Alert archive / Pennsylvania / Flash Flood Warnings in 2018

Flash Flood Warning 75, NWS Philadelphia/Mount Holly

August 17, 2018Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 17, 2018, 6:40 PM EDT for Berks County, Pennsylvania. It was in force for 2 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: Aug 17, 2018, 6:40 PM EDT (22:40 UTC)
Expired: Aug 17, 2018, 9:08 PM EDT
In force: 2 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

County Berks County, PA

The radar

The Philadelphia radar (KDIX), 155 km from the middle of the area, began a volume at 22:41 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

Time	Report	Where	Remark
Aug 17, 8:02 PM EDT	FLOOD	1 Sse Berkley, PA	LEESPORT AVENUE FLOODED.

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, 10.7 hours before the alert went out and 203 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 750 J/kg
Mixed-layer CIN: -101 J/kg
Mixed-layer LCL: 1186 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 80 m²/s²
0-3 km storm-relative helicity: 69 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

416 
WGUS51 KPHI 172240
FFWPHI
PAC011-180245-
/O.NEW.KPHI.FF.W.0075.180817T2240Z-180818T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
640 PM EDT FRI AUG 17 2018

The National Weather Service in Mount Holly NJ has issued a

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

* Until 1045 PM EDT.

* At 639 PM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to one inch of rain has 
  already fallen in the last half hour. 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, Womelsdorf, Wernersville, Newmanstown,
  Topton, Leesport, Shoemakersville, Bernville, Lyons, Strausstown,
  Lenhartsville, New Morgan and Spring Ridge.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Stay away or be swept away. River banks and culverts can become
unstable and unsafe.

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 4052 7634 4052 7625 4058 7605 4057 7602
      4064 7598 4068 7589 4049 7560 4015 7589
      4031 7614 4036 7621 4037 7623 4049 7643

$$

JRK

2 follow-up statements

670 
WGUS71 KPHI 180005
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
805 PM EDT FRI AUG 17 2018

PAC011-180245-
/O.CON.KPHI.FF.W.0075.000000T0000Z-180818T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
805 PM EDT FRI AUG 17 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM EDT FOR
BERKS COUNTY...

At 759 PM EDT, Doppler radar and automated rain gauges indicated 1 
to 2 inches of rain fell from the thunderstorms that moved over the 
warned area since late this afternoon. Even though the heavy rain 
has already ended, the area will still be susceptible to flash 
flooding this evening given the recent rounds of heavy rainfall that 
have occurred over the past few weeks.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Stay away or be swept away. River banks and culverts can become
unstable and unsafe.

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 4043 7633 4052 7625 4058 7605 4057 7602
      4064 7598 4068 7589 4056 7570 4037 7571
      4021 7598 4031 7614 4036 7621 4037 7623

$$

JRK

883 
WGUS71 KPHI 180108
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
908 PM EDT FRI AUG 17 2018

PAC011-180117-
/O.CAN.KPHI.FF.W.0075.000000T0000Z-180818T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
908 PM EDT FRI AUG 17 2018

...THE FLASH FLOOD WARNING FOR BERKS COUNTY IS CANCELLED...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat to life and property. Please continue to heed any remaining 
road closures as localized poor drainage flooding may linger through 
the remainder of the evening.

LAT...LON 4043 7633 4052 7625 4058 7605 4057 7602
      4064 7598 4068 7589 4056 7570 4037 7571
      4021 7598 4031 7614 4036 7621 4037 7623

$$

JRK

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 17, 2:21 PM EDT	Special Weather Statement	PHI	Lehigh	24 min
Aug 17, 4:29 PM EDT	Special Weather Statement	PHI	Berks	46 min
Aug 17, 5:07 PM EDT	Special Weather Statement	PHI	Berks, Lehigh	53 min
Aug 17, 5:12 PM EDT	Special Weather Statement	PHI	Berks	33 min
Aug 17, 5:36 PM EDT	Special Weather Statement	PHI	Lehigh, Northampton	39 min
Aug 17, 5:59 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	31 min
Aug 17, 6:00 PM EDT	Special Weather Statement	PHI	Carbon	30 min
Aug 17, 6:18 PM EDT	Special Weather Statement	PHI	Berks	27 min
Aug 17, 6:19 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	41 min
Aug 17, 6:22 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	38 min
Aug 17, 6:23 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	52 min
Aug 17, 7:09 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Carbon, Chester, Lehigh, Monroe and 2 more	51 min
Aug 17, 7:15 PM EDT	Special Weather Statement	PHI	Pike	15 min
Aug 17, 7:34 PM EDT	Special Weather Statement	PHI	Carbon	26 min
Aug 17, 7:39 PM EDT	Special Weather Statement	PHI	Monroe	51 min
Aug 17, 7:42 PM EDT	Special Weather Statement	PHI	Bucks, Northampton	33 min

Nearby

Flash Flood Warnings in Pennsylvania, 2018 Every 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.