Alert archive / New Jersey / Flash Flood Watches in 2019

Flash Flood Watch 13, NWS Philadelphia/Mount Holly

August 12, 20198 counties in Pennsylvania; 11 counties in New Jersey

NWS Philadelphia/Mount Holly issued this flash flood watch at Aug 12, 2019, 3:34 PM EDT for 8 counties in Pennsylvania; 11 counties in New Jersey. It took effect at Aug 13, 2019, 2:00 PM EDT. It was in force for 46 min.

The area

The counties it named.

The facts

Issued
Aug 12, 2019, 3:34 PM EDT (19:34 UTC)
In effect from
Aug 13, 2019, 2:00 PM EDT
Expired
Aug 13, 2019, 2:46 PM EDT
In force
46 min
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None

Counties Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Ocean County, NJ, Somerset County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 62 km from the middle of the area, began a volume at 19:38 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, 7.6 hours before the alert went out and 191 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 2019-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2019-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1732 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
59 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

648 
WGUS61 KPHI 121934
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Mount Holly NJ
334 PM EDT Mon Aug 12 2019

NJZ007>010-012>015-017>020-026-027-PAZ060>062-070-071-101>106-
131000-
/O.NEW.KPHI.FF.A.0013.190813T1800Z-190814T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Warren-Morris-Hunterdon-Somerset-Middlesex-Western Monmouth-
Eastern Monmouth-Mercer-Gloucester-Camden-Northwestern Burlington-
Ocean-Coastal Ocean-Southeastern Burlington-Berks-Lehigh-
Northampton-Delaware-Philadelphia-Western Chester-Eastern Chester-
Western Montgomery-Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Washington, Morristown, Flemington, 
Somerville, New Brunswick, Freehold, Sandy Hook, Trenton, 
Glassboro, Camden, Cherry Hill, Moorestown, Mount Holly, Jackson,
Long Beach Island, Wharton State Forest, Reading, Allentown, 
Bethlehem, Easton, Media, Philadelphia, Honey Brook, Oxford, 
West Chester, Kennett Square, Collegeville, Pottstown, 
Norristown, Lansdale, Chalfont, Perkasie, Morrisville, 
and Doylestown
334 PM EDT Mon Aug 12 2019

...FLASH FLOOD WATCH IN EFFECT FROM TUESDAY AFTERNOON THROUGH
TUESDAY EVENING...

The National Weather Service in Mount Holly has issued a

* Flash Flood Watch for southeastern Pennsylvania and much of New
  Jersey.

* From Tuesday afternoon through Tuesday evening

* Showers and thunderstorms will begin to develop around midday
  and continue through the afternoon and evening hours. Periods of
  heavy rain can be expected with areas of 1 to 2 inches, with
  local amounts up to 5 inches possible. These rainfall totals may
  occur in a short amount of time, and could lead to flash
  flooding.

* The risk of flash flooding is highest in urbanized and low- 
  lying areas. Rapid rises on small creeks and streams are 
  possible.

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.

&&

$$

CMS
3 follow-up statements
043 
WGUS61 KPHI 130725
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
325 AM EDT Tue Aug 13 2019

NJZ007>010-PAZ060>062-130830-
/O.CAN.KPHI.FF.A.0013.190813T1800Z-190814T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Warren-Morris-Hunterdon-Somerset-Berks-Lehigh-Northampton-
Including the cities of Washington, Morristown, Flemington, 
Somerville, Reading, Allentown, Bethlehem, and Easton
325 AM EDT Tue Aug 13 2019

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of northern New Jersey and 
east central Pennsylvania has been cancelled. The threat for the
heaviest rainfall has shifted farther south into central and
southern New Jersey and far southeast Pennsylvania.

$$

NJZ012>015-017>020-026-027-PAZ070-071-101>106-131530-
/O.CON.KPHI.FF.A.0013.190813T1800Z-190814T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Middlesex-Western Monmouth-Eastern Monmouth-Mercer-Gloucester-
Camden-Northwestern Burlington-Ocean-Coastal Ocean-
Southeastern Burlington-Delaware-Philadelphia-Western Chester-
Eastern Chester-Western Montgomery-Eastern Montgomery-Upper Bucks-
Lower Bucks-
Including the cities of New Brunswick, Freehold, Sandy Hook, 
Trenton, Glassboro, Camden, Cherry Hill, Moorestown, Mount Holly,
Jackson, Long Beach Island, Wharton State Forest, Media, 
Philadelphia, Honey Brook, Oxford, West Chester, Kennett Square, 
Collegeville, Pottstown, Norristown, Lansdale, Chalfont, 
Perkasie, Morrisville, and Doylestown
325 AM EDT Tue Aug 13 2019

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM 2 PM EDT THIS
AFTERNOON THROUGH THIS EVENING...

