mezzacyclone

Is it me or has the GFS had a helluva U-turn in the last few runs? Arctic plunge yesterday from a mid Atlantic ridge and the convergence off the Greenland tip from tuesday onwards has vanished???

,,and again as per the 2011 season SB its gonna be strangled eventually due to the abundant shear and diminishing higher SST`s not to mention inevitable recurve. not far off a TD now though according to all estimates but another typical african wave looking very well set but destined for nothing more than a low end cane at best and even thats very unlikely even if it stayed on a low lat course?

We can see more in character with Irene as opposed to Katia with this one, regardless of the dealings it has to go through with the northern shear tagging along on the westward track. Only concerns, in terms of development and not possible life endangerment, are NHC`s unwillingness to develop until into the SW Bahamas (Turks & Caicos Islands)? http://raleighwx.americanwx.com/models/gfs/12zgfs850300mbsheartropicalGFSLoop.html therefore echoing your comments to some degree as above SS? where they are taking into account little strengthening due to the 20kn Shear plots to the North also proximity of various ULL`s? Still, a small disturbance with higher probable landfall tracks always outweigh the big fish?

NHC moved the 5 day Conus roughly 100 mile NE as previous edge was right on St Martin & Barbuda shoreline?

Interesting models (latest GFS 12z not lauded one bit due to slowing the movement too much under the steadfast Atlantic ridge? currently zipping along @ 15kn?) with 2 ridges nearly co-joining and even a low in the NW GOM beginning to develop at 96hrs? Little troughing SWestwards but we know Katia will have to contend with dry air incursions under the ridge regardless how potent she becomes but all in all and as said earlier post, we are gonna be watching this for quite a while until things are clearer? as fun as it is for the time being

NHC have raised the stakes to 70% TC formation for 92L no doubt the very low 5-10kn shear forecast a major decider but still so far out with high probability of formation have certainly got it a lot of attention already and the mid-atlantic ridge may well ease a westerly track anywhere between W 270° & WNW 292.5° causing concern for the lesser antiles & leeward islands etc. before a sharp turn NE threatening Bermuda but all tracks highly uncertain this early as opposed to the general alert for development regardless if a fish or not?

Irene centre has just left land near the NC/WV border @ Knotts island (back bay/currituck sound 36.28N 75.50W) and has a 300 mile track over sea, aside from flirting with land North of Atlantic city, she is still @950mb and despite no recent SFMR data the low level outflow extends a great distance all the way down into the Bahamas/Caribbean therefore despite her cat1 status, conflicting her shear size, it would be extremely foolish to cast her off as I would not be surprised at 80-90mph winds to affect the LI area and we have all seen the surge! A sting in the tail for what has been a very unusual Hurricane and continues too!

948.7mb (31.800N 77.267W) on the 1st NOAA Orion (mission 30) northward sweep over centre, previous AF308 pass 950.1mb yet 100mph+ peak FL wind

Irene has held together remarkably well today considering she`s been exposed to 15-20kn of vertical shear, hence no real strengthening due to tilt on the stack etc, Has a good chance of re-certifying herself now as a cat2 and possible cat3 as she`s very little shear to deal with for the run into NC. All models now in sync btw, with a LI landfall, very worryingly. Flight recon 29 AF308 is en route currently 50 miles north of Panama City Fl headed East,,,

Slight pressure rise to 943.8mb on last NW to SE sweep, max FL of 96kn in North quadrant on VM data so shes holding together very well despite being susceptible to vert shear which is a major increased worry once she`s clear of it?

942.3mb (ESP@ 29.433N 77.333W) on the last northern sweep roughly over centre, Earlier reports showed < half the eyewall remains (vert shear mentioned earlier?) therefore HWRC due?

Atmospheric fluid dynamics is not my forte` in the least but i`d assume so along with surface level wind and more obviously topography? Irene is exposed to quite high vertical shear at the moment with the envigorated trough over the SE states a possible culprit (for want of a better word?)

mission 26 (NOAA Orion) has left Tampa and just Observed right over Vero beach East Fl coast headed East,,,,

It`s been a while since iv`e seen something this BIG in this part of the world? http://imageshack.us...tmo2011237.jpg/ 00:48(bst) NOAA2 lockheed Orion (26N 75.4W) recon about to turn NW to start a run over centre,,,,

944.5mb (27.467N 77.350W) was the lowest on the last AF306 sweep as the plane pulls away NW,,,

(ESP) 946.1mb 27.350N 77.267W and looks to be strengthening slightly/better organised on latest runs,,,

18:46: 947.7mb 26.467N 77.200W

The GFS 12z loop is fully out and although she approaches the 78°W marker at 24hrs she then takes a NE turn before straightening again slamming into Morehead city NC @ 54hrs continuing North through Pamlico sound up to Virginia beachwith Chesapeake bay ahead. Mission 21 AF306 recon just leaving Fl east coast near Miami headed ESE @26k feet descending slowly,,(17:57 BST)

Looking for evidence of the reporter on Nassau quoting "an earlier 143mph gust on Cat island" ? fully substantiated i`d imagine after this 859mb level 117 knot (135 mph) wind from the ENE recording just recent,,,,

A trifle messy but just to give an idea of where the 2 craft were 10 mins ago> the AF plane is North of the NOAA craft toward the left of the picture just above "The Bahamas"

No signs of any weaknesses? wind level for 939mb height: 110° (from the ESE) 115 knots/132 mph (pls note as this will not be reflected at the surface)

948.6mb 25.183N 76.250W (11:26am bst) FL 109kn/125.3mph (30sec avg.) peak FL 112kn/128.8mph (10 sec avg.) 25.433N 75.967W

AF300 headed back into the maelstrom NE current> 24.550N 76.750W NOAA3 headed out SE current >24.517N 75.667W,,,