Winter Storm in Massachusetts, December 25 to 26, 2002

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ALBANY NY
1040 AM EST WED DEC 25 2002

.CURRENT...MAX FRONTOGEN FM RUC40 CORRELATES VERY WELL WITH RAPID
INCREASE IN WSR88D RETURNS ACRS NEPA AND NJ. ALIGNS WELL WITH
DEFORMATION AXIS AND ORIENTATION TO H700 MB HPA AND 300 HPA JET
COUPLING AS PER RECENT CSTAR BANDING CONCEPTUAL MODEL. IN TERMS OF
SENSIBLE WEATHER THIS WILL PROD FISRT SURGE OF HEAVY SNOW...LIFTING
ACRS CATSKILLS 17-18Z TOWARD ALBANY EARLY THIS AFTERNOON. AXIS SHLD
MV TO ALY AREA 18Z. WL ISSUE STRONGLY WORDED NOWCAST SNOW INCR TO
1-2 HR THEN 2-4/HR

SNYDER

.PVS DISC...

THE CURRENT WEATHER SITUATION IS ABOUT AS CLOSE TO PERFECT AS IT
GETS FOR ANTECEDENT AND MODEL FORECAST PARAMETERS TO SPILL A LOT OF
SNOW ACROSS MUCH OF ALBANYS COUNTY WARNING AREA.  THE LATEST RUN OF
THE MODELS (0000 UTC WEDNESDAY), POINTS TO A HEAVY SNOWFALL IN THE
BULK OF THE COUNTY WARNING AREA.  THE ONLY AREA OF CONCERN IS THE
NORTHWESTERN PERIPHERY OF THE COUNTY WARNING AREA (WESTERN MOHAWK
VALLEY AND WESTERN ADIRONDACKS).  THE ETA, MESOSCALE ETA, AVIATION
AND CANADIAN REGIONAL MODEL WERE EXAMINED PRIOR TO THIS DISCUSSION.
THE MAIN DIFFERENCE BETWEEN THE MODELS IS IN THE FORECAST AREA OF
MAXIMUM PRECIPITATION AND THE PLACEMENT AND DEPTH OF THE SURFACE
LOW.  THE MULTI-LEVEL WIND CIRCULATION FORECAST SUGGEST A HIGH
PROBABILITY OF HEAVY BANDED PRECIPITATION WITH THIS STORM.  IT IS
UNLIKELY THAT THE AVIATION, WITH ITS POORER RESOLUTION IS CAPTURING
THIS.  HOWEVER, IT IS STRONGLY SUGGESTED BY THE PRECIPITATION
FORECAST OF THE MESOSCALE ETA WHICH INDICATES A RELATIVELY NARROW
BAND OF HEAVY PRECIPITATION ACROSS THE NORTHERN CATSKILLS, CAPITAL
DISTRICT INTO SOUTHERN VERMONT, THE NORTHERN TACONICS AND THE
BERKSHIRES.  THE AVIATION MODEL SUGGESTS THAT THE AXIS OF HEAVIEST
PRECIPITATION WILL BE ALONG THE ATLANTIC COAST, AND INDEED, THIS
MODEL DOES FORECAST THE LOW PRESSURE CENTER TO BE FURTHER TO THE
SOUTH THAN THE MESOSCALE ETA, AND ALSO 5 OR 6 MILLIBARS DEEPER.  THE
AVIATION MODEL REALLY LOOSES ITS MARBLES BETWEEN 1200 UTC AND 1800
UTC TODAY WHEN IT DEEPENS AND 12 MILLIBARS.  THE MESOSCALE ETA AND
CANADIAN REGIONAL ARE CLOSE BEHIND DROPPING THE CENTER BY 10
MILLIBARS.  THE CANADIAN MODELS PRECIPITATION FORECAST IS NOT AS
STRONGLY SUGGESTIVE OF BANDED PRECIPITATION AS THE MESOSCALE ETA,
BUT THEN AGAIN, ALL WE HAVE TO WORK WITH IS INTERNET MAPS, DIVIDED
INTO CHUNKS OF 6-HOUR TIME PERIODS (MAYBE SOMEDAY WELL HAVE THE
LUXURY OF LOOKING AT THIS MODEL IN AWIPS).  BUT THIS MODEL IS
INDICATING VERY HEAVY PRECIPITATION SOMEWHAT TO THE SOUTH OF THE
MESOSCALE ETA FORECAST (ACROSS THE CENTRAL AND SOUTHERN CATSKILLS
AND MID HUDSON VALLEY INTO THE BERKSHIRES, WHERE AND INCH OR MORE IS
FORECAST BETWEEN 1800 UTC WEDNESDAY AND 0000 UTC THURSDAY.  WE
BELIEVE THAT THE MESOSCALE ETA AND CANADIAN MODELS HAVE THE BEST
HANDLE ON WHERE THE HEAVY PRECIPITATION WILL BE OCCURRING IN THIS
STORM.  THE DEPTH OF THE LOW FORECAST BY THE CANADIAN REGIONAL MODEL
IS SLIGHTLY DEEPER THAN THE MESOSCALE ETA, BUT NOT AS DEEP AS THE
