Sunday, January 30, 2011

Very Active Weather Week...Severe Weather Threat & Big Time Arctic Air...

Sunday, January 30, 2011

Click below for the latest edition of the video blog. Be sure to scroll down for the full length text block.




...Major Storm to Impact the Area with the Potential for Severe Weather Tuesday Ahead of a Major Arctic Outbreak...

SW Louisiana Forecast Discussion...The first of two major weather makers has left us with a dreary, rain-soaked Sunday. It has been a great day to stay inside and catch a late afternoon nap or just watch TV. The culprit for today's widespread rain event has been a vigorous cut off low pressure system embedded in the Southern branch of the Jet Stream. The presence of an onshore flow aided in added moisture content to the atmosphere providing the necessary moisture for this rain event to occur. The cold air in the upper levels generated by the ULL itself created instability. Rainfall has been heavy at times thanks to dynamic forcing across the forecast area. Rainfall began in the early morning hours, and will slowly taper off this evening and tonight. Certainly, rain chances will not drop to 0, but they will come down from 100% that was in place most of the day. Some pockets of heavy showers and embedded thunderstorms will persist through the evening hours as this latest perturbation in the mean flow slowly evacuates Eastward. The only upside to this Sunday has been on the temperature side of things. It has been mild in a relative sense with readings reaching the mid 60s. This is just above seasonal norms. Average rainfall totals will be in the 1-2" range before all is over with tonight. At the same, a strong cold front is draped from SW to NE to our North. This front will essentially put on the breaks overnight, so don't expect any cooling behind the first system. Overnight, rain chances will be retained, but only some light scattered activity is expected as the main impulse vacates. The atmospheric profile will support fog development tonight with all the remaining moisture in place. Very light surface winds will be in place as well. Skies will generally remain Mostly Cloudy. Temperatures will not drop off much, and for the Monday morning commute you can expect readings generally in the upper 40s to lower 50s across the area.

Monday will essentially be the calm before (and after) the storm. It won't necessarily be a pretty day though, however. Lots of low-level moisture will be present. The morning fog threat will end by mid-morning, but the present low level stratus deck will persist. The next major storm will be hot on the heels of its predecessor, such that the cloudiness in advance of it will envelop the region Monday, to preclude much in the way of sunshine. A slight chance of showers is maintained for Monday given the residual moisture in place, and moisture advancing ahead of the more potent storm. All activity will be scattered in nature with no instability and only minimal lifting in place. The mild temperature regime will continue with highs reaching the mid to upper 60s across the area. This will be last mild day for awhile. January will close out feeling more like late February or early March. Winds will begin to increase as well in advance of the next system as its advance creates the usual pressure anomalies that exist in this pattern. Rain chances increase yet again Monday night as the next system comes down the pipe. This system originated over the Pacific, and is embedded in the Polar Jet. It has been sliding SE over the weekend, and will be on our doorstep by Monday night. Lifting will be enhanced, and the shear potency of this system will allow for a massive increase in shear. Overnight lows will be on the mild side once again with readings generally in the upper 50s or so.

Now, here's Tuesday, allow me to be rather elaborate here. Rain is a given! I will easily max out rain chances through the day as copious amounts of moisture will be in place, and be wrung out like a proverbial sponge. The vigorous cold core system translating SE in the Polar Jet will come across the Rockies Monday night, and increase energy in the Jet Stream. This will induce cyclogenesis along the current front in Texas. This surface low will translate NE along the boundary and keep a deep flow of Gulf moist air pumping in over the area. The synoptic set up will result in a continued increase in shear, and increasing instability. Lifting reaches a maximum. The stalled front will be replaced by a very strong Arctic front already in transit from the Canadian Prairie region. Moisture will be dispersed out of the boundary, and a widespread rain event will unfold. Showers are likely along with a threat for thunderstorms. The chance of thunderstorms will be greatest along and just ahead of the front when instability peaks. Conditions will be favorable for a late winter severe weather outbreak. The greatest threat will be from large hail and damaging winds, but also an isolated tornado threat will exist. This being winter time, the better threat will be for severe low-topped thunderstorms producing gusty winds and hail. There is a large amount of cold air aloft that will be generated by this system. The cold air aloft will be transported downward with any thunderstorms, thus generating the hail threat. The cold air aloft and warm air at the surface will generate different wind directions, thus creating atmospheric shear in the pre-frontal environ. That will set the stage for the isolated tornado threat. The pressure anomalies in between systems, and the fact there will be such a large amount of energy that needs to be displaced will create gusty onshore winds. The Storm Prediction Center has all of the forecast area highlighted for a slight risk of severe weather day 3. The graphical representation follows. Further assessment will be forthcoming. A heavy rain threat is likely once again. This time, rainfall amounts will be in the 2-3" range. Some localized flooding will be possible given that this will be falling on top of Sunday's rain. A major flooding threat is not expected since we are still in drought conditions overall. The best chance for any severe weather along with the heavy rain threat will come from about mid-morning to mid-afternoon ahead of the front.


















