ATL: MATTHEW - Post-Tropical - Discussion

[bg1]

The slightly south of west (still moving west) motion has been predicted for days. I don't see any increasing risk to Florida due to the current wind shear. Once the shear lets off over the next day or two it should blow up to a strong hurricane.

What if the shear doesn't let up? Would it make it farther west before turning?

[OuterBanker]

On vacation in North Myrtle Beach waiting for the outer Banks to be given the all clear from the models.

As usual the wife will have no part of it.

I just don't want to have to prepare shortly after returning (this Saturday).

Just want to enjoy a vacation from storms for the rest of the year.

Yes, I realize that maybe I shouldn't have moved to the outer Banks I wanted to avoid tropical systems.

[wxman57]

On vacation in North Myrtle Beach waiting for the outer Banks to be given the all clear from the models.

As usual the wife will have no part of it.

I just don't want to have to prepare shortly after returning (this Saturday).

Just want to enjoy a vacation from storms for the rest of the year.

Yes, I realize that maybe I shouldn't have moved to the outer Banks I wanted to avoid tropical systems.

You likely won't get any "all-clear" until next week, perhaps by Tuesday. Any impact there won't come until late next week, so you have plenty of time.

[tarheelprogrammer]

 https://twitter.com/philklotzbach/status/781512101709819905

[LarryWx]

Here are many analogs of Matthew. These are most of, if not all, TC's that on record existed at 15N or further south while at least at some points between 50W and 60W at some time 9/25-10/31. What did they do as regards the CONUS? (R = recurve; D = dissipate; S = moved inland south of the CONUS; H = hit on CONUS; ** = closest analogs based on progged track)


1) #8 of 1889: R http://weather.unisys.com/hurricane/atl ... /track.gif

2) #7 of 1892: S http://weather.unisys.com/hurricane/atl ... /track.gif

3) #6 of 1894: R http://weather.unisys.com/hurricane/atl ... /track.gif

4) #5 of 1895: R (just missed SE FL) http://weather.unisys.com/hurricane/atl ... /track.gif

5) #6 of 1896: R http://weather.unisys.com/hurricane/atl ... /track.gif

6) #9 of 1898: R ((just missed SE FL) http://weather.unisys.com/hurricane/atl ... /track.gif

7)#11 of 1901: R http://weather.unisys.com/hurricane/atl ... /track.gif

8) #13 of 1916: R http://weather.unisys.com/hurricane/atl ... /track.gif

9)#14 of 1932***: R http://weather.unisys.com/hurricane/atl ... /track.gif

10)#9 of 1943: R http://weather.unisys.com/hurricane/atl ... /track.gif

11)#11 of 1944: R http://weather.unisys.com/hurricane/atl ... /track.gif

12) Hazel of 1954***: H on NC http://weather.unisys.com/hurricane/atl ... /track.gif

13) Daisy of 1962: R http://weather.unisys.com/hurricane/atl ... /track.gif

14) Flora of 1963: R http://weather.unisys.com/hurricane/atl ... /track.gif

15)Edith of 1967: R http://weather.unisys.com/hurricane/atl ... /track.gif

16)Gertrude of 1974: D http://weather.unisys.com/hurricane/atl ... /track.gif

17)Sebastian of 1995:D http://weather.unisys.com/hurricane/atl ... /track.gif

18) Jose of 1999: R http://weather.unisys.com/hurricane/atl ... /track.gif

19) Joyce of 2000: D http://weather.unisys.com/hurricane/atl ... /track.gif

20) Iris of 2001: S http://weather.unisys.com/hurricane/atl ... /track.gif

21) Jerry of 2001: D http://weather.unisys.com/hurricane/atl ... /track.gif

22) Tomas of 2010***:R http://weather.unisys.com/hurricane/atl ... /track.gif


Tally: 22 storms, 15 recurves, 4 dissipations, 2 hit south of the CONUS, and only 1 CONUS hit (Hazel). Closest analogs per track progs: 1932, 1954, 2010


So, climo is obviously not on the side of a CONUS hit (only 1 hit out of 22 analog storms or 5% of the analogs) though that, of course, doesn't mean there's no chance for that. Actually, I feel that the chance for a CONUS hit is far greater than 5%. I think it is currently more like 33% based on modeled close calls to especially the NC to NE corridor and because one of the three closest analogs (1932, 1954, 2010) did hit the CONUS. Many of the climo tracks can immediately be disqualified due to them being so different right from the start.

