Alert archive / Pennsylvania / Flash Flood Warnings in 2018

Flash Flood Warning 18, NWS Philadelphia/Mount Holly

July 3, 2018Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 3, 2018, 3:11 PM EDT for Montgomery County, Philadelphia County, Pennsylvania. It was in force for 50 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 3, 2018, 3:11 PM EDT (19:11 UTC)
Expired: Jul 3, 2018, 4:01 PM EDT
In force: 50 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Montgomery County, PA, Philadelphia County, PA

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 7.2 hours before the alert went out and 211 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: 864 J/kg
Mixed-layer CIN: -149 J/kg
Mixed-layer LCL: 920 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 35 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

381 
WGUS51 KPHI 031911
FFWPHI
PAC091-101-032315-
/O.NEW.KPHI.FF.W.0018.180703T1911Z-180703T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
311 PM EDT TUE JUL 3 2018

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Eastern Montgomery County in southeastern Pennsylvania...
  Central Philadelphia County in southeastern Pennsylvania...

* Until 715 PM EDT.

* At 310 PM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Flash flooding is expected to
  begin shortly in the areas of heaviest rain.

* Some locations that could experience flooding include...
  Philadelphia.

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 4004 7507 4001 7513 4007 7518 4009 7511

$$

Meola

1 follow-up statement

008 
WGUS71 KPHI 032001
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
401 PM EDT TUE JUL 3 2018

PAC091-101-032010-
/O.CAN.KPHI.FF.W.0018.000000T0000Z-180703T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery PA-Philadelphia PA-
401 PM EDT TUE JUL 3 2018

...THE FLASH FLOOD WARNING FOR EASTERN MONTGOMERY AND CENTRAL
PHILADELPHIA COUNTIES IS CANCELLED...

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

LAT...LON 4004 7507 4001 7513 4007 7518 4009 7511

$$

Meola

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 3, 2:15 PM EDT	Special Weather Statement	PHI	Delaware	30 min
Jul 3, 3:00 PM EDT	Special Weather Statement	PHI	Philadelphia	60 min
Jul 3, 4:06 PM EDT	Special Weather Statement	PHI	Montgomery	54 min
Jul 3, 4:30 PM EDT	Special Weather Statement	PHI	Bucks	60 min
Jul 3, 5:24 PM EDT	Areal Flood Advisory	PHI	Delaware, Montgomery, Philadelphia	4 hr
Jul 3, 5:29 PM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery, Philadelphia	4 hr
Jul 3, 5:30 PM EDT	Special Weather Statement	PHI	Philadelphia	30 min
Jul 3, 5:45 PM EDT	Flash Flood Warning	PHI	Delaware, Montgomery, Philadelphia	4 hr
Jul 3, 6:03 PM EDT	Special Weather Statement	PHI	Monroe	57 min
Jul 3, 6:15 PM EDT	Special Weather Statement	PHI	Chester	60 min
Jul 3, 6:18 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	42 min
Jul 3, 6:21 PM EDT	Special Weather Statement	PHI	Delaware	24 min
Jul 3, 6:25 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Philadelphia	50 min
Jul 3, 6:37 PM EDT	Flash Flood Warning	PHI	Bucks, Philadelphia	3 hr
Jul 3, 6:40 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware	4 hr
Jul 3, 6:50 PM EDT	Special Weather Statement	PHI	Delaware	55 min
Jul 3, 6:54 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	51 min
Jul 3, 6:58 PM EDT	Flash Flood Warning	PHI	Chester, Delaware	4 hr
Jul 3, 7:03 PM EDT	Special Weather Statement	PHI	Northampton	57 min
Jul 3, 7:06 PM EDT	Flash Flood Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	2 hr
Jul 3, 7:22 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	21 min
Jul 3, 7:35 PM EDT	Special Weather Statement	PHI	Chester	25 min
Jul 3, 7:39 PM EDT	Severe Thunderstorm Warning	PHI	Chester	51 min
Jul 3, 7:54 PM EDT	Flash Flood Warning	PHI	Chester	4 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2018 Every flash flood warning in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.