Alert archive / Vermont / Mesoscale Discussions in 2011

Mesoscale Discussion 1004

May 28, 20115 counties in New York; 11 counties in Vermont

The Storm Prediction Center issued this mesoscale discussion at May 28, 2011, 1:42 PM EDT for 5 counties in New York; 11 counties in Vermont. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued: May 28, 2011, 1:42 PM EDT (17:42 UTC)
Expired: May 28, 2011, 2:45 PM EDT
In force: 63 min
Issued by: the Storm Prediction Center

Counties Clinton County, NY, Essex County, NY, Saratoga County, NY, Warren County, NY, Washington County, NY, Addison County, VT, Bennington County, VT, Chittenden County, VT, Franklin 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), 76 km from the middle of the area, began a volume at 17:43 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 391May 28, 1:45 PM EDT

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 5.7 hours before the alert went out and 140 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: 167 J/kg
Mixed-layer CIN: -146 J/kg
Mixed-layer LCL: 742 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 124 m²/s²
0-3 km storm-relative helicity: 177 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

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

326 
ACUS11 KWNS 281743
SWOMCD
SPC MCD 281742
NHZ000-VTZ000-NYZ000-281845-

MESOSCALE DISCUSSION 1004
NWS STORM PREDICTION CENTER NORMAN OK
1242 PM CDT SAT MAY 28 2011

AREAS AFFECTED...NE NY...VT

CONCERNING...SEVERE POTENTIAL...WATCH NEEDED SOON

VALID 281742Z - 281845Z

A SEVERE THREAT WILL CONTINUE TO DEVELOP ACROSS NE NY AND VT THIS
AFTERNOON. WIND DAMAGE AND HAIL ARE EXPECTED TO BE THE PRIMARY
THREATS WITH THE ACTIVITY. A SEVERE THUNDERSTORM WATCH IS BEING
ISSUED ATTM.

WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH APPROACHING NEW
ENGLAND. LIFT AHEAD OF THIS FEATURE AND SFC HEATING WILL PROVIDE
SUPPORT FOR CONTINUED STORM INITIATION ACROSS NERN NY AND VT OVER
THE NEXT FEW HOURS. MLCAPE VALUES OF 1000 TO 1200 J/KG AND DEEP
LAYER SHEAR OF 35 TO 40 KT SHOULD BE SUFFICIENT FOR SEVERE STORMS.
THE LATEST WSR-88D VWPS ACROSS THE REGION SHOW 25 TO 30 KT OF
LOW-LEVEL FLOW SUGGESTING A WIND DAMAGE THREAT WILL EXIST WITH THE
MORE ORGANIZED STORMS. THE MORE INTENSE CELLS SHOULD ALSO CONTAIN A
THREAT FOR HAIL.

..BROYLES.. 05/28/2011

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

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

LAT...LON   44587231 45017288 44927348 44557400 43857430 43387437
            42927412 42897355 42837291 42977264 43257241 43667216
            44267216 44587231

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 28, 1:45 PM EDT	Severe Thunderstorm Watch	SPC	Clinton, Essex	5 hr
May 28, 5:37 PM EDT	Mesoscale Discussion	SPC	Clinton, Essex	53 min

Nearby

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