Flash Flooding and Hail in Maryland, June 22 to 23, 2001

Name: Flash Flooding and Hail in Maryland, June 22 to 23, 2001
Start: 2001-06-22T15:00
End: 2001-06-23T00:30
Location: Maryland

June 22 to 23, 2001 · NWS LWX · 13 events in 7 counties and zones

Where it happened

Every event with a place to put it; 11 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $211,000
Crop damage: None recorded
Events: 13

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS LWX wrote it up.

During the afternoon of the 22nd, numerous showers and thunderstorms developed just east of the Appalachian Mountains and moved very slowly east across northwest and north central Maryland through the pre-dawn hours of the 23rd. These storms contained very heavy rainfall, frequent lightning, and occasionally produced high winds and large hail. In Allegany County, the heaviest rain fell across the southwestern portion of the county. Several basements were flooded in Rawlings and parts of Route 220 were covered in water. Heavy rainfall downed a tree onto a power line in Frostburg. In Washington County, heavy downpours downed trees in the western portion of the county. In Frederick County, nickel sized hail was reported on Route 40 west of Frederick. In Frederick pea sized hail fell and a wind gust of 50 MPH was estimated. Trees were downed by high winds in the Putman Road area 5 miles north-northwest of Frederick. Pea sized hail was reported in Poolesville. A spotter in Braddock Heights reported 2 inches of rainfall in 20 minutes. At Point of Rocks, the railroad crossing on Route 28 was flooded. A three story mansion was struck by lightning and the resulting fire caused $300,000 damage. Another lightning fire in Kemptown caused $20,000 damage. In Carroll County, some roads and low lying area were flooded in the Westminster and Melrose areas. Rainfall totals included 4.05 inches in Manchester and 2.41 inches in Westminster. Gunpowder River overflowed west of Linesboro. Rushing water downed power lines in the northern part of the county. Lightning started a garage on fire and $70,000 damage was reported. In Montgomery County, heavy rainfall caused roads to flood so quickly that three people had to be rescued from their cars. The hardest hit areas were in the vicinity of Olney, Wheaton, and Brighton Dam. Numerous roads had to be closed until the water subsided including Brighton Dam Road, Emory Lane, Muncaster Mill Road, Route 97, and West Willow Road. Route 97 was closed after the Hawlings River overflowed just north of Brookville. Rainfall totals included 5.00 inches in Brookville, 4.72 inches in Olney, 4.67 inches in Aspen Hill, 4.00 inches at Brighton Dam, 3.27 inches in Layhill, 2.68 inches in Potomac, and 2.46 inches in Bethesda. In Poolesville, a man was burned on his face as he tried to put out a lightning fire in a three story mansion. A garage with several vintage cars also caught fire after lightning hit the structure. In Howard County, high water closed Brighton Dam Road, Guilford Drive, Route 108, Route 216, Sheppards Lane, Green Bridge Road, Woodstream Drive, Old Frederick Road, Carrs Mill Road, Bethany Lane, Cedar Lane, Route 29, and Old Columbia Road. North Trotter Road was washed out by the Middle Patuxent River. Several people had to be rescued from their vehicles after roads quickly flooded. A mudslide closed Marriottsville Road in Ellicott City. Rainfall reports included an estimate of 5 inches just northeast of Clarkesville, 4.10 inches in Clarkesville, and 3.30 inches in Cooksville. In Harford County, heavy rain fell mainly across the far eastern portion of the county. Up to 7 inches of rainfall was reported at the Conowingo Dam on the Susquehanna River. Minor flooding was reported near Havre de Grace.

What forecasters said that day

The local office's own words before the first event, 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 the first event at Jun 22, 2:40 PM EST, 20 minutes earlier.

Area forecast discussion, Jun 22, 2:40 PM EST, 20 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
340 PM EDT FRI JUN 22 2001

AT 18Z...SEVERAL TSTMS MAINLY BLUE RIDGE W PRODUCING VERY HEAVY
RAINFALL...HAIL...AND POSSIBLY STRONG WINDS.  STORMS SEEM TO
REDEVELOP OVER SAME AREAS WHICH ADDS TO FLOODING THREAT. TSTMS AND
SHRA WILL CONTINUE THROUGH NIGHT DUE TO APPROACHING FRONTAL
BDRY...STRONG UL DIVERGENCE...PLENTY OF VVEL AT 700 AND 500MB IN
ADDITION TO 850MB LOW MOVING OVHD.  WILL HAVE 80 POPS CWA WIDE. WILL
ALSO CONTINUE FLASH FLOOD WATCH UNTIL 4 AM FOR BLUE RIDGE W AND CHO
AREA. EXPECT HAIL/WIND THREAT TO DIMINISH A FEW HOURS AFT SUNSET DUE
TO LOSS OF DAYTIME HEATING BUT HVY RAIN WILL PROBABLY CONTINUE TO BE
A PROBLEM BECAUSE PRECIP H20 VALUES REMAIN AROUND 1.75 IN. MOST CWA
UNDER SVR TSTM WATCH THRU 7PM.

