Alert archive / Pennsylvania / Areal Flood Advisories in 2021
Areal Flood Advisory 69, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this areal flood advisory at Jul 12, 2021, 4:16 PM EDT for Bucks County, Montgomery County, Philadelphia County, Pennsylvania. It was in force for 114 min.
The area
The outline as issued.
The facts
- Issued
- Jul 12, 2021, 4:16 PM EDT (20:16 UTC)
- Expired
- Jul 12, 2021, 6:10 PM EDT
- In force
- 114 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Bucks County, PA, Montgomery County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 60 km from the middle of the area, began a volume at 20:20 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
Brookhaven, NY (KOKX), launched 12:00Z, 8.3 hours before the alert went out and 201 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
- 857 J/kg
- Mixed-layer CIN
- -57 J/kg
- Mixed-layer LCL
- 697 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 85 m²/s²
- 0-3 km storm-relative helicity
- 114 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 2.4
The text
As transmitted.
303
WGUS81 KPHI 122016
FLSPHI
Flood Advisory
National Weather Service Mount Holly NJ
416 PM EDT Mon Jul 12 2021
PAC017-091-101-130000-
/O.NEW.KPHI.FA.Y.0069.210712T2016Z-210713T0000Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Montgomery PA-Philadelphia PA-
416 PM EDT Mon Jul 12 2021
The National Weather Service in Mount Holly has issued a
* Flood Advisory for...
Southeastern Bucks County in southeastern Pennsylvania...
Southeastern Montgomery County in southeastern Pennsylvania...
Northwestern Philadelphia County in southeastern Pennsylvania...
* Until 800 PM EDT.
* At 416 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 3 inches possible.
* Some locations that may experience flooding include...
Philadelphia, Norristown, Lansdale, West Norriton, East Norriton,
Conshohocken, Hatboro, Ambler, Collegeville, and Jenkintown.
This includes the following highways...
Pennsylvania Turnpike between mile markers 330 and 349.
Interstate 76 in Pennsylvania between mile markers 333 and 338.
Interstate 476 in Pennsylvania between mile markers 17 and 19.
Northeast Extension between mile markers 21 and 27.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Be aware of your surroundings and do not drive on flooded roads.
&&
LAT...LON 4002 7523 4017 7548 4034 7494 4030 7487
4025 7484 4022 7477 4014 7502 4005 7510
$$
Iovino1 follow-up statement
193
WGUS81 KPHI 122210
FLSPHI
Flood Advisory
National Weather Service Mount Holly NJ
610 PM EDT Mon Jul 12 2021
PAC017-091-101-122220-
/O.CAN.KPHI.FA.Y.0069.000000T0000Z-210713T0000Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Montgomery PA-Philadelphia PA-
610 PM EDT Mon Jul 12 2021
...FLOOD ADVISORY IS CANCELLED FOR CENTRAL BUCKS, SOUTHEASTERN
MONTGOMERY, AND NORTHWESTERN PHILADELPHIA COUNTIES...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
LAT...LON 4002 7523 4017 7548 4034 7494 4030 7487
4025 7484 4022 7477 4014 7502 4005 7510
$$
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, 2:28 PM EDT | Areal Flood Advisory | PHI | Chester | 3 hr |
| Jul 12, 3:08 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Philadelphia | 67 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.