Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 271946
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
346 PM EDT MON JUL 27 2015

.SYNOPSIS...
A NEARLY STALLED FRONTAL BOUNDARY WILL CONTINUE TO DISSIPATE IN
OUR REGION TONIGHT. WEAK HIGH PRESSURE BUILDING EASTWARD FROM THE
GREAT LAKES IS FORECAST TO INFLUENCE OUR WEATHER FOR TUESDAY AND
WEDNESDAY. A FRONTAL BOUNDARY FROM THE NORTHWEST IS EXPECTED TO
ARRIVE ON THURSDAY NIGHT FOLLOWED BY HIGH PRESSURE FOR FRIDAY AND
THE WEEKEND. ANOTHER FRONT MAY APPROACH FROM THE NORTHWEST ON
MONDAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
MOST OF THE REGION REMAINS DRY THIS AFTERNOON AND EVENING WHILE
CLOSER THE NEW JERSEY COAST SEA BREEZE CIRCULATION HAS IGNITED
SCATTERED SHOWERS WITH EMBEDDED THUNDER. LIKE DAYS PAST THERE IS
VERY LITTLE IN THE WAY OF SHEAR AS THE WINDS ALOFT REMAIN
RELATIVELY LIGHT SO VERY LITTLE IN THE WAY OF ANY DOWNWIND
PROPAGATION. SOME ISOLATED SHOWERS ALONG THE HIGHER TERRAIN IN OUR
NORTHWESTERN ZONES MAY PULSE UP THROUGH THE EVENING BUT THE AMOUNT
OF CLOUD COVER TODAY REALLY HAVE KEPT THE INSTABILITY AT BAY.
ACROSS SOUTHERN DELMARVA, CLOSER TO THE LINGERING/WASHED OUT
FRONTAL BOUNDARY, IS THE BEST PLACE TO SEE A PROLONGED PERIOD OF
SHOWERY ACTIVITY. THE ATMOSPHERE IS PRIME IN A LOT OF PLACES
OUTSIDE OF OUR WESTERN ZONES SO ANY LITTLE IMPULSE OR LOCALIZED
CONVERGENCE WILL BE ENOUGH TO GET THINGS GOING. ONCE THEY GET
GOING, WITH THE INCREASE IN PWATS AND RELATIVE LOW-TOPPINESS THESE
STORMS HAVE THEY WILL BE VERY EFFICIENT RAIN PRODUCERS...LOCALIZED
POOR DRAINAGE WILL CONTINUE TO BE AN ISSUE.

LATE TONIGHT ONCE THINGS BEGIN TO SETTLE DOWN OR SHIFT FARTHER TO
OUR SOUTH, PATCHY FOG FORMATION LOOKS PROBABLE. NOT SURE HOW DENSE
IT WILL BECOME, BUT ANY CLEARING TONIGHT WILL HELP TO AID IN ITS
DEVELOPMENT WITH LIGHT OR CALM WINDS. OVERNIGHT LOWS WERE A BLEND
OF THE MET/MAV.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
ONCE WE BURN OFF ANY FOG AND STRATUS THAT MAY FORM DURING THE
EARLY MORNING HOURS WE SHOULD BE LEFT WITH CLEARING SKIES, ALBEIT
SELF DESTRUCTING. A RAPID CU-FIELD SHOULD DEVELOP BY EARLY
AFTERNOON AS CONVECTIVE TEMPERATURES ARE REACHED WITH TEMPERATURES
CLIMBING INTO THE LOW-90S. WINDS WILL REMAIN RELATIVELY LIGHT SO
NO RELIEF IN TERMS OF THE HUMIDITY. SEA AND BAY BREEZES SHOULD
DEVELOP BY EARLY AFTERNOON AND GIVEN THE SOUPINESS OF THE AIR MASSTHEY
MIGHT BE ENOUGH TO GET ISOLATED SHOWERS STARTED.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
A MID LEVEL RIDGE AXIS IS FORECAST TO EXTEND ACROSS THE GREAT
LAKES ON TUESDAY NIGHT. THE RIDGE IS EXPECTED TO PROGRESS EASTWARD
AND ITS AXIS SHOULD PASS OVER OUR REGION ON WEDNESDAY NIGHT. A MID
LEVEL LOW IS ANTICIPATED TO MOVE FROM SOUTHERN MANITOBA ON TUESDAY
NIGHT TO HUDSON BAY ON WEDNESDAY NIGHT. THE LOW IS FORECAST TO
MEANDER OVER THE HUDSON BAY REGION FROM WEDNESDAY NIGHT THROUGH
MONDAY. MID LEVEL TROUGHING IS EXPECTED OVER THE NORTHEASTERN
STATES FOR THURSDAY NIGHT THROUGH MONDAY WITH A RIDGE BUILDING
OVER THE WESTERN STATES.

THE HEAT IS FORECAST TO BE ON THE INCREASE FOR WEDNESDAY AND
THURSDAY. WE ARE ANTICIPATING MAXIMUM TEMPERATURES MAINLY IN THE
LOWER AND MIDDLE 90S ON BOTH DAYS WITH HEAT INDEX VALUES
APPROACHING 100 EXCEPT IN THE ELEVATED TERRAIN AND IN THE
COMMUNITIES ALONG THE COAST. DEW POINT READINGS ARE EXPECTED TO BE
MAINLY IN THE MID TO UPPER 60S ON WEDNESDAY AFTERNOON AND IN THE
UPPER 60S AND LOWER 70S ON THURSDAY AFTERNOON.

