SW Louisiana Forecast Discussion...It was a decent April day across the forecast area. Mostly Cloudy skies prevailed this morning, but this gave away to Partly Cloudy skies during the afternoon after some mid and high level cloudiness vacated the region. This was in the wake of a now diffuse cold front which moved into the area on Sunday and a departing short wave over the Gulf. Drier air gradually filtered into the region through the day, and this helped to create the decrease in cloud cover. Temperatures once again teasing normal with lows around 60 and highs in the upper 70s across the forecast area. A quiet night is in store with Mostly Clear and perhaps some patchy fog somewhere in the area, but fog should not be of consequence. It will a seasonable night with temperatures falling into the mid to upper 50s. This quiet weather will prevail for the next couple of days as high pressure dominates.
The dry spring of 2010 will continue for the next couple of days. Wednesday will be another in a prolonged stretch of uneventful weather days with high pressure the dominating force. Expect skies to range from Mostly Sunny to Partly Cloudy, and after a seasonably cool start expect afternoon highs to tease the 80 degree threshold once again. High pressure in control in the mid and upper levels will keep dry air in place, and ultimately thwart any chance of rain despite an onshore flow at the surface. This onshore flow will create enough low-level moisture for the formation of some fairweather cumulus clouds during the afternoon. In other words, it'll be very similar to the weather pattern we've seen for much of the month of April. Why should it change now, right? While the benign weather continues around these parts, another Pacific storm will be getting revved up out to our West. Ahead of this, much of the same weather is anticipated for Thursday (Earth Day). The upper level high will strengthen a bit for Thursday keeping the area high and dry, and temperatures will be on the upswing. Seasonable warmth will continue.
The potential bust to the dry pattern will occur beginning Friday as the Pacific storm moves Eastward, and encroaches the area. We will begin to see the effects of this system by Thursday night as the upper level flow shifts and becomes SW, thus resulting in an increase in moisture at low levels with the surface onshore flow already established. It'll remain dry, but temperatures will be above normal, and cloud cover will be increasing. Also, you will certainly notice the humidity by this time. This carries over into Friday, when we'll see very windy conditions develop as well. A very strong Jet Stream will be developing out ahead of the advancing Pacific storm, and a severe weather outbreak is expected on Friday over parts of the Great Plains and a large portion of Tornado Alley. Here, locally, it will certainly be a day of transition as conditions deteriorate through the day. The morning hours will be Partly Cloudy while it transitions to Mostly Cloudy by the afternoon hours. Rain chances will return during the afternoon as deeper moisture moves in over the area ahead of the advancing Pacific storm. The set up favors scattered activity with showers and thunderstorms expected for the afternoon and evening hours of Friday. The effects of daytime heating and the active Jet will factor into the equation. No severe weather is expected over our area on Friday, but certainly a chance of showers and thunderstorms will need to be inserted into the forecast. The temperature regime as we round out the work week is one that will be above normal with morning lows in the mid 60s while afternoon highs will be around 80, which is just slightly above the norm. Winds will be quite strong increasing to over 20 mph at times especially during the afternoon.
That brings us to Saturday...this is when the Pacific storm will be moving through the area. The Jet Stream energy in place will likely result in Southern Plains cyclogenesis on Friday. Additional Jet Stream energy streaming over the area from Mexico may initiate Gulf cyclogenesis ahead of the advancing front Saturday. Whatever the case may be, there certainly appears to be enough dynamics in place as predicted by models that some heavy rain and severe weather will be possible. Favorable Jet dynamics and a shear environment with the presence of a surface low will lead to the possible severe weather outbreak. The forecast area has virtually been null and void of severe weather activity all Spring so far, but our luck could run out on Saturday. There is plenty of time to re-evaluate this situation, and you can bet that this will certainly be the case. The front will have very good support, and whether there is severe weather or not, thunderstorms seem likely on Saturday. It is a set up that will favor an MCS moving across the area during the day on Saturday. This MCS (squall line) will develop over Texas on Friday night, and translate Eastward crossing through the forecast area during the day Saturday. There is certainly still some timing issues with regards to the expectant MCS, but again this will be re-assessed in future forecasts. All modes of severe weather will be possible, and at this time it appears the greatest overall threat will be North of the I-10 corridor. The main threat in this forecast area will likely be damaging wind and large hail. Isolated tornadoes will certainly be possible as well based on this evening's (Tuesday) analysis. Models are in fairly good agreement on the dynamics of the situation, but the usual timing differences arise. At this time, I will hone in on an ETA of noon-3p.m. for the MCS. This certainly looks like a daytime event. The added ingredient of daytime or convective heating will have to be considered as well when examining severe weather ramifications. Severe weather or not, Saturday certainly looks like the best opportunity for rain around these parts in a few weeks, and I will depict rain chances in the likely category at this time. Rainfall amounts could be in the 1-2" range. I'll start showing rainfall and severe weather graphics tomorrow. I know there's a lot of weekend plans and activities going on this weekend, but we do need the rain. We don't need the severe weather, and of course timing of crucial, so stay tuned. Rain and storms should end Saturday afternoon/evening, setting the stage for a pleasant end to the weekend with drier not cooler air filtering in behind the Pacific boundary. Saturday temperatures will remain above normal with lows well above normal possibly only around 70. Highs will easily exceed 80 once again. I'd almost hesitate to call this boundary a cold front, it'll really be more or less a wind shift line/dew point front.
