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98L may develop next week; 97L not a threat to land

By: Dr. Jeff Masters, 1:59 PM GMT on October 09, 2012

A tropical wave located about 1000 miles east of the Lesser Antilles Islands (Invest 98L) has a large amount of disorganized heavy thunderstorms, and is headed west-northwest at about 15 mph. Wind shear is a light to moderate 5 - 15 knots over 98L, the atmosphere is moist, and ocean temperatures are a very warm 29°C. With wind shear expected to remain in the moderate range through Wednesday morning, some slow development is likely until 98L encounters much higher wind shear of 20 - 35 knots Wednesday night though Friday. This shear will be due to an upper-level trough of low pressure centered a few hundred miles northeast of the Lesser Antilles Islands. Moisture from 98L could arrive in the Lesser Antilles Islands as early as Thursday night. Wind shear may drop to levels capable of allowing 98L to develop into a tropical depression by Saturday, as predicted by the NOGAPS model. The GFS model predicts shear will remain high until early next week. The GFS develops 98L into a tropical depression on Tuesday, a few hundred miles northeast of the northernmost Lesser Antilles Islands. In their 8 am Tropical Weather Outlook, NHC gave 98L a 20% chance of becoming a tropical cyclone by Thursday morning. The long range fate of 98L is uncertain; the ECMWF model shows 98L coming close to the U.S. East Coast in ten or so days, while the other models keep 98L far out to sea.


Figure 1. Morning satellite image of Invest 98L headed towards the Lesser Antilles Islands.

97L near the Bahamas little threat to develop
A tropical disturbance a few hundred miles northeast of the Bahama Islands (Invest 97L) has a moderate amount of disorganized heavy thunderstorms, and is headed northeast at about 10 mph. Satellite loops show that heavy showers from 97L are affecting portions of the Southeast Bahama Islands, and this activity will continue today. Wind shear is a moderate 15 - 20 knots over 97L, but is expected to rise to the high range, 20 - 30 knots, on Tuesday night. This high shear should prevent 97L from developing as it heads northeastwards out to sea. In their 8 am Tropical Weather Outlook, NHC gave 97L a 10% chance of becoming a tropical cyclone by Thursday morning. Rains from 97L will not affect the U.S.

Jeff Masters

Hurricane

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Thanks, Doc. Anything about the disturbance in the Caribbean.
Thanks Doc!
98 still alot of unknowns thanks
Dr Masters, I noticed you've brought the shear for 98L down from 20-40kts(from last blog) to 20-30kts. Any reason? Is this shear drop going to continue?

Thanks for the updates on 97L and 98L.
98L

Night IR to Vis Loop



sw carib. is like a new girl at the bar take some time to scope out. red bull is covering felix:s jump from space.
Quite an impressive pulse here. As Aussie pointed out earlier, we can easily see another 2 or perhaps even 3 systems out of this in the Atlantic Basin. Couple that with favorable conditions and still within the Aug 20th - Oct 20th peak and we could be looking at trouble a-brewin' within the upcoming couple weeks.



But first, we have this to watch...

98L

Thank you Dr. Masters
Quoting PalmBeachWeather:
Thank you Dr. Masters

Are you guys finally drying out down there. You had some pretty hefty rainfalls the past week or so haven't you??
98L is at 9N trucking at 24mph straight west. It will be difficult to go north of the islands if this maintains.
Quoting CybrTeddy:
98L is at 9N trucking at 24mph straight west. It will be difficult to go north of the islands if this maintains.
agreed
Other than the Upper Great Lakes and Cape Cod Regions where the 12Z NAM is depicting some decent rainfall totals, the rest of the conterminous U.S. looks fairly dry for the next 24 hours.

Quoting CybrTeddy:
98L is at 9N trucking at 24mph straight west. It will be difficult to go north of the islands if this maintains.
If it stays weak and disorganized then it will probably take the southern route or the east to west zonal flow, but if it gains strength it may be able to feel the weakness in the ridge which is displaced to the north.

Thanks Doc !!!

Lots and lots of blobs ... ok 2 are invests but the blob in the west Caribbean might be needed to be watched

Flash embedded

Link
Quoting TomballTXPride:
Other than the Upper Great Lakes and Cape Cod Regions where the 12Z NAM is depicting some decent rainfall totals, the rest of the conterminous U.S. looks fairly dry for the next 24 hours.



Slightly different.



next 5 days...


