Alert archive / Pennsylvania / Flash Flood Warnings in 2021
Flash Flood Warning 57, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 22, 2021, 10:53 PM EDT for 5 counties in Pennsylvania. It was in force for 4 hr. 1 report 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 22, 2021, 10:53 PM EDT (02:53 UTC)
- Expired
- Aug 23, 2021, 2:41 AM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Carbon County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA
The radar
The Philadelphia radar (KDIX), 130 km from the middle of the area, began a volume at 02:53 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 23, 1:00 AM EDT | FLASH FLOOD | Kresgeville, PA | THE GAUGE ON POHOPOCO CREEK AT KRESGEVILLE (KRVP1) REACHED FLOOD STAGE. |
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 223 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
- 59 J/kg
- Mixed-layer CIN
- -168 J/kg
- Mixed-layer LCL
- 610 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- -22 m²/s²
- 0-3 km storm-relative helicity
- -66 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted.
081
WGUS51 KPHI 230253
FFWPHI
PAC025-077-089-091-095-230900-
/O.NEW.KPHI.FF.W.0057.210823T0253Z-210823T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1053 PM EDT Sun Aug 22 2021
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Lehigh County in eastern Pennsylvania...
Northampton County in eastern Pennsylvania...
Carbon County in northeastern Pennsylvania...
Southwestern Monroe County in northeastern Pennsylvania...
Northern Montgomery County in southeastern Pennsylvania...
* Until 500 AM EDT Monday.
* At 1053 PM EDT, Doppler radar indicated heavy rain across the
warned area. Between 1 and 2 inches of rain have already fallen in
parts of the area. Additional rainfall amounts of 1 to 2 inches
are possible. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by heavy rain.
SOURCE...Radar.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets, and underpasses as well as other
drainage and low lying areas.
* Some locations that will experience flash flooding include...
Allentown, Easton, Lehighton, Bethlehem, Forks, Emmaus,
Northampton, Wilson, Hellertown, Nazareth, Palmerton, and Bangor.
This includes the following highways...
Interstate 78 in Pennsylvania between mile markers 45 and 76.
Interstate 80 in Pennsylvania between mile markers 277 and 289.
Northeast Extension between mile markers 46 and 98.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Motorists should not attempt to drive around barricades or drive
cars through flooded areas.
&&
LAT...LON 4074 7576 4091 7600 4101 7573 4109 7577
4112 7563 4116 7560 4081 7534 4090 7508
4087 7505 4085 7510 4079 7511 4075 7520
4061 7520 4049 7541 4042 7548 4040 7546
4039 7548 4068 7589 4071 7581 4073 7576
FLASH FLOOD...RADAR INDICATED
$$
Iovino1 follow-up statement
369
WGUS71 KPHI 230641
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
241 AM EDT Mon Aug 23 2021
PAC025-077-089-091-095-230651-
/O.CAN.KPHI.FF.W.0057.000000T0000Z-210823T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Carbon PA-Lehigh PA-Monroe PA-Montgomery PA-Northampton PA-
241 AM EDT Mon Aug 23 2021
...FLASH FLOOD WARNING IS CANCELLED FOR LEHIGH, NORTHAMPTON, CARBON,
SOUTHWESTERN MONROE, AND NORTHERN MONTGOMERY COUNTIES...
The heavy rain has ended. A Flood Warning remains in effect for
Monroe County and eastern Carbon County. Please continue to heed
remaining road closures.
LAT...LON 4074 7576 4091 7600 4101 7573 4109 7577
4112 7563 4116 7560 4081 7534 4090 7508
4087 7505 4085 7510 4079 7511 4075 7520
4061 7520 4049 7541 4042 7548 4040 7546
4039 7548 4068 7589 4071 7581 4073 7576
$$
IovinoThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 22, 8:11 PM EDT | Areal Flood Advisory | PHI | Carbon, Monroe, Northampton | 6 hr |
| Aug 22, 8:47 PM EDT | Flash Flood Warning | PHI | Monroe, Northampton | 6 hr |
| Aug 22, 10:34 PM EDT | Areal Flood Advisory | PHI | Carbon, Lehigh, Northampton | 3 hr |
| Aug 22, 11:42 PM EDT | Areal Flood Advisory | PHI | Berks | 3 hr |
| Aug 23, 12:32 AM EDT | River Flood Warning | PHI | Monroe | 10 hr |
| Aug 23, 12:55 AM EDT | River Flood Warning | PHI | Monroe | 10 hr |
| Aug 23, 2:36 AM EDT | Areal Flood Warning | PHI | Carbon, Monroe | 21 hr |
| Aug 23, 3:50 AM EDT | River Flood Warning | PHI | Carbon | 3 hr |
| Aug 23, 3:50 AM EDT | River Flood Warning | PHI | Lehigh, Northampton | 11 hr |
| Aug 23, 8:28 AM EDT | Areal Flood Warning | PHI | Lehigh | 7 hr |
| Aug 23, 4:41 PM EDT | Special Weather Statement | PHI | Montgomery | 34 min |
Nearby
Flash Flood Warnings in Pennsylvania, 2021Every flash flood warning in 2021
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.