6/12/06 FCST: Tropical Storm Alberto

well the tropical season has begun!

Hurricane hunters are on the way, and will be on site in an hour or so.

if this storm survives and becomes a tropical storm, it should recurve towards floridas gulf coast, although I really dont see any opportunity for it to become stronger than a TS before florida... upper level winds do not appear to be that healthy, until it turns more east it will be fighting upper level winds. NHC does indicate a moderate tropical storm for the gulf coast. SHIPS and GFDL are in good agreement for 50 knots at florida impact. After crossing florida the GFDL indicates strenghtening to a hurricane, it will be booking up the east coast so it is possible for those right side winds to be stronger than one would expect from a system over the mid atlantic this early. Because of the strong westerlies still around this will behave more like a late season storm. Although before we get to that it has to stay together in this early stage. IR imagery does show low level cyclonic flow and upper level outflow to the north looks decent, but cloud tops have warmed recently.

looking at the bouys SSTs are in the low 80s in the gulf, and around 80 up to cape hateras, and then rapidly cool north of that.

When the hurricane hunters get there we should have a better idea if it will live or not, or if the center of circulation is in the right area for the latest model runs to be accurate.

EDIT: TS
 
In reference to a couple of now-deleted posts concerning tropical cyclone discussion in the "Chase Forecasts" forum:

<div class='quotetop'>QUOTE("Stormtrack Rules")</div>
(8) A post about any tropical cyclone being monitored by NHC is allowed. One FCST/NOW/REPORTS/DISC thread is allowed per storm. Moderators will adjust the subject line to reflect the latest status and area of the storm. [/b]

Typically, it's best to wait off on starting a FCST or NOW thread until after the storm has been named. However, this one looks like it will directly impact the US, so it's okay now. So, post away!
 
Doug - I'm no hurricane forecaster, so am just curious what makes you believe it has a chance of hitting New Orleans? Seems like it'd never be able to push back against the synoptic flow.
 
TD#1 is a really weak disorganized system and I wouldn't be surprised if it would not make it to tropical storm status. All day there has been multiple centers rotating around a large low pressure system. With the strong shear enviroment the depression is inbedded in that unfavorable flow and will be for the next few days I would expect to see only a sloppy and large low center move over the northern part of Florida with welcome heavy rain fall.
 
We'll take what we can get as far as rain goes here in the Sunshine state. The forest fire situation down here is getting pretty bad. I have to say based on today's satellite imagery and the forecast models calling for this to have a hard time strengthening, i'd have to agree with Jim. I suppose it could reach moderate tropical storm strength before it makes its way across Floridal, but I don't see a high liklihood of anything stronger, but stranger things have happened, so we just have to keep an eye on it the next 48 hours and see what happens. Either way, it looks like FL is in for some rain and that's not bad news.
 
I'm not so optimistic about this one. The satellite presentation this morning is terrible-- very asymmetric-- and in the most recent discussion, the NHC lowered the max intensity forecast to 40 kt and suggested the low-level circulation center might languish and dissipate in the W Gulf, lonely and separated from the deep convection. :( Shear is the headline story with this baby.
 
I notice on the recent satellite frames that there's a solid, persistent burst of deep convection very close to-- apparently just N of-- the circulation center. You can see the system is really "trying" to get it together. If the shear slacked off a little, I'll bet this thing would develop nicely.

Note: This links is dynamic, so the above commentary will no longer apply as the system evolves.
avn.jpg
 
I notice on the recent satellite frames that there's a solid, persistent burst of deep convection very close to-- apparently just N of-- the circulation center. You can see the system is really "trying" to get it together. If the shear slacked off a little, I'll bet this thing would develop nicely.

Note: This links is dynamic, so the above commentary will no longer apply as the system evolves.
avn.jpg

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This mornings visible images show a well exposed low level center near 23.6N and 88.2W but a new center is trying to take shape near a burst of convection near 24.7N and 85.8W. This is a sign of a strong sheard system and will probably continue until landfall.
Jim
 
This mornings visible images show a well exposed low level center near 23.6N and 88.2W but a new center is trying to take shape near a burst of convection near 24.7N and 85.8W. This is a sign of a strong sheard system and will probably continue until landfall.
Jim
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Late update!
TS Alberto has been named although it is still a strongly sheared storm system and very little if any intensification should occur. NHC is tracking the low level center I spoke about in my previous post, I would expect this feature to eventually dissipate and the new center closer to the convectio to become dominate later today.
 
