Damaging Winds in Maryland, June 29, 2012

Name: Damaging Winds in Maryland, June 29, 2012
Start: 2012-06-29T22:22
End: 2012-06-29T23:49
Location: Maryland

June 29, 2012 · NWS PHI · 5 events in 5 counties and zones

A well-organized cluster of thunderstorms with a history of producing widespread damaging winds advanced into a hot, unstable airmass over the Mid Atlantic. This derecho produced widespread, significant wind damage from southern New Jersey southward into the Delmarva during the late evening and overnight of the 29th.

Where it happened

Every event with a place to put it. 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: 2
Property damage: $720,000
Crop damage: None recorded
Events: 5

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 PHI wrote it up.

Strong thunderstorm development began across the Midwest and Lower Great Lakes regions during the afternoon of the 29th, with storms initiating across northern Illinois, near Chicago. Strong mid-level winds and an unstable airmass contributed to rapid development as well-organized storms progressed from northern Illinois through Indiana and Ohio. This robust convection continued to track southeastward into an airmass that was even more unstable due to abundant daytime surface heating. Late afternoon temperatures had peaked mainly in the mid to upper 90s with high humidity throughout the Mid Atlantic states, and as the potent thunderstorm cluster progressed from the Great Lakes to the central Appalachians and into the Mid Atlantic by late evening, thunderstorm activity was reinvigorated.

A robust gust front outpaced the main thunderstorm line, producing strong wind gusts as it traveled from the eastern shore of Maryland into Delaware and southern New Jersey. Shortly thereafter, the potent thunderstorm line tracked through the region, with additional damaging wind gusts. One cell in particular around Baltimore, MD experienced rapid intensification and expansion as it raced eastward into northern Delaware and southern New Jersey. This massive cell produced extreme damage throughout Salem, Cumberland, and Atlantic counties in New Jersey. Damage to trees, power lines, and buildings was also significant throughout Delaware and the eastern shore of Maryland. Thunderstorms also dropped hail in several locations, ranging from penny to golf-ball size. Destructive wind gusts, between 65 mph to nearly 90 mph, were measured as this derecho tracked from the Lower Great Lakes to the Mid Atlantic coast.

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 Philadelphia/Mount Holly wrote its last area forecast discussion before the first event at Jun 29, 8:18 PM EST, 2 hours 4 minutes earlier.

Area forecast discussion, Jun 29, 8:18 PM EST, 2 hours 4 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
918 PM EDT FRI JUN 29 2012

