Felicia not weakening; new African wave may develop
Hurricane Felicia has not weakened today, and continues to hold its own in spite of cool sea surface temperatures beneath it. Recent satellite imagery shows that the tops of thunderstorms surrounding the eye have cooled slightly, indicating that the updrafts sustaining the eyewall are maintaining their strength. The appearance of the hurricane has improved some today, with the storm assuming a more symmetric appearance.
Figure 1. Current satellite image of Hurricane Felicia.
Sea surface temperatures (SSTs) under Felicia have now fallen to 24.7°C, well below the 26°C threshold typically needed to sustain a hurricane. SSTs will slowly increase to 26°C by the time the storm reaches Hawaii, though. Wind shear is expected to remain low to moderate, 5 - 15 knots, through Monday morning. By Monday night, shear will rise to 20 knots, and remain above 20 knots thereafter. The higher shear combined with the relatively cool SSTs should mean that Felicia will be rapidly weakening in its final 24 hours before reaching Hawaii. Several of the computer models continue to show that this shear will be high enough to tear Felicia apart before it reaches Hawaii, though it appears to me that Felicia's current strength and annular structure will help it resist the shear enough to allow the storm to hit Hawaii as a tropical depression with 35 mph winds. Regardless, Felicia will bring heavy rain Hawaii beginning on Monday morning, and these rains will have the capability of causing flash floods and mudslides. The Hurricane Hunters are scheduled to make their first low-level investigation of Felicia this afternoon (around 10 am Hawaiian time). The NOAA jet also flies into Felicia today, and will drop a series of dropsondes that will be used to gather data that will be fed into today's 12Z and 00Z computer model runs.
Typhoon Morakot hits Taiwan
Typhoon Morakot hit Taiwan yesterday, battering the island with Category 1 winds and heavy rain. The Taipei airport recorded sustained winds of 56 mph, gusting to 76 mph, at the peak of the storm. Morakot killed 6 on Taiwan and 10 in the Philippines, and is headed towards a final landfall on mainland China as a tropical storm later today. Storm chaser James Reynolds intercepted the storm and posted videos on typhoonfury.com and Youtube. Morakot is still visible today on Taiwan radar.
Figure 2. Visible satellite image of a spinning tropical wave leaving the coast of Africa. The image was taken at 8am EDT 8/8/09.
African tropical wave may develop
A strong tropical wave with a moderate amount of spin is moving off the coast of Africa this morning. The wave is under about 10 - 20 knots of wind shear and has sea surface temperatures beneath it of 27°C. These conditions are probably too marginal to allow development over the next two days. As the wave moves westward away from Africa over the next few days, wind shear should slowly decrease and the SSTs will warm, potentially allowing for some slow development. The UKMET, GFS, and NOGAPS models all indicate the possibility that this will become a tropical depression 3 - 5 days from now. The ECMWF model forecasts that strong easterly winds over the wave will create too much shear to allow development. The wave is well south of the Saharan Air Layer, so dry air and African dust should not interfere over the next 3 - 5 days. I give the wave a medium (30 - 50% chance) of developing into a tropical depression in the next seven days.
I'll have an update on Sunday.
Jeff Masters
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Nothing is with absolute certainty...
Its likely though.
Of course not you should know that WS where it heads today might change tomorrow or even the next model run.
np :)
C and D are technically the same.
I choose both.
?
Only one person was saying that this could threaten SFL and that person is on my ignore list.
they have a guy in the background drawing on a map lol
The low level vorticity maximum has increased overnight and I still think there is a nearly closed if not closed low regardless of what the quickscat shows. The GFS 06z model analysis had an isobar around a 1010mb low. It continues to move slightly north of due west. How much poleward movement it gets will be dependent on how strong the system gets. The GFS remains the most northerly with the system while the UKMET, NOGAPS, and CMC take it on a more westerly course regardless of it's strength. A forecast cannot be solely based on the GFS model. The consensus would keep it south of 20N throughout the 6 day period for the time being.
LOL
Definitely
That goes to show you how things can change personally I think it way to early to know who it will or will not effect, besides there are other land areas that can be effected.
90E at East-Pacific was marked as yellow circle but next report will be TD.
And the GFS is notorious for its poleward biases.
Yeah I was noticing that the GFS seems to be the outlier with the northerly track so far. We'll see what the 12Z suite brings. Hopefully the GFDL is run.
LOL
It seems that way. We should see a TD tomorrow is this continues to organize.
OK, Drak. Thank you. I have been saying west or WNW for now. Everyone else has denied that and said WNW or NW. I am not so sure this is a guaranteed fish.
What? It wont go from yellow to TD.
The models show development on Wednesday.
You mean the BAMS
I see no indications that 90E will be updgraded
It shouldnt.
Especially if your talking about the 'Bill' wave. It has another wave coming off on Monday that should clear any potential SAL ahead of it. Conditions should be as favorable as there are for 99L.
-Low shear
-Little to no SAL
-Negative MJO
everyone? I posted a detailed explanation explaining why sat imagery looked more northerly but that it was moving generally west.
but asking the same ones over and over again, means you havent learned anything
LOL yes, that is very common.
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