Alert archive / Texas / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 86, NWS Austin/San Antonio, TX
NWS Austin/San Antonio, TX issued this severe thunderstorm warning at May 11, 1999, 5:55 PM CDT for Llano County, Texas. It was in force for 60 min. 2 reports 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 11, 1999, 5:55 PM CDT (22:55 UTC)
- Expired
- May 11, 1999, 6:55 PM CDT
- In force
- 60 min
- Issued by
- NWS Austin/San Antonio, TX
- Area
- Whole counties
County Llano County, TX
The radar
The Ft Hood radar (KGRK), 124 km from the middle of the area, began a volume at 22:54 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 11, 5:58 PM CDT | Hail 2.5 | Castell, TX | |
| May 11, 6:35 PM CDT | Hail 1.5 | Castell, TX |
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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| May 11, 3:30 PM CDT | Tornado Watch | SPC | 7 hr |
The nearest sounding before it
Del Rio, TX (KDRT), launched 12:00Z, 10.9 hours before the alert went out and 255 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
- 2571 J/kg
- Mixed-layer CIN
- -131 J/kg
- Mixed-layer LCL
- 553 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 126 m²/s²
- 0-3 km storm-relative helicity
- 186 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 3.8
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KSAT 112254 RRA SVRSAT TXC299-112355- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX 555 PM CDT TUE MAY 11 1999 THE NATIONAL WEATHER SERVICE IN AUSTIN/SAN ANTONIO HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... LLANO COUNTY IN TEXAS * UNTIL 655 PM CDT * AT 550 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM ON THE MASON/LLANO COUNTY LINE NEAR THE COMMUNITY OF ESBON ... MOVING NORTHEAST AT 10 MPH. * THE SEVERE THUNDERSTORM WILL BE NEAR... STATE HIGHWAY 71 WEST JUST WEST OF VALLEY SPRING BY 615 PM AND NORTH OF VALLEY SPRING ON THE LLANO/SAN SABA COUNTY LINE BY 630 PM. GO INSIDE A STURDY BUILD8ING AND STAY AWAY FROM WINDOWS! A TORNADO WATCH IS IN EFFECT. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE WARNING. CFM
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.
In the hours before
Special weather statement, May 11, 2:45 PM CDT, 3 hours 10 minutes before
TXZ171>173-183>194-202>209-217>225-228-112300- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX 245 PM CDT TUE MAY 11 1999 ...THREAT OF SEVERE WEATHER LATE THIS AFTERNOON AND TONIGHT... ...FLASH FLOOD WATCH IN EFFECT TONIGHT FOR THE HILL COUNTRY AND MOST OF SOUTH CENTRAL TEXAS... TO THE NORTH AND WEST...CONVECTION HAS BEGUN OVER THE HILL COUNTRY AHEAD OF THE COLD FRONTAL BOUNDARY BETWEEN SAN ANGELO AND JUNCTION. THE PRESENCE OF THE COLD FRONT...A VERY UNSTABLE AIRMASS OVER SOUTH TEXAS AND VERY WARM DAYTIME HIGHS...WILL TRIGGER STRONG TO SEVERE THUNDERSTORMS LATE THIS AFTERNOON AND THIS EVENING OVER THE HILL COUNTRY. THE STORMS WILL BE CAPABLE OF PRODUCING LARGE HAIL AND WIND GUSTS IN EXCESS OF 60 MPH AS THEY MOVE EAST ACROSS THE HILL COUNTRY INTO SOUTH CENTRAL TEXAS. AN UPPER LEVEL DISTURBANCE WILL INTERACT WITH THE COLD FRONT THIS EVENING...INCREASING THE CHANCES OF SEVERE THUNDERSTORM DEVELOPMENT. AS THE EVENING PROGRESSES INTO THE OVERNIGHT HOURS...THE STORMS WILL EVOLVE INTO HEAVY RAIN PRODUCERS. A FLASH FLOOD WATCH REMAINS IN EFFECT TONIGHT ALONG AND EAST OF A LINE FROM MENARD TO ROCKSPRINGS TO HONDO TO KARNES CITY AND CUERO. LAW ENFORCEMENT AGENCIES...EMERGENCY MANAGEMENT OFFICIALS...STORM SPOTTER GROUPS...AND OTHER INTERESTED CONCERNS SHOULD MONITOR THIS SITUATION AND TAKE APPROPRIATE ACTION SHOULD SEVERE WEATHER THREATEN YOUR AREA. STAY TUNED TO NOAA WEATHER RADIO...COMMERCIAL TELEVISION OR RADIO STATIONS...OR YOUR CABLE TELEVISION PROVIDER FOR LATER STATEMENTS CONCERNING THIS POTENTIALLY DANGEROUS SEVERE WEATHER THREAT.
