Heavy Rain in Maryland, August 12, 2001

Name: Heavy Rain in Maryland, August 12, 2001
Start: 2001-08-12T07:00
End: 2001-08-12T20:00
Location: Maryland

August 12, 2001 · NWS LWX · 1 event in 1 county or zone

Showers and thunderstorms with heavy rainfall moved across St. Mary's County between 8 AM and 11 AM and again between 6 PM and 9 PM EDT on the 12th.

Where it happened

Every event with a place to put it; 1 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

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The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 1

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.

Showers and thunderstorms with heavy rainfall moved across St. Mary's County between 8 AM and 11 AM and again between 6 PM and 9 PM EDT on the 12th. Rainfall totals from both events included 3.02 inches at Patuxent River Naval Station and 2.68 inches in Hollywood.

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 Aug 12, 2:36 AM EST, 4 hours 24 minutes earlier.

Area forecast discussion, Aug 12, 2:36 AM EST, 4 hours 24 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
336 AM EDT SUN AUG 12 2001

WL ISSUE FFA FOR ENTIRE FA FOR TDY AND TNGT. SHRAS AND TSRAS
PRODUCED WIDESPRD FLOODING FM HOWARD COUNTY MD WWD TO NRN SHEN VLLY
YEST. LATEST FFG FM YEST MORNING SHOWED 1 HR AMTS AVGG ARND 2.5
INCHES. EXPECT GUIDANCE WL BE LOWER TODAY DUE TO YEST/S HVY RAFL.

ANOTHER ROUND OF HVY PCPN WL OCCUR OVR FA TDY AND TNGT. MOIST
UNSTABLE AMS WL CONT OVR THE RGN. WL HV MULTIPLE LIFTING MECHS OVR
THE AREA AS A STREAM OF WK SHRTWVS CONTS TO MOV NE THRU THE RGN. IN
ADDITION...THERE WL BE BOUNDARIES OVR AREA FM YEST/S CONVECTION.

MDLS PROG H85 WNDS TO INCR TO 30 KTS THIS AFTN WHICH WL CONTRIB TO
LIFT.

PCP H20/S FCST TO CONT ON ORDER OF 1.5 TO 2.0 INCHES THRU TNGT BFR
DROPPING OFF A BIT ON MON. H85 DWPTS WERE 15 DEG C OVR THE AREA AT
00Z AND WL CONT TO BE HIGH INTO TNGT.

TROF WL SETTLE OVR E COAST STATES DURING THE PD. ON MON...A CDFNT WL
MOV INTO THE TROF...BUT MEAN RH WL BE ON THE DECREASE. WL CONT CHC
OF SHRAS/TSRAS FOR MON AND LV MON NGT P/C AS HIGH RH WL BE E OF FA.

PREFER FWC TEMPS AND POPS OVR MAV NUMBERS.

EXTENDED PD LOOKS DRY W/NEAR NORMAL TEMPS.

THANKS FOR COORD AKQ AND RNK.

.LWX...
DC...FLASH FLOOD WATCH FOR SUNDAY AND SUNDAY NIGHT FOR ZONE DCZ001.

MD...FLASH FLOOD WATCH FOR SUNDAY AND SUNDAY NIGHT FOR ZONES
MDZ002>007...MDZ009>011...MDZ013>014...MDZ016>018.

VA...FLASH FLOOD WATCH FOR SUNDAY AND SUNDAY NIGHT FOR ZONES
VAZ021...VAZ025>031...VAZ036>042...VAZ050>057.

WV...FLASH FLOOD WATCH FOR SUNDAY AND SUNDAY NIGHT FOR ZONES
WVZ048>055.

ARTHUR

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

1 heavy rain. Local standard time, as filed.

Heavy Rain, St. Mary'S

When: August 12, 7:00 AM EST to 8:00 PM EST
Where: St. Mary'S County, Countywide
Reported by: TRAINED SPOTTER
Coordinates: 38.216, -76.529 (the zone’s center; the record gives no point)

What these are

Heavy Rain: Rainfall totals unusual for the place and season that did not produce a flood.

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, August 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: 5265440.