Thursday, July 25, 2013

Better Rain Chances by Saturday

The same weak trough of low pressure that delivered some late-day rains to parts of the area on Wednesday helped spark some early showers and t-storms in our coastal parishes today. Most of that activity shifted offshore by late morning and left behind a mainly dry afternoon for the WAFB viewing area.

Once again today, temperatures have fallen short of forecast readings (I don’t think anyone is complaining!). In fact, highs have only topped out near or slightly above 90° for most, even though we were expecting mid 90°s. Leftover clouds from the morning rains along the coast were at least partially responsible for the lower-than-expected temps.

Our computer guidance is once again forecasting highs in the mid 90°s for Friday, but we have to be somewhat skeptical since the guidance has run above reality just about all week. The 2 models we look at most closely on a daily basis are both forecasting a high of 96° for Baton Rouge on Friday. Given this week’s trends, we’ll undercut that by a couple of degrees and go with 94° and even that could be a reach.

Rain chances stay low on Friday, but a much better chance of showers and t-storms is expected by Saturday. A weak cool front approaching from the north, combined with an upper-air disturbance will lead to at least a 50% chance of showers and t-storms. The clouds and associated rains should keep highs close to 90° for most.

The big question for Sunday’s forecast relates to where the weak cool front eventually stalls. If it makes it to the coast, somewhat drier air would result in lower rain chances. If it stalls near or just north of us, scattered showers and t-storms would remain. For now, we’ll go with a 30% chance of showers and t-storms for the second half of the weekend.

Fairly typical late-July/early-August weather is expected into next week, with hot and humid afternoons and a slight chance of showers and t-storms each day. If anything, rain chances may run a bit below-normal next week.

And we continue to track Tropical Storm Dorian as it makes its way through the Atlantic. After struggling a little bit with slightly cooler water temperatures earlier today, the storm seemed to rebound this afternoon. Maximum winds were still listed at 60 mph as of 4 PM. The official forecast track hasn't really changed much and still has Dorian moving just north of the Lesser Antilles over the weekend before possibly approaching the Bahamas early next week.

We're already getting many 'Is it coming here?' questions. The short answer is it's just too soon to say. Even if it did make it to the Gulf -- and that's a big 'IF' -- it's still probably about a week away from doing so. I did take a look at historical storm tracks this afternoon and the results might surprise you. Since 1850, only 2 tropical systems passing within 150 miles of Dorian's current location made it into the Gulf. That's out of more than 80 depressions, storms and hurricanes during that stretch. The two that did make it to the Gulf included a 1915 hurricane that made landfall near Galveston and 2008's Hurricane Ike. Does that mean Dorian won't make it to the Gulf? Not necessarily. But history tells us the odds are relatively low. Let's hope they hold!

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