Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 201753

Area Forecast Discussion
National Weather Service Grand Rapids MI
153 PM EDT Tue Apr 20 2021


Issued at 152 PM EDT Tue Apr 20 2021

- Snow tonight as F-Gen Bands clip the SE

- Northerly Flow Brings Freeze tonight and Wednesday night


.DISCUSSION...(This evening through next Tuesday)
Issued at 152 PM EDT Tue Apr 20 2021

- Snow tonight as F-Gen Bands clip the SE

Surface low moves along strong baroclinic zone and surface cold
front aligned just south of Lower Michigan tonight. Strong F-gen
forcing will be across SE Lower Michigan and this is resulting in
mesoscale snow bands forming this afternoon and continuing
through the evening. Thermal profiles are cold enough for p type
to be all snow as the column saturates, even this afternoon with
sfc temps in the lower to mid 30s where it is snowing.

The area of strong f-gen translates east this evening and the snow
bands will follow. Expect the snow to exit the SE forecast area by
midnight. We tweaked amounts to be in the 1 to 2 inch range as
there will be some melting due to above freezing skin temps. There
could be some higher amounts if mesoscale bands are more intense
or pivot longer across our southeast zones, specifically Jackson

- Cold High Brings Freeze tonight and Wednesday night

Sharp upper trough and northerly flow will transport cold air
into Lower Michigan. Temperatures were in the lower to mid 20s
across our northern zones this morning and we expect them to be
about 5 degrees colder tonight, with some upper teens in the
colder spots. The airmass only modifies slightly before Wednesday
night. Widespread freeze both nights with several hours of sub-
freezing temperatures potentially doing significant damage to
fruit buds and blossoms.

Here are the record temperatures for lows tonight, highs Wednesday
and lows Thursday.

April 21st Record Low Temperatures:
Grand Rapids: 22 in 1953
Lansing: 15 in 1875
Muskegon: 23 in 2013
Kalamazoo: 20 in 1904

April 21st Record Low Maximum Temperatures:
Grand Rapids: 38 in 1936
Lansing: 40 in 1936
Muskegon: 38 in 2009
Kalamazoo:38 in 1893

April 22nd Record Low Temperatures:
Grand Rapids: 24 in 2020
Lansing: 21 in 1875
Muskegon: 22 in 1926
Kalamazoo: 22 in 1936


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 152 PM EDT Tue Apr 20 2021

Snow will bring IFR conditions across southern Lower Michigan
through the evening. VFR will continue north across central Lower
Michigan. Northwest winds will gust to 20 knots at times this
afternoon and again on Wednesday.


Issued at 152 PM EDT Tue Apr 20 2021

Expect winds and waves will remain below 25 knots and 4 feet the
next several days.


MI...Freeze Warning from 8 PM this evening to 11 AM EDT Thursday for



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