ATL: TROPICAL STORM BILL (03L)

[gatorcane]

12Z ECMWF is a best case scenario missing everybody -- I'm hoping that verifies.

[cycloneye]

18 UTC BAM Models,SHIP intensity reaches 98kts

049
WHXX01 KWBC 131901
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1901 UTC THU AUG 13 2009

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

ATLANTIC OBJECTIVE AIDS FOR

DISTURBANCE INVEST (AL902009) 20090813 1800 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
090813 1800 090814 0600 090814 1800 090815 0600

LAT LON LAT LON LAT LON LAT LON
BAMS 11.7N 23.3W 12.5N 26.1W 13.0N 29.7W 13.1N 33.5W
BAMD 11.7N 23.3W 12.0N 25.9W 12.0N 28.7W 11.8N 31.5W
BAMM 11.7N 23.3W 12.1N 25.9W 12.5N 29.0W 12.6N 32.2W
LBAR 11.7N 23.3W 11.9N 25.5W 12.2N 28.5W 12.5N 31.7W
SHIP 25KTS 29KTS 37KTS 48KTS
DSHP 25KTS 29KTS 37KTS 48KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
090815 1800 090816 1800 090817 1800 090818 1800

LAT LON LAT LON LAT LON LAT LON
BAMS 12.9N 38.0W 12.1N 46.9W 10.8N 54.5W 9.5N 60.1W
BAMD 11.9N 34.5W 12.4N 41.1W 13.2N 47.3W 14.4N 52.8W
BAMM 12.7N 35.9W 12.4N 43.7W 11.5N 49.5W 12.5N 52.5W
LBAR 12.7N 35.6W 13.2N 44.1W 13.2N 48.0W .0N .0W
SHIP 60KTS 79KTS 89KTS 98KTS
DSHP 60KTS 79KTS 89KTS 98KTS

...INITIAL CONDITIONS...
LATCUR = 11.7N LONCUR = 23.3W DIRCUR = 280DEG SPDCUR = 7KT
LATM12 = 11.5N LONM12 = 21.9W DIRM12 = 278DEG SPDM12 = 7KT
LATM24 = 11.2N LONM24 = 20.3W
WNDCUR = 25KT RMAXWD = 60NM WNDM12 = 25KT
CENPRS = 1009MB OUTPRS = 1012MB OUTRAD = 180NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

[KWT]

Its not got great convection Frank but it does have a pretty decent circulation which is pretty large and broad. Besides its on red alert now so it must be getting closer.

[Derek Ortt]

it is a big difference being 46W vs 42W. Thats about 260NM and may make all the difference regarding recurvature or not

typically, the global models are far too slow in this part of the MDR

[Hurricaneman]

18 UTC Best Track.

AL, 90, 2009081318, , BEST, 0, 117N, 233W, 25, 1009, DB

if you go off of that, its headed just a tad bit north of due west

[wxman57]

that's the way to forecast... 40 years ago.
You cannot make a forecast off of historical tracks. You can only use the CURRENT synoptics/models as those affect the CURRENT storm

True, but climatology can be used as a guideline to what is more likely to happen (or not happen). If an event hasn't happened in 158 years of data, it doesn't mean it can't happen, but it does mean that it's not as likely to happen as some other track. Current model guidance is right in line with climatology - split between a U.S. East Coast threat (after the NE Caribbean) or out to sea once past the NE Caribbean.

[Gustywind]

The code red is the right one there Gustywind, I'm guessing they didn't have that information when they published that outlook!

UKMO also going for a powerful hurricane striking NE Caribbean, models are clustering on either a close shave or a direct hit it seems tonight.

Tkanks agree with you, you're right.

[Stormhunter27]

Except maybe Newfoundland. I intercepted Noel in Nova Scotia and despite the fact that it had weakened substantially, it still hit the coast with giant waves.

Mind you, Newfoundland is pretty well built and the structures (and people) can take some pretty good hits.

Still, I'm not yet convinced of the recurve up the coast with a miss. However, I've noticed that models seem to be trending towards a hit on Puerto Rico and then a run up the coast. Mind you, the GFs is still at 240 hours out in that forecast and I don't like to look at anything over 120 hours.

[wxman57]

Here's a recent surface plot/satellite. Convection is increasing near the center now. Should be upgraded to a depression tonight or tomorrow morning.