.SYNOPSIS...
AN AREA OF HIGH PRESSURE GENERALLY REMAINS SITUATED NEAR THE
SOUTHEASTERN STATES THROUGH NEXT WEEK. MEANWHILE, A WEAK COLD FRONT
WILL MOVE THROUGH LATER SATURDAY, THEN TEND TO STALL TO OUR SOUTH
SUNDAY AND MONDAY. THIS BOUNDARY IS THEN FORECAST TO LIFT
NORTHEASTWARD AS A WARM FRONT TUESDAY INTO WEDNESDAY. THE NEXT COLD
FRONT MOVES THROUGH LATER WEDNESDAY INTO THURSDAY, BEFORE STALLING
ACROSS THE MID ATLANTIC FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
CIRRUS SPILLING OUT FROM A ROBUST MCS HAD MOVED OVER MOST OF THE
AREA THIS EVENING, WHILE CONVECTION FROM IT WAS MOVING THROUGH THE
EASTERN PANHANDLE OF WEST VIRGINIA. NOW THAT THE EVENING HAS WORN
ON, IT BECOMES DIFFICULT TO FORECAST THE COMPLEX TO FALL APART ALL
THAT MUCH BEFORE IT REACHES OUR SOUTHERN ZONES. CAPES AND LI ARE
DROPPING RATHER SLOWLY AND LOWER LEVEL THETA E ADVECTION IS
MAINTAINED BY THE MODELS. WE HAVE GONE WITH SLIGHT CHANCE POPS
FROM NORTHERN DELAWARE INTO SOUTHEASTERN NEW JERSEY AND GRADUATED TO
HIGH CHANCE POPS BY THE TIME WE REACH SOUTHERN DELAWARE AND OUR
SOUTHERN PORTION OF THE MARYLAND EASTERN SHORE. OTHERWISE, A WARM,
MUGGY NIGHT IS IN STORE.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
ANOTHER WARM DAY IS AHEAD FOR SATURDAY WITH MAXIMUM TEMPERATURES
AGAIN REACHING WELL INTO THE 90S FOR MOST LOCATIONS, AND 925MB MODEL
TEMPERATURES SUPPORT THIS. WITH DEWPOINTS IN THE 60S AND PERHAPS LOW
70S FOR A FEW HOURS, WE HAVE MAINTAINED THE HEAT HEADLINES FOR URBAN
PHL AREA. IN ADDITION A WEAK FRONTAL BOUNDARY IS PROGGED TO LINGER
NEAR OR EAST OF OUR AREA DURING SATURDAY AFTERNOON TO EVENING. THE
GFS AND NAM ALSO INDICATED SOME UPPER IMPULSES PASSING OVER THE
REGION. THE TIMING AND PLACEMENT OF ANY DEVELOPING SHWR/T-STORM
ACTIVITY IS A LITTLE UNCERTAIN AT THIS TIME, BUT WITH ENOUGH
INSTABILITY AND THESE TRIGGERS IN MIND, WE MAINTAINED POPS FOR
THUNDER FROM SATURDAY AFTERNOON INTO SATURDAY EVENING. WITH ANY
STORMS THAT DO DEVELOP, THE ENVIRONMENT WOULD SUPPORT STORMS WITH
GUSTY WINDS, AND OUR AREA REMAINS IN A SLIGHT RISK FOR SEVERE WX.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
THE HEAT WAVE WILL CONTINUE ACROSS A GOOD PART OF THE AREA INTO THE
START OF THE NEW WEEK, HOWEVER THE EXCESSIVE HEAT IS ANTICIPATED TO
THROTTLE BACK. IN ADDITION, WE MAY START ON A CONVECTIVELY ACTIVE
NOTE. SYNOPTICALLY, AN ELONGATED RIDGE GENERALLY REMAINS IN PLACE
FROM ABOUT THE CENTRAL PLAINS TO THE SOUTHEASTERN UNITED STATES. A
TROUGH ACROSS EASTERN CANADA AMPLIFIES SOME FOR AWHILE BEFORE
TENDING TO LIFT NORTHEASTWARD AS RIDGING BUILDS FROM THE GREAT LAKES
AND OHIO VALLEY WESTWARD TO THE PLAINS FROM ABOUT WEDNESDAY ON. THIS
SYNOPTIC SETUP MAINTAINS A NORTHWESTERLY FLOW ALOFT ACROSS THE
NORTHEAST AND MID ATLANTIC REGION. OUR SENSIBLE WEATHER WILL REMAIN
HOT AND GENERALLY HUMID THROUGH SUNDAY, BUT THEN A BIT OF COOLING
AND SOMEWHAT LOWERING DEW POINTS IS ANTICIPATED. A WEAK COLD FRONT
THAT ARRIVES TO START LOOKS TO STALL NEAR THE NORTHERN MID ATLANTIC,
THEN LIFTS NORTHEASTWARD AS A WARM FRONT TUESDAY INTO WEDNESDAY. A
SECOND COLD FRONT ARRIVES LATER WEDNESDAY INTO THURSDAY BEFORE IT TO
STALLS FROM THE MID ATLANTIC WESTWARD THROUGH THE OHIO VALLEY. THE
MAIN FORECAST CHALLENGES ARE THE HEAT AND THE CONVECTIVE CHCS. WE
GENERALLY TOOK A MODEL BLEND SATURDAY NIGHT INTO MONDAY, THEN
SWITCHED TO HPC GUIDANCE THEREAFTER WITH SOME TWEAKS BASED ON
ADDITIONAL COLLABORATION. HPC WENT GENERALLY WITH THE ECMWF ENSEMBLE
MEAN.

FOR SATURDAY NIGHT THROUGH SUNDAY, SOME CONVECTION MAY BE ONGOING
TO START AS A SHORT WAVE TROUGH ARRIVES ACROSS THE AREA. THIS
CONVECTION WILL BE TRACKING EAST-SOUTHEASTWARD NEAR THE NORTHERN
PERIPHERY OF THE ELONGATED RIDGE. IN ADDITION, A WEAK FRONTAL
BOUNDARY WILL BE PRESENT. THERE SHOULD BE AMPLE INSTABILITY TO START
SATURDAY NIGHT AS THE BOUNDARY LAYER IS HOT WITH ENOUGH MOISTURE.
THE HOT BOUNDARY LAYER RESULTS IN RATHER STEEP LOW-LEVEL LAPSE
RATES, HOWEVER RELATIVELY STEEP MID LEVEL RATES WILL ALSO AIDE IN
UPDRAFT STRENGTH. THE LOWER LEVELS WILL GRADUALLY STABILIZE AS THE
BOUNDARY LAYER COOLS AND CONVECTION MAY WORK IT OVER.

GIVEN THE POTENTIAL INSTABILITY AND MODEST MID LEVEL FLOW,
CONVECTIVE CLUSTERS OR EVEN A MORE ORGANIZED MCS MAY MOVE ACROSS THE
AREA. THERE IS SOME QUESTION THOUGH OF THE TIMING AS SOME MODEL
GUIDANCE HAS MORE ORGANIZATION DURING THE NIGHT COMPARED TO PRIOR TO
00Z SUNDAY. DESPITE THIS, STORMS THAT ARE ABLE TO DEVELOP AND
SUSTAIN THEMSELVES HAVE THE POTENTIAL TO ORGANIZE INTO A CLUSTER AND
PRODUCE DAMAGING WINDS. EVEN THOUGH THE AIRMASS IS RATHER WARM,
STEEPER LAPSE RATES IN CONJUNCTION WITH POSSIBLE ROBUST UPDRAFTS
COULD LEAD TO SOME SEVERE HAIL. SOME CONVECTION MAY LINGER ON SUNDAY
AS A TROUGH TENDS TO AMPLIFY SOME ACROSS THE NORTHEAST. HOWEVER IF
AN MCS OCCURS SATURDAY NIGHT, THERE MAY BE ENOUGH SUBSIDENCE IN ITS
WAY TO KEEP ADDITIONAL DEVELOPMENT AT BAY FOR MOST OF SUNDAY. WE
WENT WITH CHC POPS TO ALLOW FOR AT LEAST SCATTERED SHOWERS AND
THUNDERSTORMS ESPECIALLY SATURDAY NIGHT AND SUNDAY MORNING. WE WILL
CONTINUE TO HIGHLIGHT THE STRONG TO SEVERE CONVECTIVE POTENTIAL IN
THE HAZARDOUS WEATHER OUTLOOK.

