERS... && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...DUDA SHORT TERM...KHW LONG TERM...KHW AVIATION...DUDA/KHW MARINE...DUDA/KHW
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1006 AM EDT WED MAY 14 2014 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OFFSHORE THROUGH THE REST OF THE WEEK. A COLD FRONT EXTENDING FROM THE GREAT LAKES TO THE GULF COAST STATES WILL TRACK SLOWLY EAST...MOVING INTO THE MID ATLANTIC STATES THURSDAY AND FRIDAY. HIGH PRESSURE IS EXPECTED TO RETURN TO THE MID ATLANTIC THIS WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... EASTERLY FLOW HAS MOVED INTO THE MID ATLANTIC RESULTING IN A 2.5K FT STRATUS DECK ON THE COLD SIDE OF A BACK DOOR COLD FRONT THIS MORNING. A BINARY RESULT OF SKY COVER HAS OCCURRED ACROSS THE REGION DUE TO THE MARINE LAYER. LOCATIONS IN THE CENTRAL FOOTHILLS...ALONG RIDGE LINES AND PARTS OF THE POTOMAC HIGHLANDS ARE GETTING FULL SUN THIS MORNING. WEAK FLOW WITHIN THE MARINE LAYER AS WELL AS ON TOP OF THE MARINE LAYER WILL LEAD TO A SLOW DISSIPATION FROM WEST TO EAST OF STRATUS TODAY. THIS WILL LEAD TO TEMPS REACHING THE LOW 70S IN NE MD TO THE UPPER 70S IN NOVA AND THE PANHANDLE OF WV. FCST SOUNDINGS THAT HAD A HANDLE ON THE MARINE LAYER FROM THE 12Z IAD RAOB SHOWS THE POTENTIAL FOR BREAKS IN THE CLOUDS THIS AFTERNOON WITH NE MD INCLUDING BALTIMORE METRO BEING THE LAST TO BREAK BY LATE AFTERNOON. OVERALL...NOT EXPECTING STRATUS DECK TO ERODE DURING THE DAY FOR AREAS EAST OF THE BLUE RIDGE INCLUDING THE I-95 CORRIDOR AND PIEDMONT. ELSEWHERE...FULL SUN WILL LEAD TO TEMPS REACHING THE 80S TODAY AND PER THE 12Z RNK RAOB WHICH IS UPSTREAM... INSTABILITY OF UP TO 2000 J/KG IS POSSIBLE. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO FORM DUE TO TERRAIN CIRCULATIONS AS WELL AS ON THE DIFFERENTIAL HEATING BOUNDARY OF THE MARINE LAYER. SOME STORMS WILL BE CAPABLE OF STRONG UPDRAFTS AND THEREFORE DMG WINDS AND LARGE HAIL ARE POSSIBLE. SHEAR PROFILES INCREASE IN MAGNITUDE FROM THE CENTRAL FOOTHILLS TO THE POTOMAC HIGHLANDS AND THEREFORE A HIGHER CHANCE FOR SEVERE THUNDERSTORMS ACROSS THE POTOMAC HIGHLANDS. 11Z HRRR SHOWS CONVECTION STARTING AFTER 16Z TODAY. THE STORM MOTION WILL BRING SHOWERS AND THUNDERSTORMS NORTH AND EAST BUT THE STABLE AIRMASS WILL LIKELY CAUSE THUNDERSTORMS TO DISSAPTE. PREVIOUS DISCUSSION... ANY LEFTOVER CONVECTION THIS EVENING WILL DISSIPATE OVERNIGHT AND A SOUTHEAST FLOW IS EXPECTED AHEAD OF AN APPROACHING COLD FRONT AND BEHIND DEPARTING HIGH PRESSURE OFF THE NEW ENGLAND COAST. LOW CLOUDS ALONG WITH AREAS OF FOG AND DRIZZLE ARE EXPECTED OVERNIGHT. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... A STRONG UPPER-LEVEL TROUGH WILL DIG OVER THE MIDWEST AND GULF COAST STATES THURSDAY WHILE THE COLD FRONT ASSOCIATED WITH THIS TROUGH SLOWLY TRACKS EAST TOWARD OUR AREA BY LATE IN THE DAY. THE TROUGH AXIS WILL SWING TOWARD BEING NEGATIVELY TILTED...ALLOWING FOR MORE HEIGHT FALLS WITHIN THE WARM SECTOR. THE FORCING ALONG THE FRONT WILL BE QUITE STRONG DUE TO A STRONG PRESSURE GRADIENT BETWEEN THE FRONT AND HIGH PRESSURE OVER THE ATLANTIC OCEAN. THE STRONG FORCING WILL COMBINE WITH DEEP TROPICAL MOISTURE BEING ADVECTED INTO THE AREA AHEAD OF THE BOUNDARY...TO CAUSE WIDESPREAD SHOWERS WITH LOCALLY HEAVY RAINFALL AHEAD OF THE COLD FRONT. THIS ACTIVITY IS EXPECTED TO OVERSPREAD THE POTOMAC HIGHLANDS THURSDAY AFTERNOON. FURTHER EAST ACROSS THE WASHINGTON AND BALTIMORE METROPOLITAN AREAS...A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON BUT THE WIDESPREAD PRECIPITATION MAY REMAIN TO THE WEST DUE TO THE SLOW MOVEMENT OF THE COLD FRONT. DESPITE PLENTY OF CLOUD COVER...FAVORABLE SHEAR PROFILES AND HIGH DEWPOINTS SUGGEST THAT THERE IS A THREAT FOR SEVERE THUNDERSTORMS THURSDAY AFTERNOON. A SLOW BUT STEADY ARRIVAL OF THE MOISTURE PLUME EXPECTED LATE THU EVE. EARLIER IN THE DAY...THE PARENT UPPER TROUGH WILL HAVE DIVED DOWN WELL INTO THE LOWER MS VLY. THE HIGHLY AMPLIFIED TROUGH AXIS WILL ESSENTIALLY SCOOP A DENSE SECTOR OF GULF MOISTURE OVER A RELATIVELY THIN AXIS. THIS MOISTURE AXIS WILL BE JUST ON THE LEE SIDE OF THE UPPER TROUGH...BUILDING AND DRIFTING NNE ACROSS THE SRN APLCNS THU MRNG/AFTN. HEADING INTO THE LATE EVE/NIGHTTIME HRS...THE UPPER VORT POWERING THE TROUGH WILL BEGIN TO TILT NEGATIVELY WHICH IS AN INTENSIFICATION PHASE FOR THE SYSTEM - MAXIMIZING THE AMOUNT OF QPF POSSIBLE W/ THE SYSTEM. MOST MED RANGE MEMBERS GIVING THE WRN HALF OF OUR CWA A PORTION OF THE BULLSEYE FOR POTENTIAL QPF - MAINLY DURING THE THU LATE NIGHT AND EARLY MRNG HRS FRI. A FLASH FLOOD WATCH WILL LIKELY BE NEEDED WITHIN THE NEXT FORECAST PERIOD OR SO...WHICH THE SOLID CONSENSUS OF QPF DEPICTIONS. LOCALLY INTENSE RAINFALL AND EMBEDDED CONVECTIVE ELEMENTS WILL CREATE THE POTENTIAL FOR AT LEAST A COUPLE OF INCHES OF RAIN OVER THE SHEN VLY/APLCNS. A SFC LOW PRES SYSTEM WILL DEVELOP OFF THE LEE SIDE OF THE HIGHER TERRAIN AND STRENGTHEN AS IT EFFECTIVELY TRACKS RIGHT ACROSS OUR CWA. THE TRACK WILL DETERMINE THE CONVECTIVE POTENTIAL FOR THE AREA...THOUGH EMBEDDED ELEVATED CONVECTION AT VERY LEAST WILL BE POSSIBLE ACROSS THE REGION. THE MODERATE TO HEAVY RAIN BATCHES WILL CONTINUE TO MOVE EWD DURING THE PREDAWN HRS FRI OVER THE BLUE RIDGE AND EAST. THE I-95 CORRIDOR WILL BE HIGHLIGHTED DURING THE FIRST-HALF OF THE DAY FRI...W/ EMBEDDED AREAS OF HEAVY RAIN SPREADING ACROSS THE AREA AND A STILL INTENSE LOW LEVEL JET HELPING TO KEEP THE INTENSITY OF THE SYSTEM INTACT. A QUICK END TO THE PRECIP LINE WILL ARRIVE TOWARD THE MID-LATE AFTN W/ ONLY A FEW RESIDUAL SHOWERS OCCURRING IN THE BACK EDGE SUBSIDENCE REGION. THE MOISTURE AXIS WILL DISSIPATE AS IT ARRIVES OVER DELMARVA AND MOVES OFF THE COAST LATE FRI EVE. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AN UPPER LOW DRIFTING DOWN FROM SOUTH OF THE HUDSON BAY AROUND WILL ROTATE AROUND THE GREAT LAKES INTO THE COMING WEEKEND...KEEPING OUR AREA QUITE COOL AND RELATIVELY DRY. THE "WEATHER" FROM THIS FEATURE WILL MAKE IT FEEL MORE LIKE MARCH THAN MAY...EVEN THOUGH AVG TEMPS FOR MID-MAY ARE IN THE M70S. A SLOW MOVING AND COLD UPPER LOW TAKING A FEW DAYS TO EXIT THE NORTHEAST WILL KEEP US IN THIS PATTERN WELL INTO NEXT WEEK. IT MAY BE SEVERAL MORE DAYS BEFORE WE GET ANYWHERE CLOSE TO 80 DEG OR MORE...BASED ON THE PATTERN SETTING UP FOR NEXT WEEK. THE HUDSON BAY LOW WILL SLOWLY DRIFT OFF THE NEW ENGLAND COAST AS AN UPPER RIDGE BUILDS TO THE WEST. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... IFR CONDITIONS ARE EXPECTED THROUGH MID-MORNING DUE TO LOW CLOUDS ALONG WITH AREAS OF FOG AND DRIZZLE. CIGS SHOULD IMPROVE TO MVFR LEVELS LATE THIS MORNING AND AFTERNOON...BUT MORE IFR/SUBIFR CONDITIONS ARE EXPECTED LATE TONIGHT INTO EARLY THURSDAY. CIGS/VSBYS SHOULD IMPROVE THURSDAY AFTERNOON. A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING MAINLY FOR CHO AND MRB...AND AGAIN THURSDAY AFTERNOON FOR ALL TERMINALS. A COLD FRONT WILL CAUSE WIDESPREAD SHOWERS WITH LOCALLY HEAVY RAINFALL AND A FEW THUNDERSTORMS THURSDAY NIGHT INTO FRIDAY. CONDITIONS WILL IMPROVE LATER FRIDAY. HIGH PRESSURE WILL BUILD OVERHEAD DURING THE WEEKEND. A STRONG LOW PRESSURE SYSTEM WILL MOVE ACROSS THE REGION FROM LATE THU INTO FRI. MAINLY PERIODS OF HEAVY RAIN WOULD BE THE CONCERN...W/ BREEZY SFC WINDS BUT EVEN STRONGER LOW LEVEL FLOW - A GOOD 30-50KT IN THE BOUNDARY LAYER OUT AHEAD OF THE SFC LOW LATE THU INTO EARLY FRI. A COLD FRONT WILL PUSH THE PRECIP AND ANY EMBEDDED TSTMS OFF THE COAST BY LATE FRI...W/ COOLER AND DRIER AIR BEING USHERED IN FOR THE COMING WEEKEND. && .MARINE... AN EASTERLY FLOW THIS MORNING WILL TURN TO THE SOUTHEAST THIS AFTERNOON AS HIGH PRESSURE MOVES OFF THE NEW ENGLAND COAST. THE SOUTHEAST FLOW WILL CONTINUE THROUGH THURSDAY. THE PRESSURE GRADIENT WILL INCREASE DURING THIS TIME AND A SMALL CRAFT ADVISORY IS IN EFFECT FOR THURSDAY AFTERNOON. HOWEVER...WIND GUSTS MAY APPROACH SCA CRITERIA TONIGHT THROUGH THURSDAY MORNING...BUT GUSTS HAVE BEEN CAPPED AROUND 15 KNOTS FOR NOW DUE TO THE RELATIVELY COOLER WATERS AND WEAKER PRESSURE GRADIENT. SFC WINDS WILL INCREASE OUT OF THE S-SE THU AFTN/EVE AHEAD OF A SFC LOW PRES SYSTEM. WIDESPREAD RAIN AND ISOLATED TSTMS WILL ARRIVE INTO THE EARLY MRNG HRS FRI. WINDS WILL MAX-OUT IN THE UPPER SCA/LOW-END GALE RANGES AS THE LOW PUSHES EAST AND MOVES OVER THE WATERS. WINDS BEHIND THE SYSTEM WILL SUBSIDE WELL BELOW SCA CRIT HEADING INTO THE WEEKEND...W/ ONLY A LIGHT W/NW BREEZE EXPECTED. THIS WILL ALSO LAST INTO EARLY NEXT WEEK. && .TIDES/COASTAL FLOODING... TIDAL ANOMALIES HAVE INCREASED UP TO AROUND ONE-HALF FOOT ABOVE NORMAL THIS MORNING DUE TO AN ONSHORE FLOW. THE ONSHORE FLOW SHOULD REMAIN WEAK ENOUGH TO KEEP WATER LEVELS BELOW MINOR COASTAL FLOODING THRESHOLDS. THE HIGH TIDE THIS AFTERNOON INTO THIS EVENING WILL BE THE LOWER OF THE TWO...SO WATER LEVELS SHOULD REMAIN BELOW MINOR FLOODING THRESHOLDS...DESPITE AN INCREASE IN TIDAL ANOMALIES. THE ONSHORE FLOW WILL CONTINUE TONIGHT THROUGH THURSDAY NIGHT AND POSSIBLY INTO FRIDAY BEFORE TURNING OFFSHORE BEHIND A COLD FRONT LATER FRIDAY. DESPITE THE ONSHORE FLOW REMAINING WEAK TONIGHT...MINOR COASTAL FLOODING IS POSSIBLE WITH THE HIGH TIDE CYCLE LATE TONIGHT INTO THURSDAY MORNING SINCE IT WILL BE THE HIGHER OF THE TWO. THE ONSHORE FLOW WILL STRENGTHEN LATER THURSDAY THROUGH THURSDAY NIGHT. MINOR FLOODING IS LIKELY NEAR HIGH TIDES DURING THIS TIME. TIDAL ANOMALIES WILL GRADUALLY DECREASE FRIDAY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM NOON TO 6 PM EDT THURSDAY FOR ANZ530>543. && $$ SYNOPSIS...BJL NEAR TERM...HAS/BJL SHORT TERM...BJL/GMS LONG TERM...BJL/GMS AVIATION...BJL/HAS/GMS MARINE...BJL/HAS/GMS TIDES/COASTAL FLOODING...LWX
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1142 AM EDT WED MAY 14 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 527 AM EDT WED MAY 14 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A HIGH AMPLITUDE PATTERN OVER NAMERICA...CONSISTING OF A RIDGE ALONG THE W COAST AND A TROF EXTENDING FROM NRN CANADA TO TX. WITHIN THE TROF...THE NRN STREAM FEATURES A MIDLEVEL LOW OVER NRN ONTARIO TO THE SW OF HUDSON BAY... BUT NRN STREAM ENERGY IS DIVING S ALONG THE SASKATCHEWAN/MANITOBA BORDER REGION. IN THE SRN PART OF THE TROF...A SHORTWAVE IS OVER TX/OK. EXACTLY HOW THE AFOREMENTIONED SOUTHWARD DIVING NRN STREAM ENERGY INTERACTS WITH THE SRN PLAINS SHORTWAVE WILL BE KEY TO THE WEATHER IN THE NEXT COUPLE OF DAYS...INCLUDING THE POTENTIAL FOR VERY LATE SEASON ACCUMULATING SNOW WHICH IS LOOKING A BIT MORE LIKELY FOR SOME AREAS. DRIER AIR MASS HAS PUSHED INTO THE FCST AREA OVER THE LAST 12-18HRS. WHILE 00Z KGRB SOUNDING SHOWED DRY LOW TO MID LEVELS...UPSTREAM KINL SOUNDING SHOWED MOISTURE EXTENDING UP TO AROUND 700MB. SOME OF THIS MOISTURE WILL PROBABLY MANIFEST ITSELF AS HIGHER BASED SCT-BKN CU/STRATOCU THIS AFTN...ESPECIALLY INLAND FROM LAKE SUPERIOR. ISOLD/SCT -SHRA WERE COMMON UPSTREAM YESTERDAY...BUT WITH DRY BOUNDARY LAYER AND LOW-LEVEL FLOW HERE TRENDING ANTICYCLONIC RATHER THAN CYCLONIC AS IT WAS YESTERDAY WHERE THE SHRA WERE OCCURRING... DON`T EXPECT ANY -SHRA/SPRINKLES IN THE FCST AREA TODAY. LAKE BREEZES WILL DEVELOP OFF LAKE SUPERIOR AND LAKE MICHIGAN TODAY... KEEPING LAKESIDE LOCATIONS CHILLY THIS AFTN. INLAND...DEEP MIXING TO TOWARD 750MB ON FCST SOUNDINGS YIELDS MAX TEMPS IN THE MID TO UPPER 50S. MAY SEE A FEW READINGS AROUND 60F OVER THE SCNTRL. DWPTS WILL MIX OUT INTO THE MID 20S THIS AFTN...RESULTING IN MIN RH DOWN AROUND 30PCT IN THE INTERIOR W HALF THIS AFTN. FAIRLY LIGHT WINDS/MOIST GROUND WILL LIMIT FIRE WX CONCERNS. NRN STREAM ENERGY DIVING S INTO THE NRN PLAINS TODAY WILL CONTINUE S INTO IA TONIGHT. THIS WILL HELP PULL SRN PLAINS SHORTWAVE N INTO IL BY SUNRISE WED WITH ORGANIZING SFC LOW LIFTING INTO ERN IN. PUSH OF WAA/ISENTROPIC ASCENT AND DEEP LAYER FORCING AHEAD OF WAVE ALONG WITH STRONG MOISTURE TRANSPORT WILL LEAD TO EXPANDING PCPN SHIELD LIFTING N INTO THE GREAT LAKES TONIGHT. NRN FRINGE OF PCPN MAY REACH THE FAR E AND SE FCST AREA AROUND SUNRISE THU. INCLUDED SCHC POPS IN THAT AREA. WETBULB ZERO HEIGHTS/1000-850MB THICKNESS SUGGEST THERE COULD BE SOME SNOWFLAKES MIXED IN WITH THE RAIN IF PCPN DOES IN FACT ARRIVE LATE TONIGHT. OTHERWISE...EXPECT INCREASING CLOUDS TONIGHT WITH LOW TEMPS IN THE 30S. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 447 AM EDT WED MAY 14 2014 ...MODELS TRENDING BACK TO STRONGER SYSTEM/ACCUMULATING SNOW TO END THE WEEK... HIGHLY AMPLIFIED UPPER LEVEL PATTERN IN PLACE LATE THIS WEEK AS UPPER TROUGH WITH H5 HEIGHTS OF 2-3 STANDARD DEVIATIONS BLO CLIMO CENTERED OVER THE MIDDLE MISSISSIPPI RIVER VALLEY. STILL HINTS THAT THIS UPPER TROUGH BECOMES CLOSED OFF BY FRIDAY AS IT CROSSES THE WESTERN GREAT LAKES. COUPLE OF SHORTWAVES LIFTING NEARLY DUE NORTH ON LEAD FLANK OF THE UPPER LOW MAY LOOKS TO BRING AT LEAST A BRIEF SHOT OF WINTRY PRECIP TO UPPER LAKES LATER THURSDAY INTO FRIDAY. PORTION OF TROUGH MOVES TOWARD MID ATLANTIC THIS WEEKEND WHILE HEIGHTS SLOWLY BEGIN TO REBOUND OVER THE GREAT LAKES. RIDGING ALOFT MAKES RETURN TO UPPER LAKES REGION EARLY NEXT WEEK BUT SINCE THE LOW-LEVELS REMAIN UNDER FIRM INFLUENCE OF SFC HIGH AND WORKED OVER CP AIRMASS...ONLY MODERATE WARMING WILL OCCUR BY NEXT WEEK WITH TEMPS LIKELY REMAINING AT OR BLO NORMAL. PRIMARY FOCUS IN THE LONG TERM IS ON THE SYSTEM AND POSSIBLE WINTRY PRECIPITATION THURSDAY INTO FRIDAY. APPEARS THAT THE 00Z ECMWF RUN FROM TUE 5/13 WAS AN ABERATION...AS WITH THE 12Z RUN ON TUE 5/13 THE UPPER LOW IS CLOSED OFF AGAIN...DRAWING THE PRIMARY SHORTWAVE AND SFC WAVE BACK WEST AGAIN SPREADING QPF OVER MAINLY EAST THIRD OF CWA THROUGH 00Z FRIDAY. LATEST SET OF MODEL RUNS NOT SET ON ANY ONE IDEA THOUGH AS ESSENTIALLY WE CONTINUE TO SEE ALL THE DIFFERENT ENSEMBLE MEMBERS WITH THIS SYSTEM. EVEN WITH THAT UNCERTAINTY THOUGH...ENOUGH OF TREND EMERGING TO INCREASE POPS SIGNIFICANTLY THURSDAY/THURSDAY NIGHT/FRIDAY. NAM FARTHEST WEST WITH THE INITIAL SHORTWAVE AND PV ANAMOLY AND ASSOCIATED QPF ON THURSDAY. FARTHEST EAST IDEA IS UKMET WHICH FOCUSES MOST OF ITS FORCING/MOISTURE WITH THE SHORTWAVE OVER FAR EASTERN UPR MICHIGAN AND TO THE EAST. LATEST GFS AND GEM ALONG WITH 12Z ECMWF ARE IN BETWEEN THESE TWO EXTREMES AND FOCUS WHAT LOOKS LIKE AREA OF TROWAL/DEFORMATION PRECIP OVER THE EAST HALF OF CWA THROUGH 00Z FRIDAY. PTYPE FOR THIS INITIAL WAVE OF PRECIP LIKELY WOULD BE MOSTLY A MIX OF RAIN/SNOW...THOUGH HIGHER TERRAIN AREAS OF NCNTRL UPR MICHIGAN COULD SEE JUST SNOW BY LATER AFTN. LATER THURSDAY NIGHT INTO FRIDAY THERE ARE HINTS FROM THE ECMWF AND ESPECIALLY THE GFS/NAM THAT MID-LEVEL FRONTOGENESIS H7-H6 IMPACTS LK SUPERIOR AND NORTH CENTRAL AND PERHAPS NORTHWEST CWA AT LEAST FRIDAY MORNING AS TEMP GRADIENT STRENGTHENS AT H7 DUE TO PERSISTENT COLD/WARM ADVECTION ALONG AXIS OVER CNTRL LK SUPERIOR. MAY BE GETTING LOST IN THE DETAILS HERE...BUT FN CONVERGENCE IS DECENT AND THERE IS ALSO FS VECTOR CONVERGENCE THAT SUGGESTS AN AREA OF WIDESPREAD PRECIPITATION WOULD PIVOT ACROSS THOSE PORTIONS OF THE CWA. ADDED LIFT WILL BE PROVIDED BY NNW WINDS UPSLOPING OVER HIGHER TERRAIN OF NW AND NCNTRL CWA. AGAIN...THIS IS ONE MODEL RUN OF MANY DIFFERENT TAKES ON THIS SYSTEM...BUT GIVEN UPPER LOW DEEPENING AND SHORTWAVES WRAPPING INTO THE BACK SIDE OF THE UPPER LOW...THE GENERAL IDEA OF ENHANCED FRONTOGENESIS OCCURRING HAS SOME MERIT. UNCERTAINTY OF THAT FEATURES PLACEMENT IS MAIN ISSUE FROM INTRODUCING THAT KIND OF DETAIL TO FORECAST ATTM. TEMP GRADIENT ALOFT WEAKENS IN THE AFTN...SO INTENSITY OF MID-LEVEL LIFT/FGEN SHOULD DO LIKEWISE. LINGERING LOW-LEVEL MOISTURE AND UPSLOPE LIFTING SHOULD KEEP LIGHT PRECIP GOING INTO THE AFTN THOUGH. BASED ON LIFT OVER THE AREA WITH H85 TEMPS WELL BLO ZERO AND 1000-850MB THICKNESSES BLO 1300M...AND NOT MUCH OF ABOVE FREEZING NEAR SFC LAYER SHOWING UP IN THE SOUNDINGS...PTYPE THURSDAY NIGHT INTO FRIDAY MORNING FOR THE MOST PART WILL BE SNOW ACROSS MUCH OF CWA. BY FRIDAY AFTN...BLYR WARMING WILL ALLOW FOR MIX OF RAIN/SNOW SHOWERS OVER LOWER ELEVATIONS OF CWA...ESPECIALLY EASTERN HALF. NOW THE MAIN QUESTION TURNS TO SNOW AMOUNTS. AS WITH ANY SNOW THIS LATE IN THE SEASON THE MAIN HURDLES OF WARM GROUND TEMPS...SNOW INTENSITY...TIME OF DAY...ALL HAVE TO BE CONSIDERED. BUT...AT LEAST IN THESE LATITUDES IT IS NOT UNHEARD OF AT ALL TO SEE SIGNIFICANT LATE SEASON SNOWS. LOCAL RECORDS/OTHER ACCOUNTS INCLUDE A SEVERAL INCH SNOWSTORM THAT OCCURED OVER HIGHER TERRAIN OF NORTH CENTRAL UPR MICHIGAN EARLY IN JUNE OF 1945...AND THERE HAVE BEEN OTHERS THAN HAVE OCCURRED IN LATE MAY EVEN AS FAR SOUTH AS WISCONSIN. THIS SYSTEM WILL HAVE TO BE WATCHED...AS IF THE REVERSAL OF TRACK MAJORITY OF MODELS ARE SHOWING COMES TO FRUITION...THERE IS A HIGHER POTENTIAL TO SEE SEVERAL INCHES OF WET SNOW OVER PARTS OF UPR MICHIGAN. LOOKING AT THE FACTORS MENTIONED ABOVE...GOOD PART OF SNOW OCCURS THURSDAY NIGHT INTO FRIDAY MORNING...SO THE INSOLATION WILL BE MINIMAL FACTOR IN CUTTING DOWN ON AMOUNTS...AND SNOW MAY FALL AT GOOD CLIP LATER THURSDAY NIGHT INTO FRIDAY...ESPECIALLY IF THE FGEN AND DEFORMATION AREA INCREASES AS SOME MODELS INDICATE. BEST GUESS TO START IS PROBABILITIES ARE PRETTY HIGH THAT AT LEAST A FEW INCHES OF WET SNOW WILL OCCUR OVER THE HIGHER TERRAIN OF THE KEWEENAW PENINSULA...PERHAPS AS FAR WEST AS THE PORCUPINE MOUNTAINS...AND ALSO OVER THE HIGHER TERRAIN OF BARAGA AND MARQUETTE COUNTIES. THESE AREAS WILL ALSO HAVE THE ADDED BENEFIT OF NW WINDS PROVIDING UPSLOPE LIFT. NOTEABLE IS THAT SOME OF THE ENSEMBLE OUTPUT FROM THE 03Z SREF MEMBERS TRENDED HIGHER THAN PREVIOUS RUNS...INDICATING MUCH MORE SNOW...WITH A FEW MEMBERS EVEN PRINTING OUT AMOUNTS OVER 6 INCHES...WITH ISOLATED MEMBERS OVER 10 INCHES. HOWEVER...SREF OUTPUT IS SEEMING TO KEY ON LARGER SCALE FORCING IMPACTING MOST OF UPR MICHIGAN AS IT SHOWS SEVERAL INCHES OF SNOW AS FAR SOUTH AS KIMT AND EAST AS KERY. SREF MEAN SHOWS 2-4 INCHES OVER THE HIGHER TERRAIN AREAS NEAR LK SUPERIOR AND PERHAPS AN INCH OR TWO IN THAT IMT TO ERY CORRIDOR. ENOUGH EVIDENCE TO PUT MENTION OF THIS SYSTEM INTO THE HAZARDOUS WEATHER OUTLOOK AND EHWO GRAPHICS. AND THEN WE WILL WAIT TO SEE WHAT THE LATER MODEL RUNS INDICATE. SYSTEM...HOWEVER STRONG IT ENDS UP BEING...WILL LEAVE A WELL ESTABLISHED CP AIRMASS OVER THE UPPER GREAT LAKES ON SATURDAY. HOWEVER...INLAND AREAS WILL MIX TO AROUND H85 SO TEMPS WILL PUSH INTO THE 50S DEGREES THERE. RIDGE AT THE SFC MOVING OVERHEAD WILL SUPPORT LAKE BREEZES WHICH WILL PACK A PUNCH NEAR LK SUPERIOR /KEEPING TEMPS IN THE LOWER 40S/ AS WATERS OFFSHORE ARE STILL VERY COLD OR EVEN ICE COVERED IN SOME AREAS. SFC RIDGE SLOWLY SLIDES ACROSS INTO MONDAY. TEMPS SUNDAY AND MONDAY WILL MODERATE INLAND WITH READINGS WELL INTO THE 60S BY MONDAY. ONSHORE WINDS WILL CONTINUE TO KEEP GREAT LAKES SHORES MUCH COOLER. THE COOL/DRY AIRMASS AND THE RIDGE WILL ALLOW NIGHTTIME LOWS TO DIP BELOW FREEZING FOR MANY SPOTS INLAND SATURDAY NIGHT THROUGH MONDAY NIGHT. NEAR THE SHORE...READINGS WILL LIKELY STAY JUST ABOVE FREEZING. NEXT CHANCE OF RAIN...YES JUST RAIN...ARRIVES LATER MONDAY AND MORE SO INTO TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1142 AM EDT WED MAY 14 2014 SCT-BKN LATE MORNING TO AFTERNOON CU HAVE DEVELOPED IN OUR OTHERWISE DRY LOW-LEVEL ENVIRONMENT. A FEW HIGH MVFR CEILINGS HAVE BEEN REPORTED UPSTREAM...BUT THEY ARE MORE TEMPORARY AND SHOULD COME IN HIGHER AS THEY MOVE CLOSER TO IWD AND CMX. AN AFTERNOON LAKE BREEZE SLIDING IN AT SAW WILL PUSH MOST OF THE CLOUDS S OF THE AIRPORT BY AROUND 20Z. ANY GUSTY WINDS /NEARING 25KTS AT CMX/ WILL QUICKLY DIMINISH LATE THIS AFTERNOON...WITH WINDS GENERALLY 5-10KTS OR LESS OVERNIGHT. WINDS WILL INCREASE AFTER 6-10Z THURSDAY /GUSTS NEARING 25KTS OUT OF THE N AT SAW BY LATE MORNING/ IN RESPONSE TO THE INCREASING PRESSURE GRADIENT BETWEEN THE STRONG HIGH PRESSURE SYSTEM SET UP ACROSS THE DAKOTAS/MN/ONTARIO...AND LOW SLIDING FROM INDIANA AT DAYBREAK TO E LOWER MI AND GREATER LAKE HURON BY 18Z THURSDAY. WITH THE ASSISTANCE OF UPSLOPE N WINDS...SAW COULD GET SOME RAIN BY 18Z THURSDAY. A FEW FLURRIES OR LIGHT SNOW MAY ALSO BE MIXED IN...PARTICULARLY BY THE EVENING HOURS. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 527 AM EDT WED MAY 14 2014 EXPECT WESTERLY WINDS UP TO 15-25KT OVER THE W HALF OF LAKE SUPERIOR TODAY AND MOSTLY UNDER 20KT OVER THE E HALF. WINDS WILL DIMINISH TONIGHT UNDER WEAKENING PRES GRADIENT. ATTENTION THEN TURNS TO SFC LOW PRES THAT WILL LIFT N ACROSS LAKE HURON THU AND THEN TO JAMES BAY BY FRI NIGHT. TIGHTENING PRES GRADIENT WILL RESULT IN INCREASING WINDS THU...MAINLY OVER THE E HALF OF LAKE SUPERIOR. NORTHERLY WINDS THU NIGHT WILL REACH 20-30KT OVER THE E HALF. THE STRONGER WINDS OVER THE ERN LAKE WILL BEGIN TO DIMINISH LATER FRI AS THE LOW MOVES FARTHER AWAY. WINDS WILL BE MUCH LIGHTER OVER WRN LAKE SUPERIOR THU AND FRI. WEAK PRES GRADIENT OVER THE WEEKEND WILL LEAD TO WINDS UNDER 20KT. && .HYDROLOGY... ISSUED AT 527 AM EDT WED MAY 14 2014 PERIODS OF RAIN AND SNOW ARE EXPECTED TO DEVELOP THU AND CONTINUE INTO FRI. SOME LIGHT PCPN WILL LINGER ON INTO SAT. RIGHT NOW...PCPN AMOUNTS ARE EXPECTED TO BE LIGHT ENOUGH SO THAT THERE IS LITTLE IMPACT ON AREA RIVERS/STREAMS...AND SINCE NO SIGNIFICANT PCPN IS IN THE OFFING THRU EARLY NEXT WEEK...EXPECT ALL RIVERS TO HAVE AN OVERALL DOWNWARD TREND OVER THE NEXT SEVERAL DAYS. HOWEVER...THERE ARE SOME INDICATIONS THAT PCPN AMOUNTS MAY BE HEAVIER THAN CURRENTLY EXPECTED THU/FRI OVER NRN UPPER MI. IF SO...HIGHER RIVER LEVELS WILL BE SUSTAINED AND COULD RISE SOME FRI INTO SAT. THE MAIN RIVERS OF CONCERN ARE OVER THE W HALF OF UPPER MI... INCLUDING THE STURGEON RIVER AT CHASSELL AND THE MICHIGAMME RIVER AT REPUBLIC...WITCH LAKE...AND CRYSTAL FALLS. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...KF MARINE...ROLFSON HYDROLOGY...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
