Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

Home | 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 290924
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
424 AM EST SAT NOV 29 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED ALONG THE MIDDLE ATLANTIC COAST EARLY THIS
MORNING WILL DRIFT TO THE EAST AND OUT TO SEA TODAY. A WARM FRONT
APPROACHING FROM THE SOUTHWEST IS FORECAST TO ARRIVE TONIGHT,
FOLLOWED BY A COLD FRONT FROM THE NORTHWEST ON MONDAY. HIGH
PRESSURE IS EXPECTED TO BUILD INTO OUR REGION FROM THE WEST FOR
TUESDAY WITH ANOTHER COLD FRONT ANTICIPATED TO ARRIVE LATE ON
WEDNESDAY. HIGH PRESSURE IS FORECAST TO BUILD ACROSS NEW YORK
STATE, NEW ENGLAND AND SOUTHEASTERN CANADA DURING THURSDAY AND
FRIDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE AT THE SURFACE IS OVER OUR AREA TO START THE DAY,
HOWEVER THIS WILL THEN SHIFT OFFSHORE. THE FLOW ALOFT IS MAINLY
TURNING ZONAL TODAY, ALTHOUGH SOME BACKING TO THE SOUTHWEST IS
FORECAST TO OCCUR BY LATE IN THE DAY.

AS THE FLOW BACKS AND LOW PRESSURE BEGINS TO ORGANIZE ACROSS THE
UPPER MIDWEST, A RETURN FLOW WILL BECOME BETTER ESTABLISHED
BETWEEN IT AND HIGH PRESSURE SHIFTING TO OUR EAST. THERE IS DECENT
WAA FORECAST TO DEVELOP THROUGH THE DAY, AND THIS WILL HELP
ORGANIZE A WARM FRONT TO OUR SOUTHWEST WHICH THEN LIFT
NORTHEASTWARD. THE PRESENCE OF THE WAA DEVELOPING /STRONGER ALOFT/
WILL HELP INCREASE THE ISENTROPIC LIFT. THIS MAY ASSIST IN
GENERATING SOME FLURRIES OR LIGHT SNOW. THE FORECAST SOUNDINGS
LOOK FAIRLY DRY BELOW THE CLOUD BEARING LEVEL, WHICH MAY RESULT IN
VIRGA/SNIRGA. THERE MAY BE ENOUGH MID LEVEL MOISTURE THOUGH IN
CONJUNCTION WITH THE ISENTROPIC LIFT TO PRODUCE SOME LIGHT SNOW
ACROSS PARTS OF THE AREA ESPECIALLY THROUGH MIDDAY. THE GREATEST
CHC /STILL LOW POPS THOUGH/ APPEAR TO BE MAINLY ACROSS PORTIONS OF
EASTERN PENNSYLVANIA TO NORTHWESTERN NEW JERSEY. THEREFORE WE WILL
CONTINUE TO CARRY SOME 20-30 POPS FOR A TIME. SOME SNOW IS BEING
REPORTED TO OUR WEST ACROSS CENTRAL PENNSYLVANIA AND EVEN ACROSS
PORTIONS OF WESTERN MARYLAND, HOWEVER EVEN THE HRRR KEEPS THIS
WEST OF OUR CWA. GIVEN THE LOW POPS, NO SNOW ACCUMULATIONS ARE
INCLUDED ALTHOUGH A LOCALIZED LIGHT COATING CANNOT BE RULED OUT.

OTHERWISE, WE SHOULD HAVE A DECENT AMOUNT OF MID TO HIGH LEVEL
CLOUDS AROUND THE AREA TODAY DUE TO THE WAA AND INCOMING WARM
FRONT. WE ARE ANTICIPATING TEMPERATURES TO BE A BIT HIGHER THAN
YESTERDAY, BUT SINCE MIXING MAY NOT BE ALL THAT EFFICIENT WE WENT
CLOSE TO A NAM/GFS MOS BLEND. THE LAMP/LAV GUIDANCE WAS USED EARLY
THIS MORNING TO HELP ASSIST IN TEMPERATURE TRENDS GIVEN SOME
VARIABILITY WITH RADIATIONAL COOLING LOCATIONS AND SOME CLOUD
COVER AT TIMES FOR OTHERS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
HIGH PRESSURE TO OUR EAST AND LOW PRESSURE TRACKING UP TOWARDS
HUDSON BAY IN CANADA WILL PROMOTE A CONTINUATION OF A RETURN FLOW.
THE PRESSURE GRADIENT WILL ALSO TIGHTEN BETWEEN THESE TWO SYSTEMS,
AND THE MODEL GUIDANCE INCREASES THE 925 MB WINDS TO AROUND 30
KNOTS OVERNIGHT. THIS WILL HELP ASSIST WITH THE CONTINUATION OF
WAA AS A SOUTH TO SOUTHWEST FLOW IS MAINTAINED. A WARM FRONT WILL
BE DRIVEN NORTH ACROSS OUR AREA AS A RESULT AND OVERALL THE LIFT
ASSOCIATED WITH IT AND THE WAA APPEAR TO BE WEAK. THE MOISTURE
WILL GRADUALLY INCREASE AND THEREFORE A FAIR AMOUNT OF CLOUDS
SHOULD BE AROUND ESPECIALLY IN ADVANCE OF THE WARM FRONT ITSELF.

