Alert archive / Pennsylvania / Tornado Watches in 2005
Tornado Watch 763
The Storm Prediction Center issued this tornado watch at Aug 31, 2005, 2:55 AM EDT for 9 counties in New York; 40 counties in Pennsylvania. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 31, 2005, 2:55 AM EDT (06:55 UTC)
- Expired
- Aug 31, 2005, 9:00 AM EDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 49 counties
Allegany County, NY, Broome County, NY, Chemung County, NY, Chenango County, NY, Delaware County, NY, Schuyler County, NY, Steuben County, NY, Tioga County, NY, Tompkins County, NY, Adams County, PA, Bedford County, PA, Berks County, PA, Blair County, PA, Bradford County, PA, Cambria County, PA, Cameron County, PA, Carbon County, PA, Centre County, PA, Clearfield County, PA, Clinton County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Juniata County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Lycoming County, PA, Mifflin County, PA, Monroe County, PA, Montour County, PA, Northumberland County, PA, Perry County, PA, Potter County, PA, Schuylkill County, PA, Snyder County, PA, Somerset County, PA, Sullivan County, PA, Susquehanna County, PA, Tioga County, PA, Union County, PA, Wayne County, PA, Wyoming County, PA, York County, PA
The radar
The State College radar (KCCX), 53 km from the middle of the area, began a volume at 06:58 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
5 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 31, 4:54 AM EDT | Severe Thunderstorm Warning | BGM | Chemung, Steuben | 41 min |
| Aug 31, 5:52 AM EDT | Severe Thunderstorm Warning | BGM | Bradford, Susquehanna | 53 min |
| Aug 31, 6:21 AM EDT | Severe Thunderstorm Warning | BGM | Broome | 39 min |
| Aug 31, 6:43 AM EDT | Severe Thunderstorm Warning | BGM | Susquehanna | 24 min |
| Aug 31, 6:50 AM EDT | Severe Thunderstorm Warning | BGM | Broome, Chenango | 40 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 00:00Z, 6.9 hours before the alert went out and 218 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
- 1575 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 666 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 129 m²/s²
- 0-3 km storm-relative helicity
- 273 m²/s²
- Significant tornado parameter
- 2.5
- Supercell composite
- 12.8
The text
As transmitted, in the capitals the NWS used until 2016.
000
WWUS20 KWNS 310654
SEL3
SPC WW 310654
NYZ000-PAZ000-311300-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 763
NWS STORM PREDICTION CENTER NORMAN OK
255 AM EDT WED AUG 31 2005
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTH CENTRAL NEW YORK
CENTRAL AND EASTERN PENNSYLVANIA
EFFECTIVE THIS WEDNESDAY MORNING FROM 255 AM UNTIL 900 AM EDT.
TORNADOES...THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS
LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 90 STATUTE MILES
EAST AND WEST OF A LINE FROM 50 MILES SOUTHEAST OF ALTOONA
PENNSYLVANIA TO 20 MILES EAST NORTHEAST OF ITHACA NEW YORK. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU3).
REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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.
DISCUSSION...THUNDERSTORMS ARE PERSISTING/INCREASING OVER CENTRAL PA
EARLY THIS MORNING WITHIN AN ENVIRONMENT CHARACTERIZED BY MARGINAL
INSTABILITY AND VERY STRONG LOW LEVEL SHEAR. DESPITE THE LIMITED
SBCAPE...CHARACTER OF STORMS AND AMOUNT OF CG-LIGHTNING CURRENTLY
OCCURRING SUGGESTS INSTABILITY IS SUFFICIENT TO SUSTAIN ERECT
UPDRAFTS. EXTREME SHEAR FROM REMNANTS OF KATRINA WILL SUSTAIN SMALL
LINES AND SUPERCELLS WITH THE THREATS OF DAMAGING WINDS AND ISOLATED
TORNADOES. TORNADO THREAT MAY BE MORE LIMITED INTO S-CENTRAL NY
ATTM...GIVEN MORE LIMITED INSTABILITY. HOWEVER...SHOULD WARM/MOIST
BOUNDARY LAYER AIR PUSH NWD LATER THIS MORNING...THEN TORNADO THREAT
MAY INCREASE NWD WITH TIME.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH EXTREME
TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI
WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION VECTOR 22035.
...EVANS
394,0791 423,0775 423,0741 394,0755SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 31, 2:47 AM EDT | Mesoscale Discussion | SPC | Allegany, Broome, Chemung, Chenango, Cortland, Schuyler and 4 more | 88 min |
| Aug 31, 7:22 AM EDT | Mesoscale Discussion | SPC | Albany, Broome, Chemung, Chenango, Columbia, Cortland and 11 more | 83 min |
| Aug 31, 2:40 PM EDT | Mesoscale Discussion | SPC | Rensselaer, Saratoga, Schenectady, Washington | 95 min |
| Aug 30, 10:19 PM EDT | Mesoscale Discussion | SPC | Adams, Berks, Carbon, Chester, Cumberland, Dauphin and 9 more | 116 min |
Nearby
Tornado Watches in Pennsylvania, 2005Tornado Watches in New York, 2005Every tornado watch in 2005
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.