Mesoscale Discussion 2113

Issued

Dec 29, 2015, 4:47 AM EST (09:47 UTC)

Expired

Dec 29, 2015, 10:45 AM EST

In force

6 hr

Issued by

the Storm Prediction Center

Counties Androscoggin County, ME, Aroostook County, ME, Cumberland County, ME, Franklin County, ME, Hancock County, ME, Kennebec County, ME, Knox County, ME, Lincoln County, ME, Oxford County, ME, Penobscot County, ME, Piscataquis County, ME, Sagadahoc County, ME, Somerset County, ME, Waldo County, ME, Washington County, ME

The Caribou radar (KCBW), 133 km from the middle of the area, began a volume at 09:44 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.

946 
ACUS11 KWNS 290948
SWOMCD
SPC MCD 290947 
MEZ000-291545-

MESOSCALE DISCUSSION 2113
NWS STORM PREDICTION CENTER NORMAN OK
0347 AM CST TUE DEC 29 2015

AREAS AFFECTED...MUCH OF MAINE

CONCERNING...HEAVY SNOW 

VALID 290947Z - 291545Z

SUMMARY...HEAVY SNOW WILL OVERSPREAD MUCH OF MAINE DURING THE
PRE-DAWN AND EARLY-MORNING HOURS...AND CONTINUE THROUGH THE MORNING.
SNOWFALL RATES OF 1-2 INCHES PER HOUR WILL BE LIKELY...AND RATES
COULD LOCALLY EXCEED 2 INCHES PER HOUR. AREAS OF SLEET WILL LIKELY
DEVELOP NWD THROUGH PARTS OF SRN MAINE DURING THE MORNING HOURS...AS
WELL.

DISCUSSION...SNOW WILL INCREASE IN COVERAGE AND INTENSITY ACROSS
MUCH OF MAINE DURING THE PRE-DAWN/EARLY-MORNING HOURS...SPREADING
FROM WSW TO ENE...WITH HEAVY SNOW BECOMING COMMON IN THE 11Z-15Z
TIME FRAME. MOSAIC RADAR LOOPS INDICATE A WIDESPREAD SHIELD OF
PRECIPITATION SPREADING ENEWD...EXTENDING FROM THE MID-ATLANTIC TO
CNTRL/SRN NEW ENGLAND. THIS ACTIVITY IS ASSOCIATED WITH THE
WARM-CONVEYOR STRUCTURE WELL E OF A COMPACT MID-LEVEL CYCLONE
CROSSING THE GREAT LAKES AREA. AS ASSOCIATED DEEP AND STRONG
FRONTOGENETIC CIRCULATIONS CROSS MAINE...AND RELATED ASCENT
INTERSECTS DEEP DENDRITIC GROWTH ZONES...HEAVY SNOW IS ANTICIPATED.
SNOWFALL RATES OF 1-2 INCHES PER HOUR WILL BE LIKELY. 

THE MOST HEAVY-SNOW-FAVORABLE OVERLAP OF RICHER DEEP MOISTURE AND
STRONG DEEP ASCENT AMIDST DEEP SUB-FREEZING AIR IS EXPECTED ACROSS
PARTS OF CNTRL MAINE -- ESPECIALLY FROM THE AUGUSTA AREA ENEWD
THROUGH THE BANGOR AREA TOWARD BAR HARBOR AND HOULTON. THIS IS WHERE
SNOWFALL RATES IN EXCESS OF 2 INCHES PER HOUR WILL BE POSSIBLE THIS
MORNING.

HEAVY SNOW WILL LIKELY CONTINUE ACROSS MUCH OF THE AREA THROUGH THE
MORNING HOURS. HOWEVER...ELEVATED WARM ADVECTION AND RELATED PARTIAL
MELTING OF DESCENDING HYDROMETEORS /REFREEZING WITHIN THE UNDERLYING
SUB-FREEZING PBL/ WILL HAVE THE POTENTIAL TO SUPPORT SLEET ACROSS
PARTS OF SRN MAINE INCLUDING THE PORTLAND AREA LATER THIS
MORNING...PARTICULARLY AROUND/AFTER THE 15Z-16Z TIME FRAME.
SLEET-ACCUMULATION RATES AROUND ONE-QUARTER INCH PER HOUR -- LOCALLY
HIGHER -- MAY ACCOMPANY THIS ACTIVITY...WITH THE POTENTIAL FOR SLEET
DEVELOPING NWD ACROSS PARTS OF SRN MAINE.

..COHEN.. 12/29/2015

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

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

LAT...LON   44536750 43636999 43317055 44287091 45277094 45877036
            46806981 47136890 46806788 45846772 44926701 44536750

Mesoscale Discussions in Maine, 2015Every mesoscale discussion in 2015

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.