Weather History – Showers 4/23

Weather History

1968: A tornado struck Big Rapids in Mecosta County, injuring 11 people and doing half a million dollars in damage as it covered a path 10 miles long.

1986: Freezing weather prevails across Lower Michigan. Record cold temperatures for the date include the 19 degrees at Muskegon and 20 degrees at Grand Rapids which is also a record for coldest so late in the season.

On April 23, 1985, the daytime temperature rose to 85 degrees in Flint, which is the record high temperature for the day. Curiously enough, the very next year, in 1986, the overnight temperature dropped to 22 degrees, setting the record low temperature for this day!

Forecast Discussion

Late this afternoon and evening showers and storms are expected with the best chances north of I-96. Isolated stronger storms may produce hail and gusty winds. Thursday will provide a nice break before rain and storm chances return for Friday. Cooler temperatures are expected along the lake with 70s to low 80s inland.

- Several Chances of Showers/Storms Through Friday Night

Several chances for showers and storms exist over the next 72 hours.
The two best chances are later today into Thursday, and Thursday
Night into Friday.

Today, a weak frontal boundary is forecast to stall across the upper-
midwest. The arrival of a 700mb wave will be sufficient to force
thunderstorm development late today/tonight in conjunction with this
boundary. The best coverage is expected to be across northwestern
portions of our forecast area that are closer to surface convergence
and the mid-level wave. Isolated strong to severe storms cannot be
ruled out with steep lapse rates and effective shear of 25-30 knots,
mainly across our northwestern forecast area. Hail and gusty winds
are the concerns if any storms can organize.

Precipitation chances are notably higher, on the order of 70-90
percent, Thursday Night into Friday. Rain chances are due to a pair
of mid-level shortwaves driving a surface low through the area. The
best chance of thunder with this system comes Friday afternoon as a
few hundred joules of MUCAPE build across the southeastern forecast
area.

Surface and upper-level ridging then arrives for the weekend. This
will keep conditions dry across West Michigan.

- Warming Through Late Week

Above normal temperatures are expected the next several days, with
highs into the 70s today and some areas reaching the 80s Thursday.
For reference, normal highs this time of year are in the low sixties
in Grand Rapids. Temperatures then cool down Friday into Saturday,
albeit with temps still near to above normal, as northerly flow
takes hold.

- Warm With Shower/Storm Chances Tuesday

Warm air advection resumes early next week with 850mb temps climbing
into the mid teens Tuesday. This will bring plenty of warmth as
highs climb back into the upper 70s or 80s.

The overall synoptic pattern shows that a mid-level wave will drive
a cold front across the region. LREF members show an expansive
warm sector developing across the region, including lower
Michigan, with mean dewpoints in the lower 60s. With the
ECMWF/GFS showing sufficient deep layer shear, storms could be
stronger, though this outcome is uncertain. Cluster analysis shows
a split in when the shortwave and surface front arrive, with the
timing being key to whether stronger storms can occur. Tuesday
could be an active day, with refinement of the forecast expected
in the days to come.