THE HEAT WILL STILL BE GOING DURING THIS TIME FRAME, HOWEVER DEW
POINTS MAY BE LOWERING ENOUGH TO KEEP THE HEAT INDICES IN CHECK.
ALSO DUE TO SOME COOLING ALOFT, THE HIGHS SHOULD BE A LITTLE LOWER
SUNDAY. AS A RESULT, WE WILL JUST MAINTAIN THE EXCESSIVE HEAT
WARNING AS IS FOR THE URBANIZED AREA OF THE PHILADELPHIA METRO AND
NOT ISSUE ANY ADDITIONAL HEADLINES ATTM.

FOR MONDAY AND TUESDAY, A TROUGH ACROSS THE NORTHEAST ALLOWS FOR
SOME COOLING TO TAKE PLACE WITH THE DEW POINTS ALSO A BIT LOWER.
HOWEVER, MODEL GUIDANCE HINTS AT THE HEIGHTS TRYING TO RISE AGAIN
DURING TUESDAY AS THE RIDGE TO THE WEST STARTS BUILDING. THE
WEAKENING FLOW TOWARD THE SOUTHWEST WILL ALLOW A SURFACE COLD FRONT
TO REMAIN NEARLY STATIONARY ACROSS THE MID ATLANTIC. THE TAIL END OF
THIS FRONT HOWEVER SHOULD LIFT NORTHEASTWARD DUE TO WAA AND A
SURFACE LOW TRACKING ACROSS SOUTHERN CANADA. WE STILL MAINTAIN A
NORTHWESTERLY FLOW ALOFT REGIME AND THIS COMBINED WITH THE POTENTIAL
FOR A SURFACE TROUGH TO SET UP IN THE VICINITY MAY HELP TO TRIGGER A
FEW STORMS ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS. WHILE
ATTM IT DOES NOT APPEAR ANOTHER MCS FEATURE DEVELOPS AND RIDES THE
NORTHWEST FLOW, THIS MAY HAVE TO BE WATCHED GIVEN WAA INTO THE GREAT
LAKES REGION COMBINED WITH AN INCOMING IMPULSE IN THAT VICINITY. FOR
NOW, WE KEPT THE POPS GENERALLY NO HIGHER THAN SLIGHT CHC.

FOR WEDNESDAY THROUGH FRIDAY, A SURFACE LOW IS FORECAST TO TRACK
ACROSS SOUTHEASTERN CANADA WHICH SHOULD PULL A WARM FRONT ACROSS OUR
AREA TUESDAY NIGHT INTO WEDNESDAY. THIS WOULD PUT OUR AREA IN THE
WARM SECTOR, HOWEVER A COLD FRONT IS THEN FORECAST TO ARRIVE
WEDNESDAY NIGHT INTO THURSDAY. BASED ON THE NORTHWESTERLY FLOW ALOFT
COMBINED WITH SUFFICIENT INSTABILITY AND FAVORABLE WIND AND THERMAL
FIELDS, AT LEAST SOME CONVECTION IS EXPECTED WEDNESDAY AND THURSDAY.
THERE IS THE POTENTIAL FOR AN MCS OR TWO TO DEVELOP UPSTREAM,
ALTHOUGH THERE IS LOWER CONFIDENCE REGARDING THIS AS IT LOOKS TO
DEPEND ON IF THERE ARE MCV'S TO HELP FOCUS CONVECTION. FOR NOW, WENT
WITH SLIGHT CHC TO CHC POPS TO INDICATE AT LEAST ISOLATED TO
SCATTERED CONVECTION WEDNESDAY AND THURSDAY. FOR FRIDAY, THE SURFACE
BOUNDARY SHOULD BE SHOVED FAR ENOUGH TO OUR SOUTH AS A SURFACE HIGH
BUILDS ACROSS THE GREAT LAKES AND INTO THE NORTHEAST. AS A RESULT,
WE OPTED TO GO WITH A DRY FORECAST. TEMPERATURES WERE MOSTLY HPC
GUIDANCE, WHICH RESULTED IN DAYTIME HIGHS IN THE 80S TO ABOUT 90.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

TONIGHT...VFR CONDITIONS WITH LIGHT WINDS. SOME HAZE MAY DEVELOP
TOWARD DAYBREAK, BUT WE DIDN'T HIT THAT VERY HARD IN THE LATEST
TAFS.

SATURDAY...VFR CONDITIONS. W TO SW WINDS EXPECTED, WITH SOME
GUSTINESS POSSIBLE DURING THE AFTERNOON. ISOLATED SHWRS/T-STORMS
POSSIBLE LATE IN THE DAY.

