The blog will be in short form for this update due to all the Katrina coverage. Regular format returns Monday.
SW Louisiana Forecast Discussion...5 years ago today Hurricane Katrina made landfall in SE Louisiana. It was by far the worst natural and man-made disaster ever. For more on Katrina, scroll down to the three previous posts below this one for a plethora of information on Katrina as we take a moment to look back and reflect on this somber anniversary. The muggies have returned with a vengeance this weekend as expected. The brief reprieve from the horrid heat and humidity of the summer of 2010 was nice while it lasted, but it has all gone by the wayside now. A deep flow of tropical air off the Gulf has returned to the region in response to a weak surface low that developed in the Gulf along the old frontal boundary. This boundary transitioned into an elongated trough and acted as a warm front feature as it lifted Northward Saturday. The weak surface low drifted inland today, and the end result was a scattered distribution of showers and thunderstorms. Heavier rain amounts occurred across the Eastern half of the area and over into SE Louisiana. The lower levels of the atmosphere have moistened up significantly, and this will greet us for the new work week to keep the mention of showers and thunderstorms in the forecast. A few showers and/or storms can't be ruled out tonight with the deep tropical air mass in place, but overall the loss of daytime heating should keep most of us dry. Generally Partly to Mostly Cloudy skies will be expected. Overnight lows will be in the mid to upper 70s, this comes after Sunday afternoon maximums in the lower 90s for most.
Not much change in the atmospheric set up is expected for Monday. The weak surface low and associated trough will remain in place across the region, and as the late August sun heats up the atmosphere, scattered showers and storms will initiate across the threshold of the forecast area. The trough will enhance the usual sea breeze activity, so that a better than average chance for convection should be realized. Convection may be ongoing in the coastal waters at dawn Monday given the rich, tropical air mass at the favorable set up for nocturnal activity over these parts. These storms will lift Northward over land Monday. The day should start on a dry and humid note for most, but many of us will get a nice wet down in the afternoon thanks to the enhanced moisture. Certainly, not everyone will get rain, and those that miss the boat will continue to bask in a hot, late August sun. Afternoon highs should average the low 90s, while heat indices will exceed the 100 degree mark. It could approach 105 in some locations, but it shouldn't be near as bad as the oppressive heat of earlier this month. As far as rainfall totals are concerned, locations which receive the heaviest rainfall and sustain a direct hit from one of Mother Nature's random air-conditioners could see in excess of 2". However, for the most part rainfall totals should be an inch or less on average. Most of the convection will fade away for the overnight hours, but again one or two storms over land will be possible with a better chance of nocturnal marine activity on the slate. Overnight lows will be in the usual mid to upper 70s range.
August comes to an end on Tuesday, but the typical summer pattern rolls on. The elongated surface trough will eventually fade away, but in its wake a plethora of low-level moisture will remain in place. Thus, a chance for scattered showers and thunderstorms will be regulated once again. It should essentially turn to be a normal late summer day. Drier air will take over in the mid and upper levels of the atmosphere in the wake of the elongated trough, but it is the high amounts of low-level moisture that will aid in the typical dose of scattered afternoon showers and storms. High temperatures will be at or slightly above normal for the end of August in the 90-95 range. While this is still in the hot category, it is bearable compared to where it was 10 years ago on August 31 (which is the date on Tuesday). On that date, the all-time record high was established at Lake Charles, and all other reporting sites in SW Louisiana for that matter. The mercury soared to an incredibly oppressive 107 degrees. Certainly, nothing like that is in the fold during this forecast period. The oppressive heat we've had this summer doesn't even compare to that most incredible heat wave back in 2000. The heat indices could be close to the danger category given the high humidity values in place. Partly Cloudy should be the main sky condition throughout the day, except of course, where the scattered storms develop. A quiet overnight is on tap as all convection fizzles out with the loss of daytime heating.
