Alert archive / Maryland / Flash Flood Watches in 2018

Flash Flood Watch 13, NWS Baltimore/Washington

July 21, 20188 counties in Virginia; 13 counties in Maryland; Jefferson County, West Virginia

NWS Baltimore/Washington issued this flash flood watch at Jul 21, 2018, 5:05 AM EDT for 8 counties in Virginia; 13 counties in Maryland; Jefferson County, West Virginia. It took effect at Jul 21, 2018, 11:00 AM EDT. It was in force for 15 hr.

The area

The counties it named.

The facts

Issued: Jul 21, 2018, 5:05 AM EDT (09:05 UTC)
In effect from: Jul 21, 2018, 11:00 AM EDT
Expired: Jul 22, 2018, 2:00 AM EDT
In force: 15 hr
Issued by: NWS Baltimore/Washington
Flood severity: None

All 22 counties

Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Carroll County, MD, Charles County, MD, City of Baltimore, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Saint Mary's County, MD, Washington County, MD, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, Fairfax County, VA, King George County, VA, Loudoun County, VA, Stafford County, VA, Jefferson County, WV

The radar

The Sterling radar (KLWX), 37 km from the middle of the area, began a volume at 09:08 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 forecasters said that day

The local office's own words before this flash flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Baltimore/Washington wrote its last area forecast discussion before this flash flood watch went out at Jul 21, 3:58 AM EDT, 1 hour 7 minutes earlier.

Area forecast discussion, Jul 21, 3:58 AM EDT, 1 hour 7 minutes before

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Hazardous weather outlook, Jul 20, 10:44 AM EDT, 18 hours 21 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 21, 2:46 AM EDT	Coastal Flood Advisory	LWX	Arlington, King George, City of Alexandria, City of Falls Church	4 days
Jul 21, 9:39 AM EDT	Gale Warning	LWX		13 hr
Jul 21, 2:44 PM EDT	Small Craft Advisory	LWX		4 days
Jul 21, 2:48 PM EDT	Areal Flood Warning	LWX	Spotsylvania, Stafford, City of Fredericksburg	6 hr
Jul 21, 4:41 PM EDT	Areal Flood Warning	LWX	Fairfax, Loudoun, Prince William, City of Fairfax, City of Manassas, City of Manassas Park	27 hr
Jul 21, 5:14 PM EDT	Areal Flood Warning	LWX	Fauquier	18 hr
Jul 21, 5:20 PM EDT	Areal Flood Warning	LWX	Arlington, City of Alexandria, City of Falls Church	23 hr
Jul 21, 5:35 PM EDT	Areal Flood Warning	LWX	King George	27 hr
Jul 21, 6:30 PM EDT	Areal Flood Warning	LWX	Loudoun	38 hr
Jul 21, 7:23 PM EDT	Flash Flood Warning	LWX	Fairfax, Prince William, City of Fairfax, City of Manassas Park	3 hr
Jul 21, 7:36 PM EDT	Flash Flood Warning	LWX	Charles	3 hr

Nearby

Flash Flood Watches in Maryland, 2018 Flash Flood Watches in Virginia, 2018 Flash Flood Watches in West Virginia, 2018 Every flash flood watch in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive.