Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/02/14
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
905 PM MDT THU MAY 1 2014
.UPDATE...
ISSUED AT 905 PM MDT THU MAY 1 2014
NO BIG CHANGES TO THE FORECASTS THIS EVENING. DRY AIR IS IN PLACE
AS THE FLOW ALOFT BEGINS TRANSITIONING TO MORE NORTHWESTERLY.
EVENING RUNS OF THE RUC CONTINUE SHOWING SOME SHOWERS OVER THE
NORTHERN MOUNTAINS TOMORROW AFTERNOON...BUT KEEPS THE NORTHEAST
CORNER OF THE STATE DRY. REMOVED THE MENTION OF SHOWERS ON THE
PLAINS...BUT NO OTHER CHANGES TO THE FORECAST AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 224 PM MDT THU MAY 1 2014
WEAK CONVECTION ALREADY FADING A LITTLE...PROBABLY SOME
COMBINATION OF DRYING AND WARMING ALOFT. WINDS ALSO COMING DOWN A
LITTLE IN MANY PLACES...NOT SO MUCH ON THE EASTERN PART OF THE
PLAINS YET. WITH LIGHTER GRADIENTS THE WINDS SHOULD FALL OFF MORE
QUICKLY THAN USUAL IN THE LATE AFTERNOON/EARLY EVENING. JUST A FEW
HIGH CLOUDS EXPECTED OVERNIGHT AND WITH LIGHTER WINDS TEMPERATURES
WILL STILL BE COOL. EXPECT LOWS ON THE PLAINS TO BE ABOVE FREEZING
HOWEVER. JUST ENOUGH INSTABILITY FOR SOME CUMULUS AND MAYBE
ISOLATED VERY LIGHT SHOWERS OVER THE HIGH MOUNTAINS AND NORTHEAST
CORNER. STILL SOME WIND MIXING DOWN IN THE AFTERNOON...BUT LESS
THAN TODAY. CURRENT FORECAST OF 10-15 DEGREES WARMER LOOKS GOOD.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 224 PM MDT THU MAY 1 2014
LARGE SCALE UPPER AIR FLOW PATTERN REMAINED CONVOLUTED WITH A
SERIES OF HIGH AMPLITUDE LONG WAVE TROUGHS AND RIDGES EXTENDING
FROM EASTERN ASIA TO NORTH AMERICA. THIS HIGH WAVE/TROUGH
FREQUENCY PATTERN MAIN REASON FOR THE SLUGGISH PROGRESSION OF
STORM SYSTEMS ACROSS THE U.S. THE PAST SEVERAL DAYS. DO NOT SEE
MUCH OF A CHANGE IN THIS PATTERN OVER THE NEXT SEVERAL DAYS. ONE
OF THESE HIGH AMPLITUDE UPPER RIDGES NOW OVER THE WEST COAST WILL
SLOWLY MAKE ITS WAY EAST ACROSS THE CENTRAL ROCKY MTN REGION
DURING THE SATURDAY- TUESDAY TIME PERIOD. PRIOR TO ITS ARRIVAL...A
WEAK UPPER AIR DISTURBANCE IS FORECAST TO SLIDE DOWN THE FRONT
SIDE OF THIS RIDGE AND BRUSH NERN COLORADO LATE ON FRIDAY. WHILE
THE BOUNDARY LAYER LOOKS QUITE DRY...ADEQUATE MID-LEVEL
MOISTURE...LIFT AND INSTABILITY SHOULD BE ADEQUATE TO GENERATE AT
LEAST ISOLATED HIGH BASED SHOWERS/T-STORMS OVER THE NRN FRONT
RANGE AND FAR NORTHEAST PLAINS DURING THE LATE AFTERNOON AND EARLY
EVENING HOURS ON FRIDAY. CHANCES ARE THEY/LL PRODUCE MORE WIND
THAN WETTING RAINFALL WITH THE DRY SUB- CLOUD ENVIRONMENT.
OVERNIGHT SKIES WILL CLEAR AS DRIER...WARMER AIR ARRIVES WITH THE
UPPER RIDGE.
SATURDAY THROUGH MONDAY...TEMPERATURES RISE WITH THE PASSING RIDGE
WHICH MODELS SHOW REAMPLIFYING ALONG THE WAY. THAT SHOULD HAVE
LITTLE EFFECT ON TEMPERATURES OTHER THAN TO PRODUCE A MORE ZONAL
FLOW WHICH WILL ONLY FURTHER WARM TEMPERATURES WELL ABOVE THE
SEASONAL AVERAGE FOR THIS TIME OF YEAR. AVERAGE HIGH FOR DENVER IS
AROUND 66 DEGS. HIGHS EXPECTED SATURDAY-MONDAY AS MUCH AS 10 TO 15
DEGS ABOVE AVERAGE WITH SUNDAY BEING THE WARMEST OF THE THREE.
TUESDAY-THURSDAY...WARM UPPER RIDGE MOVES EAST WHICH ALLOWS THE
UPPER TROUGH OVER THE PACIFIC NORTHWEST COAST TO SLOWLY DROP IN OVER
THE GREAT BASIN ON TUESDAY AND PASS OVER COLORADO WEDNESDAY AND
THURSDAY GIVING THE FORECAST AREA ITS NEXT CHANCE OF WET AND
POSSIBLY STORMY WEATHER. TEMPERATURES SHOULD ALSO RETURN TO NEAR
AVERAGE DURING THIS PERIOD.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z FRIDAY LATE AFTERNOON)
ISSUED AT 224 PM MDT THU MAY 1 2014
VFR THROUGH FRIDAY. NORTH WINDS WILL DIMINISH IN THE LATE
AFTERNOON AND EVENING...AND TURN TO S/W DRAINAGE WINDS THIS
EVENING. NORTHWEST WINDS WILL MIX DOWN AGAIN STARTING ABOUT 18Z
FRIDAY...BUT WILL BE LIGHTER THAN TODAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DANKERS
SHORT TERM...GIMMESTAD
LONG TERM...BAKER
AVIATION...GIMMESTAD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1023 PM EDT THU MAY 1 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE OVER THE REGION OVERNIGHT ALLOWING FOR
SCATTERED SHOWERS AND A ISOLATED THUNDERSTORM THIS EVENING.
OTHERWISE DRY WEATHER FOR THE OVERNIGHT PERIOD WITH ANOTHER ROUND
OF SCATTERED SHOWERS ON FRIDAY. A WEAK DISTURBANCE WILL BRING A
CHANCE OF SHOWERS SATURDAY. A STRONGER DISTURBANCE SUNDAY MAY
PRODUCE ISOLATED THUNDERSTORMS WITH HAIL. DRIER AND SEASONABLE
WEATHER FOLLOWS FOR MOST OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
1030 PM UPDATE...
BUSY PAST THREE HOURS.
DESTABILIZATION ACROSS WESTERN AND CENTRAL PORTIONS OF NEW ENGLAND
PROVIDED THE FUEL TO FOR A LINE OF STORMS TO DEVELOP ALONG AND
AHEAD OF THE COLD FRONT SWEEPING OUR REGION THIS EVENING. MUCH OF
THAT LINE HAS FIZZLE TO THE EAST UPON ENCOUNTERMENT OF COOLER MORE
STABLE AIR ALONG THE E-SHORE. OF ALL THE MODEL SOLUTIONS...THE
WRF-ARW HANDLED THE SITUATION THE BEST.
MEANWHILE TO THE SOUTH AND EAST...PATCHY DENSE FOG HAS EXPANDED
IN AREAL COVERAGE WITH VISIBILITIES DOWN TO A QUARTER OF A MILE.
HIGH DEWPOINT AIR OVER THE COLDER WATERS CREATES QUITE THE SOUP.
EXPANDED THE DENSE FOG ADVISORY IN ACCORDANCE. FOG SHOULD LAST
INTO THE LATE EVENING HOURS JUST PRIOR TO COLD FRONTAL PASSAGE.
SOME TIMING TWEAKS MAY BE NECESSARY AS FOG IS LIKELY TO LAST
LONGER OVER THE ISLANDS THAN SE MA. SIGNIFICANT REDUCTION IS
VISIBILITIES WILL LEAD TO HAZARDOUS DRIVING CONDITIONS. HRRR MODEL
DOING A PRETTY GOOD JOB IN MODELING THE TIMING AND EVOLUTION OF
DENSE FOG.
RIVER FLOOD POINTS PRESENTLY BEING UPDATED. PAWCATUCK RIVER AT
WESTERLY AND THE FARMINGTON RIVER AT SIMSBURY REMAIN IN FLOOD.
OTHERWISE THE REMAINDER OF THE FORECAST MIRACULOUSLY REMAINS ON
TRACK. WINDS TURNING WESTERLY BEHIND THE FRONT ALLOWING TEMPS TO
FALL AS CLEARING PROCEEDS DOWN TO LOWS AROUND THE MID- TO UPPER-
40S. WILL NEED TO MONITOR FOR PATCHY FOG ACROSS THE INTERIOR AS
RESIDUAL RAINS WILL LIKELY KEEP DEWPOINTS HIGH AS TEMPS DROP.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
FRIDAY...
SHORTWAVE WILL PUSH COOLER TEMPS ALOFT OVER THE REGION ALLOWING
FOR LAPSE RATES TO STEEPEN. MID-LEVEL MOISTURE IS JUST ENOUGH TO
SPARK SOME SCT SHOWERS ACROSS THE AREA. BELIEVE BEST LOCATION TO
SEE RAIN WILL BE ACROSS SOUTHERN NH AND INTO NORTHERN MA...WHICH
IS CLOSEST TO THE UPPER LEVEL DISTURBANCE. CONVECTIVE PARAMETERS
ARE LIMITED SO DO NOT ANTICIPATE ANY STRONG STORMS. DIURNAL CU
WILL ALSO BE AROUND. GUIDANCE IS SHOWING GOOD MIXING UP TO
850MB...SO BELIEVE SOME GUSTY WINDS NEAR 20-25 MPH WILL OCCUR WITH
TEMPS WARMING INTO THE MID 60S WITH A FEW SPOTS HITTING NEAR 70F.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
BIG PICTURE... THIS PORTION OF THE FORECAST IS LARGELY CONTROLLED BY
THE SLOW BREAKDOWN OF A REX BLOCK OVER THE NORTHWEST USA. THIS BLOCK
IS PREVENTING A STRONG ENOUGH FLOW TO DEVELOP TO PUSH A PERSISTENT
LOW IN THE MID LEVELS OFFSHORE. THIS REX BLOCK IS FORECAST TO BREAK
DOWN SATURDAY...WHICH SHOULD FINALLY GET THINGS MOVING. THE MID
LEVEL LOW AT LEAST PARTIALLY RESPONSIBLE FOR OUR RECENT UNSETTLED
AND UNSEASONABLY COOL WEATHER MOVES EAST OF OUR REGION MONDAY. THAT
WOULD LEAVE SOUTHERN NEW ENGLAND UNDER THE INFLUENCE OF MODEST MID
LEVEL RIDGING FOR MOST OF NEXT WEEK.
THE DAILIES...
FRIDAY NIGHT AND SATURDAY...
CYCLONIC FLOW AT THE SURFACE WITH WEAK SHORTWAVES PASSING OVERHEAD.
EXPECTING SOME CLOUDS...WITH A GREATER RISK FOR SHOWERS ACROSS
NORTHWEST MA AND SOUTHWEST NH. THERE IS AN OUTSIDE CHANCE OF A
THUNDERSTORM ACROSS THOSE AREAS SATURDAY....BUT INSTABILITY IS
LIMITED.
SUNDAY...A VERY STRONG UPPER LEVEL LOW WILL MOVE ACROSS NEW ENGLAND.
IT WILL BE ACCOMPANIED BY A VERY COLD POOL OF AIR ALOFT...
APPROACHING -30C AT 500 MB. THIS COLD POOL WILL RAPIDLY DESTABILIZE
THE ATMOSPHERE...RESULTING IN SHOWERS AT LEAST. THUNDERSTORMS WOULD
BE MORE LIKELY SUNDAY AFTERNOON AND EVENING...PROVIDED ENOUGH
INSTABILITY COULD BE GENERATED. SMALL HAIL OR ICE PELLETS COULD ALSO
RESULT DUE TO THE LOWER EXTENT OF COLDER AIR.
MONDAY INTO THURSDAY...UPPER LOW MOVES OFF TO THE EAST BY MONDAY...
BUT STILL RELATIVELY COOL ALOFT. SO LIKELY TO BE MORE DIURNAL
CUMULUS FORMING AT LEAST ON MONDAY. UPPER RIDGE BUILDS TO THE WEST
AND SHOULD BRING A WARMING TREND AROUND MIDWEEK...BUT THIS COULD BE
INTERRUPTED FROM MANCHESTER-BOSTON-CAPE COD IF A BACKDOOR
COLD/SEABREEZE FRONT FORMS AND PUSHES ONSHORE. A VERTICAL LOW
PRESSURE OVER THE MARITIMES AND NORTH-NORTHWEST FLOW ALOFT SIGNAL
THAT AS A POSSIBILITY... ESPECIALLY TUESDAY INTO THURSDAY WHEN
SURFACE WINDS ARE LIGHTER.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH THURSDAY NIGHT/...MODERATE CONFIDENCE.
2Z UPDATE...
LINE OF SHOWERS PUSHING E AND OFFSHORE. FOG AN ISSUE TO THE SE
WITH VSBYS DOWN TO A 1/4SM. ALL THIS SHOULD CONCLUDE AS A COLD
FRONT PUSHING ACROSS THE TERMINALS WITH W WINDS TO THE REAR. WILL
NEED TO MONITOR FOR THE DEVELOPMENT OF FOG ACROSS INTERIOR
TERMINALS TOWARDS MORNING. OTHERWISE LOW-END VFR AND MVFR CIGS
WITH SOME SCT -SHRA ACTIVITY ACROSS THE INTERIOR N ON FRIDAY.
KBOS TERMINAL...MODERATE CONFIDENCE. WILL KEEP FOG OUT OF THE
TERMINAL UPON EVALUATING WEB CAMS AND WIND DIRECTION. COLD FRONT
RIGHT ON THE DOOR STEP. SHOWERS SHOULD STAY TO THE N. OTHERWISE
VFR.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...MODERATE CONFIDENCE.
FRIDAY NIGHT THROUGH SATURDAY...HIGH CONFIDENCE. VFR CONDITIONS.
EXCEPTION COULD BE WIDELY SCATTERED MVFR CIGS/VSBYS IN
AFTERNOON/EVENING SHOWERS MAINLY NW MA AND SW NH. ISOLATED TSTM
POSSIBLE IN THOSE AREAS SAT.
SUNDAY...MODERATE CONFIDENCE. VFR BECOMING MVFR IN SCATTERED
AFTERNOON/EVENING TSTMS. LOCAL IFR POSSIBLE IN ISOLATED STRONGER
THUNDERSTORMS WITH HAIL.
MONDAY...VFR. GUSTY NW WINDS...ESPECIALLY NEAR THE COAST.
TUESDAY...VFR. W TO NW WINDS. LOCAL SEABREEZES POSSIBLE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH THURSDAY NIGHT/...HIGH CONFIDENCE.
SOUTHERLY WINDS OVER THE WATER WILL CONTINUE TO GUST BETWEEN 20-25
KT THIS EVENING. OTHERWISE WINDS WILL SHIFT TO THE NW LATE
TONIGHT DUE TO A COLD FRONTAL PASSAGE. A FEW SCT SHOWERS WITH AN
ISOLATED THUNDERSTORM IS POSSIBLE...BUT HAVE LOW CONFIDENCE.
DENSE FOG WILL BE POSSIBLE PRIOR TO FRONTAL PASSAGE. HAVE EXTENDED
THE SCA ACCORDINGLY TO BE MORE IN LINE WITH BOTH SEAS AND WINDS.
CONDITIONS IMPROVE INTO FRIDAY MORNING WITH WINDS SHIFTING FROM
THE NW BACK A MORE WESTERLY DIRECTION. SEAS WILL SLOWLY SUBSIDE AS
WINDS WILL BE GENERALLY LIGHT ESP AWAY FROM THE COASTLINE.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...MODERATE CONFIDENCE.
FRIDAY NIGHT...LINGERING 5-6 FOOT SWELL ON THE SOUTHERN WATERS WILL
SLOWLY DIMINISH. SMALL CRAFT HEADLINES EXPECTED ON THE SOUTHERN
EXPOSED WATERS.
SATURDAY...WINDS BELOW 20 KNOTS/SEAS BELOW 5 FEET.
SUNDAY-MONDAY...INCREASING WEST WINDS SUNDAY WITH FREQUENT GUSTS
25 TO 30 KNOTS SUNDAY NIGHT... SHIFTING TO NORTHWEST MONDAY. SEAS
BUILDING TO 5-8 FEET ON THE OUTER WATERS. SMALL CRAFT ADVISORY
HEADLINES WILL BE NEEDED.
TUESDAY...WINDS AND SEAS REMAIN LESS THAN 20KT AND 5 FEET
RESPECTIVELY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...DENSE FOG ADVISORY UNTIL 2 AM EDT FRIDAY FOR MAZ018>024.
NH...NONE.
RI...DENSE FOG ADVISORY UNTIL 2 AM EDT FRIDAY FOR RIZ004-006>008.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT FRIDAY FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL 9 PM EDT FRIDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...SIPPRELL
SHORT TERM...DUNTEN
LONG TERM...BELK
AVIATION...BELK/DUNTEN
MARINE...BELK/DUNTEN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
803 PM EDT THU MAY 1 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE OVER THE REGION OVERNIGHT ALLOWING FOR
SCATTERED SHOWERS AND A ISOLATED THUNDERSTORM THIS EVENING.
OTHERWISE DRY WEATHER FOR THE OVERNIGHT PERIOD WITH ANOTHER ROUND
OF SCATTERED SHOWERS ON FRIDAY. A WEAK DISTURBANCE WILL BRING A
CHANCE OF SHOWERS SATURDAY. A STRONGER DISTURBANCE SUNDAY MAY
PRODUCE ISOLATED THUNDERSTORMS WITH HAIL. DRIER AND SEASONABLE
WEATHER FOLLOWS FOR MOST OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
730 PM UPDATE....
ENOUGH SUNSHINE DEVELOPED LATE THIS AFTERNOON TO DEVELOP A
SEABREEZE ALONG THE EAST MA COAST. THIS BROUGHT LOW CLOUDS AND FOG
BACK INTO BOSTON...ALONG WITH LOWER TEMPERATURES.
A COLD FRONT WAS JUST ENTERING WESTERN MA. THIS FRONT IS EXPECTED
TO REACH THE I-95 CORRIDOR BETWEEN BOSTON AND PROVIDENCE TOWARD
MIDNIGHT...THEN MOVE FARTHER OFFSHORE DURING THE EARLY MORNING
HOURS.
THERE ARE ENOUGH SPOTS WITH LOW VISIBILITY ALONG THE SOUTH COAST
OF MA AND RI. DECIDED TO KEEP THE DENSE FOG ADVISORY GOING...
ALTHOUGH THERE ARE SOME AREAS WHICH HAVE IMPROVED FROM EARLIER
TODAY. EXPECTING STRONGER WINDS TO DEVELOP IMMEDIATELY AHEAD OF
THE COLD FRONT THIS EVENING...WHICH SHOULD HELP DISPERSE THE FOG.
WINDS BECOMING WEST TO NORTHWEST LATER TONIGHT WILL PUT THE
FINISHING TOUCHES DISPERSING THE FOG.
REGIONAL RADARS SHOWING SCATTERED LIGHT SHOWERS. THESE SHOWERS ARE
NEITHER VERY STRONG NOR PRODUCING MUCH RAINFALL. 01/22Z HRRR IS
MORE ROBUST THAN THE 01/22Z RAP. SPLIT THE DIFFERENCE BETWEEN THE
TWO.
PREVIOUS DISCUSSION...
PRECIP OVER THE CAPE THIS AFTERNOON WILL MOVE OFFSHORE WITHIN THE
NEXT HOUR OR TWO. OTHERWISE THE ATTENTION TURNS TO THE SCATTERED
SHOWERS ACROSS UPSTATE NY ASSOCIATED WITH THE APPROACHING COLD
FRONT. AS CLOUDS CONTINUE TO BREAK OUT TEMPERATURES HAVE BEGUN TO
RISE INTO THE 60S WITH WILLIMANTIC THE CLOSEST SITE TO BE CLOSE TO
70F THIS AFTERNOON AS COLD AIR DAMMING KEPT MANY SITES WELL BELOW
FORECAST. THESE SHOWERS MAY STRENGTHEN IN A FEW HOURS ACROSS
UPSTATE NY BUT LOOKING AT THE CONVECTIVE PARAMETERS APPEARS THAT
FAVORABLE CONDITIONS DROP OFF RIGHT ACROSS THE BERKSHIRES. FOR NOW
AM NOT ANTICIPATING ANY WIDE SPREAD CONVECTIVE WEATHER...PERHAPS
JUST LEFTOVERS FROM WHAT IS CURRENTLY DEVELOPING.
ISSUED A DENSE FOG ADV FOR THE IMMEDIATE SOUTH COASTLINE OF RI AND
THE MASS ISLANDS AS VSBYS WERE AT OR BELOW 1/4 MI FOR SEVERAL
HOURS. MAY NEED TO EXTEND INTO THE CAPE BUT WILL EVALUATE. LATEST
OBS AS 1845Z SHOW THAT MANY LOCALES ARE STILL AT OR BELOW A MILE.
BELIEVE THAT ALTHOUGH CONDITIONS MAY RISE FOR A SHORT BIT...THEY
WILL FALL BACK AND BELOW 1/4 MI AS COLD FRONT APPROACHES THE
REGION...SOUTHERLY WINDS WILL PICK UP DRAGGING THESE HIGH
DEWPOINTS OVER THE COOLER WATER. THIS WILL CONTINUE TO ADVECT THE
FOG UNTIL THE FRONT PASSES SOMETIME CLOSE TO MIDNIGHT.
AFTER MIDNIGHT...
WEAK WAVE WILL PUSH THE COLD FRONT ACROSS SOUTHERN NEW ENGLAND
TONIGHT ALLOWING THE SOUTHERLY WINDS TO GO NORTHWEST. STILL A LOT
OF MOISTURE WILL BE AROUND AT THE SURFACE AND LOW-LEVELS WITH THE
UPPER LEVELS DRYING OUT OVERNIGHT. THIS MAY ALLOW FOR SOME PATCHY
FOG TO DEVELOP ACROSS PORTIONS OF THE INTERIOR. CONFIDENCE
HOWEVER IS LOW THAT THIS WILL OCCUR BUT IT IS SOMETHING THAT NEEDS
TO BE WATCHED. OTHERWISE EXPECT CLOUDS TO CLEAR OUT CLOSER TO
DAWN...KEEPING TEMPS FROM RADIATING OUT. OVERNIGHT TEMPS WILL BE
IN THE MID 40S TO LOW 50S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
FRIDAY...
SHORTWAVE WILL PUSH COOLER TEMPS ALOFT OVER THE REGION ALLOWING
FOR LAPSE RATES TO STEEPEN. MID-LEVEL MOISTURE IS JUST ENOUGH TO
SPARK SOME SCT SHOWERS ACROSS THE AREA. BELIEVE BEST LOCATION TO
SEE RAIN WILL BE ACROSS SOUTHERN NH AND INTO NORTHERN MA...WHICH
IS CLOSEST TO THE UPPER LEVEL DISTURBANCE. CONVECTIVE PARAMETERS
ARE LIMITED SO DO NOT ANTICIPATE ANY STRONG STORMS. DIURNAL CU
WILL ALSO BE AROUND. GUIDANCE IS SHOWING GOOD MIXING UP TO
850MB...SO BELIEVE SOME GUSTY WINDS NEAR 20-25 MPH WILL OCCUR WITH
TEMPS WARMING INTO THE MID 60S WITH A FEW SPOTS HITTING NEAR 70F.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
BIG PICTURE... THIS PORTION OF THE FORECAST IS LARGELY CONTROLLED BY
THE SLOW BREAKDOWN OF A REX BLOCK OVER THE NORTHWEST USA. THIS BLOCK
IS PREVENTING A STRONG ENOUGH FLOW TO DEVELOP TO PUSH A PERSISTENT
LOW IN THE MID LEVELS OFFSHORE. THIS REX BLOCK IS FORECAST TO BREAK
DOWN SATURDAY...WHICH SHOULD FINALLY GET THINGS MOVING. THE MID
LEVEL LOW AT LEAST PARTIALLY RESPONSIBLE FOR OUR RECENT UNSETTLED
AND UNSEASONABLY COOL WEATHER MOVES EAST OF OUR REGION MONDAY. THAT
WOULD LEAVE SOUTHERN NEW ENGLAND UNDER THE INFLUENCE OF MODEST MID
LEVEL RIDGING FOR MOST OF NEXT WEEK.
THE DAILIES...
FRIDAY NIGHT AND SATURDAY...
CYCLONIC FLOW AT THE SURFACE WITH WEAK SHORTWAVES PASSING OVERHEAD.
EXPECTING SOME CLOUDS...WITH A GREATER RISK FOR SHOWERS ACROSS
NORTHWEST MA AND SOUTHWEST NH. THERE IS AN OUTSIDE CHANCE OF A
THUNDERSTORM ACROSS THOSE AREAS SATURDAY....BUT INSTABILITY IS
LIMITED.
SUNDAY...A VERY STRONG UPPER LEVEL LOW WILL MOVE ACROSS NEW ENGLAND.
IT WILL BE ACCOMPANIED BY A VERY COLD POOL OF AIR ALOFT...
APPROACHING -30C AT 500 MB. THIS COLD POOL WILL RAPIDLY DESTABILIZE
THE ATMOSPHERE...RESULTING IN SHOWERS AT LEAST. THUNDERSTORMS WOULD
BE MORE LIKELY SUNDAY AFTERNOON AND EVENING...PROVIDED ENOUGH
INSTABILITY COULD BE GENERATED. SMALL HAIL OR ICE PELLETS COULD ALSO
RESULT DUE TO THE LOWER EXTENT OF COLDER AIR.
MONDAY INTO THURSDAY...UPPER LOW MOVES OFF TO THE EAST BY MONDAY...
BUT STILL RELATIVELY COOL ALOFT. SO LIKELY TO BE MORE DIURNAL
CUMULUS FORMING AT LEAST ON MONDAY. UPPER RIDGE BUILDS TO THE WEST
AND SHOULD BRING A WARMING TREND AROUND MIDWEEK...BUT THIS COULD BE
INTERRUPTED FROM MANCHESTER-BOSTON-CAPE COD IF A BACKDOOR
COLD/SEABREEZE FRONT FORMS AND PUSHES ONSHORE. A VERTICAL LOW
PRESSURE OVER THE MARITIMES AND NORTH-NORTHWEST FLOW ALOFT SIGNAL
THAT AS A POSSIBILITY... ESPECIALLY TUESDAY INTO THURSDAY WHEN
SURFACE WINDS ARE LIGHTER.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH THURSDAY NIGHT/...MODERATE OVERALL CONFIDENCE.
CONDITIONS ARE IMPROVING FROM WEST TO EAST THIS EVENING. HOWEVER
IT MAY TAKE SOME TIME TO PUSH THE IFR CIGS OFFSHORE OVERNIGHT.
COLD FRONT WILL PASS BETWEEN 03Z-09Z ALLOWING FOR SOUTHERLY WINDS
TO SHIFT FROM SOUTH TO NORTHWEST. PATCHY DENSE FOG ALONG THE SOUTH
COAST WILL IMPROVE BEHIND FRONTAL PASSAGE. OTHERWISE VFR DAY
TOMORROW WITH THE POSSIBILITY OF SOME MVFR CIGS IN SCT SHOWERS
NORTH OF THE MASS PIKE.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF TENDS...LOW CONFIDENCE ON
TIMING. STILL SOME CONCERN THROUGH 02/02Z LOW CLOUDS AND FOG WILL
RETURN. LOWER CONDITIONS WILL BE MORE PREVALENT WITH AN EAST WIND.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...MODERATE CONFIDENCE.
FRIDAY NIGHT THROUGH SATURDAY...HIGH CONFIDENCE. VFR CONDITIONS.
EXCEPTION COULD BE WIDELY SCATTERED MVFR CIGS/VSBYS IN
AFTERNOON/EVENING SHOWERS MAINLY NW MA AND SW NH. ISOLATED TSTM
POSSIBLE IN THOSE AREAS SAT.
SUNDAY...MODERATE CONFIDENCE. VFR BECOMING MVFR IN SCATTERED
AFTERNOON/EVENING TSTMS. LOCAL IFR POSSIBLE IN ISOLATED STRONGER
THUNDERSTORMS WITH HAIL.
MONDAY...VFR. GUSTY NW WINDS...ESPECIALLY NEAR THE COAST.
TUESDAY...VFR. W TO NW WINDS. LOCAL SEABREEZES POSSIBLE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH THURSDAY NIGHT/...HIGH CONFIDENCE.
SOUTHERLY WINDS OVER THE WATER WILL CONTINUE TO GUST BETWEEN 20-25
KT THIS EVENING. OTHERWISE WINDS WILL SHIFT TO THE NW LATE
TONIGHT DUE TO A COLD FRONTAL PASSAGE. A FEW SCT SHOWERS WITH AN
ISOLATED THUNDERSTORM IS POSSIBLE...BUT HAVE LOW CONFIDENCE.
DENSE FOG WILL BE POSSIBLE PRIOR TO FRONTAL PASSAGE. HAVE EXTENDED
THE SCA ACCORDINGLY TO BE MORE IN LINE WITH BOTH SEAS AND WINDS.
CONDITIONS IMPROVE INTO FRIDAY MORNING WITH WINDS SHIFTING FROM
THE NW BACK A MORE WESTERLY DIRECTION. SEAS WILL SLOWLY SUBSIDE AS
WINDS WILL BE GENERALLY LIGHT ESP AWAY FROM THE COASTLINE.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...MODERATE CONFIDENCE.
FRIDAY NIGHT...LINGERING 5-6 FOOT SWELL ON THE SOUTHERN WATERS WILL
SLOWLY DIMINISH. SMALL CRAFT HEADLINES EXPECTED ON THE SOUTHERN
EXPOSED WATERS.
SATURDAY...WINDS BELOW 20 KNOTS/SEAS BELOW 5 FEET.
SUNDAY-MONDAY...INCREASING WEST WINDS SUNDAY WITH FREQUENT GUSTS
25 TO 30 KNOTS SUNDAY NIGHT... SHIFTING TO NORTHWEST MONDAY. SEAS
BUILDING TO 5-8 FEET ON THE OUTER WATERS. SMALL CRAFT ADVISORY
HEADLINES WILL BE NEEDED.
TUESDAY...WINDS AND SEAS REMAIN LESS THAN 20KT AND 5 FEET
RESPECTIVELY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR MAZ023-024.
NH...NONE.
RI...DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR RIZ006>008.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR
ANZ231>234.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT FRIDAY FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ251.
SMALL CRAFT ADVISORY UNTIL 9 PM EDT FRIDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...DUNTEN
SHORT TERM...DUNTEN
LONG TERM...BELK
AVIATION...BELK/DUNTEN
MARINE...BELK/DUNTEN
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 MOUNT HOLLY NJ
910 PM EDT THU MAY 1 2014
.SYNOPSIS...
A COLD FRONT WILL PUSH FARTHER OFFSHORE TONIGHT AS LOW PRESSURE
CONTINUES TO DRIFT OUT OF THE GREAT LAKES REGION THEN INTO SOUTHERN
CANADA. THIS LOW WILL DRIFT EASTWARD THROUGH THE WEEKEND AND INTO
THE CANADIAN MARITIMES BY MONDAY. A COUPLE OF WEAK SURFACE TROUGHS
WILL CROSS THE REGION FRIDAY AND SATURDAY, FOLLOWED BY A COLD FRONT
ON SUNDAY. HIGH PRESSURE IS EXPECTED TO BUILD SOUTHWARD ACROSS THE
AREA MONDAY INTO TUESDAY, AND POSSIBLY WEDNESDAY FROM CENTRAL
CANADA. A WARM FRONT IS EXPECTED TO APPROACH THE AREA FROM THE SOUTH
WEDNESDAY NIGHT INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE RAP HAS DONE THE BEST WITH KEYING IN ON THE SFC BASED INSTAB
AND HAS BEEN USED THIS EVENING TO UPDATE THE GRIDS AND THE INCLUSION
OF THUNDER. FROM THIS POINT FORWARD, EVEN IT IS LOSING SFC BASED
INSTABILITY AND EXPECTED COVERAGE AND INTENSITY SHOULD CONTINUE
ITS DOWNSLIDE. CONVERSELY, THE HRRR APPEARS A BIT SLOW WITH THE
SOUTHERN SWIPE AROUND MIDN AND WE SPED UP ITS SOLUTION A BIT IN
TIMING, BUT WITH A MORE SUPPRESSED LOOK AND JUST SHOWERS.
THE SFC FRONT SHOULD NOW GET AN EXTRA PUSH FROM THE CONVECTIVE
COOL POOL, AS WE ARE SEEING ABOUT 25KTS ON 88D IMAGERY. THIS
SHOULD GET IT MOVING AGAIN. THE LAV GUIDANCE SEEMS TO HAVE
CAPTURED THE TEMPERATURES PRETTY WELL AND WAS USED FOR THE UPDATE,
NOT TOO MANY CHANGES OVERALL THERE.
THE SFC LOW AND UPR TROF RESPONSIBLE FOR ALL OF THE RAIN WED AND
LAST NIGHT IS SLOWLY EXITING THE REGION AND CONDS ARE IMPROVING. AN
UPR LOW REMAINS NR JAMES BAY WITH ANOTHER NR THE GRTLKS. A SFC LOW
WAS ALSO NR JAMES BAY. A WK CDFNT WILL CROSS THE REGION TONIGHT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
A NICE DAY IS IN STORE ON FRI WITH SWLY TO W FLOW, GENLY DRY WX AND
WARM TEMPS. WITH THE UPR LOW STILL ROTATING NR JAMES BY, THERE
COULD BE SOME SCT SHWRS MAINLY OVER THE NWRN AREAS BUT THAT IS ABOUT
IT. THE WIND WILL BECOME A BIT GUSTY IN THE AFTN WITH GUSTS AROUND
20 TO 25 MPH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
ANY SHOWER ACTIVITY DURING THE DAY FRIDAY SHOULD DISSIPATE BY SUNSET
WITH THE LOSS OF DAYTIME HEATING, SO NO POPS ARE FORECAST FRIDAY
NIGHT INTO SATURDAY MORNING.
AS WE MOVE INTO SATURDAY, A SHORT WAVE/VORT MAX WILL BE MOVING
ACROSS THE AREA, WHILE A WEAK SURFACE TROUGH MOVES THROUGH AS LOW
PRESSURE MOVES INTO SOUTHEASTERN CANADA. THERE IS SOME MOISTURE
TO WORK WITH ON SATURDAY, ESPECIALLY FOR THE NORTHERN HALF OF THE
AREA, SO WE DO HAVE CHANCE/SLIGHT CHANCE POPS. ANY SHOWER ACTIVITY
WILL DISSIPATE WITH DAYTIME HEATING AFTER THE SUNSETS, BUT THEY
COULD LAST FOR A COUPLE OF HOURS AFTER SUNSET, SO POPS CONTINUE
INTO THE EARLY EVENING.
ON SUNDAY, THE LOW ACROSS CANADA WILL MOVE INTO NEW ENGLAND AND
BRING A COLD FRONT ACROSS THE AREA. A STRONGER SHORT WAVE/VORT MAX
WILL SWING THROUGH THE AREA DURING THE DAY, AN COMBINED WITH THE
AVAILABLE MOISTURE, SCATTERED SHOWERS ARE EXPECTED ACROSS THE AREA.
THE FRONT IS EXPECTED TO MOVE OFFSHORE LATE IN THE DAY, SO
PRECIPITATION CHANCES SHOULD END BY SUNDAY EVENING.
