Thursday, September 16, 2010

Humidity Returns...Uneventful Weather Pattern Through the Period...

Thursday, September 16, 2010

Video Blog Discussion



SW Louisiana Forecast Discussion...Wednesday was a day featuring Mostly Sunny, and pleasantly low humidity once again. Dry air remained locked in place at the surface, but the surface high pressure providing the drier air is shifting to the East. This means that a return of Gulf moisture is hanging in the balance. After another coolish start with readings in the mid 60s to lower 70s across the area, temperatures warmed up quickly reaching the lower to middle 90s yet again Wednesday afternoon. There was very little in the way of cloud cover with the lower humidity values in place. Certainly there was nothing in the way of rainfall either. It will be a calm and clear start to the day on Thursday. The brief pleasant feel to the air of the last couple of mornings will be non-existent. A return flow of Gulf moisture has ensued, and moisture is increasing rapidly in the lower levels. Given this scenario, morning low temperatures will be back into the lower to middle 70s on average with some upper 60s possible further North.

A mostly dry regime will continue despite the return of the low-level moisture. A slight chance for an afternoon shower and thunderstorm will be back in the forecast beginning Thursday, but the emphasis here is on slight. This is despite the fact that there will be a tropical system in the Southern Gulf. Tropical Storm Karl, which will likely emerge into the Gulf this morning as a tropical depression will continue its Westward journey after spending most of Wednesday over the Yucatan Peninsula. Karl should quickly re-intensify with favorable conditions over the Gulf. It will likely become a hurricane Friday before making landfall early Saturday. The fact that Karl will be a stronger system will help keep the deepest moisture suppressed further to our South over the Bay of Campeche. The orientation of the tropical cyclone will allow for a deep influx of tropical moisture to filter into the region. Thus, high humidity and dew points will be in store once again. It will feel very much like a late summer day. Afternoon highs will reach the lower 90s while heat indices come back into play with readings nearing the century mark during the peak heating hours.

No change in the forecast philosophy from the previous forecast package for the Friday-Sunday period. The general pattern of deep tropical moisture in the lower levels will remain in place. Drier air will remain entrenched in the mid and upper levels with the prevailing Bermuda high situated over the Gulf Coast. This will keep the slight possibility of an afternoon shower or storm in the forecast, but whoever happens to get one of these natural air conditioners will be considered mighty lucky. The popcorn type showers and storms will strictly be on a hit or miss basis, more likely miss than hit. In fact, I will remove any mention of rain from the official forecast for the weekend as it seems chances will be negligible as the controlling high over the Gulf Coast builds back over the region. This pattern is not favorable for our drought stricken region. There will be no weather worries for any football games be it High School Football on Friday or College Football on Saturday. All other weekend activities are subject to a thumbs up as well with this persistent pattern in place. Warm and humid weather is on tap with temperatures in the 80s for many of the games. Morning lows for the Friday-Sunday period will be in the middle 70s with some lower 70s possible by Sunday as some drier air works in behind Karl. Highs each day will be in the lower 90s, just above normal for mid-September. A persistent onshore flow will continue for the entire weekend.

A pesky, persistent pattern will continue its dominance as we get into next week. No sign of any significant rain chances, and no more than just a slight 20% chance is indicated through the end of the forecast period. It is solely the effects of daytime heating that will generate the usual random smattering of showers and storms each afternoon Monday-Wednesday. The ridge will continue to be anchored across the Gulf rim, and will just move very little from day to day. The above normal temperature regime will continue as well with lower 70s for lows and lower 90s for highs. Climo for mid-late September is upper 60s for lows and upper 80s for highs. The fact that above normal temperatures, and below normal rainfall will continue is a microcosm of the summer of 2010, and typical of a La Nina pattern as well. The good news is that all tropical system will remain safely away from the forecast area as long as this high is in place. The idea of a real cold front is still on the table for the latter portion of next week, but since it is still beyond this forecast period I won't nibble on this idea just yet. We are very near the time of year climatologically when we experience our first real cold front, so it can't be too far away now can it? In a La Nina pattern, it is likely that a nice cool down will come later than normal. This is the opposite of last year when the fronts started coming early. That was the mark of an El Nino around these parts. So, it's all about a balancing out so to speak. We can cheer on the idea of a front...I know I am!