741 AM EDT WED MAY 14 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 527 AM EDT WED MAY 14 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A HIGH AMPLITUDE PATTERN OVER NAMERICA...CONSISTING OF A RIDGE ALONG THE W COAST AND A TROF EXTENDING FROM NRN CANADA TO TX. WITHIN THE TROF...THE NRN STREAM FEATURES A MIDLEVEL LOW OVER NRN ONTARIO TO THE SW OF HUDSON BAY... BUT NRN STREAM ENERGY IS DIVING S ALONG THE SASKATCHEWAN/MANITOBA BORDER REGION. IN THE SRN PART OF THE TROF...A SHORTWAVE IS OVER TX/OK. EXACTLY HOW THE AFOREMENTIONED SOUTHWARD DIVING NRN STREAM ENERGY INTERACTS WITH THE SRN PLAINS SHORTWAVE WILL BE KEY TO THE WEATHER IN THE NEXT COUPLE OF DAYS...INCLUDING THE POTENTIAL FOR VERY LATE SEASON ACCUMULATING SNOW WHICH IS LOOKING A BIT MORE LIKELY FOR SOME AREAS. DRIER AIR MASS HAS PUSHED INTO THE FCST AREA OVER THE LAST 12-18HRS. WHILE 00Z KGRB SOUNDING SHOWED DRY LOW TO MID LEVELS...UPSTREAM KINL SOUNDING SHOWED MOISTURE EXTENDING UP TO AROUND 700MB. SOME OF THIS MOISTURE WILL PROBABLY MANIFEST ITSELF AS HIGHER BASED SCT-BKN CU/STRATOCU THIS AFTN...ESPECIALLY INLAND FROM LAKE SUPERIOR. ISOLD/SCT -SHRA WERE COMMON UPSTREAM YESTERDAY...BUT WITH DRY BOUNDARY LAYER AND LOW-LEVEL FLOW HERE TRENDING ANTICYCLONIC RATHER THAN CYCLONIC AS IT WAS YESTERDAY WHERE THE SHRA WERE OCCURRING... DON`T EXPECT ANY -SHRA/SPRINKLES IN THE FCST AREA TODAY. LAKE BREEZES WILL DEVELOP OFF LAKE SUPERIOR AND LAKE MICHIGAN TODAY... KEEPING LAKESIDE LOCATIONS CHILLY THIS AFTN. INLAND...DEEP MIXING TO TOWARD 750MB ON FCST SOUNDINGS YIELDS MAX TEMPS IN THE MID TO UPPER 50S. MAY SEE A FEW READINGS AROUND 60F OVER THE SCNTRL. DWPTS WILL MIX OUT INTO THE MID 20S THIS AFTN...RESULTING IN MIN RH DOWN AROUND 30PCT IN THE INTERIOR W HALF THIS AFTN. FAIRLY LIGHT WINDS/MOIST GROUND WILL LIMIT FIRE WX CONCERNS. NRN STREAM ENERGY DIVING S INTO THE NRN PLAINS TODAY WILL CONTINUE S INTO IA TONIGHT. THIS WILL HELP PULL SRN PLAINS SHORTWAVE N INTO IL BY SUNRISE WED WITH ORGANIZING SFC LOW LIFTING INTO ERN IN. PUSH OF WAA/ISENTROPIC ASCENT AND DEEP LAYER FORCING AHEAD OF WAVE ALONG WITH STRONG MOISTURE TRANSPORT WILL LEAD TO EXPANDING PCPN SHIELD LIFTING N INTO THE GREAT LAKES TONIGHT. NRN FRINGE OF PCPN MAY REACH THE FAR E AND SE FCST AREA AROUND SUNRISE THU. INCLUDED SCHC POPS IN THAT AREA. WETBULB ZERO HEIGHTS/1000-850MB THICKNESS SUGGEST THERE COULD BE SOME SNOWFLAKES MIXED IN WITH THE RAIN IF PCPN DOES IN FACT ARRIVE LATE TONIGHT. OTHERWISE...EXPECT INCREASING CLOUDS TONIGHT WITH LOW TEMPS IN THE 30S. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 447 AM EDT WED MAY 14 2014 ...MODELS TRENDING BACK TO STRONGER SYSTEM/ACCUMULATING SNOW TO END THE WEEK... HIGHLY AMPLIFIED UPPER LEVEL PATTERN IN PLACE LATE THIS WEEK AS UPPER TROUGH WITH H5 HEIGHTS OF 2-3 STANDARD DEVIATIONS BLO CLIMO CENTERED OVER THE MIDDLE MISSISSIPPI RIVER VALLEY. STILL HINTS THAT THIS UPPER TROUGH BECOMES CLOSED OFF BY FRIDAY AS IT CROSSES THE WESTERN GREAT LAKES. COUPLE OF SHORTWAVES LIFTING NEARLY DUE NORTH ON LEAD FLANK OF THE UPPER LOW MAY LOOKS TO BRING AT LEAST A BRIEF SHOT OF WINTRY PRECIP TO UPPER LAKES LATER THURSDAY INTO FRIDAY. PORTION OF TROUGH MOVES TOWARD MID ATLANTIC THIS WEEKEND WHILE HEIGHTS SLOWLY BEGIN TO REBOUND OVER THE GREAT LAKES. RIDGING ALOFT MAKES RETURN TO UPPER LAKES REGION EARLY NEXT WEEK BUT SINCE THE LOW-LEVELS REMAIN UNDER FIRM INFLUENCE OF SFC HIGH AND WORKED OVER CP AIRMASS...ONLY MODERATE WARMING WILL OCCUR BY NEXT WEEK WITH TEMPS LIKELY REMAINING AT OR BLO NORMAL. PRIMARY FOCUS IN THE LONG TERM IS ON THE SYSTEM AND POSSIBLE WINTRY PRECIPITATION THURSDAY INTO FRIDAY. APPEARS THAT THE 00Z ECMWF RUN FROM TUE 5/13 WAS AN ABERATION...AS WITH THE 12Z RUN ON TUE 5/13 THE UPPER LOW IS CLOSED OFF AGAIN...DRAWING THE PRIMARY SHORTWAVE AND SFC WAVE BACK WEST AGAIN SPREADING QPF OVER MAINLY EAST THIRD OF CWA THROUGH 00Z FRIDAY. LATEST SET OF MODEL RUNS NOT SET ON ANY ONE IDEA THOUGH AS ESSENTIALLY WE CONTINUE TO SEE ALL THE DIFFERENT ENSEMBLE MEMBERS WITH THIS SYSTEM. EVEN WITH THAT UNCERTAINTY THOUGH...ENOUGH OF TREND EMERGING TO INCREASE POPS SIGNIFICANTLY THURSDAY/THURSDAY NIGHT/FRIDAY. NAM FARTHEST WEST WITH THE INITIAL SHORTWAVE AND PV ANAMOLY AND ASSOCIATED QPF ON THURSDAY. FARTHEST EAST IDEA IS UKMET WHICH FOCUSES MOST OF ITS FORCING/MOISTURE WITH THE SHORTWAVE OVER FAR EASTERN UPR MICHIGAN AND TO THE EAST. LATEST GFS AND GEM ALONG WITH 12Z ECMWF ARE IN BETWEEN THESE TWO EXTREMES AND FOCUS WHAT LOOKS LIKE AREA OF TROWAL/DEFORMATION PRECIP OVER THE EAST HALF OF CWA THROUGH 00Z FRIDAY. PTYPE FOR THIS INITIAL WAVE OF PRECIP LIKELY WOULD BE MOSTLY A MIX OF RAIN/SNOW...THOUGH HIGHER TERRAIN AREAS OF NCNTRL UPR MICHIGAN COULD SEE JUST SNOW BY LATER AFTN. LATER THURSDAY NIGHT INTO FRIDAY THERE ARE HINTS FROM THE ECMWF AND ESPECIALLY THE GFS/NAM THAT MID-LEVEL FRONTOGENESIS H7-H6 IMPACTS LK SUPERIOR AND NORTH CENTRAL AND PERHAPS NORTHWEST CWA AT LEAST FRIDAY MORNING AS TEMP GRADIENT STRENGTHENS AT H7 DUE TO PERSISTENT COLD/WARM ADVECTION ALONG AXIS OVER CNTRL LK SUPERIOR. MAY BE GETTING LOST IN THE DETAILS HERE...BUT FN CONVERGENCE IS DECENT AND THERE IS ALSO FS VECTOR CONVERGENCE THAT SUGGESTS AN AREA OF WIDESPREAD PRECIPITATION WOULD PIVOT ACROSS THOSE PORTIONS OF THE CWA. ADDED LIFT WILL BE PROVIDED BY NNW WINDS UPSLOPING OVER HIGHER TERRAIN OF NW AND NCNTRL CWA. AGAIN...THIS IS ONE MODEL RUN OF MANY DIFFERENT TAKES ON THIS SYSTEM...BUT GIVEN UPPER LOW DEEPENING AND SHORTWAVES WRAPPING INTO THE BACK SIDE OF THE UPPER LOW...THE GENERAL IDEA OF ENHANCED FRONTOGENESIS OCCURRING HAS SOME MERIT. UNCERTAINTY OF THAT FEATURES PLACEMENT IS MAIN ISSUE FROM INTRODUCING THAT KIND OF DETAIL TO FORECAST ATTM. TEMP GRADIENT ALOFT WEAKENS IN THE AFTN...SO INTENSITY OF MID-LEVEL LIFT/FGEN SHOULD DO LIKEWISE. LINGERING LOW-LEVEL MOISTURE AND UPSLOPE LIFTING SHOULD KEEP LIGHT PRECIP GOING INTO THE AFTN THOUGH. BASED ON LIFT OVER THE AREA WITH H85 TEMPS WELL BLO ZERO AND 1000-850MB THICKNESSES BLO 1300M...AND NOT MUCH OF ABOVE FREEZING NEAR SFC LAYER SHOWING UP IN THE SOUNDINGS...PTYPE THURSDAY NIGHT INTO FRIDAY MORNING FOR THE MOST PART WILL BE SNOW ACROSS MUCH OF CWA. BY FRIDAY AFTN...BLYR WARMING WILL ALLOW FOR MIX OF RAIN/SNOW SHOWERS OVER LOWER ELEVATIONS OF CWA...ESPECIALLY EASTERN HALF. NOW THE MAIN QUESTION TURNS TO SNOW AMOUNTS. AS WITH ANY SNOW THIS LATE IN THE SEASON THE MAIN HURDLES OF WARM GROUND TEMPS...SNOW INTENSITY...TIME OF DAY...ALL HAVE TO BE CONSIDERED. BUT...AT LEAST IN THESE LATITUDES IT IS NOT UNHEARD OF AT ALL TO SEE SIGNIFICANT LATE SEASON SNOWS. LOCAL RECORDS/OTHER ACCOUNTS INCLUDE A SEVERAL INCH SNOWSTORM THAT OCCURED OVER HIGHER TERRAIN OF NORTH CENTRAL UPR MICHIGAN EARLY IN JUNE OF 1945...AND THERE HAVE BEEN OTHERS THAN HAVE OCCURRED IN LATE MAY EVEN AS FAR SOUTH AS WISCONSIN. THIS SYSTEM WILL HAVE TO BE WATCHED...AS IF THE REVERSAL OF TRACK MAJORITY OF MODELS ARE SHOWING COMES TO FRUITION...THERE IS A HIGHER POTENTIAL TO SEE SEVERAL INCHES OF WET SNOW OVER PARTS OF UPR MICHIGAN. LOOKING AT THE FACTORS MENTIONED ABOVE...GOOD PART OF SNOW OCCURS THURSDAY NIGHT INTO FRIDAY MORNING...SO THE INSOLATION WILL BE MINIMAL FACTOR IN CUTTING DOWN ON AMOUNTS...AND SNOW MAY FALL AT GOOD CLIP LATER THURSDAY NIGHT INTO FRIDAY...ESPECIALLY IF THE FGEN AND DEFORMATION AREA INCREASES AS SOME MODELS INDICATE. BEST GUESS TO START IS PROBABILITIES ARE PRETTY HIGH THAT AT LEAST A FEW INCHES OF WET SNOW WILL OCCUR OVER THE HIGHER TERRAIN OF THE KEWEENAW PENINSULA...PERHAPS AS FAR WEST AS THE PORCUPINE MOUNTAINS...AND ALSO OVER THE HIGHER TERRAIN OF BARAGA AND MARQUETTE COUNTIES. THESE AREAS WILL ALSO HAVE THE ADDED BENEFIT OF NW WINDS PROVIDING UPSLOPE LIFT. NOTEABLE IS THAT SOME OF THE ENSEMBLE OUTPUT FROM THE 03Z SREF MEMBERS TRENDED HIGHER THAN PREVIOUS RUNS...INDICATING MUCH MORE SNOW...WITH A FEW MEMBERS EVEN PRINTING OUT AMOUNTS OVER 6 INCHES...WITH ISOLATED MEMBERS OVER 10 INCHES. HOWEVER...SREF OUTPUT IS SEEMING TO KEY ON LARGER SCALE FORCING IMPACTING MOST OF UPR MICHIGAN AS IT SHOWS SEVERAL INCHES OF SNOW AS FAR SOUTH AS KIMT AND EAST AS KERY. SREF MEAN SHOWS 2-4 INCHES OVER THE HIGHER TERRAIN AREAS NEAR LK SUPERIOR AND PERHAPS AN INCH OR TWO IN THAT IMT TO ERY CORRIDOR. ENOUGH EVIDENCE TO PUT MENTION OF THIS SYSTEM INTO THE HAZARDOUS WEATHER OUTLOOK AND EHWO GRAPHICS. AND THEN WE WILL WAIT TO SEE WHAT THE LATER MODEL RUNS INDICATE. SYSTEM...HOWEVER STRONG IT ENDS UP BEING...WILL LEAVE A WELL ESTABLISHED CP AIRMASS OVER THE UPPER GREAT LAKES ON SATURDAY. HOWEVER...INLAND AREAS WILL MIX TO AROUND H85 SO TEMPS WILL PUSH INTO THE 50S DEGREES THERE. RIDGE AT THE SFC MOVING OVERHEAD WILL SUPPORT LAKE BREEZES WHICH WILL PACK A PUNCH NEAR LK SUPERIOR /KEEPING TEMPS IN THE LOWER 40S/ AS WATERS OFFSHORE ARE STILL VERY COLD OR EVEN ICE COVERED IN SOME AREAS. SFC RIDGE SLOWLY SLIDES ACROSS INTO MONDAY. TEMPS SUNDAY AND MONDAY WILL MODERATE INLAND WITH READINGS WELL INTO THE 60S BY MONDAY. ONSHORE WINDS WILL CONTINUE TO KEEP GREAT LAKES SHORES MUCH COOLER. THE COOL/DRY AIRMASS AND THE RIDGE WILL ALLOW NIGHTTIME LOWS TO DIP BELOW FREEZING FOR MANY SPOTS INLAND SATURDAY NIGHT THROUGH MONDAY NIGHT. NEAR THE SHORE...READINGS WILL LIKELY STAY JUST ABOVE FREEZING. NEXT CHANCE OF RAIN...YES JUST RAIN...ARRIVES LATER MONDAY AND MORE SO INTO TUESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 740 AM EDT WED MAY 14 2014 WITH A DRY LOW-LEVEL AIR MASS IN PLACE...VFR CONDITIONS WILL PREVAIL THRU THE FCST PERIOD AT KIWD/KCMX/KSAW. A WEAKER PRES GRADIENT WILL ALLOW A LAKE BREEZE WITH NNE WINDS TO DEVELOP THIS AFTN AT KSAW. OTHERWISE...WRLY WINDS WILL PREVAIL AT KIWD AND KCMX TODAY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 527 AM EDT WED MAY 14 2014 EXPECT WESTERLY WINDS UP TO 15-25KT OVER THE W HALF OF LAKE SUPERIOR TODAY AND MOSTLY UNDER 20KT OVER THE E HALF. WINDS WILL DIMINISH TONIGHT UNDER WEAKENING PRES GRADIENT. ATTENTION THEN TURNS TO SFC LOW PRES THAT WILL LIFT N ACROSS LAKE HURON THU AND THEN TO JAMES BAY BY FRI NIGHT. TIGHTENING PRES GRADIENT WILL RESULT IN INCREASING WINDS THU...MAINLY OVER THE E HALF OF LAKE SUPERIOR. NORTHERLY WINDS THU NIGHT WILL REACH 20-30KT OVER THE E HALF. THE STRONGER WINDS OVER THE ERN LAKE WILL BEGIN TO DIMINISH LATER FRI AS THE LOW MOVES FARTHER AWAY. WINDS WILL BE MUCH LIGHTER OVER WRN LAKE SUPERIOR THU AND FRI. WEAK PRES GRADIENT OVER THE WEEKEND WILL LEAD TO WINDS UNDER 20KT. && .HYDROLOGY... ISSUED AT 527 AM EDT WED MAY 14 2014 PERIODS OF RAIN AND SNOW ARE EXPECTED TO DEVELOP THU AND CONTINUE INTO FRI. SOME LIGHT PCPN WILL LINGER ON INTO SAT. RIGHT NOW...PCPN AMOUNTS ARE EXPECTED TO BE LIGHT ENOUGH SO THAT THERE IS LITTLE IMPACT ON AREA RIVERS/STREAMS...AND SINCE NO SIGNIFICANT PCPN IS IN THE OFFING THRU EARLY NEXT WEEK...EXPECT ALL RIVERS TO HAVE AN OVERALL DOWNWARD TREND OVER THE NEXT SEVERAL DAYS. HOWEVER...THERE ARE SOME INDICATIONS THAT PCPN AMOUNTS MAY BE HEAVIER THAN CURRENTLY EXPECTED THU/FRI OVER NRN UPPER MI. IF SO...HIGHER RIVER LEVELS WILL BE SUSTAINED AND COULD RISE SOME FRI INTO SAT. THE MAIN RIVERS OF CONCERN ARE OVER THE W HALF OF UPPER MI... INCLUDING THE STURGEON RIVER AT CHASSELL AND THE MICHIGAMME RIVER AT REPUBLIC...WITCH LAKE...AND CRYSTAL FALLS. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...ROLFSON MARINE...ROLFSON HYDROLOGY...ROLFSON
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
935 AM MDT WED MAY 14 2014 .UPDATE... ISSUED AT 928 AM MDT WED MAY 14 2014 NO CHANGES MADE IN FORECAST. ALL IS ON TRACK. WEAK COLD FRONT ACROSS S CNTRL SD TO THE SRN BLACK HILLS...THENCE NW WARD INTO SE MT. THE FRONT IS MARKED BY SOME CUMULUS CONVECTION ON VSBL SAT AND BY WEAK Q-VECTOR CONVERGENCE ON NAM 700 MB. AT SURFACE A ZONE OF CONFLUENCE WITH SOME THETAE GRADIENT MARKS THE FRONT. CONVECTION IS ALSO SEEN OVER THE BLACK HILLS AND PORTIONS OF CAMPBELL COUNTY. THESE ARE FAVORED AREAS FOR SCATTERED SHOWERS AND ISOLD TSTMS TO DVLP THIS AFTN. HRRR MODEL IS BEGINNING TO PICK UP ON THIS. && .SHORT TERM...TODAY THROUGH THURSDAY NIGHT ISSUED AT 235 AM MDT WED MAY 14 2014 08Z SURFACE ANALYSIS HAD WEAK COOL FRONT/TROUGH FROM NORTH CENTRAL MT TO THE SD/ND BORDER TO NORTHERN WI. FEATURE BEING DRIVEN BY WEAK SHORTWAVE NOTED ON WATER VAPOUR OVER EASTERN MT. AREA RADARS SHOWING SOME VIRGA/SPRINKLES. PATTERN WILL REMAIN LARGELY UNCHANGED THROUGH THURSDAY WITH UPPER RIDGE OVER THE WESTERN US AND TROUGH OVER THE EASTERN HALF OF THE COUNTRY...NORTHWEST FLOW ALOFT OVER THE CWA. TODAY/TONIGHT...BOUNDARY WILL SHIFT SOUTH/WEST AND STALL OVER NORTHEAST WY INTO CENTRAL NE. EARLY MORNING VIRGA/SPRINKLES WILL QUICKLY EXIT THE CWA. DIURNAL HEATING WILL RESULT IN STEEP LAPSE RATES AGAIN THIS AFTERNOON WITH SBCAPE VALUES AROUND 100J/KG. INTERSECTION OF TERRAIN AND WEAK BOUNDARY SHOULD BE SUFFICIENT FOR LOW COVERAGE SHRA/STRAY TS THIS AFTERNOON/EVENING. ACTIVITY WILL HAVE A DIURNAL MINIMUM OVERNIGHT. BREEZY SPOTS EXPECTED TODAY WITH WEAK BOUNDARY LAYER COLD AIR ADVECTION AND 15-20KT 850MB WINDS. TEMPERATURES WILL BE NEAR GUIDANCE. THURSDAY...CYCLONIC FLOW CONTINUES WITH STEEP LOW LEVEL LAPSE RATES. RESULT WILL BE A FEW DIURNAL SHRA OVER THE WEST THURSDAY AFTERNOON. BOTH NAM/GFS NOW SHOWING A BETTER ORGANIZED SHORTWAVE DROPPING INTO THE CWA FOR THURSDAY NIGHT...SO HAVE RAISED POPS TO ACCOUNT. TEMPERATURES WILL BE NEAR GUIDANCE. && .LONG TERM...FRIDAY THROUGH TUESDAY ISSUED AT 235 AM MDT WED MAY 14 2014 NORTHWEST FLOW WILL CONTINUE THROUGH THE END OF THE WEEK WITH FAST MOVING UPPER DISTURBANCES AND A NEARLY STATIONARY FRONTAL BOUNDARY OVER THE HIGH PLAINS. THIS WILL RESULT IN NEAR DAILY CHANCES FOR SHOWERS...ESPECIALLY OVER NORTHEAST WYOMING AND FAR WESTERN SOUTH DAKOTA. SLIGHTLY BELOW AVERAGE TEMPS ARE EXPECTED THROUGH THE END OF THE WEEK. AN UPPER TROUGH/CUT OFF LOW IS PROGGED TO DEVELOP EARLY NEXT WEEK OVER THE FAR WRN CONUS. UPPER FLOW WOULD THEN BECOME MORE SWRLY WITH WARM AND MOIST AIR ADVECTING IN FROM THE S/SE. THIS WILL INCREASE CHANCES FOR THUNDERSTORMS FOR THE FIRST HALF OF NEXT WEEK ALONG WITH NEAR TO SLIGHTLY ABOVE AVERAGE TEMPERATURES. && .AVIATION...FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING ISSUED AT 452 AM MDT WED MAY 14 2014 GENERALLY ISOLATED -SHRA...AND POSSIBLY A FEW -TSRA...WILL OCCUR OVER NORTHEASTERN WYOMING AND PARTS OF WESTERN SOUTH DAKOTA AGAIN TODAY AND THIS EVENING. A FEW SNOW SHOWERS ARE ALSO POSSIBLE LATE TONIGHT ACROSS THE HIGHER BLACK HILLS. MVFR CONDITIONS ARE POSSIBLE NEAR ANY PRECIPITATION...OTHERWISE VFR CONDITIONS WILL PREVAIL. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ UPDATE...BARBER SHORT TERM...HELGESON LONG TERM...13 AVIATION...13
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1018 AM EDT WED MAY 14 2014 .SYNOPSIS... SLOW MOVING COLD FRONT OVER THE OHIO/TENNESSEE VALLEYS TODAY WILL SHIFT EAST TO THE MOUNTAINS LATE TONIGHT. A COUPLE OF WAVES OF LOW PRESSURE ALONG IT WILL HINDERS ITS EASTWARD PROGRESSION UNTIL THE LAST WAVE MOVES ACROSS THURSDAY NIGHT. COOLER AIR ASSOCIATED WITH THE UPPER TROUGH WILL ARRIVE FRIDAY INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1017 AM EDT WEDNESDAY... BACKDOOR FRONT HAS PUSHED SOUTH INTO NORTHEAST PORTIONS OF FORECAST AREA THIS MORNING...WHILE COLD FRONT APPROACHES FROM THE WEST. SATELLITE IMAGES SHOWED AREA OF LOW CLOUDS AND FOG ACROSS NORTHEAST CORNER. QUESTIONS REMAIN ON HOW FAST THE LOW CLOUDS MIX OR SCATTERED OUT THIS MORNING. ADJUST CLOUD COVER FOR THIS MORNING INTO THIS AFTERNOON. HRRR THIS MORNING GENERATES CONVECTION ALONG THE CONVERGENCE ZONE STARTING AFTER 16Z MAINLY NORTH OF HIGHWAY 460. THIS MORNINGS RNK SOUNDING INDICATED THAT PWATS HAD CLIMB TO AROUND ONE INCH AND CAPES UP TO 1500 TO 2000 J/KG ARE POSSIBLE THIS AFTERNOON. EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP THIS AFTERNOON WITH DIFFERENTIAL HEATING...LIFT AND ADD MOISTURE. ISOLATED STORMS WITH STRONG UPDRAFTS ARE POSSIBLE THIS AFTERNOON WITH THE POTENTIAL FOR DAMAGING WINDS AND HAIL. THE SWODY1 OUTLOOK HAS PLACED THE SLIGHT RISK TO OUR NORTH AND WEST FOR THIS AFTERNOON. MODIFIED TEMPERATURES AND DEW POINTS ACCORDING TO LATEST TRENDS AND HELD ON TO FORECAST HIGHS FOR THIS AFTERNOON. WILL MAKE MORE CHANGES LATER THIS AFTERNOON. AS OF 650 AM EDT WEDNESDAY... ADJUSTMENTS THIS MORNING WERE MADE TO SKY COVER...NAMELY THE NE CWA WHERE LOW CIGS AND FOG WERE ADVECTING TOWARD LYH. THINK ONCE SUN COMES UP THIS WILL HALT THE PROGRESSION TO ABOUT LYH THEN SHOULD SEE LOW CLOUDS SCATTER OUT. OTHERWISE STILL MAINLY SEEING ISOLATED SHOWERS WEST OF OUR CWA OVER ERN KY AND CENTRAL WV. PREVIOUS DISCUSSION FROM 400 AM TODAY... FORECAST CHALLENGE WILL BE COVERAGE OF SHOWERS AND STORMS TODAY BEFORE MAIN THRUST OF MOISTURE AND LIFT ARRIVE AFTER MIDNIGHT TONIGHT FROM THE SOUTHWEST. LATEST MODELS SHOWING A WEAK VORT LOBE MOVING FROM SOUTHWEST TO NORTHEAST TODAY ACROSS THE AREA...MAINLY IN THE 12Z-18Z TIME FRAME. THIS WILL HAVE SOME INFLUENCE ON PRECIP THREAT...BUT AGAIN THE OVERALL COVERAGE APPEARS TO LESSEN PER LATEST RUNS. THE MODELS ALL AGREE THAT THE NW CWA HAS THE BEST THREAT WITH LESS OF THE CHANCE OVER THE SOUTHEAST CWA. WILL FOLLOW THIS THINKING AND KEEP IN THE HIGH CHANCE IN THE GREENBRIER TO BATH/SOUTHERN SHENANDOAH VALLEY...SOUTH TOWARD ROANOKE/LYNCHBURG WITH SMALL CHANCE TO ISOLATED SOUTH OF HIGHWAY 460. EXPECTING ANOTHER WARM DAY BUT THE UPPER RIDGE SHIFTS EAST. THE RECORDS TODAY MAY NOT BE AS ATTAINABLE EXCEPT PERHAPS BLACKSBURG DEPENDING ON CLOUD COVER FROM THE CONVECTION UPSTREAM. SEE CLIMATE SECTION BELOW FOR RECORDS AT ALL OUR CLIMATE SITES. RUNNING WITH HIGHS FROM UPPER 70S-LOWER 80S NC MTNS-PORTIONS OF FAR SW VA/SE WV...TO MID 80S NEW RIVER VALLEY-ROANOKE-LYNCHBURG...AND AROUND 90 SOUTHSIDE VA INTO THE NC PIEDMONT. THERE WILL BE SOME SUBSIDENCE IN THE AFTERNOON BEHIND WEAK VORT...SO EXPECT A LULL IN THE SHOWERS AFTER 4 PM INTO THIS EVENING...BEFORE NEXT STRONG WAVE WORKS IN AHEAD OF THE FRONT OVERNIGHT. MODELS FAVOR THE SOUTHERN BLUE RIDGE GETTING THE SHOWERS AND ISOLATED STORMS AFTER MIDNIGHT AND WORKING NORTHEAST TO THE BLUE RIDGE OF VA/SE WV BY MORNING...MAYBE AS FAR EAST AS A LYH-DAN LINE. GIVEN THE HIGH PWATS RUNNING ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL THREAT OF FLASH FLOODING FROM HEAVY DOWNPOURS MAY START AS EARLY AS PREDAWN IN THE SOUTHWEST CWA. THEREFORE A FLASH FLOOD WATCH HAS BEEN ISSUED FOR THE SOUTHERN BLUE RIDGE AS FAR NORTH AS ROANOKE. THIS WILL RUN INTO LATE THURSDAY NIGHT. LOWS TONIGHT STAY MUGGY WITH UPPER 50S TO LOWER 60S MOUNTAINS...TO MID 60S ACROSS THE SOUTHSIDE OF VA INTO THE NC PIEDMONT...FOOTHILLS. && .SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... AS OF 345 AM EDT WEDNESDAY... IMPRESSIVE RAIN PRODUCING SYSTEM IS STILL SLATED TO MOVE INTO AND THROUGH THE AREA THURSDAY AND THURSDAY NIGHT. THE DRIVING FEATURES BEHIND OUR RAIN WILL BE A HIGHLY AMPLIFIED LONG WAVE TROUGH AND ASSOCIATED SURFACE COLD FRONT MAKING GRADUAL PROGRESS EASTWARD OF THE MISSISSIPPI RIVER VALLEY WITH VERY ABUNDANT MOISTURE AT THE SURFACE...LOW AND MID LEVELS OF THE ATMOSPHERE. WHILE THERE COULD BE SOME ISOLATED STRONG STORMS AHEAD OF THE MAIN FRONT...THE EXCESSIVE MOISTURE WILL QUICKLY ALLOW THE COLUMN TO SATURATE AND GREATLY REDUCE THE POTENTIAL FOR DRY AIR ALOFT TO CONTRIBUTE TO INCREASING THE CAPE VALUES. IN ADVANCE OF THE FRONT...LOW LEVEL FLOW WILL BE LONGITUDINAL AND PARALLEL TO THE MAIN UPPER TROUGH...AND THUS ALLOW FOR A SLOW PROGRESSION EASTWARD...ALLOWING PLENTY OF TIME FOR TRAINING CONVECTION TO PRODUCE HEAVY RAINFALL. THE IMPACT OF UPSLOPE ALONG THE BLUE RIDGE WILL ADD TO THIS FACTOR...AND IN THE SHORT TERM...THIS IS THE AREA OF GREATEST CONCERN. WOULD NOT BE SURPRISED AT THE END OF THE EVENT IF RAINFALL REPORTS FROM ALONG THE BLUE RIDGE TOP FOUR INCHES. GIVEN THIS AND IN COLLABORATION WITH THE GSP OFFICE...WE ARE POSTING A FLASH FLOOD WATCH FOR AREAS NEAR THE BLUE RIDGE SOUTH OF THE ROANOKE RIVER FROM MIDNIGHT TONIGHT THROUGH 600 AM FRIDAY. THIS SHOULD BE A GOOD START WHAT MAY BE ADDITIONAL WATCHES BASED UPON LATER COORDINATION WITH NEIGHBORING OFFICES AND THE LATEST GUIDANCE AS IT BECOMES AVAILABLE TODAY. FRIDAY INTO SATURDAY NIGHT...WHILE THE FRONT WILL BE TO OUR EAST...THE PARENT UPPER LOW/TROUGH WILL PROGRESS INTO AND OVER THE AREA. THIS WILL BRING AN ELEVATED COOL POOL OVER THE AREA...AND WE MAY SEE SOME ISOLATED SHOWERS ACROSS THE WESTERN PARTS OF THE AREA. ALSO...NOTABLY COOLER AIR WILL ARRIVE ACROSS THE REGION. OVERNIGHT LOWS IN THE LOWER 40S WILL BE COMMON ACROSS THE MOUNTAINS WITH MID TO UPPER 40S ACROSS THE PIEDMONT. && .LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 325 PM EDT TUESDAY... LONG WAVE TROF WILL GRADUALLY FILL AND LIFT NORTHEAST DURING THE MEDIUM RANGE AS SERIES OF SHORTWAVES ROTATE EAST THROUGH THE UPPER FLOW. THE 12Z ECMWF WAS LESS ROBUST COMPARED TO THE 00Z RUN WITH SHORTWAVE AND ASSOCIATED PRECIPITATION WITH THIS WAVE SUNDAY INTO MONDAY. IN ANY CASE...COLD AIR ALOFT IN PROXIMITY TO UPPER TROF COUPLED WITH DAYTIME SOLAR HEATING SHOULD BE SUFFICIENT TO SUPPORT DEVELOPMENT OF DIURNALLY DRIVEN SHOWERS..ESPECIALLY ACROSS THE WESTERN UPSLOPE LOCATIONS OF THE APPALACHIANS. WILL KEEP A DAILY THREAT FOR WIDELY SCATTERED TO SCATTERED SHOWERS THROUGH MUCH OF THE LONG TERM PERIOD...ALTHOUGH OVERALL TOTAL PRECIPITATION AMOUNTS SHOULD REMAIN LOCALIZED...AND LIMITED IN DURATION IN ANY PARTICULAR LOCATION. DEEPER SUBSIDENCE BUILDS IN EARLY NEXT WEEK AS THE UPPER LOW SHIFTS EAST. THE INFLUENCE OF THE SLOWLY DEPARTING UPPER TROUGH SHOULD HOLD TEMPERATURES NEAR NORMAL FOR MOST OF THE PERIOD...WITH HIGHS GENERALLY FROM THE MID 60S TO THE MID 70S. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... AS OF 730 AM EDT WEDNESDAY... ANY FOG THIS MORNING IS GOING TO BE GONE BY 13-14Z. SOME STRATUS ADVANCING TOWARD LYH MAY IMPACT THEM AT TIMES BETWEEN 12-13Z...BUT SUNSHINE WILL SCATTER THIS DECK OUT. SHOULD BE VFR THROUGH MOST OF THE PERIOD. CU SHOULD DEVELOP BY MIDDAY WITH BEST COVERAGE IN THE MTNS. SOME MID AND HIGH CLOUDS POSSIBLE AS WELL. LOOKS LIKE COVERAGE OF SHRA/TSRA WILL BE NORTH OF A LINE FROM BLF-BCB-ROA-LYH...SO HAVE VCTS IN AT TIMES THIS AFTERNOON. THE CONVECTION WEAKENS AND EXITS THIS EVENING...BEFORE THE NEXT STRONGER UPPER SHORTWAVE MOVES IN LATE FROM THE SOUTHWEST. PROBLEM SEEMS TO BE WHETHER WE GET FOG FORMATION OVERNIGHT BEFORE CLOUDS ROLL IN AND IMPEDE IT. ATTM...I AM HESISTANT TO ADD FOG BUT WOULD NOT BE SURPRISED TO SEE FOG FORM AT LWB/BCB LATE EVENING. CONFIDENCE IS LOW ON THIS. SHOWERS AND ISOLATED STORMS SHOULD MAKE IT INTO THE BLF/LWB/BCB AREAS BY THE END OF THIS TAF PERIOD...WITH MVFR VSBYS. EXPECT TO SEE BETTER THREAT FOR SHOWERS AND STORMS THURSDAY INTO THURSDAY NIGHT WITH SUB VFR LIKELY IN HEAVIER DOWNPOURS. COLD FRONT IS PROGGED TO CROSS THE MOUNTAINS THURSDAY AFTERNOON EXITING THE PIEDMONT AROUND MIDNIGHT THURSDAY NIGHT. UPPER LEVEL SYSTEM OVER THE GREAT LAKES FRIDAY WILL KEEP THE THREAT OF SHOWERS AROUND IN THE MOUNTAINS WITH UNDER VFR POSSIBLE AT BLF/LWB. SHOULD CLEAR OUT EAST OF THE MTNS AFTER FRIDAY BUT POTENTIAL FOR SHOWERS STAYS WITH US INTO THE WEEKEND AS WE STAY NEAR THE UPPER LEVEL SLOW MOVING LOW PRESSURE SYSTEM. && .HYDROLOGY... FLASH FLOOD WATCH IN EFFECT FOR THE SOUTHERN BLUE RIDGE AS FAR NORTH AS ROANOKE. MODELS AGREE THAT COPIOUS AMOUNTS OF MOISTURE WITH PWATS 2+ SD ABOVE NORMAL ALONG WITH A SLOW MOVING FRONT AND STRONG SE FLOW WILL PRODUCE TRAINING OF HEAVY RAIN. OVERALL POTENTIAL IS HIGH FOR FLASH FLOODING ALONG THE BLUE RIDGE. WILL AWAIT ANOTHER RUN OF MODELS PER COORDINATION WITH NEIGHBORING WFOS BEFORE EXPANDING THE WATCH. AS FAR AS MAIN STEM RIVERS...ENSEMBLES SUGGEST CHANCE OF MINOR FLOODING WITH POTENTIAL FOR MODERATE FLOODING ACROSS THE GREENBRIER AT ALDERSON. WILL SEE HOW THE RAIN PLAYS OUT FOR THIS. ATTM...WE ARE FORECASTING AN AVERAGE OF 1-3 INCHES OF RAIN...HIGHEST ALONG THE BLUE RIDGE WHERE UP TO 5 INCHES COULD OCCUR. && .CLIMATE... ANOTHER WARM DAY BUT RECORD HIGHS MAY BE SAFE...EXCEPT PERHAPS BLACKSBURG AS UPPER RIDGE SHIFTS EAST. SITE..........RECORDS/YEAR ROANOKE.......93/1956 LYNCHBURG.....92/1956 DANVILLE......95/1956 BLACKSBURG....86/2000 BLUEFIELD.....86/1985 LEWISBURG.....84/1985 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE THURSDAY NIGHT FOR VAZ014>017-022-032-033. NC...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE THURSDAY NIGHT FOR NCZ001>003-018-019. WV...NONE. && $$ SYNOPSIS...WP NEAR TERM...KK/WP SHORT TERM...DS LONG TERM...KK AVIATION...WP HYDROLOGY...WP CLIMATE...WP
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1102 AM MDT WED MAY 14 2014 .UPDATE... ISSUED AT 1015 AM MDT WED MAY 14 2014 UPDATED FORECAST GRIDS AND ZONES TO CUT BACK ON MORNING AND EARLY AFTERNOON CLOUD COVERAGE...AND LOWER POPS. SEEING SOME CLOUD DEVELOPMENT UPSTREAM...BUT AIR MASS IS RELATIVELY DRY. NAM IS ALREADY OVERDOING PRECIP POTENTIAL TODAY. HRRR LOOKS MORE REASONABLE...WITH JUST A FEW SPOTTY SHOWERS DEVELOPING OVER THE MTS LATE AFTERNOON. ALSO SHOWS SOME SHOWERS OVER THE ERN PLAINS...BUT GIVEN THE UPSTREAM ENVIRONMENT SOME OF THIS IS LIKELY VIRGA. SO...WILL KEEP POPS SILENT OVER THE LOWER ELEVATIONS...AND MAINTAIN LOW/SLIGHT CHANCE POPS OVER THE MTS. ROSE UPDATE ISSUED AT 713 AM MDT WED MAY 14 2014 UPDATED TO EXPIRE THE FREEZE WARNING FOR THE EASTERN PLAINS. TEMPERATURES BOTTOMED OUT IN THE UPPER 20S TO LOWER 30S EARLY THIS MORNING...AND SHOULD WARM UP QUICKLY THROUGH 9 AM. MOZLEY && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 346 AM MDT WED MAY 14 2014 CURRENTLY...BROAD NORTHWEST FLOW BEHIND A DEPARTING TROUGH OVER THE MISSOURI VALLEY HAS ENCOMPASSED SOUTHERN COLORADO. GENERALLY CLEAR SKIES ALONG WITH LIGHT NORTHWEST WINDS WILL PERSIST THROUGH SUNRISE. TEMPERATURES ARE COLD ACROSS THE LOWER ELEVATIONS. MOST LOCATIONS OVER THE PLAINS HAVE DROPPED TO NEAR FREEZING...AND SHOULD FALL ANOTHER COUPLE OF DEGREES THROUGH SUNRISE. TODAY...BROAD NORTHWEST FLOW WILL CONTINUE THROUGH TODAY WITH WEAK ENERGY DROPPING SOUTH ACROSS THE ROCKIES THIS AFTERNOON. THIS WILL LEAD TO ISOLATED TO SCATTERED SHOWER ACTIVITY OVER THE CENTRAL AND EASTERN MOUNTAINS THIS AFTERNOON. ANY SNOW THAT FALLS OUT OF THESE SHOWERS WILL BE LIGHT WITH AN INCH OR TWO POSSIBLE ON THE HIGHER PEAKS. THERE IS LESS CERTAINTY OVER THE PLAINS IN REGARDS TO SHOWER ACTIVITY. THE NAM AND NSSL WRF SOLUTIONS DO DEVELOP SCATTERED SHOWER ACTIVITY THIS AFTERNOON...WHILE THE GFS AND OTHER HIGH-RES MODEL SOLUTIONS REMAIN DRY. HAVE A FEELING GIVEN THE DRY AIR AT THE SURFACE...THAT THE PLAINS WILL SEE VIRGA WITH PERHAPS A FEW SPRINKLES...BUT NOT ENOUGH TO WARRANT POPS. TEMPERATURES WILL BEGIN THEIR WARMING TREND THIS AFTERNOON WITH 50S TO 60S FOR THE LOWER ELEVATIONS. TONIGHT...NORTHWEST FLOW WILL CONTINUE ACROSS THE REGION THROUGH THE OVERNIGHT PERIOD. EXPECT SHOWER ACTIVITY TO DISSIPATE AROUND SUNSET ACROSS THE REGION. THE EXCEPTION WILL LIKELY BE THE CENTRAL MOUNTAINS WHERE FAVORABLE OROGRAPHICS WILL HELP KEEP ISOLATED SNOW SHOWERS GOING THROUGH THE OVERNIGHT PERIOD. TEMPERATURES SHOULD BE A BIT WARMER ACROSS THE LOWER ELEVATIONS. OVERNIGHT LOWS WILL FALL INTO THE MID 30S FOR MUCH OF THE REGION...WITH NEAR FREEZING LOWS OVER EL PASO...HUERFANO AND WESTERN LAS ANIMAS COUNTY POSSIBLE. WHILE WIDESPREAD FREEZING TEMPERATURES ARE NOT ANTICIPATED...IT MAY BE WISE TO TAKE PRECAUTIONS TO PROTECT PLANTS. MOZLEY .