Alert archive / Pennsylvania / Flash Flood Warnings in 2018
Flash Flood Warning 73, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 13, 2018, 8:43 AM EDT for 6 counties in Pennsylvania. It was in force for 4 hr. 7 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 13, 2018, 8:43 AM EDT (12:43 UTC)
- Expired
- Aug 13, 2018, 12:45 PM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Bucks County, PA, Delaware County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 87 km from the middle of the area, began a volume at 12:44 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 13, 8:45 AM EDT | FLASH FLOOD | Upper Darby, PA | *** 1 INJ *** NUMEROUS WATER RESCUES IN UPPER DARBY. A POLICE OFFICER SUFFERED MINOR INJURIES FROM BEING SWEPT AWAY BY FLOODWATERS. |
| Aug 13, 9:00 AM EDT | FLOOD | Roxborough, PA | A HOME BASEMENT FLOODED WITH ABOUT 1 FOOT OF WATER. TIME ESTIMATED. |
| Aug 13, 9:30 AM EDT | FLASH FLOOD | Kensington, PA | MULTIPLE HOMES FLOODED IN KENSINGTON. |
| Aug 13, 9:43 AM EDT | FLASH FLOOD | East Norriton, PA | WATER RESCUE REPORTED AT NORTH WALES ROAD AND MARCIA LANE. |
| Aug 13, 9:43 AM EDT | FLASH FLOOD | Executive Estates Park, PA | WATER RESCUE AT GULPH ROAD AND ARDEN ROAD. |
| Aug 13, 11:22 AM EDT | FLASH FLOOD | 1 Nnw Ancient Oaks, PA | LITTLE LEHIGH CREEK IS OUT OF ITS BANKS MAKING SPRING CREEEK ROAD IMPASSABLE. A BRIDGE NEAR THE HEADWATERS IS ALSO IMPASSABLE AND SUBMERGED IN FLOOD WATERS. 4.3 INCHES OF RAIN HAS FALLEN IN THE LAST 3 HOURS. |
| Aug 13, 11:22 AM EDT | HEAVY RAIN 4.3 | 1 Nnw Ancient Oaks, PA | RAINFALL IN THE LAST 3 HOURS. |
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 12:00Z, 0.7 hours before the alert went out and 211 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
- 307 J/kg
- Mixed-layer CIN
- -7 J/kg
- Mixed-layer LCL
- 450 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 68 m²/s²
- 0-3 km storm-relative helicity
- 107 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
562
WGUS51 KPHI 131243
FFWPHI
PAC017-045-077-091-095-101-131645-
/O.NEW.KPHI.FF.W.0073.180813T1243Z-180813T1645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
843 AM EDT MON AUG 13 2018
The National Weather Service in Mount Holly NJ has issued a
* Flash Flood Warning for...
Montgomery County in southeastern Pennsylvania...
Lehigh County in eastern Pennsylvania...
Bucks County in southeastern Pennsylvania...
Philadelphia County in southeastern Pennsylvania...
Northeastern Delaware County in southeastern Pennsylvania...
Southwestern Northampton County in eastern Pennsylvania...
* Until 1245 PM EDT.
* At 840 AM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Over two inches of rain have
already fallen just west of Philadelphia. These thunderstorms will
continue to drift northward toward area that were previously hard
hit with heavy rain and flash flooding this past Saturday. Flash
flooding is expected to begin shortly in the areas of heaviest
rain.
* Some locations that could experience flooding include...
Philadelphia, Allentown, Camden, Easton, Bethlehem, Bensalem,
Norristown, Lansdale, West Norriton, East Norriton, Yeadon, Emmaus,
Northampton, Quakertown, Perkasie, Doylestown, Wilson,
Conshohocken, Palmyra and Hatboro.
Additional rainfall amounts of 2 to 3 are possible in the warned
area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.
Stay away or be swept away. River banks and culverts can become
unstable and unsafe.
&&
LAT...LON 4078 7567 4079 7561 4067 7523 4062 7519
4057 7519 4057 7515 4042 7506 4030 7491
4010 7489 4007 7492 3996 7513 3988 7515
3987 7521 3985 7527 4045 7553 4068 7589
$$
Klein2 follow-up statements
219
WGUS71 KPHI 131353
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
953 AM EDT MON AUG 13 2018
PAC017-045-077-091-095-101-131645-
/O.CON.KPHI.FF.W.0073.000000T0000Z-180813T1645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery PA-Lehigh PA-Bucks PA-Philadelphia PA-Delaware PA-
Northampton PA-
953 AM EDT MON AUG 13 2018
...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1245 PM EDT FOR
MONTGOMERY...LEHIGH...BUCKS...PHILADELPHIA...NORTHEASTERN DELAWARE
AND SOUTHWESTERN NORTHAMPTON COUNTIES...
