Alert archive / Pennsylvania / Tornado Watches in 2006

Tornado Watch 756

August 29, 20064 states

The Storm Prediction Center issued this tornado watch at Aug 29, 2006, 1:52 PM EDT for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Aug 29, 2006, 1:52 PM EDT (17:52 UTC)
Expired
Aug 29, 2006, 8:00 PM EDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 50 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Baltimore County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, City of Baltimore, MD, Harford County, MD, Howard County, MD, Kent County, MD, Queen Anne's County, MD, Talbot County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Mercer County, NJ, Ocean County, NJ, Salem County, NJ, Berks County, PA, Bucks County, PA, Carbon County, PA, Centre County, PA, Chester County, PA, Clinton County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Delaware County, PA, Juniata County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Lycoming County, PA, Mifflin County, PA, Montgomery County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Perry County, PA, Philadelphia County, PA, Schuylkill County, PA, Snyder County, PA, Sullivan County, PA, Union County, PA, York County, PA

The radar

The State College radar (KCCX), 150 km from the middle of the area, began a volume at 17:52 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
5%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

17 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Aug 29, 2:04 PM EDTSevere Thunderstorm WarningCTPJuniata, Perry56 min
Aug 29, 2:14 PM EDTSevere Thunderstorm WarningPHIBerks61 min
Aug 29, 2:42 PM EDTFlash Flood WarningPHIBerks3 hr
Aug 29, 2:53 PM EDTSevere Thunderstorm WarningPHIChester, Montgomery52 min
Aug 29, 3:37 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia68 min
Aug 29, 3:39 PM EDTFlash Flood WarningPHIChester3 hr
Aug 29, 3:42 PM EDTSevere Thunderstorm WarningPHINew Castle33 min
Aug 29, 3:50 PM EDTFlash Flood WarningPHIMontgomery3 hr
Aug 29, 4:02 PM EDTTornado WarningPHINew Castle28 min
Aug 29, 4:15 PM EDTFlash Flood WarningPHIPhiladelphia3 hr
Aug 29, 4:28 PM EDTTornado WarningPHINew Castle47 min
Aug 29, 4:45 PM EDTSevere Thunderstorm WarningPHIGloucester60 min
Aug 29, 5:19 PM EDTSevere Thunderstorm WarningPHITalbot56 min
Aug 29, 5:23 PM EDTSevere Thunderstorm WarningPHICumberland67 min
Aug 29, 5:41 PM EDTTornado WarningPHISalem49 min
Aug 29, 5:43 PM EDTFlash Flood WarningPHIBerks2 hr
Aug 29, 6:15 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cape May45 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 5.9 hours before the alert went out and 92 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, Phillips Aaf/Abe, MD at 12:00Z on 2006-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 21 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, Phillips Aaf/Abe, MD at 12:00Z on 2006-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 98 square meters per square second.193958Sfc1 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
21 J/kg
Mixed-layer CIN
-132 J/kg
Mixed-layer LCL
934 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
98 m²/s²
0-3 km storm-relative helicity
185 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 29, 1:31 PM EDTMesoscale DiscussionSPCKent, New Castle, Sussex89 min
Aug 29, 6:25 PM EDTMesoscale DiscussionSPCNew Castle95 min
Aug 29, 3:26 PM EDTMesoscale DiscussionSPCCalvert, Charles, Dorchester, Prince George's, Saint Mary's, Somerset and 3 more94 min

Nearby

Tornado Watches in Pennsylvania, 2006Tornado Watches in Maryland, 2006Tornado Watches in New Jersey, 2006Every tornado watch in 2006

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.