Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/30/14
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1050 PM MDT SUN APR 27 2014
.UPDATE...
ISSUED AT 1050 PM MDT SUN APR 27 2014
UPDATED TO INCREASE POPS ACROSS THE CENTRAL MTS THROUGH THE
OVERNIGHT.
UPDATE ISSUED AT 856 PM MDT SUN APR 27 2014
UPDATED FOR LATEST OBS...SATELLITE AND RADAR TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 327 PM MDT SUN APR 27 2014
CURRENTLY...STRONG UPPER LEVEL AND SURFACE LOW PRESSURE STACKED OVER
NORTHWESTERN KS WITH SOUTHERN END OF WRAP AROUND DEFORMATION PRECIP
SLOWLY WEAKENING OVER SOUTHEAST CO. FARTHER WEST...LAPS SURFACE
PRESSURE DATA SHOWS WEAK SECONDARY LOW PRESSURE NEAR KPUB...WHICH
HAS CREATED LIGHTER WINDS OVER MUCH OF PUEBLO COUNTY THIS
AFTERNOON...AND HAS IN GENERAL WEAKENED THE PRESSURE GRADIENT ACROSS
SOUTHEAST COLORADO. WITH CONVECTION ENDING AND STRONG SURFACE
GRADIENT LACKING...WIND SPEEDS HAVE BEGUN TO VERY SLOWLY DECREASE
ACROSS THE PLAINS...AND STRONGEST GUSTS HAVE FALLEN BACK INTO THE 40-
45 KT RANGE. LATEST HRRR SUGGESTS WIND SPEEDS HAVE ALREADY
PEAKED...AND GIVEN LACK OF OBSERVED 50 KT GUSTS...WILL CANCEL THE
HIGH WIND WARNING FOR THE FAR SOUTHEAST. OVER THE MOUNTAINS...STILL
SOME -SHSN OVER THE CONTINENTAL DIVIDE...THOUGH WEB CAMS SUGGEST
LITTLE IN THE WAY OF ACCUMULATION OR LOW VISIBILITY...AT LEAST AT
PASS LEVEL.
TONIGHT...WILL KEEP SOME LOW POPS IN THE EVENING TO ACCOUNT FOR
LINGERING -SHRA OVER THE SOUTHEAST PLAINS...WITH SOME HIGHER POPS
FOR THE CENTRAL MOUNTAINS ALONG THE CONTINENTAL DIVIDE...WHERE
SECONDARY UPPER WAVE WILL LIKELY HELP INCREASE -SHSN COVERAGE LATER
TONIGHT. EXPECT WINDS TO GRADUALLY DIMINISH ALL AREAS THROUGH THE
NIGHT...THOUGH MANY LOCATIONS WILL STAY BREEZY AS STRONG WINDS JUST
OFF THE SURFACE PERSIST. EXPECTING ENOUGH IN THE WAY OF WINDS/CLOUDS
TO KEEP PLAINS FROM A HARD FREEZE...THOUGH MOST MOUNTAINS AND HIGH
VALLEYS WILL DROP INTO THE 20S OR COLDER.
MONDAY...UPPER LOW VERY SLOWLY DRIFTS INTO ERN NEBRASKA DURING THE
DAY...KEEPING STRONG NW FLOW AT THE SURFACE AND ALOFT ACROSS MOST OF
SOUTHERN COLORADO. EXPECT WINDS TO INCREASE ALL AREAS BY MID
MORNING...WITH GUSTS IN THE 30-40 KT RANGE MOST LOCATIONS BY
AFTERNOON. GIVEN RATHER COLD AIR ALOFT/STEEP LAPSE RATES IN PLACE
MON AFTERNOON...SUSPECT AT LEAST ISOLATED RAIN AND SNOW SHOWERS WILL
DEVELOP OVER THE MOUNTAINS...WITH PERHAPS A FEW SPRINKLES/LIGHT
SHOWERS OVER LOWER ELEVATIONS LATE IN THE DAY. LOW LEVELS WILL BE
FAIRLY DRY...WHICH WILL KEEP PRECIP AMOUNTS LIGHT. MAX TEMPS WILL
REMAIN COOL...WITH BLENDED NUMERICAL GUIDANCE LOOKING OK FOR HIGHS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 327 PM MDT SUN APR 27 2014
VERY UNSETTLED PATTERN QUEUED UP FOR THE FORECAST AREA THROUGH THE
EXTENDED FORECAST...BUT MODELS ARE LEANING TOWARDS TWO SEPARATE
PERIODS OF WEATHER TYPES.
MONDAY NIGHT THROUGH THURSDAY...LONG RANGE MODELS INDICATE THAT THE
UPPER LOW PRESSURE SYSTEM WILL PINWHEEL ABOUT THE US CENTRAL PLAINS
AND UPPER MISSISSIPPI RIVER VALLEY THROUGH THU...BEFORE FINALLY
EJECTING TO THE NE ACROSS THE GREAT LAKES. THIS SOLUTION WILL KEEP
VERY BRISK AND COOL NORTHERLY FLOW IN PLACE FOR THE STATE INTO
THU...AS WELL AS A DAILY SHOT OF SHOWER ACTIVITY FOR THE CWA. AS THE
LOW LINGERS...LOBES OF ENERGY WILL ROTATE AROUND THE SYSTEM AND
BRING PERIODICALLY BETTER CHANCES FOR SHOWERS...THOUGH THE EXACT
TIMING OF THESE WINDOWS IS NEAR IMPOSSIBLE TO PREDICT AT THIS TIME.
LOOK FOR MAX TEMPS EACH DAY IN THE 50S TO AROUND 60 F FOR THE LOWER
ELEVATIONS...AND 30S TO 40S FOR THE MTS. THE HIGHER TERRAIN IS
EXPECTED TO EXPERIENCE ISOLATED TO LOW END SCATTERED POPS THROUGH
THU...WITH THE BEST SHOT OF SOME ISOLATED CONVECTION FOR THE PLAINS
COMING TUE AFTN...AND AGAIN WED AFTN AND EVE.
FRIDAY THROUGH SUNDAY...THE GFS AND EC MODELS HINT THAT BY FRI THE
UPPER LOW WILL FINALLY BE PULLING AWAY FROM THE REGION...ALLOWING
THE UPPER FLOW TO SHIFT TO A MORE WESTERLY DIRECTION INTO THE
WEEKEND. BOTH MODELS DO CONTINUE TO SHOW MEAGER SHOWER ACTIVITY BOTH
FRI AND SAT...MAINLY TIED TO THE HIGHER TERRAIN...BUT FEEL THAT THIS
FAR OUT THIS MAY BE A BIT OVERDONE. BY SUNDAY PCPN SHOULD COME TO AN
END. LOOK FOR A WARMING TREND INTO THE WEEKEND AS THE UPPER FLOW
SHIFTS...WITH MAX TEMPS IN THE 60S FOR FRI...THEN 70S FOR BOTH SAT
AND SUN. MOORE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1050 PM MDT SUN APR 27 2014
MODERATE TO STRONG NORTH TO NORTHWEST FLOW ALOFT WILL PERSIST
ACROSS THE STATE THROUGH THE MIDDLE OF THE WORK WEEK. THIS WILL
KEEP BREEZY TO WINDY CONDITIONS ACROSS THE AREA FROM THE LATE
MORNINGS THROUGH THE LATE EVENING HOURS. WITH THAT SAID...VFR
CONDITIONS EXPECTED AT ALS...COS AND PUB OVER THE NEXT 24 HOURS.
SHOULD SEE GUSTY NORTH TO NORTHWEST WIND OF 20-35KT DEVELOPING AT
TAF SITES AFT 16Z AND DIMINISH AFT 02Z. COULD SEE ISOLATED SHOWERS
ACROSS THE HIGHER TERRAIN AFT 18Z...THOUGH DOES NOT LOOK TO AFFECT
TAFS ATTM.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MW
SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...MW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1141 PM EDT TUE APR 29 2014
.SYNOPSIS...
HIGH PRESSURE MOVES EAST AS A WARM FRONT APPROACHES FROM THE
SOUTHWEST THROUGH WEDNESDAY NIGHT. THE WARM FRONT MOVES NORTH OF
THE REGION ON THURSDAY. A WEAK COLD FRONT FOLLOWS THURSDAY NIGHT
FOLLOWED BY WEAK HIGH PRESSURE FRIDAY INTO THE WEEKEND. ANOTHER
COLD FRONT IS POSSIBLE LATE IN THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
FCST UPDATED TO INCLUDE NEW CSTL FLOOD ADVY FOR WED NGT. NO OTHER
CHANGES MADE.
DEEP LAYERED RIDGE AXIS CONTINUES TO SLOWLY SLIDE EAST OVERNIGHT.
AS IT DOES SO WILL SEE INCREASING ISENTROPIC FLOW AND DIVERGENCE
ALOFT FROM W TO E. STILL SHOULD GENERALLY BE CLOSE ENOUGH TO RIDGE
TO HAVE ENOUGH SUBSIDENCE TO KEEP RAIN SPOTTY - SO HAVE CONTINUED
WITH PERIODIC RAIN WORDING FOR OVERNIGHT.
A PERSISTENT EASTERLY FLOW WILL CONTINUE THROUGH THE NIGHT. THIS
FLOW WILL KEEP CONDITIONS COOL. USED A BLEND OF MAV/MET GUIDANCE
WITH NAM AND HRRR 2-METER TEMPERATURES FOR OVERNIGHT LOWS...WITH
TEMPERATURES AROUND 40 ACROSS THE NORTHERN INTERIOR AND LOWER 40S
ELSEWHERE.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
A STRENGTHENING LOW LEVEL JET...ALONG WITH PERSISTENT EAST FLOW WILL
CONTINUE TO SATURATE THE COLUMN. A HIGHER AREA OF ISENTROPIC LIFT
WILL MOVE INTO THE REGION DURING THE SHORT TERM...RESULTING IN
A HIGHER COVERAGE OF RAIN.
THE POTENTIAL FOR MORE CONVECTIVE ACTIVITY IS EXPECTED WEDNESDAY
AFTERNOON DUE TO INCREASED LIFT...DEEPER MOISTURE AND CLOSER
PROXIMITY TO FRONT.
RAINFALL AMOUNTS BY WEDNESDAY EVENING WILL BE AT OR ABOVE AN INCH
ACROSS SOUTHWEST SECTIONS...TO UNDER AN INCH EAST.
METRO NJ/NYC SECTIONS COULD BE DEALING WITH URBAN FLOOD ISSUES LATE
IN THE DAY ON WEDNESDAY.
THE BEST FORCING MOVES OVER THE REGION WEDNESDAY NIGHT...BRINGING
THE BEST CHANCES FOR HEAVY RAIN AND POSSIBLY EVEN SOME THUNDER.
PRECIPITABLE WATERS INCREASE TO ABOUT 1.5 INCHES...SO WE COULD BE
LOOKING AT RAINFALL RATES AT OR NEAR ONE INCH PER HOUR. REFER TO
THE HYDROLOGY SECTION OF THE AFD FOR AMOUNTS AND IMPACTS.
AS FOR TEMPERATURES...WE SHOULD NOT SEE MUCH CHANGE IN TEMPERATURES
THROUGH THE SHORT TERM WITH EASTERLY FLOW...OVERCAST SKIES AND
RAINFALL. EXPECTED TEMPERATURES TO REMAIN IN THE 40S ON
WEDNESDAY...THEN COULD SEE TEMPERATURES RISE WEDNESDAY
NIGHT...DEPENDING ON EXACTLY WHEN THE WARM FRONT PUSHES N.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE UNSETTLED PATTERN WILL CONTINUE THROUGH THE LONG TERM PERIOD.
THE MODELS ARE IN PRETTY GOOD AGREEMENT CONCERNING THE PROGRESSION
OF THE CLOSED UPPER LOW OVER THE MIDWEST TO AN OPEN AND FLATTENING
WAVE THURSDAY AND FRIDAY. I/M NOT TOO COMFORTABLE WITH TOTALLY
BUYING INTO THIS AS THE MODELS TEND TO BE TOO QUICK WITH THIS
TRANSITION. EITHER WAY...WILL KEEP POPS IN THE FORECAST THROUGH
THURSDAY EVENING...AND WOULD NOT BE SURPRISED TO SEE PRECIPITATION
LINGER INTO FRIDAY FROM THIS SYSTEM. THEREAFTER...A BIT OF A TREND
TOWARD DRIER CONDITIONS AS FLOW FLATTENS OUT ALOFT. THERE WILL
STILL BE A WEAK MEAN TROUGH AXIS OVER THE MID WEST AND GREAT LAKES
WITH OCCASIONAL WEAK SHORT WAVES. WILL KEEP A MENTION OF
SHOWERS...MAINLY FOR AFTERNOON AND EARLY EVENING PERIODS FOR ANY
DIURNAL DRIVEN SHOWERS.
A STRONGER SHORTWAVE WILL SHARPEN THE TROUGH...AND POSSIBLY RESULT
IN ANOTHER CUTOFF OVER THE GREAT LAKES AND NORTHEAST BY SUNDAY.
THIS WILL PUSH A COLD FRONT ACROSS THE REGION LATE SUNDAY OR SUNDAY
NIGHT SPARKING OFF ANOTHER PERIOD OF SHOWERS AND POSSIBLY A
THUNDERSTORM. AGAIN THE MODELS ARE FAIRLY PROGRESSIVE WITH THIS
UPPER LEVEL LOW AND SHIFT THE POSITION OF THE LOW TO OUR NORTHEAST
BY MONDAY. THIS MAY TURN OUT TO BE QUICK AS WELL.
MODEL SOLUTIONS BEGIN TO DIVERGE FOR EARLY NEXT WEEK WITH THE ECMWF
REDEVELOPING A MEAN TROUGH / POTENTIAL CUTOFF WITH UPSTREAM ENERGY
WHILE THE GFS ADVERTISES ZONAL FLOW.
IF THE MODELS ARE CORRECT ABOUT THE PROGRESSION OF THE UPPER LOW
TRANSITIONING INTO AN OPEN WAVE...WE WILL HAVE A MILD START TO THE
LONG TERM PERIOD ON THURSDAY. THIS WILL BE THE WARMEST DAY OF THE
PERIOD...WITH A TREND TOWARD COOL AND GENERALLY DAMP CONDITIONS
THEREAFTER.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
AN AREA OF LOW PRESSURE WILL SLOWLY APPROACH AND MOVE ACROSS THE
REGION THROUGH THE MIDDLE OF THE WEEK.
MVFR CIGS AROUND 020 PERSISTING THIS EVENING. CIGS SLOWLY
LOWERING THRU TOMORROW MORNING TO IFR. P6SM VISIBILITY IN -RA
BECOMING MVFR TONIGHT...MOST LIKELY AT KTEB/KEWR FIRST. MORE
WIDESPREAD RAIN MOVES IN OVERNIGHT FROM WEST TO EAST...WITH VSBY
REDUCTION TO IFR.
WIND DIRECTION WILL LIKELY REMAIN 090-120 TRUE THRU TOMORROW
AFTERNOON/EVENING. GUSTS LIKELY TO CONTINUE THRU THE
NIGHT...BECOMING LESS FREQUENT BY MORNING. LLWS POSSIBLE OVERNIGHT
WED INTO THU ESPECIALLY FOR KTEB/KEWR/KSWF AND MAY NEED TO BE
ADDED TO TAFS IN FUTURE AMENDMENTS. ISOLATED EMBEDDED
THUNDERSTORMS POSSIBLE WEDNESDAY EVENING...BUT CONFIDENCE OF STORM
AT ANY GIVEN TERMINAL REMAINS TOO LOW TO ADD TO THE TAFS AT THIS
TIME.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: GUSTS MAY OCCASIONALLY BE 1-2 KT HIGHER THAN
FORECAST. P6SM VIS IN RAIN MAY PERSIST LONGER THAN FORECAST.
HEAVIER RAIN DEVELOPING AFTER 11-12Z.
KJFK FCSTER COMMENTS: GUSTS MAY OCCASIONALLY BE 1-2 KT HIGHER THAN
FORECAST. P6SM VIS IN RAIN MAY PERSIST LONGER THAN FORECAST.
HEAVIER RAIN DEVELOPING AFTER 12Z.
KLGA FCSTER COMMENTS: GUSTS MAY OCCASIONALLY BE 1-2 KT HIGHER THAN
FORECAST. P6SM VIS IN RAIN MAY PERSIST LONGER THAN FORECAST.
HEAVIER RAIN DEVELOPING AFTER 12-13Z.
KTEB FCSTER COMMENTS: GUSTS MAY OCCASIONALLY BE 1-2 KT HIGHER THAN
FORECAST. VIS MAY LINGER AROUND 5-6SM UNTIL HEAVIER RAIN MOVES IN
AFTER 11-12Z.
KHPN FCSTER COMMENTS: GUSTS MAY OCCASIONALLY BE 1-2 KT
HIGHER THAN FORECAST.
KISP FCSTER COMMENTS: GUSTS MAY OCCASIONALLY BE 1-2 KT HIGHER THAN
FORECAST.
.OUTLOOK FOR 21Z WEDNESDAY THROUGH SUNDAY...
.WED...MVFR OR LOWER WITH RA. E WINDS AROUND 20KT.
.WED NGT-THU...PERIODS OF IFR. TSTMS POSSIBLE. WINDS BECOMING SLY
AOA 20KT WITH LLWS POSSIBLE...BEFORE SWITCHING TO THE W.
.FRI...VFR WITH W WINDS.
.SAT...MAINLY VFR.
.SUN...-RA POSSIBLE WITH GUSTY W FLOW AROUND 15-20G30-35 DEVELOPING.
&&
.MARINE...
MADE MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK.
SMALL CRAFT ADVISORY REMAINS POSTED FOR ALL WATERS THROUGH WEDNESDAY
NIGHT. INCREASING EASTERLY WINDS...ALONG WITH BUILDING SEAS ARE
EXPECTED THROUGH WEDNESDAY NIGHT AS HIGH PRESSURE MOVES EAST AND A
WARM FRONT REMAINS NEAR OR SOUTH OF THE WATERS. WINDS WEDNESDAY
NIGHT WILL BECOME MORE SOUTHERLY...BUT GUSTY CONDITIONS AND ROUGH
SEAS WILL CONTINUE.
A ROBUST SOUTHWESTERLY FLOW ON THURSDAY WILL GRADUALLY SUBSIDE
FRIDAY INTO SATURDAY. SEAS WILL BE ROUGH ON THURSDAY...BUT WILL ALSO
FOLLOW THE SAME SLOW DOWNWARD TREND AS THE WINDS. A COLD FRONT WILL
APPROACH THE WATERS ON SUNDAY AND WILL RESULT IN STRENGTHENING WINDS
AND BUILDING SEAS SUNDAY NIGHT INTO MONDAY.
&&
.HYDROLOGY...
A SIGNIFICANT RAINFALL IS LIKELY WED THROUGH EARLY THU.
TOTAL BASIN AVG QPF SHOULD RANGE FROM 2.5 TO 3.5 INCHES...HIGHEST
NEAR NYC METRO AND NORTHEAST NJ. RAIN THROUGH WED AFTERNOON WILL
PRIME THE AREA FOR FLOODING PROBLEMS AS HEAVY RAIN MOVES IN FROM
LATE DAY WED INTO EARLY THU. NO CHANGES TO THE FLOOD WATCH WHICH
STARTS EARLIER FOR NYC METRO AND NE NJ WITH UP TO 1.5 INCHES OF RAIN
EXPECTED BY THAT TIME WHICH COULD IMPACT RUSH HOUR...THEN EXTENDED
TO THE REST OF THE AREA WED NIGHT INTO THU MORNING WITH ANOTHER PUSH
OF HEAVY RAIN. FLOODING OF SMALL STREAMS AND URBAN...LOW LYING AND
POOR DRAINAGE AREAS IS LIKELY.
&&
.TIDES/COASTAL FLOODING...
MINOR BENCH MARKS WERE REACHED AT ALL SOUTHERN GAUGES TNGT. LATEST
TRENDS INDICATE ON TRACK TO REACH MINOR BENCHMARKS ON WESTERN
SOUND EARLY OVERNIGHT.
TIDAL LEVELS WILL BE LOWER WITH THE WEDNESDAY MORNING INTO EARLY
AFTERNOON HIGH TIDES BUT WITH RESIDUAL SURGE...THERE COULD STILL BE
SOME ISOLATED MINOR COASTAL FLOODING POSSIBLE.
ANOTHER ROUND OF WIDESPREAD MINOR COASTAL FLOODING LIKELY WEDNESDAY
NIGHT. AS A RESULT HAVE ISSUED AN ADVY.
TIDAL LEVELS DROP FURTHER THURSDAY AND FLOW BECOMES MORE SOUTHWEST.
WHILE COASTAL FLOODING IS NOT EXPECTED AT THE MOMENT FOR THAT
TIME FRAME...THIS WILL STILL NEED TO BE WATCHED IN TRENDS FOR ANY
LOCATIONS THAT HAVE RESIDUAL WATER THAT CAN NOT DRAIN FULLY
OUT...ESPECIALLY ALONG THE CT COAST AND LONG ISLAND BACK BAYS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR CTZ005>008-010>012.
FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING
FOR CTZ009.
COASTAL FLOOD ADVISORY FROM 8 PM WEDNESDAY TO 2 AM EDT
THURSDAY FOR CTZ009-010.
COASTAL FLOOD ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR CTZ009-010.
NY...FLOOD WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR NYZ067-068-078>081.
FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING
FOR NYZ069>075-176>179.
COASTAL FLOOD ADVISORY FROM 8 PM WEDNESDAY TO 2 AM EDT
THURSDAY FOR NYZ071>075-078-080-176>179.
COASTAL FLOOD ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR NYZ071-073-
078-176-177.
COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NYZ080.
NJ...FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING
FOR NJZ002-004-006-103>108.
COASTAL FLOOD ADVISORY FROM 8 PM WEDNESDAY TO 2 AM EDT
THURSDAY FOR NJZ006-106-108.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ330-335-
338-340-345-350-353-355.
&&
$$
SYNOPSIS...BC
NEAR TERM...JMC/MALOIT
SHORT TERM...BC
LONG TERM...
AVIATION...MMD
MARINE...BC/MALOIT
HYDROLOGY...BC
TIDES/COASTAL FLOODING...JMC
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1109 PM EDT TUE APR 29 2014
.SYNOPSIS...
HIGH PRESSURE MOVES EAST AS A WARM FRONT APPROACHES FROM THE
SOUTHWEST THROUGH WEDNESDAY NIGHT. THE WARM FRONT MOVES NORTH OF
THE REGION ON THURSDAY. A WEAK COLD FRONT FOLLOWS THURSDAY NIGHT
FOLLOWED BY WEAK HIGH PRESSURE FRIDAY INTO THE WEEKEND. ANOTHER
COLD FRONT IS POSSIBLE LATE IN THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
DEEP LAYERED RIDGE AXIS CONTINUES TO SLOWLY SLIDE EAST OVERNIGHT.
AS IT DOES SO WILL SEE INCREASING ISENTROPIC FLOW AND DIVERGENCE
ALOFT FROM W TO E. STILL SHOULD GENERALLY BE CLOSE ENOUGH TO RIDGE
TO HAVE ENOUGH SUBSIDENCE TO KEEP RAIN SPOTTY - SO HAVE CONTINUED
WITH PERIODIC RAIN WORDING FOR OVERNIGHT.
A PERSISTENT EASTERLY FLOW WILL CONTINUE THROUGH THE NIGHT. THIS
FLOW WILL KEEP CONDITIONS COOL. USED A BLEND OF MAV/MET GUIDANCE
WITH NAM AND HRRR 2-METER TEMPERATURES FOR OVERNIGHT LOWS...WITH
TEMPERATURES AROUND 40 ACROSS THE NORTHERN INTERIOR AND LOWER 40S
ELSEWHERE.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
A STRENGTHENING LOW LEVEL JET...ALONG WITH PERSISTENT EAST FLOW WILL
CONTINUE TO SATURATE THE COLUMN. A HIGHER AREA OF ISENTROPIC LIFT
WILL MOVE INTO THE REGION DURING THE SHORT TERM...RESULTING IN
A HIGHER COVERAGE OF RAIN.
THE POTENTIAL FOR MORE CONVECTIVE ACTIVITY IS EXPECTED WEDNESDAY
AFTERNOON DUE TO INCREASED LIFT...DEEPER MOISTURE AND CLOSER
PROXIMITY TO FRONT.
RAINFALL AMOUNTS BY WEDNESDAY EVENING WILL BE AT OR ABOVE AN INCH
ACROSS SOUTHWEST SECTIONS...TO UNDER AN INCH EAST.
METRO NJ/NYC SECTIONS COULD BE DEALING WITH URBAN FLOOD ISSUES LATE
IN THE DAY ON WEDNESDAY.
THE BEST FORCING MOVES OVER THE REGION WEDNESDAY NIGHT...BRINGING
THE BEST CHANCES FOR HEAVY RAIN AND POSSIBLY EVEN SOME THUNDER.
PRECIPITABLE WATERS INCREASE TO ABOUT 1.5 INCHES...SO WE COULD BE
LOOKING AT RAINFALL RATES AT OR NEAR ONE INCH PER HOUR. REFER TO
THE HYDROLOGY SECTION OF THE AFD FOR AMOUNTS AND IMPACTS.
AS FOR TEMPERATURES...WE SHOULD NOT SEE MUCH CHANGE IN TEMPERATURES
THROUGH THE SHORT TERM WITH EASTERLY FLOW...OVERCAST SKIES AND
RAINFALL. EXPECTED TEMPERATURES TO REMAIN IN THE 40S ON
WEDNESDAY...THEN COULD SEE TEMPERATURES RISE WEDNESDAY
NIGHT...DEPENDING ON EXACTLY WHEN THE WARM FRONT PUSHES N.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE UNSETTLED PATTERN WILL CONTINUE THROUGH THE LONG TERM PERIOD.
THE MODELS ARE IN PRETTY GOOD AGREEMENT CONCERNING THE PROGRESSION
OF THE CLOSED UPPER LOW OVER THE MIDWEST TO AN OPEN AND FLATTENING
WAVE THURSDAY AND FRIDAY. I/M NOT TOO COMFORTABLE WITH TOTALLY
BUYING INTO THIS AS THE MODELS TEND TO BE TOO QUICK WITH THIS
TRANSITION. EITHER WAY...WILL KEEP POPS IN THE FORECAST THROUGH
THURSDAY EVENING...AND WOULD NOT BE SURPRISED TO SEE PRECIPITATION
LINGER INTO FRIDAY FROM THIS SYSTEM. THEREAFTER...A BIT OF A TREND
TOWARD DRIER CONDITIONS AS FLOW FLATTENS OUT ALOFT. THERE WILL
STILL BE A WEAK MEAN TROUGH AXIS OVER THE MID WEST AND GREAT LAKES
WITH OCCASIONAL WEAK SHORT WAVES. WILL KEEP A MENTION OF
SHOWERS...MAINLY FOR AFTERNOON AND EARLY EVENING PERIODS FOR ANY
DIURNAL DRIVEN SHOWERS.
A STRONGER SHORTWAVE WILL SHARPEN THE TROUGH...AND POSSIBLY RESULT
IN ANOTHER CUTOFF OVER THE GREAT LAKES AND NORTHEAST BY SUNDAY.
THIS WILL PUSH A COLD FRONT ACROSS THE REGION LATE SUNDAY OR SUNDAY
NIGHT SPARKING OFF ANOTHER PERIOD OF SHOWERS AND POSSIBLY A
THUNDERSTORM. AGAIN THE MODELS ARE FAIRLY PROGRESSIVE WITH THIS
UPPER LEVEL LOW AND SHIFT THE POSITION OF THE LOW TO OUR NORTHEAST
BY MONDAY. THIS MAY TURN OUT TO BE QUICK AS WELL.
MODEL SOLUTIONS BEGIN TO DIVERGE FOR EARLY NEXT WEEK WITH THE ECMWF
REDEVELOPING A MEAN TROUGH / POTENTIAL CUTOFF WITH UPSTREAM ENERGY
WHILE THE GFS ADVERTISES ZONAL FLOW.
IF THE MODELS ARE CORRECT ABOUT THE PROGRESSION OF THE UPPER LOW
TRANSITIONING INTO AN OPEN WAVE...WE WILL HAVE A MILD START TO THE
LONG TERM PERIOD ON THURSDAY. THIS WILL BE THE WARMEST DAY OF THE
PERIOD...WITH A TREND TOWARD COOL AND GENERALLY DAMP CONDITIONS
THEREAFTER.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
AN AREA OF LOW PRESSURE WILL SLOWLY APPROACH AND MOVE ACROSS THE
REGION THROUGH THE MIDDLE OF THE WEEK.
MVFR CIGS AROUND 020 PERSISTING THIS EVENING. CIGS SLOWLY
LOWERING THRU TOMORROW MORNING TO IFR. P6SM VISIBILITY IN -RA
BECOMING MVFR TONIGHT...MOST LIKELY AT KTEB/KEWR FIRST. MORE
WIDESPREAD RAIN MOVES IN OVERNIGHT FROM WEST TO EAST...WITH VSBY
REDUCTION TO IFR.
WIND DIRECTION WILL LIKELY REMAIN 090-120 TRUE THRU TOMORROW
AFTERNOON/EVENING. GUSTS LIKELY TO CONTINUE THRU THE
NIGHT...BECOMING LESS FREQUENT BY MORNING. LLWS POSSIBLE OVERNIGHT
WED INTO THU ESPECIALLY FOR KTEB/KEWR/KSWF AND MAY NEED TO BE
ADDED TO TAFS IN FUTURE AMENDMENTS. ISOLATED EMBEDDED
THUNDERSTORMS POSSIBLE WEDNESDAY EVENING...BUT CONFIDENCE OF STORM
AT ANY GIVEN TERMINAL REMAINS TOO LOW TO ADD TO THE TAFS AT THIS
TIME.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: GUSTS MAY OCCASIONALLY BE 1-2 KT HIGHER THAN
FORECAST. P6SM VIS IN RAIN MAY PERSIST LONGER THAN FORECAST.
HEAVIER RAIN DEVELOPING AFTER 11-12Z.
KJFK FCSTER COMMENTS: GUSTS MAY OCCASIONALLY BE 1-2 KT HIGHER THAN
FORECAST. P6SM VIS IN RAIN MAY PERSIST LONGER THAN FORECAST.
HEAVIER RAIN DEVELOPING AFTER 12Z.
KLGA FCSTER COMMENTS: GUSTS MAY OCCASIONALLY BE 1-2 KT HIGHER THAN
FORECAST. P6SM VIS IN RAIN MAY PERSIST LONGER THAN FORECAST.
HEAVIER RAIN DEVELOPING AFTER 12-13Z.
KTEB FCSTER COMMENTS: GUSTS MAY OCCASIONALLY BE 1-2 KT HIGHER THAN
FORECAST. VIS MAY LINGER AROUND 5-6SM UNTIL HEAVIER RAIN MOVES IN
AFTER 11-12Z.
KHPN FCSTER COMMENTS: GUSTS MAY OCCASIONALLY BE 1-2 KT
HIGHER THAN FORECAST.
KISP FCSTER COMMENTS: GUSTS MAY OCCASIONALLY BE 1-2 KT HIGHER THAN
FORECAST.
.OUTLOOK FOR 21Z WEDNESDAY THROUGH SUNDAY...
.WED...MVFR OR LOWER WITH RA. E WINDS AROUND 20KT.
.WED NGT-THU...PERIODS OF IFR. TSTMS POSSIBLE. WINDS BECOMING SLY
AOA 20KT WITH LLWS POSSIBLE...BEFORE SWITCHING TO THE W.
.FRI...VFR WITH W WINDS.
.SAT...MAINLY VFR.
.SUN...-RA POSSIBLE WITH GUSTY W FLOW AROUND 15-20G30-35 DEVELOPING.
&&
.MARINE...
MADE MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK.
SMALL CRAFT ADVISORY REMAINS POSTED FOR ALL WATERS THROUGH WEDNESDAY
NIGHT. INCREASING EASTERLY WINDS...ALONG WITH BUILDING SEAS ARE
EXPECTED THROUGH WEDNESDAY NIGHT AS HIGH PRESSURE MOVES EAST AND A
WARM FRONT REMAINS NEAR OR SOUTH OF THE WATERS. WINDS WEDNESDAY
NIGHT WILL BECOME MORE SOUTHERLY...BUT GUSTY CONDITIONS AND ROUGH
SEAS WILL CONTINUE.
A ROBUST SOUTHWESTERLY FLOW ON THURSDAY WILL GRADUALLY SUBSIDE
FRIDAY INTO SATURDAY. SEAS WILL BE ROUGH ON THURSDAY...BUT WILL ALSO
FOLLOW THE SAME SLOW DOWNWARD TREND AS THE WINDS. A COLD FRONT WILL
APPROACH THE WATERS ON SUNDAY AND WILL RESULT IN STRENGTHENING WINDS
AND BUILDING SEAS SUNDAY NIGHT INTO MONDAY.
&&
.HYDROLOGY...
A SIGNIFICANT RAINFALL IS LIKELY WED THROUGH EARLY THU.
TOTAL BASIN AVG QPF SHOULD RANGE FROM 2.5 TO 3.5 INCHES...HIGHEST
NEAR NYC METRO AND NORTHEAST NJ. RAIN THROUGH WED AFTERNOON WILL
PRIME THE AREA FOR FLOODING PROBLEMS AS HEAVY RAIN MOVES IN FROM
LATE DAY WED INTO EARLY THU. NO CHANGES TO THE FLOOD WATCH WHICH
STARTS EARLIER FOR NYC METRO AND NE NJ WITH UP TO 1.5 INCHES OF RAIN
EXPECTED BY THAT TIME WHICH COULD IMPACT RUSH HOUR...THEN EXTENDED
TO THE REST OF THE AREA WED NIGHT INTO THU MORNING WITH ANOTHER PUSH
OF HEAVY RAIN. FLOODING OF SMALL STREAMS AND URBAN...LOW LYING AND
POOR DRAINAGE AREAS IS LIKELY.
&&
.TIDES/COASTAL FLOODING...
THE COASTAL FLOOD ADVISORY REMAINS IN EFFECT FOR ALL WESTERN
COASTLINES WEST OF SUFFOLK COUNTY NY AND MIDDLESEX CT.
MINOR BENCH MARKS WERE REACHED AT ALL SOUTHERN GAUGES...BUT WITH
HIGH TIDE STILL TO OCCUR AT LINDENHURST...WILL NOT MAKE ANY
CHANGES TO CURRENT HEADLINES. LATEST TRENDS INDICATE ON TRACK TO
REACH MINOR BENCHMARKS ON WESTERN SOUND EARLY OVERNIGHT.
TIDAL LEVELS WILL BE LOWER WITH THE WEDNESDAY MORNING INTO EARLY
AFTERNOON HIGH TIDES BUT WITH RESIDUAL SURGE...THERE COULD STILL BE
SOME ISOLATED MINOR COASTAL FLOODING POSSIBLE.
ANOTHER ROUND OF WIDESPREAD MINOR COASTAL FLOODING WILL BE A GREATER
CHANCE FOR HIGH TIDES WEDNESDAY NIGHT.
TIDAL LEVELS DROP FURTHER THURSDAY AND FLOW BECOMES MORE SOUTHWEST.
WHILE COASTAL FLOODING IS NOT EXPECTED AT THE MOMENT FOR THAT
TIME FRAME...THIS WILL STILL NEED TO BE WATCHED IN TRENDS FOR ANY
LOCATIONS THAT HAVE RESIDUAL WATER THAT CAN NOT DRAIN FULLY
OUT...ESPECIALLY ALONG THE CT COAST AND LONG ISLAND BACK BAYS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR CTZ005>008-010>012.
FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING
FOR CTZ009.
COASTAL FLOOD ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR CTZ009-010.
NY...FLOOD WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR NYZ067-068-078>081.
FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING
FOR NYZ069>075-176>179.
COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NYZ072-
074-075-080-178-179.
COASTAL FLOOD ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR NYZ071-073-
078-176-177.
NJ...FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING
FOR NJZ002-004-006-103>108.
COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NJZ006-
106-108.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ330-335-
338-340-345-350-353-355.
&&
$$
SYNOPSIS...BC
NEAR TERM...MALOIT
SHORT TERM...BC
LONG TERM...
AVIATION...MMD
MARINE...BC/MALOIT
HYDROLOGY...BC
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1007 PM EDT TUE APR 29 2014
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE EARLY TONIGHT WHILE THE LEADING
EDGE OF LIGHT RAIN PUSHES IN. SPOTTY PRECIPITATION WILL CONTINUE
WEDNESDAY...THEN LOW PRESSURE WILL APPROACH WEDNESDAY NIGHT AND
THURSDAY WITH PERIODS OF HEAVY RAIN. A FEW THUNDERSTORMS ARE ALSO
POSSIBLE. SCATTERED SHOWERS WILL REMAIN POSSIBLE THROUGH THE
WEEKEND...FOLLOWED BY DRIER AND COOLER CONDITIONS EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
10 PM UPDATE...
SIGNIFICANT CHANGES MADE TO THE NEAR-TERM FORECAST. ISENTROPIC
FORCING AROUND H7 BENEATH INCREASING DIFFLUENCE ALOFT ALLOWING FOR
WIDESPREAD RAIN ACROSS THE REGION. AMOUNTS WILL BE LIGHT THOUGH
THE HEAVIEST WILL BE ACROSS THE CT-RIVER VALLEY. COULD SEE A WET
SNOWFLAKE OR SLEET ACROSS THE HIGHER ELEVATIONS WITH H925 TEMPS A
DEGREE OR TWO BELOW FREEZING PER SPC MESOANALYSIS. COMPLICATIONS
TO THE EAST AS MOISTURE RUNS UP AGAINST MUCH DRIER AIR /SEE THE 0Z
SOUNDING OUT OF CHATHAM...IMPRESSIVELY DRY BETWEEN H9-H5!/.
NONE OF THE NEAR-TERM FORECAST GUIDANCE DOING WELL IN HANDLING THE
SITUATION. NEITHER THE RAP NOR HRRR HAVE PRECIP PROGRESSING SO FAR
TO THE EAST. HAVE HAD TO IMPROVISE ACCORDINGLY. PUSHED POPS TO
HIGH CATEGORICAL WHILE INCREASING THE PRECIPITATION AND THAT WILL
CONTINUE THROUGH THE MORNING FOR MUCH OF THE CENTRAL AND WESTERN
PORTIONS OF THE FORECAST AREA /MAINLY WEST OF WORCESTER MA/.
FILLING IN SOMEWHAT TO THE SOUTH AND WEST. PLUME OF PWATS PUSHING
NORTH ADVECTED ACROSS THE REGION WITH THE H85-6 MOIST TRANSPORT.
PERHAPS THE RAIN WILL TAPER OFF BRIEFLY...BUT EXPECT A RETURN
PUNCH OF MOISTURE INTO WEDNESDAY. MUCH OF THE IMPROVISED OUTCOMES
MATCH UP QUITE WELL WITH THE 29.18Z GEFS MEANS.
BUSTED ON THE MAX TEMPS TODAY AND THUS LEANING WITH COLDER
OUTCOMES FOR TONIGHT. THAT EASTERLY ONSHORE FLOW OFF THE OCEAN
WATERS RANGING AROUND THE LOW-40S IS REALLY PUTTING A DENT IN THE
START OF SPRING. SHOULD BE A CHILLY DISMAL NIGHT WITH LOWS DOWN
AROUND THE MID-30S FOR MUCH OF THE REGION.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WEDNESDAY...
AS THE SLOWLY MOVING HIGH PRES RIDGE PUSHES OFFSHORE...EXPECT
WINDS TO SHIFT AROUND TO E-SE DURING THE DAY. NEXT SURGE OF LOW
LEVEL MOISTURE CONVERGENCE WORKS INTO CENTRAL AND WESTERN AREAS
DURING THE LATE MORNING AND AFTERNOON. ONSHORE WINDS WILL HELP
FEEL MORE LOW LEVEL MOISTURE INTO THIS LIFT AS WELL AS INCREASE
H925 SOUTHERLY JET. E-SE WINDS WILL PICK UP ESPECIALLY ALONG THE
COAST AS PRESSURE GRADIENT TIGHTENS UP. STILL UNDER THE COOLER
MARITIME INFLUENCE...SO INSTABILITY WILL STAY OFFSHORE FOR NOW.
EXPECT HIGHS TO RANGE FROM THE MID-UPPER 40S WELL INLAND TO THE
LOWER 50S ACROSS S COASTAL AREAS.
WEDNESDAY NIGHT...
A WARM FRONT WILL BEGIN TO APPROACH FROM THE SW. ANOTHER SHORT OF
ENERGY WILL DEVELOP ALONG THIS FRONT WITH A POSSIBLE TRIPLE POINT/
WAVE OF LOW PRES APPROACHING OVERNIGHT. ALSO NOTING INCREASING
INSTABILITY AS TT/S INCREASE TO AROUND 50...K INDICES INTO THE
LOWER 30S AND LIFTED INDICES LOWER TO ZERO TO -1. HAVE PUT IN
MENTION OF THUNDER MAINLY AROUND OR AFTER MIDNIGHT BEGINNING
ACROSS N CT/W MA THEN SHIFTING E.
NOTING ANOTHER SHOT OF GOOD QPF MOVING IN DURING THIS TIMEFRAME
AS S WINDS INCREASE. THIS WILL BRING MOISTURE RICH AIR TOWARD THE
REGION AS PWATS INCREASE TO AROUND 1.5 INCHES...WHICH IS +2 SD
ABOVE SEASONAL NORMALS. FORECASTED QPF ON ORDER OF 0.7 TO 1.5
INCHES DURING THIS TIMEFRAME...HIGHEST ACROSS N CT INTO SW MA AND
W RI. THIS...ALONG WITH ANY CONVECTION POSSIBLY PRODUCING LOCALLY
HIGHER AMOUNTS OF RAINFALL...COULD CAUSE RISING RIVERS. WITH THIS
IN MIND...HAVE PUT UP A FLOOD WATCH FOR THOSE AREAS WHERE BEST
SHOT FOR CONVECTION AND HEAVIER RAINFALL. LEFT OUT SE RI AND SE MA
FOR NOW...AS IT APPEARS BEST CHANCE FOR HEAVIER RAINFALL WILL HOLD
OFF UNTIL THURSDAY.
EXPECT LOW TEMPS TO OCCUR EARLY AS WINDS SHIFT AROUND TO S-SE
OVERNIGHT. READINGS WILL BOTTOM OUT IN THE 40S BY AROUND
MIDNIGHT...THEN SHOULD REMAIN STEADY OR SLOWLY RISE...ESPECIALLY
ACROSS SOUTHERN AREAS AFTER MIDNIGHT AS THE WARM FRONT APPROACHES.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
BIG PICTURE...
THURSDAY STARTS WITH DEEP VERTICALLY STACKED LOW PRESSURE OVER
THE GREAT LAKES AND UPPER RIDGE ALONG THE PACIFIC COAST. THIS IS A
SLOW PATTERN AT THE START OF THE LONG TERM. THE UPPER LOW EJECTS
NORTHEAST INTO CANADA FRIDAY WHILE THE PACIFIC RIDGE BREAKS
DOWN...AND THE UPPER PATTERN TRANSITIONS TO A MORE ZONAL FLOW OVER
THE WEEKEND. SHORTWAVE DROPS SOUTH FROM THE CANADIAN ARCTIC AND
INTO THE ZONAL FLOW BY SATURDAY NIGHT...THEN RACES EAST TO NEW
ENGLAND SUNDAY. GOOD AGREEMENT BETWEEN THE GFS AND ECMWF THROUGH
THAT TIME ALTHOUGH SOME UNCERTAINTY ON TIMING SIMPLY BECAUSE IT IS
DAY 5/DAY 6. ZONAL FLOW SHOULD KEEP TEMPS NEAR SEASONABLE LEVELS.
THURSDAY MAY BE A LITTLE MILDER BECAUSE IT PREDATES THE ZONAL
FLOW...AND MONDAY MAY BE A LITTLE COLDER BECAUSE WE WILL BE ON THE
TRAILING SIDE OF THE ARCTIC SHORTWAVE. A MODEL BLEND IS FAVORED.
THE DAILIES...
THURSDAY...
COLD FRONT MOVES ACROSS THE REGION DURING THE DAY WITH HINTS OF A
TRIPLE POINT ALONG THE FRONT MOVING ACROSS SOUTHERN NEW ENGLAND. A
40-50 KNOT SOUTHWEST LOW LEVEL JET MOVES ACROSS THE REGION
BRINGING MILD AIR AND LOTS OF MOISTURE. PRECIPITABLE WATER VALUES
FORECAST AROUND 1.5 INCHES...WHICH IS 2 SD ABOVE NORMAL. THIS
PLUME OF MOISTURE SHIFTS OFFSHORE TO THE EAST BY EVENING. UPPER
DIVERGENCE CROSSES STRONGLY OVER THE TOP OF THE FRONT...BRINGING
AN ENHANCED LOW LEVEL CONVERGENCE/UPPER DIVERGENCE COUPLET. IN
OTHER WORDS...A WET DAY WITH LOCALLY HEAVY DOWNPOURS A
POSSIBILITY. STABILITY PARAMETERS /TOTALS AND SLI/ ARE MARGINAL
BUT FAVORABLE FOR THUNDER. EXPECT POPS TO DIMINISH TOWARD EVENING
AS THE COLD FRONT MOVES EAST. TEMPS AND QPF ARE FROM A BLEND OF
MODEL DATA.
FRIDAY-SATURDAY...
DRIER AIR MOVES IN AT HIGHER LEVELS AND LOW LEVELS WILL HAVE SOME
DRYING. BUT CROSS SECTIONS SHOW LINGERING HIGH RH BETWEEN 700 MB
AND 850 MB. EXPECT AT LEAST PARTLY CLOUDY SKIES...AND THE FORECAST
MAY UNDERESTIMATE THIS SKY COVER. SUFFICIENT INSTABILITY TO
GENERATE A FEW SHOWERS ESPECIALLY IN WESTERN/CENTRAL MASS AND SRN
NH. SATURDAY STARTS OUT WITH LESS SKY COVER BUT WITH SIMILAR
MOISTURE 850-700 MB. SO EXPECT DAYTIME CU AND SCATTERED OR WIDELY
SCATTERED SHOWERS. MIXING EACH DAY WILL REACH TO AT LEAST 850 MB
AND POSSIBLY 800 MB. TEMPS 2-4C WOULD SUPPORT MAX TEMPS IN THE LOW
TO MID 60S EACH DAY. WINDS IN THE MIXED LAYER REACH 20 KNOTS
FRIDAY AND LESS ON SATURDAY...EXPECT GUSTS TO 20 KNOTS ON FRIDAY.
SUNDAY-MONDAY-TUESDAY...
PARTIALLY CLOSED OFF SHORTWAVE RACES ALONG THE CANADIAN BORDER
AND GREAT LAKES. THIS WILL SUPPORT A SURFACE LOW AND COLD FRONT
THAT SWINGS THROUGH ON SUNDAY. COMPACT 110-KNOT UPPER JET DRIVES
THE SHORTWAVE AND SUPPORTS UPPER DIVERGENCE OVER THE NORTHEAST
USA. GOOD COLD ADVECTION ALOFT WITH THE COLD CORE MOVING IN...THIS
WILL DESTABILIZE THE AIRMASS. EXPECT CLOUDS AND A CHANCE OF
SHOWERS FROM EARLY SUNDAY THROUGH THE DAY. THE FRONT MOVES THROUGH
ON SUNDAY...BUT THE INSTABILITY LINGERS THROUGH MONDAY. WILL KEEP
CHANCE POPS THROUGH THAT TIME. DRIER WEATHER ARRIVES FOR TUESDAY.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH WEDNESDAY NIGHT/...MODERATE CONFIDENCE WITH
TRENDS BUT LOWER CONFIDENCE CONCERNING SPECIFIC TIMING OF IMPACTS.
TONIGHT...MVFR CIGS MOST AREAS IN LOW LEVEL EAST FLOW. VSBYS
MAINLY VFR...BUT MAY SEE LOCAL MVFR AFTER MIDNIGHT ACROSS CT
VALLEY INTO CENTRAL MA/S NH AS -RA MOVES E. E WIND GUSTS UP TO 25
KT ALONG S COAST.
WEDNESDAY...MAINLY MVFR CIGS/VFR VSBYS TO START...THEN
DETERIORATING TO IFR DURING THE AFTERNOON FROM W-E AS HEAVIER
RAIN MOVES IN. PATCHY FOG DEVELOPING ACROSS S COASTAL AREAS. E
WIND GUSTS UP TO 25 KT ACROSS S COASTAL AREAS.
WEDNESDAY NIGHT...CONDITIONS LOWERING TO GENERAL IFR WITH POCKETS
OF LIFR IN LOCALLY HEAVY RAINFALL MAINLY ACROSS N CT/SW MA INTO W
RI AS NIGHT PROGRESSES. CHANCE FOR TSTMS ACROSS N CT/RI MAINLY
AFTER MIDNIGHT. SE WINDS GUSTING TO 25 KT MAINLY ALONG THE COAST.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.
OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
THURSDAY...IFR IN RAIN AND FOG. RAIN COULD BE HEAVY AT TIMES.
THERE IS ALSO SUFFICIENT INSTABILITY FOR A CHANCE OF THUNDER.
SOUTHWEST WINDS AT 2000 FEET WILL REACH 40-50 KNOTS AND MAY CREATE
A LOW LEVEL WIND SHEAR CONCERN.
FRIDAY AND SATURDAY...VFR WITH OCCASIONAL MVFR CIGS/VSBYS IN
SHOWERS FRIDAY. WEST WINDS GUSTING TO 20 KNOTS FRIDAY. MAINLY VFR
SATURDAY WITH LIGHTER SOUTHWEST WINDS.
SUNDAY...
VFR TO START WITH INCREASING CHANCE OF MVFR CIGS/VSBYS IN
SHOWERS.
&&
.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.
TONIGHT...E-NE WINDS WILL DIMINISH SOMEWHAT...BUT WILL STILL GUST
UP TO 20 KT. WILL SEE GUSTS UP TO 25-30 KT ON THE SOUTHERN OUTER
WATERS. E SWELLS UP TO 10 FT WILL CONTINUE ACROSS THE EASTERN
WATERS. SMALL CRAFTS CONTINUE FOR ALL OPEN WATERS. HAVE
DISCONTINUED SMALL CRAFT FOR BOSTON HARBOR AS WINDS/SEAS WILL
REMAIN BELOW CRITERIA.
WEDNESDAY-WEDNESDAY NIGHT...E WINDS GUSTING TO 25-30 KT OVER MOST
OPEN WATERS WILL SHIFT TO SE WED NIGHT. HIGHEST GUSTS OVER THE
OUTER WATERS WED NIGHT. SEAS REMAIN AOA 5 FT OVER THE OPEN WATERS.
HAVE PUT SMALL CRAFT UP FOR NARRAGANSETT BAY FOR LATE WED-WED
NIGHT.
OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
THURSDAY...SOUTH TO SOUTHWEST WINDS GUSTING 25-30 KNOTS. VSBYS
1-3 MILES IN LOCALLY HEAVY DOWNPOURS. SCATTERED TSTMS POSSIBLE.
WINDS WILL BUILD SEAS TO 5-9 FEET ON THE EXPOSED WATERS. COLD
FRONT CROSSES THE WATERS LATE IN THE DAY OR EVENING WITH WINDS
SHIFTING TO WEST OVERNIGHT. SMALL CRAFT ADVISORY CONTINUES
THROUGH EVENING.
FRIDAY-SATURDAY...WEST WINDS BELOW 25 KNOTS. SEAS 5-6 FEET ON THE
EXPOSED WATERS THROUGH SATURDAY MORNING. SMALL CRAFT ADVIS FOR
SEAS MAY BE NEEDED ON SOME OF THE WATERS FRIDAY AND FRIDAY NIGHT.
SUNDAY... WEST WINDS REMAIN BELOW 25 KNOTS. SEAS BUILD THROUGH
THE DAY AND MAY AGAIN REACH 5 FEET ON THE EXPOSED WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY AFTERNOON
FOR CTZ002>004.
MA...FLOOD WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY AFTERNOON
FOR MAZ009-011.
NH...NONE.
RI...FLOOD WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY AFTERNOON
FOR RIZ001>004-006.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ231>235-
237-250-251-254>256.
SMALL CRAFT ADVISORY FROM 6 PM WEDNESDAY TO 6 PM EDT THURSDAY
FOR ANZ236.
&&
$$
SYNOPSIS...WTB/EVT
NEAR TERM...SIPPRELL
SHORT TERM...EVT
LONG TERM...WTB/EVT
AVIATION...WTB/EVT
MARINE...WTB/EVT
AREA FORECAST DISCUSSION
NWS ALBANY NY
614 AM EDT MON APR 28 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME
SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX
STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES
TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND
UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 615 AM EDT...PATCHY CLOUDS ARE PERSISTING ACROSS PORTIONS OF
THE SOUTHERN GREENS...NORTHERN BERKSHIRES...AND NORTH/CENTRAL
TACONICS...ALBEIT WITH LESS AREAL COVERAGE NOTED OVER THE LAST 2
HOURS. WE EXPECT THESE PATCHY CLOUDS TO CONTINUE TO ERODE OVER THE
NEXT 1-3 HOURS...AS THEY MOVE SOUTH/SOUTHWEST.
OTHERWISE...WE EXPECT GENERALLY MOSTLY SUNNY SKIES TO START THE
DAY. HOWEVER...ADDITIONAL PATCHES OF CLOUDS ARE EXPECTED TO
APPROACH FROM THE NORTHEAST ONCE AGAIN LATER TODAY...AFFECTING
MAINLY SOUTHERN VT...NORTHERN MA...AND POSSIBLY THE UPPER HUDSON
RIVER VALLEY. IN ADDITION...HIGHER CLOUDS WILL BEGIN TO APPROACH
SOUTHERN AND WESTERN AREAS LATE THIS AFTERNOON.
THE CLOUDS ACROSS NORTHEAST AREAS WILL BE THE RESULT OF SOME
RESIDUAL MOISTURE ROTATING AROUND THE WESTERN PERIPHERY OF THE STORM
SYSTEM WELL OFF THE NEW ENGLAND COAST. SOME OF THE HI-RES
MODELS...INCLUDING THE HRRR AND THE OPERATIONAL NAM WRF HINT AT SOME
LIGHT SHOWERS OR SPRINKLES POSSIBLY AFFECTING SOME HIGHER ELEVATIONS
OF SOUTHERN VT BY EVENING. WILL INDICATE SOME SLIGHT CHC POPS FOR
ISOLATED SHOWERS/SPRINKLES IN THIS REGION TO ACCOUNT FOR THIS REMOTE
POSSIBILITY.
DEEP MIXING TODAY TO AROUND 825 MB SHOULD ALLOW TEMPS TO REACH 60-65
IN MOST VALLEY AREAS...AND 55-60 ACROSS HIGHER ELEVATIONS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
TONIGHT...A DEVELOPING EASTERLY LOW LEVEL FLOW WILL INITIALLY ENHANCE
LOW LEVEL MOISTURE AND LOW CLOUD POTENTIAL ACROSS THE REGION
LATER TONIGHT. THIS IS PARTICULARLY SUGGESTED BY THE RUC-13 AND
NAM...AS WELL AS THE REGIONAL GEM. IN ADDITION...HIGH CLOUDS WILL
CONTINUE TO INCREASE FROM THE SOUTH AND WEST. SO...WILL INDICATE
PARTLY TO MOSTLY CLOUDY SKIES OVERNIGHT...WITH CLOUDS BECOMING
MOST WIDESPREAD AFTER MIDNIGHT. WILL ALSO KEEP SLIGHT CHC POPS
ACROSS PORTIONS OF SOUTHERN VT/NORTHWEST MA FOR SOME ISOLATED
SHOWERS OR SPRINKLES...ESP THIS EVENING. WILL ALSO SIDE ON THE
MILDER SIDE OF GUIDANCE...WITH GENERALLY 40-45 EXPECTED IN
VALLEYS...AND 35-40 ACROSS HIGHER TERRAIN.
TUESDAY...THE MID LEVEL RIDGE AXIS WILL SLOWLY MOVE EAST OF THE
REGION DURING THE DAY...ALLOWING DEEPER MOISTURE TO BEGIN TO
OVERSPREAD THE REGION FROM SOUTHWEST TO NORTHEAST. HOWEVER...IT
APPEARS THAT FOR AREAS NEAR AND E OF THE HUDSON RIVER VALLEY...MOST
OF THE MORNING HOURS SHOULD REMAIN DRY. WILL LIMIT POPS IN THESE
AREAS FOR THE AFTERNOON HOURS...MAINLY IN THE CHC RANGE. TO THE
W...WILL INDICATE MAINLY CHC POPS IN THE MORNING...AND BOOST TO
LIKELY IN THE AFTERNOON. MOST OF THE RAIN SHOULD BE LIGHT...AS IT
WILL ENCOUNTER INITIALLY DRY LOW/MID LEVEL AIR AND MID LEVEL
SUBSIDENCE. TEMPS WILL BE SOMEWHAT TRICKY...AS ANY DELAY IN RAINFALL
WILL ALLOW FOR WARMER MAX TEMPS. WILL SIDE ON THE WARMER SIDE OF
GUIDANCE ACROSS THE UPPER HUDSON RIVER VALLEY AND SOUTHERN
VT...WHERE THE RAIN SHOULD DEVELOP LATEST...AND THE POSSIBILITY FOR
SOME THIN SPOTS ON THE OVERCAST WILL BE GREATEST. IN ADDITION...SOME
ENHANCED DOWNSLOPING WITH THE INCREASING E/SE LOW LEVEL FLOW MAY
HELP BOOST TEMPS FURTHER IN THESE AREAS...WHICH COULD REACH AROUND
60. ELSEWHERE...EXPECT MAX TEMPS TO REACH THE MID/UPPER 50S IN
VALLEYS FROM ALBANY N...W AND NORTHEAST...AND 50-55 TO THE SOUTH AND
WEST WHERE CLOUDS...RAIN...AND A COOLER MARINE MODIFIED AIR MASS
SHOULD KEEP TEMPS COOLER.
TUE NT-WED...ALTHOUGH IT APPEARS UNSETTLED DURING THIS PERIOD...IT
LOOKS LIKE IT WON/T BE A COMPLETE WASHOUT...AS POCKETS OF SYNOPTIC
LIFT MOVE ACROSS THE REGION. HOWEVER...THE GREATEST FORCING AND LOW
LEVEL MOISTURE CONVERGENCE WILL REMAIN MAINLY SOUTH AND WEST OF THE
REGION. SO...EXPECT SEVERAL ROUNDS OF SHOWERS AND/OR PERIODS OF
RAINFALL...BUT THERE COULD EASILY BE SOME PERIODS WHERE ONLY SOME
SPRINKLES OR PATCHY DRIZZLE OCCUR. AS A WEDGE OF DRIER AIR
ADVECTS WESTWARD AROUND THE SOUTHERN PERIPHERY OF THE VERY STRONG
HIGH TO OUR N...THERE IS ACTUALLY SOME POTENTIAL FOR SLEET TO MIX
IN WITH ANY SHOWERS ACROSS HIGHER ELEVATIONS OF THE SOUTHERN
ADIRONDACKS AND WESTERN NEW ENGLAND LATE TUE NT/EARLY WED AM.
TEMPS WILL COOL INTO THE MID 30S TO LOWER 40S TUE NT...AND SHOULD
ONLY REACH THE MID 40S TO LOWER 50S ON WED. IN FACT...SHOULD
RAINFALL BE MORE PERSISTENT/STEADIER ON WED...EVEN COOLER MAX
TEMPS COULD OCCUR...WITH MOST AREAS REMAINING BELOW 50. WINDS WILL
ALSO INCREASE DURING THIS PERIOD AS THE LOW LEVEL PRESSURE
GRADIENT TIGHTENS BETWEEN THE AFOREMENTIONED STRONG EASTERN
CANADIAN HIGH...AND LOW PRESSURE APPROACHING FROM THE SOUTH AND
WEST. EAST/SOUTHEAST WINDS WILL BECOME QUITE GUSTY AT TIMES...WITH
SOME GUSTS OF 30-40 MPH POSSIBLE AT TIMES BY WED
AFTN...PARTICULARLY ACROSS HIGHER ELEVATIONS OF THE
TACONICS...SOUTHERN GREEN MTNS...AND NORTHERN BERKSHIRES...AS WELL
AS ACROSS PORTIONS OF THE WESTERN ADIRONDACKS...MOHAWK VALLEY AND
CATSKILLS.
WED NT...THE BEST FORCING FROM THE COMBINATION OF ISENTROPIC
LIFT...MOISTURE TRANSPORT AND LOW LEVEL JET DYNAMICS APPEARS TO BE
DURING THIS PERIOD...LEADING TO WIDESPREAD SHOWERS OR A STEADY RAIN.
SOME OF THE RAIN COULD BE HEAVY AT TIMES. IT WILL ALSO INITIALLY
REMAIN WINDY...ESP THROUGH MIDNIGHT...WHERE SOME GUSTS INTO THE
35-45 MPH RANGE COULD OCCUR IN PORTIONS OF THE SOUTHERN GREENS AND
NORTHERN BERKSHIRES. IT APPEARS THAT A WIDESPREAD 1-2 INCHES OF
RAINFALL SHOULD OCCUR THROUGH DAYBREAK THU...WITH GREATER AMTS
POSSIBLE ACROSS PORTIONS OF THE SE CATSKILLS...MID HUDSON
VALLEY...AND NW CT. OVERNIGHT MINS SHOULD MAINLY BE IN THE UPPER 30S
TO MID 40S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
MORE UNSETTLED WEATHER IS EXPECTED TO LAST THROUGH THE UPCOMING
WEEKEND.
A VERTICALLY STACKED CUTOFF LOW WILL SIT AND SPIN OVER THE GREAT
LAKES REGION AS PIECES OF ENERGY ROTATE AROUND IT ACROSS THE
NORTHEAST. THIS WILL KEEP AT LEAST SCATTERED SHOWERS ACROSS OUR
REGION THURSDAY THROUGH SUNDAY. WHILE IT WILL NOT BE RAINING ALL OF
THE TIME THERE WILL BE PERIODS WHERE THE SHOWERS WILL BE MORE
NUMEROUS WHICH WILL BE ON THURSDAY INTO FRIDAY. RAINFALL AMOUNTS ON
THURSDAY THROUGH THURSDAY NIGHT WILL GENERALLY BE A THIRD OF AN INCH
TO THREE QUARTERS OF AN INCH. EXPECT HIGHS ON THURSDAY TO RANGE FROM
THE UPPER 50S AND LOWER 60S NORTHWEST TO LOWER 70S SOUTHEAST. LOWS
THURSDAY NIGHT WILL BE IN THE UPPER 30S TO UPPER 40S AND HIGHS ON
FRIDAY WILL BE IN THE MID 50S TO MID 60S.
THE UPPER LEVEL TROUGH WILL EXPAND EASTWARD TOWARDS THE NORTHEAST
FOR FRIDAY NIGHT INTO THE WEEKEND...AND START TO WEAKEN SOMEWHAT. AS A
RESULT...WE WILL STILL SEE THE OPPORTUNITY FOR SHOWERS EACH
DAY...MAINLY TIED TO DIURNAL HEATING AND TIMING OF WEAK VORTICITY
MAXES ROTATING AROUND THE UPPER LEVEL LOW. EXPECT LOWS FRIDAY NIGHT
TO RANGE FROM THE UPPER 30S NORTHWEST TO THE MID 40S SOUTHEAST WITH
HIGHS ON SATURDAY IN THE MID 50S TO MID 60S. LOWS ON SATURDAY NIGHT
ARE EXPECTED TO RANGE FROM THE MID 30S NORTHWEST TO THE MID 40S
SOUTHEAST. THERE IS THE POSSIBILITY OF A LITTLE SNOW ACROSS THE
SOUTHERN ADIRONDACKS LATE SATURDAY NIGHT. HIGHS ON SUNDAY WILL BE IN
THE MID 50S TO LOWER 60S.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS ARE EXPECTED AT ALL THE TAF SITES THROUGH THE END
OF THE TAF PERIOD ENDING AT 12Z TUESDAY.
DURING TODAY...N-NW WINDS WILL BE ABOUT 5-10 KTS WITH SCT DIURNAL
CU AT 4-6 KFT DEVELOPING DURING THE DAY. THERE WILL BE SOME
PASSING CIRRUS CLOUDS AS WELL...BUT NO PRECIPITATION IS EXPECTED
DUE TO HIGH PRESSURE NEARBY...AND VFR CONDITIONS WILL CONTINUE.
THE CIRRUS CLOUDS WILL BECOME THICKER BY EVENING.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA.
WEDNESDAY: HIGH OPERATIONAL IMPACT.WINDY WITH GUSTS TO 31.0 LIKELY SHRA.
WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. OCNL SHRA.
THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
RH VALUES WILL FALL INTO THE 25-30 PERCENT RANGE THIS AFTERNOON...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME
SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX
STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES
TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND
UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY...ALONG WITH A
WETTING RAINFALL.
THE RH WILL FALL INTO THE 25-35 PERCENT RANGE FOR MOST AREAS THIS
AFTERNOON...LOWEST IN VALLEY AREAS. THE RH WILL THEN RECOVER TO
80-95 PERCENT TONIGHT...THEN FALL INTO THE 30-40 PERCENT RANGE FOR
NORTHERN AREAS...AND 40-60 PERCENT RANGE FOR SOUTHERN AND WESTERN
AREAS TUESDAY AFTERNOON.
NORTHWEST WINDS AT 5-10 MPH THIS MORNING WILL BECOME NORTH TO
NORTHEAST AND INCREASE TO 5-15 MPH THIS AFTERNOON...WITH SOME GUSTS
POSSIBLY REACHING UP TO 20 MPH AT TIMES ACROSS PORTIONS OF THE UPPER
HUDSON RIVER VALLEY. WINDS WILL VEER INTO THE EAST TONIGHT AT 5-15
MPH...THEN BECOME E TO SE ON TUESDAY AND INCREASE TO 10-20
MPH...WITH SOME GUSTS OF 20-30 MPH POSSIBLE IN THE AFTERNOON...ESP
ACROSS PORTIONS OF SOUTHERN VT.
A WETTING RAINFALL IS EXPECTED FOR LATE TUESDAY THROUGH THURSDAY.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED THROUGH EARLY IN THE
WEEK.
EXPECTING DRY WEATHER THROUGH TONIGHT AS HIGH PRESSURE DOMINATES.
WET WEATHER WILL RETURN FOR MID WEEK AS A LARGE SLOW MOVING LOW
PRESSURE SYSTEM TO OUR WEST IMPACTS THE REGION. THIS SYSTEM HAS
THE POTENTIAL TO PRODUCE SOME HEAVY RAIN. HOWEVER THERE IS
UNCERTAINTY IN THE POTENTIAL QPF AMOUNTS. AT THIS TIME...IT
APPEARS THAT THE POTENTIAL FOR A WIDESPREAD 1-2 INCHES OF RAINFALL
IS INCREASING...WITH SOME LOCALLY HIGHER AMTS
POSSIBLE...PARTICULARLY ACROSS PORTIONS OF THE SE CATSKILLS...MID
HUDSON VALLEY...AND NW CT. THIS SHOULD CAUSE SIGNIFICANT WITHIN
BANK RISES ON MOST RIVERS...WITH THE POSSIBILITY OF SOME REACHING
ACTION STAGE...ESPECIALLY IN THE HOUSATONIC BASIN...AND POSSIBLY
ACROSS PORTIONS OF THE CATSKILLS.
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...KL/FRUGIS/IAA
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...FRUGIS/11
AVIATION...FRUGIS/11
FIRE WEATHER...KL/IAA
HYDROLOGY...KL/IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
605 AM EDT MON APR 28 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME
SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX
STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES
TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND
UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 445 AM EDT...PATCHY CLOUDS ACROSS PORTIONS OF THE WESTERN
ADIRONDACKS...AND THE UPPER HUDSON VALLEY REGION ARE FINALLY
BEGINNING TO ERODE. WE EXPECT THESE CLOUDS TO CONTINUE TO DECREASE
IN AREAL COVERAGE THROUGH SUNRISE...ALLOWING TEMPS TO FALL SEVERAL
MORE DEGREES IN MOST AREAS.
AFTER DAYBREAK...WE EXPECT MOSTLY SUNNY SKIES TO START THE DAY.
HOWEVER...ADDITIONAL PATCHES OF CLOUDS ARE EXPECTED TO APPROACH FROM
THE NORTHEAST LATER TODAY...AFFECTING MAINLY SOUTHERN VT...NORTHERN
MA...AND POSSIBLY THE UPPER HUDSON RIVER VALLEY. IN
ADDITION...HIGHER CLOUDS WILL BEGIN TO APPROACH SOUTHERN AND WESTERN
AREAS LATE THIS AFTERNOON.
THE CLOUDS ACROSS NORTHEAST AREAS WILL BE THE RESULT OF SOME
RESIDUAL MOISTURE ROTATING AROUND THE WESTERN PERIPHERY OF THE STORM
SYSTEM WELL OFF THE NEW ENGLAND COAST. SOME OF THE HI-RES
MODELS...INCLUDING THE HRRR AND THE OPERATIONAL NAM WRF HINT AT SOME
LIGHT SHOWERS OR SPRINKLES POSSIBLY AFFECTING SOME HIGHER ELEVATIONS
OF SOUTHERN VT BY EVENING. WILL INDICATE SOME SLIGHT CHC POPS FOR
ISOLATED SHOWERS/SPRINKLES IN THIS REGION TO ACCOUNT FOR THIS REMOTE
POSSIBILITY.
DEEP MIXING TODAY TO AROUND 825 MB SHOULD ALLOW TEMPS TO REACH 60-65
IN MOST VALLEY AREAS...AND 55-60 ACROSS HIGHER ELEVATIONS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
TONIGHT...A DEVELOPING EASTERLY LOW LEVEL FLOW WILL INITIALLY ENHANCE
LOW LEVEL MOISTURE AND LOW CLOUD POTENTIAL ACROSS THE REGION
LATER TONIGHT. THIS IS PARTICULARLY SUGGESTED BY THE RUC-13 AND
NAM...AS WELL AS THE REGIONAL GEM. IN ADDITION...HIGH CLOUDS WILL
CONTINUE TO INCREASE FROM THE SOUTH AND WEST. SO...WILL INDICATE
PARTLY TO MOSTLY CLOUDY SKIES OVERNIGHT...WITH CLOUDS BECOMING
MOST WIDESPREAD AFTER MIDNIGHT. WILL ALSO KEEP SLIGHT CHC POPS
ACROSS PORTIONS OF SOUTHERN VT/NORTHWEST MA FOR SOME ISOLATED
SHOWERS OR SPRINKLES...ESP THIS EVENING. WILL ALSO SIDE ON THE
MILDER SIDE OF GUIDANCE...WITH GENERALLY 40-45 EXPECTED IN
VALLEYS...AND 35-40 ACROSS HIGHER TERRAIN.
TUESDAY...THE MID LEVEL RIDGE AXIS WILL SLOWLY MOVE EAST OF THE
REGION DURING THE DAY...ALLOWING DEEPER MOISTURE TO BEGIN TO
OVERSPREAD THE REGION FROM SOUTHWEST TO NORTHEAST. HOWEVER...IT
APPEARS THAT FOR AREAS NEAR AND E OF THE HUDSON RIVER VALLEY...MOST
OF THE MORNING HOURS SHOULD REMAIN DRY. WILL LIMIT POPS IN THESE
AREAS FOR THE AFTERNOON HOURS...MAINLY IN THE CHC RANGE. TO THE
W...WILL INDICATE MAINLY CHC POPS IN THE MORNING...AND BOOST TO
LIKELY IN THE AFTERNOON. MOST OF THE RAIN SHOULD BE LIGHT...AS IT
WILL ENCOUNTER INITIALLY DRY LOW/MID LEVEL AIR AND MID LEVEL
SUBSIDENCE. TEMPS WILL BE SOMEWHAT TRICKY...AS ANY DELAY IN RAINFALL
WILL ALLOW FOR WARMER MAX TEMPS. WILL SIDE ON THE WARMER SIDE OF
GUIDANCE ACROSS THE UPPER HUDSON RIVER VALLEY AND SOUTHERN
VT...WHERE THE RAIN SHOULD DEVELOP LATEST...AND THE POSSIBILITY FOR
SOME THIN SPOTS ON THE OVERCAST WILL BE GREATEST. IN ADDITION...SOME
ENHANCED DOWNSLOPING WITH THE INCREASING E/SE LOW LEVEL FLOW MAY
HELP BOOST TEMPS FURTHER IN THESE AREAS...WHICH COULD REACH AROUND
60. ELSEWHERE...EXPECT MAX TEMPS TO REACH THE MID/UPPER 50S IN
VALLEYS FROM ALBANY N...W AND NORTHEAST...AND 50-55 TO THE SOUTH AND
WEST WHERE CLOUDS...RAIN...AND A COOLER MARINE MODIFIED AIR MASS
SHOULD KEEP TEMPS COOLER.
TUE NT-WED...ALTHOUGH IT APPEARS UNSETTLED DURING THIS PERIOD...IT
LOOKS LIKE IT WON/T BE A COMPLETE WASHOUT...AS POCKETS OF SYNOPTIC
LIFT MOVE ACROSS THE REGION. HOWEVER...THE GREATEST FORCING AND LOW
LEVEL MOISTURE CONVERGENCE WILL REMAIN MAINLY SOUTH AND WEST OF THE
REGION. SO...EXPECT SEVERAL ROUNDS OF SHOWERS AND/OR PERIODS OF
RAINFALL...BUT THERE COULD EASILY BE SOME PERIODS WHERE ONLY SOME
SPRINKLES OR PATCHY DRIZZLE OCCUR. AS A WEDGE OF DRIER AIR
ADVECTS WESTWARD AROUND THE SOUTHERN PERIPHERY OF THE VERY STRONG
HIGH TO OUR N...THERE IS ACTUALLY SOME POTENTIAL FOR SLEET TO MIX
IN WITH ANY SHOWERS ACROSS HIGHER ELEVATIONS OF THE SOUTHERN
ADIRONDACKS AND WESTERN NEW ENGLAND LATE TUE NT/EARLY WED AM.
TEMPS WILL COOL INTO THE MID 30S TO LOWER 40S TUE NT...AND SHOULD
ONLY REACH THE MID 40S TO LOWER 50S ON WED. IN FACT...SHOULD
RAINFALL BE MORE PERSISTENT/STEADIER ON WED...EVEN COOLER MAX
TEMPS COULD OCCUR...WITH MOST AREAS REMAINING BELOW 50. WINDS WILL
ALSO INCREASE DURING THIS PERIOD AS THE LOW LEVEL PRESSURE
GRADIENT TIGHTENS BETWEEN THE AFOREMENTIONED STRONG EASTERN
CANADIAN HIGH...AND LOW PRESSURE APPROACHING FROM THE SOUTH AND
WEST. EAST/SOUTHEAST WINDS WILL BECOME QUITE GUSTY AT TIMES...WITH
SOME GUSTS OF 30-40 MPH POSSIBLE AT TIMES BY WED
AFTN...PARTICULARLY ACROSS HIGHER ELEVATIONS OF THE
TACONICS...SOUTHERN GREEN MTNS...AND NORTHERN BERKSHIRES...AS WELL
AS ACROSS PORTIONS OF THE WESTERN ADIRONDACKS...MOHAWK VALLEY AND
CATSKILLS.
WED NT...THE BEST FORCING FROM THE COMBINATION OF ISENTROPIC
LIFT...MOISTURE TRANSPORT AND LOW LEVEL JET DYNAMICS APPEARS TO BE
DURING THIS PERIOD...LEADING TO WIDESPREAD SHOWERS OR A STEADY RAIN.
SOME OF THE RAIN COULD BE HEAVY AT TIMES. IT WILL ALSO INITIALLY
REMAIN WINDY...ESP THROUGH MIDNIGHT...WHERE SOME GUSTS INTO THE
35-45 MPH RANGE COULD OCCUR IN PORTIONS OF THE SOUTHERN GREENS AND
NORTHERN BERKSHIRES. IT APPEARS THAT A WIDESPREAD 1-2 INCHES OF
RAINFALL SHOULD OCCUR THROUGH DAYBREAK THU...WITH GREATER AMTS
POSSIBLE ACROSS PORTIONS OF THE SE CATSKILLS...MID HUDSON
VALLEY...AND NW CT. OVERNIGHT MINS SHOULD MAINLY BE IN THE UPPER 30S
TO MID 40S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
MORE UNSETTLED WEATHER IS EXPECTED TO LAST THROUGH THE UPCOMING
WEEKEND.
A VERTICALLY STACKED CUTOFF LOW WILL SIT AND SPIN OVER THE GREAT
LAKES REGION AS PIECES OF ENERGY ROTATE AROUND IT ACROSS THE
NORTHEAST. THIS WILL KEEP AT LEAST SCATTERED SHOWERS ACROSS OUR
REGION THURSDAY THROUGH SUNDAY. WHILE IT WILL NOT BE RAINING ALL OF
THE TIME THERE WILL BE PERIODS WHERE THE SHOWERS WILL BE MORE
NUMEROUS WHICH WILL BE ON THURSDAY INTO FRIDAY. RAINFALL AMOUNTS ON
THURSDAY THROUGH THURSDAY NIGHT WILL GENERALLY BE A THIRD OF AN INCH
TO THREE QUARTERS OF AN INCH. EXPECT HIGHS ON THURSDAY TO RANGE FROM
THE UPPER 50S AND LOWER 60S NORTHWEST TO LOWER 70S SOUTHEAST. LOWS
THURSDAY NIGHT WILL BE IN THE UPPER 30S TO UPPER 40S AND HIGHS ON
FRIDAY WILL BE IN THE MID 50S TO MID 60S.
THE UPPER LEVEL TROUGH WILL EXPAND EASTWARD TOWARDS THE NORTHEAST
FOR FRIDAY NIGHT INTO THE WEEKEND...AND START TO WEAKEN SOMEWHAT. AS A
RESULT...WE WILL STILL SEE THE OPPORTUNITY FOR SHOWERS EACH
DAY...MAINLY TIED TO DIURNAL HEATING AND TIMING OF WEAK VORTICITY
MAXES ROTATING AROUND THE UPPER LEVEL LOW. EXPECT LOWS FRIDAY NIGHT
TO RANGE FROM THE UPPER 30S NORTHWEST TO THE MID 40S SOUTHEAST WITH
HIGHS ON SATURDAY IN THE MID 50S TO MID 60S. LOWS ON SATURDAY NIGHT
ARE EXPECTED TO RANGE FROM THE MID 30S NORTHWEST TO THE MID 40S
SOUTHEAST. THERE IS THE POSSIBILITY OF A LITTLE SNOW ACROSS THE
SOUTHERN ADIRONDACKS LATE SATURDAY NIGHT. HIGHS ON SUNDAY WILL BE IN
THE MID 50S TO LOWER 60S.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS ARE EXPECTED AT ALL THE TAF SITES THROUGH THE END
OF THE TAF PERIOD ENDING AT 12Z TUESDAY.
DURING TODAY...N-NW WINDS WILL BE ABOUT 5-10 KTS WITH SCT DIURNAL
CU AT 4-6 KFT DEVELOPING DURING THE DAY. THERE WILL BE SOME
PASSING CIRRUS CLOUDS AS WELL...BUT NO PRECIPITATION IS EXPECTED
DUE TO HIGH PRESSURE NEARBY...AND VFR CONDITIONS WILL CONTINUE.
THE CIRRUS CLOUDS WILL BECOME THICKER BY EVENING.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA.
WEDNESDAY: HIGH OPERATIONAL IMPACT.WINDY WITH GUSTS TO 31.0 LIKELY SHRA.
WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. OCNL SHRA.
THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
RH VALUES WILL FALL INTO THE 25-30 PERCENT RANGE THIS AFTERNOON...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME
SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX
STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES
TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND
UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY...ALONG WITH A
WETTING RAINFALL.
THE RH WILL FALL INTO THE 25-35 PERCENT RANGE FOR MOST AREAS THIS
AFTERNOON...LOWEST IN VALLEY AREAS. THE RH WILL THEN RECOVER TO
80-95 PERCENT TONIGHT...THEN FALL INTO THE 30-40 PERCENT RANGE FOR
NORTHERN AREAS...AND 40-60 PERCENT RANGE FOR SOUTHERN AND WESTERN
AREAS TUESDAY AFTERNOON.
NORTHWEST WINDS AT 5-10 MPH THIS MORNING WILL BECOME NORTH TO
NORTHEAST AND INCREASE TO 5-15 MPH THIS AFTERNOON...WITH SOME GUSTS
POSSIBLY REACHING UP TO 20 MPH AT TIMES ACROSS PORTIONS OF THE UPPER
HUDSON RIVER VALLEY. WINDS WILL VEER INTO THE EAST TONIGHT AT 5-15
MPH...THEN BECOME E TO SE ON TUESDAY AND INCREASE TO 10-20
MPH...WITH SOME GUSTS OF 20-30 MPH POSSIBLE IN THE AFTERNOON...ESP
ACROSS PORTIONS OF SOUTHERN VT.
A WETTING RAINFALL IS EXPECTED FOR LATE TUESDAY THROUGH THURSDAY.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED THROUGH EARLY IN THE
WEEK.
EXPECTING DRY WEATHER THROUGH TONIGHT AS HIGH PRESSURE DOMINATES.
WET WEATHER WILL RETURN FOR MID WEEK AS A LARGE SLOW MOVING LOW
PRESSURE SYSTEM TO OUR WEST IMPACTS THE REGION. THIS SYSTEM HAS
THE POTENTIAL TO PRODUCE SOME HEAVY RAIN. HOWEVER THERE IS
UNCERTAINTY IN THE POTENTIAL QPF AMOUNTS. AT THIS TIME...IT
APPEARS THAT THE POTENTIAL FOR A WIDESPREAD 1-2 INCHES OF RAINFALL
IS INCREASING...WITH SOME LOCALLY HIGHER AMTS
POSSIBLE...PARTICULARLY ACROSS PORTIONS OF THE SE CATSKILLS...MID
HUDSON VALLEY...AND NW CT. THIS SHOULD CAUSE SIGNIFICANT WITHIN
BANK RISES ON MOST RIVERS...WITH THE POSSIBILITY OF SOME REACHING
ACTION STAGE...ESPECIALLY IN THE HOUSATONIC BASIN...AND POSSIBLY
ACROSS PORTIONS OF THE CATSKILLS.
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...IAA/FRUGIS/KL
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...FRUGIS/11
AVIATION...FRUGIS/11
FIRE WEATHER...IAA/KL
HYDROLOGY...IAA/KL
AREA FORECAST DISCUSSION
NWS ALBANY NY
444 AM EDT MON APR 28 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME
SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX
STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES
TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND
UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 445 AM EDT...PATCHY CLOUDS ACROSS PORTIONS OF THE WESTERN
ADIRONDACKS...AND THE UPPER HUDSON VALLEY REGION ARE FINALLY
BEGINNING TO ERODE. WE EXPECT THESE CLOUDS TO CONTINUE TO DECREASE
IN AREAL COVERAGE THROUGH SUNRISE...ALLOWING TEMPS TO FALL SEVERAL
MORE DEGREES IN MOST AREAS.
AFTER DAYBREAK...WE EXPECT MOSTLY SUNNY SKIES TO START THE DAY.
HOWEVER...ADDITIONAL PATCHES OF CLOUDS ARE EXPECTED TO APPROACH FROM
THE NORTHEAST LATER TODAY...AFFECTING MAINLY SOUTHERN VT...NORTHERN
MA...AND POSSIBLY THE UPPER HUDSON RIVER VALLEY. IN
ADDITION...HIGHER CLOUDS WILL BEGIN TO APPROACH SOUTHERN AND WESTERN
AREAS LATE THIS AFTERNOON.
THE CLOUDS ACROSS NORTHEAST AREAS WILL BE THE RESULT OF SOME
RESIDUAL MOISTURE ROTATING AROUND THE WESTERN PERIPHERY OF THE STORM
SYSTEM WELL OFF THE NEW ENGLAND COAST. SOME OF THE HI-RES
MODELS...INCLUDING THE HRRR AND THE OPERATIONAL NAM WRF HINT AT SOME
LIGHT SHOWERS OR SPRINKLES POSSIBLY AFFECTING SOME HIGHER ELEVATIONS
OF SOUTHERN VT BY EVENING. WILL INDICATE SOME SLIGHT CHC POPS FOR
ISOLATED SHOWERS/SPRINKLES IN THIS REGION TO ACCOUNT FOR THIS REMOTE
POSSIBILITY.
DEEP MIXING TODAY TO AROUND 825 MB SHOULD ALLOW TEMPS TO REACH 60-65
IN MOST VALLEY AREAS...AND 55-60 ACROSS HIGHER ELEVATIONS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
TONIGHT...A DEVELOPING EASTERLY LOW LEVEL FLOW WILL INITIALLY ENHANCE
LOW LEVEL MOISTURE AND LOW CLOUD POTENTIAL ACROSS THE REGION
LATER TONIGHT. THIS IS PARTICULARLY SUGGESTED BY THE RUC-13 AND
NAM...AS WELL AS THE REGIONAL GEM. IN ADDITION...HIGH CLOUDS WILL
CONTINUE TO INCREASE FROM THE SOUTH AND WEST. SO...WILL INDICATE
PARTLY TO MOSTLY CLOUDY SKIES OVERNIGHT...WITH CLOUDS BECOMING
MOST WIDESPREAD AFTER MIDNIGHT. WILL ALSO KEEP SLIGHT CHC POPS
ACROSS PORTIONS OF SOUTHERN VT/NORTHWEST MA FOR SOME ISOLATED
SHOWERS OR SPRINKLES...ESP THIS EVENING. WILL ALSO SIDE ON THE
MILDER SIDE OF GUIDANCE...WITH GENERALLY 40-45 EXPECTED IN
VALLEYS...AND 35-40 ACROSS HIGHER TERRAIN.
TUESDAY...THE MID LEVEL RIDGE AXIS WILL SLOWLY MOVE EAST OF THE
REGION DURING THE DAY...ALLOWING DEEPER MOISTURE TO BEGIN TO
OVERSPREAD THE REGION FROM SOUTHWEST TO NORTHEAST. HOWEVER...IT
APPEARS THAT FOR AREAS NEAR AND E OF THE HUDSON RIVER VALLEY...MOST
OF THE MORNING HOURS SHOULD REMAIN DRY. WILL LIMIT POPS IN THESE
AREAS FOR THE AFTERNOON HOURS...MAINLY IN THE CHC RANGE. TO THE
W...WILL INDICATE MAINLY CHC POPS IN THE MORNING...AND BOOST TO
LIKELY IN THE AFTERNOON. MOST OF THE RAIN SHOULD BE LIGHT...AS IT
WILL ENCOUNTER INITIALLY DRY LOW/MID LEVEL AIR AND MID LEVEL
SUBSIDENCE. TEMPS WILL BE SOMEWHAT TRICKY...AS ANY DELAY IN RAINFALL
WILL ALLOW FOR WARMER MAX TEMPS. WILL SIDE ON THE WARMER SIDE OF
GUIDANCE ACROSS THE UPPER HUDSON RIVER VALLEY AND SOUTHERN
VT...WHERE THE RAIN SHOULD DEVELOP LATEST...AND THE POSSIBILITY FOR
SOME THIN SPOTS ON THE OVERCAST WILL BE GREATEST. IN ADDITION...SOME
ENHANCED DOWNSLOPING WITH THE INCREASING E/SE LOW LEVEL FLOW MAY
HELP BOOST TEMPS FURTHER IN THESE AREAS...WHICH COULD REACH AROUND
60. ELSEWHERE...EXPECT MAX TEMPS TO REACH THE MID/UPPER 50S IN
VALLEYS FROM ALBANY N...W AND NORTHEAST...AND 50-55 TO THE SOUTH AND
WEST WHERE CLOUDS...RAIN...AND A COOLER MARINE MODIFIED AIR MASS
SHOULD KEEP TEMPS COOLER.
TUE NT-WED...ALTHOUGH IT APPEARS UNSETTLED DURING THIS PERIOD...IT
LOOKS LIKE IT WON/T BE A COMPLETE WASHOUT...AS POCKETS OF SYNOPTIC
LIFT MOVE ACROSS THE REGION. HOWEVER...THE GREATEST FORCING AND LOW
LEVEL MOISTURE CONVERGENCE WILL REMAIN MAINLY SOUTH AND WEST OF THE
REGION. SO...EXPECT SEVERAL ROUNDS OF SHOWERS AND/OR PERIODS OF
RAINFALL...BUT THERE COULD EASILY BE SOME PERIODS WHERE ONLY SOME
SPRINKLES OR PATCHY DRIZZLE OCCUR. AS A WEDGE OF DRIER AIR
ADVECTS WESTWARD AROUND THE SOUTHERN PERIPHERY OF THE VERY STRONG
HIGH TO OUR N...THERE IS ACTUALLY SOME POTENTIAL FOR SLEET TO MIX
IN WITH ANY SHOWERS ACROSS HIGHER ELEVATIONS OF THE SOUTHERN
ADIRONDACKS AND WESTERN NEW ENGLAND LATE TUE NT/EARLY WED AM.
TEMPS WILL COOL INTO THE MID 30S TO LOWER 40S TUE NT...AND SHOULD
ONLY REACH THE MID 40S TO LOWER 50S ON WED. IN FACT...SHOULD
RAINFALL BE MORE PERSISTENT/STEADIER ON WED...EVEN COOLER MAX
TEMPS COULD OCCUR...WITH MOST AREAS REMAINING BELOW 50. WINDS WILL
ALSO INCREASE DURING THIS PERIOD AS THE LOW LEVEL PRESSURE
GRADIENT TIGHTENS BETWEEN THE AFOREMENTIONED STRONG EASTERN
CANADIAN HIGH...AND LOW PRESSURE APPROACHING FROM THE SOUTH AND
WEST. EAST/SOUTHEAST WINDS WILL BECOME QUITE GUSTY AT TIMES...WITH
SOME GUSTS OF 30-40 MPH POSSIBLE AT TIMES BY WED
AFTN...PARTICULARLY ACROSS HIGHER ELEVATIONS OF THE
TACONICS...SOUTHERN GREEN MTNS...AND NORTHERN BERKSHIRES...AS WELL
AS ACROSS PORTIONS OF THE WESTERN ADIRONDACKS...MOHAWK VALLEY AND
CATSKILLS.
WED NT...THE BEST FORCING FROM THE COMBINATION OF ISENTROPIC
LIFT...MOISTURE TRANSPORT AND LOW LEVEL JET DYNAMICS APPEARS TO BE
DURING THIS PERIOD...LEADING TO WIDESPREAD SHOWERS OR A STEADY RAIN.
SOME OF THE RAIN COULD BE HEAVY AT TIMES. IT WILL ALSO INITIALLY
REMAIN WINDY...ESP THROUGH MIDNIGHT...WHERE SOME GUSTS INTO THE
35-45 MPH RANGE COULD OCCUR IN PORTIONS OF THE SOUTHERN GREENS AND
NORTHERN BERKSHIRES. IT APPEARS THAT A WIDESPREAD 1-2 INCHES OF
RAINFALL SHOULD OCCUR THROUGH DAYBREAK THU...WITH GREATER AMTS
POSSIBLE ACROSS PORTIONS OF THE SE CATSKILLS...MID HUDSON
VALLEY...AND NW CT. OVERNIGHT MINS SHOULD MAINLY BE IN THE UPPER 30S
TO MID 40S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
MORE UNSETTLED WEATHER IS EXPECTED TO LAST THROUGH THE UPCOMING
WEEKEND.
A VERTICALLY STACKED CUTOFF LOW WILL SIT AND SPIN OVER THE GREAT
LAKES REGION AS PIECES OF ENERGY ROTATE AROUND IT ACROSS THE
NORTHEAST. THIS WILL KEEP AT LEAST SCATTERED SHOWERS ACROSS OUR
REGION THURSDAY THROUGH SUNDAY. WHILE IT WILL NOT BE RAINING ALL OF
THE TIME THERE WILL BE PERIODS WHERE THE SHOWERS WILL BE MORE
NUMEROUS WHICH WILL BE ON THURSDAY INTO FRIDAY. RAINFALL AMOUNTS ON
THURSDAY THROUGH THURSDAY NIGHT WILL GENERALLY BE A THIRD OF AN INCH
TO THREE QUARTERS OF AN INCH. EXPECT HIGHS ON THURSDAY TO RANGE FROM
THE UPPER 50S AND LOWER 60S NORTHWEST TO LOWER 70S SOUTHEAST. LOWS
THURSDAY NIGHT WILL BE IN THE UPPER 30S TO UPPER 40S AND HIGHS ON
FRIDAY WILL BE IN THE MID 50S TO MID 60S.
THE UPPER LEVEL TROUGH WILL EXPAND EASTWARD TOWARDS THE NORTHEAST
FOR FRIDAY NIGHT INTO THE WEEKEND...AND START TO WEAKEN SOMEWHAT. AS A
RESULT...WE WILL STILL SEE THE OPPORTUNITY FOR SHOWERS EACH
DAY...MAINLY TIED TO DIURNAL HEATING AND TIMING OF WEAK VORTICITY
MAXES ROTATING AROUND THE UPPER LEVEL LOW. EXPECT LOWS FRIDAY NIGHT
TO RANGE FROM THE UPPER 30S NORTHWEST TO THE MID 40S SOUTHEAST WITH
HIGHS ON SATURDAY IN THE MID 50S TO MID 60S. LOWS ON SATURDAY NIGHT
ARE EXPECTED TO RANGE FROM THE MID 30S NORTHWEST TO THE MID 40S
SOUTHEAST. THERE IS THE POSSIBILITY OF A LITTLE SNOW ACROSS THE
SOUTHERN ADIRONDACKS LATE SATURDAY NIGHT. HIGHS ON SUNDAY WILL BE IN
THE MID 50S TO LOWER 60S.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS ARE EXPECTED AT ALL THE TAF SITES THROUGH THE END
OF THE TAF PERIOD ENDING AT 06Z TUESDAY. DURING THE OVERNIGHT
HOURS EXPECT SCT-BKN STRATOCU CLOUDS OVER THE AREA. THESE CLOUDS
WILL DISSIPATE BY DAYBREAK AT MOST SITES ALTHOUGH IT MAY TAKE A
LITTLE LONGER AT KALB AS THE CLOUD AREAS IS SHRINKING FROM THE
EAST AND WEST...SO KALB WILL LIKELY BE THE LAST TO LOSE THE CLOUD
DECK WHICH WILL BE AT 4-6 KFT OVERNIGHT. N-NE WINDS WL AVG 4-6 KTS
OVERNIGHT.
DURING THE DAY ON MONDAY...N-NW WINDS WILL BE ABOUT 5-10 KTS WITH
SCT DIURNAL CU AT 4-6 KFT DEVELOPING DURING THE DAY. THERE WILL BE
SOME PASSING CIRRUS CLOUDS AS WELL...BUT NO PRECIPITATION IS
EXPECTED DUE TO HIGH PRESSURE NEARBY...AND VFR CONDITIONS WILL
CONTINUE. THE CIRRUS CLOUDS WILL BECOME THICKER BY EVENING.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA.
WEDNESDAY: HIGH OPERATIONAL IMPACT.WINDY WITH GUSTS TO 31.0 LIKELY SHRA.
WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. OCNL SHRA.
THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
...RH VALUES WILL FALL INTO THE 25-30 PERCENT RANGE THIS AFTERNOON...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME
SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX
STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES
TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND
UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY...ALONG WITH A
WETTING RAINFALL.
THE RH WILL FALL INTO THE 25-35 PERCENT RANGE FOR MOST AREAS THIS
AFTERNOON...LOWEST IN VALLEY AREAS. THE RH WILL THEN RECOVER TO
80-95 PERCENT TONIGHT...THEN FALL INTO THE 30-40 PERCENT RANGE FOR
NORTHERN AREAS...AND 40-60 PERCENT RANGE FOR SOUTHERN AND WESTERN
AREAS TUESDAY AFTERNOON.
NORTHWEST WINDS AT 5-10 MPH THIS MORNING WILL BECOME NORTH TO
NORTHEAST AND INCREASE TO 5-15 MPH THIS AFTERNOON...WITH SOME GUSTS
POSSIBLY REACHING UP TO 20 MPH AT TIMES ACROSS PORTIONS OF THE UPPER
HUDSON RIVER VALLEY. WINDS WILL VEER INTO THE EAST TONIGHT AT 5-15
MPH...THEN BECOME E TO SE ON TUESDAY AND INCREASE TO 10-20
MPH...WITH SOME GUSTS OF 20-30 MPH POSSIBLE IN THE AFTERNOON...ESP
ACROSS PORTIONS OF SOUTHERN VT.
A WETTING RAINFALL IS EXPECTED FOR LATE TUESDAY THROUGH THURSDAY.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED THROUGH EARLY IN THE
WEEK.
EXPECTING DRY WEATHER THROUGH TONIGHT AS HIGH PRESSURE DOMINATES.
WET WEATHER WILL RETURN FOR MID WEEK AS A LARGE SLOW MOVING LOW
PRESSURE SYSTEM TO OUR WEST IMPACTS THE REGION. THIS SYSTEM HAS
THE POTENTIAL TO PRODUCE SOME HEAVY RAIN. HOWEVER THERE IS
UNCERTAINTY IN THE POTENTIAL QPF AMOUNTS. AT THIS TIME...IT
APPEARS THAT THE POTENTIAL FOR A WIDESPREAD 1-2 INCHES OF RAINFALL
IS INCREASING...WITH SOME LOCALLY HIGHER AMTS
POSSIBLE...PARTICULARLY ACROSS PORTIONS OF THE SE CATSKILLS...MID
HUDSON VALLEY...AND NW CT. THIS SHOULD CAUSE SIGNIFICANT WITHIN
BANK RISES ON MOST RIVERS...WITH THE POSSIBILITY OF SOME REACHING
ACTION STAGE...ESPECIALLY IN THE HOUSATONIC BASIN...AND POSSIBLY
ACROSS PORTIONS OF THE CATSKILLS.
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...KL/IAA/FRUGIS
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...FRUGIS/11
AVIATION...FRUGIS/11
FIRE WEATHER...KL/IAA
HYDROLOGY...KL/IAA
AREA FORECAST DISCUSSION
NWS MIAMI FL
1003 AM EDT MON APR 28 2014
.UPDATE...
NO PLANS FOR CHANGES TO THE CURRENT FORECAST. THE 12Z SOUNDING FOR
MFL SHOWS VERY STEEP MID LEVEL LAPSE RATES COMING IN AT 7C/KM
WHICH IS ABOUT AS UNSTABLE AS IT GETS IN SOUTH FLORIDA. ALONG WITH
WARM SURFACE FORECAST TEMPERATURES OF THE MID 90S ACROSS THE
INTERIOR, THE ONLY MISSING INGREDIENT IS DEEP LAYER MOISTURE
CONTENT WHICH IS SERIOUSLY LACKING. BUT WITH THIS KIND OF
INSTABILITY, A FEW THUNDERSTORMS ARE DEFINITELY POSSIBLE ACROSS
THE INTERIOR AND HRRR DOES SHOW SOME ISOLATED DEVELOPMENT FOR
COLLIER NORTH TO GLADES COUNTIES. THE MARINE FORECAST IS ON TRACK
ALSO SO NO CHANGES PLANNED THEIR EITHER.
KOB
&&
.PREV DISCUSSION... /ISSUED 721 AM EDT MON APR 28 2014/
AVIATION...
LIGHT SOUTHEAST WINDS EARLY THIS MORNING WILL INCREASE TO 10-15
KNOTS WITH HIGHER GUSTS BY MID/LATE MORNING. GULF COAST SEA BREEZE
IS FORECAST AT KAPF THIS AFTERNOON...WITH A SOUTH TO SOUTHWEST
WIND. WINDS WILL DIMINISH THIS EVENING. LOW LEVEL MOISTURE WILL
INCREASE LATE IN THE TAF PERIOD FROM THE SOUTHEAST...BRINGING AN
INCREASE IN CLOUD COVER.
PREV DISCUSSION... /ISSUED 300 AM EDT MON APR 28 2014/
.A FEW THUNDERSTORMS POSSIBLE WESTERN INTERIOR THIS AFTERNOON...
SHORT TERM...
HIGH PRESSURE OVER THE WESTERN ATLANTIC WATERS WILL REMAIN NEARLY
STATIONARY TODAY INTO TUESDAY...AS LOW PRESSURE OVER THE CENTRAL
UNITED STATES MOVES SLOWLY TO THE NORTHEAST TOWARDS THE GREAT
LAKES. A MID TO UPPER LEVEL SHORTWAVE TROUGH OVER THE CENTRAL
GULF OF MEXICO WILL ALSO MOVE EAST AND THROUGH THE FLORIDA
PENINSULA THIS AFTERNOON BEFORE MOVING INTO THE WESTERN ATLANTIC
WATERS TONIGHT.
THIS WEATHER PATTERN WILL ALLOW FOR A SOUTHEAST WIND FLOW OVER
SOUTH FLORIDA TODAY INTO TUESDAY ALONG WITH THE EAST AND WEST
COAST SEA BREEZES DEVELOPING AND PUSHING INLAND EACH DAY. SO THERE
WILL BE A SLIGHT CHANCE OF SHOWERS OVER THE INTERIOR AREAS EACH
AFTERNOON WITH EVEN A SLIGHT CHANCE OF THUNDERSTORMS THIS AFTERNOON
WEST OF LAKE OKEECHOBEE.
THE LOW WILL CONTINUE TO MOVE SLOWLY NORTHEAST ACROSS THE GREAT
LAKES FOR THE MIDDLE TO END OF THE WEEK...AS THE HIGH MOVES SLOWLY
EAST FURTHER INTO THE ATLANTIC WATERS. THIS WILL ALLOW FOR A COLD
FRONT ASSOCIATED WITH THE LOW TO MOVE SOUTHEAST INTO THE
SOUTHEASTERN UNITED STATES FROM THE CENTRAL UNITED STATES. THIS IN
TURN WILL ALLOW FOR THE WIND FLOW OVER SOUTH FLORIDA TO BECOME
MORE SOUTHERLY...AND ALLOW FOR DEEPER TROPICAL MOISTURE TO WORK
INTO THE AREA FROM THE SOUTH. THEREFORE...THE POPS WILL REMAIN IN
THE ISOLATED TO SCATTERED RANGE OVER SOUTH FLORIDA WITH THE
HIGHEST POPS AROUND THE LAKE OKEECHOBEE REGION. THERE COULD ALSO
BE SOME THUNDERSTORMS FOR THE MIDDLE TO END OF THE WEEK OVER THE
INTERIOR AND LAKE OKEECHOBEE REGION.
LONG TERM...
THE COLD FRONT WILL CONTINUE TO MOVE SOUTHWARD THROUGH SOUTH
FLORIDA EARLY NEXT WEEKEND...BEFORE HIGH PRESSURE BUILDS INTO THE
AREA FROM THE NORTH FOR LATE NEXT WEEKEND. THIS WILL KEEP THE
TROPICAL MOISTURE IN PLACE OVER SOUTH FLORIDA EARLY NEXT
WEEKEND...BEFORE DRIER AIR WORKS INTO SOUTH FLORIDA FOR LATE NEXT
WEEKEND. SO WILL KEEP ISOLATED TO SCATTERED POPS OVER SOUTH
FLORIDA FOR THE FIRST HALF OF NEXT WEEKEND...BEFORE GOING DRY FOR
THE SECOND HALF OF NEXT WEEKEND.
MARINE...
THE WINDS WILL BE FROM THE SOUTHEAST AT 10 TO 15 KNOTS TODAY INTO
TUESDAY...BEFORE SWINGING TO A MORE SOUTHERLY DIRECTION FOR THE
MIDDLE TO END OF THE WEEK. THIS WILL KEEP THE SEAS AT BELOW 6 FEET
IN BOTH THE ATLANTIC AND GULF WATERS OF SOUTH FLORIDA THROUGH THE
WEEK.
THERE COULD ALSO BE A NORTHEAST SWELL OF 2 TO 3 FEET THAT WILL
BUILD INTO SOUTH FLORIDA ATLANTIC WATERS LATE THIS WEEK FROM THE
NORTH.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 77 88 77 / 10 10 10 10
FORT LAUDERDALE 87 79 87 79 / 10 10 10 10
MIAMI 88 78 88 78 / 10 10 10 10
NAPLES 89 74 89 74 / 10 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1044 PM EDT TUE APR 29 2014
.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM WILL APPROACH FROM THE WEST THROUGH
WEDNESDAY. THE FRONT WILL EXTEND THROUGH THE FORECAST AREA
WEDNESDAY NIGHT AND MOVE EAST OF THE AREA THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
DEEP MOISTURE LACKING ACROSS THE AREA EARLY THIS EVENING.
BASED ON LATEST GUIDANCE WILL LOWER POPS THROUGH MIDNIGHT...WITH
CHANCE MAINLY ALONG THE NORTH CAROLINA BORDER NEAR STATIONARY
FRONT. WITH COLD FRONT MOVING INTO NORTH GEORGIA LATE TONIGHT MAY
SEE SHOWERS DEVELOPING IN THE WEST MIDLANDS/PIEDMONT AND CSRA. THE
LATEST HRRR SUGGESTS CONVECTION ALONG THE GULF COAST MAY SPREAD
NORTHEAST OVERNIGHT ASSOCIATED WITH WEAK SHORT WAVE TROUGH
ROTATING AROUND STACKED LOW OVER THE MIDWEST. SO CHANCE POPS AND
INCREASING FROM SOUTHWEST TO NORTHEAST TOWARD MORNING. INSTABILITY
WEAK TO MODERATE BUT DEEP LAYER SHEAR MAY INCREASE BY DAYBREAK.
USED THE WARMER TEMPERATURE GUIDANCE BECAUSE OF CLOUDINESS AND
MIXING.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
MOISTURE SHOULD BECOME DEEP JUST AHEAD OF THE SLOW MOVING COLD
FRONT. BELIEVE THE FRONT WILL BE JUST WEST OF THE FORECAST AREA
WEDNESDAY AND EXTEND THROUGH THE AREA WEDNESDAY NIGHT. THE NAM
SHOWS PRECIPITABLE WATER INCREASING TO NEAR 1.9 OF AN INCH BY
WEDNESDAY AFTERNOON. SHEAR WILL BE HIGH. THE MODELS INDICATE
A 40-KNOT H85 JET. THE MOISTURE AND CONVERGENCE ASSOCIATED WITH
THE FRONT SUPPORT LIKELY OR CATEGORICAL POPS. THE NAM INDICATES
SURFACE-BASED LI/S NEAR -5 WEDNESDAY AND WEDNESDAY EVENING. THE
INSTABILITY AND SHEAR SUPPORT POSSIBLE SEVERE THUNDERSTORMS. HIGH
PRECIPITABLE WATER AND POSSIBLE TRAINING SUPPORTS HEAVY RAIN. THE
NAM...GFS...AND SREF MEAN ARE ALL BELOW FLASH FLOOD GUIDANCE SO WE
HAVE HELD OFF ISSUING A FLOOD WATCH FOR NOW.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE NAM AND GFS CONTINUE TO INDICATE DEEP MOISTURE WILL SHIFT EAST
OF THE FORECAST AREA EARLY THURSDAY. THE FRONT WILL SHIFT JUST OFF
THE COAST. THE NAM INDICATES SURFACE-BASED LI/S ABOVE 0 BY 12Z
THURSDAY. THE SHOWER CHANCE SHOULD DIMINISH FROM WEST TO EAST. THE
GFS AND ECMWF INDICATE A DRY PATTERN DURING THE REST OF THE
MEDIUM-RANGE PERIOD. MOISTURE ASSOCIATED WITH THE FRONT APPEARS TO
REMAIN SOUTH AND EAST OF THE AREA EARLY. DRY SURFACE RIDGING JUST
TO THE SOUTH APPEARS TO DOMINATE DURING THE MIDDLE AND LATE PART
OF THE PERIOD. THE GFS...ECMWF...AND EKD MOS PLUS GFS ENSEMBLE
MEAN INDICATE POPS AROUND 20 PERCENT EARLY...AND LESS THAN 20
PERCENT DURING THE REST OF THE PERIOD. THE GUIDANCE WAS CONSISTENT
WITH TEMPERATURES NEAR CLIMATOLOGY.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS EXPECTED TO DETERIORATE OVERNIGHT AS COLD FRONT
APPROACHES FROM THE WEST.
CHANCES OF SHOWERS AND STORMS REMAINS LOW ACROSS THE AREA INTO
TONIGHT. AS THE COLD FRONT APPROACHES FROM THE WEST
OVERNIGHT...MOISTURE WILL INCREASE ACROSS THE AREA. EXPECT
CEILINGS TO DETERIORATE TO MVFR BY 06Z AND REMAIN MVFR OR LOWER
THROUGH DAYBREAK. MVFR CEILINGS SHOULD IMPROVE WEDNESDAY MORNING
AND POTENTIAL FOR CONVECTION WILL INCREASE DURING THE DAY. CONFIDENCE
IS LOW REGARDING TIMING SO HAVE USED VCSH FOR WEDNESDAY
MORNING...ALTHOUGH THUNDER WILL BE POSSIBLE DURING THE AFTERNOON.
WINDS WILL BE SOUTHERLY AT AROUND 5 TO 10 KNOTS OVERNIGHT AND WILL
INCREASE WEDNESDAY MORNING TO AROUND 12 KNOTS WITH GUSTS UP TO 20
KNOTS.
.EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN SHOWERS AND
THUNDERSTORMS THROUGH THURSDAY NIGHT AS THE FRONTAL SYSTEM SLOWLY
CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
915 PM EDT TUE APR 29 2014
.UPDATE...
COLD FRONT CURRENTLY STRETCHES FROM NW AL BACK THROUGH CENTRAL LA.
WIDESPREAD SHOWERS WITH EMBEDDED THUNDERSTORMS ARE APPROACHING THE
GA/AL LINE...AND WILL SPREAD EASTWARD THIS EVENING AND INTO THE
OVERNIGHT HOURS. LARGE COMPLEX THAT STRETCHES FROM THE MISSISSIPPI
COAST TO THE FLORIDA PANHANDLE SEEMS TO HAVE CUT OFF MUCH OF THE
INFLOW TO ANY STORMS FURTHER NORTH. RADAR TRENDS OVER THE LAST FEW
HOURS HAVE SHOWN A FEW STRONG STORMS WITHIN THE WIDESPREAD
RAINFALL...BUT NO WARNINGS FOR THE LAST LITTLE BIT.
ATMOS ISNT QUITE AS CONDUCIVE TO WIDESPREAD SEVERE WEATHER. A
FEW STRONG OR ISOLATED SEVERE STORMS WILL CONTINUE TO BE
POSSIBLE...BUT AM GOING TO REMOVE THE WORDING FROM THE PUBLIC
PRODUCTS. WILL STILL HIGHLIGHT THE POTENTIAL FOR ISOLATED
STRONG/SEVERE WITHIN THE HWO. DO THINK THE PRIMARY HAZARD WILL BE
LOCALLY HEAVY RAINFALL.
&&
.PREV DISCUSSION... /ISSUED 739 PM EDT TUE APR 29 2014/
PREV DISCUSSION... /ISSUED 352 PM EDT TUE APR 29 2014/
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
MAIN CONCERN WILL BE WITH SEVERE POTENTIAL THIS EVENING INTO THE
OVERNIGHT WITH THE ANTICIPATED NEXT WAVE OF CONVECTION. THE DAYTIME
PERIOD HAS BEEN LARGELY A LULL IN ACTIVITY DUE TO UPSTREAM
CONVECTION ALONG NORTHERN FLORIDA AND CAPPING FROM LINGERING
MIDLEVEL CLOUD COVERAGE THAT HAS FINALLY STARTED TO MIX OUT. OUT OF
THE SUITE OF HI-RES SOLUTIONS...THE RUC...LOCAL WRF...AND HRRR HAVE
BEEN TRENDING THE BEST WITH PREVIOUS DEVELOPMENT AND LACK THEREOF SO
HAVE LEANED HEAVILY TOWARD THEM WITH OVERNIGHT POPS AND GREATEST
STORM POTENTIAL. THESE MODELS AGREE WITH CONVECTIVE INITIATION
OCCURRING NEAR THE MS/AL BORDER BY 20-21Z...WHICH SEEMS LEGIT GIVEN
AN OBSERVED MESO-LOW TRACKING ALONG THE SFC FRONT IN SOUTHERN MS AND
ALREADY SEEING SOME ENHANCED CU FIELD DEVELOPING. THE EVOLUTION OF
DEVELOPMENT BRINGS CELLS INTO WESTERN PORTIONS OF THE CWA AFTER 00Z
TONIGHT THEN SPREADING NORTH OF THE I-85 CORRIDOR.
THE INSTABILITY AND SHEAR PARAMETERS ARE STILL QUITE FAVORABLE FOR
STRONG TO SEVERE DEVELOPMENT THIS EVENING AND EARLY MORNING WITH
DAMAGING WINDS AND TORNADOES AS THE MAIN THREATS. MLCAPE VALUES ARE
LOOKING TO BE NEAR 1000 J/KG...0-1KM HELICITY AROUND 150
M2/S2...0-1KM BULK SHEAR NEAR 30 KTS...AND 0-6KM BULK IN THE 50-60
KT ZONE FOR THE NORTHWEST HALF OF THE AREA. THE BEST CHANCE FOR
SEVERE DEVELOPMENT LOOKS TO BE IN THE 01Z-07Z PERIOD ALONG AND NORTH
OF THE I-85 CORRIDOR INCLUDING THE ATLANTA METRO AREA. THIS ALSO
COINCIDES WITH INCREASING SREF ENSEMBLE MEAN STP VALUES APPROACHING
2. SHEAR VECTOR ORIENTATION SUPPORTS EMBEDDED OR SEMI-DISCRETE
SUPERCELL CONVECTIVE MODE IN THE 00Z-09Z PERIOD...THEN BECOMES MORE
PARALLEL AS A MORE LINEAR SWATH SETS UP. THIS AGREES WITH CONSENSUS
AMONG THE MODELS AS TRAINING CELLS STALLING ALONG THE I-85 CORRIDOR
IN THE MORNING HOURS IS POSSIBLE. THERE COULD THEREFORE BE AN
INCREASED FLASH FLOODING THREAT. SEE HYDRO SECTION BELOW FOR MORE
DETAILS ON QPF WITH THE EVENT.
THE FRONT FINALLY PUSHES THROUGH WEDNESDAY THOUGH THE ENVIRONMENT
LOOKS LESS FAVORABLE THAN OVERNIGHT TONIGHT FOR SEVERE POTENTIAL.
WHILE THE GREATEST POPS WILL TRANSITION TO SOUTHEAST CWA FOR
WEDNESDAY AFTERNOON...CANNOT RULE OUT SOME STRONG TO ISOLATED SEVERE
POTENTIAL ATTM.
BAKER
LONG TERM /THURSDAY THROUGH TUESDAY/...
NO MAJOR CHANGES MADE TO THE EXTENDED FORECAST. THE COLD FRONT
BRINGING SEVERE WEATHER TO THE STATE IN THE SHORT TERM IS EXPECTED
TO EXIT THE AREA LATE WEDNESDAY NIGHT..ENDING THE THREAT OF SEVERE
STORMS. THE DIFFICULTY THEN BECOMES THE SW UPPER FLOW CONTINUES
THROUGH ABOUT 12Z SAT WITH POTENTIAL FOR MAINLY LIGHT SHOWER AND
THUNDERSTORM CHANCES OVER MAINLY SE PORTION OF THE CWA AS SOME
LESSER MOISTURE MOVES THROUGH THE FLOW. AFTER 12Z SAT THE UPPER
TROUGH MOVES ACROSS THE AREA WITH A DRY FORECAST FOR THE REST OF
THE LONG TERM.
TEMPERATURES WILL TRANSITION TO BELOW NORMAL AT THE START OF THE
LONG TERM THEN BACK TO NORMAL ON SATURDAY AND THEN ABOVE NORMAL THE
REST OF THE LONG TERM.
01
HYDROLOGY...
HPC QPF LOOKS REASONABLE GIVEN THE AFOREMENTIONED STORM TRENDS IN
THE HI-RES SOLUTIONS. THE HEAVIEST AMOUNTS LOOK TO FALL IN THE
OVERNIGHT PERIOD TONIGHT WITH A WIDESPREAD 2 INCHES AND POSSIBLY
HIGHER AMOUNTS WITH TRAINING CELLS ALONG AND NEAR THE I-85 CORRIDOR.
WILL KEEP THE CURRENT FLOOD WATCH GOING THROUGH WEDNESDAY NIGHT.
BAKER
AVIATION...
00Z UPDATE...
CHALLENGING TAF FORECAST FOR THE NEXT 24 HOURS. HI-RES MODELS ARE
NOT IN AGREEMENT WITH THE EVOLUTION OF THE TONIGHT/WED MORNING
SYSTEM. HRRR SEEMS NOT TO HAVE INITIALIZED SOME OF THE CONVECTION
TO THE SW VERY WELL...SO WEIGHTED A HI-RES BLEND TOWARDS THE LOCAL
RUN OF THE WRF.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM-LOW CONFIDENCE ON CONVECTION TIMING. MEDIUM-HIGH CONFIDENCE
REMAINING ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 65 78 55 74 / 70 80 50 20
ATLANTA 65 75 53 71 / 80 60 20 10
BLAIRSVILLE 61 70 50 67 / 100 70 20 10
CARTERSVILLE 66 76 49 71 / 100 60 10 10
COLUMBUS 68 80 57 74 / 70 60 40 20
GAINESVILLE 64 75 53 70 / 90 70 30 10
MACON 68 82 58 75 / 50 70 60 30
ROME 65 76 48 70 / 90 60 10 10
PEACHTREE CITY 65 76 51 72 / 80 60 20 20
VIDALIA 70 86 67 78 / 50 60 60 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH LATE WEDNESDAY NIGHT FOR THE FOLLOWING
ZONES: BALDWIN...BANKS...BARROW...BARTOW...BIBB...BLECKLEY...
BUTTS...CARROLL...CATOOSA...CHATTAHOOCHEE...CHATTOOGA...
CHEROKEE...CLARKE...CLAYTON...COBB...COWETA...CRAWFORD...CRISP...
DADE...DAWSON...DEKALB...DODGE...DOOLY...DOUGLAS...EMANUEL...
FANNIN...FAYETTE...FLOYD...FORSYTH...GILMER...GLASCOCK...
GORDON...GREENE...GWINNETT...HALL...HANCOCK...HARALSON...
HARRIS...HEARD...HENRY...HOUSTON...JACKSON...JASPER...
JEFFERSON...JOHNSON...JONES...LAMAR...LAURENS...LUMPKIN...
MACON...MADISON...MARION...MERIWETHER...MONROE...MONTGOMERY...
MORGAN...MURRAY...MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...
OGLETHORPE...PAULDING...PEACH...PICKENS...PIKE...POLK...
PULASKI...PUTNAM...ROCKDALE...SCHLEY...SOUTH FULTON...SPALDING...
STEWART...SUMTER...TALBOT...TALIAFERRO...TAYLOR...TELFAIR...
TOOMBS...TOWNS...TREUTLEN...TROUP...TWIGGS...UNION...UPSON...
WALKER...WALTON...WARREN...WASHINGTON...WEBSTER...WHEELER...
WHITE...WHITFIELD...WILCOX...WILKES...WILKINSON.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
823 PM EDT TUE APR 29 2014
.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM WILL APPROACH FROM THE WEST THROUGH
WEDNESDAY. THE FRONT WILL EXTEND THROUGH THE FORECAST AREA
WEDNESDAY NIGHT AND MOVE EAST OF THE AREA THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
DEEP MOISTURE LACKING ACROSS THE AREA EARLY THIS EVENING.
BASED ON LATEST GUIDANCE WILL LOWER POPS THROUGH MIDNIGHT...WITH
CHANCE MAINLY ALONG THE NORTH CAROLINA BORDER NEAR STATIONARY
FRONT. WITH COLD FRONT MOVING INTO NORTH GEORGIA LATE TONIGHT MAY
SEE SHOWERS DEVELOPING IN THE WEST MIDLANDS/PIEDMONT AND CSRA. THE
LATEST HRRR SUGGESTS CONVECTION ALONG THE GULF COAST MAY SPREAD
NORTHEAST OVERNIGHT ASSOCIATED WITH WEAK SHORT WAVE TROUGH
ROTATING AROUND STACKED LOW OVER THE MIDWEST. SO CHANCE POPS AND
INCREASING FROM SOUTHWEST TO NORTHEAST TOWARD MORNING. INSTABILITY
WEAK TO MODERATE BUT DEEP LAYER SHEAR MAY INCREASE BY DAYBREAK.
USED THE WARMER TEMPERATURE GUIDANCE BECAUSE OF CLOUDINESS AND
MIXING.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
MOISTURE SHOULD BECOME DEEP JUST AHEAD OF THE SLOW MOVING COLD
FRONT. BELIEVE THE FRONT WILL BE JUST WEST OF THE FORECAST AREA
WEDNESDAY AND EXTEND THROUGH THE AREA WEDNESDAY NIGHT. THE NAM
SHOWS PRECIPITABLE WATER INCREASING TO NEAR 1.9 OF AN INCH BY
WEDNESDAY AFTERNOON. SHEAR WILL BE HIGH. THE MODELS INDICATE
A 40-KNOT H85 JET. THE MOISTURE AND CONVERGENCE ASSOCIATED WITH
THE FRONT SUPPORT LIKELY OR CATEGORICAL POPS. THE NAM INDICATES
SURFACE-BASED LI/S NEAR -5 WEDNESDAY AND WEDNESDAY EVENING. THE
INSTABILITY AND SHEAR SUPPORT POSSIBLE SEVERE THUNDERSTORMS. HIGH
PRECIPITABLE WATER AND POSSIBLE TRAINING SUPPORTS HEAVY RAIN. THE
NAM...GFS...AND SREF MEAN ARE ALL BELOW FLASH FLOOD GUIDANCE SO WE
HAVE HELD OFF ISSUING A FLOOD WATCH FOR NOW.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE NAM AND GFS CONTINUE TO INDICATE DEEP MOISTURE WILL SHIFT EAST
OF THE FORECAST AREA EARLY THURSDAY. THE FRONT WILL SHIFT JUST OFF
THE COAST. THE NAM INDICATES SURFACE-BASED LI/S ABOVE 0 BY 12Z
THURSDAY. THE SHOWER CHANCE SHOULD DIMINISH FROM WEST TO EAST. THE
GFS AND ECMWF INDICATE A DRY PATTERN DURING THE REST OF THE
MEDIUM-RANGE PERIOD. MOISTURE ASSOCIATED WITH THE FRONT APPEARS TO
REMAIN SOUTH AND EAST OF THE AREA EARLY. DRY SURFACE RIDGING JUST
TO THE SOUTH APPEARS TO DOMINATE DURING THE MIDDLE AND LATE PART
OF THE PERIOD. THE GFS...ECMWF...AND EKD MOS PLUS GFS ENSEMBLE
MEAN INDICATE POPS AROUND 20 PERCENT EARLY...AND LESS THAN 20
PERCENT DURING THE REST OF THE PERIOD. THE GUIDANCE WAS CONSISTENT
WITH TEMPERATURES NEAR CLIMATOLOGY.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS EXPECTED TO DETERIORATE OVERNIGHT AS COLD FRONT
APPROACHES FROM THE WEST.
STORM ACTIVITY FOCUSED ALONG THE GULF COAST HAS CUT OFF MOISTURE
IN OUR AREA THIS AFTERNOON AND EVENING. CHANCES OF SHOWERS AND
STORMS REMAINS LOW ACROSS THE AREA INTO TONIGHT. CURRENT REGIONAL
RADAR LOOP SHOWS AN AREA OF SHOWERS AND STORMS EXTENDING FROM
SOUTHWEST GEORGIA INTO THE FLORIDA PANHANDLE WHICH MAY AFFECT THE
AREA OVERNIGHT. AS THE COLD FRONT APPROACHES FROM THE WEST
OVERNIGHT...MOISTURE AND THE CHANCE FOR SHOWERS WILL INCREASE.
EXPECT CEILINGS TO DETERIORATE TO MVFR BY 04Z AND REMAIN MVFR
OR LOWER THROUGH MUCH OF THE TAF PERIOD. MAY SEE TEMPORARY
IMPROVEMENT AT OGB WITH IT BEING LOCATED FURTHER EAST. WINDS WILL
BE SOUTHERLY AT AROUND 5 TO 10 KNOTS OVERNIGHT AND INCREASING
WEDNESDAY MORNING TO AROUND 12 KNOTS WITH GUSTS UP TO 20 KNOTS.
.EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN SHOWERS AND
THUNDERSTORMS THROUGH THURSDAY NIGHT AS THE FRONTAL SYSTEM SLOWLY
CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
739 PM EDT TUE APR 29 2014
.PREV DISCUSSION... /ISSUED 352 PM EDT TUE APR 29 2014/
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
MAIN CONCERN WILL BE WITH SEVERE POTENTIAL THIS EVENING INTO THE
OVERNIGHT WITH THE ANTICIPATED NEXT WAVE OF CONVECTION. THE DAYTIME
PERIOD HAS BEEN LARGELY A LULL IN ACTIVITY DUE TO UPSTREAM
CONVECTION ALONG NORTHERN FLORIDA AND CAPPING FROM LINGERING
MIDLEVEL CLOUD COVERAGE THAT HAS FINALLY STARTED TO MIX OUT. OUT OF
THE SUITE OF HI-RES SOLUTIONS...THE RUC...LOCAL WRF...AND HRRR HAVE
BEEN TRENDING THE BEST WITH PREVIOUS DEVELOPMENT AND LACK THEREOF SO
HAVE LEANED HEAVILY TOWARD THEM WITH OVERNIGHT POPS AND GREATEST
STORM POTENTIAL. THESE MODELS AGREE WITH CONVECTIVE INITIATION
OCCURRING NEAR THE MS/AL BORDER BY 20-21Z...WHICH SEEMS LEGIT GIVEN
AN OBSERVED MESO-LOW TRACKING ALONG THE SFC FRONT IN SOUTHERN MS AND
ALREADY SEEING SOME ENHANCED CU FIELD DEVELOPING. THE EVOLUTION OF
DEVELOPMENT BRINGS CELLS INTO WESTERN PORTIONS OF THE CWA AFTER 00Z
TONIGHT THEN SPREADING NORTH OF THE I-85 CORRIDOR.
THE INSTABILITY AND SHEAR PARAMETERS ARE STILL QUITE FAVORABLE FOR
STRONG TO SEVERE DEVELOPMENT THIS EVENING AND EARLY MORNING WITH
DAMAGING WINDS AND TORNADOES AS THE MAIN THREATS. MLCAPE VALUES ARE
LOOKING TO BE NEAR 1000 J/KG...0-1KM HELICITY AROUND 150
M2/S2...0-1KM BULK SHEAR NEAR 30 KTS...AND 0-6KM BULK IN THE 50-60
KT ZONE FOR THE NORTHWEST HALF OF THE AREA. THE BEST CHANCE FOR
SEVERE DEVELOPMENT LOOKS TO BE IN THE 01Z-07Z PERIOD ALONG AND NORTH
OF THE I-85 CORRIDOR INCLUDING THE ATLANTA METRO AREA. THIS ALSO
COINCIDES WITH INCREASING SREF ENSEMBLE MEAN STP VALUES APPROACHING
2. SHEAR VECTOR ORIENTATION SUPPORTS EMBEDDED OR SEMI-DISCRETE
SUPERCELL CONVECTIVE MODE IN THE 00Z-09Z PERIOD...THEN BECOMES MORE
PARALLEL AS A MORE LINEAR SWATH SETS UP. THIS AGREES WITH CONSENSUS
AMONG THE MODELS AS TRAINING CELLS STALLING ALONG THE I-85 CORRIDOR
IN THE MORNING HOURS IS POSSIBLE. THERE COULD THEREFORE BE AN
INCREASED FLASH FLOODING THREAT. SEE HYDRO SECTION BELOW FOR MORE
DETAILS ON QPF WITH THE EVENT.
THE FRONT FINALLY PUSHES THROUGH WEDNESDAY THOUGH THE ENVIRONMENT
LOOKS LESS FAVORABLE THAN OVERNIGHT TONIGHT FOR SEVERE POTENTIAL.
WHILE THE GREATEST POPS WILL TRANSITION TO SOUTHEAST CWA FOR
WEDNESDAY AFTERNOON...CANNOT RULE OUT SOME STRONG TO ISOLATED SEVERE
POTENTIAL ATTM.
BAKER
LONG TERM /THURSDAY THROUGH TUESDAY/...
NO MAJOR CHANGES MADE TO THE EXTENDED FORECAST. THE COLD FRONT
BRINGING SEVERE WEATHER TO THE STATE IN THE SHORT TERM IS EXPECTED
TO EXIT THE AREA LATE WEDNESDAY NIGHT..ENDING THE THREAT OF SEVERE
STORMS. THE DIFFICULTY THEN BECOMES THE SW UPPER FLOW CONTINUES
THROUGH ABOUT 12Z SAT WITH POTENTIAL FOR MAINLY LIGHT SHOWER AND
THUNDERSTORM CHANCES OVER MAINLY SE PORTION OF THE CWA AS SOME
LESSER MOISTURE MOVES THROUGH THE FLOW. AFTER 12Z SAT THE UPPER
TROUGH MOVES ACROSS THE AREA WITH A DRY FORECAST FOR THE REST OF
THE LONG TERM.
TEMPERATURES WILL TRANSITION TO BELOW NORMAL AT THE START OF THE
LONG TERM THEN BACK TO NORMAL ON SATURDAY AND THEN ABOVE NORMAL THE
REST OF THE LONG TERM.
01
HYDROLOGY...
HPC QPF LOOKS REASONABLE GIVEN THE AFOREMENTIONED STORM TRENDS IN
THE HI-RES SOLUTIONS. THE HEAVIEST AMOUNTS LOOK TO FALL IN THE
OVERNIGHT PERIOD TONIGHT WITH A WIDESPREAD 2 INCHES AND POSSIBLY
HIGHER AMOUNTS WITH TRAINING CELLS ALONG AND NEAR THE I-85 CORRIDOR.
WILL KEEP THE CURRENT FLOOD WATCH GOING THROUGH WEDNESDAY NIGHT.
BAKER
&&
.AVIATION...
00Z UPDATE...
CHALLENGING TAF FORECAST FOR THE NEXT 24 HOURS. HI-RES MODELS ARE
NOT IN AGREEMENT WITH THE EVOLUTION OF THE TONIGHT/WED MORNING
SYSTEM. HRRR SEEMS NOT TO HAVE INITIALIZED SOME OF THE CONVECTION
TO THE SW VERY WELL...SO WEIGHTED A HI-RES BLEND TOWARDS THE LOCAL
RUN OF THE WRF.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM-LOW CONFIDENCE ON CONVECTION TIMING. MEDIUM-HIGH CONFIDENCE
REMAINING ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 65 78 55 74 / 70 80 50 20
ATLANTA 65 75 53 71 / 80 60 20 10
BLAIRSVILLE 61 70 50 67 / 100 70 20 10
CARTERSVILLE 66 76 49 71 / 100 60 10 10
COLUMBUS 68 80 57 74 / 70 60 40 20
GAINESVILLE 64 75 53 70 / 90 70 30 10
MACON 68 82 58 75 / 50 70 60 30
ROME 65 76 48 70 / 90 60 10 10
PEACHTREE CITY 65 76 51 72 / 80 60 20 20
VIDALIA 70 86 67 78 / 50 60 60 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH LATE WEDNESDAY NIGHT FOR THE FOLLOWING
ZONES: BALDWIN...BANKS...BARROW...BARTOW...BIBB...BLECKLEY...
BUTTS...CARROLL...CATOOSA...CHATTAHOOCHEE...CHATTOOGA...
CHEROKEE...CLARKE...CLAYTON...COBB...COWETA...CRAWFORD...CRISP...
DADE...DAWSON...DEKALB...DODGE...DOOLY...DOUGLAS...EMANUEL...
FANNIN...FAYETTE...FLOYD...FORSYTH...GILMER...GLASCOCK...
GORDON...GREENE...GWINNETT...HALL...HANCOCK...HARALSON...
HARRIS...HEARD...HENRY...HOUSTON...JACKSON...JASPER...
JEFFERSON...JOHNSON...JONES...LAMAR...LAURENS...LUMPKIN...
MACON...MADISON...MARION...MERIWETHER...MONROE...MONTGOMERY...
MORGAN...MURRAY...MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...
OGLETHORPE...PAULDING...PEACH...PICKENS...PIKE...POLK...
PULASKI...PUTNAM...ROCKDALE...SCHLEY...SOUTH FULTON...SPALDING...
STEWART...SUMTER...TALBOT...TALIAFERRO...TAYLOR...TELFAIR...
TOOMBS...TOWNS...TREUTLEN...TROUP...TWIGGS...UNION...UPSON...
WALKER...WALTON...WARREN...WASHINGTON...WEBSTER...WHEELER...
WHITE...WHITFIELD...WILCOX...WILKES...WILKINSON.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
620 AM EDT MON APR 28 2014
.SYNOPSIS...
ATLANTIC HIGH PRESSURE EARLY THIS WEEK WILL DIMINISH AHEAD OF A
SLOW MOVING COLD FRONT...BRINGING UNSETTLED WEATHER FOR THE
MIDDLE OF THE WEEK. THE FRONT WILL THEN LINGER JUST OFFSHORE
THROUGH LATE IN THE WEEK...BEFORE HIGH PRESSURE BUILDS INTO THE
REGION BY NEXT SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
28/09Z RAP SOUNDINGS DEPICTED AN EVEN WEAKER CAP ACROSS INTERIOR
SOUTHEAST SOUTH CAROLINA AHEAD OF THE SEA BREEZE. HAVE OPTED TO
INCLUDE A SLIGHT CHANCE OF SHOWERS/TSTMS FOR A FEW HOURS THIS
AFTERNOON GIVEN THIS TREND. NO OTHER CHANGES WERE MADE TO THE
GOING FORECAST.
A CLASSIC OMEGA BLOCKING PATTERN WILL REMAIN IN TACT ACROSS THE
EASTERN HALF OF THE U.S. TODAY WITH A STRONG AND QUITE PRONOUNCED
UPPER RIDGE CENTERED DIRECTLY OVER THE SOUTHEAST STATES. AT THE
SURFACE...THE AREA IS LOCATED ALONG THE WESTERN FLANKS OF ATLANTIC
HIGH PRESSURE...WHICH IS HELPING TO KEEP ELEVATED DEWPOINTS IN THE
60S IN PLACE. TODAY HAS THE POTENTIAL TO BE THE WARMEST DAY SO FAR
THIS YEAR WITH VARIOUS GUIDANCE TRENDS AND LOW-LEVEL THICKNESSES
SCHEMES SUPPORTING HIGHS IN THE UPPER 80S TO LOWER 90S AWAY FROM
THE BEACHES. THE DEGREE OF WARMTH WILL BE HEAVILY INFLUENCED BY
THE AMOUNT OF CLOUD COVER TODAY. THIN CIRRIFORM CLOUDS TRAVERSING
THE FORECAST AREA THIS MORNING WILL GRADUALLY SHIFT NORTH WITH
BOTH THE CMC AND NAM SIMULATED CLOUD PRODUCTS SHOWING SKIES
CLEARING LATER THIS MORNING. THE RESULTING STRONG INSOLATION AND
60+ DEGREE DEWPOINTS WILL PROMOTE A SHALLOW CUMULUS FIELD FORMING
AHEAD OF THE SEA BREEZE BY THIS AFTERNOON WITH ANOTHER BATCH OF
MID/HIGH-LEVEL CLOUDS STREAMING BACK IN FROM THE WEST CLOSER TO
SUNSET. THE RESULTANT SEA BREEZE CIRCULATION IS EXPECTED TO REACH
THE I-95 CORRIDOR BY MID-AFTERNOON AND FAR INLAND AREAS LATE.
RAP/NAM SOUNDINGS SHOW A PRONOUNCED SUBSIDENCE INVERSION
ASSOCIATED WITH THE MID/UPPER-LEVEL RIDGE AXIS. THIS INVERSION IS
FORECAST TO HOLD FOR MUCH OF THE DAY...DESPITE TEMPERATURES
WARMING TO NEAR 90 DEGREES. THERE ARE SOME SIGNALS THAT THE CAP
MAY WEAKEN JUST ENOUGH ACROSS THE NORTHERN HALF OF THE FORECAST
AREA TO SUPPORT AN ISOLATED SHOWER/TSTM ALONG THE BROAD LOW-LEVEL
CONVERGENCE ZONE ASSOCIATED WITH THE THERMALLY DIRECT SEA BREEZE
CIRCULATION...BUT MOST OF THE HIGHER RESOLUTION MODEL RUNS SHOW
LITTLE...IF ANY...QPF. SINCE THE MODELS HAVE BEEN TOO AGGRESSIVE
WITH CONVECTIVE DEVELOPMENT WITHIN THIS SUBSIDENT REGIME OVER THE
PAST FEW DAYS...POPS WILL BE HELD BELOW MENTIONABLE THRESHOLDS FOR
THE AFTERNOON HOURS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...THE RESULTANT SEA BREEZE WILL CLEAR THE FAR WESTERN
AREAS SHORTLY AFTER SUNSET AS THE AREA REMAINS ALONG THE WESTERN
FLANKS OF ATLANTIC HIGH PRESSURE. LOW-LEVEL WIND FIELDS ARE
FORECAST TO INCREASE OVERNIGHT AS NOCTURNAL JETTING INTENSIFIES
AHEAD OF AN APPROACHING COLD FRONT. THIS SHOULD KEEP THE
ATMOSPHERE FAIRLY WELL MIXED OVERNIGHT AND KEEPING THE BOUNDARY
LAYER FROM FULLY DECOUPLING. THIS WILL RESULT IN A WARM AND FAIRLY
HUMID NIGHT WITH LOWS RANGING FROM THE MID 60S WELL INLAND TO
AROUND 70 ACROSS THE COASTAL COUNTIES. IT WILL BE A DRY NIGHT WITH
ANY SHOWER ACTIVITY THAT DEVELOPS LIKELY REMAINING WELL TO THE WEST
THROUGH SUNRISE AND POSSIBLY OVER THE WESTERN WALL OF THE GULF
STREAM.
TUESDAY...THE AXIS OF THE UPPER RIDGE WILL SHIFT INTO THE NEARBY
ATLANTIC WATERS DURING THE MORNING HOURS...AS A ROBUST STACKED LOW
SYSTEM BEGINS TO BREAK THE OMEGA BLOCKING PATTERN AND MOVE
NORTH/NORTHEAST ACROSS THE MID MISSISSIPPI VALLEY. THE SOUTHEAST
STATES WILL BECOME LOCATED BETWEEN A WARM FRONT LIFTING WELL NORTH
OF THE AREA AND THE COLD FRONT TRAILING FROM THE LOW SYSTEM FAR
UPSTREAM. SOLID SOUTHERLY FLOW WILL CONTINUE TO SUPPORT INCREASING
LOW LEVEL MOISTURE AND WARM TEMPERATURES PEAKING FAR ABOVE
SEASONAL NORMALS. AS A RESULT...DECENT INSTABILITY WILL DEVELOP
TUESDAY AFTERNOON...WHILE MID LEVEL LAPSE RATES INCREASE UP TO 7
C/KM. A BAND OF WEAK SHORTWAVE ENERGY RIDING ALONG THE PERIPHERY
OF THE RETREATING UPPER RIDGE COULD PROVIDE SOME FORCING.
YET WITH STRONGEST DYNAMICS STILL WEST OF THE AREA...BEST
CONVECTIVE COVERAGE WILL BE ACROSS INLAND AREAS...AS THUNDERSTORM
DEVELOPMENT AND INTENSIFICATION WILL BE MAINLY DRIVEN BY SEABREEZE
AND BOUNDARY INTERACTIONS. WILL STILL NEED TO MONITOR FOR THE
POSSIBILITY THAT AN ISOLATED THUNDERSTORM COULD BECOME ORGANIZED
OR SEVERE WITHIN LOW TO MODERATE INSTABILITY AND SOME INCREASE IN
SHEAR PROFILES...ESPECIALLY IF ANY ONGOING UPSTREAM CONVECTION CAN
SLIP INTO THE FAR WESTERN PERIPHERY LATE IN THE DAY. CONSIDERING
THE STEADILY INTENSIFYING UPPER LEVEL SUPPORT AHEAD OF THE
IMPRESSIVE LOW SYSTEM TO THE WEST...WILL MAINTAIN SLIGHT TO LOW
CHANCE POPS ACROSS THE FORECAST AREA THROUGH TUESDAY NIGHT.
WEDNESDAY...THE COLD FRONT TRAILING FROM THE MASSIVE LOW SYSTEM
NOW LOCATED ACROSS THE OHIO VALLEY/GREAT LAKES REGION WILL MAKE
SLOW YET GRADUAL PROGRESS EASTWARD. THE FORECAST AREA WILL REMAIN
IN THE WARM SECTOR OF THE APPROACHING SYSTEM...WITH THE SLOW-
MOVING FRONT JUST ALONG THE WESTERN PERIPHERY OF THE AREA BY
DAYBREAK THURSDAY. DESPITE THICK CLOUDS REDUCING INSOLATION AS
WELL AS INCREASING SHOWER/THUNDERSTORM COVERAGE...TEMPERATURES
WILL STILL RISE INTO THE LOW TO MID 80S WITHIN WARM SOUTHERLY
FLOW AND SOME PRE-FRONTAL COMPRESSION EFFECTS. AS BOTH LOW LEVEL
AND UPPER LEVEL JETTING INCREASE ACROSS THE SOUTHEAST AND MID-
ATLANTIC STATES DOWNSTREAM OF THE UPPER TROUGH AXIS...SHEAR WILL
ALSO INCREASE ACROSS THE AREA AT THE SAME TIME THAT MID LEVEL
LAPSE RATES REACH 7 TO 7.5 C/KM. THUNDERSTORM COVERAGE WILL BE
HIGHEST LATE WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...WITH
RAIN CHANCES UP TO 50 PERCENT DURING THIS TIME FRAME. CONSIDERING
SUCH A STRONGLY DYNAMIC SYSTEM...THERE IS STILL A POTENTIAL FOR
ISOLATED THUNDERSTORMS TO BECOME SEVERE...ESPECIALLY WHERE
BOUNDARY INTERACTIONS OCCUR AND ENHANCE UPDRAFT STRENGTH. THE MAIN
LIMITING FACTOR WOULD BE SUPPRESSED INSTABILITY IN AREAS OF THICK
CLOUD COVER AND HEAVY RAIN.
THURSDAY...THE COLD FRONT WILL SLOWLY PROGRESS THROUGH THE
FORECAST AREA AND INTO THE COASTAL WATERS THROUGH THE DAY. IT
APPEARS THAT THE BULK OF THE CONVECTION WILL HAVE OCCURRED AHEAD
OF THE ACTUAL FRONT...AND THUS RAIN COVERAGE WILL BE DOWN TO
SCATTERED OR EVEN ISOLATED AS THE FRONT MOVES THROUGH REGION.
PROGRESSION OF THE FEATURE APPEARS TO SLOW EVEN FURTHER LATE IN
THE DAY...ALLOWING CONVERGENCE AND DEEP MOISTURE ALONG THE
FRONTAL ZONE TO LINGER ALONG COASTAL AREAS THROUGH THE NIGHTTIME
HOURS. HAVE THUS MAINTAINED SLIGHT TO LOW CHANCE POPS INTO FRIDAY
MORNING. HIGH TEMPERATURES WILL BE SEVERAL DEGREES COOLER THAN
SEEN DURING THE EARLY TO MID WEEK PERIOD...PEAKING IN THE LOW 80S
AWAY FROM THE LOCALLY COOLER COASTLINE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MEDIUM RANGE NUMERICAL MODEL SOLUTIONS ARE COMING INTO BETTER
AGREEMENT REGARDING THE POTENTIAL FOR THE OFFSHORE FRONT TO LINGER
NEARBY THROUGH THURSDAY NIGHT. SHORTWAVE ENERGY WILL SWING ACROSS
THE GULF COAST STATES INTO THE SOUTHEAST REGION ALONG THE BASE OF
THE LONGWAVE UPPER TROUGH...PROVIDING SUFFICIENT ENERGY TO DEVELOP
A WEAK WAVE OF LOW PRESSURE ALONG THE MEANDERING BOUNDARY. AS
THIS OCCURS...CONVECTION WILL ONCE AGAIN SPREAD INLAND ON
FRIDAY...BEFORE THE FRONT IS PULLED OFFSHORE WITH THE SURFACE
WAVE FRIDAY NIGHT. SURFACE HIGH PRESSURE WILL FINALLY BE ABLE TO
BUILD INTO THE REGION...WHILE THE EARLIER HIGHLY AMPLIFIED PATTERN
ALOFT DAMPENS INTO NEARLY ZONAL FLOW BY EARLY NEXT WEEK. RAIN
CHANCES PEAKING IN THE 40 PERCENT RANGE FRIDAY AFTERNOON WILL THEN
STEADILY TREND DOWNWARD FRIDAY NIGHT INTO SATURDAY...WITH POPS
FALLING BELOW 15 PERCENT SATURDAY NIGHT INTO MONDAY.
HIGH TEMPERATURES WILL BE COOLEST ON FRIDAY...PEAKING ONLY IN THE
LOW TO MID 70S...BEFORE TRENDING BACK UP TOWARD SEASONAL NORMALS
IN THE UPPER 70S FOR THE REMAINDER OF THE PERIOD. LOW TEMPERATURES
WILL FALL INTO THE LOW TO MID 50S FRIDAY AND SATURDAY
NIGHTS...THEN ALSO MODERATE A FEW DEGREES FOR THE NIGHTTIME HOURS
EARLY NEXT WEEK.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
VFR.
EXTENDED AVIATION OUTLOOK...THE MOST LIKELY PERIOD WITH FLIGHT
RESTRICTIONS IS WEDNESDAY INTO THURSDAY DUE TO SHRA/TSRA ASSOCIATED
WITH THE NEXT COLD FRONT. BREEZY CONDITIONS BOTH TUESDAY AND
WEDNESDAY AT THE TERMINALS.
&&
.MARINE...
TODAY...NO CONCERNS. SOUTHERLY WIND REGIME WILL PERSIST WITH WINDS
10-15 KT AND SEAS 2-3 FT WITH AN UNDERLYING 1-2 FT 8-9 SECOND
GROUND SWELL.
TONIGHT...WINDS WILL INCREASE IN RESPONSE TO NOCTURNAL JETTING.
MIXING PROFILES WILL NOT BE IDEAL IN THE SOUTHERLY WIND REGIME SO
WINDS WERE CAPPED AT 15-20 KT. SEAS WILL BUILD 3-4 FT NEARSHORE
WATERS AND 4-5 FT OFFSHORE WATERS.
TUESDAY AND WEDNESDAY...THE PRESSURE GRADIENT WILL TIGHTEN AHEAD
OF A SLOW-MOVING COLD FRONT INTO THE MID WEEK PERIOD. EXPECT
SOUTHERLY FLOW TO INCREASE AND SEAS TO BUILD ACCORDINGLY. MIXING
WILL BE SOMEWHAT LIMITED WITHIN THE WARM ADVECTION
REGIME...HOWEVER ENHANCEMENTS FROM THE AFTERNOON SEA BREEZE AND
NOCTURNAL LOW LEVEL JETTING COULD SUPPORT MARGINAL SMALL CRAFT
ADVISORY CONDITIONS AT TIMES...ESPECIALLY IN CHARLESTON HARBOR
AND THE OUTER GEORGIA WATERS.
THURSDAY THROUGH FRIDAY...THE COLD FRONT WILL STRUGGLE TO SHIFT
THROUGH THE WATERS...LIKELY STALLING OVER OR NEAR THE MARINE AREA
LATE IN THE WEEK. ANY LINGERING ADVISORY-LEVEL WINDS OR SEAS WILL
LIKELY WILL END BY THURSDAY MORNING AND REMAIN BELOW CRITERIA FRIDAY.
MARINERS ARE CAUTIONED THAT SOME STRONG OR SEVERE STORMS COULD
IMPACT THE COASTAL WATERS WEDNESDAY AND THURSDAY. REMEMBER TO
MAINTAIN A WEATHER WATCH AND MONITOR NOAA WEATHER RADIO...ALL
HAZARDS.
RIP CURRENTS...MID TO HIGH-END LOW RISK FOR TODAY GIVEN STEADY
ONSHORE WINDS AND A 8 TO OCCASIONAL 9 SECOND 1-2 FT GROUND SWELL.
AN ENHANCED RISK FOR RIP CURRENTS IS POSSIBLE TUESDAY AND PERHAPS
WEDNESDAY GIVEN THE NEW MOON AND STRONGER ONSHORE WINDS.
&&
.TIDES/COASTAL FLOODING...
GIVEN INFLUENCES FROM THE UPCOMING NEW MOON AND AN INCREASING AND
PERSISTENT ONSHORE WINDS...TIDAL DEPARTURES MAY BE ENOUGH TO
RESULT IN SHALLOW COASTAL FLOODING WITH THE EVENING HIGH TIDES
THROUGH EARLY THIS WEEK...MAINLY ACROSS SOUTH COASTAL SOUTH
CAROLINA.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
903 PM CDT TUE APR 29 2014
.DISCUSSION...
902 PM CDT
HAVE DIMINISHED THE POPS OVERNIGHT AND EARLY WEDNESDAY MORNING.
OTHERWISE ONLY MINOR CHANGES WERE MADE TO FORECAST TEMPERATURES.
THE MASSIVE OCCLUDING CYCLONE SPANNING AROUND 2000 MILES FROM WEST
TO EAST IS CENTERED ACROSS THE MIDWEST AND SLOWLY DRIFTING EAST
NORTHEAST THIS EVE. EMBEDDED SHORT WAVE IMPULSES/VORT
CENTERS/500MB COLD AIR POCKETS OF -25C ARE ORBITING AROUND EACH
OTHER AS ALMOST A FUJIWHARA EFFECT. APPROACHING THE AREA NOW IS A
DRIER CORRIDOR BETWEEN THESE IMPULSES...WITH ONE FAIRLY VIGOROUS
SHORT WAVE RESPONSIBLE FOR THE LATE AFTN/EARLY EVE STORMS HAVING
MOVED NORTHEAST OF CHICAGO. THIS NOW DRYING COMBINED WITH LOSING
THE DIURNAL EFFECT SHOULD RESULT IN VERY MINIMAL SHOWER COVERAGE
OVERNIGHT WITH ANY RAIN LIKELY TO BE LIGHT. UNTIL SOME SLIGHT
WARMING LEADS TO INSTABILITY BY LATE MORNING WEDNESDAY...AM
EXPECTING AREAL COVERAGE OF SHOWERS TO REMAIN MINIMAL SO HAVE
DIMINISHED TO SLIGHT CHANCE OF ANY LIGHT SHOWERS PRIOR TO 10 AM.
MTF
&&
.PREV DISCUSSION...
240 PM CDT
ROBUST RIDGE PARKED OVER HUDSON BAY HAS ALLOWED A LOGJAM IN THE FLOW
OF SYSTEMS...WITH THE SFC LOW ANALYZED OVER FAR NORTHWEST IL THIS
AFTERNOON. THIS LOW WILL DRIFT EAST/NORTHEAST OVERNIGHT...PROGGED TO
BE POSITIONED OVER SOUTHCENTRAL WISC ARND DAYBREAK WED.
INSTABILITY HAS BEEN STEADILY PUSHING EAST OF THE CWFA THIS
AFTN...HOWEVER SOME WEAK CONVERGENCE WAS STILL NOTED ACROSS
NORTHWEST IN. BASED ON THE VISIBLE IMAGERY INDICATING FEW CUMULUS
CLOUDS...AND SFC DEW POINTS STEADILY DIMINISHING INTO THE MID
40S...THE CONFIDENCE IN ADDTL THUNDERSTORMS DEVELOPING IS VERY LOW.
HAVE HELD ONTO THE MENTION OF ISOLATED THUNDER THRU LATE THIS AFTN.
WITH ANY CONVECTIVE DEVELOPMENT...THE MAIN CONCERNS WOULD BE BRIEF
WIND GUSTS AND HAIL TO PENNY SIZE.
DEEP LAYERED MOISTURE WILL PERSIST OVERNIGHT...WITH SOME SPOTTY
SHOWERS ROTATING NORTH ACROSS THE FORECAST AREA. TEMPS WILL BE ABLE
TO COOL INTO THE MID/UPR 40S TONIGHT.
WEDNESDAY THROUGH THURSDAY...
THE 500MB VORT WILL REMAIN ACROSS THE REGION...AS THE SFC LOW OVER
SOUTHCENTRAL WISC WEAKENS. GUIDANCE SUGGESTS ANOTHER WEAK VORT LOBE
WILL PIVOT NORTHEAST ACROSS THE REGION. SHOWER COVERAGE SHUD REMAIN
MARGINAL FOR WED...AND WOULD LIKELY SEE MORE DRY PERIODS ON WED THEN
WET. HAVE HELD ONTO THE 30-40% POPS...BUT COULD SEE THIS NEEDING TO
BE TRIMMED BACK FOR AREAS SOUTH OF I-80. BETTER CHC FOR PRECIP
APPEARS TO BE FOCUSED OVER THE NORTHERN CWFA WED.
SFC RIDGE WILL BEGIN TO DRIFT NORTHEAST OF HUDSON BAY...WHICH WILL
ALLOW THE DEEP TROUGH OVER THE GREAT LAKES TO BEGIN LIFTING
NORTHEAST. HOWEVER IT DOES SO VERY SLOWLY...AND WITH CONSIDERABLE
MOISTURE LINGERING ACROSS THE FORECAST AREA THE CHANCES FOR PRECIP
WILL CONTINUE THRU THUR. 500MB TROUGH AXIS WILL CONTINUE TO LIFT
NORTHEAST THUR NIGHT. NOT EXPECTING MANY BREAKS IN THE CLOUDS THRU
MID-WEEK...SO EXPECT TEMPS TO HOLD GENERALLY IN THE 50S.
FRIDAY THROUGH EARLY NEXT WEEK...
WHILE THE BLOCK OVER HUDSON BAY CONTINUES TO DEPART TO THE
NORTHEAST...A HIGH-AMPLITUDE RIDGE OVER ALASKA WILL LIKELY PROLONG
WEAK TROUGHING FOR THE UPPER MIDWEST/GREAT LAKES REGION INTO FRI.
FORTUNATELY OPERATIONAL GUIDANCE IS BEGINNING TO SUGGEST SOME DRYING
WILL TAKE PLACE FRI. AT THIS TIME STILL CARRYING LOW CHC POPS
FRI...BUT WITH MID-LVL HEIGHTS POISED TO BE RISING LATE IN THE DAY
FRI ENOUGH SUBSIDENCE IN THE MID-LVLS COULD PRODUCE DRY CONDS
EARLIER AND RESULT IN A DRY FRI.
ANOTHER SHORTWAVE IS PROGGED TO SLIDE SOUTHEAST FROM CENTRAL CANADA
SAT...AND BRING A BRIEF PERIOD OF SHOWERS OVER THE WEEKEND.
CONFIDENCE IN TIMING/LOCATION OF THIS IS LOW BASED ON CURRENT
GUIDANCE. THEN FOR THE SECOND HALF OF THE WEEKEND THE PERSISTENT
TROUGH OVER THE GREAT LAKES WILL BEGIN TO PUSH EAST WITH WEAK
RIDGING ARRIVING. THIS WILL LIKELY ALLOW WEAK SFC RIDGE AND DRY
CONDS FOR THE START OF NEXT WEEK.
TEMPS WILL SLOWLY RETURN TO NEAR SEASONAL CONDS IN THE 60S FOR THE
SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK...WITH THE EXCEPTION
OF AREAS ADJACENT TO LAKE MICHIGAN WHERE THE NORTHEAST/EAST WINDS
EARLY NEXT WEEK WILL KEEP TEMPS IN THE LOW/MID 50S.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* SHRA THIS EVENING.
* CHANCE OF TSRA THIS EVENING.
* IFR CIGS OVERNIGHT/WEDNESDAY MORNING. MVFR CIGS WEDNESDAY.
* POSSIBLE FOG TONIGHT.
* CHANCE OF SHRA WEDNESDAY MORNING.
* POSSIBLE GUSTY SOUTHWESTERLY WINDS WEDNESDAY AFTERNOON. CMS
//DISCUSSION...UPDATED 00Z...
A LINE OF SHOWERS WITH EMBEDDED TSRA CONTINUES TO LIFT NORTHEAST
FROM TIP TO IKK TO GYY. SHORT TERM/HIGH RES GUIDANCE CONTINUES TO
HAVE A GOOD HANDLE ON THIS ACTIVITY SHOWING THE STRONGEST CELLS
PASSING JUST EAST OF ORD AND POSSIBLY IMPACTING MDW OVER THE NEXT
HOUR OR TWO AND HAVE OPTED TO CONTINUE VCTS MENTION FOR NOW AND
WILL NEED TO MONITOR TRENDS THIS EVENING. ADDITIONAL SHOWERS
DEVELOPING ACROSS PARTS OF CENTRAL IL WILL ALSO LIFT NORTH AS WELL
AS CONTINUED SHOWERS ACROSS NORTHWEST IL. WHILE THIS ACTIVITY MAY
BE LIGHT IN MANY AREAS...HAVE CONTINUED PREVAILING SHOWER MENTION
WITH THIS FORECAST THROUGH MID EVENING WITH THE POTENTIAL FOR
ADDITIONAL SHOWERS LATE THIS EVENING INTO THE EARLY MORNING HOURS.
A BROAD AREA OF LOW PRESSURE OVER EASTERN IA WILL LIFT NORTHEAST
ACROSS NORTHERN IL AND SOUTHERN WI TONIGHT. AS IT DOES...LOWER
CIGS OVER EASTERN IA WILL SHIFT EAST. FAIRLY CONFIDENT IFR CIGS
WILL SPREAD ACROSS RFD THIS EVENING BUT HOW FAR AND HOW FAST THESE
LOWER CIGS SPREAD ACROSS NORTHEAST IL AND THE CHICAGO TERMINALS IS
SOMEWHAT UNCERTAIN. FOR NOW...HAVE MAINTAINED PREVIOUS IFR CIGS
AND TIMING BUT CHANGES ARE POSSIBLE AS TRENDS EMERGE THIS EVENING
AND OVERNIGHT. CIGS ARE THEN EXPECTED TO LIFT THROUGH MVFR
WEDNESDAY MORNING AND EVENTUALLY BECOMING VFR IN THE AFTERNOON.
WEST/SOUTHWEST WINDS ARE EXPECTED TO TURN MORE SOUTHERLY THIS
EVENING WITH SPEEDS DIMINISHING WELL UNDER 10KTS OVERNIGHT. TIMING
AND CONFIDENCE HERE IS ALSO A BIT UNCERTAIN THOUGH ANY REMAINING
GUSTS SHOULD DIMINISH QUICKLY WITH SUNSET. WINDS ARE EXPECTED TO
GO BACK SOUTHWESTERLY WEDNESDAY WITH SOME GUSTS INTO THE MID/UPPER
TEEN RANGE POSSIBLE. CMS
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM FOR SHRA THIS EVENING.
* LOW FOR TSRA THIS EVENING.
* LOW TO MEDIUM FOR CIG TRENDS OVERNIGHT/WEDNESDAY.
* LOW FOR FOG OVERNIGHT.
* LOW FOR SHRA WEDNESDAY MORNING.
* MEDIUM FOR WINDS THROUGH THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY THROUGH SUNDAY...CHANCE OF SHRA. MVFR CIGS POSSIBLE.
* MONDAY...DRY/VFR.
&&
.MARINE...
217 PM CDT
A VERY SLOW MOVING AREA OF SURFACE LOW PRESSURE CONTINUES TO FILL
ACROSS EASTERN IOWA THIS AFTERNOON...WITH A WARM FRONT EXTENDING
EAST ACROSS NORTHERN ILLINOIS AND FAR SOUTHERN LAKE MICHIGAN. THE
SURFACE PRESSURE GRADIENT ACROSS LAKE MICHIGAN WILL CONTINUE TO
WEAKEN AS THE LOW AND WARM FRONT DRIFT TO THE NORTHEAST TONIGHT...
RESULTING IN DECREASING WINDS ACROSS THE LAKE. EAST-NORTHEAST WINDS
WILL VEER TO THE SOUTH-SOUTHEAST AS THE WARM FRONT LIFTS NORTH
THROUGH WEDNESDAY...BEFORE SHIFTING WEST-SOUTHWEST THURSDAY AS THE
LOW PASSES TO THE NORTHEAST AND TRAILS A WEAK COLD FRONT ACROSS THE
LAKE. MOIST LOW LEVEL AIR OVER THE COOL LAKE WATERS WILL LEAD TO
AREAS OF FOG...WHICH MAY BE DENSE AT TIMES...UNTIL THE COLD FRONT
MOVES EAST OF THE LAKE AND DRIER WESTERLY FLOW DEVELOPS THURSDAY.
MODEST WEST WINDS WILL THEN CONTINUE INTO THE WEEKEND BEFORE A WEAK
HIGH PRESSURE RIDGE PASSES LATE SUNDAY/SUNDAY NIGHT. EAST WINDS ARE
THEN EXPECTED TO DEVELOP MONDAY AS THE RIDGE MOVES OFF TO THE EAST.
FOR THE ILLINOIS AND INDIANA NEARSHORE AREAS...VARIOUS WEB CAMS
NEAR/ALONG THE ILLINOIS SHORE SHOW VISIBILITY IMPROVING
SIGNIFICANTLY AT MID-AFTERNOON AND WILL BE CANCELLING DENSE FOG
ADVISORY SHORTLY. WILL MAINTAIN THE SMALL CRAFT ADVISORY FOR THE
INDIANA SHORE...WITH SOUTHWEST WINDS GUSTING AROUND 30 KT BEHIND
WARM FRONT CURRENTLY. WINDS SHOULD DIMINISH FAIRLY QUICKLY BY EARLY
EVENING HOWEVER WITH WEAKENING GRADIENT AND LOSS OF STEEP LOW LEVEL
LAPSE RATES OVER ADJACENT LAND.
RATZER
&&
.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
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
837 PM CDT Tue Apr 29 2014
.DISCUSSION...
ISSUED 837 PM CDT Tue Apr 29 2014
Band of showers and storms that set up earlier from Taylorville to
Rantoul has faded quite a bit, with remnants mainly lingering
between Champaign and Danville. Earlier clear slot east of I-57
was filling in as well, although clouds to the west are more
broken instead of a solid overcast.
Upper low located near La Crosse WI early this evening, with a
prominent trough swinging east across eastern Iowa and central
Missouri per water vapor imagery. This may bring a few more
showers as it passes through the state overnight, but more
widespread coverage is more likely up in Iowa. Have already
updated the zones/grids to cut back on the precipitation chances
overnight. Temperatures are generally on track and only made some
minor adjustments to reflect the latest hourly trends.
Geelhart
&&
.AVIATION...
ISSUED 610 PM CDT Tue Apr 29 2014
Line of showers with scattered thunder will continue to affect the
KDEC/KCMI areas for a couple more hours, before fading at sunset.
Main question overnight will be with how low ceilings get. Fairly
decent size area of MVFR ceilings west of the Mississippi River
with some IFR conditions in southern Iowa. Some of these will be
pushing their way eastward later tonight as a significant upper
trough swings toward us. RAP ceiling guidance suggesting most of
the TAF sites seeing about a 3 to 4 hour window where ceilings get
down into IFR range as the trough passes, although KPIA may linger
longer as it is closer to the parent upper low. Ceilings expected
to then rise through MVFR range during the morning, and should
largely be VFR by midday. Have lingered clouds below 3000 feet at
KBMI/KCMI through the end of the forecast period, as forecast
soundings hold off fully lifting the ceilings until late in the
afternoon.
Geelhart
&&
.PREV DISCUSSION...
ISSUED 302 PM CDT Tue Apr 29 2014
Short term and long term models are in very good agreement
overall and with the upper level pattern. So confidence is good
with the forecast this package. Main concerns this package include
chances of pcpn next several days as the upper level system slowly
pushes east and then northeast through the Great Lakes region.
SHORT TERM...Tonight through Friday
Models forecast the upper level system to slowly move northeast
next several days and finally lift northeast out of the area. With
forecast area remaining in cyclonic flow pattern, a forecast of
mostly cloudy skies and scattered showers still looks good for
tonight through Friday. The best chances, though still small, will
be across the northern half of the forecast area, though a slight
chance will continue for the southern half of the area. Colder air
will also advect into the area at the 850mb level, which will
create sufficient lapse rates to support scattered showers through
the period, just like what is happening now across Missouri,
Kansas, and Iowa.
Cooler temps advecting into the region, along with continued
cloudy skies will also keep temps during the day well below normal
for end of April. So for next 3 days, expect afternoon highs to
only be in the 50s.
LONG TERM...Friday night through Tuesday
As the cutoff upper level low moves away, the pattern will
transition to a northwesterly flow. There could be some minor weak
waves in this flow, but this far out, models can not pick up on
those small of details. So conditions should be dry through the
weekend. Then a ridge will begin to build in the plains with
continued dry weather and temps warming. Cool temps will continue
through the weekend, but then begin to warm back to normal for
Monday, and then above normal for Tue. The next chance of pcpn
looks to be sometime during the latter half of next week.
Auten
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
645 PM CDT TUE APR 29 2014
.DISCUSSION...
240 PM CDT
ROBUST RIDGE PARKED OVER HUDSON BAY HAS ALLOWED A LOGJAM IN THE FLOW
OF SYSTEMS...WITH THE SFC LOW ANALYZED OVER FAR NORTHWEST IL THIS
AFTERNOON. THIS LOW WILL DRIFT EAST/NORTHEAST OVERNIGHT...PROGGED TO
BE POSITIONED OVER SOUTHCENTRAL WISC ARND DAYBREAK WED.
INSTABILITY HAS BEEN STEADILY PUSHING EAST OF THE CWFA THIS
AFTN...HOWEVER SOME WEAK CONVERGENCE WAS STILL NOTED ACROSS
NORTHWEST IN. BASED ON THE VISIBLE IMAGERY INDICATING FEW CUMULUS
CLOUDS...AND SFC DEW POINTS STEADILY DIMINISHING INTO THE MID
40S...THE CONFIDENCE IN ADDTL THUNDERSTORMS DEVELOPING IS VERY LOW.
HAVE HELD ONTO THE MENTION OF ISOLATED THUNDER THRU LATE THIS AFTN.
WITH ANY CONVECTIVE DEVELOPMENT...THE MAIN CONCERNS WOULD BE BRIEF
WIND GUSTS AND HAIL TO PENNY SIZE.
DEEP LAYERED MOISTURE WILL PERSIST OVERNIGHT...WITH SOME SPOTTY
SHOWERS ROTATING NORTH ACROSS THE FORECAST AREA. TEMPS WILL BE ABLE
TO COOL INTO THE MID/UPR 40S TONIGHT.
WEDNESDAY THROUGH THURSDAY...
THE 500MB VORT WILL REMAIN ACROSS THE REGION...AS THE SFC LOW OVER
SOUTHCENTRAL WISC WEAKENS. GUIDANCE SUGGESTS ANOTHER WEAK VORT LOBE
WILL PIVOT NORTHEAST ACROSS THE REGION. SHOWER COVERAGE SHUD REMAIN
MARGINAL FOR WED...AND WOULD LIKELY SEE MORE DRY PERIODS ON WED THEN
WET. HAVE HELD ONTO THE 30-40% POPS...BUT COULD SEE THIS NEEDING TO
BE TRIMMED BACK FOR AREAS SOUTH OF I-80. BETTER CHC FOR PRECIP
APPEARS TO BE FOCUSED OVER THE NORTHERN CWFA WED.
SFC RIDGE WILL BEGIN TO DRIFT NORTHEAST OF HUDSON BAY...WHICH WILL
ALLOW THE DEEP TROUGH OVER THE GREAT LAKES TO BEGIN LIFTING
NORTHEAST. HOWEVER IT DOES SO VERY SLOWLY...AND WITH CONSIDERABLE
MOISTURE LINGERING ACROSS THE FORECAST AREA THE CHANCES FOR PRECIP
WILL CONTINUE THRU THUR. 500MB TROUGH AXIS WILL CONTINUE TO LIFT
NORTHEAST THUR NIGHT. NOT EXPECTING MANY BREAKS IN THE CLOUDS THRU
MID-WEEK...SO EXPECT TEMPS TO HOLD GENERALLY IN THE 50S.
FRIDAY THROUGH EARLY NEXT WEEK...
WHILE THE BLOCK OVER HUDSON BAY CONTINUES TO DEPART TO THE
NORTHEAST...A HIGH-AMPLITUDE RIDGE OVER ALASKA WILL LIKELY PROLONG
WEAK TROUGHING FOR THE UPPER MIDWEST/GREAT LAKES REGION INTO FRI.
FORTUNATELY OPERATIONAL GUIDANCE IS BEGINNING TO SUGGEST SOME DRYING
WILL TAKE PLACE FRI. AT THIS TIME STILL CARRYING LOW CHC POPS
FRI...BUT WITH MID-LVL HEIGHTS POISED TO BE RISING LATE IN THE DAY
FRI ENOUGH SUBSIDENCE IN THE MID-LVLS COULD PRODUCE DRY CONDS
EARLIER AND RESULT IN A DRY FRI.
ANOTHER SHORTWAVE IS PROGGED TO SLIDE SOUTHEAST FROM CENTRAL CANADA
SAT...AND BRING A BRIEF PERIOD OF SHOWERS OVER THE WEEKEND.
CONFIDENCE IN TIMING/LOCATION OF THIS IS LOW BASED ON CURRENT
GUIDANCE. THEN FOR THE SECOND HALF OF THE WEEKEND THE PERSISTENT
TROUGH OVER THE GREAT LAKES WILL BEGIN TO PUSH EAST WITH WEAK
RIDGING ARRIVING. THIS WILL LIKELY ALLOW WEAK SFC RIDGE AND DRY
CONDS FOR THE START OF NEXT WEEK.
TEMPS WILL SLOWLY RETURN TO NEAR SEASONAL CONDS IN THE 60S FOR THE
SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK...WITH THE EXCEPTION
OF AREAS ADJACENT TO LAKE MICHIGAN WHERE THE NORTHEAST/EAST WINDS
EARLY NEXT WEEK WILL KEEP TEMPS IN THE LOW/MID 50S.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* SHRA THIS EVENING.
* CHANCE OF TSRA THIS EVENING.
* IFR CIGS OVERNIGHT/WEDNESDAY MORNING. MVFR CIGS WEDNESDAY.
* POSSIBLE FOG TONIGHT.
* CHANCE OF SHRA WEDNESDAY MORNING.
* POSSIBLE GUSTY SOUTHWESTERLY WINDS WEDNESDAY AFTERNOON. CMS
//DISCUSSION...UPDATED 00Z...
A LINE OF SHOWERS WITH EMBEDDED TSRA CONTINUES TO LIFT NORTHEAST
FROM TIP TO IKK TO GYY. SHORT TERM/HIGH RES GUIDANCE CONTINUES TO
HAVE A GOOD HANDLE ON THIS ACTIVITY SHOWING THE STRONGEST CELLS
PASSING JUST EAST OF ORD AND POSSIBLY IMPACTING MDW OVER THE NEXT
HOUR OR TWO AND HAVE OPTED TO CONTINUE VCTS MENTION FOR NOW AND
WILL NEED TO MONITOR TRENDS THIS EVENING. ADDITIONAL SHOWERS
DEVELOPING ACROSS PARTS OF CENTRAL IL WILL ALSO LIFT NORTH AS WELL
AS CONTINUED SHOWERS ACROSS NORTHWEST IL. WHILE THIS ACTIVITY MAY
BE LIGHT IN MANY AREAS...HAVE CONTINUED PREVAILING SHOWER MENTION
WITH THIS FORECAST THROUGH MID EVENING WITH THE POTENTIAL FOR
ADDITIONAL SHOWERS LATE THIS EVENING INTO THE EARLY MORNING HOURS.
A BROAD AREA OF LOW PRESSURE OVER EASTERN IA WILL LIFT NORTHEAST
ACROSS NORTHERN IL AND SOUTHERN WI TONIGHT. AS IT DOES...LOWER
CIGS OVER EASTERN IA WILL SHIFT EAST. FAIRLY CONFIDENT IFR CIGS
WILL SPREAD ACROSS RFD THIS EVENING BUT HOW FAR AND HOW FAST THESE
LOWER CIGS SPREAD ACROSS NORTHEAST IL AND THE CHICAGO TERMINALS IS
SOMEWHAT UNCERTAIN. FOR NOW...HAVE MAINTAINED PREVIOUS IFR CIGS
AND TIMING BUT CHANGES ARE POSSIBLE AS TRENDS EMERGE THIS EVENING
AND OVERNIGHT. CIGS ARE THEN EXPECTED TO LIFT THROUGH MVFR
WEDNESDAY MORNING AND EVENTUALLY BECOMING VFR IN THE AFTERNOON.
WEST/SOUTHWEST WINDS ARE EXPECTED TO TURN MORE SOUTHERLY THIS
EVENING WITH SPEEDS DIMINISHING WELL UNDER 10KTS OVERNIGHT. TIMING
AND CONFIDENCE HERE IS ALSO A BIT UNCERTAIN THOUGH ANY REMAINING
GUSTS SHOULD DIMINISH QUICKLY WITH SUNSET. WINDS ARE EXPECTED TO
GO BACK SOUTHWESTERLY WEDNESDAY WITH SOME GUSTS INTO THE MID/UPPER
TEEN RANGE POSSIBLE. CMS
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM FOR SHRA THIS EVENING.
* LOW FOR TSRA THIS EVENING.
* LOW TO MEDIUM FOR CIG TRENDS OVERNIGHT/WEDNESDAY.
* LOW FOR FOG OVERNIGHT.
* LOW FOR SHRA WEDNESDAY MORNING.
* MEDIUM FOR WINDS THROUGH THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY THROUGH SUNDAY...CHANCE OF SHRA. MVFR CIGS POSSIBLE.
* MONDAY...DRY/VFR.
&&
.MARINE...
217 PM CDT
A VERY SLOW MOVING AREA OF SURFACE LOW PRESSURE CONTINUES TO FILL
ACROSS EASTERN IOWA THIS AFTERNOON...WITH A WARM FRONT EXTENDING
EAST ACROSS NORTHERN ILLINOIS AND FAR SOUTHERN LAKE MICHIGAN. THE
SURFACE PRESSURE GRADIENT ACROSS LAKE MICHIGAN WILL CONTINUE TO
WEAKEN AS THE LOW AND WARM FRONT DRIFT TO THE NORTHEAST TONIGHT...
RESULTING IN DECREASING WINDS ACROSS THE LAKE. EAST-NORTHEAST WINDS
WILL VEER TO THE SOUTH-SOUTHEAST AS THE WARM FRONT LIFTS NORTH
THROUGH WEDNESDAY...BEFORE SHIFTING WEST-SOUTHWEST THURSDAY AS THE
LOW PASSES TO THE NORTHEAST AND TRAILS A WEAK COLD FRONT ACROSS THE
LAKE. MOIST LOW LEVEL AIR OVER THE COOL LAKE WATERS WILL LEAD TO
AREAS OF FOG...WHICH MAY BE DENSE AT TIMES...UNTIL THE COLD FRONT
MOVES EAST OF THE LAKE AND DRIER WESTERLY FLOW DEVELOPS THURSDAY.
MODEST WEST WINDS WILL THEN CONTINUE INTO THE WEEKEND BEFORE A WEAK
HIGH PRESSURE RIDGE PASSES LATE SUNDAY/SUNDAY NIGHT. EAST WINDS ARE
THEN EXPECTED TO DEVELOP MONDAY AS THE RIDGE MOVES OFF TO THE EAST.
FOR THE ILLINOIS AND INDIANA NEARSHORE AREAS...VARIOUS WEB CAMS
NEAR/ALONG THE ILLINOIS SHORE SHOW VISIBILITY IMPROVING
SIGNIFICANTLY AT MID-AFTERNOON AND WILL BE CANCELLING DENSE FOG
ADVISORY SHORTLY. WILL MAINTAIN THE SMALL CRAFT ADVISORY FOR THE
INDIANA SHORE...WITH SOUTHWEST WINDS GUSTING AROUND 30 KT BEHIND
WARM FRONT CURRENTLY. WINDS SHOULD DIMINISH FAIRLY QUICKLY BY EARLY
EVENING HOWEVER WITH WEAKENING GRADIENT AND LOSS OF STEEP LOW LEVEL
LAPSE RATES OVER ADJACENT LAND.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY
IN UNTIL 7 PM 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
611 PM CDT Tue Apr 29 2014
.DISCUSSION...
ISSUED 302 PM CDT Tue Apr 29 2014
Short term and long term models are in very good agreement
overall and with the upper level pattern. So confidence is good
with the forecast this package. Main concerns this package include
chances of pcpn next several days as the upper level system slowly
pushes east and then northeast through the Great Lakes region.
SHORT TERM...Tonight through Friday
Models forecast the upper level system to slowly move northeast
next several days and finally lift northeast out of the area. With
forecast area remaining in cyclonic flow pattern, a forecast of
mostly cloudy skies and scattered showers still looks good for
tonight through Friday. The best chances, though still small, will
be across the northern half of the forecast area, though a slight
chance will continue for the southern half of the area. Colder air
will also advect into the area at the 850mb level, which will
create sufficient lapse rates to support scattered showers through
the period, just like what is happening now across Missouri,
Kansas, and Iowa.
Cooler temps advecting into the region, along with continued
cloudy skies will also keep temps during the day well below normal
for end of April. So for next 3 days, expect afternoon highs to
only be in the 50s.
LONG TERM...Friday night through Tuesday
As the cutoff upper level low moves away, the pattern will
transition to a northwesterly flow. There could be some minor weak
waves in this flow, but this far out, models can not pick up on
those small of details. So conditions should be dry through the
weekend. Then a ridge will begin to build in the plains with
continued dry weather and temps warming. Cool temps will continue
through the weekend, but then begin to warm back to normal for
Monday, and then above normal for Tue. The next chance of pcpn
looks to be sometime during the latter half of next week.
Auten
&&
.AVIATION...
ISSUED 610 PM CDT Tue Apr 29 2014
Line of showers with scattered thunder will continue to affect the
KDEC/KCMI areas for a couple more hours, before fading at sunset.
Main question overnight will be with how low ceilings get. Fairly
decent size area of MVFR ceilings west of the Mississippi River
with some IFR conditions in southern Iowa. Some of these will be
pushing their way eastward later tonight as a significant upper
trough swings toward us. RAP ceiling guidance suggesting most of
the TAF sites seeing about a 3 to 4 hour window where ceilings get
down into IFR range as the trough passes, although KPIA may linger
longer as it is closer to the parent upper low. Ceilings expected
to then rise through MVFR range during the morning, and should
largely be VFR by midday. Have lingered clouds below 3000 feet at
KBMI/KCMI through the end of the forecast period, as forecast
soundings hold off fully lifting the ceilings until late in the
afternoon.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
647 PM EDT MON APR 28 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 349 PM EDT MON APR 28 2014
A LARGE UPPER LEVEL LOW PRESSURE SYSTEM HANGING AROUND
THE MIDWEST FOR THE NEXT SEVERAL DAYS WILL KEEP UNSETTLED WEATHER IN
THE FORECAST. CHANCES FOR THUNDERSTORMS WILL REMAIN TONIGHT THROUGH
TUESDAY NIGHT WITH SOME INSTABILITY AROUND...AND CHANCES FOR RAIN
WILL CONTINUE INTO THE WEEKEND.
&&
.NEAR TERM /THIS EVENING AND TONIGHT/...
ISSUED AT 349 PM EDT MON APR 28 2014
RADAR MOSAIC AT 330 PM SHOWS A LARGE AREA OF SHOWERS WITH SOME
EMBEDDED THUNDER MOVING NORTHEAST THROUGH THE SOUTHERN PORTIONS OF
CENTRAL INDIANA STRETCHING BACK SOUTHWEST INTO SOUTHERN ILLINOIS AND
WESTERN KENTUCKY. ANOTHER LINE OF STORMS COULD BE FOUND ALONG THE
COLD FRONT/DRY LINE IN EASTERN MISSOURI HEADING INTO ILLINOIS...AND
SOME OTHER CELLS FORMING ALONG THE PORTION OF THE WARM FRONT IN IOWA
AND WESTERN TO CENTRAL ILLINOIS. VISIBLE SATELLITE SHOWS CENTRAL
INDIANA SOCKED IN WITH CLOUD COVER AS IT HAS BEEN ALL DAY. HI RES
MODELS CONTINUE TO SHOW BIG DISAGREEMENTS IN THE SHORT TERM AND
HOW/WHERE CONVECTION WILL DEVELOP FOR THE REMAINDER OF THE AFTERNOON
INTO TONIGHT MAKING THIS A FORECAST WITH HIGH UNCERTAINTY.