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 346 AM MDT WED MAY 14 2014 ...PATTERN SHOWS SIGNS OF CHANGE OVER THE WEEKEND WITH BIGGER CHANGES POSSIBLE BY MIDWEEK... A DISTURBANCE DROPPING SOUTH THROUGH COLORADO FRIDAY AFTERNOON AND EVENING WILL START TO CHANGE THE PATTERN OVER SOUTHERN COLORADO. AS THE DISTURBANCE MOVES THROUGH...IT WILL BRING 40 DEGREE DEWPOINTS INTO THE EASTERN PLAINS...REPLACING 20 AND 30 DEGREE DEWPOINT AIR. THIS WILL HELP BOOST THE SHOWER AND THUNDERSTORM POTENTIAL OVER THE EASTERN MOUNTAINS AND PLAINS FRIDAY AFTERNOON AND EVENING. ON SATURDAY...THE HIGHER MOISTURE CONTENT AIR WILL RETREAT A LITTLE TO THE FAR EASTERN PLAINS...BUT THIS WILL ASSIST IN DRY LINE EVOLUTION THAT COULD ACT AS A FOCUS FOR SOME STRONG TO SEVERE CONVECTION ON SATURDAY AFTERNOON AND EVENING AND POSSIBLY MORE SO SUNDAY AFTERNOON AND EVENING. STILL NO CLEAR CONVECTIVE TRIGGER EVIDENT...BUT THE POTENTIAL FOR STRONG TO SEVERE WEATHER WILL EXIST WITH THE DRY LINE IN PLACE. RIGHT NOW...THE WAY IT LOOKS...THE DRY LINE WILL BE FLUSHED WELL EAST OF THE AREA FOR MONDAY AND TUESDAY AS A BIG PACIFIC LOW PRESSURE SYSTEM ADVANCES INTO THE GREAT BASIN. THESE 2 DAYS COULD END UP BEING HIGH FIRE DANGER DAYS OVER PARTS OF THE FORECAST AREA...DEPENDING ON THE STATUS OF THE FUELS AT THAT TIME. SOME AREAS...MAINLY ALONG AND WEST OF THE I-25 CORRIDOR...RECEIVED APPRECIABLE MOISTURE WITH THE RECENT STORM...AND A DECENT GREENUP IS UNDERWAY. HOWEVER...GENERALLY LESS PRECIPITATION FELL EAST OF THE I-25 CORRIDOR...AND THE PROGRESS OF THE GREENUP IS LESS CLEAR. WEATHER OR NOT CRITICAL FIRE WEATHER CONDITIONS WILL BE MET EARLY NEXT WEEK WILL BE LARGELY DEPENDENT ON THE STATUS OF THE GREENUP. SO...HOPEFULLY WE`LL GET SOME UPDATED FUELS INFORMATION AT THAT TIME TO CLEAR UP THE GUESS WORK. THERE ARE SOME INDICATIONS THAT THE BOUNDARY OF HIGHER DEWPOINT AIR...MORE CONDUCIVE FOR CONVECTION...COULD BE ALONG OR JUST NORTH OF THE PALMER DIVIDE MONDAY AFTERNOON AND EVENING...BUT ESPECIALLY TUESDAY AFTERNOON AND EVENING. IN FACT...TUESDAY EVENING...THE LATEST GFS HAS THIS BOUNDARY PLUNGING SOUTH THROUGH THE PLAINS NEARLY TO THE RATON RIDGE. THIS BOUNDARY COULD END UP BEING A PLAYER IN THUNDERSTORM DEVELOPMENT...STRONG TO SEVERE...BOTH MONDAY AND ESPECIALLY TUESDAY. NOT TOO SURE ABOUT THIS YET BUT SOMETHING TO KEEP AN EYE ON. THE WAY IT LOOKS RIGHT NOW...WEDNESDAY COULD BE THE DAY WE REALLY FLIP THE SWITCH TOWARD STRONGER AND WETTER CONVECTION...ESPECIALLY FOR THE EASTERN MOUNTAINS AND PLAINS. THE 00Z RUN OF THE GFS SUPPORTED THIS NOTION WHOLEHEARTEDLY...BUT NOW...WITH THE 06Z RUN...IT HAS PUSHED THE MOIST BOUNDARY BACK TO THE NORTH. ALSO...THE 00Z RUN OF THE ECMWF HOLDS THE BOUNDARY BACK MAINLY TO THE NORTH OF OUR AREA...AND HAS BEEN DOING SO CONSISTENTLY IN PREVIOUS RUNS. SO...NOT TOO SURE YET EXACTLY WHEN ALL THIS POTENTIAL MOISTURE WILL COME INTO PLAY...BUT WITH A BIG...SLOW MOVING UPPER LOW PRESSURE AREA TAKING RESIDENCE OVER THE GREAT BASIN AND SOUTHWEST STATES DURING THIS TIME FRAME...IT IS PROBABLY JUST A MATTER OF TIME. IF THINGS DON`T SET UP WEDNESDAY...THEN THURSDAY AND OR FRIDAY WOULD BE LIKELY CANDIDATES. THE PATTERN SHOULD CHANGE OVER EVENTUALLY. LW && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1058 AM MDT WED MAY 14 2014 VFR CONDITIONS ARE EXPECTED OVER THE TAF SITES THROUGH TOMORROW. A FEW SHOWERS WILL BE POSSIBLE IN AND NR THE MTS THIS AFTERNOON THROUGH EARLY EVENING...BUT ARE NOT EXPECTED TO AFFECT THE TAF SITES. A COUPLE OF WEAK DISTURBANCES IN NW FLOW ALOFT WILL MOVE THROUGH SE CO ON THU...BUT AGAIN THE MAIN IMPACT WILL BE INCREASED CLOUD COVERAGE AND SPOTTY SHOWERS MAINLY OVER THE HYR TRRN. ROSE && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ROSE SHORT TERM...MOZLEY LONG TERM...LW AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1022 AM MDT WED MAY 14 2014 .UPDATE... ISSUED AT 1015 AM MDT WED MAY 14 2014 UPDATED FORECAST GRIDS AND ZONES TO CUT BACK ON MORNING AND EARLY AFTERNOON CLOUD COVERAGE...AND LOWER POPS. SEEING SOME CLOUD DEVELOPMENT UPSTREAM...BUT AIR MASS IS RELATIVELY DRY. NAM IS ALREADY OVERDOING PRECIP POTENTIAL TODAY. HRRR LOOKS MORE REASONABLE...WITH JUST A FEW SPOTTY SHOWERS DEVELOPING OVER THE MTS LATE AFTERNOON. ALSO SHOWS SOME SHOWERS OVER THE ERN PLAINS...BUT GIVEN THE UPSTREAM ENVIRONMENT SOME OF THIS IS LIKELY VIRGA. SO...WILL KEEP POPS SILENT OVER THE LOWER ELEVATIONS...AND MAINTAIN LOW/SLIGHT CHANCE POPS OVER THE MTS. ROSE UPDATE ISSUED AT 713 AM MDT WED MAY 14 2014 UPDATED TO EXPIRE THE FREEZE WARNING FOR THE EASTERN PLAINS. TEMPERATURES BOTTOMED OUT IN THE UPPER 20S TO LOWER 30S EARLY THIS MORNING...AND SHOULD WARM UP QUICKLY THROUGH 9 AM. MOZLEY && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 346 AM MDT WED MAY 14 2014 CURRENTLY...BROAD NORTHWEST FLOW BEHIND A DEPARTING TROUGH OVER THE MISSOURI VALLEY HAS ENCOMPASSED SOUTHERN COLORADO. GENERALLY CLEAR SKIES ALONG WITH LIGHT NORTHWEST WINDS WILL PERSIST THROUGH SUNRISE. TEMPERATURES ARE COLD ACROSS THE LOWER ELEVATIONS. MOST LOCATIONS OVER THE PLAINS HAVE DROPPED TO NEAR FREEZING...AND SHOULD FALL ANOTHER COUPLE OF DEGREES THROUGH SUNRISE. TODAY...BROAD NORTHWEST FLOW WILL CONTINUE THROUGH TODAY WITH WEAK ENERGY DROPPING SOUTH ACROSS THE ROCKIES THIS AFTERNOON. THIS WILL LEAD TO ISOLATED TO SCATTERED SHOWER ACTIVITY OVER THE CENTRAL AND EASTERN MOUNTAINS THIS AFTERNOON. ANY SNOW THAT FALLS OUT OF THESE SHOWERS WILL BE LIGHT WITH AN INCH OR TWO POSSIBLE ON THE HIGHER PEAKS. THERE IS LESS CERTAINTY OVER THE PLAINS IN REGARDS TO SHOWER ACTIVITY. THE NAM AND NSSL WRF SOLUTIONS DO DEVELOP SCATTERED SHOWER ACTIVITY THIS AFTERNOON...WHILE THE GFS AND OTHER HIGH-RES MODEL SOLUTIONS REMAIN DRY. HAVE A FEELING GIVEN THE DRY AIR AT THE SURFACE...THAT THE PLAINS WILL SEE VIRGA WITH PERHAPS A FEW SPRINKLES...BUT NOT ENOUGH TO WARRANT POPS. TEMPERATURES WILL BEGIN THEIR WARMING TREND THIS AFTERNOON WITH 50S TO 60S FOR THE LOWER ELEVATIONS. TONIGHT...NORTHWEST FLOW WILL CONTINUE ACROSS THE REGION THROUGH THE OVERNIGHT PERIOD. EXPECT SHOWER ACTIVITY TO DISSIPATE AROUND SUNSET ACROSS THE REGION. THE EXCEPTION WILL LIKELY BE THE CENTRAL MOUNTAINS WHERE FAVORABLE OROGRAPHICS WILL HELP KEEP ISOLATED SNOW SHOWERS GOING THROUGH THE OVERNIGHT PERIOD. TEMPERATURES SHOULD BE A BIT WARMER ACROSS THE LOWER ELEVATIONS. OVERNIGHT LOWS WILL FALL INTO THE MID 30S FOR MUCH OF THE REGION...WITH NEAR FREEZING LOWS OVER EL PASO...HUERFANO AND WESTERN LAS ANIMAS COUNTY POSSIBLE. WHILE WIDESPREAD FREEZING TEMPERATURES ARE NOT ANTICIPATED...IT MAY BE WISE TO TAKE PRECAUTIONS TO PROTECT PLANTS. MOZLEY .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 346 AM MDT WED MAY 14 2014 ...PATTERN SHOWS SIGNS OF CHANGE OVER THE WEEKEND WITH BIGGER CHANGES POSSIBLE BY MIDWEEK... A DISTURBANCE DROPPING SOUTH THROUGH COLORADO FRIDAY AFTERNOON AND EVENING WILL START TO CHANGE THE PATTERN OVER SOUTHERN COLORADO. AS THE DISTURBANCE MOVES THROUGH...IT WILL BRING 40 DEGREE DEWPOINTS INTO THE EASTERN PLAINS...REPLACING 20 AND 30 DEGREE DEWPOINT AIR. THIS WILL HELP BOOST THE SHOWER AND THUNDERSTORM POTENTIAL OVER THE EASTERN MOUNTAINS AND PLAINS FRIDAY AFTERNOON AND EVENING. ON SATURDAY...THE HIGHER MOISTURE CONTENT AIR WILL RETREAT A LITTLE TO THE FAR EASTERN PLAINS...BUT THIS WILL ASSIST IN DRY LINE EVOLUTION THAT COULD ACT AS A FOCUS FOR SOME STRONG TO SEVERE CONVECTION ON SATURDAY AFTERNOON AND EVENING AND POSSIBLY MORE SO SUNDAY AFTERNOON AND EVENING. STILL NO CLEAR CONVECTIVE TRIGGER EVIDENT...BUT THE POTENTIAL FOR STRONG TO SEVERE WEATHER WILL EXIST WITH THE DRY LINE IN PLACE. RIGHT NOW...THE WAY IT LOOKS...THE DRY LINE WILL BE FLUSHED WELL EAST OF THE AREA FOR MONDAY AND TUESDAY AS A BIG PACIFIC LOW PRESSURE SYSTEM ADVANCES INTO THE GREAT BASIN. THESE 2 DAYS COULD END UP BEING HIGH FIRE DANGER DAYS OVER PARTS OF THE FORECAST AREA...DEPENDING ON THE STATUS OF THE FUELS AT THAT TIME. SOME AREAS...MAINLY ALONG AND WEST OF THE I-25 CORRIDOR...RECEIVED APPRECIABLE MOISTURE WITH THE RECENT STORM...AND A DECENT GREENUP IS UNDERWAY. HOWEVER...GENERALLY LESS PRECIPITATION FELL EAST OF THE I-25 CORRIDOR...AND THE PROGRESS OF THE GREENUP IS LESS CLEAR. WEATHER OR NOT CRITICAL FIRE WEATHER CONDITIONS WILL BE MET EARLY NEXT WEEK WILL BE LARGELY DEPENDENT ON THE STATUS OF THE GREENUP. SO...HOPEFULLY WE`LL GET SOME UPDATED FUELS INFORMATION AT THAT TIME TO CLEAR UP THE GUESS WORK. THERE ARE SOME INDICATIONS THAT THE BOUNDARY OF HIGHER DEWPOINT AIR...MORE CONDUCIVE FOR CONVECTION...COULD BE ALONG OR JUST NORTH OF THE PALMER DIVIDE MONDAY AFTERNOON AND EVENING...BUT ESPECIALLY TUESDAY AFTERNOON AND EVENING. IN FACT...TUESDAY EVENING...THE LATEST GFS HAS THIS BOUNDARY PLUNGING SOUTH THROUGH THE PLAINS NEARLY TO THE RATON RIDGE. THIS BOUNDARY COULD END UP BEING A PLAYER IN THUNDERSTORM DEVELOPMENT...STRONG TO SEVERE...BOTH MONDAY AND ESPECIALLY TUESDAY. NOT TOO SURE ABOUT THIS YET BUT SOMETHING TO KEEP AN EYE ON. THE WAY IT LOOKS RIGHT NOW...WEDNESDAY COULD BE THE DAY WE REALLY FLIP THE SWITCH TOWARD STRONGER AND WETTER CONVECTION...ESPECIALLY FOR THE EASTERN MOUNTAINS AND PLAINS. THE 00Z RUN OF THE GFS SUPPORTED THIS NOTION WHOLEHEARTEDLY...BUT NOW...WITH THE 06Z RUN...IT HAS PUSHED THE MOIST BOUNDARY BACK TO THE NORTH. ALSO...THE 00Z RUN OF THE ECMWF HOLDS THE BOUNDARY BACK MAINLY TO THE NORTH OF OUR AREA...AND HAS BEEN DOING SO CONSISTENTLY IN PREVIOUS RUNS. SO...NOT TOO SURE YET EXACTLY WHEN ALL THIS POTENTIAL MOISTURE WILL COME INTO PLAY...BUT WITH A BIG...SLOW MOVING UPPER LOW PRESSURE AREA TAKING RESIDENCE OVER THE GREAT BASIN AND SOUTHWEST STATES DURING THIS TIME FRAME...IT IS PROBABLY JUST A MATTER OF TIME. IF THINGS DON`T SET UP WEDNESDAY...THEN THURSDAY AND OR FRIDAY WOULD BE LIKELY CANDIDATES. THE PATTERN SHOULD CHANGE OVER EVENTUALLY. LW && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 346 AM MDT WED MAY 14 2014 VFR CONDITIONS AT ALL THREE TERMINALS THROUGH THE NEXT 24 HOURS. WINDS WILL GUST OUT OF THE NORTH AT 20 TO 25 KTS AT KCOS AND KPUB THIS AFTERNOON. A FEW SHOWERS ARE EXPECTED OVER THE MOUNTAINS THIS AFTERNOON BUT WILL NOT IMPACT ANY OF THE TERMINALS. MOZLEY && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ROSE SHORT TERM...MOZLEY LONG TERM...LW AVIATION...MOZLEY
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
537 PM EDT WED MAY 14 2014 .UPDATE 2... THE SHOWERS AND THUNDERSTORMS HAVE DISSIPATED OVER THE EASTERN AREAS OF SOUTH FLORIDA EARLY THIS EVENING...AS THE EAST COAST SEA BREEZE HAS PUSHED INLAND. THE SHOWERS AND THUNDERSTORMS OVER THE WESTERN AREAS OF SOUTH FLORIDA WILL ALSO SLOWLY DISSIPATE THROUGH THE EVENING HOURS..AS THE HEATING OF THE DAY IS LOST. SO HAVE LOWER THE POPS DOWN TO SLIGHT CHANCE OVER THE EASTERN AREAS OF SOUTH FLORIDA AND LOW CHANCE CAT FOR THE WESTERN AREAS OF SOUTH FLORIDA FOR THE EVENING HOURS. THE SHORT RANGE MODELS CONTINUE TO SHOW THE MID TO UPPER LEVEL TROUGH OF LOW PRESSURE OVER THE BAHAMA ISLANDS TO MOVE NORTHWEST AND THROUGH SOUTH FLORIDA LATE TONIGHT INTO THURSDAY MORNING. THIS WILL BRING BACK SOME DEEPER TROPICAL MOISTURE TO THE AREA STARTING LATE TONIGHT. SO WILL SHOW A UP TREND IN POPS STARTING LATE TONIGHT INTO THURSDAY MORNING OVER SOUTH FLORIDA. THE COLD FRONT OVER THE THE SOUTHEASTERN UNITED STATES WILL ALSO BE MOVING SOUTHWARD TOWARD SOUTH FLORIDA ON THURSDAY. THIS WILL KEEP THE DEEP TROPICAL MOISTURE IN PLACE FOR THURSDAY AFTERNOON. THEREFORE...THE LIKELY POPS WILL REMAIN IN PLACE OVER SOUTH FLORIDA FOR THURSDAY AFTERNOON. REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES ARE PLANNED. && .UPDATE 2...54/BNB .PREV DISCUSSION... /ISSUED 410 PM EDT WED MAY 14 2014/ UPDATE... A QUICK UPDATE TO REMOVE THE THUNDER WORDING FOR THE EAST COAST METRO AREAS FOR FRIDAY...AS THE COLD FRONT WILL BE SOUTH OF THE AREA PUSHING THE UNSTABLE AIRMASS TO THE SOUTH. REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES ARE PLANNED. && UPDATE...54/BNB PREV DISCUSSION... /ISSUED 253 PM EDT WED MAY 14 2014/ DISCUSSION... THE GLOBAL MODELS CONTINUE TO INDICATE A SURGE OF MOISTURE ENTERING THE REGION AND CONTINUING OVER NIGHT WITH RECENT SATELLITE IMAGERY INDICATING THAT TREND ALREADY UNDERWAY WITH A SURGE OF CLOUDINESS AND SHOWERS CURRENTLY ENTERING THE ATLANTIC WATERS WITH WIDESPREAD SHOWERS AND ISOLATE THUNDERSTORMS OCCURRING ACROSS THE ATLANTIC WATERS AND ACROSS PORTIONS OF THE SOUTH FLORIDA PENINSULA. BOTH THE EURO AND GFS MODELS INDICATE A SURGE OF MOISTURE ENTERING THE REGION TONIGHT WITH PWAT`S FORECAST TO BE AROUND 2 INCHES BY EARLY THURSDAY MORNING. COVERAGE OF SHOWERS IS FORECAST TO INCREASE TONIGHT AND THURSDAY WITH MORE NUMEROUS ACTIVITY FORECAST DURING THIS PERIOD. THE GLOBAL MODELS INDICATE A WEAK MID TO UPPER LEVEL RIDGE OVER THE REGION TONIGHT WITH DYNAMICAL SUPPORT FOR THUNDERSTORMS FORECAST TO BE LACKING ALTHOUGH ISOLATED ACTIVITY IS FORECAST. CURIOUSLY THE HRRR MODEL DID NOT INDICATE INCREASING CONVECTION WITH THIS DEVELOPING SCENARIO BUT IS CONSIDERED TO BE THE OUTLIER. BY THURSDAY AFTERNOON DEEP LAYERED MOISTURE IS FORECAST TO LINGER ACROSS THE REGION AHEAD OF A DEVELOPING COLD FRONT FORECAST TO BE ENTERING THE EASTERN GULF. LIKELY SHOWERS ARE INDICATED IN THE FORECAST WITH ONLY ISOLATED THUNDERSTORMS FORECAST AS DYNAMIC SUPPORT IS FORECAST TO BE LACKING. THE COLD FRONT IS FORECAST TO LINGER ACROSS THE AREA THURSDAY NIGHT INTO FRIDAY AND BEGIN EXITING THE REGION ON FRIDAY AFTERNOON WITH A COOLER AND DRIER AIR MASS FORECAST ACROSS THE AREA INTO THE UPCOMING WEEKEND. WITH REGIONAL WINDS IN THE 15 TO 20 KNOT RANGE ACROSS THE ATLANTIC WATERS EXPECTED TO CONTINUE TONIGHT...A HIGH RISK OF RIP CURRENTS IS EXPECTED TO CONTINUE ALONG THE ATLANTIC COAST BEACHES TONIGHT. MARINE... A PRE-CAUTIONARY SMALL CRAFT STATEMENT WILL LIKELY CONTINUE FOR THE LOCAL ATLANTIC WATERS OVER NIGHT WITH WINDS IN THE 15 TO 20 KNOT RANGE EXPECTED TO CONTINUE. WINDS ARE FORECAST TO BE MORE SOUTHERLY ON THURSDAY AND THEN BECOME MORE WESTERLY THURSDAY NIGHT INTO FRIDAY. SEAS ARE FORECAST TO APPROACH OR REACH ADVISORY LEVELS FOR THE ATLANTIC AND GULF WATERS LATER ON FRIDAY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 85 76 84 73 / 40 30 70 40 FORT LAUDERDALE 85 77 85 74 / 40 30 70 40 MIAMI 84 77 85 73 / 40 30 70 40 NAPLES 88 73 84 72 / 50 40 60 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR FLZ168-172- 173. AM...NONE. GM...NONE. && $$ SHORT TERM...84/AK LONG TERM....60/BD
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
410 PM EDT WED MAY 14 2014 .UPDATE... A QUICK UPDATE TO REMOVE THE THUNDER WORDING FOR THE EAST COAST METRO AREAS FOR FRIDAY...AS THE COLD FRONT WILL BE SOUTH OF THE AREA PUSHING THE UNSTABLE AIRMASS TO THE SOUTH. REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES ARE PLANNED. && .UPDATE...54/BNB .PREV DISCUSSION... /ISSUED 253 PM EDT WED MAY 14 2014/ DISCUSSION... THE GLOBAL MODELS CONTINUE TO INDICATE A SURGE OF MOISTURE ENTERING THE REGION AND CONTINUING OVER NIGHT WITH RECENT SATELLITE IMAGERY INDICATING THAT TREND ALREADY UNDERWAY WITH A SURGE OF CLOUDINESS AND SHOWERS CURRENTLY ENTERING THE ATLANTIC WATERS WITH WIDESPREAD SHOWERS AND ISOLATE THUNDERSTORMS OCCURRING ACROSS THE ATLANTIC WATERS AND ACROSS PORTIONS OF THE SOUTH FLORIDA PENINSULA. BOTH THE EURO AND GFS MODELS INDICATE A SURGE OF MOISTURE ENTERING THE REGION TONIGHT WITH PWAT`S FORECAST TO BE AROUND 2 INCHES BY EARLY THURSDAY MORNING. COVERAGE OF SHOWERS IS FORECAST TO INCREASE TONIGHT AND THURSDAY WITH MORE NUMEROUS ACTIVITY FORECAST DURING THIS PERIOD. THE GLOBAL MODELS INDICATE A WEAK MID TO UPPER LEVEL RIDGE OVER THE REGION TONIGHT WITH DYNAMICAL SUPPORT FOR THUNDERSTORMS FORECAST TO BE LACKING ALTHOUGH ISOLATED ACTIVITY IS FORECAST. CURIOUSLY THE HRRR MODEL DID NOT INDICATE INCREASING CONVECTION WITH THIS DEVELOPING SCENARIO BUT IS CONSIDERED TO BE THE OUTLIER. BY THURSDAY AFTERNOON DEEP LAYERED MOISTURE IS FORECAST TO LINGER ACROSS THE REGION AHEAD OF A DEVELOPING COLD FRONT FORECAST TO BE ENTERING THE EASTERN GULF. LIKELY SHOWERS ARE INDICATED IN THE FORECAST WITH ONLY ISOLATED THUNDERSTORMS FORECAST AS DYNAMIC SUPPORT IS FORECAST TO BE LACKING. THE COLD FRONT IS FORECAST TO LINGER ACROSS THE AREA THURSDAY NIGHT INTO FRIDAY AND BEGIN EXITING THE REGION ON FRIDAY AFTERNOON WITH A COOLER AND DRIER AIR MASS FORECAST ACROSS THE AREA INTO THE UPCOMING WEEKEND. WITH REGIONAL WINDS IN THE 15 TO 20 KNOT RANGE ACROSS THE ATLANTIC WATERS EXPECTED TO CONTINUE TONIGHT...A HIGH RISK OF RIP CURRENTS IS EXPECTED TO CONTINUE ALONG THE ATLANTIC COAST BEACHES TONIGHT. MARINE... A PRE-CAUTIONARY SMALL CRAFT STATEMENT WILL LIKELY CONTINUE FOR THE LOCAL ATLANTIC WATERS OVER NIGHT WITH WINDS IN THE 15 TO 20 KNOT RANGE EXPECTED TO CONTINUE. WINDS ARE FORECAST TO BE MORE SOUTHERLY ON THURSDAY AND THEN BECOME MORE WESTERLY THURSDAY NIGHT INTO FRIDAY. SEAS ARE FORECAST TO APPROACH OR REACH ADVISORY LEVELS FOR THE ATLANTIC AND GULF WATERS LATER ON FRIDAY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 76 84 73 82 / 60 70 40 30 FORT LAUDERDALE 77 85 74 83 / 60 70 40 30 MIAMI 77 85 73 84 / 60 70 40 30 NAPLES 73 84 72 81 / 60 60 30 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR FLZ168-172- 173. AM...NONE. GM...NONE. && $$ SHORT TERM...85/AG LONG TERM....60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
253 PM EDT WED MAY 14 2014 .DISCUSSION... THE GLOBAL MODELS CONTINUE TO INDICATE A SURGE OF MOISTURE ENTERING THE REGION AND CONTINUING OVER NIGHT WITH RECENT SATELLITE IMAGERY INDICATING THAT TREND ALREADY UNDERWAY WITH A SURGE OF CLOUDINESS AND SHOWERS CURRENTLY ENTERING THE ATLANTIC WATERS WITH WIDESPREAD SHOWERS AND ISOLATE THUNDERSTORMS OCCURRING ACROSS THE ATLANTIC WATERS AND ACROSS PORTIONS OF THE SOUTH FLORIDA PENINSULA. BOTH THE EURO AND GFS MODELS INDICATE A SURGE OF MOISTURE ENTERING THE REGION TONIGHT WITH PWAT`S FORECAST TO BE AROUND 2 INCHES BY EARLY THURSDAY MORNING. COVERAGE OF SHOWERS IS FORECAST TO INCREASE TONIGHT AND THURSDAY WITH MORE NUMEROUS ACTIVITY FORECAST DURING THIS PERIOD. THE GLOBAL MODELS INDICATE A WEAK MID TO UPPER LEVEL RIDGE OVER THE REGION TONIGHT WITH DYNAMICAL SUPPORT FOR THUNDERSTORMS FORECAST TO BE LACKING ALTHOUGH ISOLATED ACTIVITY IS FORECAST. CURIOUSLY THE HRRR MODEL DID NOT INDICATE INCREASING CONVECTION WITH THIS DEVELOPING SCENARIO BUT IS CONSIDERED TO BE THE OUTLIER. BY THURSDAY AFTERNOON DEEP LAYERED MOISTURE IS FORECAST TO LINGER ACROSS THE REGION AHEAD OF A DEVELOPING COLD FRONT FORECAST TO BE ENTERING THE EASTERN GULF. LIKELY SHOWERS ARE INDICATED IN THE FORECAST WITH ONLY ISOLATED THUNDERSTORMS FORECAST AS DYNAMIC SUPPORT IS FORECAST TO BE LACKING. THE COLD FRONT IS FORECAST TO LINGER ACROSS THE AREA THURSDAY NIGHT INTO FRIDAY AND BEGIN EXITING THE REGION ON FRIDAY AFTERNOON WITH A COOLER AND DRIER AIR MASS FORECAST ACROSS THE AREA INTO THE UPCOMING WEEKEND. WITH REGIONAL WINDS IN THE 15 TO 20 KNOT RANGE ACROSS THE ATLANTIC WATERS EXPECTED TO CONTINUE TONIGHT...A HIGH RISK OF RIP CURRENTS IS EXPECTED TO CONTINUE ALONG THE ATLANTIC COAST BEACHES TONIGHT. && .MARINE... A PRE-CAUTIONARY SMALL CRAFT STATEMENT WILL LIKELY CONTINUE FOR THE LOCAL ATLANTIC WATERS OVER NIGHT WITH WINDS IN THE 15 TO 20 KNOT RANGE EXPECTED TO CONTINUE. WINDS ARE FORECAST TO BE MORE SOUTHERLY ON THURSDAY AND THEN BECOME MORE WESTERLY THURSDAY NIGHT INTO FRIDAY. SEAS ARE FORECAST TO APPROACH OR REACH ADVISORY LEVELS FOR THE ATLANTIC AND GULF WATERS LATER ON FRIDAY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 76 84 73 82 / 60 70 40 30 FORT LAUDERDALE 77 85 74 83 / 60 70 50 40 MIAMI 77 85 73 84 / 60 70 40 40 NAPLES 73 84 72 81 / 60 60 30 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR FLZ168-172- 173. AM...NONE. GM...NONE. && $$ SHORT TERM...84/AK LONG TERM....60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
125 PM EDT WED MAY 14 2014 .AVIATION... SHOWERS ASSOCIATED WITH A SURFACE TROUGH OF LOW PRESSURE AND AN APPROACHING FRONTAL BOUNDARY WILL REMAIN LIKELY THROUGH THE 24 HR FORECAST PERIOD. IN ADDITION TO THIS ACTIVITY...A FEW STORMS CAN`T BE RULED OUT. GUSTY EAST-SOUTHEAST WINDS WILL PERSIST THROUGH THE PERIOD AND GRADUALLY VEER TO THE SOUTH-SOUTHEAST ON THURSDAY AS THE FRONT APPROACHES. PERIODS WITH SUB-VFR CONDITIONS WILL BE POSSIBLE AS SHOWERS QUICKLY MOVE OVER/AROUND THE TERMINALS. 85/AG && .PREV DISCUSSION... /ISSUED 1025 AM EDT WED MAY 14 2014/ UPDATE... MADE SOME SLIGHT ADJUSTMENTS TO THE SHORT TERM FORECAST. INITIALLY WAS GOING TO REDUCE THE POP`S ACROSS THE PENINSULA AND THE ATLANTIC WATERS. ALTHOUGH CURRENT COVERAGE OF SHOWERS HAS DIMINISHED FROM EARLIER THIS MORNING...ADDITIONAL LOW LEVEL MOISTURE CONTINUES TO ENTER THE REGION. THAT COUPLED WITH FAVORABLE UPPER LEVEL SPEED DIVERGENCE ACROSS THE REGION AND ADDITIONAL DAY TIME HEATING COULD RESULT IN MORE WIDESPREAD COVERAGE OF SHOWERS AND THUNDERSTORMS BY THIS AFTERNOON. HAVE SHIFTED MORE WIDESPREAD COVERAGE STARTING AROUND 20Z TO REFLECT THESE CONSIDERATIONS. 60 PREV DISCUSSION... /ISSUED 723 AM EDT WED MAY 14 2014/ AVIATION... SHOWERS ASSOCIATED WITH A SURFACE TROUGH OF LOW PRESSURE AND AN APPROACHING FRONTAL BOUNDARY WILL REMAIN LIKELY THROUGH THE 24 HR FORECAST PERIOD...ESPECIALLY ALONG THE EAST COAST WHERE SHOWERS CONTINUE TO DEVELOP AND SPREAD ASHORE FROM THE ATLANTIC. IN ADDITION TO THIS ACTIVITY...A FEW STORMS CAN`T BE RULED OUT. GUSTY EAST-SOUTHEAST WINDS WILL PERSIST THROUGH THE PERIOD AND GRADUALLY VEER TO THE SOUTH-SOUTHEAST ON THURSDAY AS THE FRONT APPROACHES. PERIODS WITH SUB-VFR CONDITIONS WILL BE POSSIBLE AS SHOWERS QUICKLY MOVE OVER/AROUND THE TERMINALS. 85/AG PREV DISCUSSION... /ISSUED 306 AM EDT WED MAY 14 2014/ CORRECTED MISSPELLING IN SEVENTH LINE... SHORT TERM (TODAY-FRIDAY)... MOISTURE WILL BE ON THE INCREASE ACROSS SOUTH FLORIDA THROUGH THURSDAY AS A WEAK MID/UPPER LEVEL TROUGH APPROACHES FROM THE BAHAMAS. THIS TROUGH IS ROTATING AROUND THE BASE OF A LARGE RIDGE OVER THE ATLANTIC. AS THE LOW TRACKS ACROSS SOUTH FLORIDA LATE TODAY AND THURSDAY, LAPSE RATES WILL BECOME MORE CONDUCIVE FOR THUNDERSTORM DEVELOPMENT MAINLY DURING THE AFTERNOON AND EVENING HOURS, ALTHOUGH FORECAST SOUNDINGS ONLY SHOW MODEST INSTABILITY. ADJUSTED THE POPS FOR THIS MORNING BASED ON THIS AND THE FACT THE HRRR DOES NOT SHOW MUCH OUT THROUGH 18Z THIS AFTERNOON. FORECAST SOUNDINGS ALSO INDICATE THE PWAT INCREASING TO AROUND 1.8 INCHES TODAY AND CLOSE TO TWO INCHES ON THURSDAY WHICH IS SLIGHTLY ABOVE THE AVERAGE FOR MID MAY. THAT BEING SAID, THERE WILL BE AN INCREASING THREAT FOR THUNDER BUT THE STORMS ARE NOT EXPECTED TO BE SEVERE WITH GUSTY WINDS AND FREQUENT LIGHTNING STRIKES THE PRIMARY CONCERNS ALONG WITH THE BRIEF HEAVY RAIN. OVERALL RAINFALL AMOUNTS WILL NOT BE EXCESSIVE WITH WPC QPF ONLY DEPICTING ONE-HALF TO ONE INCH TOTALS THROUGH FRIDAY MORNING. THERE HOWEVER COULD BE LOCALLY HEAVIER AMOUNTS IN ISOLATED LOCATIONS WHEREVER ECHOES MOVE OVER THE SAME AREA. THE MORE IMPRESSIVE ASPECT OF THE UPCOMING WEATHER CONDITIONS IS A LARGE SCALE MID/UPPER TROUGH THAT HAS BEEN EVOLVING ACROSS THE CENTRAL/SOUTHERN PLAINS STATES THE PAST FEW DAYS. THIS TROUGH WILL BEGIN TO SHIFT EASTWARD ON FRIDAY IN RESPONSE TO A LARGE AMPLIFYING RIDGE ALONG THE COAST OF CALIFORNIA. THE WEAK TROUGH OVER SOUTH FLORIDA WILL BEGIN TO BECOME ABSORBED BY THE UPSTREAM TROUGH AND LIFT TO THE NORTHEAST ON FRIDAY ALLOWING FOR A LITTLE BIT OF DRYING TO THE AREA AS A LATE SEASON COLD FRONT MOVES ACROSS SOUTH FLORIDA DURING THE DAY WITH PWAT FALLING TO AROUND 1.5 INCHES. THIS WILL ALSO LEAD TO A DECREASING TREND IN SHOWER AND THUNDERSTORM COVERAGE. LONG TERM (SATURDAY-TUESDAY)... THE EXTENDED PERIOD LOOKS TO BE QUITE DRY WITH FORECAST SOUNDINGS SHOWING PWAT FALLING TO AROUND ONE-HALF INCH OVER THE WEEKEND AND INTO EARLY NEXT WEEK. THESE ARE QUITE IMPRESSIVE AND IF THIS MATERIALIZES, IT WILL BE LOWEST PWAT VALUES FOR MAY ACROSS SOUTH FLORIDA SINCE 1948. AS THE TROUGH EXITS TO THE EAST, A LARGE RIDGE WILL BUILD OVER THE GULF OF MEXICO WHICH WILL KEEP SOUTH FLORIDA IN A DRY, NORTHWESTERLY UPPER AIR FLOW THROUGH TUESDAY. MARINE... AN EAST SOUTHEAST WIND WILL CONTINUE THROUGH TODAY AT 15-20 KNOTS AND THEN SLOWLY DIMINISH TONIGHT AND THURSDAY INTO THE END OF THE WEEK WHILE VEERING TO THE SOUTHEAST TONIGHT THEN TO THE SOUTH ON THURSDAY AND SOUTHWEST ON THURSDAY NIGHT. THE WIND WILL THEN SHIFT TO THE NORTH AND INCREASE AGAIN TO THE 15-20 KNOT RANGE ON FRIDAY AS A COLD FRONT MOVES ACROSS THE LOCAL WATERS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 75 86 72 83 / 50 70 50 30 FORT LAUDERDALE 76 86 74 84 / 50 70 50 40 MIAMI 76 86 74 85 / 50 70 50 40 NAPLES 73 85 72 81 / 40 50 50 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR FLZ168-172- 173. AM...NONE. GM...NONE. && $$ SHORT TERM...13/SI LONG TERM....30/KOB AVIATION...13/SI
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
