A spate of early season tropical activity due to conducive atmospheric conditions and a floundering El Nino has spurred NOAA to increase their odds for a busy hurricane season in the Atlantic as the peak interval approaches.
Before we examine the updated forecast let’s take a quick look at Franklin and Invest 99L.
5-day graphical outlook from the NHC:
Franklin is increasing in organization as it moves across the southern Gulf and is currently expected to achieve category 1 intensity prior to making landfall in Mexico tonight.
Visible satellite view of TS Franklin:
99L’s fate remains clouded in uncertainty but the pattern still favours a recurving path off the Eastern seaboard as a trough swings in on approach. The possibility of a track SE of Atlantic Canada seems reasonable for now but things remain hazy in terms of specifics.
Visible satellite view of 99L:
The third disturbance highlighted in the graphical outlook has limited potential to develop but may bring heavy rainfall to Florida and the Bahamas over the course of the short range.
Chances for an above-average Atlantic hurricane season have been boosted according to NOAA in their latest update today. They cite a combination of contributory factors which include the wavering odds of El Nino making his move and warm SST’s which we’ve discussed at some length dating back to the spring months.
New 2017 seasonal outlook via NOAA:
List of tropical cyclone names for the season:
A synopsis of their reasoning:
Forecasters are now predicting a higher likelihood of an above-normal season, and they increased the predicted number of named storms and major hurricanes. The season has the potential to be extremely active, and could be the most active since 2010.
Forecasters now say there is a 60-percent chance of an above-normal season (compared to the May prediction of 45 percent chance), with 14-19 named storms (increased from the May predicted range of 11-17) and 2-5 major hurricanes (increased from the May predicted range of 2-4). A prediction for 5-9 hurricanes remains unchanged from the intial May outlook.
In just the first nine weeks of this season there have been six named storms, which is half the number of storms during an average six-month season and double the number of storms that would typically form by early August. An average Atlantic hurricane season, which runs from June 1-November 30, produces 12 named storms, of which six become hurricanes, including three major hurricanes.
Today’s update also decreases the chance of a near-normal season from 35 percent to 30 percent, and a below-normal season from 20 percent to only 10 percent from the initial outlook issued in May.
SST anomalies as of August 8th:
Tropical cyclone heat potential: