I hope everyone had a very blessed and Happy Thanksgiving. Now, as we head into the Christmas season, let us not forget the real reason for the season. It is easy to do that sometimes with all the hustle and bustle and hype of holiday shopping. Remember, that there was no mad rush to the stores to buy presents over 2,000 years ago when we received the greatest gift of all. Jesus is the reason for the season!
The blog will be in severe weather mode through Monday with a possible severe weather outbreak looming for Monday afternoon through Monday night. Only a text form of this blog is available. The video blog will return Tuesday. Be sure to scroll down for the text form of this blog.
SW Louisiana Forecast Discussion...The weather roller coaster rolls on. After wearing shorts through Thanksgiving, we were in heavy coats on Friday with temperatures some 35-40 degrees colder. We experienced our first freeze of the season on Saturday morning, and it was quite chilly this morning as well. A very progressive pattern for late November is in place. Our next storm system is already unfurling tonight. A strong Southerly flow is in place allowing a rich supply of Gulf moisture to return across the area. Clouds have been on the increase throughout, and that's a sure sign of our ever changing weather patterns. It was about as beautiful as it ever gets around here on Saturday after the morning freeze. Temperatures moderated progressively over the weekend, only reaching the upper 50s to lower 60s on Saturday, and extending into the upper 60s Sunday afternoon. Temperatures are much milder tonight with robust warm air advection ongoing. Expect the overnight lows to only be in the mid 50s on average. Temperatures could actually slowly rise overnight as the current WAA regime intensifies. The amounts of low level moisture will increase further, and cloud cover will follow suit as we anxiously await a potent Pacific weather system. As we head back to work and school Monday, it will start off quietly with just Mostly Cloudy skies in place.
Conditions will deteriorate as the day progresses Monday. A negatively tilted, deepening trough and its attendant cold front will be surging SE during the day. There is also the presence of a surface low over the Great Plains. As the sharp cold front approaches, moisture will continue to pool. The advancing front will increase forcing over the forecast area, and a very fast Jet Stream overhead will instigate strong dynamics across this forecast area. A few scattered showers and/or thunderstorms will be possible during the morning hours as warm air advection continues, and some air mass type activity develops. Rain chances leap into the likely category for the afternoon into the overnight hours. Convergence will continue increase, and this will initiate showers and thunderstorms over the area in the pre-frontal environment. Along and just ahead of the actual cold front, a line of storms will develop (MCS) over the Red River Valley in the morning hours, and translate SE through the day. Many of the necessary parameters required for severe weather will be in place in the pre-frontal environment. The strong Jet Stream will create a large amount of atmospheric wind shear. Strong CAPE (Convective Available Potential Energy) values will also co-exist with the main Jet dynamics. The wind shear will result in a tornado threat across much of the state. There is virtually no skill in pinpointing exactly where a tornado will occur. I urge everyone to stay abreast of the weather conditions throughout the day Monday. There is a high amount of energy that will need to be displaced, so a severe weather threat could certainly be realized. It will temporarily be warm on Monday with highs reaching back into the mid 70s, this is back into the above normal category. The strong onshore flow will persist, and this will create rough conditions on area waterways. Thus, a Lake Wind Advisory is in effect for Monday.
