Alert archive / Maine / Mesoscale Discussions in 2012
Mesoscale Discussion 17
The Storm Prediction Center issued this mesoscale discussion at Jan 12, 2012, 11:19 AM EST for 9 counties in Maine; 4 counties in New Hampshire. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Jan 12, 2012, 11:19 AM EST (16:19 UTC)
- Expired
- Jan 12, 2012, 4:15 PM EST
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
Counties Androscoggin County, ME, Cumberland County, ME, Franklin County, ME, Kennebec County, ME, Oxford County, ME, Penobscot County, ME, Piscataquis County, ME, Somerset County, ME, Waldo County, ME, Belknap County, NH, Carroll County, NH, Merrimack County, NH, Strafford County, NH
The radar
The Portland,ME radar (KGYX), 81 km from the middle of the area, began a volume at 16:19 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, 4.3 hours before the alert went out and 81 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
- 665 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 326 m²/s²
- 0-3 km storm-relative helicity
- 360 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
878
ACUS11 KWNS 121619
SWOMCD
SPC MCD 121619
MEZ000-NHZ000-122115-
MESOSCALE DISCUSSION 0017
NWS STORM PREDICTION CENTER NORMAN OK
1019 AM CST THU JAN 12 2012
AREAS AFFECTED...PARTS OF NRN NEW ENGLAND
CONCERNING...HEAVY SNOW
VALID 121619Z - 122115Z
A BAND OF HEAVY SNOW WILL DEVELOP NEWD ACROSS MOST OF ME THROUGH THE
AFTERNOON WITH RATES OF 1 TO 1.5 IN/HR PROBABLE. ALTHOUGH SNOW WILL
LIKELY REMAIN THE PREDOMINANT PTYPE...A NARROW CORRIDOR OF MIXED
PRECIP SHOULD ACCOMPANY THE SERN EDGE OF THE HEAVY SNOW BAND MAINLY
OVER COASTAL ME.
A LARGE SWATH OF PRECIPITATION...PREDOMINANTLY CONSISTING OF SNOW
AND RAIN PERSISTS DOWNSTREAM OF A SHORT WAVE IMPULSE CENTERED OVER
LONG ISLAND/SRN NEW ENGLAND COAST. AS THIS IMPULSE PROGRESSES
TOWARDS DOWNEAST ME THROUGH 00Z...ACCOMPANYING REGION OF MID-LEVEL
DCVA AND ROBUST LOW-LEVEL WAA /AS INFERRED BY QUITE LARGE CYCLONIC
HODOGRAPHS IN AREA VWP DATA/ SHOULD RESULT IN STRONGEST DEEP-LAYER
ASCENT TO BECOME FOCUSED WHERE THE THERMODYNAMIC PROFILE WILL
LARGELY REMAIN AOB FREEZING ACROSS MUCH OF ME. WITH THIS ASCENT
CONCENTRATED WITHIN AND ABOVE A DEEP NEARLY ISOTHERMAL LAYER FROM
THE SURFACE TO AROUND 700 MB...PER 12Z ALB/GYX/CAR RAOBS...SNOWFALL
RATES OF 1 TO 1.5 IN/HR SHOULD BECOME INCREASINGLY COMMON. THESE
RATES ARE WELL SUPPORTED BY MORNING OPERATIONAL AND
CONVECTION-ALLOWING MODEL GUIDANCE...AND APPEAR TO HAVE COMMENCED
WITH 1/4 TO 1/2 MILE VISIBILITIES AND LIQUID-EQUIVALENT RATES
APPROACHING 0.15 IN/HR IN 16Z METARS FROM THE VT/MA/NY BORDER NEWD
INTO SWRN ME.
..GRAMS.. 01/12/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...CAR...GYX...BOX...
LAT...LON 43717187 44707125 45757022 46296965 46836830 46716777
45206732 44376919 43257097 43077137 43087190 43357201
43717187SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 12, 3:52 AM EST | Mesoscale Discussion | SPC | Cheshire, Sullivan | 6 hr |
Nearby
Mesoscale Discussions in Maine, 2012Mesoscale Discussions in New Hampshire, 2012Every mesoscale discussion in 2012
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.