Special weather statement, May 11, 2:45 PM CDT, 3 hours 10 minutes before
TXZ171>173-183>194-202>209-217>225-228-112300- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX 245 PM CDT TUE MAY 11 1999 ...THREAT OF SEVERE WEATHER LATE THIS AFTERNOON AND TONIGHT... ...FLASH FLOOD WATCH IN EFFECT TONIGHT FOR THE HILL COUNTRY AND MOST OF SOUTH CENTRAL TEXAS... TO THE NORTH AND WEST...CONVECTION HAS BEGUN OVER THE HILL COUNTRY AHEAD OF THE COLD FRONTAL BOUNDARY BETWEEN SAN ANGELO AND JUNCTION. THE PRESENCE OF THE COLD FRONT...A VERY UNSTABLE AIRMASS OVER SOUTH TEXAS AND VERY WARM DAYTIME HIGHS...WILL TRIGGER STRONG TO SEVERE THUNDERSTORMS LATE THIS AFTERNOON AND THIS EVENING OVER THE HILL COUNTRY. THE STORMS WILL BE CAPABLE OF PRODUCING LARGE HAIL AND WIND GUSTS IN EXCESS OF 60 MPH AS THEY MOVE EAST ACROSS THE HILL COUNTRY INTO SOUTH CENTRAL TEXAS. AN UPPER LEVEL DISTURBANCE WILL INTERACT WITH THE COLD FRONT THIS EVENING...INCREASING THE CHANCES OF SEVERE THUNDERSTORM DEVELOPMENT. AS THE EVENING PROGRESSES INTO THE OVERNIGHT HOURS...THE STORMS WILL EVOLVE INTO HEAVY RAIN PRODUCERS. A FLASH FLOOD WATCH REMAINS IN EFFECT TONIGHT ALONG AND EAST OF A LINE FROM MENARD TO ROCKSPRINGS TO HONDO TO KARNES CITY AND CUERO. LAW ENFORCEMENT AGENCIES...EMERGENCY MANAGEMENT OFFICIALS...STORM SPOTTER GROUPS...AND OTHER INTERESTED CONCERNS SHOULD MONITOR THIS SITUATION AND TAKE APPROPRIATE ACTION SHOULD SEVERE WEATHER THREATEN YOUR AREA. STAY TUNED TO NOAA WEATHER RADIO...COMMERCIAL TELEVISION OR RADIO STATIONS...OR YOUR CABLE TELEVISION PROVIDER FOR LATER STATEMENTS CONCERNING THIS POTENTIALLY DANGEROUS SEVERE WEATHER THREAT.
The office that day
Everything else NWS Austin/San Antonio, TX issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 11, 5:06 PM CDT | Severe Thunderstorm Warning | EWX | Llano | 54 min |
| May 11, 6:03 PM CDT | Tornado Warning | EWX | Llano | 62 min |
| May 11, 6:18 PM CDT | Flash Flood Warning | EWX | Llano | 3 hr |
Nearby
Severe Thunderstorm Warnings in Texas, 1999Every severe thunderstorm warning in 1999
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.