Preliminary Numbers & Zone Forecast:


LCH  74/92  75/95  75/94  0 20 0 20 0 10
LFT   73/93  75/94  75/95  0 20 0 20 0 10
BPT   75/94  76/95  75/95  0 20 0 20 0 10
AEX  71/95  74/97  74/96  0 20 0 10 0 10
POE  71/95  75/96  75/96  0 20 0 10 0 10
ARA  75/91  76/94  76/93  0 20 0 20 0 10


Today...Partly Cloudy with a 20% chance of an afternoon shower or thunderstorm. High 92. SSE wind 10 mph.

Tonight...Mostly Clear. Low 75. Light SSE wind.

Friday...Partly Cloudy with a 20% chance of an afternoon shower or thunderstorm. High 95. South wind 10-15 mph. Heat index values 100-105 in the afternoon.



Friday Night...Clear. Low 75. Light South wind.

Saturday...Partly Cloudy. High 94. South wind 10-15 mph.


Thursday 9/16/10 Daily Planner

6a.m.

Weather: Mostly Clear

 









Temp: 74
Rain: 0%
Wind: SSE 2

9a.m.

Weather: Partly Cloudy











Temp: 81
Rain: 0%
Wind: SSE 5

Noon

Weather: Partly Cloudy

Temp: 87
Rain: 10%
Wind: SSE 8
H.I.: 95

3p.m.

Weather: Partly Cloudy











Temp: 92
Rain: 20%
Wind: SSE 10
H.I.: 102

6p.m.

Weather: Partly Cloudy











Temp: 88
Rain: 10%
Wind: SSE 8
H.I.: 97

9p.m.

Weather: Mostly Clear











Temp: 83
Rain: 0%
Wind: SSE 3


Drew's 7 Day Outlook


Thursday
9-16-10











Low: 74
High: 92
Rain: 20%
Wind: SSE 10
H.I.: 98-103
U.V.: 10- High


Friday
9-17-10

Low: 75
High: 95
Rain: 20%
Wind: S 10
H.I.: 100-105
U.V.: 11- Very High


Saturday
9-18-10











Low: 75
High: 94
Rain: 10%
Wind: S 10
H.I.: 100-105
U.V.: 11- Very High


Sunday
9-19-10











Low: 73
High: 93
Rain: 10%
Wind: S 8-13
H.I.: 98-103
U.V.: 11- Very High


Monday
9-20-10











Low: 73
High: 93
Rain: 20%
Wind: SSE 8-13
H.I.: 98-103
U.V.: 11- Very High


Tuesday
9-21-10











Low: 72
High: 93
Rain: 20%
Wind: SSE 10-15
H.I.: 98-103
U.V.: 11- Very High


Wednesday
9-22-10
Low: 72
High: 91
Rain: 20%
Wind: SSE 10-15
H.I.: 95-100
U.V: 11- Very High


...Tropical Update...

A lot to discuss in the tropics again this go around. We still have 3 active storms. At one point during the day on Wednesday, we had two category 4 storms in the Atlantic basin at the same time. This is a feat that has not occurred since the 1920s. Igor remains a category 4, but Julia has since weakened, but remains a major hurricane. Karl, the youngest of the three ongoing tropical entities, made landfall over the Yucatan Peninsula near Chetumal, Mexico Wednesday morning as a tropical storm. Karl will emerge into the Gulf of Mexico this morning, and re-strengthen. The good news that the forecast reasoning for each of these storms has not changed at all since the last forecast package. Let's get into the usual specifics.

First, Igor...Igor continues to behave as expected. The large Atlantic subtropical ridge continues to be the driving force behind the steering pattern for Igor. Igor has been the beneficiary of excellent environmental conditions over the open waters of the Atlantic. Igor went through a period of rapid intensification on Tuesday, and was on the threshold of category 5 status early Wednesday morning. Igor has since leveled off in intensity, and has gone through some of the usual eyewall replacement cycles that large hurricanes experience. It is nearing the completion of one such ERC at this time. Igor remains a very large and dangerous category 4 storm early this morning. As I said earlier, there is no change to the forecast thinking with this package. The only questions are how strong will Igor be as it impacts Bermuda over the weekend, and will Bermuda sustain a direct hit? These questions will be answered in due time as we approach the weekend. Igor will remain a hurricane more than likely as it makes its closest approach to or direct hit on Bermuda Sunday. It should be in a weakening state by that time as the large cyclone moves into waters that will be less conducive for development, and into an area where wind shear will be present.