107 PM CDT WED MAY 14 2014 .DISCUSSION... 324 AM CDT THE MAIN FORECAST CONCERNS CENTER AROUND THE UNSEASONABLY COOL TEMPERATURES OVER THE NEXT COUPLE OF DAYS...AS WELL AS PRECIPITATION CHANCES AS WE REMAIN IN AN UNSETTLED AND VERY COOL WEATHER PATTERN. A RATHER AMPLIFIED MID AND UPPER LEVEL FLOW PATTERN IS IN PLACE ACROSS NORTH AMERICA. THE MAIN FEATURE TO THIS FLOW PATTERN IS A LARGE UPPER LEVEL TROUGH AXIS ACROSS THE CENTRAL CONUS...WEDGED BETWEEN RIDGE AXISES OVER BOTH COASTS. THIS PATTERN CONTINUES TO SUPPORT STRONG SOUTH-SOUTHWEST FLOW ALOFT FROM THE OZARKS NORTH-NORTHEASTWARD ACROSS THE GREAT LAKES REGION. IN THE LOWER LEVELS...A RATHER STOUT BAROCLINIC ZONE RESIDES ACROSS THIS SAME REGION. FOR EXAMPLE...THE 00 UTC RAOBS MEASURED A 15 DEGREE CELSIUS TEMPERATURE DIFFERENCE BETWEEN KDVN (+1C) AND KILN (+16). THE MAIN FEATURE OF INTEREST EARLY THIS MORNING IS THE POTENT MID LEVEL SPEED MAX/IMPULSE CURRENTLY NOTED IN WATER VAPOR IMAGERY ACROSS NORTHERN TEXAS...WITHIN THE BASE OF THE LARGE SCALE CENTRAL CONUS TROUGH. THIS FEATURE WILL BEGIN TO ROUND THE BASE OF THE LARGE SCALE TROUGH LATER THIS MORNING. AS THIS OCCURS...IT IS EXPECTED TO INDUCE A LOWER LEVEL WAVE OF LOW PRESSURE ALONG THE AFOREMENTIONED BAROCLINIC ZONE NEAR THE TENNESSEE VALLEY BY EARLY THIS AFTERNOON. THIS LOW...ALONG WITH THE ASSOCIATED MID LEVEL IMPULSE...WILL LIKELY RACE NEARLY DUE NORTHWARD UP ACROSS EASTERN INDIANA OR FAR WESTERN OHIO TONIGHT...THEN ACROSS THE EASTERN GREAT LAKES ON THURSDAY. THIS TRACK LOOKS TO PLACE MUCH OF NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA WITHIN THE DEFORMATION ZONE OF THIS SYSTEM. IF THIS WERE MARCH...OR EVEN APRIL FOR THAT MATTER...THIS COULD BE A DECENT SNOW EVENT FOR PORTIONS OF THE AREA. HOWEVER WITH IT BEING MID MAY...TEMPERATURE PROFILES SHOULD REMAIN WARM ENOUGH IN THE LOWER LEVELS TO RESULT IN A COLD RAINY PERIOD ACROSS THE AREA TONIGHT. GOOD LARGE SCALE FORCING FOR ASCENT SHOULD BE COMPLEMENTED NICELY BY A STOUT BAND OF LOWER LEVEL FRONTOGENESIS WITHIN THE DEFORMATION ZONE OF THIS SYSTEM. AS SUCH...I EXPECT THERE TO BE SOME PERIODS OF MODERATE RAINFALL ACROSS PORTIONS OF NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA. RAINFALL AMOUNTS ACROSS PORTIONS OF EASTERN ILLINOIS AND NORTHWESTERN INDIANA COULD COME CLOSE TO AN INCH WITH THIS EVENT LATER TODAY AND TONIGHT. OVERALL...THE SYSTEM WILL BE A QUICK MOVER...SO RAINFALL AMOUNTS SHOULD NOT BE TOO HIGH. IN FACT...IT APPEARS THAT A DRY SLOT WILL QUICKLY PUNCH NORTHWARD ACROSS PORTIONS OF NORTHWESTERN INDIANA AND POSSIBLY FAR EASTERN ILLINOIS OVERNIGHT TONIGHT...CAUSING MOST OF THE RAIN TO END BY EARLY THURSDAY MORNING. OVERALL...IT APPEARS SCATTERED RAIN SHOWERS WILL BEGIN TO MOVE ACROSS MY FAR SOUTHEASTERLY COUNTIES DURING THE MORNING...THEN BECOME MORE WIDESPREAD ACROSS MY SOUTHEAST THIS AFTERNOON. IT APPEARS THAT NORTH CENTRAL ILLINOIS WILL BE DRY FOR MOST IF NOT ALL OF THE DAY TODAY. RAIN SHOULD BEGIN ACROSS NORTHEASTERN ILLINOIS...EITHER LATE THIS AFTERNOON OR EARLY THIS EVENING. DUE TO THE AN EARLIER ONSET OF RAIN ACROSS MY SOUTHEASTERN COUNTIES...IT WILL LIKELY BE THE COOLEST THERE TODAY...WITH SLIGHTLY WARMER CONDITIONS...NEAR THE LOW 60S ACROSS NORTH CENTRAL ILLINOIS. RAIN SHOULD OVERSPREAD MUCH OF THE AREA THIS EVENING...WITH THE HEAVIEST PRECIP LIKELY SETTING UP ACROSS EASTERN ILLINOIS AND NORTHWESTERN INDIANA. RAIN MAY LINGER A BIT ACROSS THE AREA EARLY THURSDAY MORNING BEFORE ENDING AS THE LOW SHIFTS NORTHEASTWARD ACROSS THE UPPER GREAT LAKES. THE LARGER SCALE TROUGH ACROSS THE CENTRAL PORTION OF THE COUNTRY IS EXPECTED TO DEVELOP INTO A CLOSED LOW FOR A PERIOD LATER THURSDAY INTO FRIDAY.THE CENTER OF THIS MID/UPPER LEVEL CIRCULATION IS EXPECTED TO SET UP ACROSS WISCONSIN...AND AS THIS OCCURS...NORTHERN ILLINOIS AND NORTHWESTERN ILLINOIS WILL REMAIN IN AN UNSETTLED WEATHER PATTERN...WITH CYCLONIC FLOW ALOFT SUPPORTING NUMEROUS SMALL SCALE DISTURBANCES ROTATION ACROSS THE AREA THURSDAY AFTERNOON THROUGH SATURDAY. AS A RESULT OF THIS...ADDITIONAL SCT RAIN SHOWERS ARE A GOOD BET ACROSS THE AREA. THERE IS ALSO A SMALL THREAT OF SOME DIURNAL THUNDERSTORMS THURSDAY AND FRIDAY AFTERNOON...ESPECIALLY FOR MY WESTERLY/SOUTHWESTERN AREAS. TEMPERATURES AT 500 MB ARE PROGGED TO BE AROUND -30 C WITH THE UPPER LOW OVERHEAD...AND ANY BREAKS IN THE CLOUDS COULD LEAD TO SOME STEEP LAPSE RATES ACROSS PORTIONS OF THE AREA BOTH AFTERNOON...POSSIBLY SUPPORTING SOME ISOLATED TO SCT THUNDERSTORMS. FORECAST GUIDANCE IS IN DECENT AGREEMENT INTO EARLY NEXT WEEK...SUGGESTING THAT THE UPPER LOW/TROUGH WILL LOSE ITS GRIP ON THE AREA...ALLOWING THE RIDGE ACROSS THE WEST COAST TO BUILD EASTWARD ACROSS THE CENTRAL CONUS INTO EARLY NEXT WEEK. THIS SHOULD RESULT IN A NICE WARMING TREND INTO NEXT WEEK. KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * NORTHEAST WINDS/GUSTS INCREASING THIS AFTERNOON AND OVERNIGHT...WITH SHIFT BACK TO THE NORTH NORTHWEST THURSDAY MORNING. * RAIN MOVING IN THIS AFTERNOON AND EARLY EVENING...PERSISTING OVERNIGHT. * CEILINGS LOWERING TO MVFR THIS EVENING...THEN IFR OVERNIGHT/THURSDAY MORNING. RODRIGUEZ //DISCUSSION...UPDATED 18Z... LATEST RADAR IMAGERY SHOWING GOOD AREA OF RAIN MOVING NORTH ACROSS THE AREA EARLY THIS AFTERNOON...OUT AHEAD OF DEVELOPING LOW PRESSURE OVER THE TENNESSEE VALLEY. THIS RAIN WILL CONTINUE PUSHING NORTH THIS AFTERNOON AND ARRIVING EARLIER THEN PREVIOUSLY THOUGHT...WITH SHOWERS LIKELY ENTERING THE TERMINALS AREA BY MID AFTERNOON. A STEADY INCREASE IN COVERAGE AND INTENSITY WILL OCCUR INTO THE EARLY EVENING WHILE MVFR CONDITIONS ALSO ARRIVE. A PERIOD OF RAIN WILL OCCUR TONIGHT INTO EARLY THURSDAY MORNING WITH CEILINGS ALSO LIKELY FALLING TO IFR DURING THIS TIME...BEFORE BETTER FORCING AND PRECIP EXIT THURSDAY MORNING. MVFR CEILINGS AND LINGERING LIGHT SHOWERS WILL LIKELY PERSIST BEFORE BETTER CLEARING ARRIVES BY MID DAY. DRY CONDITIONS ARE THEN EXPECTED INTO THE AFTERNOON FOR ORD...BEFORE CHANCES BEGIN INCREASING AGAIN FROM THE WEST. NORTHEAST WINDS CONTINUE TO SLOWLY BUT STEADILY INCREASE AND EXPECT THIS TO CONTINUE THIS AFTERNOON INTO THE EVENING AS THIS AREA OF LOW PRESSURE PUSHES NORTH. SPEEDS/GUSTS WILL BE THE HIGHEST OVERNIGHT INTO EARLY THURSDAY MORNING BEFORE SPEEDS DIMINISH WHILE WINDS TURN MORE NORTH NORTHWEST. A CONTINUED DIMINISHING TREND IS LIKELY INTO THURSDAY AFTERNOON AND IF WINDS BECOME LIGHT ENOUGH...A LAKE BREEZE COULD DEVELOP AND MOVE NEAR ORD LATE IN THE FORECAST PERIOD. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH CONFIDENCE WITH WIND SPEED/DIRECTION TODAY AND TONIGHT...MEDIUM CONFIDENCE WITH WIND DIRECTION THURSDAY. * HIGH CONFIDENCE OF RAIN...MEDIUM HIGH CONFIDENCE OF TIMING/DURATION. * HIGH CONFIDENCE OF MVFR CEILINGS THIS EVENING...MEDIUM CONFIDENCE IN TIMING AND FOR IFR. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...CHANCE SHRA AND MVFR. FRIDAY...SCT SHRA. NORTHERLY WINDS. AFTN LAKE BREEZE SHIFT POSSIBLE. SATURDAY...SLIGHT CHANCE SHRA. WESTERLY WINDS. SUNDAY...VFR. SHIFT TO EAST-NORTHEAST WINDS LIKELY. MONDAY...VFR. EASTERLY WINDS THROUGH THE PERIOD. TUESDAY...VFR. SLIGHT CHANCE SHRA/TSRA. SOUTHEASTERLY WINDS. MDB && .MARINE... 314 AM CDT LOW PRESSURE CONTINUES TO MOVE NORTHWARD TO HUDSON BAY WHILE A BROAD AREA OF HIGH PRESSURE EXTENDS FROM THE COLORADO ROCKIES EASTWARD TO THE WESTERN GREAT LAKES. LOW PRESSURE IS BEGINNING TO DEVELOP ACROSS THE GULF COAST STATES. THE WEAK PRESSURE GRADIENT HAS RESULTED IN A VARIETY OF WIND DIRECTIONS ACROSS THE LAKE WITH GENERALLY WEST TO NORTHWEST WINDS ACROSS THE SOUTHERN PART OF THE LAKE AND MORE VARIABLE WIND DIRECTION ACROSS THE NORTH. THE HIGH WILL SHIFT NORTHWARD DURING THE DAY WHILE THE GULF COAST LOW FURTHER DEVELOPS. THIS WILL LEAD TO A STEADIER NORTHERLY WIND ACROSS THE SOUTH WITH A MORE VARIABLE WESTERLY WIND ACROSS THE NORTH WHICH WILL TURN EAST OR NORTHEAST LATER IN THE DAY. THE GULF COAST LOW WILL LIFT INTO THE LOWER OHIO VALLEY TONIGHT AND TO LAKE HURON THURSDAY ALLOWING WINDS TO INTENSIFY ACROSS LAKE MICHIGAN TONIGHT. COLDER AIR WILL START TO FILTER IN THURSDAY MORNING AND SHOULD SUPPORT BETTER MIXING WHICH MAY LEAD TO A PERIOD OF GALES THURSDAY MORNING INTO EARLY THURSDAY AFTERNOON. THE SET UP LOOKS RATHER MARGINAL IN THAT THE COLD AIR WILL BE SLOW TO WORK IN SO MIXING MAY BE MINIMAL BEFORE WINDS START TO DIMINISH LATER IN THE AFTERNOON. WILL HOLD OFF ON A GALE WATCH FOR NOW BUT MENTION GALE POTENTIAL IN THE GLF/NSH PRODUCTS. THE LONG NORTH FETCH WILL TURN SLIGHTLY NORTHWESTERLY LATER THURSDAY WITH SEAS PEAKING DURING THE MORNING/MIDDAY HOURS. WEAK HIGH PRESSURE THEN BUILDS IN THURSDAY NIGHT AND FRIDAY ALLOWING WINDS TO DROP OFF BUT THE DIRECTION MAY BECOME QUITE VARIABLE FRIDAY. ERRATIC WIND DIRECTION WITH FAIRLY LIGHT SPEED IS EXPECTED OVER THE WEEKEND WITH THE WEAK PRESSURE GRADIENT REMAINING IN PLACE. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744- LMZ745...4 AM THURSDAY TO 10 PM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1146 AM CDT Wed May 14 2014 .DISCUSSION... ISSUED 1036 AM CDT Wed May 14 2014 Deep trof aloft associated with developing low over the Gulf Coast this morning. Plenty of moisture streaming into the region and rain is spreading across the Midwest. Though the activity is currently focused just north of the Ohio River Valley, HRRR model is persistent in continuing to develop and spread out the precipitation through the afternoon. Going forecast is doing well with temperatures almost holding steady/barely rising and PoPs increasing through the afternoon and into the evening. Not planning any updates to the forecast at this time. && .AVIATION... ISSUED 1137 AM CDT Wed May 14 2014 Developing low moving out over the next 24 hrs keeping BKN/OVC low and -ra for the forecast...mainly low MVFR with some IFR conditions possible. DEC and CMI already dropped to MVFR cigs with developing rain across the region. Expect to see the same to the NWrn terminals throughout the afternoon/evening. Time heights showing abundant moisture aloft to keep clouds in place overnight and through morning...with some breaks possible after sunrise. Have started the trend back to the MVFR/VFR break, but little confidence at this point. Tightening pressure gradient will create some gusty conditions in the overnight hours and through tomorrow morning. HJS && .PREV DISCUSSION... ISSUED 330 AM CDT Wed May 14 2014 SHORT TERM...Today through Saturday night An unsettled weather pattern looks to continue across central and southeast IL the next few days along with cool temperatures. 00Z short range models are in fair agreement next few days and models show much of CWA will see another round of showers today and tonight and heaviest over eastern/se IL where around 1 inch or more of rain expected. Early morning surface map shows a frontal boundary stretched from nw Ohio through mid KY/TN and central MS/LA. 1015 mb surface low pressure was near the LA coast. Radar mosaic shows showers se of a Danville to Charleston to Effingham line and lifting nne into east central and especially se IL. A few heavier showers near the Wabash river while thunderstorms are further se in warm sector over TN and southern KY. Cooler temps are in the upper 40s north of I-72 and lower 50s from I-72 south. Aloft a strong upper level trof was over the Great Plains with strong upper level ridges off the Atlantic and west coasts. Models shows surface low pressure over the southern MS river valley strengthening as it ejects nne along frontal boundary reaching southern Indiana by midnight tonight and into eastern lower MI by early afternoon Thu. Water vapor loop shows a tropical plume of deep moisture streaming northward from the western gulf of Mexico into IL so this could bring some heavy rains around 1 inch or more over eastern IL today into tonight. NW areas will likely stay dry this morning but see rain chances increase during the afternoon and evening. SPC keeps slight risk of severe storms se of IL today with chance of thunderstorms over far se IL near the Wabash river. Tropical plume of moisture shifts east/ne of central IL during overnight though strong upper level trof moving into IL Thu and Fri to keep good chances of rain showers around especially during the afternoon and early evening hours. Sided toward cooler highs in the mid 50s to near 60F through Friday due to abundant cloud cover and cooling 850 mb temps. Lows in the upper 30s and lower 40s Thu and Fri night and thinking Friday night to be the coolest night. Strong/large upper level trof starts to pull ne into Great Lakes region Sat so just have isolated showers possible with more peaks of sunshine and highs in the lower 60s, with a few upper 50s from I-74 ne. LONG TERM...Sunday through Wednesday Extended models shower upper level ridge shifting east into the MS river valley early next work week with below normal temperatures this weekend moderating closer to normal by middle of next week. Dry conditions looks to prevail Sunday through Monday across central/se IL. Then short waves riding over top of upper level ridge along with developing frontal boundary from central plains into central IL to bring isolated convection to mainly northern areas from Monday night through Wed. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1104 AM CDT WED MAY 14 2014 .DISCUSSION... 324 AM CDT THE MAIN FORECAST CONCERNS CENTER AROUND THE UNSEASONABLY COOL TEMPERATURES OVER THE NEXT COUPLE OF DAYS...AS WELL AS PRECIPITATION CHANCES AS WE REMAIN IN AN UNSETTLED AND VERY COOL WEATHER PATTERN. A RATHER AMPLIFIED MID AND UPPER LEVEL FLOW PATTERN IS IN PLACE ACROSS NORTH AMERICA. THE MAIN FEATURE TO THIS FLOW PATTERN IS A LARGE UPPER LEVEL TROUGH AXIS ACROSS THE CENTRAL CONUS...WEDGED BETWEEN RIDGE AXISES OVER BOTH COASTS. THIS PATTERN CONTINUES TO SUPPORT STRONG SOUTH-SOUTHWEST FLOW ALOFT FROM THE OZARKS NORTH-NORTHEASTWARD ACROSS THE GREAT LAKES REGION. IN THE LOWER LEVELS...A RATHER STOUT BAROCLINIC ZONE RESIDES ACROSS THIS SAME REGION. FOR EXAMPLE...THE 00 UTC RAOBS MEASURED A 15 DEGREE CELSIUS TEMPERATURE DIFFERENCE BETWEEN KDVN (+1C) AND KILN (+16). THE MAIN FEATURE OF INTEREST EARLY THIS MORNING IS THE POTENT MID LEVEL SPEED MAX/IMPULSE CURRENTLY NOTED IN WATER VAPOR IMAGERY ACROSS NORTHERN TEXAS...WITHIN THE BASE OF THE LARGE SCALE CENTRAL CONUS TROUGH. THIS FEATURE WILL BEGIN TO ROUND THE BASE OF THE LARGE SCALE TROUGH LATER THIS MORNING. AS THIS OCCURS...IT IS EXPECTED TO INDUCE A LOWER LEVEL WAVE OF LOW PRESSURE ALONG THE AFOREMENTIONED BAROCLINIC ZONE NEAR THE TENNESSEE VALLEY BY EARLY THIS AFTERNOON. THIS LOW...ALONG WITH THE ASSOCIATED MID LEVEL IMPULSE...WILL LIKELY RACE NEARLY DUE NORTHWARD UP ACROSS EASTERN INDIANA OR FAR WESTERN OHIO TONIGHT...THEN ACROSS THE EASTERN GREAT LAKES ON THURSDAY. THIS TRACK LOOKS TO PLACE MUCH OF NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA WITHIN THE DEFORMATION ZONE OF THIS SYSTEM. IF THIS WERE MARCH...OR EVEN APRIL FOR THAT MATTER...THIS COULD BE A DECENT SNOW EVENT FOR PORTIONS OF THE AREA. HOWEVER WITH IT BEING MID MAY...TEMPERATURE PROFILES SHOULD REMAIN WARM ENOUGH IN THE LOWER LEVELS TO RESULT IN A COLD RAINY PERIOD ACROSS THE AREA TONIGHT. GOOD LARGE SCALE FORCING FOR ASCENT SHOULD BE COMPLEMENTED NICELY BY A STOUT BAND OF LOWER LEVEL FRONTOGENESIS WITHIN THE DEFORMATION ZONE OF THIS SYSTEM. AS SUCH...I EXPECT THERE TO BE SOME PERIODS OF MODERATE RAINFALL ACROSS PORTIONS OF NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA. RAINFALL AMOUNTS ACROSS PORTIONS OF EASTERN ILLINOIS AND NORTHWESTERN INDIANA COULD COME CLOSE TO AN INCH WITH THIS EVENT LATER TODAY AND TONIGHT. OVERALL...THE SYSTEM WILL BE A QUICK MOVER...SO RAINFALL AMOUNTS SHOULD NOT BE TOO HIGH. IN FACT...IT APPEARS THAT A DRY SLOT WILL QUICKLY PUNCH NORTHWARD ACROSS PORTIONS OF NORTHWESTERN INDIANA AND POSSIBLY FAR EASTERN ILLINOIS OVERNIGHT TONIGHT...CAUSING MOST OF THE RAIN TO END BY EARLY THURSDAY MORNING. OVERALL...IT APPEARS SCATTERED RAIN SHOWERS WILL BEGIN TO MOVE ACROSS MY FAR SOUTHEASTERLY COUNTIES DURING THE MORNING...THEN BECOME MORE WIDESPREAD ACROSS MY SOUTHEAST THIS AFTERNOON. IT APPEARS THAT NORTH CENTRAL ILLINOIS WILL BE DRY FOR MOST IF NOT ALL OF THE DAY TODAY. RAIN SHOULD BEGIN ACROSS NORTHEASTERN ILLINOIS...EITHER LATE THIS AFTERNOON OR EARLY THIS EVENING. DUE TO THE AN EARLIER ONSET OF RAIN ACROSS MY SOUTHEASTERN COUNTIES...IT WILL LIKELY BE THE COOLEST THERE TODAY...WITH SLIGHTLY WARMER CONDITIONS...NEAR THE LOW 60S ACROSS NORTH CENTRAL ILLINOIS. RAIN SHOULD OVERSPREAD MUCH OF THE AREA THIS EVENING...WITH THE HEAVIEST PRECIP LIKELY SETTING UP ACROSS EASTERN ILLINOIS AND NORTHWESTERN INDIANA. RAIN MAY LINGER A BIT ACROSS THE AREA EARLY THURSDAY MORNING BEFORE ENDING AS THE LOW SHIFTS NORTHEASTWARD ACROSS THE UPPER GREAT LAKES. THE LARGER SCALE TROUGH ACROSS THE CENTRAL PORTION OF THE COUNTRY IS EXPECTED TO DEVELOP INTO A CLOSED LOW FOR A PERIOD LATER THURSDAY INTO FRIDAY.THE CENTER OF THIS MID/UPPER LEVEL CIRCULATION IS EXPECTED TO SET UP ACROSS WISCONSIN...AND AS THIS OCCURS...NORTHERN ILLINOIS AND NORTHWESTERN ILLINOIS WILL REMAIN IN AN UNSETTLED WEATHER PATTERN...WITH CYCLONIC FLOW ALOFT SUPPORTING NUMEROUS SMALL SCALE DISTURBANCES ROTATION ACROSS THE AREA THURSDAY AFTERNOON THROUGH SATURDAY. AS A RESULT OF THIS...ADDITIONAL SCT RAIN SHOWERS ARE A GOOD BET ACROSS THE AREA. THERE IS ALSO A SMALL THREAT OF SOME DIURNAL THUNDERSTORMS THURSDAY AND FRIDAY AFTERNOON...ESPECIALLY FOR MY WESTERLY/SOUTHWESTERN AREAS. TEMPERATURES AT 500 MB ARE PROGGED TO BE AROUND -30 C WITH THE UPPER LOW OVERHEAD...AND ANY BREAKS IN THE CLOUDS COULD LEAD TO SOME STEEP LAPSE RATES ACROSS PORTIONS OF THE AREA BOTH AFTERNOON...POSSIBLY SUPPORTING SOME ISOLATED TO SCT THUNDERSTORMS. FORECAST GUIDANCE IS IN DECENT AGREEMENT INTO EARLY NEXT WEEK...SUGGESTING THAT THE UPPER LOW/TROUGH WILL LOSE ITS GRIP ON THE AREA...ALLOWING THE RIDGE ACROSS THE WEST COAST TO BUILD EASTWARD ACROSS THE CENTRAL CONUS INTO EARLY NEXT WEEK. THIS SHOULD RESULT IN A NICE WARMING TREND INTO NEXT WEEK. KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * NNE STEADILY INCREASING IN SPEED THROUGH MID DAY WITH GUSTS BECOMING MORE LIKELY. * WINDS/GUSTS INCREASE MID/LATE AFTERNOON AND THROUGH THE EVENING. * RAIN SPREADS IN THIS EVENING WITH CIGS LOWERING TO MVFR LATE EVENING...THEN IFR OVERNIGHT/THURSDAY MORNING. * WINDS SHIFT TO NNW AND REMAIN GUSTY THURSDAY MORNING. THIS SHOULD BRING IMPROVEMENT TO MVFR CIGS. MDB/RODRIGUEZ //DISCUSSION...UPDATED 12Z... HIGH PRESSURE RIDGING EXTENDS ACROSS THE TERMINALS THIS MORNING BUT WILL BE SHIFTING NORTH OF THE AREA AS LOW PRESSURE DEVELOPS OVER THE GULF COAST. LIGHT NNW WINDS WILL TURN NNE THIS MORNING WITH SPEEDS GRADUALLY INCREASING. EXPECT THAT THE TERMINALS WILL SEE A RANGE OF SPEEDS AS VELOCITY INCREASES I.E. 6-9 KT INCREASING TO 9-12 KT...THROUGH THE MORNING. SOME SPORADIC GUSTS INTO THE UPPER TEENS SHOULD ALSO START TO DEVELOP EARLY THIS AFTERNOON. SPEEDS WILL LIKELY BECOME STEADIER LATER THIS AFTERNOON WITH MORE PERSISTENT GUSTS DEVELOPING AS WELL. SPEEDS WILL FURTHER INCREASE THIS EVENING AND AM CONCERNED THAT THE FORECAST MAY BE A BIT TOO CONSERVATIVE WITH SPEEDS/GUSTS BY LATE EVENING/OVERNIGHT. THE LOW WILL ADVANCE TO THE LOWER OHIO VALLEY AND THEN TO LAKE HURON THROUGH TOMORROW WHICH WILL BRING RAIN INTO THE AREA. THE NORTHEASTERLY FLOW WILL SUPPLY DRY AIR TO THE LOW LEVELS INTO THE EVENING SO THIS MAY LIMIT THE COVERAGE OF RAIN THROUGH EARLY EVENING...AS WELL AS SLOW THE LOWERING OF CIGS. GYY SHOULD SEE RAIN MOVE IN FIRST LATER THIS AFTERNOON WITH THE REMAINING SITES SEEING INCREASING COVERAGE THIS EVENING. EXPECT THAT MVFR CIGS WILL DEVELOP BY EARLY TONIGHT AS THE MORE PERSISTENT RAIN ARRIVES...WITH LOWERING TO IFR LIKELY. WINDS WILL TURN NNW THURSDAY MORNING BRINGING COOLER AND SOMEWHAT DRIER LOW LEVEL AIR WHICH SHOULD HELP CIGS IMPROVE. SPEEDS/GUSTS WILL PERSIST THROUGH THE MORNING HOWEVER...WITH 30 KT POSSIBLE. MDB //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH CONFIDENCE WITH NNE WIND AND SPEEDS. * HIGH CONFIDENCE IN SPEEDS/GUSTS INCREASING THIS AFTERNOON THROUGH THE EVENING...MEDIUM CONFIDENCE IN SPECIFIC SPEEDS. * HIGH CONFIDENCE IN RAIN MOVING IN THIS EVENING WITH LOWER CIGS. MEDIUM CONFIDENCE IN TIMING OF LOWERING TO MVFR CIGS THEN IFR CIGS. * MEDIUM-HIGH CONFIDENCE IN WINDS SHIFTING NNW THURSDAY MORNING...MEDIUM CONFIDENCE IN TIMING. LOW-MEDIUM CONFIDENCE IN TIMING OF IMPROVEMENT ABOVE IFR. MDB/RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...CHANCE SHRA AND MVFR. FRIDAY...SCT SHRA. NORTHERLY WINDS. AFTN LAKE BREEZE SHIFT POSSIBLE. SATURDAY...SLIGHT CHANCE SHRA. WESTERLY WINDS. SUNDAY...VFR. SHIFT TO EAST-NORTHEAST WINDS LIKELY. MONDAY...VFR. EASTERLY WINDS THROUGH THE PERIOD. TUESDAY...VFR. SLIGHT CHANCE SHRA/TSRA. SOUTHEASTERLY WINDS. MDB && .MARINE... 314 AM CDT LOW PRESSURE CONTINUES TO MOVE NORTHWARD TO HUDSON BAY WHILE A BROAD AREA OF HIGH PRESSURE EXTENDS FROM THE COLORADO ROCKIES EASTWARD TO THE WESTERN GREAT LAKES. LOW PRESSURE IS BEGINNING TO DEVELOP ACROSS THE GULF COAST STATES. THE WEAK PRESSURE GRADIENT HAS RESULTED IN A VARIETY OF WIND DIRECTIONS ACROSS THE LAKE WITH GENERALLY WEST TO NORTHWEST WINDS ACROSS THE SOUTHERN PART OF THE LAKE AND MORE VARIABLE WIND DIRECTION ACROSS THE NORTH. THE HIGH WILL SHIFT NORTHWARD DURING THE DAY WHILE THE GULF COAST LOW FURTHER DEVELOPS. THIS WILL LEAD TO A STEADIER NORTHERLY WIND ACROSS THE SOUTH WITH A MORE VARIABLE WESTERLY WIND ACROSS THE NORTH WHICH WILL TURN EAST OR NORTHEAST LATER IN THE DAY. THE GULF COAST LOW WILL LIFT INTO THE LOWER OHIO VALLEY TONIGHT AND TO LAKE HURON THURSDAY ALLOWING WINDS TO INTENSIFY ACROSS LAKE MICHIGAN TONIGHT. COLDER AIR WILL START TO FILTER IN THURSDAY MORNING AND SHOULD SUPPORT BETTER MIXING WHICH MAY LEAD TO A PERIOD OF GALES THURSDAY MORNING INTO EARLY THURSDAY AFTERNOON. THE SET UP LOOKS RATHER MARGINAL IN THAT THE COLD AIR WILL BE SLOW TO WORK IN SO MIXING MAY BE MINIMAL BEFORE WINDS START TO DIMINISH LATER IN THE AFTERNOON. WILL HOLD OFF ON A GALE WATCH FOR NOW BUT MENTION GALE POTENTIAL IN THE GLF/NSH PRODUCTS. THE LONG NORTH FETCH WILL TURN SLIGHTLY NORTHWESTERLY LATER THURSDAY WITH SEAS PEAKING DURING THE MORNING/MIDDAY HOURS. WEAK HIGH PRESSURE THEN BUILDS IN THURSDAY NIGHT AND FRIDAY ALLOWING WINDS TO DROP OFF BUT THE DIRECTION MAY BECOME QUITE VARIABLE FRIDAY. ERRATIC WIND DIRECTION WITH FAIRLY LIGHT SPEED IS EXPECTED OVER THE WEEKEND WITH THE WEAK PRESSURE GRADIENT REMAINING IN PLACE. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744- LMZ745...4 AM THURSDAY TO 10 PM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1041 AM CDT Wed May 14 2014 .DISCUSSION... ISSUED 1036 AM CDT Wed May 14 2014 Deep trof aloft associated with developing low over the Gulf Coast this morning. Plenty of moisture streaming into the region and rain is spreading across the Midwest. Though the activity is currently focused just north of the Ohio River Valley, HRRR model is persistent in continuing to develop and spread out the precipitation through the afternoon. Going forecast is doing well with temperatures almost holding steady/barely rising and PoPs increasing through the afternoon and into the evening. Not planning any updates to the forecast at this time. HJS && .AVIATION... ISSUED 618 AM CDT Wed May 14 2014 All sites will begin as VFR as mid and high clouds will be over the entire area this morning, in advance of the next weather system coming up from the south. Some uncertainty to the timing of the pcpn starting, but best estimate is around 18z at CMI and then spreading westward, reaching PIA around 21z. Conditions will be VFR to start, but conditions will get worse as the afternoon progresses into the evening. More steady rain will move into the area, affecting the TAFs with vis around 3-4sm and cigs 1.5kft in the east, to 2.5kft in the west. Around midnight, conditions will decrease again, dropping below MVFR to IFR conditions CMI, DEC, and BMI. PIA and SPI will see lower MVFR conditions with vis down to 3sm and cigs around 1.5kft. Winds will be northerly through the period, but increasing in speed as the gradient tightens in response to the low pressure area moving up the line into the area. Could also be some gusty winds during the evening and overnight hours as the low moves into westerly IND. Auten && .PREV DISCUSSION... ISSUED 330 AM CDT Wed May 14 2014 SHORT TERM...Today through Saturday night An unsettled weather pattern looks to continue across central and southeast IL the next few days along with cool temperatures. 00Z short range models are in fair agreement next few days and models show much of CWA will see another round of showers today and tonight and heaviest over eastern/se IL where around 1 inch or more of rain expected. Early morning surface map shows a frontal boundary stretched from nw Ohio through mid KY/TN and central MS/LA. 1015 mb surface low pressure was near the LA coast. Radar mosaic shows showers se of a Danville to Charleston to Effingham line and lifting nne into east central and especially se IL. A few heavier showers near the Wabash river while thunderstorms are further se in warm sector over TN and southern KY. Cooler temps are in the upper 40s north of I-72 and lower 50s from I-72 south. Aloft a strong upper level trof was over the Great Plains with strong upper level ridges off the Atlantic and west coasts. Models shows surface low pressure over the southern MS river valley strengthening as it ejects nne along frontal boundary reaching southern Indiana by midnight tonight and into eastern lower MI by early afternoon Thu. Water vapor loop shows a tropical plume of deep moisture streaming northward from the western gulf of Mexico into IL so this could bring some heavy rains around 1 inch or more over eastern IL today into tonight. NW areas will likely stay dry this morning but see rain chances increase during the afternoon and evening. SPC keeps slight risk of severe storms se of IL today with chance of thunderstorms over far se IL near the Wabash river. Tropical plume of moisture shifts east/ne of central IL during overnight though strong upper level trof moving into IL Thu and Fri to keep good chances of rain showers around especially during the afternoon and early evening hours. Sided toward cooler highs in the mid 50s to near 60F through Friday due to abundant cloud cover and cooling 850 mb temps. Lows in the upper 30s and lower 40s Thu and Fri night and thinking Friday night to be the coolest night. Strong/large upper level trof starts to pull ne into Great Lakes region Sat so just have isolated showers possible with more peaks of sunshine and highs in the lower 60s, with a few upper 50s from I-74 ne. LONG TERM...Sunday through Wednesday Extended models shower upper level ridge shifting east into the MS river valley early next work week with below normal temperatures this weekend moderating closer to normal by middle of next week. Dry conditions looks to prevail Sunday through Monday across central/se IL. Then short waves riding over top of upper level ridge along with developing frontal boundary from central plains into central IL to bring isolated convection to mainly northern areas from Monday night through Wed. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
