A southwest flow ushered in plenty of moisture around high pressure over the Southeast Coast. The heat combined with the moisture to cause moderate amounts of instability.
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.
A southwest flow ushered in plenty of moisture around high pressure over the Southeast Coast. The heat combined with the moisture to cause moderate amounts of instability. A few thunderstorms developed, and some became severe due to the unstable atmosphere.
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 May 16, 2:17 PM EST, 54 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 317 PM EDT SAT MAY 16 2015 .SYNOPSIS... A BACK DOOR COLD FRONT WILL SLIDE SOUTH TOWARD THE AREA SUNDAY NIGHT AND STALL ACROSS THE AREA MONDAY BEFORE DISSIPATING. A STRONGER COLD FRONT WILL MOVE IN FROM THE WEST TUESDAY. COOL AND DRY HIGH PRESSURE WILL FOLLOW FOR THE MIDDLE OF NEXT WEEK. LOW PRESSURE WILL PASS SOUTH OF THE REGION TOWARD THE END OF THE WEEK. && .NEAR TERM /THROUGH SUNDAY/... HIGH PRESSURE WILL REMAIN OFF THE MIDDLE ATLANTIC COAST THROUGH SUNDAY. THE RETURN FLOW AROUND THE RIDGE WILL HELP PUMP A WARM AND HUMID AIRMASS INTO THE FORECAST AREA OVER THE NEXT COUPLE OF DAYS. FOR THE REMAINDER OF TODAY...INSTABILITY WILL BE ADEQUATE BUT SHEAR WILL BE MINIMAL THIS AFTERNOON AND EVENING. SHOWERS AND THUNDERSTORMS WILL DEVELOP FROM WEST TO EAST THIS AFTERNOON...IMPACTING THE WASHINGTON DC AND BALTIMORE METRO AREAS AFTER 20Z THEN CLEARING THE FORECAST AREA AROUND 03Z. SOME OF THE STORMS WILL BE CAPABLE OF PRODUCING BRIEF HEAVY DOWNPOURS...SMALL HAIL AND GUSTY WINDS BUT THREAT FOR SEVERE IS LOW GIVEN INADEQUATE SHEAR. THE SHOWER ACTIVITY WILL DIMINISH OVERNIGHT AND LOWS WILL DROP BACK INTO THE 60S IN MOST LOCATIONS...EXCEPT LOW 70S IN THE METRO CENTERS. SOME PATCHY FOG COULD DEVELOP OVERNIGHT. BACKDOOR FRONTAL BOUNDARY WILL SLIDE SOUTH AND WHEN COMBINED WITH MORE INSTABILITY WILL LEAD TO THE DEVELOPMENT OF ADDITIONAL SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON AND EVENING. MOST OF THE STORMS WILL REMAIN BELOW SEVERE CRITERIA BUT A FEW OF THE STORMS COULD ONCE AGAIN PRODUCE BRIEF HEAVY DOWNPOURS...SMALL HAIL AND GUSTY WINDS. AFTERNOON HIGH TEMPERATURES WILL LIKELY REACH THE LOWER TO MIDDLE 80S IN MOST LOCATIONS. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... SHOWERS AND A COUPLE OF THUNDERSTORMS WILL AFFECT THE REGION SUNDAY NIGHT THROUGH MONDAY NIGHT AS A FRONT BECOMES STALLED ACROSS THE REGION. PIECES OF ENERGY WILL RIDE UP AND OVER A MID-LEVEL RIDGE OF HIGH PRESSURE OVER THE CAROLINAS. THIS ENERGY WILL BE THE NEEDED LIFT FOR SHOWER AND THUNDERSTORM ACTIVITY. LOW TEMPERATURES SUNDAY NIGHT AND MONDAY NIGHT WILL