Alert archive / Pennsylvania / Flash Flood Warnings in 2023

Flash Flood Warning 82, NWS Philadelphia/Mount Holly

September 9, 2023Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 9, 2023, 8:29 PM EDT for Berks County, Pennsylvania. It was in force for 2 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: Sep 9, 2023, 8:29 PM EDT (00:29 UTC)
Expired: Sep 9, 2023, 10:43 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), 153 km from the middle of the area, began a volume at 00:30 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 00:00Z, 0.5 hours before the alert went out and 206 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: 2 J/kg
Mixed-layer CIN: -207 J/kg
Mixed-layer LCL: 1084 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 58 m²/s²
0-3 km storm-relative helicity: 52 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

649 
WGUS51 KPHI 100029
FFWPHI
PAC011-100315-
/O.NEW.KPHI.FF.W.0082.230910T0029Z-230910T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
829 PM EDT Sat Sep 9 2023

The National Weather Service in Mount Holly has issued a

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

* Until 1115 PM EDT.

* At 829 PM EDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  1 and 2 inches of rain have fallen. The expected rainfall rate is 
  1 to 2 inches in 1 hour. Additional rainfall amounts of 1 to 2 
  inches are possible in the warned area. 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 may experience flash flooding include...
  Reading, Wyomissing, Hamburg, Sinking Spring, Laureldale, 
  Womelsdorf, Wernersville, Robesonia, Leesport, Shoemakersville, 
  Bernville, and Strausstown.

This includes the following highways...
	Pennsylvania Turnpike near mile marker 296.
	Interstate 78 in Pennsylvania between mile markers 14 and 37.
	Interstate 176 in Pennsylvania between mile markers 2 and 11.

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 4067 7590 4053 7585 4018 7590 4017 7593
      4031 7615 4036 7621 4041 7630 4052 7631
      4052 7626 4054 7617 4057 7608 4058 7607
      4057 7605 4058 7604 4057 7602 4064 7599

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

$$

Staarmann

2 follow-up statements

842 
WGUS71 KPHI 100121
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
921 PM EDT Sat Sep 9 2023

PAC011-100315-
/O.CON.KPHI.FF.W.0082.000000T0000Z-230910T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
921 PM EDT Sat Sep 9 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1115 PM EDT THIS 
EVENING FOR CENTRAL BERKS COUNTY...

At 921 PM EDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 
1.5 and 2.5 inches of rain have fallen. Across northern Berks 
County, upwards of 3 to 5 inches of rain have fallen today. The 
expected rainfall rate is 0.5 to 1 inch in 1 hour. Additional 
rainfall amounts up to 0.5 inches are possible in the warned area. 
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 may experience flash flooding include...
  Reading, Wyomissing, Hamburg, Sinking Spring, Laureldale, 
  Womelsdorf, Wernersville, Robesonia, Leesport, Shoemakersville, 
  Bernville, and Strausstown.

This includes the following highways...
	Pennsylvania Turnpike near mile marker 296.
	Interstate 78 in Pennsylvania between mile markers 14 and 37.
	Interstate 176 in Pennsylvania between mile markers 2 and 11.

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 4067 7590 4053 7585 4018 7590 4017 7593
      4031 7615 4036 7621 4041 7630 4052 7631
      4052 7626 4054 7617 4057 7608 4058 7607
      4057 7605 4058 7604 4057 7602 4064 7599

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL RATE...0.5-1 INCH IN 1 HOUR

$$

Staarmann

627 
WGUS71 KPHI 100243
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1043 PM EDT Sat Sep 9 2023

PAC011-100253-
/O.CAN.KPHI.FF.W.0082.000000T0000Z-230910T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
1043 PM EDT Sat Sep 9 2023

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

Flood waters are receding. The heavy rain has ended. Additional 
flooding is no longer expected to pose a threat.

LAT...LON 4067 7590 4053 7585 4018 7590 4017 7593
      4031 7615 4036 7621 4041 7630 4052 7631
      4052 7626 4054 7617 4057 7608 4058 7607
      4057 7605 4058 7604 4057 7602 4064 7599

$$

Iovino

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 9, 8:09 PM EDT	Areal Flood Advisory	PHI	Berks	20 min
Sep 9, 9:12 PM EDT	Areal Flood Advisory	PHI	Berks, Carbon, Lehigh, Monroe	116 min
Sep 10, 5:48 PM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery, Philadelphia	3 hr
Sep 10, 6:03 PM EDT	Flash Flood Warning	PHI	Bucks, Montgomery, Philadelphia	3 hr
Sep 10, 7:11 PM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Lehigh, Montgomery, Northampton	3 hr
Sep 10, 7:37 PM EDT	Areal Flood Advisory	PHI	Bucks	3 hr
Sep 10, 7:55 PM EDT	Flash Flood Warning	PHI	Bucks	3 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2023 Every flash flood warning in 2023

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.