Weather History – First 80 Degree Day – 4/24

Weather History

1980: Only two days after setting record highs in the 80s, a record snowfall blankets Lower Michigan. Grand Rapids sets a record for the date with 2.4 inches of snow, after hitting 86 degrees on the 22nd.

On April 24, 2005, a three-day snowstorm swept across Southeast Lower Michigan, dropping 16.5 inches of snow on NE Clarkston. The thumb reported drifts of 3-4 feet of snow. The storm began on the 23rd and lasted through the 25th.

Forecast Discussion

Early this morning we’ll see showers and a few thunderstorms mainly along US-10, otherwise dry and warm conditions are expected with cooler temperatures along lake Michigan. More widespread rain and thunderstorms are expected Friday before cooler and sunny conditions move in for the weekend.

- Dry Today

Upper-level ridging across the area will keep conditions dry. A cold
front across Wisconsin will drift south today, stalling this
afternoon near I96. South of the front, strong mixing and dry air
aloft will lead  to RH values falling into the 20s, leading to
elevated fire danger. RHs north of the front will be in the 30s to
low 40s. One mitigating factor for fire weather concerns will be
light winds. Weak gradient flow will keep winds at or below 10 mph
today. Dry conditions likely persist much of Thursday Night as well.

- Showers and Storms Friday

Precipitation chances increase Friday as a mid-level shortwave
drives a surface low across the state. A cold frontal boundary
associated with this low will drop south across the area, with
instability developing ahead of it. MUCAPE values ahead of the front
will increase to 1000-2000 J/kg bringing a thunder risk in the
afternoon and early evening. The best instability will be roughly
south and east of a South Haven to Mount Pleasant line. The threat
of severe weather is low, with insufficient deep layer shear (20-30
knots), but given ample instability only a modest increase in shear
could support convective organization.

- Dry Weekend With Shower/Storm Chances Tuesday

Northerly flow behind the front will lead to a cooldown for the
weekend, with advancing high pressure keeping conditions dry.
Forecast moisture profiles show plenty of dry air so ample sunshine
will be present.

Southerly flow will increase Monday and Tuesday as a low pressure
system advances into the region. Dewpoints climb into the 60s
leading to a broad warm sector across lower Michigan. A mid-level
wave will drive a cold front across the area Tuesday, though the
timing of this front is still uncertain. Ahead of this front, the
moist ambient airmass supports forecast MUCAPEs aoa 1500 J/kg.
Combined with forecast deep layer shear values in excess of 50
knots, the environment could be favorable for severe thunderstorms.
As expected at this range, mesoscale features remain uncertain.
However given the favorable synoptic setup for severe weather, close
evaluation of forecast trends will be needed in the coming days.