Thunderstorms developed as a cold front moved into a warm, moist airmass. A few of these storms produced severe hail and a short lived tornado.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS EWX wrote it up.
Thunderstorms developed as a cold front moved into a warm, moist airmass. A few of these storms produced severe hail and a short lived tornado.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Austin/San Antonio, TX wrote its last area forecast discussion before the first event at Apr 6, 6:09 PM CST, 42 minutes earlier.
Area Forecast Discussion...UPDATED National Weather Service Austin/San Antonio TX 709 PM CDT Fri Apr 6 2018 .UPDATE... Please see the 00Z aviation forecast discussion below. && .AVIATION... The main concern in the short term will be the chance for showers and thunderstorms for roughly the first six hours of the forecast period. Ongoing radar trends and hi-res model data suggest scattered thunderstorms will be possible at AUS between 04-05Z and we have added a TEMPO group for a -TSRA and variable winds. Farther south at SAT and SSF, we expect a decreasing chance for convection and will only mention VCSH at this time. No precipitation is expected out west at DRT during the forecast period. Otherwise, the focus will turn to a strong cold front set to move in during the late evening and early morning hours. Some minor adjustments have been made to the timing of the front with a slightly earlier arrival now expected. Gusty north winds, especially along the I-35 corridor, will continue through tomorrow afternoon. We also expect upper end IFR cigs around the time of the frontal passage, with cigs increasing to MVFR during the morning hours. && .PREV DISCUSSION... /ISSUED 348 PM CDT Fri Apr 6 2018/ SHORT TERM (Tonight through Saturday)... Main weather headlines remain centered on two hazard types for this afternoon and into Saturday afternoon: 1) Conditional isolated strong to severe thunderstorms capable of large hail, 40-60 mph winds, and frequent lightning across far northeast Hill Country into the northern I-35 corridor and southeast towards College Station. - Timing: Early evening to 1-2am - Confidence is low to medium on occurrence. 2) Strong north winds of 20-25 mph sustained with gusts to 35-40 mph are expected behind a cold front. A wind advisory may be needed. - Timing: Early Saturday morning through Saturday afternoon - Confidence is high on occurrence. Surface analysis depicts a strong cold front just north of the Red River and a propagating dryline across north-central Texas shifting west to east. A warm-moist sector exists south of I-20 and east of I-35 characterized by ample instability of 2500-3000 J/kg, deep layer shear of 45-55kt with hindering -25 to -75 J/kg of CIN keeping a capping inversion in place. Aircraft soundings out of Austin over the past several hours also indicate a strong cap remains in place. Additionally, limited low-level convergence is ongoing with laminar surface wind fields across the Hill Country northward to Dallas Metroplex. The capping inversion is weaker farther north and convective evolution could allow for isolated to scattered storms to develop across central Texas to north-central Texas ahead of the front this afternoon. Lapse rates are very steep and thus large hail will be the primary hazard with these storms. Given the stronger cap and lack of medium to strong forcing aloft with limited evidence of a shortwave impulse, much of the region should remain storm free through 6-7pm. The one caveat is if the cap weakens more then expected an isolated supercell could develop in the far northeast Hill Country to northern I-35 corridor north of Austin towards Waco. If this does not happen, then storms are expected to develop north of the region along the front and shift south. Again, with lack of strong forcing aloft and the stronger cap in place, the strong to possibility severe storms north of the area could reach into the far northeast Hill Country of Burnet and the the I-35 corridor of Williamson to Lee. Farther south, the cap appears too strong and storms should weaken as the front moves south late tonight. The surface pressure gradient will tighten overnight and through the day Saturday behind the front as a strong high pressure system moves into the southern Plains. Wind gusts to 35-40 mph with sustained winds of 15-25 mph will be probable Saturday morning through the afternoon. A wind advisory may be needed for this time period. Much cooler temperatures are expected Saturday with highs only reaching into the 50s and remaining well below normal. Clouds and strong north winds will certainly hinder warming. Have dropped highs below guidance values. LONG TERM (Sunday through Friday)... Near-normal temperatures return by Sunday into early next week and