Alert archive / Vermont / Mesoscale Discussions in 2011

Mesoscale Discussion 89

February 5, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Feb 5, 2011, 4:45 PM EST for 4 states. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Feb 5, 2011, 4:45 PM EST (21:45 UTC)
Expired: Feb 5, 2011, 8:45 PM EST
In force: 4 hr
Issued by: the Storm Prediction Center

All 32 counties

Oxford County, ME, Belknap County, NH, Carroll County, NH, Cheshire County, NH, Coos County, NH, Grafton County, NH, Merrimack County, NH, Strafford County, NH, Sullivan County, NH, Clinton County, NY, Essex County, NY, Franklin County, NY, Hamilton County, NY, Herkimer 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), 73 km from the middle of the area, began a volume at 21:44 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

Albany, NY (KALY), launched 12:00Z, 9.8 hours before the alert went out and 158 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: 2309 m above ground
0-6 km bulk shear: 79 kt
0-1 km storm-relative helicity: 195 m²/s²
0-3 km storm-relative helicity: 296 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.

129 
ACUS11 KWNS 052145
SWOMCD
SPC MCD 052145 
MEZ000-NHZ000-VTZ000-NYZ000-060145-

MESOSCALE DISCUSSION 0089
NWS STORM PREDICTION CENTER NORMAN OK
0345 PM CST SAT FEB 05 2011

AREAS AFFECTED...NERN NY...VT...NH AND WRN ME

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 052145Z - 060145Z

SNOWFALL RATES WILL INTENSIFY WITHIN INCREASINGLY ORGANIZED BANDED
STRUCTURES FROM NERN NY...NRN VT AND NRN NH...EXPANDING INTO WRN ME
THROUGH MID EVENING. RATES FROM 1-2 INCHES PER HOUR WILL BECOME
LIKELY. PRECIPITATION IS EXPECTED TO REMAIN OR CHANGE TO MOSTLY
FREEZING RAIN FROM SRN VT INTO SRN NH.

SURFACE LOW PRESSURE LOCATED OVER WRN PA WILL SHIFT ENEWD THIS
EVENING WITH ATTENDANT LLJ STRENGTHENING ACROSS SRN NEW ENGLAND IN
ASSOCIATION WITH NEWD EJECTING NEGATIVELY TILTED SHORTWAVE TROUGH. A
BROAD ZONE OF ISENTROPIC LIFT RESULTING FROM LLJ INTERACTING WITH
E-W ORIENTED BAROCLINIC ZONE IS CONTRIBUTING TO WIDESPREAD
PRECIPITATION FROM MUCH OF NY EWD THROUGH NEW ENGLAND. ACTIVITY IS
EXPECTED TO REMAIN MOSTLY SNOW FROM NERN NY THROUGH NRN VT...NRN NH
AND MUCH OF WRN ME. HOWEVER...STRONG WARM ADVECTION ALONG SLY 50+ KT
LLJ WILL CONTRIBUTE TO ABOVE FREEZING LAYERS ACROSS SRN VT...SRN NH
INTO SRN ME...LIKELY CHANGING PRECIPITATION TYPE TO FREEZING RAIN.
SURFACE ANALYSIS INDICATE AN AREA OF STRONG PRESSURE FALLS FROM NERN
PA INTO SRN NY...AND THIS ZONE WILL SHIFT EWD AHEAD OF SURFACE LOW
DURING THE EVENING ALONG WITH STRENGTHENING FRONTOGENETIC FORCING.
THIS ZONE OF FORCING SHOULD CONTRIBUTE TO STRENGTHENING VERTICAL
MOTION AND INCREASING PRECIPITATION RATES. MOREOVER...LAPSE RATES OF
7-7.5 C/KM BETWEEN 700-400 MB WILL MAINTAIN POTENTIAL FOR CONVECTIVE
PRECIPITATION ENHANCEMENT AND ISOLATED LIGHTNING STRIKES.

..DIAL.. 02/05/2011

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

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

LAT...LON   42767274 43347445 43657609 44817496 44917242 45117072
            44687019 43117100 42767274

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 5, 1:22 PM EST	Mesoscale Discussion	SPC	Albany, Broome, Chenango, Columbia, Cortland, Delaware and 14 more	4 hr

Nearby

Mesoscale Discussions in Vermont, 2011 Mesoscale Discussions in New York, 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.