Winter Weather in Vermont, March 3 to 4, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
300 PM EST SAT MAR 3 2007

FCST CHALLENGE WL BE CHCS FOR SHOW SHOWERS AND TIMING OF ARCTIC
SURGE ON MONDAY ACRS OUR FA.

WL ISSUE SPS FOR BLACK ICE POTENTIAL FROM MELTING SNOW TODAY AND
RE-FREEZING TONIGHT WHEN TEMPS DROP BACK INTO THE 20S.

.SYNOPSIS...
UPPER DATA AND WATER VAPOR THIS AFTN SHOWS CENTER OF MID/UPPER LVL
CYCLONIC CIRCULATION OVER THE NORTHERN GREAT LAKES WITH GENERAL
MOVEMENT TOWARD EASTERN CANADA. THIS FEATURE WL CONT TO FILL AND
WEAKEN OVER THE NEXT 12 TO 24 HRS...BUT SEVERAL PIECES OF ENERGY AND
RIBBONS OF MOISTURE WL KEEP PATTERN UNSETTLED ACRS OUR CWA THRU
MONDAY NIGHT. THE LFQ OF 160 TO 180 KNT JET ACRS THE SOUTHERN MID
ATLANTIC STATES COMBINED WITH ELONGATED VORTICITY STREAK HAS HELPED
TO PRODUCE AN EXPANDING AREA OF PRECIP FROM EASTERN NY INTO
CENTRAL/SOUTHERN VT THIS AFTN. THE GFS MOISTURE/OMEGA FIELDS HAVE
HANDLED THIS SYSTEM NICELY...ALONG WITH DEVELOPMENT OF WEAK AREA OF
LOW PRES OVER SE NY TODAY...AND WL USE FOR FIRST 6HRS OF FCST
TONIGHT ACRS OUR CENTRAL/SOUTHERN VT ZNS.

OTHERWISE...VIS SAT PIC THIS AFTN SHOWS PLENTY OF CLOUDS DEVELOPING
ACRS THE AREA WITH SCATTERED MAINLY SNOW SHOWERS IMPACTING OUR
CENTRAL/NORTHERN MTN ZNS. TEMPS HAVE WARMED INTO THE MID 30S MTNS TO
L40S WARMER VALLEY LOCATIONS...MAKING FOR A PLEASANT AFTN FOR
OUTDOOR ACTIVITIES.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
THIS EVENINGS FOCUS WL BE POTENTIAL FOR LIGHT SNOW ACCUMULATION ACRS
OUR CENTRAL/SOUTHERN MTNS ZNS...THEN MORE SNOW SHOWER ACTIVITY OVER
THE REST OF THE FA LATE TONIGHT THRU MONDAY. GFS SHOWS WEAK SFC
LOW PRES TRACKING FROM SE NY THIS AFTN INTO THE GULF OF MAINE BY
TONIGHT WITH A BAND OF GOOD LIFT/MOISTURE MOVING ACRS OUR
CENTRAL/SOUTHERN CWA. IN ADDITION...THERE IS A GOOD BAND OF
850-700MB FGEN FORCING AND SOME MODERATE 850-500MB Q-VECTOR
CONVERGENCE ACRS OUR SOUTHERN ZNS. WL CONT TO MENTION LIKELY POPS
WITH ACCUMULATIONS OF DUSTING TO 2 INCHES THRU THE REST OF TODAY.
OTHERWISE...BOTH GFS/NAM SOUNDINGS SHOW DEEP LAYER MOISTURE
DEVELOPING ACRS OUR CWA TODAY AS MOISTURE FROM MID/UPPER LVL
CIRCULATION ADVECTS INTO OUR FA. HOWEVER...LIMITED LIFT WL BE
PRESENT...THEREFORE WL ONLY MENTION CHC/LIKELY POPS NORTHERN MTNS TO
SCHC POPS ACRS THE VALLEY LOCATIONS TONIGHT. TEMPS WL BE TRICKY AND
HIGHLY DEPEND UPON CLOUDS...BUT FEEL STRONG ABOUT DEVELOPMENT OF
CLOUDS ACRS ENTIRE FA TONIGHT...THEREFORE WL TREND TOWARD WARMER
GUIDANCE NUMBERS.

