[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 230057
SWOMCD
SPC MCD 230057 
MAZ000-MEZ000-NHZ000-RIZ000-CTZ000-NYZ000-VTZ000-230600-

MESOSCALE DISCUSSION 0118
NWS STORM PREDICTION CENTER NORMAN OK
0657 PM CST SAT JAN 22 2005

AREAS AFFECTED...MA/SRN VT/SRN NH/CT/RI/FAR SW ME AND NYC METRO

CONCERNING...HEAVY SNOW/BLIZZARD CONDITIONS 

VALID 230057Z - 230600Z

HEAVY SNOW WILL CONTINUALLY INCREASE THIS EVENING ACROSS MA/SRN
NH/SRN VT/CT/RI/FAR SW ME. HOURLY RATES OF 1.0-1.5 IN/HR WILL BE
COMMON EARLY THIS EVENING...WITH RATES AS HIGH AS 3.0 IN/HR
DEVELOPING BETWEEN 03Z-06Z ALONG AND SE OF BDL-BOS AXIS.
ADDITIONALLY...NELY WINDS WILL INCREASE INTO THE OVERNIGHT AS
PRESSURE GRADIENT TIGHTENS...WITH BLIZZARD CONDITIONS AND
SIGNIFICANT BLOWING/DRIFTING SNOW.

AS UPPER TROUGH RACES EWD OVER THE NRN APPALACHIANS...JET EXIT
REGION ASSOCIATED UPPER DIV COUPLED WITH INTENSE LOW-MID LEVEL WAA 
WILL CONTRIBUTE TO INTENSIFYING SNOWFALL ACROSS SRN NEW ENGLAND
THROUGH 06Z. SFC LOW CONTINUES TO DEEPEN OFF THE VA/DE COAST...WITH
ESTIMATED 999 MB LOW PER NEAR-SHORE OBS/OCEAN BUOYS AT 00Z.
NUMERICAL GUIDANCE SUGGESTS SFC LOW WILL CONTINUALLY DEEPEN/PROGRESS
NEWD TO AROUND 50-75 MILES OFF THE ERN LONG ISLAND COAST BY 06Z.

AS BAROCLINIC ZONE TIGHTENS IN NRN QUADRANT OF CYCLONE...21Z RUC
DIAGNOSTICS PORTRAY INCREASING MID LEVEL /800 MB-600 MB/
FRONTOGENETICAL FORCING OVER SRN ENGLAND BETWEEN 03Z-06Z...WITH
ELEVATED EPV REDUCTION ZONE OVER THE ADJACENT COASTAL WATERS. THIS
IS CONSISTENT WITH ELEVATED POTENTIAL INSTABILITY IN 00Z WAL RAOB
AND OBSERVED CG LIGHTNING EARLY THIS EVENING. IN PRESENCE OF WEAK
STATIC STABILITY...POTENTIAL FOR ENHANCED WEST-EAST ORIENTED
MESOSCALE BANDING WILL PROGRESSIVELY EXIST TOWARD 06Z /CONTINUING
OVERNIGHT/. GIVEN ARCTIC AIRMASS IN PLACE...SNOW TO LIQUID WATER
RATIOS OF 20:1 OR GREATER WILL CONTRIBUTE TO SNOW EFFICIENCY.

ADDITIONALLY...21Z RUC SUGGESTS ELY 850 MB WINDS INCREASING TO 50
KTS OR GREATER ACROSS SRN NEW ENGLAND BY 06Z...HEIGHTENING BLIZZARD
CONDITIONS AND BLOWING/DRIFTING SNOW.

..GUYER.. 01/23/2005

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...GYX...BOX...BTV...OKX...ALY...

42076983 41357001 40967174 40897237 40847362 40987383
42197325 43087276 43677166 43687094 43467044 42677015 

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