Average 20 year old weather nerd. Plymouth State University Meteorology, Class of 2018. NOAA Hollings scholar. Summer 2016 intern at NWS Boston.
By: MAweatherboy1, 5:11 PM GMT on May 14, 2016
Welcome to my May update for the 2016 hurricane season forecast. My original forecast was issued back in March, and called for (including January’s Hurricane Alex) 11 storms, 6 hurricanes, and 2 major hurricanes, with accumulated cyclone energy (ACE) 75-90% of normal. This issuance is meant as an update of that post. This will serve as my final extensive preseason update and numbers forecast, although I may write blogs on individual storms or the state of the season as we go through the summer. All the disclaimers from the original post still apply- these are my thoughts alone.
By and large, I remain happy with my original forecast. In particular, taking a look at ENSO conditions in the Pacific, the expected significant cooling of the anomalies in the ENSO regions are indeed well underway. Cold sub-surface water has started propelling its way to the surface, and confidence has increased that a La Nina is on the way. A “cold tongue” of surface waters is now observed at the equator in the Pacific. This hurricane season will likely take place in primarily cool neutral to weak La Nina conditions, with the trend being for cooler ENSO with time. Lingering effects of El Nino may have some impact in June as there tends to be a lag period between what happens with the oceans and how the atmosphere reacts.
The Atlantic SST anomaly map also looks quite similar to how it did when my original post was made, and I generally stand by my original thoughts on that topic. While we see occasional periods of warming and cooling of certain regions, the overall state of the basin remains the same. The AMO remains in close to a neutral state, although it's tried to go a bit more positive of late, with cold water in the North Atlantic characteristic of a cold AMO, but warmer than normal water in the main development region in the tropics. The Caribbean and Gulf of Mexico SSTs remain mostly above normal, although the Gulf has anomalously cooled some of late.
The emerging La Nina and generally near to above normal SSTs in the tropics argue for a more active than normal season. We’ve seen several forecasts issued by sources like Colorado State University, Accuweather, and The Weather Channel in the past month or two, generally calling for near to slightly above normal activity.
My original forecast was for slightly below normal activity, due to some limiting factors which I pointed out in that post. I still see most of those limiting factors. My concerns about the Atlantic SST configuration remain; while for the moment the basin looks more favorable, I'm not sure that this will hold up. The strong cold pool in the far North Atlantic remains, which is a common negative AMO feature. Most other parts of the basin are near to above average for SSTs, including the MDR, but the expansive warm anomalies in the mid-latitudes are not necessarily a benefit for developing lower latitude hurricanes. Vertical instability in the Atlantic continues to be significantly below normal as well, with no signs of that changing.
Still, this season is not without its positives for hurricane activity. I am increasingly concerned about the potential for storm activity in the Caribbean and Gulf of Mexico, especially deeper into the season. SSTs in those regions are solidly above average, and unlike in recent years, wind shear in the middle and latter part of the season should generally be near to below normal in those regions due to La Nina. With La Nina strengthening deeper into the season, I strongly suspect the odds for a late season hurricane in the Caribbean are increased. I think it could be a struggle to get hurricanes developing east of the Caribbean due to instability issues, but on the whole the basin should be less hostile than in previous years.
I have apprehensions about going for too high of a number given what we've seen the past few years. However, it makes little sense to me to go with a forecast of near as much or less activity than last season, when despite a raging El Nino and a less favorable Atlantic the basin still managed 11 storms. With all of this said, my forecast for seasonal activity will be increased a little from my initial forecast. Including Alex, my final numbers are:
*13 named storms
*2 major hurricanes
*ACE 90% of normal
In summary, I continue to expect a season above the long term average but a little below the average since the warm AMO era began in 1995. However, I think it is likely that US and Caribbean impacts will be near to above average. I also continue to feel that this remains a more uncertain than normal seasonal forecast. My confidence is higher than it was at my first forecast issuance, but there are still a lot of variables in play, and only time will tell how it will all play out. As always, preparation is key, and no matter the seasonal forecast, it only takes one high impact storm to change everything, so have a plan in place if you live in a hurricane prone area.
Thank you as always for reading. I’m looking forward to another great season of storm tracking. See you on the blogs!
The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.