Alert archive / Vermont / Mesoscale Discussions in 2012
Mesoscale Discussion 1936
The Storm Prediction Center issued this mesoscale discussion at Sep 8, 2012, 3:55 PM EDT for 6 states. It was in force for 65 min.
The area
The outline as issued.
The facts
- Issued
- Sep 8, 2012, 3:55 PM EDT (19:55 UTC)
- Expired
- Sep 8, 2012, 5:00 PM EDT
- In force
- 65 min
- Issued by
- the Storm Prediction Center
All 43 counties
Berkshire County, MA, Bristol County, MA, Essex County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Norfolk County, MA, Suffolk County, MA, Worcester County, MA, Androscoggin County, ME, Cumberland County, ME, Oxford County, ME, York County, ME, Belknap County, NH, Carroll County, NH, Cheshire County, NH, Coos County, NH, Grafton County, NH, Hillsborough County, NH, Merrimack County, NH, Rockingham County, NH, Strafford County, NH, Sullivan County, NH, Columbia County, NY, Rensselaer County, NY, Washington County, NY, Bristol County, RI, Kent County, RI, Providence County, RI, Addison County, VT, Bennington County, VT, Caledonia County, VT, Chittenden County, VT, Essex County, VT, Franklin 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 Portland,ME radar (KGYX), 140 km from the middle of the area, began a volume at 19:57 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.
The nearest sounding before it
Gray, ME (KGYX), launched 12:00Z, 7.9 hours before the alert went out and 139 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
- 1021 J/kg
- Mixed-layer CIN
- -20 J/kg
- Mixed-layer LCL
- 466 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 176 m²/s²
- 0-3 km storm-relative helicity
- 216 m²/s²
- Significant tornado parameter
- 0.9
- Supercell composite
- 7.2
The text
As transmitted, in the capitals the NWS used until 2016.
933
ACUS11 KWNS 081956
SWOMCD
SPC MCD 081955
MEZ000-MAZ000-NHZ000-RIZ000-VTZ000-CTZ000-NYZ000-082100-
MESOSCALE DISCUSSION 1936
NWS STORM PREDICTION CENTER NORMAN OK
0255 PM CDT SAT SEP 08 2012
AREAS AFFECTED...WRN/SRN NEW ENGLAND
CONCERNING...TORNADO WATCH 635...637...
VALID 081955Z - 082100Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 635...637...CONTINUES.
SUMMARY...A NEW WW WILL LIKELY BE ISSUED FOR AREAS DOWNSTREAM OF WW
635/637 IN SRN NEW ENGLAND BY 21Z.
DISCUSSION...QLCS HAS ACCELERATED IN FORWARD SPEED TO AROUND 40 KT
WHICH WOULD EXTRAPOLATE THE LEADING EDGE TOWARDS THE NH BORDER NEAR
2130Z. ALTHOUGH SURFACE TEMPERATURES ARE SLIGHTLY COOLER TO THE EAST
THAN THE HUDSON/CHAMPLAIN VALLEY...DEW POINTS HAVE LARGELY REMAINED
IN THE MIDDLE 60S TO LOWER 70S AND IS LIKELY YIELDING WEAK BUOYANCY
PER MODIFIED 18Z OKX/ALB RAOBS. LOW/DEEP-LAYER SHEAR PROFILES WILL
REMAIN RATHER FAVORABLE FOR SUSTENANCE OF THE QLCS AND PRE-FRONTAL
WEAK/TRANSIENT SUPERCELLS. THIS SETUP SHOULD RESULT IN SCATTERED
DAMAGING WINDS ALONG WITH A SECONDARY THREAT FOR A BRIEF TORNADO OR
TWO.
..GRAMS.. 09/08/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...GYX...BOX...BTV...OKX...ALY...
LAT...LON 42847056 41787098 41387180 41377285 42047395 43367375
44147361 44877315 45217187 45157059 44416996 44016998
42847056SPC 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, 4:47 PM EDT | Severe Thunderstorm Watch | SPC | Capitol Planning Region, Northeastern Connecticut Planning Region | 6 hr |
| Sep 8, 6:17 PM EDT | Mesoscale Discussion | SPC | 58 min | |
| Sep 8, 7:53 PM EDT | Mesoscale Discussion | SPC | Androscoggin, Cumberland, Franklin, Kennebec, Oxford, Somerset and 1 more | 97 min |
| Sep 8, 2:46 PM EDT | Mesoscale Discussion | SPC | Berkshire | 59 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 Vermont, 2012Mesoscale Discussions in Massachusetts, 2012Mesoscale Discussions in New Hampshire, 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.