ATL: TROPICAL LOW ex-FRED (ex-07L)

[Derek Ortt]

GFS dissipates Fred

Fred is dead

i thought you said gfs is Good For Sh*t

mentioned it because despite the "favorable" conditions, GFS dissipates Fred

[Lurker]

Surprised. Usually Derek Ortt takes the GFDL as the gospel.

Just a question, Ortt. Why do you consistently differ from the NHC in forecasts? I.e in intensity, track, factors, and conclusions usually are always different from the NHC. Do you try to be different than them, or are you being different for the sake of just.. being different?

Can you post an example or link that verifies this? Derek's forecast usually mirror NHC.

[cycloneye]

Best track continues to follow what is left.

AL, 07, 2009091300, , BEST, 0, 176N, 339W, 30, 1006, LO

ftp://ftp.tpc.ncep.noaa.gov/atcf/tcweb/ ... 009.invest

[ozonepete]

Surprised. Usually Derek Ortt takes the GFDL as the gospel.

Just a question, Ortt. Why do you consistently differ from the NHC in forecasts? I.e in intensity, track, factors, and conclusions usually are always different from the NHC. Do you try to be different than them, or are you being different for the sake of just.. being different?

what in the world are you talking about? Usually, the forecasts are very similar (about 95% of the time they are similar). Reread the NHC and NWHHC archives

I do not use GFDL/HWRF in sheared cases because it has parametrized convection. Parametrized convection makes a model storm shear resistant. I've seen this numerous times in the MM5/ARW running at 12 vs 4km resolution. No more high res runs on Fred, though

I would agree that you are almost always in lockstep with the NHC. And I see your point about the GFDL/HWRF bias because of PARAMETERIZED convection. But isn't it fairly obvious that a 4km resolution model run will deal more accurately with mesoscale effects of shear than a 12km will?

[Emmett_Brown]

Dudes, can we talk about Fred instead of Derek?

[Emmett_Brown]

GFDL, CMC and NOGAPS show Fred surviving to varying degrees, so there is at least some model support

[Derek Ortt]

Surprised. Usually Derek Ortt takes the GFDL as the gospel.

Just a question, Ortt. Why do you consistently differ from the NHC in forecasts? I.e in intensity, track, factors, and conclusions usually are always different from the NHC. Do you try to be different than them, or are you being different for the sake of just.. being different?

what in the world are you talking about? Usually, the forecasts are very similar (about 95% of the time they are similar). Reread the NHC and NWHHC archives

I do not use GFDL/HWRF in sheared cases because it has parametrized convection. Parametrized convection makes a model storm shear resistant. I've seen this numerous times in the MM5/ARW running at 12 vs 4km resolution. No more high res runs on Fred, though

I would agree that you are almost always in lockstep with the NHC. And I see your point about the GFDL/HWRF bias because of PARAMETERIZED convection. But isn't it fairly obvious that a 4km resolution model run will deal more accurately with mesoscale effects of shear than a 12km will?

my spell check flags PARAMETERIZED as incorrect and spells it the way I did

[cycloneye]

Ok folks,I think we can return to discuss about Fred without going to personal things.

[jinftl]

Taking a look at all the tds that have been in the vicinity of fred reveals only one actually making it to the u.s......fran in 1996. As of now, the only thing Fred and Fran will probably have in common is they are both 4-letter F names.

[jinftl]

Interesting image...looks like ridging will build in




Important to keep in mind that what may be tracking west is just a remant low.

[AdamFirst]

Hard to tell but it looks like the ghost of Fred is starting to trek west...

http://www.ssd.noaa.gov/goes/east/catl/flash-rb.html

[jinftl]

yep, just posted latest model runs in the model thread.....important to keep in mind that what the models are forecasting to move west is anything from a remnant low to a td to a ts in a few cases. In other words, track may not really matter so much if we are dealing with a remnant low. At least that is the thinking, which is very good, because shear is going to be easing up down the road.

