Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 211236
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
836 AM EDT MON APR 21 2014

.SYNOPSIS...
HIGH PRESSURE WELL EAST OF NEW ENGLAND WILL GRADUALLY LOSE ITS
INFLUENCE ON OUR WEATHER TODAY AND TONIGHT. A COLD FRONT ASSOCIATED
WITH LOW PRESSURE MOVING EAST FROM THE GREAT LAKES REGION WILL CROSS
THE AREA TUESDAY EVENING. HIGH PRESSURE SHOULD THEN BUILD IN FOR THE
MIDDLE PART OF THE WEEK. ANOTHER LOW AND ASSOCIATED FRONTAL
BOUNDARIES WILL AFFECT OUR AREA FRIDAY INTO SUNDAY, FOLLOWED BY MORE
HIGH PRESSURE LATE SUNDAY INTO MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE THIS MORNING INCLUDED CANCELLING THE FROST ADVISORY AS
TEMPERATURES CONTINUE TO RISE RATHER QUICKLY. WE USED THE LAV/LAMP
GUIDANCE TO TWEAK TEMPS/DEWPOINTS TO REFLECT CURRENT TRENDS AND
OBSERVATIONS, BUT OTHERWISE MAX TEMPS LOOK ON TARGET AT THIS TIME.
12Z KIAD REGIONAL SOUNDING SHOWS AMPLE DRY AIR THROUGH THE COLUMN
AND CONVECTIVE TEMPS OUT OF REACH. SO, OTHER THAN SOME CIRRUS
OVERHEAD AT TIMES, LOTS OF SUNSHINE IS EXPECTED THROUGH THE DAY.

A RIDGE OF HIGH PRESSURE ACROSS THE AREA THIS MORNING WILL WEAKEN
AND MOVE OFF TO THE EAST. IT WILL ENSURE A PLEASANT WEATHER DAY
ACROSS THE AREA WITH PLENTY OF SUNSHINE AND SEASONABLY MILD
TEMPERATURES. THERE WILL BE SOME CI/CS CLOUDS AT TIMES. A MAV/MET
BLEND WAS USED FOR TEMPS TODAY...WITH HIGHS EXPECTED TO REACH THE
MID/UPPER 60S IN MOST SPOTS. IT WILL BE A BIT COOLER ALONG THE
SHORE WITH A LIGHT ONSHORE BREEZE. WINDS WILL BE LIGHTER
TODAY...COMPARED TO YESTERDAY, AND WINDS WILL TEND TO SWITCH TO
SRLY/SWRLY LATER TODAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
FAIR WEATHER WILL EXTEND INTO THE OVERNIGHT PERIOD. SKY COVER WILL
BE MOSTLY CLR THIS EVENING AND THEN CLOUDS WILL INCREASE OVERNIGHT.
LOW TEMPERATURES WILL BE MILDER MON NGT WITH LOWS ONLY EXPECTED TO
DROP INTO THE LOW/MID 40S IN MOST AREAS. WINDS WILL BE LIGHT SRLY.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
A MID LEVEL TROUGH WILL APPROACH FROM THE WEST ON TUESDAY AND ITS
AXIS IS EXPECTED TO PASS THROUGH EARLY ON WEDNESDAY. A SURFACE COLD
FRONT ASSOCIATED WITH THIS FEATURE IS FORECAST TO ARRIVE LATE ON
TUESDAY AND IT WILL LIKELY BRING RAIN SHOWERS FOR THE AFTERNOON AND
EVENING HOURS. THE FRONT WILL BE PROGRESSIVE AND MOISTURE SHOULD BE
SOMEWHAT LIMITED. AS A RESULT, RAINFALL TOTAL ARE EXPECTED TO BE
GENERALLY LESS THAN A QUARTER INCH. SOME MARGINAL INSTABILITY IS
ANTICIPATED WITH THIS FRONT, AND SPC HAS PLACED THE ENTIRE REGION
UNDER A GENERAL THREAT OF TSTMS. THE WEATHER GRIDS FOR TUESDAY
AFTERNOON WERE ADJUSTED TO INCLUDE A SLIGHT CHANCE OF THUNDER TO
ACCOUNT FOR THE POSSIBILITY OF A RUMBLE OR TWO OF THUNDER.

