Prevailing westerly steering flow combined with a moist and unstable airmass produced scattered strong to severe afternoon and evening storms.
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 JAX wrote it up.
Prevailing westerly steering flow combined with a moist and unstable airmass produced scattered strong to severe afternoon and evening storms.
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 Jacksonville, FL wrote its last area forecast discussion before the first event at Aug 20, 2:20 PM EST, 2 hours 25 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 320 PM EDT THU AUG 20 2015 .NEAR TERM /THROUGH FRIDAY/... THIS AFTERNOON...SCATTERED SHOWERS AND STORMS WERE DEVELOPING ACROSS SOUTHEAST GEORGIA AND JUST TO THE WEST OF I-75 EARLY THIS AFTERNOON. THE EAST COAST SEA BREEZE WAS BEGINNING TO MOVE INLAND...AND SHOWERS AND STORMS WILL BECOME MORE NUMEROUS THROUGH THE AFTERNOON. THE WARMER TEMPERATURES ALOFT HAVE KEPT THUNDERSTORMS IN CHECK THUS FAR...BUT STRONG TO ISOLATED SEVERE STORMS WITH DOWNBURST WINDS ARE POSSIBLE. TONIGHT...SHOWERS AND A FEW STORMS COULD CONTINUE WELL INTO THE EVENING HOURS...ESPECIALLY ACROSS THE SOUTHEAST GEORGIA COUNTIES AS A SHORTWAVE ROTATES AROUND THE NORTHERN SIDE OF THE UPPER RIDGE ACROSS THE NORTHEASTERN GULF AND A SURFACE FRONT PUSHES TOWARDS THE REGION. PATCHY FOG IS POSSIBLE...ESPECIALLY ACROSS AREAS THAT RECEIVE RAIN THIS AFTERNOON/EVENING. LOWS WILL BE IN THE LOW TO MID 70S. FRIDAY...UPPER LEVEL TROUGH ACROSS THE GREAT LAKES THIS AFTERNOON WILL PUSH NORTHEASTWARD INTO CANADA. MID/UPPER LEVEL HIGH PRESSURE WILL REMAIN ALMOST STATIONARY ACROSS NORTH CENTRAL FLORIDA AND THE EASTERN GULF ON FRIDAY...WITH WESTERLY FLOW CONTINUING ALOFT. A SURFACE FRONTAL BOUNDARY WILL PUSH INTO SOUTHEAST GEORGIA TO NEAR STATE ROAD 84 ON FRIDAY...WHICH WILL BRING NORTHERLY WINDS AND SLIGHTLY DRIER AIR BEHIND THE BOUNDARY. DEEP MOISTURE WILL REMAIN ACROSS NORTHEAST FLORIDA. LOW LEVEL CONVERGENCE/SEA BREEZES BOUNDARIES AND DAYTIME HEATING WILL LEAD TO SCATTERED SHOWERS/STORMS ACROSS THE REGION...WITH NUMEROUS COVERAGE WEST OF I-95 TO THE I-75 CORRIDOR SOUTH OF JAX. HIGHS WILL BE IN THE LOWER TO MID 90S WITH HEAT INDICES UP TO 105. .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... A WEAK SURFACE TROUGH WILL DROP SOUTH THROUGH THE AREA FRIDAY NIGHT. A FEW DIURNAL STORMS MAY LINGER INTO THE EVENING WITH A FOCUS ALONG THIS BOUNDARY. STORMS SHOULD WIND DOWN COMPLETELY BY MIDNIGHT. LIGHT ONSHORE FLOW WILL DEVELOP ON SATURDAY BEHIND THE DECAYING SURFACE BOUNDARY. MOISTURE AND INSTABILITY WILL REMAIN SUFFICIENT ENOUGH FOR SCATTERED TO NUMEROUS AFTERNOON THUNDERSTORMS TO DEVELOP ALONG THE SEABREEZES. THE MAIN FOCUS WILL BE ACROSS THE INTERIOR COUNTIES MAINLY BETWEEN I-95 AND I-75. HOT CONDITIONS WILL CONTINUE ON SATURDAY OVER INLAND LOCATIONS WITH HIGHS IN THE MID 90S FOR MOST INLAND ZONES. THE MID TO UPPER LEVEL RIDGE WILL BEGIN TO GET SUPPRESSED ON SUNDAY AS SHORTWAVE TROUGHING PUNCHES IN FROM THE NORTH. THE LOW LEVEL FLOW WILL BE A LITTLE STRONGER SO THE ATLANTIC SEABREEZE WILL GET OFF TO AN EARLIER START. A LITTLE DRIER AIR ALOFT WILL ALSO BEGIN ADVECTING INTO THE REGION. THIS WILL TRANSLATE TO A LITTLE LESS THUNDERSTORM ACTIVITY BUT