Sunday, August 9, 2009

Drying Out, Heating Up Again This Week...Tropics Heating Up???

Sunday, August 9, 2009

SW Louisiana Forecast Discussion...It's a fairly typical August Sunday night across the forecast area, but it is an active night across our great nation with several lines of showers and thunderstorms (MCS) ongoing at this time with some severe weather. These areas stretch from SW Texas all the way into Canada, and then bending into New York state. This is along a frontal boundary slowly moving across the country. Rain chances increased some over the weekend as the predominant, controlling high pressure system was anchored off to our East. This allowed for a deep flow of tropical air from the Gulf to infiltrate the region. This combined with a stalled front off to our North, a good scattering of showers and thunderstorms was prevalent both Saturday and Sunday. This will be changing over the course of the work week. Temperatures today were near average with the enhanced rainfall coverage.

A typical August night is in store with the exception of a few nocturnal thunderstorms developing offshore after midnight. Coastal sections of the forecast area may get a heavy downpour from one of these around sunrise, but they shouldn't move too far inland, and will fizzle out as they do so. The deep tropical, moist, unstable air mass is forecast to remain in place for Monday. However, it will be a day of transition as the high shifts back towards our area. Rain chances will be at or above normal for one more day before drier and hotter weather ensues on Tuesday. With the encroachment of the high, some capping processes will be present Monday to help reduce rain chances from what they were today. After seasonal morning lows in the mid to upper 70s, expect Monday highs to be in the mid 90s.

Temperatures heat up into the mid to upper 90s for the rest of the work week, and rain chances will range from normal to below normal. The deep moisture in place now will be slow to vacate the region, but dry air in the upper levels thanks to the placement of the high will reduce the rain chances. What that means basically is this: we will see about normal coverage of shower and thunderstorm activity Tuesday and Wednesday, but it will take longer for vertical growth of cumulus clouds to occur, and shower and thunderstorm activity should be limited to mainly between 3p.m. and 7p.m. as opposed to as early as late morning like we've seen this weekend. The convective temperatures will be higher with the drier air in place, therefore, this is why I expect a later arrival of the usual scattered thunderstorm activity. Expect this to be the story for Tuesday. Some nocturnal activity can't be ruled out during this time as well.

The middle to latter portion of the forecast period continues the drying trend with only a slight chance of a shower or thunderstorm by Wednesday through Friday as the ridge strengthens once again. Temperatures will be above normal during this period with mid to upper 90s across the board, with a few 100s possible across northern extremities of the forecast area. Sea breeze activity will be limited at this time, but the chances for showers and thunderstorms certainly can't be entirely eliminated from the forecast. The afternoon heat indices will be the main issue with readings as high as 105 most afternoons through the period.

Next weekend, as we head into mid-August already, a typical mid-August scenario is expected. A battle between the persistent Desert SW Ridge and the persistent Bermuda High will take place. The Desert high shifts West, and the Bermuda High builds in across the SE U.S. This puts us in a favorable set up for a deep Gulf flow similar to that of this weekend, but with the big ridge in closer proximity and in a stronger state, rain chances should be no greater than normal as of this time. This is always subject to change depending on movement of the highs and the usual daily variances associated with our stagnant summer pattern. Temperatures will moderate slightly back to near normal to slightly above normal ranging from the low to mid 90s. A typical summer pattern looks to remain in place well into next week.

In the tropics...things are likely going to be heating up this week. A very healthy tropical wave emerged off the coast of Africa late last week, and is now near the Cape Verde Islands. This system has potential to development into the first named storm of the season over the next couple of days. It is moving into an environment that favors development, so we'll see. It is moving to the West at 10-15 mph. It is thousands of miles away from the mainland U.S., and 2 weeks from even being a threat in the Gulf, if it ever is at all. There are far too many scenarios for this system at this point, to make any kind of speculation about where it will go. Elsewhere, in the Atlantic Basin, no tropical storm formation is expected through Tuesday.