Good stuff Larry! Though, I'd be a bit more curious what the results would be based on a storm "existing" (rather than point of genesis) at or south of 15N and between 70-75W, given this to be a likely account of where Matthew will be in the near future. I have to assume the percentage of Conus landfall would be over 15%. If so, then I suppose the assumption would then already paint Matthew as an outlier storm given that most others seemingly recurved whereas Matthew is likely to at least reach 70 west at a pretty low latitude.

Thanks. Great question. Yes, Matthew appears to be an outlier vs most analog tracks. That's why I have the CONUS hit chance at 33% rather than 8%. Looking at these analogs (now up to 25 due to my finding three I inadvertently left off the list), the ones that were at or south of 15N between 70-75W (where Matthew progs take him) are as follows:

1) #4 of 1876 (added): S http://weather.unisys.com/hurricane/atl ... /track.gif
2) #7 of 1892: S http://weather.unisys.com/hurricane/atl ... /track.gif
3) #5 of 1895: R (just missed SE FL) http://weather.unisys.com/hurricane/atl ... /track.gif
4) #14 of 1932***: R http://weather.unisys.com/hurricane/atl ... /track.gif
5) Hazel of 1954***: H on NC http://weather.unisys.com/hurricane/atl ... /track.gif
6) Tomas of 2010***: R http://weather.unisys.com/hurricane/atl ... /track.gif

So, one of these 6 hit the CONUS and one other just missed SE FL. So, 2 of the 6 (33%) were at least a threat to the CONUS. Also, note that the other one that barely missed SE FL, #9 of 1898, traveled only barely north of 15N between 70 and 75W:
http://weather.unisys.com/hurricane/atl ... /track.gif

In addition, newly added #6 of 1879, which did hit the CONUS, also only barely traveled north of 15N between 70 and 75W:
http://weather.unisys.com/hurricane/atl ... /track.gif

So, if #9 of 1898 and #6 of 1879 were included, that would make 4 of the best 8 analogs (50%) that were at least a threat to the CONUS.

[La Sirena]

So very quiet today!

[SouthDadeFish]

New convective burst firing just NE of the center:



Cloud tops are below -80C:

[cajungal]

So very quiet today!

Board always goes quiet when models trend east and a hit to the United States becomes less.

[Alyono]

The slightly south of west (still moving west) motion has been predicted for days. I don't see any increasing risk to Florida due to the current wind shear. Once the shear lets off over the next day or two it should blow up to a strong hurricane.

What if the shear doesn't let up? Would it make it farther west before turning?

Shallow BAM says a much sharper recurve if it remains an exposed center

[TropicalAnalystwx13]

Unlike last night, when Matthew's circulation was on the edge of the convection due solely to its quick forward motion, there is definitely some shear today. Outflow is no longer expanding west, and instead you can see flow out of the southwest. This shear should persist until tomorrow afternoon, when it should lower once again. Rapid intensification continues to look likely as Matthew makes its curve northwest.

[chaser1]

Here are many analogs of Matthew. These are most of, if not all, TC's that on record existed at 15N or further south while at least at some points between 50W and 60W at some time 9/25-10/31. What did they do as regards the CONUS? (R = recurve; D = dissipate; S = moved inland south of the CONUS; H = hit on CONUS; ** = closest analogs based on progged track)

1898: R ((just missed SE FL) http://weather.unisys.com/hurricane/atl ... /track.gif

Good stuff Larry! Though, I'd be a bit more curious what the results would be based on a storm "existing" (rather than point of genesis) at or south of 15N and between 70-75W, given this to be a likely account of where Matthew will be in the near future. I have to assume the percentage of Conus landfall would be over 15%. If so, then I suppose the assumption would then already paint Matthew as an outlier storm given that most others seemingly recurved whereas Matthew is likely to at least reach 70 west at a pretty low latitude.

Thanks. Great question. Yes, Matthew appears to be an outlier vs most analog tracks. That's why I have the CONUS hit chance at 33% rather than 5%. Looking at these analogs, the ones that were at or south of 15N between 70-75W were as follows:

1) #7 of 1892: S http://weather.unisys.com/hurricane/atl ... /track.gif
2) #5 of 1895: R (just missed SE FL) http://weather.unisys.com/hurricane/atl ... /track.gif
3) #14 of 1932***: R http://weather.unisys.com/hurricane/atl ... /track.gif
4) Hazel of 1954***: H on NC http://weather.unisys.com/hurricane/atl ... /track.gif
5) Tomas of 2010***: R http://weather.unisys.com/hurricane/atl ... /track.gif

So, one of these 5 hit the CONUS and one other just missed SE FL. So, 2 of the 5 (40%) were at least a threat to the CONUS. Also, note that the other one that barely missed SE FL, #9 of 1898, traveled only barely north of 15N between 70 and 75W:

http://weather.unisys.com/hurricane/atl ... /track.gif

So, if #9 of 1898 were included, that would make 3 of 6 (50%) that were at least a threat to the CONUS.

