Alert archive / Pennsylvania / Flash Flood Warnings in 2018

Flash Flood Warning 81, NWS Philadelphia/Mount Holly

August 31, 2018Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 31, 2018, 10:09 AM EDT for Berks County, Pennsylvania. It was in force for 7 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 31, 2018, 10:09 AM EDT (14:09 UTC)
Expired
Aug 31, 2018, 5:15 PM EDT
In force
7 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

County Berks County, PA

The radar

The State College radar (KCCX), 161 km from the middle of the area, began a volume at 14:13 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 12:00Z, 2.2 hours before the alert went out and 204 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 2018-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 425 joules per kilogram.LCLLFCEL10008507005003002001001 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 2018-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 square meters per square second.1939Sfc1 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
425 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
930 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
68 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

467 
WGUS51 KPHI 311409
FFWPHI
PAC011-311715-
/O.NEW.KPHI.FF.W.0081.180831T1409Z-180831T1715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1009 AM EDT FRI AUG 31 2018

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Northwestern Berks County in eastern Pennsylvania...

* Until 115 PM EDT.

* At 1007 AM EDT, Doppler radar indicated heavy rain in Lebanon 
  County moving slowly northeast into northwestern Berks Couny. Over 
  two inches of rain is possible in a short period of time, which 
  will result in flash flooding in portions of the warned area.

* Some locations that could experience flooding include...
  Hamburg, Womelsdorf, Shoemakersville, Bernville, Strausstown and
  Centerport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4052 7634 4052 7625 4054 7617 4056 7613
      4058 7605 4057 7602 4059 7601 4051 7593
      4034 7617 4049 7643

$$

jjm
3 follow-up statements
828 
WGUS71 KPHI 311621
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1221 PM EDT FRI AUG 31 2018

PAC011-311715-
/O.CON.KPHI.FF.W.0081.000000T0000Z-180831T1715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
1221 PM EDT FRI AUG 31 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 115 PM EDT FOR
NORTHWESTERN BERKS COUNTY...

At 1219 PM EDT, Doppler radar indicated heavy rain across portions 
of the warned area, with radar-estimated rainfall totals up to 3 
inches since earlier this morning in the far northwestern portions 
of the county. The flash flood warning remains in effect. 

Some locations that could experience flooding 
include... Hamburg, Womelsdorf, Shoemakersville, Bernville, 
Strausstown and Centerport.

LAT...LON 4052 7634 4052 7625 4054 7617 4056 7613
      4058 7605 4057 7602 4059 7601 4051 7593
      4034 7617 4049 7643

$$

jjm
600 
WGUS51 KPHI 311701
FFWPHI
PAC011-312115-
/O.EXT.KPHI.FF.W.0081.000000T0000Z-180831T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
101 PM EDT FRI AUG 31 2018

The National Weather Service in Mount Holly NJ has extended the

* Flash Flood Warning for...
  Northwestern Berks County in eastern Pennsylvania...

* Until 515 PM EDT.

* At 1258 PM EDT, Doppler radar estimated over 2 inches of rain in 
  northwestern Berks County since this morning. An additional one to 
  three inches of rain is on the way. Flash flooding is expected.

* Some locations that could experience flooding include...
  Hamburg, Womelsdorf, Shoemakersville, Bernville, Strausstown and
  Centerport.

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 4052 7634 4052 7625 4054 7617 4056 7613
      4058 7605 4057 7602 4059 7601 4051 7593
      4034 7617 4049 7643

$$

jjm
093 
WGUS71 KPHI 312109
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
509 PM EDT FRI AUG 31 2018

PAC011-312117-
/O.EXP.KPHI.FF.W.0081.000000T0000Z-180831T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
509 PM EDT FRI AUG 31 2018

...THE FLASH FLOOD WARNING FOR NORTHWESTERN BERKS COUNTY WILL EXPIRE
AT 515 PM EDT...

The heavy rain has ended. Flash Flooding is no longer expected to 
pose a threat, however, many local creeks and stream continue to run 
high and the Schuylkill River continues to rise. An Areal Flood 
Warning will be issued for any residual flooding. Please continue to 
heed any remaining road closures.

LAT...LON 4052 7634 4052 7625 4054 7617 4056 7613
      4058 7605 4057 7602 4059 7601 4051 7593
      4034 7617 4049 7643

$$

Robertson

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 31, 6:52 AM EDTAreal Flood AdvisoryPHIPhiladelphia4 hr
Aug 31, 7:55 AM EDTAreal Flood AdvisoryPHIDelaware3 hr
Aug 31, 10:14 AM EDTAreal Flood AdvisoryPHIChester3 hr
Aug 31, 1:22 PM EDTAreal Flood AdvisoryPHIBerks, Carbon, Lehigh, Monroe, Northampton4 hr
Aug 31, 1:54 PM EDTAreal Flood AdvisoryPHIBerks, Chester, Lehigh, Montgomery4 hr
Aug 31, 3:59 PM EDTFlash Flood WarningPHIBerks, Chester4 hr
Aug 31, 5:13 PM EDTAreal Flood WarningPHIBerks7 hr

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.