Alert archive / Delaware / Flash Flood Warnings in 2020
Flash Flood Warning 16, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 10, 2020, 6:34 AM EDT for Sussex County, Delaware. It was in force for 6 hr. 4 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Jul 10, 2020, 6:34 AM EDT (10:34 UTC)
- Expired
- Jul 10, 2020, 12:30 PM EDT
- In force
- 6 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
County Sussex County, DE
The radar
The Dover AFB radar (KDOX), 39 km from the middle of the area, began a volume at 10:39 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 10, 6:41 AM EDT | FLOOD | 3 W Long Neck, DE | FLOODING OF ROADS AND RESIDENTIAL AREAS NEAR LONG NECK. |
| Jul 10, 6:54 AM EDT | FLASH FLOOD | Bethany Beach, DE | ESTIMATED 1 TO 2.5 FEET OF WATER INUNDATING ROADS IN BETHANY BEACH. REPORT VIA SOCIAL MEDIA WITH VIDEO. |
| Jul 10, 7:00 AM EDT | FLASH FLOOD | 2 Sw Long Neck, DE | RIVER ROAD AND OAK ORCHARD AVENUE CLOSED FROM FLOODING. TIME ESTIMATED BASED ON SURROUNDING REPORTS AND GAUGE OBSERVATIONS. |
| Jul 10, 7:30 AM EDT | FLASH FLOOD | 5 Ne Harbeson, DE | CAVE NECK ROAD CLOSED EAST OF MILTON FROM FLOODING. TIME ESTIMATED FROM RADAR AND NEARBY REPORTS. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Wallops Is Stn, VA (KWAL), launched 00:00Z, 10.6 hours before the alert went out and 74 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.
- Mixed-layer CAPE
- 402 J/kg
- Mixed-layer CIN
- -13 J/kg
- Mixed-layer LCL
- 649 m above ground
- 0-6 km bulk shear
- 8 kt
- 0-1 km storm-relative helicity
- 22 m²/s²
- 0-3 km storm-relative helicity
- 16 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
618
WGUS51 KPHI 101034
FFWPHI
DEC005-101630-
/O.NEW.KPHI.FF.W.0016.200710T1034Z-200710T1630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
634 AM EDT Fri Jul 10 2020
The National Weather Service in Mount Holly NJ has issued a
* Flash Flood Warning for...
Southeastern Sussex County in southern Delaware...
* Until 1230 PM EDT.
* At 632 AM EDT, Doppler radar and automated gauges indicated heavy
rain falling across the warned area. Up to two inches of rain have
already fallen. Flash flooding is imminent or occurring,
especially in coastal locations.
HAZARD...Flash flooding caused by heavy rain.
SOURCE...Radar and automated gauges.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other
drainage and low lying areas.
* Some locations that could experience flooding include...
Millsboro, Lewes, Dagsboro, Millville, Henlopen Acres, Cape
Henlopen State Park, Long Neck, Ocean View, Frankford, South
Bethany and Dewey Beach.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Protecting yourself from immediate threats to life and safety shall
take priority. Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.
Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3859 7530 3883 7527 3882 7508 3845 7502
3845 7504 3846 7505 3845 7505 3845 7521
FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...1-3 INCHES IN 1 HOUR
$$
CMS3 follow-up statements
145
WGUS71 KPHI 101210
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
810 AM EDT Fri Jul 10 2020
DEC005-101630-
/O.CON.KPHI.FF.W.0016.000000T0000Z-200710T1630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-
810 AM EDT Fri Jul 10 2020
...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1230 PM EDT FOR
SOUTHEASTERN SUSSEX COUNTY...
At 802 AM EDT, Doppler radar and automated gauges indicated heavy
rain falling across the warned area. Up to three inches of rain have
already fallen.
Another rainband just crossed the warned area with rain rates in the
3.00 to 6.00 inch per hour range.
