000
FXUS63 KGRR 290040
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
740 PM EST Fri Feb 28 2020

LATEST UPDATE...
Aviation

.SYNOPSIS...
Issued at 209 PM EST Fri Feb 28 2020

- Flurries winding down this evening

- Warming trend for the weekend

- Below normal precipitation through next week

&&

.DISCUSSION...(This evening through next Friday)
Issued at 209 PM EST Fri Feb 28 2020

- Flurries winding down this evening

Radar trends show the snow showers and flurries diminishing. The
models had earlier shown a potential surge in the action
tonight associated with a surface trough dropping down from the
north. Based on the recent trends this looks unlikely to happen.
We will hold onto relatively low pops into the evening but drop
them off after midnight. Satellite trends also show the clouds
breaking up somewhat. We have lowered the cloud cover somewhat to
reflect the trend seen on satellite.

- Warming trend for the weekend then above normal into mid week

Deeper warm air advection sets up later Saturday into Sunday. The
low level thermal ridge shifts through the CWA Sunday into Sunday
night. This should be when the mildest temperatures occur.
Temperature values at 925 mb within the ridge are shown to be 7 to
9 deg C. With some mixing...this should support temperatures
making a run at 50 degrees on Sunday. A thermal trough that moves
in from west into Tuesday lifts northeast into Ontario. So the
arctic air will stay north of the CWA leading to a period of above
normal temperatures...especially as we may see a fair amount of
sunshine. A general cool down is shown for the end of the week as
deeper cold air advection sets up over the Great Lakes Region in
response to a deepening east coast storm.

- Below normal precipitation through next week

Other than a brief surge of moisture from the Gulf on Sunday...the
main moisture transport stays off to the southeast of the CWA.
What this means is that any waves of low pressure that move in
will likely feature only light precipitation through the week.
This will support a period of below normal precipitation. The Gulf
is shown to be cut off for the end of the week so the dry spell
could persist into next weekend.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 741 PM EST Fri Feb 28 2020

VFR weather is expected the next 24 hours. Lake effect clouds and
some snow showers will gradually diminish tonight. The ongoing
snow across Western Lower Michigan is essentially flurries, so we
are not expecting a reduction of visibility. Ridging building in
tonight should gradually wind down snow showers and into Saturday
morning eliminate the ceilings with bases around 4000-5000ft.
Ceilings should lift to around 10,000ft for Saturday afternoon.

Winds will remain gusty this evening, through about midnight.
Overnight the winds should settle more into the 10-15 knot range.

&&

.MARINE...
Issued at 209 PM EST Fri Feb 28 2020

The pressure gradient remain relatively tight through tonight but
a ridge builds in from the west on Saturday. This ridge will act
to weaken the winds and shift them from the west northwest to the
south. The pressure gradient then tightens up for Sunday and we
may need small craft advisories for that period. Given the current
high wave action...gusty winds and cold temperatures...some
freezing spray is possible.


&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...Small Craft Advisory until 11 AM EST Saturday for LMZ844>849.

&&

$$

SYNOPSIS...MJS
DISCUSSION...MJS
AVIATION...Duke
MARINE...MJS

NWS GRR Office Area Forecast Discussion