284
FXUS63 KAPX 151503
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
1103 AM EDT Sun Sep 15 2024

.KEY MESSAGES...

- Rain-free weather and summer-like warmth persists through next
  week.

&&

.UPDATE...
Issued at 1103 AM EDT Sun Sep 15 2024

Synopsis: Deep layer anticyclone remains anchored over the northeast
quadrant of the CONUS...with southerly anticyclonic flow across the
upper Great Lakes.  Elongated hybrid (latent/dynamic) PV anomaly
across central Kansas/central Iowa/northwest Wisconsin/western Lake
Superior...with water vapor imagery showing several vorticity
centers along this axis.  Dry anticylonic trajectory into Lower
Michigan butting up against a ribbon of deep moisture that
originated with the remnants of TC "Francine"...an axis of
precipitable water at and above 1.25 inches from Missouri northward
across Wisconsin/Upper Michigan/northern Ontario.  This moisture
axis interacting with the upstream PV anomaly resulting in some
scattered showers across northeast Wisconsin/western Upper/Lake
Superior.  Pretty good east-west moisture gradient on either side of
Lake Michigan...12z APX sounding precipitable water 0.57 inch versus
1.46 at GRB.

Forecast Update:  Just some Ci around across northern Michigan at
late morning as early fog patches have burned off...and this is not
expected to change through the afternoon.  Vorticity center moving
into northeast Wisconsin this morning will track into central Upper
late today...which may kick off some convection not too far upstream
across western/central Upper with around 500-1000+J/kg MLCAPE this
afternoon.  Meanwhile...expecting dew points to mix down through the
50s this afternoon...and some 40s dew points across interior
northern Lower especially if we can mix a bit deeper than Saturday
(i.e., above 870mb). Speaking of which mixing to yesterdays PBL
depth yields a high around 82F off APX sounding...so a few record
highs in jeopardy including GLR (83/2015) and PLN (86/2004).

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 206 AM EDT Sun Sep 15 2024

Pattern Synopsis:

Expansive ridging will continue to dominate the pattern at large
east of the Rockies through the remainder of the weekend. Further
upstream, troughing will dig down the Pacific coast, further
reinforcing said ridging into next week. At the surface, weak
subsidence/little appreciable forcing aloft will keep high pressure
over New England and the Great Lakes through the end of the period.

Forecast Details:

Rain-free weather and warm temperatures persist -- As previous
forecaster discussed, largely a persistence forecast for
northern Michigan today and tonight with no appreciable airmass
change continuing the recent stretch of warm, dry weather across
the region. Forecast highs near 80 along the lakeshores and
low/mid 80s for interior areas are in store for this afternoon,
with localized readings in the upper 80s possible -- most
notably around the TVC area. Calm, clear conditions will once
again allow for efficient radiational cooling overnight,
dropping temperatures into the 50s for most areas tonight into
Monday morning. Typical low-lying cold spots could dip into the
upper 40s with patchy fog possible for some locations.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 206 AM EDT Sun Sep 15 2024

Pattern Synopsis/Forecast:

Troughing will continue to dig along the Pacific coast into early
next week, working to amplify downstream ridging east of the Rockies
and keep it in place through the duration of the period. Thus,
surface high pressure also largely appears to stay put through next
week -- increasing confidence in this extended stretch of summer-
like warmth and rain-free weather persisting into next weekend.
Highs in the upper 70s and 80s are expected each afternoon with
overnight lows ranging from the upper 40s into the 50s. As previous
long term forecaster discussed, warm and dry weather spanning this
long of a period brings about increasingly concerning fire weather
danger over the next 1-2 weeks. Fuels will continue to dry out over
the next week with the potential for minimum RHs dropping below 30
percent during the afternoon.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 630 AM EDT Sun Sep 15 2024

Patchy fog across portions of northern Michigan is expected to
dissipate over the next few hours as daytime mixing increases after
sunrise. Otherwise, VFR conditions are anticipated through this
evening. Light south winds between 5-10 mph will be in place today
with the potential for lake breeze formation to push inland from the
lakeshores this afternoon -- primarily along the Lake Michigan
shoreline. Mostly clear skies and weak/calm winds will once again
allow for efficient cooling and additional patchy fog development
tonight.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

UPDATE...JPB
SHORT TERM...DJC
LONG TERM...DJC
AVIATION...DJC