A shortwave and associated cold front were approaching from the northwest during the late afternoon and evening hours of July 17th. Very high precipitable water values and very warm temperatures ahead of the front combined with increasing shear to produce numerous severe thunderstorms, mainly during the evening hours.
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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 GYX wrote it up.
A shortwave and associated cold front were approaching from the northwest during the late afternoon and evening hours of July 17th. Very high precipitable water values and very warm temperatures ahead of the front combined with increasing shear to produce numerous severe thunderstorms, mainly during the evening hours. Due to high freezing levels, wind damage and very heavy rain were the main features of these storms as they moved through the region.
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 Gray, ME wrote its last area forecast discussion before the first event at Jul 17, 5:45 PM EST, 1 hour 25 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 645 PM EDT WED JUL 17 2013 .SYNOPSIS... A WEAK COLD FRONT WILL SLOWLY CROSS NORTHERN MAINE TONIGHT... PRODUCING A TREAT FOR SHOWERS AND THUNDERSTORMS. THE FRONT WILL PUSH BACK TO THE NORTH ON THURSDAY...MAKING FOR A RETURN TO HOT AND HUMID WEATHER ON FRIDAY. A COLD FRONT WILL DROP SOUTH FROM CANADA FRIDAY NIGHT AND WILL CROSS THE REGION ON SATURDAY...POSSIBLY SETTING OFF A ROUND OF STRONG TO SEVERE THUNDERSTORMS. COOLER AND LESS HUMID HIGH PRESSURE BUILDS IN ON SUNDAY AND LINGERS INTO EARLY NEXT WEEK...BEFORE THINGS START SHOW SIGNS OF WARMING UP AGAIN. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... WILL UPDATE TO SLOW DOWN ONSET OF SHOWERS AND THUNDERSTORMS THIS EVENING PER LATEST RADAR MOSAIC LOOP. STILL EXPECTING CONVECTIVE ACTIVITY TO ARRIVE THROUGH THE COURSE OF THE EVENING HOURS... LIKELY HOLDING OFF UNTIL LATE EVENING ALONG THE COAST. ANY OTHER CHANGES VERY MINIMAL AT THIS TIME. ZONES UPDATED TO ADD THE SEVERE THUNDERSTORM WATCH THROUGH MIDNIGHT TONIGHT. ALREADY HAVE POSSIBLE SEVERE THUNDERSTORMS IN THE FORECAST FOR THIS EVENING. SHOWERS AND THUNDERSTORMS DEVELOPING OVER ONTARIO WILL MOVE SOUTHEAST AND INTO NORTHERN NEW ENGLAND TONIGHT. THIS ACTIVITY WILL BE PRIMARILY DRIVEN BY A SHORTWAVE TROUGH AND SURFACE COLD FRONT INTERACTING WITH A VERY WARM/MOIST PRE-FRONTAL ENVIRONMENT. HRRR MODEL SEEMS TO BE HANDLING THE FORECAST VERY WELL TODAY AND THIS WAS USED EXTENSIVELY IN THE NEAR TERM FORECAST FOR TONIGHT. AS COORDINATED WITH THE STORM PREDICTION CENTER... IT APPEARS THAT INITIALLY ISOLATED CONVECTIVE ACTIVITY OVER CANADA AND UPSTATE NEW YORK WILL LIKELY EVOLVE INTO A SQUALL LINE AND MOVE SOUTHEAST THROUGH VERMONT AND NEW HAMPSHIRE AND INTO MAINE. HRRR MODEL SEEMS TO BE SHOWING THE SIGNS OF AN