Atlantic Tropical Action 2013

[NJwinter23]

Did CTBlizz lock it up yet?

 

Havent checked over there in a while...hes been locking in above normal temps and humidity in new england for August last I checked.

[wxmx]

I tend to agree with Adam about that if anything develops in the NW Caribbean/GoM, it will probably be a weak TC, with little chance to reach hurricane status. And this is not because the atmosphere will be particularly hostile. Actually it looks decent, my reasoning is because it looks like a rather complex setup, both near the surface with the energy having a hard time consolidating, and the steering currents being rather complex. First going very near land in the W Caribbean and over land for the Yucatan, and then because it looks like the steering currents might collapse when the disturbance supposedly is in the GoM...interaction with the passing trough and ridging weakening is uncertain.

[Ed Lizard]

Easily found, about half the individual GEFS ensembles have 1008 mb or lower pressure in the BoC or Western Gulf, two of twenty are 996 mb or below.

 

15 km FIM still onboard, and a quick look at the Euro, it tried to develop something but a Southern track through Central America/Yucatan and Southern BoC.  Hour 168 the optimisitc FIM is similar longitude to Euro, but at a better latitude and with less land interaction, and hence has a TD bordering on a TS.

[wxmx]

Being said that, there's no real reason behind it can't get to hurricane status and beyond if it gets it's act together rather fast in the GoM (or even better in the NW Caribbean), for example, if it's a 40kt TS around 92W with >-70C cloud tops near the center. But so far, no models show other than gradual developing.

 

What I mean is there's no forecasted wall of shear and actually models consensus is for an upper air anticyclonic setup.

[am19psu]

Being said that, there's no real reason behind it can't get to hurricane status and beyond if it gets it's act together rather fast in the GoM (or even better in the NW Caribbean), for example, if it's a 40kt TS around 92W with >-70C cloud tops near the center. But so far, no models show other than gradual developing.

 

What I mean is there's no forecasted wall of shear and actually models consensus is for an upper air anticyclonic setup.

Yeah, the setup looks like another land interaction, large R34, monsoon slopgyre setup. Blah.

[Ed Lizard]

I tend to agree with Adam about that if anything develops in the NW Caribbean/GoM, it will probably be a weak TC, with little chance to reach hurricane status. And this is not because the atmosphere will be particularly hostile. Actually it looks decent, my reasoning is because it looks like a rather complex setup, both near the surface with the energy having a hard time consolidating, and the steering currents being rather complex. First going very near land in the W Caribbean and over land for the Yucatan, and then because it looks like the steering currents might collapse when the disturbance supposedly is in the GoM...interaction with the passing trough and ridging weakening is uncertain.

 

 

Other than land interactions, at hour 192 GFS shows a 200 mb anticyclone aloft, decent 700 mb relative humidity, somewhat dry to the West at 500 mb, but I'd like to think relatively high TCHP would give it a shot to strengthen beyond the 1008 mb low the GFS has at the truncation.  And also feeding my natural optimism, 10% of the ensembles develop a sub-996 low, which would seem to suggest at least some support for a hurricane.

 

In this lame (to date) hurricane season, one eyed man being king in the land of the blind, a sprawling, poorly organized storm, if it can landfall close enough to the border, would be a good thing.  And if it turns out more like a Dolly Cat 1 or Cat 2 chaseable storm near the border, well, I remember Dolly raining on my yard as well.

[wxmx]

Yeah, the setup looks like another land interaction, large R34, monsoon slopgyre setup. Blah.

Land interaction and competing low level energy are the main concerns with this. If it can overcome those two (Yucatan interaction being a given)...it has a chance.

[am19psu]

Land interaction and competing low level energy are the main concerns with this. If it can overcome those two (Yucatan interaction being a given)...it has a chance.

Sure, I guess. But this screams Vmax = 50 kt, R34 = 150 nmi to me.

[am19psu]

Sure, I guess. But this screams Vmax = 50 kt, R34 = 150 nmi to me.

If it forms at all. Let's not kid ourselves, this is probably <30% to even get named at this point.

[CoastalWx]

It's so boring that we might have to post the NAM for the weenie low south of Brownsville.

