*The blog will be in severe weather mode tonight.* Regular format will return tomorrow.*
SW Louisiana Forecast Discussion...The advertised spring storm system is approaching tonight. Showers & storms have erupted, and are scattered about the forecast area. There has been little in the way of severe weather here locally so far, but that should change later on tonight. The warm front has worked its way inland, and is now situated well North of I-10. After a refreshingly cool morning, the warm & muggy air mass is in place. High temperatures were near 80 at LCH, and into the lower 80s in Acadiana which was in the warm sector for a longer period today. Shower activity and scattered convection continues to develop in the warm sector and move slowly NE. At the same time, a disturbance embedded in the Southern branch of the Jet Stream is ejecting NE out ahead of the main trough and attendant cold front. This cold front is translating SE as we speak, and will be the main focal point for showers & thunderstorms in the overnight hours. The pre-frontal perturbation will allow for a weakening of the upper level cap and increasing instability and lifting. This will allow for showers & thunderstorms to become more numerous. As Jet Stream energy gets involved, the potential for severe weather will develop. Showers & thunderstorms will continue to develop out ahead of the main thrust of the system, and as these feed off of the high moisture content and the increasingly unstable air mass, isolated severe cells will be common with damaging winds, large hail, and isolated tornadoes all possible. A Tornado Watch was previously in effect for all of SW Louisiana until 10:00p.m., however, this has just been changed to a Severe Thunderstorm Watch, and the time was extended until 4a.m. Wednesday. The Tornado Watch is still in place over SE Louisiana where the parameters for tornadoes are more prevalent.
It will be advisable to have some way to keep yourself abreast of the latest weather developments. If you have a NOAA Weather Radio, make sure it is in alert mode. Review your severe weather plan of action. There will be the potential for heavy rainfall with 1-2" possible in some areas. Not everyone will see those amounts, but everyone should get in on some much needed rainfall. The biggest threat for severe weather will come between midnight and 6a.m. depending upon where you are in the forecast area. I will narrow it down even more, and say 2-4a.m. for the Lake Charles area. I don't really see much change from my forecast reasoning last night. Hail and damaging winds are still the main threats, but certainly conditions seem favorable for an isolated tornado or two. The combination of the ejecting disturbance and the cold front will work in tandem to produce this severe weather potential. I would expect scattered showers & storms to develop along and just out ahead of the cold front in Texas within the next few hours. This scattered activity will migrate Eastward and congeal into a squall line as the night progresses. It will quickly move into our area in the pre-dawn hours of Wednesday. Rain chances will be in the likely category through Wednesday morning. The threat for severe weather will come to an end as the front makes its way through the area. It will easily push into the coastal waters after daylight. It will remain on the warm side until frontal passage with temperatures holding in the 70s until the early morning hours. We will fall into the lower 60s behind the front as CAA takes over. Winds will shift from onshore to offshore in the wake of the front.
The post-frontal weather will certainly be much calmer, but rain chances will not totally be eliminated from the forecast just yet. Lingering moisture will be present in the post-frontal environment. High pressure will slowly be building in. CAA will be in place, and a small diurnal range is expected with highs only reaching the upper 60s to lower 70s. As the trough advances across the country, an embedded upper level feature on the backside of this cold front will swing through with the trough. This will keep a chance for some shower activity in place through the day. Rain chances will be much less, dropping from near 70-80% early in the day into the 30-40% range in the afternoon. The clouds will hang tough as well. Additional rainfall amounts will be on the light side, and the additional rainfall should generally be in the form of light rain or drizzle. It will feel cooler than the forecasted upper 60s to lower 70s thanks to strong NNW winds up to 20 mph at times. Clearing skies will finally occur overnight Wednesday as the backside disturbance vacates the area, and high pressure builds in. The chance for rain will likely end by midnight, if not sooner. The upper level flow will be much faster for at least the next 24-48 hours, so that may allow for a faster ejection of the system than models indicate. Conditions will be on the cool side heading into Thursday with morning lows as cool as the mid 40s in the coldest locations. Average temperatures will be around 50 across the forecast area, and generally in the middle 50s or so along the coast. Winds will subside during the night as the high pressure moves closer to the area.
Great weather is on tap for the latter half of the week. March will go out like a lamb with high pressure in control. It will be quite comfortable for Thursday with highs reaching the low to mid 70s, plenty of sunshine, and not much humidity. Friday will be just as nice, but a substantial warming trend will begin in the afternoon. The high pressure will begin to slide Eastward, and that will cut off CAA. Friday morning temps will still be on the cool side with similar morning lows. Afternoon highs will trend back to above normal just like that! Hence the term, cool snap, as is so often the case in Spring. It will still be great with readings in the upper 70s and low humidity in place. The weekend ahead looks awesome as well especially Saturday. The air will warm up quickly because of the influences of dry air in place, and by later morning on Saturday the return flow will commence as high pressure slides far enough to our East. Saturday should be the third day in a row of nothing but sunshine. Morning lows will be at or above normal again with readings generally in the mid 50s or so. Afternoon highs around 80 to the lower 80s should be amassed. Humidity levels will begin to rise thanks to the return flow in the afternoon, but it will still be pleasantly warm. Things change on Sunday. Much more humid weather will be in place, and it will be unseasonably warm. The surface high will have moved well to our East, but a big upper ridge will be in place. We will remain dry but Partly Cloudy skies are expected along with a Southerly breeze ushering in deeper Gulf moisture. Temperatures should by far reach the warmest levels we have seen so far in 2011 with morning lows in the 60s while afternoon highs reach the lower to middle 80s for maximums in all locations. Get out there and enjoy this first weekend of April.
