Alert archive / Pennsylvania / Areal Flood Advisories in 2021
Areal Flood Advisory 79, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this areal flood advisory at Jul 13, 2021, 1:34 AM EDT for Berks County, Chester County, Montgomery County, Pennsylvania. It was in force for 117 min.
The area
The outline as issued.
The facts
- Issued
- Jul 13, 2021, 1:34 AM EDT (05:34 UTC)
- Expired
- Jul 13, 2021, 3:31 AM EDT
- In force
- 117 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Berks County, PA, Chester County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 149 km from the middle of the area, began a volume at 05:36 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 00:00Z, 5.6 hours before the alert went out and 199 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
- 1475 J/kg
- Mixed-layer CIN
- -40 J/kg
- Mixed-layer LCL
- 1322 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 109 m²/s²
- 0-3 km storm-relative helicity
- 131 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 4.3
The text
As transmitted.
305
WGUS81 KPHI 130534
FLSPHI
Flood Advisory
National Weather Service Mount Holly NJ
134 AM EDT Tue Jul 13 2021
PAC011-029-091-130845-
/O.NEW.KPHI.FA.Y.0079.210713T0534Z-210713T0845Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Chester PA-Montgomery PA-
134 AM EDT Tue Jul 13 2021
The National Weather Service in Mount Holly has issued a
* Flood Advisory for...
Berks County in eastern Pennsylvania...
North Central Chester County in southeastern Pennsylvania...
Northwestern Montgomery County in southeastern Pennsylvania...
* Until 445 AM EDT.
* At 134 AM EDT, Doppler radar indicated heavy rain due to
thunderstorms. Minor flooding is ongoing or expected to begin
shortly in the advisory area. Radar has estimated that between 1
and 2 inches of rain have fallen, and an additional inch or so is
possible.
* Some locations that will experience flooding include...
Reading, Pottstown, Wyomissing, Birdsboro, Hamburg, Fleetwood,
Sinking Spring, Laureldale, Womelsdorf, Wernersville, Robesonia,
and Leesport.
This includes the following highways...
Pennsylvania Turnpike between mile markers 296 and 303.
Interstate 78 in Pennsylvania between mile markers 10 and 31.
Interstate 176 in Pennsylvania between mile markers 1 and 11.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Be aware of your surroundings and do not drive on flooded roads.
Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.
&&
LAT...LON 4058 7601 4030 7559 4008 7587 4012 7592
4014 7587 4014 7588 4031 7615 4036 7621
4037 7623 4050 7644 4052 7634 4052 7624
4057 7608 4058 7607 4057 7605 4058 7604
4057 7602
$$
MPS1 follow-up statement
890
WGUS81 KPHI 130731
FLSPHI
Flood Advisory
National Weather Service Mount Holly NJ
331 AM EDT Tue Jul 13 2021
PAC011-029-091-130741-
/O.CAN.KPHI.FA.Y.0079.000000T0000Z-210713T0845Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Chester PA-Montgomery PA-
331 AM EDT Tue Jul 13 2021
...FLOOD ADVISORY IS CANCELLED FOR BERKS, NORTH CENTRAL CHESTER, AND
NORTHWESTERN MONTGOMERY COUNTIES...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
LAT...LON 4058 7601 4030 7559 4008 7587 4012 7592
4014 7587 4014 7588 4031 7615 4036 7621
4037 7623 4050 7644 4052 7634 4052 7624
4057 7608 4058 7607 4057 7605 4058 7604
4057 7602
$$
MPSThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 12, 8:37 PM EDT | Areal Flood Warning | PHI | Bucks, Philadelphia | 9 hr |
| Jul 13, 3:44 PM EDT | Dense Fog Advisory | PHI | Bucks, Monroe, Northampton | 14 hr |
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.