Weather which affects hurricanes
Learn everything there is to know about Hurricanes
Sea Surface Temperature
One of the key elements of the creation of a tropical storm is the Sea Surface Temperature. In order for the formation of a tropical storm the sea surface temperature needs to be above 80F (27C). Higher sea surface temperatures fuel larger storms. Once storms reach the northern latitudes where the sea surface temperature is below 80F (27C) they weaken and die.
Bermuda Azores High
The Bermuda Azores High is not responsible for hurricanes or tropical storm formation. However it can be a factor in where storms go. This is due to the fact that winds around the high pressure area storms move around a High in a clock wise rotation. Therefore, if the Bermuda Azores High is over Bermuda, storms pass to our west or up the Atlantic coast of the USA. If the High is to our east storm can track over Bermuda.
The ability of predicting the seasonal location of the Bermuda High is beyond current scientific knowledge.
El Niño (Spanish for a male child), originally referred to a weak, warm current appearing annually around Christmas time along the coast of Ecuador and Peru and lasting only a few weeks to a month or so. Every three to seven years, an El Niño event may last for many months, having significant economic and atmospheric consequences worldwide.
Periods of El Nino have a benign effect on the Atlantic hurricane season as a result of a stronger jet stream. A stronger Jet Stream increases wind shear thereby inhibiting the growth of hurricanes, particularly Cape Verde storms.
La Nina Spanish for a little girl is a period of strong trade winds and unusually low sea surface temperatures in the central and east equatorial Pacific.
An intense La Nina is accompanied by weather extremes that are usually opposite those of an El Nino. Upper winds in the Atlantic are not as strong so there is less wind shear resulting in more storm activity. Therefore hurricane activity in the Atlantic and Caribbean increases substantially during a La Nina period.
The Jet Stream has been described as a `river of air five to seven miles above the earth`. It can be affected by both El Ninos and La Ninas.
El Niño causes higher amounts of heat and moisture to be released into the atmosphere. This creates a difference in the amount of heat found at the equator as opposed to higher latitudes. This heat difference allows the jet stream to be stronger and faster thus promoting wind shear.
La Niña causes smaller temperature differences between the equator and high latitudes and results in the average position of the jet stream being much further north. This allows the Bermuda High to move closer to Bermuda and the east coast.