Severe thunderstorms moved across eastern Maine during the afternon of the 20th in advance of a cold front crossing the region. The storms produced damaging winds and large hail.
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 CAR wrote it up.
Severe thunderstorms moved across eastern Maine during the afternon of the 20th in advance of a cold front crossing the region. The storms produced damaging winds and large hail.
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 Caribou, ME wrote its last area forecast discussion before the first event at Jun 20, 4:08 AM EST, 6 hours 52 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 508 AM EDT SUN JUN 20 2010 .SYNOPSIS... A WEAK WAVE OF LOW PRESSURE AND ASSOCIATED COLD FRONT WILL CROSS THE REGION TODAY. THE LOW WILL MOVE EAST THROUGH THE MARITIMES TONIGHT. HIGH PRESSURE WILL RETURN FOR MONDAY AND TUESDAY. ANOTHER COLD FRONT WILL APPROACH LATE WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... A TRICKY FCST SETTING UP FOR TODAY INTO THE EVENING IN REGARDS TO STRONG CONVECTION AND FOG DEVELOPMENT. UPDATED THE COASTAL REGION THIS MORNING FOR ISOLD TSTMS DUE TO SOME ELEVATED CONVECTION MOVING ACROSS THE REGION. LAPS SOUNDINGS FOR KBGR AND KBHB SHOWING THINGS DESTABILIZING. THE LATEST HRR3KM WAS HANDLING THE FIRST BATCH OF SHOWERS QUITE WELL AND HAD DWPTS WELL IN HAND AS WELL. THEREFORE...DECIDED TO DRY THINGS OUT FOR A TIME THIS MORNING AS DEPICTED BY THE HRR3KM AND THEN RAMPED THINGS UP BY MID MORNING AND CONTINUED THAT TREND INTO THE AFTERNOON. SREF POPS WERE USED TODAY W/THE HIGHEST POPS(70-80%) MAINLY ACROSS CAR/HUL DOWN THROUGH MLT AND BGR. THE AIRMASS IS DESTABILIZING AND THE EXPECTATION IS FOR IT TO CONTINUE INTO THE AFTERNOON. THE GFS IS THE MOST AGGRESSIVE W/BRINGING SBCAPES OF 2000+ J/KG ACROSS PORTIONS OF NORTHERN MAINE AND THROUGH CENTRAL & DOWNEAST AREAS BY EARLY AFTERNOON. THE NAM HOLDS THINGS DOWN TO 1000-1500 J/KG. THE KEY IS THE DWPTS AS THE GFS IS HIGHER BRINGING LOWER 70S ACROSS THE AFOREMENTIONED REGION AND THE NAM IS IN THE MID 60S. THE HRR3KM THROUGH 18Z ALIGNED IN THE MIDDLE AND THE DECISION WAS TO USE IT THROUGH 18Z. SOME HEATING IS EXPECTED AS WELL EARLY ON TO INCREASE THE INSTABILITY. SOUNDINGS SHOW A MOISTENING SOUNDING FROM TOP-DOWN W/PWS ABV 1.5" AND K INDICES HITTING ABV 35+. THEREFORE...TSTMS LOOK TO BE A GOOD BET EVEN TO THE COAST AS MARINE LAYER LOOKS TO GET ERODED THIS AFTERNOON. SPEED SHEAR IS MARGINAL W/0-6KM SHEAR AROUND 20 KTS. HOWEVER...LCLS ARE EXPECTED TO DROP TO <3500 FT AND SOME TURNING IS THERE FROM 1-3KM. STRONGER STORMS COULD SHOW ROTATION. 0-3KM EHI VALUES CLOSE IN ON 1. LAPSE RATES FROM 850-500MB MARGINAL AT 6.0 C/KM. HOWEVER...LOOKING AT 925-850MBS LAPSE RATES INDICATES VALUES ABV 7.0C KM. HAIL POTENTIAL IS MARGINAL W/WBZS ABV 11K FT. SPC KEEPS SLIGHT RISK AROUND SRN MAINE. A THETA E RIDGE SETS UP W/VALUES FROM 925-850 CLOSING IN ON 340K IN THE AFOREMENTIONED REGIONS. BULK SHEAR IS 30 KTS AT BEST. CORFIDI VECTORS SUPPORT CELLS TO REGENERATE AND THE POTENTIAL FOR TRAINING AS THE COLD FRONT SLOWLY MOVES THROUGH THE STATE THIS AFTERNOON. THEREFORE...VERY