Showers Today, Drier Saturday, Unsettled Again Sunday and Monday

| August 4, 2017 @ 7:11 am

The Alabama sky has a mixture of clear and cloudy areas this morning along with some patchy fog that is reducing visibility to 1 mile in some locations. Fog should dissipate by 9 am. The front to our northwest is forecast to continue moving slowly southeastward today and Saturday, so we are likely to see showers become a bid more numerous during the afternoon and early evening. Clouds and the presence of showers and thunderstorms should keep highs in the range of 85 to 88.

While the upper trough moves into Southeast Canada on Saturday taking the surface low with it, the surface front will settle into South Alabama Saturday pushing some drier air into the Tennessee River Valley. I think the Tennessee River Valley area will be shower free on Saturday. Best chances for showers will be across South Alabama and the Alabama/Northwest Florida coastal area. That leaves Central Alabama between the drier air to the north and the wetter air to the south. We’ll probably have to retain some small potential for showers, but most of us will be shower free. Temperatures Saturday afternoon will reach the upper 80s.

As the upper trough moves further away from us across Southeast Canada, the upper flow across the Southeast US will become nearly zonal. While the overall flow will be zonal, there will be small short waves embedded in this flow that will be helpful in enhancing rain chances. One of those will be present Sunday and the SPC has drawn a marginal risk for severe storms over the northern third of Alabama along with parts of Mississippi, Arkansas, Tennessee, and Kentucky as a weak surface low develops over North Central Texas. Our main threat will come in the form of damaging wind. Highs again should be in the upper 80s.

A weak surface low with the embedded short wave trough will help to bring the frontal zone back north and increase the chances for showers and thunderstorms on Monday. MOS guidance has 62 percent for the probability of precipitation Monday. Added clouds and more numerous showers should hold the highs in check with most places in the middle 80s.

The upper pattern remains nearly zonal from Tuesday through Thursday with those pesky short waves embedded in the flow that should help to enhance rain chances. The problem for the forecast today is timing those accurately that far into the future, so forecasts may have some adjustments with time. The primary forcing will come with the heat of the day, but those short waves could account for showers during the overnight hours. Highs will be mainly in the middle 80s which is not too bad for the first half of August.

Rainfall through Wednesday morning will be quite varied across the state of Alabama. Up to 3 inches may be possible along the Gulf Coast as well as the Tennessee River Valley with amounts for much of Central Alabama in the 1 to 2 inch range.

Wednesday we have the potential for development of a tropical system that is forecast to move across the Caribbean into the Southwest Gulf of Mexico. You’ll need to watch the video to see the tropical development which has quite different looks depending on whether you are watching the GFS or the ECMWF.

Speaking of the tropical Atlantic, a large area of showers and thunderstorms near the west coast of Africa was associated with a tropical wave. Environmental conditions are forecast to be conducive for gradual development, so a tropical depression could form by early next week from this disturbance. This system is forecast to move toward the west or west-northwest at 10 to 15 mph for the next several days. The GFS is pretty bullish on developing this system as it moves by north of the Leeward Islands. We’re out into voodoo country, so you’ll have to be careful about making a forecast here. But the GFS brings what appears to be a very strong tropical system just north of the Bahamas recurving it to the northeast as it approaches the Southeast US Coast. Unlike yesterday, the GFS recurves the system so that it produces a glancing blow to coastal North Carolina. This is not until the 15th of August, so there is going to be a lot of time and numerous model runs before we can settle on a consistent track for this potential storm. By comparison, the ECMWF doesn’t seem to think this system will develop with no sign of it in the longer range.

Closer to home, an area of disturbed weather had developed just off the coast of South America in the eastern Caribbean. This area is forecast to move westward into the Southwest Gulf of Mexico on Wednesday. Both the GFS and the ECMWF take this system into Mexico, but the ECMWF was very close to Brownsville and much further north than the GFS. It’s also worth noting that the ECMWF was much strong

At the beaches of Alabama and Northwest Florida, the chance for showers will continue through the weekend and into the start of next week. No complete washouts but showers could be fairly numerous at times. You can expect to see highs mainly in the middle 80s and lows in the upper 70s. Click here to see the AlabamaWx Beach Forecast Center page. The Beach Forecast is partially underwritten by the support of Brett/Robinson Vacation Rentals in Gulf Shores and Orange Beach. Click here to see Brett/Robinson’s Own Your Summer specials now!

Looking out into voodoo country, we have some tropical mischief to deal with as noted above. The upper flow over the eastern US remains in a weak trough with the ridge axis over the West along the spine of the Rockies. As the tropical system moves by coastal North Carolina on Tuesday, a strong closed low was forecast to drop into the Great Lakes Region as the Bermuda high nosed into the Southeast US. But the traveling systems across Canada should be enough to keep a trough pattern over the Mississippi River Valley. I don’t think there is any doubt that we need to use the phrase, “Stay Tuned,” for the next couple of weeks.

Don’t forget you can listen to our weekly 90 minute netcast anytime on the web, or on iTunes. This is the show all about weather featuring many familiar voices, including our meteorologists here at ABC 33/40.

I expect to have the next Weather Xtreme Video posted here around 7 on Saturday morning. Be sure to check back often for updates on the Alabama weather picture. Have a great day, and Godspeed.



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Category: Alabama's Weather, ALL POSTS

About the Author ()

Brian Peters is one of the television meteorologists at ABC3340 in Birmingham and a retired NWS Warning Coordination Meteorologist. He handles the weekend Weather Xtreme Videos and forecast discussion and is the Webmaster for the popular WeatherBrains podcast.

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