Alert archive / Pennsylvania / Mesoscale Discussions in 2004

Mesoscale Discussion 1413

June 24, 2004Belmont County, Jefferson County, Ohio; 20 counties in Pennsylvania; Brooke County, Hancock County, Ohio County, West Virginia

The Storm Prediction Center issued this mesoscale discussion at Jun 24, 2004, 7:44 PM EDT for Belmont County, Jefferson County, Ohio; 20 counties in Pennsylvania; Brooke County, Hancock County, Ohio County, West Virginia. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 24, 2004, 7:44 PM EDT (23:44 UTC)
Expired
Jun 24, 2004, 9:45 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
All 25 counties

Belmont County, OH, Jefferson County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Cambria County, PA, Cameron County, PA, Clarion County, PA, Clearfield County, PA, Crawford County, PA, Elk County, PA, Forest County, PA, Indiana County, PA, Jefferson County, PA, Lawrence County, PA, McKean County, PA, Mercer County, PA, Venango County, PA, Warren County, PA, Washington County, PA, Westmoreland County, PA, Brooke County, WV, Hancock County, WV, Ohio County, WV

The radar

The Pittsburgh radar (KPBZ), 31 km from the middle of the area, began a volume at 23:45 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, 11.7 hours before the alert went out and 40 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 2004-06-24Temperature 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, Pittsburgh, PA at 12:00Z on 2004-06-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 131 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1552 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
131 m²/s²
0-3 km storm-relative helicity
128 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.

016 
ACUS11 KWNS 242345
SWOMCD
SPC MCD 242344 
PAZ000-NYZ000-WVZ000-OHZ000-250145-

MESOSCALE DISCUSSION 1413
NWS STORM PREDICTION CENTER NORMAN OK
0644 PM CDT THU JUN 24 2004

AREAS AFFECTED...EXTREME WRN NY STATE..WRN AND CENTRAL PA...E
CENTRAL OH AND THE NRN WV PANHANDLE

CONCERNING...SEVERE THUNDERSTORM WATCH 519...

VALID 242344Z - 250145Z

SQUALL LINE CONTINUE TO PROGRESS EWD ACROSS NERN OH AT 30-40 KT.  WE
ARE MONITORING THIS AREA FOR AN ADDITIONAL WW WITHIN THE NEXT HOUR.

SQUALL LINE HAS A HISTORY OF DAMAGING WINDS AND SOME HAIL AS IT
MOVED ACROSS NERN AND N CENTRAL OH.  MLCAPE VALUES ARE RUNNING
BETWEEN 1000 AND 1500 J/KG AHEAD OF THE LINE.  MAIN ADVANCEMENT OF
THE STRONG COLD FRONT IS EWD ACROSS NERN OH INTO NWRN PA AND WRN NY
WHICH WOULD PLACE THE LEADING ACTIVITY INTO THIS AREA WITHIN THE
NEXT HOUR OR SO. SURFACE TEMPS IN THE MID 70S TO LOWER 80S..AND DEW
POINTS IN THE LOW 60S AHEAD OF THE FRONT CONTINUE TO BE FAVORABLE TO
SUPPORT STRONG/SEVERE STORMS THE NEXT FEW HOURS.  LOSS OF DAYTIME
HEATING WILL DECREASE POTENTIAL INSTABILITY...BUT WITH ADVANCING
COLD FRONT...DAMAGING WINDS WILL REMAIN A CONCERN ACROSS THIS
REGION.

..MCCARTHY.. 06/24/2004

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

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

39988140 40258110 40938060 41848025 42327930 41997810
41047794 40317894 39898004 39848111

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 24, 3:11 PM EDTMesoscale DiscussionSPCAllen, Ashland, Ashtabula, Auglaize, Champaign, Clark and 34 more94 min
Jun 24, 4:05 PM EDTSevere Thunderstorm WatchSPCAllen, Ashland, Auglaize, Carroll, Champaign, Clark and 35 more6 hr

Nearby

Mesoscale Discussions in Pennsylvania, 2004Mesoscale Discussions in West Virginia, 2004Mesoscale Discussions in Ohio, 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.