2019 Indicators: SST'S / Sal / MSLP / Steering / Shear / Instability (See updated graphics at first post)

[Tampa Bay Hurricane]

These bold predictions including those by Several Experts of no hurricanes or storms forming have been proven wrong again and again going back to 2017. There will certainly be many named storms and several hurricanes between now and September 30. There will be a spike in activity like there is every year. Where they go is the mystery.

[SFLcane]

I would like to point out the EPS temperature anomalies though somewhat speculative for September imply east coast ridging in the mean.

[jconsor]

 https://twitter.com/yconsor/status/1158705900695240709

[cycloneye]

Another bearish twit.

 https://twitter.com/AndyHazelton/status/1158743308056911873

[rickybobby]

Looks like it’ll be a quiet season for Florida.

[NotSparta]

Looks like it’ll be a quiet season for Florida.

I hope so, but it's too early to say that

[Tampa Bay Hurricane]

Looks like it’ll be a quiet season for Florida.

My friend There is no way to know that. It was quiet in Florida until early September of 2017 and then we had Irma. It was quiet until September 2018 and then we got Gordon followed by Michael cat 5 in October.

[tolakram]

We've been here before, and archived data is easier than ever to look at.

SLIDER 2018 water vapor. Be sure to change the bands to see the dust as well.

http://rammb-slider.cira.colostate.edu/?sat=goes-16&z=1&im=12&ts=1&st=20180806130045&et=20180806144545&speed=130&motion=loop&map=1&lat=0&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=0&mouse_draw=0&follow_feature=0&follow_hide=0&s=rammb-slider&sec=full_disk&p%5B0%5D=band_08&x=11238.14404296875&y=7413.4661865234375

EURO 05AUG2018 run: https://weather.us/model-charts/euro/2018080600/grid-americas/sea-level-pressure/20180806-0000z.html

I have NO confidence of any model forecast in early August. Last year we had Debby and Ernesto, 2 very short lived tropical storms. If we don't have any storms this August it means a record falls, and not much more.

[toad strangler]

Looks like it’ll be a quiet season for Florida.

[SoupBone]

We've been here before, and archived data is easier than ever to look at.

SLIDER 2018 water vapor. Be sure to change the bands to see the dust as well.

http://rammb-slider.cira.colostate.edu/?sat=goes-16&z=1&im=12&ts=1&st=20180806130045&et=20180806144545&speed=130&motion=loop&map=1&lat=0&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=0&mouse_draw=0&follow_feature=0&follow_hide=0&s=rammb-slider&sec=full_disk&p%5B0%5D=band_08&x=11238.14404296875&y=7413.4661865234375

EURO 05AUG2018 run: https://weather.us/model-charts/euro/2018080600/grid-americas/sea-level-pressure/20180806-0000z.html

I have NO confidence of any model forecast in early August. Last year we had Debby and Ernesto, 2 very short lived tropical storms. If we don't have any storms this August it means a record falls, and not much more.

We also know that while the death ridge over Texas can and has protected us, it can also erode away, leaving us vulnerable. I hate the heat that the death ridge brings, but I'll take it any day over a hurricane.

[CyclonicFury]

I still think things could get much more interesting after August 20. First, there will be a CCKW passing through the basin, which could result in lower shear over the Atlantic and could enhance the WAM. Second, if the Atlantic sinking branch breaks down as the EPS shows, there could be a burst of activity in September. The next two weeks could be largely dead, but after that, we should see some activity. We usually do.

[Shell Mound]

Interestingly, the updated CSU forecast mentions 1992 (ANDREW) and 2012 (ISAAC, SANDY) as analogs...

The best analog years that we could find for the 2019 hurricane season were 1990, 1992, 2012 and 2014. –CSU, p. 16

There is also this interesting tidbit:

The central tropical Pacific remains very warm, while the eastern tropical Pacific has anomalously cooled (Table 7). Currently, SST anomalies in the Nino 4 region are at near-record warm levels, while SSTs are near average in the Nino 3 region. This anomalous SST gradient pattern is quite unusual in the historical record, with no close comparable analogs since 1950. In general, when Nino 4 is much warmer than Nino 3, it tends to occur in a La Niña situation. –CSU, p. 18

Furthermore:

Anomalously westerly winds near the International Date Line over the past few weeks (Figure 8) have led to continued anomalous warming and deepening of the thermocline in the central tropical Pacific (Figure 9). ... Since overall SSTs are warmer in the central tropical Pacific than in the eastern tropical Pacific, we anticipate that the anomalous warmth near the International Date Line should help focus convection in the central tropical Pacific and thereby increase upper-level westerly winds in the Caribbean. ... However, as noted earlier, regardless of whether the Nino 3.4 region persists in meeting the NOAA El Niño threshold of 0.5°C, we believe that the anomalous warmth in the central tropical Pacific will be a slight inhibiting factor for this year’s Atlantic hurricane season.–CSU, pp. 19-20

