Alert archive / Florida / Severe Thunderstorm Warnings in 2020
Severe Thunderstorm Warning 229, NWS Jacksonville, FL
NWS Jacksonville, FL issued this severe thunderstorm warning at Nov 30, 2020, 5:29 AM EST for Alachua County, Bradford County, Clay County, Florida. It was in force for 14 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
- Nov 30, 2020, 5:29 AM EST (10:29 UTC)
- Expired
- Nov 30, 2020, 5:43 AM EST
- In force
- 14 min
- Issued by
- NWS Jacksonville, FL
- Area
- Storm-based polygon
- Tornado
- Possible
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Alachua County, FL, Bradford County, FL, Clay County, FL
The radar
The Jacksonville radar (KJAX), 80 km from the middle of the area, began a volume at 10:33 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
Tallahassee Rgnl, FL (KTLH), launched 00:00Z, 10.5 hours before the alert went out and 217 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
- 7 J/kg
- Mixed-layer CIN
- -68 J/kg
- Mixed-layer LCL
- 628 m above ground
- 0-6 km bulk shear
- 70 kt
- 0-1 km storm-relative helicity
- 365 m²/s²
- 0-3 km storm-relative helicity
- 478 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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 Nov 30, 2:03 AM EST, 3 hours 26 minutes earlier.
Area forecast discussion, Nov 30, 2:03 AM EST, 3 hours 26 minutes before
Area Forecast Discussion
National Weather Service Jacksonville FL
203 AM EST Mon Nov 30 2020
.Near Term...[through Tonight]...
Strong cold front will move east southeast across the region this
morning. Expect it to be east of the area by noon. Continued
potential for strong wind gusts in storms ahead of and along the
boundary, and can not rule out potential for an isolated tornado
due to shear and frontal convergence. Clearing will follow the
front, but wrap around moisture is expected to pivot across SE GA.
The combination of the cloud cover and cold advection will cause
temperatures to fall through the afternoon across SE GA, whereas
the sunshine should help keep temperatures fairly steady through
much of the day time hours over NE FL. In general, highs Today
will be recorded this morning. It will also be fairly breezy
Today.
For Tonight, skies will clear from the northwest, with high pressure
building from the west. The gradient will remain fairly tight
through the night, so winds will continue to stir overnight. The
winds will minimize frost formation despite lows in the 30s.
Low temperatures near or at freezing possible well inland, but
not expecting to be at or below 32 long enough to warrant a freeze
warning at this point.
&&
.SHORT TERM [Tuesday through Wednesday Night]...
...WIDESPREAD INLAND LIGHT FREEZE EVENT EXPECTED TUESDAY NIGHT...
Tuesday...Sunny skies and cold conditions as Meteorological Winter
begins on 12/1 and gusty Northwest winds continue at 15-20 mph
with gusts of 25-30 mph and strong cold air advection will hold
Max Temps around 50 degrees across SE GA and lower/middle 50s for
NE FL.
Tuesday Night...As cold high pressure settles over the region
expect NW winds to decrease to less than 5 mph and along with
mostly clear skies will set up good radiational cooling
conditions and a widespread light freeze is expected over all
inland areas, with lows in the upper 20s across SE GA and near
30 degrees across inland NE FL and Freeze headlines will likely
be required. Some light frost will be possible as well by early
Wednesday morning as winds become near calm in wind sheltered
areas.
Wednesday...High pressure continues to push Northeast of the
region and surface winds become light Northeast and under
Mostly Sunny skies Max Temps will modify slightly into the
middle 50s SE GA and upper 50s/near 60 degrees across NE FL.
Upper level cloud cover increases Wed Night but another night
of widespread low temps in the 30s possible over inland areas
and 40s along the Atlc Coast and another brief light freeze
not out of the question for inland SE GA areas near the
Altamaha River Basin.
&&
.LONG TERM [Thursday Through Sunday]...
Thursday...Mainly dry conditions with increasing high clouds
ahead of next frontal system and expect milder temps with the
onshore flow off the Atlantic as Sfc High pressure builds into
the Carolinas. Max Temps into the 60s across SE GA and near 70
across NE FL.