[wxmx]

Sure, I guess. But this screams Vmax = 50 kt, R34 = 150 nmi to me.

No Diana '90/Gert '93/Alex 2010? (not forecasting that, just some track analogs) Some to lots of land interaction, but given time and very good upper level conditions, and some consolidated energy to start with, and it can go bonkers.

[wxmx]

If it forms at all. Let's not kid ourselves, this is probably <30% to even get named at this point.

Yes, I'm assuming that as well when I said this is probably no more than a low/mid end TS. Chances are that it won't get to anything even numerable.

[wxmx]

Actually I have found that some land interaction might be a positive (especially flat land like Florida or the Yucatan) when dealing with messy stuff.

[Mike.Ventrice]

I have to say, minus the part that the CCKW propagates poleward with time over the sahara.. I kind of am happy with this!

 

http://vimeo.com/72062097

[CoastalWx]

I have to say, minus the part that the CCKW propagates poleward with time over the sahara.. I kind of am happy with this!

 

http://vimeo.com/72062097

 

Is that your influence?     Nice to see some science on there.

[Mike.Ventrice]

Is that your influence?     Nice to see some science on there.

 

Maybe....

[Ed Lizard]

It's so boring that we might have to post the NAM for the weenie low south of Brownsville.

 

That reminds me, I believe it was right at a week or 8 days ago I went one eighth glass full optimistic on a lemon because of the model forecast of a retrograding upper low, even though the Euro never showed it becoming warm core.  Sufficient blobbage in the Gulf I'm keeping that at the  1/16th chance of a lemon I dropped it to yesterday, because any blob near land that persists for a few hours could trigger a 0% lemon.

 

About the Caribbean-Yucatan-BoC system, I'm sticking to my guns.   I'm three eights full optimistic on a mandarin day 5 or 6, and glass quarter optimistic on a cherry or TD day 6 to 7 in the SW Caribbean/Yucatan area.  Mild GEFS and GFS support, with continued FIM support, I'm not backing down.

[Levi32]

The MJO signal is at very low amplitude right now. The GFS continues to over-forecast amplitude in phases 8 and 1, while the ECMWF mostly keeps the lid on it. This will make it less of a factor in convective activity overall. Now that we're getting into late summer and the NHEM continents are starting to cool off, I think the global SST anomaly configuration will cause a ramp-up in Atlantic activity, regardless of the MJO. With the northern Indian Ocean frigid for this time of year and a cool eastern equatorial Pacific (hey CFS and ECMWF, where's that El Nino you forecasted to appear in July/August?), convective activity is favored to increase over the tropical Atlantic, where waters are still anomalously warm. You might say the convection could head over to the western Pacific, but that basin remains amazingly quiet so far relative to normal, as it has been for a few years now. A La Nina-ish pattern historically doesn't favor the WPAC anyway, for various reasons. It's hard to see an Atlantic hurricane season that's not more active than normal coming out of this pattern. It's the most favored basin for anomalous TC activity going into autumn.

 

[WNash]

one eighth glass full optimistic on a lemon... 1/16th chance of a lemon... three eights full optimistic on a mandarin... glass quarter optimistic on a cherry

Would you walk me through your probability system here?

When you say there's something like a "1/16" chance (or 1/32 or 1/64 or 1/256 or 1/some other power of 2) of a "lemon"/"mandarin"/"cherry", are you saying there's a 6.25% chance of development in a given area into a TD/TS/hurricane? Or is that your probability that the NHC will make a development probability call for that area in a time frame, meaning that the actual probability call you're making on 1/16 of a chance of a lemon is maximally a 1.875% chance of tropical development? That's basically statistical noise as far as I can tell.

I know there's not much going here but these posts are probabilities of probabilities, and it's almost unreadable. Is there a way to express this content more meaningfully?

[Ed Lizard]

Would you walk me through your probability system here?

When you say there's something like a "1/16" chance (or 1/32 or 1/64 or 1/256 or 1/some other power of 2) of a "lemon"/"mandarin"/"cherry", are you saying there's a 6.25% chance of development in a given area into a TD/TS/hurricane? Or is that your probability that the NHC will make a development probability call for that area in a time frame, meaning that the actual probability call you're making on 1/16 of a chance of a lemon is maximally a 1.875% chance of tropical development? That's basically statistical noise as far as I can tell.

