Clouds Increase – Weather History 4/30

We close out the month of April with clouds on the increase today with highs in the low to mid 60s. A much-needed soaking rain will move in tonight through Thursday.  A half to an inch of rain will fall.

In Otsego, our total rainfall is 3.56 inches in April and 7.57 inches in the March/April timeframe.

Weather History

1962: Several tornadoes struck southern Lower Michigan. A fire station was damaged in Lansing, and a building was destroyed in Grand Ledge. Another tornado struck south of Ypsilanti, destroying a barn and damaging two houses.

On April 30, 1962, 2 simultaneous F1 tornadoes hit Washtenaw County at 6:00 pm.

On a dry weather note, the date concluded one of the driest (4th) Aprils on record in 2004 when just 0.69″ of precipitation fell (0.70″ at Flint made April 2004 the second driest on record). One has to look back nearly a century to find a drier April (0.66″-1915) in Detroit.

Forecast Discussion

- Frost and Freeze This morning

Temperatures currently remain in the low 40s with dewpoints in
the mid to upper 30s along and south of the I 96 corridor. RH`s
remain 70 percent or above and winds have just begun to decouple
and go calm along the I 94 corridor southward. With dew points
above freezing, and winds not calm, it will become difficult for
frost to form, and for temperatures to go below freezing. Latest
soundings show the low levels continue to mix a little bit down to
the surface which is aiding the winds. Patchy frost formation can
typically occur once temps get 37 and below.
 Another issue is seen in satellite as a cirrus shield overspreads
the region from the southwest. The eastern sites south of the I 96
corridor having dewpoints closer to freezing thus have more frost
potential.

That said, there remains about 4 hours for temperatures to drop
to freezing. Winds should go calm just before sunrise and allow
for freezing temperatures through the north and areas of frost
elsewhere.

- Showers and Storms Wed Night into early Friday

 Echoes of the cold aside, the weak high pressure will give way to
a northeastward trough trekking its way through the southern
Plains. Gulf moisture will accompany this system bringing a
persistent period of rainfall. Latest NAEFS mean PWATS are upwards
of 1.25 inches that are +2 to +3 anomalies. The mid to sfc low
will intensify as it moves overhead with thunderstorms possible
Thursday. These storms will be fueled due to low level shear
intensification coupled with warm air advection out ahead of a
mid level closed low and a tightening gradient over southern
lower Michigan.
 Highest rainfall currently is a strip from around Lansing
extending to the southwest. However, given convection this could
shift and change. Overall QPF will vary from over three quarters
of an inch to upwards of 1.5 inches in and around thunderstorms.
Locally higher amounts are possible. Precipitation could linger
into the first half of Thursday night on the back side of the low
as it exits to the northeast.

- Slightly cooler this weekend with a warm up next week

 A deepening trough will move through Friday into Saturday will
cooler drier air filtering into the area. Temps will drop with
lows near freezing early Saturday morning. Max temps will be
around normal but will feel cooler with brisk northwesterly flow.
Patterns begin to diverge so a lack of confidence in long term
but overall warmer temperatures will return early next week.