FRONT REACHES NW CWA BY MIDDAY BUT DOESNT REACH FAR SE CWA UNTIL
SUN MORNING. RELATIVELY DRIER AIR WILL COME IN BEHIND FRONT AND SHUD
GIVE US A RAIN FREE PERIOD FROM W TO E SUN MORN THRU MON AFT. UL LOW
CUTS OFF OVER SE US AND RETROGRADES A BIT MON INTO TUE. THIS TURNS
WINDS E FOR A TIME MON AND BRINGS IN SOME RH OFF THE WATER AND ALSO
SPINS SOME WEAK IMPULSES FROM S TO N THRU CWA. THIS WILL GIVE ATMOS
SOME RH AND LIFT TO WORK WITH...ESPECIALLY MON AFT...TO CREATE
WIDELY SCT SHRA/-TSRA. ATMOS WONT CHANGE SIG TUE SO WILL KEEP 30
POP FOR AFT CONVECTION IN FCST. HI PRES OVER THE OCEAN STARTS TO
INFLUENCE MID ATLANTIC WEATHER WED THRU FRI SO WILL FCST DRY COND.

REGARDING TEMPS...THOUGHT FWC LOW TEMPS WERE TOO COLD NEXT FEW NIGHT
DUE TO ELEVATED DEW PTS. STAYED NEAR GUIDANCE REST OF FCST.

FCSTID = 36
DCA   70  80  65  82 /  80  70  50  30
BWI   70  80  65  82 /  80  70  50  30
MRB   68  77  64  83 /  80  60  40  20
IAD   69  79  62  82 /  80  70  50  30
CHO   69  79  65  81 /  80  70  50  30
HGR   66  75  63  80 /  80  60  40  20
NHK   71  80  68  81 /  80  70  50  30

.LWX...
DC...NONE.
MD...FLASH FLOOD WATCH THRU 400 AM FOR ZONES MDZ002>003.

VA...FLASH FLOOD WATCH THRU 400 AM FOR ZONES VAZ021...VAZ025>031...
VAZ036>040...VAZ050>051.

WV...FLASH FLOOD WATCH THRU 400 AM FOR ZONES WVZ048>055.

MMARGRAF

In the hours before

Special weather statement, Jun 22, 10:25 AM EST, 4 hours 35 minutes before

DCZ001-MDZ002>007-009>011-013-014-016>018-VAZ021-025>031-036>042-
050>057-WVZ048>055-222100-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BALTIMORE-WASHINGTON
1125 AM EDT FRI JUN 22 2001

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING ACROSS THE EASTERN WEST VIRGINIA PANHANDLE...NORTHERN
VIRGINIA...THE SHENANDOAH VALLEY...MUCH OF MARYLAND WEST OF THE
CHESAPEAKE BAY AND THE DISTRICT OF COLUMBIA.

WARM...MOIST AND UNSTABLE AIR COMBINED WITH A COLD FRONT APPROACHING
FROM THE WEST WILL RESULT IN THE DEVELOPMENT OF THUNDERSTORMS ACROSS
THE REGION THIS AFTERNOON AND EVENING.  SOME THUNDERSTORMS COULD
CONTAIN DAMAGING WINDS IN EXCESS OF 60 MPH AND HAIL UP TO AN INCH IN
DIAMETER. IN ADDITION...HEAVY RAINFALL FROM THUNDERSTORMS MAY RESULT
IN LOCALIZED FLOODING...ESPECIALLY IN LOW LYING AND POOR DRAINAGE
AREAS. HEAVY DOWNPOURS PRODUCE PONDING OF WATER ON ROADWAYS AND CAN
CAUSE SMALL STREAMS AND CREEKS TO OVERFLOW THEIR BANKS.

REMEMBER...ALL THUNDERSTORMS PRODUCE LIGHTNING. LIGHTNING CAN OCCUR
WITHOUT WARNING WELL IN ADVANCE OF RAINFALL ASSOCIATED WITH A
THUNDERSTORM. IF YOU CAN HEAR THUNDER...TAKE SHELTER IMMEDIATELY.

STAY TUNED TO NOAA WEATHER RADIO OR OTHER LOCAL MEDIA FOR UPDATES ON
THE SEVERE WEATHER THREAT AND POSSIBLE WATCHES AND WARNINGS THIS
AFTERNOON AND TONIGHT.