THE AFOREMENTIONED COLD FRONT SINKS SOUTH OF OUR AREA AND STALLS
ACROSS THE CAROLINAS THROUGH MID-WEEK. MEANWHILE, HIGH PRESSURE IS
EXPECTED TO BUILD ACROSS THE AREA FROM CENTRAL CANADA MONDAY INTO
TUESDAY. HOWEVER, THE GFS AND ECMWF DO SHOW SOME QPF MONDAY NIGHT
INTO TUESDAY NIGHT AS THEY PUSH A SHORT WAVE/VORT MAX ACROSS THE
AREA ON THE EASTERN SIDE OF THE UPPER RIDGE THAT BUILDS ACROSS THE
CENTRAL PART OF THE COUNTRY. THERE REMAINS SOME LOCATION AND
TIMING DIFFERENCES, SO WE WILL KEEP SLIGHT CHANCE IN THE FORECAST
FOR NOW BASED ON THE UNCERTAINTY.
FOR WEDNESDAY INTO THURSDAY, THE SURFACE HIGH BUILDS OFFSHORE, WHILE
THE UPPER RIDGE BUILDS CLOSER TO THE AREA. THE FRONTAL BOUNDARY TO
OUR SOUTH ALSO RETURNS NORTHWARD AS A WARM FRONT AND APPROACHES
THE AREA. THEREFORE, PRECIPITATION CHANCE INCREASE FOR THE
WEDNESDAY NIGHT INTO THURSDAY TIME PERIOD.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
00Z TAFS WERE TOO OPTIMISTIC ABOUT VFR CONDITIONS EXCLUSIVELY AT
THE TERMINALS..
IN THE EVENING. SHOWER AND THUNDERSTORM ACTIVITY HAS INCREASED IN
COVERAGE AND AMENDMENTS HAVE BEEN MADE FOR AN HOUR OR TWO OF PCPN.
OTHERWISE, WE ARE EXPECTING SOME LOW AND MID LEVEL VFR CIGS. COLD
FRONT MOVING EAST SHOULD CLEAR THE DELAWARE VALLEY TERMINALS CLOSE
TO THE START TIME OF THE TAFS BUT STRUGGLE TO MOVE EAST THE REST
OF THE EVENING.
BEHIND THE FRONT WINDS WILL BE LIGHT WEST. PRECEDING IT A SEA
BREEZE FRONT HAS MADE IT INTO THE EASTERN NJ COUNTIES AND SHOULD
START STALLING. THERE IS ALSO A BAY BREEZE THAT PASSED KILG. A
GRADUAL VEERING TO THE WEST IS FORECAST FOR THE EASTERN TERMINALS
AND AIRPORTS.
OVERNIGHT, MORE DEBRIS MAINLY MID LEVEL VFR CLOUDS. BUT, WITH
DRIER AIR MOVING IN AND NO FOG BANK OFFSHORE NOW, WE HAVE NO VSBY
RESTRICTIONS. WINDS LIGHT FROM THE WEST.
FRIDAY, WE DID NOT FORECAST A CUMULUS BASED VFR CIG, BUT WE
SUPPOSE ONE MIGHT OCCUR FROM TIME TO TIME, ESPECIALLY INLAND AIRPORTS.
WEST WINDS WILL AVERAGE 10 TO 15 KNOTS WITH GUSTS TO AROUND 20
KNOTS. NO SEA BREEZE FRONT ANTICIPATED.
OUTLOOK...
FRIDAY NIGHT-SATURDAY NIGHT...MOSTLY VFR. AFTERNOON SHOWERS
POSSIBLE SATURDAY. GUSTY SOUTHWEST WINDS 15-20 KNOTS.
SUNDAY...MOSTLY VFR...SHOWERS POSSIBLE ASSOCIATED WITH FRONTAL
PASSAGE WITH BRIEF MVFR CONDITIONS POSSIBLE. GUSTY SOUTHWEST WINDS
EARLY, THEN NORTHWEST LATER BEHIND FRONT AROUND 20-25 KNOTS.
SUNDAY NIGHT-MONDAY NIGHT...MOSTLY VFR. GUSTY NORTHWEST WINDS AROUND
20 KNOTS MONDAY AFTERNOON.
TUESDAY...MOSTLY VFR. SHOWERS POSSIBLE, MAINLY ACROSS THE
SOUTHERN TAF SITES.
&&
.MARINE...
WILL LEAVE THE SCA UP FOR THE OCEAN THRU NOON ON FRI. THIS CUD END
UP BEING A BIT TOO LONG BUT SEAS REMAIN ELEVATED AND NEED TO COME
DOWN. ONCE THE SCA FLAG IS LOWERED, NO ADDITIONAL MARINE FLAGS ARE
EXPECTED FOR THE REMAINDER OF THE NEAR OR SHORT TERM PERIODS.
EARLIER, THERE WAS SOME DENSE FOG OVER THE OCEAN WATERS. WE WILL
CONTINUE THE MENTION OF PATCHY DENSE FOG, BUT NOT ISSUE ANY
ADDITIONAL HEADLINES.
OUTLOOK...
FRIDAY NIGHT-SATURDAY NIGHT...SUB-ADVISORY CONDITIONS EXPECTED,
ALTHOUGH WINDS COULD PERIODICALLY GUST AROUND 20 KNOTS, ESPECIALLY
SATURDAY NIGHT INTO SUNDAY.
SUNDAY-MONDAY...RETURN TO SMALL CRAFT ADVISORY CONDITIONS
POSSIBLE BEHIND A FRONTAL PASSAGE.
MONDAY NIGHT-TUESDAY...RETURN TO SUB-ADVISORY CONDITIONS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT FRIDAY FOR ANZ450>455.
&&
$$
SYNOPSIS...ROBERTSON
NEAR TERM...GIGI/NIERENBERG
SHORT TERM...NIERENBERG
LONG TERM...ROBERTSON
AVIATION...NIERENBERG/ROBERTSON
MARINE...NIERENBERG/ROBERTSON
AREA FORECAST DISCUSSION
NWS MIAMI FL
1001 PM EDT THU MAY 1 2014
.UPDATE...A FEW SHOWERS PERSIST AROUND LAKE OKEECHOBEE, BUT THEY
ARE EXPECTED TO DISSIPATE THROUGH MIDNIGHT WITH TRANQUIL WEATHER
PREVAILING OVERNIGHT. HRRR SHOWS ANY ADDITIONAL SHOWER DEVELOPMENT
OVERNIGHT TAKING PLACE NORTH OF THE LAKE. MADE NO SIGNIFICANT
CHANGES TO THE FORECAST THIS EVENING. PLEASE SEE PREVIOUS
DISCUSSION BELOW FOR MORE FORECAST DETAILS. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 802 PM EDT THU MAY 1 2014/
AVIATION...
THERE CONTINUE TO BE LINGERING SHOWERS ACROSS THE PENINSULA BUT
THE THUNDERSTORMS EARLIER THIS EVENING HAVE DISSIPATED. TERMINALS
KTMB...KOPF AND KMIA MAY EXPERIENCE LIGHT SHOWERS THROUGH 02Z BUT
MAINLY VFR CONDITIONS EXPECTED TO PREVAIL AS WELL AS FOR THE
REMAINING S. FL TERMINALS THIS EVENING THROUGH THE EARLY MORNING
HOURS.
60
PREV DISCUSSION... /ISSUED 222 PM EDT THU MAY 1 2014/
SHORT TERM (TONIGHT-SATURDAY NIGHT)...
THE DEEP LAYER RIDGE THAT HAS DOMINATED THE WEATHER ACROSS SOUTH
FLORIDA THE PAST SEVERAL DAYS WILL BEGIN TO WEAKEN AND SHIFT EAST ON
FRIDAY AND INTO THE WEEKEND. THIS IS IN RESPONSE TO THE LARGE CUT-
OFF LOW THAT HAS BEEN SPINNING ACROSS THE CENTRAL PART OF THE U.S.
GETTING KICKED TO THE NORTHEAST AS UPSTREAM TROUGHS DEVELOP TO ITS
WEST. ALL OF THIS WILL AID IN THE ASSOCIATED COLD FRONT TO SLOWLY
SHIFT SOUTH DOWN THE FLORIDA PENINSULA OVER THE NEXT 48-60 HOURS.
GLOBAL MODELS HAVE BEEN COMING MORE IN LINE WITH EACH OTHER ON THE
TIMING ACROSS SOUTH FLORIDA BUT MORE ON THAT LATER. AT ANY RATE,
STILL EXPECT SOME SHOWER AND THUNDERSTORM DEVELOPMENT ACROSS THE
INTERIOR THIS AFTERNOON AS THE ATMOSPHERE REMAINS QUITE UNSTABLE
WITH A LOW LEVEL SSE FLOW. HOWEVER, THE MID LEVEL LAPSE RATES ARE
NOT AS IMPRESSIVE AS THE PAST FEW DAYS WITH A 3-6KM LAPSE RATE OF
5.6C/KM THIS MORNING COMPARED TO 6.3C/KM FROM WEDNESDAY MORNING AND
7C/KM ON MONDAY.
AS THE FRONT SLOWLY SLIDES TO THE SOUTH ON FRIDAY AND OVER THE EARLY
PART OF THE WEEKEND, MOISTURE WILL BE ON THE INCREASE ESPECIALLY BY
SATURDAY. FORECAST SOUNDINGS SHOW PWAT REMAINING SIMILAR ON FRIDAY
TO TODAY AT AROUND 1.25-1.35 INCHES BUT THEN INCREASING TO 1.6-1.8
INCHES BY SATURDAY AFTERNOON. HOWEVER, THE 500MB TEMPERATURES WARM
OVER THE NEXT FEW DAYS WITH THE RANGE OF -7.5C TO -9C TODAY WARMING
TO RANGE OF -7C TO -8C BY SATURDAY AFTERNOON. IN OTHER WORDS, MID
LEVEL LAPSE RATES WILL BECOME EVEN MORE UNIMPRESSIVE EARLY IN THE
WEEKEND ALONG WITH THE FLOW BECOMING UNIDIRECTIONAL WELL AHEAD OF
THE FRONT. HOWEVER, DUE TO A WARM SURFACE FLOW ALONG WITH THE CLOSE
PROXIMITY OF THE FRONT BY SATURDAY THERE COULD BE SOME STRONGER WIND
GUSTS WITH SOME OF THE CELLS.
LONG TERM (SUNDAY-THURSDAY)...
AS MENTIONED EARLIER ABOUT MODEL CONSENSUS, THE GFS, ECMWF AND NAM
ARE ALL SHOWING THE FRONT MOVING ACROSS SOUTH FLORIDA LATE SATURDAY
INTO EARLY SUNDAY. SO THINK THE NON POP FORECAST FOR SUNDAY MAY HAVE
BEEN A LITTLE PREMATURE SO WILL INCREASE POPS ON SUNDAY TO 30% FOR
THE SOUTHERN PORTIONS AND TAILORING DOWNWARD FARTHER TO THE NORTH.
THE REMAINDER OF THE EXTENDED PERIOD LOOKS TO BE A DRY FORECAST AS A
DEEP LAYER RIDGE ONCE AGAIN BUILDS ACROSS SOUTH FLORIDA.
MARINE...
THE WINDS WILL BECOME A MORE SOUTHERLY DIRECTION FOR FRIDAY INTO
EARLY PART OF THE WEEKEND. THE WINDS WILL THEN VEER TO A
NORTHERLY DIRECTION ON SUNDAY INTO EARLY NEXT WEEK...AS WIND
SPEEDS REMAIN AROUND 15 KNOTS. THIS WILL KEEP THE SEAS BELOW 6
FEET IN BOTH THE ATLANTIC AND GULF WATERS OF SOUTH FLORIDA THROUGH
LATE THIS WEEK BEFORE INCREASING TO AROUND 7 FEET BY LATE THIS
WEEKEND.
SMALL NORTHEAST SWELL WILL BUILD INTO SOUTH FLORIDA ATLANTIC
WATERS INTO THIS WEEKEND. THESE NORTHEAST SWELLS WILL ALLOW FOR
THE CONTINUATION OF THE RISK OF RIP CURRENTS ALONG THE EAST COAST
BEACHES OF SOUTH FLORIDA THROUGH THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 76 88 75 87 / 10 30 20 50
FORT LAUDERDALE 77 87 77 88 / 10 10 10 40
MIAMI 77 87 76 87 / 10 10 10 40
NAPLES 74 86 74 83 / 10 10 20 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 8 AM EDT FRIDAY FOR FLZ168.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
852 PM EDT THU MAY 1 2014
.UPDATE...
HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST OVERNIGHT.
SHORTWAVE ENERGY STILL PROGGED TO ENHANCE LIGHT PRECIPITATION
ACROSS THE SOUTHERN ZONES TOWARDS SUNRISE. HRRR STILL SUPPORTS
THIS...AND WILL NOT MAKE CHANGES TO POPS AT THIS TIME.
HAVE ONLY MADE MINOR CHANGES TO THE HOURLY TEMPS/DEWS.
&&
.PREV DISCUSSION... /ISSUED 721 PM EDT THU MAY 1 2014/
PREV DISCUSSION... /ISSUED 346 PM EDT THU MAY 1 2014/
SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
LATEST SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY MOVING PAINFULLY
SLOW THROUGH THE FORECAST AREA WITH IT NOW STRETCHING FROM
GREENVILLE THROUGH ATHENS AND ATLANTA. AHEAD OF THE FRONT...DEEPER
MOISTURE HAS COMBINED WITH SUBTLE UPPER LEVEL ENERGY TO RESULT IN
CONTINUED GOOD COVERAGE OF SHOWERS AND ISOLATED THUNDERSTORMS.
WITH THIS PARTICULAR SHORTWAVE SHIFTING EAST...SHOULD SEE A
REDUCTION IN POPS THIS EVENING WITH CURRENT LIKELY COVERAGE
REDUCED TO CHANCE POPS.
THIS BREAK LOOKS TO BE SHORT LIVED HOWEVER AS ANOTHER SHORTWAVE
MOVES IN FROM ALABAMA AROUND 06Z TONIGHT ENHANCING AND LIFTING
SHIELD OF PRECIPITATION NORTHWARD. HAVE LEANED CLOSE TO THE NAMMB
WHICH HAS PERFORMED WELL OF LATE AND BRING HEALTHY POP COVERAGE OF
80 PERCENT TO EXTREME SOUTHERN TIER BUT TAPER OFF RAPIDLY TO LESS
THAN 20 FOR THE ATLANTA METRO. FEEL LIKE THUNDER THREAT MAY BE OVER
FOR THIS AFTERNOON AND EVENING BUT MAY RETURN AS EARLY AS MID
MORNING WITH ONLY ISOLATED TSRA PLANNED. HAVE GONE ABOVE GUIDANCE
ON TEMPS TONIGHT AS EXTENSIVE CLOUD COVER SHOULD KEEP SIGNIFICANT
TEMP DROP IN CHECK.
FINAL SHORTWAVE FRIDAY NIGHT AND SATURDAY MORNING IS MORE
SUBSTANTIAL AND SHOULD PRODUCE A CLEARING TREND FOR THE WEEKEND
WITH FRONT FINALLY CLEARING THE AREA AND A RETURN TO MOSTLY SUNNY
CONDITIONS.
DEESE
LONG TERM /SATURDAY THROUGH THURSDAY/...
NO CHANGES MADE TO THE EXTENDED FORECAST AS A DRY FORECAST WILL
CONTINUE. WE WILL MOSTLY BE UNDER MOIST SOUTHERLY FLOW THROUGH THE
EXTENDED...SO WE WILL SEE CLOUDS OFF AN ON THROUGH DAY 7 BUT NO
PRECIP EXPECTED. A DRY BACKDOOR COLD FRONT MOVES CLOSE TO THE FAR
NE EARLY MONDAY BUT LOOKS TO STALL AND MOVE BACK NE INTO TUESDAY.
THE FRONT WILL HAVE VERY LIMITED MOISTURE SO AGAIN NO PRECIP IS
EXPECTED WITH IT. HIGH PRESSURE ALOFT WILL BUILD INTO THE AREA
TUESDAY AND WEDNESDAY CONTINUING TO KEEP THINGS DRY.
FORECAST LOW TEMPERATURES RUNNING AROUND 5 DEGREES BELOW NORMAL
SATURDAY MORNING THEN NEAR TO ABOVE NORMAL SUNDAY TO THURSDAY.
01
AVIATION...
00Z UPDATE...
COLD FRONT HAS FINALLY PUSHED SOUTH OF THE CWFA EARLY THIS
EVENING. CLOUDS CONTINUE TO LINGER OVER THE SE PART OF THE STATE.
EXPECT A PIECE OF SHORTWAVE ENERGY TO ENHANCE CLOUD COVER
OVERNIGHT AND EARLY TOMORROW. CIGS SHOULD REMAIN VFR AND SETTLE
AROUND 5KFT. NO VSBY RESTRICTIONS ANTICIPATED EITHER. WINDS SHOULD
REMAIN W/NW AT 10KT OR BELOW THROUGH THE PERIOD.
//ATL CONFIDENCE...00Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 50 72 48 77 / 20 20 5 5
ATLANTA 52 70 51 75 / 10 10 5 5
BLAIRSVILLE 44 65 43 71 / 5 5 5 5
CARTERSVILLE 46 69 46 75 / 5 5 5 5
COLUMBUS 53 72 51 77 / 50 50 20 5
GAINESVILLE 51 68 50 74 / 5 5 0 5
MACON 52 70 48 77 / 60 60 20 5
ROME 46 68 46 76 / 5 5 0 5
PEACHTREE CITY 47 71 45 76 / 20 20 5 5
VIDALIA 57 67 53 76 / 80 80 50 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ATWELL
LONG TERM....ATWELL
AVIATION...ATWELL
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 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 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...UPDATED
NWS CHICAGO/ROMEOVILLE IL
917 PM CDT THU MAY 1 2014
.DISCUSSION...
915 PM CDT
VERY FEW CHANGES WERE MADE TO THE GOING FORECAST. BUMPED UP MINS A
COUPLE DEGREES AND TWEAKED POPS A LITTLE BUT ALL VERY SUBTLE
CHANGES.
THERE STILL IS A CLOSED 500MB CIRCULATION WITH OUR SEEMINGLY NEVER
DEPARTING SYSTEM. THIS CLOSED CIRCULATION HAS BEEN THE CASE ON
UPPER AIR MAPS SINCE 12Z SUNDAY...HAVING ONLY MOVED FROM CO TO MI
IN THAT FIVE AND A HALF DAY SPAN! WHILE THE DEEP SATURATION
REMAINS IN PLACE OVER THE AREA...NEGATIVE VORTICITY ADVECTION INTO
THE AREA AND MORE STABLE AIR IN THE LOW/MID LEVELS SHOULD CONTINUE
A DIMINISHING TREND OF LIGHT SHOWERS THESE NEXT FEW HOURS. THE
THICK CLOUD COVER AND REGIONALLY OBSERVED LOWER 40 DEW POINTS
LOOK TO KEEP TEMPERATURES NEARLY STEADY MUCH OF THE NIGHT. BUMPED
UP MINS 2-3 DEGREES BECAUSE OF THIS.
MTF
&&
.PREV DISCUSSION...
308 PM CDT
MAIN FORECAST CHALLENGES/CONCERNS ARE WITH PRECIP TRENDS IN THE
NEAR TERM AND FRIDAY...AS WELL AS A SLOW TREND BACK TOWARDS MORE
NORMAL TEMPS THIS WEEKEND.
LATEST RADAR IMAGERY DEPICTING PERSISTENT SHOWERS TODAY STILL
ONGOING OVER MUCH OF THE CWA THIS AFTERNOON WITH A MORE SOLID AREA
CURRENTLY EXITING OVER FAR NORTHEAST ILLINOIS. THESE SHOWERS STILL
IN RESPONSE TO A LARGE/DYNAMIC UPPER LEVEL SYSTEM SLOWLY MOVING
EAST ACROSS THE UPPER MIDWEST AND GREAT LAKES REGION. OF
PARTICULAR INTEREST ARE A FAIRLY STOUT VORT LOBE WRAPPING AROUND
THE CENTER OF THIS SYSTEM...AND A MORE SHEARED OUT WAVE DROPPING
TO THE SOUTHEAST THROUGH EASTERN IOWA AND NORTHERN ILLINOIS. MODEL
GUIDANCE IN GOOD AGREEMENT WITH THIS SLOW MOVING SYSTEM TO OPEN
AND REALLY BEGIN KICKING OFF TO THE EAST...WHILE UPPER LEVEL
TROUGHING CONTINUES ACROSS THE CENTRAL CONUS. WHAT THIS WILL MEAN
IN THE NEAR TERM IS FOR ANY SHOWER DEVELOPMENT TO BEGIN A
DIMINISHING TREND THIS AFTERNOON INTO THE EVENING. AS THE SHEARED
OUT WAVE CONTINUES TO EXIT TO THE EAST/SOUTHEAST THIS
EVENING...COULD SEE SOME LINGERING SHOWERS ACROSS THE EAST AND
SOUTHEAST. SO HAVE LOW CHANCE POPS FOR MOST AREAS THIS
EVENING...KEEPING SLIGHTLY HIGHER POPS FROM PONTIAC NORTHEAST TO
GARY/VALPARAISO AND AREAS SOUTHEAST. DESPITE SOME ISOLATED
DEVELOPMENT MORE TOWARDS THE MIDNIGHT TIME FRAME...AN OVERALL DRY
PERIOD IS LIKELY DEFINITELY AFTER MIDNIGHT. COLDER TEMPS ALOFT
WILL TRY TO MODERATE SOME OVERNIGHT...BUT WITH STILL ANOTHER COLD
NIGHT EXPECTED WITH TEMPS AROUND 40.
PATTERN WILL REMAIN HIGHLY AMPLIFIED ON FRIDAY WITH MID/UPPER
LEVEL TROUGH STILL IN PLACE ACROSS THE CENTRAL CONUS...AND WITH
STRONG VORT MAX STILL DEPARTING TO THE EAST OF THE AREA. FRIDAY
WILL START OFF DRY AS BEST PVA WILL BE SITUATED AWAY FROM THE CWA
DESPITE UPPER LEVEL TROUGH OVERHEAD. NOT OVERLY EXCITED FOR TOO
MUCH WARMING ON FRIDAY AS CLOUD COVER WILL STILL BE IN PLACE AND
WITH A CONTINUED SLOW MODERATING TREND. SO DID BRING DOWN MAX
TEMPS A DEGREE OR TWO...WITH UPPER 50S APPEARING LIKELY ACROSS THE
CWA. UPPER LEVEL TROUGH WILL BEGIN SHIFTING TO THE EAST LATE IN
THE DAY BUT WITH NORTHWEST FLOW NOW ALLOWING A FAIRLY STOUT
SHORTWAVE TROUGH TO APPROACH FROM THE NORTHERN PLAINS AND UPPER
MIDWEST DURING THIS PERIOD. THIS APPROACHING MID LEVEL ENERGY AND
SURFACE TROUGH WILL ALLOW FOR SHOWER DEVELOPMENT TO ONCE AGAIN BE
ON THE INCREASE ACROSS THE CWA LATE IN THE DAY FRIDAY...INITIALLY
ACROSS THE FAR NORTHERN CWA. THEN AS BETTER FORCING SWINGS ACROSS
THE CWA DURING FRIDAY EVENING...SHOULD OBSERVE PRECIP SHIELD
LIKEWISE DO THE SAME. DID INCREASE POPS TO HIGH CHANCE INITIALLY
FOR THE NORTHERN HALF THE CWA THROUGH THE MID NIGHT TIME FRAME AND
THEN SHIFT THESE POPS OVER THE SOUTHEAST THIRD AFTER MIDNIGHT.
SHOWERS ARE ONLY LIKELY WITHOUT THUNDER DESPITE SOME STRONGER
FORCING MOVING OVERHEAD AND SOME GUIDANCE ADVERTISING SOME STEEPER
MID LEVEL LAPSE RATES ADVECTING ACROSS THE REGION. IF THUNDER WERE
TO OCCUR LATE FRIDAY...IT WOULD BE BRIEF/ISOLATED AND OCCUR
OUTSIDE OF THE CWA WELL TO THE NORTHWEST.
WITH THIS DEPARTING ENERGY FRIDAY NIGHT INTO SATURDAY...A DRYING
TREND IS LIKELY SATURDAY INTO SATURDAY NIGHT. WARMER TEMPS ALOFT
AND DRYING/CLEARING ON SATURDAY SHOULD FINALLY ALLOW FOR A RETURN
TO 60S ON SATURDAY...WITH UPPER 60S BECOMING LIKELY FOR THE
SOUTHERN HALF OF THE CWA.
RODRIGUEZ
LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...
HIGH PRESSURE CENTERED OVER THE SOUTHERN PART OF THE LAKE SUNDAY
EVENING WILL KEEP WINDS CALM AND OVERNIGHT TEMPERATURES FAIRLY COOL
MAINLY IN THE NORTHERN PART OF THE CWA. MONDAY AFTERNOON
TEMPERATURES WARM INTO THE LOWER AND MID/UPPER 60S INLAND DUE TO WAA
ALOFT FROM A DEVELOPING LOW PRESSURE IN THE CENTRAL PLAINS THAT WILL
SLOWLY TRACK EAST THROUGH LATE IN THE WORK WEEK. PERSISTENT ONSHORE
FLOW WILL KEEP THE LAKEFRONT MUCH COOLER ON MONDAY. HAVE SOME SLIGHT
POPS FOR A WEAK UPPER DISTURBANCE TRAVERSING THE AREA DURING THE
DAY. TUESDAY WILL SEE A SIMILAR TEMPERATURE REGIME TO MONDAY WITH
EAST-NORTHEAST WINDS BUT SEVERAL DEGREES WARMER INLAND/UPPER 60S TO
LOW-MID 70S.
LOW CHANCES OF SHOWERS/STORMS ARE FAVORED TUESDAY NIGHT AND INTO
THURSDAY DUE TO POSSIBLE SW FLOW MID LEVEL DISTURBANCES AND
STRONG LL JET INCREASING INSTABILITY ALOFT. UPPER LEVEL RIDGING
OVER REGION WILL RESULT IN SUBSTANTIAL WARM UP FOR THE LATTER PART
OF THE WORK WEEK. 850/925 MB CLIMO SUPPORTS HIGHS AT LEAST UPPER
70S IF NOT INTO 80S ON WEDNESDAY AND THURSDAY...WITH EXCEPTION ON
WEDNESDAY BEING LIKELIHOOD OF SOUTHEAST ONSHORE FLOW ONTO IL
LAKEFRONT KEEPING THINGS COOLER THERE. QUESTION WITH LOW POPS ON
WEDNESDAY THURSDAY PERIOD IS HOW FAST SFC WARM FRONT LIFTS NORTH
ON WEDS AND WHETHER AREA WILL REMAIN PRIMARILY CAPPED WEDNESDAY
AND THURSDAY BEING IN WARM SECTOR. STEEP MIDLEVEL LAPSE RATES AND
SURGE OF HIGHER DEWPOINTS POSSIBLY INTO 60S WILL RESULT IN GOOD
INSTABILITY...BUT IN ABSENCE OF STRONG FORCING...CAPPING MAY BE
TOUGH TO OVERCOME UNTIL APPROACH OF LOW AND ASSOCIATED COLD FRONT
THURSDAY NIGHT OR FRIDAY.
SGIZZI/RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* PERIODIC WIDELY SCT LIGHT SHOWERS INTO EARLY THIS EVENING.
* PRIMARILY MVFR CIGS THROUGH MOST OF THE FORECAST
PERIOD...POTENTIAL FOR LOW MVFR CIGS OVERNIGHT.
* ANOTHER CHANCE OF SHOWERS BY FRIDAY EVENING.
KJB
//DISCUSSION...UPDATED 00Z...
THE UPPER LOW...WHICH HAS BEEN DOMINATE ACROSS THE CENTRAL CONUS
OVER THE PAST SEVERAL DAYS...IS NOW CENTERED ACROSS CENTRAL LOWER
MICHIGAN. THIS FEATURE WILL FINALLY LOSE ITS GRIP ON THE AREA BY
FRIDAY. UNTIL THEN...A FEW LINGERING SHOWERS CONTINUE TO ROTATE
AROUND THE WESTERN PERIPHERY OF THIS UPPER LOW...AND THESE SHOULD
CONTINUE AT TIMES OVER THE NEXT COUPLE HOURS BEFORE GRADUALLY
ENDING. CIGS LOOK TO REMAIN MVFR THROUGH AROUND MID DAY FRIDAY.
ALTHOUGH...THE CURRENT CIGS COULD COME DOWN A BIT LATER THIS
EVENING...POTENTIALLY DROPPING UNDER 1500 FEET AGL FOR A PERIOD
TONIGHT AS SOME LOWER CLOUDS...CURRENTLY ACROSS WISCONSIN AND
ADJACENT AREAS OF SOUTHEASTERN MN AND IOWA...TRY TO WORK THERE WAY
SOUTHWARD TOWARDS NORTHERN ILLINOIS. OTHERWISE...CIGS SHOULD
IMPROVE TO LOW END VFR BY FRIDAY AFTERNOON AS SLIGHTLY WARMER
CONDITIONS SHOULD ALLOW FOR SOME BETTER MIXING OUT OF THE LOWER
CLOUDS.
THERE WILL BE INCREASING CHANCES FOR SOME SHOWERS AGAIN...ESPECIALLY
FRIDAY EVENING...WHEN ANOTHER MID/UPPER LEVEL WEATHER DISTURBANCE
AND ASSOCIATED SURFACE FRONTAL BOUNDARY IS EXPECTED TO MOVE ACROSS
NORTHERN ILLINOIS.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM-HIGH FOR ALL FORECAST ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...VFR/WX NIL.
SUNDAY AND MONDAY...SLIGHT CHANCE SHRA DURG DAYTIME HRS...OTRW VFR/WX
NIL.
TUESDAY...VFR/WX NIL.
TUESDAY NIGHT-WEDNESDAY...CHANCE TSRA. MVFR/IFR CIGS/VIS POSSIBLE.
KJB
&&
.MARINE...
205 PM CDT
HEADLINES...WILL KEEP THE SMALL CRAFT ADVISORY GOING THROUGH EARLY
THIS EVENING...WITH WINDS DIMINISHING EARLY THIS EVENING.
LOW PRESSURE IS SHIFTING NORTHEAST AND WILL REACH ST JAMES BAY
TONIGHT. WINDS TURN WEST BEHIND THE LOW WITH THE HIGHEST GUSTS UP
TO 25 KT OVER THE SOUTHERN END OF THE LAKE. WINDS TURN SW AHEAD OF
THE NEXT TROUGH FRIDAY MORNING AND REMAIN WEST TO SOUTHWEST THROUGH
SATURDAY. HIGH PRESSURE BUILDS OVER THE REGION SUNDAY WITH WINDS
DIMINISHING AND BECOMING NORTHEAST TO EAST SUNDAY NIGHT. THE HIGH
REMAINS IN THE REGION THROUGH TUESDAY AND THEN SHIFTS EAST
WEDNESDAY. MEANWHILE A LOW FORMS OVER THE PLAINS LATE SUNDAY NIGHT
AND BEGINS TO SHIFT EAST THURSDAY. THE LOWS WARM FRONT WILL REMAIN
SOUTH OF THE LAKE WITH AN EXTENDED PERIOD OF EASTERLY WINDS EXPECTED
THROUGH AT LEAST MID NEXT WEEK. WINDS WILL TURN SOUTH AS THE LOW
LIFTS NORTH OVER THE LAKE.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
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WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
841 PM CDT Thu May 1 2014
.DISCUSSION...
ISSUED 841 PM CDT Thu May 1 2014
Deep mid-level vortex spinning through central lower Michigan this
evening and now showing signs of a quicker ENE progression
than has occurred in recent days. One of several vort spokes
around this large feature was passing through central IL this
evening and causing isolated showers and sprinkles which has been
centered near I-72 recently. This should continue to shift ESE and
dissipate over the next few hours as the vort max passes through.
Current forecast has situation handled well and will send out an
update towards midnight to remove evening shower wording.
25
&&
.AVIATION...
ISSUED 611 PM CDT Thu May 1 2014
Expansive area of stratocu with ceilings near MVFR/VFR threshold
continues to dominate the entire region. This will persist
overnight, with hi-res HRRR output suggesting northern TAF sites
will have a better chance of seeing periodic MVFR ceilings, while
VFR ceilings should be predominant farther south. This seems
reasonable given proximity to cold core upper low currently
spinning over the central Great Lakes. As this feature edges ever
so slowly to the northeast and in combination with diurnal heating
by mid-morning, all ceilings are expected to get well into VFR
range and continue through afternoon. WSW winds will decrease to
under 10 kts this evening, then increase again by mid morning with
periodic gusts up to 20 kts.
25
&&
.PREV DISCUSSION...
ISSUED 259 PM CDT Thu May 1 2014
The long wave trough that dominated the eastern States this week
will finally make some progress eastward tonight, with some
sunshine returning for Saturday. The damp and chilly airmass will be
gradually replaced with drier Plains air, which will warm under
the May sun into the 70s by early next week. We may even see some
low 80s on Wednesday and Thursday next week as trough carves out
across the Rockies and deeper warm air is drawn into the area.
The shift to a northwest flow late this weekend and next week will
shift the weather concerns to the track of any shortwaves in the
upper flow. Storm chances will increase mid to late next week as a
long wave trough arrives.
SHORT TERM...Tonight through Sunday.
Persistent clouds and spotty showers or sprinkles will linger
under the occluded low pressure system this evening, with a drying
trend after midnight as the upper low center finally shifts
northeast of IL. Low clouds and chilly air will remain in place,
as low temps dip into the upper 30s and low 40s.
The long wave trough axis will remain across IL from SW to NE on
Friday due to lingering energy in the base of the trough in
western Texas. A shortwave in central Saskatchewan this afternoon
will flow into the back side of that trough on Friday, reaching
our forecast area later Friday and Friday night. We added low
chance PoPs Friday evening as the best DPVA from the wave reaches
central IL on the nose of a 115kt 300 mb jet.
Saturday should bring a break in the rain chances along with some
increasing sunshine as heights begin to rise and gusty west winds
mix down some mid level dry air.
Some agreement has developed between the GFS/ECMWF/NAM/Canadian
about a narrow NW-SE channel of forcing for precip on Sunday
along a baroclinic zone. The chances will be mainly along and
north of I-74, with sprinkles 15-30 miles south of there. The fast
moving feature should advance SE of our area by Sunday night. Warm
air surging into at least the south half of our forecast area
should help boost high temps on Sunday in the lower 70s, with
around 60 under the clouds/precip in the north.
LONG TERM...Monday through Thursday.
A transition to a zonal flow across the Plains into the Heartland
will allow a continuation of the warming trend in central and
southeast Illinois. Warming will increase at the surface and
aloft, as 850 mb temps climb into the 12-16C range Mon-Tues.
Mixing those temps to the surface should yield highs in the low
70s Mon and mid-upper 70s on Tues.
Slight chances of showers and storms will return Tuesday night
through Wed night as a warm front develops from west to east
across Illinois and low level dewpoints climb into the lower 60s.
Surface low pressure lifting into Iowa on Thursday in concert with
a 500mb shortwave and an intensifying 300mb jet max has prompted
the use of chance PoPs northwest of the Illinois river on
Thursday, with slight chances down to I-70. Plenty of warm air
flowing into that system could help boost highs into the lower 80s
in a few spots south of Lincoln on Wed and Thursday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
616 PM CDT THU MAY 1 2014
.DISCUSSION...
308 PM CDT
MAIN FORECAST CHALLENGES/CONCERNS ARE WITH PRECIP TRENDS IN THE
NEAR TERM AND FRIDAY...AS WELL AS A SLOW TREND BACK TOWARDS MORE
NORMAL TEMPS THIS WEEKEND.
