Alert archive / Pennsylvania / Flash Flood Warnings in 2023

Flash Flood Warning 57, NWS Philadelphia/Mount Holly

July 16, 20234 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 16, 2023, 2:43 AM EDT for 4 counties in Pennsylvania. It was in force for 4 hr. 2 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 16, 2023, 2:43 AM EDT (06:43 UTC)
Expired: Jul 16, 2023, 6:45 AM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Carbon County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA

The radar

The Binghamton radar (KBGM), 145 km from the middle of the area, began a volume at 06:45 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 16, 5:00 AM EDT	FLASH FLOOD	Palmer Heights, PA	Report of a water rescue at the intersection of Mine Land Road and Division Street. Time estimated.
Jul 16, 6:25 AM EDT	FLASH FLOOD	Washington Twp, PA	Report of basement wall collapsed with water up to the first story and rising. Time estimated.

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 00:00Z, 6.7 hours before the alert went out and 234 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: 1061 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 624 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 63 m²/s²
0-3 km storm-relative helicity: 29 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 2.0

Open this sounding in Storm Lab

The text

As transmitted.

839 
WGUS51 KPHI 160643
FFWPHI
PAC025-077-089-095-161045-
/O.NEW.KPHI.FF.W.0057.230716T0643Z-230716T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
243 AM EDT Sun Jul 16 2023

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Lehigh County in eastern Pennsylvania...
  Northampton County in eastern Pennsylvania...
  Carbon County in northeastern Pennsylvania...
  Monroe County in northeastern Pennsylvania...

* Until 645 AM EDT.

* At 243 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1 inch of rain 
  has fallen. The expected rainfall rate is 0.5 to 1 inch in 1 hour. 
  Additional rainfall amounts of 0.5 to 1 inch 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...
  Allentown, Easton, Lehighton, Mount Pocono, Bethlehem, Emmaus, 
  Northampton, East Stroudsburg, Tobyhanna, Wilson, Hellertown, and 
  Nazareth.

This includes the following highways...
	Interstate 78 in Pennsylvania between mile markers 46 and 73.
	Interstate 80 in Pennsylvania between mile markers 277 and 311.
	Interstate 380 in Pennsylvania between mile markers 0 and 12.
	Northeast Extension between mile markers 48 and 97.

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 4093 7592 4101 7573 4105 7577 4109 7577
      4113 7569 4112 7563 4122 7554 4125 7513
      4064 7525 4046 7550 4057 7571 4073 7578
      4074 7576

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

$$

SFJ

3 follow-up statements

846 
WGUS71 KPHI 160802
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
402 AM EDT Sun Jul 16 2023

PAC025-077-089-095-161045-
/O.CON.KPHI.FF.W.0057.000000T0000Z-230716T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Carbon PA-Lehigh PA-Monroe PA-Northampton PA-
402 AM EDT Sun Jul 16 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 AM EDT THIS 
MORNING FOR LEHIGH, NORTHAMPTON, EASTERN CARBON, AND MONROE 
COUNTIES...

At 402 AM 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. Although an initial band of 
thunderstorms has left the warned area, another cluster of 
thunderstorms is approaching the area. The expected rainfall rate is 
0.25 to 0.5 inches in 1 hour. Additional rainfall amounts of 0.5 to 
1 inch 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...
  Allentown, Easton, Lehighton, Mount Pocono, Bethlehem, Emmaus, 
  Northampton, East Stroudsburg, Tobyhanna, Wilson, Hellertown, and 
  Nazareth.

This includes the following highways...
	Interstate 78 in Pennsylvania between mile markers 46 and 73.
	Interstate 80 in Pennsylvania between mile markers 283 and 311.
	Interstate 380 in Pennsylvania between mile markers 0 and 12.
	Northeast Extension between mile markers 48 and 93.

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 4074 7576 4101 7573 4122 7554 4125 7513
      4064 7525 4046 7550 4057 7571

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL RATE...0.25-0.5 INCHES IN 1 HOUR

$$

SFJ

882 
WGUS71 KPHI 160830
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
430 AM EDT Sun Jul 16 2023

PAC025-160840-
/O.CAN.KPHI.FF.W.0057.000000T0000Z-230716T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Carbon PA-
430 AM EDT Sun Jul 16 2023

...FLASH FLOOD WARNING IS CANCELLED FOR EASTERN CARBON COUNTY...

