We're moving into the last third of August, and we're fast approaching the peak of the hurricane season. It should come as no surprise, then, that the tropics are rather active. For starters, there is still Tropical Storm Gordon, once a hurricane as it speed eastward across the Atlantic into and through the Azores. While that system is about to be declared extra-tropical, there's plenty more to keep a close watch on. Here's the latest visible imagery of the Atlantic:
A cluster of thunderstorms along and off the east coast of Mexico and south of Brownsville are partly associated with an old, old tropical depression from more than a week ago, and are also partly interacting with a weak frontal boundary. The combination of the two will keep these thunderstorms active for the next day or two, but because the feature is so close to land, any development would be slow to occur, and this may simply be an area favored for excessive rains going forward this week.
Meanwhile, farther out in the central Atlantic we find a tropical wave that has some organizational structure to it as it speeds westward at over 20 mph toward the Leeward Islands. Some of the initial computer models track this feature into the northeast Caribbean, then have it flirt with the northern Caribbean islands. The 0z GFS would imply a track to near the lower Florida Keys by Sunday evening:
It's much too early to make any definitive statements about the system, but there's at least some reason to be concerned for tropical development this week, and one that may ultimately have a greater impact on at least a part of the U.S. coast when all is said and done.
And even farther out in the Atlantic closer to the Cape Verde Islands there is yet another tropical wave, one that the Canadian model develops into a potent storm by this weekend, though its latest forecast has it well north of the Caribbean islands by Saturday evening, for what it's worth:
Again, these are singular model forecasts of tropical waves, and the general global models are usually not very reliable sources when putting together long-range forecasts that are trying to predict the development and movement of tropical waves.
There's plenty of other weather to deal with domestically. The Ohio and Tennessee valleys back to the Mississippi Valley and eastern Plains remain cooler than normal, a continuation of the pattern begun more than a week ago. The broad upper-level trough, though, will change over the next few days. The morning upper-level look:
Now, the Friday evening forecast:
This will allow for slow and steady warming of the atmosphere over the eastern half of the country. In turn, the atmosphere should gradually dry out, resulting in more sunshine from north to south and east to west, with less and less of a chance of a thunderstorm, especially from the lower Lakes and Ohio Valley into the mid-Atlantic and New England.
The West is, quite literally, on fire. Even Hawaii is dealing with a growing brush fire, and numerous blazes are reducing the visibility and posing a grave risk to life and limb and property in most western states thanks to a strong upper-level ridge that isn't allowing much tropical moisture to fuel the typical August thunderstorms.
The ridge will be beaten down by a couple of different troughs this week, one in the next 24 hours, and a much stronger one later in the week. This will knock temperatures down throughout the Northwest, but also steer moisture clear of these areas by and large.
Oh, and there will be some heat, too. Not nearly as much as we have seen during the spring and the bulk of the summer season, but it won't be completely absent, either. Look for some of that Western heat to appear over the eastern Rockies and Plains by midweek as many locations rise to 90 or better. The warmth will become a little more widespread Thursday and Friday before any front can trim the heat back this weekend.
A turn to much colder air over the Northeast and mid-Atlantic states will set the stage for a rain and snow storm later this weekend before it turns much warmer later next week.
It's warm now, but will turn much colder this weekend, with a storm threat later Saturday into Sunday. Warmth will return by the second half of next week.
Though it is cold now east of the Mississippi, with a couple of opportunities for snow into the weekend, a blast of warmth is due for much of the country east of the Rockies next week.
Warm air will once again surge eastward from the Plains to the East Coast this weekend and early next week. A strong storm next Tuesday and Wednesday will then be followed by colder air later next week.
A storm in Southeast Texas will generate severe thunderstorms this afternoon and tonight, and some wet snow on its western flank as it heads into the Ohio Valley tomorrow.
A major spring storm will move from Texas tonight to the eastern Great Lakes Wednesday night, producing heavy rain and severe thunderstorms, with a swath of heavy, wet snow on its western flank.