Mesoscale Discussion 2242

Issued

Dec 27, 2012, 3:52 AM EST (08:52 UTC)

Expired

Dec 27, 2012, 9:45 AM EST

In force

6 hr

Issued by

the Storm Prediction Center

Counties Androscoggin County, ME, Cumberland County, ME, Franklin County, ME, Hancock County, ME, Kennebec County, ME, Oxford County, ME, Penobscot County, ME, Somerset County, ME, Waldo County, ME, York County, ME, Carroll County, NH, Coos County, NH, Strafford County, NH

The Portland,ME radar (KGYX), 92 km from the middle of the area, began a volume at 08:51 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

501 
ACUS11 KWNS 270852
SWOMCD
SPC MCD 270852 
MEZ000-NHZ000-271445-

MESOSCALE DISCUSSION 2242
NWS STORM PREDICTION CENTER NORMAN OK
0252 AM CST THU DEC 27 2012

AREAS AFFECTED...EASTERN NH AND WESTERN/CNTRL MAINE

CONCERNING...HEAVY SNOW 

VALID 270852Z - 271445Z

SUMMARY...SNOWFALL RATES WILL INCREASE TO 1 TO LOCALLY 2 INCHES AN
HOUR BY 12Z. HEAVY SNOW WILL CONTINUE THROUGH MUCH OF THE DAY. SNOW
ALONG THE COAST MAY TRANSITION TO A RAIN/SNOW MIX OR ALL RAIN AFTER
12Z AS TEMPERATURES WARM INTO THE MID 30S. GUSTY WINDS WILL LEAD TO
BLOWING AND DRIFTING OF SNOW AND REDUCED VISIBILITIES.

DISCUSSION...A SFC LOW LOCATED SOUTH OF LONG ISLAND EARLY THIS
MORNING WILL CONTINUE TRACKING NEWD ALONG THE SOUTHERN NEW ENGLAND
COAST. MEANWHILE...NEGATIVELY TILTED MID AND UPPER LEVEL TROUGH WILL
ALSO PIVOT NEWD FROM THE MID ATLANTIC COAST ACROSS NEW ENGLAND. THIS
WILL MAINTAIN FAVORABLE POSITION OF WARM CONVEYOR BELT ACROSS SRN
AND CNTRL MAINE FOR MOST OF THE DAY. 8Z MESOANALYSIS INDICATED BAND
OF 700 MB FRONTOGENESIS STRETCHING ACROSS DOWNSTATE MAINE. AS LARGE
SCALE ASCENT ASSOCIATED WITH UPPER WAVE BEGINS TO MOVE ACROSS THIS
SAME REGION...STRONG VERTICAL ASCENT THROUGH DEEP SATURATED SUB-ZERO
COLUMN WILL LEAD TO HEAVY SNOWFALL. MODERATE SNOW WAS BEING REPORTED
FROM SFM IN MAINE TO NORTHEAST NH AND WILL CONTINUE TO SPREAD NORTH
AND EAST ACROSS MAINE THE NEXT SEVERAL HOURS. SNOWFALL RATES WILL
INCREASE TO 1 INCH TO LOCALLY 2 INCHES AN HOUR BY 12Z AND CONTINUE
THROUGH THE DAY. ADDITIONALLY...AS THE SFC LOW APPROACHES...WIND
SPEEDS WILL INCREASE TO AROUND 20 MPH WITH GUSTING OVER 30
MPH...RESULTING IN BLOWING AND DRIFTING SNOW. 

WHILE SNOW MAY INITIALLY OCCUR ALONG THE COAST...WARMING
TEMPERATURES WILL LEAD TO A RAIN/SNOW MIX OR TRANSITION TO ALL RAIN
AFTER 12Z.

..LEITMAN.. 12/27/2012

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

ATTN...WFO...CAR...GYX...

LAT...LON   43906996 43297062 43217093 43247109 43587148 44587144
            45127145 45307121 45417088 45627068 46027040 46086984
            45916920 45676865 45306808 44866781 44556784 44386824
            44146896 44116915 43906996

Mesoscale Discussions in Maine, 2012Mesoscale Discussions in New Hampshire, 2012Every mesoscale discussion in 2012

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.