Alert archive / Pennsylvania / Flash Flood Warnings in 2020

Flash Flood Warning 23, NWS Philadelphia/Mount Holly

July 12, 2020Berks County, Lehigh County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 12, 2020, 6:54 PM EDT for Berks County, Lehigh County, Pennsylvania. It was in force for 3 hr. 3 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
Jul 12, 2020, 6:54 PM EDT (22:54 UTC)
Expired
Jul 12, 2020, 10:00 PM EDT
In force
3 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), 141 km from the middle of the area, began a volume at 22:56 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
Jul 12, 8:37 PM EDTHEAVY RAIN 0.83 Sw Ruscombmanor Twp, PAFELL WITHIN A 15 MIN PERIOD.
Jul 12, 8:41 PM EDTHEAVY RAIN 1.44Reading Regional Airpor, PATOTAL AMOUNT. 0.98 FELL WITHIN 45 MIN.
Jul 12, 9:16 PM EDTHEAVY RAIN 1.39West Lawn, PA0.7 FELL IN 15 MIN. BETWEEN 630 AND 645 PM EDT.

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, 10.9 hours before the alert went out and 208 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 2020-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2020-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -2 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1747 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
-2 m²/s²
0-3 km storm-relative helicity
-7 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

525 
WGUS51 KPHI 122254
FFWPHI
PAC011-077-130200-
/O.NEW.KPHI.FF.W.0023.200712T2254Z-200713T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
654 PM EDT Sun Jul 12 2020

The National Weather Service in Mount Holly NJ has issued a

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

* Until 1000 PM EDT.

* At 653 PM EDT, trained weather spotters reported thunderstorms
  producing heavy rain across the warned area. Up to one inch of rain
  has already fallen. Flash flooding is ongoing or expected to begin
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Trained weather spotters.

  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 could experience flooding include...
  Reading, Emmaus, Wyomissing, Kutztown, Fleetwood, Sinking Spring,
  Laureldale, Womelsdorf, Wernersville, Topton, Robesonia, Leesport,
  Shoemakersville, Bernville, Lyons, Lenhartsville, Spring Ridge,
  Zionsville, Ancient Oaks and Fairview Hgts.

Additional rainfall amounts of one to two inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

&&

LAT...LON 4066 7576 4050 7547 4020 7597 4031 7614
      4036 7621 4038 7625

FLASH FLOOD...OBSERVED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

SFJ
4 follow-up statements
818 
WGUS51 KPHI 122258 CCA
FFWPHI
PAC011-077-130200-
/O.COR.KPHI.FF.W.0023.200712T2254Z-200713T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
658 PM EDT Sun Jul 12 2020

The National Weather Service in Mount Holly NJ has issued a

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

* Until 1000 PM EDT.

* At 657 PM EDT, Doppler radar and automated gauges indicated
  thunderstorms producing heavy rain across the warned area. Up to
  one inch of rain has already fallen. Flash flooding is ongoing or
  expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar and automated gauges.

  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 could experience flooding include...
  Reading, Emmaus, Wyomissing, Kutztown, Fleetwood, Sinking Spring,
  Laureldale, Womelsdorf, Wernersville, Topton, Robesonia, Leesport,
  Shoemakersville, Bernville, Lyons, Lenhartsville, Spring Ridge,
  Zionsville, Ancient Oaks and Fairview Hgts.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

&&

LAT...LON 4066 7576 4050 7547 4020 7597 4031 7614
      4036 7621 4038 7625

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

SFJ
188 
WGUS71 KPHI 122326
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
726 PM EDT Sun Jul 12 2020

PAC077-122336-
/O.CAN.KPHI.FF.W.0023.000000T0000Z-200713T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lehigh PA-
726 PM EDT Sun Jul 12 2020

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN LEHIGH COUNTY IS
CANCELLED...

Flooding is no longer expected to pose a threat. Please continue to
heed any remaining road closures.

LAT...LON 4053 7581 4041 7562 4020 7597 4031 7614
      4036 7621 4038 7625

$$

PAC011-130200-
/O.CON.KPHI.FF.W.0023.000000T0000Z-200713T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
726 PM EDT Sun Jul 12 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1000 PM EDT FOR
CENTRAL BERKS COUNTY...

At 726 PM EDT, Doppler radar and automated gauges indicated
thunderstorms producing heavy rain across the warned area. Up to one
inch of rain has already fallen. Flash flooding is ongoing or
expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar and automated gauges.

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 could experience flooding include...
Reading, Wyomissing, Kutztown, Fleetwood, Sinking Spring, Laureldale,
Womelsdorf, Wernersville, Robesonia, Leesport, Lyons, Spring Ridge,
Fairview Hgts, Shillington, West Reading, Mount Penn, Mohnton,
Kenhorst, St. Lawrence and West Lawn.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 4053 7581 4041 7562 4020 7597 4031 7614
      4036 7621 4038 7625

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

SFJ
591 
WGUS71 KPHI 130021
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
821 PM EDT Sun Jul 12 2020

PAC011-130200-
/O.CON.KPHI.FF.W.0023.000000T0000Z-200713T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
821 PM EDT Sun Jul 12 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1000 PM EDT FOR
CENTRAL BERKS COUNTY...

At 819 PM EDT, Doppler radar and automated gauges indicated the 
thunderstorms that produced heavy rain earlier had left the warned 
area. However, it will take time for the water to recede and 
additional light rain showers are possible. Up to two inches of rain 
have already fallen. Flash flooding is ongoing or expected to begin 
shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar and automated gauges.

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 could experience flooding include...
Reading, Wyomissing, Kutztown, Fleetwood, Sinking Spring, Laureldale,
Womelsdorf, Wernersville, Robesonia, Leesport, Lyons, Spring Ridge,
Fairview Hgts, Shillington, West Reading, Mount Penn, Mohnton,
Kenhorst, St. Lawrence and West Lawn.

Additional rainfall amounts of up to one inch are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 4053 7581 4041 7562 4020 7597 4031 7614
      4036 7621 4038 7625

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

SFJ
926 
WGUS71 KPHI 130151
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
951 PM EDT Sun Jul 12 2020

PAC011-130200-
/O.EXP.KPHI.FF.W.0023.000000T0000Z-200713T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
951 PM EDT Sun Jul 12 2020

...THE FLASH FLOOD WARNING FOR CENTRAL BERKS COUNTY WILL EXPIRE AT
1000 PM EDT...

The heavy rain is ending. Additional rain is possible, but it should 
be light. Therefore, flooding is no longer expected to pose a 
threat. Please continue to heed any remaining road closures.

LAT...LON 4053 7581 4041 7562 4020 7597 4031 7614
      4036 7621 4038 7625

$$

SFJ

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 12, 6:26 PM EDTSpecial Weather StatementPHIBerks34 min
Jul 12, 6:56 PM EDTSpecial Weather StatementPHIBerks, Lehigh34 min
Jul 12, 7:28 PM EDTSpecial Weather StatementPHICarbon32 min
Jul 12, 7:31 PM EDTAreal Flood AdvisoryPHICarbon, Monroe4 hr
Jul 12, 7:51 PM EDTSpecial Weather StatementPHIMonroe24 min

Nearby

Flash Flood Warnings in Pennsylvania, 2020Every flash flood warning in 2020

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.