Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KPHI 150126
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
926 PM EDT MON APR 14 2014

.SYNOPSIS...
A STRONG LATE SEASON COLD FRONT IS EXPECTED TO ARRIVE IN THE REGION
TOMORROW AFTERNOON. BEHIND IT, HIGH PRESSURE SHOULD SETTLE IN OVER
OUR REGION THROUGH THE REMAINDER OF THE WORK WEEK. ANOTHER LOW
PRESSURE SYSTEM AND A WEAK COLD FRONT IS EXPECTED TO PROPAGATE OVER
THE REGION ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
HIGH PRESSURE PARKED WELL OFFSHORE AND LOW PRESSURE MOVING DOWN THE
SAINT LAWRENCE VALLEY WILL CONTINUE TO PRODUCE A GUSTY SRLY FLOW
OVER THE REGION TONIGHT. SOUTH WINDS WILL GUST BETWEEN 20 AND 30 MPH
THIS EVENING...BEFORE DECREASING SOMEWHAT OVERNIGHT. IT WILL REMAIN
MILD AND INCREASINGLY HUMID OVERNIGHT. LOWS WILL ONLY BOTTOM OUT IN
THE MID/UPPER 50S ACROSS THE NRN AREAS AND LOW 60S ACROSS THE
DELMARVA AND PHILLY METRO AREAS. MUCH OF THE NIGHT WILL BE
RAIN-FREE...BUT SCT SHOWERS ARE POSSIBLE TOWARDS DAWN...MOSTLY N/W.

DID NOT MAKE ANY MAJOR CHANGES FOR THE LATE EVE UPDATE.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
ACTIVE WEATHER DAY EXPECTED. A STRONG COLD FRONT ATTACHED TO THE
AFOREMENTIONED LOW WILL BE APPROACHING FROM THE WEST EARLY. IT WILL
CROSS THE REGION DURING THE AFTERNOON AND BRING SHOWERS AND SCT
TSTMS. WHILE WE ARE NOT EXPECTING ANY SVR TSTMS PRESENTLY...SOME
STORMS WILL BE CAPABLE OF TAPPING THE LOW LEVEL JET AND BRINGING
SOME NEAR-SVR GUSTS. HEAVY RAINS ARE EXPECTED TUE WITH MOST AREAS
RECEIVING AROUND AN INCH OF RAIN DURING THE DAYLIGHT HOURS. AREAS
ACROSS THE SRN POCONOS GET CLOSER TO 1.5 INCHES OF  RAIN...BUT EVEN
THESE VALUES WILL NOT BE ENOUGH TO CAUSE ANY HUGE HYDRO CONCERNS.
LOCALIZED POOR DRAINAGE FLOODING IS STILL POSSIBLE WITH ANY TSTMS.

TEMPERATURES WHICH WILL BE VERY WARM AT THE BEGINNING OF THE DAY
WILL DROP 20-25 DEGREES AFTER THE FRONTAL PASSAGE. BY EARLY
EVENING...TEMPERATURES WILL BE ONLY IN THE LOW/MID 40S UP NORTH AND
IN THE LOW/MID 50S OVER SRN NJ AND THE DELMARVA. WINDS WILL SHIFT TO
WRLY DURING THE AFTERNOON AND GUST UP TO 25 TO 30 MPH.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
PRECIPITATION SHOULD COME TO A QUICK END BY MIDNIGHT FOR MOST
LOCATIONS, THOUGH LINGERING SHOWERS TO SUNRISE WILL BE POSSIBLE
ALONG THE SHORE.

FREEZE CONCERNS...WITH THE STRONG POST FRONTAL COLD AIR ADVECTION,
EXPECT MOST OF THE REGION, WITH THE EXCEPTION OF THE SOUTHERN
DELMARVA REGION AND LOCATIONS ALONG THE SHORE, TO SEE TEMPERATURES
AT OR BELOW FREEZING. ALTHOUGH GUIDANCE MAY BE A BIT TOO COOL IN
UNDERESTIMATING OVERNIGHT MIXING WITH THE WINDY CONDITIONS, EVEN
UNDERCUTTING GUIDANCE RESULT IN A WIDESPREAD FREEZE. THUS HAVE
ISSUED A FREEZE WATCH FROM NORTHERN DELMARVA UP TO BERKS, BUCKS,
AND MERCER COUNTIES. LOCATIONS NORTH OF THE WATCH ARE LIKELY TO
SEE A FREEZE AS WELL, HOWEVER, IT IS STILL EARLIER THAN THE MEDIAN
LAST FREEZE DATE, SO WILL NOT ISSUE A WATCH FOR THESE LOCATIONS.

WIND CONCERNS...STILL A CONCERN FOR AN ISOLATED GUST TO 40 OR 45
MPH. HOWEVER, WITH THE MODELS STILL TRENDING TOWARDS A LATE
AFTERNOON FRONTAL PASSAGE FOR MOST LOCATIONS, THE WINDOW OF
OPPORTUNITY FOR THAT SHOULD BE RATHER BRIEF, AS THE PEAK PRESSURE
RISES WILL BE BEFORE 03Z.

WEDNESDAY AND WEDNESDAY NIGHT...IT REMAINS COOL. TEMPERATURES WILL
BE 10 TO 15 DEGREES BELOW NORMAL DURING THE DAY. CLEARING SKIES
AND DECREASING WINDS WILL SET THE STAGE FOR PRIME RADIATIONAL
COOLING CONDITIONS WEDNESDAY NIGHT, MEANING MANY LOCATIONS MAY SEE
LOWER TEMPERATURES WEDNESDAY NIGHT THAN TUESDAY NIGHT.

