SW Louisiana Forecast Discussion...It is a chilly night as we mark the end of Hurricane Season 2009. The cold front moved through right on schedule this morning with a good coverage of shower activity with a few embedded thunderstorms. Brief heavy rainfall occurred across the forecast area, but all in all amounts were limited to the fast moving nature of the front. Generally rainfall amounts were around an inch or less. Rain tapered off to intermittent light rain or drizzle by mid-morning, and some drier air has moved in temporarily tonight as we are in between weather systems. Temperatures fell slowly throughout the day as CAA took over behind the front. Early morning temperatures were in the upper 60s to near 70, and current readings are in the upper 40s to lower 50s across the forecast area. The front which moved through this morning has made good headway, and has cleared the state. It has slowed forward progress, and will be stalling out overnight across the Gulf. At this same time energy embedded in the Subtropical Jet Stream i.e. an upper level low over New Mexico and West Texas, and cyclogenesis off the lower Texas coast along the boundary. The upper level low will bring a significant snow storm to the West Texas Mountains and Permian Basin area. This low will slowly work to the ENE over the next couple of days. The low pressure in the Gulf will move NE along the front at the same time. This will set the stage for a significant rain event for the next couple of days. The forecast area should remain dry overnight, but the moisture will be pooling over the Gulf and the rain shield will be approaching the coast. Overnight temperatures will fall into the mid 40s as CAA continues. Winds will be a factor as well with the presence of a strengthening pressure gradient force in response to Gulf cyclogenesis. NNW winds will be on the order of 15-20 mph and gusty.
It will be a wet start to meteorological winter as rain will overspread the area Tuesday morning, and will get heavier throughout the day as the low moves closer to the coast. It should mostly be a steady rain, and not really a set up for thunderstorms. The surface low should track towards the South Louisiana coast, but this should occur to the East of the forecast area. Model output currently brings the surface low near the SE Louisiana coast before jaunting NE towards the Florida Panhandle. With the projected track of the low, rain will be heavy at times especially Tuesday late afternoon through early Wednesday morning. A few elevated thunderstorms may occur, but with cold air in place at the surface, and the presence of a more stable air mass, no severe weather is expected here. The warm sector will likely move onshore points Eastward, and a severe weather may result across the SE U.S. likely on Wednesday. For us, rain chances will be tempered upward throughout the day as the moisture from the Gulf overspreads the area. The heaviest rainfall will be near the coast, with lighter amounts across the Northern portion of the forecast area. However, rain chances will be high in all sectors of the forecast area. Rain chances will max out Tuesday night as the low makes its closest approach to the area. This is the time frame when the rain will be at its heaviest as well. The front was a fast mover today, and that helped sequester rainfall amounts, however, this time around amounts will be quite a bit higher as the NE progression of the low will be a slow but steady process. It will take until Wednesday morning for the rain to end from West to East across the forecast area. All the while, it will remain on the cold side with continued CAA due to the placement of the low. Temperatures will struggle to reach 50 on Tuesday, so it will be quite raw. Expect wind chill readings in the 35-40 degree range for much of the day with stiff NE breezes up to 20 mph at times. Rain should begin by mid-morning along and South of I-10, and by noon for the remainder of the forecast area. It will continue through the overnight hours. The rain will finally come to an end Wednesday...more on that in a moment! I expect total rainfall amounts to be on the order of 1-3" for this event, with some amounts of 4-5" possible mainly across the extreme SE portion of the forecast area. Where heavier rain occurs, some localized flooding will be possible, but a widespread flooding event is not anticipated. A coastal flood threat is also prevalent as strong winds aid in piling water up along the coast, however, this should not be a major situation at this time.
