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Area forecast discussion 
National Weather Service Grand Rapids Michigan
1015 PM EDT Tuesday may 26 2015

Latest update...

issued at 320 PM EDT Tuesday may 26 2015

After showers and thunderstorms this evening bring the potential for
heavy rain and damaging winds...a chance for showers and
thunderstorms will linger into Wednesday afternoon. Then...after a
dry Thursday...showers and thunderstorms are expected again Friday
into Saturday. Sunday and the coming work week look mostly dry with
gradually moderating temperatures.


issued at 1015 PM EDT Tuesday may 26 2015

Upper shortwave is pivoting off to the northeast across the
western Great Lakes this evening. The associated surface low is
moving northeast across Wisconsin. Southwest lower Michigan is
located in the warm sector of this system with southwest winds
expected through the night.

Cannot rule out a few showers tonight as we will be located ahead
of the upper shortwave trough all night. Threat exists for a few
thunderstorms as well for a few more hours. Case in point...a few
cells have developed in the last half in southeast
Newaygo County...others over south central lower Michigan near
Eaton Rapids. Kept the mention of an isolated thunderstorm through
200 which time instability should be trending toward almost
none. Have a chance of a shower through 200am...30pct...with
isolated shower wording...20pct...after 200 am.


Short term...(this evening through Thursday night)
issued at 320 PM EDT Tuesday may 26 2015

Severe Thunderstorm Watch recently issued with increasing
destabilization and shear ahead of lifting upper wave. Please
reference Storm Prediction Center mesoscale discussions for further details.

Expect a lull in precipitation after midnight with wraparound
moisture currently over WI/Minnesota entering northern lower Michigan
Wednesday. Put better rain chances over our northern zones closer to
this better moisture. South-central lower Michigan also has a
slightly greater chance of precipitation as more discrete
convective cells develop in the late morning/early afternoon
hours. Severe weather is not expected.

Thursday and Thursday night will be fairly uneventful with surface
and upper ridging in control.

Long term...(friday through tuesday)
issued at 320 PM EDT Tuesday may 26 2015

Impact weather in the extended includes heavy rain potential Friday
and Saturday with moisture pooling ahead of a cold front. There may
also be a frost threat across the northern zones Sunday and Monday

For the end of the week rain event...high precipitable water values
and strong low level convergence along the slow moving front should
cause some rainfall totals to exceed an inch or two across much of
the forecast area. The rains should be ending from northwest to
southeast Saturday afternoon and evening with cool high pressure
building in.

The high will bring fair...dry and cool weather into early next
week. Lows could drop into the 30s across the colder locations in
the central and northern forecast area Sunday morning and possibly
Monday morning as well.


Aviation...(for the 00z tafs through 00z thursday)
issued at 720 PM EDT Tuesday may 26 2015

Primarily VFR conditions are anticipated this evening with scattered
lingering showers. Conditions will gradually deteriorate to mainly
MVFR late tonight through the early to middle morning hours Wednesday
due to patchy fog. Conditions will gradually improve to VFR late
Wednesday morning but winds will veer to the west-southwest and increase to 15
to 20 kts with gusts to 25 kts by late morning.


issued at 1015 PM EDT Tuesday may 26 2015

Will be keeping an eye on southwesterly winds tonight over Lake
Michigan which may try to rise into the 20-25 knot range at times.
For now have 15-20 knots and 2-4 footers mentioned. If mixing
overperforms a little we could flirt with some Small Craft Advisory conditions
tonight. Also...will be watching the fog in the webcams with
warm/moist air flowing over the Cold Lake.


issued at 113 PM EDT Tuesday may 26 2015

River levels are low and stable. Expecting 1/2 to 3/4 of an inch of
precipitation through Wednesday. This should lead to slowly
increasing river levels by Wednesday. Expecting no or minor/nuisance
flooding by weeks end.

A potential for more rain Friday into Sunday (over an inch) may push
some streams and rivers above bankfull by next week... if these
amounts are realized.


GRR watches/warnings/advisories...


short term...tjt
long term...ostuno

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