The front will quickly head SE through the forecast area on Tuesday afternoon, and we will quickly return to the harsh reality of winter. Temperatures ahead of the front will be in the 65-70 range. However, temperatures will begin to fall dramatically in the wake of the front. A strong offshore flow will develop at the same time to usher in the coldest air of the season. Temperatures will quickly fall into the 40s by sunset Tuesday. The rain will begin to taper off, but a period of post-frontal rains will exist. The big story will be the transition from the late winter severe weather threat to the coldest air of the season, perhaps the coldest air in years. We will be reminded that yes, it is still winter in February! A large high pressure coming out of Canada will begin to build in by Tuesday night in the wake of the system. The Arctic air will be shallow in nature at least initially, so cloud cover should hang tough heading into Wednesday. This will not impact temperatures for the Tuesday night-Wednesday time frame. Strong CAA continues and transports an icy chill into SW Louisiana. The evening temperatures in the 40s will continue to plummet, and we will drop below freezing on our way into the mid to upper 20s by sunrise Wednesday. Adding insult to injury will be the continued gusty winds over 20 mph at times. This will create dangerous, bitterly cold wind chills with readings in the 5-15 degree range. Skies will generally be Mostly Cloudy, but some breaks in the clouds will be possible. No additional precipitation will be expected in the wake of the front. Wednesday will just be a very cold, dry, and windy day. CAA will continue through the day, and we will generally see more clouds than sun. The CAA will offset the effects of daytime heating. A very cold Groundhog Day is in store. High temperatures will only top out in the mid to upper 30s Wednesday afternoon. Wind chills will remain in the 10s and 20s even in the afternoon....brrrr! Cold weather is in store for the remainder of this forecast, but there are some other interesting factors to discuss.

The Arctic air mass will be firmly entrenched across the area as we begin the latter half of the week. The forecast uncertainty increases beginning Thursday. Models are starting to align with more consistency now, that we won't completely clear out after Wednesday. If we clear out, then the coldest morning lows we've experienced in many years will be realized, these readings would more than likely be in the mid 10s or so. That would easily be record lows for early February. However, it is more evident now that sufficient cloud cover will remain in place beyond Wednesday. Models indicate moisture remaining over the Gulf of Mexico as Subtropical Jet Stream energy generates a surface low somewhere off the coast of South Texas. This is not anything that is set in stone at this point. Models also indicate that the air mass will be shallow with a continuation of SW winds above the surface. This weak overrunning will be enough to keep cloud cover in place. Also, there is hint of an upper level short wave (disturbance) holding back over the Desert SW. This would likely enhance the overrunning moisture across the area. There is so much uncertainty at this point, and until it becomes easier to decipher what models are ingesting here this will be a low confidence forecast. It will certainly be cold, that is the given. Thursday should be a dry day with just some intervals of sun, but Mostly Cloudy skies will be the dominant weather. Morning lows will be in the low to mid 20s across the forecast area, while afternoon highs will likely be about 25 degrees below the normal value for early February. This will mean highs falling short of 40 degrees in the mid to upper 30s. The winds will remain an issue as well, and wind speeds of 10-15 mph will generate apparent temperatures in the single digits and low teens in the morning, and only in the low-mid 20s in the afternoon.

