A weak upper trough axis remained nearly stationary across East Texas, North Louisiana, and Southern Arkansas during the day on August 18th, with a weak surface trough stationary over these areas as well. These features focused the development of a cluster of showers and thunderstorms over portions of East Texas prior to and after daybreak, which moved very little throughout the morning.
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 SHV wrote it up.
A weak upper trough axis remained nearly stationary across East Texas, North Louisiana, and Southern Arkansas during the day on August 18th, with a weak surface trough stationary over these areas as well. These features focused the development of a cluster of showers and thunderstorms over portions of East Texas prior to and after daybreak, which moved very little throughout the morning. Given the very moist air mass in place and weak steering winds, these storms moved very little, with areas of locally heavy rainfall moving repeatedly over Central and Southern Smith County. Rainfall amounts of three to six inches fell across these areas, resulting in widespread flash flooding across the county. These storms eventually diminished during the mid and late morning hours.
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 Shreveport, LA wrote its last area forecast discussion before the first event at Aug 18, 3:22 AM CST, 1 hour 48 minutes earlier.
Area Forecast Discussion National Weather Service Shreveport LA 422 AM CDT Wed Aug 18 2021 .SHORT TERM.../Today through Thursday/ Rain is the gift that keeps on giving here in the typical dog days of summer in mid-August. This persistent upper level trough, which has effectively set up shop across the region for the better part of this week, will continue to be the driving force behind more shwrs and tstms today. Rain chances will generally be highest over our NW half today with likely to categorical PoPs capturing these areas while slightly lower chances will reside across our SE zones where forcing from the upper trough won't be quite as pronounced. Rain may be heavy at times as well, especially across our NW half due to the greater forcing and high PWATs still near 2 inches as we've seen the past several days. However, opted against issuing a Flash Flood Watch for these areas as FF guidance suggests that we should be able to add a few more inches of rainfall without issue. Additionally, the rather dry period we saw through the first half of this month allowed soils to evaporate away a lot of moisture. As far as temperatures go, expect mid and upper 80s to lower 90s as you work from NW to SE across the region with the cooler temps matching up where our highest PoPs are concentrated today. By tonight, the base of the upper trough will be lifting NE of the region with rain chances gradually decreasing from south to north through the evening and overnight hours. Low temperatures will drop back into the lower to mid 70s once again as moisture laden air will make it feel quite muggy. Moving ahead to Thursday, upper ridging along the immediate Gulf coast will gradually begin to work its way back northward as the trough will have lifted on out over the TN Valley. Even so, rain chances will remain quite high as daytime instability will combine with a very rich moisture supply to generate scattered to numerous shwrs and tstms again on Thursday. Thus, we should manage to keep high temperatures below normal for at least one more day with upper 80s to lower 90s on Thursday afternoon. /19/ .LONG TERM.../Thursday Night through Wednesday/ The forecast period begins with a model consensus indicating that broad mid-level ridging will be setting up over the northern Gulf on Thursday night and building into the ArkLaTex region Friday through the weekend. Ridging and mid-level anticyclonic flow will be centered over the area on Sunday with the centered of the ridge shifting west of the area Monday into Wednesday. This pattern will allow for diurnally driven isolated showers and thunderstorms on Friday with a mostly dry and hot forecast for the remainder of the forecast period. With fairly high confidence in the pattern with a model consensus, forecast is in line with the NBM. For temperatures, highs on Friday will be near normal seasonal values in the lower to mid 90s across the area. Temperatures will then progressively warm each day through the middle of next week with most locations reaching the upper 90s by Wednesday. Highs will near triple digits on Monday with more confidence a few locations in our area of responsibility will break 100 on Tuesday and Wednesday. Heat indices Sunday through Wednesday will warm to near 105 degrees with Heat Advisories possible. /04-Woodrum/ && .PREV DISCUSSION... /issued 103 AM CDT Wed Aug 18 2021/ AVIATION... For the 18/06 TAF period, flight conditions will become even more unfavorable through the remainder of the overnight hours into this morning with scattered convection continuing at most sites. MVFR and IFR cigs/vsbys will be possible across most terminals during this timeframe as patchy fog and low stratus develop, especially where rainfall has just occurred. Otherwise, look for convection to remain possible through the day on Wednesday as an upper trough pivots farther NE across the region with cigs gradually lifting back to VFR status by the afternoon or early evening. Vrbl winds overnight will trend more SE on Wednesday with speeds ranging from 5-10 kts. /19/ && .PRELIMINARY POINT TEMPS/POPS... SHV 90 76 91 77 / 60 30 60 10 MLU 93 75 91 75 / 50 30 60 10 DEQ 85 72 87 74 / 90 60 80 20 TXK 86 75 89 76 / 80 40 70 20 ELD 88 72 88 73 / 60 40 70 10 TYR 88 77 91 77 / 70 30 50 0 GGG 88 75 91 75 / 60 30 50 10 LFK 92 76 93 75 / 50 20 50 0 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && 19/04
Hazardous Weather Outlook National Weather Service Shreveport LA 209 AM CDT Wed Aug 18 2021 ARZ050-051-059>061-070>073-LAZ001>006-010>014-017>022-OKZ077- TXZ096-097-108>112-124>126-136>138-149>153-165>167-190715- Sevier-Howard-Little River-Hempstead-Nevada-Miller-Lafayette- Columbia-Union-Caddo-Bossier-Webster-Claiborne-Lincoln-De Soto- Red River-Bienville-Jackson-Ouachita-Sabine-Natchitoches-Winn- Grant-Caldwell-La Salle-McCurtain-Bowie-Franklin-Titus-Camp- Morris-Cass-Wood-Upshur-Marion-Smith-Gregg-Harrison-Cherokee-Rusk- Panola-Nacogdoches-Shelby-Angelina-San Augustine- 209 AM CDT Wed Aug 18 2021 This Hazardous Weather Outlook is for portions of south central Arkansas, southwest Arkansas, north central Louisiana, northwest Louisiana, southeast Oklahoma, east Texas and northeast Texas. .DAY ONE...Today and Tonight... Scattered to numerous thunderstorms are expected today before activity generally decreases tonight. Severe thunderstorms are generally not anticipated, although some storms could continue to produce frequent lightning, heavy downpours, and brief gusty winds. A few of the storms may bring localized flash flooding to locations which have seen several rounds of rainfall over the last couple of days. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday... Afternoon into early evening showers and thunderstorms are expected on Thursday. A few of the storms on Thursday will have heavy downpours which could lead to localized flash flooding. Otherwise, showers and thunderstorms will diminish with most of the area drying out this weekend into early next week. Temperatures will warm to near triple digits with heat indices nearing Heat Advisory criteria early next week. .SPOTTER INFORMATION STATEMENT... Activation of emergency management personnel...amateur radio operators...and storm spotters may be needed for today. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. 04
The Shreveport radar (KSHV), 126 km away, was scanning. The volume nearest the first event began at 11:07 UTC.
3 flash flood. Local standard time, as filed.
A water rescue was performed in the New Chapel Hill community at the intersection of County Road 289 and Highway 64 due to flash flooding.
Numerous roads were flooded in the city of Tyler.
Calloway Road was flooded, as well as the intersection of Highway 110 and Loop 323 in Tyler.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Texas in 2021Every state in 2021This day in weather historyWarnings in Texas, August 2021
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: 968035, 968037, 968038.