Alert archive / Florida / Severe Thunderstorm Warnings in 2017
Severe Thunderstorm Warning 277, NWS Jacksonville, FL
NWS Jacksonville, FL issued this severe thunderstorm warning at Aug 31, 2017, 6:43 PM EDT for Clay County, Putnam County, Saint Johns County, Florida. It was in force for 32 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Aug 31, 2017, 6:43 PM EDT (22:43 UTC)
- Expired
- Aug 31, 2017, 7:15 PM EDT
- In force
- 32 min
- Issued by
- NWS Jacksonville, FL
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Clay County, FL, Putnam County, FL, Saint Johns County, FL
The radar
The Jacksonville radar (KJAX), 72 km from the middle of the area, began a volume at 22:43 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Jacksonville, FL (KJAX), launched 12:00Z, 10.7 hours before the alert went out and 74 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 1403 J/kg
- Mixed-layer CIN
- -24 J/kg
- Mixed-layer LCL
- 744 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 49 m²/s²
- 0-3 km storm-relative helicity
- 72 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.4
What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, 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 this severe thunderstorm warning went out at Aug 31, 3:09 PM EDT, 3 hours 34 minutes earlier.
Area forecast discussion, Aug 31, 3:09 PM EDT, 3 hours 34 minutes before
Area Forecast Discussion National Weather Service Jacksonville FL 309 PM EDT Thu Aug 31 2017 ...Isolated Severe Storms Today and Friday, mainly across Southeast Georgia... .NEAR TERM /Tonight-Friday/... Rest of this Afternoon/Evening...Broken squall line with strong storms and isolated severe storms expected to cross through inland SE GA with the best threat of Severe Storms mainly North and West of Waycross. The line is expected to weaken early this evening but may still see some strong storms closer to the I-95 and US-301 corridors as remaining storms/outflows collide with Atlc Coast Sea Breeze front pushing inland. These storms will continue until late evening then fade around midnight as they push into the Atlc Ocean. Main threat this evening is damaging winds across inland SE GA but strong gusty winds are possible in any storm activity. Isolated Large Hail or a tornado cannot be ruled out in bowing segments...mainly across SE GA or in sea breeze/storm interactions. Locally heavy rainfall possible across SE GA as training of cells possible but antecedent conditions relatively drier so not expecting significant flooding threat. Overnight...Diurnal activity basically ends by midnight with fair skies/convective debris clouds and partly cloudy skies although the strong SW steering flow could produce some storm activity across the Big Bend region of the NE Gomex that could trickle into the I-75 corridor of inland North Florida towards morning but should be weakening and isolated the further it tracks inland. Muggy overnight lows in the mid/upper 70s expected. Friday...Band of deeper moisture in the SW steering flow steps just a bit further Eastward and is located from the Big Bend region across North Florida and SE GA. This will set up slightly better chances of rainfall area-wide with Pops generally 50-70% and with moisture source much closer, expect an earlier start to convection during the late morning hours as it won't take as much heating to kick off convection with PWATS much closer to 2 inches. The earlier start to convection will hold max temps closer to 90 degrees with heat indices in the 100-105 range. The strong belt of SW winds aloft will still support scattered strong and isolated severe storms with main threat of strong/damaging winds in a few storms. Also the higher PWATs will support a better chance of locally heavy rainfall, especially if some of the SW-NE oriented bands don't have enough Eastward translation during peak heating tomorrow and will need to watch for minor/localized flooding from isolated areas that pick up a quick 2-3 inches of rainfall. .SHORT TERM...Friday night through Sunday night...Trailing moisture axis associated with remnants of Harvey will still be across se Ga/ne Fl on Saturday. Daytime heating and a moderate sw flow with adequate shear will likely mean another round of strong to severe storms Saturday aftn/eve. Troughing aloft will lift to the ne on Sunday which will mean lighter winds and less shear for our area. Storms will be more scattered with best coverage over inland areas near the seabreeze collision. Temperatures will be near average with above average pops Saturday and near average Sunday. .LONG TERM...Monday through Thursday...A lighter sw flow will be across the area Monday and Tuesday with