Alert archive / New York / Mesoscale Discussions in 2012

Mesoscale Discussion 1603

July 26, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Jul 26, 2012, 1:50 PM EDT for 4 states. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued
Jul 26, 2012, 1:50 PM EDT (17:50 UTC)
Expired
Jul 26, 2012, 3:45 PM EDT
In force
115 min
Issued by
the Storm Prediction Center
Chance of a watch
95%
All 40 counties

Berkshire County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Albany County, NY, Broome County, NY, Chemung County, NY, Chenango County, NY, Columbia County, NY, Cortland County, NY, Delaware County, NY, Dutchess County, NY, Fulton County, NY, Greene County, NY, Madison County, NY, Montgomery County, NY, Oneida County, NY, Onondaga County, NY, Orange County, NY, Otsego County, NY, Rensselaer County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Schuyler County, NY, Seneca County, NY, Steuben County, NY, Sullivan County, NY, Tioga County, NY, Tompkins County, NY, Ulster County, NY, Yates County, NY, Bradford County, PA, Lackawanna County, PA, Luzerne County, PA, Pike County, PA, Susquehanna County, PA, Wayne County, PA, Wyoming County, PA, Bennington County, VT

The radar

The Binghamton radar (KBGM), 57 km from the middle of the area, began a volume at 17:52 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

Albany, NY (KALY), launched 12:00Z, 5.8 hours before the alert went out and 147 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 2012-07-26Temperature 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 2012-07-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 141 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
991 m above ground
0-6 km bulk shear
65 kt
0-1 km storm-relative helicity
141 m²/s²
0-3 km storm-relative helicity
180 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.

003 
ACUS11 KWNS 261751
SWOMCD
SPC MCD 261750
MAZ000-CTZ000-VTZ000-NYZ000-NJZ000-PAZ000-261945-

MESOSCALE DISCUSSION 1603
NWS STORM PREDICTION CENTER NORMAN OK
1250 PM CDT THU JUL 26 2012

AREAS AFFECTED...PORTIONS SRN/CENTRAL/ERN NY...WRN NEW
ENGLAND...NERN PA.

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 261750Z - 261945Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...BAND OF TSTMS INTENSIFYING OVER NRN PORTIONS WW 524...AND
MOVING EWD ABOUT 40 KT...WILL CONTINUE TO POSE SVR THREAT FARTHER E
ACROSS THIS AREA.  ADDITIONAL DEVELOPMENT IS POSSIBLE ALONG AND EVEN
N OF WARM FRONT AS WELL.  MAIN THREAT IS SVR GUSTS...THOUGH
SUPERCELLS WITH LARGE HAIL ALSO ARE POSSIBLE AND A TORNADO OR TWO
CANNOT BE RULED OUT.

DISCUSSION...17Z SFC MESOANALYSIS SHOWED WARM FRONT OVER
NWRN...CENTRAL AND SERN PA...BECOMING SOMEWHAT DIFFUSE IN THERMAL
FIELDS GIVEN STG SFC DIABATIC HEATING OCCURRING ON BOTH SIDES.  IN
FACT...AIR MASS N OF WARM FRONT HAS BECOME MINIMALLY CAPPED...WITH
SFC DEW POINTS UPPER 60S AND TEMPS LOW 80S F CONTRIBUTING TO MLCAPE
IN 1000-1500 J/KG RANGE.  THIS SHOULD INCREASE TO 2000-2500 J/KG
RANGE BEFORE ARRIVAL OF TSTM BAND.  MLCINH WILL ERODE FROM W-E
ACROSS THIS CORRIDOR DUE TO COMBINATION OF DIABATIC HEATING AND
MOIST ADVECTION...RENDERING AREAS FROM HUDSON VALLEY INTO WRN NEW
ENGLAND FAVORABLY UNSTABLE PRIOR TO CONVECTIVE ARRIVAL...HOWEVER AIR
MASS WILL REMAIN MORE STABLE WITH EWD EXTENT FROM THERE.  GIVEN
STRENGTH OF LOW-LEVEL SPEED SHEAR...HODOGRAPHS WILL REMAIN
RELATIVELY LARGE INVOF SFC WARM FRONT...DESPITE LACK OF APPRECIABLE
VEERING WITH HEIGHT.  DEEP SHEAR WILL REMAIN FAVORABLE AS
WELL...WITH EFFECTIVE SHEAR MAGNITUDES 45-50 KT OVER MOST OF AREA.

..EDWARDS/HART.. 07/26/2012

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

ATTN...WFO...BOX...OKX...ALY...PHI...BGM...BUF...CTP...

LAT...LON   42677758 43367511 43217289 42457243 41937264 41417426
            41317486 41217522 41097559 41157614 41487632 41937668
            42027759 42677758

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 26, 2:10 PM EDTTornado WatchSPCNorthwest Hills Planning Region6 hr
Jul 26, 3:37 PM EDTMesoscale DiscussionSPC113 min
Jul 26, 3:57 PM EDTSevere Thunderstorm WatchSPCGreater Bridgeport Planning Region, Capitol Planning Region, Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region, Southeastern Connecticut Planning Region, Northeastern Connecticut Planning Region6 hr
Jul 26, 6:04 PM EDTMesoscale DiscussionSPC86 min
Jul 26, 7:28 PM EDTMesoscale DiscussionSPC92 min
Jul 26, 1:15 AM EDTMesoscale DiscussionSPCAllegany, Cattaraugus, Chautauqua, Erie, Genesee, Livingston and 4 more2 hr
Jul 26, 4:31 AM EDTMesoscale DiscussionSPCAllegany, Cattaraugus, Chautauqua, Chemung, Livingston, Ontario and 5 more89 min
Jul 26, 12:26 PM EDTMesoscale DiscussionSPCAllegany, Cattaraugus, Chautauqua, Chemung, Schuyler, Steuben2 hr
Jul 26, 1:16 PM EDTSevere Thunderstorm WatchSPCAllegany, Cattaraugus, Chautauqua9 hr
Jul 26, 6:06 PM EDTMesoscale DiscussionSPCAllegheny, Fayette, Greene, Somerset, Washington, Westmoreland84 min

Nearby

Mesoscale Discussions in New York, 2012Mesoscale Discussions in Pennsylvania, 2012Mesoscale Discussions in Massachusetts, 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.