HRRR MOVES THE CURRENT ECHOES NORTHEAST THROUGH THE AREA OVER THE
NEXT FEW HOURS...BUT THEN SHOWS LITTLE DEVELOPMENT UNTIL THE COLD
FRONT MOVES IN LATER TONIGHT /AROUND 4Z OR SO IN THE WEST/. RAP
DEVELOPS SCATTERED CONVECTION ACROSS THE AREA AND AN ORGANIZED AREA
ALONG THE WARM FRONT STRETCHING ACROSS NORTHERN AND CENTRAL INDIANA.
18Z ILX SOUNDING SHOWED A PRETTY DECENT INVERSION AND BASED ON
ACTIVITY /OR LACK THEREOF/ ACROSS CENTRAL INDIANA INFER THAT THE
INVERSION COULD BE MORE STOUT HERE. IN ADDITION INSTABILITY HERE IS
LIMITED DUE TO THE AFOREMENTIONED CLOUD COVER. NAM12 SHOWS 500 MB
JET MAX APPROACHING OVER THE NEXT COUPLE OF HOURS THOUGH...SO SOME
STRONG FORCING POTENTIAL WITH SOME SHEAR IS STILL OUT THERE. THUS
NOT READY TO ABANDON THE SEVERE RISK YET BUT DO THINK IT COULD BE
DECREASING AT LEAST FOR CENTRAL INDIANA. TIMED THE NEXT FEW HOURS OF
POP GRIDS BASED ON THE HRRR AND RADAR LOOP.
FOR THE TONIGHT PERIOD THERE ARE SOME BIG DIFFERENCES IN
HRRR...RAP...NAM12 AND GFS AS WELL AS SREFS. FINALLY DECIDED GIVEN
THE HIGH UNCERTAINTY WOULD INCLUDE A HIGH CHANCE POP AND SCATTERED
THUNDERSTORM WORDING. DID NOT FEEL CONFIDENT ENOUGH ON
PLACEMENT/TIMING TO GET ANY MORE SPECIFIC THAN THAT UNTIL AFTER 6Z
WHEN CHANCES SHOULD START TO DECREASE FROM WEST TO EAST.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 349 PM EDT MON APR 28 2014
FORECAST FOCUS IS ON POPS THROUGHOUT AND SEVERE POTENTIAL TUESDAY.
MODELS ARE SHOWING AGREEMENT ON GENERAL PATTERN BUT DIFFERENCES ON
THE DETAILS THAT DETERMINE TIMING OF PRECIP. GENERALLY TRIED TO USE
AN AVERAGE.
FOR TUESDAY EXPECT TO SEE A LULL IN THE PRECIP ON TUESDAY MORNING AS
THE FRONT WILL BE NORTH OF THE AREA AND UPPER LOW VORT MAXES ARE NOT
IN FAVORABLE POSITIONS. BY AFTERNOON THOUGH STEEP LAPSE RATES ADVECT
IN AND SOME INSTABILITY BUILDS EVEN THOUGH SOME DRYING OF THE AIR
MASS WILL HAVE OCCURRED. A VORT MAX WILL APPROACH FROM THE SOUTHWEST
LEADING UP TO 0Z. BEST JET DYNAMICS LOOK LIKE THEY WILL SET UP EAST
OF THE AREA...BUT STILL ENOUGH IN PLACE ESPECIALLY WITH THE STEEP
LAPSE RATES THAT LARGE HAIL COULD BE A PROBLEM. STUCK WITH MAV POPS
BUT RAMPED UP TO THEM WITH THE BEST POTENTIAL STARTING AROUND 21Z.
BROUGHT LIKELY IN THE EAST AFTER 0Z WED AS VORT MAX ROTATES THROUGH
THE EASTERN COUNTIES AND ANOTHER WEAK SURFACE BOUNDARY MOVES NORTH
THROUGH THE AREA.
KEPT CHANCES FOR RAIN GOING WEDNESDAY AND THURSDAY UNDER THE
INFLUENCE OF THE UPPER LOW AND DROPPED TO A SLIGHT CHANCE IN THE
SOUTHWEST ON WEDNESDAY NIGHT WITH LESS FORCING AVAILABLE THEN. LOOKS
LIKE MOST INSTABILITY WILL BE MOVING OUT AND THE UPPER LOW WEAKENS
AS IT WOBBLES AROUND WEDNESDAY THROUGH THURSDAY SO DID NOT INCLUDE
THUNDER DURING THOSE TIMES.
FOR TEMPERATURES TUESDAY STUCK CLOSER TO THE COOLER MET NUMBERS WITH
MAV LOOKING TOO WARM GIVEN EXPECTED CLOUD COVER. OTHERWISE GENERALLY
USED CONSENSUS NUMBERS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 203 PM EDT MON APR 28 2014
A LARGE UPPER LOW OVER THE GREAT LAKES WILL LIFT NORTH INTO SOUTHERN
CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR
WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY AS
PRECIPITATION CHANCES WANE AND TEMPERATURES BEGIN TO INCREASE BACK
TOWARD NORMAL. A FEW WAVES WILL ROTATE THROUGH THE REGION THROUGH
EARLY THIS WEEKEND ALLOWING MOSTLY CLOUDY SKIES AND CHANCE FOR
SHOWERS TO PERSIST. A RETURN TO MORE CLIMO TEMPS AND DRY WEATHER
LOOKS TO BE IN STORE FOR EARLY NEXT WEEK.
&&
.AVIATION /DISCUSSION FOR 290000Z TAF ISSUANCE/...
ISSUED AT 647 PM EDT MON APR 28 2014
MVFR OR LOWER POSSIBLE IN CONVECTION...ESPECIALLY IN THE FIRST 6
HOURS OR SO OF THE TAF PERIOD. OTHERWISE GENERALLY VFR EXPECTED.
AREA OF SHOWERS AND SCATTERED THUNDERSTORMS WILL MOVE INTO THE AREA
FROM THE SOUTHWEST EARLY IN THE PERIOD. LATEST OBSERVATIONS NOT
SHOWING A LOT OF MVFR CONDITIONS WITH THESE. THUS WILL GO WITH VFR
CONDITIONS IN THIS AREA WITH VCTS MENTION. OF COURSE IN ANY HEAVIER
CONVECTION MVFR OR LOWER IS POSSIBLE BRIEFLY.
WATCHING LINE OF TSRA ACROSS ILLINOIS THAT IS MOVING TOWARD THE
AREA. MAY HAVE TO ADD TEMPO GROUPS FOR THIS LINE LATER THIS EVENING
IF IT HOLDS TOGETHER. AGAIN MVFR OR WORSE POSSIBLE WITH THIS LINE.
OVERNIGHT SCATTERED SHOWERS ARE STILL POSSIBLE SO WILL KEEP VCSH.
ON TUESDAY ADDITIONAL CONVECTION MAY DEVELOP IN AFTERNOON BUT NOT
SURE ON LOCATION/COVERAGE SO LEFT OUT OF TAFS. WINDS WILL GUST OVER
20KT TUESDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....SMF
AVIATION...50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
422 PM EDT MON APR 28 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 349 PM EDT MON APR 28 2014
A LARGE UPPER LEVEL LOW PRESSURE SYSTEM HANGING AROUND
THE MIDWEST FOR THE NEXT SEVERAL DAYS WILL KEEP UNSETTLED WEATHER IN
THE FORECAST. CHANCES FOR THUNDERSTORMS WILL REMAIN TONIGHT THROUGH
TUESDAY NIGHT WITH SOME INSTABILITY AROUND...AND CHANCES FOR RAIN
WILL CONTINUE INTO THE WEEKEND.
&&
.NEAR TERM /THIS EVENING AND TONIGHT/...
ISSUED AT 349 PM EDT MON APR 28 2014
RADAR MOSAIC AT 330 PM SHOWS A LARGE AREA OF SHOWERS WITH SOME
EMBEDDED THUNDER MOVING NORTHEAST THROUGH THE SOUTHERN PORTIONS OF
CENTRAL INDIANA STRETCHING BACK SOUTHWEST INTO SOUTHERN ILLINOIS AND
WESTERN KENTUCKY. ANOTHER LINE OF STORMS COULD BE FOUND ALONG THE
COLD FRONT/DRY LINE IN EASTERN MISSOURI HEADING INTO ILLINOIS...AND
SOME OTHER CELLS FORMING ALONG THE PORTION OF THE WARM FRONT IN IOWA
AND WESTERN TO CENTRAL ILLINOIS. VISIBLE SATELLITE SHOWS CENTRAL
INDIANA SOCKED IN WITH CLOUD COVER AS IT HAS BEEN ALL DAY. HI RES
MODELS CONTINUE TO SHOW BIG DISAGREEMENTS IN THE SHORT TERM AND
HOW/WHERE CONVECTION WILL DEVELOP FOR THE REMAINDER OF THE AFTERNOON
INTO TONIGHT MAKING THIS A FORECAST WITH HIGH UNCERTAINTY.
HRRR MOVES THE CURRENT ECHOES NORTHEAST THROUGH THE AREA OVER THE
NEXT FEW HOURS...BUT THEN SHOWS LITTLE DEVELOPMENT UNTIL THE COLD
FRONT MOVES IN LATER TONIGHT /AROUND 4Z OR SO IN THE WEST/. RAP
DEVELOPS SCATTERED CONVECTION ACROSS THE AREA AND AN ORGANIZED AREA
ALONG THE WARM FRONT STRETCHING ACROSS NORTHERN AND CENTRAL INDIANA.
18Z ILX SOUNDING SHOWED A PRETTY DECENT INVERSION AND BASED ON
ACTIVITY /OR LACK THEREOF/ ACROSS CENTRAL INDIANA INFER THAT THE
INVERSION COULD BE MORE STOUT HERE. IN ADDITION INSTABILITY HERE IS
LIMITED DUE TO THE AFOREMENTIONED CLOUD COVER. NAM12 SHOWS 500 MB
JET MAX APPROACHING OVER THE NEXT COUPLE OF HOURS THOUGH...SO SOME
STRONG FORCING POTENTIAL WITH SOME SHEAR IS STILL OUT THERE. THUS
NOT READY TO ABANDON THE SEVERE RISK YET BUT DO THINK IT COULD BE
DECREASING AT LEAST FOR CENTRAL INDIANA. TIMED THE NEXT FEW HOURS OF
POP GRIDS BASED ON THE HRRR AND RADAR LOOP.
FOR THE TONIGHT PERIOD THERE ARE SOME BIG DIFFERENCES IN
HRRR...RAP...NAM12 AND GFS AS WELL AS SREFS. FINALLY DECIDED GIVEN
THE HIGH UNCERTAINTY WOULD INCLUDE A HIGH CHANCE POP AND SCATTERED
THUNDERSTORM WORDING. DID NOT FEEL CONFIDENT ENOUGH ON
PLACEMENT/TIMING TO GET ANY MORE SPECIFIC THAN THAT UNTIL AFTER 6Z
WHEN CHANCES SHOULD START TO DECREASE FROM WEST TO EAST.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 349 PM EDT MON APR 28 2014
FORECAST FOCUS IS ON POPS THROUGHOUT AND SEVERE POTENTIAL TUESDAY.
MODELS ARE SHOWING AGREEMENT ON GENERAL PATTERN BUT DIFFERENCES ON
THE DETAILS THAT DETERMINE TIMING OF PRECIP. GENERALLY TRIED TO USE
AN AVERAGE.
FOR TUESDAY EXPECT TO SEE A LULL IN THE PRECIP ON TUESDAY MORNING AS
THE FRONT WILL BE NORTH OF THE AREA AND UPPER LOW VORT MAXES ARE NOT
IN FAVORABLE POSITIONS. BY AFTERNOON THOUGH STEEP LAPSE RATES ADVECT
IN AND SOME INSTABILITY BUILDS EVEN THOUGH SOME DRYING OF THE AIR
MASS WILL HAVE OCCURRED. A VORT MAX WILL APPROACH FROM THE SOUTHWEST
LEADING UP TO 0Z. BEST JET DYNAMICS LOOK LIKE THEY WILL SET UP EAST
OF THE AREA...BUT STILL ENOUGH IN PLACE ESPECIALLY WITH THE STEEP
LAPSE RATES THAT LARGE HAIL COULD BE A PROBLEM. STUCK WITH MAV POPS
BUT RAMPED UP TO THEM WITH THE BEST POTENTIAL STARTING AROUND 21Z.
BROUGHT LIKELY IN THE EAST AFTER 0Z WED AS VORT MAX ROTATES THROUGH
THE EASTERN COUNTIES AND ANOTHER WEAK SURFACE BOUNDARY MOVES NORTH
THROUGH THE AREA.
KEPT CHANCES FOR RAIN GOING WEDNESDAY AND THURSDAY UNDER THE
INFLUENCE OF THE UPPER LOW AND DROPPED TO A SLIGHT CHANCE IN THE
SOUTHWEST ON WEDNESDAY NIGHT WITH LESS FORCING AVAILABLE THEN. LOOKS
LIKE MOST INSTABILITY WILL BE MOVING OUT AND THE UPPER LOW WEAKENS
AS IT WOBBLES AROUND WEDNESDAY THROUGH THURSDAY SO DID NOT INCLUDE
THUNDER DURING THOSE TIMES.
FOR TEMPERATURES TUESDAY STUCK CLOSER TO THE COOLER MET NUMBERS WITH
MAV LOOKING TOO WARM GIVEN EXPECTED CLOUD COVER. OTHERWISE GENERALLY
USED CONSENSUS NUMBERS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 203 PM EDT MON APR 28 2014
A LARGE UPPER LOW OVER THE GREAT LAKES WILL LIFT NORTH INTO SOUTHERN
CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR
WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY AS
PRECIPITATION CHANCES WANE AND TEMPERATURES BEGIN TO INCREASE BACK
TOWARD NORMAL. A FEW WAVES WILL ROTATE THROUGH THE REGION THROUGH
EARLY THIS WEEKEND ALLOWING MOSTLY CLOUDY SKIES AND CHANCE FOR
SHOWERS TO PERSIST. A RETURN TO MORE CLIMO TEMPS AND DRY WEATHER
LOOKS TO BE IN STORE FOR EARLY NEXT WEEK.
&&
.AVIATION /DISCUSSION FOR 282100Z TAF UPDATE/...
ISSUED AT 422 PM EDT MON APR 28 2014
AREA OF SHOWERS AND ISOLATED THUNDERSTORMS SHOULD STAY SOUTH AND
EAST OF KIND FOR NOW /OTHER THAN PERHAPS SOME SPRINKLES AT THE
MOMENT/ SO REMOVED MENTION. BEFORE ADDITIONAL SHOWERS/STORMS MOVE IN
AFTER 00Z LOOKS LIKE VFR CONDITIONS WILL PREVAIL WITH GUSTY WINDS.
PREVIOUS DISCUSSION FOLLOWS...
GUIDANCE IS INDICATING THERE WILL BE ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. TIMING VARIES
AMONG THE MODELS SO THE AVIATION FORECAST IS VERY DIFFICULT TO PIN
DOWN AT THIS TIME. BASED ON HRRR...ADDED -SHRA AND VCTS WITH CB
GROUPS TO MANY OF THE TAF SITES AS THIS SHORT RANGE MODEL
INDICATES THE NEXT ROUND FOR SHOWERS WILL BEGIN IMPACTING CENTRAL
INDIANA. THEN AS A WARM FRONT LIFTS NORTH OVER THE REGION THIS
EVENING AND WE ARE FIRMLY PLACED IN THE WARM SECTOR EXPECT
SCATTERED SHRA/TSRA TO CONTINUE OVERNIGHT. COULD BE ANOTHER
PERIOD OF MVFR CEILINGS TONIGHT WHICH WAS INDICATED IN THE TAFS. A
LULL IN ACTIVITY MAY BE IN STORE FOR EARLY TOMORROW BEFORE A COLD
FRONT MOVES THROUGH TUESDAY AFTERNOON.
EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE
TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....SMF
AVIATION...SMF/50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
351 PM EDT MON APR 28 2014
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 349 PM EDT MON APR 28 2014
A LARGE UPPER LEVEL LOW PRESSURE SYSTEM HANGING AROUND
THE MIDWEST FOR THE NEXT SEVERAL DAYS WILL KEEP UNSETTLED WEATHER IN
THE FORECAST. CHANCES FOR THUNDERSTORMS WILL REMAIN TONIGHT THROUGH
TUESDAY NIGHT WITH SOME INSTABILITY AROUND...AND CHANCES FOR RAIN
WILL CONTINUE INTO THE WEEKEND.
&&
.NEAR TERM /THIS EVENING AND TONIGHT/...
ISSUED AT 349 PM EDT MON APR 28 2014
RADAR MOSAIC AT 330 PM SHOWS A LARGE AREA OF SHOWERS WITH SOME
EMBEDDED THUNDER MOVING NORTHEAST THROUGH THE SOUTHERN PORTIONS OF
CENTRAL INDIANA STRETCHING BACK SOUTHWEST INTO SOUTHERN ILLINOIS AND
WESTERN KENTUCKY. ANOTHER LINE OF STORMS COULD BE FOUND ALONG THE
COLD FRONT/DRY LINE IN EASTERN MISSOURI HEADING INTO ILLINOIS...AND
SOME OTHER CELLS FORMING ALONG THE PORTION OF THE WARM FRONT IN IOWA
AND WESTERN TO CENTRAL ILLINOIS. VISIBLE SATELLITE SHOWS CENTRAL
INDIANA SOCKED IN WITH CLOUD COVER AS IT HAS BEEN ALL DAY. HI RES
MODELS CONTINUE TO SHOW BIG DISAGREEMENTS IN THE SHORT TERM AND
HOW/WHERE CONVECTION WILL DEVELOP FOR THE REMAINDER OF THE AFTERNOON
INTO TONIGHT MAKING THIS A FORECAST WITH HIGH UNCERTAINTY.
HRRR MOVES THE CURRENT ECHOES NORTHEAST THROUGH THE AREA OVER THE
NEXT FEW HOURS...BUT THEN SHOWS LITTLE DEVELOPMENT UNTIL THE COLD
FRONT MOVES IN LATER TONIGHT /AROUND 4Z OR SO IN THE WEST/. RAP
DEVELOPS SCATTERED CONVECTION ACROSS THE AREA AND AN ORGANIZED AREA
ALONG THE WARM FRONT STRETCHING ACROSS NORTHERN AND CENTRAL INDIANA.
18Z ILX SOUNDING SHOWED A PRETTY DECENT INVERSION AND BASED ON
ACTIVITY /OR LACK THEREOF/ ACROSS CENTRAL INDIANA INFER THAT THE
INVERSION COULD BE MORE STOUT HERE. IN ADDITION INSTABILITY HERE IS
LIMITED DUE TO THE AFOREMENTIONED CLOUD COVER. NAM12 SHOWS 500 MB
JET MAX APPROACHING OVER THE NEXT COUPLE OF HOURS THOUGH...SO SOME
STRONG FORCING POTENTIAL WITH SOME SHEAR IS STILL OUT THERE. THUS
NOT READY TO ABANDON THE SEVERE RISK YET BUT DO THINK IT COULD BE
DECREASING AT LEAST FOR CENTRAL INDIANA. TIMED THE NEXT FEW HOURS OF
POP GRIDS BASED ON THE HRRR AND RADAR LOOP.
FOR THE TONIGHT PERIOD THERE ARE SOME BIG DIFFERENCES IN
HRRR...RAP...NAM12 AND GFS AS WELL AS SREFS. FINALLY DECIDED GIVEN
THE HIGH UNCERTAINTY WOULD INCLUDE A HIGH CHANCE POP AND SCATTERED
THUNDERSTORM WORDING. DID NOT FEEL CONFIDENT ENOUGH ON
PLACEMENT/TIMING TO GET ANY MORE SPECIFIC THAN THAT UNTIL AFTER 6Z
WHEN CHANCES SHOULD START TO DECREASE FROM WEST TO EAST.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 349 PM EDT MON APR 28 2014
FORECAST FOCUS IS ON POPS THROUGHOUT AND SEVERE POTENTIAL TUESDAY.
MODELS ARE SHOWING AGREEMENT ON GENERAL PATTERN BUT DIFFERENCES ON
THE DETAILS THAT DETERMINE TIMING OF PRECIP. GENERALLY TRIED TO USE
AN AVERAGE.
FOR TUESDAY EXPECT TO SEE A LULL IN THE PRECIP ON TUESDAY MORNING AS
THE FRONT WILL BE NORTH OF THE AREA AND UPPER LOW VORT MAXES ARE NOT
IN FAVORABLE POSITIONS. BY AFTERNOON THOUGH STEEP LAPSE RATES ADVECT
IN AND SOME INSTABILITY BUILDS EVEN THOUGH SOME DRYING OF THE AIR
MASS WILL HAVE OCCURRED. A VORT MAX WILL APPROACH FROM THE SOUTHWEST
LEADING UP TO 0Z. BEST JET DYNAMICS LOOK LIKE THEY WILL SET UP EAST
OF THE AREA...BUT STILL ENOUGH IN PLACE ESPECIALLY WITH THE STEEP
LAPSE RATES THAT LARGE HAIL COULD BE A PROBLEM. STUCK WITH MAV POPS
BUT RAMPED UP TO THEM WITH THE BEST POTENTIAL STARTING AROUND 21Z.
BROUGHT LIKELY IN THE EAST AFTER 0Z WED AS VORT MAX ROTATES THROUGH
THE EASTERN COUNTIES AND ANOTHER WEAK SURFACE BOUNDARY MOVES NORTH
THROUGH THE AREA.
KEPT CHANCES FOR RAIN GOING WEDNESDAY AND THURSDAY UNDER THE
INFLUENCE OF THE UPPER LOW AND DROPPED TO A SLIGHT CHANCE IN THE
SOUTHWEST ON WEDNESDAY NIGHT WITH LESS FORCING AVAILABLE THEN. LOOKS
LIKE MOST INSTABILITY WILL BE MOVING OUT AND THE UPPER LOW WEAKENS
AS IT WOBBLES AROUND WEDNESDAY THROUGH THURSDAY SO DID NOT INCLUDE
THUNDER DURING THOSE TIMES.
FOR TEMPERATURES TUESDAY STUCK CLOSER TO THE COOLER MET NUMBERS WITH
MAV LOOKING TOO WARM GIVEN EXPECTED CLOUD COVER. OTHERWISE GENERALLY
USED CONSENSUS NUMBERS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 203 PM EDT MON APR 28 2014
A LARGE UPPER LOW OVER THE GREAT LAKES WILL LIFT NORTH INTO SOUTHERN
CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR
WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY AS
PRECIPITATION CHANCES WANE AND TEMPERATURES BEGIN TO INCREASE BACK
TOWARD NORMAL. A FEW WAVES WILL ROTATE THROUGH THE REGION THROUGH
EARLY THIS WEEKEND ALLOWING MOSTLY CLOUDY SKIES AND CHANCE FOR
SHOWERS TO PERSIST. A RETURN TO MORE CLIMO TEMPS AND DRY WEATHER
LOOKS TO BE IN STORE FOR EARLY NEXT WEEK.
&&
.AVIATION /DISCUSSION FOR 281800Z TAF ISSUANCE/...
ISSUED AT 115 PM EDT MON APR 28 2014
GUIDANCE IS INDICATING THERE WILL BE ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. TIMING VARIES
AMONG THE MODELS SO THE AVIATION FORECAST IS VERY DIFFICULT TO PIN
DOWN AT THIS TIME. BASED ON HRRR...ADDED -SHRA AND VCTS WITH CB
GROUPS TO MANY OF THE TAF SITES AS THIS SHORT RANGE MODEL
INDICATES THE NEXT ROUND FOR SHOWERS WILL BEGIN IMPACTING CENTRAL
INDIANA. THEN AS A WARM FRONT LIFTS NORTH OVER THE REGION THIS
EVENING AND WE ARE FIRMLY PLACED IN THE WARM SECTOR EXPECT
SCATTERED SHRA/TSRA TO CONTINUE OVERNIGHT. COULD BE ANOTHER
PERIOD OF MVFR CEILINGS TONIGHT WHICH WAS INDICATED IN THE TAFS. A
LULL IN ACTIVITY MAY BE IN STORE FOR EARLY TOMORROW BEFORE A COLD
FRONT MOVES THROUGH TUESDAY AFTERNOON.
EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE
TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....SMF
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
204 PM EDT MON APR 28 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 304 AM EDT MON APR 28 2014
A LARGE AND SLOW MOVING LOW PRESSURE SYSTEM IS EXPECTED TO GRADUALLY
MOVE FROM THE PLAINS INTO THE GREAT LAKES REGION BY LATE THIS WEEK.
THIS LOW WILL KEEP THE WEATHER UNSETTLED FOR MOST OF THIS UPCOMING
WEEK.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 950 AM EDT MON APR 28 2014
RADAR MOSAIC AT 930 AM SHOWS LARGE AREA OF RAIN OVER THE NORTHEAST
HALF OR SO OF THE AREA MOVING OFF TO THE NORTHEAST WITH MORE RAIN
OVER SOUTHERN ILLINOIS/WESTERN KENTUCKY MOVING NORTHEAST AS WELL
TOWARD SOUTHERN INDIANA. VISIBLE SATELLITE SHOWS A CLEAR SLOT OVER
CENTRAL ILLINOIS...BUT A LOOP OF THIS FEATURE SHOWS IT ROTATING
MAINLY TO THE NORTH AND THUS COULD STAY OVER ILLINOIS AND MOVE INTO
NORTHERN INDIANA BUT KEEP CENTRAL INDIANA IN MOSTLY TO COMPLETELY
CLOUDY SKIES FOR THE DAY. FOR THE UPDATE ADDED SOME TIMING FOR POPS
FOR THE REST OF THE MORNING/EARLY AFTERNOON WITH A BREAK IN PRECIP
MOVING IN FROM THE EAST AND LASTING FOR THE NEXT FEW HOURS. KEPT
HIGH CHANCE TO LIKELY POPS GOING IN THE SOUTH FOR THE AFOREMENTIONED
ECHOES MOVING NORTHEAST FROM S IL/W KY. HI RES MODELS ARE SHOWING
DIFFERENT SCENARIOS FOR THE AFTERNOON/EARLY EVENING AND THIS IS
CONTRIBUTING TO HIGH UNCERTAINTY FOR THAT PERIOD. HRRR SHOWS ALL
DEVELOPMENT OCCURRING TO THE NORTH OF THE AREA WITH NOTHING FURTHER
UNTIL THE COLD FRONT ARRIVES LATER TONIGHT. RAP CONTINUES TO DEVELOP
SCATTERED CONVECTION THIS AFTERNOON. HESITANT TO BUY INTO HRRR HOOK
LINE AND SINKER WITH SUCH A DYNAMIC SYSTEM SO WENT WITH LOW CHANCE
POPS ACROSS THE AREA LATE MORNING/EARLY AFTERNOON INCREASING TO
LIKELY ACROSS THE AREA AFTER 20Z. AGAIN WITH MODEL VARIABILITY...NOT
READY TO CHANGE SEVERE OUTLOOK OR TIMING FROM PREVIOUS FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
ADDITIONAL DEVELOPMENT LATER TODAY A LITTLE MORE QUESTIONABLE...AS
SOME OF THE MODEL DATA SUGGEST MORE SHOWER/THUNDERSTORMS DEVELOPMENT
THIS AFTERNOON ALONG THE EDGE OF THE APPROACHING DRY SLOT/STEEPER
LAPSE RATES...WHILE OTHERS SUGGEST DEVELOPMENT MAY HOLD OFF UNTIL
TOWARDS/AFTER 290000Z WHEN SURFACE COLD FRONT/OCCLUSION MOVES
THROUGH. AT THIS POINT...WILL KEEP RATHER HIGH POPS GOING THROUGH
ABOUT MIDNIGHT TONIGHT...WITH THE HIGHEST POPS THROUGH ABOUT MIDDAY
TODAY.
SEVERE POTENTIAL TODAY AND TONIGHT A LITTLE LESS CLEAR. MODEL DATA
STILL SUGGEST ADEQUATE DEEP SHEAR/LAPSE RATES BY LATER THIS
AFTERNOON AND TONIGHT FOR SEVERE...ALTHOUGH THE DEEP SHEAR LOOKS A
LITTLE WEAKER TODAY THAN IT DID YESTERDAY. ALSO...LARGE AMOUNTS OF
CONVECTION DEVELOPING SOUTH OF THE OHIO RIVER IS GETTING CLOSE TO
CUTTING OFF THE FLOW OF DEEPER MOISTURE/MORE UNSTABLE AIR INTO THE
AREA. APPEARS THE BEST CHANCE FOR SEVERE WILL BE FROM THE MID
AFTERNOON HOURS UNTIL ABOUT MIDNIGHT TONIGHT...EMANATING EITHER FROM
DEVELOPMENT ALONG THE EDGE OF DRY SLOT LATER THIS AFTERNOON OR WITH
ACTIVITY TONIGHT NEAR THE SURFACE FRONT.
TODAY/S GFS MOS SEEMS TO MAY LOST ITS WARM BIAS OF THE PAST COUPLE
OF DAYS...AND THE NUMBERS FOR TODAY AND TONIGHT LOOK MORE REASONABLE.
ONLY MINOR ADJUSTMENTS PLANNED.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 304 AM EDT MON APR 28 2014
MODEL DATA SUGGEST A LARGE UPPER LOW WILL GRADUALLY SHIFT NORTHEAST
FROM THE PLAINS INTO THE MIDWEST DURING THIS PERIOD...KEEPING THE
WEATHER UNSETTLED.
BY TUESDAY...MODEL DATA SUGGEST DRIER AIR WRAPPING AROUND THE UPPER
LOW WILL MOVE INTO THE AREA. LAPSE RATES ARE QUITE STEEP ON
TUESDAY...HOWEVER BETTER SHEAR PUSHES OFF TO THE EAST WITH TIME.
WILL GO WITH CHANCE POPS FOR SHOWERS/THUNDERSTORMS ON TUESDAY AND
TUESDAY NIGHT AS A SURFACE TROUGH MOVES THROUGH...WHICH MAY SERVE AS
FOCUS FOR CONVECTION. THE PRESENCE OF THE STEEP LAPSE RATES ON
TUESDAY SUGGEST HAIL POTENTIAL WITH ANY STRONGER CELLS THAT MAY
DEVELOP.
WILL KEEP SOME CHANCE POPS GOING INTO WEDNESDAY AND WEDNESDAY NIGHT
AS FILLING UPPER LOW MOVES INTO THE GREAT LAKES.
BASED OFF ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS HIGHS FOR
TUESDAY AND WEDNESDAY LOOK A LITTLE WARM. WILL CUT A FEW DEGREES OFF
THE GUIDANCE HIGHS ON BOTH DAYS. LOWS LOOK REASONABLE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 203 PM EDT MON APR 28 2014
A LARGE UPPER LOW OVER THE GREAT LAKES WILL LIFT NORTH INTO SOUTHERN
CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR
WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY AS
PRECIPITATION CHANCES WANE AND TEMPERATURES BEGIN TO INCREASE BACK
TOWARD NORMAL. A FEW WAVES WILL ROTATE THROUGH THE REGION THROUGH
EARLY THIS WEEKEND ALLOWING MOSTLY CLOUDY SKIES AND CHANCE FOR
SHOWERS TO PERSIST. A RETURN TO MORE CLIMO TEMPS AND DRY WEATHER
LOOKS TO BE IN STORE FOR EARLY NEXT WEEK.
&&
.AVIATION /DISCUSSION FOR 281800Z TAF ISSUANCE/...
ISSUED AT 115 PM EDT MON APR 28 2014
GUIDANCE IS INDICATING THERE WILL BE ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. TIMING VARIES
AMONG THE MODELS SO THE AVIATION FORECAST IS VERY DIFFICULT TO PIN
DOWN AT THIS TIME. BASED ON HRRR...ADDED -SHRA AND VCTS WITH CB
GROUPS TO MANY OF THE TAF SITES AS THIS SHORT RANGE MODEL
INDICATES THE NEXT ROUND FOR SHOWERS WILL BEGIN IMPACTING CENTRAL
INDIANA. THEN AS A WARM FRONT LIFTS NORTH OVER THE REGION THIS
EVENING AND WE ARE FIRMLY PLACED IN THE WARM SECTOR EXPECT
SCATTERED SHRA/TSRA TO CONTINUE OVERNIGHT. COULD BE ANOTHER
PERIOD OF MVFR CEILINGS TONIGHT WHICH WAS INDICATED IN THE TAFS. A
LULL IN ACTIVITY MAY BE IN STORE FOR EARLY TOMORROW BEFORE A COLD
FRONT MOVES THROUGH TUESDAY AFTERNOON.
EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE
TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/CP
SHORT TERM...JAS
LONG TERM....SMF
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
123 PM EDT MON APR 28 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 304 AM EDT MON APR 28 2014
A LARGE AND SLOW MOVING LOW PRESSURE SYSTEM IS EXPECTED TO GRADUALLY
MOVE FROM THE PLAINS INTO THE GREAT LAKES REGION BY LATE THIS WEEK.
THIS LOW WILL KEEP THE WEATHER UNSETTLED FOR MOST OF THIS UPCOMING
WEEK.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 950 AM EDT MON APR 28 2014
RADAR MOSAIC AT 930 AM SHOWS LARGE AREA OF RAIN OVER THE NORTHEAST
HALF OR SO OF THE AREA MOVING OFF TO THE NORTHEAST WITH MORE RAIN
OVER SOUTHERN ILLINOIS/WESTERN KENTUCKY MOVING NORTHEAST AS WELL
TOWARD SOUTHERN INDIANA. VISIBLE SATELLITE SHOWS A CLEAR SLOT OVER
CENTRAL ILLINOIS...BUT A LOOP OF THIS FEATURE SHOWS IT ROTATING
MAINLY TO THE NORTH AND THUS COULD STAY OVER ILLINOIS AND MOVE INTO
NORTHERN INDIANA BUT KEEP CENTRAL INDIANA IN MOSTLY TO COMPLETELY
CLOUDY SKIES FOR THE DAY. FOR THE UPDATE ADDED SOME TIMING FOR POPS
FOR THE REST OF THE MORNING/EARLY AFTERNOON WITH A BREAK IN PRECIP
MOVING IN FROM THE EAST AND LASTING FOR THE NEXT FEW HOURS. KEPT
HIGH CHANCE TO LIKELY POPS GOING IN THE SOUTH FOR THE AFOREMENTIONED
ECHOES MOVING NORTHEAST FROM S IL/W KY. HI RES MODELS ARE SHOWING
DIFFERENT SCENARIOS FOR THE AFTERNOON/EARLY EVENING AND THIS IS
CONTRIBUTING TO HIGH UNCERTAINTY FOR THAT PERIOD. HRRR SHOWS ALL
DEVELOPMENT OCCURRING TO THE NORTH OF THE AREA WITH NOTHING FURTHER
UNTIL THE COLD FRONT ARRIVES LATER TONIGHT. RAP CONTINUES TO DEVELOP
SCATTERED CONVECTION THIS AFTERNOON. HESITANT TO BUY INTO HRRR HOOK
LINE AND SINKER WITH SUCH A DYNAMIC SYSTEM SO WENT WITH LOW CHANCE
POPS ACROSS THE AREA LATE MORNING/EARLY AFTERNOON INCREASING TO
LIKELY ACROSS THE AREA AFTER 20Z. AGAIN WITH MODEL VARIABILITY...NOT
READY TO CHANGE SEVERE OUTLOOK OR TIMING FROM PREVIOUS FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
ADDITIONAL DEVELOPMENT LATER TODAY A LITTLE MORE QUESTIONABLE...AS
SOME OF THE MODEL DATA SUGGEST MORE SHOWER/THUNDERSTORMS DEVELOPMENT
THIS AFTERNOON ALONG THE EDGE OF THE APPROACHING DRY SLOT/STEEPER
LAPSE RATES...WHILE OTHERS SUGGEST DEVELOPMENT MAY HOLD OFF UNTIL
TOWARDS/AFTER 290000Z WHEN SURFACE COLD FRONT/OCCLUSION MOVES
THROUGH. AT THIS POINT...WILL KEEP RATHER HIGH POPS GOING THROUGH
ABOUT MIDNIGHT TONIGHT...WITH THE HIGHEST POPS THROUGH ABOUT MIDDAY
TODAY.
SEVERE POTENTIAL TODAY AND TONIGHT A LITTLE LESS CLEAR. MODEL DATA
STILL SUGGEST ADEQUATE DEEP SHEAR/LAPSE RATES BY LATER THIS
AFTERNOON AND TONIGHT FOR SEVERE...ALTHOUGH THE DEEP SHEAR LOOKS A
LITTLE WEAKER TODAY THAN IT DID YESTERDAY. ALSO...LARGE AMOUNTS OF
CONVECTION DEVELOPING SOUTH OF THE OHIO RIVER IS GETTING CLOSE TO
CUTTING OFF THE FLOW OF DEEPER MOISTURE/MORE UNSTABLE AIR INTO THE
AREA. APPEARS THE BEST CHANCE FOR SEVERE WILL BE FROM THE MID
AFTERNOON HOURS UNTIL ABOUT MIDNIGHT TONIGHT...EMANATING EITHER FROM
DEVELOPMENT ALONG THE EDGE OF DRY SLOT LATER THIS AFTERNOON OR WITH
ACTIVITY TONIGHT NEAR THE SURFACE FRONT.
TODAY/S GFS MOS SEEMS TO MAY LOST ITS WARM BIAS OF THE PAST COUPLE
OF DAYS...AND THE NUMBERS FOR TODAY AND TONIGHT LOOK MORE REASONABLE.
ONLY MINOR ADJUSTMENTS PLANNED.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 304 AM EDT MON APR 28 2014
MODEL DATA SUGGEST A LARGE UPPER LOW WILL GRADUALLY SHIFT NORTHEAST
FROM THE PLAINS INTO THE MIDWEST DURING THIS PERIOD...KEEPING THE
WEATHER UNSETTLED.
BY TUESDAY...MODEL DATA SUGGEST DRIER AIR WRAPPING AROUND THE UPPER
LOW WILL MOVE INTO THE AREA. LAPSE RATES ARE QUITE STEEP ON
TUESDAY...HOWEVER BETTER SHEAR PUSHES OFF TO THE EAST WITH TIME.
WILL GO WITH CHANCE POPS FOR SHOWERS/THUNDERSTORMS ON TUESDAY AND
TUESDAY NIGHT AS A SURFACE TROUGH MOVES THROUGH...WHICH MAY SERVE AS
FOCUS FOR CONVECTION. THE PRESENCE OF THE STEEP LAPSE RATES ON
TUESDAY SUGGEST HAIL POTENTIAL WITH ANY STRONGER CELLS THAT MAY
DEVELOP.
WILL KEEP SOME CHANCE POPS GOING INTO WEDNESDAY AND WEDNESDAY NIGHT
AS FILLING UPPER LOW MOVES INTO THE GREAT LAKES.
BASED OFF ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS HIGHS FOR
TUESDAY AND WEDNESDAY LOOK A LITTLE WARM. WILL CUT A FEW DEGREES OFF
THE GUIDANCE HIGHS ON BOTH DAYS. LOWS LOOK REASONABLE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 338 AM EDT MON APR 28 2014
A LARGE UPPER LOW OVER THE GREAT LAKES THURSDAY WILL LIFT NORTH INTO
SOUTHERN CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR
WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY.
A CYCLONIC UPPER FLOW FROM THIS UPPER LOW WILL KEEP MOSTLY CLOUDY
SKIES AND CHANCES OF SHOWERS THURSDAY INTO SATURDAY. A WEAK COLD
FRONT WILL MOVE ACROSS OUR REGION EARLY SATURDAY FOLLOWED BY A HIGH
PRESSURE RIDGE SATURDAY NIGHT. SEVERAL MODELS INDICATE ANOTHER
CHANCE OF PRECIPITATION MAY BEGIN SUNDAY AS ANOTHER SYSTEM
APPROACHES.
ADDED ISOLATED THUNDER TO SUNDAY AS MODELS INDICATE MU CAPES OF UP
TO 500 J/KG. OTHERWISE...ANY PRECIPITATION WILL BE ONLY BE
SCATTERED LIGHT SHOWERS OR SPRINKLES.
TEMPERATURES WILL REMAIN QUITE COOL THURSDAY THROUGH SATURDAY AND
THEN MODERATE A LITTLE SUNDAY. ONLY MADE MINOR TWEAKS TO ALL BLEND
TEMPERATURES MAINLY TO RAISE MINS SLIGHTLY THURSDAY AND FRIDAY NIGHT
AS THERE WILL BE LOTS OF CLOUDS.
&&
.AVIATION /DISCUSSION FOR 281800Z TAF ISSUANCE/...
ISSUED AT 115 PM EDT MON APR 28 2014
GUIDANCE IS INDICATING THERE WILL BE ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. TIMING VARIES
AMONG THE MODELS SO THE AVIATION FORECAST IS VERY DIFFICULT TO PIN
DOWN AT THIS TIME. BASED ON HRRR...ADDED -SHRA AND VCTS WITH CB
GROUPS TO MANY OF THE TAF SITES AS THIS SHORT RANGE MODEL
INDICATES THE NEXT ROUND FOR SHOWERS WILL BEGIN IMPACTING CENTRAL
INDIANA. THEN AS A WARM FRONT LIFTS NORTH OVER THE REGION THIS
EVENING AND WE ARE FIRMLY PLACED IN THE WARM SECTOR EXPECT
SCATTERED SHRA/TSRA TO CONTINUE OVERNIGHT. COULD BE ANOTHER
PERIOD OF MVFR CEILINGS TONIGHT WHICH WAS INDICATED IN THE TAFS. A
LULL IN ACTIVITY MAY BE IN STORE FOR EARLY TOMORROW BEFORE A COLD
FRONT MOVES THROUGH TUESDAY AFTERNOON.
EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE
TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/CP
SHORT TERM...JAS
LONG TERM....JH
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1035 AM EDT MON APR 28 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 304 AM EDT MON APR 28 2014
A LARGE AND SLOW MOVING LOW PRESSURE SYSTEM IS EXPECTED TO GRADUALLY
MOVE FROM THE PLAINS INTO THE GREAT LAKES REGION BY LATE THIS WEEK.
THIS LOW WILL KEEP THE WEATHER UNSETTLED FOR MOST OF THIS UPCOMING
WEEK.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 950 AM EDT MON APR 28 2014
RADAR MOSAIC AT 930 AM SHOWS LARGE AREA OF RAIN OVER THE NORTHEAST
HALF OR SO OF THE AREA MOVING OFF TO THE NORTHEAST WITH MORE RAIN
OVER SOUTHERN ILLINOIS/WESTERN KENTUCKY MOVING NORTHEAST AS WELL
TOWARD SOUTHERN INDIANA. VISIBLE SATELLITE SHOWS A CLEAR SLOT OVER
CENTRAL ILLINOIS...BUT A LOOP OF THIS FEATURE SHOWS IT ROTATING
MAINLY TO THE NORTH AND THUS COULD STAY OVER ILLINOIS AND MOVE INTO
NORTHERN INDIANA BUT KEEP CENTRAL INDIANA IN MOSTLY TO COMPLETELY
CLOUDY SKIES FOR THE DAY. FOR THE UPDATE ADDED SOME TIMING FOR POPS
FOR THE REST OF THE MORNING/EARLY AFTERNOON WITH A BREAK IN PRECIP
MOVING IN FROM THE EAST AND LASTING FOR THE NEXT FEW HOURS. KEPT
HIGH CHANCE TO LIKELY POPS GOING IN THE SOUTH FOR THE AFOREMENTIONED
ECHOES MOVING NORTHEAST FROM S IL/W KY. HI RES MODELS ARE SHOWING
DIFFERENT SCENARIOS FOR THE AFTERNOON/EARLY EVENING AND THIS IS
CONTRIBUTING TO HIGH UNCERTAINTY FOR THAT PERIOD. HRRR SHOWS ALL
DEVELOPMENT OCCURRING TO THE NORTH OF THE AREA WITH NOTHING FURTHER
UNTIL THE COLD FRONT ARRIVES LATER TONIGHT. RAP CONTINUES TO DEVELOP
SCATTERED CONVECTION THIS AFTERNOON. HESITANT TO BUY INTO HRRR HOOK
LINE AND SINKER WITH SUCH A DYNAMIC SYSTEM SO WENT WITH LOW CHANCE
POPS ACROSS THE AREA LATE MORNING/EARLY AFTERNOON INCREASING TO
LIKELY ACROSS THE AREA AFTER 20Z. AGAIN WITH MODEL VARIABILITY...NOT
READY TO CHANGE SEVERE OUTLOOK OR TIMING FROM PREVIOUS FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
ADDITIONAL DEVELOPMENT LATER TODAY A LITTLE MORE QUESTIONABLE...AS
SOME OF THE MODEL DATA SUGGEST MORE SHOWER/THUNDERSTORMS DEVELOPMENT
THIS AFTERNOON ALONG THE EDGE OF THE APPROACHING DRY SLOT/STEEPER
LAPSE RATES...WHILE OTHERS SUGGEST DEVELOPMENT MAY HOLD OFF UNTIL
TOWARDS/AFTER 290000Z WHEN SURFACE COLD FRONT/OCCLUSION MOVES
THROUGH. AT THIS POINT...WILL KEEP RATHER HIGH POPS GOING THROUGH
ABOUT MIDNIGHT TONIGHT...WITH THE HIGHEST POPS THROUGH ABOUT MIDDAY
TODAY.
SEVERE POTENTIAL TODAY AND TONIGHT A LITTLE LESS CLEAR. MODEL DATA
STILL SUGGEST ADEQUATE DEEP SHEAR/LAPSE RATES BY LATER THIS
AFTERNOON AND TONIGHT FOR SEVERE...ALTHOUGH THE DEEP SHEAR LOOKS A
LITTLE WEAKER TODAY THAN IT DID YESTERDAY. ALSO...LARGE AMOUNTS OF
CONVECTION DEVELOPING SOUTH OF THE OHIO RIVER IS GETTING CLOSE TO
CUTTING OFF THE FLOW OF DEEPER MOISTURE/MORE UNSTABLE AIR INTO THE
AREA. APPEARS THE BEST CHANCE FOR SEVERE WILL BE FROM THE MID
AFTERNOON HOURS UNTIL ABOUT MIDNIGHT TONIGHT...EMANATING EITHER FROM
DEVELOPMENT ALONG THE EDGE OF DRY SLOT LATER THIS AFTERNOON OR WITH
ACTIVITY TONIGHT NEAR THE SURFACE FRONT.
TODAY/S GFS MOS SEEMS TO MAY LOST ITS WARM BIAS OF THE PAST COUPLE
OF DAYS...AND THE NUMBERS FOR TODAY AND TONIGHT LOOK MORE REASONABLE.
ONLY MINOR ADJUSTMENTS PLANNED.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 304 AM EDT MON APR 28 2014
MODEL DATA SUGGEST A LARGE UPPER LOW WILL GRADUALLY SHIFT NORTHEAST
FROM THE PLAINS INTO THE MIDWEST DURING THIS PERIOD...KEEPING THE
WEATHER UNSETTLED.
BY TUESDAY...MODEL DATA SUGGEST DRIER AIR WRAPPING AROUND THE UPPER
LOW WILL MOVE INTO THE AREA. LAPSE RATES ARE QUITE STEEP ON
TUESDAY...HOWEVER BETTER SHEAR PUSHES OFF TO THE EAST WITH TIME.
WILL GO WITH CHANCE POPS FOR SHOWERS/THUNDERSTORMS ON TUESDAY AND
TUESDAY NIGHT AS A SURFACE TROUGH MOVES THROUGH...WHICH MAY SERVE AS
FOCUS FOR CONVECTION. THE PRESENCE OF THE STEEP LAPSE RATES ON
TUESDAY SUGGEST HAIL POTENTIAL WITH ANY STRONGER CELLS THAT MAY
DEVELOP.
WILL KEEP SOME CHANCE POPS GOING INTO WEDNESDAY AND WEDNESDAY NIGHT
AS FILLING UPPER LOW MOVES INTO THE GREAT LAKES.
BASED OFF ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS HIGHS FOR
TUESDAY AND WEDNESDAY LOOK A LITTLE WARM. WILL CUT A FEW DEGREES OFF
THE GUIDANCE HIGHS ON BOTH DAYS. LOWS LOOK REASONABLE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 338 AM EDT MON APR 28 2014
A LARGE UPPER LOW OVER THE GREAT LAKES THURSDAY WILL LIFT NORTH INTO
SOUTHERN CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR
WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY.
A CYCLONIC UPPER FLOW FROM THIS UPPER LOW WILL KEEP MOSTLY CLOUDY
SKIES AND CHANCES OF SHOWERS THURSDAY INTO SATURDAY. A WEAK COLD
FRONT WILL MOVE ACROSS OUR REGION EARLY SATURDAY FOLLOWED BY A HIGH
PRESSURE RIDGE SATURDAY NIGHT. SEVERAL MODELS INDICATE ANOTHER
CHANCE OF PRECIPITATION MAY BEGIN SUNDAY AS ANOTHER SYSTEM
APPROACHES.
ADDED ISOLATED THUNDER TO SUNDAY AS MODELS INDICATE MU CAPES OF UP
TO 500 J/KG. OTHERWISE...ANY PRECIPITATION WILL BE ONLY BE
SCATTERED LIGHT SHOWERS OR SPRINKLES.
TEMPERATURES WILL REMAIN QUITE COOL THURSDAY THROUGH SATURDAY AND
THEN MODERATE A LITTLE SUNDAY. ONLY MADE MINOR TWEAKS TO ALL BLEND
TEMPERATURES MAINLY TO RAISE MINS SLIGHTLY THURSDAY AND FRIDAY NIGHT
AS THERE WILL BE LOTS OF CLOUDS.
&&
.AVIATION /DISCUSSION FOR 281200Z TAF ISSUANCE/...
ISSUED AT 1032 AM EDT MON APR 28 2014
1430Z UPDATE...FEW UPDATES TO THE TAFS. REMOVED -SHRA AND TS FOR
THE NEXT SEVERAL HOURS AND LOWERED THE FLIGHT CATEGORY TO IFR FOR
THE NEXT SEVERAL HOURS AT OUTLYING SITES SUCH AS KHUF AND KBMG
BASED ON OBSERVATIONS. KIND AND KLAF APPEAR TO BE REMAINING AT
MFVR AND GETTING DOUBTFUL THEY WILL REACH VFR BEFORE NEXT SYSTEM
MOVES THROUGH LATER TODAY. PREVIOUS DISC FOLLOWS.
NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS EARLY THIS MORNING.
THERE COULD BE ANOTHER PERIOD OF NUMEROUS SHOWERS AND THUNDERSTORMS
LATE THIS AFTERNOON OR EARLY TONIGHT PER MODELS. OTHERWISE...WILL
MENTION VCSH REST OF THE PERIOD THROUGH MIDNIGHT TONIGHT.
STRONG LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE SLOWLY
NORTHEAST INTO THE UPPER MIDWEST. SHOWERS AND A FEW THUNDERSTORMS
THIS MORNING MAY IN MVFR CONDITIONS AT TIME. MOST OF THE SHOWERS
SHOULD MOVE OUT BY 15Z...BUT AREAS OF MVFR CEILINGS MAY PERSIST INTO
MIDDAY.
SEVERAL MODELS INDICATE THERE COULD BE ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. WILL ADD
ANOTHER PERIOD OF VCTS AS A RESULT FROM 20Z TO ABOUT 05Z. NAM
REFLECTIVITY MODEL MOST OF THIS WILL MOVE OUT AFTER MIDNIGHT AS A
DRY SLOT PUSHES INTO OUR AREA. COULD BE ANOTHER PERIOD OF MVFR
CEILINGS TONIGHT.
EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE
TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/CP
SHORT TERM...JAS
LONG TERM....JH
AVIATION...SMF/JH
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
950 AM EDT MON APR 28 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 304 AM EDT MON APR 28 2014
A LARGE AND SLOW MOVING LOW PRESSURE SYSTEM IS EXPECTED TO GRADUALLY
MOVE FROM THE PLAINS INTO THE GREAT LAKES REGION BY LATE THIS WEEK.
THIS LOW WILL KEEP THE WEATHER UNSETTLED FOR MOST OF THIS UPCOMING
WEEK.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 950 AM EDT MON APR 28 2014
RADAR MOSAIC AT 930 AM SHOWS LARGE AREA OF RAIN OVER THE NORTHEAST
HALF OR SO OF THE AREA MOVING OFF TO THE NORTHEAST WITH MORE RAIN
OVER SOUTHERN ILLINOIS/WESTERN KENTUCKY MOVING NORTHEAST AS WELL
TOWARD SOUTHERN INDIANA. VISIBLE SATELLITE SHOWS A CLEAR SLOT OVER
CENTRAL ILLINOIS...BUT A LOOP OF THIS FEATURE SHOWS IT ROTATING
MAINLY TO THE NORTH AND THUS COULD STAY OVER ILLINOIS AND MOVE INTO
NORTHERN INDIANA BUT KEEP CENTRAL INDIANA IN MOSTLY TO COMPLETELY
CLOUDY SKIES FOR THE DAY. FOR THE UPDATE ADDED SOME TIMING FOR POPS
FOR THE REST OF THE MORNING/EARLY AFTERNOON WITH A BREAK IN PRECIP
MOVING IN FROM THE EAST AND LASTING FOR THE NEXT FEW HOURS. KEPT
HIGH CHANCE TO LIKELY POPS GOING IN THE SOUTH FOR THE AFOREMENTIONED
ECHOES MOVING NORTHEAST FROM S IL/W KY. HI RES MODELS ARE SHOWING
DIFFERENT SCENARIOS FOR THE AFTERNOON/EARLY EVENING AND THIS IS
CONTRIBUTING TO HIGH UNCERTAINTY FOR THAT PERIOD. HRRR SHOWS ALL
DEVELOPMENT OCCURRING TO THE NORTH OF THE AREA WITH NOTHING FURTHER
UNTIL THE COLD FRONT ARRIVES LATER TONIGHT. RAP CONTINUES TO DEVELOP
SCATTERED CONVECTION THIS AFTERNOON. HESITANT TO BUY INTO HRRR HOOK
LINE AND SINKER WITH SUCH A DYNAMIC SYSTEM SO WENT WITH LOW CHANCE
POPS ACROSS THE AREA LATE MORNING/EARLY AFTERNOON INCREASING TO
LIKELY ACROSS THE AREA AFTER 20Z. AGAIN WITH MODEL VARIABILITY...NOT
READY TO CHANGE SEVERE OUTLOOK OR TIMING FROM PREVIOUS FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
ADDITIONAL DEVELOPMENT LATER TODAY A LITTLE MORE QUESTIONABLE...AS
SOME OF THE MODEL DATA SUGGEST MORE SHOWER/THUNDERSTORMS DEVELOPMENT
THIS AFTERNOON ALONG THE EDGE OF THE APPROACHING DRY SLOT/STEEPER
LAPSE RATES...WHILE OTHERS SUGGEST DEVELOPMENT MAY HOLD OFF UNTIL
TOWARDS/AFTER 290000Z WHEN SURFACE COLD FRONT/OCCLUSION MOVES
THROUGH. AT THIS POINT...WILL KEEP RATHER HIGH POPS GOING THROUGH
ABOUT MIDNIGHT TONIGHT...WITH THE HIGHEST POPS THROUGH ABOUT MIDDAY
TODAY.
SEVERE POTENTIAL TODAY AND TONIGHT A LITTLE LESS CLEAR. MODEL DATA
STILL SUGGEST ADEQUATE DEEP SHEAR/LAPSE RATES BY LATER THIS
AFTERNOON AND TONIGHT FOR SEVERE...ALTHOUGH THE DEEP SHEAR LOOKS A
LITTLE WEAKER TODAY THAN IT DID YESTERDAY. ALSO...LARGE AMOUNTS OF
CONVECTION DEVELOPING SOUTH OF THE OHIO RIVER IS GETTING CLOSE TO
CUTTING OFF THE FLOW OF DEEPER MOISTURE/MORE UNSTABLE AIR INTO THE
AREA. APPEARS THE BEST CHANCE FOR SEVERE WILL BE FROM THE MID
AFTERNOON HOURS UNTIL ABOUT MIDNIGHT TONIGHT...EMANATING EITHER FROM
DEVELOPMENT ALONG THE EDGE OF DRY SLOT LATER THIS AFTERNOON OR WITH
ACTIVITY TONIGHT NEAR THE SURFACE FRONT.
TODAY/S GFS MOS SEEMS TO MAY LOST ITS WARM BIAS OF THE PAST COUPLE
OF DAYS...AND THE NUMBERS FOR TODAY AND TONIGHT LOOK MORE REASONABLE.
ONLY MINOR ADJUSTMENTS PLANNED.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 304 AM EDT MON APR 28 2014
MODEL DATA SUGGEST A LARGE UPPER LOW WILL GRADUALLY SHIFT NORTHEAST
FROM THE PLAINS INTO THE MIDWEST DURING THIS PERIOD...KEEPING THE
WEATHER UNSETTLED.
BY TUESDAY...MODEL DATA SUGGEST DRIER AIR WRAPPING AROUND THE UPPER
LOW WILL MOVE INTO THE AREA. LAPSE RATES ARE QUITE STEEP ON
TUESDAY...HOWEVER BETTER SHEAR PUSHES OFF TO THE EAST WITH TIME.
WILL GO WITH CHANCE POPS FOR SHOWERS/THUNDERSTORMS ON TUESDAY AND
TUESDAY NIGHT AS A SURFACE TROUGH MOVES THROUGH...WHICH MAY SERVE AS
FOCUS FOR CONVECTION. THE PRESENCE OF THE STEEP LAPSE RATES ON
TUESDAY SUGGEST HAIL POTENTIAL WITH ANY STRONGER CELLS THAT MAY
DEVELOP.
WILL KEEP SOME CHANCE POPS GOING INTO WEDNESDAY AND WEDNESDAY NIGHT
AS FILLING UPPER LOW MOVES INTO THE GREAT LAKES.
BASED OFF ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS HIGHS FOR
TUESDAY AND WEDNESDAY LOOK A LITTLE WARM. WILL CUT A FEW DEGREES OFF
THE GUIDANCE HIGHS ON BOTH DAYS. LOWS LOOK REASONABLE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 338 AM EDT MON APR 28 2014
A LARGE UPPER LOW OVER THE GREAT LAKES THURSDAY WILL LIFT NORTH INTO
SOUTHERN CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR
WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY.
A CYCLONIC UPPER FLOW FROM THIS UPPER LOW WILL KEEP MOSTLY CLOUDY
SKIES AND CHANCES OF SHOWERS THURSDAY INTO SATURDAY. A WEAK COLD
FRONT WILL MOVE ACROSS OUR REGION EARLY SATURDAY FOLLOWED BY A HIGH
PRESSURE RIDGE SATURDAY NIGHT. SEVERAL MODELS INDICATE ANOTHER
CHANCE OF PRECIPITATION MAY BEGIN SUNDAY AS ANOTHER SYSTEM
APPROACHES.
ADDED ISOLATED THUNDER TO SUNDAY AS MODELS INDICATE MU CAPES OF UP
TO 500 J/KG. OTHERWISE...ANY PRECIPITATION WILL BE ONLY BE
SCATTERED LIGHT SHOWERS OR SPRINKLES.
TEMPERATURES WILL REMAIN QUITE COOL THURSDAY THROUGH SATURDAY AND
THEN MODERATE A LITTLE SUNDAY. ONLY MADE MINOR TWEAKS TO ALL BLEND
TEMPERATURES MAINLY TO RAISE MINS SLIGHTLY THURSDAY AND FRIDAY NIGHT
AS THERE WILL BE LOTS OF CLOUDS.
&&
.AVIATION /DISCUSSION FOR 281200Z TAF ISSUANCE/...
ISSUED AT 700 AM EDT MON APR 28 2014
NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS EARLY THIS MORNING.
THERE COULD BE ANOTHER PERIOD OF NUMEROUS SHOWERS AND THUNDERSTORMS
LATE THIS AFTERNOON OR EARLY TONIGHT PER MODELS. OTHERWISE...WILL
MENTION VCSH REST OF THE PERIOD THROUGH MIDNIGHT TONIGHT.
STRONG LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE SLOWLY
NORTHEAST INTO THE UPPER MIDWEST. SHOWERS AND A FEW THUNDERSTORMS
THIS MORNING MAY IN MVFR CONDITIONS AT TIME. MOST OF THE SHOWERS
SHOULD MOVE OUT BY 15Z...BUT AREAS OF MVFR CEILINGS MAY PERSIST INTO
MIDDAY.
SEVERAL MODELS INDICATE THERE COULD BE ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. WILL ADD
ANOTHER PERIOD OF VCTS AS A RESULT FROM 20Z TO ABOUT 05Z. NAM
REFLECTIVITY MODEL MOST OF THIS WILL MOVE OUT AFTER MIDNIGHT AS A
DRY SLOT PUSHES INTO OUR AREA. COULD BE ANOTHER PERIOD OF MVFR
CEILINGS TONIGHT.
EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE
TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/CP
SHORT TERM...JAS
LONG TERM....JH
AVIATION...50/JH
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1238 PM CDT MON APR 28 2014
.UPDATE...
ISSUED AT 1126 AM CDT MON APR 28 2014
THE FRONTAL BOUNDARY IS ROUGHLY ALONG A KTQE...KAWG...TO KCMI LINE
AT 16Z AND IT HAS NOT MOVED FOR SEVERAL HOURS.
TRENDS IN THE RAP INDICATE VERY LITTLE IN THE WAY OF MOMENT OF
THIS FRONTAL BOUNDARY THIS AFTERNOON. IF CORRECT...ROUGHLY THE
NORTHERN HALF OF THE AREA WILL REMAIN IN THE 50S WITH THE HWY 20
CORRIDOR POSSIBLY STRUGGLING TO REACH 50.
SATELLITE TRENDS INDICATE THERMALS ARE ACTIVE WHICH HAS ALLOWED CU
TO DEVELOP ALONG/AHEAD OF THE COLD FRONT ACROSS MISSOURI.
CONVECTION SHOULD DEVELOP WITHIN A FEW HOURS FROM CENTRAL INTO
SOUTHERN MISSOURI ALONG THE FRONT AND MOVE NORTHEAST.
PRECIPITATION CHANCES SHOULD THEREFORE BE ON THE INCREASE STARTING
AROUND MID AFTERNOON ACROSS THE AREA.
UPDATE ISSUED AT 923 AM CDT MON APR 28 2014
RADAR TRENDS INDICATE SHOWERS ACROSS THE NORTHERN PARTS OF THE
AREA WILL CONTINUE TO SLOWLY DECAY THE REMAINDER OF THE MORNING.
CLOUDS AND STRONG EASTERLY FLOW NORTH OF THE PRONOUNCED FRONT
SOUTH OF I-80 WILL KEEP THIS AREA COOL FOR MUCH OF THE DAY. STRONG
DIURNAL HEATING SOUTH OF THE FRONT IS EXPECTED TO SET THE STAGE
FOR NEW CONVECTION DEVELOPING EITHER LATE THIS MORNING OR DURING
THE EARLY AFTERNOON. SATELLITE TRENDS HAS A NARROW BAND OF ACCAS
IN SOUTHERN MISSOURI INDICATING INSTABILITY FOR NEW STORMS TO
DEVELOP.
&&
.SYNOPSIS...
ISSUED AT 357 AM CDT MON APR 28 2014
NEARLY STACKED SURFACE AND UPPER LEVEL LOWS WERE LOCATED OVER
CENTRAL NEB EARLY THIS MORNING. WELL OUT IN ADVANCE...AN ELONGATED
COMPLEX OF SEVERE STORMS STRETCHED FROM EASTERN TX THROUGH THE MID
MS VALLEY INTO THE OHIO RIVER VALLEY. OVER THE LOCAL AREA...
WIDESPREAD SHOWERS AND THUNDERSTORMS SUNDAY EVENING HAVE SINCE
STRATIFORMED INTO MAINLY WEAKENING LIGHT SHOWERS DRIFTING NORTHWARD
THROUGH THE REGION. STRONG EASTERLY WINDS CONTINUE...FROM 20 TO 30 MPH AND
AS HIGH AS 30 TO 40 MPH AT TIMES MAINLY NORTH OF I-80. TO THE
SOUTH...WINDS WERE MUCH LIGHTER AND VEERED TO MORE SOUTHEASTERLY
ALONG AND SOUTH OF THE MAIN STATIONARY FRONT CONNECTED TO THE NEB
LOW. IN THE LOCAL AREA THIS BOUNDARY RAN ROUGHLY FROM JUST NORTH OF
WASHINGTON SOUTHEAST TO NORTH OF MACOMB. TEMPERATURES AND DEWPOINTS
WERE IN THE UPPER 50S TO LOWER 60S SOUTH OF THIS BOUNDARY...WHILE TO
THE NORTH TEMPERATURES RANGED FROM THE LOWER 40S NORTH TO LOWER 50S
ALONG THE I-80 CORRIDOR.
&&
.SHORT TERM...(TODAY)
ISSUED AT 357 AM CDT MON APR 28 2014
FOCUS IS ON THREAT FOR MORE SEVERE WEATHER TODAY. SHARP FRONTAL
BOUNDARY WILL LIKELY REMAIN IN PLACE ACROSS THE SOUTH THROUGH
MIDDAY...THEN TRY TO LIFT NORTH TOWARD EVENING. PRIMARY SEVERE
WEATHER THREAT WILL BE CENTERED PRIMARILY ON SE IA INTO W CENTRAL IL
THIS AFTERNOON. UPPER LEVEL DIFLUENCE AND MID LEVEL LIFT ASSOCIATED
WITH A LOBE OF ENERGY ROTATING AROUND THE BASE OF THE NEB LOW FOCUSES
ON THIS REGION BY AFTERNOON. THIS WILL ENHANCE LIFT OVER THE FRONTAL
BOUNDARY...AND WHERE MODELS INDICATE A POTENTIAL FOR MIXED LAYER
CAPES OF 1000 J/KG OR HIGHER...SEVERE STORMS WITH LARGE HAIL AND
DAMAGING WIND WILL BE POSSIBLE. THIS APPEARS TO BE MAXIMIZED OVER
FAR SE IA INTO W CENTRAL IL...WHERE SPC HAS A SLIGHT RISK. IT IS IN
THIS REGION THAT THE BETTER SHEAR OVER THE EAST AND HIGHER
INSTABILITY AXIS FROM CENTRAL IL REACHING INTO CENTRAL IA MAY
OVERLAP. THERE WILL BE A RISK OF TORNADIC STORMS...ESPECIALLY IF
THE MODEL ADVERTISED WEAK LOW OR TRIPLE POINT MIGRATES EASTWARD
ALONG THE BOUNDARY INTO THIS MORE FAVORABLE ENVIRONMENT. IF THE
BOUNDARY WERE TO PUSH FURTHER NORTH THAN ANTICIPATED DURING PEAK
HEATING...AS SOME MODELS DEPICT...THIS RISK OF SEVERE STORMS WOULD EXTEND
FURTHER NORTH.
THE RISK FOR HEAVY RAIN APPEARS TO BE SOMEWHAT LESS CERTAIN
CONSIDERING THE LARGE COMPLEXES TO THE SOUTH THAT MAY INTERRUPT THE
MOISTURE FEED. THE GREATEST FEED OF DEEP MOISTURE APPEARS TO BE
MAXIMIZED OVER THE AREA TONIGHT...THEN MODEL PW FIELDS SHOW A
WEAKENING AREA AXIS REACHING INTO NORTHERN IL AND EASTERN IA FROM
THE SOUTHEAST TODAY. ANY SEVERE STORMS THAT DEVELOP THIS AFTERNOON
WILL CERTAINLY BE CAPABLE OF HEAVY RAINFALL...BUT OUTSIDE OF THESE...
RAINFALL AMOUNTS SHOULD NOT BE EXCESSIVE AND HAVE QPF AMOUNTS
GENERALLY IN A QUARTER TO HALF INCH RANGE. THE SHARP BOUNDARY WILL
AGAIN RESULT IN A WIDE RANGE OF TEMPERATURE AND HAVE HIGHS FROM
THE 50S AND 60S ACROSS THE NORTH WITH 70S FAR SOUTH. ..11..
.LONG TERM...(TONIGHT THROUGH NEXT SUNDAY)
ISSUED AT 357 AM CDT MON APR 28 2014
TONIGHT...SEVERAL HIRES PROGS AND ASSESSING STANDARD 00Z RUN
MODELS SUGGEST AN ARCING CLUSTER OF SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO PUSH NORTH AND NORTHEAST ACRS THE NORTHERN 2/3S OF THE
DVN CWA EARLY THIS EVENING WHILE NEARLY STACKED VORTEX ROLLS ACRS
SOUTHWESTERN IA. LINGERING SHEAR AND THERMODYNAMIC PROFILES STILL
SUGGEST A FEW STORMS MAY BE STRONG OR SVR THROUGH 02Z TUE ALONG AND
JUST NORTH OF OCCLUDED SFC FRONT WHICH IS GENERALLY SREF PLACED ALONG
I80...BUT WONDER IF MODELS ARE TOO FAR NORTH WITH THIS FEATURE STILL
AT THIS POINT. MUCH OF THE CONVECTIVE ACTIVITY MAY THEN BE ON THE
WANE AND EXITING TO THE NORTH OF THE DVN CWA AFTER 03Z THIS
EVENING...WITH ADDITIONAL RAINFALL AMOUNTS OF 0.25 TO 0.75 OF AN INCH
WHERE THE BAND/MAIN CLUSTER OF STORMS MIGRATES NORTHWARD ACRS.
CURRENT THINKING THIS ALONG AND NORTH OF I80 AN TARGETING THE
NORTHEASTERN THIRD OF THE DVN CWA. WILL HAVE TO WATCH FOR LOW
CLOUDS...FOG AND DRIZZLE IN VCNTY OF LINGERING OCCLUSION OVERNIGHT
AFTER THE RAIN CLEARS. WILL HAVE TO WATCH FOR ADDITIONAL WRAP-AROUND
SHOWERS OR HYBRID RAIN BANDS ENTERING THE NORTHWESTERN CWA TOWARD
DAWN TUE AS UPPER LOW PUSHES TOWARD THE WESTERN CWA. LOW OVERNIGHT
GENERALLY IN THE 40S.
TUESDAY AND WEDNESDAY...LATEST 00Z RUN MEDIUM RANGE SOLUTIONS
CONTINUE TO SUGGEST LARGE SUB TROPICAL VORTEX-NEARLY STACKED
MONSTER CYCLONE TO SLOW ROLL IN SOME FASHION ACRS IA TOWARD THE
WESTERN GRT LKS THIS PERIOD. WITH THE CENTER OVERHEAD AND DIURNALLY
UNSTABLE SOUNDINGS DEVELOPING ON TUE...FEEL THERE COULD BE MORE
SCTRD TO ISOLATED THUNDERSTORMS ALONG WITH INHERENT SHOWERS AS THE
DAY PROGRESSES. VERTICAL THERMAL PROFILES AND IDEAL WBZ/FZL HEIGHTS
CONTINUE TO SUGGEST SOME OF THESE STORMS COULD PRODUCE HAIL WITH ANY
SUSTAINED UPDRAFTS. SCTRD SHOWERS/STORMS TO WANE DIURNALLY AFTER
SUNSET TUE NIGHT INTO EARLY WED MORNING. AMBIENT TEMPS TO COOL BY WED
INTO THE MID 50S OR EVEN THE UPPER 40S AS LOW TO MID LEVEL COLD
CONVEYOR INCREASES INTO THE BACKSIDE OF CYCLONE COMPLEX. MORE SHOWERS
WED AS SATELLITE VORT SPOKE ROTATES ACRS THE REGION.
THURSDAY THROUGH NEXT SUNDAY...LONGER RANGE INDICATIONS ARE NOW A
BIT MORE PROGRESSIVE/LESS BLOCKED WITH UPPER LOW ROLLING ALONG
INTO THE GRT LKS OR EVEN TOWARD THE SOUTHERN JAMES BAY REGION
BY FRI. STILL EXPECT OCCASIONAL ROUNDS OF SHOWERS ESPECIALLY
DURING THE DAY...AS WELL AS WELL BELOW NORMAL TEMPS THROUGH THE
PERIOD. HIGHS THU AND FRI ONLY IN THE 50S...HAPPY MAY DAY. RESULTANT
LARGE/BROAD SCALE L/W UPPER TROF PATTERN ACRS THE EASTERN HALF OF THE
CONUS TO CONTINUE A RATHER COOL TEMP REGIME INTO THE WEEKEND FOR MUCH
OF THE UPPER MIDWEST/MS RVR VALLEY REGION. BUT THEN LONGER RANGE
SIGNALS AND UPPER JET PATTERNS SUGGEST A FLATTENING OF THE MEAN
STEERING FLOW REGIME ACRS MUCH OF THE CONUS AS THE WEEKEND
PROGRESSES. EMBEDDED RIDGE RIDING/DAMPENING WAVE AND SOME LLVL
BAROCLINIC TIGHTENING MAY COMBINE TO BRING MORE RAIN CHANCES TO THE
REGION BY LATE SAT NIGHT OR NEXT SUNDAY. ..12..
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1235 PM CDT MON APR 28 2014
IFR CONDS THROUGH MOST OF THIS TAF CYCLE AT KCID/KDBQ OTHERWISE
IFR AT KMLI BECOMING MVFR CONDS THIS EVENING. VFR CONDS THROUGH
THIS TAF CYCLE AT KBRL. A LINE OF THUNDERSTORMS SHOULD DEVELOP IN
SOUTHEAST IA EARLY TO MID AFTERNOON IMPACTING KBRL AND THEN SPREADING
NORTHEAST OVER THE REMAINING TAF SITES LATE THIS AFTERNOON AND EVENING.
SOME OF THE STORMS ALONG AND SOUTH OF I-80 MAY PRODUCE LARGE HAIL
AND DAMAGING WINDS. EAST TO SOUTHEAST WINDS SUSTAINED 15 TO 20
KNOTS WITH GUSTS TO 25 TO 30 KNOTS THIS AFTERNOON...DIMINISHING TO
LESS THAN 10 KNOTS THIS EVENING. NORTHEAST WINDS LESS THAN 10
KNOTS ON TUESDAY AT KCID/KDBQ BUT SOUTHWEST WINDS AT KMLI/KBRL.
&&
.HYDROLOGY...
ISSUED AT 357 AM CDT MON APR 28 2014
THE FLOOD WATCH FOR AREA RIVERS AND STREAMS CONTINUES TODAY AND
THIS EVENING. THE THREAT OF FLOODING ON AREA TRIBUTARIES AND THE
MISSISSIPPI RIVER WILL INCREASE AS THE WEEK PROGRESSES WITH A
ACCUMULATIVE EFFECT OF SEVERAL RAIN EVENTS...INCLUDING THIS PAST
SUNDAY EVENING/S HEAVY RAIN...THEN MORE LOCALIZED HEAVY RAIN POSSIBLE
THIS AFTERNOON AND EVENING. LATEST THINKING SUGGESTS WIDESPREAD
RAINFALL AMOUNTS OF 1 TO 4 INCHES WILL FALL OVER MUCH OF THE FORECAST
AREA BY WEDNESDAY...INCLUDING THE RAINFALL FROM YESTERDAY AND LAST
NIGHT. SINCE THE PRECIPITATION WILL OCCUR OVER AN EXTENDED PERIOD OF
TIME...THE THREAT OF FLASH FLOODING WILL BE LOW. HOWEVER...RIVER
FLOODING IS EXPECTED WITH SEVERAL OF THE AREA TRIBUTARIES AND THE
MISSISSIPPI RIVER POSSIBLY SEEING AT LEAST MINOR TO MODERATE FLOODING
BY THE MIDDLE OF THE WEEK.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FLOOD WATCH UNTIL MIDNIGHT CDT TONIGHT FOR BENTON-BUCHANAN-CEDAR-
CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-JACKSON-
JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-MUSCATINE-
SCOTT-VAN BUREN-WASHINGTON.
IL...FLOOD WATCH UNTIL MIDNIGHT CDT TONIGHT FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...FLOOD WATCH UNTIL MIDNIGHT CDT TONIGHT FOR CLARK-SCOTLAND.
&&
$$
UPDATE...08
SYNOPSIS...11
SHORT TERM...11
LONG TERM...12
AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1134 AM CDT MON APR 28 2014
.UPDATE...
ISSUED AT 1126 AM CDT MON APR 28 2014
THE FRONTAL BOUNDARY IS ROUGHLY ALONG A KTQE...KAWG...TO KCMI LINE
AT 16Z AND IT HAS NOT MOVED FOR SEVERAL HOURS.
TRENDS IN THE RAP INDICATE VERY LITTLE IN THE WAY OF MOMENT OF
THIS FRONTAL BOUNDARY THIS AFTERNOON. IF CORRECT...ROUGHLY THE
NORTHERN HALF OF THE AREA WILL REMAIN IN THE 50S WITH THE HWY 20
CORRIDOR POSSIBLY STRUGGLING TO REACH 50.
SATELLITE TRENDS INDICATE THERMALS ARE ACTIVE WHICH HAS ALLOWED CU
TO DEVELOP ALONG/AHEAD OF THE COLD FRONT ACROSS MISSOURI.
CONVECTION SHOULD DEVELOP WITHIN A FEW HOURS FROM CENTRAL INTO
SOUTHERN MISSOURI ALONG THE FRONT AND MOVE NORTHEAST.
PRECIPITATION CHANCES SHOULD THEREFORE BE ON THE INCREASE STARTING
AROUND MID AFTERNOON ACROSS THE AREA.
UPDATE ISSUED AT 923 AM CDT MON APR 28 2014
RADAR TRENDS INDICATE SHOWERS ACROSS THE NORTHERN PARTS OF THE
AREA WILL CONTINUE TO SLOWLY DECAY THE REMAINDER OF THE MORNING.
CLOUDS AND STRONG EASTERLY FLOW NORTH OF THE PRONOUNCED FRONT
SOUTH OF I-80 WILL KEEP THIS AREA COOL FOR MUCH OF THE DAY. STRONG
DIURNAL HEATING SOUTH OF THE FRONT IS EXPECTED TO SET THE STAGE
FOR NEW CONVECTION DEVELOPING EITHER LATE THIS MORNING OR DURING
THE EARLY AFTERNOON. SATELLITE TRENDS HAS A NARROW BAND OF ACCAS
IN SOUTHERN MISSOURI INDICATING INSTABILITY FOR NEW STORMS TO
DEVELOP.
&&
.SYNOPSIS...
ISSUED AT 357 AM CDT MON APR 28 2014
NEARLY STACKED SURFACE AND UPPER LEVEL LOWS WERE LOCATED OVER
CENTRAL NEB EARLY THIS MORNING. WELL OUT IN ADVANCE...AN ELONGATED
COMPLEX OF SEVERE STORMS STRETCHED FROM EASTERN TX THROUGH THE MID
MS VALLEY INTO THE OHIO RIVER VALLEY. OVER THE LOCAL AREA...
WIDESPREAD SHOWERS AND THUNDERSTORMS SUNDAY EVENING HAVE SINCE
STRATIFORMED INTO MAINLY WEAKENING LIGHT SHOWERS DRIFTING NORTHWARD
THROUGH THE REGION. STRONG EASTERLY WINDS CONTINUE...FROM 20 TO 30 MPH AND
AS HIGH AS 30 TO 40 MPH AT TIMES MAINLY NORTH OF I-80. TO THE
SOUTH...WINDS WERE MUCH LIGHTER AND VEERED TO MORE SOUTHEASTERLY
ALONG AND SOUTH OF THE MAIN STATIONARY FRONT CONNECTED TO THE NEB
LOW. IN THE LOCAL AREA THIS BOUNDARY RAN ROUGHLY FROM JUST NORTH OF
WASHINGTON SOUTHEAST TO NORTH OF MACOMB. TEMPERATURES AND DEWPOINTS
WERE IN THE UPPER 50S TO LOWER 60S SOUTH OF THIS BOUNDARY...WHILE TO
THE NORTH TEMPERATURES RANGED FROM THE LOWER 40S NORTH TO LOWER 50S
ALONG THE I-80 CORRIDOR.
&&
.SHORT TERM...(TODAY)
ISSUED AT 357 AM CDT MON APR 28 2014
FOCUS IS ON THREAT FOR MORE SEVERE WEATHER TODAY. SHARP FRONTAL
BOUNDARY WILL LIKELY REMAIN IN PLACE ACROSS THE SOUTH THROUGH
MIDDAY...THEN TRY TO LIFT NORTH TOWARD EVENING. PRIMARY SEVERE
WEATHER THREAT WILL BE CENTERED PRIMARILY ON SE IA INTO W CENTRAL IL
THIS AFTERNOON. UPPER LEVEL DIFLUENCE AND MID LEVEL LIFT ASSOCIATED
WITH A LOBE OF ENERGY ROTATING AROUND THE BASE OF THE NEB LOW FOCUSES
ON THIS REGION BY AFTERNOON. THIS WILL ENHANCE LIFT OVER THE FRONTAL
BOUNDARY...AND WHERE MODELS INDICATE A POTENTIAL FOR MIXED LAYER
CAPES OF 1000 J/KG OR HIGHER...SEVERE STORMS WITH LARGE HAIL AND
DAMAGING WIND WILL BE POSSIBLE. THIS APPEARS TO BE MAXIMIZED OVER
FAR SE IA INTO W CENTRAL IL...WHERE SPC HAS A SLIGHT RISK. IT IS IN
THIS REGION THAT THE BETTER SHEAR OVER THE EAST AND HIGHER
INSTABILITY AXIS FROM CENTRAL IL REACHING INTO CENTRAL IA MAY
OVERLAP. THERE WILL BE A RISK OF TORNADIC STORMS...ESPECIALLY IF
THE MODEL ADVERTISED WEAK LOW OR TRIPLE POINT MIGRATES EASTWARD
ALONG THE BOUNDARY INTO THIS MORE FAVORABLE ENVIRONMENT. IF THE
BOUNDARY WERE TO PUSH FURTHER NORTH THAN ANTICIPATED DURING PEAK
HEATING...AS SOME MODELS DEPICT...THIS RISK OF SEVERE STORMS WOULD EXTEND
FURTHER NORTH.
THE RISK FOR HEAVY RAIN APPEARS TO BE SOMEWHAT LESS CERTAIN
CONSIDERING THE LARGE COMPLEXES TO THE SOUTH THAT MAY INTERRUPT THE
MOISTURE FEED. THE GREATEST FEED OF DEEP MOISTURE APPEARS TO BE
MAXIMIZED OVER THE AREA TONIGHT...THEN MODEL PW FIELDS SHOW A
WEAKENING AREA AXIS REACHING INTO NORTHERN IL AND EASTERN IA FROM
THE SOUTHEAST TODAY. ANY SEVERE STORMS THAT DEVELOP THIS AFTERNOON
WILL CERTAINLY BE CAPABLE OF HEAVY RAINFALL...BUT OUTSIDE OF THESE...
RAINFALL AMOUNTS SHOULD NOT BE EXCESSIVE AND HAVE QPF AMOUNTS
GENERALLY IN A QUARTER TO HALF INCH RANGE. THE SHARP BOUNDARY WILL
AGAIN RESULT IN A WIDE RANGE OF TEMPERATURE AND HAVE HIGHS FROM
THE 50S AND 60S ACROSS THE NORTH WITH 70S FAR SOUTH. ..11..
.LONG TERM...(TONIGHT THROUGH NEXT SUNDAY)
ISSUED AT 357 AM CDT MON APR 28 2014
TONIGHT...SEVERAL HIRES PROGS AND ASSESSING STANDARD 00Z RUN
MODELS SUGGEST AN ARCING CLUSTER OF SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO PUSH NORTH AND NORTHEAST ACRS THE NORTHERN 2/3S OF THE
DVN CWA EARLY THIS EVENING WHILE NEARLY STACKED VORTEX ROLLS ACRS
SOUTHWESTERN IA. LINGERING SHEAR AND THERMODYNAMIC PROFILES STILL
SUGGEST A FEW STORMS MAY BE STRONG OR SVR THROUGH 02Z TUE ALONG AND
JUST NORTH OF OCCLUDED SFC FRONT WHICH IS GENERALLY SREF PLACED ALONG
I80...BUT WONDER IF MODELS ARE TOO FAR NORTH WITH THIS FEATURE STILL
AT THIS POINT. MUCH OF THE CONVECTIVE ACTIVITY MAY THEN BE ON THE
WANE AND EXITING TO THE NORTH OF THE DVN CWA AFTER 03Z THIS
EVENING...WITH ADDITIONAL RAINFALL AMOUNTS OF 0.25 TO 0.75 OF AN INCH
WHERE THE BAND/MAIN CLUSTER OF STORMS MIGRATES NORTHWARD ACRS.
CURRENT THINKING THIS ALONG AND NORTH OF I80 AN TARGETING THE
NORTHEASTERN THIRD OF THE DVN CWA. WILL HAVE TO WATCH FOR LOW
CLOUDS...FOG AND DRIZZLE IN VCNTY OF LINGERING OCCLUSION OVERNIGHT
AFTER THE RAIN CLEARS. WILL HAVE TO WATCH FOR ADDITIONAL WRAP-AROUND
SHOWERS OR HYBRID RAIN BANDS ENTERING THE NORTHWESTERN CWA TOWARD
DAWN TUE AS UPPER LOW PUSHES TOWARD THE WESTERN CWA. LOW OVERNIGHT
GENERALLY IN THE 40S.
TUESDAY AND WEDNESDAY...LATEST 00Z RUN MEDIUM RANGE SOLUTIONS
CONTINUE TO SUGGEST LARGE SUB TROPICAL VORTEX-NEARLY STACKED
MONSTER CYCLONE TO SLOW ROLL IN SOME FASHION ACRS IA TOWARD THE
WESTERN GRT LKS THIS PERIOD. WITH THE CENTER OVERHEAD AND DIURNALLY
UNSTABLE SOUNDINGS DEVELOPING ON TUE...FEEL THERE COULD BE MORE
SCTRD TO ISOLATED THUNDERSTORMS ALONG WITH INHERENT SHOWERS AS THE
DAY PROGRESSES. VERTICAL THERMAL PROFILES AND IDEAL WBZ/FZL HEIGHTS
CONTINUE TO SUGGEST SOME OF THESE STORMS COULD PRODUCE HAIL WITH ANY
SUSTAINED UPDRAFTS. SCTRD SHOWERS/STORMS TO WANE DIURNALLY AFTER
SUNSET TUE NIGHT INTO EARLY WED MORNING. AMBIENT TEMPS TO COOL BY WED
INTO THE MID 50S OR EVEN THE UPPER 40S AS LOW TO MID LEVEL COLD
CONVEYOR INCREASES INTO THE BACKSIDE OF CYCLONE COMPLEX. MORE SHOWERS
WED AS SATELLITE VORT SPOKE ROTATES ACRS THE REGION.
THURSDAY THROUGH NEXT SUNDAY...LONGER RANGE INDICATIONS ARE NOW A
BIT MORE PROGRESSIVE/LESS BLOCKED WITH UPPER LOW ROLLING ALONG
INTO THE GRT LKS OR EVEN TOWARD THE SOUTHERN JAMES BAY REGION
BY FRI. STILL EXPECT OCCASIONAL ROUNDS OF SHOWERS ESPECIALLY
DURING THE DAY...AS WELL AS WELL BELOW NORMAL TEMPS THROUGH THE
PERIOD. HIGHS THU AND FRI ONLY IN THE 50S...HAPPY MAY DAY. RESULTANT
LARGE/BROAD SCALE L/W UPPER TROF PATTERN ACRS THE EASTERN HALF OF THE
CONUS TO CONTINUE A RATHER COOL TEMP REGIME INTO THE WEEKEND FOR MUCH
OF THE UPPER MIDWEST/MS RVR VALLEY REGION. BUT THEN LONGER RANGE
SIGNALS AND UPPER JET PATTERNS SUGGEST A FLATTENING OF THE MEAN
STEERING FLOW REGIME ACRS MUCH OF THE CONUS AS THE WEEKEND
PROGRESSES. EMBEDDED RIDGE RIDING/DAMPENING WAVE AND SOME LLVL
BAROCLINIC TIGHTENING MAY COMBINE TO BRING MORE RAIN CHANCES TO THE
REGION BY LATE SAT NIGHT OR NEXT SUNDAY. ..12..
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 700 AM CDT MON APR 28 2014
CIGS WERE LOWERING TO IFR NORTH OF A STATIONARY FRONT REACHING
ACROSS SOUTHERN IOWA INTO CENTRAL ILLINOIS EARLY THIS MORNING. STRONG
EASTERLY WINDS NORTH OF THIS BOUNDARY WILL CONTINUE THROUGH MUCH
OF THE DAY AT CID...MLI...AND DBQ. THE IFR CONDITIONS DUE TO THE
LOW CIGS AND LIGHT FOG SHOULD IMPROVE TO MVFR BY MID MORNING AT
THESE SITES...WHILE BRL REMAINS VFR. THIS AFTERNOON...ANOTHER
ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED TO LIFT THROUGH THE
REGION. LATEST FORECASTS HAVE THIS HANDLED WITH A TEMPO GROUP AT
BRL...WHILE LOWER CONFIDENCE TIMING AND COVERAGE AFFECTING THE
OTHER TERMINALS WILL MAINTAIN PROB30 WORDING. WINDS WILL DIMINISH
TONIGHT AND VEER A BIT MORE SOUTHEASTERLY AS THE FRONT TRIES TO
LIFT NORTH. THIS NORTHWARD SHIFT SHOULD RESULT IN MVFR TO VFR
CONDITIONS AT BRL AND MLI...WHILE CID AND DBQ LIKELY LOWER TO IFR.
&&
.HYDROLOGY...
ISSUED AT 357 AM CDT MON APR 28 2014
THE FLOOD WATCH FOR AREA RIVERS AND STREAMS CONTINUES TODAY AND
THIS EVENING. THE THREAT OF FLOODING ON AREA TRIBUTARIES AND THE
MISSISSIPPI RIVER WILL INCREASE AS THE WEEK PROGRESSES WITH A
ACCUMULATIVE EFFECT OF SEVERAL RAIN EVENTS...INCLUDING THIS PAST
SUNDAY EVENING/S HEAVY RAIN...THEN MORE LOCALIZED HEAVY RAIN POSSIBLE
THIS AFTERNOON AND EVENING. LATEST THINKING SUGGESTS WIDESPREAD
RAINFALL AMOUNTS OF 1 TO 4 INCHES WILL FALL OVER MUCH OF THE FORECAST
AREA BY WEDNESDAY...INCLUDING THE RAINFALL FROM YESTERDAY AND LAST
NIGHT. SINCE THE PRECIPITATION WILL OCCUR OVER AN EXTENDED PERIOD OF
TIME...THE THREAT OF FLASH FLOODING WILL BE LOW. HOWEVER...RIVER
FLOODING IS EXPECTED WITH SEVERAL OF THE AREA TRIBUTARIES AND THE
MISSISSIPPI RIVER POSSIBLY SEEING AT LEAST MINOR TO MODERATE FLOODING
BY THE MIDDLE OF THE WEEK.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FLOOD WATCH THROUGH THIS EVENING FOR BENTON-BUCHANAN-CEDAR-
CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-JACKSON-
JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-MUSCATINE-
SCOTT-VAN BUREN-WASHINGTON.
IL...FLOOD WATCH THROUGH THIS EVENING FOR BUREAU-CARROLL-HANCOCK-
HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-PUTNAM-ROCK
ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...FLOOD WATCH THROUGH THIS EVENING FOR CLARK-SCOTLAND.
&&
$$
UPDATE...08
SYNOPSIS...11
SHORT TERM...11
LONG TERM...12
AVIATION...11
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1122 PM EDT TUE APR 29 2014
.UPDATE...
ISSUED AT 1115 PM EDT TUE APR 29 2014
THE GRIDS WERE UPDATED BASED ON RECENT RADAR AND OBSERVATION TRENDS.
THE THREAT OF CONVECTION WILL LINGER ACROSS THE REGION TONIGHT AS A
COLD FRONT WORKS INTO THE REGION. IN ADDITION...THE UPPER LEVEL
TROUGH AXIS WILL REMAIN TO THE WEST OF THE REGION OVERNIGHT WITH
UPPER LEVEL DISTURBANCE ROTATING ACROSS THE LOWER OH VALLEY
OVERNIGHT. THE THREAT FOR SEVERE WEATHER HAS DIMINISHED...BUT IF
STORMS TRAIN OR REDEVELOP...LOCALLY HEAVY RAIN WOULD BE POSSIBLE.
UPDATE ISSUED AT 840 PM EDT TUE APR 29 2014
SHOWER AND THUNDERSTORM ACTIVITY SHOULD BE MOST PREVALENT ALONG THE
WESTERN EDGE OF THE CWA OVER THE NEXT COUPLE OF HOURS...BUT SHORT
TERM MODELS GRADUALLY BRING ACTIVITY EAST. THIS SEEMS REASONABLE. THERE
ARE SEVERAL OUTLFOW BOUNDARIES WORKING ACROSS THE AREA...ONE IS MOVING
THE NORTHWEST ACROSS THE SOUTHWEST COUNTIES AND ANOTHER IS MOVING
EAST OF INTERSTATE 75 OVER THE SOUTHWESTERN CWA. ANOTHER OUTFLOW
BOUNDARY IS MOVING EAST ACROSS THE NORTHERN CWA. THERE IS UNCERTAINTY
AS TO HOW THE INTERACTION OF THESE EVOLVES AND CONVECTION WILL NEED
TO BE WATCHED FOR ANY TRAINING. THE OTHER THREATS FOR THE NEXT COUPLE
OF HOURS APPEARS TO BE MARGINALLY SEVERE HAIL AND DAMAGING WINDS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 340 PM EDT TUE APR 29 2014
18Z SFC ANALYSIS SHOWS OUR NEMESIS OF A BROAD STACKED LOW CENTERED
OVER EASTERN IOWA. EAST KENTUCKY REMAINS IN THE SYSTEM/S SOUPY WARM
SECTOR AS DEWPOINTS ARE STARTING TO COME BACK UP FROM THE MIDDAY
DROPOFF WITH SOME NOW TO NEAR 60 DEGREES IN THE EAST. EXPECT THESE
TO CONTINUE TO COME UP THROUGH THE REST OF THE AFTERNOON.
TEMPERATURES...MEANWHILE...ARE GENERALLY IN THE MID AND UPPER 70S
THROUGH THE AREA. THIS IS ENOUGH FOR SOME SHOWERS AND THUNDERSTORMS
TO DEVELOP OVER THE EAST IN THE WAKE OF THIS MORNING/S BOUNDARY AND
ITS ILL-FATED ATTEMPT TO PULL AWAYS FROM THIS PART OF THE STATE. THIS
BONUS CONVECTION WILL NEED TO BE WATCHED FOR STRONGER DEVELOPMENT
GIVEN THE ENVIRONMENT...BUT THE MAIN THREAT LIKELY ARRIVES FOR EAST
KENTUCKY CLOSER TOWARD SUNSET AND FROM THE SOUTHWEST. WINDS ARE
BREEZY OUT OF THE SOUTHWEST FOR MOST OF THE AREA WITH GUSTS TO 20 KTS
OR SO.
THE MODELS REMAIN IN PRETTY GOOD AGREEMENT ALOFT WITH THE BROAD CUT
OFF LOW SLOWLY TUMBLING NORTHEAST INTO THE GREAT LAKES BY THURSDAY
MORNING. THIS PROCESS WILL INVOLVE A COUPLE OF LINGERING SHORTWAVES
RIDING THE FAST MID LEVEL FLOW BENEATH THE LOW...RUNNING ACROSS
WESTERN KENTUCKY AND THEN NORTHEAST INTO THE OHIO VALLEY. THE FIRST
OF THESE MOVES THROUGH KENTUCKY TOWARD MIDNIGHT WHILE ANOTHER PASSES
BY LATER WEDNESDAY. HAVE FOLLOWED A MODEL BLEND FOR THE FORECAST
WHILE LEANING TOWARD THE HRRR AND NAM12 FOR DETAILS TONIGHT.
SENSIBLE WEATHER WILL FEATURE AN ACTIVE EVENING AND EARLY OVERNIGHT
WITH A DECENT POTENTIAL FOR DAMAGING WIND GUSTS FROM THE STRONGER
STORMS WHILE LARGE HAIL AND AN ISOLATED TORNADO CANNOT BE RULED OUT
SHOULD BE SOME DISCREET CELLS EXHIBIT SUPERCELL CHARACTERISTICS.
HAVE TIMED THESE THROUGH THE CWA MAINLY IN THE EVENING EXPECTING MORE
STABLE AIR TO DEVELOP AFTER 06Z FROM THE EVENING STORMS. HOWEVER...
LOCALIZED HEAVY RAIN WILL REMAIN A CONCERN WHERE ANY STORMS TRAIN.
MORE WIDESPREAD RAINS OVER THE CUMBERLAND VALLEY WILL NEED TO BE
WATCHED CLOSELY AS THE FFG IS THE LOWEST THERE OWING TO THE TWO PLUS
INCHES THAT FELL THERE LAST NIGHT. THERE REMAINS JUST TOO MUCH
UNCERTAINTY TO GO WITH A FLOOD WATCH FOR THIS PART OF THE EAST
KENTUCKY WITH THE GFS KEEPING ITS HEAVIER BAND TO THE NORTHWEST AND
THE NAM PLACING ITS OWN TO THE EAST OF THE LOWER FFG AREAS. WILL
MONITOR THE SITUATION THROUGH THE EVENING FOR A POSSIBLE SHORTER FUSE
WATCH DEPENDING HOW THE STORMS AND ANY TRAINING DEVELOPS.
FOR WEDNESDAY...HAVE INCLUDED A SLIGHT CHANCE OF THUNDER THROUGH NOON
IN THE WEST UNTIL THE LIS GO STRONGLY POSITIVE IN THE AFTERNOON AS
THE SFC WINDS GO WEST AND A COLD FRONT MOVES ON THROUGH. DID DROP
THE THUNDER FURTHER EAST WITH TIME. CARRIED A SMALL CHANCE OF SHOWERS
THROUGH THE EVENING AND INTO THE NIGHT OVER THE EASTERN PARTS OF THE
AREA...BUT RAINFALL AMOUNTS AND CONVECTIVE DEVELOPMENT WILL BE RATHER
PALTRY POST COLD FRONT.
USED THE CONSSHORT...AND THE BC VERSION...AS A STARTING POINT FOR THE
GRIDS THROUGH THE NEXT 24 HOURS WITH THE CONSALL PRELOADED THEREAFTER.
MADE ONLY SOME SMALL ADJUSTMENTS TO THE NUMBERS MAINLY TO CAPTURE THE
CURRENT CONDITIONS AND TRENDS. AS FOR POPS...ENDED UP ON THE HIGH
SIDE OF ALL GUIDANCE TONIGHT AND THROUGH THE FORECAST...CLOSER TO THE
MET NUMBERS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 300 PM EDT TUE APR 29 2014
MODELS REMAIN IN GOOD AGREEMENT WITH THE EVOLUTION OF THE UPPER AIR
PATTERN THROUGH THE END OF THE THE WEEK AND INTO EARLY NEXT WEEK.
THE LARGE UPPER LOW OVER THE UPPER MS VALLEY/UPPER GREAT LAKES AT
THE START OF THE PERIOD WILL MAKES ITS WAY INTO CANADA ON FRIDAY. AFTER
THIS THERE WILL BE OCCASIONAL SHORT WAVE TROUGHS PASSING BY AS A
MEAN LONG WAVE TROUGH REMAINS OVER THE EASTERN PART OF THE U.S. INTO
EARLY NEXT WEEK. ANOTHER UPPER LOW IS FORECAST TO MOVE ACROSS THE
NORTHERN GREAT LAKES LATE IN THE WEEKEND AND INTO NEW ENGLAND BY
EARLY NEXT WEEK.
THE PRIMARY FORECAST CHALLENGE REVOLVES AROUND PRECIPITATION CHANCES
WITH ANY PASSING SHORT WAVES...AND THE PASSAGE OF A WEAK COLD FRONT
THIS WEEKEND. HAVE FOLLOWED A BLENDED MODEL AND INHERITED FORECAST
APPROACH FOR RAIN CHANCES FOR MOST OF THE LONG RANGE PERIOD WHICH
YIELDS VERY LOW PROBABILITIES FOR MAINLY AFTERNOON SHOWERS EACH DAY
FROM THURSDAY THROUGH SUNDAY. WILL NOT MENTION ANY RAIN CHANCE FOR
MONDAY OR TUESDAY BUT LOW RAIN CHANCES MAY NEED TO BE INTRODUCED IN
LATER FORECASTS AS IT APPEARS A WARM FRONT WILL BE MOVING ACROSS THE
AREA. BELOW NORMAL TEMPERATURES WILL PREVAIL THROUGH THE FIRST PART
OF THE FORECAST PERIOD...WITH RISING HEIGHTS EARLY NEXT WEEK LEADING
TO A WARMING TREND AS WE MOVE INTO TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 840 PM EDT TUE APR 29 2014
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO GRADUALLY MOVE BACK ACROSS
THE TAF SITES DURING THE FIRST 6 HOURS OF THE PERIOD. DURING HEAVIER
RAIN IN SHRA AND TSRA AND AS THE ATMOSPHERE GRADUALLY SATURATES IN THE
LOW LEVELS...SOME MVFR TO IFR CONDITIONS ARE ANTICIPATED...AT LEAST
AT TIMES. WINDS WILL BE GENERALLY OUT OF THE SOUTH AND SOUTHWEST
THROUGH THE FIRST PART OF THE FORECAST INCREASING THROUGH THE FIRST
PART OF THE NIGHT WITH GUSTS REACHING UP TO 25 KNOTS. THEY SHOULD
THEN SETTLE SOMEWHAT FROM THE SOUTHWEST TO WEST INTO THE DAY
WEDNESDAY AS CIGS AND VIS IMPROVE...BUT SHOWERS REMAIN AROUND.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...SBH
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
916 PM EDT TUE APR 29 2014
.UPDATE...
ISSUED AT 840 PM EDT TUE APR 29 2014
SHOWER AND THUNDERTORM ACTIIVITY SHOULD BE MOST PREVALENT ALONG THE
WESTERN EDGE OF THE CWA OVER THE NEXT COUPLE OF HOURS...BUT SHORT
TERM MODELS GRADUALLY BRING ACTIVITY EAST. THIS SEEMS REASONABLE. THERE
ARE SEVERAL OUTLFOW BOUNARIES WORKING ACROSS THE AREA...ONE IS MOVING
THE NORTHWEST ACROSS THE SOUTHWESET COUNTIES AND ANOTHER IS MOVING
EAST OF INTERSTATE 75 OVER THE SOUTHWESTERN CWA. ANOTHER OUTFLOW
BOUNARY IS MOVING EAST ACROSS THE NORTHERN CWA. THERE IS UNCERTATINTY
AS TO HOW THE INTERACTION OF THESE EVOLVES AND CONVECTION WILL NEED
TO BE WATCHED FOR ANY TRAINING. THE OTHER THREATS FOR THE NEXT COUPLE
OF HOURS APPEARS TO BE MARGINALLY SEVERE HAIL AND DAMAGING WINDS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 340 PM EDT TUE APR 29 2014
18Z SFC ANALYSIS SHOWS OUR NEMESIS OF A BROAD STACKED LOW CENTERED
OVER EASTERN IOWA. EAST KENTUCKY REMAINS IN THE SYSTEM/S SOUPY WARM
SECTOR AS DEWPOINTS ARE STARTING TO COME BACK UP FROM THE MIDDAY
DROPOFF WITH SOME NOW TO NEAR 60 DEGREES IN THE EAST. EXPECT THESE
TO CONTINUE TO COME UP THROUGH THE REST OF THE AFTERNOON.
TEMPERATURES...MEANWHILE...ARE GENERALLY IN THE MID AND UPPER 70S
THROUGH THE AREA. THIS IS ENOUGH FOR SOME SHOWERS AND THUNDERSTORMS
TO DEVELOP OVER THE EAST IN THE WAKE OF THIS MORNING/S BOUNDARY AND
ITS ILL-FATED ATTEMPT TO PULL AWAYS FROM THIS PART OF THE STATE. THIS
BONUS CONVECTION WILL NEED TO BE WATCHED FOR STRONGER DEVELOPMENT
GIVEN THE ENVIRONMENT...BUT THE MAIN THREAT LIKELY ARRIVES FOR EAST
KENTUCKY CLOSER TOWARD SUNSET AND FROM THE SOUTHWEST. WINDS ARE
BREEZY OUT OF THE SOUTHWEST FOR MOST OF THE AREA WITH GUSTS TO 20 KTS
OR SO.
THE MODELS REMAIN IN PRETTY GOOD AGREEMENT ALOFT WITH THE BROAD CUT
OFF LOW SLOWLY TUMBLING NORTHEAST INTO THE GREAT LAKES BY THURSDAY
MORNING. THIS PROCESS WILL INVOLVE A COUPLE OF LINGERING SHORTWAVES
RIDING THE FAST MID LEVEL FLOW BENEATH THE LOW...RUNNING ACROSS
WESTERN KENTUCKY AND THEN NORTHEAST INTO THE OHIO VALLEY. THE FIRST
OF THESE MOVES THROUGH KENTUCKY TOWARD MIDNIGHT WHILE ANOTHER PASSES
BY LATER WEDNESDAY. HAVE FOLLOWED A MODEL BLEND FOR THE FORECAST
WHILE LEANING TOWARD THE HRRR AND NAM12 FOR DETAILS TONIGHT.
SENSIBLE WEATHER WILL FEATURE AN ACTIVE EVENING AND EARLY OVERNIGHT
WITH A DECENT POTENTIAL FOR DAMAGING WIND GUSTS FROM THE STRONGER
STORMS WHILE LARGE HAIL AND AN ISOLATED TORNADO CANNOT BE RULED OUT
SHOULD BE SOME DISCREET CELLS EXHIBIT SUPERCELL CHARACTERISTICS.
HAVE TIMED THESE THROUGH THE CWA MAINLY IN THE EVENING EXPECTING MORE
STABLE AIR TO DEVELOP AFTER 06Z FROM THE EVENING STORMS. HOWEVER...
LOCALIZED HEAVY RAIN WILL REMAIN A CONCERN WHERE ANY STORMS TRAIN.
MORE WIDESPREAD RAINS OVER THE CUMBERLAND VALLEY WILL NEED TO BE
WATCHED CLOSELY AS THE FFG IS THE LOWEST THERE OWING TO THE TWO PLUS
INCHES THAT FELL THERE LAST NIGHT. THERE REMAINS JUST TOO MUCH
UNCERTAINTY TO GO WITH A FLOOD WATCH FOR THIS PART OF THE EAST
KENTUCKY WITH THE GFS KEEPING ITS HEAVIER BAND TO THE NORTHWEST AND
THE NAM PLACING ITS OWN TO THE EAST OF THE LOWER FFG AREAS. WILL
MONITOR THE SITUATION THROUGH THE EVENING FOR A POSSIBLE SHORTER FUSE
WATCH DEPENDING HOW THE STORMS AND ANY TRAINING DEVELOPS.
FOR WEDNESDAY...HAVE INCLUDED A SLIGHT CHANCE OF THUNDER THROUGH NOON
IN THE WEST UNTIL THE LIS GO STRONGLY POSITIVE IN THE AFTERNOON AS
THE SFC WINDS GO WEST AND A COLD FRONT MOVES ON THROUGH. DID DROP
THE THUNDER FURTHER EAST WITH TIME. CARRIED A SMALL CHANCE OF SHOWERS
THROUGH THE EVENING AND INTO THE NIGHT OVER THE EASTERN PARTS OF THE
AREA...BUT RAINFALL AMOUNTS AND CONVECTIVE DEVELOPMENT WILL BE RATHER
PALTRY POST COLD FRONT.
USED THE CONSSHORT...AND THE BC VERSION...AS A STARTING POINT FOR THE
GRIDS THROUGH THE NEXT 24 HOURS WITH THE CONSALL PRELOADED THEREAFTER.
MADE ONLY SOME SMALL ADJUSTMENTS TO THE NUMBERS MAINLY TO CAPTURE THE
CURRENT CONDITIONS AND TRENDS. AS FOR POPS...ENDED UP ON THE HIGH
SIDE OF ALL GUIDANCE TONIGHT AND THROUGH THE FORECAST...CLOSER TO THE
MET NUMBERS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 300 PM EDT TUE APR 29 2014
MODELS REMAIN IN GOOD AGREEMENT WITH THE EVOLUTION OF THE UPPER AIR
PATTERN THROUGH THE END OF THE THE WEEK AND INTO EARLY NEXT WEEK.
THE LARGE UPPER LOW OVER THE UPPER MS VALLEY/UPPER GREAT LAKES AT
THE START OF THE PERIOD WILL MAKES ITS WAY INTO CANADA ON FRIDAY. AFTER
THIS THERE WILL BE OCCASIONAL SHORT WAVE TROUGHS PASSING BY AS A
MEAN LONG WAVE TROUGH REMAINS OVER THE EASTERN PART OF THE U.S. INTO
EARLY NEXT WEEK. ANOTHER UPPER LOW IS FORECAST TO MOVE ACROSS THE
NORTHERN GREAT LAKES LATE IN THE WEEKEND AND INTO NEW ENGLAND BY
EARLY NEXT WEEK.
THE PRIMARY FORECAST CHALLENGE REVOLVES AROUND PRECIPITATION CHANCES
WITH ANY PASSING SHORT WAVES...AND THE PASSAGE OF A WEAK COLD FRONT
THIS WEEKEND. HAVE FOLLOWED A BLENDED MODEL AND INHERITED FORECAST
APPROACH FOR RAIN CHANCES FOR MOST OF THE LONG RANGE PERIOD WHICH
YIELDS VERY LOW PROBABILITIES FOR MAINLY AFTERNOON SHOWERS EACH DAY
FROM THURSDAY THROUGH SUNDAY. WILL NOT MENTION ANY RAIN CHANCE FOR
MONDAY OR TUESDAY BUT LOW RAIN CHANCES MAY NEED TO BE INTRODUCED IN
LATER FORECASTS AS IT APPEARS A WARM FRONT WILL BE MOVING ACROSS THE
AREA. BELOW NORMAL TEMPERATURES WILL PREVAIL THROUGH THE FIRST PART
OF THE FORECAST PERIOD...WITH RISING HEIGHTS EARLY NEXT WEEK LEADING
TO A WARMING TREND AS WE MOVE INTO TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 840 PM EDT TUE APR 29 2014
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO GRADUALLY MOVE BACK ACROSS
THE TAF SITES DURING THE FIRST 6 HOURS OF THE PERIOD. DURING HEAVIER
RAIN IN SHRA AND TSRA AND AS THE ATMOSPHERE GRADUALLY SATURATES IN THE
LOW LEVELS...SOME MVFR TO IFR CONDITIONS ARE ANTICIPATED...AT LEAST
AT TIMES. WINDS WILL BE GENERALLY OUT OF THE SOUTH AND SOUTHWEST
THROUGH THE FIRST PART OF THE FORECAST INCREASING THROUGH THE FIRST
PART OF THE NIGHT WITH GUSTS REACHING UP TO 25 KNOTS. THEY SHOULD
THEN SETTLE SOMEWHAT FROM THE SOUTHWEST TO WEST INTO THE DAY
WEDNESDAY AS CIGS AND VIS IMPROVE...BUT SHOWERS REMAIN AROUND.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...SBH
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
425 PM EDT MON APR 28 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 425 PM EDT MON APR 28 2014
19Z SFC ANALYSIS SHOWS THE DEEP AREA OF LOW PRESSURE SPINNING OVER THE
CENTRAL PLAINS. THIS SYSTEM/S WARM FRONT IS LAID OUT TO THE EAST JUST
NORTH OF THE OHIO RIVER. THIS PLACES EAST KENTUCKY WELL INTO TO THE
BROAD WARM SECTOR AND THUS RIPE FOR PERIODS OF SHOWERS AND
THUNDERSTORMS. EARLIER SUNSHINE IN THE FAR EAST LED TO WARMER
TEMPERATURES AND THIS IS HELPING STORMS SUSTAIN THEMSELVES NEAR THE
VIRGINIA BORDER. MEANWHILE...MUCH COOLER TEMPERATURES IN THE REST OF
THE CWA...DUE TO THE COLD POOL FROM THE EARLIER MCS TO THE WEST AND
MORE EXTENSIVE CLOUD COVER...HAS KEPT THE CONVECTION TAME THERE...FOR
NOW. DEWPOINTS REMAIN IN THE UPPER 50S TO LOWER 60S THROUGHOUT THE
AREA WHILE THE WINDS ARE RATHER VARIABLE WITH OCCASIONAL SOUTH TO
SOUTHWEST GUSTS TO 20 KTS...OUTSIDE OF STORMS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE DEEP UPPER LOW
TRANSITIONING INTO THE MID MISSISSIPPI VALLEY TONIGHT AND SPREADING
WAVES OF ENERGY CLUSTERS OVER EAST KENTUCKY AS IT DOES SO. THE BROAD
CLOSED LOW THEN LIFTS NORTH INTO THE WESTERN GREAT LAKES LATER
TUESDAY WHILE ONE LAST BATCH OF ENERGY RIDES THROUGH KENTUCKY DURING
THE NIGHT. GIVEN THE MODEL AGREEMENT...HAVE FOLLOWED A BLEND WITH A
LEAN TOWARD THE NAM12 AND HRRR FOR THE NEAR TERM DETAILS.
SENSIBLE WEATHER WILL FEATURE PERIODS OF SHOWERS AND THUNDERSTORMS
THROUGH THE SHORT TERM PORTION OF THE FORECAST. EACH NEW CLUSTER WILL
HAVE A CHANCE TO BECOME SEVERE DEPENDING ON THE INSTABILITY LEFT
BEHIND BY EARLIER STORMS AND CLEARING THAT CAN TAKE PLACE DURING THE
DAYLIGHT HOURS. THIS WAS WHAT SET UP THE STORMS FOR FAR EAST KENTUCKY
THIS AFTERNOON. EXPECT THESE TO CLEAR OUT OVER THE NEXT HOUR OR SO.
ABOUT THAT TIME...THE NEXT ROUND OF STORMS SHOULD BE DEVELOPING IN
SOUTH CENTRAL KENTUCKY AND WORKING TO MOVE NORTHEAST INTO EAST
KENTUCKY LATER IN THE EVENING. STORMS WILL CONTINUE THROUGH THE NIGHT
AS THE SET UP REMAINS INTACT. THE ACTUAL COVERAGE AND TIMING OF
THESE LATER EVENTS WILL BE PARTIALLY DEPENDENT ON THE EARLIER
EVOLUTION SO IT BECOMES HARDER TO PIN POINT. DO EXPECT THIS OVERNIGHT
WAVE OF STORMS TO MOVE ON THROUGH TOWARDS DAWN AND EARLY TUESDAY
MORNING IN FAR EASTERN PARTS OF THE STATE. ISOLATED TRAINING AND
HEAVY RAINS WILL BE POSSIBLE THROUGH THE NIGHT...POSSIBLY RESULTING
IN A FLASH FLOOD THREAT. THIS WILL CONTINUE TO BE HIGHLIGHTED IN THE
HWO AND SPS. AFTER A MIDDAY LULL ON TUESDAY...LOW TOPPED STORMS
SHOULD DEVELOP ACROSS EAST KENTUCKY BY LATE AFTERNOON WITH A
CONTINUING POTENTIAL TO BE SEVERE...INCLUDING A SLIGHT TORNADO THREAT
DUE TO FAVORABLE WIND SHEAR IN THE LOW LEVELS. THE MORE SUNSHINE THAT
MANAGES TO OCCUR DURING THE DAY TUESDAY WILL PLAY INTO HOW STRONG THE
STORMS COULD BECOME. THE SYSTEM/S COLD FRONT WILL SWEEP THROUGH LATER
THAT NIGHT AND SHOULD END THE RISK FOR SEVERE WEATHER AND ALSO WIND
DOWN THE THUNDER CHANCES.
USED THE CONSSHORT AS A STARTING POINT FOR THE GRIDS THROUGH THE NEXT
24 HOURS WITH THE CONSALL THEREAFTER. MADE ONLY MINOR ADJUSTMENTS TO
THE NUMBERS MAINLY TO CAPTURE THE CURRENT CONDITIONS AND TRENDS. AS
FOR POPS...ENDED UP ON THE HIGH SIDE OF ALL GUIDANCE THROUGH THE
FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 PM EDT MON APR 28 2014
MODELS REMAIN IN GOOD AGREEMENT WITH THE EVOLUTION OF THE UPPER AIR
PATTERN THROUGH THE MIDDLE AND END OF THE WEEK. THE LARGE UPPER LOW
OVER THE UPPER MS VALLEY WILL MAKES ITS WAY INTO THE GREAT LAKES
REGION BY THURSDAY...AND THEN ON INTO CANADA BY FRIDAY. AFTER THIS
THERE WILL BE OCCASIONAL SHORT WAVE TROUGHS PASSING BY AS A MEAN
LONG WAVE TROUGH REMAINS OVER THE EASTERN PART OF THE U.S. INTO
EARLY NEXT WEEK. IT DOES APPEAR THE FLOW WILL BE SLOWLY DEAMPLIFYING
THOUGH.
HIGHER RAIN AND THUNDERSTORMS CHANCES WILL LINGER INTO THE DAY
WEDNESDAY...MAINLY IN THE EASTERN PART OF THE FORECAST AREA. THE
DEEPER MOISTURE AND FORCING WILL BE EXITING THE AREA ON
WEDNESDAY...BUT MAINLY DIURNAL SHOWER CHANCES WILL LINGER INTO THE
WEEKEND. WITH A MEAN TROUGH OVER THE AREA TEMPERATURES WILL ALSO
AVERAGE BELOW NORMAL FOR THE END OF THE WEEK AND INTO THE WEEKEND.
TEMPERATURES WILL BE WARMING LATE IN THE WEEKEND AND INTO EARLY NEXT
WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 215 PM EDT MON APR 28 2014
VFR CONDITIONS WILL CONTINUE FOR MUCH OF THE AREA THIS AFTERNOON...
OUTSIDE OF A ZONE OF STRONGER STORMS FOR THE NEXT FEW HOURS LOCATED
SOUTH AND EAST OF THE TAF SITES. THE NEXT STRONG TO SEVERE CLUSTER OF
SHOWERS AND STORMS MOVE IN AROUND 00Z. HAVE GONE WITH MVFR TO IFR
CEILINGS AND VISIBILITY THROUGH MUCH OF THE NIGHT AND INTO EARLY
TUESDAY MORNING WITH THIS OVERNIGHT ROUND OR TWO OF STORMS.
CONDITIONS IMPROVE TEMPORARILY INTO MIDDAY TUESDAY WITH VFR CIGS
AND VIS EXPECTED FOR A TIME. WINDS WILL BE OUT OF THE SOUTH FOR MUCH
OF THE PERIOD WITH GUSTS UP TO 20 KTS POSSIBLE...OUTSIDE OF
THUNDERSTORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...SBH
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
152 AM EDT MON APR 28 2014
.UPDATE...
ISSUED AT 151 AM EDT MON APR 28 2014
CURRENTLY ACROSS EASTERN KENTUCKY...A LINE OF SHOWERS HAS MOVED
NORTHEAST THROUGH THE AREA ALONG THE WARM FRONT. BEHIND
THIS...ANOTHER LINE OF SHOWERS IS STARTING TO DEVELOP AS IT SLIDES
EAST AND EAST NORTHEAST THROUGH THE AREA. IT SEEMS A BIT MORE
INSTABILITY IS PRESENT WITH THIS AND UPSTREAM IN TN...SOME INDICATION
OF MORE MOIST AND UNSTABLE AIR IS STARTING TO STREAM NORTH. WITH ALL
THIS IN MIND...HAVE UPDATED THE FORECAST AND SENT OUT A ZFP TO BRING
IN POPS A BIT EARLIER AND BRING LIKELY POPS IN BY THE MORNING AS THE
ANTICIPATED FIRST WAVE BEHINDS TO PUSH NORTHEAST.
UPDATE ISSUED AT 1030 PM EDT SUN APR 27 2014
AS EXPECTED...EARLIER THUNDERSTORMS HAVE WEAKENED WITH JUST SOME
WIDELY ISOLATED SHOWERS PUSHING ACROSS THE AREA WITH THE WARM FRONT.
THIS ACTIVITY WILL CONTINUE TO PUSH NORTHWARD OVER THE NEXT 3 TO 5
HOURS...WITH DRIER WEATHER RETURNING THROUGH THE LATTER HALF OF THE
NIGHT. HOWEVER...PLENTY OF SHOWERS AND THUNDERSTORMS UPSTREAM ACROSS
ARKANSAS AND FAR WESTERN KENTUCKY. SOME OF THIS MAY CONGEAL INTO AN
MCS AND TRACK TOWARDS THE AREA TOMORROW MORNING. THIS COULD BRING THE
THREAT OF DAMP WEATHER BACK TO THE AREA AROUND OR SHORTLY AFTER
DAYBREAK. AT THIS TIME...IT DOES NOT APPEAR THIS ACTIVITY WILL POSE A
SEVERE RISK AS SURFACE INSTABILITY WILL BE AT A MINIMUM EARLY IN THE
MORNING. IT LOOKING MORE LIKE WE MAY HAVE MORE OF A SEVERE THREAT
ARRIVING MONDAY EVENING OR MONDAY NIGHT AS WE MAY SEE AN MCS MOVE
INTO THE AREA INTO THE OVERNIGHT TIME PERIOD. THUS...SEVERE THREAT
APPEARS TO BE PUSHED BACK INTO MONDAY EVENING OR MONDAY NIGHT.
UPDATE ISSUED AT 745 PM EDT SUN APR 27 2014
A FEW SHOWERS AND STORMS BEGINNING TO ENCROACH UPON EASTERN KENTUCKY.
THE FIRST ONE IS JUST GRAZING THE WESTERN EDGE OF WAYNE COUNTY AS IT
MOVES NORTHWARD...WITH A SECONDARY AREA MOVING INTO SOUTHERN
BELL/WHITLEY COUNTIES. NOT MUCH OTHER ACTIVITY ON RADAR AT PRESENT
TIME. WITH MORE OF A STRATIFORM LIGHT RAIN DEVELOPING FARTHER TO THE
SOUTHWEST ACROSS NORTH CENTRAL TENNESSEE. STILL PLENTY OF DRY AIR IN
PLACE ACROSS EASTERN KENTUCKY WHICH WILL LIKELY PUT THE END TO ANY
STORM CHANCES AS STUFF TRIES TO PUSH INTO THE AREA. THUS...WITH SUN
SETTING...WE WILL BE LOSING ANY INSTABILITY WE HAVE OUT THERE WITH
THUNDERSTORMS DIMINISHING TOWARDS SHOWERS. EVEN THE SHOWERS WILL HAVE
A TOUGH TIME SURVIVING AS THEY MOVE INTO THE DRIER AIR IN THE EAST.
THUS...HAVE BACKED OFF POPS THIS EVENING INTO THE OVERNIGHT HOURS.
ALSO BACKED OFF THUNDER CHANCES AFTER THE NEXT HOUR OR SO. NEXT ROUND
OF SHOWERS AND THUNDERSTORMS REMAIN OUT ACROSS WESTERN TENNESSEE AND
WESTERN KENTUCKY AND IF IT HOLDS TOGETHER...WOULD NOT BE INTO THE
AREA UNTIL AFTER MIDNIGHT. UPDATED FORECAST IS ALREADY OUT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 355 PM EDT SUN APR 27 2014
STARTING INTO AN ACTIVE PERIOD DURING THE SHORT TERM. A SURFACE LOW
PRESSURE SYSTEM WILL REMAIN OVER THE CENTRAL PLAINS THIS
EVENING...WHILE SEVERAL WAVES OF ENERGY WILL CONTINUE TO ROTATE
AROUND THIS SYSTEM. EASTERN KY WILL REMAIN IN THE WARM SECTOR...WITH
A WARM FRONT POSITIONED ACROSS MUCH OF THE STATE.
MEANWHILE...WESTERN AND CENTRAL KY WILL FIND THEMSELVES POSITIONED
BETWEEN THE WARM FRONT AND COLD FRONT...WITH WARM UNSTABLE AIR
CONTINUING TO FILTER IN AND ABUNDANT MOISTURE TO ACCOMPANY.
WHILE NOT MUCH PROGRESSION IS EXPECTED THIS AFTERNOON OR TONIGHT IN
TERMS OF THE SURFACE LOW AND THE ASSOCIATED FRONTS...THE INCREASED
INSTABILITY DURING THE AFTERNOON WILL WORK TO HELP ANY CONVECTIVE
DEVELOPMENT TO SPREAD EASTWARD SLOWLY. LATEST HIRES
MODELS...INCLUDING THE NAM12/HRRR/AND ECMWF ALL POINT AT PRECIP
ENTERING INTO EASTERN KY BETWEEN 0 AND 6Z AND THEN CONTINUING
EASTWARD THROUGHOUT THE NIGHT. IT IS ALSO AROUND THIS POINT THAT
GFS40 AND NAM12 FORECAST SOUNDINGS SHOW SOME IMPRESSIVE LOW LEVEL
SHEER IN PORTIONS OF EASTERN KY. WHILE LINGERING DRY LOW LEVEL AIR
AND SE DOWNSLOPE WINDS COULD WORK TO HOLD OFF SOME PRECIP IN THE
EVENING...EXPECT THAT ISOLATED TO SCATTERED SHOWERS WILL DEVELOP. IN
DOING SO...MOISTENING OF THE LOW LEVELS WILL BE ENOUGH TO ALLOW
UNSTABLE AIR TO RISE AND THUNDERSTORMS TO DEVELOP. IN
ADDITION...BASED ON STRONG STORMS THAT HAVE DEVELOPED
UPSTREAM...HAVE KEPT THUNDER AS THE PREDOMINATE WX TYPE THIS EVENING
AND THROUGH THE NIGHT.
BETWEEN 3Z AND 12Z MONDAY...CHANCE POPS WILL OVERSPREAD THE AREA.
HOWEVER...LATEST HI-RES GUIDANCE IS POINTING AT A DRY POCKET
DEVELOPING AS DOWNSLOPE FLOW INCREASES SLIGHTLY ACROSS THE SOUTHEAST
PORTION OF THE STATE. LATEST RUC13 OMEGA IS ALSO SUPPORTIVE OF THIS
IDEA...SHOWING DOWNWARD MOTION ACROSS THE SE PORTION OF THE STATE BY
9Z. THE QUESTION THEN WILL BE...HOW MUCH WILL THIS DOWNSLOPING
INHIBIT ANY STORM DEVELOPMENT? HOW FAR INTO EASTERN KY COULD IT
POTENTIALLY INHIBIT STORM GROWTH AND RAIN...AND WILL WE STILL EXPECT
SOME ISOLATED TO SCATTERED CHANCES...OR WILL DOWNSLOPE CUT OFF
POTENTIAL ALL TOGETHER? UNFORTUNATELY...THESE ARE ALL QUESTIONS
WHICH CAN/T REALLY BE ANSWERED UNTIL THE MAIN CONVECTION REACHES OUR
AREA. UNTIL THEN...WILL TRY TO PLAY ON THIS THINKING...AND TREND
DOWN POPS SLIGHTLY FOR THE SE PORTION OF THE CWA.
DURING THE DAY TOMORROW...SURFACE LOW WILL HAVE PROGRESSED ONLY
SLIGHTLY EASTWARD...THOUGH THE SURFACE COLD FRONT WILL HAVE ENTERED
INTO THE MISSISSIPPI VALLEY REGION. WITH THE FORCING SO GREAT IN
PROXIMITY TO THIS FRONT...AND A STRONG PULL OF GULF
MOISTURE...EXPECT SHOWERS/TSRA TO OVERCOME THE DOWNSLOPING PULL.
ESPECIALLY IF WINDS SHIFT MORE SOUTHERLY FOR A PERIOD OF
TIME...COULD SEE MORE WIDESPREAD DEVELOPMENT ACROSS THIS AREA.
UNFORTUNATELY...EVEN THE HI-RES MODELS ARE SHOWING SOME DISAGREEMENT
ON THE EXTENT AND MAGNITUDE OF PRECIP FOR TOMORROW...SO HAVE TRIED
TO STICK TO A BLEND. Q VECTORS ARE SHOWING THE BEST AREAS FOR UPWARD
MOTION AND STORM DEVELOPMENT REMAINING JUST TO OUR NORTH
TOMORROW...MAINLY OVER THE UPPER GREAT LAKES REGION. SOME DECENT
CONVERGENCE DOES MAKE IT INTO KY AS WELL...MOVING FROM WEST TO EAST
ACROSS THE STATE. AS IT HEADS INTO EASTERN KY...EVEN THE QVECTOR
CONVERGENCE PICKS UP ON A BRIEF LULL IN ACTIVITY ACROSS THE SE
PORTION OF THE STATE WITH DOWNSLOPE WINDS IN PLACE. THIS QUICKLY
DISAPPEARS AS THE BEST CONVERGENCE MOVES OVER THE REGION...SO
FURTHER SUPPORT THAT AT SOME POINT THE MOISTURE WILL BE ENOUGH TO
OVERCOME ANY EFFECTS FROM THE WIND DIRECTION. LOW LEVEL WIND SHEAR
DURING THE DAY TOMORROW ISN/T QUITE AS IMPRESSIVE AS THAT EXPECTED
THIS EVENING...BUT IT SEEMS TO BE A BIT DEEPER. WINDS IN THE UPPER
LEVELS ARE QUITE STRONG...SO EXPECT A GOOD DRIVING FORCE AND THE
POTENTIAL FOR A LINE OF SHOWERS/STORMS TO TRAVERSE KY /AS WAS
REFLECTED IN THE MONDAY EVENING/MONDAY NIGHT POPS AND WEATHER/.
MONDAY NIGHT/S LINE OF STORMS IS ALSO EXPECTED TO BRING THE BEST
THREAT FOR HEAVY PRECIP DURING THE SHORT TERM ACCORDING TO THE LAST
FEW MODEL RUNS. AFTER ROUND ONE OF PRECIP MOVES IN TONIGHT AND
TOMORROW...A STRONGER SECOND LINE WILL DEVELOP CLOSER TO THE FRONT.
MOISTURE GETTING PULLED IN WILL ALLOW FOR 6 HOUR QPF AMOUNTS WELL IN
THE 1 TO 3 INCH RANGE BY 6Z TUESDAY...TRAVERSING EASTERN KY DURING
THIS TIME. WITH THIS AMOUNT OF EXPECTED CONVECTIVE RAIN...AND THE
CONTINUED POTENTIAL FOR SOME THUNDERSTORMS PRODUCING HEAVY SHOWERS
OVER SMALL AREAS...THERE DOES LIE THE THREAT OF FLOODING ACROSS
PORTIONS OF THE STATE...INCLUDING EASTERN KY. WINDS ALOFT ARE QUITE
IMPRESSIVE AS THIS LINE MOVES OVER...SO ANY STORMS OR HEAVY RAIN
SHOWERS BRING THE THREAT OF TRANSFERRING SOME OF THESE POTENTIALLY
DAMAGING WINDS TO THE GROUND. AS FAR AS THE FLOODING...WILL
PROBABLY NEED TO ISSUE A WATCH AT SOME POINT IN THE NEAR FUTURE.
ELECTED NOT TO DURING THE DAY SHIFT JUST FOR THE SHEER FACT THAT THE
MODELS ARE STILL HAVING A HARD TIME AGREEING...AND REALLY ITS GOING
TO BE A MATTER OF HOW MUCH PRECIP WE END UP RECEIVING OVERNIGHT
TONIGHT AND TOMORROW MORNING TO KNOW HOW SATURATED THE SOIL WILL BE
LEADING INTO THE EVENING. WILL MENTION CONCERNS TO INCOMING SHIFT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 425 PM EDT SUN APR 27 2014
THE MODELS CONTINUE TO BE IN GOOD AGREEMENT ALOFT WITH THE LARGE AND
LUMBERING CLOSED LOW OVER THE MID SECTION OF THE NATION AT THE START
OF THE EXTENDED. THIS DOMINANT FEATURE ROLLS OVER ON ITSELF AS IT
SLOWLY FILLS AND LIFTS NORTH INTO THE UPPER MIDWEST AND WESTERN
GREAT LAKES BY 00Z THURSDAY. THE SYSTEM BECOMES MORE PROGRESSIVE
TOWARD THE END OF THE WEEK...EVENTUALLY EXITING INTO EASTERN CANADA.
BEFORE IT DOES SO...A CONTINUATION OF A SERIES OF MID LEVEL ENERGY
PACKETS WILL PLOW THROUGH KENTUCKY BRINGING PERIODIC SUPPORT TO
CONVECTION THROUGHOUT THE REGION. FOR TUESDAY...A KEY ONE OF THESE
PACKETS MOVES OVER EAST KENTUCKY EARLY FOLLOWED BY ANOTHER LATE IN
THE DAY AND INTO EARLY WEDNESDAY. THESE PACKETS DO WEAKEN WITH TIME
SO THAT THE VERSION THAT GOES THROUGH ON MIDDAY WEDNESDAY WILL
LIKELY NOT PACK THE PUNCH OF THE EARLIER ONES. FALLING HEIGHTS
LOCALLY WILL BE NOTED INTO THURSDAY MORNING EVEN AS THE MAIN LOW TO
THE NORTH WEAKENS BUT BY THIS TIME THE ENERGY SWIRLING PAST WILL BE
SIMILARLY WEAKER. IT IS ALSO ABOUT THIS TIME THAT THE AGREEMENT OF
THE GEM WITH THE NEARLY LOCKSTEP ECMWF AND GFS AT MID LEVELS FADES
AND ITS SOLUTION IS SUBSEQUENTLY DISCOUNTED. THE OTHER MODELS
CONTINUE TO MAINTAIN LOWER THAN NORMAL 500MB HEIGHTS OVER EAST
KENTUCKY INTO THE WEEKEND DUE TO THE ARRIVAL OF ANOTHER...MORE
PROGRESSIVE AND OPEN...TROUGH FROM THE PLAINS. THE GFS IS A BIT
BETTER CONSOLIDATED WITH THIS THAN THE ECMWF AS IT TAKES ITS AXIS
THROUGH EAST KENTUCKY EARLY SATURDAY WHILE THE ECMWF SNEAKS A LEAD
WAVE THROUGH ON FRIDAY WITH THE REST OF THE SYSTEM PASSING THROUGH
LATER SATURDAY. HEIGHTS WILL THEN TICK UP IN THE WAKE OF THIS ACTION
TO CLOSE OUT THE WEEKEND ON A WELCOMED QUIETER NOTE. FOR THE
FORECAST HAVE FOLLOWED A GENERAL MODEL BLEND THROUGH THE REST OF THE
WORK WEEK WITH A SLIGHT PREFERENCE FOR THE LATEST ECMWF THEREAFTER.
SENSIBLE WEATHER WILL FEATURE AT LEAST ONE LAST STORMY DAY AND NIGHT
TO START THE EXTENDED. THE EXPECTATION IS THAT AN ONGOING CLUSTER OF
STORMS WILL BE MOVING OUT OF EASTERN KENTUCKY AT 12Z TUESDAY.
HOWEVER...THE NEXT SURGE OF LIFT ASSOCIATED WITH THE MID LEVEL WAVE
ROLLING INTO THE AREA LATER THAT DAY WILL START TO ACT ON THE
ENVIRONMENT OF EAST KENTUCKY DURING THE AFTERNOON. THIS WILL COMBINE
WITH THE MOIST BOUNDARY LAYER...HEATING THROUGH THE DAY...TO
GENERATE DECENT INSTABILITY LIKELY KICKING OFF ANOTHER CONVECTIVE
CLUSTER. WITH THE VEERING SHEAR PROFILE AND POTENTIAL FOR HIGHER
INSTABILITY BY EVENING TUESDAY...WILL CONTINUE THE THREAT OF STRONG
TO SEVERE STORMS. THESE STORMS MAY LINGER INTO THE NIGHT BEFORE
CLEARING OUT TO THE EAST ALONG WITH THE SYSTEM/S SLOW MOVING COLD
FRONT FINALLY PUSHING OUT OF THE AREA. THE NEARBY FRONT AND LOW MID
LEVEL HEIGHTS SHOULD LEAVE WEDNESDAY WITH A POTENTIAL FOR RENEWED
CONVECTION...THOUGH THE THUNDER THREAT WILL PROBABLY BE LIMITED TO
THE FAR EAST AND MAINLY EARLIER IN THE DAY. THE THREAT OF SHOWERS
WILL THEN CONTINUE THROUGH THE REST OF THE WORK WEEK AND INTO THE
FIRST PART OF THE WEEKEND WHILE LIMITED INSTABILITY AND COOLER
TEMPERATURES KEEP THE THREAT OF THUNDER TO A MINIMUM. HAVE GONE WITH
DRY WEATHER FOR SUNDAY AS HIGH PRESSURE SHOULD BE MOVING OVERHEAD.
TEMPERATURES WILL BE DEFINITELY ON THE COOL SIDE OF NORMAL FOR THE
BULK OF THE EXTENDED IN THE WAKE OF THE SYSTEM/S SLOW MOVING COLD
FRONT PASSING THROUGH ON WEDNESDAY. TUESDAY REMAINS THE MOST
CHALLENGING DAY FOR MAX TEMPERATURES DUE TO QUESTIONS OF CLEARING
BEHIND THE DEPARTING EARLY MORNING BATCH OF CONVECTION. MORE...AND
QUICKER...CLEARING WILL ALLOW TEMPERATURES TO SOAR INTO THE UPPER
70S AND ALSO SPIKE THE INSTABILITY MAKING FOR A BETTER POTENTIAL FOR
SEVERE WEATHER. HOWEVER...THERE IS A POTENTIAL FOR CONVECTIVE DEBRIS
AND LINGERING LOW CLOUDS/SHOWERS TO KEEP TEMPERATURES CAPPED AND
INSTABILITY/SVR POTENTIAL MORE LIMITED.
THE CR GRID LOAD CAME IN PRETTY GOOD FOR THE BULK OF THE EXTENDED...
THOUGH DID MAKE SOME ADJUSTMENTS TOWARD THE LATEST ECMWF SOLUTION
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND...PARTICULARLY FOR
A DRY SUNDAY. DID ALSO FINE TUNE SOME LOW TEMP GRIDS LATER IN THE
FORECAST TO ALLOW FOR SOME ENHANCED RIDGE AND VALLEY DETAIL OVER THE
WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 151 AM EDT MON APR 28 2014
VFR CONDITIONS WILL BEGIN THE TAF PERIOD THROUGH THE LATE TONIGHT
HOURS. BY THE MORNING...SHOWERS AND THUNDERSTORMS WILL BEGIN TO MOVE
INTO THE WESTERN CWA WITH A LINE PUSHING THROUGH THE TAF SITES AND
HAVE PUT IN SOME MVFR CONDITIONS THROUGH THE 12Z TO 16Z RANGE MAINLY
DUE TO VISIBILITY IN THE SLIGHTLY HEAVIER SHOWERS. WILL THEN SHOW
SOME VFR TOMORROW AFTERNOON BEFORE THE NEXT STRONG TO SEVERE LINE OF
SHOWERS AND STORMS MOVE IN BY THE LAST 6 HOURS OF THE TAF PERIOD AND
HAVE GONE IFR DURING THIS PERIOD. WINDS WILL BE OUT OF THE SOUTH FOR
MUCH OF THE PERIOD WITH GUSTS UP TO 20 KNOT OUTSIDE OF THUNDERSTORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...JMW
LONG TERM...GREIF
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1155 PM CDT SUN APR 27 2014
.DISCUSSION...
FOR 06Z TAFS...IFR CONDITIONS STARTING TO MOVE INTO WESTERN
AREA...WILL STAY THAT WAY THROUGH THE OVERNIGHT HOURS. MVFR
ELSEWHERE IS EXPECTED THROUGH THE MORNING. STILL NOT CERTAIN ON
HOW MUCH...IF ANY PRECIP WILL OCCUR AT SOUTHERN TAF SITES SO STILL
HOLDING OFF ON MENTIONING IT...BUT MAY NEED TO BE ADDED FOR THE
MORNING HOURS. WILL BE CARRYING A TEMPO GROUP FOR THUNDERSTORMS AT
KAEX IN THE MORNING HOURS.
&&
.PREV DISCUSSION... /ISSUED 943 PM CDT SUN APR 27 2014/
DISCUSSION...
UPDATED THE AREAL DISTRIBUTION OF POPS TO MORE CLOSELY FOLLOW THE
HRR (HIGH RESOLUTION RAPID REFRESH) SOLUTION. OTHERWISE...THE
ZONE PACKAGE IS ON TARGET.
JT
PREV DISCUSSION... /ISSUED 630 PM CDT SUN APR 27 2014/
DISCUSSION...
FOR 00Z TAFS...VFR TO MVFR CONDITIONS EXPECTED THIS EVENING...WITH
GUSTY SOUTH WINDS. NOT EXPECTING THE NEXT ROUND OF PRECIP UNTIL
TOWARDS DAYBREAK...BUT LOW CONFIDENCE ON COVERAGE AT THIS POINT.
PREV DISCUSSION... /ISSUED 436 PM CDT SUN APR 27 2014/
DISCUSSION...
LATEST WATER VAPOR SATELLITE IMAGERY SHOWED A VIGOROUS UPPER LOW
OVER NW KS/SW NE...WITH A VIGOROUS PACIFIC JET NOSING IN FROM THE
PAC NW AND CURLING CYCLONICALLY THROUGH THE BASE OF THE LOW. A
SUBTROPICAL JET WAS NOTED TO THE SOUTH ACROSS CENTRAL MX INTO THE
WRN GULF. KLCH AND KPOE VWPS CONTINUE TO SHOW A 50KT PLUS
SOUTHWESTERLY LLJ.
AT THE SFC...LOW PRESSURE IS HARD TO MISS OVER NW KS...WITH A
TRAILING CDFNT/DRYLINE THROUGH CENTRAL OK/TX.
HARD TO HAVE A GREAT DEAL OF FAITH IN ANY SPECIFIC SHORT TERM
GUIDANCE...AS PRECIOUS FEW CAUGHT THE ISOLATED TO SCATTERED
ELEVATED CONVECTION THAT DEVELOPED THIS AFTERNOON. THE ONLINE SPC
4KM WRF WASNT TOO BAD...AND THE HRRR DID FINALLY CATCH ON. THESE
TWO MODELS...WITH SOME ADDITIONAL SUPPORT FROM GLOBAL
MODELS...DEPICT A BAND OF CONVECTION INITIATING AFTER MIDNIGHT IN
THE VICINITY OF EAST CENTRAL TEXAS NE TWD SHREVEPORT. THE
SOUTHWESTWARD EXTENT OF ANY SUCH DEVELOPMENT IS A BIT
UNCERTAIN...BUT IT IS NOT OUT OF THE QUESTION FOR NORTHERN ZONES
TO BE AFFECTED GIVEN THE THE PROJECTED EAST/NORTHEAST MOVEMENT.
WILL MAINTAIN HIGHEST POPS TONIGHT IN THIS AREA...AND HOLD ONTO
THE SEVERE WORDING.
GENERALLY PRESERVED THE INHERITED INLAND WIND HAZARDS...BUT DID
TWEAK THE MARINE HAZARDS A BIT...EASING OUT OF THE SCA FOR THE
COASTAL LAKES AND BAYS MID EVENING...AND THE INLAND WATERS WEST OF
CAMERON AFTER MIDNIGHT CONCURRENT WITH LATEST PROGS THAT SHOW
WINDS STARTING TO DECREASE FROM WEST TO EAST OVERNIGHT AND INTO
TOMORROW. A WIND ADVISORY MAY STILL BE WARRANTED FOR A TIME ACROSS
SOUTH/EAST CENTRAL LOUISIANA...BUT WILL LET THE OVERNIGHT CREW
MAKE THE CALL ON THAT AS IT LOOKS A LITTLE MORE MARGINAL.
CONVECTIVE PROSPECTS WILL ALSO SHIFT EAST TOMORROW...AS THE
CDFNT PUSHES JUST EAST OF A KSHV TO KLFK LINE BY TOMORROW
AFTERNOON. HAVE GENERALLY LEFT THIS PART OF THE FORECAST AS
IS...STAYING MAINLY WITH LOW TO MID RANGE POPS AND PRESERVING THE
SEVERE WORDING PER SPC DAY 2 CONVECTIVE OUTLOOK.
THE FRONT IS STILL FCST TO PUSH THROUGH THE DURING THE AFTERNOON
AND EVENING HOURS ON TUE...WITH THE SEVERE RISK DISPLACED TO OUR
EAST BY THIS TIME. ALTHOUGH STILL NOT IN IDEAL AGREEMENT...THE GFS
HAS COME A LONG WAY TOWARD THE ECMWF SOLUTION IN DEPICTING
SOUTHWESTERLY FLOW ALOFT...WITH ONE OR MORE FRONTAL WAVES/LOWS
DEVELOPING ALONG THE FRONT. APPEARS THAT THE BEST CHANCE OF ANY
RAIN AFFECTING THE AREA WOULD BE THU NIGHT-FRI...AS BOTH MODELS
DEPICTING A SHORTWAVE TROF PIVOTING THROUGH THE NW GULF COAST
REGION.
MARINE...
GUSTY SOUTH WINDS AND ROUGH SEAS WILL CONTINUE THIS EVENING AS A
LOW PRESSURE SYSTEM DEVELOPS IN THE PLAINS. WINDS WILL BEGIN TO
DIMINISH A BIT OVER THE COASTAL LAKES AND BAYS TONIGHT AND THE
WATERS WEST OF CAMERON LATE TONIGHT INTO TOMORROW. TIDES WILL BE
RUNNING ABOUT ONE FOOT ABOVE NORMAL TODAY AND MONDAY. THE CHANCE
OF SHOWERS AND THUNDERSTORMS WILL ALSO CONTINUE INTO EARLY NEXT
WEEK AS THIS LOW PRESSURE SYSTEM SLOWLY MOVES EAST THROUGH THE
CENTRAL UNTIED STATES...CULMINATING IN A FRONT CROSSING THE REGION
TUESDAY NIGHT. OFFSHORE FLOW WILL PREVAIL IN THE WAKE OF THE FRONT
FOR THE REST OF THE WORK WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 72 84 70 85 57 / 20 30 20 20 20
KBPT 72 84 69 85 58 / 20 20 20 20 10
KAEX 71 85 67 83 53 / 50 50 30 30 10
KLFT 72 84 71 85 58 / 30 40 40 30 30
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING
ZONES: ACADIA...CALCASIEU...EAST CAMERON...IBERIA...
JEFFERSON DAVIS...LAFAYETTE...LOWER ST. MARTIN...ST. MARY...
UPPER ST. MARTIN...VERMILION...WEST CAMERON.
TX...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING
ZONES: JEFFERSON...ORANGE.
GM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO
INTRACOASTAL CITY LA OUT 20 NM...WATERS FROM INTRACOASTAL
CITY TO CAMERON LA FROM 20 TO 60 NM...WATERS FROM CAMERON
LA TO HIGH ISLAND TX FROM 20 TO 60 NM...WATERS FROM LOWER
ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM.
SMALL CRAFT EXERCISE CAUTION UNTIL MIDNIGHT CDT TONIGHT FOR THE
FOLLOWING ZONES: CALCASIEU LAKE...SABINE LAKE.
SMALL CRAFT EXERCISE CAUTION UNTIL 7 AM CDT MONDAY FOR THE
FOLLOWING ZONES: VERMILION BAY.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH
ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY
TO CAMERON LA OUT 20 NM.
SMALL CRAFT EXERCISE CAUTION UNTIL 7 AM CDT MONDAY FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH
ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY
TO CAMERON LA OUT 20 NM.
&&
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.LAKECHARLES.GOV
WWW.TWITTER.COM/NWSLAKECHARLES
WWW.YOUTUBE.COM/NWSLAKECHARLES
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1250 AM EDT MON APR 28 2014
.SYNOPSIS...
LOW PRESSURE SOUTH OF NOVA SCOTIA WILL CONTINUE MOVING INTO THE
OPEN ATLANTIC TONIGHT INTO MONDAY. HIGH PRESSURE WILL BUILD SOUTH
ACROSS THE REGION MONDAY NIGHT THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1250 AM UPDATE...STARTING TO SEE SHOWERS DEVELOPING OVER
WESTERN/SOUTHERN NEW BRUNSWICK. THIS ACTIVITY WILL CONTINUE TO
MOVE WESTWARD AROUND THE TOP OF THE DEPARTING UPPER LOW. THIS
INFLUX OF MOISTURE HAS PROHIBITED TEMPERATURES FROM DROPPING VERY
MUCH TONIGHT; MOST AREAS ARE STILL IN THE UPPER 30S TO LOWER 40S.
FOR THIS UPDATE, ADJUSTED POPS UP A BIT, ESPECIALLY OVER
WASHINGTON COUNTY AS PER RADAR TRENDS. ALSO RAISED OVERNIGHT LOWS
BY A DEGREE OR TWO ACROSS THE NORTH. NO OTHER CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...
THE CHALLENGE WILL DEFINITELY BE THE TEMPERATURES AND WHERE TO
PLACE RAINFALL CHANCES.
LOW PRES WAS SPINNING SE OF NOVA SCOTIA PER THE 18Z ANALYSIS. SFC
TROUGH EXTENDING OFF THIS LOW EXTENDED BACK EASTERN AND CENTRAL
MAINE. THE FIRST BATCH OF LIGHT RAIN/SHOWERS MOVED SSW EARLY TODAY
AND ANOTHER ROUND IS APPROACHING FROM NEW BRUNSWICK. THE RAIN HAS
BEEN WEAKENING AS IT RUNS INTO DRIER AIR AS SEEN BY THE LATEST
SATELLITE VISIBLE IMAGERY SHOWING BREAKS IN THE CLOUDS. BEST
SUPPORT FOR SUBSTANTIAL RAIN HAS BEEN OVER THE EASTERN SECTIONS OF
WASHINGTON COUNTY. DECENT LLVL CONVERGENCE AND MID LEVEL FORCING
IS THERE AS SEEN BY BOTH THE RAP AND NAM12. EXPECTING THIS TREND
TO CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON. CARRIED CHANCE
POPS(30-50%) FOR THE CWA TONIGHT W/THE HIGHEST CHANCES ACROSS
NORTHERN AND EASTERN SECTIONS. AS ONE TRAVELS FURTHER W AND SW,
SHOWERS WILL WEAKEN DUE TO SUBSIDENCE IN PLACE. CLOUDS WILL HANG
AROUND THROUGHOUT THE NIGHT AND THIS WILL KEEP TEMPERATURES WELL
ABOVE 32F WHICH SHOULD ALLOW FOR ALL LIQUID PRECIP. RAINFALL
AMOUNTS HAVE BEEN LIGHT AND SEE NO SUPPORT FOR THIS TO CHANGE MUCH
OVER THE NEXT 24 HRS. THEREFORE, STAYED W/QPF OF 0.10" OR LESS
THROUGH MONDAY.
CONDITIONS LOOK TO IMPROVE THROUGHOUT THE DAY ON MONDAY AS HIGH
PRES IS FORECAST TO WEDGE DOWN FROM CANADA. SOME SUNSHINE IS
EXPECTED BY MONDAY AFTERNOON ESPECIALLY ACROSS THE NORTHERN AND
EASTERN SECTIONS WHILE THE CENTRAL HIGHLANDS WILL HANG ON TO MORE
CLOUDS. THIS WILL LEAD TO A VARIATION IN TEMPERATURES. DECIDED TO
BOOST DAYTIME HIGHS ON MONDAY UP TO READINGS AOA 50F MAINLY FOR
THE NORTHERN AND EASTERN SECTIONS. CENTRAL AND WESTERN AREAS WILL
HANG W/MORE CLOUDS THUS KEEPING TEMPERATURES DOWN INTO THE 40S
SOMEWHAT SIMILAR TO TODAY.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL RIDGE SOUTH ACROSS THE REGION MONDAY NIGHT
THROUGH EARLY WEDNESDAY...THEN BEGIN TO MOVE EAST LATER WEDNESDAY.
CLOUD COVER WILL DECREASE ACROSS THE REGION MONDAY NIGHT. MOSTLY
CLEAR SKIES WILL OCCUR ACROSS THE REGION TUESDAY INTO EARLY
WEDNESDAY. CLOUD COVER WILL THEN BEGIN TO INCREASE LATER
WEDNESDAY...PARTICULARLY ACROSS WESTERN PORTIONS OF THE FORECAST
AREA. TEMPERATURES WILL BE AT NEAR NORMAL...TO SLIGHTLY BELOW
NORMAL...LEVELS TUESDAY/WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AN UNSETTLED PATTERN WILL TAKE HOLD ONCE AGAIN FOR THE LONG RANGE
AS THE RIDGE BREAKS DOWN AND THE NEXT UPPER LEVEL LOW ADVANCES
TOWARD THE REGION. CLOUDS WILL INCREASE WEDNESDAY NIGHT WITH RAIN
AND SHOWERS DEVELOPING WEST TO EAST FOR THURSDAY AS AN OCCLUSION
MOVES THROUGH AHEAD OF A SURFACE LOW ADVANCING NORTH ALONG THE
COAST. STEADIER RAIN LOOKS TO TAPER OFF THURSDAY NIGHT WITH RAIN
AMOUNTS OF A HALF INCH TO AN INCH POSSIBLE BY THIS TIME. EXPECT
SHOWERS TO LINGER INTO FRIDAY IN ASSOCIATION WITH THE BROAD UPPER
LEVEL LOW SITUATED OVER THE GREAT LAKES BY THIS TIME AND A
LINGERING SURFACE TROUGH.
SOME UNCERTAINTY DEVELOPS IN THE FORECAST FOR THE BEGINNING OF
NEXT WEEKEND. OVERALL, THE UNSETTLED PATTERN REMAINS HOWEVER THE
ECMWF MODEL BRINGS A BRIEF WINDOW OF SOME PARTIAL CLEARING AND
DRYING IN FOR SATURDAY WHILE THE GFS SUGGESTS MORE CLOUDS WITH AT
LEAST A FEW LINGERING SHOWERS. AT THIS POINT WILL KEEP IN THE
CHANCE OF SHOWERS WITH MOSTLY CLOUDY SKIES. A BETTER CHANCE FOR
MORE WIDESPREAD RAIN AND SHOWERS DEVELOPS ONCE AGAIN FOR SATURDAY
NIGHT AND SUNDAY AS THE NEXT SURFACE WAVE ASSOCIATED WITH THE
BROAD UPPER TROUGH DEVELOPS SOUTH OF THE REGION AND MOVES NORTH UP
THE COAST. TEMPERATURES THROUGH THE LONG RANGE ARE FORECAST TO
REMAIN WITHIN A FEW DEGREES OF AVERAGE FOR THIS TIME OF YEAR.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR AT ALL THE TERMINALS AS OF 01Z. EXPECTATION IS
FOR CIGS TO DROP TO MVFR ACROSS ALL THE TERMINALS OVERNIGHT. A
PERIOD OF IFR IS POSSIBLE LATE TONIGHT(AFT 08Z) AND THIS WILL
MAINLY BE FOR THE NORTHERN TERMINALS. DECIDED TO STAY W/MVFR
THROUGH MIDDAY MONDAY. AN IMPROVEMENT TO VFR IS EXPECTED BY MON
EVENING.
SHORT TERM: VFR CONDITIONS ARE EXPECTED ACROSS THE REGION MONDAY
NIGHT THROUGH WEDNESDAY. VFR WEDNESDAY NIGHT WILL GIVE WAY TO
MVFR AND THEN IFR THURSDAY AS RAIN MOVES IN FROM WEST TO EAST.
MVFR/IFR CONDITIONS ARE LIKELY TO PERSIST INTO FRIDAY DUE TO LOW
STRATUS WITH LINGERING SHOWERS.
&&
.MARINE...
NEAR TERM: NO SCA ATTM. LATEST MODEL GUIDANCE HAS BEEN RUNNING TOO
HIGH FOR THE WINDS AND ADJUSTMENTS WERE MADE TO PUSH THE SPEEDS
BACK. THE WIND WILL GRADUALLY INCREASE OVER THE NEXT 24 HOURS AND
THE SEAS WILL SLOWLY BUILD. A SCA MAY BE NEEDED BY LATE MONDAY.
SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE ON THE
WATERS MONDAY NIGHT INTO EARLY TUESDAY NIGHT. CONDITIONS ARE
EXPECTED TO BE BELOW SMALL CRAFT ADVISORY LEVELS LATER TUESDAY
NIGHT INTO WEDNESDAY. SCA CONDITIONS WILL BE POSSIBLE THURSDAY AS
SE WINDS STRENGTHEN AND WAVE HEIGHTS INCREASE AHEAD OF AN
OCCLUSION MOVING THROUGH WHICH WILL ALSO BRING RAIN AND THE
POTENTIAL FOR FOG. THESE CONDITIONS IMPROVE FOR FRIDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...NORCROSS
LONG TERM...FITZSIMMONS
AVIATION...HASTINGS/HEWITT/NORCROSS
MARINE...HASTINGS/HEWITT/NORCROSS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1038 PM EDT TUE APR 29 2014
.SYNOPSIS...
A CUTOFF LOW OVER THE MIDWEST WILL DRIFT NORTHEASTWARD TOWARD THE
GREAT LAKES THROUGH WEDNESDAY. A WARM FRONT OVER NORTH CAROLINA
THIS EVENING WILL LIFT NORTHWARD INTO THE REGION WEDNESDAY AND
WEDNESDAY NIGHT. A COLD FRONT WILL MOVE THROUGH THE AREA THURSDAY.
HIGH PRESSURE IS EXPECTED TO RETURN FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
EVENING WATER VAPOR LOOP SHOWS THE ERN TWO-THIRDS OF THE CONUS UNDER
BROAD CYCLONIC FLOW IN ASSOCIATION WITH A CUTOFF LOW OVER THE
UPPER MIDWEST. A UNUSUALLY DEEP SLY FETCH DOWNSTREAM OF THE CUTOFF
LOW CONTINUES TO DRAW TROPICAL MOISTURE FROM THE GULF OF MEXICO
AND ATLANTIC UP THE ERN SEABOARD. BACKWARD TRAJECTORIES EVEN SHOW
MOISTURE ALL THE WAY FROM THE CARIBBEAN REACHING THE MID-ATLANTIC
REGION BY WED.
AT THE SFC...A WARM FRONT WAS SITUATED IN NC AS OF 00Z AND IS
STARTING TO NUDGE NWD TOWARD EXTREME SERN VA. THE CWA WILL
CONTINUE TO BE SITUATED IN COOL SECTOR TO THE NORTH OF THE
BOUNDARY TNGT AS A COLD AIR DAMMING WEDGE HOLDS STRONG. TEMPS CWA
WIDE ARE IN THE UPPER 40S AND LOWER 50S THIS EVE UNDER THE
INFLUENCE OF ONSHORE FLOW. WINDS ARE EXPECTED TO GRADUALLY VEER
MORE OUT OF THE SE OVNGT AS THE WARM FRONT APPROACHES FROM THE
SOUTH. TEMPS WILL REMAIN STEADY OR GRADUALLY INCREASE LATE TNGT AS
A RESULT.
SHOWERS AND TSTMS THAT DEVELOPED IN SERN VA WILL CONTINUE TO MOVE
NWD INTO THE CWA...IMPACTING LOCATIONS EAST OF THE BLUE RIDGE THRU
THE REMAINDER OF THE EVE. 00Z IAD RAOB SHOWS VERY LIMITED CAPE
AVAILABLE FOR ELEVATED CONVECTION ABOVE H8 WARM NOSE SO CHANCES FOR
TSTMS LOW THIS EVE AS THIS ACTIVITY MOVES INTO AN INCREASINGLY
STABLE AIRMASS. PRECIP EXPECTED TO REDEVELOP LATE TNGT ACROSS THE
CWA IN ASSOCIATION WITH A 40+ KT SLY LLVL JET PRODUCING ISENTROPIC
LIFT ACROSS THE WARM FRONT. FCST MODEL SOUNDINGS SHOW PWATS AND
ELEVATED INSTABILITY ALSO INCREASING FROM SOUTH TO NORTH...SO HVY
DOWNPOURS AND TSTMS WILL INCREASE THE THREAT OF FLASH FLOODING AS WE
HEAD TOWARD THE ERY MRNG.
THE LATEST RAP AND 18Z NAM/GFS BRING THE WARM FRONT STEADILY
NORTHWARD THRU THE REGION ON WED. AM SKEPTICAL OF HOW QUICKLY THE
WARM FRONT ACTUALLY MAKES IT THRU THE REGION THOUGH AS MODELS
TYPICAL ARE TOO AGGRESSIVE WITH ERODING THE CAD WEDGE. THE POSITION
OF THE WARM FRONT WILL DETERMINE NOT ONLY TEMPS BUT WHERE THE
GREATEST THREAT OF SEVERE STORMS INCLUDING THE POTENTIAL FOR
TORNADOES WILL EXIST. IF THE WARM FRONT LINGERS NEAR THE CWA DURING
THE AFTN...THE TORNADO THREAT WOULD BE GREATEST ALONG AND JUST TO
THE SOUTH OF THE BOUNDARY.
PREVIOUS DISCUSSION...
THE WARM FRONT WILL MOVE INTO THE AREA WEDNESDAY FROM SOUTH TO
NORTH. DEEP MOISTURE WILL CONTINUE TO ADVECT INTO THE AREA DURING
THIS TIME...CAUSING MORE WIDESPREAD RAINFALL ALONG WITH AN
INCREASING THREAT FOR THUNDERSTORMS. A SHEAR VECTOR NEARLY
PARALLEL TO THE COLD FRONT ASSOCIATED WITH THIS LOW MEANS THAT
BANDS OF SHOWERS AND THUNDERSTORMS WILL TRAIN OVER ONE ANOTHER.
PWATS WILL BE NEAR RECORD LEVELS FOR THIS TIME OF YEAR...AND WITH
TRAINING CONVECTION THERE WILL BE AREAS OF VERY HEAVY RAINFALL IN
A SHORT PERIOD OF TIME. THE FLASH FLOOD WATCH CONTINUES THROUGH
WEDNESDAY.
THUNDERSTORMS WILL BECOME ROOTED WITHIN THE BOUNDARY
LAYER...ESPECIALLY LATER WEDNESDAY MORNING THROUGH WEDNESDAY
AFTERNOON AS INSTABILITY INCREASES BEHIND THE WARM FRONT. SHEAR
PROFILES WILL BE VERY STRONG...INCREASING THE CHANCE FOR SEVERE
WEATHER. THE PRIMARY THREATS WILL BE DAMAGING WINDS AND ISOLATED
TORNADOES. THE BEST CHANCE FOR THIS TO OCCUR WILL BE FROM WESTERN
MARYLAND AND EASTERN WEST VIRGINIA ACROSS NORTHERN AND CENTRAL
VIRGINIA INTO EXTREME SOUTHERN MARYLAND.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
A SEVERE WEATHER THREAT WILL PERSIST INTO THE EVENING HOURS
WEDNESDAY...EXPANDING NORTH INTO MARYLAND AS THE WARM FRONT AND
UNSTABLE AIR EXPAND NORTHWARD VIA A 40-KNOT LOW-LEVEL JET.
LARGE...LOOPING HODOGRAPHS INDICATE A FAVORABLE ENVIRONMENT FOR
ROTATING UPDRAFTS...AND SUGGESTS THAT STORMS ROOTED IN THE BOUNDARY
LAYER COULD POSE A TORNADO RISK TOMORROW EVENING GIVEN MEAN AND
RIGHT-MOVING STORM MOTION VECTORS LARGELY PARALLEL TO 0-1 KM
VORTICITY VECTOR. THIS IS ALSO SUPPORTED BY HELICITY VALUES OF 300
TO 500 M2/S2 IN THE VICINITY OF THE WARM FRONT MOVING NORTH ACROSS
THE POTOMAC RIVER DURING THE EVENING. THE MAGNITUDE OF THIS RISK
WILL BE MODULATED BY HOW MUCH SURFACE HEATING OCCURS DURING THE
AFTERNOON...BUT MOST GUIDANCE INCLUDING THE LATEST SREF INDICATE
MLCAPE ON THE ORDER OF 500-1000 J/KG /HIGHEST SOUTH/ WHICH SHOULD BE
SUFFICIENT FOR ORGANIZED SEVERE CONVECTION GIVEN RICH MOISTURE AND A
MODERATELY FORCED SYNOPTIC ENVIRONMENT.
SHEAR PROFILES WILL GRADUALLY BECOME LESS FAVORABLE FOR ROTATING
UPDRAFTS LATER IN THE EVENING...AND INCREASING STABILITY WITH THE
ONSET OF A NOCTURNAL INVERSION AS WELL AS CONVECTIVE OVERTURNING
WILL RESULT IN A DECREASING SEVERE WEATHER THREAT DURING THE
OVERNIGHT. HOWEVER THE PARENT COLD FRONT IS A SLOW-MOVER...AND AS
SUCH MULTIPLE ROUNDS OF SHOWERS AND ELEVATED THUNDERSTORMS
CONTAINING HEAVY RAINFALL WILL PERSIST THROUGH MUCH OF THE NIGHT
ESPECIALLY EAST OF THE BLUE RIDGE MOUNTAINS. FOR MORE ON THE
FLOOD/FLASH FLOOD THREAT...PLEASE SEE THE HYDROLOGY SECTION BELOW.
POCKETS OF SHOWERS OR EVEN A FEW THUNDERSTORMS COULD LINGER INTO
THURSDAY AS THE COLD FRONT SLOWLY SLIDES OFF THE COAST. HIGH
PRESSURE WILL BUILD INTO THE REGION TO END THE WEEK WITH
TEMPERATURES NEAR OR SLIGHTLY BELOW NORMAL EXPECTED IN A MUCH DRIER
REGIME.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE LONG TERM FORECAST WILL BE MUCH QUIETER THAN THE NEAR AND SHORT
TERMS OVERALL. A COLD FRONT EXTENDING SOUTH FROM LOW PRESSURE OVER
THE HUDSON BAY MAY BRING SOME BRIEF LIGHT SHOWERS ALONG THE HIGHER
ELEVATIONS IN THE MOUNTAINS AND THE MASON-DIXON LINE DURING THE DAY
SATURDAY. NOT EXPECTING THE FRONT TO BE STRONG ENOUGH TO BRING ANY
PRECIP TO AREAS EAST OF THE BLUE RIDGE AND ALONG AND SOUTH OF THE
METRO AREAS CURRENTLY. THE PRIMARY IMPACT FOR MOST OF THE AREA WILL
BE AN INCREASE IN CLOUDS...RESULTING IN PARTLY SUNNY SKIES AS THE
FRONT PASSES.
A SECONDARY DRY COLD FRONT WILL SWING THROUGH SUNDAY AS THE LOW
CROSSES NEW ENGLAND. THIS FRONT WILL ONLY BRING A SLIGHT INCREASE IN
CLOUDS AS THERE IS LITTLE DIFFERENCE BETWEEN THE AIR MASSES ON
EITHER SIDE OF THE BOUNDARY. HIGH PRESSURE WILL FILL BACK IN FOR THE
BEGINNING OF THE WORKWEEK BEFORE A STATIONARY/WARM FRONT MAY DEVELOP
OVER THE MID ATLANTIC ON TUESDAY.
TEMPERATURES WILL BE RATHER CONSISTENT THROUGH THE LONG TERM. HIGHS
WILL GENERALLY BE IN THE UPPER 60S NORTH OF I66 AND IN THE LOWER 70S
ALONG THE CENTRAL VA PIEDMONT. LOWS WILL BE IN THE MID 40S TO LOWER
50S THROUGHOUT THE TERM.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
A WARM FRONT WILL APPROACH FROM THE SOUTH TNGT. THE TERMINALS WILL
BE LOCATED IN COOL ELY FLOW AND LOW CLOUDS TNGT. CIGS PREDOMINATELY
IN IFR CAT TNGT. PERIOD OF SHRA WILL BE HEAVY AT TIMES
TNGT...RESULTING IN PERIOD OF IFR VSBYS. A FEW THUNDERSTORMS ARE
POSSIBLE ESPECIALLY AFTER 06Z.
HEAVY SHOWERS AND THUNDERSTORMS WILL CONTINUE WEDNESDAY WITH IFR
CONDITIONS. THUNDERSTORMS MAY BECOME SEVERE...WITH DAMAGING WINDS
AND ISOLATED TORNADOES BEING THE PRIMARY THREAT. THE BEST CHANCE
FOR SEVERE THUNDERSTORMS WILL BE IN THE AFTERNOON. CIGS START OFF
IN IFR BUT MAY IMPROVE TO MVFR BEHIND THE WARM FRONT. WINDS SHIFT
OUT OF THE S-SE AND INCREASE TO 15-25 KT IN WAKE OF FROPA AS WELL.
MODERATE CONFIDENCE IN SUB-VFR CONDITIONS IN HEAVY RAINFALL AND
THUNDERSTORMS WEDNESDAY NIGHT...THEN GRADUALLY IMPROVING TO VFR
THURSDAY AND PERSISTING INTO FRIDAY AS HIGH PRESSURE BUILDS.
CONFIDENCE IS LOW FOR ANY AVIATION HAZARDS IN THE LONG TERM.
&&
.MARINE...
UPGRADED TO A GALE WRNG FOR THE MD CHSPK BAY SOUTH OF SANDY POINT
AND FOR THE LWR TIDAL POTOMAC RVR THRU WED NGT. WHILE WINDS WILL
GENERALLY BE BETWEEN 20-30 KT IN THESE ZONES...HVY SHOWERS AND
STORMS WILL TRANSPORT HIGHER WINDS ALOFT DOWN TO THE SFC. ALREADY
HAD 35 KT GUSTS OCCUR AT THE LOWER HOOPER ISLAND AND BISHOPS HEAD
BUOYS LATE THIS AFTN DESPITE NO LIGHTNING. GIVEN THE HIGH
FREQUENCY OF THESE HEAVIER SHOWERS AND STORMS EXPECTED OVER THE
NEXT 36 HRS...A GALE WARNING WOULD COVER THIS THREAT. THE GALE
WARNING MAY NEED TO BE EXPANDED NWD BUT CONFIDENCE NOT HIGH ENOUGH
TO UPGRADE ATTM WITH THE NRN MARINE ZONES SITUATED DEEPER INTO
THE COOLER/STABLE SECTOR FARTHER TO THE NORTH OF THE WARM FRONT.
PREVIOUS DISCUSSION...
A WARM FRONT WILL APPROACH THE WATERS TONIGHT AND THE PRESSURE
GRADIENT WILL REMAIN STRONG AHEAD OF THE BOUNDARY. A SMALL CRAFT
ADVISORY IS IN EFFECT FOR THE WATERS DURING THIS TIME. THE SMALL
CRAFT ADVISORY CONTINUES THROUGH WEDNESDAY AS THE WARM FRONT MOVES
OVERHEAD. A GALE WARNING MAY ALSO BE NEEDED FOR PORTIONS OF THE
WATERS WEDNESDAY.
A STRONG SOUTHERLY LOW-LEVEL JET AHEAD OF A SLOW-MOVING COLD FRONT
WILL RESULT IN MODERATE TO HIGH SMALL CRAFT LEVEL GUSTS /25-30 KTS/
WEDNESDAY INTO WEDNESDAY NIGHT. GALE GUSTS ARE POSSIBLE FOR A TIME
AS WELL ON AREA WATERS...BOTH SYNOPTICALLY AND IN STRONGER
CONVECTION. SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN AND GUSTY
WINDS WILL LOCALLY REDUCE VISIBILITY AND INCREASE SEAS WEDNESDAY
INTO WEDNESDAY NIGHT. SMALL CRAFT ADVISORY GUSTS ARE LIKELY IN
NORTHWEST FLOW BEHIND THE FRONT THURSDAY AFTERNOON. QUIETER WEATHER
WILL RETURN TO THE WATERS FRIDAY. CONFIDENCE IS LOW FOR ANY MARINE
HAZARDS IN THE LONG TERM.
&&
.HYDROLOGY...
RAIN CONTINUES TO SPREAD BACK INTO THE AREA THIS EVE...WITH
CONVECTION DEVELOPING OVER SRN/CENTRAL VA. ADDITIONAL RAINFALL IS
FORECAST TO FUNNEL INTO THE AREA OVNGT. THIS PRECIPITATION WILL
BE AIDED IN ITS CONTINUED DEVELOPMENT BY THREE FACTORS...LOW-
LEVEL UPSLOPE FLOW TOWARD THE BLUE RIDGE...APPROACHING ENERGY
ALOFT...AND AN ADVANCING SURFACE WARM FRONT.
AS WARMER AND MORE MOIST AIR SURGES INTO THE REGION TONIGHT...THE
HEAVY RAIN THREAT WILL INCREASE ACCORDINGLY. PWAT VALUES ARE
EXPECTED TO EXCEED 1.5 INCHES AFTER MIDNIGHT...AND CONTINUE TO RISE
ON WEDNESDAY...PEAKING JUST BELOW 2 INCHES BY EARLY AFTERNOON.
HIRES MODELS AND THE LATEST OPERATIONAL GFS/NAM SHOW THE POTENTIAL
FOR WIDESPREAD 2-5 INCHES WITH THE LEAST EXPECTED WEST OF THE BLUE
RIDGE AND THE MOST SOMEWHERE BETWEEN THE BLUE RIDGE AND I-95
CORRIDOR.
FLASH FLOOD WATCH REMAINS IN EFFECT AREA WIDE...AND RIVER FLOOD
WATCHES ARE IN EFFECT AT EIGHT FORECAST POINTS...INCLUDING THE
RECENTLY ADDED WATCH THIS EVE FOR LITTLE FALLS. CONFIDENCE WAS NOT
HIGH ENOUGH TO UPGRADE ANY OF THE WATCHES TO WARNINGS THIS FAR
PRIOR TO THE HEAVY RAINFALL. CONTINUE TO MONITOR THE LATEST
FORECASTS AND DISCUSSIONS...AND MONITOR FOR POTENTIAL WARNINGS.
&&
.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES ARE RUNNING AROUND 1.2 TO 1.4 FT THIS EVENING ON
CHESAPEAKE BAY...AND BETWEEN 1.5 AND 2.0 FT ON THE UPPER TIDAL
POTOMAC. WINDS WILL GRADUALLY SHIFT TO THE SE OVERNIGHT...WHICH
SHOULD KEEP ANOMALIES AT OR HIGHER THAN CURRENT LEVELS BY HIGH TIDE
IN THE MORNING. COASTAL FLOOD ADVISORIES HAVE BEEN ISSUED FOR THE
WEDNESDAY MORNING HIGH TIDE CYCLE. IT IS STILL POSSIBLE THAT
MODERATE FLOODING REQUIRING COASTAL FLOOD WARNINGS MAY BE NEEDED AT SOME
POINTS...PARTICULARLY ANNAPOLIS AND WASHINGTON DC...BUT CONFIDENCE
IS NOT HIGH ENOUGH TO WARRANT AN UPGRADE AT THIS TIME.
THE COASTAL FLOOD WATCH REMAINS IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH
THROUGH THURSDAY MORNING FOR THE WESTERN SHORE OF THE CHESAPEAKE
BAY. ANOMALIES SHOULD BE EVEN HIGHER...BEFORE A COLD FRONT CROSSES
THE WATERS AND MAYBE PUSHES SOME OF THE EXCESS WATER OUT OF THE
ESTUARY. MINOR TIDAL FLOODING IS EXPECTED FOR LOCATIONS ALONG THE
UPPER TIDAL POTOMAC RIVER.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FLASH FLOOD WATCH THROUGH LATE WEDNESDAY NIGHT FOR DCZ001.
COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR DCZ001.
COASTAL FLOOD ADVISORY FROM 7 AM TO NOON EDT WEDNESDAY FOR
DCZ001.
MD...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR MDZ003-004-501-
502.
FLASH FLOOD WATCH THROUGH LATE WEDNESDAY NIGHT FOR MDZ005>007-
009>011-013-014-016>018.
COASTAL FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
MORNING FOR MDZ007-011-014-017-018.
COASTAL FLOOD ADVISORY UNTIL 1 PM EDT WEDNESDAY FOR MDZ007-011-
014-017-018.
VA...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR VAZ025>031-
036>040-042-050-051-501-503-504.
FLASH FLOOD WATCH THROUGH LATE WEDNESDAY NIGHT FOR VAZ052>057-
502.
COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR VAZ053-
054.
COASTAL FLOOD ADVISORY FROM 7 AM TO NOON EDT WEDNESDAY FOR
VAZ053-054.
WV...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR WVZ050>053-055-
501>506.
MARINE...GALE WARNING UNTIL 6 AM EDT THURSDAY FOR ANZ532>534-537-
540>543.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ530-531-
535-536-538-539.
&&
$$
SYNOPSIS...JRK/BJL
NEAR TERM...JRK/BJL
SHORT TERM...DFH
LONG TERM...CEB
AVIATION...JRK/BJL/CEB/DFH
MARINE...JRK/BJL/CEB/DFH
HYDROLOGY...JRK/JCE
TIDES/COASTAL FLOODING...KCS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1010 PM EDT TUE APR 29 2014
.SYNOPSIS...
A SLOW MOVING LOW PRESSURE SYSTEM OVER THE CENTRAL U.S WILL BRING
PERIODIC SHOWERS THROUGH MUCH OF THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
LATE EVE UPDATE WAS ISSUED TO RECONSTRUCT POPS BASED ON THE LATEST
RADAR AND HRRR TRENDS.
THUNDERSTORMS CONTD ALNG CONVERGENCE ZONE ASSOCIATED WITH OCCLUDING
FRONT TO THE WEST OF INTERSTATE 77. INSTABILITY HAS BEEN
FADING...AND WL CONT TO DO SO...BUT THUNDERSTORM MENTION WAS
MAINTAINED FOR A FEW MORE HRS AS THAT ZONE IS SHUNTED EWD.
OTHERWISE...SHOWER CHCS FOR THE REST OF THE AREA ARE STILL
EXPECTED TO INCRS AS SHRTWV MOVS THROUGH THE ERN FLANK OF THE
BROAD PARENT LOW CNTRD OVR THE MIDWEST.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
BROAD UPPER LOW WILL SLOWLY MEANDER NORTH AND EAST MAINTAINING THE
CHANCE FOR SHOWERS THROUGH THE REMAINDER OF THE WEEK. WITH COLD
AIR ALOFT AND PLENTY OF LOW LEVEL MOISTURE...EXPECT THAT MOST OF
THE ACTIVITY WILL BE DIURNALLY DRIVEN BUT MAINTAINED AT LEAST
SLIGHT CHANCE POPS OVERNIGHT WEDNESDAY AND THURSDAY AS WELL.
MOSTLY CLOUDY SKIES AND COOLING TEMPERATURES ALOFT SHOULD HELP TO
KEEP TEMPERATURES A FEW DEGREES BELOW SEASONAL NORMALS THROUGH THE
PERIOD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
PATTERN BEGINS TO BREAK DOWN TOWARDS THE BEGINNING OF THE
WEEKEND...WITH THE RIDGE OF HIGH PRESSURE THAT HAD BEEN PARKED
OVER THE ERN PACIFIC SLOWLY PUSHING EAST TO THE PLAINS. THIS PATTERN
WILL KEEP NORTHWEST FLOW IN PLACE WITH RAIN CHANCES AND COOLER
TEMPERATURES INTO SUNDAY. GRADUAL WARMING TREND EARLY NEXT WEEK AS
THE UPPER HIGH MOVES EAST TOWARD THE REGION.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
GUSTY SOUTHEAST FLOW WILL DIMINISH OVERNIGHT AS A BOUNDARY PUSHES
NORTH AND THE PRESSURE GRADIENT BEGINS TO RELAX. PRECIPITATION
WILL REDEVELOP EARLY WEDNESDAY MORNING AND PERSIST THROUGH MUCH OF
THE DAY AS ANOTHER SHORTWAVE TRANSITIONS OVER THE REGION.
.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
PERIODIC RESTRICTIONS IN SHOWERS WL CONT INTO THE WEEKEND AS THE
LARGE LOW PRES AREA PROGRESSES SLOWLY EWD.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
942 PM EDT TUE APR 29 2014
.SYNOPSIS...
