PATTERN IN MID ATLANTIC SEEMS FAVORABLE FOR SNOW & ICE — JAN 31 — FEB 3
It’s time to briefly talk about the middle of next week. As I stated in the recent video, and I have stated MANY times on the website… the Twitter page…. and here on the Facebook page the problem with La Nina winter on the East coast is that the upper air/ jet stream patterns during La Nina winters dramatically reduces the chances of getting the Big East Coast snowstorm. For those of you who are not weather Savvy the Big East Coast snowstorms occur when you have LOW pressure coming out of the Gulf Coast that moves off the East coast sometime close to Cape Hatteras and tracks in the northeast direction towards Cape Cod Mass. Now there are variations of this of course but that is essentially the basic East Coast big snowstorm track.
However as this image shows with La Nina. that is much less likely to happen.
Instead, the snowstorm track is actually favorable for the Pacific Northwest, much of the Rockies, northern California, the mountains of California and in the Midwest. As we have seen several times this winter, any possible East Coast LOW pressure systems have ALWAYS end up tracking well Inland -either tracking well Inland from the coast or up the spine of the Appalachians or perhaps tracking from Arkansas to Ohio to Buffalo like we saw with the last two systems.
WHY? Because of the Southeast US ridge.
WHY? Because of the persistent southeast US ridge this winter ? =LA NINA
In fact if you take a look at the historical record of Washington DC Richmond Philadelphia New York you will see that the number of snowstorms in La Nina at any one of these locations going back before 1900 that dropped more than 8 inches … is less than 4 and in some places, it is has only happened 1 time.
There is a way however, a way that the Middle Atlantic region and perhaps the Tennessee Valley can receive accumulating snow and decent accumulating snow with that. The only way that I know of where these regions can get accumulating snow during La Niñas is when an Arctic cold front moves through the region and then stalls in a west- east direction across the Gulf coast states. Then waves of LOW pressure develop along the front and they drive moisture into the cold air north of the arctic front.
This kind of weather event does NOT feature a large intense LOW pressure area that looks like a nor’easter. This kind of weather event is referred to as over running.
THAT is what we are looking at in the period front January 31 through February 3.
These are the basic facts that we know of at this point.
- The arctic cold front is going to move through on January 29 . Itt will initially bring rain to all areas of the East Coast except for the Northern New York State and New England.
2. The cold front will stall across the Southern states where LOW pressure will develop on the front on Monday January 30th. This LOW will bring significant rain from Alabama to Central and Southern Virginia. The HIGH pressure area will build into Iowa and begin to drive the cold air southward. The black line here represents the approximate position of the rain snow line. Noticed that by late on January 30th the rain snow line has moved as far south of Central Kentucky and Central Virginia.
2. A second area of LOW pressure is going to develop on the front across the Gulf coast states spreading rain into Tennessee Southern Kentucky Western North Carolina Georgia Alabama Mississippi Arkansas Louisiana. The rain snow line again will be somewhere across central and northern Kentucky and central Virginia so that when the precipitation moves north of the black line it falls as snow or snow and sleet. south of the black line it’s raining.
KEY POINT the position of the black line or the rain snow line is a GUESS. Small variations of the rain snow line can result in huge differences in the amount of precipitation you get and the type of precipitation. DO NOT TAKE THESE MAPS VERBATIM. Perhaps the cold air is stronger than the models are currently depicting.? Perhaps the cold air coming south will be weaker?
We don’t know. These are GUESSES.
3 After that surge of moisture moves through another area of LOW pressure with rain will develop in the Southeastern states on the morning of February 3rd as the cold air continues to sink southward. If the model data is correct all of Virginia is cold enough to support snow north of the North Carolina border as well as in northeastern tennessee. You could be ice in Central North Carolina depending on the low-level temperatures early on the morning of February 3rd.
4 Between now and Monday the only thing to do is to look at the data and see where the cold front is going to be .. where the rain snow line is going to be located and how much moisture will get pushed into the cold air and where.
The models are going to go back and forth with this event. The one good thing that this event has going for it is the fact that it is based upon La Nina and the strong Ridge in the southeastern states staying in place which of course has been the case all winter long. That is why the jan 29–30 cold front will stall.