THE FORECAST SOUNDINGS INDICATE A MOISTENING UP OF THE LOW
LEVELS. THIS IS BENEATH SOME DRIER AIR AND WITH LITTLE IN THE WAY
OF FORCING, PERHAPS SOME DRIZZLE COULD DEVELOP MAINLY ACROSS
NORTHEASTERN PENNSYLVANIA AND NORTHWESTERN NEW JERSEY. THE DEPTH
OF THE MOISTENING LAYER THOUGH MAY NOT BE CONDUCIVE ENOUGH SINCE
THE FLOW IS MORE SOUTHERLY AS OPPOSED TO ONSHORE. GIVEN SUCH A LOW
CHC AND OUR CONFIDENCE BEING LOW, WE DID NOT INCLUDE A MENTION IN
THE FORECAST ATTM. IF SOME DRIZZLE WERE TO OCCUR, IT IS WORTH
MENTIONING THAT SOME FREEZING DRIZZLE COULD OCCUR UP NORTH GIVEN
AIR TEMPERATURES FORECAST TO BE NEAR FREEZING DESPITE THE WAA.
THERE MAY NOT BE MUCH WIND AT THE SURFACE GIVEN AN INVERSION
DEVELOPING.

AS FOR LOW TEMPERATURES, WE GENERALLY SIDED WITH AN EVEN BLEND OF
THE NAM/GFS MOS. TEMPERATURES MAY ACTUALLY HOLD STEADY OR RISE A
LITTLE ESPECIALLY IF THE CLOUD COVER IS NEARLY SOLID.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
THE MID LEVEL PATTERN IS EXPECTED TO BE SOMEWHAT ZONAL ACROSS THE
NATION FOR MUCH OF THE NEW WEEK. AS A RESULT, WE ARE ANTICIPATING
QUICK MOVING WEATHER SYSTEMS AND TEMPERATURES SHOULD OSCILLATE
AROUND NORMAL.

A WARM FRONT IS EXPECTED TO LIFT TO OUR NORTH ON SUNDAY, LEAVING
OUR REGION IN A RELATIVELY MILD SOUTHWEST FLOW FOR SUNDAY INTO
SUNDAY NIGHT. CLOUDS ARE EXPECTED TO LINGER OVER OUR NORTHWESTERN
COUNTIES DURING THAT PERIOD.

A MID LEVEL SHORT WAVE TROUGH IS ANTICIPATED TO MOVE ACROSS
ONTARIO AND THE GREAT LAKES ON MONDAY BEFORE PASSING ACROSS
SOUTHERN QUEBEC AND THE NORTHEASTERN STATES ON MONDAY NIGHT. THE
SHORT WAVE IS FORECAST TO PUSH A COLD FRONT THROUGH OUR REGION ON
MONDAY AFTERNOON AND MONDAY EVENING. CLOUDS WILL ACCOMPANY THE
BOUNDARY AND THERE IS A LOW CHANCE OF LIGHT RAIN SHOWERS.

SURFACE HIGH PRESSURE IS EXPECTED TO MOVE FROM THE GREAT LAKES ON
MONDAY NIGHT TO THE SAINT LAWRENCE RIVER VALLEY ON TUESDAY. THE
HIGH WILL PUSH DRY AIR DOWN INTO OUR REGION. HOWEVER, CLOUDS AND
SOME LIGHT RAIN MAY LINGER, ESPECIALLY ACROSS OUR FAR SOUTHERN
COUNTIES.

AS THE HIGH MOVES FARTHER TO THE EAST, THE SURFACE FLOW IN OUR
REGION IS FORECAST TO VEER FROM THE EAST TO THE SOUTH ON TUESDAY
NIGHT. THE FLOW OFF THE OCEAN SHOULD RESULT IN AN INCREASE IN
MOISTURE ALONG WITH LOWERING CLOUDS AND AN INCREASING CHANCE OF
PRECIPITATION INTO WEDNESDAY.

