Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 24, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 24, 1999, 3:11 PM EDT for Chester County, Pennsylvania; New Castle County, Delaware. It was in force for 29 min. 4 reports came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- May 24, 1999, 3:11 PM EDT (19:11 UTC)
- Expired
- May 24, 1999, 3:40 PM EDT
- In force
- 29 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Whole counties
Counties New Castle County, DE, Chester County, PA
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| May 24, 3:15 PM EDT | Hail 1.75 | Newark, DE | |
| May 24, 3:15 PM EDT | Thunderstorm Wind 52 | Newark, DE | |
| May 24, 3:15 PM EDT | Thunderstorm Wind 50 | Oxford, PA | |
| May 24, 3:27 PM EDT | Thunderstorm Wind 53 | (Ilg)Wilmington Arpt, DE |
NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| May 24, 1:00 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 7.2 hours before the alert went out and 49 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
- 61 J/kg
- Mixed-layer CIN
- -100 J/kg
- Mixed-layer LCL
- 1309 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km storm-relative helicity
- 105 m²/s²
- 0-3 km storm-relative helicity
- 173 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
999 WUUS1 KPHL 241912 RRA SVRPHL DEC003-PAC029-241940- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 311 PM EDT MON MAY 24 1999 THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTHEASTERN CHESTER COUNTY IN PENNSYLVANIA. NORTHERN NEW CASTLE COUNTY IN DELAWARE. * UNTIL 340 PM EDT. * AT 306 PM EDT... NATIONAL WEATHER SERVICE DOPPLER RADAR AND SPOTTER REPORTS INDICATED A SEVERE THUNDERSTORM IN NORTHEAST CECIL COUNTY IN MD... MOVING NORTHEAST AT 40 MPH. * THE SEVERE THUNDERSTORM IS EXPECTED TO BE NEAR... NEWARK AT 315 PM EDT. AVONDALE AT 315 PM EDT. HOCKESSIN AT 320 PM EDT. KENNETT SQUARE AT 320 PM EDT. WILMINGTON AT 330 PM EDT. THIS STORM PRODUCED HALF-DOLLAR SIZED HAIL NEAR PERRYVILLE IN CECIL COUNTY MARYLAND AT 255 PM EDT. THIS IS A DANGEROUS STORM. MOVE INSIDE A STRONG BUILDING AND DO NOT STAND NEAR WINDOWS. FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS. DO NOT DRIVE YOUR CAR WHERE WATER COVERS THE ROADWAY. THE WATER MAY BE DEEPER THAN YOU THINK. IF CAUGHT IN RISING FLOOD WATERS... ABANDON YOUR CAR QUICKLY AND 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 JRP/AMC &
What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
In the hours before
Local storm report, May 24, 11:55 AM EDT, 3 hours 16 minutes before
STORM REPORT
NATIONAL WEATHER SERVICE PHILADELPHIA, PA
1155 AM EDT MON MAY 24 1999
TIME(EDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0930 AM HARRISOVILLE NJ AT LEAST THREE TREES
05/24/99 GLOUCESTER DOWN
0935 AM VERGA NJ .75 INCH HAIL
05/24/99 GLOUCESTER
0945 AM BLACKWOOD NJ .88 INCH HAIL
05/24/99 CAMDEN
0955 AM MOORESTOWN NJ .75 INCH HAIL
05/24/99 BURLINGTON
1015 AM BRISTOL PA .75 INCH HAIL
05/24/99 BUCKSLocal storm report, May 24, 11:55 AM EDT, 3 hours 16 minutes before
STORM REPORT
NATIONAL WEATHER SERVICE PHILADELPHIA, PA
1155 AM EDT MON MAY 24 1999
TIME(EDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0930 AM HARRISOVILLE NJ AT LEAST THREE TREES
05/24/99 GLOUCESTER DOWN
0935 AM VERGA NJ .75 INCH HAIL
05/24/99 GLOUCESTER
0945 AM BLACKWOOD NJ .88 INCH HAIL
05/24/99 CAMDEN
0955 AM MOORESTOWN NJ .75 INCH HAIL
05/24/99 BURLINGTON
1015 AM BRISTOL PA .75 INCH HAIL
05/24/99 BUCKSSpecial weather statement, May 24, 1:00 PM EDT, 2 hours 11 minutes before
