2020 Indicators: SST's / SAL / MSLP / Steering / Shear / Instability / Sat Images

[Aric Dunn]

Rossby waves are starting to pull north for the season.
Two main Anticyclone Rossby Wave Breaks (ARWB) currently in the Atlantic.
Result is that shear is dropping quickly.
SAL just needs to settle down.
Latest wave is riding high, looks like it'll be a sweeper.


https://i.imgur.com/1NGmVQE.png

https://i.imgur.com/1xIundL.gif

https://i.imgur.com/LlmlM8F.gif

https://i.imgur.com/BbOBaYW.gif

https://i.imgur.com/uYEd90X.png

https://i.imgur.com/5Ck1r7S.jpg

SAL will/has already started to shift/subside in the lower latitudes thanks in part to a shift if the flow over the SAL producing regions as well as actual precip falling in the lower sahel areas.

Plumes of SAL should stay north moving more wnw for the next couple weeks.. instead of being pushed wsw/W

[jconsor]

 https://twitter.com/AndyHazelton/status/1283024836525260801

[Shell Mound]

https://twitter.com/AndyHazelton/status/1283024836525260801

The ridge looks a bit too meridional and is displaced too far to the northeast for CV-type landfalls on Southeast FL, doesn’t it? Normally the ridge axis is farther SW during such impacts. This time the axis is east of Bermuda on both the JMA and UKMET forecasts. Now this isn’t necessarily an OTS pattern, but it looks more like threatening to the Carolinas, Mid-Atlantic, and/or S New England than to S FL. Even if South FL gets hit from the SW in October, late-season hits tend not to be as strong/dangerous as the Aug/Sept ones, the latter of which tend to form in the MDR and produce most of South FL’s Cat-4+ landfalls. Plus, direct hits from the Atlantic don’t have to weaken over land, unlike late-season hits such as Wilma, which, despite making landfall in SW FL as a Cat-3, produced only TS or low-end Cat-1 conditions in metropolitan SE FL.

[toad strangler]

https://twitter.com/AndyHazelton/status/1283024836525260801

The ridge looks a bit too meridional and is displaced too far to the northeast for CV-type landfalls on Southeast FL, doesn’t it? Normally the ridge axis is farther SW during such impacts. This time the axis is east of Bermuda on both the JMA and UKMET forecasts. Now this isn’t necessarily an OTS pattern, but it looks more like threatening to the Carolinas, Mid-Atlantic, and/or S New England than to S FL. Even if South FL gets hit from the SW in October, late-season hits tend not to be as strong/dangerous as the Aug/Sept ones, the latter of which tend to form in the MDR and produce most of South FL’s Cat-4+ landfalls. Plus, direct hits from the Atlantic don’t have to weaken over land, unlike late-season hits such as Wilma, which, despite making landfall in SW FL as a Cat-3, produced only TS or low-end Cat-1 conditions in metropolitan SE FL.

S FL is a small spec of land, a tiny pc of real estate when it comes to these kinds of discussions. It makes no sense IMO to focus that narrow. There is something called paralysis by analysis

EDIT to say, I work in the roofing industry and let me tell you by many first hand accounts, Wilma punched the southern peninsula right in the teeth and knocked a few out.

[AutoPenalti]

https://twitter.com/AndyHazelton/status/1283024836525260801

The ridge looks a bit too meridional and is displaced too far to the northeast for CV-type landfalls on Southeast FL, doesn’t it? Normally the ridge axis is farther SW during such impacts. This time the axis is east of Bermuda on both the JMA and UKMET forecasts. Now this isn’t necessarily an OTS pattern, but it looks more like threatening to the Carolinas, Mid-Atlantic, and/or S New England than to S FL. Even if South FL gets hit from the SW in October, late-season hits tend not to be as strong/dangerous as the Aug/Sept ones, the latter of which tend to form in the MDR and produce most of South FL’s Cat-4+ landfalls. Plus, direct hits from the Atlantic don’t have to weaken over land, unlike late-season hits such as Wilma, which, despite making landfall in SW FL as a Cat-3, produced only TS or low-end Cat-1 conditions in metropolitan SE FL.