THURSDAY AND FRIDAY...SHOULD SEE A MODEST WARMING TREND THROUGH
THIS PERIOD AS THICKNESSES INCREASE. MOS HAS A SLIGHT CHANCE FOR
PRECIPITATION FOR MUCH OF THE REGION THURSDAY, BUT GIVEN THE
SURFACE HIGH, AND POSSIBLE SHORT WAVE RIDGING IN THE UPPER LEVELS,
THIS SEEMS UNLIKELY.

SATURDAY THROUGH MONDAY...STILL LOTS OF MODEL DISAGREEMENT AND
ENSEMBLE SPREAD THROUGH THIS PERIOD. THE OPEN WAVE UPPER LEVEL
TROUGH AND ASSOCIATED SURFACE LOW IS EXPECTED TO CROSS THE EASTERN
U.S. THROUGH THE WEEKEND, BECOMING MORE OF A DOUBLE BARRELED LOW
AS IT DOES SO. THE QUESTION IS IF THE SOUTHERN STREAM OR THE
NORTHERN STREAM LOW WILL BECOME THE DOMINANT FEATURE. IF THE
NORTHERN STREAM LOW INTENSIFIES, IT WILL LIKELY HAVE MORE OF AN
IMPACT FOR OUR REGION, PRIMARILY IN THE FORM OF PRECIPITATION
CHANCES. GIVEN THE UNCERTAINTY, HAVE STAYED CLOSE TO THE PREVIOUS
FORECAST AND HPC GUIDANCE THROUGH THIS PERIOD.

&&

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

GUSTY WINDS AND VFR CONDITIONS WILL BE ACROSS THE TERMINALS THIS
EVENING. CLOUDS WILL INCREASE OVERNIGHT...BUT ANY LOWER CIGS WILL
NOT ARRIVE UNTIL AFTER MIDNIGHT (FOR THE MOST PART). A COLD FRONT
WILL APPROACH FROM THE WEST TUESDAY...SO THE LOWER CLOUDS AND
SHOWERS WHICH WILL ARRIVE WITH THE FRONT WILL BE ACROSS THE AREA TUE
MORNING AND INTO THE AFTERNOON. WIDESPREAD LOW MVFR OR IFR IS
EXPECTED. GUSTY SRLY/SERLY WINDS TONIGHT WILL SHIFT TO SE TUE
MORNING AND THEN SHIFT WRLY DURING THE AFTERNOON. SFC GUSTS TO 25 TO
30 KTS WILL OCCUR THRU THE PERIOD. LLWS WAS ADDED TO THE FCST FOR
TUE MORNING AS A DECENT 60-70 KT LOW LEVEL JET WILL ARRIVE ACROSS
THE AREA. TSTMS ARE POSSIBLE TUE...BUT NOT CONFID ENOUGH YET TO
INCLUDE IN TAFS.

LATEST GUIDANCE FOR THE 00Z TAF PKG IS MORE PESSIMISTIC THAN PREV.
HAVE TRENDED TWD A MORE IFR SOLN ON TUE. WILL HAVE TO SEE HOW THIS
PLAYS OUT. STILL WENT ABV MOST GUID WHICH INDICATED WIDESPREAD
LIFR.

OUTLOOK...

TUESDAY NIGHT...CONDITIONS GRADUALLY IMPROVING TO VFR BEHIND THE
FRONT. GUSTY NORTHWESTERLY WINDS EXPECTED FOR MUCH OF THE NIGHT.

WEDNESDAY THROUGH FRIDAY...MAINLY VFR CONDITIONS EXPECTED.

FRIDAY NIGHT...MVFR CONDITIONS IN -SHRA ARE POSSIBLE.

&&

.MARINE...
WE INTEND TO KEEP THE MARINE FLAGS AS THEY ARE FOR THIS FCST
CYCLE. SCA CONDITIONS ARE PRESENTLY ACROSS ALL THE WATERS WITH
GUSTS IN THE 25 TO 34 KT RANGE AT THE BUOYS. SEAS ARE 4 FT AT
44009...BUT SILL SHORTLY BUILD CLOSER TO 5-6 FT INTO THE EVENING.
A FEW GALE GUSTS ARE POSSIBLE TUE AS THE FRONT APPROACHES...BUT WE
WILL JUST KEEP THE GALE WATCH FOR NOW AND GIVE THE NEXT CREW
ANOTHER LOOK AT IT. FAIR WEATHER THIS EVENING...THEN SCT SHOWERS
TONIGHT. SHOWERS/SCT TSTMS ON TUE WITH GUSTY WINDS AND ROUGH SEAS.

OUTLOOK...

TUESDAY NIGHT AND WEDNESDAY MORNING...STRONG NORTHWESTERLY WINDS
WITH GALE FORCE GUSTS ARE EXPECTED. THE GALE WATCH FOR THIS PERIOD
CONTINUES.

WEDNESDAY AFTERNOON THROUGH FRIDAY...BREEZY NORTHEASTERLY FLOW IS
EXPECTED THROUGH THIS PERIOD, WITH CONDITIONS AT OR JUST BELOW
SMALL CRAFT ADVISORY CONDITIONS.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FREEZE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING
     FOR PAZ060-070-071-101>104-106.
NJ...FREEZE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING
     FOR NJZ015>019-021.
DE...FREEZE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING
     FOR DEZ001.
MD...FREEZE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING
     FOR MDZ008-012.
MARINE...GALE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING FOR
     ANZ430-431-450>455.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ430-431-
     450>455.

&&

$$
SYNOPSIS...JOHNSON
NEAR TERM...NIERENBERG/O`HARA
SHORT TERM...O`HARA
LONG TERM...JOHNSON
AVIATION...JOHNSON/NIERENBERG/O`HARA
MARINE...JOHNSON/O`HARA






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.