263
FXUS61 KPHI 101933
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
333 PM EDT TUE MAR 10 2026
WHAT HAS CHANGED
THE RISK FOR SOME STRONG TO SEVERE THUNDERSTORMS HAS INCREASED
SOME WEDNESDAY NIGHT.
KEY MESSAGES
1. AREAS OF PATCHY DENSE FOG POSSIBLE AGAIN TONIGHT. WARMTH AND
INCREASINGLY MORE HUMID CONDITIONS WEDNESDAY WITH RECORD HIGH
TEMPERATURES POSSIBLE.
2. A STRONG COLD FRONT CROSSES OUR REGION LATE WEDNESDAY NIGHT AND
THURSDAY MORNING WITH SHOWERS AND SOME POTENTIALLY STRONG TO SEVERE
THUNDERSTORMS.
3. LINGERING SHOWERS WILL BE POSSIBLE IN THE WAKE OF THE COLD FRONT
THURSDAY MORNING.
4. ANOTHER ROUND OF WIDESPREAD PRECIPITATION IS LIKELY SUNDAY NIGHT
INTO MONDAY NIGHT AS A STRONG COLD FRONT APPROACHES THE REGION.
DISCUSSION
KEY MESSAGE 1...AREAS OF PATCHY DENSE FOG POSSIBLE AGAIN TONIGHT.
WARMTH AND INCREASINGLY MORE HUMID CONDITIONS WEDNESDAY WITH RECORD
HIGH TEMPERATURES POSSIBLE.
ANOTHER ROUND OF FOG AND MIST IS POSSIBLE AGAIN THIS EVENING INTO
EARLY WEDNESDAY MORNING, BUT CONFIDENCE IN OCCURRENCE IS LOW. LATEST
GUIDANCE CONTINUES TO SUGGEST THAT THIS SLUG OF MARINE FOG WILL
LIKELY REMAIN MOSTLY OVER THE WATERS OR RIGHT ALONG THE COASTAL
STRIP.
SOUTHERLY FLOW INCREASES ON WEDNESDAY AS A STRONG COLD FRONT
APPROACHES FROM THE WEST AND THE PRESSURE GRADIENT TIGHTENS. SOUTH
TO SOUTHWEST WINDS WILL INCREASE WITH GUSTS 20-25 MPH. WARM AIR WILL
REMAIN IN PLACE, AND A MORE HUMID AIRMASS SPREADS INTO THE REGION
WITH DEW POINTS RISING INTO THE UPPER 50S TO LOW 60S. HIGH
TEMPERATURES ARE FORECAST TO BE IN THE MID TO UPPER 70S FOR MANY
PLACES, ALTHOUGH STILL MUCH COOLER ALONG THE COAST DUE TO A
SOUTHERLY WIND OFF THE COLD OCEAN. SEE THE CLIMATE SECTION BELOW FOR
THE RECORDS. THE WARMTH COULD BE MUTED SOME HOWEVER IF THICKER CLOUD
COVER ARRIVES FASTER DURING THE DAY WEDNESDAY. SOME SHOWERS SHOULD
START TO DEVELOP DURING THE COURSE OF THE DAY, ESPECIALLY LATER IN
THE AFTERNOON ACROSS OUR WESTERN ZONES.
KEY MESSAGE 2...A STRONG COLD FRONT CROSSES OUR REGION LATE
WEDNESDAY NIGHT AND THURSDAY MORNING WITH SHOWERS AND SOME
POTENTIALLY STRONG TO SEVERE THUNDERSTORMS.
LOW PRESSURE WILL TRACK TO OUR NORTH WEDNESDAY AND WEDNESDAY NIGHT.
THIS PULLS A STRONG COLD FRONT ACROSS OUR REGION LATE WEDNESDAY
NIGHT AND THURSDAY MORNING. SHOWERS DEVELOP WITH THE ARRIVAL AND
PASSAGE OF THE FRONT. A WARM AND MOIST ENVIRONMENT WILL BE IN PLACE
AHEAD OF THE COLD FRONT AND SOME THUNDER WILL BE POSSIBLE WITH THE
FRONT OR WITH A PRE-FRONTAL ZONE OF FORCING. AHEAD OF THE UPPER-
LEVEL TROUGH, VERY STRONG DEEP-LAYER SOUTHWESTERLY FLOW IS FORECAST
WITH AROUND 80 KNOTS AT 500 MB AND 50-60 KNOTS AT 850 MB. THIS WILL
RESULT IN STRONG SHEAR PROFILES THAT WOULD FAVOR LINE SEGMENTS WITH
LOCALLY STRONG TO DAMAGING WIND GUSTS, WITH A LOWER POTENTIAL FOR
SOME QUARTER SIZE HAIL OR AN ISOLATED TORNADO. OVERALL, THE GREATER
RISK FOR SEVERE THUNDERSTORMS LOOKS TO BE JUST TO OUR WEST WHERE
STRONGER FORCING COINCIDES WITH GREATER INSTABILITY WITH STRONG
SHEAR EARLIER IN THE DAY. HOWEVER, THE LATEST TREND IN GUIDANCE
POTENTIALLY SHOWS A SLIGHTLY EARLIER ARRIVAL TIME IN THE LATE
AFTERNOON TO EARLY EVENING. THIS EARLIER TIME WOULD POTENTIALLY
RESULT IN A HIGHER RISK FOR SEVERE STORMS WITH GREATER INSTABILITY
REMAINING ACROSS OUR REGION. SPC HAS EXPANDED THE SLIGHT RISK TO
INCLUDE MOST OF THE WESTERN AND SOUTHERN PORTIONS OF THE AREA AS A
RESULT.