MESOSCALE CONVECTIVE SYSTEM WITH TRAILING STRATIFORM RAIN REGION BEHIND IT ARRIVING IN NEW HAMPSHIRE AROUND 7 TO 8 PM AND HOLDING TOGETHER ALL THE WAY TO THE COAST BY MIDNIGHT. DAMAGING WINDS WILL BE THE BIGGEST THREAT WITH THIS SCENARIO TONIGHT... ALTHOUGH VERY MOIST ENVIRONMENT WILL ALLOW FOR EFFICIENT RAINFALL PRODUCTION. WIDESPREAD RAINFALL OF OVER ONE INCH ARE POSSIBLE WITH THE LEADING CONVECTIVE BAND AND TRAILING RAIN REGION. STORMS SHOULD MOVE OFF THE COAST AROUND MIDNIGHT... WITH CLEARING BEHIND IT. COULD SEE SOME FOG ESPECIALLY IF RAIN IS WIDESPREAD. HUMIDITY WILL KEEP TEMPERATURES IN THE UPPER 60S AND LOW 70S. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... COLD FRONT / OUTFLOW FROM OVERNIGHT CONVECTION WILL STALL AND WASH OUT OFFSHORE ON THURSDAY. MAY SEE A RETURN FLOW OF WARM/MOIST AIR INTO THE AREA WITH TEMPERATURES WARMING INTO THE UPPER 80S AND LOW 90S. DEW POINTS NEAR 70 WILL ALLOW HEAT INDEX VALUES TO RISE INTO THE UPPER 90S. DO NOT ANTICIPATE NEEDING A HEAT ADVISORY FOR THURSDAY AS THERE WILL NOT BE A LARGE AREA OF EXTENDED HEAT INDEX READINGS ABOVE 100. IF HIGHER DEW POINTS OR HIGHER TEMPERATURES ARE ACHIEVED... THEN THIS CRITERIA COULD BE MET. CONDITIONS WILL BE CLOSE TO ADVISORY CRITERIA... BUT CONSIDERING THAT THE HOT AND HUMID WEATHER HAS BEEN AROUND FOR SEVERAL WEEKS THIS SUMMER... DID NOT THINK A MARGINAL ADVISORY WAS NEEDED AS THE AWARENESS OF THE HOT AND HUMID WEATHER IS ALREADY HIGH. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE DURING THE AFTERNOON TOMORROW... PRIMARILY OVER THE SOUTHWESTERN HALF OF THE AREA WHERE BETTER INSTABILITY EXISTS. A SHORTWAVE TROUGH WILL ALSO ADD LIFT IN THIS AREA TO INCREASE THE CHANCE OF CONVECTION. ALTHOUGH WE CANNOT RULE OUT THE THREAT FOR DAMAGING WINDS WITH ANY STORMS THAT FORM... THE THREAT DOES NOT APPEAR WIDESPREAD. EXPECT SHOWERS AND THUNDERSTORMS TO DISSIPATE THURSDAY EVENING. ANOTHER HUMID NIGHT WILL KEEP TEMPERATURES IN THE UPPER 60S AND LOW 70S. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... 500 MB HEIGHTS RISE ON FRIDAY AS RIDGING BUILDS IN BRIEFLY...AND 850 TEMPS APPROACH 20 C. EXPECTING THIS BE ONE OF THE MORE HOT AND HUMID DAYS WE HAVE SEEN THIS SUMMER...AND HEAT INDEX VALUES WILL LIKELY REACH 100 IN PARTS OF THE SOUTHERN ZONES...AND A HEAT ADVISORY MAY BE NEEDED THERE. CANNOT RULE OUT A FEW AIR MASS THUNDERSTORMS...BUT BETTER CHANCE WILL BE IN NORTHERN ZONES...WHERE STRONGER WINDS ALOFT...AND APPROACHING COLD FRONT WILL CREATE BETTER DYNAMICS...AND COULD PRODUCE SOME STRONGER STORMS. LOOK FOR A WARM AND UNCOMFORTABLE NIGHT FRIDAY NIGHT AS HUMIDITIES REMAIN HIGH AND INCREASED SW FLOW PREVENTS MIN FROM DROPPING OFF MUCH. COLD FRONT WILL APPROACH NORTHERN ZONES LATE FRIDAY NIGHT...AND THE THREAT FOR THUNDERSTORMS WILL INCREASE TOWARD DAYBREAK...AND SHIFT SOUTHWARD TOWARD THROUGH THE DAY. GIVEN THE GREAT