Igor is just barely North of 20 N at this time, but will begin gaining latitude for the rest of the work week as it takes on a more Northerly component of motion. Igor is approaching a significant weakness in the large subtropical ridge over the Eastern Atlantic, and this is what will ultimately result in the Northward component. This should bring Igor in the general direction of Bermuda. Bermuda should experience its worst weather from Igor during the day on Sunday. On the current track, it seems that hurricane conditions will be felt across the tiny island nation with a direct hit still hanging in the balance. A wobble one way or the other will ultimately determine which side of Bermuda the eye will pass. Interests in Bermuda should closely monitor Igor's progression over the next few days, and begin preparing for hurricane conditions over the weekend. It is likely that Igor has peaked in intensity, but there will still be periodic fluctuations over the next day or so while the system remains in a favorable environment. A downturn in intensity is expected to commence by week's end as Igor feels the effects of the colder waters on approach to Bermuda. A general WNW motion is expected through the day on Thursday before Igor feels the full effect of the developing weakness and begins to make that NW to N turn. The only area that stands a chance to experience a direct hit from Igor is Bermuda. No direct impact will be felt in the United States, though dangerous rip currents and large waves are to be expected in the coming days along the Eastern Seaboard. Igor will move past Bermuda by Monday, and dwindle down to an extratropical or post-tropical entity by the latter half of next week over the cold waters of the North Atlantic. 

Hurricane Igor Advisory

10p.m. CDT Wednesday, September 15, 2010

...Igor Remains a Large & Dangerous Hurricane...Threatens Bermuda as a Weaker Hurricane Over the Weekend...

Latitude: 20.2 N

Longitude: 56.5 W

This is about 450 miles ENE of the Leeward Islands & 980 miles SE of Bermuda.

Maximum Sustained Winds: 135 mph w/ higher gusts. Igor is a category 4 on the Saffir-Simpson Hurricane Wind Scale. Some fluctuations in strength are possible for the next few days, but Igor is expected to remain a very large and dangerous hurricane. Hurricane force winds extend outward to 45 miles from the center, while tropical storm force winds extend out to 240 miles from the center.

Movement: WNW or 295 degrees @ 9 mph. This general motion is expected to continue through Thursday, with a gradual turn to the NW and an increase in forward speed sometime during the day Friday.

Minimum Central Pressure: 27.82" or 942 mb.


















Moving on to Julia now...Julia began a period of rapid intensification on Tuesday evening, and continued that trend into the day on Wednesday. Julia was able to rapidly strengthen thanks to ideal environmental conditions all the way out in the Eastern Atlantic. This is an area with a high oceanic heating content at this time, and this coupled with a low shear environment and high pressure anchored to the North of the cyclone all helped Julia mature into a major hurricane of category 4 status. However, Julia has likely peaked. The system should continue a steady weakening trend now as the favorable environment that it was in gets replaced by a more hostile one. Julia will be under the influence of wind shear from the South for the next few days. The shear is light at the moment, but will likely intensity with time through the rest of the work week. A closed cold core upper low is developing in the vicinity, and this is the synoptic feature which will lead to the increasing shear. The flow around this upper level low will be ingested into Julia, and gradual weakening is forecast through the period. The future track of Julia is one that remains largely unchanged as well. The forecast is very straightforward. Julia will move over the Eastern Atlantic open waters through the forecast period. It will be steered by the developing upper level low as well as the Atlantic subtropical ridge to its North. This will send Julia to the North, and eventually NE by the end of the forecast period as the storm goes around the periphery of the present anti-cyclone. The fast steering currents will also allow for a gradual acceleration in forward motion. Julia is no threat to any landmasses, and will likely weaken to tropical storm status by late in the weekend or first of next week.


















Finally, there's Karl...Karl moved inland as a tropical storm over the Southern Yucatan Peninsula Wednesday morning. Karl spread gusty winds and heavy rain over that region while beginning to weaken as per usual over land. However, this is not the end of Mr. Karl. Karl with a K emerged into the Southern Gulf of Mexico late Wednesday night. A re-strengthening will begin almost simultaneously as Karl begins to feed off of the warm waters of the Bay of Campeche. Ideal conditions for intensification await Karl as he steadily moves towards his fuel source once again. Given the very favorable set up over the Southern Gulf of Mexico, Karl will likely strengthen rather steadily, and should become a hurricane before making final landfall over the weekend. The future track of Karl is very certain. Karl will be steered nearly due Westward to the South of the large anti-cyclone situated along the Northern Gulf Coast. This will steer Karl into the coast of Northern Mexico sometime early Saturday. Little to no impacts will be realized along the U.S. Gulf Coast. Karl could reach hurricane status on Friday, and is poised to make landfall as a category 1 storm early Saturday most likely in the Mexican state of Veracruz. Models are remarkably consistent with Karl indicating an understanding of the synoptic pattern in place over the Gulf of Mexico. Karl is forecast to undergo a reduction in forward speed as it approaches the coast Friday into Saturday. Karl will bring minor wind damage to the coast of Mexico, and the bigger threat will be from the heavy rain which will cause life-threatening flash floods and mudslides over the very mountainous terrain of inland Mexico.

