Indystorm

Central IL and IN are under marginal risk this Sat. evening with storms starting to fire in west central IL west of Springfield and Lincoln. Let's see what develops. Right now they are elevated on the north side of the front....Springfield 76/49 Salem 78/64 SPC not currently expecting to issue a watch due to sparse nature of convection, but damaging wind gusts and some hail may occur.

Yeah, public health emergency declared in all of Cass County because of this. Really making the news down here. Wondering what Gov. Holcomb will say Friday on his update regarding either extension of stay at home or limited reopening. And Simon had planned to reopen their malls on a limited basis starting this weekend.

I've only seen a confirmed EF 0 tornado that touched down in Dyer IN on May 27, 2019. A nearby theater was evacuated from that one and I saw the tornado to my west. Your story sounds too close for comfort.

But I remember following those long track supercells that hit on March 12, 2006 that produced two tornadoes in Springfield.

Nice shelf cloud

I might get a garden variety t storm around midnight or so down here in central IN. 72/51 here now this evening.

...Midwest... Strong large-scale forcing for ascent will spread into the mid-MS Valley region Tuesday afternoon as exit region of upper jet shifts across IA. Diffluent high-level flow should overspread this region which should aid scattered thunderstorms ahead of the front from MO, north to near the surface low. Latest short-range model guidance/CAMs are fairly aggressive in developing scattered deep convection, possibly supercellular, within an increasingly sheared regime. While low-level moisture is initially a bit dry, rapid boundary-layer moistening is expected across MO into IL ahead of the wind shift. This should allow substantial buoyancy to evolve that would support potentially organized supercells. Large hail, damaging winds, and a few tornadoes are possible with pre-frontal supercells.

Based on current Monday afternoon 3k NAM and HRRR if I were chasing Tuesday I would focus on late afternoon from west central IL to the Peoria region for possible tornadoes.

Hmm.....

The virus may have been present here for a much longer time in the general asymptomatic population than originally thought, as some reports have indicated. It may have more recently mutated to increase its potency and virulence among humans than was previously the case. It's sort of like reminding ourselves that wall clouds can be rather prevalent, but the majority of wall clouds do not produce tornadoes.

Right now SPC has a marginal risk on Tuesday April 28 for IL but says in the discussion that severe probs may need to be increased for the Midwest if instability increases in the area.

Surprise for April 25 here in sw IN Time Location County State Lat Lon Comments 1825 5 NNW MOUNT VERNON POSEY IN 3800 8792 LATE REPORT. BRIEF TOUCHDOWN NORTHWEST OF MOUNT VERNON NEAR COPPERLINE ROAD AND BASE ROAD INTERSECTION. (PAH)

Skilling mentioned this possible threat several days ago. Was concerned about the system's amplitude.

Noticed both of those things on Pivotal wx. Gonna get active, but the south or any part of the country doesn't need it particularly at this time.

MEG depicts the incongruity of this situation when they say that spotters will be needed Sunday while being sure to follow all CDC guidelines.

Read where Milwaukee originally had over 100 polling places for this election....now reduced to 5 because of shortage of staff. Inexusable attempt to take advantage of coronavirus to suppress the vote. Tremendously long lines.

I really can't believe from a public health perspective that Wisconsin is going ahead with this election tomorrow.

That is definitely the big scary news story here in the Indpls area this evening.

I think the guidelines are ten or less. We have even dispensed with board meetings for this period. I have a varied background. My major on my bachelor's degree from I.U. decades ago was public health education with a minor in earth science, and I eventually got training in theology and became a minister. Go figure.

Very sad to hear of this practice and theology. Our church has followed the governor's orders and halted public worship. We communicate with e mail including my sermons each week since we do not have live streaming and a fairly elderly congregation. We are United Methodist, and John Wesley's three simple rules were, First, do no harm. Do good, And stay in love with God. You can't be a witness when you are harming your neighbors by exposing them to a potentially deadly virus.