SUNDAY-SUNDAY NIGHT...SEVERAL WEAK SFC TROFS MOVE ACRS OUR FA FROM
WEST TO EAST AND WL ACT TO ENHANCE LLVL CONVERGENCE. THIS COMBINED
WITH PLENTY OF 850-500MB MOISTURE AND DEVELOPING AREA OF SFC TO
700MB UVVS WL INCREASE POPS TO LIKELY ACRS OUR MTNS ZNS...BUT KEEP
CHC POPS IN THE VALLEYS. IN ADDITION...DEVELOPING UPSLOPE FLW WL
HELP TO ENHANCE PRECIP CHCS ON SUNDAY. PROGGED 1000MB AND 925MB
TEMPS ARE 3 TO 5 DEGREES COOLER THAN TODAY...ALONG WITH INCREASED
CLOUD COVER...WL MENTION TEMPS L30S MTNS TO M/U 30S VALLEY
LOCATIONS. SNOW ACCUMULATIONS WL BE LIGHT GENERALLY A TRACE TO 2
INCHES. SUNDAY NIGHT...ANOTHER 5H VORT LIFTS FROM WEST TO EAST ACRS
OUR FA AND HELP TO PRODUCE ENOUGH LIFT FOR MORE SNOW SHOWERS. ONCE
AGAIN QPF WL BE LIGHT WITH TEMPS GENERALLY IN THE 20S.

MONDAY-MONDAY NIGHT...FCST CHALLENGE WL BE TIMING OF SHARP ARCTIC
FRNT ACRS OUR FA. THIS LLVL CONVERGENCE WL HELP TO ENHANCE MOISTURE
ALONG THE BOUNDARY...COMBINED WITH VERY STRONG SFC TO 850MB FGEN
FORCING...STEEP 1000-700MB LAPSE RATES...AND FAVORABLE SNOW GROWTH
POTENTIAL WL RESULT IN NUMEROUS SNOW SHOWERS. IN ADDITION...GFS
SHOWS DEEP LAYER UVVS MOVING FROM WEST TO EAST ACRS OUR CWA
ASSOCIATED WITH FRNT AND ULVL SUPPORT. THIS SETUP WL HAVE THE
POTENTIAL TO PRODUCE LOW END ADVISORY CRITERIA SNOWFALL AMOUNTS ON
MONDAY INTO MONDAY NITE ACRS THE MTN LOCATIONS. THINKING SNOWFALL
AMOUNTS ACRS DACKS/GREENS WL BE 3 TO 5 INCHES WITH 1 TO 3 INCHES IN
THE VALLEYS BY MONDAY NIGHT. THESE CONDITIONS WL CREATE A HAZARDOUS
EVENING COMMUTE ON MONDAY EVENING. TEMPS WL SHARPLY DROP LATE
MONDAY AFTN INTO MONDAY NIGHT WITH STRONG LLVL CAA DEVELOPING ON
BRISK NW WINDS. WE COULD SEE WIND CHILL HIGHLIGHTS MONDAY NITE INTO
TUES MORNING...BASED ON BELOW ZERO TEMPS AND BRISK NW WINDS OF 10 TO
20 MPH WITH HIGHER GUSTS.

&&

.EXTENDED FORECAST /12Z TUESDAY THROUGH SATURDAY/...
OPERATIONAL MODEL CONSENSUS IS FOR UNSEASONABLY LOW 1000-500MB
THICKNESS VALUES /488DM IN 12Z ECMWF VALID AT 12Z TUESDAY/ OVER THE
FORECAST AREA BEHIND ARCTIC FROPA ON MONDAY. GRADIENT FLOW REMAINS
MODERATELY STG FROM THE NORTH EAST OF SLOW MOVING SFC RIDGE ACROSS
THE GREAT LAKES...AND CURRENTLY ANTICIPATE DAYTIME WINDS 10-20KTS ON
TUESDAY...WITH HIGHS 5-15F /ABOUT 20F BELOW CLIMATOLOGY/. WIND
CHILLS OF 20 BELOW ARE POSSIBLE...ESPECIALLY TUESDAY MORNING. AIR
MASS APPEARS DRY...BUT LOW-LEVEL INSTABILITY AND DEEP-LAYER
NORTHWEST FLOW MAY BE SUFFICIENT FOR SCATTERED FLURRIES ABOVE 1500
FT ACROSS THE NORTH COUNTRY.

