Another Fall Day then Warming

We have a cool morning with the temp at 48° at 6 am.  Yesterday’s high struggled to reach 63° here in Otsego after a morning low of 51°.  We had the jackets out for the first time since spring.  Sunrise is at 7:20 am and set at 7:56 pm.  By the 25th our day length will be 12 hours, equal to the length of the night.

We can expect a few showers moving through today with the temps reaching the 70° mark then fair weather will prevail through the rest of the week as high-pressure returns and temps return to above normal for this time of year.

We now have Typhoon MUIFA in the western Pacific. It is forecast to recurve into the northern stream Polar Jet by the end of this week. Typically about a week after that happens we get 3 to 5 days of cold weather (a Rossby wave interaction thing). This would suggest much cooler air by the end of next week. There is support on both the ECMWF and GFS for this to happen.

Forecast Discussion

-- Small Chances for Rain Today --

One more day in this stretch of the cool, mainly cloudy, and damp
conditions expected with the upper low today. The center of the
surface low is passing by just to our South early this morning,
while the center of the mid/upper low is just south of Toledo as of
07z.

What we are watching is the band of clouds and light showers that
extends from out over Lake Michigan west of Ludington, and in an arc
up through the Straits. This band will slowly rotate SSE through the
area today. The best chances of a few showers will be near the lake
where moisture flux off of the lake, and some instability from the
warmer lake will help to facilitate a few showers.

We will see this band gradually shift SSE through the day, with some
late day clearing taking place prior to sunset over the western
areas.

-- Mainly Dry and Increasingly Warmer through the Week --

Once the upper low complex over the region today moves out, we are
looking at another extended period of mild and dry weather.

One can tell that fall is on its way with the upper air pattern
becoming more amplified. That said, we will be under a drier and
mild area of the pattern with upper ridging to our west. This upper
ridge will only slowly advance toward the area through the rest of
this week as the mean upper trough axis remains over much of the
Western U.S..

The atmosphere will dry out after today, and stay that way with
little to no moisture advection taking place. Canadian high pressure
builds over the area on Wednesday, and then is slow to move out.
Weak short waves that eject out of the mean upper trough should go
far enough north to keep the area out of rain.

850 mb temperatures start out cool today sitting around 10C. That
supports highs in the mid 70s. These temperatures will increase to
around 17C by Friday, supporting highs in the 80s by that time.

-- Small Chances for Rain Next Weekend --

The overall pattern will see the upper ridge over the region try to
get knocked down some by better energy coming out of the upper
trough over the west. This will allow short wave energy to traverse
a little closer to the area, but generally still staying far enough
north to keep this area mostly dry. Only small chances for rain,
mainly north are possible.

Eventually, the western trough is expected to dig again, building
the upper ridge downstream of it once again. This will reinforce the
dry and warmer weather for Lower Michigan.