Alert archive / Pennsylvania / Flash Flood Warnings in 2015
Flash Flood Warning 51, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 10, 2015, 6:19 PM EDT for Chester County, Montgomery County, Pennsylvania. It was in force for 116 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Sep 10, 2015, 6:19 PM EDT (22:19 UTC)
- Expired
- Sep 10, 2015, 8:15 PM EDT
- In force
- 116 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Chester County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 91 km from the middle of the area, began a volume at 22:21 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
Washington/Dulle, VA (KIAD), launched 12:00Z, 10.3 hours before the alert went out and 209 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
- 58 J/kg
- Mixed-layer CIN
- -85 J/kg
- Mixed-layer LCL
- 843 m above ground
- 0-6 km bulk shear
- 8 kt
- 0-1 km storm-relative helicity
- -4 m²/s²
- 0-3 km storm-relative helicity
- 75 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
255 WGUS51 KPHI 102219 FFWPHI PAC029-091-110015- /O.NEW.KPHI.FF.W.0051.150910T2219Z-150911T0015Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 619 PM EDT THU SEP 10 2015 THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A * FLASH FLOOD WARNING FOR... EAST CENTRAL CHESTER COUNTY IN SOUTHEASTERN PENNSYLVANIA... SOUTH CENTRAL MONTGOMERY COUNTY IN SOUTHEASTERN PENNSYLVANIA... * UNTIL 815 PM EDT * AT 618 PM EDT...DOPPLER RADAR INDICATED HEAVY RAIN SLOWLY MOVING ACROSS THE WARNED AREA. A RAIN GAUGE IN VALLEY FORGE MEASURED 2 INCHES IN THE LAST HOUR. FLASH FLOODING IS EXPECTED TO BEGIN SHORTLY. * SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE... VALLEY FORGE...PAOLI...DEVON-BERWYN AND CHESTERBROOK. PRECAUTIONARY/PREPAREDNESS ACTIONS... MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE. TURN AROUND...DON'T DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD DEATHS OCCUR IN VEHICLES. && LAT...LON 4013 7547 4006 7538 4003 7547 4010 7555 $$ GORSE
1 follow-up statement
550 WGUS71 KPHI 102304 FFSPHI FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 704 PM EDT THU SEP 10 2015 PAC029-091-102312- /O.CAN.KPHI.FF.W.0051.000000T0000Z-150911T0015Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ CHESTER PA-MONTGOMERY PA- 704 PM EDT THU SEP 10 2015 ...THE FLASH FLOOD WARNING FOR EAST CENTRAL CHESTER AND SOUTH CENTRAL MONTGOMERY COUNTIES IS CANCELLED... THE SLOW MOVING HEAVY RAIN HAS DIMINISHED CONSIDERABLY DURING THE PAST 30 MINUTES OR SO, THEREFORE THE FLASH FLOOD WARNING HAS BEEN CANCELLED. LAT...LON 4013 7547 4006 7538 4003 7547 4010 7555 $$ GORSE
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 10, 4:46 AM EDT | Special Weather Statement | PHI | Chester, Delaware, Philadelphia | 119 min |
| Sep 10, 12:02 PM EDT | Areal Flood Advisory | PHI | Philadelphia | 4 hr |
| Sep 10, 12:34 PM EDT | Flash Flood Watch | PHI | Berks, Bucks, Chester, Delaware, Lehigh, Montgomery and 2 more | 6 hr |
| Sep 10, 2:15 PM EDT | Areal Flood Warning | PHI | Philadelphia | 3 hr |
| Sep 10, 3:22 PM EDT | Areal Flood Advisory | PHI | Berks, Lehigh | 3 hr |
| Sep 10, 3:49 PM EDT | Areal Flood Advisory | PHI | Berks, Bucks, Chester, Lehigh, Montgomery | 3 hr |
| Sep 10, 4:14 PM EDT | Areal Flood Advisory | PHI | Carbon, Monroe, Northampton | 3 hr |
Nearby
Flash Flood Warnings in Pennsylvania, 2015Every flash flood warning in 2015
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.