Thursday, September 17, 2009

Upper Level Low To Keep Rain Chances in Forecast through the End of the Week...Improvement for the Weekend...Strong Cold Front Next Week!!!

Wednesday, September 16, 2009

SW Louisiana Forecast Discussion...Another day of weather dominated by the pesky persistent upper level low. The low actually strengthened a bit, and moved West today. It is currently positioned in NE Texas between Tyler and Shreveport. It will continue to influence the weather across the area through Friday, before finally getting a boot out of the NE this weekend as a deep trough approaches. The future track of the low is one that will result in increasing rain chances for the next couple of days. A drift to the S or SE is expected through Thursday, and this will bring the upper level low closer to SW Louisiana in the vicinity of Toledo Bend. The low is then forecast to turn to the East and eventually NE on Friday. With the positioning of the upper level low today, some drier air was in place, and this reduced the coverage of shower and thunderstorm activity across the area. This allowed for more sunshine and warmer temperatures across the area with highs in the mid tp upper 80s. Shower and thunderstorm activity was delayed until after 3p.m. across the forecast area, and once again the most numerous activity was across extreme Northern portions of the forecast area closer to the aforementioned low.

As the low drifts towards the forecast area, an increase in cloud cover and shower and thunderstorm activity is forecast for Thursday and Friday with at least half the area seeing rainfall each day. Rainfall amounts will vary, with heaviest amounts and the best chance of showers and thunderstorms across Northern portions of the area. With the increased cloud cover and rain chances, temperatures will be below normal at least for afternoon highs. Morning lows will generally run in the low 70s for Thursday and Friday morning while highs reach the low to mid 80s. The dry air that was over the area today should help to keep Thursday morning dry for the most part, but by afternoon showers and thunderstorms will rotate into the area from the NW around the upper level low. On Friday, with the low making its closest approach to the area a shower or thunderstorm could occur at any time of day as the presence of a dry slot should be displaced from our area, if one exists at that time. Areas to the N and E of the low will continue to have the highest rain chances as the moisture pinwheels around the low with an onshore flow to the East, and an offshore flow to the West.

Over the weekend, the upper level low should finally weaken and nudge ENE out of the area as an advancing trough moves through the Great Plains. A shift in the overall pattern across the country is what is needed to shunt the low out of our way, and this should happen most likely on Sunday. On Saturday, the upper level low will be located NE of our forecast area, and this allow the area to be dry slotted once again around the broad circulation. Thus, rain chances will drop to below normal, but won't be taken out of the forecast entirely. The position of the low will produce an offshore flow across the area, and this will thwart the sea breeze, also aiding in the reduction of rain chances for the weekend. It will still be summer this weekend, with more sunshine expected high temperatures will be close to 90 while morning lows will be around 70...some upper 60s are possible as drier air filters in behind the upper level low. Very similar conditions are expected for both Saturday and Sunday before make changes take place Monday.

On Monday, the upper level low will finally be long gone as it is picked up by the advancing trough and associated cold front. The front will be approaching the area late in the day Monday, and will act as a focus mechanism for showers and thunderstorms Monday afternoon. Therefore, rain chances will increase once again. Cloud cover will increase once again, and winds will shift to off the Gulf once again as it usual ahead of cold fronts. A chance for showers and thunderstorms will carry over into Monday night and Tuesday morning as the front passes through, but conditions will greatly improve on Tuesday. It will be noticeably cooler and drier behind the front, and this will be right on cue with the first day of Fall on Tuesday. Monday will see highs in the mid 80s ahead of the front, and because of the higher rain chances and increased clouds. Very nice weather will round out the forecast period as a true taste of fall moves in. The cool down will start in the wake of the front on Tuesday. Winds will shift from SE to NW and increase behind the front flushing out the humidity, and ending summer. Tuesday lows will be in the 60s and highs in the low 80s with clearing skies during the day, and by the end of the forecast period on Wednesday lows in the 50s for much of the area looks reasonable while highs top out near 80 with Sunny skies and low humidity....aaaaahhhhh! It can't get here fast enough.