WE WILL STILL SEE SCATTERED INLAND STORMS SUNDAY AFTERNOON ESPECIALLY NEAR THE I-75 CORRIDOR AS THE TWO SEABREEZES COME TOGETHER. LITTLE IF ANY RAIN IS EXPECTED AT THE ATLANTIC COAST ON SUNDAY. .LONG TERM /MONDAY THROUGH THURSDAY/... THE FLOW WILL BECOME MORE SOUTHERLY EARLY NEXT WEEK AS DEEP LAYER TROUGHING BECOMES ESTABLISHED ACROSS THE SOUTHEAST UNITED STATES. INITIALLY...THIS WILL KEEP DIURNAL STORMS MORE SCATTERED SINCE SOME THE TROUGH WILL USHER IN SOME DRIER AIR ALOFT. BUT AS WE GO THROUGH THE WEEK...STORM CHANCES WILL AGAIN BEGIN TO INCREASE AS A SURFACE TROUGH SETS UP ACROSS SE GA WITH INCREASING MOIST SOUTHWEST FLOW ACROSS NE FL BRINGING STORM COVERAGE BACK UP TO SCATTERED TO NUMEROUS. && AVIATION... SCATTERED SHOWERS AND STORMS WILL BECOME NUMEROUS ACROSS NORTHEAST FLORIDA EAST OF I-75 THIS AFTERNOON...AND TEMPO FOR MVFR HAS BEEN ADDED TO THE FLORIDA TAF SITES FROM 20-23Z. SHOWERS AND STORMS WILL DISSIPATE OVERNIGHT...WITH MAINLY LIGHT AND VARIABLE WINDS THROUGH THE END OF THE TAF PERIOD. && .MARINE... HIGH PRESSURE RIDGE WILL BREAK DOWN FRIDAY AND SATURDAY AS A WEAK FRONT PUSHES INTO SOUTHEAST GEORGIA AND THEN DISSIPATES. PREVAILING LIGHT ONSHORE FLOW SHOULD BEGIN BY SAT...CONTINUING THROUGH SUN NIGHT. NO HEADLINES AT THIS TIME. ANOTHER FRONT APPROACHES FROM THE NW ON TUE. RIP CURRENTS: LOW RISK THROUGH FRIDAY. && .PRELIMINARY POINT TEMPS/POPS... AMG 76 95 74 95 / 30 40 20 50 SSI 76 89 78 90 / 30 40 20 40 JAX 75 92 75 92 / 30 50 30 50 SGJ 75 89 77 90 / 30 40 20 40 GNV 72 92 75 93 / 20 50 20 60 OCF 75 92 74 93 / 20 50 20 60 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && KENNEDY/HESS/SHULER
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE JACKSONVILLE FL 500 AM EDT THU AUG 20 2015 AMZ450-452-454-470-472-474-FLZ020>025-030>033-035>038-040-124-125- GAZ132>136-149>154-162>166-210930- COASTAL WATERS FROM ALTAMAHA SOUND TO FERNANDINA BEACH FL OUT 20 NM- COASTAL WATERS FROM FERNANDINA BEACH TO ST. AUGUSTINE FL OUT 20 NM- COASTAL WATERS FROM ST. AUGUSTINE TO FLAGLER BEACH FL OUT 20 NM- WATERS FROM ALTAMAHA SOUND GA TO FERNANDINA BEACH FL FROM 20 TO 60 NM- WATERS FROM FERNANDINA BEACH TO ST. AUGUSTINE FL FROM 20 TO 60 NM- WATERS FROM ST. AUGUSTINE TO FLAGLER BEACH FL FROM 20 TO 60 NM- HAMILTON-SUWANNEE-COLUMBIA-BAKER-INLAND NASSAU-INLAND DUVAL-UNION- BRADFORD-CLAY-ST. JOHNS-GILCHRIST-ALACHUA-PUTNAM-FLAGLER-MARION- COASTAL NASSAU-COASTAL DUVAL-COFFEE-JEFF DAVIS-BACON-APPLING- WAYNE-ATKINSON-WARE-PIERCE-BRANTLEY-INLAND GLYNN-COASTAL GLYNN- ECHOLS-CLINCH-CHARLTON-INLAND CAMDEN-COASTAL CAMDEN- 500 AM EDT THU AUG 20 2015 ...SCATTERED TO NUMEROUS STORMS AGAIN TODAY... THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST FLORIDA... SOUTHEAST GEORGIA AND THE ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT... SCATTERED TO NUMEROUS THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND EVENING...WITH THE HIGHEST CHANCES OVER NORTHEAST FLORIDA. A FEW STRONG TO BRIEFLY SEVERE STORMS WILL BE POSSIBLE THIS AFTERNOON WITH STRONG GUSTY WINDS AND FREQUENT LIGHTNING. LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE. SHOWERS AND STORMS WILL BEGIN WELL INLAND BY 1 PM...AND MOVE TO THE I-95 CORRIDOR AREA AROUND 4 PM. STORM MOTION WILL BE EAST AT 10 TO 15 MPH. MOST OF THE THUNDERSTORM ACTIVITY SHOULD DISSIPATE BY THE MID EVENING HOURS. