NWS Little Rock, AR - Text Viewer

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Public Information Statement
National Weather Service Little Rock AR
600 AM CST Mon Dec 2 2024

...Winter Weather Awareness Week in Arkansas...

December 1st through the 7th is Winter Weather Awareness Week 
in Arkansas. The purpose of this week is to remind people what
winter weather can bring, and how to deal with hazardous winter 
conditions. Now is the time to prepare for the upcoming winter 
season.

Today's topic is the outlook for the upcoming winter. 

Overall, winter around here has not exactly been cold in the 
last three decades or so. Since the winter of 1990-91, temperatures 
were below average by at least a degree only seven times. Readings 
were above average by a degree or more eighteen times. 

Temperatures last winter were well above normal (by three to four
degrees). It was even warmer the previous two winters. But in the 
winter of 2020/2021, readings were colder than usual. That was 
due to Arctic air plunging southward through Arkansas all the 
way to the Gulf Coast in mid-February of 2021. Two big storm 
systems arrived from the 14th through the 18th, and deposited 
more than twenty inches of snow in central and southern 
sections of the state.

Weather can vary quite a bit from winter to winter, so 
forecasting what will happen is a challenge. The forecast 
usually starts with looking at water temperatures along
the equator in the Pacific Ocean.

If the water cools, we trend toward La Nina. If warming occurs, 
then it's El Nino. Both variables have a say in how the weather 
behaves across the country, especially when they become dominant. 
In the coming months, the pendulum will swing weakly toward La 
Nino, which favors warmer and drier than usual conditions across 
the southern states, and a colder and wetter scenario farther 
north.

In Arkansas, while a mild winter projected, it does not mean 
that cold snaps are off the table. Instead, rounds of cold air 
will likely be fewer than in a typical winter. The same rationale 
applies to the precipitation outlook. While there will be wet  
periods (and chances of wintry precipitation if cold air is in 
place), big slugs of moisture should be fewer than usual. 

As a side note, the degree of wetness will dictate how an ongoing 
drought improves or worsens moving forward. This will be evaluated
more closely as winter progresses.

It must be mentioned that the most recent huge episodes of snow, 
ice, and severe thunderstorms occurred with La Nina in control. 
However, confidence in extreme weather this winter is low given 
that La Nina will not be strong and may be short-lived.

Since La Nina is expected to be somewhat underwhelming this winter, 
the weather pattern may be governed at times by other variables such 
as the Arctic Oscillation (AO).

In the strongly negative phase of the AO, pressure is higher toward
the North Pole, and this sets up a blocking pattern. Cold air 
traversing Canada is forced to the south, and our temperatures 
drop.

In the winter of 2010/2011, there was a long term negative AO, 
and that led to one cold blast after another. On February 9th,
2011, one to two feet of snow blanketed the Ozark Mountains. 
Six to eight inches of powder accumulated in the Little Rock
(Pulaski County) area. It was a top ten snowy winter locally.

Such a lengthy negative AO is rare. Usually, AO phases are of 
short duration /days to weeks/, and are tricky to forecast compared
to a much more stable El Nino and La Nina /months/.

Whatever happens, we all know that the weather can be all over 
the place in this part of the world. It can feel like spring in 
January, and it can get really cold. That is an ordinary winter 
locally. Do not expect anything different this time around. 

If more precipitation falls than expected, we will have to 
watch for three things. If we are in the midst of a warm period, 
be wary of severe thunderstorms, which are not unusual. If there 
is a lot of rain, then flooding can become a problem. Finally, 
given a well timed shot of subfreezing air, that is a recipe 
for a big snow or ice storm.

&&

Additional information on the winter outlook from the Climate 
Prediction Center can be found at:

https://www.noaa.gov/news-release/us-winter-outlook-warmer-
and-drier-south-wetter-north

$$

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