Alert archive / Maryland / Flash Flood Warnings in 2021
Flash Flood Warning 25, NWS Baltimore/Washington
NWS Baltimore/Washington issued this flash flood warning at Jul 12, 2021, 7:55 PM EDT for Cecil County, Harford County, Maryland. It was in force for 77 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Jul 12, 2021, 7:55 PM EDT (23:55 UTC)
- Expired
- Jul 12, 2021, 9:12 PM EDT
- In force
- 77 min
- Issued by
- NWS Baltimore/Washington
- Area
- Storm-based polygon
- Flood severity
- None
Counties Cecil County, MD, Harford County, MD
The radar
The Dover AFB radar (KDOX), 113 km from the middle of the area, began a volume at 23:57 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 12:00Z, 11.9 hours before the alert went out and 125 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
- 974 J/kg
- Mixed-layer CIN
- -83 J/kg
- Mixed-layer LCL
- 724 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 10 m²/s²
- 0-3 km storm-relative helicity
- 53 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.8
The text
As transmitted.
634
WGUS51 KLWX 122355
FFWLWX
MDC015-025-130545-
/O.NEW.KLWX.FF.W.0025.210712T2355Z-210713T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Baltimore MD/Washington DC
755 PM EDT Mon Jul 12 2021
The National Weather Service in Sterling Virginia has issued a
* Flash Flood Warning for...
Western Cecil County in northeastern Maryland...
North Central Harford County in northern Maryland...
* Until 145 AM EDT.
* At 755 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 2.5 and 3.5 inches of
rain have fallen. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
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...
Bel Air North... Octoraro...
Darlington...
This includes the following Flood Prone Roads:
Sandy Hook Road near Deer Creek...
Darlington Road at Deer Creek Road...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3959 7634 3962 7632 3966 7625 3967 7623
3968 7620 3967 7620 3967 7618 3968 7614
3967 7610 3961 7615 3958 7625 3955 7631
3957 7634
FLASH FLOOD...RADAR INDICATED
$$
LEE1 follow-up statement
759
WGUS71 KLWX 130112
FFSLWX
Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
912 PM EDT Mon Jul 12 2021
MDC015-025-130122-
/O.CAN.KLWX.FF.W.0025.000000T0000Z-210713T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cecil MD-Harford MD-
912 PM EDT Mon Jul 12 2021
...FLASH FLOOD WARNING IS CANCELLED FOR WESTERN CECIL AND NORTH
CENTRAL HARFORD COUNTIES...
Flash flooding is no longer expected to pose a threat. A flood
warning remains in effect. Please continue to heed road closures.
LAT...LON 3959 7634 3962 7632 3966 7625 3967 7623
3968 7620 3967 7620 3967 7618 3968 7614
3967 7610 3961 7615 3958 7625 3955 7631
3957 7634
$$
RCMThe office that day
Everything else NWS Baltimore/Washington issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 11, 8:28 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 47 min |
| Jul 12, 2:43 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 47 min |
| Jul 12, 3:15 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 22 min |
| Jul 12, 6:28 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 47 min |
| Jul 12, 7:01 PM EDT | Severe Thunderstorm Warning | LWX | Cecil | 20 min |
| Jul 12, 7:08 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Cecil, Harford | 52 min |
| Jul 12, 7:23 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Cecil, Harford | 52 min |
| Jul 12, 7:40 PM EDT | Areal Flood Warning | LWX | Baltimore, Cecil, Harford | 6 hr |
Nearby
Flash Flood Warnings in Maryland, 2021Every flash flood warning in 2021
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.