Expert forecasts for 2023 North Atlantic Hurricane Season

[Hurricane2022]

 https://twitter.com/philklotzbach/status/1676970759158214656

[psyclone]

Phil seems to imply that the warm Atlantic conditions can blunt nino induced shear. I've not really heard that before. To what extent is this the case?

[wxman57]

When I talked with Phil yesterday, I told him that his numbers appeared a little hurricane-heavy at 14/9/4 for the remainder of the season. There are so many weak, short-lived storms these days that the number of hurricanes is become less than half of the total named storms. We're pretty close with the numbers, though. When I asked him about the analogs, he said there really wasn't any good analog. The 1951 season keeps coming up as an analog, though. That was a rather quiet season, though. Bottom line is I don't think anyone is very confident in the outlook for the rest of the season. Early on (April to early June), the MDR was much more favorable for development with very light trades. Now, the trades have picked way up and SSTs are cooling due to upwelling. Current waves are struggling to survive in the MDR.

Waves are suppose to struggle now its peak SAL time in a typical season there is 0 till mid Aug. Again we are in uncharted territory with this record warm Atl and enso coming on we shall see what happens.

My point was that Bret and Cindy were flukes, not a sign that the MDR would be active over the next month or so. There was a brief period when the MDR was semi-favorable. That period is gone.

[SFLcane]

One thing thats very interesting is were it matters 82 ace west of 60 W on Phils July update.

[USTropics]

Phil seems to imply that the warm Atlantic conditions can blunt nino induced shear. I've not really heard that before. To what extent is this the case?

While when an El Nino occurs, it typically leads to the suppression of Atlantic hurricane activity due to changes in atmospheric circulation patterns, if the Atlantic sea surface temperatures remain warm, it can counteract some of the inhibiting effects of El Nino and maintain or even enhance tropical storm activity. Mainly we are looking for shifts in atmospheric circulations, such as the weakening of the Atlantic trade winds (or even reversal in extreme El Nino events). These weakened winds can make it more difficult for tropical storms to develop and intensify. However, if the Atlantic sea surface temperatures are anomalously warm, they can induce local circulation patterns that partially compensate for the weakening of the trade winds (and currently we're not seeing a fully coupled ocean-atmosphere event). This can help maintain or enhance the conditions necessary for tropical storm formation and intensification, thereby reducing the impact of El Niño.

It's important to note that while warm Atlantic sea surface temperatures can help counteract the effects of El Nino on tropical storms, they do not completely eliminate those effects. El Nino is a complex climate phenomenon that influences global weather patterns, and its impacts can still be felt even in the presence of warm Atlantic waters. Additionally, other factors, such as wind shear and atmospheric stability, also play important roles in determining tropical storm activity. While not always the case, it's also important to note that the onset of El Nino typically begins in the spring/summer; it's not until the boreal seasonal shifts to fall/winter where El Nino events can become particularly robust. As mentioned above, we aren't seeing a fully coupled event yet (personally I would expect an active east Atlantic and MDR, but suppressed activity in the Caribbean/western GOM).

[toad strangler]

When I talked with Phil yesterday, I told him that his numbers appeared a little hurricane-heavy at 14/9/4 for the remainder of the season. There are so many weak, short-lived storms these days that the number of hurricanes is become less than half of the total named storms. We're pretty close with the numbers, though. When I asked him about the analogs, he said there really wasn't any good analog. The 1951 season keeps coming up as an analog, though. That was a rather quiet season, though. Bottom line is I don't think anyone is very confident in the outlook for the rest of the season. Early on (April to early June), the MDR was much more favorable for development with very light trades. Now, the trades have picked way up and SSTs are cooling due to upwelling. Current waves are struggling to survive in the MDR.

Waves are suppose to struggle now its peak SAL time in a typical season there is 0 till mid Aug. Again we are in uncharted territory with this record warm Atl and enso coming on we shall see what happens.

My point was that Bret and Cindy were flukes, not a sign that the MDR would be active over the next month or so. There was a brief period when the MDR was semi-favorable. That period is gone.

Interesting that you see the two June MDR systems as flukes. I tend to agree with that sentiment. There is another camp though that feels the anomalous June systems are a harbinger of activity during the peak months. Going to be interesting for sure!

