Good Saturday to one and all. Our awesome start to February rollds on and will continue to be with us into the first full week of the month. By next weekend, we see the first in a series of changes that take us quickly back into a winter setup for the middle and end of February.
Let’s begin with today and roll forward. Highs are mainly in the 50s for the entire state with the chance at a 60 in the south and west. Similar temps will be noted Sunday with a little more in the way of clouds moving in here. There’s still the small chance for a shower to impact far southwestern sections of the state.
The weather from Monday through Thursday looks good with temps generally in the 50s.
Things begin to change Thursday night and Friday as a storm system rolls into the region, dragging a cold front across Kentucky. This likely touches off rain and a few thunderstorms…
This kicks off a much more active pattern as troughs dig back into the eastern part of the country.
If we look at the reasons we are seeing the trend back to winter, we have to look at the various indices for signs of blocking in the higher latitudes.
Let’s use the Euro Ensembles for this illustration and we start with the Arctic Oscillation (AO). When it’s in a negative phase, it means we have some blocking going up in the arctic region. The EURO Ensembles average is the green line and the Control Run is the blue line. Both have the AO going negative over the next few weeks, indicating cold returning to the eastern US…
The North Atlantic Oscillation (NAO) is for the area around Greenland. When it’s in a negative phase, that indicates blocking and is a cold signal for the eastern US. Thise same two week period is also negative…
The Eastern Pacific Oscillation (EPO) also is a good indicator for cold in the eastern half of the country when it’s in a negative phase. This would essentially be a ridge over Alaska. The EPO take a little longer to fully go negative, but you can see how it gets there…
The Pacific-North American Oscillation (PNA) gives us a view of the west coast. A positive PNA is a ridge in the west and is a good indicator of cold and a trough going into the eastern US. You can see how this also goes positive…
So, all this would indicate a healthy winter pattern developing across the eastern half of the country. That’s exactly what the Weeklies have been saying for a while and it’s what, as you can see above, the EURO Ensembles are showing.
Here’s the EURO Ensembles from February 10-17…
I will have another update later today. Have a great Saturday and take care.
Great educational blog Chris on the most important oscillations. Will enjoy the mild and cheap heat weather over the predicted time period. Unless there is one good snowstorm ( a – NAO indicates this in the graph ) I’m in the spring and summer mode.
Enjoy your Saturday !
“Which Way” raised the question I’ve been pondering. The blue means below normal, but over this time frame is that REALLY cold or just chillier than usual. And I’m definitely with Schroeder on this: if we’re going to have cold, bring it on so as to extend dormancy, but when we flip the switch, let’s have a good spring. The plants could use one.
Probably will be dependent on the amount of snowfall on the ground.
Yeah, back in 2015 we had about a foot or more snow on the ground and the temperature the next morning, under clear skies dropped to -20 degrees. Radiational cooling applied.
I don’t usually put a lot of faith in the ensembles, but the coordination of the various Oscillations are much more reliable indicators of where our weather is moving, and that is back to cold. But I have serious doubts that the cold will be as deep as early Jan., unless we get a PV incursion. I think that overall warmer ocean temperatures plus the day-by-day increase in solar heating will limit the cold snap’s duration. 2 to 2½ weeks is my guess…
It all depends on the Polar Vortex weakening on how long the cold will stay, but its February and it’s warming up. The AO going negative supplies the cold, and the NAO going negative plus the PDO forms the precipitation pattern.
I had that happen to my sellable nursery stock many years ago. A hard freeze in April. Most years I got by without a lost of income.
Old saying : ” Spring in February is worth nothing. “
What a great blog today. Chris you are a great teacher of weather thanks for taking time to explain it. I sure learned something. I am with Schroeder bring some snows or bring on spring but I guess that would be bad if spring started this early. Yes Schroeder I join you on on enjoying the cheaper heat days mine seem to run non stop and my bill shows it lol. 53 degrees it’s nice.
Took advantage of today weather wash my car. I guess we better enjoy it while we got it.
If it rains, I know who to blame