Alert archive / Pennsylvania / Flash Flood Warnings in 2020

Flash Flood Warning 38, NWS Philadelphia/Mount Holly

August 4, 2020Monroe County, Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 4, 2020, 9:38 AM EDT for Monroe County, Northampton County, Pennsylvania. It was in force for 4 hr. 13 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
Aug 4, 2020, 9:38 AM EDT (13:38 UTC)
Expired
Aug 4, 2020, 1:30 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Monroe County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 119 km from the middle of the area, began a volume at 13:42 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

TimeReportWhereRemark
Aug 4, 12:06 PM EDTFLASH FLOOD2 Sse Tatamy, PAFLOODING ON ZUCKSVILLE ROAD NEAR BUSHKILL DRIVE. TIME BASED ON DISPATCH REPORT.
Aug 4, 12:11 PM EDTFLASH FLOOD1 E Nazareth, PAFLOODING ON TATAMY ROAD NEAR FRIENDENSTHAL AVENUE. TIME BASED ON DISPATCH REPORT.
Aug 4, 12:15 PM EDTHEAVY RAIN 2.11 N Pocono Summit, PAASOS STATION KMPO MT. POCONO.
Aug 4, 12:21 PM EDTFLASH FLOOD2 Ene Bethlehem Twp, PAFLASH FLOODING CLOSED FARMERSVILLE ROAD NEAR EASTON AVENUE. TIME BASED ON DISPATCH REPORT.
Aug 4, 12:30 PM EDTFLASH FLOODEaston, PAFLOODING AT BLUE RESTAURANT IN EASTON PA, WITH NUMEROUS ROADS IN THE AREA FLOODED. RAIN TOTALS NEAR 6-7INCHES.
Aug 4, 12:36 PM EDTHEAVY RAIN 3.862 Nne Sciota, PAMESONET STATION DW4714 SNYDERSVILLE.
Aug 4, 12:40 PM EDTHEAVY RAIN 2.682 Nne Long Pond, PAMESONET STATION EW6499 POCONO PINES.
Aug 4, 12:40 PM EDTHEAVY RAIN 5.361 Ene Saylorsburg, PAMESONET STATION DW3072 SAYLORSBURG.
Aug 4, 12:50 PM EDTHEAVY RAIN 2.851 Ssw Skytop, PAMESONET STATION 7260D SKYTOP.
Aug 4, 1:00 PM EDTFLASH FLOOD1 Nne Bossardsville, PAFLASH FLOODING CLOSED CHERRY VALLEY ROAD NEAR GOODALE ROAD. TIME BASED ON A COMBINATION OF SOCIAL MEDIA AND DISPATCH REPORTS.
Aug 4, 1:17 PM EDTHEAVY RAIN 5.2Arlington Heights, PA5.2 INCHES OF RAIN SO FAR.
Aug 4, 1:30 PM EDTFLASH FLOOD1 Nnw Sciota, PAFLASH FLOODING ON APPENZELL CREEK DAMAGED A PORT OF PENNSYLVANIA CREEK ROAD. TIME ESTIMATED BASED ON DISPATCH REPORTS.
Aug 4, 1:39 PM EDTFLASH FLOOD2 Nw Bath, PAFLOODING CLOSED GROUSE DRIVE NEAR WHITETAIL DEER DRIVE. TIME BASED ON DISPATCH REPORT.

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, 1.6 hours before the alert went out and 202 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-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 2020-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1593 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2020-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 150 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
1593 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
570 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
150 m²/s²
0-3 km storm-relative helicity
245 m²/s²
Significant tornado parameter
1.5
Supercell composite
7.4

Open this sounding in Storm Lab

The text

As transmitted.

585 
WGUS51 KPHI 041338
FFWPHI
PAC089-095-041730-
/O.NEW.KPHI.FF.W.0038.200804T1338Z-200804T1730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
938 AM EDT Tue Aug 4 2020

The National Weather Service in Mount Holly NJ has issued a

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

* Until 130 PM EDT.

