Strong surface heating due to sunshine combined with localized winds to produce a dust devil.
Every event with a place to put it. Tap one for its entry below.
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.
The episode as NWS LWX wrote it up.
Strong surface heating due to sunshine combined with localized winds to produce a dust devil.
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 Jul 19, 1:32 PM EST, 1 hour 28 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 232 PM EDT SUN JUL 19 2009 .SYNOPSIS... HIGH PRESSURE OVER THE MID ATLANTIC TONIGHT WHILE AN UPPER LEVEL LOW PRESSURE TROUGH DEVELOPS OVER THE MIDWEST STATES. THE UPPER TROUGH WILL RESULT IN UNSETTLED WEATHER FOR THE FIRST HALF OF NEXT WEEK. && .NEAR TERM /TONIGHT/... SURFACE HIGH DRIFTS NORTH TOWARDS NEW ENGLAND WHILE LOW PRESSURE SLOWLY ORGANIZES OVER NORTH CAROLINA TONIGHT. ACROSS THE MID ATLANTIC...WEAK ELY FLOW ESTABLISHES ITSELF...WHICH WILL BEGIN TO DRAW ATLANTIC MOISTURE INLAND...INCREASING DEWPOINTS THROUGH THE OVERNIGHT. BAY BREEZE FRONT SLOWLY PUSHING INLAND THIS EVENING...AS EVIDENCED BY VISIBLE SATELLITE AND SURFACE OBS. BY BREEZE SHOULD WORK TOWARD THE BLUE RIDGE THIS EVENING. THIS FEATURE WILL HAVE LITTLE EFFECT OTHER THAN A BRIEF ENHANCED SELY WIND THIS EVENING AND SOME ENHANCED CU...MAINLY EAST OF I-95. OVERNIGHT LOWS A BIT CHALLENGING...AS NIGHT BEGINS WITH PRIME RADIATIONAL COOLING THAT WILL BE INCREASINGLY HINDERED BY MOIST EASTERLY FLOW FROM THE ATLANTIC. WENT CLOSER TO THE COOLER MET FOR GUIDANCE...THINKING THAT TEMPERATURES WILL FALL RAPIDLY BEFORE 6Z...THEN LEVEL OFF FOR THE REMAINDER OF THE OVERNIGHT. THIS PUTS MONDAY MORNING MINIMA NEAR 5 DEGREES BELOW CLIMATOLOGICAL MEANS...BUT A BIT WARMER THAN SUNDAY MORNINGS LOWS...WHICH SET RECORD LOWS AT BOTH KMRB AND KBWI. MOST AREAS WILL STAY DRY OVERNIGHT...THOUGH CLOUDS WILL BE ON THE INCREASE. OROGRAPHIC FEATURES IN THE SW CWA WILL WARRANT SLIGHT POPS OVERNIGHT. && .SHORT TERM /MONDAY/... UPPER TROF TO THE WEST CONTINUES TO DEEPEN AND BECOME CLOSED OVER THE OHIO VALLEY MONDAY. ON THE EAST SIDE OF THE TROF...UPPER JET WILL STREAM NORTH THROUGH THE EAST COAST. EAST WINDS AT THE SURFACE WILL INCREASE A LITTLE...INCREASING DEWPOINTS SUBSTANTIALLY. SEVERAL MINOR VORT MAXES WILL WORK NORTHWARD UP THE EAST SIDE OF THE APPALACHIANS...AND THESE COMBINED WITH TERRAIN ENHANCED LIFT AT THE LOW LEVELS WILL BRING SHOWERS AND ISOLATED THUNDERSTORMS TO THE AREA...WITH POPS RANGING FROM LIKELY IN THE SW TO SLIGHT CHANCE N/E OF BALTIMORE METRO. MODEST WAA DOMINATES MONDAY...BUT WITH ABUNDANT CLOUD COVER AND SCATTERED PRECIP...DAILY MAXIMA WILL BE SIMILAR TO THOSE OVER THE WEEKEND...WITH L80S DOMINANT. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... THE MAIN WX FEATURE THAT CATCHES MY EYE ISNT ON THE E CST...BUT WHEN LOOKING AT THE GFS HEMISHPERIC VIEW THE STRENGTH AND PERSISTENCE OF THE RDG W OF THE ROCKIES IS REALLY IMPRESSIVE. 4 CORNERS HIGH LOOKS FIRMLY ESTABLISHED W/ 500 HGT OF ALMOST 595 DM. W/ THE RDG BECOMING SO STRONG IN THE W THIS WL HELP TO KEEP HELP TO KEEP THE U.S. E OF THE MS RVR IN A TROF. AS HAS BEEN STATED IN XTND DSCNS OVR THE PAST FEW DAYS E CST WL BE CAUGHT ON THE ERN SIDE OF THE TROF WHIEL THE SUB TROP HIGH RMNS OFFSHORE. THIS WL KEEP MID ATLC IN A MOIST FLOW. IT IS HARD TO PICK OUT THE FEATURES WIHCH WL DIRECTLY BE RESPONSIBLE FOR GNR8NG PCPN DURG THE XTND. MEX NRMCL GUIDNC GOING W/ 70/80 POP FOR TUE FOR MUCH OF THE CWA...WHILE SREF QPF GUIDNC IMPLIES THE HIGHEST CHCS WL BE SE OF OUR CWA. ON THU 06Z GFS WAS DVLP A WK WV OF LOW PRES WHICH COULD MOVE UP THE CST...BUT THIS IS MISSING IN THE 12Z RUN...NOR IS IT DEPICTED BY THE ECMWF OR GEM. AS OF NOW WELL STICK W/ THE ONGOING FCST OF CHC RW/ISOLD TRW DURG MUCH OF THE WEEK AHD W/ HIGHEST POPS IN THE ERN PART OF THE CWA. DAYTIME HIGHS DURG WK AHD IN 80S W/ LOWS IN THE 60S. AS MDNGT SHIFT POINTED OUT PROLONGED CHANNELING UP