Alert archive / Delaware / Flash Flood Warnings in 2026
Flash Flood Warning 144, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 28, 2026, 1:11 PM EDT for Sussex County, Delaware. It was in force for 4 hr. 17 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
- Aug 28, 2026, 1:11 PM EDT (17:11 UTC)
- Expired
- Aug 28, 2026, 5:15 PM EDT
- In force
- 4 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), 22 km from the middle of the area, began a volume at 17:14 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 |
|---|---|---|---|
| Aug 28, 1:25 PM EDT | RAIN 1.19 | 2 Ese Nassau, DE | Mesonet station FW0960 Rehoboth Beach. |
| Aug 28, 1:30 PM EDT | FLASH FLOOD | Milton, DE | Front Street was closed between Walnut Street and Cave Neck Road due to flooding. |
| Aug 28, 1:30 PM EDT | RAIN 1.63 | 1 Se Nassau, DE | Mesonet station EW0496 Rehoboth Beach. |
| Aug 28, 1:54 PM EDT | RAIN 1.3 | 1 Sw Delaware Coastal A, DE | ASOS station KGED Georgetown. |
| Aug 28, 2:19 PM EDT | RAIN 1.24 | 4 Nnw Georgetown, DE | Mesonet station REDD1 Redden. |
| Aug 28, 2:24 PM EDT | FLASH FLOOD | Belltown, DE | Report from mPING: Street/road flooding; Street/road closed; Vehicles stranded. |
| Aug 28, 2:50 PM EDT | RAIN 2.34 | 1 Se Nassau, DE | Mesonet station EW0496 Rehoboth Beach. |
| Aug 28, 2:54 PM EDT | RAIN 1.3 | 1 Sw Delaware Coastal A, DE | ASOS station KGED Georgetown. |
| Aug 28, 2:55 PM EDT | RAIN 2.05 | 2 Nne Harbeson, DE | Mesonet station GW5368 MILTON. |
| Aug 28, 2:56 PM EDT | RAIN 1.7 | 2 Ese Nassau, DE | Mesonet station FW0960 Rehoboth Beach. |
| Aug 28, 2:57 PM EDT | RAIN 1.36 | 1 Wsw Belltown, DE | Mesonet station GW5802 LEWES. |
| Aug 28, 2:59 PM EDT | RAIN 2.02 | Rehoboth Beach, DE | Mesonet station RBBPH Rehoboth Beach. |
| Aug 28, 3:00 PM EDT | RAIN 1.87 | 3 Wsw Nassau, DE | Mesonet station EW9904 Milton. |
| Aug 28, 4:54 PM EDT | RAIN 1.64 | 1 Sw Delaware Coastal A, DE | ASOS station KGED Georgetown. |
| Aug 28, 5:19 PM EDT | RAIN 2.07 | 4 Nnw Georgetown, DE | Mesonet station REDD1 Redden. |
| Aug 28, 5:25 PM EDT | RAIN 2.62 | 1 Se Nassau, DE | Mesonet station EW0496 Rehoboth Beach. |
| Aug 28, 5:25 PM EDT | RAIN 3 | 2 Nne Harbeson, DE | Mesonet station GW5368 MILTON. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 5.2 hours before the alert went out and 192 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
- 213 J/kg
- Mixed-layer CIN
- -175 J/kg
- Mixed-layer LCL
- 1015 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 1 m²/s²
- 0-3 km storm-relative helicity
- 70 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.4
The text
As transmitted.
749
WGUS51 KPHI 281711
FFWPHI
DEC005-282115-
/O.NEW.KPHI.FF.W.0144.260828T1711Z-260828T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
111 PM EDT Fri Aug 28 2026
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Eastern Sussex County in southern Delaware...
* Until 515 PM EDT.
* At 111 PM EDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Between
1 and 2 inches of rain have fallen. The expected rainfall rate is 1
to 2 inches in 1 hour. Additional rainfall amounts of 1 to 2 inches
are possible in the warned area. Flash flooding is ongoing or
expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar and automated gauges.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Georgetown, Millsboro, Lewes, Milton, Dagsboro, Millville, Henlopen
Acres, Cape Henlopen State Park, Long Neck, Ocean View, Frankford
and South Bethany.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3892 7531 3894 7530 3881 7516 3882 7510
3881 7509 3881 7508 3880 7508 3862 7505
3852 7504 3849 7528 3867 7554
FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR
$$
PHI3 follow-up statements
827
WGUS71 KPHI 281740
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
140 PM EDT Fri Aug 28 2026
DEC005-282115-
/O.CON.KPHI.FF.W.0144.000000T0000Z-260828T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-
140 PM EDT Fri Aug 28 2026
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM EDT THIS
AFTERNOON FOR EASTERN SUSSEX COUNTY...
At 140 PM EDT, the public reported thunderstorms producing heavy rain
across the warned area. Between 1 and 2 inches of rain have fallen.
The expected rainfall rate is 1 to 2 inches in 1 hour. Additional
rainfall amounts of 1 to 2 inches are possible in the warned area.
Flash flooding is already occurring in Dewey Beach.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Public reported.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
Some locations that will experience flash flooding include...
Georgetown, Millsboro, Lewes, Milton, Dagsboro, Millville, Henlopen
Acres, Cape Henlopen State Park, Long Neck, Ocean View, Frankford
and South Bethany.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3892 7531 3894 7530 3881 7516 3882 7510
3881 7509 3881 7508 3880 7508 3862 7505
3852 7504 3849 7528 3867 7554
FLASH FLOOD...OBSERVED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR
$$
PHI649
WGUS71 KPHI 281840
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
240 PM EDT Fri Aug 28 2026
DEC005-282115-
/O.CON.KPHI.FF.W.0144.000000T0000Z-260828T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-
240 PM EDT Fri Aug 28 2026
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM EDT THIS
AFTERNOON FOR EASTERN SUSSEX COUNTY...
At 240 PM EDT, the public reported thunderstorms producing heavy rain
across the warned area. Between 1.5 and 3 inches of rain have fallen.
The expected rainfall rate is 1 to 2 inches in 1 hour. Additional
rainfall amounts up to 1 inch are possible in the warned area. Flash
flooding is already occurring.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Public reported.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
Some locations that will experience flash flooding include...
Georgetown, Millsboro, Lewes, Milton, Dagsboro, Millville, Henlopen
Acres, Cape Henlopen State Park, Long Neck, Ocean View, Frankford
and South Bethany.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3892 7531 3894 7530 3881 7516 3882 7510
3881 7509 3881 7508 3880 7508 3862 7505
3852 7504 3849 7528 3867 7554
FLASH FLOOD...OBSERVED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR
$$
PHI973
WGUS71 KPHI 282105
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
505 PM EDT Fri Aug 28 2026
DEC005-282115-
/O.EXP.KPHI.FF.W.0144.000000T0000Z-260828T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-
505 PM EDT Fri Aug 28 2026
...FLASH FLOOD WARNING WILL EXPIRE AT 515 PM EDT THIS AFTERNOON FOR
EASTERN SUSSEX COUNTY...
The heavy rain has ended. Please continue to heed remaining road
closures.
&&
LAT...LON 3892 7531 3894 7530 3881 7516 3882 7510
3881 7509 3881 7508 3880 7508 3862 7505
3852 7504 3849 7528 3867 7554
$$
PHINearby
Flash Flood Warnings in Delaware, 2026Every flash flood warning in 2026
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.