Highs today were just 70-74. Dew points as low as the mid 30s in the area were the lowest since May 14!
Battle between the record heat with Southeastern ridge & record cold & blizzard conditions with Western trough will get underway late this weekend.
Lowlands of parts of the Rockies will see +12" snow. Up to 50" may fall at higher elevations in Montrana, Alberta & into Idaho.
Winds may reach +60 mph.
Here, our 90 Tuesday looks to be within 2 degrees of tying the all-time record high October temperature (West Lafayette 1879-present) of 92 set October 1, 1897.
The all-time highest daily low temperature for October is 70 set October 8, 1939 & October 6, 1941. I am forecasting a low of 70 on October 2 & 71 on October 3.
Eventually, the chill will move southeastward in two waves.
After 45-52 tonight with a slight rise late as clouds increase & winds go calm to southeast at 5-8 mph (as warm front approaches).
With increasing clouds & a couple isolated showers briefly Friday morning, a wave of showers/storms should pass generally in the 12 p.m. to 7 p.m. time frame from northwest/west to southeast/east. Heaviest storm action looks to be in north of Route 18.
There is a MARGINAL RISK of severe weather with main threat being hail. An isolated severe gust or brief tornado along the warm front cannot be ruled out.
Locally-heavy rainfall of +1" is possible from the heaviest cells.
As those showers/storms depart, a break will likely ensue as numerous storms with severe weather in a likely SLIGHT RISK zone should fire in northern Illinois to southeastern Iowa & northern Missouri.
Highs Friday will vary from 70-74 north to 83-86 south with warm front in the area.
I prefer around 79 at Lafayette, though Tippecanoe County highs may vary from 84 at Romney to 77 at Buck Creek.
Any slight shift in the warm front northward will bring the higher numbers farther northward.
Scattered showers & storms are likely Friday overnight to Saturday morning. Most of the storms will be weakening, but I cannot rule out an isolated severe storm.
As for Saturday, clouds & some sun will feature north-northeast winds north of the warm front & southeast to south winds along & south of it in the area.
Highs will vary from 74-84 north to south over the area with around 77 in Greater Lafayette.
A few showers are possible early in the morning, followed by a break, then a few isolated showers/t'showers giving way to a few spotty showers/storms by late afternoon evening.
Note how sudden storm projected along warm front late in the day goes severe.
It is not out of the question that one isolated storm does go severe given shear, as long as CAPE (instability) is sufficient.
A couple storms are possible Sunday, otherwise, it looks dry, windy, very warm to hot & humid Sunday-Wednesday with near/record warm highs & lows.
Rain & some storms are likely Wednesday evening-night to Thursday morning, followed by windy, cooler weather Thursday. Not Thursday night's low near 40 as skies clear & cold Canadian surface high comes in, causing winds to go calm.
Looks like October 3-12 will feature two surges of chill with lows in the 30s to 40s for multiple nights (two strong Canadian surface highs).
Surge of warmth is likely in mid-October with a risk of a round of some storminess, then a frost/freeze.
However, big surge of warmth should arrive late October & last to early November. Storminess & wetter than normal conditions should arrive.
Although first half of November looks cooler than normal, second half looks colder to much colder than normal with some very minor snowfall events before we turn mild as we move into December.