In other tropical news, Felicia, once a category 4 hurricane in the Eastern Pacific, has been weakening for the last several days as it moves into colder waters, and approaches Hawaii. It currently has 50 mph winds, and will slowly continue to weaken for the next few days, and will bring tropical storm conditions to much of the Hawaiian Islands by late Monday into Tuesday. A Tropical Storm Watch is effect for Molokai, Lanai, Maui, Kahoolawe, Big Island, Maui County Waters, and Big Island Waters in Hawaii. The latest forecast track on Felicia follows:
















Prime time hurricane season is just about here now, so things are likely going to heat up. It is August now, and we've not had the first named storm of the season yet, this is very typical of an El Nino year. 1992 is a prime example of an El Nino season. Hurricane Andrew didn't form until the middle of August.


Preliminary Numbers and Zone Forecast Follows:

LCH 76/94 75/95 76/96 10 40 10 30 0 20
LFT 76/93 76/95 77/95 10 40 10 30 0 20

AEX 74/95 74/98 75/98 0 30 0 20 0 10
BPT 75/95 75/96 75/97 10 40 10 30 0 20

ARA 76/93 75/94 76/95 10 40 10 30 0 20
POE 74/95 74/97 75/98 0 30 0 20 0 10

Tonight...Mostly Clear. An isolated early morning thunderstorm near the coast possible. Low 76. Light South wind.

Monday...Partly Cloudy with a 40% chance of scattered afternoon showers and thunderstorms. High 94. South wind 10 mph.

Monday Night...Mostly Clear. Low 75. Light South wind.

Tuesday...Mostly Sunny to Partly Cloudy with a 30% chance of scattered afternoon showers and thunderstorms. High 95. South wind 10 mph. Heat index near 105 in the afternoon.

Tuesday Night...Clear. Low 76. Light South wind.

Wednesday...Mostly Sunny to Partly Cloudy with a 20% chance of scattered afternoon showers and thunderstorms. High 96. South wind 10 mph. Heat index near 105 in the afternoon.

7 Day Outlook for Lake Charles & Vicinity

Monday
8-10-09







76/94/40
Wind: South 10
H.I.: 98-103
U.V.: 11- Very High



Tuesday
8-11-09







75/95/30
Wind: South 10
H.I.: 100-105
U.V.: 11- Very High


Wednesday
8-12-09






76/96/20
Wind: South 10
H.I.: 100-105
U.V.: 11- Very High


Thursday
8-13-09







76/95/20

Wind: South 10
H.I.: 100-105
U.V.: 11- Very High


Friday
8-14-09






75/95/20

Wind: South 10
H.I.: 100-105
U.V.: 11- Very High


Saturday
8-15-09






75/93/30

Wind: SE 10-15
H.I.: 98-103
U.V.: 11- Very High


Sunday
8-16-09






77/93/30

Wind: SE 10-15
H.I: 97-102
U.V.: 11- Very High



Marine Forecast:

Tonight...South wind 10-15 knots. Seas 1-2 feet.
Isolated Showers & T-Storms after
midnight.

Monday...South wind 5-10 knots. Seas 1-2 feet.
A Chance of Showers & T-Storms.


Monday Night...SW wind 5-10 knots. Seas 1-2 feet.
Slight chance of showers & T-Storms.


Tuesday...SW wind 5-10 knots. Seas 1-2 feet.
A Chance of Showers & T-Storms.


Tuesday Night...SW wind 5-10 knots. Seas 1-2 feet.
Slight chance of Showers & T-Storms.


Wednesday...SW wind 5-10 knots. Seas 1-3 feet.
Slight chance of Showers & T-Storms.



Lake Charles Climate Data for Sunday, August 9, 2009:

Low: 78 Normal Low: 74 Record Low: 61-1990
High: 91 Normal High: 92 Record High: 104-1935

Rainfall Today: 0.38"
Month: 1.08" Normal Month to Date: 1.30"
Year: 34.79" Normal Year to Date: 34.54"

Sunrise Monday: 6:37 a.m.
Sunset Monday: 7:59p.m.

-DM-



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