Monday, August 28, 2017

Three More Potential Tropical Storms Developing

From Category 6:

Above:  Potential Tropical Cyclone 10 off the coast of Georgia and South Carolina, as seen by the GOES-16 satellite at 9 am EDT Monday, August 28, 2017. 
Image credit: NOAA/RAMMB. GOES-16 data are considered preliminary and non-operational
Tropical Disturbances PTC10, 93L, and 94E All a Threat to Develo
August 28, 2017, 1:31 PM
A Tropical Storm Watch is posted for portions of the coasts of South Carolina and North Carolina, thanks to the increasing development of an area of low pressure (formerly called 92L) located about 100 miles south-southwest of Charleston, South Carolina at 11 am EDT Monday. This system was designated Potential Tropical Cyclone Ten (PTC 10) by NHC on Sunday afternoon. Satellite images on Monday morning showed that PTC 10 had a modest amount of heavy thunderstorm activity that was gradually increasing in intensity and becoming more organized, but high wind shear of 30 - 40 knots was hindering development. The system was headed north-northeast at 9 mph on Monday morning, on a track that will take it very close to the Southeast U.S. coast on Monday and Tuesday. PTC 10 will bring heavy rains of 3 - 6” and rough surf to the coast of South Carolina on Monday, and to North Carolina and Virginia by Tuesday. The best chances for development into a tropical or subtropical depression or storm may come on Monday afternoon, when wind shear is expected at its lowest value this week, near 30 knots, according to the 12Z Monday run of the SHIPS model. In its tropical weather outlook issued at 8 am EDT Monday, the National Hurricane Center gave PTC Ten 2-day and 5-day odds of development of 90%. The storm is unlikely to gain sustained winds any higher than 45 mph as a tropical or subtropical cyclone, and will merge with a cold front and move to the northeast, out to sea, on Wednesday. An Air Force hurricane hunter plane will investigate PTC Ten on Monday afternoon. 
Figure 1. Projected 5-day rainfall from PTC 10 for the period Monday, August 28 – Friday, September 1, 2017. Image credit: NHC.
African tropical wave 93L expected to develop
A tropical wave that emerged from the coast of Africa on Sunday night was designated 93L by NHC on Monday morning. Satellite images on Monday morning showed that 93L had a modest amount of heavy thunderstorm activity that was growing in organization, with plenty of spin apparent in the cloud pattern. Wind shear was high, 20 – 30 knots, but was expected to fall to the low to moderate range, 5 – 15 knots, on Tuesday through Friday, according to the 12Z Monday run of the SHIPS model. This should allow the wave to develop into a tropical depression by Friday over the central tropical Atlantic....MUCH MORE
Saturday's heads-up:
Hurricane Watch: As Harvey Inches Back Toward The Gulf, Two More Atlantic-side Disturbances 

Also at Category 6:

August 28, 2017, 12:36 AM
Flood Calamity Continues In Houston and Beyond; Harvey Edges Toward Coast