Alert archive / New York / Mesoscale Discussions in 2012

Mesoscale Discussion 1903

September 6, 201220 counties in New York; 8 counties in Vermont

The Storm Prediction Center issued this mesoscale discussion at Sep 6, 2012, 4:27 PM EDT for 20 counties in New York; 8 counties in Vermont. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued
Sep 6, 2012, 4:27 PM EDT (20:27 UTC)
Expired
Sep 6, 2012, 5:30 PM EDT
In force
63 min
Issued by
the Storm Prediction Center
All 28 counties

Allegany County, NY, Broome County, NY, Chemung County, NY, Chenango County, NY, Clinton County, NY, Cortland County, NY, Essex County, NY, Franklin County, NY, Hamilton County, NY, Herkimer County, NY, Madison County, NY, Oneida County, NY, Onondaga County, NY, Otsego County, NY, Schuyler County, NY, Seneca County, NY, Steuben County, NY, Tioga County, NY, Tompkins County, NY, Yates County, NY, Addison County, VT, Chittenden County, VT, Franklin County, VT, Grand Isle County, VT, Lamoille County, VT, Orleans County, VT, Rutland County, VT, Washington County, VT

The radar

The Albany radar (KENX), 91 km from the middle of the area, began a volume at 20:27 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, 8.5 hours before the alert went out and 93 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 2012-09-06Temperature 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 2012-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 square meters per square second.19395878Sfc1 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
816 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
27 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.

605 
ACUS11 KWNS 062027
SWOMCD
SPC MCD 062027 
VTZ000-NYZ000-062130-

MESOSCALE DISCUSSION 1903
NWS STORM PREDICTION CENTER NORMAN OK
0327 PM CDT THU SEP 06 2012

AREAS AFFECTED...WRN/CNTRL AND UPSTATE NY...VT

CONCERNING...SEVERE THUNDERSTORM WATCH 626...

VALID 062027Z - 062130Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 626
CONTINUES.

SUMMARY...DISCRETE CELLS AND POSSIBLE SMALL BOWING SEGMENTS WILL
CONTINUE TO PRODUCE DMGG WINDS AND HAIL ACROSS THE WW AREA. STABLE
LOCATIONS IN THE WAKE OF THE LK BREEZE MAY BE CLEARED FROM THE WW.

DISCUSSION...THUNDERSTORMS APPEAR TO HAVE DEVELOPED IN RESPONSE TO A
SUBTLE VORT MAX /OBSERVED ON 1945Z WV ACROSS UPSTATE AND WRN
NY/...AS WELL AS VARIOUS LK BREEZES...PREFRONTAL SURFACE
TROUGHS...AND OROGRAPHIC FORCING ALONG THE ADIRONDACKS. ALTHOUGH
SEVERAL CELLS HAVE ACHIEVED SEVERE STATUS...ORGANIZED/STRONGER
BOWING SEGMENTS APPEAR TO BE PRIMARILY LIMITED BY VERY WEAK UPPER
FORCING AND WEAKER LOW LEVEL WINDS COMPARED TO EARLIER TODAY.
ADDITIONALLY...ANVIL CLOUDS FROM ONGOING CONVECTION ARE RAPIDLY
SPREADING ENEWD...LEADING TO SEVERAL DEGREES OF COOLING DOWNSTREAM
OF THE ONGOING STORMS. NONETHELESS...MODEST WLY FLOW ALOFT WILL
CONTINUE TO SUPPORT A FEW STRONGER CELLS WHERE THE AIR MASS REMAINS
MODERATELY UNSTABLE.

..HURLBUT.. 09/06/2012

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

ATTN...WFO...BTV...ALY...BGM...BUF...

LAT...LON   42027535 42037840 42647781 43277556 44617481 45067416
            44967188 43977271 43317288 43317327 43767340 43707416
            43227422 43227470 42677472 42507476 42027535

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 6, 1:04 PM EDTMesoscale DiscussionSPCAllegany, Cattaraugus, Cayuga, Chemung, Clinton, Cortland and 20 more56 min
Sep 6, 2:50 PM EDTSevere Thunderstorm WatchSPCAllegany, Broome, Cattaraugus, Cayuga, Chemung, Chenango and 26 more6 hr
Sep 6, 6:45 PM EDTMesoscale DiscussionSPCBroome, Chemung, Chenango, Cortland, Delaware, Montgomery and 6 more60 min

Nearby

Mesoscale Discussions in New York, 2012Mesoscale Discussions in Vermont, 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.