[weeniepatrol]

Waves are suppose to struggle now its peak SAL time in a typical season there is 0 till mid Aug. Again we are in uncharted territory with this record warm Atl and enso coming on we shall see what happens.

My point was that Bret and Cindy were flukes, not a sign that the MDR would be active over the next month or so. There was a brief period when the MDR was semi-favorable. That period is gone.

Interesting that you see the two June MDR systems as flukes. I tend to agree with that sentiment. There is another camp though that feels the anomalous June systems are a harbinger of activity during the peak months. Going to be interesting for sure!

Normally it's a near slam-dunk, BUT this year has the fly in the ointment of El Nino, so it's incredibly tricky.

[Ntxw]

My point was that Bret and Cindy were flukes, not a sign that the MDR would be active over the next month or so. There was a brief period when the MDR was semi-favorable. That period is gone.

Interesting that you see the two June MDR systems as flukes. I tend to agree with that sentiment. There is another camp though that feels the anomalous June systems are a harbinger of activity during the peak months. Going to be interesting for sure!

Normally it's a near slam-dunk, BUT this year has the fly in the ointment of El Nino, so it's incredibly tricky.

Both can be true. There can be periods of favorable conditions, should waves be in the right areas, and strengthen via warmer SSTs assistance compared to more natural cool SSTs. At the same time, there can be periods of higher shear due to ENSO and limiting seasonal ceiling at the same time. It doesn't have to be one way or the other. Giving forecasters, a little less confidence.

[zzzh]

https://www.tropicalstormrisk.com/docs/TSRATLForecastJuly2023.pdf
TSR July forecast is out. 17/8/3 ace 125.

[cycloneye]

The reasons to increase the numbers from 13/6/2 to 17/8/3.

Summary: The TSR (Tropical Storm Risk) July forecast update for North Atlantic hurricane activity in
2023 raises its forecast and now anticipates a season with activity close to the 1991-2020 climate norm.
Although uncertainties remain, we consider that the more likely scenario is for tropical North Atlantic
and Caribbean Sea waters to be warmer than normal by August-September 2023, and for moderate El
Niño conditions to persist through August-September 2023 and into the autumn. These two factors are
expected to have opposing influences on the Atlantic hurricane season, however we anticipate the warm
sea surface temperatures in the Atlantic will partially override the increased vertical wind shear and trade
wind strength normally present during El Niño. An additional factor favouring high activity in 2023 than
anticipated in late May is the development of two tropical storms in the Atlantic Main Development
Region (MDR) in June which is exceptional and implies the tropical Atlantic has become favourable for
development much earlier than normal

[Hybridstorm_November2001]

I'm very skeptical of an above-average season in particular of a much above-average season given the inhibiting factor of an established El Nino, but we'll see. It'll be a battle between which factors win out upper-level wind sheer generated by El Nino or higher oceanic heat content in the MDR and elsewhere.

[LarryWx]

7/9/23 update of tropical seasonal outlook from meteorologist Larry Cosgrove:

"Despite what you may have heard, the potential for serious tropical cyclone development is decreasing. Low-latitude westerlies in the Atlantic Basin have still not lifted out, and with each passing day the chance for an extended "window" of favorable heat ridge positioning decreases. Another factor that is influencing the lack of convective production outside of Africa (despite an active ITCZ) is tremendous amounts of Saharan dust, concurrent with very low dewpoints and high temperatures.

Warm waters in the Major Development Region do not alter or break the wind patterns associated with extreme warmth of the 1.2 ENSO sector. At some point the giant ridge complex (which will reach its apex in the last week of July), will weaken and some easterlies will set up from western Africa. But we are running out of time for that synoptic event to happen! Because at some point in late August the flow signatures will reset to west/southwest, shearing thunderstorm tops apart. For now I will keep my forecast total of 13 named storms, 5 hurricanes, and one major cyclone intact. But do not be surprised if a revision is announced."

[cycloneye]

7/9/23 update of tropical seasonal outlook from meteorologist Larry Cosgrove:

"Despite what you may have heard, the potential for serious tropical cyclone development is decreasing. Low-latitude westerlies in the Atlantic Basin have still not lifted out, and with each passing day the chance for an extended "window" of favorable heat ridge positioning decreases. Another factor that is influencing the lack of convective production outside of Africa (despite an active ITCZ) is tremendous amounts of Saharan dust, concurrent with very low dewpoints and high temperatures.

