Alert archive / Pennsylvania / Areal Flood Warnings in 2018

Areal Flood Warning 13, NWS Philadelphia/Mount Holly

April 16, 2018Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood warning at Apr 16, 2018, 8:44 AM EDT for Philadelphia County, Pennsylvania. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Apr 16, 2018, 8:44 AM EDT (12:44 UTC)
Expired: Apr 16, 2018, 10:45 AM EDT
In force: 2 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

County Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 54 km from the middle of the area, began a volume at 12:45 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.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 0.7 hours before the alert went out and 203 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: 7 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 391 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 902 m²/s²
0-3 km storm-relative helicity: 990 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

As transmitted.

509 
WGUS41 KPHI 161244
FLWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
844 AM EDT MON APR 16 2018

PAC101-161445-
/O.NEW.KPHI.FA.W.0013.180416T1244Z-180416T1445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Philadelphia PA-
844 AM EDT MON APR 16 2018

The National Weather Service in Mount Holly NJ has issued a

* Flood Warning for...
  Northeastern Philadelphia County in southeastern Pennsylvania...

* Until 1045 AM EDT

* At 841 AM EDT, the stream gage on the Pennypack Creek in Northeast 
  Philadelphia was reading 7.1 feet. Flood stage is 7.0 feet. The 
  water level at this location is expected to rise another foot or 
  so before cresting later this morning. It should fall back down 
  below flood stage before noon.

 *LAT...LON 4006 7498 4005 7498 3998 7510 4005 7511
      4006 7509 4008 7509 4014 7501 4012 7496
      4008 7496

$$

jjm

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 16, 12:32 AM EDT	Winter Weather Advisory	PHI	Carbon, Monroe	8 hr
Apr 16, 5:34 AM EDT	Areal Flood Advisory	PHI	Chester, Delaware	4 hr
Apr 16, 5:52 AM EDT	Areal Flood Advisory	PHI	Bucks, Delaware, Montgomery, Philadelphia	7 hr
Apr 16, 6:30 AM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Chester, Lehigh, Montgomery, Northampton	4 hr
Apr 16, 7:04 AM EDT	Flash Flood Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	4 hr
Apr 16, 7:26 AM EDT	Special Weather Statement	PHI	Bucks, Philadelphia	34 min
Apr 16, 7:45 AM EDT	River Flood Warning	PHI	Delaware	4 hr
Apr 16, 9:26 AM EDT	Areal Flood Warning	PHI	Bucks	4 hr
Apr 16, 10:45 AM EDT	Areal Flood Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	4 hr
Apr 16, 11:41 AM EDT	River Flood Warning	PHI	Bucks	12 hr
Apr 16, 12:04 PM EDT	Special Weather Statement	PHI	Chester	26 min
Apr 16, 1:31 PM EDT	Areal Flood Warning	PHI	Bucks, Philadelphia	4 hr
Apr 16, 2:27 PM EDT	Areal Flood Warning	PHI	Montgomery, Philadelphia	5 hr
Apr 16, 2:45 PM EDT	Coastal Flood Warning	PHI	Bucks, Delaware, Philadelphia	3 hr

Nearby

Areal Flood Warnings in Pennsylvania, 2018 Every areal 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; radar from the NEXRAD Level II archive.