The remainder of the forecast period Wednesday-Sunday will resemble a typical pattern for early September. High pressure will be in control off to our East and West, while over our area a bit of a weakness will be in place. The fringe effects of the persistent Bermuda High will be the dominant weather feature, and as a result of this we will experience a continued onshore flow with plenty of low-level moisture in place. Drier air will continue in the mid to upper levels of the atmosphere. This pattern will favor the usual sea breeze induced convection during the afternoon hours with scattered showers and storms occurring at random locations around the forecast area each day. Partly Cloudy should prevail with morning lows in the mid to upper 70s, while afternoon highs exceed 90, and approach 95 in some areas. This is basically normal for early September as I mentioned previously. Better chances for the usual scattered convection will exist for the Wednesday-Thursday period (30%), but for Friday-Sunday rain chances will diminish just a fraction (20%) as somewhat drier air works its way into the lower-levels due to a change in orientation of the controlling highs. This bodes well for all events scheduled for the long Labor Day Holiday weekend. Any convection that forms during the day with be subject to dissipation after sunset leaving warm and humid conditions in place for the overnight period each night. This should provide for no weather worries for the first full weekend of football at the High School and College level. Later this week, I'll get specific about forecasts for each game, but pick out your favorite high school's game and the McNeese game, and there will be no worries. LSU is on the road in the GeorgiaDome, so the same applies there. The active tropical entities will have no impact on our weather...more on that in the tropical section below. Looking long range, the typical summer regime should carry us all the way through the Labor Day weekend, and into next week. There are no signs of a real cold front yet, but also I don't see any signs of another oppressive heat wave either.
Preliminary Numbers & Zone Forecast:
LCH 75/91 75/92 75/93 20 40 10 30 10 30
LFT 75/90 75/92 76/93 20 40 10 30 10 30
BPT 76/91 75/91 76/93 20 40 10 30 10 30
AEX 73/93 73/95 74/95 20 40 10 30 10 20
POE 74/93 74/94 74/95 20 40 10 30 10 30
ARA 76/89 75/91 76/92 20 40 10 30 10 30
Tonight...Partly Cloudy with a 20% chance of showers and thunderstorms. Low 75. SSE wind 5-10 mph.
Monday...Partly to Mostly Cloudy with a 40% chance of scattered showers & thunderstorms. High 91. SSE wind 10-15 mph.
Monday Night...Partly Cloudy. Low 75. Light SSE wind.
Tuesday...Partly Cloudy with a 30% chance of scattered showers & thunderstorms in the afternoon. High 92. SSE wind 10-15 mph.
Tuesday Night...Mostly Clear to Partly Cloudy. Low 75. Light SSE wind.
Wednesday...Partly Cloudy with a 30% chance of scattered afternoon showers & thunderstorms. High 93. SSE wind 10-15 mph.
Monday 8/30/10 Daily Planner
6a.m.
Weather: Partly Cloudy, A Few Coastal Storms Perhaps
Temp: 75
Wind: SSE 2
9a.m.
Weather: Partly Cloudy, Storms Firing Up
Temp: 82
Rain: 20%
Wind: SSE 5
Noon
Weather: Partly Cloudy, Sea Breeze Initiation
Temp: 87
Rain: 40%
Wind: SSE 11
H.I.: 94
3p.m.
Weather: Partly Cloudy, Scattered Storms
Rain: 40%
Wind: SSE 14
H.I.: 100
6p.m.
Weather: Partly Cloudy, Storms Winding Down
Temp: 88
Rain: 30%
Wind: SSE 10
H.I.: 98
9p.m.
Weather: Partly Cloudy
Temp: 83
Rain: 10%
Wind: SSE 4
Drew's 7 Day Outlook
Monday
8-30-10
Low: 75
High: 92
Rain: 40%
Wind: SSE 10-15
H.I.: 98-103
U.V.: 10- High
Tuesday
8-31-10
Low: 75
High: 92
Rain: 30%
Wind: SSE 10-15
H.I.: 98-103
U.V.: 10- High
Wednesday
9-1-10
2 Year Anniversary of Hurricane Gustav
Low: 75
High: 93
Rain: 30%
Wind: SSE 10-15
H.I.: 100-105
U.V.: 11- Very High
Thursday
9-2-10
Low: 76
High: 93
Rain: 30%
Wind: SSE 10-15
H.I.: 100-105
U.V.: 11- Very High
Friday
9-3-10
Low: 76
High: 94
Rain: 20%
Wind: SSE 10-15
H.I.: 100-105
U.V.: 11- Very High
Saturday
9-4-10
High: 95
Rain: 20%
Wind: SSE 10-15
H.I.: 100-105
U.V.: 11- Very High
Sunday
9-5-10
High: 95
Rain: 20%
Wind: SSE 10-15
H.I.: 100-105
U.V.: 11- Very High
...Tropical Update...
