Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 010424
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1224 AM EDT WED OCT 1 2014

.SYNOPSIS...
LOW PRESSURE IN PENNSYLVANIA WILL REDEVELOP SOUTHEAST OF NEW ENGLAND
LATE TODAY THROUGH THURSDAY. STRENGTHENING HIGH PRESSURE IN EASTERN
CANADA WEDGES DOWN INTO THE MID ATLANTIC STATES LATER TODAY THROUGH
THURSDAY. THE HIGH WILL SLIDE TO OUR EAST FRIDAY WITH A POTENT COLD
FRONT MOVING THROUGH OUR AREA FRIDAY NIGHT INTO SATURDAY MORNING.
ANOTHER COLD FRONT PASSES BY NEXT MONDAY.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
TROUGH AXIS SHOWERS AND TSTMS IN EASTERN PA TO CHESAPEAKE BAY AT
MIDNIGHT WILL ROTATE EASTWARD INTO SOUTH PA...NE MD DURING THE
NIGHT WHILE THE NORTHERN PORTION IS STATIONARY WEST OF HAZELTON. THIS
IN RESPONSE TO STEERING WIND FIELDS ALOFT...WESTERLY FLOW TO THE
SOUTH AND NEARLY E OR SE FLOW N OF 178.

ALSO LOW TOP SHOWERS WITH SIGNIFICANT INTENSITY ARE SWEEPING
WESTWARD OFF THE ATLANTIC INTO NE NJ.

POPS AND WX HAVE BEEN ADJUSTED OVERNIGHT...REFLECTING HIGHER POPS
NE NJ.

MODELS ARE NOW CARRYING UNSTABLE SWI`S ACROSS NJ OVERNIGHT AND WED
MORNING AND IT WILL NOT SURPRISE TO SEE SHOWERS BECOME MORE
WIDESPREAD OVER THE FCST AREA BY DAWN.

MODEL QPF HAS JUST NOT BEEN VERY GOOD IN THIS INFREQUENTLY
OCCURRING PATTERN.

GUIDANCE WAS ALSO INDICATING THE POTENTIAL FOR PATCHY FOG, AND WE
KEPT THIS IN THE FORECAST WITH THE EAST-NORTHEAST FLOW AND AMPLE
MOISTURE. FOR OVERNIGHT TEMPERATURES, WE MOSTLY TOOK A BLEND OF
MET/MAV GUIDANCE AND EXPECT LOWS MOSTLY IN THE 50S, EXCEPT SOME
LOWER 60S ALONG THE COAST AND IN MORE URBAN AREAS. LIGHT NORTH TO
EAST WIND.

WEDNESDAY...INSTABILITY SCT SHOWERS ANTICIPATED...AT LEAST THROUGH
EARLY AFTN. PWAT CONTINUES 1.2 INCHES SO SOME AREAS WILL RECEIVE
BENEFICIAL RAINFALL. SKIES WILL BE MAINLY CLOUDY THROUGH MIDDAY
BEFORE SOME SLOW THINNING OCCURS LATE-DAY. MAXIMUM TEMPERATURES
WERE A BLEND OF MET/MAV GUIDANCE WITH CONTINUITY, AND WE EXPECT
HIGHS MOSTLY IN THE LOW TO MID 70S.  LIGHT NORTHEAST WIND.

&&

.SHORT TERM /WEDNESDAY NIGHT/...
LOW CLOUDS AND PATCHY FOG RE-EXPAND ACROSS OUR AREA IN LIGHT WIND
FIELD ASSOCIATED WITH THE WEDGE OF HIGH PRESS TUCKED DOWN THE COAST
FROM EASTERN CANADA.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
OPERATIONAL MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE LARGE SCALE
FEATURES THROUGH THE WEEKEND. THE FIRST SUCH FEATURE BEING THE
DEPARTING UPPER LEVEL CUT-OFF LOW THAT SHOULD BE TO OUR IMMEDIATE
EAST. THEN WE HAVE THE POTENTIAL PHASING OF A STRONG NORTHERN AND
SOUTHERN STREAM SYSTEM TO OUR WEST THAT CARVES OUT A VERY LARGE AND
DEEP CLOSED LOW/TROUGH ACROSS THE UPPER MID-WEST BY LATE FRIDAY
NIGHT.