Again, all it takes is intraseasonal forcing, even sudden mesoscale changes (that can't be predicted weeks out), for this to be completely thrown out the window.

[SFLcane]

https://twitter.com/AndyHazelton/status/1283024836525260801

Very favorable look for TCs and landfalls!

[jconsor]

 https://twitter.com/BenNollWeather/status/1283046089415725056

[Shell Mound]

https://twitter.com/AndyHazelton/status/1283024836525260801

The ridge looks a bit too meridional and is displaced too far to the northeast for CV-type landfalls on Southeast FL, doesn’t it? Normally the ridge axis is farther SW during such impacts. This time the axis is east of Bermuda on both the JMA and UKMET forecasts. Now this isn’t necessarily an OTS pattern, but it looks more like threatening to the Carolinas, Mid-Atlantic, and/or S New England than to S FL. Even if South FL gets hit from the SW in October, late-season hits tend not to be as strong/dangerous as the Aug/Sept ones, the latter of which tend to form in the MDR and produce most of South FL’s Cat-4+ landfalls. Plus, direct hits from the Atlantic don’t have to weaken over land, unlike late-season hits such as Wilma, which, despite making landfall in SW FL as a Cat-3, produced only TS or low-end Cat-1 conditions in metropolitan SE FL.

S FL is a small spec of land, a tiny pc of real estate when it comes to these kinds of discussions. It makes no sense IMO to focus that narrow. There is something called paralysis by analysis

EDIT to say, I work in the roofing industry and let me tell you by many first hand accounts, Wilma punched the southern peninsula right in the teeth and knocked a few out.

I was referring to worst-case scenarios such as major hurricane winds directly affecting metropolitan SE FL. Obviously, even a strong TS or low-end Cat-1 is nothing to dismiss. Nevertheless, now is the time to start looking for clues as to the upcoming pattern in ASO. I’ve compared the 500-mb pattern associated with MH hits in mainland SE FL vs. the pattern shown for ASO in the latest JMA, UKMET, ECMWF, and CFSv2 models, along with the NMME. The ridging on these runs, while strong, seems to be more elongated E-W vs. N-S, whereas MH hits on mainland SE FL tended to feature ridging oriented N-S. In the latter case the ridging also was centred somewhat farther southwest. Do a composite for the storms of 1926, 1928, 1933, 1941, 1945, and 1947 and compare with the latest forecasts.

[weathaguyry]

This setup is very unsettling here on Long Island. The strange placement of the Bermuda High to the NE keeps allowing for intervals of straight S to N or SSW to NNE flow along the east coast. If this persists into peak season, I would bet my hat that at least one hurricane will at least threaten the Carolinas northward to New England.

[Shell Mound]

From this thread:

https://twitter.com/dylanfedericowx/status/1283041901361455111?s=21

If we don’t see at least one TC in the MDR before August, a hyperactive season becomes quite unlikely.* Plain old “above average” will happen instead.

*Of course, among hyperactive years there have exceptions such as 2004, but these were, as mentioned, exceptions rather than the norm.

Edit: Latest ECMWF also suggests a lot of subsidence over most of the Atlantic basin during August/September, owing to rising branch over W IO/Africa.

Actually, a strong African Standing Wave is a plus for Atlantic activity because it enhances tropical wave activity. If you look at each of the most recent hyperactive years you'll notice that they all have this in common:
https://psl.noaa.gov/tmp/composites/K5Ip5tVhR9.png

Meanwhile in the less active seasons the ENSO standing wave tends to be the dominant player and the rising cell over Africa is significantly less pronounced:
https://psl.noaa.gov/tmp/composites/_TeXD2ObVd.png

I know this is a repost from the ENSO thread but if you take a look at the VP pattern over the past few months you'll see that it matches up much more with the former.
https://psl.noaa.gov/tmp/composites/O6AwM7WNga.png

