Alert archive / New Jersey / Flash Flood Watches in 2018

Flash Flood Watch 15, NWS Philadelphia/Mount Holly

September 18, 20184 states

NWS Philadelphia/Mount Holly issued this flash flood watch at Sep 18, 2018, 9:27 AM EDT for 4 states. It took effect at Sep 18, 2018, 11:00 AM EDT. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued
Sep 18, 2018, 9:27 AM EDT (13:27 UTC)
In effect from
Sep 18, 2018, 11:00 AM EDT
Expired
Sep 18, 2018, 3:53 PM EDT
In force
5 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None
All 23 counties

New Castle County, DE, Cecil County, MD, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Morris County, NJ, Salem County, NJ, Somerset County, NJ, Sussex County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 77 km from the middle of the area, began a volume at 13:28 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, 1.5 hours before the alert went out and 205 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 2018-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1035 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 2018-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 220 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
1035 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
495 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
220 m²/s²
0-3 km storm-relative helicity
238 m²/s²
Significant tornado parameter
0.8
Supercell composite
4.3

Open this sounding in Storm Lab

The text

As transmitted.

824 
WGUS61 KPHI 181327
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Mount Holly NJ
927 AM EDT Tue Sep 18 2018



DEZ001-MDZ008-NJZ001-007>010-012-015>019-PAZ054-055-060>062-070-
071-101>106-182130-
/O.NEW.KPHI.FF.A.0015.180918T1500Z-180918T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Cecil-Sussex-Warren-Morris-Hunterdon-Somerset-
Middlesex-Mercer-Salem-Gloucester-Camden-Northwestern Burlington-
Carbon-Monroe-Berks-Lehigh-Northampton-Delaware-Philadelphia-
Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Wilmington, Elkton, Newton, Washington, 
Morristown, Flemington, Somerville, New Brunswick, Trenton, 
Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, 
Mount Holly, Jim Thorpe, Stroudsburg, Reading, Allentown, 
Bethlehem, Easton, Media, Philadelphia, Honey Brook, Oxford, 
West Chester, Kennett Square, Collegeville, Pottstown, 
Norristown, Lansdale, Chalfont, Perkasie, Morrisville, 
and Doylestown
927 AM EDT Tue Sep 18 2018

...FLASH FLOOD WATCH IN EFFECT UNTIL 7 PM EDT THIS EVENING...

The National Weather Service in Mount Holly has issued a

* Flash Flood Watch for portions of northern Delaware, northeast 
  Maryland, New Jersey, and Pennsylvania, including the 
  following areas, in northern Delaware, New Castle. In 
  northeast Maryland, Cecil. In New Jersey, Camden, Gloucester, 
  Hunterdon, Mercer, Middlesex, Morris, Northwestern Burlington, 
  Salem, Somerset, Sussex, and Warren. In Pennsylvania, Berks, 
  Carbon, Delaware, Eastern Chester, Eastern Montgomery, Lehigh, 
  Lower Bucks, Monroe, Northampton, Philadelphia, Upper Bucks, 
  Western Chester, and Western Montgomery. 

* Until 7 PM EDT this evening

* Showers and thunderstorms will develop along and ahead of a cold
  front as it moves south across the area this afternoon. Some of
  these storms will likely be heavy and could produce rainfall
  amounts in excess of 2 inches within 1 to 2 hours. This may
  result in flash flooding, especially for urban areas along the
  Interstate 95 corridor. 


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that there is the potential for flash
flooding which can be life-threatening. Heavy rain is expected to
occur over a short period of time. Rapidly rising flood waters
may quickly inundate roadways and areas of poor drainage. Streams
and creeks could leave their banks, flooding nearby properties.

Please monitor the forecast, especially if you live in a location
that is prone to flooding. Be prepared to take action if a flash 
flood warning is issued for your area.

