Alert archive / New York / Mesoscale Discussions in 2012

Mesoscale Discussion 894

May 25, 201220 counties in New York

The Storm Prediction Center issued this mesoscale discussion at May 25, 2012, 3:08 PM EDT for 20 counties in New York. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued
May 25, 2012, 3:08 PM EDT (19:08 UTC)
Expired
May 25, 2012, 4:45 PM EDT
In force
97 min
Issued by
the Storm Prediction Center
Chance of a watch
40%

Counties Cayuga County, NY, Chemung County, NY, Chenango County, NY, Cortland 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, Tioga County, NY, Tompkins County, NY, Yates County, NY

The radar

The Ft Drum radar (KTYX), 45 km from the middle of the area, began a volume at 19:12 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, 7.1 hours before the alert went out and 175 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 2012-05-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 54 joules per kilogram.LCLLFCEL10008507005003002001001 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 2012-05-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 132 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
54 J/kg
Mixed-layer CIN
-49 J/kg
Mixed-layer LCL
523 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
132 m²/s²
0-3 km storm-relative helicity
198 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

191 
ACUS11 KWNS 251908
SWOMCD
SPC MCD 251908 
NYZ000-252045-

MESOSCALE DISCUSSION 0894
NWS STORM PREDICTION CENTER NORMAN OK
0208 PM CDT FRI MAY 25 2012

AREAS AFFECTED...NY

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 251908Z - 252045Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...STORMS MAY INCREASE IN COVERAGE ACROSS PORTIONS OF
NY...FROM THE SRN TIER ACROSS THE FINGER LAKES REGION...OVER THE
NEXT SEVERAL HOURS AS A COLD FRONT MOVES INTO THE STATE FROM THE
WEST. A FEW OF THESE STORMS MAY PRODUCE GUSTY WINDS AND HAIL. A
WATCH MAY BE NEEDED IF SEVERE STORM POTENTIAL BECOMES MORE CERTAIN
IN THE NEXT FEW HOURS.

DISCUSSION...ISOLATED SHOWERS/TSTMS RECENTLY DEVELOPED ALONG A
PRE-FRONTAL TROUGH MOVING ACROSS LAKE ONTARIO AND INTO WRN NY ATTM.
THIS ACTIVITY WAS FURTHER SUPPORTED BY A WEAK SHORT WAVE TROUGH/PV
ANOMALY THAT HAS PEELED OFF THE MUCH STRONGER SYSTEM NOW CROSSING
THE ONTARIO/QUEBEC BORDER IN CANADA. MEANWHILE...A COLD FRONT WAS
MAKING EWD PROGRESS ACROSS SRN ONTARIO AND WILL MOVE TO THE NORTH
SHORE OF LAKE ERIE...AND OVER THE WRN END OF LAKE ONTARIO...IN THE
NEXT COUPLE OF HOURS.

AIRMASS OVER MUCH OF WRN AND CNTRL NY HAS WARMED AND BECOME UNSTABLE
WITH MLCAPE RANGING FROM AOA 1000 J/KG ON THE NY/PA BORDER TO ABOUT
500 J/KG OVER THE ADIRONDACKS WHERE BROKEN CLOUD COVER PERSISTS.
ONGOING SHOWERS/STORMS NOW APPEAR TO BE WEAKENING BUT NEW
DEVELOPMENT IS POSSIBLE NEAR INSTABILITY AXIS OVER THE NEXT 1-2
HOURS PER WRF-HRRR. IT IS LIKELY THAT STRONGER ASCENT WITH THE COLD
FRONT WILL BE REQUIRED TO AID IN THE INITIATION OF MORE
ROBUST/NUMEROUS STORMS LATER THIS AFTERNOON AND INTO EARLY EVENING.

DEEP-LAYER FLOW AND RESULTING VERTICAL SHEAR WILL CONTINUE TO
INCREASE THROUGH THE REST OF THE AFTERNOON. LOW-LEVEL FLOW HAS
ALREADY STRENGTHENED PER BUF VWP WITH 30-35KT SWLY WINDS IN THE
LOWEST 2KM. AMBIENT SHEAR SHOULD SUPPORT THE DEVELOPMENT OF A FEW
SEVERE STORMS IF ADDITIONAL DEVELOPMENT OCCURS ALONG THE ADVANCING
FRONT LATER TODAY. AREA WILL CONTINUE TO BE MONITORED FOR A POSSIBLE
WATCH.

..CARBIN.. 05/25/2012

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

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

LAT...LON   44357462 43847429 43397445 42797501 42267566 42077677
            42157743 42547756 42987741 43347667 44007606 44427531
            44507505 44357462

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.