208 PM EDT WED MAY 14 2014 .UPDATE... ISSUED AT 155 PM EDT WED MAY 14 2014 THE GRIDS AND ZFP HAVE BEEN UPDATED FOR TORNADO WATCH 154 THROUGH 8 PM THAT INCLUDES THE NW TWO THIRDS OF THE CWA. IN ADDITION TO THE HEAVY RAIN THREAT THAT WAS ADDED TO THE GRIDS...WE HAVE ALSO ADDED SEVERE ATTRIBUTE TO THE GRIDS ACROSS THE WATCH AREA THROUGH EVENING. THE SEVERE ATTRIBUTE WAS CONTINUED INTO THE OVERNIGHT HOURS IN ADVANCE OF THE BOUNDARY. EXTRAPOLATION OF THE STRONG CLUSTER OF CELLS MOVING FROM THE NORTHERN CUMBERLAND PLATEAU AND SOUTH CENTRAL KY NORTH AND EAST GENERALLY PUTS THE HIGHEST THREAT FOR ANY SEVERE THUNDERSTORMS ACROSS THAT AREA OVER THE NEXT COUPLE OF HOURS. HOWEVER...ADDITIONAL ISOLATED TO SCATTERED ACTIVITY SHOULD DEVELOP THROUGH EARLY THIS EVENING AND WITH WIND FIELDS SET TO STRENGTHEN SOME OF THOSE COULD BECOME SEVERE THROUGH EARLY THIS EVENING. DAMAGING WINDS AND HAIL IN ADDITION TO LOCALLY HEAVY RAIN APPEARS TO BE THE PRIMARY THREAT WITH THE STORMS ALTHOUGH A STRAY TORNADO OR TWO CANNOT BE RULED OUT. OTHERWISE... THE HOURLY GRIDS HAVE BEEN UPDATED TO ACCOUNT FOR RECENT OBSERVATION AND RADAR TRENDS. UPDATE ISSUED AT 1120 AM EDT WED MAY 14 2014 THE HOURLY GRIDS HAVE BEEN UPDATED MAINLY FOR RECENT SATELLITE...RADAR AND OBSERVATION TRENDS. MID LEVEL RIDGING LONG THE EASTERN SEABOARD WILL CONTINUE TO SHIFT SHIFT EAST THROUGH THIS EVENING AS A TROUGH OVER THE CENTRAL US GRADUALLY MOVES EAST INTO THE MS VALLEY REGION. A SHORTWAVE WITHIN THIS TROUGH WILL MOVE FROM THE SOUTHERN PLAINS TO THE MID MS VALLEY BY LATE THIS EVENING. THIS WILL LEAD TO A SFC WAVE DEVELOPING ALONG A BOUNDARY THAT HAS STALLED OUT BETWEEN THE INTERSTATE 65 AND INTERSTATE 75 CORRIDORS IN KY. AS THIS LOW TRACKS INTO WESTERN KY THIS EVENING...THIS WILL BACK THE LOW LEVEL FLOW A BIT TOWARD THE SOUTHEAST WHILE THE UPPER LEVEL WINDS WILL BE GENERALLY SOUTHERLY. THE SFC LOW SHOULD REACH NORTHEAST IN/NORTHWEST OH REGION BY DAWN ON THURSDAY AND THIS LOW WILL SEND THE BOUNDARY EAST AS A COLD FRONT INTO EASTERN KY LATE TONIGHT...BUT NOT EXIT INTO WV UNTIL AROUND MIDDAY ON THU. PW IS PROGGED TO CLIMB TO AROUND 1.5 INCHES OR HIGHER BY LATE THIS EVENING INTO THE OVERNIGHT HOURS IN THE DEEP SOUTHERLY FLOW. THESE VALUES ARE BETWEEN THE 75TH PERCENTILE AND 2 SD ABOVE NORMAL. RECENT RUNS OF THE NEAR TERM MODELS SUCH AS THE RAP...HRRR AND THE 12Z NAM SUGGEST MOSTLY JUST ISOLATED TO POSSIBLY SCATTERED COVERAGE OF CONVECTION THROUGH ABOUT SUNSET WITH THE HEATING OF THE DAY AS LI IS PROGGED TO REACH -5C OR LOWER AND CAPE TO REACH NEAR 2000 J/KG. MORE WIDESPREAD ACTIVITY IS ANTICIPATED LATER INTO THE EVENING AND INTO THE OVERNIGHT HOURS. THE SHORTWAVE WILL BEGIN TO TAKE ON MORE OF A NEGATIVE TILT AS IT APPROACHES THE OH VALLEY REGION WHICH SHOULD LEAD TO UPPER LEVEL DIFFLUENT FLOW AND DEEPER LIFT WITHIN THE DEEP MOISTURE LAYER. THE INCREASED SHEAR IN THE LATE AFTERNOON AND ESPECIALLY THE EVENING SHOULD LEAD TO MORE STORM ORGANIZATION COMPARED TO THIS AFTERNOON AND THE THREAT FOR SOME STRONG TO DAMAGING WINDS AND MARGINALLY SEVERE HAIL. ANY SUPERCELLS THAT DEVELOP...ESPECIALLY ALONG OR WEST OF I 75 AND OVER OUR NW COUNTIES WOULD HAVE THE POTENTIAL TO PRODUCE AN ISOLATED TORNADO. HOWEVER...HEAVY RAIN COULD END UP BEING THE BIGGEST THREAT. WITH THE PW FORECAST TO BE AS HIGH AS IT IS...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE. THE THREAT WILL LINGER IN EASTERN LOCATIONS UNTIL THE FRONT MOVES INTO WV. THE LOCALLY HEAVY RAIN THREAT HAS BEEN ADDED TO THE GRIDS AND THE HWO HAS BEEN UPDATED ACCORDINGLY. UPDATE ISSUED AT 639 AM EDT WED MAY 14 2014 A FEW SHOWERS HAVE DEVELOPING AND ARE MOVING NORTH NEAR THE I-64 CORRIDOR. THESE SHOULD LIFT NORTH OVER THE NEXT FEW HOURS. OTHERWISE...LOOKS LIKE A FAIRLY QUIET START TO THE DAY IN THE WAKE OF THIS MORNINGS SHOWER ACTIVITY. HRRR AND RAP REALLY TARGET THE WESTERN COUNTIES IN THE FORECAST AREA THIS AFTERNOON. BASED ON RADAR TRENDS THIS SEEMS REASONABLE...BUT AS WE SAW YESTERDAY...IF STORMS DEVELOP...OUTFLOW BOUNDARIES MAY PUSH THINGS FURTHER EAST BY LATE IN THE DAY. NO SIGNIFICANT UPDATE PLANNED THIS MORNING EXCEPT TO ADJUST TEMPERATURES FOR LATEST TRENDS. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 314 AM EDT WED MAY 14 2014 PRESENTLY...A POTENT SHORTWAVE TROUGH IS PUSHING ITS WAVE EAST ACROSS WEST TEXAS WITH A SFC FRONTAL BOUNDARY STRETCHING FROM NORTHWEST INDIANA...SOUTHWARD INTO SOUTHERN ILLINOIS...AND INTO EASTERN TEXAS. THIS FRONTAL BOUNDARY WILL SERVE AS THE FOCUS FOR AN AREA OF LOW PRESSURE TO DEVELOP THIS AFTERNOON AND EVENING AS THE MID LEVEL TROUGH PUSHES INTO THE LOWER MISSISSIPPI RIVER VALLEY. THIS SURFACE LOW WILL TRACK NORTHEAST FROM WESTERN KENTUCKY LATE TODAY...INTO THE SOUTHERN GREAT LAKES BY THURSDAY MORNING. SOUTHERLY FLOW WILL CONTINUE TO PUMP MOIST SFC CONDITIONS INTO EASTERN KENTUCKY THROUGH THE DAY. AS THE LOW APPROACHES FROM THE WEST...SHOWERS AND STORMS WILL RAMP UP THROUGH THE DAY. BASED ON LATEST SATELLITE/RADAR...LOOKS LIKE A CLUSTER OF STORMS WILL MOVE ACROSS CENTRAL KENTUCKY THIS MORNING. THIS COULD SEND SOME OUTFLOW BOUNDARIES TO THE EAST INTO EASTERN KENTUCKY AND SET THE STAGE FOR STORM DEVELOPMENT LATER TODAY. SHEAR IS NOT FANTASTIC...BUT IT LOOKS LIKE INSTABILITY SHOULD BE FAIRLY GOOD...SUPPORTING THE THREAT FOR SEVERE STORMS. IN FACT...NEARLY ALL OF EASTERN KENTUCKY RESIDES IN A SLIGHT RISK OF SEVERE THUNDERSTORMS THROUGH THE DAY. MAIN THREATS APPEAR TO BE DAMAGING WINDS...BUT CANNOT RULE OUT A FEW ROTATING SUPERCELLS...ESPECIALLY TOWARDS THE I-75 CORRIDOR...AND THUS AN ISOLATED TORNADO WOULD ALSO BE POSSIBLE. GIVEN WET BULB FREEZING HEIGHTS AROUND 10KFT...SOME HAIL WILL ALSO BE POSSIBLE WITH THE STRONGER CELLS. SEEMS CONDITIONS ARE TRENDING TOWARDS SUPPORTING A BETTER THREAT OF SEVERE STORMS TODAY. AS THE SFC LOW TRACKS NORTHEAST TONIGHT...THE FRONTAL BOUNDARY WILL FINALLY BE ON THE MOVE AND TRACK EAST INTO EASTERN KENTUCKY. WITH GOOD CONVERGENCE AND FORCING ANTICIPATED...WE SHOULD SEE WIDESPREAD SHOWERS AND STORMS THROUGH A GOOD PORTION OF THE NIGHT. A RISK OF A FEW SEVERE STORMS COULD CONTINUE WELL INTO THE NIGHT UNTIL THE FRONTAL BOUNDARY PUSHES ON THROUGH. SHOWERS AND STORMS WILL WIND DOWN INTO THE MIDDAY HOURS ON THURSDAY AS THE FRONT EXITS TO THE EAST. THUS...BY MID TO LATE AFTERNOON...DRY WEATHER SHOULD RETURN. MILD AND HUMID CONDITIONS WILL CONTINUE THROUGH TODAY. WITH THE PASSAGE OF THE COLD FRONT TONIGHT AND THURSDAY...MUCH COOLER WEATHER WILL RETURN THROUGH THE DAY THURSDAY WITH THE HIGHER HUMIDITY ALSO EXITING. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 130 PM EDT WED MAY 14 2014 AT THE BEGINNING OF THE LONG TERM FORECAST PERIOD A LARGE UPPER LOW WILL BE OVER THE WESTERN GREAT LAKES WITH DEEP TROUGHING EXTENDING SOUTH INTO THE GULF OF MEXICO. THIS WILL RESULT IN WELL BELOW NORMAL TEMPERATURES FOR THE START OF THE LONG TERM FORECAST. A SHORT WAVE TROUGH SWINGING THROUGH THE OH VALLEY WILL KEEP A PRECIPITATION THREAT OVER OUR AREA FOR THE BEGINNING OF THE FORECAST PERIOD. THE UPPER LOW WILL PULL INTO CANADA AS WE MOVE INTO THE WEEKEND...AND HEIGHTS WILL RISE ACROSS THE OH VALLEY...WITH A WARMING TREND FOR LATE IN THE WEEKEND AND INTO NEXT WEEK. UPPER LEVEL RIDGING WILL BUILD OVER THE SOUTH CENTRAL TO SOUTHEAST U.S. NEXT WEEK. THE CHANCE FOR PRECIPITATION NEXT WEEK WILL DEPEND ON WHERE THE AXIS OF THIS RIDGE BECOMES ESTABLISHED. IF THE PRIMARY RIDGE REMAINS TO OUR WEST THE CHANCE FOR PRECIPITATION WILL BE GREATER AS WE REMAIN IN GENERAL NORTHWEST FLOW. HOWEVER IF THE RIDGE AXIS IS FURTHER EAST WE WILL BE DRIER AND WARMER. AT THIS TIME THE CONSENSUS BLENDED MODEL LOAD SHOULD BE A GOOD STARTING POINT FORECAST TO COVER THIS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 155 PM EDT WED MAY 14 2014 AN APPROACHING COLD FRONT AND SHARP MID LEVEL WAVE WILL BE THE FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT ACROSS EASTERN KENTUCKY TODAY AND TONIGHT. THUNDERSTORM ACTIVITY WILL INITIALLY MOVE CLOSE TO SME...AND SHOULD EVENTUALLY AFFECT LOZ...JKL AND SJS MAINLY AFTER 0Z. ISOLATE ACTIVITY IS POSSIBLE IN ALL AREAS THROUGH 0Z AND LATER SO HAVE VCTS TO START THE PERIOD AT LOZ...JKL AND SJS. ANY LOCATION THAT TAKES A DIRECT HIT FROM A STORM COULD HAVE IFR OR LOWER VIS AND OR CIGS BRIEFLY. LATER ON TONIGHT AS THE FRONT MOVES IN AND THE ATMOSPHERE SATURATES...SOME MVFR AND IFR CIGS AND VISBYS ARE POSSIBLE...GENERALLY AFTER 3Z. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...KAS LONG TERM...SBH AVIATION...JP
AREA FORECAST DISCUSSION
NWS JACKSON KY
130 PM EDT WED MAY 14 2014 .UPDATE... ISSUED AT 1120 AM EDT WED MAY 14 2014 THE HOURLY GRIDS HAVE BEEN UPDATED MAINLY FOR RECENT SATELLITE...RADAR AND OBSERVATION TRENDS. MID LEVEL RIDGING LONG THE EASTERN SEABOARD WILL CONTINUE TO SHIFT SHIFT EAST THROUGH THIS EVENING AS A TROUGH OVER THE CENTRAL US GRADUALLY MOVES EAST INTO THE MS VALLEY REGION. A SHORTWAVE WITHIN THIS TROUGH WILL MOVE FROM THE SOUTHERN PLAINS TO THE MID MS VALLEY BY LATE THIS EVENING. THIS WILL LEAD TO A SFC WAVE DEVELOPING ALONG A BOUNDARY THAT HAS STALLED OUT BETWEEN THE INTERSTATE 65 AND INTERSTATE 75 CORRIDORS IN KY. AS THIS LOW TRACKS INTO WESTERN KY THIS EVENING...THIS WILL BACK THE LOW LEVEL FLOW A BIT TOWARD THE SOUTHEAST WHILE THE UPPER LEVEL WINDS WILL BE GENERALLY SOUTHERLY. THE SFC LOW SHOULD REACH NORTHEAST IN/NORTHWEST OH REGION BY DAWN ON THURSDAY AND THIS LOW WILL SEND THE BOUNDARY EAST AS A COLD FRONT INTO EASTERN KY LATE TONIGHT...BUT NOT EXIT INTO WV UNTIL AROUND MIDDAY ON THU. PW IS PROGGED TO CLIMB TO AROUND 1.5 INCHES OR HIGHER BY LATE THIS EVENING INTO THE OVERNIGHT HOURS IN THE DEEP SOUTHERLY FLOW. THESE VALUES ARE BETWEEN THE 75TH PERCENTILE AND 2 SD ABOVE NORMAL. RECENT RUNS OF THE NEAR TERM MODELS SUCH AS THE RAP...HRRR AND THE 12Z NAM SUGGEST MOSTLY JUST ISOLATED TO POSSIBLY SCATTERED COVERAGE OF CONVECTION THROUGH ABOUT SUNSET WITH THE HEATING OF THE DAY AS LI IS PROGGED TO REACH -5C OR LOWER AND CAPE TO REACH NEAR 2000 J/KG. MORE WIDESPREAD ACTIVITY IS ANTICIPATED LATER INTO THE EVENING AND INTO THE OVERNIGHT HOURS. THE SHORTWAVE WILL BEGIN TO TAKE ON MORE OF A NEGATIVE TILT AS IT APPROACHES THE OH VALLEY REGION WHICH SHOULD LEAD TO UPPER LEVEL DIFFLUENT FLOW AND DEEPER LIFT WITHIN THE DEEP MOISTURE LAYER. THE INCREASED SHEAR IN THE LATE AFTERNOON AND ESPECIALLY THE EVENING SHOULD LEAD TO MORE STORM ORGANIZATION COMPARED TO THIS AFTERNOON AND THE THREAT FOR SOME STRONG TO DAMAGING WINDS AND MARGINALLY SEVERE HAIL. ANY SUPERCELLS THAT DEVELOP...ESPECIALLY ALONG OR WEST OF I 75 AND OVER OUR NW COUNTIES WOULD HAVE THE POTENTIAL TO PRODUCE AN ISOLATED TORNADO. HOWEVER...HEAVY RAIN COULD END UP BEING THE BIGGEST THREAT. WITH THE PW FORECAST TO BE AS HIGH AS IT IS...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE. THE THREAT WILL LINGER IN EASTERN LOCATIONS UNTIL THE FRONT MOVES INTO WV. THE LOCALLY HEAVY RAIN THREAT HAS BEEN ADDED TO THE GRIDS AND THE HWO HAS BEEN UPDATED ACCORDINGLY. UPDATE ISSUED AT 639 AM EDT WED MAY 14 2014 A FEW SHOWERS HAVE DEVELOPING AND ARE MOVING NORTH NEAR THE I-64 CORRIDOR. THESE SHOULD LIFT NORTH OVER THE NEXT FEW HOURS. OTHERWISE...LOOKS LIKE A FAIRLY QUIET START TO THE DAY IN THE WAKE OF THIS MORNINGS SHOWER ACTIVITY. HRRR AND RAP REALLY TARGET THE WESTERN COUNTIES IN THE FORECAST AREA THIS AFTERNOON. BASED ON RADAR TRENDS THIS SEEMS REASONABLE...BUT AS WE SAW YESTERDAY...IF STORMS DEVELOP...OUTFLOW BOUNDARIES MAY PUSH THINGS FURTHER EAST BY LATE IN THE DAY. NO SIGNIFICANT UPDATE PLANNED THIS MORNING EXCEPT TO ADJUST TEMPERATURES FOR LATEST TRENDS. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 314 AM EDT WED MAY 14 2014 PRESENTLY...A POTENT SHORTWAVE TROUGH IS PUSHING ITS WAVE EAST ACROSS WEST TEXAS WITH A SFC FRONTAL BOUNDARY STRETCHING FROM NORTHWEST INDIANA...SOUTHWARD INTO SOUTHERN ILLINOIS...AND INTO EASTERN TEXAS. THIS FRONTAL BOUNDARY WILL SERVE AS THE FOCUS FOR AN AREA OF LOW PRESSURE TO DEVELOP THIS AFTERNOON AND EVENING AS THE MID LEVEL TROUGH PUSHES INTO THE LOWER MISSISSIPPI RIVER VALLEY. THIS SURFACE LOW WILL TRACK NORTHEAST FROM WESTERN KENTUCKY LATE TODAY...INTO THE SOUTHERN GREAT LAKES BY THURSDAY MORNING. SOUTHERLY FLOW WILL CONTINUE TO PUMP MOIST SFC CONDITIONS INTO EASTERN KENTUCKY THROUGH THE DAY. AS THE LOW APPROACHES FROM THE WEST...SHOWERS AND STORMS WILL RAMP UP THROUGH THE DAY. BASED ON LATEST SATELLITE/RADAR...LOOKS LIKE A CLUSTER OF STORMS WILL MOVE ACROSS CENTRAL KENTUCKY THIS MORNING. THIS COULD SEND SOME OUTFLOW BOUNDARIES TO THE EAST INTO EASTERN KENTUCKY AND SET THE STAGE FOR STORM DEVELOPMENT LATER TODAY. SHEAR IS NOT FANTASTIC...BUT IT LOOKS LIKE INSTABILITY SHOULD BE FAIRLY GOOD...SUPPORTING THE THREAT FOR SEVERE STORMS. IN FACT...NEARLY ALL OF EASTERN KENTUCKY RESIDES IN A SLIGHT RISK OF SEVERE THUNDERSTORMS THROUGH THE DAY. MAIN THREATS APPEAR TO BE DAMAGING WINDS...BUT CANNOT RULE OUT A FEW ROTATING SUPERCELLS...ESPECIALLY TOWARDS THE I-75 CORRIDOR...AND THUS AN ISOLATED TORNADO WOULD ALSO BE POSSIBLE. GIVEN WET BULB FREEZING HEIGHTS AROUND 10KFT...SOME HAIL WILL ALSO BE POSSIBLE WITH THE STRONGER CELLS. SEEMS CONDITIONS ARE TRENDING TOWARDS SUPPORTING A BETTER THREAT OF SEVERE STORMS TODAY. AS THE SFC LOW TRACKS NORTHEAST TONIGHT...THE FRONTAL BOUNDARY WILL FINALLY BE ON THE MOVE AND TRACK EAST INTO EASTERN KENTUCKY. WITH GOOD CONVERGENCE AND FORCING ANTICIPATED...WE SHOULD SEE WIDESPREAD SHOWERS AND STORMS THROUGH A GOOD PORTION OF THE NIGHT. A RISK OF A FEW SEVERE STORMS COULD CONTINUE WELL INTO THE NIGHT UNTIL THE FRONTAL BOUNDARY PUSHES ON THROUGH. SHOWERS AND STORMS WILL WIND DOWN INTO THE MIDDAY HOURS ON THURSDAY AS THE FRONT EXITS TO THE EAST. THUS...BY MID TO LATE AFTERNOON...DRY WEATHER SHOULD RETURN. MILD AND HUMID CONDITIONS WILL CONTINUE THROUGH TODAY. WITH THE PASSAGE OF THE COLD FRONT TONIGHT AND THURSDAY...MUCH COOLER WEATHER WILL RETURN THROUGH THE DAY THURSDAY WITH THE HIGHER HUMIDITY ALSO EXITING. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 130 PM EDT WED MAY 14 2014 AT THE BEGINNING OF THE LONG TERM FORECAST PERIOD A LARGE UPPER LOW WILL BE OVER THE WESTERN GREAT LAKES WITH DEEP TROUGHING EXTENDING SOUTH INTO THE GULF OF MEXICO. THIS WILL RESULT IN WELL BELOW NORMAL TEMPERATURES FOR THE START OF THE LONG TERM FORECAST. A SHORT WAVE TROUGH SWINGING THROUGH THE OH VALLEY WILL KEEP A PRECIPITATION THREAT OVER OUR AREA FOR THE BEGINNING OF THE FORECAST PERIOD. THE UPPER LOW WILL PULL INTO CANADA AS WE MOVE INTO THE WEEKEND...AND HEIGHTS WILL RISE ACROSS THE OH VALLEY...WITH A WARMING TREND FOR LATE IN THE WEEKEND AND INTO NEXT WEEK. UPPER LEVEL RIDGING WILL BUILD OVER THE SOUTH CENTRAL TO SOUTHEAST U.S. NEXT WEEK. THE CHANCE FOR PRECIPITATION NEXT WEEK WILL DEPEND ON WHERE THE AXIS OF THIS RIDGE BECOMES ESTABLISHED. IF THE PRIMARY RIDGE REMAINS TO OUR WEST THE CHANCE FOR PRECIPITATION WILL BE GREATER AS WE REMAIN IN GENERAL NORTHWEST FLOW. HOWEVER IF THE RIDGE AXIS IS FURTHER EAST WE WILL BE DRIER AND WARMER. AT THIS TIME THE CONSENSUS BLENDED MODEL LOAD SHOULD BE A GOOD STARTING POINT FORECAST TO COVER THIS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 639 AM EDT WED MAY 14 2014 AN APPROACHING COLD FRONT WILL BE THE FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT ACROSS EASTERN KENTUCKY TODAY AND TONIGHT. THUNDERSTORM ACTIVITY MAY BE SLOW TO MOVE INTO THE TAF SITES TODAY...BUT SHOULD EVENTUALLY SPREAD INTO FAR EASTERN KENTUCKY BY LATE IN THE DAY OR THIS EVENING. GOING TO KEEP EVERYTHING VFR INTO TONIGHT...ALTHOUGH WE SHOULD SEE SOME LOWER CIGS AND VISBYS WITH THE THUNDERSTORMS LATE TODAY AND TONIGHT. OF COURSE ANTICIPATING THUNDERSTORM DEVELOPMENT BEYOND 9 TO 12 HOURS IS HARD TO DO...SO WILL REMAIN GENERIC WITH THUNDERSTORM MENTION IN THE TAFS UNTIL WE CAN GET SOME BETTER CONFIDENCE ON WHEN AND WHERE STORMS MAY DEVELOP. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...KAS LONG TERM...SBH AVIATION...KAS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1219 PM EDT WED MAY 14 2014 .SYNOPSIS... HIGH PRESSURE WILL MOVE EAST OF THE REGION TODAY AS A WARM FRONT LIFTS NORTHWARD ACROSS THE REGION. LOW PRESSURE AND A COLD FRONT WILL MOVE VERY SLOWLY TOWARD REGION FROM THE QUEBEC PROVINCE LATE IN THE WEEK WHILE HIGH PRESSURE HOLDS ACROSS THE WESTERN ATLANTIC. && .NEAR TERM /THROUGH TONIGHT/... UPDATE...ADJUSTED POPS AND TEMPS TO REFLECT CURRENT TRENDS. TEMPERATURES WILL NOT FALL MUCH TONIGHT WITH WARM AND MOIST AIR ADVECTING INTO THE AREA. THIS WILL CAUSE AREAS OF DRIZZLE AND FOG LATER TONIGHT INTO EARLY THURSDAY MORNING...MOSTLY FOR THE COAST AND UPSLOPE AREAS IN SOUTHERN PISCATAQUIS AND NORTHERN PENOBSCOT. LOW MORNING CLOUDS WILL GIVE WAY TO SOME SUNSHINE AND THE WARMEST DAY OF THE YEAR FOR MOST LOCATIONS. TEMPERATURES WILL REACH THE 70S INLAND WITH UPPER 70S IN THE ALLAGASH. THE COAST WILL BE MUCH COOLER WITH AN ONSHORE FLOW AND HIGHS IN THE LOW 60S. PREVIOUS DISCUSSION LATEST RADAR SHOWED A BAND OF SHOWERS IN ASSOCIATION WITH THE APPROACHING 850 MB WARM FRONT WORKING EAST FROM QUEBEC. LATEST MESOSCALE GUIDANCE INCLUDING THE HRRR AND RAP SHOW THIS BAND WILL MOVE NORTHEAST ACROSS THE REGION THIS MORNING. THE BEST CHANCE FOR SHOWERS WILL BE ACROSS NORTHERN AREAS THIS MORNING WITH LESSER CHANCES DOWNEAST. THIS BAND OF SHOWERS WILL MOVE EAST INTO NEW BRUNSWICK BY LATE MORNING OR EARLY AFTERNOON WITH MOSTLY CLOUDY/PARTLY SUNNY SKIES IN ITS WAKE. HIGHS TODAY WILL BE DEPENDENT ON HOW MUCH SUN WE SEE LATER TODAY. THE BEST CHANCES WILL BE BACK ACROSS WESTERN AREAS LATER THIS AFTERNOON AND THIS MAY ALLOW TEMPERATURES TO RISE WELL INTO THE 60S. IT WILL BE COOLER ACROSS DOWNEAST MAINE ESPECIALLY THE IMMEDIATE COAST WHERE A COOLER ONSHORE FLOW WILL KEEP TEMPERATURES ONLY IN THE LOW TO MID 50S. THE 500MB RIDGE AXIS WILL MOVE EAST OF THE REGION TONIGHT. SOUTH WINDS AROUND THE HIGH TO OUR EAST WILL BRING THE POTENTIAL FOR LOW CLOUDS AND FOG ESPECIALLY ACROSS DOWNEAST MAINE. BUFKIT SOUNDINGS CERTAINLY APPEAR FAVORABLE FOR LOW STRATUS DEVELOPMENT DOWNEAST LATER TONIGHT. OTHER THAN SOME PATCHY LIGHT DRIZZLE DOWNEAST IT SHOULD REMAIN DRY TONIGHT. LOWS TONIGHT WILL BE MAINLY IN THE MID TO UPPER 40S WITH UPPER 40S TO LOW 50S DOWNEAST. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... HIGH AMPLITUDE UPPER RIDGE OVR THE WRN ATLC/ERN US/ERN CAN W/ DIGGING UPPER TROF ACROSS THE WRN GRT LAKES AND MISSISSIPPI RVR VLY AT THE START OF THE SHORT TERM PD THU AM... AT THE SFC...LOW PRES OVR THE WRN OH VLY/SRN GRT LAKES REGION W/ BROAD SRLY FLOW ACROSS OUR REGION W/ SFC HIGH PRES JUST E OF OUR AREA. STRONG UPPER RIDGE ACROSS THE REGION WILL KEEP SYSTEM TO OUR W INITIALLY AT BAY W/ DRY BUT MILD BUT RATHER HUMID CONDS ACROSS OUR REGION THRU FRI. TEMPS WILL BE ON THE TRICKY SIDE AS OVERALL UPPER HGTS AND SFC-1000 THICKNESS SUGGESTS TEMPS QUITE WARM DURING THIS PD BUT SRLY FLOW OFF THE COLD ATLC WATERS WILL LIKELY HAVE SOME MODERATING INFLUENCES ON OVERALL TEMPS SO HAVE GONE CONSERVATIVE FOR NOW. FOG MAY ALSO BE AN ISSUE SPCLY ACROSS SRN AREAS W/ THE WARM AND HUMID SRLY FLOW OFF THE COLD ATLC WATERS... OVERALL HOWEVER...A VERY SPRING-LIKE PTRN THU/FRI W/ NO MAJOR ISSUES EXPECTED. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE STRONG UPPER RIDGE WHICH PROTECTED OUR REGION THRU FRI W/ DRY AND MILD CONDS WILL GRADUALLY SHIFT EWRD ALLOWING THE WX SYSTEM W OF THE AREA TO GRADUALLY BECOME MORE OF A FACTOR FOR OUR AREA... ATTM...THE LONGER RANGE MODEL GUIDANCE PLACES A SLOW MOVG FRONTAL SYSTEM ACROSS WRN NEW ENGLAND BY ERLY SAT AM W/ PRECIP BEGINNING TO OVERSPREAD OUR WRN AREAS. THIS FRONTAL BNDRY CONTS TO SLOWLY PUSH EWRD THEN STALL OVR THE AREA AS THE UPPER SUPPORTING TROF IS FCST TO CUTOFF WELL S OF THE AREA W/ A RATHER MOIST AND UNSETTLED ENERLY FLOW TO DVLP ACROSS OUR AREA AND PERSIST THRU THE REMAINDER OF LONG TERM PD. MAIN UNCERTAINTY DURING THIS PD WILL BE THE EXTEND THAT THE CUTOFF TO OUR S WILL BE ABLE TO KEEP DEEPER MOISTURE ACROSS OUR AREA. PLACEMENT MAY BE FAR ENUF S THAT ONLY OCNL SHOWERS DOMINATE THE WX PTRN AND ANY FURTHER SRN SHIFT COULD RENDER SPCLY NRN AREAS MAINLY DRY. GIVEN THESE UNCERTAINTIES...WILL CARRY MOSTLY JUST CHC POPS THRU THE PD. TEMPS WILL START A LITTLE ABV SEASONAL NORMS AND THEN COOL TO NR OR JUST SLIGHTLY BLO SEASONAL NORMS DEPENDING ON CLD CVR AND PRECIP. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... NEAR TERM: VFR CONDITIONS EARLY THIS MORNING WILL GIVE WAY TO SOME MVFR CONDITIONS IN SHOWERS ACROSS NORTHERN AREAS THIS MORNING. VFR/MVFR BKN-OVC CIGS ARE POSSIBLE THIS AFTERNOON. MVFR/IFR IS EXPECTED TO DEVELOP LATE TONIGHT DEVELOPING LOW CLOUDS AND PATCHY FOG ESPECIALLY KBGR/KBHB WHERE LIFR CONDITIONS ARE POSSIBLE AFTER 06Z. SHORT TERM: A WARM AND INCREASINGLY HUMID SRLY FLOW WILL LEAD TO INCREASING CHCS FOR FOG SPCLY SRN AREAS DURING THE OVRNGT/ERLY AM HRS W/ THESE CONDS LIKELY INTO SUN. OTHERWISE VFR CONDS ARE ANTICIPATED. && .MARINE... NEAR TERM: WIND/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH TONIGHT. VISIBILITY WILL BE REDUCED TO 1 TO 3 NM IN AREAS OF FOG LATE TONIGHT. SHORT TERM: WNDS/SEAS EXPECTED TO REMAIN BLO SCA LEVELS THRU THE PD THO SEAS MAY APPROACH 5 FT LATE IN THE PD IN PERSISTENT SRLY FLOW. ALSO EXPECT FOG TO BECOME RATHER PREVALENT W/ THE WARM AND HUMID SRLY FLOW OVR THE COLD ATLC WATERS... && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...DUDA/MCW SHORT TERM...KHW LONG TERM...KHW AVIATION...DUDA/MCW/KHW MARINE...DUDA/MCW/KHW