OUTLOOK...
SATURDAY NIGHT THROUGH SUNDAY NIGHT...VFR WITH THE EXCEPTION OF
POSSIBLE LOCAL SUB-VFR DUE TO FOG/HAZE DURING THE EARLY MORNINGS. A
COUPLE OF SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE, HOWEVER THERE
IS LOWER CONFIDENCE WITH THE TIMING AND OVERALL COVERAGE. GENERALLY
LIGHT AND VARIABLE WINDS AT NIGHT, THEN WESTERLY NEAR 10 KNOTS
DURING THE DAY. THE WINDS COULD SHIFT MORE SOUTHERLY LOCALLY IN THE
AFTERNOON AND EARLY EVENING DUE TO ANY MARINE INFLUENCE.

MONDAY AND TUESDAY...VFR, ALTHOUGH THERE STILL REMAINS THE CHANCE
FOR A FEW SHOWERS AND THUNDERSTORMS ESPECIALLY DURING THE AFTERNOON
AND EVENING HOURS. AS OF NOW, COVERAGE LOOKS TO BE ISOLATED TO
SCATTERED. WEST TO NORTHWEST WINDS NEAR 10 KNOTS MAY SHIFT TO THE
SOUTHWEST TUESDAY.

WEDNESDAY...A COLD FRONT ARRIVING SHOULD INITIATE SCATTERED SHOWERS
AND THUNDERSTORMS. THEREFORE, LOCAL SUB-VFR CONDITIONS ARE POSSIBLE
ALONG WITH LOCALLY GUSTY WINDS.

&&

.MARINE...
CONDITIONS ON OUR WATERS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
CRITERIA TONIGHT AND THROUGH SATURDAY. WINDS WILL PRIMARILY BE
SOUTHWESTERLY DURING THE PERIOD. TSTMS THREATEN THE SOUTHERN
WATERS LATE TONIGHT.

OUTLOOK...
THE CONDITIONS ARE ANTICIPATED TO BE BELOW SMALL CRAFT ADVISORY
CRITERIA THROUGH WEDNESDAY. A WEAK COLD FRONT SETTLES SOUTH AND
STALLS LATE SATURDAY AND SUNDAY. THIS THEN LIFTS BACK NORTHWARD AS A
WARM FRONT TUESDAY INTO WEDNESDAY, FOLLOWING BY ANOTHER COLD FRONT
WEDNESDAY NIGHT INTO THURSDAY. GIVEN A NORTHWESTERLY FLOW REGIME
ALOFT AND SHORT WAVE ENERGY EMBEDDED WITHIN, SOME SHOWERS AND
THUNDERSTORMS ARE POSSIBLE, WITH THE POTENTIAL FOR ORGANIZATION INTO
A CLUSTER LATER SATURDAY. ANY THUNDERSTORMS WILL BE CAPABLE OF
PRODUCING LOCALLY STRONG WINDS AND HAIL. THE FLOW WILL GENERALLY BE
WESTERLY, ALTHOUGH SOME SHIFTING TO A SOUTHERLY DIRECTION IS
EXPECTED AT TIMES. THE SEAS ARE ANTICIPATED TO REMAIN MAINLY IN THE
2 TO 4 FOOT RANGE.

&&

.TIDES/COASTAL FLOODING...
THERE IS THE POTENTIAL FOR SOME MINOR COASTAL FLOODING EPISODES WITH
THE EVENING TIDE CYCLES BEGINNING SUNDAY OR MONDAY AND CONTINUING
THROUGH AT LEAST TUESDAY. THE FULL MOON OCCURS ON TUESDAY AND THE
ASTRONOMICAL TIDE IS GENERALLY WITHIN 0.3 FEET OF THE MINOR TIDAL
FLOODING CRITERIA.

&&

.CLIMATE...
MPO (90 DEGREES) AND GED (101) SET DAILY RECORDS FOR THE 29TH.
PLEASE SEE PHLRERMPO AND PHLRERGED FOR ADDITIONAL INFORMATION.

TEMPERATURES ARE EXPECTED TO REACH WELL INTO THE 90S THROUGH
SUNDAY. BELOW ARE THE RECORD HIGH TEMPERATURES AND MOST RECENT
YEAR OF OCCURRENCE FOR JUNE 30 AND JULY 1 FOR OUR EIGHT CLIMATE
SITES.

        JUNE 30       JULY 1

PHL   100 - 1964   102 - 1901

ACY    98 - 1991    99 - 1968

ILG    98 - 1964    97 - 1963

ABE    97 - 1964    97 - 1963

TTN    98 - 1964    98 - 1945

RDG    98 - 1964   101 - 1901

GED   101 - 1959    98 - 1964

MPO    90 - 1964    88 - 1968

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT SUNDAY FOR PAZ067>071.
NJ...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT SUNDAY FOR NJZ015-
     017>019.
DE...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT SUNDAY FOR DEZ001.
MD...NONE.
MARINE...NONE.