I was alluding to the fact that the latest ECMWF shows the sinking branch being centred west of the International Date Line and the rising branch over the western Indian Ocean rather than Africa during ASO. This results in the sinking branch over the Atlantic being larger than is typical of hyperactive seasons. See the following illustration below:

 https://twitter.com/BenNollWeather/status/1283046089415725056

[TheStormExpert]

https://twitter.com/AndyHazelton/status/1283024836525260801

The ridge looks a bit too meridional and is displaced too far to the northeast for CV-type landfalls on Southeast FL, doesn’t it? Normally the ridge axis is farther SW during such impacts. This time the axis is east of Bermuda on both the JMA and UKMET forecasts. Now this isn’t necessarily an OTS pattern, but it looks more like threatening to the Carolinas, Mid-Atlantic, and/or S New England than to S FL. Even if South FL gets hit from the SW in October, late-season hits tend not to be as strong/dangerous as the Aug/Sept ones, the latter of which tend to form in the MDR and produce most of South FL’s Cat-4+ landfalls. Plus, direct hits from the Atlantic don’t have to weaken over land, unlike late-season hits such as Wilma, which, despite making landfall in SW FL as a Cat-3, produced only TS or low-end Cat-1 conditions in metropolitan SE FL.

I agree with you when it comes to steering favoring Carolina/Mid-Atlantic/Northeast U.S. threats as opposed to East Coast of Florida threats which are very rare to begin with. Still can’t rule out a Irene (1999), Charley (2004), or Wilma like track across the Florida peninsula but I disagree that Wilma only produced TS or low-end Cat.1 winds here in S.FL.

[Shell Mound]

https://twitter.com/AndyHazelton/status/1283024836525260801

The ridge looks a bit too meridional and is displaced too far to the northeast for CV-type landfalls on Southeast FL, doesn’t it? Normally the ridge axis is farther SW during such impacts. This time the axis is east of Bermuda on both the JMA and UKMET forecasts. Now this isn’t necessarily an OTS pattern, but it looks more like threatening to the Carolinas, Mid-Atlantic, and/or S New England than to S FL. Even if South FL gets hit from the SW in October, late-season hits tend not to be as strong/dangerous as the Aug/Sept ones, the latter of which tend to form in the MDR and produce most of South FL’s Cat-4+ landfalls. Plus, direct hits from the Atlantic don’t have to weaken over land, unlike late-season hits such as Wilma, which, despite making landfall in SW FL as a Cat-3, produced only TS or low-end Cat-1 conditions in metropolitan SE FL.

I agree with you when it comes to steering favoring Carolina/Mid-Atlantic/Northeast U.S. threats as opposed to East Coast of Florida threats which are very rare to begin with. Still can’t rule out a Irene (1999), Charley (2004), or Wilma like track across the Florida peninsula but I disagree that Wilma only produced TS or low-end Cat.1 winds here in S.FL.

Except for isolated Cat-2 winds near Lake Okeechobee, official data confirm that Wilma only generated TS or low-end Cat-1 sustained winds in metropolitan SE FL. Of course, gusts certainly reached Cat-2 or even low-end Cat-3 intensity.

[typhoonty]

https://twitter.com/AndyHazelton/status/1283024836525260801

The ridge looks a bit too meridional and is displaced too far to the northeast for CV-type landfalls on Southeast FL, doesn’t it? Normally the ridge axis is farther SW during such impacts. This time the axis is east of Bermuda on both the JMA and UKMET forecasts. Now this isn’t necessarily an OTS pattern, but it looks more like threatening to the Carolinas, Mid-Atlantic, and/or S New England than to S FL. Even if South FL gets hit from the SW in October, late-season hits tend not to be as strong/dangerous as the Aug/Sept ones, the latter of which tend to form in the MDR and produce most of South FL’s Cat-4+ landfalls. Plus, direct hits from the Atlantic don’t have to weaken over land, unlike late-season hits such as Wilma, which, despite making landfall in SW FL as a Cat-3, produced only TS or low-end Cat-1 conditions in metropolitan SE FL.

I would suggest to abstain from talking in such absolutes. No one has the ability to prognosticate to the degree of specificity that you are espousing. If anyone did, they be compensated well above the meteorologist paygrade. Also, a strike from the south or southwest does not preclude metro SEFL from taking a direct hit from a major hurricane. The 1906 Florida Keys hurricane comes to mind as an example of this, and Irma came very close to being a direct hit despite a weakness over Florida. So the lack of a ridge does not save SEFL as a matter of course. I'd hate to lull people into a false sense of security.

