SW Louisiana Forecast Discussion...Lots of moisture around tonight! The atmosphere is getting wrung out like a sponge. There are a number of factors that are leading to the enhanced rainfall over the area. Shower and thunderstorm activity was numerous today, and the chances for rain were in the likely category. This pattern will remain with us for another day or two, and then we'll transition to much drier for the second half of the week. Due to the numerous convective activity today, temperatures were at or just below normal across much of the area.
If you think back to last week, the original forecast for today (Monday) was for tropical storm conditions as then Bonnie was forecast to move into Louisiana and over the forecast area. However, the poorly organized tropical system weakened into an open wave off of the SE Louisiana Coast Saturday. The remnant low moved inland between Grand Isle and Buras late Saturday Night. The low then drifted to WNW and then W basically paralleling I-10 through Sunday. It has since completely dissipated, but not before passing over the area and opening up the Gulf to send copious amounts of tropical moisture over the area. This combined with a large upper level low, which helped steer and weaken Bonnie, is situated over Central Texas. The flow around this ULL is also allowing for deep tropical moisture to be pumped into the region. These synoptic scale features combined with the usual effects of daytime heating to produce scattered to numerous shower and thunderstorm activity across the forecast area. Many locations in this situation have seen rain multiple times over the course of the day. There's just so much moisture to get wrung out. Even a little bit of sunshine after it rains, is all it takes for the atmospheric conditions to support additional shower and thunderstorm activity. The trend continues tonight with some ongoing scattered showers & thunderstorms across the area. There are other minor disturbances that are embedded in the deep Gulf flow over the area. Typically, on a normal summer day, all convection wanes by sunset or shortly thereafter. However, in this situation rain chances will continue for the overnight hours as well. Granted, they will certainly be less than what they were during the day. Partly to Mostly Cloudy skies will prevail away from where its raining. The showers and storms will just come and go, bringing brief heavy downpours, and lots of lightning. Rainfall totals have varied across the area with someone receiving nothing, to some locations receiving a real toad-strangler, over 2". Occasional shower and storm activity will be in the offing tonight with a very humid and tropical air mass in place. Low temperatures will hover in the mid to upper 70s, very similar to previous nights. Rain chances around 30-40% seem feasible given the rich, tropical atmosphere.
High rain chances will continue for Tuesday as the tropically laden atmosphere continues to engulf the area.The same synoptic features from Monday will essentially be in place on Tuesday. The aforementioned upper level low will remain in place over Texas, and another upper level low (non-tropical) will traverse the Gulf of Mexico waters from East to West, and move in our general direction. The flow along the Gulf coast should steer this feature towards our area. Activity will be most prominent during the peak heating hours of the afternoon, but rainfall will certainly not be limited to the afternoon hours. Showers and storms will likely abate over land for the most part for the early morning hours, but additional convection will fire up over the coastal waters in the overnight and early morning hours as the additional synoptic feature approaches. Partly to Mostly Cloudy skies should greet most as we start the day Tuesday, but there will likely be a few nocturnals or "early-risers' out there. The offshore convection will expand in coverage, and move inland as the morning progresses, becoming numerous by afternoon. Rainfall will be heavy at times, and this poses the possibility of some localized urban flooding. We are still in drought conditions across much of the forecast area, but often times when it comes down this time of year, especially in a high atmospheric moisture content situation, it comes down too fast and too furious. So, even though we are technically in drought conditions, the heavy rainfall threat is prime for some of the usual urban flooding. Some locations will once again stand to receive over 1" of rain, with a few receiving about 2". It just depends on who receives a direct hit, and who just gets sideswiped. Again, it will be another day where it might rain more than once at any given location. The extra cloud cover and enhanced rain chances will keep temperatures in check. Highs should only reach around normal levels or slightly less with upper 80s to around 90 a good call. The deep onshore flow will continue with SE winds in the 10-15 mph range. Gusty winds over 30 mph will be possible in storms. Activity will simmer down as the sun goes down, but again I still can't rule out some nocturnal activity heading into Wednesday morning.
