468 
FXUS61 KPHI 221320
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
920 AM EDT MON JUL 22 2013

.SYNOPSIS...
A NEARLY STATIONARY FRONT WILL BE DRAPED ACROSS OUR AREA TODAY, THEN 
SETTLE TO OUR EAST TONIGHT. A SECONDARY FRONT IS SCHEDULED TO MOVE 
THROUGH OUR AREA EARLY WEDNESDAY, BUT WILL JOIN THE EARLIER FRONT 
AND STALL OFF THE COAST THURSDAY THROUGH SATURDAY. A WEAK AREA OF 
HIGH PRESSURE BUILDS ACROSS TO OUR NORTH LATE WEDNESDAY INTO FRIDAY, 
THEN THE NEXT COLD FRONT IS FORECAST TO ARRIVE ON SUNDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WE ADDED SOME PATCHY FOG FOR THE NEW JERSEY COASTAL STRIP AS THERE
HAS BEEN SOME REPORTS OF FOG RIGHT NEAR THE BEACH IN SOME LOCATIONS.
THERE IS SOME LIGHT FOG/HAZE INLAND, BUT THE THICKEST FOG LOOKS TO
BE RIGHT NEAR THE COAST. WE ONLY KEEP IT THROUGH THE MORNING, BUT
WILL REVISIT LATER TO SEE IF WE NEED TO KEEP IT IN LONGER.
OTHERWISE, MOSTLY CLOUDY, WITH HAZY CONDITIONS THIS MORNING AND
SCATTERED SHOWERS DEVELOPING THROUGH THE DAY.

AN H5 TROF AXIS WILL BE POSITIONED TO THE W, A STALLED FRONTAL 
BOUNDARY NEAR BY AND SOME S/WV ENERGY WILL MOVE ACRS THE AREA.  ALL 
OF THIS MEANS WE WILL SEE SOME SHOWERS AND PSBLY SOME TSTMS ONCE 
AGAIN, BUT THE EXACT TIMING AND LOCATION IS DIFFICULT TO NAIL DOWN, 
DUE TO THE INHERENT MDL DIFFS WITH THE S/WVS.  THE GFS DOES APPEAR 
TO BE SUFFERING FROM SOME CONVECTIVE FEEDBACK PROBS WHICH WILL 
IMPACT ITS SOLN, BUT NEVERTHELESS ALL OF THE MDLS INDICATE SOME 
PRECIP FOR TODAY, WITH THE BEST CHCS MOST LIKELY IN THE SECOND HALF 
OF THE DAY AND PROBABLY OVER NRN AREAS.

DEPENDING ON CLOUD COVER AND SHOWER ACTIVITY, THAT COULD HAVE AN 
IMPACT ON TEMPS AS WELL AND HAVE TRENDED TWD A MIDDLE OF THE ROAD 
SOLN BETWEEN THE WARMER MAV (WHICH HAS BEEN DOING BETTER OF LATE) 
AND THE COOLER MET.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
DEPENDING ON WHICH MDL YOU BELIEVE, THE EARLY PORTION OF THE SHORT 
TERM COULD BE THE WETTEST PD...OR NOT...AGAIN ALL DEPENDENT ON 
TIMING AND STRENGTH OF S/WVS MOVG THRU THE AREA.  HOWEVER, BUT POPS 
SHOULD DECREASE TWD DAYBREAK.  MOS GUID WAS IN BETTER AGREEMENT HERE 
AND WAS GENLY FOLLOWED.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
THE OVERALL SYNOPTIC SETUP IS COMPRISED OF AN UPPER-LEVEL TROUGH IN 
THE EAST. THIS FEATURE WILL ADJUST A FEW TIMES IN AMPLITUDE, WHICH 
WILL RESULT IN SOME FRONTAL BOUNDARIES DRIVING SOUTHEASTWARD. THE 
TIMING OF THE SHORT WAVE ENERGY TRAVELING WITHIN THE FLOW IN THE 
UPPER-LEVEL TROUGH WILL BE THE MAIN TRIGGER TO INITIATE SOME SHOWERS 
AND THUNDERSTORMS. WHILE THERE IS SOME UNCERTAINTY REGARDING THE 
DETAILS DUE TO THE TIMING OF SUCH FEATURES, IT DOES APPEAR THAT 
TUESDAY IS THE DAY TARGETED FOR BETTER CONVECTIVE CHANCES WITH MUCH 
LESSER CHCS WEDNESDAY AND THURSDAY. OVERALL, THIS PATTERN WILL RESULT
IN CONTINUED RELIEF FROM LAST WEEKS OPPRESSIVE HEAT AND HUMIDITY.