a mid-upper level ridge building across s Fl. Moisture will still be abundant so expect scattered diurnal seabreeze storms with best coverage over inland areas. Upper trough amplifies over the eastern U.S. Wednesday into Thursday which will push a cold front into the area on Thursday. GFS/GEFS continues to be more aggresive moving this system eastward than the ECMWF. Storms should become numerous Wednesday into Thursday for parts of the area with either solution. Temperatures will be be close to average through the period. Pops will be near average Monday and Tuesday...and at or above average Wednesday and Thursday. && .AVIATION... Still expecting a few scattered showers/storms to impact the TAF sites in the 21z-01z time frame and have upped to VCTS at all TAF sites and may need to add TEMPO groups if the broken squall line reaches all the way to the I-95 corridor/TAF sites. Some gusty winds to 30-40 knots and MVFR CIGS/VSBYS are possible if the line holds together. && .MARINE... South to Southwest flow will continue at 10-15 knots with seas 2-5 ft and no headlines into the weekend. Main impacts will be offshore moving storms Today-Friday with gusty winds possible. Weak frontal boundary/wind shift will be possible late in the weekend and early next week with winds becoming more light and variable at 10 knots or less and seas 1-3 ft or less from Sunday through Tuesday. Rip Currents: Moderate Risk continues in the lingering onshore swell. && .PRELIMINARY POINT TEMPS/POPS... AMG 74 90 73 88 / 20 40 20 60 SSI 78 89 77 85 / 40 60 40 60 JAX 76 92 75 88 / 40 50 30 50 SGJ 77 91 76 87 / 40 70 30 50 GNV 75 91 74 87 / 30 50 30 50 OCF 75 91 74 88 / 30 70 30 50 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && Hess/Zibura/McGinnis
Hazardous weather outlook, Aug 31, 1:45 PM EDT, 4 hours 58 minutes before
Hazardous Weather Outlook National Weather Service Jacksonville FL 145 PM EDT Thu Aug 31 2017 AMZ450-452-454-470-472-474-FLZ020>025-030>033-035>038-040-124-125- GAZ132>136-149>154-162>166-010745- 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- 145 PM EDT Thu Aug 31 2017 ...SLIGHT RISK OF SEVERE STORMS ACROSS SOUTHEAST GEORGIA TODAY... This Hazardous Weather Outlook is for Northeast Florida, Southeast Georgia and the Adjacent Coastal Waters. .DAY ONE...Today and Tonight... Heat indices 102 to 107 degrees across northeast Florida. Moderate risk of rip currents. Chance for afternoon and evening thunderstorms, especially across southeast Georgia and eastern half of northeast Florida. A slight risk of severe storms is possible across Southeast Georgia with damaging winds the main threat although locally heavy rainfall, hail and an isolated tornado is possible. Strong storms will be possible across Northeast Florida and capable of producing gusty winds, frequent lightning and locally heavy rainfall. .DAYS TWO THROUGH SEVEN...Friday through Wednesday... Scattered to numerous mainly afternoon thunderstorms each day capable of producing gusty winds and locally heavy rainfall. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed. For additional information, visit the National Weather Service in Jacksonville website on the internet at weather.gov/jax.
In the hours before
Special weather statement, Aug 31, 6:04 PM EDT, 39 minutes before
Special Weather Statement
National Weather Service Jacksonville FL
604 PM EDT THU AUG 31 2017
FLZ025-033-125-312230-
Inland Duval FL-St. Johns FL-Coastal Duval FL-
604 PM EDT THU AUG 31 2017
...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN ST. JOHNS AND
SOUTHEASTERN DUVAL COUNTIES UNTIL 630 PM EDT...
At 604 PM EDT, Doppler radar was tracking a strong thunderstorm over
Switzerland, or over Fruit Cove, moving northeast at 20 mph.
Excessive cloud-to-ground lightning and wind gusts up to 45 mph can
be expected.
Locations impacted include...
Unf, Fruit Cove, Baymeadows, Nocatee, Bayard and Durbin.
LAT...LON 2998 8163 3000 8165 3028 8158 3028 8144
3004 8143
TIME...MOT...LOC 2204Z 238DEG 15KT 3008 8164
ELSENHEIMERSpecial weather statement, Aug 31, 6:06 PM EDT, 37 minutes before
Special Weather Statement
National Weather Service Jacksonville FL
606 PM EDT THU AUG 31 2017
GAZ136-152-153-312230-
Inland Glynn GA-Brantley GA-Wayne GA-
606 PM EDT THU AUG 31 2017
...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN GLYNN...NORTHEASTERN
BRANTLEY AND SOUTHERN WAYNE COUNTIES UNTIL 630 PM EDT...
At 605 PM EDT, Doppler radar was tracking a strong thunderstorm near
Raybon, or 10 miles northeast of Nahunta, moving northeast at 40 mph.
Excessive cloud-to-ground lightning and wind gusts of 45 to 55 mph
can be expected along with possible minor damage.
Locations impacted include...
