Alert archive / Maine / Mesoscale Discussions in 2011
Mesoscale Discussion 142
The Storm Prediction Center issued this mesoscale discussion at Feb 25, 2011, 12:36 PM EST for 9 counties in Maine; 5 counties in New Hampshire; Orange County, Windsor County, Vermont. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 25, 2011, 12:36 PM EST (17:36 UTC)
- Expired
- Feb 25, 2011, 4:30 PM EST
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
Counties Androscoggin County, ME, Cumberland County, ME, Franklin County, ME, Hancock County, ME, Kennebec County, ME, Oxford County, ME, Penobscot County, ME, Waldo County, ME, Washington County, ME, Belknap County, NH, Carroll County, NH, Grafton County, NH, Merrimack County, NH, Sullivan County, NH, Orange County, VT, Windsor County, VT
The radar
The Portland,ME radar (KGYX), 82 km from the middle of the area, began a volume at 17:40 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, 5.6 hours before the alert went out and 82 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
- 1396 m above ground
- 0-6 km bulk shear
- 78 kt
- 0-1 km storm-relative helicity
- 56 m²/s²
- 0-3 km storm-relative helicity
- 162 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
075
ACUS11 KWNS 251737
SWOMCD
SPC MCD 251736
MEZ000-NHZ000-VTZ000-252130-
MESOSCALE DISCUSSION 0142
NWS STORM PREDICTION CENTER NORMAN OK
1136 AM CST FRI FEB 25 2011
AREAS AFFECTED...E-CNTRL VT / CNTRL NH / LARGE PART OF THE SERN HALF
OF MAINE
CONCERNING...HEAVY SNOW
VALID 251736Z - 252130Z
HEAVY SNOWFALL RATES EXCEEDING 1 INCH PER HOUR THIS AFTERNOON WILL
LIKELY OCCUR FROM PORTIONS OF E-CNTRL VT NEWD INTO ERN MAINE. A
CHANGEOVER FROM SNOW TO MIXED P-TYPE IS POSSIBLE ALONG COASTAL
MAINE.
MIDDAY WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL WAVE PROGRESSING
ACROSS PA TOWARDS NY WITH AN ATTENDANT MID-LEVEL DRY SLOT IMPINGING
NEWD TOWARDS NEW ENGLAND. AT THE SURFACE...A DEEPENING CYCLONE
INVOF NYC-LOWER HUDSON VALLEY WILL DEVELOP NEWD OFF THE COAST
BETWEEN CAPE COD AND NOVA SCOTIA BY 21Z. A REDUCTION IN LOW LEVEL
STATIC STABILITY DUE IN PART TO THE APPROACHING PV-ANOMALY FROM THE
SW COMBINED WITH FRONTOGENESIS IN THE H85-H7 LAYER SUPPORT WILL
SUPPORT ENHANCED PRECIP RATES THROUGH MID AFTERNOON. AFOREMENTIONED
MID-LEVEL DRY SLOT IS FORECAST TO MOVE NEWD INTO THE REGION THROUGH
00Z AND FIRST AFFECT THE SWRN HALF OF THE AREA BY 21Z. THIS WILL
COINCIDE WITH A WEAKENING IN THE HEAVIEST SNOWFALL RATES /I.E. 1
INCH PER HOUR/. FARTHER E OVER THE IMMEDIATE COASTAL AREAS...SOME
FORECAST SOUNDINGS SHOW LOW LEVEL THERMAL PROFILES GRADUALLY
SUPPORTING THE POSSIBILITY OF A CHANGEOVER FROM PRIMARILY SNOW TO
MIXED P-TYPE.
..SMITH.. 02/25/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...CAR...GYX...BTV...
LAT...LON 44866699 44286919 43197153 43457264 43997250 45446971
45906786 44866699SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 25, 4:28 AM EST | Mesoscale Discussion | SPC | Belknap, Carroll, Cheshire, Grafton, Merrimack, Sullivan | 6 hr |
Nearby
Mesoscale Discussions in Maine, 2011Mesoscale Discussions in New Hampshire, 2011Mesoscale Discussions in Vermont, 2011Every mesoscale discussion in 2011
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.