ATL: GABRIELLE - Remnants - Discussion

[cycloneye]

I might be wrong but looks like a Mid Level Circulation is forming around 15N-57W. The blob of convection to its east is the area to watch for a Mid Level Circulation center to try and stack up while the low level center has not moved much in the past few hours based on satellite.

This post is NOT AN OFFICIAL FORECAST and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org. For Official Information please refer to the NHC and NWS products.

[HurricaneDREW92]

I might be wrong but looks like a Mid Level Circulation is forming around 15N-57W. The blob of convection to its east is the area to watch for a Mid Level Circulation center to try and stack up while the low level center has not moved much in the past few hours based on satellite.

This post is NOT AN OFFICIAL FORECAST and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org. For Official Information please refer to the NHC and NWS products.

Was about to post the same thing
EDIT: Looks like the LLC & MLC are about 2 degrees apart.

[cycloneye]

This mornings discussion of 97L by Dr Jeff Masters.

A tropical wave over the Lesser Antilles Islands (Invest 97L) is moving westward at 15 mph, and is bringing heavy rains and gusty winds to the islands. Top sustained winds in the islands as of 10 am AST Sunday were 26 mph at Monserrat. Heavy thunderstorm activity has sharply increased since Saturday, as seen on satellite loops. A large circulation is evident, with some westerly winds blowing to the south of the disturbance. However, the thunderstorms are poorly organized, and there is no sign of a well-organized surface circulation. Martinique radar shows some rotation to the echoes, though well-organized spiral bands are not evident, and do not appear to be forming. Wind shear has dropped to a moderate 10 - 20 knots over the system. An area of dry air from the Saharan Air Layer (SAL) surrounds 97L and is interfering with development.

Forecast for 97L

Wind shear is expected to be in the low to moderate range for the next five days, and ocean temperatures will be warm, 28 - 29°C. The disturbance is steadily moistening the atmosphere and is moving into a moister environment, so dry air will be less of an impediment to development as the week progresses. The main factor keeping the disturbance from developing over the next two days would appear to be the fact that 97L is quite large, and is stretched out from east to west over a wide expanse. Large, elongated systems like 97L usually take several days to consolidate and spin up. Another factor that will likely retard development is the presence of strong surface trade winds over the Eastern Caribbean ahead of 97L, south of the Dominican Republic. These strong trade winds are a common feature of the Eastern Caribbean, and make the region something of a hurricane graveyard. As the surface wind flow to the west of 97L accelerates into this wind max, air will be sucked from aloft downward towards the surface, creating sinking air, interfering with the formation of thunderstorm updrafts. The best chance for development of 97L would appear to be on Wednesday or Thursday, when the disturbance reaches the Central Caribbean. The wave will likely spread heavy rains to Puerto Rico, the Virgin Islands, and the Dominican Republic by Tuesday, and to Haiti by Wednesday. These rains will be capable of causing life-threatening flash flooding and mudslides in mountainous regions in Puerto Rico and Hispaniola. Of our three reliable models for predicting genesis, the UKMET, GFS, and European models, only the UKMET model develops the disturbance, predicting it will become a tropical depression south of Haiti on Wednesday, and near Jamaica on Thursday

[HurricaneDREW92]

WARNING: TOTAL AMATEUR
6hrs: 30/40
12hrs: 30/50
18hrs: 30/50
24hrs: 40/70
36hrs: 60/80
48hrs: 80/90
60hrs: 40kts
72hrs: 45kts
96hrs: 60kts
120hrs: 70kts

[Blown Away]

Tracks of past systems near 97L's position...

[perk]

http://img42.imageshack.us/img42/8462/xvj8.jpg
Tracks of past systems near 97L's position...

That map really helped,give me a headache

[perk]

wxman57 we sure could use your thoughts on where 97L may be headed.

[tolakram]

Live visible: http://wwwghcc.msfc.nasa.gov/cgi-bin/get-goes?satellite=GOES-E%20HURRICANE&lat=15&lon=-61&info=vis&zoom=1&width=1000&height=800&type=Animation&quality=95&palette=ir1.pal&numframes=5

The UKMET predicted formation further south, and I had to lower this image from last night to center it on the convection. This may be why the NHC is thinking it may develop.



from: http://ruc.noaa.gov/hfip/tcgen/

[tolakram]

Shear is dropping slightly.



http://tropic.ssec.wisc.edu/real-time/windmain.php?&basin=atlantic&sat=wg8&prod=sht&zoom=&time=

[Dean4Storms]

Elongated systems like this will take days and favorable conditions to develop.

