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Area forecast discussion
National Weather Service Grand Rapids Michigan
728 PM EDT Thu Sep 19 2019

Latest update...
aviation

Synopsis...
issued at 250 am EDT Thu Sep 19 2019

- high temperatures will reach into the 80s for most locations
Friday and Saturday.

- Rounds of heavy rain possible across west Michigan Saturday
night through early Monday morning.

&&

Discussion...(today through next wednesday)
issued at 250 am EDT Thu Sep 19 2019

The center of surface high pressure that has been in control over
the area for the past few days will slowly slide down the eastern
Seaboard tonight through Friday night, allowing for a gradual
increase in southwest flow and moisture over the next 36 hours.
Increasing mid-level moisture and several small shortwaves
passing through the area as they ride the periphery of the upper
ridge situated over the southeastern U.S. May allow for a few
showers tonight, or even a thunderstorm by Friday. Coverage will
be low if they do develop/hold together as they will be
encountering very dry air in the low-levels and a fairly stable
thermal profile. Feel a little more confident in low pops by
Friday night and Saturday as southwest flow ramps up and we see a
good push of mid-level Theta-E advection across southwest
Michigan. Severe weather is not expected as instability looks
limited.

Upper trough over the western U.S. Will slide across the Great
Lakes Saturday night through early Monday, pulling a plume of
subtropical moisture up through west Michigan. Models still
disagree on timing and placement of heavier rounds of rain
Saturday night through early Monday morning, but potential remains
for a part of the area to see two or more inches of rain.

&&

Aviation...(for the 00z tafs through 00z Friday evening)
issued at 728 PM EDT Thu Sep 19 2019

VFR conditions to continue through Friday afternoon. Winds will be
southeast tonight at 5 kts or less going southwest on Friday.

&&

Marine...
issued at 250 am EDT Thu Sep 19 2019

Light winds will limit wave heights to a foot or less through
Friday night. An increase in south to southwest winds will then
allow wave heights to build over the weekend. Small craft
advisories and beach hazard statements for dangerous swim
conditions will likely be needed from Saturday afternoon Onward
for locations north of Holland, and for all Lakeshore areas on
Sunday.



&&

GRR watches/warnings/advisories...
Michigan...none.
Lm...none.
&&

$$

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