Alert archive / Pennsylvania / Flash Flood Warnings in 1999
Flash Flood Warning 15, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Mar 22, 1999, 12:19 AM EST for 4 counties in 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
- Mar 22, 1999, 12:19 AM EST (05:19 UTC)
- Expired
- Mar 22, 1999, 3:20 AM EST
- In force
- 3 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Whole counties
Counties Bucks County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 00:00Z, 5.3 hours before the alert went out and 225 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 499 m above ground
- 0-6 km bulk shear
- 58 kt
- 0-1 km storm-relative helicity
- -185 m²/s²
- 0-3 km storm-relative helicity
- -252 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KPHL 220520 FFWPHL PAC011-017-025-029-045-077-089-091-095-101-220820- BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1219 AM EST MON MAR 22 1999 THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A * FLASH FLOOD WARNING FOR... CARBON COUNTY IN PENNSYLVANIA. MONROE COUNTY IN PENNSYLVANIA. BERKS COUNTY IN PENNSYLVANIA. LEHIGH COUNTY IN PENNSYLVANIA. NORTHAMPTON COUNTY IN PENNSYLVANIA. CHESTER COUNTY IN PENNSYLVANIA. MONTGOMERY COUNTY IN PENNSYLVANIA. BUCKS COUNTY IN PENNSYLVANIA. DELAWARE COUNTY IN PENNSYLVANIA. PHILADELPHIA COUNTY IN PENNSYLVNAIA * UNTIL 320 AM EST. * THIS FLASH FLOOD WARNING REPLACES ALL OTHERS THAT WERE PREVIOUSLY ISSUED EARLIER TONIGHT AND NOW ALSO INCLUDES DELAWARE AND NORTHAMPTON COUNTIES. AT MIDNIGHT...HEAVY RAINS OF 1 TO 2 INCHES HAVE FALLEN THROUGHOUT MUCH OF EASTERN PENNSYLVANIA. LOCAL AMOUNTS OF 4 INCHES ARE ALSO POSSIBLE. POOR DRAINAGE AREAS AND SOME SMALL STREAMS HAVE ALREADY FLOODED... INCLUDING THE EAST BRANCH OF THE PERKIOMEN CREEK IN PARTS OF BUCKS AND MONTGOMERY COUNTIES. THE HEAVIEST RAINS WILL MOVE OUT OF THE AREA BY 2 AM...HOWEVER... LIGHTER RAIN WILL CONTINUE INTO THE EARLY MORNING HOURS. DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY. MOVE TO HIGHER GROUND. FOR THE LATEST STORM INFORMATION...PLEASE TUNE TO NOAA WEATHER RADIO...YOUR LOCAL RADIO OR TELEVISION STATIONS...OR YOUR CABLE TELEVISION OUTLET. .END RNS
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 21, 7:57 PM EST | Flash Flood Warning | PHI | Chester | 6 hr |
| Mar 21, 9:10 PM EST | Flash Flood Warning | PHI | Berks | 5 hr |
| Mar 21, 9:40 PM EST | Flash Flood Warning | PHI | Carbon, Lehigh, Monroe | 4 hr |
| Mar 21, 10:34 PM EST | Flash Flood Warning | PHI | Montgomery | 3 hr |
| Mar 21, 11:15 PM EST | Flash Flood Warning | PHI | Bucks | 3 hr |
| Mar 21, 11:50 PM EST | Flash Flood Warning | PHI | Philadelphia | 3 hr |
| Mar 22, 12:19 AM EST | Flash Flood Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 3 hr |
| Mar 22, 12:19 AM EST | Flash Flood Warning | PHI | Berks, Chester | 3 hr |
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.