INVEST 93L Comments Thread #1

[gatorcane]

Latest TWO

A WESTWARD-MOVING TROPICAL WAVE WILL BE MOVING ACROSS THE LESSER
ANTILLES TODAY...BRINGING INCREASED SHOWERS AND BRIEF PERIODS OF
GUSTY WINDS TO THOSE ISLANDS THROUGH TONIGHT. HOWEVER...STRONG
UPPER-LEVEL WINDS ARE EXPECTED TO PROHIBIT DEVELOPMENT OF THIS
SYSTEM DURING THE NEXT DAY OR SO.

To me this implies after a day or so, conditions will become more favorable. What do you all think?

[Dean4Storms]

It certainly won't develop any further with all the shear it is now running into. But once it gets into the central Carib. and westward it will have more favorable environment and will have to be watched. Had this sytem slowed down I think we would have seen a TC already. Still it is a fairly ominous sign that we have this strong a TW staying pretty much convective all the way across the Atlantic in June.

[Tampa_God]

To me this implies after a day or so, conditions will become more favorable. What do you all think?

[cheezyWXguy]

wow...this is pretty crazy...i know this doesnt have anything to do with 93L but it appears we have something new to watch as well...

from the 1130 TWO:
A BROAD AND DISORGANIZED AREA OF SHOWERS AND THUNDERSTORMS IS
LOCATED BETWEEN BERMUDA AND PUERTO RICO. THIS ACTIVITY IS
ASSOCIATED WITH A SURFACE TROUGH AND AN UPPER-LEVEL LOW.
SIGNIFICANT DEVELOPMENT OF THIS SYSTEM IS NOT ANTICIPATED DURING
THE NEXT DAY OR SO AS IT MOVES NORTHWESTWARD AT 10 TO 15 MPH.

[Tampa_God]

wow...this is pretty crazy...i know this doesnt have anything to do with 93L but it appears we have something new to watch as well...

from the 1130 TWO:
A BROAD AND DISORGANIZED AREA OF SHOWERS AND THUNDERSTORMS IS
LOCATED BETWEEN BERMUDA AND PUERTO RICO. THIS ACTIVITY IS
ASSOCIATED WITH A SURFACE TROUGH AND AN UPPER-LEVEL LOW.
SIGNIFICANT DEVELOPMENT OF THIS SYSTEM IS NOT ANTICIPATED DURING
THE NEXT DAY OR SO AS IT MOVES NORTHWESTWARD AT 10 TO 15 MPH.

I have been watching that too, but I don't believe anything will form. The whole thing is a mess.

[abajan]

Latest TWO

A WESTWARD-MOVING TROPICAL WAVE WILL BE MOVING ACROSS THE LESSER
ANTILLES TODAY...BRINGING INCREASED SHOWERS AND BRIEF PERIODS OF
GUSTY WINDS TO THOSE ISLANDS THROUGH TONIGHT. HOWEVER...STRONG
UPPER-LEVEL WINDS ARE EXPECTED TO PROHIBIT DEVELOPMENT OF THIS
SYSTEM DURING THE NEXT DAY OR SO.

To me this implies after a day or so, conditions will become more favorable. What do you all think?

It certainly seems to imply that.

After monitoring TWOs over a period of years, one learns to "read between the lines", so to speak.

We've already had some showers this morning here in Barbados and judging from the satellite pix, we're in for quite a bit more. BTW, it's somewhat gusty with windspeeds gradually increasing. Nothing alarming, though.

http://weather.noaa.gov/weather/current/TBPB.html

[Regit]

Latest TWO

A WESTWARD-MOVING TROPICAL WAVE WILL BE MOVING ACROSS THE LESSER
ANTILLES TODAY...BRINGING INCREASED SHOWERS AND BRIEF PERIODS OF
GUSTY WINDS TO THOSE ISLANDS THROUGH TONIGHT. HOWEVER...STRONG
UPPER-LEVEL WINDS ARE EXPECTED TO PROHIBIT DEVELOPMENT OF THIS
SYSTEM DURING THE NEXT DAY OR SO.

To me this implies after a day or so, conditions will become more favorable. What do you all think?

It certainly seems to imply that.

After monitoring TWOs over a period of years, one learns to "read between the lines", so to speak.