Warm waters in the Major Development Region do not alter or break the wind patterns associated with extreme warmth of the 1.2 ENSO sector. At some point the giant ridge complex (which will reach its apex in the last week of July), will weaken and some easterlies will set up from western Africa. But we are running out of time for that synoptic event to happen! Because at some point in late August the flow signatures will reset to west/southwest, shearing thunderstorm tops apart. For now I will keep my forecast total of 13 named storms, 5 hurricanes, and one major cyclone intact. But do not be surprised if a revision is announced."

That is a big contrast from what CSU / TSR had in their July outlooks.

[LarryWx]

7/9/23 update of tropical seasonal outlook from meteorologist Larry Cosgrove:

"Despite what you may have heard, the potential for serious tropical cyclone development is decreasing. Low-latitude westerlies in the Atlantic Basin have still not lifted out, and with each passing day the chance for an extended "window" of favorable heat ridge positioning decreases. Another factor that is influencing the lack of convective production outside of Africa (despite an active ITCZ) is tremendous amounts of Saharan dust, concurrent with very low dewpoints and high temperatures.

Warm waters in the Major Development Region do not alter or break the wind patterns associated with extreme warmth of the 1.2 ENSO sector. At some point the giant ridge complex (which will reach its apex in the last week of July), will weaken and some easterlies will set up from western Africa. But we are running out of time for that synoptic event to happen! Because at some point in late August the flow signatures will reset to west/southwest, shearing thunderstorm tops apart. For now I will keep my forecast total of 13 named storms, 5 hurricanes, and one major cyclone intact. But do not be surprised if a revision is announced."

That is a big contrast from what CSU / TSR had in their July outlooks.

Indeed! This strong contrast between forecasts this season from those feeling El Niño will dominate (bearish)
to those feeling the very warm Atlantic will dominate (bullish) as well as those in between will continue to make for very interesting discussions and debates. This is when forecast discussion threads are most enjoyable. When most everyone agrees, the forecast discussions aren't as interesting to me.

[SFLcane]

7/9/23 update of tropical seasonal outlook from meteorologist Larry Cosgrove:

"Despite what you may have heard, the potential for serious tropical cyclone development is decreasing. Low-latitude westerlies in the Atlantic Basin have still not lifted out, and with each passing day the chance for an extended "window" of favorable heat ridge positioning decreases. Another factor that is influencing the lack of convective production outside of Africa (despite an active ITCZ) is tremendous amounts of Saharan dust, concurrent with very low dewpoints and high temperatures.

Warm waters in the Major Development Region do not alter or break the wind patterns associated with extreme warmth of the 1.2 ENSO sector. At some point the giant ridge complex (which will reach its apex in the last week of July), will weaken and some easterlies will set up from western Africa. But we are running out of time for that synoptic event to happen! Because at some point in late August the flow signatures will reset to west/southwest, shearing thunderstorm tops apart. For now I will keep my forecast total of 13 named storms, 5 hurricanes, and one major cyclone intact. But do not be surprised if a revision is announced."

Multiple agencies now on the same page forecasting a very busy season could they all bust Sure. I think I will side with Phil who has been doing seasonal outlooks for 20+ years. Seasonal outlook isn’t made just by looking at warm water plenty other factors go into it. Surely these outlooks don’t tell you we’re they will track that’s something that can’t be forecasted months out. You should prepare the same regardless every year. Plenty of devastating hurricanes have hit the conus even in the strongest of El Niños.

[LarryWx]

7/9/23 update of tropical seasonal outlook from meteorologist Larry Cosgrove:

"Despite what you may have heard, the potential for serious tropical cyclone development is decreasing. Low-latitude westerlies in the Atlantic Basin have still not lifted out, and with each passing day the chance for an extended "window" of favorable heat ridge positioning decreases. Another factor that is influencing the lack of convective production outside of Africa (despite an active ITCZ) is tremendous amounts of Saharan dust, concurrent with very low dewpoints and high temperatures.