NHC had requested all FL offices and a few along the Gulf Coast to run upperair soundings every 6 hours - they've now canceled that request... Not a good sign for Al!
 
Doug - I'm no hurricane forecaster, so am just curious what makes you believe it has a chance of hitting New Orleans? Seems like it'd never be able to push back against the synoptic flow.
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Last night the center was making a drunken wobble and I was watching the storms brewing off of Tampico Mexico which looked as if the ridge was retreating and convection was going to wrap around the center today. With that convection 24 hours ago in my previous post it was a sign that the sheer was not all that and was moving northward, at least that is the way it looked to me. That convection to it's west was moving WSW which has me wondering and still keeping an eye on it as well as the new convection off the Yucatan. In the latest NHC forecast, they are reporting the ridge had in fact moved northward.

The movement of the center was still north last night and through today but now I'm not sure if it can make it that far or at all now as anything more then a TD. The vis-sat showed a somewhat defined eye that was very far from the deep convection that was coming on shore over the west cost of FL. The GFDL now shows this is gaining strength but I don't trust that data that much for the strength when all the other models show it falling apart. The MM5 shows this system moving north into the NOLA area still CMC has it moving more north then turning into FL around the Panama City area. The ridge has retreated as of the 10pm NHC but it is still a crap shoot as the GFS shows this thing dying off tomorrow. NoGaps is still showing this moving north. The track is still towards the north but it could shoot off to the north east at anytime in the next 24 hours and kind of looks like it might take the turn tonight.

What really has me saying Hmmmmmm is that next huge area of convection kicking up over the Yucatan. Is that going to stay with Alberto or go off on it's own? And on that WV-sat it shows a nice push coming out of the south to hopefully kick this system out fast.

Gulf WV Sat Loop
 
There has been a recent blow up in convection in the last few hours and the convection has built westward some.

Lastest (4AM CDT) NGC advisory has the storm up to 50 mph.
 
The next hurricane hunter has just passed what could be a LLC at about 26.5N 87W. The strongest convection is still sheared off to the east, with no strong winds near the center. The strongest winds are displaced 45-50nm east it seems. As long as the storm doesnt turn east, I think this sheared state will persist.

The models are in better agreement about a track more north/northeasterly, and the more northerly it goes the more it will fighting those upper level westerlies.
 
The convection has flared up impressively this morning, although the LLC is still exposed-- or perhaps at the very W edge of the convection. Still, this is an improvement over yesterday, when the center was hundreds of miles removed from the convection.

Furthermore, I notice on a recent composite radar loop of the Gulf that a vigorous convective band to the N is trying to wrap around the center. This system is really fighting the shear, I'll say that much.
 
b8yr.gif


74 knots at about 3000 feet.

looking rather more healthy that I expected...note how it appears the center may be reforming closer to the convection and stronger winds to the east.

that supports a 55-60 knot tropical storm.
 
b8yr.gif


74 knots at about 3000 feet.

looking rather more healthy that I expected...note how it appears the center may be reforming closer to the convection and stronger winds to the east.

that supports a 55-60 knot tropical storm.
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NHC has just posted hurricane warnings for portion of the upper west coast of Florida as Alberto has increased to 70mph and a pressure of 997mb.
The storm has moved on a more NE course so that has negated some of the shear and as let the convection develop closer to the center.
 
Thinking of maybe heading more north west from here (Orlando metro area) to check this thing out. It looks like an early hurricane may be in store for Florida again…..I suppose one would not have to go to far west from hear as most of the nasty weather is on the east side of the storm…
 
b3lc.gif


the center has certainly reorganized properly... its in the middle of the stronger winds and very near the deep convection if you compare the lat long to satellite.
 
I've been watching an interesting little vortex, perhaps left over from the old circulation center, that has been tracking south all day away from the main circulation center of Alberto. It's even had some intermittent convective bursts go up near it, only to be quickly sheared off to the NE. You can see it particularly well at this site:

http://weather.msfc.nasa.gov/GOES/goeseastconus.html

Choose an animation loop length of 25 or so and make sure you click on 100% quality in the drop-down list. Then choose medium or high magnification and click on Alberto. The site's been a little slow today, but in my opinion this is the best satellite site out there for quality of images and frequency of images in an animation (I think they even go rapid scan when it is available), with the ability to zoom in anywhere on a point of interest.
 
I have two seemingly naive questions I'm going to post to this thread since it seems the forum rules mandate it be put here as it's a current event.

