Alert archive / Pennsylvania / Areal Flood Advisories in 2021
Areal Flood Advisory 68, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this areal flood advisory at Jul 12, 2021, 2:28 PM EDT for Chester County, Pennsylvania. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 12, 2021, 2:28 PM EDT (18:28 UTC)
- Expired
- Jul 12, 2021, 5:29 PM EDT
- In force
- 3 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
County Chester County, PA
The radar
The Philadelphia radar (KDIX), 119 km from the middle of the area, began a volume at 18:31 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, 6.5 hours before the alert went out and 171 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
- 974 J/kg
- Mixed-layer CIN
- -83 J/kg
- Mixed-layer LCL
- 724 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 10 m²/s²
- 0-3 km storm-relative helicity
- 53 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.8
The text
As transmitted.
826
WGUS81 KPHI 121828
FLSPHI
Flood Advisory
National Weather Service Mount Holly NJ
228 PM EDT Mon Jul 12 2021
PAC029-122100-
/O.NEW.KPHI.FA.Y.0068.210712T1828Z-210712T2100Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-
228 PM EDT Mon Jul 12 2021
The National Weather Service in Mount Holly has issued a
* Flood Advisory for...
Southern Chester County in southeastern Pennsylvania...
* Until 500 PM EDT.
* At 228 PM EDT, Doppler radar indicated heavy rain due to
thunderstorms. Minor flooding is ongoing or expected to begin
shortly in the advisory area. Between 0.5 and 1 inch of rain has
already fallen in spots with an additional 1 to 2 inches possible.
* Some locations that may experience flooding include...
West Chester, Coatesville, Westtown, Downingtown, Kennett Square,
Oxford, Parkesburg, West Grove, Ladenberg, Cochranville,
Kemblesville, and Marshallton.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Be aware of your surroundings and do not drive on flooded roads.
&&
LAT...LON 4002 7595 4001 7542 3999 7545 3999 7544
3994 7552 3992 7552 3993 7554 3987 7560
3984 7560 3980 7570 3972 7577 3972 7614
3973 7609 3975 7610 3976 7606 3983 7604
3983 7602 3985 7602 3987 7599 3995 7599
$$
Iovino2 follow-up statements
774
WGUS81 KPHI 122030
FLSPHI
Flood Advisory
National Weather Service Mount Holly NJ
430 PM EDT Mon Jul 12 2021
PAC029-130000-
/O.EXT.KPHI.FA.Y.0068.000000T0000Z-210713T0000Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-
430 PM EDT Mon Jul 12 2021
The National Weather Service in Mount Holly has extended the
* Flood Advisory for...
Southern Chester County in southeastern Pennsylvania...
* Until 800 PM EDT.
* At 430 PM EDT, Doppler radar indicated heavy rain due to
thunderstorms. Minor flooding is ongoing or expected to begin
shortly in the advisory area. Between 0.5 and 1.5 inches of rain
have already fallen in spots with an additional 1 to 3 inches
possible.
* Some locations that may experience flooding include...
West Chester, Coatesville, Westtown, Downingtown, Kennett Square,
Oxford, Parkesburg, West Grove, Ladenberg, Cochranville,
Kemblesville, and Marshallton.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Be aware of your surroundings and do not drive on flooded roads.
&&
LAT...LON 4002 7595 4001 7542 3999 7545 3999 7544
3994 7552 3992 7552 3993 7554 3987 7560
3984 7560 3980 7570 3972 7577 3972 7614
3973 7609 3975 7610 3976 7606 3983 7604
3983 7602 3985 7602 3987 7599 3995 7599
$$
Iovino963
WGUS81 KPHI 122129
FLSPHI
Flood Advisory
National Weather Service Mount Holly NJ
529 PM EDT Mon Jul 12 2021
PAC029-122139-
/O.CAN.KPHI.FA.Y.0068.000000T0000Z-210713T0000Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-
529 PM EDT Mon Jul 12 2021
...FLOOD ADVISORY IS CANCELLED FOR SOUTHERN CHESTER COUNTY...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
LAT...LON 4002 7595 4001 7542 3999 7545 3999 7544
3994 7552 3992 7552 3993 7554 3987 7560
3984 7560 3980 7570 3972 7577 3972 7614
3973 7609 3975 7610 3976 7606 3983 7604
3983 7602 3985 7602 3987 7599 3995 7599
$$
IovinoThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 11, 10:21 PM EDT | Severe Thunderstorm Warning | PHI | Berks | 24 min |
| Jul 11, 10:22 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Carbon, Lehigh, Monroe, Northampton | 38 min |
| Jul 12, 1:59 PM EDT | Areal Flood Advisory | PHI | Bucks, Montgomery, Philadelphia | 3 hr |
| Jul 12, 2:12 PM EDT | Flash Flood Warning | PHI | Bucks, Philadelphia | 7 hr |
| Jul 12, 3:08 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Philadelphia | 67 min |
| Jul 12, 4:16 PM EDT | Areal Flood Advisory | PHI | Bucks, Montgomery, Philadelphia | 114 min |
| Jul 12, 5:08 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 67 min |
| Jul 12, 5:26 PM EDT | Areal Flood Advisory | PHI | Delaware, Montgomery, Philadelphia | 2 hr |
| Jul 12, 5:41 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 34 min |
| Jul 12, 6:01 PM EDT | Flash Flood Warning | PHI | Philadelphia | 102 min |
| Jul 12, 6:18 PM EDT | Flash Flood Warning | PHI | Delaware | 84 min |
| Jul 12, 7:06 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware | 69 min |
Nearby
Areal Flood Advisories in Pennsylvania, 2021Every areal flood advisory 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.