Winter Weather and Freezing Fog in New Jersey, January 31, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
300 AM EST THU JAN 31 2002

WE ARE UNABLE TO SHIP GRIDDED DATA DOWN TO THE ZONES IN GFE W/O
GETTING A COMBO DEFINTION ERROR. THUS ZONES WILL HAVE TO BE TYPED
THE OLD-FASHIONED WAY AND PRODUCTS WILL BE DELAYED...TRUNCATED OR
MISSING. WE APOLOGIZE.

NOT TOO MANY CHGS WITH THIS FCST PKG AS MDLS CONT TO BE PRETTY
CLOSE. THE GENERAL TREND HAS BEEN TO SHIFT AXIS OF HEAVIEST PCPN
FTHR TO THE N AND ONE HAS TO QUES HOW MUCH PCPN IS ACTUALLY GOING TO
FALL IN THE SRN 2/3RDS OF OUR CWA. WE WILL CONT THE WINT WX ADVY FOR
SIX OF OUR NRN CTYS BASED ON ETA/S FCSTD WET BULB TEMPS AND SRN
EXTENT OF 552 THICK WHICH APRS IN LINE FOR NOW WITH FRZG PCPN IN OH.
STG CFP LATE IN THE DAY ON FRI...BUT NOT B4 MORE RECORD HIGHS MAY
FALL.

PROBLEM OF THE DAY TDY FOR NRN CTYS HAS SHIFTED TO MORE OF A QPF
QUES THAN PTYP. MDL RUNS HAVE BACKED AWAY FROM HAVING HVYR PCPN FALL
ACRS OUR NRN ZNS AND NOW LATEST SREF HAS .25 ISOHYET JUST TOUCHING
OUR NRN ZONES. SFC DEWPTS HAVE DROPPED BLO FRZG UP N AND PCPN SHLD
START AS FROZEN/FRZG UP THERE...BUT THIS MAY NOT BE UNTIL THE MRNG
HRS BASED ON LATEST RADAR TRENDS. MDLS PRETTY INSISTENT ON BRINGING
WRMR AIR NWD PRETTY QUICKLY...SO THREAT OF ANY FRZG PCPN SHLD BE OVR
BY EVE. WE HAVE USED SRN EXT OF ETA 552 THICK AND WET BULB TEMPS BLO
0C FOR CONTINUATION OF ANY ADVYS. THUS WE WILL SHAVE OFF A FEW OF
OUR SRN CTYS OFF FROM THE CUR ADVY. MDL QPF HAS BEEN TRENDING DRIER
AND WITH MOST OF THIS PCPN OCRG DURG THE DAYLIGHT HRS...SHOULD HELP
MITIGATE SOME OF THE FZRA PBLMS. THE FACT WE WERE BREAKING RECORDS
LAST COUPLE OF DAYS WON/T HURT MATTERS EITHER.

FTHR TO THE S IT BCMS PROBLEMATICAL ABT HOW MUCH PCPN. CUR SHRTWV IS
DOING A GOOD JOB OF DVLPG PCPN OVR WV/MD AND MOVG IT EWD. ONCE THIS
FEAT EXITS THE AREA...OTHER THAN A MOIST LLVL OCEANIC FLOW...IT
DOESN/T LOOK LIKE MUCH PCPN. MDLS/S FGEN FRCG AND WAA ARE ALL IN NY
STA AND LLVL THETA E ADVT WHICH RUNS ALG THE 180 CORRIDOR AT 12Z
LIFTS INTO NY STA ALSO BY 18Z. WE WILL LOOK AT LATEST RADAR TRENDS
IN DETERMINING POPS...BUT CUR PLANS ARE TO TRY TO SCALE BACK POPS AS
MUCH AS PSBL AND PBLY ONLY MNTN DRIZZLE IN FAR SRN ZNS. IT WOULD APR
SRNMST EXTENT OF MODIFIED ARCTIC AIR WILL BE THIS MRNG B4 WE START A
SLOW CLIMB UPWARD. WE PRFR COOLER NGM MOS SCHEME OVR WRMR MAVS.

NOT MUCH FORCING FOR PCPN FOR TNGT. WE PLAN ON JUST MNTNG FOG AND
DRIZZLE IN MOST OF THE ZNS. SRN ZONES WILL PBLY SHOW IPVMNT IN 2ND
HALF OF NGT AS IT APRS BOUNDARY LYR WINDS ARE TOO STG TO DECOUPLE
EVEN IN THE MARTINE ENVIRONMENT. THO STILL LIKE THE MORE
CONSERVATIVE APCH AS DEPICTED BY NGM MOS. MAV POPS LOOK TOO WET.

THEN ON FRI CWA SHOULD ONCE AGAIN BE BASKING IN AN UNSEASONABLY WARM
AIR MASS FOR MOST OF THE DAYLIGHT HRS. RECORD HI TEMPS ARE IN THE
UPR 50S TO THE UPR 60S AND COULD EASILY FALL (AGAIN). MAIN FCST
CONCERN WILL BE LINE OF SHRAS TYHAT SHLD DVLP (OR APRS LIKELY) AT
THIS JUNCTURE WITH CWA IN ENTR RGN OF STG H2.5 JET. ETA ATTM IS NOT
FCSTG ANY SB CAPES AND BRINGS LI AND TT TO MINIMAL THRESHOLD FOR
THUNDER. FOR NOW WE WILL NOT INCLUDE ANY IN THE FCST. ONE BIG
DOWNSIDE OF UNSEASONABLY WARM WX IN THE WINTER...WIND FIELDS ARE
VERY STG AND DOESN/T TAKE MUCH CONVECTION TO MIX IT DOWN...ONE OF
THOSE ANNOYING 99.4% GRADIENT/.6% THUNDER CONTRIBUTION TO THE WIND
FIELD. HIGH WIND CHECK LIST SUGG GUSTS TO 45KT PSBL AND WE WILL HAVE
TO LOOK AT THIS FTHR OVR THE NEXT COUPLE OF MDL RUNS. THE TIGHTEST
GRAD PASSES THRU THE RGN FRI NGT AND THE WEEKEND LOOKS LIKE A RETURN
OF SEASONABLY COLD TEMPS.

BEYOND THAT AVN HAS SHIFTED THE ALBERTA CLIPPER/2NDRY CYCLOGEN
SLGTLY FTHR OFSHR WITH THIS RUN. ALL THE MED RNG MDLS HAVE THIS FEAT
BOMBING OFSHR...SO IT WILL BE WORTH WATCHING.  NO BIG CHGS SEEN WITH
THE EXTDD.

MAR: SCA FOR CSTL WATERS AND LWR DE BAY.

.PHI...
DE...NONE.
MD...NONE.
NJ...WINTER WX ADVY FOR TDY NJZ1/7/8
PA...WINTER WX ADVY FOR TDY PAZ54/55/62
MARINE...SCA FOR CSTL WATERS AND LWR DE BAY.

TFG