At 947 AM EDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain over the warned area. Three to
four inches of rain have already fallen in northeastern Delaware and
southwestern Montgomery Counties in Pennsylvania. Numerous road
closures due to flooding has been reported in Radnor and Upper
Merion. The band of heavy showers and thunderstorms is drifting
northward into southwestern portions of Philadelphia, extending
northward along I-476 into the Lehigh Valley. Flash flooding is
expected to begin shortly in these same areas that were hit hard
with flash flooding just this past Saturday.
Some locations that could experience flooding include...
Philadelphia, Allentown, Camden, Easton, Bethlehem, Bensalem,
Norristown, Lansdale, West Norriton, East Norriton, Yeadon, Emmaus,
Northampton, Quakertown, Perkasie, Doylestown, Wilson, Conshohocken,
Palmyra and Hatboro.
Additional rainfall amounts of 2 to 3 inches are possible in the
warned area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.
Stay away or be swept away. River banks and culverts can become
unstable and unsafe.
&&
LAT...LON 4078 7567 4079 7561 4067 7523 4062 7519
4057 7519 4057 7515 4042 7506 4030 7491
4010 7489 4007 7492 3996 7513 3988 7515
3987 7521 3985 7527 4045 7553 4068 7589
$$
JRK222
WGUS71 KPHI 131640
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
1240 PM EDT MON AUG 13 2018
PAC017-045-077-091-095-101-131648-
/O.EXP.KPHI.FF.W.0073.000000T0000Z-180813T1645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery PA-Lehigh PA-Bucks PA-Philadelphia PA-Delaware PA-
Northampton PA-
1240 PM EDT MON AUG 13 2018
...THE FLASH FLOOD WARNING FOR MONTGOMERY...LEHIGH...BUCKS...
PHILADELPHIA...NORTHEASTERN DELAWARE AND SOUTHWESTERN NORTHAMPTON
COUNTIES WILL EXPIRE AT 1245 PM EDT...
The heavy rain has ended. Life threatening flash flooding is no
longer expected. However, areal flooding will continue this
afternoon. This is now covered by a Flood Warning.
Please continue to heed any remaining road closures.
LAT...LON 4078 7567 4079 7561 4067 7523 4062 7519
4057 7519 4057 7515 4042 7506 4030 7491
4010 7489 4007 7492 3996 7513 3988 7515
3987 7521 3985 7527 4045 7553 4068 7589
$$
JRKThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 12, 10:08 PM EDT | Flash Flood Watch | PHI | Berks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more | 24 hr |
| Aug 13, 4:42 AM EDT | Areal Flood Advisory | PHI | Berks | 4 hr |
| Aug 13, 5:12 AM EDT | Areal Flood Advisory | PHI | Chester | 103 min |
| Aug 13, 6:24 AM EDT | Areal Flood Advisory | PHI | Berks, Chester, Delaware, Montgomery | 4 hr |
| Aug 13, 6:50 AM EDT | Flash Flood Warning | PHI | Berks, Chester, Delaware, Montgomery | 6 hr |
| Aug 13, 8:03 AM EDT | Areal Flood Advisory | PHI | Delaware, Montgomery, Philadelphia | 4 hr |
| Aug 13, 9:21 AM EDT | River Flood Warning | PHI | Chester | 10 hr |
| Aug 13, 10:40 AM EDT | Areal Flood Advisory | PHI | Carbon, Monroe, Northampton | 42 min |
| Aug 13, 11:05 AM EDT | River Flood Warning | PHI | Chester, Delaware | 30 hr |
| Aug 13, 11:21 AM EDT | Areal Flood Warning | PHI | Carbon, Monroe, Northampton | 4 hr |
| Aug 13, 12:14 PM EDT | River Flood Warning | PHI | Berks, Montgomery | 23 hr |
| Aug 13, 12:14 PM EDT | River Flood Warning | PHI | Montgomery | 28 hr |
| Aug 13, 12:14 PM EDT | River Flood Warning | PHI | Chester, Montgomery, Philadelphia | 52 hr |
| Aug 13, 12:37 PM EDT | Areal Flood Warning | PHI | Berks, Bucks, Chester, Delaware, Lehigh, Montgomery and 1 more | 18 hr |
| Aug 13, 3:07 PM EDT | River Flood Warning | PHI | Montgomery | 6 hr |
| Aug 13, 4:57 PM EDT | Areal Flood Advisory | PHI | Carbon, Monroe, Northampton | 3 hr |
| Aug 13, 5:09 PM EDT | River Flood Warning | PHI | Montgomery, Philadelphia | 31 hr |
| Aug 13, 7:27 PM EDT | Areal Flood Warning | PHI | Carbon, Northampton | 7 hr |
| Aug 13, 7:42 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 48 min |
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.