Wow!? Throw in 1898, and i'd say these are some pretty good analogues systems. 1895 and 1954 seem to best fit present scenario as depicted by present models and/or forecast. Unfortunately, these analogies exclude what i'm guessing to be a number of storms that entered the Gulf and made landfall anywhere from Texas, east to Florida. Those storms would have likely represented those years where perhaps a storm "formed" near or south of 15N and from 70-75W with a good number of them likely tracking northwest. Genesis aside, these storms might equally serve as a reasonable analogous comparison as well.

[ThetaE]

Unlike last night, when Matthew's circulation was on the edge of the convection due solely to its quick forward motion, there is definitely some shear today. Outflow is no longer expanding west, and instead you can see flow out of the southwest. This shear should persist until tomorrow afternoon, when it should lower once again. Rapid intensification continues to look likely as Matthew makes its curve northwest.

This is the most important point, IMO. Once this shear does actually die down, Matthew should be greeted with favorable conditions and will strengthen rapidly. I don't see this not making at least cat 3; even sheared like this, it's already almost a hurricane.

[SouthDadeFish]

Unlike last night, when Matthew's circulation was on the edge of the convection due solely to its quick forward motion, there is definitely some shear today. Outflow is no longer expanding west, and instead you can see flow out of the southwest. This shear should persist until tomorrow afternoon, when it should lower once again. Rapid intensification continues to look likely as Matthew makes its curve northwest.

This doesn't make too much sense to me. Why would the center be on the edge of the convection just because of the TC's fast forward motion and not wind shear? If there was no wind shear yesterday, the center should have been embedded within the convection as the TC moved along at a brisk pace. Do you mean there was mid-level shear yesterday as opposed to more of a deep-layer shear profile today?

[TropicalAnalystwx13]

Unlike last night, when Matthew's circulation was on the edge of the convection due solely to its quick forward motion, there is definitely some shear today. Outflow is no longer expanding west, and instead you can see flow out of the southwest. This shear should persist until tomorrow afternoon, when it should lower once again. Rapid intensification continues to look likely as Matthew makes its curve northwest.

This doesn't make too much sense to me. Why would the center be on the edge of the convection just because of the TC's fast forward motion and not wind shear? If there was no wind shear yesterday, the center should have been embedded within the convection as the TC moved along at a brisk pace. Do you mean there was mid-level shear yesterday as opposed to more of a deep-layer shear profile today?

I should reword. There was shear last night, but it speed shear--not shear induced by any upper-level trough like we're seeing today.

[La Sirena]

So very quiet today!

Board always goes quiet when models trend east and a hit to the United States becomes less.

Yeah, I can see that! At least it's a tiny break from the self assured prognostications I know that's half the meteorological fun but this one has kept everyone so off-balance. No offense to anyone please! I'm just watching and enjoying all the info as long as I'm laid up with a shoulder injury lol.

[psyclone]

I must also raise a toast to Hammy for a great call last night on the shear. the system looked great but was poorly organized with the center on the southwest side of the convective ball. There's been an awful lot of flaming/unwarranted blowback on lately on posters who aren't as bullish on a storm or simply state that the risk for a given area is low or decreasing. that is unfortunate and benefits no one. On that same note we've got a two-fer for Florida folks...the risk appears low and has been decreasing. Naturally that does not mean there is no risk. that's why we watch forecasts evolve. but there's nothing wrong with stating the current scene and trends. happy watching.

[mrbagyo]

looks pretty darn good to me even if it's a little bit sheared.

[GCANE]

Steering at the moment is WSW.
Looks like its on course.

[Aric Dunn]

Its about 3 hours fast to the 18z position from the 5am advisory...

[chaser1]

The slightly south of west (still moving west) motion has been predicted for days. I don't see any increasing risk to Florida due to the current wind shear. Once the shear lets off over the next day or two it should blow up to a strong hurricane.

What if the shear doesn't let up? Would it make it farther west before turning?

Shallow BAM says a much sharper recurve if it remains an exposed center

Sure enough??! What I find odd though is that the shallow BAM reflects that shallow layer closest to the surface and yet when looking at the GFS analysis and near term forecast, I'm just not seeing evidence of easterly trades or any originating flow throughout the Central Caribbean being southerly which would seem prerequisite for the Shallow BAM to take into account? I know that the BAMS measures an average flow from approx. 700mb and lower, but does that extend all the way to the surface? As an aside, I looked at the 850mb flow and oddly there's no reflection of a southerly component to winds at this height either. Just trying to see... what it is that I don't see lol.