Alert archive / Maryland / Flash Flood Warnings in 2021
Flash Flood Warning 76, NWS Baltimore/Washington
NWS Baltimore/Washington issued this flash flood warning at Sep 23, 2021, 4:17 AM EDT for Frederick County, Maryland. It was in force for 3 hr. 20 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
- Sep 23, 2021, 4:17 AM EDT (08:17 UTC)
- Expired
- Sep 23, 2021, 7:15 AM EDT
- In force
- 3 hr
- Issued by
- NWS Baltimore/Washington
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
County Frederick County, MD
The radar
The Sterling radar (KLWX), 67 km from the middle of the area, began a volume at 08:17 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 |
|---|---|---|---|
| Sep 23, 4:30 AM EDT | FLOOD | 4 Sw Keysville, MD | ROAD CLOSURE DUE TO FLOODING IN THE ROCKY RIDGE AREA |
| Sep 23, 4:48 AM EDT | FLOOD | 1 E Woodsboro, MD | HILL ROAD BETWEEN COPPERMINE ROAD AND RENNER ROAD IS CLOSED DUE TO HIGH WATER. |
| Sep 23, 5:16 AM EDT | FLASH FLOOD | 2 Nne Woodsboro, MD | MD-194 AT CASH SMITH ROAD CLOSED DUE TO HIGH WATER. |
| Sep 23, 5:30 AM EDT | FLASH FLOOD | Libertytown, MD | SWIFT WATER RESUCE NEAR THE 8900 BLOCK OF JONES ROAD IN LIBERTYTOWN. |
| Sep 23, 5:39 AM EDT | FLASH FLOOD | 2 N Libertytown, MD | MD-75 AT COPPERMINE ROAD CLOSED DUE TO HIGH WATER. |
| Sep 23, 6:02 AM EDT | FLOOD | 1 E Woodsboro, MD | HILL ROAD WAS CLOSED DUE TO FLOODING BETWEEN COPPERMINE ROAD AND RENNER ROAD. |
| Sep 23, 6:02 AM EDT | FLOOD | 1 Sw Middleburg, MD | CLAYBAUGH ROAD WAS CLOSED DUE TO FLOODING AT LITTLE PIPE CREEK. |
| Sep 23, 6:02 AM EDT | FLOOD | 3 N Woodsboro, MD | HINEY ROAD WAS CLOSED DUE TO FLOODING BETWEEN LEGORE ROAD AND HAUGHS CHURCH ROAD. |
| Sep 23, 6:03 AM EDT | FLOOD | Libertytown, MD | JONES ROAD WAS BLOCKED BY HIGH WATER NEAR SOUTH STREET. |
| Sep 23, 6:07 AM EDT | FLOOD | Libertytown, MD | HIGH WATER BLOCKS MD-26 MAIN STREET AT TRAMMELS ALLEY. |
| Sep 23, 6:29 AM EDT | FLASH FLOOD | 2 Ene Walkersville, MD | SWIFT WATER RESCUE IN THE 9900 BLOCK OF DAYSVILLE ROAD AT CABBAGE RUN. |
| Sep 23, 6:41 AM EDT | FLOOD | 1 Ene Walkersville, MD | DEVILBISS BRIDGE ROAD WAS BLOCKED BY HIGH WATER NEAR MD-194 WOODSBORO PIKE. |
| Sep 23, 7:03 AM EDT | FLOOD | 1 Ese Walkersville, MD | STAUFFER ROAD WAS CLOSED DUE TO FLOODING NEAR WATER STREET ROAD. |
| Sep 23, 7:03 AM EDT | FLOOD | 1 Nnw Mount Pleasant, MD | CRUM ROAD WAS CLOSED DUE TO FLOODING NEAR STAUFFER ROAD. |
| Sep 23, 7:03 AM EDT | FLOOD | 2 Nne Mount Pleasant, MD | WATER STREET ROAD WAS CLOSED DUE TO FLOODING BY HARP ROAD. |
| Sep 23, 7:03 AM EDT | FLOOD | 2 S Middleburg, MD | THE 11800 BLOCK OF BEAVER DAM ROAD WAS BLOCKED BY HIGH WATER. |
| Sep 23, 7:03 AM EDT | FLOOD | 3 Ene New Market, MD | DETRICK ROAD WAS CLOSED DUE TO FLOODING NEAR SOUTH FORK BENS BRANCH. |
| Sep 23, 7:03 AM EDT | FLOOD | 3 Ene New Market, MD | LIME PLANT ROAD WAS CLOSED DUE TO FLOODING AT NORTH FORK BENS BRANCH. |
| Sep 23, 7:03 AM EDT | FLOOD | 3 E New Market, MD | JESSE SMITH ROAD WAS CLOSED DUE TO FLOODING AT SOUTH FORK BENS BRANCH. |
| Sep 23, 7:03 AM EDT | FLOOD | 3 Nne New Market, MD | GAS HOUSE PIKE WAS CLOSED DUE TO FLOODING NEAR CENTRAL CHURCH ROAD. |
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 00:00Z, 8.3 hours before the alert went out and 68 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
- 100 J/kg
- Mixed-layer CIN
- -17 J/kg
- Mixed-layer LCL
- 652 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 161 m²/s²
- 0-3 km storm-relative helicity
- 199 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
382
WGUS51 KLWX 230817
FFWLWX
MDC021-231115-
/O.NEW.KLWX.FF.W.0076.210923T0817Z-210923T1115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Baltimore MD/Washington DC
417 AM EDT Thu Sep 23 2021
The National Weather Service in Sterling Virginia has issued a
* Flash Flood Warning for...
