Although El Nino is looking likely to be in place for at least the first part of the upcoming season, I'm not expecting the Atlantic to be "shut down" by any means. El Nino may usually increase the wind shear in the western MDR and the Caribbean Sea, but it doesn't have as much of an effect on the rest of the basin.
FACTORS ENHANCING DEVELOPMENT
1. Expected Strong West African Monsoon - This is the #1 reason why I'm not expecting a very quiet year (i.e., a year with ACE <50). If the MDR warms more relative to average during the early part of the season, I wouldn't be too surprised if we see a tropical wave or two develop over the far eastern Atlantic, strengthen quickly, and either recurve or fall apart east of the Lesser Antilles. Sahel precipitable water has been well above average so far, as noted in the tweet above. This likely is a signal for a strong African Monsoon, which would not only enhance the "wave train" but also possibly result in some additional MDR warming by the peak of the season.
2. A likely favorable subtropics - The warm subtropics in recent years have made this region more favorable for tropical and subtropical development. Last year we saw a record number of subtropical storms. While many dismiss these systems as "junk storms" or "boring" they are fascinating to look at, and in some cases, they transition into bonafide hurricanes. Look at Joaquin in 2015, an El Nino year - it developed from an upper-level low and nearly reached Category 5 strength.
3. A warmer MDR than last year - It's looking likely, based on current MDR SSTAs and the model guidance, that the Atlantic Main Development Region will likely be warmer than normal at peak, which is contrast from last season when it was cooler than normal. If this is true, this would enhance the convective potential in the region, and we would likely see the MDR get going a little earlier than last season when it was dead, aside from Beryl, until the very end of August.
Look back at 2015. This El Nino is highly unlikely to even come close to the strength of that event, and that season was only slightly below average. It wouldn't surprise me to reach an ACE total of 80-90 if a moderate El Nino is present.
NCSU meteorology student and weather blogger at www.cyclonicfury.com
. My forecasts and thoughts are NOT official, for official forecasts please consult the National Hurricane Center.