A Bit Warmer This Weekend

By Jay Grymes & Steve Caparotta

WAFB Storm Team QuickCast:

- lots of sunshine for the weekend

- warming trend continues into mid week, at least

- staying dry for the next 7 days or more

Although most WAFB neighborhoods missed seeing another record low this morning, the cool and dry start to the day was still most welcomed.  It’s mid-May: this could well be the end of ‘comfortably cool’ mornings in the 50°s before summer sets-in.

The warming trend we’ve been mentioning over the past several days began today, albeit rather slowly.  We’ll still enjoy a nice spring weekend before you really notice a return of the Gulf humidity.  Our forecast calls for mostly sunny skies for both Saturday and Sunday, with Baton Rouge highs in the mid 80°s for both days.  Saturday morning will see Red Stick sunrise temperatures in the mid to upper 50°s -- not quite as cool as the past two wake-ups -- with a morning start right around 60° for Sunday.

The morning “muggies” will be back by the start of the work week - - we expect a Monday morning minimum in the low 60°s for metro BR.  Sunrises will be in the mid to upper 60°s for the remainder of the work week for the greater capital area with afternoon highs in the mid to upper 80°s for Monday and then returning to the upper 80°s each afternoon through Friday.

Warm, Mainly Dry into Next Week

Yet, again, we see no rain in the outlook through the next 7 days, at least.  In fact, it looks like dry weather will continue through the following weekend as well.  Now admittedly, after a month’s worth of rain (or more) over last weekend, we can certainly afford a dry-out.  We just don’t want to go too long without our next decent rain.

Source of Upcoming Run of Dry Weather?

Why the upcoming dry spell?  Check out the forecast for the jet stream.

The unusually cool start for the past two mornings was courtesy of a deep southward dip in the Polar Jet flow (a trough), allowing cool-and-dry Canadian air to plunge all the way to the northern Gulf.  That trough is now shifting to the east and filling (retreating) to the north.  In its place, the upper-level weather feature that will control our weather is an approaching ridge.  As we’ve discussed over the years, upper-level ridges typically result in warm and mainly-dry weather.  The extended outlook has a broad upper-air ridge moving over the center of the U.S. over the next several days and remaining anchored there through most or all of next week.

Upper-level ridges are characterized by sinking air and that sinking effect acts like a “lid” on the atmosphere, minimizing the ability for daytime heating to generate clouds.  No clouds, no rain.

The sinking air also helps warm the lower levels of the atmosphere (sinking air gets warmer as it descends).  In addition, by reducing cloud development the ridge effectively allows more sunshine to reach the ground, which typically means a bigger daytime warm-up.  With this set-up expected to last right through most or all of next week, we won’t be surprised to see some WAFB neighborhoods reach 90° or more at some time during the latter half of next week.

In the meantime, enjoy the dry weather and weekend sunshine ... and consider a little sunscreen if you’re going to spend a good amount of time under the sun!