THURSDAY...RATHER DRY DAY EXCEPT FOR SOME LINGERING SHOWERS EARLY ON
ACROSS OUR EASTERN PORTIONS. THERE COULD STILL BE SOME MID-LEVEL
INSTABILITY TO WORK WITH AS THE MID-LEVEL COLD POOL SCRAPES BY BUT
NOT EXPECTING MUCH QPF WITH. MID AND UPPER LEVEL RIDGING BECOME MORE
PROMINENT ON THURSDAY WHICH SHOULD GIVE WAY TO LATE DAY SUNSHINE.
TEMPERATURES WILL BE IN THE LOW-70S; AT OR SLIGHTLY BELOW NORMAL.

FRIDAY...MODEL GUIDANCE MAY BE BREAKING DOWN THE RIDGING OVERHEAD A
BIT TOO FAST, ESPECIALLY GIVEN THE DOWNSTREAM UPPER LEVEL LOW IS
STILL LINGERING BY AND THE APPROACH OF A DEEPENING TROUGH UPSTREAM,
THE RIDGE SHOULD BUILD SLIGHTLY BEFORE BREAKING. ONSHORE FLOW AHEAD
OF THE NEXT TROUGH AND ATTENDANT SURFACE FRONT MAY ALLOW FOR
SCATTERED SHOWERS TO BREAK OUT ALONG THE HIGHER ELEVATION LOCATIONS
ACROSS OUR WESTERN ZONES BY LATER FRIDAY AFTERNOON. DO NOT SEE MUCH
IN THE WAY OF CONVECTION WITH THIS ACTIVITY GIVEN THE STABLE LOWER
ATMOSPHERE. WE SEE A INCREASE IN SHOWER COVERAGE AND POSSIBLY
INTENSITY BY LATE FRIDAY NIGHT AS A STRONGER COLD FRONT INCHES
CLOSER. DAYTIME TEMPERATURES SHOULD REMAIN MUCH THE SAME, LOW-70S
WITH INCREASING COLD COVER.

SATURDAY...TRANSITION DAY WITH A STRONG FRONT EXPECTED TO SWEEP
THROUGH DURING THE MORNING HOURS. DEEP SOUTHWEST FLOW AHEAD OF THE
FRONT WILL ALLOW PWATS TO CLIMB TO WELL ABOVE NORMAL MAKING FOR
HEAVIER RAINFALL. ANTECEDENT CONDITIONS ARE STILL PRETTY DRY ACROSS
THE REGION SO NOT EXPECTING ANYTHING OUT OF THE ORDINARY TO OCCUR
WITH THE POSSIBLE HEAVIER RAIN. LOTS OF CLOUD COVER AND COLD AIR
ADVECTION OCCURRING DROPPING TEMPERATURES BACK INTO THE MID TO
UPPER-60S.

SUNDAY - TUESDAY...CLOSED MID-LEVEL LOW ESTABLISHES ITSELF OVER
NORTHERN ONTARIO DURING THE SATURDAY THROUGH TUESDAY TIMEFRAME.
PREFERRED THE CMC AND UKMET EVOLUTION OF THE MID-LEVEL HEIGHT
FIELD OVER THE GFS AND ECMWF...BOTH OF WHICH HAVE A MORE
NEGATIVELY TILTED TROUGH AND PLACEMENT OF THE CLOSED LOW FURTHER
SOUTH AND EAST. THERE IS STILL QUITE A BIT UNCERTAINTY AS SHOWN BY
BOTH THE GEFS AND ECENS SPREAD IN MID-LEVEL HEIGHT FIELDS FROM THE
MEAN AND THIS THINKING IS SUPPORTED BY THE LATEST MODEL
VERIFICATIONS WHICH INDICATE A LESS AMPLIFIED SOLUTION.

EXPECT WINDS TO DECREASE SATURDAY NIGHT AS A RIDGE OF HIGH PRES
NOSES INTO THE REGION. IF THE BOUNDARY LAYER DECOUPLES ENOUGH W/
LIGHT WINDS...COULD SEE LOW TEMPS IN THE 35-40 RANGE IN THE
NORTHWEST INTERIOR OF OUR CWA. SUNDAY IS SHAPING UP TO BE THE
COOLEST DAY OF THE PERIOD...WITH 850 HPA TEMPS SUPPORTING HIGHS
SEVERAL DEGREES BELOW NORMAL...MID 50S IN THE POCONOS TO MID 60S
IN SOUTH JERSEY. A WEAK COLD FRONT IS PROGGED TO MOVE THROUGH
THE REGION EARLY ON TUESDAY...PRESENTING THE BEST CHANCE OF
PRECIPITATION DURING THIS TIMEFRAME. TEMPERATURES WILL RETURN
TO SEASONABLE LEVELS ON MONDAY AND CONTINUE THROUGH TUESDAY

&&

.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

OVERNIGHT THROUGH 12Z...VFR CONDITIONS WEST AND MVFR CIGS EAST
DEGRADING TO IFR CONDITIONS EAST AND POTENTIAL IFR CIGS WEST. SHOWERS
COASTAL NNJ AND SHOWERS VCNTY KRDG AND KMPO WITH CHANCE OF THUNDER
VCNTY KRDG.


