Friday, December 11, 2015

Is it still December? The weather is acting more like April!

Very warm air is in place across much of the eastern half of the nation in a season known more for snowflakes up north and cool breezes down south than shorts and t-shirts!  Today's high (as of 3pm) of 77° ties the record for the date set in 2007, and we aren't done with record warmth!

Check out all of the potential records that could be tied or broken below. First, tonight's overnight lows, which will be in the mid 60s in the metro. Circled temperatures are potential "warmest minimum temperature" records:

Saturday's highs will be break records all across the Lower and Mid Mississippi Valley into the Ohio Valley and Midwest:

And again Sunday morning, more record warm low temperatures are likely to be broken, including here at Memphis (the caveat to those cities on the western side of the map being that Sunday's frontal system will likely mean daily lows will be set in the evening rather than morning):

With another couple of days of warmth ahead, that must mean the frontal system will be a doozy huh? Well, maybe not... at least as far as severe weather. The Storm Prediction Center's outlook for Sunday (below) shows the most likely chance of severe weather well to our south, along the western and central Gulf Coastal region into eastern TX and Louisiana. The light green area (which includes the metro) basically means that thunder is possible but severe weather is not anticipated.

SPC severe weather outlook for Sunday. The best chance of severe storms will be well to our south, though a rumble of thunder will be possible with the PM rain.
We think that this situation will need to be monitored fairly closely, so we'll do that. With temperatures already running above what computer models thought we'd see, and a pre-frontal trough (basically a weak front ahead of the main cold front) moving through near or just after peak heating on Sunday (late afternoon to early evening), we could end up with a little more unstable environment than the models currently depict. Until this morning, the SPC risk zone also stretched a little further north, up to the MS/TN state line. So it bears watching. Like our triplicate systems in November, this one will again have plenty of wind energy but is lacking in instability. Stay tuned.

As far as precipitation, a pretty healthy amount of water will be falling from the sky Sunday late afternoon through evening. We agree with this NWS map below (which agrees with computer models) that a good inch is likely and some places could see up to 2" is multiple downpours move overhead. Precipitable water (which measures the amount of moisture in a column of air over a point) will be nearly 1.5", which is near record highs as well (similar to a couple of those wet November events).

Forecast rainfall amounts through Monday, according to the NWS.
The other factor on Sunday in particular will be wind ahead of the weather system. We encourage you to tie down anything outside that you don't want blowing a few blocks to your north. Deflate the blow up Christmas decorations unless you want to show the kids how reindeer really do fly.

Behind Sunday's system, it'll be a bit cooler, but still well above normal temperature-wise. A mid-week system brings another chance of rain (much lower chances and less precip) but finally pushes temperatures back down to near normal (lower 50s for high, mid 30s for lows) to end the week.

Be sure to follow our Facebook and Twitter accounts listed below for the latest details on this weekend's weather and use the opportunity provided by warm weather to (finally) get those Christmas decorations up. Just be wary of the wind!

Erik Proseus
MWN Meteorologist

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