Mesoscale Discussion 1380

Issued

Jul 3, 2012, 7:40 PM EDT (23:40 UTC)

Expired

Jul 3, 2012, 9:45 PM EDT

In force

2 hr

Issued by

the Storm Prediction Center

Chance of a watch

20%

The Cleveland radar (KCLE), 68 km from the middle of the area, began a volume at 23:43 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

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129 
ACUS11 KWNS 032341
SWOMCD
SPC MCD 032340
PAZ000-NYZ000-OHZ000-040145-

MESOSCALE DISCUSSION 1380
NWS STORM PREDICTION CENTER NORMAN OK
0640 PM CDT TUE JUL 03 2012

AREAS AFFECTED...NRN OH...NWRN PA...SWRN NY

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 032340Z - 040145Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...AN ISOLATED SVR THREAT WILL EXIST INTO THE EVENING WITH
CONVECTION APPROACHING THE SHORELINE OF LAKE ERIE. THE ISSUANCE OF A
WW IS UNLIKELY.

DISCUSSION...CLUSTERS OF CONVECTION DEVELOPED EARLIER IN SERN LOWER
MI IN ASSOCIATION WITH A LOBE OF MID-LEVEL ASCENT -- INFERRED FROM
WATER VAPOR IMAGERY -- THAT CROSSED A CONVECTIVELY AUGMENTED SFC
BAROCLINIC ZONE ORIENTED NNW-SSE FROM SERN LOWER MI TO NEAR
MANSFIELD OH TO NEAR ZANESVILLE OH. THE INCREASING MID-LEVEL ASCENT
AMIDST A CONDITIONALLY UNSTABLE ENVIRONMENT HAS ALLOWED THESE
CONVECTIVE CLUSTERS TO GROW IN SPATIAL EXTENT OVER LAKE ERIE AND
ADJACENT ONTARIO...THOUGH RADAR IMAGERY SUGGESTS CONVECTION HAS
REMAINED GENERALLY DISORGANIZED. THIS DISORGANIZATION MAY BE PARTLY
THE RESULT OF EARLIER CONVECTIVE OVERTURNING IN ASSOCIATION WITH
STORMS THAT CROSSED LAKE ERIE DURING THE MORNING HOURS.

HOWEVER...INSOLATION FOLLOWING THE EARLIER ACTIVITY HAS LIKELY
CONTRIBUTED TO PARTIAL EROSION OF THE CONVECTIVELY GENERATED STABLE
LAYER...PARTICULARLY OVER THE COUPLE TIERS OF COUNTIES CLOSEST TO
THE LAKESHORE IN OHIO...WHERE AIR MASS RECOVERY HAS BEEN THE MOST
PROLONGED. MODIFIED RAPID REFRESH SOUNDINGS SUGGEST THAT UPWARDS OF
AROUND 1000 J/KG OF MLCAPE IS IN PLACE IN THESE AREAS...THOUGH SOME
INHIBITION PROBABLY REMAINS. AND...WITH A WARMER/MORE DEEPLY MIXED
BOUNDARY LAYER ACROSS WRN OH BEING ADVECTED ATOP THE NEAR-SFC COOL
DOME...STORM INTENSITY MAY BE MAINTAINED AHEAD OF ONGOING ACTIVITY
CURRENTLY APPROACHING THE LAKESHORE.

MODERATE WNWLY MID-LEVEL FLOW SUPPORTING 25-40 KT OF EFFECTIVE BULK
SHEAR MAY YIELD OCCASIONALLY ORGANIZED STORM STRUCTURES/BOWING
SEGMENTS WITH A MARGINALLY SVR WIND THREAT. MARGINALLY SVR HAIL
CANNOT BE RULED OUT WITH THE STRONGEST CORES. HOWEVER...CONCERNS
REGARDING REMAINING INHIBITION -- FORECAST TO INCREASE WITH
NOCTURNAL DIABATIC COOLING -- WILL LIKELY PREVENT A MORE SUBSTANTIAL
SVR THREAT FROM EVOLVING.

..COHEN/HART.. 07/03/2012

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

ATTN...WFO...BUF...CTP...PBZ...CLE...

LAT...LON   42208081 42477998 42517894 42107870 41517889 41167952
            40908031 40718166 40788280 41128344 41468368 41648354
            41918224 42208081

Mesoscale Discussions in Ohio, 2012Mesoscale Discussions in Pennsylvania, 2012Mesoscale Discussions in New York, 2012Every mesoscale discussion in 2012

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.