KEY MESSAGE 3...LINGERING SHOWERS WILL BE POSSIBLE IN THE WAKE OF
THE COLD FRONT THURSDAY MORNING.
THE COLD FRONT CLEARS OUR REGION THURSDAY MORNING, THEN STRONG COLD
AIR ADVECTION DEVELOPS THROUGHOUT THE DAY. DRY AIR ADVECTION IS ALSO
EXPECTED IN THE WAKE OF THE FRONT, BUT THERE SHOULD BE A SMALL
WINDOW OF OPPORTUNITY BETWEEN THE COLD FRONT PASSAGE AND THE DRIEST
AIR ARRIVING FOR LINGERING SHOWERS TO CONTINUE. IN FACT FOR SOME
AREAS, THIS WILL BE THE HIGHEST CHANCES. BY THIS POINT HOWEVER, A
STRONG LOW LEVEL INVERSION WILL BE DEVELOPING, LIMITING INSTABILITY.
THUS, EXPECT THE MODE OF PRECIPITATION THROUGH THIS PERIOD TO BE
RAIN SHOWERS AS THE RISK FOR ANY THUNDERSTORMS APPEARS VERY LOW.
DAILY HIGH TEMPERATURES ARE LIKELY TO OCCUR JUST AFTER MIDNIGHT,
THEN TEMPERATURES THURSDAY FALL INTO AND THROUGH THE 50S IN THE
MORNING TO THE 40S BY LATE AFTERNOON AS STRONG NORTHWEST WINDS
DEVELOP BEHIND THE FRONT.
KEY MESSAGE 4...ANOTHER ROUND OF WIDESPREAD PRECIPITATION IS LIKELY
SUNDAY NIGHT INTO MONDAY NIGHT AS A STRONG COLD FRONT APPROACHES THE
REGION.
A LOW PRESSURE SYSTEM, TAKING A SIMILAR TRACK TO THE WEDENSDAY
SYSTEM, WILL BRING A STRONG COLD FRONT TO OUR REGION EARLY NEXT
WEEK. WIDESPREAD PRECIPITATION IS LIKELY AHEAD OF AND JUST BEHIND
THE FRONT. FOR NOW, FORECAST FAVORS A MOSTLY RAIN EVENT. ANY
POTENTIAL FOR WINTRY PRECIPITATION WILL BE HIGHLY DEPENDENT ON THE
TIMING OF BOTH THE PRECIPITATION AND THE FRONT. AT THIS RANGE, THOSE
DETAILS ARE HIGHLY UNCERTAIN.
MODELS SHOW VERY STRONG COLD AIR ADVECTION IN THE WAKE OF THIS COLD
FRONT. THUS, BY TUESDAY, WIDESPREAD HIGH TEMPERATURES IN THE 20S AND
30S ARE POSSIBLE.
AVIATION /19Z TUESDAY THROUGH SUNDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF TODAY...VFR WITH MAINLY CLEAR SKIES. SOUTH-SOUTHWEST WINDS
AROUND 5-10 KT. A SEA/RIVER BREEZE SHOULD DEVELOP AND TURN WINDS
SOUTH-SOUTHEAST AT KMIV, KACY, AND KILG IN THE AFTERNOON. HIGH
CONFIDENCE, WITH LOWER CONFIDENCE IN TIMING OF SEA BREEZE WIND SHIFT.
TONIGHT...PREVAILING VFR EXPECTED FOR MOST TERMINALS. THE EXCEPTION
IS NEAR KMIV AND KACY WHERE ANOTHER ROUND OF MARINE FOG, MIST, AND
STRATUS IS POSSIBLE. CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN
TAFS AT THIS TIME. SOUTH WINDS AROUND 5 KT OR LESS. LOW-MODERATE
CONFIDENCE.
