Alert archive / West Virginia / Mesoscale Discussions in 2012

Mesoscale Discussion 190

February 29, 201223 counties in Ohio; 5 counties in Pennsylvania; 39 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at Feb 29, 2012, 7:30 PM EST for 23 counties in Ohio; 5 counties in Pennsylvania; 39 counties in West Virginia. It was in force for 30 min.

The area

The outline as issued.

The facts

Issued
Feb 29, 2012, 7:30 PM EST (00:30 UTC)
Expired
Feb 29, 2012, 8:00 PM EST
In force
30 min
Issued by
the Storm Prediction Center
All 67 counties

Athens County, OH, Belmont County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Gallia County, OH, Guernsey County, OH, Harrison County, OH, Holmes County, OH, Jefferson County, OH, Mahoning County, OH, Meigs County, OH, Monroe County, OH, Morgan County, OH, Muskingum County, OH, Noble County, OH, Portage County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Tuscarawas County, OH, Washington County, OH, Wayne County, OH, Beaver County, PA, Greene County, PA, Lawrence County, PA, Mercer County, PA, Washington County, PA, Barbour County, WV, Boone County, WV, Braxton County, WV, Brooke County, WV, Cabell County, WV, Calhoun County, WV, Clay County, WV, Doddridge County, WV, Fayette County, WV, Gilmer County, WV, Hancock County, WV, Harrison County, WV, Jackson County, WV, Kanawha County, WV, Lewis County, WV, Lincoln County, WV, Logan County, WV, Marion County, WV, Marshall County, WV, Mason County, WV, Monongalia County, WV, Nicholas County, WV, Ohio County, WV, Pleasants County, WV, Pocahontas County, WV, Putnam County, WV, Raleigh County, WV, Randolph County, WV, Ritchie County, WV, Roane County, WV, Taylor County, WV, Tyler County, WV, Upshur County, WV, Wayne County, WV, Webster County, WV, Wetzel County, WV, Wirt County, WV, Wood County, WV, Wyoming County, WV

The radar

The Charleston,WV radar (KRLX), 99 km from the middle of the area, began a volume at 00:30 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

Pittsburgh, PA (KPIT), launched 00:00Z, 0.5 hours before the alert went out and 178 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, Pittsburgh, PA at 00:00Z on 2012-03-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 377 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, Pittsburgh, PA at 00:00Z on 2012-03-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 120 square meters per square second.1939587897117136Sfc1 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
377 J/kg
Mixed-layer CIN
-40 J/kg
Mixed-layer LCL
848 m above ground
0-6 km bulk shear
98 kt
0-1 km storm-relative helicity
120 m²/s²
0-3 km storm-relative helicity
152 m²/s²
Significant tornado parameter
0.4
Supercell composite
1.6

Open this sounding in Storm Lab

The text

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

512 
ACUS11 KWNS 010031
SWOMCD
SPC MCD 010030
PAZ000-WVZ000-OHZ000-KYZ000-010100-

MESOSCALE DISCUSSION 0190
NWS STORM PREDICTION CENTER NORMAN OK
0630 PM CST WED FEB 29 2012

AREAS AFFECTED...SERN AND ERN OH / MUCH OF WV

CONCERNING...TORNADO WATCH 49...

VALID 010030Z - 010100Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 49 CONTINUES.

THE SEVERE THREAT AND CORRESPONDING TORNADO RISK HAVE DIMINISHED
CONSIDERABLY ACROSS THE UPPER OH VALLEY REGION.  BOUNDARY LAYER
DESTABILIZATION COINCIDENT WITH LOSS OF DAYTIME HEATING WILL ACT TO
STRONGLY DIMINISH ANY REMAINING STRONG TO SEVERE TSTM RISK --WW 49
MAY BE ALLOWED TO EXPIRE PRIOR TO 02Z EXPIRATION TIME.

LATEST SURFACE ANALYSIS SHOWS A PLUME OF HIGHER LOW LEVEL MOISTURE
/CHARACTERIZED BY DEWPOINTS RANGING FROM 50 DEG N TO UPPER 50S S/
AHEAD OF A DRYLINE-LIKE FEATURE EXTENDING SW-NE NEAR THE I-71
CORRIDOR IN OHIO.  WEAK SURFACE-BASED CAPE /AOB 500 J/KG PER PIT
RAOB/-- WITHIN AN OTHERWISE STRONG SHEAR ENVIRONMENT-- WILL CONTINUE
TO LESSEN WITH TIME.  RADAR MOSAIC AND VISIBLE SATELLITE TRENDS HAVE
SHOWN LITTLE IN THE WAY OF DEEPENING CONVECTIVE DEVELOPMENT ACROSS
ERN OH --EXCEPT ACROSS NERN OH WHERE A FEW LOW TOPPED TSTMS HAVE
DEVELOPED IN THE PAST HR.  ASIDE FROM STRENGTHENING ASCENT
--ASSOCIATED WITH A MID-LEVEL VORT LOBE PROGRESSING ACROSS IND INTO
OHIO-- THAT MAY ACT TO PROLONG TSTM ACTIVITY ACROSS NERN OHIO INTO
NWRN PA...STORM COVERAGE IS ANTICIPATED TO BE LOW THROUGH THE EARLY
EVENING.

..SMITH.. 03/01/2012

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

ATTN...WFO...RNK...PBZ...RLX...CLE...ILN...

LAT...LON   38298259 41278181 41478023 38377978 37368158 38298259

Nearby

Mesoscale Discussions in West Virginia, 2012Mesoscale Discussions in Ohio, 2012Mesoscale Discussions in Pennsylvania, 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.