A CUTOFF LOW OVER THE MIDWEST WILL DRIFT NORTHEASTWARD TOWARD THE
GREAT LAKES THROUGH WEDNESDAY. A WARM FRONT OVER NORTH CAROLINA
THIS EVENING WILL LIFT NORTHWARD INTO THE REGION WEDNESDAY AND
WEDNESDAY NIGHT. A COLD FRONT WILL MOVE THROUGH THE AREA THURSDAY.
HIGH PRESSURE IS EXPECTED TO RETURN FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
EVENING WATER VAPOR LOOP SHOWS THE ERN TWO-THIRDS OF THE CONUS UNDER
BROAD CYCLONIC FLOW IN ASSOCIATION WITH A CUTOFF LOW OVER THE
UPPER MIDWEST. A UNUSUALLY DEEP SLY FETCH DOWNSTREAM OF THE CUTOFF
LOW CONTINUES TO DRAW TROPICAL MOISTURE FROM THE GULF OF MEXICO
AND ATLANTIC UP THE ERN SEABOARD. BACKWARD TRAJECTORIES EVEN SHOW
MOISTURE ALL THE WAY FROM THE CARIBBEAN REACHING THE MID-ATLANTIC
REGION BY WED.
AT THE SFC...A WARM FRONT WAS SITUATED IN NC AS OF 00Z AND IS
STARTING TO NUDGE NWD TOWARD EXTREME SERN VA. THE CWA WILL
CONTINUE TO BE SITUATED IN COOL SECTOR TO THE NORTH OF THE
BOUNDARY TNGT AS A COLD AIR DAMMING WEDGE HOLDS STRONG. TEMPS CWA
WIDE ARE IN THE UPPER 40S AND LOWER 50S THIS EVE UNDER THE
INFLUENCE OF ONSHORE FLOW. WINDS ARE EXPECTED TO GRADUALLY VEER
MORE OUT OF THE SE OVNGT AS THE WARM FRONT APPROACHES FROM THE
SOUTH. TEMPS WILL REMAIN STEADY OR GRADUALLY INCREASE LATE TNGT AS
A RESULT.
SHOWERS AND TSTMS THAT DEVELOPED IN SERN VA WILL CONTINUE TO MOVE
NWD INTO THE CWA...IMPACTING LOCATIONS EAST OF THE BLUE RIDGE THRU
THE REMAINDER OF THE EVE. 00Z IAD RAOB SHOWS VERY LIMITED CAPE
AVAILABLE FOR ELEVATED CONVECTION ABOVE H8 WARM NOSE SO CHANCES FOR
TSTMS LOW THIS EVE AS THIS ACTIVITY MOVES INTO AN INCREASINGLY
STABLE AIRMASS. PRECIP EXPECTED TO REDEVELOP LATE TNGT ACROSS THE
CWA IN ASSOCIATION WITH A 40+ KT SLY LLVL JET PRODUCING ISENTROPIC
LIFT ACROSS THE WARM FRONT. FCST MODEL SOUNDINGS SHOW PWATS AND
ELEVATED INSTABILITY ALSO INCREASING FROM SOUTH TO NORTH...SO HVY
DOWNPOURS AND TSTMS WILL INCREASE THE THREAT OF FLASH FLOODING AS WE
HEAD TOWARD THE ERY MRNG.
THE LATEST RAP AND 18Z NAM/GFS BRING THE WARM FRONT STEADILY
NORTHWARD THRU THE REGION ON WED. AM SKEPTICAL OF HOW QUICKLY THE
WARM FRONT ACTUALLY MAKES IT THRU THE REGION THOUGH AS MODELS
TYPICAL ARE TOO AGGRESSIVE WITH ERODING THE CAD WEDGE. THE POSITION
OF THE WARM FRONT WILL DETERMINE NOT ONLY TEMPS BUT WHERE THE
GREATEST THREAT OF SEVERE STORMS INCLUDING THE POTENTIAL FOR
TORNADOES WILL EXIST. IF THE WARM FRONT LINGERS NEAR THE CWA DURING
THE AFTN...THE TORNADO THREAT WOULD BE GREATEST ALONG AND JUST TO
THE SOUTH OF THE BOUNDARY.
PREVIOUS DISCUSSION...
THE WARM FRONT WILL MOVE INTO THE AREA WEDNESDAY FROM SOUTH TO
NORTH. DEEP MOISTURE WILL CONTINUE TO ADVECT INTO THE AREA DURING
THIS TIME...CAUSING MORE WIDESPREAD RAINFALL ALONG WITH AN
INCREASING THREAT FOR THUNDERSTORMS. A SHEAR VECTOR NEARLY
PARALLEL TO THE COLD FRONT ASSOCIATED WITH THIS LOW MEANS THAT
BANDS OF SHOWERS AND THUNDERSTORMS WILL TRAIN OVER ONE ANOTHER.
PWATS WILL BE NEAR RECORD LEVELS FOR THIS TIME OF YEAR...AND WITH
TRAINING CONVECTION THERE WILL BE AREAS OF VERY HEAVY RAINFALL IN
A SHORT PERIOD OF TIME. THE FLASH FLOOD WATCH CONTINUES THROUGH
WEDNESDAY.
THUNDERSTORMS WILL BECOME ROOTED WITHIN THE BOUNDARY
LAYER...ESPECIALLY LATER WEDNESDAY MORNING THROUGH WEDNESDAY
AFTERNOON AS INSTABILITY INCREASES BEHIND THE WARM FRONT. SHEAR
PROFILES WILL BE VERY STRONG...INCREASING THE CHANCE FOR SEVERE
WEATHER. THE PRIMARY THREATS WILL BE DAMAGING WINDS AND ISOLATED
TORNADOES. THE BEST CHANCE FOR THIS TO OCCUR WILL BE FROM WESTERN
MARYLAND AND EASTERN WEST VIRGINIA ACROSS NORTHERN AND CENTRAL
VIRGINIA INTO EXTREME SOUTHERN MARYLAND.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
A SEVERE WEATHER THREAT WILL PERSIST INTO THE EVENING HOURS
WEDNESDAY...EXPANDING NORTH INTO MARYLAND AS THE WARM FRONT AND
UNSTABLE AIR EXPAND NORTHWARD VIA A 40-KNOT LOW-LEVEL JET.
LARGE...LOOPING HODOGRAPHS INDICATE A FAVORABLE ENVIRONMENT FOR
ROTATING UPDRAFTS...AND SUGGESTS THAT STORMS ROOTED IN THE BOUNDARY
LAYER COULD POSE A TORNADO RISK TOMORROW EVENING GIVEN MEAN AND
RIGHT-MOVING STORM MOTION VECTORS LARGELY PARALLEL TO 0-1 KM
VORTICITY VECTOR. THIS IS ALSO SUPPORTED BY HELICITY VALUES OF 300
TO 500 M2/S2 IN THE VICINITY OF THE WARM FRONT MOVING NORTH ACROSS
THE POTOMAC RIVER DURING THE EVENING. THE MAGNITUDE OF THIS RISK
WILL BE MODULATED BY HOW MUCH SURFACE HEATING OCCURS DURING THE
AFTERNOON...BUT MOST GUIDANCE INCLUDING THE LATEST SREF INDICATE
MLCAPE ON THE ORDER OF 500-1000 J/KG /HIGHEST SOUTH/ WHICH SHOULD BE
SUFFICIENT FOR ORGANIZED SEVERE CONVECTION GIVEN RICH MOISTURE AND A
MODERATELY FORCED SYNOPTIC ENVIRONMENT.
SHEAR PROFILES WILL GRADUALLY BECOME LESS FAVORABLE FOR ROTATING
UPDRAFTS LATER IN THE EVENING...AND INCREASING STABILITY WITH THE
ONSET OF A NOCTURNAL INVERSION AS WELL AS CONVECTIVE OVERTURNING
WILL RESULT IN A DECREASING SEVERE WEATHER THREAT DURING THE
OVERNIGHT. HOWEVER THE PARENT COLD FRONT IS A SLOW-MOVER...AND AS
SUCH MULTIPLE ROUNDS OF SHOWERS AND ELEVATED THUNDERSTORMS
CONTAINING HEAVY RAINFALL WILL PERSIST THROUGH MUCH OF THE NIGHT
ESPECIALLY EAST OF THE BLUE RIDGE MOUNTAINS. FOR MORE ON THE
FLOOD/FLASH FLOOD THREAT...PLEASE SEE THE HYDROLOGY SECTION BELOW.
POCKETS OF SHOWERS OR EVEN A FEW THUNDERSTORMS COULD LINGER INTO
THURSDAY AS THE COLD FRONT SLOWLY SLIDES OFF THE COAST. HIGH
PRESSURE WILL BUILD INTO THE REGION TO END THE WEEK WITH
TEMPERATURES NEAR OR SLIGHTLY BELOW NORMAL EXPECTED IN A MUCH DRIER
REGIME.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE LONG TERM FORECAST WILL BE MUCH QUIETER THAN THE NEAR AND SHORT
TERMS OVERALL. A COLD FRONT EXTENDING SOUTH FROM LOW PRESSURE OVER
THE HUDSON BAY MAY BRING SOME BRIEF LIGHT SHOWERS ALONG THE HIGHER
ELEVATIONS IN THE MOUNTAINS AND THE MASON-DIXON LINE DURING THE DAY
SATURDAY. NOT EXPECTING THE FRONT TO BE STRONG ENOUGH TO BRING ANY
PRECIP TO AREAS EAST OF THE BLUE RIDGE AND ALONG AND SOUTH OF THE
METRO AREAS CURRENTLY. THE PRIMARY IMPACT FOR MOST OF THE AREA WILL
BE AN INCREASE IN CLOUDS...RESULTING IN PARTLY SUNNY SKIES AS THE
FRONT PASSES.
A SECONDARY DRY COLD FRONT WILL SWING THROUGH SUNDAY AS THE LOW
CROSSES NEW ENGLAND. THIS FRONT WILL ONLY BRING A SLIGHT INCREASE IN
CLOUDS AS THERE IS LITTLE DIFFERENCE BETWEEN THE AIR MASSES ON
EITHER SIDE OF THE BOUNDARY. HIGH PRESSURE WILL FILL BACK IN FOR THE
BEGINNING OF THE WORKWEEK BEFORE A STATIONARY/WARM FRONT MAY DEVELOP
OVER THE MID ATLANTIC ON TUESDAY.
TEMPERATURES WILL BE RATHER CONSISTENT THROUGH THE LONG TERM. HIGHS
WILL GENERALLY BE IN THE UPPER 60S NORTH OF I66 AND IN THE LOWER 70S
ALONG THE CENTRAL VA PIEDMONT. LOWS WILL BE IN THE MID 40S TO LOWER
50S THROUGHOUT THE TERM.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
A WARM FRONT WILL APPROACH FROM THE SOUTH TNGT. THE TERMINALS WILL
BE LOCATED IN COOL ELY FLOW AND LOW CLOUDS TNGT. CIGS PREDOMINATELY
IN IFR CAT TNGT. PERIOD OF SHRA WILL BE HEAVY AT TIMES
TNGT...RESULTING IN PERIOD OF IFR VSBYS. A FEW THUNDERSTORMS ARE
POSSIBLE ESPECIALLY AFTER 06Z.
HEAVY SHOWERS AND THUNDERSTORMS WILL CONTINUE WEDNESDAY WITH IFR
CONDITIONS. THUNDERSTORMS MAY BECOME SEVERE...WITH DAMAGING WINDS
AND ISOLATED TORNADOES BEING THE PRIMARY THREAT. THE BEST CHANCE
FOR SEVERE THUNDERSTORMS WILL BE IN THE AFTERNOON. CIGS START OFF
IN IFR BUT MAY IMPROVE TO MVFR BEHIND THE WARM FRONT. WINDS SHIFT
OUT OF THE S-SE AND INCREASE TO 15-25 KT IN WAKE OF FROPA AS WELL.
MODERATE CONFIDENCE IN SUB-VFR CONDITIONS IN HEAVY RAINFALL AND
THUNDERSTORMS WEDNESDAY NIGHT...THEN GRADUALLY IMPROVING TO VFR
THURSDAY AND PERSISTING INTO FRIDAY AS HIGH PRESSURE BUILDS.
CONFIDENCE IS LOW FOR ANY AVIATION HAZARDS IN THE LONG TERM.
&&
.MARINE...
UPGRADED TO A GALE WRNG FOR THE MD CHSPK BAY SOUTH OF SANDY POINT
AND FOR THE LWR TIDAL POTOMAC RVR THRU WED NGT. WHILE WINDS WILL
GENERALLY BE BETWEEN 20-30 KT IN THESE ZONES...HVY SHOWERS AND
STORMS WILL TRANSPORT HIGHER WINDS ALOFT DOWN TO THE SFC. ALREADY
HAD 35 KT GUSTS OCCUR AT THE LOWER HOOPER ISLAND AND BISHOPS HEAD
BUOYS LATE THIS AFTN DESPITE NO LIGHTNING. GIVEN THE HIGH
FREQUENCY OF THESE HEAVIER SHOWERS AND STORMS EXPECTED OVER THE
NEXT 36 HRS...A GALE WARNING WOULD COVER THIS THREAT. THE GALE
WARNING MAY NEED TO BE EXPANDED NWD BUT CONFIDENCE NOT HIGH ENOUGH
TO UPGRADE ATTM WITH THE NRN MARINE ZONES SITUATED DEEPER INTO
THE COOLER/STABLE SECTOR FARTHER TO THE NORTH OF THE WARM FRONT.
PREVIOUS DISCUSSION...
A WARM FRONT WILL APPROACH THE WATERS TONIGHT AND THE PRESSURE
GRADIENT WILL REMAIN STRONG AHEAD OF THE BOUNDARY. A SMALL CRAFT
ADVISORY IS IN EFFECT FOR THE WATERS DURING THIS TIME. THE SMALL
CRAFT ADVISORY CONTINUES THROUGH WEDNESDAY AS THE WARM FRONT MOVES
OVERHEAD. A GALE WARNING MAY ALSO BE NEEDED FOR PORTIONS OF THE
WATERS WEDNESDAY.
A STRONG SOUTHERLY LOW-LEVEL JET AHEAD OF A SLOW-MOVING COLD FRONT
WILL RESULT IN MODERATE TO HIGH SMALL CRAFT LEVEL GUSTS /25-30 KTS/
WEDNESDAY INTO WEDNESDAY NIGHT. GALE GUSTS ARE POSSIBLE FOR A TIME
AS WELL ON AREA WATERS...BOTH SYNOPTICALLY AND IN STRONGER
CONVECTION. SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN AND GUSTY
WINDS WILL LOCALLY REDUCE VISIBILITY AND INCREASE SEAS WEDNESDAY
INTO WEDNESDAY NIGHT. SMALL CRAFT ADVISORY GUSTS ARE LIKELY IN
NORTHWEST FLOW BEHIND THE FRONT THURSDAY AFTERNOON. QUIETER WEATHER
WILL RETURN TO THE WATERS FRIDAY. CONFIDENCE IS LOW FOR ANY MARINE
HAZARDS IN THE LONG TERM.
&&
.HYDROLOGY...
RAIN CONTINUES TO SPREAD BACK INTO THE AREA THIS EVE...WITH
CONVECTION DEVELOPING OVER SRN/CENTRAL VA. ADDITIONAL RAINFALL IS
FORECAST TO FUNNEL INTO THE AREA OVNGT. THIS PRECIPITATION WILL
BE AIDED IN ITS CONTINUED DEVELOPMENT BY THREE FACTORS...LOW-
LEVEL UPSLOPE FLOW TOWARD THE BLUE RIDGE...APPROACHING ENERGY
ALOFT...AND AN ADVANCING SURFACE WARM FRONT.
AS WARMER AND MORE MOIST AIR SURGES INTO THE REGION TONIGHT...THE
HEAVY RAIN THREAT WILL INCREASE ACCORDINGLY. PWAT VALUES ARE
EXPECTED TO EXCEED 1.5 INCHES AFTER MIDNIGHT...AND CONTINUE TO RISE
ON WEDNESDAY...PEAKING JUST BELOW 2 INCHES BY EARLY AFTERNOON.
HIRES MODELS AND THE LATEST OPERATIONAL GFS/NAM SHOW THE POTENTIAL
FOR WIDESPREAD 2-5 INCHES WITH THE LEAST EXPECTED WEST OF THE BLUE
RIDGE AND THE MOST SOMEWHERE BETWEEN THE BLUE RIDGE AND I-95
CORRIDOR.
FLASH FLOOD WATCH REMAINS IN EFFECT AREA WIDE...AND RIVER FLOOD
WATCHES ARE IN EFFECT AT SEVEN FORECAST POINTS. CONFIDENCE WAS
NOT HIGH ENOUGH TO UPGRADE ANY OF THE WATCHES TO WARNINGS THIS FAR
AHEAD OF THE EXPECTED EVENT. CONTINUE TO MONITOR THE LATEST
FORECASTS AND DISCUSSIONS...AND MONITOR FOR POTENTIAL WARNINGS.
&&
.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES ARE RUNNING AROUND 1.2 TO 1.4 FT THIS EVENING ON
CHESAPEAKE BAY...AND BETWEEN 1.5 AND 2.0 FT ON THE UPPER TIDAL
POTOMAC. WINDS WILL GRADUALLY SHIFT TO THE SE OVERNIGHT...WHICH
SHOULD KEEP ANOMALIES AT OR HIGHER THAN CURRENT LEVELS BY HIGH TIDE
IN THE MORNING. COASTAL FLOOD ADVISORIES HAVE BEEN ISSUED FOR THE
WEDNESDAY MORNING HIGH TIDE CYCLE. IT IS STILL POSSIBLE THAT
MODERATE FLOODING REQUIRING COASTAL FLOOD WARNINGS MAY BE NEEDED AT SOME
POINTS...PARTICULARLY ANNAPOLIS AND WASHINGTON DC...BUT CONFIDENCE
IS NOT HIGH ENOUGH TO WARRANT AN UPGRADE AT THIS TIME.
THE COASTAL FLOOD WATCH REMAINS IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH
THROUGH THURSDAY MORNING FOR THE WESTERN SHORE OF THE CHESAPEAKE
BAY. ANOMALIES SHOULD BE EVEN HIGHER...BEFORE A COLD FRONT CROSSES
THE WATERS AND MAYBE PUSHES SOME OF THE EXCESS WATER OUT OF THE
ESTUARY. MINOR TIDAL FLOODING IS EXPECTED FOR LOCATIONS ALONG THE
UPPER TIDAL POTOMAC RIVER.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FLASH FLOOD WATCH THROUGH LATE WEDNESDAY NIGHT FOR DCZ001.
COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR DCZ001.
COASTAL FLOOD ADVISORY FROM 7 AM TO NOON EDT WEDNESDAY FOR
DCZ001.
MD...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR MDZ003-004-501-
502.
FLASH FLOOD WATCH THROUGH LATE WEDNESDAY NIGHT FOR MDZ005>007-
009>011-013-014-016>018.
COASTAL FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
MORNING FOR MDZ007-011-014-017-018.
COASTAL FLOOD ADVISORY FROM 1 AM TO 1 PM EDT WEDNESDAY FOR
MDZ007-011-014-017-018.
VA...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR VAZ025>031-
036>040-042-050-051-501-503-504.
FLASH FLOOD WATCH THROUGH LATE WEDNESDAY NIGHT FOR VAZ052>057-
502.
COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR VAZ053-
054.
COASTAL FLOOD ADVISORY FROM 7 AM TO NOON EDT WEDNESDAY FOR
VAZ053-054.
WV...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR WVZ050>053-055-
501>506.
MARINE...GALE WARNING UNTIL 6 AM EDT THURSDAY FOR ANZ532>534-537-
540>543.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ530-531-
535-536-538-539.
&&
$$
SYNOPSIS...JRK/BJL
NEAR TERM...JRK/BJL
SHORT TERM...DFH
LONG TERM...CEB
AVIATION...JRK/BJL/CEB/DFH
MARINE...JRK/BJL/CEB/DFH
HYDROLOGY...JRK/JCE
TIDES/COASTAL FLOODING...KCS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
423 PM EDT MON APR 28 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 423 PM EDT MON APR 28 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER
LEVEL TROUGH FROM THE NRN ROCKIES TO THE CENTRAL PLAINS AND MID MS
VALLEY. DOWNSTREAM A RIDGE EXTENDED FROM THE MID ATLANTIC THROUGH
THE ERN LAKES TO WRN HUDSON BAY. AT THE SFC...GUSTY EAST WINDS
PREVAILED AS A RESULT OF A TIGHT PRES GRADIENT BETWEEN STRONG HIGH
PRES OVER HUDSON BAY AND A LOW OVER ERN NEBRASKA. A BAND OF RAIN
OVER NRN WI SUPPORTED BY 295K-300K ISENTROPIC LIFT WAS MAKING VERY
SLOW PROGRESS IN LIFTING TO THE NORTH AS IT ENCOUNTERS IT ENCOUNTERS
DRY EASTERLY FLOW (BELOW 800 MB) TO THE NORTH AND EAST...PER 12Z APX
SOUNDING.
SOME PCPN MAY DEVELOP ALONG THE WI BORDER THIS EVENING BUT SINCE IT
SHOULD BE RELATIVELY LIGHT...MAINLY SPRINKLES...ONLY CHANCE POPS
WERE INCLUDED. AS THE MID LEVEL LOW WOBBLES TO THE NORTHEAST AND A
SHORTWAVE LIFTS NORTH INTO UPPER MI...EXPECT WIDESPREAD PCPN TO
SPREAD INTO THE SOUTH LATE TONIGHT AND ACROSS THE REST OF THE CWA
TUE MORNING. THE PCPN IS EXPECTED TO TAPER OFF FROM SSE TO NNW BY
MID TO LATE AFTERNOON. THE REGION WILL FALL UNDER THE TROWAL REGION
NORTH OF THE MID/UPPER LOW...PER MODELS 310-320 THETA-E LAYER.
ALTHOUGH MOST AREAS SHOULD SEE QPF AMOUNTS IN THE 0.50 TO .75 INCH
RANGE...THE STRONGEST LIFT AND MOISTURE INFLOW IS EXPECTED OVER THE
SE CWA WHERE QPF COULD EXCEED AN INCH THROUGH TUE. UPSLOPE NE FLOW
INTO N CNTRL UPPER MI COULD ALSO SUPPORT RELATIVELY HIGHER PCPN
AMOUNTS.
UNCERTAINTY REMAINS WITH THE PCPN TYPE OVER THE HIGHER TERRAIN OF
THE WRN HALF OF UPPER MI. THE 12Z NAM LOW LEVEL THICKNESS AND
WET-BULB ZERO HEIGHTS SUGGEST THAT SNOW MAY BE THE PREDOMINATE PCPN
TYPE OVER THE INTERIOR...AND ESPECIALLY OVER THE HIGHER TERRAIN OF
THE WRN THIRD TOWARD IWD. EVEN WITH THE HIGH QPF AMOUNTS...VERY LOW
SLR VALUES AND RELATIVELY WARM ROAD SURFACES SHOULD MINIMIZE ANY
ACCUMULATIONS WITH SNOW AMOUNTS ONLY TO AROUND AN INCH EXPECTED ON
GRASSY OR SNOW COVERED AREAS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 423 PM EDT MON APR 28 2014
MUCH OF THE LONG TERM FORECAST WILL DEAL WITH THE UPPER LOW
CURRENTLY OVER THE CENTRAL CONUS THAT WILL GRADUALLY LIFT NORTHEAST
THROUGH MUCH OF THE REST OF THE WORK WEEK. THE STRONGEST WAVE OF
PRECIPITATION WILL MOVE NORTH THROUGH THE AREA ON TUESDAY AND
SHOULD BE SITUATED OVER WESTERN LAKE SUPERIOR AND THE WESTERN THIRD
OF THE U.P. AT THE START OF THE LONG TERM PERIOD. THIS WILL CONTINUE
TO ROTATE NORTHWEST TUESDAY NIGHT AND LEAD TO A LITTLE BIT OF A
BREAK ON THE PRECIPITATION FOR TUESDAY EVENING OVER THE
CENTRAL/EAST. AS THE SURFACE LOW MOVES UP INTO THE
GREAT LAKES REGION...A MID LEVEL TROUGH WILL SLIDE NORTH THROUGH
THE AREA LATE TUESDAY NIGHT THROUGH WEDNESDAY. THINK THE
HEAVIEST PRECIP WOULD BE OVER THE EAST THIRD...BUT STILL WOULD
EXPECT SCATTERED/NUMEROUS SHOWERS OVER THE WEST/CENTRAL. BETTER DEEP
MOISTURE SHIFTS OVER THE WESTERN LAKE AFTER THAT...AND WILL LIKELY
LEAD TO A MORE SCATTERED NATURE TO THE SHOWERS. THIS WILL CONTINUE
THROUGH THE FIRST PART OF THE WEEKEND AS THE AS THE UPPER LOW SPINS
AND BROADENS/WEAKENS. THUS...WILL CONTINUE TO SHOW A GRADUAL
DECREASING TREND TO THE POPS. WITH THE POTENTIAL FOR WEAK
DISTURBANCES ROTATING THROUGH...THERE MAY BE PERIODS WHERE POPS NEED
TO BE BUMPED UP...BUT PINNING THOSE DOWN AT THIS TIME IS TOO
DIFFICULT.
AS FOR PRECIP TYPE...SHOULD BE ENOUGH WARM AIR WRAPPING IN DURING
THE DAY TOMORROW TO CHANGE THE PRECIP OVER TO RAIN OVER MUCH OF THE
AREA BY TUESDAY EVENING (EXCEPT FOR A LINGERING MIX NEAR IRONWOOD).
THE WARM AIR CONTINUES TO MOVE WEST AROUND THE LOW (REMAINING AROUND
2-4C AT 850MB) THROUGH WEDNESDAY EVENING AND WILL KEEP EVERYTHING
AS RAIN. THEN AS THE FLOW STARTS TO BECOME A LITTLE MORE NORTHERLY
ON WEDNESDAY NIGHT AND INTO THURSDAY...TEMPERATURES ALOFT BEGIN TO
COOL FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA AND COULD LEAD TO A
TRANSITION TO TO MORE OF A RAIN/SNOW MIX HEADING INTO
THURSDAY/FRIDAY. OPTED TO FOLLOW THE GENERAL IDEA SHOWN BY THE
1000-850MB THICKNESS AND WETBULB0 HEIGHTS THROUGH THE FORECAST
PERIOD SINCE IT WAS LARGELY DEALING WITH A NEAR SURFACE WARM
LAYER. DID PUT IN SOME FOG FOR THE FAVORED UPSLOPE HIGHER TERRAIN
LOCATIONS OF THE CENTRAL/NORTH-CENTRAL ON TUESDAY NIGHT INTO
WEDNESDAY WITH THE FAVORABLE EASTERLY UPSLOPE FLOW OF MOIST AIR.
ELSEWHERE...WOULD EXPECT IT TO BE JUST A LOW STRATUS DECK. ALL IN
ALL...LOOKS TO BE A COOL/CLOUDY/SHOWERY PERIOD THROUGH THE FIRST
HALF OF THE WEEKEND.
UPPER TROUGH/LOW FINALLY SHIFTS EAST OF THE AREA FOR THE SECOND
HALF OF THE WEEKEND...BUT MODELS DIFFER ON EVOLUTION OF THE UPPER
LEVEL PATTERN AT THAT POINT. THE GENERAL IDEA IS FOR MORE ZONAL
FLOW OR WEAK UPPER LEVEL RIDGING TO DEVELOP OVER THE NORTH-CENTRAL
CONUS...WHICH SHOULD LEAD TO A LITTLE DRIER PERIOD THAN SEEN THIS
WEEK. THERE ARE HINTS IN THE 12Z GEM/GFS/ECMWF THAT A WEAK
DISTURBANCE WILL SHIFT EAST ACROSS THE AREA ON SUNDAY AND BRING SOME
SHOWERS. OTHERWISE...MONDAY IS LOOKING LIKE IT MAY END UP DRY WITH
THE WEAK UPPER RIDGE SHIFTING CLOSER TO THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 135 PM EDT MON APR 28 2014
VFR CONDITIONS WILL PREVAIL UNTIL LATE TONIGHT. THERE COULD BE SOME
INTERMITTENT LIGHT RAIN/SPRINKLES AT KIWD THIS MORNING BUT OTHERWISE
MID CLOUDS AND VFR CONDITIONS WILL PREVAIL. INCREASING MOISTURE AHEAD
OF A WARM FRONT WILL BRING AN INCREASING CHANCE OF RAIN RAIN LATE
TONIGHT AT ALL TAF SITES AS CIGS LOWER TO MVFR. A MIX OF RAIN AND
SNOW WILL MOVE IN DURING THE MORNING WITH CIGS LIKELY LOWERING INTO
THE IFR RANGE WITH VSBY REMAINING MVFR. THE BEST CHANCE FOR SNOW
WILL BE OVER THE WEST TOWARD CMX AND ESPECIALLY IWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 PM EDT MON APR 28 2014
EAST TO NORTHEAST GALES ARE EXPECTED TO CONTINUE OVER THE WRN
PORTION OF LAKE SUPERIOR THROUGH TUE INTO TUE EVENING AS A RESULT OF
THE STRONG PRES GRADIENT BTWN A DEEP LOW OVER ERN NEBRASKA AND A
STRONG HIGH OVER HUDSON BAY. ENE GALES TO 35 KNOTS ARE ALSO POSSIBLE
CENTRAL LAKE SUPERIOR TUE BUT SINCE THERE WAS STILL UNCERTAINTY
WHETHER THE 30 KNOTS WINDS WILL INCREASE TO GALES...THE WATCH WAS
RETAINED FOR THIS LOCATION. THE WINDS WILL DIMINISH TUE EVENING AS
THE LOW LIFTS TO THE NORTH TOWARD THE WRN GREAT LAKES AND THE PRES
GRADIENT WEAKENS. HOWEVER WINDS TO 30 KNOTS ARE STILL EXPECTED UNTIL
LATE TUE NIGHT. WINDS ARE EXPECTED TO DROP OFF TO 25 KNOTS OR LESS
FROM WED INTO FRI AS THE LOW FILLS AND REMAINS NEAR UPPER MICHIGAN.
&&
.HYDROLOGY...
ISSUED AT 423 PM EDT MON APR 28 2014
RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH
THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA
STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR
ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR
CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON
RIVER NEAR NAHMA JUNCTION. AT LEAST THROUGH TUESDAY MORNING THESE
RIVERS ARE NOT EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER
RIVERS WILL START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE
SYSTEM AND WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL
LIQUID EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES
BY THURSDAY. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK. WHILE
WIDESPREAD AND AREAL FLOODING IS NOT EXPECTED...RFC ENSEMBLE
FORECASTS DO SHOW SIGNIFICANT RISES ON A FEW OF THE RIVERS IF
HIGHER QPF FROM THE MODELS VERIFIES. THOSE LIVING AROUND
RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS
WEEK.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR
LSZ264>266.
GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ TUESDAY FOR LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
HYDROLOGY...SRF/TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
136 PM EDT MON APR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 511 AM EDT MON APR 28 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER
LEVEL TROUGH FROM THE NW CONUS THROUGH THE CENTRAL PLAINS WITH A
CLOSED LOW OVER NEBRASKA. DOWNSTREAM A RIDGE EXTENDED FROM THE SE
CONUS THROUGH WRN LAKES INTO MANITOBA. AT THE SFC...A BRISK ERLY
FLOW PREVAILED THROUGH THE NRN LAKES BETWEEN HIGH PRES OVER HUDSON
BAY AND A DEEP LOW OVER ERN NEBRASKA. ISENTROPIC ASCENT AS NOTED ON
THE 295K SFC HAS PRODUCED SEVERAL BANDS OF LIGHT PCPN OVER UPPER MI
THIS MORNING BUT THIS PCPN HAS FALLEN MAINLY AS JUST
SPRINKLES/FLURRIES AS IT ENCOUNTERS VERY DRY AIR BELOW 750 MB.
TODAY...MODELS CONSISTENT SHOWING SYSTEM OVER ERN NEBRASKA STALLING
AND BEGINNING TO OCCLUDE TODAY. MODELS SHOW WEAKENING ISENTROPIC
ASCENT OVER UPR MI AND A LACK OF 850-700 MB MOISTURE ADVECTION INTO
THE REGION. THIS FACT ALONG WITH MID-LVL RDG GENERALLY STAYING IN
PLACE SHOULD KEEP MUCH OF THE CWA DRY TODAY. INCREASING 850-700 MB
MOISTURE ADV AND ISENTROPIC ASCENT COULD BRING IN A BETTER CHC OF
RAIN TOWARD 00Z THIS EVENING OVER MAINLY FAR SCNTRL CWA.
TONIGHT...MODELS SHOW MORE SUBSTANTIAL SHORTWAVE LOBE ROTATING
NORTHWARD AHEAD OF PLAINS CLOSED LOW WHICH IN TURN WILL PROPEL 850
MB WARM FRONT NORTHWARD INTO THE SE CWA LATE TONIGHT. INCREASING
ISENTROPIC ASCENT AND 850-700 MB MOISTURE ADVECTION SPREADING IN
FROM THE SSE AHEAD OF THE WARM FRONT WILL BRING INCREASING RAIN CHCS
INTO SCNTRL CWA THIS EVENING SPREADING INTO THE REST OF THE SE HALF
OF THE CWA OVERNIGHT TONIGHT. THICKNESS VALUES AND SOUNDINGS SUGGEST
SNOW MAY MIX WITH RAIN OVER NCNTRL AND NW CWA LATE TONIGHT BUT PCPN
SHOULD BE LIGHT THAT ANY SNOW AMTS WILL HAVE LITTLE IMPACT ON TRAVEL.
MODEL QPF INDICATES SCNTRL CWA COULD SEE FROM .25 TO PERHAPS .75 OF
AN INCH OF RAINFALL TONIGHT WHICH WILL ADD TO RUNOFF FOR AREA STREAMS
AND RIVERS INTO MIDWEEK.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM EDT MON APR 28 2014
FOCUSED ATTENTION ON TUE-WED NIGHT TIME FRAME AS MOST SIGNIFICANT
PRECIP IS EXPECTED DURING THAT TIME.
THE SETUP FOR MID WEEK IS QUITE INTERESTING ACROSS THE CONUS AS A
DEEP CLOSED UPPER LOW IS OVER THE CENTRAL CONUS...BORDERED ON THE
W...N AND E BY AMPLIFIED UPPER RIDGING. ALSO...AT THE START OF THE
LONG TERM /12 TUE/...THE UPPER LOW WILL BE ABSORBING A WEAK UPPER
LOW THAT ORIGINATED OVER QUEBEC. THE SYSTEM WILL BE QUITE WRAPPED
UP...WITH GREAT MOISTURE TRANSPORT FROM BOTH THE GULF OF MEXICO AND
THE ATLANTIC THAT FOCUSES OVER THE LOWER GREAT LAKES BEFORE
WRAPPING W ACROSS THE CWA AND EVENTUALLY TO THE W OF THE LOW /WHICH
IS OVER IA AT 12Z TUE/. PRECIP TUE WILL BE PRIMARILY FORCED BY
50-60KT 900-700MB WINDS...RESULTING IN GOOD MOISTURE TRANSPORT IN
THIS LAYER AS WELL AS STRONG ISENTROPIC ASCENT AS ISENTROPIC
SURFACES INCREASE IN HEIGHT BY AROUND 1KM FROM UPSTREAM TO
DOWNSTREAM ACROSS THE CWA. PWAT VALUES WILL BE 0.75-1.00 INCHES...OR
GENERALLY 150-200 PERCENT OF NORMAL. ANOTHER SIGNIFICANT FORCING
MECHANISM IS A SHORTWAVE THAT MODELS SHOW MOVING ACROSS THE CWA
TUE...WHICH LEADS TO STEEP 700-500MB LAPSE RATES OF JUST OVER 7C/KM.
ADDITIONALLY...THE LEFT EXIT REGION OF AN UPPER JET WILL BE ACROSS
THE CWA. ALL THESE INGREDIENTS COME TOGETHER TO PRODUCE SIGNIFICANT
QPF AMOUNTS FROM THE MODELS LATE MON NIGHT INTO TUE. THE MOST PRECIP
SHOULD FALL NEAR LAKE MICHIGAN WHERE THE BEST FORCING AND MOISTURE
IS EXPECTED. EVEN THE LOWER RES MODELS /THAT TYPICALLY DO NOT
PERFORM AS WELL IN THIS TYPE OF SITUATION/ HAVE UP TO AN INCH OF QPF
NEAR LAKE MICHIGAN...WHILE THE NAM HAS THE MOST QPF AT 2.25 INCHES.
WILL GO WITH A CONSENSUS APPROACH OF GFS/ECMWF AND REGIONAL GEM
/WHICH HAS UP TO 1.85 INCHES/...WHICH INCORPORATES MON NIGHT /SHORT
TERM/. THE ECMWF/GFS HAVE THE BEST PRECIP LATE MON NIGHT INTO TUE
MORNING...WHILE THE NAM HAS THE BEST PRECIP ON TUE. THE REGIONAL GEM
IS BETWEEN THE NAM AND GFS/ECMWF. A COMPLICATING FACTOR TO THIS TIME
FRAME IS THAT MODEL TEMP PROFILES FAVOR PRECIP TO BE SNOW OVER WRN
UPPER MI AND RAIN NEAR LAKE MICHIGAN AND E...WITH A MIX BETWEEN. DUE
TO SFC TEMPS BEING NEAR OR ABOVE FREEZING AND STRONG SOLAR EFFECTS
THIS TIME OF YEAR...ACCUMULATIONS ON PAVED SURFACES SHOULD BE
MINIMAL...BUT GRASSY SURFACES OVER THE HIGHER TERRAIN OF WRN UPPER
MI COULD SEE 2-3 INCHES OF SNOW. GIVEN VERY MINIMAL EXPECTED IMPACTS
TO TRAVEL...WILL CONTINUE TO NOT MENTION SNOW IN THE HWO. DEPENDING
ON EXACT PRECIP AMOUNTS...COULD SEE SOME SIGNIFICANT RISES ON AREA
RIVERS.
ANOTHER SHOT AT GOOD ISENTROPIC ASCENT AND A STRONG SHORTWAVE ARE
SHOWN BY MODELS FOR WED AS THE UPPER LOW CONTINUES TO WEAKEN AND
BEGINS MOVING NE TOWARD THE CWA. SIGNALS FOR PRECIP AMOUNTS AND
TRENDS ARE A LOT MORE MUDDLED ON WED INTO WED NIGHT AS THE CWA WILL
BE MORE REMOVED FROM THE BEST MOISTURE TRANSPORT...WHICH WILL BE
MORE FOCUSED E AND N OF THE CWA. THINK THAT MUCH OF THE CWA WILL SEE
PRECIP...WITH POTENTIAL FOR UP TO AN INCH OF ADDITIONAL PRECIP
DURING THIS TIME PERIOD. USED A BROAD CONSENSUS OF GUIDANCE DURING
THIS PERIOD.
THE UPPER LOW WILL CONTINUE TO WEAKEN AND MOVE SLOWLY NE INTO LATE
WEEK BEFORE ADDITIONAL UPPER LEVEL ENERGY MOVES INTO THE REGION LATE
THIS WEEK INTO THE WEEKEND...LEADING TO CONTINUED WET WEATHER...BUT
AMOUNTS WILL BE LOWER THROUGH THE REST OF THE WEEK. USED A CONSENSUS
OF GUIDANCE FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 135 PM EDT MON APR 28 2014
VFR CONDITIONS WILL PREVAIL UNTIL LATE TONIGHT. THERE COULD BE SOME
INTERMITTENT LIGHT RAIN/SPRINKLES AT KIWD THIS MORNING BUT OTHERWISE
MID CLOUDS AND VFR CONDITIONS WILL PREVAIL. INCREASING MOISTURE AHEAD
OF A WARM FRONT WILL BRING AN INCREASING CHANCE OF RAIN RAIN LATE
TONIGHT AT ALL TAF SITES AS CIGS LOWER TO MVFR. A MIX OF RAIN AND
SNOW WILL MOVE IN DURING THE MORNING WITH CIGS LIKELY LOWERING INTO
THE IFR RANGE WITH VSBY REMAINING MVFR. THE BEST CHANCE FOR SNOW
WILL BE OVER THE WEST TOWARD CMX AND ESPECIALLY IWD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 511 AM EDT MON APR 28 2014
EAST TO NORTHEAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE
DEEPENS OVER THE PLAINS. EXPECT ENE GALES TO 35KTS OVER MUCH OF WRN
LAKE SUPERIOR INTO TUE MORNING. THERE IS ALSO A CHANCE FOR ENE GALES
TO 35 KNOTS OVER CENTRAL LAKE SUPERIOR FOR LATE TONIGHT INTO TUE SO
HAVE ISSUED A GALE WATCH FOR LSZ264-266 WINDS SHOULD GRADUALLY
DIMINISH LATE TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH
TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER
WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE EVENING. WINDS ARE
EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED INTO FRI AS THE
LOW FILLS AND REMAINS NEAR UPPER MICHIGAN.
&&
.HYDROLOGY...
ISSUED AT 358 AM EDT MON APR 28 2014
RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH
THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA
STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR
ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR
CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER
NEAR NAHMA JUNCTION. AT LEAST THROUGH TONIGHT THESE RIVERS ARE NOT
EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER RIVERS WILL
START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE SYSTEM AND
WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL LIQUID
EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES BY
THURSDAY. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK. WHILE
WIDESPREAD AND AREAL FLOODING IS NOT EXPECTED...RFC ENSEMBLE
FORECASTS DO SHOW SIGNIFICANT RISES ON A FEW OF THE RIVERS IF HIGHER
QPF FROM THE MODELS VERIFIES. THOSE LIVING AROUND
RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS WEEK.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR
LSZ264>266.
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ TUESDAY FOR LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...JLB
MARINE...VOSS
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1258 PM EDT MON APR 28 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 325 AM EDT MON APR 28 2014
AN EXPANSIVE AND STRONG SYSTEM CENTERED ACROSS THE CENTRAL PLAINS
STATES WILL DRIVE RAINFALL INTO THE AREA AHEAD OF AN ASSOCIATED
FRONTAL SYSTEM TO OUR SOUTH. COOL AND WINDY CONDITIONS CAN BE
EXPECTED TODAY WITH AN INCREASING CHANCE OF RAIN. RAIN WILL CONTINUE
INTO EARLY TUESDAY BEFORE THE RAIN MOVES NORTH AND A SHORT PERIOD OF
WARMER AIR MOVES IN ACROSS THE AREA. ADDITIONAL SHOWERS AND STORMS
WILL BE POSSIBLE TUESDAY AND WEDNESDAY AS ADDITIONAL WAVES OF LOW
PRESSURE MOVE THROUGH THE AREA. COOLER CONDITIONS WILL THEN RETURN
FOR LATE THIS WEEK ALONG WITH A CONTINUED CHANCE OF RAIN SHOWERS.
&&
.UPDATE...
ISSUED AT 1256 PM EDT MON APR 28 2014
FORECASTS WILL BE UPDATED TO ACCOUNT FOR LESS RAIN THIS AFTERNOON.
THE BAND OF RAIN CONTINUES TO DIMINISH...SO I LOWERED POPS. SOME
BREAKS IN THE CLOUDS SHOWING UP AS WELL...THUS I FEATURED LESS
CLOUD COVER AS WELL. WITH ADDED HEATING...MIXING HEIGHTS WILL
INCREASE. THUS IT WILL REMAIN WINDY THROUGH THE AFTERNOON.
UPDATE ISSUED AT 1056 AM EDT MON APR 28 2014
WILL KEEP THE WIND ADVISORY GOING. WHILE OBS ARE MOSTLY BELOW
CRITERIA...THE MODELS SUGGEST MIXING HEIGHTS WILL INCREASE EARLY
THIS AFTERNOON AS THE LOW LEVEL JET STRENGTHENS. WE ARE ALSO
SEEING SOME POWER OUTAGES SHOWING UP ON THE CONSUMERS WEBSITE.
THE BAND OF SHOWERS MOVING IN FROM THE SOUTH CONTINUES TO WEAKEN.
WHILE MOST LOCATIONS WILL SEE SOME PRECIPITATION...WHAT DOES FALL
TH IS AFTERNOON SHOULD BE LIGHT. SO I FEATURES LIGHT RAIN
SHOWERS...AND TONED BACK THE THUNDER WORDING. MODELS SHOWING NO
INSTABILITY THROUGH 00Z TUE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 325 AM EDT MON APR 28 2014
THE MAIN CHANGE WITH THIS FCST PACKAGE IS TO EXPAND THE WIND
ADVISORY TO THE EAST THROUGH THE REMAINDER OF THE CWFA FOR TODAY.
OTHERWISE...THE FCST REMAINS MAINLY ON TRACK WITH A SLIGHTLY SLOWER
TREND TO THE RAIN MOVING IN FOR TODAY.
REGARDING THE EXPANSION OF THE WIND ADVISORY FIRST...WINDS REMAIN
RATHER BRISK AND THIS EARLY MORNING HOUR ACROSS THE CWFA. SOME GUSTS
OF AROUND 30 KNOTS ARE ALREADY OCCURRING THIS MORNING...AND THIS
WILL ONLY INCREASE DURING THE DAYLIGHT HOURS AS THE GRADIENT
TIGHTENS MORE AND AS DIURNAL MIXING WILL HELP TO BRING SOME OF THE
STRONGER WINDS DOWN FROM ALOFT. IT SEEMS THAT 40 KNOTS SHOULD BE
PRETTY EASY TO MIX DOWN...EVEN IN A WAA PATTERN.
AS FAR AS THE RAINFALL IS CONCERNED...THE TREND OVER THE PAST 24
HOURS IS THAT OF A SLOWER ONE WITH THE FEED OF DRY AIR COMING IN ON
THE BRISK ERLY WINDS AND HELPING TO DIMINISH MOST ALL PCPN TRYING TO
MOVE IN. THE UPPER RIDGE AXIS THAT IS ONLY SLOWLY CRAWLING EASTWARD
ACROSS THE CWFA IS FAR ENOUGH EAST AT THIS TIME THAT ENOUGH MOISTURE
TRANSPORT IS OCCURRING AND A COUPLE OF SPRINKLES/LIGHT SHOWERS ARE
OCCURRING ACROSS THE FAR SW CORNER OF THE CWFA. WE DO EXPECT THAT
PCPN WILL BE ON THE INCREASE TODAY FROM SW TO NE AS THE UPPER LOW
ROTATES A LITTLE CLOSER. THUNDER IS STILL POSSIBLE ACROSS THE FAR
SOUTH THIS AFTERNOON AS SLIGHTLY NEGATIVE ELEVATED LI/S MOVE UP INTO
THE AREA. SEVERE WX IS NOT EXPECTED AT THIS TIME WITH NO SFC
INSTABILITY EXPECTED THROUGH TONIGHT.
THE BEST THREAT OF RAIN SHOWERS AND STORMS LOOKS TO COME THIS
EVENING AND INTO THE OVERNIGHT HOURS. THE BEST MOISTURE AXIS PASSES
FROM SOUTH TO NORTH DURING THIS TIME FRAME...OUT AHEAD OF THE
OCCLUDED FRONT. WE CONTINUE TO EXPECT LITTLE THREAT OF SEVERE STORMS
TONIGHT ONCE AGAIN AS THE INSTABILITY WILL ONCE AGAIN BE ELEVATED.
THE RAIN CHANCES WILL THEN DIMINISH LATE TONIGHT AND EARLY TUE
MORNING AS THE MOISTURE TRANSPORT AND LLJ PEEL OFF TO THE EAST OF
THE STATE.
WE CONTINUE TO LOOK FOR A BRIEF WARM UP FOR THE DAY ON TUE WITH 70
DEGREE TEMPERATURES LOOKING MORE LIKELY. THE FRONT WILL BE NEAR THE
SRN STATE BORDER AT 12Z ON TUE. THE UPPER LOW COMING IN FROM THE
WEST WILL PUSH THE FRONT NORTH THROUGH THE AREA. EVEN THOUGH IT WILL
NOT BE THE TRUE WARM SECTOR...H850 TEMPS ARE STILL VERY MILD...AND
WILL WE TAP THAT WARMTH AS THE DRY SLOT MOVES IN AND WE GET SOME
SUN. H850 TEMPS AROUND +10 C WILL SUPPORT MANY LOCATIONS HITTING 70.
IT DOES LOOK LIKE LATE IN THE AFTERNOON WE WILL SEE CONVECTION TRY
TO FIRE OVERHEAD AS A WAVE ROTATES AROUND THE UPPER LOW AND MOVES
TOWARD THE AREA.
THERE IS SOME CONCERN WITH CONVECTION FIRING ON TUE AFTERNOON AS
STRONG JET STREAM WINDS WILL STILL BE OVERHEAD ACROSS SE LOWER.
THIS WILL PROVIDE FOR GOOD SHEAR IN THE DEEP LAYER. MUCH BETTER
INSTABILITY /LI/S OF -6 TO -8C/ WILL BE FOUND FURTHER SE ALSO.
WE STAY RELATIVELY WARM THROUGH MOST OF WED AS THE LOW LEVEL COLD
AIR DOES NOT COME IN UNTIL LATE WED AFTERNOON AND WED EVENING. THIS
IS THE CASE AS THE UPPER LOW HELPS ANOTHER WAVE TOWARD THE AREA AND
THE FLOW AHEAD OF IT WILL CONTINUE TO SUPPORT WARM TEMPS UNTIL THE
LOW MOVES THROUGH LATE WED. SHOWERS AND STORMS WILL REMAIN POSSIBLE
AHEAD OF THIS WAVE FOR TUE NIGHT AND WED. WE WILL LIKELY NOT REACH
70 AGAIN...BUT WE SHOULD BE WELL INTO THE 60S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 325 AM EDT MON APR 28 2014
LITTLE QUESTION OCCASIONAL SHOWERS AND COOLER THAN NORMAL
TEMPERATURES WILL PREVAIL THROUGH SATURDAY AS WE REMAIN ON THE
CYCLONIC SIDE OF THE UPPER JET WITH A FAIR AMOUNT OF DEEP MOISTURE.
SOME QUESTION ARISES WHAT HAPPENS FROM SUNDAY AND BEYOND SO I KEEP
THE LOW CHANCE POP FOR SUNDAY BUT IT MAY BE WE ACTUALLY GET TO SEE
THE SUN ONCE AGAIN BY SUNDAY AS THE UPPER JET MAY FINALLY LIFT NORTH
OF LOWER MICHIGAN MY THEN.
MODEL CONTINUE TO BE IN GOOD AGREEMENT WITH THE CLOSED UPPER LOW
REMAINING IN PLACE INTO AS LEAST SATURDAY. THE 500 MB HEIGHT
ANOMALIES ARE ON THE ORDER OF 2-3 STD BELOW NORMAL INTO SATURDAY
OVER THE LOWER GREAT LAKES. 850 MB TEMPERATURES ARE 1 TO 2 STD BELOW
NORMAL INTO SATURDAY.
THE MODELS CONTINUE TO FEATURE THAT ARCTIC JET STREAK FEEDING INTO
THE SYSTEM FRIDAY INTO SATURDAY. THAT WILL MAINTAIN THIS PATTERN
INTO SATURDAY FOR SURE. FROM SUNDAY ON THERE IS A QUESTION OF
WHETHER ANOTHER PACIFIC SYSTEM CAN BREAK THROUGH THE WESTERN RIDGE
TO PUSH THIS PATTERN OUT OF THE WAY OR IF WE WILL CONTINUE TO SEE
MORE IN A SERIES OF NORTHERN STREAM OF SYSTEMS. I KEEP LOW CHANCE
POPS FOR SUNDAY JUST IN CASE THE LATER OCCURS.
AS FOR THE SHOWERS WEDNESDAY NIGHT THROUGH SATURDAY AFTERNOON...
GIVEN THE DEEP CYCLONIC FLOW...DEEP MOISTURE AND SATURATED DGZ PLUS
SURFACE CONVERGENCE ALONG THE LAKE MICHIGAN SHORE AREAS INTO
SATURDAY I HAVE TO BELIEVE WE WILL CONTINUE TO SEE LIGHT SHOWER
THROUGH THIS ENTIRE PERIOD. I HAVE CONTINUED THE LIKELY POPS INTO
FRIDAY AND HIGH CHANCE INTO SATURDAY. TEMPERATURES WILL BE BETWEEN 5
AND 10 DEGREES BELOW NORMAL THROUGH THIS PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 741 AM EDT MON APR 28 2014
OUR MAJOR QUESTION IS WHEN WILL THE RAIN ARRIVE AND MORE THAN THAT
WHEN WILL THE MVFR/IFR CIGS/VSBY MOVE IN AS THE STORM TO OUR
SOUTHWEST SLOWLY MOVES TOWARD THE REGION. THE HUDSON BAY HIGH
CONTINUES TO FEED VERY DRY AIR FROM THE EAST AND IT WILL CONTINUE
TO ERROD THE RAIN AS MOVES INTO SOUTHWEST MICHIGAN. THIS IS NOT TO
SAY THERE WILL NOT BE SOME LIGHT RAIN SHOWERS BUT IT SEEMS THE
BULK OF THE SIGNIFICANT RAIN WILL LARGELY STAY NEAR AND SOUTH OF
INTERSTATE 94 TODAY (USING THE RAP13 MODEL AND HRRR ).
I DID BRING THE SHOWERS INTO THE AZO...BTL AND JXN BY LATE MORNING
BUT I DID NOT BRING THOSE SHOWERS INTO GRR...MKG AND LAN TILL LATE
AFTERNOON... EVEN THEN VSBY SHOULD BE VFR FOR THE MOST PART. I PUT
VCSH AT ALL THE TAF SITES DURING THE MID MORNING HOURS SINCE
SHOWERS WILL BE AROUND BUT VERY LIGHT (MOSTLY SPRINKLES).
THE MVFR CIGS/VSBY SHOULD REACH THE I-94 TAT SITES BY LATE
AFTERNOON THEN SPREAD INTO THE I-96 SITES AFTER 00Z. ANY
THUNDERSTORM ACTIVITY SHOULD HOLD OFF UNTIL TUESDAY.
&&
.MARINE...
ISSUED AT 1056 AM EDT MON APR 28 2014
GALE WARNING TO CONTINUE. SOME GUSTS OVER GALE FORCE ALREADY
OBSERVED. WINDS LIKELY TO INCREASE AS THE LOW LEVEL JET
STRENGTHENS AND MIXING HEIGHTS INCREASE.
&&
.HYDROLOGY...
ISSUED AT 241 PM EDT SUN APR 27 2014
I DOWNPLAYED THE QPF THROUGH TUE. THE DRY AIRMASS CURRENTLY IN
PLACE SHOULD ACT TO DELAY THE ARRIVAL OF THE SHOWERS. MODELS ARE
GENERALLY SHOWING A DIMINISHING TREND TO THE INITIAL BAND OF
SHOWERS DURING THE DAY ON MONDAY. STILL LOOKS LIKE ENOUGH RAIN TO
CAUSE RIVER RISES. ANOTHER BATCH OF RAIN TUE NIGHT INTO WED MAY BE
HEAVY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ037>040-043>046-
050>052-056>059-064>067-071>074.
LM...GALE WARNING UNTIL 8 AM EDT TUESDAY FOR LMZ844>849.
&&
$$
UPDATE...MJS
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...MJS
MARINE...MJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1101 AM EDT MON APR 28 2014
LATEST UPDATE...
UPDATE/MARINE
.SYNOPSIS...
ISSUED AT 325 AM EDT MON APR 28 2014
AN EXPANSIVE AND STRONG SYSTEM CENTERED ACROSS THE CENTRAL PLAINS
STATES WILL DRIVE RAINFALL INTO THE AREA AHEAD OF AN ASSOCIATED
FRONTAL SYSTEM TO OUR SOUTH. COOL AND WINDY CONDITIONS CAN BE
EXPECTED TODAY WITH AN INCREASING CHANCE OF RAIN. RAIN WILL CONTINUE
INTO EARLY TUESDAY BEFORE THE RAIN MOVES NORTH AND A SHORT PERIOD OF
WARMER AIR MOVES IN ACROSS THE AREA. ADDITIONAL SHOWERS AND STORMS
WILL BE POSSIBLE TUESDAY AND WEDNESDAY AS ADDITIONAL WAVES OF LOW
PRESSURE MOVE THROUGH THE AREA. COOLER CONDITIONS WILL THEN RETURN
FOR LATE THIS WEEK ALONG WITH A CONTINUED CHANCE OF RAIN SHOWERS.
&&
.UPDATE...
ISSUED AT 1056 AM EDT MON APR 28 2014
WILL KEEP THE WIND ADVISORY GOING. WHILE OBS ARE MOSTLY BELOW
CRITERIA...THE MODELS SUGGEST MIXING HEIGHTS WILL INCREASE EARLY
THIS AFTERNOON AS THE LOW LEVEL JET STRENGTHENS. WE ARE ALSO
SEEING SOME POWER OUTAGES SHOWING UP ON THE CONSUMERS WEBSITE.
THE BAND OF SHOWERS MOVING IN FROM THE SOUTH CONTINUES TO WEAKEN.
WHILE MOST LOCATIONS WILL SEE SOME PRECIPITATION...WHAT DOES FALL
TH IS AFTERNOON SHOULD BE LIGHT. SO I FEATURES LIGHT RAIN
SHOWERS...AND TONED BACK THE THUNDER WORDING. MODELS SHOWING NO
INSTABILITY THROUGH 00Z TUE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 325 AM EDT MON APR 28 2014
THE MAIN CHANGE WITH THIS FCST PACKAGE IS TO EXPAND THE WIND
ADVISORY TO THE EAST THROUGH THE REMAINDER OF THE CWFA FOR TODAY.
OTHERWISE...THE FCST REMAINS MAINLY ON TRACK WITH A SLIGHTLY SLOWER
TREND TO THE RAIN MOVING IN FOR TODAY.
REGARDING THE EXPANSION OF THE WIND ADVISORY FIRST...WINDS REMAIN
RATHER BRISK AND THIS EARLY MORNING HOUR ACROSS THE CWFA. SOME GUSTS
OF AROUND 30 KNOTS ARE ALREADY OCCURRING THIS MORNING...AND THIS
WILL ONLY INCREASE DURING THE DAYLIGHT HOURS AS THE GRADIENT
TIGHTENS MORE AND AS DIURNAL MIXING WILL HELP TO BRING SOME OF THE
STRONGER WINDS DOWN FROM ALOFT. IT SEEMS THAT 40 KNOTS SHOULD BE
PRETTY EASY TO MIX DOWN...EVEN IN A WAA PATTERN.
AS FAR AS THE RAINFALL IS CONCERNED...THE TREND OVER THE PAST 24
HOURS IS THAT OF A SLOWER ONE WITH THE FEED OF DRY AIR COMING IN ON
THE BRISK ERLY WINDS AND HELPING TO DIMINISH MOST ALL PCPN TRYING TO
MOVE IN. THE UPPER RIDGE AXIS THAT IS ONLY SLOWLY CRAWLING EASTWARD
ACROSS THE CWFA IS FAR ENOUGH EAST AT THIS TIME THAT ENOUGH MOISTURE
TRANSPORT IS OCCURRING AND A COUPLE OF SPRINKLES/LIGHT SHOWERS ARE
OCCURRING ACROSS THE FAR SW CORNER OF THE CWFA. WE DO EXPECT THAT
PCPN WILL BE ON THE INCREASE TODAY FROM SW TO NE AS THE UPPER LOW
ROTATES A LITTLE CLOSER. THUNDER IS STILL POSSIBLE ACROSS THE FAR
SOUTH THIS AFTERNOON AS SLIGHTLY NEGATIVE ELEVATED LI/S MOVE UP INTO
THE AREA. SEVERE WX IS NOT EXPECTED AT THIS TIME WITH NO SFC
INSTABILITY EXPECTED THROUGH TONIGHT.
THE BEST THREAT OF RAIN SHOWERS AND STORMS LOOKS TO COME THIS
EVENING AND INTO THE OVERNIGHT HOURS. THE BEST MOISTURE AXIS PASSES
FROM SOUTH TO NORTH DURING THIS TIME FRAME...OUT AHEAD OF THE
OCCLUDED FRONT. WE CONTINUE TO EXPECT LITTLE THREAT OF SEVERE STORMS
TONIGHT ONCE AGAIN AS THE INSTABILITY WILL ONCE AGAIN BE ELEVATED.
THE RAIN CHANCES WILL THEN DIMINISH LATE TONIGHT AND EARLY TUE
MORNING AS THE MOISTURE TRANSPORT AND LLJ PEEL OFF TO THE EAST OF
THE STATE.
WE CONTINUE TO LOOK FOR A BRIEF WARM UP FOR THE DAY ON TUE WITH 70
DEGREE TEMPERATURES LOOKING MORE LIKELY. THE FRONT WILL BE NEAR THE
SRN STATE BORDER AT 12Z ON TUE. THE UPPER LOW COMING IN FROM THE
WEST WILL PUSH THE FRONT NORTH THROUGH THE AREA. EVEN THOUGH IT WILL
NOT BE THE TRUE WARM SECTOR...H850 TEMPS ARE STILL VERY MILD...AND
WILL WE TAP THAT WARMTH AS THE DRY SLOT MOVES IN AND WE GET SOME
SUN. H850 TEMPS AROUND +10 C WILL SUPPORT MANY LOCATIONS HITTING 70.
IT DOES LOOK LIKE LATE IN THE AFTERNOON WE WILL SEE CONVECTION TRY
TO FIRE OVERHEAD AS A WAVE ROTATES AROUND THE UPPER LOW AND MOVES
TOWARD THE AREA.
THERE IS SOME CONCERN WITH CONVECTION FIRING ON TUE AFTERNOON AS
STRONG JET STREAM WINDS WILL STILL BE OVERHEAD ACROSS SE LOWER.
THIS WILL PROVIDE FOR GOOD SHEAR IN THE DEEP LAYER. MUCH BETTER
INSTABILITY /LI/S OF -6 TO -8C/ WILL BE FOUND FURTHER SE ALSO.
WE STAY RELATIVELY WARM THROUGH MOST OF WED AS THE LOW LEVEL COLD
AIR DOES NOT COME IN UNTIL LATE WED AFTERNOON AND WED EVENING. THIS
IS THE CASE AS THE UPPER LOW HELPS ANOTHER WAVE TOWARD THE AREA AND
THE FLOW AHEAD OF IT WILL CONTINUE TO SUPPORT WARM TEMPS UNTIL THE
LOW MOVES THROUGH LATE WED. SHOWERS AND STORMS WILL REMAIN POSSIBLE
AHEAD OF THIS WAVE FOR TUE NIGHT AND WED. WE WILL LIKELY NOT REACH
70 AGAIN...BUT WE SHOULD BE WELL INTO THE 60S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 325 AM EDT MON APR 28 2014
LITTLE QUESTION OCCASIONAL SHOWERS AND COOLER THAN NORMAL
TEMPERATURES WILL PREVAIL THROUGH SATURDAY AS WE REMAIN ON THE
CYCLONIC SIDE OF THE UPPER JET WITH A FAIR AMOUNT OF DEEP MOISTURE.
SOME QUESTION ARISES WHAT HAPPENS FROM SUNDAY AND BEYOND SO I KEEP
THE LOW CHANCE POP FOR SUNDAY BUT IT MAY BE WE ACTUALLY GET TO SEE
THE SUN ONCE AGAIN BY SUNDAY AS THE UPPER JET MAY FINALLY LIFT NORTH
OF LOWER MICHIGAN MY THEN.
MODEL CONTINUE TO BE IN GOOD AGREEMENT WITH THE CLOSED UPPER LOW
REMAINING IN PLACE INTO AS LEAST SATURDAY. THE 500 MB HEIGHT
ANOMALIES ARE ON THE ORDER OF 2-3 STD BELOW NORMAL INTO SATURDAY
OVER THE LOWER GREAT LAKES. 850 MB TEMPERATURES ARE 1 TO 2 STD BELOW
NORMAL INTO SATURDAY.
THE MODELS CONTINUE TO FEATURE THAT ARCTIC JET STREAK FEEDING INTO
THE SYSTEM FRIDAY INTO SATURDAY. THAT WILL MAINTAIN THIS PATTERN
INTO SATURDAY FOR SURE. FROM SUNDAY ON THERE IS A QUESTION OF
WHETHER ANOTHER PACIFIC SYSTEM CAN BREAK THROUGH THE WESTERN RIDGE
TO PUSH THIS PATTERN OUT OF THE WAY OR IF WE WILL CONTINUE TO SEE
MORE IN A SERIES OF NORTHERN STREAM OF SYSTEMS. I KEEP LOW CHANCE
POPS FOR SUNDAY JUST IN CASE THE LATER OCCURS.
AS FOR THE SHOWERS WEDNESDAY NIGHT THROUGH SATURDAY AFTERNOON...
GIVEN THE DEEP CYCLONIC FLOW...DEEP MOISTURE AND SATURATED DGZ PLUS
SURFACE CONVERGENCE ALONG THE LAKE MICHIGAN SHORE AREAS INTO
SATURDAY I HAVE TO BELIEVE WE WILL CONTINUE TO SEE LIGHT SHOWER
THROUGH THIS ENTIRE PERIOD. I HAVE CONTINUED THE LIKELY POPS INTO
FRIDAY AND HIGH CHANCE INTO SATURDAY. TEMPERATURES WILL BE BETWEEN 5
AND 10 DEGREES BELOW NORMAL THROUGH THIS PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 741 AM EDT MON APR 28 2014
OUR MAJOR QUESTION IS WHEN WILL THE RAIN ARRIVE AND MORE THAN THAT
WHEN WILL THE MVFR/IFR CIGS/VSBY MOVE IN AS THE STORM TO OUR
SOUTHWEST SLOWLY MOVES TOWARD THE REGION. THE HUDSON BAY HIGH
CONTINUES TO FEED VERY DRY AIR FROM THE EAST AND IT WILL CONTINUE
TO ERROD THE RAIN AS MOVES INTO SOUTHWEST MICHIGAN. THIS IS NOT TO
SAY THERE WILL NOT BE SOME LIGHT RAIN SHOWERS BUT IT SEEMS THE
BULK OF THE SIGNIFICANT RAIN WILL LARGELY STAY NEAR AND SOUTH OF
INTERSTATE 94 TODAY (USING THE RAP13 MODEL AND HRRR ).
I DID BRING THE SHOWERS INTO THE AZO...BTL AND JXN BY LATE MORNING
BUT I DID NOT BRING THOSE SHOWERS INTO GRR...MKG AND LAN TILL LATE
AFTERNOON... EVEN THEN VSBY SHOULD BE VFR FOR THE MOST PART. I PUT
VCSH AT ALL THE TAF SITES DURING THE MID MORNING HOURS SINCE
SHOWERS WILL BE AROUND BUT VERY LIGHT (MOSTLY SPRINKLES).
THE MVFR CIGS/VSBY SHOULD REACH THE I-94 TAT SITES BY LATE
AFTERNOON THEN SPREAD INTO THE I-96 SITES AFTER 00Z. ANY
THUNDERSTORM ACTIVITY SHOULD HOLD OFF UNTIL TUESDAY.
&&
.MARINE...
ISSUED AT 1056 AM EDT MON APR 28 2014
GALE WARNING TO CONTINUE. SOME GUSTS OVER GALE FORCE ALREADY
OBSERVED. WINDS LIKELY TO INCREASE AS THE LOW LEVEL JET
STRENGTHENS AND MIXING HEIGHTS INCREASE.
&&
.HYDROLOGY...
ISSUED AT 241 PM EDT SUN APR 27 2014
I DOWNPLAYED THE QPF THROUGH TUE. THE DRY AIRMASS CURRENTLY IN
PLACE SHOULD ACT TO DELAY THE ARRIVAL OF THE SHOWERS. MODELS ARE
GENERALLY SHOWING A DIMINISHING TREND TO THE INITIAL BAND OF
SHOWERS DURING THE DAY ON MONDAY. STILL LOOKS LIKE ENOUGH RAIN TO
CAUSE RIVER RISES. ANOTHER BATCH OF RAIN TUE NIGHT INTO WED MAY BE
HEAVY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ037>040-043>046-
050>052-056>059-064>067-071>074.
LM...GALE WARNING UNTIL 8 AM EDT TUESDAY FOR LMZ844>849.
&&
$$
UPDATE...MJS
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...MJS
MARINE...MJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
741 AM EDT MON APR 28 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 325 AM EDT MON APR 28 2014
AN EXPANSIVE AND STRONG SYSTEM CENTERED ACROSS THE CENTRAL PLAINS
STATES WILL DRIVE RAINFALL INTO THE AREA AHEAD OF AN ASSOCIATED
FRONTAL SYSTEM TO OUR SOUTH. COOL AND WINDY CONDITIONS CAN BE
EXPECTED TODAY WITH AN INCREASING CHANCE OF RAIN. RAIN WILL CONTINUE
INTO EARLY TUESDAY BEFORE THE RAIN MOVES NORTH AND A SHORT PERIOD OF
WARMER AIR MOVES IN ACROSS THE AREA. ADDITIONAL SHOWERS AND STORMS
WILL BE POSSIBLE TUESDAY AND WEDNESDAY AS ADDITIONAL WAVES OF LOW
PRESSURE MOVE THROUGH THE AREA. COOLER CONDITIONS WILL THEN RETURN
FOR LATE THIS WEEK ALONG WITH A CONTINUED CHANCE OF RAIN SHOWERS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 325 AM EDT MON APR 28 2014
THE MAIN CHANGE WITH THIS FCST PACKAGE IS TO EXPAND THE WIND
ADVISORY TO THE EAST THROUGH THE REMAINDER OF THE CWFA FOR TODAY.
OTHERWISE...THE FCST REMAINS MAINLY ON TRACK WITH A SLIGHTLY SLOWER
TREND TO THE RAIN MOVING IN FOR TODAY.
REGARDING THE EXPANSION OF THE WIND ADVISORY FIRST...WINDS REMAIN
RATHER BRISK AND THIS EARLY MORNING HOUR ACROSS THE CWFA. SOME GUSTS
OF AROUND 30 KNOTS ARE ALREADY OCCURRING THIS MORNING...AND THIS
WILL ONLY INCREASE DURING THE DAYLIGHT HOURS AS THE GRADIENT
TIGHTENS MORE AND AS DIURNAL MIXING WILL HELP TO BRING SOME OF THE
STRONGER WINDS DOWN FROM ALOFT. IT SEEMS THAT 40 KNOTS SHOULD BE
PRETTY EASY TO MIX DOWN...EVEN IN A WAA PATTERN.
AS FAR AS THE RAINFALL IS CONCERNED...THE TREND OVER THE PAST 24
HOURS IS THAT OF A SLOWER ONE WITH THE FEED OF DRY AIR COMING IN ON
THE BRISK ERLY WINDS AND HELPING TO DIMINISH MOST ALL PCPN TRYING TO
MOVE IN. THE UPPER RIDGE AXIS THAT IS ONLY SLOWLY CRAWLING EASTWARD
ACROSS THE CWFA IS FAR ENOUGH EAST AT THIS TIME THAT ENOUGH MOISTURE
TRANSPORT IS OCCURRING AND A COUPLE OF SPRINKLES/LIGHT SHOWERS ARE
OCCURRING ACROSS THE FAR SW CORNER OF THE CWFA. WE DO EXPECT THAT
PCPN WILL BE ON THE INCREASE TODAY FROM SW TO NE AS THE UPPER LOW
ROTATES A LITTLE CLOSER. THUNDER IS STILL POSSIBLE ACROSS THE FAR
SOUTH THIS AFTERNOON AS SLIGHTLY NEGATIVE ELEVATED LI/S MOVE UP INTO
THE AREA. SEVERE WX IS NOT EXPECTED AT THIS TIME WITH NO SFC
INSTABILITY EXPECTED THROUGH TONIGHT.
THE BEST THREAT OF RAIN SHOWERS AND STORMS LOOKS TO COME THIS
EVENING AND INTO THE OVERNIGHT HOURS. THE BEST MOISTURE AXIS PASSES
FROM SOUTH TO NORTH DURING THIS TIME FRAME...OUT AHEAD OF THE
OCCLUDED FRONT. WE CONTINUE TO EXPECT LITTLE THREAT OF SEVERE STORMS
TONIGHT ONCE AGAIN AS THE INSTABILITY WILL ONCE AGAIN BE ELEVATED.
THE RAIN CHANCES WILL THEN DIMINISH LATE TONIGHT AND EARLY TUE
MORNING AS THE MOISTURE TRANSPORT AND LLJ PEEL OFF TO THE EAST OF
THE STATE.
WE CONTINUE TO LOOK FOR A BRIEF WARM UP FOR THE DAY ON TUE WITH 70
DEGREE TEMPERATURES LOOKING MORE LIKELY. THE FRONT WILL BE NEAR THE
SRN STATE BORDER AT 12Z ON TUE. THE UPPER LOW COMING IN FROM THE
WEST WILL PUSH THE FRONT NORTH THROUGH THE AREA. EVEN THOUGH IT WILL
NOT BE THE TRUE WARM SECTOR...H850 TEMPS ARE STILL VERY MILD...AND
WILL WE TAP THAT WARMTH AS THE DRY SLOT MOVES IN AND WE GET SOME
SUN. H850 TEMPS AROUND +10 C WILL SUPPORT MANY LOCATIONS HITTING 70.
IT DOES LOOK LIKE LATE IN THE AFTERNOON WE WILL SEE CONVECTION TRY
TO FIRE OVERHEAD AS A WAVE ROTATES AROUND THE UPPER LOW AND MOVES
TOWARD THE AREA.
THERE IS SOME CONCERN WITH CONVECTION FIRING ON TUE AFTERNOON AS
STRONG JET STREAM WINDS WILL STILL BE OVERHEAD ACROSS SE LOWER.
THIS WILL PROVIDE FOR GOOD SHEAR IN THE DEEP LAYER. MUCH BETTER
INSTABILITY /LI/S OF -6 TO -8C/ WILL BE FOUND FURTHER SE ALSO.
WE STAY RELATIVELY WARM THROUGH MOST OF WED AS THE LOW LEVEL COLD
AIR DOES NOT COME IN UNTIL LATE WED AFTERNOON AND WED EVENING. THIS
IS THE CASE AS THE UPPER LOW HELPS ANOTHER WAVE TOWARD THE AREA AND
THE FLOW AHEAD OF IT WILL CONTINUE TO SUPPORT WARM TEMPS UNTIL THE
LOW MOVES THROUGH LATE WED. SHOWERS AND STORMS WILL REMAIN POSSIBLE
AHEAD OF THIS WAVE FOR TUE NIGHT AND WED. WE WILL LIKELY NOT REACH
70 AGAIN...BUT WE SHOULD BE WELL INTO THE 60S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 325 AM EDT MON APR 28 2014
LITTLE QUESTION OCCASIONAL SHOWERS AND COOLER THAN NORMAL
TEMPERATURES WILL PREVAIL THROUGH SATURDAY AS WE REMAIN ON THE
CYCLONIC SIDE OF THE UPPER JET WITH A FAIR AMOUNT OF DEEP MOISTURE.
SOME QUESTION ARISES WHAT HAPPENS FROM SUNDAY AND BEYOND SO I KEEP
THE LOW CHANCE POP FOR SUNDAY BUT IT MAY BE WE ACTUALLY GET TO SEE
THE SUN ONCE AGAIN BY SUNDAY AS THE UPPER JET MAY FINALLY LIFT NORTH
OF LOWER MICHIGAN MY THEN.
MODEL CONTINUE TO BE IN GOOD AGREEMENT WITH THE CLOSED UPPER LOW
REMAINING IN PLACE INTO AS LEAST SATURDAY. THE 500 MB HEIGHT
ANOMALIES ARE ON THE ORDER OF 2-3 STD BELOW NORMAL INTO SATURDAY
OVER THE LOWER GREAT LAKES. 850 MB TEMPERATURES ARE 1 TO 2 STD BELOW
NORMAL INTO SATURDAY.
THE MODELS CONTINUE TO FEATURE THAT ARCTIC JET STREAK FEEDING INTO
THE SYSTEM FRIDAY INTO SATURDAY. THAT WILL MAINTAIN THIS PATTERN
INTO SATURDAY FOR SURE. FROM SUNDAY ON THERE IS A QUESTION OF
WHETHER ANOTHER PACIFIC SYSTEM CAN BREAK THROUGH THE WESTERN RIDGE
TO PUSH THIS PATTERN OUT OF THE WAY OR IF WE WILL CONTINUE TO SEE
MORE IN A SERIES OF NORTHERN STREAM OF SYSTEMS. I KEEP LOW CHANCE
POPS FOR SUNDAY JUST IN CASE THE LATER OCCURS.
AS FOR THE SHOWERS WEDNESDAY NIGHT THROUGH SATURDAY AFTERNOON...
GIVEN THE DEEP CYCLONIC FLOW...DEEP MOISTURE AND SATURATED DGZ PLUS
SURFACE CONVERGENCE ALONG THE LAKE MICHIGAN SHORE AREAS INTO
SATURDAY I HAVE TO BELIEVE WE WILL CONTINUE TO SEE LIGHT SHOWER
THROUGH THIS ENTIRE PERIOD. I HAVE CONTINUED THE LIKELY POPS INTO
FRIDAY AND HIGH CHANCE INTO SATURDAY. TEMPERATURES WILL BE BETWEEN 5
AND 10 DEGREES BELOW NORMAL THROUGH THIS PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 741 AM EDT MON APR 28 2014
OUR MAJOR QUESTION IS WHEN WILL THE RAIN ARRIVE AND MORE THAN THAT
WHEN WILL THE MVFR/IFR CIGS/VSBY MOVE IN AS THE STORM TO OUR
SOUTHWEST SLOWLY MOVES TOWARD THE REGION. THE HUDSON BAY HIGH
CONTINUES TO FEED VERY DRY AIR FROM THE EAST AND IT WILL CONTINUE
TO ERROD THE RAIN AS MOVES INTO SOUTHWEST MICHIGAN. THIS IS NOT TO
SAY THERE WILL NOT BE SOME LIGHT RAIN SHOWERS BUT IT SEEMS THE
BULK OF THE SIGNIFICANT RAIN WILL LARGELY STAY NEAR AND SOUTH OF
INTERSTATE 94 TODAY (USING THE RAP13 MODEL AND HRRR ).
I DID BRING THE SHOWERS INTO THE AZO...BTL AND JXN BY LATE MORNING
BUT I DID NOT BRING THOSE SHOWERS INTO GRR...MKG AND LAN TILL LATE
AFTERNOON... EVEN THEN VSBY SHOULD BE VFR FOR THE MOST PART. I PUT
VCSH AT ALL THE TAF SITES DURING THE MID MORNING HOURS SINCE
SHOWERS WILL BE AROUND BUT VERY LIGHT (MOSTLY SPRINKLES).
THE MVFR CIGS/VSBY SHOULD REACH THE I-94 TAT SITES BY LATE
AFTERNOON THEN SPREAD INTO THE I-96 SITES AFTER 00Z. ANY
THUNDERSTORM ACTIVITY SHOULD HOLD OFF UNTIL TUESDAY.
&&
.MARINE...
ISSUED AT 325 AM EDT MON APR 28 2014
WE HAVE CONTINUED THE GALE WARNING FOR THE ENTIRE NEARSHORE AND
ADDED 12 HRS TO THE DURATION FOR THIS FCST PACKAGE. COASTAL
OBSERVATIONS INDICATE THAT WINDS ARE ON THE VERGE OF GALE CRITERIA
ALREADY EARLY THIS MORNING. WE EXPECTED TO WIND GUSTS TO CONTINUE
WITH THE FLOW BEING AN OFFSHORE ONE AND DIURNAL MIXING INLAND
HELPING TO INCREASE THE GUSTS AFTER SUNRISE TODAY. STRONGER WINDS
JUST OFF THE SFC WILL REMAIN FOR MOST OF THE NIGHT BEFORE
DIMINISHING ON TUE.
&&
.HYDROLOGY...
ISSUED AT 241 PM EDT SUN APR 27 2014
I DOWNPLAYED THE QPF THROUGH TUE. THE DRY AIRMASS CURRENTLY IN
PLACE SHOULD ACT TO DELAY THE ARRIVAL OF THE SHOWERS. MODELS ARE
GENERALLY SHOWING A DIMINISHING TREND TO THE INITIAL BAND OF
SHOWERS DURING THE DAY ON MONDAY. STILL LOOKS LIKE ENOUGH RAIN TO
CAUSE RIVER RISES. ANOTHER BATCH OF RAIN TUE NIGHT INTO WED MAY BE
HEAVY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ037>040-043>046-
050>052-056>059-064>067-071>074.
LM...GALE WARNING UNTIL 8 AM EDT TUESDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...MJS
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
717 AM EDT MON APR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 511 AM EDT MON APR 28 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER
LEVEL TROUGH FROM THE NW CONUS THROUGH THE CENTRAL PLAINS WITH A
CLOSED LOW OVER NEBRASKA. DOWNSTREAM A RIDGE EXTENDED FROM THE SE
CONUS THROUGH WRN LAKES INTO MANITOBA. AT THE SFC...A BRISK ERLY
FLOW PREVAILED THROUGH THE NRN LAKES BETWEEN HIGH PRES OVER HUDSON
BAY AND A DEEP LOW OVER ERN NEBRASKA. ISENTROPIC ASCENT AS NOTED ON
THE 295K SFC HAS PRODUCED SEVERAL BANDS OF LIGHT PCPN OVER UPPER MI
THIS MORNING BUT THIS PCPN HAS FALLEN MAINLY AS JUST
SPRINKLES/FLURRIES AS IT ENCOUNTERS VERY DRY AIR BELOW 750 MB.
TODAY...MODELS CONSISTENT SHOWING SYSTEM OVER ERN NEBRASKA STALLING
AND BEGINNING TO OCCLUDE TODAY. MODELS SHOW WEAKENING ISENTROPIC
ASCENT OVER UPR MI AND A LACK OF 850-700 MB MOISTURE ADVECTION INTO
THE REGION. THIS FACT ALONG WITH MID-LVL RDG GENERALLY STAYING IN
PLACE SHOULD KEEP MUCH OF THE CWA DRY TODAY. INCREASING 850-700 MB
MOISTURE ADV AND ISENTROPIC ASCENT COULD BRING IN A BETTER CHC OF
RAIN TOWARD 00Z THIS EVENING OVER MAINLY FAR SCNTRL CWA.
TONIGHT...MODELS SHOW MORE SUBSTANTIAL SHORTWAVE LOBE ROTATING
NORTHWARD AHEAD OF PLAINS CLOSED LOW WHICH IN TURN WILL PROPEL 850
MB WARM FRONT NORTHWARD INTO THE SE CWA LATE TONIGHT. INCREASING
ISENTROPIC ASCENT AND 850-700 MB MOISTURE ADVECTION SPREADING IN
FROM THE SSE AHEAD OF THE WARM FRONT WILL BRING INCREASING RAIN CHCS
INTO SCNTRL CWA THIS EVENING SPREADING INTO THE REST OF THE SE HALF
OF THE CWA OVERNIGHT TONIGHT. THICKNESS VALUES AND SOUNDINGS SUGGEST
SNOW MAY MIX WITH RAIN OVER NCNTRL AND NW CWA LATE TONIGHT BUT PCPN
SHOULD BE LIGHT THAT ANY SNOW AMTS WILL HAVE LITTLE IMPACT ON TRAVEL.
MODEL QPF INDICATES SCNTRL CWA COULD SEE FROM .25 TO PERHAPS .75 OF
AN INCH OF RAINFALL TONIGHT WHICH WILL ADD TO RUNOFF FOR AREA STREAMS
AND RIVERS INTO MIDWEEK.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM EDT MON APR 28 2014
FOCUSED ATTENTION ON TUE-WED NIGHT TIME FRAME AS MOST SIGNIFICANT
PRECIP IS EXPECTED DURING THAT TIME.
THE SETUP FOR MID WEEK IS QUITE INTERESTING ACROSS THE CONUS AS A
DEEP CLOSED UPPER LOW IS OVER THE CENTRAL CONUS...BORDERED ON THE
W...N AND E BY AMPLIFIED UPPER RIDGING. ALSO...AT THE START OF THE
LONG TERM /12 TUE/...THE UPPER LOW WILL BE ABSORBING A WEAK UPPER
LOW THAT ORIGINATED OVER QUEBEC. THE SYSTEM WILL BE QUITE WRAPPED
UP...WITH GREAT MOISTURE TRANSPORT FROM BOTH THE GULF OF MEXICO AND
THE ATLANTIC THAT FOCUSES OVER THE LOWER GREAT LAKES BEFORE
WRAPPING W ACROSS THE CWA AND EVENTUALLY TO THE W OF THE LOW /WHICH
IS OVER IA AT 12Z TUE/. PRECIP TUE WILL BE PRIMARILY FORCED BY
50-60KT 900-700MB WINDS...RESULTING IN GOOD MOISTURE TRANSPORT IN
THIS LAYER AS WELL AS STRONG ISENTROPIC ASCENT AS ISENTROPIC
SURFACES INCREASE IN HEIGHT BY AROUND 1KM FROM UPSTREAM TO
DOWNSTREAM ACROSS THE CWA. PWAT VALUES WILL BE 0.75-1.00 INCHES...OR
GENERALLY 150-200 PERCENT OF NORMAL. ANOTHER SIGNIFICANT FORCING
MECHANISM IS A SHORTWAVE THAT MODELS SHOW MOVING ACROSS THE CWA
TUE...WHICH LEADS TO STEEP 700-500MB LAPSE RATES OF JUST OVER 7C/KM.
ADDITIONALLY...THE LEFT EXIT REGION OF AN UPPER JET WILL BE ACROSS
THE CWA. ALL THESE INGREDIENTS COME TOGETHER TO PRODUCE SIGNIFICANT
QPF AMOUNTS FROM THE MODELS LATE MON NIGHT INTO TUE. THE MOST PRECIP
SHOULD FALL NEAR LAKE MICHIGAN WHERE THE BEST FORCING AND MOISTURE
IS EXPECTED. EVEN THE LOWER RES MODELS /THAT TYPICALLY DO NOT
PERFORM AS WELL IN THIS TYPE OF SITUATION/ HAVE UP TO AN INCH OF QPF
NEAR LAKE MICHIGAN...WHILE THE NAM HAS THE MOST QPF AT 2.25 INCHES.
WILL GO WITH A CONSENSUS APPROACH OF GFS/ECMWF AND REGIONAL GEM
/WHICH HAS UP TO 1.85 INCHES/...WHICH INCORPORATES MON NIGHT /SHORT
TERM/. THE ECMWF/GFS HAVE THE BEST PRECIP LATE MON NIGHT INTO TUE
MORNING...WHILE THE NAM HAS THE BEST PRECIP ON TUE. THE REGIONAL GEM
IS BETWEEN THE NAM AND GFS/ECMWF. A COMPLICATING FACTOR TO THIS TIME
FRAME IS THAT MODEL TEMP PROFILES FAVOR PRECIP TO BE SNOW OVER WRN
UPPER MI AND RAIN NEAR LAKE MICHIGAN AND E...WITH A MIX BETWEEN. DUE
TO SFC TEMPS BEING NEAR OR ABOVE FREEZING AND STRONG SOLAR EFFECTS
THIS TIME OF YEAR...ACCUMULATIONS ON PAVED SURFACES SHOULD BE
MINIMAL...BUT GRASSY SURFACES OVER THE HIGHER TERRAIN OF WRN UPPER
MI COULD SEE 2-3 INCHES OF SNOW. GIVEN VERY MINIMAL EXPECTED IMPACTS
TO TRAVEL...WILL CONTINUE TO NOT MENTION SNOW IN THE HWO. DEPENDING
ON EXACT PRECIP AMOUNTS...COULD SEE SOME SIGNIFICANT RISES ON AREA
RIVERS.
ANOTHER SHOT AT GOOD ISENTROPIC ASCENT AND A STRONG SHORTWAVE ARE
SHOWN BY MODELS FOR WED AS THE UPPER LOW CONTINUES TO WEAKEN AND
BEGINS MOVING NE TOWARD THE CWA. SIGNALS FOR PRECIP AMOUNTS AND
TRENDS ARE A LOT MORE MUDDLED ON WED INTO WED NIGHT AS THE CWA WILL
BE MORE REMOVED FROM THE BEST MOISTURE TRANSPORT...WHICH WILL BE
MORE FOCUSED E AND N OF THE CWA. THINK THAT MUCH OF THE CWA WILL SEE
PRECIP...WITH POTENTIAL FOR UP TO AN INCH OF ADDITIONAL PRECIP
DURING THIS TIME PERIOD. USED A BROAD CONSENSUS OF GUIDANCE DURING
THIS PERIOD.
THE UPPER LOW WILL CONTINUE TO WEAKEN AND MOVE SLOWLY NE INTO LATE
WEEK BEFORE ADDITIONAL UPPER LEVEL ENERGY MOVES INTO THE REGION LATE
THIS WEEK INTO THE WEEKEND...LEADING TO CONTINUED WET WEATHER...BUT
AMOUNTS WILL BE LOWER THROUGH THE REST OF THE WEEK. USED A CONSENSUS
OF GUIDANCE FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 711 AM EDT MON APR 28 2014
VFR CONDITIONS WILL PREVAIL UNTIL LATE TONIGHT. THERE COULD BE SOME
INTERMITTENT LIGHT RAIN/SPRINKLES AT KIWD THIS MORNING BUT OTHERWISE
MID CLOUDS AND VFR CONDITIONS WILL PREVAIL. INCREASING MOISTURE AHEAD
OF A WARM FRONT WILL BRING INCREASING CHCS OF RAIN LATE TONIGHT AT
ALL TAF SITES AS CIGS LOWER TO MVFR AND POSSIBLY IFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 511 AM EDT MON APR 28 2014
EAST TO NORTHEAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE
DEEPENS OVER THE PLAINS. EXPECT ENE GALES TO 35KTS OVER MUCH OF WRN
LAKE SUPERIOR INTO TUE MORNING. THERE IS ALSO A CHANCE FOR ENE GALES
TO 35 KNOTS OVER CENTRAL LAKE SUPERIOR FOR LATE TONIGHT INTO TUE SO
HAVE ISSUED A GALE WATCH FOR LSZ264-266 WINDS SHOULD GRADUALLY
DIMINISH LATE TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH
TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER
WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE EVENING. WINDS ARE
EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED INTO FRI AS THE
LOW FILLS AND REMAINS NEAR UPPER MICHIGAN.
&&
.HYDROLOGY...
ISSUED AT 358 AM EDT MON APR 28 2014
RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH
THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA
STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR
ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR
CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER
NEAR NAHMA JUNCTION. AT LEAST THROUGH TONIGHT THESE RIVERS ARE NOT
EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER RIVERS WILL
START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE SYSTEM AND
WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL LIQUID
EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES BY
THURSDAY. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK. WHILE
WIDESPREAD AND AREAL FLOODING IS NOT EXPECTED...RFC ENSEMBLE
FORECASTS DO SHOW SIGNIFICANT RISES ON A FEW OF THE RIVERS IF HIGHER
QPF FROM THE MODELS VERIFIES. THOSE LIVING AROUND
RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS WEEK.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR
LSZ264>266.
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ TUESDAY FOR LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...VOSS
MARINE...VOSS
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
513 AM EDT MON APR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 511 AM EDT MON APR 28 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER
LEVEL TROUGH FROM THE NW CONUS THROUGH THE CENTRAL PLAINS WITH A
CLOSED LOW OVER NEBRASKA. DOWNSTREAM A RIDGE EXTENDED FROM THE SE
CONUS THROUGH WRN LAKES INTO MANITOBA. AT THE SFC...A BRISK ERLY
FLOW PREVAILED THROUGH THE NRN LAKES BETWEEN HIGH PRES OVER HUDSON
BAY AND A DEEP LOW OVER ERN NEBRASKA. ISENTROPIC ASCENT AS NOTED ON
THE 295K SFC HAS PRODUCED SEVERAL BANDS OF LIGHT PCPN OVER UPPER MI
THIS MORNING BUT THIS PCPN HAS FALLEN MAINLY AS JUST
SPRINKLES/FLURRIES AS IT ENCOUNTERS VERY DRY AIR BELOW 750 MB.
TODAY...MODELS CONSISTENT SHOWING SYSTEM OVER ERN NEBRASKA STALLING
AND BEGINNING TO OCCLUDE TODAY. MODELS SHOW WEAKENING ISENTROPIC
ASCENT OVER UPR MI AND A LACK OF 850-700 MB MOISTURE ADVECTION INTO
THE REGION. THIS FACT ALONG WITH MID-LVL RDG GENERALLY STAYING IN
PLACE SHOULD KEEP MUCH OF THE CWA DRY TODAY. INCREASING 850-700 MB
MOISTURE ADV AND ISENTROPIC ASCENT COULD BRING IN A BETTER CHC OF
RAIN TOWARD 00Z THIS EVENING OVER MAINLY FAR SCNTRL CWA.
TONIGHT...MODELS SHOW MORE SUBSTANTIAL SHORTWAVE LOBE ROTATING
NORTHWARD AHEAD OF PLAINS CLOSED LOW WHICH IN TURN WILL PROPEL 850
MB WARM FRONT NORTHWARD INTO THE SE CWA LATE TONIGHT. INCREASING
ISENTROPIC ASCENT AND 850-700 MB MOISTURE ADVECTION SPREADING IN
FROM THE SSE AHEAD OF THE WARM FRONT WILL BRING INCREASING RAIN CHCS
INTO SCNTRL CWA THIS EVENING SPREADING INTO THE REST OF THE SE HALF
OF THE CWA OVERNIGHT TONIGHT. THICKNESS VALUES AND SOUNDINGS SUGGEST
SNOW MAY MIX WITH RAIN OVER NCNTRL AND NW CWA LATE TONIGHT BUT PCPN
SHOULD BE LIGHT THAT ANY SNOW AMTS WILL HAVE LITTLE IMPACT ON TRAVEL.
MODEL QPF INDICATES SCNTRL CWA COULD SEE FROM .25 TO PERHAPS .75 OF
AN INCH OF RAINFALL TONIGHT WHICH WILL ADD TO RUNOFF FOR AREA STREAMS
AND RIVERS INTO MIDWEEK.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM EDT MON APR 28 2014
FOCUSED ATTENTION ON TUE-WED NIGHT TIME FRAME AS MOST SIGNIFICANT
PRECIP IS EXPECTED DURING THAT TIME.
THE SETUP FOR MID WEEK IS QUITE INTERESTING ACROSS THE CONUS AS A
DEEP CLOSED UPPER LOW IS OVER THE CENTRAL CONUS...BORDERED ON THE
W...N AND E BY AMPLIFIED UPPER RIDGING. ALSO...AT THE START OF THE
LONG TERM /12 TUE/...THE UPPER LOW WILL BE ABSORBING A WEAK UPPER
LOW THAT ORIGINATED OVER QUEBEC. THE SYSTEM WILL BE QUITE WRAPPED
UP...WITH GREAT MOISTURE TRANSPORT FROM BOTH THE GULF OF MEXICO AND
THE ATLANTIC THAT FOCUSES OVER THE LOWER GREAT LAKES BEFORE
WRAPPING W ACROSS THE CWA AND EVENTUALLY TO THE W OF THE LOW /WHICH
IS OVER IA AT 12Z TUE/. PRECIP TUE WILL BE PRIMARILY FORCED BY
50-60KT 900-700MB WINDS...RESULTING IN GOOD MOISTURE TRANSPORT IN
THIS LAYER AS WELL AS STRONG ISENTROPIC ASCENT AS ISENTROPIC
SURFACES INCREASE IN HEIGHT BY AROUND 1KM FROM UPSTREAM TO
DOWNSTREAM ACROSS THE CWA. PWAT VALUES WILL BE 0.75-1.00 INCHES...OR
GENERALLY 150-200 PERCENT OF NORMAL. ANOTHER SIGNIFICANT FORCING
MECHANISM IS A SHORTWAVE THAT MODELS SHOW MOVING ACROSS THE CWA
TUE...WHICH LEADS TO STEEP 700-500MB LAPSE RATES OF JUST OVER 7C/KM.
ADDITIONALLY...THE LEFT EXIT REGION OF AN UPPER JET WILL BE ACROSS
THE CWA. ALL THESE INGREDIENTS COME TOGETHER TO PRODUCE SIGNIFICANT
QPF AMOUNTS FROM THE MODELS LATE MON NIGHT INTO TUE. THE MOST PRECIP
SHOULD FALL NEAR LAKE MICHIGAN WHERE THE BEST FORCING AND MOISTURE
IS EXPECTED. EVEN THE LOWER RES MODELS /THAT TYPICALLY DO NOT
PERFORM AS WELL IN THIS TYPE OF SITUATION/ HAVE UP TO AN INCH OF QPF
NEAR LAKE MICHIGAN...WHILE THE NAM HAS THE MOST QPF AT 2.25 INCHES.
WILL GO WITH A CONSENSUS APPROACH OF GFS/ECMWF AND REGIONAL GEM
/WHICH HAS UP TO 1.85 INCHES/...WHICH INCORPORATES MON NIGHT /SHORT
TERM/. THE ECMWF/GFS HAVE THE BEST PRECIP LATE MON NIGHT INTO TUE
MORNING...WHILE THE NAM HAS THE BEST PRECIP ON TUE. THE REGIONAL GEM
IS BETWEEN THE NAM AND GFS/ECMWF. A COMPLICATING FACTOR TO THIS TIME
FRAME IS THAT MODEL TEMP PROFILES FAVOR PRECIP TO BE SNOW OVER WRN
UPPER MI AND RAIN NEAR LAKE MICHIGAN AND E...WITH A MIX BETWEEN. DUE
TO SFC TEMPS BEING NEAR OR ABOVE FREEZING AND STRONG SOLAR EFFECTS
THIS TIME OF YEAR...ACCUMULATIONS ON PAVED SURFACES SHOULD BE
MINIMAL...BUT GRASSY SURFACES OVER THE HIGHER TERRAIN OF WRN UPPER
MI COULD SEE 2-3 INCHES OF SNOW. GIVEN VERY MINIMAL EXPECTED IMPACTS
TO TRAVEL...WILL CONTINUE TO NOT MENTION SNOW IN THE HWO. DEPENDING
ON EXACT PRECIP AMOUNTS...COULD SEE SOME SIGNIFICANT RISES ON AREA
RIVERS.
ANOTHER SHOT AT GOOD ISENTROPIC ASCENT AND A STRONG SHORTWAVE ARE
SHOWN BY MODELS FOR WED AS THE UPPER LOW CONTINUES TO WEAKEN AND
BEGINS MOVING NE TOWARD THE CWA. SIGNALS FOR PRECIP AMOUNTS AND
TRENDS ARE A LOT MORE MUDDLED ON WED INTO WED NIGHT AS THE CWA WILL
BE MORE REMOVED FROM THE BEST MOISTURE TRANSPORT...WHICH WILL BE
MORE FOCUSED E AND N OF THE CWA. THINK THAT MUCH OF THE CWA WILL SEE
PRECIP...WITH POTENTIAL FOR UP TO AN INCH OF ADDITIONAL PRECIP
DURING THIS TIME PERIOD. USED A BROAD CONSENSUS OF GUIDANCE DURING
THIS PERIOD.
THE UPPER LOW WILL CONTINUE TO WEAKEN AND MOVE SLOWLY NE INTO LATE
WEEK BEFORE ADDITIONAL UPPER LEVEL ENERGY MOVES INTO THE REGION LATE
THIS WEEK INTO THE WEEKEND...LEADING TO CONTINUED WET WEATHER...BUT
AMOUNTS WILL BE LOWER THROUGH THE REST OF THE WEEK. USED A CONSENSUS
OF GUIDANCE FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 129 AM EDT MON APR 28 2014
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD UNDER MID CLOUDS.
E-NE WINDS COULD GUST NEAR 25 KT AT ALL TAF SITES AS PRES GRADIENT
TIGHTENS AHEAD OF LOW PRES OVER THE CENTRAL PLAINS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 511 AM EDT MON APR 28 2014
EAST TO NORTHEAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE
DEEPENS OVER THE PLAINS. EXPECT ENE GALES TO 35KTS OVER MUCH OF WRN
LAKE SUPERIOR INTO TUE MORNING. THERE IS ALSO A CHANCE FOR ENE GALES
TO 35 KNOTS OVER CENTRAL LAKE SUPERIOR FOR LATE TONIGHT INTO TUE SO
HAVE ISSUED A GALE WATCH FOR LSZ264-266 WINDS SHOULD GRADUALLY
DIMINISH LATE TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH
TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER
WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE EVENING. WINDS ARE
EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED INTO FRI AS THE
LOW FILLS AND REMAINS NEAR UPPER MICHIGAN.
&&
.HYDROLOGY...
ISSUED AT 358 AM EDT MON APR 28 2014
RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH
THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA
STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR
ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR
CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER
NEAR NAHMA JUNCTION. AT LEAST THROUGH TONIGHT THESE RIVERS ARE NOT
EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER RIVERS WILL
START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE SYSTEM AND
WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL LIQUID
EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES BY
THURSDAY. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK. WHILE
WIDESPREAD AND AREAL FLOODING IS NOT EXPECTED...RFC ENSEMBLE
FORECASTS DO SHOW SIGNIFICANT RISES ON A FEW OF THE RIVERS IF HIGHER
QPF FROM THE MODELS VERIFIES. THOSE LIVING AROUND
RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS WEEK.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR
LSZ264>266.
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ TUESDAY FOR LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...07/JV
MARINE...VOSS
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
401 AM EDT MON APR 28 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 432 PM EDT SUN APR 27 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER
LEVEL TROUGH THROUGH THE NW CONUS WITH A LOW OVER WRN KS AND A
DOWNSTREAM RIDGE FROM THE SE CONUS THROUGH WRN LAKES INTO MANITOBA.
AT THE SFC...A BRISK ERLY FLOW PREVAILED THROUGH THE NRN LAKES
BETWEEN HIGH PRES OVER HUDSON BAY AND A DEEP LOW OVER NW KS. AN
INITIAL BAND OF LIGHT PCPN WAS PRODUCING MAINLY JUST SPRINKLES INTO
THE FAR WRN CWA NEAR IWD AS IT ENCOUNTERS THE VERY DRY LAYER BELOW
750 MB. HOWEVER...A MORE SUBSTANTIAL AREA OF RAIN OVER WRN INTO N
CNTRL WI...SUPPORTED BY 300K ISENTROPIC LIFT WAS LIFTING TOWARD
UPPER MI.
TONIGHT...RADAR TRENDS AND SHORT TERM MODELS SUGGEST THAT SOME LIGHT
SHOWERS WILL MOVE INTO THE WEST LATE THIS AFTERNOON AND EVENING.
HOWEVER...THERE IS A LOWER CHANCE THAT THERE WILL BE MEASURABLE PCPN
GIVEN THE AMOUNT OF DRY AIR TO OVERCOME WITH THE ERLY LOW LEVEL
INFLOW. FARTHER TO THE EAST...OVER S CNTRL UPPER MI...THE DRY
AIR...PER 12Z APX SOUNDING...SHOULD BE MORE EFFECTIVE AT SLOWING THE
ADVANCE AND REDUCING PCPN CHANCES. WITH EVAPORATIVE COOLING AT THE
LEADING EDGE OF THE PCPN...SOME SNOW OR SLEET MAY ALSO MIX IN WITH THE
RAIN LATE THIS EVENING AND OVERNIGHT...PER NAM LOW LEVEL THICKNESS
AND WET-BULB ZERO HEIGHTS.
MON...THE MODELS WERE IN SLIGHTLY BETTER AGREEMENT IN HANDLING THE
ADVANCE OF PCPN INTO UPPER MICHIGAN. THE NAM/GFS/ECMWF WERE NOW ON
THE SLOWER SIDE COMPARED TO GEM. AS THE MID/UPPER LEVEL LOW SLOWLY
WOBBLES TO THE NORTHEAST AND AN ELONGATED TROUGH/FRONT EXTENDS FROM
SRN IA INTO NRN INDIANA. ANOTHER BAND OF RAIN WILL MOVE TOWARD UPPER
MI WITH INCREASING 300K-305K ISENTROPIC ASCENT NORTH OF THE 850 MB
WARM FRONT THROUGH CNTRL WI. THERE IS STILL LIKELY TO BE SHARP
CUTOFF TO THE NRN EDGE OF THE PCPN BAND THROUGH CNTRL UPPER MI. THE
HIGHEST CHANCES WILL REMAIN ALONG THE WI BORDER WITH ONLY A SLIGHT
CHANCE OVER THE NORTH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM EDT MON APR 28 2014
FOCUSED ATTENTION ON TUE-WED NIGHT TIME FRAME AS MOST SIGNIFICANT
PRECIP IS EXPECTED DURING THAT TIME.
THE SETUP FOR MID WEEK IS QUITE INTERESTING ACROSS THE CONUS AS A
DEEP CLOSED UPPER LOW IS OVER THE CENTRAL CONUS...BORDERED ON THE
W...N AND E BY AMPLIFIED UPPER RIDGING. ALSO...AT THE START OF THE
LONG TERM /12 TUE/...THE UPPER LOW WILL BE ABSORBING A WEAK UPPER
LOW THAT ORIGINATED OVER QUEBEC. THE SYSTEM WILL BE QUITE WRAPPED
UP...WITH GREAT MOISTURE TRANSPORT FROM BOTH THE GULF OF MEXICO AND
THE ATLANTIC THAT FOCUSES OVER THE LOWER GREAT LAKES BEFORE
WRAPPING W ACROSS THE CWA AND EVENTUALLY TO THE W OF THE LOW /WHICH
IS OVER IA AT 12Z TUE/. PRECIP TUE WILL BE PRIMARILY FORCED BY
50-60KT 900-700MB WINDS...RESULTING IN GOOD MOISTURE TRANSPORT IN
THIS LAYER AS WELL AS STRONG ISENTROPIC ASCENT AS ISENTROPIC
SURFACES INCREASE IN HEIGHT BY AROUND 1KM FROM UPSTREAM TO
DOWNSTREAM ACROSS THE CWA. PWAT VALUES WILL BE 0.75-1.00 INCHES...OR
GENERALLY 150-200 PERCENT OF NORMAL. ANOTHER SIGNIFICANT FORCING
MECHANISM IS A SHORTWAVE THAT MODELS SHOW MOVING ACROSS THE CWA
TUE...WHICH LEADS TO STEEP 700-500MB LAPSE RATES OF JUST OVER 7C/KM.
ADDITIONALLY...THE LEFT EXIT REGION OF AN UPPER JET WILL BE ACROSS
THE CWA. ALL THESE INGREDIENTS COME TOGETHER TO PRODUCE SIGNIFICANT
QPF AMOUNTS FROM THE MODELS LATE MON NIGHT INTO TUE. THE MOST PRECIP
SHOULD FALL NEAR LAKE MICHIGAN WHERE THE BEST FORCING AND MOISTURE
IS EXPECTED. EVEN THE LOWER RES MODELS /THAT TYPICALLY DO NOT
PERFORM AS WELL IN THIS TYPE OF SITUATION/ HAVE UP TO AN INCH OF QPF
NEAR LAKE MICHIGAN...WHILE THE NAM HAS THE MOST QPF AT 2.25 INCHES.
WILL GO WITH A CONSENSUS APPROACH OF GFS/ECMWF AND REGIONAL GEM
/WHICH HAS UP TO 1.85 INCHES/...WHICH INCORPORATES MON NIGHT /SHORT
TERM/. THE ECMWF/GFS HAVE THE BEST PRECIP LATE MON NIGHT INTO TUE
MORNING...WHILE THE NAM HAS THE BEST PRECIP ON TUE. THE REGIONAL GEM
IS BETWEEN THE NAM AND GFS/ECMWF. A COMPLICATING FACTOR TO THIS TIME
FRAME IS THAT MODEL TEMP PROFILES FAVOR PRECIP TO BE SNOW OVER WRN
UPPER MI AND RAIN NEAR LAKE MICHIGAN AND E...WITH A MIX BETWEEN. DUE
TO SFC TEMPS BEING NEAR OR ABOVE FREEZING AND STRONG SOLAR EFFECTS
THIS TIME OF YEAR...ACCUMULATIONS ON PAVED SURFACES SHOULD BE
MINIMAL...BUT GRASSY SURFACES OVER THE HIGHER TERRAIN OF WRN UPPER
MI COULD SEE 2-3 INCHES OF SNOW. GIVEN VERY MINIMAL EXPECTED IMPACTS
TO TRAVEL...WILL CONTINUE TO NOT MENTION SNOW IN THE HWO. DEPENDING
ON EXACT PRECIP AMOUNTS...COULD SEE SOME SIGNIFICANT RISES ON AREA
RIVERS.
ANOTHER SHOT AT GOOD ISENTROPIC ASCENT AND A STRONG SHORTWAVE ARE
SHOWN BY MODELS FOR WED AS THE UPPER LOW CONTINUES TO WEAKEN AND
BEGINS MOVING NE TOWARD THE CWA. SIGNALS FOR PRECIP AMOUNTS AND
TRENDS ARE A LOT MORE MUDDLED ON WED INTO WED NIGHT AS THE CWA WILL
BE MORE REMOVED FROM THE BEST MOISTURE TRANSPORT...WHICH WILL BE
MORE FOCUSED E AND N OF THE CWA. THINK THAT MUCH OF THE CWA WILL SEE
PRECIP...WITH POTENTIAL FOR UP TO AN INCH OF ADDITIONAL PRECIP
DURING THIS TIME PERIOD. USED A BROAD CONSENSUS OF GUIDANCE DURING
THIS PERIOD.
THE UPPER LOW WILL CONTINUE TO WEAKEN AND MOVE SLOWLY NE INTO LATE
WEEK BEFORE ADDITIONAL UPPER LEVEL ENERGY MOVES INTO THE REGION LATE
THIS WEEK INTO THE WEEKEND...LEADING TO CONTINUED WET WEATHER...BUT
AMOUNTS WILL BE LOWER THROUGH THE REST OF THE WEEK. USED A CONSENSUS
OF GUIDANCE FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 129 AM EDT MON APR 28 2014
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD UNDER MID CLOUDS.
E-NE WINDS COULD GUST NEAR 25 KT AT ALL TAF SITES AS PRES GRADIENT
TIGHTENS AHEAD OF LOW PRES OVER THE CENTRAL PLAINS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 432 PM EDT SUN APR 27 2014
EAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE DEEPENS OVER
THE PLAINS. EXPECT ENE GALES TO 35KTS OVER WESTERN LK SUPERIOR
TOWARD DULUTH INTO TUE MORNING. EAST GALES ARE THEN EXPECTED LATE
TONIGHT INTO MON OVER THE REST OF THE WESTERN LAKE. WINDS WILL
GRADUALLY DIMINISH TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH
TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER
WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE. WINDS ARE EXPECTED TO
DROP OFF TO 25 KNOTS OR LESS FROM WED INTO THU AS THE LOW FILLS AND
REMAINS NEAR UPPER MICHIGAN.
&&
.HYDROLOGY...
ISSUED AT 358 AM EDT MON APR 28 2014
RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH
THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA
STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR
ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR
CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER
NEAR NAHMA JUNCTION. AT LEAST THROUGH TONIGHT THESE RIVERS ARE NOT
EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER RIVERS WILL
START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE SYSTEM AND
WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL LIQUID
EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES BY
THURSDAY. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK. WHILE
WIDESPREAD AND AREAL FLOODING IS NOT EXPECTED...RFC ENSEMBLE
FORECASTS DO SHOW SIGNIFICANT RISES ON A FEW OF THE RIVERS IF HIGHER
QPF FROM THE MODELS VERIFIES. THOSE LIVING AROUND
RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS WEEK.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 11 AM EDT /10 AM CDT/ TUESDAY FOR LSZ162.
GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07/JV
MARINE...JLB
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
132 AM EDT MON APR 28 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 432 PM EDT SUN APR 27 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER
LEVEL TROUGH THROUGH THE NW CONUS WITH A LOW OVER WRN KS AND A
DOWNSTREAM RIDGE FROM THE SE CONUS THROUGH WRN LAKES INTO MANITOBA.
AT THE SFC...A BRISK ERLY FLOW PREVAILED THROUGH THE NRN LAKES
BETWEEN HIGH PRES OVER HUDSON BAY AND A DEEP LOW OVER NW KS. AN
INITIAL BAND OF LIGHT PCPN WAS PRODUCING MAINLY JUST SPRINKLES INTO
THE FAR WRN CWA NEAR IWD AS IT ENCOUNTERS THE VERY DRY LAYER BELOW
750 MB. HOWEVER...A MORE SUBSTANTIAL AREA OF RAIN OVER WRN INTO N
CNTRL WI...SUPPORTED BY 300K ISENTROPIC LIFT WAS LIFTING TOWARD
UPPER MI.
TONIGHT...RADAR TRENDS AND SHORT TERM MODELS SUGGEST THAT SOME LIGHT
SHOWERS WILL MOVE INTO THE WEST LATE THIS AFTERNOON AND EVENING.
HOWEVER...THERE IS A LOWER CHANCE THAT THERE WILL BE MEASURABLE PCPN
GIVEN THE AMOUNT OF DRY AIR TO OVERCOME WITH THE ERLY LOW LEVEL
INFLOW. FARTHER TO THE EAST...OVER S CNTRL UPPER MI...THE DRY
AIR...PER 12Z APX SOUNDING...SHOULD BE MORE EFFECTIVE AT SLOWING THE
ADVANCE AND REDUCING PCPN CHANCES. WITH EVAPORATIVE COOLING AT THE
LEADING EDGE OF THE PCPN...SOME SNOW OR SLEET MAY ALSO MIX IN WITH THE
RAIN LATE THIS EVENING AND OVERNIGHT...PER NAM LOW LEVEL THICKNESS
AND WET-BULB ZERO HEIGHTS.
MON...THE MODELS WERE IN SLIGHTLY BETTER AGREEMENT IN HANDLING THE
ADVANCE OF PCPN INTO UPPER MICHIGAN. THE NAM/GFS/ECMWF WERE NOW ON
THE SLOWER SIDE COMPARED TO GEM. AS THE MID/UPPER LEVEL LOW SLOWLY
WOBBLES TO THE NORTHEAST AND AN ELONGATED TROUGH/FRONT EXTENDS FROM
SRN IA INTO NRN INDIANA. ANOTHER BAND OF RAIN WILL MOVE TOWARD UPPER
MI WITH INCREASING 300K-305K ISENTROPIC ASCENT NORTH OF THE 850 MB
WARM FRONT THROUGH CNTRL WI. THERE IS STILL LIKELY TO BE SHARP
CUTOFF TO THE NRN EDGE OF THE PCPN BAND THROUGH CNTRL UPPER MI. THE
HIGHEST CHANCES WILL REMAIN ALONG THE WI BORDER WITH ONLY A SLIGHT
CHANCE OVER THE NORTH.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 432 PM EDT SUN APR 27 2014
UPPER LOW OVER THE CENTRAL PLAINS MONDAY AFTERNOON AND ASSOCIATED
SFC LOW AND WARM FRONT WILL BE MAIN FOCUS FOR THE FORECAST THIS
UPCOMING WEEK. MODELS VERY LOCKED INTO IDEA THAT WHILE WIDESPREAD
SHRA AND TSRA AND SEVERE WEATHER IMPACT MID TO LOWER MISSISSIPPI
RIVER VALLEY...ADDITIONAL SHRA/TSRA DEVELOP LATE MONDAY AFTN ALONG
WARM FRONT EXTENDING TO THE EAST OF SFC LOW OVER NEB. THIS IS IN
RESPONSE TO SHORTWAVE/PV ANAMOLY LIFTING AHEAD OF PARENT UPPER LOW.
POSSIBLE THAT ADDITIONAL SHRA WILL ALREADY BE LIFTING TOWARD UPR
MICHIGAN AS WELL DUE TO REMNANTS OF SHRA/TSRA DEVELOPING OVER THE
UPPER MISSISSIPPI RIVER VALLEY MONDAY MORNING PER SSW-NNE ORIENTED
FORWARD PROPAGATING CORFIDI VECTORS AND H85-H7 MOSITURE TRANSPORT.
AREA OF SHRA/TSRA ALONG WARM FRONT WILL GLIDE TOWARD UPR MICHIGAN
OVERNIGHT INTO TUESDAY MORNING DUE TO THE ARRIVAL OF SHORTWAVE AND
H85-H5 Q-VECTOR CONVERGENCE ALONG WITH VEERING H85-H7 FLOW FM ESE
TO MORE SSW. FOLLOWING THE Q-VECTOR CONVERGENCE AND RIBBON OF
MOISTURE TRANSPORT...EXPECT MOST PRECIPITATION TO OCCUR IN THE
MORNING. BASED ON 1000-850MB THICKNESSES/H85 TEMPS AND HEIGHT OF
WBZERO...MAY SEE SNOW OR A RAIN/SNOW MIX OVER HIGHER TERRAIN OF
WEST AND NCNTRL UPR MICHIGAN PERHAPS EVEN LINGERING INTO MID AFTN.
MINOR SNOW ACCUMULATIONS SEEM POSSIBLE...ESPECIALLY ON GRASSY
SURFACES. WILL LEAVE OUT OF HAZARDOUS WEATHER OUTLOOK FOR NOW AS
TRAVEL WOULD PROBABLY BE ONLY MINIMALLY IMPACTED. BY LATE
AFTN...EXPECT CHANGE OVER TO RAIN AS H85 TEMPS SURGE ABOVE ZERO.
THIS MAY BE OCCURRING WHEN MAJORITY OF HEAVIER PRECIPITATION IS
COMING TO AN END THOUGH. BY TUE EVENING...FORECAST SOUNDINGS SHOW
DRYING ABOVE H9...SO THERE MAY BE DRIZZLE. TEMPS WILL CONTINUE TO
RISE SFC-H85 SO BY THAT TIME WILL ONLY BE DEALING WITH LIQUID PRECIP.
ON WEDNESDAY...PRIMARY SHORTWAVE LIFTS NORTH ACROSS THE UPPER GREAT
LAKES. SEEMS TO BE A TREND FOR BEST MOISTURE TRANSPORT TO MISS UPR
MICHIGAN TO THE EAST...ALLOWING BULK OF RAIN ON WEDNESDAY TO SURGE
NORTH ACROSS THE LOWER LAKES. HOWEVER...SIGNAL THAT HIGHER THETA-E
AT H8-H7 WILL BE WRAPPING WESTWARD ACROSS UPR MICHIGAN ON CYCLONIC
NORTH SIDE OF FILLING SFC-H85 LOWS. RAIN ON WEDNESDAY WOULD ONLY BE
BOLSTERED OVER HIGHER TERRAIN OF WESTERN AND NORTH CENTRAL UPPER
MICHIGAN WITH NE BLYR WINDS. WEDNESDAY NIGHT INTO THURSDAY...THE
VERTICALLY STACKED LOW PRESSURE SYSTEM REMAINS NEARLY STATIONARY
OVER THE UPPER GREAT LAKES. UNSETTLED WEATHER PATTERN AND WILL KEEP
WITH THE CHANCES THAT CONSENSUS OF MODELS SHOWS. THE GREATEST
CHANCES OF RAIN WILL BE ALONG AND NORTH AND WEST OF H85 LOW WHERE
HIGHER THETA-E CONTINUES TO WRAP AROUND THE LOW AND ALSO WHERE
LINGERING Q-VECTOR CONVERGENCE IS LOCATED. YET...CANNOT RULE OUT
PRECIP JUST ABOUT ANYWHERE OVER THE CWA AS OTHER SHORTWAVES WILL
PROBABLY BE CYCLING AROUND THE MAIN UPPER LOW CENTER AND THERE
SHOULD BE PLENTY OF LOW-MID LEVEL MOISTURE REMAINING OVER REGION.
DO NOT EXPECT THE PRECIP THAT OCCURS BEYOND WEDNESDAY EVENING TO
BE HEAVY AS RICHER MOISTURE WILL BE HEADING WELL TO THE EAST OF
THE REGION BY THAT TIME. GRADUALLY COOLING TEMPERATURES ALOFT AND
EVENTUALLY AT THE SFC /H85 TEMPS DROPPING BLO 0C PER GFS/ECMWF/
COULD RESULT IN MIXED RAIN AND SNOW OVER PORTIONS OF CWA LATER
WEDNESDAY NIGHT INTO THURSDAY MORNING AND AGAIN THURSDAY NIGHT INTO
FRIDAY MORNING. MAY EVEN SEE MIX LATER FRIDAY NIGHT INTO SATURDAY
MORNING. ONLY SLIGHT CHANCES FOR POPS BY THAT TIME THOUGH AS
SYSTEM WILL BE UNRAVELLING AS IT LIFTS EAST AND NORTH AWAY FM LK
SUPERIOR/UPR MICHIGAN.
UPPER LEVEL TROUGH STILL FORECAST OVER THE REGION NEXT WEEKEND...SO
NO WARM UP IS IN STORE. COULD BE MORE RAIN/SNOW BY NEXT SUNDAY AS
THERE ARE HINTS OF STRONGER SYSTEM WORKING THROUGH AT THAT TIME.
HOWEVER...SINCE THE TIMING FOR THAT SYSTEM WILL BE COMPLETELY
DICTATED BY THE UPPER LOW THIS WEEK AND HOW QUICK IT DEPARTS...THERE
IS CONSIDERABLE UNCERTAINTY IN HOW ALL THESE DETAILS WILL EVENTUALLY
WORK OUT. THUS...CHANGES TO MODEL CONSENSUS BEYEOND THURSDAY WERE
MINIMAL GIVEN THE UNCERTAINTY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 129 AM EDT MON APR 28 2014
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD UNDER MID CLOUDS.
E-NE WINDS COULD GUST NEAR 25 KT AT ALL TAF SITES AS PRES GRADIENT
TIGHTENS AHEAD OF LOW PRES OVER THE CENTRAL PLAINS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 432 PM EDT SUN APR 27 2014
EAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE DEEPENS OVER
THE PLAINS. EXPECT ENE GALES TO 35KTS OVER WESTERN LK SUPERIOR
TOWARD DULUTH INTO TUE MORNING. EAST GALES ARE THEN EXPECTED LATE
TONIGHT INTO MON OVER THE REST OF THE WESTERN LAKE. WINDS WILL
GRADUALLY DIMINISH TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH
TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER
WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE. WINDS ARE EXPECTED TO
DROP OFF TO 25 KNOTS OR LESS FROM WED INTO THU AS THE LOW FILLS AND
REMAINS NEAR UPPER MICHIGAN.
&&
.HYDROLOGY...
ISSUED AT 432 PM EDT SUN APR 27 2014
RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH
THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA
STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR
ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR
CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS...AND THE STURGEON
RIVER NEAR NAHMA JUNCTION IN DELTA COUNTY. AT LEAST THROUGH MONDAY
NONE OF THESE RIVERS ARE EXPECTED TO REACH FLOOD STAGE...BUT THESE
AND OTHER RIVERS MAY START TO RISE AGAIN LATER THIS WEEK AS A LOW
PRESSURE SYSTEM AND WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN.
TOTAL LIQUID EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2
INCHES BY LATE THIS WEEK. THE PRECIPITATION WOULD ADD TO THE FLOOD
RISK...ESPECIALLY OVER THE NORTHWEST HALF OF UPPER MICHIGAN WHERE
SNOWMELT WILL ALSO ADD TO THE RUNOFF.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. HOWEVER...THOSE
LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER
LEVELS THIS WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 11 AM EDT /10 AM CDT/ TUESDAY FOR LSZ162.
GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07/JV
MARINE...JLB
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS DULUTH MN
649 PM CDT TUE APR 29 2014
.UPDATE...
ISSUED AT 430 PM CDT TUE APR 29 2014
HAVE INCREASED SNOWFALL AMOUNTS THIS EVENING FOR THE TWIN PORTS
AND I-35 CORRIDOR. THE SNOW WILL BE LOCALIZED WITH SOME AREAS
SEEING LITTLE OR NO SNOW. HOWEVER...AREAS THAT DO SEE SNOW CAN
EXPECT 1-3" OF ACCUMULATION. SNOWFALL SPOTTERS ARE REPORTING
LOCALIZED HEAVY SNOW IN THE SNOW SHOWERS CURRENTLY OVER FAR
NORTHWEST WISCONSIN.
&&
.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 311 PM CDT TUE APR 29 2014
AT 300PM/2000Z...THERE WAS A LARGE LOW PRESSURE SYSTEM CENTERED
OVER EASTERN IOWA. HIGH PRESSURE WAS CENTERED OVER HUDSON BAY AND
QUEBEC. MUCH OF THE UPPER MIDWEST HAD RAIN AND SNOW SHOWERS AND
CLOUDY SKIES...WHILE THE NORTHERN PLAINS OF NW MINNESOTA AND NORTH
DAKOTA HAD CLEAR SKIES DUE TO THE INFLUENCE OF THE CANADIAN HIGH
PRESSURE. THERE WAS LIGHT TO MODERATE RAIN AND SNOW IN NW
WISCONSIN ASSOCIATED WITH THE LOW PRESSURE SYSTEM...AND WHICH WAS
GRADUALLY MOVING WEST AND NORTHWARD INTO THE CENTRAL FORECAST
AREA. THE BAND OF RAIN AND SNOW WAS ALSO ASSOCIATED WITH A
SHORTWAVE OVER WESTERN WISCONSIN SHIFTING TO THE NORTH AND WEST.
TEMPERATURES RANGED FROM THE LOW 30S IN NW WISCONSIN AND THE
UPPER 30S TO NEAR 50 DEGREES IN NE MINNESOTA.
THE CONCERN FOR THIS EVENING IS THE CURRENT MAIN BAND OF SNOW
SHOWERS IN NW WISCONSIN...AND HOW IT WILL AFFECT OTHER AREAS AS IT
MOVES WEST. IN THIS MAIN BAND OF MAXIMIZED OMEGA...SNOW IS
FALLING FROM ALOFT AND AT FALLING AS RAIN AT FIRST ALONG ITS
WESTERN LEADING EDGE. THEN THE TEMPERATURES NEAR THE SURFACE ARE
FALLING...AND ALLOWING THE PCPN TO SWITCH FROM RAIN TO SNOW NEAR
THE SURFACE. THE RELATIVELY WARM SURFACE IS MAKING IT TAKE SOME
TIME FOR SNOW TO ACCUMULATE...ESPECIALLY ON THE ROADS. WE HAVE
GOTTEN PLENTY OF REPORTS THOUGH THAT THE SNOW IS EVENTUALLY
ACCUMULATING ON GRASS AND ROOFS AND SUCH...AND CREATING SLUSHY
ROADS. VISIBILITY IS ALSO LOW AT TIMES DURING THE HEAVIER SNOW
RATES. THIS BAND WILL BE SHIFTING INTO AREAS OF THE CENTRAL AND
WESTERN FORECAST AREA THAT HAVE GOTTEN MUCH WARMER THAN NW
WISCONSIN GOT TODAY DUE TO NW WISCONSIN BEING WET AND CLOUDY FOR
MOST OF TODAY...WHILE WESTERN AREAS REMAINED DRY. THEREFORE...I
THINK IT WILL TAKE EXTRA TIME FOR THE PCPN TO SWITCH TO SNOW AND
FOR THE SNOW TO ACCUMULATE AS IT MOVES INTO THE WESTERN FORECAST
AREA. HOWEVER...AREAS COULD SEE UP TO A COUPLE INCHES OF SNOW
ACCUMULATION. IF THE SNOW LINGERS LONG ENOUGH AND/OR FALLS HEAVY
ENOUGH...ACCUMULATION COULD BE GREATER. AT THIS POINT WE HAVE BEEN
COVERING THIS SYSTEM WITH NOWCASTS DUE TO SNOW ACCUMULATION BEING
LESS THAN 3 INCHES...BUT WE MIGHT NEED TO RECONSIDER A WINTER
WEATHER ADVISORY IF SNOWFALL AMOUNTS APPEAR TO BE MORE THAN
FORECAST.
THE HRRR HAS BEEN DOING FAIRLY WELL DEPICTING THE TIMING OF THIS
BAND OF RAIN AND SNOW...SO I LEANED ON THAT MODEL FOR MY HOURLY
FORECAST THROUGH TONIGHT.
IT APPEARS THAT HUMIDITY IN THE ICE NUCLEATION LAYER COULD
DRY UP FOR A TIME TONIGHT IN THE WAKE OF THE BAND OF PCPN...SO
PCPN COULD SWITCH FROM SNOW/RAIN TO DRIZZLE FOR A PERIOD.
HOWEVER...IT THEN APPEARS SATURATION IN THE ICE NUCLEATION LAYER
WILL INCREASE AGAIN LATE TONIGHT. THIS IS WHY I HAVE BOTH RAIN AND
SNOW IN THE FORECAST FOR MOST THE FORECAST AREA ALL THE WAY
THROUGH TONIGHT. SURFACE TEMPERATURES ARE FORECAST TO PRIMARILY BE
JUST ABOVE FREEZING TONIGHT...SO I DID NOT PUT ANY FREEZING RAIN
IN THE FORECAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 311 PM CDT TUE APR 29 2014
TIS THE SEASON...FOR ATMOSPHERIC BLOCKS THAT IS...AND THE LARGE
CLOSED LOW OVER EASTERN IOWA IS TAKING CENTER STAGE. MDLS
DISPLAY STRONG CONSENSUS THAT MID LVL FEATURE WILL MEANDER INTO
SRN MN BY WED MORNING...AND THEN SLIDE EAST TOWARDS NRN IL BY THUR
MORNING. AS THIS OCCURS...A LARGE DEEP AND MOIST CIRCULATION WILL
ENCOMPASS THE ENTIRE REGION. AS EXPRESSED IN PREVIOUS DISCUSSIONS
THIS TYPE OF SYNOPTIC PATTERN WILL GUARANTEE HIGH AMOUNTS OF CLOUD
COVER HOWEVER THE SKILL LEVEL FOR POPS IS RATHER LIMITED.
CHARACTERISTICALLY THIS TYPE OF SYSTEM WOULD EXHIBIT HIGHER POPS
DIURNALLY WITH DAYTIME CONVECTION AND MIN POPS IN THE OVERNIGHT.
HOWEVER GIVEN THE EXTENSIVE CLOUD CANOPY THE AMOUNT OF DIURNAL
INSTABILITY WILL BE LIMITED. THIS LEAVES THE POTENTIAL FOR PRECIP
TO BE MORE ALIGNED WITH MIGRATORY SHORTWAVE FEATURES ALOFT. WILL
USE A HIGH POP/LOW QPF THEME THROUGH MID DAY THURSDAY. MDLS LIFT
SYSTEM EAST FRIDAY AS AN UPSTREAM KICKER ARRIVES EMBEDDED WITHIN
THE NW FLOW. WHILE THIS SYSTEM WILL ACT TO IMPROVE THE WEATHER
INITIALLY IT WILL EVENTUALLY AMPLIFY OVERHEAD SATURDAY WHICH MAY
LEAD TO AN INCREASE IN POPS FOR THE NRN TIER OF ZONES. THERE DOES
APPEAR TO BE A MDT TO HIGH PROBABILITY THAT FAIR WX MAY RETURN BY
SUNDAY AND CONTINUE INTO NEXT WEEK BASED ON THE MID LVL FLOW WHICH
ESTABLISHES RIDGING ALOFT OVER THE NRN PLAINS. TEMPS BLO LIMO
THROUGH THE WEEK...AND THEN AIMING FOR NEAR SEASONAL VALUES EARLY
NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 643 PM CDT TUE APR 29 2014
WAVES OF RAIN...MIXED WITH SNOW AT TIMES...WILL ROTATE TO THE
NORTH AND WEST THROUGH THE TAF PERIOD. EXPECT MVFR CONDITIONS TO
PREVAIL WITH PERIODS OF IFR IN THE HEAVIER SHOWERS. LIGHT FOG/BR
AND IFR CEILINGS ARE POSSIBLE IN THE KHYR AREA OVERNIGHT...MAINLY
AFTER 06Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 34 41 36 44 / 100 80 70 60
INL 35 44 36 49 / 90 80 70 50
BRD 36 45 38 48 / 90 80 70 40
HYR 36 46 37 47 / 80 80 70 60
ASX 35 40 35 43 / 90 80 70 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT WEDNESDAY FOR LSZ121-140>148.
&&
$$
UPDATE...GRANING
SHORT TERM...GROCHOCINSKI
LONG TERM...CANNON
AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
412 PM CDT MON APR 28 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 410 PM CDT MON APR 28 2014
BIGGEST CONCERN IN THE SHORT TERM IS THE POTENTIAL FOR ACCUMULATING
SNOW LATE TONIGHT THROUGH TUESDAY AS A DEFORMATION BAND OF PRECIP
SETS UP SHOP OVER THE MPX AREA AND DOES NOT REALLY GO ANYWHERE UNTIL
WEDNESDAY.
SFC LOW AND VERTICALLY STACKED SYSTEM WAS CENTERED NEAR COLUMBUS...
NEB TO THE WEST OF OMAHA. DURING THIS PERIOD...THIS LOW WILL REMAIN
CUTOFF...WHICH MEANS IT WILL NOT BE GOING VERY FAR...MAKING IT TO
ABOUT THE IA/IL/WI BORDER BY 00Z WED. THIS WILL LEAVE US WITHIN A
WAA REGION TONIGHT...THAT WILL RATHER SEAMLESSLY TRANSITION INTO
DEFORMATION PRECIPITATION FOR TUESDAY.
AT THE START OF THIS PERIOD WE WILL HAVE A BRIEF RESPITE FROM THE
PRECIP WORK ACROSS MOST OF THE MPX CWA...THIS IS IN RESPONSE TO A
LOSS IN DEEP MOISTURE SHOWN BY THE GFS/NAM AND OTHER DETERMINISTIC
MODELS THAT IS REFLECTED IN THE HI-RES MODELS BY A LACK OF
PRECIPITATION GENERATION THROUGH ABOUT 6Z TONIGHT.
HOWEVER...CONTINUED WAA AND MOISTURE TRANSPORT WILL QUICKLY START TO
FILL IN THIS MOMENTARY BREAK THIS EVENING. FOR POP GRIDS...FOLLOWED
THE HRRR/MPXWRF FOR TRYING TO TIME THE LOWER POPS ACROSS THE AREA...
BEFORE BRINGING POPS BACK IN FROM EAST TO WEST AS DEEP MOISTURE
MAKES ITS RETURN AFTER 6Z.
GIVEN ALL OF THE CLOUD COVER...DO NOT EXPECT MUCH OF A DROP IN
TEMPERATURES TONIGHT. HOWEVER...AS THE DEFORMATION PRECIP STARTS TO
GET GOING TONIGHT...DYNAMIC COOLING OF THE ATMOSPHERE BENEATH THIS
BAND SHOWS CRITICAL TEMPS/THICKNESSES BECOMING COLD ENOUGH FOR
SNOW. LIKE THE IDEA OF THE SPC WRF FOR P-TYPE...WHICH MATCHES UP
NICELY WITH THE NAM/ECMWF. THIS SCENARIO SHOWS PRECIP STARTING TO
TURN OVER TO SNOW AFTER 9Z ACROSS CENTRAL MN. AS THE DEFORMATION
BAND GETS SETUP ACROSS MN TUESDAY MORNING...EXPECT THIS MIX OR JUST
SNOW TO BUILD SOUTH WITH THE LOW. WITHIN THE HEART OF THIS
DEFORMATION BAND...DYNAMIC COOLING MAY VERY WELL KEEP THE ATMOSPHERE
COLD ENOUGH TO KEEP THE P-TYPE AS ALL SNOW THROUGH THE DAY ON
TUESDAY. AT THE MOMENT...THERE IS GOOD MODEL AGREEMENT ON THIS
DEFORMATION BAND SETTING UP FROM AROUND THE CENTRAL MN/IA
BORDER...UP THROUGH MANKATO AND THE TWIN CITIES UP TOWARD THE
WESTERN TIP OF LAKE SUPERIOR. IT IS THIS REGION THAT COULD SEE
MAINLY SNOW TOMORROW IF THE COOLING FROM DYNAMIC LIFT WITH THE
DEFORMATION BAND IS STRONG ENOUGH. FOR NOW...BROUGHT TEMPS FOR
TOMORROW AFTERNOON WHERE THIS BAND IS EXPECTED TO SETUP DOWN INTO
THE MID 30S...COLD ENOUGH TO BRING A MENTION OF A NORTH-SOUTH
ORIENTED BAND OF RA/SN MIX THROUGH THE DAY ACROSS THE CENTER OF THE
MPX CWA. RIGHT NOW...HAVE A COUPLE INCHES OF ACCUMULATION UP AROUND
KANABEC COUNTY...BUT COULD CERTAINLY SEE MORE DEPENDING ON HOW MUCH
AND HOW LONG WE CAN THINGS COOL ENOUGH FOR SNOW. AT ANY RATE...WOULD
NOT BE AT ALL SURPRISED IF FOR MUCH OF THE DAY...FOLKS IN THE TWIN
CITIES ARE WATCHING THE FLAKES FLY AS OPPOSED TO RAIN FALL.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 410 PM CDT MON APR 28 2014
-HIGH CONFIDENCE IN PERIODS OF LIGHT RAIN /MIXED WITH WET SNOW AT
TIMES/ ACROSS THE ENTIRE FORECAST AREA THROUGH THURSDAY.
-HIGH CONFIDENCE IN BELOW NORMAL TEMPS THROUGH THE EXTENDED
MN/WI WILL BE UNDER THE INFLUENCE OF A CLOSED UPPER LOW THROUGH
THURSDAY. PERSISTENT CLOUD COVER...BREEZY WINDS...AND PERIODS OF
LIGHT RAIN ARE EXPECTED UNTIL THE SYSTEM FINALLY LIFTS OFF TO THE
NORTHEAST ON FRIDAY. THE TROUGH CURRENTLY OFF THE COAST OF NOVA
SCOTIA WILL CONTINUE TO LIFT INTO THE NORTH ATLANTIC AND GET
ABSORBED BY THE LONG WAVE TROUGH OVER NEWFOUNDLAND. THIS WILL
ALLOW THE RIDGE OVER HUDSON BAY TO WEAKEN AND SLIDE EAST.
THEREFORE...THE UPPER LOW CURRENTLY PARKED OVER NEBRASKA WILL HAVE
ROOM TO LIFT NORTH AND ACTUALLY RETROGRADE BACK TO THE NORTHWEST
ON WEDNESDAY. AS A RESULT...WE HAVE DECIDED TO FORECAST 70-90%
RAIN FOR MOST OF THE FORECAST AREA THROUGH THURSDAY. THE RAIN MAY
CLEAR FOR SEVERAL HOURS AT A TIME OR BECOME LESS WIDESPREAD IN
COVERAGE DURING THIS STRETCH...BUT WE DON`T THINK MANY LOCATIONS
WILL GO 6-12 HOURS WITHOUT SEEING AT LEAST LIGHT RAIN. THE GOOD
NEWS FOR SWOLLEN DITCHES...RIVERS AND STREAMS WILL BE A TRANSITION
TO LIGHT RAIN WITH TIME WITH LITTLE CHANCE FOR THUNDER. MANY
LOCATIONS IN MN HAVE SEEN 0.30-0.75" EVERY 6 HOURS FOR THE PAST 36
HOURS. FOR WEDNESDAY AND THURSDAY...WE THINK QPF WILL BE MORE ON
THE ORDER OF 0.05-0.15" ON A 6-HOURLY BASIS.
EVEN BEYOND THE UPPER LOW EXITING THE FORECAST AREA...NORTHWEST
FLOW AND EMBEDDED SHORTWAVES KEEP THE CHANCE FOR LIGHT RAIN /OR
BRIEF PERIODS OF LIGHT SNOW IN THE MIX/ THROUGH THE WEEKEND. THE
PRECIP CHANCES BEYOND THURSDAY ARE MORE UNCERTAIN...BUT ONE THING
THAT ISN`T UNCERTAIN IS THE LIKELIHOOD OF COOLER THAN NORMAL
TEMPS. NORMAL HIGHS ARE IN THE LOWER TO MID 60S OVER THE NEXT WEEK
AND WE SHOULD REMAIN 10 TO 20 DEGREES BELOW THAT OVER THE NEXT 7
DAYS - CONFIRMED BY BOTH THE OPERATIONAL AND ENSEMBLE GUIDANCE
FROM THE GFS AND ECMWF.
.HYDRO...ENDURED THE HEAVIEST PCPN OF THE STORM LAST 48 HRS...AND
NOW ONTO LIGHTER AMOUNTS THOUGH PRETTY CONSISTENT FOR THE NEXT FEW
DAYS. SMALLER STREAMS/TRIBS WILL BEGIN TO SLOW THEIR RISES NEXT 24
HRS...REMAINING BELOW FS. WILL CONTINUE TO WATCH SAND CREEK/JORDAN
THOUGH EXPECT IT TO QUICKLY BACK OFF NOW THAT MAIN PCPN BAND HAS
MOVED NORTH. MAINSTEM RIVERS WILL CONTINUE SLOW RISE THROUGH THE
WEEK...WITH BANKFUL BECOMING POSSIBLE ALONG MISSISSIPPI N AND S OF
TWIN CITIES. HWVR...THREAT OF REACHING FS STILL MARGINAL AT BEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1248 PM CDT MON APR 28 2014
THREE MAIN CONCERNS THIS TAF PERIOD ARE THE PRECIP BREAK COMING UP
FROM THE SOUTH...HOW FAR WEST DO VFR CIGS OVER WI MAKE INTO
MN...AND P-TYPE LATE TONIGHT/TUE MORNING. SEEING WARMING OF CLOUD
TOPS COMING UP FROM THE SOUTH...AND GFS/NAM RH TIME CROSS SECTIONS
SHOWS THIS IS ASSOCIATED WITH A MOMENTARY LOSS IN DEEP
MOISTURE...WHICH SUPPORTS THE BRIEF DRYING NOTED IN THE HIGH RES
MODELS. THEREFORE...FOLLOWED THE HRRR AND OTHER HIGH RES MODELS
WITH BRINGING A BREAK IN THE FALLING PRECIP THIS EVENING...BEFORE
EVERYTHING FILLS BACK IN TONIGHT. HOWEVER...NOT COMPLETELY SOLD ON
THIS DRYING HAPPENING AS WE WILL STILL BE WITHIN A WAA PATTERN
WITH DECENT MOISTURE TRANSPORT...SO THERE IS POTENTIAL FOR ANY
BREAK TO FILL IN RATHER QUICKLY. ALSO SEE EAST WINDS TRYING TO
BRING SOME HIGHER CIGS IN FROM CENTRAL WI...BUT RAIN MOISTENED AIR
OVER MN SEEMS TO BE PUTTING ANY HALT TO THIS. THOUGH IF THE END IN
PRECIP DOES MATERIALIZE...THEN WE COULD SEE THESE CIGS MAKE A RUN
TO ABOUT MSP/STC BEFORE PRECIP RETURNS AS MID/UPPER LEVEL MOISTURE
RETURNS. FOR P-TYPE...LIKE THE IDEA OF THE NAM AND OTHER HIRES
MODELS WITH PRECIP TURNING OVER TO SNOW UP TOWARD DULUTH/PARK
RAPIDS TONIGHT THAT WILL BUILD SOUTH INTO CENTRAL MN AFTER 9Z AS
A STRONG DEFORMATION BAND OF PRECIP SETS UP. EXPECT THE HEART OF
THIS PRECIP BAND TO SEE MAINLY SNOW DURING THE DAY ON TUESDAY. FOR
NOW...BEST CHANCE OF SNOW /AND ACCUMULATING AT THAT/ IS AT STC
DOWN TO THE WRN TWIN CITIES...BUT MSP CERTAINLY NOT OUT OF THE
WOODS. ONCE THIS DEFORMATION BAND SETS UP BY TUESDAY
MORNING...CONFIDENCE IS HIGH IN IFR CIGS/VIS DOMINATING ALL BUT
MAYBE AXN/EAU FOR MOST OF TUESDAY.
KMSP...CONFIDENCE IS MODERATE WITH MOMENTARY END TO PRECIP THIS
EVENING...BUT LOWER WITH WHEN IN IT WILL RETURN TONIGHT...BUT FEEL
ANY BREAK WILL BE DONE BY 6Z. AFTER THAT...THE QUESTION BECOMES DO
WE SWITCH OVER TO A RASN MIX OR JUST PLAIN SNOW AT SOME POINT
TUESDAY MORNING. DID INTRODUCE A MIX WITH THIS TAF. BASED ON THE
NAM...12Z MAY BE A BIT EARLY...BUT IT IS NOT ENTIRELY OUT OF THE
QUESTION THAT THE PREDOMINATE P-TYPE AT MSP FOR MUCH OF TOMORROW
WILL BE ALL SNOW. NOT EXPECTING MUCH IN THE WAY OF ACCUMS ON PAVED
SFCS...BUT IF WE DO GO MOSTLY SNOW...THAT WILL REALLY TANK THE
VSBYS TOMORROW. IF YOU ARE LOOKING FOR SOME HIGH CONFIDENCE IN
THIS TAF...LOOK NO FURTHER THAN THE WINDS.
/OUTLOOK FOR KMSP/
WED...MVFR/IFR CONDS WITH PERIODS OF -SHRA. WINDS NW 10-15 KTS.
THU...MVFR/IFR CONDS WITH PERIODS OF -SHRA. WINDS NW 10-15 KTS.
FRI...MVFR CONDS...PRECIP DECREASING. WINDS NW 10-15 KTS.
&&
.HYDROLOGY...
ISSUED AT 410 PM CDT MON APR 28 2014
ENDURED THE HEAVIEST PCPN OF THE STORM LAST 48 HRS...AND NOW ONTO
LIGHTER AMOUNTS THOUGH PRETTY CONSISTENT FOR THE NEXT FEW DAYS.
SMALLER STREAMS/TRIBS WILL BEGIN TO SLOW THEIR RISES NEXT 24
HRS...REMAINING BELOW FS. WILL CONTINUE TO WATCH SAND CREEK/JORDAN
THOUGH EXPECT IT TO QUICKLY BACK OFF NOW THAT MAIN PCPN BAND HAS
MOVED NORTH. MAINSTEM RIVERS WILL CONTINUE SLOW RISE THROUGH THE
WEEK...WITH BANKFUL BECOMING POSSIBLE ALONG MISSISSIPPI N AND S OF
TWIN CITIES. HWVR...THREAT OF REACHING FS STILL MARGINAL AT BEST.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...MPG
HYDROLOGY...CCS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
134 PM CDT MON APR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM CDT MON APR 28 2014
THE NEXT SPOKE OF 700-600MB FRONTOGENESIS/OMEGA WILL LIFT ACROSS
THE AREA THIS MORNING...AND BRING THE NEXT BOUT OF RAIN SHOWERS.
GROUND CONDITIONS ARE QUITE SATURATED...ESPECIALLY EAST OF AN
ALEXANDRIA TO MANKATO LINE...TOWARD THE TWIN CITIES AND TURTLE
LAKE WISCONSIN...WHERE RAINFALL AMOUNTS ON THE ORDER OF 1.5 TO
3 INCHES FELL OVER THE LAST 24 HOURS. UNFORTUNATELY...THIS AREA
APPEARS TO GET NAILED WITH ANOTHER 1-3 INCHES TODAY. VIEW THE
HYDROLOGY DISCUSSION BELOW FOR MORE INFORMATION ON HOW THIS WILL
IMPACT THE RIVERS AND LOW LYING AREAS.
BY LATE AFTERNOON...WE SHOULD START TO SEE SOME DRYING WORKING
INTO SOUTHERN MN...BUT THAT WILL QUICKLY FILL BACK IN WITH
PRECIPITATION THIS EVE AS THE LOW SHIFTS TO CENTRAL IA AND THE
DEFORMATION PRECIP SETS UP OVER THE AREA. COLDER AIR WILL ALSO
WORK INTO CENTRAL MN FROM THE NORTH...WHICH WILL MEAN THE
POTENTIAL FOR SNOW TO ENTER THE MIX DURING THE NIGHTTIME HOURS.
COULD SEE SOME MINOR ACCUMULATIONS ACROSS CENTRAL MN BETWEEN
MIDNIGHT AND DAYBREAK TUESDAY.
HIGHS TODAY WILL NOT GO VERY FAR...NOR WILL LOWS TONIGHT...AS
ABUNDANT LOW CLOUDS AND PRECIP LINGER.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 415 AM CDT MON APR 28 2014
MODELS REMAIN LOCKED INTO THIS VERY UNUSUAL WEATHER PATTERN AS THE
UPPER LOW CONTROLS THE UPPER MIDWEST THRU FRIDAY.
SYNOPTICALLY...THE UPPER LOW AND ASSOCIATED SFC FEATURE WILL WEAKEN
AND FILL ACROSS THE PLAINS...AND INTO THE UPPER MIDWEST AS THE MEAN
UPPER FLOW IS CUTOFF THRU THU. MODELS ARE NEARLY IDENTICAL ON THE
ORIENTATION OF THE UPPER LOW AS IT MOVES SLOWLY EASTWARD TOWARD IOWA
BY TUESDAY MORNING...THEN PIVOTS AND ROTATES ACROSS THE WESTERN
GREAT LAKES THRU THURSDAY NIGHT.
AS PREVIOUS DISCUSSED WITH CUTOFF SYSTEMS...MODELS ARE USUALLY TOO
FAST ON MOVING THEM OUT. IT USUALLY TAKES A KICKER OR SOME STRONGER
WX FEATURE TO MOVE IT ALONG. ONLY THE GFS HOLDS ONTO THE UPPER LOW A
BIT SLOWER THAN THE EC/GEM. ALTHOUGH THE KICKER WILL BE ANOTHER
SHRTWV MOVING SE ACROSS THE PLAINS OF CANADA...IT REMAINS TOO FAST
BASED ON THE ASSOCIATED BIASES OF THE MODELS. THEREFORE...THE
CONTINUED TREND OF CLOUDS...SCATTERED PRECIPITATION AND COOL CONDS
WILL REMAIN AT LEAST THRU THURSDAY. LATEST FORECAST HAS A
DIMINISHING TREND ON POPS WITH ONLY CHC/SLIGHT CHC/S BY THU/FRI. THE
DIMINISHING TREND IS BASED ON THE MAIN MOISTURE FEED CUTOFF FROM THE
GULF AND ONLY RESIDUAL MOISTURE WILL BE PRESENT AFTER MONDAY NIGHT.
ONE TREND THE MODELS HAVE INDICATED IN PREVIOUS RUNS IS THE
THICKNESS VALUES DECREASING TO CRITICAL LEVELS BY LATE
MONDAY/TUESDAY MORNING...AND ESPECIALLY WED. AS THE UPPER LOW BEGINS
TO PIVOT TUE/WED...THE AIR MASS WHICH IS CURRENTLY OVER SE
CANADA...WILL BE DRAWN WESTWARD OVER THE NORTHERN GREAT LAKES...AND
ACROSS THE UPPER MIDWEST/NORTHERN PLAINS. AS THICKNESS VALUES FALL
AND THE THERMAL COLUMN BLW 1KM HOLDS OR EVEN FALLS TO NEAR +1C...THE
RAIN WILL BEGIN TO MIX WITH SNOW. EVEN THE WRF MODELS NMM/ARW HAVE
THE PRECIPITATION TYPE MIXING OR CHANGING OVER TO SNOW TUE
MORNING...AND AGAIN TUESDAY NIGHT AS SFC TEMPS FALL INTO THE MID
30S. IT IS NOT OUT OF THE QUESTION TO SEE SOME LIGHT ACCUMULATIONS
IF ALL THE RIGHT INGREDIENTS OCCUR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1248 PM CDT MON APR 28 2014
THREE MAIN CONCERNS THIS TAF PERIOD ARE THE PRECIP BREAK COMING UP
FROM THE SOUTH...HOW FAR WEST DO VFR CIGS OVER WI MAKE INTO
MN...AND P-TYPE LATE TONIGHT/TUE MORNING. SEEING WARMING OF CLOUD
TOPS COMING UP FROM THE SOUTH...AND GFS/NAM RH TIME CROSS SECTIONS
SHOWS THIS IS ASSOCIATED WITH A MOMENTARY LOSS IN DEEP
MOISTURE...WHICH SUPPORTS THE BRIEF DRYING NOTED IN THE HIGH RES
MODELS. THEREFORE...FOLLOWED THE HRRR AND OTHER HIGH RES MODELS
WITH BRINGING A BREAK IN THE FALLING PRECIP THIS EVENING...BEFORE
EVERYTHING FILLS BACK IN TONIGHT. HOWEVER...NOT COMPLETELY SOLD ON
THIS DRYING HAPPENING AS WE WILL STILL BE WITHIN A WAA PATTERN
WITH DECENT MOISTURE TRANSPORT...SO THERE IS POTENTIAL FOR ANY
BREAK TO FILL IN RATHER QUICKLY. ALSO SEE EAST WINDS TRYING TO
BRING SOME HIGHER CIGS IN FROM CENTRAL WI...BUT RAIN MOISTENED AIR
OVER MN SEEMS TO BE PUTTING ANY HALT TO THIS. THOUGH IF THE END IN
PRECIP DOES MATERIALIZE...THEN WE COULD SEE THESE CIGS MAKE A RUN
TO ABOUT MSP/STC BEFORE PRECIP RETURNS AS MID/UPPER LEVEL MOISTURE
RETURNS. FOR P-TYPE...LIKE THE IDEA OF THE NAM AND OTHER HIRES
MODELS WITH PRECIP TURNING OVER TO SNOW UP TOWARD DULUTH/PARK
RAPIDS TONIGHT THAT WILL BUILD SOUTH INTO CENTRAL MN AFTER 9Z AS
A STRONG DEFORMATION BAND OF PRECIP SETS UP. EXPECT THE HEART OF
THIS PRECIP BAND TO SEE MAINLY SNOW DURING THE DAY ON TUESDAY. FOR
NOW...BEST CHANCE OF SNOW /AND ACCUMULATING AT THAT/ IS AT STC
DOWN TO THE WRN TWIN CITIES...BUT MSP CERTAINLY NOT OUT OF THE
WOODS. ONCE THIS DEFORMATION BAND SETS UP BY TUESDAY
MORNING...CONFIDENCE IS HIGH IN IFR CIGS/VIS DOMINATING ALL BUT
MAYBE AXN/EAU FOR MOST OF TUESDAY.
KMSP...CONFIDENCE IS MODERATE WITH MOMENTARY END TO PRECIP THIS
EVENING...BUT LOWER WITH WHEN IN IT WILL RETURN TONIGHT...BUT FEEL
ANY BREAK WILL BE DONE BY 6Z. AFTER THAT...THE QUESTION BECOMES DO
WE SWITCH OVER TO A RASN MIX OR JUST PLAIN SNOW AT SOME POINT
TUESDAY MORNING. DID INTRODUCE A MIX WITH THIS TAF. BASED ON THE
NAM...12Z MAY BE A BIT EARLY...BUT IT IS NOT ENTIRELY OUT OF THE
QUESTION THAT THE PREDOMINATE P-TYPE AT MSP FOR MUCH OF TOMORROW
WILL BE ALL SNOW. NOT EXPECTING MUCH IN THE WAY OF ACCUMS ON PAVED
SFCS...BUT IF WE DO GO MOSTLY SNOW...THAT WILL REALLY TANK THE
VSBYS TOMORROW. IF YOU ARE LOOKING FOR SOME HIGH CONFIDENCE IN
THIS TAF...LOOK NO FURTHER THAN THE WINDS.
/OUTLOOK FOR KMSP/
WED...MVFR/IFR CONDS WITH PERIODS OF -SHRA. WINDS NW 10-15 KTS.
THU...MVFR/IFR CONDS WITH PERIODS OF -SHRA. WINDS NW 10-15 KTS.
FRI...MVFR CONDS...PRECIP DECREASING. WINDS NW 10-15 KTS.
&&
.HYDROLOGY...
ISSUED AT 415 AM CDT MON APR 28 2014
24 HOUR PRECIP AMOUNTS /ENDING AT 09Z MONDAY/ INDICATE A SOLID SWATH
OF 1 TO 2.5 INCHES FELL ACROSS CENTRAL AND SOUTH CENTRAL MN AND
INTO WEST CENTRAL WI...GENERALLY EAST OF AN ALEXANDRIA TO MANKATO
LINE...ACROSS THE INTERSTATE 35 CORRIDOR AND INTO WEST CENTRAL
WISCONSIN /AS FAR EAST AS TURTLE LAKE AND NEW RICHMOND/. THIS AREA
WILL BE UNDER THE GUN AGAIN TODAY FOR ANOTHER DOUSING OF RAIN ON
THE ORDER OF 1-2 INCHES. THE IMMEDIATE CONCERN WILL BE FOR MINOR
AREAL FLOODING IN LOW LYING AREAS AND POOR DRAINAGE LOCALES. WHILE
THE BRIEF RESPITE FROM RAIN OVERNIGHT SHOULD HELP A BIT...THERE
WILL LIKELY BE SPOTS THAT HAVE PONDING ISSUES FURTHER EXACERBATED
BY TODAY/S BOUT OF RAIN. THE SECOND CONCERN HYDROLOGICALLY
SPEAKING IS WITH REGARD TO THE POTENTIAL FOR RIVER FLOODING. RISES
ON LOCAL STREAMS HAVE YIELDED SMALL RISES ON THE ST
CROIX...MISSISSIPPI... MINNESOTA...CHIPPEWA...AND CROW RIVERS AMONG
OTHERS. WILL LIKELY SEE SEVERAL SITES ALONG THESE RIVERS CREEP
TOWARD THEIR ACTION STAGES WITH THE ADDITIONAL 1 TO 2 INCHES
EXPECTED TODAY. THE SITE OF GREATEST CONCERN AT THE CURRENT TIME
IS THE MISSISSIPPI AT HASTINGS...WHICH COULD RISE ABOVE FLOOD
STAGE IF THE PRECIPITATION FORECAST WORKS OUT AS ANTICIPATED.
THANKFULLY...THE RESPONSE TIME IS NOT QUICK...SO THERE IS TIME
FOR FORECAST REFINEMENT GIVEN CURRENT INDICATIONS ARE THAT IT
WOULD NOT RISE ABOVE FS UNTIL THE 3RD OF MAY. FOR THE WI
SITES...THE CHIPPEWA AT DURAND BEARS WATCHING...BUT HAS MORE
WIGGLE ROOM GIVEN PRECIP 24 PRECIP AMOUNTS FEEDING INTO THE RIVER
WERE SLIGHTLY LOWER.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...LS
LONG TERM...JLT
AVIATION...MPG
HYDROLOGY...LS
AREA FORECAST DISCUSSION
NWS JACKSON MS
1141 AM CDT MON APR 28 2014
.UPDATE......SEVERE WEATHER OUTBREAK EXPECTED THIS AFTERNOON AND EVENING...
...SIGNIFICANT FLOODING POSSIBLE MONDAY INTO EARLY TUESDAY...
.UPDATE...NOT MANY UPDATES MADE TO GOING FORECAST AS SEVERE
WEATHER OUTBREAK REMAINS ON TRACK FOR LATE THIS MORNING AND
ESPECIALLY INTO THIS AFTERNOON AND EVENING WHERE STRONG AND POSSIBLY
LONG TRACK TORNADOES COULD OCCUR. CAUTION IS HIGHLY ADVISED FOR
THIS POTENTIALLY LIFE THREATENING AND DANGEROUS SITUATION.
.DISCUSSION...INITIAL LEAD S/WV RESPONSIBLE FOR THIS MORNINGS ACTIVELY
IS LIFTING NE AWAY FROM THE REGION RESULTING IN A WEAKENING TREND OF
THAT ACTIVITY. HOWEVER, A CYCLONICALLY CURVED H5-H3 JET STREAK IS
OBSERVED ON WV CHANNELS...REGIONAL VAD WIND PROFILES AND IN NWP
SURGING INTO THE NW DELTA AND THE ARKLAMISS AT THIS HOUR. THIS
SIGNATURE COUPLED WITH NEAR 2000 J/KG SBCAPE IS ALREADY INITIALIZING
ACROSS THE DELTA REGION WITH THE THIS NEXT AND MORE POTENT ROUND OF
SEVERE WEATHER EXPECTED FOR THE REGION. 0-1 KM ESRH REMAINS NEAR
200M2/S2 PER MESOANALYSIS AS OF 16Z BUT NWP SUITE SUGGESTS STEADILY
INCREASING LOW LVL SHEAR VALUES TOWARDS 300M2/S2 AND POSSIBLY HIGHER
THROUGH THE EARLY AFTN AND EVENING WHERE WORRISOME 0-1 KM EHI AND
STRONG TORNADO PARAMETERS VALUES INDICATE HEALTHY ENVIRONMENT CAPABLE
OF SUPPORTING SOME STRONG AND POSSIBLY LONG TRACK TORNADOES. SPC SSEO
UPDRAFT HELICITY SIGNALS SUGGEST THAT GREATEST RISK FOR THESE
TORNADOES COULD BE ACROSS NORTH CENTRAL AND NORTHEAST MISSISSIPPI
EXTENDING ALONG THE NATCHEZ TRACE CORRIDOR TOWARDS THE JACKSON
METROPLEX MID TO LATE AFTERNOON INTO THE EVENING. A COUPLE OF ROUGE
STORMS COULD ALSO DEVELOP SOUTH OF I-20 AND WITH LESS COMPETITION FOR
RESOURCES AND POTENTIALLY NON-BLOCKED INFLOW COULD BE TROUBLESOME.
THE TRENDS OF LOCAL WRF AND THE HRRR ECHO SPC SSEO HELICITY SIGNALS
THAT WHAT SEMI-DISCRETE STORMS DEVELOP WILL BE CAPABLE OF STRONG
ROTATING UPDRAFTS. NAM BUFR SOUNDINGS FOR JACKSON FOR MID AFTN
SUGGEST 0-3 SRH VALUES NEAR 500 M2/S2 WITH THIS ENVIRONMENT LIKELY IN
PLACE ALONG THE TRACE CORRIDOR. GRAPHICS HAVE BEEN UPDATED TO
REFLECT THIS HIGHER RISK AREA.
UPDATES ARE OUT AND AN UPDATED AVIATION DISCUSSION CAN BE FOUND
DIRECTLY BELOW. /ALLEN/
&&
.AVIATION...MVFR CIGS WERE STILL BEING REPORTED AT 15Z IN THE SOUTH
BUT CIGS SHOULD RISE ABOVE 3KFT BY 17Z AREAWIDE. BREEZY SOUTH WINDS
OF 15-20KTS WITH GUSTS 30KTS AWAY FROM STORMS TODAY. CONDITIONS
COULD DETERIORATE THIS AFTN INTO THE EVENING AS WIDESPREAD
TSTMS...SOME SEVERE WL BE PSBL. AWAY FROM STORMS...MVFR CIGS WL
REDEVELOP TONIGHT AREAWIDE. STRONGER SW WINDS AND ANOTHER ROUND OF
POTENTIALLY SEVERE TSTMS ARE EXPECTED TUESDAY...ESPECIALLY OVER THE
SE HALF OF THE AREA. /22/
&&
.PREV DISCUSSION... /ISSUED 350 AM CDT MON APR 28 2014/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT
SEVERAL ROUNDS OF SIGNIFICANT SEVERE WEATHER HAZARDS ARE EXPECTED TO
IMPACT THE REGION TODAY THROUGH TUESDAY ALONG WITH SOME POSSIBLE
SIGNIFICANT FLOODING FROM HEAVY RAINFALL. TODAY STILL LOOKS TO BE
PARTICULARLY VOLATILE...ESPECIALLY WITH THE STRONG SHEAR IN PLACE.
THE LATEST SATELLITE IMAGERY SHOWED A STRONG CLOSED STORM
CIRCULATION OVER THE CENTRAL PLAINS AROUND NEBRASKA WITH SEVERE
CONVECTION PUSHING ACROSS THE ARKLATEX. A SERIES OF VORT LOBES
WERE ROTATING AROUND THE CLOSED STORM SYSTEM WHICH WAS BRINGING
ASCENT FOR CONVECTIVE FORMATION. A STRONG JET STREAM WAS PIVOTING
AROUND THE SOUTHERN AXIS OF THE CLOSED SYSTEM. THERE WAS AN
ASSOCIATED 985 MB SURFACE LOW WITH AS ASSOCIATED COLD FRONT AND DRY
LINE EXTENDING DOWN INTO TEXAS. WE WERE IN THE WARM SECTOR WITH
DEWPOINTS IN THE MID 60S TO AROUND 70. THE ATMOSPHERE HAD GOOD JET
DYNAMICS ...STRONG VERTICAL SHEAR(EFFECTIVE BULK SHEAR 40-60 KNOTS
AND INSTABILITY IN PLACE FOR MULTIPLE ROUNDS OF A SEVERE WEATHER
OUTBREAK FOR FOR TODAY THROUGH TUESDAY.
FOR TODAY A STRONG SHORTWAVE WILL ROTATE AROUND THE CLOSED SYSTEM
WHILE THE STORM SYSTEM WILL CONTINUE TO DEEPEN. HEIGHT FALLS...
STRONG LAPSE RATES...STRONG DYNAMIC SHEAR AND INSTABILITY WILL
PUSH INTO THE REGION. THIS COULD HELP SEVERE CONVECTION TO DEVELOP
ACROSS THE WEST EARLY AND SPREAD ACROSS THE REGION DURING THE DAY.
THE BROKEN LINE OF DISCRETE SUPERCELL STORMS TO THE WEST WILL PUSH
ACROSS THE REGION TODAY. THE MODEL SOUNDINGS CONTINUE TO SHOW
IMPRESSIVE SIGNATURES FOR ALL MODES OF SEVERE WEATHER FOR TODAY
THROUGH TUESDAY INCLUDING THE RISK OF SOME STRONG TORNADOES. THE
FIRST ROUND WILL AFFECT THE WESTERN AREAS THIS MORNING AND MARCH
ACROSS THE REGION DURING THE DAY. THE SURFACE BOUNDARY/DRYLINE WILL
BE SLOWLY APPROACHING FROM THE WEST. LATEST SPC WRF SHOWS SOME STRONG
MAXIMUM UPDRAFT HELICITY VALUES WITH THESE STORMS. AS WE GO INTO
TONIGHT EXPECT SOME MORE DEVELOPMENT FROM THE WEST. ALOT WILL DEPEND
HOW THE CONVECTIVE FEATURES WILL DEVELOP DURING THE PERIOD FOR BRIEF
PERIODS OF LULLS BETWEEN ROUNDS OF SEVERE WEATHER. SPC HAS PUT MOST
OF THE REGION UNDER A MODERATE RISK FOR DAY ONE. ALSO THE LOCAL WRF
SHOWS IMPRESSIVE UPDRAFT HELICITY IN THE NORTHEAST FOR LATE THIS
AFTERNOON WITH THESE STORMS FROM DISCRETE SUPERCELLS.
HEAVY RAIN WILL ALSO BE A CONCERN FOR TODAY THROUGH EARLY TUESDAY
WITH STRONG UPPER DIVERGENCE. MODELS SOUNDINGS AND CROSS SECTIONS SHOWS
STRONG ASCENT FOR THE INFLOW OF GULF MOISTURE WITH PWATS AROUND 1.8
INCHES. THE DAY ONE GRAPHIC FOR EXCESSIVE RAIN SHOWS A MODERATE RISK
ACROSS MOST OF THE AREA. SOME OF THE WRF MODELS SHOWS SOME POSSIBLE
TRAINING ACROSS SOME OF OUR RIVER BASINS. CORFIDI VECTORS SHOWS SOME
RIDGING MOVING ACROSS THE REGION FOR SOME TRAINING OF CELLS FOR HEAVY
RAINFALL AND SOME POSSIBLE BACKBUILDING. WPC SHOWS 2 TO 4 INCH
RAINFALL AMOUNTS ACROSS THE REGION. SO WITH THAT IN MIND HAVE
EXPANDED THE TIME OF THE CURRENT WATCH AS WELL AS ADDED THE SOUTHEAST
PORTION OF THE REGION AT 22Z UNTIL 12Z TUESDAY.
FOR TUESDAY AND TUESDAY NIGHT...ANOTHER STRONG SHORTWAVE WILL ROTATE
AROUND THE CLOSED SYSTEM OVER NORTHERN MISSOURI. MODELS SHOWS THAT THE
LOW LEVEL INFLOW WILL WEAKEN SOME IN THE LOW LEVELS OF 850 MBS AND
BELOW. THIS WILL WEAKEN THE BULK SHEAR SOME IN THE 1 AND 2 KM LAYER.
HOWEVER THE DEEP LAYER SHEAR 0-6 KM WILL MAKE UP FOR IT WITH READINGS
FROM 60 TO NEAR 100 KNOTS. THIS COMBINED WITH STRONG INSTABILITY WILL
KEEP ALL MODES OF SEVERE WEATHER ON TRACK. THE SURFACE BOUNDARY WILL
MOVE THROUGH THE REGION TUESDAY AFTERNOON AND EVENING. EXPECT THE
BULK OF THE SEVERE WEATHER TO AFFECT MAINLY THE EAST HALF OF THE
REGION AND EXIT OUT OF THE ARKLAMISS BY EARLY TUESDAY EVENING.
AS FAR AS TEMPS ARE CONCERN WENT CLOSE TO GMOS TEMPS FOR DAILY HIGHS AND
CLOSE TO CURRENT FORECAST FOR NIGHTLY LOWS. MOS GUIDANCE LOOKED A LITTLE
COOL FOR THE NIGHTLY LOWS./17/
LONGTERM...WEDNESDAY THROUGH SUNDAY...DESPITE CONTINUED MID/UPPER
LEVEL SW FLOW STILL STREAMING MOISTURE OVER THE REGION WED/THU...LOW
LEVEL NORTHERLY FLOW BEHIND SURFACE BOUNDARY...BY NOW OVER AL...WILL
HAVE SCOURED OUT MAJORITY OF APPRECIABLE MOISTURE. WHILE BOTH THE
GFS AND ECMWF SHOW THIS SCENARIO...GFS MOS WANTS TO PAINT SLIGHT
POPS FOR MUCH OF THE PERIOD WITH NO QPF AT ALL. DO AGREE THAT THERE
WILL BE SOME SLIGHT CHANCE FOR PASSING MID LEVEL WAVE ON
FRIDAY...BUT NOT ALL DURING THE WEEK LEADING UP TO THEN. HAVE CUT
POPS FOR WED/THU AND AGAIN SAT/SUN AS PATTERN JUST DOES NOT LOOK
CONDUCIVE FOR APPRECIABLE...IF ANY...PRECIPITATION. ECMWF SHOWING
SOME CAPES AROUND 500 J/KG AVAILABLE FOR FRIDAY AFTERNOON...WILL ADD
SOME POSSIBILITY FOR THUNDER TO THE EXPECTED SHOWERS.
TEMPS DURING THIS TIMEFRAME WILL BE UNSEASONABLY COOL AND SOME 10 TO
15 DEGREES BELOW NORMAL. DESPITE THE COOL NIGHTTIME LOWS IN THE
40S...TEMPS STILL WILL BE JUST A LITTLE BIT TOO WARM FOR FROST
CONCERNS./26/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 85 68 83 55 / 76 90 59 29
MERIDIAN 85 66 84 55 / 56 100 73 51
VICKSBURG 85 66 82 54 / 84 82 44 22
HATTIESBURG 86 69 85 60 / 40 100 55 31
NATCHEZ 84 69 83 54 / 72 81 36 15
GREENVILLE 83 63 79 52 / 87 79 49 23
GREENWOOD 82 65 81 53 / 86 99 61 28
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR MSZ018-019-025>052.
FLASH FLOOD WATCH FROM 5 PM CDT THIS AFTERNOON THROUGH TUESDAY
MORNING FOR MSZ055>058-063>066-072>074.
LA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR LAZ007>009-015-016.
AR...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR ARZ074-075.
&&
$$
ALLEN/22/17/26
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1136 AM CDT Mon Apr 28 2014
.UPDATE:
Issued at 1135 AM CDT Mon Apr 28 2014
Large cumulus field has recently developed across central Missouri
in convergence zone just ahead of surface cold front/dryline.
Environment is becoming increasing unstable with latest 16Z SPC
MLCAPES showing 500-1000 J/kg over central and eastern Missouri
with little CINH right ahead of the front. Current thinking is
that thunderstorms will develop in the next hour or two right
ahead of the the front and move east and northeast across eastern
Missouri into Illinois during the afternoon hours. Severe threat
including hail and damaging winds continues given the increasing
instability and impressive deep layer shear. Also, 0-1km SRH
values are currently between 100 and 250 across eastern Missouri
and Illinois support an isolated tornado risk.
Britt
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 152 AM CDT Mon Apr 28 2014
Latest HRRR weakens most of the convection currently across our
forecast area, or shifts it southeast of the region by 12z Monday.
There may be a brief lull in the convection early this morning, then
new convection should break out late this morning and early this
afternoon from Edina to Quincy and south through the St Louis metro
area to the FAM area, then shift eastward through our IL counties
later this afternoon. This will occur as a shortwave ejects out of
the southern Plains into southeast MO and a cold front/dry line
surges eastward into eastern MO by 00z Tue. Should have CAPEs up to
2000-2500 J/Kg ahead of the cold front around 18z Monday with
surface LI values down to around -10. Strongest low-mid level wind
shear should be across southeast MO and southwest IL with strong
500 mb wind max moving through AR into portions of southeast MO,
southern IL, and western portions of TN and KY. The severe weather
threat should be over the eastern portion of our area, in portions
of west central and southwest IL with the primary threat being large
hail and damaging winds. This will occur from the late morning,
through the afternoon and into the early evening hours.
GKS
.LONG TERM: (Tonight through Sunday)
Issued at 341 AM CDT Mon Apr 28 2014
The showers and thunderstorms should be confined to areas east of
the Mississippi River this evening and should be weakening by late
evening as the higher surface dewpoints and instability shifts east
of our forecast area. Little if any precipitation should be left
late tonight. Temperatures will be cooler tonight due to low level
cold air advection in our area south of the upper level and
associated surface low. More showers and a few thunderstorms on
Tuesday as the moisture wraps around the slow moving upper/surface
low north of our area. The best chance for rain will be across the
northwest half of our forecast area. The models keep the showers
going Tuesday night as shortwaves rotate around the mid-upper level
low. The gradual cooling trend will continue with well below normal
temperatures for Wednesday and Wednesday night. The GFS and ECMWF
models drop the zero degree C 850 mb isotherm southeastward into our
forecast area Tuesday night or Wednesday, the cooler NAM even
earlier. Although there will likely be rain across our area again
on Wednesday it should be on the light side. The rain should be
mainly diurnal on Thursday and Friday and favor the northern portion
of our forecast area as the upper level low weakens and moves into
the Great Lakes region. Will see warmer high temperatures for the
weekend as the upper level heights begin to rise and southerly
surface/low level flow returns Saturday night. Low-mid level warm
air advection ahead of a weak shortwave and associated surface low
may bring showers to the extreme northern portion of our forecast
area late Saturday night and Sunday.
GKS
&&
.AVIATION: (For the 12z TAFs through 12z Tuesday Morning)
Issued at 633 AM CDT Mon Apr 28 2014
VFR conditions outside of TSRA will prevail at the TAF sites thru
the valid period. Another round of TSRA is expected to develop
mainly east of the MS river around midday, leaving UIN and the STL
Metro sites on the backedge of what does form. Due to these TAF
sites being on the backedge, have elected to keep VCTS mention
versus TEMPO until we get closer to initiation time. What does
develop should shove off to the northeast by late afternoon. Gusty
southerly winds are expected, diminishing tonight.
Specifics for KSTL: VFR outside of TSRA thru the valid period.
Another round of TSRA is expected to develop over the STL Metro
area around midday with what does form shoving off to the
northeast by mid-afternoon. Due to the terminal anticipated to
being on the backedge, have elected to keep VCTS mention versus
TEMPO until we get closer to initiation time. Gusty southerly
winds are expected, diminishing tonight.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
633 AM CDT Mon Apr 28 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 152 AM CDT Mon Apr 28 2014
Latest HRRR weakens most of the convection currently across our
forecast area, or shifts it southeast of the region by 12z Monday.
There may be a brief lull in the convection early this morning, then
new convection should break out late this morning and early this
afternoon from Edina to Quincy and south through the St Louis metro
area to the FAM area, then shift eastward through our IL counties
later this afternoon. This will occur as a shortwave ejects out of
the southern Plains into southeast MO and a cold front/dry line
surges eastward into eastern MO by 00z Tue. Should have CAPEs up to
2000-2500 J/Kg ahead of the cold front around 18z Monday with
surface LI values down to around -10. Strongest low-mid level wind
shear should be across southeast MO and southwest IL with strong
500 mb wind max moving through AR into portions of southeast MO,
southern IL, and western portions of TN and KY. The severe weather
threat should be over the eastern portion of our area, in portions
of west central and southwest IL with the primary threat being large
hail and damaging winds. This will occur from the late morning,
through the afternoon and into the early evening hours.
GKS
.LONG TERM: (Tonight through Sunday)
Issued at 341 AM CDT Mon Apr 28 2014
The showers and thunderstorms should be confined to areas east of
the Mississippi River this evening and should be weakening by late
evening as the higher surface dewpoints and instability shifts east
of our forecast area. Little if any precipitation should be left
late tonight. Temperatures will be cooler tonight due to low level
cold air advection in our area south of the upper level and
associated surface low. More showers and a few thunderstorms on
Tuesday as the moisture wraps around the slow moving upper/surface
low north of our area. The best chance for rain will be across the
northwest half of our forecast area. The models keep the showers
going Tuesday night as shortwaves rotate around the mid-upper level
low. The gradual cooling trend will continue with well below normal
temperatures for Wednesday and Wednesday night. The GFS and ECMWF
models drop the zero degree C 850 mb isotherm southeastward into our
forecast area Tuesday night or Wednesday, the cooler NAM even
earlier. Although there will likely be rain across our area again
on Wednesday it should be on the light side. The rain should be
mainly diurnal on Thursday and Friday and favor the northern portion
of our forecast area as the upper level low weakens and moves into
the Great Lakes region. Will see warmer high temperatures for the
weekend as the upper level heights begin to rise and southerly
surface/low level flow returns Saturday night. Low-mid level warm
air advection ahead of a weak shortwave and associated surface low
may bring showers to the extreme northern portion of our forecast
area late Saturday night and Sunday.
GKS
&&
.AVIATION: (For the 12z TAFs through 12z Tuesday Morning)
Issued at 633 AM CDT Mon Apr 28 2014
VFR conditions outside of TSRA will prevail at the TAF sites thru
the valid period. Another round of TSRA is expected to develop
mainly east of the MS river around midday, leaving UIN and the STL
Metro sites on the backedge of what does form. Due to these TAF
sites being on the backedge, have elected to keep VCTS mention
versus TEMPO until we get closer to initiation time. What does
develop should shove off to the northeast by late afternoon. Gusty
southerly winds are expected, diminishing tonight.
Specifics for KSTL: VFR outside of TSRA thru the valid period.
Another round of TSRA is expected to develop over the STL Metro
area around midday with what does form shoving off to the
northeast by mid-afternoon. Due to the terminal anticipated to
being on the backedge, have elected to keep VCTS mention versus
TEMPO until we get closer to initiation time. Gusty southerly
winds are expected, diminishing tonight.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
342 AM CDT Mon Apr 28 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 152 AM CDT Mon Apr 28 2014
Latest HRRR weakens most of the convection currently across our
forecast area, or shifts it southeast of the region by 12z Monday.
There may be a brief lull in the convection early this morning, then
new convection should break out late this morning and early this
afternoon from Edina to Quincy and south through the St Louis metro
area to the FAM area, then shift eastward through our IL counties
later this afternoon. This will occur as a shortwave ejects out of
the southern Plains into southeast MO and a cold front/dry line
surges eastward into eastern MO by 00z Tue. Should have CAPEs up to
2000-2500 J/Kg ahead of the cold front around 18z Monday with
surface LI values down to around -10. Strongest low-mid level wind
shear should be across southeast MO and southwest IL with strong
500 mb wind max moving through AR into portions of southeast MO,
southern IL, and western portions of TN and KY. The severe weather
threat should be over the eastern portion of our area, in portions
of west central and southwest IL with the primary threat being large
hail and damaging winds. This will occur from the late morning,
through the afternoon and into the early evening hours.
GKS
.LONG TERM: (Tonight through Sunday)
Issued at 341 AM CDT Mon Apr 28 2014
The showers and thunderstorms should be confined to areas east of
the Mississippi River this evening and should be weakening by late
evening as the higher surface dewpoints and instability shifts east
of our forecast area. Little if any precipitation should be left
late tonight. Temperatures will be cooler tonight due to low level
cold air advection in our area south of the upper level and
associated surface low. More showers and a few thunderstorms on
Tuesday as the moisture wraps around the slow moving upper/surface
low north of our area. The best chance for rain will be across the
northwest half of our forecast area. The models keep the showers
going Tuesday night as shortwaves rotate around the mid-upper level
low. The gradual cooling trend will continue with well below normal
temperatures for Wednesday and Wednesday night. The GFS and ECMWF
models drop the zero degree C 850 mb isotherm southeastward into our
forecast area Tuesday night or Wednesday, the cooler NAM even
earlier. Although there will likely be rain across our area again
on Wednesday it should be on the light side. The rain should be
mainly diurnal on Thursday and Friday and favor the northern portion
of our forecast area as the upper level low weakens and moves into
the Great Lakes region. Will see warmer high temperatures for the
weekend as the upper level heights begin to rise and southerly
surface/low level flow returns Saturday night. Low-mid level warm
air advection ahead of a weak shortwave and associated surface low
may bring showers to the extreme northern portion of our forecast
area late Saturday night and Sunday.
