FXUS63 KIWX 051708

AFDIWX



Area Forecast Discussion

National Weather Service Northern Indiana

108 PM EDT Wed Aug 5 2026



.KEY MESSAGES...



- Dry conditions through late afternoon with seasonable highs in

  the 80s.



- Chances (30-70 percent) for showers and storms this evening

  and persist at times into Friday. Locally heavy rain is 

  possible.



- Low chances for showers and storms Saturday into Tuesday (20-40

  percent).



&&



.DISCUSSION...

Issued at 206 AM EDT Wed Aug 5 2026



Overall upper level pattern is transitioning to a longwave

trough which will settle in for the next several days. A series

of waves will pass through with timing and strength differences

causing challenges on precip chances into at least Thursday

night. A weak cold front extended from northern Lower MI to

eastern IA. This feature will edge ever so slowly east with each

impulse and a modest LLJ allowing for areas of storms to 

develop and move N and E. The current area of showers and storms

will attempt to edge east over the next several hours, but 

should weaken as it outruns the 20 to 30 kt LLJ as well as 

better forcing. A somewhat stronger trough will intersect the 

frontal boundary, allowing for a strengthening LLJ with 

redevelopment of convection expected during the day over eastern

IA. The LLJ and eastern movement of the trough will allow some 

chance for this precip to make it into far W/NW areas late this 

afternoon and moreso this evening but it will fight to make it 

very far east as the front slows further. Have attempted to slow

arrival this afternoon and focus highest (likely) pops in W/NW 

areas this evening before the overall area likely weakens. 

Thereafter running with slgt chc to chc pops given the front 

slowly edging into the CWA and stalling/washing out with time. 

Models vary on degree of potential redevelopment during the day 

Thursday, but with plenty of moisture and limited CAPE at least 

mid to high chc pops warranted with possibility for higher pops

needed depending on overnight convection impacts. High PWATs 

will bring a threat for heavy rainfall with the greatest 

concerns existing where repeated convection occurs. 



No sig changes beyond Thurs given challenges for overall timing

and impacts from additional waves as the upper level trough

remains in place into early next week. The main focus for

greater heat will remain over the 4 Corners area through the

weekend with a somewhat more zonal flow beginning to set up next

week which may allow some of this to move in.



&&



.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...

Issued at 108 PM EDT Wed Aug 5 2026



A tale of two TAFs this afternoon: one-liner at KFWA while KSBN

faces episodes of -SHRA. 



Preexisting high pressure still exerts some influence over 

eastern Indiana, as evidenced by dew points in the low-60s. 

Modest low pressure of 1016mb over far northern Lower Michigan 

is struggling to exert its trailing precipitation shield 

eastward. A much better organized area of -SHRA is noted over 

far western Illinois and guidance has a fair handle on this, 

bringing it toward KSBN near 00z. Time height cross sections 

depict modest forcing through the column which bolsters 

confidence in -SHRA there.



As upper-level forcing lingers, but remains modest, a second

period of rain is probable near 12z. At FWA, lingering dry air

below 10k FT and poor forcing on time-heights really diminishes

any confidence in showers there. As a result, the inherited dry

TAF continues. Perhaps a better opportunity for -SHRA just 

beyond 18z. 



&&



.IWX WATCHES/WARNINGS/ADVISORIES...

IN...None.

OH...None.

MI...None.

MARINE...None.



&&



$$



DISCUSSION...Fisher

AVIATION...Brown