* At 935 AM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to three inches of rain have
  already fallen. Flash flooding is ongoing or expected to begin
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  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 could experience flooding include...
  Easton, Mount Pocono, Bethlehem, Forks, Tobyhanna, Wilson,
  Nazareth, Bangor, Pen Argyl, Wind Gap, Bath, Belfast, West Easton,
  Tatamy, East Bangor, Steuben, Glendon, Stormville, Pocono Pines and
  Skytop.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 4072 7518 4070 7520 4068 7520 4067 7518
      4065 7520 4065 7541 4067 7543 4123 7548
      4125 7522

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...2-3 INCHES IN 1 HOUR

$$

Kruzdlo
1 follow-up statement
528 
WGUS71 KPHI 041728
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
128 PM EDT Tue Aug 4 2020

PAC089-095-041734-
/O.EXP.KPHI.FF.W.0038.000000T0000Z-200804T1730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Monroe PA-Northampton PA-
128 PM EDT Tue Aug 4 2020

...THE FLASH FLOOD WARNING FOR CENTRAL MONROE AND CENTRAL NORTHAMPTON
COUNTIES WILL EXPIRE AT 130 PM EDT...

This Flash Flood Warning will be allowed to expire. Southern 
portions of this warning have been replaced by another Flash Flood 
Warning. The northern portion has been replaced by a Flood Advisory.

LAT...LON 4072 7518 4070 7520 4068 7520 4067 7518
      4065 7520 4065 7541 4067 7543 4123 7548
      4125 7522

$$

Kruzdlo

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 5:17 AM EDTAreal Flood AdvisoryPHIBucks, Chester, Delaware, Montgomery, Philadelphia4 hr
Aug 4, 7:23 AM EDTTornado WarningPHIChester, Delaware, Montgomery, Philadelphia20 min
Aug 4, 7:28 AM EDTFlash Flood WarningPHIChester, Delaware, Montgomery3 hr
Aug 4, 8:11 AM EDTFlash Flood WarningPHIBucks, Lehigh, Montgomery, Northampton4 hr
Aug 4, 8:19 AM EDTRiver Flood WarningPHIDelaware15 hr
Aug 4, 8:19 AM EDTTornado WarningPHIBucks26 min
Aug 4, 9:23 AM EDTTornado Warning Tornado observedPHIChester22 min
Aug 4, 9:29 AM EDTTornado WarningPHIMonroe, Northampton31 min
Aug 4, 9:58 AM EDTTornado WarningPHIMonroe16 min
Aug 4, 10:02 AM EDTFlash Flood WarningPHIChester, Delaware4 hr
Aug 4, 10:20 AM EDTFlash Flood WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia4 hr
Aug 4, 10:51 AM EDTTornado WarningPHIMontgomery24 min
Aug 4, 11:01 AM EDTFlash Flood WarningPHIBucks4 hr
Aug 4, 11:13 AM EDTAreal Flood AdvisoryPHIBerks, Carbon, Lehigh, Monroe, Northampton4 hr
Aug 4, 11:43 AM EDTFlash Flood WarningPHIBerks, Lehigh, Northampton4 hr
Aug 4, 12:06 PM EDTRiver Flood WarningPHIChester11 hr
Aug 4, 12:37 PM EDTRiver Flood WarningPHIMontgomery14 hr
Aug 4, 12:48 PM EDTRiver Flood WarningPHIChester, Delaware24 hr
Aug 4, 1:01 PM EDTRiver Flood WarningPHIBucks18 hr
Aug 4, 1:12 PM EDTRiver Flood WarningPHIBerks10 hr
Aug 4, 1:12 PM EDTRiver Flood WarningPHIMontgomery26 hr
Aug 4, 1:12 PM EDTRiver Flood WarningPHIChester, Montgomery, Philadelphia43 hr
Aug 4, 1:12 PM EDTRiver Flood WarningPHIMontgomery, Philadelphia35 hr
Aug 4, 1:59 PM EDTAreal Flood WarningPHIChester, Delaware9 hr
Aug 4, 2:09 PM EDTAreal Flood WarningPHIBerks, Chester, Delaware, Montgomery, Philadelphia15 hr
Aug 4, 2:23 PM EDTRiver Flood WarningPHILehigh16 hr
Aug 4, 2:47 PM EDTAreal Flood WarningPHIBucks9 hr
Aug 4, 3:42 PM EDTAreal Flood WarningPHILehigh, Northampton4 hr
Aug 4, 4:39 PM EDTRiver Flood WarningPHIMonroe6 hr
Aug 4, 7:29 PM EDTAreal Flood WarningPHILehigh, Northampton12 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2020Every flash flood warning in 2020

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.