I know there's not much going here but these posts are probabilities of probabilities, and it's almost unreadable. Is there a way to express this content more meaningfully?

 

 

Oh dear.

 

Back in college, one learns that an engineer, when (s)he solves a problem, must express uncertainty when certain factors that are used to solve the problem have inherent uncertainties.  An object may be 2 meters long, but have a +/- mm potential measurement error.  Something may be 3 Kg, plus/minus 2%.  Even freshman classes, woe to the student who gives an answer that has more 'significant figures' than the least precisely expressed term.  Senior year and beyond, to quote Donald Rumsfeld, there are things you know, things you don't know, and things you don't know you don't know.  Things like Monte Carlo simulations, answered expressed in terms of 10% likely, 90% likely, most likely.  I believe ensemble modeling in weather is a way professional weather people deal with things they know they can't know.  But, anyway, engineers, always design in a safety factor, because there is always a chance a structure designed to carry a specific load, well, has some defect.

 

Getting back to professional mets, to quote the Storm2K required disclaimer, lest somebody read an amateur forecast and decide not to evacuate, I am not a degreed or professional met.

 

Glass half full, and variants of, can I really give a 7.5% probability that the NHC will declare there is a near zero to 20% chance of TC development in 48 hours.  In engineering terms, it is a 'SWAG'.  It is a general reflection of my naturally optimistic nature, and not meant as the AccuWx 45 day forecast for planning your first Saturday of September outdoor wedding.

 

6Z GFS ensembles with ensKF filtering, well, that looks between 5 and 10% on a TC... 18Z GFS no fun, but 18Z GEFS have a few interesting members.

[WNash]

Ok, I'm not looking for an "AccuWeather 45 Day Forecast." Just to make that clear. Don't know if you're being high-handed there, but let's rule that out.

I thoroughly understand and appreciate your point about uncertainty. My background is data analysis, and I've had to translate confidence intervals in stuff I've had to write for upper management types without stats backgrounds. I was just asking if there's any significance to your finely detailed gradations of distant probability, 1/256th etc., on top of NHC mandarin probabilities.

I don't think you answered that directly, but that's totally fine. You're noting areas to watch on models before the NHC's window. Given that there's sweet fanny adams to talk about this season so far, I get that keeping it entertaining keeps tropics watchers from dozing off from boredom. So I'll take it in that spirit.

[Ed Lizard]

^^  I lay off the small talk and happy chatter when stuff starts happening and the pro-mets and more informed amateurs start posting.

[Sunny and Warm]

Ok, I'm not looking for an "AccuWeather 45 Day Forecast." Just to make that clear. Don't know if you're being high-handed there, but let's rule that out.

I thoroughly understand and appreciate your point about uncertainty. My background is data analysis, and I've had to translate confidence intervals in stuff I've had to write for upper management types without stats backgrounds. I was just asking if there's any significance to your finely detailed gradations of distant probability, 1/256th etc., on top of NHC mandarin probabilities.

I don't think you answered that directly, but that's totally fine. You're noting areas to watch on models before the NHC's window. Given that there's sweet fanny adams to talk about this season so far, I get that keeping it entertaining keeps tropics watchers from dozing off from boredom. So I'll take it in that spirit.

That would be correct, although I believe he overdoes it.  Sometimes, less is more.

[Ed Lizard]

That would be correct, although I believe he overdoes it.  Sometimes, less is more.

Yeah, always been my problem,  trying too hard to be a cheerleader.

 

Weenie is a dirty word around here, but I watch TWC shows on Sandy and Andrew.  I watch YouTubes about Charley, Sandy, Iniki,  multi-vortex tornadoes.  Boxing Day.

2009, Summer w/o a beach party, I realized, for home use, one doesn't want more than a low end Cat 1 locally.  A Cat 2 on the coast almost 60 miles away, doesn't sound bad, but actually, yes, it is.  Just Cat 1 winds in the neighborhood, and that breaks things.  Toppled gas station awnings were cool, however.

