2023 Atlantic Hurricane season

[lilj4425]

I didn’t even know there was a Gert. When did that happen? 

[WestMichigan]

I think if a bird flapped its wings in the midst of a cloud swirl they might consider naming it right now.

[NorthHillsWx]

Comparison between the basins:

EPAC: 8 storms, ACE 104

N Atlantic: 8 storms, ACE 17

[GaWx]

 So this thread went from discussion just yesterday of the NHC being too slow to upgrade to the exact opposite today. 
 

 From yesterday: "The NHC’s lack of propensity to name obvious tropical cyclones is starting to get annoying.  It took them far too long to name Emily and the day before TD 6.  Just because it’s in the open ocean doesn’t mean you don’t initiate advisories when it’s an obvious TC."

 But I do agree that Gert is no longer a TC.

[WxWatcher007]

Rather than screwing up the formatting, just reposting. 

5 minutes ago, WxWatcher007 said:

WxWatcher007 2023 Atlantic Peak Season Forecast

Finally, I have the time to share my annual thoughts on the peak of the Atlantic hurricane season. This is my fifth annual forecast and the lead up to today has seen very significant uncertainty on the tenor of the season. The season so far has actually been normal in number of storms and ACE to date, which means active for a Nino. As I write, we suddenly have a TC outbreak in the Atlantic. 

The switch is definitely flipping in the basin. 

Each year on August 20, the late Dr. William Gray and his team would ring a bell, symbolizing the start of peak season. This year, we have a historically warm basin battling a Nino that is gradually increasing in influence.

What does the August 20 - October 20 period hold? Here's my forecast. 

Peak Season Forecast (Aug 20-Oct 20)
Named Storms: 13 
Hurricanes: 6
Major Hurricanes: 3

Emily, Franklin, and Gert became named storms yesterday. Had I posted on the 20th, I would have forecast Emily and Franklin to develop, but not Gert. As a result, my verification will include that. The forecast also predicts PTC 9 and Invest 92L to become NS. That's already pretty active. 

With the current outbreak, I think the risk of a below normal season has diminished. I expect this active window to be confined to the next 4 weeks, with a sharp drop off in activity by September 20. That doesn't mean we can't/won't have NS/H/MH during the late period, but I think at that point, the evolving MJO and Nino will start closing things down. 

Over the past four seasons, I've done well with my forecasts. I view being within +/- 1 as a success, with points off the greater the error. I earned a B+ in 2019, A- in 2020, a disappointing C in 2021, and a rebounding B- in 2022. 

As a reminder, the historical average is 14/7/3. With this peak season forecast I am now forecasting an overall 18/7/3 with more NS than normal, a normal hurricane number, and normal MH number due to decreasing shear during the peak and the exceptionally warm basin even in the central Atlantic. I see ACE around normal. 

1. ENSO
After a three year Nina, we're solidly in an El Nino regime. Of course, every ENSO event is different, and intensity/location matters a lot. Given what I project (and I will admit I am not as good with the intensity/location stuff) and what I've seen so far, the fundamental atmospheric response in the Atlantic that allows for anomalously high shear through the basin has not yet occurred, despite the shear in the basin currently. During the peak guidance actually shows a decrease in shear, but the influence of the Nino should eventually increase, bringing a wind down of activity around the basin (particularly the Caribbean) approximately four weeks from now.   

2. West African Monsoon
The WAM has shown mixed signals so far this season, but now that we're entering the peak it is ramping up. We've seen numerous strong African Easterly Waves (AEWs) that have rolled off Africa, and if the GFS Ensembles are to be believed, it should continue through at least early September. With CV season coming, this is essential to the forecast, even if the MDR remains somewhat hostile with subsidence because it provides a launching point for strong waves to survive the trek into the western Atlantic where there may be more favorable conditions depending on shear.

 

3. Wind Shear
For the most part, shear has been the opposite of what you'd expect for a Nino. Recently it has gotten much worse, but that hasn't stopped development across the basin. It has, however, limited intensity potential, which is part of the reason why I am not interested in going above normal on H or MH numbers.

 

I do think we're going to continue having issues with TUTTs, but I don't anticipate the incredibly consistent wave breaking we saw last year that really capped potential in the basin. There is fairly high confidence in this, given the agreement by the ensembles and the seasonal trend thus far. 

 

Eventually I think the Nino will take over, but not until the damage has been done.  

