AREA FORECAST DISCUSSION
NWS BURLINGTON VT
AFDBTV 948 PM EST MON FEB 3 2003
WILL OPT TO UPDATE ZFP AND MAKE SOME CHANGES TO THE FIRST TWO
PERIODS. WILL CONTINUE WITH ALL CURRENT HEADLINES WITH THIS UPDATE
PACKAGE.
HI PRESS RIDGE TO BUILD OUT TO THE EAST OF THE FA TONITE...AS A STORM
SYS TRACKS ACRS THE GREAT LKS REGION. THIS STORM SYS TO TRACK ACRS
SRN CANADA ON TUE. IT/S ASSOCIATED CF TO SWEEP ACRS THE FA FROM THE
WEST BY LATE ON TUE.
18Z TAQ RUC SHOWS TEMPS TO BE IN THE LOWER TEENS-M20S EARLY TONITE...
THEN RISE WITH SFC WINDS BECOMING SOUTHERLY (EXCEPT ACRS THE ST LAW
VLY WHERE THE WINDS SHOULD STAY NE) AT 5-15 KTS. T1MIN TEMPS ARE IN
THE M-U20S TONITE. FEW TWEAKS TO FIRST PERIOD TEMPS BASED ON THIS
DATA AND CURRENT MESONET OBS. LOW-LVL MSTR TO MOVE IN ACRS THE FA
FROM THE WEST BY LATER TONITE. PW VALUES LOOK TO INCREASE TO AOB
0.75" ACRS THE FA BY LATER TONITE AND ON TUE. RUC SHOWS MOSTLY SN/PL
TO AFFECT THE NRN TIER ZONES BY AROUND 09Z TONITE...THEN ALL P-TYPES
ACRS THE FA BY AROUND 12Z (WITH MOSTLY LIQUID/FREEZING PCPN ACRS THE
CENTRAL/WRN ZONES). QPF APPEARS TO BE BLO 0.5" ACRS THE FA BY LATER
TONITE (LEAST IN THE ERN ZONES)...WITH MAYBE AN INCH OR TWO OF SN.
BUFCAN/88D MOSAIC SHOWS AN AREA OF PCPN MOVING IN TOWARDS THE FA FROM
THE WEST ATTM. LAPS DATA SHOWS THAT THE LOW LVLS ARE STILL TOO DRY TO
SUPPORT ANY SIGNIFICANT PCPN MAKING IT THE SFC THOUGH. HAVE PUSHED
BACK THE TIMING OF ANY PCPN TONITE AND LEFT CATEGORICAL POPS
BASICALLY INTACT.
STRONG H85 WAA TO TAKE PLACE ACRS THE FA TONITE AND EARLY ON TUE...
THEN STRONG CAA TO DEVELOP ACRS THE FA BY LATE ON TUE. H85 TEMPS TO
STAY BLO 0C ACRS THE FA TIL AROUND 12Z TUE...THEN GO BACK BLO 0C BY
AROUND 00Z WED. H925 WET-BULB TEMPS TO BE AOB 0C ACRS THE FA
TONITE...THEN GO ABOVE 0C FOR A TIME ON TUE...THEN BACK BLO 0C BY
AROUND 00Z WED. LOW-LVL LAPSE RATES TO BE HI ACRS THE FA ON TUE
AFTERNOON. GOOD LOW-LVL MSTR ADVECTION TO TAKE PLACE ACRS THE FA FOR
MUCH OF TONITE AND EARLY ON TUE. GOOD LOW-LVL MSTR TO AFFECT THE FA
ON TUE. GOOD MID-LVL MSTR TO AFFECT THE FA FOR MUCH OF TONITE AND ON
TUE.
2342Z ACARS SOUNDING INTO KSYR APPEARED TO SHOW THE FREEZING LVL AT
AROUND 7KFT...WHILE THE 12Z ETA BUFR DATA SHOWED IT AT AROUND 4KFT
AND THE 18Z MESO-ETA BUFR DATA SHOWED IT AT AROUND 5 KFT. THIS MAY
NOT BODE WELL FOR A PROLONGED PERIOD OF SOLID/FREEZING PCPN ACRS
PARTS OF THE FA OVER THE NEXT 24 HRS. STILL FEEL THAT THERE WILL BE A
PERIOD OF AT LEAST SOME -FZRA THOUGH...SO WINTER WX ADVISORIES STILL
LOOK GOOD ACRS THE FA FOR LATER TONITE AND EARLY ON TUE...BEFORE ANY
PCPN CHANGES OVER TO RAIN. BEST CHC FOR A PROLONGED PERIOD OF
SOLID/FREEZING PCPN SHOULD BE ACRS THE NRN ST LAW VLY AND THE FAR NE
KINGDOM OF VT.
