Alert archive / Connecticut / Mesoscale Discussions in 2012
Mesoscale Discussion 1939
The Storm Prediction Center issued this mesoscale discussion at Sep 8, 2012, 6:17 PM EDT for Berkshire County, Franklin County, Massachusetts; Suffolk County, New York; 5 counties in Vermont. It was in force for 58 min.
The area
The outline as issued.
The facts
- Issued
- Sep 8, 2012, 6:17 PM EDT (22:17 UTC)
- Expired
- Sep 8, 2012, 7:15 PM EDT
- In force
- 58 min
- Issued by
- the Storm Prediction Center
Counties Berkshire County, MA, Franklin County, MA, Suffolk County, NY, Caledonia County, VT, Essex County, VT, Orange County, VT, Windham County, VT, Windsor County, VT
The radar
The Albany radar (KENX), 136 km from the middle of the area, began a volume at 22:18 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, 10.3 hours before the alert went out and 115 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.
- Mixed-layer CAPE
- 113 J/kg
- Mixed-layer CIN
- -168 J/kg
- Mixed-layer LCL
- 869 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km storm-relative helicity
- 294 m²/s²
- 0-3 km storm-relative helicity
- 397 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.8
The text
As transmitted, in the capitals the NWS used until 2016.
724
ACUS11 KWNS 082218
SWOMCD
SPC MCD 082217
NHZ000-VTZ000-CTZ000-NYZ000-MAZ000-082315-
MESOSCALE DISCUSSION 1939
NWS STORM PREDICTION CENTER NORMAN OK
0517 PM CDT SAT SEP 08 2012
AREAS AFFECTED...SOUTHEAST NY/LONG ISLAND TO CT/VT/WESTERN MA
CONCERNING...TORNADO WATCH 635...637...
VALID 082217Z - 082315Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 635...637...CONTINUES.
SUMMARY...ISOLATED/BRIEF TORNADO POTENTIAL CONTINUES ACROSS FAR
SOUTHEAST NY INTO CT/WESTERN MA THROUGH EARLY EVENING...ALTHOUGH
DAMAGING WINDS WILL BE THE MAIN THREAT. TORNADO WATCH 635 CONTINUES
UNTIL 01Z...WHILE THE OVERALL SEVERE THREAT CONTINUES TO QUICKLY
WANE WITHIN TORNADO WATCH 637 /EARLY CANCELLATION PROBABLE/.
DISCUSSION...NEAR A COLD FRONT...A LONG-LIVED/RELATIVELY LOW-TOPPED
SQUALL LINE CONTINUES TO STEADILY PROGRESS /30-35 KT/
EAST-NORTHEASTWARD ACROSS FAR SOUTHEAST NY INTO WESTERN CT/MA AND
FROM VT INTO NH AS OF 22Z...WITH THE MOST INTENSE /BY VIRTUE OF
REFLECTIVITY AND LIGHTNING CHARACTERISTICS/ PORTION NOW ENTERING
WESTERN CT/MA. ALONG WITH CONSIDERABLE CLOUD COVER...SURFACE
TEMPERATURES CONTINUE TO SLOWLY COOL /A DEGREE OR TWO PER HR/ AHEAD
OF THE SQUALL LINE...ALTHOUGH LOW-LEVEL MOIST ADVECTION ALSO
CONTINUES TO OCCUR TO A DEGREE. WITHIN A WEAKLY UNSTABLE/HIGHLY
SHEARED ENVIRONMENT...DAMAGING WINDS WILL REMAIN A DISTINCT
POSSIBILITY THROUGH EARLY EVENING INTO MA/CT AND PERHAPS LONG
ISLAND. A BRIEF/ISOLATED TORNADO WILL ALSO REMAIN POSSIBLE THROUGH
23Z-00Z WITH ANY APPRECIABLE LINE-EMBEDDED MESO-VORTICES...GIVEN A
MOIST ENVIRONMENT AND 0-1 KM SRH ON THE ORDER OF 200 M2/S2 PER
WSR-88D VWP DATA FROM OKX/BOX.
OTHERWISE...EARLY CANCELLATION OF TORNADO WATCH 637 IS LIKELY AS THE
SQUALL LINE/ASSOCIATED SEVERE THREAT CONTINUES TO QUICKLY SHIFT
EASTWARD ACROSS NEW ENGLAND OUT OF WW 637 AND INTO WW 639.
..GUYER.. 09/08/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...GYX...BOX...BTV...OKX...ALY...
LAT...LON 44777225 44897155 43487218 42157275 41967241 41737180
40517297 41317372 43587269 44777225SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 8, 10:39 AM EDT | Mesoscale Discussion | SPC | 2 hr | |
| Sep 8, 11:18 AM EDT | Tornado Watch | SPC | Greater Bridgeport Planning Region, Capitol Planning Region, Northwest Hills Planning Region, Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region, Southeastern Connecticut Planning Region | 10 hr |
| Sep 8, 12:40 PM EDT | Tornado Watch | SPC | Northwest Hills Planning Region | 7 hr |
| Sep 8, 1:30 PM EDT | Mesoscale Discussion | SPC | 60 min | |
| Sep 8, 3:55 PM EDT | Mesoscale Discussion | SPC | 65 min | |
| Sep 8, 4:47 PM EDT | Severe Thunderstorm Watch | SPC | Capitol Planning Region, Northeastern Connecticut Planning Region | 6 hr |
| Sep 8, 2:46 PM EDT | Mesoscale Discussion | SPC | Berkshire | 59 min |
| Sep 8, 7:53 PM EDT | Mesoscale Discussion | SPC | Bristol, Dukes, Essex, Middlesex, Norfolk, Plymouth and 2 more | 97 min |
| Sep 8, 12:57 AM EDT | Mesoscale Discussion | SPC | Chautauqua | 2 hr |
| Sep 8, 8:42 AM EDT | Mesoscale Discussion | SPC | Broome, Cayuga, Chemung, Chenango, Cortland, Herkimer and 13 more | 93 min |
| Sep 8, 10:03 AM EDT | Severe Thunderstorm Watch | SPC | Allegany, Cattaraugus, Cayuga, Chemung, Franklin, Genesee and 16 more | 5 hr |
| Sep 8, 11:38 AM EDT | Mesoscale Discussion | SPC | Albany, Broome, Chemung, Chenango, Cortland, Delaware and 18 more | 97 min |
| Sep 8, 2:12 PM EDT | Mesoscale Discussion | SPC | Richmond | 93 min |
| Sep 8, 4:22 PM EDT | Mesoscale Discussion | SPC | Richmond | 53 min |
Nearby
Mesoscale Discussions in Connecticut, 2012Mesoscale Discussions in Vermont, 2012Mesoscale Discussions in Massachusetts, 2012Every 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.