Alert archive / Pennsylvania / Areal Flood Warnings in 2021

Areal Flood Warning 32, NWS Philadelphia/Mount Holly

September 1, 2021Berks County, Lehigh County, Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood warning at Sep 1, 2021, 7:23 PM EDT for Berks County, Lehigh County, Pennsylvania. It was in force for 14 hr. 11 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
Sep 1, 2021, 7:23 PM EDT (23:23 UTC)
Expired
Sep 2, 2021, 9:45 AM EDT
In force
14 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Berks County, PA, Lehigh County, PA

The radar

The Philadelphia radar (KDIX), 150 km from the middle of the area, began a volume at 23:23 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

TimeReportWhereRemark
Sep 1, 7:45 PM EDTFLOOD2 Wnw Richmond Twp, PAMAIDENCREEK ROAD CLOSED FROM FLOODING NEAR CHURCH HILL ROAD. TIME BASED ON DISPATCH REPORT.
Sep 1, 7:56 PM EDTFLOODShartlesville, PAPORTIONS OF I-78 WITH LANE RESTRICTIONS OR CLOSED FROM FLOODING NEAR SHARTLESVILLE. TIME BASED ON DISPATCH REPORT.
Sep 1, 8:00 PM EDTFLOOD2 Nw Shoemakersville, PATHE GAUGE ON THE SCHUYLKILL RIVER AT BERNE (BREP1) REACHED FLOOD STAGE AT 800 PM 9/1, CRESTING AT 15.67 FEET (MODERATE FLOODING) AT 230 AM 9/2.
Sep 1, 8:00 PM EDTFLOOD3 Wnw Robeson Twp, PAFLOODING ON STATE ROUTE 10 WEST OF INTERSTATE 176 FORCED ITS CLOSURE. TIME BASED ON DISPATCH REPORT.
Sep 1, 8:32 PM EDTFLOOD2 Ese Mohnton, PAFLOODING ON STATE ROUTE 625 NEAR MOUNT PENN ROAD FORCED ITS CLOSURE. TIME BASED ON DISPATCH REPORT.
Sep 1, 8:36 PM EDTFLOOD1 E Temple, PAFLOODING OF MOUNT LAUREL ROAD AND LEESPORT AVENUE FORCED THEIR CLOSURES. TIME BASED ON DISPATCH REPORT.
Sep 1, 9:45 PM EDTFLOOD2 Wnw Robeson Twp, PAFLOODING CLOSED ROUTE 568 NEAR INTERSTATE 176. TIME BASED ON DISPATCH REPORT.
Sep 1, 10:45 PM EDTFLOODMount Aetna, PAFLOODING CLOSED STATE ROUTE 501 IN MOUNT AETNA. TIME BASED ON DISPATCH REPORT.
Sep 1, 11:09 PM EDTFLOOD3 Sse Lenhartsville, PAFLOODING ON CRYSTAL CAVE ROAD AND KUTZTOWN ROAD FORCED THEIR CLOSURES. TIME BASED ON DISPATCH REPORT.
Sep 2, 12:20 AM EDTFLOOD3 Wnw Mount Aetna, PAFLOODING ON LITTLE SWATARA CREEK CLOSED LITTLE MOUNTAIN ROAD. TIME BASED ON DISPATCH REPORT.
Sep 2, 6:00 AM EDTFLOOD1 E West Reading, PATHE GAUGE ON THE SCHUYLKILL RIVER AT READING (RDRP1) REACHED FLOOD STAGE AT 600 AM 9/2, CRESTING AT 17.02 FEET (MINOR FLOODING) AT 1030 AM 9/2.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.4 hours before the alert went out and 207 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.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2021-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 558 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2021-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 122 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
558 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
575 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
122 m²/s²
0-3 km storm-relative helicity
223 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.6

Open this sounding in Storm Lab

The text

As transmitted.

053 
WGUS41 KPHI 012323
FLWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
723 PM EDT Wed Sep 1 2021

PAC011-077-020215-
/O.NEW.KPHI.FA.W.0032.210901T2323Z-210902T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Lehigh PA-
723 PM EDT Wed Sep 1 2021

The National Weather Service in Mount Holly has issued a

* Flood Warning for...
  Berks County in eastern Pennsylvania...
  Southwestern Lehigh County in eastern Pennsylvania...

* Until 1015 PM EDT.

* At 723 PM EDT, Doppler radar indicated heavy rain due to 
  thunderstorms. Flooding is ongoing or expected to begin shortly in 
  Reading area. Between 2 and 4 inches of rain have fallen. Numerous 
  small creeks and streams are likely flooding, so use caution.