LATEST RADAR IMAGERY DEPICTING PERSISTENT SHOWERS TODAY STILL
ONGOING OVER MUCH OF THE CWA THIS AFTERNOON WITH A MORE SOLID AREA
CURRENTLY EXITING OVER FAR NORTHEAST ILLINOIS. THESE SHOWERS STILL
IN RESPONSE TO A LARGE/DYNAMIC UPPER LEVEL SYSTEM SLOWLY MOVING
EAST ACROSS THE UPPER MIDWEST AND GREAT LAKES REGION. OF
PARTICULAR INTEREST ARE A FAIRLY STOUT VORT LOBE WRAPPING AROUND
THE CENTER OF THIS SYSTEM...AND A MORE SHEARED OUT WAVE DROPPING
TO THE SOUTHEAST THROUGH EASTERN IOWA AND NORTHERN ILLINOIS. MODEL
GUIDANCE IN GOOD AGREEMENT WITH THIS SLOW MOVING SYSTEM TO OPEN
AND REALLY BEGIN KICKING OFF TO THE EAST...WHILE UPPER LEVEL
TROUGHING CONTINUES ACROSS THE CENTRAL CONUS. WHAT THIS WILL MEAN
IN THE NEAR TERM IS FOR ANY SHOWER DEVELOPMENT TO BEGIN A
DIMINISHING TREND THIS AFTERNOON INTO THE EVENING. AS THE SHEARED
OUT WAVE CONTINUES TO EXIT TO THE EAST/SOUTHEAST THIS
EVENING...COULD SEE SOME LINGERING SHOWERS ACROSS THE EAST AND
SOUTHEAST. SO HAVE LOW CHANCE POPS FOR MOST AREAS THIS
EVENING...KEEPING SLIGHTLY HIGHER POPS FROM PONTIAC NORTHEAST TO
GARY/VALPARAISO AND AREAS SOUTHEAST. DESPITE SOME ISOLATED
DEVELOPMENT MORE TOWARDS THE MIDNIGHT TIME FRAME...AN OVERALL DRY
PERIOD IS LIKELY DEFINITELY AFTER MIDNIGHT. COLDER TEMPS ALOFT
WILL TRY TO MODERATE SOME OVERNIGHT...BUT WITH STILL ANOTHER COLD
NIGHT EXPECTED WITH TEMPS AROUND 40.
PATTERN WILL REMAIN HIGHLY AMPLIFIED ON FRIDAY WITH MID/UPPER
LEVEL TROUGH STILL IN PLACE ACROSS THE CENTRAL CONUS...AND WITH
STRONG VORT MAX STILL DEPARTING TO THE EAST OF THE AREA. FRIDAY
WILL START OFF DRY AS BEST PVA WILL BE SITUATED AWAY FROM THE CWA
DESPITE UPPER LEVEL TROUGH OVERHEAD. NOT OVERLY EXCITED FOR TOO
MUCH WARMING ON FRIDAY AS CLOUD COVER WILL STILL BE IN PLACE AND
WITH A CONTINUED SLOW MODERATING TREND. SO DID BRING DOWN MAX
TEMPS A DEGREE OR TWO...WITH UPPER 50S APPEARING LIKELY ACROSS THE
CWA. UPPER LEVEL TROUGH WILL BEGIN SHIFTING TO THE EAST LATE IN
THE DAY BUT WITH NORTHWEST FLOW NOW ALLOWING A FAIRLY STOUT
SHORTWAVE TROUGH TO APPROACH FROM THE NORTHERN PLAINS AND UPPER
MIDWEST DURING THIS PERIOD. THIS APPROACHING MID LEVEL ENERGY AND
SURFACE TROUGH WILL ALLOW FOR SHOWER DEVELOPMENT TO ONCE AGAIN BE
ON THE INCREASE ACROSS THE CWA LATE IN THE DAY FRIDAY...INITIALLY
ACROSS THE FAR NORTHERN CWA. THEN AS BETTER FORCING SWINGS ACROSS
THE CWA DURING FRIDAY EVENING...SHOULD OBSERVE PRECIP SHIELD
LIKEWISE DO THE SAME. DID INCREASE POPS TO HIGH CHANCE INITIALLY
FOR THE NORTHERN HALF THE CWA THROUGH THE MID NIGHT TIME FRAME AND
THEN SHIFT THESE POPS OVER THE SOUTHEAST THIRD AFTER MIDNIGHT.
SHOWERS ARE ONLY LIKELY WITHOUT THUNDER DESPITE SOME STRONGER
FORCING MOVING OVERHEAD AND SOME GUIDANCE ADVERTISING SOME STEEPER
MID LEVEL LAPSE RATES ADVECTING ACROSS THE REGION. IF THUNDER WERE
TO OCCUR LATE FRIDAY...IT WOULD BE BRIEF/ISOLATED AND OCCUR
OUTSIDE OF THE CWA WELL TO THE NORTHWEST.
WITH THIS DEPARTING ENERGY FRIDAY NIGHT INTO SATURDAY...A DRYING
TREND IS LIKELY SATURDAY INTO SATURDAY NIGHT. WARMER TEMPS ALOFT
AND DRYING/CLEARING ON SATURDAY SHOULD FINALLY ALLOW FOR A RETURN
TO 60S ON SATURDAY...WITH UPPER 60S BECOMING LIKELY FOR THE
SOUTHERN HALF OF THE CWA.
RODRIGUEZ
LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...
HIGH PRESSURE CENTERED OVER THE SOUTHERN PART OF THE LAKE SUNDAY
EVENING WILL KEEP WINDS CALM AND OVERNIGHT TEMPERATURES FAIRLY COOL
MAINLY IN THE NORTHERN PART OF THE CWA. MONDAY AFTERNOON
TEMPERATURES WARM INTO THE LOWER AND MID/UPPER 60S INLAND DUE TO WAA
ALOFT FROM A DEVELOPING LOW PRESSURE IN THE CENTRAL PLAINS THAT WILL
SLOWLY TRACK EAST THROUGH LATE IN THE WORK WEEK. PERSISTENT ONSHORE
FLOW WILL KEEP THE LAKEFRONT MUCH COOLER ON MONDAY. HAVE SOME SLIGHT
POPS FOR A WEAK UPPER DISTURBANCE TRAVERSING THE AREA DURING THE
DAY. TUESDAY WILL SEE A SIMILAR TEMPERATURE REGIME TO MONDAY WITH
EAST-NORTHEAST WINDS BUT SEVERAL DEGREES WARMER INLAND/UPPER 60S TO
LOW-MID 70S.
LOW CHANCES OF SHOWERS/STORMS ARE FAVORED TUESDAY NIGHT AND INTO
THURSDAY DUE TO POSSIBLE SW FLOW MID LEVEL DISTURBANCES AND
STRONG LL JET INCREASING INSTABILITY ALOFT. UPPER LEVEL RIDGING
OVER REGION WILL RESULT IN SUBSTANTIAL WARM UP FOR THE LATTER PART
OF THE WORK WEEK. 850/925 MB CLIMO SUPPORTS HIGHS AT LEAST UPPER
70S IF NOT INTO 80S ON WEDNESDAY AND THURSDAY...WITH EXCEPTION ON
WEDNESDAY BEING LIKELIHOOD OF SOUTHEAST ONSHORE FLOW ONTO IL
LAKEFRONT KEEPING THINGS COOLER THERE. QUESTION WITH LOW POPS ON
WEDNESDAY THURSDAY PERIOD IS HOW FAST SFC WARM FRONT LIFTS NORTH
ON WEDS AND WHETHER AREA WILL REMAIN PRIMARILY CAPPED WEDNESDAY
AND THURSDAY BEING IN WARM SECTOR. STEEP MIDLEVEL LAPSE RATES AND
SURGE OF HIGHER DEWPOINTS POSSIBLY INTO 60S WILL RESULT IN GOOD
INSTABILITY...BUT IN ABSENCE OF STRONG FORCING...CAPPING MAY BE
TOUGH TO OVERCOME UNTIL APPROACH OF LOW AND ASSOCIATED COLD FRONT
THURSDAY NIGHT OR FRIDAY.
SGIZZI/RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* PERIODIC WIDELY SCT LIGHT SHOWERS INTO EARLY THIS EVENING.
* PRIMARILY MVFR CIGS THROUGH MOST OF THE FORECAST
PERIOD...POTENTIAL FOR LOW MVFR CIGS OVERNIGHT.
* ANOTHER CHANCE OF SHOWERS BY FRIDAY EVENING.
KJB
//DISCUSSION...UPDATED 00Z...
THE UPPER LOW...WHICH HAS BEEN DOMINATE ACROSS THE CENTRAL CONUS
OVER THE PAST SEVERAL DAYS...IS NOW CENTERED ACROSS CENTRAL LOWER
MICHIGAN. THIS FEATURE WILL FINALLY LOSE ITS GRIP ON THE AREA BY
FRIDAY. UNTIL THEN...A FEW LINGERING SHOWERS CONTINUE TO ROTATE
AROUND THE WESTERN PERIPHERY OF THIS UPPER LOW...AND THESE SHOULD
CONTINUE AT TIMES OVER THE NEXT COUPLE HOURS BEFORE GRADUALLY
ENDING. CIGS LOOK TO REMAIN MVFR THROUGH AROUND MID DAY FRIDAY.
ALTHOUGH...THE CURRENT CIGS COULD COME DOWN A BIT LATER THIS
EVENING...POTENTIALLY DROPPING UNDER 1500 FEET AGL FOR A PERIOD
TONIGHT AS SOME LOWER CLOUDS...CURRENTLY ACROSS WISCONSIN AND
ADJACENT AREAS OF SOUTHEASTERN MN AND IOWA...TRY TO WORK THERE WAY
SOUTHWARD TOWARDS NORTHERN ILLINOIS. OTHERWISE...CIGS SHOULD
IMPROVE TO LOW END VFR BY FRIDAY AFTERNOON AS SLIGHTLY WARMER
CONDITIONS SHOULD ALLOW FOR SOME BETTER MIXING OUT OF THE LOWER
CLOUDS.
THERE WILL BE INCREASING CHANCES FOR SOME SHOWERS AGAIN...ESPECIALLY
FRIDAY EVENING...WHEN ANOTHER MID/UPPER LEVEL WEATHER DISTURBANCE
AND ASSOCIATED SURFACE FRONTAL BOUNDARY IS EXPECTED TO MOVE ACROSS
NORTHERN ILLINOIS.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM-HIGH FOR ALL FORECAST ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...VFR/WX NIL.
SUNDAY AND MONDAY...SLIGHT CHANCE SHRA DURG DAYTIME HRS...OTRW VFR/WX
NIL.
TUESDAY...VFR/WX NIL.
TUESDAY NIGHT-WEDNESDAY...CHANCE TSRA. MVFR/IFR CIGS/VIS POSSIBLE.
KJB
&&
.MARINE...
205 PM CDT
HEADLINES...WILL KEEP THE SMALL CRAFT ADVISORY GOING THROUGH EARLY
THIS EVENING...WITH WINDS DIMINISHING EARLY THIS EVENING.
LOW PRESSURE IS SHIFTING NORTHEAST AND WILL REACH ST JAMES BAY
TONIGHT. WINDS TURN WEST BEHIND THE LOW WITH THE HIGHEST GUSTS UP
TO 25 KT OVER THE SOUTHERN END OF THE LAKE. WINDS TURN SW AHEAD OF
THE NEXT TROUGH FRIDAY MORNING AND REMAIN WEST TO SOUTHWEST THROUGH
SATURDAY. HIGH PRESSURE BUILDS OVER THE REGION SUNDAY WITH WINDS
DIMINISHING AND BECOMING NORTHEAST TO EAST SUNDAY NIGHT. THE HIGH
REMAINS IN THE REGION THROUGH TUESDAY AND THEN SHIFTS EAST
WEDNESDAY. MEANWHILE A LOW FORMS OVER THE PLAINS LATE SUNDAY NIGHT
AND BEGINS TO SHIFT EAST THURSDAY. THE LOWS WARM FRONT WILL REMAIN
SOUTH OF THE LAKE WITH AN EXTENDED PERIOD OF EASTERLY WINDS EXPECTED
THROUGH AT LEAST MID NEXT WEEK. WINDS WILL TURN SOUTH AS THE LOW
LIFTS NORTH OVER THE LAKE.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
611 PM CDT Thu May 1 2014
.DISCUSSION...
ISSUED 259 PM CDT Thu May 1 2014
The long wave trough that dominated the eastern States this week
will finally make some progress eastward tonight, with some
sunshine returning for Saturday. The damp and chilly airmass will be
gradually replaced with drier Plains air, which will warm under
the May sun into the 70s by early next week. We may even see some
low 80s on Wednesday and Thursday next week as trough carves out
across the Rockies and deeper warm air is drawn into the area.
The shift to a northwest flow late this weekend and next week will
shift the weather concerns to the track of any shortwaves in the
upper flow. Storm chances will increase mid to late next week as a
long wave trough arrives.
SHORT TERM...Tonight through Sunday.
Persistent clouds and spotty showers or sprinkles will linger
under the occluded low pressure system this evening, with a drying
trend after midnight as the upper low center finally shifts
northeast of IL. Low clouds and chilly air will remain in place,
as low temps dip into the upper 30s and low 40s.
The long wave trough axis will remain across IL from SW to NE on
Friday due to lingering energy in the base of the trough in
western Texas. A shortwave in central Saskatchewan this afternoon
will flow into the back side of that trough on Friday, reaching
our forecast area later Friday and Friday night. We added low
chance PoPs Friday evening as the best DPVA from the wave reaches
central IL on the nose of a 115kt 300 mb jet.
Saturday should bring a break in the rain chances along with some
increasing sunshine as heights begin to rise and gusty west winds
mix down some mid level dry air.
Some agreement has developed between the GFS/ECMWF/NAM/Canadian
about a narrow NW-SE channel of forcing for precip on Sunday
along a baroclinic zone. The chances will be mainly along and
north of I-74, with sprinkles 15-30 miles south of there. The fast
moving feature should advance SE of our area by Sunday night. Warm
air surging into at least the south half of our forecast area
should help boost high temps on Sunday in the lower 70s, with
around 60 under the clouds/precip in the north.
LONG TERM...Monday through Thursday.
A transition to a zonal flow across the Plains into the Heartland
will allow a continuation of the warming trend in central and
southeast Illinois. Warming will increase at the surface and
aloft, as 850 mb temps climb into the 12-16C range Mon-Tues.
Mixing those temps to the surface should yield highs in the low
70s Mon and mid-upper 70s on Tues.
Slight chances of showers and storms will return Tuesday night
through Wed night as a warm front develops from west to east
across Illinois and low level dewpoints climb into the lower 60s.
Surface low pressure lifting into Iowa on Thursday in concert with
a 500mb shortwave and an intensifying 300mb jet max has prompted
the use of chance PoPs northwest of the Illinois river on
Thursday, with slight chances down to I-70. Plenty of warm air
flowing into that system could help boost highs into the lower 80s
in a few spots south of Lincoln on Wed and Thursday.
&&
.AVIATION...
ISSUED 611 PM CDT Thu May 1 2014
Expansive area of stratocu with ceilings near MVFR/VFR threshold
continues to dominate the entire region. This will persist
overnight, with hi-res HRRR output suggesting northern TAF sites
will have a better chance of seeing periodic MVFR ceilings, while
VFR ceilings should be predominant farther south. This seems
reasonable given proximity to cold core upper low currently
spinning over the central Great Lakes. As this feature edges ever
so slowly to the northeast and in combination with diurnal heating
by mid-morning, all ceilings are expected to get well into VFR
range and continue through afternoon. WSW winds will decrease to
under 10 kts this evening, then increase again by mid morning with
periodic gusts up to 20 kts.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
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 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
NWS GRAY ME
1024 PM EDT THU MAY 1 2014
.SYNOPSIS...
AN UPPER LEVEL SYSTEM BRINGS A CHANCE OF SHOWERS TO THE REGION
OVER THE WEEKEND. LOW PRESSURE AND A TRAILING COLD FRONT WILL
APPROACH FROM THE WEST SATURDAY THEN CROSS THE REGION SUNDAY
BRINGING AN INCREASING CHANCE OF RAIN. THE SYSTEM STALLS OVER THE
MARITIMES ON MONDAY PRODUCING ISOLATED TO SCATTERED SHOWERS ACROSS
THE REGION. HIGH PRESSURE SLOWLY BUILDS IN FROM THE WEST TUESDAY
AND WEDNESDAY WITH IMPROVING WEATHER.
&&
.NEAR TERM /TONIGHT/...
1030PM UPDATE...
LINE OF SHOWERS AND EMBEDDED THUNDERSTORM IS MOVING TO THE COAST
NOW. HAVE ADJUSTED POP TO BETTER REFINE AREAS MOST LIKELY TO BE
AFFECTED BY THIS AS WELL AS SHOWERS OVER THE MOUNTAINS. THE
THUNDER NEAR PORTLAND SHOULD BE OVER WITHIN AN HOUR OR SO AS IT
MOVES OVER THE OCEAN. ALSO HAVE REFINED AREAS EXPECTED TO SEE FOG
AS MARINE CLOUDS/FOG HAVE MOVED ONSHORE IN SOUTHEAST NEW HAMPSHIRE
BUT HAVE NOT QUITE REACHED MOST OF THE MAINE COASTLINE YET. THIS
FOG MAY DISSIPATE LATER IN THE NIGHT AS WINDS SHIFT TO THE WEST.
8PM UPDATE...
HAVE UPDATED THE GRIDS BASED ON CURRENT CONDITIONS. SHOWERS
CONTINUE TO MARCH ACROSS FORECAST AREA. LATEST HRRR RUN DEPICTS
SHOWERS MOVING ACROSS THE REGION...BUT THE TIMING IS OFFSET BY A
FEW HOURS...BRINGING IN THE PRECIPITATION MUCH LATER TONIGHT WHICH
APPEARS TO BE TOO SLOW.
ADJUSTED DEW POINT AND CLOUD FORECAST...ESPECIALLY FOR THE FOG
ALONG THE IMMEDIATE COASTLINE THIS EVENING. REST OF THE FORECAST
WILL REMAIN RELATIVELY UNCHANGED.
445PM UPDATE...
HAVE MADE SOME UPDATES TO ACCOUNT FOR OBSERVED CLOUD COVER AND
PRECIPITATION TRENDS. SHOULD SEE A BROKEN LINE OF SHOWERS ENTER
NEW HAMPSHIRE AROUND 7 OR 8 PM. HRRR INDICATES THIS LINE WILL
CONTINUE TO BREAK UP AS IT MOVES ACROSS NEW HAMPSHIRE AND MAINE
THIS EVENING. STILL A CHANCE OF FOG LATER THIS EVENING.
ORIGINAL DISCUSSION...
JUST A FEW SHOWERS REMAIN OVER EASTERN MAINE ASSOCIATED WITH THE
WARM FRONT AS IT LIFTS THROUGH DOWNEAST MAINE AND TOWARDS THE
CANADIAN MARITIMES. FINALLY SEEING SOME BREAKS IN CLOUDS OVER NH
AND WESTERN MAINE ALLOWING TEMPERATURES TO REACH THE LOWER 60S IN
A FEW SPOTS. STRATUS AND FOG WILL CREEP BACK AFTER DARK ONCE AGAIN
HOWEVER AS INVERSION DEVELOPS ONCE AGAIN. TEMPERATURES SHOULD BE
PRETTY WELL INSULATED IN THE LOWER TO MID 40S.
MODELS ARE STILL SHOWING MORE SHOWERS TONIGHT AND OVERNIGHT AS
ADDITIONAL UPPER LEVEL SUPPORT MOVES THROUGH. ONLY EXPECTING A
TENTH OR SO OF ADDITIONAL QPF WITH THIS ACTIVITY WITH THE
MOUNTAINS BEING THE BEST BET.
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
FAST MOVING SHORT WAVE WILL CROSS THE REGION TOMORROW IN SW FLOW
ALOFT. THIS WILL KEEP CLOUDS AND SOME SHOWERS IN THE AREA...
HOWEVER AM EXPECTING ANY VERY LOW CLOUDS TO LIFT AS WEST WINDS
BECOME GUSTY AFTER DAYBREAK. WARM 850MB TEMPERATURES AND WSW WINDS
WILL WARM TEMPERATURES INTO THE 50S AND 60S AND EXPECT THE
WARMEST READINGS IN SOUTHERN SECTIONS. TOMORROW NIGHT WE WILL SEE
CLEARING ESPECIALLY ALONG THE COASTAL PLAIN WITH TEMPERATURES
DROPPING INTO THE 30S AND 40S.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
A WARM DAY SATURDAY WITH A SW FLOW IN ADVANCE OF THE UPPER TROUGH
OVER THE GREAT LAKES THAT DEEPENS AND EVOLVES INTO A CLOSED
UPPER LOW SYSTEM AS IT TRACKS EAST TOWARD NEW ENGLAND LATE
SATURDAY INTO SUNDAY. THE UPPER LOW SETTLES OVER NEW ENGLAND BY
LATE SUNDAY AND INTO MONDAY WITH A COLD POOL OF AIR ALOFT WITH A
CYCLONIC FLOW OVER THE AREA. THIS ALL MEANS SATURDAY WILL BE WARM
WITH TEMPERATURES WELL INTO THE 60S BUT A RETURN TO MUCH COOLER
TEMPERATURES FOR SUNDAY AND EARLY NEXT WEEK. AN UNSETTLED PATTERN
CAN BE EXPECTED OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
BY TUESDAY A DRY NW FLOW DEVELOPS AND A SLOW RETURN TO WARMER
TEMPERATURES WITH FAIR AMOUNT OF SUNSHINE THAT WILL CONTINUE THRU
MIDWEEK AS A SURFACE/UPPER RIDGE BUILDS EAST ACROSS THE NORTHEASTERN
UNITED STATES.
USED A BLEND OF THE MAV/MET GUIDANCE FOR 4TH/5TH PERIODS AND THEN
STAYED CLOSE TO THE SUPERBLEND FOR POPS AND TEMPERATURES THRU THE
OUTLOOK PERIOD.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...CURRENT CLEARING WILL LAST UNTIL DARK AND AS SOON AS
INVERSION IS ESTABLISHED AGAIN EXPECT 1/4SM/VV001 AT ALL
TERMINALS. MVFR TO LIFR CONDITIONS WILL STAY OR DROP TO LIFR
WITH PLENTY OF LOW LEVEL/GROUND MOISTURE AVAILABLE FOR STRATUS AND
FOG TONIGHT. IMPROVEMENT TO VFR WILL OCCUR AROUND 10-12Z WITH AN
INCREASE IN GUSTY WEST WINDS.
LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...VFR CONDITIONS SATURDAY
LOWERING TO MVFR/IFR LATE SATURDAY THRU MONDAY. CONDITIONS IMPROVE
TO VFR TUESDAY.
&&
.MARINE...
SHORT TERM...SMALL CRAFT ADVISORY WAS CONVERTED TO JUST ADVISORY
FOR SEAS AS WIND GUSTS HAVE DIMINISHED. SOUTHERN OUTER ZONE WILL
DROP BELOW CRITERIA AFTER DAYBREAK FRIDAY AND WILL BE ALLOWED TO
DROP OUT OF THE ADVISORY WHILE THE OTHER LOCATIONS CONTINUE TO SEE
HIGH SEAS.
LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...WINDS AND SEAS MOSTLY
BELOW SCA LEVELS UNTIL NW WIND GUSTS AND SEAS REACH MINIMAL SCA
LEVELS OVER THE OPEN WATERS SUNDAY NIGHT AND MONDAY BEHIND THE
DEPARTING AND STRENGTHENING LOW PRESSURE SYSTEM.
&&
.FIRE WEATHER...
UNSETTLED PERIOD SHOULD KEEP FIRE WEATHER CONCERNS LOW. WILL BE
WARM THIS FRIDAY IN SOUTHERN AREAS WITH A SW WIND...BUT EXPECT
MINIMUM RH VALUES ABOVE 35% ALL AREAS. EXPECT MORE RAIN TONIGHT
AND TOMORROW.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM EDT FRIDAY
FOR ANZ151-153-154.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 PM EDT FRIDAY
FOR ANZ150-152.
&&
$$
NEAR TERM UPDATE... KIMBLE
SHORT TERM... HANES
LONG TERM... MARINE
AREA FORECAST DISCUSSION
NWS GRAY ME
810 PM EDT THU MAY 1 2014
.SYNOPSIS...
AN UPPER LEVEL SYSTEM BRINGS A CHANCE OF SHOWERS TO THE REGION
OVER THE WEEKEND. LOW PRESSURE AND A TRAILING COLD FRONT WILL
APPROACH FROM THE WEST SATURDAY THEN CROSS THE REGION SUNDAY
BRINGING AN INCREASING CHANCE OF RAIN. THE SYSTEM STALLS OVER THE
MARITIMES ON MONDAY PRODUCING ISOLATED TO SCATTERED SHOWERS ACROSS
THE REGION. HIGH PRESSURE SLOWLY BUILDS IN FROM THE WEST TUESDAY
AND WEDNESDAY WITH IMPROVING WEATHER.
&&
.NEAR TERM /THROUGH FRIDAY/...
0000Z UPDATE...
HAVE UPDATED THE GRIDS BASED ON CURRENT CONDITIONS. SHOWERS
CONTINUE TO MARCH ACROSS FORECAST AREA. LATEST HRRR RUN DEPICTS
SHOWERS MOVING ACROSS THE REGION...BUT THE TIMING IS OFFSET BY A
FEW HOURS...BRINGING IN THE PCPN MUCH LATER TONIGHT WHICH APPEARS
TO BE TOO SLOW.
ADJUSTED DEW POINT AND CLOUD FORECAST...ESPECIALLY FOR THE FOG
ALONG THE IMMEDIATE COASTLINE THIS EVENING. REST OF THE FORECAST
WILL REMAIN RELATIVELY UNCHANGED.
PREV DISC...
445PM UPDATE...
HAVE MADE SOME UPDATES TO ACCOUNT FOR OBSERVED CLOUD COVER AND
PRECIPITATION TRENDS. SHOULD SEE A BROKEN LINE OF SHOWERS ENTER
NEW HAMPSHIRE AROUND 7 OR 8 PM. HRRR INDICATES THIS LINE WILL
CONTINUE TO BREAK UP AS IT MOVES ACROSS NEW HAMPSHIRE AND MAINE
THIS EVENING. STILL A CHANCE OF FOG LATER THIS EVENING.
ORIGINAL DISCUSSION...
JUST A FEW SHOWERS REMAIN OVER EASTERN MAINE ASSOCIATED WITH THE
WARM FRONT AS IT LIFTS THROUGH DOWNEAST MAINE AND TOWARDS THE
CANADIAN MARITIMES. FINALLY SEEING SOME BREAKS IN CLOUDS OVER NH
AND WESTERN MAINE ALLOWING TEMPERATURES TO REACH THE LOWER 60S IN
A FEW SPOTS. STRATUS AND FOG WILL CREEP BACK AFTER DARK ONCE AGAIN
HOWEVER AS INVERSION DEVELOPS ONCE AGAIN. TEMPERATURES SHOULD BE
PRETTY WELL INSULATED IN THE LOWER TO MID 40S.
MODELS ARE STILL SHOWING MORE SHOWERS TONIGHT AND OVERNIGHT AS
ADDITIONAL UPPER LEVEL SUPPORT MOVES THROUGH. ONLY EXPECTING A
TENTH OR SO OF ADDITIONAL QPF WITH THIS ACTIVITY WITH THE
MOUNTAINS BEING THE BEST BET.
&&
.SHORT TERM /FRIDAY NIGHT/...
FAST MOVING SHORT WAVE WILL CROSS THE REGION TOMORROW IN SW FLOW
ALOFT. THIS WILL KEEP CLOUDS AND SOME SHOWERS IN THE AREA...
HOWEVER AM EXPECTING ANY VERY LOW CLOUDS TO LIFT AS WEST WINDS
BECOME GUSTY AFTER DAYBREAK. WARM 850MB TEMPERATURES AND WSW WINDS
WILL WARM TEMPERATURES INTO THE 50S AND 60S AND EXPECT THE
WARMEST READINGS IN SOUTHERN SECTIONS. TOMORROW NIGHT WE WILL SEE
CLEARING ESPECIALLY ALONG THE COASTAL PLAIN WITH TEMPERATURES
DROPPING INTO THE 30S AND 40S.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
A WARM DAY SATURDAY WITH A SW FLOW IN ADVANCE OF THE UPPER TROUGH
OVER THE GREAT LAKES THAT DEEPENS AND EVOLVES INTO A CLOSED
UPPER LOW SYSTEM AS IT TRACKS EAST TOWARD NEW ENGLAND LATE
SATURDAY INTO SUNDAY. THE UPPER LOW SETTLES OVER NEW ENGLAND BY
LATE SUNDAY AND INTO MONDAY WITH A COLD POOL OF AIR ALOFT WITH A
CYCLONIC FLOW OVER THE AREA. THIS ALL MEANS SATURDAY WILL BE WARM
WITH TEMPERATURES WELL INTO THE 60S BUT A RETURN TO MUCH COOLER
TEMPERATURES FOR SUNDAY AND EARLY NEXT WEEK. AN UNSETTLED PATTERN
CAN BE EXPECTED OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
BY TUESDAY A DRY NW FLOW DEVELOPS AND A SLOW RETURN TO WARMER
TEMPERATURES WITH FAIR AMOUNT OF SUNSHINE THAT WILL CONTINUE THRU
MIDWEEK AS A SURFACE/UPPER RIDGE BUILDS EAST ACROSS THE NORTHEASTERN
UNITED STATES.
USED A BLEND OF THE MAV/MET GUIDANCE FOR 4TH/5TH PERIODS AND THEN
STAYED CLOSE TO THE SUPERBLEND FOR POPS AND TEMPERATURES THRU THE
OUTLOOK PERIOD.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...CURRENT CLEARING WILL LAST UNTIL DARK AND AS SOON AS
INVERSION IS ESTABLISHED AGAIN EXPECT 1/4SM/VV001 AT ALL
TERMINALS. MVFR TO LIFR CONDITIONS WILL STAY OR DROP TO LIFR
WITH PLENTY OF LOW LEVEL/GROUND MOISTURE AVAILABLE FOR STRATUS AND
FOG TONIGHT. IMPROVEMENT TO VFR WILL OCCUR AROUND 10-12Z WITH AN
INCREASE IN GUSTY WEST WINDS.
LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...VFR CONDITIONS SATURDAY
LOWERING TO MVFR/IFR LATE SATURDAY THRU MONDAY. CONDITIONS IMPROVE
TO VFR TUESDAY.
&&
.MARINE...
SHORT TERM...SMALL CRAFT ADVISORY WAS CONVERTED TO JUST ADVISORY
FOR SEAS AS WIND GUSTS HAVE DIMINISHED. SOUTHERN OUTER ZONE WILL
DROP BELOW CRITERIA AFTER DAYBREAK FRIDAY AND WILL BE ALLOWED TO
DROP OUT OF THE ADVISORY WHILE THE OTHER LOCATIONS CONTINUE TO SEE
HIGH SEAS.
LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...WINDS AND SEAS MOSTLY
BELOW SCA LEVELS UNTIL NW WIND GUSTS AND SEAS REACH MINIMAL SCA
LEVELS OVER THE OPEN WATERS SUNDAY NIGHT AND MONDAY BEHIND THE
DEPARTING AND STRENGTHENING LOW PRESSURE SYSTEM.
&&
.FIRE WEATHER...
UNSETTLED PERIOD SHOULD KEEP FIRE WEATHER CONCERNS LOW. WILL BE
WARM THIS FRIDAY IN SOUTHERN AREAS WITH A SW WIND...BUT EXPECT
MINIMUM RH VALUES ABOVE 35% ALL AREAS. EXPECT MORE RAIN TONIGHT
AND TOMORROW.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM EDT FRIDAY
FOR ANZ151-153-154.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 PM EDT FRIDAY
FOR ANZ150-152.
&&
$$
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 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 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 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 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 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 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 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 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 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 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 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
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 GREEN BAY WI
1040 PM CDT THU MAY 1 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 216 PM CDT THU MAY 1 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN UPPER LEVEL
LOW PRESSURE SYSTEM MOVING ACROSS CENTRAL LAKE MICHIGAN EARLY THIS
AFTERNOON. LAGGING BEHIND THIS UPPER LOW IS A SURFACE TROUGH WHICH
EXTENDS ACROSS NORTHEAST AND CENTRAL WISCONSIN. MOST THE
PRECIPITATION SO FAR TODAY HAS OCCURRED OVER NORTHEAST/NORTH-CENTRAL
AND CENTRAL WISCONSIN THOUGH SHOWERS ARE STARTING TO REDEVELOP
ACROSS THE FOX VALLEY AND EAST-CENTRAL WISCONSIN LAKE SHORE.
SHOWERS AND DRIZZLE EXTEND ALL THE WAY TO THE MINNESOTA BORDER...SO
WILL TAKE AWHILE FOR DRY CONDITIONS TO RESUME. WITH SHOWERS
REDEVELOPING...WILL HAVE LIKELY SHOWERS FOR THE WHOLE FORECAST AREA
THROUGH EARLY THIS EVENING. CLEARING SKIES DO NOT BEGIN UNTIL YOU
REACH NORTH DAKOTA AND MANITOBA...BUT THE NEXT SHORTWAVE IS ALREADY
MOVING INTO THIS AREA...AND POISED TO MOVE INTO THE REGION
TOMORROW. PRECIP CHANCES REMAIN THE MAIN FORECAST CONCERN IN THE
SHORT TERM.
TONIGHT...THE PESKY UPPER LOW WILL FINALLY EXIT TO THE EASTERN GREAT
LAKES TONIGHT THANKS TO KICKER ENERGY DIVING SOUTHEAST ACROSS
SOUTH-CENTRAL CANADA. WITH SHOWERS EXTENDING BACK TO THE MINNESOTA
BORDER AND A SURFACE TROUGH STILL TO MOVE THROUGH THIS
EVENING...PROGGED SOUNDINGS REMAIN SUFFICIENTLY SATURATED TO INCLUDE
SHOWERS IN THE FORECAST THROUGH MIDNIGHT. DRYING ALOFT DOES
PROGRESSIVELY OCCUR AFTER MIDNIGHT SO THINK WE COULD FINALLY SEE A
DRY PERIOD TAKE PLACE LATE TONIGHT. SKIES SHOULD REMAIN MOSTLY CLOUDY
THROUGH THE NIGHT HOWEVER...WITH A LOW OVERCAST DECK GRADUALLY
RISING AFTER MIDNIGHT. LOWS IN THE MID 30S TO LOW 40S.
FRIDAY...DECENT SHORTWAVE ENERGY WILL CONTINUE TO MOVE SOUTHEAST
INTO THE NORTHERN MISSISSIPPI VALLEY BY 18Z AND CENTRAL WISCONSIN BY
00Z SATURDAY. LARGE SCALE FORCING IN THE FORM OF DPVA AND UPPER
DIVERGENCE IN THE LEFT FRONT QUAD OF A JET STREAK WILL INCREASE
DURING THE AFTERNOON. SLOWED DOWN TIMING OF PRECIP CHANCES A LITTLE
AND ONLY BRING A SMALL CHANCE OF SHOWERS INTO WESTERN SECTIONS OF
THE CWA PRIOR TO 18Z. THEN WILL INCREASE POPS INTO THE LIKELY RANGE
EAST OF THE LAKE SHORE BY MID AFTERNOON. LOOKING AT MODIFIED
SOUNDINGS FOR TOMORROW AFTERNOON...ML CAPES ARE A LITTLE HIGHER THAN
DEPICTED YESTERDAY...BUT STILL STRUGGLE TO SQUEAK OUT 50-75 J/KG OF
INSTABILITY. INSTABILITY IS BETTER OVER SOUTHWEST WISCONSIN
COMPARED TO OUR REGION...SO THINK WILL LEAVE OUT A MENTION OF
THUNDER. HIGH TEMPS SHOULD RISE INTO THE LOW TO MID 50S BEFORE THE
RAIN SHOWERS ARRIVE.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 216 PM CDT THU MAY 1 2014
SIGNIFICANT PATTERN CHANGE DURING THE PERIOD AS UPPER FLOW ACROSS
THE CENTRAL U.S. GOES FROM NW TO SW.
EARLY IN PERIOD...STILL DEALING WITH UPPER LOW OVER SE CANADA AND
ONE MORE WEAK DISTURBANCE. ON SATURDAY...MARGINAL INSTABILITY
SHOULD BE SUFFICIENT FOR MID-DAY OR AFTERNOON SHOWERS. BRIEF DRY
PERIOD THEN AS SFC RIDGE MOVES ACROSS STATE.
NEXT SYSTEM MOVES TOWARD REGION MIDWEEK. GFS AND ECMWF IN GENERAL
AGREEMENT ON MOVEMENT AND LOCATION...THOUGH GFS A BIT FASTER.