SFC RIDGE BUILDS CLOSER TO THE FA TUESDAY NIGHT...ALLOWING FOR
WIDESPREAD BELOW ZERO MINIMUM TEMPERATURES WITH PBL DECOUPLING
LIKELY. A FEW OF THE TYPICALLY COLDER SPOTS OF THE ADIRONDACKS
AND NERN VT COULD SEE READINGS IN THE TEENS BELOW ZERO EARLY
WEDNESDAY MORNING.

A SLOW MODERATING TEMPERATURE TREND DEVELOPS FROM WEDNESDAY THROUGH
FRIDAY...WITH APPROACH OF NEXT SIGNIFICANT FRONTAL SYSTEM EXPECTED
ON SATURDAY. THERMAL PROFILES APPEAR WARM ENOUGH AT THIS TIME TO
SUPPORT MAINLY RAIN SHOWERS WITH THIS SYSTEM FOR NEXT WEEKEND.

.AVIATION /20Z SATURDAY THROUGH 18Z SUNDAY/...
SCATTERED RAIN AND SNOW SHOWERS WILL CONTINUE ACROSS THE FORECAST
AREA WITH ISOLD VSBY DOWN TO 2SM THRU TONIGHT IN SHRASN. MODEL
SOUNDINGS CONTINUE TO INDICATE SHALLOW INSTABILITY WITHIN SFC TO
700MB LAYER...RESULTING IN CONVECTIVE CLOUD BANDS THIS
AFTN...GENERALLY ORIENTED PARALLEL TO DEEP-LAYER SW-NE SHEAR.
LOW-LEVEL FLOW REMAINS SWLY THROUGH 13Z TOMORROW...THEN VEERS INTO
THE NW. WITH VERTICALLY STACKED CYCLONE TRANSLATING THROUGH THE FA
OVERNIGHT TONIGHT...CONTINUED CHANCE OF SNOW SHOWERS WILL PERSIST
THROUGH THE OVERNIGHT HRS. HAVE KEPT PROB30 GROUP FOR -SHSN AT KSLK
AND KMSS BETWEEN 06Z AND 12Z.

&&

.CLIMATE...
SOME INTERESTING CLIMATE FACTS FOR BTV:
WE HAVE HAD AT LEAST 2.0 OF SNOW ON THE GROUND SINCE JAN 15TH. THE
MOST CONSECUTIVE DAYS WITH AT LEAST 1.0 OF SNOW ON THE GROUND IS
130 DAYS BACK IN 1970-71. IN ADDITION...OUR SEASON SNOWFALL AS OF
MIDNIGHT IS 69.0 INCHES...WHICH IS 6.5 INCHES ABOVE NORMAL. AS OF
1PM WE HIT 40F AT BTV...WHICH IS THE FIRST TIME ABOVE 40F SINCE JAN
13TH...WHEN THE TEMP REACHED 44F.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&

SYNOPSIS/CLIMATE...TABER
SHORT TERM...TABER
LONG TERM...BANACOS
AVIATION...BANACOS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BURLINGTON VT
538 AM EST SAT MAR 3 2007