The ending of the rain will be a gradual process, and it will end from West to East Wednesday. The widespread rain should end before noon Wednesday with just some off and on light rain after that for a few hours into Wednesday afternoon. As the low departs, drier air will move in at all levels. CAA will continue on Wednesday, and it will remain quite raw with gusty winds. After morning lows in the lower to middle 40s afternoon highs will only be in the upper 40s to lower 50s. Clouds should remain in place throughout the day Wednesday even though the rain comes to an end. Skies clear up overnight Wednesday as high pressure builds in from Texas. This will be quite a strong high pressure, and will bring us the coldest weather so far this season. Lows by Thursday morning should be in the mid to upper 30s for much of the area under clear skies. Thursday should be a nice day, but on the cool side. This first high will quickly be re-enforced by a surge of Arctic air. The front will likely come through dry with only an increase in wind noted. Highs will struggle to reach the 50s with the secondary surge of cold air arriving, so it will continue to feel winterlike. Thursday night will be the coldest night of the season so far as the modified Arctic air filters into the region. I expect freezing temperatures for the Northern half of the area, while the remainder of the area will be in the frosty category with temperatures in the 35-40 range under clear skies. The coldest locations of the forecast area could be as cold as the upper 20s by Friday morning. It will be necessary to protect the plants and pets by this time.
On Friday, it will be cold!!! That is the easy part of the forecast. How cold remains to be seen, but the Arctic air mass will continue filtering into the region. There are model differences in handling a disturbance embedded in the established NW flow. Some models hint at a bit of a Gulf low developing along with an embedded short wave in the established long wave trough pattern over the contiguous 48 states. This is a pattern that often brings cold Arctic air to the Gulf coast. Other models suggest just clear and cold. It is very complex situation. If more models come into agreement in the days ahead, then I'll have to add a chance for some precipitation for Friday. I will forecast some cloud cover at this time, but maintain a dry forecast for Friday. Temperatures will struggle to reach the 50 degree mark with the cold air filtering in, and the possible clouds to hide the cold December sun. Wind chills will be in the 20s area wide for much of the day, and actual temperatures will be well below normal for early December. Friday night/Saturday morning will continue to be cold with the coldest temperatures since last winter expected. A freeze is expected area wide with mid to upper 20s expected with the exception of coastal areas where lower 30s should reside. A hard freeze could occur across the Northern portion of the forecast area...stay tuned!!! The 1040 mb. high should settle over Texas, causing a relaxation of the winds, and a ceasing of CAA. For Saturday, it should be a beautiful day with a few high clouds since the Subtropical Jet could be active. A modest warm up will occur with temperatures reaching the mid 40s. The Arctic air will be slow to retreat, so expect the cold weather to continue for the weekend. Saturday night should be another clear and cold night with temperatures down near the freezing mark again.
A return flow is established for Sunday with a more modest warm up expected with highs reaching the 50s. Clouds will increase as another front in the everlasting parade of systems develops in the lee of the Rockies. It should remain dry. The next chance of rain enters the forecast on day 7...Monday. Return flow showers could develop as the next digging trough intensifies, and turns Eastward over the Red River Valley. It will be warmer, but not much. It will likely not be as warm as some models indicate especially if Arctic air is entrenched across the area late this week, as the models simply have a hard time with Arctic air masses. I'll keep temperatures below normal for the end of the forecast period with lows in the 40s and highs around 60. The best chance of rain after mid-week looks to come just beyond the forecast period as another strong front moves through, possibly bringing in more Arctic air mid-next week. The overall pattern for December looks to be one that will be wetter and cooler than average, and should not be a boring month by any means.
Tropics: This is the last time to update the tropics for another year. The tropics are quiet as we close out the season. I'll have a season recap in the coming days, but with the impinging storm, I will defer that until later this week or over the weekend. The tropics section of the blog will be discontinued after tonight until June 1, 2010. It will be replaced with this date in weather history beginning tomorrow!
Preliminary Numbers & Zone Forecast:
LCH 45/50 43/48 34/51 30 80 100 60 0 0
LFT 44/51 42/48 35/50 30 80 100 70 0 0
BPT 46/50 43/49 35/52 30 90 90 60 0 0
AEX 42/46 40/44 31/48 20 80 80 60 0 0
POE 43/47 41/45 32/49 20 80 80 50 0 0
ARA 47/52 44/50 36/52 30 80 100 70 0 0
Tonight...Cloudy, Cool, and Windy with a 30% chance of rain mainly after midnight. Low 45. NNW wind 15-20 mph and gusty.
