Rain Later, And MAYBE Some Snow

Rain is still forecast to move in later today. It will be mainly light rain and with temperatures well above freezing. As we go through the night, colder air will try to move in and some of the rain will change over to some light snow.

It appears the best place to see a change to snow will be in extreme NE Arkansas and SE Missouri.... and points east out of our viewing area. The surface low pressure is clearly seen south of us and parts of the southeast (LA, MS, AL, GA, FL) could see severe weather.

So how much snow is POSSIBLE... Remember, this is very conditional and this is just a model. Use this as a tool to see where the best "chance" to see accumulation will exist:

For my Nashville friends and family, you have a better chance of seeing some accumulation on grassy surfaces. A couple of inches can not be ruled out. Roads should stay fine in most locations. Here's a look at Sunday morning:

Have a great Saturday!
Ryan

Winter Weather Today (2/13/12)

I just got home from the Memphis Grizzlies game and I'm quickly looking at some data before I go to bed. Just for fun, let me show you the "snowiest" model and model run. This is the evening run of the NAM model. It shows the snow coming in shortly after lunch in Jonesboro. Of course, areas SW of Jonesboro would see it earlier. I'm not sold on this part of the model. I really think Jonesboro could start seeing flakes as early as 10AM if the atmosphere can moisten up fast. Time will tell.

Next, this model is showing 4" of snow. While that is possible, my 1-3" forecast is still the safe bet. Many areas may be closer to the 1", so when you look at that range... don't always look at the top number! 1" of snow in this area still causes issues though. ALSO, if we get some sleet mixing in (which I expect), it would lower the numbers

Last, this model still shows it ending as rain.That might happen, but if this cold air does not budge at the surface.. that would be freezing drizzle. That will need to be watched as well.

That's the quick and dirty forecast. Watch Sarah in the AM and I'll be updating Twitter through the day at @ryanvaughan

Note: I wish I could answer every question that you guys have for each particular town and time, but that' almost impossible. I hope you understand!

Be safe!
Ryan

Snow Tomorrow, 2/13/12

We're still set to have wintry weather on Monday (tomorrow). The storm has changed a little in the past few days, but it still looks like it could get a little slick by Monday evening. Here's the tricky part... How much? Take a look at this graph that shows the models and their different runs on accumulation:

So, of course we can't go on air and say that we'll see anywhere from 0-5" of snow. Viewers would not be that happy with a forecast that vague, even though we all love the vagueness of the Farmer's Almanac... but I digress. So, we have to look at several parameters to come up with the forecast. Looking at amount of precip, forecast track, and snow ratios... I'm thinking 1-3" for Jonesboro area... with a little more in the Ozarks. It's not a lot, but enough to cause some problems. don't just look at the top end of that number. Many areas may get closer to 1". Temperatures will be crucial as well. Of course, the models are a little spread on the temps as well:

If we stay near or below freezing, we will have more problems of course. One thing is for sure though, we're going to be warming over the next few days. This storm will be short-lived.

Despite the Winter Storm Watch we have across Region 8 now, I'd be shocked to see a Winter Storm Warming. I'm thinking we will have a Winter Weather Advisory... and if this start looking a little more juicy, we may see a warning. Stay tuned!

Ryan

Active Next Week

We have some active weather POTENTIALLY coming next week. The above image has a lot of stuff on it, so let me explain some of it. This is a tool we use to forecast and it is showing the morning run of the GFS model. It reads from right to left. The red line is the temperature, the green line is the dewpoint, and the bars represent precipitation.

First, lets talk precipitation. We now have rain in the forecast for Friday, as the front looks to have a little more moisture than previously thought... but still not a lot. It's the small area of green bars on Friday. Then there are two periods to watch next week. FIRST, is Monday. Cold air will be in place this weekend, but warmer air will be trying to move in on Monday. This poses a problem when trying to forecast precipitation type. I'll explain shortly, but the blue line is trying to indicate that it will start as snow. Not so fast though.. I do not trust the algorithm here that says snow. I'm thinking it starts as sleet. I'll explain why shortly.

Lastly, look at the red line climb by the middle of next week. That is warm air ahead of a storm modeled to come through on Wednesday. It's really early, but the dynamics and energy may be in place to support severe weather. IF it still looks like this in a few days, I'll dig in on the details. Now let's go back to Monday.... with this graphic:

This is a vertical representation of the atmosphere as indicated by the GFS model for Monday afternoon. The blue line is the freezing line as you go UP through the atmosphere. I have marked the area of the atmosphere that may be above 32 degrees. This area is important, because it is where the snowflakes would MELT as they fell. BUT, the GFS is showing about 1,000-1,100 feet of freezing air just above the surface. The drops (melted snowflakes) could refreeze and become sleet before they hit the ground. There is a small area of temperatures above freezing near the surface, but if this verified... it would likely not be enough to melt the sleet. Regardless, we would hopefully be above freezing at the surface, causing no problems on the roads. THIS IS STILL WAY EARLY THOUGH! Lots can change and likely will before next Monday. Stay tuned!

As you can see, forecasting precipitation type will be difficult on Monday, but we're up for the challenge!

Ryan

Sunday Morning Update, Tornado Threat 1/22/12

While you were sleeping, the Storm Prediction Center issued a Moderate Risk for severe weather across parts of Region 8. The above image is the TORNADO risk. The greatest risk is in Eastern AR, West TN, and North MS. The scariest part of this possible outbreak, is that the tornado risk will be at night. Make sure you have a way to wake up if there is a tornado warning. Weather radios, FREE Severe weather text messages from www.kait8.com, or another App. DO NOT DEPEND ON OUTDOOR TORNADO SIRENS! They are for outdoor use!

The latest data seen above is the RUC data. It shows sufficient lift, shear and instability to support tornadoes. It shows the worst weather to occur overnight when many are sleeping. Overnight tornadoes are one of the reasons that the area highlighted in the Moderate Risk has the highest death rate in tornadoes! Let's change those statistics!

Don't panic, just be prepared!

I'm heading to Church and then to work. I'll be keeping you posted via Twitter (@ryanvaughan) and on air.

Ryan