The Pr Philip J. Klotzbach from the University of Colorado Atmospheric Research Department and team have released their 2nd update of their forecast for the 2020 hurricane season.
| Forecast April 2024 | Forecast June 2024 | Prev July 2024 | Prev August 2024 | evol. | Moy | 2023 | 2022 | 2021 | |
|---|---|---|---|---|---|---|---|---|---|
| Nb of named storms | 23 | - | - | - | - | 14.4 | 20 | 14 | 21 |
| Of stormy days | 115 | - | - | - | - | 69.4 | 99 | 56.25 | 78 |
| No. of hurricanes | 11 | - | - | - | - | 7.2 | 7 | 8 | 7 |
| No. of hurricane days | 45 | - | - | - | - | 27 | 31 | 21.25 | 27.5 |
| No. of major hurricanes | 5 | - | - | - | - | 3.2 | 3 | 2 | 4 |
| No. of major hurricane days | 15 | - | - | - | - | 7.4 | 7.75 | 5.75 | 13.5 |
| Cumulative energy (ACE) | 210 | - | - | - | - | 123 | 146 | 95 | 145 |
Summary
I'm not going to lie to you, I was a little worried about this update of the forecast for the 2020 hurricane season in the Atlantic. And unfortunately, in view of the first 2 months of the season, my fears were well founded since this new forecast would place, if it were to come true, the 2020 season in the third place of the most active seasons since 3. Nothing less. only that !
But, as I have said over and over again (for example here) it is not because a forecast is high (and that it is realized) that the West Indies will necessarily be very affected. I would remind you that during the most active season recorded (2005), only one cyclone hit the arc… so let's not sink into paranoia on our French islands!
Details of the update of August 5, 2020
The cyclone forecast updates during the season are based on several parameters: the situation and the evolution of the oscillation ENSO, the situation and evolution of surface water temperatures in the MDR and, of course, the level of activity already recorded.
Unfortunately, and this is probably the most important reason for this development, the forecast ENSO has changed a lot over the past 2 or 3 weeks with a fairly dry descent in the cold neutral zone and a probability of transitioning into phase La Nina much higher than last month for this fall. While until now the risk of a phase transition La Nina for this fall was less than a maintenance in neutral phase, it is now the reverse. It is nevertheless necessary to relativize since we speak of a phase La Nina rather weak between -0.5 ° and -1 °.
With regard to the water temperature anomalies in the major development zone, the situation is not as critical as one might fear, in particular thanks to the almost uninterrupted presence of sand mist above the sea. ocean for 2 months. The latter quite blocks the solar radiation on 2/3 East of the zone and maintains temperatures close to the average in this zone. However we note that the temperatures are in generalized positive anomalies approaching the arc… and I don't really like that.
But this specific pattern (associated with the always strong presence of dry air and sand) could MAYBE allow the West Indies to be a little more spared than other areas (US, Gulf of Mexico and Caribbean) even if it remains very uncertain.
Finally, the start of the season has been extremely active with 9 named systems and these 2 months are placed in 2nd place of the first 2 most active months since 1950. Obviously, the activity of these 2 months greatly influenced the forecast for the rest of the season, even if statistically there is no systematic correlation between the activity of the first 2 months and that of the 4 others.
Conclusion
This update to the 2020 hurricane forecast for August significantly changes the trend of the season. From a forecast of a moderately active season, we go to a forecast of an extremely active season, and that's anything but trivial. Another element questions me a little, it is the significant increase in the number of hurricanes forecast. We go from 9 to 12, that is to say almost 35% more ... and there either, it is clearly not trivial (especially since we even went from 8 to 12, that is to say 50% of increase between June and August) but this is quite logical considering the water temperature off the US and Bahamas and over the Caribbean Sea and the Gulf of Mexico.
I tend to think, given the conditions for the coming weeks, that it will still be better to be on the West Indies than elsewhere in the Atlantic basin. The sand and the water temperatures contained in the MDR are more favorable to it. For the time being !
Let us not forget, however:
- These forecasts are uncertain like all atmospheric forecasts.
- These forecasts are global, which makes anticipation impossible for a territory.
Consequently, whatever the forecast, we must prepare each season in the same way, as if our territory was going to be impacted. This is the only way to be as resilient as possible.
