Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 271315
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
915 AM EDT MON OCT 27 2014

.SYNOPSIS...
HIGH PRESSURE WILL SETTLE OVERHEAD TODAY BEFORE MOVING OFFSHORE
TONIGHT. A WARM FRONT IS WILL PASS THROUGH THE AREA TUESDAY FOLLOWED
BY THE PASSAGE OF A COLD FRONT ON WEDNESDAY. HIGH PRESSURE BRIEFLY
RETURNS THURSDAY AND THE FIRST PART OF FRIDAY. A COLD FRONT IS
EXPECTED TO MOVE THROUGH FRIDAY NIGHT. CANADIAN HIGH PRESSURE BUILDS
INTO THE EASTERN UNITED STATES FOR THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE RIDGING WILL CONTINUE TO EXPAND TOWARDS THE EAST TODAY
ENCOMPASSING OUR ENTIRE REGION. LOTS OF SUBSIDENCE WILL OCCUR WHICH
WILL KEEP OUR SKIES CLEAR AND DRY WEATHER PREVAILS. THIS WILL LIMIT
THE AMOUNT OF VERTICAL MIXING EXPECTED AS THE SUBSIDENCE INVERSION
KEEPS A TIGHT LID ON THINGS. COMPARED TO THE PAST COUPLE OF DAYS WE
MAY MIX JUST SHY OF 925MB AND THERE IS NOT TOO MUCH MOMENTUM ALOFT
TO MIX DOWN. HIGHS TODAY COULD END UP BEING JUST AS WARM AS SUNDAY,
IF WE EXPERIENCE OUR FULL MIXING POTENTIAL. FULL SUNSHINE AND A
LIGHT WESTERLY FLOW, ADDING IN FOR DOWNSLOPING, COULD PUSH US A BIT
HIGHER THAN GUIDANCE IS SUGGESTING SO THIS IS HOW WE TRENDED THE
FORECAST. WENT A DEGREE OR TWO ABOVE THE WARMER MAV...MET LOOKED WAY
TOO COLD EVERYWHERE TO BE CONSIDERED.

VERY MINOR CHANGES TO CURRENT PKG. VIRTUALLY NO CLOUDS ATTM. MADE
A FEW TWEAKS TO TEMPS WHERE NEEDED. A VERY NICE DAY IS IN STORE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
RIDGING WILL SLOWLY SLIDE THROUGH TONIGHT ALLOWING FOR FULL
DECOUPLING AND GOOD RADIATIONAL COOLING CONDITIONS. CLEAR SKIES AND
LIGHT WINDS WILL PREVAIL AS TEMPERATURES DROP QUICKLY AFTER SUNSET.
EXPECTING OVERNIGHT LOWS IN THE LOW-40S IN A LOT OF PLACES, WITH MID
TO UPPER-30S PROBABLE IN THE PINE BARRENS.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
ON TUESDAY, THE EASTERN SEABOARD WILL BE ENCOMPASSED IN DEEP S-SWLY
FLOW BETWEEN HIGH PRESSURE THAT IS PARKED OFF THE SOUTHEAST COAST
AND A COLD FRONT THIS IS APPROACHING FROM THE MIDWEST AND LOWER
MISSISSIPPI VALLEY. FORECAST 925 MB TEMPS AROUND 20C AND 850 MB
TEMPS AROUND 17C ARE BETWEEN +2 AND +3 SD FOR LATE OCTOBER. REMAINED
CONTINUITY AND WAS CLOSE TO THE PREVIOUS FORECASTS FOR MAX TEMPS.
FORECAST HIGHS IN THE MID TO UPPER 70S ARE SEVERAL DEGREES WARMER
THAN MOS GUIDANCE (WHICH HAS EXHIBITED A RECENT COOL BIAS) BUT
SLIGHTLY COOLER THAN PREDICTED VALUES THAT USE FULL MIXING FROM THE
925 MB OR 850 MB LAYER GIVEN HOW LOW THE SUN ANGLE. MAX TEMPS AROUND
80F ARE POSSIBLE, ESPECIALLY IN THE DELMARVA. GED WAS THE ONLY
CLIMATE SITE TO RECORD AN 80-DEGREE DAY SO FAR THIS MONTH.

THE COLD FRONT IS EXPECTED CROSS THE APPALACHIANS TUESDAY EVENING
AND REACH OUR EASTERN PA ZONES BY SUNRISE WEDNESDAY. THE FRONT MAY
SLOW DOWN A BIT WEDNESDAY AFTERNOON/EVENING AS IT ADVANCES TOWARD
THE COAST AND A WEAK WAVE OF LOW PRESSURE DEVELOPS ALONG THE
BOUNDARY. MODELS ARE IN GOOD AGREEMENT WITH THE TIMING OF FROPA,
WHICH ADDS CONFIDENCE TO THE FORECAST. WILL CONTINUE TO MENTION
SCATTERED SHOWERS WITH THE FROPA LATE TUESDAY NIGHT/WEDNESDAY
MORNING IN THE WESTERN ZONES AND WEDNESDAY INTO WEDNESDAY EVENING
CLOSER TO THE COAST.

HIGH PRESSURE BUILDS IN FROM THE MIDWEST LATE WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT. COOLER AIR RETURNS TO THE REGION BUT TEMPS
ARE STILL NEAR NORMAL.