AVIATION.  THE TRACK OF THE LOW IS VERY SIMILAR TO THE MESOSCALE
ETA, AND BOTH MODELS ARE FURTHER NORTH THAN THE AVIATION.  THE
THREAT OF DIMINISHED SNOWFALL IN THE EXTREME SOUTHEASTERN PORTION OF
THE COUNTY WARNING AREA IS NOW LESS THAN IT APPEARED TO BE ON MONDAY
NIGHTS MODEL FORECASTS.  BOTH THE MESOSCALE ETA AND THE CANADIAN
MODELS HAVE TRENDED COLDER.  MESOSCALE ETA FORECAST SOUNDINGS ARE
NOW SUGGESTING THAT THE ENTIRE SOUTHERN TIER OF ZONES IN ALBANYS
COUNTY WARNING AREA WILL REMAIN BELOW FREEZING THROUGH THE ENTIRE
COLUMN.  THE CANADIAN MODELS 850 MILLIBAR TO 700 MILLIBAR THICKNESS
IS SHOWING THE 1540 METER ISOPLETH TO BE INTO CENTRAL DUTCHESS AND
LITCHFIELD COUNTIES THIS MORNING AND EARLY THIS AFTERNOON, BUT THE
ABOVE FREEZING LAYER REMAINS SOUTHWEST OF THE COUNTY WARNING AREA
EARLY TODAY, AND THEN GETS WIPED OUT ENTIRELY THIS AFTERNOON.  THIS
SUGGESTS THAT VERY STRONG UPWARD MOTION AND HEAVY PRECIPITATION IN
THE FORM OF SNOW IS COOLING THE COLUMN TO BELOW FREEZING IN THE
ELEVATED ABOVE FREEZING LAYER.  SO, IT IS UNLIKELY THAT THERE WILL
BE ANY SLEET IN THE SOUTHERN ZONES TODAY, AND IT IS LIKELY THAT
SLEET WILL NOT BE MENTIONED IN THE FORECAST THAT IS RELEASED LATER
THIS MORNING.  THE CURRENT ZONE FORECASTS LOOK FINE OVERALL.  THE
MAIN CONCERN IS THAT THE PRECIPITATION IN THE NORTHWEST WILL NOT BE
HEAVY ENOUGH TO RESULT IN 7 INCHES OF SNOW.  HOWEVER, THIS IS THE
REGION WHEN THE AIR IS COLDEST, AND PERHAPS THE LIQUID TO SNOW RATIO
WILL BE GREATEST THERE.  ALSO, THERE IS THE OROGRAPHIC ENHANCEMENT
TO CONSIDER, SO THE WINTER STORM WARNING WILL BE LEFT IN PLACE IN
ALL ZONES.  THE LOWS EASTWARD MOVEMENT IS FORECAST TO SLOW BETWEEN
0000 UTC AND 0600 UTC THURSDAY BY THE CANADIAN MODEL.  AND THE
MESOSCALE ETA IS FORECASTING 90 PERCENT OR BETTER RELATIVE HUMIDITY
THROUGH 700 MILLIBARS THROUGH MUCH OF THE NIGHT WITH SOME UPWARD
MOTION.  TRADITIONALLY, THE BERKSHIRES, TACONICS AND SOUTHERN GREEN
MOUNTAINS PICK UP CONSIDERABLE TRIMMINGS ON THE BACKSIDE OF THESE
COASTAL STORMS, AND IT IS BELIEVED THAT THIS WILL BE THE CASE
TONIGHT AS WELL.  SO, WARNING CRITERION IS EXPECTED TO BE MET TO THE
EAST OF THE CAPITAL DISTRICT TONIGHT WITH AT LEAST ANOTHER 7 INCHES
OF SNOW, WHILE TO THE WEST, ITS LIKELY TO BE LESS.  THE WARNING
WILL BE CONTINUED INTO TONIGHT IN ALL ZONES.  TODAYS HIGH
TEMPERATURES WILL BE BELOW FREEZING IN ALL LOCATIONS, AND PROBABLY
AT LEAST 5 DEGREES BELOW FREEZING IN MOST ZONES.  TONIGHTS LOWS MAY
BE 5 OR 10 DEGREES LOWER, BUT THERE WONT BE A LOT OF COLD ADVECTION
AT THE SURFACE AND MINIMAL RADIATIONAL COOLING.  THE AVIATION-BASED
STATISTICAL FORECAST LOOKS TOO HIGH FOR TODAYS TEMPERATURES, BUT
ABOUT RIGHT ON THURSDAY.  THE NESTED-GRID FORECAST SEEMS BETTER FOR
TODAY.  A WINTER WEATHER EXPERIMENTAL CHAT IS SCHEDULED FOR 1245 AM,
WHICH ALBANYS OFFICE WILL PARTICIPATE IN.  ANY CHANGES FROM WHAT
THIS DISCUSSION INDICATES ARE LIKELY TO RESULT FROM THAT CHAT.  IF
THERE ARE ANY SIGNIFICANT CHANGES, ANOTHER DISCUSSION WILL BE ISSUED
BEFORE RELEASING THE FORECAST LATER THIS MORNING.  HOPE YOURE
GETTING A NEW SNOWBLOWER FOR A HOLIDAY GIFT.

