Alert archive / Pennsylvania / Flash Flood Warnings in 2018

Flash Flood Warning 38, NWS Philadelphia/Mount Holly

July 22, 2018Berks County, Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 22, 2018, 8:54 PM EDT for Berks County, Chester County, Pennsylvania. It was in force for 4 hr. 1 report 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 22, 2018, 8:54 PM EDT (00:54 UTC)
Expired
Jul 23, 2018, 1:00 AM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Berks County, PA, Chester County, PA

The radar

The Philadelphia radar (KDIX), 143 km from the middle of the area, began a volume at 00:57 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 22, 10:30 PM EDTHEAVY RAIN 2.76Warwick, PA

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 00:00Z, 0.9 hours before the alert went out and 209 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 00:00Z on 2018-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1533 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 2018-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 83 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
1533 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
664 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
83 m²/s²
0-3 km storm-relative helicity
147 m²/s²
Significant tornado parameter
0.8
Supercell composite
5.5

Open this sounding in Storm Lab

The text

As transmitted.

811 
WGUS51 KPHI 230054
FFWPHI
PAC011-029-230500-
/O.NEW.KPHI.FF.W.0038.180723T0054Z-180723T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
854 PM EDT SUN JUL 22 2018

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Berks County in eastern Pennsylvania...
  North central Chester County in southeastern Pennsylvania...

* Until 100 AM EDT.

* At 852 PM EDT, Doppler radar indicated an area of showers and 
  thunderstorms producing very heavy rain moving north across the 
  warned area. A quick 1 to 2 inches of rain will fall, which is on 
  top of the earlier heavy rain. Flash flooding is expected to begin 
  shortly in the areas of heaviest rain.

* Some locations that could experience flooding include...
  Reading, Wyomissing, Birdsboro, Kutztown, Hamburg, Fleetwood,
  Sinking Spring, Laureldale, Wernersville, Topton, Leesport,
  Shoemakersville, Elverson, Bernville, Lyons, Lenhartsville, New
  Morgan, Spring Ridge, Fairview Hgts and Shillington.

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 4058 7605 4057 7602 4063 7600 4068 7589
      4052 7565 4013 7573 4014 7588 4028 7609
      4056 7612

$$

Gorse
2 follow-up statements
589 
WGUS71 KPHI 230135
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
935 PM EDT SUN JUL 22 2018

PAC011-029-230500-
/O.CON.KPHI.FF.W.0038.000000T0000Z-180723T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Chester PA-
935 PM EDT SUN JUL 22 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 100 AM EDT FOR
BERKS AND NORTH CENTRAL CHESTER COUNTIES...

At 934 PM EDT, Doppler radar indicated showers and thunderstorms 
producing very heavy rain continues to move cross the warned area. A 
quick 1 to 2 inches of rain can fall, resulting in flash flooding.

Some locations that could experience flooding include...
Reading, Wyomissing, Birdsboro, Kutztown, Hamburg, Fleetwood, Sinking
Spring, Laureldale, Wernersville, Topton, Leesport, Shoemakersville,
Elverson, Bernville, Lyons, Lenhartsville, New Morgan, Spring Ridge,
Fairview Hgts and Shillington.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4058 7605 4057 7602 4063 7600 4068 7589
      4052 7565 4013 7573 4014 7588 4028 7609
      4056 7612

$$

Gorse
489 
WGUS71 KPHI 230454
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1254 AM EDT MON JUL 23 2018

PAC011-029-230502-
/O.EXP.KPHI.FF.W.0038.000000T0000Z-180723T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Chester PA-
1254 AM EDT MON JUL 23 2018

...THE FLASH FLOOD WARNING FOR BERKS AND NORTH CENTRAL CHESTER
COUNTIES WILL EXPIRE AT 100 AM EDT...

The heavy rains has ended. There will still be scattered showers 
overnight. Flooding is no longer expected to pose a threat. Please 
continue to heed any remaining road closures.

LAT...LON 4058 7605 4057 7602 4063 7600 4068 7589
      4052 7565 4013 7573 4014 7588 4028 7609
      4056 7612

$$

PO

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 22, 8:18 PM EDTAreal Flood WarningPHIChester117 min
Jul 22, 8:43 PM EDTFlash Flood WarningPHIChester4 hr
Jul 22, 9:40 PM EDTFlash Flood WarningPHILehigh3 hr
Jul 22, 10:21 PM EDTSpecial Weather StatementPHIMonroe54 min
Jul 22, 11:18 PM EDTAreal Flood AdvisoryPHICarbon, Monroe, Northampton3 hr
Jul 23, 12:19 AM EDTRiver Flood WarningPHIChester5 hr
Jul 23, 3:45 AM EDTFlash Flood WatchPHIBerks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more68 hr
Jul 23, 7:00 AM EDTRiver Flood WarningPHIChester, Delaware9 hr
Jul 23, 12:58 PM EDTSpecial Weather StatementPHIChester32 min
Jul 23, 1:01 PM EDTAreal Flood AdvisoryPHIChester34 min

Nearby

Flash Flood Warnings in Pennsylvania, 2018Every flash flood warning in 2018

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.