Coolest Day of the Week — The Michigan Weather Center

Yesterday we had a maximum temperature of 62° and a minimum of 43°. We’ve only had 15 days where no kind of precipitation fell here in Otsego this month. Total precipitation for the month is 5.75 inches and 8.19 inches of rain and sleet for the season totaling 11.98 inches for the year. Today will be much cooler than yesterday with temperatures remaining in southern and central Michigan, but only in the 30s in the north. Expect light rain showers from time to time, mainly in the afternoon. Wet snow can sometimes mix in north of Big Rapids.

Highs will be back to near normal by the weekend. Expect to see good sunshine from Thursday to Saturday. Our next storm system could bring showers by Sunday.

Forecast discussion

-- Showers Today --

Upper-level trough (closed low at 500 mb) and 850 cold air
advection will leave us prone to showers developing today,
reaching their peak in the afternoon with diurnal instability.
Fcst soundings from the HREF members show at least a 4000 ft thick
cumulus layer with tops -10 to -12 C. Wet bulb zero heights may
fall below 1000 feet AGL especially north of I-96 and late in the
day. As such, it would not be surprising to see graupel mixing
with rain in the heavier showers. Initially focused in western
portions of the area this morning, showers will become focused
farther inland, away from Lake Michigan, during diurnal max. Snow
flurries from lingering showers are possible tonight in central-
northern portions of Lower Mich.

-- Cold Today and Wednesday --

As was indicated for several days as a possibility by the GFS and
ECMWF, a pool of unseasonably cold low-level air that was over
western Ontario as of Monday evening will advect into Lower Mich
tonight. At 8 AM Wed, 850 mb air temperatures around -13C are
likely at APX and -11C at DTX. This would be enough for a daily
record low in their respective sounding climatologies since the
late 1940s. Some locations in mid-southwest Michigan may come
close to record lows Wednesday morning despite cloud cover and
wind/mixing, but ultimately might not break records as they are
competing with cold years prior to the sounding climatology and/or
nights with more substantial radiational surface cooling. The
small extent in area of the core of coldest air means very little
residence time in Lower Michigan, and 850 mb temperatures are
expected to moderate several degrees C by Wed afternoon, likely
keeping record cold highs out of reach. But credit where it`s due,
today and Wednesday will be among a handful of historically cold
April 26s and 27s in the last century. Given the late start to the
growing season, we do not expect frost/freeze headlines to be
necessary in our area.

-- Outlook --

The upper-air wave pattern in the region stalls out in the second
half of the week as the low becomes anchored over Maine/Nova
Scotia and the upstream ridge builds over the upper Midwest. This
would maintain surface high pressure in our area and a dry pattern
through Friday or Saturday. Temperatures will become gradually
warmer though stay mostly cooler than normal. Medium to low
confidence in the details of temperatures and precipitation Sunday
into early next week, as a low occludes over the Midwest and the
standing wave pattern over eastern North America starts to break
down.