SURFACE INSTABILITY AND THE STRONG MID-UPPER LEVEL WINDS DROPPING SOUTHWARD AHEAD OF THE FRONT SATURDAY...THE THREAT FOR SEVERE CONVECTION REMAINS A CONCERN ON SATURDAY...AND THIS COULD LINGER INTO THE EVENING. THE FRONT IS EXPECTED TO CLEAR THE COAST LATE SATURDAY NIGHT OR EARLY SUNDAY...WITH CLEARING AND NOTICEABLY COOLER AND LESS HUMID CONDITIONS. THE HIGH THAT BUILDS IN BEHIND THE FRONT WILL LINGER INTO TUESDAY...WITH TEMPS CLOSE TO OR A LITTLE BELOW NORMAL DURING THIS PERIOD. AN INCREASE IN HUMIDITY AND TEMPS IS POSSIBLE BY MID-WEEK. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... SHORT TERM /THROUGH THURSDAY NIGHT/...SCATTERED WITH POSSIBLY MORE NUMEROUS SHOWERS AND THUNDERSTORMS MOVE THROUGH OVERNIGHT WITH POSSIBLE IFR CIG/VSBY...REACHING NW AREAS FIRST BY 00Z THEN ALONG THE COAST LAST...MOST LIKELY AFTER 02Z. SHOWERS AND THUNDERSTORMS END FROM NW TO SE FROM ROUGHLY 04Z TO 06Z. POSSIBLE SEVERE WX WITH THUNDERSTORMS WITH A SEVERE THUNDERSTORM WATCH IN EFFECT THROUGH MIDNIGHT ACROSS THE MOUNTAINS AND FOOTHILLS OF WESTERN MAINE AND ALL OF NEW HAMPSHIRE EXCEPT SOUTHEAST PORTIONS. VALLEY FOG WITH POSSIBLE IFR/LIFR CIG/VSBY FORMS OVERNIGHT MAINLY WHERE RAIN HAS FALLEN AND IN MORE FAVORABLE LOCATIONS. VFR THURSDAY AND THURSDAY NIGHT...EXCEPT LOWER IN SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. AGAIN...PATCHY FOG POSSIBLE THURSDAY NIGHT. LONG TERM...MAINLY VFR FRIDAY AND FRIDAY NIGHT...WITH FLIGHT RESTRICTIONS IS CONVECTION EXPECTED ON SATURDAY INTO SATURDAY EVENING. VFR RETURNS SUNDAY AND MONDAY. && .MARINE... SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...WILL UPDATE PER LATEST BUOY OBSERVATIONS. A FEW GUSTS UP TO 25 KT AT THIS TIME WILL CONTINUE THROUGH THE EVENING HOURS BUT WON'T BE FREQUENT ENOUGH TO WARRANT AN SCA. WINDS DROP OFF OVERNIGHT. WILL HOLD SEAS BELOW 5 FEET OVERNIGHT AS THEY TRY TO BUILD THIS EVENING BUT SLACKEN OFF OVERNIGHT AS WINDS LET UP. WINDS AND SEAS STAY BELOW SCA LEVELS THURSDAY AND THURSDAY NIGHT. LONG TERM...SW FLOW INCREASES AHEAD OF A COLD FRONT FRIDAY NIGHT INTO SATURDAY WITH SEAS IN EXCESS AROUND 5 FT...AND WINDS APPROACHING SCA LEVELS. WINDS WILL SHIFT TO NW SATURDAY NIGHT AND DIMINISH. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAY ME 651 PM EDT WED JUL 17 2013 MEZ007>009-012>014-NHZ001>009-182300- NORTHERN OXFORD-NORTHERN FRANKLIN-CENTRAL SOMERSET-SOUTHERN OXFORD- SOUTHERN FRANKLIN-SOUTHERN SOMERSET-NORTHERN COOS-SOUTHERN COOS- NORTHERN GRAFTON-NORTHERN CARROLL-SOUTHERN GRAFTON-SOUTHERN CARROLL- SULLIVAN-MERRIMACK-BELKNAP- 651 PM EDT WED JUL 17 2013 ...SEVERE THUNDERSTORM WATCH 418 IN EFFECT UNTIL MIDNIGHT EDT TONIGHT... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN MAINE...CENTRAL NEW HAMPSHIRE AND NORTHERN NEW HAMPSHIRE. .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. STRONG THUNDERSTORMS PRODUCING DAMAGING WINDS AND VERY HEAVY RAIN ARE POSSIBLE THIS EVENING IN WESTERN MAINE AND NEW HAMPSHIRE. