Plaincast

Messages

Impactful heat conditions will persist today and Tuesday - anyone planning to be outdoors for extended periods of time is urged to take precautions including drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.

Rain chances will remain very low through Wednesday. Scattered thunderstorm chances return Thursday through Saturday as the upper ridge weakens and a frontal boundary settles toward the northern Gulf Coast.

Short Term

(Now through Thursday night) Issued at 1211 PM CDT Mon Jul 27 2026

Starting off with early this afternoon looking at the big picture, anomalously strong ridging remains anchored in place over the four-corners region of the US, with SE LA/S MS being on the eastern periphery of the ridge providing northerly mid to upper- level flow. Regardless of the general area being on the eastern side of the ridge, heights remain anomalously high over the area providing above-normal temperatures. Made no adjustments to the Heat Advisory already in place as max heat indices will likely top in the 104-108 range, closing in on 108-110 for coastal areas. Did apply a small lowering in afternoon dewpoints to account for mixing, but still revealed impactful heat indices for today and will continue to message heat precautions for those outdoors.

Tuesday, the heat cranks up a tad, enough so that we could see more patchy areas of 113-115 heat indices mainly across coastal tidal lake areas and coastal MS, enough to go ahead and upgrade the Extreme Heat Watch to a Warning. Heat Advisories elsewhere. Again, impacts will remain enhanced during this time frame. Heatrisk data, a newer metric to approximate how unusual the heat is to sensitive communities continues to flag strongly at portions of the area at a Category 4 - labeled extreme with no overnight relief affecting anyone without cooling/hydration. Moreso, we'll continue to remain close to, if not surpassing a few record warm lows which reflects the dangerous heat impacting the area.

Mid-week Wednesday and Thursday, the ridge to the west pulls west some revealing lowering heights as more notable troughing digs into the SE US. Weaker heights overall will 1) begin a slow reduction to heat (from an extreme level) and 2) introduce more prominent/distinct PVA/waves of energy to surge south from the mid/upper MS valley region. This will greatly support either diurnally-forced convection each afternoon (morning convection for nearshore waters - introducing daily morning waterspout risks) and/or clusters or complexes of thunderstorms from the north surging south. Hard to narrow down specifics at this time, as greater confidence/timing will come when within the CAM time range but as always down here, you get either the heat, or the daily storm risks. KLG

Long Term

(Friday through Sunday night) Issued at 1211 PM CDT Mon Jul 27 2026

Late-week into the upcoming weekend, seeing increasing confidence in a distinct shortwave trough riding southeast along the northwesterly flow aloft. This will greatly increase shower/storm risks each day bringing typical threats including strong, gusty downburst winds and waterspouts for marine areas. An attendant surface low may try to form downstream of the divergent flow in the lower/mid MS valley region. This may need to be watched with how strong this low could become and the location of this low, as any surface low with northwest flow could cause a few surprises in the form of more noticable active weather. Low confidence for now, something we'll continue to monitor. Depending on how far any subtle reflection of a frontal boundary (associated with the surface low) makes it into the northern Gulf, it's possible we try to dry out going into later parts of the weekend. Will keep an eye on it but the main message is for late-week and into Saturday, expect daily enhanced rain/storm chances. KLG