Warm waters in the Major Development Region do not alter or break the wind patterns associated with extreme warmth of the 1.2 ENSO sector. At some point the giant ridge complex (which will reach its apex in the last week of July), will weaken and some easterlies will set up from western Africa. But we are running out of time for that synoptic event to happen! Because at some point in late August the flow signatures will reset to west/southwest, shearing thunderstorm tops apart. For now I will keep my forecast total of 13 named storms, 5 hurricanes, and one major cyclone intact. But do not be surprised if a revision is announced."

Multiple agencies now on the same page forecasting a very busy season could they all bust Sure. I think I will side with Phil who has been doing seasonal outlooks for 20+ years. Seasonal outlook isn’t made just by looking at warm water plenty other factors go into it. Surely these outlooks don’t tell you we’re they will track that’s something that can’t be forecasted months out. You should prepare the same regardless every year. Plenty of devastating hurricanes have hit the conus even in the strongest of El Niños.

Island and coastal residents, especially, should be prepared every season! Even a relatively inactive season can be devastating to someone personally.

[JetFuel_SE]

7/9/23 update of tropical seasonal outlook from meteorologist Larry Cosgrove:

"Despite what you may have heard, the potential for serious tropical cyclone development is decreasing. Low-latitude westerlies in the Atlantic Basin have still not lifted out, and with each passing day the chance for an extended "window" of favorable heat ridge positioning decreases. Another factor that is influencing the lack of convective production outside of Africa (despite an active ITCZ) is tremendous amounts of Saharan dust, concurrent with very low dewpoints and high temperatures.

Warm waters in the Major Development Region do not alter or break the wind patterns associated with extreme warmth of the 1.2 ENSO sector. At some point the giant ridge complex (which will reach its apex in the last week of July), will weaken and some easterlies will set up from western Africa. But we are running out of time for that synoptic event to happen! Because at some point in late August the flow signatures will reset to west/southwest, shearing thunderstorm tops apart. For now I will keep my forecast total of 13 named storms, 5 hurricanes, and one major cyclone intact. But do not be surprised if a revision is announced."

Multiple agencies now on the same page forecasting a very busy season could they all bust Sure. I think I will side with Phil who has been doing seasonal outlooks for 20+ years. Seasonal outlook isn’t made just by looking at warm water plenty other factors go into it. Surely these outlooks don’t tell you we’re they will track that’s something that can’t be forecasted months out. You should prepare the same regardless every year. Plenty of devastating hurricanes have hit the conus even in the strongest of El Niños.

Island and coastal residents, especially, should be prepared every season! Even a relatively inactive season can be devastating to someone personally.

1983's Alicia and 1992's Andrew are good examples.

[LarryWx]

Multiple agencies now on the same page forecasting a very busy season could they all bust Sure. I think I will side with Phil who has been doing seasonal outlooks for 20+ years. Seasonal outlook isn’t made just by looking at warm water plenty other factors go into it. Surely these outlooks don’t tell you we’re they will track that’s something that can’t be forecasted months out. You should prepare the same regardless every year. Plenty of devastating hurricanes have hit the conus even in the strongest of El Niños.

Island and coastal residents, especially, should be prepared every season! Even a relatively inactive season can be devastating to someone personally.

1983's Alicia and 1992's Andrew are good examples.

Indeed! I can also add 1977 (Anita), 1965 (Betsy) 1929 (Bahamas/S FL), 1919 (FL Keys/S TX), and 1918 (W La). These were all either during or just before an incoming El Niño.

[IsabelaWeather]

7/9/23 update of tropical seasonal outlook from meteorologist Larry Cosgrove:

is tremendous amounts of Saharan dust,

Im confused, the SAL hasnt been very impressive this year. Its also here every single year...

[LarryWx]

7/9/23 update of tropical seasonal outlook from meteorologist Larry Cosgrove:

is tremendous amounts of Saharan dust,

Im confused, the SAL hasnt been very impressive this year. Its also here every single year...

Indeed, SAL was at record lows for early June. It has recently picked up considerably, but July is near the climo peak as you're implying and thus it may still only be near average for July. I asked about that in the 2023 Indicators thread after a forecasted SAL map for this week was posted. It appears widespread but don't know if that's far from mid July normal, which is near climo peak.