The tropical weather map is going to start the week in fairly quiet shape. In its Sunday update The National Hurricane Center has downgraded Erin to a “post tropical storm” and is discontinuing any further updates.
In his Sunday blog entry, Weather Underground founder Dr. Jeff Masters wrote an unofficial obituary for Invest 92. “The tropical disturbance (92L) that was over the Gulf of Mexico the past few days has now degenerated into a trough of low pressure with little heavy thunderstorm activity, and is no longer a threat to develop. However, a flow of moist tropical air will take some of the remnants of 92L northwards over the Southeast U.S. over the next few days, bringing a swath of 3+ inches of rain to the Gulf Coast from Louisiana to the Florida Panhandle.”
So much for the two main threats we've been monitoring for the past few days. The latest area of interest is a tropical wave just off the African coast the NHC has labeled “Invest 94”. As has been the case so often this hurricane season, Dr. Masters says conditions are less than ideal for tropical cyclone development. “The 12Z Sunday run of the SHIPS model predicted that during the next five days, wind shear for 94L will be mostly in the moderate range, and ocean temperatures will slowly cool to 26.5°C. These conditions should allow for some slow development. As usual, dry air from the Saharan Air Layer will likely be an impediment to development, as the 11 am EDT Sunday SAL analysis showed a large pulse of dry air and dust exiting from the Sahara just to the north of 94L. The Sunday 06Z run of the GFS model and 00Z run of the ECMWF model did not calling for 94L to develop.”
Storms that form off the African coast can take quite a while to threaten any of the large land masses and the NHC for the moment is giving Invest 94 only a 30 percent chance of developing into a tropical cyclone by Friday.