ATL: INVEST 92L - Discussion

[jlauderdal]

12z Euro paints a very wet forecast for S FL over the next 36-48 hrs.

Local Met said that HPC had up to 8 inches through Sunday for SE Fla.

sw flow on the backside should be very favorable especially if we get some heating on sat and sun

[Bocadude85]

Anyone thinking this will be upgraded at 11 tonight given the proximity to land if it maintains steady convection until then?

Honestly I'd be surprised to see them upgrade this unless convection can really sustain itself.

[windnrain]

The convection is more than maintaining itself. On the 5 minute frame, it seems every single frame adds more and more.

http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... mframes=25

[gatorcane]

Anyone thinking this will be upgraded at 11 tonight given the proximity to land if it maintains steady convection until then?

Honestly I'd be surprised to see them upgrade this unless convection can really sustain itself.

If the convection keeps up like it is, maybe a special advisory before 11PM EST....

It probably is feeling those very warm Gulf stream waters. They can really fuel a system, despite a marginal environment.

[MississippiWx]

Florida is very lucky that shear is having its way with this system. Otherwise, it would be a rapidly intensifying system coming ashore.

[Sanibel]

Vertical wind shear from the NNE is keeping it in check.

[NDG]

Interesting that this is about the same spot Arthur started forming and was battling northerly UL shear.

[Bocadude85]

The convection is more than maintaining itself. On the 5 minute frame, it seems every single frame adds more and more.

http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... mframes=25

Well it's about 150 miles offshore so it doesn't have a lot of time to crank up.

[gatorcane]

The convection is more than maintaining itself. On the 5 minute frame, it seems every single frame adds more and more.

http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... mframes=25

Yep and right over or near the LLC too - I think it's really getting it's act together now. Shouldn't be too long before it is declared a TD.

[NDG]

Interesting that this is about the same spot Arthur started forming and was battling northerly UL shear.

[tolakram]

Has the plan of the day changed?

000
NOUS42 KNHC 102130
REPRPD
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
0530 PM EDT WED 10 SEPTEMBER 2014
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 11/1100Z TO 12/1100Z SEPTEMBER 2014
TCPOD NUMBER.....14-102 AMENDMENT

I. ATLANTIC REQUIREMENTS...ADDED
1. SUSPECT AREA (NEAR BAHAMAS)
FLIGHT ONE -- TEAL 71
A. 11/1730Z
B. AFXXX 01HHA INVEST
C. 11/1445Z
D. 27.0N 77.5W
E. 11/1700Z TO 11/2200Z
F. SFC TO 10,000FT

FLIGHT TWO - TEAL 72
A. 12/0530Z, 1130Z
B. AFXXX 0206A CYCLONE
C. 12/0215Z
D. 27.0N 78.5W
E. 12/0500Z TO 12/1130Z
F. SFC TO 10,000FT

2. OUTLOOK FOR SUCCEEDING DAY.....CONTINUE 6-HRLY
FIXES IF SYSTEM DEVELOPS AND REMAINS OFFSHORE.
3. REMARKS: NASA 872 RESEARCH FLIGHT AT 12/2200Z.

II. PACIFIC REQUIREMENTS...NO CHANGES
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. SUCCEEDING DAY OUTLOOK; FIX TROPICAL STORM ODILE
NEAR 15.9N 103.3W AT 12/1900Z.
$$
WJM

[jhpigott]

Has the plan of the day changed?


I. ATLANTIC REQUIREMENTS...ADDED
1. SUSPECT AREA (NEAR BAHAMAS)
FLIGHT ONE -- TEAL 71
A. 11/1730Z
B. AFXXX 01HHA INVEST
C. 11/1445Z
D. 27.0N 77.5W
E. 11/1700Z TO 11/2200Z
F. SFC TO 10,000FT



2. OUTLOOK FOR SUCCEEDING DAY.....CONTINUE 6-HRLY
FIXES IF SYSTEM DEVELOPS AND REMAINS OFFSHORE.

$$
WJM

Am I reading that right - they are flying over Bahamas system between 1700z and 2200z today?

[NDG]

Has the plan of the day changed?