The other modes of severe weather will be possible, and damaging winds seem like the most likely aspect of the three to occur. The strong Jet Stream winds aloft will translate down to the surface with the thunderstorms. Winds are related to height, meaning that they will decrease with height as they move towards the surface. The downbursts created by each thunderstorm will translate these strong winds down to the surface. Winds up to 100 mph are possible in the strongest storms especially if any tornadoes occur. I would fully expect some sort of Tornado or Severe Thunderstorm Watch to be hoisted for the forecast area at some point Monday afternoon as the system hurls its way towards us. The severe weather threat covers the entire area, but the greatest threat should be just off to our NE, running from around Alexandria to Monroe and over into SE Louisiana. Large hail can't be ruled out either with plenty of cold air aloft. Heavy rainfall will be a fixture as well, and a more significant rain event than occurred with the previous system. 1-2" on average is expected across the area between Monday afternoon and Tuesday morning. The window of opportunity for severe weather will likely be from around 4p.m. Monday until about 4a.m. Tuesday. I believe that severe weather will be realized given the sufficient dynamics in place. There was very little in the way of dynamics in place back on Thanksgiving night, and some tornadoes occurred from near Jennings up towards Opelousas from low topped showers. The sharp cold front will slide through the forecast area overnight Monday, as the surface low ejects NE into the Mid West region. The severe weather threat will come to an end with frontal passage from West to East by early Tuesday morning. Much colder air will filter into the region in the post-frontal environment. Rain chances will continue for a short duration with a brief period of overrunning as CAA intensifies. Stable air in place at the surface will be overridden by a shallow layer of warm air around 5,000' in the atmosphere. This will keep the boundary layer saturated, and allow for a transition from showers and thunderstorms (cumuliform), and the severe threat to generally light post-frontal stratiform rain. Temperatures will change drastically heading into Tuesday with readings dropping into the upper 40s to lower 50s across the area. A strong offshore flow will take over in the wake of the front.
Conditions improve as the day wears on Tuesday. The short period of overrunning will come to an end during the morning as the boundary layer moisture decreases. The advancing cold front will continue to make headway into the Gulf of Mexico, and high pressure from the Rockies builds towards the NW Gulf Coast. Rain comes to an end from West to East across the area, ending in the pre-dawn hours across SE Texas and by midday across Lower Acadiana. Skies will remain Mostly Cloudy for a while longer as the transition from low pressure to high pressure commences. Strong CAA will continue for Tuesday, and high temperatures will be below normal again. A very small diurnal range is forecast as CAA offsets daytime heating. Daytime highs will be in the mid 50s at best. The sun should make an appearance later in the day as all clouds push out of the area. Remember how cold it was on Saturday morning? A very similar set up is in the offing by mid-week as the strong high pressure system ridges in. The clear skies and decaying winds will set the stage for a night of radiative cooling. Another light freeze is likely across much of the area heading into Wednesday morning. Minimums will range from the upper 20s to lower 30s for most, with mid to upper 30s along the immediate coast. It will be time to protect the tender vegetation once again.
High pressure dominates the weather for the remainder of the forecast. It will be a cool start to meteorological winter on Wednesday with highs only reaching the mid to upper 50s as the offshore flow maintains itself. It will be similarly cold for Wednesday night into Thursday as the strong controlling Canadian high pressure moves right over head. Temperatures will range from the upper 20s to lower 30s again, and another light freeze is expected down to the I-10 corridor. Air mass modification begins Thursday with highs exceeding the 60 degree threshold. The high pressure will only slowly shift Eastward through the weekend, and a slow air mass modification is expected. Beautiful weather will round out the work week as the high dominates. Friday morning will be on the cool side with lows generally close to 40. Afternoon highs will be close to normal for early December. An onshore flow returns Saturday, and models have been wavering on the idea of another cold front making its way through the area on Saturday. This is not currently reflected due to the uncertainties. However, it looks as though significant moisture return will be slow as the strong blocking high will be located over the SE U.S. Air mass modification will suggest a normal temperature regime for Saturday. The December warming trend continues for Sunday with a more pronounced warming trend ensuing. Another storm will be in the formative stages at this time. At this time, it should remain dry with the lack of a trigger mechanism and a largely capped atmosphere. Seasonable weather is expected. It looks like the first weekend of December will be a nice one, if you have plans to put out your Christmas lights et al. Another decently potent system is looming just beyond this forecast period in the December 6th-8th time frame. This is certainly not the time to be specific about that system. Stay tuned for the latest weather information throughout the day Monday.
