Monday, August 17, 2015

A stormy week ahead also means slightly cooler temps

Though it's a bit early to be looking ahead to autumn, I've had several people comment that they are DONE with the 90s and ready to start looking forward to fall weather - highs in the 70s, lows in the 50s, pumpkin spice at Starbucks... :-)  I don't think we're there yet, but we've already lost an hour of daylight since late June and average highs drop back below 90 as the calendar turns to September.

In the meantime, we have a stormy week ahead as a fairly strong upper level trough (for August) approaches, combining with seasonal mid-August heat and humidity to produce a risk of severe weather by mid-week. Before that though, I expect Tuesday to be a similar day to Monday with widely scattered "airmass" thunderstorms that pop up, move little, and rain themselves out during the afternoon hours. High temperatures will be similar to Monday and about normal for this time of year - near 90.

Tuesday night begin to see the influence of the approaching trough to our northwest as thunderstorms progress into MO and AR. A chance of rain moves into the Mid-South by early Wednesday, but the best chances of thunderstorms will be during the afternoon and evening hours. Model data is still not quite in line with the timing of the front and subsequent impacts, mainly because the front will be slowing down as it nears the Mid-South as the low "pulling" the front ejects north into Canada. As of Monday night, west TN and northeast AR are under a Marginal Risk (category 1/5) for severe storms Wednesday with the better chances to our north. This will likely change a few time between now and Wednesday afternoon, so stay in touch with MWN for the latest details. The main severe weather threats will be isolated damaging wind gusts and large hail. Wednesday night activities definitely need a rain plan.

Forecast precipitation amounts through Saturday from NOAA's Weather Prediction Center, which indicates 2" or more of rain could fall this week.

A relative lull is expected Thursday as the front stalls over the region and most of the atmospheric dynamics are well removed from the Mid-South. A few showers or a thunderstorm can't be ruled out however. The best part of Thursday will be the temperatures - some areas may barely reach 80° for the high!

Forecast high temperatures for Thursday from the NOAA WPC. While 78° may be a bit cooler than we actually see, temps near 80 would certainly be welcome!
To start the weekend, the front remains stalled over the area but pulls back to the north as a warm front on Sunday. Combined with warmer temperatures, scattered showers and thunderstorms will once again be possible, though it is too far out to pinpoint any more likely times. This time of year though, typically afternoons provide the best chance of thunder.

Surface map valid Saturday morning showing Wednesday night's front still draped across the area, providing a focus for scattered showers and thunderstorms to end the week.
We encourage you to download our mobile apps and follow us on Twitter and Facebook for the latest details and updates on the potential severe weather threat Wednesday. Links are all below.

Erik Proseus
MWN Meteorologist

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