Stronger vertical wind shear and cool temperatures aloft increased the potential for strong to severe storms forming along the sea breezes and outflow boundaries over a moist and unstable air mass in the afternoon.
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.
Stronger vertical wind shear and cool temperatures aloft increased the potential for strong to severe storms forming along the sea breezes and outflow boundaries over a moist and unstable air mass in the afternoon.
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 19, 2:59 PM EST, 1 hour 41 minutes earlier.
Area Forecast Discussion National Weather Service Jacksonville FL 359 PM EDT Wed Aug 19 2020 ...LOCALLY HEAVY RAINFALL WITH STRONG TO SEVERE STORMS POSSIBLE THROUGH SATURDAY... .NEAR TERM [Tonight through Thursday]...Active weather pattern continues with cooler than normal temperature aloft as strong upper trough amplifies over the western Gulf region. An increasing southwest flow on the east side of the trough will produce more organized convection on Thursday as vertical speed shear increases. Strong to severe storms will be possible along with locally heavy rainfall. Strong gusty winds, frequent lightning and hail will be possible Thursday afternoon/evening. .SHORT TERM [Thursday night through Saturday night]...The chance for numerous showers and thunderstorms will continue through the period. The ingredients for strong to severe storms with locally heavy rainfall will persist. The relatively strong vertical shear may keep areas of organized convection going during the overnight and morning hours. .LONG TERM [Sunday Through Wednesday]...Subtropical high pressure ridge will build into the area from the east with upper trough to the west lifting off the ne. This will decrease the shear and shift the steering flow to the south this weekend and southeast early next week. Temperatures will warm aloft with moisture levels remaining high. The severe potential will be lower with a continued threat of locally heavy rainfall mainly over inland areas as afternoon convection develops and moves westward. A tropical low/trough now located east of the windward islands will move to the wnw the next few days and will be monitored for any possible development into next week. && .MARINE...High pressure ridge axis to the south will lift to the north of the local waters this weekend. A light south to southwest flow will become southeast this weekend into early next week. A long period swell will continue the next few days with periods around 10 seconds. Numerous late day showers and thundestorms will continue through Saturday. && .HYDROLOGY...Locally heavy rainfall from numerous showers and thunderstorms the next several afternoons may result in localized flooding especially in urban areas. && .PRELIMINARY POINT TEMPS/POPS... AMG 70 88 71 87 70 / 30 40 30 70 40 SSI 75 88 76 87 75 / 40 40 40 60 40 JAX 72 91 73 90 73 / 30 60 40 70 40 SGJ 72 89 74 89 74 / 40 70 50 60 40 GNV 71 89 71 87 72 / 40 50 50 70 50 OCF 71 89 72 88 73 / 30 60 50 70 50 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. &&
Special Weather Statement
National Weather Service Jacksonville FL
420 PM EDT Wed Aug 19 2020
FLZ020-021-192100-
Hamilton FL-Suwannee FL-
420 PM EDT Wed Aug 19 2020
...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN SUWANNEE AND
HAMILTON COUNTIES UNTIL 500 PM EDT...
* At 420 PM EDT, National Weather Service meteorologists were
tracking a strong thunderstorm near Crossroads, or 7 miles
southwest of Jasper, moving northeast at 10 mph.
* Winds in excess of 45 mph and minor flooding due to heavy rainfall
is possible with this storm.
* Locations impacted include...
Jasper, Jennings, Suwannee Springs, Suwannee River State Park, Blue
Springs and Crossroads.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
These winds can down small tree limbs and branches, and blow around
unsecured small objects. Seek shelter in a safe building until the
storm passes.
Torrential rainfall is occurring with this storm, and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
To report severe weather, contact your nearest law enforcement
agency. You can also share your report with NWS Jacksonville on
Facebook and Twitter.
&&
LAT...LON 3062 8307 3061 8283 3060 8281 3045 8271
3032 8318 3035 8321 3035 8319 3038 8319
3039 8317 3041 8318 3042 8322 3046 8322
3047 8323 3047 8324 3051 8324
TIME...MOT...LOC 2020Z 232DEG 8KT 3045 8305
AKPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
423 PM EDT WED AUG 19 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0330 PM WATER SPOUT 3 S BRUNSWICK 31.12N 81.48W
08/19/2020 AMZ450 GA PARK/FOREST SRVC
WATERSPOUT OVER SIDNEY LANIER BRIDGE. VIDEO
OF WATERSPOUT ON GEORGIA DNR SOCIAL MEDIA.