The big time Arctic blast continues for Friday and Super Bowl weekend. Again, issues arise when determining if there will be precip or not. It should be noted that any precipitation that occurs in the Thursday-Saturday time frame will be in the frozen variety. However, all of this I am saying should be brushed with a fine tooth comb. Models suggest that our best opportunity for anything frozen (snow/sleet) will come on Friday. As the forecasted surface low translates NE through the Northern Gulf waters. This low would likely overthrow moisture into the forecast area. Dry air in place would likely limit precip amounts, and much of it may not even reach the ground with such a dry air mass in place. Forcing will increase as the low parallels the coast beginning Thursday night. At this time, I will mention only a slight chance of a wintry mix in the Thursday night-Friday time frame until better agreement comes into play. Temperatures will remain cold with another hard freeze on Friday morning. Temperatures will once again be in the low to mid 20s with upper 20s along the coast. Maximum temperatures will fall short of 40 once again on Friday, and depending upon the amount and extent of possible precip highs could be a few degrees colder for Friday afternoon, meaning we might struggle to get above freezing. Offshore flow will continue with the orientation of the Gulf surface low controlling the wind pattern. Yet, another hard freeze is scheduled for Friday night into Saturday. Additionally, some model runs have showed the upper level low out West opening up and shearing out across our region Friday night into Saturday. That could bring the potential for an additional chance of frozen precip. The slight 20% chance of precipitation will be maintained. Temperatures will once again fall to the mid 20s by sunrise Saturday.

This latest Arctic air mass will persist into Super Bowl weekend, but some modification will begin. Saturday will start out with another hard freeze, and perhaps some precip. However, as the low pushes on by in the Gulf skies will clear, and a Sunny day is expected for the balance of the day with Arctic high pressure continuing to be in control. High temperatures will be a bit warmer reaching the low to mid 40s across the region. The air mass will start to modify, and CAA will finally cease during the day as the Arctic high pushes Eastward. This Super Bowl weekend should be dry but cold. Clear skies and light winds will be place, and another cold night will be in place. However, only a light freeze is expected as a light return flow sets up across the area. A good deal of sunshine is expected for Super Bowl weekend. However, moisture levels will increase on Sunday ahead of another strong cold front. This front should be moisture starved due to such a limited time for return flow. High temperatures will continue their uptick. We should still fall short of normal with maximum reaching the mid 50s or so. A mix of sun and clouds is expected for Super Bowl Sunday afternoon. The timing of the next actual front looks to be on Sunday evening, perhaps during the big game itself. No rain chance is highlighted at this time. All indications are that another potent trough will be carved out by the Jet Stream over the weekend, and that will set up the possibility of another visit from the Arctic into the first part of next week. We'll put that on the backburner for now with all that we have on our plates this week.


Preliminary Numbers & Zone Forecast:


LCH  55/69  59/67  27/37  40 20 40 100 30 10
LFT   57/70  59/67  28/37  40 20 40 100 30 10
BPT   56/71  61/66  27/38  40 20 50 100 20 10
AEX  53/68  55/57  23/34  60 20 40 100 30 10
POE  53/68  55/56  23/34  60 20 40 100 30 10
ARA  60/70  61/68  28/38  40 20 30 100 30 10


Tonight...Cloudy with a 40% chance of showers & thunderstorms mainly before midnight. Areas of dense fog developing after midnight. Low 55. South wind 10 mph.

Monday...Areas of Dense Fog until mid-morning, otherwise Mostly Cloudy with a 20% chance of showers. High 69. South wind 10-15 mph.

Monday Night...Cloudy with showers & thunderstorms redeveloping overnight. Low 59. SSE wind 10-15 mph. Chance of rain 40%.

Tuesday...Rain & thunderstorms likely. Rainfall heavy at times. 1-2" of rainfall expected. Some severe weather with large hail and damaging winds the main threats. Isolated tornadoes are also possible. Turning Much Colder & Windy in the afternoon. High 67. Temperatures falling into the mid 40s in the afternoon. SSW wind 15-20 mph and gusty, becoming NNW at 20-30 mph and gusty in the afternoon. Chance of rain 100%.

Tuesday Night...Cloudy, Windy, & Much Colder with a 30% chance of rain in the evening. Low 27. NNW wind 25-30 mph and gusty. Wind chill values 5-15 by morning.