The established synoptic scale features will begin to break down on Wednesday, but it will still be a very moisture laden atmosphere. Daytime heating will combine with the continued deep Southerly flow and the departing secondary upper level low to produce another decent chance of showers and thunderstorms, although coverage will be a bit less. The strong ridge of high pressure that has visited us from time to time this summer will begin to strengthen and build towards the area once again. This will start to usher in some drier air in the middle and upper levels of the atmosphere. A set up similar to Tuesday should occur in that convective will build up over the coastal waters in the morning, and head inland and expand in coverage for the afternoon hours. With the drier air beginning to punch in from the NE, the convection should be more scattered in nature as opposed to numerous. Temperatures will be around normal to perhaps slightly above given the fact that there should be a little more sunshine than the previous days. All convection wanes by sunset, and with the drier air taking over nocturnal convection should be absent for the Wednesday night-Thursday morning period. Overnight lows will continue to be in the mid to upper 70s...sounds like deja vu to me.
The remainder of the forecast period will be much less active. The bid ridge of high pressure becomes the dominate weather feature by Thursday, and the chances of any thermally induced thunderstorms will be nearly scant to none. Surely, there could be a few that bust through the cap, and cool off a few select people, but as a general rule a much drier regime is in store. Temperatures will respond as well with readings topping out in the mid 90s...you guessed it back to above the norm for late July. Heat indices will also make like Emeril and kick it up a notch, reaching very close to the danger level of 105. The ridge only intensifies for Friday and the weekend, and should be oriented from NE to SW across the area, and will likely be centered somewhere in SE Louisiana or Western Mississippi by Thursday before drifting further West by Friday into the weekend. This will help to dry out the atmosphere even further, and there will be virtually no chance of any relief for the Friday-Monday period. Temperatures will be very hot, and certainly above normal for late July and early August. Some of the hottest, perhaps the hottest weather we've seen all summer is on tap. Many locations will exceed 100 degrees beginning Friday, and lasting through the rest of the forecast period. Upper 90s should be the average for high temperatures this weekend, and while it is not currently reflected it is certainly feasible that temperatures could exceed the 100 degree mark even here in Lake Charles at some point between Friday and Monday. Heat indices will soar into the 105-110 range, this is bordering on Heat Advisory criteria. Hard to believe we'll be into August this weekend, and it'll certainly feel like it. This pattern is good for one thing...blocking any tropical systems from coming our way. Looking into the extended, the first week of August will continue to be very hot and dry, with some signs of the ridge breaking down over the area once again towards the latter half of the first full week of August. August begins the period known as prime time hurricane season, so we'll have to wait and see what is in store in the tropics.
Preliminary Numbers & Zone Forecast:
LCH 76/89 76/92 75/95 40 70 30 60 10 20
LFT 76/90 76/92 75/95 40 70 30 60 10 20
BPT 77/88 76/91 75/94 40 70 30 60 10 20
AEX 75/90 74/94 73/98 40 70 30 60 10 20
POE 75/90 74/94 74/98 40 70 30 60 10 20
ARA 77/88 77/91 76/94 40 70 30 60 10 20
Tonight...Mostly Cloudy with a 40% chance of showers & thunderstorms. Low 76. SSE wind 5-10 mph.
Tuesday...Mostly Cloudy with showers & thunderstorms likely. Most numerous in the afternoon. Heavy rainfall at times. High 89. SSE wind 10-15 mph. Chance of rain 70%.
Tuesday Night...Mostly Cloudy with a 30% chance of showers & thunderstorms mainly before midnight. Low 76. SSE wind 5-10 mph.
Wednesday...Partly to Mostly Cloudy with showers & thunderstorms likely once again. Some heavy rainfall possible. High 92. SSE wind 10-15 mph. Chance of rain 60%.
Wednesday Night...Partly Cloudy. Low 75. Light South Wind.
Thursday...Partly Cloudy with a 20% chance of scattered afternoon showers & thunderstorms. High 94. South wind 10-15 mph.
Tuesday 7/27/10 Daily Planner
6a.m.
