Nick's Weather Blog: December 23, 2015 Severe Weather Forecast

Nick's Weather Blog: December 23, 2015 Severe Weather Forecast
(Photo source: WDAM First Alert Weather Team)

PINE BELT - Good morning, everyone. Here is a nerdy, followed by a not-so-nerdy, look at today's severe weather threat.

Showers and storms moving through the area this morning are mostly rain and wind with some thunder and lightning. But after these storms pass, the Pine Belt isn't in the clear.

The threat for severe weather today will persist into the afternoon.

The nerdy version:

Mesoanalysis shows that a plume of warm moist air will ride into the area from the southwest out ahead of a cold front and area of low pressure. While the most sheared environment will be to the north of I-20, there will be sufficient low-level helicity, shear, and lapse rates for the development of severe weather in the Pine Belt, too. Short-range models do indicate that the storms this morning may have done enough to work-over the atmosphere. This would  keep the chances of storm development in the afternoon down a bit. Latest HRRR weather model guidance shows a lack of storm development this afternoon because of the storms this morning. Will wait for subsequent runs before changing forecast. But, as has been said the last week, this is a boom-or-bust day. If storms develop this afternoon - due to the high CAPE values, shear greater than 45kts, helicity values over 250 and a Sig Tor value above 2 - they could develop, and turn severe rapidly.

The Storm Prediction Center in Norman, Oklahoma has issued a "Slight" risk with a 5% tornado risk because of the aforementioned parameters. The main concern with storms today will be rainfall rates up to 2" per hour, winds gusting more than 60mph, hail up to the size of quarters or half-dollars, and isolated tornadoes.

The timeline puts this first batch of cells to the northeast of the Pine Belt by 11am. The next round of storms will be discrete supercells which may develop quickly starting around 2pm. Perhaps earlier if the sun peeks through the clouds.

Now, the not-so-nerdy version:

Shower and storms this morning will pass to the northeast during the next few hours. After a break in the action, more storms may develop this afternoon depending on how much these morning storms zapped the energy out of the atmosphere. Some of these storms may turn severe. The main concerns will be heavy rain, damaging winds, small hail and a few isolated tornadoes. The Storm Prediction Center in Norman, Oklahoma has issued a "Slight" risk for severe weather today. That is a "2" on a 1-to-5 scale, with 5 being the highest. The SPC has also given us a "5%" tornado risk. That means you are five-times more likely to see a tornado today than any other day.

- Chief Meteorologist, Nick Lilja