Hello all. It is good to be back in the saddle after vacation, and a few days catching up. There are tons of pictures from vacation that will be posted soon, but for now let's get back to the business at hand. I'm a little rusty, but I'll give it the old college try. I have a nice new laptop too, and this should allow for a return of audio blogs this week. Give me a few days to tinker with the audio levels, until I find what I like. There is much to discuss, so without further delay here goes...
SW Louisiana Forecast Discussion...Whew! It is not your imagination, it really is as hot as it seems. The term dog days of summer has real relevance this year. It was yet another day of above normal temperatures with highs in the mid to upper 90s. Thankfully, today there was more in the way of convection and that kept readings from eclipsing the century mark. Some areas saw quite a bit of the very much needed rainfall. There were a couple of factors aside from the usual daytime heating that caused the convective activity to develop. The first, and more insignificant of these synoptic scale features was a stalled front over North Louisiana. Showers and storms fired along this boundary, and were aided by daytime heating. They pushed SW into the forecast area out ahead of the boundary. At the same time, the more influential feature, at least on our weather, the ghost of what was once Tropical Depression 5 tried to get better organized over the waters of the Northern Gulf of Mexico off the coast of NW Florida. Clusters of showers and storms rotated around the disorganized weak low pressure and moved from East to West across the Gulf South around the periphery of the tropical low, and some of this activity pushed into our area. This was primarily experienced over Acadiana and into the Atchafalaya Basin region. The heaviest showers and storms produced over 1" of rain, and this is essentially a harbinger of things to come for the next couple of days. Rain chances are on the increase, and in this case they will not necessarily be limited to the daytime hours.
As mentioned a moment ago, the former tropical depression is trying to re-generate. It's a coin flip as to whether or not it will do so, but some of our forecast models do suggest such an occurrence. If by chance this system does re-generate, it should remain a weak system, and the weather won't change all that much regardless. Of course, further revisions to the forecast that I am about to lay out for you are expected depending on the eventual strength and track of the former T.D. 5. The system is currently situated in the Northern Gulf of Mexico just offshore of Mobile, AL. It is only slowly moving West. Most of the convection with this system is on the W and SW side. This is a sign that it is still poorly organized, and the actual center of circulation is almost completely void of any convection tonight. Rain bands spiraling around the circulation will continue through the overnight hours. Therefore, the reason for inserting rain chances tonight. It will continue on the very warm and humid side with lows struggling to drop much below the 80 degree mark. Tuesday will mark a continued increase in rain chances, as the remnant low (or maybe re-generated T.D. 5) moves West. Hurricane Hunters have been investigating the low to see if it has re-gained tropical depression status, and so far this is not the case, but it will certainly have some time to strengthen over the warm waters of the Gulf. Upper level conditions are only marginally favorable at this juncture, but it won't take a whole lot for it to be re-classified as a Tropical Depression or even as Tropical Storm Danielle.
