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 180914
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
414 AM EST TUE NOV 18 2014

.SYNOPSIS...
ARCTIC HIGH PRESSURE WILL BUILD TOWARD THE MID-ATLANTIC REGION TODAY
AND WEDNESDAY. A COLD FRONT WILL MOVE THROUGH THE AREA THURSDAY
AFTERNOON. HIGH PRESSURE RETURNS TO THE AREA LATE IN THE WEEK. THE
HIGH MOVES OFFSHORE THIS WEEKEND. A WARM FRONT IS EXPECTED TO MOVE
THROUGH THE AREA BY THE END OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ARCTIC HIGH PRES WILL BUILD OVER THE SOUTHERN STATES TODAY AS THE
LOW PRES FROM YDY MOVES OVER THE CAN MARITIMES AND INTENSIFIES.  THE
PGRAD BETWEEN THESE TWO SYSTEMS WILL MAKE FOR A GUSTY W WIND TODAY.
WITH A TROF OVER THE E AND STRONG CAA, TEMPS WILL BASICALLY CONTINUE
TO FALL DURG THE DAY WITH THE AFTN "HIGH" GENLY IN THE LWR 30S.
HOWEVER, WITH THE GUSTY WIND IT WILL FEEL MUCH COLDER.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
THE HIGH BUILDS NEWD TONIGHT AND THE SKY WILL CLEAR. THERE WILL
BE SOME WIND WHICH WILL PREVENT IDEAL RADIATIONAL COOLING.
HOWEVER, TEMPS WILL PLUMMET TO NEAR RECORD COLD VALUES IN MANY
AREAS LOWS WED MRNG WILL BE IN THE TEENS TO AROUND 20. SEE CLIMATE
SECTION FOR MORE DETAILS CONCERNING TONIGHT`S LOWS.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
THE CORE OF THE ARCTIC AIRMASS WILL REMAIN OVER THE MID-ATLANTIC AND
NORTHEAST STATES WEDNESDAY MORNING. THE ARCTIC HIGH SHIFTS TOWARD
THE SOUTHEAST COAST IN THE AFTERNOON. THE AIRMASS OVERHEAD BEGINS
TO MODERATE ALOFT (H8 TEMPS AROUND -15C AT 12Z WEDNESDAY INCREASE
TO BETWEEN -3C AND -6C BY 00Z THURSDAY) AS SOUTHWESTERLY FLOW
DEVELOPS IN THE AFTERNOON. SINCE THE ENSUING LOW-LEVEL WAA PATTERN
IS EXPECTED TO OCCUR AFTER PEAK HEATING, MAX TEMPS WILL STILL BE
20-25F BELOW NORMAL ON WEDNESDAY, RANGING FROM THE MID 20S IN
THE POCONOS TO MID 30S IN THE DELMARVA. THE PRESSURE GRADIENT AND
ASSOCIATED WIND FIELD WILL BE WEAKER COMPARED TO TODAY, BUT STILL
AROUND 10-15 MPH. THE COMBINATION OF THE WIND AND THE COLD WILL
PRODUCE WIND CHILLS IN THE TEENS ACROSS THE HIGHER ELEVATIONS AND
20S ELSEWHERE.

AN AREA OF LOW PRESSURE WILL DEVELOP OVER THE GREAT LAKES WEDNESDAY
NIGHT BEFORE LIFTING NORTHEASTWARD INTO EASTERN CANADA THURSDAY. THE
COLD FRONT WITH THIS SYSTEM WILL APPROACH FROM THE MIDWEST THROUGH
THURSDAY MORNING. SOUTHWEST FLOW IN THE PRE-FRONTAL (RELATIVELY)
WARM SECTOR WILL ALLOW THE AIRMASS TO MODERATE A BIT OVER THE MID-
ATLANTIC REGION BEFORE THE COLD FRONT PASSES THRU LATE IN THE DAY
ON THURSDAY. MAX TEMPS THURSDAY REBOUND INTO THE 40S, EXCEPT 30S
IN THE MOUNTAINS OF NE PA AND NW NJ. NO PRECIP IS FORECAST AS
MODELS CONTINUE TO SHOW VERY LIMITED MOISTURE WITH THIS FRONT
WHILE THE BEST DYNAMICS WILL STAY NORTH OF THE REGION.

A REINFORCING SHOT OF COLD AIR WILL ARRIVE THURSDAY NIGHT AND FRIDAY
BEHIND THE AFOREMENTIONED COLD FRONT. MAX TEMPS FRIDAY RANGE FROM
NEAR 30F IN THE MOUNTAINS TO NEAR 40F IN THE DELMARVA AND ALONG THE
NJ COAST. A W-NW AROUND 15 MPH WILL PRODUCE WIND CHILLS ABOUT 10F
LOWER THAN THE DRY BULB TEMPS. ADDED FLURRIES INTO THE FORECAST
FOR THE POCONOS WITH THE POTENTIAL FOR A FEW LAKE EFFECT
STREAMERS, BUT A MORE ZONAL FLOW SHOULD CONFINE ACCUMULATING
SNOWFALL TO NORTH OF THE CWA.