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1214 PM EDT WED MAY 14 2014 .SYNOPSIS... HIGH PRESSURE WILL SLIDE EAST TODAY AND RETURN FLOW SETS UP OVER THE AREA. AN UNSETTLED WEATHER PATTERN WILL BE IN PLACE THURSDAY THROUGH EARLY NEXT WEEK AS A SLOW-MOVING COLD FRONT APPROACHES OVER THE WEEKEND...THEN LOW PRESSURE DEVELOPS ALONG IT NEARBY AND LINGERS INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 1215 PM UPDATE...UPDATED THE FORECAST TO ACCOUNT FOR SUNNIER CONDITIONS FOR THE AFTERNOON...MAINLY ACROSS NEW HAMPSHIRE. OTHERWISE...FORECAST REMAINS LARGELY UNCHANGED. 1030 AM UPDATE...A FEW MINOR ADJUSTMENTS TO THE FORECAST BASED ON LATEST TRENDS IN OBSERVATIONAL DATA. MOST OF THE AREA WILL REMAIN DRY TODAY EXCEPT FOR A FEW SHOWERS IN THE NORTH AND EASTERN ZONES. OTHERWISE...CLOUDS WILL PREVAIL WITH BREAKS OF SUN AT TIMES. HIGHS SHOULD GET INTO THE 70S WELL INLAND...WITH 50S ALONG THE COAST. PREVIOUSLY... UPDATE...A FEW MINOR ADJUSTMENTS TO POP BASED ON LATEST RADAR TRENDS. WAA SHRA ARE SLIDING EWD TOWARDS CENTRAL ME. REMNANTS OF NY STATE CONVECTION ARE ALSO DISSIPATING ACROSS WRN NH. GRADUALLY WE SHOULD WORK TOWARDS DRY WX FOR MOST OF THE AREA THIS AFTERNOON. PREVIOUS DISCUSSION...CONVECTIVE COMPLEX OVER NY STATE IS SLOWLY SAGGING S AND DRYING UP AS IT MOVES EWD. THIS TREND SUPPORTS HI- RES MODEL SOLUTIONS LIKE THE HRRR/RAP. HOWEVER A WING OF WAA WILL BRUSH THE CWFA THIS MORNING...AS UPPER RIDGE AXIS SLIDES EWD. THESE SHRA ARE ELEVATED IN NATURE AND THERE REMAINS SOME LINGERING DRY AIR AT THE SFC ESPECIALLY ACROSS WRN ME. WILL LEAVE ANY MENTION OF PCPN AT SCT OR ISOLD ATTM. AS RETURN FLOW SETS UP TODAY BROAD WAA WILL SUPPORT A MIX OF SUN AND CLOUDS. TEMPS WILL MODERATE SOME THOUGH...ESPECIALLY ACROSS NH. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... FOCUS TONIGHT WILL BE ON DEVELOPING MARINE FOG/STRATUS. MESOSCALE MODELS AND MOS GUIDANCE BOTH SUGGEST IT WILL OCCUR. ATTM IR SATELLITE SHOWS A LARGE AREA OF STRATUS OVER THE MID ATLANTIC...SLOWLY EXPANDING NWD. LATEST HRRR HAS A VERY GOOD HANDLE ON THIS AREA AND CLOUD HEIGHTS WITHIN IT. IN THE NEXT SEVERAL HOURS IT DEVELOPS STRATUS IN THE GULF OF ME. ATTM STRATUS IS ABSENT HERE ON SATELLITE IMAGERY. FEEL THAT IT MAY BE SLIGHTLY OVERAGGRESSIVE DUE TO THE COLD WATER TEMPS IN THE GULF. HOWEVER DURING THE DAY AS WINDS TURN MUCH MORE SLY OVER A LONGER FETCH TO OUR S THIS AREA OF FOG/STRATUS SHOULD DEVELOP QUICKLY. CURRENT FORECAST IS FOR THIS AREA TO MOVE ONSHORE BY OR SHORTLY AFTER 00Z. SOME SHALLOW LIFT COUPLED WITH DRY AIR ALOFT WILL LIKELY LEAD TO SOME DZ THROUGHOUT THE NIGHT AS WELL. DIURNAL HEATING AND INCREASING SLY WINDS SHOULD HELP TO PARTIALLY MIX OUT THE STRATUS DURING THE DAY THU. THIS HEATING COULD ALSO LEAD TO SCT AFTERNOON SHRA. ON THE NRN AND WRN FRINGES OF THE MARINE LAYER MARGINAL LAPSE RATES WILL BE PRESENT ALOFT. NAM BUFKIT SOUNDINGS YIELD CAPE AOA 500 J/KG FOR THESE AREAS...SO WILL MAINTAIN SOME MENTION OF THUNDER DURING THE DAY THU. && .LONG TERM /FRIDAY THROUGH TUESDAY/... A SLOW MOVING FRONTAL BOUNDARY WILL APPROACH NEW ENGLAND THURSDAY NIGHT FROM THE WEST. WAVES OF LOW PRESSURE ALONG THIS FRONT WILL SLOW THE PROGRESS OF THIS SYSTEM AS IT BUMPS INTO THE UPPER LEVEL RIDGE WITH TIME. AHEAD OF THE PRECIPITATION...EXPECT WARM AND MUGGY CONDITIONS ON FRIDAY AWAY FROM THE COAST. ALONG THE SHORELINE...IT WILL BE A COOLER DUE TO AN ONSHORE FLOW. PATCHY DRIZZLE AND FOG IS LIKELY AS WELL...MAINLY DURING THE MORNING AND EVENING HOURS. 00Z MODEL SUITE HAS SOME DISAGREEMENT ON THE TIMING OF THE BAND OF PRECIPITATION ASSOCIATED WITH THE SLOW MOVING COLD FRONT. THE EURO IS THE FASTEST WITH THIS PRECIPITATION...WHILE THE GFS HOLDS MOISTURE TO THE WEST...KEEPING MUCH OF OUR FORECAST AREA DRY FRIDAY NIGHT...WITH THE EXCEPTION OF SOUTHWEST NEW HAMPSHIRE. WILL ALLOW FOR A COMPROMISE IN TERMS OF THE TIMING OF THE PRECIP. SHOWERS MAY BE LOCALLY HEAVY SATURDAY MORNING...MAINLY OVER NEW HAMPSHIRE AS DEEP LAYERED MOISTURE ENTERS THE REGION FROM WELL OFF THE EASTERN SEABOARD. A WEAK AREA OF LOW PRESSURE SLOWLY DEVELOPS ALONG THIS FRONT OFF THE NEW ENGLAND COASTLINE LATE IN THE WEEKEND AND EARLY NEXT WEEK. THIS WILL ALLOW A PERSISTENT COOL AND MOIST MARITIME FLOW OVER THE REGION WITH AT LEAST SCATTERED SHOWERS ON A DAILY BASIS. PREFER THE GFS SOLUTION WITH QPF THROUGH THIS EXTENDED TIME RANGE...BRINGING UP TO THREE INCHES OF RAIN FOR THE FOOTHILLS OF MAINE AND THE HIGHER TERRAIN OVER CENTRAL/NORTHERN NEW HAMPSHIRE. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM...VFR CONDITIONS GENERALLY EXPECTED TODAY. WILL HAVE TO WATCH FOR BKN MVFR DECK OF CLOUDS TO DEVELOP WITH DIURNAL HEATING...AS SUGGESTED BY SOME SHORT TERM GUIDANCE. THEN FOCUS TURNS TO MARINE FOG/STRATUS AS WARM...MOIST AIR RETURNS NWD. MESOSCALE MODELS ARE IN AGREEMENT THAT IT WILL FORM AROUND OR SHORTLY AFTER 00Z THIS EVENING. EXPECTED WIDESPREAD IFR OR LOWER FOR COASTAL TERMINALS. LONG TERM...IFR OR LOWER CONDITIONS EXPECTED AGAIN THU NIGHT IN MARINE FOG/STRATUS. SOME IMPROVEMENT DURING THE DAY FRI BEFORE COLD FNT APPROACHES WILL DETERIORATING CIGS/VSBYS AND POSSIBLE HEAVY RNFL INTO SAT. && .MARINE... SHORT TERM...DEEP SLY FLOW EXPECTED TO DEVELOP TODAY AS HIGH PRES SHIFTS E OF THE WATERS. LATE THU SEAS ON THE OUTER WATERS WILL BEGIN TO BUILD TOWARDS 5 FT. EXPECT VSBY RESTRICTIONS IN FOG BEGINNING TONIGHT. LONG TERM...WINDS GENERALLY EXPECTED TO REMAIN BELOW SCA THRESHOLDS...THOUGH SUSTAINED SLY FLOW WILL BRING SEAS ABOVE 5 FT FOR AN EXTENDED PERIOD THROUGH THE WEEKEND. && .FIRE WEATHER... DEEP SOUTHERLY FLOW DEVELOPING TODAY WILL KEEP MOISTURE ON THE RISE THROUGH THE WEEKEND. DESPITE WARMING TEMPERATURES...RISING MOISTURE WILL ALSO KEEP RELATIVE HUMIDITY VALUES IN THE MODERATE RANGE DURING THE DAY AND HIGH AT NIGHT. THE BEST CHANCE FOR WETTING RAINS WILL BE LATE FRIDAY INTO SATURDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
244 PM EDT WED MAY 14 2014 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OFFSHORE THROUGH THE REST OF THE WEEK. A COLD FRONT EXTENDING FROM THE GREAT LAKES TO THE GULF COAST STATES WILL TRACK SLOWLY EAST...MOVING INTO THE MID ATLANTIC STATES THURSDAY AND FRIDAY. HIGH PRESSURE IS EXPECTED TO RETURN TO THE MID ATLANTIC THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... EASTERLY FLOW HAS MOVED INTO THE MID ATLANTIC RESULTING IN A 2.5K FT STRATUS DECK ON THE COLD SIDE OF A BACK DOOR COLD FRONT THIS MORNING. A BINARY RESULT OF SKY COVER HAS OCCURRED ACROSS THE REGION DUE TO THE MARINE LAYER. LOCATIONS IN THE CENTRAL FOOTHILLS...ALONG RIDGE LINES AND PARTS OF THE POTOMAC HIGHLANDS ARE GETTING FULL SUN THIS MORNING. WEAK FLOW WITHIN THE MARINE LAYER AS WELL AS ON TOP OF THE MARINE LAYER WILL LEAD TO A SLOW DISSIPATION FROM WEST TO EAST OF STRATUS TODAY. THIS WILL LEAD TO TEMPS REACHING THE LOW 70S IN NE MD TO THE UPPER 70S IN NOVA AND THE PANHANDLE OF WV. FCST SOUNDINGS THAT HAD A HANDLE ON THE MARINE LAYER FROM THE 12Z IAD RAOB SHOWS THE POTENTIAL FOR BREAKS IN THE CLOUDS THIS AFTERNOON WITH NE MD INCLUDING BALTIMORE METRO BEING THE LAST TO BREAK BY LATE AFTERNOON. OVERALL...NOT EXPECTING STRATUS DECK TO ERODE DURING THE DAY FOR AREAS EAST OF THE BLUE RIDGE INCLUDING THE I-95 CORRIDOR AND PIEDMONT. ELSEWHERE...FULL SUN WILL LEAD TO TEMPS REACHING THE 80S TODAY AND PER THE 12Z RNK RAOB WHICH IS UPSTREAM... INSTABILITY OF UP TO 2000 J/KG IS POSSIBLE. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO FORM DUE TO TERRAIN CIRCULATIONS AS WELL AS ON THE DIFFERENTIAL HEATING BOUNDARY OF THE MARINE LAYER. SOME STORMS WILL BE CAPABLE OF STRONG UPDRAFTS AND THEREFORE DMG WINDS AND LARGE HAIL ARE POSSIBLE. SHEAR PROFILES INCREASE IN MAGNITUDE FROM THE CENTRAL FOOTHILLS TO THE POTOMAC HIGHLANDS AND THEREFORE A HIGHER CHANCE FOR SEVERE THUNDERSTORMS ACROSS THE POTOMAC HIGHLANDS. 11Z HRRR SHOWS CONVECTION STARTING AFTER 16Z TODAY. THE STORM MOTION WILL BRING SHOWERS AND THUNDERSTORMS NORTH AND EAST BUT THE STABLE AIRMASS WILL LIKELY CAUSE THUNDERSTORMS TO DISSAPTE. PREVIOUS DISCUSSION... ANY LEFTOVER CONVECTION THIS EVENING WILL DISSIPATE OVERNIGHT AND A SOUTHEAST FLOW IS EXPECTED AHEAD OF AN APPROACHING COLD FRONT AND BEHIND DEPARTING HIGH PRESSURE OFF THE NEW ENGLAND COAST. LOW CLOUDS ALONG WITH AREAS OF FOG AND DRIZZLE ARE EXPECTED OVERNIGHT. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/... ...UPDATE...A FLASH FLOOD WATCH IS IN EFFECT FOR MOST COUNTIES IN THE FORECAST AREA THURSDAY THROUGH FRIDAY... PREVIOUS DISCUSSION... A STRONG UPPER-LEVEL TROUGH WILL DIG OVER THE MIDWEST AND GULF COAST STATES THURSDAY WHILE THE COLD FRONT ASSOCIATED WITH THIS TROUGH SLOWLY TRACKS EAST TOWARD OUR AREA BY LATE IN THE DAY. THE TROUGH AXIS WILL SWING TOWARD BEING NEGATIVELY TILTED...ALLOWING FOR MORE HEIGHT FALLS WITHIN THE WARM SECTOR. THE FORCING ALONG THE FRONT WILL BE QUITE STRONG DUE TO A STRONG PRESSURE GRADIENT BETWEEN THE FRONT AND HIGH PRESSURE OVER THE ATLANTIC OCEAN. THE STRONG FORCING WILL COMBINE WITH DEEP TROPICAL MOISTURE BEING ADVECTED INTO THE AREA AHEAD OF THE BOUNDARY...TO CAUSE WIDESPREAD SHOWERS WITH LOCALLY HEAVY RAINFALL AHEAD OF THE COLD FRONT. THIS ACTIVITY IS EXPECTED TO OVERSPREAD THE POTOMAC HIGHLANDS THURSDAY AFTERNOON. FURTHER EAST ACROSS THE WASHINGTON AND BALTIMORE METROPOLITAN AREAS...A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON BUT THE WIDESPREAD PRECIPITATION MAY REMAIN TO THE WEST DUE TO THE SLOW MOVEMENT OF THE COLD FRONT. DESPITE PLENTY OF CLOUD COVER...FAVORABLE SHEAR PROFILES AND HIGH DEWPOINTS SUGGEST THAT THERE IS A THREAT FOR SEVERE THUNDERSTORMS THURSDAY AFTERNOON. A SLOW BUT STEADY ARRIVAL OF THE MOISTURE PLUME EXPECTED LATE THU EVE. EARLIER IN THE DAY...THE PARENT UPPER TROUGH WILL HAVE DIVED DOWN WELL INTO THE LOWER MS VLY. THE HIGHLY AMPLIFIED TROUGH AXIS WILL ESSENTIALLY SCOOP A DENSE SECTOR OF GULF MOISTURE OVER A RELATIVELY THIN AXIS. THIS MOISTURE AXIS WILL BE JUST ON THE LEE SIDE OF THE UPPER TROUGH...BUILDING AND DRIFTING NNE ACROSS THE SRN APLCNS THU MRNG/AFTN. HEADING INTO THE LATE EVE/NIGHTTIME HRS...THE UPPER VORT POWERING THE TROUGH WILL BEGIN TO TILT NEGATIVELY WHICH IS AN INTENSIFICATION PHASE FOR THE SYSTEM - MAXIMIZING THE AMOUNT OF QPF POSSIBLE W/ THE SYSTEM. MOST MED RANGE MEMBERS GIVING THE WRN HALF OF OUR CWA A PORTION OF THE BULLSEYE FOR POTENTIAL QPF - MAINLY DURING THE THU LATE NIGHT AND EARLY MRNG HRS FRI. A FLASH FLOOD WATCH WILL LIKELY BE NEEDED WITHIN THE NEXT FORECAST PERIOD OR SO...WHICH THE SOLID CONSENSUS OF QPF DEPICTIONS. LOCALLY INTENSE RAINFALL AND EMBEDDED CONVECTIVE ELEMENTS WILL CREATE THE POTENTIAL FOR AT LEAST A COUPLE OF INCHES OF RAIN OVER THE SHEN VLY/APLCNS. A SFC LOW PRES SYSTEM WILL DEVELOP OFF THE LEE SIDE OF THE HIGHER TERRAIN AND STRENGTHEN AS IT EFFECTIVELY TRACKS RIGHT ACROSS OUR CWA. THE TRACK WILL DETERMINE THE CONVECTIVE POTENTIAL FOR THE AREA...THOUGH EMBEDDED ELEVATED CONVECTION AT VERY LEAST WILL BE POSSIBLE ACROSS THE REGION. THE MODERATE TO HEAVY RAIN BATCHES WILL CONTINUE TO MOVE EWD DURING THE PREDAWN HRS FRI OVER THE BLUE RIDGE AND EAST. THE I-95 CORRIDOR WILL BE HIGHLIGHTED DURING THE FIRST-HALF OF THE DAY FRI...W/ EMBEDDED AREAS OF HEAVY RAIN SPREADING ACROSS THE AREA AND A STILL INTENSE LOW LEVEL JET HELPING TO KEEP THE INTENSITY OF THE SYSTEM INTACT. A QUICK END TO THE PRECIP LINE WILL ARRIVE TOWARD THE MID-LATE AFTN W/ ONLY A FEW RESIDUAL SHOWERS OCCURRING IN THE BACK EDGE SUBSIDENCE REGION. THE MOISTURE AXIS WILL DISSIPATE AS IT ARRIVES OVER DELMARVA AND MOVES OFF THE COAST LATE FRI EVE. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AN UPPER LOW DRIFTING DOWN FROM SOUTH OF THE HUDSON BAY AROUND WILL ROTATE AROUND THE GREAT LAKES INTO THE COMING WEEKEND...KEEPING OUR AREA QUITE COOL AND RELATIVELY DRY. THE "WEATHER" FROM THIS FEATURE WILL MAKE IT FEEL MORE LIKE MARCH THAN MAY...EVEN THOUGH AVG TEMPS FOR MID-MAY ARE IN THE M70S. A SLOW MOVING AND COLD UPPER LOW TAKING A FEW DAYS TO EXIT THE NORTHEAST WILL KEEP US IN THIS PATTERN WELL INTO NEXT WEEK. IT MAY BE SEVERAL MORE DAYS BEFORE WE GET ANYWHERE CLOSE TO 80 DEG OR MORE...BASED ON THE PATTERN SETTING UP FOR NEXT WEEK. THE HUDSON BAY LOW WILL SLOWLY DRIFT OFF THE NEW ENGLAND COAST AS AN UPPER RIDGE BUILDS TO THE WEST. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... IFR CONDITIONS ARE EXPECTED THROUGH MID-MORNING DUE TO LOW CLOUDS ALONG WITH AREAS OF FOG AND DRIZZLE. CIGS SHOULD IMPROVE TO MVFR LEVELS LATE THIS MORNING AND AFTERNOON...BUT MORE IFR/SUBIFR CONDITIONS ARE EXPECTED LATE TONIGHT INTO EARLY THURSDAY. CIGS/VSBYS SHOULD IMPROVE THURSDAY AFTERNOON. A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING MAINLY FOR CHO AND MRB...AND AGAIN THURSDAY AFTERNOON FOR ALL TERMINALS. A COLD FRONT WILL CAUSE WIDESPREAD SHOWERS WITH LOCALLY HEAVY RAINFALL AND A FEW THUNDERSTORMS THURSDAY NIGHT INTO FRIDAY. CONDITIONS WILL IMPROVE LATER FRIDAY. HIGH PRESSURE WILL BUILD OVERHEAD DURING THE WEEKEND. A STRONG LOW PRESSURE SYSTEM WILL MOVE ACROSS THE REGION FROM LATE THU INTO FRI. MAINLY PERIODS OF HEAVY RAIN WOULD BE THE CONCERN...W/ BREEZY SFC WINDS BUT EVEN STRONGER LOW LEVEL FLOW - A GOOD 30-50KT IN THE BOUNDARY LAYER OUT AHEAD OF THE SFC LOW LATE THU INTO EARLY FRI. A COLD FRONT WILL PUSH THE PRECIP AND ANY EMBEDDED TSTMS OFF THE COAST BY LATE FRI...W/ COOLER AND DRIER AIR BEING USHERED IN FOR THE COMING WEEKEND. && .MARINE... AN EASTERLY FLOW THIS MORNING WILL TURN TO THE SOUTHEAST THIS AFTERNOON AS HIGH PRESSURE MOVES OFF THE NEW ENGLAND COAST. THE SOUTHEAST FLOW WILL CONTINUE THROUGH THURSDAY. THE PRESSURE GRADIENT WILL INCREASE DURING THIS TIME AND A SMALL CRAFT ADVISORY IS IN EFFECT FOR THURSDAY AFTERNOON. HOWEVER...WIND GUSTS MAY APPROACH SCA CRITERIA TONIGHT THROUGH THURSDAY MORNING...BUT GUSTS HAVE BEEN CAPPED AROUND 15 KNOTS FOR NOW DUE TO THE RELATIVELY COOLER WATERS AND WEAKER PRESSURE GRADIENT. SFC WINDS WILL INCREASE OUT OF THE S-SE THU AFTN/EVE AHEAD OF A SFC LOW PRES SYSTEM. WIDESPREAD RAIN AND ISOLATED TSTMS WILL ARRIVE INTO THE EARLY MRNG HRS FRI. WINDS WILL MAX-OUT IN THE UPPER SCA/LOW-END GALE RANGES AS THE LOW PUSHES EAST AND MOVES OVER THE WATERS. WINDS BEHIND THE SYSTEM WILL SUBSIDE WELL BELOW SCA CRIT HEADING INTO THE WEEKEND...W/ ONLY A LIGHT W/NW BREEZE EXPECTED. THIS WILL ALSO LAST INTO EARLY NEXT WEEK. && .TIDES/COASTAL FLOODING... TIDAL ANOMALIES HAVE INCREASED UP TO AROUND ONE-HALF FOOT ABOVE NORMAL THIS MORNING DUE TO AN ONSHORE FLOW. THE ONSHORE FLOW SHOULD REMAIN WEAK ENOUGH TO KEEP WATER LEVELS BELOW MINOR COASTAL FLOODING THRESHOLDS. THE HIGH TIDE THIS AFTERNOON INTO THIS EVENING WILL BE THE LOWER OF THE TWO...SO WATER LEVELS SHOULD REMAIN BELOW MINOR FLOODING THRESHOLDS...DESPITE AN INCREASE IN TIDAL ANOMALIES. THE ONSHORE FLOW WILL CONTINUE TONIGHT THROUGH THURSDAY NIGHT AND POSSIBLY INTO FRIDAY BEFORE TURNING OFFSHORE BEHIND A COLD FRONT LATER FRIDAY. DESPITE THE ONSHORE FLOW REMAINING WEAK TONIGHT...MINOR COASTAL FLOODING IS POSSIBLE WITH THE HIGH TIDE CYCLE LATE TONIGHT INTO THURSDAY MORNING SINCE IT WILL BE THE HIGHER OF THE TWO. THE ONSHORE FLOW WILL STRENGTHEN LATER THURSDAY THROUGH THURSDAY NIGHT. MINOR FLOODING IS LIKELY NEAR HIGH TIDES DURING THIS TIME. TIDAL ANOMALIES WILL GRADUALLY DECREASE FRIDAY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...FLASH FLOOD WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY AFTERNOON FOR DCZ001. MD...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY AFTERNOON FOR MDZ003-501-502. FLASH FLOOD WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY AFTERNOON FOR MDZ004>007-009>011-013-014-016. VA...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY AFTERNOON FOR VAZ025>031-503-504. FLASH FLOOD WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY AFTERNOON FOR VAZ036>040-042-050>056-501-502. WV...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY AFTERNOON FOR WVZ050>053-055-501>506. MARINE...SMALL CRAFT ADVISORY FROM NOON TO 6 PM EDT THURSDAY FOR ANZ530>543. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
302 PM EDT WED MAY 14 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 527 AM EDT WED MAY 14 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A HIGH AMPLITUDE PATTERN OVER NAMERICA...CONSISTING OF A RIDGE ALONG THE W COAST AND A TROF EXTENDING FROM NRN CANADA TO TX. WITHIN THE TROF...THE NRN STREAM FEATURES A MIDLEVEL LOW OVER NRN ONTARIO TO THE SW OF HUDSON BAY... BUT NRN STREAM ENERGY IS DIVING S ALONG THE SASKATCHEWAN/MANITOBA BORDER REGION. IN THE SRN PART OF THE TROF...A SHORTWAVE IS OVER TX/OK. EXACTLY HOW THE AFOREMENTIONED SOUTHWARD DIVING NRN STREAM ENERGY INTERACTS WITH THE SRN PLAINS SHORTWAVE WILL BE KEY TO THE WEATHER IN THE NEXT COUPLE OF DAYS...INCLUDING THE POTENTIAL FOR VERY LATE SEASON ACCUMULATING SNOW WHICH IS LOOKING A BIT MORE LIKELY FOR SOME AREAS. DRIER AIR MASS HAS PUSHED INTO THE FCST AREA OVER THE LAST 12-18HRS. WHILE 00Z KGRB SOUNDING SHOWED DRY LOW TO MID LEVELS...UPSTREAM KINL SOUNDING SHOWED MOISTURE EXTENDING UP TO AROUND 700MB. SOME OF THIS MOISTURE WILL PROBABLY MANIFEST ITSELF AS HIGHER BASED SCT-BKN CU/STRATOCU THIS AFTN...ESPECIALLY INLAND FROM LAKE SUPERIOR. ISOLD/SCT -SHRA WERE COMMON UPSTREAM YESTERDAY...BUT WITH DRY BOUNDARY LAYER AND LOW-LEVEL FLOW HERE TRENDING ANTICYCLONIC RATHER THAN CYCLONIC AS IT WAS YESTERDAY WHERE THE SHRA WERE OCCURRING... DON`T EXPECT ANY -SHRA/SPRINKLES IN THE FCST AREA TODAY. LAKE BREEZES WILL DEVELOP OFF LAKE SUPERIOR AND LAKE MICHIGAN TODAY... KEEPING LAKESIDE LOCATIONS CHILLY THIS AFTN. INLAND...DEEP MIXING TO TOWARD 750MB ON FCST SOUNDINGS YIELDS MAX TEMPS IN THE MID TO UPPER 50S. MAY SEE A FEW READINGS AROUND 60F OVER THE SCNTRL. DWPTS WILL MIX OUT INTO THE MID 20S THIS AFTN...RESULTING IN MIN RH DOWN AROUND 30PCT IN THE INTERIOR W HALF THIS AFTN. FAIRLY LIGHT WINDS/MOIST GROUND WILL LIMIT FIRE WX CONCERNS. NRN STREAM ENERGY DIVING S INTO THE NRN PLAINS TODAY WILL CONTINUE S INTO IA TONIGHT. THIS WILL HELP PULL SRN PLAINS SHORTWAVE N INTO IL BY SUNRISE WED WITH ORGANIZING SFC LOW LIFTING INTO ERN IN. PUSH OF WAA/ISENTROPIC ASCENT AND DEEP LAYER FORCING AHEAD OF WAVE ALONG WITH STRONG MOISTURE TRANSPORT WILL LEAD TO EXPANDING PCPN SHIELD LIFTING N INTO THE GREAT LAKES TONIGHT. NRN FRINGE OF PCPN MAY REACH THE FAR E AND SE FCST AREA AROUND SUNRISE THU. INCLUDED SCHC POPS IN THAT AREA. WETBULB ZERO HEIGHTS/1000-850MB THICKNESS SUGGEST THERE COULD BE SOME SNOWFLAKES MIXED IN WITH THE RAIN IF PCPN DOES IN FACT ARRIVE LATE TONIGHT. OTHERWISE...EXPECT INCREASING CLOUDS TONIGHT WITH LOW TEMPS IN THE 30S. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 447 AM EDT WED MAY 14 2014 ...MODELS TRENDING BACK TO STRONGER SYSTEM/ACCUMULATING SNOW TO END THE WEEK... HIGHLY AMPLIFIED UPPER LEVEL PATTERN IN PLACE LATE THIS WEEK AS UPPER TROUGH WITH H5 HEIGHTS OF 2-3 STANDARD DEVIATIONS BLO CLIMO CENTERED OVER THE MIDDLE MISSISSIPPI RIVER VALLEY. STILL HINTS THAT THIS UPPER TROUGH BECOMES CLOSED OFF BY FRIDAY AS IT CROSSES THE WESTERN GREAT LAKES. COUPLE OF SHORTWAVES LIFTING NEARLY DUE NORTH ON LEAD FLANK OF THE UPPER LOW MAY LOOKS TO BRING AT LEAST A BRIEF SHOT OF WINTRY PRECIP TO UPPER LAKES LATER THURSDAY INTO FRIDAY. PORTION OF TROUGH MOVES TOWARD MID ATLANTIC THIS WEEKEND WHILE HEIGHTS SLOWLY BEGIN TO REBOUND OVER THE GREAT LAKES. RIDGING ALOFT MAKES RETURN TO UPPER LAKES REGION EARLY NEXT WEEK BUT SINCE THE LOW-LEVELS REMAIN UNDER FIRM INFLUENCE OF SFC HIGH AND WORKED OVER CP AIRMASS...ONLY MODERATE WARMING WILL OCCUR BY NEXT WEEK WITH TEMPS LIKELY REMAINING AT OR BLO NORMAL. PRIMARY FOCUS IN THE LONG TERM IS ON THE SYSTEM AND POSSIBLE WINTRY PRECIPITATION THURSDAY INTO FRIDAY. APPEARS THAT THE 00Z ECMWF RUN FROM TUE 5/13 WAS AN ABERATION...AS WITH THE 12Z RUN ON TUE 5/13 THE UPPER LOW IS CLOSED OFF AGAIN...DRAWING THE PRIMARY SHORTWAVE AND SFC WAVE BACK WEST AGAIN SPREADING QPF OVER MAINLY EAST THIRD OF CWA THROUGH 00Z FRIDAY. LATEST SET OF MODEL RUNS NOT SET ON ANY ONE IDEA THOUGH AS ESSENTIALLY WE CONTINUE TO SEE ALL THE DIFFERENT ENSEMBLE MEMBERS WITH THIS SYSTEM. EVEN WITH THAT UNCERTAINTY THOUGH...ENOUGH OF TREND EMERGING TO INCREASE POPS SIGNIFICANTLY THURSDAY/THURSDAY NIGHT/FRIDAY. NAM FARTHEST WEST WITH THE INITIAL SHORTWAVE AND PV ANAMOLY AND ASSOCIATED QPF ON THURSDAY. FARTHEST EAST IDEA IS UKMET WHICH FOCUSES MOST OF ITS FORCING/MOISTURE WITH THE SHORTWAVE OVER FAR EASTERN UPR MICHIGAN AND TO THE EAST. LATEST GFS AND GEM ALONG WITH 12Z ECMWF ARE IN BETWEEN THESE TWO EXTREMES AND FOCUS WHAT LOOKS LIKE AREA OF TROWAL/DEFORMATION PRECIP OVER THE EAST HALF OF CWA THROUGH 00Z FRIDAY. PTYPE FOR THIS INITIAL WAVE OF PRECIP LIKELY WOULD BE MOSTLY A MIX OF RAIN/SNOW...THOUGH HIGHER TERRAIN AREAS OF NCNTRL UPR MICHIGAN COULD SEE JUST SNOW BY LATER AFTN. LATER THURSDAY NIGHT INTO FRIDAY THERE ARE HINTS FROM THE ECMWF AND ESPECIALLY THE GFS/NAM THAT MID-LEVEL FRONTOGENESIS H7-H6 IMPACTS LK SUPERIOR AND NORTH CENTRAL AND PERHAPS NORTHWEST CWA AT LEAST FRIDAY MORNING AS TEMP GRADIENT STRENGTHENS AT H7 DUE TO PERSISTENT COLD/WARM ADVECTION ALONG AXIS OVER CNTRL LK SUPERIOR. MAY BE GETTING LOST IN THE DETAILS HERE...BUT FN CONVERGENCE IS DECENT AND THERE IS ALSO FS VECTOR CONVERGENCE THAT SUGGESTS AN AREA OF WIDESPREAD PRECIPITATION WOULD PIVOT ACROSS THOSE PORTIONS OF THE CWA. ADDED LIFT WILL BE PROVIDED BY NNW WINDS UPSLOPING OVER HIGHER TERRAIN OF NW AND NCNTRL CWA. AGAIN...THIS IS ONE MODEL RUN OF MANY DIFFERENT TAKES ON THIS SYSTEM...BUT GIVEN UPPER LOW DEEPENING AND SHORTWAVES WRAPPING INTO THE BACK SIDE OF THE UPPER LOW...THE GENERAL IDEA OF ENHANCED FRONTOGENESIS OCCURRING HAS SOME MERIT. UNCERTAINTY OF THAT FEATURES PLACEMENT IS MAIN ISSUE FROM INTRODUCING THAT KIND OF DETAIL TO FORECAST ATTM. TEMP GRADIENT ALOFT WEAKENS IN THE AFTN...SO INTENSITY OF MID-LEVEL LIFT/FGEN SHOULD DO LIKEWISE. LINGERING LOW-LEVEL MOISTURE AND UPSLOPE LIFTING SHOULD KEEP LIGHT PRECIP GOING INTO THE AFTN THOUGH. BASED ON LIFT OVER THE AREA WITH H85 TEMPS WELL BLO ZERO AND 1000-850MB THICKNESSES BLO 1300M...AND NOT MUCH OF ABOVE FREEZING NEAR SFC LAYER SHOWING UP IN THE SOUNDINGS...PTYPE THURSDAY NIGHT INTO FRIDAY MORNING FOR THE MOST PART WILL BE SNOW ACROSS MUCH OF CWA. BY FRIDAY AFTN...BLYR WARMING WILL ALLOW FOR MIX OF RAIN/SNOW SHOWERS OVER LOWER ELEVATIONS OF CWA...ESPECIALLY EASTERN HALF. NOW THE MAIN QUESTION TURNS TO SNOW AMOUNTS. AS WITH ANY SNOW THIS LATE IN THE SEASON THE MAIN HURDLES OF WARM GROUND TEMPS...SNOW INTENSITY...TIME OF DAY...ALL HAVE TO BE CONSIDERED. BUT...AT LEAST IN THESE LATITUDES IT IS NOT UNHEARD OF AT ALL TO SEE SIGNIFICANT LATE SEASON SNOWS. LOCAL RECORDS/OTHER ACCOUNTS INCLUDE A SEVERAL INCH SNOWSTORM THAT OCCURED OVER HIGHER TERRAIN OF NORTH CENTRAL UPR MICHIGAN EARLY IN JUNE OF 1945...AND THERE HAVE BEEN OTHERS THAN HAVE OCCURRED IN LATE MAY EVEN AS FAR SOUTH AS WISCONSIN. THIS SYSTEM WILL HAVE TO BE WATCHED...AS IF THE REVERSAL OF TRACK MAJORITY OF MODELS ARE SHOWING COMES TO FRUITION...THERE IS A HIGHER POTENTIAL TO SEE SEVERAL INCHES OF WET SNOW OVER PARTS OF UPR MICHIGAN. LOOKING AT THE FACTORS MENTIONED ABOVE...GOOD PART OF SNOW OCCURS THURSDAY NIGHT INTO FRIDAY MORNING...SO THE INSOLATION WILL BE MINIMAL FACTOR IN CUTTING DOWN ON AMOUNTS...AND SNOW MAY FALL AT GOOD CLIP LATER THURSDAY NIGHT INTO FRIDAY...ESPECIALLY IF THE FGEN AND DEFORMATION AREA INCREASES AS SOME MODELS INDICATE. BEST GUESS TO START IS PROBABILITIES ARE PRETTY HIGH THAT AT LEAST A FEW INCHES OF WET SNOW WILL OCCUR OVER THE HIGHER TERRAIN OF THE KEWEENAW PENINSULA...PERHAPS AS FAR WEST AS THE PORCUPINE MOUNTAINS...AND ALSO OVER THE HIGHER TERRAIN OF BARAGA AND MARQUETTE COUNTIES. THESE AREAS WILL ALSO HAVE THE ADDED BENEFIT OF NW WINDS PROVIDING UPSLOPE LIFT. NOTEABLE IS THAT SOME OF THE ENSEMBLE OUTPUT FROM THE 03Z SREF MEMBERS TRENDED HIGHER THAN PREVIOUS RUNS...INDICATING MUCH MORE SNOW...WITH A FEW MEMBERS EVEN PRINTING OUT AMOUNTS OVER 6 INCHES...WITH ISOLATED MEMBERS OVER 10 INCHES. HOWEVER...SREF OUTPUT IS SEEMING TO KEY ON LARGER SCALE FORCING IMPACTING MOST OF UPR MICHIGAN AS IT SHOWS SEVERAL INCHES OF SNOW AS FAR SOUTH AS KIMT AND EAST AS KERY. SREF MEAN SHOWS 2-4 INCHES OVER THE HIGHER TERRAIN AREAS NEAR LK SUPERIOR AND PERHAPS AN INCH OR TWO IN THAT IMT TO ERY CORRIDOR. ENOUGH EVIDENCE TO PUT MENTION OF THIS SYSTEM INTO THE HAZARDOUS WEATHER OUTLOOK AND EHWO GRAPHICS. AND THEN WE WILL WAIT TO SEE WHAT THE LATER MODEL RUNS INDICATE. SYSTEM...HOWEVER STRONG IT ENDS UP BEING...WILL LEAVE A WELL ESTABLISHED CP AIRMASS OVER THE UPPER GREAT LAKES ON SATURDAY. HOWEVER...INLAND AREAS WILL MIX TO AROUND H85 SO TEMPS WILL PUSH INTO THE 50S DEGREES THERE. RIDGE AT THE SFC MOVING OVERHEAD WILL SUPPORT LAKE BREEZES WHICH WILL PACK A PUNCH NEAR LK SUPERIOR /KEEPING TEMPS IN THE LOWER 40S/ AS WATERS OFFSHORE ARE STILL VERY COLD OR EVEN ICE COVERED IN SOME AREAS. SFC RIDGE SLOWLY SLIDES ACROSS INTO MONDAY. TEMPS SUNDAY AND MONDAY WILL MODERATE INLAND WITH READINGS WELL INTO THE 60S BY MONDAY. ONSHORE WINDS WILL CONTINUE TO KEEP GREAT LAKES SHORES MUCH COOLER. THE COOL/DRY AIRMASS AND THE RIDGE WILL ALLOW NIGHTTIME LOWS TO DIP BELOW FREEZING FOR MANY SPOTS INLAND SATURDAY NIGHT THROUGH MONDAY NIGHT. NEAR THE SHORE...READINGS WILL LIKELY STAY JUST ABOVE FREEZING. NEXT CHANCE OF RAIN...YES JUST RAIN...ARRIVES LATER MONDAY AND MORE SO INTO TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1142 AM EDT WED MAY 14 2014 SCT-BKN LATE MORNING TO AFTERNOON CU HAVE DEVELOPED IN OUR OTHERWISE DRY LOW-LEVEL ENVIRONMENT. A FEW HIGH MVFR CEILINGS HAVE BEEN REPORTED UPSTREAM...BUT THEY ARE MORE TEMPORARY AND SHOULD COME IN HIGHER AS THEY MOVE CLOSER TO IWD AND CMX. AN AFTERNOON LAKE BREEZE SLIDING IN AT SAW WILL PUSH MOST OF THE CLOUDS S OF THE AIRPORT BY AROUND 20Z. ANY GUSTY WINDS /NEARING 25KTS AT CMX/ WILL QUICKLY DIMINISH LATE THIS AFTERNOON...WITH WINDS GENERALLY 5-10KTS OR LESS OVERNIGHT. WINDS WILL INCREASE AFTER 6-10Z THURSDAY /GUSTS NEARING 25KTS OUT OF THE N AT SAW BY LATE MORNING/ IN RESPONSE TO THE INCREASING PRESSURE GRADIENT BETWEEN THE STRONG HIGH PRESSURE SYSTEM SET UP ACROSS THE DAKOTAS/MN/ONTARIO...AND LOW SLIDING FROM INDIANA AT DAYBREAK TO E LOWER MI AND GREATER LAKE HURON BY 18Z THURSDAY. WITH THE ASSISTANCE OF UPSLOPE N WINDS...SAW COULD GET SOME RAIN BY 18Z THURSDAY. A FEW FLURRIES OR LIGHT SNOW MAY ALSO BE MIXED IN...PARTICULARLY BY THE EVENING HOURS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 301 PM EDT WED MAY 14 2014 A RIDGE OVER LAKE SUPERIOR WILL BE REPLACED BY A TROUGH EXTENDING FROM THE MAIN LOW ACROSS INDIANA EARLY THURSDAY MORNING. EXPECT THE LOW TO SHIFT NNE ACROSS LAKE HURON THURSDAY AFTERNOON...AND INTO JAMES BAY FRIDAY. THIS WILL ALLOW A TROUGH TO SETTLE ACROSS LAKE SUPERIOR THURSDAY NIGHT THROUGH FRIDAY...WHICH WILL BE REINFORCED BY A WEAK LOW SWINGING IN FROM W ONTARIO FRIDAY NIGHT INTO EARLY SATURDAY. EXPECT GUSTS NEARING 20-30KTS THURSDAY AFTERNOON THROUGH MID MORNING FRIDAY OVER MAINLY THE E HALF OF LAKE SUPERIOR. ASSISTING IN THE STRONGER WIND GUSTS WILL BE THE BROAD AREA OF HIGH PRESSURE TO BUILD ACROSS THE UPPER GREAT LAKES SATURDAY NIGHT THROUGH SUNDAY NIGHT. LOW PRESSURE ACROSS THE N AND CENTRAL PLAINS STATES WILL EXTEND A TROUGH ACROSS LAKE SUPERIOR ON MONDAY. && .HYDROLOGY... ISSUED AT 527 AM EDT WED MAY 14 2014 PERIODS OF RAIN AND SNOW ARE EXPECTED TO DEVELOP THU AND CONTINUE INTO FRI. SOME LIGHT PCPN WILL LINGER ON INTO SAT. RIGHT NOW...PCPN AMOUNTS ARE EXPECTED TO BE LIGHT ENOUGH SO THAT THERE IS LITTLE IMPACT ON AREA RIVERS/STREAMS...AND SINCE NO SIGNIFICANT PCPN IS IN THE OFFING THRU EARLY NEXT WEEK...EXPECT ALL RIVERS TO HAVE AN OVERALL DOWNWARD TREND OVER THE NEXT SEVERAL DAYS. HOWEVER...THERE ARE SOME INDICATIONS THAT PCPN AMOUNTS MAY BE HEAVIER THAN CURRENTLY EXPECTED THU/FRI OVER NRN UPPER MI. IF SO...HIGHER RIVER LEVELS WILL BE SUSTAINED AND COULD RISE SOME FRI INTO SAT. THE MAIN RIVERS OF CONCERN ARE OVER THE W HALF OF UPPER MI... INCLUDING THE STURGEON RIVER AT CHASSELL AND THE MICHIGAMME RIVER AT REPUBLIC...WITCH LAKE...AND CRYSTAL FALLS. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...KF MARINE...KF HYDROLOGY...ROLFSON
