Wednesday, August 8, 2012

August 'Cool' Front?

By Jay Grymes & Steve Caparotta


Titan9 Doppler has been tracking one of the more “textbook” seabreeze fronts we’ve seen over south Louisiana in quite some time.  The line started taking shape before lunchtime and continued tracking northward at about 15 mph through the early afternoon, arriving along the I-10/12 corridor a little after 2PM.  Although none of the storms in the northbound line reached ‘severe’ status, locally-heavy rains over several southeastern parishes prompted the NWS to post local Flood Advisories for a number of communities. 
As well-defined as the line was at 1PM, by 2PM it was weakening, and all but collapsed between 2-3PM ... before reaching the Baton Rouge area.  That will leave the WAFB viewing area with a few showers and isolated t-storms for the remainder of the afternoon and early evening, with most, if not all, of the rains dying out by or before sunset.
We’re raising rain chances a bit for Thursday -- to 40% -- and going with a 50-50 chance for rains on Friday.  It looks like a ‘cool front’ will try to dip all the way down into our viewing area from Friday into Saturday.

To be honest, Jay was a little skeptical that the front would get this far south, but after two days of runs suggesting that it could get at least as far south as the Florida Parishes, he’ll “bite” on that projection today.  But the front does not look to get much farther south than that, and it likely only gets that far for a handful of hours before becoming stationary and then beginning a northbound retreat.  As the front approaches, we expect to see a modest and welcomed dip in dew points (slight surge of drier air).
The outlook for Saturday will be dependent on the details and position of the front: we’re thinking that Saturday will be dry for most neighborhoods but with a sun/cloud mix through the day.  But the forecast for Sunday looks very promising!
Ernesto made landfall early this morning and was downgraded to a tropical storm by 4AM.  ‘He’ has spent the entire day over land during his westward trek across the Yucatan, and that has produced additional weakening.  As of about 3PM, the center of the system appeared to be emerging over the extreme southern Bay of Campeche, and that may allow for some modest re-intensification tonight and tomorrow.  But given the forecast calling for the center to hug the coast, the feeling is now that Ernesto would not be over the water long enough to return to hurricane strength before ‘his’ second Mexico landfall -- likely somewhere to the south of Veracruz.

The remnants of Florence still linger over the central Atlantic, but shearing winds and cooler waters will keep that system from re-developing.  Farther to the east, a very large tropical wave -- “Invest 92L” -- continues to show limited signs of slowly coming together.  We’ll likely be watching that disturbance for many days to come.

No comments:

Post a Comment