It also seems like your underselling the intensity of Wilma in metro south Florida by about a category. I would categorize Katrina as a strong ts or weak hurricane impact for S FL. Wilma produced sustained winds of 85-90 mph from Virginia key north. And winds of over 100 mph sustained in palm beach county. Not to mention gusts 100-120 mph from Opa.Locka and Fowley Rocks north. I'm sure if you were in central or south dade your assessment would be correct, but not for the balance of S FL as was asserted.

[tolakram]

The ridge looks a bit too meridional and is displaced too far to the northeast for CV-type landfalls on Southeast FL, doesn’t it? Normally the ridge axis is farther SW during such impacts. This time the axis is east of Bermuda on both the JMA and UKMET forecasts. Now this isn’t necessarily an OTS pattern, but it looks more like threatening to the Carolinas, Mid-Atlantic, and/or S New England than to S FL. Even if South FL gets hit from the SW in October, late-season hits tend not to be as strong/dangerous as the Aug/Sept ones, the latter of which tend to form in the MDR and produce most of South FL’s Cat-4+ landfalls. Plus, direct hits from the Atlantic don’t have to weaken over land, unlike late-season hits such as Wilma, which, despite making landfall in SW FL as a Cat-3, produced only TS or low-end Cat-1 conditions in metropolitan SE FL.

I agree with you when it comes to steering favoring Carolina/Mid-Atlantic/Northeast U.S. threats as opposed to East Coast of Florida threats which are very rare to begin with. Still can’t rule out a Irene (1999), Charley (2004), or Wilma like track across the Florida peninsula but I disagree that Wilma only produced TS or low-end Cat.1 winds here in S.FL.

Except for isolated Cat-2 winds near Lake Okeechobee, official data confirm that Wilma only generated TS or low-end Cat-1 sustained winds in metropolitan SE FL. Of course, gusts certainly reached Cat-2 or even low-end Cat-3 intensity.

This is a great example of the perils of measuring hurricanes with wind speeds. Wilma was HUGE and the swath of hurricane force winds covered a gigantic area, where in a 'normal' hurricane the wind field is in fact very tiny. The amount of damage was extreme, with some areas inaccessible for days.

I have to say, as a poster, not as an admin, that I am weary of the predictions of landfall locations or even the setup for the next month or so. Skill is so incredibly low in all of these predictions that I don't think it's worth putting much thought into. Weather systems are not fixed, so any 'ridge' is going to grow and shrink and move all summer long (correct?).

Out of curiosity I'd like to see some analysis of the 2008 upper air patterns (Ike goes south) and other seasons that features ridges so strong that storms were steered almost due west rather than recurving.

[869MB]

I agree with you when it comes to steering favoring Carolina/Mid-Atlantic/Northeast U.S. threats as opposed to East Coast of Florida threats which are very rare to begin with. Still can’t rule out a Irene (1999), Charley (2004), or Wilma like track across the Florida peninsula but I disagree that Wilma only produced TS or low-end Cat.1 winds here in S.FL.

Except for isolated Cat-2 winds near Lake Okeechobee, official data confirm that Wilma only generated TS or low-end Cat-1 sustained winds in metropolitan SE FL. Of course, gusts certainly reached Cat-2 or even low-end Cat-3 intensity.

This is a great example of the perils of measuring hurricanes with wind speeds. Wilma was HUGE and the swath of hurricane force winds covered a gigantic area, where in a 'normal' hurricane the wind field is in fact very tiny. The amount of damage was extreme, with some areas inaccessible for days.

I have to say, as a poster, not as an admin, that I am weary of the predictions of landfall locations or even the setup for the next month or so. Skill is so incredibly low in all of these predictions that I don't think it's worth putting much thought into. Weather systems are not fixed, so any 'ridge' is going to grow and shrink and move all summer long (correct?).

Out of curiosity I'd like to see some analysis of the 2008 upper air patterns (Ike goes south) and other seasons that features ridges so strong that storms were steered almost due west rather than recurving.

Ironically, just yesterday, I was wondering the exact same thing myself regarding the 2008 upper air pattern.

