Rolling Prairie Indiana Weather Forecast Discussion

819
FXUS63 KIWX 082323
AFDIWX
Area Forecast Discussion
National Weather Service Northern Indiana
723 PM EDT Wed Oct 8 2025
.KEY MESSAGES...
- Areas of frost Thursday and Friday morning.
- Temperatures warm back to near or slightly above normal this
  weekend into next week.
- Rain will remain sparse through the next 7 days.
&&
.DISCUSSION...
Issued at 216 PM EDT Wed Oct 8 2025
High pressure over WI this afternoon shifts east through time,
bringing back-to-back crisp and frosty nights. With low pressure
well off the northeast US coast, confidence is high in light wind
overnight and clear skies. Current forecast lows are on the
colder side of guidance, which, given this pattern change,
placement of the surface high, and 850mb temperatures of 2C to
4C, aiming to the cold side of guidance appears warranted. As a
result, have opted for an area-wide frost advisory. The argument
could be made that some northwest OH counties and Indiana
counties south of US 24 may not have a long enough duration of
36F, but this seems to be splitting hairs in the grand scheme.
Advisories will need to be considered again for Friday morning.
Return, southerly flow, takes place Friday but is at odds with
falling heights aloft ahead of an incoming low. This low deepens and
races across Michigan Saturday. This upper-level low is moisture
starved given its  continental polar source region. However,
guidance has been trending wetter these past couple of days as
solutions have become more amplified. Not a washout for our area,
but at least northern potions of the forecast area have a 20% chance
of showers Friday night and Saturday.
Upper-level ridging resumes in the wake of this low. High
temperatures will return to the 70s. Prospects for rain next week
remain murky and dependent on the placement and magnitude of this
upper-level ridge taking shape. In the meantime, in-house blend has
spurious slight-chance POPs near the lake.
&&
.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1229 PM EDT Wed Oct 8 2025
As high pressure slides by to the north, north winds and clear skies
will provide VFR conditions through the TAF period. LAV guidance
has cross-over temperatures that are not conducive to creating
fog. Slightly lower temperatures, as can happen in these
radiational cooling setups, could create fog, but it would
likely only create shallow fog at best given forecast sounding
shape. As such will keep these TAFs in VFR. Clear skies and
mixing would normally create a gusty day, but a weak gradient
underneath the surface high weakens the low level jet so
sustained winds should stay below 10 kts. North winds become
more easterly late tonight or early Thursday morning.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Frost Advisory from 4 AM EDT /3 AM CDT/ to 9 AM EDT /8 AM CDT/
     Thursday for INZ005>009-012>015-017-018-020-022>027-
     032>034-103-104-116-203-204-216.
OH...Frost Advisory from 4 AM to 9 AM EDT Thursday for OHZ001-002-
     004-005-015-016-024-025.
MI...Frost Advisory from 4 AM to 9 AM EDT Thursday for MIZ078>081-
     177-277.
MARINE...None.
&&
$$
DISCUSSION...Brown
AVIATION...Roller

NWS IWX Office Area Forecast Discussion