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Richard hits Belize, weakens to a tropical storm

By: Dr. Jeff Masters, 12:38 PM GMT on October 25, 2010

Hurricane Richard hit central Belize last night at approximately 8:45pm EDT as a Category 1 hurricane with 90 mph winds. The hurricane made landfall about 20 miles south of Belize's largest city, Belize City (population approximately 100,000--1/3 of Belize's population.) Richard's northern eyewall passed just south of the airport, which measured top winds of 37 mph, gusting to 62mph, at 8pm CST. The airport picked up 3.66" of rain. Richard was a small hurricane, and hurricane-force winds affected a region of coast of no more than 20 - 30 miles wide, just to the south of Belize City. As Richard made landfall, the eye grew tighter and more defined, subjecting a smaller portion of the country to the extreme winds of the eyewall. This contraction of the eye was probably caused by frictional convergence--as the winds spiraling into the center of Richard passed from ocean to land, the increased friction caused the winds to slow down as they reached the eyewall. This made the inflowing air pile up near the eyewall, and this piled-up air was forced upwards into more violent updrafts, intensifying the thunderstorms in the eyewall and causing eye to contract. This intensification lasted only an hour or two, before the inland motion of the center removed Richard from its main energy source, the warm waters of the Western Caribbean.

Figure 1. Visible MODIS satellite image of Hurricane Richard taken at 12:45pm EDT 10/24/10 by NASA's Aqua satellite. A the time, Richard was a Category 1 hurricane with 85 mph winds. Image credit: NASA.

The top winds measured at any station in Belize occurred at a personal weather station on the offshore island of Caya Caulker, which had sustained winds of 54 mph yesterday afternoon at 3:55pm CST local time. Despite the relatively small portion of Belize that was subjected to strong winds from Richard, the storm was able to knock out power to the entire nation for a period of many hours. There are no reports of deaths or injuries, but preliminary media reports indicate major wind and flooding damage in regions near where the center came ashore.

Richard was a hurricane for 18 hours, and was the 10th hurricane of the 2010 Atlantic hurricane season. This year's ten hurricanes ties it for sixth place for most hurricanes in an Atlantic hurricane season. Our seventeen named storms this year also ranks as the 6th most in history. Atlantic hurricane season records go back to 1851.

Figure 2. Zoom radar image of Hurricane Richard at landfall, 8:53pm EDT 10/24/10. Belize City was just north of the northern eyewall, and did not receive tropical storm force winds, according to the hourly observations taken at the airport. However, Belmopan, the capital of Belize, experienced the northern eyewall of Richard. Image credit: Belize Meteorological Service.

Forecast for Richard
Richard has weakened to a tropical storm with 45 mph winds, as it moves west-northwest over the Yucatan Peninsula. Richard's small size and relatively slow forward speed of 5 - 10 mph will lead to continued weakening today as it crosses the Yucatan Peninsula. The storm will probably be a tropical depression when it emerges over the Gulf of Mexico on Tuesday--if it survives the crossing. If Richard does survive the crossing, moderate wind shear and dry air over the southern Gulf of Mexico should keep the storm from intensifying. Richard should dissipate by Wednesday, before affecting any other land areas.

Invest 90L
A low pressure system (Invest 90L) centered near 23N 42W in the middle Atlantic Ocean, has developed a broad circulation. A band of heavy thunderstorms has developed in an arc to the north and east of the storm, well removed from the center, suggesting that 90L is a hybrid subtropical system. Wind shear is a high 20 - 25 knots, but is predicted to drop to the moderate range, 10 - 20 knots, this afternoon through Wednesday. This may give 90L the opportunity to develop, though water temperatures are marginal for development, just 26.5 - 27°C (26.5°C is usually the limiting SST that a tropical storm can develop at.) The NOGAPS model is calling for 90L to develop into a depression by Friday, when the storm will be near Bermuda. NHC is giving 90L a 10% of developing into a tropical depression by Wednesday.

Next update
I'll have an update on Tuesday. I'm not sure when that update will be, as I am catching a flight to Miami in the morning. I've been invited to spend the week at the National Hurricane Center as part of their visiting scientist program, and will be shadowing NHC forecasters on the evening shift Tuesday - Friday to learn more about their operations. I'll be writing a post later this week about what a shift is like at the Hurricane Center. I also have meetings planned with scientists at NOAA's Hurricane Research Division, and plan to write about some of the research missions performed during this year's hurricane season.

Our weather extremes expert Christopher C. Burt has a very interesting post today on the hottest temperatures ever measured on Earth.

Jeff Masters


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