Summary: I am forecasting a slightly below average tropical and hurricane season due to the likelihood that El Nino conditions will take hold during this summer and autumn. That said, above average ocean temperatures over the sub-tropics could lead to quickly developing and quickly strengthening tropical systems in-close to land. This will be something to certainly watch out for.
The Numbers: 12 Named Storms, 6 of those storms becoming Hurricanes and 2 of those hurricanes becoming Major Hurricanes (Category 3 or higher on the Saffir-Simpson scale).
Accumulated Cyclone Energy (ACE) Index Forecast: I am forecasting an ACE index this year of 90, which is below average.
ENSO Conditions: It looks very likely that El Nino conditions will develop by this summer and remain in place through this autumn. The question becomes how strong will the El Nino conditions get. At this point, the ECMWF ENSO forecast is for a moderate to even strong El Nino by late summer. My feeling is that this is too strong of an onset and the European model, in the past, has been too bullish on its El Nino forecast and I think we’re seeing the same here. The CFS model seems to be a little more tame and shows the potential for a weak to moderate El Nino by this autumn.
My thinking is that we should probably see neutral (neither La Nina nor El Nino) ENSO conditions transition into weak El Nino conditions by early summer. A weak to possibly moderate El Nino conditions should persist through the rest of the summer and the autumn.
In terms of the hurricane season, this could lead to a quick start to the hurricane season with development possible as soon as May and June. Beyond this, the oncoming weak to moderate El Nino conditions may put a kibosh on the hurricane season perhaps as early as October this year. Overall though, I do think we’re in for an overall slightly below average hurricane season in terms of numbers.
Sea Surface Temperatures: The lack of any real winter this year has really affected the ocean water temperatures across the western North Atlantic and the Gulf of Mexico with above average temperatures noted. An area of near to below average ocean water temperatures are currently occurring over the central and eastern Caribbean.
One of the keys in determining how active/inactive the hurricane season will be is how much will the deep tropics (south of 25 North Latitude) warms up during April, May and June. The latest climate models seem to suggest that the main area of above average temperatures may be found across the sub-tropics rather than the deep tropics. Should this occur, it would lead to the possibility of the deep tropics being inactive with more activity centered above 20 North Latitude.
Analog Years: These are the analog years that seem to be a close match right now to what the 2023 hurricane season may be like.
They are: 1899, 1918, 1951, 1957, 1965, 1972, 1976, 1997 & 2009.
Landfall Threat Forecast: There are about three areas that I’m most concerned about for this upcoming season in terms of a tropical storm or hurricane impact.
The First Area Is the northern US Gulf Coast and in particular around the Florida Panhandle. Both the analog data and the seasonal guidance such as the NMME, CFS and European seasonal guidance are showing signals that this is going to be a spot to keep an eye on.
The Second Area Of Particular Concern Is a corridor from the northern Bahamas to eastern North Carolina. Analog data points to that tropical storm/hurricane activity could be steered in this direction. It should be noted though that the seasonal guidance show some hints that areas a little further west from the eastern Florida Peninsula through the coastal parts of Georgia and the Carolinas may be an area to watch.
The Third Area Of Concern Is the Yucatan Peninsula where analog data shows that this could be an area to watch for tropical storm/hurricane activity. That said, I do think that a majority of the Caribbean could be quite inactive due to increasing wind shear due to El Nino conditions and an unfavorable sea surface temperature profile.
Even though your area may have a low or medium risk this season, be aware that any small fluctuations in the upper level weather pattern at the “wrong” time could threaten the low or medium risk areas.
Finally, we will begin sending out daily tropical weather discussions for the 2023 Atlantic Hurricane Season on Monday, May 1st.
2023 Atlantic Tropical Cyclone Names:
Arlene
Bret
Cindy
Don
Emily
Franklin
Gert
Harold
Idalia
Jose
Katia
Lee
Margot
Nigel
Ophelia
Philippe
Rina
Sean
Tammy
Vince
Whitney