AREA FORECAST DISCUSSION
NWS BUFFALO NY
332 PM EDT WED MAY 14 2014 .SYNOPSIS... WARM AND HUMID CONDITIONS WILL REMAIN OVER WESTERN AND CENTRAL NEW YORK WITH THUNDERSTORMS DEVELOPING INLAND LATE THIS AFTERNOON AND EVENING. A SLOW MOVING COLD FRONT WILL CROSS THE REGION LATER THURSDAY AND EARLY FRIDAY WITH ADDITIONAL SHOWERS AND THUNDERSTORMS...SOME OF WHICH WILL BRING DOWNPOURS. && .NEAR TERM /THROUGH THURSDAY/... LATE AFTERNOON RADAR AND SATELLITE SHOW A BROKEN LINE OF CONVECTION FORMING UP ALONG WHAT APPEARS TO BE A COMBINATION OF THE LAKE ONTARIO BREEZE BOUNDARY AND A BACKDOOR COLD FRONT ACROSS CENTRAL NY. RAPID UPDATE AND HIGHER RESOLUTION MESOSCALE MODELS HAVE PICKED UP ON THIS AND I HAVE CHOSEN A COMBO OF HRRR AND WRF FOR THE NEAR TERM...THROUGH THE EVENING...THEN A BLEND OF WRF AND NAM12 LATER TONIGHT THROUGH FRIDAY. EXPECT MORE CONVECTION TO MOVE NORTH FROM NORTHERN PA AND ALONG THE LAKE ERIE SHORE. SOME STORMS WILL BE CAPABLE OF PRODUCING DOWNPOURS AND A QUICK QUARTER TO HALF INCH OF RAIN THIS EVENING. THE OVERALL TREND WILL BE FOR THE RAIN TO MOVE NORTH OF LAKE ONTARIO TONIGHT... THEN PLACE A WARM AND HUMID BUT CAPPED AIRMASS ACROSS THE REGION DURING MOST OF THURSDAY. THE COLD FRONT WILL EDGE IN FROM THE WEST DURING THE LATTER HALF OF THE AFTERNOON AND THROUGH THE EVENING. IT IS DURING THIS TIME THAT THE HEAVIER AND TRAINING STORMS ARE EXPECTED TO IMPACT WESTERN NY. THE HYDROLOGY SECTION FOLLOWING LATER IN THIS DISCUSSION WILL HAVE MORE DETAILS ON THE RAINFALL AMOUNTS AND IMPACTS ON FLOODING POTENTIAL. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... A CLOSED LOW ACROSS THE UPPER MIDWESTERN STATES WILL SET UP A DEEP AND MOIST SOUTHERLY FLOW ACROSS THE REGION. THIS WILL POSE A SIGNIFICANT RISK FOR FLOODING AND FLASH FLOODING THURSDAY NIGHT AND FRIDAY. OVERALL...MODEL GUIDANCE IS VERY CLOSE ON THE BIG PICTURE. THERE IS HIGH CONFIDENCE IN A PERIOD OF HEAVY RAIN MOVING ACROSS THE REGION...WITH UNCERTAINTY ONLY IN TIMING. FORECAST USES A BROAD CONSENSUS FOR THIS...WITH THE AXIS OF HEAVY RAIN LIKELY TO BE FROM BUF-ROC THURSDAY NIGHT...AND ROC-ART ON FRIDAY. FROM THIS...MOST AREAS SHOULD RECEIVE BETWEEN 1.5 AND 2 INCHES OF RAIN...WITH THE STEADIEST RAINS LIKELY TO BE ACROSS THE SOUTHERN TIER. THE CAUSE FOR THIS IS FAIRLY STRAIGHTFORWARD...WITH A SOUTHERLY 50 KT 850 MB LLJ TRANSPORTING MOISTURE (PWATS ABOUT 1.5 INCHES) FROM THE GULF INTO OUR REGION. FORECAST SOUNDINGS SHOW SOME ELEVATED INSTABILITY...WHICH WILL ADD A CONVECTIVE ELEMENT...HOWEVER THE SYNOPTIC SCALE LIFT SHOULD BRING A HEAVY RAIN TO ALL LOCATIONS WITH LOCALLY HIGHER AMOUNTS DUE TO THESE CONVECTIVE ELEMENTS. THE SLOW MOVING NATURE OF THIS WILL POTENTIALLY ALLOW FOR MULTIPLE WAVES OR TRAINING...WHICH ALSO COULD RESULT IN LOCALLY HIGHER AMOUNTS. ALTHOUGH FLOODING IS THE PRIMARY RISK...THERE WILL BE A LIMITED CHANCE FOR STRONG THUNDERSTORMS ON THURSDAY. WIND PROFILES WILL BE FAVORABLE FOR ORGANIZED CONVECTION...HOWEVER WIDESPREAD CLOUD COVER IS LIKELY TO PREVENT SURFACE BASED CONVECTION. SIGNIFICANT BREAKS OF SUNSHINE WILL HAVE TO BE MONITORED. THE UPPER LOW WILL GRADUALLY SHIFT EASTWARD...WHICH WILL PUSH A COLD FRONT THROUGH OUR REGION FRIDAY NIGHT AND BRING AN END TO THE HEAVY RAIN. EXPECT TEMPERATURES IN THE 70S AHEAD OF THIS FRONT TO DROP INTO THE UPPER 40S TO LOWER 50S ON FRIDAY. THEN ON SATURDAY TEMPERATURES WILL CONTINUE TO BE ON THE COLL SIDE...TOPPING OUT AT AROUND 60 DEGREES. THE UPPER TROF AXIS MAY SPARK A FEW SHOWERS...BUT THESE SHOULD BE BRIEF IN NATURE...POSING NO ADDITIONAL RISK FOR FLOODING. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE REGION WILL BE UNDER THE INFLUENCE OF AN UPPER LEVEL LOW FOR THE BETTER PART OF THE EXTENDED PERIOD. THIS WILL BRING BELOW NORMAL TEMPERATURES AND PERIODIC SHOWERS. ON SATURDAY NIGHT 850 MB TEMPERATURES ARE FORECAST TO BE AROUND +1 AT 850 MB...WITH WEAK RIDING PATCHY FROST IS A POSSIBILITY IN THE MOUNTAIN VALLEYS DEPENDING ON HOW MUCH CLEARING OCCURS. A CLOSED UPPER LOW IS THEN FORECAST TO DIVE ACROSS THE REGION THROUGH MONDAY WHICH WILL BRING INCREASING COVERAGE OF SHOWERS. THESE SHOULD NOT BE TERRIBLY HEAVY GIVEN TH SOURCE OF THE LOW...WITH THE MOST WIDESPREAD COVERAGE TO FOLLOW DIURNAL TRENDS AND COME DURING THE AFTERNOON HOURS. HIGHS SHOULD BE IN THE LOWER 60S SUNDAY AND MONDAY. BOTH GFS/ECMWF SLOWLY NUDGE THE UPPER LOW EASTWARD ON TUESDAY AND WEDNESDAY...WHICH WILL ALLOW A RIDGE TO BUILD ON THE BACK OF THE LOW. THIS SHOULD BRING FAIR WEATHER FOR THE PERIOD...WITH SEASONABLE TEMPERATURES WITH DAYTIME HIGHS INT HE UPPER 60S TO LOWER 70S. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... HRRR AND WRF MODELS INDICATE THAT AREAS OF CONVECTION WILL DEVELOP ALONG ILL DEFINED BOUNDARIES INLAND OF LAKES ERIE AND ONTARIO...AND A WEAK BACKDOOR COLD FRONT ACROSS CENTRAL NY. GENERALLY VFR CONDITIONS ARE EXPECTED AWAY FROM THESE BOUNDARY INDUCED STORMS...WITH TEMPORARY MVFR CONDITIONS IN THUNDERSTORMS. THE RAIN SHOULD MOVE NORTH BY MIDNIGHT WITH VFR CONDITIONS THROUGH THE NIGHT AND REMAIN SO THROUGH MID AFTERNOON ON THURSDAY. OUTLOOK... THURSDAY...VFR THROUGH MID AFTERNOON. MVFR WITH NUMEROUS SHOWERS AND THUNDERSTORMS LATE IN THE DAY. THURSDAY NIGHT AND FRIDAY...MVFR/IFR IN SHOWERS AND THUNDERSTORMS. HEAVY RAIN AT TIMES OVERNIGHT. SATURDAY...MAINLY VFR WITH A CHANCE OF SHOWERS. SUNDAY AND MONDAY...VFR IN SCATTERED SHOWERS. && .MARINE... RELATIVELY LIGHT WINDS WILL CONTINUE THROUGH THURSDAY AS A NEARLY STATIONARY FRONTAL BOUNDARY REMAINS DRAPED ACROSS THE LOWER GREAT LAKES. A COLD FRONT WILL MOVE ACROSS THE REGION THURSDAY NIGHT WITH HEAVY RAIN AND THUNDERSTORMS. WINDS AND WAVES WILL LIKELY REMAIN BELOW SMALL CRAFT CRITERIA THROUGH THE WEEKEND. && .HYDROLOGY... THERE ARE MULTIPLE HYDROLOGICAL CONCERNS FOR THE UPCOMING DAYS. THE PRIMARY RISK WILL BE FOR FLASH FLOODING. INITIALLY THIS WILL BE CONVECTIVELY DRIVEN THROUGH THURSDAY. FOR THIS PERIOD...IT WILL BE VERY DIFFICULT TO TELL EXACTLY WHERE THUNDERSTORMS WILL DEVELOP...BIT WITH A PERSISTENTLY MOIST AIRMASS IN PLACE LOCALIZED RAINFALL AMOUNTS IN EXCESS OF 2 INCHES WILL BE POSSIBLE. MEANWHILE...THERE ARE SEVERAL AREAS IN OUR CWA WHICH WILL BE PARTICULARLY VULNERABLE TO FLASH FLOODING DUE TO RECENT RAINFALL. THESE INCLUDE PORTIONS OF THE SOUTHERN TIER AND FINGER LAKES REGIONS. THERE IS INCREASING CONFIDENCE THAT ALL AREAS WILL GET A PERIOD OF HEAVY RAIN ON THURSDAY NIGHT AND FRIDAY...WITH BASIN AVERAGES BETWEEN 1.5 AND 2 INCHES. THIS HAS THE POTENTIAL TO CAUSE ADDITIONAL FLASH FLOODING...ESPECIALLY IF THUNDERSTORMS TRAIN OVER THE SAME AREAS WHICH COULD RESULT IN LOCALLY HIGHER AMOUNTS. IN ADDITION...THERE IS ALSO A RISK FOR RIVER AND CREEK FLOODING. THE CONVECTIVE NATURE OF THIS MAKES RIVER FORECASTS DIFFICULT SINCE AMOUNTS CAN VARY SIGNIFICANTLY ACROSS BASINS. EVEN SO...THE WIDESPREAD RAINFALL ON THURSDAY NIGHT AND FRIDAY HAS A GOOD CHANCE TO PUSH THE GENESEE AND ALLEGHENY RIVERS TO NEAR FLOOD STAGE. MEANWHILE THE BUFFALO AND ROCHESTER CREEKS WILL BE MORE VULNERABLE TO CONVECTION...WITH LOCALIZED RAINFALL POSSIBLY CAUSING MORE SIGNIFICANT FLOODING (OR NONE AT ALL) IN THE BUFFALO AND ROCHESTER CREEKS. THE CRESTS WILL DEPEND ON EXACTLY WHEN AND WHERE THE HEAVIEST RAIN FALLS...WHICH WILL BE DIFFICULT TO KNOW UNTIL CLOSER TO THE EVENT. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR NYZ003>005-013- 014-021. FLASH FLOOD WATCH THROUGH FRIDAY AFTERNOON FOR NYZ001-002- 010>012-019-020-085. MARINE...NONE. && $$ SYNOPSIS...WCH NEAR TERM...WCH SHORT TERM...APFFEL LONG TERM...APFFEL/LEVAN AVIATION...WCH MARINE...WCH/ZAFF HYDROLOGY...WCH
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
149 PM EDT WED MAY 14 2014 .SYNOPSIS... HIGH PRESSURE WILL PERSIST THROUGH MID WEEK...BEFORE A COLD FRONT CROSSES FROM THE WEST ON THURSDAY. A COOLER AIR MASS WILL SETTLE ACROSS THE REGION FRIDAY AND SLOWLY MODIFY WARMER THROUGH EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 115 PM EDT WEDNESDAY...PRESENT FORECAST IS RIGHT ON TRACK. THE LATEST RUNS OF THE HRRR ARE DOING A VERY GOOD JOB WITH CONVECTION DEVELOPING UPSTREAM OF THE REGION AND THAT/S THE MODEL I/VE USED AS MY TEMPLATE FOR THE ONSET OF PCPN INTO THE EVENING HOURS. AS OF 1015 AM EDT WEDNESDAY...A BAND OF LOW STRATUS DEVELOPED OVER THE NE GA...MOST OF THE UPSTATE AND THE SRN NC PIEDMONT STARTING AROUND SUNRISE. THE STRATUS IS STARTING TO MIX INTO CUMULIFORM CLOUD STREETS...THOUGH IT SHOULD REMAIN FAIRLY CLOUDY OVER THESE ZONES UNTIL AROUND NOON. SKY COVER WAS UPDATED TO REFLECT THIS. OTHERWISE...THE SHORT WAVE LIFTING OUT OF THE GULF IS STILL EXPECTED TO BRING ABUNDANT SHOWER AND TSTM ACTIVITY INTO THE REGION THIS EVENING. UNTIL THAT TIME...SOMEWHAT DRIER BNDRY LAYER AIR SHOULD INHIBIT CONVECTION FOR MOST OF THE AFTN. THE EXCEPTION IS LIKELY TO BE THE SOUTHWEST NC MTNS WHERE SOME SHOWER AND TSTM ACTIVITY IS EXPECTED TO DEVELOP THIS AFTN. AS OF DAYBREAK...STILL ALL QUIET ACROSS THE FCST AREA. ONGOING THUNDERSTORMS MOVING NWD FROM AL TO TN SHOULD STAY TO OUR WEST IN A PLUME OF BETTER MOISTURE CONVERGENCE/TRANSPORT AND WARM ADVECTION. THE NEXT 24 HOURS LOOK...INTERESTING. ONE MORE DAY OF THE BERMUDA HIGH BEFORE THINGS REALLY GO DOWNHILL IN A HURRY. THE MODELS ARE IN GOOD AGREEMENT THAT THE BALANCE OF THE DAY WILL BE QUIET ACROSS THE WESTERN CAROLINAS. FCST SOUNDINGS SHOW WARMER AIR ALOFT THAT SHOULD CUT DOWN CONSIDERABLY ON THE AMOUNT OF INSTABILITY...WHILE THE BEST FORCING/MOISTURE ADVECTION REMAINS OFF TO THE WEST THROUGH ROUGHLY THE END OF THE DAYTIME PERIOD /22Z/. THE LACK OF CONVECTION THROUGH THE DAY WILL BELIE HOW CONVECTIVELY ACTIVE THE NEXT 24 HOURS WILL BE. STORMS SHOULD ALREADY BE TAKING SHAPE TO THE SOUTH BY THE END OF THE AFTERNOON AND WILL TAKE AIM ON NORTHEAST GEORGIA AND THE BLUE RIDGE BY SUNSET. PRECIP CHANCES RAMP UP QUICKLY FROM THE SOUTH AND ALONG THE BLUE RIDGE DURING THE EVENING HOURS AS DEEP MOISTURE AND ALL MANNER OF FORCING COMES INTO PLAY. EVENTUALLY...THE FORCING AND DEEPER MOISTURE WILL SPREAD EAST OVER THE NC PIEDMONT BY SUNRISE THURSDAY. FLOODING AND SEVERE WEATHER ARE BOTH CONCERNS THROUGH SUNRISE...MAINLY OVER THE SW PART OF THE FCST AREA. ANTECEDENT CONDITIONS ARE RELATIVELY DRY ACROSS THE REGION...SO IT WOULD APPEAR THAT ANY RAIN BEFORE THE END OF THE TONIGHT PERIOD WOULD ONLY SERVE TO WET DOWN THE SOIL. HOWEVER...THE CONVECTIVE NATURE OF THE PRECIP AND THE STRONG MOISTURE TRANSPORT INTO THE S FACING ESCARPMENT SUGGEST THE POTENTIAL FOR A QUICK FEW INCHES BY MIDDAY THURSDAY. THE POTENTIAL WILL THEN STRETCH UP THE BLUE RIDGE TOWARD VIRGINIA LATER IN THE DAY. THINK IT BEST TO GO WITH A FLASH FLOOD WATCH IN THE MOST VULNERABLE/FLASHY ZONE ALONG/NEAR THE BLUE RIDGE NOW...RATHER THAN DUMPING IT OFF ON THE DAY SHIFT. AS FOR SEVERE WEATHER...WHILE IT IS ACKNOWLEDGED THAT THE BETTER RISK WILL REMAIN OFF TO OUR WEST THROUGH TONIGHT...AND THAT CONDITIONS MIGHT BE MORE FAVORABLE AGAIN AFTER SUNRISE ON THURSDAY...BOTH MODELS DEVELOP A HIGH SHEAR/LOW CAPE SCENARIO BY 12Z THURSDAY OVER NE GEORGIA AND THE WESTERN PART OF SC. THUS...IT WOULD NOT BE COMPLETELY OUT OF THE REALM OF POSSIBILITIES TO HAVE SOME SEVERE WEATHER THREAT MOVING IN FROM THE SW DURING THE PRE-DAWN HOURS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AT 300 AM EDT WEDNESDAY...A HIGH AMPLITUDE UPPER PATTERN WILL EXIST ON THURSDAY MORNING...WITH RIDGES ALONG EACH COAST...AND A TROUGH OVER THE CENTER OF THE NATION. AS AN UPPER LOW CLOSES OFF OVER THE NORTHERN PLAINS...A STRONG SHORTWAVE MOVING THROUGH THE TROUGH WILL EXIT THE MS RIVER VALLEY AND MOVE UP THE OH AND TN RIVER VALLEYS. THIS SHORTWAVE REACHES THE SOUTHERN APPALACHIANS BY FRIDAY MORNING...AND EXITS THE REGION ON FRIDAY EVENING. ANOTHER WEAKER SHORTWAVE ROUNDING THE BASE OF THE UPPER TROUGH WILL CROSS OUR AREA LATE FRIDAY NIGHT. A STRONG...SLOW MOVING COLD FRONT WILL BE OVER THE MOUNTAINS OF THE WESTERN CAROLINAS AND NE GA THURSDAY MORNING. PRONOUNCED ISENTROPIC UPGLIDE AND UPSLOPE FLOW AHEAD OF THE FRONT WILL SUPPORT ROBUST PRECIPITATION...ESPECIALLY NEAR THE SOUTH FACING BLUE RIDGE ESCARPMENT...IF CONVECTION FARTHER SOUTH ALONG THE BOUNDARY DOES NOT ROB MOISTURE FROM OUR AREA. ALTHOUGH SHEAR WILL BE RATHER STRONG...CAPE WILL BE SOMEWHAT LIMITED. NEVERTHELESS...ENOUGH INGREDIENTS APPEAR TO BE COMING TOGETHER FOR SEVERE WEATHER TO BE POSSIBLE. THE FRONT WILL EXIT OUR AREA EARLY THURSDAY EVENING...FOLLOWED BY DRYING FORM THE SW IN ITS WAKE. ANOTHER...WEAKER COLD FRONT WILL APPROACH THE MOUNTAINS FORM THE W BY FRIDAY MORNING. THIS BOUNDARY SLOWLY CROSSES THE AREA DURING THE DAY...AND MOISTURE MOVING ALONG AND BEHIND THE BOUNDARY WILL LONG OVER OUR AREA THROUGH FRIDAY NIGHT. THE BEST CHANCE FOR PRECIPITATION WITH THIS SYSTEM WILL BE IN THE NC MOUNTAINS BORDER TN WHERE UPSLOPE FLOW WILL FOLLOW THE FRONT. TEMPERATURES WILL RUN SEVERAL CATEGORIES BELOW NORMAL...AT FIRST DUE TO PRECIPITATION AND CLOUD COVER...AFTER FRONTAL PASSAGE DUE TO COLD ADVECTION. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AT 300 AM EDT WEDNESDAY...ON SATURDAY MORNING A WEAKENING UPPER LOW WILL BE LOCATED OVER CENTRAL ONTARIO...WITH AN ASSOCIATED TROUGH EXTENDING SOUTH TO THE GULF STATES. BY SUNDAY MORNING THE UPPER LOW WILL DRIFT SE OVER LAKE ERIE...WITH THE GFS CLOSING ITS LOW OFF AGAIN...WHILE THE TROUGH AXIS MOVES TO THE MID ATLANTIC AND SOUTHEAST COAST. AN UPPER RIDGE WILL AMPLIFY OVER THE MS RIVER VALLEY ON MONDAY...WHILE THE UPPER LOW...NOW CLOSED OFF IN THE ECMWF AS WELL...MOVED TO THE MID ATLANTIC COAST. BY TUESDAY THE UPPER LOW MOVES OFF THE MID ATLANTIC COAST...WHILE THE SLOWLY PROGRESSIVE UPPER RIDGE UPSTREAM REMAINS OVER THE MS RIVER VALLEY. A SECOND COLD FRONT WASHES OUT AS IT LEAVES OUR AREA EARLY SATURDAY...WITH PRECIPITATION DECREASING FORM WEST TO EAST. HIGH PRESSURE WILL SLOWLY MOVE FROM THE MID MS RIVER VALLEY ON SATURDAY...TO THE CENTRAL APPALACHIANS BY TUESDAY...THEN WEAKENS OVER THE CAROLINAS AND GA ON WEDNESDAY. MOISTURE ASSOCIATED WITH A STATIONARY FRONT IN THE SOUTHERN PLAINS WILL SPREAD EAST OVER THE SURFACE RIDGE...SENDING INCREASING CLOUDS OVER GA AND THE CAROLINAS ON SUNDAY. AS THE UPPER LOW DIVES SOUTHEAST...THE EASTERN EXTEND OF THIS CLOUD COVER IS DIVERTED TO THE SOUTH...EVEN AS THE BOUNDARY IN THE PLAINS BEGINS MOVING NORTH AS A WARM FRONT. MOISTURE ASSOCIATED WITH THE UPPER LOW DOES SPREAD SW TOWARD OUR AREA ON TUESDAY. TEMPERATURES WILL RUN SEVERAL CATEGORIES BELOW NORMAL EARLY ON...TRENDING TOWARD NORMAL BY TUESDAY AS COLD ADVECTION ABATES AND HEIGHTS RISE ALOFT. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AT KCLT...CU FIELD HAS BEEN WEAKENING OVER THE PAST COUPLE HOURS AS DRY AIR WORKS IN FROM THE SOUTH. EXPECTING SCT040 CIGS THROUGH THE EVENING HOURS. WIDESPREAD SHRA/TSTMS WILL SLOWLY SPREAD INTO THE REGION FROM THE SOUTH AFTER MIDNIGHT. LOW CIGS WILL ALSO ACCOMPANY THE SHOWERS. ATTM IT APPEARS THAT THE PCPN AND LOW CIGS WILL MOVE IN AROUND 0800 UTC. THERE WILL BE PERIODS OF TSTM ACTIVITY...THOUGH I THINK THE BEST BET FOR THUNDER WILL BE LATER THURSDAY MORNING AS THE ATMOSPHERE HEATS UP A LITTLE. IFR CIGS SHOULD LAST AT LEAST THROUGH THE MORNING HOURS ON THURSDAY. ELSEWHERE...SIMILAR CONDITIONS AS AT KCLT...EXCEPT THE CONVECTION WILL MOVE IN SEVERAL HOURS EARLIER. EXPECTING SHRA/TSTMS TO AFFECT KAND FIRST...THEN GRADUALLY SPREAD TO THE NORTH AND EAST. IFR CIGS WILL ALSO ACCOMPANY THE PCPN. CONDITIONS WILL BE SLOW TO IMPROVE ON THURSDAY AND FOR NOW I/VE KEPT IFR CIGS THROUGH 18 UTC AT ALL SITES TMRW. OUTLOOK...EXPECT VFR AGAIN FRIDAY AND SATURDAY. AN UPPER LEVEL DISTURBANCE COULD BRING A PERIOD OF MVFR CEILINGS ON SUNDAY. CONFIDENCE TABLE... 17-23Z 23-05Z 05-11Z 11-17Z KCLT HIGH 100% HIGH 93% MED 74% HIGH 88% KGSP HIGH 100% HIGH 94% MED 75% HIGH 83% KAVL HIGH 100% HIGH 93% HIGH 86% HIGH 85% KHKY HIGH 100% HIGH 100% HIGH 83% MED 73% KGMU HIGH 100% HIGH 94% HIGH 80% HIGH 85% KAND HIGH 100% MED 71% HIGH 80% HIGH 92% 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...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE THURSDAY NIGHT FOR GAZ010. NC...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE THURSDAY NIGHT FOR NCZ033-048>053-058-059-062>065-501>507-509. SC...NONE. && $$ SYNOPSIS...JAT NEAR TERM...MCAVOY/PM SHORT TERM...JAT LONG TERM...JAT AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
118 PM EDT WED MAY 14 2014 .SYNOPSIS... HIGH PRESSURE WILL PERSIST THROUGH MID WEEK...BEFORE A COLD FRONT CROSSES FROM THE WEST ON THURSDAY. A COOLER AIR MASS WILL SETTLE ACROSS THE REGION FRIDAY AND SLOWLY MODIFY WARMER THROUGH EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 115 PM EDT WEDNESDAY...PRESENT FORECAST IS RIGHT ON TRACK. THE LATEST RUNS OF THE HRRR ARE DOING A VERY GOOD JOB WITH CONVECTION DEVELOPING UPSTREAM OF THE REGION AND THAT/S THE MODEL I/VE USED AS MY TEMPLATE FOR THE ONSET OF PCPN INTO THE EVENING HOURS. AS OF 1015 AM EDT WEDNESDAY...A BAND OF LOW STRATUS DEVELOPED OVER THE NE GA...MOST OF THE UPSTATE AND THE SRN NC PIEDMONT STARTING AROUND SUNRISE. THE STRATUS IS STARTING TO MIX INTO CUMULIFORM CLOUD STREETS...THOUGH IT SHOULD REMAIN FAIRLY CLOUDY OVER THESE ZONES UNTIL AROUND NOON. SKY COVER WAS UPDATED TO REFLECT THIS. OTHERWISE...THE SHORT WAVE LIFTING OUT OF THE GULF IS STILL EXPECTED TO BRING ABUNDANT SHOWER AND TSTM ACTIVITY INTO THE REGION THIS EVENING. UNTIL THAT TIME...SOMEWHAT DRIER BNDRY LAYER AIR SHOULD INHIBIT CONVECTION FOR MOST OF THE AFTN. THE EXCEPTION IS LIKELY TO BE THE SOUTHWEST NC MTNS WHERE SOME SHOWER AND TSTM ACTIVITY IS EXPECTED TO DEVELOP THIS AFTN. AS OF DAYBREAK...STILL ALL QUIET ACROSS THE FCST AREA. ONGOING THUNDERSTORMS MOVING NWD FROM AL TO TN SHOULD STAY TO OUR WEST IN A PLUME OF BETTER MOISTURE CONVERGENCE/TRANSPORT AND WARM ADVECTION. THE NEXT 24 HOURS LOOK...INTERESTING. ONE MORE DAY OF THE BERMUDA HIGH BEFORE THINGS REALLY GO DOWNHILL IN A HURRY. THE MODELS ARE IN GOOD AGREEMENT THAT THE BALANCE OF THE DAY WILL BE QUIET ACROSS THE WESTERN CAROLINAS. FCST SOUNDINGS SHOW WARMER AIR ALOFT THAT SHOULD CUT DOWN CONSIDERABLY ON THE AMOUNT OF INSTABILITY...WHILE THE BEST FORCING/MOISTURE ADVECTION REMAINS OFF TO THE WEST THROUGH ROUGHLY THE END OF THE DAYTIME PERIOD /22Z/. THE LACK OF CONVECTION THROUGH THE DAY WILL BELIE HOW CONVECTIVELY ACTIVE THE NEXT 24 HOURS WILL BE. STORMS SHOULD ALREADY BE TAKING SHAPE TO THE SOUTH BY THE END OF THE AFTERNOON AND WILL TAKE AIM ON NORTHEAST GEORGIA AND THE BLUE RIDGE BY SUNSET. PRECIP CHANCES RAMP UP QUICKLY FROM THE SOUTH AND ALONG THE BLUE RIDGE DURING THE EVENING HOURS AS DEEP MOISTURE AND ALL MANNER OF FORCING COMES INTO PLAY. EVENTUALLY...THE FORCING AND DEEPER MOISTURE WILL SPREAD EAST OVER THE NC PIEDMONT BY SUNRISE THURSDAY. FLOODING AND SEVERE WEATHER ARE BOTH CONCERNS THROUGH SUNRISE...MAINLY OVER THE SW PART OF THE FCST AREA. ANTECEDENT CONDITIONS ARE RELATIVELY DRY ACROSS THE REGION...SO IT WOULD APPEAR THAT ANY RAIN BEFORE THE END OF THE TONIGHT PERIOD WOULD ONLY SERVE TO WET DOWN THE SOIL. HOWEVER...THE CONVECTIVE NATURE OF THE PRECIP AND THE STRONG MOISTURE TRANSPORT INTO THE S FACING ESCARPMENT SUGGEST THE POTENTIAL FOR A QUICK FEW INCHES BY MIDDAY THURSDAY. THE POTENTIAL WILL THEN STRETCH UP THE BLUE RIDGE TOWARD VIRGINIA LATER IN THE DAY. THINK IT BEST TO GO WITH A FLASH FLOOD WATCH IN THE MOST VULNERABLE/FLASHY ZONE ALONG/NEAR THE BLUE RIDGE NOW...RATHER THAN DUMPING IT OFF ON THE DAY SHIFT. AS FOR SEVERE WEATHER...WHILE IT IS ACKNOWLEDGED THAT THE BETTER RISK WILL REMAIN OFF TO OUR WEST THROUGH TONIGHT...AND THAT CONDITIONS MIGHT BE MORE FAVORABLE AGAIN AFTER SUNRISE ON THURSDAY...BOTH MODELS DEVELOP A HIGH SHEAR/LOW CAPE SCENARIO BY 12Z THURSDAY OVER NE GEORGIA AND THE WESTERN PART OF SC. THUS...IT WOULD NOT BE COMPLETELY OUT OF THE REALM OF POSSIBILITIES TO HAVE SOME SEVERE WEATHER THREAT MOVING IN FROM THE SW DURING THE PRE-DAWN HOURS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AT 300 AM EDT WEDNESDAY...A HIGH AMPLITUDE UPPER PATTERN WILL EXIST ON THURSDAY MORNING...WITH RIDGES ALONG EACH COAST...AND A TROUGH OVER THE CENTER OF THE NATION. AS AN UPPER LOW CLOSES OFF OVER THE NORTHERN PLAINS...A STRONG SHORTWAVE MOVING THROUGH THE TROUGH WILL EXIT THE MS RIVER VALLEY AND MOVE UP THE OH AND TN RIVER VALLEYS. THIS SHORTWAVE REACHES THE SOUTHERN APPALACHIANS BY FRIDAY MORNING...AND EXITS THE REGION ON FRIDAY EVENING. ANOTHER WEAKER SHORTWAVE ROUNDING THE BASE OF THE UPPER TROUGH WILL CROSS OUR AREA LATE FRIDAY NIGHT. A STRONG...SLOW MOVING COLD FRONT WILL BE OVER THE MOUNTAINS OF THE WESTERN CAROLINAS AND NE GA THURSDAY MORNING. PRONOUNCED ISENTROPIC UPGLIDE AND UPSLOPE FLOW AHEAD OF THE FRONT WILL SUPPORT ROBUST PRECIPITATION...ESPECIALLY NEAR THE SOUTH FACING BLUE RIDGE ESCARPMENT...IF CONVECTION FARTHER SOUTH ALONG THE BOUNDARY DOES NOT ROB MOISTURE FROM OUR AREA. ALTHOUGH SHEAR WILL BE RATHER STRONG...CAPE WILL BE SOMEWHAT LIMITED. NEVERTHELESS...ENOUGH INGREDIENTS APPEAR TO BE COMING TOGETHER FOR SEVERE WEATHER TO BE POSSIBLE. THE FRONT WILL EXIT OUR AREA EARLY THURSDAY EVENING...FOLLOWED BY DRYING FORM THE SW IN ITS WAKE. ANOTHER...WEAKER COLD FRONT WILL APPROACH THE MOUNTAINS FORM THE W BY FRIDAY MORNING. THIS BOUNDARY SLOWLY CROSSES THE AREA DURING THE DAY...AND MOISTURE MOVING ALONG AND BEHIND THE BOUNDARY WILL LONG OVER OUR AREA THROUGH FRIDAY NIGHT. THE BEST CHANCE FOR PRECIPITATION WITH THIS SYSTEM WILL BE IN THE NC MOUNTAINS BORDER TN WHERE UPSLOPE FLOW WILL FOLLOW THE FRONT. TEMPERATURES WILL RUN SEVERAL CATEGORIES BELOW NORMAL...AT FIRST DUE TO PRECIPITATION AND CLOUD COVER...AFTER FRONTAL PASSAGE DUE TO COLD ADVECTION. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AT 300 AM EDT WEDNESDAY...ON SATURDAY MORNING A WEAKENING UPPER LOW WILL BE LOCATED OVER CENTRAL ONTARIO...WITH AN ASSOCIATED TROUGH EXTENDING SOUTH TO THE GULF STATES. BY SUNDAY MORNING THE UPPER LOW WILL DRIFT SE OVER LAKE ERIE...WITH THE GFS CLOSING ITS LOW OFF AGAIN...WHILE THE TROUGH AXIS MOVES TO THE MID ATLANTIC AND SOUTHEAST COAST. AN UPPER RIDGE WILL AMPLIFY OVER THE MS RIVER VALLEY ON MONDAY...WHILE THE UPPER LOW...NOW CLOSED OFF IN THE ECMWF AS WELL...MOVED TO THE MID ATLANTIC COAST. BY TUESDAY THE UPPER LOW MOVES OFF THE MID ATLANTIC COAST...WHILE THE SLOWLY PROGRESSIVE UPPER RIDGE UPSTREAM REMAINS OVER THE MS RIVER VALLEY. A SECOND COLD FRONT WASHES OUT AS IT LEAVES OUR AREA EARLY SATURDAY...WITH PRECIPITATION DECREASING FORM WEST TO EAST. HIGH PRESSURE WILL SLOWLY MOVE FROM THE MID MS RIVER VALLEY ON SATURDAY...TO THE CENTRAL APPALACHIANS BY TUESDAY...THEN WEAKENS OVER THE CAROLINAS AND GA ON WEDNESDAY. MOISTURE ASSOCIATED WITH A STATIONARY FRONT IN THE SOUTHERN PLAINS WILL SPREAD EAST OVER THE SURFACE RIDGE...SENDING INCREASING CLOUDS OVER GA AND THE CAROLINAS ON SUNDAY. AS THE UPPER LOW DIVES SOUTHEAST...THE EASTERN EXTEND OF THIS CLOUD COVER IS DIVERTED TO THE SOUTH...EVEN AS THE BOUNDARY IN THE PLAINS BEGINS MOVING NORTH AS A WARM FRONT. MOISTURE ASSOCIATED WITH THE UPPER LOW DOES SPREAD SW TOWARD OUR AREA ON TUESDAY. TEMPERATURES WILL RUN SEVERAL CATEGORIES BELOW NORMAL EARLY ON...TRENDING TOWARD NORMAL BY TUESDAY AS COLD ADVECTION ABATES AND HEIGHTS RISE ALOFT. && .AVIATION /17Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...VFR THROUGH THE DAYLIGHT HOURS. EXPECT ONLY HIGH CLOUDS THROUGH THE MORNING...WITH SOME CU DEVELOPMENT IN THE AFTERNOON AND INCREASING MID/HIGH CLOUDS. A LIGHT SOUTH WIND WILL PICK UP BY MIDDAY AND MIGHT BE GUSTY AT TIMES IN THE AFTERNOON. THE WIND WILL START BACKING A BIT SE BY SUNSET. NOT LOOKING LIKE ANY SHOWER OR THUNDERSTORM ACTIVITY WILL DEVELOP BEFORE SUNSET. BUT...THE WHEELS FALL OFF AFTER THAT. EXPECT A RAPID ONSET OF CONVECTIVE PRECIP MOVING UP FROM THE SOUTH DURING THE EVENING HOURS INTO THE WESTERN CAROLINAS. THE INITIAL ACTIVITY WILL HAVE A FOCUS MORE TOWARD THE BLUE RIDGE AND MOUNTAINS...THUS HAVE KEPT THE THUNDERSTORMS LIMITED WITH A PROB30 IN THIS ISSUANCE THROUGH THE EVENING. CERTAINLY... CONDITIONS WILL FURTHER DETERIORATE AFTER MIDNIGHT WEDNESDAY NIGHT...WITH MVFR PREVAILING VIS/CEILING. THIS COULD EASILY BE IFR AFTER 08Z...AND THIS WILL BE HANDLED IN A TEMPO GROUP. ELSEWHERE...MTN VALLEY FOG SHOULD BURN OFF BY 13Z OR SO ONCE AGAIN. LOW END MVFR CIGS HAVE RAPIDLY DEVELOPED OVER NE GA AND THE WRN UPSTATE. THE LLVL FLOW IS QUITE WEAK...BUT CONSIDERING HOW RAPIDLY THE CIGS ARE INCREASING...WE SHOULD SEE MVFR CONDITIONS FOR THE NEXT 2 TO 3 HOURS AT THE UPSTATE SITES. WINDS INCREASE IN SPEED FOR THE AFTERNOON. THINK THE BALANCE OF THE DAY WILL BE DRY...BUT IN THE EARLY EVENING EXPECT TO SEE CONVECTION FIRING OVER GA TAKING AIM ON THE BLUE RIDGE AND MTNS. THERE COULD BE A RAPID ONSET OF MVFR CEILING IN THE EVENING WITH THUNDERSTORMS MOVING UP FROM THE SOUTH AROUND SUNSET OR SHORTLY THEREAFTER. ALL THE TAFS WILL FEATURE A PERIOD OF PROB30 THUNDERSTORMS...FOLLOWED BY A TEMPO FOR IFR IN THUNDERSTORMS BEFORE THE END OF THE PERIOD. OUTLOOK...ON THURSDAY A SLOW MOVING COLD FRONT WILL YIELD A BETTER CHANCE OF RESTRICTIONS IN PROLONGED PRECIPITATION AND THUNDERSTORMS. EXPECT VFR AGAIN FRIDAY AND SATURDAY. AN UPPER LEVEL DISTURBANCE COULD BRING A PERIOD OF MVFR CEILING ON SUNDAY. CONFIDENCE TABLE... 17-23Z 23-05Z 05-11Z 11-17Z KCLT HIGH 100% HIGH 93% MED 74% HIGH 88% KGSP HIGH 100% HIGH 94% MED 75% HIGH 83% KAVL HIGH 100% HIGH 93% HIGH 86% HIGH 85% KHKY HIGH 100% HIGH 100% HIGH 83% MED 73% KGMU HIGH 100% HIGH 94% HIGH 80% HIGH 85% KAND HIGH 100% MED 71% HIGH 80% HIGH 92% 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...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE THURSDAY NIGHT FOR GAZ010. NC...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE THURSDAY NIGHT FOR NCZ033-048>053-058-059-062>065-501>507-509. SC...NONE. && $$ SYNOPSIS...JAT NEAR TERM...MCAVOY/PM SHORT TERM...JAT LONG TERM...JAT AVIATION...MCAVOY/PM