[Frank2]

wxman57,

Yes, it does seem that way, since the weakness in the ridge is forecast to be north of Puerto Rico at that time (per the GFS)...

Ugh - this time of year gives me a headache...

LOL

P.S. I see a dust outbreak to the north of the system - we'll see what that does to it...

[KWT]

True Derek I suppose, esp given the weakness is around 45-50W as well so small differences are quite important.

Except from the ECM nearly every model is either gunning for a NE Caribbean hit or something that comes too close for comfort.

[Derek Ortt]

that's the way to forecast... 40 years ago.
You cannot make a forecast off of historical tracks. You can only use the CURRENT synoptics/models as those affect the CURRENT storm

True, but climatology can be used as a guideline to what is more likely to happen (or not happen). If an event hasn't happened in 158 years of data, it doesn't mean it can't happen, but it does mean that it's not as likely to happen as some other track. Current model guidance is right in line with climatology - split between a U.S. East Coast threat (after the NE Caribbean) or out to sea once past the NE Caribbean.

I agree with that. I am not ready to abandon my forecast from yesterday of a Carib strike yet. There is an UL near 46W that formed during the last 24 hours. However, the latest WV images show it may be starting to lift ever so slightly. For this reason, and the ECs apparent slow bias for this storm, is why I am discounting the recurve at 60W

[KWT]

True Frank and I did have a question about the code red myself but looking at Wxman57's image you can see 90L is starting to form some convection near the center.

As for track, NE Caribbean is the biggest risk, beyond that and I've not a clue though I'd imagine recurve has to be the most likely option from there...though Hugo proved it can happen differently.

[S.FLA STORM TRACKER]

Hello eveyone,

S2K is the best, been around for 3yr's. But never posted I have seen a lot of knowledge from the pro's and the joe's ( Amateurs ) and learned a lot. But can't help geting a bit confused. I understand about the highs, weakness in the ridge and all. But seems all though very far out, models are trending recurve. Derek had mentioned earlier that the stronger the storm it can cause the ridge to become stronger, keeping it on a more wnw track. The models seem sure of a strong storm, so why the recurve?

[Derek Ortt]

Hello eveyone,

S2K is the best, been around for 3yr's. But never posted I have seen a lot of knowledge from the pro's and the joe's ( Amateurs ) and learned a lot. But can't help geting a bit confused. I understand about the highs, weakness in the ridge and all. But seems all though very far out, models are trending recurve. Derek had mentioned earlier that the stronger the storm it can cause the ridge to become stronger, keeping it on a more wnw track. The models seem sure of a strong storm, so why the recurve?

you misunderstood what I said

I said if there is a deep layer ridge, a stronger storm will go farther west than a weaker storm

[Brent]

Here's a recent surface plot/satellite. Convection is increasing near the center now. Should be upgraded to a depression tonight or tomorrow morning.

Agree, looking much better.

[wxman57]

I agree with that. I am not ready to abandon my forecast from yesterday of a Carib strike yet. There is an UL near 46W that formed during the last 24 hours. However, the latest WV images show it may be starting to lift ever so slightly. For this reason, and the ECs apparent slow bias for this storm, is why I am discounting the recurve at 60W

Yes, the EC's timing of the ridge/trof axes to the north is quite different from the GFS. New EC is considerably closer to New England, though, at 10 days. All models forecast a trof/front along the East U.S. Coast around the weekend of the 22-23. Timing will be the key. If the storm slows or the front speeds up, then it could be blocked and miss the northerly turn. Or if the front speeds up and the storm is far enough north, it may take the turn north between 60-70W. I'll let you know my high-confidence forecast in about a week.

I think a NE Caribbean hit is a very good possibility (Luis). Next week will be quite interesting.

[S.FLA STORM TRACKER]

Got you thanks Derek.

[Steve H.]

Yes. a deep layer ridge would steer a storm further west, like a faster spinning top would go farther down a stringline. I think you can throw out this Euro run though; seems to be kicking it out too soon. Things upstream will change for the next week.

[KWT]

Yep can see the ULL is starting to lift out already to the ENE as Derek mentioned:

http://www.ssd.noaa.gov/goes/east/catl/loop-wv.html

As for the chance of a Luis type threat, that does need to be closely watched, same with a Hugo type strike...