***TROPICAL ALERT*** TROPICAL STORM ETA (Late season tropical outlook discussion) (1 Viewer)

Just read on NOLA.com that Delta just climbed to Cat 3.
I'll default to the more informed members to put up all the maps and charts with the pretty colors.
:sad:
 
David Bernard said Hunters found a pressure of 949 on the latest run through, just before the newscast ended.
 
Large and dangerous hurricane Delta moving toward the NW Gulf of Mexico.

Delta becomes a category 3 hurricane with winds of 115mph

Tropical Storm Warning is extended west to Sargent TX

Hurricane Warning is in effect from High Island to Morgan City

Storm surge warning is extended west to High Island

Discussion:

Delta has continue to organized today with an eye finally starting to show up on both visible and IR satellite images. Most recent USAF mission pass through the center recorded a central pressure down from 968mb to 954mb and flight level winds of 110-120kts in the NE eyewall. Dropsonde data in the SW eyewall recorded winds near the surface of 110kts (125mph) The overall structure of the hurricane continues to improve and Delta will likely continue to intensify through the night. Delta is moving toward the NW around 15mph and should begin to turn toward the NNW and N tonight.

Tropical storm force winds extend outward 160 miles from the center and hurricane force winds 35 miles from the center

Track:
There has been no changes in the track forecast and Delta is moving along the forecasted track as expected. Along this track, Delta should make landfall over SW Louisiana Friday afternoon and evening. Due to the expected expansion of the wind field, TS warnings have been extended westward along the TX coast.

Intensity:
As mentioned the overall structure of Delta continues to improve with an eye appearing in satellite images and dual outflow channels to the north and the south helping to move rising air near the center of the hurricane outward. Conditions are near ideal for intensification through tonight, but as Delta moves northward over the western Gulf on Friday upper level winds will be increasing from the SW due to a trough over TX and sea surface temperatures will be decreasing as Delta nears the US coast. Both of these factors will likely lead to some degree of weakening, but exactly how much is in question and the point should be clear that regardless of weakening Delta will be a large and significant hurricane at landfall over SW Louisiana

Local Impacts:
  • Tides and seas will begin to increase today and peak on Friday as Delta moves into the NW Gulf. Water levels along the upper TX coast are expected to reach 1-3 feet above normally dry ground which will be similar to hurricane Hanna and hurricane Laura. At times of high tide some coastal flooding will be possible on Bolivar, the west end of Galveston, Surfside, Sargent, and the west side of Galveston Bay. Additionally wave run-up along the coast could result in locally higher values. Late Friday as winds become NNW and NW over Galveston Bay, this will drive water in the Bay southward and toward the north sides of Galveston and Bolivar which may result in some backside flooding in those areas.
  • Rainfall will generally average less than 2 inches east of I-45 in some outer squalls on the west side of Delta. There may be some interaction with the trough over central TX and the western side of the circulation of Delta that may result in some enhancement of rainfall a bit further inland on Friday.
  • Tropical storm force winds will be possible in the TS warning area, although this will be heavily dependent on the expansion of the wind field and Chambers and southern Liberty Counties have the greater risk of sustained tropical storm force winds. Could see sustained tropical storm force winds in and around Galveston Bay on Friday and over southeast Harris, Galveston, and coastal Brazoria Counties.
Louisiana Impacts
  • Life threatening storm surge of 7-11 feet above the ground now likely over SC LA from where the center makes landfall east toward the Grand Isle and Port Fourchon areas including Vermillion Bay. In areas around Vermillion Bay this level of storm surge would be about 5-6 feet higher than that observed with hurricane Laura. Values between Cameron and Pecan Island which were heavily impacted by Laura are forecast to be between 4-7 feet including Grand Chenier and Creole. It should be noted that storm surge may extend well inland over the flat marsh lands of southern Louisiana and those locations that are not directly on the coast, could still experience significant storm surge impacts.
  • Rainfall will generally be 6-10 inches along the track of the hurricane and due to the fast forward motion, widespread significant flooding is no expected.
  • Tropical storm and hurricane force winds will impact a large area of SW and SC LA including those areas recently impacted by hurricane Laura. Due to the fast forward motion, strong winds will extend well inland along the track of Delta including the Abbeville, Lafayette, New Iberia, and Crowley areas.

Jeff Lindner
Director Hydrologic Operations Division/Meteorologist
Harris County Flood Control District
 
The latest track seems to suggest it will come through NE Louisiana as a Tropical Storm east of Monroe sometime very early Saturday morning. Hopefully that means Ouachita Parish won't get hit as hard as we did by Laura.
 
It may be a temporary jog, but the latest satellite shows Delta may have began a more northerly track.




That would be good for LC if they predict the NE movement within next 24 hrs. Would bring delta closer to Vermilion Bay. Bad for New Iberia but dang those folks in LC just don't need this.
 
Major hurricane Delta approaching the SW Louisiana and upper TX coast.

Conditions along the coast will be deteriorating today as both storm surge and winds increase.


Discussion:
USAF and NOAA aircraft have been in Delta all night and it appears the hurricane has bottomed out on the pressure around 953mb and winds of 120mph. Recent passes indicate the pressure may be starting to rise and the satellite images show a general erosion on the southwest side and no longer show an eye feature. It appears the much anticipated SW wind shear along the TX coast is starting to impact the hurricane. Overnight, Delta passed nearly directly over NOAA Buoy 42002, 200 miles east of Brownsville which gusted over 70kts and reported seas of 35 feet. Currently, NOAA buoy 42019, 60 miles south of Freeport is gusting to 52mph and 17 foot swells. Anadarko Oil platform (KGUL), 165 feet in the air has gusted to 85mph this morning.

Tide stations along the upper Texas coast indicate that water levels are between 1-2 feet above MHHW (vegetation line) currently and high tide was around 1-3am this morning. Since the high tide, there has been very little decrease in the water level and this is due to the push of the water ahead of Delta and the increasing large swells now marking their way onto the coast. Tides levels will hover in the 1-3 feet above MHW range for much of the day.

The center of Delta is roughly 160 miles SE of Galveston and tropical storm force winds extend outward 160 miles from the center. Tropical storm conditions are nearing the upper TX coast and Galveston North Jetty is gusting to 37mph currently. As the hurricane moves slightly closer to the upper TX coast before turning NNE later this morning, tropical storm force winds will expand into the areas around Galveston Bay, and especially over Chambers County.

Radar shows the outer western rain shield of Delta has expanded into SE TX overnight with numerous squalls approaching the coast. There will be a fairly sharp gradient in the rainfall today with areas west of I-45 and SH 288 likely experiencing the lower amounts and areas east of that line 1-2 inches, especially in Chambers and Liberty Counties.

Conditions should begin to rapidly improve this evening as Delta moves inland over southwestern Louisiana.

Jeff Lindner
Director Hydrologic Operations Division/Meteorologist
Harris County Flood Control District
 

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