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

A Flood Watch remains in effect until 1200 AM EDT Monday for 
portions of northern Delaware...New Jersey...and Pennsylvania.

LAT...LON 4100 7519 4064 7525 4057 7539 4049 7555
      4057 7571

$$

PAC077-089-095-161045-
/O.CON.KPHI.FF.W.0057.000000T0000Z-230716T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lehigh PA-Monroe PA-Northampton PA-
430 AM EDT Sun Jul 16 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 AM EDT THIS 
MORNING FOR CENTRAL LEHIGH, CENTRAL NORTHAMPTON, AND SOUTH CENTRAL 
MONROE COUNTIES...

At 430 AM EDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 
1.5 and 3 inches of rain have fallen. The expected rainfall rate is 
0.5 to 1 inch in 1 hour. Additional rainfall amounts of 0.5 to 1 
inch 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 and automated gauges.

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

Some locations that may experience flash flooding include...
  Allentown, Easton, Bethlehem, Emmaus, Northampton, East 
  Stroudsburg, Wilson, Hellertown, Nazareth, Bangor, Pen Argyl, and 
  Wind Gap.

This includes the following highways...
	Interstate 78 in Pennsylvania between mile markers 47 and 67...and
	between mile markers 72 and 73.
	Interstate 80 in Pennsylvania between mile markers 310 and 311.
	Northeast Extension between mile markers 51 and 62.

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 4100 7519 4064 7525 4057 7539 4049 7555
      4057 7571

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

$$

SFJ

857 
WGUS71 KPHI 161041
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
641 AM EDT Sun Jul 16 2023

PAC077-089-095-161051-
/O.EXP.KPHI.FF.W.0057.000000T0000Z-230716T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lehigh PA-Monroe PA-Northampton PA-
641 AM EDT Sun Jul 16 2023

...FLASH FLOOD WARNING WILL EXPIRE AT 645 AM EDT THIS MORNING FOR 
CENTRAL LEHIGH, CENTRAL NORTHAMPTON, AND SOUTH CENTRAL MONROE 
COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. However, it may take time for water to recede in some areas. 
Please continue to heed any road closures.

A Flood Watch remains in effect until 1200 AM EDT Monday for 
portions of northern Delaware...New Jersey...and Pennsylvania.

LAT...LON 4100 7519 4064 7525 4057 7539 4049 7555
      4057 7571

$$

SFJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 15, 8:37 PM EDT	Areal Flood Advisory	PHI	Carbon	19 min
Jul 15, 8:44 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	30 min
Jul 15, 8:56 PM EDT	Flash Flood Warning	PHI	Carbon	95 min
Jul 16, 12:50 AM EDT	Special Weather Statement	PHI	Berks	25 min
Jul 16, 1:41 AM EDT	Special Weather Statement	PHI	Carbon, Lehigh	34 min
Jul 16, 2:12 AM EDT	Special Weather Statement	PHI	Carbon, Lehigh, Monroe	33 min
Jul 16, 2:47 AM EDT	Special Weather Statement	PHI	Chester, Delaware	28 min
Jul 16, 3:40 AM EDT	Flash Flood Warning	PHI	Monroe, Northampton	7 hr
Jul 16, 4:05 AM EDT	Flash Flood Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery, Northampton	6 hr
Jul 16, 4:14 AM EDT	Special Weather Statement	PHI	Bucks	31 min
Jul 16, 4:38 AM EDT	Tornado Warning	PHI	Bucks	37 min
Jul 16, 9:12 AM EDT	Flash Flood Warning	PHI	Chester	2 hr
Jul 16, 9:40 AM EDT	Flash Flood Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	3 hr
Jul 16, 9:53 AM EDT	Tornado Warning	PHI	Montgomery, Philadelphia	37 min
Jul 16, 10:54 AM EDT	Areal Flood Warning	PHI	Monroe, Northampton	5 hr
Jul 16, 11:08 AM EDT	Flash Flood Warning	PHI	Delaware, Philadelphia	3 hr
Jul 16, 12:22 PM EDT	Areal Flood Advisory	PHI	Bucks, Philadelphia	3 hr
Jul 16, 12:26 PM EDT	Areal Flood Advisory	PHI	Philadelphia	3 hr
Jul 16, 1:47 PM EDT	Areal Flood Advisory	PHI	Delaware, Philadelphia	80 min
Jul 16, 6:44 PM EDT	Areal Flood Advisory	PHI	Bucks	90 min

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.