Alert archive / Maine / Mesoscale Discussions in 2021
Mesoscale Discussion 2053
The Storm Prediction Center issued this mesoscale discussion at Dec 22, 2021, 4:26 AM EST for 7 counties in Maine; Hampden County, Middlesex County, Worcester County, Massachusetts; 6 counties in New Hampshire. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 22, 2021, 4:26 AM EST (09:26 UTC)
- Expired
- Dec 22, 2021, 8:30 AM EST
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Freezing rain
Counties Hampden County, MA, Middlesex County, MA, Worcester County, MA, Androscoggin County, ME, Cumberland County, ME, Kennebec County, ME, Lincoln County, ME, Sagadahoc County, ME, Waldo County, ME, York County, ME, Belknap County, NH, Carroll County, NH, Hillsborough County, NH, Merrimack County, NH, Rockingham County, NH, Strafford County, NH
The radar
The Portland,ME radar (KGYX), 50 km from the middle of the area, began a volume at 09:27 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
Gray, ME (KGYX), launched 00:00Z, 9.4 hours before the alert went out and 49 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
- 1191 m above ground
- 0-6 km bulk shear
- 74 kt
- 0-1 km storm-relative helicity
- 54 m²/s²
- 0-3 km storm-relative helicity
- 198 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
633
ACUS11 KWNS 220927
SWOMCD
SPC MCD 220926
MEZ000-MAZ000-NHZ000-221330-
Mesoscale Discussion 2053
NWS Storm Prediction Center Norman OK
0326 AM CST Wed Dec 22 2021
Areas affected...Central MA...Southern NH...Southern ME
Concerning...Freezing rain
Valid 220926Z - 221330Z
SUMMARY...Light freezing rain across MA and NH will continue for the
next few hours while also spreading northeastward into more of
southwest ME.
DISCUSSION...Numerous surface observations from central MA and
southern NH have begun reporting freezing rain over the past hour as
light precipitation within the broad warm conveyor extending from
southern New England into southern ME. This precipitation is
occurring over an area where surface temperatures are in the upper
20s/low 30s below a modest inversion, with temperatures above
freezing in the 1000 to 850 mb layer. Warm air advection will
contribute to gradually warming surface temperatures, evidenced by
current temperature trends across MA and NH. This warming should
eventually push surface temperatures above freezing, but not before
a few hours of light freezing rain.
The light precipitation is just reaching areas farther north
(southwest ME), which should begin experiencing freezing rain soon.
In this area, the freezing rain will likely continue for the next
several hours.
..Mosier.. 12/22/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CAR...GYX...BOX...
LAT...LON 43477178 44097100 44726977 44826917 44356887 43956954
42937082 42147172 42077281 43477178SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 22, 10:26 AM EST | Mesoscale Discussion | SPC | Aroostook, Piscataquis, Somerset | 6 hr |
Nearby
Mesoscale Discussions in Maine, 2021Mesoscale Discussions in New Hampshire, 2021Mesoscale Discussions in Massachusetts, 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.