Alert archive / Maine / Mesoscale Discussions in 2021

Mesoscale Discussion 56

February 2, 202113 counties in Maine

The Storm Prediction Center issued this mesoscale discussion at Feb 2, 2021, 4:46 PM EST for 13 counties in Maine. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Feb 2, 2021, 4:46 PM EST (21:46 UTC)
Expired
Feb 2, 2021, 8:45 PM EST
In force
4 hr
Issued by
the Storm Prediction Center
Concerning
Winter mixed precipitation

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

The radar

The Caribou radar (KCBW), 107 km from the middle of the area, began a volume at 21:48 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.

The nearest sounding before it

Caribou, ME (KCAR), launched 12:00Z, 9.8 hours before the alert went out and 172 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Caribou, ME at 12:00Z on 2021-02-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Caribou, ME at 12:00Z on 2021-02-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 210 square meters per square second.1939587897117136Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
908 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
210 m²/s²
0-3 km storm-relative helicity
194 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

706 
ACUS11 KWNS 022147
SWOMCD
SPC MCD 022146 
MEZ000-030145-

Mesoscale Discussion 0056
NWS Storm Prediction Center Norman OK
0346 PM CST Tue Feb 02 2021

Areas affected...Much of Maine

Concerning...Winter mixed precipitation 

Valid 022146Z - 030145Z

SUMMARY...Moderate to heavy snow is expected to persist for at least
a few more hours across northern ME, with a snow/sleet mix
persisting from central ME southward. Instances of 1 inch/hr
snowfall rates remain possible.

DISCUSSION...850 mb warm-air advection continues to overspread ME as
a low-level cyclone continues to advance north along the New England
coast. In addition, the 18Z GYX sounding indicates that at/above
freezing 850 mb temperatures have already reached inland. As such,
850 mb temperatures are expected to reach just above freezing across
portions of interior central/southern ME, suggesting that a
snow/sleet mix should persist. As evident in KCBW and KGYX
dual-polarimetric radar data, a snow/sleet mix is ongoing in two
distinct northward moving bands (one in Penobscot/Washington
Counties and another extending from Cumberland to Lincoln Counties).
As these bands continue northward into northern ME, snow is expected
to remain the main precipitation type, as 850 mb temperatures are
likely to remain sub-freezing, and instances of around 1 inch/hr
snowfall rates remain possible.

..Squitieri.. 02/02/2021

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

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

LAT...LON   44506799 43896907 43756951 43866994 44677088 45167096
            46067041 47176967 47596912 47356813 46966777 45926751
            45356721 45016727 44506799

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 1, 7:27 PM ESTMesoscale DiscussionSPCYork6 hr
Feb 2, 2:18 AM ESTMesoscale DiscussionSPCAndroscoggin, Aroostook, Franklin, Hancock, Kennebec, Oxford and 5 more6 hr
Feb 2, 10:52 AM ESTMesoscale DiscussionSPCAroostook, Hancock, Penobscot, Piscataquis, Washington6 hr

Nearby

Mesoscale Discussions in Maine, 2021Every mesoscale discussion in 2021

Sources

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.