For the end of the forecast period Sunday-Tuesday...A return of benign weather is expected as a new area of high pressure establishes itself in the wake of Saturday's storm system. Skies should clear out Saturday night, and stay clear for Sunday and Monday with a pleasant offshore flow. Highs will climb into the upper 70s to lower 80s range, and lows will be in the mid 50s to lower 60s. This is essentially seasonal for late April. The controlling high will likely shift Eastward by late Monday, but the return flow that commences as a result Monday afternoon will likely remain inconsequential until Tuesday. Some fairweather cumulus clouds will likely develop by Tuesday afternoon with a more noticeable amount of low-level moisture in place, but riding in the mid and upper levels will keep rain chances out of the equation for this period. The average to slightly above average temperature regime will continue. The dry pattern may persist for most of next week, with models advertising the potential for another potential severe weather outbreak around the 1st of May. Can you believe we're talking about May? One starts to wonder when we'll see our last true cold front of the season. You know summer isn't far away now, and even though it officially doesn't begin until June 21st, we all know it starts a lot sooner than that here.
Preliminary Numbers & Zone Forecast:
LCH 55/80 59/82 62/80 0 0 0 0 0 30
LFT 55/81 58/81 61/81 0 0 0 0 0 30
BPT 57/82 60/83 63/80 0 0 0 0 0 40
AEX 53/77 57/83 59/82 0 0 0 0 0 30
POE 54/78 58/83 59/82 0 0 0 0 0 30
ARA 58/81 60/81 63/80 0 0 0 0 0 30
Overnight...Mostly Clear. Low 55. Light East wind.
Wednesday...Partly Cloudy. High 80. SE wind 10-15 mph.
Wednesday Night...Mostly Clear. Low 59. SE wind 5-10 mph.
Thursday...Partly Cloudy. High 82. SSE wind 10-15 mph.
Thursday Night...Partly Cloudy. Low 62. SSE wind 10 mph.
Friday...Partly to Mostly Cloudy & Windy with a 30% chance of showers & thunderstorms in the afternoon. High 80. SSE wind 20-25 mph and gusty.
Wednesday 4/21/10 Daily Planner
6a.m.
Weather: Clear
Temp: 55
Rain: 0%
Wind: E 3
9a.m.
Weather: Sunny
Temp: 68
Rain: 0%
Wind: SE 7
Noon
Weather: Mostly Sunny
Temp: 75
Rain: 0%
Wind: SE 12
3p.m.
Weather: Partly Cloudy
Temp: 80
Rain: 0%
Wind: SSE 15
6p.m.
Weather: Partly Cloudy
Temp: 75
Rain: 0%
Wind: SSE 11
9p.m.
Weather: Partly Cloudy
Temp: 67
Rain: 0%
Wind: SSE 7
Drew's 7 Day Outlook
Wednesday
4-21-10
Low: 55
High: 80
Rain: 0%
Wind: SE 10-15
Thursday
4-22-10
Earth Day
Low: 59
High: 82
Rain: 0%
Wind: SE 10-15
Friday
4-23-10
Low: 63
High: 80
Rain: 30%
Wind: SSE 20-25
Saturday
4-24-10
Low: 67
High: 81
Rain: 70%
Wind: SSE/SSW 20-25
Sunday
4-25-10
Low: 60
High: 80
Rain: 0%
Wind: W 10-15
Monday
4-26-10
Low: 58
High: 83
Rain: 0%
Wind: SW 10-15
Tuesday
4-27-10
Low: 59
High: 83
Rain: 0%
Wind: S 10-15
...Marine Forecast....
Wednesday...East winds 5 to 10 knots becoming southeast in the afternoon. Seas 1 foot.
Wednesday Night...South winds around 10 knots. Seas 1 to 2 feet.
Thursday...Southeast winds 10 to 15 knots. Seas 2 to 3 feet.
Thursday Night...Southeast winds 15 to 20 knots. Seas 2 to 3 feet building to 3 to 4 feet after midnight.
Friday...South winds 15 to 20 knots. Seas 4 to 5 feet. A chance of showers and thunderstorms.
Saturday...Southwest winds 15 to 20 knots. Seas 3 to 5 feet. A chance of showers and thunderstorms.
...Tide Data...
Wednesday Tides @ Calcasieu Pass
Low: 2:22a.m.
High: 10:42a.m.
...Toledo Bend...
170.70'
...Lake Charles Climate Summary...
Tuesday, April 20, 2010
Low: 60
Normal Low: 58
Record Low: 40- 1910
High: 77
Normal High: 78
Record High: 89- 1987
Rainfall
Today: 0.00"
Month to Date: 0.06"
Normal Month to Date: 2.25"
Year to Date: 9.34"
Normal Year to Date: 14.59"
Record: 3.79"- 1979
Sensible Weather Observed Today:
None
One Year Ago (2009)
Low: 55
High: 77
Rain: 0.00"
5 Years Ago (2005)
Low: 63
High: 81
Rain: 0.00"
10 Years Ago (2000)
Low: 60
High: 83
Rain: Trace
Sunrise Wednesday: 6:40a.m.
Sunset Wednesday: 7:44p.m.
...Lunar Table...
First Quarter- Wednesday 21
Full Moon- Wednesday April 28
Last Quarter- Thursday May 6
New Moon- Friday May 14
This Date in Weather History: April 20: 1920...219 people are killed in tornado outbreak in Dixie. Aberdeen, MS is hard hit by an F4 tornado that killed 22 people along the western edge of town. The same tornado killed 20 people in Marion County, AL including 9 at Bexar. 19 people died in Franklin County, AL & 9 of these were from one family.
1990: A fast moving Pacific storm produced heavy snow in the central mountains and the Upper Arkansas Valley of Colorado, with a foot of snow reported at Leadville. Thunderstorms in the south central U.S. produced wind gusts to 76 mph at Tulsa OK, and heavy rain which caused flooding of Cat Claw Creek in the Abilene TX area. Lightning struck the building housing a fish farm in Scott AR killing 10,000 pounds of fish. Many of the fish died from the heat of the fire.
Good night and God bless!
-DM-
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