 

 But low end hurricanes and tropical storms (rain for the lawn), 2008 and 2009 December snow miracles, a solid inch in 2009.  (2004 Christmas Eve Snow Miracle, didn't stick, but it snowed on Christmas Eve!!!)  Florida has building codes, flat topography, good highway network,

 

I'm Ed, and I am a weenie.  Ask Steve, at the KHOU-TV 11 local forum, I almost need to be tied down, I get so enthusiastic.

 

Speaking of, 18Z FIM, barely a TS, but at least a day to landfall, good moisture, developing East side outflow channel, I think Potential_Erin could be a solid Cat 1 before Vera Cruz or Tamps. landfall.  OT, church my wife was baptized in in Ordaz, at least 100 km inland., sign in Spanish, it is a hurricane shelter.  San Miguel Arcangel in Ordaz.  Where mis suegros got married.  Been there back when Americans could go to Mexico.

 

yes, I know GFS has two tepid runs in a row, but dang, has the 30 km and 15 km FIM been consistent for what was hour 168, then hour 144, now hour 120.  And if it is only a 50 knot broadly defined TS that can landfall in La Pesca but rain in Houston, I'll deal.

 

 

 

ETA:

 

 

Review of 0Z models, my weenieism, may not pay off, models trending  South/too much land interaction for significant development, Euro should be coming on board inside five days, and it almost tries 72 & 96 hours, but...  Voices of moderation and may prevail on this one.  Looking at NCEP GFS 4 panels at hour 192, if not for being so deep in the BoC this could have been a contender.  GFS beyond truncation tries to gain some latitude, but too late, too close to land, too far South for my lawn.

[bluewave]

I think that we'll have to wait until August 20 and beyond for a strong enough Cape Verde

storm to survive the stable conditions to the west better than Dorian did. We will probably

fall into the latest first hurricane of the season group since the active phase began in 1995.

 

Lastest first hurricane of season since 1995:

 

 

8-22-11

9-11-02

9-09-01

8-21-99

8-22-98

 

 

[uncle W]

I think that we'll have to wait until August 20 and beyond for a strong enough Cape Verde

storm to survive the stable conditions to the west better than Dorian did. We will probably

fall into the latest first hurricane of the season group since the active phase began in 1995.

 

Lastest first hurricane of season since 1995:

 

 

8-22-11

9-11-02

9-09-01

8-21-99

8-22-98

 

 

ts_al_tat_THDV.gif

 1964 had their first hurricane develope on 8/20...Cleo reached a cat 4 and tracked over eastern Florida and Georgia...that was the first of six hurricanes that were a cat 3 or higher...

[wxmx]

As expressed in my thoughts a week ago, there's a surface trough associated and interacting with the ULL in the GoM. It gained lemon status but will be ashore in a day or so. Conditions are marginal with the ULL so close behind. 06z GFS is interesting with the NW Carib/ GoM thingie in a few days, but it's very low latitude, trough isn't as deep as it was a few runs earlier. Very good conditions aloft, but little real estate.

[Eyewall2005]

Want some frances type tracks in a few weeks.. Is the atlantic even capable anymore of producing some real bonified cv storms :0(

[GaWx]

Want some frances type tracks in a few weeks.. Is the atlantic even capable anymore of producing some real bonified cv storms :0(

 

 Watch out for what you wish. You may eventually get more than you want. The analogs I've seen suggest a strong chance for a major H hit on the US somewhere this season. The east coast of Florida is one area who's chances seem to be enhanced most relative to avg. climo.

[Ed Lizard]

As expressed in my thoughts a week ago, there's a surface trough associated and interacting with the ULL in the GoM. It gained lemon status but will be ashore in a day or so. Conditions are marginal with the ULL so close behind. 06z GFS is interesting with the NW Carib/ GoM thingie in a few days, but it's very low latitude, trough isn't as deep as it was a few runs earlier. Very good conditions aloft, but little real estate.

My natural optimism probably won't work out on either a local rainmaker or a chase-worthy storm.  But my optimism on a Gulf lemon from over a week ago has at least been rewarded.

 

BTW, I think it runs out of time, but the upper low in the middle of the Gulf is a more interesting feature than the actual lemon.  CIMSS suggests it has started to work down to 700 mb.  It should be inland within 2 days and won't have time to get too interesting.