WARM FRONT MAKES NORTH PUSH INTO STATE ON WED. ELEVATED CONVECTION
EXPECTED AS RIPPLES IN SW FLOW MOVE OVER LOW-LEVEL CONVERGENCE
ALONG FRONT. FRONTAL POSITION WILL HAVE SIGNIFICANT IMPACT ON
TEMPS...ESP NEXT THURS. WILL SIDE WITH SLOWER ECMWF FOR NOW...AS
COLD LAKE MICH SHOULD SLOW DOWN NORTH PUSH...AT LEAST INITIALLY.
TEMP FORECAST FOR THE MAJORITY OF THE LONG TERM A BLEND OF BEST
PERFORMING GUIDANCE.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1039 PM CDT THU MAY 1 2014
WRAP AROUND MOISTURE AROUND AN UPPER LOW OVER LOWER MICHIGAN LATE
TONIGHT WILL CONTINUE TO PRODUCE MAINLY MVFR CONDTION OVERNIGHT.
CONDITIONS WILL LIKELY PERSIST FRIDAY MORNING BEFORE MIXING AND
LIFT DUE TO A SHORT WAVE APPROACHING FROM THE NORTHERN PLAINS
IMPROVES CIGS. SCATTERED SHOWERS ARE EXPECTED FOR THE AFTERNOON
ALONG WITH AREAS OF MVFR CIGS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......JKL
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
635 PM CDT THU MAY 1 2014
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 216 PM CDT THU MAY 1 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN UPPER LEVEL
LOW PRESSURE SYSTEM MOVING ACROSS CENTRAL LAKE MICHIGAN EARLY THIS
AFTERNOON. LAGGING BEHIND THIS UPPER LOW IS A SURFACE TROUGH WHICH
EXTENDS ACROSS NORTHEAST AND CENTRAL WISCONSIN. MOST THE
PRECIPITATION SO FAR TODAY HAS OCCURRED OVER NORTHEAST/NORTH-CENTRAL
AND CENTRAL WISCONSIN THOUGH SHOWERS ARE STARTING TO REDEVELOP
ACROSS THE FOX VALLEY AND EAST-CENTRAL WISCONSIN LAKE SHORE.
SHOWERS AND DRIZZLE EXTEND ALL THE WAY TO THE MINNESOTA BORDER...SO
WILL TAKE AWHILE FOR DRY CONDITIONS TO RESUME. WITH SHOWERS
REDEVELOPING...WILL HAVE LIKELY SHOWERS FOR THE WHOLE FORECAST AREA
THROUGH EARLY THIS EVENING. CLEARING SKIES DO NOT BEGIN UNTIL YOU
REACH NORTH DAKOTA AND MANITOBA...BUT THE NEXT SHORTWAVE IS ALREADY
MOVING INTO THIS AREA...AND POISED TO MOVE INTO THE REGION
TOMORROW. PRECIP CHANCES REMAIN THE MAIN FORECAST CONCERN IN THE
SHORT TERM.
TONIGHT...THE PESKY UPPER LOW WILL FINALLY EXIT TO THE EASTERN GREAT
LAKES TONIGHT THANKS TO KICKER ENERGY DIVING SOUTHEAST ACROSS
SOUTH-CENTRAL CANADA. WITH SHOWERS EXTENDING BACK TO THE MINNESOTA
BORDER AND A SURFACE TROUGH STILL TO MOVE THROUGH THIS
EVENING...PROGGED SOUNDINGS REMAIN SUFFICIENTLY SATURATED TO INCLUDE
SHOWERS IN THE FORECAST THROUGH MIDNIGHT. DRYING ALOFT DOES
PROGRESSIVELY OCCUR AFTER MIDNIGHT SO THINK WE COULD FINALLY SEE A
DRY PERIOD TAKE PLACE LATE TONIGHT. SKIES SHOULD REMAIN MOSTLY CLOUDY
THROUGH THE NIGHT HOWEVER...WITH A LOW OVERCAST DECK GRADUALLY
RISING AFTER MIDNIGHT. LOWS IN THE MID 30S TO LOW 40S.
FRIDAY...DECENT SHORTWAVE ENERGY WILL CONTINUE TO MOVE SOUTHEAST
INTO THE NORTHERN MISSISSIPPI VALLEY BY 18Z AND CENTRAL WISCONSIN BY
00Z SATURDAY. LARGE SCALE FORCING IN THE FORM OF DPVA AND UPPER
DIVERGENCE IN THE LEFT FRONT QUAD OF A JET STREAK WILL INCREASE
DURING THE AFTERNOON. SLOWED DOWN TIMING OF PRECIP CHANCES A LITTLE
AND ONLY BRING A SMALL CHANCE OF SHOWERS INTO WESTERN SECTIONS OF
THE CWA PRIOR TO 18Z. THEN WILL INCREASE POPS INTO THE LIKELY RANGE
EAST OF THE LAKE SHORE BY MID AFTERNOON. LOOKING AT MODIFIED
SOUNDINGS FOR TOMORROW AFTERNOON...ML CAPES ARE A LITTLE HIGHER THAN
DEPICTED YESTERDAY...BUT STILL STRUGGLE TO SQUEAK OUT 50-75 J/KG OF
INSTABILITY. INSTABILITY IS BETTER OVER SOUTHWEST WISCONSIN
COMPARED TO OUR REGION...SO THINK WILL LEAVE OUT A MENTION OF
THUNDER. HIGH TEMPS SHOULD RISE INTO THE LOW TO MID 50S BEFORE THE
RAIN SHOWERS ARRIVE.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 216 PM CDT THU MAY 1 2014
SIGNIFICANT PATTERN CHANGE DURING THE PERIOD AS UPPER FLOW ACROSS
THE CENTRAL U.S. GOES FROM NW TO SW.
EARLY IN PERIOD...STILL DEALING WITH UPPER LOW OVER SE CANADA AND
ONE MORE WEAK DISTURBANCE. ON SATURDAY...MARGINAL INSTABILITY
SHOULD BE SUFFICIENT FOR MID-DAY OR AFTERNOON SHOWERS. BRIEF DRY
PERIOD THEN AS SFC RIDGE MOVES ACROSS STATE.
NEXT SYSTEM MOVES TOWARD REGION MIDWEEK. GFS AND ECMWF IN GENERAL
AGREEMENT ON MOVEMENT AND LOCATION...THOUGH GFS A BIT FASTER.
WARM FRONT MAKES NORTH PUSH INTO STATE ON WED. ELEVATED CONVECTION
EXPECTED AS RIPPLES IN SW FLOW MOVE OVER LOW-LEVEL CONVERGENCE
ALONG FRONT. FRONTAL POSITION WILL HAVE SIGNIFICANT IMPACT ON
TEMPS...ESP NEXT THURS. WILL SIDE WITH SLOWER ECMWF FOR NOW...AS
COLD LAKE MICH SHOULD SLOW DOWN NORTH PUSH...AT LEAST INITIALLY.
TEMP FORECAST FOR THE MAJORITY OF THE LONG TERM A BLEND OF BEST
PERFORMING GUIDANCE.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 635 PM CDT THU MAY 1 2014
CENTER OF THE UPPER LOW WILL CONTINUE TO DEPART TO THE NORTHEAST
OVERNIGHT. CIGS LATE THURSDAY AFTERNOON RANGE FROM MVFR TO VFR
SOUTHEAST OF THE SURFACE TROUGH FROM ROM MENOMINEE TO SHAWANO TO
WAUTOMA....TO A LOWER CIG OF MVFR/IFR OVER CENTRAL AND
NORTH CENTRAL WISCONSIN. ANTICIPATE THESE LOWER CIGS WILL SPREAD
OVER THE REST OF THE AREA TONIGHT WITH TROF PASSAGE AND WINDS
TURNING NORTHWEST. CONDITIONS WILL LIKELY PERSIST FRIDAY MORNING
BEFORE MIXING AND LIFT DUE TO A SHORT WAVE APPROACHING FROM THE
NORTH PLAINS IMPROVES CIGS. SCATTERED SHOWERS ARE EXPECTED BY
AFTERNOON OVER MOST LOCATIONS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......JKL
AVIATION.......TDH
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 MIAMI FL
153 AM EDT FRI MAY 2 2014
.AVIATION...
DRY AND VFR CONDITIONS WILL PREVAIL THIS MORNING. AFTER NOON...A
FEW SHOWERS ARE POSSIBLE...WITH POPS RANGING FROM 20-30 PERCENT
OVER BROWARD AND MIAMI-DADE TERMINALS TO AROUND 40 PERCENT KAPF
AND KPBI...WHERE VCSH IN PLACE. BY LATE EVENING...ACTIVITY SHOULD
WANE...ALTHOUGH ISOLATED SHOWERS CANT BE RULED OUT. WINDS WILL
REMAIN SOUTHEAST...LIGHT THIS MORNING THEN 10-15 KTS DURING THE
AFTERNOON...DIMINISHING AGAIN AFTER SUNSET.
&&
.PREV DISCUSSION... /ISSUED 1001 PM EDT THU MAY 1 2014/
UPDATE...A FEW SHOWERS PERSIST AROUND LAKE OKEECHOBEE, BUT THEY
ARE EXPECTED TO DISSIPATE THROUGH MIDNIGHT WITH TRANQUIL WEATHER
PREVAILING OVERNIGHT. HRRR SHOWS ANY ADDITIONAL SHOWER DEVELOPMENT
OVERNIGHT TAKING PLACE NORTH OF THE LAKE. MADE NO SIGNIFICANT
CHANGES TO THE FORECAST THIS EVENING. PLEASE SEE PREVIOUS
DISCUSSION BELOW FOR MORE FORECAST DETAILS. /GREGORIA
PREV DISCUSSION... /ISSUED 222 PM EDT THU MAY 1 2014/
SHORT TERM (TONIGHT-SATURDAY NIGHT)...
THE DEEP LAYER RIDGE THAT HAS DOMINATED THE WEATHER ACROSS SOUTH
FLORIDA THE PAST SEVERAL DAYS WILL BEGIN TO WEAKEN AND SHIFT EAST ON
FRIDAY AND INTO THE WEEKEND. THIS IS IN RESPONSE TO THE LARGE CUT-
OFF LOW THAT HAS BEEN SPINNING ACROSS THE CENTRAL PART OF THE U.S.
GETTING KICKED TO THE NORTHEAST AS UPSTREAM TROUGHS DEVELOP TO ITS
WEST. ALL OF THIS WILL AID IN THE ASSOCIATED COLD FRONT TO SLOWLY
SHIFT SOUTH DOWN THE FLORIDA PENINSULA OVER THE NEXT 48-60 HOURS.
GLOBAL MODELS HAVE BEEN COMING MORE IN LINE WITH EACH OTHER ON THE
TIMING ACROSS SOUTH FLORIDA BUT MORE ON THAT LATER. AT ANY RATE,
STILL EXPECT SOME SHOWER AND THUNDERSTORM DEVELOPMENT ACROSS THE
INTERIOR THIS AFTERNOON AS THE ATMOSPHERE REMAINS QUITE UNSTABLE
WITH A LOW LEVEL SSE FLOW. HOWEVER, THE MID LEVEL LAPSE RATES ARE
NOT AS IMPRESSIVE AS THE PAST FEW DAYS WITH A 3-6KM LAPSE RATE OF
5.6C/KM THIS MORNING COMPARED TO 6.3C/KM FROM WEDNESDAY MORNING AND
7C/KM ON MONDAY.
AS THE FRONT SLOWLY SLIDES TO THE SOUTH ON FRIDAY AND OVER THE EARLY
PART OF THE WEEKEND, MOISTURE WILL BE ON THE INCREASE ESPECIALLY BY
SATURDAY. FORECAST SOUNDINGS SHOW PWAT REMAINING SIMILAR ON FRIDAY
TO TODAY AT AROUND 1.25-1.35 INCHES BUT THEN INCREASING TO 1.6-1.8
INCHES BY SATURDAY AFTERNOON. HOWEVER, THE 500MB TEMPERATURES WARM
OVER THE NEXT FEW DAYS WITH THE RANGE OF -7.5C TO -9C TODAY WARMING
TO RANGE OF -7C TO -8C BY SATURDAY AFTERNOON. IN OTHER WORDS, MID
LEVEL LAPSE RATES WILL BECOME EVEN MORE UNIMPRESSIVE EARLY IN THE
WEEKEND ALONG WITH THE FLOW BECOMING UNIDIRECTIONAL WELL AHEAD OF
THE FRONT. HOWEVER, DUE TO A WARM SURFACE FLOW ALONG WITH THE CLOSE
PROXIMITY OF THE FRONT BY SATURDAY THERE COULD BE SOME STRONGER WIND
GUSTS WITH SOME OF THE CELLS.
LONG TERM (SUNDAY-THURSDAY)...
AS MENTIONED EARLIER ABOUT MODEL CONSENSUS, THE GFS, ECMWF AND NAM
ARE ALL SHOWING THE FRONT MOVING ACROSS SOUTH FLORIDA LATE SATURDAY
INTO EARLY SUNDAY. SO THINK THE NON POP FORECAST FOR SUNDAY MAY HAVE
BEEN A LITTLE PREMATURE SO WILL INCREASE POPS ON SUNDAY TO 30% FOR
THE SOUTHERN PORTIONS AND TAILORING DOWNWARD FARTHER TO THE NORTH.
THE REMAINDER OF THE EXTENDED PERIOD LOOKS TO BE A DRY FORECAST AS A
DEEP LAYER RIDGE ONCE AGAIN BUILDS ACROSS SOUTH FLORIDA.
MARINE...
THE WINDS WILL BECOME A MORE SOUTHERLY DIRECTION FOR FRIDAY INTO
EARLY PART OF THE WEEKEND. THE WINDS WILL THEN VEER TO A
NORTHERLY DIRECTION ON SUNDAY INTO EARLY NEXT WEEK...AS WIND
SPEEDS REMAIN AROUND 15 KNOTS. THIS WILL KEEP THE SEAS BELOW 6
FEET IN BOTH THE ATLANTIC AND GULF WATERS OF SOUTH FLORIDA THROUGH
LATE THIS WEEK BEFORE INCREASING TO AROUND 7 FEET BY LATE THIS
WEEKEND.
SMALL NORTHEAST SWELL WILL BUILD INTO SOUTH FLORIDA ATLANTIC
WATERS INTO THIS WEEKEND. THESE NORTHEAST SWELLS WILL ALLOW FOR
THE CONTINUATION OF THE RISK OF RIP CURRENTS ALONG THE EAST COAST
BEACHES OF SOUTH FLORIDA THROUGH THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 75 87 70 / 30 20 50 30
FORT LAUDERDALE 87 77 88 73 / 10 10 40 30
MIAMI 87 76 87 73 / 10 10 40 30
NAPLES 86 74 83 69 / 10 20 50 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 8 AM EDT THIS MORNING FOR FLZ168.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...54/BNB
LONG TERM....54/BNB
AVIATION...23/SK
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
125 AM EDT FRI MAY 2 2014
.UPDATE...
/ISSUED AT 852 PM EDT THU MAY 1 2014/
HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST OVERNIGHT.
SHORTWAVE ENERGY STILL PROGGED TO ENHANCE LIGHT PRECIPITATION
ACROSS THE SOUTHERN ZONES TOWARDS SUNRISE. HRRR STILL SUPPORTS
THIS...AND WILL NOT MAKE CHANGES TO POPS AT THIS TIME.
HAVE ONLY MADE MINOR CHANGES TO THE HOURLY TEMPS/DEWS.
&&
.PREV DISCUSSION... /ISSUED 721 PM EDT THU MAY 1 2014/
PREV DISCUSSION... /ISSUED 346 PM EDT THU MAY 1 2014/
SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
LATEST SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY MOVING PAINFULLY
SLOW THROUGH THE FORECAST AREA WITH IT NOW STRETCHING FROM
GREENVILLE THROUGH ATHENS AND ATLANTA. AHEAD OF THE FRONT...DEEPER
MOISTURE HAS COMBINED WITH SUBTLE UPPER LEVEL ENERGY TO RESULT IN
CONTINUED GOOD COVERAGE OF SHOWERS AND ISOLATED THUNDERSTORMS.
WITH THIS PARTICULAR SHORTWAVE SHIFTING EAST...SHOULD SEE A
REDUCTION IN POPS THIS EVENING WITH CURRENT LIKELY COVERAGE
REDUCED TO CHANCE POPS.
THIS BREAK LOOKS TO BE SHORT LIVED HOWEVER AS ANOTHER SHORTWAVE
MOVES IN FROM ALABAMA AROUND 06Z TONIGHT ENHANCING AND LIFTING
SHIELD OF PRECIPITATION NORTHWARD. HAVE LEANED CLOSE TO THE NAMMB
WHICH HAS PERFORMED WELL OF LATE AND BRING HEALTHY POP COVERAGE OF
80 PERCENT TO EXTREME SOUTHERN TIER BUT TAPER OFF RAPIDLY TO LESS
THAN 20 FOR THE ATLANTA METRO. FEEL LIKE THUNDER THREAT MAY BE OVER
FOR THIS AFTERNOON AND EVENING BUT MAY RETURN AS EARLY AS MID
MORNING WITH ONLY ISOLATED TSRA PLANNED. HAVE GONE ABOVE GUIDANCE
ON TEMPS TONIGHT AS EXTENSIVE CLOUD COVER SHOULD KEEP SIGNIFICANT
TEMP DROP IN CHECK.
FINAL SHORTWAVE FRIDAY NIGHT AND SATURDAY MORNING IS MORE
SUBSTANTIAL AND SHOULD PRODUCE A CLEARING TREND FOR THE WEEKEND
WITH FRONT FINALLY CLEARING THE AREA AND A RETURN TO MOSTLY SUNNY
CONDITIONS.
DEESE
LONG TERM /SATURDAY THROUGH THURSDAY/...
NO CHANGES MADE TO THE EXTENDED FORECAST AS A DRY FORECAST WILL
CONTINUE. WE WILL MOSTLY BE UNDER MOIST SOUTHERLY FLOW THROUGH THE
EXTENDED...SO WE WILL SEE CLOUDS OFF AN ON THROUGH DAY 7 BUT NO
PRECIP EXPECTED. A DRY BACKDOOR COLD FRONT MOVES CLOSE TO THE FAR
NE EARLY MONDAY BUT LOOKS TO STALL AND MOVE BACK NE INTO TUESDAY.
THE FRONT WILL HAVE VERY LIMITED MOISTURE SO AGAIN NO PRECIP IS
EXPECTED WITH IT. HIGH PRESSURE ALOFT WILL BUILD INTO THE AREA
TUESDAY AND WEDNESDAY CONTINUING TO KEEP THINGS DRY.
FORECAST LOW TEMPERATURES RUNNING AROUND 5 DEGREES BELOW NORMAL
SATURDAY MORNING THEN NEAR TO ABOVE NORMAL SUNDAY TO THURSDAY.
01
&&
.AVIATION...
06Z UPDATE...
VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST AT ALL SITES. A
SHORT WAVE WILL BRING 4000-5000FT CIGS INTO CSG/MCN THIS MORNING AND
CONTINUE INTO THIS AFTERNOON. A CU FIELD SHOULD FORM BRINGING
SCT-BKN050 THIS AFTERNOON. ALL CIGS SHOULD DISSIPATE BY OR AROUND
SUNSET THIS EVENING. WINDS WILL BE NEAR CALM EARLY THIS
MORNING...AND THEN LIGHT WESTERLY THROUGH THE DAY TODAY.
//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 50 72 48 77 / 20 20 5 5
ATLANTA 52 70 51 75 / 10 10 5 5
BLAIRSVILLE 44 65 43 71 / 5 5 5 5
CARTERSVILLE 46 69 46 75 / 5 5 5 5
COLUMBUS 53 72 51 77 / 50 50 20 5
GAINESVILLE 51 68 50 74 / 5 5 0 5
MACON 52 70 48 77 / 60 60 20 5
ROME 46 68 46 76 / 5 5 0 5
PEACHTREE CITY 47 71 45 76 / 20 20 5 5
VIDALIA 57 67 53 76 / 80 80 50 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ATWELL
LONG TERM....ATWELL
AVIATION...ATWELL
AREA FORECAST DISCUSSION
NWS CARIBOU ME
600 AM EDT FRI MAY 2 2014
.SYNOPSIS...
AN UNSETTLED WEATHER PATTERN WILL PERSIST THROUGH THE WEEKEND INTO
EARLY NEXT WEEK WHILE SEVERAL LOWS CROSS THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
6AM UPDATE...
ADDED ISOLATED THUNDERSTORMS FOR A WIDE SWATH OF THE FORECAST AREA
THAT EXCLUDES THE CROWN OF MAINE AND DOWN EAST COASTAL AREAS.
USING RAP CAPE VALUES...THERE IS JUST ENOUGH CAPE ABOVE -20C TO
JUSTIFY INCLUSION OF THE THUNDERSTORMS. THE UPPER TROUGH IS QUITE
SHARP AND SHOULD GENERATE STRONG LIFT LATER THIS AFTERNOON INTO
EARLY EVENING. THIS PRECIPITATION WILL ALSO ENHANCE POTENTIAL FOR
SHALLOW FOG TONIGHT.
OTHERWISE...MADE TWEAKS TO FORECAST FOR THE FOG THAT WILL BE
RETREATING IN THE NEXT FEW HOURS THIS MORNING AS WELL AS THE
PRECIP CURRENTLY MOVING THROUGH DOWN EAST WITH THE SURFACE TROUGH.
PREVIOUS DISCUSSION...
AN OCCLUDED FRONT LIES TO THE NORTH OF THE AREA AND HAS BROUGHT
THE WARMEST AIR MASS OF THE YEAR INTO THE AREA. HIGHS TODAY WILL
REACH THE LOW TO MID 60S FOR MOST AREAS WITH FOG BURNING OFF EARLY
THIS MORNING AND GIVING WAY TO SUNSHINE. CLOUDS INCREASE THIS
AFTERNOON WITH SHOWERS DEVELOPING IN ASSOCIATION WITH AN UPPER
TROUGH. ALL GUIDANCE SHOWS VERY MARGINAL SURFACE-BASED CAPE OF
PERHAPS 200 J/KG AND LOW CLOUD TOPS. AS A RESULT...HAVE NOT ADDED
MENTION OF ANY THUNDERSTORMS TO THE FORECAST. HOWEVER...WITH -20C
BEING SO LOW IN THE ATMOSPHERE...CANNOT RULE OUT ONE OR TWO
LIGHTNING STRIKES. THE BEST CHANCE WOULD SEEM TO BE SOUTH OF A
LINE FROM HOULTON TO MILLINOCKET...AND NORTH OF A LINE FROM BANGOR
TO CALAIS. CLOUDS WILL QUICKLY DIMINISH THIS EVENING EXCEPT IN THE
CROWN OF MAINE. LOWS WILL DIP TO THE UPPER 30S TO LOW 40S WITH
LIGHT WINDS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
A DEEP UPPER LOW NEAR LAKE WINNIPEG AS 12Z SAT WILL TRACK INTO
NORTHERN NEW ENGLAND BY 00Z MON. AS THE LOW ADVANCES TOWARD THE
REGION SAT ANY BREAKS IN THE CLOUDS IN THE MORNING WILL GIVE WAY
TO INCREASING CLOUDS ALONG WITH THE CHANCE OF A COUPLE OF
SHOWERS...MAINLY ACROSS WESTERN AND NORTHERN MAINE. WET WEATHER
IS EXPECTED SAT NIGHT AND ESPECIALLY SO DURING THE DAY SUNDAY AS
THE UPPER LOW AND SFC LOW TRACK ACROSS THE REGION. TEMPS ARE
EXPECTED TO BE NEAR SEASONABLE LEVELS SATURDAY AND WILL BE BELOW
NORMAL SUNDAY WITH THE THICKER CLOUD COVER AND RAIN. THE QPF IS
EXPECTED TO BE ON THE ORDER OF A THIRD OF AN INCH TO THREE
QUARTERS OF AN INCH FROM SAT NIGHT THROUGH SUN AND SHOULD HAVE
MINIMAL HYDROLOGICAL IMPACTS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE LOW SLOWLY MOVES EAST OF THE AREA AND ACROSS THE MARITIMES EARLY
NEXT WEEK. THIS WILL KEEP THE REGION IN A COOL/CYCLONIC FLOW ALOFT
WITH A FEW SHOWERS...ESPECIALLY SO DURING THE HEATING OF THE DAY AS
THE ATMOSPHERE DESTABILIZES. THE CHANCE OF SHOWERS MAY CONTINUE
THROUGH THE MIDDLE OF THE WEEK. TEMPERATURES ARE EXPECTED TO
AVERAGE A BIT BELOW NORMAL EARLY NEXT WEEK AND RETURN TO NEAR
SEASONABLE LEVELS BY THE MIDDLE OF THE WEEK. THERE ARE CERTAINLY
NO SIGNS OF ANY SIGNIFICANT WARM-UPS OVER THE NEXT WEEK.
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: LIFR IN FOG WILL MOVE OUT THIS MORNING...LEAVING BHB
LAST BY MID-MORNING. THE FOG WILL BE REPLACED BY VFR CONDITIONS.
AN ISOLATED THUNDERSTORM IS POSSIBLE THIS AFTERNOON. PREVAILING
VFR IS EXPECTED TONIGHT.
SHORT TERM: A PERIOD OF VFR OR AT LEAST HIGH END MVFR SAT WILL GIVE
WAY TO IFR IN RAIN AND PATCHY FOG LATER SAT NIGHT INTO SUN. MOSTLY
MVFR EARLY NEXT WEEK AT THE NORTHERN TAF SITES AND MVFR/VFR AT AT
THE DOWNEAST TERMINALS.
&&
.MARINE...
NEAR TERM: HAVE CANCELLED THE SCA FOR HAZARDOUS SEAS AND DO NOT
ANTICIPATE ANY SIGNIFICANT WINDS OR SEAS THROUGH THE PERIOD. FOG
WILL GRADUALLY MOVE OUT TODAY.
SHORT TERM: THE WIND AND SEAS ARE EXPECTED TO REMAIN BELOW SCA
CONDITIONS THROUGH SAT NIGHT. A SLY FETCH AHEAD OF THE INCOMING LOW
MAY CAUSE THE SEAS TO BUILD TO AOA 5FT SUNDAY AND A SCA IS
POSSIBLE. A SCA WILL LIKELY BE REQUIRED EARLY NEXT WEEK AS LOW
PRES PULLS AWAY FROM THE WATERS AND WLY FLOW INCREASES WITH GUSTS
IN EXCESS OF 25 KNOTS LIKELY.
&&
.CLIMATE...
THE APRIL 2014 CLIMATE SUMMARY FOR NORTHERN AND EASTERN
MAINE HAS BEEN ISSUED. PLEASE REFER TO PWMCLMCAR OR CXUS51 KCAR.
THE SUMMARY IS ALSO AVAILABLE ON THE TOP NEWS STORY ON OUR WEB
PAGE AT: HTTP:/WEATHER.GOV/CAR
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MCW
SHORT TERM...CB
LONG TERM...CB
AVIATION...MCW/CB
MARINE...MCW/CB
CLIMATE...CB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
342 AM CDT FRI MAY 2 2014
.SYNOPSIS...
ISSUED AT 341 AM CDT FRI MAY 2 2014
AT 08Z...A COLD FRONT WAS MOVING SOUTHEAST THROUGH NORTHWESTERN
NORTH DAKOTA. ACROSS WESTERN NEBRASKA WINDS WERE LIGHT WESTERLY AT
5 MPH OR LESS. BENEATH MOSTLY CLEAR SKIES...TEMPERATURES WERE IN
THE LOWER TO MID 30S...WITH THE COLDEST READING OF 27 AT LBF.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 341 AM CDT FRI MAY 2 2014
A HIGHLY AMPLIFIED H5 PATTERN EXISTS WITH A STRONG RIDGE ALONG
THE WESTERN STATES WHILE A POSITIVELY TILTED TROUGH EXTENDED FROM
WEST TEXAS INTO THE GREAT LAKES REGION. FOR TODAY...INCREASING
CLOUDINESS WITH A WEAK COLD FRONT DROPPING SOUTH INTO THE
NORTHERN PANHANDLE AND CENTRAL NEBRASKA BY LATE AFTERNOON. NOT
TOO MUCH CONTRAST IN HIGHS HOWEVER RANGING FROM THE UPPER 60S AT
VTN...ANW AND ONL TO 76 AT IML. NW WINDS TO RANGE FROM 10 TO 20
MPH TODAY...WHICH WILL BE LIGHTER THAN THE PAST SEVERAL DAYS.
REGARDING CHANCES FOR ANY SHOWERS OR THUNDERSTORMS...HAVE TRIMMED
WEST THE AREA TO MAINLY THE EASTERN PANHANDLE AND WESTERN CHERRY
COUNTY THIS AFTERNOON. THE NAM AND RAP MODELS ARE SIMILAR
TARGETING THESE AREAS. A DISTURBANCE TO MOVE THROUGH EASTERN
WYOMING AND THE BLACK HILLS REGION EARLY THIS AFTERNOON AND
SHOULD TRIGGER ISOLATED SHOWERS OR THUNDERSTORMS. THE STEEPER H7
TO H5 LAPSE RATES NEAR 7.5 C.KM WILL BE PERCENT IN THE PANHANDLE
AND SW NEBR THIS AFTERNOON. A DISTURBANCE BEHIND THE COLD FRONT
WILL TRIGGER SOME SHOWERS FROM EASTERN MONTANA INTO WESTERN AND
CENTRAL SOUTH DAKOTA TODAY. WHILE A FEW OF THESE SHOWERS COULD
MOVE INTO NORTH CENTRAL NEBRASKA THIS AFTERNOON...MODELS DO NOT
SUPPORT SUFFICIENT LIFT TO INTRODUCE A MENTION.
TONIGHT...CONTINUED A SLIGHT CHANCE FOR SHOWERS IN THE EASTERN
PANHANDLE AND WESTERN CHERRY COUNTY...WHICH SHOULD DISSIPATE BY
AROUND SUNSET. WITH A MILDER AIR MASS IN PLACE AND WEAK LOW
PRESSURE...TEMPERATURES WILL RANGE FROM THE UPPER 30S FAR
NORTHWEST TO THE LOWER 40S ELSEWHERE. SKIES WILL BE CLEARING IN
THE WEST WITH LINGERING CLOUDINESS ACROSS THE EAST.
SYNOPTICALLY...THE UPPER RIDGE IN THE WEST WILL FLATTEN OUT AS IT
MOVES INTO THE GREAT BASIN WHILE A CLOSED LOW MOVES INTO MANITOBA
AND WESTERN ONTARIO. THIS WILL KEEP THE COOLER AIR TO OUR NORTH
ACROSS THE DAKOTAS AND GREAT LAKES.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 341 AM CDT FRI MAY 2 2014
SATURDAY WILL SEE THE LOW PUSHING ACROSS THE NE PACIFIC...HEADING
FOR THE PACIFIC NW STATES. THIS WILL CAUSE THE HIGH ACROSS THE
DESERT SOUTHWEST TO PUSH EAST. MEANWHILE A LEE SIDE TROUGH WILL
DEVELOP. AS THE RIDGE SLIDING EAST...HEIGHTS INCREASE ACROSS THE
AREA. NAM HAS BEEN THE FASTEST WITH THE HEIGHT INCREASES...WHICH
HAS TRANSLATED TO MET GUIDANCE IN SW NEB INTO THE 80S. THE
SLIGHTLY SLOWER GFS/EC MOS GUIDANCE HAS HELD MOST SITES ACROSS SW
IN THE 70S. THE SW PART OF NEB DID SEE A QUARTER TO HALF AN INCH
WITH THIS LATE APRIL EVENT...HOWEVER THE MONTH ENDED 1 TO 2 INCHES
BELOW NORMAL. EXPECT THE RELATIVELY DRY SOILS TO AID IN WARMING
CLOSER TO THE MET GUIDANCE NUMBERS. ALTHOUGH LATELY THE WARMEST
GUIDANCE HAS BEEN THE WAY TO GO DURING THESE ABOVE NORMAL
DAYS...SO MAY NEED TO TREND THIS WARMER YET. MEANWHILE A SFC HIGH
WILL DIVE SOUTH INTO THE NORTHERN PLAINS. WHILE THE HIGH IS
CENTERED WELL NORTH OF THE AREA...COOLER AIR IN ASSOCIATION WITH
THE HIGH WILL PUSH INTO THE DAKOTAS AND PARTS OF NRN NEB. HIGHS ON
SAT ACROSS THE NORTH SHOULD WARM TO AROUND 70.
SATURDAY AFTERNOON STEEP LAPSE RATE DEVELOP ALONG THE LEE SIDE
TROUGH. WOULD EXPECT SOME SHOWERS TO DEVELOP DURING THE PEAK
HEAT...ALTHOUGH MOISTURE...DEW PTS IN THE 40S...MAY BE TOO DRY
FOR ANYTHING TO REACH THE GROUND. A BETTER CHANCE...ALBEIT ONLY
SLIGHTLY BETTER...WILL BE WITH A QUASI-STATIONARY BOUNDARY
BETWEEN THE COOLER NORTHERN HIGH AND WARMER SW SAT EVENING. AGAIN
MOISTURE IS A CONCERN AND RETAINED LOW POPS...ALTHOUGH NOT
LOOKING AS GOOD AS YESTERDAY AND SCALED BACK THE COVERAGE.
SUNDAY THE RIDGE CONTINUES TO ADVANCE EAST...BUT BECOMES MORE
BROAD. HIGHS AGAIN INTO THE 80S ACROSS SW WITH MORE CLOUDS ACROSS
THE NORTH...NEAR THE BOUNDARY...AND HIGHS IN THE 60S. SUNDAY
EVENING THE BOUNDARY LIFTS NORTH AND FORECAST AREA LOOKS DRY WITH
THE ACTIVITY NORTH OF THE BORDER.
BY MONDAY THE BROAD RIDGE AXIS WILL BE EAST WITH SW NEB DROPPING
TO AROUND 80. MORE SUN ACROSS THE NORTH AND HIGHS SHOULD BE ABLE
TO WARM ABOVE SUNDAY READINGS...CLOSER TO 70.
TUESDAY THROUGH THE THURSDAY A MORE ACTIVE PATTER IS SETTING UP.
THE NORTHEAST PACIFIC LOW WILL OPEN INTO A TROUGH AS IT DIGS INTO
THE 4 CORNERS REGION. THE GFS CONTINUES TO THEN EJECT THE LOW
ONTO THE CENTRAL PLAINS. THE ECMWF BREAKS UP THE LOW WITH A PIECE
PUSHING ONTO THE PLAINS WITH A SECONDARY LOW DEVELOPING OFF THE
COAST OF BAJA. EITHER WAY BOTH MODELS SUPPORT A CHANCE FOR
PRECIPITATION ACROSS THE AREA. THE GULF DOES OPEN UP...HOWEVER
THIS IS SHORT LIVED WITH A COLD FRONT TO PUSH ACROSS THE AREA AND
KEEP THE BULK OF THE MOISTURE SOUTH AND EAST OF THE AREA. TEMPS
COOL INTO THE 60S AND 70S...AND WILL CONTINUE TO MONITOR THE
MOISTURE PUSH NORTHWARD WHICH WILL EFFECT THE QPF AMOUNTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1237 AM CDT FRI MAY 2 2014
CEILING AND VISIBILITY WILL BE UNLIMITED TONIGHT AND FRIDAY
MORNING. A FRONT COMING ACROSS NEBRASKA WILL THEN BRING ISOLATED
SHOWERS OR THUNDERSTORMS TO CENTRAL AND NORTHERN NEBRASKA...BUT
THE PROBABILITY OF EITHER OCCURRING AT ANY ONE SITE IS LESS THAN
20 PERCENT. HOWEVER...CEILINGS OF 5000-8000 FEET AGL ARE LIKELY.
WIND WILL INCREASE OVER MUCH OF THE AREA BY 16Z AND BECOME
280-310 AT 12-16G17-22KT BUT WILL BECOME VARIABLE FRIDAY EVENING
AT LESS THAN 10KT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...MASEK
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
240 AM CDT FRI MAY 2 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 240 AM CDT FRI MAY 2 2014
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO BRITISH COLUMBIA...AN
UPPER LOW AND SHORTWAVE TROUGH OVER NORTHERN ALBERTA/SASKATCHEWAN...
