Alert archive / Pennsylvania / Flash Flood Warnings in 2023

Flash Flood Warning 36, NWS Philadelphia/Mount Holly

July 9, 20234 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 9, 2023, 12:27 PM EDT for 4 counties in Pennsylvania. It was in force for 8 hr. 7 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, 12:27 PM EDT (16:27 UTC)
Expired: Jul 9, 2023, 8:30 PM EDT
In force: 8 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Berks County, PA, Bucks County, PA, Lehigh County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 103 km from the middle of the area, began a volume at 16:29 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, 12:36 PM EDT	FLASH FLOOD	Quakertown, PA	Report of several flooded roadways and water rescues by fire department in Quakertown. Time estimated via radar.
Jul 9, 1:43 PM EDT	FLOOD	1 W Quakertown, PA	Video of street flooding at the intersection of Main Street and California Road in Quakertown.
Jul 9, 2:44 PM EDT	FLASH FLOOD	Quakertown, PA	Water rescues reported via text and video on social media.
Jul 9, 4:28 PM EDT	FLOOD	1 W Quakertown, PA	Report of flooding at the shopping plazas at the intersection Rte 309 and Rte 313 in Quakertown.
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, 5:01 PM EDT	FLASH FLOOD	1 S Upper Hanover Twp, PA	The Perkiomen Creek at East Greenville reached minor flood stage.
Jul 9, 6:02 PM EDT	FLOOD	Trumbauersville, PA	Report of creek water over-spilling onto roadway at the intersection of Yankee Road and Allentown Road in Trumbauersville.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 4.5 hours before the alert went out and 219 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: 216 J/kg
Mixed-layer CIN: -64 J/kg
Mixed-layer LCL: 749 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 9 m²/s²
0-3 km storm-relative helicity: 32 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.2

Open this sounding in Storm Lab

The text

As transmitted.

562 
WGUS51 KPHI 091627
FFWPHI
PAC011-017-077-091-092230-
/O.NEW.KPHI.FF.W.0036.230709T1627Z-230709T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1227 PM EDT Sun Jul 9 2023

The National Weather Service in Mount Holly has issued a

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

* Until 630 PM EDT Sunday.

* At 1227 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. 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.

  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...
  Emmaus, Quakertown, East Greenville, Bally, Green Lane, Pleasant 
  Valley, Geryville, Zionsville, Pennsburg, Coopersburg, Red Hill, 
  and Richlandtown.

This includes the following highways...
	Northeast Extension between mile markers 38 and 51.

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 4038 7558 4038 7559 4045 7561 4055 7546
      4056 7537 4056 7536 4055 7536 4055 7535
      4054 7533 4055 7531 4055 7530 4055 7524
      4050 7524 4040 7530 4035 7538 4033 7542
      4034 7551

FLASH FLOOD...RADAR INDICATED

$$

Hoeflich

4 follow-up statements

764 
WGUS71 KPHI 091728
FFSPHI

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

PAC011-017-077-091-092230-
/O.CON.KPHI.FF.W.0036.000000T0000Z-230709T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Bucks PA-Lehigh PA-Montgomery PA-
128 PM EDT Sun Jul 9 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM EDT THIS 
EVENING FOR EAST CENTRAL BERKS, SOUTHEASTERN LEHIGH, NORTHWESTERN 
BUCKS, AND NORTH CENTRAL MONTGOMERY COUNTIES...

At 128 PM EDT, local law enforcement reported thunderstorms 
producing heavy rain. At 1:26 PM EDT, local law enforcement reported 
flooded roadways and water rescues around Quakertown. Between 2 and 
3 inches of rain have fallen. Additional rainfall amounts of 0.5 to 
1.5 inches are possible in the warned area. Flash flooding is 
already occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Law enforcement reported.

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...
  Emmaus, Quakertown, East Greenville, Bally, Green Lane, Pleasant 
  Valley, Geryville, Zionsville, Pennsburg, Coopersburg, Red Hill, 
  and Richlandtown.

This includes the following highways...
	Northeast Extension between mile markers 38 and 51.

