Alert archive / Florida / Severe Thunderstorm Warnings in 2007
Severe Thunderstorm Warning 164, NWS Jacksonville, FL
NWS Jacksonville, FL issued this severe thunderstorm warning at Jul 21, 2007, 4:25 PM EDT for Duval County, Nassau County, Florida. It was in force for 50 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
- Jul 21, 2007, 4:25 PM EDT (20:25 UTC)
- Expired
- Jul 21, 2007, 5:15 PM EDT
- In force
- 50 min
- Issued by
- NWS Jacksonville, FL
- Area
- Counties, with a storm outline in the text
Counties Duval County, FL, Nassau County, FL
The radar
The Jacksonville radar (KJAX), 1 km from the middle of the area, began a volume at 20:27 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, 8.4 hours before the alert went out and 3 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
- 571 J/kg
- Mixed-layer CIN
- -176 J/kg
- Mixed-layer LCL
- 1070 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 32 m²/s²
- 0-3 km storm-relative helicity
- 81 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.7
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 Jul 21, 2:48 PM EDT, 1 hour 37 minutes earlier.
Area forecast discussion, Jul 21, 2:48 PM EDT, 1 hour 37 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 248 PM EDT SAT JUL 21 2007 ...SEVERE TSTM WATCH FOR THE SOUTHERN PORTION OF THE AREA THROUGH 9 PM EDT... .DISCUSSION...SO FAR SO GOOD...WE HAVE A BIT OF CONVECTION FIRING UP ON AN OLD BOUNDARY IN CHARLTON COUNTY GEORGIA BUT OTHERWISE WE REMAIN CONVECTION FREE. THAT IS LIKELY TO CHANGE SOON AS MARION COUNTY HAS CLEARED OUT MUCH EARLIER THAN ELSEWHERE AND WE HAVE GOOD CAPE IN THE LOW LEVELS AND COLD AIR ALOFT. THIS SHOULD PRODUCE A GOOD LAPSE RATE OVER THE COUNTY WITH THE MOST PRONOUNCED BOUNDARY BEING THE PRETTY SHARP BOUNDARY BETWEEN THE CLOUD COVERAGE AND THE CLEAR SKIES OVER THE NORTHERN PORTION OF THE COUNTY. BET THERE WILL BE ENOUGH TEMP CONTRASTS FOR CONVECTION TO FIRE THERE FIRST THIS AFTERNOON. HOPEFULLY ALL OF THE SEVERE STUFF STAYS SOUTH OF THE FORECAST AREA BUT IF I HAD TO BET ID PLACE MY MONEY ON SOMETHING HAPPENING IN MARION COUNTY. LOOKING AT THE SYNOPTIC SITUATION I HAVE TO ASK...IS THIS JULY? AS ALMOST LOOKS MORE LIKE A WINTER TIME TYPE PATTERN THAN MID SUMMER WITH A CLOSED UPPER LEVEL LOW OVER THE APPALACHIANS AND AN OLD FRONTAL BOUNDARY DRAPED ACROSS NORTH FLORIDA. THE FRONT WILL REMAIN ACROSS THE AREA FOR THE NEXT SEVERAL DAYS WITH COLD AIR ALOFT. SO EXPECT THE BEST CHANCE OF RAIN AND CONVECTION TO BE ACROSS THE FLORIDA PORTION THROUGH MONDAY WHERE THE GREATEST LIFT AND MOISTURE WILL BE CONCENTRATED. AS A RIDGE OVER THE MID- ATLANTIC STATES SHIFTS EAST THE RETURN FLOW WILL BRING INCREASING MOISTURE OUT OF THE GULF AND A RETURN TO NORMAL DIURNAL CONVECTION ACROSS THE ENTIRE AREA FOR NEXT WEEK. IN THE EXTENDED THE UPPER LEVEL LOW SLOWLY RETROGRADES AND DECAYS OVER THE MID WEST WITH THE MID-ATLANTIC RIDGE RE-ESTABLISHING ITS SELF ACROSS THE REGION INTO NEXT WEEKEND. && .AVIATION...VFR CONDS CONTINUE EXCEPT IN AREAS NEAR STORMS. AS WINDS SHIFT NE-E... OCCASIONAL