Alert archive / Pennsylvania / Flash Flood Warnings in 2015
Flash Flood Warning 48, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 20, 2015, 10:55 PM EDT for 5 counties in Pennsylvania. It was in force for 4 hr. 5 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
- Aug 20, 2015, 10:55 PM EDT (02:55 UTC)
- Expired
- Aug 21, 2015, 3:00 AM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Berks County, PA, Bucks County, PA, Chester County, PA, Lehigh County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 83 km from the middle of the area, began a volume at 02:58 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 |
|---|---|---|---|
| Aug 20, 11:15 PM EDT | HEAVY RAIN 1.83 | Franconia Twp, PA | FELL IN 30 MINUTES. |
| Aug 20, 11:27 PM EDT | HEAVY RAIN 1.94 | Graterford, PA | AMOUNT FELL IN ABOUT 30 MINUTES. |
| Aug 20, 11:27 PM EDT | HEAVY RAIN 1.94 | Graterford, PA | AMOUNT FELL IN ABOUT 30 MINUTES. |
| Aug 21, 12:28 AM EDT | HEAVY RAIN 2.52 | North Wales, PA | 2.3 INCHES FELL IN 50 MINUTES. |
| Aug 21, 12:33 AM EDT | HEAVY RAIN 1.92 | 1 W Ambler, PA |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Brookhaven, NY (KOKX), launched 00:00Z, 2.9 hours before the alert went out and 204 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
- 178 J/kg
- Mixed-layer CIN
- -11 J/kg
- Mixed-layer LCL
- 657 m above ground
- 0-6 km bulk shear
- 9 kt
- 0-1 km storm-relative helicity
- 72 m²/s²
- 0-3 km storm-relative helicity
- 121 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
051
WGUS51 KPHI 210255
FFWPHI
PAC011-017-029-077-091-210700-
/O.NEW.KPHI.FF.W.0048.150821T0255Z-150821T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1055 PM EDT THU AUG 20 2015
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* FLASH FLOOD WARNING FOR...
NORTHEASTERN CHESTER COUNTY IN SOUTHEASTERN PENNSYLVANIA...
SOUTHEASTERN LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
EASTERN BERKS COUNTY IN EASTERN PENNSYLVANIA...
WESTERN BUCKS COUNTY IN SOUTHEASTERN PENNSYLVANIA...
MONTGOMERY COUNTY IN SOUTHEASTERN PENNSYLVANIA...
* UNTIL 300 AM EDT
* AT 1055 PM EDT...DOPPLER RADAR INDICATED A THUNDERSTORM PRODUCING
HEAVY RAIN ACROSS THE WARNED AREA. UP TO ONE INCH OF RAIN HAS
ALREADY FALLEN. FLASH FLOODING IS EXPECTED TO BEGIN SHORTLY.
* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
NORRISTOWN...PHOENIXVILLE...LANSDALE...WEST NORRITON...EAST
NORRITON...QUAKERTOWN...PERKASIE...DOYLESTOWN...HATBORO...
SOUDERTON...BEDMINSTER...AMBLER...COLLEGEVILLE...ROYERSFORD...
CHALFONT...TINICUM...TRAPPE...HATFIELD...EAST GREENVILLE AND
DUBLIN.
ADDITIONAL RAINFALL AMOUNTS OF 1 TO 1.5 INCHES ARE POSSIBLE IN THE
WARNED AREA OVER THE NEXT HOUR.
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 4050 7553 4053 7507 4049 7506 4046 7507
4041 7506 4040 7501 4030 7499 4012 7507
4012 7561
$$
HEAVENER3 follow-up statements
655
WGUS71 KPHI 210404
FFSPHI
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1204 AM EDT FRI AUG 21 2015
PAC011-077-210413-
/O.CAN.KPHI.FF.W.0048.000000T0000Z-150821T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LEHIGH PA-BERKS PA-
1204 AM EDT FRI AUG 21 2015
...THE FLASH FLOOD WARNING FOR SOUTHEASTERN LEHIGH AND EASTERN BERKS
COUNTIES IS CANCELLED...
THE HEAVY RAIN HAS ENDED...AND FLOODING IS NO LONGER EXPECTED TO POSE
A THREAT. PLEASE CONTINUE TO HEED ALL ROAD CLOSURES.
LAT...LON 4038 7555 4053 7507 4049 7506 4046 7507
4041 7506 4040 7501 4030 7499 4012 7507
4012 7561
$$
PAC017-029-091-210700-
/O.CON.KPHI.FF.W.0048.000000T0000Z-150821T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHESTER PA-BUCKS PA-MONTGOMERY PA-
1204 AM EDT FRI AUG 21 2015
...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 300 AM EDT FOR
NORTHEASTERN CHESTER...CENTRAL BUCKS AND MONTGOMERY COUNTIES...