* Some locations that may experience flooding include...
  Reading, Wyomissing, Birdsboro, Kutztown, Hamburg, Fleetwood, 
  Sinking Spring, Laureldale, Womelsdorf, Wernersville, Topton, and 
  Robesonia.

This includes the following highways...
	Pennsylvania Turnpike between mile markers 296 and 298.
	Interstate 78 in Pennsylvania between mile markers 10 and 45.
	Interstate 176 in Pennsylvania between mile markers 1 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

&&

LAT...LON 4068 7589 4051 7562 4024 7573 4015 7590
      4031 7615 4036 7621 4050 7643 4052 7633
      4052 7624 4058 7604 4057 7602 4064 7599

$$

NC
3 follow-up statements
886 
WGUS41 KPHI 020132
FLWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
932 PM EDT Wed Sep 1 2021

PAC011-077-020415-
/O.EXT.KPHI.FA.W.0032.000000T0000Z-210902T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Lehigh PA-
932 PM EDT Wed Sep 1 2021

The National Weather Service in Mount Holly has extended the

* Flood Warning for...
  Berks County in eastern Pennsylvania...
  Southwestern Lehigh County in eastern Pennsylvania...

* Until 1215 AM EDT.

* At 932 PM EDT, Doppler radar indicated heavy rain due to 
  thunderstorms. Flooding is ongoing or expected to begin shortly in 
  portions of Berks County. Between 4 and 6 inches of rain have 
  fallen. Numerous creeks and small streams are in flood including 
  Spangsville near Manatawny Creek, and many tributaries of the 
  Schuylkill

* Some locations that may experience flooding include...
  Reading, Wyomissing, Birdsboro, Kutztown, Hamburg, Fleetwood, 
  Sinking Spring, Laureldale, Womelsdorf, Wernersville, Topton, and 
  Robesonia.

This includes the following highways...
	Pennsylvania Turnpike between mile markers 296 and 298.
	Interstate 78 in Pennsylvania between mile markers 10 and 45.
	Interstate 176 in Pennsylvania between mile markers 1 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

Motorists should not attempt to drive around barricades or drive 
cars through flooded areas.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 4068 7589 4051 7562 4024 7573 4015 7590
      4031 7615 4036 7621 4050 7643 4052 7633
      4052 7624 4058 7604 4057 7602 4064 7599

$$

NC
782 
WGUS41 KPHI 020354
FLWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
1154 PM EDT Wed Sep 1 2021

PAC011-077-021345-
/O.EXT.KPHI.FA.W.0032.000000T0000Z-210902T1345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Lehigh PA-
1154 PM EDT Wed Sep 1 2021

The National Weather Service in Mount Holly has extended the

* Flood Warning for...
  Berks County in eastern Pennsylvania...
  Southwestern Lehigh County in eastern Pennsylvania...

* Until 945 AM EDT Thursday.

* At 1154 PM EDT, local law enforcement reported flooding across the 
  warning area. Several roads are closed, and a number of rivers and 
  streams remain in flood. Flooding will continue through the night. 
  Please continue to heed road closures.

* Some locations that may experience flooding include...
  Reading, Wyomissing, Birdsboro, Kutztown, Hamburg, Fleetwood, 
  Sinking Spring, Laureldale, Womelsdorf, Wernersville, Topton, and 
  Robesonia.

This includes the following highways...
	Pennsylvania Turnpike between mile markers 296 and 298.
	Interstate 78 in Pennsylvania between mile markers 10 and 45.
	Interstate 176 in Pennsylvania between mile markers 1 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

&&

LAT...LON 4068 7589 4051 7562 4024 7573 4015 7590
      4031 7615 4036 7621 4050 7643 4052 7633
      4052 7624 4058 7604 4057 7602 4064 7599

$$

CMS
851 
WGUS81 KPHI 021341
FLSPHI

Flood Statement
National Weather Service Mount Holly NJ
941 AM EDT Thu Sep 2 2021

PAC011-077-021351-
/O.EXP.KPHI.FA.W.0032.000000T0000Z-210902T1345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Lehigh PA-
941 AM EDT Thu Sep 2 2021

...FLOOD WARNING WILL EXPIRE AT 945 AM EDT THIS MORNING FOR BERKS 
AND SOUTHWESTERN LEHIGH COUNTIES...

This flood warning will be allowed to expire. Additional flood 
warnings remain in place for the area. The Schuylkill River is still 
in flood.

