CoconutCandy
(User)
Sun Sep 02 2007 12:00 PM
Attachment
Felix Strengthens to Solid Cat 2 Hurricane

Felix is definitely engaging in a major intensification cycle this morning.

A special 3:30am AST update from the NHC relayed that the Hurricane Hunters are now reporting sustained winds of 100 mph, ratcheting Felix up to Cat 2 status.

And, since the satellite has come out of eclipse last night, it appears that inner core convection is steadily expanding (and deepening), although most of the deepest convection is clearly confined to the eastern semi-circle. Not too sure why this is so, as the system is not experiencing any shear. Any ideas here, Mets? Morphological considerations?

But the lop-sided eyewall convection scenario is apparently not inhibiting steady strengthening, as Felix is now at solid Cat 2 strength, with no end in sight at this point.

Here's what the good folks at the NHC had to say about Felix's Surge in intensity, in their 5am advisory:

>> "FELIX HAS RAPIDLY STRENGTHENED OVERNIGHT. AN AIR FORCE RECONNAISSANCE AIRCRAFT MEASURED MAXIMUM FLIGHT-LEVEL WINDS OF 93 KT AND A CENTRAL PRESSURE OF 984 MB DURING THE LAST EYE PENETRATION ... IN ADDITION, AN EYEWALL DROPSONDE MEASURED SURFACE WINDS OF 85 KT DERIVED FROM THE MEAN WIND IN THE LOWER LAYER OF THE SOUNDING. BASED ON THESE DATA THE ADVISORY INTENSITY IS SET TO 85 KT.

WHILE THE EYE HAS NOT YET BECOME DISCERNIBLE IN CONVENTIONAL GOES INFRARED IMAGERY...IT IS CLEARLY EVIDENT IN RADAR IMAGERY FROM CURACAO AND IN PASSIVE MICROWAVE IMAGERY FROM A TRMM OVERPASS."

And, since the time I wrote about the 'lop-sided' eyewall, just in that brief time the eyewall has undergone a dramatic rapid transformation and is now a complete eyewall again with a tight spiral and massively expanding eyewall convection in the NE semi-circle bursting forth. (See satellite IR link, below.) Hmmm ... A harbinger of further rapid intensification?? Any ideas here, Mets?

Beautiful is the splendid view of the 1km zoomed image of the first visible daylight satellite picture on NRL's website.

Please view the attachment, from the NRL website, to visually follow along with the narrative.

With the low sun angle, it shows well the developing dimple of the eye, like an inverted cone, as this 'inner eye cloudiness' is being evaporated by the ever-increasing warm temperatures, likely to reveal a clear eye within a few hours.

Also interesting, with the low sun angle, you can clearly see a partial ring of very deep thunderstorms in the eyewall's south quadrant, of what's known as 'convective turret penetrations', as the tops of these strong storms literally overshoot the tropopause, where the stratosphere begins. Only extremely strong thunderstorms can do that; most just 'flatten out' into the characteristic anvil-shape when they hit the tropopause. There are 100+ mph winds blowing below those storms, with even higher winds at "flight level".

Meanwhile, the radars from Venezuela, picking up the eyewall quite nicely, show the strongest reflectivity in the south quad, which correlates well with the visible satellite image of the eyewall. Is this interesting to anyone else?

The good news is that the official forecast track appears to have been adjusted slightly left, or southward again, apparently based on thinking that the ridge will remain intact and strong enough to continue to steer Felix generally west or west-northwest.

The bad news is that Felix is now expected to strengthen to at least 125 Kts., or 145 mph, before landfall, possibly in Belize, after grazing the tip of Honduras.

>> "ALL FACTORS POINT TO CONTINUED INTENSIFICATION...AND THE NEW OFFICIAL FORECAST IS ADJUSTED UPWARD MAINLY TO REFLECT THE OVERNIGHT STRENGTHENING JUST OBSERVED...AND SO IS HIGHER THAN MOST OF THE OBJECTIVE GUIDANCE.

FELIX APPEARS ON ITS WAY TO BECOMING A MAJOR HURRICANE OVER THE CARIBBEAN...BUT HOW MUCH LAND IT TRAVERSES BEYOND 48 HOURS MAKES THE LONG-RANGE INTENSITY FORECAST VERY UNCERTAIN."

No repeat of Hurricane Mitch, thankfully. Although Felix *might* become as large and even as strong as Mitch, the subtropical ridge to its' north should keep the monster storm trucking right along at a steady clip. Mitch, as you may remember, moved to a position just north of Honduras, and then weak steering currents kept massive and powerful Mitch meandering for days in roughly the same area, unleashing torrential rains and causing massive mudslides and the tragic loss of thousands of lives. Felix will be severe, even catastrophic, where he makes landfall, but at least it'll be over in a day or less, if anything 'good' could be said about the otherwise bad news for those in the path of Felix's Fury!

Well, it's nearly 2am in Hawaii (8 am Florida) so I think I'll close here and turn it over to the 'day crew' to discuss Felix to your hearts' content. I've a feeling that I'll wake up to a Major Cat 3 Hurricane, by the time the sun rises again in Hawaii.

6 hour IR loop:
http://weather.hawaii.edu/satellite/sata...amp;overlay=off

6 hour Visible loop:
http://weather.hawaii.edu/satellite/sata...amp;overlay=off

(Remember to click 'Rock' and slow it down just a tad, for best results.)



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