Tuesday, September 11, 2012

Humidity Returning...

By Jay Grymes & Steve Caparotta

Tuesday turned out to be another good-looking weather day and still had a touch of the fall feel, but did you notice that Gulf humidity has begun to return to our viewing area. The Tuesday morning low at Baton Rouge’s Metro Airport dipped to 61°, but we expect Wednesday’s low to by 5° to 6° warmer, a reflection of rising dew points (increasing humidity).

Wednesday’s high will approach 90° for many WAFB neighborhoods, and the southeasterly flow -- bringing in more Gulf moisture -- should assure partly cloudy skies. In fact, we think we’ll see a few blips on Titan9 Doppler by the afternoon, but they should be spotty at best: set Wednesday afternoon’s rain chances at less than 20%.

We’re going with 20% rain chances for Thursday and Friday, with scattered afternoon showers (roughly 30% rain chance) for Saturday. Highs all three days will be around 90° with morning lows in the upper 60°s to around 70° -- that will mean a summer-like feel to the air as we head into the weekend.

For now, Sunday looks like it will be the “wettest” day of the coming 7-day period with rain chances currently running at about 50% or so, but we’ll have to see how things settle-out with the forecasted cool front. Yesterday it was looking like the front would make it into Louisiana, then essentially fizzle out over the state. The latest surface charts from the NWS suggest that the front may hold together a little longer, and slowly slip southward to the coastal waters by late Monday or early Tuesday. If that happens, we’ll keep rain chances elevated for Sunday and Monday.

In the tropics, we finally say goodbye to Leslie as she heads over colder North Atlantic waters and moves NE and away from Newfoundland. And it’s goodbye for Michael as well, becoming a remnant low after being impacted by strong shear over the past 24 hours coupled with passage over cooler waters that effectively killed Michael’s convective activity.

Never fear, storm lovers -- newly designated T.D. #14 is spinning over the tropical Atlantic, and is likely to become Nadine over the next day. But the good news is that current guidance keeps #14/Nadine over the open Atlantic.


  1. This season has been active! What happened to the below average season that was predicted by the NHC?

  2. Actually, NOAA forecasted a near-normal season back in May and stuck with near-normal in early August, but increased the chances of an 'above-normal' season in that update. http://www.noaanews.noaa.gov/stories2012/20120809_atlantic_hurricane_season_update.html

    However, simply looking at the number of storms doesn't tell the full story. Many of this year's storms have been relatively weak and short-lived.

    Another measuring stick for hurricane seasons is something known as Accumulated Cyclone Energy (ACE). That index is a reflection of both the intensity and duration of a tropical system. And when looking at the ACE index for 2012, it's barely into the 'near normal' category with a value of 73. It has a ways to go before reaching the 'above normal' category, despite the high number of storms this year. http://en.wikipedia.org/wiki/Accumulated_cyclone_energy#Atlantic_hurricane_seasons_by_ACE_index.2C_1950.E2.80.932012