.SHORT TERM (This evening through Saturday)...
Issued at 227 PM EDT Fri Jul 26 2024

Various satellite products show western wildfire smoke at minimal magnitude and most concentrated west of us over Illinois, near the base of an upper level trough. So, minimal obscuration is currently being observed. Trajectories and HRRR smoke model suggest minimal if any haziness will be observed through the short term period, as most of the smoke will be relegated to the polar jet at higher latitudes in Canada.

Diurnal cumulus will diminish this evening with loss of surface diabatic heating. Meanwhile, amplification of ridge of subtropical jet will result in increased cirrus coverage through tomorrow. With increased ridging will come slightly warmer temperatures, to about late July climatology (mid-upper 80s).

Some diurnal cumulus is again expected tomorrow. Richer moisture per IVT plots will hold to our southwest through the day tomorrow, though high-level moisture will increase downstream of Plains upper low, further enhancing cirrus coverage.

.LONG TERM (Saturday night through Friday)...
Issued at 227 PM EDT Fri Jul 26 2024

Saturday Night Through Tuesday.

Quiet weather is expected for the start of the long term period, but conditions are expected to become active through much of next week as ridging across the Ohio Valley breaks down and the pattern favors northwesterly flow as the ridge across the Rockies builds. Ahead of the northwesterly flow, rain chances begin to increase going into Sunday as a weak trough interacts with the moist airmass to bring scattered showers and a few thunderstorms Sunday afternoon. Isolated showers are expected to persist through early Monday with a fairly stagnant airmass in place but by Monday night the aforementioned northwesterly flow aloft will begin to dominate the weather pattern.

The first threat for ridge-riding thunderstorms will be Monday night into early Tuesday with fairly good model agreement in potential impacts to Indiana but with only marginal shear, not expecting a high severe threat with a strong cold pool looking unlikely. This may set the table though for potential flooding later into the week if successive storm complexes further impact the same area.

Wednesday Through Friday.

The next most likely potential for a storm complex will be Wednesday, but there remains quite a bit more model uncertainty as to whether this system would impact Indiana. This system is more likely to occur during the late afternoon through early evening hours which should allow for a more organized thunderstorm complex with much better shear and instability compared to the storms earlier in the week. This system if it ends up impacting Indiana has the potential for both damaging winds and isolated flooding.

There could be additional rounds of storms Thursday into Friday but this will all be dependent on how the mesoscale environment is impacted by the storms earlier in the week with low confidence on even the synoptic environment by Friday as models rapidly diverge.
What does look likely is between Friday and Sunday, a more organized upper level low should drop southeast from Canada with impacts to the general Great Lakes Region.

Confidence in temperatures towards the middle to end of next week begins to fall off with the general pattern favoring temperatures near 90, but overnight convection may leave cloud debris which could cause for some days to end up closer to 80.

.AVIATION (00Z TAF Issuance)...
Issued at 713 PM EDT Fri Jul 26 2024

Impacts: None

Discussion:

VFR conditions to continue through Saturday evening as central Indiana remains under the southwestern portions of broad surface high pressure aligned from the southern Great Lakes to the Jersey shore. SCT/BKN cirrus should stay mainly south/west of terminals through midday Saturday...before returning northeastward during the afternoon.

Generally east-northeast winds will be light if not variable tonight...before veering to more east-southeasterly flow Saturday morning albeit continued light.

IND WATCHES/WARNINGS/ADVISORIES
None.