Thursday, May 22, 2014

Professor Quibb's Picks - 2014

My personal predictions for the 2014 Atlantic hurricane season are (written May 22, 2014)

13 cyclones attaining tropical depression status,
12 cyclones attaining tropical storm status,
4 cyclones attaining hurricane status, and
1 cyclone attaining major hurricane status.

These predictions are near normal for the tropical depression and tropical storm categories, and below normal for the hurricane and major hurricane categories. The last 15 years have for the most part seen exceptionally high tropical cyclone activity due to the "warm" phase of the Altantic Multi-Decadal Oscillation (AMO). This oscillation (involving anomalies in sea surface temperatures) could explain the high tropical cyclone activity in the 1950's, the low activity in the 1980's, and the high activity in the 2000's. The current warm phase is expected to last at least several more years, likely keeping the number of tropical cyclones close to average even during seasons in which conditions are not generally favorable, such as this coming season.

ENSO oscillation forecasts indicate that an El Nino is likely to develop during the 2014 hurricane season, particularly in the late summer. Since an El Nino event is associated with a strong jet stream across the U.S. and higher wind shear, the development of such an event is likely to supress hurricane activity. Since the event is predicted to develop near the peak of the season, hurricanes and major hurricanes (which form more often near the peak of the season) are less likely.

In a manner similar to last season, the ocean temperatures of the east Atlantic are predicted to be below average for much of this season. This too discourages the formation of major hurricanes, since powerful tropical cyclones most often have their origins in the east Atlantic. During August 2013, a large quantity of Saharan dust was blown westward over the eastern Atlantic, cooling the water and disrupting cyclone formation. Though such events are difficult to forecast, above average trade winds could result in a similar event this season, further reducing eastern Atlantic activity.

Below, my anticipated risk factors for four major regions of the Atlantic basin are listed. The risk index runs from 1 meaning very low potential to 5 being very high potential (with 3 about average).

U.S. East Coast: 3
Though the season as a whole is expected to be inactive, any cyclones which do develop are likely to curve northward due to the position of the Bermuda high pressure system farther to the east during an El Nino. Thus the possibility exists for a grazing blow to coastal areas, especially Cape Hattaras.

U.S. Gulf Coast/Northern Mexico: 2
The Gulf of Mexico (particularly its northwestern section) have recorded persistently low sea surface temperature this year compared to the rest of the Atlantic basin. This factor, combined with the strong upper-level winds and powerful frontal boundaries passing over the U.S. Gulf coast, will likely destroy cyclones approaching the region.

Yucatan Peninsula and Central America: 2
This season, the upper atmospheric conditions favor cyclones paths which curve to the north, due to the eastward position of the Bermuda High pressure region. Usually, cyclones must take a more westward track without curavture in order to affect Central American regions and the Yucatan Peninsula. Any tropical systems reaching land therefore are likely to be weak tropical storms. In fact, this region is more at risk from Eastern Pacific tropical cylones than Atlantic ones.

Caribbean Islands: 2
During an El Nino season, Caribbean summers tend to be dry, due to a dry air mass situated over much of the region. In addition, persistent wind shear also pervades the Caribbean during an El Nino. The combination of these two factors can halt tropical cyclone development for weeks on end, ensuring that any storms that do develop pass to the north. The largest risk to the Caribbean Islands is for a cyclone to pass just to the north.

Overall, the 2014 Atlantic Hurricane Season is expected to be below average, particularly in intense cyclones, and the risk to most landmasses is smaller than normal. However, as history has repeatedly demonstrated, even quiet seasons may have devastating storms, such as Hurricane Andrew of 1992. Only 7 tropical storms formed that year, but one, Andrew, made landfall in Florida as a category 5 hurricane, only the third Atlantic hurricane to make landfall at such an intensity in recorded history. During any season, hurricane preparedness is a must.

Wednesday, May 14, 2014

Hurricane Names List – 2014

For the North Atlantic Basin, the list for naming tropical cyclones in 2014 is as follows:

Arthur (used)
Bertha (used)
Cristobal (used)
Dolly (used)
Edouard (used)
Fay (used)
Gonzalo (used)
Hanna (used)

This list is the same as the 2008 list with the exception of Gonzalo, Isaias, and Paulette, which replaced Gustav, Ike, and Paloma, respectively. These names were retired after the 2008 season.