 

4. SST Anomalies/OHC
If we didn't have the extraordinary SST anomalies and OHC dominating the basin, this would undoubtably be a BN season. This has really allowed for the early MDR NS, marginal activity in the basin in the face of shear/dry air, and for Don to become our first hurricane in July. It is historic warmth, and while SSTs are not the piece that drives a season, they are an essential piece. 

 

 

5. SAL & Stability
The check on the season so far hasn't been shear, it has been SAL and stability. After being historically low earlier in the season, SAL came back with a vengeance in July and August, stabilizing much of the basin and completely closing down even cloud development in the MDR. In fact, vertical instability has been well below climo all year in the tropical Atlantic. 

Times are changing though. SAL is on the decline as we reach the peak of the season, as is usually the case. The sacrificial waves, which all became named storms along the monsoon trough, has dramatically decreased SAL and moistened the environment around the basin, further increasing confidence in an active month ahead. I can't embed the gif, but the link is below. 

https://tropic.ssec.wisc.edu/real-time/sal/g16split/movies/goes16split.html

5. CCKW/MJO
Finally, although we can't see very far, we do also have another factor making an active month more likely. It looks like we are getting favorable passage of a CCKW and the MJO looks to be on the side of Atlantic activity for the next few weeks. This should continue to promote vigorous waves. Not all will develop, but it should keep moistening the MDR and allow for waves to get further west.

Overall
I didn't want to go big, because we still don't know how much shear and stability will truly subside in the coming weeks. Honestly, before this week I was leaning BN overall. With the current state of the Atlantic however and a more favorable period coming aside from the annual start of the climatological peak, I do believe we see an active period that gets us to near normal before a decline after September 20 and an abrupt end by October 20. 

I do think that we see a lot of named storms, but because I am hedging a little more conservative I think we have fewer hurricane chances of those NS. That said, the ones that do become hurricanes will have a chance to become majors, leaving me to predict that 3 of the 6 hurricanes I project developing become majors. 

Final Note--Landfall Odds
The past three years have seen high end storms landfall in the US, and I don't think that changes this year. With higher activity comes a greater statistical chance of a US landfall, and I do believe we have a fourth consecutive year with a major hurricane landfall in the continental United States. 

We'll see what happens. Happy tracking. 

 

[NorthHillsWx]

That GFS run was … scary 

[Kevin Reilly]

2 minutes ago, NorthHillsWx said:

That GFS run was … scary 

How was it scary?  

[NorthHillsWx]

11 minutes ago, Kevin Reilly said:

How was it scary?  

Multiple long track waves across a moistened central Atlantic with a significant decrease in shear + lack of TUTTS after Franklin is sucked north. And, a very strong mid Atlantic ridge building through end of run meaning less escape routes for anything to make it north. Never mind the Andrew-like storm that hits Florida and the Gulf as a major with another strong hurricane being pushed west beneath that ridge and another likely storm coming off the coast of Africa at the end of the run. Pretty much squashed all of the inhibiting factors of the season thus far and shows some strong storms with westward tracks as it does so 

[LongBeachSurfFreak]

11 minutes ago, NorthHillsWx said:

Multiple long track waves across a moistened central Atlantic with a significant decrease in shear + lack of TUTTS after Franklin is sucked north. And, a very strong mid Atlantic ridge building through end of run meaning less escape routes for anything to make it north. Never mind the Andrew-like storm that hits Florida and the Gulf as a major with another strong hurricane being pushed west beneath that ridge and another likely storm coming off the coast of Africa at the end of the run. Pretty much squashed all of the inhibiting factors of the season thus far and shows some strong storms with westward tracks as it does so 

If the shear does relax and the Atmosphere looses that SAL, then yeah, it’s game time. Right in time for peak climo, so with OHC at record highs basin wide…. Watch out 

[Ed, snow and hurricane fan]

I think there is a real chance for a hurricane, possibly a long tracked major, the end of the month and the beginning of September.  The Atlantic ridge this far W, Florida, and the SE USA, would be favored.  GFS ensembles not radically different although beyond 240 hours has less of the Atlantic ridge into the Gulf than the Euro ensembles do.

 

Euro ensembles, go out to 2 weeks, the Atlantic ridge is nosing even further W, opening up much of the Gulf to long tracked MDR storms. 

[Tezeta]

12 minutes ago, Ed, snow and hurricane fan said:

I think there is a real chance for a hurricane, possibly a long tracked major, the end of the month and the beginning of September.  The Atlantic ridge this far W, Florida, and the SE USA, would be favored.  GFS ensembles not radically different although beyond 240 hours has less of the Atlantic ridge into the Gulf than the Euro ensembles do.