Additionally:

July vertical wind shear has generally been above normal over the Caribbean and below normal further east in the tropical Atlantic (Figure 14). There is a strong negative correlation between July vertical wind shear in the Caribbean and seasonal Atlantic ACE, that is, stronger vertical wind shear typically correlates with a quieter overall Atlantic hurricane season. –CSU, p. 25

Contrary to popular perception, the Sahel has dried considerably since earlier in the year:

Enhanced rainfall in the Sahel region of West Africa during July has been associated with active hurricane seasons (Landsea and Gray 1992). Figure 17 displays rainfall estimates over Africa over the past few weeks. In general, rainfall in the western Sahel has been near normal, favoring a near-normal hurricane season. –CSU, p. 29

[galaxy401]

Quite interesting that both the Atlantic and EPAC are quiet right now. Atlantic being quiet isn't a big surprise but the EPAC a little more. Quite the contrast to last year around this time in the basin.

[Hammy]

These bold predictions including those by Several Experts of no hurricanes or storms forming have been proven wrong again and again going back to 2017. There will certainly be many named storms and several hurricanes between now and September 30. There will be a spike in activity like there is every year. Where they go is the mystery.

While I can't speak for anybody else here, I'm not personally forecasting no hurricanes, just pointing out what the models and pretty much every single forecaster linked here are indicating. CFS has been generally reliable as a trend indicator, and often bounces back and fourth between extremes, in 2018 for example going between a near-normal season and hyperactivity--this year it has been bouncing between below normal and nonexistent, especially for August-September. This is likely a good indicator those two months will not produce a whole lot compared to recent years, it would not surprise me to see the MDR quiet the entire season. That combined with the shear from the lingering atmospheric Nino-type conditions, means that an overall below normal peak of the season is far more likely than in recent years when forecasts were made by some out of impatience.

It's all but guaranteed at this point that we're going to be reaching the middle of August with the lowest numbers and ACE since 2009, and it's going to take some pretty extreme activity to make up the numbers if the peak does in fact end up delayed until mid-September.

[jconsor]

Qqiet EPac looks to continue next two weeks, with a few relatively weak TCs but low chances of any intense hurricanes. The relatively quiet EPac (especially relative to climatology for a Nino) appears to be associated with dry air aloft in the Eastern Pacific main development region. Another interesting aspect is that 850 mb winds in Jul in the Caribbean were only slightly below normal and are expected to be near normal Aug-Oct. This is not in keeping with classic Nino climatology.

In both these respects, 2019 is following the 2003 and 2012 analogs well. 2012 was not technically an El Nino but from the end of Jun to early Sep Nino 3.4 averaged around +0.6.

 https://twitter.com/yconsor/status/1157961630787018754

Quite interesting that both the Atlantic and EPAC are quiet right now. Atlantic being quiet isn't a big surprise but the EPAC a little more. Quite the contrast to last year around this time in the basin.

[NDG]

What is surprising this year when the tropical Atlantic is closed for business for now is how quiet the subtropical Atlantic has been since the start of the hurricane season. Anything off of the Carolinas on eastward gets sheared away before any development.

By going by the CSU team by looking at the shear anomaly maps for the month of July over the Caribbean compared to previous years, the Caribbean had higher shear last year than this July and still produced an average to slightly above average season. There is no reason not to think that this year will not be at least an average season before is all set and done because of average EPAC season so far, cool neutral eastern ENSO regions, near average shear across the Atlantic basin overall and warm SSTs across most of the Atlantic Basin. The sinking motion across the Atlantic should be much lower by the time we get to September.

[CyclonicFury]

Shear in the Caribbean in July 2019 was actually considerably lower than most seasons that went on to be El Nino years by fall. The only El Nino year since 2000 to have lower shear in the Caribbean in July than 2019 was 2004, which isn't surprising since 2004 was a weak El Nino Modoki year similar to 2019. However, unlike 2004, 2019 has a much warmer PMM/PDO, as well as a cooler Atlantic MDR. I'm not expecting ENSO to be a major suppressing factor for this season, especially after the end of August if the forecasts of the sinking branch dissipating are correct.

First, here's 2019 (Dissipating Modoki II El Nino):


2002 (Moderate Modoki I El Nino):


2004 (Weak Modoki II El Nino):


2006 (Weak Traditional El Nino):


2009 (Moderate Traditional but transitioned to Modoki El Nino):


2014 (Late-developing Weak El Nino):


2015 (Super El Nino):


2018 (Late-developing Weak El Nino):

[tolakram]

Here's the Caribbean shear chart. Not seeing above normal values on this one.




Tropical Atlantic instability juuust a bit low.


source: https://www.ssd.noaa.gov/PS/TROP/TCFP/atlantic.html

[NotSparta]

 https://twitter.com/webberweather/status/1158865140902768643

[CyclonicFury]

 https://twitter.com/AndyHazelton/status/1158866131995824130