Alert archive / Delaware / Flash Flood Warnings in 2018

Flash Flood Warning 93, NWS Philadelphia/Mount Holly

September 3, 2018Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 3, 2018, 4:48 PM EDT for Sussex County, Delaware. 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: Sep 3, 2018, 4:48 PM EDT (20:48 UTC)
Expired: Sep 3, 2018, 7:05 PM EDT
In force: 2 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

County Sussex County, DE

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 8.8 hours before the alert went out and 97 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: 1536 J/kg
Mixed-layer CIN: -16 J/kg
Mixed-layer LCL: 790 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -21 m²/s²
0-3 km storm-relative helicity: -26 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

679 
WGUS51 KPHI 032048
FFWPHI
DEC005-040045-
/O.NEW.KPHI.FF.W.0093.180903T2048Z-180904T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
448 PM EDT MON SEP 3 2018

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Sussex County in southern Delaware...

* Until 845 PM EDT.

* At 448 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between one and two inches of 
  rain have already fallen. Flash flooding is expected to begin 
  shortly in the areas of heaviest rain.

* Some locations that could experience flooding include...
  Georgetown, Milford, Seaford, Millsboro, Laurel, Milton,
  Bridgeville, Delmar, Ellendale, Gumboro, Sycamore, Blades,
  Greenwood and Bethel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Move to higher ground now. Act quickly to protect your life.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

Please report flooding to your local law enforcement agency when you
can do so safely.

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 3846 7569 3883 7572 3884 7555 3890 7549
      3892 7541 3896 7539 3896 7536 3904 7536
      3894 7531 3845 7526

$$

MPS

2 follow-up statements

126 
WGUS71 KPHI 032134
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
534 PM EDT MON SEP 3 2018

DEC005-040045-
/O.CON.KPHI.FF.W.0093.000000T0000Z-180904T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-
534 PM EDT MON SEP 3 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM EDT FOR
WESTERN SUSSEX COUNTY...

At 534 PM EDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Up to two inches of rain have already
fallen. Flash flooding is expected to begin shortly.

Some locations that could experience flooding include...
Milford, Seaford, Laurel, Bridgeville, Ellendale, Sycamore, Blades,
Greenwood and Bethel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Move to higher ground now. Act quickly to protect your life.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

Please report flooding to your local law enforcement agency when you
can do so safely.

&&

LAT...LON 3851 7569 3883 7572 3884 7555 3890 7549
      3892 7540 3887 7531 3867 7544 3852 7552

$$

MPS

295 
WGUS71 KPHI 032305
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
705 PM EDT MON SEP 3 2018

DEC005-032315-
/O.CAN.KPHI.FF.W.0093.000000T0000Z-180904T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-
705 PM EDT MON SEP 3 2018

...THE FLASH FLOOD WARNING FOR WESTERN SUSSEX COUNTY IS CANCELLED...

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

LAT...LON 3851 7569 3883 7572 3884 7555 3890 7549
      3892 7540 3887 7531 3867 7544 3852 7552

$$

MPS

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 3, 3:02 AM EDT	Heat Advisory	PHI	New Castle	4 days
Sep 3, 4:00 PM EDT	Areal Flood Advisory	PHI	Kent, New Castle	3 hr
Sep 3, 4:22 PM EDT	Areal Flood Advisory	PHI	Kent, Sussex	31 min

Nearby

Flash Flood Warnings in Delaware, 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.