Alert archive / Maryland / Flash Flood Warnings in 2021

Flash Flood Warning 29, NWS Baltimore/Washington

July 25, 2021Cecil County, Maryland

NWS Baltimore/Washington issued this flash flood warning at Jul 25, 2021, 11:50 PM EDT for Cecil County, Maryland. It was in force for 3 hr. 1 report 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 25, 2021, 11:50 PM EDT (03:50 UTC)
Expired: Jul 26, 2021, 2:53 AM EDT
In force: 3 hr
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Cecil County, MD

The radar

The Dover AFB radar (KDOX), 109 km from the middle of the area, began a volume at 03:49 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 25, 11:56 PM EDT	FLASH FLOOD	2 Ssw Farmington, MD	NUMEROUS VEHICHLES STRANDED IN HIGH WATER IN THE AREA OF RED TOAD ROAD AND PRINCIPIO 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, 3.8 hours before the alert went out and 141 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1389 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 1315 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 45 m²/s²
0-3 km storm-relative helicity: 98 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 3.3

Open this sounding in Storm Lab

The text

As transmitted.

746 
WGUS51 KLWX 260350
FFWLWX
MDC015-260700-
/O.NEW.KLWX.FF.W.0029.210726T0350Z-210726T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Baltimore MD/Washington DC
1150 PM EDT Sun Jul 25 2021

The National Weather Service in Sterling Virginia has issued a

* Flash Flood Warning for...
  Cecil County in northeastern Maryland...

* Until 300 AM EDT.

* At 1150 PM EDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  4 and 6 inches of rain have fallen. Additional rainfall amounts of 
  1 to 3 inches are possible in the warned area. Flash flooding is 
  ongoing or expected to begin shortly.

  HAZARD...Life threatening flash flooding. Thunderstorms
           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 will experience flash flooding include...
  Rising Sun...                      Farmington...
  West Nottingham...

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 3971 7612 3971 7608 3971 7604 3967 7599
      3964 7597 3962 7604 3964 7608 3967 7611

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

BRO

2 follow-up statements

760 
WGUS71 KLWX 260548
FFSLWX

Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
148 AM EDT Mon Jul 26 2021

MDC015-260700-
/O.CON.KLWX.FF.W.0029.000000T0000Z-210726T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cecil MD-
148 AM EDT Mon Jul 26 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 3 AM EDT EARLY THIS 
MORNING FOR CECIL COUNTY...

At 148 AM EDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 5 
and 7 inches of rain have fallen. Flash flooding is ongoing or 
expected to begin shortly.

HAZARD...Life threatening flash flooding. Thunderstorms 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 will experience flash flooding include...
Rising Sun...                      Farmington...
West Nottingham...

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 3971 7612 3971 7608 3971 7604 3967 7599
      3964 7597 3962 7604 3964 7608 3967 7611

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

BRO

886 
WGUS71 KLWX 260653
FFSLWX

Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
253 AM EDT Mon Jul 26 2021

MDC015-260703-
/O.CAN.KLWX.FF.W.0029.000000T0000Z-210726T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cecil MD-
253 AM EDT Mon Jul 26 2021

...FLASH FLOOD WARNING IS CANCELLED FOR CECIL COUNTY...

The heavy rain has ended. An areal flood warning does remain in 
effect with emergency personnel reporting ongoing flooding issues. 
Please continue to heed remaining road closures.

LAT...LON 3971 7612 3971 7608 3971 7604 3967 7599
      3964 7597 3962 7604 3964 7608 3967 7611

$$

BRO

The office that day

Everything else NWS Baltimore/Washington issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 25, 11:15 PM EDT	Areal Flood Warning	LWX	Cecil, Harford	6 hr
Jul 26, 12:18 AM EDT	Areal Flood Warning	LWX	Cecil, Harford	5 hr
Jul 26, 5:19 AM EDT	Areal Flood Warning	LWX	Cecil	4 hr
Jul 26, 2:52 PM EDT	Severe Thunderstorm Warning	LWX	Allegany, Washington	38 min
Jul 26, 3:21 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Calvert	24 min
Jul 26, 6:46 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Howard, Montgomery, Prince George's	44 min
Jul 26, 7:07 PM EDT	Severe Thunderstorm Warning	LWX	Montgomery, Prince George's	23 min
Jul 26, 7:30 PM EDT	Severe Thunderstorm Warning	LWX	Prince George's	14 min
Jul 26, 7:36 PM EDT	Severe Thunderstorm Warning	LWX	Prince George's	24 min

Nearby

Flash Flood Warnings in Maryland, 2021 Every 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.