GKS
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1147 PM CDT Sun Apr 27 2014
Back edge of storms slowly making their way east. Precipitation
should come to an end at KCOU by taf issuance time. As for rest of
taf sites, kept mention of showers and thunderstorms through about
08z Monday. Mvfr/ifr cigs/vsbys expected with the heavier
activity, otherwise vfr conditions to prevail. Next round of
activity will be with main cold front later today, though they
will fire up just east of KCOU, so kept them dry. As for rest of
taf sites, added vcnty TS mention after 17z then coming to an end
by 23z. As for winds, to prevail from the southeast to south
before veering to the southwest behind the cold front. Could see
winds pickup by 17z with gusts to near 25 kts at times before
diminishing this evening.
Specifics for KSTL:
Back edge of storms slowly making their way east. Precipitation
should come to an end through about 08z. Mvfr/ifr cigs/vsbys
expected with the heavier activity, otherwise vfr conditions to
prevail. Next round of activity will be with main cold front later
today, so added vcnty TS mention after 17z then coming to an end
by 23z. As for winds, to prevail from the southeast to south
before veering to the southwest behind the cold front. Could see
winds pickup by 17z with gusts to near 25 kts at times before
diminishing this evening.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
154 AM CDT Mon Apr 28 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 152 AM CDT Mon Apr 28 2014
Latest HRRR weakens most of the convection currently across our
forecast area, or shifts it southeast of the region by 12z Monday.
There may be a brief lull in the convection early this morning, then
new convection should break out late this morning and early this
afternoon from Edina to Quincy and south through the St Louis metro
area to the FAM area, then shift eastward through our IL counties
later this afternoon. This will occur as a shortwave ejects out of
the southern Plains into southeast MO and a cold front/dry line
surges eastward into eastern MO by 00z Tue. Should have CAPEs up to
2000-2500 J/Kg ahead of the cold front around 18z Monday with
surface LI values down to around -10. Strongest low-mid level wind
shear should be across southeast MO and southwest IL with strong
500 mb wind max moving through AR into portions of southeast MO,
southern IL, and western portions of TN and KY. The severe weather
threat should be over the eastern portion of our area, in portions
of west central and southwest IL with the primary threat being large
hail and damaging winds. This will occur from the late morning,
through the afternoon and into the early evening hours.
GKS
.LONG TERM: (Monday through Next Sunday)
Issued at 355 PM CDT Sun Apr 27 2014
Mon...Thunderstorms are expected to develop on Mon ahead of
the approaching cold front/dryline. Favorable environmental
parameters for severe weather include H7-H5 lapse rates of 7-8 deg
C/km, 0-6km bulk shear of 40-70 kts, and at least 1000 J/kg of
CAPE. The greatest threat appears to be across the eastern half of
the CWA during the afternoon hours when this area will be beneath
the left exit region of an upper jet streak.
Tue through Thu...With cold temperatures aloft creating steep lapse
rates, cyclonic flow aloft, multiple shortwaves rotating through the
trough, and fairly low freezing levels, this looks like a good
pattern for diurnally-driven afternoon SHRA/TSRA with small hail.
Pcpn coverage should diminish quickly after sunset each day. Expect
daily temperatures to be 10-15 degrees cooler than average during
this period.
Fri through Sat...Although the approximate center of the large
upper low is forecast to have moved north and east of MO/IL by
Fri, models show that a broad trough remains in place with several
shortwaves moving through the flow. These disturbances could
support SHRA/TSRA at times.
Kanofsky
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1147 PM CDT Sun Apr 27 2014
Back edge of storms slowly making their way east. Precipitation
should come to an end at KCOU by taf issuance time. As for rest of
taf sites, kept mention of showers and thunderstorms through about
08z Monday. Mvfr/ifr cigs/vsbys expected with the heavier
activity, otherwise vfr conditions to prevail. Next round of
activity will be with main cold front later today, though they
will fire up just east of KCOU, so kept them dry. As for rest of
taf sites, added vcnty TS mention after 17z then coming to an end
by 23z. As for winds, to prevail from the southeast to south
before veering to the southwest behind the cold front. Could see
winds pickup by 17z with gusts to near 25 kts at times before
diminishing this evening.
Specifics for KSTL:
Back edge of storms slowly making their way east. Precipitation
should come to an end through about 08z. Mvfr/ifr cigs/vsbys
expected with the heavier activity, otherwise vfr conditions to
prevail. Next round of activity will be with main cold front later
today, so added vcnty TS mention after 17z then coming to an end
by 23z. As for winds, to prevail from the southeast to south
before veering to the southwest behind the cold front. Could see
winds pickup by 17z with gusts to near 25 kts at times before
diminishing this evening.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1227 AM CDT MON APR 28 2014
.SYNOPSIS...
ISSUED AT 407 PM CDT SUN APR 27 2014
A POTENT...UPPER LEVEL LOW WAS CENTERED OVER WESTERN KS
THIS AFTERNOON. A NICE JET STREAK EXTENDED FROM NORTHERN
CALIFORNIA...AROUND THE BASE OF THE LOW...NOSING INTO CENTRAL KS.
DOWNSTREAM OF THE TROUGH...A HIGH AMPLITUDE...NEGATIVE TILTED RIDGE
EXTENDED FROM THE SERN STATES INTO NRN MANITOBA. AT THE
SURFACE...LOW PRESSURE WAS NOTED OVER GOODLAND KS WITH A COLD FRONT
EXTENDING SSW INTO NERN NEW MEXICO. AN INVERTED TROUGH AXIS EXTENDED
NORTH OF THE LOW ALONG THE COLORADO/KS BORDER INTO THE NEBRASKA
PANHANDLE. WEST OF THIS INVERTED TROUGH...TEMPS WERE IN THE LOWER TO
MID 40S...WHILE EAST OF THE TROUGH AXIS...TEMPS WERE IN THE 60S AND
70S. A DRY LINE...EXTENDED NORTH OF THE SURFACE LOW INTO SWRN
NEBRASKA...WHERE IT TURNED SOUTHEAST INTO SOUTH CENTRAL NEBRASKA.
THUNDERSTORMS HAVE FIRED ALONG THE DRYLINE THIS AFTERNOON WITH THE
TORNADIC THREAT GENERALLY IN SOUTH CENTRAL NEBRASKA WHERE BETTER
DIRECTIONAL SHEAR EXISTS. FURTHER NORTH ACROSS THE CENTRAL AND
NORTHERN SANDHILLS...GOOD SPEED SHEAR EXISTS...HOWEVER DIRECTIONAL
SHEAR IS LACKING PER LATEST KLNX VAD WIND PROFILER. IN THESE
AREAS...STRONG TO SEVERE STORMS HAVE OCCURRED WITH LARGE HAIL BEING
THE MAIN SEVERE THREAT.
&&
.UPDATE...
ISSUED AT 1225 AM CDT MON APR 28 2014
CURRENT UPDATE TO ACCOUNT FOR SNOW INTO PERKINS COUNTY. LAYING
DOWN SOME SNOW ON NDOR CAMERAS.
UPDATE ISSUED AT 1027 PM CDT SUN APR 27 2014
THE HIGH WIND WATCH HAS BEEN UPGRADED TO A HIGH WIND WARNING BASED
ON THE RAP AND 00Z NAM MODEL RUNS WHICH KEEP THE STRONGEST WINDS
ALONG HIGHWAY 61. THE AREA TO WATCH IS THE CENTRAL SANDHILLS WHERE
THE RAP AND NAM SHOW VERY STRONG 500M AGL WINDS APPROACHING 40 MPH
AT THE SFC MONDAY AFTERNOON.
NOTE THE FORECAST CONTINUES STRONG OR HIGH WINDS MONDAY NIGHT AND
TUESDAY WHICH WOULD NECESSITATE EXTENSIONS OF THE ON GOING HIGH
LIGHTS.
UPDATE ISSUED AT 837 PM CDT SUN APR 27 2014
A LOOK AT THE NEBRASKA DOR CAMS AND THE RAP MODEL SUGGEST WINTER
WEATHER ADVISORY CONDITIONS ACROSS SHERIDAN AND WESTERN CHERRY
COUNTIES. THE RAP INDICATES SEVERAL INCHES OF WET SNOW THIS
EVENING WHICH TAPERS OFF OR MIXES WITH RAIN AFTER MIDNIGHT. RADAR
INDICATES A DEFORMATION ZONE UNDERWAY ACROSS THIS AREA BUT MAINLY
ACROSS NRN SHERIDAN COUNTY. A WINTER ADVISORY IS IN PLACE FOR
THESE AREA AND IT OPERATES UNTIL 13Z.
THE FORECAST UPDATE FOLLOWS 50 PERCENT OF THE 23Z RAP AND 50
PERCENT OF THE PREVIOUS FORECAST. THE PTYPE USES THE RAP MODEL
WHICH SPREADS WET SNOW AS FAR SOUTH AS DEUEL COUNTY BUT LITTLE
ACCUMULATION IS EXPECTED THAT FAR SOUTH. IT LOOKS LIKE THE FAVORED
AREA FOR SNOW IS NORTHWEST NEBRASKA...NORTH OF THE NORTH PLATTE
VALLEY FOLLOWING THE H750 MB FRONT WHICH IS STRONGLY STACKED AND
MOVING VERY SLOWLY EAST TONIGHT. NOTE THE 23Z RAP PRODUCES OVER 1
INCH OF QPF ACROSS SHERIDAN COUNTY TONIGHT. THE FORECAST USES A
RATIO OF 6 TO 1 FOR 3 TO NEARLY 8 INCHES OF SNOW FAVORING PINE
RIDGE.
&&
.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 407 PM CDT SUN APR 27 2014
FORECAST CONCERNS CONTINUE WITH THUNDERSTORM CHANCES TONIGHT...THEN
LEAD TO FORMATION OF DEFORMATION BAND AND SNOW POTENTIAL.
THE UPPER LOW WAS CENTERED OVER NORTHWEST KANSAS AS OF 20Z...WITH
THE SURFACE CIRCULATION ALMOST DIRECTLY OVER KCBK.
WITH THE SYSTEM BEING NEARLY VERTICALLY STACKED OVER NORTHWEST
KANSAS THIS AFTERNOON...THERE IS CONCERN THAT THE MODELS MAY BE
TRYING TO KICK THE SYSTEM EAST TOO QUICKLY THIS EVENING AND
OVERNIGHT. THIS WILL IMPACT THE AREAS THAT CONTINUE TO SEE
CONVECTION...WHERE THE PRECIPITATION FALLS...WHERE THE WINDS
STRENGTHEN...AND WHERE AND WHEN THE RAIN SWITCHES OVER TO SNOW.
THE LATEST RAP MODEL MOVES THE SURFACE CIRCULATION TO NEAR KMCK BY
00Z THIS EVENING THEN OVER KHSI AT 06Z AND THEN MOVES IT UP TO
AROUND KBVN BY 12Z. THIS SOLUTION IS QUITE SIMILAR TO THE NEW 18Z
NAM. THESE SOLUTIONS CONTINUE TO TRANSPORT MOISTURE AROUND THE
CIRCULATION AND ACROSS WESTERN AND CENTRAL NEBRASKA THROUGH THE
OVERNIGHT HOURS. STRONG FRONTOGENESIS SETS UP ON THE BACK SIDE OF
THE SYSTEM...CENTERED OVER THE PANHANDLE AND WESTERN SANDHILLS
OVERNIGHT. WITH GOOD MOISTURE IN THAT AREA AND SUBSTANTIAL LIFT DUE
TO THE LARGE SCALE FORCING AND FRONTOGENESIS...EXPECT A GOOD
DEFORMATION BAND TO BE ONGOING THROUGH MUCH OF THE NIGHT. SOME AREAS
COULD SEE UP TO AN INCH OF MOISTURE BY 12Z MONDAY MORNING. THE BIG
QUESTION WITH THE PRECIPITATION IS IF ENOUGH COLD AIR WILL MOVE IN
TO GET SOME AREAS TO GET A CHANGEOVER TO SNOW. THE NAM AND THE RAP
BOTH SHOW WET BULB PROFILES BELOW ZERO UNTIL ABOUT 300FT OR LESS
ABOVE THE GROUND IN AREAS OVER THE NORTHEAST PANHANDLE...ESPECIALLY
THE PINE RIDGE. IF THIS TURNS OUT...MAY SEE LOTS OF SNOW FALLING BUT
WILL BE MELTING WHEN HITTING THE SURFACE OR JUST PRIOR. BUT...EVEN
ONE DEGREE DIFFERENCE WILL BE ALL THAT IS NEEDED TO CHANGE OVER
COMPLETELY TO SNOW AND IF RATES BECOME STRONG ENOUGH...COULD GET
DECENT ACCUMULATIONS. AT THIS TIME...WITH THE MODELS ALL KEEPING THE
WET BULB TEMPERATURE ABOVE 0C...DID PUT A COMPLETE CHANGEOVER TO
SNOW IN THE NORTHWEST ZONES...BUT ONLY HAVE ACCUMULATIONS UP TO 2
INCHES ASSUMING THERE WILL BE SUBSTANTIAL MELTING AT THE SURFACE.
THE NEXT QUESTION WILL BE WHAT WILL REMAIN FOR CONVECTION AND
THUNDERSTORM CHANCES OVERNIGHT. KEPT AT LEAST A MENTION OF ISOLATED
THUNDER IN AREAS ALONG THE INVERTED TROUGH GOING NORTH OF THE
SURFACE LOW AS MOISTURE AND SOME WEAK INSTABILITY WILL CONTINUE TO
CIRCULATE AROUND THE SYSTEM.
MOVING ON TO WINDS...A VERY TIGHT PRESSURE GRADIENT WILL BE SEEN ON
THE BACKSIDE OF THE SYSTEM...WHICH SHOULD CAUSE WINDS TO STRENGTHEN
ACROSS THE AREA AS THE LOW MOVES EAST TONIGHT. THE ONGOING WIND
ADVISORY FOR AREAS MAINLY WEST OF HIGHWAY 83 FOR THE OVERNIGHT
PERIODS CONTINUES TO LOOK GOOD AS SUSTAINED WINDS AROUND 30MPH STILL
LOOK LIKELY.
WITH THE POTENTIAL FOR MODERATE TO HEAVY SNOW AND STRONG WINDS OVER
THE NORTHEAST PART OF THE FORECAST AREA TONIGHT...DID CONSIDER A
NEED FOR A WINTER WEATHER ADVISORY FOR LATE TONIGHT INTO MONDAY
MORNING. AT THIS TIME...DUE TO THE UNCERTAINTY ON THE SWITCHOVER TO
SNOW...OPTED TO NOT ISSUE AT THIS TIME AND WILL MONITOR CLOSELY IF
HEADLINES ARE NEEDED.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 407 PM CDT SUN APR 27 2014
TOMORROW THROUGH WEDNESDAY...MAIN FORECAST CHALLENGES ARE WINDS AND
PRECIPITATION CHANCES IN ASSOCIATION WITH A SLOW MOVING UPPER LEVEL
LOW...WHICH WILL MIGRATE FROM EASTERN NEBRASKA INTO THE UPPER
MISSISSIPPI VALLEY OVER THE NEXT 24 TO 84 HOURS. IN ADDITION TO
PRECIPITATION CHANCES...THE THREAT FOR SNOW...PARTICULARLY DURING
THE NIGHTTIME HOURS...WILL BE A CONCERN ACROSS NORTHERN NEBRASKA
MONDAY NIGHT AND TUESDAY NIGHT.
FOR MONDAY...PRECIPITATION CHANCES AND WINDS WILL BE THE MAIN
FORECASTING CONCERN. ON MONDAY...THE MAIN UPPER LEVEL LOW WILL
MEANDER ACROSS CENTRAL NEBRASKA...DRIFTING INTO EASTERN NEBRASKA BY
LATE AFTERNOON. STRONG WINDS WILL DEVELOP ACROSS CENTRAL AND WESTERN
PORTIONS OF THE FORECAST AREA MONDAY AS H85 WINDS REACH 40 TO 50 KTS
IN THE SOUTHWEST AND SOUTHEASTERN PANHANDLE MONDAY AFTERNOON. WIND
SPEEDS DECREASE FAIRLY QUICKLY EAST OF THE HIGHWAY 83 CORRIDOR AND
DO NOT REALLY BEGIN TO KICK IN UNTIL MONDAY EVENING. TO AVOID
CONFUSION...DECIDED TO HOIST A HIGH WIND WATCH FOR LOCATIONS ROUGHLY
WEST OF A LINE FROM HAYES CENTER...TO ARTHUR...TO GARDEN COUNTY. IN
THESE AREAS...A WIND ADVISORY WILL LIKELY BE NEEDED TOMORROW...BUT
AT THIS TIME...I DO NOT HAVE ENOUGH CONFIDENCE TO ISSUE A HIGH WIND
WARNING AND WILL ISSUE A WATCH AND LET THE MIDNIGHT CREW MAKE THE
CALL. FURTHER EAST...TO THE HIGHWAY 83 CORRIDOR...NORTHERLY WINDS
WILL INCREASE BY MIDDAY AND ARE EXPECTED TO REACH ADVISORY
CRITERIA...FROM LINCOLN COUNTY NWD TO WESTERN CHERRY COUNTY AND WILL
HOIST A WIND ADVISORY FOR THESE AREAS. IN ADDITION TO WIND...THERE
IS STILL A SMALL THREAT FOR ACCUMULATING SNOWS MONDAY MORNING IN THE
FAR NORTHWESTERN FORECAST AREA IN THE VICINITY OF THE PINE RIDGE.
LIKE YESTERDAY...THE NAM HAS THE COLDEST BOUNDARY LAYER OF THE THREE
MID RANGE MODELS. GIVEN THE LACK OF COLD UPSTREAM AIR ACROSS NERN
WYOMING AND WESTERN SOUTH DAKOTA ATTM...AM INCLINED TO TREND TEMPS
TOWARD THE WARMER GFS AND ECMWF SOLNS. WITH THIS IN MIND...HAVE
WORDED THE FORECAST WITH A RAIN SNOW MIX THROUGH MID MORNING WITH
LITTLE OR NO SNOW ACCUMS EXPECTED. WILL CONTINUE TO MONITOR THIS
AREA CLOSELY. AS THE DAY PROGRESSES...WIDESPREAD RAIN WILL
CONTINUE...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE
FORECAST AREA...WHERE A STRONG MID LEVEL DEFORMATION ZONE WILL SET
UP AND PERSISTENT ISENTROPIC LIFT CONTINUES THROUGH THE AFTERNOON
HOURS.
ON MONDAY NIGHT...WINDS WILL INCREASE IN THE EAST AND SUBSIDE SOME
IN THE WEST AS THE UPPER LEVEL LOW MEANDERS INTO SWRN IOWA AND
NORTHWEST MISSOURI. WINDS WILL REMAIN ON THE GUSTY SIDE INTO THE
OVERNIGHT HOURS...WHICH MAY NECESSITATE ISSUANCE OF A WIND ADVISORY
MONDAY NIGHT. BASED ON THE LATEST MAV GUIDANCE AND BUFKIT
DATA...ALMOST THE ENTIRE FORECAST AREA MAY NEED A WIND ADVISORY FOR
MONDAY NIGHT. GIVEN THE ONGOING WIND HEADLINES...WILL HOLD OFF ON
ISSUANCE ATTM TO AVOID CONFUSION WITH OUR CURRENT HEADLINES. DECENT
ISENTROPIC LIFT CONTINUES INTO TUESDAY MORNING...ESPECIALLY OVER
CENTRAL AND NORTHERN NEBRASKA AND WILL CONTINUE LIKELY TO
CATEGORICAL POPS OVERNIGHT.
TUESDAY THROUGH WEDNESDAY...THE UPPER LEVEL LOW WILL MEANDER EAST ON
TUESDAY INTO WEDNESDAY...ENDING UP OVER THE WESTERN GREAT LAKES BY
THURSDAY MORNING. DURING THE PERIOD...THE THREAT FOR LIGHT RAIN WILL
CONTINUE TUESDAY WITH GUSTY WINDS EXPECTED AS WELL. H85 WINDS WILL
DECREASE TO 35 TO 45 KTS ON TUESDAY...SO ANOTHER MAY BE NEEDED FOR
TUESDAY ACROSS MOST OF THE FORECAST AREA. TEMPS WILL REMAIN COOL
HOWEVER WITH MOSTLY CLOUDY SKIES AND WITH H85 TEMPS RANGING FROM -2C
IN THE NORTHEAST...TO 3 C IN THE SOUTHWEST...HIGHS TUESDAY WILL
STRUGGLE TO GET OUT OF THE UPPER 30S TO 40S. ON WEDNESDAY...H85
TEMPS WILL WARM TO 1C IN THE NORTHEAST...TO 5C IN THE SOUTHWEST.
AFTERNOON HIGHS WILL REBOUND SLIGHTLY TO THE 40S TO LOWER 50S. WINDS
WILL BE SOMEWHAT LIGHTER...THOUGH WINDY WITH WIND SPEEDS OF 20 TO 30
MPH...WITH SOME HIGHER GUSTS TO 40 MPH. AT THIS TIME...AM NOT
ANTICIPATING ANY WIND HEADLINES ATTM.
WEDNESDAY NIGHT AND BEYOND...THE UPPER LEVEL LOW WILL BE ABSORBED
BY THE NORTHERN STREAM AND LIFTED EAST TOWARD THE END OF THE WEEK.
HOWEVER...LOW PRESSURE ALOFT WILL REMAIN ANCHORED OVER SOUTH CENTRAL
CANADA...AND WILL FORCE COLD AIR INTO THE NORTHERN PLAINS LATE IN
THE WEEK INTO THE WEEKEND. MAINLY DRY CONDITIONS ARE EXPECTED WITH
THIS FLOW REGIME. HIGHS WILL BE MORE MARCH LIKE WITH READINGS IN THE
50S EXPECTED FRIDAY...SATURDAY AND SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1141 PM CDT SUN APR 27 2014
WIDESPREAD MVFR/IFR IN RAIN AND SNOW IS EXPECTED TONIGHT THROUGH
MONDAY EVENING AS A SLOW MOVING STORM TRACKS THROUGH THE CENTRAL
PLAINS. WINDS 32035G45KT SHOULD REDEVELOP MONDAY MORNING AND SPREAD
FROM WEST TO EAST THROUGH MONDAY AFTN. WINDS SUBSIDE AROUND SUNSET.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM 7 AM CDT /6 AM MDT/ THIS MORNING TO 7 PM
CDT /6 PM MDT/ THIS EVENING FOR NEZ022-035-056>058-069-070.
WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ THIS MORNING FOR NEZ022-
035-056>058-069-070.
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR NEZ004-
023>025-036-037-059-071-094.
WINTER WEATHER ADVISORY UNTIL 7 AM MDT MONDAY FOR NEZ004-094.
WIND ADVISORY FROM 7 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR NEZ005-006-008-009-026-027-038.
&&
$$
UPDATE...POWER
SYNOPSIS...CLB
SHORT TERM...BROOKS
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1143 PM CDT SUN APR 27 2014
.SYNOPSIS...
ISSUED AT 407 PM CDT SUN APR 27 2014
A POTENT...UPPER LEVEL LOW WAS CENTERED OVER WESTERN KS
THIS AFTERNOON. A NICE JET STREAK EXTENDED FROM NORTHERN
CALIFORNIA...AROUND THE BASE OF THE LOW...NOSING INTO CENTRAL KS.
DOWNSTREAM OF THE TROUGH...A HIGH AMPLITUDE...NEGATIVE TILTED RIDGE
EXTENDED FROM THE SERN STATES INTO NRN MANITOBA. AT THE
SURFACE...LOW PRESSURE WAS NOTED OVER GOODLAND KS WITH A COLD FRONT
EXTENDING SSW INTO NERN NEW MEXICO. AN INVERTED TROUGH AXIS EXTENDED
NORTH OF THE LOW ALONG THE COLORADO/KS BORDER INTO THE NEBRASKA
PANHANDLE. WEST OF THIS INVERTED TROUGH...TEMPS WERE IN THE LOWER TO
MID 40S...WHILE EAST OF THE TROUGH AXIS...TEMPS WERE IN THE 60S AND
70S. A DRY LINE...EXTENDED NORTH OF THE SURFACE LOW INTO SWRN
NEBRASKA...WHERE IT TURNED SOUTHEAST INTO SOUTH CENTRAL NEBRASKA.
THUNDERSTORMS HAVE FIRED ALONG THE DRYLINE THIS AFTERNOON WITH THE
TORNADIC THREAT GENERALLY IN SOUTH CENTRAL NEBRASKA WHERE BETTER
DIRECTIONAL SHEAR EXISTS. FURTHER NORTH ACROSS THE CENTRAL AND
NORTHERN SANDHILLS...GOOD SPEED SHEAR EXISTS...HOWEVER DIRECTIONAL
SHEAR IS LACKING PER LATEST KLNX VAD WIND PROFILER. IN THESE
AREAS...STRONG TO SEVERE STORMS HAVE OCCURRED WITH LARGE HAIL BEING
THE MAIN SEVERE THREAT.
&&
.UPDATE...
ISSUED AT 1027 PM CDT SUN APR 27 2014
THE HIGH WIND WATCH HAS BEEN UPGRADED TO A HIGH WIND WARNING BASED
ON THE RAP AND 00Z NAM MODEL RUNS WHICH KEEP THE STRONGEST WINDS
ALONG HIGHWAY 61. THE AREA TO WATCH IS THE CENTRAL SANDHILLS WHERE
THE RAP AND NAM SHOW VERY STRONG 500M AGL WINDS APPROACHING 40 MPH
AT THE SFC MONDAY AFTERNOON.
NOTE THE FORECAST CONTINUES STRONG OR HIGH WINDS MONDAY NIGHT AND
TUESDAY WHICH WOULD NECESSITATE EXTENSIONS OF THE ON GOING HIGH
LIGHTS.
UPDATE ISSUED AT 837 PM CDT SUN APR 27 2014
A LOOK AT THE NEBRASKA DOR CAMS AND THE RAP MODEL SUGGEST WINTER
WEATHER ADVISORY CONDITIONS ACROSS SHERIDAN AND WESTERN CHERRY
COUNTIES. THE RAP INDICATES SEVERAL INCHES OF WET SNOW THIS
EVENING WHICH TAPERS OFF OR MIXES WITH RAIN AFTER MIDNIGHT. RADAR
INDICATES A DEFORMATION ZONE UNDERWAY ACROSS THIS AREA BUT MAINLY
ACROSS NRN SHERIDAN COUNTY. A WINTER ADVISORY IS IN PLACE FOR
THESE AREA AND IT OPERATES UNTIL 13Z.
THE FORECAST UPDATE FOLLOWS 50 PERCENT OF THE 23Z RAP AND 50
PERCENT OF THE PREVIOUS FORECAST. THE PTYPE USES THE RAP MODEL
WHICH SPREADS WET SNOW AS FAR SOUTH AS DEUEL COUNTY BUT LITTLE
ACCUMULATION IS EXPECTED THAT FAR SOUTH. IT LOOKS LIKE THE FAVORED
AREA FOR SNOW IS NORTHWEST NEBRASKA...NORTH OF THE NORTH PLATTE
VALLEY FOLLOWING THE H750 MB FRONT WHICH IS STRONGLY STACKED AND
MOVING VERY SLOWLY EAST TONIGHT. NOTE THE 23Z RAP PRODUCES OVER 1
INCH OF QPF ACROSS SHERIDAN COUNTY TONIGHT. THE FORECAST USES A
RATIO OF 6 TO 1 FOR 3 TO NEARLY 8 INCHES OF SNOW FAVORING PINE
RIDGE.
&&
.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 407 PM CDT SUN APR 27 2014
FORECAST CONCERNS CONTINUE WITH THUNDERSTORM CHANCES TONIGHT...THEN
LEAD TO FORMATION OF DEFORMATION BAND AND SNOW POTENTIAL.
THE UPPER LOW WAS CENTERED OVER NORTHWEST KANSAS AS OF 20Z...WITH
THE SURFACE CIRCULATION ALMOST DIRECTLY OVER KCBK.
WITH THE SYSTEM BEING NEARLY VERTICALLY STACKED OVER NORTHWEST
KANSAS THIS AFTERNOON...THERE IS CONCERN THAT THE MODELS MAY BE
TRYING TO KICK THE SYSTEM EAST TOO QUICKLY THIS EVENING AND
OVERNIGHT. THIS WILL IMPACT THE AREAS THAT CONTINUE TO SEE
CONVECTION...WHERE THE PRECIPITATION FALLS...WHERE THE WINDS
STRENGTHEN...AND WHERE AND WHEN THE RAIN SWITCHES OVER TO SNOW.
THE LATEST RAP MODEL MOVES THE SURFACE CIRCULATION TO NEAR KMCK BY
00Z THIS EVENING THEN OVER KHSI AT 06Z AND THEN MOVES IT UP TO
AROUND KBVN BY 12Z. THIS SOLUTION IS QUITE SIMILAR TO THE NEW 18Z
NAM. THESE SOLUTIONS CONTINUE TO TRANSPORT MOISTURE AROUND THE
CIRCULATION AND ACROSS WESTERN AND CENTRAL NEBRASKA THROUGH THE
OVERNIGHT HOURS. STRONG FRONTOGENESIS SETS UP ON THE BACK SIDE OF
THE SYSTEM...CENTERED OVER THE PANHANDLE AND WESTERN SANDHILLS
OVERNIGHT. WITH GOOD MOISTURE IN THAT AREA AND SUBSTANTIAL LIFT DUE
TO THE LARGE SCALE FORCING AND FRONTOGENESIS...EXPECT A GOOD
DEFORMATION BAND TO BE ONGOING THROUGH MUCH OF THE NIGHT. SOME AREAS
COULD SEE UP TO AN INCH OF MOISTURE BY 12Z MONDAY MORNING. THE BIG
QUESTION WITH THE PRECIPITATION IS IF ENOUGH COLD AIR WILL MOVE IN
TO GET SOME AREAS TO GET A CHANGEOVER TO SNOW. THE NAM AND THE RAP
BOTH SHOW WET BULB PROFILES BELOW ZERO UNTIL ABOUT 300FT OR LESS
ABOVE THE GROUND IN AREAS OVER THE NORTHEAST PANHANDLE...ESPECIALLY
THE PINE RIDGE. IF THIS TURNS OUT...MAY SEE LOTS OF SNOW FALLING BUT
WILL BE MELTING WHEN HITTING THE SURFACE OR JUST PRIOR. BUT...EVEN
ONE DEGREE DIFFERENCE WILL BE ALL THAT IS NEEDED TO CHANGE OVER
COMPLETELY TO SNOW AND IF RATES BECOME STRONG ENOUGH...COULD GET
DECENT ACCUMULATIONS. AT THIS TIME...WITH THE MODELS ALL KEEPING THE
WET BULB TEMPERATURE ABOVE 0C...DID PUT A COMPLETE CHANGEOVER TO
SNOW IN THE NORTHWEST ZONES...BUT ONLY HAVE ACCUMULATIONS UP TO 2
INCHES ASSUMING THERE WILL BE SUBSTANTIAL MELTING AT THE SURFACE.
THE NEXT QUESTION WILL BE WHAT WILL REMAIN FOR CONVECTION AND
THUNDERSTORM CHANCES OVERNIGHT. KEPT AT LEAST A MENTION OF ISOLATED
THUNDER IN AREAS ALONG THE INVERTED TROUGH GOING NORTH OF THE
SURFACE LOW AS MOISTURE AND SOME WEAK INSTABILITY WILL CONTINUE TO
CIRCULATE AROUND THE SYSTEM.
MOVING ON TO WINDS...A VERY TIGHT PRESSURE GRADIENT WILL BE SEEN ON
THE BACKSIDE OF THE SYSTEM...WHICH SHOULD CAUSE WINDS TO STRENGTHEN
ACROSS THE AREA AS THE LOW MOVES EAST TONIGHT. THE ONGOING WIND
ADVISORY FOR AREAS MAINLY WEST OF HIGHWAY 83 FOR THE OVERNIGHT
PERIODS CONTINUES TO LOOK GOOD AS SUSTAINED WINDS AROUND 30MPH STILL
LOOK LIKELY.
WITH THE POTENTIAL FOR MODERATE TO HEAVY SNOW AND STRONG WINDS OVER
THE NORTHEAST PART OF THE FORECAST AREA TONIGHT...DID CONSIDER A
NEED FOR A WINTER WEATHER ADVISORY FOR LATE TONIGHT INTO MONDAY
MORNING. AT THIS TIME...DUE TO THE UNCERTAINTY ON THE SWITCHOVER TO
SNOW...OPTED TO NOT ISSUE AT THIS TIME AND WILL MONITOR CLOSELY IF
HEADLINES ARE NEEDED.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 407 PM CDT SUN APR 27 2014
TOMORROW THROUGH WEDNESDAY...MAIN FORECAST CHALLENGES ARE WINDS AND
PRECIPITATION CHANCES IN ASSOCIATION WITH A SLOW MOVING UPPER LEVEL
LOW...WHICH WILL MIGRATE FROM EASTERN NEBRASKA INTO THE UPPER
MISSISSIPPI VALLEY OVER THE NEXT 24 TO 84 HOURS. IN ADDITION TO
PRECIPITATION CHANCES...THE THREAT FOR SNOW...PARTICULARLY DURING
THE NIGHTTIME HOURS...WILL BE A CONCERN ACROSS NORTHERN NEBRASKA
MONDAY NIGHT AND TUESDAY NIGHT.
FOR MONDAY...PRECIPITATION CHANCES AND WINDS WILL BE THE MAIN
FORECASTING CONCERN. ON MONDAY...THE MAIN UPPER LEVEL LOW WILL
MEANDER ACROSS CENTRAL NEBRASKA...DRIFTING INTO EASTERN NEBRASKA BY
LATE AFTERNOON. STRONG WINDS WILL DEVELOP ACROSS CENTRAL AND WESTERN
PORTIONS OF THE FORECAST AREA MONDAY AS H85 WINDS REACH 40 TO 50 KTS
IN THE SOUTHWEST AND SOUTHEASTERN PANHANDLE MONDAY AFTERNOON. WIND
SPEEDS DECREASE FAIRLY QUICKLY EAST OF THE HIGHWAY 83 CORRIDOR AND
DO NOT REALLY BEGIN TO KICK IN UNTIL MONDAY EVENING. TO AVOID
CONFUSION...DECIDED TO HOIST A HIGH WIND WATCH FOR LOCATIONS ROUGHLY
WEST OF A LINE FROM HAYES CENTER...TO ARTHUR...TO GARDEN COUNTY. IN
THESE AREAS...A WIND ADVISORY WILL LIKELY BE NEEDED TOMORROW...BUT
AT THIS TIME...I DO NOT HAVE ENOUGH CONFIDENCE TO ISSUE A HIGH WIND
WARNING AND WILL ISSUE A WATCH AND LET THE MIDNIGHT CREW MAKE THE
CALL. FURTHER EAST...TO THE HIGHWAY 83 CORRIDOR...NORTHERLY WINDS
WILL INCREASE BY MIDDAY AND ARE EXPECTED TO REACH ADVISORY
CRITERIA...FROM LINCOLN COUNTY NWD TO WESTERN CHERRY COUNTY AND WILL
HOIST A WIND ADVISORY FOR THESE AREAS. IN ADDITION TO WIND...THERE
IS STILL A SMALL THREAT FOR ACCUMULATING SNOWS MONDAY MORNING IN THE
FAR NORTHWESTERN FORECAST AREA IN THE VICINITY OF THE PINE RIDGE.
LIKE YESTERDAY...THE NAM HAS THE COLDEST BOUNDARY LAYER OF THE THREE
MID RANGE MODELS. GIVEN THE LACK OF COLD UPSTREAM AIR ACROSS NERN
WYOMING AND WESTERN SOUTH DAKOTA ATTM...AM INCLINED TO TREND TEMPS
TOWARD THE WARMER GFS AND ECMWF SOLNS. WITH THIS IN MIND...HAVE
WORDED THE FORECAST WITH A RAIN SNOW MIX THROUGH MID MORNING WITH
LITTLE OR NO SNOW ACCUMS EXPECTED. WILL CONTINUE TO MONITOR THIS
AREA CLOSELY. AS THE DAY PROGRESSES...WIDESPREAD RAIN WILL
CONTINUE...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE
FORECAST AREA...WHERE A STRONG MID LEVEL DEFORMATION ZONE WILL SET
UP AND PERSISTENT ISENTROPIC LIFT CONTINUES THROUGH THE AFTERNOON
HOURS.
ON MONDAY NIGHT...WINDS WILL INCREASE IN THE EAST AND SUBSIDE SOME
IN THE WEST AS THE UPPER LEVEL LOW MEANDERS INTO SWRN IOWA AND
NORTHWEST MISSOURI. WINDS WILL REMAIN ON THE GUSTY SIDE INTO THE
OVERNIGHT HOURS...WHICH MAY NECESSITATE ISSUANCE OF A WIND ADVISORY
MONDAY NIGHT. BASED ON THE LATEST MAV GUIDANCE AND BUFKIT
DATA...ALMOST THE ENTIRE FORECAST AREA MAY NEED A WIND ADVISORY FOR
MONDAY NIGHT. GIVEN THE ONGOING WIND HEADLINES...WILL HOLD OFF ON
ISSUANCE ATTM TO AVOID CONFUSION WITH OUR CURRENT HEADLINES. DECENT
ISENTROPIC LIFT CONTINUES INTO TUESDAY MORNING...ESPECIALLY OVER
CENTRAL AND NORTHERN NEBRASKA AND WILL CONTINUE LIKELY TO
CATEGORICAL POPS OVERNIGHT.
TUESDAY THROUGH WEDNESDAY...THE UPPER LEVEL LOW WILL MEANDER EAST ON
TUESDAY INTO WEDNESDAY...ENDING UP OVER THE WESTERN GREAT LAKES BY
THURSDAY MORNING. DURING THE PERIOD...THE THREAT FOR LIGHT RAIN WILL
CONTINUE TUESDAY WITH GUSTY WINDS EXPECTED AS WELL. H85 WINDS WILL
DECREASE TO 35 TO 45 KTS ON TUESDAY...SO ANOTHER MAY BE NEEDED FOR
TUESDAY ACROSS MOST OF THE FORECAST AREA. TEMPS WILL REMAIN COOL
HOWEVER WITH MOSTLY CLOUDY SKIES AND WITH H85 TEMPS RANGING FROM -2C
IN THE NORTHEAST...TO 3 C IN THE SOUTHWEST...HIGHS TUESDAY WILL
STRUGGLE TO GET OUT OF THE UPPER 30S TO 40S. ON WEDNESDAY...H85
TEMPS WILL WARM TO 1C IN THE NORTHEAST...TO 5C IN THE SOUTHWEST.
AFTERNOON HIGHS WILL REBOUND SLIGHTLY TO THE 40S TO LOWER 50S. WINDS
WILL BE SOMEWHAT LIGHTER...THOUGH WINDY WITH WIND SPEEDS OF 20 TO 30
MPH...WITH SOME HIGHER GUSTS TO 40 MPH. AT THIS TIME...AM NOT
ANTICIPATING ANY WIND HEADLINES ATTM.
WEDNESDAY NIGHT AND BEYOND...THE UPPER LEVEL LOW WILL BE ABSORBED
BY THE NORTHERN STREAM AND LIFTED EAST TOWARD THE END OF THE WEEK.
HOWEVER...LOW PRESSURE ALOFT WILL REMAIN ANCHORED OVER SOUTH CENTRAL
CANADA...AND WILL FORCE COLD AIR INTO THE NORTHERN PLAINS LATE IN
THE WEEK INTO THE WEEKEND. MAINLY DRY CONDITIONS ARE EXPECTED WITH
THIS FLOW REGIME. HIGHS WILL BE MORE MARCH LIKE WITH READINGS IN THE
50S EXPECTED FRIDAY...SATURDAY AND SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1141 PM CDT SUN APR 27 2014
WIDESPREAD MVFR/IFR IN RAIN AND SNOW IS EXPECTED TONIGHT THROUGH
MONDAY EVENING AS A SLOW MOVING STORM TRACKS THROUGH THE CENTRAL
PLAINS. WINDS 32035G45KT SHOULD REDEVELOP MONDAY MORNING AND SPREAD
FROM WEST TO EAST THROUGH MONDAY AFTN. WINDS SUBSIDE AROUND SUNSET.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM 7 AM CDT /6 AM MDT/ TO 7 PM CDT /6 PM
MDT/ MONDAY FOR NEZ022-035-056>058-069-070.
WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR NEZ022-035-
056>058-069-070.
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ MONDAY FOR NEZ004-
023>025-036-037-059-071-094.
WINTER WEATHER ADVISORY UNTIL 7 AM MDT MONDAY FOR NEZ004-094.
WIND ADVISORY FROM 7 AM TO 7 PM CDT MONDAY FOR NEZ005-006-008-
009-026-027-038.
&&
$$
UPDATE...CDC
SYNOPSIS...CLB
SHORT TERM...BROOKS
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1030 PM EDT TUE APR 29 2014
.SYNOPSIS...
SHOWERS AND PERIODS OF LIGHT RAIN FROM THE CHAMPLAIN VALLEY
WESTWARD TONIGHT...WILL SPREAD ACROSS THE ENTIRE REGION DURING
WEDNESDAY AND BECOME HEAVY AT TIMES WEDNESDAY NIGHT BEFORE
TAPERING TO SHOWERS BY THURSDAY. WITH THE CLOUDS AND RAINFALL ON
WEDNESDAY...TEMPERATURES WILL BE QUITE CHILLY...THOUGH MILD
READINGS SHOULD RETURN BY THURSDAY. UPPER LEVEL LOW PRESSURE WILL
THEN SETTLE ACROSS THE REGION FOR FRIDAY INTO THE UPCOMING WEEKEND
KEEPING PLENTY OF CLOUDS AND SCATTERED SHOWERS IN THE FORECAST
AS TEMPERATURES ONCE AGAIN TREND SEASONABLY COOL.
&&
.NEAR TERM /UNTIL 7 AM WEDNESDAY MORNING/...
AS OF 1030 PM EDT TUESDAY...MINOR TWEAKS TO POPS/TEMPS AS WE
PROGRESS INTO THE LATE EVENING HOURS. MAINLY NOISE-LEVEL
ADJUSTMENTS HOWEVER AND BY LARGE CURRENT FORECAST REMAINS
UNCHANGED. HAVE A GREAT NIGHT. PRIOR DISCUSSION BELOW...
PRIOR DISCUSSION...
MINOR ADJUSTMENTS TO TEMPS WX AND POPS AS OF 730 PM...MAINLY TO
BRING PERIODS OF SPRINKLES OR VERY LIGHT RAIN INTO THE CHAMPLAIN
VALLEY THIS EVENING/TONIGHT. THIS IS JUST A TAD EAST OF EARLIER
FORECAST...BUT RECENT VWP PROFILES FROM TYX SUGGEST ENOUGH
SOUTHWEST FLOW AT 500 MB TO PUSH CURRENT BAND OF LIGHT RAIN ACROSS
CENTRAL/NRN NEW YORK EASTWARD INTO THE CHAMPLAIN VALLEY THIS
EVENING/TONIGHT. 22Z RAP AND MOST RECENT SREF SIMULATED RADAR
PROGS HANDLING CURRENT EVOLUTION OF BAND MOST CLOSELY AND WILL
LEAN IN THEIR DIRECTION ACCORDINGLY. PCPN TO RANGE FROM A FEW
TENTHS ACROSS NORTHERN NEW YORK TONIGHT WHERE STEADIEST ACTIVITY
WILL OCCUR...MUCH LIGHTER (JUST A FEW HUNDREDTHS) INTO THE
CHAMPLAIN VALLEY WHERE MANY SPOTS MAY JUST TRACE. MAINLY DRY
CONDITIONS SHOULD PREVAIL ACROSS MOST OF EAST CENTRAL AND
NORTHEAST VT. ONLY OTHER CHANGE WAS TO RAISE TEMPERATURES BY ABOUT
3 DEGREES BASED OFF LATEST WET BULB COOLING TRENDS AS SFC
DEWPOINTS HAVE ALRADY RISEN ABOVE ADVERTISED MINIMUMS. REST OF
FORECAST REMAINS IN GREAT SHAPE ADVERTISING PLENTY OF CLOUDS AND
MODEST TO OCCASIONALLY GUSTY EAST TO SOUTHEASTERLY WINDS AS P-GRAD
SLOWLY TIGHTENS OVERNIGHT.
&&
.SHORT TERM /7 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 320 PM EDT TUESDAY...THE NORTH COUNTRY WILL REMAIN IN
STRONG DEFORMATION ZONE BETWEEN STRONG DEEP-LAYER SWLY FLOW EAST
OF PARENT UPR LOW OVER THE GREAT LAKES...AND BUILDING DOWNSTREAM
RIDGE ACROSS THE GULF OF MAINE. THIS PATTERN WILL RETARD EWD
MOTION OF RAINFALL INTO VERMONT...BUT ULTIMATELY INCREASED
MOISTURE ADVECTION AND UVV WILL SHIFT FROM NRN NY WEDNESDAY
MORNING ACROSS VT DURING THE AFTN HRS. SELY WINDS WILL REMAIN
GUSTY AT 15-25 MPH. IT WILL BE QUITE A RAW DAY DUE TO PROLONGED
ONSHORE FLOW REACHING ERN VT. IN THE CT RIVER VALLEY...TEMPS WILL
HOVER IN THE LOWER 40S WITH OVERCAST SKIES. HIGHS ACROSS THE
CHAMPLAIN VALLEY AND NRN NY WILL GENERALLY BE IN THE 45-50F RANGE
WITH PERIODS OF RAIN (POPS REACH 80-100% BY AFTN).
PRIMARY PW PLUME (1.3-1.4") TRANSLATES ENEWD ACROSS THE NORTH
COUNTRY DURING WEDNESDAY NIGHT. WHILE PW VALUES AREN`T
EXTREME...THE WIDTH OF THE PW PLUME IS QUITE WIDE...A RESULT OF
THE SLOW MOVEMENT OF THE PARENT LOW AND PROLONGED NORTHEASTWARD
MOISTURE ADVECTION FROM THE GULF OF MEXICO. PRONOUNCED
DEFORMATION/FRONTOGENETIC BAND ALSO ACCOMPANIES THE PW
PLUME...ASSOCIATED WITH CONTINUED SPEED CONVERGENCE NEAR THE
700MB INFLECTION BETWEEN THE UPSTREAM LOW AND DEPARTING RIDGE
AXIS. HAVE INCLUDED SOME HEAVY RAIN WORDING IN THE FORECAST FOR
WEDNESDAY NIGHT...WITH QPF AMTS UP TO 0.50" POSSIBLE. TOTAL
RAINFALL WILL RANGE FROM 0.75-1" ACROSS NRN VT...LIMITED SOMEWHAT
BY DOWNSLOPING EFFECTS IN THE CHAMPLAIN VALLEY AND FAR NERN VT
(DOWNSLOPE OFF THE WHITE MTNS). HIGHER AMTS OF STORM TOTAL
RAINFALL ACROSS NRN NY (1.00-1.50") AND ALSO ALONG THE ERN SLOPES
OF THE SRN GREEN MTNS (1.00-1.25") ASSOCIATED WITH LOW-LEVEL
UPSLOPE CONDITIONS.
HYDROLOGICALLY...RIVERS HAVE RECEDED TO NEAR BASE LEVELS BUT WILL
NEED TO MONITOR AUSABLE FORKS AND OTTER CREEK AT CENTER RUTLAND
IF RAINFALL EXCEEDS CURRENT EXPECTATIONS. BASED ON CURRENT
FORECAST...ALL RIVERS WILL REMAIN WITHIN BANKFULL. LAKE CHAMPLAIN
REMAINS VERY CLOSE TO FLOOD STAGE. IT MAY BRIEFLY DROP BELOW
FLOOD STAGE WEDNESDAY BEFORE RAINFALL RUNOFF RESULTS IN A RENEWED
MINOR RISE. WE WILL CONTINUE TO MONITOR.
FORECAST AREA BREAKS INTO THE WARM SECTOR BRIEFLY THURSDAY WITH
POTENTIAL FOR ISOLD/SCT SHOWERS AND ONE DAY OF WARM TEMPS. THE
12Z GFS INDICATES THAT 850MB TEMPERATURES WILL BRIEFLY REACH +9
TO +10C...SO EVEN PARTIAL SUNSHINE WILL RESULT IN TEMPERATURES
INTO THE UPR 60S...AND POSSIBLY LOWER 70S. HAVE ADJUSTED THE
FORECAST UP A FEW DEGREES FROM MODEL CONSENSUS.
BROAD CYCLONIC 700-500MB FLOW REGIME IN PLACE THURSDAY NIGHT. IT
APPEARS SKIES WILL REMAIN MOSTLY CLOUDY...AND MAY SEE SOME LIGHT
RAIN SHOWER ACTIVITY...MAINLY ACROSS THE HIR TRRN. LOWS GENERALLY
40-45F THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 345 PM EDT TUESDAY...BROAD AREA OF LOW PRESSURE WILL BE
CENTERED OVER HUDSON BAY ON FRIDAY MORNING...WITH SEVERAL LOW
CENTERS ROTATING AROUND. UPPER LEVEL TROF WILL ALSO BE SITUATED
OVER THE GREAT LAKES REGION. THESE TWO FEATURES TOGETHER WILL
MEANDER OVER THE AREA FROM FRIDAY THROUGH EARLY SUNDAY. LOW
PRESSURE SYSTEM WILL THEN BREAK OFF FROM BROAD ROTATION AND DROP
SOUTHEASTWARD ACROSS NEW ENGLAND FROM SUNDAY THROUGH MONDAY.
SURFACE HIGH WILL FINALLY RIDGE OVER THE AREA MONDAY NIGHT AND
TUESDAY. EXTENDED PORTION OF THE FORECAST WILL FEATURE SEVERAL
ROUNDS OF PRECIPITATION AS SHORTWAVE ENERGY ROTATES AROUND UPPER
LEVEL TROF...AND THEN AS SURFACE LOW CROSSES NEW ENGLAND. THERE
WILL BE A GENERAL DRYING TREND TOWARDS THE BEGINNING OF NEXT
WEEK. MAXIMUM TEMPERATURES WILL RUN BELOW SEASONAL NORMALS
THROUGH THE PERIOD WITH CLOUDS AND PRECIP AFFECTING THE NORTH
COUNTRY. OVERNIGHT MIN TEMPS WILL BE NEAR TO SLIGHTLY ABOVE
NORMAL...ALSO DUE TO CLOUDS AND PRECIP.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 00Z THURSDAY...PERIODS OF LIGHT RAIN FROM THE CHAMPLAIN
VALLEY WESTWARD TONIGHT...STEADIEST AT NRN NY TERMINALS OF
KMSS/KSLK. MAINLY DRY AT KMPV...THOUGH SOME BRIEF LIGHT RAIN
AND/OR SPRINKLES POSSIBLE. CIGS MAINLY VFR. WINDS EAST TO
SOUTHEASTERLY 10 TO 20 KTS AND OCCASIONALLY GUSTY...ESP AT KRUT
WHERE GUSTS TO 35 KTS POSSIBLE. AFTER 12Z...WIDESPREAD AND STEADY
RAIN SPREADS EASTWARD ACROSS ALL TERMINALS AND MAY TREND MODERATE
TO HEAVY LATE IN THE FORECAST CYCLE AS CIGS LOWER TO MVFR/IFR.
MODEST EAST TO SOUTHEASTERLY FLOW CONTINUES...OCCASIONALLY GUSTY
AT TIMES...ESP AT KRUT AND CHAMPLAIN VALLEY TERMINALS WHERE SOME
INTERLUDES OF VFR MAY OCCUR DUE TO DOWNSLOPING EFFECTS.
OUTLOOK 00Z THURSDAY THROUGH SUNDAY...
00Z THU THRU 18Z THU...MVFR WITH OCCASIONAL IFR IN RAIN...TAPERING
TO SCATTERED SHOWERS
18Z THU THRU SUN...BKN/OVC VFR WITH OCCNL MVFR IN SCATTERED SHOWERS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...BANACOS
LONG TERM...NEILES
AVIATION...JMG/NEILES
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
800 PM EDT TUE APR 29 2014
.SYNOPSIS...
SHOWERS AND PERIODS OF LIGHT RAIN FROM THE CHAMPLAIN VALLEY
WESTWARD TONIGHT...WILL SPREAD ACROSS THE ENTIRE REGION DURING
WEDNESDAY AND BECOME HEAVY AT TIMES WEDNESDAY NIGHT BEFORE
TAPERING TO SHOWERS BY THURSDAY. WITH THE CLOUDS AND RAINFALL ON
WEDNESDAY...TEMPERATURES WILL BE QUITE CHILLY...THOUGH MILD
READINGS SHOULD RETURN BY THURSDAY. UPPER LEVEL LOW PRESSURE WILL
THEN SETTLE ACROSS THE REGION FOR FRIDAY INTO THE UPCOMING WEEKEND
...KEEPING PLENTY OF CLOUDS AND SCATTERED SHOWERS IN THE FORECAST
AS TEMPERATURES ONCE AGAIN TREND SEASONABLY COOL.
&&
.NEAR TERM /UNTIL 7 AM WEDNESDAY MORNING/...
AS OF 800 PM EDT TUESDAY...MINOR ADJUSTMENTS TO TEMPS WX AND POPS AS
OF 730 PM...MAINLY TO BRING PERIODS OF SPRINKLES OR VERY LIGHT RAIN
INTO THE CHAMPLAIN VALLEY THIS EVENING/TONIGHT. THIS IS JUST A TAD
EAST OF EARLIER FORECAST...BUT RECENT VWP PROFILES FROM TYX
SUGGEST ENOUGH SOUTHWEST FLOW AT 500 MB TO PUSH CURRENT BAND OF
LIGHT RAIN ACROSS CENTRAL/NRN NEW YORK EASTWARD INTO THE CHAMPLAIN
VALLEY THIS EVENING/TONIGHT. 22Z RAP AND MOST RECENT SREF
SIMULATED RADAR PROGS HANDLING CURRENT EVOLUTION OF BAND MOST
CLOSELY AND WILL LEAN IN THEIR DIRECTION ACCORDINGLY. PCPN TO
RANGE FROM A FEW TENTHS ACROSS NORTHERN NEW YORK TONIGHT WHERE
STEADIEST ACTIVITY WILL OCCUR...MUCH LIGHTER (JUST A FEW
HUNDREDTHS) INTO THE CHAMPLAIN VALLEY WHERE MANY SPOTS MAY JUST
TRACE. MAINLY DRY CONDITIONS SHOULD PREVAIL ACROSS MOST OF EAST
CENTRAL AND NORTHEAST VT. ONLY OTHER CHANGE WAS TO RAISE
TEMPERATURES BY ABOUT 3 DEGREES BASED OFF LATEST WET BULB COOLING
TRENDS AS SFC DEWPOINTS HAVE ALRADY RISEN ABOVE ADVERTISED
MINIMUMS. REST OF FORECAST REMAINS IN GREAT SHAPE ADVERTISING
PLENTY OF CLOUDS AND MODEST TO OCCASIONALLY GUSTY EAST TO
SOUTHEASTERLY WINDS AS P-GRAD SLOWLY TIGHTENS OVERNIGHT. ENJOY
YOUR EVENING. PRIOR DISCUSSION FOLLOWS.
PRIOR DISCUSSION...
PRONOUNCED 925-850MB WAA AND SPEED CONVERGENCE EVIDENT IN REGIONAL
VAD WIND PROFILES BETWEEN CXX AND TYX/BUF...WITH 850MB WINDS
RANGING FROM 25KTS AT CXX TO 51KT AT TYX AND 56KTS AT KBUF. THIS
IS LEADING TO STRONG DEFORMATION FORCING AND UVV ASSOCIATED WITH
WIDESPREAD RAINFALL EVIDENT ON MOSAIC RADAR IMAGERY ACROSS CENTRAL
NY WNWWD ACROSS LAKE ONTARIO THIS AFTN. THIS BROAD BAND OF
RAINFALL WILL MOVE NEWD INTO OUR NRN NY ZONES THIS EVENING...WITH
INCREASING MID-LEVEL CLOUD COVER ACROSS VT. OWING TO THE STRONG
DEEP-LAYER RIDGE ANCHORED ACROSS ERN NEW ENGLAND...IT APPEARS
UNLIKELY THAT RAINFALL WILL MOVES INTO VERMONT TONIGHT. THE 12Z
GFS SEEMS TO HAVE THIS IDEA WITH LEADING RAIN BAND BECOMING QUASI-
STATIONARY WHILE WEAKENING ACROSS NRN NY OVERNIGHT. HAVE SHOWN A
STRONG E-W GRADIENT IN POPS AS A RESULT...WITH JUST 20 PERCENT IN
THE CHAMPLAIN VALLEY AND LESSER POPS TO THE EAST. IN TERMS OF
RAINFALL AMTS OVERNIGHT LOOKING AT 0.2-0.3" ACROSS NRN NY AND
GENERALLY DRY ACROSS VERMONT.
RECYCLED LOW-LEVEL MARITIME MODIFIED AIRMASS CONTINUES TO ADVECT
IN ON GUSTY ESE-SE LOW-LEVEL FLOW INTO CENTRAL AND ERN VT AS
WELL. ANTICIPATE SOME WINDS 15-25 MPH CONTINUING THROUGH
TONIGHT...AND MAY SEE SOME LOCALIZED GAP WINDS UP TO 35 MPH
THROUGH THE GREEN MTN PASSES AS COOLER MARINE AIR WORKS WWD ALONG
THE GREEN MTN SPINE OVERNIGHT. WITH THE AFOREMENTIONED WINDS AND
INCREASING CLOUDS...OVERNIGHT LOW TEMPERATURES WILL BE RELATIVELY
UNIFORM ACROSS THE FORECAST AREA. VALUES WILL RANGE FROM THE UPR
30S ACROSS CENTRAL/ERN VT AND IN THE LOWER 40S FROM THE CHAMPLAIN
VALLEY AND POINTS WWD.
&&
.SHORT TERM /7 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 320 PM EDT TUESDAY...THE NORTH COUNTRY WILL REMAIN IN
STRONG DEFORMATION ZONE BETWEEN STRONG DEEP-LAYER SWLY FLOW EAST
OF PARENT UPR LOW OVER THE GREAT LAKES...AND BUILDING DOWNSTREAM
RIDGE ACROSS THE GULF OF MAINE. THIS PATTERN WILL RETARD EWD
MOTION OF RAINFALL INTO VERMONT...BUT ULTIMATELY INCREASED
MOISTURE ADVECTION AND UVV WILL SHIFT FROM NRN NY WEDNESDAY
MORNING ACROSS VT DURING THE AFTN HRS. SELY WINDS WILL REMAIN
GUSTY AT 15-25 MPH. IT WILL BE QUITE A RAW DAY DUE TO PROLONGED
ONSHORE FLOW REACHING ERN VT. IN THE CT RIVER VALLEY...TEMPS WILL
HOVER IN THE LOWER 40S WITH OVERCAST SKIES. HIGHS ACROSS THE
CHAMPLAIN VALLEY AND NRN NY WILL GENERALLY BE IN THE 45-50F RANGE
WITH PERIODS OF RAIN (POPS REACH 80-100% BY AFTN).
PRIMARY PW PLUME (1.3-1.4") TRANSLATES ENEWD ACROSS THE NORTH
COUNTRY DURING WEDNESDAY NIGHT. WHILE PW VALUES AREN`T
EXTREME...THE WIDTH OF THE PW PLUME IS QUITE WIDE...A RESULT OF
THE SLOW MOVEMENT OF THE PARENT LOW AND PROLONGED NORTHEASTWARD
MOISTURE ADVECTION FROM THE GULF OF MEXICO. PRONOUNCED
DEFORMATION/FRONTOGENETIC BAND ALSO ACCOMPANIES THE PW
PLUME...ASSOCIATED WITH CONTINUED SPEED CONVERGENCE NEAR THE
700MB INFLECTION BETWEEN THE UPSTREAM LOW AND DEPARTING RIDGE
AXIS. HAVE INCLUDED SOME HEAVY RAIN WORDING IN THE FORECAST FOR
WEDNESDAY NIGHT...WITH QPF AMTS UP TO 0.50" POSSIBLE. TOTAL
RAINFALL WILL RANGE FROM 0.75-1" ACROSS NRN VT...LIMITED SOMEWHAT
BY DOWNSLOPING EFFECTS IN THE CHAMPLAIN VALLEY AND FAR NERN VT
(DOWNSLOPE OFF THE WHITE MTNS). HIGHER AMTS OF STORM TOTAL
RAINFALL ACROSS NRN NY (1.00-1.50") AND ALSO ALONG THE ERN SLOPES
OF THE SRN GREEN MTNS (1.00-1.25") ASSOCIATED WITH LOW-LEVEL
UPSLOPE CONDITIONS.
HYDROLOGICALLY...RIVERS HAVE RECEDED TO NEAR BASE LEVELS BUT WILL
NEED TO MONITOR AUSABLE FORKS AND OTTER CREEK AT CENTER RUTLAND
IF RAINFALL EXCEEDS CURRENT EXPECTATIONS. BASED ON CURRENT
FORECAST...ALL RIVERS WILL REMAIN WITHIN BANKFULL. LAKE CHAMPLAIN
REMAINS VERY CLOSE TO FLOOD STAGE. IT MAY BRIEFLY DROP BELOW
FLOOD STAGE WEDNESDAY BEFORE RAINFALL RUNOFF RESULTS IN A RENEWED
MINOR RISE. WE WILL CONTINUE TO MONITOR.
FORECAST AREA BREAKS INTO THE WARM SECTOR BRIEFLY THURSDAY WITH
POTENTIAL FOR ISOLD/SCT SHOWERS AND ONE DAY OF WARM TEMPS. THE
12Z GFS INDICATES THAT 850MB TEMPERATURES WILL BRIEFLY REACH +9
TO +10C...SO EVEN PARTIAL SUNSHINE WILL RESULT IN TEMPERATURES
INTO THE UPR 60S...AND POSSIBLY LOWER 70S. HAVE ADJUSTED THE
FORECAST UP A FEW DEGREES FROM MODEL CONSENSUS.
BROAD CYCLONIC 700-500MB FLOW REGIME IN PLACE THURSDAY NIGHT. IT
APPEARS SKIES WILL REMAIN MOSTLY CLOUDY...AND MAY SEE SOME LIGHT
RAIN SHOWER ACTIVITY...MAINLY ACROSS THE HIR TRRN. LOWS GENERALLY
40-45F THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 345 PM EDT TUESDAY...BROAD AREA OF LOW PRESSURE WILL BE
CENTERED OVER HUDSON BAY ON FRIDAY MORNING...WITH SEVERAL LOW
CENTERS ROTATING AROUND. UPPER LEVEL TROF WILL ALSO BE SITUATED
OVER THE GREAT LAKES REGION. THESE TWO FEATURES TOGETHER WILL
MEANDER OVER THE AREA FROM FRIDAY THROUGH EARLY SUNDAY. LOW
PRESSURE SYSTEM WILL THEN BREAK OFF FROM BROAD ROTATION AND DROP
SOUTHEASTWARD ACROSS NEW ENGLAND FROM SUNDAY THROUGH MONDAY.
SURFACE HIGH WILL FINALLY RIDGE OVER THE AREA MONDAY NIGHT AND
TUESDAY. EXTENDED PORTION OF THE FORECAST WILL FEATURE SEVERAL
ROUNDS OF PRECIPITATION AS SHORTWAVE ENERGY ROTATES AROUND UPPER
LEVEL TROF...AND THEN AS SURFACE LOW CROSSES NEW ENGLAND. THERE
WILL BE A GENERAL DRYING TREND TOWARDS THE BEGINNING OF NEXT
WEEK. MAXIMUM TEMPERATURES WILL RUN BELOW SEASONAL NORMALS
THROUGH THE PERIOD WITH CLOUDS AND PRECIP AFFECTING THE NORTH
COUNTRY. OVERNIGHT MIN TEMPS WILL BE NEAR TO SLIGHTLY ABOVE
NORMAL...ALSO DUE TO CLOUDS AND PRECIP.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 00Z THURSDAY...PERIODS OF LIGHT RAIN FROM THE CHAMPLAIN
VALLEY WESTWARD TONIGHT...STEADIEST AT NRN NY TERMINALS OF
KMSS/KSLK. MAINLY DRY AT KMPV...THOUGH SOME BRIEF LIGHT RAIN
AND/OR SPRINKLES POSSIBLE. CIGS MAINLY VFR. WINDS EAST TO
SOUTHEASTERLY 10 TO 20 KTS AND OCCASIONALLY GUSTY...ESP AT KRUT
WHERE GUSTS TO 35 KTS POSSIBLE. AFTER 12Z...WIDESPREAD AND STEADY
RAIN SPREADS EASTWARD ACROSS ALL TERMINALS AND MAY TREND MODERATE
TO HEAVY LATE IN THE FORECAST CYCLE AS CIGS LOWER TO MVFR/IFR.
MODEST EAST TO SOUTHEASTERLY FLOW CONTINUES...OCCASIONALLY GUSTY
AT TIMES...ESP AT KRUT AND CHAMPLAIN VALLEY TERMINALS WHERE SOME
INTERLUDES OF VFR MAY OCCUR DUE TO DOWNSLOPING EFFECTS.
OUTLOOK 00Z THURSDAY THROUGH SUNDAY...
00Z THU THRU 18Z THU...MVFR WITH OCCASIONAL IFR IN RAIN...TAPERING
TO SCATTERED SHOWERS
18Z THU THRU SUN...BKN/OVC VFR WITH OCCNL MVFR IN SCATTERED SHOWERS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/BANACOS
SHORT TERM...BANACOS
LONG TERM...NEILES
AVIATION...JMG/NEILES
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1037 PM EDT TUE APR 29 2014
.SYNOPSIS...
A COLD FRONT ACROSS WESTERN TENNESSEE AND MISSISSIPPI WILL MOVE
ACROSS THE EASTERN CAROLINAS THURSDAY NIGHT. WAVES OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED...WITH A GROWING RISK OF SEVERE WEATHER
WEDNESDAY. HIGH PRESSURE WILL BRING DRY WEATHER FOR THE WEEKEND...
ALTHOUGH A FRONT MAY APPROACH THE AREA FROM THE NORTH EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM TUESDAY...ASIDE FROM A THIN LINE OF SHOWERS ACROSS
WHITEVILLE AND ELIZABETHTOWN PRECIPITATION HAS ENDED ACROSS OUR
PORTION OF THE CAROLINAS. THE WARM FRONT ACROSS EASTERN NORTH
CAROLINA IS DRIFTING NORTHWARD AND WE SHOULD SEE OUR SOUTH-SOUTHEAST
WINDS VEER MORE SOUTHERLY WITH TIME. LATEST HRRR MODELS SHOW
REDEVELOPMENT OF SCATTERED SHOWERS LATE TONIGHT...AND I WILL
MAINTAIN SMALL POPS IN THE FORECAST FOR THIS POTENTIAL. NO OTHER
SIGNIFICANT CHANGES ARE NEEDED. PREVIOUS DISCUSSION FROM 730 PM
FOLLOWS...
A NEARLY STATIONARY FRONT ACROSS EAST-CENTRAL NORTH CAROLINA HAS
BEEN THE FOCUS FOR SEVERE WEATHER THIS AFTERNOON...MAINLY TAKING THE
FORM OF LARGE HAIL AND TORNADOES. CAPE EARLIER EXCEEDED 3000 J/KG
BUT IS FALLING NOW THAT SURFACE TEMPERATURES ARE COOLING. SEVERE
WEATHER HAS LARGELY STEERED NORTH OF OUR FORECAST AREA...HOWEVER
STRONG THUNDERSTORMS DID DROP PEA-SIZED HAIL IN THE PARKTON
COMMUNITY OF NORTHERN ROBESON COUNTY EARLIER THIS AFTERNOON. THAT`S
THE SECOND DAY IN A ROW HAIL HAS FALLEN IN PARKTON.
NOW THAT THE CURRENT CONVECTIVE ACTIVITY HAS PUSHED NORTH INTO THE
FAYETTEVILLE/CLINTON AREA WE SHOULD BE ENTERING A LULL IN PRECIP
CHANCES WHICH WILL LAST UNTIL AT LEAST MIDNIGHT. PRECIPITATION
CHANCES MAY BEGIN TO INCREASE FROM WEST TO EAST LATE TONIGHT AS AN
UPPER LEVEL DISTURBANCE NOW NEAR THE AL/GA BORDER MOVES INTO THE
AREA...ACCOMPANIED BY A STREAM OF DEEPER MOISTURE IN THE 850-700 MB
LAYER. JET STREAM DYNAMICS ARE MARGINAL NOW WITH A 200/300 MB JET
STREAK ACROSS KY/OH. AS THIS JET STREAK MOVES FARTHER AWAY FROM THE
CAROLINAS OVERNIGHT THIS SHOULD TAKE AWAY WHAT LITTLE INFLUENCE THE
JET STREAK IS PROVIDING. I AM ONLY INCREASING POPS INTO THE 20-40
PERCENT RANGE LATE...HIGHEST INLAND.
WITH SUCH A WARM AND SOUPY AIRMASS OUT THERE LOWS SHOULD REMAIN IN
THE 70-72 RANGE ACROSS THE BOARD TONIGHT...15-18 DEGREES ABOVE
NORMAL FOR THIS DATE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...AN INTENSE LOW PRESSURE SYSTEM ACROSS THE
GREAT LAKES WILL SLOWLY MOVE EASTWARD THROUGH WED EVENTUALLY
LIFTING NORTH THROUGH THURSDAY ACROSS THE GREAT LAKES. THIS LOW
WILL DRAG A COLD FRONT EAST MARCHING THROUGH THE CAROLINAS WED
INTO THURS FINALLY REACHING THE COAST THURS NIGHT INTO EARLY FRI.
A VERY MOIST AND INCREASINGLY UNSTABLE ATMOSPHERE AHEAD OF THIS
FRONT WILL INCREASE THE CHC OF STRONG TO SEVERE CONVECTION THROUGH
WED INTO THURS. LOOKS LIKE THE THE GREATEST POTENTIAL FOR STRONG
TO SEVERE STORM STORMS WILL BE ACROSS THE INTERIOR CAROLINAS
INITIALLY BUT WILL EASE CLOSER TO THE COAST OVERNIGHT WED INTO
THURS. AS TEMPS INCREASE CLOSE TO 80 AND DEWPOINT TEMPS REMAIN
CLOSE TO 70...CAPE VALUES WILL INCREASE THROUGH WED UP ABOVE 2000
J/KG. AS LLJ INCREASES UP TO 40 TO 50 KTS PUMPING IN PLENTY OF
MOISTURE THROUGH WED INTO THURS WITH PCP WATER VALUES INCREASING
UP ABOVE 1.5 INCHES. EXPECT MORE DISCREET CELLS DEVELOPING IN THIS
MOIST AND UNSTABLE AIR MASS WELL AHEAD OF FRONT WITH POTENTIAL FOR
LARGE HAIL AND RISK OF TORNADOES. JUST AHEAD OF COLD FRONT EXPECT
MOISTURE TO POOL IN SQUALL LINE WITH PCP WATER VALUES REACHING UP
TO 1.9 INCHES...WELL ABOVE NORMAL. EXPECTED PRIMARY THREAT TO BE
DAMAGING WINDS IN MORE ORGANIZED SQUALL LINE.
ONGOING CONVECTION FROM PREVIOUS DAY AND CLOUDS MAY LIMIT CONVECTIVE
POTENTIAL ON THURS ALONG WITH THE FACT THAT THE LINE OF STORMS MAY
MOVE THROUGH EARLIER IN THE DAY. THIS WILL ALSO KEEP TEMPS LOWER
OVERALL REACHING INTO 70S. THEREFORE KEPT ENHANCED WORDING FOR
SEVERE POTENTIAL INLAND WED MAKING ITS WAY TO THE COAST LATER ON WED
AND THEN MORE GENERAL THUNDERSTORMS WITH HEAVY RAIN FOR THURS.
GREATEST POTENTIAL WILL BE CLOSER TO THE COAST ON THURS WHERE TEMPS
AND GREATEST MOISTURE WILL BE.
THE MID TO UPPER TROUGH WILL REMAIN WEST OF AREA AND THEREFORE WILL
NOT SEE GREAT PUSH FOR FRONT TO MOVE MUCH PAST THE COAST BY END OF
PERIOD. EXPECT DRY AIR TO MAKE ITS WAY IN AS WINDS VEER AROUND TO
THE W-SW THROUGH THE LOWER LEVELS LATE THURS INTO THURS NIGHT AND
WILL BEGIN CLEARING AND DIMINISHING POPS INTO THURS NIGHT.
CAA LATE THURS INTO EARLY FRI WILL ALLOW TEMPS TO DROP INTO THE 50S
OVERNIGHT THURS WITH DEWPOINT TEMPS MAKING THEIR WAY DOWN FROM THE
60S TO NEAR 70 WED INTO THURS TO 50 TO 55 BY FRI MORNING.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...AXIS OF A POSITIVELY-TILTED MID/UPPER TROUGH
WILL EXTEND FROM SOUTHERN ILLINOIS TO WEST TEXAS EARLY FRIDAY...AND
TRANSITION TO THE EASTERN SEABOARD BY SATURDAY NIGHT. A SLOWING AND
WEAKENING COLD FRONT LOOKS TO BE JUST OFFSHORE BY DAYBREAK FRIDAY
LEAVING A WEAK SURFACE PRESSURE FIELD IN ITS WAKE. ALTHOUGH THE
COLUMN WILL DRY FROM THE BOTTOM UP FRIDAY INTO SATURDAY...TIME-
HEIGHT CROSS SECTIONS INDICATE ENOUGH MOISTURE AND LIFT AVAILABLE TO
WARRANT AT LEAST A SMALL POP UNTIL THE 500 MB TROUGH AXIS PUSHES OFF
THE COAST. A DEEP LAYER OF NORTHWEST FLOW WILL BECOME ESTABLISHED
ABOVE 925 MB SUNDAY. STRONG LOW PRESSURE WILL SWEEP ACROSS THE GREAT
LAKES AND NORTHEAST CONUS SUNDAY NIGHT INTO MONDAY...WITH THE
ASSOCIATED COLD FRONT SLOWLY DROPPING SOUTH ACROSS NORTH CAROLINA.
THE FRONT IS EXPECTED TO STALL SOMEWHERE ACROSS THE CAROLINAS MONDAY
AS IT BEGINS TO PARALLEL THE UPPER FLOW.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 00Z...CONVECTION STILL FIRING OVER THE NORTHERN PORTION OF OUR
CWA...BUT SHOULD NOT AFFECT THE TERMINALS THIS EVENING OTHER THAN A
PASSING LIGHT SHOWER. SURFACE CAPE IS RAPIDLY DECREASING AND THE
HRRR MODEL...WHICH HAS BEEN PRETTY GOOD TODAY...IS SHOWING A FAIRLY
QUIET NIGHT WITH ISOLATED CONVECTION. ALONG THE COAST AND EVENTUALLY
INLAND...IFR STRATUS IS EXPECTED TO OVERTAKE THE AREA. THE MYRTLES
SHOULD SEE IT FIRST...ALMOST A SEA FOG SITUATION WITH THE HIGH
DEWPOINTS.
WEDNESDAY...IFR WILL LIFT TO MVFR WITH CONVECTION INCREASING
THROUGHOUT THE DAY. EVEN WITH THE CLOUD COVER...SHOULD SEE CAPES
OVER 1000 J/KG WITH PRECIPITABLE WATER APPROACHING TWO INCHES.
SHOWERS WILL BE FAIRLY WIDESPREAD BY MIDDAY INLAND...SPREADING TO
THE COAST BY 18Z OR SO. THE MARINE LAYER MAY BE A DETERRENT HOWEVER
AND MAY HAVE TO WEIGH THIS FOR THE NEXT SET OF FORECASTS. SOUTHWEST
WINDS WILL INCREASE WITH GUSTS NEAR 25 KTS COMMON BY MIDDAY.
EXTENDED OUTLOOK...SCATTERED AFTERNOON/EVENING SHOWERS AND
THUNDERSTORMS POSSIBLE THROUGH THURSDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM TUESDAY...WINDS ARE RIGHT WHERE WE EXPECTED THEM WITH
SEAS LAGGING BY PERHAPS HALF A FOOT. A SLOW INCREASING TREND IS
STILL EXPECTED OVERNIGHT IN RESPONSE TO THE STEADY SOUTH WIND.
PREVIOUS DISCUSSION FROM 730 PM FOLLOWS...
A COLD FRONT OVER WESTERN TENNESSEE AND MISSISSIPPI WILL MOVE EAST
OVER THE NEXT SEVERAL DAYS...FINALLY REACHING THE CAROLINA COAST
LATE THURSDAY. UNTIL THEN...MODERATE SOUTH WINDS WILL CONTINUE WITH
GRADUALLY BUILDING SEAS. BASED ON LATEST WIND FORECASTS AND WAVE
OBSERVATIONS FROM BUOYS I HAVE DELAYED THE ONSET OF SMALL CRAFT
ADVISORY CONDITIONS BY 5 HOURS...UNTIL 8 AM WEDNESDAY MORNING. WINDS
TONIGHT SHOULD AVERAGE 12-15 KNOTS FROM THE SOUTH WITH VERY LITTLE
GUSTINESS GIVEN THE STABLE THERMAL PROFILES AS WARM AIR RIDES OVER
THE RELATIVELY COLD OCEAN SURFACE. SEVERAL CLUSTERS OF THUNDERSTORMS
OVER INTERIOR EASTERN NORTH CAROLINA WILL PASS WELL NORTH OF OUR
COASTAL WATERS THIS EVENING. THERE IS A SMALL POTENTIAL OF SHOWERS
OR THUNDERSTORMS DEVELOPING LATE TONIGHT...BUT MORE LIKELY WEDNESDAY.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...SMALL CRAFT CONDITIONS WILL PERSIST THROUGH
MUCH OF THE PERIOD. STRONG AND GUSTY SOUTHERLY WINDS AHEAD OF A
SLOWLY APPROACHING COLD FRONT WILL INCREASE UP TO 15 TO 20 KTS EARLY
WED. WINDS MAY REACH ABOVE 20 KTS AS GRADIENT TIGHTENS AHEAD OF COLD
FRONT WED NIGHT INTO EARLY THURS...ESPECIALLY IN THE OUTER WATERS.
THE WINDS WILL VEER ON THURS BECOMING SW THROUGH LATE AFTN AND
WESTERLY BY MIDNIGHT INTO THE EARLY MORNING HOURS. AS THE WINDS VEER
AROUND BECOMING MORE OFFSHORE...SEAS WILL LOWER IN THE NEAR SHORE
WATERS BUT WILL REMAIN HIGH OFF SHORE A LITTLE LONGER INTO THE EARLY
MORNING HOURS.
THE STRONG SOUTHERLY PUSH AHEAD OF THE FRONT WILL KEEP SEAS UP
BETWEEN 4 TO 6 FT MOST OF THE PERIOD WITH OUTER WATERS REACHING
AROUND 7 FT WED NIGHT INTO THURS.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...A WEAK COLD FRONT IS EXPECTED TO BE JUST OFF
THE COAST FRIDAY MORNING. SCATTERED SHOWER/TSTM ACTIVITY IS EXPECTED
ALONG THE FRONT...AS WELL AS THE POTENTIAL FOR SOME SHOWER ACTIVITY
LINGERING INTO SATURDAY UNTIL THE MID-LEVEL TROUGH AXIS SHIFTS EAST
OF THE WATERS. THE PRESSURE FIELD BEHIND THE FRONT WILL BE WEAK...SO
ALTHOUGH A SHIFT TO NORTHWEST WINDS WILL OCCUR FRIDAY MORNING...
WINDS WILL BACK AROUND TO THE WEST-SOUTHWEST BY EARLY AFTERNOON. THE
GRADIENT ACROSS THE WATERS WILL REMAIN RATHER MODEST SATURDAY AND
SUNDAY BETWEEN A WEAK SURFACE HIGH CENTERED OVER THE NORTHERN GULF
OF MEXICO AND LOW PRESSURE SKIRTING ACROSS THE GREAT LAKES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 AM WEDNESDAY TO 6 PM EDT
THURSDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...CRM
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
641 PM EDT MON APR 28 2014
.SYNOPSIS...
UNSETTLED WEATHER WILL PERSIST OVER THE NEXT COUPLE OF DAYS. SHOWERS
AND THUNDERSTORMS ARE EXPECTED INCREASE IN COVERAGE THROUGH
WEDNESDAY AS A TROUGH OF LOW PRESSURE APPROACHES FROM THE WEST.
ANOTHER QUICK ROUND OF RAIN IS POSSIBLE LATE FRIDAY AND SATURDAY
BEFORE CONDITIONS DRY OUT INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 PM MONDAY...A CLUSTER OF STRONG TO SEVERE THUNDERSTORMS
DEVELOPED ALONG A STATIONARY FRONT ACROSS SOUTHERN NORTH CAROLINA A
FEW HOURS AGO. SUBJECTIVE SURFACE ANALYSIS SHOWED SIGNIFICANT
BACKING OF THE LOW-LEVEL WIND ACROSS THE COASTAL PLAIN OF NC WHILE
MODIFIED 18Z MODEL SOUNDINGS INDICATED CAPE AS HIGH AS 2700 J/KG
EARLIER. MULTICELL STORMS DEVELOPED BUT DID NOT DISPLAY SIGNIFICANT
DEVIANT MOTION AS THEY MIGHT HAVE HAD SUPERCELLS DEVELOPED. STILL...
HIGH REFLECTIVITY CORES REACHED INTO COLD ENOUGH LAYERS OF THE
ATMOSPHERE TO LEAD US TO BELIEVE LARGE HAIL WAS A SIGNIFICANT
THREAT. IF YOU OBSERVED HAIL OR WIND DAMAGE ACROSS ROBESON OR BLADEN
COUNTIES THIS EVENING PLEASE LET US KNOW!
THE FRONT SHOULD REMAIN NEARLY STATIONARY ACROSS SOUTHERN NORTH
CAROLINA THIS EVENING...MAINLY JUST NORTH OF LUMBERTON AND
ELIZABETHTOWN ARCING NORTHEASTWARD TOWARD NEW BERN ALONG THE COAST.
THIS WILL LEAVE OUR FORECAST AREA IN A WARM AND HUMID TROPICAL
AIRMASS WITH DEWPOINTS AND LOW TEMPERATURES FORECAST TO BE IN THE
UPPER 60S. THE 500 MB RIDGE AXIS THAT HAS HELPED TO SUPPRESS
PRECIPITATION OVER THE PAST FEW HOURS WILL FINALLY PUSH OFFSHORE
LATE TONIGHT...AND THERE IS THE POTENTIAL FOR A REDEVELOPMENT OF AT
LEAST ISOLATED SHOWERS/T-STORMS JUST BEFORE DAYBREAK AS WIND VECTORS
BECOME DIFLUENT ALOFT AND THE 850 MB WIND BACKS AND STRENGTHENS.
PREVIOUS DISCUSSION FROM 230 PM FOLLOWS...
INCREASINGLY WARM AND MORE UNSTABLE AIR MASS WITH TEMPS INTO THE 80S
MOST PLACES. MODELS STILL SHOW MID TO UPPER RIDGE LINED UP THE
SOUTHEAST COAST WHICH SHOULD HELP TO INHIBIT SOME OF THE STRONGEST
CONVECTION RUNNING SOUTH...BUT AS TEMPS WARMED INTO THE 80S AND
DEWPOINTS INTO THE MID 60S CLOSER TO 70 OVER SOUTH CAROLINA. HRRR
AND RUC SHOWING BEST CAPE LINED UP INLAND FROM SOUTH TO NORTH TOWARD
DARLINGTON AND MARLBORO...BUT MAIN FOCUS OF STRONGER CONVECTION WILL
BE ALONG THE LINGERING FRONTAL BOUNDARY JUST TO THE NORTH OF LOCAL
FORECAST AREA. EXPECT SCT CONVECTION OVER THE AREA WITH MAIN FOCUS
ALONG SEA BREEZE CONVERGENT BOUNDARY AND RUNNING ALONG LINGERING
FRONTAL BOUNDARY. JUST NORTH OF BOUNDARY STILL SEEING TEMPS NOT EVEN
REACHING 70 WITH COOLER AIR WEDGED IN.
BEST HELICITY WILL RUN ALONG WARM FRONT WITH VALUES ABOVE 200 JUST
TO NORTH. OVERALL SHOULD BE RATHER FINE BOUNDARY OF STRONGEST STORMS
AS FORCING REMAINS WEAKER FARTHER SOUTH DUE TO INCREASED SUBSIDENCE
WITH MID TO UPPER RIDGE OVER THE SOUTHEAST COAST. OVERALL THREAT OF
HAIL AND STRONG WINDS WITH ANY STORMS THAT MAY REACH INTO OUR
NORTHERN TIER COUNTIES. THE STEERING FLOW WILL PUSH ANY SHWRS/TSTMS
THAT DEVELOP TOWARD THE COAST BUT THE MORE STABILIZED AIR BEHIND SEA
BREEZE SHOULD KEEP THE IMMEDIATE COAST FREE OF STORMS. KEPT POPS
VERY CLOSE TO PREVIOUS FORECAST WITH ONLY MINOR ADJUSTMENTS AND WILL
UPDATE AS NEEDED ONCE CONVECTION FLARES. SHOULD SEE A FAIR AMOUNT OF
CLOUDS AS CONVECTIVE DEBRIS CLOUDS WILL BE STEERED EAST MIXED WITH
CU FIELD ACROSS THE AREA.
THE STALLED BOUNDARY WILL BEGIN TO LIFT NORTH THROUGH TONIGHT AND
EXPECT LOCALIZED CONVECTION TO SHUT DOWN AS HEATING OF THE DAY CUTS
OFF AFTER SUNSET. THEREFORE WILL TAPER OFF POPS AFTER SUNSET LEAVING
BEST CHC TO THE NORTH ALONG BOUNDARY. SHOULD BE A RELATIVELY QUIET
NIGHT WITH LOWS WELL ABOVE CLIMO...RUNNING IN THE MID 60S IN A WARM
AND HUMID AIRMASS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...ATTENTION THROUGHOUT THE ENTIRE FORECAST
PERIOD WILL FOCUS ON UNSETTLED WEATHER...INCLUDING THE THREAT FOR
SEVERE WEATHER JUST AHEAD OF AN APPROACHING COLD FRONT. LATEST
GUIDANCE CONTINUES TO ILLUSTRATE A LONGWAVE TROUGH ACROSS THE CONUS
WITH A PERSISTENT UPPER LEVEL LOW WHICH WILL SLOWLY PROGRESS ACROSS
THE MIDWEST OVER THE NEXT COUPLE OF DAYS. WARM TEMPERATURES AND
SOUTHWEST FLOW WILL ALLOW FOR A MOISTURE-RICH ATMOSPHERE...AS
DEWPOINTS ARE WELL IN THE 60S...TO REMAIN IN PLACE WITH HIGHS ON
TUESDAY IN THE LOWER 80S ACROSS THE ENTIRE FORECAST AREA. SHOWERS
AND THUNDERSTORMS ARE EXPECTED THROUGHOUT THE DAY ON TUESDAY WHICH
IS IN GOOD AGREEMENT AS OUR AREA IS INCLUDED IN SPC`S SLIGHT RISK.
INTO WEDNESDAY...CONDITIONS WILL CONTINUE TO PROGRESS IN
INCREASE...AS IT LOOKS THE BETTER INSTABILITY AND LIFT WILL MOVE
INTO THE CENTRAL SC/NC/VA AREA...WITH A HEIGHTENED POSSIBILITY OF
SEVERE ESPECIALLY IN OUR WESTERN ZONES. DIFFICULTY WILL BE TIMING AS
MODELS HAVE EVER SO SLIGHTLY SLOWED DOWN THE PROGRESSION OF THE
SYSTEM IN PAST RUNS. HOWEVER...OVERALL ANTICIPATE MAIN THREAT TO
OCCUR WEDNESDAY THROUGHOUT THE DAY WITH AMPLE DIURNAL HEATING WITH
HIGHS ON WEDNESDAY AGAIN IN THE 80S...INTO EARLY THURSDAY MORNING.
WILL ALSO TAKE INTO ACCOUNT THE INTERACTION OF THE SEA BREEZE AS
WELL ON BOTH DAYS AND ANY OTHER WANDERING BOUNDARIES ABOUT THE AREA.
THE PRIMARY THREATS WILL BE HAIL AND DAMAGING WINDS...ALONG WITH THE
POSSIBILITY OF TORNADOES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...THURSDAY MAY BE RATHER ACTIVE. THE UPPER RIDGE
AXIS WILL BE OFFSHORE ALLOWING FOR DEEP SWRLY FLOW. SURFACE BOUNDARY
AND UPPER LEVEL VORT MAXES MAY SPONSOR DEEP ENOUGH LIFT FOR FAIRLY
WIDESPREAD CONVECTION. WIND FIELDS MAY BE STRONG ENOUGH FOR STORM
ORGANIZATION WITH DAMAGING WIND AND/OR HAIL. MORE QUESTIONABLE
WHETHER OR NOT INSTABILITY MANAGES TO DEVELOP HOWEVER. BOUNDARY
PUSHES OFFSHORE THURSDAY NIGHT WHICH MAY ALLOW FOR A COOLER AND
DRIER FRIDAY. TRAILING UPPER ENERGY ON SATURDAY BUT TOUGH CALL AS TO
WHETHER OR NOT ENOUGH MOISTURE AROUND FOR MEANINGFUL RAIN CHANCES.
DRY WNW FLOW FOR SUNDAY AND MONDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z..STILL LOOKING FOR CONVECTION TO FIRE ALONG A DIFFUSE WARM
FRONT THIS AFTERNOON. MOST OF THE ACTIVITY WILL BE OVER THE NORTHERN
THIRD OF THE CWA...BUT COULD NOT RULE OUT WEAK CONVECTION TO THE
SOUTH ALONG THE SEA BREEZE BOUNDARY. BRIEF IFR PERIODS ARE
POSSIBLE...MAINLY AT LBT AND ILM. MOST OF THE ACTIVITY WILL END THIS
EVENING AS THE WARM FRONT WAVES NORTH. WITH THE SOUTHWESTERLY FLOW
TONIGHT...IFR STRATUS IS A REASONABLE BET. TUESDAY...BECOMING VFR
WITH ANOTHER ROUND OF CONVECTION POSSIBLE BY THE END OF THE FORECAST
PERIOD.
EXTENDED OUTLOOK...SCATTERED AFTERNOON/EVENING SHOWERS AND
THUNDERSTORMS POSSIBLE THROUGH THURSDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 645 PM MONDAY...BASED ON OBSERVATIONS AND THE 18Z MODELS I
HAVE INCREASED WIND SPEEDS THROUGH THE NIGHT BY A FEW KNOTS...WITH
10-15 KNOTS EXPECTED FOR MOST AREAS THROUGH THE NIGHT. THAT SHOULD
SUPPORT 2 FOOT SEAS BUILDING THROUGH 3 FEET OVERNIGHT. A CLUSTER OF
STRONG TO SEVERE THUNDERSTORMS ACROSS SOUTHEASTERN NC SHOULD LARGELY
MISS THE COASTAL WATERS...BUT THERE IS A POTENTIAL FOR ISOLATED
SHOWERS OR T-STORMS THIS EVENING...THEN PERHAPS REDEVELOPING VERY
LATE TONIGHT. PREVIOUS DISCUSSION FROM 230 PM FOLLOWS...
QUIET MARINE CONDITIONS OVERALL THROUGH THIS AFTERNOON. HIGH
PRESSURE REMAINS OVER THE AREA WITH LINGERING BOUNDARY LIFTING NORTH
OF THE THE WATERS. GRADIENT REMAINS LIGHT WITH SOUTH TO SOUTHEAST
FLOW REMAINING UNDER 10 KT THROUGH THE MORNING HOURS WITH SEAS 2 FT
OR LESS. MAY SEE A FEW LINGERING SHOWERS MAKE IT OVER THE WATERS
JUST ALONG NORTHERN PORTION OF LOCAL WATERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...EXPECT SOUTH- SOUTHWEST FLOW TO PERSIST
THROUGH THE FORECAST PERIOD WITH INCREASING WINDS WEDNESDAY INTO
WEDNESDAY EVENING WHERE WINDS WILL INCREASE TO AROUND 20 TO 25
KTS...WHILE THE REMAINDER OF THE PERIOD ANTICIPATE 15 TO 20 KTS
WITH ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE. AS
FOR SEAS...2 TO 4 FT WITH 5 FT POSSIBLE. COULD SEE 6 TO 7 FT
POSSIBLE IN THE OUTER WATERS WEDNESDAY INTO THURSDAY MORNING.
ANTICIPATE CONDITIONS WILL WARRANT A SMALL CRAFT ADVISORY
WEDNESDAY EVENING.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 300 PM MONDAY...PREFRONTAL FLOW REGIME ON THURSDAY PROBABLY
STRONG ENOUGH TO WARRANT A SMALL CRAFT ADVISORY. A WINDSHIFT TO A
MORE OFFSHORE DIRECTION THURSDAY NIGHT INTO FRIDAY PAIRED WITH A
DOWNWARD TREND IN THE WIND SPEED WILL ALLOW ADVISORY TO BE DROPPED.
OFFSHORE WINDS AND FAIRLY SEASONABLE SEAS CONTINUES INTO SATURDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FOR INLAND NEW HANOVER COUNTY FROM 9 PM
UNTIL MIDNIGHT.
MARINE...NONE.
&&
$$
SYNOPSIS...SGL
NEAR TERM...RGZ/TRA
SHORT TERM...SGL
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
348 PM EDT MON APR 28 2014
.SYNOPSIS...
UNSETTLED WEATHER WILL PERSIST OVER THE NEXT COUPLE OF DAYS AS
SHOWERS AND THUNDERSTORMS ARE EXPECTED INCREASE IN COVERAGE TODAY
THROUGH WEDNESDAY AS A TROUGH OF LOW PRESSURE APPROACHES FROM THE
WEST. ANOTHER QUICK ROUND OF RAIN IS POSSIBLE LATE FRIDAY AND
SATURDAY BEFORE CONDITIONS DRY OUT INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...INCREASINGLY WARM AND MORE UNSTABLE AIR MASS
WITH TEMPS INTO THE 80S MOST PLACES. MODELS STILL SHOW MID TO UPPER
RIDGE LINED UP THE SOUTHEAST COAST WHICH SHOULD HELP TO INHIBIT SOME
OF THE STRONGEST CONVECTION RUNNING SOUTH...BUT AS TEMPS WARMED INTO
THE 80S AND DEWPOINTS INTO THE MID 60S CLOSER TO 70 OVER SOUTH
CAROLINA. HRRR AND RUC SHOWING BEST CAPE LINED UP INLAND FROM SOUTH
TO NORTH TOWARD DARLINGTON AND MARLBORO...BUT MAIN FOCUS OF STRONGER
CONVECTION WILL BE ALONG THE LINGERING FRONTAL BOUNDARY JUST TO THE
NORTH OF LOCAL FORECAST AREA. EXPECT SCT CONVECTION OVER THE AREA
WITH MAIN FOCUS ALONG SEA BREEZE CONVERGENT BOUNDARY AND RUNNING
ALONG LINGERING FRONTAL BOUNDARY. JUST NORTH OF BOUNDARY STILL
SEEING TEMPS NOT EVEN REACHING 70 WITH COOLER AIR WEDGED IN.
BEST HELICITY WILL RUN ALONG WARM FRONT WITH VALUES ABOVE 200 JUST
TO NORTH. OVERALL SHOULD BE RATHER FINE BOUNDARY OF STRONGEST STORMS
AS FORCING REMAINS WEAKER FARTHER SOUTH DUE TO INCREASED SUBSIDENCE
WITH MID TO UPPER RIDGE OVER THE SOUTHEAST COAST. OVERALL THREAT OF
HAIL AND STRONG WINDS WITH ANY STORMS THAT MAY REACH INTO OUR
NORTHERN TIER COUNTIES. THE STEERING FLOW WILL PUSH ANY SHWRS/TSTMS
THAT DEVELOP TOWARD THE COAST BUT THE MORE STABILIZED AIR BEHIND SEA
BREEZE SHOULD KEEP THE IMMEDIATE COAST FREE OF STORMS. KEPT POPS
VERY CLOSE TO PREVIOUS FORECAST WITH ONLY MINOR ADJUSTMENTS AND WILL
UPDATE AS NEEDED ONCE CONVECTION FLARES. SHOULD SEE A FAIR AMOUNT OF
CLOUDS AS CONVECTIVE DEBRIS CLOUDS WILL BE STEERED EAST MIXED WITH
CU FIELD ACROSS THE AREA.
THE STALLED BOUNDARY WILL BEGIN TO LIFT NORTH THROUGH TONIGHT AND
EXPECT LOCALIZED CONVECTION TO SHUT DOWN AS HEATING OF THE DAY CUTS
OFF AFTER SUNSET. THEREFORE WILL TAPER OFF POPS AFTER SUNSET LEAVING
BEST CHC TO THE NORTH ALONG BOUNDARY. SHOULD BE A RELATIVELY QUIET
NIGHT WITH LOWS WELL ABOVE CLIMO...RUNNING IN THE MID 60S IN A WARM
AND HUMID AIRMASS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...ATTENTION THROUGHOUT THE ENTIRE FORECAST
PERIOD WILL FOCUS ON UNSETTLED WEATHER...INCLUDING THE THREAT FOR
SEVERE WEATHER JUST AHEAD OF AN APPROACHING COLD FRONT. LATEST
GUIDANCE CONTINUES TO ILLUSTRATE A LONGWAVE TROUGH ACROSS THE CONUS
WITH A PERSISTENT UPPER LEVEL LOW WHICH WILL SLOWLY PROGRESS ACROSS
THE MIDWEST OVER THE NEXT COUPLE OF DAYS. WARM TEMPERATURES AND
SOUTHWEST FLOW WILL ALLOW FOR A MOISTURE-RICH ATMOSPHERE...AS
DEWPOINTS ARE WELL IN THE 60S...TO REMAIN IN PLACE WITH HIGHS ON
TUESDAY IN THE LOWER 80S ACROSS THE ENTIRE FORECAST AREA. SHOWERS
AND THUNDERSTORMS ARE EXPECTED THROUGHOUT THE DAY ON TUESDAY WHICH
IS IN GOOD AGREEMENT AS OUR AREA IS INCLUDED IN SPC`S SLIGHT RISK.
INTO WEDNESDAY...CONDITIONS WILL CONTINUE TO PROGRESS IN
INCREASE...AS IT LOOKS THE BETTER INSTABILITY AND LIFT WILL MOVE
INTO THE CENTRAL SC/NC/VA AREA...WITH A HEIGHTENED POSSIBILITY OF
SEVERE ESPECIALLY IN OUR WESTERN ZONES. DIFFICULTY WILL BE TIMING AS
MODELS HAVE EVER SO SLIGHTLY SLOWED DOWN THE PROGRESSION OF THE
SYSTEM IN PAST RUNS. HOWEVER...OVERALL ANTICIPATE MAIN THREAT TO
OCCUR WEDNESDAY THROUGHOUT THE DAY WITH AMPLE DIURNAL HEATING WITH
HIGHS ON WEDNESDAY AGAIN IN THE 80S...INTO EARLY THURSDAY MORNING.
WILL ALSO TAKE INTO ACCOUNT THE INTERACTION OF THE SEA BREEZE AS
WELL ON BOTH DAYS AND ANY OTHER WANDERING BOUNDARIES ABOUT THE AREA.
THE PRIMARY THREATS WILL BE HAIL AND DAMAGING WINDS...ALONG WITH THE
POSSIBILITY OF TORNADOES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...THURSDAY MAY BE RATHER ACTIVE. THE UPPER RIDGE
AXIS WILL BE OFFSHORE ALLOWING FOR DEEP SWRLY FLOW. SURFACE BOUNDARY
AND UPPER LEVEL VORT MAXES MAY SPONSOR DEEP ENOUGH LIFT FOR FAIRLY
WIDESPREAD CONVECTION. WIND FIELDS MAY BE STRONG ENOUGH FOR STORM
ORGANIZATION WITH DAMAGING WIND AND/OR HAIL. MORE QUESTIONABLE
WHETHER OR NOT INSTABILITY MANAGES TO DEVELOP HOWEVER. BOUNDARY
PUSHES OFFSHORE THURSDAY NIGHT WHICH MAY ALLOW FOR A COOLER AND
DRIER FRIDAY. TRAILING UPPER ENERGY ON SATURDAY BUT TOUGH CALL AS TO
WHETHER OR NOT ENOUGH MOISTURE AROUND FOR MEANINGFUL RAIN CHANCES.
DRY WNW FLOW FOR SUNDAY AND MONDAY.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
AS OF 18Z..STILL LOOKING FOR CONVECTION TO FIRE ALONG A DIFFUSE WARM
FRONT THIS AFTERNOON. MOST OF THE ACTIVITY WILL BE OVER THE NORTHERN
THIRD OF THE CWA...BUT COULD NOT RULE OUT WEAK CONVECTION TO THE
SOUTH ALONG THE SEA BREEZE BOUNDARY. BRIEF IFR PERIODS ARE
POSSIBLE...MAINLY AT LBT AND ILM. MOST OF THE ACTIVITY WILL END THIS
EVENING AS THE WARM FRONT WAVES NORTH. WITH THE SOUTHWESTERLY FLOW
TONIGHT...IFR STRATUS IS A REASONABLE BET. TUESDAY...BECOMING VFR
WITH ANOTHER ROUND OF CONVECTION POSSIBLE BY THE END OF THE FORECAST
PERIOD.
EXTENDED OUTLOOK...SCATTERED AFTERNOON/EVENING SHOWERS AND
THUNDERSTORMS POSSIBLE THROUGH THURSDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...QUIET MARINE CONDITIONS OVERALL THROUGH
THIS AFTERNOON. HIGH PRESSURE REMAINS OVER THE AREA WITH
LINGERING BOUNDARY LIFTING NORTH OF THE THE WATERS. GRADIENT
REMAINS LIGHT WITH SOUTH TO SOUTHEAST FLOW REMAINING UNDER 10 KT
THROUGH THE MORNING HOURS WITH SEAS 2 FT OR LESS. MAY SEE A FEW
LINGERING SHOWERS MAKE IT OVER THE WATERS JUST ALONG NORTHERN
PORTION OF LOCAL WATERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...EXPECT SOUTH- SOUTHWEST FLOW TO PERSIST
THROUGH THE FORECAST PERIOD WITH INCREASING WINDS WEDNESDAY INTO
WEDNESDAY EVENING WHERE WINDS WILL INCREASE TO AROUND 20 TO 25
KTS...WHILE THE REMAINDER OF THE PERIOD ANTICIPATE 15 TO 20 KTS
WITH ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE. AS
FOR SEAS...2 TO 4 FT WITH 5 FT POSSIBLE. COULD SEE 6 TO 7 FT
POSSIBLE IN THE OUTER WATERS WEDNESDAY INTO THURSDAY MORNING.
ANTICIPATE CONDITIONS WILL WARRANT A SMALL CRAFT ADVISORY
WEDNESDAY EVENING.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 300 PM MONDAY...PREFRONTAL FLOW REGIME ON THURSDAY PROBABLY
STRONG ENOUGH TO WARRANT A SMALL CRAFT ADVISORY. A WINDSHIFT TO A
MORE OFFSHORE DIRECTION THURSDAY NIGHT INTO FRIDAY PAIRED WITH A
DOWNWARD TREND IN THE WIND SPEED WILL ALLOW ADVISORY TO BE DROPPED.
OFFSHORE WINDS AND FAIRLY SEASONABLE SEAS CONTINUES INTO SATURDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SGL
NEAR TERM...RGZ
SHORT TERM...SGL
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
230 PM EDT MON APR 28 2014
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST UNITED STATES WILL CONTINUE TO
BRING MILD SOUTHERLY WINDS TO THE REGION. SHOWERS AND THUNDERSTORMS
WILL INCREASE IN COVERAGE TODAY THROUGH WEDNESDAY AS A TROUGH OF LOW
PRESSURE APPROACHES FROM THE WEST. ANOTHER QUICK ROUND OF RAIN IS
POSSIBLE LATE FRIDAY AND SATURDAY BEFORE CONDITIONS DRY OUT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...INCREASINGLY WARM AND MORE UNSTABLE AIR MASS
WITH TEMPS INTO THE 80S MOST PLACES. MODELS STILL SHOW MID TO UPPER
RIDGE LINED UP THE SOUTHEAST COAST WHICH SHOULD HELP TO INHIBIT SOME
OF THE STRONGEST CONVECTION RUNNING SOUTH...BUT AS TEMPS WARMED INTO
THE 80S AND DEWPOINTS INTO THE MID 60S CLOSER TO 70 OVER SOUTH
CAROLINA. HRRR AND RUC SHOWING BEST CAPE LINED UP INLAND FROM SOUTH
TO NORTH TOWARD DARLINGTON AND MARLBORO...BUT MAIN FOCUS OF STRONGER
CONVECTION WILL BE ALONG THE LINGERING FRONTAL BOUNDARY JUST TO THE
NORTH OF LOCAL FORECAST AREA. EXPECT SCT CONVECTION OVER THE AREA
WITH MAIN FOCUS ALONG SEA BREEZE CONVERGENT BOUNDARY AND RUNNING
ALONG LINGERING FRONTAL BOUNDARY. JUST NORTH OF BOUNDARY STILL
SEEING TEMPS NOT EVEN REACHING 70 WITH COOLER AIR WEDGED IN.
BEST HELICITY WILL RUN ALONG WARM FRONT WITH VALUES ABOVE 200 JUST
TO NORTH. OVERALL SHOULD BE RATHER FINE BOUNDARY OF STRONGEST STORMS
AS FORCING REMAINS WEAKER FARTHER SOUTH DUE TO INCREASED SUBSIDENCE
WITH MID TO UPPER RIDGE OVER THE SOUTHEAST COAST. THE STEERING FLOW
WILL PUSH ANY SHWRS/TSTMS THAT DEVELOP TOWARD THE COAST BUT THE MORE
STABILIZED AIR BEHIND SEA BREEZE SHOULD KEEP THE IMMEDIATE COAST
FREE OF STORMS. KEPT POPS VERY CLOSE TO PREVIOUS FORECAST WITH ONLY
MINOR ADJUSTMENTS AND WILL UPDATE AS NEEDED ONCE CONVECTION FLARES.
SHOULD SEE CLOUDS BLANKET MUCH OF THE AREA THROUGH THIS AFTERNOON AS
CONVECTIVE DEBRIS CLOUDS WILL BE STEERED EAST AND HIGH CLOUDS WILL
SPILL OVER THE MID TO UPPER RIDGE INTO LOCAL AREA.
THE STALLED BOUNDARY WILL BEGIN TO LIFT NORTH THROUGH TONIGHT AND
EXPECT LOCALIZED CONVECTION TO SHUT DOWN AS HEATING OF THE DAY CUTS
OFF AFTER SUNSET. THEREFORE WILL TAPER OFF POPS AFTER SUNSET LEAVING
BEST CHC TO THE NORTH ALONG BOUNDARY. SHOULD BE A RELATIVELY QUIET
NIGHT WITH ABUNDANT CLOUD COVER AND LOWS WELL ABOVE CLIMO...RUNNING
IN THE MID 60S IN A WARM AND HUMID AIRMASS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...ALL EYES WILL BE ON THE SYSTEM NOW MOVING ACROSS
THE CENTRAL U.S AS IT MAKES ITS MOVE ON THE EAST COAST. THE
GFS...WHICH I HAVE BEEN LEANING TOWARD FOR A FEW CYCLES NOW REMAINS
CONSISTENT WITH THE BEST LIFT AND MOISTURE COUPLING LATE WEDNESDAY
AND INTO THE MORNING HOURS THURSDAY. I HAVE INCREASED POPS BASICALLY
ACROSS THE BOARD MORE SO FOR THE LATER PERIODS. SPC CONTINUES TO
HAVE THE AREA IN A SLIGHT RISK FOR BOTH DAYS. TEMPERATURE GUIDANCE
IS IN GOOD AGREEMENT OUTSIDE OF DAYTIME HIGHS FOR WEDNESDAY WITH THE
NAM/MET NUMBERS ONCE AGAIN COOLER. INHERITED BLEND WILL SUFFICE FOR
NOW.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...THE FOCUS FOR THE EXTENDED BEGINS TO SHIFT FROM
THE LONG ADVERTISED SYSTEM THAT IS CURRENTLY PLODDING ACROSS THE
CENTRAL U.S TO A SECONDARY WAVE LATE IN THE PERIOD. THE LATEST
MEDIUM RANGE GUIDANCE CONTINUES TO ADVERTISE A WET SCENARIO MAINLY
ALONG THE COAST. I HAVE TWEAKED THE POPS FOR SATURDAY TO REPRESENT
MORE OF A COASTAL SYSTEM ALTHOUGH THERE IS STILL PLENTY OF TIME FOR
THIS TO CHANGE. POPS REMAIN IN THE FORECAST FOR THURSDAY AND FRIDAY
MOSTLY VIA THE LOWER CONFIDENCE IN THE PROGRESS OF THE INITIAL
SYSTEM. NO CHANGES TO THE TEMPERATURE FORECAST.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z..STILL LOOKING FOR CONVECTION TO FIRE ALONG A DIFFUSE WARM
FRONT THIS AFTERNOON. MOST OF THE ACTIVITY WILL BE OVER THE NORTHERN
THIRD OF THE CWA...BUT COULD NOT RULE OUT WEAK CONVECTION TO THE
SOUTH ALONG THE SEA BREEZE BOUNDARY. BRIEF IFR PERIODS ARE
POSSIBLE...MAINLY AT LBT AND ILM. MOST OF THE ACTIVITY WILL END THIS
EVENING AS THE WARM FRONT WAVES NORTH. WITH THE SOUTHWESTERLY FLOW
TONIGHT...IFR STRATUS IS A REASONABLE BET. TUESDAY...BECOMING VFR
WITH ANOTHER ROUND OF CONVECTION POSSIBLE BY THE END OF THE FORECAST
PERIOD.
EXTENDED OUTLOOK...SCATTERED AFTERNOON/EVENING SHOWERS AND
THUNDERSTORMS POSSIBLE THROUGH THURSDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...QUIET MARINE CONDITIONS OVERALL THROUGH
THIS AFTERNOON. HIGH PRESSURE REMAINS OVER THE AREA WITH
LINGERING BOUNDARY LIFTING NORTH OF THE THE WATERS. GRADIENT
REMAINS LIGHT WITH SOUTH TO SOUTHEAST FLOW REMAINING UNDER 10 KT
THROUGH THE MORNING HOURS WITH SEAS 2 FT OR LESS. MAY SEE A FEW
LINGERING SHOWERS MAKE IT OVER THE WATERS JUST ALONG NORTHERN
PORTION OF LOCAL WATERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...A SOUTH TO OCCASIONALLY SOUTHEAST FLOW WILL
PREVAIL THROUGH THE PERIOD. THE STRONGEST WINDS SHOULD OCCUR LATE
WEDNESDAY WHEN A RANGE OF 20-25 KNOTS. FOR THE MOST PART A RANGE OF
15-20 KNOTS SHOULD BE FAIRLY PERSISTENT BEFORE THIS. SEAS WILL
GRADUALLY BUILD FROM AN INITIAL RANGE OF 1-3 FEET TO 3-5 AND
POSSIBLY 4-6 FEET BY THE END OF SECOND HALF OF THE PERIOD.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...THE MAIN ISSUE FOR THE MARINE COMMUNITY WILL BE
THE TIMING OF THE WIND SHIFT WITH THE FRONT ASSOCIATED WITH THE MAIN
INITIAL SYSTEM. THIS SHOULD OCCUR LATE THURSDAY/EARLY FRIDAY
ALTHOUGH CONFIDENCE IS LOW DUE TO THE SLOW NATURE OF THIS SYSTEM.
PRECEDING THIS...EXPECT A SOUTHWEST FLOW OF 15-20 KNOTS. FOR FRIDAY
EXPECT A LIGHTER AND MORE VARIABLE FLOW. SIGNIFICANT SEAS WILL BE
HOVERING AT OR JUST BELOW SMALL CRAFT CRITERIA THURSDAY 3-5 FEET
DROPPING SLIGHTLY FRIDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 PM EDT MON APR 28 2014
.SYNOPSIS...A STALLED SURFACE BOUNDARY ACROSS CENTRAL NC WILL LIFT
NORTHWARD AS A WARM FRONT THIS AFTERNOON. A WARM...MOIST AND
UNSTABLE AIR MASS WILL RESIDE OVER CENTRAL NC TONIGHT THROUGH
WEDNESDAY NIGHT. A SERIES OF UPPER LEVEL DISTURBANCES WILL INTERACT
WITH THIS AIR MASS TRIGGERING SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
AS OF 1040 AM MONDAY...
A WEAK COLD FRONT AND SHALLOW STABLE AIRMASS SETTLED SOUTH THROUGH
THE AREAS OVERNIGHT...MAKING IT ESSENTIALLY TO THE SC BORDER AND
CREATING A RATHER LARGE GRADIENT IN TEMPS AND DEWPOINTS. THE PARENT
SURFACE HIGH BEHIND THE FRONT WILL CONTINUE TO SUPPLY A
NORTHEASTERLY WIND TODAY...BUT WITH CLEARING ALREADY OCCURRING ACROSS
THE SOUTHERN PIEDMONT AND A SOUTHWESTERLY WIND AT 925MB...THE BOUNDARY
SHOULD MIX BACK TO THE NORTH TODAY. HIGHS FOR TODAY ARE TOUGH GIVEN
THE VARYING CLOUD COVER AND SLOWLY VEERING SURFACE WINDS ACROSS THE
SOUTH. TEMPS OVER PORTION OF SC HAVE ALREADY JUMPED INTO THE MID
AND UPPER 70S. ACROSS THE NORTH THE AMOUNT OF SUN IS A BIT MORE
UNCERTAIN...WITH ADDITIONAL CLOUD COVER MOVING EAST ACROSS THE BLUE
RIDGE. ADJUSTMENTS TO TEMP TRENDS YIELDS MID 60S NORTH TO LOWER 80S
SOUTH.
REGARDING CONVECTION... THE MAIN LIMITING FACTOR IS THE SHORTWAVE
RIDGE OVERHEAD...BUT FORECAST SOUNDINGS SUGGEST HEATING AND
MOISTURE RECOVER WILL BE ABLE TO OVERCOME THE MID-LEVEL CAP. THE
LATEST RAP RUNS SHOW AN INSTABILITY AXIS ON THE ORDER OF 500-1000
J/KG MLCAPE NOSING NORTH ACROSS THE SOUTHERN PIEDMONT BY
MIDDAY...WITH DESTABILIZATION TO THE EAST CROSS THE SANDHILLS AND
SOUTHERN COASTAL PLAIN WITH TIME. THE SEEMS TO MESH WELL WITH
SATELLITE TRENDS AND DEWPOINTS RECOVERING INTO THE MID TO UPPER
60S....SO AREAS SOUTH OF HWY 64 LOOK TO MOST FAVORABLE FOR
CONVECTION THIS AFTERNOON. BULK SHEAR WILL BE STRONGER TO THE
NORTH...BUT GUIDANCE SUGGESTS AS MUCH AS 30KT WHICH COULD SUPPORT
SOME MULTICELL CLUSTERS WITH A GENERAL MOTION FROM WEST TO EAST.
THE MAIN THREAT FROM STORMS WILL BE DAMAGING WINDS...THOUGH STORMS
FARTHER NORTH IN THE VICINITY OF THE RETREATING SURFACE BOUNDARY AND
BACKED SURFACE WINDS WILL ENCOUNTER GREATER SHEAR AND HAVE A BETTER
CHANCE OF ROTATING. AGAIN...THE THREAT OF SEVERE WEATHER IS
CONDITIONED UPON DEVELOPMENT OF STORMS...WHICH SHOULD BE MOSTLY
SCATTERED IN NATURE. -SMITH
TONIGHT...SFC FRONT PROJECTED TO BE STALLED ACROSS THE NORTHERN
COUNTIES. WEAK CONVERGENCE ALONG THIS FEATURE WILL MAINTAIN A
THREAT FOR SCATTERED SHOWERS THROUGH THE NIGHT. EXPECT SHOWERS TO BE
MORE ISOLATED ACROSS THE SOUTH. RATHER MILD TONIGHT WITH MIN TEMPS
NO LOWER THAN THE MID 60S ACROSS THE SOUTH...TRENDING TO THE UPPER
50S/NEAR 60 SOUTH.
TUESDAY AND TUESDAY NIGHT...ACTIVE WEATHER PATTERN APPEARS LIKELY
ACROSS CENTRAL NC WITH A CHANCE FOR MORE THAN ONE ROUND OF STRONG TO
SEVERE STORMS.
THE DEEP LOW PRESSURE SYSTEM OVER THE CENTRAL PLAINS/MID MS VALLEY
WILL REMAIN NEARLY STATIONARY THIS PERIOD. A SERIES OF UPPER LEVEL
DISTURBANCES WILL ROTATE AROUND THIS LOW SIMILAR TO SPOKES AROUND
TEH CENTER OF A WHEEL. AS A DISTURBANCE CROSSES CENTRAL NC AND
INTERACTS WITH THE WARM MOIST UNSTABLE AIR MASS IN PLACE...EXPECT
SCATTERED TO NUMEROUS SHOWERS AND STORMS TO OCCUR. BASED ON MODEL
TIMING 9WHICH WILL LIKELY CHANGE OR ADJUST IN LATER MODEL
RUNS)...APPEARS FIRST ROUND OF SHOWERS AND STORMS WILL CROSS THE
REGION TUESDAY AFTERNOON WITH ANOTHER ROUND LATE TUESDAY NIGHT. WIND
PROFILES TUESDAY AFTERNOON ARE SUPPORTIVE OF STRONG UPDRAFTS WITH
LOW LEVEL HELICITY VALUES IN THE 150-300 M2/S2 RANGE LATE TUESDAY
INTO TUESDAY NIGHT. IN ADDITION...STRONG LIFT EXPECTED THROUGH TEH
COLUMN AS CENTRAL NC WILL BE IN THE RIGHT ENTRANCE REGION OF A 100-
110KT UPPER JET. THUS...POTENTIAL FOR A FEW SEVERE STORMS TUESDAY
AFTERNOON AND TUESDAY NIGHT WITH A FEW TORNADOES PROBABLE.
ALSO...POTENTIAL FOR STORMS TO REPEAT ACROSS THE SAME AREA. WITH
PRECIP WATER VALUES 1.5-1.75 INCHES PROJECTED...THIS SUGGEST THAT
THE HEAVY SHOWERS AND STORMS WILL BE CAPABLE FOR PRODUCING HEAVY
RAIN...LEADING TO FLOODING IN URBANIZED AREAS (AND EVENTUALLY SOME
RIVER FLOODING).
MAX TEMPS TUESDAY DEPENDENT UPON WHETHER THE SFC BOUNDARY LIFTS
ENTIRELY INTO VA OR LAGS ALONG OUR NORTHERN COUNTIES. APPEARS TO BE
ENOUGH OF A SLY FETCH JUST ABOVE THE SFC TO PUSH THE BOUNDARY NWD SO
HAVE LEANED TOWARD THE WARMER GUIDANCE FOR TUESDAY. MAX TEMPS MID
70S FAR NORTH-NW TO THE LOWER 80S SOUTH. MIN TEMPS TUESDAY NIGHT LOW
60S FAR NORTH-NW TO MID-UPPER 60S ELSEWHERE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 240 PM MONDAY...
FOR WED/WED NIGHT: LOOKS LIKE ANOTHER ROUND OF STRONG TO POSSIBLY
SEVERE STORMS LATE WED INTO WED NIGHT... ALTHOUGH THE DEGREE OF
THREAT WILL DEPEND LARGELY ON THE EXTENT OF CLOUDINESS WED MORNING
AND ITS IMPACT ON INSTABILITY HEADING THROUGH THE DAY. THE POTENT
MID LEVEL VORTEX WILL WOBBLE SLOWLY EASTWARD ACROSS THE UPPER
MIDWEST/WRN GREAT LAKES AS AN 80 KT MID LEVEL JET STREAK TRACKS UP
ALONG THE SRN/CENTRAL APPALACHIANS/FOOTHILLS... WITH UPPER
DIVERGENCE MAXIMIZING OVER THE ERN HALF OF NC LATE IN THE DAY.
PROVIDED THAT TUE NIGHT`S CONVECTIVE DEBRIS CLOUDS CAN CLEAR OUT OF
CENTRAL/ERN NC BY MID AFTERNOON AND ALLOW FOR SOME INSOLATION... WE
MAY ACHIEVE MUCAPE VALUES OF 1000-2000 J/KG COINCIDENT WITH DEEP
LAYER SHEAR OF 30-40 KTS. FORECAST HODOGRAPHS REMAIN BROADLY CURVED
WED WITH 0-3 KM HELICITY OVER 200 M2/S2... EHI EXCEEDING 2.5... AND
VGP OVER 0.3 M/S2... SUGGESTING ROTATING UPDRAFTS ARE A GOOD BET
GIVEN ENOUGH ASCENT VIA DYNAMIC AND THERMODYNAMIC PROCESSES. WILL
CONTINUE TO HIGHLIGHT THE SEVERE THREAT FOR WED AFTERNOON/EVENING
FOR ALL OF CENTRAL NC... FOR THE POSSIBILITY OF DAMAGING WIND-
PRODUCING BOWING SEGMENTS AND/OR SUPERCELLS PRODUCING A FEW
TORNADOES. EQUALLY AS CONCERNING IS THE THREAT FOR REPEATED BOUTS OF
TRAINING CONVECTIVE BANDS/CLUSTERS GENERATING EXTENDED PERIODS OF
HEAVY RAINFALL... AS MUCH AS 2-4 INCHES FROM TUE THROUGH WED NIGHT.
LARGE SCALE MODELS AGREE ON THIS PATTERN WITH THE GREATEST TOTALS
FROM THE NC MOUNTAINS THROUGH THE PIEDMONT... AND GIVEN PROJECTIONS
OF PW VALUES WELL OVER 200% OF NORMAL FROM LATE TUE LASTING THROUGH
WED NIGHT AND A DEEP WARM LAYER OVER 3.5 KM FAVORING WARM RAIN
PROCESSES... IT IS NEARLY CERTAIN THAT THE FLOODING THREAT WILL
EXTEND THROUGH WED NIGHT. CONSIDERABLE STREET FLOODING... SWOLLEN
CREEKS... AND SIGNIFICANT RISES ON MAINSTEM RIVERS ARE ALL POSSIBLE.
MAX TEMPS ARE A TOUGH CALL GIVEN THE UNCERTAINTY AS TO HOW MUCH
SUNSHINE WE`LL GET... BUT MODEL TRENDS AND THICKNESSES WITH STRONG
WARM AIR ADVECTION SUPPORT RAISING HIGHS A BIT TO 77-84. THE COLD
FRONT IS LIKELY TO SLOW TO A CRAWL AS IT EASES EASTWARD INTO THE FAR
WRN PIEDMONT WED NIGHT AS IT BECOMES PARALLEL TO THE STEERING FLOW
AND LOSES FORWARD MOMENTUM. THE LOSS OF HEATING AND THE WANING
DYNAMIC FORCING AS THE MID LEVEL FLOW FLATTENS SHOULD RESULT IN A
DECREASING SEVERE THREAT OVERNIGHT. THE STRONG LOW LEVEL MOISTURE
TRANSPORT WILL SLOWLY SHIFT EASTWARD INTO ERN NC LATE... AS SHOULD
THE GREATEST PW VALUES... LIKELY RESULTING IN A DIMINISHING FLOODING
THREAT LATE (ALTHOUGH STREET AND RIVER FLOODING MAY BE ONGOING).
WITH WARM SW FLOW AND PLENTIFUL CLOUD COVER... EXPECT MILD LOWS OF
60-67.
FOR THU/THU NIGHT: WHAT APPEARS TO BE DEPICTED AS A PREFRONTAL
TROUGH SHIFTS INTO THE COASTAL AREAS OF NC BY THU MORNING WITH THE
PRIMARY FRONT STILL HANGING BACK OVER WRN NC WHILE BECOMING
INCREASINGLY DIFFUSE. THE LOW LEVEL MOISTURE TRANSPORT AND PW REMAIN
ELEVATED OVER ERN NC... NECESSITATING A CONTINUED GOOD CHANCE OF
SHOWERS AND ISOLATED STORMS IN THE COASTAL PLAIN THROUGH THU...
WHILE THE NW CWA SHOULD SEE GENERALLY DRY WEATHER AND FAIR SKIES.
SHORTWAVE ENERGY RIDING NE OVER THE SRN GREAT LAKES/ST LAWRENCE
VALLEY SHOULD HELP PUSH THE SURFACE FRONT TO OUR SE BY THU NIGHT...
LEADING TO DIMINISHED RAIN CHANCES AS LOW LEVEL FLOW BECOMES MORE
WESTERLY OR WNW. HIGHS 75-82. LOWS FROM 49 NW TO 57 EAST. -GIH
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 305 AM MONDAY...
GIVEN THE MID LEVEL TROUGH AXIS IS EXPECTED TO REMAIN TO OUR WEST
UNTIL LATE SATURDAY/SATURDAY NIGHT WITH THE SURFACE FRONT EXPECTED
TO LINGER NEAR THE COAST THROUGH SATURDAY MORNING... EXPECT WE COULD
SEE SOME MORE SHOWERS AND EVEN SOME STORMS... WITH THE HIGHEST
PROBABILITIES ACROSS OUR FAR EAST/SOUTHEASTERN AREAS. DRY WEATHER IS
EXPECTED TO RETURN FOR SUNDAY. EXPECT HIGH TEMPS WILL BE IN THE 70S
TO NEAR 80 EAST ON THURSDAY... WITH HIGH TEMPS GENERALLY AROUND 70
TO THE MID 70S FOR FRIDAY THROUGH SUNDAY. LOW TEMPS WILL BE IN THE
40S AND 50S FOR THIS TIME FRAME.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 150 PM MONDAY...
UNSETTLED WEATHER WILL PERSIST THROUGH MIDWEEK... AS A POWERFUL
STORM SYSTEM HOLDS OVER THE CENTRAL STATES... WITH A WARM FRONT
EXTENDING EASTWARD THROUGH OUR REGION AND A MOIST LOW LEVEL FLOW
FROM THE SOUTHWEST GRADUALLY DEVELOPING OVER NC. AVIATION CONDITIONS
NOW VARYING FROM MVFR TO LOW-END VFR ARE EXPECTED TO PERSIST THROUGH
THIS AFTERNOON... WITH VFR CONDITIONS DOMINATING AT MOST SITES AFTER
20Z. CONDITIONS ARE LIKELY TO WORSEN BY EARLY THIS EVENING WITH A
GOOD CHANCE OF MVFR VSBYS IN SHOWERS AND STORMS. THIS IS LIKELY TO
BE FOLLOWED BY LOWERING CIGS TO IFR/LIFR LATE TONIGHT AS LOW STRATUS
FORMS OVER THE AREA. WHILE WE`RE UNLIKELY TO MEET LLWS CRITERIA
TONIGHT... WINDS THAT ARE FROM THE SE AT 5-10 KTS AT THE SURFACE
WILL VEER WITH HEIGHT TO SW AT 25-30 KTS AROUND 1500 FT AGL LATE
TONIGHT... WHICH MAY CAUSE DIFFICULTY IN HANDLING SOME AIRCRAFT. THE
THREAT OF PATCHY SHOWERS AND A STORM OR TWO WILL LINGER OVERNIGHT...
THEN MORE ORGANIZED AND STRONGER STORMS ARE EXPECTED TO FORM TUE
AFTERNOON... AS CIGS RISE TO MVFR TOWARD THE END OF THE TAF VALID
PERIOD... WITH SURFACE WINDS BECOMING SOUTHERLY OR SOUTHWESTERLY AND
INCREASING TO AROUND 15 KTS AS THE WARM FRONTAL ZONE SURGES NORTH OF
CENTRAL NC.
LOOKING BEYOND 18Z TUE... AVIATION INTERESTS SHOULD CLOSELY MONITOR
THE LATEST CONDITIONS TUE AFTERNOON THROUGH WED EVENING... AS THERE
IS A HEIGHTENED RISK OF STRONG TO SEVERE STORMS... ANY OF WHICH
COULD PRODUCE DANGEROUS AVIATION WEATHER. OTHERWISE... EXPECT MAINLY
MVFR CIGS THROUGH THE REST OF TUE AFTERNOON WITH GUSTY WINDS FROM
THE SW AND A PEAK IN STORM COVERAGE INTO TUE EVENING. IFR/LIFR
CIGS/VSBYS LIKELY TO RESUME AFTER 05Z WED... IMPROVING SLOWLY TO
MVFR BY 16Z WED WITH ANOTHER PEAK IN STORM COVERAGE EXPECTED LATE
WED AFTERNOON INTO THE EVENING. EXPECT A COLD FRONT TO SHIFT INTO
CENTRAL NC AND WEAKEN EARLY THU... RESULTING IN PROBABLE VFR
CONDITIONS AT GSO/INT AND MVFR/IFR HOLDING AT RDU/RWI/FAY THU.
CONTINUED UNSETTLED FRI ESPECIALLY IN EASTERN TERMINALS WITH
POSSIBLE MVFR CONDITIONS PERSISTING. VFR CONDITIONS EXPECTED SAT.
-GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...HARTFIELD
LONG TERM...BSD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
150 PM EDT MON APR 28 2014
.SYNOPSIS...A STALLED SURFACE BOUNDARY ACROSS CENTRAL NC WILL LIFT
NORTHWARD AS A WARM FRONT THIS AFTERNOON. A WARM...MOIST AND
UNSTABLE AIR MASS WILL RESIDE OVER CENTRAL NC TONIGHT THROUGH
WEDNESDAY NIGHT. A SERIES OF UPPER LEVEL DISTURBANCES WILL INTERACT
WITH THIS AIR MASS TRIGGERING SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1040 AM MONDAY...
A WEAK COLD FRONT AND SHALLOW STABLE AIRMASS SETTLED SOUTH THROUGH
THE AREAS OVERNIGHT...MAKING IT ESSENTIALLY TO THE SC BORDER AND
CREATING A RATHER LARGE GRADIENT IN TEMPS AND DEWPOINTS. THE PARENT
SURFACE HIGH BEHIND THE FRONT WILL CONTINUE TO SUPPLY A
NORTHEASTERLY WIND TODAY...BUT WITH CLEARING ALREADY OCCURRING ACROSS
THE SOUTHERN PIEDMONT AND A SOUTHWESTERLY WIND AT 925MB...THE BOUNDARY
SHOULD MIX BACK TO THE NORTH TODAY. HIGHS FOR TODAY ARE TOUGH GIVEN
THE VARYING CLOUD COVER AND SLOWLY VEERING SURFACE WINDS ACROSS THE
SOUTH. TEMPS OVER PORTION OF SC HAVE ALREADY JUMPED INTO THE MID
AND UPPER 70S. ACROSS THE NORTH THE AMOUNT OF SUN IS A BIT MORE
UNCERTAIN...WITH ADDITIONAL CLOUD COVER MOVING EAST ACROSS THE BLUE
RIDGE. ADJUSTMENTS TO TEMP TRENDS YIELDS MID 60S NORTH TO LOWER 80S
SOUTH.
REGARDING CONVECTION... THE MAIN LIMITING FACTOR IS THE SHORTWAVE
RIDGE OVERHEAD...BUT FORECAST SOUNDINGS SUGGEST HEATING AND
MOISTURE RECOVER WILL BE ABLE TO OVERCOME THE MID-LEVEL CAP. THE
LATEST RAP RUNS SHOW AN INSTABILITY AXIS ON THE ORDER OF 500-1000
J/KG MLCAPE NOSING NORTH ACROSS THE SOUTHERN PIEDMONT BY
MIDDAY...WITH DESTABILIZATION TO THE EAST CROSS THE SANDHILLS AND
SOUTHERN COASTAL PLAIN WITH TIME. THE SEEMS TO MESH WELL WITH
SATELLITE TRENDS AND DEWPOINTS RECOVERING INTO THE MID TO UPPER
60S....SO AREAS SOUTH OF HWY 64 LOOK TO MOST FAVORABLE FOR
CONVECTION THIS AFTERNOON. BULK SHEAR WILL BE STRONGER TO THE
NORTH...BUT GUIDANCE SUGGESTS AS MUCH AS 30KT WHICH COULD SUPPORT
SOME MULTICELL CLUSTERS WITH A GENERAL MOTION FROM WEST TO EAST.
THE MAIN THREAT FROM STORMS WILL BE DAMAGING WINDS...THOUGH STORMS
FARTHER NORTH IN THE VICINITY OF THE RETREATING SURFACE BOUNDARY AND
BACKED SURFACE WINDS WILL ENCOUNTER GREATER SHEAR AND HAVE A BETTER
CHANCE OF ROTATING. AGAIN...THE THREAT OF SEVERE WEATHER IS
CONDITIONED UPON DEVELOPMENT OF STORMS...WHICH SHOULD BE MOSTLY
SCATTERED IN NATURE. -SMITH
TONIGHT...SFC FRONT PROJECTED TO BE STALLED ACROSS THE NORTHERN
COUNTIES. WEAK CONVERGENCE ALONG THIS FEATURE WILL MAINTAIN A
THREAT FOR SCATTERED SHOWERS THROUGH THE NIGHT. EXPECT SHOWERS TO BE
MORE ISOLATED ACROSS THE SOUTH. RATHER MILD TONIGHT WITH MIN TEMPS
NO LOWER THAN THE MID 60S ACROSS THE SOUTH...TRENDING TO THE UPPER
50S/NEAR 60 SOUTH.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
TUESDAY AND TUESDAY NIGHT...ACTIVE WEATHER PATTERN APPEARS LIKELY
ACROSS CENTRAL NC WITH A CHANCE FOR MORE THAN ONE ROUND OF STRONG TO
SEVERE STORMS.
THE DEEP LOW PRESSURE SYSTEM OVER THE CENTRAL PLAINS/MID MS VALLEY
WILL REMAIN NEARLY STATIONARY THIS PERIOD. A SERIES OF UPPER LEVEL
DISTURBANCES WILL ROTATE AROUND THIS LOW SIMILAR TO SPOKES AROUND
TEH CENTER OF A WHEEL. AS A DISTURBANCE CROSSES CENTRAL NC AND
INTERACTS WITH THE WARM MOIST UNSTABLE AIR MASS IN PLACE...EXPECT
SCATTERED TO NUMEROUS SHOWERS AND STORMS TO OCCUR. BASED ON MODEL
TIMING 9WHICH WILL LIKELY CHANGE OR ADJUST IN LATER MODEL
RUNS)...APPEARS FIRST ROUND OF SHOWERS AND STORMS WILL CROSS THE
REGION TUESDAY AFTERNOON WITH ANOTHER ROUND LATE TUESDAY NIGHT. WIND
PROFILES TUESDAY AFTERNOON ARE SUPPORTIVE OF STRONG UPDRAFTS WITH
LOW LEVEL HELICITY VALUES IN THE 150-300 M2/S2 RANGE LATE TUESDAY
INTO TUESDAY NIGHT. IN ADDITION...STRONG LIFT EXPECTED THROUGH TEH
COLUMN AS CENTRAL NC WILL BE IN THE RIGHT ENTRANCE REGION OF A 100-
110KT UPPER JET. THUS...POTENTIAL FOR A FEW SEVERE STORMS TUESDAY
AFTERNOON AND TUESDAY NIGHT WITH A FEW TORNADOES PROBABLE.
ALSO...POTENTIAL FOR STORMS TO REPEAT ACROSS THE SAME AREA. WITH
PRECIP WATER VALUES 1.5-1.75 INCHES PROJECTED...THIS SUGGEST THAT
THE HEAVY SHOWERS AND STORMS WILL BE CAPABLE FOR PRODUCING HEAVY
RAIN...LEADING TO FLOODING IN URBANIZED AREAS (AND EVENTUALLY SOME
RIVER FLOODING).
MAX TEMPS TUESDAY DEPENDENT UPON WHETHER THE SFC BOUNDARY LIFTS
ENTIRELY INTO VA OR LAGS ALONG OUR NORTHERN COUNTIES. APPEARS TO BE
ENOUGH OF A SLY FETCH JUST ABOVE THE SFC TO PUSH THE BOUNDARY NWD SO
HAVE LEANED TOWARD THE WARMER GUIDANCE FOR TUESDAY. MAX TEMPS MID
70S FAR NORTH-NW TO THE LOWER 80S SOUTH. MIN TEMPS TUESDAY NIGHT LOW
60S FAR NORTH-NW TO MID-UPPER 60S ELSEWHERE.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 305 AM MONDAY...
WEDNESDAY AND WEDNESDAY NIGHT: THE DEEP MID LEVEL LOW AND SURFACE
LOW ARE EXPECTED TO LINGER ACROSS THE UPPER MIDWEST AND GREAT LAKES
REGION ON WEDNESDAY AND WEDNESDAY NIGHT WITH THE SYSTEM QUITE
WRAPPED UP AND OCCLUDED. THIS WILL RESULT IN STRONG SOUTH-
SOUTHWESTERLY MID LEVEL FLOW ACROSS OUR REGION ALONG WITH A SLOW
APPROACHING COLD FRONT. EXPECT THE HEAVIEST AND MORE WIDESPREAD
PRECIP WILL BE ACROSS WESTERN PORTIONS OF THE AREA ON WEDNESDAY.
THIS MAY LEAD TO A DECENT DIFFERENTIAL HEATING BOUNDARY SETTING UP
ACROSS THE REGION. GIVEN DEEP LAYER SHEAR VALUES ARE EXPECTED TO BE
AROUND 35 TO 50 KTS WEDNESDAY AFTERNOON INTO THE EVENING... WITH THE
POTENTIAL FOR UPWARDS OF 1000 TO 2000 J/KG OF MLCAPE FOR LOCATIONS
THAT WARM UP NICELY AND SEE A BIT LESS RAIN... EXPECT WE WILL HAVE A
THREAT FOR SEVERE STORMS. IF WE INDEED SEE A BOUNDARY SET UP OR
LINGERING BOUNDARY FROM EARLIER THEN WE COULD SEE AN INCREASE RISK
FOR TORNADOES... AS 0-1 KM SRH VALUES ARE EXPECTED TO BE IN THE 150
TO 400 M2/S2 RANGE WITH RIGHT LOOPING HODOGRAPHS. GIVEN THE
IMPRESSIVE DEEP LAYER SHEAR AND POSSIBLE MODERATE INSTABILITY...
SUPERCELLS WILL BE POSSIBLE... WITH DAMAGING WIND AND LARGE HAIL AS
WELL. IN ADDITION... WITH PW VALUES EXPECTED TO BE AROUND 1.5 INCHES
(WELL ABOVE NORMAL FOR THIS TIME OF YEAR) EXPECT THE SHOWERS AND
STORMS WILL PRODUCE HEAVY RAIN. THIS COUPLED WITH THE SLOW MOVING
FRONT WILL POSE A RISK FOR FLASH FLOODING AND RIVER FLOODING...
ESPECIALLY ACROSS THE WESTERN PIEDMONT (WHERE SEVERAL DAYS WORTH OF
MODERATE TO HEAVY RAIN MAY LEAD TO 3 TO 4+ INCHES OF RAINFALL). THE
MAIN AXIS OF SHOWERS AND STORMS WILL BEGIN TO SLOWLY SHIFT EASTWARD
BY EARLY THURSDAY MORNING AS THE SURFACE COLD FRONT BEGINS TO PUSH
THROUGH THE AREA... WITH THE MAIN AREAS OF SHOWERS AND STORMS FROM
GENERALLY RALEIGH EASTWARD BY MIDNIGHT THURSDAY.
TEMPS ON WEDNESDAY WILL BE TRICKY AND DRIVEN BY CLOUDS AND PRECIP.
FOR NOW WILL SHOW HIGHS IN THE WEST (WHERE THE MOST RAIN IS
EXPECTED) IN AROUND THE MID 70S (CLOSER TO THE COOL SIDE OF
GUIDANCE) TO THE LOWER 80S SE. LOWS THURSDAY MORNING SHOULD REMAIN
MILD WITH AT LEAST CONTINUED LINGERING LOW LEVEL CLOUD COVER.
THUS... WILL GO WITH LOWS IN THE LOWER 60S WEST TO UPPER 60S EAST.
THURSDAY THROUGH SUNDAY: THE COLD FRONT WILL SLOWLY MOVE ACROSS
CENTRAL NC WEDNESDAY NIGHT/THURSDAY MORNING... WITH A FINAL
SECONDARY PUSH NOT COMING THROUGH UNTIL THURSDAY NIGHT/FRIDAY
MORNING. HOWEVER... WITH MID LEVEL DRY AIR FILTERING INTO THE
WESTERN/NORTHWESTERN HALF OF THE CWA ON THURSDAY EXPECT WE WILL
BEGIN TO DRY OUT A BIT IN PIEDMONT ON THURSDAY INTO THURSDAY NIGHT.
GIVEN THE MID LEVEL TROUGH AXIS IS EXPECTED TO REMAIN TO OUR WEST
UNTIL LATE SATURDAY/SATURDAY NIGHT WITH THE SURFACE FRONT EXPECTED
TO LINGER NEAR THE COAST THROUGH SATURDAY MORNING... EXPECT WE COULD
SEE SOME MORE SHOWERS AND EVEN SOME STORMS... WITH THE HIGHEST
PROBABILITIES ACROSS OUR FAR EAST/SOUTHEASTERN AREAS. DRY WEATHER IS
EXPECTED TO RETURN FOR SUNDAY. EXPECT HIGH TEMPS WILL BE IN THE 70S
TO NEAR 80 EAST ON THURSDAY... WITH HIGH TEMPS GENERALLY AROUND 70
TO THE MID 70S FOR FRIDAY THROUGH SUNDAY. LOW TEMPS WILL BE IN THE
40S AND 50S FOR THIS TIME FRAME.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 150 PM MONDAY...
UNSETTLED WEATHER WILL PERSIST THROUGH MIDWEEK... AS A POWERFUL
STORM SYSTEM HOLDS OVER THE CENTRAL STATES... WITH A WARM FRONT
EXTENDING EASTWARD THROUGH OUR REGION AND A MOIST LOW LEVEL FLOW
FROM THE SOUTHWEST GRADUALLY DEVELOPING OVER NC. AVIATION CONDITIONS
NOW VARYING FROM MVFR TO LOW-END VFR ARE EXPECTED TO PERSIST THROUGH
THIS AFTERNOON... WITH VFR CONDITIONS DOMINATING AT MOST SITES AFTER
20Z. CONDITIONS ARE LIKELY TO WORSEN BY EARLY THIS EVENING WITH A
GOOD CHANCE OF MVFR VSBYS IN SHOWERS AND STORMS. THIS IS LIKELY TO
BE FOLLOWED BY LOWERING CIGS TO IFR/LIFR LATE TONIGHT AS LOW STRATUS
FORMS OVER THE AREA. WHILE WE`RE UNLIKELY TO MEET LLWS CRITERIA
TONIGHT... WINDS THAT ARE FROM THE SE AT 5-10 KTS AT THE SURFACE
WILL VEER WITH HEIGHT TO SW AT 25-30 KTS AROUND 1500 FT AGL LATE
TONIGHT... WHICH MAY CAUSE DIFFICULTY IN HANDLING SOME AIRCRAFT. THE
THREAT OF PATCHY SHOWERS AND A STORM OR TWO WILL LINGER OVERNIGHT...
THEN MORE ORGANIZED AND STRONGER STORMS ARE EXPECTED TO FORM TUE
AFTERNOON... AS CIGS RISE TO MVFR TOWARD THE END OF THE TAF VALID
PERIOD... WITH SURFACE WINDS BECOMING SOUTHERLY OR SOUTHWESTERLY AND
INCREASING TO AROUND 15 KTS AS THE WARM FRONTAL ZONE SURGES NORTH OF
CENTRAL NC.
LOOKING BEYOND 18Z TUE... AVIATION INTERESTS SHOULD CLOSELY MONITOR
THE LATEST CONDITIONS TUE AFTERNOON THROUGH WED EVENING... AS THERE
IS A HEIGHTENED RISK OF STRONG TO SEVERE STORMS... ANY OF WHICH
COULD PRODUCE DANGEROUS AVIATION WEATHER. OTHERWISE... EXPECT MAINLY
MVFR CIGS THROUGH THE REST OF TUE AFTERNOON WITH GUSTY WINDS FROM
THE SW AND A PEAK IN STORM COVERAGE INTO TUE EVENING. IFR/LIFR
CIGS/VSBYS LIKELY TO RESUME AFTER 05Z WED... IMPROVING SLOWLY TO
MVFR BY 16Z WED WITH ANOTHER PEAK IN STORM COVERAGE EXPECTED LATE
WED AFTERNOON INTO THE EVENING. EXPECT A COLD FRONT TO SHIFT INTO
CENTRAL NC AND WEAKEN EARLY THU... RESULTING IN PROBABLE VFR
CONDITIONS AT GSO/INT AND MVFR/IFR HOLDING AT RDU/RWI/FAY THU.
CONTINUED UNSETTLED FRI ESPECIALLY IN EASTERN TERMINALS WITH
POSSIBLE MVFR CONDITIONS PERSISTING. VFR CONDITIONS EXPECTED SAT.
-GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1159 AM EDT MON APR 28 2014
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST UNITED STATES WILL CONTINUE TO
BRING MILD SOUTHERLY WINDS TO THE REGION. SHOWERS AND THUNDERSTORMS
WILL INCREASE IN COVERAGE TODAY THROUGH WEDNESDAY AS A TROUGH OF LOW
PRESSURE APPROACHES FROM THE WEST. ANOTHER QUICK ROUND OF RAIN IS
POSSIBLE LATE FRIDAY AND SATURDAY BEFORE CONDITIONS DRY OUT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 AM MONDAY...EXPECT LOCALIZED CONVECTION MAINLY ALONG
LINGERING FRONT BASICALLY RUNNING ACROSS NORTH CAROLINA FROM WEST
TO EAST ALONG NORTHERN TIER COUNTIES OF FORECAST AREA. MOIST
SOUTHERLY FLOW OVER MOST OF CWA WITH TEMPS UP AROUND 80 AND
DEWPOINTS IN THE MID 60S RUNNING UP AGAINST NORTHERLY WINDS WITH
TEMPS CLOSER TO 70 AND DEWPOINTS IN THE 50S JUST NORTH OF LOCAL
FORECAST AREA. THIS BOUNDARY WILL REMAIN THE FOCUS FOR CONVECTION
THIS AFTERNOON BUT ALSO EXPECT CONVECTIVE DEVELOPMENT ALONG SEA
BREEZE CONVERGENT BOUNDARY. THE SEA BREEZE WILL BE SLOW TO MOVE
INLAND AS IT RUNS UP AGAINST A DECENT W-SW COMPONENT TO THE FLOW
ABOVE THE SURFACE. RUC AND HRRR SHOW SHWRS POPPING BETWEEN 1 AND 2
PM. THE STEERING FLOW WILL PUSH ANY SHWRS/TSTMS THAT DEVELOP
TOWARD THE COAST BUT THE MORE STABILIZED AIR BEHIND SEA BREEZE
SHOULD KEEP THE IMMEDIATE COAST FREE OF STORMS. KEPT POPS VERY
CLOSE TO PREVIOUS FORECAST WITH ONLY MINOR ADJUSTMENTS AND WILL
UPDATE AS NEEDED ONCE CONVECTION FLARES. SHOULD SEE CLOUDS BLANKET
MUCH OF THE AREA THROUGH THIS AFTERNOON AS CONVECTIVE DEBRIS
CLOUDS WILL BE STEERED EAST AND HIGH CLOUDS WILL SPILL OVER THE
MID TO UPPER RIDGE INTO LOCAL AREA
THE STALLED BOUNDARY WILL BEGIN TO LIFT SLOWLY NORTH THROUGH THE
DAY AND THIS MAY HELP TO SHIFT CONVECTION NORTH EVENTUALLY.
WITH MID TO UPPER RIDGE OVER THE SOUTHEAST AND MORE IN THE WAY OF
SUBSIDENCE THAN LIFT...DO NOT EXPECT MUCH IN THE WAY OF STRONG
THUNDERSTORMS IN WARM AIR MASS TO THE SOUTH OF FRONT. ALSO EXPECT LOCALIZED
CONVECTION TO SHUT DOWN AS HEATING OF THE DAY CUTS OFF AFTER
SUNSET. THEREFORE WILL TAPER OFF POPS AFTER SUNSET LEAVING BEST CHC
TO THE NORTH ALONG BOUNDARY. SHOULD BE A RELATIVELY QUIET NIGHT
WITH ABUNDANT CLOUD COVER AND LOWS WELL ABOVE CLIMO...RUNNING IN
THE MID 60S IN A WARM AND HUMID AIRMASS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...ALL EYES WILL BE ON THE SYSTEM NOW MOVING ACROSS THE
CENTRAL U.S AS IT MAKES ITS MOVE ON THE EAST COAST. THE GFS...WHICH
I HAVE BEEN LEANING TOWARD FOR A FEW CYCLES NOW REMAINS CONSISTENT
WITH THE BEST LIFT AND MOISTURE COUPLING LATE WEDNESDAY AND INTO THE
MORNING HOURS THURSDAY. I HAVE INCREASED POPS BASICALLY ACROSS THE
BOARD MORE SO FOR THE LATER PERIODS. SPC CONTINUES TO HAVE THE AREA
IN A SLIGHT RISK FOR BOTH DAYS. TEMPERATURE GUIDANCE IS IN GOOD
AGREEMENT OUTSIDE OF DAYTIME HIGHS FOR WEDNESDAY WITH THE NAM/MET
NUMBERS ONCE AGAIN COOLER. INHERITED BLEND WILL SUFFICE FOR NOW.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...THE FOCUS FOR THE EXTENDED BEGINS TO SHIFT FROM THE
LONG ADVERTISED SYSTEM THAT IS CURRENTLY PLODDING ACROSS THE CENTRAL
U.S TO A SECONDARY WAVE LATE IN THE PERIOD. THE LATEST MEDIUM RANGE
GUIDANCE CONTINUES TO ADVERTISE A WET SCENARIO MAINLY ALONG THE
COAST. I HAVE TWEAKED THE POPS FOR SATURDAY TO REPRESENT MORE OF A
COASTAL SYSTEM ALTHOUGH THERE IS STILL PLENTY OF TIME FOR THIS TO
CHANGE. POPS REMAIN IN THE FORECAST FOR THURSDAY AND FRIDAY MOSTLY
VIA THE LOWER CONFIDENCE IN THE PROGRESS OF THE INITIAL SYSTEM. NO
CHANGES TO THE TEMPERATURE FORECAST.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 12..SOME LIGHT SHOWERS ARE MOVING THROUGH THE EASTERN PORTION
OF THE REGION. PRECIP IS FALLING MAINLY OUT OF MID CLOUD. VFR THIS
MORNING. MODELS ARE IN REASONABLY GOOD AGREEMENT IN INTRODUCING
CONVECTION THIS AFTERNOON OVER THE NORTHERN HALF OF THE
CWA...ASSOCIATED WITH A WARM FRONT AND RETURN MOISTURE FLOW.
MOISTURE IS FAIRLY DEEP...AND IF THE CONVECTIVE TEMP IS
REACHED...THERE SHOULD BE FAIRLY GOOD COVERAGE OF SHOWERS. MOST OF
THE ACTIVITY WILL END THIS EVENING AS THE WARM FRONT WAVES NORTH.
WITH THE SOUTHWESTERLY FLOW TONIGHT...IFR STRATUS IS A REASONABLE
BET.
EXTENDED OUTLOOK...ISOLATED AFTERNOON/EVENING SHOWERS AND
THUNDERSTORMS POSSIBLE THROUGH WEDNESDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 AM MONDAY...QUIET MARINE CONDITIONS OVERALL THROUGH
THIS AFTERNOON. HIGH PRESSURE REMAINS OVER THE AREA WITH
LINGERING BOUNDARY LIFTING NORTH OF THE THE WATERS. GRADIENT
REMAINS LIGHT WITH SOUTH TO SOUTHEAST FLOW REMAINING UNDER 10 KT
THROUGH THE MORNING HOURS WITH SEAS 2 FT OR LESS. MAY SEE A FEW
LINGERING SHOWERS MAKE IT OVER THE WATERS JUST ALONG NORTHERN
PORTION OF LOCAL WATERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...A SOUTH TO OCCASIONALLY SOUTHEAST FLOW WILL
PREVAIL THROUGH THE PERIOD. THE STRONGEST WINDS SHOULD OCCUR LATE
WEDNESDAY WHEN A RANGE OF 20-25 KNOTS. FOR THE MOST PART A RANGE OF
15-20 KNOTS SHOULD BE FAIRLY PERSISTENT BEFORE THIS. SEAS WILL
GRADUALLY BUILD FROM AN INITIAL RANGE OF 1-3 FEET TO 3-5 AND
POSSIBLY 4-6 FEET BY THE END OF SECOND HALF OF THE PERIOD.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...THE MAIN ISSUE FOR THE MARINE COMMUNITY WILL BE
THE TIMING OF THE WIND SHIFT WITH THE FRONT ASSOCIATED WITH THE MAIN
INITIAL SYSTEM. THIS SHOULD OCCUR LATE THURSDAY/EARLY FRIDAY
ALTHOUGH CONFIDENCE IS LOW DUE TO THE SLOW NATURE OF THIS SYSTEM.
PRECEDING THIS...EXPECT A SOUTHWEST FLOW OF 15-20 KNOTS. FOR FRIDAY
EXPECT A LIGHTER AND MORE VARIABLE FLOW. SIGNIFICANT SEAS WILL BE
HOVERING AT OR JUST BELOW SMALL CRAFT CRITERIA THURSDAY 3-5 FEET
DROPPING SLIGHTLY FRIDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1040 AM EDT MON APR 28 2014
.SYNOPSIS...A STALLED SURFACE BOUNDARY ACROSS CENTRAL NC WILL LIFT
NORTHWARD AS A WARM FRONT THIS AFTERNOON. A WARM...MOIST AND
UNSTABLE AIR MASS WILL RESIDE OVER CENTRAL NC TONIGHT THROUGH
WEDNESDAY NIGHT. A SERIES OF UPPER LEVEL DISTURBANCES WILL INTERACT
WITH THIS AIR MASS TRIGGERING SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1040 AM MONDAY...
A WEAK COLD FRONT AND SHALLOW STABLE AIRMASS SETTLED SOUTH THROUGH
THE AREAS OVERNIGHT...MAKING IT ESSENTIALLY TO THE SC BORDER AND
CREATING A RATHER LARGE GRADIENT IN TEMPS AND DEWPOINTS. THE PARENT
SURFACE HIGH BEHIND THE FRONT WILL CONTINUE TO SUPPLY A
NORTHEASTERLY WIND TODAY...BUT WITH CLEARING ALREADY OCCURRING ACROSS
THE SOUTHERN PIEDMONT AND A SOUTHWESTERLY WIND AT 925MB...THE BOUNDARY
SHOULD MIX BACK TO THE NORTH TODAY. HIGHS FOR TODAY ARE TOUGH GIVEN
THE VARYING CLOUD COVER AND SLOWLY VEERING SURFACE WINDS ACROSS THE
SOUTH. TEMPS OVER PORTION OF SC HAVE ALREADY JUMPED INTO THE MID
AND UPPER 70S. ACROSS THE NORTH THE AMOUNT OF SUN IS A BIT MORE
UNCERTAIN...WITH ADDITIONAL CLOUD COVER MOVING EAST ACROSS THE BLUE
RIDGE. ADJUSTMENTS TO TEMP TRENDS YIELDS MID 60S NORTH TO LOWER 80S
SOUTH.
REGARDING CONVECTION... THE MAIN LIMITING FACTOR IS THE SHORTWAVE
RIDGE OVERHEAD...BUT FORECAST SOUNDINGS SUGGEST HEATING AND
MOISTURE RECOVER WILL BE ABLE TO OVERCOME THE MID-LEVEL CAP. THE
LATEST RAP RUNS SHOW AN INSTABILITY AXIS ON THE ORDER OF 500-1000
J/KG MLCAPE NOSING NORTH ACROSS THE SOUTHERN PIEDMONT BY
MIDDAY...WITH DESTABILIZATION TO THE EAST CROSS THE SANDHILLS AND
SOUTHERN COASTAL PLAIN WITH TIME. THE SEEMS TO MESH WELL WITH
SATELLITE TRENDS AND DEWPOINTS RECOVERING INTO THE MID TO UPPER
60S....SO AREAS SOUTH OF HWY 64 LOOK TO MOST FAVORABLE FOR
CONVECTION THIS AFTERNOON. BULK SHEAR WILL BE STRONGER TO THE
NORTH...BUT GUIDANCE SUGGESTS AS MUCH AS 30KT WHICH COULD SUPPORT
SOME MULTICELL CLUSTERS WITH A GENERAL MOTION FROM WEST TO EAST.
THE MAIN THREAT FROM STORMS WILL BE DAMAGING WINDS...THOUGH STORMS
FARTHER NORTH IN THE VICINITY OF THE RETREATING SURFACE BOUNDARY AND
BACKED SURFACE WINDS WILL ENCOUNTER GREATER SHEAR AND HAVE A BETTER
CHANCE OF ROTATING. AGAIN...THE THREAT OF SEVERE WEATHER IS
CONDITIONED UPON DEVELOPMENT OF STORMS...WHICH SHOULD BE MOSTLY
SCATTERED IN NATURE. -SMITH
TONIGHT...SFC FRONT PROJECTED TO BE STALLED ACROSS THE NORTHERN
COUNTIES. WEAK CONVERGENCE ALONG THIS FEATURE WILL MAINTAIN A
THREAT FOR SCATTERED SHOWERS THROUGH THE NIGHT. EXPECT SHOWERS TO BE
MORE ISOLATED ACROSS THE SOUTH. RATHER MILD TONIGHT WITH MIN TEMPS
NO LOWER THAN THE MID 60S ACROSS THE SOUTH...TRENDING TO THE UPPER
50S/NEAR 60 SOUTH.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
TUESDAY AND TUESDAY NIGHT...ACTIVE WEATHER PATTERN APPEARS LIKELY
ACROSS CENTRAL NC WITH A CHANCE FOR MORE THAN ONE ROUND OF STRONG TO
SEVERE STORMS.
THE DEEP LOW PRESSURE SYSTEM OVER THE CENTRAL PLAINS/MID MS VALLEY
WILL REMAIN NEARLY STATIONARY THIS PERIOD. A SERIES OF UPPER LEVEL
DISTURBANCES WILL ROTATE AROUND THIS LOW SIMILAR TO SPOKES AROUND
TEH CENTER OF A WHEEL. AS A DISTURBANCE CROSSES CENTRAL NC AND
INTERACTS WITH THE WARM MOIST UNSTABLE AIR MASS IN PLACE...EXPECT
SCATTERED TO NUMEROUS SHOWERS AND STORMS TO OCCUR. BASED ON MODEL
TIMING 9WHICH WILL LIKELY CHANGE OR ADJUST IN LATER MODEL
RUNS)...APPEARS FIRST ROUND OF SHOWERS AND STORMS WILL CROSS THE
REGION TUESDAY AFTERNOON WITH ANOTHER ROUND LATE TUESDAY NIGHT. WIND
PROFILES TUESDAY AFTERNOON ARE SUPPORTIVE OF STRONG UPDRAFTS WITH
LOW LEVEL HELICITY VALUES IN THE 150-300 M2/S2 RANGE LATE TUESDAY
INTO TUESDAY NIGHT. IN ADDITION...STRONG LIFT EXPECTED THROUGH TEH
COLUMN AS CENTRAL NC WILL BE IN THE RIGHT ENTRANCE REGION OF A 100-
110KT UPPER JET. THUS...POTENTIAL FOR A FEW SEVERE STORMS TUESDAY
AFTERNOON AND TUESDAY NIGHT WITH A FEW TORNADOES PROBABLE.
ALSO...POTENTIAL FOR STORMS TO REPEAT ACROSS THE SAME AREA. WITH
PRECIP WATER VALUES 1.5-1.75 INCHES PROJECTED...THIS SUGGEST THAT
THE HEAVY SHOWERS AND STORMS WILL BE CAPABLE FOR PRODUCING HEAVY
RAIN...LEADING TO FLOODING IN URBANIZED AREAS (AND EVENTUALLY SOME
RIVER FLOODING).
MAX TEMPS TUESDAY DEPENDENT UPON WHETHER THE SFC BOUNDARY LIFTS
ENTIRELY INTO VA OR LAGS ALONG OUR NORTHERN COUNTIES. APPEARS TO BE
ENOUGH OF A SLY FETCH JUST ABOVE THE SFC TO PUSH THE BOUNDARY NWD SO
HAVE LEANED TOWARD THE WARMER GUIDANCE FOR TUESDAY. MAX TEMPS MID
70S FAR NORTH-NW TO THE LOWER 80S SOUTH. MIN TEMPS TUESDAY NIGHT LOW
60S FAR NORTH-NW TO MID-UPPER 60S ELSEWHERE.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 305 AM MONDAY...
WEDNESDAY AND WEDNESDAY NIGHT: THE DEEP MID LEVEL LOW AND SURFACE
LOW ARE EXPECTED TO LINGER ACROSS THE UPPER MIDWEST AND GREAT LAKES
REGION ON WEDNESDAY AND WEDNESDAY NIGHT WITH THE SYSTEM QUITE
WRAPPED UP AND OCCLUDED. THIS WILL RESULT IN STRONG SOUTH-
SOUTHWESTERLY MID LEVEL FLOW ACROSS OUR REGION ALONG WITH A SLOW
APPROACHING COLD FRONT. EXPECT THE HEAVIEST AND MORE WIDESPREAD
PRECIP WILL BE ACROSS WESTERN PORTIONS OF THE AREA ON WEDNESDAY.
THIS MAY LEAD TO A DECENT DIFFERENTIAL HEATING BOUNDARY SETTING UP
ACROSS THE REGION. GIVEN DEEP LAYER SHEAR VALUES ARE EXPECTED TO BE
AROUND 35 TO 50 KTS WEDNESDAY AFTERNOON INTO THE EVENING... WITH THE
POTENTIAL FOR UPWARDS OF 1000 TO 2000 J/KG OF MLCAPE FOR LOCATIONS
THAT WARM UP NICELY AND SEE A BIT LESS RAIN... EXPECT WE WILL HAVE A
THREAT FOR SEVERE STORMS. IF WE INDEED SEE A BOUNDARY SET UP OR
LINGERING BOUNDARY FROM EARLIER THEN WE COULD SEE AN INCREASE RISK
FOR TORNADOES... AS 0-1 KM SRH VALUES ARE EXPECTED TO BE IN THE 150
TO 400 M2/S2 RANGE WITH RIGHT LOOPING HODOGRAPHS. GIVEN THE
IMPRESSIVE DEEP LAYER SHEAR AND POSSIBLE MODERATE INSTABILITY...
SUPERCELLS WILL BE POSSIBLE... WITH DAMAGING WIND AND LARGE HAIL AS
WELL. IN ADDITION... WITH PW VALUES EXPECTED TO BE AROUND 1.5 INCHES
(WELL ABOVE NORMAL FOR THIS TIME OF YEAR) EXPECT THE SHOWERS AND
STORMS WILL PRODUCE HEAVY RAIN. THIS COUPLED WITH THE SLOW MOVING
FRONT WILL POSE A RISK FOR FLASH FLOODING AND RIVER FLOODING...
ESPECIALLY ACROSS THE WESTERN PIEDMONT (WHERE SEVERAL DAYS WORTH OF
MODERATE TO HEAVY RAIN MAY LEAD TO 3 TO 4+ INCHES OF RAINFALL). THE
MAIN AXIS OF SHOWERS AND STORMS WILL BEGIN TO SLOWLY SHIFT EASTWARD
BY EARLY THURSDAY MORNING AS THE SURFACE COLD FRONT BEGINS TO PUSH
THROUGH THE AREA... WITH THE MAIN AREAS OF SHOWERS AND STORMS FROM
GENERALLY RALEIGH EASTWARD BY MIDNIGHT THURSDAY.
TEMPS ON WEDNESDAY WILL BE TRICKY AND DRIVEN BY CLOUDS AND PRECIP.
FOR NOW WILL SHOW HIGHS IN THE WEST (WHERE THE MOST RAIN IS
EXPECTED) IN AROUND THE MID 70S (CLOSER TO THE COOL SIDE OF
GUIDANCE) TO THE LOWER 80S SE. LOWS THURSDAY MORNING SHOULD REMAIN
MILD WITH AT LEAST CONTINUED LINGERING LOW LEVEL CLOUD COVER.
THUS... WILL GO WITH LOWS IN THE LOWER 60S WEST TO UPPER 60S EAST.
THURSDAY THROUGH SUNDAY: THE COLD FRONT WILL SLOWLY MOVE ACROSS
CENTRAL NC WEDNESDAY NIGHT/THURSDAY MORNING... WITH A FINAL
SECONDARY PUSH NOT COMING THROUGH UNTIL THURSDAY NIGHT/FRIDAY
MORNING. HOWEVER... WITH MID LEVEL DRY AIR FILTERING INTO THE
WESTERN/NORTHWESTERN HALF OF THE CWA ON THURSDAY EXPECT WE WILL
BEGIN TO DRY OUT A BIT IN PIEDMONT ON THURSDAY INTO THURSDAY NIGHT.
GIVEN THE MID LEVEL TROUGH AXIS IS EXPECTED TO REMAIN TO OUR WEST
UNTIL LATE SATURDAY/SATURDAY NIGHT WITH THE SURFACE FRONT EXPECTED
TO LINGER NEAR THE COAST THROUGH SATURDAY MORNING... EXPECT WE COULD
SEE SOME MORE SHOWERS AND EVEN SOME STORMS... WITH THE HIGHEST
PROBABILITIES ACROSS OUR FAR EAST/SOUTHEASTERN AREAS. DRY WEATHER IS
EXPECTED TO RETURN FOR SUNDAY. EXPECT HIGH TEMPS WILL BE IN THE 70S
TO NEAR 80 EAST ON THURSDAY... WITH HIGH TEMPS GENERALLY AROUND 70
TO THE MID 70S FOR FRIDAY THROUGH SUNDAY. LOW TEMPS WILL BE IN THE
40S AND 50S FOR THIS TIME FRAME.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 140 AM MONDAY...
VFR CONDITIONS EXPECTED TO LINGER THROUGH THE OVERNIGHT INTO EARLY
THIS MORNING AS LOW STRATUS HAS BEEN SLOW TO DEVELOP NE OF OUR
REGION. WILL CONTINUE TO MONITOR BUT THE GFS MODEL MAY BE OVERDONE
IN ITS DEPICTION OF LOW CLOUDS (MVFR/IFR CEILINGS) OVER A LARGE PART
OF CENTRAL NC THROUGH 11Z.
THE APPROACH OF AN UPPER LEVEL DISTURBANCE FROM THE SW AND A STALLED
SURFACE BOUNDARY OVER CENTRAL NC WILL CAUSE AREAS OF SHOWERS TO
DEVELOP BY 13Z IN THE WESTERN AND SOUTHERN PIEDMONT...LIFTING NE
INTO THE COASTAL PLAIN AND NE PIEDMONT BY MID AFTERNOON. THESE
SHOWERS WILL CAUSE PERIODS OF LOW END VFR/HIGH END MVFR CEILINGS AND
VISIBILITY. WHILE BEST INSTABILITY EXPECTED TO RESIDE OVER THE
SOUTHERN PIEDMONT...BEST SHEAR FOR SUSTAINED UPDRAFTS WILL BE
LOCATED FARTHER NORTH NEAR THE VA BORDER. STILL A SLIGHT-SMALL
CHANCE FOR A FEW THUNDERSTORMS THIS AFTERNOON ACROSS CENTRAL NC BUT
CONFIDENCE OF THUNDER OCCURRING WITHIN 10 SM OF A TAF SITE LOW AT
THIS TIME. THUS WILL REFRAIN FROM MENTIONING THUNDER IN THE TAF
SITES WITH THE 06Z TAF PACKAGE.
A PERIOD OF UNSETTLED WEATHER IS ANTICIPATED THROUGH EARLY THURSDAY
AS A DEEP LOW PRESSURE SYSTEM TO OUR WEST EDGES SLOWLY EAST THROUGH
MID WEEK. THIS WEATHER SYSTEM WILL SPREAD AREAS OF SHOWERS AND
THUNDERSTORMS (ASSOCIATED MVFR-IFR CONDITIONS) ACROSS CENTRAL NC
TUESDAY THROUGH EARLY THURSDAY. STRONG TO SEVERE STORMS APPEAR
HIGHLY PROBABLE TUESDAY AFTERNOON THROUGH WEDNESDAY NIGHT.
IMPROVING AVIATION CONDITIONS ANTICIPATED BY LATE IN THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
936 PM CDT TUE APR 29 2014
.UPDATE...
ISSUED AT 935 PM CDT TUE APR 29 2014
MAIN ADJUSTMENT TO THE FORECAST WAS TO INCREASE AREAL COVERAGE OF
PATCHY FOG IN THE WEST. THE 30.00Z NAM SHOWS INCREASING BOUNDARY
LAYER RELATIVE HUMIDITY VALUES ACROSS WESTERN NORTH DAKOTA...WITH
VALUES APPROACHING 100 PERCENT OVERNIGHT. THE LATEST RAP AND HRRR
ALSO SUGGEST THERE COULD BE VISIBILITY RESTRICTIONS IN PARTS OF
THE WEST...SO FELT CONFIDENT ENOUGH TO EXPAND FOG TO THE NORTHWEST
DESPITE THE WIND.
UPDATE ISSUED AT 651 PM CDT TUE APR 29 2014
MADE ONLY MINOR ADJUSTMENTS TO THE FORECAST TO CAPTURE THE LATEST
CLOUD TRENDS. THE 29.18Z NAM STILL SUPPORTS FOG DEVELOPMENT IN THE
WEST LATE TONIGHT / EARLY WEDNESDAY MORNING THOUGH IT MAY NEED TO
BE EXPANDED FARTHER NORTHWEST. WILL CONSIDER THAT FOR THE NEXT
UPDATE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 338 PM CDT TUE APR 29 2014
WEDGE OF SUBSIDING DRY AIR ON CLEARING CLOUDS ACROSS MOST OF THE
REGION. SNOW JUST ABOUT OVER SOUTHWEST AS PER BOWMAN RADAR. GUSTY
NORTHWEST WINDS ARE MIXING WELL AND TEMPS HAVE WARMED INTO THE
LOWER 50S CENTRAL AND EAST...WHILE THE SNOW COVERED AREAS
SOUTHWEST ARE IN THE MIDDLE 30S. ADDED SOME PATCHY FOG WEST OVER
SNOW COVERED AREAS WEST TONIGHT...ALTHOUGH WINDS WILL BE ELEVATED
ABOVE GENERAL FOG CRITERIA...THE ABUNDANT COOLED AND MOIST
BOUNDARY LAYER MAY BE ENOUGH TO OVERCOME THE MIXING. OTHERWISE
MOSTLY CLEAR THIS EVENING WITH SOME INCREASING CLOUDS AS THE UPPER
LOW DUMBELLS BACK INTO THE EASTERN DAKOTAS AND BRING SOME LIGHT
RAIN AFTER SUNRISE WEDNESDAY IN THE JAMES RIVER VALLEY. BUFKIT
SOUNDINGS SUGGEST JUST SUB ADVISORY WINDS OF 25 TO 35 MPH
WEDNESDAY AS THE SURFACE FLOW WRAPS UP OVER THE GREAT LAKES.
HIGHS SHOULD BE IN THE LOWER 50S CENTRAL AND EAST AND IN THE 40S
OVER THE SNOW COVERED AREAS WEDNESDAY. MOST OF THE SNOW MAY BE
GONE AFTER WEDNESDAY AS SAT PICS SHOW PRETTY RAPID MELT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 338 PM CDT TUE APR 29 2014
AN ACTIVE AND COOL WEATHER PATTERN WILL PERSIST FOR MUCH OF THE
LONG TERM PERIOD.
LARGE UPPER LEVEL LOW PRESSURE CENTERED OVER THE WESTERN GREAT
LAKES/UPPER MISSISSIPPI VALLEY REGION WILL CONTINUE TO SPIN
THROUGH WEDNESDAY NIGHT...THEN WILL FINALLY LIFT NORTHEAST
THURSDAY INTO FRIDAY INTO SOUTHEASTERN CANADA. FOR THE NORTHERN
PLAINS...CYCLONIC FLOW ALOFT WILL TRANSITION TO A NORTHWESTERLY
FLOW ALOFT THURSDAY ONCE THE LOW LIFTS OUT...THEN QUASI-ZONAL LATE
IN THE WEEKEND INTO THE EARLY PORTIONS OF THE FOLLOWING WORK WEEK
AS BROAD RIDGING DEVELOPS ACROSS THE UNITED STATES.
THE UPPER LOW WOBBLES/RETROGRADES SLIGHTLY WEST ON WEDNESDAY...
ALLOWING FOR WRAP AROUND MOISTURE TO ROTATE THROUGH THE EASTERN
DAKOTAS. CHANCES FOR PRECIPITATION ACROSS EASTERN NORTH DAKOTA
DECREASE WEDNESDAY NIGHT INTO THURSDAY AS THE UPPER LOW ONCE
AGAIN MOVES FARTHER EAST.
DRY CONDITIONS OVERNIGHT WEDNESDAY THROUGH THURSDAY MORNING AS A
SUBTLE S/WV RIDGE PASSES THROUGH THE AREA.
AS OUR FLOW ALOFT BECOMES MORE NORTHWEST THURSDAY
AFTERNOON...SEVERAL EMBEDDED WAVES WILL TRACK FROM NORTHWEST TO
SOUTHEAST THROUGH THE NORTHERN PLAINS LATER IN THE DAY
THURSDAY...THROUGH THURSDAY NIGHT...AND INTO FRIDAY...EACH
GENERATING A CHANCE OF RAIN OR SNOW (DEPENDING ON THE THERMAL
PROFILE AND SFC TEMPERATURES). AT THIS TIME MUCH OF THE
PRECIPITATION IS EXPECTED TO FALL AS RAIN.
UPPER LEVEL JET MOVES OVER THE REGION THIS COMING WEEKEND...AND
WILL RESULT IN A CONTINUED UNSETTLED PATTERN THAT LOOKS TO
CONTINUE INTO EARLY NEXT WEEK...WITH CHANCES FOR PRECIPITATION
EACH DAY. WITH THE DEVELOPMENT OF THE BROAD RIDGE...TEMPERATURES
SHOULD MODERATE A BIT...WITH HIGHS IN THE 50S/LOW 60S VERSUS MID
40S AND MID 50S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 651 PM CDT TUE APR 29 2014
ALL TAF SITES HAVE BECOME VFR...THOUGH A BRIEF MVFR CEILING IS
POSSIBLE OVER THE NEXT HOUR OR TWO AT KDIK. PATCHY FOG IS POSSIBLE
TONIGHT...ESPECIALLY ACROSS WESTERN NORTH DAKOTA...BUT WAS NOT
CONFIDENT ENOUGH TO ADD TO ANY TERMINALS JUST YET. CLOUDS
SPINNING AROUND AN UPPER LOW MAY DRIFT WESTWARD AGAIN POTENTIALLY
IMPACTING KJMS...FOLLOWED BY KMOT AND KBIS. WINDS WILL DIMINISH
THIS EVENING...BUT INCREASE AGAIN WEDNESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CK
SHORT TERM...WAA
LONG TERM...NH
AVIATION...CK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
335 AM CDT MON APR 28 2014
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 335 AM CDT MON APR 28 2014
THE MAIN FORECAST FOCUS WILL BE CONTINUED PRECIP CHANCES TODAY AND
TONIGHT.
WATER VAPOR IMAGERY THIS MORNING SHOWS THE WELL-DEFINED MID-LEVEL
CYCLONE OVER NEBRASKA...WITH MOISTURE ROTATING NORTHWARD ON THE
EASTERN FLANK OF THE SYSTEM...AND THE STRONGER CONVECTION WELL TO
THE SOUTHEAST. THE CURRENT BAND OF RAIN CONTINUES TO LIFT ACROSS
THE NORTHERN FORECAST AREA...WITH A BREAK TO THE SOUTH. BASED ON
SFC OBS...SOME MIXED PRECIP MAY BE OCCURRING FROM NC ND INTO THE
DVL BASIN.
MORE RAIN CONTINUES TO DEVELOP ACROSS S MN/IOWA WHICH WILL LIFT TO
THE NORTH AND WEST TODAY BRINGING WIDESPREAD RAINFALL TO THE
REGION...WITH ADDITIONAL AMOUNTS OVER AN INCH POSSIBLE. THE AREA
MOST LIKELY TO MISS OUT ON THE MAJORITY OF THE PRECIP WILL BE UP
TOWARDS THE LAKE OF THE WOODS AREA...WITH THE MODEL CONSENSUS
SUGGESTING THE HEAVIEST PRECIP FROM THE NORTHERN VALLEY SOUTHEAST
INTO CENTRAL MN. VERY DRY AIR IS STILL IN PLACE UP TOWARDS FLAG
ISLAND...SO THERE COULD BE A SHARP CUT-OFF IN PRECIP UP IN THIS
AREA...WITH EVEN SOME DRYING FROM THE NORTHEAST LATE IN THE DAY. SO
POP TRENDS WILL NEED TO BE FINE-TUNED IN LATER UPDATES. WINDS WILL BE
BRISK FROM THE EAST...WITH TEMPS NOT MOVING MUCH TODAY WITH THE
WIDESPREAD PRECIP AND CLOUDS.
BY TONIGHT...AN UPPER JET/SHORTWAVE WILL NOSE INTO THE OHIO
VALLEY...SHUNTING THE BETTER MOISTURE EASTWARD. AT THE SAME
TIME...DRY AIR WILL WORK IN FROM THE NORTHEAST. PRECIP SHOULD END
TO THE NORTH WITH SOME LIGHT PRECIP REMAINING FARTHER SOUTH. AS
TEMPS COOL...PRECIP COULD MIX WITH OR CHANGE TO SNOW...WITH
PERHAPS SOME LIGHT ACCUMULATIONS IN AREAS.
TUESDAY LOOKS TO BE DRY OVER MUCH OF THE AREA WITH NORTHERLY
FLOW. THE POSSIBLE EXCEPTION COULD BE ALONG THE SD BORDER INTO WC
MN CLOSER TO THE LOW. WITH SOME SUN...TEMPS COULD CREEP UP TOWARDS
50...ALTHOUGH WINDS WILL REMAIN ON THE STRONG SIDE WITH COLD ADVECTION.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 335 AM CDT MON APR 28 2014
AS THE STACKED LOW PRESSURE SYSTEM SLOWLY PUSHES TOWARDS THE GREAT
LAKES TUES NIGHT/WEDNESDAY AND SHORTWAVE ENERGY ROTATES AROUND THE
CIRCULATION...PRECIP CHANCES WILL INCREASE FROM THE WEST. BY THIS
TIME...THE BETTER LOW-LEVEL MOISTURE TRANSPORT WILL BE WELL EAST...SO
TOTALS WOULD BE LIGHT. THE GFS IS A BIT WETTER AND BRINGS THE PRECIP
FARTHER WEST...WHILE THE ECMWF KEEPS MOST OF THE PRECIP IN MN. IT
MAY BE JUST COLD ENOUGH FOR SOME SNOW TUES NIGHT INTO
WEDNESDAY...BUT ACCUMULATIONS WOULD BE LIGHT. WITH THE UPPER PATTERN
CHANGING LITTLE...WEDNESDAY WILL BE ANOTHER COOL DAY WITH HIGHS IN
THE 40S AND A TIGHT SFC GRADIENT KEEPING WINDS QUITE BREEZY FROM THE
NORTH.
