ATL: Ex COLIN - Discussion

[jconsor]

Surface observations in the NE Caribbean suggest Colin may be close to closing off a circulation, though the winds with a westerly component are quite light.

Anguilla - SSW @ 6 mph: http://www.wundergro...sp?ID=ITHEVALL2
St. Martin - W @ 3 mph: http://www.wundergro...ilyHistory.html
Nevis - SSW @ 6 mph: http://www.wundergro...ilyHistory.html
St. Kitts - WNW @ 6 mph: http://www.wundergro...ilyHistory.html
Dominica - SW @ 6 mph: http://www.wundergro...ilyHistory.html
Buoy 42060 - WSW @ 2 mph: http://www.wunderground.com/weatherstat ... ?ID=M42060

[Gustywind]

Tropical Weather Discussion
Issued: Wednesday, August 4, 2010 810 am EDT/710 am CDT

Discussion

Remnant Low Pressure Colin:
Tropical Storm Colin was downgraded to a remnant low pressure system late yesterday afternoon and is located this morning about 200 miles east of the Leeward Islands. The reason why Colin was downgraded was because the combination of a low-level easterly jet, strong high pressure and stronger wind shear than what was anticipated basically decapitated Colin and the low-level center outran the convection. It should be noted that analysis this morning indicates that the mid level center is still fairly strong. So, I expect the strong shear to continue through tonight and possibly into part of Thursday; however, after Thursday, both the shear and Colin’s forward speed are forecast to dramatically decrease and it looks fairly likely that regeneration into a tropical storm could occur as soon as late Friday or Saturday. This is why I have not removed the webpage dedicated to Colin, since I do expect regeneration and then intensification.

In the short term, heavy rainfall and gusty winds are likely across the Leeward Islands and the Virgin Islands today into tonight as the remnant low Colin passes just northeast of you folks.

Looking further out, the environmental conditions late this week into this weekend may be quite favorable and basically the further west it can get over the next few days, the higher the risk on the US East Coast. The NOGAPS model is the furthest west and forecasts Colin to be intensifying while it approaches the coast of South and North Carolina early next week. Many of the other hurricane track models seem to have shifted to the east a bit overnight and curve the storm out to sea around 68 or 69 West Longitude. The European model is kind of interesting as it initially forecasts Colin to curve northward around 68 West Longitude on Saturday, but then be pushed westward towards the North Carolina coast by high pressure to its north on Sunday and Monday.

I continue to stick to my guns and think that Colin will track west of most of the hurricane track models. I am just having a really hard time believing that the weakness to the north will pick up a weak system like this in just 24 to 48 hours. This is what I am thinking for a track and intensity over the next five days:


Thursday Morning: 20 North Latitude, 67.5 West Longitude. 30 mph remnant low.
Friday Morning: 23.5 North Latitude, 71.5 West Longitude. 30 mph remnant low.
Saturday Morning: 25.5 North Latitude, 71.0 West Longitude. 40 mph tropical storm.
Sunday Morning: 28.0 North Latitude, 70.9 West Longitude. 50-55 mph tropical storm.
Monday Morning: 30.0 North Latitude, 73.0 West Longitude. 75 mph hurricane.


So, bottom line is that I do not think we have heard the last from Colin and regeneration and then intensification seems fairly likely this weekend. Needless to say, I will be monitoring things closely over the next few days and will keep you all updated.

The next tropical weather discussion will be issued by 7 am EDT/6 am CDT Thursday morning.

[Aric Dunn]

Surface observations in the NE Caribbean suggest Colin may be close to closing off a circulation, though the winds with a westerly component are quite light.

Anguilla - SSW @ 6 mph: http://www.wundergro...sp?ID=ITHEVALL2
St. Martin - W @ 3 mph: http://www.wundergro...ilyHistory.html
Nevis - SSW @ 6 mph: http://www.wundergro...ilyHistory.html
St. Kitts - WNW @ 6 mph: http://www.wundergro...ilyHistory.html
Dominica - SW @ 6 mph: http://www.wundergro...ilyHistory.html
Buoy 42060 - WSW @ 2 mph: http://www.wunderground.com/weatherstat ... ?ID=M42060

yeah was just looking at some of those obs... its quite close..

[Gustywind]

From Crown Weather: http://www.crownweather.com/?page_id=325

[Aric Dunn]

Surface observations in the NE Caribbean suggest Colin may be close to closing off a circulation, though the winds with a westerly component are quite light.

Anguilla - SSW @ 6 mph: http://www.wundergro...sp?ID=ITHEVALL2
St. Martin - W @ 3 mph: http://www.wundergro...ilyHistory.html
Nevis - SSW @ 6 mph: http://www.wundergro...ilyHistory.html
St. Kitts - WNW @ 6 mph: http://www.wundergro...ilyHistory.html
Dominica - SW @ 6 mph: http://www.wundergro...ilyHistory.html
Buoy 42060 - WSW @ 2 mph: http://www.wunderground.com/weatherstat ... ?ID=M42060

although if you look on visible there is small eddy just NE of PR which could be the reason for those obs ??
http://www.ssd.noaa.gov/goes/flt/t1/loop-rgb.html

[CrazyC83]

Even with those winds, I would want something more conclusive before resuming advisories as Tropical Storm Colin. Maybe at 11 pm tonight if the trend continues (since no watches or warnings would be necessary as the TS winds are well away from the islands).

[jconsor]

That small Eddy near PR would be highly unlikely to affect winds as far south and east as Dominica and St. Kitts/Nevis.

Surface observations in the NE Caribbean suggest Colin may be close to closing off a circulation, though the winds with a westerly component are quite light.