Tropics: Thank you, El Nino!!! We are deadlocked in prime time hurricane season, but it's more like the early part or latter part of the season in the Atlantic Basin at this time with no active storms. The environment of the tropical Atlantic remains one that is unfavorable for development due to high amounts of wind shear present, and a larger area of marginal sea surface temperatures. There are a couple of low risk areas as highlighted by the National Hurricane Center, one of which is the remnants of Fred. Each one of these low risk areas is having a hard time getting better organized because of all the shear.


Preliminary Numbers & Zone Forecasts:

LCH   73/83    73/84   71/86      20 40 20 40 20 20
LFT    73/84    73/83   71/86      20 40 20 40 20 20
BPT    75/85   74/85    72/88     20 40 20 30 20 20
AEX   71/82    71/83    68/86    30 60 30 50 20 10
POE   71/81    71/82    68/87    30 60 30 50 20 10
ARA  74/84    73/83    72/86    20 40 20 40 20 20

Tonight...Mostly Cloudy with a slight chance of a shower or thunderstorm. Low 73. Light West wind. Chance of rain 20%.

Thursday...Mostly Cloudy with a 40% chance of showers and thunderstorms. High 83. SW wind 10-15 mph.

Thursday Night...Mostly Cloudy with a 20% chance of a shower or thunderstorm. Low 73. Light SW wind.

Friday...Mostly Cloudy with a 40% chance of showers and thunderstorms. High 84. SW wind 10-15 mph.

Friday Night...Partly Cloudy with a 20% chance of a shower or thunderstorm. Low 71. Light West wind.

Saturday...Partly Cloudy with a 20% chance of showers and thunderstorms. High 86. WNW wind 10-15 mph.


7 Day Outlook for Lake Charles & Vicinity

Thursday
9-17-09




73/83/40
Wind: SW 10-15
H.I.: 88-93
U.V.: 8- High


Friday
9-18-09




73/84/40
Wind: SW 10-15
H.I.: 88-93
U.V.: 8- High


Saturday
9-19-09





71/86/20
Wind: WNW 5-10
H.I.: 90-95
U.V.: 10- High


Sunday
9-20-09





70/88/20
Wind: WSW 10-15
H.I.: 92-97
U.V.: 10- High


Monday
9-21-09





72/85/40
Wind: SSE 10-15
H.I.: 88-93
U.V.: 9- High


Tuesday
9-22-09
Autumnal Equinox





65/82/20
Wind: NNW 15-20
H.I.: N/A
U.V.: 10- High


Wednesday
9-23-09





57/78/0
Wind: NW 5-10
H.I.: N/A
U.V.: 10- High


...Marine Forecast from NWS Lake Charles...

Tonight...West winds 10-15 knots. Seas 1-2 feet. A chance of showers and thunderstorms.

Thursday...West winds around 15 knots. Seas 2-3 feet. A chance of showers and thunderstorms.

Thursday Night...West winds 10-15 knots. Seas 1-3 feet subsiding to 1-2 feet after midnight. A chance of showers and thunderstorms.

Friday...West winds 10-15 knots. Seas 1-2 feet. A chance of showers and thunderstorms.

Friday Night...Northwest winds 10-15 knots. Seas 1-2 feet. A slight chance of showers and thunderstorms.

Saturday...West winds 5-10 knots. Seas 1 foot. A slight chance of showers and thunderstorms.

Tide Data...Tidal Information Provided is for Calcasieu Pass, LA...

Thursday Tides:
Low:  9:15a.m.   9:52p.m.
High:  3:14a.m.   2:10p.m.


...Lake Charles Climate Summary from NWS Lake Charles...

Wednesday, September 16, 2009

Low:              73
Normal Low:  73
Record Low:  53-1902
High:              87
Normal High:  88
Record High:  99-2004

Rainfall:
Today:                           0.00"
Month to Date:               3.64"
Normal Month to Date:   3.28"
Year to Date:                45.36"
Normal Year to Date:    41.37"
Record:                          3.94"-1975

Sunrise Thursday:   6:59a.m.
Sunset Thursday:    7:15p.m.


Good night and God bless!!!
-DM-

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