CHANGE OF SEASONS, AGAIN...
It's April. The sun is strong, the days are longer, flowers are popping up, and the grass is greener. Unfortunately for us, we're stepping backwards as many of us have (or will see snow showers before Friday comes to a close). It goes without saying, instead of growing warmer, were turning colder. Just look at Friday's projected temperature departures. Much of the central U.S. is 10 to 25 degrees below normal.
Here's the culprit, a massive, nearly stationary upper air low that continues to wrap clouds, chilly air, rain and snow showers around its circulation center.
At 500mb the jet stream pattern shows the cold core low and its deep trough penetrating the nations heartland.
It's actually remarkable to point out that some part of the Midwest has seen snow everyday since April started (Friday will be day 8). Here's how much has accumulated over the 7 day period ending April 6th.
Since Wednesday, more than a foot of snow has fallen in northeast Minnesota.
By Thursday evening the snow had worked its way into the NW half of Iowa and it's expected to be scattered around my area in a showery form late Thursday night and at times Friday. As I've stressed all week long, these snow showers are largely driven by instability as opposed to the forcing you would associate with a front or an organized storm system. As such, the snow showers are cellular which makes them hit and miss and scattered in nature. They don't stay in one place long and the short duration limits amounts. Some of the stronger cells may produce a quick dusting in a few spots but for most of us the impacts will be mental (who wants to see snow at this time of year). Total liquid equivalent from the showers is likely to be less than .05". Here's what models are suggesting for potential snow amounts.
The 3k NAM
IMPROVEMENT FOR THE WEEKEND WITH A WARMING TREND...
After Friday's chilly readings that may struggle to break 40, the upper air low reluctantly begins to advance to the east over the weekend. That's expected to result in dry conditions and a warming trend that carries into next week. Highs Saturday should at least reach the low 50s and Sunday highs in the range of 60-65 will make for a pleasant, more seasonal end to the weekend.
WARMER AND POTENTIALLY STORMY NEXT WEEK...
Southwest flow aloft returns with a vengeance next week as another potent storm cranks up over the west. The GFS and EURO are at odds as to how the pattern sets up. The GFS seems way over done with a cold front that it plows across the region Sunday night. This would send much cooler and drier air through the region and limit warming, potential significantly. The only rain it suggests is Tuesday night and early Wednesday and that is light.
The EURO has a whole different solution and one that portends much warmer temperatures going from near 60 Monday into the 60s and 70s Tuesday and Wednesday. With a nearly stationary front near the region it's warmer and more moist look suggests the potential for convection with periods of showers and thunderstorms every day. It's also showing CAPE (instability) and shear which could mean stronger thunderstorms in some part of my area. Additionally, deep moisture suggests a heavy rain threat if the front gets hung up in the region as advertised.
With the amplified SW flow that's indicated, I suspect the GFS is too far south with cold air and the front will end up further north paralleling the upper air flow closer to what the EURO depicts. Additionally, the EURO's stronger system argues for a slower progression of the primary storm mid-week which also goes against the the GFS. I prefer more of a compromise solution with a distinct lean towards the EURO leading to a warmer and more active period. Still lower than average confidence than I would like to see meaning changes are still a real possibility going forward.
To show you the contrast in what the two models are portraying, I'll show you the differences in temperatures and total precipitation. Temps first.
This is forecast precipitation Monday through Thursday. Big differences between the two models in my area due to the location of the front discussed above.
No doubt about it, there is a lot of weather on the table over the coming 7 days. Lot's of variety too from cold to warm and snow to thunderstorms. I like that party! Happy Friday and roll weather...TS