Friday, January 11, 2013

If you don't like the weather, stick around...

What a gorgeous "spring-like" day today! After a couple of wet days, a mostly sunny, warm day is just what the doctor ordered as we head into a weekend that will easily be described as inclement, some night say a "split personality!" It will definitely be a tale of two airmasses as a potent cold front splits weekend weather in half.

A strong cold front positioned directly over the Mid-South Sunday morning will make for a tale of two weather patterns this weekend.

Saturday

Showers move back into the weather picture late tonight as a resurgence of moisture arrives from the south.  On Saturday, a very slow moving cold front will bisect Arkansas from northeast to southwest and waves of low pressure will ride along it, bringing a wet day to the Mid-South.  One low pressure wave will bring a round of steady rain and some thunderstorms during the morning and early afternoon hours as it moves by to the west, dropping a half-inch to an inch of rain. Then, a stronger low will move into the ArkLaTex area by late afternoon. This low will probably pull the front and rainfall back west just slightly, perhaps bringing a brief respite from the rain from late afternoon through the early evening hours. However, as it moves northeast, rain and storms will move back into the area overnight Saturday night.  Rainfall will be heavy with an additional 1-2" of rain expected Saturday night.  It will continue to be exceedingly warm and humid Saturday with temperatures starting in the 60s in the morning and topping out in the lower 70s despite the rain Saturday afternoon. Gusty south wind can also be expected, especially Saturday evening and night.



Sunday

The front will move slowly across the metro between midnight and dawn Sunday with heavy rain and thunderstorms likely as well.  Showers will continue throughout Sunday on the back side of the front with another half-inch of rain likely.  As the front moves through early Sunday, temperatures will fall from the 60s in the wee hours of the morning to the upper 40s by dawn.  Temps will continue to slowly fall throughout the day, reaching the upper 30s by dusk Sunday.



Scattered showers will continue Sunday night with temperatures in the 30s.  As cold air at the surface and aloft continues to move in, some rain could change over freezing rain or snow showers by dawn Monday, though any precipitation left over is expected to be light.  It won't take much freezing rain to create hazardous conditions for the Monday AM rush with temps near 30 expected though!  The best case is that precipitation completely moves out Sunday night before freezing air arrives.

Monday and beyond

Monday is a little tricky still as computer models disagree on the amount of moisture remaining behind.  Multiple models move another wave along the front to our east, spilling precipitation back over the area, which could be in just about any form with temperatures in the 30s all day - snow, freezing rain possible early, or maybe a cold light rain in the afternoon. One of the primary models, however, keeps us dry all day.

One computer model interpretation of possible freezing rain accumulation on Monday.  This model gives the metro about 0.10" of ice, which, if it verifies, could cause problems for transportation and commerce.  This is NOT a forecast, just a model interpretation, but it shows the the possibility of some icing.

The forecast to start the work week is highly uncertain!  It does look like the brunt of the precipitation will be well to our east Monday though, and the entire system will move out by Tuesday, leaving dry but cold conditions.  Highs in the 40s are expected all week with lows possibly in the 20s.


Severe weather chances

The Storm Prediction Center has the metro on the northeast edge of a Slight Risk zone on Saturday and Saturday night. The higher severe weather chances will be to our southwest, though some storms on Saturday could have strong, gusty wind.  Overnight Saturday night, a squall line is possible just ahead of the cold front, which could also bring a threat of damaging wind.  The tornado threat is low, however with sufficient shear in the atmosphere, they cannot be completely ruled out in the strongest storms.  Instability will be higher with this system than it was Thursday night, when a lack of unstable air resulted in showers but no thunderstorms in the metro.

A slight risk of severe thunderstorms is currently forecast just southwest of the Memphis metro on Saturday into Saturday night.  Damaging wind would be the primary threat.
Stay tuned to MemphisWeather.net via the links below for the latest on our wild weather weekend! We'll be sure to keep our social channels and forecast updated throughout the next several days.

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