LAT...LON 4068 7589 4051 7562 4024 7573 4015 7590
      4031 7615 4036 7621 4050 7643 4052 7633
      4052 7624 4058 7604 4057 7602 4064 7599

$$

Kruzdlo

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 1, 6:19 AM EDTAreal Flood AdvisoryPHIChester, Delaware116 min
Sep 1, 6:49 AM EDTFlash Flood WarningPHIChester, Delaware, Philadelphia86 min
Sep 1, 11:24 AM EDTAreal Flood AdvisoryPHIBerks, Carbon, Lehigh, Monroe, Northampton3 hr
Sep 1, 12:07 PM EDTFlash Flood WarningPHICarbon, Monroe4 hr
Sep 1, 1:29 PM EDTFlash Flood WarningPHIBerks, Lehigh6 hr
Sep 1, 2:53 PM EDTFlash Flood WarningPHIBerks, Chester, Delaware, Montgomery9 hr
Sep 1, 3:55 PM EDTRiver Flood WarningPHIMontgomery36 hr
Sep 1, 3:55 PM EDTRiver Flood WarningPHIChester, Montgomery, Philadelphia43 hr
Sep 1, 3:55 PM EDTRiver Flood WarningPHIMontgomery, Philadelphia41 hr
Sep 1, 3:55 PM EDTRiver Flood WarningPHIPhiladelphia39 hr
Sep 1, 3:55 PM EDTRiver Flood WarningPHIBerks24 hr
Sep 1, 4:02 PM EDTRiver Flood WarningPHIMonroe24 hr
Sep 1, 4:04 PM EDTAreal Flood WarningPHICarbon, Monroe, Northampton24 hr
Sep 1, 4:10 PM EDTRiver Flood WarningPHIMonroe19 hr
Sep 1, 4:12 PM EDTFlash Flood WarningPHIBerks, Bucks, Lehigh, Montgomery, Northampton7 hr
Sep 1, 4:12 PM EDTRiver Flood WarningPHILehigh, Northampton25 hr
Sep 1, 4:12 PM EDTRiver Flood WarningPHILehigh, Northampton24 hr
Sep 1, 4:12 PM EDTRiver Flood WarningPHICarbon15 hr
Sep 1, 4:13 PM EDTTornado WarningPHIChester32 min
Sep 1, 4:20 PM EDTRiver Flood WarningPHIMontgomery22 hr
Sep 1, 4:21 PM EDTRiver Flood WarningPHIBucks29 hr
Sep 1, 4:42 PM EDTFlash Flood Warning EmergencyConsiderable damage threatPHIChester, Delaware, Montgomery6 hr
Sep 1, 5:07 PM EDTRiver Flood WarningPHIChester17 hr
Sep 1, 5:13 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia47 min
Sep 1, 5:15 PM EDTTornado WarningPHIDelaware, Montgomery, Philadelphia30 min
Sep 1, 5:26 PM EDTFlash Flood WarningPHIBucks, Delaware, Montgomery, Philadelphia9 hr
Sep 1, 5:34 PM EDTTornado WarningPHIBucks, Montgomery, Philadelphia26 min
Sep 1, 5:42 PM EDTFlash Flood WarningPHIBucks10 hr
Sep 1, 5:57 PM EDTTornado WarningPHIBucks33 min
Sep 1, 6:08 PM EDTFlash Flood WarningPHIMonroe, Northampton6 hr
Sep 1, 6:20 PM EDTTornado WarningPHIBucks40 min
Sep 1, 6:22 PM EDTTornado Warning Tornado observedPHIPhiladelphia23 min
Sep 1, 6:38 PM EDTRiver Flood WarningPHIChester, Delaware26 hr
Sep 1, 6:42 PM EDTTornado WarningPHIBucks, Philadelphia33 min
Sep 1, 6:59 PM EDTSevere Thunderstorm WarningPHIBucks61 min
Sep 1, 7:04 PM EDTTornado Warning EmergencyTornado observedCatastrophic damage threatPHIBucks26 min
Sep 1, 7:05 PM EDTFlash Flood Warning EmergencyCatastrophic damage threatPHIBucks8 hr
Sep 1, 7:22 PM EDTTornado WarningPHIBucks11 min
Sep 1, 7:31 PM EDTFlash Flood Warning EmergencyCatastrophic damage threatPHIBucks4 hr
Sep 1, 7:53 PM EDTRiver Flood WarningPHIDelaware13 hr

Nearby

Areal Flood Warnings in Pennsylvania, 2021Every areal 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.