About Jeff Masters
Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters from 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather
By: Dr. Jeff Masters , 9:34 PM GMT on October 17, 2005
Wilma is steadily intensifying. The hurricane hunters reached the storm at 4:05 pm EDT, finding maximum surface winds of 50 mph and a central pressure of 989 mb. Satellite imagery shows that deep convection is starting to wrap all the way around the center, and infrared imagery hints at a warm center spot where an eye may form by Tuesday. The hurricane hunters noted that spiral banding looked good, and satellite imagery also shows an impressive amount of spiral banding developing on all sides. The dry air intruding on the northwest side is starting to mix out, and upper-level outflow is well established on the south and east sides of the storm.
The upper level environment continues to look favorable for intensification, with low wind shear and an anti-cyclone on top generating good outflow. Intensification into a Category 3 hurricane by Thursday still seems like a good bet. Once Wilma gets further north into the Gulf of Mexico, shear increases as a upper-level trough of low pressure generates strong westerly winds over Wilma. This shear will likely reduce Wilma's winds by at least 20 mph.
Figure 1. Track of 1974's Hurricane Fifi, which killed over 8000 people in Honduras.
Steering currents are expected to remain weak the next two days, and some erratic motion is possible. All of the forecast models predict a generally west or west-northwest motion over the next two days. However, today's southerly motion at 2 - 5 mph is something none of the forecast models called for, except the UKMET model. This gives me some concern that Wilma may pass close enough to Honduras to create heavy downpours of 10 - 15 inches that would cause severe flooding and significant mudslides. It doesn't take a very strong hurricane to kill thousands in Honduras, as 1974's Category 2 Hurricane Fifi demonstrated. Hurricane Fifi moved along the north of the coast of Honduras at about latitude 16.1, bringing heavy rains of up to 24 inches that killed 8000 people. Wilma is currently at latitude 15.9, and looks like it will also be a Category 2 hurricane as it passes along the north shore of Honduras. Heavy rains will begin in northeastern Honduras tonight, and may well continue for three days. Hopefully, Wilma will pull north as forecast and not subject the entire coast of Honduras to flooding rains as Fifi did. I do expect severe flooding in northeast Honduras that will cause heavy loss of life. Better disaster prevention measures were implemented in Honduras after the devastation Hurricane Mitch wrought in 1998, so hopefully the government will be able to get the people in flood-prone areas to safe shelter and reduce the death toll.
Wilma presents it's next greatest threat to Mexico, which is still cleaning up the damage from Hurricane Emily earlier this year. Heavy rains in Belize, Nicaragua, and northern Guatemala may also create flooding problems in those nations. If Wilma grows large enough to tap the Pacific as a source of moisture, El Salvador and the southern portions of Guatemala hard-hit by Hurricane Stan may get addtional rains that could be a problem. However, the computer models are not indicating that this will happen.
The models have reached more of a consensus this afternoon on the longer term track of Wilma. After struggling mightily to properly resolve a weak trough of low pressure over the central U.S., the models now agree that this trough should be able to pull Wilma west-northwest by Tuesday. Later in the week, a strong low pressure system currently bringing rain to southern California is expected to move east and exert a strong pull on Wilma, turning her more northwest by Thursday. After Wilma makes a landfall near Cancun/Cozumel or a passage through the Yucatan Channel, the trough is expected to pull her northeastward, resulting in a landfall on the west coast of Florida somewhere between Key West and Tampa. The timing and location of the U.S. landfall forecasts look like this:
Candian model: Friday, Sarasota
GFS model: Saturday, Florida Keys
NOGAPS model: Saturday, Florida Keys
GFDL model: Sunday, Tampa
UKMET model: Wilma stalls out over the Yucatan at day 6; eventual track after that not known.
The NOAA jet is scheduled to make its first flight Tuesday afternoon, and we'll have a much better idea of the likely U.S. landfall point on Wednesday morning.
Elsewhere in the tropics, nothing else is happening. I'll be back with a update in the morning about 10 am EDT.
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