It was a cooler, but pleasant day with highs of 63-73. We are cooling off rapidly tonight as front (which was starting to work back northward), is pushed southward once again by surface high moving into central Michigan.
Temperatures are already largely 48-53 as of 11 p.m. (57 Covington near front). The temperature profile is indicative of the seasonal change that you see in spring, as well. Cold/warmth migration of the seasons tends to follow the 4 Indiana climate zones. For example, it is 47 at Grissom Air Reserve Base, but 71 at Evansville right now! The afternoon HIGH today at Fort Wayne was a mere 56, but 86 at Evansville. This tight gradient is a factor in severe weather, but also the fall color gradient over the state & the gradient you see in spring with the budding/blossoming trees. I have seen redbuds & flowering dogwoods in blossom in Evansville & Peru look brown like February at the same time in spring.
We will drop into the lower to middle 40s with upper 40s in the far southwest tonight with patchy fog potential.
After cool, damp 40s Wednesday morning, we will rise to 74-81 across the area Wednesday as front lifts back northward. Despite the front moving through, skies look mostly sunny.
Scattered showers & t’storms are likely the early half of Thursday, followed by a break. Then, widespread rain/t’storms are likely Thursday night-Friday morning.
Dynamics/shear/height falls/strong surface cold front/forcing all point to an organized severe squall line. HOWEVER, hindrance is just a bit of lacking in the instability forecast. If there was just a bit more buoyancy/surface instability expected, severe threat would be no-brainer as surface low deepens to an impressive 984 mb over far northern Wisconsin.
A windy fall system, it is strong, but unless it can become a hair more unstable, then this will be a gusty system with wind-driven rain/t’storms embedded in a large northeastward-moving band/mass Thursday night-Friday morning (after that scattered rainfall Thursday).
This will need to be monitored. Just perhaps a bit more instability into our area would make us cross a threshold & support severe threat that is definite west & southwest of here. Looking at these impressive wind parameters at all levels, IT IS CONCEIVABLE that severe threat could be expanded by tomorrow into our area.
Locally-heavy rainfall of 1-2″ still looks likely in the area.
After morning rainfall, Friday looks like a windy day with gusts perhaps to 37 mph. There may be a dry slot for a while during the day with sun, but stratocumulus/cumulus will likely pivot in after this, turning skies mostly cloudy.
After 63 in the morning, we may get to 66, but then fall in the afternoon into the 50s, it appears.
After 30s Friday night (models have freezing line into north-central Illinois…….wind may prevent frost here…….will watch), Saturday looks gusty & cool with strong northwest winds cranking up to gusts of 30 mph with highs in the 50s.
After 30s Saturday night with frost (lows 32-37), flow turns to southwest Sunday with a rebound to the 60s. An Alberta Clipper Monday may bring a few showers, perhaps even an isolated t’storm or two, with highs in the 60s.
Looks like a push of cooler air Tuesday with highs at 55-60 with 30s (& frost) Tuesday night & 60s Wednesday.
Right now, it appears as if storm system will pass over area with periodic showers/t’storms next Thursday-Friday.
Looks like we may be on warm side of system with 70 or 70s with southerly flow. Exact storm track will dictate the temperatures & whether there is severe potential. We these dynamic fall systems & battle of the seasons, we are getting into that severe mode that sees uptick in fall after lulling for a good 1.5-2 months.
SATURDAY, OCTOBER 11-THURSDAY OCTOBER 16………..
After potential 70s Friday with storms, the coldest air of the season will blast in on strong northwest winds around October 11. The highs may only run 47-54 with freeze possible on multiple occasions October 12-16.
Only issue with better timing of freezes will be that little shortwaves will be pivoting around upper low to our north that will be slow to exit.
This pattern may keep sky filled with a lot of stratocumulus/cumulus during the days with spotty diurnal showers & 40s & 50s. At night, with variable clearing & some fog, it is again likely that reaching 32 or less may occur multiple times.
This looks like a pretty chilly period of weather for us with temperatures below normal & considerable cloudiness, especially at peak heating. With looks northwesterly & quite brisk each day.
FRIDAY, OCTOBER 17-MONDAY, OCTOBER 20……………..
There are signs of warmer, sunny weather during this time period. With the chilly weather & frost/freezing prior, trees should really be changing color & peak color will be within reach.
Widespread 60s to perhaps 70 are possible at this time.
At the moment, there are subtle trends of storminess in this period (showers/storms). Temperatures are a bit nebulous, but warmth with lots of wind, followed by rain/storms & cool-down with freezing temperatures at night seems reasonable.