Alert archive / Pennsylvania / Flash Flood Warnings in 2023

Flash Flood Warning 44, NWS Philadelphia/Mount Holly

July 9, 20234 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 9, 2023, 3:51 PM EDT for 4 counties in Pennsylvania. It was in force for 6 hr. 4 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 9, 2023, 3:51 PM EDT (19:51 UTC)
Expired: Jul 9, 2023, 9:45 PM EDT
In force: 6 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Berks County, PA, Chester County, PA, Lehigh County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 118 km from the middle of the area, began a volume at 19:53 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
Jul 9, 4:20 PM EDT	FLASH FLOOD	1 Sse Boyertown, PA	Trained spotter reports a water rescue at the intersection of Swinehart Rd and Jackson Rd in Douglass Twp due to ongoing flooding.
Jul 9, 4:43 PM EDT	FLOOD	2 W Upper Hanover Twp, PA	Kutztown Road nearly impassable due to flooding between Peevy & Schwenkenfelder Roads near Fruitville, PA.
Jul 9, 7:15 PM EDT	FLASH FLOOD	3 Sw Earl Twp, PA	The Manatawny Creek gauge at Spangville reached minor flood stage. It reached moderate flood stage at 7:45 PM.
Jul 9, 8:17 PM EDT	FLASH FLOOD	Oley Furnace, PA	Photo of Reider Road Bridge in Oley has significant damage with road buckling due to creek flooding underneath.

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, 7.9 hours before the alert went out and 210 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: 952 J/kg
Mixed-layer CIN: -58 J/kg
Mixed-layer LCL: 686 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 12 m²/s²
0-3 km storm-relative helicity: 37 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

111 
WGUS51 KPHI 091951
FFWPHI
PAC011-029-077-091-100145-
/O.NEW.KPHI.FF.W.0044.230709T1951Z-230710T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
351 PM EDT Sun Jul 9 2023

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Southeastern Berks County in eastern Pennsylvania...
  Southeastern Lehigh County in eastern Pennsylvania...
  North Central Chester County in southeastern Pennsylvania...
  Northwestern Montgomery County in southeastern Pennsylvania...

* Until 945 PM EDT.

* At 351 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1.5 inches of 
  rain have fallen. Additional rainfall amounts of 1 to 3 inches are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Life threatening flash flooding caused by
           thunderstorms.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets, and underpasses.

* Some locations that may experience flash flooding include...
  Allentown, Pottstown, Emmaus, Birdsboro, Topton, Elverson, Bally, 
  Bechtelsville, Lyons, New Morgan, Gilbertsville, and Cedarville.

This includes the following highways...
	Pennsylvania Turnpike between mile markers 296 and 305.
	Interstate 78 in Pennsylvania between mile markers 57 and 62.
	Interstate 176 in Pennsylvania between mile markers 1 and 6.
	Northeast Extension between mile markers 49 and 54.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4021 7599 4024 7592 4052 7575 4057 7551
      4057 7541 4054 7545 4038 7553 4035 7553
      4020 7559 4010 7579 4014 7588 4014 7587

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Hoeflich

2 follow-up statements

887 
WGUS71 KPHI 092043
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
443 PM EDT Sun Jul 9 2023

PAC011-029-077-091-100145-
/O.CON.KPHI.FF.W.0044.000000T0000Z-230710T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Chester PA-Lehigh PA-Montgomery PA-
443 PM EDT Sun Jul 9 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 945 PM EDT THIS 
EVENING FOR SOUTHEASTERN BERKS, SOUTHEASTERN LEHIGH, NORTH CENTRAL 
CHESTER, AND NORTHWESTERN MONTGOMERY COUNTIES...

At 443 PM EDT, trained weather spotters reported thunderstorms 
producing heavy rain. At 4:20 PM, a trained spotter reported a water 
rescue in Douglass Township, PA. Between 1.5 and 2.5 inches of rain 
have fallen. Additional rainfall amounts of 1 to 2 inches are 
possible in the warned area. Flash flooding is already occurring.

HAZARD...Life threatening flash flooding caused by thunderstorms.

SOURCE...Trained spotters reported.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets, and underpasses.

Some locations that may experience flash flooding include...
  Allentown, Pottstown, Emmaus, Birdsboro, Topton, Elverson, Bally, 
  Bechtelsville, Lyons, New Morgan, Gilbertsville, and Cedarville.

This includes the following highways...
	Pennsylvania Turnpike between mile markers 296 and 305.
	Interstate 78 in Pennsylvania between mile markers 57 and 61.
	Interstate 176 in Pennsylvania between mile markers 1 and 7.
	Northeast Extension between mile markers 49 and 54.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4021 7599 4024 7592 4052 7575 4057 7551
      4057 7541 4054 7545 4038 7553 4035 7553
      4020 7559 4010 7579 4014 7588 4014 7587

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Hoeflich

772 
WGUS71 KPHI 100136
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
936 PM EDT Sun Jul 9 2023

PAC011-029-077-091-100146-
/O.EXP.KPHI.FF.W.0044.000000T0000Z-230710T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Chester PA-Lehigh PA-Montgomery PA-
936 PM EDT Sun Jul 9 2023

...FLASH FLOOD WARNING WILL EXPIRE AT 945 PM EDT THIS EVENING FOR 
SOUTHEASTERN BERKS, SOUTHEASTERN LEHIGH, NORTH CENTRAL CHESTER, AND 
NORTHWESTERN MONTGOMERY COUNTIES...