From Dr. Jeff Master's today:

Tropical Storm Fred has been ripped apart by wind shear, as strong southerly winds of 20 knots have removed all of Fred's heavy thunderstorms, leaving only a naked low-level swirl of clouds. Wind shear of 20 - 40 knots will continue today through Monday, and Fred should dissipate by Sunday night.

Due to the continued strong shear expected over Fred the next four days, it is unlikely there will be anything left of the storm to regenerate from once the remains reach an area with moderate wind shear five days from now.

Hard to tell but it looks like the ghost of Fred is starting to trek west...

http://www.ssd.noaa.gov/goes/east/catl/flash-rb.html

[ozonepete]

"my spell check flags PARAMETERIZED as incorrect and spells it the way I did."

Google it. Both are corrrect, but parametrized is not the standard that has been used in most of the literature. And MS WORD flags parametrized but does not flag parameterized. Try it. I don't know what text editor you are using.

And that was a minor point of my question.

[JonathanBelles]

HIGH SEAS FORECAST
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0430 UTC SUN SEP 13 2009

...

.REMNANT LOW OF FRED 1006 MB NEAR 17N34W MOVING W 5 KT. OVER
FORECAST WATERS WITHIN 240 NM NW QUADRANT NE WINDS 20 TO 25 KT.
SEAS 8 TO 12 FT. WITHIN 120 NM SW QUADRANT NW WINDS 20 KT. SEAS
8 TO 10 FT.
.24 HOUR FORECAST REMNANT LOW 1010 MB NEAR 19N36W. OVER FORECAST
WATERS WITHIN 240 NM N SEMICIRCLE WINDS 20 TO 25 KT. SEAS 8 TO
12 FT. WITHIN 90 NM S SEMICIRCLE WINDS 20 KT. SEAS TO 9 FT.
.48 HOUR FORECAST REMNANT LOW NEAR 21N41W. WITHIN 240 NM N
SEMICIRCLE WINDS 20 TO 25 KT. SEAS 8 TO 12 FT. WITHIN 120 NM S
SEMICIRCLE WINDS 20 KT. SEAS TO 8 FT. ELSEWHERE FROM 22N TO 30N
E OF 42W E WINDS 20 KT. SEAS TO 9 FT IN NE SWELL.

[hurricanetrack]

Fred still has a phenomenal low level structure. Incredible on today's vis sat pics.

[Derek Ortt]

Firefox and MS word seem to have some differences in how to flag it (I always thought it was with the e). learn something every day

[ozonepete]

Firefox and MS word seem to have some differences in how to flag it (I always thought it was with the e). learn something every day

All's good, Derek, and a lot of respect. I've learned a lot from watching your forecasts.

[cycloneye]

The big wheel continues to roll on slowly westward.

[cycloneye]

Umm,they have a yellow circle.

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT SUN SEP 13 2009

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

A LOW PRESSURE AREA...THE REMNANT CIRCULATION OF FRED...IS LOCATED
ABOUT 625 MILES WEST OF THE NORTHERNMOST CAPE VERDE ISLANDS. WHILE
REGENERATION INTO A TROPICAL CYCLONE IS NOT EXPECTED DURING THE
NEXT COUPLE OF DAYS...THIS SYSTEM WILL LIKELY PRODUCE DISORGANIZED
AND INTERMITTENT SHOWERS AND THUNDERSTORMS AS IT MOVES SLOWLY
WESTWARD. THERE IS A LOW CHANCE...LESS THAN 30 PERCENT...OF THIS
SYSTEM BECOMING A TROPICAL CYCLONE AGAIN DURING THE NEXT 48 HOURS.

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

$$
FORECASTER BROWN

[jconsor]

A small but intense area of convection has blown up on the north side of Fred in the past 3 hours. This is a sign of life, even if shear values are prohibitively high now and will be for the 2 days. Also, Fred is still moving WNW and is 50-100 miles south of the NHC forecast and other model guidance.