A SHORTWAVE TROUGH OVER SOUTHERN MANITOBA...AND AN ELONGATED LONG
WAVE TROUGH FROM TEXAS INTO THE GREAT LAKES. THE FORECAST AREA LIES
NOW IN SUBSIDENCE IN THE WAKE OF THE LONG WAVE TROUGH...PROMOTING
DRY AIR ADVECTION FROM THE NORTHWEST. THIS CAN BE SEEN BY THE LOW
STRATUS DECK CLEARING ACROSS MINNESOTA ON 11-3.9UM IMAGERY AND
SURFACE OBSERVATIONS. 00Z BIS AND ABR SOUNDINGS WERE ALSO QUITE DRY
WITH PRECIPITABLE WATER OF ONLY 0.3-0.4 INCHES. REPLACING THE
STRATUS DECK HAS BEEN MID AND HIGH CLOUDS SPREADING SOUTHEAST ACROSS
THE DAKOTAS AND MINNESOTA...AHEAD OF THE SHORTWAVE THERE. GRAND
FORKS RADAR DISPLAYING SOME LIGHT RETURNS AS WELL...BUT SO FAR THE
DRY AIR HAS BEEN WINNING OUT KEEPING THE PRECIPITATION AS VIRGA.
AIRMASS OVER THE FORECAST AT 00Z WAS STILL UNSEASONABLY COOL WITH
925MB TEMPS AROUND 4C...BUT WARMER 9-13C READINGS WERE LURKING
UPSTREAM AT ABR AND BIS. BEHIND THE SHORTWAVE TROUGH IN SOUTHERN
MANITOBA...SKIES CLEAR OUT AND SURFACE PRESSURES WERE RISING ABOUT 1
MB/HR...PROMOTING GUSTY WINDS ACROSS NORTH DAKOTA.
MODELS ARE IN GOOD AGREEMENT DROPPING THE SOUTHERN MANITOBA
SHORTWAVE SOUTHEASTWARD THROUGH THE FORECAST AREA THIS AFTERNOON.
MORE IMPORTANTLY...THERE IS A CONSISTENT SIGNAL FROM ALL MODELS FOR
THE SHORTWAVE TO WEAKEN SOME. THIS WEAKENING COMBINED WITH THE DRY
ADVECTION CURRENTLY TAKING PLACE FROM THE NORTHWEST BRINGS IN SOME
CONCERN FOR PRECIPITATION CHANCES TODAY. HARD TO FIND A MODEL THAT
DOESNT PRECIPITATE WITH THE SHORTWAVE...WHICH MAKES SENSE IN
GENERAL GIVEN WE HAVE A SHORTWAVE TROUGH COMING THROUGH AT PEAK
HEATING. BETWEEN DYNAMICS AND INSTABILITY FROM HEATING...SHOWERS
DEVELOPING IS REASONABLE. HOWEVER...IT IS WORTH NOTING THAT 2 METER
DEWPOINT GUIDANCE FROM THE BASE MODELS SUCH AS THE ECMWF...GFS...NAM
AND REGIONAL CANADIAN ALL PUSH DEWPOINTS WELL INTO THE 40S...WITH
EVEN THE GFS AND REGIONAL CANADIAN APPROACHING 50 BY 00Z. THIS SEEMS
A BIT HIGH GIVEN CURRENT SURFACE DEWPOINTS IN THE UPPER 20S TO MID
30S OVER THE DAKOTAS. PERHAPS THE MODELS ARE THINKING GREEN-UP HAS
ALREADY TAKEN PLACE BASED ON CLIMATOLOGY. WE DO HAVE WET SOILS SO
THAT COULD PROMOTE SLIGHTLY HIGHER DEWPOINTS. IN SUMMARY...FEEL
FAIRLY CONFIDENT THAT WE WILL SEE SHOWERS THIS AFTERNOON...BUT A
LITTLE LESS CERTAIN ON IF THEY WILL BE WIDESPREAD. ANOTHER CHANGE
WORTH NOTING IS THAT THE 02.00Z NAM MUCAPE THIS AFTERNOON HAS
DROPPED FROM PREVIOUS RUNS...NOW BELOW 200 J/KG...WHICH MAKES SENSE.
CONSIDERED DROPPING THE THUNDER MENTION ENTIRELY AS A RESULT...BUT
THE RAP DOES DEPICT A ZONE OF 700-500MB LAPSE RATES APPROACHING 7
C/KM OVER THE FORECAST AREA DURING THE AFTERNOON. THEREFORE...HAVE
LEFT THE THUNDER IN THE FORECAST FOR THE AFTERNOON. ANY SHOWER
ACTIVITY SHOULD QUICKLY EXIT THE AREA BETWEEN 00-03Z WITH THE
SHORTWAVE EXITING AND DIURNAL COOLING.
AS WE APPROACH LATE TONIGHT...MORE SHOWER ACTIVITY LOOKS TO DROP
DOWN INTO NORTHERN MN AND WI. THESE ARE AHEAD OF THE SHORTWAVE
TROUGH AND UPPER LOW CURRENTLY IN NORTHERN ALBERTA/SASKATCHEWAN...
PROGGED TO BE OVER SOUTHERN MANITOBA AND NORTHERN MN BY 12Z
SATURDAY. ITS POSSIBLE THIS SHOWER ACTIVITY COULD GET INTO TAYLOR
COUNTY TOWARDS 12Z...BUT FOR NOW HAVE KEPT THE FORECAST DRY.
925MB TEMPERATURES ARE PROGGED A FEW DEGREES WARMER TODAY...BETWEEN
6-8C FOR THE AFTERNOON HOURS. THERE IS A CHANCE WE CAN SNEAK IN A
LITTLE SUN AND WITH A WARM ADVECTING SOUTHWEST WIND...MOST LOCATIONS
WILL CLIMB INTO THE 50S. THERES EVEN A CHANCE SOME SPOTS COULD PUSH
60...SUCH AS CHARLES CITY...WINONA...LA CROSSE AND BOSCOBEL. THIS
ALL HINGES IF WE CAN GET MORE SUN...BUT THINK OVERALL WE WILL BE
CLOUDY OR MOSTLY CLOUDY TODAY. COLD ADVECTION TONIGHT ON A NORTHWEST
WIND...WHICH COULD BE BRISK IN THE EVENING WEST OF THE MS RIVER WITH
THE PRESSURE RISE COMING THROUGH...WILL ALLOW TEMPERATURES TO DROP
INTO THE 30S TO LOW 40S TONIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 240 AM CDT FRI MAY 2 2014
UPPER LEVEL PATTERN CHANGE REMAINS ON TRACK DURING THE LONG TERM
PERIOD...WITH UPPER RIDGING CURRENTLY OVER THE WESTERN U.S. PROGGED
TO BUILD OVER THE REGION LATE TUESDAY INTO WEDNESDAY. THIS IS ALL IN
RESPONSE TO AN UPPER LOW CURRENTLY OFF THE PACIFIC NORTHWEST COAST
SUGGESTED TO DIG INTO THE SOUTHWESTERN U.S.. THIS PATTERN CHANGE
MEANS A GRADUAL MODERATION OF TEMPERATURES...ALONG WITH POTENTIAL
FOR MORE ACTIVE WEATHER AS WE APPROACH THE MIDDLE OF NEXT WEEK.
FIRST OFF...SATURDAY. THAT NEXT SHORTWAVE TROUGH AND UPPER LOW
CURRENTLY IN NORTHERN ALBERTA/SASKATCHEWAN WILL SLIDE ACROSS
NORTHERN PORTIONS OF MN AND WI...ALONG WITH UPPER MI AND ONTARIO
DURING THE DAY AND EVENING HOURS. THIS TRACK KEEPS THE BEST DPVA
FORCING NORTH OF THE FORECAST AREA. THEREFORE...THINK MUCH OF THE
PRECIPITATION WILL STAY NORTH AS WELL. HOWEVER...THERE WILL BE A
SURFACE COLD FRONT ACCOMPANYING THE SHORTWAVE. THE 02.00Z GFS PRINTS
OUT SOME LIGHT QPF OVER LA CROSSE AS THE FRONT COMES THROUGH...
MOSTLY A RESULT OF THE MODEL DEVELOPING SOME WEAK CAPE. BELIEVE THE
MODEL IS TOO FAR SOUTH AND OVERLY MOIST. HAVE DECIDED TO KEEP ANY
LOW CHANCES OF PRECIPITATION NORTH OF I-94...CONSISTENT TOO WITH THE
02.00Z ECMWF. 925MB TEMPS REBOUND DECENTLY ON SATURDAY...6-9C...
ALLOWING TEMPERATURES TO CLIMB SLIGHTLY HIGHER THAN THOSE TODAY.
NEXT UP IS ON SUNDAY WHERE THE 02.00Z GFS/CANADIAN/ECMWF/NAM ALL
DEVELOP A FRONTOGENETICAL BAND OF PRECIPITATION. THE BAND ALSO HAS
SOME RIGHT ENTRANCE REGION FORCING FROM A JET STREAK FOLLOWING THE
SATURDAY SHORTWAVE TROUGH. THE NAM IS THE ODD MODEL OUT ON LOCATION
OF THE BAND...TRACKING IT FROM MINNEAPOLIS TO LA CROSSE AND THE
DELLS...WHEREAS ALL OTHER MODELS SUGGEST SOUTHWEST MN INTO NORTHERN
IA AND NORTHERN IL AS THE MORE LIKELY TRACK. GIVEN GOOD AGREEMENT ON
THIS FRONTOGENETIC BAND FROM THE OTHER MODELS...HAVE RAISED
PRECIPITATION CHANCES. MODEL CONSENSUS SUGGESTS 12-18Z SUNDAY IS THE
MOST LIKELY TIME PERIOD FOR PRECIPITATION WITH THE PRECIPITATION
EXITING RAPIDLY TO THE SOUTHEAST IN THE AFTERNOON. THERE IS SOME
LOWER LEVEL DRY AIR PRESENT...WHICH IF THE PRECIPITATION WAS HEAVIER
MIGHT CAUSE PRECIPITATION TYPE ISSUES FROM EVAPORATIVE COOLING. FOR
NOW WILL KEEP THE PRECIPITATION TYPE AS RAIN GIVEN GENERALLY LIGHT
QPF PROGGED BUT SOMETHING TO WATCH. WITH THIS FRONTOGENETICAL BAND
GOING THROUGH AND A NORTHEAST BREEZE...TEMPERATURES ARE GOING TO
TAKE A COOL DOWN. THIS IS ESPECIALLY TRUE UNDER THE PRECIPITATION.
RAIN CHANCES COME BACK FOR MONDAY WHEN YET ANOTHER BAND OF
FRONTOGENESIS AND ISENTROPIC LIFT MOVES ACROSS. THIS ONE LOOKS
WEAKER THAN ON SUNDAY...THUS 02.00Z GFS/CANADIAN/ECMWF QPF IS
LIGHTER AND MORE SPREAD OUT ACROSS THE FORECAST AREA. CONSENSUS 20
PERCENT CHANCES SEEM REASONABLE. COOLED HIGHS SLIGHTLY FROM THE
PREVIOUS FORECAST DUE TO CLOUDS AND AN EAST WIND AROUND HIGH
PRESSURE IN UPPER MI. THESE COULD NEED FURTHER COOLING IF A LITTLE
MORE PRECIPITATION IS AROUND AS SUGGESTED BY THE 02.00Z ECMWF.
AS THE UPPER RIDGE BUILDS INTO THE AREA LATE TUESDAY AND ESPECIALLY
WEDNESDAY...THAT IS WHEN SOME BIGGER TEMPERATURE CHANGES TAKE
PLACE...ALONG WITH INCREASING CONCERNS FOR CONVECTION AND POSSIBLE
SEVERE WEATHER. 02.00Z GFS/ECMWF SUGGEST THAT BETWEEN 12Z WEDNESDAY
AND 00Z THURSDAY...925MB TEMPS COULD CLIMB AS MUCH AS 10-15C
RESULTING IN AN ALMOST SUMMER-LIKE AIRMASS COMING INTO LOCATIONS
ALONG AND SOUTH OF I-90. WE WILL HAVE TO WAIT AND SEE HOW THIS PANS
OUT. IN ANY EVENT...HAVE FOLLOWED CONSENSUS WITH 30-50 PERCENT
CHANCES FOR TUESDAY NIGHT AND WEDNESDAY...WITH SLIGHTLY HIGHER
CHANCES FOR WEDNESDAY NIGHT INTO THURSDAY RESULTING FROM A SHORTWAVE
TROUGH COMING THROUGH THE UPPER MIDWEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1110 PM CDT THU MAY 1 2014
THE MVFR CLOUD DECK HAS BEEN WORKING STEADILY EAST THIS EVENING AS
THE STORM SYSTEM THAT PLAGUED THE AREA THE PAST FEW DAYS CONTINUES
TO MOVE AWAY FROM THE REGION. THESE MVFR CLOUDS HAVE ALREADY MOVED
EAST OF KRST AND WILL DO THE SAME AT KLSE BY 09Z OR 10Z. EXPECT
THAT THE CEILINGS WILL POP UP TO AROUND 10 THOUSAND FEET OR SO FOR
A SHORT PERIOD FRIDAY MORNING AHEAD OF THE NEXT SYSTEM THAT IS
ALREADY QUICKLY APPROACHING FROM THE NORTHWEST. THIS SHORT WAVE
TROUGH IS SHOWN BY THE 02.00Z NAM TO MOVE ACROSS THE REGION FRIDAY
AFTERNOON BUT LOOKS TO BE WEAKENING AS IT DOES...WHICH IS SHOWN BY
THE DIMINISHING PV ADVECTION SIGNAL IN THE 500-300 MB LAYER.
EARLIER RUNS HAD SUGGESTED THAT THE LEFT EXIT REGION OF THE 300
MB JET WOULD ACCOMPANY THE SHORT WAVE TROUGH...BUT THE NAM HAS
BACKED AWAY FROM THIS HOLDING THE JET BACK UNTIL THE NEXT SYSTEM
COMES OUT OF CANADA FOR SATURDAY. THE DEEPEST MOISTURE LOOKS TO BE
OVER WISCONSIN WITH NOT MUCH OF SIGNAL FOR MOISTURE TO RETURN WITH
JUST A WEAK MOISTURE TRANSPORT SIGNAL OFF THE THE HIGH PLAINS AND
NOT FROM THE GULF REGION. THE NAM ALSO SHOWS LESS CAPE THAN
PREVIOUS RUNS WITH LESS THAN 100 J/KG OF ML CAPE AND ONLY AROUND
200 J/KG OF MU CAPE. HAVE STAYED WITH THE IDEA OF JUST SHOWING
SOME VICINITY SHOWERS FOR BOTH TAF SITES FRIDAY AFTERNOON AS
EXPECTING THE BETTER COVERAGE TO BE TO THE EAST. WITH THE LIMITED
CAPE...DID NOT INTRODUCE ANY THUNDER EITHER. THE THREAT FOR
SHOWERS SHOULD END LATE IN THE AFTERNOON OR EARLY IN THE EVENING
WITH SUBSIDENCE SETTING IN ALLOWING THE CLOUDS TO SCATTER OUT.
&&
.HYDROLOGY...
ISSUED AT 240 AM CDT FRI MAY 2 2014
RUNOFF FROM RECENT RAIN CONTINUES TO FLOW THROUGH THE MISSISSIPPI
RIVER TRIBUTARIES AND THE MAIN CHANNEL. CURRENTLY ONLY THE
MISSISSIPPI RIVER AT WABASHA IS IN FLOOD...BUT FORECASTS CONTINUE
TO POINT TO THE MISSISSIPPI RIVER AT WINONA...LA CROSSE...MCGREGOR
AND GUTTENBERG DAM 10 TO BEGIN MINOR FLOODING IN THE NEXT 1 TO 4.5
DAYS. IN ADDITION...THE BLACK RIVER AT GALESVILLE IS APPROACHING
FLOOD STAGE...BUT SHOULD NOT CLIMB MUCH ABOVE MINOR FLOOD WITH
FALLING RIVER LEVELS AT BLACK RIVER FALLS. NO MAJOR RAINS ARE
ANTICIPATED OVER THE NEXT 5 DAYS SO RUNOFF WILL BE THE MAIN
CONTRIBUTING FACTOR TO RIVER LEVELS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
643 AM CDT FRI MAY 2 2014
.SYNOPSIS...
ISSUED AT 341 AM CDT FRI MAY 2 2014
AT 08Z...A COLD FRONT WAS MOVING SOUTHEAST THROUGH NORTHWESTERN
NORTH DAKOTA. ACROSS WESTERN NEBRASKA WINDS WERE LIGHT WESTERLY AT
5 MPH OR LESS. BENEATH MOSTLY CLEAR SKIES...TEMPERATURES WERE IN
THE LOWER TO MID 30S...WITH THE COLDEST READING OF 27 AT LBF.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 341 AM CDT FRI MAY 2 2014
A HIGHLY AMPLIFIED H5 PATTERN EXISTS WITH A STRONG RIDGE ALONG
THE WESTERN STATES WHILE A POSITIVELY TILTED TROUGH EXTENDED FROM
WEST TEXAS INTO THE GREAT LAKES REGION. FOR TODAY...INCREASING
CLOUDINESS WITH A WEAK COLD FRONT DROPPING SOUTH INTO THE
NORTHERN PANHANDLE AND CENTRAL NEBRASKA BY LATE AFTERNOON. NOT
TOO MUCH CONTRAST IN HIGHS HOWEVER RANGING FROM THE UPPER 60S AT
VTN...ANW AND ONL TO 76 AT IML. NW WINDS TO RANGE FROM 10 TO 20
MPH TODAY...WHICH WILL BE LIGHTER THAN THE PAST SEVERAL DAYS.
REGARDING CHANCES FOR ANY SHOWERS OR THUNDERSTORMS...HAVE TRIMMED
WEST THE AREA TO MAINLY THE EASTERN PANHANDLE AND WESTERN CHERRY
COUNTY THIS AFTERNOON. THE NAM AND RAP MODELS ARE SIMILAR
TARGETING THESE AREAS. A DISTURBANCE TO MOVE THROUGH EASTERN
WYOMING AND THE BLACK HILLS REGION EARLY THIS AFTERNOON AND
SHOULD TRIGGER ISOLATED SHOWERS OR THUNDERSTORMS. THE STEEPER H7
TO H5 LAPSE RATES NEAR 7.5 C.KM WILL BE PERCENT IN THE PANHANDLE
AND SW NEBR THIS AFTERNOON. A DISTURBANCE BEHIND THE COLD FRONT
WILL TRIGGER SOME SHOWERS FROM EASTERN MONTANA INTO WESTERN AND
CENTRAL SOUTH DAKOTA TODAY. WHILE A FEW OF THESE SHOWERS COULD
MOVE INTO NORTH CENTRAL NEBRASKA THIS AFTERNOON...MODELS DO NOT
SUPPORT SUFFICIENT LIFT TO INTRODUCE A MENTION.
TONIGHT...CONTINUED A SLIGHT CHANCE FOR SHOWERS IN THE EASTERN
PANHANDLE AND WESTERN CHERRY COUNTY...WHICH SHOULD DISSIPATE BY
AROUND SUNSET. WITH A MILDER AIR MASS IN PLACE AND WEAK LOW
PRESSURE...TEMPERATURES WILL RANGE FROM THE UPPER 30S FAR
NORTHWEST TO THE LOWER 40S ELSEWHERE. SKIES WILL BE CLEARING IN
THE WEST WITH LINGERING CLOUDINESS ACROSS THE EAST.
SYNOPTICALLY...THE UPPER RIDGE IN THE WEST WILL FLATTEN OUT AS IT
MOVES INTO THE GREAT BASIN WHILE A CLOSED LOW MOVES INTO MANITOBA
AND WESTERN ONTARIO. THIS WILL KEEP THE COOLER AIR TO OUR NORTH
ACROSS THE DAKOTAS AND GREAT LAKES.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 341 AM CDT FRI MAY 2 2014
SATURDAY WILL SEE THE LOW PUSHING ACROSS THE NE PACIFIC...HEADING
FOR THE PACIFIC NW STATES. THIS WILL CAUSE THE HIGH ACROSS THE
DESERT SOUTHWEST TO PUSH EAST. MEANWHILE A LEE SIDE TROUGH WILL
DEVELOP. AS THE RIDGE SLIDING EAST...HEIGHTS INCREASE ACROSS THE
AREA. NAM HAS BEEN THE FASTEST WITH THE HEIGHT INCREASES...WHICH
HAS TRANSLATED TO MET GUIDANCE IN SW NEB INTO THE 80S. THE
SLIGHTLY SLOWER GFS/EC MOS GUIDANCE HAS HELD MOST SITES ACROSS SW
IN THE 70S. THE SW PART OF NEB DID SEE A QUARTER TO HALF AN INCH
WITH THIS LATE APRIL EVENT...HOWEVER THE MONTH ENDED 1 TO 2 INCHES
BELOW NORMAL. EXPECT THE RELATIVELY DRY SOILS TO AID IN WARMING
CLOSER TO THE MET GUIDANCE NUMBERS. ALTHOUGH LATELY THE WARMEST
GUIDANCE HAS BEEN THE WAY TO GO DURING THESE ABOVE NORMAL
DAYS...SO MAY NEED TO TREND THIS WARMER YET. MEANWHILE A SFC HIGH
WILL DIVE SOUTH INTO THE NORTHERN PLAINS. WHILE THE HIGH IS
CENTERED WELL NORTH OF THE AREA...COOLER AIR IN ASSOCIATION WITH
THE HIGH WILL PUSH INTO THE DAKOTAS AND PARTS OF NRN NEB. HIGHS ON
SAT ACROSS THE NORTH SHOULD WARM TO AROUND 70.
SATURDAY AFTERNOON STEEP LAPSE RATE DEVELOP ALONG THE LEE SIDE
TROUGH. WOULD EXPECT SOME SHOWERS TO DEVELOP DURING THE PEAK
HEAT...ALTHOUGH MOISTURE...DEW PTS IN THE 40S...MAY BE TOO DRY
FOR ANYTHING TO REACH THE GROUND. A BETTER CHANCE...ALBEIT ONLY
SLIGHTLY BETTER...WILL BE WITH A QUASI-STATIONARY BOUNDARY
BETWEEN THE COOLER NORTHERN HIGH AND WARMER SW SAT EVENING. AGAIN
MOISTURE IS A CONCERN AND RETAINED LOW POPS...ALTHOUGH NOT
LOOKING AS GOOD AS YESTERDAY AND SCALED BACK THE COVERAGE.
SUNDAY THE RIDGE CONTINUES TO ADVANCE EAST...BUT BECOMES MORE
BROAD. HIGHS AGAIN INTO THE 80S ACROSS SW WITH MORE CLOUDS ACROSS
THE NORTH...NEAR THE BOUNDARY...AND HIGHS IN THE 60S. SUNDAY
EVENING THE BOUNDARY LIFTS NORTH AND FORECAST AREA LOOKS DRY WITH
THE ACTIVITY NORTH OF THE BORDER.
BY MONDAY THE BROAD RIDGE AXIS WILL BE EAST WITH SW NEB DROPPING
TO AROUND 80. MORE SUN ACROSS THE NORTH AND HIGHS SHOULD BE ABLE
TO WARM ABOVE SUNDAY READINGS...CLOSER TO 70.
TUESDAY THROUGH THE THURSDAY A MORE ACTIVE PATTER IS SETTING UP.
THE NORTHEAST PACIFIC LOW WILL OPEN INTO A TROUGH AS IT DIGS INTO
THE 4 CORNERS REGION. THE GFS CONTINUES TO THEN EJECT THE LOW
ONTO THE CENTRAL PLAINS. THE ECMWF BREAKS UP THE LOW WITH A PIECE
PUSHING ONTO THE PLAINS WITH A SECONDARY LOW DEVELOPING OFF THE
COAST OF BAJA. EITHER WAY BOTH MODELS SUPPORT A CHANCE FOR
PRECIPITATION ACROSS THE AREA. THE GULF DOES OPEN UP...HOWEVER
THIS IS SHORT LIVED WITH A COLD FRONT TO PUSH ACROSS THE AREA AND
KEEP THE BULK OF THE MOISTURE SOUTH AND EAST OF THE AREA. TEMPS
COOL INTO THE 60S AND 70S...AND WILL CONTINUE TO MONITOR THE
MOISTURE PUSH NORTHWARD WHICH WILL EFFECT THE QPF AMOUNTS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 644 AM CDT FRI MAY 2 2014
CEILING AND VISIBILITY WILL BE UNLIMITED TODAY AND TONIGHT. A
FRONT COMMING ACROSS NEBRASKA WILL THEN BRING ISOLATED SHOWERS OR
THUNDERSTORMS TO NORTHWEST NEBRASKA...BUT THE PROBABILITY OF EITHER
OCCURRING AT ANY ONE SITE IS LESS THAN 20 PERCENT.
HOWEVER...CEILINGS OF 8000 FEET AGL ARE LIKELY.
WIND WILL INCREASE OVER MUCH OF THE AREA BY 16Z AND BECOME
290-320 AT 13G20KT BUT WILL BECOME VARIABLE THIS EVENING AT LESS
THAN 10KT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...MASEK
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1026 AM EDT FRI MAY 2 2014
.SYNOPSIS...
A PARADE OF UPPER LEVEL DISTURBANCES WILL SWING ACROSS THE GREAT
LAKE DURING THE NEXT FEW DAYS...AND THIS WILL CONTINUE TO PRODUCE
TIMES OF UNSETTLED WEATHER RIGHT THROUGH THE WEEKEND. A RETURN TO
TRUE FAIR WEATHER CAN BE EXPECTED EARLY NEXT WEEK WHEN CANADIAN HIGH
PRESSURE WILL BUILD ACROSS OUR REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR IMAGERY THIS MORNING SHOWING A PERSISTENT AREA OF SHOWERS
ACROSS THE HIGHER TERRAIN SOUTH OF BUFFALO AND ROCHESTER...AND ALSO
ACROSS THE HIGHER TERRAIN EAST OF LAKE ONTARIO. THIS IS DUE TO
COMBINED EFFECTS FROM UPSLOPE FLOW AND DPVA WITH THE PASSAGE OF A
WELL DEFINED MID LEVEL SHORTWAVE NOTED IN WATER VAPOR IMAGERY AND
OBJECTIVE RUC ANALYSIS. AS THE SHORTWAVE MOVES EAST OF THE AREA THIS
AFTERNOON EXPECT COVERAGE OF SHOWERS TO DECREASE ACROSS THE HIGHER
TERRAIN...ALTHOUGH IT MAY NOT GO AWAY ALTOGETHER WITH PLENTY OF LOW
LEVEL MOISTURE AND DAYTIME HEATING. A FEW SPOTTY SHOWERS MAY ALSO
DEVELOP THIS AFTERNOON JUST ABOUT ANYWHERE WITH DAYTIME HEATING AND
VERY LIMITED SURFACE BASED INSTABILITY. SOME WEAK LAKE SHADOWS MAY
TRY TO FORM NORTHEAST OF LAKES ERIE AND ONTARIO...BUT WITH THE
WEALTH OF CLOUD COVER THE LAKE SHADOWS MAY NOT BECOME OVERLY
APPARENT.
SPEAKING OF CLOUD COVER...RECENT SATELLITE TRENDS AND SHORT TERM
MODEL GUIDANCE SUGGEST LITTLE HOPE FOR MUCH IN THE WAY OF SUNSHINE
TODAY. THE ONE POSSIBLE EXCEPTION WILL BE ACROSS CENTRAL NY UP TO
WATERTOWN...WHERE ENOUGH BREAKS MAY DEVELOP TO ALLOW FOR SOME
LIMITED SUNSHINE THIS AFTERNOON. HIGH TEMPS WILL ONLY TOP OUT IN THE
LOW TO MID 50S IN MOST AREAS GIVEN THE COOL TEMPS ALOFT AND WEALTH
OF CLOUD COVER.
TONIGHT WILL THEN FEATURE GENERALLY DRY WEATHER AS THE SHORTWAVE
RIDGING WILL GRADUALLY PUSH EAST TO THE ADIRONDACKS AND NEW ENGLAND.
MEANWHILE ACROSS THE UPPER GREAT LAKES...THE NEXT ROBUST SHORTWAVE
WILL BE TAKING AIM ON OUR REGION. THE LEADING EDGE OF THE PCPN
ASSOCIATED WITH THIS FEATURE COULD REACH PARTS OF OUR REGION TOWARDS
DAYBREAK. MINS TONIGHT WILL LARGELY BE IN THE LOWER 40S.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
IT WILL BE THE SAME OLD STORY THROUGH THE WEEKEND AS MID AND UPPER
LEVEL TROUGHING WILL PERSIST ACROSS THE GREAT LAKES AND NORTHEAST...
WITH THE RESULTANT LARGE-SCALE CYCLONIC FLOW SENDING ADDITIONAL
SHORTWAVE IMPULSES SOUTHEASTWARD ACROSS OUR REGION. THE FIRST SUCH
IMPULSE WILL ARRIVE SOMETIME DURING SATURDAY MORNING...WITH A SECOND
AND STRONGER FEATURE WORKING INTO THE AREA DURING THE AFTERNOON.
COUPLED WITH STEEPENING LAPSE RATES DUE TO DIURNAL WARMING OF OUR
COOL AIRMASS...THESE FEATURES SHOULD BRING INCREASING CHANCES OF
SHOWERS THROUGH THE DAY...WITH THESE PEAKING DURING THE AFTERNOON
HOURS WITH THE APPROACH OF THE SECOND AND STRONGER SHORTWAVE...AND
WHEN DIURNALLY-DRIVEN INSTABILITY WILL BE THE GREATEST. AT THIS
POINT...IT APPEARS THERE MAY EVEN BE ENOUGH INSTABILITY PRESENT FOR
SOME OF THE ACTIVITY TO GET STRONG ENOUGH TO PRODUCE SOME GRAUPEL
AND POSSIBLY EVEN A LITTLE LIGHTNING AND THUNDER. WITH ALL OF THIS
IN MIND...HAVE INSERTED A SLIGHT CHANCE OF THUNDER INTO THE GRIDS
FOR SATURDAY AFTERNOON.
LATER ON IN THE WEEKEND...A SIMILAR SCENARIO MAY WELL UNFOLD LATE
SATURDAY NIGHT INTO SUNDAY AS AN EVEN STRONGER SHORTWAVE DROPS
SOUTHEASTWARD ACROSS NEW YORK STATE...THOUGH THE VARIOUS GUIDANCE
PACKAGES CONTINUE TO SHOW SOME SUBTLE DIFFERENCES ON THE EXACT TRACK
OF THIS FEATURE...WHICH WILL HAVE AN INFLUENCE ON EXACTLY WHICH
AREAS WILL BE MOST LIKELY TO SEE PRECIPITATION. AT THIS POINT...THE
NORTH COUNTRY APPEARS TO BE THE AREA MOST PRONE TO ANOTHER ROUND OF
SHOWERS...THOUGH MOST LOCATIONS SOUTH OF LAKE ONTARIO SHOULD ALSO
SEE A LIKELIHOOD OF A FEW SHOWERS AT SOME POINT DURING THE DAY.
AFTER THAT...EXPECT SHOWER CHANCES TO WANE FROM WEST TO EAST SUNDAY
NIGHT WITH NOCTURNAL STABILIZATION OF THE LOWER LEVELS AND THE
DEPARTURE OF THE SHORTWAVE TO OUR EAST...THOUGH SOME LEFTOVER
SCATTERED ACTIVITY MAY WELL LINGER INTO MONDAY MORNING ACROSS THE
NORTH COUNTRY THANKS TO LINGERING TROUGHING ALOFT. OTHERWISE...
EXPECT MONDAY TO BE A GENERALLY DRY DAY AS SURFACE HIGH PRESSURE
RIDGES SOUTHEASTWARD FROM ONTARIO PROVINCE.
AS FOR TEMPS...THESE WILL CONTINUE TO AVERAGE A BIT BELOW NORMAL
RIGHT THROUGH THE PERIOD GIVEN THE LINGERING TROUGHING ALOFT...AND
THE RESULTANT PERSISTENT NORTHWESTERLY FLOW OF SEASONABLY COOL AIR
ACROSS OUR REGION.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATEST MEDIUM RANGE GUIDANCE CONTINUES TO SUGGEST THAT LINGERING
UPPER LEVEL TROUGHING OVER EASTERN NORTH AMERICA AT THE START OF THE
PERIOD WILL GIVE WAY TO INCREASING RIDGING ALOFT AS A NEW LARGE-
SCALE TROUGH DEVELOPS OVER THE WESTERN THIRD OF THE CONTINENT. THIS
SHOULD RESULT IN OUR TEMPERATURES EVENTUALLY RETURNING BACK TO NEAR
NORMAL LEVELS BY WEDNESDAY...THEN CLIMBING BACK ABOVE NORMAL ON
THURSDAY AS A DEVELOPING CYCLONE OVER THE PLAINS STATES HELPS PUMP
EVEN WARMER AIR NORTHEASTWARD INTO THE OHIO VALLEY AND NORTHEAST.
IN TERMS OF PRECIPITATION CHANCES...PERSISTENT SURFACE-BASED RIDGING
DRAPED FROM CENTRAL AND EASTERN CANADA SOUTHEASTWARD INTO THE GREAT
LAKES AND NORTHEAST SHOULD KEEP MAINLY DRY CONDITIONS INTACT ACROSS
OUR AREA THROUGH WEDNESDAY. AFTER THAT TIME...THE AFOREMENTIONED LOW
PRESSURE SYSTEM OVER THE PLAINS WILL PUSH A WARM FRONT IN OUR
DIRECTION WEDNESDAY NIGHT AND THURSDAY...WITH INCREASING WARMTH AND
MOISTURE ALONG THIS FEATURE BRINGING A RENEWED RISK FOR SOME
SHOWERS.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS WILL BE FAIRLY WIDESPREAD THROUGH MIDDAY...WITH A FEW
HOURS OF IFR CIGS NOT OUT OF THE QUESTION ACROSS THE HIGHER TERRAIN
OF THE SRN TIER. NUMEROUS SHOWERS ACROSS THE HIGHER TERRAIN OF THE
SOUTHERN TIER AND FINGER LAKES AND ALSO EAST OF LAKE ONTARIO WITH
LOCAL MVFR/IFR VSBY WILL BECOME MORE WIDELY SCATTERED THIS
AFTERNOON...WITH ADDITIONAL WIDELY SCATTERED SHOWERS POSSIBLE JUST
ABOUT ANYWHERE THIS AFTERNOON. CIGS WILL GRADUALLY LIFT DURING THE
MIDDAY AND EARLY AFTERNOON...LEAVING VFR CIGS FOR THE BULK OF THE
AFTERNOON INTO THE EVENING.
LATER TONIGHT...CIGS WILL LIKELY RETURN TO MVFR LEVELS AS THE NEXT
FEATURE WILL APPROACH FROM THE UPPER GREAT LAKES.
OUTLOOK...
SATURDAY AND SUNDAY...VFR/MVFR WITH SCATTERED TO OCCASIONALLY MORE
NUMEROUS SHOWERS.
MONDAY AND TUESDAY...VFR.
&&
.MARINE...
WHILE ONLY A MODESTLY STRONG SFC PRESSURE GRADIENT WILL BE IN PLACE
ACROSS THE LOWER GREAT LAKES TODAY...THERE WILL BE ENOUGH DIURNAL
MIXING TO TRANSPORT SOME OF THE STRONGER WINDS FROM ALOFT DOWN TO
THE LK SFC. THIS WILL ESPECIALLY BE THE CASE OVER LAKE ERIE...WHERE
WINDS WILL ONCE AGAIN REACH SMALL CRAFT ADVISORY CRITERIA. WILL
ISSUE ANOTHER SCA FOR THE NEW YORK NEARSHORES OF LK ERIE ONLY...AS
A FAIR AMOUNT OF ICE REMAINS IN BUF HARBOR. AS FOR LK ONTARIO...
MODERATE SOUTHWESTERLIES SHOULD NOT GENERATE SIGNIFICANT WAVES SO NO
FLAGS WILL BE NEEDED.
WINDS AND WAVES WILL SUBSIDE TONIGHT GIVEN THE DIURNAL UNCOUPLING
FROM WINDS ABV 1500 FT.
