I hope everyone had a very merry and blessed Christmas. The blog returns on this Monday after Christmas. I will keep it in holiday mode through New Years weekend. That means, there will not be a video blog, and some sections of the text block will be omitted. Also, there is a possibility of severe weather later this week (Wednesday & again late Friday night into Saturday (New Years)). Should a severe threat materialize then there will be more frequent blog updates. Stay tuned for more on this developing situation.
Sometime over the course of this week or early next week depending on if the weather cooperates, I will post the top 10 weather events of 2010 on a local and national level. I will keep you updated as to when this will be posted. Thanks to all who view this blog, and please help keep spreading the word. I am the weather authority in SW Louisiana, leave no doubt about that. You need not look to anyone else for your weather information, and that will remain the case in 2011. I wish everyone all the best in the coming year, and once again I hope you had a very nice Christmas. Happy New Year! See the forecast below.
SW Louisiana Forecast Discussion...The cold weather is gone at least for the rest of 2010. In what has been one of the driest years and Decembers on record, the fact that it appears that both the month and the year will end on wet notes seems a little ironic. However, that is exactly what we have to look forward to over the final 3 days of 2010. Specifics are forthcoming. First, here in the short-term, a quiet weather regime will remain locked in place tonight. WAA is ongoing as Southerly winds now encompass the entire area. Air mass modification has taken over in earnest. There will no threat of freezing temperatures anywhere in the area tonight. After a day which featured an increase in clouds and low level moisture, the same will hold true tonight. Overnight lows will generally be around seasonal levels with readings in the 40s. Some patchy fog can't be ruled out after midnight with the presence of the return flow over the area. Generally overcast skies will be expected tonight. Our next rain maker, and our most significant rain event of this month moves in on Wednesday.
A combination of factors will lead to this much needed rainfall across the entire area. A warm front that developed over the Gulf of Mexico and an embedded short wave (disturbance) will be ejecting Eastward across Texas, and affecting this forecast area Wednesday. These systems will work in tandem to produce widespread rainfall across the area. Showers and thunderstorms will develop during the morning hours on Wednesday, and move into the forecast area as the day progresses. Rainfall will increase in coverage and intensity as the advecting short wave taps into the available Gulf energy. The warm front and attendant weak surface low will push NE into and through the forecast area. Rain will be widespread and total rainfall amounts will likely be around an inch or so with the possibility of two inches in some locales. Severe weather doesn't appear to be a likely entity at this juncture, however, there will be the presence of enough instability and low-level wind shear especially along and South of the I-10 corridor Wednesday afternoon into Wednesday night such that some isolated severe storms may occur. The main threats will be damaging winds and isolated tornadoes. A word to the wise would be to keep a watchful eye to the sky, and to check back here for further updates throughout the day Wednesday. It is also a good idea to set your NOAA Weather Radio to alert mode. Moisture will build across the area in advance of the system, so with the ample low level moisture in place and plenty of dynamics and lifting in place expect the favorable set up for the widespread rain event. Shower activity will be scattered initially during the morning hours, and quickly ramp up into the likely category after lunch. The window of opportunity for the aforementioned severe weather will be a small one. I have narrowed this time frame down to between about 4p.m. and 10p.m. as the main thrust of this weather maker affects the region at this time. Rain chances will nearly max out for Wednesday, and a much milder temperature regime is on tap. Expect highs to approach 70 with the widespread convective activity. The ongoing Southerly flow will prevail, and only become more pronounced as the day wears on.
The high end rain chances continue into Wednesday night before tapering off overnight. The embedded disturbance will ultimately lift out to our NE along with the weak surface low and warm front. This will bring in a more stable air mass and a dry slot across the region. We will remain in a WAA pattern in the wake of the previously mentioned synoptic features, but the timing of the system should eliminate any adverse weather conditions for the late night/early morning hours when severe weather is often the most dangerous (because most people are sleeping). I certainly can't eliminate the chances for showers and thunderstorms all together after midnight, but the widespread rain event should have ended heading into Thursday morning. Rain chances will be in the 60-70% range before midnight dropping to about 30-40% after midnight. Overcast skies will prevail, and some fog may develop after the rain comes to an end. Mild weather is in the offing with low temperatures returning to above normal levels in the upper 50s to lower 60s for all. We will be between weather systems on Thursday. It will not exactly be a nice day, however. Don't expect any kind of clearing behind Wednesday's weather maker. A forecast of more clouds than sun will be depicted for Thursday with a deep tropical flow from the Gulf of Mexico continuing to reside over the state. The high octane low-level moisture in place and the effects of daytime heating will keep the chance for some scattered convection in the forecast. Widespread rainfall is not expected for Thursday with drier air in the boundary layer and a lack of instability or any kind of lifting mechanism. It will be a day to don short sleeves with high temperatures reaching the uncharacteristically warm 70s across the board. It will be a bit on the breezy side as well as the next storm system gets its act together downstream, and previous system keeps moving further away. The pressure differences will try to equalize right over the area, thus the reason for the expectant windy conditions.