THE BAY LKLY TO PRODUCE ABV NRML TIDAL LVLS DURG THE 2ND HALF OF THE WK. && .AVIATION /TNGT THROUGH FRIDAY/... VFR CONDITIONS WITH LIGHT WINDS TONIGHT. INCREASING CLOUDS TOMORROW...BUT CEILINGS FOR THE MOST PART REMAINING ABOVE 5KFT THROUGH MID AFTERNOON. CHANCE POPS FOR KMRB AND KCHO AFTER 18Z OR SO...EXPANDING TO ALL AREA TAF SITES AFTER 22Z. WINDS MONDAY REMAIN LIGHT AND MOSTLY OUT OF THE EAST. ALTHO XTSNV CLD CVR DURG WK AHD OUTSIDE OF SHRA/TSTMS WX SHOULD BE VFR DURG THE XTND PD. CIGS PSBLY DROPPING INTO MVFR RANGE DEPENDING ON HOW THE WORK WKS WX PLAYS OUT. && .MARINE... SOUTHEAST WINDS HAVE ESTABLISHED THEMSELVES THIS AFTERNOON OVER THE WATERS OF THE TIDAL POTOMAC AND MARYLAND CHESAPEAKE...THOUGH SPEED REMAINS UNDER 10 KTS. THESE CONDITIONS SHOULD CONTINUE OVERNIGHT AND THROUGH MONDAY...WITH OCCASIONAL GUSTS TO 15 KTS MONDAY AFTERNOON. DRY CONDITIONS OVERNIGHT AND MUCH OF THE DAY MONDAY...WITH INCREASING CLOUDS. ISOLATED SHOWERS EXPECTED LATE TOMORROW AFTERNOON AND INTO THE EVENING. WINDS XPCTD TO RMN BLO SCA VALUES DURG THE XTND PD. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && PRODUCTS...SBK/WOODY
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 241 PM EDT SUN JUL 19 2009 ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057- 201000- CHESAPEAKE BAY NORTH OF POOLES ISLAND MD- CHESAPEAKE BAY FROM POOLES ISLAND TO SANDY POINT MD- CHESAPEAKE BAY FROM SANDY POINT TO NORTH BEACH MD- CHESAPEAKE BAY FROM NORTH BEACH TO DRUM POINT MD- CHESAPEAKE BAY FROM DRUM POINT MD TO SMITH POINT VA- TIDAL POTOMAC FROM KEY BRIDGE TO INDIAN HEAD MD- TIDAL POTOMAC FROM INDIAN HEAD TO COBB ISLAND MD- TIDAL POTOMAC FROM COBB ISLAND MD TO SMITH POINT VA- PATAPSCO RIVER INCLUDING BALTIMORE HARBOR- CHESTER RIVER TO QUEENSTOWN MD-EASTERN BAY- CHOPTANK RIVER TO CAMBRIDGE MD AND THE LITTLE CHOPTANK RIVER- PATUXENT RIVER TO BROOMES ISLAND MD- TANGIER SOUND AND THE INLAND WATERS SURROUNDING BLOODSWORTH ISLAND-DISTRICT OF COLUMBIA-NORTHERN BALTIMORE-HARFORD- SOUTHERN BALTIMORE-PRINCE GEORGES-ANNE ARUNDEL-CHARLES-ST. MARYS- CALVERT-PRINCE WILLIAM/MANASSAS/MANASSAS PARK-FAIRFAX- ARLINGTON/FALLS CHURCH/ALEXANDRIA-STAFFORD-SPOTSYLVANIA- KING GEORGE- 241 PM EDT SUN JUL 19 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE MARYLAND PORTION OF THE CHESAPEAKE BAY...TIDAL POTOMAC RIVER...AND ADJACENT COUNTIES IN CENTRAL MARYLAND AND NORTHERN VIRGINIA AS WELL AS THE DISTRICT OF COLUMBIA. .DAY ONE...THIS AFTERNOON AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY DUE TO PERSISTENT SOUTHERLY WINDS...WATER LEVELS MAY RISE ABOVE NORMAL IN THE CHESAPEAKE BAY AND TIDAL POTOMAC RIVER FOR THE SECOND HALF OF THE WEEK. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED THROUGH TONIGHT. MDZ003>005-009-010-501-502-VAZ021-025>031-036>042-050-051- WVZ050>055-501>504-201000- WASHINGTON-FREDERICK MD-CARROLL-MONTGOMERY-HOWARD- EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY-HIGHLAND- AUGUSTA-ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE- NELSON-ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-FAUQUIER-LOUDOUN- ORANGE-CULPEPER-HAMPSHIRE-MORGAN-BERKELEY-JEFFERSON-PENDLETON- HARDY-WESTERN GRANT-EASTERN GRANT-WESTERN MINERAL-EASTERN MINERAL- 241 PM EDT SUN JUL 19 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN WEST VIRGINIA... NORTHERN AND CENTRAL VIRGINIA...AND CENTRAL AND WESTERN MARYLAND WITH THE EXCEPTION OF GARRETT COUNTY. .DAY ONE...THIS AFTERNOON AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED THROUGH TONIGHT.
The national radar mosaic for the moment the first event began.
1 dust devil. Local standard time, as filed.
Patio furniture was damaged and a woman was injured in Valley Lee due to a dust devil.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Maryland in 2009Every state in 2009This day in weather historyWarnings in Maryland, July 2009
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: 190844.