Winter Storm in Vermont, February 25, 2001

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
303 AM EST SUN FEB 25 2001

.DISC...

.CORRECTION...CORRECTED TO TAKE OUT CORRECTION THAT WAS ERRONEOUSLY
LEFT IN THE HEADER PORTION OF THE PREVIOUS ISSUANCE.

.BOTTOM LINE...WRNG PROPS IN PLACE.  SEE NO RSN TO CHG CONFIGURATION.

.PROBLEM OF THE DAY...HOW FAST DOES SFC WRM/QP?

.SYNOPSIS...SFC HIPRES OVR NEW ENG MOVG OFF ATLC CST.  SRN STRM
TROAL VCNTY MS VLY EJECTING ENE SPAWNS LOPRES WHICH MOVS SO RPDLY
THAT IT/S FCST TO BE JUST S JMSBAY TEVE.  STG SLY GRAD WND FLO ACRS
CWA PRECEDES THE LOW...BUT XPC STBL LLVLS TO HOLD HIR MOMENTUM AIR
ALF.  DYNAMICS ARE MNLY INDUCED THRU ISENTROPIC UPLIFT TIL LTR TDA WHEN
ULVL VMAX MOVS OVR ERN GRTLKS.  TROAL BROADENS CSDRBLLY BY H+24
ALLOWING GRTR W TO E COMPONENT OF ULVL CRCLN WHICH DRIVES DRIER AIR
QUICKLY INTO/ACRS CWA TAFTN/TEVE.  CDFNT MOVS THRU CWA/OFF NEW ENG
CST BY DABRK MON...BUT ZNL ULVL CRCLN MON DOES NOT ALLOW DP
INTRUSION OF COLD AIR INTO NY/NEW ENG.  WK LOPRES FCST TO MOV ACRS
GRTLKS MON NGT AND ACRS NRN NY/NEW TUE...DRAGGING SCNDRY CDFNT SWD
INTO NRN CWA TUE.

.MDLS...H10/H8 THKNS ANALYSIS SHOWS ETA/AVN/GEM TRENDING WRMR THRUT
CWA...W ETA A BIT CDR THAN AVN/GEM.  RAFS TRENDG SLGTLY CDR THRU 18Z
IN ADRNDCKS...WRMR SRN HLF CWA...THEN GOES WRMR THAN PREV RUN THRUT
CWA BY 00Z/MON.  GEM FRZG ISOTHERM IN BNDRY LYR FURTHER N AT 18Z
THAN PREVLY (NRN BDR CT/E CAP DIST/WWD ALG SRN FRINGE OF SERN
ADRNDCKS).  ALL MDLS SUGGEST THAT BY 00Z ANY PCPN CONTG WL BE RAIN.
MM5 (SUNY) FOCUSES ON SRN HAMILTON EWD INTO SARATOGA/WARREN CO/S AS
THE RGN WHERE WORST ICING MAY OCR.  MM5 QPF SEEMS TO BE STGLY
INFLUENCED BY OROGRAPHY AND FCST NR 1.5 LE PCPN OVR AFOREMENTIONED
AREA...W A MERE 0.15 IN SHADOW TO N OF CTSKLS (SW OF CAP DIST).  MM5
IS FCSTG CHG TO RN FM LWR CTSKLS TO WRN CT/SRN BERKS BFR NOON...W
CHG OCRG LT AFTN XTRM NE CWA.  ABT AN INCH LE QP FCST IN THE
EPICENTER AREA BFR THE CHG OCRS ARND ERY AFTN.  UNLIKE MM5...GEM IS
FCSTG MUCH LWR QP TMRNG NRN CWA.  AND IT/S QPF IS LWR THAN 12Z/24
GEM RUN IN NRN CWA (VCNTY 0.30 TMRNG).  THE LWR RES ETA/AVN/RAFS ALL
FCSTG SIMILAR QPF...ABT HLF INCH TMRNG NRN FRINGE OF CWA...0.10 XTRM
SE.  IN MUCH OF CWA...THIS IS A WETTER FCST THAN PREV RUN.  DURG
AFTN...AVN/ETA/RAFS/GEM ALL FOCUS HVYST PCPN (ABT 0.25) XTRM SE...W
ARND 0.10 VCNTY KGFL TO KAVP.  THIS IS QUITE SIMILAR TO PREV RUN.
ALL MDLS FCST SOME LGT QP TNGT...W ETA/GEM/AVN RETAINING LGT QP...
MNLY NWRN CWA MON.  RAFS/GEM ARE DRY MON.