A PUSH OF COLD ADVECTION IS EXPECTED FOR TUESDAY NIGHT INTO
WEDNESDAY. TEMPERATURES AT 850 HPA ARE FORECAST TO DROP A BIT
BELOW ZERO CELSIUS FOR WEDNESDAY. AS A RESULT, MAXIMUM
TEMPERATURES SHOULD NOT GET MUCH ABOVE THE LOWER 60S IN MUCH OF
OUR REGION WITH HIGHS REMAINING IN THE 50S IN THE ELEVATED
TERRAIN. THE COLD ADVECTION SHOULD RESULT IN THE DEVELOPMENT OF
SOME STRATOCUMULUS. THERE MAY BE A FEW SHOWERS OR SPRINKLES IN OUR
NORTHERN AND CENTRAL COUNTIES, MAINLY THROUGH ABOUT MIDDAY ON
WEDNESDAY AS A SECONDARY SURFACE TROUGH DROPS THROUGH OUR REGION.

THE MID LEVEL PATTERN IS EXPECTED TO REMAIN PROGRESSIVE WITH A RIDGE
AXIS PASSING OVERHEAD ON THURSDAY NIGHT. SURFACE HIGH PRESSURE FROM
THE WEST IS ANTICIPATED TO MOVE ACROSS OUR REGION BRINGING DRY
WEATHER AND SEASONABLE TEMPERATURES FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT.

SURFACE LOW PRESSURE IS FORECAST TO PASS ACROSS THE GREAT LAKES
ON FRIDAY AND INTO NEW ENGLAND ON SATURDAY. IT SHOULD PULL A WARM
FRONT THROUGH OUR REGION ON FRIDAY FOLLOWED BY A COUPLE OF SURFACE
TROUGHS FROM THE WEST AND NORTHWEST ON FRIDAY NIGHT AND SATURDAY. WE
WILL CONTINUE TO CARRY A CHANCE OF SHOWERS FOR FRIDAY INTO SATURDAY.

SURFACE HIGH PRESSURE IS EXPECTED TO NOSE INTO OUR REGION FROM THE
NORTHWEST FOR SUNDAY.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

PLEASANT WEATHER EXPECTED AT THE TERMINALS TODAY. VFR CONDITIONS
WITH ONLY SOME CI/CS CLOUDS AT TIMES. WINDS WILL BE LIGHT TODAY FROM
THE E/SE THIS MORNING THEN S/SW THIS AFTERNOON. THERE WILL BE
INCREASING CLOUDS TONIGHT...BUT VFR CONDITIONS WILL CONTINUE.

SOME GUIDANCE SHOWED THE POTENTIAL FOR A WINDOW OF POSSIBLE MVFR
VSBY RESTRICTIONS LEADING UP TO DAYBREAK TUESDAY AT THE SOUTHEAST
TAF SITES, NAMELY KACY AND KMIV, AND A TEMPO GROUP WAS INCLUDED
WITH THE 12Z TAFS.

OUTLOOK...

TUESDAY AND TUESDAY NIGHT...MAINLY VFR WITH A CHANCE OF AFTERNOON
AND EVENING SHOWERS.

WEDNESDAY THROUGH THURSDAY NIGHT...MAINLY VFR.

FRIDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.

&&

.MARINE...
THERE IS STILL SOME PRESSURE GRADIENT ACROSS THE WATERS. WE WILL
CONTINUE WITH THE SCA FLAG TODAY FOR SOME LINGERING GUSTS TO AROUND
25 KTS AND ENHANCED 4-6 FT SEAS. THE SCA FLAG WILL PROBABLY BE TAKEN
DOWN LATER TODAY AND A SUB-SCA PERIOD IS EXPECTED AT LEAST INTO THE
OVERNIGHT HOURS. FAIR WEATHER EXPECTED ON THE WATERS TODAY AND
TONIGHT.

OUTLOOK...

TUESDAY...NO MARINE HEADLINES ARE ANTICIPATED.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...NORTHWESTERLY WIND GUSTS
OF 25 TO 30 KNOTS ARE POSSIBLE.

THURSDAY THROUGH SATURDAY...NO MARINE HEADLINES ARE
ANTICIPATED.

&&

.FIRE WEATHER...
RELATIVE HUMIDITY VALUES NEAR OR BELOW 30 PERCENT ON WEDNESDAY
AFTERNOON ALONG WITH A GUSTY NORTHWEST WIND AT 15 TO 20 MPH MAY
RESULT IN AN ENHANCED THREAT OF WILDFIRE SPREAD AT THAT TIME.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ451>455.

&&

$$
SYNOPSIS...MIKETTA
NEAR TERM...KLINE/O`HARA
SHORT TERM...O`HARA
LONG TERM...MIKETTA
AVIATION...KLINE/MIKETTA/O`HARA
MARINE...MIKETTA/O`HARA
FIRE WEATHER...IOVINO






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