Alert archive / Vermont / Mesoscale Discussions in 2017

Mesoscale Discussion 152

February 7, 20174 states

The Storm Prediction Center issued this mesoscale discussion at Feb 7, 2017, 5:44 PM EST for 4 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Feb 7, 2017, 5:44 PM EST (22:44 UTC)
Expired
Feb 7, 2017, 10:45 PM EST
In force
5 hr
Issued by
the Storm Prediction Center
All 29 counties

Franklin County, MA, Belknap County, NH, Carroll County, NH, Cheshire 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, Rensselaer County, NY, Saratoga County, NY, Warren County, NY, Washington County, NY, Addison County, VT, Bennington County, VT, Caledonia County, VT, Chittenden County, VT, Grand Isle County, VT, Lamoille County, VT, Orange 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 22:45 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, 10.7 hours before the alert went out and 114 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-pSkew-T log-p diagram, Albany, NY at 12:00Z on 2017-02-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Albany, NY at 12:00Z on 2017-02-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 127 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
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
1093 m above ground
0-6 km bulk shear
72 kt
0-1 km storm-relative helicity
127 m²/s²
0-3 km storm-relative helicity
253 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

511 
ACUS11 KWNS 072245
SWOMCD
SPC MCD 072244 
MEZ000-MAZ000-NHZ000-VTZ000-NYZ000-080345-

Mesoscale Discussion 0152
NWS Storm Prediction Center Norman OK
0444 PM CST Tue Feb 07 2017

Areas affected...Northeast NY...Most of VT and NH...Northern
MA...Far southwest ME

Concerning...Winter mixed precipitation 

Valid 072244Z - 080345Z

SUMMARY...Mixed winter precipitation is expected over the region as
precipitation transitions from snow to sleet to freezing rain and
eventually to all rain. Freezing rain rates may exceed 0.03" to
0.05" an hour.

DISCUSSION...Surface observations across northeastern NY, southern
VT, and northern MA have been reporting freezing rain rates around
0.03" to 0.06" per hour with ice accretion up 0.05" in the last
hour. General expectation for the next few hours is for
precipitation to continue across this region but warming mid-level
and surface temperatures will promote a transition to all rain. 

Farther north, ongoing light to moderate snowfall is expected to
gradually transition to sleet as mid-level temperatures warm within
the warm conveyor while surface temperatures remain in the mid to
upper 20s. The sleet is then expected to transition to mostly
freezing rain as mid-level warming continues amidst gradual surface
warming. Freezing rain rates near 0.03 to 0.05" per hour are likely.
An eventual transition to all rain is currently expected later
tonight.

..Mosier.. 02/07/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...GYX...BOX...BTV...ALY...

LAT...LON   43567482 44357503 45047401 44427142 43207055 42377170
            42387325 43567482

Nearby

Mesoscale Discussions in Vermont, 2017Mesoscale Discussions in New Hampshire, 2017Mesoscale Discussions in New York, 2017Every mesoscale discussion in 2017

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.