Harrietta, Michigan Weather Forecast Discussion

871
FXUS63 KAPX 211800
AFDAPX
Area Forecast Discussion
National Weather Service Gaylord MI
200 PM EDT Sun Sep 21 2025
.KEY MESSAGES...
- Scattered showers and storms at times through early this week.
- Fog potential tonight and again Monday night. Fog could be locally
  dense in spots with significantly reduced visibilities.
- Seasonable temperatures through much of this week; watching
  potential system late week.
&&
.SHORT TERM /THROUGH MONDAY/...
Issued at 156 PM EDT Sun Sep 21 2025
Pattern Synopsis/Forecast: Trough axis upstream continues to slowly
trek east this afternoon through early/midweek. Height falls remain
the rule locally with continued abundant moisture and embedded
shortwave progged to move through this afternoon/evening. 80+ kt jet
streak aloft noses into the region this evening/tonight. All of this
combining to result in additional scattered shower/storm development
through at least Monday.
Forecast Details: Showers continue to percolate across parts of
northern Michigan this afternoon. Little change anticipated in
this through the remainder of the afternoon and evening given
continued support aloft and abundant moisture with PWs nearing
1.4" -- a value that`s +1 to 2 SD above the late September
climatological mean. While unlikely, if any storms are able to
materialize, they`ll be capable of producing locally heavy
downpours.
May be general lull in coverage of precip activity later
this afternoon into tonight with shower/storm chances
increasing again during the day Monday with somewhat better
coverage expected to return Monday afternoon/evening. This
timeframe also one to watch for some locally heavy rainers and
potentially a bit more instability to work with for a potential
strong storm or two.
Potential fog development tonight looks increasingly likely across
parts of northern Michigan given light/calm winds and added low-
level moisture post precip today-this evening. Fog could be dense in
spots with pretty widespread 30-60% probabilities (highest
across the eastern U.P.) for 1/4 mi or less visibilities
between 06-12z.
Mild temperatures tonight with lows largely in the 50s and low 60s.
Highs Monday expected to top out several degrees above normal for
many -- largely in the low-mid 70s. Perhaps some upper 70s toward
Saginaw Bay.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 156 PM EDT Sun Sep 21 2025
Day 2-3 (Monday night - Tuesday):
Upper troughing continues to slowly sag south and east Monday night -
Tuesday with continued shower/storm potential. Coverage looks
highest Tuesday afternoon aided by diurnal processes -- another time
frame where chances for a stronger storm or two look to be non-zero
given potentially for diurnally driven instability and a modestly
sheared environment. Pws look to remain over an inch in most places
Tuesday, also yielding a continued heavy downpour threat under any
convection.
Fog potential exists again Monday night with 

NWS APX Office Area Forecast Discussion