A WARMING TREND IS IN STORE FOR THE WEEKEND INTO EARLY NEXT WEEK.
SHORTWAVE RIDGING ALOFT WILL DEVELOP OVER THE EASTERN CONUS ON
SATURDAY. THE UPPER RIDGE AND SURFACE HIGH WILL SHIFT OFFSHORE
SATURDAY NIGHT AND SUNDAY. TEMPS STILL ABOUT 10-15F BELOW NORMAL ON
SATURDAY BUT A STRENGTHENING SOUTHWESTERLY RETURN FLOW WILL ADVECT A
SIGNIFICANTLY WARMER AND MORE MOIST AIRMASS INTO THE REGION LATER IN
THE WEEKEND. FORECAST HIGHS FOR SUNDAY ARE NEAR NORMAL. THESE
FORECAST HIGHS WERE ALSO ON THE CONSERVATIVE SIDE COMPARED TO WPC
GUIDANCE SINCE THE COLD AIR RETREATING TO OUR NORTH MAY SLOW DOWN
THE PROGRESSION OF THE WARM FRONT MORE THAN MODELS INDICATE. MAX
TEMPS MONDAY MAY BE IN THE 60S ACROSS MUCH OF THE AREA. ISENTROPIC
LIFT AND MOISTURE FLUX ALONG AND AHEAD OF THE WARM FRONT WILL
LIKELY YIELD A PERIOD OF PRECIPITATION SOMETIME SUNDAY AFTERNOON
AND SUNDAY NIGHT. THERMAL PROFILES ONLY SUPPORT ONE PTYPE: RAIN,
EVEN IN THE COOLER POCONOS.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

AFTER A BAD MON, TODAY LOOKS MUCH BETTER. HIGH PRES WILL BUILD
OVER THE SRN STATES AND DRY WX IS AND VFR CONDS ARE EXPECTED THRU
THE TAF PD.

THE PGRAD BETWEEN THIS HIGH AND THE LOW FROM YDY, WHICH WILL BE MOVG
INTO ERN CANADA WILL MAKE FOR A GUSTY W WIND. WIND GUSTS CUD
REACH 30 KTS IN SOME AREAS THIS AFTN, BEFORE DECREASING SOMEWHAT
AFTER SUNSET.

OUTLOOK...
WEDNESDAY AND WEDNESDAY NIGHT...VFR WITH A LIGHT SW WIND DEVELOPING.

THURSDAY AND THURSDAY NIGHT...VFR. SW WINDS INCREASE TO 10-15 KT
AHEAD OF A COLD FRONT, BECOMING WESTERLY IN THE AFTERNOON ONCE THE
FRONT MOVES THRU. A FEW GUSTS 25-30 KT ARE POSSIBLE LATE THURSDAY
AND THURSDAY NIGHT BEHIND THE FRONT.

FRIDAY AND SATURDAY...VFR AND LIGHT WINDS.

&&

.MARINE...
THE GALE WARNING REMAINS IN EFFECT THRU WED MORNING.  GOOD CAA
BEHIND THE CFP AND A STRONG PGRAD BETWEEN HIGH PRES TO THE S AND THE
LOW FROM YDY OVER SERN CAN WILL KEEP A STRONG W WIND OVER THE AREA
WATERS.

OUTLOOK...
WEDNESDAY...WINDS DIMINISH WEDNESDAY MORNING. MAY SEE A PERIOD OF 25
KT WINDS AND 4-5 FT SEAS EARLY IN THE DAY IN THE COASTAL ATLANTIC
WATERS BEFORE WINDS DECREASE TO BELOW SCA CRITERIA.

WEDNESDAY NIGHT AND THURSDAY MORNING...SCA LIKELY IN STRENGTHENING
SW FLOW AHEAD OF A COLD FRONT.

THURSDAY AFTERNOON THROUGH FRIDAY...SCA LIKELY WITH POST-FRONTAL
W-NW WINDS GENERALLY 25-30 KT. HOWEVER, A PERIOD OF GALES CANNOT BE
RULED OUT THURSDAY NIGHT IMMEDIATELY BEHIND THE FRONT.

FRIDAY NIGHT AND SATURDAY...SUB-SCA WINDS.

&&

.CLIMATE...
BELOW IS A LISTING OF RECORD LOW TEMPERATURES AND THE YEAR OF
OCCURRENCE FOR NOVEMBER 19 FOR OUR EIGHT CLIMATE SITES. WE HAVE ALSO
INCLUDED OUR FORECAST NEAR-RECORD LOW TEMPERATURES FOR TONIGHT AS
AN UNUSUALLY COLD AIRMASS FOR THIS EARLY IN THE SEASON ARRIVES.

11/19 RECORD LOWS:        11/19 FORECAST LOWS:

ACY 18  1936              ACY  17
PHL 20  1936              PHL  21
ILG 15  1936              ILG  19
ABE 11  1924              ABE  17
TTN 17  1936              TTN  19
GED 20  1959              GED  18
RDG 18  1936              RDG  17
MPO 10  1933              MPO  10

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...GALE WARNING UNTIL 6 AM EST WEDNESDAY FOR ANZ430-431-450>455.

&&

$$
SYNOPSIS...KLEIN
NEAR TERM...NIERENBERG
SHORT TERM...NIERENBERG
LONG TERM...KLEIN
AVIATION...KLEIN/NIERENBERG
MARINE...KLEIN/NIERENBERG
CLIMATE...KLINE/KLEIN






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