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Area Forecast Discussion
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000
FXUS61 KPHI 240152
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
952 PM EDT WED APR 23 2014

.SYNOPSIS...
A HIGH PRESSURE SYSTEM LOCATED OVER THE GREAT LAKES REGION THIS
AFTERNOON WILL BUILD SOUTH AND EAST THEN ACROSS OUR REGION
THROUGH FRIDAY AND THEN WEAKEN FRIDAY NIGHT. A LOW PRESSURE SYSTEM
WILL MOVE NORTH OF THE AREA FRIDAY NIGHT AND SATURDAY. ITS
ASSOCIATED FRONT WILL CROSS THE REGION EARLY SATURDAY. MORE HIGH
PRESSURE WILL ARRIVE FOR SUNDAY AND SUNDAY NIGHT. AN UNSETTLED
PATTERN WILL SET UP FOR NEXT WEEK.

&&

.NEAR TERM /THROUGH THURSDAY/...
NO CHANGES TO THE OVERALL FORECAST THUS FAR TONIGHT. ONLY MADE
SOME HOURLY CHANGES, THE BIGGEST THING BEING AN INCREASE IN CLOUD
COVER THIS EVENING BEFORE CLEARING OVERNIGHT.

SURFACE HIGH PRESSURE BUILDING SOUTHWARD OUT OF CANADA AND ACROSS
THE GREAT LAKES REGION, IS TRYING TO PUSH EAST. THIS HIGH AND THE
SURFACE LOW OFF THE NEW ENGLAND COAST WILL KEEP A TIGHT GRADIENT
ACROSS THE AREA ALONG WITH SOME COLD AIR ADVECTION.

IT WILL BE A COLD NIGHT WITH MINIMUM WINDS CHILLS IN THE TEENS AND 
20S. ACTUAL AIR TEMPERATURES WILL BE IN THE MID 20S ON THE LOW END 
TO UPPER 30S ON THE HIGH END. SKIES WILL BE CLEAR.

MOST OF THE DEFINED SPRING GROWING AREA, FOR THE THIRD WEEK OF 
APRIL, WILL BE IN THE MID TO UPPER 30S OVERNIGHT. WE WILL NOT BE 
ISSUING A FREEZE WARNING. THERE IS PATCHY FROST IN THE GRIDS, BUT WE 
ALSO FEEL THE WIND WILL PRECLUDE ANY WIDESPREAD FROST. A FROST 
ADVISORY WILL NOT BE ISSUED EITHER AT THIS TIME.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH 6 PM THURSDAY/...
WITH THE SURFACE HIGH BUILDING ACROSS THE REGION TOMORROW AND THE 
COLD AIR ADVECTION SHUTTING OFF, TEMPERATURES WILL REBOUND NICELY. 
HIGHS WILL BE IN THE 50S ACROSS THE NORTH AND WEST, AND IN THE LOWER 
TO MID 60 ELSEWHERE. STILL, A FEW DEGREES BELOW NORMAL.

SKIES WILL BE MAINLY CLEAR. 

NORTHWEST WINDS WILL BE IN THE 15 TO 25 MPH RANGE.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDS INTO THE REGION THURSDAY NIGHT AND EARLY
FRIDAY IN ADVANCE OF AN APPROACHING STORM SYSTEM AND ASSOCIATED
FRONT.  

THE LOW PRESSURE SYSTEM PASSES BY TO OUR NORTH. AND THE ASSOCIATED FRONT
SWINGS THROUGH THE REGION FRIDAY NIGHT INTO EARLY SATURDAY.
INSTABILITY LOOKS LIMITED ENOUGH TO KEEP MENTION OF THUNDER OUT OF
THE FORECAST...CONSISTENT WITH THE PREVIOUS FORECAST. LAST TWO GFS
RUNS SUGGEST SOME PRECIPITATION MOVING THROUGH THE REGION AS UPPER
TROUGH ROTATES THROUGH DURING THE DAY SATURDAY SO EXTENDED CHANCE
POPS FURTHER SOUTH ACROSS THE AREA. NO OTHER CHANGES OF
SIGNIFICANCE TO THE PREVIOUS FORECAST.

MET/MAV BLEND WAS USED FOR TEMPERATURES IN THURSDAY NIGHT INTO
FRIDAY NIGHT TIME FRAME.

FAIR WEATHER MOVES BACK INTO THE REGION, FOR SATURDAY NIGHT AND
CONTINUES INTO EARLY MONDAY.

MODELS CONTINUE TO ADVERTISE PATTERN CHANGE WITH INCREASED
BLOCKING, SLOWING STORMS SYSTEMS DOWN. REMAINDER OF EXTENDED
FORECAST PERIOD WILL BE IMPACTED BY APPROACH OF SLOW MOVING STORM
SYSTEM TO OUR WEST. SLOW SPEED AND SIGNIFICANT TAPPING OF GULF AND
ATLANTIC MOISTURE SUGGEST THIS WILL BE A VERY WET STORM SYSTEM FOR
SOME LOCATIONS. AND THAT COULD WIND UP INCLUDING US. 

