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Friday, August 31, 2012

Tracking Leslie

With the dismal modeling of Isaac, which was originally out to sea, then up the coast, then Fl, then Tampa, panhandle and finally Louisiana, I thought it would be interesting to track Leslie and the furthest west she gets, before recurving, on each 0z and 12z run. Coordinates are W/N

0z Euro 68/35 on 9/10
0z gfs 67/33, now west of Bermuda
Crazy uncle CMC is now back on meds with 68/35ish
UKMET at 120 is at 68/33
I would call this a consensus, but still interested to see a) if Isaacs remnants which dove south tangle with the front coming through the midwest and start something on either side of FL and b) or is there a cut off low instead that influences Leslie a bit farther west. Most longer range models showing landfall in Canada at this point. Utimate endgame still has some spread per graphic below.

0z Euro 68/36 on 9/9
0z GFS 63/24 today -it brings it east a bit then due north along 62W until 9/10
Crazy Uncle, CMC still heads it towards the Cape and hits Maine
Nogaps east of GFS
UKMET makes it to 70/35 hr 144
Spread between UKMET and Nogaps is 540 miles at hr 144

12z GFS 63/34 before turning ots
12z EUro 69-36 Grazes Cape cod, follows coast from Maine to NS.
12z CMC getting close to Cape Cod and Maine
12z UMKET slowing down, but still heading toward Conus at 144.

12z Model Spread is widening again. System is weakening since this mornings huge convection and cloud tops at -86--88c. NHC calling it 7mph, but looks stationary over last 6 hrs. Oddly no 2pm advisory


12z euro 66/36 on 9/8
12z gfs 65/35 on 9/9
0z euro 67/35 on 9/8
0z GFS 63/24 on 9/3 and 63/33 on 9/9

fwiw, cmc has it breaking 70w at hr 144 around 34n (Crazy Uncle from the north -see below pic)
Hwrf an GFDS have it going fairly strait north with a few wobbles west. Hwrf goes towards Bermuda at the end of its run on the 13th, almost at 64/32. GFDL goes north along 33W to the end of its run on the 8th.

Convection is rather strong tonite too, center is under the convection but on the northern edge

9-1 - may not be as interesting as thought...
12z Euro 65/30 on 9/7 hits Bermuda, almost dead on
12z GFS 63/26 on 9/6 heads due north after
GFDL and HWRF are similar, but dont go out as far
Model spread is tighter than 8/31, but split between heading west or east of Bermuda, or looping around

0z GFS at 62/26 -well east of Bermuda
6z GFS at 60/26 - well east of Bermuda
0z Euro 64/26 -just east of Bermuda

While Leslie is still not a hurricane, she is much stronger and has a more organized appearance than Isaac did at this point. Weaker storms, as noted with Isaac, go further west and can miss troughs easier. Model spread shows storm slowing down and the models really have no idea after 72 hrs - some loop it around, some go west more go east. Leslie may be a hurricane later today. Shear looks to be a problem as the ADT has the center north of the main convection. NHC not intensifying much beyond 80 mph.


6z GFS goes to 70/35 and 69/40 - takes it into Maine

0z Euro at 68W34N on 9/8
0z GFS has it at 67W/36N and 66w/40n
GFDL at 63/25
Model spread is between Charleston and literally, Galway.

12z GFS takes it to 66/35, just west of Bermuda, hits Canada
12z Euro goes to 67/34, just west of the GFS, but sharply recurves


The 0z run of Euro has Leslie just to the SE of the benchmark on 9/8.
The 0z run of the GFS has Leslie at 55W 43N on 9/8
Model spread has it as far as 60W at 25N

12z Euro is at 67W/36 on 9/9
12z GFS has it at 61W/27N on 9/4

Saturday, August 18, 2012

This will wake you up

GFS has major hurricane (Isaac?) off Long Island on the first of Sept! Shades of last year!


Euro and GFS have a ridge in the Atlantic that is too strong for a system to hit directly from the Atlantic. Instead, they take Isaac into the Caribbean and around the ridge up into Florida or the Eastern Gulf. From there its possible to get up the seaboard. Keeping an eye out still. It hasn't developed yet and the stronger it gets the more likely it will head more north. Staying weak will push it further west.

8-21 update morning

The euro keeps it weak and passes over Jamaica befo it tightens up and hits the central gulf coast. GFS is just north of Jamaica, passes over Cuba, hits near the Keys, then again near S Carolina. These are the furthest south and west tracks. Gfs ensembles all take it up the east coast. Euro ensembles all through the Carribean. The hurricane models mostly take it near to the north or over Hispaniola, then up the East Coast. Cmc and ukmet are also tonthe right of the gfs. Right now the storm is starting to gain a Central dense overcast in the center, but remains a fast mover and subject to moderate shear. Once it slows down more, it should develop more. The earlier it does that, the further north it goes.


Isaac still hasn't wrapped itself up, despite its core staying away from land. Its weakness resulting in a further west movement. Also, the trough coming through the US, which seems so strong, has stalled in the southern half of the country. So, the Euro, per above, was correct so far in the end game. Todays run of the Euro is scary for NOLA. The storm intensifies as it nears, and stalls just to the east of Lake Pontchartrain, keeping northerly winds of at least 40mph driving water toward the city for about 48 hrs. The rains first arrive in NO at 12z Tuesday the 28th and continue until 6z on Friday. This would be extreme. Wind wise, just to the east of NO is hit rather hard with 36 hrs or longer of hurricane strength winds. Problem with the Euro model is that the wind chart maxes as 75kts and the rain chart maxes at 5inches. Both of these will be exceeded.
CMC follows the Euro, but not as strong
UKMET follows CMC- like Euro but weaker
NAM follows CMC, but doesnt go stronger than 996 and winds don't go above 45kts at the surface. Flight level winds never above 55kts.

GFS runs so far today track it southwest of NO, just over the delta. IT too slows the storm down as it reaches the coast. This puts NO in the windier section and storm surge from the gulf, which I trust more than a surge from LP (as in Katrina). GFS doesn't strengthen Isaac to a hurricane though.

HWRF takes it to 100kts, just to west of NOLA
GFDL takes it into E Texas, with 66kt being the top wind

Friday, August 3, 2012

New month, new storms

Per last post, Ernesto broke the shear and dry air, but struggles even today. But it looks the best it has all day right now. It should continue fairly week for another day or two. Models bring it to life once past Jamaica. I'm not thinking it hits the US as of now, but we'll see how the ridge holds out.

Then two more areas pop up - one near the Cape Verde islands, which is huge and strong. Long range models grab it then destroy it. One model taking it to the NE of the islands and recurving. Others devolve it into a wave. Right now there is an area of 20+kt sheer on its north side, displacing the divergence aloft. If it can shake that, there is a lot of energy to work with, moreso as it heads toward warmer water.

An area off Florida is where remnants of a tropical wave from last week and an old front have converged. Need to watch this interesting feature. Tstorms are plenty, its just whether they can spin up. The NAM does spin it into a low eventually and brings it into N Florida. Euro keeps it a wave. Its near an area of 20-30kt shear, but there a slot of no shear developing.