Threat of light wintry preciptation continues for Monday, forecast uncertainties remain

Good Saturday afternoon to everyone… this Winter Weather Update is sponsored by CBS Sports of Morganton, your hometown skiing, snowboarding, tubing and sledding retailer…

 

We continue to monitor the next storm system that will traverse the country and could have some impact on our weather during the day on Monday…

 

Right now we still think the potential for a little wintry precipitation is there on Monday but there isn’t a ton of model agreement even this close to the event. It’s a complex setup and not a very high confidence forecast at this time…but we’re going to break down what the models are currently indicating and how this all might pan out…

First, attention goes to the Western US as a piece of energy has come ashore the west coast today and is getting ready to traverse the Rockies over the next 24 hours. This storm system is actually the first in a pattern change across the entire nation as we are going to transition from a northern stream dominant flow to a more split-flow type of pattern.


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The upper energy will dive through the Rockies and the Southern Plains to a position along the Gulf Coast by late Sunday and early Monday. If the northern stream wasn’t still pressing down as strong as it currently is, we would be looking at a much stronger winter storm threat but the Pacific energy will continue to dive into the Gulf of Mexico, that will keep the deeper moisture along the Gulf…but it will not totally eliminate moisture all together. While all of this is happening, a residual arctic air mass will be in place along and east of the Appalachians.

 

Moisture that begins in the Mid-South region on Sunday will gradually translate into the interior Southeast US by Monday. It’s the exact timing that has the forecast in such conflict. Here’s a breakdown of model analysis…


 

The Global Forecast System model (GFS) is the fastest in trying to advect moisture across the Western Carolinas as early as Monday morning. If there is any validity to that, moisture will be falling into air temperatures that are in the mid 20’s with dewpoints in the single digits. That will result in a hybrid wedge configuration during the morning and early afternoon hours along and just east of the Blue Ridge. Precip amounts through midday would be light (.10 or less) with temperatures remaining below freezing along and north of I-40 through lunch time. This particular solution could yield some light freezing rain or may a sleet pellet at the onset.

 

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The European Model is slightly delayed with light moisture onset, it waits until around lunchtime to bring precipitation into the foothills. The low level cold remains in place and is hard to scour out through the afternoon hours. Infact the Euro after a brief spike in temps during the early afternoon drops temps back down to the 30-32 range as late as 7 pm on Monday…

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The short range models ironically are the least impressed of any model suite as it struggles to bring in measurable moisture east of the Apps on Monday, as a result temperatures jump up into the 40’s by afternoon eliminating wintry precip potential. Given how the current northern stream dominant flow has squashed recent storm systems, this solution given by the NAM cannot be ruled out.

 

 

So, as you can see this is not a very high confidence forecast for Monday. It’s still a wait and see pattern in regards to how this may evolve. One thing of interest is that the most recent model runs (12z) had the Pacific energy fully sampled for the first time. Tonight’s data will be important to see if any last minute trends could materialize…

 

 

For a storm overview there continues to be a lot of factors left to be determined. If there is one thing that we feel pretty confident about is that moisture in any scenario will be limited in scope. And in regards of precip type it would be more in the freezing drizzle/rain type, maybe a sleet pellet at onset. Snow does not look to be much of an option right now with warmer air invading at the mid levels of the atmosphere.


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As of this update, we are keeping the Winter Storm Index at a Level 1 status (Social Media Talk). We feel that the potential is still there and definitely worth monitoring and discussing, we just don’t see agreement to raise the level. The other big thing to take from this update is that light amounts of precipitation can impact nearly as much as heavier events, especially on local roadways. All you have to do is look back at last Sunday afternoon and the quick hitting icing that occurred along the immediate Blue Ridge with temperatures in the mid 20’s and how it impacted roads in sections of the coverage area.


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Our next update on this potential episode will be tomorrow…