Alert archive / New York / Mesoscale Discussions in 2011

Mesoscale Discussion 2175

September 13, 201116 counties in New York; Trumbull County, Ohio; 7 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at Sep 13, 2011, 7:00 PM EDT for 16 counties in New York; Trumbull County, Ohio; 7 counties in Pennsylvania. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued: Sep 13, 2011, 7:00 PM EDT (23:00 UTC)
Expired: Sep 13, 2011, 8:00 PM EDT
In force: 60 min
Issued by: the Storm Prediction Center

All 24 counties

Allegany County, NY, Cattaraugus County, NY, Cayuga County, NY, Chautauqua County, NY, Lewis County, NY, Livingston County, NY, Madison County, NY, Oneida County, NY, Onondaga County, NY, Ontario County, NY, Oswego County, NY, Schuyler County, NY, Seneca County, NY, Steuben County, NY, Wyoming County, NY, Yates County, NY, Trumbull County, OH, Crawford County, PA, Erie County, PA, Forest County, PA, McKean County, PA, Mercer County, PA, Venango County, PA, Warren County, PA

The radar

The Buffalo radar (KBUF), 86 km from the middle of the area, began a volume at 23:03 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

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 11.0 hours before the alert went out and 83 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: 69 J/kg
Mixed-layer CIN: -120 J/kg
Mixed-layer LCL: 1273 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 143 m²/s²
0-3 km storm-relative helicity: 209 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.

755 
ACUS11 KWNS 132301
SWOMCD
SPC MCD 132300
NYZ000-PAZ000-OHZ000-140000-

MESOSCALE DISCUSSION 2175
NWS STORM PREDICTION CENTER NORMAN OK
0600 PM CDT TUE SEP 13 2011

AREAS AFFECTED...NWRN PA...AND WRN-NRN NY

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 132300Z - 140000Z

A FEW STRONG TO SEVERE TSTMS WILL BE POSSIBLE DURING THE EARLY
EVENING FROM NWRN PA INTO WRN-NRN NY.  GIVEN TIME OF DAY WITH THE
ONSET OF BOUNDARY LAYER COOLING/STABILIZATION...SPATIOTEMPORAL
LIMITATIONS PRECLUDE THE NEED FOR A WW.

EARLY EVENING VISIBLE/REGIONAL RADAR IMAGERY AND LIGHTNING DATA
INDICATED A COUPLE NE-SW ORIENTED BANDS OF CONVECTION /WITH EMBEDDED
TSTMS/ IN LEE OF LAKES ONTARIO AND ERIE.  THIS CONVECTION IS LOCATED
ALONG LAKE BREEZES AND A PRE-FRONTAL WIND SHIFT THAT HAS JUST MOVED
E AND S OF LAKE ERIE.  THE NEWD EXTENSION OF LATE DAY INSTABILITY
EXTENDED INTO NERN OH/NWRN PA...WHILE INSTABILITY WAS WEAKER FARTHER
NNEWD TO IN LEE OF LAKE ONTARIO.  9 KM CAPPI IMAGERY SHOWED THE MORE
PERSISTENT STORMS LOCATED OVER NWRN PA INTO ADJACENT SWRN NY AND FAR
NERN OH WHERE THE GREATER INSTABILITY WAS JUXTAPOSED WITH THE SRN
EXTENT OF STRONG EFFECTIVE BULK SHEAR.  A FEW OF THESE STORMS COULD
PRODUCE HAIL APPROACHING SEVERE VALUES...GIVEN PROXIMITY TO STEEPER
MIDLEVEL LAPSE RATES OVER THE OH VALLEY.  DESPITE WEAKER INSTABILITY
IN LEE OF LAKE ONTARIO...STRONG EFFECTIVE BULK SHEAR MAY CONTINUE TO
SUPPORT A COUPLE OF STRONGER UPDRAFTS YET THIS EVENING WITH AN
ISOLATED THREAT FOR STRONGER WIND GUSTS AND/OR SMALL HAIL.

..PETERS.. 09/13/2011

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

ATTN...WFO...BTV...ALY...BGM...BUF...CTP...PBZ...CLE...

LAT...LON   41367909 41148050 41438125 42038036 42867843 43197706
            43597609 44247532 44277460 43217503 42207701 41667851
            41367909

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 13, 2:44 PM EDT	Mesoscale Discussion	SPC	Cayuga, Clinton, Erie, Essex, Franklin, Genesee and 19 more	91 min

Nearby

Mesoscale Discussions in New York, 2011 Mesoscale Discussions in Pennsylvania, 2011 Mesoscale Discussions in Ohio, 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.