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 4038 7558 4038 7559 4045 7561 4055 7546
      4056 7537 4056 7536 4055 7536 4055 7535
      4054 7533 4055 7531 4055 7530 4055 7524
      4050 7524 4040 7530 4035 7538 4033 7542
      4034 7551

FLASH FLOOD...OBSERVED

$$

Hoeflich

486 
WGUS71 KPHI 091958
FFSPHI

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

PAC011-017-077-091-092230-
/O.CON.KPHI.FF.W.0036.000000T0000Z-230709T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Bucks PA-Lehigh PA-Montgomery PA-
358 PM EDT Sun Jul 9 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM EDT THIS 
EVENING FOR EAST CENTRAL BERKS, SOUTHEASTERN LEHIGH, NORTHWESTERN 
BUCKS, AND NORTH CENTRAL MONTGOMERY COUNTIES...

At 358 PM EDT, local law enforcement reported thunderstorms 
producing heavy rain. At 2 PM EDT, local law enforcement reported 
flooded roadways and water rescues around Quakertown. With more rain 
about to move in, flash flooding is likely. Between 2.5 and 4 inches 
of rain have fallen. Additional rainfall amounts of 1 to 3 inches 
are possible in the warned area. Flash flooding is already occurring.

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

SOURCE...Law enforcement reported.

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

Some locations that may experience flash flooding include...
  Emmaus, Quakertown, East Greenville, Bally, Green Lane, Pleasant 
  Valley, Geryville, Zionsville, Pennsburg, Coopersburg, Red Hill, 
  and Richlandtown.

This includes the following highways...
	Northeast Extension between mile markers 38 and 51.

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 4038 7558 4038 7559 4045 7561 4055 7546
      4056 7537 4056 7536 4055 7536 4055 7535
      4054 7533 4055 7531 4055 7530 4055 7524
      4050 7524 4040 7530 4035 7538 4033 7542
      4034 7551

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

$$

Hoeflich

595 
WGUS51 KPHI 092212
FFWPHI
PAC011-017-077-091-100030-
/O.EXT.KPHI.FF.W.0036.000000T0000Z-230710T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Mount Holly has extended the

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

* Until 830 PM EDT.

* At 612 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 3 and 4 inches of rain 
  have fallen. 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.

  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...
  Emmaus, Quakertown, East Greenville, Bally, Green Lane, Pleasant 
  Valley, Geryville, Zionsville, Pennsburg, Coopersburg, Red Hill, 
  and Richlandtown.

This includes the following highways...
	Northeast Extension between mile markers 38 and 51.

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 4038 7558 4038 7559 4045 7561 4055 7546
      4056 7537 4056 7536 4055 7536 4055 7535
      4054 7533 4055 7531 4055 7530 4055 7524
      4050 7524 4040 7530 4035 7538 4033 7542
      4034 7551

FLASH FLOOD...RADAR INDICATED

$$

Hoeflich

802 
WGUS71 KPHI 100020 RRA
FFSPHI

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

PAC011-017-077-091-100030-
/O.EXP.KPHI.FF.W.0036.000000T0000Z-230710T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Bucks PA-Lehigh PA-Montgomery PA-
820 PM EDT Sun Jul 9 2023

...FLASH FLOOD WARNING WILL EXPIRE AT 830 PM EDT THIS EVENING FOR 
EAST CENTRAL BERKS, SOUTHEASTERN LEHIGH, NORTHWESTERN BUCKS, AND 
NORTH CENTRAL MONTGOMERY COUNTIES...

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat.

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

LAT...LON 4038 7558 4038 7559 4045 7561 4055 7546
      4056 7537 4056 7536 4055 7536 4055 7535
      4054 7533 4055 7531 4055 7530 4055 7524
      4050 7524 4040 7530 4035 7538 4033 7542
      4034 7551

$$

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, 12:37 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, 3:51 PM EDT	Flash Flood Warning Considerable damage threat	PHI	Berks, Chester, Lehigh, Montgomery	6 hr
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.