Alert archive / Pennsylvania / Flash Flood Warnings in 2004
Flash Flood Warning 90, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 18, 2004, 1:45 PM EDT for 4 counties in Pennsylvania. It was in force for 2 hr. 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 18, 2004, 1:45 PM EDT (17:45 UTC)
- Expired
- Sep 18, 2004, 4:00 PM EDT
- In force
- 2 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Counties, with a storm outline in the text
Counties Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 92 km from the middle of the area, began a volume at 17:47 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, 5.8 hours before the alert went out and 203 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
- 2 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 498 m above ground
- 0-6 km bulk shear
- 4 kt
- 0-1 km storm-relative helicity
- 14 m²/s²
- 0-3 km storm-relative helicity
- 166 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
WGUS51 KPHI 181748
FFWPHI
PAC017-029-045-091-182000-
/X.NEW.KPHI.FF.W.0010.040918T1745Z-040918T2000Z/
/0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
145 PM EDT SAT SEP 18 2004
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS EXTENDED A
* FLASH FLOOD WARNING FOR...
BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA
CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA
NORTHWESTERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA
MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA
* UNTIL 400 PM EDT
* AT 143 PM EDT...FLASH FLOODING WAS REPORTED OVER THE WARNED AREA.
* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SPRING
MOUNT...SOUDERTON...RICHBORO...QUAKERTOWN...PERKASIE...LANSDALE...
IVYLAND...DUBLIN...DOYLESTOWN...COLLEGEVILLE AND CHALFONT.
ALTHOUGH RAINFALL IS RAPIDLY TAPERING OFF...MANY STREAMS IN THE AREA
ARE STILL ABOVE FLOOD STAGE. THEREFORE THE FLASH FLOOD WARNING
CONTINUES IN EFFECT.
EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.
LAT...LON 4026 7490 4008 7521 4010 7523 4002 7531
3986 7558 3983 7569 3975 7577 3978 7606
3987 7599 3997 7599 4055 7521
$$
AMCThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 18, 3:29 AM EDT | Severe Thunderstorm Warning | PHI | Chester | 31 min |
| Sep 18, 6:09 AM EDT | Flash Flood Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 4 hr |
| Sep 18, 7:07 AM EDT | Flash Flood Warning | PHI | Bucks, Montgomery | 4 hr |
| Sep 18, 9:48 AM EDT | Flash Flood Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 4 hr |
| Sep 18, 10:31 AM EDT | Flash Flood Warning | PHI | Chester, Delaware | 3 hr |
| Sep 18, 10:57 AM EDT | Flash Flood Warning | PHI | Bucks, Montgomery | 3 hr |
| Sep 18, 2:00 PM EDT | Flash Flood Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 3 hr |
Nearby
Flash Flood Warnings in Pennsylvania, 2004Every flash flood warning in 2004
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.