Alert archive / Florida / Severe Thunderstorm Warnings in 2017
Severe Thunderstorm Warning 283, NWS Jacksonville, FL
NWS Jacksonville, FL issued this severe thunderstorm warning at Sep 1, 2017, 3:17 PM EDT for Saint Johns County, Florida. It was in force for 28 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
- Sep 1, 2017, 3:17 PM EDT (19:17 UTC)
- Expired
- Sep 1, 2017, 3:45 PM EDT
- In force
- 28 min
- Issued by
- NWS Jacksonville, FL
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
County Saint Johns County, FL
The radar
The Jacksonville radar (KJAX), 70 km from the middle of the area, began a volume at 19:19 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, 7.3 hours before the alert went out and 71 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
- 1012 J/kg
- Mixed-layer CIN
- -92 J/kg
- Mixed-layer LCL
- 971 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 57 m²/s²
- 0-3 km storm-relative helicity
- 85 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.9
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 Sep 1, 8:55 AM EDT, 6 hours 22 minutes earlier.
Area forecast discussion, Sep 1, 8:55 AM EDT, 6 hours 22 minutes before
Area Forecast Discussion National Weather Service Jacksonville FL 855 AM EDT Fri Sep 1 2017 ...ISOLATED STRONG TO SEVERE STORMS POSSIBLE THIS AFTERNOON... .UPDATE... Broad and deep cyclonic flow noted across the southeast U.S. with the remnants of Harvey lifting northeast into KY today...and diffuse sfc trough extends through central GA southwest to the wern FL panhandle. Mid level high pressure over the wern Atlantic will slide eastward as well as the full latitude trough around Harvey pushing east as well. JAX 12z sounding showed sfc-6 km winds of about 20 knots and modified sfc based parcel to achieve CAPE of about 3100- 3400 J/kg, which is in agreement GFS fcst sounding. DCAPE values are enhanced as well...just over 900 J/kg. Latest forecast looks on track for numerous showers and storms today...perhaps widespread over parts of eastern northeast FL. This is a little above the consensus. Current radar shows isolated to scattered showers and storms forming over the central Fl panhandle near Tallahassee, and additional activity southwest of Cross City. Initial convection activity moving into our area later this morning will be forced by outflows from morning convection and the west coast sea breeze. This convection will push east to northeast and run up against the weaker Atlantic sea breeze, fcst to be located near I-95, which should provide a chance for a couple of strong to severe storms. Storm movement at near 20 mph along with the enhanced DCAPE should result in a chance of gusty winds in some of the stronger storms. Don't see any compelling reason to change POPS too much, just mainly to adjust timing a bit based on trends in radar and latest HRRR model. Highs today expected to reach lower 90s eastern zones where convection will be later to start (mid to late aftn hours...with temps near 90 or upper 80s across the west zones. && .AVIATION... VFR conditions at this time. Numerous showers and storms later today fcst with a TSRA TEMPO group around the 18z-22z time frame. Due to the some potentially strong storm intensity and rich moisture, brief IFR conditions and gusty winds should be expected in thunderstorms. A few storms could be strong to severe. && .MARINE... South-Southwest flow will continue at 10-15 knots with seas 2-5 ft. winds may become south-southeast