Northeastern Frederick County in north central Maryland...
* Until 715 AM EDT.
* At 417 AM EDT, Doppler radar indicated heavy rain across the
warned area. Between 1.5 and 2.5 inches of rain have fallen.
Additional rainfall amounts of 1 to 2 inches are possible in the
warned area. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Life threatening flash flooding. Heavy rain producing
flash flooding.
SOURCE...Radar.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
* Some locations that will experience flash flooding include...
Walkersville... New Market...
Discovery-Spring Garden... Linganore-Bartonsville...
Green Valley... Woodsboro...
Libertytown... Monrovia...
Mount Pleasant... New Midway...
Ladiesburg... Ijamsville...
Detour... Rocky Ridge...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 3934 7736 3962 7734 3961 7730 3960 7729
3961 7729 3961 7727 3959 7726 3960 7726
3959 7724 3959 7723 3958 7722 3957 7722
3958 7721 3958 7720 3957 7719 3934 7722
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
ADS2 follow-up statements
643
WGUS71 KLWX 230943
FFSLWX
Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
543 AM EDT Thu Sep 23 2021
MDC021-231115-
/O.CON.KLWX.FF.W.0076.000000T0000Z-210923T1115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Frederick MD-
543 AM EDT Thu Sep 23 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 AM EDT THIS
MORNING FOR NORTHEASTERN FREDERICK COUNTY IN NORTH CENTRAL
MARYLAND...
At 543 AM EDT, local law enforcement reported flooding due to heavy
rain across the warned area. Between 2 and 3.5 inches of rain have
fallen. Additional rainfall amounts of 1 to 2 inches are possible in
the warned area. Flash flooding is already occurring.
HAZARD...Life threatening flash flooding. Heavy rain producing
flash flooding.
SOURCE...Law enforcement reported flooding in the Rocky Ridge and
Libertytown areas.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
Some locations that will experience flash flooding include...
Walkersville... New Market...
Discovery-Spring Garden... Linganore-Bartonsville...
Green Valley... Woodsboro...
Libertytown... Monrovia...
Mount Pleasant... New Midway...
Ladiesburg... Ijamsville...
Detour... Rocky Ridge...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 3934 7736 3962 7734 3961 7730 3960 7729
3961 7729 3961 7727 3959 7726 3960 7726
3959 7724 3959 7723 3958 7722 3957 7722
3958 7721 3958 7720 3957 7719 3934 7722
FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
ADS493
WGUS71 KLWX 231111
FFSLWX
Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
711 AM EDT Thu Sep 23 2021
MDC021-231121-
/O.EXP.KLWX.FF.W.0076.000000T0000Z-210923T1115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Frederick MD-
711 AM EDT Thu Sep 23 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 715 AM EDT THIS MORNING FOR
NORTHEASTERN FREDERICK COUNTY IN NORTH CENTRAL MARYLAND...
The heaviest rain has ended, and rapid rises of water are no longer
expected. However, moderate rain continues, which will prolong
ongoing flooding. A Flood Warning remains in effect. Please continue
to heed road closures.
A Flash Flood Watch remains in effect until 200 PM EDT Thursday for
portions of DC, Maryland and northern Virginia.
LAT...LON 3934 7736 3962 7734 3961 7730 3960 7729
3961 7729 3961 7727 3959 7726 3960 7726
3959 7724 3959 7723 3958 7722 3957 7722
3958 7721 3958 7720 3957 7719 3934 7722
$$
ADSThe office that day
Everything else NWS Baltimore/Washington issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 23, 12:25 AM EDT | Coastal Flood Advisory | LWX | Charles | 8 hr |
| Sep 23, 2:02 AM EDT | Areal Flood Warning | LWX | Frederick, Washington | 10 hr |
| Sep 23, 2:34 AM EDT | Flash Flood Warning | LWX | Frederick, Washington | 3 hr |
| Sep 23, 3:47 AM EDT | Areal Flood Warning | LWX | Montgomery | 12 hr |
| Sep 23, 3:53 AM EDT | Areal Flood Warning | LWX | Carroll, Frederick | 17 hr |
| Sep 23, 4:41 AM EDT | Areal Flood Warning | LWX | Howard, Montgomery | 9 hr |
| Sep 23, 5:35 AM EDT | Areal Flood Warning | LWX | Carroll, Frederick | 6 hr |
| Sep 23, 7:08 AM EDT | River Flood Warning | LWX | Montgomery | 16 hr |
| Sep 23, 7:56 AM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 22 min |
| Sep 23, 8:04 AM EDT | Areal Flood Warning | LWX | Anne Arundel, Baltimore, Harford, Howard, Montgomery, Prince George's and 1 more | 10 hr |
| Sep 23, 9:02 AM EDT | Areal Flood Warning | LWX | Cecil | 9 hr |
| Sep 23, 9:27 AM EDT | Severe Thunderstorm Warning | LWX | Cecil, Harford | 78 min |
| Sep 23, 12:11 PM EDT | Areal Flood Warning | LWX | Frederick | 5 hr |
| Sep 23, 1:18 PM EDT | River Flood Warning | LWX | Frederick | 25 hr |
| Sep 23, 2:15 PM EDT | Coastal Flood Advisory | LWX | Charles | 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.