***There is a bow echo that has formed around Orlando in the immediate wake of a rainband. The movement of the bow was about 330/60 while the rainband appeared to be moving closer to 000/50. The bow briefly intensified then suddenly faded away. I was surpised to see a bow echo in an area where I thought subsidence would have been favored. I should have caught a screen cap, but by the time I thought about it, it was too late and the bow was mostly gone. Did anyone else see this? Thoughts?

***There is a frontal boundary moving SSE out of GA currently. In the next 12-18 hrs the first rainbands from TS Alberto are forecast to collide with this front. I've not seen fronts directly interact with rainbands before (mostly I think because I've not usually been geographically close to this kind of interaction--usually I'm just embedded in the TS or Hurricane well away from the fronts). Would this serve as a focus for severe weather (with significant intensification of convergence before they collide)?

For the first storm of the season, I'm fairly concerned to see the intensity of Alberto. The Gulf temps were warmer last year, but we haven't even hit summer. Very worrisome.
 
In the next 12-18 hrs the first rainbands from TS Alberto are forecast to collide with this front. I've not seen fronts directly interact with rainbands before (mostly I think because I've not usually been geographically close to this kind of interaction--usually I'm just embedded in the TS or Hurricane well away from the fronts). Would this serve as a focus for severe weather (with significant intensification of convergence before they collide)?
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Jason, I know I'm not qualified to answer your first question, but share an interest in your second question. The models seem to show the tropical low interacting with the stationary front over the next 48 hours, which should enhance convergence. Not sure about outright severe effects, but definitely concerned about heavy precipitation inland. Also, if the actual track is just a tad more north of current forecast, upslope flow could enter into the equation. Tropical systems bumping up against the Appalachians are notorious for producing extraordinary rain and flooding events.

It was interesting here today in Charleston, SC....just a bit too far south of the base of the upper trough and surface front, as the convection fired north and west of here. Thought the sea breeze boundary (which has been fairly strong over the last few days) might provide some focus for convection, but the cirrus from the tropical storm approached by mid-morning - and has steadily thickened through the day - keeping temps over the land down. Air down here has a very, very tropical feel, more like mid-August than mid-June. Now, this evening, just noticing some low level, scuddy clouds moving up from the south. Very interesting system to follow from this vantage point; will be interested to read any other replies to your forecast questions.
 
The storm has made a fairly significant wobble/turn to the north now. movement looks to be almost due north at this time. This is judging from a zoomed in IR sat and TLH 88D analysis.

Also, weak/shallow convection is making an effort to wrap back around the center. If this does happen or if there is a nice convective blow up near the center, the deeper flow will again act to steer Alberto more to the east. .

I know a few chasers are in Cedar Key, Looks like that's gonna be a precip-free wind event now. Fun to play in but probably not what some had in mind. I'd roll up the coast some if at all possible towards but not quite making it to TLH.
 
There may be one more flare-up in the works, but the very dry air right over the center of the storm doesn't bode well for any strengthening. In addition, operational models (e.g. NAM, GFS, etc) strengthen the 250mb flow over the area through today as a trough in the central Gulf deepens a bit. The very dry air (http://www.ssd.noaa.gov/goes/flt/t1/wv.jpg ) and likelihood that the shear won't decrease makes me think that Alberto may have hit it's peak intensity yesterday. The storm has looked rather marginal for most of it's lifetime, save the brief flare-up in convection that occurred yesterday early morning.
 
Looking at the satellite imagery last night and this morning, I think it's over for this system. The inner core has no convection-- zero-- and it's taking on an extratropical appearance. (I guess I'm stating the obvious here.)

The water vapor imagery (below) is particularly telling. I have never seen a tropical cyclone with such a bone-dry core. That dry air just blasted right into this thing like a battering ram.

It's a disturbing and graphic image of a tropical cyclone's demise. :p

Note: This links is dynamic, so the above commentary will no longer apply as the system evolves.
wv.jpg
 
Interestingly, some good convection is suddenly firing up very near the LLC-- perhaps due to land interaction.

Of particular interest is the strong convective band wrapping completely around the W side of the center, which is clearly visible on Tallahassee radar. It's interesting because this system has been unable to achieve that during its whole lifecycle. In fact, this convective flare-up at the core makes Alberto looking quite a bit more tropical this morning versus last night.

Either way, the center is a few hours from landfall, and I would be surprised if the winds got up to 65 kt before then.
 
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