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

[boca]

Ex Fred does look better on the sat this morning. At least its not a naked swirl anymore.As far as its trek across the Atlantic this will probably recurve.The trough thats lying across the Bahamas will most likely protect the East coast. If the trough moves out quick enough and the bermuda high strengthens which it hasn't yet this year,then we have to really watch Ex Fred.

[boca]

It does look like an upper low on the water vapor loop.

[KUEFC]

For someone just getting into following storms etc is an upper low good or bad for development?

[Sanibel]

Bad.


The upper airflow has to move opposite to the lower cyclonic (counterclockwise) inflow to vent the air out of the system. With the Upper Low the airflow is also counterclockwise at the higher levels which stifles the needed airflow to make a cyclone work. If you look at a hurricane you can see thin clouds vent away from it in a clockwise fashion.

[Evil Jeremy]

For someone just getting into following storms etc is an upper low good or bad for development?

Bad. An upper level low creates shear for a system.

[Derek Ortt]

there is little shear directly under an upper low

However, TCs usually develop under ULs late in the season in the north Atl. Not here in the MDR

[Derek Ortt]

circ appears to be weakening on visible sat imagery

Probably will be a wave by this time tomorrow

[storms NC]

Why is this still on the Active Storms? Just asking cause it is not any thing but a wave and that will soon be gone for the ULL has ate it for breakfast.





ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT TUE SEP 15 2009

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

1. SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THE REMNANTS OF FREDLOCATED ABOUT 1100 MILES EAST OF THE NORTHERN LEEWARD ISLANDS HAVE
INCREASED THIS MORNING. ENVIRONMENTAL CONDITIONS COULD BECOME
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. 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.
2. A TROPICAL WAVE LOCATED A COUPLE HUNDRED MILES WEST OF THE CAPE
VERDE ISLANDS IS PRODUCING AN AREA OF DISORGANIZED SHOWERS AND
THUNDERSTORMS. DEVELOPMENT...IF ANY...OF THIS SYSTEM IS EXPECTED
TO BE SLOW TO OCCUR. THERE IS A LOW CHANCE...LESS THAN 30
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 BROWN
NNNN

[Evil Jeremy]

Why is this still on the Active Storms? Just asking cause it is not any thing but a wave and that will soon be gone for the ULL has ate it for breakfast.





ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT TUE SEP 15 2009

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

1. SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THE REMNANTS OF FREDLOCATED ABOUT 1100 MILES EAST OF THE NORTHERN LEEWARD ISLANDS HAVE
INCREASED THIS MORNING. ENVIRONMENTAL CONDITIONS COULD BECOME
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. 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.
2. A TROPICAL WAVE LOCATED A COUPLE HUNDRED MILES WEST OF THE CAPE
VERDE ISLANDS IS PRODUCING AN AREA OF DISORGANIZED SHOWERS AND
THUNDERSTORMS. DEVELOPMENT...IF ANY...OF THIS SYSTEM IS EXPECTED
TO BE SLOW TO OCCUR. THERE IS A LOW CHANCE...LESS THAN 30
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 BROWN
NNNN

You missed the part I put in bold. Storms are on the up rise, shear is going down. This is still an invest on NRL, thus it should be in here, and this is more than an open wave, this has a circulation to it still.

[jlauderdal]

circ appears to be weakening on visible sat imagery

Probably will be a wave by this time tomorrow

isnt it a wave now or you are saying it wont get any stronger than it is now?

[Evil Jeremy]

I don't know why this would qualify as a wave right now, it still has a nice circulation to it. Its weaker than before, but its still there, firing convection.

[Derek Ortt]

1. The convection is pitiful

2. It should be a wave by this time tomorrow

[brunota2003]

Haven't people been saying it should of been a wave a long time ago? When will they finally be right and it opens up?

[brunota2003]

To answer my own question...the surface low is extremely elongated, extending from about 46.6W to 44.0W, and is very narrow from north to south. The strongest winds on the south side are an EXTREMELY strong 5 knots, with some barbs indicating 2.5 to 0 knots a little further out.

On the northeast side of the low, there are still some 30 knot barbs. It is roping out slowly but surely...and Derek's guess of it dissipating by this time tomorrow might be conservative. If it doesn't gain convection very soon, it could well be an open trough by the next QuikScat pass.

[cycloneye]

Comments by Dr Jeff Masters about Ex Fred.

The remains of Hurricane Fred continue to generate sporadic bursts of heavy thunderstorm activity over the middle Atlantic Ocean. These thunderstorms were generating winds up to 35 mph, according to this morning's QuikSCAT pass. Dry air and high wind shear of 20 - 25 knots today and Wednesday will continue to prevent regeneration of Fred. By Thursday, the chances for regeneration of Fred increase, since wind shear near Fred's remains will fall below 20 knots. However, continued high wind shear and dry air over the next two days will further disrupt the remains of Fred, and there may not be enough left of the storm to regenerate from by the time the wind shear drops. The NOGAPS model forecasts that Fred could regenerate by Sunday, when the remains of the storm will be approaching the Bahama Islands.

[cycloneye]

Why is this still on the Active Storms?

First,Best Track is continuing to release the plots every six hours like they normally do when systems are invest and second,NHC is still mentioning the system.

[perk]

1. The convection is pitiful

2. It should be a wave by this time tomorrow

That's what you said two days ago.

[Shewtinstar]

So am I understanding this right? NHC is saying Fred could regenerate, but it's a low chance that it will do so within 48 hrs? That means after the 48 hr window it could come back again?

[jlauderdal]

So am I understanding this right? NHC is saying Fred could regenerate, but it's a low chance that it will do so within 48 hrs? That means after the 48 hr window it could come back again?

it means they think there is less than a 30% chance it will become a tropical cyclone in the next 48 hours. It means that we will find out at the next forecast(every hours) we will find out what they think might happen in the next 48 hour period.

I get the feeling some people including our local media think that oh well there is a less than a 30% chance it will ever develop so lets all feel real safe that nothing will ever happen.

[Aric Dunn]

The convection is getting ready to refire ... with less shear since it nearly right under the weak ull which does not really help for and major redevelopment but back to td status or TS is possible..

its cool watching the pressure waves this morning coming from it..