BE ABOUT 10 TO 15 DEGREES ABOVE NORMAL. HIGH TEMPERATURES MONDAY WILL BE ABOUT 10 DEGREES ABOVE NORMAL. && .LONG TERM /TUESDAY THROUGH SATURDAY/... THE SHOWER AND THUNDERSTORM THREAT LINGERS TUESDAY INTO TUESDAY EVENING AHEAD OF AN APPROACHING COLD FRONT AT THE SURFACE AS THE RIDGE OF HIGH PRESSURE BREAKS DOWN OVER THE SOUTHEAST U.S. HIGHS TUESDAY WILL BE A FEW DEGREES COOLER BUT STILL ABOVE NORMAL FOR THIS TIME IN MAY. BEHIND THE FRONTAL PASSAGE TUESDAY NIGHT...HIGH PRESSURE WILL BUILD IN FROM THE WEST...USHERING IN COOLER AND DRIER AIR ON A GUSTY WEST TO NORTHWEST BREEZE. LOWS WILL BOTTOM OUT IN THE MIDDLE 50S...ABOUT 10 DEGREES COOLER THAN PREVIOUS NIGHTS. DRY CONDITIONS WILL PERSIST WEDNESDAY THROUGH THURSDAY AS HIGH PRESSURE BUILDS IN ACROSS THE REGION. HIGHS WILL BE IN THE LOWER TO MIDDLE 70S WEDNESDAY AND THURSDAY...WHILE WEDNESDAY NIGHT LOWS WILL BOTTOM OUT IN THE MIDDLE 40S OVER THE POTOMAC HIGHLANDS TO THE LOWER 50S ALONG THE TIDAL POTOMAC. ONCE THE HIGH PRESSURE MOVES TO THE COAST THURSDAY NIGHT...A SOUTHERLY RETURN FLOW WILL DEVELOP AND USHER BACK IN MORE HUMID AIR FROM THE SOUTH. THERE IS A SLIGHT CHANCE OF RAIN SHOWERS THURSDAY NIGHT...MAINLY IN THE WEST AND SOUTH...AS WEAK UPPER LEVEL ENERGY PIVOTS ACROSS THE EASTERN OHIO VALLEY. A SLIGHT CHANCE OF SHOWERS LINGERS ACROSS LOWER SOUTHERN MARYLAND FRIDAY AS A WEAK TROUGH OF LOW PRESSURE MOVES TO THE EAST COAST. HIGHS IN THE MIDDLE 70S. A WEAK AREA OF HIGH PRESSURE WILL BUILD IN BEHIND THE TROUGH OF LOW PRESSURE SATURDAY...BRINGING A BRIEF ROUND OF COOLER AND DRIER AIR. HIGHS SATURDAY MIDDLE TO UPPER 70S. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL IMPACT THE TERMINALS THE REMAINDER OF THIS AFTERNOON INTO THE FIRST PART OF TONIGHT. SOME OF THE STORMS WILL BE CAPABLE OF PRODUCING SMALL HAIL..BRIEF HEAVY DOWNPOURS AND GUSTY WINDS. THE ACTIVITY WILL DIMINISH EARLY TONIGHT. VFR EXPECTED OVERNIGHT EXCEPT SOME PATCHY FOG ESPECIALLY AT KCHO. ADDITIONAL SHOWERS AND THUNDERSTORMS EXPECTED SUNDAY AFTERNOON AND EVENING. MAINLY MVFR CONDITIONS SUNDAY NIGHT THROUGH TUESDAY WITH EXCEPTION TO IFR CONDITIONS IN SHOWER AND THUNDERSTORM ACTIVITY EACH PERIOD. BEST CHANCE FOR IFR CONDITIONS MONDAY AFTERNOON AND TUESDAY AFTERNOON. WINDS WILL BE LIGHT AND VARIABLE EXCEPT IN ANY GUSTY THUNDERSTORMS. VFR CONDITIONS TUESDAY NIGHT AND WEDNESDAY WITH HIGH PRESSURE BUILDING INTO THE REGION. WINDS WILL SHIFT TO THE NORTHWEST AND INCREASE TUESDAY NIGHT INTO WEDNESDAY MORNING. && .MARINE... WINDS HAVE REMAINED BELOW SCA ALL OF TODAY. A FEW GUSTY THUNDERSTORMS EXPECTED THROUGH THE FIRST PART OF TONIGHT WHICH COULD PROMPT A FEW SMW'S TO BE ISSUED. ADDITIONAL SHOWER AND THUNDERSTORM CHANCES EXPECTED