FOR THURSDAY THROUGH SUNDAY...EXPECT THE CONTINUATION OF TEMPS BELOW
NORMAL ALONG WITH PERIODIC CHANCES FOR RAIN SHOWERS. THERE COULD
EVEN BE SOME SNOW MIXING IN AT TIMES OVERNIGHT...BUT OVERALL ANY
PRECIP SHOULD REMAIN LIQUID. ANY PRECIP SHOULD ALSO BE LIGHT...WITH
DEEPER MOISTURE WELL TO OUR SOUTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1140 PM CDT SUN APR 27 2014
THE FIRST BATCH OF RAIN IS MOVING NORTHWARD ACROSS THE REGION.
EXPECT A BRIEF BREAK IN ACTIVITY SOMETIME DURING THE OVERNIGHT
AND/OR EARLY MORNING HOURS. A SECOND BATCH OF RAIN WILL THEN EXPAND
INTO A MAJORITY OF THE REGION SOMETIME AFTER SUNRISE MONDAY MORNING.
ATTEMPTED TO ADD THIS DETAIL TO THE FORECAST. CIGS WILL CONTINUE TO
BE TRICKY AS MOST GUIDANCE IS TOO LOW (BECAUSE OF THE LOW LEVEL
EASTERLY FLOW FROM A DRY AIRMASS). RAP GUIDANCE APPEARS TO HAVE THE
BEST IDEA THAT CURRENT CONDITIONS WILL PREVAIL THROUGH THE
PERIOD...WITH POSSIBLE LOWER CIGS AS PRECIP RATES INCREASE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...MAKOWSKI
LONG TERM...DK/MAKOWSKI
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1140 PM CDT SUN APR 27 2014
.UPDATE...
ISSUED AT 933 PM CDT SUN APR 27 2014
FORECAST IS UNFOLDING AS EXPECTED. THE ONLY UPDATE WILL BE TO
INDICATE A BRIEF BREAK IN ACTIVITY WITH 30% POPS. THE REGION WILL
REMAIN WITHIN THE TROWAL (WHICH WILL GRADUALLY LIFT NORTH
OVERNIGHT). WE KNOW THAT RAIN WILL OCCUR WITHIN THIS FEATURE...AND
ALL AREAS WILL RECEIVE RAINFALL. THE HARD PART IS ATTEMPTING TO
FORECAST EXACTLY WHEN AND WHERE WAVES ROTATING AROUND THE MAIN
UPPER LOW WILL INFLUENCE AREAS WITHIN THE TROWAL. THE HRRR DID A
GOOD JOB LAST NIGHT...AND WILL FOLLOW AS GUIDANCE FOR TONIGHT. THE
RAIN ACROSS THE SOUTHERN FA WILL LIFT NORTH OVERNIGHT...AND
ANTICIPATE A BREAK IN ACTIVITY ONCE THIS ACTIVITY MOVES TO THE
NORTH. ADJUSTED POPS FOR THIS THINKING. THE NEXT WAVE...OR AREA OF
FORCING...IS ASSOCIATED WITH THE ACTIVITY JUST ENTERING SOUTHERN
IOWA. THIS ACTIVITY SHOULD EXPAND TO THE NORTHWEST
OVERNIGHT...ENTERING WEST CENTRAL MINNESOTA 10Z-12Z...THEN
EXPANDING INTO MUCH OF THE FA AFTER 12Z MONDAY MORNING (CONTINUING
THROUGH MUCH OF THE DAY...STARTING TO DRY FROM THE NORTHEAST BY
LATE AFTERNOON).
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 343 PM CDT SUN APR 27 2014
CHALLENGES INCLUDE WINDS LATE THIS AFTERNOON AND EVENING AND THEN
PRECIP CHANCES/TYPE/AMOUNTS THROUGH THE REMAINDER OF THE FORECAST
PERIOD. WILL USE RAP/HRRR FOR THE NEXT 6 TO 12 HOURS AND THEN
TRANSITION TO A GLOBAL MODEL BLEND THEREAFTER AS GFS/NAM/ECMWF/
GEM ARE IN RELATIVELY GOOD AGREEMENT.
IN THE NEAR TERM...WILL LET WIND ADVISORY CONTINUE UNTIL 7 PM CDT.
MOST AREAS WON/T HIT CRITERIA...BUT FINALLY STARTING TO SEE SOME
MORE WIDESPREAD OBSERVATIONS AT OR ABOVE 30 MPH.
20 UTC WATER VAPOR LOOP SHOWS PRIMARY VORTICITY MAXIMA ACROSS
WESTERN KS WITH A STRONG SHORT-WAVE ROTATING OUT OF ITS BASE.
STRONG WARM AIR AND MOISTURE ADVECTION (PWATS TO ONE INCH) ALONG
THE 850 HPA SFC THIS EVENING AND OVERNIGHT...COMBINED WITH
DIVERGENT FLOW ALOFT WILL RESULT IN INCREASING SHOWERS MOVING FROM
SOUTH TO NORTH. ADDED THUNDER BACK INTO THE FORECAST ACROSS THE
SOUTH THIS EVENING WITH ISOLATED LIGHTNING STRIKES ALONG THE ND/SD
BORDER. INSTABILITY IS MINIMAL...BUT SPC MESOANALYSIS SHOWS A
COUPLE HUNDRED JOULES OF MOST UNSTABLE CAPE. THERMAL PROFILES WARM
ENOUGH TONIGHT FOR ALL RAIN...BUT COULD SEE A FEW FLAKES IN THE
MIX.
WILL LIFT CATEGORICAL POPS TO THE NORTH TONIGHT AND MONDAY. MONDAY
WILL BE CLOUDY AND COOL WITH PERIODS OF LIGHT TO MODERATE RAIN
SHOWERS. TEMPERATURES WILL RISE INTO THE UPPER 30S TO MID 40S WITH
PERSISTENT BREEZY EASTERLY WIND. 850 HPA TEMPERATURES BEGIN TO
FALL BELOW FREEZING MONDAY NIGHT WITH MOST OF THE COLUMN BELOW 0 C
BY TUESDAY MORNING EXCEPT THE NEAR SFC LAYER. PTYPE WILL DEPEND
HEAVILY ON SFC TEMPERATURES...BUT WITH FORECAST VALUES PLUS OR
MINUS A FEW DEGREES AROUND FREEZING MONDAY NIGHT...WILL KEEP A
RAIN/SNOW MIX IN THE WEATHER GRIDS. NOT REALLY EXPECTING MUCH
ACCUMULATION AS MOST SNOW THAT DOES FALL SHOULD MELT ON CONTACT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 343 PM CDT SUN APR 27 2014
STRONG DRYING WILL WORK ITS WAY SOUTH ON TUESDAY AS THE LOW
PRESSURE SYSTEM SCOOTS ACROSS IA INTO WI. SHOULD SEE A BREAK IN
PRECIP...ESPECIALLY FOR THE CENTRAL AND NORTHERN FORECAST AREA.
COULD EVEN SEE SOME PEAKS OF SUN. PTYPE SHOULD BE MOSTLY RAIN WITH
HIGHS RISING INTO THE MID TO UPPER 40S. WINDS WILL REMAIN BREEZY
AND SHIFT TO THE NORTH.
WRAP AROUND PRECIP WILL RETURN WEDNESDAY AS THE LOW WOBBLES ACROSS
WI WITH A GREATER CHANCE FOR A RAIN/SNOW MIX OR EVEN ALL SNOW AT
TIMES GIVEN A SATURATED SUB-FREEZING COLUMN. PTYPE WILL AGAIN
DEPEND ON SFC TEMPERATURES WITH MINIMAL ACCUMULATIONS. WHEN ALL IS
SAID AND DONE...LIQUID ACCUMULATIONS OVER THE 2 TO 3 DAY PERIOD
WILL BE 1 TO 2 INCHES WITH LOCALLY HIGHER AMOUNTS IN HEAVIER
SHOWERS OR THUNDERSTORMS. ANY SNOW ACCUMULATION SHOULD BE CONFINED
MAINLY TO THE HIGHER TERRAIN ON EITHER SIDE OF THE VALLEY BUT ONLY
AN INCH OR LESS.
UPPER LOW AND SURFACE LOW WILL REMAIN OVER THE GREAT LAKES WEDNESDAY
NIGHT INTO THURSDAY WITH NORTH WINDS AND SPOTTY RAIN SHOWERS ALONG
WITH CONTINUED WELL BELOW NORMAL TEMPERATURES. 12Z ECMWF/GFS ALL
INDICATE 500 MB TROUGH TO REMAIN IN PLACE WITH NEXT SHORT WAVE
DROPPING SOUTH INTO THE NRN PLAINS FRIDAY NIGHT-SATURDAY WITH
ANOTHER CHANCE OF SHOWERS. NO HEAVY RAINFALL THIS PERIOD BUT AT
LEAST A CHANCE FOR SHOWERS EACH DAY AND TEMPS REMAIN BELOW AVERAGE
INTO THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1140 PM CDT SUN APR 27 2014
THE FIRST BATCH OF RAIN IS MOVING NORTHWARD ACROSS THE REGION.
EXPECT A BRIEF BREAK IN ACTIVITY SOMETIME DURING THE OVERNIGHT
AND/OR EARLY MORNING HOURS. A SECOND BATCH OF RAIN WILL THEN EXPAND
INTO A MAJORITY OF THE REGION SOMETIME AFTER SUNRISE MONDAY MORNING.
ATTEMPTED TO ADD THIS DETAIL TO THE FORECAST. CIGS WILL CONTINUE TO
BE TRICKY AS MOST GUIDANCE IS TOO LOW (BECAUSE OF THE LOW LEVEL
EASTERLY FLOW FROM A DRY AIRMASS). RAP GUIDANCE APPEARS TO HAVE THE
BEST IDEA THAT CURRENT CONDITIONS WILL PREVAIL THROUGH THE
PERIOD...WITH POSSIBLE LOWER CIGS AS PRECIP RATES INCREASE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...ROGERS
LONG TERM...ROGERS/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
214 AM EDT MON APR 28 2014
.SYNOPSIS...
A WET AND STORMY PATTERN WILL SET UP ACROSS THE AREA MONDAY THROUGH
WEDNESDAY...FOLLOWED BY COOL AND DRIER HIGH PRESSURE BY THE END OF
THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 2 AM...SCATTERED SHOWERS ACROSS NC HAVE BEEN ON A GENERAL
DECREASING TREND OVER THE PAST COUPLE OF HOURS...SO HAVE GENERALLY
FEATURED GRADUALLY WANING POPS AS THE CURRENT ACTIVITY LIFTS ACROSS
THE FOOTHILLS AND PIEDMONT. HOWEVER...ADDITIONAL WARM SECTOR SHOWERS
AND EVEN A TS OR TWO HAVE BEEN INITIATING OVER THE TN VALLEY IN
REGION OF GENERAL WAA AND B.L. CONVERGENCE...SO SMALL POPS WILL BE
RETAINED ACROSS THE FAR WESTERN MTNS THROUGH THE OVERNIGHT.
DEWPOINTS IN THE 50S AND WIDESPREAD CIRRUS BLOW-OFF FROM TENN/MISS
VALLEY CONVECTIVE COMPLEX WILL HOLD MIN TEMPS ABOUT 10-15 DEGREES
ABOVE CLIMO THIS MORNING.
AS OF 1010 PM EDT SUNDAY...BLENDED POPS ARE WORKING WELL AS
SCATTERED LIGHT SHOWERS HAVE DEVELOPED OVER THE WESTERN ZONES...AND
A FEW STRONGER STORMS HAVE DEVELOPED NOT TOO FAR UPSTREAM OF THE
FORECAST AREA. POPS AND SKY COVER LOOK GOOD.
AT 735 PM EDT SUNDAY...BLENDED A POP DERIVED FROM LOCAL CONVECTIVE
ALLOWING MODELS AND THE OFFICIAL FORECAST TO GO WITH A SMALL AREA OF
HIGH CHANCE AND LIKELY POPS FROM THE UPSTATE INTO THE SRN AND
CENTRAL NC MTNS. THE 18 UTC NAM HAD A LITTLE BETTER ELEVATED CAPE
ACROSS THIS AREA AND THE HRRR AND WRF-ARW ARE INCREASES CONVECTIVE
COVERAGE OVER THIS AREA LATER TONIGHT. OTHERWISE...INCREASED SKY
COVER AND MADE SOME MINOR TWEAKS TO THE REST OF THE GRIDS.
AT 430 PM EDT SUNDAY...ADJUSTED SKY GRIDS TO ACCOUNT FOR ENCROACHING
HIGH CLOUDS AS WELL AS A CU DECK THAT IS DEVELOPING ACROSS NE
GA...THE SW NC MTNS AND THE WRN UPSTATE. SOME OF THE MESOSCALE
MODELS BRING ELEVATED CONVECTION ACROSS THE FORECAST AREA OVERNIGHT
AS THE LEADING EDGE OF THE ELEVATED MIXED LAYER WORKS IN FROM THE
WEST. I DON/T SEE MUCH MUCAPE ON THE 18 UTC NAM...SO THINK MOST OF
THE ACTIVITY WILL BE WEAK. I WON/T ADJUST THE OVERNIGHT GRIDS JUST
YET..BUT I NEED TO RAMP UP POPS WITH SUBSEQUENT UPDATES.
AT 200 PM EDT SUNDAY...A NEGATIVELY TILTED UPPER TROUGH WILL SLOWLY
PROGRESS ACROSS THE SOUTHERN APPALACHIANS AND GREAT LAKES TONIGHT...
WHILE A CLOSED UPPER LOW MOVES NE ACROSS THE GREAT PLAINS. THE RIDGE
AXIS MOVES EAST OF THE MOUNTAINS ON MONDAY...WHILE THE UPPER LOW
DRIFTS BACK SOUTH OVER THE PLAINS.
ISENTROPIC UPGLIDE WILL SPREAD ACROSS THE UPPER SAVANNAH RIVER
VALLEY AND SOUTHERN APPALACHIANS LATE THIS AFTERNOON AND THIS
EVENING. INSTABILITY SHOULD BECOME SUFFICIENT FOR CONVECTION TO FORM
BEFORE EVENING...HOWEVER NEITHER SHEAR NOR INSTABILITY APPEAR
IMPRESSIVE. A BACK DOOR COLD FRONT WILL SETTLE SOUTH ACROSS WESTERN
NC TONIGHT...REACHING THE SC BORDER EAST OF THE MOUNTAINS BY
DAYBREAK.
THE BOUNDARY WILL BECOME A FOCUS FOR CONVECTIVE ACTIVITY ON
MONDAY...WHEN BETTER SHEAR AND INSTABILITY WILL BE PRESENT. SPC HAS
OUR ENTIRE AREA IN A SLIGHT RISK FOR SEVERE WEATHER ON DAY
TWO...MENTIONING AN ENVIRONMENT FAVORABLE FOR SUPERCELLS. THE AREA
NORTH OF INTERSTATE 40 MAY REMAIN UNFAVORABLE FOR CONVECTION DURING
THE DAYLIGHT HOURS ON MONDAY...AS COOL NE FLOW PREVAILS BEHIND THE
FRONT...AND A CAP REMAINS AT AROUND 875 MB. WITH THE BEST GULF
INFLOW STILL WELL TO THE WEST...EXCESSIVE RAINFALL IS NOT
EXPECTED...HOWEVER INDIVIDUAL STORMS MAY PUT DOWN LOCALLY HEAVY
RAINFALL.
MINIMUM TEMPERATURES WILL BE WELL ABOVE NORMAL UNDER INCREASING
CLOUDS COVER AND THE UPPER RIDGE. HIGH TEMPERATURES ON MONDAY WILL
RUN SLIGHTLY ABOVE NORMAL...AS CLOUD COVERAGE OFFSETS THE INFLUENCE
OF THE UPPER RIDGE.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 235 PM SUNDAY...NOTHING IN THE NEW GUIDANCE TO CHANGE EARLIER
THINKING THAT WE ARE ON A COLLISION COURSE WITH A VERY WET AND VERY
STORMY PATTERN DURING THE LATE MONDAY TO WEDNESDAY TIME FRAME.
IMPORTANT DETAILS SUCH AS THE TIMING OF ENHANCED SEVERE THUNDERSTORM
THREATS...AND STORM TOTAL RAINFALL...STILL REMAIN IN DOUBT.
ONE INTERESTING TREND OR POINT OF CONCERN IS BROUGHT TO LIGHT IN THE
LATEST NAM MONDAY NIGHT AND EARLY TUESDAY MORNING. A WEDGE BOUNDARY
OF SORTS IS INDICATED EVEN FARTHER SOUTH THAN PREVIOUS RUNS...DOWN
CLOSER TO THE SC/NC BORDER. THE AIR MASS TO THE SOUTH OF THE
BOUNDARY MIGHT BE FAIRLY RICH WITH BUOYANCY. THE SREF HAS A VERY
HIGH PROBABILITY OF CAPE GREATER THAN 1000 J/KG LATE IN THE
DAY...AND EVEN THE GENERALLY MORE CONSERVATIVE GFS HAS CAPE IN THE
1000 - 1500 J/KG RANGE. SHEAR AND SRH WILL INCREASE STEADILY THROUGH
THE EVENING HOURS IN THE PRESENCE OF ADEQUATE BUOYANCY...THUS OUR
CHANCES FOR ORGANIZED SEVERE THUNDERSTORMS WILL ALSO INCREASE. AGREE
WITH THE EXPANSION OF THE DAY2 SLIGHT RISK FURTHER EAST IN THE NEW
OUTLOOK. IF THE WEST TO EAST ORIENTED BOUNDARY REMAINS IN THE
AREA...THIS COULD PROVIDE THE FOCUS FOR SEVERE STORMS AND TORNADIC
ACTIVITY SOMEWHERE IN THE CAROLINAS WELL INTO THE OVERNIGHT HOURS.
THERE IS ALSO THE CONCERN THAT SUPERCELLULAR CONVECTION MOVING IN
FROM GEORGIA DURING THE EVENING WILL GET A SHOT OF INCREASED SHEAR
AS IT INTERACTS WITH A BOUNDARY. AT THE SAME TIME...THE FRONTAL ZONE
OF HEAVIER RAIN WILL MOVE INTO THE MOUNTAINS.
CONFIDENCE IN THE TIMING OF ANY MESOSCALE CONVECTIVE SYSTEMS GOES
DOWN AFTER LATE MONDAY NIGHT...BUT WE WILL RETAIN A FAVORABLE
COMBINATION OF SHEAR AND INSTABILITY TO KEEP A THREAT OF SEVERE
STORMS THROUGH TUESDAY ACROSS MOST OF THE FCST AREA...WITH PERHAPS
THE EXCEPTION OF THE WRN NC MTNS...AND INTO WEDNESDAY EAST OF THE
MOUNTAINS. ONE MIGHT EXPECT A BIT OF A LULL OR RECHARGE PERIOD
TUESDAY MORNING...BEFORE MORE ORGANIZED SEVERE WEATHER AFFECTS THE
REGION TUESDAY AFTERNOON AND EVENING WITH DIURNAL ENHANCEMENT. CAPE
PROFILES SUGGEST THAT WE MIGHT HAVE A BIT LESS OF A CHANCE OF
SUPERCELLS AND THE LIKE...BECAUSE OF CONVECTIVE DEBRIS/
OVERTURNING...BUT STILL ENOUGH OF A TORNADO THREAT FOR CONTINUED
CONCERN BECAUSE OF THE SHEAR. ADDITIONAL DETAILS WILL HOPEFULLY COME
MORE INTO FOCUS WITH SUBSEQUENT FCST PACKAGES.
AT ANY RATE...PRECIP CHANCES RAMP UP STEADILY FROM THE WEST INTO THE
LIKELY TO CATEGORICAL RANGE MONDAY NIGHT AND INTO TUESDAY AND
TUESDAY NIGHT. THE LATEST QPF GUIDANCE FROM WPC IS VERY TROUBLESOME.
ON THE ONE HAND...ANOMALY GUIDANCE DOES NOT SHOW ANYTHING OVERLY
ALARMING WITH REGARD TO PRECIPITABLE WATER...BUT ON THE OTHER HAND
THE SLOW MOVING NATURE OF THE COLD FRONT WILL PERMIT WAVES OF
MODERATE TO HEAVY RAIN STARTING EARLY TUESDAY MORNING...AND
CONTINUING INTO WEDNESDAY. UNLESS THERE IS SOME CHANGE IN
THINKING... THE NEED FOR A FLOOD WATCH IS NEARLY A FOREGONE
CONCLUSION...BUT THE MAIN THREAT OF FLOODING DOES NOT RAMP UP UNTIL
DURING THE DAY ON TUESDAY BASED ON THE QPF BREAKDOWN. SINCE THIS IS
THE 4TH FCST PERIOD AND WE HAVE SOME TIME TO GAIN MORE CONFIDENCE...
WILL HOLD OFF ON A FLOOD WATCH FOR ONE MORE FCST CYCLE.
MODEL GUIDANCE SHOWS THE FRONT CROSSING THE FCST AREA WEDNESDAY
EVENING AND THAT SHOULD BRING AN END TO MOST OF THE PRECIP...WITH
SOME LINGERING SHOWERS POSSIBLE ON THE TN BORDER OVER THE NRN MTNS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1 PM SUNDAY...EXPANSIVE UPPER TROUGH WILL REMAIN OVER THE ERN
CONUS THROUGH THE MEDIUM RANGE...WITH THE FLOW EVENTUALLY FLATTENING
BY THE END OF NEXT WEEKEND. FAIRLY UNSETTLED CONDITIONS WILL CONTINUE
ACRS THE SOUTHEAST REGION UNTIL THAT TIME. FRONTAL BOUNDARY LAYS OUT
JUST OFFSHORE FRIDAY.
GFS/EC/GEM AGREE ON A SHORTWAVE ROUNDING THE LARGER SCALE TROUGH AND
BRINGING A WAVE OUT OF THE GULF OF MEXICO ALONG THE FRONT. THEY
DISAGREE HOWEVER ON THE TIMING OF THIS EVENT. 12Z GFS/GEM DEVELOP
ONLY A WEAK WAVE FRIDAY...AND HAVE A LOW IMPACT ON OUR CWFA WITH VERY
LITTLE QPF. ORIENTATION OF THE FRONT ON THE 00Z EC LEADS IT TO
DEVELOP A STRONGER WAVE AND BRING ANOTHER ROUND OF PRECIP TO THE
PIEDMONT FRIDAY NIGHT AND SATURDAY. GFS CONCURRENTLY DEVELOPS SHOWERS
IN THE MTNS AS IT BRINGS THE WAVE ACRS EARLY SATURDAY...WITH
ADDITIONAL NW FLOW PRECIP CONTINUING INTO EARLY SUNDAY. THIS IS A
PLAUSIBLE SCENARIO THOUGH IT IS THE ONLY MODEL SHOWING IT. QPF FROM
THIS ACTIVITY IS NOTABLE BUT NOT HIGH ENOUGH FOR CONCERN...SO IT WILL
BE MINIMALLY REFLECTED IN THE FCST. IN FACT...NCEP/CMC ENSEMBLES GIVE
LITTLE SUPPORT TO A WETTER EC-LIKE SOLUTION SO POPS WILL BE KEPT ON
THE LOW SIDE FOR THE POTENTIAL FRONTAL WAVE PRECIP...ALONG WITH QPF.
AFTER ABV NORMAL TEMPS THU...TEMPS RETURN TO AROUND NORMAL FRI INTO
SAT WITH CLOUD COVER. LOWS SUNDAY MRNG SHOULD BE A COUPLE CATEGORIES
BELOW NORMAL BUT TEMPS REBOUND SUNDAY UNDER CLEARER SKIES.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AT KCLT...THE FIRST 12 HOURS OR SO OF THE FORECAST IS RELATIVELY
STRAIGHT FORWARD...WITH PRIMARILY HIGH/MID-LEVEL CLOUDS EXPECTED
ALONG WITH SOUTH WINDS. HOWEVER...UNCERTAINTY INCREASES
SUBSTANTIALLY FROM AFTERNOON ONWARD. A WEAK BACK DOOR FRONT WILL
DROP SLOWLY SOUTH ACROSS THE PIEDMONT LATER THIS MORNING (WITH WINDS
TURNING TO THE E/NE NORTH OF THE FRONT) BEFORE STALLING AND
EVENTUALLY LIFTING NORTH...BUT IT IS VERY UNCERTAIN AS TO WHETHER
THIS WILL MAKE IT AS FAR SOUTH AS KCLT. CERTAINLY A CONSENSUS OF
FORECAST GUIDANCE WOULD KEEP THE FRONT NORTH OF THE TERMINAL...AND
WE HAVE SIDED WITH THIS CONSENSUS. WHEREVER THE FRONT SETS UP...IT
IS EXPECTED TO PROVIDE A FOCUS FOR THUNDERSTORM DEVELOPMENT THIS
AFTERNOON...AS THE ATMOSPHERE IS EXPECTED TO BECOME MODERATELY
UNSTABLE. HOWEVER...THE DEGREE OF COVERAGE AND TIMING OF THIS IS
STILL QUITE UNCERTAIN. FOR NOW...PROB30S HAVE BEEN INTRODUCED FOR
THE 18-20Z TIME FRAME...WITH A TEMPO THROUGH 00Z. TS CHANCES WILL
CONTINUE THROUGH THE END OF THE PERIOD.
ELSEWHERE...DESPITE INCREASING LOW LEVEL MOISTURE...EXTENSIVE HIGH
CLOUDS ASSOCIATED WITH MISS/TENN VALLEY CONVECTION IS EXPECTED TO
KEEP COVERAGE OF FOG LIMITED THIS MORNING (EXCEPT PERHAPS ACROSS THE
MOUNTAIN VALLEYS WEST OF KAVL)...BUT HAVE INCLUDED A PERIOD OF MVFR
FOG AT KAND. A BACKDOOR COLD FRONT IS EXPECTED TO PUSH THROUGH KHKY
AROUND SUNRISE...AND MVFR CIGS ARE EXPECTED TO DEVELOP THERE BY
MID-MORNING OR SO. OTHERWISE...THE PRIMARY FORECAST CHALLENGE IS
TIMING AND OVERALL COVERAGE OF THUNDERSTORMS LATER TODAY. CHANCES
SHOULD GRADUALLY INCREASE THROUGHOUT THE DAY...AND HAVE RESERVED
CATEGORICAL SHOWERS FOR VERY LATE THIS AFTERNOON AND THIS EVENING...
WITH VCTS FAVORED EARLIER IN THE PERIOD.
OUTLOOK...PERIODS OF NUMEROUS/WIDESPREAD SHOWERS AND THUNDERSTORMS
AND ASSOCIATED RESTRICTION ARE EXPECTED FROM EARLY TUESDAY THROUGH
AT LEAST WEDNESDAY. DRIER WEATHER IS ANTICIPATED FOR LATE WEEK INTO
THE WEEKEND.
CONFIDENCE TABLE...
06-12Z 12-18Z 18-24Z 00-06Z
KCLT HIGH 100% HIGH 93% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 93% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 98% HIGH 100% HIGH 98%
KHKY HIGH 100% MED 79% HIGH 85% HIGH 93%
KGMU HIGH 100% HIGH 93% HIGH 100% HIGH 100%
KAND HIGH 97% HIGH 94% 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...JAT/JDL/MCAVOY
SHORT TERM...PM
LONG TERM...WIMBERLEY
AVIATION...JDL
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1229 PM CDT MON APR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM CDT MON APR 28 2014
CURRENT WATER VAPOR IMAGERY SHOWS THE LOW IN THE MID LEVELS OF THE
ATMOSPHERE SPINNING AWAY RIGHT IN THE MIDDLE OF NEBRASKA...WITH THE
WELL ADVERTISED DRY SLOT ALOFT NOSING UP IN FRONT OF IT AND
ENCOMPASSING MUCH OF OUR FORECAST AREA. THE MOST PRONOUNCED DRYING
ALOFT IS ALONG THE I 29 CORRIDOR CURRENTLY. MODEL CONSENSUS IS GOOD
IN PROGGING THE LOW SLOWLY EASTWARD TOWARD SOUTHEAST IA BY VERY LATE
TONIGHT. THE SURFACE LOW FOLLOWS SUIT...AND IT LOOKS LIKE OUR ENTIRE
FORECAST AREA WILL BE PLACED NORTH OF THE WARM FRONT THROUGH TODAY
AND TONIGHT. THE BEST CHANCES FOR WIDESPREAD BENEFICIAL RAINFALL
TODAY WILL BE BEHIND THE INVERTED TROUGH WHICH WILL BE CONFINED TO
OUR FAR WESTERN ZONES APPROACHING CENTRAL SD. THE REST OF OUR AREA
WILL SEE LESS NUMEROUS SHOWERS AND RAINFALL. BUT THERE IS ENOUGH
ELEVATED INSTABILITY TO POP A THUNDERSTORM OR TWO ALMOST AT ANYTIME
THROUGHOUT THE ENTIRE DAY...ESPECIALLY WHEN A MICROSCALE AREA OF
WARM AIR ADVECTION DECIDES TO MOVE NORTHWARD WHICH THE MODELS CANNOT
HANDLE VERY WELL ON THAT SCALE. INTERESTINGLY...BOTH THE GFS AND GEM
PAINT A BROAD STRIPE OF DECENT QPF THIS AFTERNOON JUST NORTH OF THE
WARM FRONT FROM SIOUX CITY TO STORM LAKE. IN ADDITION...THE PAST FEW
RUNS OF THE HRRR ARE ALSO SHOWING THE POSSIBILITY OF DECENT
CONVECTION IN THOSE AREAS AGAIN DUE TO THE PROXIMITY OF THE WARM
FRONT JUST TO THE SOUTH. AT THIS TIME...IT LOOKS TOO STABLE FOR MUCH
IN THE WAY OF SEVERE WEATHER...AND ALSO THE WIND SHEAR IS NOT REAL
GREAT FROM SIOUX CITY TO STORM LAKE AS THE ENTIRE LOWEST 3
KILOMETERS HAS A WIND DIRECTION OUT OF THE EAST. ONE THING TO WATCH
FOR HOWEVER IS IF A ROGUE SEVERE STORM WHICH BLOWS UP FURTHER TO THE
SOUTHEAST NUDGES INTO THOSE AREAS BEFORE WEAKENING. TO THE
NORTH...KEPT THE COVERAGE OF POPS IN THE SCATTERED CATEGORY THIS
AFTERNOON ALONG THE I 29 CORRIDOR WHERE THE DRY SLOT ALOFT HAS THE
MOST IMPACT. BUT OTHER AREAS MAY START TO FILL IN MORE WITH RAINFALL
IN OUR FAR EAST AND INTO THE JAMES RIVER VALLEY FROM THE WEST AS
MOISTURE PROGS SATURATE UP BETTER ALOFT.
FEEL THERE IS NO NEED FOR A WIND ADVISORY TODAY AS SOUNDINGS ONLY
MIX TO ABOUT 925-900MB AREA WIDE. WINDS IN THAT LAYER ARE STOUT...
AVERAGING 30 TO 35 KNOTS...BUT USUALLY IT TAKES A LITTLE MORE THAN
THAT TO WARRANT A WIND ADVISORY IN OUR AREA...CLOSER TO 40 KNOTS.
HOWEVER TONIGHT ON THE BACK SIDE OF THE LOW...OUR FAR SOUTHWEST
ZONES MAY GET CLOSE TO ADVISORY CRITERIA AFTER MIDNIGHT. MUCH OF OUR
FORECAST AREA TONIGHT IS WELL PLACED IN THE UPPER LEFT QUADRANT OF
THE LOW TRACK TO RECEIVE PRECIP. THERE IS EVEN SOME WEAK TROWALING
IN THE 290-295K LAYER NUDGING INTO OUR AREA FROM THE EAST...AND
SATURATION LOOKS TO BE IN NO SHORT SUPPLY FROM THE SURFACE TO AROUND
500MB. IN THE EVENING...AGAIN THE I 29 CORRIDOR MAY NOT RECEIVE MUCH
RAIN...BUT PRECIP WILL FILL INTO THAT AREA OVERNIGHT. CONCERNING
TEMPERATURES...WITH A FEW BREAKS POSSIBLE NEAR THE WARM FRONT...
AREAS FROM YANKTON TO STORM LAKE AND SOUTHWARD SHOULD HIT 60 TO
65...PROGRESSIVELY COOLING OFF HEADING NORTHWARD. TONIGHT IS
TRICKY...AND HAD TO ADD IN A SNOW MIX TO OUR NORTHERN AND WESTERN
ZONES AS SURFACE TEMPERATURES COOL INTO THE MID 30S IN THOSE AREAS
COUPLED WITH SUB ZERO 850MB TEMPERATURES. USED THE MODEL CONSENSUS
850MB -2 DEGREE C AND 925MB ZERO DEGREE C ISOTHERMS FOR THE RAIN AND
SNOW LINES...COUPLED WITH TEMPERATURES NEAR 35.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 AM CDT MON APR 28 2014
TUESDAY WILL START FAIRLY RAINY OVER THE AREA...THOUGH AMOUNTS
SHOULD BE LESS THAN A QUARTER INCH FOR THE DAY. DRYING WILL BEGIN
FROM THE NORTH/NORTHEAST DURING THE AFTERNOON OVER THE WESTERN PART
OF THE FORECAST AREA AS SOME SUBSIDENCE SPREADS IN FROM THE NORTH/
NORTHEAST BETWEEN LOBES ROTATING AROUND THE UPPER LOW TO THE EAST.
FOR NOW WILL KEEP SOME VERY MINIMAL POPS IN THE WEST FOR TUESDAY
NIGHT...WHILE ONLY SHAVING POPS TO LOW LIKELIES ALONG OUR EASTERN
EDGE IN MN AND IA. FOR NOW AM GOING FOR ALL OF THIS PRECIPITATION TO
BE LIGHT RAIN EXCEPT MAYBE SOME MODERATE RAIN LINGERING TUESDAY
MORNING IN THE EAST...MAYBE WITH A BIT OF WET SNOW MIXED IN WEST AND
NORTH EARLY MORNING BUT NO ACCUMULATION. FOR TUESDAY NIGHT...THOUGH
TEMPERATURES ALOFT WILL BE MARGINAL FOR A LITTLE MIXED SNOW AGAIN...
THERE MAY BE NO PRECIPITATION AT ALL IN THE WEST WHICH WOULD HAVE
THE BETTER SHOT AT SOME SNOW. SURFACE AND NEAR SURFACE TEMPERATURES
WILL LIKELY BE A BIT TOO WARM WITH THE LIGHTER NATURE OF
PRECIPITATION...IF THERE IS ANY AROUND IN THE FIRST PLACE...AND
DYNAMIC COOLING WILL BE NIL. TO THE EAST...THE DEEPER MOIST AIR
SHOULD PRECLUDE ENOUGH COOLING TO GET SNOW TO THE SURFACE...AND EVEN
THERE THE PRECIPITATION SHOULD BE PRETTY LIGHT. TEMPERATURES WILL
NOT BE SHOWING A LOT OF SPREAD WITH 40S HIGHS AND 30S LOWS. IT WILL
STILL BE WINDY TUESDAY BUT EXPECT WINDS WILL STAY BELOW ADVISORY
CRITERIA.
WEDNESDAY WILL BRING THE NEXT LOBE ROTATING OVER THE AREA AND A
RESURGENCE OF LIGHT RAIN WEST/SOUTHWESTWARD AGAIN. TEMPERATURES
AGAIN WILL CLIMB INTO THE 40S AND IT WILL BE WINDY AGAIN. IT COULD
EVEN BE SLIGHTLY WINDIER THAN TUESDAY WITH THE LOBE PASSING OVER THE
AREA.
THURSDAY WILL BRING THE SYSTEM STARTING TO MOVE SLOWLY EAST OF THE
AREA AND WILL KEEP LIGHT RAIN POPS IN THE CHANCE CATEGORY. WEDNESDAY
NIGHT LOWS SHOULD BE IN THE 30S AGAIN...THOUGH IT MAY BE A DEGREE OR
TWO LESS COOL THERE WITH MODELS HINTING AT VERY SLIGHT LOW LEVEL
WARMING. WITH LESSER PRECIPITATION COVERAGE...THURSDAY DAY
TEMPERATURES ARE EXPECTED TO BE A TAD LESS COOL...UPPER 40S TO LOWER
50S FOR HIGHS. THIS PROCESS WILL CONTINUE ON FRIDAY...REMEMBER THE
SLOWNESS OF THIS SYSTEM...BUT POPS WILL BE PRETTY LOW WITH
PRECIPITATION CONFINED MAINLY TO EAST OF FSD. 50 TO 55 LOOKS RIGHT
FOR HIGHS FRIDAY.
THE WEEKEND SHOULD BE A LITTLE WARMER YET...BUT STILL BELOW
NORMAL...AHEAD OF A CANADIAN WAVE APPROACHING IN NORTHWEST FLOW
BEHIND THE CURRENT SYSTEM. WILL GO WITH THE EXTENDED GUIDANCE GRIDS
OF SHOWER CHANCE PEAKING ABOUT SATURDAY NIGHT. THIS SEEMS TO BE THE
BEST PLAN FOR NOW ON EITHER THE GFS OR EC SOLUTION. THE EC HAS
STRONGER RIDGING BETWEEN SYSTEMS THAN THE GFS AND WOULD BRING
TEMPERATURES A LITTLE CLOSER TO NORMAL FOR THE WEEKEND...BUT THE
LIGHT SHOWER THREAT IS STILL THERE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1228 CDT MON APR 28 2014
LINGERING SFC LOW WILL CONTINUE TO BRING IFR AND LOWER CONDITIONS
TO HON...FSD AND SUX. WAVES OF SHRA WITH LOWER VIS WILL CONTINUE THRU
THE TAF PD WITH CIGS JUPMING AROUND FROM 1KFT TO JUST BELOW 1KFT.
WIND WILL PICK UP AGAIN WITH GUSTS AROUND 30KTS BY TUES MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...
AVIATION...SALLY
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
636 AM CDT MON APR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM CDT MON APR 28 2014
CURRENT WATER VAPOR IMAGERY SHOWS THE LOW IN THE MID LEVELS OF THE
ATMOSPHERE SPINNING AWAY RIGHT IN THE MIDDLE OF NEBRASKA...WITH THE
WELL ADVERTISED DRY SLOT ALOFT NOSING UP IN FRONT OF IT AND
ENCOMPASSING MUCH OF OUR FORECAST AREA. THE MOST PRONOUNCED DRYING
ALOFT IS ALONG THE I 29 CORRIDOR CURRENTLY. MODEL CONSENSUS IS GOOD
IN PROGGING THE LOW SLOWLY EASTWARD TOWARD SOUTHEAST IA BY VERY LATE
TONIGHT. THE SURFACE LOW FOLLOWS SUIT...AND IT LOOKS LIKE OUR ENTIRE
FORECAST AREA WILL BE PLACED NORTH OF THE WARM FRONT THROUGH TODAY
AND TONIGHT. THE BEST CHANCES FOR WIDESPREAD BENEFICIAL RAINFALL
TODAY WILL BE BEHIND THE INVERTED TROUGH WHICH WILL BE CONFINED TO
OUR FAR WESTERN ZONES APPROACHING CENTRAL SD. THE REST OF OUR AREA
WILL SEE LESS NUMEROUS SHOWERS AND RAINFALL. BUT THERE IS ENOUGH
ELEVATED INSTABILITY TO POP A THUNDERSTORM OR TWO ALMOST AT ANYTIME
THROUGHOUT THE ENTIRE DAY...ESPECIALLY WHEN A MICROSCALE AREA OF
WARM AIR ADVECTION DECIDES TO MOVE NORTHWARD WHICH THE MODELS CANNOT
HANDLE VERY WELL ON THAT SCALE. INTERESTINGLY...BOTH THE GFS AND GEM
PAINT A BROAD STRIPE OF DECENT QPF THIS AFTERNOON JUST NORTH OF THE
WARM FRONT FROM SIOUX CITY TO STORM LAKE. IN ADDITION...THE PAST FEW
RUNS OF THE HRRR ARE ALSO SHOWING THE POSSIBILITY OF DECENT
CONVECTION IN THOSE AREAS AGAIN DUE TO THE PROXIMITY OF THE WARM
FRONT JUST TO THE SOUTH. AT THIS TIME...IT LOOKS TOO STABLE FOR MUCH
IN THE WAY OF SEVERE WEATHER...AND ALSO THE WIND SHEAR IS NOT REAL
GREAT FROM SIOUX CITY TO STORM LAKE AS THE ENTIRE LOWEST 3
KILOMETERS HAS A WIND DIRECTION OUT OF THE EAST. ONE THING TO WATCH
FOR HOWEVER IS IF A ROGUE SEVERE STORM WHICH BLOWS UP FURTHER TO THE
SOUTHEAST NUDGES INTO THOSE AREAS BEFORE WEAKENING. TO THE
NORTH...KEPT THE COVERAGE OF POPS IN THE SCATTERED CATEGORY THIS
AFTERNOON ALONG THE I 29 CORRIDOR WHERE THE DRY SLOT ALOFT HAS THE
MOST IMPACT. BUT OTHER AREAS MAY START TO FILL IN MORE WITH RAINFALL
IN OUR FAR EAST AND INTO THE JAMES RIVER VALLEY FROM THE WEST AS
MOISTURE PROGS SATURATE UP BETTER ALOFT.
FEEL THERE IS NO NEED FOR A WIND ADVISORY TODAY AS SOUNDINGS ONLY
MIX TO ABOUT 925-900MB AREA WIDE. WINDS IN THAT LAYER ARE STOUT...
AVERAGING 30 TO 35 KNOTS...BUT USUALLY IT TAKES A LITTLE MORE THAN
THAT TO WARRANT A WIND ADVISORY IN OUR AREA...CLOSER TO 40 KNOTS.
HOWEVER TONIGHT ON THE BACK SIDE OF THE LOW...OUR FAR SOUTHWEST
ZONES MAY GET CLOSE TO ADVISORY CRITERIA AFTER MIDNIGHT. MUCH OF OUR
FORECAST AREA TONIGHT IS WELL PLACED IN THE UPPER LEFT QUADRANT OF
THE LOW TRACK TO RECEIVE PRECIP. THERE IS EVEN SOME WEAK TROWALING
IN THE 290-295K LAYER NUDGING INTO OUR AREA FROM THE EAST...AND
SATURATION LOOKS TO BE IN NO SHORT SUPPLY FROM THE SURFACE TO AROUND
500MB. IN THE EVENING...AGAIN THE I 29 CORRIDOR MAY NOT RECEIVE MUCH
RAIN...BUT PRECIP WILL FILL INTO THAT AREA OVERNIGHT. CONCERNING
TEMPERATURES...WITH A FEW BREAKS POSSIBLE NEAR THE WARM FRONT...
AREAS FROM YANKTON TO STORM LAKE AND SOUTHWARD SHOULD HIT 60 TO
65...PROGRESSIVELY COOLING OFF HEADING NORTHWARD. TONIGHT IS
TRICKY...AND HAD TO ADD IN A SNOW MIX TO OUR NORTHERN AND WESTERN
ZONES AS SURFACE TEMPERATURES COOL INTO THE MID 30S IN THOSE AREAS
COUPLED WITH SUB ZERO 850MB TEMPERATURES. USED THE MODEL CONSENSUS
850MB -2 DEGREE C AND 925MB ZERO DEGREE C ISOTHERMS FOR THE RAIN AND
SNOW LINES...COUPLED WITH TEMPERATURES NEAR 35.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 AM CDT MON APR 28 2014
TUESDAY WILL START FAIRLY RAINY OVER THE AREA...THOUGH AMOUNTS
SHOULD BE LESS THAN A QUARTER INCH FOR THE DAY. DRYING WILL BEGIN
FROM THE NORTH/NORTHEAST DURING THE AFTERNOON OVER THE WESTERN PART
OF THE FORECAST AREA AS SOME SUBSIDENCE SPREADS IN FROM THE NORTH/
NORTHEAST BETWEEN LOBES ROTATING AROUND THE UPPER LOW TO THE EAST.
FOR NOW WILL KEEP SOME VERY MINIMAL POPS IN THE WEST FOR TUESDAY
NIGHT...WHILE ONLY SHAVING POPS TO LOW LIKELIES ALONG OUR EASTERN
EDGE IN MN AND IA. FOR NOW AM GOING FOR ALL OF THIS PRECIPITATION TO
BE LIGHT RAIN EXCEPT MAYBE SOME MODERATE RAIN LINGERING TUESDAY
MORNING IN THE EAST...MAYBE WITH A BIT OF WET SNOW MIXED IN WEST AND
NORTH EARLY MORNING BUT NO ACCUMULATION. FOR TUESDAY NIGHT...THOUGH
TEMPERATURES ALOFT WILL BE MARGINAL FOR A LITTLE MIXED SNOW AGAIN...
THERE MAY BE NO PRECIPITATION AT ALL IN THE WEST WHICH WOULD HAVE
THE BETTER SHOT AT SOME SNOW. SURFACE AND NEAR SURFACE TEMPERATURES
WILL LIKELY BE A BIT TOO WARM WITH THE LIGHTER NATURE OF
PRECIPITATION...IF THERE IS ANY AROUND IN THE FIRST PLACE...AND
DYNAMIC COOLING WILL BE NIL. TO THE EAST...THE DEEPER MOIST AIR
SHOULD PRECLUDE ENOUGH COOLING TO GET SNOW TO THE SURFACE...AND EVEN
THERE THE PRECIPITATION SHOULD BE PRETTY LIGHT. TEMPERATURES WILL
NOT BE SHOWING A LOT OF SPREAD WITH 40S HIGHS AND 30S LOWS. IT WILL
STILL BE WINDY TUESDAY BUT EXPECT WINDS WILL STAY BELOW ADVISORY
CRITERIA.
WEDNESDAY WILL BRING THE NEXT LOBE ROTATING OVER THE AREA AND A
RESURGENCE OF LIGHT RAIN WEST/SOUTHWESTWARD AGAIN. TEMPERATURES
AGAIN WILL CLIMB INTO THE 40S AND IT WILL BE WINDY AGAIN. IT COULD
EVEN BE SLIGHTLY WINDIER THAN TUESDAY WITH THE LOBE PASSING OVER THE
AREA.
THURSDAY WILL BRING THE SYSTEM STARTING TO MOVE SLOWLY EAST OF THE
AREA AND WILL KEEP LIGHT RAIN POPS IN THE CHANCE CATEGORY. WEDNESDAY
NIGHT LOWS SHOULD BE IN THE 30S AGAIN...THOUGH IT MAY BE A DEGREE OR
TWO LESS COOL THERE WITH MODELS HINTING AT VERY SLIGHT LOW LEVEL
WARMING. WITH LESSER PRECIPITATION COVERAGE...THURSDAY DAY
TEMPERATURES ARE EXPECTED TO BE A TAD LESS COOL...UPPER 40S TO LOWER
50S FOR HIGHS. THIS PROCESS WILL CONTINUE ON FRIDAY...REMEMBER THE
SLOWNESS OF THIS SYSTEM...BUT POPS WILL BE PRETTY LOW WITH
PRECIPITATION CONFINED MAINLY TO EAST OF FSD. 50 TO 55 LOOKS RIGHT
FOR HIGHS FRIDAY.
THE WEEKEND SHOULD BE A LITTLE WARMER YET...BUT STILL BELOW
NORMAL...AHEAD OF A CANADIAN WAVE APPROACHING IN NORTHWEST FLOW
BEHIND THE CURRENT SYSTEM. WILL GO WITH THE EXTENDED GUIDANCE GRIDS
OF SHOWER CHANCE PEAKING ABOUT SATURDAY NIGHT. THIS SEEMS TO BE THE
BEST PLAN FOR NOW ON EITHER THE GFS OR EC SOLUTION. THE EC HAS
STRONGER RIDGING BETWEEN SYSTEMS THAN THE GFS AND WOULD BRING
TEMPERATURES A LITTLE CLOSER TO NORMAL FOR THE WEEKEND...BUT THE
LIGHT SHOWER THREAT IS STILL THERE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 632 AM CDT MON APR 28 2014
IT APPEARS WIDESPREAD LIFR TO IFR CONDITIONS WILL BE PERSISTENT
ACROSS THE SIOUX FALLS FORECAST AREA BOTH TODAY AND TONIGHT. IN
ADDITION AS STRONG LOW PRESSURE NUDGES VERY SLOWLY EASTWARD...
WINDS WILL OCCASIONALLY GUST AROUND 25 TO 30 KNOTS AT TIMES BOTH
TODAY AND TONIGHT...AS THE OVERALL FLOW BENDS FROM THE EAST TO THE
NORTH TONIGHT. IN THE NEAR TERM...KSUX IS THE MOST CHALLENGING
SITE IN THAT CLEARING WITH VFR CONDITIONS IS NOT TOO FAR AWAY TO
THEIR SOUTHWEST. HOWEVER...THE WIND PROFILE ALL THE WAY FROM THE
SURFACE TO 500MB IS DECIDEDLY EASTWARD ALL DAY TODAY. SO THEREFORE
IT APPEARS THAT THE CLEARING MAY NEVER MAKE IT INTO KSUX...SO TOOK
THE PESSIMISTIC ROUTE FOR THEM.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
344 AM CDT MON APR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM CDT MON APR 28 2014
CURRENT WATER VAPOR IMAGERY SHOWS THE LOW IN THE MID LEVELS OF THE
ATMOSPHERE SPINNING AWAY RIGHT IN THE MIDDLE OF NEBRASKA...WITH THE
WELL ADVERTISED DRY SLOT ALOFT NOSING UP IN FRONT OF IT AND
ENCOMPASSING MUCH OF OUR FORECAST AREA. THE MOST PRONOUNCED DRYING
ALOFT IS ALONG THE I 29 CORRIDOR CURRENTLY. MODEL CONSENSUS IS GOOD
IN PROGGING THE LOW SLOWLY EASTWARD TOWARD SOUTHEAST IA BY VERY LATE
TONIGHT. THE SURFACE LOW FOLLOWS SUIT...AND IT LOOKS LIKE OUR ENTIRE
FORECAST AREA WILL BE PLACED NORTH OF THE WARM FRONT THROUGH TODAY
AND TONIGHT. THE BEST CHANCES FOR WIDESPREAD BENEFICIAL RAINFALL
TODAY WILL BE BEHIND THE INVERTED TROUGH WHICH WILL BE CONFINED TO
OUR FAR WESTERN ZONES APPROACHING CENTRAL SD. THE REST OF OUR AREA
WILL SEE LESS NUMEROUS SHOWERS AND RAINFALL. BUT THERE IS ENOUGH
ELEVATED INSTABILITY TO POP A THUNDERSTORM OR TWO ALMOST AT ANYTIME
THROUGHOUT THE ENTIRE DAY...ESPECIALLY WHEN A MICROSCALE AREA OF
WARM AIR ADVECTION DECIDES TO MOVE NORTHWARD WHICH THE MODELS CANNOT
HANDLE VERY WELL ON THAT SCALE. INTERESTINGLY...BOTH THE GFS AND GEM
PAINT A BROAD STRIPE OF DECENT QPF THIS AFTERNOON JUST NORTH OF THE
WARM FRONT FROM SIOUX CITY TO STORM LAKE. IN ADDITION...THE PAST FEW
RUNS OF THE HRRR ARE ALSO SHOWING THE POSSIBILITY OF DECENT
CONVECTION IN THOSE AREAS AGAIN DUE TO THE PROXIMITY OF THE WARM
FRONT JUST TO THE SOUTH. AT THIS TIME...IT LOOKS TOO STABLE FOR MUCH
IN THE WAY OF SEVERE WEATHER...AND ALSO THE WIND SHEAR IS NOT REAL
GREAT FROM SIOUX CITY TO STORM LAKE AS THE ENTIRE LOWEST 3
KILOMETERS HAS A WIND DIRECTION OUT OF THE EAST. ONE THING TO WATCH
FOR HOWEVER IS IF A ROGUE SEVERE STORM WHICH BLOWS UP FURTHER TO THE
SOUTHEAST NUDGES INTO THOSE AREAS BEFORE WEAKENING. TO THE
NORTH...KEPT THE COVERAGE OF POPS IN THE SCATTERED CATEGORY THIS
AFTERNOON ALONG THE I 29 CORRIDOR WHERE THE DRY SLOT ALOFT HAS THE
MOST IMPACT. BUT OTHER AREAS MAY START TO FILL IN MORE WITH RAINFALL
IN OUR FAR EAST AND INTO THE JAMES RIVER VALLEY FROM THE WEST AS
MOISTURE PROGS SATURATE UP BETTER ALOFT.
FEEL THERE IS NO NEED FOR A WIND ADVISORY TODAY AS SOUNDINGS ONLY
MIX TO ABOUT 925-900MB AREA WIDE. WINDS IN THAT LAYER ARE STOUT...
AVERAGING 30 TO 35 KNOTS...BUT USUALLY IT TAKES A LITTLE MORE THAN
THAT TO WARRANT A WIND ADVISORY IN OUR AREA...CLOSER TO 40 KNOTS.
HOWEVER TONIGHT ON THE BACK SIDE OF THE LOW...OUR FAR SOUTHWEST
ZONES MAY GET CLOSE TO ADVISORY CRITERIA AFTER MIDNIGHT. MUCH OF OUR
FORECAST AREA TONIGHT IS WELL PLACED IN THE UPPER LEFT QUADRANT OF
THE LOW TRACK TO RECEIVE PRECIP. THERE IS EVEN SOME WEAK TROWALING
IN THE 290-295K LAYER NUDGING INTO OUR AREA FROM THE EAST...AND
SATURATION LOOKS TO BE IN NO SHORT SUPPLY FROM THE SURFACE TO AROUND
500MB. IN THE EVENING...AGAIN THE I 29 CORRIDOR MAY NOT RECEIVE MUCH
RAIN...BUT PRECIP WILL FILL INTO THAT AREA OVERNIGHT. CONCERNING
TEMPERATURES...WITH A FEW BREAKS POSSIBLE NEAR THE WARM FRONT...
AREAS FROM YANKTON TO STORM LAKE AND SOUTHWARD SHOULD HIT 60 TO
65...PROGRESSIVELY COOLING OFF HEADING NORTHWARD. TONIGHT IS
TRICKY...AND HAD TO ADD IN A SNOW MIX TO OUR NORTHERN AND WESTERN
ZONES AS SURFACE TEMPERATURES COOL INTO THE MID 30S IN THOSE AREAS
COUPLED WITH SUB ZERO 850MB TEMPERATURES. USED THE MODEL CONSENSUS
850MB -2 DEGREE C AND 925MB ZERO DEGREE C ISOTHERMS FOR THE RAIN AND
SNOW LINES...COUPLED WITH TEMPERATURES NEAR 35.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 AM CDT MON APR 28 2014
TUESDAY WILL START FAIRLY RAINY OVER THE AREA...THOUGH AMOUNTS
SHOULD BE LESS THAN A QUARTER INCH FOR THE DAY. DRYING WILL BEGIN
FROM THE NORTH/NORTHEAST DURING THE AFTERNOON OVER THE WESTERN PART
OF THE FORECAST AREA AS SOME SUBSIDENCE SPREADS IN FROM THE NORTH/
NORTHEAST BETWEEN LOBES ROTATING AROUND THE UPPER LOW TO THE EAST.
FOR NOW WILL KEEP SOME VERY MINIMAL POPS IN THE WEST FOR TUESDAY
NIGHT...WHILE ONLY SHAVING POPS TO LOW LIKELIES ALONG OUR EASTERN
EDGE IN MN AND IA. FOR NOW AM GOING FOR ALL OF THIS PRECIPITATION TO
BE LIGHT RAIN EXCEPT MAYBE SOME MODERATE RAIN LINGERING TUESDAY
MORNING IN THE EAST...MAYBE WITH A BIT OF WET SNOW MIXED IN WEST AND
NORTH EARLY MORNING BUT NO ACCUMULATION. FOR TUESDAY NIGHT...THOUGH
TEMPERATURES ALOFT WILL BE MARGINAL FOR A LITTLE MIXED SNOW AGAIN...
THERE MAY BE NO PRECIPITATION AT ALL IN THE WEST WHICH WOULD HAVE
THE BETTER SHOT AT SOME SNOW. SURFACE AND NEAR SURFACE TEMPERATURES
WILL LIKELY BE A BIT TOO WARM WITH THE LIGHTER NATURE OF
PRECIPITATION...IF THERE IS ANY AROUND IN THE FIRST PLACE...AND
DYNAMIC COOLING WILL BE NIL. TO THE EAST...THE DEEPER MOIST AIR
SHOULD PRECLUDE ENOUGH COOLING TO GET SNOW TO THE SURFACE...AND EVEN
THERE THE PRECIPITATION SHOULD BE PRETTY LIGHT. TEMPERATURES WILL
NOT BE SHOWING A LOT OF SPREAD WITH 40S HIGHS AND 30S LOWS. IT WILL
STILL BE WINDY TUESDAY BUT EXPECT WINDS WILL STAY BELOW ADVISORY
CRITERIA.
WEDNESDAY WILL BRING THE NEXT LOBE ROTATING OVER THE AREA AND A
RESURGENCE OF LIGHT RAIN WEST/SOUTHWESTWARD AGAIN. TEMPERATURES
AGAIN WILL CLIMB INTO THE 40S AND IT WILL BE WINDY AGAIN. IT COULD
EVEN BE SLIGHTLY WINDIER THAN TUESDAY WITH THE LOBE PASSING OVER THE
AREA.
THURSDAY WILL BRING THE SYSTEM STARTING TO MOVE SLOWLY EAST OF THE
AREA AND WILL KEEP LIGHT RAIN POPS IN THE CHANCE CATEGORY. WEDNESDAY
NIGHT LOWS SHOULD BE IN THE 30S AGAIN...THOUGH IT MAY BE A DEGREE OR
TWO LESS COOL THERE WITH MODELS HINTING AT VERY SLIGHT LOW LEVEL
WARMING. WITH LESSER PRECIPITATION COVERAGE...THURSDAY DAY
TEMPERATURES ARE EXPECTED TO BE A TAD LESS COOL...UPPER 40S TO LOWER
50S FOR HIGHS. THIS PROCESS WILL CONTINUE ON FRIDAY...REMEMBER THE
SLOWNESS OF THIS SYSTEM...BUT POPS WILL BE PRETTY LOW WITH
PRECIPITATION CONFINED MAINLY TO EAST OF FSD. 50 TO 55 LOOKS RIGHT
FOR HIGHS FRIDAY.
THE WEEKEND SHOULD BE A LITTLE WARMER YET...BUT STILL BELOW
NORMAL...AHEAD OF A CANADIAN WAVE APPROACHING IN NORTHWEST FLOW
BEHIND THE CURRENT SYSTEM. WILL GO WITH THE EXTENDED GUIDANCE GRIDS
OF SHOWER CHANCE PEAKING ABOUT SATURDAY NIGHT. THIS SEEMS TO BE THE
BEST PLAN FOR NOW ON EITHER THE GFS OR EC SOLUTION. THE EC HAS
STRONGER RIDGING BETWEEN SYSTEMS THAN THE GFS AND WOULD BRING
TEMPERATURES A LITTLE CLOSER TO NORMAL FOR THE WEEKEND...BUT THE
LIGHT SHOWER THREAT IS STILL THERE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1120 PM CDT SUN APR 27 2014
WIDESPREAD CEILINGS AROUND 500 TO 1500 WILL BE THE MAIN STORY THROUGH
THE PERIOD. SOME VFR CEILINGS NEAR THE MISSOURI VALLEY WILL QUICKLY
GIVE WAY TO LOW STRATUS THROUGH THE NEXT FEW HOURS...WITH SHOWERS AND
THUNDERSTORMS PUSHING INTO SOUTH CENTRAL SD INTO THE EARLY MORNING
HOURS. CEILINGS AND VISIBILITY WILL FURTHER DROP IN ANY SHOWERS AND
STORMS. STRATUS STICKS AROUND THROUGHOUT THE DAY ON MONDAY...WITH THE
ONLY POTENTIAL LIFTING OF CEILINGS ABOVE 3000 EXPECTED NEAR THE
MISSOURI RIVER ONCE AGAIN. ADDITIONAL SHOWER ACTIVITY SPREADS FROM
WEST TO EAST MAINLY 15Z THROUGH THE END OF THE TAF PERIOD. WINDS
WILL REMAIN GENERALLY EASTERLY AND BREEZY AROUND 15 TO 25 KT WITH
GUSTS TO 32 KT...BUT WILL BEGIN TO SHIFT NORTHEAST THEN NORTH ACROSS
OUR WESTERN HALF AFTER 21Z. A LULL IN THE WINDS WILL DEVELOP ON
MONDAY NEAR THE MISSOURI VALLEY. ISOLATED STRONGER OR SEVERE STORMS ARE
ALSO POSSIBLE MONDAY AFTERNOON AND EVENING MAINLY NEAR THE MISSOURI
VALLEY...WITH HAIL AND GUSTY WINDS POSSIBLE.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1152 PM MDT SUN APR 27 2014
.UPDATE...
ISSUED AT 1147 PM MDT SUN APR 27 2014
RAIN HAS CHANGED TO SNOW ACROSS NORTHWESTERN SOUTH DAKOTA. EXPECT
SNOWFALL TO CONTINUE INTO MONDAY MORNING WITH AMOUNTS OF 2 TO 5
INCHES. THUS DELAYED THE WIND ADVISORY UNTIL 18Z AND STARTED A
WINTER WEATHER ADVISORY FOR NORTHWESTERN SOUTH DAKOTA THAT GOES
UNTIL 18Z.
UPDATE ISSUED AT 939 PM MDT SUN APR 27 2014
DECIDED TO START HIGH WIND WARNING SINCE THE AREA IN THE WATCH WAS
ALREADY IN WARNING CRITERIA...KRAP GUST TO 52KT AT 0202Z. LOOKING
AT LATEST HI RES MODEL GUIDANCE...HRRR AND RAP...LOOKS LIKE 30 TO 40
MPH WINDS WILL CONTINUE THRU THE NIGHT BEFORE REALLY PICKING UP BY
13Z MONDAY. SEEING VERY STRONG DOWNSLOPE WINDS FROM THE BLACK
HILLS IN THE HIGH WIND WARNING AREA. COULD SEE SOME LIGHTER WINDS
OVERNIGHT...HOWEVER SINCE WE WERE ALREADY HAVING HIGH WINDS AND
CONFIDENCE IN HIGH WINDS FOR MONDAY AND TUESDAY WERE
HIGH...DECIDED TO GO WITH THE WARNING.
UPDATE ISSUED AT 822 PM MDT SUN APR 27 2014
DECIDED TO PUT OUT A WINTER WEATHER ADVISORY FOR SNOW FOR SHANNON
AND BENNETT COUNTIES. MADE A FEW CALLS AND LOOKING AT WEBCAMS
MARTIN ALREADY HAD AN INCH AND PINE RIDGE HAD A COUPLE INCHES.
LATEST RAP MODEL AND HRRR BOTH INDICATE A TROWAL SETTING UP OVER
THIS AREA TONIGHT. EXPECT A BAND OF HEAVY SNOW WITH AMOUNTS OF 2
TO 5 INCHES FOR THIS AREA. ONLY HAVE THE ADVISORY TIL 12Z...BUT
SNOW MAY CONTINUE A BIT LONGER. ONCE THE SNOW STOPS THE WINDS WILL
START IN THIS AREA SO KEPT WIND ADVISORY BEGINNING AT 12Z. NEXT
SHIFT MAY HAVE TO ADJUST THE TIMING DEPENDING ON THE SNOWFALL.
UPDATE ISSUED AT 640 PM MDT SUN APR 27 2014
LATEST HRRR MODEL AND SURFACE ANALYSIS SHOWS A LEE MESO-LOW OVER
CENTRAL CUSTER COUNTY. THE ISOBARS SHOW A TIGHT GRADIENT OVER
WESTERN FALL RIVER COUNTY AND ALONG THE EASTERN FOOTHILLS FROM
RAPID CITY TO HERMOSA AND ABOUT 60 MILES EAST ONTO THE PLAINS.
THIS FEATURE IS PROGGED TO CONTINUE THROUGH 02Z-03Z THIS EVENING. THE
RESULT WILL BE A BRIEF PERIOD OF GUSTY NORTHWEST WINDS OF 35 TO 40
MPH AND GUSTS UP TO 55 MPH. SINCE THIS FEATURE IS VERY LOCALIZED
AND WILL BE SHORT LIVED WITH WINDS DIMINISHING AFTER 03Z BEFORE
INCREASING AGAIN EARLY MONDAY MORNING...THOUGHT IT WOULD BE BEST
COVERED WITH A SPECIAL WEATHER STATEMENT INSTEAD OF GOING WITH A
WIND ADVISORY OR HIGH WIND WARNING.
OTHERWISE THE FORECAST IS ON TRACK...AM WATCHING THE NORTHERN
HILLS CLOSELY SINCE SOME AREAS HAVE ALREADY PICKED UP A FEW INCHES
OF SNOW. HOWEVER WINTER STORM WARNING AT THE HIGHER ELEVATIONS AND
WINTER WEATHER ADVISORY AROUND SPEARFISH LOOK TO BE GOOD AT THIS TIME.
&&
.SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT
ISSUED AT 219 PM MDT SUN APR 27 2014
CURRENT SURFACE ANALYSIS PLACES LOW OVER NWRN KANSAS/SWRN
NEBRASKA...WHILE UPPER LEVEL ANALYSIS INDICATES LOW HAS BECOME
STACKED. TWO MAIN AREAS OF PRECIP HAVE DEVELOPED OVER THE CWA WITH
THE FIRST ONE ORIENTATED N/S ALONG THE WRN SD BORDER ALONG AREA OF
STRONG MID-LEVEL FRONTOGENESIS WHILE SECONDARY AREA OF PRIMARILY
THUNDERSTORMS CONTINUES TO PUSH W/NWRLY NEAR NOSE OF JET STREAK.
FOR THE REST OF THIS AFTERNOON INTO TONIGHT...A POTPOURRI OF
WEATHER TYPES ARE EXPECTED AS STRONG LOW PRESSURE SYSTEM CREEPS
ITS WAY THROUGH THE REGION. LATEST GUIDANCE KEEPING THE SYSTEM A
BIT FURTHER SOUTH THAN PREVIOUSLY THOUGHT WITH LOW SLOWLY SHIFTING
THROUGH THE NIGHT TOWARDS CTRL NEBRASKA. PLENTY OF MOISTURE WILL
CONTINUE TO WRAP INTO THE SYSTEM KEEPING PRECIPITATION GOING
THROUGH THE NIGHT. KEY FORECAST CHALLENGE IS PRECIP TYPES. APPEARS
CHANGEOVER TO SNOW HAS OCCURRED OVER THE BLKHLS FOLLOWING A COOLER
SOLUTION GIVEN THE SOUTHERN TREND OF THE MODELS. WITH SNOW
EXPECTED TO CONTINUE GIVEN LARGE SCALE FORCING ALONG WITH UPSLOPE
ENHANCEMENT HAVE UPGRADED TO WINTER STORM WARNING. TOWARDS THE ERN
CWA MODELS CONTINUE TO INDICATE MODEST INSTABILITY SO WILL KEEP
THUNDERSTORM CHANCES GOING INTO EVENING. THE TRICKY PART IS THE
REMAINDER OF THE CWA WHERE TEMPERATURES ARE EXPECTED TO BE RIGHT
NEAR THE RAIN/SNOW TRANSITION. HAVE KEEP SNOW ACCUMULATIONS
TONIGHT OVER THE PLAINS ON THE LIGHTER SIDE BUT WILL RE-EVALUATE
THIS THRU THE AFTERNOON/EVE BECAUSE IF ENOUGH COLD AIR PULLS IN
RESULTING IN AN EARLY TRANSITION MORE SNOW WILL NEED TO BE ADDED.
ON MONDAY...LOW SLOWLY LOITERS ITS WAY TOWARDS ERN NEBRASKA WITH
PRECIPITATION CONTINUING TO AFFECT THE AREA. NEW CONCERN ADDED TO
THE EQUATION WILL BE WINDS WITH PRESSURE GRADIENT TIGHTENING OVER
THE AREA. GUSTY WINDS WILL BE ON THE INCREASE IN THE
MORNING...WITH THE STRONGEST WINDS OVER THE ERN SIDE OF THE BLACK
HILLS. PRECIP TYPES REMAIN TRICKY GIVEN THE TEMPS REMAINING NEAR
THE TRANSITION...BUT CURRENTLY LOOKS AS IF MOST AREAS SHOULD BE
RAIN IN THE AFTERNOON.
MONDAY NIGHT...LOW WORKS ITS WAY TOWARDS THE IOWA/MISSOURI BORDER
OVERNIGHT. EXPECT COOLER AIR TO WORK INTO THE SYSTEM BRINGING A
PROBABLE TRANSITION TOWARDS SNOW TO MOST AREAS...THOUGH PRECIP
RATES SHOULD BE LOWER...PARTICULARLY OVER THE FAR WRN CWA WITH THE
SYSTEM SLOWLY PUSHING EAST.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
ISSUED AT 219 PM MDT SUN APR 27 2014
CLOSED UPPER LOW WILL SLOWLY MEANDER EAST IN THE
PERIOD...SUPPORTING SEMI-BLOCKED FLOW. HEAVY NON-PROGRESSIVE
TENDENCIES FAVORED IN THE PERIOD WITH COOL BELOW NORMAL TEMPS
EXPECTED. LINGERING WANING DEFORMATION ZONE WILL BE PRESENT OVER THE
FA AT THE START OF THE PERIOD...SUPPORTING SNOW ACCUMULATIONS AT
SOME LOCATIONS. ALTHOUGH THIS SYSTEM WILL SHIFT EAST SLOWLY THE
REMAINDER OF THE PERIOD...CYCLONIC FLOW WITH STEEP LAPSE RATES WILL
LINGER THROUGH MUCH OF THE PERIOD BEFORE THE WESTERN NOAM RIDGE
BEGINS TO EDGE EAST. HOWEVER...GIVEN THE HIGH AMPLITUDE NATURE OF
THE UPPER RIDGE...WITH HIGH LATITUDINAL EXTENT...LONG TRAJECTORY
NORTHERLY FLOW WILL SET THE STAGE FOR ANOTHER INTRUSION OF CP TOWARD
THE END OF THE PERIOD. THIS HAS FAVORED A DOWNWARD TREND IN TEMPS IN
THE SUNDAY PERIOD. GIVEN H85 TEMPS IN THE -2 TO 0C RANGE WITH A
PASSING DISTURBANCE...SNOW ACCUMS MAY BE A POSSIBILITY ONCE
AGAIN...ESP IN THE HIGHER TERRAIN.
TUE-THU...LINGERING DEFORMATION ZONE WILL SUPPORT CHANCES FOR LIGHT
RAIN/SNOW...ESP IN THE TUE PERIOD...WITH A HEAVY WANE IN ACTIVITY
TOWARD WED GIVEN EAST PROPAGATION OF THE UPPER LOW WITH DRY AIR ADV
INTO THE FA FORM THE NORTH. HOWEVER...LINGERING CYCLONIC FLOW WITH
STEEP LL LAPSE RATES AND AVAILABLE LL MOISTURE WILL BE SUFFICIENT
FOR A FEW SHOWERS INTO THUR. ADJUSTED TEMPS DOWN SOME...ESP TUE
GIVEN PRECIP WITH AMPLE CLOUD CLOVER AND COOL THERMAL FIELDS.
MODERATE SNOW ACCUMS ARE EXPECTED INTO TUE MORNING OVER THE NORTHERN
BLACK HILLS...WITH SOME LIGHT ACCUMS ON THE SD PLAINS...UP TO AN
INCH OR SO.
THU-SUN...SLIGHT WARMING TREND THROUGH FRIDAY WITH LINGERING LOW
CHANCES FOR SHOWERS THU. RIDGE FRONT DISTURBANCE LOOKS TO SHIFT SE
INTO THE REGION FRI...POSSIBLY SUPPORTING A FEW SHOWERS WITH PEAK
HEATING. OTHERWISE...A POTENTIALLY STRONGER SYSTEM LOOKS TO AFFECT
THE REGION INTO THE WEEKEND...BRING MORE COOLER WEATHER BY SUNDAY
AND THE CHANCE FOR RAIN AND/OR SNOW ONCE AGAIN. GIVEN AVAILABILITY
OF COLD AIR PER HIGH LATITUDE RIDGING...THE POTENTIAL WILL EXIST FOR
SOME SNOW ACCUMS.
&&
.AVIATION...FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT
ISSUED AT 1119 PM MDT SUN APR 27 2014
RAIN AND SNOW SHOWERS WILL CONTINUE THROUGH THE PERIOD WITH
WIDESPREAD IFR CONDITIONS OVER THE BLACK HILLS AND SD PLAINS.
DOWNSLOPING SHOULD CONFINE CIGS TO MVFR AT KRAP THROUGH MOST OF
THE PERIOD. GUSTY NORTHWESTERLY WINDS WILL CONTINUE TO INCREASE
OVERNIGHT WITH SURFACE WINDS OF 50KT POSSIBLE AROUND KRAP BY
MONDAY MORNING. A DRY SLOT WILL BRING VFR CONDITIONS TO PORTIONS
OF NE WYOMING AND SOUTH CENTRAL SOUTH DAKOTA THROUGH 12Z.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR SDZ024-028.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT MONDAY FOR SDZ042-044.
WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ MONDAY TO 6 PM MDT /7 PM
CDT/ TUESDAY FOR SDZ013-014-027-032-041>044-046-047-049.
WINTER WEATHER ADVISORY UNTIL NOON MDT MONDAY FOR SDZ001-002-012-
025.
WIND ADVISORY FROM NOON MONDAY TO 6 PM MDT TUESDAY FOR SDZ001-
002-012-025.
HIGH WIND WARNING UNTIL 6 PM MDT TUESDAY FOR SDZ026-030-031-
072>074.
WY...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR WYZ057.
&&
$$
UPDATE...MLS
SHORT TERM...77
LONG TERM...JC
AVIATION...MLS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1122 PM MDT SUN APR 27 2014
.UPDATE...
ISSUED AT 939 PM MDT SUN APR 27 2014
DECIDED TO START HIGH WIND WARNING SINCE THE AREA IN THE WATCH WAS
ALREADY IN WARNING CRITERIA...KRAP GUST TO 52KT AT 0202Z. LOOKING
AT LATEST HI RES MODEL GUIDANCE...HRRR AND RAP...LOOKS LIKE 30 TO 40
MPH WINDS WILL CONTINUE THRU THE NIGHT BEFORE REALLY PICKING UP BY
13Z MONDAY. SEEING VERY STRONG DOWNSLOPE WINDS FROM THE BLACK
HILLS IN THE HIGH WIND WARNING AREA. COULD SEE SOME LIGHTER WINDS
OVERNIGHT...HOWEVER SINCE WE WERE ALREADY HAVING HIGH WINDS AND
CONFIDENCE IN HIGH WINDS FOR MONDAY AND TUESDAY WERE
HIGH...DECIDED TO GO WITH THE WARNING.
UPDATE ISSUED AT 822 PM MDT SUN APR 27 2014
DECIDED TO PUT OUT A WINTER WEATHER ADVISORY FOR SNOW FOR SHANNON
AND BENNETT COUNTIES. MADE A FEW CALLS AND LOOKING AT WEBCAMS
MARTIN ALREADY HAD AN INCH AND PINE RIDGE HAD A COUPLE INCHES.
LATEST RAP MODEL AND HRRR BOTH INDICATE A TROWAL SETTING UP OVER
THIS AREA TONIGHT. EXPECT A BAND OF HEAVY SNOW WITH AMOUNTS OF 2
TO 5 INCHES FOR THIS AREA. ONLY HAVE THE ADVISORY TIL 12Z...BUT
SNOW MAY CONTINUE A BIT LONGER. ONCE THE SNOW STOPS THE WINDS WILL
START IN THIS AREA SO KEPT WIND ADVISORY BEGINNING AT 12Z. NEXT
SHIFT MAY HAVE TO ADJUST THE TIMING DEPENDING ON THE SNOWFALL.
UPDATE ISSUED AT 640 PM MDT SUN APR 27 2014
LATEST HRRR MODEL AND SURFACE ANALYSIS SHOWS A LEE MESO-LOW OVER
CENTRAL CUSTER COUNTY. THE ISOBARS SHOW A TIGHT GRADIENT OVER
WESTERN FALL RIVER COUNTY AND ALONG THE EASTERN FOOTHILLS FROM
RAPID CITY TO HERMOSA AND ABOUT 60 MILES EAST ONTO THE PLAINS.
THIS FEATURE IS PROGGED TO CONTINUE THROUGH 02Z-03Z THIS EVENING. THE
RESULT WILL BE A BRIEF PERIOD OF GUSTY NORTHWEST WINDS OF 35 TO 40
MPH AND GUSTS UP TO 55 MPH. SINCE THIS FEATURE IS VERY LOCALIZED
AND WILL BE SHORT LIVED WITH WINDS DIMINISHING AFTER 03Z BEFORE
INCREASING AGAIN EARLY MONDAY MORNING...THOUGHT IT WOULD BE BEST
COVERED WITH A SPECIAL WEATHER STATEMENT INSTEAD OF GOING WITH A
WIND ADVISORY OR HIGH WIND WARNING.
OTHERWISE THE FORECAST IS ON TRACK...AM WATCHING THE NORTHERN
HILLS CLOSELY SINCE SOME AREAS HAVE ALREADY PICKED UP A FEW INCHES
OF SNOW. HOWEVER WINTER STORM WARNING AT THE HIGHER ELEVATIONS AND
WINTER WEATHER ADVISORY AROUND SPEARFISH LOOK TO BE GOOD AT THIS TIME.
&&
.SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT
ISSUED AT 219 PM MDT SUN APR 27 2014
CURRENT SURFACE ANALYSIS PLACES LOW OVER NWRN KANSAS/SWRN
NEBRASKA...WHILE UPPER LEVEL ANALYSIS INDICATES LOW HAS BECOME
STACKED. TWO MAIN AREAS OF PRECIP HAVE DEVELOPED OVER THE CWA WITH
THE FIRST ONE ORIENTATED N/S ALONG THE WRN SD BORDER ALONG AREA OF
STRONG MID-LEVEL FRONTOGENESIS WHILE SECONDARY AREA OF PRIMARILY
THUNDERSTORMS CONTINUES TO PUSH W/NWRLY NEAR NOSE OF JET STREAK.
FOR THE REST OF THIS AFTERNOON INTO TONIGHT...A POTPOURRI OF
WEATHER TYPES ARE EXPECTED AS STRONG LOW PRESSURE SYSTEM CREEPS
ITS WAY THROUGH THE REGION. LATEST GUIDANCE KEEPING THE SYSTEM A
BIT FURTHER SOUTH THAN PREVIOUSLY THOUGHT WITH LOW SLOWLY SHIFTING
THROUGH THE NIGHT TOWARDS CTRL NEBRASKA. PLENTY OF MOISTURE WILL
CONTINUE TO WRAP INTO THE SYSTEM KEEPING PRECIPITATION GOING
THROUGH THE NIGHT. KEY FORECAST CHALLENGE IS PRECIP TYPES. APPEARS
CHANGEOVER TO SNOW HAS OCCURRED OVER THE BLKHLS FOLLOWING A COOLER
SOLUTION GIVEN THE SOUTHERN TREND OF THE MODELS. WITH SNOW
EXPECTED TO CONTINUE GIVEN LARGE SCALE FORCING ALONG WITH UPSLOPE
ENHANCEMENT HAVE UPGRADED TO WINTER STORM WARNING. TOWARDS THE ERN
CWA MODELS CONTINUE TO INDICATE MODEST INSTABILITY SO WILL KEEP
THUNDERSTORM CHANCES GOING INTO EVENING. THE TRICKY PART IS THE
REMAINDER OF THE CWA WHERE TEMPERATURES ARE EXPECTED TO BE RIGHT
NEAR THE RAIN/SNOW TRANSITION. HAVE KEEP SNOW ACCUMULATIONS
TONIGHT OVER THE PLAINS ON THE LIGHTER SIDE BUT WILL RE-EVALUATE
THIS THRU THE AFTERNOON/EVE BECAUSE IF ENOUGH COLD AIR PULLS IN
RESULTING IN AN EARLY TRANSITION MORE SNOW WILL NEED TO BE ADDED.
ON MONDAY...LOW SLOWLY LOITERS ITS WAY TOWARDS ERN NEBRASKA WITH
PRECIPITATION CONTINUING TO AFFECT THE AREA. NEW CONCERN ADDED TO
THE EQUATION WILL BE WINDS WITH PRESSURE GRADIENT TIGHTENING OVER
THE AREA. GUSTY WINDS WILL BE ON THE INCREASE IN THE
MORNING...WITH THE STRONGEST WINDS OVER THE ERN SIDE OF THE BLACK
HILLS. PRECIP TYPES REMAIN TRICKY GIVEN THE TEMPS REMAINING NEAR
THE TRANSITION...BUT CURRENTLY LOOKS AS IF MOST AREAS SHOULD BE
RAIN IN THE AFTERNOON.
MONDAY NIGHT...LOW WORKS ITS WAY TOWARDS THE IOWA/MISSOURI BORDER
OVERNIGHT. EXPECT COOLER AIR TO WORK INTO THE SYSTEM BRINGING A
PROBABLE TRANSITION TOWARDS SNOW TO MOST AREAS...THOUGH PRECIP
RATES SHOULD BE LOWER...PARTICULARLY OVER THE FAR WRN CWA WITH THE
SYSTEM SLOWLY PUSHING EAST.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
ISSUED AT 219 PM MDT SUN APR 27 2014
CLOSED UPPER LOW WILL SLOWLY MEANDER EAST IN THE
PERIOD...SUPPORTING SEMI-BLOCKED FLOW. HEAVY NON-PROGRESSIVE
TENDENCIES FAVORED IN THE PERIOD WITH COOL BELOW NORMAL TEMPS
EXPECTED. LINGERING WANING DEFORMATION ZONE WILL BE PRESENT OVER THE
FA AT THE START OF THE PERIOD...SUPPORTING SNOW ACCUMULATIONS AT
SOME LOCATIONS. ALTHOUGH THIS SYSTEM WILL SHIFT EAST SLOWLY THE
REMAINDER OF THE PERIOD...CYCLONIC FLOW WITH STEEP LAPSE RATES WILL
LINGER THROUGH MUCH OF THE PERIOD BEFORE THE WESTERN NOAM RIDGE
BEGINS TO EDGE EAST. HOWEVER...GIVEN THE HIGH AMPLITUDE NATURE OF
THE UPPER RIDGE...WITH HIGH LATITUDINAL EXTENT...LONG TRAJECTORY
NORTHERLY FLOW WILL SET THE STAGE FOR ANOTHER INTRUSION OF CP TOWARD
THE END OF THE PERIOD. THIS HAS FAVORED A DOWNWARD TREND IN TEMPS IN
THE SUNDAY PERIOD. GIVEN H85 TEMPS IN THE -2 TO 0C RANGE WITH A
PASSING DISTURBANCE...SNOW ACCUMS MAY BE A POSSIBILITY ONCE
AGAIN...ESP IN THE HIGHER TERRAIN.
TUE-THU...LINGERING DEFORMATION ZONE WILL SUPPORT CHANCES FOR LIGHT
RAIN/SNOW...ESP IN THE TUE PERIOD...WITH A HEAVY WANE IN ACTIVITY
TOWARD WED GIVEN EAST PROPAGATION OF THE UPPER LOW WITH DRY AIR ADV
INTO THE FA FORM THE NORTH. HOWEVER...LINGERING CYCLONIC FLOW WITH
STEEP LL LAPSE RATES AND AVAILABLE LL MOISTURE WILL BE SUFFICIENT
FOR A FEW SHOWERS INTO THUR. ADJUSTED TEMPS DOWN SOME...ESP TUE
GIVEN PRECIP WITH AMPLE CLOUD CLOVER AND COOL THERMAL FIELDS.
MODERATE SNOW ACCUMS ARE EXPECTED INTO TUE MORNING OVER THE NORTHERN
BLACK HILLS...WITH SOME LIGHT ACCUMS ON THE SD PLAINS...UP TO AN
INCH OR SO.
THU-SUN...SLIGHT WARMING TREND THROUGH FRIDAY WITH LINGERING LOW
CHANCES FOR SHOWERS THU. RIDGE FRONT DISTURBANCE LOOKS TO SHIFT SE
INTO THE REGION FRI...POSSIBLY SUPPORTING A FEW SHOWERS WITH PEAK
HEATING. OTHERWISE...A POTENTIALLY STRONGER SYSTEM LOOKS TO AFFECT
THE REGION INTO THE WEEKEND...BRING MORE COOLER WEATHER BY SUNDAY
AND THE CHANCE FOR RAIN AND/OR SNOW ONCE AGAIN. GIVEN AVAILABILITY
OF COLD AIR PER HIGH LATITUDE RIDGING...THE POTENTIAL WILL EXIST FOR
SOME SNOW ACCUMS.
&&
.AVIATION...FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT
ISSUED AT 1119 PM MDT SUN APR 27 2014
RAIN AND SNOW SHOWERS WILL CONTINUE THROUGH THE PERIOD WITH
WIDESPREAD IFR CONDITIONS OVER THE BLACK HILLS AND SD PLAINS.
DOWNSLOPING SHOULD CONFINE CIGS TO MVFR AT KRAP THROUGH MOST OF
THE PERIOD. GUSTY NORTHWESTERLY WINDS WILL CONTINUE TO INCREASE
OVERNIGHT WITH SURFACE WINDS OF 50KT POSSIBLE AROUND KRAP BY
MONDAY MORNING. A DRY SLOT WILL BRING VFR CONDITIONS TO PORTIONS
OF NE WYOMING AND SOUTH CENTRAL SOUTH DAKOTA THROUGH 12Z.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR SDZ024-028.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT MONDAY FOR SDZ042-044.
WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ MONDAY TO 6 PM MDT /7 PM
CDT/ TUESDAY FOR SDZ001-002-012>014-025-027-032-041>044-046-
047-049.
HIGH WIND WARNING UNTIL 6 PM MDT TUESDAY FOR SDZ026-030-031-
072>074.
WINTER WEATHER ADVISORY UNTIL NOON MDT MONDAY FOR SDZ025.
WY...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR WYZ057.
&&
$$
UPDATE...MLS
SHORT TERM...77
LONG TERM...JC
AVIATION...MLS
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
514 PM CDT MON APR 28 2014
.MESOSCALE UPDATE...
LATEST LAPS DATA CLEARLY SHOWS THAT THE BETTER INSTABILITY IS OVER
OUR SOUTHERN AREAS WHICH IS WHERE THE TOR WATCH IS IN EFFECT. CAPE
VALUES...SHOWALTERS ALL IN SUPPORT OF THE SUBSTANTIAL AMOUNTS OF INSTABILITY
ACROSS THE SOUTH. CURRENT RADAR SHOWS THE STRONGEST ACTIVITY FROM
DICKSON COUNTY SOUTHWARD THROUGH GILES COUNTY WITH AGAIN...THE
STRONGEST ACTIVITY THE FURTHER SOUTH YOU GO.
WE DO SEE A LINE OF THUNDERSTORMS ATTEMPTING TO DEVELOP BACK
ACROSS WESTERN KY. HOWEVER...THERE IS A DEGREE OF INCREASING CAP
STRENGTH ACROSS OUR NORTHERN AREAS. THUS...IT MAY HAVE A TOUGH
TIME DEVELOPING INTO SOMETHING MORE SUBSTANTIAL. HRRR FURTHER
CONCURS WITH THE IDEA OF NO REDEVELOPMENT TONIGHT TO THE WEST OF
THE AFOREMENTIONED STRONGEST CONVECTION.
BIGGEST POTENTIAL IMPACT OVER THE NEXT FEW HOURS WILL BE OVER OUR
SOUTHERN AREAS WHERE THE POTENTIALLY TORNADIC CELLS COULD CLIP
OUR FAR SOUTHERN COUNTIES AND EVENTUALLY OUR SOUTHERN PLATEAU.
AS FOR THE FLOOD THREAT...THE FLASH FLOOD WATCH CONTINUES THROUGH
TUESDAY EVENING.
&&
.PREV DISCUSSION... /ISSUED 256 PM CDT MON APR 28 2014/
DISCUSSION...
..SIGNIFICANT SEVERE WEATHER THREAT STILL EXISTS OVER FAR
SOUTHERN MIDDLE TN THROUGH TONIGHT...
A STRONG LOW PRESSURE CENTER OVER EASTERN NEBRASKA WILL DRAG A
COLD FRONT THROUGH THE REGION LATE TONIGHT...WITH ITS UPPER LOW
LAGGING AND SPINNING ACROSS THE UPPER MIDWEST. STRONG DIVERGENCE
ALOFT ON THE NOSE OF A 115-KT UPPER JET HAS LED TO AMPLE PRECIP
ACROSS MIDDLE TN THIS MORNING THROUGH THE EARLY AFTERNOON HOURS.
THIS ACTIVITY HAS LED TO 3-5 INCH RAINFALL AMOUNTS MAINLY WEST OF
I-65 AND SOUTH OF I-40...WHERE RESIDUAL FLOODING AND FLASH
FLOODING CONTINUE. A FLASH FLOOD WATCH CONTINUES FOR ALL OF MIDDLE
TN AND WILL BE EXTENDED THROUGH TUESDAY AFTERNOON GIVEN THE RIVER
FLOODING THREAT FROM ADDITIONAL RAINS FROM THIS EVENING THROUGH
THE OVERNIGHT HOURS. WILL ISSUE THE UPDATED FLASH FLOOD WATCH SOON.
MORE INTERESTINGLY...THE MORNING CONVECTION DROPPED AN OUTFLOW
BOUNDARY ACROSS FAR SOUTHERN MIDDLE TN...WHERE POINTS NORTH OF
THAT BOUNDARY REMAIN IN THE COLD POOL REGION...AND POINTS ALONG
AND SOUTH OF THIS BOUNDARY REMAIN VERY UNSTABLE. THIS BOUNDARY
EVEN CURLS BACK TO THE WEST A BIT OVER OUR FAR EASTERN CWA. WITH
SFC CAPE VALUES AROUND 2000 J/KG AND AMPLE LOW-LEVEL SHEAR AS
WELL AS DEEP LAYER SHEAR SOUTH OF THIS BOUNDARY...SPC ISSUED A
PDS TORNADO WATCH FOR MAINLY OUR SOUTHERN TWO TIERS OF COUNTIES
UNTIL 9PM. ANYTHING CLOSEST TO THE HUNTSVILLE COUNTY WARNING AREA
WILL HAVE THE BEST CHANCE SEEING A SIGNIFICANT THREAT FOR
SUPERCELLS...WHICH MEANS A TORNADO...HAIL AND DAMAGING WIND
THREAT. TORNADOES ON THE GROUND HAVE BEEN REPORTED IN NORTHERN
MS ALREADY...MOVING NE. IT WILL BE A CLOSE CALL FOR FAR SOUTHERN
MIDDLE TN. FYI...WE WILL ADD GRUNDY COUNTY TO THE WATCH AS WELL.
ALSO...NORTH OF THIS BOUNDARY...SEVERE STORMS WILL STILL BE
POSSIBLE BUT HAIL WILL BE THE ONLY SEVERE WEATHER THREAT FOR
STORMS IN THE COLD POOL.
SUPERCELLS OVER MS SHOULD COAGULATE INTO A LARGE AREA OF
CONVECTION AND THIS SHOULD SPREAD NORTHWARD WITH TIME.
OVERNIGHT...THIS WILL MOVE EAST THROUGH MIDDLE TN...AND POPS COULD
TAPER FROM WEST TO EAST TOWARDS TUESDAY MORNING. AN ADDITIONAL 1-2
INCHES OF RAINFALL WILL BE POSSIBLE THROUGH TONIGHT...WITH LOWS
AROUND 60.
ON TUESDAY...THE SFC LOW SHOULD ROTATE A LITTLE FURTHER EAST AND
ANOTHER LOBE OF ENERGY FROM THE UPPER LOW WILL SWING THROUGH THE
REGION. WOULD THINK ANOTHER ROUND OF AFTERNOON-EVENING CONVECTION
SHOULD EASILY BE GENERATED...THIS TIME WITH MORE SHEAR ACROSS
MIDDLE TN...MORE SUNSHINE THROUGH THE MORNING HOURS...AND COLDER
AIR ALOFT WITH THE UPPER LOW GETTING CLOSER. WOULD EXPECT ANOTHER
ROUND OF SEVERE WEATHER TOMORROW AFTERNOON AND EVENING...WITH
LARGE HAIL AND DAMAGING WINDS THE BEST THREAT. EVEN AN ISOLATED
TORNADO OR TWO CAN NOT BE RULED OUT.
FINALLY THE SYSTEM WILL MOSTLY PULL OUT ON WEDNESDAY...WITH
PERHAPS SOME LINGERING SHOWERS INTO WEDNESDAY EVENING. TEMPS WILL
COOL OFF INTO THE 70S ON WEDNESDAY...AND EVEN COOLER THURSDAY-
SATURDAY IN THE 60S. CONDITIONS SHOULD MOSTLY BE DRY THURSDAY
ON...WITH TEMPS WARMING BACK UP TO NEAR 80 SUNDAY AND MONDAY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR TNZ005>011-023>034-
056>066-075-077>080-093>095.
&&
$$
21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1245 AM CDT MON APR 28 2014
.UPDATE...FOR 06Z TAFS.
&&
.AVIATION...
SIGNIFICANT SYSTEM TO CROSS THE MID-SOUTH THE NEXT 18-24 HOURS.
SHWRS/STMS EXPECTED TO AFFECT ALL SITES OFF AND ON THROUGH
THE PERIOD...WHICH WILL BRING VARYING CONDITIONS. BEST CHANCE
FOR STRONGEST STORMS LOOKS TO BE THE 18-03Z RANGE MON-TUE. STORMS
WILL CONTAIN VERY HEAVY RAIN WHICH WILL GREATLY REDUCES VSBYS AND
POSSIBLY CIGS. STRONG STMS LIKELY TO CONTAIN 30-40+KT WIND GUSTS
AS WELL.
&&
.PREV DISCUSSION... /ISSUED 1009 PM CDT SUN APR 27 2014/
UPDATE...
SHOWER AND ISOLATED TSTM ACTIVITY NOW CONFINED TO GENERALLY THE
NORTHEASTERN HALF OF THE MID STATE. LATEST HRRR SHOWS
REDEVELOPMENT OVER OUR NORTHWESTERN COUNTIES AROUND 3 OR 4 AM IN
THE MORNING. THE ACTIVITY AT THAT TIME STILL DOES NOT LOOK SEVERE.
ELSEWHERE...JUST SCT ACTIVITY IS POSSIBLE.
MODELS ARE IN AGREEMENT WITH A BUILDUP OF SUBSIDENCE TOWARD 12Z
OVER WESTERN TN. SO...ONSET OF SEVERE MAY HOLD OFF UNTIL AFTER THE
12Z-15Z WINDOW.
FOR THIS NEXT UPDATE...WILL BE LOWERING POPS FOR THE REMAINDER OF
THE OVERNIGHT. BUT...WILL AT LEAST MAINTAIN LIKELY POPS FOR MUCH
OF THE NORTHWEST. ELSEWHERE...WILL GENERALLY KEEP POPS IN THE CHC
CATEGORY.
OTW...LOW TEMPS LOOK FINE AS DEWPOINTS WILL REMAIN NEARLY STEADY.
FOR THE REMAINDER OF THE OVERNIGHT...IT DOES NOT LOOK AS THOUGH ANY
SEVERE WEATHER WILL HIT US. BUT...THAT WILL CHANGE AFTER 12Z-15Z.
PREV DISCUSSION... /ISSUED 805 PM CDT SUN APR 27 2014/
DISCUSSION...
CURRENT RADAR IMAGERY SHOWING A LARGE AMOUNT OF REFLECTIVITY
COVERAGE IN THE FORM OF SHOWERS AND NON SEVERE TSTMS. MODELS SHOW
THAT AN INCREASE IN MOISTURE DEPTH IS EXPECTED THIS EVENING AND
OVERNIGHT. WILL GO AHEAD AND UP POPS AREA WIDE.
OTW...IN TERMS OF THE SEVERE POTENTIAL ANALYSIS...LATEST SOUNDING FOR OHX
IS IN NOW. CURRENT LI IS + 1.8 AND SUPPORTS THE RELATIVELY STABLE
CONDITIONS ACROSS MIDDLE TN AT THIS TIME. THE FURTHER WEST YOU GO
HOWEVER...INSTABILITIES DO INCREASE. THE CLOSEST SEVERE WARNINGS
ARE ACROSS NW MS AND THE BOOTHEEL OF MO. THE ACTIVITY LOOKS
ESPECIALLY NASTY IN THE CENTRAL AR AREA. MODELS IN AGREEMENT AND
SUPPORT INCREASINGLY UNSTABLE AIR THE FURTHER WEST YOU GO.
THROUGH 12Z...WE REALLY SEE NO INCREASE IN INSTABILITY LEVELS OVER
MIDDLE AND EASTERN AREAS OF THE MID STATE. HOWEVER...OVER THE
WESTERN QUARTER OR SO OF MIDDLE TN...WE DO SEE A SUBSTANTIAL
DECREASE IN SHOWALTER VALUES. THE MID AND LOW LEVEL JET DYNAMICS
WILL BE ON THE INCREASE OVER WESTERN TN OVERNIGHT AS WELL. ALL IN
ALL...LOOKS LIKE NON SEVERE TSTMS OVERNIGHT EXCEPT AS WE APPROACH
12Z...THE RISK OF SEVERE WILL BEGIN TO INCREASE OVER OUR FAR
WESTERN AREAS.
AGAIN...WILL UP THE POPS FOR ALL AREAS FOR TONIGHT. UPDATES WILL
BE SENT SHORTLY.
PREV DISCUSSION... /ISSUED 717 PM CDT SUN APR 27 2014/
UPDATE...FOR 00Z TAFS.
AVIATION...
SIGNIFICANT SYSTEM TO CROSS THE MID-SOUTH THE NEXT 24 HOURS.
SHWRS/STMS EXPECTED TO AFFECT ALL SITES OFF AND ON THROUGH
THE PERIOD...WHICH WILL BRING A MULTITUDE OF VARYING CONDITIONS.
BEST CHANCE FOR STRONGEST STORMS LOOKS TO BE THE 15-00Z RANGE
MONDAY. STORMS WILL CONTAIN VERY HEAVY RAIN WHICH WILL GREATLY
REDUCES VSBYS AND POSSIBLY CIGS. STRONG STMS LIKELY TO CONTAIN
40+KT WIND GUSTS AS WELL.
PREV DISCUSSION... /ISSUED 355 PM CDT SUN APR 27 2014/
AS OF 3 PM...ISOLATED SHOWERS AND STORM DEVELOPMENT CONTINUED NORTH
OF THE WARM FRONT AND ITS ASSOCIATED CONVECTION. THE FRONT HAS BEEN
VERY SLUGGISH TO PROGRESS NORTHWARD...AND AS A RESULT...HAS RESULTED
IN SOME FLASH FLOODING CONCERNS IN NORTHERN MS. THIS ACTIVITY SHOULD
CONTINUE TO INCH NORTH THROUGH THE LATE AFTERNOON AND EVENING. STILL
THINK THAT HEAVY RAINS...FREQUENT CG STRIKES...AND SOME SMALL
HAIL/GUSTY WINDS WILL BE THE THREATS UNTIL NIGHTFALL...THEN ACTIVITY
SHOULD MELLOW AS IT EXITS NORTH OF THE STATE LINE.
REGARDING THE FORECAST SEVERE LINE OF STORMS THAT HAS BEEN
ADVERTISED FOR THE LAST FEW DAYS...HRRR/RAP/WRF HI RES MODELS
CONTINUE TO INDICATE A SEVERE LINE OF STORMS THAT SHOULD REACH THE
TN RIVER WELL AFTER MIDNIGHT. ALL THE DETERMINISTIC MODELS BLOW
THIS SQUALL LINE THROUGH THE MID STATE BY LATE MORNING MONDAY.
FOR THE PERIOD 18Z MONDAY THROUGH 06Z TUESDAY...
THIS CONTINUES TO BE THE TIMEFRAME IN WHICH THE HIGHEST POTENTIAL
FOR SEVERE WEATHER APPEARS TO BE. THE POTENTIAL FOR A WIDESPREAD
SEVERE WEATHER OUTBREAK INCLUDING VERY LARGE HAIL AND
STRONG...POTENTIALLY NUMEROUS...TORNADOES CONTINUES TO EXIST.
AFTER CLOSE EXAMINATION OF THE DETERMINISTIC MODELS...THE ONLY
NOTABLE DIFFERENCE FROM PREVIOUS FORECASTS APPEARS TO BE A
SOMEWHAT EARLIER POSSIBLE CONVECTIVE INITIATION TIMING ESTIMATE.
12Z-15Z FORECAST SOUNDINGS INDICATE VERY RAPID WARMING AND RAPIDLY
INCREASING INSTABILITY PARAMETERS FOR THE WESTERN HALF OF THE MID
STATE. SIMULTANEOUSLY...THE RIGHT EXIT REGION OF A 250 MB JET STREAK
WILL BE DEVELOPING OVER THE MS RIVER AND SHOULD BE AROUND THE TN
RIVER BY 18Z. OMEGA FIELDS ECHO THE IMPLIED DEEP LAYER LIFT
DEVELOPING IN WESTERN TN IN THE MORNING AND A VERY STRONG DYNAMIC
AND RAPIDLY DEVELOPING CONVECTIVE SET UP LOOKS TO BE IN STORE FOR
THE WESTERN TN AND WESTERN MIDDLE TENNESSEE AREAS. THE BIGGEST
QUESTION AROUND THIS TIME IS WHERE IN FACT CI WILL TAKE PLACE...AND
INTERROGATING SUBTLETIES IN THE WIND FIELDS OF ALL THE PROGGED SFC
WIND FIELDS...A SUBTLE SURFACE CONFLUENCE ZONE LOCATED JUST WEST OF
THE TN RIVER MAY BE THE LOCATION THAT THIS CI TAKES PLACE.
CONFIDENCE IS QUITE LOW IN THAT REGARD HOWEVER.
AFTER CI TAKES PLACE...THESE CELLS SHOULD BEGIN TAKING SUPERCELL
STRUCTURE AND STEERING FLOW SHOULD BE EAST NORTHEASTERLY AT ABOUT
40-50 KTS. THIS WOULD PUT ALL OF MIDDLE TENNESSEE IN THE PATH OF
VERY STRONG SUPERCELLS SHOULD THIS OUTCOME COME TO FRUITION. IF
EVERYTHING GOES AS INDICATED IN THE MODELS...THE 21Z TO 03Z
TIMEFRAME LOOKS TO BE THE TIMEFRAME OF PEAK THREAT.
OVERALL FORECAST LIMITING FACTORS...SOME OF THE VARIABLES THAT
CONTINUE TO COMPLICATE THE FORECAST. THERE IS LOWER CONFIDENCE IN
THE HI RES MODELS OF LATE DUE TO ITS INABILITY TO ACCURATELY
HANDLE THE CONVECTION FROM TODAY. THIS MAKES THE SQUALL LINE
POTENTIAL FOR TONIGHT MORE QUESTIONABLE HOWEVER THERE ARE STILL A
FEW MORE HOURS OF POTENTIAL DEVELOPMENT OUT WEST.
ADDITIONALLY...THE LARGE AMOUNTS OF RAINFALL THAT HAS BEEN
OBSERVED IN NORTHERN MS AND WESTERN TN MAY KEEP THE LOW LEVEL
ATMOSPHERE QUITE MOIST TOMORROW AND THUS KEEP LOW LEVEL CLOUD
COVER IN THE AREA IF THE PREVIOUSLY FORECAST SQUALL LINE DOES NOT
COME TO FRUITION AND CLEAR EVERYTHING OUT. THIS WOULD RESULT IN
INHIBITED INSTABILITY AND DELAY STORM DEVELOPMENT INTO THE LATER
AFTERNOON. WITH THE MULTITUDE OF VARIABLES UNKNOWN DUE TO ONGOING
CONVECTION...THESE LIMITING FACTORS ARE DIFFICULT TO ASSESS.
ADDITIONALLY...PWAT VALUES SHOULD STAY WELL ABOVE NORMAL THROUGHOUT
THE NEXT 48 HOURS. SO IN ADDITION TO THE SEVERE WEATHER
POTENTIAL...HEAVY RAIN POTENTIAL AND POSSIBLE FLASH FLOODING WILL BE
A SIGNIFICANT THREAT. HPC IS INDICATING AROUND 5 INCHES OF RAIN FROM
00Z TONIGHT THROUGH 00Z WEDNESDAY. NOTE HOWEVER THAT A LARGE PORTION
OF THIS RESTS ON WHETHER TONIGHTS STORM SYSTEM DEVELOPS AS FORECAST
IN THE SHORT RANGE MODELS.
BEYOND 06Z TUESDAY...LEFT FORECAST BASICALLY UNCHANGED WITH
ANOTHER POTENTIAL ROUND OF STRONG TO SEVERE WEATHER POSSIBLE
TUESDAY AFTERNOON AND EVENING. PREFER NOT TO ADD ANY MORE DETAILS
TO THIS FORECAST WITHOUT SEEING HOW TOMORROW UNFOLDS FIRST AS IT
WILL DIRECTLY IMPACT WHAT HAPPENS TUESDAY. BUT FOR WHAT ITS
WORTH...SPC HAS DOWNGRADED TUESDAYS THREAT FOR MIDDLE TENNESSEE TO
ONLY GENERAL THUNDERSTORMS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1243 PM CDT MON APR 28 2014
.DISCUSSION...NOTE AVIATION DISCUSSION BELOW.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED DURING THE TAF PERIOD
EXCEPT FOR MVFR/IFR CONDITIONS GENERALLY EAST OF U.S. ROUTE 281
OWING TO MIST/FOG DRG THE 07-13Z TUESDAY PERIOD. MODERATE NORTH
WIND THIS AFTN BECOMING LIGHT SOUTH/VARIABLE OVERNIGHT THEN
MODERATE NORTH WIND TUESDAY BY MID MORNING IN RESPONSE TO A COLD
FRONT.
&&
.PREV DISCUSSION... /ISSUED 635 AM CDT MON APR 28 2014/
DISCUSSION...SEE 12Z AVIATION DISCUSSION.
AVIATION...LOW CIGS/VSBYS RAPIDLY LIFTING AS WINDS HAVE SHIFTED.
WILL LIKELY JUST HAVE SOME TEMPO CONDITIONS ENDING BY NO LATER
THAN 14Z EASTERN TERMINALS. SHOULD MAINLY HAVE N-NW WINDS
ESPECIALLY BY 14Z WITH MAINLY CLEAR SKIES. SEA-BREEZE COMES IN
AGAIN LATE THIS AFTERNOON AND SHIFT WINDS SOUTHERLY STARTING ABOUT
20Z AT KCRP AND SPREADING WESTWARD. WINDS DIMINISH TONIGHT AND
MAINLY BECOME LIGHT AND VARIABLE OVERNIGHT. COULD HAVE SOME GROUND
FOG KCRP AND KVCT TOWARD END OF TAF PERIOD AS LIGHT WINDS AND
CLEAR SKIES CREATE FOG.
PREV DISCUSSION... /ISSUED 326 AM CDT MON APR 28 2014/
SHORT TERM (TODAY THROUGH TUESDAY)...WARM AND DRY TODAY AND TUESDAY
TOO (MOST AREAS)...AS COLD AIR IS EXPECTED TO LAG BEHIND THE FRONTAL
BOUNDARY ON TUESDAY. LOOKS LIKE ANOTHER HOT DAY...BUT NOT AS HOT AS
YESTERDAY AT LEAST OUT TO THE WEST AS BOUNDARY LAYER TEMPERATURES
ARE PROGGED TO BE SEVERAL DEGREES COOLER (SO IF THAT HAPPENS IT
SHOULD BE COOLER). 4KM RUC IS SHOWING TEMPERATURES TOPPING 100
DEGREE BARRIER OVER THE SOUTHERN AREAS...AND WILL GO 101/102 OVER
THE SOUTHWESTERN AREAS. OTHERWISE...MORNING LOW CLOUDS OVER THE EAST
WILL QUICKLY LIFT AND SHOULD SEE LOTS OF SUN WITH NORTHWEST WINDS AS
DRY LINE MOVES FARTHER EAST THAN YESTERDAY. LOW LEVEL MOISTURE IS
TOO SCOURED OUT FOR ANY MENTION OF RAIN (EVEN OFFSHORE) SO HAVE
REMOVED (4KM MODELS KEEP THINGS DRY TOO). FOR TONIGHT...ONLY NAM IS
BRINGING COOLER AIR MUCH FASTER THAN GFS/ECMWF (ALTHOUGH CANADIAN IS
COOL TOO...AS USUAL). AM GOING TO PREFER TO GO MORE ON THE WARM SIDE
TONIGHT ALTHOUGH IF WINDS ARE TOO LIGHT AND SURFACE MOISTURE IS TOO
LOW...WE COULD REALLY BOTTOM OUT (GIVEN WARM DAY EXPECTED TODAY WILL
PREFER TO STAY ON THE WARM SIDE THOUGH). COOLER AGAIN ON TUESDAY BUT
STILL WARMER THAN NORMAL WITH COLD AIR LAGGING ON FRONT. MAY SEE A
FEW 80S IN THE VICTORIA AREA. MOISTURE AGAIN TOO LIMITED FOR
PRECIPITATION.
MARINE (TODAY THROUGH TUESDAY)...HAVE EXTENDED THE SCA TIL 4 AM FOR
THE BAYS/WATERWAYS...AND LONGER FOR THE GULF WATERS. MAY NEED TO
EXTEND AGAIN AT THE LAST MINUTE IF WINDS STAY UP AGAIN. WINDS HAVE
STAYED UP LONGER THAN EXPECTED WITH GUSTS OVER 30 KNOTS AT KNGP.
4KM RUC HAS WINDS CRANKING TIL 12Z OR SO...BUT THIS IS NORMALLY ON
THE HIGH SIDE (BUT STILL DOING BETTER THAN NAM12 OR OTHER MODELS).
WINDS DO DECREASE BY SUNRISE...BUT SEAS STAY UP. THUS...THE GULF
WATER SCA WILL MAINLY BE FOR HIGH SEAS MONDAY...WITH SCA
CONDITIONS ENDING AROUND NOON. VISIBILITIES OVER THE MARINE AREAS
ARE BETWEEN 1 AND 3 MILES...AND THAT SHOULD CLEAR UP LATER THIS
MORNING. MORE FOG TONIGHT BUT THAT SHOULD BE OVER THE OFFSHORE
WATERS (IF THAT)...AS DRIER AIR DOES GET INTO THE NEARSHORE
WATERS. COULD NOT RULE OUT A ROGUE SHOWER NEAR MATAGORDA ISLAND
BUT THAT WILL BE VERY BRIEF AND UNLIKELY TO HAPPEN (SO NOT IN
FORECAST).
FIRE WEATHER (TODAY THROUGH TUESDAY)...FIRE WEATHER PROCEDURE IS
SHOWING ELEVATED CONDITIONS/ISOLATED CRITICAL OVER MUCH OF THE AREA
ON TUESDAY. FUEL DRYNESS FORECAST MAP IS SHOWING MOST AREAS IN
NORMAL MOISTURE..WITH ONLY A PART OF THE NORTHERN COASTAL BEND (LIVE
OAK AND PORTIONS OF BEE AND MCMULLEN COUNTIES) IN DRY FUELS. SINCE
THESE COUNTIES ARE FORECAST TO BE IN ELEVATED CONDITIONS ON
TUESDAY...NO NEED FOR FIRE WEATHER WATCH OR RED FLAG WARNING. DAY
SHIFT OR NEXT MID SHIFT CAN RE-EVALUATE...ESPECIALLY IF FUEL DRYNESS
MAP CHANGES THE NEXT DAY.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...PERIOD BEGINS WITH
COOLER TEMPERATURES AND DRY CONDITION IN WAKE OF TUESDAY/S/S FROPA.
BROAD LONGWAVE TROUGH CENTERED OVER THE FAR NORTH CENTRAL STATES
WILL KEEP FAIRLY ZONAL FLOW OVER SOUTH TEXAS THROUGH THURSDAY.
TROUGH WILL FINALLY SWING OVER THE REGION THURSDAY NIGHT INTO
FRIDAY. ECMWF CONTINUES TO BE THE WETTER SOLUTION WITH THIS PASSING
WHILE THE GFS/NAM STAY MOSTLY DRY OVERLAND. WHILE THERE IS THE UPPER
LEVEL SUPPORT FOR PERHAPS SOME SPRINKLES AND RAIN TO DEVELOP THERE IS
AN OVERALL LACK OF SUFFICIENT MOISTURE OVER MOST OF THE REGION
EXCEPT IN THE OVER THE OFFSHORE WATERS THURSDAY NIGHT INTO FRIDAY
MORNING. KEPT THE 20 POPS MENTION OVER THE OFFSHORE WATERS FOR
NOW...BUT EVEN THIS MAY BE GOING TOO HIGH. OTHERWISE EXPECT A
CONTINUED DRY FORECAST. TEMPERATURES WILL BE NICELY COOLER (BELOW
AVERAGE) THROUGH THE END OF THE WEEK BEFORE RETURNING TO NORMAL ON
BY THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 66 93 61 80 59 / 0 10 10 10 10
VICTORIA 63 88 55 81 51 / 0 10 10 10 10
LAREDO 69 98 62 86 60 / 0 10 10 10 10
ALICE 64 96 57 83 54 / 0 10 10 10 10
ROCKPORT 67 89 62 79 61 / 0 10 10 10 10
COTULLA 63 92 54 83 54 / 0 0 10 10 10
KINGSVILLE 65 97 60 81 57 / 0 10 10 10 10
NAVY CORPUS 67 87 65 79 65 / 0 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
WC/87...AVIATION
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1212 PM CDT MON APR 28 2014
.AVIATION...
MUCH DRIER AIR IS FILTERING INTO SOUTHEAST TEXAS RESULTING IN MOSTLY
CLEAR SKIES. SOME LOWER CLOUDS ARE EAST OF THE TAF SITES AND ALONG
THE COAST WHERE THE DEEPEST MOISTURE EXISTS...AND THAT IS WHERE THE
HRRR CONTINUES TO WANT TO DEVELOP SOME SHOWERS THIS AFTERNOON. WILL
MONITOR CLOSELY...BUT AT THIS TIME NOT CONFIDENT ENOUGH TO INCLUDE
ANY MENTION IN THE 18Z TAF PACKAGE. THERE IS A CHANCE THAT ENOUGH
MOISTURE COULD BE PRESENT OVERNIGHT FOR POSSIBLE LOW CLOUD AND FOG
DEVELOPMENT...FROM ROUGHLY CXO SOUTHWARD TO THE COAST. FOR NOW...WILL
ONLY MENTION THIS IN THE CXO AND LBX TAFS WHERE MODELS ARE HITTING
IT THE HARDEST. STRONG COLD FRONT WILL MOVE ACROSS SOUTHEAST TEXAS
TOMORROW MORNING AND OFF THE COAST LATE IN THE MORNING OR EARLY IN
THE AFTERNOON WITH GUSTY NORTH TO NORTHWEST WINDS BEHIND THE BOUNDARY.
NO SHOWERS OR THUNDERTORMS ARE EXPECTED WITH THE FRONT. 42
&&
.PREV DISCUSSION... /ISSUED 1058 AM CDT MON APR 28 2014/
DISCUSSION...
ADDED CLIMATE SECTION.
CLIMATE...
HIGH TEMPERATURES TODAY WILL LIKELY REACH 90 DEGREES. THE LAST
TIME THE CITY OF HOUSTON (KIAH) REACH 90 DEGREES WAS OCTOBER 5TH
OF LAST YEAR (93). THE LAST TIME COLLEGE STATION (CLL) REACHED 90
DEGREES WAS OCTOBER 1ST OF LAST YEAR (91). HERE ARE THE RECORDS
FOR THE THREE FIRST ORDER CLIMATE SITES FOR TODAY WITH THEIR
FORECASTED HIGHS TO THE FAR RIGHT:
CLL (COLLEGE STATION) : 94 (1987) || 91
IAH (CITY OF HOUSTON) : 95 (1987) || 92
GLS (CITY OF GALVESTON):87 (1987) || 84
PREV DISCUSSION... /ISSUED 1038 AM CDT MON APR 28 2014/
UPDATE...
SEE DISCUSSION FOR MORNING UPDATE.
DISCUSSION...
PRECIP HAS COME TO AN END ACROSS MOST OF THE AREA THIS MORNING AS
DRIER AIR WORKS ITS WAY IN FROM THE WEST. HRRR SHOWS A CELL OR TWO
TRYING TO DEVELOP IN CHAMBERS COUNTY AS THE DRY LINE STALLS NEAR
THE COAST THIS AFTERNOON. THE TORNADO WATCH FOR THE AREA WILL BE
ALLOWED TO CONTINUE UNTIL 17Z.
BEHIND THE DRY LINE LIGHT NORTHWEST WINDS... LITTLE CLOUD COVER
AND DRY AIR WILL HELP THE AREA TO QUICKLY HEAT UP. CURRENT AMDAR
SOUNDING FOR HOUSTON SUPPORTS TEMPERATURES IN THE LOWER 90S. MOST
OF THE AREA IS ALREADY AT OR SLIGHTLY ABOVE 80. 90 DEGREES LOOKS
POSSIBLE FOR MOST SITES ACROSS THE AREA (MINUS NORTHEAST COUNTIES
AND AT THE COAST). NUDGED MAX TEMPERATURE GRID UP SLIGHTLY FOR
THIS AFTERNOON. ALSO TRIMMED POPS BACK AS THE CHANCE FOR
CONVECTION APPEARS TO BE COMING TO AN END. NO OTHER CHANGES TO
GRIDS AT THIS TIME. 23
PREV DISCUSSION... /ISSUED 421 AM CDT MON APR 28 2014/
DISCUSSION...
BKN LINE OF TSTMS HAS DEVELOPED SEVERAL MILES AHEAD OF THE SFC
TROF EXTENDING FROM NORTHEAST TEXAS AND INTO NORTHERN PARTS OF SE
TX. NO REPORTS OF SEVERE WX IN OUR CWA JUST YET BUT WOULD BE
SURPRISED IF NO HAIL IS EVENTUALLY REPORTED FROM HOUSTON COUNTY W/
THOSE STORMS. THINK MAJORITY OF THESE WILL REMAIN ELEVATED SO
HAIL WILL BE PRIMARY THREAT. HRRR MODEL HAS BEEN DOING A GOOD JOB
IN THE PAST 24 HOURS AND HAS CONTINUED DOING WELL WITH CURRENT
TRENDS. IT SHOWS THIS PRECIPITATION MAKING ITS WAY SEWD TOWARD THE
UPPER TX COAST IN THE NEXT 6 HOURS SO HAVE BUMPED POPS UP ACROSS A
GOOD PART OF THE AREA. SFC TROF WILL MAKE IT ALMOST TO THE COAST
BY LATE MORNING ENDING PRECIP CHANCES AND BRINGING A DRY AIRMASS
INTO MOST OF THE AREA. THIS DRY AIRMASS AND SUNSHINE SHOULD ALLOW
FOR A RAPID WARM UP ACROSS THE AREA THIS AFTN.
SFC TROF MOVES BACK NORTH LATE TONIGHT AND BECOME OVERTAKEN BY THE
PRIMARY COLD FRONT THAT WILL PUSH ACROSS THE AREA DURING THE DAY
TUE. CURRENT GUIDANCE COMING IN A TOUCH COOLER THAN EARLIER FCSTS
SO NUDGED HIGHS/LOWS DOWN A BIT FOR THE NEXT SEVERAL DAYS.
THRU LATE WEEK WE SHOULD STILL BE IN A WSW FLOW ALOFT UNDER BROAD
UPPER TROF SITUATED ACROSS CNTL PARTS OF THE COUNTRY. MAY SEE
PERIODS OF HIGH CLOUDINESS BUT MEAGER LLVL MOISTURE LEVELS SHOULD
KEEP THINGS MOSTLY DRY. SHOULD TRANSITION TO A DRY NW FLOW LATE IN
THE WEEK AND EARLY WEEKEND AS UPPER TROF MOVES EWD. OTHERWISE...LOOKS
QUITE DRY THRU THE 1ST WEEK OF MAY. 47
MARINE...
WILL EXTEND THE CURRENT ADVISORIES OVER THE COASTAL WATERS/CAUTION
FLAGS ON THE BAYS INTO THE MID MORNING HRS BASED ON CURRENT TRENDS.
GRADIENT STILL EXPECTED TO WEAKEN BY THE AFTN WITH THE APPROACH OF
THE PACIFIC FRONT FROM THE WEST. AS THIS BOUNDARY STALLS ALONG THE
COASTLINE...WINDS SHOULD REMAIN OUT OF THE SW/S THROUGH THE DAY/TO-
NIGHT. THE MAIN PUSH OF STRONG NORTH WINDS STILL FCST FOR TUE AFTN
WITH THE CANADIAN COLD FRONT. BEHIND THIS FRONT...CAUTION/ADVISORY
FLAGS WILL BE LIKELY FROM TUE NIGHT INTO WEDS NIGHT. THIS OFFSHORE
FLOW COULD EXTEND THROUGH THE END OF THE WEEK. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 91 59 82 51 75 / 10 10 10 0 0
HOUSTON (IAH) 92 62 86 55 78 / 20 10 10 0 0
GALVESTON (GLS) 84 71 84 62 77 / 20 10 20 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 2 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: 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...23
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1058 AM CDT MON APR 28 2014
.DISCUSSION...
ADDED CLIMATE SECTION.
&&
.CLIMATE...
HIGH TEMPERATURES TODAY WILL LIKELY REACH 90 DEGREES. THE LAST
TIME THE CITY OF HOUSTON (KIAH) REACH 90 DEGREES WAS OCTOBER 5TH
OF LAST YEAR (93). THE LAST TIME COLLEGE STATION (CLL) REACHED 90
DEGREES WAS OCTOBER 1ST OF LAST YEAR (91). HERE ARE THE RECORDS
FOR THE THREE FIRST ORDER CLIMATE SITES FOR TODAY WITH THEIR
FORECASTED HIGHS TO THE FAR RIGHT:
CLL (COLLEGE STATION) : 94 (1987) || 91
IAH (CITY OF HOUSTON) : 95 (1987) || 92
GLS (CITY OF GALVESTON):87 (1987) || 84
&&
.PREV DISCUSSION... /ISSUED 1038 AM CDT MON APR 28 2014/
UPDATE...
SEE DISCUSSION FOR MORNING UPDATE.
DISCUSSION...
PRECIP HAS COME TO AN END ACROSS MOST OF THE AREA THIS MORNING AS
DRIER AIR WORKS ITS WAY IN FROM THE WEST. HRRR SHOWS A CELL OR TWO
TRYING TO DEVELOP IN CHAMBERS COUNTY AS THE DRY LINE STALLS NEAR
THE COAST THIS AFTERNOON. THE TORNADO WATCH FOR THE AREA WILL BE
ALLOWED TO CONTINUE UNTIL 17Z.
BEHIND THE DRY LINE LIGHT NORTHWEST WINDS... LITTLE CLOUD COVER
AND DRY AIR WILL HELP THE AREA TO QUICKLY HEAT UP. CURRENT AMDAR
SOUNDING FOR HOUSTON SUPPORTS TEMPERATURES IN THE LOWER 90S. MOST
OF THE AREA IS ALREADY AT OR SLIGHTLY ABOVE 80. 90 DEGREES LOOKS
POSSIBLE FOR MOST SITES ACROSS THE AREA (MINUS NORTHEAST COUNTIES
AND AT THE COAST). NUDGED MAX TEMPERATURE GRID UP SLIGHTLY FOR
THIS AFTERNOON. ALSO TRIMMED POPS BACK AS THE CHANCE FOR
CONVECTION APPEARS TO BE COMING TO AN END. NO OTHER CHANGES TO
GRIDS AT THIS TIME. 23
PREV DISCUSSION... /ISSUED 421 AM CDT MON APR 28 2014/
DISCUSSION...
BKN LINE OF TSTMS HAS DEVELOPED SEVERAL MILES AHEAD OF THE SFC
TROF EXTENDING FROM NORTHEAST TEXAS AND INTO NORTHERN PARTS OF SE
TX. NO REPORTS OF SEVERE WX IN OUR CWA JUST YET BUT WOULD BE
SURPRISED IF NO HAIL IS EVENTUALLY REPORTED FROM HOUSTON COUNTY W/
THOSE STORMS. THINK MAJORITY OF THESE WILL REMAIN ELEVATED SO
HAIL WILL BE PRIMARY THREAT. HRRR MODEL HAS BEEN DOING A GOOD JOB
IN THE PAST 24 HOURS AND HAS CONTINUED DOING WELL WITH CURRENT
TRENDS. IT SHOWS THIS PRECIPITATION MAKING ITS WAY SEWD TOWARD THE
UPPER TX COAST IN THE NEXT 6 HOURS SO HAVE BUMPED POPS UP ACROSS A
GOOD PART OF THE AREA. SFC TROF WILL MAKE IT ALMOST TO THE COAST
BY LATE MORNING ENDING PRECIP CHANCES AND BRINGING A DRY AIRMASS
INTO MOST OF THE AREA. THIS DRY AIRMASS AND SUNSHINE SHOULD ALLOW
FOR A RAPID WARM UP ACROSS THE AREA THIS AFTN.
SFC TROF MOVES BACK NORTH LATE TONIGHT AND BECOME OVERTAKEN BY THE
PRIMARY COLD FRONT THAT WILL PUSH ACROSS THE AREA DURING THE DAY
TUE. CURRENT GUIDANCE COMING IN A TOUCH COOLER THAN EARLIER FCSTS
SO NUDGED HIGHS/LOWS DOWN A BIT FOR THE NEXT SEVERAL DAYS.
THRU LATE WEEK WE SHOULD STILL BE IN A WSW FLOW ALOFT UNDER BROAD
UPPER TROF SITUATED ACROSS CNTL PARTS OF THE COUNTRY. MAY SEE
PERIODS OF HIGH CLOUDINESS BUT MEAGER LLVL MOISTURE LEVELS SHOULD
KEEP THINGS MOSTLY DRY. SHOULD TRANSITION TO A DRY NW FLOW LATE IN
THE WEEK AND EARLY WEEKEND AS UPPER TROF MOVES EWD. OTHERWISE...LOOKS
QUITE DRY THRU THE 1ST WEEK OF MAY. 47
MARINE...
WILL EXTEND THE CURRENT ADVISORIES OVER THE COASTAL WATERS/CAUTION
FLAGS ON THE BAYS INTO THE MID MORNING HRS BASED ON CURRENT TRENDS.
GRADIENT STILL EXPECTED TO WEAKEN BY THE AFTN WITH THE APPROACH OF
THE PACIFIC FRONT FROM THE WEST. AS THIS BOUNDARY STALLS ALONG THE
COASTLINE...WINDS SHOULD REMAIN OUT OF THE SW/S THROUGH THE DAY/TO-
NIGHT. THE MAIN PUSH OF STRONG NORTH WINDS STILL FCST FOR TUE AFTN
WITH THE CANADIAN COLD FRONT. BEHIND THIS FRONT...CAUTION/ADVISORY
FLAGS WILL BE LIKELY FROM TUE NIGHT INTO WEDS NIGHT. THIS OFFSHORE
FLOW COULD EXTEND THROUGH THE END OF THE WEEK. 41
AVIATION...
HAVING TO KEEP AN EYE ON DEVELOPMENT OUT TO OUR W/NW THRU THE MORN-
ING HOURS. PROBABLY CANNOT AVOID THE MENTION OF THUNDER IN THE NRN
HALF TAF SITES (CLL/UTS/CXO/IAH) THIS MORNING UNTIL THIS AFTN. THE
APPROACH/PASSAGE OF THE PACIFIC FRONT (IN WHICH THIS PCPN IS FOCUS-
ING ON) SHOULD BRING DRIER AIR AND VFR CONDITIONS TO THE AREA LATE
THIS AFTN/TONIGHT. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 91 59 82 51 75 / 10 10 10 0 0
HOUSTON (IAH) 92 62 86 55 78 / 20 10 10 0 0
GALVESTON (GLS) 84 71 84 62 77 / 20 10 20 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 2 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: 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/CLIMATE...23
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1038 AM CDT MON APR 28 2014
.UPDATE...
SEE DISCUSSION FOR MORNING UPDATE.
&&
.DISCUSSION...
PRECIP HAS COME TO AN END ACROSS MOST OF THE AREA THIS MORNING AS
DRIER AIR WORKS ITS WAY IN FROM THE WEST. HRRR SHOWS A CELL OR TWO
TRYING TO DEVELOP IN CHAMBERS COUNTY AS THE DRY LINE STALLS NEAR
THE COAST THIS AFTERNOON. THE TORNADO WATCH FOR THE AREA WILL BE
ALLOWED TO CONTINUE UNTIL 17Z.
BEHIND THE DRY LINE LIGHT NORTHWEST WINDS... LITTLE CLOUD COVER
AND DRY AIR WILL HELP THE AREA TO QUICKLY HEAT UP. CURRENT AMDAR
SOUNDING FOR HOUSTON SUPPORTS TEMPERATURES IN THE LOWER 90S. MOST
OF THE AREA IS ALREADY AT OR SLIGHTLY ABOVE 80. 90 DEGREES LOOKS
POSSIBLE FOR MOST SITES ACROSS THE AREA (MINUS NORTHEAST COUNTIES
AND AT THE COAST). NUDGED MAX TEMPERATURE GRID UP SLIGHTLY FOR
THIS AFTERNOON. ALSO TRIMMED POPS BACK AS THE CHANCE FOR
CONVECTION APPEARS TO BE COMING TO AN END. NO OTHER CHANGES TO
GRIDS AT THIS TIME. 23
&&
.PREV DISCUSSION... /ISSUED 421 AM CDT MON APR 28 2014/
DISCUSSION...
BKN LINE OF TSTMS HAS DEVELOPED SEVERAL MILES AHEAD OF THE SFC
TROF EXTENDING FROM NORTHEAST TEXAS AND INTO NORTHERN PARTS OF SE
TX. NO REPORTS OF SEVERE WX IN OUR CWA JUST YET BUT WOULD BE
SURPRISED IF NO HAIL IS EVENTUALLY REPORTED FROM HOUSTON COUNTY W/
THOSE STORMS. THINK MAJORITY OF THESE WILL REMAIN ELEVATED SO
HAIL WILL BE PRIMARY THREAT. HRRR MODEL HAS BEEN DOING A GOOD JOB
IN THE PAST 24 HOURS AND HAS CONTINUED DOING WELL WITH CURRENT
TRENDS. IT SHOWS THIS PRECIPITATION MAKING ITS WAY SEWD TOWARD THE
UPPER TX COAST IN THE NEXT 6 HOURS SO HAVE BUMPED POPS UP ACROSS A
GOOD PART OF THE AREA. SFC TROF WILL MAKE IT ALMOST TO THE COAST
BY LATE MORNING ENDING PRECIP CHANCES AND BRINGING A DRY AIRMASS
INTO MOST OF THE AREA. THIS DRY AIRMASS AND SUNSHINE SHOULD ALLOW
FOR A RAPID WARM UP ACROSS THE AREA THIS AFTN.
SFC TROF MOVES BACK NORTH LATE TONIGHT AND BECOME OVERTAKEN BY THE
PRIMARY COLD FRONT THAT WILL PUSH ACROSS THE AREA DURING THE DAY
TUE. CURRENT GUIDANCE COMING IN A TOUCH COOLER THAN EARLIER FCSTS
SO NUDGED HIGHS/LOWS DOWN A BIT FOR THE NEXT SEVERAL DAYS.
THRU LATE WEEK WE SHOULD STILL BE IN A WSW FLOW ALOFT UNDER BROAD
UPPER TROF SITUATED ACROSS CNTL PARTS OF THE COUNTRY. MAY SEE
PERIODS OF HIGH CLOUDINESS BUT MEAGER LLVL MOISTURE LEVELS SHOULD
KEEP THINGS MOSTLY DRY. SHOULD TRANSITION TO A DRY NW FLOW LATE IN
THE WEEK AND EARLY WEEKEND AS UPPER TROF MOVES EWD. OTHERWISE...LOOKS
QUITE DRY THRU THE 1ST WEEK OF MAY. 47
MARINE...
WILL EXTEND THE CURRENT ADVISORIES OVER THE COASTAL WATERS/CAUTION
FLAGS ON THE BAYS INTO THE MID MORNING HRS BASED ON CURRENT TRENDS.
GRADIENT STILL EXPECTED TO WEAKEN BY THE AFTN WITH THE APPROACH OF
THE PACIFIC FRONT FROM THE WEST. AS THIS BOUNDARY STALLS ALONG THE
COASTLINE...WINDS SHOULD REMAIN OUT OF THE SW/S THROUGH THE DAY/TO-
NIGHT. THE MAIN PUSH OF STRONG NORTH WINDS STILL FCST FOR TUE AFTN
WITH THE CANADIAN COLD FRONT. BEHIND THIS FRONT...CAUTION/ADVISORY
FLAGS WILL BE LIKELY FROM TUE NIGHT INTO WEDS NIGHT. THIS OFFSHORE
FLOW COULD EXTEND THROUGH THE END OF THE WEEK. 41
AVIATION...
HAVING TO KEEP AN EYE ON DEVELOPMENT OUT TO OUR W/NW THRU THE MORN-
ING HOURS. PROBABLY CANNOT AVOID THE MENTION OF THUNDER IN THE NRN
HALF TAF SITES (CLL/UTS/CXO/IAH) THIS MORNING UNTIL THIS AFTN. THE
APPROACH/PASSAGE OF THE PACIFIC FRONT (IN WHICH THIS PCPN IS FOCUS-
ING ON) SHOULD BRING DRIER AIR AND VFR CONDITIONS TO THE AREA LATE
THIS AFTN/TONIGHT. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 91 59 82 51 75 / 10 10 10 0 0
HOUSTON (IAH) 92 62 86 55 78 / 20 10 10 0 0
GALVESTON (GLS) 84 71 84 62 77 / 20 10 20 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 2 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: 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...23
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
635 AM CDT MON APR 28 2014
.DISCUSSION...SEE 12Z AVIATION DISCUSSION.
&&
.AVIATION...LOW CIGS/VSBYS RAPIDLY LIFTING AS WINDS HAVE SHIFTED.
WILL LIKELY JUST HAVE SOME TEMPO CONDITIONS ENDING BY NO LATER
THAN 14Z EASTERN TERMINALS. SHOULD MAINLY HAVE N-NW WINDS
ESPECIALLY BY 14Z WITH MAINLY CLEAR SKIES. SEA-BREEZE COMES IN
AGAIN LATE THIS AFTERNOON AND SHIFT WINDS SOUTHERLY STARTING ABOUT
20Z AT KCRP AND SPREADING WESTWARD. WINDS DIMINISH TONIGHT AND
MAINLY BECOME LIGHT AND VARIABLE OVERNIGHT. COULD HAVE SOME GROUND
FOG KCRP AND KVCT TOWARD END OF TAF PERIOD AS LIGHT WINDS AND
CLEAR SKIES CREATE FOG.
&&
.PREV DISCUSSION... /ISSUED 326 AM CDT MON APR 28 2014/
SHORT TERM (TODAY THROUGH TUESDAY)...WARM AND DRY TODAY AND TUESDAY
TOO (MOST AREAS)...AS COLD AIR IS EXPECTED TO LAG BEHIND THE FRONTAL
BOUNDARY ON TUESDAY. LOOKS LIKE ANOTHER HOT DAY...BUT NOT AS HOT AS
YESTERDAY AT LEAST OUT TO THE WEST AS BOUNDARY LAYER TEMPERATURES
ARE PROGGED TO BE SEVERAL DEGREES COOLER (SO IF THAT HAPPENS IT
SHOULD BE COOLER). 4KM RUC IS SHOWING TEMPERATURES TOPPING 100
DEGREE BARRIER OVER THE SOUTHERN AREAS...AND WILL GO 101/102 OVER
THE SOUTHWESTERN AREAS. OTHERWISE...MORNING LOW CLOUDS OVER THE EAST
WILL QUICKLY LIFT AND SHOULD SEE LOTS OF SUN WITH NORTHWEST WINDS AS
DRY LINE MOVES FARTHER EAST THAN YESTERDAY. LOW LEVEL MOISTURE IS
TOO SCOURED OUT FOR ANY MENTION OF RAIN (EVEN OFFSHORE) SO HAVE
REMOVED (4KM MODELS KEEP THINGS DRY TOO). FOR TONIGHT...ONLY NAM IS
BRINGING COOLER AIR MUCH FASTER THAN GFS/ECMWF (ALTHOUGH CANADIAN IS
COOL TOO...AS USUAL). AM GOING TO PREFER TO GO MORE ON THE WARM SIDE
TONIGHT ALTHOUGH IF WINDS ARE TOO LIGHT AND SURFACE MOISTURE IS TOO
LOW...WE COULD REALLY BOTTOM OUT (GIVEN WARM DAY EXPECTED TODAY WILL
PREFER TO STAY ON THE WARM SIDE THOUGH). COOLER AGAIN ON TUESDAY BUT
STILL WARMER THAN NORMAL WITH COLD AIR LAGGING ON FRONT. MAY SEE A
FEW 80S IN THE VICTORIA AREA. MOISTURE AGAIN TOO LIMITED FOR
PRECIPITATION.
MARINE (TODAY THROUGH TUESDAY)...HAVE EXTENDED THE SCA TIL 4 AM FOR
THE BAYS/WATERWAYS...AND LONGER FOR THE GULF WATERS. MAY NEED TO
EXTEND AGAIN AT THE LAST MINUTE IF WINDS STAY UP AGAIN. WINDS HAVE
STAYED UP LONGER THAN EXPECTED WITH GUSTS OVER 30 KNOTS AT KNGP.
4KM RUC HAS WINDS CRANKING TIL 12Z OR SO...BUT THIS IS NORMALLY ON
THE HIGH SIDE (BUT STILL DOING BETTER THAN NAM12 OR OTHER MODELS).
WINDS DO DECREASE BY SUNRISE...BUT SEAS STAY UP. THUS...THE GULF
WATER SCA WILL MAINLY BE FOR HIGH SEAS MONDAY...WITH SCA
CONDITIONS ENDING AROUND NOON. VISIBILITIES OVER THE MARINE AREAS
ARE BETWEEN 1 AND 3 MILES...AND THAT SHOULD CLEAR UP LATER THIS
MORNING. MORE FOG TONIGHT BUT THAT SHOULD BE OVER THE OFFSHORE
WATERS (IF THAT)...AS DRIER AIR DOES GET INTO THE NEARSHORE
WATERS. COULD NOT RULE OUT A ROGUE SHOWER NEAR MATAGORDA ISLAND
BUT THAT WILL BE VERY BRIEF AND UNLIKELY TO HAPPEN (SO NOT IN
FORECAST).
FIRE WEATHER (TODAY THROUGH TUESDAY)...FIRE WEATHER PROCEDURE IS
SHOWING ELEVATED CONDITIONS/ISOLATED CRITICAL OVER MUCH OF THE AREA
ON TUESDAY. FUEL DRYNESS FORECAST MAP IS SHOWING MOST AREAS IN
NORMAL MOISTURE..WITH ONLY A PART OF THE NORTHERN COASTAL BEND (LIVE
OAK AND PORTIONS OF BEE AND MCMULLEN COUNTIES) IN DRY FUELS. SINCE
THESE COUNTIES ARE FORECAST TO BE IN ELEVATED CONDITIONS ON
TUESDAY...NO NEED FOR FIRE WEATHER WATCH OR RED FLAG WARNING. DAY
SHIFT OR NEXT MID SHIFT CAN RE-EVALUATE...ESPECIALLY IF FUEL DRYNESS
MAP CHANGES THE NEXT DAY.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...PERIOD BEGINS WITH
COOLER TEMPERATURES AND DRY CONDITION IN WAKE OF TUESDAY/S/S FROPA.
BROAD LONGWAVE TROUGH CENTERED OVER THE FAR NORTH CENTRAL STATES
WILL KEEP FAIRLY ZONAL FLOW OVER SOUTH TEXAS THROUGH THURSDAY.
TROUGH WILL FINALLY SWING OVER THE REGION THURSDAY NIGHT INTO
FRIDAY. ECMWF CONTINUES TO BE THE WETTER SOLUTION WITH THIS PASSING
WHILE THE GFS/NAM STAY MOSTLY DRY OVERLAND. WHILE THERE IS THE UPPER
LEVEL SUPPORT FOR PERHAPS SOME SPRINKLES AND RAIN TO DEVELOP THERE IS
AN OVERALL LACK OF SUFFICIENT MOISTURE OVER MOST OF THE REGION
EXCEPT IN THE OVER THE OFFSHORE WATERS THURSDAY NIGHT INTO FRIDAY
MORNING. KEPT THE 20 POPS MENTION OVER THE OFFSHORE WATERS FOR
NOW...BUT EVEN THIS MAY BE GOING TOO HIGH. OTHERWISE EXPECT A
CONTINUED DRY FORECAST. TEMPERATURES WILL BE NICELY COOLER (BELOW
AVERAGE) THROUGH THE END OF THE WEEK BEFORE RETURNING TO NORMAL ON
BY THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 99 66 93 61 80 / 10 0 10 10 10
VICTORIA 93 63 88 55 81 / 10 0 10 10 10
LAREDO 104 69 98 62 86 / 0 0 10 10 10
ALICE 102 64 96 57 83 / 10 0 10 10 10
ROCKPORT 92 67 89 62 79 / 10 0 10 10 10
COTULLA 98 63 92 54 83 / 0 0 0 10 10
KINGSVILLE 102 65 97 60 81 / 10 0 10 10 10
NAVY CORPUS 90 67 87 65 79 / 10 0 10 10 10
&&
.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.
SMALL CRAFT ADVISORY UNTIL 11 AM CDT THIS MORNING FOR THE
FOLLOWING ZONES: 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.
&&
$$
GW/86...AVIATION
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
421 AM CDT MON APR 28 2014
.DISCUSSION...
BKN LINE OF TSTMS HAS DEVELOPED SEVERAL MILES AHEAD OF THE SFC
TROF EXTENDING FROM NORTHEAST TEXAS AND INTO NORTHERN PARTS OF SE
TX. NO REPORTS OF SEVERE WX IN OUR CWA JUST YET BUT WOULD BE
SURPRISED IF NO HAIL IS EVENTUALLY REPORTED FROM HOUSTON COUNTY W/
THOSE STORMS. THINK MAJORITY OF THESE WILL REMAIN ELEVATED SO
HAIL WILL BE PRIMARY THREAT. HRRR MODEL HAS BEEN DOING A GOOD JOB
IN THE PAST 24 HOURS AND HAS CONTINUED DOING WELL WITH CURRENT
TRENDS. IT SHOWS THIS PRECIPITATION MAKING ITS WAY SEWD TOWARD THE
UPPER TX COAST IN THE NEXT 6 HOURS SO HAVE BUMPED POPS UP ACROSS A
GOOD PART OF THE AREA. SFC TROF WILL MAKE IT ALMOST TO THE COAST
BY LATE MORNING ENDING PRECIP CHANCES AND BRINGING A DRY AIRMASS
INTO MOST OF THE AREA. THIS DRY AIRMASS AND SUNSHINE SHOULD ALLOW
FOR A RAPID WARM UP ACROSS THE AREA THIS AFTN.
SFC TROF MOVES BACK NORTH LATE TONIGHT AND BECOME OVERTAKEN BY THE
PRIMARY COLD FRONT THAT WILL PUSH ACROSS THE AREA DURING THE DAY
TUE. CURRENT GUIDANCE COMING IN A TOUCH COOLER THAN EARLIER FCSTS
SO NUDGED HIGHS/LOWS DOWN A BIT FOR THE NEXT SEVERAL DAYS.
THRU LATE WEEK WE SHOULD STILL BE IN A WSW FLOW ALOFT UNDER BROAD
UPPER TROF SITUATED ACROSS CNTL PARTS OF THE COUNTRY. MAY SEE
PERIODS OF HIGH CLOUDINESS BUT MEAGER LLVL MOISTURE LEVELS SHOULD
KEEP THINGS MOSTLY DRY. SHOULD TRANSITION TO A DRY NW FLOW LATE IN
THE WEEK AND EARLY WEEKEND AS UPPER TROF MOVES EWD. OTHERWISE...LOOKS
QUITE DRY THRU THE 1ST WEEK OF MAY. 47
&&
.MARINE...
WILL EXTEND THE CURRENT ADVISORIES OVER THE COASTAL WATERS/CAUTION
FLAGS ON THE BAYS INTO THE MID MORNING HRS BASED ON CURRENT TRENDS.
GRADIENT STILL EXPECTED TO WEAKEN BY THE AFTN WITH THE APPROACH OF
THE PACIFIC FRONT FROM THE WEST. AS THIS BOUNDARY STALLS ALONG THE
COASTLINE...WINDS SHOULD REMAIN OUT OF THE SW/S THROUGH THE DAY/TO-
NIGHT. THE MAIN PUSH OF STRONG NORTH WINDS STILL FCST FOR TUE AFTN
WITH THE CANADIAN COLD FRONT. BEHIND THIS FRONT...CAUTION/ADVISORY
FLAGS WILL BE LIKELY FROM TUE NIGHT INTO WEDS NIGHT. THIS OFFSHORE
FLOW COULD EXTEND THROUGH THE END OF THE WEEK. 41
&&
.AVIATION...
HAVING TO KEEP AN EYE ON DEVELOPMENT OUT TO OUR W/NW THRU THE MORN-
ING HOURS. PROBABLY CANNOT AVOID THE MENTION OF THUNDER IN THE NRN
HALF TAF SITES (CLL/UTS/CXO/IAH) THIS MORNING UNTIL THIS AFTN. THE
APPROACH/PASSAGE OF THE PACIFIC FRONT (IN WHICH THIS PCPN IS FOCUS-
ING ON) SHOULD BRING DRIER AIR AND VFR CONDITIONS TO THE AREA LATE
THIS AFTN/TONIGHT. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 90 59 82 51 75 / 20 10 10 0 0
HOUSTON (IAH) 91 62 86 55 78 / 50 10 10 0 0
GALVESTON (GLS) 84 71 84 62 77 / 50 10 20 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 7 AM CDT THIS MORNING
FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 7 AM CDT THIS MORNING FOR THE
FOLLOWING ZONES: 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
NWS CORPUS CHRISTI TX
326 AM CDT MON APR 28 2014
.SHORT TERM (TODAY THROUGH TUESDAY)...WARM AND DRY TODAY AND TUESDAY
TOO (MOST AREAS)...AS COLD AIR IS EXPECTED TO LAG BEHIND THE FRONTAL
BOUNDARY ON TUESDAY. LOOKS LIKE ANOTHER HOT DAY...BUT NOT AS HOT AS
YESTERDAY AT LEAST OUT TO THE WEST AS BOUNDARY LAYER TEMPERATURES
ARE PROGGED TO BE SEVERAL DEGREES COOLER (SO IF THAT HAPPENS IT
SHOULD BE COOLER). 4KM RUC IS SHOWING TEMPERATURES TOPPING 100
DEGREE BARRIER OVER THE SOUTHERN AREAS...AND WILL GO 101/102 OVER
THE SOUTHWESTERN AREAS. OTHERWISE...MORNING LOW CLOUDS OVER THE EAST
WILL QUICKLY LIFT AND SHOULD SEE LOTS OF SUN WITH NORTHWEST WINDS AS
DRY LINE MOVES FARTHER EAST THAN YESTERDAY. LOW LEVEL MOISTURE IS
TOO SCOURED OUT FOR ANY MENTION OF RAIN (EVEN OFFSHORE) SO HAVE
REMOVED (4KM MODELS KEEP THINGS DRY TOO). FOR TONIGHT...ONLY NAM IS
BRINGING COOLER AIR MUCH FASTER THAN GFS/ECMWF (ALTHOUGH CANADIAN IS
COOL TOO...AS USUAL). AM GOING TO PREFER TO GO MORE ON THE WARM SIDE
TONIGHT ALTHOUGH IF WINDS ARE TOO LIGHT AND SURFACE MOISTURE IS TOO
LOW...WE COULD REALLY BOTTOM OUT (GIVEN WARM DAY EXPECTED TODAY WILL
PREFER TO STAY ON THE WARM SIDE THOUGH). COOLER AGAIN ON TUESDAY BUT
STILL WARMER THAN NORMAL WITH COLD AIR LAGGING ON FRONT. MAY SEE A
FEW 80S IN THE VICTORIA AREA. MOISTURE AGAIN TOO LIMITED FOR
PRECIPITATION.
&&
.MARINE (TODAY THROUGH TUESDAY)...HAVE EXTENDED THE SCA TIL 4 AM FOR
THE BAYS/WATERWAYS...AND LONGER FOR THE GULF WATERS. MAY NEED TO
EXTEND AGAIN AT THE LAST MINUTE IF WINDS STAY UP AGAIN. WINDS HAVE
STAYED UP LONGER THAN EXPECTED WITH GUSTS OVER 30 KNOTS AT KNGP.
4KM RUC HAS WINDS CRANKING TIL 12Z OR SO...BUT THIS IS NORMALLY ON
THE HIGH SIDE (BUT STILL DOING BETTER THAN NAM12 OR OTHER MODELS).
WINDS DO DECREASE BY SUNRISE...BUT SEAS STAY UP. THUS...THE GULF
WATER SCA WILL MAINLY BE FOR HIGH SEAS MONDAY...WITH SCA
CONDITIONS ENDING AROUND NOON. VISIBILITIES OVER THE MARINE AREAS
ARE BETWEEN 1 AND 3 MILES...AND THAT SHOULD CLEAR UP LATER THIS
MORNING. MORE FOG TONIGHT BUT THAT SHOULD BE OVER THE OFFSHORE
WATERS (IF THAT)...AS DRIER AIR DOES GET INTO THE NEARSHORE
WATERS. COULD NOT RULE OUT A ROGUE SHOWER NEAR MATAGORDA ISLAND
BUT THAT WILL BE VERY BRIEF AND UNLIKELY TO HAPPEN (SO NOT IN
FORECAST).
&&
.FIRE WEATHER (TODAY THROUGH TUESDAY)...FIRE WEATHER PROCEDURE IS
SHOWING ELEVATED CONDITIONS/ISOLATED CRITICAL OVER MUCH OF THE AREA
ON TUESDAY. FUEL DRYNESS FORECAST MAP IS SHOWING MOST AREAS IN
NORMAL MOISTURE..WITH ONLY A PART OF THE NORTHERN COASTAL BEND (LIVE
OAK AND PORTIONS OF BEE AND MCMULLEN COUNTIES) IN DRY FUELS. SINCE
THESE COUNTIES ARE FORECAST TO BE IN ELEVATED CONDITIONS ON
TUESDAY...NO NEED FOR FIRE WEATHER WATCH OR RED FLAG WARNING. DAY
SHIFT OR NEXT MID SHIFT CAN RE-EVALUATE...ESPECIALLY IF FUEL DRYNESS
MAP CHANGES THE NEXT DAY.
&&
.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...PERIOD BEGINS WITH
COOLER TEMPERATURES AND DRY CONDITION IN WAKE OF TUESDAY/S/S FROPA.
BROAD LONGWAVE TROUGH CENTERED OVER THE FAR NORTH CENTRAL STATES
WILL KEEP FAIRLY ZONAL FLOW OVER SOUTH TEXAS THROUGH THURSDAY.
TROUGH WILL FINALLY SWING OVER THE REGION THURSDAY NIGHT INTO
FRIDAY. ECMWF CONTINUES TO BE THE WETTER SOLUTION WITH THIS PASSING
WHILE THE GFS/NAM STAY MOSTLY DRY OVERLAND. WHILE THERE IS THE UPPER
LEVEL SUPPORT FOR PERHAPS SOME SPRINKLES AND RAIN TO DEVELOP THERE IS
AN OVERALL LACK OF SUFFICIENT MOISTURE OVER MOST OF THE REGION
EXCEPT IN THE OVER THE OFFSHORE WATERS THURSDAY NIGHT INTO FRIDAY
MORNING. KEPT THE 20 POPS MENTION OVER THE OFFSHORE WATERS FOR
NOW...BUT EVEN THIS MAY BE GOING TOO HIGH. OTHERWISE EXPECT A
CONTINUED DRY FORECAST. TEMPERATURES WILL BE NICELY COOLER (BELOW
AVERAGE) THROUGH THE END OF THE WEEK BEFORE RETURNING TO NORMAL ON
BY THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 99 66 93 61 80 / 10 0 10 10 10
VICTORIA 93 63 88 55 81 / 10 0 10 10 10
LAREDO 104 69 98 62 86 / 0 0 10 10 10
ALICE 102 64 96 57 83 / 10 0 10 10 10
ROCKPORT 92 67 89 62 79 / 10 0 10 10 10
COTULLA 98 63 92 54 83 / 0 0 0 10 10
KINGSVILLE 102 65 97 60 81 / 10 0 10 10 10
NAVY CORPUS 90 67 87 65 79 / 10 0 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 11 AM CDT THIS MORNING FOR THE
FOLLOWING ZONES: 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.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT EARLY THIS MORNING FOR THE
FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT
ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT
O`CONNOR.
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.
&&
$$
GW/86...SHORT TERM
LK/84...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1226 AM CDT MON APR 28 2014
.DISCUSSION...SEE 06Z AVIATION DISCUSSION AND MARINE
DISCUSSION...AS EXTENDED THE SCA FOR ANOTHER FEW HOURS.
&&
.AVIATION...IFR CIGS WILL CONTINUE OR DEVELOP AT KCRP AND
KVCT...AND MAY EVEN GET INTO KALI BEFORE SUNRISE. VSBYS SHOULD BE
MVFR FOR THE MOST PART...BUT COULD SEE SOME TEMPO IFR AT KVCT AND
KALI. SURFACE TROUGH APPROACHES THIS MORNING...BRINGING NORTHWEST
WINDS AND SHOULD RAPIDLY LIFT IFR CONDITIONS BY 15Z. CONDITIONS
SHOULD REMAIN VFR FOR THE REST OF THE PERIOD...EXCEPT MAYBE SOME
LIGHT FOG AT KVCT ONCE THE WINDS DIE DOWN. GENERALLY N-NW WINDS BY
15Z DIMINISHING IN THE AFTERNOON...THEN LIGHT SOUTHERLY AFTER
SUNSET AS SEA-BREEZE DIMINISHES.
&&
.MARINE...WINDS NEAR THE COAST ARE STILL GOING PRETTY
STRONG...WITH KNGP GUSTING TO OVER 30 KNOTS. BASED ON HRRR AND
LOWER RESOLUTION MODEL DATA...HAVE EXTENDED THE SCA FOR THE BAYS
AND FOR THE NEARSHORE WATERS ANOTHER 1-2 HOURS. WILL KEEP MENTION
OF CONVECTION IN FOR NOW...BUT MAY PULL IT OUT IN THE MORNING
PACKAGE IF DRIER MODEL TRENDS CONTINUE. UPDATED MWW AND CWF OUT.
&&
.PREV DISCUSSION... /ISSUED 710 PM CDT SUN APR 27 2014/
DISCUSSION...UPDATED FOR 00Z AVIATION.
AVIATION...DRYLINE HAS RETREATED THIS EVENING WITH E TO ESE WINDS
RETURNING TO ALI/CRP. VFR CONDITIONS WILL PERSIST THROUGH AT LEAST
06Z...BUT MVFR/IFR CONDITIONS MAY DEVELOP AT ALI/VCT LATE TONIGHT
WITH LOW CLOUDS AND FOG/BR...AND MVFR CONDITIONS AT CRP DUE TO BR.
CONDITIONS WILL IMPROVE BY 14Z ON MONDAY WITH VFR CONDITIONS
THROUGH THE REMAINDER OF THE DAY.
PREV DISCUSSION... /ISSUED 413 PM CDT SUN APR 27 2014/
SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...CONCUR WITH THE
GFS/NAM THAT AN UPPER LOW WILL MEANDER OVER THE PLAINS DRG THE
PERIOD WITH EMBEDDED DISTURBANCES/SHORTWAVES MOVG WWD ACRS SOUTH
CENTRAL TX AND AN UPPER JET ACRS NRN/CNTRL TX. THUS MUCH OF THE
DYNAMICS WILL REMAIN NORTH OF THE CWA/MSA. ANTICIPATE THE
DEVELOPMENT OF RADIATIONAL FOG EARLY MONDAY OVER THE ERN CWA PER
NAM SOUNDINGS/SREF OUTPUT. SUFFICIENT MSTR PER NAM PWAT AND
LIMITED DYNAMICS MAY RESULT IN ISOLD CONVECTION NEAR THE COAST
EARLY MONDAY BEFORE SIGNIFICANT DRYING OCCURS. THE DRY LINE IS
EXPECTED TO MOVE ACRS THE CWA AGAIN RESULTING IN HOT CONDITIONS
MONDAY AFTN AT LEAST OVER THE CNTRL/WRN SECTIONS.
MARINE...EXPECT SCA CONDITIONS TO PERSIST OVER THE COASTAL WATERS
OVERNIGHT PER NAM DETERMINISTIC/UPPER JET DYNAMICS TO THE NW.
ANTICIPATE THAT SCA CONDITIONS OVER THE SRN BAYS WL CONTINUE AT
LEAST UNTIL 03Z MONDAY YET CONFIDENCE NOT TOO GREAT. PATCHY SEA
FOG EXPECTED OVER THE BAYS/COASTAL WATERS TONIGHT WHEN CONSIDERING
SFC DEW POINTS/SST VALUES/WIND. LIKELIHOOD FOR SEA FOG DECREASES
AFTER 12Z MONDAY OWING TO FCST WIND PATTERN. PATCHY SEA FOG
EXPECTED TO DEVELOP AGAIN OVER THE COASTAL WATERS DRG THE 00-09Z
TUESDAY PERIOD BEFORE WIND BECOMES UNFAVORABLE AGAIN.
LONG TERM (TUESDAY THROUGH SUNDAY)...FRONTAL BOUNDARY WILL MOVE
THROUGH THE CWA SOMETIME BETWEEN 12Z AND 18Z ON TUESDAY. GFS NAM AND
SREF OUTPUT ALL GENERALLY AGREEING ON AN EARLIER FRONTAL PASSAGE
AROUND 12Z...WITH ECM FAVORING A PASSAGE CLOSER TO 18Z. WITH THE
COOLER AIRMASS MOVING IN BEHIND THE FRONT...THIS MAKES FOR A RATHER
UNCERTAIN HIGH TEMPERATURE FORECAST SINCE ITS HARD TO GAUGE HOW MUCH
TEMPERATURES ARE GOING TO WARM UP IN ADVANCE OF THE FRONT.
REGARDLESS...THERE IS NOT MUCH OF A CHANCE FOR PRECIPITATION DUE TO
INSUFFICIENT MOISTURE. DECIDED TO GO COOLER RATHER THAN WARMER DUE
TO MORE NWP MODELS CALLING FOR THE EARLIER PASSAGE. HIGH PRESSURE
SURFACE RIDGE SETTLES IN BEHIND THE FRONT AND DOESNT REALLY GO
ANYWHERE UNTIL SATURDAY. ADDITIONALLY...PERSISTENT MID LEVEL
GENERALLY WESTERLY FLOW ALOFT WILL PREVAIL DURING THIS TIME ON THE
SOUTH SIDE OF A LARGE AND SLOW MOVING CLOSED UPPER LEVEL LOW
CENTERED OVER THE MIDWEST. WINDS AT THE SURFACE WILL REMAIN NE ON
WED AND THEN BECOME MORE EASTERLY ON THURSDAY AND FRIDAY. MAY SEE
SOME SCEC/SCA CONDITIONS OFFSHORE WEDNESDAY AND THURSDAY AS THE
PRESSURE GRADIENT TIGHTENS IN RESPONSE TO A SURFACE TROUGH LOCATED
OVER THE YUCATAN. THURSDAY AND FRIDAY WILL SEE MORE MID LEVEL
MOISTURE AND THUS MORE CLOUD COVER...KEEPING TEMPERATURES COOLER. A
STRONG SHORTWAVE DISTURBANCE IS FORECAST TO MOVE OVERHEAD
FRIDAY...BUT THE BEST MOISTURE AVAILABILITY SHOULD BE TOO FAR SOUTH
FOR ANY DECENT POPS. HAVE STILL INCLUDED 20 POPS OVER THE OFFSHORE
WATERS AS MOISTURE CONTENT LOOKS AS IF IT WILL BE SLIGHTLY HIGHER
THERE. OVER THE WEEKEND...SURFACE HIGH PRESSURE FINALLY SHIFTS
OFFSHORE...WITH MODERATE TO STRONG SOUTHEASTERLY FLOW RETURNING AS A
RESULT.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 66 85 60 84 60 / 10 10 10 10 10
VICTORIA 64 82 54 81 53 / 10 10 10 10 10
LAREDO 68 89 60 86 60 / 10 10 10 10 10
ALICE 64 86 57 84 56 / 10 10 10 10 10
ROCKPORT 68 84 63 83 61 / 10 10 10 10 10
COTULLA 62 86 55 84 55 / 0 0 10 10 10
KINGSVILLE 65 88 58 83 58 / 10 10 10 10 10
NAVY CORPUS 69 83 64 80 64 / 10 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR THE
FOLLOWING ZONES: 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.
SMALL CRAFT ADVISORY UNTIL 2 AM CDT EARLY THIS MORNING FOR THE
FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT
ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT
O`CONNOR.
SMALL CRAFT ADVISORY UNTIL 5 AM CDT EARLY 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.
&&
$$
GW/86...AVIATION
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1148 PM CDT SUN APR 27 2014
.UPDATE...
FORECAST IS ON TRACK. POPS OF 20-30 PERCENT OVER THE EAST SHOULD
COVER ISOLATED TO SCATTERED NATURE OF SEVERE CONVECTION...BUT DID
EXTEND DURATION FROM 6Z TO 9Z. UPDATED TEXT PRODUCTS TO INCLUDE
MENTION OF NEW TORNADO WATCH. WHILE LARGE HAIL IS THE MAIN
THREAT...ANY SUPERCELL STORMS WILL HAVE THE ABILITY TO OVERCOME
LOW LEVEL INHIBITION AND ACCESS NEAR SURFACE AIR PARCELS WHICH
WILL INCREASE THE RISK FOR ROTATION AND TORNADOGENESIS. THIS IS
MOST LIKELY PARTICULARLY ACROSS THE SOUTHEAST ZONES WHERE CIN IS
LOWEST. TR.92
&&
.AVIATION...
ALL CURRENT CONVECTION FIRING EAST OF TAF SITES AND WILL CONTINUE
TO MOVE EAST AWAY FROM THE TRACON. OTHERWISE...VFR FORECAST WITH
NO CONCERNS. MID-HIGH CLOUDS WILL BE IN PLACE OVERNIGHT...BUT
SHOULD SCATTER OUT TOMORROW...ONLY TO ARRIVE AGAIN MONDAY EVENING.
LIGHT SOUTHWEST WINDS TONIGHT WILL BECOME NORTHWEST BEHIND A WEAK
FRONT BY SUNRISE. WITH DEEP MIXING...WINDS SHOULD TURN TO A MORE
WESTERLY DIRECTION AT SPEEDS NEAR 15KT TOMORROW AFTERNOON. SPEEDS
LIKELY NOT HIGH ENOUGH TO CAUSE MAJOR ISSUES WITH N-S RUNWAYS.
TR.92
&&
.UPDATE...
LATEST MESO-ANALYSIS INDICATED A STATIONARY DRY LINE FROM BONHAM
TO MESQUITE TO NEAR CAMERON. MEANWHILE A PACIFIC COLD FRONT WAS
JUST A FEW MILES TO ITS WEST...ALONG A LINE SHERMAN TO FORT WORTH
TO LAMPASAS. WINDS BEHIND THE FRONT WERE STRONGER AND FROM THE
WEST BUT RAPID BOUNDARY LAYER DECOUPLING SHOULD OCCUR IN THE NEXT
HOUR WITH WINDS DROPPING BELOW WIND ADVISORY CRITERIA. EXPIRED
WIND ADVISORY ON TIME AT 7 PM.
MORE CONCERNING WITH THE FORECAST IS THE CONVECTIVE POTENTIAL THIS
EVENING. WITH THE SUN SETTING...THE THREAT FOR INITIATION OF
SURFACE BASED CONVECTION ALONG THE DRY LINE WILL WANE DUE TO
INCREASING CIN AND THE SEVERE WATCH WILL LIKELY EXPIRE AT 8PM.
THE DRY LINE WILL MOVE BACK TO THE WEST AFTER SUNSET AS IS OFTEN
THE CASE...LIKELY MEETING OR PERHAPS ALSO PUSHING THE PACIFIC
FRONT BACKWARD. THE FRONT IS AWAITING A PUSH FROM A STRONG
SHORTWAVE THAT WILL ARRIVE LATER THIS EVENING...WITH STRONG UPWARD
FORCING BEGINNING TO SPREAD ACROSS THE REGION AFTER 10 PM. WHILE
SURFACE BASED CONVECTION FIRING ALONG A WESTWARD RETREATING DRY
LINE DURING THE EVENING IS RARE DUE TO INCREASED CIN...IT DOES
HAPPEN OCCASIONALLY.
INSTEAD WHAT IS LIKELY TO HAPPEN IS THAT UPWARD FORCING OCCURRING
IN THE PRESENCE OF NEARLY DRY ADIABATIC LAPSE RATES UP TO 14000
FEET WILL SQUEEZE OUT WHATEVER MOISTURE IT CAN FIND FOR ELEVATED
HIGH BASED CONVECTION. MODEL SOUNDINGS FROM THE RAP ARE MOST
AGGRESSIVE WITH THIS SCENARIO...AND SUGGEST ISOLATED TO SCATTERED
ELEVATED THUNDERSTORMS DEVELOPING ALONG THE I-35 CORRIDOR AND
GATHERING STRENGTH AS THEY HEAD INTO THE DEEPER MOISTURE ACROSS
THE EASTERN ZONES. OBVIOUSLY ANY STORMS IN THIS ENVIRONMENT WILL
HAVE A LARGE HAIL THREAT. WHILE THIS IS A POSSIBLE SCENARIO...IT
IS UNCERTAIN RIGHT NOW HOW LIKELY IT IS. THEREFORE WE WILL KEEP
POPS AT 20-30 PERCENT THROUGH 1 AM OVER AREAS JUST EAST OF I-35
AND CONTINUE TO WATCH TRENDS IN SATELLITE AND RADAR DATA FOR
ADDITIONAL DEVELOPMENT LATER THIS EVENING.
TR.92
&&
.PREV DISCUSSION... /ISSUED 319 PM CDT SUN APR 27 2014/
DRYLINE/SURFACE TROUGH CONTINUES MOVING EAST AND CURRENTLY
EXTENDED FROM NEAR BONHAM...TO DALLAS...TEMPLE AND WAS MOVING
SLOWLY EAST. ONE ISOLATED STRONG STORM WAS UP NEAR BONHAM WITH
ANOTHER POTENTIALLY DEVELOPING CELL OVER EASTERN COLLIN CO...
OTHERWISE IT REMAINED QUIET. DESPITE SURFACE DEW POINTS BETWEEN
65-70 DEGREES...WARM TEMPERATURES...INSTABILITY ABOVE 2000 J/K AND
GOOD SHEAR...LOW LEVEL CONVERGENCE ACROSS OUR CENTRAL TEXAS
COUNTIES WAS NOT AS GOOD DUE TO SLIGHTLY VEERED FLOW AHEAD OF THE
DRYLINE. THIS MAY CHANGE AS A 300MB SPEED MAX CONTINUES ROTATING
NORTHEAST THROUGH 00Z AND HELPS TRIGGER ISOLATED STORMS...POSSIBLY
MORE SCATTERED IN THE FAR E/NE FROM CORSICANA/ATHENS NORTHWARD.
QUICK CHAT WITH SPC WAS THAT CURRENT SEVERE THUNDERSTORM WATCH 94
WOULD BE ALLOWED TO EXPIRE AT 3 PM AND REPLACED BY SEVERE
THUNDERSTORM WATCH 99 FOR OUR FAR EAST CENTRAL AND NORTHEAST
COUNTIES THROUGH 8 PM. SEVERE STORMS ARE ALREADY DEVELOPING
RAPIDLY AND BECOMING SEVERE BETWEEN BONHAM AND PARIS WITH OTHER
SIGNS OF DEVELOPMENT SOUTHWEST TOWARD ROCKWALL AND TERRELL. LOOK
FOR A 10-30 PERCENT COVERAGE OF POSSIBLE STRONG TO SEVERE STORMS
ACROSS THE EASTERN THIRD OF NORTH TEXAS INTO EARLY EVENING WITH
HAIL AND DAMAGING WINDS THE MAIN THREATS DUE TO THE AFOREMENTIONED
SLIGHTLY VEERED FLOW AHEAD OF THE DRYLINE.
BEHIND THE DRYLINE...GUSTY WEST-SOUTHWEST WINDS 20 TO 30 MPH WITH
GUST 35 TO 40 MPH ARE EXPECTED AND MAY RESULT IN SOME BLOWING DUST
FROM THE DFW METROPLEX NORTH AND WEST THROUGH MID EVENING. BEYOND MID
EVENING...WE EXPECT THE DRYLINE TO REACH OUR EASTERN EDGE AND RISK
FOR SEVERE STORMS MOVING INTO EAST TEXAS...THE ARKLATEX AND MID MS
VALLEY. DRIER AIR TONIGHT COMBINED WITH DIMINISHING WEST WINDS
SHOULD ALLOW FOR A COOL AND PLEASANT NIGHT...BEFORE ANOTHER WINDY...
DRY AND VERY WARM DAY ENSUES MONDAY WITH FIRE WEATHER CONCERNS AND
POSSIBLY ANOTHER WIND ADVISORY NEEDING TO BE ISSUED. WEST-
SOUTHWEST WINDS 15-25 MPH AND GUSTY ARE EXPECTED OR POSSIBLY
SLIGHTLY HIGHER BY MONDAY AFTERNOON.
THE FIRST OF SEVERAL COLD FRONTAL SURGES IS EXPECTED TO ARRIVE
MONDAY NIGHT INTO TUESDAY MORNING. MEANWHILE...ANOTHER STRONG
CYCLONICALLY CURVED SHORTWAVE WILL ROTATE ACROSS THE RED RIVER
WITH MOST MOISTURE ANCHORED ABOVE 700MB. ONLY MENTIONED ISOLATED
HIGH-BASED OR ELEVATED SHOWERS FOR THIS PERIOD...THOUGH EVENTUALLY
THUNDER MAY NEED TO BE INTRODUCED IF LAPSE RATES REMAIN HIGH. THE
LOW LEVELS WILL REMAIN VERY DRY...SO LITTLE MEASURABLE RAINFALL
WOULD OCCUR WITH THE FRONTAL PASSAGE. MAY WELL BE JUST SOME VIRGA
WOULD COULD POSSIBLY TRANSLATE SOME GUSTIER NORTHWEST WINDS DOWN
THE SURFACE BY TUESDAY MORNING.
AFTERWARD...A DRY AND SEASONABLY COOL PERIOD IS EXPECTED WITH THE
DRY CONTINENTAL AIRMASS BEING SUPPORTED BY STALLING AND OCCLUDING
UPPER LOW PIN-BALLING OVER THE MID MISSISSIPPI VALLEY AND MIDWEST.
AS NOTED IN PREVIOUS DISCUSSIONS...THE REASON FOR THE UPPER LEVEL
LOW REMAINING STATIONARY IS A BLOCKING UPPER HIGH OVER EASTERN
CANADA. THE AIRMASS WILL BE UNUSUALLY DRY FOR HEADING INTO EARLY
MAY AND ALLOW FOR A LARGE DIURNAL RANGE ON LOWS AND HIGHS WITH
45-50 FOR LOWS AND HIGHS 70-75...EXCEPT SLIGHTLY WARMER OVER
CENTRAL TEXAS. FLOW ALOFT OVER NORTH TEXAS DAMPENS BY NEXT WEEKEND
AS THE EASTERN CANADIAN RIDGE FINALLY WEAKENS AND ALLOW THE
OCCLUDED UPPER LOW TO BE OPENED UP AND CARRIED QUICKLY EAST.
SOUTHERLY LOW LEVEL FLOW THEN RETURNS AND HIGHS REBOUND BACK INTO
THE 80S.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 58 84 52 75 50 / 5 5 10 10 5
WACO, TX 56 87 51 80 47 / 10 5 5 5 5
PARIS, TX 57 79 51 72 46 / 30 5 10 10 5
DENTON, TX 52 84 48 74 45 / 5 5 10 5 5
MCKINNEY, TX 53 84 49 73 46 / 20 5 10 10 5
DALLAS, TX 62 86 54 75 51 / 10 5 10 10 5
TERRELL, TX 57 83 52 75 47 / 30 5 10 10 5
CORSICANA, TX 58 86 55 78 48 / 30 5 5 10 5
TEMPLE, TX 59 88 55 79 48 / 20 5 5 5 5
MINERAL WELLS, TX 52 87 49 76 47 / 5 5 10 10 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1142 PM CDT SUN APR 27 2014
.DISCUSSION...
06Z TAF DISCUSSION IN AVIATION SECTION.
&&
.AVIATION...
DRYLINE/PAC FRONT LOOKS TO BE MAKING SOME PROGRESS THROUGH C TX
TONIGHT. HRRR AND EVEN NAM HINTING AT POSSIBILITY OF CONVECTION
DURING THE MORNING HOURS AS BOUNDARY MOVES SOUTH. BASED OFF
EVENING SOUNDING DATA THINK CAP MAY BE TOO STRONG FOR CONVECTION
BUT WORTH NOTING. WILL LEAVE OUT MENTION OF TSRA IN TAFS FOR NOW.
CONVECTION ALONG BOUNDARY MAY SUGGEST THESE MODELS ARE ON THE
RIGHT TRACK. OTHERWISE EXPECT IFR/MVFR CIGS UNTIL BOUNDARY PUSHES
SOUTH WITH DRIER AIR BEHIND IT. HAVE CLEAR SKIES FOR TOMORROW
AFTERNOON. BOUNDARY MAY PUSH BACK NORTH WITH MOISTURE SOUTH OF THE
FRONT. COULD GET LOW CLOUD DECKS AGAIN.
39
&&
.PREV DISCUSSION... /ISSUED 1120 PM CDT SUN APR 27 2014/
UPDATE...
UPDATED THE FORECAST FOR TORNADO WATCH 105 ISSUED UNTIL 5 AM THAT
INCLUDES HOUSTON AND TRINITY COUNTIES. ADDED ISOLATED SEVERE
THUNDERSTORMS FOR BOTH COUNTIES.
40
PREV DISCUSSION... /ISSUED 940 PM CDT SUN APR 27 2014/
DISCUSSION...
ISOLATED STRONG TO SEVERE THUNDERSTORMS THAT OCCURRED ALONG
HIGHWAY 290 IN WESTERN AND CENTRAL WASHINGTON COUNTY HAVE
WEAKENED. AS THE DRY LINE MOVES INTO SE TX...ISOLATED SHOWERS OR
THUNDERSTORMS MAY DEVELOP LATER TONIGHT. AFTER LOOKING AT THE
SHORT RANGE MODELS...IT APPEARS THAT THE BEST LOCATIONS ARE
GENERALLY ALONG AND NORTH OF A LINE FROM BRENHAM TO CLEVELAND.
THE 00Z RUN OF THE NAM12 WEAKENS THE LOW-LEVEL JET OVERHEAD OF THE
AREA LATER THIS EVENING. WITH THIS IN MIND...TOOK OUT THE MENTION
OF DRIZZLE FOR THE REMAINDER OF THE NIGHT.
40
PREV DISCUSSION... /ISSUED 752 PM CDT SUN APR 27 2014/
UPDATE...
UPDATE FOR ISOLATED THUNDERSTORMS MOVING TOWARD BURLESON AND
WASHINGTON COUNTIES FROM THE WEST.
40
DISCUSSION...
DRY LINE/COLD FRONT APPROACHING FROM THE WEST. ISOLATED
THUNDERSTORMS HAVE DEVELOPED AHEAD OF THE DRY LINE IN BASTROP AND
LEE COUNTIES AND WERE MOVING INTO BURLESON AND WASHINGTON
COUNTIES. LARGE HAIL HAS BEEN REPORTED...BUT THE STORM MOVING
THROUGH BURLESON COUNTY WEAKENED BEFORE MOVING INTO THE COUNTY.
THE 00Z CRP SOUNDING HAD A SURFACE BASED CAPE OF ALMOST 4700...
ALTHOUGH THERE WAS A DECENT CAP IN PLACE. ISOLATED STRONG TO
SEVERE STORMS ARE POSSIBLE THROUGH MID EVENING AS THE STORMS THAT
DO DEVELOP MOVE OFF THE DRYLINE...ESPECIALLY ALONG AND NORTH OF A
LINE FROM BRENHAM TO HUNTSVILLE. DO EXPECT THE STORMS TO BEGIN
LOSING INTENSITY DURING THE LATE EVENING DUE TO THE LOSS OF
DAYTIME HEATING.
40
PREV DISCUSSION... /ISSUED 641 PM CDT SUN APR 27 2014/
DISCUSSION...
00Z TAF DISCUSSION IN AVIATION SECTION.
AVIATION...
SFC ANALYSIS HAS DRYLINE ALONG THE I-35 CORRIDOR WITH A FEW ISO
STORMS WEST OF KAUS. CAP EAST OF THESE STORMS PROBABLY STRONG
ENOUGH THAT THE STORMS SHOULD WEAKEN BEFORE REACHING KCLL SO WILL
CONTINUE TO MONITOR. LEFT TAF VOID OF CONVECTION AS PROBABILITIES
SMALL AT THIS POINT.
MAIN CONCERN WILL BE LOW MVFR CIGS AHEAD OF WEAK PACIFIC FRONT.
DRIER AIR SHOULD MIX INTO THE AREA BY THE MORNING HOURS AND HELP
SCT OUT CIGS 12-15Z WITH MAINLY CLEAR SKIES AFTER THAT. WINDS
SHOULD TURN TO THE WSW/WNW DIRECTIONS AROUND 10KTS. BOUNDARY
SHOULD WORK BACK NORTH MONDAY NIGHT WITH STRONGER PACIFIC FRONT ON
TUESDAY.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 65 91 62 82 51 / 20 10 10 10 10
HOUSTON (IAH) 72 91 68 86 55 / 20 20 10 10 10
GALVESTON (GLS) 73 82 72 82 62 / 20 10 10 20 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 7 AM CDT MONDAY FOR
THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING
ZONES: 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...40
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
952 PM EDT TUE APR 29 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT SLOWLY NORTH OF US BY EARLY WEDNESDAY
AFTERNOON. A LARGE AND COMPLEX STORM SYSTEM LOCATED OVER THE
CENTRAL UNITED STATES WILL MOVE SLOWLY EAST TO THE COAST BY
THURSDAY NIGHT. THIS SYSTEM WILL PROVIDE SEVERAL ROUNDS OF SHOWERS
AND THUNDERSTORMS...SOME WITH VERY HEAVY RAIN AND A SLIGHT RISK OF
SEVERE WEATHER.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 935 PM EDT TUESDAY...
RADAR CONTINUE STAYING QUIET THIS EVENING OVER OUR CWA. GETTING A
FEW SHOWERS ALONG THE BLUE RIDGE NORTH OF
BLACKSBURG/FLOYD/ROANOKE. DENSE FOG ALSO CREATING TRAVEL ISSUES
ALONG THE HIGHER ELEVATIONS AS WEDGE KEEPS LOW CLOUDS LOCKED IN
PLACE.
00Z RNK SOUNDING SHOWING THE DEPTH OF THE WEDGE TO BE 2000-2200
FEET. SAME GOES FOR THE GSO SOUNDING.
LOOP OF SFC ANALYSIS ACTUALLY SHOWING WEDGE NOT BUDGING...WITH
HIGH PRESSURE NOSING IN MORE OVER THE NEW ENGLAND COAST.
LATEST MODELS SEEM OVERDONE THIS EVENING ON RAINFALL FOR US SO
KEPT POPS LOW. HOWEVER...THE LOW LEVEL FLOW APPEARS TO BE TURNING
MORE SE OVERNIGHT SO KEEPING HIGHER POPS AROUND LATE...ESPECIALLY
OVER THE PIEDMONT/FOOTHILLS. UNTIL THEN SHOULD BE MAINLY LIGHT
RAIN/DRIZZLE/FOG...WITH SHOWERS BECOMING HEAVIER TOWARD DAWN.
RAN TEMPS COOLER EARLY ON WITH SLOW MODERATION TOWARD DAWN WHEN
HEAVIER RAINS MOVE IN BRINGING SOME WARMER AIR ALOFT DOWN.
CONFIDENCE IS LOW ON THE MODELS BREAKING THE WEDGE BY DAWN...AND
LATEST RAP MODEL SHOWING MORE OF IT ERODING BY MIDDAY
WEDNESDAY...WHICH SEEMS PLAUSIBLE.