Into next week, an active pattern is established. The warming and humidifying trend continues in earnest Monday ahead of our next storm system. All indications are this will be a rather vigorous storm system, and it will be moving into the area later on Monday into Tuesday. Monday will be very warm & windy with a general mix of sun and clouds. Some scattered showers & isolated storms are possible in the afternoon with the effects of daytime heating and increasing moisture ahead of our next storm system. Afternoon highs should easily reach the mid 80s. Showers & thunderstorms should be likely for Monday night into Tuesday as the strong April cold front associated with a deepening Mid West trough makes its way into the area. The pattern has the look of an opportunity for severe weather again, but let's get this short-term system out of here first before we decipher specifics of this next cat. Severe weather or not, it appears as though a sharp cool down will occur on Tuesday. The timing of the front at this juncture depicts a morning passage, and temperatures may struggle to reach the 60s on Tuesday afternoon with strong CAA in place and strong Northerly winds behind the front. It may stay gray and drizzly as well. It will almost have the feel of a winter day the way it stands right now. The late season cold snap will take us into the middle to latter portions of next week. We aren't done with jacket weather just yet. Stay tuned for more!!!
Preliminary Numbers & Zone Forecast:
LCH 58/68 51/72 50/77 70 40 20 0 0 0
CAM 62/71 55/75 52/75 70 40 20 0 0 0
LFT 60/70 52/73 50/76 70 40 20 0 0 0
ARA 62/71 55/75 52/75 70 40 20 0 0 0
BPT 59/69 51/73 51/78 70 30 20 0 0 0
AEX 55/65 47/70 46/73 70 40 20 0 0 0
POE 55/65 47/70 46/73 70 40 20 0 0 0
*Severe Thunderstorm Watch in effect until 4a.m. CDT Wednesday.*
Tonight...Cloudy w/ showers & thunderstorms likely. Some severe thunderstorms possible with large hail, damaging winds, & isolated tornadoes. Locally heavy rainfall with amounts of 1-2" possible. Turning Cooler after midnight. Low 58. SSE wind 10-15 mph becoming NNW at 15-20 mph and gusty. Chance of rain 70%.
Wednesday...Cloudy w/ a chance of showers & thunderstorms in the morning. Rain tapering off during the day w/ a chance for mainly light rain and/or drizzle in the afternoon. High 68. NNW wind 15 mph and gusty. Chance of rain 70% early decreasing to 40% through the day.
Wednesday Night...Cloudy w/ a 20% chance of rain until midnight. Skies clearing after midnight. Much cooler. Low 51. North wind 10 mph.
Thursday...Sunny. High 72. North wind 5-10 mph.
Thursday Night...Clear & Cool. Low 50. Light North wind.
Friday...Sunny. High 77. NE wind 5-10 mph.
Drew's 7 Day Outlook
Wednesday
3-30-11
Low: 58
High: 68
Rain: 70% Early...40% Rest of the Day
Wind: NNW 15-20
Thursday
3-31-11
Low: 51
High: 72
Rain: 0%
Wind: N 5-10
Friday
4-1-11
April Fool's Day
Low: 50
High: 77
Rain: 0%
Wind: NE 5-10
Saturday
4-2-11
Low: 55
High: 80
Rain: 0%
Wind: SE 5-10
Sunday
4-3-11
Low: 65
High: 84
Rain: 0%
Wind: SSE 15
Monday
4-4-11
Low: 67
High: 85
Rain: 30%
Wind: SSE 20-25
Tuesday
4-5-11
Low: 57
High: 64
Rain: 70%
Wind: NNW 20-25
...Marine Forecast...
Tonight...Northeast winds around 10 knots becoming north after midnight. Seas 2 to 4 feet. A chance of showers and thunderstorms.
Wednesday...North winds 15 to 20 knots decreasing to around 10 knots in the afternoon. Seas 2 to 4 feet subsiding to 2 to 3 feet in the afternoon. A chance of showers.
Wednesday Night...Northeast winds 10 to 15 knots. Seas 2 to 3 feet. A slight chance of showers.
Thursday...Northeast winds 10 to 15 knots becoming southeast around 5 knots in the afternoon. Seas 2 to 3 feet subsiding to 1 to 2 feet in the afternoon.
Thursday Night...Southwest winds 5 to 10 knots. Seas 1 to 2 feet.
Friday...Southwest winds around 10 knots. Seas 2 feet.
Good night, have a great Wednesday, & God bless! Stay tuned for more updates should they become necessary tonight!
-DM-
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