Mesoscale Discussion 2054

Issued

Dec 22, 2021, 10:26 AM EST (15:26 UTC)

Expired

Dec 22, 2021, 4:30 PM EST

In force

6 hr

Issued by

the Storm Prediction Center

Concerning

Heavy snow

Counties Aroostook County, ME, Piscataquis County, ME, Somerset County, ME

The Caribou radar (KCBW), 130 km from the middle of the area, began a volume at 15:32 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.

613 
ACUS11 KWNS 221527
SWOMCD
SPC MCD 221526 
MEZ000-222130-

Mesoscale Discussion 2054
NWS Storm Prediction Center Norman OK
0926 AM CST Wed Dec 22 2021

Areas affected...Portions of central and northern Maine

Concerning...Heavy snow 

Valid 221526Z - 222130Z

SUMMARY...Heavy snow with rates of 1-1.5 inches per hour are
expected in parts of northern and central Maine this afternoon.
Freezing rain is still possible, but should become more spatially
limited with time.

DISCUSSION...Areas of freezing rain have been ongoing across parts
of New Hampshire and into southern Maine. A zone of freezing rain is
likely to persist into this afternoon in Maine; however, this zone
should tend to become more narrow with time due to an increase in
low-level warm advection over the next several hours.

The primary area of more significant winter weather will shift
towards parts of central and northern Maine within the next two
hours or so. Regional radar imagery shows an area of precipitation
near the ME/NH border that will be shifting northeastward. The 12Z
CAR sounding showed a much colder temperature profile that will
support snow even as warm advection in the lowest 3 km increases.
The approaching trough will take on an a more negative tilt and
mid-level ascent will combine with 850 mb WAA to promote lift within
the dendritic growth zone. Snowfall rates of 1-1.5 inches per hour
are probable with some potential for locally higher rates as steep
lapse rates at cloud top could lead to some convective enhancement.
Snowfall is currently expected to increase by 12-1 pm EST and taper
off from west to east by 4-5 pm EST.

..Wendt.. 12/22/2021

...Please see www.spc.noaa.gov for graphic product...

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

LAT...LON   47066975 47566915 47276764 46606774 45456864 45096927
            45057004 45317057 45637086 45987080 47066975

Mesoscale Discussions in Maine, 2021Every mesoscale discussion in 2021

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.