Tuesday...Cloudy, Windy, and Cold with Rain becoming likely by mid-morning. Heavy at times. A few thunderstorms possible in the afternoon. High 50. NNE 15-20 mph and gusty. Chance of rain 80%.
Tuesday Night...Cloudy, Windy, and Cool with ran and a few thunderstorms likely. Rain heavy at times. Low 43. NNE wind 20-25 mph and gusty. Chance of rain 100%.
Wednesday...Cloudy, Windy, and Cold with a 60% chance of rain in the morning. Rain ending in the afternoon. High 48. NNE wind 20-25 mph and gusty becoming NNW at 15-20 mph and gusty. Total rainfall amounts from Tuesday morning through Wednesday morning 1-3" with higher totals up to 5" possible.
Wednesday Night...Becoming Mostly Clear and Cold. Low 34. NNW wind 10-15 mph and gusty. Wind chill readings 20-25 by morning.
Thursday...Sunny and Cold. High 51. NNW wind 10-15 mph.
Drew's 7 Day Outlook for Lake Charles & Vicinity
Tuesday
12-1-09
Low: 45
High: 50
Rain: 80%
Wind: NNE 15-25
Wednesday
12-2-09
Low: 43
High: 48
Rain: 60%
Wind: NNE/NNW 15-25
Thursday
12-3-09
Low: 34
High: 51
Rain: 0%
Wind: NNW 10-15
W.C.: 20-30
Friday
12-4-09
Low: 31
High: 41
Rain: 20%
Wind: NNW 10-20
W.C.: 20-25
Saturday
12-5-09
Low: 27
High: 44
Rain: 20%
Wind: NNE 10-15
W.C.: 15-30
Sunday
12-6-09
Low: 32
High: 54
Rain: 0%
Wind: ESE 10
W.C.: 25-35
Monday
12-7-09
Low: 45
High: 61
Rain: 40%
Wind: SE 10-15
...Marine Forecast...
*Small Craft Advisory.*
Tonight...Northeast winds 15 to 20 knots becoming 15 to 25 knots after midnight. Seas 3 to 4 feet building to 3 to 5 feet after midnight. A chance of rain.
Tuesday...Northeast winds 15 to 25 knots. Seas 3 to 4 feet. Showers likely in the morning...then showers in the afternoon.
Tuesday Night...Northeast winds 15 to 25 knots becoming northwest after midnight. Seas 2 to 4 feet. Showers in the evening...then showers likely after midnight.
Wednesday...Northwest winds 15 to 25 knots increasing to 20 to 25 knots in the afternoon. Seas 3 to 5 feet. A chance of rain.
Wednesday Night...Northwest winds 15 to 25 knots becoming north 15 to 20 knots after midnight. Seas 3 to 5 feet subsiding to 2 to 4 feet after midnight.
Thursday...North winds 10 to 15 knots. Seas 1 to 3 feet.
...Tide Data...
Tuesday Tides @ Calcasieu Pass:
Low: 7:18a.m. 8:36p.m.
High: 3:03a.m. 9:59p.m.
...Toledo Bend...
171.65'
...Lake Charles Climate Summary...
Monday, November 30, 2009
Low: 50
Normal Low: 46
Record Low: 20-1911
High: 70
Normal High: 66
Record High: 86-1912
Rainfall:
Today: 0.67"
Month to Date: 2.60"
Normal Month to Date: 4.61"
Year to Date: 64.54"
Normal Year to Date: 52.59"
Record: 3.21"-1968
Sunrise Tuesday: 6:52a.m.
Sunset Tuesday: 5:12p.m.
Tuesday Hunting Times: 6:22a.m.-5:42p.m.
Good night and God bless!
-DM-
No comments:
Post a Comment