&&

SYNOPSIS...GORSE
NEAR TERM...KLINE/DELISI
SHORT TERM...KLINE
LONG TERM...GORSE
AVIATION...GORSE/KLINE/DELISI
MARINE...GORSE/KLINE/DELISI
TIDES/COASTAL FLOODING...GIGI/GORSE
CLIMATE...KLINE

Hazardous weather outlook, Jun 29, 9:14 PM EST, 1 hour 8 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1014 PM EDT FRI JUN 29 2012

NJZ001-PAZ054-055-010215-
SUSSEX-CARBON-MONROE-
1014 PM EDT FRI JUN 29 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHERN NEW JERSEY AND
NORTHEAST PENNSYLVANIA.

.DAY ONE...TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

THERE IS A CHANCE OF SOME STRONG TO SEVERE THUNDERSTORMS ON
SATURDAY WITH LOCALLY STRONG WINDS AND HAIL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NJZ007>010-012-013-020-027-PAZ060>062-010215-
WARREN-MORRIS-HUNTERDON-SOMERSET-MIDDLESEX-WESTERN MONMOUTH-OCEAN-
SOUTHEASTERN BURLINGTON-BERKS-LEHIGH-NORTHAMPTON-
1014 PM EDT FRI JUN 29 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NEW JERSEY...NORTHERN
NEW JERSEY...NORTHWEST NEW JERSEY...SOUTHERN NEW JERSEY AND EAST
CENTRAL PENNSYLVANIA.

.DAY ONE...TONIGHT.

HAZARDOUS WEATHER NOT IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

THERE IS A CHANCE OF SOME STRONG TO SEVERE THUNDERSTORMS ON
SATURDAY WITH LOCALLY STRONG WINDS AND HAIL.

ALSO, THE HEAT CONTINUES SATURDAY AND SUNDAY AND THE AFTERNOON
HEAT INDICES COULD NEAR 100 DEGREES.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NJZ016-021>023-010215-
SALEM-CUMBERLAND-ATLANTIC-CAPE MAY-
1014 PM EDT FRI JUN 29 2012

...SEVERE THUNDERSTORM WATCH 439 IN EFFECT UNTIL 2 AM EDT SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHERN NEW JERSEY.

.DAY ONE...TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   SEVERE THUNDERSTORM WATCH.

HAZARDOUS WEATHER NOT IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

THERE IS A CHANCE OF SOME STRONG TO SEVERE THUNDERSTORMS ON
SATURDAY WITH LOCALLY STRONG WINDS AND HAIL.

ALSO, THE HEAT CONTINUES SATURDAY AND SUNDAY AND THE AFTERNOON
HEAT INDICES COULD NEAR 100 DEGREES.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NJZ015-018-019-PAZ067>071-010215-
MERCER-CAMDEN-NORTHWESTERN BURLINGTON-CHESTER-MONTGOMERY-BUCKS-
DELAWARE-PHILADELPHIA-
1014 PM EDT FRI JUN 29 2012

...EXCESSIVE HEAT WARNING IN EFFECT UNTIL 8 PM EDT SUNDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NEW JERSEY...SOUTHERN
NEW JERSEY AND SOUTHEAST PENNSYLVANIA.

.DAY ONE...TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   EXCESSIVE HEAT WARNING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   EXCESSIVE HEAT WARNING.

ALSO, THERE IS A CHANCE OF SOME STRONG TO SEVERE THUNDERSTORMS ON
SATURDAY WITH LOCALLY STRONG WINDS AND HAIL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NJZ017-010215-
GLOUCESTER-
1014 PM EDT FRI JUN 29 2012

...EXCESSIVE HEAT WARNING IN EFFECT UNTIL 8 PM EDT SUNDAY...
...SEVERE THUNDERSTORM WATCH 439 IN EFFECT UNTIL 2 AM EDT SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHERN NEW JERSEY.

.DAY ONE...TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   EXCESSIVE HEAT WARNING.
   SEVERE THUNDERSTORM WATCH.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   EXCESSIVE HEAT WARNING.

ALSO, THERE IS A CHANCE OF SOME STRONG TO SEVERE THUNDERSTORMS ON
SATURDAY WITH LOCALLY STRONG WINDS AND HAIL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NJZ014-026-010215-
EASTERN MONMOUTH-COASTAL OCEAN-
1014 PM EDT FRI JUN 29 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NEW JERSEY AND
SOUTHERN NEW JERSEY.

.DAY ONE...TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

THERE IS A CHANCE OF SOME STRONG TO SEVERE THUNDERSTORMS ON
SATURDAY WITH LOCALLY STRONG WINDS AND HAIL.

ALSO, THERE IS A CHANCE OF SOME MINOR TIDAL FLOODING NEAR THE
TIME OF THE EVENING HIGH TIDE MONDAY THROUGH WEDNESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NJZ024-025-010215-
ATLANTIC COASTAL CAPE MAY-COASTAL ATLANTIC-
1014 PM EDT FRI JUN 29 2012

...SEVERE THUNDERSTORM WATCH 439 IN EFFECT UNTIL 2 AM EDT SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHERN NEW JERSEY.

.DAY ONE...TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   SEVERE THUNDERSTORM WATCH.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

THERE IS A CHANCE OF SOME STRONG TO SEVERE THUNDERSTORMS ON
SATURDAY WITH LOCALLY STRONG WINDS AND HAIL.

