Storms Return as Heat Subsides

After today’s barn-burner things are changing. This afternoon, a thunderstorm complex in the Madisonville & Ponchatoula area gave them a good rain before petering out on it way towards Jefferson and the River Parishes. Expect more of these clusters or a line of storms moving from NW to SE in the mid-day to early afternoon hours tomorrow, but coverage will extend further east and be more widespread. The reason for the storms: A leftover cold front just to our north, shown by the dashed blue line, and a more favorable upper air environment with the heat dome moving off to our west (dark reds stay in Texas). Storms will begin near the front and move in our direction.

The heat dome will try to build back in after tomorrows fireworks, but will get shoved back west by another pronounced upper air trough coming in towards the Appalachians. This similar map is for Thursday evening showing another front just to our northwest giving us another prime evening for widespread storms.

Plus, with generally southerly winds on Tuesday and Wednesday, it’s not as if these days will be totally shower free. Bottom line: All of us should get an inch of rain sometime this week with many of us getting 2-3”. Temperatures will be 5-7 degrees cooler on Tuesday, then Wednesday - Saturday, but it’s still August so that translates to average highs near 90.

The Foreca graphic looks reasonably good. Tomorrow will probably stop in the mid 90s for most of us before the storms move in during the early afternoon hours. More are expected on Tuesday where morning storms seem likely on the Southshore and near the Lake before others develop in the afternoon on the Northshore. Fingers crossed that there will be enough storms to keep the highs closer to 90. Because storms seem more likely late Wednesday afternoon and evening than mid-day, highs could once again reach those mid 90s.

Then, there’s Thursday. All models big and small, physical and statistical point to afternoon and evening storms that could re-fire on Friday morning. A few inches of rain here could be a real blessing. After that, the front washes out and showers should be widely scattered with much lighter amounts for next weekend. Models vary all over the place for temperatures; my take is low 90s for highs.

Yes, we will probably see at least one of the two systems in the Atlantic develop in the next week. The one to the north is obviously going out to sea and I’m not expecting anything of consequence from the southern system either. I’ve taken the latest NHC outlook and extended the cone with arrows beyond 7 days. If this develops in 3-5 days, expect a track closer to the north and east arrow. If it doesn’t develop for a week, it will take the southern and western track. If it doesn’t develop at all, expect a wave to track close to Puerto Rico and die before it gets to Florida.

The European long-range continues with the same theme: No tropical storms expected in the Gulf through the third week of September.

For us….expect low 90s heat during the first week of September and last another 10 days to two weeks. An uptick in showers and storms seem likely for the following weekend - Sept. 8 and 9. I think the heat will take a more solid break for a few days sometime between Sept 16-22, followed by another brief rise into the 90s before a more permanent break of the heat during the very end of September. OK — the first part has some reasoning behind it, the last part is more of an educated guess.

Foreca graphic for Pensacola Beach shows less rainfall than here in LA/MS with most of it coming from thunderstorms late Thursday and Friday morning. Then, things settle down to more scattered showers and storms on Saturday and fewer on Sunday. High temperatures fall into the 80s - that alone might make it worth ducking in and out of showers.