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY... SCATTERED TO NUMEROUS THUNDERSTORMS ARE EXPECTED FRIDAY WITH THE BEST COVERAGE OVER NORTHEAST FLORIDA. THERE WILL REMAIN A CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS OVER THE WEEKEND AND EARLY NEXT WEEK. LIGHTNING AND HEAVY RAINFALL WILL BE THE MAIN STORM THREATS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS REQUESTED IF WARNINGS ARE ISSUED LATER TODAY. FOR ADDITIONAL INFORMATION...VISIT THE NATIONAL WEATHER SERVICE IN JACKSONVILLE WEBSITE ON THE INTERNET AT WEATHER.GOV/JAX.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE JACKSONVILLE FL 421 PM EDT THU AUG 20 2015 FLZ023-030-031-GAZ164-202045- BAKER FL-BRADFORD FL-UNION FL-CHARLTON GA- 421 PM EDT THU AUG 20 2015 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN UNION...NORTHEASTERN BRADFORD...EASTERN BAKER AND SOUTH CENTRAL CHARLTON COUNTIES UNTIL 445 PM EDT... AT 421 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR SANDERSON...OR 12 MILES NORTH OF RAIFORD...MOVING EAST AT 30 MPH. GUSTY WINDS OF 40 TO 50 MPH CAN BE EXPECTED ALONG WITH POSSIBLE MINOR WIND DAMAGE. LOCATIONS IMPACTED INCLUDE... LAKE BUTLER...RAIFORD...TAYLOR...MACCLENNY...GLEN ST. MARY... SANDERSON...JOHNSTOWN AND ELLERBEE. PRECAUTIONARY/PREPAREDNESS ACTIONS... REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY EMERGENCY MANAGEMENT. LAT...LON 3054 8233 3056 8205 3009 8205 3000 8234 TIME...MOT...LOC 2021Z 251DEG 26KT 3025 8222 ZIBURA
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
450 PM EDT THU AUG 20 2015
FLZ023>025-031-032-036-037-GAZ164-202130-
INLAND NASSAU FL-ALACHUA FL-BAKER FL-BRADFORD FL-INLAND DUVAL FL-
CLAY FL-PUTNAM FL-CHARLTON GA-
450 PM EDT THU AUG 20 2015
...SIGNIFICANT WEATHER ADVISORY FOR EASTERN BRADFORD...EASTERN
BAKER...WESTERN CLAY...SOUTHWESTERN DUVAL...SOUTHWESTERN NASSAU...
NORTHWESTERN PUTNAM...EAST CENTRAL ALACHUA AND SOUTHEASTERN CHARLTON
COUNTIES UNTIL 530 PM EDT...
AT 450 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM
OVER ST. GEORGE...OR 13 MILES WEST OF CALLAHAN...MOVING NORTHEAST AT
30 MPH.
EXCESSIVE CLOUD-TO-GROUND LIGHTNING AND GUSTY WINDS OF 45 TO 55 MPH
CAN BE EXPECTED ALONG WITH POSSIBLE MINOR DAMAGE.
LOCATIONS IMPACTED INCLUDE...
STARKE...KEYSTONE HEIGHTS...MIDDLEBURG...MELROSE...MACCLENNY...GLEN
ST. MARY...KINGSLEY...GEORGE'S LAKE...MAXVILLE...BRYCEVILLE...OAKLEAF
PLANTATION...FLORAHOME...CAMP BLANDING...LAKE GENEVA...ORANGE
HEIGHTS...CECIL FIELD...ST. GEORGE...BALDWIN...PENNEY FARMS AND
LAWTEY.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY
EMERGENCY MANAGEMENT.
TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.
&&
LAT...LON 2969 8181 2966 8214 3007 8218 3013 8214
3014 8214 3015 8219 3057 8224 3057 8222
3058 8221 3060 8187
TIME...MOT...LOC 2050Z 240DEG 34KT 3049 8205
ZIBURASPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
505 PM EDT THU AUG 20 2015
FLZ040-202145-
MARION FL-
505 PM EDT THU AUG 20 2015
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN MARION COUNTY UNTIL
545 PM EDT...
AT 505 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM OVER
LYNNE...MOVING NORTHEAST AT 10 MPH.
