NEXT STORM UP...

A strong low pressure system moving from the eastern Dakotas into western Minnesota spawned thunderstorms over Nebraska late Thursday that swept across Iowa and Illinois Friday. Initially a few thunderstorms produced large hail, then as the main squall line moved through the threat transitioned to damaging wind gusts and isolated tornadoes. Storm reports are still being collected and analyzed, but several tornadoes and numerous wind gusts of 60 mph have come in (one of 84 mph in Newton, Iowa). Over the past 2 days, 30 tornadoes have been reported, with nearly 600 incidents of severe weather.

This radar image shows the QLCS line of storms approaching Iowa City at 6:50 am Friday morning. Quasi linear convective systems (like this one), are known to be big wind producers. However, they often form in environments where there is enough shear to produce brief tornado spin ups thanks to a big rear inflow jet. On the nose of that jet structure, a tornado warning was issued for Iowa City and Johnson County, Iowa Friday. Just one of numerous warnings issued along the line.

Pravin Gupta, a chasing buddy of mine, snapped this image on the east side of Iowa City at 7:02 am. This occurred at a time when a tornado vortex signature (TVS) was evident on radar. It's hard to tell if the tornado is on the ground at this time, but numerous trees were downed in parts of Iowa City as the storm barreled through.

2024 is turning into a significant tornado year across the nation, especially here in the Midwest. 86 tornadoes have been reported in Iowa, the most of any state in the nation. Even more impressive is the fact we are just now entering the heart of the severe weather season locally.

As shown below, inflation adjusted tornadoes are indicated to be in the 90th percentile and climbing steadily.

Not using the inflation adjusted approach, preliminary data suggests 906 twisters have struck the nation so far in 2024. 47 of them have been strong to violent, reaching EF2 or greater intensity.

The numbers are going to grow this weekend, especially over the central Plains Saturday. SPC has issued a large moderate risk outlook area (level 4 of 5) covering much of Kansas and Oklahoma. Several strong long tracked tornadoes are expected.

The hatched region below indicates at least a 10 percent chance of an EF2 or greater strength tornado. Hopefully, they stay in the open country.

The impacts of Saturday's storms will remain well west of my area, with a beautiful spring day anticipated here thanks to high pressure. That provides a much drier air mass, sunshine, and highs that should climb into the mid to upper 70s. Light variable winds will gradually turn to the southwest in the afternoon. This is clearly the pick day of the holiday weekend!

Sunday, the Plains storm lifts east, but we are not in the warm sector and that means outside a couple strong elevated storms in the far south, a more gentle brand of showers and storms is expected in my area. The bigger concern is another batch of rain that in spots could be heavy. That's a problem with many rivers and streams now in flood. Models have come down a bit on Sunday's rain totals, but still indicate some spots could see in excess of an inch, with locally higher totals. Highs in the north may hold in the upper 60s with clouds and rain cooled air. The south may squeeze out enough sunshine between raindrops to reach the mid 70s. Here's what models are suggesting for rain Sunday.

The EURO

The GFS

The 3k NAM

Memorial Day starts fine with morning sunshine. However, current models are a few hours faster with a NW flow disturbance that could generate some scattered showers and isolated storms in the afternoon. Thus, I have been forced to add a chance of rain to close out the holiday forecast. The north is most favored to see the wet weather. Before it would arrive, temperatures should reach about 70 north to 75 south.

Widely scattered showers could continue into Tuesday as we transition into a cool pattern with plenty of afternoon instability. Highs in some areas, may not get out of the 60s Tuesday and Wednesday. The pattern will certainly shut the door on severe weather potential for at least a week. Starting mid-week there is also a drier look to our weather with a pronounced NW flow and lack of moisture.

Alright then, I will wrap this up. Enjoy the holiday and the beautiful day that awaits you today. Roll weather...TS