While it remains uncertain what is to become of the ghost of T.D. 5, the future track of the former system is a little more clear. It should continue on a general Westward heading through the forecast period, and on this track it should move very close to the coast of SE Louisiana sometime Tuesday. It will be a slow progression Westward, as the steering currents right over the top of the system are weak, but a building ridge to the North of the system will keep it on the Westward heading. It will move into SE Louisiana or perhaps parallel the coast of Louisiana through Tuesday. From there, it will continue its W to WNW motion and this will bring the center of circulation towards SW Louisiana. As the system draws closer late Tuesday into Wednesday, rain will continue to increase. Rain chances are in the likely category for Tuesday, and even higher for Wednesday based on the current projections. Rain chances will be highest over Acadiana and South Central Louisiana on Tuesday as they will be in closer proximity to the tropical low. Assuming, the system will remain lopsided and elongated, the most adverse weather could remain on its W and SW side, as opposed to a normal situation when most of the adverse weather is on the E and NE side. However, if the system undergoes better organization and tries to strengthen, then rain chances will be lessor for Tuesday due to the usual increased subsidence on the left side of the cyclonic flow. Some gusty winds are possible in the stronger storms through mid-week, but average wind speeds will be less than 30 mph. Some of Monday's storms produced winds over 50 mph in the Beaumont area. A repeat performance somewhere in the forecast area isn't out of the question for Tuesday. Regardless, what this system does, heavy rain and some flooding will be the main threat. Forecast models suggests upwards of 5" on average for most of the forecast area. I believe this seems a little overdone, especially for the Western half of the area (including Lake Charles). Granted, amounts of near 5" can't be ruled out through Wednesday with a few isolated locations receiving even more, but an average of 2-3" seems more logical across the forecast area as this low moves across. A Flash Flood Watch is in effect for Acadiana for Tuesday and Wednesday in anticipation of the heavier rain axis being in that area. A Flash Flood Watch could certainly be forthcoming for the rest of SW Louisiana depending on how the remains of T.D. 5 behave, and where the heaviest rain ends up falling. Stay tuned! Temperatures will respond to the increased clouds and rainfall across the area as well. Average highs will be in the low to mid 90s as opposed to the mid to upper 90s and low 100s that we've experienced for the last several days. Heat indices will still exceed 100 with copious amounts of low-level moisture in place to add insult to injury. Expect rain to remain in the likely category for the overnight hours Tuesday with the low in the area. A warm and humid and likely wet morning will greet us Wednesday with temperatures around 80 again.
It seems more likely that if any flood threat were to occur over immediate SW Louisiana it would be on Wednesday. Certainly, this will be the day that rain and some squally weather will be most likely to occur around these parts with the surface low passing through the forecast area. Exactly where it passes just remains to be seen, it could track over Lake Charles, or more towards Lafayette up towards Alexandria. Rain will likely be more on than off Wednesday, and it is then that a Flash Flood Watch could be in place for the Lake Area. Again, further revisions to this forecast are likely. This kind of forecast can have a large margin of error. For now, this forecast will be based on the fact that I believe the large influx of deep tropical moisture will continue pumping up over the area in response to the surface low. The clouds and rain will hold max temps down for a second day in a row, this time only reaching to around 90. This is believe it or not, below normal for mid-August. If nothing else, it will be nice to get some rain and just to have it cool off a bit across the area. It has been one miserable summer. Rain chances should start to taper down by Wednesday night as the low turns Northward somewhere in our vicinity in response to the anti-cyclonic flow around the re-building upper level ridge to our NE. However, it will take a while for the deep tropical moisture to be scoured out. Therefore, rain chances will certainly continue for the overnight hours Wednesday. Low temperatures will be similar.
The latter half of the work week will essentially be a transition. The remnant low will eject NE towards Thursday as it feels the effects of another approaching trough, and it traverses the periphery of the large Mid-South anticyclone. There will be lingering moisture in place, and this will combine with the usual effects of daytime heating to produce a better than average chance of diurnally driven shower and thunderstorm activity. The threat for heavy rainfall will exist once again especially in areas which receive a direct hit. The convective activity will certainly be back to a more typical hit or miss basis on Thursday, but depending how things evolve the next couple of days it could ultimately still be more hit than miss. There will undoubtedly be more sunshine on Thursday, therefore, we can turn up the heat once again. Temperatures will approach the mid 90s once again. There will also be gobs and gobs of humidity in place as it will take some time for the super moist lower levels of the atmosphere time to dry out. Heat indices will be nasty once again with readings back to near the hated danger category. A light onshore flow will prevail, but gusty winds will be possible near storms once again. Thursday will almost be the exact opposite of Tuesday, in that the highest rain chances should be over the Western half of the area. Most, if not all shower and thunderstorm activity will decay by nightfall as the pattern begins to resemble normal again. The deep moisture in the low-levels could certainly make it feasible that one or two storms will develop in the overnight hours Thursday, but overall a quiet night is expected with the average low in the upper 70s once again.