The tropics remain active as we near the end of August, and on this anniversary of the worst storm ever. Thankfully, there is nothing like that out there at the moment. We still have 2 hurricanes to discuss, but one will have no direct impact on the U.S., and one may threaten the Eastern Seaboard later in the week, but even it will have no impacts on the Gulf Coast Region. We also continue to watch the progression of another strong tropical wave in the Far Eastern Atlantic which seems poised to strengthen and become the next named storm of the season.
First, here's the latest on Hurricane Danielle. I won't spend a whole lot of time on Danielle. Danielle is in its decaying stages. It has safely bypassed Bermuda with no more than an increase in winds and seas and some occasional squalls. A trough late August trough has begun to shunt Danielle off to the NE, away from all landmasses, and affecting only shipping interests in the North Atlantic. Danielle is going to pass very near the site where the Titanic sank, and all operations on that expedition will have to be ceased. We won't have to discuss Danielle much longer as it is transitioning into an extratropical entity. It peaked as a category 4 storm on Friday, but has been weakening for the last 24-36 hours as it moves into an area of colder SSTs and ingests some shear in response to the aforementioned trough. Danielle will likely be downgraded to a Tropical Storm on Monday, and complete its transition to an extratropical cyclone within the next 24 hours. Here is the latest information on Danielle.
Hurricane Danielle Advisory
10p.m. CDT Sunday, August 29, 2010
...Danielle on the Downward Spiral...No Threat to Land...
Latitude: 39.3 N
Longitude: 53.0 W
This places the eye of weakening Danielle about 510 miles S of Cape Race, Newfoundland.
Maximum Sustained Winds: 80 mph w/ higher gusts. Danielle is a category 1 storm, and a continued weakening trend is expected through Monday. A transition to a large and powerful extratropical cyclone is expected to be completed on Monday. Hurricane force winds extend outward to 85 miles from the eye, while tropical storm force winds now extend outward to 310 miles from the eye.
Movement: NE or 45 degrees @ 16 mph. This motion is expected to continue through Tuesday.
Minimum Central Pressure: 28.94" or 980 mb.
The next complete advisory by the National Hurricane Center will be issued at 4a.m. CDT Monday.
Next, let's look at Earl. Earl was just barely getting his act together when we last spoke on Thursday. Earl has continued the maturation process this weekend while racing off to the West at the same time. Earl is now on the cusp of becoming the season's second major hurricane, and is bearing down on the Northern half of the Leeward Islands. Earl continues to strengthen, and the environment out ahead of Earl is one that continues to favor development. His strengthening trend could temporary be slowed by his interaction with the Leeward Islands, but since these landmasses are very small, it won't impede his development very much at all. Earl will bring hurricane conditions across islands such as Montserrat, St. Kitts, Nevis, Anguilla, Antigua, Barbuda, and St. Martin. It will move through the islands fairly quickly, and approach the Virgin Islands later in the day Monday. Earl continues to be steered around the Southern flank of an Atlantic anti-cyclone.
The trough that picked up Danielle may have an impact on Earl's future track. This upper level trough is currently forecast to shift Westward and weaken. This will also allow for the Atlantic ridge to build Westward simultaneously, thus Earl should continue moving around the Southern periphery of the aforementioned anti-cyclone. As the trough weakens and the ridge strengthens, Earl will begin to be nudged to the NW as he remains locked up in the circulation around the high. This should occur towards mid week or so. As Earl starts to slowly gain latitude, it appears that another late summer trough will evolve across the Eastern U.S. This is what the models suggest, and should this occur then Earl will be lifted to the N and then the NE paralleling the East Coast of the U.S. The current track keeps Earl just offshore of the Mid-Atlantic and New England States later this week, however, if the trough evolves slower then the threat of a landfalling hurricane somewhere along the Eastern Seaboard could be realized. Also, given the conducive environment out ahead of Earl once he moves away from the Leeward Islands, major hurricane status is likely to be obtained within a day or two. This idea is currently reflected in the official forecast. Earl could still be a major hurricane as he approaches the East coast, but at this time a weakening trend is suggested for the latter half of the week (day 4 and 5). While a threat to the Eastern Seaboard can't be ruled out, there is virtually no chance for Earl to have an impact on the Gulf Coast states.