MVFR CONDS WILL BE POSSIBLE EARLY SUNDAY MORNING FOR TAF SITES NEAR COAST. && .MARINE...NO HEADLINES. AS TROUGH SETTLES SOUTH OF THE AREA WINDS WILL SHIFT TO ONSHORE SUNDAY AND MONDAY. THEN A RIDGE WILL BUILD OVER THE WRN ATLANTIC SETTING UP SLY FLOW FOR REMAINDER OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... AMG 69 90 66 91 / 30 40 10 20 SSI 74 85 71 85 / 40 50 10 20 JAX 71 87 68 87 / 50 60 20 30 SGJ 74 82 72 84 / 60 70 20 40 GNV 71 87 69 87 / 50 70 30 40 OCF 72 87 69 87 / 50 70 30 50 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && SANDRIK/TRABERT
Hazardous weather outlook, Jul 21, 11:22 AM EDT, 5 hours 3 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE JACKSONVILLE FL 1122 AM EDT SAT JUL 21 2007 FLZ020>025-030>033-035>038-040-GAZ132>136-149>154-162>166-212200- ALACHUA-APPLING-ATKINSON-BACON-BAKER-BRADFORD-BRANTLEY- CAMDEN (COASTAL)-CAMDEN (INLAND)-CHARLTON-CLAY-CLINCH-COFFEE- COLUMBIA-DUVAL-ECHOLS-FLAGLER-GILCHRIST-GLYNN (COASTAL)- GLYNN (INLAND)-HAMILTON-JEFF DAVIS-MARION-NASSAU-PIERCE-PUTNAM- ST JOHNS-SUWANNEE-UNION-WARE-WAYNE- 1122 AM EDT SAT JUL 21 2007 THIS OUTLOOK IS FOR NORTHEAST FLORIDA AND SOUTHEAST GEORGIA. THIS AFTERNOON AND TONIGHT... ...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR THE SOUTHERN COUNTIES UNTIL 9 PM EDT... A COLD FRONT WILL SAG TO NEAR THE FLORIDA-GEORGIA LINE TODAY. THIS FEATURE IN COMBINATION WITH AN UPPER LEVEL DISTURBANCE WILL LEAD TO SCATTERED TO NUMEROUS THUNDERSTORMS ACROSS NORTHEAST FLORIDA AND EXTREME SOUTHEAST GEORGIA. ISOLATED SEVERE STORMS WILL BE POSSIBLE THIS AFTERNOON AND EVENING...IN AND NEAR THE WATCH AREA. LARGE HAIL UP TO ONE AND ONE HALF INCH IN DIAMETER AND DAMAGING WINDS WILL BE THE PRIMARY CONCERNS WITH THESE STORMS. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY... SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ARE EXPECTED EACH DAY WITH STRONG TO SEVERE THUNDERSTORMS POSSIBLE SUNDAY AFTERNOON AND EVENING. .SPOTTER INFORMATION STATEMENT... SPOTTERS ACTIVATION IS REQUESTED ACROSS NORTH FLORIDA FOR THIS AFTERNOON AND THIS EVENING. FOR ADDITIONAL INFORMATION...VISIT THE NATIONAL WEATHER SERVICE IN JACKSONVILLE WEBSITE ON THE INTERNET AT WEATHER.GOV/JAX. SANDRIK
In the hours before
Special weather statement, Jul 21, 3:27 PM EDT, 58 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE JACKSONVILLE FL 327 PM EDT SAT JUL 21 2007 FLZ024-GAZ164-212015- CHARLTON-NASSAU- 327 PM EDT SAT JUL 21 2007 ...A SIGNIFICANT WEATHER ALERT HAS BEEN ISSUED FOR CENTRAL CHARLTON AND NORTHWEST NASSAU COUNTIES FOR STRONG WINDS...SMALL HAIL AND EXCESSIVE LIGHTNING VALID UNTIL 415 PM EDT... AT 327 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM CENTERED 8 MILES WEST OF HILLIARD...MOVING SOUTHEAST AT 5 MPH. THIS STRONG THUNDERSTORM WILL ALSO AFFECT AREAS AROUND HILLIARD THROUGH 415 PM EDT. HAIL UP TO ONE HALF INCH IN DIAMETER...EXCESSIVE CLOUD-TO-GROUND LIGHTNING AND GUSTY WINDS OF 45 TO 55 MPH CAN BE EXPECTED ALONG WITH POSSIBLE MINOR DAMAGE. HEAVY RAINFALL WILL PRODUCE PONDING OF WATER ON ROADWAYS AND MINOR FLOODING OF LOW-LYING AREAS. REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY EMERGENCY MANAGEMENT. ZAPPE