THE MAXIMUM HEAT INDEX VALUES IN OUR HIGHLY URBANIZED AREAS ALONG
THE INTERSTATE 95 CORRIDOR ARE EXPECTED TO BE IN THE UPPER 90S ON
WEDNESDAY AND THURSDAY BASED ON THE LATEST GUIDANCE. AS A RESULT,
WE WILL NOT ISSUE AN EXCESSIVE HEAT WATCH AT THIS TIME. THE
GUIDELINE CRITERION IS 100. HOWEVER, WE WILL KEEP A CLOSE WATCH TO
SEE IF THE GUIDANCE BEGINS TO CREEP UPWARD WITH EITHER THE
TEMPERATURE OR DEW POINT FORECAST.

WE ARE NOT ANTICIPATING ANY PRECIPITATION FOR TUESDAY NIGHT,
WEDNESDAY AND WEDNESDAY NIGHT DUE TO THE LACK OF ANY SUBSTANTIAL
TRIGGERING MECHANISMS. WE WILL MENTION A CHANCE OF SHOWERS AND
THUNDERSTORMS FOR THURSDAY AFTERNOON INTO THURSDAY NIGHT AS A
FRONTAL BOUNDARY IS EXPECTED TO APPROACH AND PASS THROUGH OUR
REGION DURING THAT PERIOD OF TIME. A WEAK WAVE OF LOW PRESSURE MAY
DEVELOP ALONG THE FRONT CAUSING PRECIPITATION TO LINGER INTO EARLY
FRIDAY MORNING IN OUR SOUTHEASTERN COUNTIES.

HIGH PRESSURE IS EXPECTED TO FOLLOW THURSDAY NIGHT`S FRONTAL
PASSAGE. THE HIGH IS ANTICIPATED TO INFLUENCE OUR WEATHER FOR
FRIDAY AND THE WEEKEND. WE WILL CARRY A PRECIPITATION-FREE
FORECAST ALONG WITH SLIGHTLY ABOVE NORMAL DAYTIME TEMPERATURES.
EVEN WITH THE MID LEVEL TROUGHING, IT APPEARS AS THOUGH OUR
WEATHER WILL REMAIN QUITE WARM. HOWEVER, HUMIDITY LEVEL SHOULD
DROP A BIT FROM THOSE EXPECTED DURING THE MID WEEK PERIOD.

ANOTHER FRONTAL BOUNDARY MAY APPROACH FROM THE NORTHWEST ON
MONDAY AND WE WILL MENTION A CHANCE OF SHOWERS AND THUNDERSTORMS
FOR THAT PERIOD OF TIME.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

TONIGHT...VFR TRENDING TO MVFR/IFR. ISOLATED TO SCATTERED
MVFR/IFR SHOWERS WITH EMBEDDED THUNDER STILL POSSIBLE THROUGH THE
EVENING HOURS BEFORE DISSIPATING. OTHERWISE WINDS DROP OFF LATE
TONIGHT AND THE CEILINGS MAY LOWER TO MVFR...IFR FOG IS ALSO
POSSIBLE DEPENDING ON ADDED RAIN FROM SHOWERS. OVERALL A LOW TO
MEDIUM CONFIDENCE FORECAST.

TUESDAY...MOSTLY VFR. WE SHOULD LOSE ANY LOWER CLOUDS AND FOG BY
LATE MORNING LEAVING US WITH A SCATTERED CU FIELD. SHOWER CHANCES
WILL BE LOWER THAN THE PAST COUPLE OF DAYS WITH MIV/ACY HAVING
BETTER CHANCES. LOCAL SEA/BAY BREEZES MAY OCCUR AT ACY/MIV/ILG BY
THE EARLY AFTERNOON WITH WINDS BACKING MORE TOWARDS THE SOUTHEAST.

OUTLOOK...
TUESDAY NIGHT THROUGH THURSDAY MORNING...MAINLY VFR. HOWEVER, THE
HIGH HUMIDITY LEVELS MAY RESULT IN SOME LATE NIGHT AND EARLY
MORNING LOW CLOUDS, HAZE AND FOG.

THURSDAY AFTERNOON AND THURSDAY NIGHT...A CHANCE OF SHOWERS AND
THUNDERSTORMS THAT MAY RESULT IN MVFR OR IFR CONDITIONS AT TIMES.

FRIDAY THROUGH SATURDAY...MAINLY VFR.

&&

.MARINE...
SUB-SCA CONDITIONS EXPECTED TONIGHT AND TOMORROW UNDER PROLONGED
SOUTHERLY FLOW. WINDS WILL CONTINUE TO DECREASE TONIGHT AND
TOMORROW AS THE PRESSURE GRADIENT SLACKENS. SEAS WILL ALSO BE ON
THE DOWNWARD TREND RUNNING CLOSER TO 2-3 FEET THROUGH TUESDAY.

OUTLOOK...
TUESDAY NIGHT THROUGH SATURDAY...NO MARINE HEADLINES ARE
ANTICIPATED.

&&

.RIP CURRENTS...
A LONG PERIOD /10-12 SECOND/ EAST-SOUTHEAST SWELL LOOKS TO
CONTINUE, RESULTING IN A MODERATE RISK OF DANGEROUS RIP CURRENTS
THROUGH TONIGHT FOR THE NEW JERSEY AND DELAWARE COASTS.

&&

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

&&

$$

SYNOPSIS...IOVINO
NEAR TERM...HEAVENER
SHORT TERM...HEAVENER
LONG TERM...IOVINO
AVIATION...IOVINO/HEAVENER
MARINE...IOVINO/HEAVENER
RIP CURRENTS...HEAVENER



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