AT 1203 AM EDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING
HEAVY RAIN ACROSS THE WARNED AREA. UP TO TWO INCHES OF RAIN HAVE
ALREADY FALLEN. MORE STORMS WILL AFFECT THE SOUTHEASTERN PORTION OF
THE WARNING, MAINLY THE FORT WASHINGTON AND WILLOW GROVE AREAS.
FLASH FLOODING WILL CONTINUE TO POSE A THREAT.
SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
NORRISTOWN...PHOENIXVILLE...LANSDALE...WEST NORRITON...EAST
NORRITON...QUAKERTOWN...PERKASIE...DOYLESTOWN...HATBORO...
SOUDERTON...BEDMINSTER...AMBLER...COLLEGEVILLE...ROYERSFORD...
CHALFONT...TINICUM...TRAPPE...HATFIELD...DUBLIN AND ABINGTON.
ADDITIONAL RAINFALL AMOUNTS OF ONE INCH ARE POSSIBLE IN THE WARNED
AREA.
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 4038 7555 4053 7507 4049 7506 4046 7507
4041 7506 4040 7501 4030 7499 4012 7507
4012 7561
$$
HEAVENER316
WGUS71 KPHI 210545
FFSPHI
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
145 AM EDT FRI AUG 21 2015
PAC017-029-091-210700-
/O.CON.KPHI.FF.W.0048.000000T0000Z-150821T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHESTER PA-BUCKS PA-MONTGOMERY PA-
145 AM EDT FRI AUG 21 2015
...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 300 AM EDT FOR
NORTHEASTERN CHESTER...CENTRAL BUCKS AND MONTGOMERY COUNTIES...
AT 141 AM EDT...EMERGENCY MANAGEMENT REPORTED FLASH FLOODING IN
ABINGTON TOWNSHIP IN MONTGOMERY COUNTY.
FLASH FLOODING MAYBE OCCURRING IN OTHER LOCATIONS WITHIN THE WARNED
AREA DUE TO THE EARLIER HEAVY RAINFALL.
SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
NORRISTOWN...PHOENIXVILLE...LANSDALE...WEST NORRITON...EAST
NORRITON...QUAKERTOWN...PERKASIE...DOYLESTOWN...HATBORO...
SOUDERTON...BEDMINSTER...AMBLER...COLLEGEVILLE...ROYERSFORD...
CHALFONT...TINICUM...TRAPPE...HATFIELD...DUBLIN AND ABINGTON.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.
TURN AROUND...DON'T DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD
DEATHS OCCUR IN VEHICLES.
&&
LAT...LON 4038 7555 4053 7507 4049 7506 4046 7507
4041 7506 4040 7501 4030 7499 4012 7507
4012 7561
$$
HEAVENER886
WGUS71 KPHI 210652
FFSPHI
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
252 AM EDT FRI AUG 21 2015
PAC017-029-091-210702-
/O.EXP.KPHI.FF.W.0048.000000T0000Z-150821T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHESTER PA-BUCKS PA-MONTGOMERY PA-
252 AM EDT FRI AUG 21 2015
...THE FLASH FLOOD WARNING FOR NORTHEASTERN CHESTER...CENTRAL BUCKS
AND MONTGOMERY COUNTIES WILL EXPIRE AT 300 AM EDT...
FLOOD WATERS HAVE RECEDED...AND ARE NO LONGER EXPECTED TO POSE A
THREAT TO LIFE OR PROPERTY. PLEASE CONTINUE TO HEED ANY ROAD
CLOSURES.
LAT...LON 4038 7555 4053 7507 4049 7506 4046 7507
4041 7506 4040 7501 4030 7499 4012 7507
4012 7561
$$
HEAVENERThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 9:08 PM EDT | Areal Flood Advisory | PHI | Berks, Carbon, Lehigh, Monroe, Northampton | 4 hr |
| Aug 20, 10:32 PM EDT | Areal Flood Advisory | PHI | Berks, Bucks, Chester, Lehigh, Montgomery, Northampton | 4 hr |
| Aug 20, 11:18 PM EDT | Special Weather Statement | PHI | Bucks, Montgomery | 57 min |
| Aug 20, 11:35 PM EDT | Areal Flood Advisory | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 4 hr |
| Aug 21, 12:46 AM EDT | Flash Flood Warning | PHI | Bucks, Montgomery, Philadelphia | 4 hr |
| Aug 21, 5:38 AM EDT | Areal Flood Warning | PHI | Philadelphia | 112 min |
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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.