Gulf of Mexico Disturbance 92L Disorganized; Baja Watching Hurricane Odile

By: Dr. Jeff Masters , 3:34PM,GMT on September 13,2014

A small area of low pressure in the Gulf of Mexico a few hundred miles west of South Florida (Invest 92L) is bringing heavy rains to the waters of the Florida Straits, but satellite loops show that this activity is poorly organized. Strong upper level winds out of the north are creating a moderately high 15 - 20 knots of wind shear, and the atmosphere is fairly dry to the north, interfering with development. Ocean temperatures are a very warm 30°C (86°F) over the Gulf, but the presence of dry air and high wind shear of 15 - 25 knots should keep any development slow until 92L moves inland over Texas on Monday night. Heavy rains from 92L will begin affecting Texas and the Mexican coast south of the Texas border on Monday, with 1 - 3" or rain possible Monday through Tuesday. None of the three reliable computer models for predicting tropical cyclone genesis develop 92L over the Gulf of Mexico. In their 8 am EDT Saturday Tropical Weather Outlook, NHC gave the system 2-day and 5-day odds of development odds of 20% and 30%, respectively. I put the 5-day odds at 40%, since 92L has a vigorous circulation, and the Gulf of Mexico is such a notorious place for tropical disturbances to suddenly blossom when conditions are marginal for development. The Hurricane Hunters are on call to investigate 92L on Sunday afternoon.


Figure 1. Latest satellite image of Invest 92L.

Tropical Storm Edouard not a threat to land
Tropical Storm Edouard continues chugging to the northwest at 12 mph over the Central Atlantic, and is not a threat to any land areas. Satellite images show that Edouard has lost most of its heavy thunderstorms, but the storm remains well-organized. With wind shear expected to diminish by Sunday and ocean temperatures expected to be warm, the official NHC forecast of Edouard becoming a Category 1 hurricane by Sunday night appears to be on track.


Figure 2. Latest satellite image of Edouard.

Tropical wave 93L
A tropical wave (93L) that emerged from the coast of Africa on Thursday was located a few hundred miles southwest of the Cape Verde Islands on Saturday morning, and was headed west to west-northwest at 10 mph. Satellite images show 93L has a good degree of spin and is fairly well-organized, but has little heavy thunderstorm activity. The system is headed into a region with cooler waters and dry air, and none of the three reliable computer models for predicting tropical cyclone genesis develop 93L. In their 8 am EDT Saturday Tropical Weather Outlook, NHC gave the system 2-day and 5-day odds of development odds of 20%.


Figure 3. MODIS true-color image of Invest 93L off the coast of Africa, at approximately 8 am EDT September 13, 2014. Image credit: NASA.

Odile becomes a hurricane
In the Eastern Pacific, Hurricane Odile became the 11th hurricane of season Saturday morning, intensifying to a Category 1 storm with 80 mph winds at 11 am EDT. Satellite loops show that Odile continues to grow more organized, but the hurricane's heavy rains are remaining offshore of Mexico. Odile may be undergoing a period of rapid intensification that will take it to at least Category 2 strength; the 12Z Saturday run of the SHIPS model gave Odile a 55% chance of intensifying by 30 mph in 24 hours. While all of the reliable computer models show Odile will track northwest and remain offshore of the southern tip of the Baja Peninsula, just a slight deviation to the east would bring tropical storm conditions to the coast. The 11 am EDT Saturday NHC Wind Probability Forecast gave Cabo San Lucas on the tip of the Baja Peninsula a 51% chance of seeing tropical storm-force winds of 39+ mph , and a 6% chance of hurricane-force winds. As Odile passes southern Baja on Monday, the computer models grow more divergent in their forecast for the hurricane's track, with several reliable models (the European and UKMET) showing landfall over the Central Baja Peninsula. The GFS model keeps the storm out to sea. Regardless of the track, tropical moisture flowing northwards from Odile's circulation is likely to bring heavy rains to Northern Mexico and the Southwest U.S. by the middle of the week.

Typhoon Kalmaegi forms east of the Philippines
In the Western Pacific, Category 1 Typhoon Kalmaegi continues to gather strength in the waters east of the Philippines, and is on course to hit the Philippines' Luzon Island on Sunday. Kalmaegi is then expected to cross the South China Sea and impact China early next week.

Hurricane expert Steve Gregory has a more detailed look at 92L and the rest of the tropics in his latest post.

Jeff Masters