African Wave 95L and Mexico's Tropical Storm Polo Little Threat

Satellite loops show that a tropical wave (Invest 95L) off the coast of Africa, a few hundred miles southeast of the Cape Verde Islands, has a moderate degree of spin and heavy thunderstorm activity. The wave is under light wind shear and over warm waters of 28°C (82°F), conditions that favor development, but the 12Z Saturday forecast from the SHIPS model predicts that shear will rise to the moderate range, ocean temperatures will cool, and the air surrounding the storm will grow drier by Sunday, making development unlikely. Our three reliable tropical cyclone genesis models give little support for 95L becoming a tropical depression, and in their 8 am EDT Saturday Tropical Weather Outlook, NHC gave the wave 2-day and 5-day odds of development of 10%. This wave will bring heavy rain showers to the Cape Verdes Islands on Sunday. 95L does not appears to be a threat to any land areas besides the Cape Verde Islands.


Figure 1. MODIS true-color image of Invest 95L off the coast of Africa, at approximately 8 am EDT September 20, 2014. Image credit: NASA.

Tropical Storm Polo weakening, little threat to Mexico
Tropical Storm Polo is steadily weakening due to high wind shear as it heads northwest parallel to coast of Mexico. With cooler waters ahead of it and continued high wind shear likely, Polo does not appear to be a significant threat to bring heavy rains or high winds to hurricane-ravaged Baja, Mexico. The 11 am EDT Saturday Wind Probability Forecast from NHC gave Cabo San Lucas on the southern tip of the Baja Peninsula just an 8% chance of experiencing tropical storm-force winds from Polo. Satellite loops show the classic appearance of a tropical storm experiencing high wind shear, with the low level center exposed to view and all the heavy thunderstorms limited to one side.


Figure 2. Lastest satellite image of Polo.

Tropical Storm Fung-Wong approaching Taiwan
In the Western Pacific, Tropical Storm Fung-Wong is expected to make landfall in southern Taiwan Sunday morning with sustained winds near 55 mph. Fung-Wong brushed the northern end of the Philippines' Luzon Island on Friday morning with sustained winds of 45 mph, bringing torrential rains that flooded the capital of the Philippines, Manila. The resulting flooding killed five people and shut down the city.


Figure 3. Rescuers use a rubber dinghy to rescue trapped residents after heavy monsoon rains spawned by Tropical Storm Fung-Wong flooded Marikina city, east of Manila, Philippines and most parts of the metropolis Friday, Sept. 19, 2014. Heavy rains due to a storm and the seasonal monsoon caused widespread flooding Friday in the Philippine capital and nearby provinces, shutting down schools and government offices. Local authorities reported thousands were evacuated early Friday from severely inundated communities, some under rapid-flowing flood waters more than neck high. (AP Photo/Bullit Marquez)

Jeff Masters