Seasonal Indicators (Beyond Day 16): Instability / SST's / MSLP / Steering / Sal

[NDG]

I still think we will see a change in the pattern towards the middle and end of July, both the CFSv2 and Euro see it. The CFSv2 shows the eastern Pacific drying up towards the end of the month, so it makes sense that the Atlantic could see some activity by then.
Both are showing average to below average MSLPs taking over the Atlantic's MDR over the next few days. The Euro also shows ridging taking over the eastern US and SE Canada.

[Alyono]

some go on science. Others like to just use sound bites and try and pass them off as science.

Of course the Gulf will produce more storms this year. Thunderstorm complexes can easily develop into tropical storms or hurricanes. Also, a wave may not develop until it reaches the Gulf, just as we saw with Danielle this year. The Gulf has produced 2 storms, and some are STILL saying the Gulf will be dead? This despite every single analog showing major Gulf impacts, especially in August? That's soundbite meteorology, not science

Yes, 2 slop storms which often happens in dead seasons. Lets wait and see when a well developed hurricane with a well defined center wrapped all the way around with convection can survive north of 25.

Where is the science to back up your argument? You again just spewed a sound bite. Meaningless. Lets hear some real science

[Dean4Storms]

I still think we will see a change in the pattern towards the middle and end of July, both the CFSv2 and Euro see it. The CFSv2 shows the eastern Pacific drying up towards the end of the month, so it makes sense that the Atlantic could see some activity by then.
Both are showing average to below average MSLPs taking over the Atlantic's MDR over the next few days. The Euro also shows ridging taking over the eastern US and SE Canada.

Yea I agree.... Already seeing ECM backing off the Ridging over the MDR by the 20th at 500mb which this ridge is deep layer which slow the trades and lessen the SAL. I think by mid Aug. the MDR is active, see no reason why it shouldn't at this point.

[tarheelprogrammer]

Biggest thing at least IMHO for this season is shear in the Caribbean. Storms are spinning up in the Pacific at a record pace and that doesn't seem to be slowing down at all in the models as the GFS shows storms spinning up all the way to hour 384. That in turn is creating shear in the Caribbean. So, a similar set up to last season where waves were surviving the MDR only to be shredded in the Caribbean. If the Pacific keeps it up then shear will also stay up in that area and thus make it an inhospitable place for TCs to develop. Am I missing something?

[Hurricaneman]

Biggest thing at least IMHO for this season is shear in the Caribbean. Storms are spinning up in the Pacific at a record pace and that doesn't seem to be slowing down at all in the models as the GFS shows storms spinning up all the way to hour 384. That in turn is creating shear in the Caribbean. So, a similar set up to last season where waves were surviving the MDR only to be shredded in the Caribbean. If the Pacific keeps it up then shear will also stay up in that area and thus make it an inhospitable place for TCs to develop. Am I missing something?

What you're seeing is the GFS depiction which has also the MJO backing up from phase1 to phase8 which more likely than not will not happen due to how the MJO works when the BOM and Euro have been saying the MJO will be more favorable for the atlantic and do a normal propagation from phase 1 to phase4 in a months time so I do believe based on that the GFS could be wrong due to that and seems slightly. Also based on past history go with the Euro and based on that the first of August will most likely have a pickup if not late month while the EPAC goes into a short lull

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or STORM2K. For official information, please refer to products from the National Hurricane Center and National Weather Service

[tolakram]

Who has made a definitive connection of EPAC activity creating shear? It's still below normal in all regions.



source: http://rammb.cira.colostate.edu/project ... _00-24.asp

Saved image of current shear:

[Ntxw]

Alright folks, remember this is not a chat room. It is OK to state your opinion and provide ample data and thoughts. Lets not direct at other posters even if you disagree. Mark (Tolakram) has already made note in a post. Also it doesn't do good to post the same thing over againt about your point. Most readers do not enjoy the bickering and can decipher on their judgement.

Lets keep the dicussions progressive guys. If there is a problematic post please don't respond to it, rather report it to staff.

[xcool22]

why is EPAC so active ?



The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or STORM2K. For official information, please refer to products from the National Hurricane Center and National Weather Service.

[Ntxw]

why is EPAC so active ?



The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or STORM2K. For official information, please refer to products from the National Hurricane Center and National Weather Service.

