ULL ----->TD?

[Stormavoider]

How often do ULLs transition to tropical systems? Is there much history of this?

[senorpepr]

I found this:

There are also suggestions that TUTTs can assist tropical cyclone genesis and intensification by providing additional forced ascent near the storm center and/or by allowing for an efficient outflow channel in the upper troposphere. For a more detailed discussion on TUTTs see the article by Fitzpatrick et al. (1995).

Here:

http://www.aoml.noaa.gov/hrd/tcfaq/A10.html
So apparently a TUTT can aid in development of and Tropical Cyclone.

[Stormavoider]

I found this:

There are also suggestions that TUTTs can assist tropical cyclone genesis and intensification by providing additional forced ascent near the storm center and/or by allowing for an efficient outflow channel in the upper troposphere. For a more detailed discussion on TUTTs see the article by Fitzpatrick et al. (1995).

Here:

http://www.aoml.noaa.gov/hrd/tcfaq/A10.html
So apparently a TUTT can aid in development of and Tropical Cyclone.

Huh?

[O Town]

Upper Level Low=TUTT
But still that article doesn't really answer your question, I was also kinda of curious as to how often they work down to the surface and develope into a tropical system. Does any come to mind?

[senorpepr]

Sorry... that was an incomplete answer I gave earlier... I was distracted. Anyway... they ratherly becoming tropical cyclones themselves, although they do occasionally help approaching waves into tropical cyclones.

Basically, it takes a LOT for an upper-level low to stretch from roughly 30,000 ft all the way down to the surface, but it can happen in the right cases.

[HurricaneBill]

A good example is T.S. Beryl in 1994. An ULL entered the Gulf of Mexico and transitioned into a tropical depression and eventually became Beryl.

[Matt-hurricanewatcher]

How thing works or how I believe this works...See a ULL is like a upper level extratropical cyclone. Which forms above 18,000 feet or 500 millibars. This system often forms a surface area of low pressure to its southeastern side. Or aids in its development. Now how doe's one go from a cold core area of upper level low pressure to a tropical cyclone?

See convection is really heat evp off the oceans that rise into the Atmosphere. This once reachs its dew point releases heat. Which warms the area around it=more convection. Once convection starts forming with in the ULL the ULL becomes more warmer core...When this happens the winds start moving into the warmer core. Remember winds move from area's of high pressure to low pressure. What happens is as the core warms up it turns into a surface low pressure. This in the Coli force(Can't spell it)starts moving the winds into the system. Which makes the ULL move down to the surface as a surface low.

I hope that answers you quastion???

[Aslkahuna]

TUTT Lows and ULLs are two different animals but the answer is yes, both can become Tropical Cyclones and in fact, a cutoff ULL developing into a Tropical systems due to thr release of latent heat from convection is a relatively common occurrence in the ATL early and late in the season. Cutoffs are not tremendously common in the WPAC so that method of formation is relatively rare but as mentioned in the TUTT thread TUTT Lows can account for about 16% or so of the total number of WPAC storms each year on average.

Steve