We've already had some showers this morning here in Barbados and judging from the satellite pix, we're in for quite a bit more. BTW, it's somewhat gusty with windspeeds gradually increasing. Nothing alarming, though.

http://weather.noaa.gov/weather/current/TBPB.html

Though it could also mean that it's too difficult to forecast shear to say anything about more than the next day or so. Saying that convection will persist and the wave is doomed could end up making them look silly if things change, even though that may be what they actually believe.

[clfenwi]

Latest TWO

A WESTWARD-MOVING TROPICAL WAVE WILL BE MOVING ACROSS THE LESSER
ANTILLES TODAY...BRINGING INCREASED SHOWERS AND BRIEF PERIODS OF
GUSTY WINDS TO THOSE ISLANDS THROUGH TONIGHT. HOWEVER...STRONG
UPPER-LEVEL WINDS ARE EXPECTED TO PROHIBIT DEVELOPMENT OF THIS
SYSTEM DURING THE NEXT DAY OR SO.

To me this implies after a day or so, conditions will become more favorable. What do you all think?

I think you are reading too much into it. The TWO is only supposed to cover 48 hours, not beyond.

The use of "the next day or so" seems to be a Knabb -ism. For example, his TWO back on the 17th said

A TROPICAL WAVE IS PRODUCING DISORGANIZED CLOUDINESS AND SHOWERS
EXTENDING NORTHEASTWARD FROM THE LEEWARD ISLANDS FOR A FEW HUNDRED
MILES. THE SHOWER ACTIVITY HAS DECREASED SOMEWHAT THIS
AFTERNOON... AND DUE TO STRONG UPPER-LEVEL WINDS... SIGNIFICANT
DEVELOPMENT OF THIS SYSTEM IS NOT EXPECTED DURING THE NEXT DAY OR
TWO AS IT MOVES NORTHWESTWARD AT 10 TO 15 MPH.

which, as in the current case could have been interpreted to mean that significant development was expected afterwards. However, that would have been a misinterpretation.

Reading through our little TWO archive, the other forecasters seem to be less open-ended, they'll simply say 'development is not expected' .

[gatorcane]

Latest TWO

A WESTWARD-MOVING TROPICAL WAVE WILL BE MOVING ACROSS THE LESSER
ANTILLES TODAY...BRINGING INCREASED SHOWERS AND BRIEF PERIODS OF
GUSTY WINDS TO THOSE ISLANDS THROUGH TONIGHT. HOWEVER...STRONG
UPPER-LEVEL WINDS ARE EXPECTED TO PROHIBIT DEVELOPMENT OF THIS
SYSTEM DURING THE NEXT DAY OR SO.

To me this implies after a day or so, conditions will become more favorable. What do you all think?

I think you are reading too much into it. The TWO is only supposed to cover 48 hours, not beyond.

The use of "the next day or so" seems to be a Knabb -ism. For example, his TWO back on the 17th said

A TROPICAL WAVE IS PRODUCING DISORGANIZED CLOUDINESS AND SHOWERS
EXTENDING NORTHEASTWARD FROM THE LEEWARD ISLANDS FOR A FEW HUNDRED
MILES. THE SHOWER ACTIVITY HAS DECREASED SOMEWHAT THIS
AFTERNOON... AND DUE TO STRONG UPPER-LEVEL WINDS... SIGNIFICANT
DEVELOPMENT OF THIS SYSTEM IS NOT EXPECTED DURING THE NEXT DAY OR
TWO AS IT MOVES NORTHWESTWARD AT 10 TO 15 MPH.

which, as in the current case could have been interpreted to mean that significant development was expected afterwards. However, that would have been a misinterpretation.

Reading through our little TWO archive, the other forecasters seem to be less open-ended, they'll simply say 'development is not expected' .

Interesting - thanks. To me they should say development is not expected in the next 48 hours or 2 days OR leave it open-ended (which implies a 48 hour bound). So why say over the next day or so since it leaves considerable doubt? I assume that is why the other forecasters leave it open-ended...

[gatorcane]

actually I think "the one day or so" means there is a possibility of something developing at any time but not likely - even when this system was out in the far Atlantic the thinking was the same - so it is very "safe" wording.

[cheezyWXguy]

I think this thing may have a chance to redevelop once it makes it to the same longtude as Puerto Rico because thats where the strong SW Flow ends...It should make it there in the next 24-36 hours...it apperas then that conditions will be more conductive for development...someone earlier in this thread said that this storm could take the same track as emily...I hoping its slightly north of there so us here in texas can get a least a chance at some nice, soaking rains...

