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Area forecast discussion 
National Weather Service Grand Rapids Michigan
400 PM EDT Wednesday Aug 27 2014

Latest update...

issued at 327 PM EDT Wednesday Aug 27 2014

High pressure will bring fair weather through Thursday. Then a warm
front will move in Thursday night with showers and thunderstorms
lasting into Saturday. A cold front will arrive with more showers
and thunderstorms on Monday.


Short term...(this evening through Friday night)
issued at 327 PM EDT Wednesday Aug 27 2014

Weather impacts in the near term will begin on Friday as showers and
thunderstorms return in an area of middle level warm advection north of
a surface warm front. Model guidance continues to be fairly consistent
in timing and location with the rain arriving late Thursday night
and the bulk of across the northwest forecast area.

Coverage of showers will move east on Friday and Friday night but
will be decreasing as forcing weakens. Severe threat is low but
moist atmosphere will mean heavy rain threat.

Long term...(saturday through wednesday)
issued at 327 PM EDT Wednesday Aug 27 2014

The weekend looks pretty wet as a cold front slowly moves south
across lower Michigan. Both the European model (ecmwf) and GFS are in pretty good agreement
showing a wave of low pressure moving NE along the boundary bringing
showers and storms to the County Warning Area. Precipitable waters around 2 inches suggest the
potential for heavy rain Saturday and Saturday night. Shear less
than 30 kts points toward non severe storms.

Weak ridging behind the wave Sunday means decreased probability of precipitation. But SW
flow aloft will send several short waves toward the Great Lakes so
the chance of precipitation isn/T zero.

An active cold front will move east from the plains Monday/Monday
night and chances for rain will increase again. A low level jet over the County Warning Area
will only enhance the potential. The chance of rain will continue
through Tuesday as a broad upper trough moves across the upper
Midwest. The trough lifts out Tuesday night which should lead to a
dry Wednesday.


Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 132 PM EDT Wednesday Aug 27 2014

We/re looking at VFR conditions this afternoon. Cumulus will be scattered-broken
just above 3000 feet this afternoon. After sunset...clear skies
are expected.


issued at 327 PM EDT Wednesday Aug 27 2014

High pressure will move east on Thursday and winds and waves will
increase this weekend as flow GOES southerly. Wave heights near 4
feet are expected by late Friday...along with thunderstorms. These
conditions will continue into Saturday.


issued at 400 PM EDT Wednesday Aug 27 2014

Heavy rain threat increases late Thursday night into Saturday as
moist airmass returns. Slow moving storms could bring some
localized flooding. A cold front could bring more heavy rain on


GRR watches/warnings/advisories...


short term...ostuno
long term...93

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