After areas of fog & lows of 64-69 this morning, the clouds have been slow to break up appreciably so far today. So, as of 1 p.m., temperatures are 78-83, but dew points are high at 70-76, so it is quite muggy to oppressive out. As I type this, our WLFI ob site shows a temperature of 80 with a dew point of 75!
Nonetheless, I'll trim highs back from 83-88 to 81-86, but the 70s dew points will make it feel oppressive with 86-92 heat indices.
MARGINAL RISK for severe weather up for the entire viewing area this afternoon-evening for an isolated severe storm or two.
Projected sounding for Greater Lafayette via the 3 km NAM model shows increasing & mid & upper flow, but a lack of appreciable CAPE (much of it a bit elevated & then the rest concentrated in the tropical air near the surface) with so much cloudiness & less than ideal lapse rates, precludes higher severe risk.
Low-level jet does nose in & increase this evening to part of tonight, however.
So, still MARGINAL RISK seems reasonable.
Showers & storms will move in & pass later this afternoon-evening & into tonight.
I kept 25% POPs in forecast for tomorrow for our southeastern counties, but most of the rainfall will stay south & southeast of our area. It largely looks partly to mostly cloudy with highs in the 82-87 range with high humidity & a light south wind.
Much of the storm action Thursday will be south & southeast of our area, but strong surface cold front in the evening may pop a narrow, broken line of storms.
Otherwise, it looks like a very warm, humid day with partly cloudy skies & highs 84-88 with southwest to west-southwest winds at 10-20 mph.
What will be the big driver of the big cool-down after September 10 will be the two typhoons in the Pacific moving toward Siberia, merging with an upper trough & forming a big extratropical storm. This very deep system means a very deep trough being carved out in that region.
This will, in-turn, develop massive hot, dry upper ridge downstream from parts of Alaska & British Columbia to the Far West in the U.S. This will then drive deep trough with cool air into the central & eastern U.S. Wildfire danger from Santa Ana & Diablo Winds in California will be extremely high.
This pattern, with very active Atlantic with tropical activity, will tend to pull hurricanes toward the Florida Peninsula to Carolinas, rather than the Gulf Coast.
We may have a big hurricane impact South &/or North Carolina in this cool period.