Constantine, Michigan Weather Forecast Discussion

795
FXUS63 KIWX 291820
AFDIWX
Area Forecast Discussion
National Weather Service Northern Indiana
220 PM EDT Mon Sep 29 2025
.KEY MESSAGES...
- Much above normal temperatures to continue on Tuesday with highs
  in the low to mid 80s.
- Cooling slightly for Wednesday and Thursday but high
  temperatures are expected back into the lower to middle 80s
  for Friday into the weekend.
- Dry weather continues through the remainder of the week.
&&
.DISCUSSION...
Issued at 219 PM EDT Mon Sep 29 2025
Very few changes made to the previous forecast with an extended
period of above normal temperatures and dry conditions expected. An
omega-block pattern continues across the central CONUS with little
movement in the upper ridge axis position expected through the
middle of the week. Some slight change in the orientation of the
upper ridge axis is expected later Tuesday into Wednesday as several
short waves top the ridge across south central Canada while at the
same time a stronger upper vort max digs southeast across southeast
Canada. This evolution will allow for some backdoor cool advection
via some strengthening of the east-northeast low level flow.
Slightly cooler low level thermal profiles should shave a few
degrees off high temperatures over the next few days, especially by
Wednesday and Thursday as some increase in high level cloudiness is
also expected with some elevated moisture spilling over the ridge.
A cut-off upper level vort max across the southern Plains today will
gradually get ingested into Corn Belt later Tuesday night and will
eventually shear across western/southern Great Lakes late Thursday
into Friday. Some weak 850 mb moisture return should precede this
dampening wave, but any low probability of an isolated shower should
remain well west/southwest of the local area late this work week.
By Friday night, low level ridge axis should make enough eastward
progress to allow a south/southwest low level flow regime to set up
for the weekend. These south/southwest winds will result in some
weak low level warm advection and moderation of highs back into the
lower to middle 80s for the weekend. However, low level flow
trajectories will not be supportive of significant moisture
transport as far north as the southern Great Lakes region. Some
indications in medium range guidance persist regarding a lead short
wave lifting across the Upper Midwest Saturday night, but given lack
of moisture return and possibility that western periphery of the low
level anticyclone may maintain influence across the local area, no
mentionable PoPs are included over the weekend. There has been a
dprog/DT trend of a less phased northern/southern stream heading
into early next week resulting in more of a cut-off negative upper
height anomaly across western CONUS and less southward penetration
of a low level baroclinic zone with the northern stream trough.
Given large amounts of background anticyclonic shear across the
northern tier of CONUS, this idea of less phased, positively tilted
systems seems to make sense and thus will hold off of any
mentionable PoPs through the remainder of the long term period with
continued above normal temperatures.
&&
.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 135 PM EDT Mon Sep 29 2025
VFR conditions expected through the remainder of the TAF period.
Some diurnal cumulus has developed but will begin to diminish
after sunset. Otherwise, light north to northeasterly winds less
than 10kts for both TAF sites through the period.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Marsili
AVIATION...Andersen

NWS IWX Office Area Forecast Discussion