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fxus63 kgrr 231952 
afdgrr

Area forecast discussion
National Weather Service Grand Rapids Michigan
252 PM EST Thu Nov 23 2017

Latest update...
synopsis/short term/long term/marine/Hydro

Synopsis...
issued at 252 PM EST Thu Nov 23 2017

Quiet weather patter expected through the Holiday weekend and much
of the next week. Some light rain will be possible late Friday
night into Saturday evening...with a very low chance for some
mixed precipitation. Otherwise...dry weather is expected into at
least the middle of next week.

&&

Short term...(this evening through Saturday night)
issued at 252 PM EST Thu Nov 23 2017

Focus of the short term today on winds and waves over Lake
Michigan as land weather will be pretty benign through much of the
weekend. The exception being when a weak cold front cross the
state late Friday and brings some chance for precipitation to the
northern counties Saturday afternoon/evening.

Trick to this precipitation is if the air mass is saturated enough
to actually get showers to reach the ground and when they do if
ground temperatures will be cold enough to result in the potential
for a period of slick roads. At this time the most likely
scenario looks to be very light rain/drizzle/snow with limited
chance for freezing drizzle...limited enough not to mention in zfp
or hwo.

Long term...(sunday through thursday)
issued at 252 PM EST Thu Nov 23 2017

The main thing to watch in the long term is the shallow cold
airmass off to the north. Sometimes these types of airmasses slip
south and limit the high temperatures despite the warmer air aloft
closer to 850 mb. For now...most models are in relative agreement
in showing the region remaining in the relatively milder air so
will keep the forecast that way. The NAM is in some disagreement
in showing 925 mb cold air advection 00z Mon with temps at that
level about -3 deg c for the northern counties. I looked at how
the NAM initialized 12z this am...and it featured the greatest
errors at 925 mb compared to the other models...so will not use
that solution.

A cold front does track through the County Warning Area for Tue night into Wed. At
this time the forcing looks weak and the moisture limited. I will
therefore keep the pops limited.&&

Aviation...(for the 18z tafs through 18z Friday afternoon)
issued at 1228 PM EST Thu Nov 23 2017

VFR weather is forecasted for the taf sites as the low levels are
forecasted to remain relatively dry. The wind will increase today
and a few gusts close to 25 knots are possible near kmkg.

&&

Marine...
issued at 252 PM EST Thu Nov 23 2017

Winds and waves diminishing this afternoon with a lull in
winds/waves expected overnight into early Friday. Gale force
winds and resultant large wave will develop Friday morning and
continue into Friday evening. Well coordination Gale Warning with
neighboring forecast offices this afternoon.

&&

Hydrology...
issued at 252 PM EST Thu Nov 23 2017

Water levels in a few rivers remain at advisory stage as of Thursday
afternoon. Water levels on these and other rivers will continue to
slowly fall through the end of the week. No additional hydrologic
concerns exist through the next 7 days as no significant
precipitation is expected. The next chance for rain will be Friday
evening through Saturday, but amounts are expected to remain below a
tenth of an inch.

&&

GRR watches/warnings/advisories...
Michigan...none.
Lm...Gale Warning from 7 am to 10 PM EST Friday for lmz844>849.

&&

$$

Synopsis...maczko

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