Look at this loop and put it on a higher speed and its very easy to see the SW flow
http://www.ssd.noaa.gov/goes/flt/t2/loop-vis.html

[SouthFloridawx]

http://www.nrlmry.navy.mil/tc_pages/tc0 ... atest.html

Not doing too bad being under 15-25kts of shear currently. We'll see what happens when it moves into the 30+ kts of shear during the next 24 hours.

GFS indication that the shear will relax 36-48 hours from now but, it seems as though it is moving so fast it probably will not be there by the time the shear relaxes.

This is the latest GFS run for wind shear 200-850mb.
http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... =Animation

[cheezyWXguy]

heres the shear forecast thru 72 hours off of wunderground .com
http://www.wunderground.com/data/640x480/atlm_shear.gif

[curtadams]

heres the shear forecast thru 72 hours off of wunderground .com
http://www.wunderground.com/data/640x480/atlm_shear.gif

That's a bad color scheme for developing tropical cylones. Anything over 40 knots (about 21 m/s) is basically no chance for development. It should be compressed into about half that scale.

[no advance]

Looks like a little spin headed for Grenada. The TW is persistant. No doubt it is an inverted trough. I have seen this the past few yrs. Develpment looks possible down the line.

[jabber]

Just looked at a vis loop, I would bet this thing would be going if not for the shear from the sw. good looking wave.

[wxman57]

It certainly won't develop any further with all the shear it is now running into. But once it gets into the central Carib. and westward it will have more favorable environment and will have to be watched. Had this sytem slowed down I think we would have seen a TC already. Still it is a fairly ominous sign that we have this strong a TW staying pretty much convective all the way across the Atlantic in June.

Not just the shear, but the low-level wind flow across the Caribbean Sea is forecast to be 35-40 kts south of the DR and Jamaica over the weekend (5000 ft winds). It'll be hard to generate any convergence as it zips westward in the strong low-level winds. Maybe when it slows down by the southern Yucatan in 5-6 days. By then, though high pressure over the Gulf should keep it moving westward.

Here's an 850mb (low level - 5000 ft) wind flow chart. Note the strong easterly winds in advance of the wave. It should accelerate westward over the next few days, not slowing down until it's southwest of Jamaica approaching Nicaragua.

http://myweb.cableone.net/nolasue/850mb.gif

[gatorcane]

It certainly won't develop any further with all the shear it is now running into. But once it gets into the central Carib. and westward it will have more favorable environment and will have to be watched. Had this sytem slowed down I think we would have seen a TC already. Still it is a fairly ominous sign that we have this strong a TW staying pretty much convective all the way across the Atlantic in June.

Not just the shear, but the low-level wind flow across the Caribbean Sea is forecast to be 35-40 kts south of the DR and Jamaica over the weekend (5000 ft winds). It'll be hard to generate any convergence as it zips westward in the strong low-level winds. Maybe when it slows down by the southern Yucatan in 5-6 days. By then, though high pressure over the Gulf should keep it moving westward.

there still is a circulation visible on sat pics...it will be passing inbetween Grenada and St. Vincent it looks like -

look carefully and you will see the spin -

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

[wxman57]

It certainly won't develop any further with all the shear it is now running into. But once it gets into the central Carib. and westward it will have more favorable environment and will have to be watched. Had this sytem slowed down I think we would have seen a TC already. Still it is a fairly ominous sign that we have this strong a TW staying pretty much convective all the way across the Atlantic in June.

Not just the shear, but the low-level wind flow across the Caribbean Sea is forecast to be 35-40 kts south of the DR and Jamaica over the weekend (5000 ft winds). It'll be hard to generate any convergence as it zips westward in the strong low-level winds. Maybe when it slows down by the southern Yucatan in 5-6 days. By then, though high pressure over the Gulf should keep it moving westward.

there still is a circulation visible on sat pics...it will be passing inbetween Grenada and St. Vincent it looks like -

look carefully and you will see the spin -

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

Such a tiny eddy is quite meaningless. It's just a tropical wave racing along in the low-level flow. No development is likely for the next 3-4 days since it'll be accelerating. Without convergence, the thunderstorms will diminish.

[HurricaneHunter914]

Yet this is a very persistent Invest despite the shear. Something is telling me that this could be something interesting along the road.