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

[cycloneye]

ABNT20 KNHC 152333
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT TUE SEP 15 2009

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

SHOWERS AND THUNDERSTORMS HAVE INCREASED IN ASSOCIATION WITH THE
REMNANTS OF FRED...LOCATED ABOUT 900 MILES EAST OF THE NORTHERN
LEEWARD ISLANDS. ENVIRONMENTAL CONDITIONS ARE MARGINALLY CONDUCIVE
FOR RE-DEVELOPMENT...AND THERE IS A LOW CHANCE...LESS THAN 30
PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS AS IT MOVES WEST-NORTHWESTWARD AT AROUND 15 MPH.
ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS
FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS
HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

AN AREA OF LOW PRESSURE ASSOCIATED WITH A TROPICAL WAVE IS LOCATED
ABOUT 350 MILES WEST OF THE CAPE VERDE ISLANDS. ALTHOUGH THE
ASSOCIATED SHOWERS AND THUNDERSTORMS HAVE INCREASED SOMEWHAT OVER
THE PAST FEW HOURS...FURTHER DEVELOPMENT OF THIS SYSTEM IS LIKELY
TO BE SLOW TO OCCUR AS IT MOVES WESTWARD AT AROUND 10 MPH. THERE
IS A LOW CHANCE...LESS THAN 30 PERCENT...OF THIS SYSTEM BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

A LARGE AREA OF DISORGANIZED SHOWERS AND THUNDERSTORMS EXTEND FROM
THE SOUTHEASTERN BAHAMAS NORTHEASTWARD TO NEAR BERMUDA. THIS
ACTIVITY IS ASSOCIATED WITH WEAK LOW PRESSURE AREA ALONG A FRONTAL
SYSTEM. UPPER-LEVEL WINDS ARE EXPECTED TO REMAIN UNFAVORABLE FOR
SIGNIFICANT DEVELOPMENT...AND THERE IS A LOW CHANCE...LESS THAN 30
PERCENT...OF THIS SYSTEM BECOMING A TROPICAL OR SUBTROPICAL CYCLONE
DURING THE NEXT 48 HOURS.

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

$$
FORECASTER BERG/PASCH

[AdamFirst]

Remains at yellow

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT TUE SEP 15 2009

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

1. SHOWERS AND THUNDERSTORMS HAVE INCREASED IN ASSOCIATION WITH THE
REMNANTS OF FRED...LOCATED ABOUT 900 MILES EAST OF THE NORTHERN
LEEWARD ISLANDS. ENVIRONMENTAL CONDITIONS ARE MARGINALLY CONDUCIVE
FOR RE-DEVELOPMENT...AND THERE IS A LOW CHANCE...LESS THAN 30
PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS AS IT MOVES WEST-NORTHWESTWARD AT AROUND 15 MPH.
ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS
FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS
HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

[JonathanBelles]

ENVIRONMENTAL CONDITIONS ARE MARGINALLY CONDUCIVE
FOR RE-DEVELOPMENT

Thats an upgrade from unfavorable conditions.

[ozonepete]

Is there any idea of where this will go if it does continue?

There's a lot of uncertainty, but so far the model runs forecast that the trough to its northwest won't catch it, which means it should probably make it to near the Bahamas by the weekend. But that's assuming that it stays a weak wave. Also, it could even dissipate before then. And should it strengthen more, it might go more to the right, so there's no way of telling very much right now. The models need good input data, especially as far as the strength of the system goes, and no one really knows how this will look 24 hours from now.

[ozonepete]

Remains at yellow

[/i][/b]

Yeah, I wasn't thinking 8, I was thinking 11. But curtadam is right - the NHC is conservative on these moves (usually), and so they're probably afraid of being wrong again after the last orange upgrade the other day. So maybe not even until 5AM.

[Ivanhater]

Is there any idea of where this will go if it does continue?

There's a lot of uncertainty, but so far the model runs forecast that the trough to its northwest won't catch it, which means it should probably make it to near the Bahamas by the weekend. But that's assuming that it stays a weak wave. Also, it could even dissipate before then. And should it strengthen more, it might go more to the right, so there's no way of telling very much right now. The models need good input data, especially as far as the strength of the system goes, and no one really knows how this will look 24 hours from now.

Actually then Bamd is the most southern model, so in this case, the stronger it becomes the more to the left

[ozonepete]

Is there any idea of where this will go if it does continue?

There's a lot of uncertainty, but so far the model runs forecast that the trough to its northwest won't catch it, which means it should probably make it to near the Bahamas by the weekend. But that's assuming that it stays a weak wave. Also, it could even dissipate before then. And should it strengthen more, it might go more to the right, so there's no way of telling very much right now. The models need good input data, especially as far as the strength of the system goes, and no one really knows how this will look 24 hours from now.

