Tropics in full gear – Igor is a strong category 4 hurricane in the central Atlantic, with Tropical Storm Julia further to the east. There is another area of interest in the Caribbean, which could form into a named system later this week.
Variable weather in the East – A disturbed weather pattern will bring several shots of wet weather into the Northeast and northern Mid-Atlantic.
Heat cranks away in the South – An area of high pressure will keep the South above normal throughout the week as the summer heat continues.
Cool air working into the northern Plains – A low pressure system diving south from northern Canada will bring below normal temperatures into the northern Plains through most of the week.
Igor is continuing its westward track early this week as it gets ready to recurve to the north and east during the second half of the week. It will continue to be a major hurricane through the first half of the week, but its strength will be in question during the second half of the week depending on how quickly it moves north. The current forecast will keep Igor well away from the U.S. coastline, but I wouldn’t be surprised if Igor ended up a bit further west than expected (though it would still be offshore). Julia is currently near the Cape Verde Islands and is expected to stay east of Igor throughout it’s lifespan, eventually recurving into the North-Central Atlantic.
A series of low pressure systems will bring cooler conditions overall to the Northeast as rain and afternoon thunderstorms roll across the Northeast and Mid-Atlantic today and during the second half of the week. These systems will entrain cold air down from northern Canada into the northern Plains during the second half of the week. Fall is coming to the North!
Meanwhile, a sub-tropical high is parked over the southern U.S., and it will keep most of the South, from the Desert Southwest to the Southeast, under warm temperature anomalies throughout the week. Areas along the Gulf of Mexico that experience onshore flow will have closer to normal temperatures.