HEAVY RAINFALL W/THE POTENTIAL FOR FLASH FLOODING IS THERE. THIS WILL NEED TO BE WATCHED BY THE DAYCREW. FOR TONIGHT...THINGS WIND DOWN AS THE FRONT PULLS E AND A NW FLOW TAKES OVER. SKIES WILL BEGIN TO GRADUALLY CLEAR LATER ON AND W/THE WET GROUND AND COOLING...DECISION WAS TO GO AHEAD W/AREAS OF FOG. DAYCREWS MAX TEMPERATURES LOOKED IN GOOD SHAPE. SOME MODIFICATION WAS TO DONE TO HRLY TEMPERATURES FAVORING THE REGIONAL GEM AS RAINFALL WILL COOL THINGS DOWN LATER THIS AFTERNOON. ADJUSTED THE MIN TEMPERATURES UP A FEW DEGREES. && .SHORT TERM /MONDAY THROUGH TUESDAY/... A SMALL WAVE OF LOW PRESSURE WILL BE MOVING EAST AND AWAY THROUGH THE MARITIMES ON MONDAY AS THE TRAILING COLD FRONT PUSHES OFFSHORE. GUIDANCE SHOWS A VERY WEAK TRAILING SHORTWAVE MOVING ACROSS DOWNEAST AREAS DURING THE MORNING AND MIDDAY MONDAY WITH CAPES APPROACHING 500 J/KG. THIS COULD PRODUCE AN ISOLATED SHOWER OR THUNDERSTORM WITH BEST CHANCES DOWNEAST. A WARM DAY IS EXPECTED ACROSS THE REGION WITH HIGHS NEAR OR JUST ABOVE 80 IN MOST PLACES. HIGH PRESSURE BUILDING IN WILL BRING ANOTHER WARM DAY TUESDAY AS TEMPS RISE WELL INTO THE 80S UNDER PLENTY OF SUNSHINE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A SHORTWAVE AND ASSOCIATED LOW PRESSURE SYSTEM WILL APPROACH WEDNESDAY. AS THE LOW TRACKS TO OUR NORTH WINDS WILL INCREASE FROM THE SOUTH. THE COLD FRONT WILL MOVE IN LATE WEDNESDAY AND CROSS THE AREA LATE WEDNESDAY EVENING. MODELS SHOW A SIGNIFICANT CHANCE FOR CONVECTION TO OUR WEST OVER THE SAINT LAWRENCE VALLEY. HOWEVER...THE ATMOSPHERE IS EXPECTED TO BECOMING INCREASINGLY STABLE AS THE FRONT REACHES OUR AREA. THIS MAY BE DUE TO SOUTHERLY WINDS PULLING COOLER MORE STABLE AIR NORTH FROM THE OCEAN. NEVERTHELESS...THE SHORTWAVE IS EXPECTED TO BE STRONG WITH MODERATE VERTICAL VELOCITIES PROJECTED ACROSS THE NORTH AS IT MOVES THROUGH SO WILL STILL MENTION CHC FOR THUNDER AS THE FRONT MOVES IN. A TRAILING SHORTWAVE ON THURSDAY MAY BRING SOME SHOWERS AND THUNDERSTORMS DOWNEAST. SLIGHTLY COOLER HIGH PRESSURE SHOULD FOLLOW FOR FRIDAY BEFORE A WARM FRONT LIFTS ACROSS THE AREA ON SATURDAY. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... NEAR TERM: VFR W/SOME AREAS OF MVFR OUT THERE ATTM MAINLY FOR KHUL WHILE BHB WAS SHOWING IFR BUT HAS SINCE IMPROVED TO VFR. EXPECTING CONDITIONS TO DROP BACK TO MVFR AND EVEN IFR THIS AFTERNOON INTO EARLY EVENING W/SHOWERS AND TSTMS. AREAS OF FOG TONIGHT COULD VERY WELL DROP THINGS BACK TO IFR ACROSS MUCH OF THE TAF SITES. SHORT TERM: VFR CONDITIONS ARE EXPECTED ACROSS THE AREA MONDAY INTO EARLY WEDNESDAY. CONDITIONS MAY LOWER TO MVFR OR IFR IN LOW CLOUDS LATE WEDNESDAY INTO WEDNESDAY NIGHT AS A FRONTAL SYSTEM MOVES ACROSS. VFR CONDITIONS SHOULD RETURN TO THE NORTH ON THURSDAY BUT MVFR OR IFR CONDITIONS MAY LINGER DOWNEAST AS ANOTHER SHORTWAVE MOVES THROUGH. && .MARINE... NEAR TERM: MAIN CONCERN IS THE 3-4 FOOT SWELL OUT THERE ATTM. WNAWAVE HAS CAUGHT ON. CURRENT WAVE HEIGHT GRIDS LOOKED GOOD AND ONLY ADJUSTMENTS WERE TO KEEP A 4 FOOT SWELL IN THERE THROUGH THE EVENING. WINDS OF 10-15 KT THROUGH TONIGHT. SHORT TERM: WINDS AND SEAS ARE EXPECTED TO BE BELOW SCA THROUGH THE COMING WEEK. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && NEAR TERM...HEWITT SHORT TERM...BLOOMER LONG TERM...BLOOMER AVIATION...HEWITT MARINE...HEWITT/BLOOMER