THE LARGE-SCALE TROUGH STARTS TO AMPLIFY FRIDAY OVER THE EASTERN
CONUS AS STRONG SHORTWAVE DISTURBANCE IN THE POLAR JET STREAM DIGS
EQUATOR-WARD INTO THE GREAT LAKES. THERE WILL ALSO BE PAC NW ENERGY
MOVING INTO THE SOUTHEAST U.S. AS THIS SOUTHERN STREAM SHORTWAVE
ROTATES AROUND THE BASE OF THE MAIN TROUGH. MODELS ARE IN GENERAL
AGREEMENT WITH THESE TWO SYSTEMS NOT PHASING. SECONDARY CYCLOGENESIS
IS EXPECTED TO OCCUR OFF THE NEW ENGLAND COAST AS THE NORTHERN
STREAM SYSTEM APPROACHES THE NORTHEAST FRIDAY NIGHT AND SATURDAY. WE
MAY SEE A FEW SHOWERS ACROSS THE NORTH FRIDAY NIGHT WITH THE COLD
FRONT PASSAGE BUT THE COASTAL LOW WILL NOT DIRECTLY IMPACT OUR
REGION. THERMAL PROFILES LOOK TO BE COLD ENOUGH FOR RAIN TO MIX WITH
OR EVEN CHANGE TO SNOW/FLURRIES OVER THE POCONOS BY SATURDAY MORNING.

THE REMAINDER OF THE WEEKEND IS LOOKING DRY. THE MAIN WX STORY NEXT
WEEKEND WILL BE CHILLY TEMPS AND STRONG WINDS AS THE COLDEST
AIRMASS OF THE SEASON ARRIVES. MAX TEMPS ON SAT WILL LIKELY ONLY
BE IN THE 40S AND POSSIBLY EVEN THE 30S IN THE POCONOS. THE 00Z
GFS INDICATES NEAR WIND ADVISORY LEVEL GUSTS ON SATURDAY, BUT
CONFIDENCE IN THIS HAPPENING BASED ON ONE MODEL RUN THIS FAR OUT
IS TOO LOW TO MENTION IN HWO ATTM. SUNDAY DOES NOT LOOK MUCH WARMER.
THERE IS ALSO A POTENTIAL FOR A WIDESPREAD FREEZE ACROSS THE
ENTIRE AREA SATURDAY AND SUNDAY NIGHTS, INCLUDING THE PHILLY METRO
AND DELMARVA, WHERE A FREEZE HAS YET TO OCCUR THIS FALL. HOWEVER,
WE DO NOT ISSUE FROST/FREEZE PRODUCTS AFTER HALLOWEEN UNLESS THERE
IS AN ANOMALOUSLY WARM FALL THAT EXTENDS THE END OF THE GROWING
SEASON (WHICH WAS NOT THE CASE THIS YEAR).

&&

.AVIATION /13Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

TODAY - TONIGHT...VFR. LIGHT WESTERLY WINDS THIS MORNING WILL
INCREASE TOWARDS 10 KNOTS THIS AFTERNOON AND THEN VEER TOWARDS THE
SOUTH-SOUTHWEST LATE. SURFACE RIDGING SHOULD ALLOW FOR LIGHT AND
VARIABLE/CALM WINDS TONIGHT. HIGH CONFIDENCE.

OUTLOOK...

TUESDAY AND TUESDAY EVENING...VFR. SW WINDS 5-10 KT WITH SLIGHTLY
HIGHER GUSTS.

TUESDAY OVERNIGHT THROUGH WEDNESDAY EVENING...SCT SHRA MOVE INTO
WESTERN TERMINALS LATE TUESDAY NIGHT. SCT SHRA ON WEDNESDAY.
TEMPORARY FLIGHT RESTRICTIONS (MAINLY MVFR) IN SHRA.

WEDNESDAY OVERNIGHT THROUGH FRIDAY MORNING...VFR.

FRIDAY AFTERNOON...VFR. HOWEVER, IF FROPA OCCURS FASTER, SHRA AND
MVFR POSSIBLE.

&&

.MARINE...
TODAY - TONIGHT...SUB-SCA CONDITIONS EXPECTED. WESTERLY WINDS AROUND
15 KNOTS WITH SOME GUSTINESS CLOSE TO 20 KNOTS CAN BE EXPECTED THIS
AFTERNOON. SEAS 2 TO 4 FEET, SUBSIDING THROUGHOUT THE DAY. WINDS
DECREASE TONIGHT AS HIGH PRESSURE PASSES OVERHEAD. WINDS VEER
TOWARDS THE SOUTH EARLY TUESDAY MORNING. HIGH CONFIDENCE.

OUTLOOK...

TUESDAY AND WEDNESDAY...SW FLOW STRENGTHENS TUESDAY. WINDS AND SEAS
INCREASE TO NEAR SCA CRITERIA TUESDAY NIGHT AND WEDNESDAY MORNING.

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...WINDS AND WAVES BELOW SCA
CRITERIA.

FRIDAY AND FRIDAY NIGHT...SUB SMALL CRAFT ADVISORY CONDITIONS
EXPECTED ON FRIDAY. COLD FRONT MOVES THRU LATE. A STRONG NORTHWEST
FLOW BEHIND WILL LIKELY PRODUCE SCA WINDS FRIDAY NIGHT.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

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







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