000
NOUS42 KNHC 102130
REPRPD
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
0530 PM EDT WED 10 SEPTEMBER 2014
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 11/1100Z TO 12/1100Z SEPTEMBER 2014
TCPOD NUMBER.....14-102 AMENDMENT

I. ATLANTIC REQUIREMENTS...ADDED
1. SUSPECT AREA (NEAR BAHAMAS)
FLIGHT ONE -- TEAL 71
A. 11/1730Z
B. AFXXX 01HHA INVEST
C. 11/1445Z
D. 27.0N 77.5W
E. 11/1700Z TO 11/2200Z
F. SFC TO 10,000FT

FLIGHT TWO - TEAL 72
A. 12/0530Z, 1130Z
B. AFXXX 0206A CYCLONE
C. 12/0215Z
D. 27.0N 78.5W
E. 12/0500Z TO 12/1130Z
F. SFC TO 10,000FT

2. OUTLOOK FOR SUCCEEDING DAY.....CONTINUE 6-HRLY
FIXES IF SYSTEM DEVELOPS AND REMAINS OFFSHORE.
3. REMARKS: NASA 872 RESEARCH FLIGHT AT 12/2200Z.

II. PACIFIC REQUIREMENTS...NO CHANGES
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. SUCCEEDING DAY OUTLOOK; FIX TROPICAL STORM ODILE
NEAR 15.9N 103.3W AT 12/1900Z.
$$
WJM

It looks like yesterday's.

[USTropics]

Shear forecasts don't have the highest verification rate, but here is a look at the GFS 12z forecast in 48 hours. You can see the cold front draped through the GOM and across Florida inducing 15-20 knots of shear. You could see slow strengthening once it reaches the GOM, but that should put a damper on anything of significance forming.

http://i.imgur.com/1c7HXGn.png

Lol, that's not shear from a cold front, lol.

My fault, I saw the 48 hour CPC forecast that has the frontal boundary in the northern GOM and assumed that was it. And that's why I'm a programmer and not a forecaster lol. Regardless, the shear is still there, albeit from the cutoff ULL.

[Kohlecane]

http://www.nrlmry.navy.mil/nexsat-bin/n ... x.DAY.jpg&

If that shear were to let up you can see how much more larger this would be

[Nimbus]

Anyone thinking this will be upgraded at 11 tonight given the proximity to land if it maintains steady convection until then?

Honestly I'd be surprised to see them upgrade this unless convection can really sustain itself.

If the convection keeps up like it is, maybe a special advisory before 11PM EST....

It probably is feeling those very warm Gulf stream waters. They can really fuel a system, despite a marginal environment.

If they were going to announce tropical storm warnings 24 hrs before landfall could they wait till 11 PM?

[tailgater]

Anyone else thinking this thing might move WSW because of center reloc/shear keeping the south side of system stronger.

[gatorcane]

Plenty of west winds found. Here are the observations from settlement point...

2:00 pm SW ( 228 deg ) 11 kts
1:50 pm SW ( 230 deg ) 13 kts
1:40 pm WSW ( 255 deg ) 16 kts
1:30 pm W ( 270 deg ) 13 kts
1:20 pm WNW ( 286 deg ) 14 kts
1:10 pm WNW ( 298 deg ) 13 kts

[gatorcane]

Oh and the pressure is slowly dropping and winds slowly increasing as the area of low pressure nears:

[chaser1]

92L is in this year's "hot box"; the shear is obviously evident but a weak low exists and convection is persisting (at the moment). Will be curious to see if local ship & buoy reports indicate falling pressures. Looks to be as if the LLC could be trying to reform under the eastern edge of the convection. If vertically stacked, continued convection might well stave off 15 knot shear plus a 250 - 270 motion at about 5 knots certainly doesn't hurt in terms of decreasing the net shear impacting it.

Given the proximity to land, the potential for localized flooding, plus the weekend approaching... I'm going to guess that any increased organization or even an increase in convection might cause NHC to consider upgrading the system to a depression between late tonight & tomorrow a.m. Of ccourse it wouldn't be unreasonable for the convection to get sheared off during the next 6 hours but I'm hedging towards thinking this will be upgraded to a depression between 6-12 hours