Alert archive / Maryland / Flash Flood Warnings in 2017

Flash Flood Warning 13, NWS Baltimore/Washington

July 4, 2017Allegany County, Maryland; Mineral County, West Virginia

NWS Baltimore/Washington issued this flash flood warning at Jul 4, 2017, 3:51 PM EDT for Allegany County, Maryland; Mineral County, West Virginia. It was in force for 3 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
Jul 4, 2017, 3:51 PM EDT (19:51 UTC)
Expired
Jul 4, 2017, 6:45 PM EDT
In force
3 hr
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon
Flood severity
None

Counties Allegany County, MD, Mineral County, WV

The radar

The Sterling radar (KLWX), 134 km from the middle of the area, began a volume at 19:51 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

Pittsburgh, PA (KAGC), launched 12:00Z, 7.9 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-pSkew-T log-p diagram, Pittsburgh, PA at 12:00Z on 2017-07-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Pittsburgh, PA at 12:00Z on 2017-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -28 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1092 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
-28 m²/s²
0-3 km storm-relative helicity
6 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

311 
WGUS51 KLWX 041951
FFWLWX
MDC001-WVC057-042245-
/O.NEW.KLWX.FF.W.0013.170704T1951Z-170704T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Baltimore MD/Washington DC
351 PM EDT TUE JUL 4 2017

The National Weather Service in Sterling Virginia has issued a

* Flash Flood Warning for...
  Northwestern Allegany County in western Maryland...
  Northeastern Mineral County in eastern West Virginia...

* Until 645 PM EDT

* At 350 PM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the area. Up to two inches of rain have already 
  fallen, and additional rainfall is expected. Flash flooding is 
  expected to begin shortly.

* Some locations that may experience flooding include...
  Cumberland, La Vale and Ridgeley. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Keep children away from storm drains, culverts, creeks and streams.
Water levels can rise rapidly and sweep children away.

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 3969 7875 3965 7873 3963 7877 3967 7880

$$

LEE
1 follow-up statement
987 
WGUS71 KLWX 042027
FFSLWX

Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
427 PM EDT TUE JUL 4 2017

MDC001-WVC057-042036-
/O.CAN.KLWX.FF.W.0013.000000T0000Z-170704T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Allegany MD-Mineral WV-
427 PM EDT TUE JUL 4 2017

...THE FLASH FLOOD WARNING FOR NORTHWESTERN ALLEGANY AND NORTHEASTERN
MINERAL COUNTIES IS CANCELLED...

The heavy rain has ended. Flash flooding is no longer expected. Be
alert for remaining standing water and continue to follow road
closures.  

LAT...LON 3969 7875 3965 7873 3963 7877 3967 7880

$$

LEE

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 4, 4:45 PM EDTSevere Thunderstorm WarningLWXFrederick, Washington45 min
Jul 4, 5:31 PM EDTSevere Thunderstorm WarningLWXFrederick31 min
Jul 4, 6:07 PM EDTSevere Thunderstorm WarningLWXCarroll, Frederick, Howard, Montgomery38 min

Nearby

Flash Flood Warnings in Maryland, 2017Flash Flood Warnings in West Virginia, 2017Every flash flood warning in 2017

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.