Weekend Forecast – 5/9

We have a string of beautiful days in store with highs in the mid-60s to 70s and 80s moving into next week.  Our next good chance of rain comes next Tuesday.

Weather History

1923: A very late-season winter storm dropped up to a foot of snow across Lower Michigan. Records were set for May snowfall at many places, including Lansing with 11.5 inches, Grand Rapids with 5.5 inches, and Detroit with 6 inches.

1927: About 40 farm buildings are damaged or destroyed as a tornado moved from near Loomis in Isabella County, across southeast Clare County, and into Gladwin County. Another tornado destroyed two barns and damaged two homes three miles west of Walker.

On May 9, 1923, a late-season snowstorm pounded Southeast Michigan. Six inches of snow was recorded in Detroit, with areas around Flint and Saginaw receiving around a foot! Widespread damage was also reported with trees and power lines snapping under the heavy, wet snow.

Also on May 9, 2000, Plymouth received 1.75-inch hail at 7:05 pm and then had winds at 69 mph at 7:33 pm, which resulted in $135,000 in property damage.

Forecast Discussion

- Dry and Mostly Sunny Through Monday, Slight Chance of Showers
  Saturday

High pressure will be largely over the region with mostly clear
skies and warming temperatures through the weekend, though
interrupted by a weak cold front on Saturday. Going with a slight
chance of showers on Saturday... Models show a moist layer in the
mid levels above the PBL, around 5,000 to 10,000 feet, which may
be within a shallow conditionally unstable layer. As a result,
a few higher-based, lower-topped showers could develop with enough
rain that could survive the trip through drier air closer to the
ground.

- Chances for Thunderstorms Middle to Late Next Week

Better moisture arrives Tuesday and sticks around for a few days.
The NBM has dew points reaching the lower 60s. Average CAPE
values among the ENS, GEFS, and CMC ensembles increase from
Tuesday into Thursday or Friday, with a majority of members
producing rain at some point during that time frame.

Early next week, there is likely a split upper-level jet across
the central US, with a broad ridge in the northern stream, and a
cutoff low the southern US / Gulf region, forming a Rex block type
of pattern. For Tuesday-Wednesday, the southern low should slowly
migrate toward the Ohio Valley or southern Great Lakes. Scattered
showers and thunderstorms should develop as a result, with a
tendency for them to be more diurnally driven (occurring mostly
during the afternoon). Wind shear appears rather weak, as do mid-
level lapse rates. This should limit severe weather potential.
Instead, deep moisture through the convective layer and slow-
moving cells would favor localized downpours and highly variable
rainfall totals.

For Thursday-Friday, a deeper upper-level trough from the Dakotas
approaches the western Great Lakes. Stronger surface fronts are
expected, along with the potential for steeper mid-level lapse
rates and increasing shear. This time frame would have some
possibility for severe storms if this were to verify. It`s still a
week away, though confidence is a little higher than usual given
low spread in the ensembles regarding the synoptic pattern
evolution.