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. THE COMBINATION OF HIGHS IN THE LOW TO MID 90S AND HIGH HUMIDITY LEVELS COULD PRODUCE HEAT INDICIES IN EXCESS OF 100 ON FRIDAY IN SOUTHERN NEW HAMPSHIRE AND SOUTHWEST MAINE. STRONG STORMS ARE POSSIBLE ON FRIDAY...BUT WILL BE LARGER THREAT ON SATURDAY AS A COLD FRONT DROPS SOUTH THROUGH THE REGION. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO CALL OR RADIO IN SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. MEZ018>028-NHZ010-013-014-182300- INTERIOR YORK-INTERIOR CUMBERLAND-ANDROSCOGGIN-KENNEBEC- INTERIOR WALDO-COASTAL YORK-COASTAL CUMBERLAND-SAGADAHOC-LINCOLN- KNOX-COASTAL WALDO-STRAFFORD-INTERIOR ROCKINGHAM-COASTAL ROCKINGHAM- 651 PM EDT WED JUL 17 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN MAINE...CENTRAL NEW HAMPSHIRE AND SOUTHEASTERN NEW HAMPSHIRE. .DAY ONE...TONIGHT. STRONG THUNDERSTORMS PRODUCING DAMAGING WINDS AND VERY HEAVY RAIN ARE POSSIBLE THIS EVENING IN WESTERN MAINE AND NEW HAMPSHIRE. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. THE COMBINATION OF HIGHS IN THE LOW TO MID 90S AND HIGH HUMIDITY LEVELS COULD PRODUCE HEAT INDICIES IN EXCESS OF 100 ON FRIDAY IN SOUTHERN NEW HAMPSHIRE AND SOUTHWEST MAINE. STRONG STORMS ARE POSSIBLE ON FRIDAY...BUT WILL BE LARGER THREAT ON SATURDAY AS A COLD FRONT DROPS SOUTH THROUGH THE REGION. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO CALL OR RADIO IN SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. ANZ150>154-182300- STONINGTON ME TO PORT CLYDE ME OUT TO 25 NM-PENOBSCOT BAY- PORT CLYDE ME TO CAPE ELIZABETH ME OUT TO 25 NM-CASCO BAY- CAPE ELIZABETH ME TO MERRIMACK RIVER MA OUT TO 25 NM- 651 PM EDT WED JUL 17 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CASCO BAY...PENOBSCOT BAY...THE COASTAL WATERS FROM CAPE ELIZABETH ME TO MERRIMACK RIVER MA...THE COASTAL WATERS FROM PORT CLYDE ME TO CAPE ELIZABETH ME AND THE COASTAL WATERS FROM STONINGTON ME TO PORT CLYDE ME. .DAY ONE...TONIGHT. THUNDERSTORMS PRODUCING STRONG WINDS ARE POSSIBLE THIS EVENING. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. STRONG THUNDERSTORMS ARE POSSIBLE AGAIN ON SATURDAY. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO CALL OR RADIO IN SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
The Portland,ME radar (KGYX), 59 km away, was scanning. The volume nearest the first event began at 00:11 UTC.
2 thunderstorm wind. Local standard time, as filed.
A severe thunderstorm downed numerous trees in Whitefield.
A severe thunderstorm downed two trees across a road in Skowhegan.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Maine in 2013Every state in 2013This day in weather historyWarnings in Maine, July 2013
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: 469447, 469448.