Alert archive / Pennsylvania / Flash Flood Warnings in 2019

Flash Flood Warning 53, NWS Philadelphia/Mount Holly

July 17, 2019Bucks County, Lehigh County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 17, 2019, 7:36 PM EDT for Bucks County, Lehigh County, Montgomery County, Pennsylvania. It was in force for 3 hr. 1 report 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 17, 2019, 7:36 PM EDT (23:36 UTC)
Expired: Jul 17, 2019, 10:30 PM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

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

The radar

The Philadelphia radar (KDIX), 112 km from the middle of the area, began a volume at 23:35 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 17, 8:00 PM EDT	HEAVY RAIN 1.2	Gilbertsville, PA	FELL IN 30 MINUTES.

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, 11.6 hours before the alert went out and 223 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: 1986 J/kg
Mixed-layer CIN: -43 J/kg
Mixed-layer LCL: 865 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 157 m²/s²
0-3 km storm-relative helicity: 170 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.2

Open this sounding in Storm Lab

The text

As transmitted.

638 
WGUS51 KPHI 172336
FFWPHI
PAC017-077-091-180230-
/O.NEW.KPHI.FF.W.0053.190717T2336Z-190718T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
736 PM EDT Wed Jul 17 2019

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Northwestern Montgomery County in southeastern Pennsylvania...
  Lehigh County in eastern Pennsylvania...
  Northwestern Bucks County in southeastern Pennsylvania...

* Until 1030 PM EDT.

* At 734 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain moving from west to east into the area.  Rainfall rates 
  between one and two inches per hour have been reported where the 
  rain is already falling, and flash flooding has been reported.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4077 7561 4072 7556 4073 7553 4066 7548
      4067 7543 4062 7538 4058 7541 4054 7533
      4060 7521 4057 7518 4056 7513 4013 7549
      4024 7560 4022 7561 4024 7569 4045 7553
      4061 7577

$$

JJM

2 follow-up statements

582 
WGUS71 KPHI 180116
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
916 PM EDT Wed Jul 17 2019

PAC017-091-180123-
/O.CAN.KPHI.FF.W.0053.000000T0000Z-190718T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery PA-Bucks PA-
916 PM EDT Wed Jul 17 2019

...THE FLASH FLOOD WARNING FOR NORTHWESTERN MONTGOMERY AND
NORTHWESTERN BUCKS COUNTIES IS CANCELLED...

Heavy rain has moved out of the area. Mainly light rain now falling 
across the area should have little adverse effect, so the flash 
flood warning has been cancelled.  Please continue to heed any 
remaining road closures.

LAT...LON 4077 7561 4072 7556 4073 7553 4066 7548
      4067 7543 4062 7538 4049 7559 4061 7577

$$

PAC077-180230-
/O.CON.KPHI.FF.W.0053.000000T0000Z-190718T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lehigh PA-
916 PM EDT Wed Jul 17 2019

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1030 PM EDT FOR
CENTRAL LEHIGH COUNTY...

Some small feeder streams are still running high from earlier rain. 
The flash flood warning will therefore continue to give the needed 
time for these streams to drain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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


&&

LAT...LON 4077 7561 4072 7556 4073 7553 4066 7548
      4067 7543 4062 7538 4049 7559 4061 7577

$$
JJM

117 
WGUS71 KPHI 180223
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1023 PM EDT Wed Jul 17 2019

PAC077-180232-
/O.EXP.KPHI.FF.W.0053.000000T0000Z-190718T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lehigh PA-
1023 PM EDT Wed Jul 17 2019

...THE FLASH FLOOD WARNING FOR CENTRAL LEHIGH COUNTY WILL EXPIRE AT
1030 PM EDT...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 4077 7561 4072 7556 4073 7553 4066 7548
      4067 7543 4062 7538 4049 7559 4061 7577

$$

SFJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 16, 9:15 PM EDT	Special Weather Statement	PHI	Philadelphia	45 min
Jul 17, 3:54 AM EDT	Flash Flood Watch	PHI	Berks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more	19 hr
Jul 17, 1:26 PM EDT	Special Weather Statement	PHI	Pike	34 min
Jul 17, 1:50 PM EDT	Areal Flood Advisory	PHI	Carbon, Lehigh, Monroe, Northampton	80 min
Jul 17, 2:05 PM EDT	Special Weather Statement	PHI	Lehigh	25 min
Jul 17, 3:14 PM EDT	Excessive Heat Watch	PHI	Berks, Bucks, Carbon, Chester, Lehigh, Monroe and 2 more	24 hr
Jul 17, 5:05 PM EDT	Special Weather Statement	PHI	Carbon, Monroe	40 min
Jul 17, 5:14 PM EDT	Special Weather Statement	PHI	Lehigh	46 min
Jul 17, 5:44 PM EDT	Special Weather Statement	PHI	Monroe	46 min
Jul 17, 5:46 PM EDT	Areal Flood Advisory	PHI	Monroe	119 min
Jul 17, 5:49 PM EDT	Special Weather Statement	PHI	Lehigh, Northampton	41 min
Jul 17, 6:24 PM EDT	Special Weather Statement	PHI	Berks	51 min
Jul 17, 6:35 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	40 min
Jul 17, 6:51 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	54 min
Jul 17, 6:52 PM EDT	Areal Flood Advisory	PHI	Berks	113 min
Jul 17, 7:06 PM EDT	Flash Flood Warning	PHI	Berks	3 hr
Jul 17, 7:15 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery	45 min
Jul 17, 7:21 PM EDT	Flash Flood Warning	PHI	Chester	97 min
Jul 17, 7:31 PM EDT	Special Weather Statement	PHI	Lehigh, Northampton	44 min
Jul 17, 7:44 PM EDT	Special Weather Statement	PHI	Lehigh	31 min
Jul 17, 7:56 PM EDT	Special Weather Statement	PHI	Bucks, Montgomery, Philadelphia	64 min

Nearby

Flash Flood Warnings in Pennsylvania, 2019 Every flash flood warning in 2019

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.