Alert archive / New York / Mesoscale Discussions in 2012

Mesoscale Discussion 1948

September 14, 201221 counties in New York

The Storm Prediction Center issued this mesoscale discussion at Sep 14, 2012, 5:33 PM EDT for 21 counties in New York. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued
Sep 14, 2012, 5:33 PM EDT (21:33 UTC)
Expired
Sep 14, 2012, 6:30 PM EDT
In force
57 min
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 21 counties

Allegany County, NY, Cayuga County, NY, Clinton County, NY, Cortland County, NY, Franklin County, NY, Hamilton County, NY, Herkimer County, NY, Jefferson County, NY, Lewis County, NY, Madison County, NY, Oneida County, NY, Onondaga County, NY, Ontario County, NY, Oswego County, NY, Schuyler County, NY, Seneca County, NY, St. Lawrence County, NY, Steuben County, NY, Tompkins County, NY, Wayne County, NY, Yates County, NY

The radar

The Ft Drum radar (KTYX), 48 km from the middle of the area, began a volume at 21:34 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, 9.6 hours before the alert went out and 203 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 2012-09-14Temperature 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 2012-09-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 square meters per square second.1939Sfc1 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
1102 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
3 m²/s²
0-3 km storm-relative helicity
30 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.

711 
ACUS11 KWNS 142133
SWOMCD
SPC MCD 142133 
NYZ000-142230-

MESOSCALE DISCUSSION 1948
NWS STORM PREDICTION CENTER NORMAN OK
0433 PM CDT FRI SEP 14 2012

AREAS AFFECTED...NY ADIRONDACKS AND FINGER LAKES

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 142133Z - 142230Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...A FEW STRONG STORMS...PERHAPS CAPABLE OF AN ISOLD WIND
DAMAGE RISK WILL PROBABLY PERSIST FOR A FEW MORE HOURS BEFORE
WEAKENING NEAR SUNSET.  IF STORMS INCREASE IN INTENSITY SWD TO THE
PA/NY BORDER...THEN WATCH PROBABILITIES WILL INCREASE.

DISCUSSION...21Z SURFACE MESOANALYSIS SHOWS A SURFACE LOW INVOF NERN
LAKE ONTARIO WITH A COLD FRONT MOVING EWD AND DRAPED FROM THE ST.
LAWRENCE VALLEY SSWWD INTO WRN NY.  A VIGOROUS SHORTWAVE TROUGH IS
MOVING INTO THE REGION FROM THE LAKE HURON VICINITY THIS
EVENING...WITH AN ATTENDANT INCREASE IN FORCING FOR ASCENT AND A
STRENGTHENING WIND PROFILE.

RADAR IMAGERY SHOWS A MIX OF LOW TOPPED TSTMS IN THE FORM OF CELLS
AND BROKEN LINE SEGMENTS...AND THIS CONVECTION WILL AFFECT THE
FINGER LAKES REGION NWD NEAR THE ONTARIO/NY BORDER OVER THE NEXT 1-2
HRS.  RADAR TRENDS OVER THE PAST HOUR HAVE SHOWN A GRADUAL INCREASE
IN INTENSITY...WITH A SUPERCELL EXHIBITING PERSISTENT ROTATION
TRAVERSING THE NRN SHORE OF LAKE ONTARIO.  THIS STORM IS LOCATED
NEAR THE SURFACE LOW AND WILL PROBABLY AFFECT PORTIONS OF ST.
LAWRENCE COUNTY NY PRIOR TO 2230Z.  ALTHOUGH ONLY MODEST
MOISTURE...CHARACTERIZED BY UPPER 50S DEWPOINTS...AND INSTABILITY
ARE PRESENT...THE STRENGTH OF FORCING WILL LIKELY AID IN SUSTAINING
THE STORMS FOR AT LEAST SEVERAL MORE HOURS.  THE STRONGEST STORMS
MAY BE CAPABLE OF A WIND DAMAGE RISK.

..SMITH/CORFIDI.. 09/14/2012

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

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

LAT...LON   42087828 42987742 44587640 45297512 45167334 44697355
            43257475 42377631 42027763 42087828

Nearby

Mesoscale Discussions in New York, 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.