The EPAC is one of the more active basins on earth. Its not going to stay quiet forever and bursts of activity even in quiet years is not unusual. This is why their season tends to be longer. A month's of activity does not always foresee the rest of the season. July into August runs into their cruiser months when storms form and travel great lengths westward. Their peak, in general, occurs sooner than the ATL

[NDG]

Biggest thing at least IMHO for this season is shear in the Caribbean. Storms are spinning up in the Pacific at a record pace and that doesn't seem to be slowing down at all in the models as the GFS shows storms spinning up all the way to hour 384. That in turn is creating shear in the Caribbean. So, a similar set up to last season where waves were surviving the MDR only to be shredded in the Caribbean. If the Pacific keeps it up then shear will also stay up in that area and thus make it an inhospitable place for TCs to develop. Am I missing something?

What shear?



The only thing negatively impacting the Caribbean that I see right now is strong h85 diverging winds due to the strong subtropical Atlantic ridge and all of the air rising over the EPAC side, but as soon as the EPAC action slows down as forecasted by the CFSv2, h85 winds over the Caribbean will slow down.

[tarheelprogrammer]

I thought I seen some people on here or somewhere else saying that activity in the Pacific leads to shear in the Caribbean. I am not MET and not here to argue I am just trying to get information and you guys know more than I about this stuff as I am fairly new to weather related stuff. I did talk with Philip Klotzbach on twitter a week or so ago and he said he sees more high pressure and shear than originally thought or at least more than some other people think. If I can find the tweet I will post it here later.

Tweet from Philip Klotzbach to my account a little while ago.

I asked whether an active Pacific ocean meant shear for the Caribbean. His response below:
Depends on where TCs are in the Pacific. In a broad sense active NE Pacific periods tend to be inactive for the Atlantic.

If any other pro METS want to chime in that would be great.

[tolakram]

Careful with the echo chamber effect.

The EPAC almost had its latest start ever and is seeing a burst of activity, but this burst does not in any way indicate the entire season will be active. Remember you can do your own research. Google 'YYYY eastern pacific hurricane season' and replace YYYY with the year of your choosing. Compare these years to the Atlantic and decide if what we are seeing in the EPAC is an indicator of anything.

2005, for example, was considered an average season with 15/7/2 and 2004 was one of the slowest on record with just 12/6/3. EPAC is a beast at cranking out storms, even in slow years IMO.

[Ntxw]

I thought I seen some people on here or somewhere else saying that activity in the Pacific leads to shear in the Caribbean. I am not MET and not here to argue I am just trying to get information and you guys know more than I about this stuff as I am fairly new to weather related stuff. I did talk with Philip Klotzbach on twitter a week or so ago and he said he sees more high pressure and shear than originally thought or at least more than some other people think. If I can find the tweet I will post it here later.

Tweet from Philip Klotzbach to my account a little while ago.

I asked whether an active Pacific ocean meant shear for the Caribbean. His response below:
Depends on where TCs are in the Pacific. In a broad sense active NE Pacific periods tend to be inactive for the Atlantic.

If any other pro METS want to chime in that would be great.

Epac can lead to more shear though the relationship is not as simple as if there are systems there is more shear. You need lower pressures there in the broader pattern as the canes themselves are small relative to everything else. It is more effective with El Nino because convection in the tropical EPAC is numberous along with/in part of the activity thus stronger gradient with the pressures over in the Carib. Honestly, storms riding up west of the Mexican coast is more of an issue than the storms traveling away west as they are currently.

[tarheelprogrammer]

Is there any chance that the ITCZ never shifts north? Has that ever happened before? Dumb question I know but couldn't find info online even with my programmer tricks probably because IDK what to look for.

[Ntxw]

Is there any chance that the ITCZ never shifts north? Has that ever happened before? Dumb question I know but couldn't find info online even with my programmer tricks probably because IDK what to look for.

It moves north with the seasons along the temperature gradient as the northern hemisphere warms. If it doesnt we would have a global problem.

[tarheelprogrammer]

Is there any chance that the ITCZ never shifts north? Has that ever happened before? Dumb question I know but couldn't find info online even with my programmer tricks probably because IDK what to look for.

It moves north with the seasons along the temperature gradient as the northern hemisphere warms. If it doesnt we would have a global problem.

lol okay let's hope not. Thanks everyone for the feedback and answers to questions.

[tarheelprogrammer]

Anybody know what the top analogs are currently for this season?

[Ntxw]

Tropicaltidbits has great page on analogs based on SST data. Though limited it is a good place to start. One year that has shown up on his datasets is 1959, also mentioned several times by Andrew

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

[tarheelprogrammer]

Tropicaltidbits has great page on analogs based on SST data. Though limited it is a good place to start. One year that has shown up on his datasets is 1959, also mentioned several times by Andrew

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

Yeah 1959 looks like it is the best analog because it is the only one that shows up in both analog sets. Not a good year for South Carolina.

[cycloneye]

Is normal in July.

 https://twitter.com/EricBlake12/status/752265486230884352