SUNDAY AFTERNOON AND EVENING. NO MARINE HAZARDS SUNDAY NIGHT THROUGH TUESDAY. SMALL CRAFT ADVISORY CONDITIONS POSSIBLE TUESDAY NIGHT INTO EARLY WEDNESDAY. && .TIDES/COASTAL FLOODING... A SOUTHERLY FLOW WILL CONTINUE THROUGH THE WEEKEND. THIS WILL LIKELY CAUSE ANOMALIES TO INCREASE A BIT...BUT THE WIND MAY BE JUST WEST OF SOUTH...LIKELY KEEPING WATER LEVELS BELOW MINOR FLOODING THRESHOLDS DURING THIS TIME. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && SYNOPSIS...KRW NEAR TERM...KRW SHORT TERM...KLW LONG TERM...KLW AVIATION...KLW/KRW MARINE...KLW/KRW TIDES/COASTAL FLOODING...KRW
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 200 PM EDT SAT MAY 16 2015 ANZ530>543-DCZ001-MDZ011-013-014-016>018-508-VAZ052>057-171600- 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-SOUTHERN BALTIMORE-PRINCE GEORGES- ANNE ARUNDEL-CHARLES-ST. MARYS-CALVERT-SOUTHEAST HARFORD- PRINCE WILLIAM/MANASSAS/MANASSAS PARK-FAIRFAX- ARLINGTON/FALLS CHURCH/ALEXANDRIA-STAFFORD-SPOTSYLVANIA- KING GEORGE- 200 PM EDT SAT MAY 16 2015 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...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. MDZ003>006-501>507-VAZ025>031-036>040-050-051-501>508-WVZ050>053- 055-501>506-171600- WASHINGTON-FREDERICK MD-CARROLL-NORTHERN BALTIMORE- EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY- NORTHWEST MONTGOMERY-CENTRAL AND SOUTHEASTERN MONTGOMERY- NORTHWEST HOWARD-CENTRAL AND SOUTHEAST HOWARD-NORTHWEST HARFORD- AUGUSTA-ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE- NELSON-ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-ORANGE-CULPEPER- NORTHERN FAUQUIER-SOUTHERN FAUQUIER-WESTERN HIGHLAND- EASTERN HIGHLAND-WESTERN LOUDOUN-EASTERN LOUDOUN- NORTHERN VA BLUE RIDGE-CENTRAL VA BLUE RIDGE-HAMPSHIRE-MORGAN- BERKELEY-JEFFERSON-HARDY-WESTERN GRANT-EASTERN GRANT- WESTERN MINERAL-EASTERN MINERAL-WESTERN PENDLETON- EASTERN PENDLETON- 200 PM EDT SAT MAY 16 2015 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...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
341 PM EDT SAT MAY 16 2015
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0329 PM HAIL 2 SE LYDIA 38.31N 78.47W
05/16/2015 M1.25 INCH GREENE VA TRAINED SPOTTER
&&
EVENT NUMBER LWX1500125
DHThe national radar mosaic for the moment the first event began.
2 thunderstorm wind. Local standard time, as filed.
Large tree limbs were down along Route 9 near Wiltshire Road.
Large tree limbs were down along Highway 340 at Chestnut Hill Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in West Virginia in 2015Every state in 2015This day in weather historyWarnings in West Virginia, May 2015
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: 575843, 575844.