NEXT ISSUE IS ANY HIR WINDS LATER TONITE AND ON TUE ACRS THE FA. H85
WINDS TO BE 45-55 KTS OUT OF THE S-SW LATE TONITE AND EARLY ON TUE.
H7 WINDS TO BE 35-60 KTS OUT OF THE SW LATE TONITE AND ON TUE. H5
WINDS TO BE 45-50 KTS OUT OF THE W-SW TONITE AND 45-75 KTS OUT OF
THE S-SW ON TUE. 1000MB GEOSTROPHIC WINDS TO BE 20-60 KTS OUT OF THE
SOUTH TONITE AND 30-60 KTS OUT OF THE SW ON TUE. ONLY SOME
AGEOSTROPHIC MOTION NOTED AT 850/1000MB ACRS THE FA OVER THE NEXT
24 HRS. BL WINDS TO BE 15-30 KTS OUT OF THE SE TONITE AND OUT OF THE
SW ON TUE. GOOD 24HR SFC PRESS FALLS OF AOB 40 MB ACRS THE FA. WITH
LACK OF HIR LOW-LVL LAPSE RATES UNTIL LATER IN THE DAY ON TUE AND
ONLY SOME MINOR AGEOSTROPHIC MOTION NOTED IN THE LOW LVLS OVER THE
NEXT 24HRS...HAVE MERELY INCREASED WIND SPEEDS ACRS MUCH OF THE FA
OVER THE NEXT 24HRS. LATER SHIFTS SHOULD BE ABLE TO RAISE ANY
NECESSARY HEADLINES ACRS THE FA FOR TUE (OR LATER).
WITH TOTAL QPF THRU 00Z WED EXPECTED TO BE BLO AN INCH AND SFC TEMPS
NOT PROGGED TO MAKE IT MUCH ABOVE 40F ON TUE...OFFICE CONSENSUS IS
STILL THAT ANY THREAT OF FLOODING WILL BE MINIMAL OVER THE NEXT
24HRS.
WRK ZONES OUT UNDER ALBWRKCWF. FINAL ZFP BY 10 PM. UPDATED WSWBTV
AFTER THAT.
.BTV...WINTER WX ADVISORY FOR OVERNITE THRU MID TUE MORNING FOR
NYZ026>031-034-035-VTZ001>012.
MURRAY
AREA FORECAST DISCUSSION
NWS SEATTLE WA
AFDSEW 310 PM PST MON FEB 3 2003
.SYNOPSIS...CLOUDS OVER WESTERN WASHINGTON WILL DISSIPATE OVERNIGHT
AS HIGH PRESSURE BUILDS OVER THE AREA. A STRONG UPPER RIDGE OF HIGH
PRESSURE OFFSHORE WILL BRING DRY WEATHER TO THE REGION FOR THE
REMAINDER OF THE WEEK.
.DISCUSSION...THE RIDGE...THE RIDGE...THE RIDGE IS BACK. CLOUDS
HANGING IN OVER WESTERN WASHINGTON WITH THE COMBINATION OF A SLIGHTLY
UNSTABLE AIR MASS AND LIGHT WINDS ALOFT. HIGH AMPLITUDE UPPER LEVEL
RIDGE OFFSHORE SLOWLY MOVING EASTWARD WITH THE RIDGE AXIS NEAR 135W.
AS THE UPPER LEVEL RIDGE CONTINUES TO MOVE EASTWARD TONIGHT...
SUBSIDENCE WILL INCREASE OVER WESTERN WASHINGTON WHICH WILL REDUCE
THE AMOUNT OF CLOUD COVER OVER THE AREA. ACARS SOUNDINGS INDICATE
LIGHT WINDS BELOW 5000 FEET AT 22Z BUT MODEL CROSS SECTIONS SHOW LOW
LEVEL WINDS INCREASING INTO THE 15 TO 20 KNOT RANGE BY TUESDAY
MORNING. THIS WILL HELP KEEP FOG AT A MINIMUM. BEYOND THAT...UPPER
LEVEL RIDGE REMAINING IN PLACE OFFSHORE THROUGH THE FORECAST PERIOD
WITH ENSEMBLES GIVING A STRONG SIGNAL LEADING TO HIGH CONFIDENCE.
SURFACE GRADIENTS FLOP AROUND BETWEEN NORTHWESTERLY AND NORTHEASTERLY
WITH THE NORTHEASTERLY GRADIENTS NEVER REALLY STRONG. WITH THIS IN
MIND WILL KEEP DAYTIME HIGHS NEAR CLIMO. WITH THE CLEAR SKIES AT
NIGHT...LOWS WILL BE ON THE COOL SIDE BUT NOWHERE NEAR RECORD LOWS
FROM COLD SPELL IN 1989. felton
UIL 1100 SEA 1100 OLM 1100
.KSEW...SMALL CRAFT ADVISORY COAST.
.KATX...VCP21/CSR21...OPERATIONAL.