Alert archive / Vermont / Mesoscale Discussions in 2011

Mesoscale Discussion 81

February 2, 20115 states

The Storm Prediction Center issued this mesoscale discussion at Feb 2, 2011, 2:57 AM EST for 5 states. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Feb 2, 2011, 2:57 AM EST (07:57 UTC)
Expired: Feb 2, 2011, 7:00 AM EST
In force: 4 hr
Issued by: the Storm Prediction Center

All 49 counties

Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Worcester County, MA, Androscoggin County, ME, Cumberland County, ME, Franklin County, ME, Kennebec County, ME, Lincoln County, ME, Oxford County, ME, Sagadahoc County, ME, Somerset County, ME, Waldo County, ME, York County, ME, Belknap County, NH, Carroll County, NH, Cheshire County, NH, Coos County, NH, Grafton County, NH, Hillsborough County, NH, Merrimack County, NH, Rockingham County, NH, Strafford County, NH, Sullivan County, NH, Clinton County, NY, Essex County, NY, Franklin County, NY, Hamilton County, NY, Herkimer County, NY, Jefferson County, NY, Lewis County, NY, St. Lawrence County, NY, Warren County, NY, Washington County, NY, Addison County, VT, Bennington County, VT, Caledonia County, VT, Chittenden County, VT, Essex County, VT, Franklin County, VT, Grand Isle County, VT, Lamoille County, VT, Orange County, VT, Orleans County, VT, Rutland County, VT, Washington County, VT, Windham County, VT, Windsor County, VT

The radar

The Burlington radar (KCXX), 100 km from the middle of the area, began a volume at 07:56 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

Gray, ME (KGYX), launched 00:00Z, 8.0 hours before the alert went out and 161 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 617 m above ground
0-6 km bulk shear: 80 kt
0-1 km storm-relative helicity: 116 m²/s²
0-3 km storm-relative helicity: 429 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

158 
ACUS11 KWNS 020757
SWOMCD
SPC MCD 020757 
MEZ000-MAZ000-NHZ000-VTZ000-CTZ000-NYZ000-021200-

MESOSCALE DISCUSSION 0081
NWS STORM PREDICTION CENTER NORMAN OK
0157 AM CST WED FEB 02 2011

AREAS AFFECTED...NRN NY AND MUCH OF INTERIOR/NRN NEW ENGLAND

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 020757Z - 021200Z

EAST BRANCH OF THE WARM CONVEYOR ATTENDANT TO MIDWEST CYCLONE
CONTINUES TO ENHANCE PCPN SHIELD SPREADING ACROSS NY AND
MID-ATLANTIC EARLY THIS MORNING.  LOW/MID-LEVEL DRY SLOT WILL
ADVANCE NEWD INTO PA/SRN NY THROUGH 10Z...REDUCING OR SHUTTING OFF
HEAVIER PCPN RATES THERE.  HOWEVER...GUIDANCE SUGGESTS THAT ZONE OF
1-2" PER HOUR SNOWFALL RATES WILL EVOLVE FROM NRN NY STATE EWD
ACROSS NRN/CNTRL PARTS OF VT/NH AND INTO CNTRL/SRN MAINE THROUGH
LATE MORNING.  HERE...COBB SNOWFALL RATIOS BASED OFF THE 00Z NAM
SUGGEST AROUND 15:1 AND GIVEN UPSTREAM LIQUID EQUIV RATES
APPROACHING 0.10" PER HOUR...HOURLY SNOWFALL RATES SHOULD FIT
COMFORTABLY IN THE 1-2" RANGE.  THE HEAVIEST RATES SHOULD EXIST
WITHIN A 40 MILE CORRIDOR CENTERED KSLK-KBML-KBGR.  HEAVIER SNOW
WILL GRADUALLY END FROM W-E THROUGH THE MORNING. 

MEANWHILE...SRN EXTENTS OF PCPN SHIELD WILL OFFER A P-TYPE
CHALLENGE.  WHILE THERE WILL LIKELY BE A 3-4 HOUR PERIOD OF
MDT-HEAVY SNOW OVER SERN NEW ENGLAND...GRADUAL CHANGEOVER TO
SLEET/FREEZING RAIN WILL OCCUR WITH MOST INTENSE PCPN RATES IN CNTRL
MA INTO SERN NH...ALA 00Z NAM/21Z SREF SOLUTIONS...IN THE 10-15Z
TIME FRAME.  THOSE RATES SHOULD BEGIN TO WANE AFTER 15Z AS MOST
FORCING BEGINS TO MOVE INTO INTERIOR NRN NEW ENGLAND.

..RACY.. 02/02/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...CAR...GYX...BOX...BTV...ALY...BUF...

LAT...LON   43866953 43007065 42277161 41997247 42217294 42727324
            43057342 43387380 43517464 43857595 44087617 44717555
            45077471 45117163 45677079 45856976 45146831 44436847
            43866953

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 2, 10:00 AM EST	Mesoscale Discussion	SPC	Androscoggin, Aroostook, Cumberland, Franklin, Hancock, Kennebec and 9 more	6 hr
Feb 1, 11:21 PM EST	Mesoscale Discussion	SPC	Bronx, Dutchess, Kings, Nassau, New York, Orange and 6 more	6 hr

Nearby

Mesoscale Discussions in Vermont, 2011 Mesoscale Discussions in Maine, 2011 Mesoscale Discussions in New Hampshire, 2011 Every 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.