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CARIBOU ME 425 AM EDT SUN JUN 20 2010 MEZ001>006-010-011-015>017-029>032-210830- NORTHWEST AROOSTOOK-NORTHEAST AROOSTOOK-NORTHERN SOMERSET- NORTHERN PISCATAQUIS-NORTHERN PENOBSCOT-SOUTHEAST AROOSTOOK- CENTRAL PISCATAQUIS-CENTRAL PENOBSCOT-SOUTHERN PENOBSCOT- INTERIOR HANCOCK-CENTRAL WASHINGTON-COASTAL HANCOCK- COASTAL WASHINGTON-SOUTHERN PISCATAQUIS-NORTHERN WASHINGTON- 425 AM EDT SUN JUN 20 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL MAINE...NORTH CENTRAL MAINE...NORTHERN MAINE...SOUTHEAST MAINE AND WEST CENTRAL MAINE. .DAY ONE...TODAY AND TONIGHT. THUNDERSTORMS ARE EXPECTED TO DEVELOPMENT THIS AFTERNOON AND CONTINUE INTO THE EARLY EVENING. THUNDERSTORMS HAVE THE POTENTIAL FOR VERY HEAVY RAINFALL AND GUSTY WINDS. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED TODAY. HEWITT
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE CARIBOU ME 1022 AM EDT SUN JUN 20 2010 MEZ001>006-010-201600- NORTHWEST AROOSTOOK-NORTHEAST AROOSTOOK-NORTHERN SOMERSET- NORTHERN PISCATAQUIS-NORTHERN PENOBSCOT-SOUTHEAST AROOSTOOK- CENTRAL PISCATAQUIS- INCLUDING THE CITIES OF...ALLAGASH...CLAYTON LAKE...MADAWASKA... FORT KENT...FRENCHVILLE...PRESQUE ISLE...CARIBOU...VAN BUREN... MARS HILL...BAKER LAKE...BILLY-JACK DEPOT...BAXTER ST PARK... CHAMBERLAIN LAKE...CHURCHILL DAM...MOUNT KATAHDIN...MILLINOCKET... EAST MILLINOCKET...PATTEN...MEDWAY...HOULTON...HODGDON... SHERMAN...SMYRNA MILLS...GREENVILLE...MONSON...BLANCHARD 1022 AM EDT SUN JUN 20 2010 ...STRONG THUNDERSTORMS WILL CROSS NORTHERN MAINE THIS MORNING... AN AREA OF THUNDERSTORMS WILL CROSS NORTHWEST MAINE...INCLUDING THE ALLAGASH WILDERNESS AREA AND BAXTER STATE PARK...THROUGH THE REMAINDER OF THE MORNING. THE THUNDERSTORMS WILL BEGIN TO AFFECT EASTERN PORTIONS OF AROOSTOOK COUNTY AND NORTHERN PENOBSCOT COUNTY AFTER 11 AM. ANY THUNDERSTORMS COULD CONTAIN FREQUENT DEADLY LIGHTNING...WIND GUSTS UP TO 40 MPH AND HEAVY DOWNPOURS. IF THREATENING WEATHER APPROACHES SEEK SAFE SHELTER IMMEDIATELY. LISTEN TO NOAA WEATHER RADIO OR YOUR LOCAL MEDIA FOR THE LATER UPDATES ON THIS SITUATION. NORCROSS
The Caribou radar (KCBW), 81 km away, was scanning. The volume nearest the first event began at 16:01 UTC.
5 thunderstorm wind, 1 hail. Local standard time, as filed.
Trees were toppled on Strickland Road by wind gusts estimated at 60 mph.
A tree was toppled on to powerlines on Dow Siding Road by wind gusts estimated at 60 mph.
Trees were toppled along Parsons Road and Castle Hill Road by wind gusts estimated at 60 mph.
Two trees were toppled on to Route 11 by wind gusts estimated at 60 mph.
A tree was toppled on Route 6 by wind gusts estimated at 60 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Maine in 2010Every state in 2010This day in weather historyWarnings in Maine, June 2010
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: 238990, 238992, 238994, 238995, 238996, 238997.