ATL: TROPICAL DEPRESSION ALEX - DISCUSSION

[CrazyC83]

An early turn into the oil spill zone would likely keep Alex a tropical storm. The strongest storm potential would likely be a NE Mexico landfall south of the Rio Grande, where it could get to Cat 3 (maybe Cat 4).

[cycloneye]

Here is the 1 PM CDT summary of intermediate advisory.

SUMMARY OF 100 PM CDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...20.3N 91.7W
ABOUT 85 MI...135 KM WNW OF CAMPECHE MEXICO
ABOUT 535 MI...860 KM SE OF BROWNSVILLE TEXAS
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/HR
PRESENT MOVEMENT...NNW OR 330 DEGREES AT 5 MPH...7 KM/HR
MINIMUM CENTRAL PRESSURE...990 MB...29.23 INCHES

[Texashawk]

Those are some very strong words, coming from you, AFM. You're not typically one to swing too high or low, in my time on these boards. Interesting and sobering.

I wrote a little note in the recon thread about the pressure change. Its likely diurnal. I wouldn't get too excited.

Here is what I said: "Diurnal changes. 10 am is usually the diurnal max for pressure...accounting for a 2-3 MB increase in pressure from 4 am - 10/11 am. 4 PM is usually the diurnal min and you can get a 2-3 mb drop during that time."

In actuality, Alex's current condition ought to make us all very concerned. The poster who got a little crucified earlier was really not that far off when he said it could be a cat 4. The same thing was said this morning by an official source. I wont say where...and when...but it was talked about. Fact is, Alex is sucking in dry air off of Mexico...its getting sheared some...it lacks a great inner core...its sitting over some of the lowest TCHP and coolest SST's in the Gulf...

And it has a 989 mb pressure which is steady/falling. It FELL 5 MB over LAND...

As a Pro-Met...that gives me a LOT of concern. I do not look at him as something ragged or pathetic...disorganized. I am kinda of worried that once he gets the tools he needs...its Katy bar the door.

[CrazyC83]

I'd argue it has weakened a bit the last 6 hours to 45 kt, but I doubt the NHC would put that in an advisory if it goes against trends.

[KWT]

Upper level shear really is dropping like a rock to the NW, will need to be watched as the system gains more longitude.

FWIW funny that on my last post I was wondering why the models aren't stronger, well the latest GFDL now upto 90kts at 900mbs, so probably 75-80kts at landfall...

[cycloneye]

Brownsville Hurricane Statement

[KWT]

I'd argue it has weakened a bit the last 6 hours to 45 kt, but I doubt the NHC would put that in an advisory if it goes against trends.

Yeah bar that 66kts at FL not much else supports 50kts, indeed 45kts looks good to me given the surface estimates that have been coming in recently and don't look rain contimated.

[Pedro Fernández]

Here is a seedy loop that I have built from NASA hi-re images.

[Air Force Met]

You really think it could be a major AFM??

I've personally been 'forecasting' bout 85-95kts as a peak on the forum I'm on with perhaps a slight weakening due to the large circulation as it drags in slightly more stable air from land, similar effects to Dolly...

Still I think your right, I've been a little baffled why the models have only strengthened this to about 65-70kts, as long as that ULL does move out the way its got time to strengthen quite nicely.

Yes I think it can be a major. If you look at the NHC forecast...they are calling for a 100mph storm 21 hours from landfall...and a 90mph storm 3 hours after landfall. So...is it likely that the NHC is actually forecasting a 100 mph Cat 2 storm for an entire day before landfall with no additional strengthening? Especially given they raised it 25 mph from the previous point.

[Pedro Fernández]

Here is a seedy loop that I have built from NASA hi-re images.

From this loop I can estime the vertical axis which joins the centers of the storm at the different heights is tilted a little to the southwest aprox...

[ROCK]

You really think it could be a major AFM??

I've personally been 'forecasting' bout 85-95kts as a peak on the forum I'm on with perhaps a slight weakening due to the large circulation as it drags in slightly more stable air from land, similar effects to Dolly...

Still I think your right, I've been a little baffled why the models have only strengthened this to about 65-70kts, as long as that ULL does move out the way its got time to strengthen quite nicely.

Yes I think it can be a major. If you look at the NHC forecast...they are calling for a 100mph storm 21 hours from landfall...and a 90mph storm 3 hours after landfall. So...is it likely that the NHC is actually forecasting a 100 mph Cat 2 storm for an entire day before landfall with no additional strengthening? Especially given they raised it 25 mph from the previous point.

they are hedging their bets.....CYA...in layman terms...

[KWT]

The structure is actually really rather good despite the shear, probably holding steady for now I'd imagine, if that shear does ease off though I'm not seeing much out there that'd strengthen the system.

[mvtrucking]

The structure is actually really rather good despite the shear, probably holding steady for now I'd imagine, if that shear does ease off though I'm not seeing much out there that'd strengthen the system.

Did you mean that, if the shear lessens you don't see much out there, to stop it from strengthening?

[TexasF6]

I'm glad a ProMet sees my concern....but hey, I have had the benefit of growing up around ProMets, it rubs off a little. Aside from that, Alex is ramping up....i want a deep storm recon sample before I start believing the models...also, I see the envelop of convection building up and surrounding the core...this is essential to the storm's fortitude and a protection mechanism against shear and mabye a little less vs dry air......

[Sambucol]

Loop: http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... mframes=25

Looks to me like shear is abating as high clouds are starting to build northwestward. Any thoughts on this observation?

All I see is a large area of dry air consolidating and moving into the NW quadrant, which is not going to help Alex.

here is where I am looking to see this- http://www.ssd.noaa.gov/goes/east/watl/flash-wv.html

WV loop: http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... mframes=25

I'm not seeing a big issue with dry air.

A large build up thick, dark clouds have been rolling in from the northwest where I am. It's cloudy here now.

[CourierPR]

I'd argue it has weakened a bit the last 6 hours to 45 kt, but I doubt the NHC would put that in an advisory if it goes against trends.

How did you arrive at that wind speed? Did you take a measurement inside the storm?

[KWT]

The structure is actually really rather good despite the shear, probably holding steady for now I'd imagine, if that shear does ease off though I'm not seeing much out there that'd strengthen the system.

Did you mean that, if the shear lessens you don't see much out there, to stop it from strengthening?

Yes indeed I did mean that, a little typo there!

Still you've got decent heat content, probably an imporving upper conditions (though I'm still totally sold it'll be as favourable as some think.) and generally decent conditions. Once the inflow isn't coming totally off of Mexico then the convection will probably be able to strengthening...in fact its got a double whammy due to the Yucatan as well being close.

[cycloneye]

18z Best Track

Stays at 50kts.

AL, 01, 2010062818, , BEST, 0, 203N, 917W, 50, 990, TS

ftp://ftp.tpc.ncep.noaa.gov/atcf/tcweb/ ... 010.invest

[dixiebreeze]

28/1145 UTC 19.9N 91.7W T3.0/3.0 ALEX -- Atlantic

[americanre1]

With the new convective burst to the north, is there a plausibility that the two burst could cause the center move to the north. I also see a possible new circulation actually to the NE, around 21.5 N and 91.0 W, am I seeing that correct?? Just wondering what is happening with Alex.