Alert archive / Vermont / Mesoscale Discussions in 2012

Mesoscale Discussion 81

January 27, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Jan 27, 2012, 4:21 AM EST for 4 states. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Jan 27, 2012, 4:21 AM EST (09:21 UTC)
Expired: Jan 27, 2012, 7:15 AM EST
In force: 3 hr
Issued by: the Storm Prediction Center

Counties Franklin County, ME, Oxford County, ME, Coos County, NH, Clinton County, NY, Caledonia County, VT, Chittenden County, VT, Essex County, VT, Franklin County, VT, Grand Isle County, VT, Lamoille County, VT, Orleans County, VT, Washington County, VT

The radar

The Burlington radar (KCXX), 95 km from the middle of the area, began a volume at 09:23 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, 9.4 hours before the alert went out and 180 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: 2158 m above ground
0-6 km bulk shear: 67 kt
0-1 km storm-relative helicity: 34 m²/s²
0-3 km storm-relative helicity: 199 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.

706 
ACUS11 KWNS 270922
SWOMCD
SPC MCD 270921
MEZ000-NHZ000-VTZ000-NYZ000-271215-

MESOSCALE DISCUSSION 0081
NWS STORM PREDICTION CENTER NORMAN OK
0321 AM CST FRI JAN 27 2012

AREAS AFFECTED...NERN NY...NRN VT/NH...WRN ME

CONCERNING...FREEZING RAIN

VALID 270921Z - 271215Z

A MIXTURE OF SNOW...SLEET AND FREEZING RAIN IS FORECAST TO
TRANSITION TO PRIMARILY FREEZING RAIN BETWEEN 10-12Z OVER PORTIONS
OF NERN NY...NRN VT/NH AND WRN ME. FREEZING RAINFALL RATES MAY
LOCALLY EXCEED 0.03 IN/HR.

LOW-LEVEL WAA REGIME IS FORECAST TO STRENGTHEN THIS MORNING OVER NEW
ENGLAND WITHIN THE EXIT REGION OF INTENSIFYING LLJ. THIS WILL AID IN
MAINTAINING A BROAD PRECIPITATION SHIELD OVER THE REGION...WHICH IS
FORECAST TO EXPAND ACROSS NERN NY INTO NRN VT/NH AND WRN ME THROUGH
15Z. IN ADDITION...MODEL FORECAST SOUNDINGS SHOW A WARM NOSE
CENTERED JUST ABOVE 850 MB WILL EXPERIENCE FURTHER WARMING
/TEMPERATURES INCREASING TO NEAR 5C/ ABOVE A SUB-FREEZING NEAR
SURFACE AIRMASS. GIVEN THE SHORT-TERM EVOLUTION OF THE LOW-LEVEL
THERMODYNAMIC STRUCTURE COMBINED WITH INCREASING PRECIPITATION
RATES...MIXED WINTER PRECIPITATION SHOULD TRANSITION TO PRIMARILY
FREEZING RAIN DURING THE NEXT FEW HOURS...WITH LOCALLY SIGNIFICANT
ICING POSSIBLE. MODEL GUIDANCE INDICATES SURFACE TEMPERATURES MAY
WARM ABOVE FREEZING OVER NERN NY BY 12-15Z...RESULTING IN A
TRANSITION TO RAIN. HOWEVER...A LONGER DURATION OF FREEZING RAIN MAY
CONTINUE OVER NRN VT/NH AND WRN ME THROUGH MID-MORNING.

..GARNER.. 01/27/2012

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

ATTN...WFO...GYX...BTV...

LAT...LON   45007376 45017160 45557071 45356989 44347037 44197261
            44457387 45007376

Nearby

Mesoscale Discussions in Vermont, 2012 Mesoscale Discussions in Maine, 2012 Mesoscale Discussions in New Hampshire, 2012 Every 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.