ANOTHER COLD FRONT FROM THE NORTHWEST IS ANTICIPATED TO ARRIVE
LATE ON WEDNESDAY. DRY AIR IS EXPECTED TO FOLLOW FOR THURSDAY.
STRONG HIGH PRESSURE IS FORECAST TO FOLLOW A SIMILAR TRACK TO THE
EARLY WEEK AREA OF HIGH PRESSURE. AS THE CENTER OF THE HIGH MOVES
FROM THE SAINT LAWRENCE RIVER VALLEY TO THE MARITIME PROVINCES ON
FRIDAY, THE SURFACE FLOW IN OUR REGION SHOULD AGAIN VEER FROM THE
EAST TO THE SOUTH RESULTING IN A MOIST ONSHORE FLOW. THERE COULD
BE CLOUDS AND SOME LIGHT RAIN ON FRIDAY.

&&

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

TODAY...VFR WITH CEILINGS AT OR ABOVE 5000 FEET. SOME FLURRIES OR
A LITTLE LIGHT SNOW IS POSSIBLE ESPECIALLY NORTH AND WEST OF KPHL.
IF THIS WERE TO REACH THE GROUND, THE LOCAL VISIBILITY MAY BRIEFLY
LOWER TO MVFR. THE CHANCE THOUGH IS TO LOW AT THIS TIME TO INCLUDE
IN THE TAFS. A LIGHT AND VARIABLE OR CALM WIND, BECOMING SOUTHERLY
UP TO 10 KNOTS DURING THE COURSE OF THE DAY.

TONIGHT...VFR OVERALL, WITH CEILINGS MAINLY IN THE 5000 TO 15000
FEET RANGE. SOUTH-SOUTHWEST WINDS LESS THAN 10 KNOTS.

OUTLOOK...
SUNDAY THROUGH TUESDAY...MAINLY VFR.

TUESDAY NIGHT AND WEDNESDAY...MVFR AND IFR CONDITIONS ARE
POSSIBLE ALONG WITH A CHANCE OF LIGHT RAIN. SOME LIGHT SNOW MAY
FALL ON TUESDAY NIGHT, ESPECIALLY AROUND KRDG AND KABE.

&&

.MARINE...
HIGH PRESSURE WILL SHIFT TO OUR EAST TODAY ALLOWING FOR A
SOUTHERLY FLOW TO DEVELOP. A WARM FRONT WILL ARRIVE TONIGHT, AND A
WAA PATTERN WILL OCCUR TODAY THROUGH TONIGHT. AS THE WAA
STRENGTHENS, A LOW-LEVEL JET /925 MB/ ON THE ORDER OF 30-35 KNOTS
IS FORECAST TO MOVE ACROSS THE AREA LATER TONIGHT. THE FORECAST
SOUNDINGS DO SHOW THE POTENTIAL FOR GUSTS TO AROUND 25 KNOTS TO
OCCUR FOR A TIME TONIGHT. WHILE WE WILL BE WITHIN A WAA PATTERN,
IT APPEARS THAT SMALL CRAFT ADVISORY CRITERIA WILL BE MET ON THE
OCEAN ZONES. IN ADDITION, THE INCREASING SOUTHERLY FLOW WILL BUILD
THE SEAS THROUGH TONIGHT. AFTER COLLABORATION WITH WFO`S OKX AND
AKQ, WE ISSUED A SMALL CRAFT ADVISORY STARTING AT 23Z TONIGHT FOR
JUST THE OCEAN ZONES.

OUTLOOK...
SUNDAY...A SMALL CRAFT ADVISORY IS IN EFFECT ON OUR OCEAN WATERS
FOR A SOUTHWEST WIND GUSTING TO 25 OR 30 KNOTS AND WAVE HEIGHTS
BUILDING NEAR 5 FEET. WIND SPEEDS SHOULD BE SLIGHTLY LOWER ON
DELAWARE BAY AND NO ADVISORY IS IN EFFECT THERE.

SUNDAY NIGHT...WINDS AND SEAS ARE FORECAST TO DECREASE SLOWLY.
HOWEVER, THE SMALL CRAFT ADVISORY MAY EVENTUALLY NEED TO BE
EXTENDED.

MONDAY THROUGH TUESDAY...ANOTHER SMALL CRAFT ADVISORY MAY BE
NEEDED AS A COLD FRONT PUSHES THROUGH OUR REGION.

TUESDAY NIGHT AND WEDNESDAY...NO MARINE HEADLINES ARE
ANTICIPATED.

&&

.EQUIPMENT...
THE WSR-88D LOCATED AT FORT DIX, NEW JERSEY (KDIX) REMAINS OUT OF
SERVICE. WE ARE WAITING ON REPLACEMENT PARTS AND WE HOPE TO HAVE
THE RADAR REPAIRED BY THE END OF THE DAY.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EST SUNDAY
     FOR ANZ450>455.

&&

$$

SYNOPSIS...IOVINO
NEAR TERM...GORSE
SHORT TERM...GORSE
LONG TERM...IOVINO
AVIATION...GORSE/IOVINO
MARINE...GORSE/IOVINO
EQUIPMENT...IOVINO








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