.HYDROLOGICAL STATUS...WITH ONLY WINTER-TYPE PRECIPITATION IN THE
CARDS, NO PROBLEMS THROUGH THE END OF THE WEEK.

.ALY...WINTER STORM WARNINGS FOR THE ENTIRE COUNTY WARNING AREA
CHRISTMAS AND WEDNESDAY NIGHT.

CTZ001-MAZ001-NYZ032-033-038>043-047>054-058>061-063>066-VTZ013-014-
251045-

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE ALBANY NY
410 AM EST WED DEC 25 2002

...CORRECTED FOR MINOR TYPING ERROR...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN NEW YORK AND ADJACENT
WESTERN NEW ENGLAND.

.DAY ONE...TODAY
A POWERFUL NORTHEASTER SNOWSTORM WILL BRING 1 TO 2 FEET OF SNOW TO
MUCH OF EASTERN NEW YORK AND WESTERN NEW ENGLAND BY THE TIME IT
TAPERS OFF TONIGHT.  THE HEAVIEST SNOW IS LIKELY TO FALL SOUTH OF
THE EASTERN MOHAWK VALLEY AND LAKE GEORGE AREA.  AMOUNTS IN THE
WESTERN ADIRONDACKS MAY AVERAGE AROUND HALF A FOOT.  OVER TWO FEET
IS POSSIBLE IN THIS STORM IN SOME OF THE MORE HIGHLY ELEVATED AREAS
IN THE CATSKILLS...BERKSHIRES...TACONICS...AND SOUTHERN GREEN
MOUNTAINS.

.DAYS TWO THOUGH SEVEN...
NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER ACTIVATION IS REQUESTED FOR TODAY AND TONIGHT.

FOR ADDITIONAL WEATHER INFORMATION AND MORE DETAIL...VISIT US ON THE
WEB AT WWW.WEATHER.GOV. FROM THERE YOU CAN CLICK ON THE AREA YOU ARE
INTERESTED IN...AND VISIT THE LOCAL FORECAST OFFICE IN THAT AREA.

STAY TUNED TO NOAA WEATHER RADIO...THE VOICE OF THE NATIONAL WEATHER
SERVICE...FOR FURTHER DETAILS OR UPDATES.

HEMMERICH