FOR TUESDAY AND WEDNESDAY...A MAIN IMPULSE IS FORECAST TO LIFT 
ACROSS OUR AREA DURING TUESDAY WITH A SURFACE BOUNDARY IN THE 
VICINITY. THERE SHOULD BE A SURFACE LOW ASSOCIATED WITH THE MID 
LEVEL FEATURE, WHICH WILL TEND TO ENHANCE THE PRECIPITATION CHCS 
SOME. THE INCREASING ASCENT WITH THE MID LEVEL SHORT WAVE WILL ACT 
UPON A MOIST AND UNSTABLE ENVIRONMENT. AS A RESULT, WE ARE 
ANTICIPATING SHOWERS AND SCATTERED THUNDERSTORMS TO BECOME MORE 
NUMEROUS DURING THE DAY. THE MOST ORGANIZED ACTIVITY MAY END UP 
BEING NEAR A WEAK SURFACE LOW THAT TRACKS ACROSS THE CWA. A PLUME OF 
PW VALUES OF 2 INCHES REMAINS AHEAD OF THIS FEATURE, THEREFORE BANDS 
OF SHOWERS AND SOME THUNDERSTORMS WILL BE CAPABLE OF PRODUCING 
LOCALLY HEAVY RAIN. THE STEERING FLOW STILL APPEARS TO BE 20 KNOTS 
OR LESS TUESDAY, THEREFORE SLOW MOVING CONVECTIVE ELEMENTS MAY 
PRODUCE LOCALIZED FLOODING. THERE COULD BE SOME STRONG CONVECTION IF 
POCKETS OF HIGHER INSTABILITY CAN BE ACHIEVED, HOWEVER GIVEN THE 
WEAKER FLOW ANY SEVERE THREAT LOOKS LOW ATTM. A LOCALIZED DOWNBURST 
CANNOT BE RULED OUT THOUGH TUESDAY AFTERNOON DUE TO WATER LOADING 
WITHIN SOME PULSE STORMS. THE CONVECTION SHOULD TAPER OFF IN THE 
EVENING AS MOST APPEARS TO BE AIDED BY DAYTIME HEATING. THEREFORE, 
CARRIED CHC TO LIKELY POPS DURING THE DAY THEN TAPERED TO CHC IN THE 
EVENING THEN SLIGHT CHC EVERYWHERE OVERNIGHT.

IT NOW APPEARS THAT THE MAIN SHORT WAVE LIFTS NORTHEAST OF OUR AREA 
FOR WEDNESDAY WITH WEAK SURFACE HIGH PRESSURE APPROACHING FROM THE 
GREAT LAKES. THIS WOULD RESULT IN THE COLD FRONT ALREADY TO OUR EAST 
AND A DRY DAY WITH A NOTABLE DRIER NORTHWESTERLY FLOW. THE 
ECMWF/ECMWF MEAN/UKMET AND NAM APPEAR TO BE THE MOST CONSISTENT AND 
AGREEABLE GUIDANCE WITH THIS FEATURE AND ITS ASSOCIATED COLD FRONT. 
THEREFORE, SOME OF THE MODEL GUIDANCE SUGGESTS THAT THE SURFACE DEW 
POINTS DROP INTO THE 50S IN THE AFTERNOON FOR ABOUT THE NORTHERN 
HALF OF THE CWA. IF CORRECT, THIS WILL BE A RATHER NOTABLE CHANGE 
FROM THE OPPRESSIVE HUMIDITY OF LAST WEEK. THE SURFACE FRONT SHOULD 
BE FAR ENOUGH SOUTH AND EAST OF THE AREA, WHICH RESULTS IN A DRIER 
WEDNESDAY NIGHT. WE DID LOWER THE DEW POINTS SOME, HOWEVER DID NOT 
GO AS LOW AS SOME OF THE GUIDANCE IS SHOWING GIVEN SOME LOWER 
CONFIDENCE WITH THE SOUTHERN EXTENT OF THE PUSH OF DRIER AIR. 