NO CHANGES TO ONGOING FLASH FLOOD WATCHES OR FORECAST RAINFALL
AMOUNTS. DENSE FOG COVERED BY SPS. SEVERE THREAT OVERNIGHT IS LOW.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 330 PM EDT TUESDAY...
THE HIGH PRESSURE WEDGE BANKED AGAINST THE EASTERN FACE OF THE
APPALACHIANS WILL BE IN THE PROCESS OF ERODING OUT OF THE REGION BY
SUNRISE WEDNESDAY...AS A WARM FRONT LIFTS ACROSS OUR AREA...ALLOWING
WINDS TO SHIFT SOUTHERLY.
THE MAIN CONCERN TO START THE DAY WILL BE AREAS OF HEAVY RAIN
DEVELOPING ALONG AND EAST OF THE BLUE RIDGE AS WAVES OF ENERGY RIDE
IN FROM THE SOUTHWEST. RAINFALL FROM TUESDAY...EXCEEDING 2 INCHES IN
SOME AREAS...WENT A LONG WAY TO HELP SATURATE THE SOIL. EXPECT THAT
NEW THUNDERSTORMS DEVELOPING TUESDAY NIGHT WILL ALSO BE EFFICIENT
RAINFALL PRODUCERS...AND LOCALIZED FLASH FLOODING MAY RESULT WHERE
ANY OF THE STRONGER THUNDERSTORM CELLS BEGIN TO TRAIN ACROSS THE
SAME LOCATIONS. SOUTHEASTERLY UPSLOPE FLOW WILL LEAD TO LOCALLY
HIGHER RAINFALL AMOUNTS ALONG THE BLUE RIDGE AND OTHER PROMINENT
EAST FACING SLOPES. THE WIDESPREAD RAINFALL WILL ALSO BRING SOME
AREA RIVERS ABOVE FLOOD STAGE DURING THE SECOND HALF OF THE
WORKWEEK.
IN ADDITION TO HEAVY RAINFALL...ALSO SEE THE POTENTIAL FOR STRONG
THUNDERSTORMS DEVELOPING BY LATE MORNING ACROSS THE ENTIRE FORECAST
REGION. STRONG LOW LEVEL SHEAR WILL COMBINE WITH DAYTIME HEATING TO
SUPPORT A FEW STRONG THUNDERSTORMS AREAWIDE DURING LATE MORNING...
WITH THE GREATEST INSTABILITY SHIFTING TO THE PIEDMONT DURING THE
AFTERNOON AND EVENING AS STRONGER WINDS ALOFT MOVE OVER THE AREA.
BELIEVE THE GREATEST THREAT OF SEVERE WEATHER WILL BE IN THE FORM OF
STRONG WINDS...ALTHOUGH HAIL AND ISOLATED TORNADOES WILL ALSO BE
POSSIBLE. THE THREAT OF STRONG STORMS WILL GRADUALLY SHIFT EAST
THROUGH THE EVENING...AND SHOULD EXIT OUR AREA BY AROUND MIDNIGHT
THURSDAY MORNING.
EXPECT ONLY RESIDUAL SHOWER ACTIVITY ON THURSDAY AND FRIDAY...MAINLY
ACROSS THE MOUNTAINS...AS UPPER LEVEL TROUGHING REMAINS SITUATED
ACROSS THE FORECAST REGION. SOUTHWESTERLY FLOW ON THURSDAY WILL
ALLOW AFTERNOON HIGHS TO RANGE FROM THE MID 60S ACROSS THE MOUNTAINS
TO THE MID 70S ACROSS THE SOUTHSIDE. WEST TO NORTHWESTERLY FLOW ON
FRIDAY WILL BRING AFTERNOON HIGHS COOLER ABOUT 5 TO 7 DEGREES.
THURSDAY AND FRIDAY NIGHT LOWS WILL GENERALLY BE IN THE 40S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 100PM EDT TUESDAY...
MODELS IN GENERALLY GOOD AGREEMENT THROUGH THE EXTENDED PERIOD AS THE
ERN TROF SLIDES EAST AND ALLOWS RIDGING WITH NW FLOW TO BECOME
ESTABLISHED OVER OUR AREA. PREVIOUS MODEL RUNS INDICATING A SIGNIFICANT
COLD PUNCH FOR THE WEEKEND HAVE MELLOWED AND WILL TREND THE CURRENT
FORECAST GRIDS WARMER TOWARD THE HPC GUIDANCE.
BEST ENERGY WITH UPPER SHORT WAVE ROTATING AROUND THE BASE OF THE ERN
UPPER TROF SATURDAY IS SOUTH OF THE FA AND MOISTURE IS MORE LIMITED.
THIS WILL HELP SUPPRESS SHOWER ACTIVITY ON SATURDAY AS A WEAK SFC
BOUNDARY PUSHES THROUGH SO WILL BE MUCH LESS AGGRESSIVE WITH POPS.
THERE IS NO BIG PUSH TO THIS BOUNDARY AND IT WILL REMAIN IN THE
NEIGHBORHOOD FOR THE REMAINDER OF THE FORECAST PERIOD. THERE ARE
INDICATIONS OF IMPULSES RIDING ALONG THE FRONT BUT SUBTLE DIFFERENCES
IN PLACEMENT OF FEATURES WILL MAKE A BIG DIFFERENCE IN SENSIBLE
WEATHER. WILL OPT TO CONFINE POPS TO THE TUESDAY PERIOD AS THE BOUNDARY
GETS ENOUGH PUSH TO MOVE THROUGH AS A WARM FRONT.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
AS OF 745 PM EDT TUESDAY...
EXTREMELY POOR FLYING CONDITIONS EXPECTED THIS EVENING AND
OVERNIGHT WITH WEDGE IN PLACE. LOW CONFIDENCE FORECAST IN
INTENSITY/TIMING OF SHOWERS/STORMS AND ITS EFFECTS ON VSBYS/CIGS
BUT HIGH CONFIDENCE THAT ALL SITES WILL STAY SUB VFR THROUGH MOST
OF THIS PERIOD. WINDOW OF HEAVIER SHOWERS AND STORMS ARRIVES AFTER
09Z ACROSS THE ROA/BCB/DAN AREA AND SHORTLY BY 12Z IN LYH/BLF AND
LWB. STILL LOOKS LIKE HEAVIER WILL BE ALONG AND EAST OF THE BLUE
RIDGE. UNTIL THE HEAVIER SHOWERS ARRIVE EXPECT LOWER CIGS/VSBYS AS
LOW AS LIFR.
DURING WEDNESDAY WILL SEE MOST OF THE DAY SHIFTING TOWARD SHOWERS
AND STORMS WITH WINDS SHIFTING TOWARD THE SOUTHEAST TO SOUTHWEST
AND WEDGE BREAKING. COLD FRONTAL BOUNDARY WILL NOT REACH BLF/LWB
AT LEAST UNTIL 00Z THU. THINGS SHOULD DRY OUT TOWARD LATE WED
AFTERNOON IN THE WEST.
AS FOR LOW LVL WIND SHEAR GIVEN SHOWERS IN THE AREA OVERALL WILL
LEAVE IT OUT...BUT EXPECT SOME STRONGER SOUTHERLY WINDS ACROSS THE
REGION ABOVE THE WEDGE LATE THIS EVENING INTO EARLY OVERNIGHT.
APPEARS ENOUGH DRYING ALOFT TO PERHAPS SEE IMPROVEMENT TO VFR
ACROSS THE EAST LATER THURSDAY INTO FRIDAY WITH MVFR LIKELY
LINGERING AT TIMES ACROSS THE SE WEST VA LOCATIONS INTO FRIDAY. A
WEAK LOW PRESSURE SYSTEM WILL CROSS THE TENNESSEE VALLEY ON
SATURDAY AND SUNDAY WITH A CHANCE OF PRECIPITATION AND MVFR
CONDITIONS IN THE MOUNTAINS.
&&
.HYDROLOGY...
AS OF 950 PM EDT TUESDAY...
NO CHANGES TO THE RIVER FORECASTS...STILL EXPECTING ENOUGH QPF TO
BRING PORTIONS OF THE LOWER ROANOKE AND DAN TO GO INTO MODERATE
FLOOD IN A COUPLE OF DAYS. HOWEVER...THIS RAINFALL WILL IS LIMITED
THIS EVENING AND WILL HAVE TO COME AS THE WARM FRONT LIFTS NORTH
WEDNESDAY MORNING FOLLOWED BY THE COLD FRONT WEDNESDAY AFTERNOON
AND EVENING. STILL MAINLY CONCERNED WITH FLASH FLOOD THREAT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR VAZ007-009>020-
022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR NCZ001>006-
018>020.
WV...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR WVZ042>045.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...AMS/WP
SHORT TERM...NF
LONG TERM...MBS
AVIATION...AMS/JH/WP
HYDROLOGY...AMS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
711 AM EDT MON APR 28 2014
.SYNOPSIS...
A WEAK STATIONARY FRONT WILL REMAIN JUST SOUTH AND WEST OF THE
REGION TODAY INTO TUESDAY. A LARGE AND COMPLEX STORM SYSTEM
LOCATED OVER THE CENTRAL UNITED STATES WILL SLOWLY MOVE EAST. THIS
SYSTEM WILL PROVIDE RAINFALL FOR MUCH OF THE UPCOMING WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 250 AM EDT MONDAY...
WEAK BACKDOOR TYPE COLD FRONT NOW HEADING INTO THE SW PORTIONS OF
THE CWA WITH A STIFF EASTERLY FLOW DEVELOPING ESPCLY EAST OF THE
BLUE RIDGE WHERE BEST COOL ADVECTION WILL TAKE SHAPE THIS MORNING.
INIT MID LEVEL WAVE EJECTING OUT INTO THE SHORTWAVE RIDGING ALOFT
LIKELY TO HELP MOISTEN THE COLUMN EARLY ON WITH MAINLY JUST SPOTTY
-RA OR SPRINKLES INTO MID MORNING PER LATEST RADAR TRENDS. MAIN
SHOT AT MORE WIDESPREAD RAINFALL LOOKS TO COME FROM LATE MORNING
INTO MID AFTERNOON AS ANOTHER WAVE SLIDES BY TO THE NW AND HELPS
UPWARD MOTION SWING ACROSS THE NORTH UNDER A CORE OF SLIGHTLY
HIGHER 85H WINDS. MOST GUIDANCE ON TRACK WITH THIS FEATURE WITH
THE LATEST HRRR EXPANDING THIS AXIS EAST TO ALONG THE BLUE RIDGE
AROUND MIDDAY BEFORE TAKING IT TO THE EAST DURING THE AFTERNOON
ALONG THE GRADIENT OF THE THETA-E AXIS ALOFT. THUS HAVE INCLUDED
SOME CHANCE POPS MAINLY WEST EARLY THIS MORNING...THEN A PERIOD OF
LIKELYS FROM WEST TO EAST THROUGH LATE AFTERNOON WHEN SEE BEST
OVERRUNNING. HOWEVER QPF DOESNT LOOK TOO IMPRESSIVE WITH THIS
FEATURE WITH A TENTH TO A QUARTER INCH POSSIBLE WITH ANY THUNDER
FAR WEST AWAY FROM THE DEVELOPING EASTERN WEDGE. HIGH TEMPS REMAIN
TRICKY AS COULD SEE AREAS ACROSS THE NE ONLY RISE A FEW DEGREES
WHILE JUMPING ABOVE 70 ALONG THE I-77 CORRIDOR. WENT CLOSER TO THE
COLDER MET MOS ALONG/EAST OF THE BLUE RIDGE AND A BLEND OUT WEST.
IMPULSE EXITS BY THIS EVENING LEAVING MOST OF THE REGION IN A
STRONG WEDGE WITH ABSENCE OF MUCH LIFT WITH A BAND OF DEEPER
CONVECTION APPROACHING THE MOUNTAINS FROM THE WEST LATE. HOWEVER
SOUNDINGS SHOW A RATHER DEEP EAST/SE LOW LEVEL FLOW UNDER VEERING
ALOFT WHICH WOULD SUPPORT AT LEAST SPOTTY -RA/DZ OUTSIDE THE FAR
WEST WITH ADDED UPSLOPE LIKELY ENHANCING COVERAGE EASTERN SLOPES
OF THE BLUE RIDGE. WEAKENING SHRA/TSRA HEADED IN FROM THE WEST
AROUND DAYBREAK COULD REACH THE WESTERN SLOPES SO KEPT IN SOME
THUNDER MENTION ON THE PERIMETER OF THE WEDGE FOR NOW OVERNIGHT.
OTRW CLOUDY AND DAMP WITH PERIODS OF -RA/DZ AND PERHAPS A FEW MORE
-SHRA SW AS DEEPER WARM ADVECTION SPREADS NORTH ALOFT LATE. KEPT
LOWS CLOSER TO THE COOLER MET MOS AGAIN IN EXPECTING A STRONGER
WEDGE IN THE WAKE OF EARLIER RAINFALL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM EDT MONDAY...
DEEP UPPER CLOSED LOW OVER IOWA AND THE UPPER RIDGE ALONG THE EAST
COAST WILL MOVE EAST DURING THE PERIOD. THE MAIN LOW MOVES EAST
ACROSS THE GREAT LAKES WHILE A WAVE OF LOW PRESSURE ALONG THE
FRONTAL BOUNDARY WILL TRACK TOWARD THE MISSISSIPPI RIVER BY TUESDAY
EVENING.
PLENTY OF MOISTURE IS TRANSPORTED INTO THE REGION FROM THE ATLANTIC
OCEAN AT LOWEST LEVELS AND FROM THE GULF OF MEXICO THROUGH A DEEP
LAYER FARTHER ALOFT. HIGH TEMPERATURES ON TUESDAY ARE TRICKY
DEPENDING SUNSHINE AND AMOUNT OF RAIN. PLAYED HIGHS TOWARDS THE
COOLER ADJMET WITH VALUES FROM THE UPPER 50S ACROSS THE NORTH TO THE
LOWER 70S ACROSS THE SOUTH. THE SWODY2 HAS A FEW SOUTHEAST COUNTIES
IN THE SLIGHT RISK FOR SEVERE THUNDERSTORMS. APPEARS THAT THEY ARE
ALLOWING THE WEDGE TO WEAKEN ON THE SOUTHERN END FOR A FEW HOURS.
WITH THE STRENGHT OF THE WEDGE...GENERALLY UNDERDONE ON THE
MODELS...QUESTIONS ON WHETHER THE WEDGE MIXES OUT FOR A FEW HOURS
TUESDAY AFTERNOON.
BEST Q-V FORCING AND UPPER DIFFLUENCE IN THE RIGHT REAR QUADRANT OF
THE UPPER JET WILL BE TUESDAY NIGHT AND WEDNESDAY. PRECIPITABLE
WATER VALUES RISE TO AS HIGH AS 1.6 INCHES ACROSS THE SOUTHERN AND
EASTERN COUNTY WARNING AREA TUESDAY...WHICH IS AROUND TWO STANDARD
DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR. KEPT THE HIGHEST QPF
IN THE TUESDAY NIGHT TO WEDNESDAY TIME FRAME...SIMILAR TO WPC
GUIDANCE. HPC HAS PLACED EXCESSIVE RAINFALL POTENTIAL FOR DAY 2-3
ALONG AND EAST OF THE BLUE RIDGE. HOWEVER WILL HOLD OFF ON A FLOOD
WATCH FOR NOW GIVEN INTERVALS OF HEAVY RAIN AND WHERE EXCESSIVE
MAY OCCUR BASED ON RAINFALL THROUGH MONDAY NIGHT. THUS WILL
MENTION FLOODING POTENTIAL IN THE HWO FOR TUESDAY INTO WEDNESDAY.
CLOUDS MAY HOLD UP LOW TEMPERATURES TUESDAY NIGHT. PLAYED OVERNIGHT
LOW TEMPERATURES FOR THE LOWER 50S IN THE NORTHERN MOUNTAINS TO THE
LOWER 60S IN THE PIEDMONT.
WEDNESDAY LOOKS MORE UNSTABLE WITH LIS AROUND MINUS 5 AND CAPES
POTENTIALLY EXCEEDING 2000 J/KG. INCREASED THE COVERAGE OF
THUNDERSTORMS WEDNESDAY. THE SWODY3 HAS MUCH OF THE CWA IN THE
SLIGHT RISK AHEAD OF THE COLD FRONT. THE MAIN THREAT WILL BE
DAMAGING WINDS. HIGH TEMPERATURES ON WEDNESDAY WILL BE WARMER THAN
TUESDAY WITH READINGS FROM THE UPPER 60S IN THE MOUNTAINS TO THE MID
70S IN THE PIEDMONT. TAPER POPS OFF WEDNESDAY NIGHT INTO THURSDAY.
LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE THE MID 40S IN THE
MOUNTAINS TO AROUND 60 DEGREES IN THE PIEDMONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 PM EDT SUNDAY...
ON THURSDAY...THE CLOSED UPPER LOW WILL BE OVER THE GREAT LAKES
WITH THE LARGE TROF COVERING MUCH OF THE CENTRAL AND EASTERN
UNITED STATES. THE PATTERN REMAINS AMPLIFIED THROUGH SATURDAY BUT
THE REX BLOCK WEAKENS...THE LOW OPENS UP AND THE TROF GRADUALLY
MOVES EAST BY SATURDAY. A SHORT WAVE TRACKING THROUGH THE BASE OF
THE UPPER TROF WILL MOVE ACROSS THE TENNESSEE VALLEY ON SATURDAY.
A STRONGER SHORT WAVE MOVES INTO THE TROF AXIS FROM SOUTHERN
CANADA AND CLOSES OFF OVER THE UPPER MISSISSIPPI VALLEY ON SUNDAY.
ECMWF WAS SHOWING A WAVE ALONG THE SURFACE FRONT WHICH WILL
LIKELY SLOW THE PASSAGE OF THE BOUNDARY ACROSS THE AREA ON
WEDNESDAY NIGHT AND THURSDAY. THE FRONT SHOULD BE WELL OFF THE
SOUTHEAST COAST ON FRIDAY. FRIDAY NIGHT THROUGH SUNDAY HIGH
PRESSURE IS BUILDING OVER THE GULF OF MEXICO AND THE SOUTHEAST
UNITED STATES.
MODELS STILL BRING UNSEASONABLY COLD AIR INTO THE AREA BEHIND THIS
SYSTEM ON THURSDAY NIGHT AND FRIDAY. SUNDAY MORNING HAS THE
POTENTIAL TO REACH WELL INTO THE 30S FOR LOWS IN THE MOUNTAINS.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 650 AM EDT MONDAY...
INCREASINGLY MOIST EASTERLY FLOW WILL CONTINUE TODAY WITH THE
CURRENT VFR CIGS/VSBYS DETERIORATING TOWARD MVFR ESPCLY ALONG THE
BLUE RIDGE AND POINTS EAST THROUGH LATE MORNING. DEEPER MOISTURE
ADVECTION SHOULD PRODUCE EVEN LOWER CIGS AND INCREASING
PRECIPITATION CHANCES AGAIN BY AFTERNOON WITH A LOBE OF SHOWERS
PROGGED TO MOVE EAST THROUGH THE AREA AHEAD OF ANOTHER MID LEVEL
WAVE ALOFT...WITH EVEN SOME CHANCE FOR THUNDER BUT MUCH BETTER
CHANCES TO OUR SOUTH AND WEST THIS AFTERNOON. LATEST GUIDANCE
SUGGESTS THAT ONCE THE INITIAL PATCHY RAINFALL EXITS AND THE WEDGE
BECOMES BETTER ENHANCED WILL SEE FLYING CONDITIONS QUICKLY WORSEN
THIS AFTERNOON WITH STRATUS/FOG DEVELOPING IN MANY LOCATIONS
MAKING FOR WIDESPREAD MVFR TO IFR FOR ALL SITES WITH LIFR POSSIBLE
ESPCLY AROUND BCB/ROA TO THE EAST. THIS MAY ACTUALLY OCCUR WITH
LACK OF PRECIP THIS EVENING AS THE MAIN BATCH OF CONVECTION AHEAD
OF THE FRONT ALOFT REMAINS OFF TO THE WEST.
POOR FLYING CONDITIONS WILL PREVAIL OVERNIGHT AS DEEP LAYER
MOISTURE ON EASTERLY FLOW GETS ENTRENCHED WITH PATCHY -RA/DZ AN
FOG AROUND MAKING FOR WIDESPREAD IFR/LIFR CIGS AND MVFR TO IFR
VSBYS OVERNIGHT. BANDS OF HEAVIER SHOWERS AND POSSIBLE
THUNDERSTORMS ARRIVE TUESDAY WITH WIDESPREAD SUB-VFR CONDITIONS
CONTINUING INTO TUESDAY EVENING.
EXTENDED AVIATION DISCUSSION...
THE MIDWEEK PERIOD WILL BE DOMINATED BY CLOUD COVER AS A DEEP
AREA OF LOW PRESSURE ALOFT SLOWLY DRIFTS INTO THE REGION FROM THE
WEST. SUB VFR CONDITIONS CAN BE EXPECTED AGAIN ON WEDNESDAY WITH
POTENTIAL FOR BANDS OF SHRA/TSRA IN ADDITION TO AREAS OF LIGHT
RAIN AND DRIZZLE NEAR THE BLUE RIDGE. APPEARS ENOUGH DRYING ALOFT
TO PERHAPS SEE IMPROVEMENT TO VFR ACROSS THE EAST LATER THURSDAY
INTO FRIDAY WITH MVFR LIKELY LINGERING AT TIMES ACROSS THE SE WEST
VA LOCATIONS INTO FRIDAY.
&&
.HYDROLOGY...
AS OF 300 PM EDT SUNDAY...
THERE IS A CHANCE FOR MAINSTEM RIVER FLOODING BY MID TO LATE THIS
WEEK. BUT STILL FAR TOO EARLY FOR HIGH CONFIDENCE IN WHICH RIVERS
AND HOW WIDESPREAD FLOODING WILL BE. STAY TUNED.
PATTERN SETTING UP WITH SOME IMPRESSIVE STRONG SIGNALS FOR A
PROLONGED PERIOD OF RAINFALL WITH HEAVY RAIN AMOUNTS BECOMING MORE
LIKELY...ESPECIALLY TUESDAY AFTERNOON INTO WEDNESDAY.
LATEST RUNS OF ENSEMBLE MODEL FORECAST FROM THE GEFS AND THE NAEFS
WERE SUGGESTING AN INCREASING PROBABILITY OF MODERATE RIVER FLOODING
ON THE DAN RIVER AT SOUTH BOSTON AND ON THE ROANOKE AT RANDOLPH.
FLOODING POSSIBILITIES ARE ALSO INDICATED FOR PARTS OF THE JAMES
AND GREENBRIER RIVER BASINS.
FLASH FLOODING APPEARS TO BE LESS OF A LIKELIHOOD AT LEAST AT THE
ONSET AS MUCH OF THE RAINFALL WILL BE OF THE STRATIFORM VARIETY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/PC/WP
NEAR TERM...JH
SHORT TERM...KK
LONG TERM...KK
AVIATION...JH/KM/PC/PM
HYDROLOGY...AMS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
402 AM EDT MON APR 28 2014
.SYNOPSIS...
A WEAK STATIONARY FRONT WILL REMAIN JUST SOUTH AND WEST OF THE
REGION TODAY INTO TUESDAY. A LARGE AND COMPLEX STORM SYSTEM
LOCATED OVER THE CENTRAL UNITED STATES WILL SLOWLY MOVE EAST. THIS
SYSTEM WILL PROVIDE RAINFALL FOR MUCH OF THE UPCOMING WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 250 AM EDT MONDAY...
WEAK BACKDOOR TYPE COLD FRONT NOW HEADING INTO THE SW PORTIONS OF
THE CWA WITH A STIFF EASTERLY FLOW DEVELOPING ESPCLY EAST OF THE
BLUE RIDGE WHERE BEST COOL ADVECTION WILL TAKE SHAPE THIS MORNING.
INIT MID LEVEL WAVE EJECTING OUT INTO THE SHORTWAVE RIDGING ALOFT
LIKELY TO HELP MOISTEN THE COLUMN EARLY ON WITH MAINLY JUST SPOTTY
-RA OR SPRINKLES INTO MID MORNING PER LATEST RADAR TRENDS. MAIN
SHOT AT MORE WIDESPREAD RAINFALL LOOKS TO COME FROM LATE MORNING
INTO MID AFTERNOON AS ANOTHER WAVE SLIDES BY TO THE NW AND HELPS
UPWARD MOTION SWING ACROSS THE NORTH UNDER A CORE OF SLIGHTLY
HIGHER 85H WINDS. MOST GUIDANCE ON TRACK WITH THIS FEATURE WITH
THE LATEST HRRR EXPANDING THIS AXIS EAST TO ALONG THE BLUE RIDGE
AROUND MIDDAY BEFORE TAKING IT TO THE EAST DURING THE AFTERNOON
ALONG THE GRADIENT OF THE THETA-E AXIS ALOFT. THUS HAVE INCLUDED
SOME CHANCE POPS MAINLY WEST EARLY THIS MORNING...THEN A PERIOD OF
LIKELYS FROM WEST TO EAST THROUGH LATE AFTERNOON WHEN SEE BEST
OVERRUNNING. HOWEVER QPF DOESNT LOOK TOO IMPRESSIVE WITH THIS
FEATURE WITH A TENTH TO A QUARTER INCH POSSIBLE WITH ANY THUNDER
FAR WEST AWAY FROM THE DEVELOPING EASTERN WEDGE. HIGH TEMPS REMAIN
TRICKY AS COULD SEE AREAS ACROSS THE NE ONLY RISE A FEW DEGREES
WHILE JUMPING ABOVE 70 ALONG THE I-77 CORRIDOR. WENT CLOSER TO THE
COLDER MET MOS ALONG/EAST OF THE BLUE RIDGE AND A BLEND OUT WEST.
IMPULSE EXITS BY THIS EVENING LEAVING MOST OF THE REGION IN A
STRONG WEDGE WITH ABSENCE OF MUCH LIFT WITH A BAND OF DEEPER
CONVECTION APPROACHING THE MOUNTAINS FROM THE WEST LATE. HOWEVER
SOUNDINGS SHOW A RATHER DEEP EAST/SE LOW LEVEL FLOW UNDER VEERING
ALOFT WHICH WOULD SUPPORT AT LEAST SPOTTY -RA/DZ OUTSIDE THE FAR
WEST WITH ADDED UPSLOPE LIKELY ENHANCING COVERAGE EASTERN SLOPES
OF THE BLUE RIDGE. WEAKENING SHRA/TSRA HEADED IN FROM THE WEST
AROUND DAYBREAK COULD REACH THE WESTERN SLOPES SO KEPT IN SOME
THUNDER MENTION ON THE PERIMETER OF THE WEDGE FOR NOW OVERNIGHT.
OTRW CLOUDY AND DAMP WITH PERIODS OF -RA/DZ AND PERHAPS A FEW MORE
-SHRA SW AS DEEPER WARM ADVECTION SPREADS NORTH ALOFT LATE. KEPT
LOWS CLOSER TO THE COOLER MET MOS AGAIN IN EXPECTING A STRONGER
WEDGE IN THE WAKE OF EARLIER RAINFALL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM EDT MONDAY...
DEEP UPPER CLOSED LOW OVER IOWA AND THE UPPER RIDGE ALONG THE EAST
COAST WILL MOVE EAST DURING THE PERIOD. THE MAIN LOW MOVES EAST
ACROSS THE GREAT LAKES WHILE A WAVE OF LOW PRESSURE ALONG THE
FRONTAL BOUNDARY WILL TRACK TOWARD THE MISSISSIPPI RIVER BY TUESDAY
EVENING.
PLENTY OF MOISTURE IS TRANSPORTED INTO THE REGION FROM THE ATLANTIC
OCEAN AT LOWEST LEVELS AND FROM THE GULF OF MEXICO THROUGH A DEEP
LAYER FARTHER ALOFT. HIGH TEMPERATURES ON TUESDAY ARE TRICKY
DEPENDING SUNSHINE AND AMOUNT OF RAIN. PLAYED HIGHS TOWARDS THE
COOLER ADJMET WITH VALUES FROM THE UPPER 50S ACROSS THE NORTH TO THE
LOWER 70S ACROSS THE SOUTH. THE SWODY2 HAS A FEW SOUTHEAST COUNTIES
IN THE SLIGHT RISK FOR SEVERE THUNDERSTORMS. APPEARS THAT THEY ARE
ALLOWING THE WEDGE TO WEAKEN ON THE SOUTHERN END FOR A FEW HOURS.
WITH THE STRENGHT OF THE WEDGE...GENERALLY UNDERDONE ON THE
MODELS...QUESTIONS ON WHETHER THE WEDGE MIXES OUT FOR A FEW HOURS
TUESDAY AFTERNOON.
BEST Q-V FORCING AND UPPER DIFFLUENCE IN THE RIGHT REAR QUADRANT OF
THE UPPER JET WILL BE TUESDAY NIGHT AND WEDNESDAY. PRECIPITABLE
WATER VALUES RISE TO AS HIGH AS 1.6 INCHES ACROSS THE SOUTHERN AND
EASTERN COUNTY WARNING AREA TUESDAY...WHICH IS AROUND TWO STANDARD
DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR. KEPT THE HIGHEST QPF
IN THE TUESDAY NIGHT TO WEDNESDAY TIME FRAME...SIMILAR TO WPC
GUIDANCE. HPC HAS PLACED EXCESSIVE RAINFALL POTENTIAL FOR DAY 2-3
ALONG AND EAST OF THE BLUE RIDGE. HOWEVER WILL HOLD OFF ON A FLOOD
WATCH FOR NOW GIVEN INTERVALS OF HEAVY RAIN AND WHERE EXCESSIVE
MAY OCCUR BASED ON RAINFALL THROUGH MONDAY NIGHT. THUS WILL
MENTION FLOODING POTENTIAL IN THE HWO FOR TUESDAY INTO WEDNESDAY.
CLOUDS MAY HOLD UP LOW TEMPERATURES TUESDAY NIGHT. PLAYED OVERNIGHT
LOW TEMPERATURES FOR THE LOWER 50S IN THE NORTHERN MOUNTAINS TO THE
LOWER 60S IN THE PIEDMONT.
WEDNESDAY LOOKS MORE UNSTABLE WITH LIS AROUND MINUS 5 AND CAPES
POTENTIALLY EXCEEDING 2000 J/KG. INCREASED THE COVERAGE OF
THUNDERSTORMS WEDNESDAY. THE SWODY3 HAS MUCH OF THE CWA IN THE
SLIGHT RISK AHEAD OF THE COLD FRONT. THE MAIN THREAT WILL BE
DAMAGING WINDS. HIGH TEMPERATURES ON WEDNESDAY WILL BE WARMER THAN
TUESDAY WITH READINGS FROM THE UPPER 60S IN THE MOUNTAINS TO THE MID
70S IN THE PIEDMONT. TAPER POPS OFF WEDNESDAY NIGHT INTO THURSDAY.
LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE THE MID 40S IN THE
MOUNTAINS TO AROUND 60 DEGREES IN THE PIEDMONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 PM EDT SUNDAY...
ON THURSDAY...THE CLOSED UPPER LOW WILL BE OVER THE GREAT LAKES
WITH THE LARGE TROF COVERING MUCH OF THE CENTRAL AND EASTERN
UNITED STATES. THE PATTERN REMAINS AMPLIFIED THROUGH SATURDAY BUT
THE REX BLOCK WEAKENS...THE LOW OPENS UP AND THE TROF GRADUALLY
MOVES EAST BY SATURDAY. A SHORT WAVE TRACKING THROUGH THE BASE OF
THE UPPER TROF WILL MOVE ACROSS THE TENNESSEE VALLEY ON SATURDAY.
A STRONGER SHORT WAVE MOVES INTO THE TROF AXIS FROM SOUTHERN
CANADA AND CLOSES OFF OVER THE UPPER MISSISSIPPI VALLEY ON SUNDAY.
ECMWF WAS SHOWING A WAVE ALONG THE SURFACE FRONT WHICH WILL
LIKELY SLOW THE PASSAGE OF THE BOUNDARY ACROSS THE AREA ON
WEDNESDAY NIGHT AND THURSDAY. THE FRONT SHOULD BE WELL OFF THE
SOUTHEAST COAST ON FRIDAY. FRIDAY NIGHT THROUGH SUNDAY HIGH
PRESSURE IS BUILDING OVER THE GULF OF MEXICO AND THE SOUTHEAST
UNITED STATES.
MODELS STILL BRING UNSEASONABLY COLD AIR INTO THE AREA BEHIND THIS
SYSTEM ON THURSDAY NIGHT AND FRIDAY. SUNDAY MORNING HAS THE
POTENTIAL TO REACH WELL INTO THE 30S FOR LOWS IN THE MOUNTAINS.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AS OF 1255 AM EDT MONDAY...
INCREASINGLY MOIST EASTERLY FLOW WILL CONTINUE OVERNIGHT INTO
MONDAY WITH THE CURRENT VFR CIGS/VSBYS DETERIORATING TOWARD MVFR
ESPCLY ALONG THE BLUE RIDGE AND POINTS EAST BY DAYBREAK. CONDITIONS
MAY IMPROVE MID- MORNING FOR SEVERAL HOURS BEFORE THE ONSET OF
LIGHT SHOWERS BY EARLY THIS MORNING AS A WEAK RIPPLE OF ENERGY
SLIDES ACROSS THE REGION PROVIDING ANOTHER BOOST TO LOW LEVEL
MOISTURE. BETTER MOISTURE ADVECTION SHOULD PRODUCE LOWER CIGS AND
INCREASING PRECIPITATION CHANCES AGAIN BY AFTERNOON WITH A LOBE OF
SHOWERS PROGGED TO MOVE EAST THROUGH THE AREA AHEAD OF ANOTHER
MID LEVEL WAVE ALOFT...WITH EVEN SOME CHANCE FOR THUNDER BUT MUCH
BETTER CHANCES TO OUR SOUTH AND WEST MONDAY AFTERNOON. LATEST
GUIDANCE SUGGESTS THAT ONCE THE INITIAL PATCHY RAINFALL EXITS AND
THE WEDGE BECOMES BETTER ENHANCED WILL SEE FLYING CONDITIONS
QUICKLY WORSEN LATER THIS AFTERNOON WITH STRATUS/FOG DEVELOPING IN
MANY LOCATIONS MAKING FOR WIDESPREAD MVFR TO IFR FOR ALL SITES
WITH LIFR POSSIBLE ESPCLY AROUND BCB/ROA TO THE EAST. THIS MAY
ACTUALLY OCCUR WITH LACK OF PRECIP THIS EVENING AS THE MAIN BATCH
OF CONVECTION AHEAD OF THE FRONT ALOFT REMAINS OFF TO THE WEST.
EXTENDED AVIATION DISCUSSION...
MUCH OF THE UPCOMING WEEK WILL BE DOMINATED BY CLOUD COVER AS
A DEEP AREA OF LOW PRESSURE ALOFT SLOWLY DRIFTS INTO THE REGION
FROM THE WEST. ONCE THIS SYSTEM ARRIVES...IT WILL LINGER ACROSS
THE REGION FOR SEVERAL DAYS. SUB VFR CONDITIONS CAN BE EXPECTED AT
INCREASING FREQUENCY AS THE WEEK PROGRESSES WITH POTENTIAL FOR
SCATTERED SHRA/TSRA IN ADDITION TO AREAS OF LIGHT RAIN AND DRIZZLE
NEAR THE BLUE RIDGE. APPEARS ENOUGH DRYING ALOFT TO PERHAPS SEE
IMPROVEMENT TO VFR ACROSS THE EAST LATER THURSDAY INTO FRIDAY WITH
MVFR LIKELY LINGERING AT TIMES ACROSS THE SE WEST VA LOCATIONS
INTO FRIDAY.
&&
.HYDROLOGY...
AS OF 300 PM EDT SUNDAY...
THERE IS A CHANCE FOR MAINSTEM RIVER FLOODING BY MID TO LATE THIS
WEEK. BUT STILL FAR TOO EARLY FOR HIGH CONFIDENCE IN WHICH RIVERS
AND HOW WIDESPREAD FLOODING WILL BE. STAY TUNED.
PATTERN SETTING UP WITH SOME IMPRESSIVE STRONG SIGNALS FOR A
PROLONGED PERIOD OF RAINFALL WITH HEAVY RAIN AMOUNTS BECOMING MORE
LIKELY...ESPECIALLY TUESDAY AFTERNOON INTO WEDNESDAY.
LATEST RUNS OF ENSEMBLE MODEL FORECAST FROM THE GEFS AND THE NAEFS
WERE SUGGESTING AN INCREASING PROBABILITY OF MODERATE RIVER FLOODING
ON THE DAN RIVER AT SOUTH BOSTON AND ON THE ROANOKE AT RANDOLPH.
FLOODING POSSIBILITIES ARE ALSO INDICATED FOR PARTS OF THE JAMES
AND GREENBRIER RIVER BASINS.
FLASH FLOODING APPEARS TO BE LESS OF A LIKELIHOOD AT LEAST AT THE
ONSET AS MUCH OF THE RAINFALL WILL BE OF THE STRATIFORM VARIETY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/PC/WP
NEAR TERM...JH
SHORT TERM...KK
LONG TERM...KK
AVIATION...JH/KM/PC/PM
HYDROLOGY...AMS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1023 PM CDT TUE APR 29 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 220 PM CDT TUE APR 29 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A LARGE
OCCLUDED CYCLONE SPINNING OVER EASTERN IOWA AND AN OCCLUDED FRONT
EXTENDING EAST ACROSS LOWER MICHIGAN. EARLIER BAND OF RAIN AND SNOW
THAT IMPACTED THE REGION THIS MORNING HAS PIVOTED AROUND TO THE
UPPER PENINSULA AND NORTHWEST WISCONSIN FOR THE MOST PART. STILL
SOME LIGHT RAIN AND LIGHT SNOW ONGOING OVER NORTH-CENTRAL WISCONSIN
WHERE EARLIER REPORTS INDICATE 1 TO 2 INCHES OF SNOW FELL. THOUGH
OBS ARE NOT NECESSARILY REPORTING IT...THINK A WIDESPREAD AREA OF
MIST AND DRIZZLE ARE OCCURRING ELSEWHERE. NEXT AREA OF SHOWERS IS
DEVELOPING OVER SOUTHERN WISCONSIN AND NORTHERN ILLINOIS AND ARE
BEGINNING TO ENTER THE SOUTHERN FORECAST AREA. STILL ANOTHER AREA
OF SHOWERS IS ROTATING AROUND THE UPPER LOW OVER NORTHERN
MISSOURI. TIMING OF SHOWERS IS THE MAIN FORECAST CONCERN.
TONIGHT...THE LARGE AND STUBBORN OCCLUDED CYCLONE WILL LIFT
NORTHEAST INTO SOUTHWEST WISCONSIN LATE TONIGHT. AHEAD OF THE
LOW...THE OCCLUDED FRONT WILL SHIFT NORTHWARD INTO CENTRAL
WISCONSIN. NEXT AREA OF RAINFALL IS TAKING SHAPE OVER SOUTHERN
WISCONSIN AND NORTHERN ILLINOIS AND SHOULD MOVE INTO CENTRAL AND
NORTHEAST WISCONSIN LATER THIS AFTERNOON INTO THIS EVENING. ANOTHER
SHORTWAVE WILL BE ROTATING AROUND THE UPPER LOW FROM NORTHERN
MISSOURI AND MOVE INTO NORTHEAST WISCONSIN LATE TONIGHT...WHICH
SHOULD BRING ADDITIONAL RAINFALL. A SILVER LINING IS THAT
TEMPERATURES WILL BE WARMING ALOFT...ENOUGH TO PRECLUDE A MENTION OF
SNOW. BUT WITH THE SURFACE LOW MOVING INTO THE STATE AND WIND
FIELDS WEAKENING...LOW STRATUS SHOULD BE GRADUALLY LOWERING THROUGH
THE NIGHT AND COULD SEE AREAS OF FOG DEVELOP OVER CENTRAL AND
EAST-CENTRAL WISCONSIN. LOWS IN THE MID 30S TO LOWER 40S.
WEDNESDAY...THE UPPER LOW WILL MEANDER NORTHEAST ACROSS THE FORECAST
AREA. THE SHORTWAVE ARRIVING LATE TONIGHT COULD BRING DECENT RAINS
INTO NORTHEAST WISCONSIN DURING THE MORNING BEFORE SHIFTING NORTH
INTO THE UPPER PENINSULA IN THE AFTERNOON. BUT THE PRESENCE OF THE
LOW SHOULD STILL GENERATE SCATTERED SHOWERS FOR THE AFTERNOON. SOME
MODERATION OF TEMPS COULD BRING HIGHS INTO THE MID 40S NORTH TO THE
LOW 50S SOUTH.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 220 PM CDT TUE APR 29 2014
PCPN TRENDS AND TEMPERATURES ARE THE MAIN FCST CONCERNS.
THE UPPER LEVEL LEVEL LOW IS EXPECTED TO DRIFT EAST ACROSS WI ON
WEDS NGT. SEVERAL MODELS SUGGEST THAT A WEAK DRY SLOT WILL BE IN
PLACE OVER EASTERN WI DURING THE EVENING...THEN GRADUALLY FILL IN
AS THE LOW SHIFTS EAST. WILL ADJUSTED POP TRENDS ACCORDINGLY...BUT
12 HOUR POPS WILL BE IN THE LIKELY CATEGORY OVER THE ENTIRE CWA.
WILL CONTINUE WITH LIKELY POPS ON THURSDAY AS THE UPPER LOW
WEAKENS OVER NE WI. PCPN WILL BECOME MORE SCATTERED ON THU NGT/FRI...
AS A COUPLE S/W TROFS AND A WEAK COLD FRONT TRAVERSE THE REGION.
GFS/ECMWF HAVE COME INTO BETTER AGREEMENT ON A DYNAMIC SYSTEM
AND COLD FRONT MOVG THROUGH WI ON SATURDAY. THE LFQ OF A 110 KT
JET STREAK AND A POTENT S/W TROF WILL MOVE THROUGH DURING THE
MIDDLE OF THE DAY. HAVE INCREASED POPS TO 50-60 PERCENT...AND
ADDED ISOLD THUNDER AS H7-H5 LAPSE RATES INCREASE TO 7 C/KM.
AFTER THE COLD FRONT MOVES THROUGH...CANADIAN HIGH PRESSURE WILL
BUILD INTO THE WESTERN GREAT LAKES...AND SHOULD BRING A RARE
PERIOD OF DRY WEATHER FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT.
AS THE CANADIAN HIGH SHIFTS EAST EARLY IN THE NEXT WORK WEEK...
SFC/H8 WARM FRONTS WILL WORK THEIR WAY TOWARD THE WI/IL BORDER.
THIS MAY BRING A SMALL OF SHOWERS...AND POSSIBLY ISOLD TSTMS
OVER OUR SOUTHERN COUNTIES. DUE TO LOW CONFIDENCE HAVE KEPT
THE MENTION OF THUNDER OUT OF THE FCST.
TEMPERATURES WILL REMAIN BLO NORMAL FOR MOST OF THE PERIOD.
WAA EARLY NEXT WEEK SHOULD ALLOW TEMPERATURES TO MODERATE A
LITTLE BIT. IF THE RAIN HOLDS OFF AND PARTIAL SUNSHINE OCCURS...
TEMPS MAY NEED TO BE RAISED ON MONDAY AND TUESDAY.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1023 PM CDT TUE APR 29 2014
A WEAKENING BUT LARGE UPPER LEVEL LOW PRESSURE SYSTEM
WILL DRIFT OVER THE GREAT LAKES REGION THE NEXT FEW DAYS. BANDS
OF SHOWERS WILL CONTINUE TO ROTATE AROUND THIS LOW PRESSURE
SYSTEM. DECREASING WINDS AND A MOIST COOL AIR MASS WILL CREATE
CIGS INTO THE LIFR RANGE. PATCHY DENSE FOG WILL ALSO BE
POSSIBLE...ESPECIALLY NEAR THE BAY OF GREEN BAY AND LAKE
MICHIGAN. EXPECT A SLOW IMPROVEMENT OF THE CIGS/VSBYS WEDNESDAY
MORNING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
629 PM CDT TUE APR 29 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 250 PM CDT TUE APR 29 2014
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED STRONG RIDGING ALONG THE U.S. WEST COAST THROUGH
SOUTHWEST CANADA...INTO HUDSON BAY AND NEW ENGLAND...WHILE AN
UPPER LOW WAS CUT OFF OVER THE FORECAST AREA. A DRY SLOT ROTATING
AROUND THE UPPER LOW HAS KICKED THE SHOWERS ALONG AND NORTH OF
I-90 THIS MORNING TO LAKE SUPERIOR AND BACK SOUTHWEST INTO
SOUTHWEST MN. MEANWHILE... UNDER THE UPPER LOW...SHOWERS HAVE
DEVELOPED OVER EASTERN IOWA INTO SOUTHERN WI. UPWARDS OF 250 J/KG
OF MOST UNSTABLE CAPE WAS DEPICTED BY RAP ANALYSIS SUPPORTING THE
SHOWERS. THIS PRECIPITATION WAS ALSO CO-LOCATED WITH A SURFACE LOW
NEW GRANT COUNTY WITH A WARM FRONT EXTENDING EAST TO KENOSHA WI
AND A COLD FRONT EXTENDING SOUTHWESTWARD. COLDER AIR CONTINUES TO
GET GRADUALLY WRAPPED AROUND THE UPPER LOW TOO...WITH THE 12Z MPX
AND INL SOUNDINGS REPORTING 925MB AND 850MB TEMPS BETWEEN 0 AND
-2C. THIS COLDER AIR ALLOWED FOR SOME LIGHT SNOW TO FALL NORTH OF
THE TWIN CITIES THIS MORNING. EVEN SOME SNOW FELL ALONG AND NORTH
OF I-90 THIS MORNING WHERE HEAVIER PRECIPITATION RESULTED IN
DYNAMIC AND EVAPORATIVE COOLING. MOST OF THE SNOW WAS CONFINED TO
GRASSY SURFACES.
VERY LITTLE CHANGE IS FORECAST IN THE UPPER LEVEL PATTERN TONIGHT
AND WEDNESDAY AS THE UPPER LOW BASICALLY MOVES NOWHERE. THIS LEAVES
SHORTWAVES ROTATING AROUND THE UPPER LOW TO IMPACT THE MOVEMENT OF
PRECIPITATION.
FOR TONIGHT...MAIN COLD CONVEYOR BELT AFFECTING MINNESOTA CURRENTLY
LOOKS TO WRAP BACK INTO MUCH OF SOUTHEAST MN AND NORTHEAST IOWA THIS
EVENING...THEN LINGER THROUGH THE OVERNIGHT HOURS WHILE POSSIBLY
BREAKING UP SOME. SOME OF THE COLD CONVEYOR BELT COULD WRAP INTO
SOUTHWEST AND CENTRAL WISCONSIN OVERNIGHT. COMBINATION OF NOCTURNAL
COOLING AND EVAPORATIVE COOLING FROM SOME LOW LEVEL DRY AIR
WRAPPING AROUND THE SURFACE LOW MAY ALLOW THE RAIN TO CHANGE OVER
TO SNOW...AS DEPICTED IN WET-BULB ZERO HEIGHT PROGS DROPPING BELOW
1000 FT. AUSTIN TO CHARLES CITY LOOKS TO HAVE THE HIGHEST
PROBABILITY OF SEEING SNOW ACCUMULATION. HOWEVER...LITTLE
ACCUMULATION IS ANTICIPATED SINCE THE PRECIPITATION IS EXPECTED TO
BE LIGHT AND THE GROUND IS WARM. TO THE EAST...THE SHOWERS ACROSS
SOUTHERN WISCONSIN SHOULD ROTATE INTO CENTRAL AND NORTHWEST
WISCONSIN THROUGH THE NIGHT. A SLIGHTLY COOLER NIGHT IS
LIKELY...PARTICULARLY WEST OF THE MISSISSIPPI RIVER DUE TO THE
COOLER AIR OVER MINNESOTA ROTATING AROUND THE UPPER LOW.
ON WEDNESDAY...THERE IS NO REAL STRONG IDENTIFICATION FEATURE FOR
PRODUCING PRECIPITATION...THOUGH MOST MODELS CONTINUE TO INDICATE
LIGHT SHOWER ACTIVITY AROUND. IT APPEARS MUCH OF THIS SHOWER
ACTIVITY IS LIKELY A INSTABILITY ISSUE...RESULTING FROM COLDER AIR
ALOFT FROM THE UPPER LOW. SCATTERED TO NUMEROUS SHOWERS SEEMS THE
BEST WAY TO DESCRIBE THE PRECIPITATION. 850MB TEMPS RANGING FROM -3C
WEST TO 2C EAST...PLENTY OF CLOUD COVER AND THE SHOWER ACTIVITY WILL
HELP TO KEEP TEMPERATURES DOWN WELL BELOW NORMAL AGAIN. SIDED
TOWARDS THE LOW SIDE OF TEMPERATURE GUIDANCE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 250 PM CDT TUE APR 29 2014
FOR THOSE LOOKING FOR A PATTERN CHANGE...ITS COMING...WITH GOOD
MODEL AGREEMENT FOR A SWITCH TO UPPER LEVEL RIDGING OVER THE
FORECAST AREA EARLY NEXT WEEK. SO THERE WILL BE A GRADUAL MODERATION
TO TEMPERATURES.
THE UPPER LOW LOOKS TO HANG AROUND THE FORECAST AREA WEDNESDAY
NIGHT...BUT THEN A MORE POTENT SHORTWAVE DROPPING DOWN THROUGH SOUTH
CENTRAL CANADA WILL HELP TO KICK THE UPPER LOW OUT TO THE NORTHEAST
ON THURSDAY. BY 00Z FRIDAY...MODELS HAVE THE UPPER LOW CENTERED OVER
LAKE HURON. UNTIL THE UPPER LOW DEPARTS...WE WILL NEED TO CONTEND
WITH SHOWER ACTIVITY ROTATING AROUND IT...ESPECIALLY THROUGH
THURSDAY MORNING. THERE ARE SOME INDICATIONS THAT THE SHOWER
ACTIVITY COULD DIMINISH WEST OF THE MISSISSIPPI RIVER THURSDAY
AFTERNOON FROM THE 29.00Z ECMWF AND 29.12Z CANADIAN...BUT THIS WILL
ALL HINGE ON HOW FAST THE UPPER LOW EJECTS. TEMPERATURES ARE STILL
GOING TO BE COOL THROUGH THURSDAY GIVEN 850MB TEMPS HOLDING BETWEEN -
2C AND 1C AND CLOUDS/SHOWERS. DESPITE THE COOL 850MB TEMPS...PROGGED
WETBULB ZERO HEIGHTS ARE ABOVE 1500 FT AGL...WHICH SHOULD KEEP SNOW
OUT OF THE PICTURE.
THE PLAGUE OF RAIN THAT HAS BEEN OVER THE AREA MAY FINALLY TAKE A
BREAK THURSDAY NIGHT AS SOME WEAK RIDGING BOTH AT THE SURFACE AND
ALOFT MOVES INTO THE AREA. CLOUD CLEARING LOOKS TO BE A BIT
SLOWER...AND POSSIBLY NOT EVEN CLEARING AT ALL IN WISCONSIN. IN
FACT...THE 29.12Z NAM SUGGESTS PERHAPS SOME DRIZZLE LINGERING IN
WISCONSIN AS A RESULT OF THESE CLOUDS HANGING AROUND. ALTHOUGH ITS
IN THE MINORITY OF MODEL GUIDANCE...FELT A 20 PERCENT CHANCE FOR
RAIN IS WARRANTED FOR WISCONSIN.
A WEAK SHORTWAVE IS PROGGED TO DROP SOUTHEAST THROUGH THE AREA ON
FRIDAY...IN THE NORTHWEST FLOW ALOFT BEHIND THE EJECTING UPPER LOW.
29.12Z GFS IS MOST AGGRESSIVE WITH PRODUCING SHOWERS WITH THIS
WAVE...BUT THE ECMWF HINTS AT POTENTIAL PRECIPITATION. KEPT SOME
LOWER PROBABILITIES IN FOR THIS WAVE TO ACCOUNT FOR THESE MODEL
SCENARIOS.
FOR THE WEEKEND...THE MAIN ITEM OF INTEREST IS THE AFOREMENTIONED
POTENT SHORTWAVE OVER SOUTH CENTRAL CANADA PROGGED TO BARREL THROUGH
NORTHERN PORTIONS OF THE UPPER GREAT LAKES SATURDAY AFTERNOON AND
EVENING. THERE ARE SOME MODEL DIFFERENCES ON SPEED AND
LOCATION...BUT ALL HAVE THE SAME IDEA. GIVEN THE POTENT NATURE OF
THE WAVE...PRECIPITATION LOOKS LIKELY...BUT THE DIFFERENCES CREATE
ISSUES WITH GOING TOO HIGH ON CHANCES. FEEL PRETTY CONFIDENT
NORTHERN WISCONSIN WILL SEE RAIN...BUT ELSEWHERE IT IS A BIT
UNCERTAIN. CANNOT RULE OUT SOME THUNDER EITHER WITH THE SHORTWAVE
GIVEN SOME STEEPER MID LEVEL LAPSE RATES PROGGED TO ACCOMPANY IT.
LOOKS LIKE BOTH SATURDAY NIGHT AND SUNDAY WILL THEN END UP DRY DUE
TO SUBSIDENCE BEHIND THE WAVE.
WITH THE RETURN TO UPPER RIDGING EARLY NEXT WEEK...ISENTROPIC LIFT
AND WARM ADVECTION COME INTO THE PICTURE. BOTH THE 29.12Z ECMWF AND
GFS DEPICT SOME LIGHT PRECIPITATION POSSIBLE FOR BOTH MONDAY AND
TUESDAY...ENOUGH TO WARRANT 20-30 PERCENT CHANCES. THE WARM
ADVECTION CLOUDS/PRECIPITATION AND A WARM FRONT SITUATED TO THE
SOUTH CLOSER TO I-70 WILL HOLD TEMPERATURES BACK FROM REACHING
NORMAL. NEVERTHELESS...THE TEMPERATURES EARLY NEXT WEEK LOOK TO BE
MUCH CLOSER TO NORMAL COMPARED TO NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 629 PM CDT TUE APR 29 2014
IFR TO LOW-END MVFR CONDITIONS WILL PERSIST THROUGH THE PERIOD AT
KRST/KLSE...AS RAIN SHOWERS PIVOT ACROSS THE AREA. WITH NIGHTTIME
COOLING...EXPECTING A LOWERING OF CEILINGS TO AROUND 500 FT AND
VISIBILITIES TO FALL INTO THE 3 TO 5SM RANGE. AT
KRST...PRECIPITATION IS LIKELY TO MIX WITH OR CHANGEOVER TO WET
SNOW AT TIMES THROUGH THE NIGHT. A MORE SNOW SCENARIO WOULD
FURTHER LOWER VISIBILITIES DOWN TO THE 1 TO 2SM RANGE. THE
NUMEROUS SHOWERS AND IFR CLOUD DECK WILL PERSIST INTO
WEDNESDAY...WITH LITTLE IMPROVEMENT EXPECTED. NORTHERLY WINDS
TONIGHT WILL BECOME WESTERLY TO SOUTHWESTERLY LATE TOMORROW AS
THE SURFACE LOW PUSHES TO THE NORTHEAST.
&&
.HYDROLOGY...
ISSUED AT 250 PM CDT TUE APR 29 2014
THE MAJORITY OF THE HEAVY RAIN HAS ENDED NOW FOR THE REST OF THE
WEEK...WHICH WILL GREATLY HELP DIMINISH THE CONCERN FOR FLOODING
ON TRIBUTARIES. RUNOFF IS EXPECTED TO RAISE WATER LEVELS ON THE
TRIBUTARIES BUT NO FLOODING IS ANTICIPATED FOR THEM.
MEANWHILE...PLENTIFUL RAIN THAT FELL UPSTREAM OVER CENTRAL
MINNESOTA COMBINED WITH THE RAIN THAT FELL OVER THE FORECAST AREA
WILL ALLOW THE MISSISSIPPI RIVER TO CONTINUE TO RISE. MANY SITES
ALONG THE MISSISSIPPI RIVER SHOULD RISE TO OR ABOVE FLOOD STAGE
OVER THE NEXT WEEK. FLOOD WATCHES AND WARNINGS ARE POSTED ALONG
THE MISSISSIPPI AS A RESULT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLOOD WATCH FROM SATURDAY EVENING THROUGH TUESDAY EVENING FOR
WIZ033-041-053-054-061.
MN...FLOOD WATCH FROM SATURDAY EVENING THROUGH TUESDAY EVENING FOR
MNZ088-096.
IA...FLOOD WATCH FROM SATURDAY EVENING THROUGH TUESDAY EVENING FOR
IAZ011-030.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....ZT
HYDROLOGY....AJ
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
610 PM CDT TUE APR 29 2014
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 220 PM CDT TUE APR 29 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A LARGE
OCCLUDED CYCLONE SPINNING OVER EASTERN IOWA AND AN OCCLUDED FRONT
EXTENDING EAST ACROSS LOWER MICHIGAN. EARLIER BAND OF RAIN AND SNOW
THAT IMPACTED THE REGION THIS MORNING HAS PIVOTED AROUND TO THE
UPPER PENINSULA AND NORTHWEST WISCONSIN FOR THE MOST PART. STILL
SOME LIGHT RAIN AND LIGHT SNOW ONGOING OVER NORTH-CENTRAL WISCONSIN
WHERE EARLIER REPORTS INDICATE 1 TO 2 INCHES OF SNOW FELL. THOUGH
OBS ARE NOT NECESSARILY REPORTING IT...THINK A WIDESPREAD AREA OF
MIST AND DRIZZLE ARE OCCURRING ELSEWHERE. NEXT AREA OF SHOWERS IS
DEVELOPING OVER SOUTHERN WISCONSIN AND NORTHERN ILLINOIS AND ARE
BEGINNING TO ENTER THE SOUTHERN FORECAST AREA. STILL ANOTHER AREA
OF SHOWERS IS ROTATING AROUND THE UPPER LOW OVER NORTHERN
MISSOURI. TIMING OF SHOWERS IS THE MAIN FORECAST CONCERN.
TONIGHT...THE LARGE AND STUBBORN OCCLUDED CYCLONE WILL LIFT
NORTHEAST INTO SOUTHWEST WISCONSIN LATE TONIGHT. AHEAD OF THE
LOW...THE OCCLUDED FRONT WILL SHIFT NORTHWARD INTO CENTRAL
WISCONSIN. NEXT AREA OF RAINFALL IS TAKING SHAPE OVER SOUTHERN
WISCONSIN AND NORTHERN ILLINOIS AND SHOULD MOVE INTO CENTRAL AND
NORTHEAST WISCONSIN LATER THIS AFTERNOON INTO THIS EVENING. ANOTHER
SHORTWAVE WILL BE ROTATING AROUND THE UPPER LOW FROM NORTHERN
MISSOURI AND MOVE INTO NORTHEAST WISCONSIN LATE TONIGHT...WHICH
SHOULD BRING ADDITIONAL RAINFALL. A SILVER LINING IS THAT
TEMPERATURES WILL BE WARMING ALOFT...ENOUGH TO PRECLUDE A MENTION OF
SNOW. BUT WITH THE SURFACE LOW MOVING INTO THE STATE AND WIND
FIELDS WEAKENING...LOW STRATUS SHOULD BE GRADUALLY LOWERING THROUGH
THE NIGHT AND COULD SEE AREAS OF FOG DEVELOP OVER CENTRAL AND
EAST-CENTRAL WISCONSIN. LOWS IN THE MID 30S TO LOWER 40S.
WEDNESDAY...THE UPPER LOW WILL MEANDER NORTHEAST ACROSS THE FORECAST
AREA. THE SHORTWAVE ARRIVING LATE TONIGHT COULD BRING DECENT RAINS
INTO NORTHEAST WISCONSIN DURING THE MORNING BEFORE SHIFTING NORTH
INTO THE UPPER PENINSULA IN THE AFTERNOON. BUT THE PRESENCE OF THE
LOW SHOULD STILL GENERATE SCATTERED SHOWERS FOR THE AFTERNOON. SOME
MODERATION OF TEMPS COULD BRING HIGHS INTO THE MID 40S NORTH TO THE
LOW 50S SOUTH.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 220 PM CDT TUE APR 29 2014
PCPN TRENDS AND TEMPERATURES ARE THE MAIN FCST CONCERNS.
THE UPPER LEVEL LEVEL LOW IS EXPECTED TO DRIFT EAST ACROSS WI ON
WEDS NGT. SEVERAL MODELS SUGGEST THAT A WEAK DRY SLOT WILL BE IN
PLACE OVER EASTERN WI DURING THE EVENING...THEN GRADUALLY FILL IN
AS THE LOW SHIFTS EAST. WILL ADJUSTED POP TRENDS ACCORDINGLY...BUT
12 HOUR POPS WILL BE IN THE LIKELY CATEGORY OVER THE ENTIRE CWA.
WILL CONTINUE WITH LIKELY POPS ON THURSDAY AS THE UPPER LOW
WEAKENS OVER NE WI. PCPN WILL BECOME MORE SCATTERED ON THU NGT/FRI...
AS A COUPLE S/W TROFS AND A WEAK COLD FRONT TRAVERSE THE REGION.
GFS/ECMWF HAVE COME INTO BETTER AGREEMENT ON A DYNAMIC SYSTEM
AND COLD FRONT MOVG THROUGH WI ON SATURDAY. THE LFQ OF A 110 KT
JET STREAK AND A POTENT S/W TROF WILL MOVE THROUGH DURING THE
MIDDLE OF THE DAY. HAVE INCREASED POPS TO 50-60 PERCENT...AND
ADDED ISOLD THUNDER AS H7-H5 LAPSE RATES INCREASE TO 7 C/KM.
AFTER THE COLD FRONT MOVES THROUGH...CANADIAN HIGH PRESSURE WILL
BUILD INTO THE WESTERN GREAT LAKES...AND SHOULD BRING A RARE
PERIOD OF DRY WEATHER FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT.
AS THE CANADIAN HIGH SHIFTS EAST EARLY IN THE NEXT WORK WEEK...
SFC/H8 WARM FRONTS WILL WORK THEIR WAY TOWARD THE WI/IL BORDER.
THIS MAY BRING A SMALL OF SHOWERS...AND POSSIBLY ISOLD TSTMS
OVER OUR SOUTHERN COUNTIES. DUE TO LOW CONFIDENCE HAVE KEPT
THE MENTION OF THUNDER OUT OF THE FCST.
TEMPERATURES WILL REMAIN BLO NORMAL FOR MOST OF THE PERIOD.
WAA EARLY NEXT WEEK SHOULD ALLOW TEMPERATURES TO MODERATE A
LITTLE BIT. IF THE RAIN HOLDS OFF AND PARTIAL SUNSHINE OCCURS...
TEMPS MAY NEED TO BE RAISED ON MONDAY AND TUESDAY.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 610 PM CDT TUE APR 29 2014
A LARGE UPPER LEVEL LOW PRESSURE SYSTEM WILL
GRADUALLY MOVE NORTHEAST INTO THE WESTERN GREAT LAKES LATE TONIGHT
INTO WEDNESDAY. THIS LOW WILL CONTINUE TO SEND BANDS OF
PRECIPITATION ACROSS NORTH CENTRAL AND NORTHEAST WISCONSIN THROUGH
WEDNESDAY. ALSO TONIGHT A SURFACE LOW PRESSURE SYSTEM WILL DRIFT INTO
THE WESTERN GREAT LAKES REGION. LIGHTER WINDS AND AN INFLUX OF
MOISTURE WILL LIKELY LOWER CIGS INTO THE LIFR RANGE. DENSE FOG IS
ALSO POSSIBLE...ESPECIALLY NEAR THE BAY OF GREEN BAY AND LAKE
MICHIGAN. EXPECT A SLOW IMPROVEMENT OF THE CIGS/VSBYS WEDNESDAY
MORNING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT MON APR 28 2014
.SHORT TERM...(TONIGHT AND TUESDAY)
ISSUED AT 322 PM CDT MON APR 28 2014
WATCHING THE FRONTAL STRUCTURE TO THE SOUTH CLOSELY AND
INSTABILITY TO SEE IF CHANGES IN SEVERE WEATHER FORECASTS NEED TO
BE CHANGED...AND TRYING TO BUILD IN BETTER TIMING OVERNIGHT FOR
NEXT WAVE OF RAIN. WINDS STILL STRONG...BUT THOSE SHOULD BE
DECREASING AFTER MIDNIGHT.
GOES WATER VAPOR IMAGERY SHOWING THE MAIN LONG WAVE ANCHORED NEAR
CENTRAL NEB WITH A NUMBER OF SHORTWAVE TROUGHS WITHIN THE LARGE
TROUGH AREA MOVING NORTH THROUGH IA/MO. IT APPEARS ONE SMALLER CURL
CAN BE SEEN IN NERN MO HEADING NORTH. THE AREA HAS BEEN UNDER
300-500MB QG CONVERGENCE LIFT AHEAD OF THIS BROAD TROUGH SPOKE
ROTATING NORTHWARD...WITH ISENTROPIC LIFT IN THE LOW-LEVELS NORTH
OF THE WARM FRONT...AND THE RAIN TODAY NOW LIFTING NORTH. THE
WARM FRONT CONTINUES TO HOLD NEARLY IN PLACE SOUTH OF I-80 AT 19Z.
MEANWHILE THE COLD FRONT FROM OMAHA TO CENTRAL MO WAS CLEAR ON
VISIBLE IMAGERY AND CONVECTING NOW...AND OVER THE PAST HOURS THE
OCCLUSION AND TRIPLE POINT ARE RIPPING EAST...NOW NEAR KDSM. THE
STORMS ON THIS OCCLUSION AND COLD FRONT WILL ROTATE NORTHWARD
TONIGHT INTO THE FORECAST AREA. 12Z RAOB PRECIPITABLE WATER VALUES
ARE NOT AS HIGH AS THE MORNING MODEL INITIALIZATIONS...WITH THE
28.12Z GFS/NAM SHOWING A 1-1.25 INCH PLUME FROM NRN IL INTO SERN
MN. KMPX WAS ONLY 0.62 AT 12Z FROM THE RAOB. 1500 FT WINDS OF AREA
88D VAD WINDS ARE STILL IN THE 40-50KT RANGE FROM KMKX-
KMPX...EXPLAINING THE CONTINUED WIND GUSTS IN THE 30S MPH.
AS THE LATER AFTERNOON PROGRESSES...THE COLD FRONT WILL CONTINUE
THE OCCLUSION PROGRESSES SEWRD TOWARD IL. BY EVENING THE TRIPLE
POINT SHOULD BE WELL INTO IL WITH A BAND OF TSRA ALONG AND NORTH
OF THE OCCLUSION HEADING NORTH TOWARD THE AREA. THE OCCLUSION
BOUNDARY STAYS NEAR I-80 IN THE LATEST HRRR RUNS...WITH THE
ELEVATED TSRA AND PRECIPITATION BAND ROTATING INTO MN/WI. THE
MOST UNSTABLE CAPE ANALYSIS SHOWS 250 J/KG IN THE SOUTHERN
FORECAST AREA AT 20Z...WITH ABOUT 500 J/KG APPROACHING THE
SOUTHERN FORECAST AREA. AS WITH DAYS PAST...AS THIS TSRA BAND
APPROACHES NERN IA AND SWRN WI AFTER 5 PM...CONVECTIVE ACTIVITY
IS EXPECTED TO DEGRADE. SOME SMALL HAIL IS POSSIBLE FROM THE
STORMS IN THE SOUTHERN FORECAST AREA...BUT THEN A TRANSITION TO A
MORE STRATIFORM RAIN REGION WILL OCCUR.
THERE IS EXCELLENT AGREEMENT ON THE MODEL GUIDANCE ON THE BAND
ROTATING NORTH THROUGH THE AREA OVERNIGHT. HAVE FORECAST AMOUNTS
OF LESS THAN ONE-HALF OF AN INCH. WITH MODELS TOO HIGH ON
PRECIPITABLE WATER...HAVE DISCOUNTED HEAVIER RAINFALL TOTALS SUCH
AS THE 28.12Z. THE BAND WILL ROTATE INTO THE NORTHERN FORECAST
AREA TUESDAY MORNING AND SLOW ITS PROGRESS AS THE SURFACE LOW
SHIFTS TOWARD ROCKFORD IL. THIS WILL PROVIDE A QUICK WARM UP TO
THE BOUNDARY LAYER AND SOME INSTABILITY ACROSS SOUTHWEST WI FOR A
TIME TUESDAY. HAVE ADDED SOME THUNDER THERE BUT DO NOT EXPECT MORE
THAN PEA SIZED HAIL WITH 250 J/KG OF CAPE OR SO.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 322 PM MON APR 28 2014
TUESDAY NIGHT THROUGH THURSDAY NIGHT
THE AREA WILL BE RIGHT UNDER THE OCCLUDED DEEP LOW WITH SPOKES OF
ENERGY CONTINUING TO ROTATE THROUGH THE AREA. THE MODEL GUIDANCE
AGREES ON THE BIG PICTURE BUT THE DETAILS OF TIMING ON RAIN
CHANCES ARE ALL OVER THE PLACE AMONG ALL THE AVAILABLE MODELS.
HAVE KEPT THIS PERIOD SHOWERY WITH MUCH LIGHTER WINDS THAN WE HAVE
SEEN. FAIRLY SATURATED CONDITIONS AND SHORTWAVES THAT WILL BE
ROTATING THROUGH THE LONG WAVE WILL BRING MORE ORGANIZED SHOWER
AREAS I AM SURE. AT THIS POINT...RAISED RAIN CHANCES THROUGH THIS
PERIOD TO AT LEAST 60 PERCENT WITH MORE DETAIL TO BE ADDED AS WE
GET CLOSER TO THOSE DAYS AND CAN IDENTIFY WHERE TO IMPROVE THE
FORECAST. COOL AND CLOUDY WITH LIGHT RAINFALL /LESS THAN ONE
TENTH PER 12 HOURS/ FOR MOST EVERYWHERE.
FRIDAY THROUGH MONDAY
A BELOW NORMAL TEMPERATURE PERIOD. LONG WAVE TROUGH AND SHORTWAVE
ACTIVITY SPOKING AROUND THE LOW WILL MAKE FOR DETAILS IN THIS
PERIOD DIFFICULT. BY FRIDAY IT WOULD APPEAR THE MODEL CONSENSUS
SUGGEST THE AREA INTO NORTHWEST FLOW WHICH CAUSES ITS OWN ISSUES
FOR TIMING OF SHOWERS WITH SHORTWAVE TROUGHS. HEIGHTS RISE MORE
OVER THE GREAT LAKES ON FRIDAY NIGHT AND SATURDAY AS ENERGY
CRASHES ONTO THE WEST COAST. THIS ENERGY THEN EJECTS INTO THE
PLAINS BY LATER SATURDAY WITH CYCLOGENESIS AND SOUTHERLY RETURN
FLOW ACTIVATING ON THE FRONT TO THE SOUTHWEST. FOR A 150 HOUR
FORECAST...THERE IS PRETTY GOOD AGREEMENT WITH THE LATEST TWO RUNS
OF THE ECMWF/GFS MODELS THAT SHOWERS/RAIN WILL SPREAD ACROSS THE
REGION SUNDAY WITH THE NORMAL WARM FRONTAL LIFT SIGNALS OF
ISENTROPIC LIFT...MOISTURE TRANSPORT CONVERGENCE. WHILE PLACEMENT
IS VARIED...THE GENERAL AGREEMENT ADDS TO CONFIDENCE. BOTTOM LINE
IS SATURDAY LOOKS LIKE THE DRIER DAY STILL BUT CONFIDENCE IS
SOMEWHAT LOW WITH NORTHWEST FLOW VERY DIFFICULT TO FORECAST 5 DAYS
OUT. TEMPERATURES DONT LOOK TO REBOUND MUCH UNTIL SATURDAY...BUT
CLOUDS MAKE ALL THE DIFFERENCE THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 600 PM CDT MON APR 28 2014
CLOSED...VERTICALLY STACKED LOW WILL BE THE WEATHER MAKER OVER THE
NEXT FEW DAYS. THIS WILL KEEP KRST/KLSE UNDER A PROLONGED PERIOD OF
MVFR/IFR CIGS...WITH BOUTS OF MVFR VSBYS DURING -SHRA/RA.
WINDS WILL STAY STRONG TONIGHT...BUT AS THE LOW INCHES NORTHWARD
TUE...EXPECT SOME SLACKENING IN THE PRESSURE GRADIENT...AND A
REDUCTION IN WIND SPEEDS. DIRECTION WILL BECOME MORE NORTHERLY
TUE...THEN SHIFTING NORTHWEST LATE TUE NIGHT. LLWS REMAINS A CONCERN
AT KLSE WITH AROUND 50 KTS AT 2 KFT. WILL CONTINUE A MENTION IN
FORECAST INTO THE OVERNIGHT HOURS.
&&
.HYDROLOGY...
ISSUED AT 322 PM CDT MON APR 28 2014
AFTER RECEIVING LESS RAIN OVERNIGHT THAN ORIGINALLY THOUGHT...THE RIVER
SITUATION SEEMS LIKE IT WILL BEHAVE FOR THIS STORM. WE ARE EXPECTING
ABOUT 0.50 TO 0.75 INCHES OF RAIN TONIGHT AND TUESDAY FOR MOST AREAS
WHICH WILL MEAN BANKFULL RIVER RISES FOR MOST RIVERS...AND A LOW FLOODING
THREAT. THE KICKAPOO MAY BE THE CLOSEST RIVER TO FLOODING.
MAYBE THE MAIN STORY IS THE MISSISSIPPI RIVER THAT WILL SWALLOW
ALL THE INCOMING TRIBUTARY WATER AND CONTINUE TO RISE ALL NEXT
WEEK. FROM WINONA MN SOUTH...IT APPEARS THE MISSISSIPPI RIVER WILL
BE APPROACHING MINOR FLOOD LEVELS BY LATER THIS WEEK...WITH FLOODING
LIKELY FURTHER NORTH. THE FLOOD WATCH HAS BEEN ISSUED FOR THE
WINONA AND SOUTH FLOODING THREAT.
AFTER TONIGHT...RAINFALL AMOUNTS WILL TURN MORE SHOWERY AS THE
GULF MOISTURE PLUME IS SHUNTED EAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR
WIZ041-053-054-061.
MN...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR
MNZ088-096.
IA...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR
IAZ011-030.
&&
SHORT TERM...BAUMGARDT
LONG TERM....BAUMGARDT
AVIATION.....RIECK
HYDROLOGY....BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
323 PM CDT MON APR 28 2014
.SHORT TERM...(TONIGHT AND TUESDAY)
ISSUED AT 322 PM CDT MON APR 28 2014
WATCHING THE FRONTAL STRUCTURE TO THE SOUTH CLOSELY AND
INSTABILITY TO SEE IF CHANGES IN SEVERE WEATHER FORECASTS NEED TO
BE CHANGED...AND TRYING TO BUILD IN BETTER TIMING OVERNIGHT FOR
NEXT WAVE OF RAIN. WINDS STILL STRONG...BUT THOSE SHOULD BE
DECREASING AFTER MIDNIGHT.
GOES WATER VAPOR IMAGERY SHOWING THE MAIN LONG WAVE ANCHORED NEAR
CENTRAL NEB WITH A NUMBER OF SHORTWAVE TROUGHS WITHIN THE LARGE
TROUGH AREA MOVING NORTH THROUGH IA/MO. IT APPEARS ONE SMALLER CURL
CAN BE SEEN IN NERN MO HEADING NORTH. THE AREA HAS BEEN UNDER
300-500MB QG CONVERGENCE LIFT AHEAD OF THIS BROAD TROUGH SPOKE
ROTATING NORTHWARD...WITH ISENTROPIC LIFT IN THE LOW-LEVELS NORTH
OF THE WARM FRONT...AND THE RAIN TODAY NOW LIFTING NORTH. THE
WARM FRONT CONTINUES TO HOLD NEARLY IN PLACE SOUTH OF I-80 AT 19Z.
MEANWHILE THE COLD FRONT FROM OMAHA TO CENTRAL MO WAS CLEAR ON
VISIBLE IMAGERY AND CONVECTING NOW...AND OVER THE PAST HOURS THE
OCCLUSION AND TRIPLE POINT ARE RIPPING EAST...NOW NEAR KDSM. THE
STORMS ON THIS OCCLUSION AND COLD FRONT WILL ROTATE NORTHWARD
TONIGHT INTO THE FORECAST AREA. 12Z RAOB PRECIPITABLE WATER VALUES
ARE NOT AS HIGH AS THE MORNING MODEL INITIALIZATIONS...WITH THE
28.12Z GFS/NAM SHOWING A 1-1.25 INCH PLUME FROM NRN IL INTO SERN
MN. KMPX WAS ONLY 0.62 AT 12Z FROM THE RAOB. 1500 FT WINDS OF AREA
88D VAD WINDS ARE STILL IN THE 40-50KT RANGE FROM KMKX-
KMPX...EXPLAINING THE CONTINUED WIND GUSTS IN THE 30S MPH.
AS THE LATER AFTERNOON PROGRESSES...THE COLD FRONT WILL CONTINUE
THE OCCLUSION PROGRESSES SEWRD TOWARD IL. BY EVENING THE TRIPLE
POINT SHOULD BE WELL INTO IL WITH A BAND OF TSRA ALONG AND NORTH
OF THE OCCLUSION HEADING NORTH TOWARD THE AREA. THE OCCLUSION
BOUNDARY STAYS NEAR I-80 IN THE LATEST HRRR RUNS...WITH THE
ELEVATED TSRA AND PRECIPITATION BAND ROTATING INTO MN/WI. THE
MOST UNSTABLE CAPE ANALYSIS SHOWS 250 J/KG IN THE SOUTHERN
FORECAST AREA AT 20Z...WITH ABOUT 500 J/KG APPROACHING THE
SOUTHERN FORECAST AREA. AS WITH DAYS PAST...AS THIS TSRA BAND
APPROACHES NERN IA AND SWRN WI AFTER 5 PM...CONVECTIVE ACTIVITY
IS EXPECTED TO DEGRADE. SOME SMALL HAIL IS POSSIBLE FROM THE
STORMS IN THE SOUTHERN FORECAST AREA...BUT THEN A TRANSITION TO A
MORE STRATIFORM RAIN REGION WILL OCCUR.
THERE IS EXCELLENT AGREEMENT ON THE MODEL GUIDANCE ON THE BAND
ROTATING NORTH THROUGH THE AREA OVERNIGHT. HAVE FORECAST AMOUNTS
OF LESS THAN ONE-HALF OF AN INCH. WITH MODELS TOO HIGH ON
PRECIPITABLE WATER...HAVE DISCOUNTED HEAVIER RAINFALL TOTALS SUCH
AS THE 28.12Z. THE BAND WILL ROTATE INTO THE NORTHERN FORECAST
AREA TUESDAY MORNING AND SLOW ITS PROGRESS AS THE SURFACE LOW
SHIFTS TOWARD ROCKFORD IL. THIS WILL PROVIDE A QUICK WARM UP TO
THE BOUNDARY LAYER AND SOME INSTABILITY ACROSS SOUTHWEST WI FOR A
TIME TUESDAY. HAVE ADDED SOME THUNDER THERE BUT DO NOT EXPECT MORE
THAN PEA SIZED HAIL WITH 250 J/KG OF CAPE OR SO.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 322 PM MON APR 28 2014
TUESDAY NIGHT THROUGH THURSDAY NIGHT
THE AREA WILL BE RIGHT UNDER THE OCCLUDED DEEP LOW WITH SPOKES OF
ENERGY CONTINUING TO ROTATE THROUGH THE AREA. THE MODEL GUIDANCE
AGREES ON THE BIG PICTURE BUT THE DETAILS OF TIMING ON RAIN
CHANCES ARE ALL OVER THE PLACE AMONG ALL THE AVAILABLE MODELS.
HAVE KEPT THIS PERIOD SHOWERY WITH MUCH LIGHTER WINDS THAN WE HAVE
SEEN. FAIRLY SATURATED CONDITIONS AND SHORTWAVES THAT WILL BE
ROTATING THROUGH THE LONG WAVE WILL BRING MORE ORGANIZED SHOWER
AREAS I AM SURE. AT THIS POINT...RAISED RAIN CHANCES THROUGH THIS
PERIOD TO AT LEAST 60 PERCENT WITH MORE DETAIL TO BE ADDED AS WE
GET CLOSER TO THOSE DAYS AND CAN IDENTIFY WHERE TO IMPROVE THE
FORECAST. COOL AND CLOUDY WITH LIGHT RAINFALL /LESS THAN ONE
TENTH PER 12 HOURS/ FOR MOST EVERYWHERE.
FRIDAY THROUGH MONDAY
A BELOW NORMAL TEMPERATURE PERIOD. LONG WAVE TROUGH AND SHORTWAVE
ACTIVITY SPOKING AROUND THE LOW WILL MAKE FOR DETAILS IN THIS
PERIOD DIFFICULT. BY FRIDAY IT WOULD APPEAR THE MODEL CONSENSUS
SUGGEST THE AREA INTO NORTHWEST FLOW WHICH CAUSES ITS OWN ISSUES
FOR TIMING OF SHOWERS WITH SHORTWAVE TROUGHS. HEIGHTS RISE MORE
OVER THE GREAT LAKES ON FRIDAY NIGHT AND SATURDAY AS ENERGY
CRASHES ONTO THE WEST COAST. THIS ENERGY THEN EJECTS INTO THE
PLAINS BY LATER SATURDAY WITH CYCLOGENESIS AND SOUTHERLY RETURN
FLOW ACTIVATING ON THE FRONT TO THE SOUTHWEST. FOR A 150 HOUR
FORECAST...THERE IS PRETTY GOOD AGREEMENT WITH THE LATEST TWO RUNS
OF THE ECMWF/GFS MODELS THAT SHOWERS/RAIN WILL SPREAD ACROSS THE
REGION SUNDAY WITH THE NORMAL WARM FRONTAL LIFT SIGNALS OF
ISENTROPIC LIFT...MOISTURE TRANSPORT CONVERGENCE. WHILE PLACEMENT
IS VARIED...THE GENERAL AGREEMENT ADDS TO CONFIDENCE. BOTTOM LINE
IS SATURDAY LOOKS LIKE THE DRIER DAY STILL BUT CONFIDENCE IS
SOMEWHAT LOW WITH NORTHWEST FLOW VERY DIFFICULT TO FORECAST 5 DAYS
OUT. TEMPERATURES DONT LOOK TO REBOUND MUCH UNTIL SATURDAY...BUT
CLOUDS MAKE ALL THE DIFFERENCE THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 1215 PM CDT MON APR 28 2014
AN EXTENDED PERIOD OF MVFR/IFR CIGS SETTING UP FOR THE TAF SITES.
THIS AS A LARGE/COLD/MOIST SFC TO MID LEVEL LOW OVER THE CENTRAL
PLAINS DRIFTS SLOWLY NORTHEAST INTO THE UPPER MIDWEST. MAINLY VFR
VSBYS EXPECTED AS BRISK...BUT DRIER...EASTERLY BECOMING NORTHEAST
AND NORTH SFC-925MB FLOW CONTINUES OVER SOUTHEAST MN/WESTERN WI THRU
TONIGHT/TUE. SOME MVFR/LCL IFR VSBYS EXPECTED IN BANDS OF HEAVIER
RAIN AS THEY ROTATE NORTH AND NORTHWEST ACROSS THE AREA. ONE OF
THESE TO IMPACT THE TAF SITES INTO THE EARLY AFTERNOON HOURS
TODAY...WITH ANOTHER EXPECTED TO LIFT NORTH ACROSS THE TAF SITES
DURING THE LATER EVENING AND OVERNIGHT HOURS. GENERALLY LIGHTER
PRECIP EXPECTED TUE WITH MAINLY VFR VSBYS.
TIGHT PRESSURE GRADIENT AND BRISK/GUSTY EAST WINDS WILL PERSIST
ACROSS THE TAF SITS THIS AFTERNOON/EVENING. AS THE SFC LOW MOVES
INTO EASTERN IA/NORTHERN IL LATER TONIGHT/TUE...PRESSURE GRADIENT
OVER THE AREA WILL RELAX WITH WINDS STILL BRISK BUT MORE IN THE 10-
20KT RANGE AND BECOMING NORTHEAST TO NORTH.
&&
.HYDROLOGY...
ISSUED AT 322 PM CDT MON APR 28 2014
AFTER RECEIVING LESS RAIN OVERNIGHT THAN ORIGINALLY THOUGHT...THE RIVER
SITUATION SEEMS LIKE IT WILL BEHAVE FOR THIS STORM. WE ARE EXPECTING
ABOUT 0.50 TO 0.75 INCHES OF RAIN TONIGHT AND TUESDAY FOR MOST AREAS
WHICH WILL MEAN BANKFULL RIVER RISES FOR MOST RIVERS...AND A LOW FLOODING
THREAT. THE KICKAPOO MAY BE THE CLOSEST RIVER TO FLOODING.
MAYBE THE MAIN STORY IS THE MISSISSIPPI RIVER THAT WILL SWALLOW
ALL THE INCOMING TRIBUTARY WATER AND CONTINUE TO RISE ALL NEXT
WEEK. FROM WINONA MN SOUTH...IT APPEARS THE MISSISSIPPI RIVER WILL
BE APPROACHING MINOR FLOOD LEVELS BY LATER THIS WEEK...WITH FLOODING
LIKELY FURTHER NORTH. THE FLOOD WATCH HAS BEEN ISSUED FOR THE
WINONA AND SOUTH FLOODING THREAT.
AFTER TONIGHT...RAINFALL AMOUNTS WILL TURN MORE SHOWERY AS THE
GULF MOISTURE PLUME IS SHUNTED EAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR
WIZ041-053-054-061.
MN...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR
MNZ088-096.
IA...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR
IAZ011-030.
&&
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...SWERMAN
HYDROLOGY...BAUMGARDT
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 240 PM CDT MON APR 28 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A LARGE AND
STUBBORN UPPER LOW SPINNING OVER THE CENTRAL GREAT PLAINS AND A WARM
FRONT POSITIONED OVER CENTRAL IOWA TO CENTRAL INDIANA. WARM
CONVEYOR BELT IS RISING OVER THE 850MB FRONT LOCATED OVER SOUTHERN
WISCONSIN AND ALONG WITH MID-LEVEL FGEN...IS HELPING TO PRODUCE AN
ARCING BAND OF RAIN FROM CENTRAL MINNESOTA TO CENTRAL LOWER
MICHIGAN. THIS BAND HAS BEEN SLOWING LIFTING NORTH TODAY WITH
ASSISTANCE FROM A SHORTWAVE LOBE OVER IOWA...WHICH IS ROTATING
AROUND THE PARENT CYCLONE. THIS BAND WILL CONTINUE TO LIFT NORTH
AND COULD REACH THE U.P BORDER BY THE END OF THE AFTERNOON. FAR
NORTHERN WISCONSIN HAS BEEN DRY SO FAR TODAY WHERE TEMPS HAVE RISEN
INTO THE LOWER 50S...BUT THIS SHOULD END SOON. PRECIP TRENDS AND
AMOUNTS REMAIN THE MAIN FORECAST CONCERNS.
TONIGHT...SLOW MOVING UPPER LOW OVER THE CENTRAL GREAT PLAINS WILL
CONTINUE ITS SLOW JAUNT TO THE EAST. EAST OF THIS UPPER LOW...850MB
WARM FRONT WILL LIFT NORTH INTO CENTRAL AND NORTHEAST WISCONSIN
WHILE THE LEFT FRONT QUAD OF A JET STREAK WILL PUSH NORTHWARD ACROSS
WISCONSIN. PLENTY OF MID-LEVEL FGEN AND UPPER DIVERGENCE WITHIN THE
PWAT MAXIMUM BAND TO SUPPORT THE ARCING BAND OF RAIN OVER THE
WESTERN GREAT LAKES TO LIFT SLOWLY NORTHWARD THROUGH THE NIGHT. A
HALF INCH TO AN INCH OF RAIN IS POSSIBLE ACROSS CENTRAL AND
EAST-CENTRAL WISCONSIN THAT WILL LIKELY AGGRAVATE RIVER FLOODING.
AS THE PRECIP MOVES INTO NORTHERN WISCONSIN TONIGHT AND THE BOUNDARY
LAYER COOLS...PROGGED SOUNDINGS LOOK COLD ENOUGH FOR WET SNOW FLAKES
TO MIX IN WITH THE RAIN. PERHAPS COULD SEE A LITTLE COATING ON
GRASSY SURFACES BUT TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING SO
HARD TO SEE ANY ACCUMULATION ON ROADWAYS. WINDS WILL REMAIN GUSTY
AND ACTUALLY INCREASE LATE TONIGHT OVER THE FOX VALLEY AS THE
TRAJECTORIES TURN NORTHEAST AND FUNNEL DOWN THE BAY. WILL HAVE
GUSTS UP TO 40 MPH LATE. LOWS IN THE MID TO UPPER 30S.
TUESDAY...THE UPPER LOW WILL NOSE ITS WAY INTO THE SOUTHWESTERN GREAT
LAKES. OTHERWISE...LITTLE CHANGES SYNOPTICALLY. WILL HAVE A STRONG
SHORTWAVE ROTATE AROUND THE UPPER LOW INTO NORTHERN LAKE MICHIGAN
DURING THE AFTERNOON WHICH WILL PUSH A 850MB TROUGH INTO NORTHEAST
WISCONSIN. THIS MAY BRING BREAKS IN THE RAIN AND DIMINISHING WINDS
OVER EAST-CENTRAL AND NORTHEAST WISCONSIN DURING THE PM HOURS...BUT
EXPECT THE STEADY RAINS TO CONTINUE OVER NORTH-CENTRAL WISCONSIN
THROUGH THE DAY. SOME RAIN WILL STILL HAVE SOME SNOW MIXED IN
DURING THE MORNING HOURS. ANOTHER QUARTER TO A HALF INCH OF RAIN
APPEARS POSSIBLE. HIGHS RANGING FROM AROUND 40 NORTH TO NEAR 50S
SOUTH.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 240 PM CDT MON APR 28 2014
PCPN TRENDS AND TEMPERATURES ARE THE MAIN FCST CONCERNS.
THE UPPER LEVEL LOW IS EXPECTED TO LINGER OVER THE WESTERN GREAT
LAKES THROUGH THURSDAY...THEN WEAKEN INTO AN OPEN WAVE AND SHIFT
EAST. THE MOST SIGNIFICANT BAND OF PCPN SHOULD ALREADY HAVE MOVED
THROUGH THE CWA (MONDAY AFTERNOON THROUGH TUESDAY)...BUT A HIGH
POP/LOW QPF SCENARIO IS LIKELY TO CONTINUE THROUGH THURSDAY.
MODELS ARE ALL OVER THE PLACE WITH REGARD TO THE VARIOUS S/W TROFS
ROTATING AROUND THE MAIN UPPER LOW...SO HAVE GONE WITH A MULTI-
MODEL BLEND...RESULTING IN BROADBRUSH LIKELY POPS FROM TUES NGT
THROUGH THURSDAY. PCPN SHOULD BE ALMOST ALL RAIN...BUT KEPT A MIX
IN OVER VILAS CO LATE WED NGT/EARLY THU.
THE UPPER AIR PATTERN IS EXPECTED TO GRADUALLY TRANSITION TO
ZONAL FLOW BY THE END OF THE WEEKEND/EARLY NEXT WEEK...WITH OCNL
S/W TROFS AND WEAK COLD FRONTS MOVING THROUGH. SMALL POPS ARE
WARRANTED DURING THIS PERIOD...BUT PCPN AMOUNTS SHOULD BE ON THE
LIGHT SIDE. THE AIR MASS WILL REMAIN COOL ENOUGH FOR A LIGHT MIX
OF RAIN AND SNOW SHOWERS OVER NORTHERN WI DURING SOME OF THE
NIGHTTIME PERIODS.
TEMPERATURES WILL REMAIN BLO NORMAL THROUGH THE PERIOD...WITH
HIGHS MAINLY IN THE UPPER 40S TO MIDDLE 50S...AND LOWS IN THE
30S AND LOWER 40S.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1200 PM CDT MON APR 28 2014
A LARGE UPPER LOW SYSTEM SLOWLY CHURNING ACROSS MID
SECTION OF THE COUNTRY THIS WEEK WILL CONTINUE TO LIFT BANDS OF
SHOWERS NORTH OVER THE STATE FOR MUCH OF THE WEEK. DRY AIR ON
EASTERLY WINDS WILL CONTINUE TO POUR INTO THE AREA TO KEEP CIGS
MAINLY AT VFR LEVELS FOR THE REST OF THIS AFTERNOON. AS SHOWERS
BECOME MORE WIDESPREAD FROM SOUTHWEST TO NORTHEAST...CIGS WILL
ALSO LOWER TO MVFR OR IFR LEVELS. A COMPACT PRESSURE GRADIENT
AHEAD OF THE LARGE SURFACE LOW OVER THE CENTRAL PLAINS WILL ENSURE
GUSTY WINDS AT THE SURFACE FOR A FEW DAYS.
&&
.HYDROLOGY...
ISSUED AT 240 PM CDT MON APR 28 2014
RAINFALL TOTALS OF 1 TO 2 INCHES CAN BE EXPECTED BY WEDNESDAY
AFTERNOON. THE HIGHEST TOTALS WILL BE ACROSS PORTIONS OF CENTRAL
WISCONSIN INTO THE FOX VALLEY REGION. THE RESULTING RUNOFF COULD
CAUSE SOME MINOR RIVER FLOODING...AS SEVERAL RIVERS STILL REMAIN
ABOVE BANKFULL. WILL CONTINUE TO MENTION THE RIVER FLOODING
THREAT IN A HYDROLOGIC OUTLOOK AND THE HAZARDOUS WEATHER OUTLOOK.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......MPC
HYDROLOGY......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1110 PM CDT SUN APR 27 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 313 PM CDT SUN APR 27 2014
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED TROUGHING ALONG THE BRITISH COLUMBIA COAST...A POTENT
NEGATIVELY TILTED TROUGH AND UPPER LOW OVER KANSAS...AND A STRONG
UPPER LEVEL RIDGE FROM THE SOUTHEASTERN U.S. INTO MANITOBA. IN-
BETWEEN THE UPPER LOW AND RIDGE...PROFILER AND VWP DATA SHOWED A 30-
50 KT JET CORE AT 850MB FROM THE WESTERN GULF OF MEXICO NORTHWARD
THROUGH MINNESOTA RAPIDLY TRANSPORTING MOISTURE NORTHWARD. GOES
PRECIPITABLE WATER IMAGERY DEPICTED VALUES OF 1-1.5 INCHES
ENCOMPASSING MUCH OF IOWA SOUTHWARD INTO LOUISIANA...WITH LOWER
VALUES OF LESS THAN 0.5 INCH OVER MUCH OF KANSAS INTO WESTERN
OKLAHOMA WHERE A DRY SLOT EXISTS. ALONG AND JUST EAST/NORTHEAST OF
THIS GRADIENT OF PRECIPITABLE WATER...NUMEROUS SHOWERS AND
THUNDERSTORMS HAVE DEVELOPED FROM CENTRAL IOWA AND MISSOURI. SOME OF
THESE STORMS ARE INTENSE TOO...MOSTLY SOUTH OF I-80 WHERE 750-1500
J/KG OF MLCAPE EXISTS PER RAP ANALYSIS. FARTHER NORTHEAST... SHOWERS
AND EMBEDDED THUNDERSTORMS THAT AFFECTED THE FORECAST AREA THIS
MORNING HAVE MOSTLY LIFTED NORTH OF I-90. THESE ARE ASSOCIATED WITH
MID-LEVEL FRONTOGENESIS AND RIGHT ENTRANCE REGION OF AN UPPER JET
OVER LAKE SUPERIOR. LASTLY...A TIGHT PRESSURE GRADIENT IN PLACE
COMBINED WITH THAT AFOREMENTIONED STRONG 850MB JET CORE HAS LED TO
BRISK EAST WINDS. THESE HAVE BEEN SUSTAINED AT 15-35 MPH WITH GUSTS
OF 25-45 MPH...STRONGEST WEST OF THE MS RIVER.
VERY GOOD MODEL AGREEMENT CONTINUES THAT THE BAND OF SHOWERS AND
THUNDERSTORMS TO OUR SOUTHWEST WILL LIFT NORTHEAST THROUGH THE
FORECAST AREA TONIGHT INTO MONDAY MORNING. THIS IS ALL IN RESPONSE
TOO THE UPPER LOW AND ASSOCIATED SHORTWAVE TROUGH LIFTING INTO
NEBRASKA AND IOWA BY 18Z MONDAY. THE QUESTION IS AMOUNT WHICH HAS
BIG IMPACTS ON POTENTIAL FOR RIVER FLOODING. THE AMOUNT HAS STRONG
TIES TO EVOLUTION OF CONVECTION OVER WESTERN MISSOURI AND SOUTHWEST
IOWA IN WHICH THERE ARE THREE SCENARIOS...
1. THE CONVECTION TURNS INTO A FORWARD PROPAGATING SQUALL
LINE...ESSENTIALLY LIMITING HEAVIER RAINFALL INTO THE FORECAST AREA.
THIS SQUALL LINE FALLS APART OVER ILLINOIS LATE THIS EVENING AS IT
RUNS INTO MORE STABLE AIR.
2. THE CONVECTION WEAKENS AS IT PUSHES EAST...RESULTING IN A
PERSISTENT WARM CONVEYOR BELT OF SHOWERS AND EMBEDDED THUNDERSTORMS.
THE TRAINING FACTOR COMES INTO PLAY...ALLOWING FOR HEAVIER
RAINFALL...ESPECIALLY ACROSS NORTHEAST IOWA THIS EVENING.
3. THE CONVECTION WEAKENS AS IT PUSHES EAST...AND ESSENTIALLY MUCH
OF THE SHOWER ACTIVITY FALLS APART BY 04Z.
ALL THREE IDEAS ARE CERTAINLY PLAUSIBLE...BUT IT IS SERIOUSLY WORTH
NOTING THE CONVECTION HAS BEEN OUTRUNNING MOST MODELS. THE ONLY
MODEL THAT HAS BEEN HANDLING THIS WELL IS THE 00Z SPC WRF-NMM...
WHICH IS SCENARIO NUMBER 3 ABOVE. THEREFORE...HAVE TRIED TO LEAN
MORE TOWARDS THAT FOR PRECIPITATION CHANCES AND QPF. STILL...THE
FORECAST MAY BE OVERDONE...ESPECIALLY WITH PRECIPITATION CHANCES IN
THAT 04-09Z TIME FRAME. WOULD THINK THAT PERSISTENT 850MB MOISTURE
TRANSPORT WOULD AT LEAST CONTINUE SOME SHOWER ACTIVITY AND NOT
COMPLETELY END...THUS THE HIGHER CHANCES IN THE FORECAST. ALL THREE
SCENARIOS ABOVE REGENERATE SHOWERS AND EMBEDDED THUNDERSTORM
ACTIVITY OVER THE FORECAST AREA AROUND 09Z...ASSOCIATED WITH DPVA
FROM THE APPROACHING NEGATIVELY TILTED SHORTWAVE TROUGH. SEE
HYDROLOGY SECTION BELOW FOR IMPACT ON RIVERS.
AFTER THE RAIN AND CONVECTION TONIGHT/MONDAY MORNING...ATTENTION
THEN TURNS TO A WARM FRONT PROGGED TO LIFT THROUGH IOWA. THE
MAJORITY OF MODELS KEEP IT JUST SOUTH OF THE FORECAST AREA...EITHER
ALONG OR SOUTH OF US-20. THE NORTHWARD PROGRESS OF THE FRONT HINGES
QUITE A BIT ON MORNING PRECIPITATION. CONVECTION LOOKS LIKELY TO
FIRE ALONG AND SOUTH OF THIS FRONTAL BOUNDARY. SOME OF THIS
CONVECTION COULD CREEP INTO FAR SOUTHERN PORTIONS OF THE FORECAST
AREA IN THE LATE AFTERNOON...AND POSSIBLY BE SEVERE. NOTE THAT A
VERY TIGHT GRADIENT OF INSTABILITY WILL EXIST...SO ANY SEVERE THREAT
SHOULD BE CONFINED TO FAYETTE EAST TO GRANT COUNTIES.
LASTLY...REGARDING THE WIND ADVISORY...AS EXPECTED THE CONDITIONS
HAVE BEEN MARGINAL. WILL KEEP IT GOING THROUGH 9 PM AS SUSTAINED
SPEEDS CONTINUE TO PULSE UP AND DOWN TO 30 MPH. THERE IS A
POSSIBILITY THE ADVISORY MAY NEED TO BE EXTENDED TO MIDNIGHT SEEING
SOME LAV GUIDANCE HOLDING RST...TOB AND OLZ BETWEEN 25-30 KT TO
06Z.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 313 PM CDT SUN APR 27 2014
THE UPPER LOW OVER NEBRASKA ON MONDAY IS THE MAIN FEATURE OF FOCUS
FOR THE LONG TERM PERIOD. MODELS CONTINUE TO SUGGEST THIS UPPER LOW
WILL PLAGUE THE FORECAST AREA THROUGH AT LEAST THURSDAY AS IT SLOWLY
TRACKS NORTHEAST INTO UPPER MICHIGAN. HEADING INTO THE WEEKEND...THE
UPPER PATTERN REMAINS COOL AS RIDGING HOLDS IN PLACE OVER THE
WESTERN U.S. INTO WESTERN CANADA...CAUSING TROUGHING TO PERSIST OVER
THE GREAT LAKES REGION. THIS IS VERY WELL AGREED UPON BY THE
27.06Z/12Z GFS AND 27.00Z/12Z ECMWF.
FOR MONDAY NIGHT INTO TUESDAY. CONDITIONS REMAIN FAVORABLE FOR A
BAND OF SHOWERS TO FORM JUST NORTH OF THAT WARM FRONTAL BOUNDARY IN
IOWA MONDAY EVENING...ASSOCIATED WITH DPVA FORCING AND 800-900MB
FRONTOGENESIS. THIS BAND...AFFECTING LOCATIONS SOUTH OF I-90 MONDAY
EVENING...SHOULD TRANSLATE NORTHWARD TO ALONG AND NORTH OF I-90 BY
TUESDAY MORNING...WITH PRECIPITATION POSSIBLY TAILING OFF TO THE
SOUTH. THEN WE GET INTO A COLD CONVEYOR BELT SCENARIO FOR TUESDAY
AFTERNOON OVER NORTHWESTERN SECTIONS OF THE FORECAST AREA. OTHER
SHOWERS SHOULD POP UP ELSEWHERE UNDER THE UPPER LOW DUE TO MID LEVEL
COLD AIR. THERE COULD EVEN BE SOME THUNDER WITH THEM...BUT
CONFIDENCE TOO LOW TO INCLUDE RIGHT NOW.
FROM TUESDAY NIGHT THROUGH THURSDAY...THE FORECAST AREA PRETTY MUCH
SITS IN A GRADUALLY WEAKENING COLD CONVEYOR BELT OF SHOWERS...WITH
PERHAPS SOME DIURNAL ENHANCEMENT THAT COULD INCREASE COVERAGE.
GIVEN HIGH CONFIDENCE OF PRECIPITATION AROUND...HAVE USED COVERAGE
VERBIAGE. WITH PLENTY OF CLOUDS AND SHOWER ACTIVITY AROUND...
COMBINED WITH 850MB TEMPS ONLY AROUND 0C PLUS OR MINUS 2
C...EXPECT CHILLY TEMPERATURES.
CHANCES OF PRECIPITATION CONTINUE OFF AND ON FOR THURSDAY NIGHT
RIGHT THROUGH SUNDAY AS SHORTWAVES DROP SOUTHEAST THROUGH THE GREAT
LAKES TROUGHING. SOME SIGNAL THAT A SHORTWAVE TROUGH ON SUNDAY
MIGHT BE MORE POTENT...SO CHANCES MAY NEED TO BE RAISED BEYOND THE
CURRENT FORECAST OF A MODEL CONSENSUS. AS IT STANDS RIGHT NOW THE
AIR IS NOT COLD ENOUGH FOR SNOW...BUT ITS NOT FAR OFF. 850MB
STANDARDIZED ANOMALIES GENERALLY HOLD AROUND 1 STANDARD DEVIATION
BELOW NORMAL...OR BETWEEN -4C AND 0C. NEEDLESS TO SAY...BELOW
NORMAL TEMPERATURES CONTINUE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1110 PM CDT SUN APR 27 2014
CHALLENGING FORECAST AS THERE WILL BE PERIODS OF RA/TSRA...AND PIN
POINTING WHERE THE BREAKS IN THE PCPN WILL BE IS PROBLEMATIC. IN
ADDITION...WINDS WILL STAY STRONG AND GUSTY THROUGH TUESDAY AS TIGHT
PRESSURE GRADIENT PERSISTS FOR MUCH OF THE UPPER MISSISSIPPI RIVER
VALLEY - WITH THE RESPONSIBLE SFC LOW JUST TO THE SOUTH. WINDS WILL
ALSO REMAIN STRONG JUST OFF THE SFC...50-60 KTS AROUND 2 KFT. LLWS
WILL BE A FACTOR FOR KLSE THRU MONDAY AFTERNOON.
BRIEF BREAK IN -SHRA FOR KRST/KLSE AS ONE BAND OF PCPN SHIFTED NORTH
EARLIER THIS EVENING. ANOTHER BATCH OF SHRA/TS IS DEVELOPING ON THE
NOSE OF AN INCREASING LOW LEVEL JET ACROSS CENTRAL/EASTERN IA. A
MORE SIGNIFICANT SWATH OF THE WIDESPREAD SHRA/TS WILL RETURN NEAR
12Z MON AS AN UPPER LEVEL SHORTWAVE TROUGH SPINS NORTHEAST OUT OF
THE SOUTHERN PLAINS. SHOULD MAKE FOR A SOGGY MORNING WITH MVFR
VSBYS. ANTICIPATING CIGS IN THE IFR/MVFR RANGE BY THIS TIME.
MODEL TRENDS WOULD FAVOR LIFTING THIS NORTH OF THE TAF SITES BY 18-
20Z...BRINGING ANOTHER MOSTLY DRY PERIOD FOR THE AFTERNOON.
HOWEVER...ANOTHER ROUND OF PCPN APPEARS LIKELY AS SHRA/TS FIRE UP
ALONG A WARM FRONT JUST TO THE SOUTH LATE AFTERNOON/EVENING...WHICH
COULD PUSH NORTH.
BOTTOM-LINE...AN EXTENDED PERIOD OF WET WEATHER WITH IFR/MVFR
IMPLICATIONS FOR CIGS AND VSBYS. SOME THUNDER WILL BE POSSIBLE.
WINDS ARE GOING TO STAY STRONG...MOSTLY EAST-NORTHEAST...AND LLWS
WILL REMAIN A CONCERN AT KLSE INTO MON AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 313 PM CDT SUN APR 27 2014
PRECIPITATION FORECASTS REMAIN VERY UNCERTAIN FOR TONIGHT AS
SHOWERS AND EMBEDDED THUNDERSTORMS OVER CENTRAL IOWA ARE MOVING
FASTER THAN MOST MODELS. IN FACT...THE ONE MODEL THAT IS HANDLING
THE PRECIPITATION WELL SUGGESTS WE COULD HAVE A BREAK OF 6 HOURS
OF NO PRECIPITATION TONIGHT AFTER THEY PASS. ADDITIONALLY...THE
CONVECTION TO THE SOUTH MAY END UP INGESTING MORE OF THE
MOISTURE...LIMITING HEAVIER RAINFALL OVER THE FORECAST AREA. THIS
SCENARIO IS LOOKING MORE LIKELY FOR TONIGHT. BETTER CONFIDENCE
FOR MUCH OF THE AREA TO SEE ANYWHERE FROM 1/4 TO 1 INCH OF RAIN ON
MONDAY...WITH ANOTHER 1/2 TO 1 INCH FROM MONDAY NIGHT INTO
TUESDAY.
IN SUMMARY...BASED ON RFC FORECAST DATA...CONFIDENCE WAS ONLY HIGH
ENOUGH TO PUT A FLOOD WATCH ON THE TURKEY RIVER. SHOULD AROUND 1
INCH MATERIALIZE OVER THE BASIN THIS EVENING...THE WATCH WILL NEED
TO BE UPGRADED. ELSEWHERE...HAVE CONTINUED THE ESF. THERE ARE SOME
SIGNALS THAT HEAVIER QPF COULD FALL OVER WISCONSIN. SHOULD THIS
MATERIALIZE...MORE FLOOD WATCHES FOR AREA RIVERS MAY BE REQUIRED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR MNZ086-087-094-095.
IA...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR IAZ008>010-018-019-
029.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
HYDROLOGY....AJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
502 PM MDT MON APR 28 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 247 PM MDT MON APR 28 2014
MAIN CONCERN THIS PERIOD WILL CONTINUE TO BE WINDS AS THEY WILL
REMAIN RATHER STRONG THOUGH WEDNESDAY...ESPECIALLY OVER THE
PLAINS. IN THE IMMEDIATE SHORT-TERM CURRENT ADVY/HI WIND HILITES
LOOK FINE OVER MOST OF THE PANHANDLE AND WILL KEEP UP INTO THIS
EVENING...HOWEVER WILL TRIM OUT DAWES AND BOX BUTTE COUNTIES AS
WINDS HAVE DROPPED OFF THERE.
UPPER LOW OVER NEB WILL DRIFT ONLY SLOWLY EASTWARD OR MEANDER
THROUGH WEDS WITH STRONG MID-LEVEL WINDS MIXING DOWN TO THE
SURFACE BOTH AFTERNOONS. BIG DILEMMA IS HOW MUCH. CLOUDS AND PCPN
WILL TEND TO LIMIT MIXING SOME. PROGGED 800MB WINDS FOR TUESDAY
ABOUT THE SAME AS TODAY WHERE MOST AREAS STAYED IN ADVISORY SPEEDS.
WILL NEED AT LEAST AN ADVISORY FOR THE PANHANDLE AGAIN TUESDAY AND
COULD FLIRT WITH HIGH WIND LEVELS DESPITE SLIGHTLY LESS GRADIENT
IF MORE MIXING OCCURS. WILL HOLD OFF ON NEW HILITES FOR NOW...
ALLOWING CURRENT ONES TO EXPIRE FIRST.
WRAP-AROUND PRECIPITATION WILL ALSO CONTINUE TONIGHT AND TUESDAY
THEN SHOULD TREND DOWN TUESDAY NIGHT AND WEDS AS THE UPPER LOW
DRIFTS FARTHER AWAY AND A SOMEWHAT DRIER NORTHERLY FLOW OCCURS
OVER THE AREA. SOME LIGHT SNOW ACCUMULATIONS POSSIBLE OVER THE
NORTHERN PANHANDLE TONIGHT THOUGH HIGHER AMOUNTS LOOK TO BE JUST A
BIT TO THE EAST. TEMPERATURES REMAINING COOL THROUGH WEDNESDAY.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 247 PM MDT MON APR 28 2014
LATEST WATER VAPOR LOOP WAS SHOWING THE UPPER LEVEL RIDGE BUILDING
ACROSS THE PACIFIC NORTHWEST IN RESPONSE TO THE DIGGING UPPER
LEVEL TROF OFF THE GULF OF ALASKA. THIS SCENARIO WILL FAVOR RATHER
DRY AND COOL CONDITIONS ON THURSDAY. BEYOND THURSDAY...THE UPPER
LEVEL PATTERN BEGINS TO FLATTEN OUT SOME WHICH WILL FAVOR MORE UNSETTLED
CONDITIONS TOWARDS THE WEEKEND.
FRIDAY-SATURDAY:
THE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH A WARM UP TAKING PLACE
THIS WEEKEND AS 700MB TEMPERATURE STANDARDIZED ANOMALIES APPROACH
TO 1 STANDARD DEVIATION. THIS SHOULD ALLOW FOR TEMPERATURES TO
CLIMB TO AROUND 70 ON SATURDAY. IT MAY BE A TAD COOLER ACROSS
NORTHEAST CORNER OF OUR FORECAST AREA CLOSER TO THE UPPER LEVEL
TROF PUSHING DOWN INTO THE NORTHERN PLAINS. A WEAK BOUNDARY IS
EXPECTED TO DIVE SOUTHEAST ACROSS THE AREA ON FRIDAY AND MAY BRING
A CHANCE OF SHOWERS MAINLY ACROSS AREAS EAST OF THE LARAMIE RANGE
FRIDAY MORNING. ELSEWHERE...THERE WILL BE SOME GOOD UPSLOPE
FLOW IN THE HIGHER ELEVATIONS WHICH WILL FAVOR SOME SCATTERED RAIN
SHOWERS ON FRIDAY. SATURDAY WE MAY SEE MORE OF A THREAT OF SOME
SHOWERS AND THUNDERSTORMS DEVELOPING ALONG A BOUNDARY EXTENDING
FROM THE SOUTHERN PANHANDLE TO DOUGLAS. THIS AREA MAY ACTUALLY SEE
A FEW THUNDERSTORMS DURING THE AFTERNOON WITH CAPE VALUES REACHING
1000J/KG. WE WILL SEE HOW THINGS EVOLVE AS WE APPROACH THE WEEKEND
ESPECIALLY WITH REGARDS TO THE POSITION OF THE WAVES.
SUNDAY-MONDAY:
THE MODELS DO SHOW SOME WEAK UPPER LEVEL RIDGING TAKING PLACE
WHICH WILL KEEP OUR TEMPERATURES ON THE MILD SIDE. THE SURFACE LEE
TROF MAY ALSO BECOME ESTABLISHED WHICH MAY FAVOR BETTER MOISTURE
EAST OF THE LARAMIE RANGE. AS A RESULT...WE MAY SEE A CHANCE OF
THUNDERSTORMS EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY AFTERNOON)
ISSUED AT 458 PM MDT MON APR 28 2014
STRATUS LIKELY TO MOVE INTO THE KCDR AND KAIA AERODROMES THIS
EVENING AND PERSIST INTO TUESDAY MORNING. LATEST HRRR FORECAST
DOES SHOW SOME TEMPO IFR CONDITIONS UP THAT WAY FOR A TIME
TONIGHT. BIG ISSUE IS WIND...WHICH WILL DIE OFF SLIGHTLY
TONIGHT...BUT THEN PICK UP AROUND THE 14Z TIME FRAME TUESDAY. WIND
GUSTS OR 45 TO 50KTS LIKELY FOR THE SOUTHERN PANHANDLE AIRPORTS
ONCE AGAIN TUESDAY.
&&
.FIRE WEATHER...
ISSUED AT 247 PM MDT MON APR 28 2014
NO CONCERNS ANTICIPATED THROUGH THE WEEK WITH TEMPERATURES
EXPECTED TO BE COOL TO MILD THROUGH THE MID PART OF THE WEEK THEN
WARM SOME BY THE END OF THE WEEK. CONDITIONS WILL REMAIN NON-
CRITICAL OUTSIDE OF WINDS WHICH WILL REMAIN RATHER STRONG MAINLY
IN THE AFTERNOONS OVER THE PLAINS THROUGH WEDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR NEZ095-096.
HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING FOR NEZ019>021-054-
055.
&&
$$
SHORT TERM...RE
LONG TERM...REC
AVIATION...CLAYCOMB
FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS TAUNTON MA
317 AM EDT WED APR 30 2014
.SYNOPSIS...
HIGH PRESSURE OVER QUEBEC BUILDS INTO THE GULF OF MAINE TODAY
PROVIDING UNSEASONABLY COOL TEMPERATURES ACROSS SOUTHERN NEW
ENGLAND. LOW PRESSURE APPROACHING FROM THE WEST WILL RESULT IN
RAIN BECOMING MORE WIDESPREAD ACROSS THE REGION TODAY...THEN
HEAVY AT TIMES TONIGHT INTO EARLY THU. DRIER AND MILD WEATHER
OVERSPREADS THE AREA FRI. FOR THE WEEKEND...OTHER THAN ISOLATED
TO WIDELY SCATTERED AFTERNOON SHOWERS MAINLY DRY WEATHER WILL
PREVAIL ALONG WITH SEASONABLE TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SIGNIFICANT CHANGES MADE TO THE NEAR-TERM FORECAST. ISENTROPIC
FORCING AROUND H7 BENEATH INCREASING DIFFLUENCE ALOFT ALLOWING FOR
WIDESPREAD RAIN ACROSS THE REGION. AMOUNTS WILL BE LIGHT THOUGH
THE HEAVIEST WILL BE ACROSS THE CT-RIVER VALLEY. COULD SEE A WET
SNOWFLAKE OR SLEET ACROSS THE HIGHER ELEVATIONS WITH H925 TEMPS A
DEGREE OR TWO BELOW FREEZING PER SPC MESOANALYSIS. COMPLICATIONS
TO THE EAST AS MOISTURE RUNS UP AGAINST MUCH DRIER AIR /SEE THE 0Z
SOUNDING OUT OF CHATHAM...IMPRESSIVELY DRY BETWEEN H9-H5!/.
NONE OF THE NEAR-TERM FORECAST GUIDANCE DOING WELL IN HANDLING THE
SITUATION. NEITHER THE RAP NOR HRRR HAVE PRECIP PROGRESSING SO FAR
TO THE EAST. HAVE HAD TO IMPROVISE ACCORDINGLY. PUSHED POPS TO
HIGH CATEGORICAL WHILE INCREASING THE PRECIPITATION AND THAT WILL
CONTINUE THROUGH THE MORNING FOR MUCH OF THE CENTRAL AND WESTERN
PORTIONS OF THE FORECAST AREA /MAINLY WEST OF WORCESTER MA/.
FILLING IN SOMEWHAT TO THE SOUTH AND WEST. PLUME OF PWATS PUSHING
NORTH ADVECTED ACROSS THE REGION WITH THE H85-6 MOIST TRANSPORT.
PERHAPS THE RAIN WILL TAPER OFF BRIEFLY...BUT EXPECT A RETURN
PUNCH OF MOISTURE INTO WEDNESDAY. MUCH OF THE IMPROVISED OUTCOMES
MATCH UP QUITE WELL WITH THE 29.18Z GEFS MEANS.
BUSTED ON THE MAX TEMPS TODAY AND THUS LEANING WITH COLDER
OUTCOMES FOR TONIGHT. THAT EASTERLY ONSHORE FLOW OFF THE OCEAN
WATERS RANGING AROUND THE LOW-40S IS REALLY PUTTING A DENT IN THE
START OF SPRING. SHOULD BE A CHILLY DISMAL NIGHT WITH LOWS DOWN
AROUND THE MID-30S FOR MUCH OF THE REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
WEDNESDAY...
AS THE SLOWLY MOVING HIGH PRES RIDGE PUSHES OFFSHORE...EXPECT
WINDS TO SHIFT AROUND TO E-SE DURING THE DAY. NEXT SURGE OF LOW
LEVEL MOISTURE CONVERGENCE WORKS INTO CENTRAL AND WESTERN AREAS
DURING THE LATE MORNING AND AFTERNOON. ONSHORE WINDS WILL HELP
FEEL MORE LOW LEVEL MOISTURE INTO THIS LIFT AS WELL AS INCREASE
H925 SOUTHERLY JET. E-SE WINDS WILL PICK UP ESPECIALLY ALONG THE
COAST AS PRESSURE GRADIENT TIGHTENS UP. STILL UNDER THE COOLER
MARITIME INFLUENCE...SO INSTABILITY WILL STAY OFFSHORE FOR NOW.
EXPECT HIGHS TO RANGE FROM THE MID-UPPER 40S WELL INLAND TO THE
LOWER 50S ACROSS S COASTAL AREAS.
WEDNESDAY NIGHT...
A WARM FRONT WILL BEGIN TO APPROACH FROM THE SW. ANOTHER SHORT OF
ENERGY WILL DEVELOP ALONG THIS FRONT WITH A POSSIBLE TRIPLE POINT/
WAVE OF LOW PRES APPROACHING OVERNIGHT. ALSO NOTING INCREASING
INSTABILITY AS TT/S INCREASE TO AROUND 50...K INDICES INTO THE
LOWER 30S AND LIFTED INDICES LOWER TO ZERO TO -1. HAVE PUT IN
MENTION OF THUNDER MAINLY AROUND OR AFTER MIDNIGHT BEGINNING
ACROSS N CT/W MA THEN SHIFTING E.
NOTING ANOTHER SHOT OF GOOD QPF MOVING IN DURING THIS TIMEFRAME
AS S WINDS INCREASE. THIS WILL BRING MOISTURE RICH AIR TOWARD THE
REGION AS PWATS INCREASE TO AROUND 1.5 INCHES...WHICH IS +2 SD
ABOVE SEASONAL NORMALS. FORECASTED QPF ON ORDER OF 0.7 TO 1.5
INCHES DURING THIS TIMEFRAME...HIGHEST ACROSS N CT INTO SW MA AND
W RI. THIS...ALONG WITH ANY CONVECTION POSSIBLY PRODUCING LOCALLY
HIGHER AMOUNTS OF RAINFALL...COULD CAUSE RISING RIVERS. WITH THIS
IN MIND...HAVE PUT UP A FLOOD WATCH FOR THOSE AREAS WHERE BEST
SHOT FOR CONVECTION AND HEAVIER RAINFALL. LEFT OUT SE RI AND SE MA
FOR NOW...AS IT APPEARS BEST CHANCE FOR HEAVIER RAINFALL WILL HOLD
OFF UNTIL THURSDAY.
EXPECT LOW TEMPS TO OCCUR EARLY AS WINDS SHIFT AROUND TO S-SE
OVERNIGHT. READINGS WILL BOTTOM OUT IN THE 40S BY AROUND
MIDNIGHT...THEN SHOULD REMAIN STEADY OR SLOWLY RISE...ESPECIALLY
ACROSS SOUTHERN AREAS AFTER MIDNIGHT AS THE WARM FRONT APPROACHES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* MILDER TEMPS FRI AND SAT THEN COOLING SLIGHTLY SUN/MON
* ISOLATED/SCATTERED DIURNAL SHOWERS EACH DAY...OTHERWISE MAINLY DRY
HIGH AMPLITUDE REX BLOCK IN THE NEAR/SHORT TERM DEAMPLIFIES AS TIME
PROGRESSES THIS WEEKEND AND INTO EARLY NEXT WEEK. THUS UPPER AIR
PATTERN BECOMES MORE ZONAL OFFERING LESS UNSETTLED WEATHER AND TEMPS
MORE SEASONABLY MILD FOR EARLY MAY! AT THE SURFACE...OCCLUDED FRONT
MOVES OFFSHORE THU NIGHT WITH THE PARENT LOW REMAINING OVER
SOUTHEAST CANADA FRI/SAT...PROVIDING DRY/MILD WESTERLY FLOW INTO
SOUTHERN NEW ENGLAND. BY SUN/MON NEW AND ROBUST NORTHERN STREAM JET
ENERGY DIVES ACROSS THE GREAT LAKES AND INTO NEW ENGLAND...PROVIDING
SLIGHTLY COOLER TEMPS AND THE RISK OF DIURNAL ISOLATED/SCATTERED
SHOWERS.
DAILY SENSIBLE WEATHER DETAILS...
FRI/SAT...MILD WITH HIGHS WELL INTO 60S INCLUDING THE COASTLINE AS
MODEST WESTERLY PGRAD PRECLUDES ANY SEABREEZE. COOLER SAT ALONG
SOUTH COAST AS WINDS BECOME SSW. STILL MILD INLAND WITH HIGHS IN THE
60S ONCE AGAIN. MAINLY DRY WEATHER BUT STILL A LOW RISK OF A FEW
DIURNAL SHOWERS INLAND ESPECIALLY SAT GIVEN THE WEAK CYCLONIC FLOW
ALOFT AND MODEST MID LEVEL LAPSE RATES.
SUNDAY/MONDAY...NORTHERN STREAM GETS REINVIGORATED AS A STRONG SHORT
WAVE TROUGH DIVES SOUTHEAST FROM WEST-CENTRAL CANADA INTO THE GREAT
LAKES SAT. THIS TROUGH AND ITS ATTENDING COOL POCKET OF AIR ALOFT
/700 MB TEMPS -1 STD FROM CLIMO/ WILL MOVE ACROSS NEW ENGLAND SUN
AND MON. STEEPENING MID LEVEL LAPSE RATES COMBINED WITH CYCLONIC
FLOW ALOFT WILL RESULT IN THE RISK OF SCATTERED DIURNAL SHOWERS EACH
DAY. BY NO MEANS A WASHOUT BUT SHOWERS WILL BE MOST NUMEROUS DURING
THE AFTERNOON AND EARLY EVENING HOURS. OTHERWISE SLIGHTLY COOLER
THAN FRI/SAT WITH HIGHS SUN IN THE L60S AND COOLING OFF INTO THE
U50S MON...WITH U30S AND L40S MON MORNING.
TUESDAY AND BEYOND...FURTHER PATTERN MODIFICATION HERE WITH ZONAL
FLOW TRENDING TOWARD A WESTERN US TROUGH AND A DEVELOPING DOWNSTREAM
RIDGE OVER THE EAST. THIS WOULD SUGGEST MILDER TEMPS AND A TREND
TOWARD DRIER WEATHER. THIS IS SUPPORTED BY TELECONNECTIONS WITH
NEGATIVE AO AND NAO TRENDING NEUTRAL ALONG WITH A POSITIVE PNA
TRENDING NEUTRAL AS WELL.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH WEDNESDAY NIGHT/...MODERATE CONFIDENCE WITH
TRENDS BUT LOWER CONFIDENCE CONCERNING SPECIFIC TIMING OF IMPACTS.
TONIGHT...MVFR CIGS MOST AREAS IN LOW LEVEL EAST FLOW. VSBYS
MAINLY VFR...BUT MAY SEE LOCAL MVFR AFTER MIDNIGHT ACROSS CT
VALLEY INTO CENTRAL MA/S NH AS -RA MOVES E. E WIND GUSTS UP TO 25
KT ALONG S COAST.
WEDNESDAY...MAINLY MVFR CIGS/VFR VSBYS TO START...THEN
DETERIORATING TO IFR DURING THE AFTERNOON FROM W-E AS HEAVIER
RAIN MOVES IN. PATCHY FOG DEVELOPING ACROSS S COASTAL AREAS. E
WIND GUSTS UP TO 25 KT ACROSS S COASTAL AREAS.
WEDNESDAY NIGHT...CONDITIONS LOWERING TO GENERAL IFR WITH POCKETS
OF LIFR IN LOCALLY HEAVY RAINFALL MAINLY ACROSS N CT/SW MA INTO W
RI AS NIGHT PROGRESSES. CHANCE FOR TSTMS ACROSS N CT/RI MAINLY
AFTER MIDNIGHT. SE WINDS GUSTING TO 25 KT MAINLY ALONG THE COAST.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...MODERATE CONFIDENCE.
THU NIGHT...ANY LEFTOVER EARLY EVENING SHOWERS IN THE EAST WILL MOVE
RAPIDLY OFFSHORE. MVFR EARLY SHOULD BE REPLACED BY VFR SECOND HALF
OF THE NIGHT.
FRIDAY AND SATURDAY...VFR WITH A LOW RISK OF A FEW AFTERNOON/EVENING
SHOWERS INLAND. WEST WINDS GUSTING TO 20 KNOTS FRIDAY. MAINLY VFR
SATURDAY WITH LIGHTER SOUTHWEST WINDS.
SUNDAY...VFR TO START WITH INCREASING CHANCE OF MVFR CIGS/VSBYS IN
SCATTERED DIURNAL SHOWERS.
&&
.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.
TONIGHT...E-NE WINDS WILL DIMINISH SOMEWHAT...BUT WILL STILL GUST
UP TO 20 KT. WILL SEE GUSTS UP TO 25-30 KT ON THE SOUTHERN OUTER
WATERS. E SWELLS UP TO 10 FT WILL CONTINUE ACROSS THE EASTERN
WATERS. SMALL CRAFTS CONTINUE FOR ALL OPEN WATERS. HAVE
DISCONTINUED SMALL CRAFT FOR BOSTON HARBOR AS WINDS/SEAS WILL
REMAIN BELOW CRITERIA.
WEDNESDAY-WEDNESDAY NIGHT...E WINDS GUSTING TO 25-30 KT OVER MOST
OPEN WATERS WILL SHIFT TO SE WED NIGHT. HIGHEST GUSTS OVER THE
OUTER WATERS WED NIGHT. SEAS REMAIN AOA 5 FT OVER THE OPEN WATERS.
HAVE PUT SMALL CRAFT UP FOR NARRAGANSETT BAY FOR LATE WED-WED
NIGHT.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...MODERATE CONFIDENCE.
THU NIGHT/FRI...IMPROVING WEATHER WITH FRONTAL PASSAGE MOVING
OFFSHORE. MODEST WEST WINDS BEHIND THE FRONT BUT DRY WEATHER ALONG
WITH GOOD VSBY. ROUGH SEAS GIVEN LEFTOVER SOUTHERLY SWELLS
COMBINING WITH INCREASING WEST WIND WAVES.
SAT/SUN...WIND MORE WSW SAT AHEAD LOW PRES MOVING INTO ST LWRNC RVR
VLY. WINDS THEN BECOME WNW SUN AS LOW STRENGTHENS AS IT TRACKS INTO
THE MARITIMES. GOOD VSBY OTHER THAN LOWERING AT TIMES IN DIURNAL
SCATTERED SHOWERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY AFTERNOON FOR
CTZ002>004.
MA...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY AFTERNOON FOR
MAZ009-011.
NH...NONE.
RI...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY AFTERNOON FOR
RIZ001>004-006.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ231>235-
237-250-251-254>256.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EDT
THURSDAY FOR ANZ236.
&&
$$
SYNOPSIS...NOCERA/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...NOCERA
AVIATION...NOCERA/SIPPRELL
MARINE...NOCERA/SIPPRELL
AREA FORECAST DISCUSSION
NWS NEW YORK NY
135 AM EDT WED APR 30 2014
.SYNOPSIS...
HIGH PRESSURE MOVES EAST AS A WARM FRONT APPROACHES FROM THE
SOUTHWEST THROUGH WEDNESDAY NIGHT. THE WARM FRONT MOVES NORTH OF
THE REGION ON THURSDAY. A WEAK COLD FRONT FOLLOWS THURSDAY NIGHT
FOLLOWED BY WEAK HIGH PRESSURE FRIDAY INTO THE WEEKEND. ANOTHER
COLD FRONT IS POSSIBLE LATE IN THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
FCST UPDATED TO INCLUDE NEW CSTL FLOOD ADVY FOR WED NGT. NO OTHER
CHANGES MADE.
DEEP LAYERED RIDGE AXIS CONTINUES TO SLOWLY SLIDE EAST OVERNIGHT.
AS IT DOES SO WILL SEE INCREASING ISENTROPIC FLOW AND DIVERGENCE
ALOFT FROM W TO E. STILL SHOULD GENERALLY BE CLOSE ENOUGH TO RIDGE
TO HAVE ENOUGH SUBSIDENCE TO KEEP RAIN SPOTTY - SO HAVE CONTINUED
WITH PERIODIC RAIN WORDING FOR OVERNIGHT.
A PERSISTENT EASTERLY FLOW WILL CONTINUE THROUGH THE NIGHT. THIS
FLOW WILL KEEP CONDITIONS COOL. USED A BLEND OF MAV/MET GUIDANCE
WITH NAM AND HRRR 2-METER TEMPERATURES FOR OVERNIGHT LOWS...WITH
TEMPERATURES AROUND 40 ACROSS THE NORTHERN INTERIOR AND LOWER 40S
ELSEWHERE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
A STRENGTHENING LOW LEVEL JET...ALONG WITH PERSISTENT EAST FLOW WILL
CONTINUE TO SATURATE THE COLUMN. A HIGHER AREA OF ISENTROPIC LIFT
WILL MOVE INTO THE REGION DURING THE SHORT TERM...RESULTING IN
A HIGHER COVERAGE OF RAIN.
THE POTENTIAL FOR MORE CONVECTIVE ACTIVITY IS EXPECTED WEDNESDAY
AFTERNOON DUE TO INCREASED LIFT...DEEPER MOISTURE AND CLOSER
PROXIMITY TO FRONT.
RAINFALL AMOUNTS BY WEDNESDAY EVENING WILL BE AT OR ABOVE AN INCH
ACROSS SOUTHWEST SECTIONS...TO UNDER AN INCH EAST.
METRO NJ/NYC SECTIONS COULD BE DEALING WITH URBAN FLOOD ISSUES LATE
IN THE DAY ON WEDNESDAY.
THE BEST FORCING MOVES OVER THE REGION WEDNESDAY NIGHT...BRINGING
THE BEST CHANCES FOR HEAVY RAIN AND POSSIBLY EVEN SOME THUNDER.
PRECIPITABLE WATERS INCREASE TO ABOUT 1.5 INCHES...SO WE COULD BE
LOOKING AT RAINFALL RATES AT OR NEAR ONE INCH PER HOUR. REFER TO
THE HYDROLOGY SECTION OF THE AFD FOR AMOUNTS AND IMPACTS.
AS FOR TEMPERATURES...WE SHOULD NOT SEE MUCH CHANGE IN TEMPERATURES
THROUGH THE SHORT TERM WITH EASTERLY FLOW...OVERCAST SKIES AND
RAINFALL. EXPECTED TEMPERATURES TO REMAIN IN THE 40S ON
WEDNESDAY...THEN COULD SEE TEMPERATURES RISE WEDNESDAY
NIGHT...DEPENDING ON EXACTLY WHEN THE WARM FRONT PUSHES N.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE UNSETTLED PATTERN WILL CONTINUE THROUGH THE LONG TERM PERIOD.
THE MODELS ARE IN PRETTY GOOD AGREEMENT CONCERNING THE PROGRESSION
OF THE CLOSED UPPER LOW OVER THE MIDWEST TO AN OPEN AND FLATTENING
WAVE THURSDAY AND FRIDAY. I/M NOT TOO COMFORTABLE WITH TOTALLY
BUYING INTO THIS AS THE MODELS TEND TO BE TOO QUICK WITH THIS
TRANSITION. EITHER WAY...WILL KEEP POPS IN THE FORECAST THROUGH
THURSDAY EVENING...AND WOULD NOT BE SURPRISED TO SEE PRECIPITATION
LINGER INTO FRIDAY FROM THIS SYSTEM. THEREAFTER...A BIT OF A TREND
TOWARD DRIER CONDITIONS AS FLOW FLATTENS OUT ALOFT. THERE WILL
STILL BE A WEAK MEAN TROUGH AXIS OVER THE MID WEST AND GREAT LAKES
WITH OCCASIONAL WEAK SHORT WAVES. WILL KEEP A MENTION OF
SHOWERS...MAINLY FOR AFTERNOON AND EARLY EVENING PERIODS FOR ANY
DIURNAL DRIVEN SHOWERS.
A STRONGER SHORTWAVE WILL SHARPEN THE TROUGH...AND POSSIBLY RESULT
IN ANOTHER CUTOFF OVER THE GREAT LAKES AND NORTHEAST BY SUNDAY.
THIS WILL PUSH A COLD FRONT ACROSS THE REGION LATE SUNDAY OR SUNDAY
NIGHT SPARKING OFF ANOTHER PERIOD OF SHOWERS AND POSSIBLY A
THUNDERSTORM. AGAIN THE MODELS ARE FAIRLY PROGRESSIVE WITH THIS
UPPER LEVEL LOW AND SHIFT THE POSITION OF THE LOW TO OUR NORTHEAST
BY MONDAY. THIS MAY TURN OUT TO BE QUICK AS WELL.
MODEL SOLUTIONS BEGIN TO DIVERGE FOR EARLY NEXT WEEK WITH THE ECMWF
REDEVELOPING A MEAN TROUGH / POTENTIAL CUTOFF WITH UPSTREAM ENERGY
WHILE THE GFS ADVERTISES ZONAL FLOW.
IF THE MODELS ARE CORRECT ABOUT THE PROGRESSION OF THE UPPER LOW
TRANSITIONING INTO AN OPEN WAVE...WE WILL HAVE A MILD START TO THE
LONG TERM PERIOD ON THURSDAY. THIS WILL BE THE WARMEST DAY OF THE
PERIOD...WITH A TREND TOWARD COOL AND GENERALLY DAMP CONDITIONS
THEREAFTER.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A WARM FRONT APPROACHES THE AREA FROM THE SOUTH TODAY.
CEILINGS ARE EXPECTED TO REMAIN MVFR AND COULD AT TIMES DROP TO IFR
EARLY THIS MORNING. LOWER CHANCE FOR IFR EASTERN TERMINALS INITIALLY.
BELIEVE ALL TERMINALS WILL OBSERVE IFR CEILINGS 12Z ONWARD.
AGAIN...IT MAY TAKE A FEW HOURS LONGER FOR EASTERN TERMINALS TO FALL
TO IFR. RAIN MAY BE MORE PERIODIC THROUGH THE DAY TODAY.
HOWEVER...RAIN IS INCLUDED IN THE TAFS PREVAILING.
VISIBILITIES WILL EVENTUALLY LOWER TO AROUND 1 NM...LIKELY AFTER 12Z
FROM WEST TO EAST.
BY EVENING...ISOLATED EMBEDDED THUNDERSTORMS REMAIN POSSIBLE.
HOWEVER...CONFIDENCE AND COVERAGE OF STORMS TOO LOW TO INCLUDE AT
ANY PARTICULAR TAF SITE THIS FAR OUT.
WINDS REMAIN EASTERLY. GUSTS 20 TO 25 KTS ARE MORE LIKELY THIS
MORNING. THEN STRENGTHENING INVERSION SHOULD LIMIT GUSTS.
HOWEVER...SUSTAINED WINDS OF 15 TO 20 KTS ARE ANTICIPATED THROUGH
MUCH OF THE PERIOD...ESPECIALLY COASTAL TERMINALS.
A SLIGHT SHIFT TO THE EAST/SOUTHEAST IS POSSIBLE THIS
EVENING...DEPENDING ON MOVEMENT OF THE WARM FRONT.
LLWS POSSIBLE AFTER SUNSET...ESPECIALLY FOR KTEB/KEWR/KSWF AND MAY
NEED TO BE ADDED TO TAFS IN FUTURE AMENDMENTS.
.OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY...
.LATE WED NGT...PERIODS OF IFR. TSTMS POSSIBLE. WINDS BECOMING SLY
AOA 20KT WITH LLWS POSSIBLE...BEFORE SWITCHING TO THE WW.
.THU...BECOMING VFR AFTER MORNING SHRA.
.FRI...VFR WITH W WINDS.
.SAT...MAINLY VFR.
.SUN...RA POSSIBLE WITH GUSTY W FLOW AROUND 15-20G25-30 DEVELOPING.
&&
.MARINE...
MADE MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK.
SMALL CRAFT ADVISORY REMAINS POSTED FOR ALL WATERS THROUGH WEDNESDAY
NIGHT. INCREASING EASTERLY WINDS...ALONG WITH BUILDING SEAS ARE
EXPECTED THROUGH WEDNESDAY NIGHT AS HIGH PRESSURE MOVES EAST AND A
WARM FRONT REMAINS NEAR OR SOUTH OF THE WATERS. WINDS WEDNESDAY
NIGHT WILL BECOME MORE SOUTHERLY...BUT GUSTY CONDITIONS AND ROUGH
SEAS WILL CONTINUE.
A ROBUST SOUTHWESTERLY FLOW ON THURSDAY WILL GRADUALLY SUBSIDE
FRIDAY INTO SATURDAY. SEAS WILL BE ROUGH ON THURSDAY...BUT WILL ALSO
FOLLOW THE SAME SLOW DOWNWARD TREND AS THE WINDS. A COLD FRONT WILL
APPROACH THE WATERS ON SUNDAY AND WILL RESULT IN STRENGTHENING WINDS
AND BUILDING SEAS SUNDAY NIGHT INTO MONDAY.
&&
.HYDROLOGY...
A SIGNIFICANT RAINFALL IS LIKELY WED THROUGH EARLY THU.
TOTAL BASIN AVG QPF SHOULD RANGE FROM 2.5 TO 3.5 INCHES...HIGHEST
NEAR NYC METRO AND NORTHEAST NJ. RAIN THROUGH WED AFTERNOON WILL
PRIME THE AREA FOR FLOODING PROBLEMS AS HEAVY RAIN MOVES IN FROM
LATE DAY WED INTO EARLY THU. NO CHANGES TO THE FLOOD WATCH WHICH
STARTS EARLIER FOR NYC METRO AND NE NJ WITH UP TO 1.5 INCHES OF RAIN
EXPECTED BY THAT TIME WHICH COULD IMPACT RUSH HOUR...THEN EXTENDED
TO THE REST OF THE AREA WED NIGHT INTO THU MORNING WITH ANOTHER PUSH
OF HEAVY RAIN. FLOODING OF SMALL STREAMS AND URBAN...LOW LYING AND
POOR DRAINAGE AREAS IS LIKELY.
&&
.TIDES/COASTAL FLOODING...
MINOR BENCH MARKS WERE REACHED AT ALL SOUTHERN GAUGES TNGT. LATEST
TRENDS INDICATE ON TRACK TO REACH MINOR BENCHMARKS ON WESTERN
SOUND EARLY OVERNIGHT.
TIDAL LEVELS WILL BE LOWER WITH THE WEDNESDAY MORNING INTO EARLY
AFTERNOON HIGH TIDES BUT WITH RESIDUAL SURGE...THERE COULD STILL BE
SOME ISOLATED MINOR COASTAL FLOODING POSSIBLE.
ANOTHER ROUND OF WIDESPREAD MINOR COASTAL FLOODING LIKELY WEDNESDAY
NIGHT. AS A RESULT HAVE ISSUED AN ADVY.
TIDAL LEVELS DROP FURTHER THURSDAY AND FLOW BECOMES MORE SOUTHWEST.
WHILE COASTAL FLOODING IS NOT EXPECTED AT THE MOMENT FOR THAT
TIME FRAME...THIS WILL STILL NEED TO BE WATCHED IN TRENDS FOR ANY
LOCATIONS THAT HAVE RESIDUAL WATER THAT CAN NOT DRAIN FULLY
OUT...ESPECIALLY ALONG THE CT COAST AND LONG ISLAND BACK BAYS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR
CTZ005>008-010>012.
FLOOD WATCH FROM THIS AFTERNOON THROUGH THURSDAY MORNING FOR
CTZ009.
COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO 2 AM EDT
THURSDAY FOR CTZ009-010.
COASTAL FLOOD ADVISORY UNTIL 2 AM EDT EARLY THIS MORNING FOR
CTZ009-010.
NY...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR
NYZ067-068-078>081.
FLOOD WATCH FROM THIS AFTERNOON THROUGH THURSDAY MORNING FOR
NYZ069>075-176>179.
COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO 2 AM EDT
THURSDAY FOR NYZ071>075-078-080-176>179.
COASTAL FLOOD ADVISORY UNTIL 2 AM EDT EARLY THIS MORNING FOR
NYZ071-073-078-176-177.
NJ...FLOOD WATCH FROM THIS AFTERNOON THROUGH THURSDAY MORNING FOR
NJZ002-004-006-103>108.
COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO 2 AM EDT
THURSDAY FOR NJZ006-106-108.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ330-335-
338-340-345-350-353-355.
&&
$$
SYNOPSIS...BC
NEAR TERM...JMC/MALOIT
SHORT TERM...BC
LONG TERM...
AVIATION...PW
MARINE...BC/MALOIT
HYDROLOGY...BC
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
420 AM EDT WED APR 30 2014
.SYNOPSIS...
THE THREAT OF STORMY WEATHER WILL CONTINUE INTO TONIGHT. A SLOW
MOVING FRONTAL SYSTEM WILL CROSS THE AREA TONIGHT THEN STALL NEAR
THE COAST FOR THURSDAY. COOL AND DRY HIGH PRESSURE WILL BUILD
ACROSS THE REGION FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN UPPER RIDGE WAS OFF THE EAST COAST WITH A DEEP/LARGE CYCLONE
OVER SOUTHERN MN. THIS PATTERN WILL FINALLY SHIFT BY THURSDAY AS
THE UPPER RIDGE OFF THE COAST MOVES FARTHER OUT TO SEA ALLOWING
THE UPPER LOW TO LIFT NORTHEAST INTO THE GREAT LAKES REGION.
THE SURFACE COLD FRONT EXTENDING FROM CENTRAL KENTUCKY TO THE
LOUISIANA COAST WILL SLOWLY MOVE EAST REACHING THE UPSTATE EARLY
THIS EVENING. OUR AREA WILL REMAIN IN THE WARM SECTOR AHEAD OF THE
FRONT TODAY. PWAT IS FORECAST TO INCREASE TO JUST OVER 1.80
INCHES WITH MODERATE TO STRONG INSTABILITY AS WELL AS STRONG
MOISTURE TRANSPORT AND DIVERGENCE ALOFT. STRONG SHEAR IS FORECAST
WITH H8 WINDS 35 TO 45 KNOTS. SPC STILL HAS THE AREA IN A SLIGHT
RISK FOR SEVERE WEATHER.
CONVECTION WAS INCREASING ACROSS THE MIDLANDS AND CSRA EARLY THIS
MORNING. THE SPC WRF AND HRRR MODELS INDICATE THE BEST CHANCE FOR
CONVECTION THROUGH MIDDAY WITH THE PRECIP SHIFTING CLOSER TO THE
COAST THIS AFTERNOON. CONVECTION ALONG THE GULF COAST COULD ACT TO
DECREASE CONVECTION ACROSS THE MIDLANDS AND CSRA. SO HAVE
INCREASED POPS FOR THE MORNING. POPS IN THE 60 TO 80 PERCENT RANGE
TODAY. HIGH CHANCE POPS LOOK REASONABLE TONIGHT...GIVEN THE
FRONTAL PASSAGE.
LEANED TOWARD THE WARMER GUIDANCE FOR MAX TEMPS TODAY SINCE
TEMPERATURES WILL START THE DAY IN THE UPPER 60S TO LOWER 70S.
WENT WITH CONSENSUS FOR MILD TEMPERATURES IN THE UPPER 50S WEST TO
MID 60S EAST TONIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
THE FRONTAL BOUNDARY WILL REACH THE COAST THURSDAY MORNING THEN
STALL. ALL MODELS SHOW DEEP MOISTURE SHIFT EAST OF THE FORECAST
AREA EARLY THURSDAY. A STABLE AIR MASS AND COLD AIR ADVECTION WILL
OVERSPREAD THE AREA FROM THE WEST...DIMINISHING THE CHANCE FOR
SHOWERS THURSDAY. KEPT A CHANCE FOR SHOWERS FRIDAY ACROSS MAINLY
THE EASTERN PORTION OF THE CWA AS MOISTURE SURGES NORTHWARD ALONG
THE STALLED FRONT. COOLER TEMPERATURES ARE EXPECTED WITH HIGHS IN
THE 75 TO 80 DEGREE RANGE THURSDAY THEN IN THE LOWER 70S FRIDAY.
OVERNIGHT LOWS SHOULD BE IN THE 50S THURSDAY NIGHTS...UPPER 40S TO
LOWER 50S FRIDAY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE GFS AND ECMWF INDICATE A DRY PATTERN FOR THE WEEKEND THROUGH
EARLY NEXT WEEK. SURFACE RIDGING JUST TO THE SOUTH WILL DOMINATE
WITH THE UPPER PATTERN DE-AMPLIFYING. TEMPERATURES THROUGH THE
MEDIUM RANGE PERIOD WILL BEGIN BELOW NORMAL SATURDAY...BEFORE
GRADUALLY WARMING TO ABOVE NORMAL FOR THE BEGINNING OF NEXT WEEK.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS EXPECTED TO DETERIORATE DURING THE EARLY MORNING
HOURS AS A COLD FRONT SLOWLY APPROACHES FROM THE WEST.
AN AREA OF MAINLY LIGHT SHOWERS OVER CENTRAL GA CONTINUES TO SLOWLY
MOVE TOWARDS THE CSRA. AS A COLD FRONT NEAR THE TN VALLEY SLOWLY
MOVES EASTWARD...MOISTURE WILL INCREASE ACROSS THE AREA EARLY THIS
MORNING. LATEST RADAR TRENDS THE SHOWERS WILL MOVE INTO THE CSRA
DURING THE PRE-DAWN HOURS...SO WILL ADD MENTION OF VCSH AT AGS
AND DNL. EXPECT CEILINGS TO DETERIORATE TO MVFR AT ALL TAF SITES
DURING THE EARLY MORNING HOURS. THE POTENTIAL FOR CONVECTION WILL
INCREASE DURING THE DAY. CONFIDENCE IS LOW REGARDING TIMING SO HAVE
USED VCSH FOR LATER THIS MORNING...ALTHOUGH THUNDER WILL BE POSSIBLE
DURING THE AFTERNOON. WILL USE VCTS FOR ALL TAF STIES DURING THE
AFTERNOON AND INTO THE EVENING HOURS. WINDS WILL BE SOUTHERLY AT
AROUND 5 TO 10 KNOTS EARLY THIS MORNING AND WILL INCREASE LATER THIS
MORNING TO AROUND 12 KNOTS WITH GUSTS UP TO 20 KNOTS. WIND SPEEDS
WILL DIMINISH SOMEWHAT BY THIS EVENING.
.EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN SHOWERS AND
THUNDERSTORMS THROUGH THURSDAY MORNING AS THE FRONTAL SYSTEM
SLOWLY CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NWS PEACHTREE CITY GA
140 AM EDT WED APR 30 2014
.UPDATE...
COLD FRONT CURRENTLY STRETCHES FROM NW AL BACK THROUGH CENTRAL LA.
WIDESPREAD SHOWERS WITH EMBEDDED THUNDERSTORMS ARE APPROACHING THE
GA/AL LINE...AND WILL SPREAD EASTWARD THIS EVENING AND INTO THE
OVERNIGHT HOURS. LARGE COMPLEX THAT STRETCHES FROM THE MISSISSIPPI
COAST TO THE FLORIDA PANHANDLE SEEMS TO HAVE CUT OFF MUCH OF THE
INFLOW TO ANY STORMS FURTHER NORTH. RADAR TRENDS OVER THE LAST FEW
HOURS HAVE SHOWN A FEW STRONG STORMS WITHIN THE WIDESPREAD
RAINFALL...BUT NO WARNINGS FOR THE LAST LITTLE BIT.
ATMOS ISNT QUITE AS CONDUCIVE TO WIDESPREAD SEVERE WEATHER. A
FEW STRONG OR ISOLATED SEVERE STORMS WILL CONTINUE TO BE
POSSIBLE...BUT AM GOING TO REMOVE THE WORDING FROM THE PUBLIC
PRODUCTS. WILL STILL HIGHLIGHT THE POTENTIAL FOR ISOLATED
STRONG/SEVERE WITHIN THE HWO. DO THINK THE PRIMARY HAZARD WILL BE
LOCALLY HEAVY RAINFALL.
&&
.PREV DISCUSSION... /ISSUED 739 PM EDT TUE APR 29 2014/
PREV DISCUSSION... /ISSUED 352 PM EDT TUE APR 29 2014/
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
MAIN CONCERN WILL BE WITH SEVERE POTENTIAL THIS EVENING INTO THE
OVERNIGHT WITH THE ANTICIPATED NEXT WAVE OF CONVECTION. THE DAYTIME
PERIOD HAS BEEN LARGELY A LULL IN ACTIVITY DUE TO UPSTREAM
CONVECTION ALONG NORTHERN FLORIDA AND CAPPING FROM LINGERING
MIDLEVEL CLOUD COVERAGE THAT HAS FINALLY STARTED TO MIX OUT. OUT OF
THE SUITE OF HI-RES SOLUTIONS...THE RUC...LOCAL WRF...AND HRRR HAVE
BEEN TRENDING THE BEST WITH PREVIOUS DEVELOPMENT AND LACK THEREOF SO
HAVE LEANED HEAVILY TOWARD THEM WITH OVERNIGHT POPS AND GREATEST
STORM POTENTIAL. THESE MODELS AGREE WITH CONVECTIVE INITIATION
OCCURRING NEAR THE MS/AL BORDER BY 20-21Z...WHICH SEEMS LEGIT GIVEN
AN OBSERVED MESO-LOW TRACKING ALONG THE SFC FRONT IN SOUTHERN MS AND
ALREADY SEEING SOME ENHANCED CU FIELD DEVELOPING. THE EVOLUTION OF
DEVELOPMENT BRINGS CELLS INTO WESTERN PORTIONS OF THE CWA AFTER 00Z
TONIGHT THEN SPREADING NORTH OF THE I-85 CORRIDOR.
THE INSTABILITY AND SHEAR PARAMETERS ARE STILL QUITE FAVORABLE FOR
STRONG TO SEVERE DEVELOPMENT THIS EVENING AND EARLY MORNING WITH
DAMAGING WINDS AND TORNADOES AS THE MAIN THREATS. MLCAPE VALUES ARE
LOOKING TO BE NEAR 1000 J/KG...0-1KM HELICITY AROUND 150
M2/S2...0-1KM BULK SHEAR NEAR 30 KTS...AND 0-6KM BULK IN THE 50-60
KT ZONE FOR THE NORTHWEST HALF OF THE AREA. THE BEST CHANCE FOR
SEVERE DEVELOPMENT LOOKS TO BE IN THE 01Z-07Z PERIOD ALONG AND NORTH
OF THE I-85 CORRIDOR INCLUDING THE ATLANTA METRO AREA. THIS ALSO
COINCIDES WITH INCREASING SREF ENSEMBLE MEAN STP VALUES APPROACHING
2. SHEAR VECTOR ORIENTATION SUPPORTS EMBEDDED OR SEMI-DISCRETE
SUPERCELL CONVECTIVE MODE IN THE 00Z-09Z PERIOD...THEN BECOMES MORE
PARALLEL AS A MORE LINEAR SWATH SETS UP. THIS AGREES WITH CONSENSUS
AMONG THE MODELS AS TRAINING CELLS STALLING ALONG THE I-85 CORRIDOR
IN THE MORNING HOURS IS POSSIBLE. THERE COULD THEREFORE BE AN
INCREASED FLASH FLOODING THREAT. SEE HYDRO SECTION BELOW FOR MORE
DETAILS ON QPF WITH THE EVENT.
THE FRONT FINALLY PUSHES THROUGH WEDNESDAY THOUGH THE ENVIRONMENT
LOOKS LESS FAVORABLE THAN OVERNIGHT TONIGHT FOR SEVERE POTENTIAL.
WHILE THE GREATEST POPS WILL TRANSITION TO SOUTHEAST CWA FOR
WEDNESDAY AFTERNOON...CANNOT RULE OUT SOME STRONG TO ISOLATED SEVERE
POTENTIAL ATTM.
BAKER
LONG TERM /THURSDAY THROUGH TUESDAY/...
NO MAJOR CHANGES MADE TO THE EXTENDED FORECAST. THE COLD FRONT
BRINGING SEVERE WEATHER TO THE STATE IN THE SHORT TERM IS EXPECTED
TO EXIT THE AREA LATE WEDNESDAY NIGHT..ENDING THE THREAT OF SEVERE
STORMS. THE DIFFICULTY THEN BECOMES THE SW UPPER FLOW CONTINUES
THROUGH ABOUT 12Z SAT WITH POTENTIAL FOR MAINLY LIGHT SHOWER AND
THUNDERSTORM CHANCES OVER MAINLY SE PORTION OF THE CWA AS SOME
LESSER MOISTURE MOVES THROUGH THE FLOW. AFTER 12Z SAT THE UPPER
TROUGH MOVES ACROSS THE AREA WITH A DRY FORECAST FOR THE REST OF
THE LONG TERM.
TEMPERATURES WILL TRANSITION TO BELOW NORMAL AT THE START OF THE
LONG TERM THEN BACK TO NORMAL ON SATURDAY AND THEN ABOVE NORMAL THE
REST OF THE LONG TERM.
01
HYDROLOGY...
HPC QPF LOOKS REASONABLE GIVEN THE AFOREMENTIONED STORM TRENDS IN
THE HI-RES SOLUTIONS. THE HEAVIEST AMOUNTS LOOK TO FALL IN THE
OVERNIGHT PERIOD TONIGHT WITH A WIDESPREAD 2 INCHES AND POSSIBLY
HIGHER AMOUNTS WITH TRAINING CELLS ALONG AND NEAR THE I-85 CORRIDOR.
WILL KEEP THE CURRENT FLOOD WATCH GOING THROUGH WEDNESDAY NIGHT.
BAKER
AVIATION...
06Z UPDATE...
RAIN AND A FEW THUNDERSTORMS SHOULD CONTINUE INTO THE MORNING HOURS
WITH MAINLY MVFR CONDITIONS. ISOLATED STORMS COULD BECOME STRONG.
FRONT SHOULD PUSH INTO NORTHWEST GA THIS AFTERNOON WITH SOME
IMPROVING FROM THE NORTHWEST. CONVECTION SHOULD CONCENTRATE OVER
CENTRAL GA THIS AFTERNOON AND EVENING. WINDS VARIABLE OVERNIGHT
BECOMING SOUTHWEST 10 TO 15KT AFTER 14Z.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON ALL ELEMENTS.
41
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 65 78 55 74 / 70 80 50 20
ATLANTA 65 75 53 71 / 80 60 20 10
BLAIRSVILLE 61 70 50 67 / 100 70 20 10
CARTERSVILLE 66 76 49 71 / 100 60 10 10
COLUMBUS 68 80 57 74 / 70 60 40 20
GAINESVILLE 64 75 53 70 / 90 70 30 10
MACON 68 82 58 75 / 50 70 60 30
ROME 65 76 48 70 / 90 60 10 10
PEACHTREE CITY 65 76 51 72 / 80 60 20 20
VIDALIA 70 86 67 78 / 50 60 60 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH LATE WEDNESDAY NIGHT FOR THE FOLLOWING
ZONES: BALDWIN...BANKS...BARROW...BARTOW...BIBB...BLECKLEY...
BUTTS...CARROLL...CATOOSA...CHATTAHOOCHEE...CHATTOOGA...
CHEROKEE...CLARKE...CLAYTON...COBB...COWETA...CRAWFORD...CRISP...
DADE...DAWSON...DEKALB...DODGE...DOOLY...DOUGLAS...EMANUEL...
FANNIN...FAYETTE...FLOYD...FORSYTH...GILMER...GLASCOCK...
GORDON...GREENE...GWINNETT...HALL...HANCOCK...HARALSON...
HARRIS...HEARD...HENRY...HOUSTON...JACKSON...JASPER...
JEFFERSON...JOHNSON...JONES...LAMAR...LAURENS...LUMPKIN...
MACON...MADISON...MARION...MERIWETHER...MONROE...MONTGOMERY...
MORGAN...MURRAY...MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...
OGLETHORPE...PAULDING...PEACH...PICKENS...PIKE...POLK...
PULASKI...PUTNAM...ROCKDALE...SCHLEY...SOUTH FULTON...SPALDING...
STEWART...SUMTER...TALBOT...TALIAFERRO...TAYLOR...TELFAIR...
TOOMBS...TOWNS...TREUTLEN...TROUP...TWIGGS...UNION...UPSON...
WALKER...WALTON...WARREN...WASHINGTON...WEBSTER...WHEELER...
WHITE...WHITFIELD...WILCOX...WILKES...WILKINSON.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
113 AM EDT WED APR 30 2014
.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM WILL APPROACH FROM THE WEST THROUGH
WEDNESDAY. THE FRONT WILL EXTEND THROUGH THE FORECAST AREA
WEDNESDAY NIGHT AND MOVE EAST OF THE AREA THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
DEEP MOISTURE LACKING ACROSS THE AREA EARLY THIS EVENING.
BASED ON LATEST GUIDANCE WILL LOWER POPS THROUGH MIDNIGHT...WITH
CHANCE MAINLY ALONG THE NORTH CAROLINA BORDER NEAR STATIONARY
FRONT. WITH COLD FRONT MOVING INTO NORTH GEORGIA LATE TONIGHT MAY
SEE SHOWERS DEVELOPING IN THE WEST MIDLANDS/PIEDMONT AND CSRA. THE
LATEST HRRR SUGGESTS CONVECTION ALONG THE GULF COAST MAY SPREAD
NORTHEAST OVERNIGHT ASSOCIATED WITH WEAK SHORT WAVE TROUGH
ROTATING AROUND STACKED LOW OVER THE MIDWEST. SO CHANCE POPS AND
INCREASING FROM SOUTHWEST TO NORTHEAST TOWARD MORNING. INSTABILITY
WEAK TO MODERATE BUT DEEP LAYER SHEAR MAY INCREASE BY DAYBREAK.
USED THE WARMER TEMPERATURE GUIDANCE BECAUSE OF CLOUDINESS AND
MIXING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
MOISTURE SHOULD BECOME DEEP JUST AHEAD OF THE SLOW MOVING COLD
FRONT. BELIEVE THE FRONT WILL BE JUST WEST OF THE FORECAST AREA
WEDNESDAY AND EXTEND THROUGH THE AREA WEDNESDAY NIGHT. THE NAM
SHOWS PRECIPITABLE WATER INCREASING TO NEAR 1.9 OF AN INCH BY
WEDNESDAY AFTERNOON. SHEAR WILL BE HIGH. THE MODELS INDICATE
A 40-KNOT H85 JET. THE MOISTURE AND CONVERGENCE ASSOCIATED WITH
THE FRONT SUPPORT LIKELY OR CATEGORICAL POPS. THE NAM INDICATES
SURFACE-BASED LI/S NEAR -5 WEDNESDAY AND WEDNESDAY EVENING. THE
INSTABILITY AND SHEAR SUPPORT POSSIBLE SEVERE THUNDERSTORMS. HIGH
PRECIPITABLE WATER AND POSSIBLE TRAINING SUPPORTS HEAVY RAIN. THE
NAM...GFS...AND SREF MEAN ARE ALL BELOW FLASH FLOOD GUIDANCE SO WE
HAVE HELD OFF ISSUING A FLOOD WATCH FOR NOW.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE NAM AND GFS CONTINUE TO INDICATE DEEP MOISTURE WILL SHIFT EAST
OF THE FORECAST AREA EARLY THURSDAY. THE FRONT WILL SHIFT JUST OFF
THE COAST. THE NAM INDICATES SURFACE-BASED LI/S ABOVE 0 BY 12Z
THURSDAY. THE SHOWER CHANCE SHOULD DIMINISH FROM WEST TO EAST. THE
GFS AND ECMWF INDICATE A DRY PATTERN DURING THE REST OF THE
MEDIUM-RANGE PERIOD. MOISTURE ASSOCIATED WITH THE FRONT APPEARS TO
REMAIN SOUTH AND EAST OF THE AREA EARLY. DRY SURFACE RIDGING JUST
TO THE SOUTH APPEARS TO DOMINATE DURING THE MIDDLE AND LATE PART
OF THE PERIOD. THE GFS...ECMWF...AND EKD MOS PLUS GFS ENSEMBLE
MEAN INDICATE POPS AROUND 20 PERCENT EARLY...AND LESS THAN 20
PERCENT DURING THE REST OF THE PERIOD. THE GUIDANCE WAS CONSISTENT
WITH TEMPERATURES NEAR CLIMATOLOGY.
&&
.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS EXPECTED TO DETERIORATE OVERNIGHT AS COLD FRONT
SLOWLY APPROACHES FROM THE WEST.
CHANCES OF SHOWERS AND STORMS REMAINS LOW ACROSS THE AREA INTO THE
OVERNIGHT HOURS. AS THE COLD FRONT APPROACHES FROM THE WEST
...MOISTURE WILL INCREASE ACROSS THE AREA. LATEST RADAR TRENDS
INDICATING SCTD SHOWERS OVER CENTRAL GA MAY MOVE INTO THE CSRA
BEFORE 08Z...SO WILL ADD MENTION OF VCSH AT AGS AND DNL. EXPECT
CEILINGS TO DETERIORATE TO MVFR BY 09Z AND REMAIN MVFR OR LOWER
THROUGH DAYBREAK. MVFR CEILINGS SHOULD IMPROVE WEDNESDAY MORNING AND
POTENTIAL FOR CONVECTION WILL INCREASE DURING THE DAY. CONFIDENCE IS
LOW REGARDING TIMING SO HAVE USED VCSH FOR LATER THIS
MORNING...ALTHOUGH THUNDER WILL BE POSSIBLE DURING THE AFTERNOON.
WILL USE VCTS FOR ALL TAF STIES DURING THE AFTERNOON AND INTO THE
EVENING HOURS. WINDS WILL BE SOUTHERLY AT AROUND 5 TO 10 KNOTS EARLY
THIS MORNING AND WILL INCREASE LATER THIS MORNING TO AROUND 12 KNOTS
WITH GUSTS UP TO 20 KNOTS. WIND SPEEDS WILL DIMINISH SOMEWHAT BY
THIS EVENING.
.EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN SHOWERS AND
THUNDERSTORMS THROUGH THURSDAY NIGHT AS THE FRONTAL SYSTEM SLOWLY
CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1245 AM EDT WED APR 30 2014
.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM WILL APPROACH FROM THE WEST THROUGH
WEDNESDAY. THE FRONT WILL EXTEND THROUGH THE FORECAST AREA
WEDNESDAY NIGHT AND MOVE EAST OF THE AREA THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
DEEP MOISTURE LACKING ACROSS THE AREA EARLY THIS EVENING.
BASED ON LATEST GUIDANCE WILL LOWER POPS THROUGH MIDNIGHT...WITH
CHANCE MAINLY ALONG THE NORTH CAROLINA BORDER NEAR STATIONARY
FRONT. WITH COLD FRONT MOVING INTO NORTH GEORGIA LATE TONIGHT MAY
SEE SHOWERS DEVELOPING IN THE WEST MIDLANDS/PIEDMONT AND CSRA. THE
LATEST HRRR SUGGESTS CONVECTION ALONG THE GULF COAST MAY SPREAD
NORTHEAST OVERNIGHT ASSOCIATED WITH WEAK SHORT WAVE TROUGH
ROTATING AROUND STACKED LOW OVER THE MIDWEST. SO CHANCE POPS AND
INCREASING FROM SOUTHWEST TO NORTHEAST TOWARD MORNING. INSTABILITY
WEAK TO MODERATE BUT DEEP LAYER SHEAR MAY INCREASE BY DAYBREAK.
USED THE WARMER TEMPERATURE GUIDANCE BECAUSE OF CLOUDINESS AND
MIXING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
MOISTURE SHOULD BECOME DEEP JUST AHEAD OF THE SLOW MOVING COLD
FRONT. BELIEVE THE FRONT WILL BE JUST WEST OF THE FORECAST AREA
WEDNESDAY AND EXTEND THROUGH THE AREA WEDNESDAY NIGHT. THE NAM
SHOWS PRECIPITABLE WATER INCREASING TO NEAR 1.9 OF AN INCH BY
WEDNESDAY AFTERNOON. SHEAR WILL BE HIGH. THE MODELS INDICATE
A 40-KNOT H85 JET. THE MOISTURE AND CONVERGENCE ASSOCIATED WITH
THE FRONT SUPPORT LIKELY OR CATEGORICAL POPS. THE NAM INDICATES
SURFACE-BASED LI/S NEAR -5 WEDNESDAY AND WEDNESDAY EVENING. THE
INSTABILITY AND SHEAR SUPPORT POSSIBLE SEVERE THUNDERSTORMS. HIGH
PRECIPITABLE WATER AND POSSIBLE TRAINING SUPPORTS HEAVY RAIN. THE
NAM...GFS...AND SREF MEAN ARE ALL BELOW FLASH FLOOD GUIDANCE SO WE
HAVE HELD OFF ISSUING A FLOOD WATCH FOR NOW.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE NAM AND GFS CONTINUE TO INDICATE DEEP MOISTURE WILL SHIFT EAST
OF THE FORECAST AREA EARLY THURSDAY. THE FRONT WILL SHIFT JUST OFF
THE COAST. THE NAM INDICATES SURFACE-BASED LI/S ABOVE 0 BY 12Z
THURSDAY. THE SHOWER CHANCE SHOULD DIMINISH FROM WEST TO EAST. THE
GFS AND ECMWF INDICATE A DRY PATTERN DURING THE REST OF THE
MEDIUM-RANGE PERIOD. MOISTURE ASSOCIATED WITH THE FRONT APPEARS TO
REMAIN SOUTH AND EAST OF THE AREA EARLY. DRY SURFACE RIDGING JUST
TO THE SOUTH APPEARS TO DOMINATE DURING THE MIDDLE AND LATE PART
OF THE PERIOD. THE GFS...ECMWF...AND EKD MOS PLUS GFS ENSEMBLE
MEAN INDICATE POPS AROUND 20 PERCENT EARLY...AND LESS THAN 20
PERCENT DURING THE REST OF THE PERIOD. THE GUIDANCE WAS CONSISTENT
WITH TEMPERATURES NEAR CLIMATOLOGY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS EXPECTED TO DETERIORATE OVERNIGHT AS COLD FRONT
SLOWLY APPROACHES FROM THE WEST.
CHANCES OF SHOWERS AND STORMS REMAINS LOW ACROSS THE AREA INTO THE
OVERNIGHT HOURS. AS THE COLD FRONT APPROACHES FROM THE WEST
...MOISTURE WILL INCREASE ACROSS THE AREA. EXPECT CEILINGS
TO DETERIORATE TO MVFR BY 09Z AND REMAIN MVFR OR LOWER THROUGH
DAYBREAK. MVFR CEILINGS SHOULD IMPROVE WEDNESDAY MORNING AND
POTENTIAL FOR CONVECTION WILL INCREASE DURING THE DAY. CONFIDENCE IS
LOW REGARDING TIMING SO HAVE USED VCSH FOR LATER THIS
MORNING...ALTHOUGH THUNDER WILL BE POSSIBLE DURING THE AFTERNOON.
WILL USE VCTS FOR ALL TAF STIES DURING THE AFTERNOON AND INTO THE
EVENING HOURS. WINDS WILL BE SOUTHERLY AT AROUND 5 TO 10 KNOTS EARLY
THIS MORNING AND WILL INCREASE LATER THIS MORNING TO AROUND 12 KNOTS
WITH GUSTS UP TO 20 KNOTS. WIND SPEEDS WILL DIMINISH SOMEWHAT BY
THIS EVENING.
.EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN SHOWERS AND
THUNDERSTORMS THROUGH THURSDAY NIGHT AS THE FRONTAL SYSTEM SLOWLY
CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
248 AM EDT WED APR 30 2014
.UPDATE...
ISSUED AT 248 AM EDT WED APR 30 2014
UPLOADED LATEST OBSERVATIONS INTO THE GRIDS AS TEMPS WERE OFF
SLIGHTLY. OTHERWISE THE FORECAST IS ON TRACK AND THE NEWEST ZFP WILL
BE ISSUED WITH THE MORNING FORECAST PACKAGE.
UPDATE ISSUED AT 1115 PM EDT TUE APR 29 2014
THE GRIDS WERE UPDATED BASED ON RECENT RADAR AND OBSERVATION TRENDS.
THE THREAT OF CONVECTION WILL LINGER ACROSS THE REGION TONIGHT AS A
COLD FRONT WORKS INTO THE REGION. IN ADDITION...THE UPPER LEVEL
TROUGH AXIS WILL REMAIN TO THE WEST OF THE REGION OVERNIGHT WITH
UPPER LEVEL DISTURBANCE ROTATING ACROSS THE LOWER OH VALLEY
OVERNIGHT. THE THREAT FOR SEVERE WEATHER HAS DIMINISHED...BUT IF
STORMS TRAIN OR REDEVELOP...LOCALLY HEAVY RAIN WOULD BE POSSIBLE.
UPDATE ISSUED AT 840 PM EDT TUE APR 29 2014
SHOWER AND THUNDERSTORM ACTIVITY SHOULD BE MOST PREVALENT ALONG THE
WESTERN EDGE OF THE CWA OVER THE NEXT COUPLE OF HOURS...BUT SHORT
TERM MODELS GRADUALLY BRING ACTIVITY EAST. THIS SEEMS REASONABLE. THERE
ARE SEVERAL OUTLFOW BOUNDARIES WORKING ACROSS THE AREA...ONE IS MOVING
THE NORTHWEST ACROSS THE SOUTHWEST COUNTIES AND ANOTHER IS MOVING
EAST OF INTERSTATE 75 OVER THE SOUTHWESTERN CWA. ANOTHER OUTFLOW
BOUNDARY IS MOVING EAST ACROSS THE NORTHERN CWA. THERE IS UNCERTAINTY
AS TO HOW THE INTERACTION OF THESE EVOLVES AND CONVECTION WILL NEED
TO BE WATCHED FOR ANY TRAINING. THE OTHER THREATS FOR THE NEXT COUPLE
OF HOURS APPEARS TO BE MARGINALLY SEVERE HAIL AND DAMAGING WINDS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 340 PM EDT TUE APR 29 2014
18Z SFC ANALYSIS SHOWS OUR NEMESIS OF A BROAD STACKED LOW CENTERED
OVER EASTERN IOWA. EAST KENTUCKY REMAINS IN THE SYSTEM/S SOUPY WARM
SECTOR AS DEWPOINTS ARE STARTING TO COME BACK UP FROM THE MIDDAY
DROPOFF WITH SOME NOW TO NEAR 60 DEGREES IN THE EAST. EXPECT THESE
TO CONTINUE TO COME UP THROUGH THE REST OF THE AFTERNOON.
TEMPERATURES...MEANWHILE...ARE GENERALLY IN THE MID AND UPPER 70S
THROUGH THE AREA. THIS IS ENOUGH FOR SOME SHOWERS AND THUNDERSTORMS
TO DEVELOP OVER THE EAST IN THE WAKE OF THIS MORNING/S BOUNDARY AND
ITS ILL-FATED ATTEMPT TO PULL AWAYS FROM THIS PART OF THE STATE. THIS
BONUS CONVECTION WILL NEED TO BE WATCHED FOR STRONGER DEVELOPMENT
GIVEN THE ENVIRONMENT...BUT THE MAIN THREAT LIKELY ARRIVES FOR EAST
KENTUCKY CLOSER TOWARD SUNSET AND FROM THE SOUTHWEST. WINDS ARE
BREEZY OUT OF THE SOUTHWEST FOR MOST OF THE AREA WITH GUSTS TO 20 KTS
OR SO.
THE MODELS REMAIN IN PRETTY GOOD AGREEMENT ALOFT WITH THE BROAD CUT
OFF LOW SLOWLY TUMBLING NORTHEAST INTO THE GREAT LAKES BY THURSDAY
MORNING. THIS PROCESS WILL INVOLVE A COUPLE OF LINGERING SHORTWAVES
RIDING THE FAST MID LEVEL FLOW BENEATH THE LOW...RUNNING ACROSS
WESTERN KENTUCKY AND THEN NORTHEAST INTO THE OHIO VALLEY. THE FIRST
OF THESE MOVES THROUGH KENTUCKY TOWARD MIDNIGHT WHILE ANOTHER PASSES
BY LATER WEDNESDAY. HAVE FOLLOWED A MODEL BLEND FOR THE FORECAST
WHILE LEANING TOWARD THE HRRR AND NAM12 FOR DETAILS TONIGHT.
SENSIBLE WEATHER WILL FEATURE AN ACTIVE EVENING AND EARLY OVERNIGHT
WITH A DECENT POTENTIAL FOR DAMAGING WIND GUSTS FROM THE STRONGER
STORMS WHILE LARGE HAIL AND AN ISOLATED TORNADO CANNOT BE RULED OUT
SHOULD BE SOME DISCREET CELLS EXHIBIT SUPERCELL CHARACTERISTICS.
HAVE TIMED THESE THROUGH THE CWA MAINLY IN THE EVENING EXPECTING MORE
STABLE AIR TO DEVELOP AFTER 06Z FROM THE EVENING STORMS. HOWEVER...
LOCALIZED HEAVY RAIN WILL REMAIN A CONCERN WHERE ANY STORMS TRAIN.
MORE WIDESPREAD RAINS OVER THE CUMBERLAND VALLEY WILL NEED TO BE
WATCHED CLOSELY AS THE FFG IS THE LOWEST THERE OWING TO THE TWO PLUS
INCHES THAT FELL THERE LAST NIGHT. THERE REMAINS JUST TOO MUCH
UNCERTAINTY TO GO WITH A FLOOD WATCH FOR THIS PART OF THE EAST
KENTUCKY WITH THE GFS KEEPING ITS HEAVIER BAND TO THE NORTHWEST AND
THE NAM PLACING ITS OWN TO THE EAST OF THE LOWER FFG AREAS. WILL
MONITOR THE SITUATION THROUGH THE EVENING FOR A POSSIBLE SHORTER FUSE
WATCH DEPENDING HOW THE STORMS AND ANY TRAINING DEVELOPS.
FOR WEDNESDAY...HAVE INCLUDED A SLIGHT CHANCE OF THUNDER THROUGH NOON
IN THE WEST UNTIL THE LIS GO STRONGLY POSITIVE IN THE AFTERNOON AS
THE SFC WINDS GO WEST AND A COLD FRONT MOVES ON THROUGH. DID DROP
THE THUNDER FURTHER EAST WITH TIME. CARRIED A SMALL CHANCE OF SHOWERS
THROUGH THE EVENING AND INTO THE NIGHT OVER THE EASTERN PARTS OF THE
AREA...BUT RAINFALL AMOUNTS AND CONVECTIVE DEVELOPMENT WILL BE RATHER
PALTRY POST COLD FRONT.
USED THE CONSSHORT...AND THE BC VERSION...AS A STARTING POINT FOR THE
GRIDS THROUGH THE NEXT 24 HOURS WITH THE CONSALL PRELOADED THEREAFTER.
MADE ONLY SOME SMALL ADJUSTMENTS TO THE NUMBERS MAINLY TO CAPTURE THE
CURRENT CONDITIONS AND TRENDS. AS FOR POPS...ENDED UP ON THE HIGH
SIDE OF ALL GUIDANCE TONIGHT AND THROUGH THE FORECAST...CLOSER TO THE
MET NUMBERS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 300 PM EDT TUE APR 29 2014
MODELS REMAIN IN GOOD AGREEMENT WITH THE EVOLUTION OF THE UPPER AIR
PATTERN THROUGH THE END OF THE THE WEEK AND INTO EARLY NEXT WEEK.
THE LARGE UPPER LOW OVER THE UPPER MS VALLEY/UPPER GREAT LAKES AT
THE START OF THE PERIOD WILL MAKES ITS WAY INTO CANADA ON FRIDAY. AFTER
THIS THERE WILL BE OCCASIONAL SHORT WAVE TROUGHS PASSING BY AS A
MEAN LONG WAVE TROUGH REMAINS OVER THE EASTERN PART OF THE U.S. INTO
EARLY NEXT WEEK. ANOTHER UPPER LOW IS FORECAST TO MOVE ACROSS THE
NORTHERN GREAT LAKES LATE IN THE WEEKEND AND INTO NEW ENGLAND BY
EARLY NEXT WEEK.
THE PRIMARY FORECAST CHALLENGE REVOLVES AROUND PRECIPITATION CHANCES
WITH ANY PASSING SHORT WAVES...AND THE PASSAGE OF A WEAK COLD FRONT
THIS WEEKEND. HAVE FOLLOWED A BLENDED MODEL AND INHERITED FORECAST
APPROACH FOR RAIN CHANCES FOR MOST OF THE LONG RANGE PERIOD WHICH
YIELDS VERY LOW PROBABILITIES FOR MAINLY AFTERNOON SHOWERS EACH DAY
FROM THURSDAY THROUGH SUNDAY. WILL NOT MENTION ANY RAIN CHANCE FOR
MONDAY OR TUESDAY BUT LOW RAIN CHANCES MAY NEED TO BE INTRODUCED IN
LATER FORECASTS AS IT APPEARS A WARM FRONT WILL BE MOVING ACROSS THE
AREA. BELOW NORMAL TEMPERATURES WILL PREVAIL THROUGH THE FIRST PART
OF THE FORECAST PERIOD...WITH RISING HEIGHTS EARLY NEXT WEEK LEADING
TO A WARMING TREND AS WE MOVE INTO TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 248 AM EDT WED APR 30 2014
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO MOVE ACROSS THE TAF SITES
DURING THE FIRST 6 HOURS OF THE PERIOD. DURING HEAVIER RAIN IN SHRA
AND TSRA AND AS THE ATMOSPHERE GRADUALLY SATURATES IN THE LOW
LEVELS...SOME MVFR TO IFR CONDITIONS ARE ANTICIPATED...AT LEAST AT
TIMES. WINDS WILL BE GENERALLY OUT OF THE SOUTH AND SOUTHWEST THROUGH
THE FIRST PART OF THE FORECAST. WINDS WILL INCREASE BY THIS AFTERNOON
OUT OF THE WEST AS THE FRONT SLOWLY MOVES THROUGH THE AREA LATER
TODAY WITH GUSTS REACHING UP TO 25 KNOTS. SHOWERS AND A THUNDERSTORM
WILL STILL BE POSSIBLE TODAY SO WILL KEEP SOME MVFR CONDITIONS
THROUGH THE MORNING AND GRADUALLY IMPROVE CONDITIONS THIS AFTERNOON
AND EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM...SBH
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
237 AM EDT WED APR 30 2014
.SYNOPSIS...
