Monday, September 7, 2015

Finally, a couple of "fall" cold fronts arrive this week!

I hope everyone had a great Labor Day holiday weekend, despite the heat and humidity! This weekend unofficially marks the end of summer and the weather is only a couple of days away from being right on cue.

One more day in the mid 90s with a heat index pushing the century mark is expected Tuesday. As with the last few days, a pop-up "airmass" shower is possible anywhere, but 98% of you won't see a drop.

On Wednesday, the cold front we've been dreaming of, and mentioning, for about a week draws closer. By afternoon, expect scattered thunderstorms to move from our northwest into the metro. The chance of severe weather looks to be fairly low though as the upper level dynamics won't be sufficient to produce more than a brief gust of wind that is typical with storms that move into a very warm airmass. Highs will probably reach the 90° mark. Showers and thunderstorms will remain possible into Wednesday night as the front moves into the metro. This will be the best chance we have had to see widespread rainfall in some time.

Surface map showing fronts and pressure systems, valid Thursday morning. One front is over the Mid-South while a secondary shot of cool air is behind the cold front over the northern Plains, diving south. Map courtesy NWS.

On Thursday, the cold front moves the rest of the way through the region with a chance of showers or a thunderstorm lingering. Temperatures should top out in the mid 80s with a good deal of cloud cover. This front won't be the one that makes the biggest difference in humidity however. After a mostly dry day Friday with highs in the mid 80s, a reinforcing front moves into the area Friday night and Saturday. Computer models now paint a decent chance of showers with this front as well, especially late Friday night into Saturday morning, though our confidence in exact timing and rain amounts remains below average on this front.

Surface map showing high pressure building into the region this weekend. Map courtesy NWS.

 By Sunday and Monday, the fronts are well to our south and cool high pressure takes over from the north. And that means FALL weather! Low humidity, abundant sunshine, and below normal temperatures are expected both days with a fair amount of 50s in the mornings and highs probably in the 80-85° range.  Definitely something to look forward to after some hot days to start September!

Erik Proseus
MWN Meteorologist

Follow MWN on Facebook, Twitter, and Google+
Visit on the web or on your mobile phone.
Download our iPhone or Android apps, featuring StormWatch+ severe weather alerts!

No comments: