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000 
FXUS63 KGRR 140220
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
920 PM EST Wed Nov 13 2019

LATEST UPDATE...
Update

.SYNOPSIS...
Issued at 248 PM EST Wed Nov 13 2019

- Lake Enhanced snow tonight Muskegon to Ludington

- No storms but remaining colder than normal into next week

&&

.UPDATE...
Issued at 912 PM EST Wed Nov 13 2019

We did lower the accumulations slightly in the winter weather
advisory area. Overall the light snow persists in the advisory
area. So far this event as featured mainly light snow and
accumulations...however more snow is forecasted to move in 
overnight. The latest HRRR is showing 1 to 2 additional inches of 
accumulation into Thursday morning. As a result we will keep the 
headline going but lower the values down to 2 to 4 inches.
Elsewhere around the area a dusting to perhaps an inch of snow is
predicted...which could lead to some localized slick spots on the
the roadways. 



&&

.DISCUSSION...(This evening through next Wednesday)
Issued at 315 PM EST Wed Nov 13 2019

No changes to the Winter Weather Advisory. Isentropic ascent is
expected to combine with modest lake effect banding to produce a
general 2 to 4 inch area of snow from Muskegon to Ludington from
late this afternoon to early morning Thursday.

Forecast and observed soundings show dry wedge being eroded this 
afternoon and the DGZ saturated near the top of the inversion 
around 5 to 6 kft, then again at mid levels where there is
isentropic ascent. So we expect about a six hour period from 
about 6 pm to midnight where enhanced snowfall rates are possible 
then winding down after midnight as the mid levels dry out and 
inversion heights lower.

Generally quiet and dry weather is expected from late Thursday 
into early next week as northwest flow continues with 
temperatures higher than the current record cold levels, but 
still below normal for mid November.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 613 PM EST Wed Nov 13 2019

The dry air in the low levels has limited the snow for the TAF
sites. However as we go through the evening the axis of deeper
moisture pivots east which will allow for the snow to move into
most TAF sites for a period. MVFR conditions are forecasted to
prevail once the snow moves in. Conditions could lower to IFR 
mainly for KMKG. The snow will pull away later tonight into
Thursday morning. Conditions will improve slowly from the west
during the day.


&&

.MARINE...
Issued at 315 PM EST Wed Nov 13 2019

Gale warning will transition to a Small Craft Advisory this
afternoon and then continuing into Thursday. After a brief lull on
Thursday afternoon, winds and waves will increase again Thursday
night.


&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Winter Weather Advisory until 10 AM EST Thursday for MIZ037-043-
     050.

LM...Small Craft Advisory until 10 AM EST Thursday for LMZ844>849.

&&

$$

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