&&
KCPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
425 PM EDT WED AUG 19 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0330 PM WATER SPOUT 3 S BRUNSWICK 31.12N 81.48W
08/19/2020 AMZ450 GA PARK/FOREST SRVC
CORRECTS PREVIOUS WATER SPOUT REPORT FROM 3
S BRUNSWICK. WATERSPOUT OVER SIDNEY LANIER
BRIDGE. VIDEO OF WATERSPOUT ON GEORGIA DNR
SOCIAL MEDIA. NO PEOPLE OR PROPERTY WERE
HARMED.
&&
KCSpecial Weather Statement
National Weather Service Jacksonville FL
427 PM EDT Wed Aug 19 2020
FLZ033-133-192115-
Coastal St. Johns FL-Inland St. Johns FL-
427 PM EDT Wed Aug 19 2020
...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL ST. JOHNS COUNTY UNTIL
515 PM EDT...
* At 426 PM EDT, National Weather Service meteorologists were
tracking a strong thunderstorm over World Golf Village, or 9 miles
southeast of Fruit Cove, moving east at 15 mph.
* Winds in excess of 45 mph and minor flooding due to heavy rainfall
is possible with this storm.
* Locations impacted include...
Saint Augustine, World Golf Village, Saint Augustine Beach,
Nocatee, South Ponte Vedra, Durbin, Vilano Beach, Guana River State
Park, Saint Augustine South and Anastasia.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
These winds can down small tree limbs and branches, and blow around
unsecured small objects. Seek shelter in a safe building until the
storm passes.
Torrential rainfall is occurring with this storm, and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
To report severe weather, contact your nearest law enforcement
agency. You can also share your report with NWS Jacksonville on
Facebook and Twitter.
&&
LAT...LON 2985 8126 2986 8159 3010 8153 3011 8144
3016 8144 3016 8132 2995 8124
TIME...MOT...LOC 2026Z 266DEG 13KT 3002 8149
AKSpecial Weather Statement
National Weather Service Jacksonville FL
522 PM EDT Wed Aug 19 2020
FLZ033-038-133-192215-
Coastal St. Johns FL-Inland Flagler FL-Inland St. Johns FL-
522 PM EDT Wed Aug 19 2020
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN ST. JOHNS COUNTY
UNTIL 615 PM EDT...
* At 522 PM EDT, National Weather Service meteorologists were
tracking a strong thunderstorm near Hastings, moving east at 15
mph.
* Small hail, winds in excess of 45 mph, and minor flooding due to
heavy rainfall is possible with this storm.
* Locations impacted include...
Saint Augustine, Hastings, Saint Augustine Beach, Marineland,
Crescent Beach, Saint Augustine Shores, Butler Beach, Saint
Augustine South, Spuds and Anastasia.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
These winds can down small tree limbs and branches, and blow around
unsecured small objects. Seek shelter in a safe building until the
storm passes.
Torrential rainfall is occurring with this storm, and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
To report severe weather, contact your nearest law enforcement
agency. You can also share your report with NWS Jacksonville on
Facebook and Twitter.
&&
LAT...LON 2964 8120 2967 8121 2965 8122 2964 8122
2965 8123 2966 8123 2966 8125 2967 8126
2965 8128 2964 8127 2963 8152 2988 8151
2993 8124 2964 8114
TIME...MOT...LOC 2122Z 266DEG 12KT 2977 8143
AKPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
526 PM EDT WED AUG 19 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0517 PM HAIL ELKTON 29.78N 81.43W
08/19/2020 E0.25 INCH ST. JOHNS FL STORM CHASER
PEA SIZE HAIL ALONG STATE ROAD 207 NEAR
ELKTON.
&&
KCThe Jacksonville radar (KJAX), 82 km away, was scanning. The volume nearest the first event began at 21:38 UTC.
1 thunderstorm wind. Local standard time, as filed.
Tree limbs were blown down along County Road 305. The cost of damage was unknown but estimated for inclusion in Storm Data.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Florida in 2020Every state in 2020This day in weather historyWarnings in Florida, August 2020
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: 907741.