ALSO, THERE IS A CHANCE OF SOME MINOR TIDAL FLOODING NEAR THE
TIME OF THE EVENING HIGH TIDE MONDAY THROUGH WEDNESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

DEZ002-003-MDZ008-012-015-019-020-010215-
KENT-INLAND SUSSEX-CECIL-KENT MD-QUEEN ANNES-TALBOT-CAROLINE-
1014 PM EDT FRI JUN 29 2012

...SEVERE THUNDERSTORM WATCH 439 IN EFFECT UNTIL 2 AM EDT SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL DELAWARE...SOUTHERN
DELAWARE AND NORTHEAST MARYLAND.

.DAY ONE...TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   SEVERE THUNDERSTORM WATCH.

A FEW STRONG THUNDERSTORMS ARE POSSIBLE TONIGHT.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

THERE IS A CHANCE OF SOME STRONG TO SEVERE THUNDERSTORMS ON
SATURDAY WITH LOCALLY STRONG WINDS AND HAIL.

ALSO, THE HEAT CONTINUES SATURDAY AND SUNDAY AND THE AFTERNOON
HEAT INDICES COULD NEAR 105 DEGREES.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

DEZ001-010215-
NEW CASTLE-
1014 PM EDT FRI JUN 29 2012

...EXCESSIVE HEAT WARNING IN EFFECT UNTIL 8 PM EDT SUNDAY...
...SEVERE THUNDERSTORM WATCH 439 IN EFFECT UNTIL 2 AM EDT SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHERN DELAWARE.

.DAY ONE...TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   EXCESSIVE HEAT WARNING.
   SEVERE THUNDERSTORM WATCH.

ALSO, A FEW STRONG THUNDERSTORMS ARE POSSIBLE TONIGHT.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   EXCESSIVE HEAT WARNING.

ALSO, THERE IS A CHANCE OF SOME STRONG TO SEVERE THUNDERSTORMS ON
SATURDAY WITH LOCALLY STRONG WINDS AND HAIL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

DEZ004-010215-
DELAWARE BEACHES-
1014 PM EDT FRI JUN 29 2012

...SEVERE THUNDERSTORM WATCH 439 IN EFFECT UNTIL 2 AM EDT SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHERN DELAWARE.

.DAY ONE...TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   SEVERE THUNDERSTORM WATCH.

A FEW STRONG THUNDERSTORMS ARE POSSIBLE TONIGHT.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

THERE IS A CHANCE OF SOME STRONG TO SEVERE THUNDERSTORMS ON
SATURDAY WITH LOCALLY STRONG WINDS AND HAIL.

ALSO, THERE IS A CHANCE OF SOME MINOR TIDAL FLOODING NEAR THE
TIME OF THE EVENING HIGH TIDE MONDAY THROUGH WEDNESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

ANZ452-453-010215-
COASTAL WATERS FROM LITTLE EGG INLET TO GREAT EGG INLET NJ OUT 20 NM-
COASTAL WATERS FROM GREAT EGG INLET TO CAPE MAY NJ OUT 20 NM-
1014 PM EDT FRI JUN 29 2012

...SEVERE THUNDERSTORM WATCH 439 IN EFFECT UNTIL 2 AM EDT SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR ATLANTIC COASTAL WATERS.

.DAY ONE...TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   SEVERE THUNDERSTORM WATCH.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

THERE IS A CHANCE OF SOME STRONG THUNDERSTORMS ON SATURDAY WITH
LOCALLY STRONG WINDS AND HAIL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

ANZ450-451-010215-
COASTAL WATERS FROM SANDY HOOK TO MANASQUAN INLET NJ OUT 20 NM-
COASTAL WATERS FROM MANASQUAN INLET TO LITTLE EGG INLET NJ OUT 20 NM-
1014 PM EDT FRI JUN 29 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR ATLANTIC COASTAL WATERS.

.DAY ONE...TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

THERE IS A CHANCE OF SOME STRONG THUNDERSTORMS ON SATURDAY WITH
LOCALLY STRONG WINDS AND HAIL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

ANZ430-431-454-455-010215-
DELAWARE BAY WATERS NORTH OF EAST POINT NJ TO SLAUGHTER BEACH DE-
DELAWARE BAY WATERS SOUTH OF EAST POINT NJ TO SLAUGHTER BEACH DE-
COASTAL WATERS FROM CAPE MAY NJ TO CAPE HENLOPEN DE OUT 20 NM-
COASTAL WATERS FROM CAPE HENLOPEN TO FENWICK ISLAND DE OUT 20 NM-
1014 PM EDT FRI JUN 29 2012

...SEVERE THUNDERSTORM WATCH 439 IN EFFECT UNTIL 2 AM EDT SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR ATLANTIC COASTAL WATERS AND
DELAWARE BAY WATERS.

.DAY ONE...TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   SEVERE THUNDERSTORM WATCH.