ON SATURDAY...WHILE THE NEXT UPPER LEVEL DISTURBANCE WILL BRING
ANOTHER ROUND OF SHOWERS TO THE LOWER GREAT LAKES...A RELATIVELY
WEAK SOUTHERLY FLOW IS ANTICIPATED. WINDS WILL FRESHEN SIGNIFICANTLY
SATURDAY NIGHT AND SUNDAY THOUGH...WHEN THE NEXT ROUND OF SMALL
CRAFT ADVISORIES WILL LIKELY BE NEEDED.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LEZ040-
041.
&&
$$
SYNOPSIS...RSH
NEAR TERM...HITCHCOCK/RSH
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...HITCHCOCK/RSH
MARINE...RSH
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
911 AM MDT FRI MAY 2 2014
.UPDATE...
ISSUED AT 903 AM MDT FRI MAY 2 2014
15Z SURFACE ANALYSIS HAD COOL FRONT FROM KBWP TO KCUT TO
KBIL...SLOWLY SINKING SOUTH. SHORTWAVE ENERGY NOTED ON WATER
VAPOUR ACROSS SOUTHERN AB/SK...SLINKING SOUTHEAST ON 90KT UPPER
LEVEL JET. REGIONAL RADAR LOOP HAD POST FRONTAL SHRA ASSOCIATED
WITH SHORTWAVE ENERGY AND STEEP LAPSE RATES PER 12Z KUNR SOUNDING
AND SATURATED MID-LEVEL 12Z KGGW SOUNDING. 12Z RAP SHOWED CURRENT
ACTIVITY WELL...AND IT SPREADS SHRA ACROSS THE MAJORITY OF THE CWA
THROUGH THIS AFTERNOON/EARLY THIS EVENING AND HAVE ADJUSTED
SCATTERED POPS TO MATCH. WHERE BETTER DIURNAL HEATING
OCCURS...NORTHEAST WY/SOUTHWEST SD...HAVE KEPT TS MENTION GIVEN
250J/KG MUCAPE AVAILABLE DURING PEAK HEATING. HAVE ALSO ADJUSTED
TEMPERATURES FOR HIGHER CLOUD COVER.
&&
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 303 AM MDT FRI MAY 2 2014
LEAD UPPER LEVEL IMPULSE IN NW FLOW...ADVECTING SE
ACROSS THE NORTHERN HIGH PLAINS...WITH AN ASSOCIATED SFC TROUGH NOW
ENTERING NW SD /08Z/. THIS SFC TROUGH WILL SAG SOUTH ACROSS THE FA
TODAY...WITH IMPULSE LADED NW FLOW SUPPORTING CHANCES FOR SHRA
ACROSS THE REGION. LL FRONTAL ZONE WILL WAVER N-S ACROSS THE REGION
AS A SERIES OF IMPULSES ADVECT QUICKLY SE THROUGH THE FLOW. DEGREE
OF CAA UNDER THE SOUTHERN CANADIAN HEIGHT ANOMALY LOOKS TO BE MUCH
STRONGER THAN PREVIOUS MODEL RUNS HAVE INDICATED...SUPPORTING A
SOUTH BIAS TO THE SFC COLD FRONT IN THE PERIOD. THIS WOULD TEND TO
SUPPORT SLIGHTLY COOLER CONDITIONS ACROSS THE NW HALF...ESP SAT.
TODAY/TONIGHT...SFC TROUGH WILL SAG SOUTH INTO THE FA...BEHIND THE
LEAD IMPULSE. SECONDARY IMPULSE ON THE HEALS OF HE FIRST WILL
SUPPORT A WEAK HIGH CENTERED FGEN RESPONSE WITH SHRA ACTIVITY
SPREADING SOUTH INTO NW SD. FORECAST MODELS HAVE BEEN HIGHLY
CHANGEABLE PER QPF AMOUNTS ACROSS THE NW...BACKING OFF SIG WITH THE
LATEST RUNS TO MORE REASONABLE VALUES GIVEN LIFT PROFILES. COOLER
TEMPS EXPECTED THERE GIVEN CLOUDS/PRECIP AND WEAK CAA. FURTHER
SOUTH...DIURNAL HEATING WITH THE PASSING WEAK IMPULSE SHOULD BE
ENOUGH FOR A FEW ISOLD SHRA/TS BY AFTERNOON. KEPT POPS GENERALLY
LOW /SAVE THE FAR NW/ AS THE MAIN LOBE ASCENT WILL REMAIN NORTH OF
THE REGION. RETAINED TS CHANCES OVER THE SW WHERE NEGATIVE LI/POS MU
CAPE/AND DECENT HEATING IS EXPECTED. ANOTHER WEAK WAVE MAY SUPPORT A
FEW SHOWERS OVERNIGHT...WITH LOW POPS RETAINED ACROSS THE NW.
SATURDAY...LL BAROCLINIC ZONE WITH ACTIVE NW FLOW WILL PERSIST
SUPPORTING LOW CHANCES FOR SHRA IN THE PERIOD. RETAINED LOW
POPS...MAINLY NW AREAS FOR EXPECTED PASSING IMPULSES...OF WHICH
TIMING/STRENGTH REMAIN MUDDLED. ADJUSTED TEMPS...WITH A STRONG
NE/SW TEMP GRADIENT EXPECTED ACROSS THE FA. LOCATIONS NEAR THE
GENERAL AREA OF THE FRONT WILL HAVE THE POTENTIAL TO SEE
COOLER/WARMER TEMPS...WHICH WILL HINGE ON THE STRENGTH OF PASSING
IMPULSES AND THEIR REFLECTED N-S FRONTAL PERTURBATION.
&&
.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 303 AM MDT FRI MAY 2 2014
WEST TO SWRLY FLOW OVER THE REGION WILL START THE WEEK
WITH A VARIETY OF WEAK DISTURBANCES MOVING THROUGH...BRINGING PRECIP
CHANCES TO THE AREA. TOWARDS MID-WEEK DEEP TROF PUSHES TOWARDS THE
ROCKIES WITH STRONGER SWRLY FLOW DEVELOPING BRINGING GREATER
SHOWER/THUNDERSTORM CHANCES.
&&
.AVIATION...FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING
ISSUED AT 303 AM MDT FRI MAY 2 2014
SCT -SHRA WITH ISOLD AFTERNOON AND EVENING -TSRA ARE
EXPECTED THRU THE FORECAST PERIOD. LCL MVFR VIS WILL BE POSSIBLE IN
PRECIP.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...HELGESON
SHORT TERM...JC
LONG TERM...77
AVIATION...77
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
644 AM CDT FRI MAY 2 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 240 AM CDT FRI MAY 2 2014
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO BRITISH COLUMBIA...AN
UPPER LOW AND SHORTWAVE TROUGH OVER NORTHERN ALBERTA/SASKATCHEWAN...
A SHORTWAVE TROUGH OVER SOUTHERN MANITOBA...AND AN ELONGATED LONG
WAVE TROUGH FROM TEXAS INTO THE GREAT LAKES. THE FORECAST AREA LIES
NOW IN SUBSIDENCE IN THE WAKE OF THE LONG WAVE TROUGH...PROMOTING
DRY AIR ADVECTION FROM THE NORTHWEST. THIS CAN BE SEEN BY THE LOW
STRATUS DECK CLEARING ACROSS MINNESOTA ON 11-3.9UM IMAGERY AND
SURFACE OBSERVATIONS. 00Z BIS AND ABR SOUNDINGS WERE ALSO QUITE DRY
WITH PRECIPITABLE WATER OF ONLY 0.3-0.4 INCHES. REPLACING THE
STRATUS DECK HAS BEEN MID AND HIGH CLOUDS SPREADING SOUTHEAST ACROSS
THE DAKOTAS AND MINNESOTA...AHEAD OF THE SHORTWAVE THERE. GRAND
FORKS RADAR DISPLAYING SOME LIGHT RETURNS AS WELL...BUT SO FAR THE
DRY AIR HAS BEEN WINNING OUT KEEPING THE PRECIPITATION AS VIRGA.
AIRMASS OVER THE FORECAST AT 00Z WAS STILL UNSEASONABLY COOL WITH
925MB TEMPS AROUND 4C...BUT WARMER 9-13C READINGS WERE LURKING
UPSTREAM AT ABR AND BIS. BEHIND THE SHORTWAVE TROUGH IN SOUTHERN
MANITOBA...SKIES CLEAR OUT AND SURFACE PRESSURES WERE RISING ABOUT 1
MB/HR...PROMOTING GUSTY WINDS ACROSS NORTH DAKOTA.
MODELS ARE IN GOOD AGREEMENT DROPPING THE SOUTHERN MANITOBA
SHORTWAVE SOUTHEASTWARD THROUGH THE FORECAST AREA THIS AFTERNOON.
MORE IMPORTANTLY...THERE IS A CONSISTENT SIGNAL FROM ALL MODELS FOR
THE SHORTWAVE TO WEAKEN SOME. THIS WEAKENING COMBINED WITH THE DRY
ADVECTION CURRENTLY TAKING PLACE FROM THE NORTHWEST BRINGS IN SOME
CONCERN FOR PRECIPITATION CHANCES TODAY. HARD TO FIND A MODEL THAT
DOESNT PRECIPITATE WITH THE SHORTWAVE...WHICH MAKES SENSE IN
GENERAL GIVEN WE HAVE A SHORTWAVE TROUGH COMING THROUGH AT PEAK
HEATING. BETWEEN DYNAMICS AND INSTABILITY FROM HEATING...SHOWERS
DEVELOPING IS REASONABLE. HOWEVER...IT IS WORTH NOTING THAT 2 METER
DEWPOINT GUIDANCE FROM THE BASE MODELS SUCH AS THE ECMWF...GFS...NAM
AND REGIONAL CANADIAN ALL PUSH DEWPOINTS WELL INTO THE 40S...WITH
EVEN THE GFS AND REGIONAL CANADIAN APPROACHING 50 BY 00Z. THIS SEEMS
A BIT HIGH GIVEN CURRENT SURFACE DEWPOINTS IN THE UPPER 20S TO MID
30S OVER THE DAKOTAS. PERHAPS THE MODELS ARE THINKING GREEN-UP HAS
ALREADY TAKEN PLACE BASED ON CLIMATOLOGY. WE DO HAVE WET SOILS SO
THAT COULD PROMOTE SLIGHTLY HIGHER DEWPOINTS. IN SUMMARY...FEEL
FAIRLY CONFIDENT THAT WE WILL SEE SHOWERS THIS AFTERNOON...BUT A
LITTLE LESS CERTAIN ON IF THEY WILL BE WIDESPREAD. ANOTHER CHANGE
WORTH NOTING IS THAT THE 02.00Z NAM MUCAPE THIS AFTERNOON HAS
DROPPED FROM PREVIOUS RUNS...NOW BELOW 200 J/KG...WHICH MAKES SENSE.
CONSIDERED DROPPING THE THUNDER MENTION ENTIRELY AS A RESULT...BUT
THE RAP DOES DEPICT A ZONE OF 700-500MB LAPSE RATES APPROACHING 7
C/KM OVER THE FORECAST AREA DURING THE AFTERNOON. THEREFORE...HAVE
LEFT THE THUNDER IN THE FORECAST FOR THE AFTERNOON. ANY SHOWER
ACTIVITY SHOULD QUICKLY EXIT THE AREA BETWEEN 00-03Z WITH THE
SHORTWAVE EXITING AND DIURNAL COOLING.
AS WE APPROACH LATE TONIGHT...MORE SHOWER ACTIVITY LOOKS TO DROP
DOWN INTO NORTHERN MN AND WI. THESE ARE AHEAD OF THE SHORTWAVE
TROUGH AND UPPER LOW CURRENTLY IN NORTHERN ALBERTA/SASKATCHEWAN...
PROGGED TO BE OVER SOUTHERN MANITOBA AND NORTHERN MN BY 12Z
SATURDAY. ITS POSSIBLE THIS SHOWER ACTIVITY COULD GET INTO TAYLOR
COUNTY TOWARDS 12Z...BUT FOR NOW HAVE KEPT THE FORECAST DRY.
925MB TEMPERATURES ARE PROGGED A FEW DEGREES WARMER TODAY...BETWEEN
6-8C FOR THE AFTERNOON HOURS. THERE IS A CHANCE WE CAN SNEAK IN A
LITTLE SUN AND WITH A WARM ADVECTING SOUTHWEST WIND...MOST LOCATIONS
WILL CLIMB INTO THE 50S. THERES EVEN A CHANCE SOME SPOTS COULD PUSH
60...SUCH AS CHARLES CITY...WINONA...LA CROSSE AND BOSCOBEL. THIS
ALL HINGES IF WE CAN GET MORE SUN...BUT THINK OVERALL WE WILL BE
CLOUDY OR MOSTLY CLOUDY TODAY. COLD ADVECTION TONIGHT ON A NORTHWEST
WIND...WHICH COULD BE BRISK IN THE EVENING WEST OF THE MS RIVER WITH
THE PRESSURE RISE COMING THROUGH...WILL ALLOW TEMPERATURES TO DROP
INTO THE 30S TO LOW 40S TONIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 240 AM CDT FRI MAY 2 2014
UPPER LEVEL PATTERN CHANGE REMAINS ON TRACK DURING THE LONG TERM
PERIOD...WITH UPPER RIDGING CURRENTLY OVER THE WESTERN U.S. PROGGED
TO BUILD OVER THE REGION LATE TUESDAY INTO WEDNESDAY. THIS IS ALL IN
RESPONSE TO AN UPPER LOW CURRENTLY OFF THE PACIFIC NORTHWEST COAST
SUGGESTED TO DIG INTO THE SOUTHWESTERN U.S.. THIS PATTERN CHANGE
MEANS A GRADUAL MODERATION OF TEMPERATURES...ALONG WITH POTENTIAL
FOR MORE ACTIVE WEATHER AS WE APPROACH THE MIDDLE OF NEXT WEEK.
FIRST OFF...SATURDAY. THAT NEXT SHORTWAVE TROUGH AND UPPER LOW
CURRENTLY IN NORTHERN ALBERTA/SASKATCHEWAN WILL SLIDE ACROSS
NORTHERN PORTIONS OF MN AND WI...ALONG WITH UPPER MI AND ONTARIO
DURING THE DAY AND EVENING HOURS. THIS TRACK KEEPS THE BEST DPVA
FORCING NORTH OF THE FORECAST AREA. THEREFORE...THINK MUCH OF THE
PRECIPITATION WILL STAY NORTH AS WELL. HOWEVER...THERE WILL BE A
SURFACE COLD FRONT ACCOMPANYING THE SHORTWAVE. THE 02.00Z GFS PRINTS
OUT SOME LIGHT QPF OVER LA CROSSE AS THE FRONT COMES THROUGH...
MOSTLY A RESULT OF THE MODEL DEVELOPING SOME WEAK CAPE. BELIEVE THE
MODEL IS TOO FAR SOUTH AND OVERLY MOIST. HAVE DECIDED TO KEEP ANY
LOW CHANCES OF PRECIPITATION NORTH OF I-94...CONSISTENT TOO WITH THE
02.00Z ECMWF. 925MB TEMPS REBOUND DECENTLY ON SATURDAY...6-9C...
ALLOWING TEMPERATURES TO CLIMB SLIGHTLY HIGHER THAN THOSE TODAY.
NEXT UP IS ON SUNDAY WHERE THE 02.00Z GFS/CANADIAN/ECMWF/NAM ALL
DEVELOP A FRONTOGENETICAL BAND OF PRECIPITATION. THE BAND ALSO HAS
SOME RIGHT ENTRANCE REGION FORCING FROM A JET STREAK FOLLOWING THE
SATURDAY SHORTWAVE TROUGH. THE NAM IS THE ODD MODEL OUT ON LOCATION
OF THE BAND...TRACKING IT FROM MINNEAPOLIS TO LA CROSSE AND THE
DELLS...WHEREAS ALL OTHER MODELS SUGGEST SOUTHWEST MN INTO NORTHERN
IA AND NORTHERN IL AS THE MORE LIKELY TRACK. GIVEN GOOD AGREEMENT ON
THIS FRONTOGENETIC BAND FROM THE OTHER MODELS...HAVE RAISED
PRECIPITATION CHANCES. MODEL CONSENSUS SUGGESTS 12-18Z SUNDAY IS THE
MOST LIKELY TIME PERIOD FOR PRECIPITATION WITH THE PRECIPITATION
EXITING RAPIDLY TO THE SOUTHEAST IN THE AFTERNOON. THERE IS SOME
LOWER LEVEL DRY AIR PRESENT...WHICH IF THE PRECIPITATION WAS HEAVIER
MIGHT CAUSE PRECIPITATION TYPE ISSUES FROM EVAPORATIVE COOLING. FOR
NOW WILL KEEP THE PRECIPITATION TYPE AS RAIN GIVEN GENERALLY LIGHT
QPF PROGGED BUT SOMETHING TO WATCH. WITH THIS FRONTOGENETICAL BAND
GOING THROUGH AND A NORTHEAST BREEZE...TEMPERATURES ARE GOING TO
TAKE A COOL DOWN. THIS IS ESPECIALLY TRUE UNDER THE PRECIPITATION.
RAIN CHANCES COME BACK FOR MONDAY WHEN YET ANOTHER BAND OF
FRONTOGENESIS AND ISENTROPIC LIFT MOVES ACROSS. THIS ONE LOOKS
WEAKER THAN ON SUNDAY...THUS 02.00Z GFS/CANADIAN/ECMWF QPF IS
LIGHTER AND MORE SPREAD OUT ACROSS THE FORECAST AREA. CONSENSUS 20
PERCENT CHANCES SEEM REASONABLE. COOLED HIGHS SLIGHTLY FROM THE
PREVIOUS FORECAST DUE TO CLOUDS AND AN EAST WIND AROUND HIGH
PRESSURE IN UPPER MI. THESE COULD NEED FURTHER COOLING IF A LITTLE
MORE PRECIPITATION IS AROUND AS SUGGESTED BY THE 02.00Z ECMWF.
AS THE UPPER RIDGE BUILDS INTO THE AREA LATE TUESDAY AND ESPECIALLY
WEDNESDAY...THAT IS WHEN SOME BIGGER TEMPERATURE CHANGES TAKE
PLACE...ALONG WITH INCREASING CONCERNS FOR CONVECTION AND POSSIBLE
SEVERE WEATHER. 02.00Z GFS/ECMWF SUGGEST THAT BETWEEN 12Z WEDNESDAY
AND 00Z THURSDAY...925MB TEMPS COULD CLIMB AS MUCH AS 10-15C
RESULTING IN AN ALMOST SUMMER-LIKE AIRMASS COMING INTO LOCATIONS
ALONG AND SOUTH OF I-90. WE WILL HAVE TO WAIT AND SEE HOW THIS PANS
OUT. IN ANY EVENT...HAVE FOLLOWED CONSENSUS WITH 30-50 PERCENT
CHANCES FOR TUESDAY NIGHT AND WEDNESDAY...WITH SLIGHTLY HIGHER
CHANCES FOR WEDNESDAY NIGHT INTO THURSDAY RESULTING FROM A SHORTWAVE
TROUGH COMING THROUGH THE UPPER MIDWEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 644 AM CDT FRI MAY 2 2014
THE MVFR CEILINGS ACROSS WEST-CENTRAL...CENTRAL...AND SOUTHWEST
WISCONSIN AND PARTS OF NORTHEAST IOWA WILL BECOME VFR BETWEEN
02.13Z AND 02.15Z....AND THEN REMAIN VFR THROUGH THE REMAINDER OF
THE PERIOD.
A BAND OF SHOWERS AND ISOLATED THUNDERSTORMS WILL MOVE THROUGH THE
TAF SITES BETWEEN 02.18Z AND 03.02Z. THESE SHOWERS MAY BRIEFLY
PRODUCE MVFR VISIBILITIES.
AS THE COLD FRONT MOVES THROUGH THE AREA THIS EVENING...THE WINDS
WILL SHIFT TO NORTHWEST. THIS WILL OCCUR AT KRST AROUND 03.02Z AND
KLSE AROUND 03.03Z. SKIES WILL CLEAR ABOUT 2 TO 3 HOURS AFTER THE
FRONTAL PASSAGE.
&&
.HYDROLOGY...
ISSUED AT 240 AM CDT FRI MAY 2 2014
RUNOFF FROM RECENT RAIN CONTINUES TO FLOW THROUGH THE MISSISSIPPI
RIVER TRIBUTARIES AND THE MAIN CHANNEL. CURRENTLY ONLY THE
MISSISSIPPI RIVER AT WABASHA IS IN FLOOD...BUT FORECASTS CONTINUE
TO POINT TO THE MISSISSIPPI RIVER AT WINONA...LA CROSSE...MCGREGOR
AND GUTTENBERG DAM 10 TO BEGIN MINOR FLOODING IN THE NEXT 1 TO 4.5
DAYS. IN ADDITION...THE BLACK RIVER AT GALESVILLE IS APPROACHING
FLOOD STAGE...BUT SHOULD NOT CLIMB MUCH ABOVE MINOR FLOOD WITH
FALLING RIVER LEVELS AT BLACK RIVER FALLS. NO MAJOR RAINS ARE
ANTICIPATED OVER THE NEXT 5 DAYS SO RUNOFF WILL BE THE MAIN
CONTRIBUTING FACTOR TO RIVER LEVELS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
325 PM EDT FRI MAY 2 2014
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL DEVELOP OFFSHORE TONIGHT AND PULL
AWAY FROM THE REGION. HIGH PRESSURE WILL THEN BUILD ACROSS THE
SOUTHEAST STATES AND EVENTUALLY INTO THE WESTERN ATLANTIC SUNDAY
THROUGH MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THIS EVENING AND TONIGHT...CURRENT REGIONAL RADAR TRENDS CONTINUE TO
SHOW THE STREAM OF RAINFALL ASSOCIATED WITH THE UPPER JET DIVERGENCE
AND THE PLUME OF DEEP MOISTURE WILL REMAIN OFFSHORE. INLAND AREAS
ARE EXPECTED TO STAY DRY...WITH JUST A SLIGHT CHANCE FOR PERIODIC
SHOWERS. ANYTHING THAT DOES FALL WILL PRODUCE LITTLE TO NO
MEASURABLE RAINFALL AND WILL ORIGINATE OUT OF MAINLY MID LEVEL
CLOUDS. AREAS ALONG THE COAST STAND A BIT OF A BETTER CHANCE OF
SEEING MEASURABLE RAIN...BUT EVEN HIGHER RESOLUTION MODELS SUCH AS
THE RAP KEEP THESE AREAS LARGELY DRY. THE HIGHER POPS ARE CONFINED
TO THE ADJACENT COASTAL WATERS WITH A DRY FORECAST IN PLACE BY LATE
TONIGHT. THE ELONGATED MID/UPPER LEVEL TROUGH TO THE WEST WILL
FINALLY BEGIN TO MOVE EASTWARD TONIGHT...WHICH WILL NUDGE THE DEEP
MOISTURE FEED FURTHER OFFSHORE. MODEL TIME HEIGHTS AND SOUNDINGS
SHOW THAT A SOLID MID/UPPER LEVEL CLOUD DECK WILL STICK AROUND FOR
MUCH OF THE NIGHT. WE MAY START TO SEE SOME THINNING AND SCATTERING
VERY LATE...BUT AT LEAST MOSTLY CLOUDY SKIES ARE EXPECTED. LOWS WILL
BE COOLER THAN PREVIOUS NIGHTS...BUT THE EXTENSIVE CLOUD COVER WILL
KEEP TEMPERATURES UP A BIT. LOOK FOR LOWS TO FALL INTO THE LOW 50S
INLAND...RANGING TO THE MID TO UPPER 50S ALONG THE COAST.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...THIS WILL BE A TRANSITION DAY AS THE ELONGATED UPPER TROUGH
AXIS SHIFTS OFF THE EASTERN SEABOARD...BRINGING CLEARING
SKIES...WARMER TEMPERATURES...AND RAIN FREE CONDITIONS TO THE REGION.
THERE WILL STILL BE SOME LINGERING WEAK COLD ADVECTION WHICH COULD
KEEP AFTERNOON HIGH TEMPERATURES JUST BELOW SEASONAL NORMALS...BUT
OVERALL EXPECT TEMPERATURES TO CLIMB INTO THE MID TO UPPER 70S. A
RELATIVELY WEAK FLOW AND CLEAR SKIES WILL ALLOW OVERNIGHT
TEMPERATURES TO DIP INTO THE LOWER 50S INLAND AND UPPER 50S ALONG
THE COAST.
SUNDAY THROUGH MONDAY...EXPECT RISING HEIGHTS AS A BROAD UPPER RIDGE
BUILDS EASTWARD ACROSS THE CENTRAL UNITED STATES. AT THE
SURFACE...HIGH PRESSURE WILL NUDGE INTO THE REGION FROM THE
WEST...RESULTING IN PLENTY OF SUNSHINE AND A CONTINUED WARMING
TREND. HIGH TEMPERATURES ARE EXPECTED TO CLIMB ABOVE SEASONAL
NORMALS WITH MID 80S ON SUNDAY AND UPPER 80S ON MONDAY. IN
FACT...THICKNESS VALUES SUGGEST TEMPERATURES NEAR 90 DEGREES WILL BE
POSSIBLE ON MONDAY. SUNDAY NIGHT TEMPERATURES WILL ALSO REFLECT THIS
WARMING TREND WITH LOWS IN THE UPPER 50S INLAND AND MID 60S ALONG
THE COAST.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A BROAD UPPER LEVEL RIDGE WILL DOMINATE THE EASTERN UNITED STATES
PATTERN FOR MUCH OF THE EXTENDED PERIOD...MAINTAINING UNSEASONABLY
WARM TEMPERATURES AND DRY CONDITIONS. TEMPS WILL MODERATE SLIGHTLY
BY LATE NEXT WEEK AS THE UPPER RIDGE BEGINS TO BREAK DOWN. WE ARE
NOW SHOWING HIGHS IN THE UPPER 80S TO NEAR 90 TUESDAY THROUGH
THURSDAY...THEN MIDDLE 80S ON FRIDAY. WE WILL PROBABLY NOT BREAK ANY
RECORD HIGHS SINCE THEY ARE ALL IN THE MIDDLE 90S FOR OUR THREE
CLIMATE SITES NEXT WEEK.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH 18Z SATURDAY. THERE MAY BE A
BRIEF PERIOD OF LIGHT RAIN AT EITHER SITE IN THE NEXT FEW
HOURS...BUT NOTHING WITH ENOUGH INTENSITY TO DECREASE
VISIBILITIES. A SOLID MID LEVEL DECK WILL STAY IN PLACE AND THEN
CLEAR OUT STARTING TOMORROW MORNING.
EXTENDED AVIATION OUTLOOK...VFR.
&&
.MARINE...
TONIGHT...QUIET CONDITIONS WILL CONTINUE ESPECIALLY EARLY IN THE
PERIOD. WINDS WILL BE LIGHT AND VARIABLE EARLY ON...BEFORE
INCREASING AND MORE WESTERLY LATE AS A WEAK SURFACE LOW RIDES
NORTHEASTWARD ALONG THE FRONT TO THE EAST. THIS INCREASE WILL BE
QUITE MODEST HOWEVER...WITH SPEEDS 15 KT OR LESS. SEAS WILL BE 2 FT
WITHIN 20 NM AND 2-3 FT BEYOND.
SATURDAY THROUGH WEDNESDAY...A PASSING UPPER LEVEL TROUGH WILL
ELEVATE WINDS SLIGHTLY SATURDAY...BUT OVERALL EXPECT RATHER TRANQUIL
CONDITIONS TO PERSIST ACROSS THE MARINE AREA. IN FACT...THIS BRIEF
SURGING WILL STILL REMAIN BELOW SMALL CRAFT LEVELS. THROUGH MID
WEEK...EXPECT WINDS 15 KNOTS OR LESS WITH SEAS 1 TO 2 FEET ACROSS
THE NEAR SHORE WATERS AND NO MORE THAN 4 FEET ACROSS THE OUTER
GEORGIA WATERS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...BSH
SHORT TERM...JHP
LONG TERM...JRL
AVIATION...BSH
MARINE...BSH/JHP
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
400 PM CDT FRI MAY 2 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 355 PM CDT FRI MAY 2 2014
AFTERNOON SATELLITE IMAGERY SHOWING ABUNDANT CLOUD COVER ACROSS THE
EASTERN HALF OF THE FA...WHILE WESTERN MINNESOTA WAS DRYING OUT
UNDER PARTY CLOUDY SKIES. AN UPPER LEVEL SHORTWAVE OVERHEAD THIS
AFTERNOON...QUICKLY MOVED IN TO ONLY ALLOW A SHORT TEASE OF BLUE
SKIES BETWEEN THE RESIDUAL CLOUD COVER FROM THE LOW THAT HAD STALLED
OVER THE AREA EARLY THIS WEEK...AND THE CLOUD COVER AND SCATTERED
SHOWERS PRODUCED BY A DECENT PV ANOMALY MOVING ACROSS THE UPPER
MIDWEST. A SURFACE LOW WAS LOCATED IN CENTRAL MINNESOTA...AND WILL
CONTINUE MOVING ESE TONIGHT. STRONG WINDS ON THE BACKSIDE WILL
CONTINUE THROUGH THE AFTERNOON AND DIMINISH THIS EVENING. THERE MAY
BE ADDITIONAL SHOWER DEVELOPMENT IN THE STRATOCU DECK THIS
AFTERNOON...WITH A CLAP OF THUNDER NOT OUT OF THE QUESTION. WESTERN
WISCONSIN IS THE BEST BET TO FIND RAIN THIS AFTERNOON AND EVENING.
THE CLEARING TREND IN WESTERN MINNESOTA WILL CONTINUE TOWARD THE
EAST AS THE ABOVE MENTIONED STRATOCU DECK SLIDES EAST WITH THE UPPER
TROUGH...AS TONIGHT SHOULD BE PARTLY CLOUDY ACROSS THE FA /LATER IN
WISCONSIN/. A STRONG UPPER LOW IN CANADA WILL ROTATE ANOTHER PV
ANOMALY TOWARD OUR AREA IN NORTHWEST FLOW TOMORROW...WHICH WILL
SPREAD MID LEVEL CLOUDS BACK IN TO MUCH OF MINNESOTA AND WISCONSIN.
KEPT A SLIGHT CHANCE OF PRECIPITATION IN THE FORECAST ALONG THE
NORTHERN PERIPHERY OF THE CWA...FROM NORTH OF ST. CLOUD...THROUGH
THE MILLE LACS LAKE AREA...AND TOWARD CHIPPEWA FALLS WISCONSIN. OUR
AREA IS SIMPLY SOUTH OF THE BEST LIFT...AND LOW LEVEL DRY AIR WILL
ONLY HAMPER THE CHANCES OF LIGHT RAIN REACHING THE SURFACE.
OTHERWISE...DEEP MIXING WILL OCCUR TOMORROW AND BREEZY CONDITIONS
WILL RESULT...AND TEMPERATURES REMAIN ON TRACK TO BE ABOUT 10
DEGREES BELOW NORMAL ACROSS THE BOARD.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 355 PM CDT FRI MAY 2 2014
A NORTH AMERICAN PROJECTION OF THE WATER VAPOR AND GFS 500MB
HEIGHTS IDENTIFIED NORTHWEST FLOW ACROSS THE MIDWEST...WITH TWO
LARGE UPPER LEVEL LOWS IN THE EASTERN PACIFIC. OVER THE NEXT COUPLE
OF DAYS THE EASTERN MOST UPPER LEVEL LOW WILL SEND A SERIES OF
SHORTWAVES ACROSS THE ROCKIES...WHICH WILL CAUSE THE FLOW TO BECOME
MORE ZONAL BY EARLY NEXT WEEK. ONE OF THESE SHORTWAVES WILL GENERATE
SHOWERS AND PERHAPS A THUNDERSTORM ON SUNDAY. AT THIS TIME IT LOOKS
LIKE THE BEST CHANCE FOR PRECIP WILL BE ALONG AND SOUTH OF THE
MINNESOTA RIVER VALLEY WHERE THE LOW LEVEL THERMAL GRADIENT WILL SET
UP AND CORRESPONDING H850-700MB FGEN. GIVEN THE STRONG
FORCING...HAVE INCLUDED ISOLATED THUNDER SINCE THERE IS SOME UPPER
LEVEL CAPE...BUT THE THREAT FOR SEVERE WEATHER IS VIRTUALLY NON
EXISTENT.
BY THE MIDDLE OF NEXT WEEK...A TROUGH WILL CARVE OUT ACROSS THE
DESERT SOUTHWEST WHICH WILL LEAD TO SOUTHWEST FLOW...GULF
MOISTURE...AND WARMER AIR OVER THE UPPER MIDWEST. CONFIDENCE IS HIGH
THAT PRECIP WILL OCCUR WITHIN THE WED/THU TIMEFRAME AS THE WARM
FRONT LIFTS NORTHWARD. THE CHALLENGE IS TRYING TO TIME THE PRECIP IN
THE 12HR GRIDS. AS OF NOW HAVE HIGHLIGHTED WEDNESDAY NIGHT TO
THURSDAY MORNING AS THE BEST CHANCE FOR RAIN WITH THE LOW LEVEL JET
AND THETA_E ADVECTION SPREADING OVERHEAD DURING THAT TIME PERIOD.
SEVERE WEATHER WILL BE POSSIBLE WITH FAVORABLE DEEP LAYER
SHEAR...AND ELEVATED INSTABILITY. THE POTENTIAL FOR SURFACE BASED
STORMS DEPENDS ON THE TIMING AND PLACEMENT OF THE SURFACE LOW. THE
GFS/ECMWF/GEM 02.12 ARE IN SOME DISAGREEMENT...WITH THE GFS
FARTHER WEST AND STRONGER THAN THE ECMWF...WHILE THE GEM IS
SIMILAR TO THE GFS IN LOCATION...ONLY LAGGING ABOUT 6HRS BEHIND. FOR
NOW WILL JUST GENERALIZE THE WEATHER TYPE WITH THUNDERSTORMS...BUT
IF THINGS COME TOGETHER THE POTENTIAL IS THERE FORE A FEW STRONG TO
SEVERE STORMS CENTERED AROUND THE THURSDAY TIMEFRAME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 100 PM CDT FRI MAY 2 2014
A FEW ISSUES TODAY...THE WIND SHIFT MOVING THROUGH THE FA NOW AND
THE WIND SPEEDS BEHIND IT...AND THE STRATO CU DEVELPOMENT ACROSS
SOUTHERN MINNESOTA. CU RULE VERY NEGATIVE TODAY...AND RAP SHOWING
SOLID 850 MOISTURE TO SUPPORT WIDESPREAD CLOUD COVER. THE ISSUE
THOUGH IS THE HEIGHT OF THESE CLOUDS...AS THEY LOOK TO STRADDLE
THE DIFFERNCE BETWEEN MVFR AND VFR CONDITIONS. COLD AIR ADVECTION
IS NOT IMPRESSIVE...SO MAY STAY VFR ALL AFTERNOON AT MANY
LOCATIONS. SOUTH WINDS ACROSS FAR EASTERN MINNESOTA AND IN
WISCONSIN WILL GRADUALLY SHIFT TOWARD THE NW THROUGH THE
AFTERNOON. DECENT GUSTS ARE EXPECTED TO DEVELOP IN THIS
AREA...AROUND 20-25KTS. STRONGER GUSTS WILL CONTINUE ACROSS
WESTERN MINNESOTA WHERE 30+ KTS HAS ALREADY BEEN OBSERVED.
SCATTERED SHOWERS AND A CLAP OF THUNDER IS POSSIBLE THIS
AFTERNOON/EARLY EVENING.
KMSP...ANY MVFR THIS AFTERNOON WILL BE BRIEF AS CEILING HEIGHTS
GRADUALLY LIFT. WINDS ARE IN THE PROCESS OF TURNING WESTERLY AND
INCREASING. KEPT -SHRA IN THE FORECAST TO ACCOUNT FOR THE
POSSIBILITY OF SCATTERED SHOWERS ACROSS THE AREA.
/OUTLOOK FOR KMSP/
SAT...VFR. NW WINDS 15G22 KTS.
SUN...VFR. NW WINDS 5 KTS BECOMING NE.
