Jump to content
  • Member Statistics

    17,606
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

9/30-10/5 Joaquin-Trough Interaction-MODELS


Rjay

Recommended Posts

  • Replies 1.1k
  • Created
  • Last Reply

Similar model war last winter when Euro was on its own burying NYC in 3 feet of snow even after all the other models trended to a less snowy solution. This time it's the opposite as the euro is alone against a major impactful event. Will be interesting to see how this plays out.

Link to comment
Share on other sites

Similar model war last winter when Euro was on its own burying NYC in 3 feet of snow even after all the other models trended to a less snowy solution. This time it's the opposite as the euro is alone against a major impactful event. Will be interesting to see how this plays out.

Honestly, the way I see it, this is either a Mid NJ hit or OTS. IsentropicLift pointed out correctly that had the ULL not weakened, this would have gone right back towards the coast. A complication now will also be what the remnants of Ida do. Should they reorganize, this presents a whole other set of complications and complexities for forecasting as well.
Link to comment
Share on other sites

I've considered all available guidance and barring a major shift in the 500mb pattern I feel that the final solution ends up splitting the goal posts, not all that dissimilar from the current NHC track. The GFS as well as the rest of the guidance completely ignores the vorticy associated with the remnants of Ida without any sort of Fujiwara effect. If you compare the 500mb vorticy maps they are almost identical, except for that slight shift Eastward due to the Fujiwara that occurs on the Euro and allows it to get just far enough East to escape capture.


 


I'll take the middle of the road scenario which some of the tropical models have shown which is a slight NE jog on day 3 before the ULL digs in and ultimately captures the system. At that point, the mid-level steering pattern would be aligned in such a position that it would just be a matter of where as opposed to if Joaquin will landfall.


 


You can see how the GFS captures the system here at 72 hours and it's game, set, match.


 


  gfs_z500_vort_eus_13.png


 


I will go with a later capture due to the slight initial jog northeast and as a result the system would landfall further North than the current consensus. Gun to my head, somewhere between OBX and VA Beach. 


 


What about impacts for our region?


 


Besides the PRE there should be a good amount of tropical moisture associated with Joaquin not only at the time of landfall but as the ULL ultimately comes North slowly. There should be a fair amount of subsidence around to the North over New England thanks to the impressive high pressure system over Quebec. You're going to flatten out and compress the isobars so I am expecting winds to be quite gusty. In addition, the system should begin interacting with the trough and the combination of that along with cooler SST should begin extra-tropical transition around 35N. We may see a large expansion of the wind field thanks to the natural unraveling that these systems tend to incur, which will only compress the isobars even more further North. I made a post earlier about this wind threat in a different sub-forum. I could see a setup similar to Sandy where the winds at landfall are relatively mundane as compared to a few hundred miles North of the center. Now that doesn't mean I am expecting hurricane force winds up here, but I certainly think a pro-longed period of gales is possible. The affects of that will be most felt at the beaches where the Easterly fetch will persist for more than 72 hours. 


 


Finally, as the remnants move Northward slowly late in the weekend, we should be in a prime position for whatever tropical moisture is leftover, which will be aided not only by the ULL but also the easterly feed off the ocean. 


 


This is obviously a very difficult forecast as you would almost have to start issuing the first preparations tonight, and you have one of the best models in the world taking the system over 500 miles offshore. I don't envy the mets at the NHC or the local NWS offices. Pretty much everything is on the table from a direct hurricane impact to torrential flooding rains to more or less nothing.


Link to comment
Share on other sites

Excellent discussion.   I'm more with the euro on the OTS scenario.   I think the further S movement is correct and that causes it to be too far south and thus it misses the trough.   Time will tell of course but there's almost a due south component on visible.  Another 48 hours of this moving SSW at 6mph and it's 300 miles further south.

-

edit: most of the EPS members are taking this out to sea.  A few recurve back to the mid Altantic.

Link to comment
Share on other sites

Models really struggle with different solutions when hurricanes slow down or make SW dips.

They should converge on a similar solution by Friday once this starts to increase forward motion

again.

Better hope so. This is giving the NWS offices fits.

From Greenville-Spartanburg NWS

"...IT IS FROM THAT POINT ONWARD...00Z SATURDAY...THAT THE WHEELS MAY

FLY OFF IN DIFFERENT DIRECTIONS. THE OPERATIONAL GUIDANCE DIVERGES

SIGNIFICANTLY AND RAPIDLY...AND THE ENSEMBLE SPREAD WIDENS QUICKLY.

THE RECENT MODEL RUNS SHOW EVEN MORE OF A DIFFERENCE IN OUTCOME BY

SATURDAY NIGHT WITH THE TRACK OF JOAQUIN. AS A RESULT...CONFIDENCE

PLUMMETS TOWARD AN ALL TIME LOW...BUT KEEP IN MIND WE ARE DEALING

WITH AN EVENT THAT IS MORE THAN 72H OUT. THERE MIGHT BE A TENDENCY

TO PAY TOO MUCH ATTENTION TO THE OPERATIONAL GFS WITH ITS TRACK OF

THE TROPICAL CYCLONE INLAND...EVENTUALLY LOOPING OVER THE CAROLINA

PIEDMONT OVER THE WEEKEND. IT WOULD BE WISE TO DOWNPLAY THIS IN

FAVOR OF THE OFFICIAL NHC TRACK FOR THE TIME BEING...."

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Guest
This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...