2013 Steering Pattern / Early indicators

[cycloneye]

As the title of the thread has the word early,that is why I am making this thread in Mid January. This topic is important to have this early to see how things are evolving in the important factor of the steering as we will see based on that which areas in the basin may have visits of tropical systems. Also,it will be important to see how the pressures will be and how the waters are in terms of being more warm or not. Let's see how things will evolve in the next monthly updates as is early in the game.


http://www.ecmwf.int/products/forecasts ... e%20mean!/

ECMWF ensemble mean January update for May,June,July has normal pressures in most of the Atlantic and Caribbean.



ECMWF operational January update for May,June,July has higher pressures in most of the basin.



ECMWF Sea Surface Temperature Anomalies for May,June,July has normal sst's in most of the basin except in the Gulf of Mexico where they are above normal.

[TropicalAnalystwx13]

Yeah, and the ECMWF also predicted a full-fledged El Niño (1.5 °C+) with unimaginably high pressures across the Atlantic the same time last year.

Don't expect this to come true. Especially if the NAO phase this winter is a harbinger (which it usually is). NAO has been mainly negative this winter, meaning it should flip to positive (strong high pressure) for the Spring, and back to negative (weak high pressure) for the Summer.

[cycloneye]

Here is a comparison of the sst's between 2012 and 2013. Notice the difference in the GOM on the loop current extension that is bigger in 2013.

2012



2013



Closeup loop of Gulf of Mexico.

[cycloneye]

Here are the sst anomalies in the whole basin and for being January they look pretty warm with some areas well above normal. Let's see how this factor will continue to evolve in the next few months to see if it will continue this way or not. This is on January 12.

[cycloneye]

SST anomalies as of January 19 continue to show a warmer than average MDR and GOM. Also,the North Atlantic continues to be with very warm anomalies.

[cycloneye]

Another factor that will be important to watch will be the inestability in the Atlantic,Caribbean and Gulf of Mexico.Depending on how high or not the inestability will be,we will see more stronger storms.



http://cat.cira.colostate.edu/

[cycloneye]

Something that will be important to watch in the comming months will be the TCHP.Here is a comparison between 2012 and 2013 on January 24.

[Hurricane Andrew]

Again, I say Hurricane Withdrawl.



JK of course. I miss the tracking days too.

[cycloneye]

Again, I say Hurricane Withdrawl.



JK of course. I miss the tracking days too.

Time goes by so fast that without noticing the season will be here. The big questions are how active the season will be and how will the U.S fare in terms of landfalls and that is why this thread is made to look at the factors that will answer those questions.

[Hurricane Andrew]

Based on how the SOI has acted this winter, are there any analogs?

[cycloneye]

The next ECMWF Mean Sea Level Pressure (MSLP) update will be released on the 15th of Febuary. Let's see if it continues to show Higher pressures for most of the North Atlantic basin as it had on the January update and posted at the first post of thread.

[cycloneye]

The vertical inestability as mentioned before in the thread will be important to watch. Here is the link where you can scroll down to see the graphics about that.

http://www.ssd.noaa.gov/PS/TROP/TCFP/atlantic.html

[NDG]

Yeah, and the ECMWF also predicted a full-fledged El Niño (1.5 °C+) with unimaginably high pressures across the Atlantic the same time last year.

Don't expect this to come true. Especially if the NAO phase this winter is a harbinger (which it usually is). NAO has been mainly negative this winter, meaning it should flip to positive (strong high pressure) for the Spring, and back to negative (weak high pressure) for the Summer.

I disagree with you, the NAO so far this meteorological winter has been at least neutral if not slightly positive so far.

Edit: I just realized that you posted your comment regarding the NAO 3 weeks ago.

[NDG]

The vertical inestability as mentioned before in the thread will be important to watch. Here is the link where you can scroll down to see the graphics about that.

http://www.ssd.noaa.gov/PS/TROP/TCFP/atlantic.html

Could this be the 4th year in a row that instability will be lacking in the tropical Atlantic? We hope so, and it could make a big difference like the last couple of years.
I am starting to firmly believe that the lack of a any moderate to strong El Ninos during the last few years might have something to do with instability lacking in the western Hemisphere, IMO.

[wxman57]

Here's the Gulf of Mexico instability graphic for 2012. You can take off the image name at the end to get to the root folder of all 2012 files. The instability graphics end in "...ins.gif". As has been the case for the last several years, all parts of the Atlantic were more stable than normal (less instability). The lack of instability doesn't appear to affect the number of named storms, but it definitely appears to affect the intensity of the storms that develop. Only 1 major hurricane last year (possibly 2 with Sandy near Cuba). However, the more stable atmosphere could have played a part in the development of rather large but weaker hurricanes like Isaac and Sandy. Both of these storms lacked any very strong wind, and hurricane force winds were confined to a very small area. However they both had a very large area of TS winds that resulted in an extensive storm surge.

Question is - will the reduced instability (more stable air) continue into the heart of the 2013 season?

ftp://rammftp.cira.colostate.edu/schuma ... gmxins.gif

[Hurricane Jed]

GOM has been quiet the past 4 seasons. Ida 09, Alex 10, Karl 10, Nate 11 and Isaac 12 have been the only GOM hurricanes. Ida transitioned before landfall, the next three affected Mexico primarily. Isaac was large but weak. I don't feel like that kind of luck is going to last.

[cycloneye]

The North Atlantic in general continues to look above normal in the anomalies.

January 19



Febuary 9

[cycloneye]

Here is the Febuary update from ECMWF of the MSLP for June,July and August and still shows higher pressures for a good chunck of the Tropical Atlantic and Caribbean,although less than last months update as you can see at the first post of thread.

Operational ECMWF



Ensemble Mean



SST Anomalies forecast for June,July and August.

[wxman57]

Last year at this time, the forecast was for much higher pressures than the current forecast for JJA. Still somewhat unfavorable for development in the Caribbean and MDR.

[cycloneye]

Last year at this time, the forecast was for much higher pressures than the current forecast for JJA. Still somewhat unfavorable for development in the Caribbean and MDR.

I think vertical instability goes on hand with the MSLP as higher pressures and lack of mid-level moisture is not a combination that tropical cyclones like. Let's see what occurs in the next 2-3 months with both factors.