Tropical Storm Karl

1a.m. CDT Thursday, September 16, 2010

...Karl Emerges Into the Extreme Southern Gulf of Mexico...Poised to Re-Strengthen...No Threat to the U.S...Landfall Expected Over the Weekend as a Hurricane in Mexico...

Latitude: 19.7 N

Longitude: 91.2 W

This position places Karl about 45 miles WSW of Campeche, Mexico and about 410 miles ESE of Tuxpan, Mexico.

Maximum Sustained Winds:: 40 mph w/ higher gusts. Steady state strengthening is forecast for the next couple of days, and Karl could become a hurricane before landfall on Friday. Tropical storm force winds extend outward to 60 miles mainly to the West of the center.

Movement: WNW or 290 degrees @ 14 mph. A motion to the W or WNW is forecast to persist for the next few days, with a gradual reduction in forward speed. On this track, Karl will move across the Southern Gulf of Mexico and approach the Mexican state of Veracruz Friday.

Minimum Central Pressure: 29.53" or 1000 mb.

Watches/Warnings...A Hurricane Watch has been issued by the government of Mexico from La Cruz Southward to Barra de Nautla.

A Tropical Storm Watch is in effect for the Yucatan Peninsula of Mexico from Cuidad del Carmen to Celestun.

Wind...Tropical storm force winds in gusts are expected over a small area of the Western Yucatan Peninsula this morning before subsiding. Tropical storm conditions are to be expected by early Friday in the hurricane watch area with hurricane conditions Friday night.

Rainfall...Karl will produce rainfall accumulations of 1-2" over the Western portion of the Yucatan Peninsula, as well as portions of the state of Tabasco and Northern Guatemala. Isolated amounts to near 8" will be possible. Rainfall amounts of 5-10" are expected along the coast of Mexico within the hurricane watch area with isolated amounts of 15" possible over the mountains of Mexico. These rains will cause life-threatening flash floods and mudslides.


















The next advisory on all three systems will be issued by the National Hurricane Center at 4a.m. CDT Thursday.

Elsewhere, no tropical cyclone formation is expected through Friday.


...Marine Forecast...


Today
....East winds 10 to 15 knots. Seas 2 to 3 feet. A slight chance of showers and thunderstorms.

Tonight...East winds 10 to 15 knots. Seas 2 to 3 feet. A slight chance of showers and thunderstorms.

Friday...East winds 10 to 15 knots. Seas 2 to 3 feet. A slight chance of showers and thunderstorms.

Friday Night...East winds 10 to 15 knots. Seas 3 feet. A slight chance of showers and thunderstorms.

Saturday...East winds 10 to 15 knots becoming southeast in the afternoon. Seas 2 to 3 feet.


...Tide Data...

Thursday Tides @ Calcasieu Pass

Low:                  5:07p.m.
High:                  1:23a.m.


...Toledo Bend Pool Level...

    166.29'

...Lake Charles Climate Summary...


Wednesday, September 15, 2010


Low:              71
Normal Low:  71
Record Low:  51-1902
High:              93
Normal High:  88
Record High:  99-1906

Rainfall

Today:                             0.00"
Month to Date:                0.86"
Normal Month to Date:    3.07"
Year to Date:                 25.95"
Normal Year to Date:    41.16"
Record:                           3.10"- 1930


Sensible Weather Observed Today:

None


One Year Ago (2009)

Low:     73
High:     83
Rain:     Trace


5 Years Ago (2005)

Low:      74
High:      92
Rain:     0.00"


10 Years Ago (2000)

Low:     73
High:     94
Rain:    0.00"


Sunrise Thursday:   6:58a.m.
Sunset  Thursday:   7:17p.m.


Hunting Times:

6:28a.m.-7:47p.m.


...Lunar Table...
 
Full Moon- Thursday September 23

Last Quarter- Friday October 1

New Moon- Thursday October 7

Last Quarter- Thursday October 14


Have a Great Thursday & God Bless!
-DM-

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