&&

$$

Fitzsimmons
3 follow-up statements
305 
WGUS61 KPHI 181620
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
1220 PM EDT Tue Sep 18 2018


PAZ054-055-060-061-181730-
/O.CAN.KPHI.FF.A.0015.000000T0000Z-180918T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Carbon-Monroe-Berks-Lehigh-
Including the cities of Jim Thorpe, Stroudsburg, Reading, 
and Allentown
1220 PM EDT Tue Sep 18 2018

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of east central Pennsylvania
and northeast Pennsylvania has been cancelled. The cold front has
moved south of this area so heavy rain and flooding is no longer
expected. 

$$

DEZ001-MDZ008-NJZ001-007>010-012-015>019-PAZ062-070-071-101>106-
182300-
/O.CON.KPHI.FF.A.0015.000000T0000Z-180918T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Cecil-Sussex-Warren-Morris-Hunterdon-Somerset-
Middlesex-Mercer-Salem-Gloucester-Camden-Northwestern Burlington-
Northampton-Delaware-Philadelphia-Western Chester-Eastern Chester-
Western Montgomery-Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Wilmington, Elkton, Newton, Washington, 
Morristown, Flemington, Somerville, New Brunswick, Trenton, 
Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, 
Mount Holly, Bethlehem, Easton, Media, Philadelphia, Honey Brook,
Oxford, West Chester, Kennett Square, Collegeville, Pottstown, 
Norristown, Lansdale, Chalfont, Perkasie, Morrisville, 
and Doylestown
1220 PM EDT Tue Sep 18 2018

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 7 PM EDT THIS
EVENING...

The Flash Flood Watch continues for

* Portions of northern Delaware, northeast Maryland, New Jersey, 
  and Pennsylvania, including the following areas, in northern 
  Delaware, New Castle. In northeast Maryland, Cecil. In New 
  Jersey, Camden, Gloucester, Hunterdon, Mercer, Middlesex, 
  Morris, Northwestern Burlington, Salem, Somerset, Sussex, and 
  Warren. In Pennsylvania, Delaware, Eastern Chester, Eastern 
  Montgomery, Lower Bucks, Northampton, Philadelphia, Upper 
  Bucks, Western Chester, and Western Montgomery. 

* Until 7 PM EDT this evening

* Showers and thunderstorms will continue along and ahead of a 
  cold front as it moves south across the area this afternoon. 
  Some of these storms will likely be heavy and could produce 
  rainfall amounts in excess of 2 inches within 1 to 2 hours. This
  may result in flash flooding, especially for urban areas along 
  the Interstate 95 corridor. 


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that there is the potential for flash
flooding which can be life-threatening. Heavy rain is expected to
occur over a short period of time. Rapidly rising flood waters
may quickly inundate roadways and areas of poor drainage. Streams
and creeks could leave their banks, flooding nearby properties.

Please monitor the forecast, especially if you live in a location
that is prone to flooding. Be prepared to take action if a flash
flood warning is issued for your area.

&&

$$
268 
WGUS61 KPHI 181854
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
254 PM EDT Tue Sep 18 2018



NJZ001-007>009-PAZ062-101>103-105-182000-
/O.CAN.KPHI.FF.A.0015.000000T0000Z-180918T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex-Warren-Morris-Hunterdon-Northampton-Western Chester-
Eastern Chester-Western Montgomery-Upper Bucks-
Including the cities of Newton, Washington, Morristown, 
Flemington, Bethlehem, Easton, Honey Brook, Oxford, West Chester,
Kennett Square, Collegeville, Pottstown, Chalfont, and Perkasie
254 PM EDT Tue Sep 18 2018

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of New Jersey and Pennsylvania
has been cancelled. Heavy rain has ended with the passage of a
cold front and flash flooding is no longer expected. 

$$

DEZ001-MDZ008-NJZ010-012-015>019-PAZ070-071-104-106-182300-
/O.CON.KPHI.FF.A.0015.000000T0000Z-180918T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Cecil-Somerset-Middlesex-Mercer-Salem-Gloucester-
Camden-Northwestern Burlington-Delaware-Philadelphia-
Eastern Montgomery-Lower Bucks-
Including the cities of Wilmington, Elkton, Somerville, 
New Brunswick, Trenton, Pennsville, Glassboro, Camden, 
Cherry Hill, Moorestown, Mount Holly, Media, Philadelphia, 
Norristown, Lansdale, Morrisville, and Doylestown
254 PM EDT Tue Sep 18 2018

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 7 PM EDT THIS
EVENING...

The Flash Flood Watch continues for

* Portions of northern Delaware, northeast Maryland, New Jersey, 
  and southeast Pennsylvania, including the following areas, in 
  northern Delaware, New Castle. In northeast Maryland, Cecil. 
  In New Jersey, Camden, Gloucester, Mercer, Middlesex, 
  Northwestern Burlington, Salem, and Somerset. In southeast 
  Pennsylvania, Delaware, Eastern Montgomery, Lower Bucks, and 
  Philadelphia. 