Wednesday...Partly to Mostly Cloudy, Windy, & Very Cold. High 37. NNW wind 15-20 mph and gusty. Wind chill readings 15-25.


Monday 1/31/11 Daily Planner

6a.m.

Weather: Fog











Temp: 55
Rain: 20%
Wind: S 7

9a.m.

Weather: Fog











Temp: 60
Rain: 20%
Wind: S 10

Noon

Weather: Mostly Cloudy











Temp: 65
Rain: 20%
Wind: S 12

3p.m.

Weather: Cloudy











Temp: 69
Rain: 20%
Wind: S 14

6p.m.

Weather: Cloudy











Temp: 64
Rain: 20%
Wind: SSE 11

9p.m.

Weather: Cloudy











Temp: 63
Rain: 30%
Wind: SSE 10


Drew's 7 Day Outlook


Monday
1-31-11











Low: 55
High: 69
Rain: 20%
Wind: S 10-15


Tuesday
2-1-11











Low: 59
High: 67...Falling to 45 late in the day
Rain: 100%
Wind: SSW/NNW 15-30


Wednesday
2-2-11
Groundhog Day
Low: 27
High: 37
Precip: 10%
Wind: NNW 15-25
W.C.: 5-25


Thursday
2-3-11











Low: 24
High: 38
Precip: 10%
Wind: NNW 10-15
W.C.: 10-25


Friday
2-4-11











Low: 25
High: 35
Rain: 20%
Wind: N 10-15
W.C.: 20s


Saturday
2-5-11











Low: 27
High: 45
Precip: 10%
Wind: ENE 10
W.C.: 20-35


Sunday
2-6-11
Super Bowl Sunday











Low: 30
High: 55
Rain: 10%
Wind: SSE/SSW 10-15
W.C.: 25-40


...Marine Forecast...


Tonight...Southeast winds around 10 knots. Seas 2 to 3 feet. A chance of showers and isolated thunderstorms in the evening. Areas of fog after midnight.

Monday...Southeast winds 10 to 15 knots. Seas 2 to 3 feet. Areas of fog. A slight chance of showers in the late morning and afternoon.

Monday Night...Southeast winds 10 to 15 knots increasing to 15 to 20 knots after midnight. Seas 2 to 3 feet building to 3 to 4 feet after midnight. A chance of showers.

Tuesday...South winds 20 to 25 knots becoming southwest in the afternoon. Seas 4 to 5 feet. Rain and scattered thunderstorms in the morning...then rain likely and scattered thunderstorms in the afternoon.

Tuesday Night...Northwest winds 20 to 25 knots. Seas 4 to 6 feet.

Wednesday...North winds 20 to 25 knots decreasing to 15 to 20 knots in the afternoon. Seas 5 to 6 feet subsiding to 4 to 5 feet in the afternoon.


...Tide Data...

Monday Tides @ Calcasieu Pass:

Low:           6:52a.m.         8:02p.m.
High:           3:23a.m.       11:47p.m.


...Toledo Bend Pool Level...

    164.29'


...Lake Charles Climate Summary...


Sunday, January 30, 2011


Low:                59
Normal Low:   42
Record Low:   22-1966
High:                64
Normal High:   62
Record High:   81-2002

Rainfall

Today:                            1.33"
Month to Date:               5.06"
Normal Month to Date:   5.37"
Year to Date:                  5.06"
Normal Year to Date:     5.37"
Record:                          2.63"- 1959

Sensible Weather Observed:

Rain
Light Rain
Heavy Rain
Fog

One Year Ago (2010)

Low:     39
High:     44
Rain:     Trace

5 Years Ago (2006)

Low:     43
High:     73
Rain:     0.00"

10 Years Ago (2001)

Low:    50
High:    73
Rain:    0.00"


Sunrise Monday:   7:04a.m.
Sunset  Monday:   5:49p.m.


Hunting Times:

6:34a.m.-6:19p.m.


...Lunar Table...

New Moon- Thursday February 3

First Quarter- Friday February 11

Full Moon- Friday February 18

Last Quarter- Thursday February 24


Have a great Monday & God Bless!
-DM-

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