Arkansas Winter Weather Outlook

In Ninja's Corner by Michael HookLeave a Comment

5:00 PM Update

Snowfall amounts have been raised a bit for the Little Rock Metro due to a longer duration of snowfall and colder temperatures. 2-4″ is possible with locally higher amounts. It is possible a heavy snow band could set up somewhere in central sections tonight and if that does happen, there could be higher amounts. The Winter Storm Warning continues through 6:00 AM.

1:45 PM Update

Additional counties have been added to the Winter Storm Warning. In central Arkansas, this includes Faulkner, Pulaski, Lonoke, Jefferson. Colder air is working into the area a little quicker and as the rain transitions to snow, the duration may be a little longer, and surface temps may be colder, leading to a increase in accumulations. For the immediate LR Metro, the accumulation amount has been increased to 2 – 3″ with locally higher amounts, especially in higher elevations and areas just north and east of the Metro.

Gusty winds will also accompany the forecast snowfall, which could lead to some power issues. Hazardous travel may develop later today/tonight as temperatures approach the freezing mark.

Stay tuned, as this storm continues to develop

7:00 AM

An interesting forecast continues to take shape across Arkansas on Saturday, January 15th. Maybe I should say complicated or challenging, because there are many factors in play with this forecast that for the snow lovers out there, some are going to be happy and some will be sad.

The weather systems (low pressure at the surface and aloft) will track towards and across our region today and tonight and bring wet and in some cases, snowy weather. Since you’re probably reading this because you want to know how much snow we might get, that seems to be the 64 thousand dollar question and to be honest, it could be different from county to county, city to city, and in some cases, neighborhood to neighborhood (maybe a stretch).

With this event, elevation is going to play a big role in who gets snow and who doesn’t due to temperatures being colder just above the surface which will allow for a longer duration of snowfall to accumulate. So if you live above 800 to 1000 feet you may see snow falling longer than someone just down the hill from you as those snowflakes have a longer travel distance and may melt in the slightly warmer air.

As the storm system pulls closer, rain will break out across most of the state where temps will be mainly in the 40s. Colder temps are noted in the west and NW parts of the state, so they’ll see a transition to snow earlier. As the surface low pulls across southern Arkansas, warmer air will be pulled into the system from the east and SE so for central and eastern Arkansas, it’ll be a bit longer before surface temps fall into the 30s. Most likely that will happen this evening. But, as the upper level low which is colder air aloft move over the state, it’ll be cold enough to support snow which will fall to the surface. This should happen across the north and west through the day and shift east during the late afternoon or evening and into tonight. So you may see it snowing even though surface temps are above freezing which happens from time to time when cold air aloft moves over us. I think some of the snowflakes might be large as well especially in those higher elevations of northern and western Arkansas.

Current model data suggests a transition to snow in the LR Metro anywhere from 8PM to midnight or so with our best chance of accumulations coming after dark. Amounts will vary based on elevation and also local conditions, valleys vs. hills, etc. as crazy as that sounds. Most of the model snowfall accumulations have been showing slightly higher amounts in western Pulaski and Saline counties vs. the eastern side, due to the hilly nature. So just remember, location and temperatures will be key. Overall amounts across the state will be highest in the mountains of northern and western Arkansas due to the forecast longer duration. Some of the eastern sections could see higher amounts vs. central AR due to the snow falling at a more optimal time (late night) when temps have cooled. Also, for central sections, the snow will be falling on a surface that is wet from previous rain and with marginal temperatures so it’ll take it longer to accumulate unless it the snowfall is heavy enough in intensity to overcome those conditions. This won’t be a dry snow either (associated with colder temps). This will be a wet, heavy snow with ratios lower than the normal 10:1 (10 inches of snow = 1 inch of water equivalent). This will be 8:1 or so. Winds will also be gusty this afternoon and tonight as the low pressure center pulls away, so if we get a wet, heavy snow, with gusty winds, some tree limbs could break off and possibly knock down some powerlines.

Ok, enough of the chatter…. I’ll share some images. Reminder, these are all from single model runs and can and will change from run to run. To keep up with the changing conditions today and tonight, you’ll want to monitor radar and temperatures.

Arkansas Winter Weather Advisory Map from the National Weather Service. Pink = Winter Storm Warning. Purple = Winter Weather Advisory. Blue = Winter Storm Watch all as of 7:00 AM

Model Snowfall Accumulation Maps

Below are some model snowfall accumulation maps and are subject to change. You’ll notice the higher totals appear to follow locations that are higher in elevation, or where the model forecasts a longer duration of snowfall. Do not take these as a forecast for snowfall or get excited as some of the totals shown in them as many other factors come into play and models are famous for showing high snowfall totals when in fact those don’t always materialize. I hesitate to even shown them without detailed explanation but people were interested in seeing what they indicated.

This is the HRRR model and it only went out to 10 PM at the time I posted this. In later runs, it will fill in more area.

Simulated Radar

Here is some simulated radar data showing when snow may start to mix or transition to in central Arkansas. Again, like the snowfall maps, these change from run to run and to get a handle on them, they have to be compared to what is actually going on at the time (live radar).

HRRR Simulated radar at 10 PM shows snow entering Pulaski County

So you can see by those simulated radar maps its a pretty dynamic system and there seems to be around 3-4 hours of snowfall potential in the Little Rock Metro which may end up giving us around 1-2″ based on the conditions I mentioned above (wet and somewhat warm ground, marginal surface temps) and there is a possibility that we don’t get that or some areas get accumulation and others don’t or even higher amounts. It’s crazy complicated!

Here is also some data showing the warmer air being pulled into the system from the east and SE which will may keep precipitation as rain longer. Temps will be cooling just above the surface so even through it’s above freezing at the surface, you may see snow falling.

Finally, here is a graphic from the National Weather Service that shows the different precipitation types. In most cases, we’ll be dealing with rain or snow, but there could be pockets where other precipitation types come into play for a short duration (sleet, freezing rain) depending on local conditions. I hope it brings you a better understanding on how these winter weather types evolve.

This is a dynamic system and I wouldn’t rule out some thundersnow in a location or two. At some point a band of heavy snow may develop which could dramatically increase snowfall amounts. The location of this band or bands probably will be in the Ozarks of northern AR but it will ultimately depend on the track these systems take.

I guess the good news is that this system won’t be a long duration event like last February with sunshine breaking out and above freezing temps forecast for Sunday, a lot of melting of what falls will take place.

Colder weather may move back in towards the end of next week and long range signs indicate even colder air moving into the U.S. from the arctic in the last week of January. Will this bring additional winter weather chances to Arkansas? We’ll see.

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