TD 7 dies; 93L little threat to develop

Tropical Depression Seven is dead, ripped apart by moderate wind shear of 10 - 20 knots this Saturday morning. The storm was too small and fragile to survive the shear, thanks to dry air from the Sahara that had infiltrated the storm environment. None of the reliable models forecasts that TD 7 will regenerate as it tracks westwards across the Caribbean over the next four days. The remains of the storm should arrive in Mexico's Yucatan Peninsula on Wednesday.


Figure 1. Morning satellite image of the remnants of TD 7.

93L
A large tropical wave(Invest 93L) is located in the Eastern Atlantic about 300 miles northwest of the Cape Verde Islands. Satellite loops show a pronounced spin to the atmosphere at mid levels, but little in the way of heavy thunderstorm activity. The latest Saharan Air Layer Analysis from the University of Wisconsin shows that there is a large area of dry air from the Sahara surrounding 93L, which has infiltrated into the storm. This dry air will be a significant impediment to development during the coming week, as the 8 am EDT run of the SHIPS model predicts dryness at mid-levels of the atmosphere will increase during the next five days. None of the reliable computer models develop 93L during the coming seven days, and the storm is expected to move west-northwest and then north, recurving well to the east of Bermuda. In their 8 am Tropical Weather Outlook, NHC gave 93L a 20% chance of becoming a tropical depression by Monday morning.

I'll have a new post on Sunday.

Jeff Masters