MMARGRAF

The radar

The Sterling radar (KLWX), 75 km away, was scanning. The volume nearest the first event began at 20:23 UTC.

Open the radar archive at this moment

Event by event

4 flash flood, 4 lightning, 3 heavy rain, 1 hail, 1 thunderstorm wind. Local standard time, as filed.

Heavy Rain, Washington

When: June 22, 3:00 PM EST to 5:00 PM EST
Where: Washington County, Countywide
Reported by: TRAINED SPOTTER
Coordinates: 39.604, -77.814 (the zone’s center; the record gives no point)

Heavy Rain, Frederick

When: June 22, 3:15 PM EST to 5:15 PM EST
Where: Frederick County, Countywide
Reported by: TRAINED SPOTTER
Coordinates: 39.472, -77.398 (the zone’s center; the record gives no point)

Hail, Frederick

When: June 22, 3:25 PM EST
Where: Frederick County, Frederick
Measured: 0.88 in hail
Reported by: TRAINED SPOTTER
Coordinates: 39.417, -77.417

Nickel sized hail fell.

Thunderstorm Wind, Frederick

When: June 22, 4:10 PM EST
Where: Frederick County, 5 mi NW of Frederick
Property damage: $500
Reported by: LAW ENFORCEMENT
Coordinates: 39.470, -77.483

Trees were downed in the Putman Road area.

Flash Flood, Allegany

When: June 22, 4:30 PM EST to 6:30 PM EST
Where: Allegany County, Southwest Portion
Reported by: LAW ENFORCEMENT
Coordinates: 39.622, -78.699 (the zone’s center; the record gives no point)

Flooding was reported in Rawlings and on Route 220.

Lightning, Frederick

When: June 22, 5:15 PM EST
Where: Frederick County, Kemptown
Property damage: $20,000
Reported by: NEWSPAPER
Coordinates: 39.472, -77.398 (the zone’s center; the record gives no point)

A piano shop was damaged by a lightning fire.

Lightning, Montgomery

When: June 22, 6:00 PM EST
Where: Montgomery County, Poolesville
Property damage: $120,000
Reported by: NEWSPAPER
Coordinates: 39.136, -77.204 (the zone’s center; the record gives no point)

A lightning fire damaged a home and one person was injured while trying to extinguish the flames.

Flash Flood, Montgomery

When: June 22, 6:00 PM EST to 11:59 PM EST
Where: Montgomery County, Countywide
Reported by: LAW ENFORCEMENT
Coordinates: 39.136, -77.204 (the zone’s center; the record gives no point)

Numerous roads were flooded and impassable and 3 swift water rescues were reported.

Lightning, Carroll

When: June 22, 7:00 PM EST
Where: Carroll County, Mt Airy
Reported by: NEWSPAPER
Coordinates: 39.563, -77.022 (the zone’s center; the record gives no point)

Lightning started a fire at a garage which contained several vintage cars.

Heavy Rain, Harford

When: June 22, 7:00 PM EST to 8:30 PM EST
Where: Harford County, East Portion
Reported by: TRAINED SPOTTER
Coordinates: 39.536, -76.299 (the zone’s center; the record gives no point)

Flash Flood, Carroll

When: June 22, 8:30 PM EST to 11:00 PM EST
Where: Carroll County, Countywide
Reported by: LAW ENFORCEMENT
Coordinates: 39.563, -77.022 (the zone’s center; the record gives no point)

A few roads and low lying areas were flooded and rushing water downed trees on Gillis Falls Road.

Flash Flood, Howard

When: June 22, 9:00 PM EST to 11:59 PM EST
Where: Howard County, Countywide
Reported by: FIRE DEPT/RESCUE SQUAD
Coordinates: 39.251, -76.931 (the zone’s center; the record gives no point)

Roads rapidly flooded and several motorists had to be rescued from their vehicles.

Lightning, Carroll

When: June 23, 12:30 AM EST
Where: Carroll County, Westminster
Property damage: $70,000
Reported by: NEWSPAPER
Coordinates: 39.563, -77.022 (the zone’s center; the record gives no point)

A garage apartment was damaged by a lightning fire.

What these are

Heavy Rain: Rainfall totals unusual for the place and season that did not produce a flood.
Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
Lightning: A lightning strike that killed, injured or caused damage.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Maryland in 2001 Every state in 2001 This day in weather history Warnings in Maryland, June 2001

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5254300, 5254301, 5254303, 5254302, 5254304, 5254305, 5254306, 5254307, 5254753, 5254754, 5254755, 5254756, 5254757.