Actually then Bamd is the most southern model, so in this case, the stronger it becomes the more to the left

I don't follow that. They haven't run the BAMD in days for this system.

[JonathanBelles]

The BAM's ran all day today.

[cycloneye]

They haven't run the BAMD in days for this system.

The Bam Models did ran at 18z,Check the models thread.

[AdamFirst]

I don't follow that. They haven't run the BAMD in days for this system.

Check the models thread, they reinitialized it this afternoon.

edit: lol we all jumped on him

[cycloneye]

The BAM's ran all day today.

They only ran at 18z.Lets see if they do so at 00z.

[HURAKAN]

Lets see how it looks tomorrow morning

[ozonepete]

I don't follow that. They haven't run the BAMD in days for this system.

Check the models thread, they reinitialized it this afternoon.

edit: lol we all jumped on him

lol! Yeah I missed that, sorry. But I asked the question because steering currents for deep storms in that location seem to favor a more rightward turn, despite the one BAMD model's bias.

[masaji79]

Regardless if Fred redevelops or not, tonight's blow up of convection is nonetheless impressive. Seems to have occurred right over the existing center.

[cycloneye]

00 UTC Best Track

AL, 07, 2009091600, , BEST, 0, 203N, 485W, 30, 1010, LO

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

[cycloneye]

00 UTC Bam Models

SHIP intensity goes up to hurricane.

WHXX01 KWBC 160026
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0026 UTC WED SEP 16 2009

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

ATLANTIC OBJECTIVE AIDS FOR

DISTURBANCE FRED (AL072009) 20090916 0000 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
090916 0000 090916 1200 090917 0000 090917 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 20.3N 48.5W 21.2N 51.5W 22.3N 54.5W 23.5N 57.5W
BAMD 20.3N 48.5W 21.1N 50.8W 21.8N 53.4W 22.3N 56.1W
BAMM 20.3N 48.5W 21.2N 51.3W 22.1N 54.3W 22.9N 57.4W
LBAR 20.3N 48.5W 21.2N 51.4W 22.2N 54.4W 23.0N 57.4W
SHIP 30KTS 36KTS 43KTS 49KTS
DSHP 30KTS 36KTS 43KTS 49KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
090918 0000 090919 0000 090920 0000 090921 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 24.7N 60.0W 26.7N 63.9W 28.3N 66.3W 29.5N 69.1W
BAMD 22.5N 58.8W 22.6N 63.9W 22.3N 68.1W 21.8N 72.3W
BAMM 23.4N 60.2W 24.0N 65.3W 24.1N 69.7W 24.2N 74.6W
LBAR 23.7N 60.2W 24.5N 65.3W 24.3N 68.6W 20.7N 71.2W
SHIP 55KTS 63KTS 69KTS 72KTS
DSHP 55KTS 63KTS 69KTS 72KTS

...INITIAL CONDITIONS...
LATCUR = 20.3N LONCUR = 48.5W DIRCUR = 280DEG SPDCUR = 17KT
LATM12 = 19.7N LONM12 = 45.0W DIRM12 = 283DEG SPDM12 = 16KT
LATM24 = 19.1N LONM24 = 41.9W
WNDCUR = 30KT RMAXWD = 45NM WNDM12 = 25KT
CENPRS = 1010MB OUTPRS = 1012MB OUTRAD = 210NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

$$

[AdamFirst]

Gained about two degrees longitude in 6 hours. I'd say it's moving at a pretty good clip.

[Blown Away]

Ivanhater wrote: Actually then Bamd is the most southern model, so in this case, the stronger it becomes the more to the left

Yep, I noticed that to, models seem consistent w/ a decent ridge building.

[ozonepete]

Ivanhater wrote: Actually then Bamd is the most southern model, so in this case, the stronger it becomes the more to the left

Yep, I noticed that to, models seem consistent w/ a decent ridge building.

That's what it looks like. I'm really curious what they'll do if they initialize with a stronger system. Right now they are initializing with a 1010mb low. A shallow system pretty much HAS to go west with the trade winds. A deeper system will interact more with that digging trough. The complication is the timing of the trough lifting out. Could be anywhere from Florida to well off the east coast.

[ronjon]

GFS showing pretty strong ridging over the next 72-120 hrs over the SW Atlantic so its not surprising the deeper system would trun more west or even W-SW. The 00Z BAM suite just out brings former Fred up to hurricane strength in the Bahamas just off SE FL in 5 days.