Special weather statement, Jul 21, 3:42 PM EDT, 43 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE JACKSONVILLE FL 342 PM EDT SAT JUL 21 2007 FLZ040-212045- MARION- 342 PM EDT SAT JUL 21 2007 ...A SIGNIFICANT WEATHER ALERT HAS BEEN ISSUED FOR EXTREME SOUTHWESTERN MARION COUNTY FOR STRONG WINDS...SMALL HAIL AND EXCESSIVE LIGHTNING VALID UNTIL 445 PM EDT... AT 342 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM CENTERED 2 MILES EAST OF DUNNELLON...OR 7 MILES SOUTH OF RAINBOW LAKES ESTATES...MOVING EAST BETWEEN 5 AND 10 MPH. THIS STRONG THUNDERSTORM WILL ALSO AFFECT AREAS AROUND RAINBOW LAKES ESTATES AND DUNNELLON THROUGH 445 PM EDT. HAIL UP TO ONE HALF INCH IN DIAMETER...EXCESSIVE CLOUD-TO-GROUND LIGHTNING AND GUSTY WINDS OF 45 TO 55 MPH CAN BE EXPECTED ALONG WITH POSSIBLE MINOR DAMAGE. HEAVY RAINFALL WILL PRODUCE PONDING OF WATER ON ROADWAYS AND MINOR FLOODING OF LOW-LYING AREAS. REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY EMERGENCY MANAGEMENT. ZAPPE
Special weather statement, Jul 21, 3:47 PM EDT, 38 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE JACKSONVILLE FL 347 PM EDT SAT JUL 21 2007 FLZ023-212045- BAKER- 347 PM EDT SAT JUL 21 2007 ...A SIGNIFICANT WEATHER ALERT HAS BEEN ISSUED FOR NORTHERN BAKER COUNTY FOR STRONG WINDS...SMALL HAIL AND EXCESSIVE LIGHTNING VALID UNTIL 445 PM EDT... AT 347 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM CENTERED 2 MILES NORTH OF TAYLOR...OR 21 MILES SOUTHEAST OF FARGO...MOVING SLOWLY EAST 5 TO 10 MPH. THIS STRONG THUNDERSTORM WILL ALSO AFFECT AREAS AROUND TAYLOR THROUGH 445 PM EDT. HAIL UP TO ONE HALF INCH IN DIAMETER...EXCESSIVE CLOUD-TO-GROUND LIGHTNING AND GUSTY WINDS OF 45 TO 55 MPH CAN BE EXPECTED ALONG WITH POSSIBLE MINOR DAMAGE. HEAVY RAINFALL WILL PRODUCE PONDING OF WATER ON ROADWAYS AND MINOR FLOODING OF LOW-LYING AREAS. REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY EMERGENCY MANAGEMENT. ZAPPE
Special weather statement, Jul 21, 3:53 PM EDT, 32 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE JACKSONVILLE FL 353 PM EDT SAT JUL 21 2007 FLZ040-212100- MARION- 353 PM EDT SAT JUL 21 2007 ...A SIGNIFICANT WEATHER ALERT HAS BEEN ISSUED FOR EXTREME EASTERN MARION COUNTY FOR STRONG WINDS...SMALL HAIL AND EXCESSIVE LIGHTNING VALID UNTIL 500 PM EDT... AT 353 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM CENTERED 3 MILES EAST OF JUNIPER SPRINGS...MOVING SOUTHEAST AT 5 MPH. THIS STRONG THUNDERSTORM WILL ALSO AFFECT AREAS AROUND JUNIPER SPRINGS THROUGH 500 PM EDT. HAIL UP TO ONE HALF INCH IN DIAMETER...EXCESSIVE CLOUD-TO-GROUND LIGHTNING AND GUSTY WINDS OF 45 TO 55 MPH CAN BE EXPECTED ALONG WITH POSSIBLE MINOR DAMAGE. HEAVY RAINFALL WILL PRODUCE PONDING OF WATER ON ROADWAYS AND MINOR FLOODING OF LOW-LYING AREAS. REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY EMERGENCY MANAGEMENT. ZAPPE
