Alert archive / New Jersey / Flash Flood Watches in 2017

Flash Flood Watch 3, NWS Philadelphia/Mount Holly

July 14, 20174 states

NWS Philadelphia/Mount Holly issued this flash flood watch at Jul 14, 2017, 11:40 AM EDT for 4 states. It took effect at Jul 14, 2017, 2:00 PM EDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued
Jul 14, 2017, 11:40 AM EDT (15:40 UTC)
In effect from
Jul 14, 2017, 2:00 PM EDT
Expired
Jul 14, 2017, 10:32 PM EDT
In force
9 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None

Counties Kent County, DE, New Castle County, DE, Cecil County, MD, Kent County, MD, Queen Anne's County, MD, Atlantic County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Salem County, NJ, Berks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Dover AFB radar (KDOX), 89 km from the middle of the area, began a volume at 15:41 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 3.7 hours before the alert went out and 185 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, Washington/Dulle, VA at 12:00Z on 2017-07-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 403 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, Washington/Dulle, VA at 12:00Z on 2017-07-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 52 square meters per square second.193958Sfc1 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
403 J/kg
Mixed-layer CIN
-72 J/kg
Mixed-layer LCL
1367 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
52 m²/s²
0-3 km storm-relative helicity
118 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

001 
WGUS61 KPHI 141540
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Mount Holly NJ
1140 AM EDT Fri Jul 14 2017

DEZ001-002-MDZ008-012-015-NJZ016>018-021>025-PAZ060-070-071-
101>104-142345-
/O.NEW.KPHI.FF.A.0003.170714T1800Z-170715T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Kent-Cecil-Kent MD-Queen Annes-Salem-Gloucester-Camden-
Cumberland-Atlantic-Cape May-Atlantic Coastal Cape May-
Coastal Atlantic-Berks-Delaware-Philadelphia-Western Chester-
Eastern Chester-Western Montgomery-Eastern Montgomery-
Including the cities of Wilmington, Dover, Elkton, Chestertown, 
Centreville, Pennsville, Glassboro, Camden, Cherry Hill, 
Millville, Hammonton, Cape May Court House, Ocean City, 
Atlantic City, Reading, Media, Philadelphia, Honey Brook, Oxford,
West Chester, Kennett Square, Collegeville, Pottstown, 
Norristown, and Lansdale
1140 AM EDT Fri Jul 14 2017

...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING...

The National Weather Service in Mount Holly has issued a

* Flash Flood Watch for portions of southeastern Pennsylvania,
  southern New Jersey, eastern Maryland and Delaware.

* Until midnight EDT tonight.

* Showers and thunderstorms that develop this afternoon will
  contain torrential downpours. There is a potential for some
  locations to see multiple rounds of storms through this evening.
  Some locations could receive rainfall amounts of 2 to 4 inches
  in just a short period, which could produce flash flooding.
 
* Flash flooding of creeks, streams and roadways will be possible,
  especially in urban and poor drainage areas. Additionally, areas
  in Berks and Montgomery Counties in Pennsylvania and in far
  southern New Jersey that received heavy rainfall since yesterday
  afternoon will be susceptible to flash flooding. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$
JRK
3 follow-up statements
892 
WGUS61 KPHI 142141
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
541 PM EDT Fri Jul 14 2017

NJZ018-PAZ060-071-103-104-142245-
/O.CAN.KPHI.FF.A.0003.000000T0000Z-170715T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Camden-Berks-Philadelphia-Western Montgomery-Eastern Montgomery-
Including the cities of Camden, Cherry Hill, Reading, 
Philadelphia, Collegeville, Pottstown, Norristown, and Lansdale
541 PM EDT Fri Jul 14 2017

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of southern New Jersey and
Pennsylvania has been cancelled. The threat of heavy rainfall and
flash flooding for this evening has shifted south of Reading and 
Philadelphia.

$$

DEZ001-002-MDZ008-012-015-NJZ016-017-021>025-PAZ070-101-102-
150400-
/O.CON.KPHI.FF.A.0003.000000T0000Z-170715T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Kent-Cecil-Kent MD-Queen Annes-Salem-Gloucester-
Cumberland-Atlantic-Cape May-Atlantic Coastal Cape May-
Coastal Atlantic-Delaware-Western Chester-Eastern Chester-
Including the cities of Wilmington, Dover, Elkton, Chestertown, 
Centreville, Pennsville, Glassboro, Millville, Hammonton, 
Cape May Court House, Ocean City, Atlantic City, Media, 
Honey Brook, Oxford, West Chester, and Kennett Square
541 PM EDT Fri Jul 14 2017

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL MIDNIGHT EDT
TONIGHT...

The Flash Flood Watch continues for

* Portions of far southeastern Pennsylvania, southern New Jersey,
  eastern Maryland and Delaware.

