Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 280459
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1259 AM EDT TUE JUL 28 2015

.SYNOPSIS...
WEAK HIGH PRESSURE BUILDING EASTWARD FROM THE GREAT LAKES IS
FORECAST TO INFLUENCE OUR WEATHER TODAY THROUGH WEDNESDAY. A FRONTAL
BOUNDARY FROM THE NORTHWEST IS EXPECTED TO ARRIVE 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 THIS MORNING/...
A WEAK RIDGE OF HIGH PRESSURE WILL CONTINUE ITS HOLD ON THE MID-
ATLANTIC REGION OVERNIGHT. WITHOUT AN ORGANIZED LIFTING MECHANISM IN
PLACE, POPS WERE KEPT BELOW 15 PERCENT. THERE HAS BEEN A SHOWER
OR TWO POPPING UP, HOWEVER THE COVERAGE IS VERY ISOLATED.

CLOUD COVER WILL BE VARIABLE WITH SOME LINGERING DEBRIS CLOUDINESS
FROM LAST EVENINGS ISOLATED TO SCATTERED CONVECTION. FROM ABOUT
PHILADELPHIA TO THE SOUTH AND EAST, SOME LOWER CLOUDS ARE FLOATING
AROUND HOWEVER THESE SEEM TO BE DISORGANIZED ATTM. OTHERWISE WHERE
THE SKY FEATURES LESS CLOUD COVER THE LONGEST COMBINED WITH A MOIST
AIR MASS AND LIGHT WINDS, SOME FOG SHOULD DEVELOP THROUGH THE EARLY
MORNING HOURS.

THE HOURLY GRIDS WERE ADJUSTED BASED ON THE LATEST OBSERVATIONS,
THEN THE LAMP/LAV GUIDANCE WAS BLENDED IN.

&&

.SHORT TERM /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
MASS, THEY MIGHT PROVIDE ENOUGH LIFT TO INITIATE ISOLATED SHOWERS.

&&

.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 /06Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

THROUGH EARLY TUESDAY MORNING...VFR OVERALL, HOWEVER SOME MVFR
CEILINGS WILL BE AROUND AT TIMES ALTHOUGH AREAL COVERAGE IS OF LOWER
CONFIDENCE. WE CONTINUED WITH A TEMPO GROUP ALONG WITH SOME
VISIBILITY RESTRICTIONS AT SOME TERMINALS DUE TO SOME FOG
DEVELOPMENT. AN ISOLATED SHOWER COULD DEVELOP. LIGHT SOUTHERLY TO
CALM WINDS.

TUESDAY...ANY LOWER CLOUDS/FOG DISSIPATE BY MID MORNING, OTHERWISE
VFR WITH A CLOUD BASE MOSTLY SCATTERED BETWEEN 3500-5000 FEET. A FEW
ISOLATED SHOWERS OR A THUNDERSTORM MAY DEVELOP THROUGH THE DAY,
HOWEVER COVERAGE IS EXPECTED TO BE RATHER LOW. LOCAL SEA/BAY BREEZES
SHOULD OCCUR AT KACY, KMIV AND KILG BY MID AFTERNOON WITH WINDS
TURNING MORE FROM THE SOUTHEAST.

TUESDAY NIGHT...MAINLY VFR. HOWEVER DUE TO THE WARM AND MOIST AIR
MASS IN PLACE, SOME LATE NIGHT LOW CLOUDS, HAZE OR FOG MAY DEVELOP.
LIGHT SOUTHERLY TO CALM WINDS.

OUTLOOK...
WEDNESDAY 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 TONIGHT AND TUESDAY 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 MEDIUM TO LONG PERIOD (AROUND 10 SECONDS) SWELL OUT OF THE E-SE
WILL CONTINUE TUESDAY. SLY WINDS WILL BE AROUND 10 KT AND 2-3 FT
WAVES ARE FORECAST IN THE SURF ZONE. GIVEN SIMILAR CONDITIONS TO
MONDAY`S MODERATE RISK AND THE INFLUENCE OF AN APPROACHING FULL
MOON LATER IN THE WEEK, TOOK A CAUTIOUS APPROACH AND WENT WITH A
MODERATE RISK OF DANGEROUS RIP CURRENTS.

&&

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

&&

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



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