The end of the forecast period Friday through Monday should be a period of much quieter weather. We will complete a full transition back towards a more typical pattern for mid-late August. Upper level ridging processes take over once again, as has been the case for the majority of the summer of 2010. This will lead to below normal rain chances and above normal temperatures once again. The chances for showers and storms may not necessarily drop to near zero this time around, but the chances of any convectively induced activity will be on the slim side to say the least. Some lucky folks will get cooled down and wet down by some free air conditioning compliments of Mother Nature during the afternoon, but most of us will be left basking in the blazing August sun once again. Skies will generally be Mostly Sunny to Partly Cloudy for Friday through Monday, while temperatures range from the mid to upper 70s to around 80 for lows, and highs top out in the upper 90s on average again with many locations reaching or exceeding the century mark once again. Certainly, for the same time frame the heat indices will have to be monitored as they could easily reach into the danger category and approach the 110 degree threshold yet again. So, either way it appears this break in the intense heat is brief at best. We are about 13" below normal on rainfall for 2010, so we'll take all we can get over the next few days, because it seems that the incredibly dry pattern of summer 2010 is here to stay overall. This makes sense because we have transitioned to a La Nina pattern which typically offers up a drier regime around these parts. Briefly looking long distance out beyond this forecast period, late August looks to offer a continuance of the miserably hot and dry weather that has dominated us this summer. The tropics will also heat up as well, but only God knows where the storms will be. Just a reminder that we are now into the meat of hurricane season with the next several weeks through early October dubbed "prime time". Stay tuned for more on the remnants of T.D. 5.
Preliminary Numbers & Zone Forecast:
LCH 78/93 79/89 78/92 40 60 60 70 60 40
LFT 78/92 80/89 79/93 60 70 70 70 50 40
BPT 77/95 78/91 79/91 30 40 60 70 70 60
AEX 75/97 75/93 77/96 30 40 60 70 60 40
POE 75/97 75/93 76/96 30 40 60 70 60 40
ARA 79/90 80/88 81/91 60 70 80 70 60 40
Tonight...Mostly Cloudy with a 40% chance of showers and thunderstorms. Some heavy rainfall possible. Low 78. Light NE wind.
Tuesday...Mostly Cloudy with showers & thunderstorms likely. Locally heavy rainfall possible at times. High 93. NE wind 10 mph except stronger near thunderstorms. Chance of rain 60%.
Tuesday Night...Cloudy with showers & thunderstorms likely. Rainfall heavy at times. Low 79. E wind 10-15 mph. Chance of rain 60%.
Wednesday...Cloudy with showers & thunderstorms likely. Rain heavy at times. High 89. SE wind 10-15 mph. Chance of rain 70%.
Wednesday Night...Mostly Cloudy with a 60% chance of showers & thunderstorms. Rainfall could be heavy at times especially before midnight. Low 78. SE wind 10 mph.
Thursday...Partly to Mostly Cloudy with a 40% chance of showers & thunderstorms. High 92. South wind 5-10 mph.
Tuesday 8/17/10 Daily Planner
6a.m.
Weather: Mostly Cloudy, A Chance for Early Morning Storms
Temp: 78
Rain: 30%
Wind: NE 3
9a.m.
Weather: Mostly Cloudy, Some Storms Around
Temp: 83
Rain: 40%
Wind: NE 5
Noon
Weather: Mostly Cloudy, A Good Chance of Showers & Storms
Rain: 60%
Wind: ENE 6
H.I. 97
3p.m.
Weather: T-Storms Likely
Temp: 93
Rain: 60%
Wind: ENE 8
H.I.: 103
6p.m.
Weather: Showers & Storms Likely
Temp: 88
Rain: 60%
Wind: E 8
H.I.: 99
9p.m.