Tidal gauges along Rehoboth Bay and Indian River Bay indicate tides
are struggling to recede. This will likely impede rainfall runoff.
Between the rainfall and tides, portions of Route 1 will likely see
flooding.
HAZARD...Flash flooding caused by heavy rain.
SOURCE...Radar and automated gauges.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other drainage
and low lying areas.
Some locations that could experience flooding include...
Millsboro, Lewes, Dagsboro, Millville, Henlopen Acres, Cape Henlopen
State Park, Long Neck, Ocean View, Frankford, South Bethany and Dewey
Beach.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Protecting yourself from immediate threats to life and safety shall
take priority. Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.
Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
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 3859 7530 3883 7527 3882 7508 3845 7502
3845 7504 3846 7505 3845 7505 3845 7521
FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...2-3 INCHES IN 1 HOUR
$$
Kruzdlo475
WGUS71 KPHI 101223
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
823 AM EDT Fri Jul 10 2020
DEC005-101630-
/O.CON.KPHI.FF.W.0016.000000T0000Z-200710T1630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-
823 AM EDT Fri Jul 10 2020
...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1230 PM EDT FOR
SOUTHEASTERN SUSSEX COUNTY...
At 821 AM EDT, Doppler radar and automated gauges indicated heavy
rain falling across the warned area. Up to three inches of rain have
already fallen.
Another rainband just crossed the warned area with rain rates in the
3.00 to 6.00 inch per hour range.
Tidal gauges along Rehoboth Bay and Indian River Bay indicate tides
are struggling to recede. This will likely impede rainfall runoff.
Between the rainfall and tides, portions of Route 1 will likely see
flooding.
HAZARD...Life threatening flash flooding. Heavy rain producing flash
flooding.
SOURCE...Radar and automated gauges.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
Some locations that could experience flooding include...
Millsboro, Lewes, Dagsboro, Millville, Henlopen Acres, Cape Henlopen
State Park, Long Neck, Ocean View, Frankford, South Bethany and Dewey
Beach.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Protecting yourself from immediate threats to life and safety shall
take priority. Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.
Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
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 3859 7530 3883 7527 3882 7508 3845 7502
3845 7504 3846 7505 3845 7505 3845 7521
FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...2-3 INCHES IN 1 HOUR
$$
Kruzdlo758
WGUS71 KPHI 101624
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
1224 PM EDT Fri Jul 10 2020
DEC005-101632-
/O.EXP.KPHI.FF.W.0016.000000T0000Z-200710T1630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-
1224 PM EDT Fri Jul 10 2020
...THE FLASH FLOOD WARNING FOR SOUTHEASTERN SUSSEX COUNTY WILL EXPIRE
AT 1230 PM EDT...
Rain continues to fall across portions of Sussex County. Between 3
and 5 inches of rain have fallen since early this morning. While the
threat for new flash flooding has ended, ongoing flooding will
likely persist through mid afternoon. This Flash Flood Warning will
be allowed to expire and will be replace with a Flood Warning.
LAT...LON 3859 7530 3883 7527 3882 7508 3845 7502
3845 7504 3846 7505 3845 7505 3845 7521
$$
KruzdloThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 10, 9:21 AM EDT | Areal Flood Advisory | PHI | Kent, New Castle, Sussex | 8 hr |
| Jul 10, 11:02 AM EDT | Areal Flood Advisory | PHI | New Castle | 4 hr |
| Jul 10, 12:22 PM EDT | Areal Flood Warning | PHI | Sussex | 3 hr |
| Jul 10, 12:56 PM EDT | Flash Flood Warning | PHI | New Castle | 4 hr |
| Jul 10, 3:38 PM EDT | River Flood Warning | PHI | New Castle | 4 hr |
| Jul 10, 4:48 PM EDT | Areal Flood Warning | PHI | New Castle | 4 hr |
Nearby
Flash Flood Warnings in Delaware, 2020Every flash flood warning in 2020
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.