Friday...Long-range models have backed off the intensity of
next shortwave trof energy/moisture available and now rainfall
chances are mainly in the 20-40% range with the next frontal
passage. Max Temps will likely reach into the 70-75 degree
range and lows falling into the 40s/50s Fri Night.
Sat/Sun...Models struggling to handle the expected mid level
cut-off low feature to push across the SE US over the weekend,
but for now it appears as though it will not phase with moisture
over the Gulf of Mexico and cross the NE FL/SE GA region with
mainly dry conditions and seasonably cool temps with Highs in the
60s and lows in the 40s, but confidence remains low in the model
solutions from the Friday through Sunday time frame.
&&
.FIRE WEATHER...
On Tuesday, much colder and drier airmass will combine with gusty
Northwest winds and humidity values falling into the 30 to 35
percent range to provide for more hazardous fire weather
conditions but for now expect values to stay just above critical
levels.
&&
.Marine...
A strong cold front will move east across area this morning. High
pressure will build from the west this afternoon through Tonight.
The high will build overhead Tuesday through Tuesday night. The high
will then build toward the northeast Wednesday through Thursday. A
wave of low pressure will move northeast out of the gulf, and across
area Thursday night through Friday. The region will be between low
pressure to the northeast and high pressure building from the west
over the weekend.
Rip Currents: SE GA: Moderate through Tuesday
NE FL: Moderate through Tuesday
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 61 33 49 27 56 / 10 10 0 0 0
SSI 69 37 50 34 56 / 90 10 0 0 0
JAX 68 35 53 30 58 / 90 0 0 0 0
SGJ 71 38 54 36 59 / 90 0 0 0 0
GNV 69 34 53 29 57 / 70 0 0 0 0
OCF 70 36 54 30 59 / 90 0 0 0 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...Small Craft Advisory until 11 PM EST Tuesday for 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.
Small Craft Advisory until 11 AM EST Tuesday for 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.
&&In the hours before
Special weather statement, Nov 30, 4:11 AM EST, 1 hour 18 minutes before
Special Weather Statement
National Weather Service Jacksonville FL
411 AM EST Mon Nov 30 2020
GAZ149-152-162-163-250-350-301015-
Atkinson GA-Clinch GA-Brantley GA-Echols GA-Northern Ware GA-
Southern Ware GA-
411 AM EST Mon Nov 30 2020
...SIGNIFICANT WEATHER ADVISORY FOR ECHOLS...ATKINSON...WEST CENTRAL
BRANTLEY...WARE AND CLINCH COUNTIES UNTIL 515 AM EST...
* At 411 AM EST, National Weather Service meteorologists were
tracking a strong thunderstorm near Homerville, moving northeast at
35 mph.
* Wind gusts up to 50 mph and funnel clouds possible with this storm.
* Locations impacted include...
Waycross, Homerville, Pearson, Fargo, Argyle, Du Pont, Boggy Bay,
Pebble Hill, Needmore and Manor.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This activity was also developing in an environment favorable for the
formation of funnel clouds. Stay tuned to NOAA weather radio and
local media for additional updates and possible warnings.
