Alert archive / Florida / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 99, NWS Jacksonville, FL
NWS Jacksonville, FL issued this severe thunderstorm warning at May 4, 1998, 12:50 PM EDT for Flagler County, Saint Johns County, Florida. It was in force for 50 min. 1 report came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- May 4, 1998, 12:50 PM EDT (16:50 UTC)
- Expired
- May 4, 1998, 1:40 PM EDT
- In force
- 50 min
- Issued by
- NWS Jacksonville, FL
- Area
- Whole counties
Counties Flagler County, FL, Saint Johns County, FL
The radar
The Jacksonville radar (KJAX), 94 km from the middle of the area, began a volume at 16:54 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| May 4, 1:05 PM EDT | Thunderstorm Wind 75 | St Augustine, FL |
NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.
The nearest sounding before it
Jacksonville, FL (KJAX), launched 12:00Z, 4.8 hours before the alert went out and 96 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
- 1091 J/kg
- Mixed-layer CIN
- -119 J/kg
- Mixed-layer LCL
- 904 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 81 m²/s²
- 0-3 km storm-relative helicity
- 78 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 2.6
The text
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
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 May 4, 9:14 AM EDT, 3 hours 36 minutes earlier.
Area forecast discussion, May 4, 9:14 AM EDT, 3 hours 36 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 840 AM EDT MON MAY 4 1998 SHWRS AND TSTMS CONT IN ADV OF FRNTL SYS SLWLY PROGRESSING THRU THE AREA THIS AM... W/ THE STRONGER STORMS PUSHING OFF THE CST IN THE WRN FL PNDL. FNT LOOKS TO WASHOUT THRU THE DAY TDY PUSHING SLWLY THRU N CNTRL FL BY LATE THIS EVE. UPR LVL SHRTWV ACTVTY CONTS TO ROTATE THRU TROF BASE AS UPR LVL CLOSED LOW OPENS UP AND LIFTS OUT AS THE NXT STRNG SHRTWV WV ENERGY DROPS DOWN. UPR LVL PTN OVR THE AREA FLATTENS OUT W/ CONTD ENERGY MOVING THRU THE LWR PTN OF THE SOUTHERN STATES THRU THE FCST CYCLE. MRNG SOUNDING IS INDCG A DRY SLOT FROM 950 THRU ABT 700 MB. AFTN CAPES WHEN MODIFIED APPROACH 3500 (J/KG) W/ PRECIP WATER DROPPING TO ONE INCH. POTENTIAL LOOKS THERE BUT W/ MSTR SO LMTD... WILL HAVE SCTD TSTMS OVR GA WHILE FL LOOKS A BIT MORE FAVORABLE. WILL AMD FL ZONES TO MAKE SOME SLIGHT ADJMTS... FOR GA WOULD ONLY SUGGEST RAISING TEMPS SLIGHTLY. NOTHERWISE... FCST PACKAGES LOOKS ALRIGHT. K. KUYPER
The office that day
Everything else NWS Jacksonville, FL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 4, 12:45 PM EDT | Severe Thunderstorm Warning | JAX | Putnam | 35 min |
| May 4, 12:53 PM EDT | Severe Thunderstorm Warning | JAX | Marion | 47 min |
| May 4, 4:31 PM EDT | Severe Thunderstorm Warning | JAX | Hamilton | 64 min |
| May 4, 5:05 PM EDT | Tornado Warning | JAX | Hamilton | 50 min |
| May 3, 10:02 PM EDT | Severe Thunderstorm Warning | JAX | Jeff Davis | 28 min |
| May 3, 10:13 PM EDT | Severe Thunderstorm Warning | JAX | Appling | 32 min |
| May 4, 1:05 PM EDT | Severe Thunderstorm Warning | JAX | Appling, Bacon, Jeff Davis | 50 min |
| May 4, 1:16 PM EDT | Severe Thunderstorm Warning | JAX | Pierce, Wayne | 49 min |
| May 4, 1:16 PM EDT | Severe Thunderstorm Warning | JAX | Ware | 49 min |
| May 4, 2:19 PM EDT | Severe Thunderstorm Warning | JAX | Pierce, Wayne | 61 min |
| May 4, 3:42 PM EDT | Severe Thunderstorm Warning | JAX | Appling, Wayne | 78 min |
| May 4, 3:53 PM EDT | Severe Thunderstorm Warning | JAX | Clinch, Echols | 77 min |
| May 4, 4:23 PM EDT | Severe Thunderstorm Warning | JAX | Bacon, Pierce | 47 min |
| May 4, 5:02 PM EDT | Tornado Warning | JAX | Appling, Bacon | 48 min |
| May 4, 5:14 PM EDT | Severe Thunderstorm Warning | JAX | Pierce | 46 min |
| May 4, 5:39 PM EDT | Severe Thunderstorm Warning | JAX | Wayne | 51 min |
| May 4, 6:08 PM EDT | Severe Thunderstorm Warning | JAX | Echols | 67 min |
| May 4, 6:12 PM EDT | Severe Thunderstorm Warning | JAX | Pierce | 48 min |
| May 4, 6:36 PM EDT | Severe Thunderstorm Warning | JAX | Wayne | 64 min |
| May 4, 7:40 PM EDT | Severe Thunderstorm Warning | JAX | Clinch | 30 min |
Nearby
Severe Thunderstorm Warnings in Florida, 1998Every severe thunderstorm warning in 1998
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.