NYZ026>031-034-035-087-VTZ001>012-016>019-041045-
NORTHERN ST. LAWRENCE-NORTHERN FRANKLIN-EASTERN CLINTON-
SOUTHEASTERN ST. LAWRENCE-SOUTHERN FRANKLIN-WESTERN CLINTON-
WESTERN ESSEX-EASTERN ESSEX-SOUTHWESTERN ST. LAWRENCE-GRAND ISLE-
WESTERN FRANKLIN-ORLEANS-ESSEX-WESTERN CHITTENDEN-LAMOILLE-
CALEDONIA-WASHINGTON-WESTERN ADDISON-ORANGE-WESTERN RUTLAND-
WINDSOR-EASTERN FRANKLIN-EASTERN CHITTENDEN-EASTERN ADDISON-
EASTERN RUTLAND-
538 AM EST SAT MAR 3 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHERN NEW
YORK...CENTRAL VERMONT...NORTHEAST VERMONT...NORTHWEST VERMONT
AND SOUTHERN VERMONT.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. SNOW SHOWERS WILL
BECOME NUMEROUS THIS AFTERNOON AND EVENING...BUT ANY ADDITIONAL
SNOW ACCUMULATIONS WILL BE ONLY A DUSTING TO 2 INCHES.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THERE IS A CHANCE OF SNOW SHOWERS ON SUNDAY. MORE NUMEROUS SNOW
SHOWERS ARE EXPECTED ON MONDAY AS AN ARCTIC FRONT MOVES THROUGH
THE AREA. OTHERWISE...NO HAZARDOUS WEATHER IS EXPECTED AT THIS
TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BURLINGTON VT
235 PM EST SAT MAR 3 2007

NYZ026>031-034-035-087-VTZ001>012-016>019-040400-
NORTHERN ST. LAWRENCE-NORTHERN FRANKLIN-EASTERN CLINTON-
SOUTHEASTERN ST. LAWRENCE-SOUTHERN FRANKLIN-WESTERN CLINTON-
WESTERN ESSEX-EASTERN ESSEX-SOUTHWESTERN ST. LAWRENCE-GRAND ISLE-
WESTERN FRANKLIN-ORLEANS-ESSEX-WESTERN CHITTENDEN-LAMOILLE-
CALEDONIA-WASHINGTON-WESTERN ADDISON-ORANGE-WESTERN RUTLAND-
WINDSOR-EASTERN FRANKLIN-EASTERN CHITTENDEN-EASTERN ADDISON-
EASTERN RUTLAND-
INCLUDING THE CITIES OF...MASSENA...MALONE...PLATTSBURGH...
STAR LAKE...SARANAC LAKE...TUPPER LAKE...DANNEMORA...
LAKE PLACID...PORT HENRY...TICONDEROGA...OGDENSBURG...POTSDAM...
GOUVERNEUR...ALBURGH...SOUTH HERO...ST. ALBANS...NEWPORT...
ISLAND POND...BURLINGTON...JOHNSON...STOWE...ST. JOHNSBURY...
MONTPELIER...MIDDLEBURY...VERGENNES...BRADFORD...RANDOLPH...
RUTLAND...SPRINGFIELD...WHITE RIVER JUNCTION...ENOSBURG FALLS...
RICHFORD...UNDERHILL...BRISTOL...RIPTON...EAST WALLINGFORD...
KILLINGTON
235 PM EST SAT MAR 3 2007

...THE DEVELOPMENT OF BLACK ICE MAY CAUSE SLICK SPOTS ON AREAS ROADWAYS AND SIDEWALKS
TONIGHT ACROSS THE NORTH COUNTRY...

THE COMBINATION OF YESTERDAYS SNOW STORM AND WARM TEMPERATURES
TODAY HAS CAUSED SOME SNOW TO MELT ACROSS THE REGION. IN
ADDITION...MANY STORM DRAINS HAVE BEEN CLOGGED WITH
SNOW...THEREFORE AREAS OF STANDING WATER HAS DEVELOPED ON ROADS AND
SIDEWALKS ACROSS THE REGION. AS TEMPERATURES DROP BELOW FREEZING
THIS EVENING EXPECT AREAS OF STANDING WATER TO FREEZE...CREATING
BLACK ICE AND SLICK SPOTS ON ROADWAYS AND SIDEWALKS. THESE AREAS
MAY BE DIFFICULT TO DETECT AND DRIVERS SHOULD USE CAUTION WHEN
DRIVING TONIGHT...ESPECIALLY ON UNTREATED ROAD SURFACES.

TABER