FOR THURSDAY AND FRIDAY...THERE STILL REMAINS AT LEAST SOME 
UNCERTAINTY, ESPECIALLY REGARDING THE PLACEMENT OF A STALLED OUT 
SURFACE FRONT. IT APPEARS THE GUIDANCE IS EDGING THIS BOUNDARY 
FARTHER EAST WHICH WOULD RESULT IN LESS CHCS FOR CONVECTION. THERE 
STILL IS THE UPPER-LEVEL TROUGH IN PLACE, HOWEVER THE AMPLITUDE OF 
THIS DIFFERS SOME AMONG THE GUIDANCE. IF WE CAN MAINTAIN A PLUME OF 
HIGHER PW VALUES ESPECIALLY CLOSER TO THE COAST, THIS MAY ASSIST IN 
SOME MAINLY AFTERNOON AND EVENING CONVECTION. SOME GUIDANCE HOWEVER 
SUGGESTS THE PW VALUES DROP SIGNIFICANTLY TO PUT A LID ON CONVECTION 
BOTH DAYS. ON THE OTHER HAND, SOME GUIDANCE INDICATES A LEAD
SHORT WAVE SHARPENING UP ACROSS THE MID ATLANTIC FRIDAY, WHICH
WOULD BRING INCREASED CHCS FOR SHOWERS/THUNDER TO OUR AREA. FOR
NOW, DID NOT GO ANY HIGHER THAN LOW CHC POPS GIVEN THE LOWER
CONFIDENCE WITH THE DETAILS/TIMING.

FOR SATURDAY AND SUNDAY...THE UPPER-LEVEL TROUGH IS FORECAST TO 
AMPLIFY ACROSS THE MIDWEST AND GREAT LAKES SATURDAY, THEN ACROSS THE 
NORTHEAST SUNDAY. THIS WILL DRIVE ANOTHER COLD FRONT INTO OUR AREA 
SUNDAY, WITH A CHC FOR SOME SHOWERS AND THUNDERSTORMS. AS OF NOW, 
THE BEST LARGE SCALE LIFT WITH THE UPPER-LEVEL TROUGH MAY TRACK TO 
OUR NORTH WHICH WOULD LIMIT THE OVERALL PRECIPITATION CHCS. OVERALL,
POPS WERE CLOSE TO THE 00Z WPC GUIDANCE.

&&

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

TAFS REMAIN VARIABLE THIS MORNING FROM SITE TO SITE. IFR/MVFR
CONDITIONS PERSIST FOR TTN/PNE/ACY AND WILL CONTINUE FOR ANOTHER
COUPLE OF OURS UNTIL THE SUN IS ABLE TO WORK THROUGH THE CLOUDS
AND MIX THINGS OUT. ONCE THIS HAPPENS, A GENERAL VFR FCST IS
EXPECTED. THE REST OF THE TAF SITES HAVE REMAINED VFR SO FAR THIS
MORNING, AND ARE CURRENTLY EXPECTED TO REMAIN SO.

-SHRA WILL MOVE IN FOR ALL TAF SITES BY AFTERNOON. IT SHOULD BE
LIGHT ENOUGH FOR MAINLY VFR CONDS. HOWEVER SOME LOWER CIGS/VSBYS
CAN NOT BE RULED OUT, CERTAINLY IF THERE ARE TSRA.

BY NIGHTFALL, THERE COULD BE SOME ADDITIONAL -SHRA OR A MORE 
WIDESPREAD MVFR CIG AND VSBY EVENT.  BUT ONCE AGAIN, THE MDLS HAVE 
OVERDONE THIS FOR SEVERAL NIGHTS, SO UNLESS THERE IS ONGOING RAIN, 
CONFIDENCE IS QUITE LOW.   THE WIND WILL BE E TO SE AND LESS THAN 10 
KT DURG THE DAY....DECREASING TO LESS THAN 5 KT AT NIGHT.

OUTLOOK...
TUESDAY...MAINLY VFR. HOWEVER, EARLY MORNING MVFR/IFR CONDITIONS
ARE POSSIBLE DUE TO SOME LOW CLOUDS/FOG. SOME SHOWERS AND 
THUNDERSTORMS ARE EXPECTED, ESPECIALLY IN THE AFTERNOON, WITH
SUB-VFR CAN OCCUR IN HEAVIER SHOWERS/THUNDERSTORMS.

WEDNESDAY...VFR. NORTHWEST WINDS 10-15 KNOTS.

