Alert archive / Vermont / Mesoscale Discussions in 2022
Mesoscale Discussion 252
The Storm Prediction Center issued this mesoscale discussion at Mar 12, 2022, 1:38 PM EST for 5 counties in Maine; 4 counties in New Hampshire; 6 counties in Vermont. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 12, 2022, 1:38 PM EST (18:38 UTC)
- Expired
- Mar 12, 2022, 7:45 PM EST
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Heavy snow
Counties Aroostook County, ME, Franklin County, ME, Oxford County, ME, Piscataquis County, ME, Somerset County, ME, Carroll County, NH, Coos County, NH, Grafton County, NH, Sullivan County, NH, Caledonia County, VT, Essex County, VT, Orange County, VT, Orleans County, VT, Washington County, VT, Windsor County, VT
The radar
The Portland,ME radar (KGYX), 153 km from the middle of the area, began a volume at 18:37 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 12:00Z, 6.6 hours before the alert went out and 153 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
- 429 m above ground
- 0-6 km bulk shear
- 89 kt
- 0-1 km storm-relative helicity
- 464 m²/s²
- 0-3 km storm-relative helicity
- 601 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
078
ACUS11 KWNS 121838
SWOMCD
SPC MCD 121838
MEZ000-NHZ000-VTZ000-130045-
Mesoscale Discussion 0252
NWS Storm Prediction Center Norman OK
1238 PM CST Sat Mar 12 2022
Areas affected...Parts of Vermont...New Hampshire...and Maine
Concerning...Heavy snow
Valid 121838Z - 130045Z
SUMMARY...Heavy snow with rates of 1.0 to 1.5 inch/hour will
continue spreading northward across parts of New England through the
afternoon and evening.
DISCUSSION...Water vapor imagery depicts a large-scale trough moving
eastward across the Great Lakes and Ohio Valley, with a strong
downstream midlevel speed maximum overspreading the Northeast. As
the strengthening ascent within the exit region of the speed maximum
moves over progressively colder/deeper subfreezing temperatures,
heavy snowfall will develop northward across parts of Vermont, New
Hampshire, and Maine this afternoon and early evening.
Latest mesoanalysis suggests that a deep frontogenetic circulation
located along the northwestern periphery of a surface low just
offshore of MA will lift northward across New England over the next
several hours -- where increasing low-level cold air advection is
occurring. Here, forecast soundings show a deep/saturated dendritic
growth zone collocated with the increasing ascent, which should
support heavy snowfall rates of 1.0 to 1.5 inch/hour across parts of
VT, NH, and ME. These snowfall rates will also be aided by
strengthening upslope flow, and localized rates near 2.0 inch/hour
will be possible primarily over the higher terrain.
..Weinman.. 03/12/2022
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CAR...GYX...BTV...ALY...
LAT...LON 44796991 44117079 43177183 43137255 43737314 44467275
45237207 45827119 47616926 47546819 46976740 46586744
45766838 44796991SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 12, 8:53 AM EST | Mesoscale Discussion | SPC | Franklin, Oxford | 4 hr |
Nearby
Mesoscale Discussions in Vermont, 2022Mesoscale Discussions in Maine, 2022Mesoscale Discussions in New Hampshire, 2022Every mesoscale discussion in 2022
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.