Gardi, Everett, Broadhurst, Mount Pleasant and Hortense.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 3158 8170 3156 8170 3154 8168 3154 8167
3153 8167 3153 8165 3151 8166 3149 8164
3148 8162 3147 8161 3145 8163 3144 8161
3143 8161 3137 8154 3127 8199 3131 8199
3131 8201 3143 8205 3159 8172
TIME...MOT...LOC 2205Z 244DEG 34KT 3134 8190
NELSONSpecial weather statement, Aug 31, 6:11 PM EDT, 32 minutes before
Special Weather Statement
National Weather Service Jacksonville FL
611 PM EDT THU AUG 31 2017
GAZ164>166-312300-
Inland Camden GA-Charlton GA-Coastal Camden GA-
611 PM EDT THU AUG 31 2017
...SIGNIFICANT WEATHER ADVISORY FOR CAMDEN AND NORTHEASTERN CHARLTON
COUNTIES UNTIL 700 PM EDT...
At 611 PM EDT, Doppler radar was tracking a strong thunderstorm near
Kings Ferry, or 7 miles northwest of Kingsland, moving northeast at
20 mph.
Excessive cloud-to-ground lightning and wind gusts of 40 to 50 mph
can be expected along with possible minor damage.
Locations impacted include...
Kingsland, Woodbine, Homeland, Tarboro, Cumberland Island, Harrietts
Bluff and Colesburg.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 3083 8142 3075 8173 3078 8177 3077 8177
3079 8179 3078 8180 3079 8181 3079 8184
3083 8190 3082 8191 3089 8208 3110 8189
3110 8184 3113 8182 3088 8141
TIME...MOT...LOC 2211Z 246DEG 18KT 3085 8177
NELSONSpecial weather statement, Aug 31, 6:21 PM EDT, 22 minutes before
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</html>The office that day
Everything else NWS Jacksonville, FL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 30, 8:13 PM EDT | Special Weather Statement | JAX | Putnam | 32 min |
| Aug 31, 3:09 PM EDT | Special Weather Statement | JAX | Marion | 51 min |
| Aug 31, 3:17 PM EDT | Special Weather Statement | JAX | Alachua | 43 min |
| Aug 31, 4:04 PM EDT | Special Weather Statement | JAX | Alachua | 41 min |
| Aug 31, 4:18 PM EDT | Areal Flood Advisory | JAX | Alachua, Marion | 57 min |
| Aug 31, 4:52 PM EDT | Special Weather Statement | JAX | Marion | 23 min |
| Aug 31, 5:30 PM EDT | Special Weather Statement | JAX | Clay | 45 min |
| Aug 31, 5:44 PM EDT | Special Weather Statement | JAX | Duval, Nassau | 31 min |
| Aug 31, 6:04 PM EDT | Special Weather Statement | JAX | Duval | 26 min |
| Aug 31, 6:14 PM EDT | Areal Flood Advisory | JAX | Clay, Duval, Saint Johns | 91 min |
| Aug 31, 6:21 PM EDT | Special Weather Statement | JAX | Saint Johns | 39 min |
| Aug 31, 7:16 PM EDT | Special Weather Statement | JAX | Saint Johns | 29 min |
| Aug 31, 7:18 PM EDT | Special Marine Warning | JAX | 87 min | |
| Aug 31, 3:20 PM EDT | Special Weather Statement | JAX | Coffee | 40 min |
| Aug 31, 3:57 PM EDT | Special Weather Statement | JAX | Coffee, Jeff Davis | 48 min |
| Aug 31, 4:24 PM EDT | Special Weather Statement | JAX | Appling | 51 min |
| Aug 31, 4:35 PM EDT | Special Weather Statement | JAX | Appling, Bacon | 40 min |
| Aug 31, 4:48 PM EDT | Special Weather Statement | JAX | Pierce | 42 min |
| Aug 31, 4:52 PM EDT | Severe Thunderstorm Warning | JAX | Bacon | 17 min |
| Aug 31, 4:58 PM EDT | Special Weather Statement | JAX | Appling | 32 min |
| Aug 31, 5:23 PM EDT | Special Weather Statement | JAX | Wayne | 52 min |
| Aug 31, 5:41 PM EDT | Special Weather Statement | JAX | Pierce | 34 min |
| Aug 31, 6:06 PM EDT | Special Weather Statement | JAX | Wayne | 24 min |
| Aug 31, 6:11 PM EDT | Special Weather Statement | JAX | Camden | 49 min |
| Aug 31, 6:32 PM EDT | Special Weather Statement | JAX | Glynn | 28 min |
| Aug 31, 6:35 PM EDT | Special Weather Statement | JAX | Brantley | 25 min |
| Aug 31, 6:50 PM EDT | Severe Thunderstorm Warning | JAX | Glynn, Wayne | 25 min |
Nearby
Severe Thunderstorm Warnings in Florida, 2017Every severe thunderstorm warning in 2017
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.