Alert archive / Pennsylvania / Flash Flood Warnings in 1999

Flash Flood Warning 56, NWS Pittsburgh, PA

July 29, 1999Lawrence County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Jul 29, 1999, 1:16 AM EDT for Lawrence County, Pennsylvania. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 29, 1999, 1:16 AM EDT (05:16 UTC)
Expired
Jul 29, 1999, 4:15 AM EDT
In force
3 hr
Issued by
NWS Pittsburgh, PA
Area
Whole counties

County Lawrence County, PA

The radar

The Pittsburgh radar (KPBZ), 52 km from the middle of the area, began a volume at 05:16 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 nearest sounding before it

Pittsburgh, PA (KPIT), launched 00:00Z, 5.3 hours before the alert went out and 68 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 00:00Z on 1999-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 180 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 00:00Z on 1999-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 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
180 J/kg
Mixed-layer CIN
-196 J/kg
Mixed-layer LCL
952 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
94 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

The office that day

Everything else NWS Pittsburgh, PA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 29, 12:41 AM EDTSevere Thunderstorm WarningPBZLawrence64 min
Jul 29, 12:57 AM EDTSevere Thunderstorm WarningPBZButler, Lawrence63 min
Jul 29, 2:00 AM EDTFlash Flood WarningPBZAllegheny, Beaver3 hr
Jul 29, 12:34 AM EDTSevere Thunderstorm WarningPBZColumbiana56 min
Jul 29, 1:23 AM EDTSevere Thunderstorm WarningPBZColumbiana67 min
Jul 29, 1:30 AM EDTSevere Thunderstorm WarningPBZCarroll60 min
Jul 29, 2:26 AM EDTSevere Thunderstorm WarningPBZCoshocton, Muskingum64 min
Jul 29, 3:04 AM EDTSevere Thunderstorm WarningPBZHarrison, Jefferson56 min
Jul 29, 4:57 AM EDTSevere Thunderstorm WarningPBZCarroll63 min
Jul 29, 5:27 AM EDTSevere Thunderstorm WarningPBZJefferson63 min

Nearby

Flash Flood Warnings in Pennsylvania, 1999Every flash flood warning in 1999

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.