Weather: Mostly Cloudy, Off & On Rain Continuing
Temp: 82
Rain: 60%
Wind: ESE 5
Drew's 7 Day Outlook
Tuesday
8-17-10
Low: 78
High: 93
Rain: 60%
Wind: NE 5-10
H.I.: 98-103
U.V.: 10- High
Wednesday
8-18-10
Low: 79
High: 89
Rain: 70%
Wind: SSE 10-15
H.I.: 98-103
U.V.: 9- High
Thursday
8-19-10
Low: 78
High: 92
Rain: 40%
Wind: SSE 10-15
H.I.: 102-107
U.V.: 10- High
Friday
8-20-10
Low: 77
High: 95
Rain: 30%
Wind: SSW 10-15
H.I.: 103-108
U.V.: 11- Very High
Saturday
8-21-10
Low: 77
High: 98
Rain: 10%
Wind: W 5-10
H.I.: 105-110
U.V.: 11- Very High
Sunday
8-22-10
Low: 78
High: 98
Rain: 10%
Wind: W 5-10
H.I.: 105-110
U.V.: 11- Very High
Monday
8-23-10
Low: 78
High: 97
Rain: 20%
Wind: SSW 10
H.I.: 105-110
U.V.: 11- Very High
...Tropical Update...
The remnants of former Tropical Depression 5 continued to be monitored in the Northern Gulf of Mexico. The poorly organized tropical low is slowly moving Westward towards SE Louisiana. The atmospheric conditions over the Northern Gulf of Mexico are marginally conducive for further development of the former T.D. 5. There is the potential for some further development on Tuesday as the system slowly trudges Westward, and it won't take much strengthening for the low to be re-classified as a tropical depression. There is about a 60% chance of this system becoming a classified tropical system before it makes landfall late Tuesday or Wednesday somewhere on the Louisiana coast. Another Hurricane Hunter Aircraft will investigate this system Tuesday morning to see if any change in intensity has occurred. Regardless, of any further organization, heavy rainfall and some gusty winds are expected across a large portion of the Northern Gulf Coast through mid-week. This system will likely move from near SE Louisiana Tuesday to SW Louisiana by Wednesday. Rainfall totals of 2-6" will be common across much of Southern Louisiana through Wednesday with higher amounts to near 10" possible. Some minor coastal flooding and localized flooding from the expected rainfall is possible through Wednesday. Stay tuned for more information on this system.
Elsewhere in the tropics, all is quiet for the time being, but this will likely change in the days ahead as we are now into prime time hurricane season through early October. No other tropical cyclone formation is expected through Wednesday.
...Marine Forecast...
Tonight...Northeast winds 5 to 10 knots. Seas 1 foot. A chance of showers and thunderstorms.
Tuesday...Northeast winds around 5 knots becoming southeast in the afternoon. Seas 1 foot. A chance of showers and thunderstorms.
Tuesday Night...Southwest winds 5 to 10 knots. Seas 1 to 3 feet building to 2 to 3 feet after midnight. Showers and thunderstorms likely.
Wednesday...Southwest winds 5 to 10 knots. Seas 2 to 3 feet. Showers and thunderstorms likely.
Wednesday Night...South winds 10 to 15 knots. Seas 2 to 3 feet. A chance of showers and thunderstorms.
Thursday...Southwest winds around 10 knots. Seas 1 to 3 feet subsiding to 1 to 2 feet in the afternoon. A chance of showers and thunderstorms.
...Tide Data...
Tuesday Tides @ Calcasieu Pass
Low: 5:11a.m. 4:21p.m.
High: 12:17a.m. 7:34a.m.
...Toledo Bend Pool Level...
167.65'
...Lake Charles Climate Summary...
Monday, August 16, 2010
Low: 82
Normal Low: 74
Record Low: 62-2004
High: 95
Normal High: 91
Record High: 102-1951
Rainfall
Today: Trace
Month to Date: 0.25"
Normal Month to Date: 2.35"
Year to Date: 22.63"
Normal Year to Date: 35.59"
Record: 1.80"- 1899
Sensible Weather Observed Today:
None
One Year Ago (2009)
Low: 77
High: 91
Rain: 0.02"
5 Years Ago (2005)
Low: 73
High: 94
Rain: 0.00"
10 Years Ago (2000)
Low: 76
High: 96
Rain: 0.00"
Sunrise Friday: 6:41a.m.
Sunset Friday: 7:52p.m.
...Lunar Table...
First Quarter- Tonight August 16
Full Moon- Tuesday August 24
Last Quarter- Wednesday September 1
New Moon- Wednesday September 8
Have a Great Tuesday & God Bless!
-DM-
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