ATL GUSTAV: Tropical Depression - Discussion

[Derek Ortt]

Well, perhaps we'll have a better idea of where it may form by tomorrow. Unfortunately, we have to issue 7-day tracks on such disturbances to our clients. I discussed with my on-duty forecaster the possibility of a forked track. One west, one turning north.

great, how about releasing that forked track for our reading pleasure

private forecasts costs a good deal of money

[wxman57]

That buoy up at 15N/67.5W sure doesn't point to a center reformation beneath the blob north of the buoy. Wind ENE at 20 kts with a pressure 1010.1mb at 00Z (up from 1009.6mb at 23Z).

Here's a 00Z plot with the MLC identified by the crosshairs near 13.7N/68W. A 23Z plot showed ENE winds around 10 kts across the ABC Islands. No evidence of an LLC.

[RL3AO]

Usually when you get that kind of wording in the TWO, the NHC has the development chances above 50%, but not this time.

[drezee]

Buoy 42059
Highest 1 minute Wind Speed
Time (GMT) WSPD WDIR
2153 36.1 kts E ( 80 deg true )

[KWT]

Willing to bet that comes pretty soon RL3AO, can't imagine them not upgrading the threat to red given that wording.

[Sanibel]

Shortwave has a persisting center near 13.5-67

No relocation to the 15.5 burst yet, if at all.

Agree with that center for now wx57. (Further west)

Looking more GFDL by the moment.

[KWT]

Yeah its pretty clear that center further south is the dominant one, heading around 285 I think. The models still seem to be gaining too much latitude but at leas the new GFDL does seem to match up with the current foward speed a little better then some. I'd have thought it will slow a little bit once this reaches 75W.

[Blown Away]

Jeff Master's on Disturbance 94L in the eastern Caribbean
Heavy thunderstorms associated with a tropical wave (94L) near 12N, 65W, in the eastern Caribbean, have grown more widespread over the past day. This morning's QuikSCAT pass missed 94L, but did show sustained winds of 40 mph north of the center. Visible satellite loops show evidence of rotation in the clouds at middle levels of the atmosphere, but no surface circulation as yet. The area covered by the heaviest thunderstorms is relatively modest. The storm has moistened its environment considerably, and dry air should be less and less of a problem for the storm over the next few days. Wind shear has fallen to a modest 10 knots over 94L and is decreasing. NHC is giving this system a medium (20%-50% chance) of developing into a tropical depression by Tuesday afternoon, and has scheduled a Hurricane Hunter flight to investigate on Monday afternoon.

The forecast for 94L
The models have had a tough time properly handling 94L, and have not been making believable forecasts of the storm's track and speed. The latest (8 am EDT Sunday) GFDL forecast appears to have the most believable forecast I've seen, developing 94L into a tropical storm that tracks over extreme Southwest Haiti, then into the region between Jamaica and Cuba. The NOGAPS and ECMWF models have also been developing 94L with each run the past few days. Heavy rain and high winds from 94L's circulation should affect Haiti's southern Peninsula on Tuesday morning, and spread to Jamaica and eastern Cuba by Tuesday night. The wind shear forecast for the Caribbean calls for very low values of wind shear around 5 knots for most of the coming week. Residents of Haiti, Jamaica, and Cuba should keep a careful eye on this potentially dangerous disturbance. I expect 94L will be a tropical depression by Tuesday, and will eventually grow into a tropical storm or hurricane that will threaten Cuba, the U.S., and/or the Bahama Islands late this week.

[cycloneye]

Peeps,look at the long range radar of San Juan.It looks like Puerto Rico may get a big band of rain.

http://radar.weather.gov/radar.php?rid= ... 1&loop=yes

[SouthFLTropics]

I expect 94L will be a tropical depression by Tuesday, and will eventually grow into a tropical storm or hurricane that will threaten Cuba, the U.S., and/or the Bahama Islands late this week.

Well, that's a bit concerning...It throws us here in FLA right in the middle of that mix.

SFT

[Clipper96]

That buoy up at 15N/67.5W sure doesn't point to a center reformation beneath the blob north of the buoy. Wind ENE at 20 kts with a pressure 1010.1mb at 00Z (up from 1009.6mb at 23Z).

Good. I knew my eyes weren't lying to me.

Tops are warming in the northern part of the band while convection is getting more intense in the western part where it circles in.

http://www.ssd.noaa.gov/goes/flt/t2/loop-avn.html

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Unofficial prediction: This messy-looking business should continue for several hours, until an intense burst mushrooms over the LLC toward dmax. TD by 11am Monday, TS by 5pm or 11pm, Hurr1 on Tuesday morning, with rapid intensification to cat-4 south then west of Jamaica after that.

[Sihara]

Peeps,look at the long range radar of San Juan.It looks like Puerto Rico may get a big band of rain.

http://radar.weather.gov/radar.php?rid= ... 1&loop=yes

Sure looks like a real soaker is headed your way! Didn't I read somewhere (caribbean site?) that it's due to a tropical wave in the vicinity?

[jaxfladude]

Yikes!!!
Poof/Storm Cancel anyone???

[cycloneye]

00:00 UTC Best Track:

AL, 94, 2008082500, , BEST, 0, 135N, 677W, 25, 1008, LO,

[AtlanticWind]

I really see a possible RI when this system gets a little further Northwest under Haiti , conditions seem favorable and the water temps ramp up over the nw carribean.

[Sanibel]

I really see a possible RI when this system gets a little further Northwest under Haiti , conditions seem favorable and the water temps ramp up over the nw carribean.

I would temper that since Fay transited the same waters without any intensification. 94L is also having trouble getting a center together so the same conditions could be at play.

[AtlanticWind]

I really see a possible RI when this system gets a little further Northwest under Haiti , conditions seem favorable and the water temps ramp up over the nw carribean.

I would temper that since Fay transited the same waters without any intensification. 94L is also having trouble getting a center together so the same conditions could be at play.

True , but fay had a lot of land interaction , I think it to could have a been at least a cat 3 if not for this.

[CalmBeforeStorm]

I really see a possible RI when this system gets a little further Northwest under Haiti , conditions seem favorable and the water temps ramp up over the nw carribean.

I would temper that since Fay transited the same waters without any intensification. 94L is also having trouble getting a center together so the same conditions could be at play.

Fay had just gone over the entire Dominican Republic and had little time to get it's structure back before going over Cuba and Florida. This system figures to have very little land interaction foir awhile.

[Derek Ortt]

one thing we do need... as of 2100 UTC the low level convergence was not very good at all.

Remember that with Fay and Dolly (the last 94L)... we did not see development until the low level convergence became well-established

[Sanibel]

Fay had just gone over the entire Dominican Republic and had little time to get it's structure back before going over Cuba and Florida. This system figures to have very little land interaction foir awhile.

Uncertain.

A good comparison would be Dean and Felix that tracked across the same area with much better organization by this point. Fay had plenty of prime waters to rebound and didn't. I expect hurricane from this if it stays overwater. Right outliers are busting right now.