Preliminary Numbers & Zone Forecast:
LCH 54/77 50/55 31/58 10 70 80 20 0 0
LFT 53/77 51/56 31/57 10 70 80 20 0 0
BPT 56/78 52/57 32/59 10 70 80 20 0 0
AEX 50/75 48/53 27/58 10 70 70 20 0 0
POE 50/75 48/53 28/58 10 70 70 20 0 0
ARA 56/76 52/56 32/58 10 70 80 20 0 0
Tonight...Mostly Cloudy with an isolated shower possible towards morning. Low 54. SSE wind 10-15 mph.
Monday...Mostly Cloudy with showers & thunderstorms likely in the afternoon. Some severe weather with damaging winds and isolated tornadoes possible. High 77. SSE wind 15-25 mph and gusty. Chance of rain 70%.
Monday Night...Cloudy with showers & thunderstorms likely. Some severe weather possible along with the threat for locally heavy rainfall. Turning Cooler & Windy after midnight. Low 50. SSW wind 15-25 mph and gusty, becoming NNW at 15-25 mph by midnight. Chance of rain 80%.
Tuesday...Mostly Cloudy with a 20% chance of showers & thunderstorms in the morning. Rains tapering off from west to east during the morning. Skies slowing clearing through the day. Much colder. High 55. NNW wind 15-20 mph and gusty.
Tuesday Night...Clear and Cold with a Light Freeze. Low 31. North wind 5-10 mph.
Wednesday...Sunny. High 58. North wind 5-10 mph.
Monday 11/29/10 Daily Planner
6a.m.
Weather: Mostly Cloudy
Temp: 55
Rain: 10%
Wind: SSE 8
9a.m.
Weather: Mostly Cloudy
Temp: 63
Rain: 20%
Wind: SSE 11
Noon
Weather: Mostly Cloudy...Showers/Storms Beginning to Develop
Temp: 70
Rain: 40%
Wind: SSE 16
3p.m.
Weather: Cloudy w/ Scattered Storms
Temp: 75
Rain: 60%
Wind: SSE 21
6p.m.
Weather: Rain & T-Storms Likely
Temp: 70
Rain: 70%
Wind: SSE 22
9p.m.
Weather: T-Storms Likely...Some Severe
Temp: 66
Rain: 80%
Wind: SSW 18
Drew's 7 Day Outlook
Monday
11-29-10
Low: 54
High: 75
Rain: 70%
Wind: SSE 15-25
Tuesday
11-30-10
Low: 50
High: 55
Rain: 80% Before Daybreak...20% AM
Wind: NNW 15-25
Wednesday
12-1-10
Low: 31
High: 58
Rain: 0%
Wind: N 5-10
W.C.: 25-35
Thursday
12-2-10
Low: 33
High: 62
Rain: 0%
Wind: N 5
Friday
12-3-10
Low: 38
High: 64
Rain: 0%
Wind: NE 5-10
Saturday
12-4-10
Low: 43
High: 68
Rain: 0%
Wind: E 5-10
Sunday
12-5-10
Low: 47
High: 68
Rain: 0%
Wind: SSE 5-10
...Tropical Update...
The tropics are quiet, and will stay that way as we round out the 2010 season coming up on Tuesday.
...Marine Forecast...
Tonight...Southeast winds 15 to 20 knots. Seas 3 to 4 feet. A slight chance of showers.
Monday...South winds 15 to 20 knots. Seas 3 to 4 feet. A slight chance of showers and thunderstorms in the morning...then numerous showers and thunderstorms in the afternoon.
Monday Night...Southwest winds 15 to 20 knots shifting northwest 20 to 25 knots after midnight. Seas 3 to 4 feet. Numerous showers and thunderstorms in the evening...then a chance of rain after midnight.
Tuesday...North winds 25 to 30 knots. Seas 2 to 3 feet. A chance of rain in the morning.
Tuesday Night...North winds 20 to 25 knots. Seas 2 to 3 feet.
Wednesday...Northeast winds 15 to 20 knots decreasing to 5 to 10 knots in the afternoon. Seas 2 to 3 feet.
Have a great Monday & God bless!
-DM-
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