Well if you are like me, winter weather around the holidays just adds to the feel of the season. The lights on outside with snowfall just brings a sense of happiness to the air. Kids playing on snowy hills and for a moment we all seem to just have peace. Seems like that was forever ago as our snow drought continues since 2016. With Christmas now just 10 days away, I wanted to take a look at the weather you can expect not just here at home but around the Southern Plains as you begin the final preps for travel for the upcoming holiday.
Looking ahead towards Christmas week, the pattern will be rather quiet leading up to it. There will be a storm system in the region as well. Pattern will be fairly zonal, meaning that mild Pacific air will be seen versus the Arctic intrusions needed for winter weather around here. That will mean for not just Arkansas but the Southern Plains and Mid-South a snow less Christmas once again. Some early indications were there that we could see a system interact with colder air around this time frame, but I did not buy it given the lack of snow pack to our north and no real strong blocking signals needed for colder air. That being said, rainfall does look to be in the picture sometime between the 24th-28th time frame. Again timing will change given 10 days out. As you can see above, remarkable agreement in the pattern coming up this far out. Very unusual to get agreement this far out. Will we see a change. Certainly. But the consensus is if we do see precip, it will be rain versus snow this time around.
One big ingredient you need for winter weather is cold, subfreezing air. 32 and below. Occasionally 33 to 35 if the upper levels are cold enough. Neither will occur except for lows early in the period under clear skies without precip. Again, remarkable consensus on the pattern upcoming for the Holiday. A classic, mild, southern Christmas. With zonal to southwest flow, it is easier to get those warm air intrusions versus the colder air. If a low pressure system develops in the southwest which is depicted to occur, then you can get an influx of warmer, Gulf air. Now I am not saying we will see July 4th type weather, But given a warm Gulf still, warm air intrusions to 60s and MAYBE 70s will certainly be possible. If we get to warm and the low pressure track is just right, we will have to watch for severe potential. We have seen our share of severe weather threats during Christmas over the last few years and with warm air in place and a storm system it will need to be watched. Regardless as you can see, an above average temperature Christmas is depicted by the guidance as well. Can it change? Yes. But will it? Most likely not.
To further Coincide with the idea of a warmer pattern coming up and to see if guidance is matching the pattern, we tend to look at other things as well. Without any blocking to our north it is hard to get colder air, but the Oscillation index tends to give us an idea an on occasion can lead colder air. You want to see a strongly negative AO/NAO and a positive PNA typically leading up a forecast week or just prior as it typically takes about 6-10 days for the colder air to transport south. Another good indication of a mild pattern forthcoming, is a nearly neutral index on every one. No extremes either way and coincided with a strong Polar Vortex index not pictured in this blog which keeps the colder air locked up. So cold weather lovers for Christmas, I am sorry but all indications are a mild one ahead.
The Climate Prediction Center confirms my thoughts from the start leading up to Christmas and just beyond as well as confirms everything on guidance as well. Now this does not mean a heat wave. Average temps in Arkansas are in the 40s/50s this time of year. This is a percentage or a likelihood of above average temps and precip. So you could have a high of 55 and your average be 53 and this outlook verifies. If you want snow, this is not how you get snow. But if you like to fish, go out on a lake etc, this is a perfect outlook for you. Leading up to Christmas will be pretty dry, as indicated by guidance and the CPC. Heading towards the 1st of the year the pattern could get more active but with above average temps, any winter weather threats look negligible. All of this can change however and especially the latter part in the 8-14 day is most likely to change as a better handle on what has been a very active upper atmospheric pattern so far is seen the closer we get. For Christmas travelers, the outlook looks very good right now with any snow threats well to our north. So enjoy that time with family and enjoy the warmer air because Old Man winter is bound to show up soon. After all, our snowiest months of the season are ahead.
~Chief Forecaster Derek
Climate Prediction Center
Winter Weather Outlook For Tuesday, December 10th, 2019
Event: Cold air will be moving into the natural state as a surface low riding along the front near the gulf coast. Mixed bag of precip is expected mainly from a Mena to Jonesboro line points South and East. Transition will occur by sunrise for the northern most section of that line and by mid morning into the afternoon elsewhere. Due to dry air, north Arkansas will likely miss out on most of this. It is very likely that precip will mix a lot on Tuesday. Periods of just rain, periods of just snow or snow/sleet/rain. Some uncertainty still remains on how fast the cold air can get to this area as it will make the ultimate difference of no impacts to a decent winter weather event. Will discount the aggressive NAM at this time but will continue to monitor trends as it has been extremely consistent over several runs.
Snow/Sleet Amounts: Trace to Up to a half of inch of snow/sleet is possible especially in the delta up to northeast Arkansas. Will monitor trends as banding could lead to locally higher amounts in isolated areas.
Black ice will be a problem tomorrow night into Wednesday as little wind with this event will cause bridges & overpasses to become slick.
Please stay tuned for the latest on this winter weather event.
~Chief Forecaster Derek & Senior Forecaster Cameron