A CUTOFF LOW WILL DRIFT OVER THE GREAT LAKES TODAY. A WARM FRONT
OVER NORTH CAROLINA WILL LIFT NORTHWARD INTO THE REGION TODAY AND
TONIGHT. A COLD FRONT WILL MOVE THROUGH THE AREA THURSDAY. HIGH
PRESSURE IS EXPECTED TO RETURN FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
EVENING WATER VAPOR LOOP SHOWS THE ERN TWO-THIRDS OF THE CONUS UNDER
BROAD CYCLONIC FLOW IN ASSOCIATION WITH A CUTOFF LOW OVER THE
UPPER MIDWEST. A UNUSUALLY DEEP SLY FETCH DOWNSTREAM OF THE CUTOFF
LOW CONTINUES TO DRAW TROPICAL MOISTURE FROM THE GULF OF MEXICO
AND ATLANTIC UP THE ERN SEABOARD. BACKWARD TRAJECTORIES EVEN SHOW
MOISTURE ALL THE WAY FROM THE CARIBBEAN REACHING THE MID-ATLANTIC
REGION BY WED.
AT THE SFC...A WARM FRONT WAS SITUATED IN NC AS OF 00Z AND IS
STARTING TO NUDGE NWD TOWARD EXTREME SERN VA. THE CWA WILL
CONTINUE TO BE SITUATED IN COOL SECTOR TO THE NORTH OF THE
BOUNDARY TNGT AS A COLD AIR DAMMING WEDGE HOLDS STRONG. TEMPS CWA
WIDE ARE IN THE UPPER 40S AND LOWER 50S THIS EVE UNDER THE
INFLUENCE OF ONSHORE FLOW. WINDS ARE EXPECTED TO GRADUALLY VEER
MORE OUT OF THE SE OVNGT AS THE WARM FRONT APPROACHES FROM THE
SOUTH. TEMPS WILL REMAIN STEADY OR GRADUALLY INCREASE LATE TNGT AS
A RESULT.
SHOWERS AND TSTMS THAT DEVELOPED IN SERN VA WILL CONTINUE TO MOVE
NWD INTO THE CWA...IMPACTING LOCATIONS EAST OF THE BLUE RIDGE THRU
THE REMAINDER OF THE EVE. 00Z IAD RAOB SHOWS VERY LIMITED CAPE
AVAILABLE FOR ELEVATED CONVECTION ABOVE H8 WARM NOSE SO CHANCES FOR
TSTMS LOW THIS EVE AS THIS ACTIVITY MOVES INTO AN INCREASINGLY
STABLE AIRMASS. PRECIP EXPECTED TO REDEVELOP LATE TNGT ACROSS THE
CWA IN ASSOCIATION WITH A 40+ KT SLY LLVL JET PRODUCING ISENTROPIC
LIFT ACROSS THE WARM FRONT. FCST MODEL SOUNDINGS SHOW PWATS AND
ELEVATED INSTABILITY ALSO INCREASING FROM SOUTH TO NORTH...SO HVY
DOWNPOURS AND TSTMS WILL INCREASE THE THREAT OF FLASH FLOODING AS WE
HEAD TOWARD THE ERY MRNG.
THE LATEST RAP AND 18Z NAM/GFS BRING THE WARM FRONT STEADILY
NORTHWARD THRU THE REGION ON WED. AM SKEPTICAL OF HOW QUICKLY THE
WARM FRONT ACTUALLY MAKES IT THRU THE REGION THOUGH AS MODELS
TYPICAL ARE TOO AGGRESSIVE WITH ERODING THE CAD WEDGE. THE POSITION
OF THE WARM FRONT WILL DETERMINE NOT ONLY TEMPS BUT WHERE THE
GREATEST THREAT OF SEVERE STORMS INCLUDING THE POTENTIAL FOR
TORNADOES WILL EXIST. IF THE WARM FRONT LINGERS NEAR THE CWA DURING
THE AFTN...THE TORNADO THREAT WOULD BE GREATEST ALONG AND JUST TO
THE SOUTH OF THE BOUNDARY.
PREVIOUS DISCUSSION...
THE WARM FRONT WILL MOVE INTO THE AREA WEDNESDAY FROM SOUTH TO
NORTH. DEEP MOISTURE WILL CONTINUE TO ADVECT INTO THE AREA DURING
THIS TIME...CAUSING MORE WIDESPREAD RAINFALL ALONG WITH AN
INCREASING THREAT FOR THUNDERSTORMS. A SHEAR VECTOR NEARLY
PARALLEL TO THE COLD FRONT ASSOCIATED WITH THIS LOW MEANS THAT
BANDS OF SHOWERS AND THUNDERSTORMS WILL TRAIN OVER ONE ANOTHER.
PWATS WILL BE NEAR RECORD LEVELS FOR THIS TIME OF YEAR...AND WITH
TRAINING CONVECTION THERE WILL BE AREAS OF VERY HEAVY RAINFALL IN
A SHORT PERIOD OF TIME. THE FLASH FLOOD WATCH CONTINUES THROUGH
WEDNESDAY.
THUNDERSTORMS WILL BECOME ROOTED WITHIN THE BOUNDARY
LAYER...ESPECIALLY LATER WEDNESDAY MORNING THROUGH WEDNESDAY
AFTERNOON AS INSTABILITY INCREASES BEHIND THE WARM FRONT. SHEAR
PROFILES WILL BE VERY STRONG...INCREASING THE CHANCE FOR SEVERE
WEATHER. THE PRIMARY THREATS WILL BE DAMAGING WINDS AND ISOLATED
TORNADOES. THE BEST CHANCE FOR THIS TO OCCUR WILL BE FROM WESTERN
MARYLAND AND EASTERN WEST VIRGINIA ACROSS NORTHERN AND CENTRAL
VIRGINIA INTO EXTREME SOUTHERN MARYLAND.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
A SEVERE WEATHER THREAT WILL PERSIST INTO THE EVENING HOURS
WEDNESDAY...EXPANDING NORTH INTO MARYLAND AS THE WARM FRONT AND
UNSTABLE AIR EXPAND NORTHWARD VIA A 40-KNOT LOW-LEVEL JET.
LARGE...LOOPING HODOGRAPHS INDICATE A FAVORABLE ENVIRONMENT FOR
ROTATING UPDRAFTS...AND SUGGESTS THAT STORMS ROOTED IN THE BOUNDARY
LAYER COULD POSE A TORNADO RISK TOMORROW EVENING GIVEN MEAN AND
RIGHT-MOVING STORM MOTION VECTORS LARGELY PARALLEL TO 0-1 KM
VORTICITY VECTOR. THIS IS ALSO SUPPORTED BY HELICITY VALUES OF 300
TO 500 M2/S2 IN THE VICINITY OF THE WARM FRONT MOVING NORTH ACROSS
THE POTOMAC RIVER DURING THE EVENING. THE MAGNITUDE OF THIS RISK
WILL BE MODULATED BY HOW MUCH SURFACE HEATING OCCURS DURING THE
AFTERNOON...BUT MOST GUIDANCE INCLUDING THE LATEST SREF INDICATE
MLCAPE ON THE ORDER OF 500-1000 J/KG /HIGHEST SOUTH/ WHICH SHOULD BE
SUFFICIENT FOR ORGANIZED SEVERE CONVECTION GIVEN RICH MOISTURE AND A
MODERATELY FORCED SYNOPTIC ENVIRONMENT.
SHEAR PROFILES WILL GRADUALLY BECOME LESS FAVORABLE FOR ROTATING
UPDRAFTS LATER IN THE EVENING...AND INCREASING STABILITY WITH THE
ONSET OF A NOCTURNAL INVERSION AS WELL AS CONVECTIVE OVERTURNING
WILL RESULT IN A DECREASING SEVERE WEATHER THREAT DURING THE
OVERNIGHT. HOWEVER THE PARENT COLD FRONT IS A SLOW-MOVER...AND AS
SUCH MULTIPLE ROUNDS OF SHOWERS AND ELEVATED THUNDERSTORMS
CONTAINING HEAVY RAINFALL WILL PERSIST THROUGH MUCH OF THE NIGHT
ESPECIALLY EAST OF THE BLUE RIDGE MOUNTAINS. FOR MORE ON THE
FLOOD/FLASH FLOOD THREAT...PLEASE SEE THE HYDROLOGY SECTION BELOW.
POCKETS OF SHOWERS OR EVEN A FEW THUNDERSTORMS COULD LINGER INTO
THURSDAY AS THE COLD FRONT SLOWLY SLIDES OFF THE COAST. HIGH
PRESSURE WILL BUILD INTO THE REGION TO END THE WEEK WITH
TEMPERATURES NEAR OR SLIGHTLY BELOW NORMAL EXPECTED IN A MUCH DRIER
REGIME.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE LONG TERM FORECAST WILL BE MUCH QUIETER THAN THE NEAR AND SHORT
TERMS OVERALL. A COLD FRONT EXTENDING SOUTH FROM LOW PRESSURE OVER
THE HUDSON BAY MAY BRING SOME BRIEF LIGHT SHOWERS ALONG THE HIGHER
ELEVATIONS IN THE MOUNTAINS AND THE MASON-DIXON LINE DURING THE DAY
SATURDAY. NOT EXPECTING THE FRONT TO BE STRONG ENOUGH TO BRING ANY
PRECIP TO AREAS EAST OF THE BLUE RIDGE AND ALONG AND SOUTH OF THE
METRO AREAS CURRENTLY. THE PRIMARY IMPACT FOR MOST OF THE AREA WILL
BE AN INCREASE IN CLOUDS...RESULTING IN PARTLY SUNNY SKIES AS THE
FRONT PASSES.
A SECONDARY DRY COLD FRONT WILL SWING THROUGH SUNDAY AS THE LOW
CROSSES NEW ENGLAND. THIS FRONT WILL ONLY BRING A SLIGHT INCREASE IN
CLOUDS AS THERE IS LITTLE DIFFERENCE BETWEEN THE AIR MASSES ON
EITHER SIDE OF THE BOUNDARY. HIGH PRESSURE WILL FILL BACK IN FOR THE
BEGINNING OF THE WORKWEEK BEFORE A STATIONARY/WARM FRONT MAY DEVELOP
OVER THE MID ATLANTIC ON TUESDAY.
TEMPERATURES WILL BE RATHER CONSISTENT THROUGH THE LONG TERM. HIGHS
WILL GENERALLY BE IN THE UPPER 60S NORTH OF I66 AND IN THE LOWER 70S
ALONG THE CENTRAL VA PIEDMONT. LOWS WILL BE IN THE MID 40S TO LOWER
50S THROUGHOUT THE TERM.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
A WARM FRONT WILL APPROACH FROM THE SOUTH TNGT. THE TERMINALS WILL
BE LOCATED IN COOL ELY FLOW AND LOW CLOUDS TNGT. CIGS PREDOMINATELY
IN IFR CAT TNGT. PERIOD OF SHRA WILL BE HEAVY AT TIMES
TNGT...RESULTING IN PERIOD OF IFR VSBYS. A FEW THUNDERSTORMS ARE
POSSIBLE ESPECIALLY AFTER 06Z.
HEAVY SHOWERS AND THUNDERSTORMS WILL CONTINUE WEDNESDAY WITH IFR
CONDITIONS. THUNDERSTORMS MAY BECOME SEVERE...WITH DAMAGING WINDS
AND ISOLATED TORNADOES BEING THE PRIMARY THREAT. THE BEST CHANCE
FOR SEVERE THUNDERSTORMS WILL BE IN THE AFTERNOON. CIGS START OFF
IN IFR BUT MAY IMPROVE TO MVFR BEHIND THE WARM FRONT. WINDS SHIFT
OUT OF THE S-SE AND INCREASE TO 15-25 KT IN WAKE OF FROPA AS WELL.
MODERATE CONFIDENCE IN SUB-VFR CONDITIONS IN HEAVY RAINFALL AND
THUNDERSTORMS WEDNESDAY NIGHT...THEN GRADUALLY IMPROVING TO VFR
THURSDAY AND PERSISTING INTO FRIDAY AS HIGH PRESSURE BUILDS.
CONFIDENCE IS LOW FOR ANY AVIATION HAZARDS IN THE LONG TERM.
&&
.MARINE...
UPGRADED TO A GALE WRNG FOR THE MD CHSPK BAY SOUTH OF SANDY POINT
AND FOR THE LWR TIDAL POTOMAC RVR THRU WED NGT. WHILE WINDS WILL
GENERALLY BE BETWEEN 20-30 KT IN THESE ZONES...HVY SHOWERS AND
STORMS WILL TRANSPORT HIGHER WINDS ALOFT DOWN TO THE SFC. ALREADY
HAD 35 KT GUSTS OCCUR AT THE LOWER HOOPER ISLAND AND BISHOPS HEAD
BUOYS LATE THIS AFTN DESPITE NO LIGHTNING. GIVEN THE HIGH
FREQUENCY OF THESE HEAVIER SHOWERS AND STORMS EXPECTED OVER THE
NEXT 36 HRS...A GALE WARNING WOULD COVER THIS THREAT. THE GALE
WARNING MAY NEED TO BE EXPANDED NWD BUT CONFIDENCE NOT HIGH ENOUGH
TO UPGRADE ATTM WITH THE NRN MARINE ZONES SITUATED DEEPER INTO
THE COOLER/STABLE SECTOR FARTHER TO THE NORTH OF THE WARM FRONT.
PREVIOUS DISCUSSION...
A WARM FRONT WILL APPROACH THE WATERS TONIGHT AND THE PRESSURE
GRADIENT WILL REMAIN STRONG AHEAD OF THE BOUNDARY. A SMALL CRAFT
ADVISORY IS IN EFFECT FOR THE WATERS DURING THIS TIME. THE SMALL
CRAFT ADVISORY CONTINUES THROUGH WEDNESDAY AS THE WARM FRONT MOVES
OVERHEAD. A GALE WARNING MAY ALSO BE NEEDED FOR PORTIONS OF THE
WATERS WEDNESDAY.
A STRONG SOUTHERLY LOW-LEVEL JET AHEAD OF A SLOW-MOVING COLD FRONT
WILL RESULT IN MODERATE TO HIGH SMALL CRAFT LEVEL GUSTS /25-30 KTS/
WEDNESDAY INTO WEDNESDAY NIGHT. GALE GUSTS ARE POSSIBLE FOR A TIME
AS WELL ON AREA WATERS...BOTH SYNOPTICALLY AND IN STRONGER
CONVECTION. SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN AND GUSTY
WINDS WILL LOCALLY REDUCE VISIBILITY AND INCREASE SEAS WEDNESDAY
INTO WEDNESDAY NIGHT. SMALL CRAFT ADVISORY GUSTS ARE LIKELY IN
NORTHWEST FLOW BEHIND THE FRONT THURSDAY AFTERNOON. QUIETER WEATHER
WILL RETURN TO THE WATERS FRIDAY. CONFIDENCE IS LOW FOR ANY MARINE
HAZARDS IN THE LONG TERM.
&&
.HYDROLOGY...
RAIN CONTINUES TO SPREAD BACK INTO THE AREA THIS EVE...WITH
CONVECTION DEVELOPING OVER SRN/CENTRAL VA. ADDITIONAL RAINFALL IS
FORECAST TO FUNNEL INTO THE AREA OVNGT. THIS PRECIPITATION WILL
BE AIDED IN ITS CONTINUED DEVELOPMENT BY THREE FACTORS...LOW-
LEVEL UPSLOPE FLOW TOWARD THE BLUE RIDGE...APPROACHING ENERGY
ALOFT...AND AN ADVANCING SURFACE WARM FRONT.
AS WARMER AND MORE MOIST AIR SURGES INTO THE REGION TONIGHT...THE
HEAVY RAIN THREAT WILL INCREASE ACCORDINGLY. PWAT VALUES ARE
EXPECTED TO EXCEED 1.5 INCHES AFTER MIDNIGHT...AND CONTINUE TO RISE
ON WEDNESDAY...PEAKING JUST BELOW 2 INCHES BY EARLY AFTERNOON.
HIRES MODELS AND THE LATEST OPERATIONAL GFS/NAM SHOW THE POTENTIAL
FOR WIDESPREAD 2-5 INCHES WITH THE LEAST EXPECTED WEST OF THE BLUE
RIDGE AND THE MOST SOMEWHERE BETWEEN THE BLUE RIDGE AND I-95
CORRIDOR.
FLASH FLOOD WATCH REMAINS IN EFFECT AREA WIDE...AND RIVER FLOOD
WATCHES ARE IN EFFECT AT EIGHT FORECAST POINTS...INCLUDING THE
RECENTLY ADDED WATCH THIS EVE FOR LITTLE FALLS. CONFIDENCE WAS NOT
HIGH ENOUGH TO UPGRADE ANY OF THE WATCHES TO WARNINGS THIS FAR
PRIOR TO THE HEAVY RAINFALL. CONTINUE TO MONITOR THE LATEST
FORECASTS AND DISCUSSIONS...AND MONITOR FOR POTENTIAL WARNINGS.
&&
.TIDES/COASTAL FLOODING...
TIDAL DEPARTURES GENERALLY AROUND 1.5 TO 1.75 FT ABV ASTRONOMICAL
TIDES. THIS IS A JUMP UPWARD FROM THE EVENING HOURS...FUELED BY A
STDY SE WIND NEAR THE MOUTH OF THE CHESAPEAKE BAY. BASED ON THOSE
ANOMALIES...THE WESTERN SHORE OF THE BAY FROM BALT SWD AS WELL AS
THE LOWER POTOMAC NEAR ST GEORGE ISLAND WL BE AT THE CUSP OF MDT
FLOODING WITHT HE INCOMING HIGH TIDE. HAVE UPGRADED TO WARNING
THERE...AND LEFT THE REST AS IS. SW DC MAY BE CLOSE ALSO...AND WL
ADDRESS THAT IN THE NXT CPL HOURS /BEFORE DAWN/.
THE COASTAL FLOOD WATCH REMAINS IN EFFECT FROM WEDNESDAY AFTERNOON
THROUGH THROUGH THURSDAY MORNING FOR THE WESTERN SHORE OF THE
CHESAPEAKE BAY. THE PM TIDE IS THE LOWER ASTRONOMICALLY...BUT AM
NOT SURE IF THAT WL BE BALANCED BY INCREASING DEPARTURES. THE THU
MRNG TIDE CYCLE LOOKING TO BE THE HIGHEST OF THEM ALL.
A COLD FRONT CROSSES THE WATERS EARLY THU AND MAYBE PUSHES SOME
OF THE EXCESS WATER OUT OF THE ESTUARY. MINOR TIDAL FLOODING IS
EXPECTED FOR LOCATIONS ALONG THE UPPER TIDAL POTOMAC RIVER.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR DCZ001.
COASTAL FLOOD ADVISORY FROM 7 AM THIS MORNING TO NOON EDT
TODAY FOR DCZ001.
MD...FLASH FLOOD WATCH THROUGH THIS EVENING FOR MDZ003-004-501-502.
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MDZ005>007-009>011-
013-014-016>018.
COASTAL FLOOD WARNING UNTIL 1 PM EDT THIS AFTERNOON FOR MDZ011-
014-017-018.
COASTAL FLOOD WATCH FROM 1 PM EDT THIS AFTERNOON THROUGH
THURSDAY MORNING FOR MDZ007-011-014-017-018.
COASTAL FLOOD ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR
MDZ007.
VA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR VAZ025>031-036>040-
042-050-051-501-503-504.
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR VAZ052>057-502.
COASTAL FLOOD ADVISORY FROM 7 AM THIS MORNING TO NOON EDT
TODAY FOR VAZ053-054.
WV...FLASH FLOOD WATCH THROUGH THIS EVENING FOR WVZ050>053-055-
501>506.
MARINE...GALE WARNING UNTIL 6 AM EDT THURSDAY FOR ANZ532>534-537-
540>543.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ530-531-
535-536-538-539.
&&
$$
SYNOPSIS...HTS/JRK/BJL
NEAR TERM...JRK/BJL
SHORT TERM...DFH
LONG TERM...CEB
AVIATION...JRK/BJL/CEB/DFH
MARINE...JRK/BJL/CEB/DFH
HYDROLOGY...JRK/JCE
TIDES/COASTAL FLOODING...HTS/KCS
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1228 AM CDT WED APR 30 2014
.UPDATE...
ISSUED AT 1226 AM CDT WED APR 30 2014
UPDATED FOR AVIATION DISCUSSION BELOW.
UPDATE ISSUED AT 430 PM CDT TUE APR 29 2014
HAVE INCREASED SNOWFALL AMOUNTS THIS EVENING FOR THE TWIN PORTS
AND I-35 CORRIDOR. THE SNOW WILL BE LOCALIZED WITH SOME AREAS
SEEING LITTLE OR NO SNOW. HOWEVER...AREAS THAT DO SEE SNOW CAN
EXPECT 1-3" OF ACCUMULATION. SNOWFALL SPOTTERS ARE REPORTING
LOCALIZED HEAVY SNOW IN THE SNOW SHOWERS CURRENTLY OVER FAR
NORTHWEST WISCONSIN.
&&
.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 311 PM CDT TUE APR 29 2014
AT 300PM/2000Z...THERE WAS A LARGE LOW PRESSURE SYSTEM CENTERED
OVER EASTERN IOWA. HIGH PRESSURE WAS CENTERED OVER HUDSON BAY AND
QUEBEC. MUCH OF THE UPPER MIDWEST HAD RAIN AND SNOW SHOWERS AND
CLOUDY SKIES...WHILE THE NORTHERN PLAINS OF NW MINNESOTA AND NORTH
DAKOTA HAD CLEAR SKIES DUE TO THE INFLUENCE OF THE CANADIAN HIGH
PRESSURE. THERE WAS LIGHT TO MODERATE RAIN AND SNOW IN NW
WISCONSIN ASSOCIATED WITH THE LOW PRESSURE SYSTEM...AND WHICH WAS
GRADUALLY MOVING WEST AND NORTHWARD INTO THE CENTRAL FORECAST
AREA. THE BAND OF RAIN AND SNOW WAS ALSO ASSOCIATED WITH A
SHORTWAVE OVER WESTERN WISCONSIN SHIFTING TO THE NORTH AND WEST.
TEMPERATURES RANGED FROM THE LOW 30S IN NW WISCONSIN AND THE
UPPER 30S TO NEAR 50 DEGREES IN NE MINNESOTA.
THE CONCERN FOR THIS EVENING IS THE CURRENT MAIN BAND OF SNOW
SHOWERS IN NW WISCONSIN...AND HOW IT WILL AFFECT OTHER AREAS AS IT
MOVES WEST. IN THIS MAIN BAND OF MAXIMIZED OMEGA...SNOW IS
FALLING FROM ALOFT AND AT FALLING AS RAIN AT FIRST ALONG ITS
WESTERN LEADING EDGE. THEN THE TEMPERATURES NEAR THE SURFACE ARE
FALLING...AND ALLOWING THE PCPN TO SWITCH FROM RAIN TO SNOW NEAR
THE SURFACE. THE RELATIVELY WARM SURFACE IS MAKING IT TAKE SOME
TIME FOR SNOW TO ACCUMULATE...ESPECIALLY ON THE ROADS. WE HAVE
GOTTEN PLENTY OF REPORTS THOUGH THAT THE SNOW IS EVENTUALLY
ACCUMULATING ON GRASS AND ROOFS AND SUCH...AND CREATING SLUSHY
ROADS. VISIBILITY IS ALSO LOW AT TIMES DURING THE HEAVIER SNOW
RATES. THIS BAND WILL BE SHIFTING INTO AREAS OF THE CENTRAL AND
WESTERN FORECAST AREA THAT HAVE GOTTEN MUCH WARMER THAN NW
WISCONSIN GOT TODAY DUE TO NW WISCONSIN BEING WET AND CLOUDY FOR
MOST OF TODAY...WHILE WESTERN AREAS REMAINED DRY. THEREFORE...I
THINK IT WILL TAKE EXTRA TIME FOR THE PCPN TO SWITCH TO SNOW AND
FOR THE SNOW TO ACCUMULATE AS IT MOVES INTO THE WESTERN FORECAST
AREA. HOWEVER...AREAS COULD SEE UP TO A COUPLE INCHES OF SNOW
ACCUMULATION. IF THE SNOW LINGERS LONG ENOUGH AND/OR FALLS HEAVY
ENOUGH...ACCUMULATION COULD BE GREATER. AT THIS POINT WE HAVE BEEN
COVERING THIS SYSTEM WITH NOWCASTS DUE TO SNOW ACCUMULATION BEING
LESS THAN 3 INCHES...BUT WE MIGHT NEED TO RECONSIDER A WINTER
WEATHER ADVISORY IF SNOWFALL AMOUNTS APPEAR TO BE MORE THAN
FORECAST.
THE HRRR HAS BEEN DOING FAIRLY WELL DEPICTING THE TIMING OF THIS
BAND OF RAIN AND SNOW...SO I LEANED ON THAT MODEL FOR MY HOURLY
FORECAST THROUGH TONIGHT.
IT APPEARS THAT HUMIDITY IN THE ICE NUCLEATION LAYER COULD
DRY UP FOR A TIME TONIGHT IN THE WAKE OF THE BAND OF PCPN...SO
PCPN COULD SWITCH FROM SNOW/RAIN TO DRIZZLE FOR A PERIOD.
HOWEVER...IT THEN APPEARS SATURATION IN THE ICE NUCLEATION LAYER
WILL INCREASE AGAIN LATE TONIGHT. THIS IS WHY I HAVE BOTH RAIN AND
SNOW IN THE FORECAST FOR MOST THE FORECAST AREA ALL THE WAY
THROUGH TONIGHT. SURFACE TEMPERATURES ARE FORECAST TO PRIMARILY BE
JUST ABOVE FREEZING TONIGHT...SO I DID NOT PUT ANY FREEZING RAIN
IN THE FORECAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 311 PM CDT TUE APR 29 2014
TIS THE SEASON...FOR ATMOSPHERIC BLOCKS THAT IS...AND THE LARGE
CLOSED LOW OVER EASTERN IOWA IS TAKING CENTER STAGE. MDLS
DISPLAY STRONG CONSENSUS THAT MID LVL FEATURE WILL MEANDER INTO
SRN MN BY WED MORNING...AND THEN SLIDE EAST TOWARDS NRN IL BY THUR
MORNING. AS THIS OCCURS...A LARGE DEEP AND MOIST CIRCULATION WILL
ENCOMPASS THE ENTIRE REGION. AS EXPRESSED IN PREVIOUS DISCUSSIONS
THIS TYPE OF SYNOPTIC PATTERN WILL GUARANTEE HIGH AMOUNTS OF CLOUD
COVER HOWEVER THE SKILL LEVEL FOR POPS IS RATHER LIMITED.
CHARACTERISTICALLY THIS TYPE OF SYSTEM WOULD EXHIBIT HIGHER POPS
DIURNALLY WITH DAYTIME CONVECTION AND MIN POPS IN THE OVERNIGHT.
HOWEVER GIVEN THE EXTENSIVE CLOUD CANOPY THE AMOUNT OF DIURNAL
INSTABILITY WILL BE LIMITED. THIS LEAVES THE POTENTIAL FOR PRECIP
TO BE MORE ALIGNED WITH MIGRATORY SHORTWAVE FEATURES ALOFT. WILL
USE A HIGH POP/LOW QPF THEME THROUGH MID DAY THURSDAY. MDLS LIFT
SYSTEM EAST FRIDAY AS AN UPSTREAM KICKER ARRIVES EMBEDDED WITHIN
THE NW FLOW. WHILE THIS SYSTEM WILL ACT TO IMPROVE THE WEATHER
INITIALLY IT WILL EVENTUALLY AMPLIFY OVERHEAD SATURDAY WHICH MAY
LEAD TO AN INCREASE IN POPS FOR THE NRN TIER OF ZONES. THERE DOES
APPEAR TO BE A MDT TO HIGH PROBABILITY THAT FAIR WX MAY RETURN BY
SUNDAY AND CONTINUE INTO NEXT WEEK BASED ON THE MID LVL FLOW WHICH
ESTABLISHES RIDGING ALOFT OVER THE NRN PLAINS. TEMPS BLO LIMO
THROUGH THE WEEK...AND THEN AIMING FOR NEAR SEASONAL VALUES EARLY
NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1226 AM CDT WED APR 30 2014
A SLOW MOVING LOW PRESSURE SYSTEM WILL ROTATE OVER WISCONSIN THROUGH
THURSDAY....CONTINUING TO LIFT WAVES OF RAIN/DRIZZLE OVER THE
FORECAST AREA. EXPECT MVFR/IFR CEILING TO PREVAIL WITH PERIODS OF
RAIN/DRIZZLE. THE RAIN MAY MIX WITH SNOW AT TIMES OVERNIGHT. THE
ABUNDANT MOISTURE MAY PRODUCE LIGHT FOG/BR OVERNIGHT...MAINLY IN
THE4 KHYR AND KDLH AREAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 36 44 35 49 / 70 60 30 30
INL 36 49 34 50 / 70 50 30 30
BRD 38 48 35 53 / 70 40 20 30
HYR 37 47 37 52 / 70 60 30 30
ASX 35 43 36 50 / 70 60 40 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR
LSZ140>147.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...CANNON
AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
337 AM EDT WED APR 30 2014
.SYNOPSIS...
A COLD FRONT ACROSS WESTERN TENNESSEE AND MISSISSIPPI WILL MOVE
ACROSS THE EASTERN CAROLINAS THURSDAY NIGHT. WAVES OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED...WITH A GROWING RISK OF SEVERE WEATHER
WEDNESDAY. HIGH PRESSURE WILL BRING DRY WEATHER FOR THE WEEKEND...
ALTHOUGH A FRONT MAY APPROACH THE AREA FROM THE NORTH EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3:30 AM WEDNESDAY...LOOKS LIKE THE PERSISTENT WARM FRONT
DRAPED ACROSS OUR NORTHERN FRINGES HAS FINALLY BEGUN LIFTING
NORTH...MOVING US MORE FIRMLY IN THE WARM SECTOR OF THE APPROACHING
FRONTAL SYSTEM. MEANWHILE...ISOLATED WEAK CONVECTION HAS BEEN
BREAKING OUT ACROSS OUR INLAND COUNTIES. A MUCH MORE EXTENSIVE AREA
OF CONVECTION OVER GEORGIA BEING SUSTAINED BY AN UPPER DISTURBANCE
IS GRADUALLY MOVING IN THIS DIRECTION...AND THIS MCS WILL LIKELY
AFFECT OUR SOUTHWESTERN COUNTIES LATE THIS MORNING BEFORE FURTHER
SPREADING NORTHEAST...AFFECTING THE REMAINDER OF THE AREA.
THE AIRMASS TODAY AND TONIGHT WILL REMAIN WARM AND MOIST...WITH
DEWPOINTS IN THE UPPER 60S TO EVEN LOWER 70S IN PLACES. ALTHOUGH
CONVECTIVE INDICES ARE GENERALLY FAVORABLE FOR SCATTERED TO
WIDESPREAD CONVECTION...CAPE WILL BE ON THE MODEST SIDE. PLUS...THE
MID LEVELS...AT LEAST THE DAYTIME HOURS...WILL NOT BE AS SATURATED
AS I WOULD LIKE TO SEE FOR CATEGORICAL POPS. THUS WILL LIMIT DAYTIME
POPS TO LIKELY...EXCEPT FOR A STRIP OF CATEGORICAL ACROSS OUR FAR
NORTHWESTERN COUNTIES THIS AFTERNOON AND EVENING. THE BIG DEAL
THOUGH IS THAT SHEAR PROFILES DO LOOK FAVORABLE FOR ORGANIZED STORM
FORMATION...WITH THE POTENTIAL FOR TORNADOES AND LINES OF SEVERE
CONVECTION. BEST POTENTIAL WILL BE AWAY FROM THE COAST...AWAY FROM
THE INFLUENCE OF THE MARINE LAYER...LATE THIS AFTERNOON AND EVENING.
DEEP UPPER LONGWAVE TROUGH OVER CENTRAL CONUS WILL SWING SLOWLY
EASTWARDS...DRIVING A COLD FRONT ACROSS THE FORECAST AREA OVERNIGHT.
LOW LEVEL CONVERGENCE IN ADVANCE OF FRONT WILL CONTINUE THE
POTENTIAL FOR STRONG TO SEVERE CONVECTION INTO AT LEAST THE EVENING
HOURS. FRONT WILL BE POISED TO MOVE OFFSHORE BY AROUND DAYBREAK.
TEMPERATURES WILL REMAIN ABOVE AVERAGE THROUGH THE PERIOD...WITH
HIGHS IN THE LOWER 80S...AND LOWS IN THE MID TO UPPER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...COLD FRONT ASSOCIATED WITH STACKED LOW MOVING
INTO THE GREAT LAKES WILL BE WEST OF THE AREA AS THE PERIOD BEGINS.
ALTHOUGH THE FRONT WILL NOT BE FAR FROM THE AREA IT WILL TAKE A LONG
TIME TO PUSH OFFSHORE...NOT DOING SO UNTIL THU NIGHT AT WHICH POINT
IT ENDS UP STALLING ALONG OR JUST OFF THE COAST. THE ALMOST CUTOFF
NATURE OF THE 5H LOW OVER THE UPPER MID-WEST AND OCCLUDED NATURE OF
THE PARENT LOW TRANSLATE TO SLOW SURFACE FEATURE MOVEMENT. IT ALSO
MEANS THE COLD PUSH BEHIND THE FRONT WILL BE OF LIMITED STRENGTH AND
DURATION. TEMPS ABOVE CLIMO THU/THU NIGHT WILL BE KNOCKED BELOW
CLIMO FOR FRI/FRI NIGHT BUT ONLY BY A FEW DEGREES.
CONVERGENCE ALONG THE FRONT WILL BE WEAK AND ONCE THE NOCTURNAL JET
MIXES OUT THERE WILL BE NO LOW LEVEL JETTING THU AND FLOW WILL BE
UNIDIRECTIONAL. AIRMASS WILL STILL BE UNSTABLE...ESPECIALLY ONCE
TEMPS WARM UP A BIT. HOWEVER DIURNAL HEATING WILL BE TEMPERED BY
CLOUD COVER SO INSTABILITY WILL BE SOMEWHAT LIMITED. THE RESULT
SHOULD BE A DAY WITH WIDESPREAD SHOWERS AND THUNDERSTORMS...BUT WITH
INTENSITY LIKELY TO FALL SHORT OF SEVERE CRITERIA. CAN SEE NO REASON
TO ARGUE WITH INHERITED LIKELY POP THU INTO THU NIGHT.
FRONT WILL REMAIN STALLED OFF THE COAST FRI AND FRI NIGHT WITH DEEP
SOUTHWEST FLOW KEEPING MID LEVELS MOIST. WESTERLY LOW LEVEL FLOW
WILL WORK TO DRY THE LOW LEVEL OUT...SOMETHING READILY APPARENT IN
FORECAST SOUNDINGS. ALTHOUGH THE LOW LEVEL DRY AIR WILL BE
SIGNIFICANT CANNOT RULE OUT ISOLATED SHOWERS. COMBINATION OF DEEP
MID LEVEL MOISTURE AND PVA SPREADING OVER THE AREA DURING THE
AFTERNOON COULD GENERATE SOME WEAK ACTIVITY. BEST PRECIP CHANCES
WILL BE ALONG THE COAST AND HAVE LOW CHC POP AT THE COAST DECREASING
TO SLIGHT CHC POP FARTHER INLAND. ISOLATED SHOWERS MAY LINGER INTO
THE OVERNIGHT...ESPECIALLY ALONG THE COAST WHERE ACTIVITY OVER THE
WATERS COULD BRUSH THE COAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...PERIOD WILL BEGIN WITH MID LEVEL TROUGHING IN
PLACE BUT A TRANSITION TO MID LEVEL RIDGING FOR EARLY NEXT WEEK IS
EXPECTED. MID LEVEL TROUGH AXIS REMAINS WEST OF THE AREA SAT WITH
STALLED FRONT LINGERING JUST OFF THE SOUTHEAST COAST. DEEPEST
MOISTURE WILL REMAIN OFFSHORE INTO SUN BUT WEAKLY DIVERGENT FLOW
ALOFT AND PRESENCE OF A SHORTWAVE OR TWO COULD GENERATE SOME LIGHT
PRECIP ALONG THE IMMEDIATE COAST AND OVER THE WATERS.
SOUTHERN STREAM SHORTWAVE MOVES ACROSS THE SOUTHEAST LATE
SAT...MOVING OFF THE GA/SC COAST SAT NIGHT. THIS FEATURE WILL HELP
PUSH THE STALLED FRONT OUT TO SEA EARLY NEXT WEEK AND BRING AN
EXTENDED PERIOD OF DRY WEATHER. THERE WILL BE A WEAK BACKDOOR COLD
FRONT THAT DROPS SOUTH AND STALLS IN THE AREA MON INTO TUE. FRONT
WILL PASS DRY AS IT LACKS DEEP MOISTURE AND LOW LEVEL CONVERGENCE IS
QUITE WEAK. BUILDING MID LEVEL RIDGE AND SURFACE HIGH EXPANDING
NORTH WILL PUSH THE FRONT BACK NORTH TUE NIGHT.
WEAK COLD ADVECTION AND LINGERING CLOUD COVER WILL KEEP HIGHS A
LITTLE BELOW CLIMO SAT...ESPECIALLY ALONG THE COAST. SUNSHINE ON SUN
WILL PUSH TEMPS NEAR TO SLIGHTLY ABOVE CLIMO. SIMILAR TEMPERATES
ARE EXPECTED MON/TUE DESPITE PRESENCE OF WEAK FRONT.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...CONVECTION HAS ALL BUT ENDED. THE HRRR MODEL DOES SHOW
ISOLATED SHOWERS OVERNIGHT BUT THAT`S ABOUT IT. MOIST SOUTH
SOUTHWEST FLOW OVERNIGHT IS EXPECTED TO BRING IN IFR STRATUS AT ALL
SITES...BEGINNING WITH THE MYRTLES.
WEDNESDAY...IFR WILL LIFT TO MVFR WITH CONVECTION INCREASING
THROUGHOUT THE DAY. EVEN WITH THE CLOUD COVER...SHOULD SEE CAPES
AROUND 1000 J/KG WITH PRECIPITABLE WATER APPROACHING TWO INCHES. SHOWERS
WILL BE FAIRLY WIDESPREAD BY MIDDAY INLAND...SPREADING TO THE COAST
BY 18Z OR SO. THE GFS SEEMS TO BE WETTER AND FASTER THAN THE NAM.
THE MARINE LAYER MAY BE A DETERRENT FOR CONVECTION AT THE
COAST...HOWEVER THE SOUTHWEST FLOW MAY BE STRONG ENOUGH TO PIN THE
RESULTANT.
EXTENDED OUTLOOK...SCATTERED AFTERNOON/EVENING SHOWERS AND
THUNDERSTORMS POSSIBLE THROUGH THURSDAY. CHANCE FOR SHOWERS FRIDAY
NIGHT INTO SATURDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3:30 AM WEDNESDAY...GRADUALLY INCREASING SOUTHERLY FLOW IN
ADVANCE OF A COLD FRONT WILL BUILD SEAS INTO THE 4 TO 6 FT RANGE BY
THIS AFTERNOON. WINDS WILL INCREASE FROM PRESENT 10 TO 15 KTS TO 15
TO 20 KTS LATER THIS MORNING. SMALL CRAFT ADVISORY WILL REMAIN IN
EFFECT THROUGH THE NEAR TERM.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...STRONG SOUTHWEST FLOW WILL CONTINUE THU AHEAD
OF A SLOW MOVING COLD FRONT. SCA HEADLINES WILL LIKELY NEED TO BE
CARRIED INTO THU AFTERNOON AND POSSIBLY EARLY EVENING FOR SOME
ZONES. ALTHOUGH HIGHEST SPEEDS ARE LIKELY TO BE AROUND 20 KT
PROLONGED PERIOD OF ENHANCED SOUTHWEST FLOW WILL BUILD SEAS OVER 6
FT. FRONT MOVES OFFSHORE THU NIGHT WITH WINDS SHIFTING TO NORTHWEST
AND SPEEDS DROPPING TO 10 TO 15 KT BY FRI MORNING. GRADIENT REMAINS
SOMEWHAT PINCHED AND WEST TO SOUTHWEST FLOW WILL STAY IN THE 10 TO
15 KT RANGE THROUGH THE END OF THE PERIOD. SEAS 4 TO 7 FT THU WILL
DROP TO 3 TO 5 FT THU NIGHT WITH THE PASSAGE OF THE COLD FRONT. SEAS
CONTINUE TO SUBSIDE FRI DROPPING FROM 2 TO 4 FT AT THE START OF THE
PERIOD 2 TO 3 FT BY SAT MORNING.
.LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...FRONT STALLED EAST OF THE WATERS SAT WILL
MOVE FARTHER OFFSHORE SUN. WEAK GRADIENT WILL BE IN PLACE DURING THE
PERIOD KEEPING WEST TO SOUTHWEST FLOW AROUND 10 KT FOR MUCH OF THE
PERIOD. SEAS WILL BE AROUND 2 FT THROUGH THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 6 PM EDT
THURSDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...REK
SHORT TERM...III
LONG TERM...III
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
150 AM EDT WED APR 30 2014
.SYNOPSIS...
A COLD FRONT ACROSS WESTERN TENNESSEE AND MISSISSIPPI WILL MOVE
ACROSS THE EASTERN CAROLINAS THURSDAY NIGHT. WAVES OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED...WITH A GROWING RISK OF SEVERE WEATHER
WEDNESDAY. HIGH PRESSURE WILL BRING DRY WEATHER FOR THE WEEKEND...
ALTHOUGH A FRONT MAY APPROACH THE AREA FROM THE NORTH EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1:45 AM WEDNESDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. RELEVANT PORTION OF PREVIOUS DISCUSSION...AS
MODIFIED AND UPDATED...FROM 730 PM FOLLOWS:
NOW THAT THE CURRENT CONVECTIVE ACTIVITY HAS PUSHED NORTH WE
SHOULD BE ENTERING A LULL IN PRECIP CHANCES. PRECIPITATION
CHANCES WILL INCREASE FROM WEST TO EAST OVERNIGHT AS AN UPPER
LEVEL DISTURBANCE NOW NEAR THE AL/GA BORDER MOVES INTO THE
AREA...ACCOMPANIED BY A STREAM OF DEEPER MOISTURE IN THE 850-700
MB LAYER. JET STREAM DYNAMICS ARE MARGINAL NOW WITH A 200/300 MB
JET STREAK ACROSS KY/OH. AS THIS JET STREAK MOVES FARTHER AWAY
FROM THE CAROLINAS OVERNIGHT THIS SHOULD TAKE AWAY WHAT LITTLE
INFLUENCE THE JET STREAK IS PROVIDING.
WITH SUCH A WARM AND SOUPY AIRMASS OUT THERE LOWS SHOULD REMAIN IN
THE 70-72 RANGE ACROSS THE BOARD TONIGHT...15-18 DEGREES ABOVE
NORMAL FOR THIS DATE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...AN INTENSE LOW PRESSURE SYSTEM ACROSS THE
GREAT LAKES WILL SLOWLY MOVE EASTWARD THROUGH WED EVENTUALLY
LIFTING NORTH THROUGH THURSDAY ACROSS THE GREAT LAKES. THIS LOW
WILL DRAG A COLD FRONT EAST MARCHING THROUGH THE CAROLINAS WED
INTO THURS FINALLY REACHING THE COAST THURS NIGHT INTO EARLY FRI.
A VERY MOIST AND INCREASINGLY UNSTABLE ATMOSPHERE AHEAD OF THIS
FRONT WILL INCREASE THE CHC OF STRONG TO SEVERE CONVECTION THROUGH
WED INTO THURS. LOOKS LIKE THE THE GREATEST POTENTIAL FOR STRONG
TO SEVERE STORM STORMS WILL BE ACROSS THE INTERIOR CAROLINAS
INITIALLY BUT WILL EASE CLOSER TO THE COAST OVERNIGHT WED INTO
THURS. AS TEMPS INCREASE CLOSE TO 80 AND DEWPOINT TEMPS REMAIN
CLOSE TO 70...CAPE VALUES WILL INCREASE THROUGH WED UP ABOVE 2000
J/KG. AS LLJ INCREASES UP TO 40 TO 50 KTS PUMPING IN PLENTY OF
MOISTURE THROUGH WED INTO THURS WITH PCP WATER VALUES INCREASING
UP ABOVE 1.5 INCHES. EXPECT MORE DISCREET CELLS DEVELOPING IN THIS
MOIST AND UNSTABLE AIR MASS WELL AHEAD OF FRONT WITH POTENTIAL FOR
LARGE HAIL AND RISK OF TORNADOES. JUST AHEAD OF COLD FRONT EXPECT
MOISTURE TO POOL IN SQUALL LINE WITH PCP WATER VALUES REACHING UP
TO 1.9 INCHES...WELL ABOVE NORMAL. EXPECTED PRIMARY THREAT TO BE
DAMAGING WINDS IN MORE ORGANIZED SQUALL LINE.
ONGOING CONVECTION FROM PREVIOUS DAY AND CLOUDS MAY LIMIT CONVECTIVE
POTENTIAL ON THURS ALONG WITH THE FACT THAT THE LINE OF STORMS MAY
MOVE THROUGH EARLIER IN THE DAY. THIS WILL ALSO KEEP TEMPS LOWER
OVERALL REACHING INTO 70S. THEREFORE KEPT ENHANCED WORDING FOR
SEVERE POTENTIAL INLAND WED MAKING ITS WAY TO THE COAST LATER ON WED
AND THEN MORE GENERAL THUNDERSTORMS WITH HEAVY RAIN FOR THURS.
GREATEST POTENTIAL WILL BE CLOSER TO THE COAST ON THURS WHERE TEMPS
AND GREATEST MOISTURE WILL BE.
THE MID TO UPPER TROUGH WILL REMAIN WEST OF AREA AND THEREFORE WILL
NOT SEE GREAT PUSH FOR FRONT TO MOVE MUCH PAST THE COAST BY END OF
PERIOD. EXPECT DRY AIR TO MAKE ITS WAY IN AS WINDS VEER AROUND TO
THE W-SW THROUGH THE LOWER LEVELS LATE THURS INTO THURS NIGHT AND
WILL BEGIN CLEARING AND DIMINISHING POPS INTO THURS NIGHT.
CAA LATE THURS INTO EARLY FRI WILL ALLOW TEMPS TO DROP INTO THE 50S
OVERNIGHT THURS WITH DEWPOINT TEMPS MAKING THEIR WAY DOWN FROM THE
60S TO NEAR 70 WED INTO THURS TO 50 TO 55 BY FRI MORNING.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...AXIS OF A POSITIVELY-TILTED MID/UPPER TROUGH
WILL EXTEND FROM SOUTHERN ILLINOIS TO WEST TEXAS EARLY FRIDAY...AND
TRANSITION TO THE EASTERN SEABOARD BY SATURDAY NIGHT. A SLOWING AND
WEAKENING COLD FRONT LOOKS TO BE JUST OFFSHORE BY DAYBREAK FRIDAY
LEAVING A WEAK SURFACE PRESSURE FIELD IN ITS WAKE. ALTHOUGH THE
COLUMN WILL DRY FROM THE BOTTOM UP FRIDAY INTO SATURDAY...TIME-
HEIGHT CROSS SECTIONS INDICATE ENOUGH MOISTURE AND LIFT AVAILABLE TO
WARRANT AT LEAST A SMALL POP UNTIL THE 500 MB TROUGH AXIS PUSHES OFF
THE COAST. A DEEP LAYER OF NORTHWEST FLOW WILL BECOME ESTABLISHED
ABOVE 925 MB SUNDAY. STRONG LOW PRESSURE WILL SWEEP ACROSS THE GREAT
LAKES AND NORTHEAST CONUS SUNDAY NIGHT INTO MONDAY...WITH THE
ASSOCIATED COLD FRONT SLOWLY DROPPING SOUTH ACROSS NORTH CAROLINA.
THE FRONT IS EXPECTED TO STALL SOMEWHERE ACROSS THE CAROLINAS MONDAY
AS IT BEGINS TO PARALLEL THE UPPER FLOW.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...CONVECTION HAS ALL BUT ENDED. THE HRRR MODEL DOES SHOW
ISOLATED SHOWERS OVERNIGHT BUT THAT`S ABOUT IT. MOIST SOUTH
SOUTHWEST FLOW OVERNIGHT IS EXPECTED TO BRING IN IFR STRATUS AT ALL
SITES...BEGINNING WITH THE MYRTLES.
WEDNESDAY...IFR WILL LIFT TO MVFR WITH CONVECTION INCREASING
THROUGHOUT THE DAY. EVEN WITH THE CLOUD COVER...SHOULD SEE CAPES
AROUND 1000 J/KG WITH PRECIPITABLE WATER APPROACHING TWO INCHES. SHOWERS
WILL BE FAIRLY WIDESPREAD BY MIDDAY INLAND...SPREADING TO THE COAST
BY 18Z OR SO. THE GFS SEEMS TO BE WETTER AND FASTER THAN THE NAM.
THE MARINE LAYER MAY BE A DETERRENT FOR CONVECTION AT THE
COAST...HOWEVER THE SOUTHWEST FLOW MAY BE STRONG ENOUGH TO PIN THE
RESULTANT.
EXTENDED OUTLOOK...SCATTERED AFTERNOON/EVENING SHOWERS AND
THUNDERSTORMS POSSIBLE THROUGH THURSDAY. CHANCE FOR SHOWERS FRIDAY
NIGHT INTO SATURDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:45 AM WEDNESDAY...SOUTHERLY WINDS OF 10 TO 15 KTS OVER THE
WATERS EARLY THIS MORNING WITH SEAS IN THE 3 TO 4 FT RANGE. SMALL
CRAFT ADVISORY STILL SET FOR 8 AM AS SEAS CONTINUE TO BUILD.
PREVIOUS DISCUSSION FROM 730 PM FOLLOWS:
A COLD FRONT OVER WESTERN TENNESSEE AND MISSISSIPPI WILL MOVE EAST
OVER THE NEXT SEVERAL DAYS...FINALLY REACHING THE CAROLINA COAST
LATE THURSDAY. UNTIL THEN...MODERATE SOUTH WINDS WILL CONTINUE WITH
GRADUALLY BUILDING SEAS. BASED ON LATEST WIND FORECASTS AND WAVE
OBSERVATIONS FROM BUOYS I HAVE DELAYED THE ONSET OF SMALL CRAFT
ADVISORY CONDITIONS BY 5 HOURS...UNTIL 8 AM WEDNESDAY MORNING. WINDS
TONIGHT SHOULD AVERAGE 12-15 KNOTS FROM THE SOUTH WITH VERY LITTLE
GUSTINESS GIVEN THE STABLE THERMAL PROFILES AS WARM AIR RIDES OVER
THE RELATIVELY COLD OCEAN SURFACE. SEVERAL CLUSTERS OF THUNDERSTORMS
OVER INTERIOR EASTERN NORTH CAROLINA WILL PASS WELL NORTH OF OUR
COASTAL WATERS THIS EVENING. THERE IS A SMALL POTENTIAL OF SHOWERS
OR THUNDERSTORMS DEVELOPING LATE TONIGHT...BUT MORE LIKELY WEDNESDAY.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...SMALL CRAFT CONDITIONS WILL PERSIST THROUGH
MUCH OF THE PERIOD. STRONG AND GUSTY SOUTHERLY WINDS AHEAD OF A
SLOWLY APPROACHING COLD FRONT WILL INCREASE UP TO 15 TO 20 KTS EARLY
WED. WINDS MAY REACH ABOVE 20 KTS AS GRADIENT TIGHTENS AHEAD OF COLD
FRONT WED NIGHT INTO EARLY THURS...ESPECIALLY IN THE OUTER WATERS.
THE WINDS WILL VEER ON THURS BECOMING SW THROUGH LATE AFTN AND
WESTERLY BY MIDNIGHT INTO THE EARLY MORNING HOURS. AS THE WINDS VEER
AROUND BECOMING MORE OFFSHORE...SEAS WILL LOWER IN THE NEAR SHORE
WATERS BUT WILL REMAIN HIGH OFF SHORE A LITTLE LONGER INTO THE EARLY
MORNING HOURS.
THE STRONG SOUTHERLY PUSH AHEAD OF THE FRONT WILL KEEP SEAS UP
BETWEEN 4 TO 6 FT MOST OF THE PERIOD WITH OUTER WATERS REACHING
AROUND 7 FT WED NIGHT INTO THURS.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...A WEAK COLD FRONT IS EXPECTED TO BE JUST OFF
THE COAST FRIDAY MORNING. SCATTERED SHOWER/TSTM ACTIVITY IS EXPECTED
ALONG THE FRONT...AS WELL AS THE POTENTIAL FOR SOME SHOWER ACTIVITY
LINGERING INTO SATURDAY UNTIL THE MID-LEVEL TROUGH AXIS SHIFTS EAST
OF THE WATERS. THE PRESSURE FIELD BEHIND THE FRONT WILL BE WEAK...SO
ALTHOUGH A SHIFT TO NORTHWEST WINDS WILL OCCUR FRIDAY MORNING...
WINDS WILL BACK AROUND TO THE WEST-SOUTHWEST BY EARLY AFTERNOON. THE
GRADIENT ACROSS THE WATERS WILL REMAIN RATHER MODEST SATURDAY AND
SUNDAY BETWEEN A WEAK SURFACE HIGH CENTERED OVER THE NORTHERN GULF
OF MEXICO AND LOW PRESSURE SKIRTING ACROSS THE GREAT LAKES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 6 PM EDT
THURSDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...RJD
SHORT TERM...RGZ
LONG TERM...CRM
AVIATION...DL
MARINE...RJD/RGZ/CRM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
113 AM CDT WED APR 30 2014
.UPDATE...
ISSUED AT 112 AM CDT WED APR 30 2014
NO SIGNIFICANT CHANGES REQUIRED WITH THIS UPDATE AS THE INHERITED
FORECAST IS ON TRACK. CEILINGS CONTINUE TO LOWER ACROSS WESTERN
NORTH DAKOTA...GENERALLY ALONG AND WEST OF HIGHWAY 85. MAINTAINED
THE MENTION OF FOG ACROSS THE WEST WITH THE STRATUS BUILD DOWN.
UPDATE ISSUED AT 935 PM CDT TUE APR 29 2014
MAIN ADJUSTMENT TO THE FORECAST WAS TO INCREASE AREAL COVERAGE OF
PATCHY FOG IN THE WEST. THE 30.00Z NAM SHOWS INCREASING BOUNDARY
LAYER RELATIVE HUMIDITY VALUES ACROSS WESTERN NORTH DAKOTA...WITH
VALUES APPROACHING 100 PERCENT OVERNIGHT. THE LATEST RAP AND HRRR
ALSO SUGGEST THERE COULD BE VISIBILITY RESTRICTIONS IN PARTS OF
THE WEST...SO FELT CONFIDENT ENOUGH TO EXPAND FOG TO THE NORTHWEST
DESPITE THE WIND.
UPDATE ISSUED AT 651 PM CDT TUE APR 29 2014
MADE ONLY MINOR ADJUSTMENTS TO THE FORECAST TO CAPTURE THE LATEST
CLOUD TRENDS. THE 29.18Z NAM STILL SUPPORTS FOG DEVELOPMENT IN THE
WEST LATE TONIGHT / EARLY WEDNESDAY MORNING THOUGH IT MAY NEED TO
BE EXPANDED FARTHER NORTHWEST. WILL CONSIDER THAT FOR THE NEXT
UPDATE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 338 PM CDT TUE APR 29 2014
WEDGE OF SUBSIDING DRY AIR ON CLEARING CLOUDS ACROSS MOST OF THE
REGION. SNOW JUST ABOUT OVER SOUTHWEST AS PER BOWMAN RADAR. GUSTY
NORTHWEST WINDS ARE MIXING WELL AND TEMPS HAVE WARMED INTO THE
LOWER 50S CENTRAL AND EAST...WHILE THE SNOW COVERED AREAS
SOUTHWEST ARE IN THE MIDDLE 30S. ADDED SOME PATCHY FOG WEST OVER
SNOW COVERED AREAS WEST TONIGHT...ALTHOUGH WINDS WILL BE ELEVATED
ABOVE GENERAL FOG CRITERIA...THE ABUNDANT COOLED AND MOIST
BOUNDARY LAYER MAY BE ENOUGH TO OVERCOME THE MIXING. OTHERWISE
MOSTLY CLEAR THIS EVENING WITH SOME INCREASING CLOUDS AS THE UPPER
LOW DUMBELLS BACK INTO THE EASTERN DAKOTAS AND BRING SOME LIGHT
RAIN AFTER SUNRISE WEDNESDAY IN THE JAMES RIVER VALLEY. BUFKIT
SOUNDINGS SUGGEST JUST SUB ADVISORY WINDS OF 25 TO 35 MPH
WEDNESDAY AS THE SURFACE FLOW WRAPS UP OVER THE GREAT LAKES.
HIGHS SHOULD BE IN THE LOWER 50S CENTRAL AND EAST AND IN THE 40S
OVER THE SNOW COVERED AREAS WEDNESDAY. MOST OF THE SNOW MAY BE
GONE AFTER WEDNESDAY AS SAT PICS SHOW PRETTY RAPID MELT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 338 PM CDT TUE APR 29 2014
AN ACTIVE AND COOL WEATHER PATTERN WILL PERSIST FOR MUCH OF THE
LONG TERM PERIOD.
LARGE UPPER LEVEL LOW PRESSURE CENTERED OVER THE WESTERN GREAT
LAKES/UPPER MISSISSIPPI VALLEY REGION WILL CONTINUE TO SPIN
THROUGH WEDNESDAY NIGHT...THEN WILL FINALLY LIFT NORTHEAST
THURSDAY INTO FRIDAY INTO SOUTHEASTERN CANADA. FOR THE NORTHERN
PLAINS...CYCLONIC FLOW ALOFT WILL TRANSITION TO A NORTHWESTERLY
FLOW ALOFT THURSDAY ONCE THE LOW LIFTS OUT...THEN QUASI-ZONAL LATE
IN THE WEEKEND INTO THE EARLY PORTIONS OF THE FOLLOWING WORK WEEK
AS BROAD RIDGING DEVELOPS ACROSS THE UNITED STATES.
THE UPPER LOW WOBBLES/RETROGRADES SLIGHTLY WEST ON WEDNESDAY...
ALLOWING FOR WRAP AROUND MOISTURE TO ROTATE THROUGH THE EASTERN
DAKOTAS. CHANCES FOR PRECIPITATION ACROSS EASTERN NORTH DAKOTA
DECREASE WEDNESDAY NIGHT INTO THURSDAY AS THE UPPER LOW ONCE
AGAIN MOVES FARTHER EAST.
DRY CONDITIONS OVERNIGHT WEDNESDAY THROUGH THURSDAY MORNING AS A
SUBTLE S/WV RIDGE PASSES THROUGH THE AREA.
AS OUR FLOW ALOFT BECOMES MORE NORTHWEST THURSDAY
AFTERNOON...SEVERAL EMBEDDED WAVES WILL TRACK FROM NORTHWEST TO
SOUTHEAST THROUGH THE NORTHERN PLAINS LATER IN THE DAY
THURSDAY...THROUGH THURSDAY NIGHT...AND INTO FRIDAY...EACH
GENERATING A CHANCE OF RAIN OR SNOW (DEPENDING ON THE THERMAL
PROFILE AND SFC TEMPERATURES). AT THIS TIME MUCH OF THE
PRECIPITATION IS EXPECTED TO FALL AS RAIN.
UPPER LEVEL JET MOVES OVER THE REGION THIS COMING WEEKEND...AND
WILL RESULT IN A CONTINUED UNSETTLED PATTERN THAT LOOKS TO
CONTINUE INTO EARLY NEXT WEEK...WITH CHANCES FOR PRECIPITATION
EACH DAY. WITH THE DEVELOPMENT OF THE BROAD RIDGE...TEMPERATURES
SHOULD MODERATE A BIT...WITH HIGHS IN THE 50S/LOW 60S VERSUS MID
40S AND MID 50S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 112 AM CDT WED APR 30 2014
MVFR STRATUS AND MVFR/IFR FOG IS POSSIBLE AT KISN AND KDIK LATE
TONIGHT INTO WEDNESDAY MORNING. MVFR STRATUS AND RAIN IS EXPECTED AT
KJMS BY 14 UTC AS LOWERED CEILINGS AND PRECIPITATION MOVE IN FROM
NORTHWEST MINNESOTA. OTHERWISE...VFR CONDITIONS ARE FORECAST
ELSEWHERE FOR THE 06 UTC TAF CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...WAA
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
520 AM EDT WED APR 30 2014
.SYNOPSIS...
A WET AND STORMY PATTERN WILL PERSIST ACROSS THE AREA THROUGH
WEDNESDAY. THE PATTERN WILL BEGIN TO CHANGE BY THE END OF THE WORK
WEEK WITH COOLER AND DRIER HIGH PRESSURE MOVING OVER THE REGION AND
REMAINING IN PLACE OVER THE WEEKEND. BEYOND THAT...BROAD UPPER
RIDGING WILL PREVAIL THROUGH MID WEEK LEADING TO MODERATING
TEMPERATURES AND LOW PRECIPITATION CHANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 500 AM EDT...MADE SOME SIGFNT CHANGES TO LOWER THE POP/QPF
GRIDS OVER THE NEXT 3 HRS. THE WEDGE BNDRY HAS ERODED FOR THE MOST
PART...LEAVING LITTLE FORCING FOR CONTINUED OR WIDESPREAD CONVEC.
THERE IS STILL AN ACTIVE BNDRY NEAR CLT WITH STORMS PRODUCING UP TO
AN INCH OF RAIN IN THE PAST HR OR TWO. NO IMMEDIATE FLOOD
THREATS...BUT THE CLT ARE WILL NEED TO BE MONITORED CLOSELY THIS
AFTERNOON FOR POSSIBLE HEAVY RAINFALL PRODUCING FLOODING CONDS.
PRECIPITATION WITH SOME THUNDER CONTINUES TO DEVELOP ALONG A WEDGE
BNDRY BISECTING THE CWFA. THESE CELLS ARE REMAINING FAIRLY WEAK AND
SHALLOW WITH AN H7 INVERSION KEEPING THINGS IN CHECK. PRECIP AMOUNTS
THE PAST FEW HRS HAS REMAINED LOW END WITH THE HIGHER RATES UP TO
0.5 IN/HR ACROSS THE ERN ZONES WHERE THE FLOW IS ALSO ALIGNING ALONG
THE RIDGE BNDRY AND ALLOWING SOME TRAINING.
WITH THE GOM COASTAL CONVECTION SIGFNTLY LIMITING THE AMOUNT OF
MOISTURE FLUX TO THE CWFA...QPF AMOUNTS WERE AGAIN ADJ DOWN USING A
CONSENSUS OF MOS/DYN MODELS. THE HRRR CONTINUES TO INITIATE AND
CAPTURE THE LOWER QPF SCENARIO MUCH BETTER THAN THE HIRES NAM AND
WRF MODELS...SO IT WAS BLENDED WITH MORE WEIGHT WITH OFFICIAL. THE
FLASH FLOOD WATCH WILL BE CONTINUED AS AFTERNOON CONVECTION SHOULD
BE RATHER STOUT RAIN PRODUCERS POSSIBLY PRODUCING LOCALIZED
STREAM/RIVER FLOODING AS LLVL MOISTURE POOLS ALONG AND AHEAD OF AN
APPROACHING COLD FRONT. THE THREAT OF SEVERE TSTMS IS ALSO LOOKING
GOOD IF ENOUGH INSTABILITY CAN BE REALIZED. MODEL SOUNDINGS SHOW
SBCAPE VALUES ACROSS THE NON/MTNS OF AROUND 1200 J/KG WITH VERY GOOD
E/SHEAR AROUND 55 KTS AND H92/H5 CROSSOVER WINDS INDICATING THE
POTENTIAL FOR ROTATING LONG LIVED STORMS.
THE FRONT SHOULD CROSS EAST OF THE AREA OVERNIGHT AND ALLOW A DEEP
DRYING MIX ACROSS THE WRN ZONES. HOWEVER...SCT/ISOL SHOWERS WILL
LIKELY LINGER THROUGH DAYBREAK OVER THE ERN PART OF THE CWFA. THE
ULVL DYNAMICS WILL REMAIN WELL NE OF THE AREA ASSOCIATED WITH THE
OCCLUDED LOW...SO NOT MUCH OF A WIND SHIFT WILL ACCOMPANY THE FROPA
OUTSIDE THE MTNS. MAX AND MIN TEMPS WILL BE RIGHT AROUND SEASONAL
LEVELS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 200 AM EDT WEDNESDAY...ROTATING UPPER VORTEX WILL EJECT TO THE
NORTHEAST ALLOWING THE UPPER FLOW TO OPEN UP IN THE FORM A BROAD
LONGWAVE POSITIVELY TILTED TROF. AT THE SURFACE...FRONTAL BOUNDARY
WILL HAVE PUSHED EAST INTO THE MIDLANDS/LOWCOUNTRY OF SC AND THE
COASTAL PLAINS OF NC. MODELS CONTINUE TO HINT AT SLOWING DOWN OF
THE FRONT AS IT APPROACHES THE COAST LATER IN THE DAY THURSDAY
POTENTIALLY STALLING JUST OFFSHORE INTO FRIDAY. FORECAST WILL
FEATURE CHANCE POPS TAPERING DOWN THROUGH MID/LATE THURSDAY MORNING
SOUTH OF INTERSTATE 85...WITH SLIGHT CHANCE POPS ACROSS THE CENTRAL
AND NORTHERN MOUNTAINS OF WESTERN NC DUE TO WEAK UPSLOPE POTENTIAL.
BEYOND THAT POPS WILL TAPER DOWN BELOW MENTIONABLE LEVELS FOR THE
OVERNIGHT INTO FRIDAY. DECIDED TO CONTINUE WITH PREVIOUS FORECAST
OF SLIGHT CHANCE POPS SOUTH OF INTERSTATE 85 ON FRIDAY AFTERNOON AS
RIGHT REAR ENTRANCE REGION OF A 110KT JET MAX WILL PROVIDE
SUBSTANTIAL LIFT TO SUPPORT LIGHT SHOWERS IF A WEAK SURFACE WAVE
DEVELOPS ALONG THE STALLED FRONTAL BOUNDARY AS GUIDANCE SUGGESTS.
LASTLY...POPS WILL DROP QUICKLY INTO FRIDAY EVENING AS THE UPPER
TROF AXIS AND ABOVE MENTIONED JET MAX ADVECT NORTHEAST ALLOWING FOR
HEIGHTS TO RISE ACROSS THE SOUTHEAST IN ADDITION TO BUILDING HIGH
PRESSURE AT THE SURFACE. TEMPERATURES THROUGH THE SHORT TERM WILL
COOL GRADUALLY WITH BELOW NORMAL HIGHS FORECAST FOR BOTH THURSDAY
AND FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 230 AM EDT WEDNESDAY...THE MEDIUM RANGE PERIOD INITIALIZES
SATURDAY MORNING WITH A WEAK UPPER WAVE PASSING THROUGH THE NORTHERN
GULF AND SURFACE HIGH PRESSURE BUILDING ACROSS THE SOUTHEAST LEADING
TO A DRY PERIOD. SURFACE CYCLOGENESIS OCCURRING OVER SOUTHERN
QUEBEC WILL LIKELY SPREAD A WEAK COLD FRONT ACROSS THE GREAT LAKES
AND OHIO VALLEY REGIONS ON SUNDAY...ALL THE WHILE REMAINING NORTH OF
THE FORECAST AREA. HEIGHTS WILL RISE ACROSS THE SOUTHEAST THROUGH
MIDWEEK AS AN UPPER TROF DIGS OUT WEST AND AN UPPER RIDGE SLIDES
THROUGH THE EASTERN CONUS LEADING TO CONTINUED DRY WEATHER.
TEMPERATURES THROUGH THE MEDIUM RANGE PERIOD WILL INITIALIZE AT
BELOW NORMAL LEVELS FOR SATURDAY...BEFORE GRADUALLY WARMING TO ABOVE
NORMAL NEAR THE END OF THE PERIOD AS THE ABOVE MENTIONED SURFACE
HIGH SLIDES EAST ALLOWING A WARM FRONT TO SPREAD ACROSS THE SOUTHERN
APPALACHIANS.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...PRECIP AND ANY ISOL DEEP CONVECTION IS HAVING A HARD TIME
MAKING IT TO THE TERMINAL THIS MORNING AS THE SFC BNDRY REMAINS TO
THE SOUTH AND UPPER SUBS IS KEEPING CONVEC SHALLOW TO THE WEST. HARD
TO TELL IF THE PRECIP SHIELD WILL HOLD TOGETHER AS IT APPROACHES THE
FIELD...SO WENT WITH A TEMPO -SHRA WITH PREVAILING -SHRA AFT 12Z.
LOW END IFR CIGS AND MVFR VSBYS SHOULD HOLD RATHER STEADY STATE
OVERNIGHT AND WITH SHOWERS MAY IMPROVE PERIODICALLY THROUGH
DAYBREAK. WINDS WILL BECOME DEFINED S/LY DURING THE DAY WITH GUSTS
IN THE AFTERNOON. HAVE KEPT THUNDER MENTION BEGINNING EARLY
AFTERNOON AS INSTABILITY INCREASES AND STATIONARY FRONT MOVES NORTH
AS A WARM FRONT DURING THE DAY.
ELSEWHERE...EXPECT IFR RANGE CIGS AND MVFR/IFR VSBYS THIS MORNING TO
BECOME MIXED AT TIMES WITH VFR CONDS ASSOCIATED WITH SCOURING -SHRA.
A TRANSITION FROM SHRA TO SCT/NUM TSTMS IS IN STORE THIS
AFTERNOON...WITH SOME ISOL THUNDER THIS MORNING POSSIBLE. WINDS WILL
BECOME ALIGNED AND REMAIN S/LY EARLY THIS AFTERNOON WITH MODERATE
GUSTS DEVELOPING IN RESPONSE TO FRONTAL PRESSURE FALLS.
OUTLOOK...DRYING FROM THE WEST IS EXPECTED FROM WED NIGHT THROUGH
THE WEEKEND.
CONFIDENCE TABLE...
09-15Z 15-21Z 21-03Z 03-09Z
KCLT MED 76% MED 79% MED 78% HIGH 84%
KGSP MED 79% MED 76% MED 73% HIGH 94%
KAVL HIGH 100% MED 78% MED 79% HIGH 86%
KHKY HIGH 94% MED 79% HIGH 88% HIGH 87%
KGMU HIGH 87% HIGH 84% HIGH 86% HIGH 95%
KAND HIGH 92% HIGH 85% HIGH 87% HIGH 86%
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 THROUGH THIS EVENING FOR GAZ010-017-018-026-
028-029.
NC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR NCZ033-035>037-
048>053-056>059-062>065-068>072-082-501>510.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ001>014-019.
&&
$$
SYNOPSIS...CDG/JPT
NEAR TERM...SBK
SHORT TERM...CDG
LONG TERM...CDG
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
331 AM EDT WED APR 30 2014
.SYNOPSIS...
A WET AND STORMY PATTERN WILL PERSIST ACROSS THE AREA THROUGH
WEDNESDAY. THE PATTERN WILL BEGIN TO CHANGE BY THE END OF THE WORK
WEEK WITH COOLER AND DRIER HIGH PRESSURE MOVING OVER THE REGION AND
REMAINING IN PLACE OVER THE WEEKEND. BEYOND THAT...BROAD UPPER
RIDGING WILL PREVAIL THROUGH MID WEEK LEADING TO MODERATING
TEMPERATURES AND LOW PRECIPITATION CHANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
PRECIPITATION WITH SOME THUNDER CONTINUES TO DEVELOP ALONG A WEDGE
BNDRY BISECTING THE CWFA. THESE CELLS ARE REMAINING FAIRLY WEAK AND
SHALLOW WITH AN H7 INVERSION KEEPING THINGS IN CHECK. PRECIP AMOUNTS
THE PAST FEW HRS HAS REMAINED LOW END WITH THE HIGHER RATES UP TO
0.5 IN/HR ACROSS THE ERN ZONES WHERE THE FLOW IS ALSO ALIGNING ALONG
THE RIDGE BNDRY AND ALLOWING SOME TRAINING.
WITH THE GOM COASTAL CONVECTION SIGFNTLY LIMITING THE AMOUNT OF
MOISTURE FLUX TO THE CWFA...QPF AMOUNTS WERE AGAIN ADJ DOWN USING A
CONSENSUS OF MOS/DYN MODELS. THE HRRR CONTINUES TO INITIATE AND
CAPTURE THE LOWER QPF SCENARIO MUCH BETTER THAN THE HIRES NAM AND
WRF MODELS...SO IT WAS BLENDED WITH MORE WEIGHT WITH OFFICIAL. THE
FLASH FLOOD WATCH WILL BE CONTINUED AS AFTERNOON CONVECTION SHOULD
BE RATHER STOUT RAIN PRODUCERS POSSIBLY PRODUCING LOCALIZED
STREAM/RIVER FLOODING AS LLVL MOISTURE POOLS ALONG AND AHEAD OF AN
APPROACHING COLD FRONT. THE THREAT OF SEVERE TSTMS IS ALSO LOOKING
GOOD IF ENOUGH INSTABILITY CAN BE REALIZED. MODEL SOUNDINGS SHOW
SBCAPE VALUES ACROSS THE NON/MTNS OF AROUND 1200 J/KG WITH VERY GOOD
E/SHEAR AROUND 55 KTS AND H92/H5 CROSSOVER WINDS INDICATING THE
POTENTIAL FOR ROTATING LONG LIVED STORMS.
THE FRONT SHOULD CROSS EAST OF THE AREA OVERNIGHT AND ALLOW A DEEP
DRYING MIX ACROSS THE WRN ZONES. HOWEVER...SCT/ISOL SHOWERS WILL
LIKELY LINGER THROUGH DAYBREAK OVER THE ERN PART OF THE CWFA. THE
ULVL DYNAMICS WILL REMAIN WELL NE OF THE AREA ASSOCIATED WITH THE
OCCLUDED LOW...SO NOT MUCH OF A WIND SHIFT WILL ACCOMPANY THE FROPA
OUTSIDE THE MTNS. MAX AND MIN TEMPS WILL BE RIGHT AROUND SEASONAL
LEVELS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 200 AM EDT WEDNESDAY...ROTATING UPPER VORTEX WILL EJECT TO THE
NORTHEAST ALLOWING THE UPPER FLOW TO OPEN UP IN THE FORM A BROAD
LONGWAVE POSITIVELY TILTED TROF. AT THE SURFACE...FRONTAL BOUNDARY
WILL HAVE PUSHED EAST INTO THE MIDLANDS/LOWCOUNTRY OF SC AND THE
COASTAL PLAINS OF NC. MODELS CONTINUE TO HINT AT SLOWING DOWN OF
THE FRONT AS IT APPROACHES THE COAST LATER IN THE DAY THURSDAY
POTENTIALLY STALLING JUST OFFSHORE INTO FRIDAY. FORECAST WILL
FEATURE CHANCE POPS TAPERING DOWN THROUGH MID/LATE THURSDAY MORNING
SOUTH OF INTERSTATE 85...WITH SLIGHT CHANCE POPS ACROSS THE CENTRAL
AND NORTHERN MOUNTAINS OF WESTERN NC DUE TO WEAK UPSLOPE POTENTIAL.
BEYOND THAT POPS WILL TAPER DOWN BELOW MENTIONABLE LEVELS FOR THE
OVERNIGHT INTO FRIDAY. DECIDED TO CONTINUE WITH PREVIOUS FORECAST
OF SLIGHT CHANCE POPS SOUTH OF INTERSTATE 85 ON FRIDAY AFTERNOON AS
RIGHT REAR ENTRANCE REGION OF A 110KT JET MAX WILL PROVIDE
SUBSTANTIAL LIFT TO SUPPORT LIGHT SHOWERS IF A WEAK SURFACE WAVE
DEVELOPS ALONG THE STALLED FRONTAL BOUNDARY AS GUIDANCE SUGGESTS.
LASTLY...POPS WILL DROP QUICKLY INTO FRIDAY EVENING AS THE UPPER
TROF AXIS AND ABOVE MENTIONED JET MAX ADVECT NORTHEAST ALLOWING FOR
HEIGHTS TO RISE ACROSS THE SOUTHEAST IN ADDITION TO BUILDING HIGH
PRESSURE AT THE SURFACE. TEMPERATURES THROUGH THE SHORT TERM WILL
COOL GRADUALLY WITH BELOW NORMAL HIGHS FORECAST FOR BOTH THURSDAY
AND FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 230 AM EDT WEDNESDAY...THE MEDIUM RANGE PERIOD INITIALIZES
SATURDAY MORNING WITH A WEAK UPPER WAVE PASSING THROUGH THE NORTHERN
GULF AND SURFACE HIGH PRESSURE BUILDING ACROSS THE SOUTHEAST LEADING
TO A DRY PERIOD. SURFACE CYCLOGENESIS OCCURRING OVER SOUTHERN
QUEBEC WILL LIKELY SPREAD A WEAK COLD FRONT ACROSS THE GREAT LAKES
AND OHIO VALLEY REGIONS ON SUNDAY...ALL THE WHILE REMAINING NORTH OF
THE FORECAST AREA. HEIGHTS WILL RISE ACROSS THE SOUTHEAST THROUGH
MIDWEEK AS AN UPPER TROF DIGS OUT WEST AND AN UPPER RIDGE SLIDES
THROUGH THE EASTERN CONUS LEADING TO CONTINUED DRY WEATHER.
TEMPERATURES THROUGH THE MEDIUM RANGE PERIOD WILL INITIALIZE AT
BELOW NORMAL LEVELS FOR SATURDAY...BEFORE GRADUALLY WARMING TO ABOVE
NORMAL NEAR THE END OF THE PERIOD AS THE ABOVE MENTIONED SURFACE
HIGH SLIDES EAST ALLOWING A WARM FRONT TO SPREAD ACROSS THE SOUTHERN
APPALACHIANS.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...PRECIP AND ANY ISOL DEEP CONVECTION IS HAVING A HARD TIME
MAKING IT TO THE TERMINAL THIS MORNING AS THE SFC BNDRY REMAINS TO
THE SOUTH AND UPPER SUBS IS KEEPING CONVEC SHALLOW TO THE WEST. HARD
TO TELL IF THE PRECIP SHIELD WILL HOLD TOGETHER AS IT APPROACHES THE
FIELD...SO WENT WITH A TEMPO -SHRA WITH PREVAILING -SHRA AFT 12Z.
LOW END IFR CIGS AND MVFR VSBYS SHOULD HOLD RATHER STEADY STATE
OVERNIGHT AND WITH SHOWERS MAY IMPROVE PERIODICALLY THROUGH
DAYBREAK. WINDS WILL BECOME DEFINED S/LY DURING THE DAY WITH GUSTS
IN THE AFTERNOON. HAVE KEPT THUNDER MENTION BEGINNING EARLY
AFTERNOON AS INSTABILITY INCREASES AND STATIONARY FRONT MOVES NORTH
AS A WARM FRONT DURING THE DAY.
ELSEWHERE...EXPECT IFR RANGE CIGS AND MVFR/IFR VSBYS THIS MORNING TO
BECOME MIXED AT TIMES WITH VFR CONDS ASSOCIATED WITH SCOURING -SHRA.
A TRANSITION FROM SHRA TO SCT/NUM TSTMS IS IN STORE THIS
AFTERNOON...WITH SOME ISOL THUNDER THIS MORNING POSSIBLE. WINDS WILL
BECOME ALIGNED AND REMAIN S/LY EARLY THIS AFTERNOON WITH MODERATE
GUSTS DEVELOPING IN RESPONSE TO FRONTAL PRESSURE FALLS.
OUTLOOK...DRYING FROM THE WEST IS EXPECTED FROM WED NIGHT THROUGH
THE WEEKEND.
CONFIDENCE TABLE...
07-13Z 13-19Z 19-01Z 01-07Z
KCLT MED 76% MED 75% HIGH 87% HIGH 86%
KGSP MED 78% MED 67% HIGH 88% HIGH 91%
KAVL HIGH 95% HIGH 89% HIGH 81% HIGH 91%
KHKY HIGH 93% MED 77% HIGH 93% HIGH 85%
KGMU HIGH 84% HIGH 89% HIGH 87% HIGH 91%
KAND HIGH 82% HIGH 99% HIGH 89% HIGH 86%
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 THROUGH THIS EVENING FOR GAZ010-017-018-026-
028-029.
NC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR NCZ033-035>037-
048>053-056>059-062>065-068>072-082-501>510.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ001>014-019.
&&
$$
SYNOPSIS...CDG/JPT
NEAR TERM...SBK
SHORT TERM...CDG
LONG TERM...CDG
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
115 AM EDT WED APR 30 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT SLOWLY NORTH OF THE AREA BY EARLY
WEDNESDAY AFTERNOON. A LARGE AND COMPLEX STORM SYSTEM LOCATED OVER
THE CENTRAL UNITED STATES WILL MOVE SLOWLY EAST TO THE COAST BY
THURSDAY NIGHT. THIS SYSTEM WILL PROVIDE SEVERAL ROUNDS OF SHOWERS
AND THUNDERSTORMS...SOME WITH VERY HEAVY RAIN AND A SLIGHT RISK OF
SEVERE WEATHER.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 935 PM EDT TUESDAY...
RADAR CONTINUE STAYING QUIET THIS EVENING OVER OUR CWA. GETTING A
FEW SHOWERS ALONG THE BLUE RIDGE NORTH OF
BLACKSBURG/FLOYD/ROANOKE. DENSE FOG ALSO CREATING TRAVEL ISSUES
ALONG THE HIGHER ELEVATIONS AS WEDGE KEEPS LOW CLOUDS LOCKED IN
PLACE.
00Z RNK SOUNDING SHOWING THE DEPTH OF THE WEDGE TO BE 2000-2200
FEET. SAME GOES FOR THE GSO SOUNDING.
LOOP OF SFC ANALYSIS ACTUALLY SHOWING WEDGE NOT BUDGING...WITH
HIGH PRESSURE NOSING IN MORE OVER THE NEW ENGLAND COAST.
LATEST MODELS SEEM OVERDONE THIS EVENING ON RAINFALL FOR US SO
KEPT POPS LOW. HOWEVER...THE LOW LEVEL FLOW APPEARS TO BE TURNING
MORE SE OVERNIGHT SO KEEPING HIGHER POPS AROUND LATE...ESPECIALLY
OVER THE PIEDMONT/FOOTHILLS. UNTIL THEN SHOULD BE MAINLY LIGHT
RAIN/DRIZZLE/FOG...WITH SHOWERS BECOMING HEAVIER TOWARD DAWN.
RAN TEMPS COOLER EARLY ON WITH SLOW MODERATION TOWARD DAWN WHEN
HEAVIER RAINS MOVE IN BRINGING SOME WARMER AIR ALOFT DOWN.
CONFIDENCE IS LOW ON THE MODELS BREAKING THE WEDGE BY DAWN...AND
LATEST RAP MODEL SHOWING MORE OF IT ERODING BY MIDDAY
WEDNESDAY...WHICH SEEMS PLAUSIBLE.
NO CHANGES TO ONGOING FLASH FLOOD WATCHES OR FORECAST RAINFALL
AMOUNTS. DENSE FOG COVERED BY SPS. SEVERE THREAT OVERNIGHT IS LOW.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AS OF 330 PM EDT TUESDAY...
THE HIGH PRESSURE WEDGE BANKED AGAINST THE EASTERN FACE OF THE
APPALACHIANS WILL BE IN THE PROCESS OF ERODING OUT OF THE REGION BY
SUNRISE WEDNESDAY...AS A WARM FRONT LIFTS ACROSS OUR AREA...ALLOWING
WINDS TO SHIFT SOUTHERLY.
THE MAIN CONCERN TO START THE DAY WILL BE AREAS OF HEAVY RAIN
DEVELOPING ALONG AND EAST OF THE BLUE RIDGE AS WAVES OF ENERGY RIDE
IN FROM THE SOUTHWEST. RAINFALL FROM TUESDAY...EXCEEDING 2 INCHES IN
SOME AREAS...WENT A LONG WAY TO HELP SATURATE THE SOIL. EXPECT THAT
NEW THUNDERSTORMS DEVELOPING TUESDAY NIGHT WILL ALSO BE EFFICIENT
RAINFALL PRODUCERS...AND LOCALIZED FLASH FLOODING MAY RESULT WHERE
ANY OF THE STRONGER THUNDERSTORM CELLS BEGIN TO TRAIN ACROSS THE
SAME LOCATIONS. SOUTHEASTERLY UPSLOPE FLOW WILL LEAD TO LOCALLY
HIGHER RAINFALL AMOUNTS ALONG THE BLUE RIDGE AND OTHER PROMINENT
EAST FACING SLOPES. THE WIDESPREAD RAINFALL WILL ALSO BRING SOME
AREA RIVERS ABOVE FLOOD STAGE DURING THE SECOND HALF OF THE
WORKWEEK.
IN ADDITION TO HEAVY RAINFALL...ALSO SEE THE POTENTIAL FOR STRONG
THUNDERSTORMS DEVELOPING BY LATE MORNING ACROSS THE ENTIRE FORECAST
REGION. STRONG LOW LEVEL SHEAR WILL COMBINE WITH DAYTIME HEATING TO
SUPPORT A FEW STRONG THUNDERSTORMS AREAWIDE DURING LATE MORNING...
WITH THE GREATEST INSTABILITY SHIFTING TO THE PIEDMONT DURING THE
AFTERNOON AND EVENING AS STRONGER WINDS ALOFT MOVE OVER THE AREA.
BELIEVE THE GREATEST THREAT OF SEVERE WEATHER WILL BE IN THE FORM OF
STRONG WINDS...ALTHOUGH HAIL AND ISOLATED TORNADOES WILL ALSO BE
POSSIBLE. THE THREAT OF STRONG STORMS WILL GRADUALLY SHIFT EAST
THROUGH THE EVENING...AND SHOULD EXIT OUR AREA BY AROUND MIDNIGHT
THURSDAY MORNING.
EXPECT ONLY RESIDUAL SHOWER ACTIVITY ON THURSDAY AND FRIDAY...MAINLY
ACROSS THE MOUNTAINS...AS UPPER LEVEL TROUGHING REMAINS SITUATED
ACROSS THE FORECAST REGION. SOUTHWESTERLY FLOW ON THURSDAY WILL
ALLOW AFTERNOON HIGHS TO RANGE FROM THE MID 60S ACROSS THE MOUNTAINS
TO THE MID 70S ACROSS THE SOUTHSIDE. WEST TO NORTHWESTERLY FLOW ON
FRIDAY WILL BRING AFTERNOON HIGHS COOLER ABOUT 5 TO 7 DEGREES.
THURSDAY AND FRIDAY NIGHT LOWS WILL GENERALLY BE IN THE 40S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 100PM EDT TUESDAY...
MODELS IN GENERALLY GOOD AGREEMENT THROUGH THE EXTENDED PERIOD AS THE
ERN TROF SLIDES EAST AND ALLOWS RIDGING WITH NW FLOW TO BECOME
ESTABLISHED OVER OUR AREA. PREVIOUS MODEL RUNS INDICATING A SIGNIFICANT
COLD PUNCH FOR THE WEEKEND HAVE MELLOWED AND WILL TREND THE CURRENT
FORECAST GRIDS WARMER TOWARD THE HPC GUIDANCE.
BEST ENERGY WITH UPPER SHORT WAVE ROTATING AROUND THE BASE OF THE ERN
UPPER TROF SATURDAY IS SOUTH OF THE FA AND MOISTURE IS MORE LIMITED.
THIS WILL HELP SUPPRESS SHOWER ACTIVITY ON SATURDAY AS A WEAK SFC
BOUNDARY PUSHES THROUGH SO WILL BE MUCH LESS AGGRESSIVE WITH POPS.
THERE IS NO BIG PUSH TO THIS BOUNDARY AND IT WILL REMAIN IN THE
NEIGHBORHOOD FOR THE REMAINDER OF THE FORECAST PERIOD. THERE ARE
INDICATIONS OF IMPULSES RIDING ALONG THE FRONT BUT SUBTLE DIFFERENCES
IN PLACEMENT OF FEATURES WILL MAKE A BIG DIFFERENCE IN SENSIBLE
WEATHER. WILL OPT TO CONFINE POPS TO THE TUESDAY PERIOD AS THE BOUNDARY
GETS ENOUGH PUSH TO MOVE THROUGH AS A WARM FRONT.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 100 AM EDT WEDNESDAY...
EXTREMELY POOR FLYING CONDITIONS EXPECTED TO PREVAIL OVERNIGHT
WITH WEDGE IN PLACE SUPPORTING CONTINUATION OF LOW STRATUS CIGS
AND VSBYS IN FOG. LOW CONFIDENCE FORECAST IN INTENSITY/TIMING OF
SHOWERS/STORMS AND ITS EFFECTS ON VSBYS/CIGS BUT HIGH CONFIDENCE
THAT ALL SITES WILL STAY SUB VFR THROUGH MOST OF THIS PERIOD.
BANDS OF MORE SIGNIFICANT SHOWERS WILL AFFECT THE EASTERN
CORRIDOR...MAINLY FROM MTV TO LYH AND POINTS EAST EARLY ON AND
THEN LIKELY CLOSER TO THE BLUE RIDGE INCLUDING ROA/BCB BY
DAYBREAK. UNTIL THE HEAVIER SHOWERS ARRIVE EXPECT LOWER
CIGS/VSBYS AS LOW AS LIFR.
DURING WEDNESDAY WILL SEE MOST OF THE DAY SHIFTING TOWARD SHOWERS
AND STORMS WITH WINDS SHIFTING TOWARD THE SOUTHEAST TO SOUTHWEST
AND THE WEDGE BREAKING. COLD FRONTAL BOUNDARY WILL NOT REACH
BLF/LWB AT LEAST UNTIL THIS EVENING. THINGS SHOULD DRY OUT TOWARD
LATE THIS AFTERNOON IN THE WEST BUT LOW CONFIDENCE IN JUST HOW
FAST SHOWERS WILL SHIFT EAST. THUS LEFT IN A MORE PESSIMISTIC
SCENARIO IN REGARDS TO EXITING LOWER CIGS AND SHOWERS WHILE
INCLUDING A PERIOD OF VCTS OR PREVAILING TSRA DURING THE AFTERNOON
ESPCLY OUTSIDE THE WEDGE.
AS FOR LOW LVL WIND SHEAR GIVEN SHOWERS IN THE AREA OVERALL WILL
LEAVE IT OUT...BUT EXPECT SOME STRONGER SOUTHERLY WINDS ACROSS THE
REGION ABOVE THE WEDGE OVERNIGHT WITH SE WINDS LIKELY MIXING DOWN
IN BLF AT TIMES OVERNIGHT RESULTING IN GUSTS TO 25-30 KTS.
APPEARS ENOUGH DRYING ALOFT TO PERHAPS SEE IMPROVEMENT TO VFR
ACROSS THE EAST LATER THURSDAY INTO FRIDAY WITH MVFR LIKELY
LINGERING AT TIMES ACROSS THE SE WEST VA LOCATIONS INTO FRIDAY. AN
UPPER LEVEL TROUGH OF LOW PRESSURE WILL CROSS THE TENNESSEE
VALLEY ON SATURDAY FOLLOWED BY WEAK HIGH PRESSURE INTO SUNDAY.
HOWEVER WESTERLY FLOW MAY STILL INDUCE SOME UPSLOPE MVFR CIGS AND
PERHAPS ISOLATED -SHRA ACROSS THE SE WEST VA SITES DURING
SATURDAY.
&&
.HYDROLOGY...
AS OF 950 PM EDT TUESDAY...
NO CHANGES TO THE RIVER FORECASTS...STILL EXPECTING ENOUGH QPF TO
BRING PORTIONS OF THE LOWER ROANOKE AND DAN TO GO INTO MODERATE
FLOOD IN A COUPLE OF DAYS. HOWEVER...THIS RAINFALL WILL IS LIMITED
THIS EVENING AND WILL HAVE TO COME AS THE WARM FRONT LIFTS NORTH
WEDNESDAY MORNING FOLLOWED BY THE COLD FRONT WEDNESDAY AFTERNOON
AND EVENING. STILL MAINLY CONCERNED WITH FLASH FLOOD THREAT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR VAZ007-009>020-
022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>006-018>020.
WV...FLASH FLOOD WATCH THROUGH THIS EVENING FOR WVZ042>045.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...AMS/WP
SHORT TERM...NF
LONG TERM...MBS
AVIATION...AMS/JH/WP
HYDROLOGY...AMS/JH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1135 PM CDT TUE APR 29 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 250 PM CDT TUE APR 29 2014
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED STRONG RIDGING ALONG THE U.S. WEST COAST THROUGH
SOUTHWEST CANADA...INTO HUDSON BAY AND NEW ENGLAND...WHILE AN
UPPER LOW WAS CUT OFF OVER THE FORECAST AREA. A DRY SLOT ROTATING
AROUND THE UPPER LOW HAS KICKED THE SHOWERS ALONG AND NORTH OF
I-90 THIS MORNING TO LAKE SUPERIOR AND BACK SOUTHWEST INTO
SOUTHWEST MN. MEANWHILE... UNDER THE UPPER LOW...SHOWERS HAVE
DEVELOPED OVER EASTERN IOWA INTO SOUTHERN WI. UPWARDS OF 250 J/KG
OF MOST UNSTABLE CAPE WAS DEPICTED BY RAP ANALYSIS SUPPORTING THE
SHOWERS. THIS PRECIPITATION WAS ALSO CO-LOCATED WITH A SURFACE LOW
NEW GRANT COUNTY WITH A WARM FRONT EXTENDING EAST TO KENOSHA WI
AND A COLD FRONT EXTENDING SOUTHWESTWARD. COLDER AIR CONTINUES TO
GET GRADUALLY WRAPPED AROUND THE UPPER LOW TOO...WITH THE 12Z MPX
AND INL SOUNDINGS REPORTING 925MB AND 850MB TEMPS BETWEEN 0 AND
-2C. THIS COLDER AIR ALLOWED FOR SOME LIGHT SNOW TO FALL NORTH OF
THE TWIN CITIES THIS MORNING. EVEN SOME SNOW FELL ALONG AND NORTH
OF I-90 THIS MORNING WHERE HEAVIER PRECIPITATION RESULTED IN
DYNAMIC AND EVAPORATIVE COOLING. MOST OF THE SNOW WAS CONFINED TO
GRASSY SURFACES.
VERY LITTLE CHANGE IS FORECAST IN THE UPPER LEVEL PATTERN TONIGHT
AND WEDNESDAY AS THE UPPER LOW BASICALLY MOVES NOWHERE. THIS LEAVES
SHORTWAVES ROTATING AROUND THE UPPER LOW TO IMPACT THE MOVEMENT OF
PRECIPITATION.
FOR TONIGHT...MAIN COLD CONVEYOR BELT AFFECTING MINNESOTA CURRENTLY
LOOKS TO WRAP BACK INTO MUCH OF SOUTHEAST MN AND NORTHEAST IOWA THIS
EVENING...THEN LINGER THROUGH THE OVERNIGHT HOURS WHILE POSSIBLY
BREAKING UP SOME. SOME OF THE COLD CONVEYOR BELT COULD WRAP INTO
SOUTHWEST AND CENTRAL WISCONSIN OVERNIGHT. COMBINATION OF NOCTURNAL
COOLING AND EVAPORATIVE COOLING FROM SOME LOW LEVEL DRY AIR
WRAPPING AROUND THE SURFACE LOW MAY ALLOW THE RAIN TO CHANGE OVER
TO SNOW...AS DEPICTED IN WET-BULB ZERO HEIGHT PROGS DROPPING BELOW
1000 FT. AUSTIN TO CHARLES CITY LOOKS TO HAVE THE HIGHEST
PROBABILITY OF SEEING SNOW ACCUMULATION. HOWEVER...LITTLE
ACCUMULATION IS ANTICIPATED SINCE THE PRECIPITATION IS EXPECTED TO
BE LIGHT AND THE GROUND IS WARM. TO THE EAST...THE SHOWERS ACROSS
SOUTHERN WISCONSIN SHOULD ROTATE INTO CENTRAL AND NORTHWEST
WISCONSIN THROUGH THE NIGHT. A SLIGHTLY COOLER NIGHT IS
LIKELY...PARTICULARLY WEST OF THE MISSISSIPPI RIVER DUE TO THE
COOLER AIR OVER MINNESOTA ROTATING AROUND THE UPPER LOW.
ON WEDNESDAY...THERE IS NO REAL STRONG IDENTIFICATION FEATURE FOR
PRODUCING PRECIPITATION...THOUGH MOST MODELS CONTINUE TO INDICATE
LIGHT SHOWER ACTIVITY AROUND. IT APPEARS MUCH OF THIS SHOWER
ACTIVITY IS LIKELY A INSTABILITY ISSUE...RESULTING FROM COLDER AIR
ALOFT FROM THE UPPER LOW. SCATTERED TO NUMEROUS SHOWERS SEEMS THE
BEST WAY TO DESCRIBE THE PRECIPITATION. 850MB TEMPS RANGING FROM -3C
WEST TO 2C EAST...PLENTY OF CLOUD COVER AND THE SHOWER ACTIVITY WILL
HELP TO KEEP TEMPERATURES DOWN WELL BELOW NORMAL AGAIN. SIDED
TOWARDS THE LOW SIDE OF TEMPERATURE GUIDANCE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 250 PM CDT TUE APR 29 2014
FOR THOSE LOOKING FOR A PATTERN CHANGE...ITS COMING...WITH GOOD
MODEL AGREEMENT FOR A SWITCH TO UPPER LEVEL RIDGING OVER THE
FORECAST AREA EARLY NEXT WEEK. SO THERE WILL BE A GRADUAL MODERATION
TO TEMPERATURES.
THE UPPER LOW LOOKS TO HANG AROUND THE FORECAST AREA WEDNESDAY
NIGHT...BUT THEN A MORE POTENT SHORTWAVE DROPPING DOWN THROUGH SOUTH
CENTRAL CANADA WILL HELP TO KICK THE UPPER LOW OUT TO THE NORTHEAST
ON THURSDAY. BY 00Z FRIDAY...MODELS HAVE THE UPPER LOW CENTERED OVER
LAKE HURON. UNTIL THE UPPER LOW DEPARTS...WE WILL NEED TO CONTEND
WITH SHOWER ACTIVITY ROTATING AROUND IT...ESPECIALLY THROUGH
THURSDAY MORNING. THERE ARE SOME INDICATIONS THAT THE SHOWER
ACTIVITY COULD DIMINISH WEST OF THE MISSISSIPPI RIVER THURSDAY
AFTERNOON FROM THE 29.00Z ECMWF AND 29.12Z CANADIAN...BUT THIS WILL
ALL HINGE ON HOW FAST THE UPPER LOW EJECTS. TEMPERATURES ARE STILL
GOING TO BE COOL THROUGH THURSDAY GIVEN 850MB TEMPS HOLDING BETWEEN -
2C AND 1C AND CLOUDS/SHOWERS. DESPITE THE COOL 850MB TEMPS...PROGGED
WETBULB ZERO HEIGHTS ARE ABOVE 1500 FT AGL...WHICH SHOULD KEEP SNOW
OUT OF THE PICTURE.
THE PLAGUE OF RAIN THAT HAS BEEN OVER THE AREA MAY FINALLY TAKE A
BREAK THURSDAY NIGHT AS SOME WEAK RIDGING BOTH AT THE SURFACE AND
ALOFT MOVES INTO THE AREA. CLOUD CLEARING LOOKS TO BE A BIT
SLOWER...AND POSSIBLY NOT EVEN CLEARING AT ALL IN WISCONSIN. IN
FACT...THE 29.12Z NAM SUGGESTS PERHAPS SOME DRIZZLE LINGERING IN
WISCONSIN AS A RESULT OF THESE CLOUDS HANGING AROUND. ALTHOUGH ITS
IN THE MINORITY OF MODEL GUIDANCE...FELT A 20 PERCENT CHANCE FOR
RAIN IS WARRANTED FOR WISCONSIN.
A WEAK SHORTWAVE IS PROGGED TO DROP SOUTHEAST THROUGH THE AREA ON
FRIDAY...IN THE NORTHWEST FLOW ALOFT BEHIND THE EJECTING UPPER LOW.
29.12Z GFS IS MOST AGGRESSIVE WITH PRODUCING SHOWERS WITH THIS
WAVE...BUT THE ECMWF HINTS AT POTENTIAL PRECIPITATION. KEPT SOME
LOWER PROBABILITIES IN FOR THIS WAVE TO ACCOUNT FOR THESE MODEL
SCENARIOS.
FOR THE WEEKEND...THE MAIN ITEM OF INTEREST IS THE AFOREMENTIONED
POTENT SHORTWAVE OVER SOUTH CENTRAL CANADA PROGGED TO BARREL THROUGH
NORTHERN PORTIONS OF THE UPPER GREAT LAKES SATURDAY AFTERNOON AND
EVENING. THERE ARE SOME MODEL DIFFERENCES ON SPEED AND
LOCATION...BUT ALL HAVE THE SAME IDEA. GIVEN THE POTENT NATURE OF
THE WAVE...PRECIPITATION LOOKS LIKELY...BUT THE DIFFERENCES CREATE
ISSUES WITH GOING TOO HIGH ON CHANCES. FEEL PRETTY CONFIDENT
NORTHERN WISCONSIN WILL SEE RAIN...BUT ELSEWHERE IT IS A BIT
UNCERTAIN. CANNOT RULE OUT SOME THUNDER EITHER WITH THE SHORTWAVE
GIVEN SOME STEEPER MID LEVEL LAPSE RATES PROGGED TO ACCOMPANY IT.
LOOKS LIKE BOTH SATURDAY NIGHT AND SUNDAY WILL THEN END UP DRY DUE
TO SUBSIDENCE BEHIND THE WAVE.
WITH THE RETURN TO UPPER RIDGING EARLY NEXT WEEK...ISENTROPIC LIFT
AND WARM ADVECTION COME INTO THE PICTURE. BOTH THE 29.12Z ECMWF AND
GFS DEPICT SOME LIGHT PRECIPITATION POSSIBLE FOR BOTH MONDAY AND
TUESDAY...ENOUGH TO WARRANT 20-30 PERCENT CHANCES. THE WARM
ADVECTION CLOUDS/PRECIPITATION AND A WARM FRONT SITUATED TO THE
SOUTH CLOSER TO I-70 WILL HOLD TEMPERATURES BACK FROM REACHING
NORMAL. NEVERTHELESS...THE TEMPERATURES EARLY NEXT WEEK LOOK TO BE
MUCH CLOSER TO NORMAL COMPARED TO NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1135 PM CDT TUE APR 29 2014
SURFACE LOW REMAINS OVER SOUTHWEST WISCONSIN LATE THIS EVENING
BETWEEN KDLL AND KMRJ. LOCAL AND REGIONAL RADARS CONTINUE TO SHOW
LIGHT PRECIPITATION ROTATING AROUND THE SURFACE AND UPPER LEVEL
LOWS. SOME BREAKS IN THE RADAR RETURNS BUT STILL SOME LIGHT
DRIZZLE FALLING IN THOSE AREAS. THE 30.00Z NAM INDICATES THE
SURFACE LOW SHOULD MOVE SLOWLY INTO CENTRAL WISCONSIN OVERNIGHT
BEFORE RETROGRADING SOME INTO WESTERN OR SOUTHWESTERN WISCONSIN
WEDNESDAY. THIS WILL CONTINUE TO ALLOW SOME LIGHT PRECIPITATION TO
BE FOUND ACROSS THE AREA THROUGH THE PERIOD. CEILINGS WILL REMAIN
IFR OVERNIGHT...POSSIBLY GOING UP TO MVFR WEDNESDAY AFTERNOON WITH
A LITTLE BIT OF HEATING ONLY TO RETURN TO IFR AGAIN WEDNESDAY
EVENING. THE VISIBILITY SHOULD SHOW A SIMILAR CYCLE WITH MAINLY
MVFR OVERNIGHT IMPROVING ENOUGH FOR VFR WEDNESDAY AFTERNOON AT
KLSE BUT STAYING MVFR AT KRST AND THEN DROPPING BACK TO MVFR
WEDNESDAY EVENING. ENOUGH COLD AIR FOR SOME LIGHT SNOW TONIGHT AT
KRST BUT THAT WILL GO BACK TO LIGHT RAIN OR DRIZZLE WEDNESDAY
MORNING.
&&
.HYDROLOGY...
ISSUED AT 250 PM CDT TUE APR 29 2014
THE MAJORITY OF THE HEAVY RAIN HAS ENDED NOW FOR THE REST OF THE
WEEK...WHICH WILL GREATLY HELP DIMINISH THE CONCERN FOR FLOODING
ON TRIBUTARIES. RUNOFF IS EXPECTED TO RAISE WATER LEVELS ON THE
TRIBUTARIES BUT NO FLOODING IS ANTICIPATED FOR THEM.
MEANWHILE...PLENTIFUL RAIN THAT FELL UPSTREAM OVER CENTRAL
MINNESOTA COMBINED WITH THE RAIN THAT FELL OVER THE FORECAST AREA
WILL ALLOW THE MISSISSIPPI RIVER TO CONTINUE TO RISE. MANY SITES
ALONG THE MISSISSIPPI RIVER SHOULD RISE TO OR ABOVE FLOOD STAGE
OVER THE NEXT WEEK. FLOOD WATCHES AND WARNINGS ARE POSTED ALONG
THE MISSISSIPPI AS A RESULT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLOOD WATCH FROM SATURDAY EVENING THROUGH TUESDAY EVENING FOR
WIZ041-053-054-061.
MN...FLOOD WATCH FROM SATURDAY EVENING THROUGH TUESDAY EVENING FOR
MNZ096.
IA...FLOOD WATCH FROM SATURDAY EVENING THROUGH TUESDAY EVENING FOR
IAZ011-030.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION...04
HYDROLOGY....AJ
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
932 AM EDT WED APR 30 2014
.SYNOPSIS...
THE THREAT OF STORMY WEATHER WILL CONTINUE INTO TONIGHT. A SLOW
MOVING FRONTAL SYSTEM WILL CROSS THE AREA TONIGHT THEN STALL NEAR
THE COAST FOR THURSDAY. COOL AND DRY HIGH PRESSURE WILL BUILD
ACROSS THE REGION FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST RADAR REFLECTIVITY SHOWS MAINLY LIGHT TO MODERATE CONVECTION
MOVING INTO WESTERN PORTIONS OF THE FORECAST AREA FROM GA. A
HEAVIER CELL NOTED IN AIKEN COUNTY MOVING OFF TO THE NORTHEAST.
THIS TREND WILL CONTINUE AS SHOWERS AND THUNDERSTORMS BECOME MORE
WIDESPREAD THIS AFTERNOON. RECENT KCAE 88D VWP ANALYSIS SHOWS
LITTLE DIRECTIONAL SHEAR WITH HEIGHT...SOUTHWEST WIND 25 TO 40 KT
FROM 1K- 5K FT AGL.
ACROSS SOUTHERN AND EASTERN UPPER RIDGE WAS OFF THE EAST COAST
WITH A DEEP/LARGE CYCLONE OVER SOUTHERN MN. THIS PATTERN WILL
FINALLY SHIFT BY THURSDAY AS THE UPPER RIDGE OFF THE COAST MOVES
FARTHER OUT TO SEA ALLOWING THE UPPER LOW TO LIFT NORTHEAST INTO
THE GREAT LAKES REGION.
THE SURFACE COLD FRONT EXTENDING FROM EASTERN KENTUCKY TO THE GULF COAST
WILL SLOWLY MOVE EAST REACHING THE UPSTATE EARLY THIS EVENING. OUR
AREA WILL REMAIN IN THE WARM SECTOR AHEAD OF THE FRONT TODAY. PWAT
IS FORECAST TO INCREASE TO JUST OVER 1.80 INCHES WITH MODERATE TO
STRONG INSTABILITY AS WELL AS STRONG MOISTURE TRANSPORT AND
DIVERGENCE ALOFT. STRONG SHEAR IS FORECAST WITH H8 WINDS 35 TO 45
KNOTS. SPC STILL HAS THE AREA IN A SLIGHT RISK FOR SEVERE WEATHER.
THE SPC WRF AND HRRR MODELS INDICATE THE BEST CHANCE FOR
CONVECTION THROUGH MIDDAY WITH THE PRECIP SHIFTING CLOSER TO THE
COAST THIS AFTERNOON. HOWEVER...CONVECTION ALONG THE GULF COAST
COULD ACT TO DECREASE CONVECTION ACROSS THE MIDLANDS AND CSRA.
POPS RANGE FROM 60 TO 80 PERCENT RANGE TODAY. HIGH CHANCE POPS
LOOK REASONABLE OVERNIGHT...GIVEN THE FRONTAL PASSAGE.
LEANED TOWARD THE WARMER GUIDANCE FOR MAX TEMPS TODAY SINCE
TEMPERATURES WILL START THE DAY IN THE UPPER 60S TO LOWER 70S.
WENT WITH CONSENSUS FOR MILD TEMPERATURES IN THE UPPER 50S WEST TO
MID 60S EAST TONIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
THE FRONTAL BOUNDARY WILL REACH THE COAST THURSDAY MORNING THEN
STALL. ALL MODELS SHOW DEEP MOISTURE SHIFT EAST OF THE FORECAST
AREA EARLY THURSDAY. A STABLE AIR MASS AND COLD AIR ADVECTION WILL
OVERSPREAD THE AREA FROM THE WEST...DIMINISHING THE CHANCE FOR
SHOWERS THURSDAY. KEPT A CHANCE FOR SHOWERS FRIDAY ACROSS MAINLY
THE EASTERN PORTION OF THE CWA AS MOISTURE SURGES NORTHWARD ALONG
THE STALLED FRONT. COOLER TEMPERATURES ARE EXPECTED WITH HIGHS IN
THE 75 TO 80 DEGREE RANGE THURSDAY THEN IN THE LOWER 70S FRIDAY.
OVERNIGHT LOWS SHOULD BE IN THE 50S THURSDAY NIGHTS...UPPER 40S TO
LOWER 50S FRIDAY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE GFS AND ECMWF INDICATE A DRY PATTERN FOR THE WEEKEND THROUGH
EARLY NEXT WEEK. SURFACE RIDGING JUST TO THE SOUTH WILL DOMINATE
WITH THE UPPER PATTERN DE-AMPLIFYING. TEMPERATURES THROUGH THE
MEDIUM RANGE PERIOD WILL BEGIN BELOW NORMAL SATURDAY...BEFORE
GRADUALLY WARMING TO ABOVE NORMAL FOR THE BEGINNING OF NEXT WEEK.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
VFR WITH PERIODS OF MVFR EXPECTED FOR MUCH OF TODAY AS A COLD FRONT
SLOWLY APPROACHES FROM THE WEST.
RADAR TRENDS THIS MORNING INDICATE SOME AREAS OF SHOWERS WITH
ISOLATED THUNDERSTORMS MOVING NORTHEAST FROM THE CSRA INTO THE
MIDLANDS THIS MORNING. MOST TAF SITES REPORTING VFR CONDITIONS WITH
OCCASIONAL MVFR CONDITIONS. AS A COLD FRONT NEAR THE TN VALLEY
SLOWLY MOVES EASTWARD...MOISTURE WILL INCREASE ACROSS THE AREA
THIS MORNING AND INTO THE AFTERNOON HOURS. THE POTENTIAL FOR
CONVECTION WILL INCREASE DURING THE DAY. THUNDER WILL BE POSSIBLE
DURING THE AFTERNOON. WILL USE VCTS FOR ALL TAF STIES DURING THE
AFTERNOON AND INTO THE EVENING HOURS...AS CONFIDENCE IS LOW AS TO
WHERE AND WHEN STRONGER CONVECTION WILL DEVELOP. WINDS HAVE
INCREASED THIS MORNING AND WILL CONTINUE AROUND 12 KNOTS WITH GUSTS
UP TO 20 KNOTS THROUGH THE DAY. WIND SPEEDS WILL DIMINISH SOMEWHAT
BY THIS EVENING.
.EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN SHOWERS AND
THUNDERSTORMS THROUGH THURSDAY NIGHT AS THE FRONTAL SYSTEM SLOWLY
CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
927 AM EDT WED APR 30 2014
.SYNOPSIS...
THE THREAT OF STORMY WEATHER WILL CONTINUE INTO TONIGHT. A SLOW
MOVING FRONTAL SYSTEM WILL CROSS THE AREA TONIGHT THEN STALL NEAR
THE COAST FOR THURSDAY. COOL AND DRY HIGH PRESSURE WILL BUILD
ACROSS THE REGION FOR THE WEEKEND.
&&
.NEAR TERM /1330Z THROUGH TONIGHT/... LATEST RADAR REFLECTIVITY
SHOWS MAINLY LIGHT TO MODERATE CONVECTION MOVING INTO WESTERN
PORTIONS OF THE FORECAST AREA FROM GA. A HEAVIER CELL NOTED IN
AIKEN COUNTY MOVING OFF TO THE NORTHEAST. THIS TREND WILL CONTINUE
AS SHOWERS AND THUNDERSTORMS BECOME MORE WIDESPREAD THIS
AFTERNOON. RECENT KCAE 88D VWP ANALYSIS SHOWS LITTLE DIRECTIONAL
SHEAR WITH HEIGHT...SOUTHWEST WIND 25 TO 40 KT FROM 1K- 5K FT AGL.
ACROSS SOUTHERN AND EASTERN UPPER RIDGE WAS OFF THE EAST COAST
WITH A DEEP/LARGE CYCLONE OVER SOUTHERN MN. THIS PATTERN WILL
FINALLY SHIFT BY THURSDAY AS THE UPPER RIDGE OFF THE COAST MOVES
FARTHER OUT TO SEA ALLOWING THE UPPER LOW TO LIFT NORTHEAST INTO
THE GREAT LAKES REGION.
THE SURFACE COLD FRONT EXTENDING FROM EASTERN KENTUCKY TO THE GULF COAST
WILL SLOWLY MOVE EAST REACHING THE UPSTATE EARLY THIS EVENING. OUR
AREA WILL REMAIN IN THE WARM SECTOR AHEAD OF THE FRONT TODAY. PWAT
IS FORECAST TO INCREASE TO JUST OVER 1.80 INCHES WITH MODERATE TO
STRONG INSTABILITY AS WELL AS STRONG MOISTURE TRANSPORT AND
DIVERGENCE ALOFT. STRONG SHEAR IS FORECAST WITH H8 WINDS 35 TO 45
KNOTS. SPC STILL HAS THE AREA IN A SLIGHT RISK FOR SEVERE WEATHER.
THE SPC WRF AND HRRR MODELS INDICATE THE BEST CHANCE FOR
CONVECTION THROUGH MIDDAY WITH THE PRECIP SHIFTING CLOSER TO THE
COAST THIS AFTERNOON. HOWEVER...CONVECTION ALONG THE GULF COAST
COULD ACT TO DECREASE CONVECTION ACROSS THE MIDLANDS AND CSRA.
POPS RANGE FROM 60 TO 80 PERCENT RANGE TODAY. HIGH CHANCE POPS
LOOK REASONABLE OVERNIGHT...GIVEN THE FRONTAL PASSAGE.
LEANED TOWARD THE WARMER GUIDANCE FOR MAX TEMPS TODAY SINCE
TEMPERATURES WILL START THE DAY IN THE UPPER 60S TO LOWER 70S.
WENT WITH CONSENSUS FOR MILD TEMPERATURES IN THE UPPER 50S WEST TO
MID 60S EAST TONIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
THE FRONTAL BOUNDARY WILL REACH THE COAST THURSDAY MORNING THEN
STALL. ALL MODELS SHOW DEEP MOISTURE SHIFT EAST OF THE FORECAST
AREA EARLY THURSDAY. A STABLE AIR MASS AND COLD AIR ADVECTION WILL
OVERSPREAD THE AREA FROM THE WEST...DIMINISHING THE CHANCE FOR
SHOWERS THURSDAY. KEPT A CHANCE FOR SHOWERS FRIDAY ACROSS MAINLY
THE EASTERN PORTION OF THE CWA AS MOISTURE SURGES NORTHWARD ALONG
THE STALLED FRONT. COOLER TEMPERATURES ARE EXPECTED WITH HIGHS IN
THE 75 TO 80 DEGREE RANGE THURSDAY THEN IN THE LOWER 70S FRIDAY.
OVERNIGHT LOWS SHOULD BE IN THE 50S THURSDAY NIGHTS...UPPER 40S TO
LOWER 50S FRIDAY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE GFS AND ECMWF INDICATE A DRY PATTERN FOR THE WEEKEND THROUGH
EARLY NEXT WEEK. SURFACE RIDGING JUST TO THE SOUTH WILL DOMINATE
WITH THE UPPER PATTERN DE-AMPLIFYING. TEMPERATURES THROUGH THE
MEDIUM RANGE PERIOD WILL BEGIN BELOW NORMAL SATURDAY...BEFORE
GRADUALLY WARMING TO ABOVE NORMAL FOR THE BEGINNING OF NEXT WEEK.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR WITH PERIODS OF MVFR EXPECTED FOR MUCH OF TODAY AS A COLD FRONT
SLOWLY APPROACHES FROM THE WEST.
AN AREA OF MAINLY LIGHT SHOWERS OVER CENTRAL GA CONTINUES TO SLOWLY
MOVE TOWARDS THE CSRA. AS A COLD FRONT NEAR THE TN VALLEY SLOWLY
MOVES EASTWARD...MOISTURE WILL INCREASE ACROSS THE AREA EARLY THIS
MORNING. LATEST RADAR TRENDS THE SHOWERS WILL MOVE INTO THE CSRA
EARLY THIS MORNING AND THEN INTO THE MIDLANDS BY AROUND 12Z-13Z.
WILL ADD MENTION OF -SHRA AT AGS AND DNL...AND VCSH AT THE OTHER TAF
SITES. THE POTENTIAL FOR CONVECTION WILL INCREASE DURING THE DAY.
THUNDER WILL BE POSSIBLE DURING THE AFTERNOON. WILL USE VCTS FOR ALL
TAF STIES DURING THE AFTERNOON AND INTO THE EVENING HOURS. WINDS
WILL BE SOUTHERLY AT AROUND 5 TO 10 KNOTS EARLY THIS MORNING AND
WILL INCREASE LATER THIS MORNING TO AROUND 12 KNOTS WITH GUSTS UP TO
20 KNOTS. WIND SPEEDS WILL DIMINISH SOMEWHAT BY THIS EVENING.
.EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN SHOWERS AND
THUNDERSTORMS THROUGH THURSDAY NIGHT AS THE FRONTAL SYSTEM SLOWLY
CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
646 AM EDT WED APR 30 2014
.SYNOPSIS...
THE THREAT OF STORMY WEATHER WILL CONTINUE INTO TONIGHT. A SLOW
MOVING FRONTAL SYSTEM WILL CROSS THE AREA TONIGHT THEN STALL NEAR
THE COAST FOR THURSDAY. COOL AND DRY HIGH PRESSURE WILL BUILD
ACROSS THE REGION FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN UPPER RIDGE WAS OFF THE EAST COAST WITH A DEEP/LARGE CYCLONE
OVER SOUTHERN MN. THIS PATTERN WILL FINALLY SHIFT BY THURSDAY AS
THE UPPER RIDGE OFF THE COAST MOVES FARTHER OUT TO SEA ALLOWING
THE UPPER LOW TO LIFT NORTHEAST INTO THE GREAT LAKES REGION.
THE SURFACE COLD FRONT EXTENDING FROM CENTRAL KENTUCKY TO THE
LOUISIANA COAST WILL SLOWLY MOVE EAST REACHING THE UPSTATE EARLY
THIS EVENING. OUR AREA WILL REMAIN IN THE WARM SECTOR AHEAD OF THE
FRONT TODAY. PWAT IS FORECAST TO INCREASE TO JUST OVER 1.80
INCHES WITH MODERATE TO STRONG INSTABILITY AS WELL AS STRONG
MOISTURE TRANSPORT AND DIVERGENCE ALOFT. STRONG SHEAR IS FORECAST
WITH H8 WINDS 35 TO 45 KNOTS. SPC STILL HAS THE AREA IN A SLIGHT
RISK FOR SEVERE WEATHER.
CONVECTION WAS INCREASING ACROSS THE MIDLANDS AND CSRA THIS
MORNING. THE SPC WRF AND HRRR MODELS INDICATE THE BEST CHANCE FOR
CONVECTION THROUGH MIDDAY WITH THE PRECIP SHIFTING CLOSER TO THE
COAST THIS AFTERNOON. HOWEVER...CONVECTION ALONG THE GULF COAST
COULD ACT TO DECREASE CONVECTION ACROSS THE MIDLANDS AND CSRA.
POPS RANGE FROM 60 TO 80 PERCENT RANGE TODAY. HIGH CHANCE POPS
LOOK REASONABLE OVERNIGHT...GIVEN THE FRONTAL PASSAGE.
LEANED TOWARD THE WARMER GUIDANCE FOR MAX TEMPS TODAY SINCE
TEMPERATURES WILL START THE DAY IN THE UPPER 60S TO LOWER 70S.
WENT WITH CONSENSUS FOR MILD TEMPERATURES IN THE UPPER 50S WEST TO
MID 60S EAST TONIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
THE FRONTAL BOUNDARY WILL REACH THE COAST THURSDAY MORNING THEN
STALL. ALL MODELS SHOW DEEP MOISTURE SHIFT EAST OF THE FORECAST
AREA EARLY THURSDAY. A STABLE AIR MASS AND COLD AIR ADVECTION WILL
OVERSPREAD THE AREA FROM THE WEST...DIMINISHING THE CHANCE FOR
SHOWERS THURSDAY. KEPT A CHANCE FOR SHOWERS FRIDAY ACROSS MAINLY
THE EASTERN PORTION OF THE CWA AS MOISTURE SURGES NORTHWARD ALONG
THE STALLED FRONT. COOLER TEMPERATURES ARE EXPECTED WITH HIGHS IN
THE 75 TO 80 DEGREE RANGE THURSDAY THEN IN THE LOWER 70S FRIDAY.
OVERNIGHT LOWS SHOULD BE IN THE 50S THURSDAY NIGHTS...UPPER 40S TO
LOWER 50S FRIDAY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE GFS AND ECMWF INDICATE A DRY PATTERN FOR THE WEEKEND THROUGH
EARLY NEXT WEEK. SURFACE RIDGING JUST TO THE SOUTH WILL DOMINATE
WITH THE UPPER PATTERN DE-AMPLIFYING. TEMPERATURES THROUGH THE
MEDIUM RANGE PERIOD WILL BEGIN BELOW NORMAL SATURDAY...BEFORE
GRADUALLY WARMING TO ABOVE NORMAL FOR THE BEGINNING OF NEXT WEEK.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
VFR WITH PERIODS OF MVFR EXPECTED FOR MUCH OF TODAY AS A COLD FRONT
SLOWLY APPROACHES FROM THE WEST.
AN AREA OF MAINLY LIGHT SHOWERS OVER CENTRAL GA CONTINUES TO SLOWLY
MOVE TOWARDS THE CSRA. AS A COLD FRONT NEAR THE TN VALLEY SLOWLY
MOVES EASTWARD...MOISTURE WILL INCREASE ACROSS THE AREA EARLY THIS
MORNING. LATEST RADAR TRENDS THE SHOWERS WILL MOVE INTO THE CSRA
EARLY THIS MORNING AND THEN INTO THE MIDLANDS BY AROUND 12Z-13Z.
WILL ADD MENTION OF -SHRA AT AGS AND DNL...AND VCSH AT THE OTHER TAF
SITES. THE POTENTIAL FOR CONVECTION WILL INCREASE DURING THE DAY.
THUNDER WILL BE POSSIBLE DURING THE AFTERNOON. WILL USE VCTS FOR ALL
TAF STIES DURING THE AFTERNOON AND INTO THE EVENING HOURS. WINDS
WILL BE SOUTHERLY AT AROUND 5 TO 10 KNOTS EARLY THIS MORNING AND
WILL INCREASE LATER THIS MORNING TO AROUND 12 KNOTS WITH GUSTS UP TO
20 KNOTS. WIND SPEEDS WILL DIMINISH SOMEWHAT BY THIS EVENING.
.EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN SHOWERS AND
THUNDERSTORMS THROUGH THURSDAY NIGHT AS THE FRONTAL SYSTEM SLOWLY
CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
608 AM EDT WED APR 30 2014
.SYNOPSIS...
THE THREAT OF STORMY WEATHER WILL CONTINUE INTO TONIGHT. A SLOW
MOVING FRONTAL SYSTEM WILL CROSS THE AREA TONIGHT THEN STALL NEAR
THE COAST FOR THURSDAY. COOL AND DRY HIGH PRESSURE WILL BUILD
ACROSS THE REGION FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN UPPER RIDGE WAS OFF THE EAST COAST WITH A DEEP/LARGE CYCLONE
OVER SOUTHERN MN. THIS PATTERN WILL FINALLY SHIFT BY THURSDAY AS
THE UPPER RIDGE OFF THE COAST MOVES FARTHER OUT TO SEA ALLOWING
THE UPPER LOW TO LIFT NORTHEAST INTO THE GREAT LAKES REGION.
THE SURFACE COLD FRONT EXTENDING FROM CENTRAL KENTUCKY TO THE
LOUISIANA COAST WILL SLOWLY MOVE EAST REACHING THE UPSTATE EARLY
THIS EVENING. OUR AREA WILL REMAIN IN THE WARM SECTOR AHEAD OF THE
FRONT TODAY. PWAT IS FORECAST TO INCREASE TO JUST OVER 1.80
INCHES WITH MODERATE TO STRONG INSTABILITY AS WELL AS STRONG
MOISTURE TRANSPORT AND DIVERGENCE ALOFT. STRONG SHEAR IS FORECAST
WITH H8 WINDS 35 TO 45 KNOTS. SPC STILL HAS THE AREA IN A SLIGHT
RISK FOR SEVERE WEATHER.
CONVECTION WAS INCREASING ACROSS THE MIDLANDS AND CSRA EARLY THIS
MORNING. THE SPC WRF AND HRRR MODELS INDICATE THE BEST CHANCE FOR
CONVECTION THROUGH MIDDAY WITH THE PRECIP SHIFTING CLOSER TO THE
COAST THIS AFTERNOON. CONVECTION ALONG THE GULF COAST COULD ACT TO
DECREASE CONVECTION ACROSS THE MIDLANDS AND CSRA. SO HAVE
INCREASED POPS FOR THE MORNING. POPS IN THE 60 TO 80 PERCENT RANGE
TODAY. HIGH CHANCE POPS LOOK REASONABLE TONIGHT...GIVEN THE
FRONTAL PASSAGE.
LEANED TOWARD THE WARMER GUIDANCE FOR MAX TEMPS TODAY SINCE
TEMPERATURES WILL START THE DAY IN THE UPPER 60S TO LOWER 70S.
WENT WITH CONSENSUS FOR MILD TEMPERATURES IN THE UPPER 50S WEST TO
MID 60S EAST TONIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
THE FRONTAL BOUNDARY WILL REACH THE COAST THURSDAY MORNING THEN
STALL. ALL MODELS SHOW DEEP MOISTURE SHIFT EAST OF THE FORECAST
AREA EARLY THURSDAY. A STABLE AIR MASS AND COLD AIR ADVECTION WILL
OVERSPREAD THE AREA FROM THE WEST...DIMINISHING THE CHANCE FOR
SHOWERS THURSDAY. KEPT A CHANCE FOR SHOWERS FRIDAY ACROSS MAINLY
THE EASTERN PORTION OF THE CWA AS MOISTURE SURGES NORTHWARD ALONG
THE STALLED FRONT. COOLER TEMPERATURES ARE EXPECTED WITH HIGHS IN
THE 75 TO 80 DEGREE RANGE THURSDAY THEN IN THE LOWER 70S FRIDAY.
OVERNIGHT LOWS SHOULD BE IN THE 50S THURSDAY NIGHTS...UPPER 40S TO
LOWER 50S FRIDAY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE GFS AND ECMWF INDICATE A DRY PATTERN FOR THE WEEKEND THROUGH
EARLY NEXT WEEK. SURFACE RIDGING JUST TO THE SOUTH WILL DOMINATE
WITH THE UPPER PATTERN DE-AMPLIFYING. TEMPERATURES THROUGH THE
MEDIUM RANGE PERIOD WILL BEGIN BELOW NORMAL SATURDAY...BEFORE
GRADUALLY WARMING TO ABOVE NORMAL FOR THE BEGINNING OF NEXT WEEK.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
VFR WITH PERIODS OF MVFR EXPECTED FOR MUCH OF TODAY AS A COLD FRONT
SLOWLY APPROACHES FROM THE WEST.
AN AREA OF MAINLY LIGHT SHOWERS OVER CENTRAL GA CONTINUES TO SLOWLY
MOVE TOWARDS THE CSRA. AS A COLD FRONT NEAR THE TN VALLEY SLOWLY
MOVES EASTWARD...MOISTURE WILL INCREASE ACROSS THE AREA EARLY THIS
MORNING. LATEST RADAR TRENDS THE SHOWERS WILL MOVE INTO THE CSRA
EARLY THIS MORNING AND THEN INTO THE MIDLANDS BY AROUND 12Z-13Z.
WILL ADD MENTION OF -SHRA AT AGS AND DNL...AND VCSH AT THE OTHER TAF
SITES. THE POTENTIAL FOR CONVECTION WILL INCREASE DURING THE DAY.
THUNDER WILL BE POSSIBLE DURING THE AFTERNOON. WILL USE VCTS FOR ALL
TAF STIES DURING THE AFTERNOON AND INTO THE EVENING HOURS. WINDS
WILL BE SOUTHERLY AT AROUND 5 TO 10 KNOTS EARLY THIS MORNING AND
WILL INCREASE LATER THIS MORNING TO AROUND 12 KNOTS WITH GUSTS UP TO
20 KNOTS. WIND SPEEDS WILL DIMINISH SOMEWHAT BY THIS EVENING.
.EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN SHOWERS AND
THUNDERSTORMS THROUGH THURSDAY NIGHT AS THE FRONTAL SYSTEM SLOWLY
CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1030 AM EDT WED APR 30 2014
.SYNOPSIS...
A STRONG AND SLOW MOVING LOW PRESSURE SYSTEM OVER THE CENTRAL
PORTION OF THE U.S. WILL BRING UNSETTLED WEATHER TO CENTRAL NC
THROUGH EARLY THURSDAY. A COLD FRONT WILL MOVE SLOWLY EASTWARD
THROUGH THE REGION THURSDAY THROUGH THURSDAY NIGHT. DRIER WEATHER IS
EXPECTED HEADING INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...
THE WEDGE/WARM FRONT CONTINUES TO PUSH NORTHWEST AND IS JUST EAST
IF THE TRIAD...PUTTING NEARLY ALL OF CENTRAL NC IN THE WARM SECTOR
CHARACTERIZED BY LOWER 70 DEWPOINTS. REGIONALLY...THERE IS
WIDESPREAD CLOUD COVER FROM CONVECTION ALONG THE GULF COAST...BUT
SPC MESOANALYSIS SHOWS DESTABILIZATION ALREADY UNDERWAY IN THE WARM
SECTOR...AIDED BY RELATIVELY STEEP MID LEVEL LAPSE RATES BETWEEN
850MB AND 500MB PER THE KGSO 12Z RAOB. LATEST RAP SOUNDINGS SHOW
1000-2000 J/KG MLCAPE IN THE WARM SECTOR BY EARLY AFTERNOON. BULK
SHEAR CONTINUES TO BE STRONG WITH A CORRIDOR OF 45-50KT OVER THE
WESTERN HALF OF THE STATE. LOW-LEVEL HODOGRAPHS REMAIN CYCLONICALLY
CURVED WITH SOUTHEASTERLY SURFACE WINDS AND A 40KT 850MB FLOW OVER
THE CAROLINAS. OUTSIDE OF THE RETREATING WEDGE FRONT...TRIGGERS FOR
CONVECTION ARE A LITTLE MORE NEBULOUS...BUT CONVECTION IS ALREADY
ONGOING OVER CENTRAL SC...WITH A REMNANT MCV OVER THE SAVANNAH RIVER
BASIN. RAP VORT FORECASTS BRING THIS MCV OVER THE SANDHILLS IN THE
17-19Z TIME FRAME. THIS MAY THE MOST OBVIOUS FEATURE UPSTREAM TO
KEY ON...THOUGH CONVECTION SHOULD CONTINUE TO DEVELOP ALONG
DIFFERENTIAL HEATING AND OUTFLOW BOUNDARIES. ALL OF THESE
INGREDIENTS WILL SUPPORT SEVERE STORMS WITH THE POTENTIAL FOR LARGE
HAIL...DAMAGING WINDS AND ISOLATED TORNADOES.
GIVEN THAT THE TRIAD IS CLOSE TO BEING SCOURED OUT FO THE STABLE
AIRMASS...WILL FORECAST HIGHS IN THE 75-83 RANGE.
WHILE RAINFALL HAS BEEN A LITTLE LACK LUSTER OVER THE PIEDMONT...
STORM MOTION TODAY SHOULD STILL SUPPORT TRAINING OF CELLS....AND
AREAS ALONG THE I-95 CORRIDOR WERE MORE THAN PRIMED WITH LAST
EVENINGS RAINFALL. THUS...THE FLASH FLOOD WATCH WILL CONTINUE TODAY.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 330AM WEDNESDAY...
THURSDAY...THREAT FOR SCATTERED SHOWERS AND A FEW T-STORMS WILL
REMAIN BASICALLY EAST OF HIGHWAY 1 THROUGH MID DAY....AND EAST OF I-
95 THROUGH LATE AFTERNOON AS MID LEVEL TROUGH CROSSES THE REGION.
WIND PROFILES AND AVAILABLE INSTABILITY SUGGEST THAT STORMS SHOULD
REMAIN BELOW SEVERE CRITERIA. SLIGHTLY COOLER TEMPS THU WITH MAX
TEMPS RANGING BETWEEN THE MID 70S NE TO AROUND 80 SE.
A MORE STABLE...DRIER...COOLER AIR MASS WILL SETTLE OVER THE
FORECAST AREA THURSDAY NIGHT INTO FRIDAY. A WEAK UPPER DISTURBANCE
PASSING OVERHEAD FRIDAY AFTERNOON MAY TRIGGER AN ISOLATED SHOWER OR
TWO OVER OUR SE COUNTIES...IF ENOUGH MOISTURE IS AVAILABLE. MAX
TEMPS FRIDAY NEAR 70-LOWER 70S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 325 PM TUESDAY...
MAY STILL SEE SOME LINGERING CLOUDS IN THE COASTAL PLAIN SAT MORNING
AS THE MID LEVEL TROUGH AXIS FINALLY SHIFTS TO OUR EAST... BUT
OTHERWISE EXPECT A DRY AND SEASONABLE AIR MASS TO START THE WEEKEND.
A WEST-EAST ORIENTED BACKDOOR FRONT TO OUR NORTH WILL INCH SOUTHWARD
TOWARD THE NRN NC BORDER SUNDAY... AS A STRONG MID LEVEL SHORTWAVE
TROUGH TRAVERSES THE NORTHEAST STATES... BUT THE FRONT SHOULD HOLD
TO OUR NORTH THROUGH SUNDAY WITH SOMEWHAT MILDER AIR SPREADING INTO
NC FROM THE WEST. THE AFOREMENTIONED SHORTWAVE TROUGH IS LIKELY TO
DEEPEN AS A CLOSED VORTEX OVER THE NEW ENGLAND COAST SUN NIGHT THEN
WOBBLE VERY SLOWLY EASTWARD THROUGH TUE... AND THIS WILL ALLOW THE
SURFACE FRONTAL ZONE TO STRENGTHEN AND BECOME NEARLY STATIONARY FROM
THE OH VALLEY ACROSS NE NC.... KEEPING US ON THE WARM SIDE OF THE
BOUNDARY THROUGH EARLY NEXT WEEK. IN THIS SORT OF A NORTHWEST FLOW
PATTERN THERE IS THE POTENTIAL FOR UPSTREAM CONVECTION OVER THE OH
VALLEY TO TRACK SOUTHEASTWARD ACROSS NC... AND FOR NOW WILL LEAVE IN
A SLIGHT CHANCE OF SHOWERS AND STORMS FOR MON/TUE. TEMPS CLOSE TO
SEASONAL NORMALS (WHICH IS LOW-MID 50S FOR LOWS AND MID-UPPER 70S
FOR HIGHS). -GIH
&&
.AVIATION /12Z WEDNESDAY THROUGH MONDAY/...
AS OF 750 AM WEDNESDAY...
LIFR CEILINGS WILL LINGER THROUGH 12-14Z IN THE TRIAD AS THE
RESIDUAL WEDGE AIRMASS GRADUALLY ERODES. THE WARM FRONT WILL LIFT
NORTH OF THE TRIAD IN THE MID MORNING...WITH WINDS VEERING TO
SOUTHERLY AND INCREASING TO 12-15KT WITH GUSTS TO 25KT.
WINDS WILL BE BREEZY OUT OF THE SOUTH...WITH 15 KNOTS GUSTING TO 25
KNOTS OVER THE AREA AFTER 15Z. CEILINGS WILL BE MAINLY MVFR AND
VISIBILITIES VFR OUTSIDE OF CONVECTION THROUGH AROUND 04Z...WITH
CEILINGS LOWERING TO IFR TONIGHT AS THE AIRMASS COOLS AND WINDS
SUBSIDE A BIT. THIS MAKES THE FORECAST DETAIL AND TIMING QUITE
PROBLEMATIC AS A DEEP PLUME OF MOISTURE OFF THE GULF WILL MAINTAIN
HIGH CHANCES OF CONVECTION ACROSS THE ENTIRE AREA TODAY...WITH THE
HIGHEST CHANCE OF STRONGER THUNDERSTORM ACTIVITY IN THE AFTERNOON
INTO EVENING...16Z-02Z WHEN INSTABILITY WILL PEAK DIURNALLY.
IN THE LONGER RANGE...THE SURFACE FRONT WILL BE SLOWLY EDGING
EAST...WITH LINGERING MVR CONDITIONS AND SHOWERS GRADUALLY IMPROVING
TO VFR IN THE WEST BY MID DAY THURSDAY. STRONGER CONVECTION WITH
THUNDER WILL LINGER IN THE EAST THROUGH AROUND SUNSET
THURSDAY...WITH IMPROVING CONDITIONS AROUND 00Z. A STRONGER COLD
FRONT WILL BE MOVING ACROSS THE AREA FRIDAY NIGHT/SATURDAY WITH VFR
CONDITIONS EXPECTED THURSDAY NIGHT THROUGH MONDAY
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR NCZ007>011-021>028-
038>043-073>078-083>086-088-089.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...WSS/SMITH
SHORT TERM...WSS
LONG TERM...HARTFIELD
AVIATION...MLM
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1024 AM EDT WED APR 30 2014
.SYNOPSIS...
A COLD FRONT TO THE WEST WILL MOVE THROUGH THURSDAY NIGHT. WEAK
HIGH PRESSURE CENTERED TO THE SOUTHWEST WILL EXTEND INTO THE
CAROLINAS FRIDAY THROUGH SUNDAY. A COLD FRONT WILL DROP SOUTH
THROUGH THE AREA SUNDAY. IT WILL BECOME STATIONARY TO THE
SOUTHWEST MONDAY AND TUESDAY.
&&
.NEAR TERM /TODAY/...
AS OF 1015 AM WED...LATEST SFC ANALYSIS SHOWS FRONTAL BOUNDARY NOW
NORTH OF THE AREA. MAIN SFC LOW CURRENTLY NEAR THE GREAT LAKES AND
ATTENDANT COLD FRONT MOVING THROUGH THE OH/TN VALLEY REGION...WITH
ENC REMAINING IN THE WARM SECTOR. MADE MINOR TWEAKS TO FORECAST
BASED ON LATEST TRENDS.
EASTERN NC REMAINS IN SLIGHT RISK OF SEVERE WX TODAY. SLIGHTLY BETTER
FORCING AND SHEAR AS UPPER TROUGH AND COLD FRONT APPROACH FROM
THE WEST. ONLY LIMITING FACTOR COULD BE CLOUD COVER THIS MORNING
AND LACK OF INSOLATION. SCT ACTIVITY ALREADY STARTING TO DEVELOP
THIS MORNING IN SE NC. FORECAST SOUNDINGS AND SPC MESOANALYSIS
SHOW CAPES 1500-2500J/KG...LI VALUES -4 TO -6C...AND 0-6KM SHEAR
AROUND 30KT. MAIN THREATS STILL LOOK LIKE POTENTIAL FOR DAMAGING
WIND GUSTS...HAIL...ISOLATED TORNADOES AND HEAVY RAIN. HIGH RES
MODELS NSSL WRF AND NMM HAVE CONVECTION LATE THIS MORNING AND
EARLY AFTERNOON BECOMING MORE ORGANIZED THIS AFTERNOON MOVING INTO
THE COASTAL PLAIN...WITH NMM AND HRRR SHOWING THE LINE WEAKENING
BUT HOLDING TOGETHER MOVING EASTWARD TOWARD THE COAST THIS
EVENING. AT THIS TIME THE BEST CHANCES FOR SVR WX LOOK TO BE AREAS
ALONG AND WEST OF HIGHWAY 17...MAINLY BTWN 2-10PM. WITH THE
POTENTIAL FOR ADDITIONAL HEAVY RAINFALL...THE ALREADY SATURATED
GROUND IN THE COASTAL PLAIN COULD SEE MORE SIGNIFICANT FLOODING
PROBLEMS...MAINLY MARTIN/PITT/GREENE AND LENOIR COUNTIES WHICH SAW
SEVERAL INCHES OF RAIN YESTERDAY.
HIGHS TODAY IN THE MID 70S TO MID 80S WITH DEWPOINTS IN THE 60S.
&&
.SHORT TERM /TONIGHT/...
AS OF 345 AM WED...THE COLD FRONT WILL BE MOVING THROUGH THE MID-
STATE AREA TONIGHT. MODELS SHOW AXIS OF INSTABILITY SHIFTING EAST
INTO EASTERN NORTH CAROLINA. MAINTAINED LIKELY WEST TO CHANCE EAST
THIS EVENING...BECOMING LIKELY ALL AREAS AFTER MIDNIGHT. WARM AND
MUGGY CONDITIONS FORECAST WITH LOWS THROUGHOUT IN THE UPPER 60S.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 345 AM WED...A SWATH OF DEEP MOISTURE ACCOMPANYING A SLOW
MOVING MID LEVEL TROF WILL OVERSPREAD THE REGION DURING THE DAY
THURSDAY THEN MOVE THRU THE FORECAST AREA THURSDAY NIGHT. STILL
SOME MODEL TIMING DIFFERENCES ON THE BEST COVERAGE OF PRECIP WILL
OCCUR SO WILL CONTINUE TO HOLD POPS MAINLY IN THE LIKELY RANGE FOR
NOW THRU AROUND MIDNIGHT THURSDAY. THE BEST CHANCES FOR SEVERE
STORMS/POSSIBLE TORNADOES WILL BE DURING PEAK DIURNAL HEATING
DURING THE AFTERNOON AND LINGERING INTO THE EARLY EVENING HOURS.
CLOUD COVER MAY LIMIT POTENTIAL INSTABILITY BUT VEERING VERTICAL
WIND PROFILES AS A 50 KT LLJ CROSSES THE AREA WILL SUSTAIN
UPDRAFTS/ROTATING THUNDERSTORMS INTO THE EVENING HOURS. WITH MID-
UPPER 60S DEW POINTS AND PRECIP WATER CONTINUING +2SD ABV NORMAL,
HEAVY DOWNPOURS WILL ACCOMPANY STRONG CONVECTION WITH 1-2 INCHES
OF RAIN LIKELY WITH LOCALLY HIGHER AMOUNTS POSSIBLE.
MID LEVEL DRY SLOT AND SFC FRONTAL PASSAGE SIGNALS AN END TO THE
STEADIER PRECIP FOR MOST AREAS LATE THU EVENING BUT A BIT OF
LINGERING LIGHT RAIN THRU EARLY FRIDAY MORNING ALONG THE COAST.
THE FRONT STALLS OUT UNDER PARALLELING WSW STEERING FLOW OFF THE
COAST FRIDAY. MODELS HAVE BEEN CONSISTENT IN SHOWING A WEAK WAVE OF
LOW PRESSURE DEVELOPING ON THE FRONT AND TEMPORARILY PUSH AN AREA OF
DEEPER MOISTURE AND WEAK FORCING ONTO THE SE NC COAST LATE FRIDAY
AND FRIDAY NIGHT. WILL CONTINUE WITH SLIGHT CHANCES FOR RAIN
CONFINED TO SE AREAS ONLY THRU FRIDAY NIGHT. GOOD MODEL CONSENSUS IS
DEVELOPING TO PUSH THE STALLED BNDRY OUT TO SEA EARLY SATURDAY
LEADING TO A DRY AND PLEASANT WEEKEND. TEMPS WILL BE A BIT BLO
NORMAL FOR SATURDAY AND SATURDAY NIGHT THEN NEAR SEASONAL AVERAGES
ON SUNDAY WITH HIGHS NEARING 80F INLAND.
A NORTHERN STREAM SHORT WAVE WILL DRIVE A WEAK BACKDOOR COLD FRONT
THRU THE AREA LATE SUNDAY NIGHT OR EARLY MONDAY. LITTLE AVAILABLE
MOISTURE TO PRODUCE WIDESPREAD PRECIP SO WILL KEEP FORECAST DRY FOR
NOW. THIS FRONT EVENTUALLY STALLS SW OF THE AREA ON TUESDAY WITH
HIGH PRESSURE BUILDING IN FROM THE NORTH.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 7 AM WED...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
FORECAST AT ALL 4 AREA TERMINALS ESPECIALLY THIS AFTERNOON INTO
THE OVERNIGHT. ANY STORM HAS THE POTENTIAL TO PRODUCE DAMAGING
DOWNBURST WINDS...HAIL AND POSSIBLY A TORNADO. SURFACE WINDS WILL
BE FROM THE SOUTH AT 15-20 KNOTS TODAY INTO TONIGHT. CONDITIONS
GENERALLY VFR OUTSIDE OF CONVECTION.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 345 AM WED...UNSETTLED CONDITIONS CONTINUE INTO THURSDAY
EVENING WITH SCT TO NUMEROUS SHOWERS/STORMS AND SUB VFR
CONDITIONS. DRIER AIR IS FINALLY EXPECTED TO FILTER INTO THE AREA
THURSDAY NIGHT AND FRIDAY AND ESPECIALLY SATURDAY AND SUNDAY AS
HIGH PRESSURE BUILDS INTO EASTERN NC. OTHER THAN EARLY MORNING FOG
PATCHES VFR CONDITIONS ARE EXPECTED TO PREVAIL LATE IN THE WEEK
AND FOR MUCH OF THE UPCOMING WEEKEND.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 10 AM WED...NO SIG CHANGES NEEDED TO ONGOING FORECAST THIS
MORNING. LATEST OBS SHOW SE/S WINDS 10-20KT WITH SEAS
4-8FT...HIGHEST NORTH OF OCRACOKE. SMALL CRAFT ADVISORIES CONTINUE
FOR ALL COASTAL WATERS AND THE PAMLICO SOUND...WITH THE ALBEMARLE
SOUND AND RIVERS CAPPED AT 15-20 KNOTS.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 345 AM WED...SW WINDS 15 TO 25 KT WILL OCCUR AHEAD OF THE
FRONT INTO THURSDAY EVENING. THE FRONT WILL SLOWLY PUSH OFFSHORE
BY EARLY FRI WITH WINDS DIMINISHING AND BECOMING W TO NW 10 TO 15
KTS. SEAS SHLD SUBSIDE WITH SCA ENDING ALL WTRS BY FRI MORNING.
THE FRONT STALLS OFF THE COAST FRI INTO SAT THEN EDGES EAST SUNDAY
AS HIGH PRESSURE BUILDS OVER THE WATERS. EXPECT SUB ADVISORY
CONDITIONS FRIDAY AFTERNOON INTO SUNDAY WITH WESTERLY WINDS 15 KT
OR LESS AND SEAS 2-4 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 PM EDT
THURSDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT FRIDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR AMZ150-156-158.
&&
$$
SYNOPSIS...HSA
NEAR TERM...HSA/CQD
SHORT TERM...HSA
LONG TERM...BTC
AVIATION...BTC/HSA
MARINE...BTC/HSA/CQD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
708 AM EDT WED APR 30 2014
.SYNOPSIS...
A COLD FRONT ACROSS WESTERN TENNESSEE AND MISSISSIPPI WILL MOVE
ACROSS THE EASTERN CAROLINAS THURSDAY NIGHT. WAVES OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED...WITH A GROWING RISK OF SEVERE WEATHER
WEDNESDAY. HIGH PRESSURE WILL BRING DRY WEATHER FOR THE WEEKEND...
ALTHOUGH A FRONT MAY APPROACH THE AREA FROM THE NORTH EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 7 AM WEDNESDAY...A LULL IN THE ACTION CONTINUES THIS MORNING
ALTHOUGH A FEW LIGHT SHOWERS ARE BREAKING OUT HERE AND THERE. NO
CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS
DISCUSSION FOLLOWS:
LOOKS LIKE THE PERSISTENT WARM FRONT DRAPED ACROSS OUR NORTHERN
FRINGES HAS FINALLY BEGUN LIFTING NORTH...MOVING US MORE FIRMLY IN
THE WARM SECTOR OF THE APPROACHING FRONTAL SYSTEM.
MEANWHILE...ISOLATED WEAK CONVECTION HAS BEEN BREAKING OUT ACROSS
OUR INLAND COUNTIES. A MUCH MORE EXTENSIVE AREA OF CONVECTION OVER
GEORGIA BEING SUSTAINED BY AN UPPER DISTURBANCE IS GRADUALLY
MOVING IN THIS DIRECTION...AND THIS MCS WILL LIKELY AFFECT OUR
SOUTHWESTERN COUNTIES LATE THIS MORNING BEFORE FURTHER SPREADING
NORTHEAST...AFFECTING THE REMAINDER OF THE AREA.
THE AIRMASS TODAY AND TONIGHT WILL REMAIN WARM AND MOIST...WITH
DEWPOINTS IN THE UPPER 60S TO EVEN LOWER 70S IN PLACES. ALTHOUGH
CONVECTIVE INDICES ARE GENERALLY FAVORABLE FOR SCATTERED TO
WIDESPREAD CONVECTION...CAPE WILL BE ON THE MODEST SIDE. PLUS...THE
MID LEVELS...AT LEAST THE DAYTIME HOURS...WILL NOT BE AS SATURATED
AS I WOULD LIKE TO SEE FOR CATEGORICAL POPS. THUS WILL LIMIT DAYTIME
POPS TO LIKELY...EXCEPT FOR A STRIP OF CATEGORICAL ACROSS OUR FAR
NORTHWESTERN COUNTIES THIS AFTERNOON AND EVENING. THE BIG DEAL
THOUGH IS THAT SHEAR PROFILES DO LOOK FAVORABLE FOR ORGANIZED STORM
FORMATION...WITH THE POTENTIAL FOR TORNADOES AND LINES OF SEVERE
CONVECTION. BEST POTENTIAL WILL BE AWAY FROM THE COAST...AWAY FROM
THE INFLUENCE OF THE MARINE LAYER...LATE THIS AFTERNOON AND EVENING.
DEEP UPPER LONGWAVE TROUGH OVER CENTRAL CONUS WILL SWING SLOWLY
EASTWARDS...DRIVING A COLD FRONT ACROSS THE FORECAST AREA OVERNIGHT.
LOW LEVEL CONVERGENCE IN ADVANCE OF FRONT WILL CONTINUE THE
POTENTIAL FOR STRONG TO SEVERE CONVECTION INTO AT LEAST THE EVENING
HOURS. FRONT WILL BE POISED TO MOVE OFFSHORE BY AROUND DAYBREAK.
TEMPERATURES WILL REMAIN ABOVE AVERAGE THROUGH THE PERIOD...WITH
HIGHS IN THE LOWER 80S...AND LOWS IN THE MID TO UPPER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...COLD FRONT ASSOCIATED WITH STACKED LOW MOVING
INTO THE GREAT LAKES WILL BE WEST OF THE AREA AS THE PERIOD BEGINS.
ALTHOUGH THE FRONT WILL NOT BE FAR FROM THE AREA IT WILL TAKE A LONG
TIME TO PUSH OFFSHORE...NOT DOING SO UNTIL THU NIGHT AT WHICH POINT
IT ENDS UP STALLING ALONG OR JUST OFF THE COAST. THE ALMOST CUTOFF
NATURE OF THE 5H LOW OVER THE UPPER MID-WEST AND OCCLUDED NATURE OF
THE PARENT LOW TRANSLATE TO SLOW SURFACE FEATURE MOVEMENT. IT ALSO
MEANS THE COLD PUSH BEHIND THE FRONT WILL BE OF LIMITED STRENGTH AND
DURATION. TEMPS ABOVE CLIMO THU/THU NIGHT WILL BE KNOCKED BELOW
CLIMO FOR FRI/FRI NIGHT BUT ONLY BY A FEW DEGREES.
CONVERGENCE ALONG THE FRONT WILL BE WEAK AND ONCE THE NOCTURNAL JET
MIXES OUT THERE WILL BE NO LOW LEVEL JETTING THU AND FLOW WILL BE
UNIDIRECTIONAL. AIRMASS WILL STILL BE UNSTABLE...ESPECIALLY ONCE
TEMPS WARM UP A BIT. HOWEVER DIURNAL HEATING WILL BE TEMPERED BY
CLOUD COVER SO INSTABILITY WILL BE SOMEWHAT LIMITED. THE RESULT
SHOULD BE A DAY WITH WIDESPREAD SHOWERS AND THUNDERSTORMS...BUT WITH
INTENSITY LIKELY TO FALL SHORT OF SEVERE CRITERIA. CAN SEE NO REASON
TO ARGUE WITH INHERITED LIKELY POP THU INTO THU NIGHT.
FRONT WILL REMAIN STALLED OFF THE COAST FRI AND FRI NIGHT WITH DEEP
SOUTHWEST FLOW KEEPING MID LEVELS MOIST. WESTERLY LOW LEVEL FLOW
WILL WORK TO DRY THE LOW LEVEL OUT...SOMETHING READILY APPARENT IN
FORECAST SOUNDINGS. ALTHOUGH THE LOW LEVEL DRY AIR WILL BE
SIGNIFICANT CANNOT RULE OUT ISOLATED SHOWERS. COMBINATION OF DEEP
MID LEVEL MOISTURE AND PVA SPREADING OVER THE AREA DURING THE
AFTERNOON COULD GENERATE SOME WEAK ACTIVITY. BEST PRECIP CHANCES
WILL BE ALONG THE COAST AND HAVE LOW CHC POP AT THE COAST DECREASING
TO SLIGHT CHC POP FARTHER INLAND. ISOLATED SHOWERS MAY LINGER INTO
THE OVERNIGHT...ESPECIALLY ALONG THE COAST WHERE ACTIVITY OVER THE
WATERS COULD BRUSH THE COAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...PERIOD WILL BEGIN WITH MID LEVEL TROUGHING IN
PLACE BUT A TRANSITION TO MID LEVEL RIDGING FOR EARLY NEXT WEEK IS
EXPECTED. MID LEVEL TROUGH AXIS REMAINS WEST OF THE AREA SAT WITH
STALLED FRONT LINGERING JUST OFF THE SOUTHEAST COAST. DEEPEST
MOISTURE WILL REMAIN OFFSHORE INTO SUN BUT WEAKLY DIVERGENT FLOW
ALOFT AND PRESENCE OF A SHORTWAVE OR TWO COULD GENERATE SOME LIGHT
PRECIP ALONG THE IMMEDIATE COAST AND OVER THE WATERS.
SOUTHERN STREAM SHORTWAVE MOVES ACROSS THE SOUTHEAST LATE
SAT...MOVING OFF THE GA/SC COAST SAT NIGHT. THIS FEATURE WILL HELP
PUSH THE STALLED FRONT OUT TO SEA EARLY NEXT WEEK AND BRING AN
EXTENDED PERIOD OF DRY WEATHER. THERE WILL BE A WEAK BACKDOOR COLD
FRONT THAT DROPS SOUTH AND STALLS IN THE AREA MON INTO TUE. FRONT
WILL PASS DRY AS IT LACKS DEEP MOISTURE AND LOW LEVEL CONVERGENCE IS
QUITE WEAK. BUILDING MID LEVEL RIDGE AND SURFACE HIGH EXPANDING
NORTH WILL PUSH THE FRONT BACK NORTH TUE NIGHT.
WEAK COLD ADVECTION AND LINGERING CLOUD COVER WILL KEEP HIGHS A
LITTLE BELOW CLIMO SAT...ESPECIALLY ALONG THE COAST. SUNSHINE ON SUN
WILL PUSH TEMPS NEAR TO SLIGHTLY ABOVE CLIMO. SIMILAR TEMPERATES
ARE EXPECTED MON/TUE DESPITE PRESENCE OF WEAK FRONT.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...CONVECTION HAS ALL BUT ENDED. THE HRRR MODEL DOES SHOW
ISOLATED SHOWERS OVERNIGHT BUT THAT`S ABOUT IT. MOIST SOUTH
SOUTHWEST FLOW OVERNIGHT IS EXPECTED TO BRING IN IFR STRATUS AT ALL
SITES...BEGINNING WITH THE MYRTLES.
WEDNESDAY...IFR WILL LIFT TO MVFR WITH CONVECTION INCREASING
THROUGHOUT THE DAY. EVEN WITH THE CLOUD COVER...SHOULD SEE CAPES
AROUND 1000 J/KG WITH PRECIPITABLE WATER APPROACHING TWO INCHES. SHOWERS
WILL BE FAIRLY WIDESPREAD BY MIDDAY INLAND...SPREADING TO THE COAST
BY 18Z OR SO. THE GFS SEEMS TO BE WETTER AND FASTER THAN THE NAM.
THE MARINE LAYER MAY BE A DETERRENT FOR CONVECTION AT THE
COAST...HOWEVER THE SOUTHWEST FLOW MAY BE STRONG ENOUGH TO PIN THE
RESULTANT.
EXTENDED OUTLOOK...SCATTERED AFTERNOON/EVENING SHOWERS AND
THUNDERSTORMS POSSIBLE THROUGH THURSDAY. CHANCE FOR SHOWERS FRIDAY
NIGHT INTO SATURDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 7 AM WEDNESDAY...SMALL CRAFT ADVISORY REMAINS IN PLACE WITH
NO CHANGES. PREVIOUS DISCUSSION FOLLOWS:
GRADUALLY INCREASING SOUTHERLY FLOW IN ADVANCE OF A COLD FRONT
WILL BUILD SEAS INTO THE 4 TO 6 FT RANGE BY THIS AFTERNOON. WINDS
WILL INCREASE FROM PRESENT 10 TO 15 KTS TO 15 TO 20 KTS LATER THIS
MORNING. SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT THROUGH THE
NEAR TERM.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...STRONG SOUTHWEST FLOW WILL CONTINUE THU AHEAD
OF A SLOW MOVING COLD FRONT. SCA HEADLINES WILL LIKELY NEED TO BE
CARRIED INTO THU AFTERNOON AND POSSIBLY EARLY EVENING FOR SOME
ZONES. ALTHOUGH HIGHEST SPEEDS ARE LIKELY TO BE AROUND 20 KT
PROLONGED PERIOD OF ENHANCED SOUTHWEST FLOW WILL BUILD SEAS OVER 6
FT. FRONT MOVES OFFSHORE THU NIGHT WITH WINDS SHIFTING TO NORTHWEST
AND SPEEDS DROPPING TO 10 TO 15 KT BY FRI MORNING. GRADIENT REMAINS
SOMEWHAT PINCHED AND WEST TO SOUTHWEST FLOW WILL STAY IN THE 10 TO
15 KT RANGE THROUGH THE END OF THE PERIOD. SEAS 4 TO 7 FT THU WILL
DROP TO 3 TO 5 FT THU NIGHT WITH THE PASSAGE OF THE COLD FRONT. SEAS
CONTINUE TO SUBSIDE FRI DROPPING FROM 2 TO 4 FT AT THE START OF THE
PERIOD 2 TO 3 FT BY SAT MORNING.
.LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...FRONT STALLED EAST OF THE WATERS SAT WILL
MOVE FARTHER OFFSHORE SUN. WEAK GRADIENT WILL BE IN PLACE DURING THE
PERIOD KEEPING WEST TO SOUTHWEST FLOW AROUND 10 KT FOR MUCH OF THE
PERIOD. SEAS WILL BE AROUND 2 FT THROUGH THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR AMZ250-252-
254-256.
&&
$$
SYNOPSIS...III
NEAR TERM...REK
SHORT TERM...III
LONG TERM...III
AVIATION...DL
MARINE...REK/III
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
935 AM CDT WED APR 30 2014
.UPDATE...
ISSUED AT 935 AM CDT WED APR 30 2014
NO SIGNIFICANT CHANGES TO THE PACKAGE ARE PLANNED FOR THIS
MORNING...JUST A FEW SUBTLE POP TWEEKS. IR SATELLITE IMAGERY SHOWS
THAT COOLEST CLOUD TOPS HAVE NOW ROTATED WEST OF AN HCO-GFK- OAKES
LINE...WITH VERY LIGHT RAIN OR MIST LINGERING BEHIND. ADDITIONAL
BANDED PRECIP IS SHOWING ON RADAR FM FSE INTO BJI AND GPZ...MOVING
WESTWARD...WITH HRRR SHOWING OVERALL REGEN OF PRECIP ACROSS
NORTHWESTERN MN BY MIDDAY.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 400 AM CDT WED APR 30 2014
THE MAIN CHALLENGE WILL BE PRECIP OVER THE NEXT SEVERAL DAYS AND
TEMPS. MODELS CONTINUE IN VERY GOOD OVERALL AGREEMENT...WITH NO
PREFERENCE THIS MORNING.
FOR TODAY...IT WILL BE A VERY COLD AND RAINY DAY FOR THE REGION.
THERE COULD BE SOME SNOW FLAKES MIXING IN AT TIMES BEFORE
18Z...NEAR ANY HEAVIER PRECIP BANDS. NOT EXPECTING ANY SNOW
ACCUMULATION THOUGH. TEMPS WILL BE WELL BELOW NORMAL AND BE IN THE
LOW/MID 40S. IT WILL BE WINDY WITH 35-40KT TO M
FOR TONIGHT...THE RAIN WILL LINGER AS THE SLOW MOVING CLOSED LOW
BEGINS TO MOVE EAST LATE. THERE COULD ONCE AGAIN BE A FEW SNOW
FLAKES MIXING IN AFTER 06Z THU...BUT NO SNOW ACCUMS EXPECTED.
ON THURSDAY...THE AREA SHOULD SLOWLY DRY OUT FROM WEST TO EAST.
THERE COULD EVEN BE SUNSHINE ALONG AND WEST OF THE VALLEY BY
AFTERNOON...AND TEMPS SHOULD RESPOND AND WARM INTO THE MID 50S.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 400 AM CDT WED APR 30 2014
FOR THU NIGHT THROUGH FRI NIGHT...SEVERAL SHORTWAVES WILL ROTATE
THROUGH THE REGION. THERE WILL BE CHANCES FOR MAINLY LIGHT RAIN AT
TIMES...WITH THE BEST WAVE THU NIGHT INTO FRI. THERE COULD ALSO BE
SOME SUNSHINE FRI AFTERNOON...WITH TEMPS INTO THE MID 50S FOR MOST
AREAS.
FOR SAT THROUGH TUE...THE LONG WAVE TRANSITIONS FROM A HIGH
AMPLITUDE PATTERN AT THE BEGINNING OF THE PERIOD TO A ZONAL
PATTERN BY THE END OF THE PERIOD. GIVEN THE ZONAL FLOW TEMPERATURES
WILL STAY BELOW NORMAL. WARM ADVECTION PRECIP EXPECTED IN THE SUN
NIGHT THROUGH WED TIME FRAME.
THE GFS WAS FASTER THAN THE ECWMF THROUGH THE PERIOD AND WILL BE
PREFERRED. PRECIP WAS TAKEN OUT SAT NIGHT.
LITTLE CHANGE TO TEMPS FOR THE PERIOD EXCEPT A COUPLE DEGREES HIGHER
FOR TUE IN THE SOUTHERN VALLEY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 645 AM CDT WED APR 30 2014
EXPECT IFR CONDITIONS EAST AND MVFR/IFR CONDITIONS FURTHER WEST
TODAY. THERE WILL BE LIGHT RAIN FROM TIME TO TIME...WITH NORTHERLY
WINDS GUSTING OVER 25KT AT TIMES THIS AFTERNOON.
&&
.HYDROLOGY...
UPDATED AT 935 AM CDT WED APR 30 2014
WAHPETON GAGE HAS CRESTED JUST BELOW MODERATE FLOOD STAGE AND
ABERCROMBIE APPEARS NEAR CREST AT THIS TIME.
OTHERWISE...MODERATE FLOODING CONTINUES TO BE FORECAST AT
FARGO. MINOR FLOODING CONTINUES FOR THE BUFFALO RIVER WHILE SITES
ALONG THE LOWER SHEYENNE RIVER AND LOWER MAPLE RIVER ARE AT
BANKFUL STAGE.
LIGHT RAIN SHOWERS WILL OCCUR TODAY AND FOR THE NEXT SEVERAL DAYS
...BUT RAINFALL AMOUNTS WILL GENERALLY BE ONLY A FEW HUNDREDTHS OF
AN INCH EACH DAY. MINOR FLOODING AT POINTS FROM GRAND FORKS NORTHWARD
ARE EXPECTED (MODERATE AT OSLO).
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...GUST
SHORT TERM...DK
LONG TERM...HOPPES/DK
AVIATION...ROGERS/DK
HYDROLOGY...JK/HOPPES
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
739 AM EDT WED APR 30 2014
.SYNOPSIS...
A WET AND STORMY PATTERN WILL PERSIST ACROSS THE AREA THROUGH
WEDNESDAY. THE PATTERN WILL BEGIN TO CHANGE BY THE END OF THE WORK
WEEK WITH COOLER AND DRIER HIGH PRESSURE MOVING OVER THE REGION AND
REMAINING IN PLACE OVER THE WEEKEND. BEYOND THAT...BROAD UPPER
RIDGING WILL PREVAIL THROUGH MID WEEK LEADING TO MODERATING
TEMPERATURES AND LOW PRECIPITATION CHANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 730 AM EDT...WILL HAVE TO GIVE SERIOUS THOUGHT TO ENDING THE
FLASH FLOOD WATCH AT SOME POINT TODAY...POSSIBLY THIS MORNING.
CLEARLY...THE ERN GULF COAST CONVECTION HAS HAD A MAJOR IMPACT ON
BOTH QPF AND CONVECTIVE INITIATION ACROSS OUR AREA. WE FEEL THE
IMPACT HAS BEEN TWOFOLD. FIRST...MOISTURE TRANSPORT FROM THE GULF OF
MEXICO HAS BEEN SEVERELY HAMPERED. SECOND...AND PERHAPS THIS IS LESS
WELL DOCUMENTED...THE CONSTANT BLOW OFF CIRRUS SHIELD FROM THE
CONVECTION HAS HAD A STABILIZING AFFECT ACROSS CENTRAL GA AND THE
FORECAST AREA. SCATTERED CONVECTION REMAINS POSSIBLE...SO WILL ONLY
END THE WATCH WHEN A BETTER CONSENSUS DEVELOPS AMONG THE CONVECTION
ALLOWING MODELS THAT FLOODING WILL NOT OCCUR. AT ANY RATE...THE MAIN
STEM RIVERS NOW APPEAR IN GOOD SHAPE AND FORECAST CRESTS WILL BE
LOWERED WITH THE MORNING FORECAST.
AS OF 500 AM EDT...MADE SOME SIGFNT CHANGES TO LOWER THE POP/QPF
GRIDS OVER THE NEXT 3 HRS. THE WEDGE BNDRY HAS ERODED FOR THE MOST
PART...LEAVING LITTLE FORCING FOR CONTINUED OR WIDESPREAD CONVEC.
THERE IS STILL AN ACTIVE BNDRY NEAR CLT WITH STORMS PRODUCING UP TO
AN INCH OF RAIN IN THE PAST HR OR TWO. NO IMMEDIATE FLOOD
THREATS...BUT THE CLT ARE WILL NEED TO BE MONITORED CLOSELY THIS
AFTERNOON FOR POSSIBLE HEAVY RAINFALL PRODUCING FLOODING CONDS.
PRECIPITATION WITH SOME THUNDER CONTINUES TO DEVELOP ALONG A WEDGE
BNDRY BISECTING THE CWFA. THESE CELLS ARE REMAINING FAIRLY WEAK AND
SHALLOW WITH AN H7 INVERSION KEEPING THINGS IN CHECK. PRECIP AMOUNTS
THE PAST FEW HRS HAS REMAINED LOW END WITH THE HIGHER RATES UP TO
0.5 IN/HR ACROSS THE ERN ZONES WHERE THE FLOW IS ALSO ALIGNING ALONG
THE RIDGE BNDRY AND ALLOWING SOME TRAINING.
WITH THE GOM COASTAL CONVECTION SIGFNTLY LIMITING THE AMOUNT OF
MOISTURE FLUX TO THE CWFA...QPF AMOUNTS WERE AGAIN ADJ DOWN USING A
CONSENSUS OF MOS/DYN MODELS. THE HRRR CONTINUES TO INITIATE AND
CAPTURE THE LOWER QPF SCENARIO MUCH BETTER THAN THE HIRES NAM AND
WRF MODELS...SO IT WAS BLENDED WITH MORE WEIGHT WITH OFFICIAL. THE
FLASH FLOOD WATCH WILL BE CONTINUED AS AFTERNOON CONVECTION SHOULD
BE RATHER STOUT RAIN PRODUCERS POSSIBLY PRODUCING LOCALIZED
STREAM/RIVER FLOODING AS LLVL MOISTURE POOLS ALONG AND AHEAD OF AN
APPROACHING COLD FRONT. THE THREAT OF SEVERE TSTMS IS ALSO LOOKING
GOOD IF ENOUGH INSTABILITY CAN BE REALIZED. MODEL SOUNDINGS SHOW
SBCAPE VALUES ACROSS THE NON/MTNS OF AROUND 1200 J/KG WITH VERY GOOD
E/SHEAR AROUND 55 KTS AND H92/H5 CROSSOVER WINDS INDICATING THE
POTENTIAL FOR ROTATING LONG LIVED STORMS.
THE FRONT SHOULD CROSS EAST OF THE AREA OVERNIGHT AND ALLOW A DEEP
DRYING MIX ACROSS THE WRN ZONES. HOWEVER...SCT/ISOL SHOWERS WILL
LIKELY LINGER THROUGH DAYBREAK OVER THE ERN PART OF THE CWFA. THE
ULVL DYNAMICS WILL REMAIN WELL NE OF THE AREA ASSOCIATED WITH THE
OCCLUDED LOW...SO NOT MUCH OF A WIND SHIFT WILL ACCOMPANY THE FROPA
OUTSIDE THE MTNS. MAX AND MIN TEMPS WILL BE RIGHT AROUND SEASONAL
LEVELS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 200 AM EDT WEDNESDAY...ROTATING UPPER VORTEX WILL EJECT TO THE
NORTHEAST ALLOWING THE UPPER FLOW TO OPEN UP IN THE FORM A BROAD
LONGWAVE POSITIVELY TILTED TROF. AT THE SURFACE...FRONTAL BOUNDARY
WILL HAVE PUSHED EAST INTO THE MIDLANDS/LOWCOUNTRY OF SC AND THE
COASTAL PLAINS OF NC. MODELS CONTINUE TO HINT AT SLOWING DOWN OF
THE FRONT AS IT APPROACHES THE COAST LATER IN THE DAY THURSDAY
POTENTIALLY STALLING JUST OFFSHORE INTO FRIDAY. FORECAST WILL
FEATURE CHANCE POPS TAPERING DOWN THROUGH MID/LATE THURSDAY MORNING
SOUTH OF INTERSTATE 85...WITH SLIGHT CHANCE POPS ACROSS THE CENTRAL
AND NORTHERN MOUNTAINS OF WESTERN NC DUE TO WEAK UPSLOPE POTENTIAL.
BEYOND THAT POPS WILL TAPER DOWN BELOW MENTIONABLE LEVELS FOR THE
OVERNIGHT INTO FRIDAY. DECIDED TO CONTINUE WITH PREVIOUS FORECAST
OF SLIGHT CHANCE POPS SOUTH OF INTERSTATE 85 ON FRIDAY AFTERNOON AS
RIGHT REAR ENTRANCE REGION OF A 110KT JET MAX WILL PROVIDE
SUBSTANTIAL LIFT TO SUPPORT LIGHT SHOWERS IF A WEAK SURFACE WAVE
DEVELOPS ALONG THE STALLED FRONTAL BOUNDARY AS GUIDANCE SUGGESTS.
LASTLY...POPS WILL DROP QUICKLY INTO FRIDAY EVENING AS THE UPPER
TROF AXIS AND ABOVE MENTIONED JET MAX ADVECT NORTHEAST ALLOWING FOR
HEIGHTS TO RISE ACROSS THE SOUTHEAST IN ADDITION TO BUILDING HIGH
PRESSURE AT THE SURFACE. TEMPERATURES THROUGH THE SHORT TERM WILL
COOL GRADUALLY WITH BELOW NORMAL HIGHS FORECAST FOR BOTH THURSDAY
AND FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 230 AM EDT WEDNESDAY...THE MEDIUM RANGE PERIOD INITIALIZES
SATURDAY MORNING WITH A WEAK UPPER WAVE PASSING THROUGH THE NORTHERN
GULF AND SURFACE HIGH PRESSURE BUILDING ACROSS THE SOUTHEAST LEADING
TO A DRY PERIOD. SURFACE CYCLOGENESIS OCCURRING OVER SOUTHERN
QUEBEC WILL LIKELY SPREAD A WEAK COLD FRONT ACROSS THE GREAT LAKES
AND OHIO VALLEY REGIONS ON SUNDAY...ALL THE WHILE REMAINING NORTH OF
THE FORECAST AREA. HEIGHTS WILL RISE ACROSS THE SOUTHEAST THROUGH
MIDWEEK AS AN UPPER TROF DIGS OUT WEST AND AN UPPER RIDGE SLIDES
THROUGH THE EASTERN CONUS LEADING TO CONTINUED DRY WEATHER.
TEMPERATURES THROUGH THE MEDIUM RANGE PERIOD WILL INITIALIZE AT
BELOW NORMAL LEVELS FOR SATURDAY...BEFORE GRADUALLY WARMING TO ABOVE
NORMAL NEAR THE END OF THE PERIOD AS THE ABOVE MENTIONED SURFACE
HIGH SLIDES EAST ALLOWING A WARM FRONT TO SPREAD ACROSS THE SOUTHERN
APPALACHIANS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...LOW CONFIDENCE FCST THIS AM FOR THE CLT TAF SITE. HIGH
RES MODELS DEPICT THE SRN STREAM MOVING NORTH AS A WARM FRONT
TDAY...WITH POSSIBLE THUNDER THIS MORNING...SO INCLUDED A TEMPO TSRA
14Z-18Z. LOOKS LIKE THERE WILL BE A BREAK IN LIKELY PRECIP AFT
18Z...BUT THE ATMOS COULD BECOME UNSTABLE ENUF FOR CONVECTIVE
FORMATION DURING THE AFTERNOON. FOR NOW...WENT WITH A DRY TERMINAL
AFT 18Z WITH PROB30 TSRA RETURNING THIS EVENING ASSOCIATED WITH
APPROACHING COLD FRONT. CIGS SHOULD REMAIN IN THE MVFR
RANGE...POSSIBLY BREAKING OUT VFR OR SCT EARLY AFTERNOON. WINDS
BECOME SOUTH AND GUSTY THIS AFTERNOON WITH WARM FRONT PASSAGE.
ELSEWHERE...EXPECT IFR RANGE CIGS AND MVFR/IFR VSBYS THIS MORNING TO
BECOME MIXED AT TIMES WITH VFR CONDS ASSOCIATED WITH SCOURING -SHRA.
A TRANSITION FROM SHRA TO SCT/NUM TSTMS IS IN STORE LATE MORNING TO
EARLY AFTERNOON. A BREAK IN PRECIP SHOULD OCCUR EARLY AFTERNOON
THROUGH EARLY EVENING...WITH ISOL SHRA/TSRA ACTIVITY. CIGS WILL
REMAIN MVFR POSSIBLY BREAKING INTO VFR WITH AFTERNOON DRYING. WINDS
WILL BECOME ALIGNED S/LY THIS AFTERNOON WITH MODERATE GUSTS
DEVELOPING IN RESPONSE TO FRONTAL PRESSURE FALLS.
OUTLOOK...DRYING FROM THE WEST IS EXPECTED FROM WED NIGHT THROUGH
THE WEEKEND.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-11Z
KCLT HIGH 80% MED 74% HIGH 86% HIGH 80%
KGSP HIGH 85% MED 79% HIGH 82% HIGH 95%
KAVL HIGH 84% HIGH 80% MED 79% HIGH 86%
KHKY HIGH 86% HIGH 86% HIGH 89% MED 70%
KGMU HIGH 91% HIGH 83% HIGH 92% HIGH 97%
KAND HIGH 100% HIGH 82% HIGH 93% HIGH 81%
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 THROUGH THIS EVENING FOR GAZ010-017-018-026-
028-029.
NC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR NCZ033-035>037-
048>053-056>059-062>065-068>072-082-501>510.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ001>014-019.
&&
$$
SYNOPSIS...CDG
NEAR TERM...HG/SBK
SHORT TERM...CDG
LONG TERM...CDG
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
652 AM EDT WED APR 30 2014
.SYNOPSIS...
A WET AND STORMY PATTERN WILL PERSIST ACROSS THE AREA THROUGH
WEDNESDAY. THE PATTERN WILL BEGIN TO CHANGE BY THE END OF THE WORK
WEEK WITH COOLER AND DRIER HIGH PRESSURE MOVING OVER THE REGION AND
REMAINING IN PLACE OVER THE WEEKEND. BEYOND THAT...BROAD UPPER
RIDGING WILL PREVAIL THROUGH MID WEEK LEADING TO MODERATING
TEMPERATURES AND LOW PRECIPITATION CHANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 500 AM EDT...MADE SOME SIGFNT CHANGES TO LOWER THE POP/QPF
GRIDS OVER THE NEXT 3 HRS. THE WEDGE BNDRY HAS ERODED FOR THE MOST
PART...LEAVING LITTLE FORCING FOR CONTINUED OR WIDESPREAD CONVEC.
THERE IS STILL AN ACTIVE BNDRY NEAR CLT WITH STORMS PRODUCING UP TO
AN INCH OF RAIN IN THE PAST HR OR TWO. NO IMMEDIATE FLOOD
THREATS...BUT THE CLT ARE WILL NEED TO BE MONITORED CLOSELY THIS
AFTERNOON FOR POSSIBLE HEAVY RAINFALL PRODUCING FLOODING CONDS.
PRECIPITATION WITH SOME THUNDER CONTINUES TO DEVELOP ALONG A WEDGE
BNDRY BISECTING THE CWFA. THESE CELLS ARE REMAINING FAIRLY WEAK AND
SHALLOW WITH AN H7 INVERSION KEEPING THINGS IN CHECK. PRECIP AMOUNTS
THE PAST FEW HRS HAS REMAINED LOW END WITH THE HIGHER RATES UP TO
0.5 IN/HR ACROSS THE ERN ZONES WHERE THE FLOW IS ALSO ALIGNING ALONG
THE RIDGE BNDRY AND ALLOWING SOME TRAINING.