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1127 AM MDT WED MAY 14 2014 .UPDATE... ISSUED AT 928 AM MDT WED MAY 14 2014 NO CHANGES MADE IN FORECAST. ALL IS ON TRACK. WEAK COLD FRONT ACROSS S CNTRL SD TO THE SRN BLACK HILLS...THENCE NW WARD INTO SE MT. THE FRONT IS MARKED BY SOME CUMULUS CONVECTION ON VSBL SAT AND BY WEAK Q-VECTOR CONVERGENCE ON NAM 700 MB. AT SURFACE A ZONE OF CONFLUENCE WITH SOME THETAE GRADIENT MARKS THE FRONT. CONVECTION IS ALSO SEEN OVER THE BLACK HILLS AND PORTIONS OF CAMPBELL COUNTY. THESE ARE FAVORED AREAS FOR SCATTERED SHOWERS AND ISOLD TSTMS TO DVLP THIS AFTN. HRRR MODEL IS BEGINNING TO PICK UP ON THIS. && .SHORT TERM...TODAY THROUGH THURSDAY NIGHT ISSUED AT 235 AM MDT WED MAY 14 2014 08Z SURFACE ANALYSIS HAD WEAK COOL FRONT/TROUGH FROM NORTH CENTRAL MT TO THE SD/ND BORDER TO NORTHERN WI. FEATURE BEING DRIVEN BY WEAK SHORTWAVE NOTED ON WATER VAPOUR OVER EASTERN MT. AREA RADARS SHOWING SOME VIRGA/SPRINKLES. PATTERN WILL REMAIN LARGELY UNCHANGED THROUGH THURSDAY WITH UPPER RIDGE OVER THE WESTERN US AND TROUGH OVER THE EASTERN HALF OF THE COUNTRY...NORTHWEST FLOW ALOFT OVER THE CWA. TODAY/TONIGHT...BOUNDARY WILL SHIFT SOUTH/WEST AND STALL OVER NORTHEAST WY INTO CENTRAL NE. EARLY MORNING VIRGA/SPRINKLES WILL QUICKLY EXIT THE CWA. DIURNAL HEATING WILL RESULT IN STEEP LAPSE RATES AGAIN THIS AFTERNOON WITH SBCAPE VALUES AROUND 100J/KG. INTERSECTION OF TERRAIN AND WEAK BOUNDARY SHOULD BE SUFFICIENT FOR LOW COVERAGE SHRA/STRAY TS THIS AFTERNOON/EVENING. ACTIVITY WILL HAVE A DIURNAL MINIMUM OVERNIGHT. BREEZY SPOTS EXPECTED TODAY WITH WEAK BOUNDARY LAYER COLD AIR ADVECTION AND 15-20KT 850MB WINDS. TEMPERATURES WILL BE NEAR GUIDANCE. THURSDAY...CYCLONIC FLOW CONTINUES WITH STEEP LOW LEVEL LAPSE RATES. RESULT WILL BE A FEW DIURNAL SHRA OVER THE WEST THURSDAY AFTERNOON. BOTH NAM/GFS NOW SHOWING A BETTER ORGANIZED SHORTWAVE DROPPING INTO THE CWA FOR THURSDAY NIGHT...SO HAVE RAISED POPS TO ACCOUNT. TEMPERATURES WILL BE NEAR GUIDANCE. && .LONG TERM...FRIDAY THROUGH TUESDAY ISSUED AT 235 AM MDT WED MAY 14 2014 NORTHWEST FLOW WILL CONTINUE THROUGH THE END OF THE WEEK WITH FAST MOVING UPPER DISTURBANCES AND A NEARLY STATIONARY FRONTAL BOUNDARY OVER THE HIGH PLAINS. THIS WILL RESULT IN NEAR DAILY CHANCES FOR SHOWERS...ESPECIALLY OVER NORTHEAST WYOMING AND FAR WESTERN SOUTH DAKOTA. SLIGHTLY BELOW AVERAGE TEMPS ARE EXPECTED THROUGH THE END OF THE WEEK. AN UPPER TROUGH/CUT OFF LOW IS PROGGED TO DEVELOP EARLY NEXT WEEK OVER THE FAR WRN CONUS. UPPER FLOW WOULD THEN BECOME MORE SWRLY WITH WARM AND MOIST AIR ADVECTING IN FROM THE S/SE. THIS WILL INCREASE CHANCES FOR THUNDERSTORMS FOR THE FIRST HALF OF NEXT WEEK ALONG WITH NEAR TO SLIGHTLY ABOVE AVERAGE TEMPERATURES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY) ISSUED AT 1114 AM MDT WED MAY 14 2014 FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING ISSUED AT 452 AM MDT WED MAY 14 2014 ISOLD -SHRA/-TSRA WILL BE POSSIBLE THIS AFTERNOON INTO THE EVENING OVER NORTHEAST WY AND FAR WESTERN SD. SOME -SHSN WILL BE POSSIBLE LATE...MAINLY OVER THE BLKHLS. -SHRA CHANCES WILL CONTINUE INTO THURSDAY MORNING. BREEZY NWRLY WINDS OVER PTNS OF THE SD PLAINS WILL CONTINUE THIS AFTERNOON THOUGH WILL DIMINISH TONIGHT. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ UPDATE...BARBER SHORT TERM...HELGESON LONG TERM...13 AVIATION...77
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
148 PM EDT WED MAY 14 2014 .SYNOPSIS... SLOW MOVING COLD FRONT OVER THE OHIO/TENNESSEE VALLEYS TODAY WILL SHIFT EAST TO THE MOUNTAINS LATE TONIGHT. A COUPLE OF WAVES OF LOW PRESSURE ALONG IT WILL HINDERS ITS EASTWARD PROGRESSION UNTIL THE LAST WAVE MOVES ACROSS THURSDAY NIGHT. COOLER AIR ASSOCIATED WITH THE UPPER TROUGH WILL ARRIVE FRIDAY INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 105 PM EDT WEDNESDAY... EXPANDED FLOOD WATCH NORTH ALONG THE BLUE RIDGE AND WEST BACK TO SOUTHEAST WEST VIRGINIA TO MATCH UP WITH LOWER FFG. CONVECTION DEVELOP THIS AFTERNOON ALONG THE BACKDOOR FRONTAL BOUNDARY AND CONVERGENCE ZONE BACK TO COLD FRONT. MORE CHANGES THIS AFTERNOON... AS OF 1017 AM EDT WEDNESDAY... BACKDOOR FRONT HAS PUSHED SOUTH INTO NORTHEAST PORTIONS OF FORECAST AREA THIS MORNING...WHILE COLD FRONT APPROACHES FROM THE WEST. SATELLITE IMAGES SHOWED AREA OF LOW CLOUDS AND FOG ACROSS NORTHEAST CORNER. QUESTIONS REMAIN ON HOW FAST THE LOW CLOUDS MIX OR SCATTERED OUT THIS MORNING. ADJUST CLOUD COVER FOR THIS MORNING INTO THIS AFTERNOON. HRRR THIS MORNING GENERATES CONVECTION ALONG THE CONVERGENCE ZONE STARTING AFTER 16Z MAINLY NORTH OF HIGHWAY 460. THIS MORNINGS RNK SOUNDING INDICATED THAT PWATS HAD CLIMB TO AROUND ONE INCH AND CAPES UP TO 1500 TO 2000 J/KG ARE POSSIBLE THIS AFTERNOON. EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP THIS AFTERNOON WITH DIFFERENTIAL HEATING...LIFT AND ADD MOISTURE. ISOLATED STORMS WITH STRONG UPDRAFTS ARE POSSIBLE THIS AFTERNOON WITH THE POTENTIAL FOR DAMAGING WINDS AND HAIL. THE SWODY1 OUTLOOK HAS PLACED THE SLIGHT RISK TO OUR NORTH AND WEST FOR THIS AFTERNOON. MODIFIED TEMPERATURES AND DEW POINTS ACCORDING TO LATEST TRENDS AND HELD ON TO FORECAST HIGHS FOR THIS AFTERNOON. WILL MAKE MORE CHANGES LATER THIS AFTERNOON. AS OF 650 AM EDT WEDNESDAY... ADJUSTMENTS THIS MORNING WERE MADE TO SKY COVER...NAMELY THE NE CWA WHERE LOW CIGS AND FOG WERE ADVECTING TOWARD LYH. THINK ONCE SUN COMES UP THIS WILL HALT THE PROGRESSION TO ABOUT LYH THEN SHOULD SEE LOW CLOUDS SCATTER OUT. OTHERWISE STILL MAINLY SEEING ISOLATED SHOWERS WEST OF OUR CWA OVER ERN KY AND CENTRAL WV. PREVIOUS DISCUSSION FROM 400 AM TODAY... FORECAST CHALLENGE WILL BE COVERAGE OF SHOWERS AND STORMS TODAY BEFORE MAIN THRUST OF MOISTURE AND LIFT ARRIVE AFTER MIDNIGHT TONIGHT FROM THE SOUTHWEST. LATEST MODELS SHOWING A WEAK VORT LOBE MOVING FROM SOUTHWEST TO NORTHEAST TODAY ACROSS THE AREA...MAINLY IN THE 12Z-18Z TIME FRAME. THIS WILL HAVE SOME INFLUENCE ON PRECIP THREAT...BUT AGAIN THE OVERALL COVERAGE APPEARS TO LESSEN PER LATEST RUNS. THE MODELS ALL AGREE THAT THE NW CWA HAS THE BEST THREAT WITH LESS OF THE CHANCE OVER THE SOUTHEAST CWA. WILL FOLLOW THIS THINKING AND KEEP IN THE HIGH CHANCE IN THE GREENBRIER TO BATH/SOUTHERN SHENANDOAH VALLEY...SOUTH TOWARD ROANOKE/LYNCHBURG WITH SMALL CHANCE TO ISOLATED SOUTH OF HIGHWAY 460. EXPECTING ANOTHER WARM DAY BUT THE UPPER RIDGE SHIFTS EAST. THE RECORDS TODAY MAY NOT BE AS ATTAINABLE EXCEPT PERHAPS BLACKSBURG DEPENDING ON CLOUD COVER FROM THE CONVECTION UPSTREAM. SEE CLIMATE SECTION BELOW FOR RECORDS AT ALL OUR CLIMATE SITES. RUNNING WITH HIGHS FROM UPPER 70S-LOWER 80S NC MTNS-PORTIONS OF FAR SW VA/SE WV...TO MID 80S NEW RIVER VALLEY-ROANOKE-LYNCHBURG...AND AROUND 90 SOUTHSIDE VA INTO THE NC PIEDMONT. THERE WILL BE SOME SUBSIDENCE IN THE AFTERNOON BEHIND WEAK VORT...SO EXPECT A LULL IN THE SHOWERS AFTER 4 PM INTO THIS EVENING...BEFORE NEXT STRONG WAVE WORKS IN AHEAD OF THE FRONT OVERNIGHT. MODELS FAVOR THE SOUTHERN BLUE RIDGE GETTING THE SHOWERS AND ISOLATED STORMS AFTER MIDNIGHT AND WORKING NORTHEAST TO THE BLUE RIDGE OF VA/SE WV BY MORNING...MAYBE AS FAR EAST AS A LYH-DAN LINE. GIVEN THE HIGH PWATS RUNNING ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL THREAT OF FLASH FLOODING FROM HEAVY DOWNPOURS MAY START AS EARLY AS PREDAWN IN THE SOUTHWEST CWA. THEREFORE A FLASH FLOOD WATCH HAS BEEN ISSUED FOR THE SOUTHERN BLUE RIDGE AS FAR NORTH AS ROANOKE. THIS WILL RUN INTO LATE THURSDAY NIGHT. LOWS TONIGHT STAY MUGGY WITH UPPER 50S TO LOWER 60S MOUNTAINS...TO MID 60S ACROSS THE SOUTHSIDE OF VA INTO THE NC PIEDMONT...FOOTHILLS. && .SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... AS OF 345 AM EDT WEDNESDAY... IMPRESSIVE RAIN PRODUCING SYSTEM IS STILL SLATED TO MOVE INTO AND THROUGH THE AREA THURSDAY AND THURSDAY NIGHT. THE DRIVING FEATURES BEHIND OUR RAIN WILL BE A HIGHLY AMPLIFIED LONG WAVE TROUGH AND ASSOCIATED SURFACE COLD FRONT MAKING GRADUAL PROGRESS EASTWARD OF THE MISSISSIPPI RIVER VALLEY WITH VERY ABUNDANT MOISTURE AT THE SURFACE...LOW AND MID LEVELS OF THE ATMOSPHERE. WHILE THERE COULD BE SOME ISOLATED STRONG STORMS AHEAD OF THE MAIN FRONT...THE EXCESSIVE MOISTURE WILL QUICKLY ALLOW THE COLUMN TO SATURATE AND GREATLY REDUCE THE POTENTIAL FOR DRY AIR ALOFT TO CONTRIBUTE TO INCREASING THE CAPE VALUES. IN ADVANCE OF THE FRONT...LOW LEVEL FLOW WILL BE LONGITUDINAL AND PARALLEL TO THE MAIN UPPER TROUGH...AND THUS ALLOW FOR A SLOW PROGRESSION EASTWARD...ALLOWING PLENTY OF TIME FOR TRAINING CONVECTION TO PRODUCE HEAVY RAINFALL. THE IMPACT OF UPSLOPE ALONG THE BLUE RIDGE WILL ADD TO THIS FACTOR...AND IN THE SHORT TERM...THIS IS THE AREA OF GREATEST CONCERN. WOULD NOT BE SURPRISED AT THE END OF THE EVENT IF RAINFALL REPORTS FROM ALONG THE BLUE RIDGE TOP FOUR INCHES. GIVEN THIS AND IN COLLABORATION WITH THE GSP OFFICE...WE ARE POSTING A FLASH FLOOD WATCH FOR AREAS NEAR THE BLUE RIDGE SOUTH OF THE ROANOKE RIVER FROM MIDNIGHT TONIGHT THROUGH 600 AM FRIDAY. THIS SHOULD BE A GOOD START WHAT MAY BE ADDITIONAL WATCHES BASED UPON LATER COORDINATION WITH NEIGHBORING OFFICES AND THE LATEST GUIDANCE AS IT BECOMES AVAILABLE TODAY. FRIDAY INTO SATURDAY NIGHT...WHILE THE FRONT WILL BE TO OUR EAST...THE PARENT UPPER LOW/TROUGH WILL PROGRESS INTO AND OVER THE AREA. THIS WILL BRING AN ELEVATED COOL POOL OVER THE AREA...AND WE MAY SEE SOME ISOLATED SHOWERS ACROSS THE WESTERN PARTS OF THE AREA. ALSO...NOTABLY COOLER AIR WILL ARRIVE ACROSS THE REGION. OVERNIGHT LOWS IN THE LOWER 40S WILL BE COMMON ACROSS THE MOUNTAINS WITH MID TO UPPER 40S ACROSS THE PIEDMONT. && .LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 325 PM EDT TUESDAY... LONG WAVE TROF WILL GRADUALLY FILL AND LIFT NORTHEAST DURING THE MEDIUM RANGE AS SERIES OF SHORTWAVES ROTATE EAST THROUGH THE UPPER FLOW. THE 12Z ECMWF WAS LESS ROBUST COMPARED TO THE 00Z RUN WITH SHORTWAVE AND ASSOCIATED PRECIPITATION WITH THIS WAVE SUNDAY INTO MONDAY. IN ANY CASE...COLD AIR ALOFT IN PROXIMITY TO UPPER TROF COUPLED WITH DAYTIME SOLAR HEATING SHOULD BE SUFFICIENT TO SUPPORT DEVELOPMENT OF DIURNALLY DRIVEN SHOWERS..ESPECIALLY ACROSS THE WESTERN UPSLOPE LOCATIONS OF THE APPALACHIANS. WILL KEEP A DAILY THREAT FOR WIDELY SCATTERED TO SCATTERED SHOWERS THROUGH MUCH OF THE LONG TERM PERIOD...ALTHOUGH OVERALL TOTAL PRECIPITATION AMOUNTS SHOULD REMAIN LOCALIZED...AND LIMITED IN DURATION IN ANY PARTICULAR LOCATION. DEEPER SUBSIDENCE BUILDS IN EARLY NEXT WEEK AS THE UPPER LOW SHIFTS EAST. THE INFLUENCE OF THE SLOWLY DEPARTING UPPER TROUGH SHOULD HOLD TEMPERATURES NEAR NORMAL FOR MOST OF THE PERIOD...WITH HIGHS GENERALLY FROM THE MID 60S TO THE MID 70S. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AS OF 140 PM EDT WEDNESDAY... LOW CLOUDS IN THE NORTHEAST FINALLY MIXING OUT DURING THE NEXT COUPLE OF HOURS. SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING THIS AFTERNOON NEAR THE BACKDOOR FRONTAL BOUNDARY AND COLD FRONT TO OUR WEST IN OHIO VALLEY. LOOKS LIKE COVERAGE OF SHRA/TSRA WILL BE NORTH OF A LINE FROM BLF-BCB-ROA-DAN...SO HAVE VCTS IN AT TIMES THIS AFTERNOON. COVERAGE OF STORMS WILL BE LESS ACROSS AIRPORTS IN NORTH CAROLINA THIS AFTERNOON. THE CONVECTION WEAKENS AND EXITS THIS EVENING...BEFORE THE NEXT STRONGER UPPER SHORTWAVE MOVES IN LATE FROM THE SOUTHWEST. PROBLEM SEEMS TO BE WHETHER WE GET FOG FORMATION OVERNIGHT BEFORE CLOUDS ROLL IN AND IMPEDE IT. PATCHY FOG MAY FORM OVERNIGHT ESPECAILLY WHERE HEAVY RAIN FALLS WITH THUNDERSTORMS. ANOTHER ROUND OF SHOWERS AND ISOLATED STORMS SHOULD MAKE IT BACK INTO THE BLF/LWB/BCB AREAS THURSDAY MORNING...WITH MVFR VSBYS. EXPECT TO SEE BETTER THREAT FOR SHOWERS AND STORMS THURSDAY AFTERNOON INTO THURSDAY NIGHT WITH SUB VFR LIKELY IN HEAVIER DOWNPOURS. COLD FRONT IS PROGGED TO CROSS THE MOUNTAINS THURSDAY AFTERNOON EXITING THE PIEDMONT FRIDAY MORNING. MEDIUM TO LOW CONFIDENCE IN CEILINGS AND VISIBILITIES DURING TAF PERIOD. MEDIUM CONFIDENCE IN WIND FORECAST AT THE TAF SITES. UPPER LEVEL SYSTEM OVER THE GREAT LAKES FRIDAY WILL KEEP THE THREAT OF SHOWERS AROUND IN THE MOUNTAINS WITH UNDER VFR POSSIBLE AT BLF/LWB. SHOULD CLEAR OUT EAST OF THE MTNS AFTER FRIDAY BUT POTENTIAL FOR SHOWERS STAYS WITH US INTO THE WEEKEND AS WE STAY NEAR THE UPPER LEVEL SLOW MOVING LOW PRESSURE SYSTEM. && .HYDROLOGY... FLASH FLOOD WATCH IN EFFECT FOR THE SOUTHERN BLUE RIDGE AS FAR NORTH AS ROANOKE. MODELS AGREE THAT COPIOUS AMOUNTS OF MOISTURE WITH PWATS 2+ SD ABOVE NORMAL ALONG WITH A SLOW MOVING FRONT AND STRONG SE FLOW WILL PRODUCE TRAINING OF HEAVY RAIN. OVERALL POTENTIAL IS HIGH FOR FLASH FLOODING ALONG THE BLUE RIDGE. WILL AWAIT ANOTHER RUN OF MODELS PER COORDINATION WITH NEIGHBORING WFOS BEFORE EXPANDING THE WATCH. AS FAR AS MAIN STEM RIVERS...ENSEMBLES SUGGEST CHANCE OF MINOR FLOODING WITH POTENTIAL FOR MODERATE FLOODING ACROSS THE GREENBRIER AT ALDERSON. WILL SEE HOW THE RAIN PLAYS OUT FOR THIS. ATTM...WE ARE FORECASTING AN AVERAGE OF 1-3 INCHES OF RAIN...HIGHEST ALONG THE BLUE RIDGE WHERE UP TO 5 INCHES COULD OCCUR. && .CLIMATE... ANOTHER WARM DAY BUT RECORD HIGHS MAY BE SAFE...EXCEPT PERHAPS BLACKSBURG AS UPPER RIDGE SHIFTS EAST. SITE..........RECORDS/YEAR ROANOKE.......93/1956 LYNCHBURG.....92/1956 DANVILLE......95/1956 BLACKSBURG....86/2000 BLUEFIELD.....86/1985 LEWISBURG.....84/1985 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLASH FLOOD WATCH FROM MIDNIGHT EDT TONIGHT THROUGH LATE THURSDAY NIGHT FOR VAZ010>020-022>024-032>035. NC...FLASH FLOOD WATCH FROM MIDNIGHT EDT TONIGHT THROUGH LATE THURSDAY NIGHT FOR NCZ001>003-018-019. WV...FLASH FLOOD WATCH FROM MIDNIGHT EDT TONIGHT THROUGH LATE THURSDAY NIGHT FOR WVZ042>045. && $$ SYNOPSIS...WP NEAR TERM...KK/WP SHORT TERM...DS LONG TERM...KK AVIATION...KK/WP HYDROLOGY...WP CLIMATE...WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
108 PM EDT WED MAY 14 2014 .SYNOPSIS... SLOW MOVING COLD FRONT OVER THE OHIO/TENNESSEE VALLEYS TODAY WILL SHIFT EAST TO THE MOUNTAINS LATE TONIGHT. A COUPLE OF WAVES OF LOW PRESSURE ALONG IT WILL HINDERS ITS EASTWARD PROGRESSION UNTIL THE LAST WAVE MOVES ACROSS THURSDAY NIGHT. COOLER AIR ASSOCIATED WITH THE UPPER TROUGH WILL ARRIVE FRIDAY INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 105 PM EDT WEDNESDAY... EXPANDED FLOOD WATCH NORTH ALONG THE BLUE RIDGE AND WEST BACK TO SOUTHEAST WEST VIRGINIA TO MATCH UP WITH LOWER FFG. CONVECTION DEVELOP THIS AFTERNOON ALONG THE BACKDOOR FRONTAL BOUNDARY AND CONVERGENCE ZONE BACK TO COLD FRONT. MORE CHANGES THIS AFTERNOON... AS OF 1017 AM EDT WEDNESDAY... BACKDOOR FRONT HAS PUSHED SOUTH INTO NORTHEAST PORTIONS OF FORECAST AREA THIS MORNING...WHILE COLD FRONT APPROACHES FROM THE WEST. SATELLITE IMAGES SHOWED AREA OF LOW CLOUDS AND FOG ACROSS NORTHEAST CORNER. QUESTIONS REMAIN ON HOW FAST THE LOW CLOUDS MIX OR SCATTERED OUT THIS MORNING. ADJUST CLOUD COVER FOR THIS MORNING INTO THIS AFTERNOON. HRRR THIS MORNING GENERATES CONVECTION ALONG THE CONVERGENCE ZONE STARTING AFTER 16Z MAINLY NORTH OF HIGHWAY 460. THIS MORNINGS RNK SOUNDING INDICATED THAT PWATS HAD CLIMB TO AROUND ONE INCH AND CAPES UP TO 1500 TO 2000 J/KG ARE POSSIBLE THIS AFTERNOON. EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP THIS AFTERNOON WITH DIFFERENTIAL HEATING...LIFT AND ADD MOISTURE. ISOLATED STORMS WITH STRONG UPDRAFTS ARE POSSIBLE THIS AFTERNOON WITH THE POTENTIAL FOR DAMAGING WINDS AND HAIL. THE SWODY1 OUTLOOK HAS PLACED THE SLIGHT RISK TO OUR NORTH AND WEST FOR THIS AFTERNOON. MODIFIED TEMPERATURES AND DEW POINTS ACCORDING TO LATEST TRENDS AND HELD ON TO FORECAST HIGHS FOR THIS AFTERNOON. WILL MAKE MORE CHANGES LATER THIS AFTERNOON. AS OF 650 AM EDT WEDNESDAY... ADJUSTMENTS THIS MORNING WERE MADE TO SKY COVER...NAMELY THE NE CWA WHERE LOW CIGS AND FOG WERE ADVECTING TOWARD LYH. THINK ONCE SUN COMES UP THIS WILL HALT THE PROGRESSION TO ABOUT LYH THEN SHOULD SEE LOW CLOUDS SCATTER OUT. OTHERWISE STILL MAINLY SEEING ISOLATED SHOWERS WEST OF OUR CWA OVER ERN KY AND CENTRAL WV. PREVIOUS DISCUSSION FROM 400 AM TODAY... FORECAST CHALLENGE WILL BE COVERAGE OF SHOWERS AND STORMS TODAY BEFORE MAIN THRUST OF MOISTURE AND LIFT ARRIVE AFTER MIDNIGHT TONIGHT FROM THE SOUTHWEST. LATEST MODELS SHOWING A WEAK VORT LOBE MOVING FROM SOUTHWEST TO NORTHEAST TODAY ACROSS THE AREA...MAINLY IN THE 12Z-18Z TIME FRAME. THIS WILL HAVE SOME INFLUENCE ON PRECIP THREAT...BUT AGAIN THE OVERALL COVERAGE APPEARS TO LESSEN PER LATEST RUNS. THE MODELS ALL AGREE THAT THE NW CWA HAS THE BEST THREAT WITH LESS OF THE CHANCE OVER THE SOUTHEAST CWA. WILL FOLLOW THIS THINKING AND KEEP IN THE HIGH CHANCE IN THE GREENBRIER TO BATH/SOUTHERN SHENANDOAH VALLEY...SOUTH TOWARD ROANOKE/LYNCHBURG WITH SMALL CHANCE TO ISOLATED SOUTH OF HIGHWAY 460. EXPECTING ANOTHER WARM DAY BUT THE UPPER RIDGE SHIFTS EAST. THE RECORDS TODAY MAY NOT BE AS ATTAINABLE EXCEPT PERHAPS BLACKSBURG DEPENDING ON CLOUD COVER FROM THE CONVECTION UPSTREAM. SEE CLIMATE SECTION BELOW FOR RECORDS AT ALL OUR CLIMATE SITES. RUNNING WITH HIGHS FROM UPPER 70S-LOWER 80S NC MTNS-PORTIONS OF FAR SW VA/SE WV...TO MID 80S NEW RIVER VALLEY-ROANOKE-LYNCHBURG...AND AROUND 90 SOUTHSIDE VA INTO THE NC PIEDMONT. THERE WILL BE SOME SUBSIDENCE IN THE AFTERNOON BEHIND WEAK VORT...SO EXPECT A LULL IN THE SHOWERS AFTER 4 PM INTO THIS EVENING...BEFORE NEXT STRONG WAVE WORKS IN AHEAD OF THE FRONT OVERNIGHT. MODELS FAVOR THE SOUTHERN BLUE RIDGE GETTING THE SHOWERS AND ISOLATED STORMS AFTER MIDNIGHT AND WORKING NORTHEAST TO THE BLUE RIDGE OF VA/SE WV BY MORNING...MAYBE AS FAR EAST AS A LYH-DAN LINE. GIVEN THE HIGH PWATS RUNNING ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL THREAT OF FLASH FLOODING FROM HEAVY DOWNPOURS MAY START AS EARLY AS PREDAWN IN THE SOUTHWEST CWA. THEREFORE A FLASH FLOOD WATCH HAS BEEN ISSUED FOR THE SOUTHERN BLUE RIDGE AS FAR NORTH AS ROANOKE. THIS WILL RUN INTO LATE THURSDAY NIGHT. LOWS TONIGHT STAY MUGGY WITH UPPER 50S TO LOWER 60S MOUNTAINS...TO MID 60S ACROSS THE SOUTHSIDE OF VA INTO THE NC PIEDMONT...FOOTHILLS. && .SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... AS OF 345 AM EDT WEDNESDAY... IMPRESSIVE RAIN PRODUCING SYSTEM IS STILL SLATED TO MOVE INTO AND THROUGH THE AREA THURSDAY AND THURSDAY NIGHT. THE DRIVING FEATURES BEHIND OUR RAIN WILL BE A HIGHLY AMPLIFIED LONG WAVE TROUGH AND ASSOCIATED SURFACE COLD FRONT MAKING GRADUAL PROGRESS EASTWARD OF THE MISSISSIPPI RIVER VALLEY WITH VERY ABUNDANT MOISTURE AT THE SURFACE...LOW AND MID LEVELS OF THE ATMOSPHERE. WHILE THERE COULD BE SOME ISOLATED STRONG STORMS AHEAD OF THE MAIN FRONT...THE EXCESSIVE MOISTURE WILL QUICKLY ALLOW THE COLUMN TO SATURATE AND GREATLY REDUCE THE POTENTIAL FOR DRY AIR ALOFT TO CONTRIBUTE TO INCREASING THE CAPE VALUES. IN ADVANCE OF THE FRONT...LOW LEVEL FLOW WILL BE LONGITUDINAL AND PARALLEL TO THE MAIN UPPER TROUGH...AND THUS ALLOW FOR A SLOW PROGRESSION EASTWARD...ALLOWING PLENTY OF TIME FOR TRAINING CONVECTION TO PRODUCE HEAVY RAINFALL. THE IMPACT OF UPSLOPE ALONG THE BLUE RIDGE WILL ADD TO THIS FACTOR...AND IN THE SHORT TERM...THIS IS THE AREA OF GREATEST CONCERN. WOULD NOT BE SURPRISED AT THE END OF THE EVENT IF RAINFALL REPORTS FROM ALONG THE BLUE RIDGE TOP FOUR INCHES. GIVEN THIS AND IN COLLABORATION WITH THE GSP OFFICE...WE ARE POSTING A FLASH FLOOD WATCH FOR AREAS NEAR THE BLUE RIDGE SOUTH OF THE ROANOKE RIVER FROM MIDNIGHT TONIGHT THROUGH 600 AM FRIDAY. THIS SHOULD BE A GOOD START WHAT MAY BE ADDITIONAL WATCHES BASED UPON LATER COORDINATION WITH NEIGHBORING OFFICES AND THE LATEST GUIDANCE AS IT BECOMES AVAILABLE TODAY. FRIDAY INTO SATURDAY NIGHT...WHILE THE FRONT WILL BE TO OUR EAST...THE PARENT UPPER LOW/TROUGH WILL PROGRESS INTO AND OVER THE AREA. THIS WILL BRING AN ELEVATED COOL POOL OVER THE AREA...AND WE MAY SEE SOME ISOLATED SHOWERS ACROSS THE WESTERN PARTS OF THE AREA. ALSO...NOTABLY COOLER AIR WILL ARRIVE ACROSS THE REGION. OVERNIGHT LOWS IN THE LOWER 40S WILL BE COMMON ACROSS THE MOUNTAINS WITH MID TO UPPER 40S ACROSS THE PIEDMONT. && .LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 325 PM EDT TUESDAY... LONG WAVE TROF WILL GRADUALLY FILL AND LIFT NORTHEAST DURING THE MEDIUM RANGE AS SERIES OF SHORTWAVES ROTATE EAST THROUGH THE UPPER FLOW. THE 12Z ECMWF WAS LESS ROBUST COMPARED TO THE 00Z RUN WITH SHORTWAVE AND ASSOCIATED PRECIPITATION WITH THIS WAVE SUNDAY INTO MONDAY. IN ANY CASE...COLD AIR ALOFT IN PROXIMITY TO UPPER TROF COUPLED WITH DAYTIME SOLAR HEATING SHOULD BE SUFFICIENT TO SUPPORT DEVELOPMENT OF DIURNALLY DRIVEN SHOWERS..ESPECIALLY ACROSS THE WESTERN UPSLOPE LOCATIONS OF THE APPALACHIANS. WILL KEEP A DAILY THREAT FOR WIDELY SCATTERED TO SCATTERED SHOWERS THROUGH MUCH OF THE LONG TERM PERIOD...ALTHOUGH OVERALL TOTAL PRECIPITATION AMOUNTS SHOULD REMAIN LOCALIZED...AND LIMITED IN DURATION IN ANY PARTICULAR LOCATION. DEEPER SUBSIDENCE BUILDS IN EARLY NEXT WEEK AS THE UPPER LOW SHIFTS EAST. THE INFLUENCE OF THE SLOWLY DEPARTING UPPER TROUGH SHOULD HOLD TEMPERATURES NEAR NORMAL FOR MOST OF THE PERIOD...WITH HIGHS GENERALLY FROM THE MID 60S TO THE MID 70S. && .AVIATION /17Z WEDNESDAY THROUGH SUNDAY/... AS OF 730 AM EDT WEDNESDAY... ANY FOG THIS MORNING IS GOING TO BE GONE BY 13-14Z. SOME STRATUS ADVANCING TOWARD LYH MAY IMPACT THEM AT TIMES BETWEEN 12-13Z...BUT SUNSHINE WILL SCATTER THIS DECK OUT. SHOULD BE VFR THROUGH MOST OF THE PERIOD. CU SHOULD DEVELOP BY MIDDAY WITH BEST COVERAGE IN THE MTNS. SOME MID AND HIGH CLOUDS POSSIBLE AS WELL. LOOKS LIKE COVERAGE OF SHRA/TSRA WILL BE NORTH OF A LINE FROM BLF-BCB-ROA-LYH...SO HAVE VCTS IN AT TIMES THIS AFTERNOON. THE CONVECTION WEAKENS AND EXITS THIS EVENING...BEFORE THE NEXT STRONGER UPPER SHORTWAVE MOVES IN LATE FROM THE SOUTHWEST. PROBLEM SEEMS TO BE WHETHER WE GET FOG FORMATION OVERNIGHT BEFORE CLOUDS ROLL IN AND IMPEDE IT. ATTM...I AM HESISTANT TO ADD FOG BUT WOULD NOT BE SURPRISED TO SEE FOG FORM AT LWB/BCB LATE EVENING. CONFIDENCE IS LOW ON THIS. SHOWERS AND ISOLATED STORMS SHOULD MAKE IT INTO THE BLF/LWB/BCB AREAS BY THE END OF THIS TAF PERIOD...WITH MVFR VSBYS. EXPECT TO SEE BETTER THREAT FOR SHOWERS AND STORMS THURSDAY INTO THURSDAY NIGHT WITH SUB VFR LIKELY IN HEAVIER DOWNPOURS. COLD FRONT IS PROGGED TO CROSS THE MOUNTAINS THURSDAY AFTERNOON EXITING THE PIEDMONT AROUND MIDNIGHT THURSDAY NIGHT. UPPER LEVEL SYSTEM OVER THE GREAT LAKES FRIDAY WILL KEEP THE THREAT OF SHOWERS AROUND IN THE MOUNTAINS WITH UNDER VFR POSSIBLE AT BLF/LWB. SHOULD CLEAR OUT EAST OF THE MTNS AFTER FRIDAY BUT POTENTIAL FOR SHOWERS STAYS WITH US INTO THE WEEKEND AS WE STAY NEAR THE UPPER LEVEL SLOW MOVING LOW PRESSURE SYSTEM. && .HYDROLOGY... FLASH FLOOD WATCH IN EFFECT FOR THE SOUTHERN BLUE RIDGE AS FAR NORTH AS ROANOKE. MODELS AGREE THAT COPIOUS AMOUNTS OF MOISTURE WITH PWATS 2+ SD ABOVE NORMAL ALONG WITH A SLOW MOVING FRONT AND STRONG SE FLOW WILL PRODUCE TRAINING OF HEAVY RAIN. OVERALL POTENTIAL IS HIGH FOR FLASH FLOODING ALONG THE BLUE RIDGE. WILL AWAIT ANOTHER RUN OF MODELS PER COORDINATION WITH NEIGHBORING WFOS BEFORE EXPANDING THE WATCH. AS FAR AS MAIN STEM RIVERS...ENSEMBLES SUGGEST CHANCE OF MINOR FLOODING WITH POTENTIAL FOR MODERATE FLOODING ACROSS THE GREENBRIER AT ALDERSON. WILL SEE HOW THE RAIN PLAYS OUT FOR THIS. ATTM...WE ARE FORECASTING AN AVERAGE OF 1-3 INCHES OF RAIN...HIGHEST ALONG THE BLUE RIDGE WHERE UP TO 5 INCHES COULD OCCUR. && .CLIMATE... ANOTHER WARM DAY BUT RECORD HIGHS MAY BE SAFE...EXCEPT PERHAPS BLACKSBURG AS UPPER RIDGE SHIFTS EAST. SITE..........RECORDS/YEAR ROANOKE.......93/1956 LYNCHBURG.....92/1956 DANVILLE......95/1956 BLACKSBURG....86/2000 BLUEFIELD.....86/1985 LEWISBURG.....84/1985 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLASH FLOOD WATCH FROM MIDNIGHT EDT TONIGHT THROUGH LATE THURSDAY NIGHT FOR VAZ010>020-022>024-032>035. NC...FLASH FLOOD WATCH FROM MIDNIGHT EDT TONIGHT THROUGH LATE THURSDAY NIGHT FOR NCZ001>003-018-019. WV...FLASH FLOOD WATCH FROM MIDNIGHT EDT TONIGHT THROUGH LATE THURSDAY NIGHT FOR WVZ042>045. && $$ SYNOPSIS...WP NEAR TERM...KK/WP SHORT TERM...DS LONG TERM...KK AVIATION...WP HYDROLOGY...WP CLIMATE...WP