Wednesday, August 3, 2016

Hurricane Warnings in Belize, Honduras, and Mexico for Earl

By: Jeff Masters , 3:29PM,GMT on August 3,2016



 
Hurricane warnings are flying for the coast of Belize, the southern portion of Mexico's Yucatan Peninsula, and the islands off the north coast of Honduras, as a strengthening Tropical Storm Earl speeds westwards at 14 mph. The Hurricane Hunters did not find hurricane-force winds in Earl in a mission that departed from the storm around 8 am EDT Wednesday, but a new airplane arrived in Earl around 11 am, and will likely find that Earl is a hurricane by mid-afternoon Wednesday. Satellite loops on Wednesday morning showed Earl was steadily gaining in organization, with an increase in symmetry, low-level spiral bands and heavy thunderstorm activity. No eye was apparent in the visible satellite imagery, but we should see one appear before sunset on Wednesday. The outer bands of Earl were just beginning to appear on Belize radar late Wednesday morning.


Figure 1. Tropical Storm Earl as seen at 3:30 pm EDT August 3, 2016, when the storm had top sustained winds of 70 mph. Image credit: NHC Facebook page.

Forecast for Earl
The forecast for Earl appears straightforward. Earl is trapped to the south of a strong area of high pressure that will keep the storm moving on a track slightly north of due west at 10 - 14 mph over the next four days. This motion will bring the center of the storm within twenty miles of Guanaja Island off the coast of Honduras near 4 pm EDT Wednesday, then to the coast of central Belize around 4 am EDT Thursday. Earl has favorable atmospheric and oceanic conditions for intensification: light to moderate wind shear of 5 - 15 knots, and very warm ocean waters near 30°C (86°F). These warm waters extend to great depth, providing plenty of fuel to power intensification of the storm. Typically, storms that approach landfall begin to undergo interaction with land that causes a slowdown in intensification or weakening. However, storms in the Western Caribbean often undergo intensification right up until landfall, due to the extremely warm waters with high heat content that lie along the coast. The topography of the coast in the right-angle bend between Belize, Guatemala, and Honduras may also act to aid intensification by giving storms more spin, as air gets deflected into a counter-clockwise motion by the high terrain ringing the ocean. This effect has been shown to exist in modeling studies of some storms in the Gulf of Mexico's Bay of Campeche, but has not been studied (to my knowledge) for the region along the coasts of Honduras, Guatemala, and Belize, though.

The main concern from Earl is its heavy rains. With rainfall amounts in excess of 8" expected over a swath of northern Honduras, northern Guatemala, most of Belize, and a chunk of Mexico, expect life-threatening flash floods and landslides. The storm's 4 - 6' storm surge will cause additional flooding along the coast near and to the right of where the center hits in Belize. Strong winds will also be a major concern. In their 11 am EDT Wednesday Wind Probability forecast, NHC gave Guanaja Island a 97% and 30% chance of experiencing tropical storm-force winds of 39+ mph and hurricane-force winds of 74+ mph, respectively. For Belize City, these odds were 94% and 17%, respectively. Earl is already a killer: high winds in the Dominican Republic associated with the tropical wave that became Earl brought power lines down and sparked a fire aboard a bus, killing 6 and injuring 12 people, according to weather.com. Three others were killed after a tour boat overturned, although that incident had not yet been confirmed to be weather-related.


Figure 2. Tracks of the approximately 80 tropical depressions, tropical storms, and hurricanes that have hit Belize since 1851. Image credit: NOAA/CSC.

Belize hurricane history
Belize is often struck by tropical storms and hurricanes. Approximately 80 tropical depressions, tropical storms, and hurricanes have hit Belize since 1851, but it has been five years since the last landfall by a named storm--Tropical Storm Harvey, which hit on August 20, 2011, with 65 mph sustained winds. Harvey's flooding rains killed five people in Mexico, but did little damage in Belize. The last hurricane to hit Belize was Hurricane Richard on October 23, 2010, which made landfall about 20 miles south of Belize's largest city, Belize City (population approximately 100,000--1/3 of Belize's population.) Richard hit as a Category 2 hurricane with 100 mph winds, but was a small hurricane, with hurricane-force winds affecting a region of coast of no more than 20 - 30 miles wide. The hurricane killed one and did about $80 million in damage. The last major hurricane to hit Belize was Hurricane Iris on October 9, 2001, which made landfall in southern Belize as a Category 4 storm with 145 mph winds, killing 35 and doing $250 million in damage.

Links for Earl
Belize radar
National Emergency Management Organization of Belize

Webcam links posted by WU members in the comments:
Belize webcams
Ambergris Caye, Belize
Roatan, Honduras

Elsewhere in the Atlantic
There are no other tropical cyclone threat areas in the Atlantic to discuss today, and none of the reliable models for tropical cyclone formation is predicting development during the coming five days. Despite the relative lack of dry air and dust from the Sahara Desert over the tropical Atlantic, the strong tropical wave near 9°N, 38°W, midway between Africa and the Lesser Antilles, is showing no signs of development, and the 50 members of the European model ensemble and 20 members of the GFS model ensemble are giving little support to development of this wave over the coming week.

A few recent runs of the European model have shown that a weak trough of low pressure will move over the Southeast U.S. early next week and move over the northeast Gulf of Mexico, off the Florida Panhandle coast. About 10% of the 50 members of the European model ensemble forecast have been highlighting this area for possible formation of a tropical depression in 5 - 7 days.

Howard and Ivette active in the Eastern Pacific
The Eastern Pacific continues to be active, with two named storms, Howard and Ivette. Neither storm is a threat to land. Tropical Storm Howard hit its peak with 60 mph winds on Tuesday, and is steadily deteriorating as it runs into cooler waters and a more stable atmosphere. Howard should be a remnant low by Thursday night, but could bring some squally weather and high surf to portions of Hawaii on Sunday. Next up is Tropical Storm Ivette, which is gathering strength in the Pacific waters south of the Mexican coast. Ivette will be moving away from the Mexican coast on a west to west-northwest track, and is expected to peak as a Category 1 hurricane on Saturday before cooler waters and less favorable atmospheric conditions result in weakening as the storm approaches Hawaii early next week.

There is one more area of concern in the Eastern Pacific: the possible arrival of the remnants of Hurricane Earl early next week. Earl will cease to exist as a named storm during its long traverse of Mexico during the coming weekend, but if Earl's remnants manage to cross over Mexico and arrive over the waters off the coast of Acapulco, Mexico with some spin still intact, regeneration into a tropical storm is possible. In their 8 am EDT Wednesday Eastern Pacific Tropical Weather Outlook, NHC gave the remnants of Earl 2-day and 5-day development odds of 0% and 30%, respectively. If Earl's circulation has become unidentifiable the time it crosses into the Pacific, the new storm would be named Javier.

Jeff Masters

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