Nice rain coverage.
.."Upon us all, all, a lil rain must fall"...
Quoting Patrap:
.."Upon us all, all, a lil rain must fall"...

and looking at the next 5 days, only the SE US will miss out, except for souther Florida still.
WPB!:)
Thanks Doc! And they say the tropics are boring and are going to shut down soon...
Friday!!!:) Mostly sunny, with a high near 85. Breezy, with a northeast wind 9 to 16 mph, with gusts as high as 21 mph.
Quoting SFLWeatherman:
WPB!:)
This morning was cool along the West Coast of FL. Expected to get morning lows in the Upper 60s on Wed. and Thurs.

And upper 50s north and in our normally cooler spots away from the water.

Quoting Grothar:
Thanks, Doc. Anything about the disturbance in the Caribbean.

Apparently it doesn't qualify as being a disturbance.

I suspect that an outbreak of Blob Fever is about to happen
Thanks for the update Dr. Masters. Any thoughts on the blob south of Jamacia?
Quoting bappit:

Apparently it doesn't qualify as being a disturbance.



Well I'm disturbed about it.
Quoting Grothar:


Well I'm disturbed about it.


Me too Grothar. Me too.
Pacific eases further away from El Nio thresholds

The chance of El Nio developing in 2012 has reduced over the past fortnight. The tropical Pacific continued its retreat from El Nio thresholds for the second consecutive fortnight (i.e., ocean temperatures cooled), remaining within the neutral range (neither El Nio nor La Nia). Other ENSO indicators such as the Southern Oscillation Index (SOI) and tropical cloud patterns have persisted at neutral levels since late July.

Given the rate of ocean cooling, and the continued neutral conditions in the atmosphere, the chance of an El Nio developing in 2012 has reduced further over the past fortnight. However, some risk still remains while the trade winds in the western Pacific continue to be weaker than normal. Climate models surveyed by the Bureau of Meteorology have increased their chances of sea surface temperatures in the tropical Pacific Ocean remaining at neutral levels, though still warmer than average, for the remainder of 2012.

The Indian Ocean Dipole (IOD) is likely to return to neutral values during the latter half of the southern spring, according to outlooks from the Bureau%u2019s climate model. The IOD index has been consistently above 0.4 C since mid-July, indicative of a positive IOD event. A positive IOD is typically associated with decreased winter and spring rainfall over parts of southern, central and northern Australia.











Looking downstream,,the thingee in the Caribbean has about a 0% chance of developing as the CONUS fronts are in Shields up Mode Cpt'n.


Here in NJ, we are already pretty worried about 98L.
12Z NAM

Interestingly, Hurricane OMAR in 2008 began as INVEST 98L lol. It crossed the NE Carib on october 15th - 16th
Caribbean water vapor Image

remember 95? http://en.wikipedia.org/wiki/Hurricane_Marilyn
TWC naming criteria was revealed on WeatherBrains last night. Bryan Norcross revealed the criteria. He also said it was more of a marketing and a social media than a meteorological/science aim. The criteria is.....

1.Consider naming a storm if a storm will make significant impact,ice an snow.

2. Significant disruption to road and air travel.

3. If it was to cause life threatening conditions due to wind, snow, ice and cold.

This will be officially be revealed next week on TWC. There will also be another part to be released in about 2 weeks as it yet to be finalised.
Thanks Jeff...
Quoting AussieStorm:
TWC naming criteria was revealed on WeatherBrains last night. Bryan Norcross revealed the criteria. He also said it was more of a marketing and a social media than a meteorological/science aim. The criteria is.....

1.Consider naming a storm if a storm will make significant impact,ice an snow.

2. Significant disruption to road and air travel.

3. If it was to cause life threatening conditions due to wind, snow, ice and cold.


That interesting !!! So it is a marketing exercise , never would have thought that.....
Quoting VR46L:


That interesting !!! So it is a marketing exercise , never would have thought that.....

Wow. I'm surprised. Utterly shocked. Wow.
Quoting VR46L:


That interesting !!! So it is a marketing exercise , never would have thought that.....
Quoting TomballTXPride:

Wow. I'm surprised. Utterly shocked. Wow.


yeah, who would of thunk it. lol
Quoting TomballTXPride:

Wow. I'm surprised. Utterly shocked. Wow.


I am completely stunned ...LOL
At the NWA 37th Annual Meeting. The SPC revealed it has an experimental program and could add a few more categories to it's outlooks, currently it's Slight, Moderate and High. The new scale could be Slight, Marginal, Enhanced, Moderate and High.


Also at the NWA conference it was announced new WX Radios will contain GPS locators so it will know where it will be located in the forecast polygon.

Also announced the new GOES-R.
JeffMasters has created a new entry.