2013 Steering Pattern / Early indicators

[Hurricane Andrew]

And JB is trustworthy why...?

[ninel conde]

And JB is trustworthy why...?

well he was hyping how favorable the 400 mb was back in march and now he has backed off that. this picture of the SAL may back him up a bit. the SAL isnt all that bad but there is very little convection from puerto rico all the way through africa and what convection there is west of there is due to upper lows or cold fronts in the gom.

http://tropic.ssec.wisc.edu/real-time/s ... plitE&time

[ConvergenceZone]

if we are lucky maybe dry air will make this a slow season. Joe Bastardi has made alot of negative tweets lately. this is today's.

Joe Bastardi ‏@BigJoeBastardi 32m

Meanwhile Global ace has tanked as dry air rules the tropics. Globally about 60% normal,opposite IPCC trapping theory pic.twitter.com/td43pvivsb

Hmm, that's interesting. Well, who knows, we might get lucky and have a year that has too much shear and dry air for storms to get going, but of course it's way way to early to say for sure...

My ultimate season would be if we had lots of cat 4, cat 5 hurricanes that came close to landfall(just to raise excitement and awareness, but then went out to sea). Those are always fun to watch spin up and track

[cycloneye]

We have to see how the steering pattern evolves in the next 3-5 weeks as we enter the peak of the season. GFS is hinting on less ridging in Western Atlantic. If this turns out to be the pattern,then the Caribbean and Eastern CONUS may be without CV systems as they would recurve. But is very early to signal the all clear yet.

(See the Global Model Runs Discussion thread) for details by the models about the ridge.

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.

[cycloneye]

The new ECMWF MJO forecast calls for the wet phase to enter octan 2 which will favor developments in East and Central Atlantic by early August.

[TropicalAnalystwx13]

It's unreasonable to look at one layer of the atmosphere and assume it has a huge correlation with the tropics. Moist 400mb relative humidity values actually have a slightly /negative/ correlation with Atlantic activity. The dry mid- to upper-levels coupled with a moist surface environment is exactly what creates vertical instability, which is crucial to the intensity of tropical cyclones.

August-October 2005 (20 tropical cyclones):



Guess those dry anomalies wrecked the season, huh?

That being said, some seasons...especially in the far past...have experienced very high amounts of activity with plenty of intense storms during years w/ moist 400mb RH across the basin.

End result: it doesn't matter much.

[ninel conde]

We have to see how the steering pattern evolves in the next 3-5 weeks as we enter the peak of the season. GFS is hinting on less ridging in Western Atlantic. If this turns out to be the pattern,then the Caribbean and Eastern CONUS may be without CV systems as they would recurve. But is very early to signal the all clear yet.

(See the Global Model Runs Discussion thread) for details by the models about the ridge.

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.

JB is saying summer is over after this last hot spell which would mean lots of cold fronts sweeping off the coast, the opposite of the pattern he expected in his hurricane forecast. Wxrisk has said to expect strong cold fronts in aug/sept that wont be stalling along the coast. this is not an official forecast but it seems likely to be JB is going to bust bad on his forecast of numerous landfalls this season.

[ninel conde]

It's unreasonable to look at one layer of the atmosphere and assume it has a huge correlation with the tropics. Moist 400mb relative humidity values actually have a slightly /negative/ correlation with Atlantic activity. The dry mid- to upper-levels coupled with a moist surface environment is exactly what creates vertical instability, which is crucial to the intensity of tropical cyclones.

August-October 2005 (20 tropical cyclones):

http://i.imgur.com/YRI17hd.png

Guess those dry anomalies wrecked the season, huh?

That being said, some seasons...especially in the far past...have experienced very high amounts of activity with plenty of intense storms during years w/ moist 400mb RH across the basin.

End result: it doesn't matter much.

thanks for the info.

[weatherwindow]

It's unreasonable to look at one layer of the atmosphere and assume it has a huge correlation with the tropics. Moist 400mb relative humidity values actually have a slightly /negative/ correlation with Atlantic activity. The dry mid- to upper-levels coupled with a moist surface environment is exactly what creates vertical instability, which is crucial to the intensity of tropical cyclones.

August-October 2005 (20 tropical cyclones

Guess those dry anomalies wrecked the season, huh?

That being said, some seasons...especially in the far past...have experienced very high amounts of activity with plenty of intense storms during years w/ moist 400mb RH across the basin.

End result: it doesn't matter much.