WEDNESDAY...MAINLY VFR WITH INCREASING CLOUDS DURING THE DAY. CHANCE
(30-50%) FOR SHOWERS OR A THUNDERSTORM IN THE AFTERNOON. HIGHEST
CHANCES FOR KRDG, KABE, KILG. SOUTH-SOUTHWEST WINDS AROUND 10 KNOTS
WITH GUSTS UP TO 20 KNOTS. MODERATE CONFIDENCE.
OUTLOOK...
WEDNESDAY NIGHT...SUB-VFR CONDITIONS POSSIBLE WITH CONTINUING
CHANCES FOR SHOWERS AND THUNDERSTORMS. WIND GUSTS UP TO 30 KNOTS
POSSIBLE.
THURSDAY...CONDITIONS GRADUALLY IMPROVING TO VFR BY MID DAY. NW
WINDS GUSTING UP TO 35 KT.
FRIDAY THROUGH SUNDAY...PREVAILING VFR. ON FRIDAY, WINDS COULD GUST
TO 30 KT.
MARINE
SOUTH-SOUTHWEST WINDS AROUND 10-15 KT ARE EXPECTED THROUGH TONIGHT
WITH SEAS AROUND 2-3 FEET. AREAS OF PATCHY MARINE FOG THROUGH THE
REMAINDER OF THE DAY. ANOTHER ROUND OF DENSE MARINE FOG POSSIBLE
TONIGHT INTO EARLY WEDNESDAY MORNING.
WINDS INCREASE ON WEDNESDAY TO AROUND 15 KNOTS WITH GUSTS UP TO 25
KNOTS POSSIBLE. A CHANCE (15-30%) FOR SHOWERS IN THE AFTERNOON.
OUTLOOK...
WEDNESDAY NIGHT...SCA CONDITIONS LIKELY DEVELOPING WITH INCREASING
WINDS AND SEAS. CHANCE (25-45%) FOR SHOWERS AND THUNDERSTORMS.
THURSDAY...SCA CONDITIONS ARE LIKELY TO CONTINUE THROUGH MUCH, IF
NOT ALL OF THE DAY TIME HOURS. A LULL IN SCA CONDITIONS IS LIKELY
THURSDAY NIGHT.
FRIDAY...SCA CONDITIONS COULD REDEVELOP, ESPECIALLY FRIDAY AFTERNOON
INTO FRIDAY NIGHT.
SATURDAY...ELEVATED SEAS MAY LINGER INTO SATURDAY MORNING.
OTHERWISE, WINDS AND SEAS SHOULD BE BELOW SCA CRITERIA.
SUNDAY...SCA CONDITIONS MAY REDEVELOP, PRIMARILY LATE IN THE
DAY.
CLIMATE
NEAR RECORD HIGH TEMPERATURES ARE FORECAST FOR MARCH 10TH AND
11TH. RECORDS FOR OUR CLIMATE SITES ARE LISTED BELOW:
RECORD HIGH TEMPERATURES: MARCH 10
SITE............................RECORD/YEAR
ALLENTOWN (ABE).....................80/2016
AC AIRPORT (ACY)....................81/2016
AC MARINA (55N).....................68/2000 & 2016
GEORGETOWN (GED)....................80/2006
MOUNT POCONO (MPO)..................69/1977
PHILADELPHIA (PHL)..................82/2016
READING (RDG).......................79/2016
TRENTON (TTN).......................81/2016
WILMINGTON (ILG)....................80/2016
RECORD WARMEST LOW TEMPERATURES: MARCH 11
SITE............................RECORD/YEAR
ALLENTOWN (ABE).....................44/2006
AC AIRPORT (ACY)....................48/1955
AC MARINA (55N).....................51/2016
GEORGETOWN (GED)....................55/1955 & 1986
MOUNT POCONO (MPO)..................47/1955
PHILADELPHIA (PHL)..................54/1955
READING (RDG).......................51/1955
TRENTON (TTN).......................51/1955
WILMINGTON (ILG)....................48/1955
RECORD HIGH TEMPERATURES: MARCH 11
SITE............................RECORD/YEAR
ALLENTOWN (ABE).....................73/2021
AC AIRPORT (ACY)....................79/1967
AC MARINA (55N).....................70/1879
GEORGETOWN (GED)....................77/2021
MOUNT POCONO (MPO)..................66/1977
PHILADELPHIA (PHL)..................74/2021
READING (RDG).......................77/2021
TRENTON (TTN).......................73/2021
WILMINGTON (ILG)....................74/2021
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
DISCUSSION...AKL/GORSE/JOHNSON
AVIATION...AKL/JOHNSON
MARINE...AKL/JOHNSON
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