[toad strangler]

https://twitter.com/AndyHazelton/status/1283024836525260801

The ridge looks a bit too meridional and is displaced too far to the northeast for CV-type landfalls on Southeast FL, doesn’t it? Normally the ridge axis is farther SW during such impacts. This time the axis is east of Bermuda on both the JMA and UKMET forecasts. Now this isn’t necessarily an OTS pattern, but it looks more like threatening to the Carolinas, Mid-Atlantic, and/or S New England than to S FL. Even if South FL gets hit from the SW in October, late-season hits tend not to be as strong/dangerous as the Aug/Sept ones, the latter of which tend to form in the MDR and produce most of South FL’s Cat-4+ landfalls. Plus, direct hits from the Atlantic don’t have to weaken over land, unlike late-season hits such as Wilma, which, despite making landfall in SW FL as a Cat-3, produced only TS or low-end Cat-1 conditions in metropolitan SE FL.

I agree with you when it comes to steering favoring Carolina/Mid-Atlantic/Northeast U.S. threats as opposed to East Coast of Florida threats which are very rare to begin with. Still can’t rule out a Irene (1999), Charley (2004), or Wilma like track across the Florida peninsula but I disagree that Wilma only produced TS or low-end Cat.1 winds here in S.FL.

OK lets not get crazy. Tracks into GA are very rare. Not E Coast of FL

[TheStormExpert]

The ridge looks a bit too meridional and is displaced too far to the northeast for CV-type landfalls on Southeast FL, doesn’t it? Normally the ridge axis is farther SW during such impacts. This time the axis is east of Bermuda on both the JMA and UKMET forecasts. Now this isn’t necessarily an OTS pattern, but it looks more like threatening to the Carolinas, Mid-Atlantic, and/or S New England than to S FL. Even if South FL gets hit from the SW in October, late-season hits tend not to be as strong/dangerous as the Aug/Sept ones, the latter of which tend to form in the MDR and produce most of South FL’s Cat-4+ landfalls. Plus, direct hits from the Atlantic don’t have to weaken over land, unlike late-season hits such as Wilma, which, despite making landfall in SW FL as a Cat-3, produced only TS or low-end Cat-1 conditions in metropolitan SE FL.

I agree with you when it comes to steering favoring Carolina/Mid-Atlantic/Northeast U.S. threats as opposed to East Coast of Florida threats which are very rare to begin with. Still can’t rule out a Irene (1999), Charley (2004), or Wilma like track across the Florida peninsula but I disagree that Wilma only produced TS or low-end Cat.1 winds here in S.FL.

OK lets not get crazy. Tracks into GA are very rare. Not E Coast of FL

Anywhere north of Palm Beach County it’s rare to get a direct hurricane landfall, especially NE Florida. Not as rare in SE Florida but it doesn’t happen too often.

[AutoPenalti]

Ridge pretty much in place, will be interesting to see how this evolves during ASO.

[Emmett_Brown]

Over the years I have noticed that overall patterns, while somewhat important, don't have much bearing on where a storm actually tracks. I have seen patterns where ridges are persistent all season, only to break down allowing a storm to recurve at the last minute, and vice versa where persistent troughing quickly changes to ridging at just the right time to prevent recurvature. Not saying that discussing patterns isn't interesting; just that they don't matter that much until you are in the 5 day window before landfall.

[Monsoonjr99]

Even if the general pattern during part of a season supports more landfalls or more recurves, it never completely rules out the other possibility. Whatever the ridge placement or troughiness entails is just a greater or lesser probability of recurves or landfalls. CV hurricanes can still hit Florida in a generally troughy year if the short-term pattern sets up right. Likewise with a strong ridge, MDR storms recurving is still climatologically favored. Never mind that the pattern can often change mid-season and that troughs in October put Florida at greater risk of landfalls from the SW.

p.s. Wilma still had a monstrous impact in Florida even if a small portion of the Miami-Dade metro didn't have winds that strong. It's like saying Maria wasn't that bad because it didn't directly hit Martinique. Just because a significant storm hasn't hit your small patch of land in a long time doesn't mean you shouldn't take threats seriously. Nor should you believe that a certain pattern precludes a significant impact because a small sample of historical storms with that pattern were only close calls.