WPC TEMPS/POPS WERE USED AS PRIMARY INPUT FOR THE GRIDS IN THE
SATURDAY THROUGH WEDNESDAY TIME FRAME. 

I VERY SELDOM PUT POPS HIGHER THAN 50% OUT IN DAY 7. BUT GIVEN
CONSISTENT MODEL SIGNAL OVER PAST SEVERAL DAYS AS WELL AS WPC
GUIDANCE, TODAY I DID.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, 
KMIV, KACY AND SURROUNDING AREAS.

VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WE'LL HAVE STRATOCU 
INTO THE EVENING HOURS, THEN GO CLEAR. SKIES SHOULD REMAIN MAINLY 
CLEAR TOMORROW.

THE ONLY ISSUE FOR TONIGHT AND TOMORROW WILL EB THE WIND. NORTHWEST 
WINDS WILL SLACKEN A BIT FROM THIS AFTERNOON'S LEVELS, BUT STILL 
GUST TO 25 KT. 

OUTLOOK...
THU NIGHT THROUGH FRI MORNING...VFR EXPECTED. 
FRI AFTERNOON THROUGH SAT...MOSTLY VFR WITH SCT SHOWERS POSSIBLE.
SAT NGT THRU MON...MOSTLY VFR.

&&

.MARINE...
PER OBSERVATIONS AND FORECASTS SOUNDINGS, A GALE WARNING REMAINS IN 
PLACE FOR THE DELAWARE BAY THROUGH MIDNIGHT. THE GALE WARNING WILL 
REMAIN IN PLACE FOR THE OCEAN THROUGH MIDDAY TOMORROW. ADDITIONAL 
SMALL CRAFT ADVISORY HEADLINES WILL BE NEEDED THEREAFTER, POSSIBLY 
INTO TOMORROW EVENING.

OUTLOOK...
THU NIGHT THRU MON...MOSTLY SUB-SCA CONDITIONS. NEAR SCA GUSTS
FRI AFTERNOON/EVENING.

&&

.FIRE WEATHER...
WITH THE CLOUD COVER ACROSS THE AREA TODAY, TEMPERATURES NEVER GOT
A CHANCE TO WARM MUCH AND DEWPOINTS WERE UNABLE TO DROP MUCH UNTIL
VERY LATE IN THE AFTERNOON WHEN SOME PARTIAL CLEARING TOOK PLACE.
THEREFORE, THE WARNING FOR TODAY HAS BEEN CANCELLED. 

THIS WILL BE DIFFERENT ON THURSDAY. WITH WARMER TEMPERATURES
EXPECTED, A DEEPER MIXED LAYER, AND LOWER DEWPOINTS, AFTERNOON
HUMIDITY VALUES WILL DROP INTO THE TEENS AND 20S. WINDS MAY BE A
LITTLE WEAKER ON THURSDAY COMPARED TO WEDNESDAY, BUT WE STILL
EXPECT SUSTAINED WINDS AT LEAST 15-20 MPH WITH GUSTS 25-30 MPH. THE
FUEL MOISTURE LEVELS WILL CONTINUE TO BE LOW AS WELL. ALL THREE
CRITERIA (WIND, FUELS, RH'S) SHOULD BE MET, SO WE WILL UPGRADE THE
WATCH TO WARNING ON THURSDAY.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...RED FLAG WARNING FROM 10 AM TO 8 PM EDT THURSDAY FOR PAZ054-
     055-060>062-070-071-101>106.
NJ...RED FLAG WARNING FROM 10 AM TO 8 PM EDT THURSDAY FOR NJZ001-
     007>010-012>027.
DE...RED FLAG WARNING FROM 10 AM TO 8 PM EDT THURSDAY FOR 
     DEZ001>004.
MD...RED FLAG WARNING FROM 10 AM TO 8 PM EDT THURSDAY FOR MDZ008-
     012-015-019-020.
MARINE...GALE WARNING UNTIL NOON EDT THURSDAY FOR ANZ450>455.
     SMALL CRAFT ADVISORY UNTIL NOON EDT THURSDAY FOR ANZ430-431.
     GALE WARNING UNTIL MIDNIGHT EDT TONIGHT FOR ANZ430-431.

&&

$$
SYNOPSIS...SZATKOWSKI
NEAR TERM...KRUZDLO/ROBERTSON
SHORT TERM...KRUZDLO
LONG TERM...SZATKOWSKI
AVIATION...SZATKOWSKI/KRUZDLO
MARINE...SZATKOWSKI/KRUZDLO
FIRE WEATHER...






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