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000
FXUS63 KGRR 241714
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
114 PM EDT Mon Jul 24 2017

LATEST UPDATE...
Aviation

.SYNOPSIS...
Issued at 330 AM EDT Mon Jul 24 2017

Northerly winds on the back side of departing low pressure will
usher in cooler and less humid weather today, although
considerable cloudiness is likely especially east of Grand
Rapids.

High pressure will settle over the region tonight and will
provide sunny and pleasant weather Tuesday into Wednesday. Our
next chance of rain will come Wednesday night and Thursday when a
slow moving frontal boundary drops in from the northwest.

&&

.SHORT TERM...(Today through Wednesday)
Issued at 330 AM EDT Mon Jul 24 2017

Main issue today is cloud trends. Early this morning clouds have
been overspreading the region from north to south and most areas
are starting out cloudy.

For this afternoon, diurnal cumulus schemes are strongest east of
highway 131 where H8 thermal trough is more pronounced and better
moisture and cyclonic flow exists. So more clouds this afternoon
for LAN/JXN than for GRR/AZO, and probably even less cloudiness
west of highway 131. All areas clearing late this afternoon or
early this evening as the sfc high builds in.

High confidence in dry/clr weather Tonight through Tuesday night
with seasonal temps as the sfc ridge will be ovhd. The next
frontal boundary is slow to drop in and we`ll probably squeeze out
another dry day on Wednesday but temps will be warmer and
dewpts/humidity should be slowly creeping up.

.LONG TERM...(Wednesday night through Sunday)
Issued at 330 AM EDT Mon Jul 24 2017

We still anticipate showers and thunderstorms late Wednesday night
that may linger into the day Thursday, especially towards the
southeast. A fairly narrow ribbon of weak convective instability
ahead of the advancing cold front should limit the threat for severe
thunderstorms. A secondary upper potential vorticity maximum
trailing the initial maximum and its attendant cold front could
prolong rain into the day Thursday behind the front, but exactly how
long this lasts is uncertain. Overall timing with this system has
slowed with recent model runs, suggesting that much of Thursday
could conceivably stay wet. Regardless, drier and cooler air will
filter into the area beginning Friday night with dry conditions and
seasonal temperatures expected through the weekend.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 111 PM EDT Mon Jul 24 2017

Scattered to broken clouds will persist through the mid afternoon
hours...then skies will gradually clear out. The local MVFR
conditions will continue to diminish in coverage as surface
temperatures climb. The wind will be somewhat variable through the
afternoon.

With light winds and a dry airmass in place conditions are
forecasted to be VFR for Tuesday.

&&

.MARINE...
Issued at 330 AM EDT Mon Jul 24 2017

The Small Craft Advisory and Beach Hazard Statement issued last
evening are on track as the Ludington, South Haven, and St. Joe
buoys all show 4.5 foot waves at this hour. The Muskegon and
Grand Haven areas are usually sheltered somewhat from the higher
waves in a north flow regime due to the concave shoreline, so like
the idea of leaving these zones out of the marine headlines. No
changes are planned at this time.


&&

.HYDROLOGY...
Issued at 111 PM EDT Sun Jul 23 2017

No flooding concerns for the next 7 days. A frontal passage
Wednesday night into Thursday may bring thunderstorms but this is
not the setup that favors high basin average rainfall amounts.
Therefore, the rivers should behave for the foreseeable future,
especially with a cooler and drier pattern likely to follow for
late in the week and weekend.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement until 8 PM EDT this evening for MIZ037-
     043-064-071.

LM...Small Craft Advisory until 8 PM EDT this evening for LMZ844-845-
     848-849.

&&

$$

SYNOPSIS...Meade
SHORT TERM...Meade
LONG TERM...TJT
AVIATION...MJS
HYDROLOGY...Hoving
MARINE...Meade