Alert archive / Pennsylvania / Severe Thunderstorm Watches in 2004
Severe Thunderstorm Watch 708
The Storm Prediction Center issued this severe thunderstorm watch at Aug 4, 2004, 2:55 PM EDT for 4 states. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 4, 2004, 2:55 PM EDT (18:55 UTC)
- Expired
- Aug 4, 2004, 9:00 PM EDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 44 counties
Allegany County, MD, Carroll County, MD, Frederick County, MD, Garrett County, MD, Washington County, MD, Adams County, PA, Bedford County, PA, Blair County, PA, Cambria County, PA, Carbon County, PA, Centre County, PA, Clearfield County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Fayette County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Juniata County, PA, Lebanon County, PA, Luzerne County, PA, Mifflin County, PA, Montour County, PA, Northumberland County, PA, Perry County, PA, Schuylkill County, PA, Snyder County, PA, Somerset County, PA, Union County, PA, York County, PA, City of Winchester, VA, Clarke County, VA, Frederick County, VA, Barbour County, WV, Berkeley County, WV, Grant County, WV, Hampshire County, WV, Jefferson County, WV, Mineral County, WV, Morgan County, WV, Preston County, WV, Taylor County, WV, Tucker County, WV
The radar
The State College radar (KCCX), 113 km from the middle of the area, began a volume at 18:55 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.
Warnings issued inside it
22 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 4, 3:12 PM EDT | Severe Thunderstorm Warning | PBZ | Preston | 63 min |
| Aug 4, 3:22 PM EDT | Severe Thunderstorm Warning | CTP | Cambria, Somerset | 53 min |
| Aug 4, 3:42 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 63 min |
| Aug 4, 3:57 PM EDT | Severe Thunderstorm Warning | CTP | Centre | 63 min |
| Aug 4, 4:02 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 58 min |
| Aug 4, 4:09 PM EDT | Severe Thunderstorm Warning | CTP | Bedford, Blair, Cambria, Somerset | 66 min |
| Aug 4, 4:20 PM EDT | Severe Thunderstorm Warning | CTP | Juniata, Perry | 55 min |
| Aug 4, 4:24 PM EDT | Severe Thunderstorm Warning | CTP | Mifflin | 36 min |
| Aug 4, 4:41 PM EDT | Severe Thunderstorm Warning | CTP | Huntingdon | 64 min |
| Aug 4, 4:45 PM EDT | Severe Thunderstorm Warning | CTP | Snyder, Union | 60 min |
| Aug 4, 4:54 PM EDT | Severe Thunderstorm Warning | CTP | Fulton | 36 min |
| Aug 4, 5:13 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 62 min |
| Aug 4, 5:14 PM EDT | Severe Thunderstorm Warning | CTP | Juniata, Perry | 61 min |
| Aug 4, 5:19 PM EDT | Severe Thunderstorm Warning | CTP | Franklin | 71 min |
| Aug 4, 5:25 PM EDT | Severe Thunderstorm Warning | CTP | Dauphin, Northumberland | 65 min |
| Aug 4, 5:43 PM EDT | Severe Thunderstorm Warning | CTP | Cumberland | 62 min |
| Aug 4, 6:02 PM EDT | Tornado Warning | CTP | Cumberland, Dauphin | 43 min |
| Aug 4, 6:06 PM EDT | Severe Thunderstorm Warning | CTP | York | 54 min |
| Aug 4, 6:12 PM EDT | Tornado Warning | CTP | York | 48 min |
| Aug 4, 6:17 PM EDT | Severe Thunderstorm Warning | CTP | Lancaster, Lebanon | 73 min |
| Aug 4, 6:21 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick | 54 min |
| Aug 4, 6:58 PM EDT | Tornado Warning | CTP | York | 32 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 6.9 hours before the alert went out and 141 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.
- Mixed-layer CAPE
- 24 J/kg
- Mixed-layer CIN
- -92 J/kg
- Mixed-layer LCL
- 1125 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- -2 m²/s²
- 0-3 km storm-relative helicity
- -4 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
WWUS20 KWNS 041853
SEL8
SPC WW 041855
MDZ000-PAZ000-VAZ000-WVZ000-050100-
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 708
NWS STORM PREDICTION CENTER NORMAN OK
255 PM EDT WED AUG 4 2004
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
WESTERN AND CENTRAL MARYLAND
CENTRAL PENNSYLVANIA
EXTREME NORTHERN VIRGINIA
EASTERN WEST VIRGINIA PANHANDLE
EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 255 PM UNTIL
900 PM EDT.
HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 80 STATUTE MILES
EAST AND WEST OF A LINE FROM 70 MILES NORTH OF HARRISBURG
PENNSYLVANIA TO 55 MILES WEST SOUTHWEST OF MARTINSBURG WEST
VIRGINIA.
REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA.
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.
OTHER WATCH INFORMATION...CONTINUE...WW 706...WW 707...
DISCUSSION...LINE OF SEVERE STORMS OVER WESTERN PA IS EXPECTED TO
MAINTAIN INTENSITY AS IT CROSSES THE MOUNTAINS INTO CENTRAL
PA/EASTERN WV PANHANDLE/WESTERN MD. MOIST/UNSTABLE AIRMASS AND
SUFFICIENT WESTERLY MID LEVEL WINDS SUGGEST A CONTINUED THREAT OF
DAMAGING WINDS AND LARGE HAIL WITH STRONGER CELLS.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 27035.
...HART
411,0751 390,0772 390,0802 411,0782SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 4, 2:31 PM EDT | Mesoscale Discussion | SPC | Allegany, Garrett, Washington | 119 min |
| Aug 4, 5:48 PM EDT | Mesoscale Discussion | SPC | Baltimore, Carroll, Cecil, Frederick, Harford, Howard and 5 more | 117 min |
| Aug 4, 7:10 PM EDT | Severe Thunderstorm Watch | SPC | Anne Arundel, Baltimore, Caroline, Cecil, Harford, Howard and 6 more | 4 hr |
| Aug 4, 10:39 AM EDT | Mesoscale Discussion | SPC | Allegheny, Beaver, Fayette, Greene, Washington, Westmoreland | 2 hr |
| Aug 4, 11:55 AM EDT | Severe Thunderstorm Watch | SPC | Allegheny, Armstrong, Beaver, Butler, Clarion, Fayette and 8 more | 5 hr |
| Aug 4, 2:30 PM EDT | Severe Thunderstorm Watch | SPC | Bland, Buchanan, Dickenson, Tazewell, Wise | 6 hr |
| Aug 4, 4:39 PM EDT | Mesoscale Discussion | SPC | Buchanan, Dickenson, Russell, Tazewell, Wise, City of Norton | 96 min |
| Aug 4, 2:01 PM EDT | Mesoscale Discussion | SPC | Boone, Cabell, Kanawha, Lincoln, Logan, Mason and 3 more | 89 min |
Nearby
Severe Thunderstorm Watches in Pennsylvania, 2004Severe Thunderstorm Watches in West Virginia, 2004Severe Thunderstorm Watches in Maryland, 2004Every severe thunderstorm watch 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.