IND agrees with SPC currrent outlook. Tuesday the aforementioned upper wave will be moving off to the east and as the day commences a capping inversion will build over the area under weak upper ridging. Central Indiana will remain in the warm sector with a warm front to the north as a system approaches from the west. Some uncertainty regarding how long it will take the cap to break, how long earlier clouds from the Monday night rain and storms will take to move out, and the exact timing of the upper wave and front. However, shear with the incoming system is solid. Temperatures should reach into the 70s (and possibly upper 70s if skies clear out) and models show dewpoints climbing into the lower to middle 60s with southwesterly flow. If these features can come together, the potential for severe weather is there. Steep mid level lapse rates look to advect in over the area late in the day as well. Looking at all of the above and checking out forecast soundings, current thoughts are cap will hold most of the day and best chances for development of storms will be early evening into the night. Large hail and damaging winds the main threat at this time. SPC slight risk looks reasonable.

LOT still hanging its hat on the King for the Sunday AFD. Heading into the day on Tuesday, there could be some residual cloudiness/ACCAS, but expect temperatures to still manage to get up into the 70s across the area thanks to southwesterly flow at the surface advecting warm moist air into the region. The ECMWF continues to indicate highs in the upper 70s are possible, especially for our far southwestern zones. This will help set the stage for potential strong to perhaps severe storms Tuesday evening. The big question is whether there is enough forcing to break the strong capping inversion in place. Models are not consistent with timing and location of convective initiation, with many suggesting things develop after 00Z and farther to the southeast. The ECMWF has been consistently developing a line of convection across our NW by 21-22Z run after run, so cannot fully discount this. It is worth noting the ECMWF has a stronger 500mb speed max reaching the area prior to 00Z which could explain why convection is able to initiate prior to 00Z. With such a robust EML, it is possible that lower dewpoints could mix down to the surface, however, if there is sufficient clearing during the day, temps could reach into the mid to upper 70s which could provide sufficient surface destabilization to provide additional lift to overcome this. Given these uncertainties, thunderstorm coverage would likely be isolated/discrete. If storms are able to form, steep lapse rates exceeding 8C/km and MUCAPE over 2000+J/kg and sufficient shear suggest strong to severe thunderstorms would be possible if they are able to form. Will continue to evaluate as things get closer. A stronger cold front pushes through the area on Wednesday. Thunderstorm potential is highly dependent on how things ultimately evolve on Tuesday, but if the atmosphere is able to recover, there is a window for thunderstorm development again Wednesday evening, especially for areas south of I-80. If dewpoints struggle to get back into the 50s, thunderstorm development may be limited.

As with 3/28 I think the issue will be how far north the WF gets and how high the dews progress geographically. Our surface temps here in IN have been slow to reach max guidance the past couple of days, but I see what you are talking about, Brandon, on the models.

From Chicago discussion this Sat, concerning Tuesday evening. Aforementioned set-up with temps in 70s and around 60/lower 60s dew points could yield moderate instability of 1000-2000 j/kg MLCAPE. This is concerning as strengthening northwest flow aloft with approaching wave later in the day/early evening may support 40-50+ kt of deep layer bulk shear and a strongly veering profile. This period will be one to watch for northwest flow strong to severe thunderstorm risk Tuesday PM. The above described wind profiles would potentially be supportive of supercells with a large to very large hail risk given steep lapse rates and large CAPE in hail growth zone. Steep low level lapse rates may also develop, posing a threat for damaging downburst winds. Looming uncertainty with this threat pertains to the potential for EML capping to hold if there is less insolation and/or forcing and frontal convergence is not enough to erode the MLCINh. ECMWF has been most consistent in favoring convective initiation, with GFS more capped, though ECMWF does have solid ensemble support including from GEFS. Capped PoPs in mid to high chance range due to uncertainty, and did add some 3-hourly temporal detail to PoPs Tuesday afternoon.