EXCESSIVE CLOUD-TO-GROUND LIGHTNING AND GUSTY WINDS OF 40 TO 50 MPH
CAN BE EXPECTED ALONG WITH POSSIBLE MINOR DAMAGE.
LOCATIONS IMPACTED INCLUDE...
JUNIPER SPRINGS...LYNNE...SALT SPRINGS...MOSS BLUFF...SILVER SPRINGS
SHORES AND BURBANK.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY
EMERGENCY MANAGEMENT.
TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.
&&
LAT...LON 2935 8202 2938 8186 2935 8167 2934 8167
2934 8168 2932 8168 2930 8166 2907 8164
2907 8199
TIME...MOT...LOC 2105Z 223DEG 10KT 2921 8192
ZIBURASPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
519 PM EDT THU AUG 20 2015
FLZ024-025-032-033-124-125-GAZ166-202200-
COASTAL DUVAL FL-INLAND NASSAU FL-COASTAL NASSAU FL-INLAND DUVAL FL-
CLAY FL-ST. JOHNS FL-COASTAL CAMDEN GA-
519 PM EDT THU AUG 20 2015
...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN CLAY...CENTRAL
DUVAL...NORTHEASTERN NASSAU AND NORTHWESTERN ST. JOHNS COUNTIES UNTIL
600 PM EDT...
AT 519 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM OVER
BELLAIR-MEADOWBROOK TERRACE...OR OVER ORANGE PARK...MOVING NORTHEAST
AT 35 MPH.
GUSTY WINDS OF 40 TO 50 MPH CAN BE EXPECTED ALONG WITH POSSIBLE
MINOR WIND DAMAGE.
LOCATIONS IMPACTED INCLUDE...
JACKSONVILLE...ST. MARYS...KINGSLAND...ORANGE PARK...GREEN COVE
SPRINGS...CALLAHAN...JACKSONVILLE INTERNATIONAL ARPT...FRUIT COVE...
MANDARIN...ARLINGTON...YULEE...ORTEGA...SAN MARCO...RIVERSIDE...
SWITZERLAND...FLEMING ISLAND...RATLIFF...NAS JAX...NASSAU
VILLAGE-RATLIFF AND LAKESIDE.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY
EMERGENCY MANAGEMENT.
TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.
&&
LAT...LON 2984 8179 2983 8182 3073 8187 3076 8174
3074 8172 3075 8169 3077 8169 3079 8158
3073 8158 3072 8160 3072 8157 2997 8152
TIME...MOT...LOC 2119Z 245DEG 32KT 3020 8172
ZIBURAPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
537 PM EDT THU AUG 20 2015
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0525 PM TSTM WND GST 5 NNW MANDARIN 30.22N 81.67W
08/20/2015 M0 MPH DUVAL FL ASOS
MEASURED WIND GUST OF 40 MPH AT JACKSONVILLE NAS.
&&
COMBSSPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
539 PM EDT THU AUG 20 2015
GAZ166-202230-
COASTAL CAMDEN GA-
539 PM EDT THU AUG 20 2015
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN CAMDEN COUNTY UNTIL
630 PM EDT...
AT 538 PM EDT...DOPPLER RADAR WAS TRACKING A LINE OF STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM 9 MILES SOUTHWEST OF JEKYLL
ISLAND TO NEAR KINGSLAND...AND MOVING EAST AT 20 MPH.
HAIL UP TO NICKEL SIZE IN DIAMETER AND GUSTY WINDS OF 40 TO 50 MPH
CAN BE EXPECTED.
LOCATIONS IMPACTED INCLUDE...
ST. MARYS...KINGSLAND...KINGS BAY BASE...CUMBERLAND ISLAND AND
HARRIETTS BLUFF.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY
EMERGENCY MANAGEMENT.
THESE STORMS MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.
LAT...LON 3076 8146 3075 8147 3085 8148 3087 8155
3083 8149 3084 8151 3081 8153 3081 8152
3083 8151 3076 8149 3075 8169 3085 8166
3101 8153 3103 8146 3091 8148 3093 8143
3098 8141 3092 8140
TIME...MOT...LOC 2138Z 262DEG 16KT 3095 8150 3076 8168
WALSHThe Jacksonville radar (KJAX), 38 km away, was scanning. The volume nearest the first event began at 21:45 UTC.
2 thunderstorm wind, 1 heavy rain. Local standard time, as filed.
Multiple large tree limbs were blown down in the Laurel Island and Lakes Subdivisions. The time of damage was based on radar.
Multiple large tree limbs and wires were blown down in the Sugarmill Subdivision. The time of damage was based on radar.
A storm total accumulation of 2.61 was reported.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Georgia in 2015Every state in 2015This day in weather historyWarnings in Georgia, August 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: 598961, 598962, 598960.