Invest 99L Thread #6

[astrosbaseball22]

hmmm its blowing up agian

[tailgater]

I have a question for those more knowlegdeable than myself. Is mid level energy just as likely to react to diurnal Max's and Min's as low-level energy?

[mgpetre]

Does anyone know where I could find multiple day satellite loops of the Atlantic/Carribean/Wide Atl sats? I would really like to be able to investigate the full life cycle of this storm. Perhaps I should start my own archive? Just hoping someone knew where one already existed.

Thanks in advance

[El Nino]

Good morning all.

Well, nothing interesting today. NEXT !

[Sanibel]

There's a weak spiral near 15.2N-77-78W from which the deeper convection is originating. Clearly visible on satellite if some computer savvy poster wants to cut and highlight it.

[astrosbaseball22]

There's a weak spiral near 15.2N-77W from which the deeper convection is originating. Clearly visible on satellite if some computer savvy poster wants to cut and highlight it.

do you think thats a LLC

[Sanibel]

It's some kind of center, whether mid-level or not, trying to get down but not being able to because it is being given the bum's rush by the wicked forward speed of the trade winds along with the shear pushing its convection off.

I don't think it will slow enough to form before Yucatan. But we'll see tomorrow since it is moving so fast it will probably be there by then.

[astrosbaseball22]

It's some kind of center, whether mid-level or not, trying to get down but not being able to because it is being given the bum's rush by the wicked forward speed of the trade winds along with the shear pushing its convection off.

I don't think it will slow enough to form before Yucatan. But we'll see tomorrow since it is moving so fast it will probably be there by then.

i dont think it will

[HURAKAN]

99L, your time is up. My conservative side just gave up!!!

Good luck in the EPAC.

[mgpetre]

99L, your time is up. My conservative side just gave up!!!

Good luck in the EPAC.

Looks to me like the steering currents and the trough in the GOM are making it just as likely this thing (however small it will be) will end up in the BAC or even the GOM.

[astrosbaseball22]

99L, your time is up. My conservative side just gave up!!!

Good luck in the EPAC.

Looks to me like the steering currents and the trough in the GOM are making it just as likely this thing (however small it will be) will end up in the BAC or even the GOM.

this may be a rain event for texas or mexico next week

[philnyc]

I have a question for those more knowlegdeable than myself. Is mid level energy just as likely to react to diurnal Max's and Min's as low-level energy?

When the diurnal max comes after dark, the reason you get stronger convection (tstorms) is that the cloud tops of whatever showers and thunderstorms are there radiate energy out into space and thus cool down. Cooler temperatures at the tops of these clouds increases the temperature difference between the warm sea surface and the tops of the clouds. This steeper temperature diference causes the air to rise higher and faster, i.e. the thunderstorms grow in size. It's a positive feedback loop that goes on until the sun comes back out.
So given that, all energy levels from low to mid to upper are affected in the sense that they all see a kinetic energy increase due to air rising higher and faster within the disturbance. If by lower levels you mean the surface, even there we must see an energy increase, since the surface air gets drawn in faster as the divergence increases at the top levels.

[mgpetre]

Should be interesting to see what sort of observations come out of Jamaica later today. I guess I'll try and find a radar site for them.

[astrosbaseball22]

Should be interesting to see what sort of observations come out of Jamaica later today. I guess I'll try and find a radar site for them.

winds in it are still 30-35 ...

[DESTRUCTION5]

I don't know if this should be marked dead yet..Actually its about to apply the brakes a little and run into a very friendy area..

http://www.ssd.noaa.gov/goes/east/watl/loop-avn.html

The fact that its northern end looks to become dominant could actually get this in to the W Carribean and BOC...I still like its chances..And no i'm blowing wish-casting dust..

[vaffie]

Corpus Christi NWS office has discussion about the wave being forecast by the GFS, European and DGEX (high-resolution NAM) to affect the Texas coastline on day 7 (Thursday of next week).

LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...MODELS ARE IN PRETTY GOOD AGREEMENT WITH A MID LEVEL WAVE MVG ACROSS THE REGION ON SUNDAY AND A RIDGE BLDG W ACROSS THE NRN GULF THRU MON. THIS WILL CONTINUE TO PROVIDE A DEEP SLY FLOW INTO S TX WHICH WILL TAP INTO MOISTURE LOCATED ACROSS THE SRN GULF AND PUMP INTO THE AREA. INHIBITING FACTOR WILL BE THE UPPER LEVEL RIDGE AND CONFLUENT FLOW ALOFT. THEREFORE AM EXPECTING ISOL CONVECTION AT BEST WITH THE AFTERNOON SEA BREEZE BEING THE LOW LEVEL FORCING MECHANISM. BY TUESDAY THERE IS A BRIEF PERIOD OF DIFFLUENCE ALOFT THAT MAY ALLOW MORE CONVECTION TO DVLP BUT THE MID LEVEL RIDGE WILL BE FARTHER W THEREFORE WILL CONTINUE WITH ONLY A SLIGHT CHC. THE RIDGE CONTINUES TO MOVE W ACROSS THE REGION WITH DRYING IN THE MID/UPPER LEVELS THRU W THEN BY THU A TROPICAL ELY WAVE TRAVERSES S TX WITH INCREASING MOISTURE. THE ECMWF/GFS/DGEX ALL SHOW THIS WAVE ON THU THEREFORE CONFIDENCE IS GOOD BUT GIVEN THIS IS DAY 7 WILL NOT JUMP ON IT YET.

[skysummit]

Here's what I was talking about on an earlier post. AGAIN....nothing scientific, basically just gave me an excuse to draw on a map.

The wave axis still hauls off to the west. In the meantime, shear enhances thunderstorm development on the northern periphery of the wave. That convection is generally moving in a wnw - nw direction. If convection persists till the Yucatan Channel, conditions should be better and also a slower low level flow should be apparent.

Opinions?

[mgpetre]

If a pro or very experienced Met sees skysummit's post could you please elaborate on the validity of the possibility he presents? I too believe it looks like this is what is occuring, but I am not sure where all of the energy from the wave winds up in this scenario. There's not much else going on tropically, could someone help us put this to rest if that is what needs to happen?

[Emmett_Brown]

I have a question for those more knowlegdeable than myself. Is mid level energy just as likely to react to diurnal Max's and Min's as low-level energy?

When the diurnal max comes after dark, the reason you get stronger convection (tstorms) is that the cloud tops of whatever showers and thunderstorms are there radiate energy out into space and thus cool down. Cooler temperatures at the tops of these clouds increases the temperature difference between the warm sea surface and the tops of the clouds. This steeper temperature diference causes the air to rise higher and faster, i.e. the thunderstorms grow in size. It's a positive feedback loop that goes on until the sun comes back out.
So given that, all energy levels from low to mid to upper are affected in the sense that they all see a kinetic energy increase due to air rising higher and faster within the disturbance. If by lower levels you mean the surface, even there we must see an energy increase, since the surface air gets drawn in faster as the divergence increases at the top levels.

I'm a mad scientist, (not officially a meterologist), but that was a great explanation of diurnal convection. This is the same reason that thunderstorms break out during the day over land. Does anyone know what height in the atmosphere this "cooling" takes place at so as to trigger nighttime convection? Also, does anyone have maps that chart this type of instability (difference in temp between lower and upper levels)... is this the same as the lifted index?

Another comment: Perhaps this a contributing factor for why tropical activity picks up in Autumn... peak water temps from a season of heating, with an upper atmosphere that is colder because nights grow longer, hence more convection, and in turn more cyclones.

[punkyg]

hmmmmmmm.