by mid to late aftn and early evening. Main impacts will be offshore moving storms with gusty winds possible after 2 pm. Just minor tweaks in the fcst for the CWF update and noting that wave periods are a bit longer than anticipated around 12 seconds so will make a couple of adjustments. Rip Currents: Noting longer wave periods per buoy readings this morning and potentially higher breakers in the surf zone today so may tweak risk to moderate all beaches. && .PRELIMINARY POINT TEMPS/POPS... AMG 89 73 89 71 / 60 20 50 20 SSI 89 76 86 75 / 70 40 60 40 JAX 93 75 87 73 / 70 30 60 30 SGJ 91 75 86 74 / 80 30 60 30 GNV 90 73 86 72 / 70 60 60 20 OCF 91 74 88 73 / 80 50 60 30 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && Shashy/Corless
Hazardous weather outlook, Sep 1, 10:00 AM EDT, 5 hours 17 minutes before
Hazardous Weather Outlook National Weather Service Jacksonville FL 1000 AM EDT Fri Sep 1 2017 AMZ450-452-454-470-472-474-FLZ020>025-030>033-035>038-040-124-125- GAZ132>136-149>154-162>166-020845- 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- 1000 AM EDT Fri Sep 1 2017 ...ISOLATED STRONG TO SEVERE STORMS POSSIBLE THIS AFTERNOON... This Hazardous Weather Outlook is for Northeast Florida, Southeast Georgia and the Adjacent Coastal Waters. .DAY ONE...Today and Tonight... Scattered storms will move east northeast into the area by early this afternoon and become numerous to widespread along the I-95 corridor in the mid to late afternoon hours. Isolated strong to severe storms are possible. The strongest storms will be capable of localized damaging wind gusts and heavy rainfall. Moderate risk of rip currents at area beaches today. A few late night storms may move northeast towards the I-75 corridor late tonight. .DAYS TWO THROUGH SEVEN...Saturday through Thursday... Scattered to numerous mainly afternoon thunderstorms each day will be capable of producing gusty winds and locally heavy rainfall. .SPOTTER INFORMATION STATEMENT... Spotters are asked to self activate if warnings are issued this afternoon. For additional information, visit the National Weather Service in Jacksonville website on the internet at weather.gov/jax. Shuler
In the hours before
Special weather statement, Sep 1, 2:40 PM EDT, 37 minutes before
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</html>Local storm report, Sep 1, 2:43 PM EDT, 34 minutes before
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</html>Local storm report, Sep 1, 2:53 PM EDT, 24 minutes before
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</html>Local storm report, Sep 1, 2:56 PM EDT, 21 minutes before
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</html>Special weather statement, Sep 1, 3:12 PM EDT, 5 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 31, 8:13 PM EDT | Special Weather Statement | JAX | Flagler | 47 min |
| Aug 31, 9:45 PM EDT | Special Marine Warning | JAX | 90 min | |
| Aug 31, 10:43 PM EDT | Areal Flood Advisory | JAX | Flagler, Putnam | 92 min |
| Sep 1, 10:25 AM EDT | Special Weather Statement | JAX | Gilchrist | 35 min |
| Sep 1, 10:36 AM EDT | Special Weather Statement | JAX | Gilchrist | 39 min |
| Sep 1, 11:15 AM EDT | Special Weather Statement | JAX | Gilchrist | 45 min |
| Sep 1, 11:35 AM EDT | Special Weather Statement | JAX | Union | 40 min |
| Sep 1, 12:12 PM EDT | Special Weather Statement | JAX | Bradford, Union | 48 min |
| Sep 1, 12:25 PM EDT | Severe Thunderstorm Warning | JAX | Alachua, Bradford, Union | 35 min |
