Alert archive / West Virginia / Mesoscale Discussions in 2004

Mesoscale Discussion 910

May 26, 2004Allegany County, Garrett County, Maryland; 29 counties in Pennsylvania; 32 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at May 26, 2004, 12:55 PM EDT for Allegany County, Garrett County, Maryland; 29 counties in Pennsylvania; 32 counties in West Virginia. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
May 26, 2004, 12:55 PM EDT (16:55 UTC)
Expired
May 26, 2004, 2:30 PM EDT
In force
95 min
Issued by
the Storm Prediction Center
All 63 counties

Allegany County, MD, Garrett County, MD, Allegheny County, PA, Armstrong County, PA, Bedford County, PA, Blair County, PA, Bradford County, PA, Cambria County, PA, Cameron County, PA, Centre County, PA, Clarion County, PA, Clearfield County, PA, Clinton County, PA, Elk County, PA, Fayette County, PA, Fulton County, PA, Greene County, PA, Huntingdon County, PA, Indiana County, PA, Jefferson County, PA, Juniata County, PA, Lycoming County, PA, Mifflin County, PA, Potter County, PA, Snyder County, PA, Somerset County, PA, Sullivan County, PA, Tioga County, PA, Union County, PA, Washington County, PA, Westmoreland County, PA, Barbour County, WV, Braxton County, WV, Calhoun County, WV, Clay County, WV, Doddridge County, WV, Fayette County, WV, Gilmer County, WV, Grant County, WV, Greenbrier County, WV, Harrison County, WV, Jackson County, WV, Kanawha County, WV, Lewis County, WV, Marion County, WV, Marshall County, WV, Mineral County, WV, Monongalia County, WV, Nicholas County, WV, Pleasants County, WV, Pocahontas County, WV, Preston County, WV, Putnam County, WV, Randolph County, WV, Ritchie County, WV, Roane County, WV, Taylor County, WV, Tucker County, WV, Tyler County, WV, Upshur County, WV, Webster County, WV, Wetzel County, WV, Wirt County, WV

The radar

The Pittsburgh radar (KPBZ), 94 km from the middle of the area, began a volume at 16:56 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

Pittsburgh, PA (KPIT), launched 12:00Z, 4.9 hours before the alert went out and 78 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 12:00Z on 2004-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 372 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 12:00Z on 2004-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 105 square meters per square second.1939587897Sfc1 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
372 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
678 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
105 m²/s²
0-3 km storm-relative helicity
128 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.8

Open this sounding in Storm Lab

The text

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

005 
ACUS11 KWNS 261655
SWOMCD
SPC MCD 261655 
PAZ000-MDZ000-WVZ000-VAZ000-OHZ000-261830-

MESOSCALE DISCUSSION 0910
NWS STORM PREDICTION CENTER NORMAN OK
1155 AM CDT WED MAY 26 2004

AREAS AFFECTED...WRN/CNTRL PA SWD INTO WV/WRN MD

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 261655Z - 261830Z

TSTMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY THIS
AFTERNOON AND CONVECTIVE TRENDS WILL BE MONITORED FOR POSSIBLE WW
ISSUANCE.

OVER THE PAST HALF HOUR...DEEPER CONVECTIVE ELEMENTS HAVE DEVELOPED
OVER ARMSTRONG AND BUTLER COUNTIES OF WRN PA WITH ADDITIONAL MORE
MATURE CONVECTIVE ACTIVITY FARTHER S OVER EXTREME SERN OH AND WRN
WV. THOUGH HIGH-LEVEL CLOUDS HAVE SLOWED DAYTIME HEATING...
MESOANALYSIS SHOWS TEMPERATURES WARMING THROUGH THE 70S AHEAD OF
WEAK COLD FRONT/WIND SHIFT THAT EXTENDED FROM EXTREME PA INTO CNTRL
OH AS OF 16Z.

CONTINUED HEATING/MOISTENING OF PRE-FRONTAL AIRMASS WILL AID IN
ADDITIONAL DESTABILIZATION THROUGH THE AFTERNOON HOURS WITH MLCAPES
APPROACHING 1000-1500 J/KG. MOREOVER...INCREASED FORCING FOR ASCENT
AHEAD OF SHORTWAVE TROUGH MOVING ACROSS SRN IL/IND SHOULD PROMOTE AN
INCREASE IN STORM COVERAGE AND INTENSITY. RELATIVELY STRONG AND DEEP
UNIDIRECTIONAL WIND FIELDS WILL SUPPORT ORGANIZED TSTMS CAPABLE OF
ISOLATED LARGE HAIL AND DAMAGING WINDS. CONVECTIVE TRENDS WILL
CONTINUE TO BE MONITORED AND A WW MAY BE REQUIRED IN THE NEXT COUPLE
OF HOURS.

..MEAD.. 05/26/2004

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

ATTN...WFO...BGM...CTP...LWX...RNK...PBZ...RLX...

39098162 41037968 41977833 41807614 40387730 38777935
37848050 38318219

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 25, 9:50 PM EDTMesoscale DiscussionSPCCalvert, Caroline, Dorchester, Queen Anne's, Saint Mary's, Somerset and 3 more55 min
May 26, 5:15 PM EDTMesoscale DiscussionSPCCarroll2 hr
May 26, 5:45 PM EDTSevere Thunderstorm WatchSPCAnne Arundel, Baltimore, Calvert, Carroll, Cecil, Charles and 11 more5 hr
May 26, 12:25 PM EDTSevere Thunderstorm WatchSPCMason7 hr
May 26, 1:38 PM EDTMesoscale DiscussionSPCBoone, Braxton, Calhoun, Clay, Fayette, Gilmer and 23 more97 min
May 26, 2:18 PM EDTMesoscale DiscussionSPCMason87 min
May 26, 2:50 PM EDTSevere Thunderstorm WatchSPCBarbour, Boone, Braxton, Cabell, Calhoun, Clay and 38 more7 hr

Nearby

Mesoscale Discussions in West Virginia, 2004Mesoscale Discussions in Pennsylvania, 2004Mesoscale Discussions in Maryland, 2004Every mesoscale discussion in 2004

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.