Hurricane Alvin is first storm of 2019 Eastern Pacific Hurricane Season (Photo Credit: National Hurricane Center)
DISCUSSION: On June 25, the National Hurricane Center (NHC) issued the first advisory of the 2019 Eastern Pacific Hurricane season when an area of low pressure and thunderstorms officially strengthened into a Tropical Depression. The Eastern Pacific hurricane season starts on June 1, the same date as the Atlantic Hurricane season also begins. The tropical depression which at the time was called One-E is the first tropical storm of the season in the Pacific Ocean. One-E began as a low-pressure system off the southwestern coast of Mexico when the NHC first took notice of it on June 19. One-E began to move out toward open ocean westward and on the 25th developed a defined center of circulation with sustained winds at 30 nautical miles per hour (knots) or 35 miles per hour.
One-E officially became Alvin as it strengthened into a Tropical Storm on the 26th at the sustained windspeed of 35 knots. Alvin, according to the NHC, is the third latest date of the development of the first storm in the Pacific Ocean basin since 1966. Alvin made a westerly track as it increased in intensity with maximum sustained winds at about 55 knots. Alvin was the strongest during the afternoon of the 27th before weakening gradually as it moved westward into some of the more colder waters of the Pacific and was not be able to sustain energy for development and dissipate. Tropical storms generally weaken if the sea-surface temperature is at 80 degrees Fahrenheit or below, as there is less energy available for usage as temperature decreases. 80 degrees Fahrenheit is vital for tropical cyclogenesis (the creation and evolution of tropical cyclones) as warmer water is able to evaporate quickly and the water vapor rises up and cools down which releases the latent heat (the heat needed to convert liquid to gas or vapor) which is the main engine of the storm as it condenses. In addition, 80 degrees Fahrenheit is vital for this process as deep convection is not as possible at lower temperatures which is vital as deep convection is when the temperature of an imaginary parcel of air is warmer than the surrounding up to and above 500 millibars. Deep convection is usually affiliated especially with tropical cyclones due to the fact that the amount of energy that is released and absorbed in the storms is crucial in the thunderstorms and evaporation needed to sustain the cyclone.
Alvin officially became dissipated on the morning of 29th as it became a remnant low. A remnant low is a low pressure system which involves the remains of the tropical storms and hurricanes. Alvin was never a concern to hit land due to the westward track it was taking. However, we at the Global Weather and Climate Center would like to remind you to be prepared this hurricane season by listening to warnings issued by the National Weather Service as well as to have emergency food and water for about fourteen days, blankets, batteries, flashlights, sandbags and boards for windows ready if a hurricane or tropical storm is expected to hit your area and you cannot evacuate.
To learn more about tropical cyclones click here!
©2019 Meteorologist JP Kalb