MON...VFR. SLIGHT CHANCE -SHRA. E WINDS 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...SPD
LONG TERM...JRB
AVIATION...SPD
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
145 PM CDT FRI MAY 2 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT FRI MAY 2 2014
DEEP LOW THAT HAS BEEN INFLUENCING OUR WEATHER SINCE SATURDAY IS
STARTING TO FINALLY LOSE ITS GRIP ON THE REGION AS A SFC RIDGE
AXIS HAS WORKED IN FROM THE WEST. THE GOOD NEWS IS THAT BEHIND
THIS RIDGE AXIS...SKIES HAVE CLEARED OUT WITH WITH DEVELOPMENT OF
SW WINDS. THE BAD NEWS...SAID CLEARING IS QUICKLY BEING GOBBLED UP
BY INCREASING MID/UPPER CLOUDS IN ASSOCIATION WITH A POTENT
NORTHWEST FLOW WAVE THAT WAS QUICKLY APPROACHING NW MN THIS
MORNING. IN FACT...THIS IS NOT THE ONLY WAVE THAT WILL POTENTIALLY
IMPACT THE AREA DURING THE SHORT TERM...AS ANOTHER...MORE POTENT
WAVE OVER NRN SASKATCHEWAN WILL HELP SEND A SECONDARY COLD FRONT
ANS SHOWER CHANCE TOWARD CENTRAL MN LATE TONIGHT.
THE WAVE NEAR WINNIPEG HAS A GOOD REFLECTION ON WV/IR SATELLITE
IMAGERY...BUT IS BATTLING DRY AIR AND SUBSIDENCE IN THE WAKE OF
THE SYSTEM THAT WAS SLOWLY WORKING INTO NW QUEBEC. THIS HAS
MEANT NOT MUCH IN THE WAY OF PRECIP HAS BEEN REACHING THE GROUND
THIS MORNING...BUT THAT IS EXPECTED TO CHANGE BY THE AFTERNOON.
THE ADDITION OF DIURNAL HEATING WITH THE COOL TEMPERATURES ALOFT
WILL ALLOW FOR THE DEVELOPMENT OF SOME RATHER HEALTHY SHOWERS BY
THE AFTERNOON...AS SEEN WITH THE MPXWRF AND HOPWRF MEMBERS. ALSO
ADDED IN AN ISO THUNDER MENTION FOR THE AFTERNOON AS HIGH-RES
MODELS ARE SHOWING RATHER AGITATED RETURNS DEVELOPING IN THEIR
REFLECTIVITY FORECASTS...WITH NAM BUFR SOUNDINGS SHOWING A COUPLE
HUNDRED J/KG OF MUCAPE DEVELOPING AS WELL. NOT EXPECTING A LOT OF
THUNDER...BUT ENOUGH INSTABILITY LOOKS TO EXIST TO GENERATE A FEW
CLAPS OF THUNDER. THIS ACTIVITY IS EXPECTED TO REMAIN MAINLY EAST
OF THE MISSISSIPPI RIVER...AS THE MID LEVEL DRY SLOT LOOKS TO KEEP
AREAS WEST OF THE MISS DRY.
BESIDE THE PRECIP...WAA OUT AHEAD OF THIS FIRST WAVE WILL SEND H85
TEMPS UP TO AROUND +4 IN SW MN. THIS COMBINED WITH MORE ABUNDANT
SUNSHINE WILL BE ENOUGH TO ALLOW AREAS ALONG AND SW OF A MORRIS TO
ALBERT LEA LINE TO REACH THE 60 DEGREE MARK. HOWEVER...THESE
WARMER TEMPERATURES WILL BE OFFSET SOME BY THE DEVELOPMENT OF
BREEZY NW WINDS BY THE AFTERNOON IN THE WAKE OF THE COLD FRONT...
WITH GUSTS AOA 30 MPH LIKELY OUT IN THE WIND FAVORED AREAS OF
WRN/SRN MN.
THIS EVENING...WILL LIKELY SEE SKIES CLEAR OUT FOR A BIT BEHIND
THIS FIRST WAVE...BUT THE ARRIVAL OF THE NEXT WAVE BY THE END OF
THE PERIOD WILL RESULT IN THE QUICK RETURN OF CLOUD COVER. THIS
SECOND WAVE LOOKS TO HAVE EVEN LESS MOISTURE TO WORK WITH THAN THE
ONE FOR TODAY...SO EXPECTING EVEN LESS PRECIP WITH IT. STILL...HI-
RES CAMS ALONG WITH MOST DETERMINISTIC MODELS DO SHOW THE NEXT
POTENTIAL BOUT OF SHOWERS WORKING INTO CENTRAL MN BY 12Z SAT...SO
HAVE A LITTLE CHANCE OF 20 POPS TO ACCOUNT FOR THAT WITH BETTER
PRECIP COVERAGE EXPECTED TO THE NORTH.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 420 AM CDT FRI MAY 2 2014
SATURDAY THROUGH MONDAY...THE FIRST PART OF THE EXTENDED FORECAST
LOOKS RATHER BENIGN AS NW FLOW ALOFT TRANSITIONS TO A BUILDING UPR
LVL RIDGE WHILE SFC HIGH PRES IS THE DOMINANT SFC FEATURE. AN UPR
LVL RIDGE THAT WAS QUASI-STNRY OVER THE WRN CONUS WILL GRADUALLY
SHIFT INTO THE CENTRAL CONUS OVER THE WEEKEND...KEEPING THE WARMER
HIGHS OF 50S TO LWR 60S IN PLACE INTO EARLY NEXT WEEK. THE WARMING
TREND OVER THE WEEKEND IS NOT AS IMPRESSIVE AS WHAT PRIOR MODEL
RUNS HAD SHOWN...DUE TO THE RIDGE BREAKING DOWN SOMEWHAT AS IT
MOVES INTO THE CENTRAL STATES. THIS BREAKDOWN IN THE RIDGE WILL
ALSO IMPACT THE POTENTIAL FOR PRECIP...OR MORE TO THE POINT... THE
POTENTIAL FOR SOLID DRY TIME THROUGHOUT THE WEEKEND INTO EARLY
NEXT WEEK. SFC HIGH PRES NUDGING INTO THIS REGION FROM WRN CANADA
WILL SLOWLY RETREAT NWD...LEAVING A TRANSITION ZONE IN PLACE
BETWEEN LOW PRES TO THE SW AND HIGH PRES TO THE N. SEVERAL WEAK
UPR LVL DISTURBANCES RIDING THE PERIPHERY OF THE UPR LVL RIDGE
WITHIN FAIRLY DEEP MOISTURE MAY BE ENOUGH TO PRODUCE ISOLD TO SCTD
SHWRS FROM TIME TO TIME OVER THE AREA...WITH THE MOST PRONOUNCED
OF WHICH DRIVING SWWD FROM SAT NIGHT INTO SUN MRNG OVER SWRN AND
SRN MN. HAVE KEPT POPS FOR THIS FEATURE IN THE CHC CATEGORY DUE TO
THE SPEED OF THE PV ANOMALY ASSOCIATED WITH THIS WAVE AND HIGHLY
VARIABLE SOLUTIONS WITH RESPECT TO COVERAGE. HIGH PRES LOOKS TO
BETTER RE-ASSERT ITSELF MON NIGHT OVER THE GRT LKS...XTNDG WWD
INTO MN...THUS HAVE BEEN ABLE TO SHOW A DRY FCST FOR MON NIGHT.
TUESDAY THROUGH THURSDAY...A MORE ACTIVE PATTERN LOOKS TO BE THE
CASE DURG THE MIDDLE PORTION OF NEXT WEEK AS A LONGWAVE TROF
DRIVING SWD FROM THE GULF OF ALASKA DOWN THE WRN NOAM COAST MOVES
ONSHORE THE CALI COAST SAT-TUE. AS IT MOVES OVER THE SWRN STATES
TUE AND TUE NIGHT...IT WILL PICK UP A DEVELOPING LOW PRES CENTER
OVER THE FAVORED CO/KS CYCLOGENESIS REGION AND SLOWLY SHIFT IT ENE
TUE NIGHT THRU THU. WHAT IS DIFFICULT TO DETERMINE ATTM IS THE
TRACK AND SPEED OF ITS PROGRESSION. THERE ARE SIGNIFICANT MODEL
DISCREPANCIES IN THESE ASPECTS...WHICH WOULD GREATLY IMPACT THE
TSTM...AND POSSIBLE SEVERE WX...DISTRIBUTION FOR THE CENTRAL
STATES BY MIDWEEK. ATTM...MORE CONFIDENCE IS BEING SHOWN IN
KEEPING THE LOW PRES TRACK S OF MN/WI...OVER MORE OF A KS-NE-IA-IL
TRACK. THIS WOULD KEEP GREATER ISENTROPIC LIFT AND MORE WIDESPREAD
MOISTURE OVER THE AREA WITH COOLER TEMPERATURES...WHILE GREATER
INSTABILITY WITH WARMER TEMPERATURES AND STRONGER DYNAMIC FEATURES
WOULD BE S OF THIS REGION. THUS...TSTMS CANNOT BE RULED OUT...BUT
THE SRN TRACK DOES GIVE RISE TO ADDITIONAL HIGH RAINFALL AMOUNTS.
SO...HAVE BEEN ABLE TO RAISE POPS TO 50-60 PERCENT FOR MUCH OF THE
AREA WED INTO THU SINCE CONFIDENCE IS GREATER THAT THERE WILL BE
SHWRS/TSTMS BUT IT BECOMES A MATTER OF DETERMINING THE STORM
STRENGTH WHICH WILL COME AS MODEL AGREEMENT INCREASES WITH THE LOW
PRES TRACK. HAVE ALSO SLIGHTLY NUDGED UP TEMPS IN THE TUE-THU
PERIOD...ESP OVER SRN MN WHICH WILL LIKELY EXPERIENCE HIGHS
HITTING THE LWR 70S WED-THU.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 100 PM CDT FRI MAY 2 2014
A FEW ISSUES TODAY...THE WIND SHIFT MOVING THROUGH THE FA NOW AND
THE WIND SPEEDS BEHIND IT...AND THE STRATO CU DEVELPOMENT ACROSS
SOUTHERN MINNESOTA. CU RULE VERY NEGATIVE TODAY...AND RAP SHOWING
SOLID 850 MOISTURE TO SUPPORT WIDESPREAD CLOUD COVER. THE ISSUE
THOUGH IS THE HEIGHT OF THESE CLOUDS...AS THEY LOOK TO STRADDLE
THE DIFFERNCE BETWEEN MVFR AND VFR CONDITIONS. COLD AIR ADVECTION
IS NOT IMPRESSIVE...SO MAY STAY VFR ALL AFTERNOON AT MANY
LOCATIONS. SOUTH WINDS ACROSS FAR EASTERN MINNESOTA AND IN
WISCONSIN WILL GRADUALLY SHIFT TOWARD THE NW THROUGH THE
AFTERNOON. DECENT GUSTS ARE EXPECTED TO DEVELOP IN THIS
AREA...AROUND 20-25KTS. STRONGER GUSTS WILL CONTINUE ACROSS
WESTERN MINNESOTA WHERE 30+ KTS HAS ALREADY BEEN OBSERVED.
SCATTERED SHOWERS AND A CLAP OF THUNDER IS POSSIBLE THIS
AFTERNOON/EARLY EVENING.
KMSP...ANY MVFR THIS AFTERNOON WILL BE BRIEF AS CEILING HEIGHTS
GRADUALLY LIFT. WINDS ARE IN THE PROCESS OF TURNING WESTERLY AND
INCREASING. KEPT -SHRA IN THE FORECAST TO ACCOUNT FOR THE
POSSIBILITY OF SCATTERED SHOWERS ACROSS THE AREA.
/OUTLOOK FOR KMSP/
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JPC
AVIATION...SPD
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1240 PM CDT FRI MAY 2 2014
.SYNOPSIS...
ISSUED AT 341 AM CDT FRI MAY 2 2014
AT 08Z...A COLD FRONT WAS MOVING SOUTHEAST THROUGH NORTHWESTERN
NORTH DAKOTA. ACROSS WESTERN NEBRASKA WINDS WERE LIGHT WESTERLY AT
5 MPH OR LESS. BENEATH MOSTLY CLEAR SKIES...TEMPERATURES WERE IN
THE LOWER TO MID 30S...WITH THE COLDEST READING OF 27 AT LBF.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 341 AM CDT FRI MAY 2 2014
A HIGHLY AMPLIFIED H5 PATTERN EXISTS WITH A STRONG RIDGE ALONG
THE WESTERN STATES WHILE A POSITIVELY TILTED TROUGH EXTENDED FROM
WEST TEXAS INTO THE GREAT LAKES REGION. FOR TODAY...INCREASING
CLOUDINESS WITH A WEAK COLD FRONT DROPPING SOUTH INTO THE
NORTHERN PANHANDLE AND CENTRAL NEBRASKA BY LATE AFTERNOON. NOT
TOO MUCH CONTRAST IN HIGHS HOWEVER RANGING FROM THE UPPER 60S AT
VTN...ANW AND ONL TO 76 AT IML. NW WINDS TO RANGE FROM 10 TO 20
MPH TODAY...WHICH WILL BE LIGHTER THAN THE PAST SEVERAL DAYS.
REGARDING CHANCES FOR ANY SHOWERS OR THUNDERSTORMS...HAVE TRIMMED
WEST THE AREA TO MAINLY THE EASTERN PANHANDLE AND WESTERN CHERRY
COUNTY THIS AFTERNOON. THE NAM AND RAP MODELS ARE SIMILAR
TARGETING THESE AREAS. A DISTURBANCE TO MOVE THROUGH EASTERN
WYOMING AND THE BLACK HILLS REGION EARLY THIS AFTERNOON AND
SHOULD TRIGGER ISOLATED SHOWERS OR THUNDERSTORMS. THE STEEPER H7
TO H5 LAPSE RATES NEAR 7.5 C.KM WILL BE PERCENT IN THE PANHANDLE
AND SW NEBR THIS AFTERNOON. A DISTURBANCE BEHIND THE COLD FRONT
WILL TRIGGER SOME SHOWERS FROM EASTERN MONTANA INTO WESTERN AND
CENTRAL SOUTH DAKOTA TODAY. WHILE A FEW OF THESE SHOWERS COULD
MOVE INTO NORTH CENTRAL NEBRASKA THIS AFTERNOON...MODELS DO NOT
SUPPORT SUFFICIENT LIFT TO INTRODUCE A MENTION.
TONIGHT...CONTINUED A SLIGHT CHANCE FOR SHOWERS IN THE EASTERN
PANHANDLE AND WESTERN CHERRY COUNTY...WHICH SHOULD DISSIPATE BY
AROUND SUNSET. WITH A MILDER AIR MASS IN PLACE AND WEAK LOW
PRESSURE...TEMPERATURES WILL RANGE FROM THE UPPER 30S FAR
NORTHWEST TO THE LOWER 40S ELSEWHERE. SKIES WILL BE CLEARING IN
THE WEST WITH LINGERING CLOUDINESS ACROSS THE EAST.
SYNOPTICALLY...THE UPPER RIDGE IN THE WEST WILL FLATTEN OUT AS IT
MOVES INTO THE GREAT BASIN WHILE A CLOSED LOW MOVES INTO MANITOBA
AND WESTERN ONTARIO. THIS WILL KEEP THE COOLER AIR TO OUR NORTH
ACROSS THE DAKOTAS AND GREAT LAKES.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 341 AM CDT FRI MAY 2 2014
SATURDAY WILL SEE THE LOW PUSHING ACROSS THE NE PACIFIC...HEADING
FOR THE PACIFIC NW STATES. THIS WILL CAUSE THE HIGH ACROSS THE
DESERT SOUTHWEST TO PUSH EAST. MEANWHILE A LEE SIDE TROUGH WILL
DEVELOP. AS THE RIDGE SLIDING EAST...HEIGHTS INCREASE ACROSS THE
AREA. NAM HAS BEEN THE FASTEST WITH THE HEIGHT INCREASES...WHICH
HAS TRANSLATED TO MET GUIDANCE IN SW NEB INTO THE 80S. THE
SLIGHTLY SLOWER GFS/EC MOS GUIDANCE HAS HELD MOST SITES ACROSS SW
IN THE 70S. THE SW PART OF NEB DID SEE A QUARTER TO HALF AN INCH
WITH THIS LATE APRIL EVENT...HOWEVER THE MONTH ENDED 1 TO 2 INCHES
BELOW NORMAL. EXPECT THE RELATIVELY DRY SOILS TO AID IN WARMING
CLOSER TO THE MET GUIDANCE NUMBERS. ALTHOUGH LATELY THE WARMEST
GUIDANCE HAS BEEN THE WAY TO GO DURING THESE ABOVE NORMAL
DAYS...SO MAY NEED TO TREND THIS WARMER YET. MEANWHILE A SFC HIGH
WILL DIVE SOUTH INTO THE NORTHERN PLAINS. WHILE THE HIGH IS
CENTERED WELL NORTH OF THE AREA...COOLER AIR IN ASSOCIATION WITH
THE HIGH WILL PUSH INTO THE DAKOTAS AND PARTS OF NRN NEB. HIGHS ON
SAT ACROSS THE NORTH SHOULD WARM TO AROUND 70.
SATURDAY AFTERNOON STEEP LAPSE RATE DEVELOP ALONG THE LEE SIDE
TROUGH. WOULD EXPECT SOME SHOWERS TO DEVELOP DURING THE PEAK
HEAT...ALTHOUGH MOISTURE...DEW PTS IN THE 40S...MAY BE TOO DRY
FOR ANYTHING TO REACH THE GROUND. A BETTER CHANCE...ALBEIT ONLY
SLIGHTLY BETTER...WILL BE WITH A QUASI-STATIONARY BOUNDARY
BETWEEN THE COOLER NORTHERN HIGH AND WARMER SW SAT EVENING. AGAIN
MOISTURE IS A CONCERN AND RETAINED LOW POPS...ALTHOUGH NOT
LOOKING AS GOOD AS YESTERDAY AND SCALED BACK THE COVERAGE.
SUNDAY THE RIDGE CONTINUES TO ADVANCE EAST...BUT BECOMES MORE
BROAD. HIGHS AGAIN INTO THE 80S ACROSS SW WITH MORE CLOUDS ACROSS
THE NORTH...NEAR THE BOUNDARY...AND HIGHS IN THE 60S. SUNDAY
EVENING THE BOUNDARY LIFTS NORTH AND FORECAST AREA LOOKS DRY WITH
THE ACTIVITY NORTH OF THE BORDER.
BY MONDAY THE BROAD RIDGE AXIS WILL BE EAST WITH SW NEB DROPPING
TO AROUND 80. MORE SUN ACROSS THE NORTH AND HIGHS SHOULD BE ABLE
TO WARM ABOVE SUNDAY READINGS...CLOSER TO 70.
TUESDAY THROUGH THE THURSDAY A MORE ACTIVE PATTER IS SETTING UP.
THE NORTHEAST PACIFIC LOW WILL OPEN INTO A TROUGH AS IT DIGS INTO
THE 4 CORNERS REGION. THE GFS CONTINUES TO THEN EJECT THE LOW
ONTO THE CENTRAL PLAINS. THE ECMWF BREAKS UP THE LOW WITH A PIECE
PUSHING ONTO THE PLAINS WITH A SECONDARY LOW DEVELOPING OFF THE
COAST OF BAJA. EITHER WAY BOTH MODELS SUPPORT A CHANCE FOR
PRECIPITATION ACROSS THE AREA. THE GULF DOES OPEN UP...HOWEVER
THIS IS SHORT LIVED WITH A COLD FRONT TO PUSH ACROSS THE AREA AND
KEEP THE BULK OF THE MOISTURE SOUTH AND EAST OF THE AREA. TEMPS
COOL INTO THE 60S AND 70S...AND WILL CONTINUE TO MONITOR THE
MOISTURE PUSH NORTHWARD WHICH WILL EFFECT THE QPF AMOUNTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1236 PM CDT FRI MAY 2 2014
VFR CONDITIONS EXPECTED ACROSS WESTERN AND NORTH CENTRAL NEBRASKA
THROUGH THE NEXT 24 HOURS. ISOLATED SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE IN THE EASTERN PANHANDLE TOWARD LATE AFTERNOON
AND EARLY EVENING...HOWEVER THE ACTIVITY SHOULD BE WIDELY
SCATTERED WITH CIGS AOA 5 KFT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...MASEK
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
300 PM EDT FRI MAY 2 2014
.SYNOPSIS...
AN IMPULSE ALOFT APPROACHING FROM THE SOUTHWEST PASS THROUGH THE
AREA TONIGHT AND EARLY SATURDAY. SEASONABLE HIGH PRESSURE WILL
BUILD IN THROUGH THE WEEKEND. A COLD FRONT WILL PRESS SOUTHWARD AND
STALL OVER EASTERN NORTH CAROLINA EARLY NEXT WEEK. WARM HIGH
PRESSURE WILL BUILD INTO THE REGION THROUGH THE END OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...MOSAIC RADAR BEAMS ARE CATCHING WIDESPREAD
ECHOS ACROSS THE FORECAST AREA...BUT OBSERVED HOURLY RAINFALL
AMOUNTS PAINT A DRIER PICTURE THAN IS PRESENTED GRAPHICALLY BY
THE SUITE OF LOCAL 88 DELTAS. OF INTEREST IS SHORT-WAVE ENERGY
MOVING FROM THE NE GULF INTO GEORGIA THIS AFTERNOON. THIS FEATURE
MAY AID IN STIRRING UPWARD VERTICAL MOTIONS...THROUGH MIDDLE INTO
LATE AFTERNOON. THE MOST SIGNIFICANT RAIN AREA OFFSHORE OF N FL
AND SC APPEARS ON A TRACK THAT WILL REMAIN OFFSHORE OF OUR COUNTY
WARNING AREA.
COMPOSITE/CONSENSUS PCPN FIELDS PULL ALL RAIN OFFSHORE BY 11PM
EXCEPT FOR THE RAP-13...WHICH IS BIT UNSETTLING SINCE BY THEORY
A RAPID UPDATE NEAR-TERM MODEL INGESTS THE LATEST AND GREATEST.
THE RAP GENERATES A FEW SHOWERS IN THE PRE-DAWN HOURS ALONG THE
COAST...APPARENTLY KEYING ON THE POTENT APPEARING VORT CAREENING
INTO WESTERN TN AND WESTERN MS. THIS FEATURE IN FACT DOES IMPART
A SURFACE REFLECTION IN THE FORM OF A MINOR AND SECONDARY COLD
FRONT. WITH THIS IN MIND WILL KEEP ISOLATED SHOWERS AT THE COAST
INTO THE DAYBREAK HOURS. MINIMUMS INTO THE 50S EXPECTED AREA-WIDE
BUT COOLEST INLAND...AS A SECONDARY SURGE OF COOL AIR FILTERS INTO
THE REGION AFTER 8-9 ZULU/4-5 AM.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...A COLD FRONT JUST OFF THE COAST SAT AM WILL MOVE
OUT TO SEA OVER THE WEEKEND AS HIGH PRESSURE RIDGES INTO THE AREA.
ANOTHER COLD FRONT WILL APPROACH FROM THE NORTH SUNDAY NIGHT AND
MOVE INTO THE AREA LATE. AFTER SOME MORNING CLOUDS AND POSSIBLY A
FEW LIGHT SHOWERS EARLY SATURDAY...EXPECT FAIR WEATHER THROUGH THE
WEEKEND. MAX TEMPERATURES AWAY FROM THE BEACHES WILL BE IN THE MID
TO UPPER 70S SATURDAY AND LOW TO MID 80S SUNDAY. MINS SATURDAY
NIGHT WILL BE IN THE LOW TO MID 50S WITH UPPER 50S TO AROUND 60
EXPECTED SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...OVERALL THE LONG TERM LOOKS PRETTY QUIET. THERE
IS SOME UNCERTAINTY AS TO HOW FAR SOUTH A BACKDOOR COLD FRONT
PROGRESSES EARLY IN THE PERIOD. MODEL GUIDANCE HAS SHIFTED A BIT TO
THE SOUTH AND THE BOUNDARY MAY ENTER NORTHERN ZONES. SOME VERY LOW
POPS HAVE BEEN ADDED AS A RESULT. AS THE PARENT HIGH SHIFTS EASTWARD
OFF THE MID ATLANTIC COAST THIS BOUNDARY WILL MOVE BACK TO THE NORTH
IN A WEAKENING STATE AROUND WEDNESDAY. THE LATTER PART OF THE WEEK
WILL BRING RISING HEIGHTS AS UPPER RIDGE BUILDS AND HIGHEST SFC
PRESSURES OFF THE COAST.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...CURRENT RADAR IMAGERY SHOWS PATCHES OF LIGHT RAIN MOVING
OVER THE EASTERN CAROLINAS ASSOCIATED WITH AN UPPER DISTURBANCE.
WILL INCLUDE VCSH FOR ALL TAF SITES THIS AFTERNOON...THOUGH VFR
CONDITIONS WILL LIKELY PREVAIL EVEN IN AREAS OF PRECIP. LIGHT
NORTHERLY WINDS FROM THIS MORNING WILL BECOME VRB AROUND 5 KTS AFTER
18Z AS A VERY WEAK GRADIENT EXISTS WITH THE FRONT STALLED OFFSHORE.
MID LEVEL CIGS WILL PERSIST INTO TONIGHT AS UPPER TROUGH AXIS
REMAINS TO OUR WEST. DESPITE THE LIGHT WINDS OVERNIGHT...CLOUD COVER
SHOULD INHIBIT FOG DEVELOPMENT. CANNOT RULE OUT TEMPO MVFR CIGS AT
KILM/KCRE/KMYR AFTER 06Z...BUT SREF OUTPUT INDICATES THE SUB-VFR
CIGS WILL REMAIN OFF THE COAST. EXPECT DECREASING CLOUD COVER BY
MIDDAY SATURDAY AS THE UPPER TROUGH FINALLY PUSHES EAST AND USHERS
IN SOME DRIER AIR.
EXTENDED OUTLOOK...SLIGHT CHANCE OF SHOWERS LATE MONDAY INTO EARLY
TUESDAY ASSOCIATED WITH A STALLED FRONT TO OUR NORTH. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...NO ADVISORIES OR EXERCISE CAUTION HEADLINES
WILL BE NEEDED OVERNIGHT. WINDS WILL BE CHANGEABLE BUT NOT STRONG
AS A SECONDARY BUT WEAK COLD FRONT PASSES ACROSS THE COAST INTO
EARLY SATURDAY JUST PRIOR TO OR AROUND DAYBREAK. SEAS MAINLY 2-3
FEET IN A MIX OF 2-3 FT SSE WAVES EVERY 6-8 SECONDS AND A LIGHT
CHOP. LIGHT S-SW WINDS TONIGHT WILL PREVAIL...FOLLOWED BY A WIND-
SHIFT TO THE NW INTO FIRST LIGHT OF SATURDAY AS THE FRONT MOVES
THROUGH. NO TSTMS EXPECTED OVER THE INSHORE WATERS...BUT A FEW
STORMS MAY LIGHT UP THE GULF STREAM INTO EARLY SATURDAY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...LIGHT WEST TO SOUTHWEST FLOW AROUND 10 KT IS
EXPECTED SATURDAY AND SATURDAY NIGHT BEFORE BECOMING SOLIDLY SW
SUNDAY AND INCREASING TO 15 KT BY AFTERNOON AND CONTINUING INTO
SUNDAY NIGHT. WINDS WILL BECOME MORE WESTERLY NORTHERN WATERS LATE
AS A FRONT APPROACHES FROM THE NORTH. SEAS OF 2 TO 3 FT EARLY
SATURDAY WILL SUBSIDE TO 2 FT OR LESS BY SATURDAY EVENING AND
CONTINUE INTO SUNDAY BEFORE BUILDING TO 2 TO 3 FT BY SUNDAY NIGHT.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...WITH A BACKDOOR COLD FRONT STALLED CLOSE TO IF
NOT ACROSS THE REGION FOR MOST OF THE PERIOD WINDS AND SEAS WILL
BOTH BE RATHER MINIMAL. THERE IS SOME UNCERTAINTY REGARDING HOW FAR
SOUTH THE BOUNDARY WILL SAG HOWEVER AND THIS TRANSLATES TO SOME
POSSIBLE ERROR IN WIND FCST OVER MAINLY NRN ZONES. SRN ZONES SHOULD
REMAIN ON THE SOUTH SIDE OF THE BOUNDARY AND THUS KEEP A
PREDOMINANTLY SOUTHWESTERN FLOW.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...31
LONG TERM...MBB
AVIATION...BJR/8
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
403 PM MDT FRI MAY 2 2014
.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 216 PM MDT FRI MAY 2 2014
20Z SURFACE ANALYSIS SHOWED COOL FRONT HAD STALLED FROM CENTRAL
MT INTO WESTERN NE INTO NORTHWEST IA. WEAK HIGH PRESSURE BUILDING
BEHIND IT. SHORTWAVE ENERGY OVER NORTHEAST MT/ND SUPPORTING BAND
OF POST FRONTAL -SHRA FROM EASTERN MT INTO CENTRAL SD...BUT HAVING
A BIT OF TROUBLE MAINTAINING THEMSELVES GIVEN DRIER AIR OVER THE
CWA. ACTIVITY MAY YET EXPAND PER LOCAL WRF/18Z RAP LATE THIS
AFTERNOON/EARLY THIS EVENING AS WEAK MLCAPE DEVELOPS AND SHORTWAVE
ENERGY RUSHES PAST. LOWS TONIGHT WILL BE NEAR GUIDANCE.
SATURDAY...FRONTAL BOUNDARY WILL MOVE LITTLE AS LOW LEVEL BAROCLINIC
ZONE REMAINS STRETCHED FROM NORTHWEST TO SOUTHEAST ACROSS THE CWA.
COUPLE OF SHORTWAVES WILL MOVE NORTH OF CWA BRINGING JUST ENOUGH
FORCING FOR A FEW -SHRA/DIURNALLY DRIVEN -TSRA GIVEN WEAK MLCAPE.
ACTIVITY WILL HAVE BEST CHANCE OVER THE FAR NORTH SATURDAY NIGHT AS
LOW LEVEL FLOW BECOMES UPSLOPE AND BEST WAVE MOVES ACROSS ND.
TEMPERATURES WILL BE TRICKY GIVEN CLOUD COVER/TIGHT ISOTHERMS...SO
TRENDED COOLISH IN THE NORTH AND WARMISH IN THE SOUTH/WEST.
&&
.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 216 PM MDT FRI MAY 2 2014
WEST TO SWRLY FLOW OVER THE REGION WILL START THE WEEK WITH A
VARIETY OF WEAK DISTURBANCES MOVING THROUGH...BRINGING PRECIP
CHANCES TO THE AREA. FOR THE MID-WEEK...A SPLIT FLOW TROF IS
PROGGED TO CROSS THE ROCKIES WITH STRONGER SWRLY FLOW
DEVELOPING...BRINGING GREATER SHOWER/THUNDERSTORM CHANCES. DRIER
WEATHER MAY RETURN LATER IN THE WORK WEEK...BUT WILL LEAVE SLIGHT
CHANCE POPS FOR NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 401 PM MDT FRI MAY 2 2014
SCT -SHRA WITH ISOLD -TSRA ARE EXPECTED THROUGH THIS EVENING.
ISOLD -SHRA WILL BE POSSIBLE LATE TONIGHT THROUGH THE DAY TOMORROW
ACROSS PORTIONS OF NE WY TO NW SD AND THE BLKHLS AREA. ISOLD -TSRA
ARE POSSIBLE IN THE AFTERNOON. LCL MVFR CONDITIONS WILL BE
POSSIBLE IN AND NEAR ANY PRECIP. THERE IS ALSO A CHANCE OF MVFR
STRATUS DEVELOPING ACROSS PORTIONS OF NERN WY AND NWRN SD LATE
TONIGHT AND SATURDAY MORNING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...HELGESON
LONG TERM...13
AVIATION...JOHNSON
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
217 PM MDT FRI MAY 2 2014
.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 216 PM MDT FRI MAY 2 2014
20Z SURFACE ANALYSIS SHOWED COOL FRONT HAD STALLED FROM CENTRAL
MT INTO WESTERN NE INTO NORTHWEST IA. WEAK HIGH PRESSURE BUILDING
BEHIND IT. SHORTWAVE ENERGY OVER NORTHEAST MT/ND SUPPORTING BAND
OF POST FRONTAL -SHRA FROM EASTERN MT INTO CENTRAL SD...BUT HAVING
A BIT OF TROUBLE MAINTAINING THEMSELVES GIVEN DRIER AIR OVER THE
CWA. ACTIVITY MAY YET EXPAND PER LOCAL WRF/18Z RAP LATE THIS
AFTERNOON/EARLY THIS EVENING AS WEAK MLCAPE DEVELOPS AND SHORTWAVE
ENERGY RUSHES PAST. LOWS TONIGHT WILL BE NEAR GUIDANCE.
SATURDAY...FRONTAL BOUNDARY WILL MOVE LITTLE AS LOW LEVEL BAROCLINIC
ZONE REMAINS STRETCHED FROM NORTHWEST TO SOUTHEAST ACROSS THE CWA.
COUPLE OF SHORTWAVES WILL MOVE NORTH OF CWA BRINGING JUST ENOUGH
FORCING FOR A FEW -SHRA/DIURNALLY DRIVEN -TSRA GIVEN WEAK MLCAPE.
ACTIVITY WILL HAVE BEST CHANCE OVER THE FAR NORTH SATURDAY NIGHT AS
LOW LEVEL FLOW BECOMES UPSLOPE AND BEST WAVE MOVES ACROSS ND.
TEMPERATURES WILL BE TRICKY GIVEN CLOUD COVER/TIGHT ISOTHERMS...SO
TRENDED COOLISH IN THE NORTH AND WARMISH IN THE SOUTH/WEST.
&&
.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 216 PM MDT FRI MAY 2 2014
WEST TO SWRLY FLOW OVER THE REGION WILL START THE WEEK WITH A
VARIETY OF WEAK DISTURBANCES MOVING THROUGH...BRINGING PRECIP
CHANCES TO THE AREA. FOR THE MID-WEEK...A SPLIT FLOW TROF IS
PROGGED TO CROSS THE ROCKIES WITH STRONGER SWRLY FLOW
DEVELOPING...BRINGING GREATER SHOWER/THUNDERSTORM CHANCES. DRIER
WEATHER MAY RETURN LATER IN THE WORK WEEK...BUT WILL LEAVE SLIGHT
CHANCE POPS FOR NOW.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SATURDAY
ISSUED AT 216 PM MDT FRI MAY 2 2014
SCT -SHRA WITH ISOLD -TSRA ARE EXPECTED THROUGH THIS EVENING.
ISOLD -SHRA WILL BE POSSIBLE LATE TONIGHT THROUGH THE DAY TOMORROW
ACROSS PORTIONS OF NE WY TO NW SD AND THE BLKHLS AREA. ISOLD -TSRA
ARE POSSIBLE IN THE AFTERNOON. LCL MVFR VIS/CIGS WILL BE POSSIBLE
IN AND NEAR ANY PRECIP.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...HELGESON
LONG TERM...13
AVIATION...13
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1128 AM MDT FRI MAY 2 2014
.UPDATE...
ISSUED AT 903 AM MDT FRI MAY 2 2014
15Z SURFACE ANALYSIS HAD COOL FRONT FROM KBWP TO KCUT TO
KBIL...SLOWLY SINKING SOUTH. SHORTWAVE ENERGY NOTED ON WATER
VAPOUR ACROSS SOUTHERN AB/SK...SLINKING SOUTHEAST ON 90KT UPPER
LEVEL JET. REGIONAL RADAR LOOP HAD POST FRONTAL SHRA ASSOCIATED
WITH SHORTWAVE ENERGY AND STEEP LAPSE RATES PER 12Z KUNR SOUNDING
AND SATURATED MID-LEVEL 12Z KGGW SOUNDING. 12Z RAP SHOWED CURRENT
ACTIVITY WELL...AND IT SPREADS SHRA ACROSS THE MAJORITY OF THE CWA
THROUGH THIS AFTERNOON/EARLY THIS EVENING AND HAVE ADJUSTED
SCATTERED POPS TO MATCH. WHERE BETTER DIURNAL HEATING
OCCURS...NORTHEAST WY/SOUTHWEST SD...HAVE KEPT TS MENTION GIVEN
250J/KG MUCAPE AVAILABLE DURING PEAK HEATING. HAVE ALSO ADJUSTED
TEMPERATURES FOR HIGHER CLOUD COVER.
