Lafayette, Minnesota Weather Forecast Discussion

482
FXUS63 KMPX 231722
AFDMPX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1222 PM CDT Tue Sep 23 2025
.KEY MESSAGES...
- Patchy dense fog continues this morning through 9-10am,
  burning off by late morning. Additional patchy dense fog is
  possible the next few nights.
- Quiet weather with temperatures in the 70s and lows in the 50s
  through the week and into the weekend.
&&
.DISCUSSION...
Issued at 252 AM CDT Tue Sep 23 2025
I`d like to start this AFD off with a brief apology, as last
night I had a poorly worded statement regarding the autumn
equinox that made it seem like it was in October instead of
yesterday. Sometimes these night shifts can make your brain say
one thing while your fingers say something completely different!
Regardless, now that we are post-equinox, we begin to lose
daylight even more rapidly as we move through the next couple of
months, but on the bright side it also means only 3 months
until we start getting that daylight back....
Nighttime microphysics satellite imagery shows a developing bank
of fog within portions of southeastern Minnesota, with already
dense fog over central Minnesota and northern Wisconsin within
proximity of Lake Superior. This is going to be a repeat
occurrence over the next few nights as we will have upper level
ridging and surface high pressure lingering, meaning light winds
and relatively clear skies allowing radiational cooling to
bring temperatures down to dew points every night. The same
pattern is expected to dominate through the rest of the week as
an upper level rough occludes over the Great Lakes, resulting in
northerly flow aloft and weak surface winds with the
precipitation shield around the low remaining over the eastern
Great Lakes and eastern coast of the US. This is evident with on
look through the forecast with PoP under 5% through the
entirety of the next 7 days, with the longer range outlook
looking just as favorable for an extension of September even as
we head into October. The one potential deviation from the dry
and quiet pattern would be late Friday into Saturday as a quick
moving trough sweeps across northern Minnesota, with the
position as of right now predicted to be too far north to give
anything but the northernmost counties any sort of shower
chances. Guidance is also split on just how far south it
reaches, with the ECMWF the only longer-range global model that
produces any measurable precipitation for the state while the
GFS/CFS show a much weaker trough that stays more to the north.
Ensemble guidance shows temperatures generally remaining in the
70s with little chances for precipitation over the next couple
weeks as the pattern remains unchanging. It is looking like the
beginning of October will pick up right where September leaves,
with continued 70s and relatively dry weather shown within the
Climate Prediction Center`s 6-10 and 8-14 day outlooks with a
large area of warmer than normal conditions dominating the
northern US including our entire area. This warm stretch may
delay peak fall colors, especially as overnight lows will also
be much warmer than normal. For some context, the longer range
GFS ensemble shows low temperatures in the upper 50s to low 60s
for the first week of October, compared to a normal of 47 on
October 1st down to 44 by the 8th. The coldest ensemble that
reaches this period is the CMC by far, however we still remain
5-10 degrees above normal for both lows and highs during this
stretch. Suffice to say, keep getting those outdoor late summer
activities in while this lasts as it looks to be a great period
of time to enjoy the weather before our inevitable drop towards
the colder temperatures of mid to late Fall and early Winter.
&&
.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1206 PM CDT Tue Sep 23 2025
Low stratus over southeast MN and west-central WI has been slow
to break apart again this morning. IFR/MVFR will continue for an
hour or 2 into this afternoon at RNH and EAU before conditions
improve to VFR. Elsewhere, VFR is expected through this evening.
Due to continued northeasterly flow off the Great Lakes,
widespread fog looks like a good possibility again Wednesday
morning. VLIFR conditions look most likely from central to
south-central MN and portions of western WI starting a few
hours before sunrise. Have gone aggressive with the dense fog at
the terminals in these locations due to the past 2 mornings.
Elsewhere, IFR to at best MVFR is expected. Conditions should
improve by late morning, but low stratus may struggle to clear
quickly as previous days. North-northeast winds near 5 knots
this afternoon slow to near calm tonight.
KMSP...VFR expected until early Wednesday morning as low stratus
continues to clear and cigs lift. Periods of IFR from fog and
low stratus are possible from 10-14Z Wednesday so have
maintained TEMPO from previous TAF. Winds will be northeasterly
near 5 knots the entire period.
/OUTLOOK FOR KMSP/
THU...VFR. Wind W 5-10 kts.
FRI...VFR. Wind S 5-10 kts.
SAT...VFR. Wind NW 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...TDH
AVIATION...CTG

NWS MPX Office Area Forecast Discussion