2013 Steering Pattern / Early indicators

[blp]

This should probably be in another thread. There used to be a thread for personal forecasts.

This is my hurricane strike probability map for 2013.

[]http://img838.imageshack.us/img838/8666/58498612.png[/img]

Since they're not colored...

The Bahamas - High chance
Lesser Antilles - High (North), Medium (South)
Bermuda, Azores, Cape Verde Islands, Newfoundland - Medium

Be prepared for every season regardless of the forecast.

you might as well color all that in red and call it a day....

you gave the entire Texas coast 0-20% chance. You do know that Texas has a big coast line? If we are using 2004-2005 as comparable years then I would change this map. Just sayin if you look back at those years.

My forecast was not based solely on analogue years. It takes into consideration long range model guidance for 500mb geopotential heights and forecasts from many different branches of NOAA regarding the development of the pattern for this summer.

[cycloneye]

This is important to be posted on this thread because this strong MJO pulse that will roll thru the Pacific may have the punch to favor TC developments in the EPAC as well in the Western Caribbean by late May going into early June. Time will tell so stay tuned.

[blp]

The NAO looks to stay quite positive for the first half of this month. Both GFS and ECMWF agree and this has lead to the SST's dipping a little. If this keeps up we may see a few more dips.

ECMWF


Uploaded with ImageShack.us

GFS


Uploaded with ImageShack.us

SST's


Uploaded with ImageShack.us

[blp]

I am curious on anyones thoughts on the strong jet stream pattern we have seen parked over the midwest and how this might effect the hurricane season. It has been unusally strong and persistent.

[chaser1]

I am curious on anyones thoughts on the strong jet stream pattern we have seen parked over the midwest and how this might effect the hurricane season. It has been unusally strong and persistent.

You must have been reading my mind LOL For the last day or two I had meant to post a similar question regarding the roaring 200mb winds. For some time know, I too have noticed how the 200mb flow has quite stubbornly remained fairly strong & quite zonal across the southern tier of the U.S. My best recollection for prior Spring seasons, were that this flow eventually became more meridional to more closely follow the overall long wave pattern. In some cases I thought that past years might have had a more pole-ward direction of such winds, regardless whether this northward bend might have occured west or east of Florida. What seems particularly odd is not the strong low latitude zonal flow which seems to want to traverse Florida's general latitude, but especially how this feature simply continues eastward from there. To me it almost resembles prior El Nino year subtropical westerlies, but at a seemingly higher latitude for such sub-tropical UL winds. On the other-hand, one could say these present winds resemble a somewhat "winter-like" southerly surge where such stronger zonal flow across the U.S. might not be all that odd -if occurring during winter.....

Either way, such conditions would seem to indicate two conditions which if persisted would have a distinct impact on the upcoming hurricane season. First off, such strong upper level shear would seemingly mitigate top end intensity (or at least at the point where tropical cyclones eventually started to gain latitude). I think the other impact could be some added atmospheric stability caused by relative cooler/dryer air that would filter a bit farther south and east than normal. Obviously these and most large scale conditions are likely to simply evolve as the seasons progress, but how soon and how drastically?

So, here's my "anomalous" question to any Met that might either recollect prior years better than I (or simply have easy access to archived 200mb wind patterns for any number of prior seasons). Do the present upper level conditions actually represent a more southerly surge of westerlies than what we might see this time of year? Of even more interest to me however, is whether past year data would or would not indicate that a far more eastward extension of these strong upper level winds that we are seeing, are truly anomalous to "the norm"?

[weatherwindow]

This is important to be posted on this thread because this strong MJO pulse that will roll thru the Pacific may have the punch to favor TC developments in the EPAC as well in the Western Caribbean by late May going into early June. Time will tell so stay tuned.

http://oi40.tinypic.com/3g87p.jpg

Good morning, Luis...the projected MJO pulse may coincide with another strongly positive element which may enhance the overall possibilities of early season Western Caribbean development. Typically, the ITCZ, between 75 and 83deg West, remains south of 10deg North or south of the isthmus of Panama. However, on occasion, longwave patterns and lowering pressures in the Caribbean result in a northward kink or drift to a position north of Panama. This induces a monsoonal circulation or trof in the Western Caribbean. Such a circulation is normally strongly favorable for development due to the enhanced SW inflow. The long range CFS model for early to mid June suggests this possibility. http://www.weatheronline.co.uk/cgi-bin/ ... RES=0&WMO=

[Hurricaneman]

The MJO phase is the 1-2 area as seen with the African convection and heavy convection in the western Indian Ocean which is unfavorable for the atlantic, but should return to phase 7-8 at the end of May and Early to mid June so May 28th through June 10th should be the time to look for tropical development

[cycloneye]

It would be a very favorable enviroment with the shear not strong for systems to develop in the MDR area if it stays like this.



But on the other hand the Vertical Instability continues below average.

[cycloneye]

To add to what I posted above,in the Caribbean the Vertical Instability is below climatological standards at this time.

[Hurricaneman]

I'm thinking the decreased instability is co located with the unfavorable phase of the MJO because every time I see the MJO in phases 6.5 and 1.5 the instability goes way up to above normal and the last few seasons the MJO has rarely gotten into these phases which led to below normal instability.

The MJO is in phase 2 which is going to decrease the instability over the atlantic

[OuterBanker]

Cool blocking highs Mar to May in 50's. Let's just hope history doesn't repeat itself.

https://twitter.com/BigJoeBastardi/stat ... 09/photo/1

[cycloneye]

This is the GFS Ensembles forecast of the MJO until May 22nd and shows the progression of this strong pulse. I would watch for early TC development in EPAC or somewhere in the Atlantic Basin by late May or in the first week of June. Soon enough I think the global models discussion thread will have posts about models sniffing at developments. We will see what occurs.

[cycloneye]

To reinforce what I said in above post,here is the updated MJO forecast from the GFS ensembles that ends on May 23rd.

[cycloneye]

Here is a video made by Levi Cowan regarding what it has been posted in the last few days about the strong MJO pulse and maybe causing early TC developments in the EPAC or Caribbean by the end of May or first week of June. He also talks about the season but without any updated numbers than the ones he had in the March forecast (Between 14-16 named storms)

http://www.tropicaltidbits.com/blog/201 ... this-year/

[SFLcane]

luis can you post direct link to these mjo maps in levis site.

[cycloneye]

luis can you post direct link to these mjo maps in levis site.

I think you mean this.

http://www.tropicaltidbits.com/analysis/models/

[SFLcane]

luis can you post direct link to these mjo maps in levis site.

I think you mean this.

http://www.tropicaltidbits.com/analysis/models/

yea but cant find the CFS and MJO maps

[cycloneye]

luis can you post direct link to these mjo maps in levis site.

I think you mean this.

http://www.tropicaltidbits.com/analysis/models/

yea but cant find the CFS and MJO maps

He will include them very soon after the exams.

[JonathanBelles]

The Countdown Is On! My thoughts on the rest of May, and a bit of news: http://jonathanbelles.wordpress.com/201 ... own-is-on/

[TropicalAnalystwx13]

Here is a video made by Levi Cowan regarding what it has been posted in the last few days about the strong MJO pulse and maybe causing early TC developments in the EPAC or Caribbean by the end of May or first week of June. He also talks about the season but without any updated numbers than the ones he had in the March forecast (Between 14-16 named storms)

http://www.tropicaltidbits.com/blog/201 ... this-year/

He reiterated what's been said by many over the past few weeks: everybody this season is at risk, especially the Greater Antilles and East Coast. Active season w/ above-average ACE and a strong Cape Verde season.