The heavy rain has ended. Part of the area in the warning remains in 
an Areal Flood Warning. Please refer to that bulletin for the 
updated information.

A Flood Watch remains in effect until 1200 AM EDT for portions of 
east central Pennsylvania...northeast Pennsylvania...and southeast 
Pennsylvania.

LAT...LON 4021 7599 4024 7592 4052 7575 4057 7551
      4057 7541 4054 7545 4038 7553 4035 7553
      4020 7559 4010 7579 4014 7588 4014 7587

$$

Hoeflich

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 11:00 AM EDT	Special Weather Statement	PHI	Carbon	30 min
Jul 9, 11:33 AM EDT	Flash Flood Warning	PHI	Chester, Delaware, Montgomery	8 hr
Jul 9, 11:47 AM EDT	Special Weather Statement	PHI	Monroe	43 min
Jul 9, 11:49 AM EDT	Special Weather Statement	PHI	Montgomery	41 min
Jul 9, 11:54 AM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Lehigh, Montgomery	33 min
Jul 9, 12:14 PM EDT	Special Weather Statement	PHI	Bucks	46 min
Jul 9, 12:15 PM EDT	Special Weather Statement	PHI	Monroe	30 min
Jul 9, 12:22 PM EDT	Special Weather Statement	PHI	Lebanon	38 min
Jul 9, 12:27 PM EDT	Flash Flood Warning	PHI	Berks, Bucks, Lehigh, Montgomery	8 hr
Jul 9, 12:37 PM EDT	Areal Flood Advisory	PHI	Bucks, Lehigh, Northampton	2 hr
Jul 9, 12:43 PM EDT	Areal Flood Advisory	PHI	Berks	33 min
Jul 9, 12:51 PM EDT	Special Weather Statement	PHI	Northampton	24 min
Jul 9, 12:57 PM EDT	Areal Flood Advisory	PHI	Carbon, Monroe	6 hr
Jul 9, 1:02 PM EDT	Flash Flood Warning	PHI	Bucks, Lehigh, Northampton	8 hr
Jul 9, 1:16 PM EDT	Flash Flood Warning	PHI	Berks	6 hr
Jul 9, 1:17 PM EDT	Special Weather Statement	PHI	Berks	28 min
Jul 9, 1:32 PM EDT	Areal Flood Advisory	PHI	Carbon, Lehigh, Monroe, Northampton	4 hr
Jul 9, 2:16 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	30 min
Jul 9, 2:41 PM EDT	Flash Flood Warning	PHI	Berks	4 hr
Jul 9, 2:46 PM EDT	Flash Flood Warning	PHI	Berks, Lehigh, Northampton	6 hr
Jul 9, 3:01 PM EDT	Special Weather Statement	PHI	Berks	29 min
Jul 9, 3:03 PM EDT	Special Weather Statement	PHI	Chester	27 min
Jul 9, 3:15 PM EDT	Severe Thunderstorm Warning	PHI	Berks	30 min
Jul 9, 3:20 PM EDT	Special Weather Statement	PHI	Berks	25 min
Jul 9, 3:27 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester	33 min
Jul 9, 3:41 PM EDT	Special Weather Statement	PHI	Berks	34 min
Jul 9, 3:59 PM EDT	Special Weather Statement	PHI	Chester	31 min
Jul 9, 4:03 PM EDT	Severe Thunderstorm Warning	PHI	Montgomery	27 min
Jul 9, 4:19 PM EDT	Special Weather Statement	PHI	Chester	26 min
Jul 9, 4:31 PM EDT	Flash Flood Warning	PHI	Chester, Montgomery	4 hr
Jul 9, 5:10 PM EDT	Severe Thunderstorm Warning	PHI	Delaware	50 min
Jul 9, 5:12 PM EDT	Flash Flood Warning	PHI	Bucks, Montgomery	5 hr
Jul 9, 5:15 PM EDT	Special Weather Statement	PHI	Bucks, Delaware, Philadelphia	30 min
Jul 9, 5:31 PM EDT	Flash Flood Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	4 hr
Jul 9, 5:35 PM EDT	Severe Thunderstorm Warning	PHI	Philadelphia	25 min
Jul 9, 5:59 PM EDT	Flash Flood Warning	PHI	Bucks, Montgomery	4 hr
Jul 9, 6:05 PM EDT	Special Weather Statement	PHI	Bucks	25 min
Jul 9, 7:04 PM EDT	Areal Flood Warning	PHI	Berks	9 hr
Jul 9, 7:11 PM EDT	Areal Flood Advisory	PHI	Bucks	3 hr
Jul 9, 7:27 PM EDT	River Flood Warning	PHI	Chester	4 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.