Special weather statement, Jul 21, 4:16 PM EDT, 9 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE JACKSONVILLE FL 416 PM EDT SAT JUL 21 2007 FLZ025-212100- DUVAL- 416 PM EDT SAT JUL 21 2007 ...A SIGNIFICANT WEATHER ALERT HAS BEEN ISSUED FOR DUVAL COUNTY FOR STRONG WINDS...SMALL HAIL AND EXCESSIVE LIGHTNING VALID UNTIL 500 PM EDT... AT 416 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED STRONG THUNDERSTORMS CENTERED 12 MILES WEST OF JACKSONVILLE INTERNATIONAL AIRPORT...OR 8 MILES SOUTHWEST OF CALLAHAN...MOVING EAST AT 20 MPH. THESE STRONG THUNDERSTORMS WILL ALSO AFFECT AREAS AROUND JACKSONVILLE INTERNATIONAL AIRPORT...OCEANWAY...DOWNTOWN JACKSONVILLE... TALLYRAND...FORT CAROLINE AND ARLINGTON THROUGH 500 PM EDT. HAIL UP TO ONE HALF INCH IN DIAMETER...EXCESSIVE CLOUD-TO-GROUND LIGHTNING AND GUSTY WINDS OF 45 TO 55 MPH CAN BE EXPECTED ALONG WITH POSSIBLE MINOR DAMAGE. IF FURTHER INTENSIFICATION OCCURS A WARNING MAY BE REQUIRED. REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY EMERGENCY MANAGEMENT. HURLBUT
Special weather statement, Jul 21, 4:21 PM EDT, 4 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE JACKSONVILLE FL 421 PM EDT SAT JUL 21 2007 FLZ025-212100- DUVAL- 421 PM EDT SAT JUL 21 2007 ...A SIGNIFICANT WEATHER ALERT HAS BEEN ISSUED FOR DUVAL COUNTY FOR STRONG WINDS...SMALL HAIL AND EXCESSIVE LIGHTNING VALID UNTIL 500 PM EDT... AT 421 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM CENTERED 3 MILES SOUTH OF UNF...NEARLY STATIONARY. THIS STRONG THUNDERSTORM WILL ALSO AFFECT AREAS AROUND UNF...BAYARD...SAN PABLO AND JACKSONVILLE BEACH THROUGH 500 PM EDT. HAIL UP TO ONE HALF INCH IN DIAMETER HAS BEEN REPORTED... AND EXCESSIVE CLOUD-TO-GROUND LIGHTNING AND GUSTY WINDS OF 45 TO 55 MPH CAN BE EXPECTED ALONG WITH POSSIBLE MINOR DAMAGE. REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY EMERGENCY MANAGEMENT. HURLBUT
The office that day
Everything else NWS Jacksonville, FL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 20, 9:29 PM EDT | Special Marine Warning | JAX | 91 min | |
| Jul 21, 3:38 PM EDT | Severe Thunderstorm Warning | JAX | Nassau | 52 min |
| Jul 21, 4:08 PM EDT | Severe Thunderstorm Warning | JAX | Marion | 52 min |
| Jul 21, 5:00 PM EDT | Severe Thunderstorm Warning | JAX | Marion | 45 min |
| Jul 21, 5:14 PM EDT | Severe Thunderstorm Warning | JAX | Clay, Duval, Saint Johns | 46 min |
| Jul 21, 5:58 PM EDT | Severe Thunderstorm Warning | JAX | Clay, Putnam, Saint Johns | 47 min |
| Jul 21, 6:25 PM EDT | Special Marine Warning | JAX | 85 min | |
| Jul 21, 6:34 PM EDT | Severe Thunderstorm Warning | JAX | Columbia, Hamilton, Suwannee | 30 min |
| Jul 21, 6:41 PM EDT | Severe Thunderstorm Warning | JAX | Flagler, Putnam, Saint Johns | 64 min |
| Jul 21, 6:01 PM EDT | Severe Thunderstorm Warning | JAX | Clinch, Echols | 25 min |
| Jul 21, 6:43 PM EDT | Severe Thunderstorm Warning | JAX | Wayne | 60 min |
| Jul 21, 6:54 PM EDT | Severe Thunderstorm Warning | JAX | Appling | 51 min |
Nearby
Severe Thunderstorm Warnings in Florida, 2007Every severe thunderstorm warning in 2007
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.