textproduct: Shreveport

KEY MESSAGES

Issued at 113 AM CDT Thu Aug 20 2026

- The oppressive heat will continue today, with the approach of a weak surface boundary into far Southeast Oklahoma and Southwest Arkansas contributing to compressional warming and the need to an upgrade to an Extreme Heat Warning for portions of extreme Northeast Texas, McCurtain County Oklahoma, and much of Southwest Arkansas through this evening.

- This weak surface boundary will also focus the potential for isolated to scattered showers and thunderstorms late this afternoon through the evening, which may yield isolated damaging downbursts.

- The oppressive heat will continue through the remainder of the forecast period, although the extent of triple digit temperatures may be scaled back by Monday as a more northwesterly flow aloft may yield daily isolated showers and thunderstorms to portions of the region.

DISCUSSION

Issued at 113 AM CDT Thu Aug 20 2026

The early morning sfc analysis indicates a a weak sfc trough extending from Cntrl/Ern OK just S of OKC to near MLC, into NW and Nrn AR from near FSM to CCA to N of JBR as of 05Z. This bndry has resulted in a narrow band of elevated convection that continues to push SE across Wrn and Cntrl AR, which should remain N of our Nrn most AR counties before gradually diminishing overnight. However, this bndry remains progged to drift S into our Nrn most counties by mid and late afternoon, resulting in compressional warming which may be similar to what was observed Wednesday afternoon over Ern OK/NW AR, where ambient air temps climbed to 108-111 degrees. Did increase the max temp forecast slightly for areas along and N of the I-30 corridor, which when combined with the humidity, will result in heat indices up to 113 degrees. Thus, the existing Heat Advisory has been upgraded to an Extreme Heat Warning for much of extreme NE TX/McCurtain County OK, and all of SW AR except Union County, and have maintained the Heat Advisory elsewhere with widespread triple digit temps again expected and heat indices of up to 110 degrees expected despite the mixing of dewpoints. Another concern is the development of isolated to scattered convection along this sfc bndry late this afternoon and especially this evening, that the various CAMs suggest will occur once heating/instability is maximized and a weakness aloft slides SE across Srn/Ern AR around the periphery of the upper ridge. This convection will likely be a bit elevated, yielding the potential for isolated damaging downbursts with some of the CAMS actually backdooring SW into portions of N LA this evening. Have expanded chance pops a bit farther SSW from the earlier forecast this evening, which may linger even into a portion of the overnight hours given the extent of lingering heat/instability. Given the elevated nature of the convection, QPF amounts should not be excessive, but will take anything at this point to cool the existing air mass and wet the parched grounds in place areawide.

There is some suggestion amongst the short term progs that the aforementioned sfc trough may drift a bit farther S and linger Friday across portions of NE TX/Srn AR/extreme Nrn LA, which may again focus an area of compressional warming and thus necessitating a need for an Extreme Heat Warning extension for this area. Regardless, some sort of heat product will again be needed areawide Friday, but will allow the day shift to make that call once newer model data is analyzed. A weakness aloft may again linger along the edge of the upper ridging in place, which along with the sfc trough, could yield isolated to widely scattered afternoon and evening convection over much of the region.

While the center of the upper ridging will begin to amplify N from the Four Corners Region this afternoon through Friday, enough of a NW flow aloft will persist through at least Saturday for the potential for isolated afternoon and evening convection over the region, but will be too little, too late to provide any relief to the widespread triple digit temps. Unfortunately, the center of the ridging will begin to drift E into the Srn Plains Sunday which will maintain the triple digit heat, while also diverting any weaknesses farther ENE of the area. However, this may be temporary as the convection development may help to weaken the ridge slightly early in the new work week to allow for isolated to scattered convection development over at least portions of Srn AR/NCntrl and NE LA. This may also result in a slight "cooling" of the afternoon temps as they try to ease back into the mid and upper 90s, although triple digit temps still look to linger a bit longer across E TX. However, confidence remains low in regards to the extent of convection coverage and the extent of these slightly cooler temps, given the various model shifts in solutions the last couple of days.

15

AVIATION

(12Z TAFS) Issued at 512 AM CDT Thu Aug 20 2026

For the 12z TAF package, VFR conditions currently prevailing across our airspace. Seeing some weak low cu skirting our far southern airspace but this should not be significant enough to impact any of our terminals with brief MVFR ceilings this morning. Instead, we should see high cu or low afternoon AC develop with the aid of daytime heating today as we await the possibility of convection developing across our far northern airspace or just north of our airspace late this afternoon/evening. Latest high res guidance continues to insist that we will at least see isolated to scattered convection move from north to south across our airspace this evening into the overnight hours, possibly impacting the TXK/ELD/SHV and MLU terminals. Any terminal impacts across NE TX are less certain so for this package, did introduce VCTS east of our NE TX terminals late this evening and prevailed that possibility through the overnight hours.

13

SPOTTER INFORMATION STATEMENT

Issued at 113 AM CDT Thu Aug 20 2026

Spotter activation may be needed late this afternoon and evening in Southeast Oklahoma and Southwest Arkansas, and for portions of extreme Northeast texas and Northern Louisiana this evening for thunderstorms that may produce damaging downburst winds. /15/

PRELIMINARY POINT TEMPS/POPS

SHV 104 78 103 78 / 0 30 20 20 MLU 102 77 102 75 / 10 30 20 20 DEQ 106 71 103 71 / 20 20 20 20 TXK 104 77 103 75 / 20 30 20 20 ELD 104 75 102 73 / 20 40 10 20 TYR 104 80 104 79 / 0 20 30 20 GGG 105 79 105 77 / 0 20 30 20 LFK 101 77 102 76 / 0 10 20 20

SHV WATCHES/WARNINGS/ADVISORIES

AR...Extreme Heat Warning from 10 AM this morning to 8 PM CDT this evening for ARZ050-051-059>061-070>072.

Heat Advisory until 8 PM CDT this evening for ARZ073.

LA...Heat Advisory until 8 PM CDT this evening for LAZ001>006-010>014- 017>022.

OK...Extreme Heat Warning from 10 AM this morning to 8 PM CDT this evening for OKZ077.

TX...Extreme Heat Warning from 10 AM this morning to 8 PM CDT this evening for TXZ096-097-108>112.

Heat Advisory until 8 PM CDT this evening for TXZ124>126-136>138- 149>153-165>167.