WITH THE GOM COASTAL CONVECTION SIGFNTLY LIMITING THE AMOUNT OF
MOISTURE FLUX TO THE CWFA...QPF AMOUNTS WERE AGAIN ADJ DOWN USING A
CONSENSUS OF MOS/DYN MODELS. THE HRRR CONTINUES TO INITIATE AND
CAPTURE THE LOWER QPF SCENARIO MUCH BETTER THAN THE HIRES NAM AND
WRF MODELS...SO IT WAS BLENDED WITH MORE WEIGHT WITH OFFICIAL. THE
FLASH FLOOD WATCH WILL BE CONTINUED AS AFTERNOON CONVECTION SHOULD
BE RATHER STOUT RAIN PRODUCERS POSSIBLY PRODUCING LOCALIZED
STREAM/RIVER FLOODING AS LLVL MOISTURE POOLS ALONG AND AHEAD OF AN
APPROACHING COLD FRONT. THE THREAT OF SEVERE TSTMS IS ALSO LOOKING
GOOD IF ENOUGH INSTABILITY CAN BE REALIZED. MODEL SOUNDINGS SHOW
SBCAPE VALUES ACROSS THE NON/MTNS OF AROUND 1200 J/KG WITH VERY GOOD
E/SHEAR AROUND 55 KTS AND H92/H5 CROSSOVER WINDS INDICATING THE
POTENTIAL FOR ROTATING LONG LIVED STORMS.
THE FRONT SHOULD CROSS EAST OF THE AREA OVERNIGHT AND ALLOW A DEEP
DRYING MIX ACROSS THE WRN ZONES. HOWEVER...SCT/ISOL SHOWERS WILL
LIKELY LINGER THROUGH DAYBREAK OVER THE ERN PART OF THE CWFA. THE
ULVL DYNAMICS WILL REMAIN WELL NE OF THE AREA ASSOCIATED WITH THE
OCCLUDED LOW...SO NOT MUCH OF A WIND SHIFT WILL ACCOMPANY THE FROPA
OUTSIDE THE MTNS. MAX AND MIN TEMPS WILL BE RIGHT AROUND SEASONAL
LEVELS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 200 AM EDT WEDNESDAY...ROTATING UPPER VORTEX WILL EJECT TO THE
NORTHEAST ALLOWING THE UPPER FLOW TO OPEN UP IN THE FORM A BROAD
LONGWAVE POSITIVELY TILTED TROF. AT THE SURFACE...FRONTAL BOUNDARY
WILL HAVE PUSHED EAST INTO THE MIDLANDS/LOWCOUNTRY OF SC AND THE
COASTAL PLAINS OF NC. MODELS CONTINUE TO HINT AT SLOWING DOWN OF
THE FRONT AS IT APPROACHES THE COAST LATER IN THE DAY THURSDAY
POTENTIALLY STALLING JUST OFFSHORE INTO FRIDAY. FORECAST WILL
FEATURE CHANCE POPS TAPERING DOWN THROUGH MID/LATE THURSDAY MORNING
SOUTH OF INTERSTATE 85...WITH SLIGHT CHANCE POPS ACROSS THE CENTRAL
AND NORTHERN MOUNTAINS OF WESTERN NC DUE TO WEAK UPSLOPE POTENTIAL.
BEYOND THAT POPS WILL TAPER DOWN BELOW MENTIONABLE LEVELS FOR THE
OVERNIGHT INTO FRIDAY. DECIDED TO CONTINUE WITH PREVIOUS FORECAST
OF SLIGHT CHANCE POPS SOUTH OF INTERSTATE 85 ON FRIDAY AFTERNOON AS
RIGHT REAR ENTRANCE REGION OF A 110KT JET MAX WILL PROVIDE
SUBSTANTIAL LIFT TO SUPPORT LIGHT SHOWERS IF A WEAK SURFACE WAVE
DEVELOPS ALONG THE STALLED FRONTAL BOUNDARY AS GUIDANCE SUGGESTS.
LASTLY...POPS WILL DROP QUICKLY INTO FRIDAY EVENING AS THE UPPER
TROF AXIS AND ABOVE MENTIONED JET MAX ADVECT NORTHEAST ALLOWING FOR
HEIGHTS TO RISE ACROSS THE SOUTHEAST IN ADDITION TO BUILDING HIGH
PRESSURE AT THE SURFACE. TEMPERATURES THROUGH THE SHORT TERM WILL
COOL GRADUALLY WITH BELOW NORMAL HIGHS FORECAST FOR BOTH THURSDAY
AND FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 230 AM EDT WEDNESDAY...THE MEDIUM RANGE PERIOD INITIALIZES
SATURDAY MORNING WITH A WEAK UPPER WAVE PASSING THROUGH THE NORTHERN
GULF AND SURFACE HIGH PRESSURE BUILDING ACROSS THE SOUTHEAST LEADING
TO A DRY PERIOD. SURFACE CYCLOGENESIS OCCURRING OVER SOUTHERN
QUEBEC WILL LIKELY SPREAD A WEAK COLD FRONT ACROSS THE GREAT LAKES
AND OHIO VALLEY REGIONS ON SUNDAY...ALL THE WHILE REMAINING NORTH OF
THE FORECAST AREA. HEIGHTS WILL RISE ACROSS THE SOUTHEAST THROUGH
MIDWEEK AS AN UPPER TROF DIGS OUT WEST AND AN UPPER RIDGE SLIDES
THROUGH THE EASTERN CONUS LEADING TO CONTINUED DRY WEATHER.
TEMPERATURES THROUGH THE MEDIUM RANGE PERIOD WILL INITIALIZE AT
BELOW NORMAL LEVELS FOR SATURDAY...BEFORE GRADUALLY WARMING TO ABOVE
NORMAL NEAR THE END OF THE PERIOD AS THE ABOVE MENTIONED SURFACE
HIGH SLIDES EAST ALLOWING A WARM FRONT TO SPREAD ACROSS THE SOUTHERN
APPALACHIANS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...LOW CONFIDENCE FCST THIS AM FOR THE CLT TAF SITE. HIGH
RES MODELS DEPICT THE SRN STREAM MOVING NORTH AS A WARM FRONT
TDAY...WITH POSSIBLE THUNDER THIS MORNING...SO INCLUDED A TEMPO TSRA
14Z-18Z. LOOKS LIKE THERE WILL BE A BREAK IN LIKELY PRECIP AFT
18Z...BUT THE ATMOS COULD BECOME UNSTABLE ENUF FOR CONVECTIVE
FORMATION DURING THE AFTERNOON. FOR NOW...WENT WITH A DRY TERMINAL
AFT 18Z WITH PROB30 TSRA RETURNING THIS EVENING ASSOCIATED WITH
APPROACHING COLD FRONT. CIGS SHOULD REMAIN IN THE MVFR
RANGE...POSSIBLY BREAKING OUT VFR OR SCT EARLY AFTERNOON. WINDS
BECOME SOUTH AND GUSTY THIS AFTERNOON WITH WARM FRONT PASSAGE.
ELSEWHERE...EXPECT IFR RANGE CIGS AND MVFR/IFR VSBYS THIS MORNING TO
BECOME MIXED AT TIMES WITH VFR CONDS ASSOCIATED WITH SCOURING -SHRA.
A TRANSITION FROM SHRA TO SCT/NUM TSTMS IS IN STORE LATE MORNING TO
EARLY AFTERNOON. A BREAK IN PRECIP SHOULD OCCUR EARLY AFTERNOON
THROUGH EARLY EVENING...WITH ISOL SHRA/TSRA ACTIVITY. CIGS WILL
REMAIN MVFR POSSIBLY BREAKING INTO VFR WITH AFTERNOON DRYING. WINDS
WILL BECOME ALIGNED S/LY THIS AFTERNOON WITH MODERATE GUSTS
DEVELOPING IN RESPONSE TO FRONTAL PRESSURE FALLS.
OUTLOOK...DRYING FROM THE WEST IS EXPECTED FROM WED NIGHT THROUGH
THE WEEKEND.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-11Z
KCLT HIGH 80% MED 74% HIGH 86% HIGH 80%
KGSP HIGH 85% MED 79% HIGH 82% HIGH 95%
KAVL HIGH 84% HIGH 80% MED 79% HIGH 86%
KHKY HIGH 86% HIGH 86% HIGH 89% MED 70%
KGMU HIGH 91% HIGH 83% HIGH 92% HIGH 97%
KAND HIGH 100% HIGH 82% HIGH 93% HIGH 81%
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 THROUGH THIS EVENING FOR GAZ010-017-018-026-
028-029.
NC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR NCZ033-035>037-
048>053-056>059-062>065-068>072-082-501>510.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ001>014-019.
&&
$$
SYNOPSIS...CDG/JPT
NEAR TERM...SBK
SHORT TERM...CDG
LONG TERM...CDG
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
417 PM EDT WED APR 30 2014
.SYNOPSIS...
THE SLOW MOVING FRONTAL SYSTEM WILL REMAIN IN THE FORECAST AREA
INTO THURSDAY. THE FRONT WILL BE NEAR THE COAST THURSDAY NIGHT AND
FRIDAY. DEEPER MOISTURE AHEAD OF THE FRONT HAS SHIFTED EAST OF THE
FORECAST AREA.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 2015Z...LAKE WIND ADVISORY HAS BEEN CANCELLED. WEAK SURFACE PRESSURE
GRADIENT ACROSS THE AREA REST OF THE AFTERNOON. THE SLOW MOVING
FRONT WILL BE IN THE FORECAST AREA TONIGHT. LATEST RAP AND LAPS
ANALYSIS INDICATE WEAK MID LEVEL CAP AND HIGH LFC. HRRR SHOWS
LIMITED COVERAGE AS FRONT MOVES INTO THE AREA. UPSTREAM RADAR
ANALYSIS AT 20Z NOT IMPRESSIVE. CONVERGENCE ASSOCIATED WITH THE
FRONT MAY SUPPORT SHOWERS AND THUNDERSTORMS BUT EXPECT LITTLE
COVERAGE WITH DEEPER MOISTURE EAST OF THE REGION. CLOUDINESS AND
MIXING WILL HOLD UP TEMPERATURES. EXPECT LOWS MAINLY IN THE MIDDLE
60S AS INDICATED BY THE GFS AND NAM MOS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
THE NAM AND GFS KEEP THE FRONT IN THE FORECAST AREA THURSDAY BUT
DEEPER MOISTURE IS FARTHER EAST. THE GFS AND NAM MOS SUPPORT CHANCE
POPS...MAINLY IN THE EAST SECTION. THE MODELS INDICATE A LITTLE
MORE DRYING THURSDAY NIGHT...BUT SOME INCREASE IN MOISTURE
ASSOCIATED WITH A WAVE ALONG THE STALLED FRONT FRIDAY. THE
GUIDANCE CONSENSUS SUPPORTS CHANCE POPS IN THE EAST PART FRIDAY
INTO FRIDAY NIGHT. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE
FORECAST.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE GFS AND ECMWF INDICATE A DRY PATTERN DURING THE MEDIUM-RANGE
PERIOD. MOISTURE ASSOCIATED WITH THE OFFSHORE FRONT APPEARS TO BE
EAST OF THE AREA EARLY IN THE PERIOD. THE MODELS DISPLAY MOISTURE
ASSOCIATED WITH ANOTHER FRONT STAYING MAINLY NORTH OF THE AREA
LATER IN THE PERIOD. THE GFS ENSEMBLE MEAN POPS ARE LESS THAN 10
PERCENT THROUGH THE PERIOD.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS HAVE RETURNED TO ALL OF THE TAF SITES THIS AFTERNOON.
RADAR TRENDS THIS AFTERNOON SHOW THE MAIN CONCERN AREA FOR
SHOWERS/THUNDERSTORMS WILL BE ALONG THE EASTERN PORTION/COAST OF THE
STATE. A SECONDARY WEAKER LINE OF MAINLY SHOWERS IS ASSOCIATE WITH
THE COLD FRONT STRETCHING FROM EASTERN KY SOUTHWARD INTO NORTHEAST
AL. SATELLITE/OBS INDICATE MAINLY MID/HIGH CLOUDS ACROSS THE
MIDLANDS AND CSRA THIS AFTERNOON. EXPECT THIS TREND TO CONTINUE
THROUGH THE REMAINDER OF THE AFTERNOON AND EVENING HOURS. THERE WILL
BE A CHANCE OF A SHOWER/THUNDERSTORM OVERNIGHT AS THE COLD FRONT
MOVES INTO THE UPSTATE JUST BEFORE MIDNIGHT THEN INTO THE
MIDLANDS/CSRA BETWEEN 4 AM AND 7 AM. THE FRONT WILL MOVE EAST OF THE
AREA BY MID/LATE THURSDAY MORNING. WITH CONFIDENCE LOW AT THIS
TIME...WILL NOT MENTION ANY SHRA/TSRA IN TAFS...BUT WILL INCLUDE A
PERIOD OF MVFR CEILINGS WITH PASSAGE OF FRONT. IT WILL BE A BIT
BREEZY FOR THE REMAINDER OF THE AFTERNOON WITH MAINLY
SOUTHEAST/SOUTH WINDS 10 TO 15 MPH WITH A FEW GUST UP TO 20 TO 25
MPH. A LOW LEVEL 30-35 KT JET OVERNIGHT WILL HELP KEEP WINDS AROUND
6 TO 10 KTS. BY THURSDAY MORNING...CONDITIONS SHOULD BEGIN TO
IMPROVE AND WINDS WILL BECOME MORE WESTERLY AND BREEZY WITH VFR
CONDITIONS RETURNING BY 14Z.
.EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE DUE TO
SHOWERS/FOG/LOWER CEILINGS AS A SYSTEM MOVES SOUTH OF THE REGION
THURSDAY NIGHT INTO FRIDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
601 PM CDT WED APR 30 2014
.DISCUSSION...
00Z TAF ISSUANCE.
&&
.AVIATION...
WSW TO ENE STREAMING SHRA OVER THE COASTAL WATERS ACROSS LOWER
ACADIANA EXPECTED TO REMAIN S OF LFT/ARA THIS EVENING AND OVERNIGHT.
THUS...ONLY MID LEVEL CLOUDINESS EXPECTED FOR S SITES WITH VFR
EXPECTED. NNW WINDS 6-8 KTS THIS EVENING WILL DIMINISH A BIT
TOWARDS DAYBREAK...THEN INCREASE FROM THE NNE ~10-12 KTS WITH
GUSTS TO 20 KTS AFTER 15Z THU.
DML
&&
.PREV DISCUSSION... /ISSUED 335 PM CDT WED APR 30 2014/
DISCUSSION...
UPPER AIR ANALYSIS INDICATES LARGE SPRAWLING CYCLONE CENTERED OVER
THE MIDWEST THIS AFTERNOON. COLD FRONT HAS NOW PAST THE COASTAL
WATERS WITH TEMPERATURES OVER THE AREA THIS AFTERNOON IN THE LOWER
70S TO UPPER 60S. RADAR IS CONTINUING TO SHOW SOME
SHOWERS/SPRINKLE OVER THE COASTAL WATER INTO SOUTH CENTRAL
LOUISIANA WITH A FEW EMBEDDED THUNDERSTORMS JUST BEYOND THE
COASTAL WATERS. THIS ACTIVITY IS LIKELY THE RESULT OF JET STREAK
AND ASSOCIATED SHORT WAVE IN THE SOUTHERN BRANCH OF THE JET
STREAM.
GUIDANCE HAS BEEN POOR WITH THE ELEVATED SHOWERS AND THUNDERSTORMS
OVER THE COASTAL WATERS TODAY...HOWEVER THE LAST SEVERAL RUNS OF
THE HRRR HAS PICKED UP ON IT AND CONTINUES TO SHOW ACTIVITY ACROSS
THE COASTAL WATERS AND WITH SOME COMING ONSHORE IN IBERIA...ST.
MARY AND ST. MARTIN PARISHES FOR THE NEXT FEW HOURS BEFORE IT
FINALLY DISSIPATES/MOVES EAST.
WILL MAINTAIN SOME MENTIONABLE POPS IN THE SOUTHEAST COASTAL
WATERS FOR THE NEXT 24-36 HOURS AS THIS AREA REMAINS IN FAVORABLE
AREA OF THE JET AND IMPULSES RIDING ACROSS IN IT. OTHERWISE AREAS
INLAND LOOK DRY THROUGH THE REMAINDER OF THE FORECAST.
COOL TEMPERATURES TONIGHT...ESPECIALLY INTERIOR SOUTHEAST TEXAS
AND WEST CENTRAL LOUISIANA WITH TEMPERATURES GETTING INTO 45 TO 50
RANGE! TEMPERATURES WILL GRADUALLY WARM THROUGH THE PERIOD BACK TO
NEAR SEASONAL NORMALS BY THE WEEKEND.
THE ONLY OTHER CHANGE WAS TO ADD SCEC TO THE COASTAL WATERS
TONIGHT AND FRIDAY MORNING AS WINDS WILL INCREASE AGAIN OVERNIGHT
AS THE BOUNDARY LAYER DESTABILIZES OVER THE RELATIVELY WARMER GULF
WATERS.
27
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 51 75 53 78 56 / 10 10 10 10 10
KBPT 52 76 55 78 57 / 10 10 10 10 10
KAEX 47 73 51 77 51 / 0 0 10 10 10
KLFT 51 73 55 76 56 / 10 10 10 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT EXERCISE CAUTION FROM 1 AM CDT THURSDAY THROUGH
THURSDAY AFTERNOON FOR THE FOLLOWING ZONES: COASTAL WATERS
FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM...COASTAL
WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM...
COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL
CITY LA OUT 20 NM...WATERS FROM INTRACOASTAL CITY TO
CAMERON LA FROM 20 TO 60 NM...WATERS FROM CAMERON LA TO
HIGH ISLAND TX FROM 20 TO 60 NM...WATERS FROM LOWER
ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
335 PM CDT WED APR 30 2014
.DISCUSSION...
UPPER AIR ANALYSIS INDICATES LARGE SPRAWLING CYCLONE CENTERED OVER
THE MIDWEST THIS AFTERNOON. COLD FRONT HAS NOW PAST THE COASTAL
WATERS WITH TEMPERATURES OVER THE AREA THIS AFTERNOON IN THE LOWER
70S TO UPPER 60S. RADAR IS CONTINUING TO SHOW SOME
SHOWERS/SPRINKLE OVER THE COASTAL WATER INTO SOUTH CENTRAL
LOUISIANA WITH A FEW EMBEDDED THUNDERSTORMS JUST BEYOND THE
COASTAL WATERS. THIS ACTIVITY IS LIKELY THE RESULT OF JET STREAK
AND ASSOCIATED SHORT WAVE IN THE SOUTHERN BRANCH OF THE JET
STREAM.
GUIDANCE HAS BEEN POOR WITH THE ELEVATED SHOWERS AND THUNDERSTORMS
OVER THE COASTAL WATERS TODAY...HOWEVER THE LAST SEVERAL RUNS OF
THE HRRR HAS PICKED UP ON IT AND CONTINUES TO SHOW ACTIVITY ACROSS
THE COASTAL WATERS AND WITH SOME COMING ONSHORE IN IBERIA...ST.
MARY AND ST. MARTIN PARISHES FOR THE NEXT FEW HOURS BEFORE IT
FINALLY DISSIPATES/MOVES EAST.
WILL MAINTAIN SOME MENTIONABLE POPS IN THE SOUTHEAST COASTAL
WATERS FOR THE NEXT 24-36 HOURS AS THIS AREA REMAINS IN FAVORABLE
AREA OF THE JET AND IMPULSES RIDING ACROSS IN IT. OTHERWISE AREAS
INLAND LOOK DRY THROUGH THE REMAINDER OF THE FORECAST.
COOL TEMPERATURES TONIGHT...ESPECIALLY INTERIOR SOUTHEAST TEXAS
AND WEST CENTRAL LOUISIANA WITH TEMPERATURES GETTING INTO 45 TO 50
RANGE! TEMPERATURES WILL GRADUALLY WARM THROUGH THE PERIOD BACK TO
NEAR SEASONAL NORMALS BY THE WEEKEND.
THE ONLY OTHER CHANGE WAS TO ADD SCEC TO THE COASTAL WATERS
TONIGHT AND FRIDAY MORNING AS WINDS WILL INCREASE AGAIN OVERNIGHT
AS THE BOUNDARY LAYER DESTABILIZES OVER THE RELATIVELY WARMER GULF
WATERS.
27
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 75 51 75 53 78 / 0 10 10 10 10
KBPT 76 52 76 55 78 / 0 10 10 10 10
KAEX 71 47 73 51 77 / 0 0 0 10 10
KLFT 74 51 73 55 76 / 20 10 10 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT EXERCISE CAUTION FROM 1 AM CDT THURSDAY THROUGH
THURSDAY AFTERNOON FOR THE FOLLOWING ZONES: COASTAL WATERS
FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM...COASTAL
WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM...
COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL
CITY LA OUT 20 NM...WATERS FROM INTRACOASTAL CITY TO
CAMERON LA FROM 20 TO 60 NM...WATERS FROM CAMERON LA TO
HIGH ISLAND TX FROM 20 TO 60 NM...WATERS FROM LOWER
ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM.
&&
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.LAKECHARLES.GOV
WWW.TWITTER.COM/NWSLAKECHARLES
WWW.YOUTUBE.COM/NWSLAKECHARLES
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
458 PM EDT WED APR 30 2014
.SYNOPSIS...
HIGH PRESSURE WILL SHIFT OFFSHORE TONIGHT LOW PRESSURE TO APPROACH
FROM THE WEST. LOW PRESSURE WILL CROSS THE REGION LATE TONIGHT
INTO FRIDAY. UNSETTLED WEATHER WITH UNSEASONABLY COOL
TEMPERATURES WILL CONTINUE OVER THE WEEKEND AS UPPER LEVEL
DISTURBANCES SPREAD CLOUDS AND SHOWERS OVER THE REGION. A
STRONGER UPPER LEVEL SYSTEM PUSHES A COLD FRONT THROUGH SUNDAY
WITH THE UPPER LEVEL SYSTEM HANGING AROUND INTO MONDAY. HIGH
PRESSURE SLOWLY BUILDS IN FROM THE WEST ON TUESDAY AS THE UPPER
LEVEL SYSTEM SLOWLY MOVES OFF TO THE EAST.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
UPDATE...WILL BACK OF TIMING OF HIGH POP A LITTLE MORE. RNFL
HAVING HARD TIME ADVANCING EWD AS RIDGE AXIS SLOWLY DEPARTS.
STEADY PCPN NOW JUST MOVING INTO SW NH...AND WILL SLOWLY CREEP EWD
THRU THE EVENING. LATEST HRRR AND 12Z CMC REGIONAL HAVE A GOOD
HANDLE ON CURRENT PCPN...SO HAVE BLENDED THOSE INTO THE PREVIOUS
FORECAST.
PREVIOUS DISCUSSION...PORTSMOUTH AND ENVIRONS ARE ALREADY SEEING
LIGHT SHOWERS THIS AFTERNOON. ANY PRECIPITATION THAT MOVES EAST
HAS BEEN ERODING IN THE DRIER AIR ASSOCIATED WITH HIGH PRESSURE.
THIS RESILIENT SURFACE HIGH WAS CENTERED OFFSHORE NOW AND SLOWLY
BEING PUSHED EAST. A STRONG LLJ AND INCREASING ISENTROPIC LIFT
WILL EVENTUALLY WIN OUT...ALLOWING THE COLUMN TO SATURATE AND RAIN
TO SPREAD FURTHER INTO NH THIS AFTERNOON AND INTO MAINE LATER THIS
EVENING. HRRR AND NAM12 HAVE A GOOD HANDLE ON THIS PROGRESSION.
INCLUDED HEAVIER WORDING FOR QPF AMOUNTS LATER TONIGHT AS
INTENSITY INCREASES IN CONVECTIVE ELEMENTS. THE WEAK INSTABILITY
PRESENT OVERNIGHT WILL SERVE TO INCREASE BANDS OF CONVECTION WHICH
MAY RESULT IN QUICK THIRD TO HALF INCH AMOUNTS IN A SHORT TIME.
OVERALL STILL EXPECTING BETWEEN 0.75" TO 1.30" THROUGH EARLY
AFTERNOON TOMORROW.
OVERNIGHT LOWS WILL ONLY DROP A INTO THE UPPER 30S AND LOWER 40S
TONIGHT. IN SOME CASES THIS WILL HARDLY BE A CHANGE THANKS TO A
CHILLY DAY.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
IT WILL BE STILL RAINING IN THE MORNING WITH THE HEAVIER
PRECIPITATION CENTERED OVER THE MIDCOAST AND LIGHTER QPF OVER NH.
THE DRY PUNCH BEHIND THIS SYSTEM ARRIVES EARLY TOMORROW AFTERNOON
AND QUICKLY SCOURS OUT MOISTURE WITH GUSTY SW WINDS. WILL KEEP A
CHANCE OF SHOWERS IN THE FORECAST BUT EXPECT TO SEE THESE
EVENTUALLY DISSIPATE WITH SOME BREAKS IN THE CLOUDS AND PEEKS OF
SUN IN THE AFTERNOON. DEPENDING ON HOW FAST THIS OCCURS WE COULD
SEE MID 50S ACROSS THE NORTH. WARM 850MB MB TEMPERATURES AND SW
WINDS WILL HELP MUCH OF NH AND SW MAINE REACH THE 60S AND PERHAPS
EVEN 70 OVER SOUTHERNMOST NH DESPITE CLOUD COVER.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
OVER THE OUTLOOK PERIOD THE MEAN L/WV TROF POSITION INITIALLY REMAINS
ANCHORED OVER THE GREAT LAKES. MEANWHILE...A WEAK SHORT WAVE WILL
EXIT THE REGION FRI WITH ONLY SCT SHWRS MAINLY IN THE MTNS AS A
WLY FLOW DEVELOPS. BY SAT THE L/WV TROF POSITION TO OUR WEST
AMPLIFIES AND ALLOWS AN UPPER LOW TO GRDLY GET CARVED OUT AS IT
PROGRESSES EWD OVER NEW ENGLAND OVER THE WEEKEND AND INTO EARLY
NEXT WEEK. THIS WILL MEAN CONTINUED COOL AND UNSETTLED WX INTO
EARLY NEXT WEEK. TEMPS WILL GENERALLY REMAIN BLO NORMAL.
4TH/5TH PERIODS STAYED CLOSEST TO GFS GUID WITH POPS AND TEMPS.
BEYONE THE 5TH PD STAYED CLOSE TO THE SUPERBLEND GUID WHICH AT THIS
POINT APPEARS REASONABLE OVERALL.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM...VFR/MVFR TODAY WILL LOWER TO IFR/LIFR THIS AFTERNOON
IN NH AND TONIGHT IN MAINE AS SHOWERS SPREAD EAST AND INTENSIFY.
VISIBILITIES WILL BE SLOWER TO DROP BUT AREN`T FORECAST TO DROP
MUCH LOWER THAN IFR. SSW WINDS OF 10G20KT WILL DEVELOP QUICKLY
EARLY TOMORROW MORNING HELPING TO USHER RAIN AND CLOUDS OUT OF THE
REGION. CEILINGS SHOULD IMPROVE BY LATE MORNING.
LONG TERM /FRIDAY THROUGH MONDAY/...PREDOMINATELY MVFR/IFR
CONDITIONS THRU THE LONG TERM FCST PERIOD... WITH THE BEST CHC FOR
IFR ON SUNDAY. CONDITIONS LIKELY TO BE LOWEST ACROSS THE MTNS.
&&
.MARINE...
SHORT TERM...HAVE EXTENDED SMALL CRAFT ADVISORY CONDITIONS THROUGH
TOMORROW EVENING AND INCLUDED PENOBSCOT BAY AS WELL AS WINDS AND
SEAS INCREASE AHEAD OF AN APPROACHING FRONTAL SYSTEM.
LONG TERM /FRIDAY THROUGH MONDAY/...WINDS/SEAS WILL REMAIN BLO SCA
LEVELS.
&&
.FIRE WEATHER...
WIDESPREAD MEASURABLE RAINFALL TONIGHT AND THURSDAY WILL KEEP FIRE
DANGER LOW.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR ANZ150>154.
&&
$$
NEAR TERM...LEGRO
AREA FORECAST DISCUSSION
NWS RALEIGH NC
315 PM EDT WED APR 30 2014
.SYNOPSIS... A LARGE AND VIGOROUS STORM SYSTEM OVER THE MIDWEST WILL
CONTINUE TO BRING UNSETTLED WEATHER TO OUR REGION INTO TONIGHT. A
COLD FRONT WILL MOVE SLOWLY EASTWARD ACROSS THE REGION LATE THURSDAY
INTO THURSDAY NIGHT. DRY AND COOLER WEATHER WILL SPREAD IN FROM THE
WEST FRIDAY AND SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1235 PM WEDNESDAY...
UPDATE... A LARGE MULTICELL COMPLEX HAS FORMED FROM CHARLESTON NORTH
INTO EAST-CENTRAL NC ALONG NUMEROUS MERGING BOUNDARIES. WHILE NOT
COINCIDENT WITH THE BEST DEEP LAYER SHEAR...LOW-LEVEL HELICITY
VALUES MAY STILL SUPPORT SOME EMBEDDED ROTATING STORMS. THE
ORIENTATION OF THE STORM CLUSTERS SUGGEST FLASH FLOODING MAY BE A
BIGGER CONCERN ALONG THE I-95 CORRIDOR...WHERE SEVERAL INCHES OF
RAIN FELL JUST YESTERDAY. WILL BE MAKING SOME EDITS TO THE FORECAST
TO REFLECT THE EASTWARD SHIFT IN FOCUS. -SMITH
THE WEDGE/WARM FRONT CONTINUES TO PUSH NORTHWEST AND IS JUST EAST
IF THE TRIAD...PUTTING NEARLY ALL OF CENTRAL NC IN THE WARM SECTOR
CHARACTERIZED BY LOWER 70 DEWPOINTS. REGIONALLY...THERE IS
WIDESPREAD CLOUD COVER FROM CONVECTION ALONG THE GULF COAST...BUT
SPC MESOANALYSIS SHOWS DESTABILIZATION ALREADY UNDERWAY IN THE WARM
SECTOR...AIDED BY RELATIVELY STEEP MID LEVEL LAPSE RATES BETWEEN
850MB AND 500MB PER THE KGSO 12Z RAOB. LATEST RAP SOUNDINGS SHOW
1000-2000 J/KG MLCAPE IN THE WARM SECTOR BY EARLY AFTERNOON. BULK
SHEAR CONTINUES TO BE STRONG WITH A CORRIDOR OF 45-50KT OVER THE
WESTERN HALF OF THE STATE. LOW-LEVEL HODOGRAPHS REMAIN CYCLONICALLY
CURVED WITH SOUTHEASTERLY SURFACE WINDS AND A 40KT 850MB FLOW OVER
THE CAROLINAS. OUTSIDE OF THE RETREATING WEDGE FRONT...TRIGGERS FOR
CONVECTION ARE A LITTLE MORE NEBULOUS...BUT CONVECTION IS ALREADY
ONGOING OVER CENTRAL SC...WITH A REMNANT MCV OVER THE SAVANNAH RIVER
BASIN. RAP VORT FORECASTS BRING THIS MCV OVER THE SANDHILLS IN THE
17-19Z TIME FRAME. THIS MAY THE MOST OBVIOUS FEATURE UPSTREAM TO
KEY ON...THOUGH CONVECTION SHOULD CONTINUE TO DEVELOP ALONG
DIFFERENTIAL HEATING AND OUTFLOW BOUNDARIES. ALL OF THESE
INGREDIENTS WILL SUPPORT SEVERE STORMS WITH THE POTENTIAL FOR LARGE
HAIL...DAMAGING WINDS AND ISOLATED TORNADOES.
GIVEN THAT THE TRIAD IS CLOSE TO BEING SCOURED OUT FO THE STABLE
AIRMASS...WILL FORECAST HIGHS IN THE 75-83 RANGE.
WHILE RAINFALL HAS BEEN A LITTLE LACK LUSTER OVER THE PIEDMONT...
STORM MOTION TODAY SHOULD STILL SUPPORT TRAINING OF CELLS....AND
AREAS ALONG THE I-95 CORRIDOR WERE MORE THAN PRIMED WITH LAST
EVENINGS RAINFALL. THUS...THE FLASH FLOOD WATCH WILL CONTINUE TODAY.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 315 PM WEDNESDAY...
THE SURFACE COLD FRONT IS EXPECTED TO BE WELL SOUTHEAST OF CENTRAL
NC BY FRIDAY MORNING. WE`LL STILL BE UNDER THE INFLUENCE OF FAST MID
LEVEL FLOW FROM THE SW WITH WEAK PERTURBATIONS TRACKING
NORTHEASTWARD OVER NC FRI... SO EXPECT A VEIL OF MID/HIGH CLOUDS TO
OVERSPREAD CENTRAL/ERN NC FROM LATE MORNING THROUGH FOR MUCH OF THE
AFTERNOON. THE GFS DOES GENERATE A SWATH OF LIGHT PRECIP OVER THE
CENTRAL/ERN CWA FRI... HOWEVER THE LOW LEVELS BELOW 700 MB APPEAR
TOO DRY FOR ANYTHING MORE THAN A QUICK SPRINKLE... SO WILL LEAVE OUT
MEASURABLE POPS. AS THE MID LEVEL TROUGH AXIS APPROACHES FROM THE
WEST LATE FRI INTO FRI NIGHT... ANOTHER SHOT OF ENHANCED CLOUD COVER
IS EXPECTED TO SPREAD OVER THE REGION... PARTICULARLY IN THE
SANDHILLS AND COASTAL PLAIN... BUT AGAIN THE LIMITED FORCING FOR
ASCENT AND LIMITED MOISTURE DEPTH WILL INHIBIT PRECIP DEVELOPMENT.
BELOW NORMAL HIGHS AROUND 70 WITH CLOUDS AND BELOW NORMAL
THICKNESSES. LOWS IN THE UPPER 40S TO LOWER 50S. -GIH
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 1225 PM TUESDAY...
WE SHOULD SEE LINGERING MID-HIGH CLOUDS ESPECIALLY IN THE ERN CWA
THROUGH MUCH OF SAT... AS A POTENT VORTICITY MAX CROSSES GA AND THE
CAROLINAS... BUT DRY/STABLE LOW LEVELS WILL INHIBIT PRECIP
DEVELOPMENT. OTHERWISE... ONCE THE MID LEVEL TROUGH AXIS FINALLY
SHIFTS TO OUR EAST SAT EVENING... EXPECT DRY AND SEASONABLE WEATHER
FOR SUNDAY. A STRONG MID LEVEL CLOSED LOW WILL TRACK ESE ACROSS THE
ST LAWRENCE VALLEY AND NEW ENGLAND SUNDAY... SETTLING JUST OFF THE
NEW ENGLAND COAST MON BEFORE WOBBLING TO THE EAST OR NE LATE TUE
THROUGH WED. TO OUR WEST... BROAD RIDGING OVER THE SW QUARTER OF THE
CONUS ON SUNDAY WILL SHIFT EASTWARD THROUGH THE CENTRAL STATES...
AMPLIFYING AS IT REACHES THE SOUTHEAST STATES BY WED. THIS WILL
RESULT IN GENERALLY FLAT NORTHWESTERLY MID LEVEL FLOW OVER THE
REGION. A BACKDOOR FRONTAL ZONE ORIENTED WEST-EAST ACROSS VA SUNDAY
IS EXPECTED TO DIP SOUTHWARD ACROSS NE NC MONDAY... THEN HOLD MAINLY
STATIONARY IN A NW-SE FASHION ALONG THE VA/NC BORDER AND NE NC
THROUGH TUE. IN THIS SORT OF A NORTHWEST FLOW PATTERN THERE IS THE
POTENTIAL FOR UPSTREAM CONVECTION OVER THE OH VALLEY TO TRACK
SOUTHEASTWARD ACROSS NC... AND FOR NOW WILL LEAVE IN A SLIGHT CHANCE
OF SHOWERS AND STORMS FOR MON/TUE TO ADDRESS THIS POTENTIAL. AS THE
RIDGE ALOFT APPROACHES FROM THE WEST LATE TUE INTO WED... THIS
BOUNDARY SHOULD BE PUSHED A BIT NORTHEASTWARD... WITH A DRYING
COLUMN AND WARMING LOW LEVELS. TEMPS CLOSE TO SEASONAL NORMALS
(WHICH IS LOW-MID 50S FOR LOWS AND MID-UPPER 70S FOR HIGHS) THROUGH
TUE... THEN ABOVE NORMAL TEMPS (HIGHS IN LOW-MID 80S) WED. -GIH
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 200 PM WEDNESDAY...
MOIST AND UNSTABLE AIR MASS COVERS CENTRAL NC WITH SURFACE WINDS
FROM THE SSE OR SOUTH. THIS IS AHEAD OF A COLD FRONT... NOW PUSHING
SLOWLY EASTWARD THROUGH CENTRAL/ERN TN... AND THIS IS EXPECTED TO
CROSS CENTRAL NC LATE THU/THU NIGHT.
NUMEROUS SHOWERS/STORMS WILL CONTINUE TO IMPACT RDU/FAY/RWI THROUGH
THE REST OF THIS AFTERNOON... THROUGH ABOUT 21Z-23Z. INT/GSO SHOULD
STAY MOSTLY DRY BUT WITH PATCHY SHOWERS. BACKGROUND SURFACE WINDS
WILL REMAIN MAINLY FROM THE SOUTH SUSTAINED AT 7-13 KTS... ALTHOUGH
LOCALLY STRONGER WINDS WITH GUSTS OVER 35 KT ARE LIKELY IN AND NEAR
STORMS. MAINLY MVFR CIGS ARE EXPECTED AT ALL SITES THROUGH ABOUT 04Z
TO 06Z... AND MVFR-IFR VSBYS ARE LIKELY IN AND NEAR STORMS FOR THE
NEXT SEVERAL HOURS. AFTER THE 04Z-06Z TIME FRAME... SHOWER/STORM
CHANCES WILL DECREASE... AND LOW CIGS ARE EXPECTED TO FORM WITH IFR
CIGS AND MVFR VSBYS IN FOG ANTICIPATED AREAWIDE LATE TONIGHT. CIGS
EXPECTED TO LIFT TO MVFR AFTER 13Z THU MORNING... AND POSSIBLE TO
VFR AFTER 16Z... WITH WINDS STRENGTHENING FROM THE SSW AT 10-15 KT
GUSTING TO 20-25 KTS.
LOOKING BEYOND 18Z THU: ADDITIONAL SHOWERS AND A FEW STORMS WITH
ENHANCED WIND GUSTS FROM THE SW TO 25-30 KTS ARE POSSIBLE AT RWI/FAY
THU AFTERNOON AHEAD OF THE FRONT. WINDS WILL LIGHTEN AND SHIFT TO BE
FROM THE WSW OR WEST THU NIGHT AFTER FRONTAL PASSAGE THU NIGHT.
OTHERWISE... VFR CONDITIONS EXPECTED TO DOMINATE CENTRAL NC
TERMINALS THROUGH MON. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR NCZ007>011-021>028-
038>043-073>078-083>086-088-089.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...SMITH
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
245 PM EDT WED APR 30 2014
.SYNOPSIS...
A COLD FRONT TO THE WEST WILL MOVE THROUGH THURSDAY NIGHT INTO
EARLY FRIDAY. WEAK HIGH PRESSURE CENTERED TO THE SOUTHWEST WILL EXTEND
INTO THE CAROLINAS FRIDAY THROUGH SUNDAY. A COLD FRONT WILL DROP
SOUTH THROUGH THE AREA SUNDAY NIGHT...THEN BECOME STATIONARY TO
THE SOUTHWEST MONDAY AND TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 PM WED...LATEST SFC ANALYSIS SHOWS WARM FRONT DRAPED
THROUGH SE VA BACK INTO THE NC PIEDMONT. MAIN SFC LOW CURRENTLY NEAR
THE GREAT LAKES AND ATTENDANT COLD FRONT MOVING THROUGH THE OH/TN
VALLEY REGION...WITH ENC REMAINING IN THE WARM SECTOR.
TORNADO WATCH IN EFFECT FOR NORTHERN TIER OF THE COUNTY WARNING
AREA THROUGH 7PM TONIGHT. EASTERN NC REMAINS IN SLIGHT RISK OF
SEVERE WX TODAY. SLIGHTLY BETTER FORCING AND SHEAR AS UPPER TROUGH
AND COLD FRONT APPROACH FROM THE WEST. CONVECTION NOW BECOMING MORE
ORGANIZED ALONG A LINE FROM SE VA DOWN TO THE SC COAST. FORECAST
SOUNDINGS AND SPC MESOANALYSIS SHOW CAPES 1500-2500J/KG...LI VALUES
-4 TO -6C...AND 0-6KM SHEAR AROUND 30KT. MAIN THREATS STILL LOOK
LIKE POTENTIAL FOR DAMAGING WIND GUSTS...HAIL...ISOLATED TORNADOES
AND HEAVY RAIN. HIGH RES MODELS NSSL WRF AND NMM HAVE CURRENT
CONVECTION BECOMING MORE ORGANIZED THIS AFTERNOON WEST OF HIGHWAY
17...WITH NMM AND HRRR THEN SHOWING THE LINE WEAKENING BUT HOLDING
TOGETHER MOVING EASTWARD TOWARD THE COAST THIS EVENING. AT THIS TIME
THE BEST CHANCES FOR SVR WX LOOK TO BE AREAS ALONG AND WEST OF
HIGHWAY 17...MAINLY BTWN 3-10PM. WITH THE POTENTIAL FOR ADDITIONAL
HEAVY RAINFALL...THE ALREADY SATURATED GROUND IN THE COASTAL PLAIN
COULD SEE MORE SIGNIFICANT FLOODING PROBLEMS...MAINLY
MARTIN/PITT/GREENE AND LENOIR COUNTIES WHICH SAW SEVERAL INCHES OF
RAIN YESTERDAY.
MUGGY AGAIN OVERNIGHT WITH LOWS IN THE UPPER 60S/70 DEGREES.
&&
.SHORT TERM /THURSDAY/...
AS OF 240 PM WED...ANOTHER ACTIVE WX DAY EXPECTED ACROSS EASTERN
NC THURSDAY AS THE SVR WX THREAT CONTINUES. THE COLD FRONT AND
UPPER TROUGH WILL CONTINUE TO MOVE EASTWARD INTO THE CAROLINAS
RESULTING IN BETTER FORCING ACROSS THE AREA. ATMOSPHERE VERY
SIMILAR TO WED THOUGH WILL HAVE SLIGHTLY BETTER SHEAR AND
DYNAMICS. FORECAST SOUNDINGS SHOW CAPES 1500-2000J/KG...LI VALUES
-4 TO -6C...AND 0-6KM SHEAR AROUND 40KT. MAIN THREATS STILL LOOK
LIKE POTENTIAL FOR DAMAGING WIND GUSTS...HAIL...ISOLATED TORNADOES
AND HEAVY RAIN. THINK BEST SVR CHANCES WILL BE IN THE EARLY
AFTERNOON TO EVENING HOURS WITH PEAK HEATING. WITH THE POTENTIAL
FOR ADDITIONAL HEAVY RAINFALL WITH PWATS APPROACHING 2
INCHES...THE ALREADY SATURATED GROUND IN THE COASTAL PLAIN COULD
HAVE FURTHER FLOODING ISSUES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
AS OF 230 PM WEDNESDAY...LOOKS LIKE THE SLOW MOVING COLD FRONT WILL
FINALLY MOVE OFF OF THE COAST THURSDAY NIGHT. ONGOING SHOWERS AND
THUNDERSTORMS AHEAD OF THE FRONT ARE EXPECTED EARLY THURSDAY
EVENING. DRIER AIR WILL BEGIN TO FILTER INTO THE AREA FRIDAY WITH
THE FRONT STALLING OFFSHORE AND HIGH PRESSURE TRYING TO BUILD IN
FROM THE NORTH. THE ECMWF IS DRY ON FRIDAY WHILE THE GFS CONTINUES
TO INDICATE ENOUGH RESIDUAL MOISTURE/INSTABILITY FOR A FEW SHOWERS.
CONVERSELY THE GFS IS DRY SATURDAY WHILE THE ECMWF INDICATES THE
POTENTIAL FOR A FEW MAINLY COASTAL SHOWERS. WHATEVER OCCURS NOT
EXPECTING WIDESPREAD OR SIGNIFICANT PRECIPITATION EITHER DAY AND
OVERALL EXPECTING PLEASANT WEATHER OVER THE WEEKEND INTO MONDAY
UNDER THE INFLUENCE OF HIGH PRESSURE.
A DRY COLD FRONT WILL MOVE THROUGH THE AREA MONDAY NIGHT AND STALL
JUST SOUTH OF THE AREA. THE GUIDANCE IS NOW INDICATING THAT FRONT
WILL TEND TO MEANDER NORTH AND SOUTH ACROSS NORTH CAROLINA TUESDAY
AND WEDNESDAY. BOTH THE GFS AND ECMWF INDICATE THE POTENTIAL FOR
LIGHT RAINFALL MONDAY NIGHT INTO TUESDAY AND AGAIN LATER ON
WEDNESDAY WITH THIS FEATURE. WILL CARRY "SILENT" 20% POPS BOTH DAYS
AS NOT EXPECTING WIDESPREAD OR SIGNIFICANT PRECIPITATION AT THIS
TIME.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM /THROUGH 18Z THURSDAY/...
A POTENT SYSTEM WILL CONTINUE TO MOVE EASTWARD ACROSS THE CONUS.
AN ASSOCIATED COLD FRONT WILL APPROACH THE REGION WITH PLENTY OF
SHOWERS AND THUNDERSTORMS AHEAD OF IT. THEREFORE...ANTICIPATE A
VERY UNSETTLED WEATHER PATTERN OVER THE TAF PERIOD. SHOWERS AND
THUNDERSTORMS ARE GOING TO BE A THREAT THROUGH THE
AFTERNOON/EVENING THEN TAPERING OFF EAST TO WEST AS WE GO THROUGH
THE EVENING HOURS. WITH THIS ACTIVITY EXPECT LOWERING CEILINGS AND
VISIBILITY. OVERNIGHT WE ANTICIPATE THUNDERSTORMS TO DIMINISH AND
VICINITY SHOWERS TO PERSIST ACROSS THE REGION. THURSDAY WILL HAVE
MORE WIDELY SCATTERED SHOWERS AND THUNDERSTORMS. CEILINGS SHOULD
BE OVERCAST AROUND 2-3KFT. WINDS WILL BE GUSTY FROM THE SOUTH AS
WELL.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM WEDNESDAY...UNSETTLED CONDITIONS CONTINUE EARLY THURSDAY
EVENING WITH PREFRONTAL SHOWERS AND THUNDERSTORM. DRIER AIR IS
FINALLY EXPECTED TO FILTER INTO THE AREA FRIDAY THROUGH MONDAY AS
HIGH PRESSURE BUILDS INTO EASTERN NC. OTHER THAN EARLY MORNING FOG
PATCHES VFR CONDITIONS ARE EXPECTED TO
PREVAIL.
&&
.MARINE...
SHORT TERM /THROUGH THURSDAY/...
AS OF 240 PM WED...LATEST OBS SHOW S/SE WINDS 10-20KT WITH GUSTS
TO 25KT FOR THE CENTRAL AND NORTHERN WATERS...WITH SEAS 5-9FT.
MODERATE SOUTHERLY FLOW WILL CONTINUE ACROSS THE WATERS TONIGHT
INTO THU. COLD FRONT WILL APPROACH THE WATERS FROM THE WEST
THURSDAY...WITH FLOW BECOMING MORE SW THU AFTERNOON. SCA CONTINUE
FOR WATERS AND PAMLICO SOUND. WILL CONTINUE TO KEEP RIVERS AND
ALBEMARLE SOUND JUST BELOW SCA AT 15-20KT. SEAS WILL PEAK AROUND
6-10FT.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM WEDNESDAY...SW WINDS 15 TO 25 KT WILL OCCUR AHEAD OF
THE FRONT THURSDAY EVENING. THE FRONT WILL SLOWLY PUSH OFFSHORE BY
EARLY FRI WITH WINDS DIMINISHING AND BECOMING W TO NW 10 TO 15 KTS.
SEAS WILL SUBSIDE WITH SCA ENDING ALL WTRS BY FRI MID MORNING. THE
FRONT STALLS OFF THE COAST FRI INTO SAT THEN EDGES EAST SUNDAY AS
HIGH PRESSURE BUILDS OVER THE WATERS. A DRY COLD FRONT IS FORECAST
TO MOVE THROUGH THE WATERS SUNDAY NIGHT AND STALL. STILL EXPECTING
SUB ADVISORY CONDITIONS FRIDAY AFTERNOON INTO SUNDAY WITH MAINLY
WESTERLY OR SOUTHWESTERLY WINDS 15 KT OR LESS AND SEAS 2-3 FT. WINDS
SHIFT TO NORTH 15 TO 20 KT SUNDAY NIGHT INTO MONDAY BEHIND THE FRONT
WITH 3-4 FT SEAS EXPECTED.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT FRIDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR AMZ150-156-158.
&&
$$
SYNOPSIS...HSA/CQD
NEAR TERM...CQD
SHORT TERM...CQD
LONG TERM...JME
AVIATION...LEP/JME
MARINE...CQD/JME
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
240 PM EDT WED APR 30 2014
.SYNOPSIS...
A COLD FRONT TO THE WEST WILL MOVE THROUGH THURSDAY NIGHT INTO
EARLY FRIDAY. WEAK HIGH PRESSURE CENTERED TO THE SOUTHWEST WILL EXTEND
INTO THE CAROLINAS FRIDAY THROUGH SUNDAY. A COLD FRONT WILL DROP
SOUTH THROUGH THE AREA SUNDAY NIGHT...THEN BECOME STATIONARY TO
THE SOUTHWEST MONDAY AND TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 PM WED...LATEST SFC ANALYSIS SHOWS WARM FRONT DRAPED
THROUGH SE VA BACK INTO THE NC PIEDMONT. MAIN SFC LOW CURRENTLY
NEAR THE GREAT LAKES AND ATTENDANT COLD FRONT MOVING THROUGH THE
OH/TN VALLEY REGION...WITH ENC REMAINING IN THE WARM SECTOR.
TORNADO WATCH IN EFFECT FOR NORTHERN TIER OF THE COUNTY WARNING
AREA THROUGH 7PM TONIGHT. EASTERN NC REMAINS IN SLIGHT RISK OF
SEVERE WX TODAY. SLIGHTLY BETTER FORCING AND SHEAR AS UPPER TROUGH
AND COLD FRONT APPROACH FROM THE WEST. SCT ACTIVITY CONTINUES TO
DEVELOP EARLY THIS AFTERNOON. FORECAST SOUNDINGS AND SPC
MESOANALYSIS SHOW CAPES 1500-2500J/KG...LI VALUES -4 TO -6C...AND
0-6KM SHEAR AROUND 30KT. MAIN THREATS STILL LOOK LIKE POTENTIAL
FOR DAMAGING WIND GUSTS...HAIL...ISOLATED TORNADOES AND HEAVY
RAIN. HIGH RES MODELS NSSL WRF AND NMM HAVE CURRENT CONVECTION
BECOMING MORE ORGANIZED THIS AFTERNOON WEST OF HIGHWAY 17...WITH
NMM AND HRRR THEN SHOWING THE LINE WEAKENING BUT HOLDING TOGETHER
MOVING EASTWARD TOWARD THE COAST THIS EVENING. AT THIS TIME THE
BEST CHANCES FOR SVR WX LOOK TO BE AREAS ALONG AND WEST OF HIGHWAY
17...MAINLY BTWN 3-10PM. WITH THE POTENTIAL FOR ADDITIONAL HEAVY
RAINFALL...THE ALREADY SATURATED GROUND IN THE COASTAL PLAIN COULD
SEE MORE SIGNIFICANT FLOODING PROBLEMS...MAINLY MARTIN/PITT/GREENE
AND LENOIR COUNTIES WHICH SAW SEVERAL INCHES OF RAIN YESTERDAY.
MUGGY AGAIN OVERNIGHT WITH LOWS IN THE UPPER 60S/70 DEGREES.
&&
.SHORT TERM /THURSDAY/...
AS OF 240 PM WED...ANOTHER ACTIVE WX DAY EXPECTED ACROSS EASTERN
NC THURSDAY AS THE SVR WX THREAT CONTINUES. THE COLD FRONT AND
UPPER TROUGH WILL CONTINUE TO MOVE EASTWARD INTO THE CAROLINAS
RESULTING IN BETTER FORCING ACROSS THE AREA. ATMOSPHERE VERY
SIMILAR TO WED THOUGH WILL HAVE SLIGHTLY BETTER SHEAR AND
DYNAMICS. FORECAST SOUNDINGS SHOW CAPES 1500-2000J/KG...LI VALUES
-4 TO -6C...AND 0-6KM SHEAR AROUND 40KT. MAIN THREATS STILL LOOK
LIKE POTENTIAL FOR DAMAGING WIND GUSTS...HAIL...ISOLATED TORNADOES
AND HEAVY RAIN. THINK BEST SVR CHANCES WILL BE IN THE EARLY
AFTERNOON TO EVENING HOURS WITH PEAK HEATING. WITH THE POTENTIAL
FOR ADDITIONAL HEAVY RAINFALL WITH PWATS APPROACHING 2
INCHES...THE ALREADY SATURATED GROUND IN THE COASTAL PLAIN COULD
HAVE FURTHER FLOODING ISSUES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
AS OF 230 PM WEDNESDAY...LOOKS LIKE THE SLOW MOVING COLD FRONT WILL
FINALLY MOVE OFF OF THE COAST THURSDAY NIGHT. ONGOING SHOWERS AND
THUNDERSTORMS AHEAD OF THE FRONT ARE EXPECTED EARLY THURSDAY
EVENING. DRIER AIR WILL BEGIN TO FILTER INTO THE AREA FRIDAY WITH
THE FRONT STALLING OFFSHORE AND HIGH PRESSURE TRYING TO BUILD IN
FROM THE NORTH. THE ECMWF IS DRY ON FRIDAY WHILE THE GFS CONTINUES
TO INDICATE ENOUGH RESIDUAL MOISTURE/INSTABILITY FOR A FEW SHOWERS.
CONVERSELY THE GFS IS DRY SATURDAY WHILE THE ECMWF INDICATES THE
POTENTIAL FOR A FEW MAINLY COASTAL SHOWERS. WHATEVER OCCURS NOT
EXPECTING WIDESPREAD OR SIGNIFICANT PRECIPITATION EITHER DAY AND
OVERALL EXPECTING PLEASANT WEATHER OVER THE WEEKEND INTO MONDAY
UNDER THE INFLUENCE OF HIGH PRESSURE.
A DRY COLD FRONT WILL MOVE THROUGH THE AREA MONDAY NIGHT AND STALL
JUST SOUTH OF THE AREA. THE GUIDANCE IS NOW INDICATING THAT FRONT
WILL TEND TO MEANDER NORTH AND SOUTH ACROSS NORTH CAROLINA TUESDAY
AND WEDNESDAY. BOTH THE GFS AND ECMWF INDICATE THE POTENTIAL FOR
LIGHT RAINFALL MONDAY NIGHT INTO TUESDAY AND AGAIN LATER ON
WEDNESDAY WITH THIS FEATURE. WILL CARRY "SILENT" 20% POPS BOTH DAYS
AS NOT EXPECTING WIDESPREAD OR SIGNIFICANT PRECIPITATION AT THIS
TIME.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM /THROUGH 18Z THURSDAY/...
A POTENT SYSTEM WILL CONTINUE TO MOVE EASTWARD ACROSS THE CONUS.
AN ASSOCIATED COLD FRONT WILL APPROACH THE REGION WITH PLENTY OF
SHOWERS AND THUNDERSTORMS AHEAD OF IT. THEREFORE...ANTICIPATE A
VERY UNSETTLED WEATHER PATTERN OVER THE TAF PERIOD. SHOWERS AND
THUNDERSTORMS ARE GOING TO BE A THREAT THROUGH THE
AFTERNOON/EVENING THEN TAPERING OFF EAST TO WEST AS WE GO THROUGH
THE EVENING HOURS. WITH THIS ACTIVITY EXPECT LOWERING CEILINGS AND
VISIBILITY. OVERNIGHT WE ANTICIPATE THUNDERSTORMS TO DIMINISH AND
VICINITY SHOWERS TO PERSIST ACROSS THE REGION. THURSDAY WILL HAVE
MORE WIDELY SCATTERED SHOWERS AND THUNDERSTORMS. CEILINGS SHOULD
BE OVERCAST AROUND 2-3KFT. WINDS WILL BE GUSTY FROM THE SOUTH AS
WELL.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM WEDNESDAY...UNSETTLED CONDITIONS CONTINUE EARLY THURSDAY
EVENING WITH PREFRONTAL SHOWERS AND THUNDERSTORM. DRIER AIR IS
FINALLY EXPECTED TO FILTER INTO THE AREA FRIDAY THROUGH MONDAY AS
HIGH PRESSURE BUILDS INTO EASTERN NC. OTHER THAN EARLY MORNING FOG
PATCHES VFR CONDITIONS ARE EXPECTED TO
PREVAIL.
&&
.MARINE...
SHORT TERM /THROUGH THURSDAY/...
AS OF 240 PM WED...LATEST OBS SHOW S/SE WINDS 10-20KT WITH GUSTS
TO 25KT FOR THE CENTRAL AND NORTHERN WATERS...WITH SEAS 5-9FT.
MODERATE SOUTHERLY FLOW WILL CONTINUE ACROSS THE WATERS TONIGHT
INTO THU. COLD FRONT WILL APPROACH THE WATERS FROM THE WEST
THURSDAY...WITH FLOW BECOMING MORE SW THU AFTERNOON. SCA CONTINUE
FOR WATERS AND PAMLICO SOUND. WILL CONTINUE TO KEEP RIVERS AND
ALBEMARLE SOUND JUST BELOW SCA AT 15-20KT. SEAS WILL PEAK AROUND
6-10FT.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM WEDNESDAY...SW WINDS 15 TO 25 KT WILL OCCUR AHEAD OF
THE FRONT THURSDAY EVENING. THE FRONT WILL SLOWLY PUSH OFFSHORE BY
EARLY FRI WITH WINDS DIMINISHING AND BECOMING W TO NW 10 TO 15 KTS.
SEAS WILL SUBSIDE WITH SCA ENDING ALL WTRS BY FRI MID MORNING. THE
FRONT STALLS OFF THE COAST FRI INTO SAT THEN EDGES EAST SUNDAY AS
HIGH PRESSURE BUILDS OVER THE WATERS. A DRY COLD FRONT IS FORECAST
TO MOVE THROUGH THE WATERS SUNDAY NIGHT AND STALL. STILL EXPECTING
SUB ADVISORY CONDITIONS FRIDAY AFTERNOON INTO SUNDAY WITH MAINLY
WESTERLY OR SOUTHWESTERLY WINDS 15 KT OR LESS AND SEAS 2-3 FT. WINDS
SHIFT TO NORTH 15 TO 20 KT SUNDAY NIGHT INTO MONDAY BEHIND THE FRONT
WITH 3-4 FT SEAS EXPECTED.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT FRIDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR AMZ150-156-158.
&&
$$
SYNOPSIS...HSA/CQD
NEAR TERM...CQD
SHORT TERM...CQD
LONG TERM...JME
AVIATION...LEP/JME
MARINE...CQD/JME
AREA FORECAST DISCUSSION
NWS RALEIGH NC
205 PM EDT WED APR 30 2014
.SYNOPSIS... A LARGE AND VIGOROUS STORM SYSTEM OVER THE MIDWEST WILL
CONTINUE TO BRING UNSETTLED WEATHER TO OUR REGION INTO TONIGHT. A
COLD FRONT WILL MOVE SLOWLY EASTWARD ACROSS THE REGION LATE THURSDAY
INTO THURSDAY NIGHT. DRY AND COOLER WEATHER WILL SPREAD IN FROM THE
WEST FRIDAY AND SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1235 PM WEDNESDAY...
UPDATE... A LARGE MULTICELL COMPLEX HAS FORMED FROM CHARLESTON NORTH
INTO EAST-CENTRAL NC ALONG NUMEROUS MERGING BOUNDARIES. WHILE NOT
COINCIDENT WITH THE BEST DEEP LAYER SHEAR...LOW-LEVEL HELICITY
VALUES MAY STILL SUPPORT SOME EMBEDDED ROTATING STORMS. THE
ORIENTATION OF THE STORM CLUSTERS SUGGEST FLASH FLOODING MAY BE A
BIGGER CONCERN ALONG THE I-95 CORRIDOR...WHERE SEVERAL INCHES OF
RAIN FELL JUST YESTERDAY. WILL BE MAKING SOME EDITS TO THE FORECAST
TO REFLECT THE EASTWARD SHIFT IN FOCUS. -SMITH
THE WEDGE/WARM FRONT CONTINUES TO PUSH NORTHWEST AND IS JUST EAST
IF THE TRIAD...PUTTING NEARLY ALL OF CENTRAL NC IN THE WARM SECTOR
CHARACTERIZED BY LOWER 70 DEWPOINTS. REGIONALLY...THERE IS
WIDESPREAD CLOUD COVER FROM CONVECTION ALONG THE GULF COAST...BUT
SPC MESOANALYSIS SHOWS DESTABILIZATION ALREADY UNDERWAY IN THE WARM
SECTOR...AIDED BY RELATIVELY STEEP MID LEVEL LAPSE RATES BETWEEN
850MB AND 500MB PER THE KGSO 12Z RAOB. LATEST RAP SOUNDINGS SHOW
1000-2000 J/KG MLCAPE IN THE WARM SECTOR BY EARLY AFTERNOON. BULK
SHEAR CONTINUES TO BE STRONG WITH A CORRIDOR OF 45-50KT OVER THE
WESTERN HALF OF THE STATE. LOW-LEVEL HODOGRAPHS REMAIN CYCLONICALLY
CURVED WITH SOUTHEASTERLY SURFACE WINDS AND A 40KT 850MB FLOW OVER
THE CAROLINAS. OUTSIDE OF THE RETREATING WEDGE FRONT...TRIGGERS FOR
CONVECTION ARE A LITTLE MORE NEBULOUS...BUT CONVECTION IS ALREADY
ONGOING OVER CENTRAL SC...WITH A REMNANT MCV OVER THE SAVANNAH RIVER
BASIN. RAP VORT FORECASTS BRING THIS MCV OVER THE SANDHILLS IN THE
17-19Z TIME FRAME. THIS MAY THE MOST OBVIOUS FEATURE UPSTREAM TO
KEY ON...THOUGH CONVECTION SHOULD CONTINUE TO DEVELOP ALONG
DIFFERENTIAL HEATING AND OUTFLOW BOUNDARIES. ALL OF THESE
INGREDIENTS WILL SUPPORT SEVERE STORMS WITH THE POTENTIAL FOR LARGE
HAIL...DAMAGING WINDS AND ISOLATED TORNADOES.
GIVEN THAT THE TRIAD IS CLOSE TO BEING SCOURED OUT FO THE STABLE
AIRMASS...WILL FORECAST HIGHS IN THE 75-83 RANGE.
WHILE RAINFALL HAS BEEN A LITTLE LACK LUSTER OVER THE PIEDMONT...
STORM MOTION TODAY SHOULD STILL SUPPORT TRAINING OF CELLS....AND
AREAS ALONG THE I-95 CORRIDOR WERE MORE THAN PRIMED WITH LAST
EVENINGS RAINFALL. THUS...THE FLASH FLOOD WATCH WILL CONTINUE TODAY.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 330AM WEDNESDAY...
THURSDAY...THREAT FOR SCATTERED SHOWERS AND A FEW T-STORMS WILL
REMAIN BASICALLY EAST OF HIGHWAY 1 THROUGH MID DAY....AND EAST OF I-
95 THROUGH LATE AFTERNOON AS MID LEVEL TROUGH CROSSES THE REGION.
WIND PROFILES AND AVAILABLE INSTABILITY SUGGEST THAT STORMS SHOULD
REMAIN BELOW SEVERE CRITERIA. SLIGHTLY COOLER TEMPS THU WITH MAX
TEMPS RANGING BETWEEN THE MID 70S NE TO AROUND 80 SE.
A MORE STABLE...DRIER...COOLER AIR MASS WILL SETTLE OVER THE
FORECAST AREA THURSDAY NIGHT INTO FRIDAY. A WEAK UPPER DISTURBANCE
PASSING OVERHEAD FRIDAY AFTERNOON MAY TRIGGER AN ISOLATED SHOWER OR
TWO OVER OUR SE COUNTIES...IF ENOUGH MOISTURE IS AVAILABLE. MAX
TEMPS FRIDAY NEAR 70-LOWER 70S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 1225 PM TUESDAY...
WE SHOULD SEE LINGERING MID-HIGH CLOUDS ESPECIALLY IN THE ERN CWA
THROUGH MUCH OF SAT... AS A POTENT VORTICITY MAX CROSSES GA AND THE
CAROLINAS... BUT DRY/STABLE LOW LEVELS WILL INHIBIT PRECIP
DEVELOPMENT. OTHERWISE... ONCE THE MID LEVEL TROUGH AXIS FINALLY
SHIFTS TO OUR EAST SAT EVENING... EXPECT DRY AND SEASONABLE WEATHER
FOR SUNDAY. A STRONG MID LEVEL CLOSED LOW WILL TRACK ESE ACROSS THE
ST LAWRENCE VALLEY AND NEW ENGLAND SUNDAY... SETTLING JUST OFF THE
NEW ENGLAND COAST MON BEFORE WOBBLING TO THE EAST OR NE LATE TUE
THROUGH WED. TO OUR WEST... BROAD RIDGING OVER THE SW QUARTER OF THE
CONUS ON SUNDAY WILL SHIFT EASTWARD THROUGH THE CENTRAL STATES...
AMPLIFYING AS IT REACHES THE SOUTHEAST STATES BY WED. THIS WILL
RESULT IN GENERALLY FLAT NORTHWESTERLY MID LEVEL FLOW OVER THE
REGION. A BACKDOOR FRONTAL ZONE ORIENTED WEST-EAST ACROSS VA SUNDAY
IS EXPECTED TO DIP SOUTHWARD ACROSS NE NC MONDAY... THEN HOLD MAINLY
STATIONARY IN A NW-SE FASHION ALONG THE VA/NC BORDER AND NE NC
THROUGH TUE. IN THIS SORT OF A NORTHWEST FLOW PATTERN THERE IS THE
POTENTIAL FOR UPSTREAM CONVECTION OVER THE OH VALLEY TO TRACK
SOUTHEASTWARD ACROSS NC... AND FOR NOW WILL LEAVE IN A SLIGHT CHANCE
OF SHOWERS AND STORMS FOR MON/TUE TO ADDRESS THIS POTENTIAL. AS THE
RIDGE ALOFT APPROACHES FROM THE WEST LATE TUE INTO WED... THIS
BOUNDARY SHOULD BE PUSHED A BIT NORTHEASTWARD... WITH A DRYING
COLUMN AND WARMING LOW LEVELS. TEMPS CLOSE TO SEASONAL NORMALS
(WHICH IS LOW-MID 50S FOR LOWS AND MID-UPPER 70S FOR HIGHS) THROUGH
TUE... THEN ABOVE NORMAL TEMPS (HIGHS IN LOW-MID 80S) WED. -GIH
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 200 PM WEDNESDAY...
MOIST AND UNSTABLE AIR MASS COVERS CENTRAL NC WITH SURFACE WINDS
FROM THE SSE OR SOUTH. THIS IS AHEAD OF A COLD FRONT... NOW PUSHING
SLOWLY EASTWARD THROUGH CENTRAL/ERN TN... AND THIS IS EXPECTED TO
CROSS CENTRAL NC LATE THU/THU NIGHT.
NUMEROUS SHOWERS/STORMS WILL CONTINUE TO IMPACT RDU/FAY/RWI THROUGH
THE REST OF THIS AFTERNOON... THROUGH ABOUT 21Z-23Z. INT/GSO SHOULD
STAY MOSTLY DRY BUT WITH PATCHY SHOWERS. BACKGROUND SURFACE WINDS
WILL REMAIN MAINLY FROM THE SOUTH SUSTAINED AT 7-13 KTS... ALTHOUGH
LOCALLY STRONGER WINDS WITH GUSTS OVER 35 KT ARE LIKELY IN AND NEAR
STORMS. MAINLY MVFR CIGS ARE EXPECTED AT ALL SITES THROUGH ABOUT 04Z
TO 06Z... AND MVFR-IFR VSBYS ARE LIKELY IN AND NEAR STORMS FOR THE
NEXT SEVERAL HOURS. AFTER THE 04Z-06Z TIME FRAME... SHOWER/STORM
CHANCES WILL DECREASE... AND LOW CIGS ARE EXPECTED TO FORM WITH IFR
CIGS AND MVFR VSBYS IN FOG ANTICIPATED AREAWIDE LATE TONIGHT. CIGS
EXPECTED TO LIFT TO MVFR AFTER 13Z THU MORNING... AND POSSIBLE TO
VFR AFTER 16Z... WITH WINDS STRENGTHENING FROM THE SSW AT 10-15 KT
GUSTING TO 20-25 KTS.
LOOKING BEYOND 18Z THU: ADDITIONAL SHOWERS AND A FEW STORMS WITH
ENHANCED WIND GUSTS FROM THE SW TO 25-30 KTS ARE POSSIBLE AT RWI/FAY
THU AFTERNOON AHEAD OF THE FRONT. WINDS WILL LIGHTEN AND SHIFT TO BE
FROM THE WSW OR WEST THU NIGHT AFTER FRONTAL PASSAGE THU NIGHT.
OTHERWISE... VFR CONDITIONS EXPECTED TO DOMINATE CENTRAL NC
TERMINALS THROUGH MON. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR NCZ007>011-021>028-
038>043-073>078-083>086-088-089.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...SMITH
SHORT TERM...WSS
LONG TERM...HARTFIELD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
145 PM EDT WED APR 30 2014
.SYNOPSIS...
A COLD FRONT TO THE WEST WILL MOVE THROUGH THURSDAY NIGHT. WEAK
HIGH PRESSURE CENTERED TO THE SOUTHWEST WILL EXTEND INTO THE
CAROLINAS FRIDAY THROUGH SUNDAY. A COLD FRONT WILL DROP SOUTH
THROUGH THE AREA SUNDAY. IT WILL BECOME STATIONARY TO THE
SOUTHWEST MONDAY AND TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1240 PM WED...LATEST SFC ANALYSIS SHOWS FRONTAL BOUNDARY NOW
NORTH OF THE AREA...DRAPED THROUGH SE VA BACK INTO THE NC
PIEDMONT. MAIN SFC LOW CURRENTLY NEAR THE GREAT LAKES AND
ATTENDANT COLD FRONT MOVING THROUGH THE OH/TN VALLEY REGION...WITH
ENC REMAINING IN THE WARM SECTOR.
EASTERN NC REMAINS IN SLIGHT RISK OF SEVERE WX TODAY. SLIGHTLY BETTER
FORCING AND SHEAR AS UPPER TROUGH AND COLD FRONT APPROACH FROM
THE WEST. ONLY LIMITING FACTOR COULD BE CLOUD COVER THIS MORNING
AND LACK OF INSOLATION. SCT ACTIVITY CONTINUES TO DEVELOP EARLY THIS
AFTERNOON. FORECAST SOUNDINGS AND SPC MESOANALYSIS SHOW CAPES
1500-2500J/KG...LI VALUES -4 TO -6C...AND 0-6KM SHEAR AROUND 30KT.
MAIN THREATS STILL LOOK LIKE POTENTIAL FOR DAMAGING WIND
GUSTS...HAIL...ISOLATED TORNADOES AND HEAVY RAIN. HIGH RES MODELS
NSSL WRF AND NMM HAVE CONVECTION CURRENT ACTIVITY BECOMING MORE
ORGANIZED THIS AFTERNOON...WITH NMM AND HRRR SHOWING THE LINE WEAKENING
BUT HOLDING TOGETHER MOVING EASTWARD TOWARD THE COAST THIS
EVENING. AT THIS TIME THE BEST CHANCES FOR SVR WX LOOK TO BE AREAS
ALONG AND WEST OF HIGHWAY 17...MAINLY BTWN 2-10PM. WITH THE
POTENTIAL FOR ADDITIONAL HEAVY RAINFALL...THE ALREADY SATURATED
GROUND IN THE COASTAL PLAIN COULD SEE MORE SIGNIFICANT FLOODING
PROBLEMS...MAINLY MARTIN/PITT/GREENE AND LENOIR COUNTIES WHICH SAW
SEVERAL INCHES OF RAIN YESTERDAY.
HIGHS TODAY IN THE MID 70S TO MID 80S WITH DEWPOINTS IN THE 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
AS OF 345 AM WED...THE COLD FRONT WILL BE MOVING THROUGH THE MID-
STATE AREA TONIGHT. MODELS SHOW AXIS OF INSTABILITY SHIFTING EAST
INTO EASTERN NORTH CAROLINA. MAINTAINED LIKELY WEST TO CHANCE EAST
THIS EVENING...BECOMING LIKELY ALL AREAS AFTER MIDNIGHT. WARM AND
MUGGY CONDITIONS FORECAST WITH LOWS THROUGHOUT IN THE UPPER 60S.
&&
.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
AS OF 345 AM WED...A SWATH OF DEEP MOISTURE ACCOMPANYING A SLOW
MOVING MID LEVEL TROF WILL OVERSPREAD THE REGION DURING THE DAY
THURSDAY THEN MOVE THRU THE FORECAST AREA THURSDAY NIGHT. STILL
SOME MODEL TIMING DIFFERENCES ON THE BEST COVERAGE OF PRECIP WILL
OCCUR SO WILL CONTINUE TO HOLD POPS MAINLY IN THE LIKELY RANGE FOR
NOW THRU AROUND MIDNIGHT THURSDAY. THE BEST CHANCES FOR SEVERE
STORMS/POSSIBLE TORNADOES WILL BE DURING PEAK DIURNAL HEATING
DURING THE AFTERNOON AND LINGERING INTO THE EARLY EVENING HOURS.
CLOUD COVER MAY LIMIT POTENTIAL INSTABILITY BUT VEERING VERTICAL
WIND PROFILES AS A 50 KT LLJ CROSSES THE AREA WILL SUSTAIN
UPDRAFTS/ROTATING THUNDERSTORMS INTO THE EVENING HOURS. WITH MID-
UPPER 60S DEW POINTS AND PRECIP WATER CONTINUING +2SD ABV NORMAL,
HEAVY DOWNPOURS WILL ACCOMPANY STRONG CONVECTION WITH 1-2 INCHES
OF RAIN LIKELY WITH LOCALLY HIGHER AMOUNTS POSSIBLE.
MID LEVEL DRY SLOT AND SFC FRONTAL PASSAGE SIGNALS AN END TO THE
STEADIER PRECIP FOR MOST AREAS LATE THU EVENING BUT A BIT OF
LINGERING LIGHT RAIN THRU EARLY FRIDAY MORNING ALONG THE COAST.
THE FRONT STALLS OUT UNDER PARALLELING WSW STEERING FLOW OFF THE
COAST FRIDAY. MODELS HAVE BEEN CONSISTENT IN SHOWING A WEAK WAVE OF
LOW PRESSURE DEVELOPING ON THE FRONT AND TEMPORARILY PUSH AN AREA OF
DEEPER MOISTURE AND WEAK FORCING ONTO THE SE NC COAST LATE FRIDAY
AND FRIDAY NIGHT. WILL CONTINUE WITH SLIGHT CHANCES FOR RAIN
CONFINED TO SE AREAS ONLY THRU FRIDAY NIGHT. GOOD MODEL CONSENSUS IS
DEVELOPING TO PUSH THE STALLED BNDRY OUT TO SEA EARLY SATURDAY
LEADING TO A DRY AND PLEASANT WEEKEND. TEMPS WILL BE A BIT BLO
NORMAL FOR SATURDAY AND SATURDAY NIGHT THEN NEAR SEASONAL AVERAGES
ON SUNDAY WITH HIGHS NEARING 80F INLAND.
A NORTHERN STREAM SHORT WAVE WILL DRIVE A WEAK BACKDOOR COLD FRONT
THRU THE AREA LATE SUNDAY NIGHT OR EARLY MONDAY. LITTLE AVAILABLE
MOISTURE TO PRODUCE WIDESPREAD PRECIP SO WILL KEEP FORECAST DRY FOR
NOW. THIS FRONT EVENTUALLY STALLS SW OF THE AREA ON TUESDAY WITH
HIGH PRESSURE BUILDING IN FROM THE NORTH.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM /THROUGH 18Z THURSDAY/...
A POTENT SYSTEM WILL CONTINUE TO MOVE EASTWARD ACROSS THE CONUS.
AN ASSOCIATED COLD FRONT WILL APPROACH THE REGION WITH PLENTY OF
SHOWERS AND THUNDERSTORMS AHEAD OF IT. THEREFORE...ANTICIPATE A
VERY UNSETTLED WEATHER PATTERN OVER THE TAF PERIOD. SHOWERS AND
THUNDERSTORMS ARE GOING TO BE A THREAT THROUGH THE
AFTERNOON/EVENING THEN TAPERING OFF EAST TO WEST AS WE GO THROUGH
THE EVENING HOURS. WITH THIS ACTIVITY EXPECT LOWERING CEILINGS AND
VISIBILITY. OVERNIGHT WE ANTICIPATE THUNDERSTORMS TO DIMINISH AND
VICINITY SHOWERS TO PERSIST ACROSS THE REGION. THURSDAY WILL HAVE
MORE WIDELY SCATTERED SHOWERS AND THUNDERSTORMS. CEILINGS SHOULD
BE OVERCAST AROUND 2-3KFT. WINDS WILL BE GUSTY FROM THE SOUTH AS
WELL.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 345 AM WED...UNSETTLED CONDITIONS CONTINUE INTO THURSDAY
EVENING WITH SCT TO NUMEROUS SHOWERS/STORMS AND SUB VFR
CONDITIONS. DRIER AIR IS FINALLY EXPECTED TO FILTER INTO THE AREA
THURSDAY NIGHT AND FRIDAY AND ESPECIALLY SATURDAY AND SUNDAY AS
HIGH PRESSURE BUILDS INTO EASTERN NC. OTHER THAN EARLY MORNING FOG
PATCHES VFR CONDITIONS ARE EXPECTED TO PREVAIL LATE IN THE WEEK
AND FOR MUCH OF THE UPCOMING WEEKEND.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1240 PM WED...NO SIG CHANGES NEEDED TO ONGOING FORECAST THIS
AFTERNOON. LATEST OBS SHOW SE/S WINDS 10-20KT WITH SEAS
4-8FT...HIGHEST NORTH OF OCRACOKE. SMALL CRAFT ADVISORIES CONTINUE
FOR ALL COASTAL WATERS AND THE PAMLICO SOUND...WITH THE ALBEMARLE
SOUND AND RIVERS CAPPED AT 15-20 KNOTS.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 345 AM WED...SW WINDS 15 TO 25 KT WILL OCCUR AHEAD OF THE
FRONT INTO THURSDAY EVENING. THE FRONT WILL SLOWLY PUSH OFFSHORE
BY EARLY FRI WITH WINDS DIMINISHING AND BECOMING W TO NW 10 TO 15
KTS. SEAS SHLD SUBSIDE WITH SCA ENDING ALL WTRS BY FRI MORNING.
THE FRONT STALLS OFF THE COAST FRI INTO SAT THEN EDGES EAST SUNDAY
AS HIGH PRESSURE BUILDS OVER THE WATERS. EXPECT SUB ADVISORY
CONDITIONS FRIDAY AFTERNOON INTO SUNDAY WITH WESTERLY WINDS 15 KT
OR LESS AND SEAS 2-4 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT FRIDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR AMZ150-156-158.
&&
$$
SYNOPSIS...HSA
NEAR TERM...HSA/CQD
SHORT TERM...HSA
LONG TERM...BTC
AVIATION...LEP
MARINE...BTC/HSA/CQD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1240 PM EDT WED APR 30 2014
.SYNOPSIS...
A COLD FRONT TO THE WEST WILL MOVE THROUGH THURSDAY NIGHT. WEAK
HIGH PRESSURE CENTERED TO THE SOUTHWEST WILL EXTEND INTO THE
CAROLINAS FRIDAY THROUGH SUNDAY. A COLD FRONT WILL DROP SOUTH
THROUGH THE AREA SUNDAY. IT WILL BECOME STATIONARY TO THE
SOUTHWEST MONDAY AND TUESDAY.
&&
.NEAR TERM /TODAY/...
AS OF 1240 PM WED...LATEST SFC ANALYSIS SHOWS FRONTAL BOUNDARY NOW
NORTH OF THE AREA...DRAPED THROUGH SE VA BACK INTO THE NC
PIEDMONT. MAIN SFC LOW CURRENTLY NEAR THE GREAT LAKES AND
ATTENDANT COLD FRONT MOVING THROUGH THE OH/TN VALLEY REGION...WITH
ENC REMAINING IN THE WARM SECTOR.
EASTERN NC REMAINS IN SLIGHT RISK OF SEVERE WX TODAY. SLIGHTLY BETTER
FORCING AND SHEAR AS UPPER TROUGH AND COLD FRONT APPROACH FROM
THE WEST. ONLY LIMITING FACTOR COULD BE CLOUD COVER THIS MORNING
AND LACK OF INSOLATION. SCT ACTIVITY CONTINUES TO DEVELOP EARLY THIS
AFTERNOON. FORECAST SOUNDINGS AND SPC MESOANALYSIS SHOW CAPES
1500-2500J/KG...LI VALUES -4 TO -6C...AND 0-6KM SHEAR AROUND 30KT.
MAIN THREATS STILL LOOK LIKE POTENTIAL FOR DAMAGING WIND
GUSTS...HAIL...ISOLATED TORNADOES AND HEAVY RAIN. HIGH RES MODELS
NSSL WRF AND NMM HAVE CONVECTION CURRENT ACTIVITY BECOMING MORE
ORGANIZED THIS AFTERNOON...WITH NMM AND HRRR SHOWING THE LINE WEAKENING
BUT HOLDING TOGETHER MOVING EASTWARD TOWARD THE COAST THIS
EVENING. AT THIS TIME THE BEST CHANCES FOR SVR WX LOOK TO BE AREAS
ALONG AND WEST OF HIGHWAY 17...MAINLY BTWN 2-10PM. WITH THE
POTENTIAL FOR ADDITIONAL HEAVY RAINFALL...THE ALREADY SATURATED
GROUND IN THE COASTAL PLAIN COULD SEE MORE SIGNIFICANT FLOODING
PROBLEMS...MAINLY MARTIN/PITT/GREENE AND LENOIR COUNTIES WHICH SAW
SEVERAL INCHES OF RAIN YESTERDAY.
HIGHS TODAY IN THE MID 70S TO MID 80S WITH DEWPOINTS IN THE 60S.
&&
.SHORT TERM /TONIGHT/...
AS OF 345 AM WED...THE COLD FRONT WILL BE MOVING THROUGH THE MID-
STATE AREA TONIGHT. MODELS SHOW AXIS OF INSTABILITY SHIFTING EAST
INTO EASTERN NORTH CAROLINA. MAINTAINED LIKELY WEST TO CHANCE EAST
THIS EVENING...BECOMING LIKELY ALL AREAS AFTER MIDNIGHT. WARM AND
MUGGY CONDITIONS FORECAST WITH LOWS THROUGHOUT IN THE UPPER 60S.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 345 AM WED...A SWATH OF DEEP MOISTURE ACCOMPANYING A SLOW
MOVING MID LEVEL TROF WILL OVERSPREAD THE REGION DURING THE DAY
THURSDAY THEN MOVE THRU THE FORECAST AREA THURSDAY NIGHT. STILL
SOME MODEL TIMING DIFFERENCES ON THE BEST COVERAGE OF PRECIP WILL
OCCUR SO WILL CONTINUE TO HOLD POPS MAINLY IN THE LIKELY RANGE FOR
NOW THRU AROUND MIDNIGHT THURSDAY. THE BEST CHANCES FOR SEVERE
STORMS/POSSIBLE TORNADOES WILL BE DURING PEAK DIURNAL HEATING
DURING THE AFTERNOON AND LINGERING INTO THE EARLY EVENING HOURS.
CLOUD COVER MAY LIMIT POTENTIAL INSTABILITY BUT VEERING VERTICAL
WIND PROFILES AS A 50 KT LLJ CROSSES THE AREA WILL SUSTAIN
UPDRAFTS/ROTATING THUNDERSTORMS INTO THE EVENING HOURS. WITH MID-
UPPER 60S DEW POINTS AND PRECIP WATER CONTINUING +2SD ABV NORMAL,
HEAVY DOWNPOURS WILL ACCOMPANY STRONG CONVECTION WITH 1-2 INCHES
OF RAIN LIKELY WITH LOCALLY HIGHER AMOUNTS POSSIBLE.
MID LEVEL DRY SLOT AND SFC FRONTAL PASSAGE SIGNALS AN END TO THE
STEADIER PRECIP FOR MOST AREAS LATE THU EVENING BUT A BIT OF
LINGERING LIGHT RAIN THRU EARLY FRIDAY MORNING ALONG THE COAST.
THE FRONT STALLS OUT UNDER PARALLELING WSW STEERING FLOW OFF THE
COAST FRIDAY. MODELS HAVE BEEN CONSISTENT IN SHOWING A WEAK WAVE OF
LOW PRESSURE DEVELOPING ON THE FRONT AND TEMPORARILY PUSH AN AREA OF
DEEPER MOISTURE AND WEAK FORCING ONTO THE SE NC COAST LATE FRIDAY
AND FRIDAY NIGHT. WILL CONTINUE WITH SLIGHT CHANCES FOR RAIN
CONFINED TO SE AREAS ONLY THRU FRIDAY NIGHT. GOOD MODEL CONSENSUS IS
DEVELOPING TO PUSH THE STALLED BNDRY OUT TO SEA EARLY SATURDAY
LEADING TO A DRY AND PLEASANT WEEKEND. TEMPS WILL BE A BIT BLO
NORMAL FOR SATURDAY AND SATURDAY NIGHT THEN NEAR SEASONAL AVERAGES
ON SUNDAY WITH HIGHS NEARING 80F INLAND.
A NORTHERN STREAM SHORT WAVE WILL DRIVE A WEAK BACKDOOR COLD FRONT
THRU THE AREA LATE SUNDAY NIGHT OR EARLY MONDAY. LITTLE AVAILABLE
MOISTURE TO PRODUCE WIDESPREAD PRECIP SO WILL KEEP FORECAST DRY FOR
NOW. THIS FRONT EVENTUALLY STALLS SW OF THE AREA ON TUESDAY WITH
HIGH PRESSURE BUILDING IN FROM THE NORTH.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 7 AM WED...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
FORECAST AT ALL 4 AREA TERMINALS ESPECIALLY THIS AFTERNOON INTO
THE OVERNIGHT. ANY STORM HAS THE POTENTIAL TO PRODUCE DAMAGING
DOWNBURST WINDS...HAIL AND POSSIBLY A TORNADO. SURFACE WINDS WILL
BE FROM THE SOUTH AT 15-20 KNOTS TODAY INTO TONIGHT. CONDITIONS
GENERALLY VFR OUTSIDE OF CONVECTION.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 345 AM WED...UNSETTLED CONDITIONS CONTINUE INTO THURSDAY
EVENING WITH SCT TO NUMEROUS SHOWERS/STORMS AND SUB VFR
CONDITIONS. DRIER AIR IS FINALLY EXPECTED TO FILTER INTO THE AREA
THURSDAY NIGHT AND FRIDAY AND ESPECIALLY SATURDAY AND SUNDAY AS
HIGH PRESSURE BUILDS INTO EASTERN NC. OTHER THAN EARLY MORNING FOG
PATCHES VFR CONDITIONS ARE EXPECTED TO PREVAIL LATE IN THE WEEK
AND FOR MUCH OF THE UPCOMING WEEKEND.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1240 PM WED...NO SIG CHANGES NEEDED TO ONGOING FORECAST THIS
AFTERNOON. LATEST OBS SHOW SE/S WINDS 10-20KT WITH SEAS
4-8FT...HIGHEST NORTH OF OCRACOKE. SMALL CRAFT ADVISORIES CONTINUE
FOR ALL COASTAL WATERS AND THE PAMLICO SOUND...WITH THE ALBEMARLE
SOUND AND RIVERS CAPPED AT 15-20 KNOTS.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 345 AM WED...SW WINDS 15 TO 25 KT WILL OCCUR AHEAD OF THE
FRONT INTO THURSDAY EVENING. THE FRONT WILL SLOWLY PUSH OFFSHORE
BY EARLY FRI WITH WINDS DIMINISHING AND BECOMING W TO NW 10 TO 15
KTS. SEAS SHLD SUBSIDE WITH SCA ENDING ALL WTRS BY FRI MORNING.
THE FRONT STALLS OFF THE COAST FRI INTO SAT THEN EDGES EAST SUNDAY
AS HIGH PRESSURE BUILDS OVER THE WATERS. EXPECT SUB ADVISORY
CONDITIONS FRIDAY AFTERNOON INTO SUNDAY WITH WESTERLY WINDS 15 KT
OR LESS AND SEAS 2-4 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT FRIDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR AMZ150-156-158.
&&
$$
SYNOPSIS...HSA
NEAR TERM...HSA/CQD
SHORT TERM...HSA
LONG TERM...BTC
AVIATION...BTC/HSA
MARINE...BTC/HSA/CQD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1235 PM EDT WED APR 30 2014
.SYNOPSIS... A LARGE AND VIGOROUS STORM SYSTEM OVER THE MIDWEST WILL
CONTINUE TO BRING UNSETTLED WEATHER TO THE REGION THIS AFTERNOON
THROUGH TONIGHT. A COLD FRONT WILL MOVE SLOWLY EASTWARD ACROSS THE
REGION THURSDAY INTO THURSDAY NIGHT. DRY AND COOLER WEATHER WILL
SPREAD IN FROM THE WEST FRIDAY AND SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1235 PM WEDNESDAY...
UPDATE... A LARGE MULTICELL COMPLEX HAS FORMED FROM CHARLESTON NORTH
INTO EAST-CENTRAL NC ALONG NUMEROUS MERGING BOUNDARIES. WHILE NOT
COINCIDENT WITH THE BEST DEEP LAYER SHEAR...LOW-LEVEL HELICITY
VALUES MAY STILL SUPPORT SOME EMBEDDED ROTATING STORMS. THE
ORIENTATION OF THE STORM CLUSTERS SUGGEST FLASH FLOODING MAY BE A
BIGGER CONCERN ALONG THE I-95 CORRIDOR...WHERE SEVERAL INCHES OF
RAIN FELL JUST YESTERDAY. WILL BE MAKING SOME EDITS TO THE FORECAST
TO REFLECT THE EASTWARD SHIFT IN FOCUS. -SMITH
THE WEDGE/WARM FRONT CONTINUES TO PUSH NORTHWEST AND IS JUST EAST
IF THE TRIAD...PUTTING NEARLY ALL OF CENTRAL NC IN THE WARM SECTOR
CHARACTERIZED BY LOWER 70 DEWPOINTS. REGIONALLY...THERE IS
WIDESPREAD CLOUD COVER FROM CONVECTION ALONG THE GULF COAST...BUT
SPC MESOANALYSIS SHOWS DESTABILIZATION ALREADY UNDERWAY IN THE WARM
SECTOR...AIDED BY RELATIVELY STEEP MID LEVEL LAPSE RATES BETWEEN
850MB AND 500MB PER THE KGSO 12Z RAOB. LATEST RAP SOUNDINGS SHOW
1000-2000 J/KG MLCAPE IN THE WARM SECTOR BY EARLY AFTERNOON. BULK
SHEAR CONTINUES TO BE STRONG WITH A CORRIDOR OF 45-50KT OVER THE
WESTERN HALF OF THE STATE. LOW-LEVEL HODOGRAPHS REMAIN CYCLONICALLY
CURVED WITH SOUTHEASTERLY SURFACE WINDS AND A 40KT 850MB FLOW OVER
THE CAROLINAS. OUTSIDE OF THE RETREATING WEDGE FRONT...TRIGGERS FOR
CONVECTION ARE A LITTLE MORE NEBULOUS...BUT CONVECTION IS ALREADY
ONGOING OVER CENTRAL SC...WITH A REMNANT MCV OVER THE SAVANNAH RIVER
BASIN. RAP VORT FORECASTS BRING THIS MCV OVER THE SANDHILLS IN THE
17-19Z TIME FRAME. THIS MAY THE MOST OBVIOUS FEATURE UPSTREAM TO
KEY ON...THOUGH CONVECTION SHOULD CONTINUE TO DEVELOP ALONG
DIFFERENTIAL HEATING AND OUTFLOW BOUNDARIES. ALL OF THESE
INGREDIENTS WILL SUPPORT SEVERE STORMS WITH THE POTENTIAL FOR LARGE
HAIL...DAMAGING WINDS AND ISOLATED TORNADOES.
GIVEN THAT THE TRIAD IS CLOSE TO BEING SCOURED OUT FO THE STABLE
AIRMASS...WILL FORECAST HIGHS IN THE 75-83 RANGE.
WHILE RAINFALL HAS BEEN A LITTLE LACK LUSTER OVER THE PIEDMONT...
STORM MOTION TODAY SHOULD STILL SUPPORT TRAINING OF CELLS....AND
AREAS ALONG THE I-95 CORRIDOR WERE MORE THAN PRIMED WITH LAST
EVENINGS RAINFALL. THUS...THE FLASH FLOOD WATCH WILL CONTINUE TODAY.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 330AM WEDNESDAY...
THURSDAY...THREAT FOR SCATTERED SHOWERS AND A FEW T-STORMS WILL
REMAIN BASICALLY EAST OF HIGHWAY 1 THROUGH MID DAY....AND EAST OF I-
95 THROUGH LATE AFTERNOON AS MID LEVEL TROUGH CROSSES THE REGION.
WIND PROFILES AND AVAILABLE INSTABILITY SUGGEST THAT STORMS SHOULD
REMAIN BELOW SEVERE CRITERIA. SLIGHTLY COOLER TEMPS THU WITH MAX
TEMPS RANGING BETWEEN THE MID 70S NE TO AROUND 80 SE.
A MORE STABLE...DRIER...COOLER AIR MASS WILL SETTLE OVER THE
FORECAST AREA THURSDAY NIGHT INTO FRIDAY. A WEAK UPPER DISTURBANCE
PASSING OVERHEAD FRIDAY AFTERNOON MAY TRIGGER AN ISOLATED SHOWER OR
TWO OVER OUR SE COUNTIES...IF ENOUGH MOISTURE IS AVAILABLE. MAX
TEMPS FRIDAY NEAR 70-LOWER 70S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 1225 PM TUESDAY...
WE SHOULD SEE LINGERING MID-HIGH CLOUDS ESPECIALLY IN THE ERN CWA
THROUGH MUCH OF SAT... AS A POTENT VORTICITY MAX CROSSES GA AND THE
CAROLINAS... BUT DRY/STABLE LOW LEVELS WILL INHIBIT PRECIP
DEVELOPMENT. OTHERWISE... ONCE THE MID LEVEL TROUGH AXIS FINALLY
SHIFTS TO OUR EAST SAT EVENING... EXPECT DRY AND SEASONABLE WEATHER
FOR SUNDAY. A STRONG MID LEVEL CLOSED LOW WILL TRACK ESE ACROSS THE
ST LAWRENCE VALLEY AND NEW ENGLAND SUNDAY... SETTLING JUST OFF THE
NEW ENGLAND COAST MON BEFORE WOBBLING TO THE EAST OR NE LATE TUE
THROUGH WED. TO OUR WEST... BROAD RIDGING OVER THE SW QUARTER OF THE
CONUS ON SUNDAY WILL SHIFT EASTWARD THROUGH THE CENTRAL STATES...
AMPLIFYING AS IT REACHES THE SOUTHEAST STATES BY WED. THIS WILL
RESULT IN GENERALLY FLAT NORTHWESTERLY MID LEVEL FLOW OVER THE
REGION. A BACKDOOR FRONTAL ZONE ORIENTED WEST-EAST ACROSS VA SUNDAY
IS EXPECTED TO DIP SOUTHWARD ACROSS NE NC MONDAY... THEN HOLD MAINLY
STATIONARY IN A NW-SE FASHION ALONG THE VA/NC BORDER AND NE NC
THROUGH TUE. IN THIS SORT OF A NORTHWEST FLOW PATTERN THERE IS THE
POTENTIAL FOR UPSTREAM CONVECTION OVER THE OH VALLEY TO TRACK
SOUTHEASTWARD ACROSS NC... AND FOR NOW WILL LEAVE IN A SLIGHT CHANCE
OF SHOWERS AND STORMS FOR MON/TUE TO ADDRESS THIS POTENTIAL. AS THE
RIDGE ALOFT APPROACHES FROM THE WEST LATE TUE INTO WED... THIS
BOUNDARY SHOULD BE PUSHED A BIT NORTHEASTWARD... WITH A DRYING
COLUMN AND WARMING LOW LEVELS. TEMPS CLOSE TO SEASONAL NORMALS
(WHICH IS LOW-MID 50S FOR LOWS AND MID-UPPER 70S FOR HIGHS) THROUGH
TUE... THEN ABOVE NORMAL TEMPS (HIGHS IN LOW-MID 80S) WED. -GIH
&&
.AVIATION /12Z WEDNESDAY THROUGH MONDAY/...
AS OF 750 AM WEDNESDAY...
LIFR CEILINGS WILL LINGER THROUGH 12-14Z IN THE TRIAD AS THE
RESIDUAL WEDGE AIRMASS GRADUALLY ERODES. THE WARM FRONT WILL LIFT
NORTH OF THE TRIAD IN THE MID MORNING...WITH WINDS VEERING TO
SOUTHERLY AND INCREASING TO 12-15KT WITH GUSTS TO 25KT.
WINDS WILL BE BREEZY OUT OF THE SOUTH...WITH 15 KNOTS GUSTING TO 25
KNOTS OVER THE AREA AFTER 15Z. CEILINGS WILL BE MAINLY MVFR AND
VISIBILITIES VFR OUTSIDE OF CONVECTION THROUGH AROUND 04Z...WITH
CEILINGS LOWERING TO IFR TONIGHT AS THE AIRMASS COOLS AND WINDS
SUBSIDE A BIT. THIS MAKES THE FORECAST DETAIL AND TIMING QUITE
PROBLEMATIC AS A DEEP PLUME OF MOISTURE OFF THE GULF WILL MAINTAIN
HIGH CHANCES OF CONVECTION ACROSS THE ENTIRE AREA TODAY...WITH THE
HIGHEST CHANCE OF STRONGER THUNDERSTORM ACTIVITY IN THE AFTERNOON
INTO EVENING...16Z-02Z WHEN INSTABILITY WILL PEAK DIURNALLY.
IN THE LONGER RANGE...THE SURFACE FRONT WILL BE SLOWLY EDGING
EAST...WITH LINGERING MVR CONDITIONS AND SHOWERS GRADUALLY IMPROVING
TO VFR IN THE WEST BY MID DAY THURSDAY. STRONGER CONVECTION WITH
THUNDER WILL LINGER IN THE EAST THROUGH AROUND SUNSET
THURSDAY...WITH IMPROVING CONDITIONS AROUND 00Z. A STRONGER COLD
FRONT WILL BE MOVING ACROSS THE AREA FRIDAY NIGHT/SATURDAY WITH VFR
CONDITIONS EXPECTED THURSDAY NIGHT THROUGH MONDAY
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR NCZ007>011-021>028-
038>043-073>078-083>086-088-089.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...SMITH
SHORT TERM...WSS
LONG TERM...HARTFIELD
AVIATION...MLM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1225 PM EDT WED APR 30 2014
.SYNOPSIS... A LARGE AND VIGOROUS STORM SYSTEM OVER THE MIDWEST WILL
CONTINUE TO BRING UNSETTLED WEATHER TO THE REGION THIS AFTERNOON
THROUGH TONIGHT. A COLD FRONT WILL MOVE SLOWLY EASTWARD ACROSS THE
REGION THURSDAY INTO THURSDAY NIGHT. DRY AND COOLER WEATHER WILL
SPREAD IN FROM THE WEST FRIDAY AND SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...
THE WEDGE/WARM FRONT CONTINUES TO PUSH NORTHWEST AND IS JUST EAST
IF THE TRIAD...PUTTING NEARLY ALL OF CENTRAL NC IN THE WARM SECTOR
CHARACTERIZED BY LOWER 70 DEWPOINTS. REGIONALLY...THERE IS
WIDESPREAD CLOUD COVER FROM CONVECTION ALONG THE GULF COAST...BUT
SPC MESOANALYSIS SHOWS DESTABILIZATION ALREADY UNDERWAY IN THE WARM
SECTOR...AIDED BY RELATIVELY STEEP MID LEVEL LAPSE RATES BETWEEN
850MB AND 500MB PER THE KGSO 12Z RAOB. LATEST RAP SOUNDINGS SHOW
1000-2000 J/KG MLCAPE IN THE WARM SECTOR BY EARLY AFTERNOON. BULK
SHEAR CONTINUES TO BE STRONG WITH A CORRIDOR OF 45-50KT OVER THE
WESTERN HALF OF THE STATE. LOW-LEVEL HODOGRAPHS REMAIN CYCLONICALLY
CURVED WITH SOUTHEASTERLY SURFACE WINDS AND A 40KT 850MB FLOW OVER
THE CAROLINAS. OUTSIDE OF THE RETREATING WEDGE FRONT...TRIGGERS FOR
CONVECTION ARE A LITTLE MORE NEBULOUS...BUT CONVECTION IS ALREADY
ONGOING OVER CENTRAL SC...WITH A REMNANT MCV OVER THE SAVANNAH RIVER
BASIN. RAP VORT FORECASTS BRING THIS MCV OVER THE SANDHILLS IN THE
17-19Z TIME FRAME. THIS MAY THE MOST OBVIOUS FEATURE UPSTREAM TO
KEY ON...THOUGH CONVECTION SHOULD CONTINUE TO DEVELOP ALONG
DIFFERENTIAL HEATING AND OUTFLOW BOUNDARIES. ALL OF THESE
INGREDIENTS WILL SUPPORT SEVERE STORMS WITH THE POTENTIAL FOR LARGE
HAIL...DAMAGING WINDS AND ISOLATED TORNADOES.
GIVEN THAT THE TRIAD IS CLOSE TO BEING SCOURED OUT FO THE STABLE
AIRMASS...WILL FORECAST HIGHS IN THE 75-83 RANGE.
WHILE RAINFALL HAS BEEN A LITTLE LACK LUSTER OVER THE PIEDMONT...
STORM MOTION TODAY SHOULD STILL SUPPORT TRAINING OF CELLS....AND
AREAS ALONG THE I-95 CORRIDOR WERE MORE THAN PRIMED WITH LAST
EVENINGS RAINFALL. THUS...THE FLASH FLOOD WATCH WILL CONTINUE TODAY.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 330AM WEDNESDAY...
THURSDAY...THREAT FOR SCATTERED SHOWERS AND A FEW T-STORMS WILL
REMAIN BASICALLY EAST OF HIGHWAY 1 THROUGH MID DAY....AND EAST OF I-
95 THROUGH LATE AFTERNOON AS MID LEVEL TROUGH CROSSES THE REGION.
WIND PROFILES AND AVAILABLE INSTABILITY SUGGEST THAT STORMS SHOULD
REMAIN BELOW SEVERE CRITERIA. SLIGHTLY COOLER TEMPS THU WITH MAX
TEMPS RANGING BETWEEN THE MID 70S NE TO AROUND 80 SE.
A MORE STABLE...DRIER...COOLER AIR MASS WILL SETTLE OVER THE
FORECAST AREA THURSDAY NIGHT INTO FRIDAY. A WEAK UPPER DISTURBANCE
PASSING OVERHEAD FRIDAY AFTERNOON MAY TRIGGER AN ISOLATED SHOWER OR
TWO OVER OUR SE COUNTIES...IF ENOUGH MOISTURE IS AVAILABLE. MAX
TEMPS FRIDAY NEAR 70-LOWER 70S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 1225 PM TUESDAY...
WE SHOULD SEE LINGERING MID-HIGH CLOUDS ESPECIALLY IN THE ERN CWA
THROUGH MUCH OF SAT... AS A POTENT VORTICITY MAX CROSSES GA AND THE
CAROLINAS... BUT DRY/STABLE LOW LEVELS WILL INHIBIT PRECIP
DEVELOPMENT. OTHERWISE... ONCE THE MID LEVEL TROUGH AXIS FINALLY
SHIFTS TO OUR EAST SAT EVENING... EXPECT DRY AND SEASONABLE WEATHER
FOR SUNDAY. A STRONG MID LEVEL CLOSED LOW WILL TRACK ESE ACROSS THE
ST LAWRENCE VALLEY AND NEW ENGLAND SUNDAY... SETTLING JUST OFF THE
NEW ENGLAND COAST MON BEFORE WOBBLING TO THE EAST OR NE LATE TUE
THROUGH WED. TO OUR WEST... BROAD RIDGING OVER THE SW QUARTER OF THE
CONUS ON SUNDAY WILL SHIFT EASTWARD THROUGH THE CENTRAL STATES...
AMPLIFYING AS IT REACHES THE SOUTHEAST STATES BY WED. THIS WILL
RESULT IN GENERALLY FLAT NORTHWESTERLY MID LEVEL FLOW OVER THE
REGION. A BACKDOOR FRONTAL ZONE ORIENTED WEST-EAST ACROSS VA SUNDAY
IS EXPECTED TO DIP SOUTHWARD ACROSS NE NC MONDAY... THEN HOLD MAINLY
STATIONARY IN A NW-SE FASHION ALONG THE VA/NC BORDER AND NE NC
THROUGH TUE. IN THIS SORT OF A NORTHWEST FLOW PATTERN THERE IS THE
POTENTIAL FOR UPSTREAM CONVECTION OVER THE OH VALLEY TO TRACK
SOUTHEASTWARD ACROSS NC... AND FOR NOW WILL LEAVE IN A SLIGHT CHANCE
OF SHOWERS AND STORMS FOR MON/TUE TO ADDRESS THIS POTENTIAL. AS THE
RIDGE ALOFT APPROACHES FROM THE WEST LATE TUE INTO WED... THIS
BOUNDARY SHOULD BE PUSHED A BIT NORTHEASTWARD... WITH A DRYING
COLUMN AND WARMING LOW LEVELS. TEMPS CLOSE TO SEASONAL NORMALS
(WHICH IS LOW-MID 50S FOR LOWS AND MID-UPPER 70S FOR HIGHS) THROUGH
TUE... THEN ABOVE NORMAL TEMPS (HIGHS IN LOW-MID 80S) WED. -GIH
&&
.AVIATION /12Z WEDNESDAY THROUGH MONDAY/...
AS OF 750 AM WEDNESDAY...
LIFR CEILINGS WILL LINGER THROUGH 12-14Z IN THE TRIAD AS THE
RESIDUAL WEDGE AIRMASS GRADUALLY ERODES. THE WARM FRONT WILL LIFT
NORTH OF THE TRIAD IN THE MID MORNING...WITH WINDS VEERING TO
SOUTHERLY AND INCREASING TO 12-15KT WITH GUSTS TO 25KT.
WINDS WILL BE BREEZY OUT OF THE SOUTH...WITH 15 KNOTS GUSTING TO 25
KNOTS OVER THE AREA AFTER 15Z. CEILINGS WILL BE MAINLY MVFR AND
VISIBILITIES VFR OUTSIDE OF CONVECTION THROUGH AROUND 04Z...WITH
CEILINGS LOWERING TO IFR TONIGHT AS THE AIRMASS COOLS AND WINDS
SUBSIDE A BIT. THIS MAKES THE FORECAST DETAIL AND TIMING QUITE
PROBLEMATIC AS A DEEP PLUME OF MOISTURE OFF THE GULF WILL MAINTAIN
HIGH CHANCES OF CONVECTION ACROSS THE ENTIRE AREA TODAY...WITH THE
HIGHEST CHANCE OF STRONGER THUNDERSTORM ACTIVITY IN THE AFTERNOON
INTO EVENING...16Z-02Z WHEN INSTABILITY WILL PEAK DIURNALLY.
IN THE LONGER RANGE...THE SURFACE FRONT WILL BE SLOWLY EDGING
EAST...WITH LINGERING MVR CONDITIONS AND SHOWERS GRADUALLY IMPROVING
TO VFR IN THE WEST BY MID DAY THURSDAY. STRONGER CONVECTION WITH
THUNDER WILL LINGER IN THE EAST THROUGH AROUND SUNSET
THURSDAY...WITH IMPROVING CONDITIONS AROUND 00Z. A STRONGER COLD
FRONT WILL BE MOVING ACROSS THE AREA FRIDAY NIGHT/SATURDAY WITH VFR
CONDITIONS EXPECTED THURSDAY NIGHT THROUGH MONDAY
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR NCZ007>011-021>028-
038>043-073>078-083>086-088-089.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...WSS/SMITH
SHORT TERM...WSS
LONG TERM...HARTFIELD
AVIATION...MLM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1244 PM CDT WED APR 30 2014
.UPDATE...
ISSUED AT 1242 PM CDT WED APR 30 2014
MAINLY DEALING WITH AREAS OF VERY LIGHT RAIN OR DRIZZLE THROUGH
THE EARLY AFTERNOON. A SLIGHT REDUCTION IN POPS IS PLANNED.
PREVIOUS UPDATE ISSUED AT 935 AM CDT WED APR 30 2014.
NO SIGNIFICANT CHANGES TO THE PACKAGE ARE PLANNED FOR THIS
MORNING...JUST A FEW SUBTLE POP TWEEKS. IR SATELLITE IMAGERY SHOWS
THAT COOLEST CLOUD TOPS HAVE NOW ROTATED WEST OF AN HCO-GFK- OAKES
LINE...WITH VERY LIGHT RAIN OR MIST LINGERING BEHIND. ADDITIONAL
BANDED PRECIP IS SHOWING ON RADAR FM FSE INTO BJI AND GPZ...MOVING
WESTWARD...WITH HRRR SHOWING OVERALL REGEN OF PRECIP ACROSS
NORTHWESTERN MN BY MIDDAY.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 400 AM CDT WED APR 30 2014
THE MAIN CHALLENGE WILL BE PRECIP OVER THE NEXT SEVERAL DAYS AND
TEMPS. MODELS CONTINUE IN VERY GOOD OVERALL AGREEMENT...WITH NO
PREFERENCE THIS MORNING.
FOR TODAY...IT WILL BE A VERY COLD AND RAINY DAY FOR THE REGION.
THERE COULD BE SOME SNOW FLAKES MIXING IN AT TIMES BEFORE
18Z...NEAR ANY HEAVIER PRECIP BANDS. NOT EXPECTING ANY SNOW
ACCUMULATION THOUGH. TEMPS WILL BE WELL BELOW NORMAL AND BE IN THE
LOW/MID 40S. IT WILL BE WINDY WITH 35-40KT TO M
FOR TONIGHT...THE RAIN WILL LINGER AS THE SLOW MOVING CLOSED LOW
BEGINS TO MOVE EAST LATE. THERE COULD ONCE AGAIN BE A FEW SNOW
FLAKES MIXING IN AFTER 06Z THU...BUT NO SNOW ACCUMS EXPECTED.
ON THURSDAY...THE AREA SHOULD SLOWLY DRY OUT FROM WEST TO EAST.
THERE COULD EVEN BE SUNSHINE ALONG AND WEST OF THE VALLEY BY
AFTERNOON...AND TEMPS SHOULD RESPOND AND WARM INTO THE MID 50S.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 400 AM CDT WED APR 30 2014
FOR THU NIGHT THROUGH FRI NIGHT...SEVERAL SHORTWAVES WILL ROTATE
THROUGH THE REGION. THERE WILL BE CHANCES FOR MAINLY LIGHT RAIN AT
TIMES...WITH THE BEST WAVE THU NIGHT INTO FRI. THERE COULD ALSO BE
SOME SUNSHINE FRI AFTERNOON...WITH TEMPS INTO THE MID 50S FOR MOST
AREAS.
FOR SAT THROUGH TUE...THE LONG WAVE TRANSITIONS FROM A HIGH
AMPLITUDE PATTERN AT THE BEGINNING OF THE PERIOD TO A ZONAL
PATTERN BY THE END OF THE PERIOD. GIVEN THE ZONAL FLOW TEMPERATURES
WILL STAY BELOW NORMAL. WARM ADVECTION PRECIP EXPECTED IN THE SUN
NIGHT THROUGH WED TIME FRAME.
THE GFS WAS FASTER THAN THE ECWMF THROUGH THE PERIOD AND WILL BE
PREFERRED. PRECIP WAS TAKEN OUT SAT NIGHT.
LITTLE CHANGE TO TEMPS FOR THE PERIOD EXCEPT A COUPLE DEGREES HIGHER
FOR TUE IN THE SOUTHERN VALLEY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1242 PM CDT WED APR 30 2014
PRIMARY CHALLENGES FOR TAF SITES WILL BE CIGS AND PRECIP TYPE.
EXPECT ON AN OFF LIGHT RAIN...DRIZZLE OR SOME BRIEF PERIODS OF
VERY LIGHT SNOW TO BE MIXED IN THROUGH THE AFTN AND EVENING.
PRECIP LIGHT ENOUGH IT IS DIFFICULT TO DETECT ON RADAR...BUT MOST
AFTN SHOULD BE EITHER DRY OR RAIN LIGHT ENOUGH TO NOT RESTRICT
VSBYS. CIGS...HOWEVER...WILL FLUCTUATE FROM MVFR TO IFR THROUGH
THE TAF PERIODS. EXPECT NORTHERLY WINDS GUSTING 20 TO 30 MPH
THROUGH 18Z AS WELL.
&&
.HYDROLOGY...
ISSUED AT 1242 PM CDT WED APR 30 2014
MODERATE FLOODING CONTINUES AT ABERCROMBIE WITH ITS CREST TODAY
NEAR 17 FT AOA 4K CFS. THE CREST ON THE RED RIVER IS THROUGH
WAHPETON AND HEADING NORTH WITH 6K CFS. THE ABERCROMBIE WATER WILL
MERGE INTO THE RED SOUTH OF FARGO IN THE NEXT 36 HRS WITH THE RED
WATER SHORTLY THEREAFTER CAUSING 27 TO 28 FT TO BE REALIZED WITH
AROUND 10K CFS BY THE END OF THE WEEK.
THIS FARGO CREST WILL MOVE ITS WAY NORTHWARD WITH WARNINGS ISSUED
TODAY FOR GRAND FORKS...MINOR...AND OSLO...MODERATE AND A WATCH FOR
DRAYTON. ELSEWHERE SABIN AND HARWOOD ARE CRESTING TODAY AS IS HAWLEY
BUT BELOW FLOOD STAGE SO THE WARNING WAS CANCELLED. HENDRUM WILL
RISE ABOVE FLOOD STAGE AS BACKWATERS RETREAT UP THE WILD RICE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...FLOOD WARNINGS ALONG THE WILD RICE AND RED RIVERS.
MN...FLOOD WARNINGS ALONG THE BUFFALO...TWO RIVERS... AND RED
RIVERS.
$$
UPDATE...GUST
SHORT TERM...DK
LONG TERM...HOPPES/DK
AVIATION...SPEICHER
HYDROLOGY...JK
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
559 PM EDT WED APR 30 2014
.SYNOPSIS...
A LARGE UPPER LEVEL LOW OVER THE NORTHERN PLAINS WILL MAKE SLOW
EASTWARD PROGRESS INTO THE GREAT LAKES REGION BY TONIGHT. AT THE
SURFACE...A COLD FRONT WILL ADVANCE ACROSS THE APPALACHIANS BY
THIS EVENING...AND THEN CONTINUE TO MOVE SLOWLY OFF THE EAST COAST
OVERNIGHT. DEEP LOW LEVEL MOISTURE TRANSPORTED NORTHWARD FROM THE
GULF OF MEXICO AHEAD OF THE COLD FRONT WILL SUPPORT WIDESPREAD
MODERATE TO HEAVY RAINFALL THROUGH TONIGHT. FLOOD WATCHES REMAIN
IN EFFECT FOR SOUTHEASTERN PORTIONS OF THE KEYSTONE STATE THROUGH
THURSDAY MORNING.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
RADAR MOSAIC SHOWS EXTENSIVE BREAK IN PCPN ACROSS CENTRAL PA THIS
AFTN. PLUME OF MDT TO HVY SHOWERS WILL CONTINUE ACROSS SRN
LANCASTER COUNTY OVER THE NEXT COUPLE OF HOURS...WITH COVERAGE
LIKELY EXPANDING WESTWARD AND CELLS LIFT NWD FROM MD.
LATER THIS EVENING EXPECT SHOWER TO REDEVELOP OVER WRN COUNTIES
PRIOR TO 00Z THEN MOVE EAST THROUGH THE LATE EVENING HOURS AS
COLD FRONT IS PUSHED EAST BY SLOW MOVING UPPER LOW CENTER.
LATEST HRRR RUNS ARE LESS IMPRESSIVE WITH DEVELOPMENT OF
CONVECTIVE LINE ALONG/IN ADVANCE OF THE FRONT BUT CONTINUE TO
SHOWS AREA OF CONVECTION PERSISTING/MOVING EAST ACROSS CENTRAL PA
THROUGH MIDNIGHT.
PVS DISC...
RICH GOMEX MOISTURE WITH PWATS RUNNING 1-1.5+ INCHES
OR +2-3SD ABOVE THE MEAN WILL BE IN PLACE AHEAD OF SFC COLD FRONT
VIA STG DEEP LYR SLY FLOW ON THE EASTSIDE OF LARGE SLOW-MOVG
MID/UPPER LEVEL LOW...WHICH IS MAKING SLOW EWD PROGRESS ACRS THE
UPPER MIDWEST THIS PD. BROAD WARM ADVECTION WILL PERSIST THROUGH
THROUGH TODAY...AND OVERRUNNING PRECIPITATION WILL BECOME
INCREASINGLY ENHANCED BY EMBEDDED/ELEVATED CONVECTION AS A WARM
FRONT LIFTS NWD FROM NORTH CAROLINA. THE PERSISTENT MID LEVEL WARM
ADVECTION WILL BE FOLLOWED BY NEAR-SURFACE OR SURFACE BASED
CONVECTION AND ENHANCED LLVL CONVERGENCE INVOF TRIPLE PT LOW
DURING THE AFTERNOON/EVE ACROSS SCENT AND SERN PA. MODEL QPFS HAVE
BEEN RELATIVELY STEADY IN THIS REGION...SUGGESTING AT LEAST 2-3
INCH AREAL AVERAGE RAINFALL AMTS WITH LOCALLY HIGHER AMOUNTS PSBL.
THESE AMTS SHOULD RESULT IN AT LEAST MINOR FLOODING...WITH
POTENTIAL FOR MORE SIGNIFICANT AREAL/SMALL STREAM AND LOCALIZED
FLASH FLOODING DUE TO ISOLATED 1"+ SHORT DURATION TOTALS.
WPC EXPANDED THE EXCESSIVE RAFL OUTLOOK TO INCLUDE NEARLY ALL OF
THE CWA. CONFIDENCE IN THE QPF DETAILS IS LOW GIVEN RECENT
PERFORMANCE AND WIDE SPREAD IN THE DETAILS...BUT WITH SUCH A
FAVORABLE PATTERN WITH SUPPORTING KEY INGREDIENTS AND NORTH-SOUTH
TRAINING STARTING TO SHOW ITS HAND WOULD STILL LEAN TOWARD THE
HIGHER END AMTS. PLACEMENT OF FLOOD WATCH STILL LOOKS VERY GOOD
WITH CONVECTIVELY ENHANCED RAINS FILLING IN ACRS NC NWD THRU VA
AND MD.
WHILE HEAVY RAIN AND FLOODING ARE THE PRIMARY CONCERNS IN TERMS OF
SIGNIFICANT WEATHER HAZARDS...THERE REMAINS A RELATIVELY LOWER
THREAT FOR A FEW STG TO SVR TSTMS MAINLY OVER THE SRN 1/3 OF THE
CWA THIS AFTN INTO THE EVE. THIS AREA IS JUST NORTH OF THE DAY 1
SPC SLGT RISK LINE. MODEL DATA CONTINUES TO SUGGEST COMBO OF WEAK
INSTABILITY AND STG FLOW ALOFT/SHEAR PROFILES MAY BE SUPPORTIVE OF
A FEW ORGANIZED LOW-TOPPED STORMS/BANDS WITH SOME ROTATING CELLS
POSSIBLE GIVEN VEERING IN THE LOWEST FEW KM.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
THE CLOSED H5 LOW LIFTS NEWD ACROSS THE GREAT LAKES INTO THE ST.
LAWRENCE VALLEY ON DAY 2. MODEL DATA SUPPORTS SCATTERED SHOWER
ACTIVITY WITH LGT AMTS IN MUCH DRIER CYCLONIC FLOW REGIME.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
UPPER LOW RESPONSIBLE FOR RAINY CONDITIONS THIS MIDWEEK WILL SLIDE
NE ALONG THE ST LAWRENCE SEAWAY FRI INTO SAT...BUT BROAD TROUGH
WILL REMAIN PERSISTENT OVER GREAT LAKES THROUGH THE WEEKEND. THIS
WLL KEEP THE WEATHER SOMEWHAT UNSETTLED OVER PA...ESP NW HALF...AS
WEAK WAVES SLIDING THROUGH MAIN FLOW COMBINED WITH LIMITED
INSTABILITY DUE TO COOL AIR ALOFT TO KEEP MENTION OF SCT LIGHT
SHOWERS IN THE FORECAST FOR SEVERAL DAYS. BEST PROB FOR MORE
WIDESPREAD /BUT MAINLY LIGHT/ SHOWERS WILL BE SUNDAY AS A STRONGER
WAVE/CLIPPER PUSHES THROUGH. TEMPS DURING THIS PERIOD WILL BE
SEVERAL DEGREES BELOW NORMAL IN PERSISTENT W/NW FLOW...WITH BREEZY
CONDITIONS ON FRI FOLLOWED BY AN EVEN STIFFER WIND SAT NIGHT INTO
MON.
ONCE THE CLIPPER SLIDES THROUGH...A BROAD RIDGE OVER CENTRAL U.S.
WILL WORK ITS WAY EASTWARD...BRINGING A PERIOD OF MORE SETTLED
WEATHER FOR MON NIGHT-WED WITH TEMPERATURES GRADUALLY MODIFYING
BACK TO SEASONAL NORMALS.
NEXT MIDWEEK COULD AGAIN BRING UNSETTLED WEATHER AS A WARM FRONT
LIFTS THROUGH THE OHIO VALLEY...WITH SHOWERS LIKELY ALONG WITH A
NOTICABLE WARMUP FOR LATE WEEK.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
MOIST SERLY FLOW INTO THE REGION TO THE NORTH OF A WARM FRONT
OVER THE CAROLINAS/VA AND A COLD FRONT IN THE OHIO VALLEY WILL
KEEP WIDESPREAD MVFR/IFR IN PLACE INTO THE OVERNIGHT WITH ON AND
OFF OR SHOWERS. A THUNDERSTORM IS POSSIBLE OVER THE SOUTHEAST.
COLD FRONT IS FORECAST TO MOVE THROUGH OVERNIGHT TURNING SFC
WINDS TO THE SW AND BRINGING WIDESPREAD PCPN TO AN END. CIG/VIZ
WILL ALSO BEGIN TO IMPROVE.
.OUTLOOK...
.THU...IMPROVING CONDS AFTER AM LOW CIGS/RAIN.
.FRI...NO SIG WX EXPECTED.
.SAT-SUN...SCT SHRA POSS W/ CFROPA.
.MON...NO SIG WX EXPECTED.
&&
.HYDROLOGY...
NO CHANGES TO THE FLOOD WATCH TAKING INTO ACCOUNT RADAR TRENDS
AND LATEST MODELS CONTINUING TO DEPICT THE HEAVIEST RAINS OVER THE
WATCH AREA. OBSERVED RAINFALL AMOUNTS OF 2 TO 3 INCHES SO FAR
ACROSS LOWER SUSQUEHANNA VALLEY. SOME CONCERN FOR LOCALIZED FLASH
FLOODING WITH EMBEDDED TSTMS LKLY FOLLOWING PERSISTENT OVERRUNNING
WITH CONVECTIVE ENHANCEMENT. THE RISK FOR EXCESSIVE RAINFALL IS
CERTAINLY ELEVATED WITH AT LEAST SOME MINOR FLOODING LKLY TO
OCCUR. THE PATTERN IS VERY FAVORABLE WITH RELATIVELY HIGH
CONFIDENCE IN HEAVY TO POTENTIALLY EXCESSIVE/LOCALIZED AMOUNTS.
CONCERNING FCST POINTS...THE LOWER MAIN STEM SUSQ TRIBS AND
JUNIATA BASIN POINTS ARE MOST LKLY TO EXCEED FLOOD STAGES...AND
DAYSHIFT WILL NEED TO CONSIDER ISSUING FLW`S. THE CRESTS WILL BE
TIED TO QPF WITH PREVIOUS BASE FLOWS AVERAGING NEAR NORMAL FOR
LATE APRIL.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH THURSDAY MORNING FOR PAZ026>028-035-036-
049>053-056>059-063>066.
&&
$$
SYNOPSIS...GARTNER/STEINBUGL
NEAR TERM...GARTNER
SHORT TERM...GARTNER/STEINBUGL
LONG TERM...RXR
AVIATION...LA CORTE/GARTNER
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
324 PM EDT WED APR 30 2014
.SYNOPSIS...
A LARGE UPPER LEVEL LOW OVER THE NORTHERN PLAINS WILL MAKE SLOW
EASTWARD PROGRESS INTO THE GREAT LAKES REGION BY TONIGHT. AT THE
SURFACE...A COLD FRONT WILL ADVANCE ACROSS THE APPALACHIANS BY
THIS EVENING...AND THEN CONTINUE TO MOVE SLOWLY OFF THE EAST COAST
OVERNIGHT. DEEP LOW LEVEL MOISTURE TRANSPORTED NORTHWARD FROM THE
GULF OF MEXICO AHEAD OF THE COLD FRONT WILL SUPPORT WIDESPREAD
MODERATE TO HEAVY RAINFALL THROUGH TONIGHT. FLOOD WATCHES REMAIN
IN EFFECT FOR SOUTHEASTERN PORTIONS OF THE KEYSTONE STATE THROUGH
THURSDAY MORNING.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
RADAR MOSAIC SHOWS EXTENSIVE BREAK IN PCPN ACROSS CENTRAL PA THIS
AFTN. PLUME OF MDT TO HVY SHOWERS WILL CONTINUE ACROSS SRN
LANCASTER COUNTY OVER THE NEXT COUPLE OF HOURS...WITH COVERAGE
LIKELY EXPANDING WESTWARD AND CELLS LIFT NWD FROM MD.
LATER THIS EVENING EXPECT SHOWER TO REDEVELOP OVER WRN COUNTIES
PRIOR TO 00Z THEN MOVE EAST THROUGH THE LATE EVENING HOURS AS
COLD FRONT IS PUSHED EAST BY SLOW MOVING UPPER LOW CENTER.
LATEST HRRR RUNS ARE LESS IMPRESSIVE WITH DEVELOPMENT OF
CONVECTIVE LINE ALONG/IN ADVANCE OF THE FRONT BUT CONTINUE TO
SHOWS AREA OF CONVECTION PERSISTING/MOVING EAST ACROSS CENTRAL PA
THROUGH MIDIGHT.
PVS DISC...
RICH GOMEX MOISTURE WITH PWATS RUNNING 1-1.5+ INCHES
OR +2-3SD ABOVE THE MEAN WILL BE IN PLACE AHEAD OF SFC COLD FRONT
VIA STG DEEP LYR SLY FLOW ON THE EASTSIDE OF LARGE SLOW-MOVG
MID/UPPER LEVEL LOW...WHICH IS MAKING SLOW EWD PROGRESS ACRS THE
UPPER MIDWEST THIS PD. BROAD WARM ADVECTION WILL PERSIST THROUGH
THROUGH TODAY...AND OVERRUNNING PRECIPITATION WILL BECOME
INCREASINGLY ENHANCED BY EMBEDDED/ELEVATED CONVECTION AS A WARM
FRONT LIFTS NWD FROM NORTH CAROLINA. THE PERSISTENT MID LEVEL WARM
ADVECTION WILL BE FOLLOWED BY NEAR-SURFACE OR SURFACE BASED
CONVECTION AND ENHANCED LLVL CONVERGENCE INVOF TRIPLE PT LOW
DURING THE AFTERNOON/EVE ACROSS SCENT AND SERN PA. MODEL QPFS HAVE
BEEN RELATIVELY STEADY IN THIS REGION...SUGGESTING AT LEAST 2-3
INCH AREAL AVERAGE RAINFALL AMTS WITH LOCALLY HIGHER AMOUNTS PSBL.
THESE AMTS SHOULD RESULT IN AT LEAST MINOR FLOODING...WITH
POTENTIAL FOR MORE SIGNIFICANT AREAL/SMALL STREAM AND LOCALIZED
FLASH FLOODING DUE TO ISOLATED 1"+ SHORT DURATION TOTALS.
WPC EXPANDED THE EXCESSIVE RAFL OUTLOOK TO INCLUDE NEARLY ALL OF
THE CWA. CONFIDENCE IN THE QPF DETAILS IS LOW GIVEN RECENT
PERFORMANCE AND WIDE SPREAD IN THE DETAILS...BUT WITH SUCH A
FAVORABLE PATTERN WITH SUPPORTING KEY INGREDIENTS AND NORTH-SOUTH
TRAINING STARTING TO SHOW ITS HAND WOULD STILL LEAN TOWARD THE
HIGHER END AMTS. PLACEMENT OF FLOOD WATCH STILL LOOKS VERY GOOD
WITH CONVECTIVELY ENHANCED RAINS FILLING IN ACRS NC NWD THRU VA
AND MD.
WHILE HEAVY RAIN AND FLOODING ARE THE PRIMARY CONCERNS IN TERMS OF
SIGNIFICANT WEATHER HAZARDS...THERE REMAINS A RELATIVELY LOWER
THREAT FOR A FEW STG TO SVR TSTMS MAINLY OVER THE SRN 1/3 OF THE
CWA THIS AFTN INTO THE EVE. THIS AREA IS JUST NORTH OF THE DAY 1
SPC SLGT RISK LINE. MODEL DATA CONTINUES TO SUGGEST COMBO OF WEAK
INSTABILITY AND STG FLOW ALOFT/SHEAR PROFILES MAY BE SUPPORTIVE OF
A FEW ORGANIZED LOW-TOPPED STORMS/BANDS WITH SOME ROTATING CELLS
POSSIBLE GIVEN VEERING IN THE LOWEST FEW KM.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
THE CLOSED H5 LOW LIFTS NEWD ACROSS THE GREAT LAKES INTO THE ST.
LAWRENCE VALLEY ON DAY 2. MODEL DATA SUPPORTS SCATTERED SHOWER
ACTIVITY WITH LGT AMTS IN MUCH DRIER CYCLONIC FLOW REGIME.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
UPPER LOW RESPONSIBLE FOR RAINY CONDITIONS THIS MIDWEEK WILL SLIDE
NE ALONG THE ST LAWRENCE SEAWAY FRI INTO SAT...BUT BROAD TROUGH
WILL REMAIN PERSISTENT OVER GREAT LAKES THROUGH THE WEEKEND. THIS
WLL KEEP THE WEATHER SOMEWHAT UNSETTLED OVER PA...ESP NW HALF...AS
WEAK WAVES SLIDING THROUGH MAIN FLOW COMBINED WITH LIMITED
INSTABILITY DUE TO COOL AIR ALOFT TO KEEP MENTION OF SCT LIGHT
SHOWERS IN THE FORECAST FOR SEVERAL DAYS. BEST PROB FOR MORE
WIDESPREAD /BUT MAINLY LIGHT/ SHOWERS WILL BE SUNDAY AS A STRONGER
WAVE/CLIPPER PUSHES THROUGH. TEMPS DURING THIS PERIOD WILL BE
SEVERAL DEGREES BELOW NORMAL IN PERSISTENT W/NW FLOW...WITH BREEZY
CONDITIONS ON FRI FOLLOWED BY AN EVEN STIFFER WIND SAT NIGHT INTO
MON.
ONCE THE CLIPPER SLIDES THROUGH...A BROAD RIDGE OVER CENTRAL U.S.
WILL WORK ITS WAY EASTWARD...BRINGING A PERIOD OF MORE SETTLED
WEATHER FOR MON NIGHT-WED WITH TEMPERATURES GRADUALLY MODIFYING
BACK TO SEASONAL NORMALS.
NEXT MIDWEEK COULD AGAIN BRING UNSETTLED WEATHER AS A WARM FRONT
LIFTS THROUGH THE OHIO VALLEY...WITH SHOWERS LIKELY ALONG WITH A
NOTICABLE WARMUP FOR LATE WEEK.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
MOIST SERLY FLOW INTO THE REGION TO THE NORTH OF A WARM FRONT
OVER THE CAROLINAS/VA AND A COLD FRONT IN THE OHIO VALLEY WILL
PERSIST AT LEAST THROUGH THE EVENING HOURS. THIS WILL MAINTAIN
POOR FLYING CONDS ACROSS ALL OF CENTRAL PA WITH IFR CIGS AND ON
AND OFF OR HEAVIER SHOWERS.
COLD FRONT IS FORECAST TO MOVE THROUGH WEST TO EAST OVERNIGHT
TURNING SFC WINDS TO THE SW AND BRINGING WIDESPREAD PCPN TO AN
END.
.OUTLOOK...
.THU...IMPROVING CONDS AFTER AM LOW CIGS/RAIN.
.FRI...NO SIG WX EXPECTED.
.SAT-SUN...SCT SHRA POSS W/ CFROPA.
&&
.HYDROLOGY...
NO CHANGES TO THE FLOOD WATCH TAKING INTO ACCOUNT RADAR TRENDS
AND LATEST MODELS CONTINUING TO DEPICT THE HEAVIEST RAINS OVER THE
WATCH AREA. OBSERVED RAINFALL AMOUNTS OF 2 TO 3 INCHES SO FAR
ACROSS LOWER SUSQUEHANNA VALLEY. SOME CONCERN FOR LOCALIZED FLASH
FLOODING WITH EMBEDDED TSTMS LKLY FOLLOWING PERSISTENT OVERRUNNING
WITH CONVECTIVE ENHANCEMENT. THE RISK FOR EXCESSIVE RAINFALL IS
CERTAINLY ELEVATED WITH AT LEAST SOME MINOR FLOODING LKLY TO
OCCUR. THE PATTERN IS VERY FAVORABLE WITH RELATIVELY HIGH
CONFIDENCE IN HEAVY TO POTENTIALLY EXCESSIVE/LOCALIZED AMOUNTS.
CONCERNING FCST POINTS...THE LOWER MAIN STEM SUSQ TRIBS AND
JUNIATA BASIN POINTS ARE MOST LKLY TO EXCEED FLOOD STAGES...AND
DAYSHIFT WILL NEED TO CONSIDER ISSUING FLW`S. THE CRESTS WILL BE
TIED TO QPF WITH PREVIOUS BASE FLOWS AVERAGING NEAR NORMAL FOR
LATE APRIL.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH THURSDAY MORNING FOR PAZ026>028-035-036-
049>053-056>059-063>066.
&&
$$
SYNOPSIS...GARTNER/STEINBUGL
NEAR TERM...GARTNER
SHORT TERM...GARTNER/STEINBUGL
LONG TERM...RXR
AVIATION...GARTNER
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
301 PM EDT WED APR 30 2014
.SYNOPSIS...
A LARGE UPPER LEVEL LOW OVER THE NORTHERN PLAINS WILL MAKE SLOW
EASTWARD PROGRESS INTO THE GREAT LAKES REGION BY TONIGHT. AT THE
SURFACE...A COLD FRONT WILL ADVANCE ACROSS THE APPALACHIANS BY
THIS EVENING...AND THEN CONTINUE TO MOVE SLOWLY OFF THE EAST COAST
OVERNIGHT. DEEP LOW LEVEL MOISTURE TRANSPORTED NORTHWARD FROM THE
GULF OF MEXICO AHEAD OF THE COLD FRONT WILL SUPPORT WIDESPREAD
MODERATE TO HEAVY RAINFALL THROUGH TONIGHT. FLOOD WATCHES REMAIN
IN EFFECT FOR SOUTHEASTERN PORTIONS OF THE KEYSTONE STATE THROUGH
THURSDAY MORNING.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
RADAR MOSAIC SHOWS EXTENSIVE BREAK IN PCPN ACROSS CENTRAL PA THIS
AFTN. PLUME OF MDT TO HVY SHOWERS WILL CONTINUE ACROSS SRN
LANCASTER COUNTY OVER THE NEXT COUPLE OF HOURS...WITH COVERAGE
LIKELY EXPANDING WESTWARD AND CELLS LIFT NWD FROM MD.
LATER THIS EVENING EXPECT SHOWER TO REDEVELOP OVER WRN COUNTIES
PRIOR TO 00Z THEN MOVE EAST THROUGH THE LATE EVENING HOURS AS
COLD FRONT IS PUSHED EAST BY SLOW MOVING UPPER LOW CENTER.
LATEST HRRR RUNS ARE LESS IMPRESSIVE WITH DEVELOPMENT OF
CONVECTIVE LINE ALONG/IN ADVANCE OF THE FRONT BUT CONTINUE TO
SHOWS AREA OF CONVECTION PERSISTING/MOVING EAST ACROSS CENTRAL PA
THROUGH MIDIGHT.
PVS DISC...
RICH GOMEX MOISTURE WITH PWATS RUNNING 1-1.5+ INCHES
OR +2-3SD ABOVE THE MEAN WILL BE IN PLACE AHEAD OF SFC COLD FRONT
VIA STG DEEP LYR SLY FLOW ON THE EASTSIDE OF LARGE SLOW-MOVG
MID/UPPER LEVEL LOW...WHICH IS MAKING SLOW EWD PROGRESS ACRS THE
UPPER MIDWEST THIS PD. BROAD WARM ADVECTION WILL PERSIST THROUGH
THROUGH TODAY...AND OVERRUNNING PRECIPITATION WILL BECOME
INCREASINGLY ENHANCED BY EMBEDDED/ELEVATED CONVECTION AS A WARM
FRONT LIFTS NWD FROM NORTH CAROLINA. THE PERSISTENT MID LEVEL WARM
ADVECTION WILL BE FOLLOWED BY NEAR-SURFACE OR SURFACE BASED
CONVECTION AND ENHANCED LLVL CONVERGENCE INVOF TRIPLE PT LOW
DURING THE AFTERNOON/EVE ACROSS SCENT AND SERN PA. MODEL QPFS HAVE
BEEN RELATIVELY STEADY IN THIS REGION...SUGGESTING AT LEAST 2-3
INCH AREAL AVERAGE RAINFALL AMTS WITH LOCALLY HIGHER AMOUNTS PSBL.
THESE AMTS SHOULD RESULT IN AT LEAST MINOR FLOODING...WITH
POTENTIAL FOR MORE SIGNIFICANT AREAL/SMALL STREAM AND LOCALIZED
FLASH FLOODING DUE TO ISOLATED 1"+ SHORT DURATION TOTALS.
WPC EXPANDED THE EXCESSIVE RAFL OUTLOOK TO INCLUDE NEARLY ALL OF
THE CWA. CONFIDENCE IN THE QPF DETAILS IS LOW GIVEN RECENT
PERFORMANCE AND WIDE SPREAD IN THE DETAILS...BUT WITH SUCH A
FAVORABLE PATTERN WITH SUPPORTING KEY INGREDIENTS AND NORTH-SOUTH
TRAINING STARTING TO SHOW ITS HAND WOULD STILL LEAN TOWARD THE
HIGHER END AMTS. PLACEMENT OF FLOOD WATCH STILL LOOKS VERY GOOD
WITH CONVECTIVELY ENHANCED RAINS FILLING IN ACRS NC NWD THRU VA
AND MD.
WHILE HEAVY RAIN AND FLOODING ARE THE PRIMARY CONCERNS IN TERMS OF
SIGNIFICANT WEATHER HAZARDS...THERE REMAINS A RELATIVELY LOWER
THREAT FOR A FEW STG TO SVR TSTMS MAINLY OVER THE SRN 1/3 OF THE
CWA THIS AFTN INTO THE EVE. THIS AREA IS JUST NORTH OF THE DAY 1
SPC SLGT RISK LINE. MODEL DATA CONTINUES TO SUGGEST COMBO OF WEAK
INSTABILITY AND STG FLOW ALOFT/SHEAR PROFILES MAY BE SUPPORTIVE OF
A FEW ORGANIZED LOW-TOPPED STORMS/BANDS WITH SOME ROTATING CELLS
POSSIBLE GIVEN VEERING IN THE LOWEST FEW KM.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
THE CLOSED H5 LOW LIFTS NEWD ACROSS THE GREAT LAKES INTO THE ST.
LAWRENCE VALLEY ON DAY 2. MODEL DATA SUPPORTS SCATTERED SHOWER
ACTIVITY WITH LGT AMTS IN MUCH DRIER CYCLONIC FLOW REGIME.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
UPPER LOW SLIDES INTO S ONTARIO BY FRI AS IT TRANSITIONS TO AN
OPEN WAVE. BUT LINGERING TROUGH WILL REMAIN PERSISTENT OVER GREAT
LAKES THROUGH THE WEEKEND...ALLOWING A STEADY STREAM OF COOLER AIR
TO FILTER IN KEEPING TEMPS BELOW NORMAL. PLENTY OF CLOUDS AS BEST
CHANCE FOR SCT SHOWERS THROUGH THE WEEKEND WILL CONTINUE TO BE
ACROSS THE NW /CLOSEST TO THE TROUGH/...BUT MODELS PROJECTING A
COMPACT BUT POTENT SHORTWAVE LATER SAT INTO SUN WHICH COULD BRING
MORE WIDESPREAD LIGHT SHOWERS TO REMAINDER OF CENTRAL PA DURING
THAT TIME.
ONCE THAT SLIDES THROUGH...PATTERN DOES BECOME SOMEWHAT MORE
PROGRESSIVE. MEANING THAT BROAD RIDGE OVER CENTRAL U.S. WILL
GRADUALLY WORK ITS WAY EASTWARD BRINGING A PERIOD OF MORE SETTLED
WEATHER FOR MON-WED WITH TEMPERATURES GRADUALLY MODIFYING BACK TO
SEASONAL NORMALS. NEXT MIDWEEK COULD AGAIN BRING UNSETTLED
WEATHER.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
MOIST SERLY FLOW INTO THE REGION TO THE NORTH OF A WARM FRONT
OVER THE CAROLINAS/VA AND A COLD FRONT IN THE OHIO VALLEY WILL
PERSIST AT LEAST THROUGH THE EVENING HOURS. THIS WILL MAINTAIN
POOR FLYING CONDS ACROSS ALL OF CENTRAL PA WITH IFR CIGS AND ON
AND OFF OR HEAVIER SHOWERS.
COLD FRONT IS FORECAST TO MOVE THROUGH WEST TO EAST OVERNIGHT
TURNING SFC WINDS TO THE SW AND BRINGING WIDESPREAD PCPN TO AN
END.
.OUTLOOK...
.THU...IMPROVING CONDS AFTER AM LOW CIGS/RAIN.
.FRI...NO SIG WX EXPECTED.
.SAT-SUN...SCT SHRA POSS W/ CFROPA.
&&
.HYDROLOGY...
NO CHANGES TO THE FLOOD WATCH TAKING INTO ACCOUNT RADAR TRENDS
AND LATEST MODELS CONTINUING TO DEPICT THE HEAVIEST RAINS OVER THE
WATCH AREA. OBSERVED RAINFALL AMOUNTS OF 2 TO 3 INCHES SO FAR
ACROSS LOWER SUSQUEHANNA VALLEY. SOME CONCERN FOR LOCALIZED FLASH
FLOODING WITH EMBEDDED TSTMS LKLY FOLLOWING PERSISTENT OVERRUNNING
WITH CONVECTIVE ENHANCEMENT. THE RISK FOR EXCESSIVE RAINFALL IS
CERTAINLY ELEVATED WITH AT LEAST SOME MINOR FLOODING LKLY TO
OCCUR. THE PATTERN IS VERY FAVORABLE WITH RELATIVELY HIGH
CONFIDENCE IN HEAVY TO POTENTIALLY EXCESSIVE/LOCALIZED AMOUNTS.
CONCERNING FCST POINTS...THE LOWER MAIN STEM SUSQ TRIBS AND
JUNIATA BASIN POINTS ARE MOST LKLY TO EXCEED FLOOD STAGES...AND
DAYSHIFT WILL NEED TO CONSIDER ISSUING FLW`S. THE CRESTS WILL BE
TIED TO QPF WITH PREVIOUS BASE FLOWS AVERAGING NEAR NORMAL FOR
LATE APRIL.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH THURSDAY MORNING FOR PAZ026>028-035-036-
049>053-056>059-063>066.
&&
$$
SYNOPSIS...GARTNER/STEINBUGL
NEAR TERM...GARTNER
SHORT TERM...GARTNER/STEINBUGL
LONG TERM...RXR
AVIATION...GARTNER
HYDROLOGY...GARTNER/ROSS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
203 PM EDT WED APR 30 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE TO THE CAROLINA COAST THURSDAY MORNING WITH
DRY HIGH PRESSURE BUILDING IN FROM THE WEST. EXPECT SOMEWHAT COOL
WEATHER LATE THIS WEEK...THEN WARMER GOING INTO EARLY NEXT WEEK AS
AN UPPER RIDGE BUILDS OVER OUR REGION.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 145 PM EDT...THE BEST CIRRUS SHIELD THAT HAS BEEN KEEPING
UPSTREAM AREAS QUITE STABLE HAS STARTED TO SLIP SLIGHTLY EAST...BUT
WE ARE STILL SEEING LITTLE TO NO CONVECTIVE DEVELOPMENT OF ANY
CONSEQUENCE BACK OVER WRN GA. THE LATEST HRRR AND LOCAL WORKSTATION
WRF MODEL RUNS DO HAVE THE LINE JUST AHEAD OF THE APPROACHING COLD
FRONT FILLING IN SLIGHTLY THROUGH THE LATE AFTERNOON AND EVENING
HOURS. HOWEVER...EVEN IF HEAVY SHOWERS MOVE OVER A BASIN AT THIS
POINT...IT WOULD STILL TAKE MULTIPLE CELLS OVER ANY STREAM BASIN TO
PRODUCE FLASH FLOODING...AND THAT DOES NOT APPEAR LIKELY AT THIS
POINT. THE FLASH FLOOD WATCH MAY BE CANCELLED WITHIN THE HOUR UNLESS
WE START SEEING VIGOUROUS REDEVELOPMENT ALONG THE FRONTAL BAND TO
THE WEST.
OTHERWISE...THE RETREATING WARM FRONT APPEARS TO BE DRAPED ALONG THE
INTERSTATE 40 CORRIDOR THIS AFTN AND PERHAPS DRIFTING A BIT
NORTHWARD OR GRADUALLY DISSIPATING. ALOFT...THE H5 LOW CENTER WILL
WOBBLE FROM THE MIDWEST LATE TODAY TO THE SRN SHORES OF THE GREAT
LAKES OVERNIGHT...WITH THE ASSOCIATED SURFACE COLD FRONT GRADUALLY
PUSHING EASTWARD THROUGH THE REGION. COVERAGE OF SHRA/TSRA WITH THE
FRONTAL BAND IS NOW EXPECTED TO BE SCATTERED AT BEST. THE STRONGEST
DEEP LAYER SHEAR WILL LIKELY TRANSIT EASTWARD OVER THE PIEDMONT THIS
EVENING...AND LOCATIONS EAST OF INTERSTATE 77 WILL STAND THE BEST
CHANCE OF ANY LINGERING SVR THREAT. THIS APPEARS A BIT LESS THAN
EARLIER AS WELL. COLD ADVECTION AND DRYING WILL ONSET FROM THE WEST
DURING THE OVERNIGHT HOURS...EVEN IF THE SFC FRONT IS DELAYED IN
LINE WITH THE OPERATIONAL NAM. LINGERING WESTERLY UPSLOPE SHOWERS
COULD IMPACT THE NRN MTNS THROUGH THU MORNING BUT SHOULD DRY UP
THROUGH THU AFTN. EXPECT TEMPS TO COOL SLOWLY OVERNIGHT WITH MINS UP
TO TWO CATEGORIES ABOVE NORMAL. MAXES WILL BE AROUND OR BELOW NORMAL
THU AFTN.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 130 PM WEDNESDAY...THE SHORT TERM LOOKS QUIET...AS THE COLD
FRONT SAGS SOUTH OF THE AREA TO THE GULF COAST AND ALONG THE
CAROLINA COASTS. DRY WLY/NWLY CAA FLOW AT 850 MB WILL PERSIST
THURSDAY NIGHT THRU SATURDAY. THERE WILL BE A PERSISTENT 250 MB JET
STREAK FROM THE CENTRAL GULF STATES TO NEW ENGLAND...WHICH WILL
CARRY PERIODS OF THICKER MID-HIGH CLOUDS...ESP ACRS THE SRN HALF OF
THE CWFA. THIS IN COMBINATION WITH CAA...WILL KEEP TEMPS BELOW
NORMAL ON FRIDAY. AS THE JET SHIFTS A BIT TO THE EAST...LESS CLOUD
COVER IS EXPECTED FOR SATURDAY WITH WARMER TEMPS. OVERNIGHT LOWS
BOTH THURSDAY AND FRIDAY NIGHTS WILL BE SLIGHTLY BELOW NORMAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 150 PM EDT WEDNESDAY...THE MEDIUM RANGE PERIOD INITIALIZES
SATURDAY EVENING AS A WEAK UPPER WAVE MOVES OFF THE CAROLINA COAST.
WEAK SURFACE HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER OVER
THE SOUTHERN STATES WITH AN UPPER LEVEL RIDGE AXIS FROM TEXAS TO THE
DAKOTAS ON SUNDAY SLIDING SLOWLY EAST INTO THE FIRST OF NEXT WEEK.
A STALLED OUT FRONT FROM THE MID MISSISSIPPI VALLEY TO NC WILL HAVE
WEAK IMPULSES RIDING IN FROM THE NW TOWARD OUR AREA INTO EARLY NEXT
WEEK. THE MORE SIGNIFICANT IMPULSE CROSSING LATE MONDAY AND AGREED
ON BY BOTH GFS AND ECMWF. ONLY ONE OF OUR NEIGHBORS SO FAR AGREE ON
RAISING POPS TO SLIGHT FOR THIS PERIOD. AS THIS AREA OF SLIGHTLY
DISTURBED WEATHER MOVES OFF THE MID ATLANTIC COAST MONDAY NIGHT AND
TUESDAY...THE UPPER RIDGE WILL COME IN FROM THE WEST. THE AXIS OF
THE RIDGE IS FORECAST TO EXTEND FROM THE EASTERN GULF TO WISCONSIN
AT 12Z WEDNESDAY. TEMPERATURES WILL BE A FEW DEGREES ABOVE NORMAL ON
SUNDAY AND THEN WELL ABOVE NORMAL BY MID WEEK UNDER THE DOME OF THE
UPPER RIDGE. BASICALLY DRY THROUGH THE PERIOD WITH ONLY THIS SLIGHT
CHANCE POPS IN NC NRN FOOTHILLS AND PIEDMONT.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...THE EARLY BAND OF RAIN SHOWERS HAS MOVED EAST OF THE
TERMINAL VICINITY...AND THE ACTIVITY BACK TO THE WEST ALONG THE
APPROACHING COLD FRONT HAS BEEN RATHER TAME THUS FAR. THERE IS THUS
LOW CONFIDENCE ABOUT TSRA REACHING THE AIRFIELD...SO TSRA WILL BE
PULLED IN FAVOR OF TEMPO SHRA FOR THE EVENING HOURS. KCLT SHOULD
REMAIN SOLIDLY IN THE WARM SECTOR S OF THE LIFTING/DISSIPATING WEDGE
BOUNDARY. S TO SW WINDS EARLY WILL SLOWLY VEER THROUGH THE PERIOD
AND THEN WEAKEN OVERNIGHT. THIS MAY ALLOW CIGS TO TRANSITION BACK
DOWN THROUGH MVFR TO IFR BY 09Z. EXPECT FAIRLY RAPID RECOVERY
THROUGH THU MORNING IN THE SW TO WSW FLOW.
ELSEWHERE...KHKY REMAINS THE MAIN TROUBLE SPOT ACROSS THE FOOTHILLS
AS THE WEDGE BOUNDARY HAS PRODUCED LINGERING IFR TO LIFR CONDITIONS.
STILL EXPECT LATE AFTN IMPROVEMENT BUT IT WILL CONTINUE TO BE SLOW.
WILL CAP IMPROVEMENT AT KHKY TO MVFR BY EVENING. ELSEWHERE...VFR
CONDITIONS CONTINUE...WITH MAINLY MID AND HIGH LEVEL CIGS. TSRA
CONFIDENCE IS NOW MUCH LESS...AND WILL FEATURE MAINLY VCSH AND VCTS
THROUGH THE EVENING HOURS WITH FROPA. EXPECT A RETURN TO IFR
CONDITIONS DURING THE OVERNIGHT HOURS AT THE FOOTHILL SITES AS SW
WINDS SLACKEN AND BOUNDARY LAYER MOISTURE REMAINS UNDER DRYING
ALOFT. THESE CONDITIONS SHOULD IMPROVE QUICKLY THU MORNING...EXCEPT
PERSIST THROUGH MID MORNING AT KHKY. EXPECT MAINLY WSW FLOW LATE IN
THE PERIOD...EXCEPT NW AT KAVL.
OUTLOOK...DRYING CONDITIONS WITH NO RESTRICTIONS EXPECTED THU AFTN
THROUGH MONDAY.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 90% MED 74% HIGH 80% HIGH 88%
KGSP MED 72% MED 73% MED 74% HIGH 89%
KAVL HIGH 84% HIGH 85% HIGH 95% HIGH 97%
KHKY MED 61% MED 66% MED 71% MED 77%
KGMU HIGH 89% HIGH 86% HIGH 92% HIGH 97%
KAND HIGH 91% HIGH 94% MED 78% 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...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR GAZ010-017-
018-026-028-029.
NC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ033-
035>037-048>053-056>059-062>065-068>072-082-501>510.
SC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR SCZ001>014-
019.
&&
$$
SYNOPSIS...DEO
NEAR TERM...HG
SHORT TERM...ARK
LONG TERM...DEO
AVIATION...HG
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
115 PM EDT WED APR 30 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT SLOWLY NORTH OF THE AREA BY EARLY OR MID
AFTERNOON. A LARGE AND COMPLEX STORM SYSTEM LOCATED OVER THE
CENTRAL UNITED STATES WILL MOVE SLOWLY EAST PUSHING A TRAILING
COLD FRONT ACROSS THE REGION TONIGHT. MOISTURE WILL INTERACT WITH
THIS FRONT TO BRING BANDS OF SHOWERS AND THUNDERSTORMS...SOME WITH
VERY HEAVY RAIN AND A SLIGHT RISK OF SEVERE WEATHER.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1228 PM EDT WEDNESDAY...
EARLY AFTERNOON UPDATE REFLECTS SCATTERED THUNDERSTORMS TRACKING
OVER THE PIEDMONT OF VA. THE REST OF THE AREA IS IN A LULL AND
THEREFORE LOWERED POPS THROUGH THE EARLY PART OF THE
AFTERNOON. THE 12Z RAP SEEMS TO HAVE A HANDLE ON THIS MORNINGS
STORMS...THEREFORE PLACED MORE WEIGHT IN THE RAP FOR THE
AFTERNOON/EVENING FORECAST.
WILL CONTINUE TO KEEP AN EYE ON THE WEDGE AS IT ERODES.
INSTABILITIES ACROSS SOUTHSIDE ARE SLOWLY INCREASING THROUGH NOON
TODAY. THIS INSTABILITY WILL EVENTUALLY REPLACE THE WEDGE. AS THE
FRONT APPROACHES THE REGION...STRONGER STORMS WILL SKIRT ACROSS
THE AREA. SPC HAS SHRUNK THE SLIGHT RISK AREA TO EAST OF HWY 29.
WE WILL CONTINUE TO MONITOR THE SITUATION AS IT UNFOLDS.
AS OF 300 AM EDT WEDNESDAY...
SHOWERS REMAIN RATHER SCATTERED AND DISORGANIZED ACROSS THE
SOUTH/EAST EARLY THIS MORNING WITH DEVELOPMENT OCCURRING ALONG
THE LINGERING FRONT AND STRONG THETA-E GRADIENT OVER NC PER MSAS.
STRONG WEDGE REMAINS SLOW TO BEGIN LIFTING NORTH BUT STARTING TO
SEE SOME PRESSURE FALLS WITHIN THE COLD POOL WHICH SHOULD ALLOW
EROSION OF THE CAD FROM SOUTH TO NORTH INTO EARLY THIS AFTERNOON.
HOWEVER MAY TAKE LONGER TO SCOUR THINGS OUT FROM ROA-LYH AND
POINTS NORTH ESPCLY IF ADDED SHRA MOVES THROUGH EARLY ON.
OTRW LARGE MCS FEATURE ALONG THE GULF COAST HAS BASICALLY
INTERRUPTED THE NORTHWARD FLUX OF DEEPER MOISTURE AHEAD OF THE
FRONT ATTM WITH A VOID IN SHRA LIKELY TO LINGER OVER THE WEST
WHERE THE WEDGE IS DEEPER. FRONT FINALLY SHIFTS EAST THIS
AFTERNOON WITH PERHAPS A BAND OF CONVECTION ALONG THE WESTERN
SLOPES EARLY AFTERNOON BEFORE LIFT JUMPS OUT TO ALONG AND EAST
OF THE BLUE RIDGE TOWARD MID/LATE AFTERNOON WHERE MODELS SEEM TO
FOCUS BEST CONVERGENCE PER WEAK INSTABILITY. THIS SHOULD RESULT IN
SOME BANDS OF SLOW MOVING CONVECTION ESPCLY EASTERN HALF WHERE
BETTER SEVERE AND HEAVY RAIN THREAT LOOKS TO DEVELOP PENDING
DEGREE OF WEAK CAPE THAT CAN BE REALIZED GIVEN STRONG SHEAR ALOFT.
THUS HAVE ADJUSTED POPS DOWN SOME ESPCLY WEST THIS MORNING AND
THEN STAGGERED DEEPER CONVECTION IN BANDS FROM WEST TO EAST THIS
AFTERNOON UNDER CAT POPS. THIS WILL CAUSE A REDUCTION IN AVERAGE
QPF WESTERN HALF WITH HEAVIEST OVER THE EAST/NE SIMILAR TO THE
LATEST WPC DAY1 OUTLOOK. HIGH TEMPS REMAIN TRICKY WITH GUIDANCE
SUGGESTING CAD EROSION MAY BE SLOWER WHILE ONCE THE FLOW TURNS
SOUTHERLY THEN READINGS COULD ZOOM. FOR NOW TWEAKED DOWN IN THE
CENTRAL AND NE BUT EXPECTING MOST TO GET INTO THE 60S WITH 70S
SOUTHSIDE AND IN MUCH OF THE EAST.
CONVECTION WILL PUSH SLOWLY EAST THIS EVENING BUT MAY STILL HAVE
SOME STORMS AROUND OUT EAST THROUGH ABOUT MIDNIGHT OR SO AS THE
SURFACE BOUNDARY REMAINS SLOW UNDER THE SW FLOW ALOFT. WILL
CONTINUE HIGH POPS FOR A FEW HOURS AFTER SUNSET...THEN LOWER TO
CHANCE/SLIGHT POPS FOR LINGERING SHRA AFTER MIDNIGHT WITH WEAK LOW
LEVEL WESTERLY FLOW KICKING IN OVER THE WEST BEHIND THE BOUNDARY
OVERNIGHT. MAY GET ENOUGH COOLING DESPITE CLOUDS TO REACH THE
UPPER 40S FAR WEST...WITH LOW/MID 50S BLUE RIDGE BUT ONLY 60ISH
SE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM EDT WEDNESDAY...
THE UPPER LEVEL SLOWLY SLIDES EAST DURING THE PERIOD. COLD FRONT
MOVES EAST ON THURSDAY AND REACHES THE COAST THURSDAY NIGHT. THE
GFS AND ECMWF SHOWED THE FRONTAL BOUNDARY STALLING JUST OFFSHORE
FRIDAY. THE ECMWF DEVELOPS A WAVE ALONG THE BOUNDARY AND GENERATES
SOME SHOWERS ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA FRIDAY
AFTERNOON INTO FRIDAY NIGHT. BELIEVE THIS IS OVERDONE AND EXPECT
ANY CONVECTION TO FURTHER SOUTH.
SHAPED POPS TOWARDS THE GFS FOR THE RESIDUAL SHOWERS ON THURSDAY
AND FRIDAY. SOUTHWESTERLY FLOW ON THURSDAY WILL ALLOW AFTERNOON
HIGHS WARM INTO THE UPPER 50S IN THE NORTHWEST MOUNTAINS TO THE
MID 70S ACROSS THE SOUTHEAST. LOWS THURSDAY NIGHT WILL DROP INTO
THE UPPER 30S IN THE MOUNTAINS TO AROUND 50 IN THE PIEDMONT. THE
WEST TO NORTHWEST FLOW ON FRIDAY WILL RESULT IN COOLER AIR WITH
HIGHS HIGHS FROM THE UPPER 50S IN THE MOUNTAINS TO THE LOWER 70S
IN THE PIEDMONT. WENT WITH LOWS FRIDAY NIGHT CLOSE TO THE ENSEMBLE
MOS WITH VALUES FROM THE UPPER 30S IN THE WEST TO THE MID 40S IN
THE EAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 100 PM EDT TUESDAY...
MODELS IN GENERALLY GOOD AGREEMENT THROUGH THE EXTENDED PERIOD AS
THE ERN TROF SLIDES EAST AND ALLOWS RIDGING WITH NW FLOW TO
BECOME ESTABLISHED OVER OUR AREA. PREVIOUS MODEL RUNS INDICATING A
SIGNIFICANT COLD PUNCH FOR THE WEEKEND HAVE MELLOWED AND WILL
TREND THE CURRENT FORECAST GRIDS WARMER TOWARD THE HPC GUIDANCE.
BEST ENERGY WITH UPPER SHORT WAVE ROTATING AROUND THE BASE OF THE
ERN UPPER TROF SATURDAY IS SOUTH OF THE FA AND MOISTURE IS MORE
LIMITED. THIS WILL HELP SUPPRESS SHOWER ACTIVITY ON SATURDAY AS A
WEAK SFC BOUNDARY PUSHES THROUGH SO WILL BE MUCH LESS AGGRESSIVE
WITH POPS. THERE IS NO BIG PUSH TO THIS BOUNDARY AND IT WILL
REMAIN IN THE NEIGHBORHOOD FOR THE REMAINDER OF THE FORECAST
PERIOD. THERE ARE INDICATIONS OF IMPULSES RIDING ALONG THE FRONT
BUT SUBTLE DIFFERENCES IN PLACEMENT OF FEATURES WILL MAKE A BIG
DIFFERENCE IN SENSIBLE WEATHER. WILL OPT TO CONFINE POPS TO THE
TUESDAY PERIOD AS THE BOUNDARY GETS ENOUGH PUSH TO MOVE THROUGH
AS A WARM FRONT.
&&
.AVIATION /18Z WEDNESDAY THROUGH SUNDAY/...
AS OF 115 PM EDT WEDNESDAY...
EXTREMELY POOR FLYING CONDITIONS EXPECTED TO PREVAIL THIS
AFTERNOON WITH WEDGE IN PLACE SUPPORTING CONTINUATION OF LOW
STRATUS CIGS AND VSBYS IN FOG. EXPECT WIDESPREAD MVFR TO IFR UNTIL
THE WEDGE FRONT STARTS TO MOVE NORTH LATER THIS AFTERNOON.
THROUGH THE AFTERNOON INT0 THE EVENING...WILL SEE MOST HEADING
TOWARD SHOWERS AND STORMS WITH WINDS SHIFTING TOWARD THE SOUTHEAST
TO SOUTHWEST AND THE WEDGE BREAKING. COLD FRONTAL BOUNDARY WILL
NOT REACH BLF/LWB AT LEAST UNTIL THIS EVENING. THINGS SHOULD DRY
OUT TOWARD LATE THIS AFTERNOON IN THE WEST BUT LOW CONFIDENCE IN
JUST HOW FAST SHOWERS WILL SHIFT EAST. THUS LEFT IN A MORE
PESSIMISTIC SCENARIO IN REGARDS TO EXITING LOWER CIGS AND SHOWERS
WHILE INCLUDING A PERIOD OF VCTS OR PREVAILING TSRA DURING THE
AFTERNOON ESPCLY OUTSIDE THE WEDGE. APPEARS AXIS OF HEAVIER
SHOWERS AND STORMS MAY REDEVELOP EAST OF THE BLUE RIDGE...MORESO
IN THE PIEDMONT (LYH/DAN) THIS AFTERNOON PROVIDED HEATING SO
INCLUDING MORE PREVAILING TSRA THERE.
WINDS WILL ALSO PICK UP FROM THE SOUTH AND SE BY THIS EVENING AS
WARMER AIR ARRIVES PROVIDING FOR GUSTS TO 25-30 KTS AHEAD OF THE
FRONT.
AXIS OF SHOWERS AND STORMS SHOULD FINALLY EXIT THE EAST AFTER
MIDNIGHT BUT DRY ADVECTION BEHIND THE BOUNDARY LOOKS QUITE WEAK.
GUIDANCE SUGGESTS THAT IFR/LIFR CIGS AND VSBYS IN FOG/STRATUS
COULD REDEVELOP ACROSS THE REGION. FOR NOW DID NOT GO THAT LOW BUT
BROUGHT BACK MVFR TO OCNL IFR CIGS LATE TONIGHT.
APPEARS ENOUGH DRYING ALOFT TO PERHAPS SEE IMPROVEMENT TO VFR
ACROSS THE EAST LATER THURSDAY INTO FRIDAY WITH MVFR LIKELY
LINGERING AT TIMES ACROSS THE SE WEST VA LOCATIONS INTO FRIDAY. AN
UPPER LEVEL TROUGH OF LOW PRESSURE WILL CROSS THE TENNESSEE
VALLEY ON SATURDAY FOLLOWED BY WEAK HIGH PRESSURE INTO SUNDAY.
HOWEVER WESTERLY FLOW MAY STILL INDUCE SOME UPSLOPE MVFR CIGS AND
PERHAPS ISOLATED -SHRA ACROSS THE SE WEST VA SITES DURING
SATURDAY.
&&
.HYDROLOGY...
AS OF 340 AM EDT WEDNESDAY...
NO CHANGES TO THE RIVER FORECASTS...STILL EXPECTING ENOUGH QPF TO
BRING PORTIONS OF THE LOWER ROANOKE AND DAN TO GO INTO MODERATE
FLOOD IN NEXT DAY OR TWO. HOWEVER...RAINFALL IS LIMITED TO
SCATTERED CLUSTERS OF SHRA/TSRA EARLY THIS MORNING AND WILL HAVE
TO BECOME MORE ORGANIZED AS THE WARM FRONT LIFTS NORTH LATER THIS
MORNING FOLLOWED BY THE COLD FRONT THIS AFTERNOON AND EVENING.
STILL MAINLY CONCERNED WITH THE FLASH FLOOD THREAT ESPCLY ALONG
AND EAST OF THE BLUE RIDGE WHERE THE HEAVY RAIN POTENTIAL LOOKS
BEST.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ007-
009>020-022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ001>006-
018>020.
WV...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR WVZ042>045.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...JH/RCS
SHORT TERM...KK
LONG TERM...KK/MBS
AVIATION...AMS/JH/WP
HYDROLOGY...AMS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1230 PM EDT WED APR 30 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT SLOWLY NORTH OF THE AREA BY EARLY OR MID
AFTERNOON. A LARGE AND COMPLEX STORM SYSTEM LOCATED OVER THE
CENTRAL UNITED STATES WILL MOVE SLOWLY EAST PUSHING A TRAILING
COLD FRONT ACROSS THE REGION TONIGHT. MOISTURE WILL INTERACT WITH
THIS FRONT TO BRING BANDS OF SHOWERS AND THUNDERSTORMS...SOME WITH
VERY HEAVY RAIN AND A SLIGHT RISK OF SEVERE WEATHER.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1228 PM EDT WEDNESDAY...
EARLY AFTERNOON UPDATE REFLECTS SCATTERED THUNDERSTORMS TRACKING
OVER THE PIEDMONT OF VA. THE REST OF THE AREA IS IN A LULL AND
THEREFORE LOWERED POPS THROUGH THE EARLY PART OF THE
AFTERNOON. THE 12Z RAP SEEMS TO HAVE A HANDLE ON THIS MORNINGS
STORMS...THEREFORE PLACED MORE WEIGHT IN THE RAP FOR THE
AFTERNOON/EVENING FORECAST.
WILL CONTINUE TO KEEP AN EYE ON THE WEDGE AS IT ERODES.
INSTABILITIES ACROSS SOUTHSIDE ARE SLOWLY INCREASING THROUGH NOON
TODAY. THIS INSTABILITY WILL EVENTUALLY REPLACE THE WEDGE. AS THE
FRONT APPROACHES THE REGION...STRONGER STORMS WILL SKIRT ACROSS
THE AREA. SPC HAS SHRUNK THE SLIGHT RISK AREA TO EAST OF HWY 29.
WE WILL CONTINUE TO MONITOR THE SITUATION AS IT UNFOLDS.
AS OF 300 AM EDT WEDNESDAY...
SHOWERS REMAIN RATHER SCATTERED AND DISORGANIZED ACROSS THE
SOUTH/EAST EARLY THIS MORNING WITH DEVELOPMENT OCCURRING ALONG
THE LINGERING FRONT AND STRONG THETA-E GRADIENT OVER NC PER MSAS.
STRONG WEDGE REMAINS SLOW TO BEGIN LIFTING NORTH BUT STARTING TO
SEE SOME PRESSURE FALLS WITHIN THE COLD POOL WHICH SHOULD ALLOW
EROSION OF THE CAD FROM SOUTH TO NORTH INTO EARLY THIS AFTERNOON.
HOWEVER MAY TAKE LONGER TO SCOUR THINGS OUT FROM ROA-LYH AND
POINTS NORTH ESPCLY IF ADDED SHRA MOVES THROUGH EARLY ON.
OTRW LARGE MCS FEATURE ALONG THE GULF COAST HAS BASICALLY
INTERRUPTED THE NORTHWARD FLUX OF DEEPER MOISTURE AHEAD OF THE
FRONT ATTM WITH A VOID IN SHRA LIKELY TO LINGER OVER THE WEST
WHERE THE WEDGE IS DEEPER. FRONT FINALLY SHIFTS EAST THIS
AFTERNOON WITH PERHAPS A BAND OF CONVECTION ALONG THE WESTERN
SLOPES EARLY AFTERNOON BEFORE LIFT JUMPS OUT TO ALONG AND EAST
OF THE BLUE RIDGE TOWARD MID/LATE AFTERNOON WHERE MODELS SEEM TO
FOCUS BEST CONVERGENCE PER WEAK INSTABILITY. THIS SHOULD RESULT IN
SOME BANDS OF SLOW MOVING CONVECTION ESPCLY EASTERN HALF WHERE
BETTER SEVERE AND HEAVY RAIN THREAT LOOKS TO DEVELOP PENDING
DEGREE OF WEAK CAPE THAT CAN BE REALIZED GIVEN STRONG SHEAR ALOFT.
THUS HAVE ADJUSTED POPS DOWN SOME ESPCLY WEST THIS MORNING AND
THEN STAGGERED DEEPER CONVECTION IN BANDS FROM WEST TO EAST THIS
AFTERNOON UNDER CAT POPS. THIS WILL CAUSE A REDUCTION IN AVERAGE
QPF WESTERN HALF WITH HEAVIEST OVER THE EAST/NE SIMILAR TO THE
LATEST WPC DAY1 OUTLOOK. HIGH TEMPS REMAIN TRICKY WITH GUIDANCE
SUGGESTING CAD EROSION MAY BE SLOWER WHILE ONCE THE FLOW TURNS
SOUTHERLY THEN READINGS COULD ZOOM. FOR NOW TWEAKED DOWN IN THE
CENTRAL AND NE BUT EXPECTING MOST TO GET INTO THE 60S WITH 70S
SOUTHSIDE AND IN MUCH OF THE EAST.
CONVECTION WILL PUSH SLOWLY EAST THIS EVENING BUT MAY STILL HAVE
SOME STORMS AROUND OUT EAST THROUGH ABOUT MIDNIGHT OR SO AS THE
SURFACE BOUNDARY REMAINS SLOW UNDER THE SW FLOW ALOFT. WILL
CONTINUE HIGH POPS FOR A FEW HOURS AFTER SUNSET...THEN LOWER TO
CHANCE/SLIGHT POPS FOR LINGERING SHRA AFTER MIDNIGHT WITH WEAK LOW
LEVEL WESTERLY FLOW KICKING IN OVER THE WEST BEHIND THE BOUNDARY
OVERNIGHT. MAY GET ENOUGH COOLING DESPITE CLOUDS TO REACH THE
UPPER 40S FAR WEST...WITH LOW/MID 50S BLUE RIDGE BUT ONLY 60ISH
SE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM EDT WEDNESDAY...
THE UPPER LEVEL SLOWLY SLIDES EAST DURING THE PERIOD. COLD FRONT
MOVES EAST ON THURSDAY AND REACHES THE COAST THURSDAY NIGHT. THE
GFS AND ECMWF SHOWED THE FRONTAL BOUNDARY STALLING JUST OFFSHORE
FRIDAY. THE ECMWF DEVELOPS A WAVE ALONG THE BOUNDARY AND GENERATES
SOME SHOWERS ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA FRIDAY
AFTERNOON INTO FRIDAY NIGHT. BELIEVE THIS IS OVERDONE AND EXPECT
ANY CONVECTION TO FURTHER SOUTH.
SHAPED POPS TOWARDS THE GFS FOR THE RESIDUAL SHOWERS ON THURSDAY
AND FRIDAY. SOUTHWESTERLY FLOW ON THURSDAY WILL ALLOW AFTERNOON
HIGHS WARM INTO THE UPPER 50S IN THE NORTHWEST MOUNTAINS TO THE
MID 70S ACROSS THE SOUTHEAST. LOWS THURSDAY NIGHT WILL DROP INTO
THE UPPER 30S IN THE MOUNTAINS TO AROUND 50 IN THE PIEDMONT. THE
WEST TO NORTHWEST FLOW ON FRIDAY WILL RESULT IN COOLER AIR WITH
HIGHS HIGHS FROM THE UPPER 50S IN THE MOUNTAINS TO THE LOWER 70S
IN THE PIEDMONT. WENT WITH LOWS FRIDAY NIGHT CLOSE TO THE ENSEMBLE
MOS WITH VALUES FROM THE UPPER 30S IN THE WEST TO THE MID 40S IN
THE EAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 100 PM EDT TUESDAY...
MODELS IN GENERALLY GOOD AGREEMENT THROUGH THE EXTENDED PERIOD AS
THE ERN TROF SLIDES EAST AND ALLOWS RIDGING WITH NW FLOW TO
BECOME ESTABLISHED OVER OUR AREA. PREVIOUS MODEL RUNS INDICATING A
SIGNIFICANT COLD PUNCH FOR THE WEEKEND HAVE MELLOWED AND WILL
TREND THE CURRENT FORECAST GRIDS WARMER TOWARD THE HPC GUIDANCE.
BEST ENERGY WITH UPPER SHORT WAVE ROTATING AROUND THE BASE OF THE
ERN UPPER TROF SATURDAY IS SOUTH OF THE FA AND MOISTURE IS MORE
LIMITED. THIS WILL HELP SUPPRESS SHOWER ACTIVITY ON SATURDAY AS A
WEAK SFC BOUNDARY PUSHES THROUGH SO WILL BE MUCH LESS AGGRESSIVE
WITH POPS. THERE IS NO BIG PUSH TO THIS BOUNDARY AND IT WILL
REMAIN IN THE NEIGHBORHOOD FOR THE REMAINDER OF THE FORECAST
PERIOD. THERE ARE INDICATIONS OF IMPULSES RIDING ALONG THE FRONT
BUT SUBTLE DIFFERENCES IN PLACEMENT OF FEATURES WILL MAKE A BIG
DIFFERENCE IN SENSIBLE WEATHER. WILL OPT TO CONFINE POPS TO THE
TUESDAY PERIOD AS THE BOUNDARY GETS ENOUGH PUSH TO MOVE THROUGH
AS A WARM FRONT.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
AS OF 650 AM EDT WEDNESDAY...
EXTREMELY POOR FLYING CONDITIONS EXPECTED TO PREVAIL THIS MORNING
WITH WEDGE IN PLACE SUPPORTING CONTINUATION OF LOW STRATUS CIGS
AND VSBYS IN FOG. EXPECT WIDESPREAD MVFR TO IFR UNTIL THE WEDGE
FRONT STARTS TO MOVE NORTH LATER THIS MORNING. SHOWERS AND STORMS
WILL ALSO MOVE EAST OF LYH/DAN IN THE NEXT HOUR OR TWO WITH ADDED
SHRA LIKELY AFFECTING THE EASTERN CORRIDOR BY MID MORNING.
DURING THE DAY WILL SEE MOST OF THE DAY HEADING TOWARD SHOWERS
AND STORMS WITH WINDS SHIFTING TOWARD THE SOUTHEAST TO SOUTHWEST
AND THE WEDGE BREAKING. COLD FRONTAL BOUNDARY WILL NOT REACH
BLF/LWB AT LEAST UNTIL THIS EVENING. THINGS SHOULD DRY OUT TOWARD
LATE THIS AFTERNOON IN THE WEST BUT LOW CONFIDENCE IN JUST HOW
FAST SHOWERS WILL SHIFT EAST. THUS LEFT IN A MORE PESSIMISTIC
SCENARIO IN REGARDS TO EXITING LOWER CIGS AND SHOWERS WHILE
INCLUDING A PERIOD OF VCTS OR PREVAILING TSRA DURING THE AFTERNOON
ESPCLY OUTSIDE THE WEDGE. APPEARS AXIS OF HEAVIER SHOWERS AND
STORMS MAY REDEVELOP ALONG AND EAST OF THE BLUE RIDGE THIS
AFTERNOON PROVIDED HEATING SO INCLUDING MORE PREVAILING TSRA
THERE.
WINDS WILL ALSO PICK UP FROM THE SOUTH AND SE BY AFTERNOON AS
WARMER AIR ARRIVES PROVIDING FOR GUSTS TO 25-30 KTS AHEAD OF THE
FRONT.
AXIS OF SHOWERS AND STORMS SHOULD FINALLY EXIT THE EAST AFTER
MIDNIGHT BUT DRY ADVECTION BEHIND THE BOUNDARY LOOKS QUITE WEAK.
GUIDANCE SUGGESTS THAT IFR/LIFR CIGS AND VSBYS IN FOG/STRATUS
COULD REDEVELOP ACROSS THE REGION. FOR NOW DID NOT GO THAT LOW BUT
BROUGHT BACK MVFR TO OCNL IFR CIGS LATE TONIGHT.
APPEARS ENOUGH DRYING ALOFT TO PERHAPS SEE IMPROVEMENT TO VFR
ACROSS THE EAST LATER THURSDAY INTO FRIDAY WITH MVFR LIKELY
LINGERING AT TIMES ACROSS THE SE WEST VA LOCATIONS INTO FRIDAY. AN
UPPER LEVEL TROUGH OF LOW PRESSURE WILL CROSS THE TENNESSEE
VALLEY ON SATURDAY FOLLOWED BY WEAK HIGH PRESSURE INTO SUNDAY.
HOWEVER WESTERLY FLOW MAY STILL INDUCE SOME UPSLOPE MVFR CIGS AND
PERHAPS ISOLATED -SHRA ACROSS THE SE WEST VA SITES DURING
SATURDAY.
&&
.HYDROLOGY...
AS OF 340 AM EDT WEDNESDAY...
NO CHANGES TO THE RIVER FORECASTS...STILL EXPECTING ENOUGH QPF TO
BRING PORTIONS OF THE LOWER ROANOKE AND DAN TO GO INTO MODERATE
FLOOD IN NEXT DAY OR TWO. HOWEVER...RAINFALL IS LIMITED TO
SCATTERED CLUSTERS OF SHRA/TSRA EARLY THIS MORNING AND WILL HAVE
TO BECOME MORE ORGANIZED AS THE WARM FRONT LIFTS NORTH LATER THIS
MORNING FOLLOWED BY THE COLD FRONT THIS AFTERNOON AND EVENING.
STILL MAINLY CONCERNED WITH THE FLASH FLOOD THREAT ESPCLY ALONG
AND EAST OF THE BLUE RIDGE WHERE THE HEAVY RAIN POTENTIAL LOOKS
BEST.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ007-
009>020-022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ001>006-
018>020.
WV...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR WVZ042>045.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...JH/RCS
SHORT TERM...KK
LONG TERM...KK/MBS
AVIATION...AMS/JH/WP
HYDROLOGY...AMS/JH