slightly-above normal through the rest of week. A slight chance of rain will be possible early Tuesday with a reinforcing cool front and system aloft moving over the area. An active period of unsettled weather could occur late in the week as moisture and southwest flow are re-established. It will be much warmer Sunday then Saturday with south winds throttling up as a strong low pressure system develops across the southern Plains. Too little moisture/PWATs will exist for showers to be possible Sunday. An amplified shortwave trough axis will shift east across the southern plains late Saturday into Sunday. The elevated H5 NW flow and attendant cool front will shift through northern areas by Monday night and the rest of area Tuesday. Due to greater lift aloft, some light showers could form as instability remains low. Mid-week will be dry and warm despite the boundary exiting south of the area with the strong April sun. Southwest flow appears to be re-established over south-central Texas by late Thursday into Friday as a vigorous shortwave trough develops over the eastern Front Range. Confidence is low on exact timing and placement with model differences. PWATs increase as atmosphere will not be xeric in response to southerly wind fetch. Stay tuned for details. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 47 56 43 73 59 / 40 10 0 0 10 Austin Bergstrom Intl Airport 48 56 41 74 58 / 40 10 0 0 10 New Braunfels Muni Airport 52 60 43 75 59 / 30 10 0 0 - Burnet Muni Airport 43 52 40 74 57 / 40 10 0 0 10 Del Rio Intl Airport 55 71 48 82 61 / - - 0 0 0 Georgetown Muni Airport 45 51 41 73 57 / 40 10 0 0 10 Hondo Muni Airport 55 67 44 79 60 / 20 10 0 0 0 San Marcos Muni Airport 50 59 42 75 58 / 40 10 0 0 - La Grange - Fayette Regional 52 56 44 73 60 / 50 10 0 0 10 San Antonio Intl Airport 54 61 44 76 61 / 30 10 0 0 - Stinson Muni Airport 56 62 47 78 61 / 30 10 0 0 - && .EWX WATCHES/WARNINGS/ADVISORIES... None. && Mesoscale/Aviation...24 Synoptic/Grids...17 Public Service/Data Collection...Williams
Hazardous Weather Outlook National Weather Service Austin/San Antonio TX 304 PM CDT Fri Apr 6 2018 TXZ171>173-183>194-202>209-217>225-228-072015- Llano-Burnet-Williamson-Val Verde-Edwards-Real-Kerr-Bandera- Gillespie-Kendall-Blanco-Hays-Travis-Bastrop-Lee-Kinney-Uvalde- Medina-Bexar-Comal-Guadalupe-Caldwell-Fayette-Maverick-Zavala- Frio-Atascosa-Wilson-Karnes-Gonzales-De Witt-Lavaca-Dimmit- 304 PM CDT Fri Apr 6 2018 This Hazardous Weather Outlook is for South-Central Texas.. .DAY ONE...This Afternoon And Tonight. Strong storms which may briefly reach severe criteria are possible tonight for areas along and northeast of a Llano to San Marcos to Gonzales line. The main severe weather concerns will be hail and gusty winds. The greatest risk of severe storms will be farther northeast in east and northeast Texas. Storms look to weaken as they approach the area from the north late Friday night with some remaining on the strong side while decreasing in strength as they move south. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated.
Special Weather Statement
National Weather Service Austin/San Antonio TX
729 PM CDT FRI APR 6 2018
TXZ172-173-070115-
Williamson TX-Burnet TX-
729 PM CDT FRI APR 6 2018
...SIGNIFICANT WEATHER ADVISORY FOR NORTH CENTRAL WILLIAMSON AND
NORTHEASTERN BURNET COUNTIES UNTIL 815 PM CDT...
At 728 PM CDT, Doppler radar was tracking a strong thunderstorm near
Kempner, or 9 miles east of Lampasas, moving southeast at 35 mph.
Nickel size hail and wind gusts up to 50 mph will be possible with
this storm.
Locations impacted include...
Florence and Briggs.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 3091 9783 3087 9762 3072 9765 3099 9812
3103 9809 3103 9791
TIME...MOT...LOC 0028Z 292DEG 31KT 3103 9803
PLATTThe Ft Hood radar (KGRK), 67 km away, was scanning. The volume nearest the first event began at 00:49 UTC.
2 hail, 2 lightning, 1 tornado. Local standard time, as filed.
A trained spotter reported a tornado northwest of Briggs north of US 183 in northeastern Burnet County. The tornado was short lived and there wasn't any damage reported.
A thunderstorm produced golf ball size hail in northeastern Burnet County.
A thunderstorm produced quarter size hail near the intersection of Hwy 79 and Hwy 130 west of Hutto.
Lightning struck a house on La Siesta Bend in southwestern Austin. There wasn't a fire, but the house suffered significant electrical damage.
Lightning struck a house on Manchaca Rd. in southern Austin. Fire caused significant damage to the attic.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Texas in 2018Every state in 2018This day in weather historyThe tornado archive for Texas, 2018Warnings in Texas, April 2018
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 751577, 749483, 749484, 749497, 749501.