Alert archive / Pennsylvania / Flash Flood Warnings in 2019
Flash Flood Warning 58, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 18, 2019, 3:33 PM EDT for Chester County, Delaware County, Pennsylvania. It was in force for 4 hr. 4 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Jul 18, 2019, 3:33 PM EDT (19:33 UTC)
- Expired
- Jul 18, 2019, 7:05 PM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Chester County, PA, Delaware County, PA
The radar
The Philadelphia radar (KDIX), 98 km from the middle of the area, began a volume at 19:36 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 was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 18, 4:04 PM EDT | FLASH FLOOD | West Chester, PA | MULTIPLE FLOODED ROADWAYS; WATER RESCUES ON MONTGOMERY AVE. AND GAY STREET. |
| Jul 18, 4:44 PM EDT | FLOOD | 1 E East Whiteland Twp, PA | REPORT OF FLOODING ON US-202. |
| Jul 18, 5:25 PM EDT | FLASH FLOOD | 1 S East Goshen Twp., PA | CHESTER CREEK OVERFLOWED ONTO THE ROAD AT THE INTERSECTION OF RESERVOIR AND STRASBOURG ROADS. |
| Jul 18, 5:29 PM EDT | FLOOD | West Chester, PA | FLOODING ON MONTGOMERY AVE. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 7.6 hours before the alert went out and 195 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
- 208 J/kg
- Mixed-layer CIN
- -96 J/kg
- Mixed-layer LCL
- 1102 m above ground
- 0-6 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- 41 m²/s²
- 0-3 km storm-relative helicity
- 66 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
699 WGUS51 KPHI 181933 FFWPHI PAC029-045-182330- /O.NEW.KPHI.FF.W.0058.190718T1933Z-190718T2330Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED Flash Flood Warning National Weather Service Mount Holly NJ 333 PM EDT Thu Jul 18 2019 The National Weather Service in Mount Holly NJ has issued a * Flash Flood Warning for... Central Chester County in southeastern Pennsylvania... Central Delaware County in southeastern Pennsylvania... * Until 730 PM EDT. * At 331 PM EDT, Doppler radar indicated thunderstorms producing heavy rain across the warned area. Up to two inches of rain have already fallen in a short amount of time. Flash flooding is expected to begin shortly in the areas of heaviest rain. * Some locations that could experience flooding include... West Chester, Coatesville, Westtown, Downingtown, Gradyville, Cheyney, Paoli, Chester Springs, Newtown Square, Lionville, Marshallton, Trout Lake, Lionville-Marchwood, Radnor Township, Broomall, West Goshen, Malvern, South Coatesville, Modena and Exton. PRECAUTIONARY/PREPAREDNESS ACTIONS... Turn around...don't drown when encountering flooded roads. Most flood deaths occur in vehicles. A Flash Flood Warning means that flooding is imminent or occurring. If you are in the warned area move to higher ground immediately. Residents living along streams and creeks should take immediate precautions to protect life and property. && LAT...LON 4000 7531 3988 7557 3987 7586 4016 7574 $$ Robertson
2 follow-up statements
508 WGUS71 KPHI 182043 FFSPHI Flash Flood Statement National Weather Service Mount Holly NJ 443 PM EDT Thu Jul 18 2019 PAC029-045-182330- /O.CON.KPHI.FF.W.0058.000000T0000Z-190718T2330Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Chester PA-Delaware PA- 443 PM EDT Thu Jul 18 2019 ...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 730 PM EDT FOR CENTRAL CHESTER AND CENTRAL DELAWARE COUNTIES... At 441 PM EDT, Doppler radar indicated two to three inches of rain from earlier thunderstorms. Flash flooding is occurring with road closures and water rescues, especially in West Chester and West Goshen. Some locations that could experience flooding include... West Chester, Coatesville, Westtown, Downingtown, Gradyville, Cheyney, Paoli, Chester Springs, Newtown Square, Lionville, Marshallton, Trout Lake, Lionville-Marchwood, Radnor Township, Broomall, West Goshen, Malvern, South Coatesville, Modena and Exton. PRECAUTIONARY/PREPAREDNESS ACTIONS... Turn around...don't drown when encountering flooded roads. Most flood deaths occur in vehicles. A Flash Flood Warning means that flooding is imminent or occurring. If you are in the warned area move to higher ground immediately. Residents living along streams and creeks should take immediate precautions to protect life and property. && LAT...LON 4000 7531 3988 7557 3987 7586 4016 7574 $$ Robertson
270 WGUS71 KPHI 182305 FFSPHI Flash Flood Statement National Weather Service Mount Holly NJ 705 PM EDT Thu Jul 18 2019 PAC029-045-182314- /O.CAN.KPHI.FF.W.0058.000000T0000Z-190718T2330Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Chester PA-Delaware PA- 705 PM EDT Thu Jul 18 2019 ...THE FLASH FLOOD WARNING FOR CENTRAL CHESTER AND CENTRAL DELAWARE COUNTIES IS CANCELLED... The heavy rain has ended. Flash flooding is no longer expected to pose a threat. Please continue to heed any remaining road closures as the water may be slow to recede in some areas. LAT...LON 4000 7531 3988 7557 3987 7586 4016 7574 $$ Robertson
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 17, 8:01 PM EDT | Areal Flood Advisory | PHI | Northampton | 88 min |
| Jul 17, 8:15 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 45 min |
| Jul 18, 1:30 PM EDT | Areal Flood Advisory | PHI | Chester, Delaware, Montgomery, Philadelphia | 4 hr |
| Jul 18, 2:13 PM EDT | Areal Flood Advisory | PHI | Bucks, Montgomery, Philadelphia | 4 hr |
| Jul 18, 2:24 PM EDT | Areal Flood Advisory | PHI | Berks, Bucks, Chester, Lehigh, Montgomery | 3 hr |
| Jul 18, 2:55 PM EDT | Flash Flood Warning | PHI | Chester | 4 hr |
| Jul 18, 7:44 PM EDT | Special Weather Statement | PHI | Berks | 46 min |
Nearby
Flash Flood Warnings in Pennsylvania, 2019Every flash flood warning in 2019
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.