&&
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 303 AM MDT FRI MAY 2 2014
LEAD UPPER LEVEL IMPULSE IN NW FLOW...ADVECTING SE
ACROSS THE NORTHERN HIGH PLAINS...WITH AN ASSOCIATED SFC TROUGH NOW
ENTERING NW SD /08Z/. THIS SFC TROUGH WILL SAG SOUTH ACROSS THE FA
TODAY...WITH IMPULSE LADED NW FLOW SUPPORTING CHANCES FOR SHRA
ACROSS THE REGION. LL FRONTAL ZONE WILL WAVER N-S ACROSS THE REGION
AS A SERIES OF IMPULSES ADVECT QUICKLY SE THROUGH THE FLOW. DEGREE
OF CAA UNDER THE SOUTHERN CANADIAN HEIGHT ANOMALY LOOKS TO BE MUCH
STRONGER THAN PREVIOUS MODEL RUNS HAVE INDICATED...SUPPORTING A
SOUTH BIAS TO THE SFC COLD FRONT IN THE PERIOD. THIS WOULD TEND TO
SUPPORT SLIGHTLY COOLER CONDITIONS ACROSS THE NW HALF...ESP SAT.
TODAY/TONIGHT...SFC TROUGH WILL SAG SOUTH INTO THE FA...BEHIND THE
LEAD IMPULSE. SECONDARY IMPULSE ON THE HEALS OF HE FIRST WILL
SUPPORT A WEAK HIGH CENTERED FGEN RESPONSE WITH SHRA ACTIVITY
SPREADING SOUTH INTO NW SD. FORECAST MODELS HAVE BEEN HIGHLY
CHANGEABLE PER QPF AMOUNTS ACROSS THE NW...BACKING OFF SIG WITH THE
LATEST RUNS TO MORE REASONABLE VALUES GIVEN LIFT PROFILES. COOLER
TEMPS EXPECTED THERE GIVEN CLOUDS/PRECIP AND WEAK CAA. FURTHER
SOUTH...DIURNAL HEATING WITH THE PASSING WEAK IMPULSE SHOULD BE
ENOUGH FOR A FEW ISOLD SHRA/TS BY AFTERNOON. KEPT POPS GENERALLY
LOW /SAVE THE FAR NW/ AS THE MAIN LOBE ASCENT WILL REMAIN NORTH OF
THE REGION. RETAINED TS CHANCES OVER THE SW WHERE NEGATIVE LI/POS MU
CAPE/AND DECENT HEATING IS EXPECTED. ANOTHER WEAK WAVE MAY SUPPORT A
FEW SHOWERS OVERNIGHT...WITH LOW POPS RETAINED ACROSS THE NW.
SATURDAY...LL BAROCLINIC ZONE WITH ACTIVE NW FLOW WILL PERSIST
SUPPORTING LOW CHANCES FOR SHRA IN THE PERIOD. RETAINED LOW
POPS...MAINLY NW AREAS FOR EXPECTED PASSING IMPULSES...OF WHICH
TIMING/STRENGTH REMAIN MUDDLED. ADJUSTED TEMPS...WITH A STRONG
NE/SW TEMP GRADIENT EXPECTED ACROSS THE FA. LOCATIONS NEAR THE
GENERAL AREA OF THE FRONT WILL HAVE THE POTENTIAL TO SEE
COOLER/WARMER TEMPS...WHICH WILL HINGE ON THE STRENGTH OF PASSING
IMPULSES AND THEIR REFLECTED N-S FRONTAL PERTURBATION.
&&
.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 303 AM MDT FRI MAY 2 2014
WEST TO SWRLY FLOW OVER THE REGION WILL START THE WEEK
WITH A VARIETY OF WEAK DISTURBANCES MOVING THROUGH...BRINGING PRECIP
CHANCES TO THE AREA. TOWARDS MID-WEEK DEEP TROF PUSHES TOWARDS THE
ROCKIES WITH STRONGER SWRLY FLOW DEVELOPING BRINGING GREATER
SHOWER/THUNDERSTORM CHANCES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY)
ISSUED AT 1127 AM MDT FRI MAY 2 2014
SCT -SHRA WITH ISOLD AFTERNOON AND EVENING -TSRA ARE EXPECTED
THRU THE FORECAST PERIOD. LCL MVFR VIS/CIGS WILL BE POSSIBLE IN
PRECIP.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...HELGESON
SHORT TERM...JC
LONG TERM...77
AVIATION...13
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
235 PM CDT FRI MAY 2 2014
.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 235 PM CDT FRI MAY 2 2014
MAIN FORECAST CONCERNS THIS PERIOD...CLOUDS/TEMPERATURES...SMALL
-SHRA CHANCES NORTHEAST OF I-94 SAT AND MAINLY NORTHEAST IA LATE
SAT NIGHT.
DATA ANALYSIS AT 18Z HAD A RATHER VIGOROUS MID LEVEL SHORTWAVE
DROPPING SOUTHEAST ACROSS MN. STRONGEST 3HR PRESSURE FALLS OF 2-3MB
WERE OVER CENTRAL MN WITH A SFC LOW/TROUGH AND COLD FRONT ALSO
DROPPING SOUTHEAST ACROSS MN. FORCING/LIFT AHEAD OF THESE FEATURES
RESPONSIBLE FOR A BAND OF -RA/-SHRA MOVING ACROSS WESTERN WI AND
NORTHEAST IA WITH SPOTTY -SHRA ACROSS EAST-CENTRAL/SOUTHEAST MN
BEHIND THE LEADING LINE. ANY RAIN AMOUNTS HAVE BEEN QUITE LIGHT.
SOME DECREASE OF CLOUDS BEHIND THE LEADING -RA/-SHRA LINE...WITH
MID-DAY TEMPS WARMING INTO THE 50S ACROSS CENTRAL IA TO CENTRAL MN.
02.12Z MODEL INITIALIZED QUITE WELL AND OFFER SIMILAR SOLUTIONS FOR
TONIGHT THRU SAT NIGHT AS HGTS ALOFT SLOWLY RISE BUT NORTHWEST FLOW
ALOFT PERSISTS OVER THE UPPER MIDWEST. TREND FAVORS STRONGER OF THE
EARLIER SOLUTIONS WITH THE SHORTWAVE QUICKLY PASSING THIS
AFTERNOON. TREND FOR SAT/SAT NIGHT FAVORS A COMPROMISE OF THE
EARLIER RUNS AS RIDGING ALOFT BUILDS INTO THE NORTHERN PLAINS AND
HGTS OVER THE REGION GRADUALLY START TO RISE. NO ONE DETERMINISTIC
MODEL FAVORITE AND WITH THE TIGHT CONSENSUS...FAVORED THE MODEL/
ENSEMBLE COMPROMISE THIS CYCLE. SHORT TERM FCST CONFIDENCE IS
GOOD THIS CYCLE.
IN THE SHORT TERM...GENERALLY DRIER WEATHER IN STORE FOR THE FCST
AREA TONIGHT THRU SAT NIGHT. SHORTWAVE WILL EXIT QUICKLY LATE
THIS AFTERNOON/EARLY THIS EVENING WITH DEEP LAYERED SUBSIDENCE/
DRYING SPREADING ACROSS THE AREA. ANY SCT SHRA/ISOLATED TSRA FROM
THIS AFTERNOON WILL DIMINISH/EXIT QUICKLY THIS EVENING WITH LOSS
OF THE MOISTURE AND DIURNAL HEATING. WILL FINE TUNE -SHRA CHANCES
FOR LATER THIS AFTERNOON/EARLY THIS EVENING BASED ON CURRENT
CONDITIONS AT MID AFTERNOON. IN THE WAKE OF THE SFC-MID LEVEL
TROUGH AND UNDER THE RISING HGTS ALOFT...WEAK CAN HIGH PRESSURE
BUILDS INTO THE UPPER MIDWEST FOR LATER TONIGHT INTO SAT NIGHT.
LATER THIS EVENING THRU SAT EVENING TRENDING DRY WITH THIS HIGH
PRESSURE OVER ALL BUT THE NORTHEAST END OF THE FCST AREA SAT
AFTERNOON. THIS DUE TO PROXIMITY OF A SHORTWAVE DROPPING SOUTHEAST
ACROSS LK SUPERIOR...STEEPER SFC- 700MB LAPSE RATES/WEAK
INSTABILITY AND A BIT MORE LINGERING 850-700MB MOISTURE. SMALL
-SHRA CHANCE NORTHEAST OF I-94 SAT AFTERNOON REASONABLE FOR NOW.
HIGH CONTINUES TO NOSE IN SAT NIGHT BUT SIGNAL REMAINS FOR A
MDT/STRONG SURGE OF 700-500MB WARM ADVECTION/ ISENTROPIC LIFT/
MOISTURE TRANSPORT WITH PW/S TO AROUND 0.75 INCH TO OVER- RUN THE
SOUTHWEST SIDE OF THE HIGH/COOL DOME LATE SAT NIGHT. THIS WITH
SOME 700-500MB FN CONVERGENCE AND DIVERGENCE ALOFT IN THE RIGHT
ENTRANCE REGION OF A 130KT 300MB JET MAX ACROSS WI. GIVEN THE
PERSISTENCE/CONSENSUS FOR THIS MOISTURE/LIFT SIGNAL...CONTINUED
THE SMALL -RA/-SHRA CHANCE ACROSS THE SOUTHWEST END OF THE FCST
AREA LATE SAT NIGHT.
COOLER NIGHT TONIGHT WITH A DECREASE OF CLOUDS FOR MUCH OF THE AREA
AND A COOLER LOW LEVEL AIRMASS SETTLING INTO THE REGION WITH THE
WEAK CAN HIGH PRESSURE. EVEN COOLER AIRMASS TO SETTLE IN FOR SAT
NIGHT...WITH LOWS FOR SAT NIGHT LOOKING TO BE MOSTLY IN THE 30S.
SOME FROST POSSIBLE ALONG/NORTHEAST OF I-94 SAT NIGHT BUT GIVEN
THE LATENESS OF THE SPRING SEASON...IT IS A BIT EARLY TO BE ISSUING
FROST ADVISORIES AT THIS POINT. PLAN IS TO START THOSE FOR MOST OF
THE FCST AREA NEXT WEEK. WITH PARTLY TO MOSTLY SUNNY SKIES SAT...
CONSENSUS HIGHS MOSTLY IN THE MID 50S TO LOW 60S LOOK GOOD.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 235 PM CDT FRI MAY 2 2014
MAIN FORECAST CONCERNS FOR SUNDAY THROUGH MONDAY NIGHT...-RA/-SHRA
CHANCES SUN MORNING AND AGAIN MON...TEMPERATURES THRU THE PERIOD.
MODELS IN DECENT AND IMPROVING AGREEMENT WITH SLOWLY RISING HGTS
OVER THE NORTH-CENTRAL CONUS IN THE SUN THRU MON NIGHT PERIOD.
LITTLE TREND FROM THE PREVIOUS RUNS IN THIS PERIOD AS FAR AS TIMING
OF FEATURES...THUS FCST CONFIDENCE IN THE SUN THRU MON NIGHT PERIOD
IS GENERALLY GOOD THIS CYCLE.
FORCING/LIFT/MOISTURE SIGNAL FROM LATE SAT NIGHT TRANSLATES QUICKLY
EAST/SOUTHEAST ACROSS THE SOUTHWEST 1/3 TO 1/2 OF THE FCST AREA SUN
MORNING. RATHER CONSISTENT SIGNAL AMONG THE MODELS FOR THIS MAINLY
700-500MB LIFT/MOISTURE TO PRODUCE SOME LIGHT PRECIP ACROSS THE
SOUTHWEST 1/2 OF THE FCST AREA WITH THE CONSENSUS 20-50 PERCENT -RA/
-SHRA CHANCES REASONABLE FOR NOW. TRENDED -RA CHANCES QUICKLY DOWN
AND OUT FOR THE AFTERNOON WITH THE FAST EXIT OF THE FORCING. DRY SUN
EVENING BUT ANOTHER ROUND OF MID LEVEL THERMO-DYNAMIC FORCING/LIFT
ASSOCIATED WITH A SHORTWAVE SLIDING THRU THE MID LEVEL RIDGE ALREADY
SPREADS INTO THE FCST AREA LATER SUN NIGHT. PW VALUES WITH THIS
ROUND OF FORCING/LIFT...INCLUDING SOME 300MB JET MAX RIGHT ENTRANCE
REGION DIVERGENCE...AGAIN IN THE 0.50 TO 0.75 INCH RANGE. GIVEN THE
PERSISTENCE/AGREEMENT ON THE FORCING/LIFT SIGNAL...CONTINUED THE
SMALL -RA CHANCE FOR MUCH OF THE FCST AREA LATER SUN NIGHT AND MON.
DRY/QUIET MON NIGHT WITH MID LEVEL RIDGE AXIS BUILD OVER THE UPPER
MIDWEST...NO 850-500MB FORCING/LIFT SEEN AND WEAK HIGH PRESSURE AT
THE SFC. 850MB TEMPS OVER THE AREA PROGGED TO REMAIN 0.5 TO 1
STANDARD DEVIATION BELOW NORMAL THRU THIS PERIOD. WITH PERIODIC
CLOUDS...SUN/MON HIGHS TO REMAIN ON THE SEASONABLY COOL SIDE. WITH A
COOLER/MOSTLY CLOUDY DAY SUNDAY THEN LIGHT WINDS AND PARTLY
CLOUDY SKIES MUCH OF SUN NIGHT...MOST MON MORNING LOWS LOOKING TO
BE IN THE 30S. GENERALLY STAYED WITH THE MODEL/ENSEMBLE CONSENSUS
HIGHS/LOWS FOR SUN THRU MON NIGHT.
FOR TUESDAY THROUGH FRIDAY.../DAYS 4 TO 7/...
MAIN CONCERNS ARE TEMPERATURES AND SHRA/TSRA CHANCES THRU THE PERIOD.
MEDIUM RANGE MODEL RUNS OF 02.00Z AND 02.12Z IN GOOD AND IMPROVING
AGREEMENT ON TUE...FOR STRONG TROUGHING TO DIG INTO THE ROCKIES AND
RIDGING ALOFT TO BUILD ACROSS THE MID/UPPER MS VALLEY. ECMWF/GFS
WITH SURPRISINGLY GOOD RUN-TO-RUN CONSISTENCY WITH THEIR 30.12Z AND
01.12Z RUNS ON TUE. 02.00Z ECMWF APPEARED AS AN OUTLIER WED/THU
BUT ITS 02.12Z RUN IS MORE IN LINE WITH THE GFS/CAN-GEM AND
PREVIOUS RUN CONSENSUS. SURPRISINGLY GOOD ECMWF/GFS AGREEMENT ON
FRI WITH BROAD LONG-WAVE TROUGHING OVER CENTRAL NOAM. DAY 4-7 FCST
CONFIDENCE IS GOOD TUE...THEN WITH SOME MODEL DETAIL DIFFERENCES
HAVING IMPACTS ON THE SENSIBLE WEATHER FOR WED AND BEYOND...FCST
CONFIDENCE FOR DAYS 5 THRU 7 IS AVERAGE.
TUE CONTINUES TO TREND TOWARD A DRY DAY WITH THE MID LEVEL RIDGE
AXIS MOVING ACROSS THE REGION....SFC HIGH PRESSURE OVER THE GREAT
LAKES AND THE MAIN AXIS OF 850MB WARM ADVECTION/MOISTURE TRANSPORT
WEST OF THE FCST AREA. WARMING 850MB TEMPS ON TUE SUPPORT HIGHS IN
THE 60S. MID LEVEL RIDGE AXIS IS QUICKLY PUSHED EAST TUE NIGHT...
WITH THE AREA UNDER SOUTHWEST FLOW ALOFT FOR WED-THU AS PIECES OF
ENERGY EJECT OUT OF THE WESTERN CONUS TROUGH. THIS EJECTING ENERGY
SENDS A RATHER STRONG COLORADO LEE LOW NORTHEAST ACROSS THE CENTRAL
PLAINS TOWARD THE UPPER MIDWEST. DIFFERENCES WHERE THE SFC LOW
AND ITS ASSOCIATED FRONTS AND WARM SECTOR END UP BY WED NIGHT/
THU. THIS HAS IMPACTS ON THE SENSIBLE WEATHER WED-THU AS FAR AS
TEMPS AND SHRA/TSRA CHANCES...DEPENDING ON WHERE THIS LOW TRACKS
AND THE FRONTS END UP. GIVEN THE AVERAGE CONFIDENCE BY WED/THU...
FOLLOWED THE MODEL/ENSEMBLE CONSENSUS WHICH WOULD TRACK THE LOW
INTO SOUTHERN MN BY EARLY THU. SHRA/TSRA CHANCES MOSTLY IN THE
30-50 PERCENT RANGE FOR TUE NIGHT THRU THU APPEAR REASONABLE AT
THIS TIME. LOWER/DECREASING SHRA/TSRA CHANCES THU NIGHT/FRI ALSO
APPEAR REASONABLE WITH THE MAIN SFC LOW/MID LEVEL TROUGH MOVING
EAST OF THE AREA. HOWEVER THERE ARE DETAIL DIFFERENCES WITH
SHORTWAVES IN THE WHAT WOULD BE BROAD TROUGHING OVER THE REGION
LATE IN THE WEEK. MODEL/ENSEMBLE CONSENSUS HIGHS/LOWS CLOSER TO
NORMAL FOR TUE-FRI LOOK WELL TRENDED FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1202 PM CDT FRI MAY 2 2014
WATER VAPOR SATELLITE LATE THIS MORNING SHOWS A SHORT WAVE TROUGH
OVER CENTRAL MINNESOTA MOVING QUICKLY SOUTHEAST. AT THE SURFACE...
LOW PRESSURE WAS ALSO OVER CENTRAL MINNESOTA BETWEEN KSAZ AND KJMR
WITH A FRONT/WIND SHIFT LINE SOUTH INTO NORTHWEST IOWA. A FEW
SHOWERS OUT AHEAD OF THE SURFACE LOW AND FRONT WITH VFR CEILINGS
AND NO VISIBILITY RESTRICTION. EXPECT THAT THESE WILL PASS THROUGH
EARLY THIS AFTERNOON AND THE QUESTION BECOMES IF MORE WILL DEVELOP
WITH THE PASSAGE OF THE SURFACE LOW AND FRONT. BOTH THE 02.00Z HI-
RES ARW AND 02.12Z NAM SUGGEST ADDITIONAL SCATTERED ACTIVITY COULD
DEVELOP SO WILL HOLD ONTO THE VCSH THROUGH THE AFTERNOON. THE
02.15Z RAP KEEPS THE INSTABILITY PRETTY LIMITED WITH MAYBE 150
J/KG OF MU CAPE SO WILL CONTINUE TO NOT INCLUDE ANY THUNDER
CHANCES UNLESS SOMETHING POPS UP. ONCE THE FRONT GOES THROUGH...
LOOK FOR THE WINDS TO COME AROUND TO THE NORTHWEST AND THE VFR
CEILINGS TO SCATTER OUT. VFR CONDITIONS THEN EXPECTED FOR THE
REMAINDER OF THE PERIOD WITH SOME GUSTY NORTHWEST WINDS FOR KRST
BY MID MORNING SATURDAY.
&&
.HYDROLOGY...
ISSUED AT 235 PM CDT FRI MAY 2 2014
RUNOFF FROM RECENT RAIN CONTINUES TO FLOW THROUGH THE MISSISSIPPI
RIVER TRIBUTARIES AND THE MAIN CHANNEL. CURRENTLY ONLY THE
MISSISSIPPI RIVER AT WABASHA IS IN FLOOD...BUT FORECASTS CONTINUE
TO POINT TO THE MISSISSIPPI RIVER AT WINONA...LA CROSSE...MCGREGOR
AND GUTTENBERG DAM 10 TO BEGIN MINOR FLOODING IN THE NEXT 1 TO 4
DAYS. IN ADDITION...THE BLACK RIVER NEAR GALESVILLE WI IS NEAR ITS
CREST JUST ABOVE FLOOD STAGE AND WILL FALL BACK BELOW FLOOD STAGE ON
SAT. NO MAJOR RAINS ARE ANTICIPATED OVER THE NEXT 5 DAYS SO RUNOFF
ALREADY IN THE RIVER CHANNELS WILL BE THE MAIN CONTRIBUTING FACTOR
TO RIVER LEVELS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....04
HYDROLOGY....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1202 PM CDT FRI MAY 2 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 240 AM CDT FRI MAY 2 2014
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO BRITISH COLUMBIA...AN
UPPER LOW AND SHORTWAVE TROUGH OVER NORTHERN ALBERTA/SASKATCHEWAN...
A SHORTWAVE TROUGH OVER SOUTHERN MANITOBA...AND AN ELONGATED LONG
WAVE TROUGH FROM TEXAS INTO THE GREAT LAKES. THE FORECAST AREA LIES
NOW IN SUBSIDENCE IN THE WAKE OF THE LONG WAVE TROUGH...PROMOTING
DRY AIR ADVECTION FROM THE NORTHWEST. THIS CAN BE SEEN BY THE LOW
STRATUS DECK CLEARING ACROSS MINNESOTA ON 11-3.9UM IMAGERY AND
SURFACE OBSERVATIONS. 00Z BIS AND ABR SOUNDINGS WERE ALSO QUITE DRY
WITH PRECIPITABLE WATER OF ONLY 0.3-0.4 INCHES. REPLACING THE
STRATUS DECK HAS BEEN MID AND HIGH CLOUDS SPREADING SOUTHEAST ACROSS
THE DAKOTAS AND MINNESOTA...AHEAD OF THE SHORTWAVE THERE. GRAND
FORKS RADAR DISPLAYING SOME LIGHT RETURNS AS WELL...BUT SO FAR THE
DRY AIR HAS BEEN WINNING OUT KEEPING THE PRECIPITATION AS VIRGA.
AIRMASS OVER THE FORECAST AT 00Z WAS STILL UNSEASONABLY COOL WITH
925MB TEMPS AROUND 4C...BUT WARMER 9-13C READINGS WERE LURKING
UPSTREAM AT ABR AND BIS. BEHIND THE SHORTWAVE TROUGH IN SOUTHERN
MANITOBA...SKIES CLEAR OUT AND SURFACE PRESSURES WERE RISING ABOUT 1
MB/HR...PROMOTING GUSTY WINDS ACROSS NORTH DAKOTA.
MODELS ARE IN GOOD AGREEMENT DROPPING THE SOUTHERN MANITOBA
SHORTWAVE SOUTHEASTWARD THROUGH THE FORECAST AREA THIS AFTERNOON.
MORE IMPORTANTLY...THERE IS A CONSISTENT SIGNAL FROM ALL MODELS FOR
THE SHORTWAVE TO WEAKEN SOME. THIS WEAKENING COMBINED WITH THE DRY
ADVECTION CURRENTLY TAKING PLACE FROM THE NORTHWEST BRINGS IN SOME
CONCERN FOR PRECIPITATION CHANCES TODAY. HARD TO FIND A MODEL THAT
DOESNT PRECIPITATE WITH THE SHORTWAVE...WHICH MAKES SENSE IN
GENERAL GIVEN WE HAVE A SHORTWAVE TROUGH COMING THROUGH AT PEAK
HEATING. BETWEEN DYNAMICS AND INSTABILITY FROM HEATING...SHOWERS
DEVELOPING IS REASONABLE. HOWEVER...IT IS WORTH NOTING THAT 2 METER
DEWPOINT GUIDANCE FROM THE BASE MODELS SUCH AS THE ECMWF...GFS...NAM
AND REGIONAL CANADIAN ALL PUSH DEWPOINTS WELL INTO THE 40S...WITH
EVEN THE GFS AND REGIONAL CANADIAN APPROACHING 50 BY 00Z. THIS SEEMS
A BIT HIGH GIVEN CURRENT SURFACE DEWPOINTS IN THE UPPER 20S TO MID
30S OVER THE DAKOTAS. PERHAPS THE MODELS ARE THINKING GREEN-UP HAS
ALREADY TAKEN PLACE BASED ON CLIMATOLOGY. WE DO HAVE WET SOILS SO
THAT COULD PROMOTE SLIGHTLY HIGHER DEWPOINTS. IN SUMMARY...FEEL
FAIRLY CONFIDENT THAT WE WILL SEE SHOWERS THIS AFTERNOON...BUT A
LITTLE LESS CERTAIN ON IF THEY WILL BE WIDESPREAD. ANOTHER CHANGE
WORTH NOTING IS THAT THE 02.00Z NAM MUCAPE THIS AFTERNOON HAS
DROPPED FROM PREVIOUS RUNS...NOW BELOW 200 J/KG...WHICH MAKES SENSE.
CONSIDERED DROPPING THE THUNDER MENTION ENTIRELY AS A RESULT...BUT
THE RAP DOES DEPICT A ZONE OF 700-500MB LAPSE RATES APPROACHING 7
C/KM OVER THE FORECAST AREA DURING THE AFTERNOON. THEREFORE...HAVE
LEFT THE THUNDER IN THE FORECAST FOR THE AFTERNOON. ANY SHOWER
ACTIVITY SHOULD QUICKLY EXIT THE AREA BETWEEN 00-03Z WITH THE
SHORTWAVE EXITING AND DIURNAL COOLING.
AS WE APPROACH LATE TONIGHT...MORE SHOWER ACTIVITY LOOKS TO DROP
DOWN INTO NORTHERN MN AND WI. THESE ARE AHEAD OF THE SHORTWAVE
TROUGH AND UPPER LOW CURRENTLY IN NORTHERN ALBERTA/SASKATCHEWAN...
PROGGED TO BE OVER SOUTHERN MANITOBA AND NORTHERN MN BY 12Z
SATURDAY. ITS POSSIBLE THIS SHOWER ACTIVITY COULD GET INTO TAYLOR
COUNTY TOWARDS 12Z...BUT FOR NOW HAVE KEPT THE FORECAST DRY.
925MB TEMPERATURES ARE PROGGED A FEW DEGREES WARMER TODAY...BETWEEN
6-8C FOR THE AFTERNOON HOURS. THERE IS A CHANCE WE CAN SNEAK IN A
LITTLE SUN AND WITH A WARM ADVECTING SOUTHWEST WIND...MOST LOCATIONS
WILL CLIMB INTO THE 50S. THERES EVEN A CHANCE SOME SPOTS COULD PUSH
60...SUCH AS CHARLES CITY...WINONA...LA CROSSE AND BOSCOBEL. THIS
ALL HINGES IF WE CAN GET MORE SUN...BUT THINK OVERALL WE WILL BE
CLOUDY OR MOSTLY CLOUDY TODAY. COLD ADVECTION TONIGHT ON A NORTHWEST
WIND...WHICH COULD BE BRISK IN THE EVENING WEST OF THE MS RIVER WITH
THE PRESSURE RISE COMING THROUGH...WILL ALLOW TEMPERATURES TO DROP
INTO THE 30S TO LOW 40S TONIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 240 AM CDT FRI MAY 2 2014
UPPER LEVEL PATTERN CHANGE REMAINS ON TRACK DURING THE LONG TERM
PERIOD...WITH UPPER RIDGING CURRENTLY OVER THE WESTERN U.S. PROGGED
TO BUILD OVER THE REGION LATE TUESDAY INTO WEDNESDAY. THIS IS ALL IN
RESPONSE TO AN UPPER LOW CURRENTLY OFF THE PACIFIC NORTHWEST COAST
SUGGESTED TO DIG INTO THE SOUTHWESTERN U.S.. THIS PATTERN CHANGE
MEANS A GRADUAL MODERATION OF TEMPERATURES...ALONG WITH POTENTIAL
FOR MORE ACTIVE WEATHER AS WE APPROACH THE MIDDLE OF NEXT WEEK.
FIRST OFF...SATURDAY. THAT NEXT SHORTWAVE TROUGH AND UPPER LOW
CURRENTLY IN NORTHERN ALBERTA/SASKATCHEWAN WILL SLIDE ACROSS
NORTHERN PORTIONS OF MN AND WI...ALONG WITH UPPER MI AND ONTARIO
DURING THE DAY AND EVENING HOURS. THIS TRACK KEEPS THE BEST DPVA
FORCING NORTH OF THE FORECAST AREA. THEREFORE...THINK MUCH OF THE
PRECIPITATION WILL STAY NORTH AS WELL. HOWEVER...THERE WILL BE A
SURFACE COLD FRONT ACCOMPANYING THE SHORTWAVE. THE 02.00Z GFS PRINTS
OUT SOME LIGHT QPF OVER LA CROSSE AS THE FRONT COMES THROUGH...
MOSTLY A RESULT OF THE MODEL DEVELOPING SOME WEAK CAPE. BELIEVE THE
MODEL IS TOO FAR SOUTH AND OVERLY MOIST. HAVE DECIDED TO KEEP ANY
LOW CHANCES OF PRECIPITATION NORTH OF I-94...CONSISTENT TOO WITH THE
02.00Z ECMWF. 925MB TEMPS REBOUND DECENTLY ON SATURDAY...6-9C...
ALLOWING TEMPERATURES TO CLIMB SLIGHTLY HIGHER THAN THOSE TODAY.
NEXT UP IS ON SUNDAY WHERE THE 02.00Z GFS/CANADIAN/ECMWF/NAM ALL
DEVELOP A FRONTOGENETICAL BAND OF PRECIPITATION. THE BAND ALSO HAS
SOME RIGHT ENTRANCE REGION FORCING FROM A JET STREAK FOLLOWING THE
SATURDAY SHORTWAVE TROUGH. THE NAM IS THE ODD MODEL OUT ON LOCATION
OF THE BAND...TRACKING IT FROM MINNEAPOLIS TO LA CROSSE AND THE
DELLS...WHEREAS ALL OTHER MODELS SUGGEST SOUTHWEST MN INTO NORTHERN
IA AND NORTHERN IL AS THE MORE LIKELY TRACK. GIVEN GOOD AGREEMENT ON
THIS FRONTOGENETIC BAND FROM THE OTHER MODELS...HAVE RAISED
PRECIPITATION CHANCES. MODEL CONSENSUS SUGGESTS 12-18Z SUNDAY IS THE
MOST LIKELY TIME PERIOD FOR PRECIPITATION WITH THE PRECIPITATION
EXITING RAPIDLY TO THE SOUTHEAST IN THE AFTERNOON. THERE IS SOME
LOWER LEVEL DRY AIR PRESENT...WHICH IF THE PRECIPITATION WAS HEAVIER
MIGHT CAUSE PRECIPITATION TYPE ISSUES FROM EVAPORATIVE COOLING. FOR
NOW WILL KEEP THE PRECIPITATION TYPE AS RAIN GIVEN GENERALLY LIGHT
QPF PROGGED BUT SOMETHING TO WATCH. WITH THIS FRONTOGENETICAL BAND
GOING THROUGH AND A NORTHEAST BREEZE...TEMPERATURES ARE GOING TO
TAKE A COOL DOWN. THIS IS ESPECIALLY TRUE UNDER THE PRECIPITATION.
RAIN CHANCES COME BACK FOR MONDAY WHEN YET ANOTHER BAND OF
FRONTOGENESIS AND ISENTROPIC LIFT MOVES ACROSS. THIS ONE LOOKS
WEAKER THAN ON SUNDAY...THUS 02.00Z GFS/CANADIAN/ECMWF QPF IS
LIGHTER AND MORE SPREAD OUT ACROSS THE FORECAST AREA. CONSENSUS 20
PERCENT CHANCES SEEM REASONABLE. COOLED HIGHS SLIGHTLY FROM THE
PREVIOUS FORECAST DUE TO CLOUDS AND AN EAST WIND AROUND HIGH
PRESSURE IN UPPER MI. THESE COULD NEED FURTHER COOLING IF A LITTLE
MORE PRECIPITATION IS AROUND AS SUGGESTED BY THE 02.00Z ECMWF.
AS THE UPPER RIDGE BUILDS INTO THE AREA LATE TUESDAY AND ESPECIALLY
WEDNESDAY...THAT IS WHEN SOME BIGGER TEMPERATURE CHANGES TAKE
PLACE...ALONG WITH INCREASING CONCERNS FOR CONVECTION AND POSSIBLE
SEVERE WEATHER. 02.00Z GFS/ECMWF SUGGEST THAT BETWEEN 12Z WEDNESDAY
AND 00Z THURSDAY...925MB TEMPS COULD CLIMB AS MUCH AS 10-15C
RESULTING IN AN ALMOST SUMMER-LIKE AIRMASS COMING INTO LOCATIONS
ALONG AND SOUTH OF I-90. WE WILL HAVE TO WAIT AND SEE HOW THIS PANS
OUT. IN ANY EVENT...HAVE FOLLOWED CONSENSUS WITH 30-50 PERCENT
CHANCES FOR TUESDAY NIGHT AND WEDNESDAY...WITH SLIGHTLY HIGHER
CHANCES FOR WEDNESDAY NIGHT INTO THURSDAY RESULTING FROM A SHORTWAVE
TROUGH COMING THROUGH THE UPPER MIDWEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1202 PM CDT FRI MAY 2 2014
WATER VAPOR SATELLITE LATE THIS MORNING SHOWS A SHORT WAVE TROUGH
OVER CENTRAL MINNESOTA MOVING QUICKLY SOUTHEAST. AT THE
SURFACE...LOW PRESSURE WAS ALSO OVER CENTRAL MINNESOTA BETWEEN
KSAZ AND KJMR WITH A FRONT/WIND SHIFT LINE SOUTH INTO NORTHWEST
IOWA. A FEW SHOWERS OUT AHEAD OF THE SURFACE LOW AND FRONT WITH
VFR CEILINGS AND NO VISIBILITY RESTRICTION. EXPECT THAT THESE WILL
PASS THROUGH EARLY THIS AFTERNOON AND THE QUESTION BECOMES IF MORE
WILL DEVELOP WITH THE PASSAGE OF THE SURFACE LOW AND FRONT. BOTH
THE 02.00Z HI-RES ARW AND 02.12Z NAM SUGGEST ADDITIONAL SCATTERED
ACTIVITY COULD DEVELOP SO WILL HOLD ONTO THE VCSH THROUGH THE
AFTERNOON. THE 02.15Z RAP KEEPS THE INSTABILITY PRETTY LIMITED
WITH MAYBE 150 J/KG OF MU CAPE SO WILL CONTINUE TO NOT INCLUDE ANY
THUNDER CHANCES UNLESS SOMETHING POPS UP. ONCE THE FRONT GOES
THROUGH...LOOK FOR THE WINDS TO COME AROUND TO THE NORTHWEST AND
THE VFR CEILINGS TO SCATTER OUT. VFR CONDITIONS THEN EXPECTED FOR
THE REMAINDER OF THE PERIOD WITH SOME GUSTY NORTHWEST WINDS FOR
KRST BY MID MORNING SATURDAY.
&&
.HYDROLOGY...
ISSUED AT 240 AM CDT FRI MAY 2 2014
RUNOFF FROM RECENT RAIN CONTINUES TO FLOW THROUGH THE MISSISSIPPI
RIVER TRIBUTARIES AND THE MAIN CHANNEL. CURRENTLY ONLY THE
MISSISSIPPI RIVER AT WABASHA IS IN FLOOD...BUT FORECASTS CONTINUE
TO POINT TO THE MISSISSIPPI RIVER AT WINONA...LA CROSSE...MCGREGOR
AND GUTTENBERG DAM 10 TO BEGIN MINOR FLOODING IN THE NEXT 1 TO 4.5
DAYS. IN ADDITION...THE BLACK RIVER AT GALESVILLE IS APPROACHING
FLOOD STAGE...BUT SHOULD NOT CLIMB MUCH ABOVE MINOR FLOOD WITH
FALLING RIVER LEVELS AT BLACK RIVER FALLS. NO MAJOR RAINS ARE
ANTICIPATED OVER THE NEXT 5 DAYS SO RUNOFF WILL BE THE MAIN
CONTRIBUTING FACTOR TO RIVER LEVELS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
HYDROLOGY...AJ