* Until 7 PM EDT this evening

* Showers and thunderstorms continue to affect the area along a
  cold front moving through from north to south. Radar estimates 
  indicate that some areas along the urban corridor have seen 1 to
  2+ inches of rain within the past couple hours with waters 
  rising on creeks and streams. Urban and small stream flooding 
  along with localized areas of flash flooding will remain 
  possible this afternoon with the front clearing the area by this
  evening bringing rain to an end. 


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that there is the potential for flash
flooding which can be life-threatening. Heavy rain is expected to
occur over a short period of time. Rapidly rising flood waters
may quickly inundate roadways and areas of poor drainage. Streams
and creeks could leave their banks, flooding nearby properties.

Please monitor the forecast, especially if you live in a location
that is prone to flooding. Be prepared to take action if a flash
flood warning is issued for your area.

&&

$$

Fitzsimmons
428 
WGUS61 KPHI 181953
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
353 PM EDT Tue Sep 18 2018



DEZ001-MDZ008-NJZ010-012-015>019-PAZ070-071-104-106-182100-
/O.CAN.KPHI.FF.A.0015.000000T0000Z-180918T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Cecil-Somerset-Middlesex-Mercer-Salem-Gloucester-
Camden-Northwestern Burlington-Delaware-Philadelphia-
Eastern Montgomery-Lower Bucks-
Including the cities of Wilmington, Elkton, Somerville, 
New Brunswick, Trenton, Pennsville, Glassboro, Camden, 
Cherry Hill, Moorestown, Mount Holly, Media, Philadelphia, 
Norristown, Lansdale, Morrisville, and Doylestown
353 PM EDT Tue Sep 18 2018

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of northern Delaware,
northeast Maryland, New Jersey, and southeast Pennsylvania has
been cancelled. The heaviest rain has cleared the area and flash
flooding is no longer expected. 



$$

Fitzsimmons

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 18, 4:13 AM EDTSpecial Weather StatementPHICamden, Gloucester, Salem92 min
Sep 18, 10:59 AM EDTAreal Flood AdvisoryPHIHunterdon, Mercer, Middlesex, Monmouth, Somerset4 hr
Sep 18, 12:01 PM EDTFlash Flood WarningPHIMercer, Middlesex, Somerset4 hr
Sep 18, 12:16 PM EDTSpecial Weather StatementPHIMiddlesex29 min
Sep 18, 12:36 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester, Mercer, Middlesex, Monmouth and 2 more3 hr
Sep 18, 1:20 PM EDTSpecial Weather StatementPHIBurlington25 min
Sep 18, 1:35 PM EDTSpecial Marine WarningPHI55 min
Sep 18, 2:51 PM EDTSpecial Marine WarningPHI38 min
Sep 18, 2:55 PM EDTSpecial Weather StatementPHIOcean35 min
Sep 18, 3:02 PM EDTAreal Flood AdvisoryPHIBurlington, Ocean3 hr
Sep 18, 3:12 PM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Camden, Ocean47 min
Sep 18, 3:47 PM EDTSpecial Weather StatementPHIOcean28 min
Sep 18, 4:12 PM EDTSpecial Weather StatementPHIAtlantic33 min
Sep 18, 4:47 PM EDTAreal Flood AdvisoryPHIAtlantic, Cape May, Cumberland, Ocean2 hr
Sep 18, 5:17 PM EDTFlash Flood WarningPHIAtlantic113 min
Sep 18, 1:13 AM EDTSpecial Weather StatementPHIChester62 min
Sep 18, 2:09 AM EDTSpecial Weather StatementPHIChester, Delaware, Montgomery, Philadelphia81 min
Sep 18, 2:38 AM EDTAreal Flood AdvisoryPHIChester, Montgomery4 hr
Sep 18, 6:27 AM EDTAreal Flood AdvisoryPHICarbon, Monroe4 hr
Sep 18, 10:57 AM EDTAreal Flood AdvisoryPHIBucks, Chester, Delaware, Montgomery, Philadelphia3 hr
Sep 18, 5:26 PM EDTSpecial Weather StatementPHISussex34 min

Nearby

Flash Flood Watches in New Jersey, 2018Flash Flood Watches in Pennsylvania, 2018Flash Flood Watches in Maryland, 2018Every flash flood watch 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.