 

Euro ensembles, go out to 2 weeks, the Atlantic ridge is nosing even further W, opening up much of the Gulf to long tracked MDR storms. 

whats the deal with popos beach pad? is that still a thing?

[Ed, snow and hurricane fan]

8 minutes ago, Tezeta said:

whats the deal with popos beach pad? is that still a thing?

Popo passed away, his daughter and her husband have the place.  For whatever reason, I have not been waist deep in 85F water trying to catch a small shark or a redfish this year.  Only once last summer.

 

I don't really expect it, but out 2 weeks, the Euro ensemble would seem to have the entire Gulf at risk.  The odds that during a brief window, any particular place is hit with a hurricane is pretty low.  When I say 10 days from now Florida has a risky pattern, I don't pick a particular city.  

 

We had an excuse in 2009 not to go to GLS, there was no place to go.  This summer, both my wife's grandparents are dead, they invited us down often, my wife's aunt hasn't invited us lately.

[TheDreamTraveler]

6 hours ago, lee59 said:

Years ago this would have been a very quiet season and way lower in the alphabet with named storms. Now with better technology and naming subtropical storms, we go thru the alphabet a lot faster.

You mean decades ago right? Satellite era since the 1970s has made it incredibly easy to catch storms that otherwise would have been missed. That's why I'm very curious what the 1933 record season would have been with satellites.

[lee59]

3 hours ago, TheDreamTraveler said:

You mean decades ago right? Satellite era since the 1970s has made it incredibly easy to catch storms that otherwise would have been missed. That's why I'm very curious what the 1933 record season would have been with satellites.

I think even with the satellite era we have become a lot quicker at naming storms that may not have been named in the past. Now even subtropical are named. Before the satellite era, who knows how many were missed.

[Ed, snow and hurricane fan]

Not clear on GFS ensembles, but Euro ensembles have a pretty clear signal of something coming from the Caribbean (maybe from the East Pac) into the Gulf impacting anywhere from Louisiana to Florida.  The op Euro also shows it.

[WxWatcher007]

2 hours ago, Ed, snow and hurricane fan said:

Not clear on GFS ensembles, but Euro ensembles have a pretty clear signal of something coming from the Caribbean (maybe from the East Pac) into the Gulf impacting anywhere from Louisiana to Florida.  The op Euro also shows it.

Yeah this is from that EPAC monsoon trough/CAG feature I started highlighting last Wednesday. Models have been lukewarm until the euro brought it back last night. I thought last week that had the highest potential for the final week of August, but even with last nights run the euro remains an outlier. 

The MT is there, but no guarantees anything crosses over. NHC not highlighting any contenders either. It’s really just wait and see like the Atlantic MT was?

https://tropic.ssec.wisc.edu/real-time/atlantic/movies/wg8vor4/wg8vor4_loop.html

[WxWatcher007]

[Normandy]

I would watch the area north of Panama right now.  Tons of convection and a lot of surface convergence.  It appears this might be a piece of energy that was shed westward out of franklins intense convective bursts yesterday and last night

[Ed, snow and hurricane fan]

Dr. Andy Hazelton tweeted the Euro and its ensembles in its latest form tend to keep low level vorticity too high when systems are crossing land, or he thinks the Pacific MT to Caribbean to Gulf chances are low.  He doesn't say impossible, just not likely.

Derek Ortt, with an MS in meteorology noted a little later, about the same W. Caribbean system, noted GFS and ensembles were slow on Harold, only predicting development a couple of days before it happened.  He said the GFS for tropical genesis was for comedy only.  They weren't responding to each other.

GFS ensembles aren't completely ignoring the W. Caribbean situation, but are much less enthusiastic.  18Z GFS ensembles have a few members in the BOC after 10 days, I'm not certain whether that is a slightly delayed development of the system the 0Z Euro and many of its ensembles like.

 

 

[MANDA]

Emily, Gert and Harold had a combined total of 1.4 ACE points.  Just throwing it out there for those of us who care about such things.

IMO Gert was a waste of a name.  At best was a borderline Tropical Cyclone and TPC held onto the designation way beyond what it should have been if it ever should have been.

Emily was legit for a short time as was Harold.  I suspect if Harold had about another 12 hours over water would have reached Hurricane status.  Looked good coming onshore based on radar and satellite.

Lots of names but not much sizzle so far this season.

[GaWx]

6 hours ago, MANDA said:

Emily, Gert and Harold had a combined total of 1.4 ACE points.  Just throwing it out there for those of us who care about such things.

