643
FXUS63 KIWX 021806
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
206 PM EDT Sat Aug 2 2025

.KEY MESSAGES...

- Seasonably cool today with highs in the mid to upper 70s.

- Turning slightly warmer into early next week with the highs
  warming into the lower 80s Monday.

- Dry weather with mainly light winds through Tuesday morning.
  There is some possibility of the dry weather continuing into
  early the following week (the week of 8/11).

&&

.DISCUSSION...
Issued at 204 PM EDT Sat Aug 2 2025

Surface high pressure is overhead today and Sunday and then slides
east of the area by Monday morning. During this time, east winds
will help keep the area dry and devoid of precip and 850 mb temps
increase from just below 10C to around 14C allowing coverage of 80
degree max temps to increase from none to a few to numerous.

What a couple days ago started as a precip chance for Monday in the
NBM has since disappeared. A theta-e plume attempts to scrape our
southern and southwest 1 tier of counties Monday and Tuesday as a
trough develops out in front of a shortwave ejecting eastward from
the Plains. The GFS and NAM have a relative warm/moist bias and so
am inclined to lean towards the drier ECMWF, especially when
considering that we will have had multiple days of dry east winds
that will need to be overcome by arriving moist air despite whatever
moisture is caused by plant evapotranspiration. While there is a
very small chance something attempts to work in by Tuesday
afternoon, rain likely waits until mid to late week to get into the
area at the earliest as that`s when winds gain more of a southerly
wind component to get into the better airmass. At the same time,
we`re now on the backside of the trough so getting better lift may
be an issue and we`re likely relying on convective temps and
breaking caps instead. At the same time, it is interesting that the
LREF through DESI shows less than 20% chance of achieving 0.05 inch
rain in the latter half of the week. It has better chances before
mid week.

If we do have to wait until after the work week for our next chance
for rain, it may take until Sunday or Monday of next week as the
pattern switches to the southeast high and the southwest high gives
way to a trough in the west. This allows a better moisture stream in
from the Gulf and we get a cold front for better forcing.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1221 PM EDT Sat Aug 2 2025

VFR this period and beyond as sfc ridging dominates across the
Great Lakes.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Air Quality Alert until midnight EDT /11 PM CDT/ Sunday night
     for INZ005>009-012>015-017-018-022>027-032>034-103-104-
     116-203-204-216.
OH...None.
MI...Air Quality Alert until midnight EDT Sunday night for
     MIZ078>081-177-277.
MARINE...None.

&&

$$

DISCUSSION...Roller
AVIATION...T