SPRING HAS SPRUNG, OR HAS IT...
What a fantastic day Wednesday was. I took a walk with with Nimbus (my faithful dog) in short sleeves and gym shorts. The birds were singing and the motorcycles were out. I went by the elementary school and it was a bee hive of activity. I could hear the kids (all without coats) laughing and screaming two blocks away. The neighborhood was alive with "spring fever". I was so inspired I washed and vacuumed both vehicles and grilled some burgers. The only thing that would have made it better was if Russia took its soldiers, bombs, and missiles and went home, where they belong! Vladimir, you are a very small man with immense power. Find what's left of your soul, open your heart, the world demands it. Ukraine, your country, and the world deserves it. Give peace a chance.
WARMEST DAY OF THE YEAR SO FAR...
Back to Wednesday and its warmth which was notable. The high in the Quad Cities soared to 62 at the NWS in Davenport and (64 at the Quad City International Airport in Moline). Keokuk hit 70 and Burlington fell just short at 69.
For many of us, yesterday's highs were the warmest since December 15th when the Quad Cities peaked at 73. I've posted all the highs at the NWS office in the Quad Cities since December 15th. All the days in red were 50 degrees and above. All the yellow boxes are highs of 20 degrees or below. (11 of each) Overall its been a weird winter with plenty of ups and downs in temperatures.
The warmth of Wednesday has already passed us by and today we get what our neighbors to the north experienced yesterday. Notice how it was 80 around St Louis but with snow on the ground in northern Minnesota and Wisconsin highs were confined to the low to mid 20s.
We won't be that cold Thursday but highs will be back in the mid 30s north to the low 40s south, a good 30 degrees colder than 24 hours ago. There's also a chance of a some scattered light snow or flurries but nothing more than a dusting is expected.
The chill won't be around long as a strong low pressure takes shape to the west that could bring strong thunderstorms to the Midwest Saturday. After highs in the 45-55 degree range Friday, readings will soar Saturday into the upper 60s and low 70s, making it the warmest day of 2022 so far.
Here's the set-up Saturday evening as a deepening 995mb surface low treks through WC Iowa
The unseasonal warmth increases water vapor creating instability which is manifest in the form of CAPE, shown in blue below Saturday evening. CAPE stands for convective available potential energy for thunderstorm development.
With the CAPE in place, a trigger is needed for storms and that comes in the form of a cold front and its attendant dry line. Notice dew points in eastern Iowa are in the upper 50s while in western Iowa behind the front they have dipped into the upper 20s. The dense dry air will undercut the moisture ahead of it as it surges east. That's the forcing necessary to get active storms to develop. While the CAPE is nothing to write home about the shear is significant and a few low topped supercells are possible. At the least, QLCS tornadoes are a threat to monitor in the days ahead. The biggest negative seems to be moisture and that is the key parameter to watch going forward. More of that and things get much more interesting.
The lightning flash density product off the EURO shows a couple lines of active thunderstorms toward evening.
SPC has issued a slight risk for severe weather Saturday.
Assuming thunderstorms do develop, some decent and much needed rain is on the table, at least in spots. The way things are lining up the northwest half of my area is more likely to see the more significant amounts. Here's what the EURO and GFS are indicating for rain totals from the event.
Behind the storm Sunday will be a dry blustery day with temperatures back in the 40s. As the colder air deepens Monday another disturbance arrives from the southwest and brings a chance of snow. This is the next forecast challenge. Models are still not in sync on the track or intensity of the system but do point towards a band of accumulating snow impacting some part of my area. The raw model output currently indicates snow totals that look like this. Obviously it's still early and these are not forecasts, just guidance that helps us determine trends and snowfall placement.
After this the pattern has the appearance of winter during the 6-10 day period ending March 15th. The GFS 10 day temperature departures look this. Yuk...
I also suspect there will be some snow in there somewhere but I've got enough on my plate to even speculate on that right now. With that, I bid you a good day...and don't forget the coat! Roll weather...TS