WEDNESDAY...POSSIBLE MVFR/IFR CONDITIONS WILL LIKELY LAST THROUGH
THE MORNING, BEFORE BECOMING VFR AROUND MIDDAY TO EARLY AFTERNOON
FOR THE TAF SITES. AN ISOLATED TO SCATTERED SHOWER REMAINS
POSSIBLE THROUGH THE MORNING. NORTHEASTERLY WINDS ARE EXPECTED,
MOSTLY IN THE 8 TO 10 KNOT RANGE.

WEDNESDAY NIGHT...MVFR OR IFR CONDITIONS REDEVELOP IN LOW CLOUDS/PATCHY
FOG.

OUTLOOK...
THURSDAY...MVFR EARLY BECOMING VFR. EASTERLY WINDS EXPECTED.
POSSIBLE LINGERING SHOWER EARLY AT MIV/ACY, OTHERWISE DRY.

FRIDAY...MOSTLY VFR. RAIN, HEAVY AT TIMES LATE, OVERSPREADS THE AREA
FROM THE WEST. REDUCED VSBYS AND CIGS IN HEAVY SHOWERS. WINDS BACK
SOUTH-SOUTHWEST.

SATURDAY...MVFR/IFR EARLY IN HEAVY RAIN, TRENDING VFR. WINDS
CONTINUE TO BACK TO THE WEST-NORTHWEST.

&&

.MARINE...
TWO WEEKS AFTER RESTORATION OF A LENGTHY BUOY 44065 OUTAGE...DATA
TRANSMISSION TOPPED AT 4PM THIS PAST TUESDAY AFTERNOON. NDBC HAS
BEEN CONTACTED AND THEY WILL LET US KNOW WHAT THE PROBLEM IS.

IN THE MEANTIME...MARGINAL SCA CONDITIONS ARE FCST FOR THE NNJ
WATERS TODAY. WE DONT REALLY KNOW WHAT THE SEAS ARE DOING OFF THE
NNJ COAST.

NO EXPANSION OF THE SCA IS ANTICIPATED ATTM FOR THE REMAINDER OF
THE WATERS IN OUR 330 AM FCST.

BASICALLY NE FLOW CONTINUES THROUGH WEDNESDAY NIGHT WITH MAX GUSTS AROUND
20 KT. SEAS BUILD TO NEAR 5 FT NORTHERN WATERS...NEAR 4 FT SOUTHERN
WATERS AND GENERALLY 1-2 FT DELAWARE BAY.


OUTLOOK...
THURSDAY - FRIDAY...SCA CONDITIONS WILL LIKELY PERSIST ON OUR
WATERS THROUGH EARLY FRIDAY AS WE CONTINUE WITH THE EASTERLY ONSHORE
FLOW. SEAS WILL CONTINUE TO RUN AROUND 5 FEET. WINDS BEGIN TO BACK
TOWARDS THE SOUTH-SOUTHEAST BY FRIDAY AHEAD OF THE NEXT COLD FRONT.

SATURDAY...STRONG COLD FRONT MOVES THROUGH. WINDS BACK TOWARDS THE
WEST-NORTHWEST LATER IN THE DAY AND WITH STRONGER COLD AIR
ADVECTION OCCURRING, WE COULD SEE A RETURN TO SCA CONDITIONS.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM WEDNESDAY TO 6 AM EDT THURSDAY
     FOR ANZ450>452.

&&

$$
SYNOPSIS...HEAVENER/DRAG 1224A
NEAR TERM...DRAG/KLINE/ROBERTSON 1224A
SHORT TERM...DRAG/KLINE 1224A
LONG TERM...FRANCK/HEAVENER
AVIATION...DRAG/HEAVENER/KLINE/ROBERTSON 1224A
MARINE...DRAG/HEAVENER/KLINE 1224A





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