By Thursday night we will turn our attention to our next strong cold front. It will be in transit by this period. It will be a front that has origins in Canada. Deeper moisture will continue to overspread the area on Thursday night. This will keep the chance for some scattered activity in place. The late December mildness will continue with low temperatures not falling below the 60 degree mark. This means the minimum values will be closer to what the maximum values should be at the end of the year. Friday is, of course, New Year's Eve. Many people will undoubtedly have plans to ring in the new year. The big question is will Mother Nature cooperate. At this time this is still an iffy proposition as far as being able to go about your outdoor plans and not have to worry about some of Mother Nature's fireworks. Rain chances will quickly edge up into the likely category once again as we head into Friday afternoon. Moisture will pool over the area in the pre-frontal environs. Jet Stream dynamics will move right overhead, and this will place Louisiana in the favorable right-front quadrant. The RFQ is typically one of the most favorable areas for severe weather to occur. Certainly, a widespread rain event will occur once again. Additional Jet Stream energy may also initiate surface cyclogenesis at the base of the cold front. Convergence will rapidly increase Friday afternoon, thus rain and some thunderstorms will congregate about the forecast area. The year ends on an unseasonably warm note with highs reaching the mid 70s. I wouldn't rule out some upper 70s if there is a bit more sunshine than expected.
As we head into Friday night and New Years Eve itself, here comes the front! Instability will increase, and many of the parameters necessary to produce severe weather may come together. The threat for severe weather during this time frame looks a bit more likely than the first episode does on Wednesday afternoon and evening. All modes of severe weather will be possible, though I surmise that damaging winds will be the biggest threat. I expect a squall line or MCS to develop along the cold front over Texas, and then intensify as it moves Eastward into Louisiana overnight. Certainly, scattered activity will develop over the Gulf and stream inland and intensify out ahead of the main line. This streamer activity will feed into the already very dynamic system. There is still tons of speculation as to the exact timing of the cold front. Most model runs suggest it will cross in the overnight hours between midnight and 6a.m. Saturday, but each run is either a bit slower or faster with the cold front. It will be another day or two before I can clarify with more specificity a smaller time frame for frontal passage to occur. I can't guarantee anyone that your own personal fireworks display will be able to occur given the prospects of rain. Showers and thunderstorms will be likely beginning Friday afternoon and continuing into the very early hours of the new year on Saturday. The severe weather threat will likely begin before sunset Friday and continue at least until around midnight if not a bit later. The greatest forcing and instability will come right along the front itself. In addition to the prospects of severe weather, heavy rain is also in the mix. Another significant rain event on the order of 1-2" is expected during this time. We will certainly get the opportunity to add to our monthly rainfall totals. This may very well keep us from enduring the driest December on record around here. We are 23" behind in rainfall for 2010, so this will definitely go down as one of the driest years ever in South Louisiana, but we should at least have a chance to chip into the deficit just a bit. I will take another gander at all of this tomorrow, so check back for further revisions.
Once the front flies by early on New Years Day, the severe weather threat ends and much cooler air filters into the region. Conditions will improve beyond this point. However, rain chances will carry into the daylight hours on Saturday. A cooler, stable air mass will be filtering into the region at the surface thanks to CAA in the wake of said frontal boundary. However, boundary layer moisture will remain in place for awhile longer as the drier and cooler air in the mid and upper levels lags behind. Expect cloudy skies to continue. Morning temperatures will certainly be cooler than that of Friday. Most readings to start our New Years Day and 2011 will be in the mid 40s to around 50 depending upon your proximity to the cold front. The cold air will be deeper the further inland you go, and more shallow the closer you get to the coast. Rain chances will drop out of the likely category in the pre-dawn hours on Saturday, and fall into the chance category (30-40%) for the remainder of the morning. This brief period of overrunning comes to an end during the day Saturday, and conditions will improve further once the dry and colder air arrives in the mid and upper levels. Skies will slowly clear as the day progresses. It will feel much better outside as well. CAA will negate daytime heating for the most part as high temperatures only reach the low to mid 50s at best across the area. It will quite breezy as well with strong Northerly winds in place behind the front, so it will feel like it's in the 40s all day. That may not be of concern to you at all, though, since many of us will be inside watching football all day for New Year's Day. (count me in on that deal)
After an active stretch of weather these next 4 days, it will be a lot calmer for the rest of New Years weekend. Clear skies and cool temperatures are expected into Monday as high pressure orients itself across the NW Gulf Coastal Plain. CAA will continue in earnest on New Years Night. It should be a seasonably cold night across the area with temps dropping to near freezing from about Hwy. 190 northward with mid to upper 30s south of there. The winds will only slowly decouple as high pressure builds in. Sunday should be a nice but cool day. Plenty of sunshine is expected, but high temperatures won't make it out of the 50s with the modified Canadian air mass in place. The coldest morning this go around looks to be on Monday when everyone is heading back to work and school after the Christmas/New Years holiday break. The high pressure should be situated very close to our area allowing for calm winds and clear skies. This will set the stage for a radiative cooling night on Sunday night into Monday morning. A light freeze is possible for much of the area with some upper 20s for Cenla. It will be very close to freezing, give or take a degree, here in the Lake Area. This air mass is not nearly as cold as the one we are coming out of tonight. Monday should be a fairly nice day with dry weather continuing with the effects of high pressure in control. However, we will be watching the old front over the Gulf. This front looks to stall out somewhere in the coastal waters likely on Sunday. The progressive pattern over the contiguous 48 states may help to re-activate this front, and send it in the opposite by Tuesday. This may induce WAA over the forecast area, and enhance air mass modification. A noticeable increase in clouds is expected, and some forecast models conjure up a prolonged period of overrunning for the first part of next week. I am not ready to get wrapped up into this just yet, but I will reflect an increase in clouds by Tuesday along with the beginnings of our next warm up. All of this will be re-assessed on tomorrow's forecast package. The key things to focus on at this point in time are the significant rain events between now and New Years, and the prospects of severe weather Wednesday evening and Friday night.