| Sep 1, 12:35 PM EDT | Special Weather Statement | JAX | Bradford, Clay | 40 min |
| Sep 1, 12:42 PM EDT | Special Weather Statement | JAX | Alachua | 48 min |
| Sep 1, 1:10 PM EDT | Special Weather Statement | JAX | Clay, Duval | 50 min |
| Sep 1, 1:13 PM EDT | Special Weather Statement | JAX | Putnam | 47 min |
| Sep 1, 1:22 PM EDT | Severe Thunderstorm Warning | JAX | Duval, Nassau | 23 min |
| Sep 1, 1:25 PM EDT | Special Marine Warning | JAX | 95 min | |
| Sep 1, 1:30 PM EDT | Special Weather Statement | JAX | Alachua | 45 min |
| Sep 1, 1:52 PM EDT | Severe Thunderstorm Warning | JAX | Duval, Nassau | 53 min |
| Sep 1, 2:18 PM EDT | Special Weather Statement | JAX | Marion | 42 min |
| Sep 1, 2:28 PM EDT | Special Weather Statement | JAX | Saint Johns | 47 min |
| Sep 1, 2:36 PM EDT | Severe Thunderstorm Warning | JAX | Marion | 37 min |
| Sep 1, 2:50 PM EDT | Areal Flood Advisory | JAX | Marion | 2 hr |
| Sep 1, 2:56 PM EDT | Special Marine Warning | JAX | 94 min | |
| Sep 1, 3:07 PM EDT | Areal Flood Advisory | JAX | Flagler, Putnam, Saint Johns | 113 min |
| Sep 1, 3:12 PM EDT | Special Weather Statement | JAX | Saint Johns | 48 min |
| Sep 1, 3:15 PM EDT | Special Weather Statement | JAX | Marion | 45 min |
| Sep 1, 3:47 PM EDT | Special Weather Statement | JAX | Putnam | 43 min |
| Sep 1, 3:58 PM EDT | Special Weather Statement | JAX | Flagler | 32 min |
| Sep 1, 4:11 PM EDT | Severe Thunderstorm Warning | JAX | Flagler, Putnam | 15 min |
| Sep 1, 4:25 PM EDT | Special Marine Warning | JAX | 65 min | |
| Sep 1, 4:29 PM EDT | Special Weather Statement | JAX | Flagler | 46 min |
| Sep 1, 4:33 PM EDT | Areal Flood Advisory | JAX | Flagler | 117 min |
| Sep 1, 4:36 PM EDT | Severe Thunderstorm Warning | JAX | Flagler | 24 min |
| Sep 1, 5:01 PM EDT | Special Weather Statement | JAX | Flagler | 29 min |
| Sep 1, 5:26 PM EDT | Special Marine Warning | JAX | 64 min | |
| Sep 1, 5:39 PM EDT | Areal Flood Advisory | JAX | Flagler | 96 min |
| Sep 1, 6:47 PM EDT | Special Weather Statement | JAX | Marion | 28 min |
| Aug 31, 8:38 PM EDT | Areal Flood Advisory | JAX | Brantley, Glynn | 97 min |
| Aug 31, 8:49 PM EDT | Special Weather Statement | JAX | Atkinson, Coffee | 41 min |
| Aug 31, 8:54 PM EDT | Special Weather Statement | JAX | Camden | 36 min |
| Aug 31, 9:33 PM EDT | Special Weather Statement | JAX | Clinch, Ware | 42 min |
| Aug 31, 9:40 PM EDT | Special Weather Statement | JAX | Glynn | 50 min |
| Sep 1, 2:20 PM EDT | Special Weather Statement | JAX | Atkinson, Coffee, Jeff Davis | 40 min |
| Sep 1, 2:40 PM EDT | Special Weather Statement | JAX | Atkinson, Bacon, Coffee, Jeff Davis | 50 min |
| Sep 1, 3:30 PM EDT | Special Weather Statement | JAX | Appling, Bacon | 30 min |
| Sep 1, 3:43 PM EDT | Severe Thunderstorm Warning | JAX | Appling | 17 min |
| Sep 1, 4:01 PM EDT | Special Weather Statement | JAX | Appling | 44 min |
| Sep 1, 5:10 PM EDT | Special Weather Statement | JAX | Ware | 50 min |
| Sep 1, 5:42 PM EDT | Special Weather Statement | JAX | Ware | 48 min |
| Sep 1, 5:58 PM EDT | Severe Thunderstorm Warning | JAX | Brantley, Charlton, Ware | 15 min |
| Sep 1, 6:16 PM EDT | Special Weather Statement | JAX | Brantley | 29 min |
| Sep 1, 7:16 PM EDT | Special Weather Statement | JAX | Charlton | 44 min |
| Sep 1, 7:51 PM EDT | Special Weather Statement | JAX | Pierce | 39 min |
| Sep 1, 7:54 PM EDT | Special Weather Statement | JAX | Ware | 51 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.