The Flash Flood Watch continues for

* Portions of New Jersey and southeast Pennsylvania, including 
  the following areas, in New Jersey, Camden, Coastal Ocean, 
  Eastern Monmouth, Gloucester, Mercer, Middlesex, Northwestern 
  Burlington, Ocean, Southeastern Burlington, and Western 
  Monmouth. In southeast Pennsylvania, Delaware, Eastern 
  Chester, Eastern Montgomery, Lower Bucks, Philadelphia, Upper 
  Bucks, Western Chester, and Western Montgomery. 

* From 2 PM EDT this afternoon through this evening

* Showers and thunderstorms will begin to develop around midday
  and continue through the afternoon and evening hours. Periods of
  heavy rain can be expected with areas of 1 to 2 inches, with
  local amounts up to 3 inches possible. These rainfall totals 
  may occur in a short amount of time, and could lead to flash 
  flooding. 

* The risk of flash flooding is highest in urbanized and low- 
  lying areas. Rapid rises on small creeks and streams are 
  possible. 

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.

&&

$$

Staarmann
172 
WGUS61 KPHI 131626
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
1226 PM EDT Tue Aug 13 2019



NJZ012>015-017>020-026-027-PAZ070-071-101>106-140130-
/O.CON.KPHI.FF.A.0013.190813T1800Z-190814T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Middlesex-Western Monmouth-Eastern Monmouth-Mercer-Gloucester-
Camden-Northwestern Burlington-Ocean-Coastal Ocean-
Southeastern Burlington-Delaware-Philadelphia-Western Chester-
Eastern Chester-Western Montgomery-Eastern Montgomery-Upper Bucks-
Lower Bucks-
Including the cities of New Brunswick, Freehold, Sandy Hook, 
Trenton, Glassboro, Camden, Cherry Hill, Moorestown, Mount Holly,
Jackson, Long Beach Island, Wharton State Forest, Media, 
Philadelphia, Honey Brook, Oxford, West Chester, Kennett Square, 
Collegeville, Pottstown, Norristown, Lansdale, Chalfont, 
Perkasie, Morrisville, and Doylestown
1226 PM EDT Tue Aug 13 2019

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

The Flash Flood Watch continues for

* Portions of New Jersey and southeast Pennsylvania, including 
  the following areas, in New Jersey, Camden, Coastal Ocean, 
  Eastern Monmouth, Gloucester, Mercer, Middlesex, Northwestern 
  Burlington, Ocean, Southeastern Burlington, and Western 
  Monmouth. In southeast Pennsylvania, Delaware, Eastern 
  Chester, Eastern Montgomery, Lower Bucks, Philadelphia, Upper 
  Bucks, Western Chester, and Western Montgomery. 

* Until midnight EDT tonight

* Showers with embedded thunderstorms can be expected across the
  area this afternoon. Any storms will be capable of producing
  heavy rain which could lead to localized flash flooding if
  repeated storms it the same area. 

* The risk of flash flooding is highest in urbanized and low- 
  lying areas. Rapid rises on small creeks and streams are 
  possible. 

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
543 
WGUS61 KPHI 131846
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
246 PM EDT Tue Aug 13 2019



NJZ012>015-017>020-026-027-PAZ070-071-101>106-132000-
/O.CAN.KPHI.FF.A.0013.000000T0000Z-190814T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Middlesex-Western Monmouth-Eastern Monmouth-Mercer-Gloucester-
Camden-Northwestern Burlington-Ocean-Coastal Ocean-
Southeastern Burlington-Delaware-Philadelphia-Western Chester-
Eastern Chester-Western Montgomery-Eastern Montgomery-Upper Bucks-
Lower Bucks-
Including the cities of New Brunswick, Freehold, Sandy Hook, 
Trenton, Glassboro, Camden, Cherry Hill, Moorestown, Mount Holly,
Jackson, Long Beach Island, Wharton State Forest, Media, 
Philadelphia, Honey Brook, Oxford, West Chester, Kennett Square, 
Collegeville, Pottstown, Norristown, Lansdale, Chalfont, 
Perkasie, Morrisville, and Doylestown
246 PM EDT Tue Aug 13 2019

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of New Jersey and southeast
Pennsylvania has been cancelled. Showers with embedded
thunderstorms could still produce locally heavy rain this
afternoon into this evening but flash flooding is not expected. 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 3:46 PM EDTSmall Craft AdvisoryPHI29 hr

Nearby

Flash Flood Watches in New Jersey, 2019Flash Flood Watches in Pennsylvania, 2019Every flash flood watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.