Anguilla - SSW @ 6 mph: http://www.wundergro...sp?ID=ITHEVALL2
St. Martin - W @ 3 mph: http://www.wundergro...ilyHistory.html
Nevis - SSW @ 6 mph: http://www.wundergro...ilyHistory.html
St. Kitts - WNW @ 6 mph: http://www.wundergro...ilyHistory.html
Dominica - SW @ 6 mph: http://www.wundergro...ilyHistory.html
Buoy 42060 - WSW @ 2 mph: http://www.wunderground.com/weatherstat ... ?ID=M42060

although if you look on visible there is small eddy just NE of PR which could be the reason for those obs ??
http://www.ssd.noaa.gov/goes/flt/t1/loop-rgb.html

[Aric Dunn]

That small Eddy near PR would be highly unlikely to affect winds as far south and east as Dominica and St. Kitts/Nevis.

Surface observations in the NE Caribbean suggest Colin may be close to closing off a circulation, though the winds with a westerly component are quite light.

Anguilla - SSW @ 6 mph: http://www.wundergro...sp?ID=ITHEVALL2
St. Martin - W @ 3 mph: http://www.wundergro...ilyHistory.html
Nevis - SSW @ 6 mph: http://www.wundergro...ilyHistory.html
St. Kitts - WNW @ 6 mph: http://www.wundergro...ilyHistory.html
Dominica - SW @ 6 mph: http://www.wundergro...ilyHistory.html
Buoy 42060 - WSW @ 2 mph: http://www.wunderground.com/weatherstat ... ?ID=M42060

although if you look on visible there is small eddy just NE of PR which could be the reason for those obs ??
http://www.ssd.noaa.gov/goes/flt/t1/loop-rgb.html

well its not like they are strong winds.. lol but yeah figured i would mention it anyway

[Macrocane]

Does anybody else think it has become a little better organized in the last few hours? The rotation is more evident even if it is still at the mid level, I think that we could have a tropical storm again in 24 hours, and if this maps are correct http://www.meteo.psu.edu/~gadomski/COMPSHEARATL_0z/comploop.html the wind shear will be very low in 96 hours more or less the time when most of the models show intensification.

[Gustywind]

[Riptide]

It appears that Colin is back in black.

[supercane]

Unchanged SSD Dvorak classification:

DATE/TIME LAT LON CLASSIFICATION STORM
04/1745 UTC 19.5N 60.8W T1.5/1.5 COLIN -- Atlantic
04/1145 UTC 17.9N 59.8W T1.5/1.5 COLIN -- Atlantic

[Gustywind]

000
ABNT20 KNHC 041754
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT WED AUG 4 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT
INVESTIGATING THE REMNANTS OF TROPICAL STORM COLIN INDICATE THAT
THE SYSTEM DOES NOT HAVE A CLOSED SURFACE CIRCULATION. HOWEVER...
THE AIRCRAFT FOUND WINDS OF TROPICAL-STORM FORCE IN THE
NORTHEASTERN PORTION OF THE SYSTEM. UPPER-LEVEL WINDS ARE
CURRENTLY NOT CONDUCIVE FOR DEVELOPMENT...AND THERE IS A LOW
CHANCE...20 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
AGAIN DURING THE NEXT 48 HOURS AS IT MOVES WEST-NORTHWESTWARD AT 20
TO 25 MPH. REGARDLESS OF DEVELOPMENT...LOCALLY HEAVY RAINS AND
STRONG GUSTY WINDS ARE POSSIBLE OVER PORTIONS OF THE LEEWARD AND
VIRGIN ISLANDS ISLANDS TODAY AND TONIGHT.
CLOUDINESS...SHOWERS...AND THUNDERSTORMS OVER THE CENTRAL AND
SOUTHWESTERN CARIBBEAN SEA ARE ASSOCIATED WITH A TROPICAL WAVE.
THIS SYSTEM HAS CHANGED LITTLE IN ORGANIZATION DURING THE PAST
SEVERAL HOURS. SLOW DEVELOPMENT OF THIS DISTURBANCE IS POSSIBLE
OVER THE NEXT FEW DAYS AS IT MOVES GENERALLY WESTWARD AT 15 TO 20
MPH. THERE IS A LOW CHANCE...20 PERCENT...OF THIS SYSTEM BECOMING
A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BEVEN

[supercane]

18Z best track from ATCF:

AL, 04, 2010080412, , BEST, 0, 179N, 595W, 30, 1008, LO, 0, , 0, 0, 0, 0, 1011, 125, 30, 0, 0, L, 0, , 0, 0, COLIN, S,
AL, 04, 2010080418, , BEST, 0, 194N, 612W, 35, 1010, WV, 34, NEQ, 30, 0, 0, 0, 1012, 125, 30, 0, 0, L, 0, , 0, 0, COLIN, S,

[hurricaneCW]

The most we'll probably see with Colin is a moderately sheared 45-50 mph tiny storm that heads well out to sea not harming anyone. It's quickly become less organized by the hour. It will be in the strong shear zone for another 3 days. This disturbance is not a big deal. I don't even think it will regenerate because conditions won't really improve that much. The shear will probably drop from 30+ knots to 15-20 knots which is still not low enough to provide for any organization.

[HURAKAN]

Looking at the loops, the MLC is quite powerful

[Aric Dunn]

if there was not a circulation before there is one now.. or even closer.. lol

[CrazyC83]

I don't see any evidence of a closed LLC.

[tolakram]

How about just NE of PR with new convection building.

LOOP: http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... umframes=5

[HURAKAN]

Bursting over the MLC