[cycloneye]

Air Force recon for Tuesday afternoon and Global Hawk mission for Tuesday morning

WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1100 AM EDT SUN 01 SEPTEMBER 2013
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 02/1100Z TO 03/1100Z SEPTEMBER 2013
TCPOD NUMBER.....13-092

I. ATLANTIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. OUTLOOK FOR SUCCEEDING DAY: POSSIBLE LOW-LEVEL INVEST OF
CENTRAL CARIBBEAN SYSTEM NEAR 15.0N 72.0W FOR 03/1800Z.
3. REMARK: THE NASA 871 GLOBAL HAWK MAY FLY A 24-HOUR RESEARCH
MISSION OVER THE CARIBBEAN SYSTEM...TAKING OFF AT
03/1100Z.

[Dave]

Thanks Cycloneye....my stomach was looking like that model map ^ there for the past 3 days but should be ready for part of the recon mission Tuesday if they go.

[Sanibel]

The elongated convection tells you the system looks good because of shear.


All a question of if the negative conditions are stronger than climatology further west. As usual I tend to side with development.


The inflow from the south quadrant looks stronger. That should be the subtle sign of a go.


Amateur opinion disclaimer.

[HurricaneDREW92]

Latest Saved Loop:



Uploaded with ImageShack.us

[Alyono]

WARNING: TOTAL AMATEUR
6hrs: 30/40
12hrs: 30/50
18hrs: 30/50
24hrs: 40/70
36hrs: 60/80
48hrs: 80/90
60hrs: 40kts
72hrs: 45kts
96hrs: 60kts
120hrs: 70kts

A question I have... why do people insist on only giving intensity forecasts? Why not stick with track where there is a higher level of skill? There is little, if any, skill in intensity forecasting for the pros. Just something to consider

[blp]

These observations point to a surface low around Barbados.

[perk]

WARNING: TOTAL AMATEUR
6hrs: 30/40
12hrs: 30/50
18hrs: 30/50
24hrs: 40/70
36hrs: 60/80
48hrs: 80/90
60hrs: 40kts
72hrs: 45kts
96hrs: 60kts
120hrs: 70kts

A question I have... why do people insist on only giving intensity forecasts? Why not stick with track where there is a higher level of skill? There is little, if any, skill in intensity forecasting for the pros. Just something to consider

I agree predicting intensity is problematic,but what are your thoughts on 97L's track.

[HurricaneDREW92]

WARNING: TOTAL AMATEUR
6hrs: 30/40
12hrs: 30/50
18hrs: 30/50
24hrs: 40/70
36hrs: 60/80
48hrs: 80/90
60hrs: 40kts
72hrs: 45kts
96hrs: 60kts
120hrs: 70kts

A question I have... why do people insist on only giving intensity forecasts? Why not stick with track where there is a higher level of skill? There is little, if any, skill in intensity forecasting for the pros. Just something to consider

I like to draw my tracks as I am a hands on person, but currently I am stuck with a laptop that doesn't have paint. My track is most similar to this one. Sorry bout the east coast thing last night.

What my general track for this system is like:



Uploaded with ImageShack.us

[wxman57]

Obs across Barbados, the southern Antilles and Tobago indicate an elongated (but present) LLC. I've been looking at upper-level flow projections of the GFS, Canadian and Euro and all are predicting a deepening trof across the Gulf of Mexico in 4-5 days, with moderate to strong WSW-W flow aloft across the southern Gulf. If those projections are correct, then I would expect that if it develops it will track toward Jamaica or a little north of there then turn north or NNE across Cuba. Possible threat to south Florida, but could turn north to the east of Florida.

[blp]

Still quite elongated but the increasing west winds in Barbados may indicate it is tightening up.

11:00 AM, Sun
W18mph
10:00 AM, Sun
W18mph
9:00 AM, Sun
W13mph


http://www.intellicast.com/Local/Observation.aspx?location=BBXX0001