* Until midnight EDT tonight

* A line of showers and thunderstorms containing torrential
  downpours will continue to push southeastward through eastern
  Maryland, central and southern Delaware and far southern New
  Jersey during the early evening. Rainfall amounts of 2 to 3
  inches in less than an hour are occuring with these storms,
  which could lead to flash flooding. 

* Additional storms developing behind this line may move back into
  locations that already saw heavy rainfall this afternoon in far
  southeastern Pennsylvania, northeastern Maryland and northern
  Delaware later this evening.

* Flash flooding of creeks, streams and roadways will be possible,
  especially in urban and poor drainage areas. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$
385 
WGUS61 KPHI 150122
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
922 PM EDT Fri Jul 14 2017


DEZ002-NJZ016-017-021>025-150230-
/O.CAN.KPHI.FF.A.0003.000000T0000Z-170715T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent-Salem-Gloucester-Cumberland-Atlantic-Cape May-
Atlantic Coastal Cape May-Coastal Atlantic-
Including the cities of Dover, Pennsville, Glassboro, Millville, 
Hammonton, Cape May Court House, Ocean City, and Atlantic City
922 PM EDT Fri Jul 14 2017

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of central Delaware and
southern New Jersey has been cancelled.

$$

DEZ001-MDZ008-012-015-PAZ070-101-102-150400-
/O.CON.KPHI.FF.A.0003.000000T0000Z-170715T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Cecil-Kent MD-Queen Annes-Delaware-Western Chester-
Eastern Chester-
Including the cities of Wilmington, Elkton, Chestertown, 
Centreville, Media, Honey Brook, Oxford, West Chester, 
and Kennett Square
922 PM EDT Fri Jul 14 2017

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL MIDNIGHT EDT
TONIGHT...

The Flash Flood Watch continues for

* Portions of northern Delaware, northeast Maryland, and 
  southeast Pennsylvania, including the following areas, in 
  northern Delaware, New Castle. In northeast Maryland, Cecil, 
  Kent MD, and Queen Annes. In southeast Pennsylvania, Delaware, 
  Eastern Chester, and Western Chester. 

* Until midnight EDT tonight

* Scattered thunderstorms with torrential rainfall in south
  central Pennsylvania this evening may still arrive toward
  midnight in parts of our area. However, the chance of any flash
  flood producing rainfall in our area is lessening.
  
 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$
875 
WGUS61 KPHI 150232
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
1032 PM EDT Fri Jul 14 2017

DEZ001-MDZ008-012-015-PAZ070-101-102-150345-
/O.CAN.KPHI.FF.A.0003.000000T0000Z-170715T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Cecil-Kent MD-Queen Annes-Delaware-Western Chester-
Eastern Chester-
Including the cities of Wilmington, Elkton, Chestertown, 
Centreville, Media, Honey Brook, Oxford, West Chester, 
and Kennett Square
1032 PM EDT Fri Jul 14 2017