THURSDAY AND FRIDAY...MOSTLY VFR, HOWEVER THERE IS A CHANCE FOR 
LOCAL MVFR FOG DURING THE EARLY MORNING HOURS.

&&

.MARINE...
WE HAVE ADDED SOME PATCHY FOG FOR THE NEW JERSEY COASTAL WATERS
AND LOWER DELWARE BAY AS THERE HAS BEEN SOME REPORTS OF SOME FOG
ALONG THE WATERS. WE ONLY KEPT IT THROUGH THE MORNING, BUT WILL
REVISIT LATER IN THE MORNING TO SEE IF WE NEED TO EXTEND IT OUT.
OTHERWISE, RELATIVELY QUIET CONDS ON THE AREA WATERS WITH WK
FLOW. SEAS WILL BE AROUND 3 FT AND WIND GENLY IN THE 10 15 KT
RANGE. THEREFORE NO HEADLINES ARE EXPECTED DURG THE NEAR OR SHORT
TERM PDS.

OUTLOOK...
THE CONDITIONS ARE ANTICIPATED TO BE BELOW SMALL CRAFT ADVISORY 
CRITERIA THROUGH FRIDAY. A FRONTAL BOUNDARY LURKING NEAR THE AREA 
WILL BE JOINED BY A SECOND ONE EARLY WEDNESDAY. IT APPEARS THAT THIS 
BOUNDARY MAY THEN BE PUSHED FAR ENOUGH TO THE EAST. THIS WILL RESULT 
IN THE WINDS BECOMING NORTHERLY WEDNESDAY THROUGH FRIDAY AS WEAK 
HIGH PRESSURE BUILDS TO OUR NORTH. IT APPEARS THAT THE WAVEWATCH 
GUIDANCE IS ON THE HIGH SIDE TUESDAY INTO WEDNESDAY /SEEMS TO BE A 
PATTERN THIS WARM SEASON/, WHICH IS PROBABLY TIED TO THE GFS HAVING 
A MORE DEFINED SURFACE LOW. THEREFORE, WE SHAVED ABOUT A FOOT FROM 
THIS GUIDANCE.

&&

.TIDES/COASTAL FLOODING...
THE FULL MOON IS TODAY AND ASTRONOMICAL TIDES ARE RUNNING QUITE
HIGH. WE WILL BE VERY CLOSE TO MINOR TIDAL FLOODING CRITERIA FOR
THE EVENING TIDAL CYCLE AT A FEW SITES. A COASTAL FLOOD ADVISORY
MAY BE NEEDED WITH LATER SHIFTS. WILL CONTINUE TO MONITOR.

&&

.EQUIPMENT...
THE KNEL /LAKEHURST/ TEMPERATURE DATA IS INACCURATE AND HAS BEEN
SINCE ABOUT MARCH 9TH. IT IS RUNNING ABOUT 8 TO 10 DEGREES TOO
WARM AND THE PROBLEM IS PARTICULARLY NOTICEABLE DURING THE DAYTIME
HOURS. USE OF THIS INFORMATION BY THE NWS WAS SUSPENDED IN EARLY
APRIL HERE AT MOUNT HOLLY WHERE WE NO LONGER POSTED THE
INFORMATION IN OUR HOURLY WEATHER ROUND UP AND THE TWICE DAILY
REGIONAL TEMPERATURE AND PRECIPITATION SUMMARY SENT AT 815 AM AND
PM.

WE ARE DEEPLY CONCERNED WITH RECENT MEDIA REPORTS CITING THIS
ERRONEOUS DATA, AND IN SOME CASES ATTRIBUTING IT TO THE NWS. KNEL
IS A DOD SITE AND HAS BEEN NOTIFIED MULTIPLE TIMES THAT THEIR
DATA IS IN ERROR. NO CORRECTIVE ACTION HAS BEEN TAKEN THAT WE ARE
AWARE OF.

PLEASE BE EXTREMELY CAUTIOUS WITH THIS DATA SET. THE NWS IN MOUNT
HOLLY DOES NOT USE IT. THANK YOU.

&&

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

&&

$$
SYNOPSIS...GORSE
NEAR TERM...NIERENBERG/ROBERTSON
SHORT TERM...NIERENBERG
LONG TERM...GORSE
AVIATION...GORSE/NIERENBERG/ROBERTSON
MARINE...GORSE/NIERENBERG/ROBERTSON
TIDES/COASTAL FLOODING...
EQUIPMENT...