Alert archive / Pennsylvania / Flash Flood Warnings in 2018
Flash Flood Warning 35, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 17, 2018, 2:27 PM EDT for Berks County, Chester County, Montgomery County, Pennsylvania. It was in force for 4 hr. 2 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 17, 2018, 2:27 PM EDT (18:27 UTC)
- Expired
- Jul 17, 2018, 6:30 PM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Berks County, PA, Chester County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 116 km from the middle of the area, began a volume at 18:26 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 17, 2:30 PM EDT | FLASH FLOOD | 1 N Pottstown, PA | MULTIPLE WATER RESCUES REPORTED WITH SEVERAL INTERSECTIONS CLOSED IN POTTSTOWN. |
| Jul 17, 2:41 PM EDT | FLOOD | 1 Sse Pottstown, PA | FLOODED UNDERPASS UNDER SOUTH KEIM ROAD AND RAILROAD TRACKS REPORTED. |
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, 6.5 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
- 644 J/kg
- Mixed-layer CIN
- -93 J/kg
- Mixed-layer LCL
- 959 m above ground
- 0-6 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- 39 m²/s²
- 0-3 km storm-relative helicity
- 74 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
698
WGUS51 KPHI 171827
FFWPHI
PAC011-029-091-172230-
/O.NEW.KPHI.FF.W.0035.180717T1827Z-180717T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
227 PM EDT TUE JUL 17 2018
The National Weather Service in Mount Holly NJ has issued a
* Flash Flood Warning for...
Southeastern Berks County in eastern Pennsylvania...
Northwestern Montgomery County in southeastern Pennsylvania...
North central Chester County in southeastern Pennsylvania...
* Until 630 PM EDT.
* At 224 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Up to one inch of rain has
already fallen. Specifically, Pottstown Airport reported almost
one inch of rain in about 20 minutes. Flash flooding is expected
to begin shortly in the areas of heaviest rain.
* Some locations that could experience flooding include...
Pottstown, Birdsboro, East Greenville, Elverson, Bally,
Bechtelsville, Green Lane, New Morgan, Gilbertsville, Cedarville,
Stowe, Boyertown, Pennsburg, Red Hill, Pottsgrove, South Pottstown,
Amity Gardens, Sanatoga, Kenilworth and Halfway House.
Additional rainfall amounts of one to two inches are possible in the
warned area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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 4044 7553 4035 7538 4010 7581 4014 7586
4013 7587 4014 7587 4019 7593
$$
Kruzdlo2 follow-up statements
033
WGUS71 KPHI 171859
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
259 PM EDT TUE JUL 17 2018
PAC011-029-091-172230-
/O.CON.KPHI.FF.W.0035.000000T0000Z-180717T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Montgomery PA-Chester PA-
259 PM EDT TUE JUL 17 2018
...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM EDT FOR
SOUTHEASTERN BERKS...NORTHWESTERN MONTGOMERY AND NORTH CENTRAL
CHESTER COUNTIES...
At 256 PM EDT, the public reported multiple water rescues in the
Pottstown area. Doppler radar rainfall estimates are now up to three
inches.
Some locations that could experience flooding include... Pottstown,
Birdsboro, East Greenville, Elverson, Bally, Bechtelsville, Green
Lane, New Morgan, Gilbertsville, Cedarville, Stowe, Boyertown,
Pennsburg, Red Hill, Pottsgrove, South Pottstown, Amity Gardens,
Sanatoga, Kenilworth and Halfway House.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 4044 7553 4035 7538 4010 7581 4014 7586
4013 7587 4014 7587 4019 7593
$$
Kruzdlo781
WGUS71 KPHI 172223
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
623 PM EDT TUE JUL 17 2018
PAC011-029-091-172233-
/O.EXP.KPHI.FF.W.0035.000000T0000Z-180717T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Montgomery PA-Chester PA-
623 PM EDT TUE JUL 17 2018
...THE FLASH FLOOD WARNING FOR SOUTHEASTERN BERKS...NORTHWESTERN
MONTGOMERY AND NORTH CENTRAL CHESTER COUNTIES WILL EXPIRE AT 630 PM
EDT...
The heavy rain has ended. Flood waters have receded. Flooding is no
longer expected to pose a threat. Please continue to heed any
remaining road closures.
LAT...LON 4044 7553 4035 7538 4010 7581 4014 7586
4013 7587 4014 7587 4019 7593
$$
MPSThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 17, 3:36 AM EDT | Flash Flood Watch | PHI | Bucks, Delaware, Montgomery, Philadelphia | 15 hr |
| Jul 17, 1:49 PM EDT | Special Weather Statement | PHI | Chester, Montgomery | 41 min |
| Jul 17, 2:05 PM EDT | Areal Flood Advisory | PHI | Berks, Bucks, Chester, Lehigh, Montgomery, Northampton | 3 hr |
| Jul 17, 2:21 PM EDT | Special Weather Statement | PHI | Chester | 39 min |
| Jul 17, 2:50 PM EDT | Areal Flood Advisory | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 3 hr |
| Jul 17, 3:09 PM EDT | Special Weather Statement | PHI | Philadelphia | 36 min |
| Jul 17, 3:35 PM EDT | Special Weather Statement | PHI | Delaware, Montgomery | 25 min |
| Jul 17, 4:03 PM EDT | Areal Flood Advisory | PHI | Bucks | 2 hr |
Nearby
Flash Flood Warnings in Pennsylvania, 2018Every flash flood warning in 2018
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.