.SHORT TERM...LTST OBS SHOW PCPN HAS ARRIVED IN WRN NY.  FEW
STATIONS PICKING UP LE QP 0.10 PER HR (50 DBZ N KELM ON RADAR PRBLLY
SUGGESTS MELTING).  NRN PTN OF BAND OF TSTMS IN MIDW IS AS FAR N AS
MI.  SPC SAYING GENL TSTMS PSBL ACRS CWA W APCH OF OC/CDFNTL ZN LTR
TDA/TEVE.  SHEARING TROAL/QUICK DRYING ALF AND RATHER STBL SNDGS
SUGGEST OTRW...SO WL NOT INCLUDE TSTMS IN FCST.  FM LATEST MDL RUN
IT DOES NOT APR THAT QPF/TEMP FCST ARE IN PHASE TO VERIFY WRNG ACRS
SRN ZNS.  HWR...MM5 DOES FCST SUBSTANTIAL QP IN CTSKLS..AND FCST
SNDGS SUGGEST LINGERING BLO FRZG AIR THERE...AND THERE ARE SOME MDL
DISCREPENCIES...SO WL NOT CHG CONFIGURATION OF WRNG AREA.  TEMPS TO
SLOLY RS THRU THE DAY TO ABV FRZG ALL LOCS BY EVE.  MAV/FAN MAXT HIR
THAN FWC...AND GEM BNDRY LYR FCST AT H+24 AGREES FCSTG 41F ISOTHERM
CNTRL MA/SWRN VT BDR/KGFL.  GEM LOOKS TOO HI...BUT W STG SLY
DRAFT...IT/S PSBL.  WL LKLY RS MAXT SOMEWHAT FM PREV ZNS.

.LONG TERM...PER PREV FCST...WL GO W HI CHC/OR LKLY POPS TNGT.  CDR
AIR MOVG IN ALF SHOULD CHG -SHRA TO -SHSW NWRN CWA AFT MIDN.  PCPN
TO END SERN ZNS BFR CHG TO SNW IS PSBL.  MAV MIN/T MUCH HIR THAN
FAN/FWC SERN ZNS TNGT...BUT MUCH CLSR TO OTHER MOS N/W.  BASED ON
THKNS FCST AND WND DRCTN/SPD TWD DABRK...MAV MAY BE TOO HI.  WL
BLEND THE MOS FOR A MIN/T FCST IN S.

MOS SUGGESTS A DRY DAY MON.  PREV FCST HAD SOME SNW SHWERS IN NRN/
WRN PTN OF CWA.  ALTHO GEM/RAFS DRY MON...AVN/ETA/MM5 ARE FCSTG LGT
QP MON N AND W (AT LEAST IN MRNG)...SO WL NOT CHG PREV FCST.  ONCE
AGAIN...MAV MAXT MUCH HIR THAN OTHER MOS IN A PTN OF CWA.  A
BLENDING OF MOS SUGGESTS MAXT/S NR PREV ZN FCST.

.XTND FCST...GEM HMSPRHC/NOGAPS SAYS DRY MON NGT/TUE DESPITE SCNDRY
CDFNT.  AVN HAS MINOR QP FCST...FOCUSING ON NRN ZNS.  STRENGTHENING
ULVL VORTEX ERN NOAM MIDWEEK AIDS INTRUSION OF COLDER AIR INTO NERN
US.  GEM/NOGAPS SLGTLY CDR THAN AVN WED...ALL MDLS DRY.  CURRENT EFP
(CHC -SHSN) DOES NOT AGREE W DRY MDL FCST WED...MAY CHG IT.  APCHG
TROAL/SFC MAY DELIVER LGT SNW THU PER CURRENT EFP.

.ALY...WINTER STORM WARNING ALL ZONES TDA EXCEPT NYZJ063>066 AND
CTZ001 UNTIL ERY AFTN.

KHH