IMO Gert was a waste of a name.  At best was a borderline Tropical Cyclone and TPC held onto the designation way beyond what it should have been if it ever should have been.

Emily was legit for a short time as was Harold.  I suspect if Harold had about another 12 hours over water would have reached Hurricane status.  Looked good coming onshore based on radar and satellite.

Lots of names but not much sizzle so far this season.

 Don was impressive and an overachiever vs expectations.

[MANDA]

7 hours ago, GaWx said:

 Don was impressive and an overachiever vs expectations.

For longevity for sure, tracked for 10 days.  Intensity was ho-hum and it was out of the deep tropics.  Still counts I get it but so far this season we've seen mainly weak and short lived systems.  Says much about how unfavorable things have been atmospherically speaking.  Franklin only hope in the coming days of racking up some ACE points.  We'll see what condition he is in after emerging from DR/Haiti.

[Torch Tiger]

12z Euro has a decent TC striking the Big Bend FL area 8/30 just after 12z.  The SST's are above normal and already pretty much maxed out, so that could be interesting.

[NorthHillsWx]

Not the most important thing to focus on at this point in the season, but several runs of the GFS already bring the 540 line down into eastern Canada and have shown snow pretty far south. Hopefully a harbinger of an early end to the season with El Niño taking over 

[Stormchaserchuck1]

15-day GFS ensembles are going all out -PNA though, which may put a ridge over the SE, US in time for a part of peak season. If a ridge sets up over the NE/SE Canada, that makes Gulf and SE landfalls more likely. 

[Ed, snow and hurricane fan]

1 hour ago, Stormchaserchuck1 said:

15-day GFS ensembles are going all out -PNA though, which may put a ridge over the SE, US in time for a part of peak season. If a ridge sets up over the NE/SE Canada, that makes Gulf and SE landfalls more likely. 

It seems to me there are few patterns where some part of Florida isn't at risk of a TC landfall June to mid November.

[NorthHillsWx]

GEFS tends to keep the eastern trough into the beginning of September while EPS tends to weaken it with a turn to SE ridging to start the month. These two divergent solutions offer extremely different outlooks towards the prospect of a east coast landfall and with an extremely active basin (from a wave standpoint) this needs to be watched as to which solution comes to fruition. Does the GEFS solution of keeping a trough continue to offer a barrier to storms like Franklin or does the trough breakdown and offer a window for storms to move further west and threaten the EC? Will need to be watched for trends over the coming days. My thoughts are leaning towards a window of opportunity during the September 3-10 timeframe for an east coast threat. I still think homegrown or gulf systems are the mode of getting a storm to threaten the US but that is looking like a window for something to slip through from the east 

[hawkeye_wx]

The Euro continues to meander some 500 mb vorticity just off the Yucatan coast over the weekend.  Even though it also shows an upper ridge centered over that area, it struggles to develop anything until the energy lifts into the gulf.

[GaWx]

2 hours ago, hawkeye_wx said:

The Euro continues to meander some 500 mb vorticity just off the Yucatan coast over the weekend.  Even though it also shows an upper ridge centered over that area, it struggles to develop anything until the energy lifts into the gulf.

This GOM threat is a tough one to predict. Whereas there's good model agreement for something, I have to go all of the way back to storm #6 of 1880 to find an El Niño with a similar track in either late Aug or early Sep:

 
 Meanwhile, the 0Z UKMET had a TD form in the W Caribbean and then move NE over S FL. The 12Z will be out shortly.

[GaWx]

The 12Z UKMET (typically overly conservative model) is significantly stronger than the 0Z with the W Car/GOM TC (partially due to being over water longer) with a TS instead of just a TD and 10 mb lower SLP. Also, instead of it moving NE across S FL, it moves NE from the FL Big Bend across N FL into the Atlantic:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER  72 HOURS
              FORECAST POSITION AT T+ 72 : 20.9N  86.3W

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    1200UTC 27.08.2023   72  20.9N  86.3W     1005            22
    0000UTC 28.08.2023   84  21.2N  85.7W     1003            24
    1200UTC 28.08.2023   96  22.8N  84.8W     1002            36
    0000UTC 29.08.2023  108  24.8N  83.7W     1000            36
    1200UTC 29.08.2023  120  27.2N  83.6W      997            38
    0000UTC 30.08.2023  132  28.6N  83.4W      994            37
    1200UTC 30.08.2023  144  30.3N  82.1W      994            40
    0000UTC 31.08.2023  156  32.3N  79.5W      993            41
    1200UTC 31.08.2023  168  34.4N  77.1W      996            39