A FEW STRONG THUNDERSTORMS ARE POSSIBLE TONIGHT.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

THERE IS A CHANCE OF SOME STRONG THUNDERSTORMS ON SATURDAY WITH
LOCALLY STRONG WINDS AND HAIL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

In the hours before

Special weather statement, Jun 29, 8:59 PM EST, 1 hour 23 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
959 PM EDT FRI JUN 29 2012

DEZ001>004-MDZ008-012-015-019-020-NJZ016-021-023-300400-
NEW CASTLE-KENT-INLAND SUSSEX-DELAWARE BEACHES-CECIL-KENT MD-
QUEEN ANNES-TALBOT-CAROLINE-SALEM-CUMBERLAND-CAPE MAY-
INCLUDING THE CITIES OF...WILMINGTON...DOVER...GEORGETOWN...
REHOBOTH BEACH...ELKTON...CHESTERTOWN...CENTREVILLE...EASTON...
DENTON...PENNSVILLE...MILLVILLE...CAPE MAY COURT HOUSE
959 PM EDT FRI JUN 29 2012

...SEVERE WEATHER LIKELY LATE THIS EVENING...

A LINE OF VERY STRONG TO SEVERE THUNDERSTORMS IS MOVING RAPIDLY
EASTWARD ACROSS MARYLAND AND NORTHERN VIRGINIA AT THIS TIME. THIS
LINE OF STORMS IS PRODUCING WIDESPREAD REPORTS OF WIND DAMAGE WITH
MANY TREES DOWN AND SOME STRUCTURAL DAMAGE. THUNDERSTORM WIND
GUSTS UP TO 80 MPH HAVE ALSO BEEN REPORTED.

THESE STORMS WILL AFFECT DELMARVA AND PARTS OF SOUTHERN NEW JERSEY
BETWEEN 1100 PM AND 100 AM. A SEVERE THUNDERSTORM WATCH IS LIKELY
TO BE ISSUED WITHIN THE NEXT FEW MINUTES.

AMC

Special weather statement, Jun 29, 9:54 PM EST, 28 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1054 PM EDT FRI JUN 29 2012

PAZ067-070-300345-
CHESTER PA-DELAWARE PA-
1054 PM EDT FRI JUN 29 2012

...STRONG THUNDERSTORMS WILL AFFECT CHESTER AND DELAWARE COUNTIES...

AT 1048 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS DEVELOPING OVER LANCASTER COUNTY...MOVING EAST
AT 35 MPH. THESE STORMS WILL BE SPREADING INTO CHESTER AND DELAWARE
COUNTIES OVER THE NEXT HOUR OR SO.

VERY HEAVY RAIN AND SMALL HAIL WILL FALL FROM THESE STORMS...AND
WILL CAUSE WATER TO POND ON ROADS AND QUICKLY FILL POOR DRAINAGE
AREAS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THESE STORMS. DO
NOT SEEK SHELTER UNDER TREES WHEN LIGHTNING THREATENS...MOVE INDOORS
WHEN A THUNDERSTORM APPROACHES.

LAT...LON 3973 7609 3987 7599 3992 7600 4003 7594
      4011 7595 4024 7571 4024 7560 4014 7551
      4013 7546 4009 7546 4007 7537 3994 7524
      3988 7526 3986 7521 3985 7533 3980 7541
      3984 7560 3981 7570 3972 7578 3972 7614

FORECASTER: AMC

Special weather statement, Jun 29, 10:22 PM EST, 0 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1122 PM EDT FRI JUN 29 2012

DEZ001-MDZ008-300415-
CECIL MD-NEW CASTLE DE-
1122 PM EDT FRI JUN 29 2012

...STRONG THUNDERSTORMS WILL AFFECT CECIL AND NEW CASTLE COUNTIES...

AT 1114 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS MOVING EAST ACROSS HARFORD COUNTY IN NORTHEAST
MARYLAND. THESE STORMS WILL SPREAD ACROSS CECIL COUNTY MARYLAND INTO
NEW CASTLE COUNTY DELAWARE DURING THE NEXT HOUR OR SO.

VERY HEAVY RAIN WILL FALL FROM THESE STORMS...AND WILL CAUSE WATER TO
POND ON ROADS AND QUICKLY FILL POOR DRAINAGE AREAS. ONE SHOULD ALSO
EXPECT SMALL HAIL AND FREQUENT...DANGEROUS CLOUD TO GROUND LIGHTNING
FROM THESE STORMS.

IF A THUNDERSTORM APPROACHES...TAKE COVER INSIDE A STURDY BUILDING.

LAT...LON 3972 7578 3983 7565 3982 7544 3979 7541
      3962 7560 3960 7560 3964 7557 3952 7555
      3946 7558 3936 7551 3931 7559 3929 7568
      3930 7576 3938 7577 3938 7605 3943 7600
      3952 7599 3954 7607 3972 7623

FORECASTER: AMC

The radar

The Dover AFB radar (KDOX), 78 km away, was scanning. The volume nearest the first event began at 03:23 UTC.

Open the radar archive at this moment

Event by event

5 thunderstorm wind. Local standard time, as filed.