Preliminary Numbers & Zone Forecast:
LCH 45/67 59/73 62/74 10 80 80 30 30 70
BPT 48/69 61/74 63/76 20 80 80 30 30 70
AEX 41/63 52/71 59/73 10 80 80 20 30 70
POE 41/63 52/71 59/73 10 80 80 20 30 70
ARA 44/66 60/73 63/74 10 70 80 30 30 70
Tonight...Partly to Mostly Cloudy & Not as Cold. Low 45. SE wind 5-10 mph.
Wednesday...Cloudy w/ showers & thunderstorms likely by afternoon. Isolated severe storms possible late in the day. High 67. SSE wind 10-15 mph. Chance of rain 80%.
Wednesday Night...Cloudy w showers & thunderstorms likely. Locally heavy rainfall & isolated severe storms possible. Rains tapering off after midnight. Much warmer. Low 59. SSE wind 15 mph and gusty. Chance of rain 80%.
Thursday...Mostly Cloudy & Unseasonably Warm w/a 30% chance of showers & thunderstorms. High 73. SSE wind 15-20 mph and gusty.
Thursday Night...Mostly Cloudy & Unseasonably Warm w/ a 30% chance of showers & thunderstorms especially after midnight. Low 62. SSE wind 15-20 mph and gusty.
New Year's Eve...Mostly Cloudy & Windy w/ showers & thunderstorms likely. Severe weather & locally heavy rainfall possible especially in the afternoon. High 74. SSE wind 20-25 mph and gusty. Chance of rain 70%.
Wednesday 12/29/10 Daily Planner
6a.m.
Weather: Mostly Cloudy
Temp: 45
Rain: 10%
Wind: SE 8
9a.m.
Weather: Mostly Cloudy
Temp: 53
Rain: 20%
Wind: SSE 12
Noon
Weather: Mostly Cloudy w/ Rain Developing
Temp: 62
Rain: 40%
Wind: SSE 13
3p.m.
Weather: Rain & T-Storms Likely
Temp: 67
Rain: 60%
Wind: SSE 15
6p.m.
Weather: T-Storms Likely. Isolated Severe Weather Possible.
Rain: 70%
Wind: SSE 15
9p.m.
Weather: Rain & T-Storms
Temp: 62
Rain: 60%
Wind: SSE 13
Drew's 7 Day Outlook
Wednesday
12-29-10
Low: 45
High: 67
Rain: 80%
Wind: SSE 10-15
Thursday
12-30-10
Low: 59
High: 73
Rain: 30%
Wind: SSE 15-20
Friday
12-31-10
New Year's Eve
Low: 62
High: 74
Rain: 70%
Wind: SSE 20-25
Saturday
New Year's Day
Low: 48
High: 55
Rain: 30%
Wind: NNW 15-25
W.C.: 40s
Sunday
1-2-11
Low: 36
High: 54
Rain: 0%
Wind: NNW 10-15
W.C.: 30-45
Monday
1-3-11
Low: 32
High: 53
Rain: 0%
Wind: N 5-10
W.C.: 25-40
Tuesday
1-4-11
Low: 38
High: 60
Rain: 10%
Wind: E 10
W.C.: 30-40
...Marine Forecast...
Rough conditions are developing offshore in advance of our next storm system. A warm front and upper level disturbance will work in tandem to produce a period of storminess across the area on Wednesday. This storm will agitate the coastal waters thus leading to less than ideal conditions for offshore activities. Look for the active period of marine weather to continue into the weekend as another cold front moves into the coastal waters on New Years Day.
*Small Craft Advisory in effect through Wednesday afternoon.*
Tonight...Southeast 20 knots. Seas 3 to 5 feet. A slight chance of showers.
Wednesday...South winds 20 to 25 knots. Seas 4 to 5 feet. Showers and isolated thunderstorms.
Wednesday Night...Southwest winds 20 to 25 knots. Seas 3 to 5 feet. Showers likely and isolated thunderstorms.
Thursday...South winds around 15 knots. Seas 3 to 4 feet.
Thursday Night...South winds 15 to 20 knots. Seas 3 to 4 feet. A slight chance of showers.
Friday...South winds 15 to 20 knots. Seas 3 to 4 feet. A chance of showers and thunderstorms.
Good night & God bless!
-DM-
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