Paula misses Mexico, stalls in Yucatan Channel

Hurricane Paula is now stationary over the Yucatan Channel, the narrow gap between Mexico's Yucatan Peninsula and the western tip of Cuba. Despite Paula's Category 2 strength and passage just 60 miles east of the Mexican coast, the hurricane has not brought tropical storm-force winds to Mexico. In Cancun, top winds measured so far this morning have been just 17 mph, with gusts to 27 mph. A modest 0.17" of rain fell between midnight and 8:21am local time. Cancun radar (Figure 1) shows that the rain bands in the tightly would core of Paula lie just offshore of Cancun this morning. Paula had little impact on Mexico's Cozumel Island as the storm passed by last night; winds remained below 20 mph during passage.


Figure 1. Radar image at 9am EDT 10/13/10 from Cancun, Mexico. The core of Paula was located 60 miles to the east of Cancun, and Paula's rainbands were remaining just offshore. Image credit: CONAGUA Mexico.

Satellite imagery shows little change to Paula has occurred this morning. The amount and intensity of the storm's heavy thunderstorms have remained about the same as last night, and satellite intensity estimates continue to support calling Paula a hurricane with 90 - 100 mph winds. The Hurricane Hunters left Paula at 4am, and will not be back until 2pm, so we will have to wait until then to get a better estimate of Paula's intensity. At that time, I expect they will find a weaker storm, as wind shear has increased to a high 25 knots, due to strong upper-level winds out of the south. Cancun Radar shows the storm has stalled and been stationary between 6am - 9am EDT; if Paula remains nearly stationary for several more hours, the hurricane may churn up cold water from the depths, causing weakening. However, Paula is currently over a patch of the deepest, warmest water in the entire North Atlantic. Waters of 26°C (79°F) or warmer extend to a depth of 400 feet (120 meters) in the Yucatan Channel, and it will take much longer than usual for a stationary hurricane in this region to significantly cool the surface waters.


Figure 2. Visible satellite image of Paula taken at 12:20pm EDT 10/12/10 by NASA's Terra satellite. Image credit: NASA.

Forecast for Paula
Paula should start moving to the northeast or east later this morning, bringing it near the tip of western Cuba late tonight or early Thursday morning. Hurricane force winds extend out just fifteen miles from Paula's center, so only a very small region of coast will receive Paula's strongest winds if landfall occurs. The 5am EDT wind probability product from NHC gives Cabo San Antonio on the western tip of Cuba the highest odds of receiving hurricane force winds of any land area--a 34% chance. Key West is given a 2% chance, and Havana, Cuba, a 6% chance. It currently appears that heavy rain will be the major threat from Paula. If Paula stalls over or near western Cuba for several days, the hurricane could easily dump more than ten inches over mountainous regions of the island.

The latest SHIPS model forecast calls for wind shear to rise to a very high 30 knots tonight, and remain about 30 knots for the rest of the week. This high shear, caused by strong upper-level winds from the south, should begin to eat away at the south side of Paula's eyewall today, causing the inner core of the storm to collapse and Paula to weaken to a tropical storm by Thursday. If Paula hits the western tip of Cuba, weakening will be hastened. Given Paula's small size, once the inner core is disrupted, the storm could weaken very quickly.

The latest set of model runs from 2am EDT (6Z) continue to show a fair degree of uncertainty about the future path of Paula. There are two basic solutions. One solution, championed by the GFDL and GFS ensemble mean, takes Paula through or just south of the Florida Keys on Friday morning, then into the Bahamas Friday afternoon. The other solution, offered by the rest of the models, is for Paula to move very slowly over western Cuba the next few days, then circle southeastwards into the Caribbean, as a strong high pressure system over the Gulf of Mexico intensifies and pushes Paula to the south. This is the more likely scenario, given the current trends in how the models are depicting evolution of the jet stream pattern over the U.S. in the coming days. However, residents of South Florida, the Keys, and the Bahamas should be anticipate the possibility of Paula coming their way as a strong tropical storm on Friday.

Elsewhere in the tropics
The NOGAPS model is predicting the formation of Tropical Storm Richard 5 - 6 days from now, in the southern Caribbean off the coast of Nicaragua, near where Paula formed. The GFS has just a strong tropical disturbance forming there.

In the Western Pacific, Tropical Storm Fifteen has formed, and is predicted to be a major typhoon that will threaten the northern Philippines early next week.

Next update
I'll have an update between 3pm - 4pm this afternoon.

Jeff Masters