Alert archive / Maine / Mesoscale Discussions in 2021
Mesoscale Discussion 55
The Storm Prediction Center issued this mesoscale discussion at Feb 2, 2021, 10:52 AM EST for 5 counties in Maine. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 2, 2021, 10:52 AM EST (15:52 UTC)
- Expired
- Feb 2, 2021, 4:45 PM EST
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Heavy snow
Counties Aroostook County, ME, Hancock County, ME, Penobscot County, ME, Piscataquis County, ME, Washington County, ME
The radar
The Caribou radar (KCBW), 48 km from the middle of the area, began a volume at 15:56 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, 3.9 hours before the alert went out and 105 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.
- 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
The text
As transmitted.
292
ACUS11 KWNS 021552
SWOMCD
SPC MCD 021552
MEZ000-022145-
Mesoscale Discussion 0055
NWS Storm Prediction Center Norman OK
0952 AM CST Tue Feb 02 2021
Areas affected...parts of northern and eastern Maine
Concerning...Heavy snow
Valid 021552Z - 022145Z
SUMMARY...Heavier snowfall rates are expected to develop through
midday, with 1 to 1.5 inch/hr rates possible.
DISCUSSION...A gradually deepening surface low is approaching
portions of Maine from the south, with an 850-700 mb low gradually
drifting north along the Mid-Atlantic/southern New England seaboard.
In advance of the 850-700 mb low, a warm conveyor belt and
associated near saturated airmass is beginning to overspread
portions of ME per latest Mesoanalysis. KCBW dual polarimetric radar
data shows a heavier band of wintry mixed precipitation occurring
across Washington County, and this band is expected to track
northwestward through the day.
As the low to mid-levels of the troposphere continue to warm and
moisten across east-central into northern Maine, saturation of the
dendritic growth zone (as shown by the latest RAP forecast
soundings) is expected to promote higher snowfall rates. 12Z HREF
guidance suggests that some areas may see up to 1 to 1.5 inch/hr
rates in the 17-22Z period, particularly where the 925-700 mb layer,
despite warming, can remain below freezing.
..Squitieri.. 02/02/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CAR...GYX...
LAT...LON 46806777 47076776 47286808 47376857 47416891 47426926
47136963 46627001 46247001 45996983 45056929 44386863
44196832 44226816 44506730 44726703 45056713 45436742
45786765 46806777SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 1, 7:27 PM EST | Mesoscale Discussion | SPC | York | 6 hr |
| Feb 2, 2:18 AM EST | Mesoscale Discussion | SPC | Androscoggin, Aroostook, Franklin, Hancock, Kennebec, Oxford and 5 more | 6 hr |
| Feb 2, 4:46 PM EST | Mesoscale Discussion | SPC | Androscoggin, Aroostook, Franklin, Hancock, Kennebec, Knox and 7 more | 4 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.