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Hold Onto Your Hats!

| February 10, 2013 @ 8:05 am

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The title tells it all – Hold Onto Your Hats! The weather over the next week is going to be especially active with all kinds of weather for us to deal with including a severe weather threat, heavy rain/flash flood threat, some mild weather, plus a real chill down with even a snow threat for next weekend! Wow – think I’ll just go back to bed!!

Today the clouds thicken up and the rain moves in. The atmosphere still had a small dry layer around 800 millibars last night, so some of the very early rain could evaporate in that dry layer. However, the dry layer is fairly shallow so it should not take long after the precipitation arrives for it to wipe out the dry layer. There is a multi-faceted threat with heavy rain a possibility as well as some potential for severe weather. And it appears that all modes of severe weather may be possible including damaging wind, hail, and isolated tornadoes. But we are once again facing a low CAPE and high shear environment. Helicity values at midnight tonight go up to nearly 700 while CAPE values go up to around 500 to 750. All of these support the severe weather threat. But there is one item of concern to me. The GFS MOS guidance as well as the NAM only indicate dew points climbing into the mid 50s. So this could be a limiting factor for severe weather, but not a limiting factor for heavy rain. NWS offices across the Southeast US have issued flash flood watches because of the threat.

The closed low aloft moves into the Great Lakes but while the ridge over us dampens, there is no strong push to move the front, so it is going to stall probably over South Alabama. But that keeps us with a threat of rain. The next system comes out of the southern Rockies on Tuesday and passes us at midday on Wednesday. So surface lows will continue to generate and move along the stalled front which means more rain for Monday evening and Tuesday with the rain ending Wednesday morning. Rainfall amounts over the next five days are likely to be in the 2 to 3 inch range, and the QPF guidance suggests 4 to 5 inches across Southwest Alabama.

But then we face another change. A strong disturbance moving out of the North Central US begins to set up a long wave trough position over the eastern half of the country. This means we’ll see some really cold air plunge into the Southeast US by Friday and Saturday. In fact, Saturday could be one of those days where temperatures struggle to get out of the 30s – yes, the 30s. And to put the cherry on top of this cold air, the GFS is suggesting that a disturbance moving across the area Saturday morning could bring some moisture with it and produce snow. Now these kind of patterns do not generate large amounts of snow, so we’re looking at snow flurries or perhaps enough to produce a dusting especially across higher elevations of Northeast Alabama.

Voodoo country continues to show an active flow regime. While it shows a nice warm up that I mentioned yesterday, it is also showing a very potent storm around the 25th of February that could bring a big winter event to the Central US and severe weather to the southern portion of the US. But remember this is voodoo country, so we’ll watch to see how this evolves.

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Stay tuned to the Blog for later updates on the developing situation. James should be back with the next Weather Xtreme Video barring the need for severe weather coverage early Monday. Have a great Sunday and Godspeed.

-Brian-

Category: Alabama's Weather

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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