PAZ054-055-060>062-067>071-NJZ001-007>010-012>026-DEZALL-MDZ008-012- 015-019-020-ANZ450>455-ANZ430-431-242300- SPECIAL WEATHER STATEMENT - SEVERE THUNDERSTORM WATCH NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 100 PM EDT MON MAY 24 1999 THE STORM PREDICTION CENTER IN NORMAN OKLAHOMA HAS ISSUED SEVERE THUNDERSTORM WATCH 322 FOR NEW JERSEY...EASTERN PENNSYLVANIA... DELAWARE...NORTHEAST MARYLAND AND THE ADJACENT COASTAL WATERS OF NEW JERSEY AND DELAWARE. SEVERE THUNDERSTORM WATCH 322 IS IN EFFECT UNTIL 700 PM AND INCLUDES THE FOLLOWING COUNTIES... IN PENNSYLVANIA... CARBON...MONROE...BERKS...LEHIGH...NORTHAMPTON...CHESTER... MONTGOMERY...BUCKS...DELAWARE AND PHILADELPHIA. IN NEW JERSEY... SUSSEX...WARREN...MORRIS...HUNTERDON...SOMERSET...MIDDLESEX... MERCER...MONMOUTH...OCEAN...BURLINGTON...CAMDEN...GLOUCESTER... ATLANTIC...SALEM...CUMBERLAND AND CAPE MAY AND THE ADJACENT COASTAL WATERS OF THE ATLANTIC AND FOR DELAWARE BAY. IN DELAWARE... NEW CASTLE...KENT...SUSSEX AND THE ADJACENT COASTAL WATERS OF THE ATLANTIC AND FOR DELAWARE BAY. IN MARYLAND... CECIL...KENT...QUEEN ANNE/S...TALBOT...AND CAROLINE. THE THREAT FOR SEVERE THUNDERSTORMS WILL CONTINUE THIS AFTERNOON AHEAD OF A STRONG COLD FRONT THAT WILL MOVE ACROSS THE AREA THIS EVENING. FOR UPDATED INFORMATION...STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL RADIO OR TV STATIONS OR YOUR CABLE TV PROVIDER. ADDITIONAL WEATHER INFORMATION FROM THE NATIONAL WEATHER SERVICE IS AVAILABLE OVER THE INTERNET. OUR HOME PAGE IS WWW.NWS.NOAA.GOV/ER/PHI MPD
Special weather statement, May 24, 1:00 PM EDT, 2 hours 11 minutes before
PAZ054-055-060>062-067>071-NJZ001-007>010-012>026-DEZALL-MDZ008-012- 015-019-020-ANZ450>455-ANZ430-431-242300- SPECIAL WEATHER STATEMENT - SEVERE THUNDERSTORM WATCH NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 100 PM EDT MON MAY 24 1999 THE STORM PREDICTION CENTER IN NORMAN OKLAHOMA HAS ISSUED SEVERE THUNDERSTORM WATCH 322 FOR NEW JERSEY...EASTERN PENNSYLVANIA... DELAWARE...NORTHEAST MARYLAND AND THE ADJACENT COASTAL WATERS OF NEW JERSEY AND DELAWARE. SEVERE THUNDERSTORM WATCH 322 IS IN EFFECT UNTIL 700 PM AND INCLUDES THE FOLLOWING COUNTIES... IN PENNSYLVANIA... CARBON...MONROE...BERKS...LEHIGH...NORTHAMPTON...CHESTER... MONTGOMERY...BUCKS...DELAWARE AND PHILADELPHIA. IN NEW JERSEY... SUSSEX...WARREN...MORRIS...HUNTERDON...SOMERSET...MIDDLESEX... MERCER...MONMOUTH...OCEAN...BURLINGTON...CAMDEN...GLOUCESTER... ATLANTIC...SALEM...CUMBERLAND AND CAPE MAY AND THE ADJACENT COASTAL WATERS OF THE ATLANTIC AND FOR DELAWARE BAY. IN DELAWARE... NEW CASTLE...KENT...SUSSEX AND THE ADJACENT COASTAL WATERS OF THE ATLANTIC AND FOR DELAWARE BAY. IN MARYLAND... CECIL...KENT...QUEEN ANNE/S...TALBOT...AND CAROLINE. THE THREAT FOR SEVERE THUNDERSTORMS WILL CONTINUE THIS AFTERNOON AHEAD OF A STRONG COLD FRONT THAT WILL MOVE ACROSS THE AREA THIS EVENING. FOR UPDATED INFORMATION...STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL RADIO OR TV STATIONS OR YOUR CABLE TV PROVIDER. ADDITIONAL WEATHER INFORMATION FROM THE NATIONAL WEATHER SERVICE IS AVAILABLE OVER THE INTERNET. OUR HOME PAGE IS WWW.NWS.NOAA.GOV/ER/PHI MPD
Local storm report, May 24, 1:16 PM EDT, 1 hour 55 minutes before
STORM REPORT
NATIONAL WEATHER SERVICE PHILADELPHIA, PA
116 PM EDT MON MAY 24 1999
TIME(EDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
1045 AM BRICKTOWN NJ .75 INCH HAIL
05/24/99 OCEAN
0925 AM WOODSTOWN NJ .75 INCH HAIL
05/24/99 SALEM
0900 AM UNKNOWN MD SEVERAL TREES DOWN
05/24/99 CECILLocal storm report, May 24, 1:16 PM EDT, 1 hour 55 minutes before
STORM REPORT
NATIONAL WEATHER SERVICE PHILADELPHIA, PA
116 PM EDT MON MAY 24 1999
TIME(EDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
1045 AM BRICKTOWN NJ .75 INCH HAIL
05/24/99 OCEAN
0925 AM WOODSTOWN NJ .75 INCH HAIL
05/24/99 SALEM
0900 AM UNKNOWN MD SEVERAL TREES DOWN
05/24/99 CECILThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 24, 10:08 AM EDT | Severe Thunderstorm Warning | PHI | Bucks | 32 min |
| May 24, 12:25 PM EDT | Flash Flood Warning | PHI | Bucks, Philadelphia | 3 hr |
| May 24, 3:26 PM EDT | Severe Thunderstorm Warning | PHI | Delaware | 34 min |
| May 24, 3:40 PM EDT | Severe Thunderstorm Warning | PHI | Philadelphia | 30 min |
| May 24, 4:26 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 34 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 1999Severe Thunderstorm Warnings in Delaware, 1999Every severe thunderstorm 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.