Thunderstorm Wind, Talbot

When: June 29, 10:22 PM EST to 11:31 PM EST
Where: Talbot County, Tilghman to Matthews
Measured: 56 kt (64 mph) estimated gust
Property damage: $50,000
Reported by: County Official
Coordinates: 38.720, -76.330

A gust front outrunning a cluster of severe thunderstorms entered the Tilghman Island area of western Talbot County at approximately 11:22 pm EDT on the 29th. This gust front produced damaging wind gusts estimated at 65 mph as it traversed eastward across the county. Within approximately 20 minutes of the gust front passage, a potent line of severe thunderstorms tracked eastward through Talbot County, producing another round of destructive wind gusts, estimated at 65 mph. A significant number of trees and electric wires were reported down county-wide with damage first being noted on Tilghman Island. Severe thunderstorms exited eastern Talbot County, including the town of Matthews, at approximately 12:31 am EDT on the 30th.

Thunderstorm Wind, Queen Anne'S

When: June 29, 10:22 PM EST to 11:31 PM EST
Where: Queen Anne'S County, Stevensville to Sudlersville
Measured: 56 kt (64 mph) estimated gust
Property damage: $100,000
Reported by: Trained Spotter
Coordinates: 38.980, -76.320

A gust front outrunning a cluster of severe thunderstorms entered near Stevensville in western Queen Anne's County at approximately 11:22 pm EDT on the 29th. This gust front produced damaging wind gusts estimated at 65 mph as it traversed eastward across the county. Within approximately 20 minutes of the gust front passage, a potent line of severe thunderstorms tracked eastward through Queen Anne's County, producing another round of destructive wind gusts, estimated at 65 mph. Large tree limbs and electric wires were reported down across the county, with damage initially reported in the Stevensville area. Damage to a large chimney and the exterior walls of a home was also reported in Stevensville. Severe thunderstorms exited eastern Queen Anne's County, including the town of Sudlersville, at approximately 12:31 am EDT on the 30th.

Thunderstorm Wind, Kent

When: June 29, 10:22 PM EST to 11:31 PM EST
Where: Kent County, Rock Hall to Massey
Measured: 57 kt (66 mph) measured gust
Property damage: $20,000
Reported by: Trained Spotter
Coordinates: 39.130, -76.230

A gust front outrunning a cluster of severe thunderstorms entered near Rock Hall in western Kent County at approximately 11:22 pm EDT on the 29th. This gust front produced damaging wind gusts estimated at 65 mph as it traversed eastward across the county. Within approximately 20 minutes of the gust front passage, a potent line of severe thunderstorms tracked eastward through Kent County, producing another round of destructive wind gusts, estimated at 65 mph. Many large tree limbs were reported down across the county, including in the Millington area. Severe thunderstorms exited eastern Kent County, near Massey, at approximately 12:31 am EDT on the 30th. A peak wind gust of 66 mph was measured at Tolchester Beach.

Thunderstorm Wind, Cecil

When: June 29, 10:27 PM EST to 11:40 PM EST
Where: Cecil County, 1 mi E of Port Deposit to Elkton
Measured: 61 kt (70 mph) estimated gust
Injuries: 1 direct, 1 indirect
Property damage: $500,000
Reported by: Emergency Manager
Coordinates: 39.600, -76.101

A gust front outrunning a cluster of severe thunderstorms entered near Port Deposit in western Cecil County at approximately 11:27 pm EDT on the 29th. This gust front produced damaging wind gusts estimated from 65 to 70 mph as it traversed eastward across the county. Within approximately 20 minutes of the gust front passage, a potent line of severe thunderstorms tracked eastward into Cecil County. One thunderstorm cell in particular experienced rapid intensification and expansion as it tracked from around Baltimore, MD across Cecil County and into northern Delaware. Destructive wind gusts, estimated at 70 mph, resulted in significant tree and power line damage county-wide. Approximately 35 roads were impassable due to numerous downed trees. In Chesapeake City, several large trees fell onto homes, resulting in one injury. A tree also fell onto a house in the town of North East. Damage to multiple buildings was reported in Warwick, and a large concentration of downed trees was reported in Cecilton. Severe thunderstorms exited eastern Cecil County, including the town of Elkton, at approximately 12:40 am EDT on the 30th. A young man was critically injured on the morning of July 2 around 330 am EDT when a tree branch fell on his tent at Camp Rodney in Elk Neck State Park in Northeast, Maryland. It is believed that the tree was weakened by the derecho that went through the night of the 29th.

Thunderstorm Wind, Caroline

When: June 29, 10:40 PM EST to 11:49 PM EST
Where: Caroline County, Harmony to Henderson
Measured: 56 kt (64 mph) estimated gust
Property damage: $50,000
Reported by: Newspaper
Coordinates: 38.780, -75.870

A gust front outrunning a cluster of severe thunderstorms entered near Harmony in western Caroline County at approximately 11:40 pm EDT on the 29th. This gust front produced damaging wind gusts estimated at 65 mph as it traversed eastward across the county. Within approximately 20 minutes of the gust front passage, a potent line of severe thunderstorms tracked eastward through Caroline County, producing another round of destructive wind gusts, estimated at 65 mph. Trees and electric wires were reported down across the county. Severe thunderstorms exited eastern Caroline County, including the town of Henderson, at approximately 12:49 am EDT on the 30th.

What these are

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.

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

The same day elsewhere

Every storm in Maryland in 2012 Every state in 2012 This day in weather history Warnings in Maryland, June 2012

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: 390779, 392945, 392954, 393136, 393126.