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 3142 8296 3140 8284 3136 8282 3137 8263
3147 8263 3147 8250 3142 8248 3140 8240
3138 8242 3136 8239 3129 8239 3126 8235
3122 8231 3122 8223 3101 8218 3101 8241
3080 8242 3078 8215 3057 8221 3062 8300
TIME...MOT...LOC 0911Z 231DEG 30KT 3110 8275
KBSpecial weather statement, Nov 30, 4:53 AM EST, 36 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 |
|---|---|---|---|---|
| Nov 29, 11:23 PM EST | Special Weather Statement | JAX | Suwannee | 52 min |
| Nov 29, 11:52 PM EST | Special Weather Statement | JAX | Hamilton | 38 min |
| Nov 30, 12:31 AM EST | Special Weather Statement | JAX | Hamilton | 44 min |
| Nov 30, 3:03 AM EST | Special Weather Statement | JAX | Columbia, Gilchrist, Hamilton, Suwannee | 57 min |
| Nov 30, 3:18 AM EST | Tornado Warning | JAX | Hamilton | 42 min |
| Nov 30, 3:58 AM EST | Special Weather Statement | JAX | Alachua, Baker, Columbia, Gilchrist, Hamilton, Suwannee and 1 more | 62 min |
| Nov 30, 4:57 AM EST | Special Weather Statement | JAX | Alachua, Baker, Bradford, Clay, Columbia, Duval and 4 more | 63 min |
| Nov 30, 5:06 AM EST | Severe Thunderstorm Warning | JAX | Alachua | 24 min |
| Nov 30, 5:56 AM EST | Special Weather Statement | JAX | Bradford, Clay, Duval, Marion, Nassau, Putnam | 34 min |
| Nov 30, 6:03 AM EST | Special Marine Warning | JAX | 117 min | |
| Nov 30, 6:25 AM EST | Special Weather Statement | JAX | Clay, Duval, Marion, Nassau, Putnam, Saint Johns | 20 min |
| Nov 30, 6:46 AM EST | Special Weather Statement | JAX | Duval, Flagler, Putnam, Saint Johns | 29 min |
| Nov 30, 7:17 AM EST | Special Weather Statement | JAX | Flagler, Putnam, Saint Johns | 28 min |
| Nov 30, 7:44 AM EST | Special Weather Statement | JAX | Flagler, Saint Johns | 31 min |
| Nov 30, 7:56 AM EST | Special Marine Warning | JAX | 94 min | |
| Nov 30, 8:23 AM EST | Special Weather Statement | JAX | Flagler | 37 min |
| Nov 30, 9:28 AM EST | Special Marine Warning | JAX | 62 min | |
| Nov 30, 3:49 PM EST | Freeze Watch | JAX | Alachua, Baker, Bradford, Gilchrist, Marion, Nassau and 2 more | 10 hr |
| Nov 30, 12:59 AM EST | Special Weather Statement | JAX | Echols | 31 min |
| Nov 30, 2:32 AM EST | Special Weather Statement | JAX | Coffee, Jeff Davis | 43 min |
| Nov 30, 3:06 AM EST | Special Weather Statement | JAX | Atkinson, Clinch, Echols | 54 min |
| Nov 30, 3:13 AM EST | Special Weather Statement | JAX | Coffee, Jeff Davis | 62 min |
| Nov 30, 3:52 AM EST | Severe Thunderstorm Warning | JAX | Atkinson, Coffee, Ware | 38 min |
| Nov 30, 3:55 AM EST | Severe Thunderstorm Warning | JAX | Atkinson, Clinch, Echols, Ware | 38 min |
| Nov 30, 4:05 AM EST | Special Weather Statement | JAX | Bacon | 55 min |
| Nov 30, 4:11 AM EST | Special Weather Statement | JAX | Atkinson, Clinch, Echols, Ware | 64 min |
| Nov 30, 4:17 AM EST | Severe Thunderstorm Warning | JAX | Charlton, Clinch, Ware | 19 min |
| Nov 30, 4:27 AM EST | Severe Thunderstorm Warning | JAX | Atkinson, Bacon, Coffee, Ware | 48 min |
| Nov 30, 4:53 AM EST | Special Weather Statement | JAX | Coffee, Jeff Davis | 52 min |
| Nov 30, 4:59 AM EST | Special Weather Statement | JAX | Appling | 46 min |
| Nov 30, 5:09 AM EST | Special Weather Statement | JAX | Brantley, Charlton | 36 min |
| Nov 30, 5:19 AM EST | Special Weather Statement | JAX | Atkinson, Clinch, Echols | 41 min |
| Nov 30, 5:31 AM EST | Special Weather Statement | JAX | Appling, Bacon, Pierce, Ware | 29 min |
| Nov 30, 5:39 AM EST | Special Weather Statement | JAX | Camden, Charlton, Glynn | 51 min |
Nearby
Severe Thunderstorm Warnings in Florida, 2020Every severe thunderstorm warning in 2020
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.