Hurricane Earl Advisory
1a.m. CDT Monday, August 30, 2010
...Earl Strengthening as He Impacts the Lesser Antilles and Virgin Islands...Should Become Season's Second Major Hurricane Monday...
Latitude: 18.1 N
Longitude: 61.8 W
This places the eye of Hurricane Earl about 35 miles N of Barbuda and about 85 miles East of St. Martin in the Lesser Antilles.
Maximum Sustained Winds: 100 mph w/ higher gusts. Earl is a category 2 on the Saffir-Simpson Scale. Further strengthening is forecast Monday, and Earl should become a major hurricane within the next 24 hours. Hurricane force winds extend outward to 50 miles from the eye, while tropical storm force winds extend outward to 175 miles from the eye.
Movement: WNW or 285 degrees @ 15 mph. This general motion is expected to continue through Monday, before a gradual turn to the NW commences on Tuesday. On this track the eye of Earl will pass very near or over the Northern Leeward Islands early Monday, and near the British Virgin Islands late Monday.
Minimum Central Pressure: 28.61" or 969 mb.
Watches/Warnings...A Hurricane Warning is in effect for the following islands in the Lesser Antilles: Antigua, Barbuda, Montserrat, St. Kitts, Nevis, Anguilla, St. Martin, St. Barthelemy, St. Maarten, Saba, St. Eustasius, & the British Virgin Islands.
A Hurricane Watch is in effect for the U.S. Virgin Islands & Puerto Rico including the islands of Vieques & Culebra.
A Tropical Storm Warning is in effect for the U.S. Virgin Islands, & Puerto Rico including Vieques & Culebra.
Wind Impacts...Tropical Storm Conditions are overspreading portions of the Hurricane Warning area, and Hurricane Conditions are expected to spread into the region on Monday. The U.S. Virgin Islands and Puerto Rico can expect Tropical Storm Conditions Monday with the possibility of Hurricane Conditions Monday Night.
Storm Surge...Water levels will rise about 2-4' above ground level near the coast in areas of an onshore wind in the hurricane warning area, and 1-3' in the tropical storm warning area. The storm surge will be accompanied by large and dangerous battering waves.
Rainfall...3-5" of rain is expected over the Northern Leeward Islands with isolated amounts to near 8" possible. 4-6" of rain is expected over Puerto Rico with isolated amounts of 12" possible in the higher elevations. These rains may lead to life-threatening flash floods and mudslides.
The next complete advisory will be issued at 4a.m. CDT Monday.
Elsewhere, the Gulf and Caribbean are quiet at the moment, and no development is expected here through Tuesday. A series of tropical waves (storms over Africa) seem poised to emerge off the West Coast of Africa in the coming days. Given the environment over the tropical Atlantic, more tropical systems are expected in the weeks ahead.
...Marine Forecast...
Tonight...Southeast winds 5 to 10 knots. Seas 2 to 3 feet. A chance of showers and thunderstorms.
Monday...Southeast winds 5 to 10 knots. Seas 2 to 3 feet. A chance of showers and thunderstorms.
Monday Night...Southeast winds 5 to 10 knots. Seas 2 to 3 feet. A slight chance of showers and thunderstorms.
Tuesday...East winds 5 to 10 knots. Seas 2 to 3 feet. A chance of showers and thunderstorms.
Tuesday Night...East winds 10 to 15 knots. Seas 2 feet. A slight chance of showers and thunderstorms.
Wednesday...East winds 10 to 15 knots. Seas 2 to 3 feet. A chance of showers and thunderstorms.
Be sure to scroll down to see the 3 previous blogs on Hurricane Katrina.
Have a Great Monday & God Bless!
-DM-
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