241
ACUS11 KWNS 092007
SWOMCD
SPC MCD 092007
NHZ000-VTZ000-NYZ000-100200-
MESOSCALE DISCUSSION 2253
NWS STORM PREDICTION CENTER NORMAN OK
0207 PM CST MON DEC 09 2024
AREAS AFFECTED...PORTIONS OF EASTERN NEW YORK INTO VERMONT AND NEW
HAMPSHIRE
CONCERNING...WINTER MIXED PRECIPITATION
VALID 092007Z - 100200Z
SUMMARY...WINTRY MIXED PRECIPITATION IS POSSIBLE THROUGH THE
AFTERNOON AND EVENING HOURS ACROSS PORTIONS OF EASTERN NY INTO
PORTIONS OF NEW ENGLAND. FREEZING RAIN AND PERHAPS A BIT OF SLEET
APPEARS LIKELY OVER LOWER-TERRAIN AREAS, WITH SNOW (PERHAPS UP TO 1
INCH/HR RATES) OVER THE HIGHER TERRAIN.
DISCUSSION...A BROAD PRECIPITATION SHIELD IS APPROACHING PORTIONS OF
NEW ENGLAND FROM THE SOUTHWEST, DRIVEN BY APPRECIABLE LOW-LEVEL
WARM-AIR AND MOISTURE ADVECTION. THE APPROACH OF A PRONOUNCED
MID-LEVEL TROUGH, IN TANDEM WITH LOW-LEVEL LEE TROUGHING, WILL
ENCOURAGE CONTINUED STRONG DEEP-LAYER ACCENT, WHICH WILL IN TURN
FAVOR THE MAINTENANCE OF THE ONGOING PRECIPITATION BAND.
FURTHERMORE, THIS BAND IS APPROACHING A TROPOSPHERIC AIRMASS THAT IS
LARGELY SUB-FREEZING JUST ABOVE THE SURFACE (PER 20Z MESOANALYSIS).
WINTRY PRECIPITATION IS UNDERWAY, EVIDENT VIA BRIGHT-BANDING IN MRMS
MOSAIC RADAR IMAGERY, ZDR/CORRELATION COEFFICIENT TRANSITIONS WITH
KENX REGIONAL RADAR DATA, AND THE KGFL ASOS REPORTING MODERATE SNOW.
RAP FORECAST SOUNDINGS SHOW NEAR-SATURATED VERTICAL PROFILES, WITH
925-800 MB TEMPERATURES HOVERING AROUND THE FREEZING MARK. HOWEVER,
CURRENT SURFACE OBSERVATIONS SHOW WET BULB TEMPERATURES AROUND OR
JUST BELOW FREEZING. AS SUCH, EVAPORATION WITH THE ONSET OF
PRECIPITATION WITHIN THE COLUMN SHOULD SUPPORT ENOUGH COOLING TO
POTENTIALLY PROMOTE A RAIN/FREEZING RAIN/SLEET MIX OVER THE LOWER
ELEVATIONS. IN THE HIGHER ELEVATIONS, WINTRY MIX, DOMINATED BY SNOW,
APPEARS MOST LIKELY. GIVEN A SATURATED VERTICAL PROFILE, WITH STRONG
700 MB FRONTOGENESIS (DRIVEN BY A WELL-DEFINED 700 MB IMPULSE
OVERSPREADING THE NORTHEAST) A FEW INSTANCES OF HEAVIER SNOWFALL ARE
POSSIBLE. UP TO 1 INCH/HR SNOWFALL RATES CANNOT BE RULED OUT.
..SQUITIERI.. 12/09/2024
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...GYX...BTV...ALY...
LAT...LON 43407141 43157180 42977267 43037318 43257385 43327397
43747404 44327396 44607323 44567192 44237131 43837113
43407141
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page