Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.
By: Dr. Jeff Masters , 2:29 PM GMT on September 04, 2007
A strengthening Hurricane Felix powered ashore as a Category 5 hurricane near the Nicaragua/Honduras border at 8am EDT this morning, bringing 160 mph winds and an 18-foot storm surge to this sparsely populated region. Felix weakened for a period yesterday as it became too tightly would to maintain its eyewall, but a new eyewall formed last night in time for Felix to regain Category 5 strength before landfall. This year marks the first time in recorded history that two Category 5 storms (Felix and Dean) have made landfall in the Atlantic basin in the same year. Since reliable record keeping began in 1944, there have been 27 Category 5 hurricanes in the Atlantic. Eight of these have occurred in the past five years.
Figure 1. Moonrise over the eyewall of Hurricane Felix as it intensified into a Category 5 hurricane Sunday night. Wunderblogger Randy Bynon has more great photos in his blog where he recounts his mission into Hurricane Felix. He was scheduled to fly again today, so he may have more photos tonight of Felix inside the eye as it made landfall in Nicaragua.
Central America will be hard-hit by Felix
Felix's rains will cause serious flooding and dangerous mudslides in Central America all along its path. But, it could have been much worse. Felix came ashore in a sparsely populated area, and damage from the storm's extreme winds and storm surge will mostly affect empty marshlands. As seen in the wind analysis of Felix at landfall (Figure 2), hurricane force winds are confined to a very small region near the center, and it is doubtful that any major cities will experience even Category 1 hurricane winds. Puerto Cabezas, Nicaragua, just 10 miles south of where the eye hit, is still reporting, and has thus far reported sustained winds of 50 mph.
The big worry is the rains from Felix. So far, satellite loops are showing that Felix has not yet tapped into the Pacific Ocean as a source of moisture. Both Hurricane Fifi of 1974 and Hurricane Mitch of 1998 were large and slow moving enough that they were able to draw in large quantities of warm, moist air from the Pacific over the mountains of Honduras. Felix just has Atlantic Ocean moisture to feed its rains, and this should prevent the storm from causing the kind of flooding catastrophe Fifi and Mitch did. With the eye of Felix over land and the storm weakening, I don't believe the storm will be able to match the 20+ inch rainfall totals of those storms. Even so, the 5-10 inches of rain predicted by NHC will cause severe flooding and dangerous landslides throughout Honduras and portions of Nicaragua, Guatemala, Belize, El Salvador, and Mexico. For the next 24 hours, this flooding will be confined to eastern Honduras and northern Nicaragua (Figure 3).
Figure 2. Felix's winds at landfall, as estimated by NOAA's Hurricane Research Division. Areas in yellow are Category 1 hurricane force (65 knots, 74 mph).
Figure 3. Total estimated rainfall for the 24 hours ending at 5am Wednesday, September 5. Image credit: NOAA.
East coast of the U.S. at risk from new tropical disturbance
An area of disturbed weather formed off the north coast of Florida yesterday, and this disturbance has been designated 99L by NHC. Strong upper level winds from the west are creating about 20 knots of wind shear over 99L, and satellite loops show that these winds are keeping all of 99L's heavy thunderstorm activity pushed over to the southeast quadrant of the storm. This shear is forecast to remain between 15 and 25 knots over the next five days by the GFS model, so any development of 99L should be slow. Despite the relatively high shear, the computer models are mostly calling for 99L to develop. Steering currents are weak in the region, and the models agree that 99L is likely to make a clockwise loop over the next three days, then potentially threaten (take your pick):
UKMET: North Carolina on Saturday
NOGAPS: Florida on Friday
HWRF: New York on Saturday
ECMWF: South Carolina on Friday
Canadian: North Carolina on Saturday
The Hurricane Hunters are scheduled to investigate this system at 4pm EDT Wednesday.
The tropical wave in the mid-Atlantic, halfway between Africa and the Lesser Antilles (98L), couldn't hold together its circulation any longer in the face of four days of wind shear and dry air. The disturbance has degenerated into a loose swirl of disorganized clouds. There is still some rotation evident on satellite imagery, and this region will need to be watched over the next few days.
Henriette closes in on Baja
Hurricane Henriette finally took advantage of the favorable environment for intensification it has been in, and developed enough of an eye to be labeled a hurricane. Los Cabos radar and satellite loops show the eye clearly, and some additional organization appears to be going on. An Air Force Hurricane Hunter aircraft is scheduled to provide more information this afternoon, before Henriette comes ashore on the southern tip of the Baja Peninsula tonight. Henriette may have time to intensify to Category 2 status before making landfall in Baja, and again before making a second landfall along the Gulf of California coast in Mainland Mexico. Henriette killed one person due to high surf in Cabo San Lucas yesterday, and six people in landslides in Acapulco Saturday. The remains of Henriette could bring heavy rains to Arizona, New Mexico, and western Texas late this week.
Links to watch for Henriette
Los Cabos radar
San Jose Del Cabo observations
My next update will be Wednesday morning.
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