CheeselandSkies

The equinox was only a week ago, lol.

Primary severe threat with early next week system looks to remain southwest of the sub on Monday, with steep positive tilt mitigating things going into Tuesday, but it should bring a considerable amount of rain to a large area.

Oof.

Well, I am a chaser and I do love severe weather, but I advocate for restraint on social media hype unless/until there is actually good model agreement/consistency for a high-ceiling threat.

Every time Weed sees a trough on the models, he drives the social media hype train out of the station at full throttle, derails, crashes, and burns. I remain skeptical of this timeframe due to inconsistency between models/runs. Could it turn into something big? Sure, but IMO it's just as likely at this point to be a relatively modest event with a lot of rain/general thunderstorms and some isolated severe weather.

So when I got to work this morning the thermometer in my car said 27 degrees, and we had a stiff west-northwesterly breeze. 7-day forecasts from my employer and the NWS are rather depressing, with nothing outside of 40s and 50s. When's the flip back to much AA?

DMX with a great AFD write-up on all the potential impacts of the Sunday-Monday system including severe and synoptic winds. DVN/ARX seem purely concerned with snow despite the potential for the narrow instability sweet spot to set up at least partially in one of their CWAs.

SPC's highlight is much further south, but the 12Z NAM (and most antecedent GFS runs up to this point) would certainly support a severe/ threat in a narrow arc across eastern Iowa Monday afternoon. Those hodographs and 3CAPE are something else, if not for the antecedent Gulf drying, I really think we'd be staring down the barrel of another significant late March outbreak. The one thing I will say is that the surface low appears to be weakening with time on Monday; whereas last year March 31 it was deepening or at least holding steady. That might have mitigated the overall threat some in any case, but even so that's a pretty impressive profile despite the paltry on their face T/Td values. You only have to go back one more year (and in the very same state no less) to see what can happen when a setup like that overperforms.

Same.

We don't need no stinking METARs!

Based on what guidance, out of curiosity?

Some moisture issues to sort out, but quite a bit of potential there *if* things trend favorably.

Sounds like that would mean more chances, as well although of course the crucial specifics of any one setup are hard to pin down at this range. GFS has been less enthusiastic about the "open Gulf" idea, as it has been pretty consistently spinning up some sort of southern stream low in the Gulf that runs up the East coast, with its associated cold front plunging south and scouring out the moisture. However it could be completely out to lunch with this. Seen it lock onto a particular idea (such as formation of a TC in the western Caribbean) for something like 120-150 hours worth of runs only for it to not happen. Edit: The feature I talked about is still there in the incoming 00Z run. FH111, 1007mb coming into the Florida Big Bend and then runs up the coast, dewpoints get dropped to the 50s across most of the Gulf (even upper 40s along the Florida Panhandle coast).

Eight years ago today, a localized tornado outbreak occurred across central Illinois. Synoptically the setup was pretty classic with the left exit region of the midlevel jet squarely over the area and a deep surface low. However marginal/"just-in-time" moisture was an expected issue with dewpoints only reaching the mid-50's by go time. However with cold air aloft and the excellent kinematics, it was enough. Although, my chase partner and I thought our tornado chances were done for the day when we pulled into the Casey's gas station on IL-116 at the west edge of Hanna City, ahead of the "tail-end Charlie" cell on the next cluster of storms north of the one that would produce the tornado just west of Springfield around the same time. The storm wasn't looking that impressive on radar and our plan was to gas up, get snacks and drinks, and let the storm roll over us, sheltering his car under the gas station canopy if there was hail and then shoot lightning on the back side on the way home (I never uploaded any of the video from before the tornado encounter until now, I'd forgotten how electrified the storm already was at that point). It was at this point that several things happened in rapid succession. We felt a gust of warm inflow toward the storm still off to our immediate west (when, based on the prior radar presentation, we were expecting cool outflow), which should have been an "Oh s***!" moment but we just kind of shrugged it off "huh, that's interesting." What we didn't know was that the storm had just undergone a constructive cell merger. The radar updated to reveal, while not quite a classic hook on reflectivity, a definite RFD gust front curling back into an inflow notch, with an intense velocity couplet colocated with it, just off to our northwest! Both our cell phones alerted simultaneously with a WEA for a tornado warning, and the town's sirens blared to life! I'll let the video and its accompanying description tell the rest of the story... I'm conflicted about counting this as my first tornado, since we weren't 100% sure of it in real time, and it cannot be confirmed from my imagery alone due to the intervening tree line at the ground. NWS ILX surveyed a 7.1 mile path of up to EF2 damage from northwest of Trivoli to north of Hanna City that matches up with the time and direction of our view. This was one of three EF2 tornadoes to occur with the event; the best-known is probably the earlier one that occurred near Good Hope.

Yup...NAM tease. The lack of prior support from the globals was always a red flag, although one can hope.

Although, this year we've already had multiple events along/north of the IL-WI line starting in frickin' early February. It would be ironic if we started having issues with that now as we finally get into mid-March, on Daylight Time and close to the equinox.

12Z 3K doesn't have the WF getting much north of the IA/MO line, and rakes MO with supercells. Unfortunately that'd be out of range for me for a work-night chase.

Yup. Definitely would rather see the low intensifying with the mass response pulling the warm front northward or at least stationary.

Of course, right as they do that, the 06Z NAM (by far the strongest model supporting this solution) comes in with a less focused, strung out surface low.

Day 3 introduces slight risk for IA/IL/MO with hatched area. Supercells with "all hazards" possible per disco.

NWS Quad Cities not really sold, don't even mention the NAM solutions in their afternoon AFD. Just hail potential Wednesday night and mainly a rainfall event for Thursday.

Besides, on that plot posted above, moisture isn't even really a concern here. 500mb actually looked a little better on the 12Z, with what appears to be a negatively tilted shortwave swinging across the region at 00Z. Sent from my Pixel 4a using Tapatalk

Of course.

Scarcely a drop today, everything managed to miss just to the southeast. Looks like this next little batch coming up between Belleville and Fitchburg will, too.

Reds are outbounds, so in that case, winds blowing to the north. Could represent a surge of inflow. Generally when one color dominates like that it's either that or RFD depending on where the radar is.