Good catch, wx13...have to keep Big Joe honest ...Just an observation, every season it would seem that "we"(including Joe) tend to seize on one or another variable in the very complex thermodynamic regime of trop cyclogenesis. The "variable de jour" is then focussed on to the potential exclusion of the big picture, genesis speaking. Broadly drawn, the season is then hung on the performance of the variable in question. Last year it was vertical instability(or lack of it). It is rarely that simple ...Greetings from Key West, Rich

[beoumont]

I'm kind of curious what time this year we can expect the season to pick up big-time? I know the prediction center is expecting big numbers, so I'm wondering how early in the season it needs to pick up in order for those large numbers to still verify?? I know early to mid July is probably way too early still.... This is more of a question of curiosity is all....

As far as how many major hurricanes are going to form in a season, what happens before mid August (active or in-active) in most cases means absolutely nothing. A prime example is 1961, when there was only one named storm before September 2nd. The year ended up with 3 category 3s, 2 category 4s, and 2 category 5s.

............................................... 1961


Anyone that might use early 2005 as a frame of reference for what to expect in a season is using a once in a lifetime, every factor coincidently in maximum mode, occurrence. It is not likely that anyone who can recall 2005 will still be alive when such a hyper-active season reoccurs.

[NDG]

Here is the July ECMWF MSLP forecast for ASO and it has normal pressures in most of the North Atlantic except in the Western Atlantic and in part of GOM.

http://oi42.tinypic.com/1zee4p4.jpg

Your image is for surface temps not for MSLP, which below is correct image.
BTW, I think the ECMWF is out of its mind, lol.

http://www.ecmwf.int/products/forecasts ... !chart.gif

[cycloneye]

Thank you NDG for the correction of graphics.

[WeatherEmperor]

Luis, how often does that ecmwf map update? If the forecast is true, that could have big time implications. Folks, these are higher than normal forecasted sea level pressures. Tropical cyclones need lower pressures at the surface level in order to form. Only time will tell whether the forecast is true or not

Sent from my HTC EVO 4G LTE

[Hurricane Alexis]

Can temperatures and rainfall patterns in June and July be used to predict activity later on in the season?

[cycloneye]

Luis, how often does that ecmwf map update? If the forecast is true, that could have big time implications. Folks, these are higher than normal forecasted sea level pressures. Tropical cyclones need lower pressures at the surface level in order to form. Only time will tell whether the forecast is true or not

Sent from my HTC EVO 4G LTE

It updates every 15th.

http://www.ecmwf.int/products/forecasts ... 0summary!/

['CaneFreak]

This is the same model that has a history of overestimating the Nino 3.4 SSTAs by a good amount so I wouldn't get too excited about this 3 month forecast...

Luis, how often does that ecmwf map update? If the forecast is true, that could have big time implications. Folks, these are higher than normal forecasted sea level pressures. Tropical cyclones need lower pressures at the surface level in order to form. Only time will tell whether the forecast is true or not

Sent from my HTC EVO 4G LTE

['CaneFreak]

Yes. I have seen links drawn between June and July African Sahel rainfall and activity that occurs later in the season.

Can temperatures and rainfall patterns in June and July be used to predict activity later on in the season?

[WeatherEmperor]

This is the same model that has a history of overestimating the Nino 3.4 SSTAs by a good amount so I wouldn't get too excited about this 3 month forecast...

Luis, how often does that ecmwf map update? If the forecast is true, that could have big time implications. Folks, these are higher than normal forecasted sea level pressures. Tropical cyclones need lower pressures at the surface level in order to form. Only time will tell whether the forecast is true or not

Sent from my HTC EVO 4G LTE

How accurate has this model been at forecasting the mslp pressures? If its been bad historically then I guess we shouldnt take it too seriously

Sent from my HTC EVO 4G LTE

['CaneFreak]

Pretty poor model overall at this range to be honest. I mean it probably has a 50 % accuracy rating. BTW...mslp pressures and sstas basically go hand in hand. These aren't too totally independent entities because the atmosphere and ocean are basically a coupled system (i.e. they depend upon one another).

How accurate has this model been at forecasting the mslp pressures? If its been bad historically then I guess we shouldnt take it too seriously

Sent from my HTC EVO 4G LTE

[SFLcane]

Here is the July ECMWF MSLP forecast for ASO and it has normal pressures in most of the North Atlantic except in the Western Atlantic and in part of GOM.

http://oi42.tinypic.com/1zee4p4.jpg

Your image is for surface temps not for MSLP, which below is correct image.
BTW, I think the ECMWF is out of its mind, lol.

http://www.ecmwf.int/products/forecasts ... !chart.gif

Theres no hurricane season if the european model is correct.