Heavy Rain Threat starts Friday

This weekend’s weather just felt wonderful with lows in the mid-upper 60s and highs 86-88 and less humidity. That lower level of humidity will continue through Tuesday with sunny skies even as the highs hit 90. Then, we’re in for summer’s last hurrah — a week of humid, showery weather beginning on Wednesday with a heavy rain threat for Friday and Saturday.

This ECMWF model forecast for Friday noon shows the reason why. The 150-mile wide green “line” extending from the Yucatan up towards us marks a line of intense showers and storms caused by deep tropical moisture and low level convergence. It’s the type of map that shouts local rains of an inch or two an hour. All of the models show this feature so I’m reasonably confident that it will appear, but not all models point the line at us. Some point the plume towards our east, say from the Biloxi area east towards Pensacola. Though everyone should get rain and a lot of cloud cover from this, there’s much uncertainty concerning who will get badly drenched. Notice that the rain out in the Dallas area is associated with the cold front that is well to our west. There’s not a lot push behind it, so the cooler are won’t charge through here early next week.

.

The Foreca graphic shows the increase in overnight lows and humidity starting on Wednesday. Until then, the sunny somewhat pleasant weather continues. Thursday afternoon will see showers arrive, especially on the Mississippi Gulf Coast with chances ranging from about 60% there to about 20% in inland NW locations such as Folsom and Franklinton. Friday and Saturday morning look wet just about everywhere. How much rain depends on where that tropical river of moisture gets pointed — we’ll keep you updated on Tuesday and Thursday. The only good news is that the clouds and showers will keep the highs down into the 80s.

The real tricky part of the forecast starts on Sunday and goes through next Tuesday. You could talk me into almost anything except cooler weather and the Saints winning the Super Bowl. My take is that there will be more clouds than sun along with a humid feel and a chance of showers. I think rainfall amounts during this period will be light in comparison to Friday and Saturday..But exactly when it rain….???

Even though I am uncertain about the weather Sunday through Tuesday, the models are showing some encouraging signals of a significant weather change sometime from Wednesday Oct. 7 to Friday Oct. 10. This is the ECMWF upper air and surface forecast for that Thursday morning showing a huge long-wave trough (colored contours showing a big Midwestern “U”) and a cold front (dashed blue line) extending south from Chicago to Louisiana. Winds will turn northerly (blue arrows) behind the front. This cold front will barrel on through to give us some amazing weather for the weekend of Oct. 11 and 12 — highs near 80, lows in 50s. The American GFS agrees and brings it in a day earlier. Fingers crossed, but models are pretty good with this large scale, mid-latitude stuff.

If this happens, I will blow the shofar signaling the effective end of hurricane season for our area. Some of you may want to toot your own horn since the 90 degree days will be gone. Of course, with fall pollen, some might just end up blowing their nose.

Foreca graphic for Pensacola Beach shows a greater chance of rain on Thursday, higher rainfall amounts on Friday, and Saturday than Louisiana, plus some strong east and southeast winds kicking up surf. Suffice it to say this is not beach weather beginning Wednesday afternoon.