Monday, August 18, 2014

Hottest Week of the Summer Ahead?

By Jay Grymes & Steve Caparotta

WAFB First Alert Quickcast:

- limited chances for showers this week
- mid 90°s likely … could see some upper 90°s
Just about everyone reached the low 90°s over the weekend but scattered showers and storms served as the main weather features for many on Saturday and Sunday.  It was back into the 90°s again today, although the rain coverage wasn’t nearly as widespread as during the weekend. 
Rain chances will stay on the low side this week; climatology tells us that, on average, we should expect about a 40% rain chance each day during August.  However, our daily forecasted percentages through Sunday will be half that or less.  We won’t say “completely dry” across the region, but we don’t expect any days where rain chances top 20% or so. 
Now remember, that does not mean you will go rain free through the week, nor does it rule out isolated downpours where slow-moving thunderstorms develop.  But most of you will stay on the dry site this week -- keep in mind that with this summer heat, the yards and gardens would like to get about 1” of rain (or more) every five to seven days.  Very few will see anything like that through the weekend.
We’ll have no fronts to deal with through the coming week and weekend as an upper-air ridge (high pressure aloft) builds over the lower Mississippi Valley and U.S. Southeast from the east.  Heat and humidity will remain in place, with morning lows in the muggy mid-70°s for many WAFB communities while afternoons turn into real “cookers” with widespread highs in the mid 90°s and Heat Index readings well into the triple-digits.  In fact, many in our viewing area may experience the summer’s first upper 90°s -- it’s shaping up to be the ‘hottest’ spell of the summer thus far.

You know how these upper-air ridges usually work: they put a lid on the atmosphere which not only knocks down rain chances but even cuts down on cloud development.  Less cloud cover means more sunshine and more daytime heating.  The upper-high also generates sinking air, and sinking air gets warmer as it descends, adding to the surface heating.  Then toss in nights that fail to cool down much along with our normal August Gulf humidity in the lowest levels and you’ve got the ingredients for some uncomfortably-muggy mornings and downright oppressive afternoons.
Come on October!  Not much else to say except be careful and be smart in the heat!
In the tropics, the National Hurricane Center (NHC) is watching a poorly-defined tropical wave in the central Atlantic, roughly mid-way between the Lesser Antilles and the Cape Verde Islands.  Models are a bit mixed currently as to what to make of its future but as of this afternoon the NHC remains unimpressed, giving it just a 10% chance for becoming a tropical cyclone (depression or stronger) over the next 5 days.  Frankly, we think that the wave behind it (farther to the east) deserves greater interest: look for the NHC to comment on it within the next 12-24 hours.

No comments:

Post a Comment