Weather: Mostly Cloudy, Some Storms Near the Coast
Temp: 76
Rain: 40%
Wind: SSE 6
9a.m.
Weather: Mostly Cloudy, Showers & Storms Spreading Inland
Temp: 80
Rain: 40%
Wind: SSE 8
H.I.: 88
Noon
Weather: Mostly Cloudy, Numerous Showers & Storms
Temp: 85
Rain: 60%
H.I.: 95
3p.m.
Weather: Showers & T-Storms Likely
Temp: 89
Rain: 70%
Wind: SSE 15
H.I.: 98
6p.m.
Weather: Mostly Cloudy, Scattered to Numerous Storms
Temp: 85
Rain: 60%
Wind: SSE 12
H.I.: 96
9p.m.
Weather: Mostly Cloudy, A Few Leftover Storms Possible
Temp: 82
Rain: 30%
Wind: SSE 4
Drew's 7 Day Outlook
Tuesday
7-27-10
Low: 76
High: 89
Rain: 70%
Wind: SSE 10-15
H.I.: 93-98
U.V.: 8- High
Wednesday
7-28-10
Low: 76
High: 92
Rain: 60%
Wind: SSE 10-15
H.I.: 97-102
U.V.: 9- High
Thursday
7-29-10
Low: 75
High: 95
Rain: 20%
Wind: S 10-15
H.I.: 100-105
U.V.: 10- High
Friday
7-30-10
Low: 75
High: 98
Rain: 10%
Wind: SSW 10-15
H.I.: 103-108
U.V.: 11- Very High
Saturday
7-31-10
Low: 76
High: 99
Rain: 0%
Wind: SSW 10-15
H.I.: 105-110
U.V.: 11- Very High
Sunday
Low: 76
High: 99
Rain: 0%
Wind: SSW 10-15
H.I.: 105-110
U.V.: 11- Very High
Monday
8-2-10
Low: 75
High: 98
Rain: 0%
Wind: SSW 10-15
H.I.: 105-110
U.V.: 11- Very High
...Tropical Update...
The tropics are quiet at this time. No tropical cyclone formation is expected through Wednesday.
...Marine Forecast...
Rest Of Tonight...South winds 10 to 15 knots. Seas 2 feet. A chance of showers and thunderstorms.
Tuesday...South winds 5 to 10 knots increasing to 10 to 15 knots in the afternoon. Seas 2 feet. Showers and thunderstorms likely.
Tuesday Night...South winds 10 to 15 knots. Seas 2 to 3 feet. A chance of showers and thunderstorms.
Wednesday...South winds around 10 knots. Seas 2 to 3 feet. A chance of showers and thunderstorms.
Wednesday Night...South winds 5 to 10 knots. Seas 2 to 3 feet. A slight chance of showers and thunderstorms.
Thursday...Southwest winds 5 to 10 knots. Seas 2 feet.
...Tide Data...
Tuesday Tides @ Calcasieu Pass
Low: 11:00a.m. 10:32p.m.
High: 6:06a.m. 3:13p.m.
...Toledo Bend Pool Level...
168..00'
...Lake Charles Climate Summary...
Monday, July 26, 2010
Low: 77
Normal Low: 75
Record Low: 64-1915
High: 91
Normal High: 91
Record High: 101-1912
Rainfall
Today: 1.08"
Month to Date: 4.51"
Normal Month to Date: 4.38"
Year to Date: 20.03"
Normal Year to Date: 32.49"
Record: 5.18"-2006
Sensible Weather Observed Today:
Thunderstorm
Heavy Rain
Rain
Light Rain
One Year Ago (2009)
Low: 71
High: 91
Rain: 0.35"
5 Years Ago (2005)
Low: 77
High: 93
Rain: 0.00"
10 Years Ago (2000)
Low: 70
High: 93
Rain: 0.00"
Sunrise Tuesday: 6:29a.m.
Sunset Tuesday: 8:10p.m.
...Lunar Table...
Full Moon- Tonight July 26
Last Quarter- Tuesday August 3
New Moon- Tuesday August 10
First Quarter- Monday August 16
Have a Great Tuesday & God Bless!
-DM-
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