Tuesday, October 15, 2013

Showers, Cooler Temps on the Way...

By Jay Grymes & Steve Caparotta

We enjoyed a fairly quiet day today, and there were just enough clouds to keep the day from getting as warm as we had anticipated.
We’ve been talking about a cold front coming into the WAFB area for several days now.  That front is approaching the ArkLaTex region this evening, with its main surface low headed toward the Canadian border.  Radar has been showing a broad band of moderate rains extending from southwest to northeast through Texas and into Arkansas today, the product of the aforementioned front with added lift provided by a very active sub-tropical jet.

With the sub-tropical jet expected to move little from its current position, the cold front won’t get much of a push over the next few days.  As a result, the front will be slow to advance eastward.  We expect the front to move into NW Louisiana around midnight or so tonight, only reach the WAFB viewing area during the latter half of the day on Wednesday, and still be draped over the southeastern parishes as late as Thursday morning.  It will continue to creep to the east and south into Friday, then likely stall over the northern Gulf.
Fortunately for us, the front won’t have much lift or “energy” to work with, so most rain in the area will be light-to-moderate through the coming three days. In fact, we are only posting daily rain chances in the 30% to 40% range for Wednesday, Thursday and Friday, with most WAFB communities coming in at under one-half-inch of rain for their three-day totals.
You’ll also notice the cool-down as a northerly air mass arrives behind the front.  After a high on Wednesday in the mid 80°s for metro Baton Rouge, “Red Stick” highs for Thursday and Friday will be in the upper 70°s thanks to the front’s position to the south and southeast.
Unfortunately, the Gulf front looks like it will begin a northward retreat by late Friday into Saturday, pulling Gulf moisture northward and serving as a focus for another round of rains centered on Saturday into early Sunday.  In fact, Saturday could be a rather wet day for the area, and there is some potential for more in the way of thunderstorm activity.  Widespread severe weather does not appear to be a serious concern as yet, but we’ll have to watch and see how the pattern develops.  In addition, rains of 0.5” to 1.5” could be possible, especially for some of WAFB’s more western communities.

And to be honest, the outlook for Sunday, Monday and Tuesday remains very uncertain.  For now, it looks like a secondary Canadian cold front could arrive and merge with Saturday’s retreating warm front and help clear things out by late Sunday.  However, some of the extended guidance suggests that the resulting frontal system would then stall a second time and retreat again as a warm front for Monday and Tuesday -- keeping scattered rains in the forecast for early next week.  We’ll just have to see how the models respond in the coming days.
Elsewhere ... a broad area of low pressure well east of the Bahamas is the only area of interest in the tropics, and even it has very little chance of developing in the next three to five days.

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