Alert archive / Delaware / Flash Flood Warnings in 2015
Flash Flood Warning 1, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Apr 20, 2015, 10:34 PM EDT for New Castle County, Delaware. It was in force for 6 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
- Apr 20, 2015, 10:34 PM EDT (02:34 UTC)
- Expired
- Apr 21, 2015, 4:27 AM EDT
- In force
- 6 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
County New Castle County, DE
The radar
The Dover AFB radar (KDOX), 95 km from the middle of the area, began a volume at 02:36 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
Washington/Dulle, VA (KIAD), launched 00:00Z, 2.6 hours before the alert went out and 174 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
- 460 J/kg
- Mixed-layer CIN
- -29 J/kg
- Mixed-layer LCL
- 1835 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km storm-relative helicity
- 176 m²/s²
- 0-3 km storm-relative helicity
- 177 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 3.2
The text
As transmitted, in the capitals the NWS used until 2016.
438
WGUS51 KPHI 210234
FFWPHI
DEC003-210630-
/O.NEW.KPHI.FF.W.0001.150421T0234Z-150421T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1034 PM EDT MON APR 20 2015
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* FLASH FLOOD WARNING FOR...
NEW CASTLE COUNTY IN NORTHERN DELAWARE...
* UNTIL 230 AM EDT
* AT 1032 PM EDT...DOPPLER RADAR INDICATED A THUNDERSTORM PRODUCING
HEAVY RAIN MOVING INTO THE AREA. THIS IS THE SAME PART OF NEW
CASTLE COUNTY THAT RECEIVED HEAVY RAIN EARLIER TODAY.'
* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
WILMINGTON...NEWARK...CARNEYS POINT...ELSMERE...NEW CASTLE...PENNS
GROVE...DELAWARE CITY...NEWPORT...ARDEN...BEAR...WILMINGTON
MANOR...HOCKESSIN...PORT PENN...NORTH STAR...GLASGOW...
TALLEYVILLE...MOUNT PLEASANT...GREENVILLE...PIKE CREEK AND SAINT
GEORGES.
RAINFALL AMOUNTS OF 1 TO 2 INCHES IN AN HOUR ARE POSSIBLE IN
THE WARNED AREA. FLOODING IS LIKELY TO AFFECT THE CHRISTINA RIVER.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING.
&&
LAT...LON 3977 7574 3982 7567 3984 7559 3981 7543
3972 7548 3972 7552 3965 7559 3962 7557
3964 7560 3962 7558 3961 7556 3962 7561
3959 7561 3957 7557 3951 7557 3949 7578
3972 7579
$$2 follow-up statements
440
WGUS51 KPHI 210521
FFWPHI
DEC003-210900-
/O.EXT.KPHI.FF.W.0001.000000T0000Z-150421T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
121 AM EDT TUE APR 21 2015
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS EXTENDED THE
* FLASH FLOOD WARNING FOR...
NEW CASTLE COUNTY IN NORTHERN DELAWARE...
* UNTIL 500 AM EDT
* AT 119 AM EDT...DOPPLER RADAR INDICATED MORE THUNDERSTORMS
PRODUCING HEAVY RAIN ACROSS THE WARNED AREA. FLASH FLOODING
OR POOR DRAINAGE FLOODING WILL LIKELY START AGAIN.
* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
WILMINGTON...NEWARK...CARNEYS POINT...ELSMERE...NEW CASTLE...PENNS
GROVE...DELAWARE CITY...NEWPORT...ARDEN...BEAR...WILMINGTON
MANOR...HOCKESSIN...PORT PENN...NORTH STAR...GLASGOW...
TALLEYVILLE...MOUNT PLEASANT...GREENVILLE...PIKE CREEK AND SAINT
GEORGES.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING.
&&
LAT...LON 3977 7574 3982 7567 3984 7559 3981 7543
3972 7548 3972 7552 3965 7559 3962 7557
3964 7560 3962 7558 3961 7556 3962 7561
3959 7561 3957 7557 3951 7557 3949 7578
3972 7579
$$
TFG588
WGUS71 KPHI 210827
FFSPHI
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
427 AM EDT TUE APR 21 2015
DEC003-210836-
/O.CAN.KPHI.FF.W.0001.000000T0000Z-150421T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE DE-
427 AM EDT TUE APR 21 2015
...THE FLASH FLOOD WARNING FOR NEW CASTLE COUNTY IS CANCELLED...
FLOOD WATERS HAVE RECEDED...AND ARE NO LONGER EXPECTED TO POSE A
THREAT TO LIFE OR PROPERTY. PLEASE CONTINUE TO HEED ANY ROAD
CLOSURES AS THERE IS LEFTOVER PONDING IN SOME POOR DRAINAGE AREAS.
LAT...LON 3977 7574 3982 7567 3984 7559 3981 7543
3972 7548 3972 7552 3965 7559 3962 7557
3964 7560 3962 7558 3961 7556 3962 7561
3959 7561 3957 7557 3951 7557 3949 7578
3972 7579
$$
TFGThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 20, 10:24 PM EDT | Special Weather Statement | PHI | New Castle | 81 min |
| Apr 20, 11:08 PM EDT | Areal Flood Advisory | PHI | Kent, New Castle | 112 min |
Nearby
Flash Flood Warnings in Delaware, 2015Every flash flood warning in 2015
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.