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of northern Delaware,
northeast Maryland, and southeast Pennsylvania has been
cancelled. The threat of any additional flash flooding continues
to decrease.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 13, 8:17 PM EDTSpecial Weather StatementPHIMontgomery, Philadelphia43 min
Jul 14, 7:21 AM EDTAreal Flood AdvisoryPHICarbon, Monroe, Northampton3 hr
Jul 14, 12:30 PM EDTAreal Flood AdvisoryPHIBerks, Carbon, Lehigh, Monroe, Montgomery, Northampton4 hr
Jul 14, 1:58 PM EDTSpecial Weather StatementPHIChester62 min
Jul 14, 2:14 PM EDTAreal Flood AdvisoryPHIChester, Delaware, Montgomery, Philadelphia3 hr
Jul 14, 2:31 PM EDTSevere Thunderstorm WarningPHIChester, Delaware59 min
Jul 14, 2:53 PM EDTFlash Flood WarningPHIChester, Delaware, Montgomery, Philadelphia3 hr
Jul 14, 2:57 PM EDTAreal Flood AdvisoryPHIBucks, Montgomery3 hr
Jul 14, 3:18 PM EDTSevere Thunderstorm WarningPHIChester, Delaware12 min
Jul 14, 3:23 PM EDTSevere Thunderstorm WarningPHIChester, Delaware67 min
Jul 13, 10:03 PM EDTSpecial Weather StatementPHICaroline27 min
Jul 13, 10:15 PM EDTAreal Flood AdvisoryPHICaroline, Talbot4 hr
Jul 14, 9:23 AM EDTSpecial Weather StatementPHICecil37 min
Jul 14, 12:06 PM EDTHeat AdvisoryPHICaroline, Kent, Queen Anne's, Talbot7 hr
Jul 14, 2:46 PM EDTAreal Flood AdvisoryPHICecil3 hr
Jul 14, 3:10 PM EDTFlash Flood WarningPHICecil2 hr
Jul 14, 3:52 PM EDTFlash Flood WarningPHITalbot53 min
Jul 14, 3:57 PM EDTFlash Flood WarningPHICecil, Kent2 hr
Jul 14, 4:00 PM EDTSpecial Weather StatementPHICaroline45 min
Jul 14, 4:05 PM EDTSpecial Weather StatementPHIKent40 min
Jul 14, 4:48 PM EDTSpecial Weather StatementPHIQueen Anne's27 min
Jul 14, 4:59 PM EDTFlash Flood WarningPHIQueen Anne's4 hr
Jul 14, 5:27 PM EDTSpecial Weather StatementPHIQueen Anne's63 min
Jul 14, 5:40 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot65 min
Jul 14, 5:54 PM EDTSevere Thunderstorm WarningPHICaroline, Talbot51 min
Jul 14, 5:58 PM EDTFlash Flood WarningPHITalbot3 hr
Jul 14, 6:10 PM EDTFlash Flood WarningPHICaroline3 hr
Jul 14, 6:20 PM EDTSevere Thunderstorm WarningPHICaroline, Talbot40 min
Jul 13, 8:26 PM EDTSpecial Weather StatementPHICape May34 min
Jul 13, 8:27 PM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more4 hr
Jul 13, 8:49 PM EDTSpecial Weather StatementPHICumberland26 min
Jul 13, 8:51 PM EDTSpecial Weather StatementPHIAtlantic54 min
Jul 13, 9:07 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cape May, Cumberland, Gloucester, Salem53 min
Jul 13, 9:46 PM EDTSpecial Weather StatementPHIAtlantic14 min
Jul 13, 9:50 PM EDTSpecial Marine WarningPHI115 min
Jul 13, 9:57 PM EDTSpecial Weather StatementPHICape May33 min
Jul 13, 10:42 PM EDTSpecial Marine WarningPHI93 min
Jul 14, 3:07 PM EDTSpecial Marine WarningPHI53 min
Jul 14, 3:25 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Cumberland, Gloucester, Ocean, Salem4 hr
Jul 14, 3:34 PM EDTFlash Flood WarningPHIGloucester, Salem3 hr
Jul 14, 3:35 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cumberland, Gloucester55 min
Jul 14, 3:43 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Camden, Gloucester, Salem47 min
Jul 14, 3:47 PM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Ocean3 hr
Jul 14, 3:54 PM EDTSevere Thunderstorm WarningPHICumberland, Gloucester, Salem66 min
Jul 14, 4:12 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cape May63 min
Jul 14, 4:13 PM EDTFlash Flood WarningPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more3 hr
Jul 14, 4:18 PM EDTSpecial Marine WarningPHI57 min
Jul 14, 4:25 PM EDTSpecial Marine WarningPHI95 min
Jul 14, 4:44 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cape May, Cumberland, Gloucester, Salem61 min
Jul 14, 4:54 PM EDTSpecial Marine WarningPHI66 min
Jul 14, 5:47 PM EDTSpecial Weather StatementPHICape May13 min
Jul 14, 5:53 PM EDTSpecial Marine WarningPHI52 min
Jul 14, 6:32 PM EDTSpecial Marine WarningPHI88 min
Jul 14, 7:08 PM EDTSpecial Marine WarningPHI97 min
Jul 14, 7:28 PM EDTAreal Flood AdvisoryPHIAtlantic, Camden, Cape May, Cumberland, Gloucester, Salem3 hr
Jul 13, 8:09 PM EDTSpecial Weather StatementPHIKent36 min
Jul 13, 8:29 PM EDTSpecial Weather StatementPHIKent31 min
Jul 13, 10:39 PM EDTSevere Thunderstorm WarningPHISussex51 min
Jul 14, 9:02 AM EDTSpecial Weather StatementPHINew Castle28 min
Jul 14, 5:14 PM EDTAreal Flood AdvisoryPHIKent3 hr
Jul 14, 5:24 PM EDTSpecial Weather StatementPHISussex36 min
Jul 14, 5:30 PM EDTRiver Flood WarningPHINew Castle7 hr
Jul 14, 5:51 PM EDTSpecial Weather StatementPHISussex39 min
Jul 14, 6:32 PM EDTAreal Flood AdvisoryPHISussex4 hr
Jul 14, 6:48 PM EDTSpecial Weather StatementPHISussex42 min
Jul 14, 7:15 PM EDTSevere Thunderstorm WarningPHISussex60 min

Nearby

Flash Flood Watches in New Jersey, 2017Flash Flood Watches in Pennsylvania, 2017Flash Flood Watches in Maryland, 2017Every flash flood watch in 2017

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.