Unseasonable Warmth Continues As Spring Arrives Early
Ridge Brings Warmth And Quiet Pattern
Climate Prediction Center 6-10 Day Outlook, Temperatures
The jet stream has begun to lift northwards and, in doing so, warmer temperatures that are normally seen in April have started to make their way into the Northern Plains. A great visual to see the extent of the warm air is by looking at the thickness from 1000mb (near the surface) to 500mb (about the middle of the atmosphere).
500mb – 1000mb Thickness for March 12th
This map helps meteorologists determine if it’s too warm for precipitation to fall as snow at the surface. The 540 line (located where the light green begins) helps us know where the freezing temperature is at a certain point in the atmosphere. However, this map also helps, visually, us see just how far north/south the warm/cold air is. Here, the 540 line is well into parts of Canada which means that much warmer air has been surging northwards meaning that places like South Dakota, Minnesota and Iowa, are too warm for snow.
As the jet continues to lift more northward, not only will we see warmer temperatures but it will also be harder for us to receive any precipitation. If you imagine the jet stream as a river and high/low pressure systems as leaves, the jet guides them along its path. Since the jet is moving northwards, places like the Northern Plains will see a decrease chance in precipitation as low pressure systems will mainly stay off to our north. However, this doesn’t mean that all precipitation chances are gone, it just means that it will be harder since most low pressure systems and their ability to help produce precipitation will be north.
Climate Prediction Center 6 – 10 Day Outlook, Precipitation
Though we are seeing warmer that average temperatures, our day time highs will be 15° to 20° warmer than usual for early/mid March, this doesn’t mean that we have excluded all chances of seeing cooler temperatures are snow. Spring, and fall, are call transition seasons because the air masses are changing. Since we’re entering spring, the cooler air is returning north and the warmer air is rising out of the south. Until the warm air has replaced the cold air, low pressure systems will still pull some cold air southwards following the path of the jet stream. With more moisture being lifted north with the warmer air, there’s still a chance that a low pressure system will pull enough cold air and moisture that we could see some snow. Not to mention that March and April are the snowiest months for the Northern Plains.
Normal Temperatures for March
So get outside and enjoy the warmth now because in a few short weeks, we could be seeing the return of Old Man Winter but for now… we’ll enjoy this early taste of spring.