Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 271929

Area Forecast Discussion
National Weather Service Grand Rapids MI
329 PM EDT Sun May 27 2018

Synopsis/Short Term/Long Term/Marine/Hydro/Climate

Issued at 321 PM EDT Sun May 27 2018

A few showers and thunderstorms are possible well inland through
this evening and then again Monday evening, though most areas will
stay dry. Hot and humid weather continues into Memorial Day
before slightly cooler readings move in for mid week. By the end
of the week, temperatures drop further into the 70s. Rain moves in
mid week in association with the remnants of Alberto.


.SHORT TERM...(This evening through Tuesday night)
Issued at 321 PM EDT Sun May 27 2018

Adequate instability through this evening will allow for a few
showers and storms to form mainly near and east of US 127 and
also across western Lake Michigan. Limiting factors for
organization and intensity include weak deep layer shear and weak
forcing (subtle surface trough shown on RAP13 and also a weak H500
shortwave). Nevertheless, any showers that do form could quickly
become thunderstorms based on observed radar trends this
afternoon. Hi-res CAMs suggest any activity over Lake Michigan
will not make it to shore, but we will keep an eye on things.

For Memorial Day, hot and humid conditions are expected with highs
in the low to mid 90s away from the lake. These temperatures will
come close to monthly records for May, not just for Memorial Day.
See the Climate section below for historical information. In
terms of precip, we are largely expecting a dry day except for an
isolated shower or storm possible in the evening mainly in the
same areas that are at risk today...primarily near US 127.
Otherwise, mostly sunny and hot will be the rule.

A few pop up showers and thunderstorms will be possible Tuesday
in a pattern reversal compared to today and Memorial Day as winds
shift out of the east. That brings the risk for diurnally driven
showers/storms to pop up west of US 127 and toward the lakeshore.
Coverage won`t be widespread so many areas will stay dry.


.LONG TERM...(Wednesday through Sunday)
Issued at 321 PM EDT Sun May 27 2018

Focus of the long term continues to be on Alberto which is currently
strengthening in the Gulf of Mexico and its affects on our weather
mid week. A remnant low is forecast to move through Lower Michigan
in the Wednesday and Thursday time frame which will be associated
with deep tropical moisture. Rainfall amounts continue to look like
0.75 to 1.25 inches with the potential for some higher amounts. The
exact track of the system still has quite a bit of uncertainty that
far out so it is prudent to not get caught up in the exact details.
Bottom line we are looking at a decent rain event on Wednesday and
Thursday. If the current track trends a little bit to the east
amounts toward or exceeding 2 inches could be possible.

We may need to trend chances for showers and storms up a bit late in
the week as an upper shortwave trough traverses the area.
Temperatures will not be as warm in the long term as compared to the
short term given the chances for precipitation and clouds.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 212 PM EDT Sun May 27 2018

VFR weather is expected the next 24 hours for the most part. The
only exception will be the chance of some light fog late tonight,
but not overly confident in that occurring. Did include some MVFR
fog at KLAN and KJXN, but otherwise expecting conditions to remain
VFR. Fog should be the only restriction to visibility the next 24
hours as any showers and storms should remain east of the TAF
sites this evening. Its conceivable we see a shower at KLAN and
KJXN, but felt the threat was too small to include. Skies will be
mostly clear with a lake breeze this afternoon going light and
variable tonight.


Issued at 321 PM EDT Sun May 27 2018

Fairly tranquil conditions expected with generally 1 foot waves or
less. Patchy fog is possible but should not be a problem for most


Issued at 321 PM EDT Sun May 27 2018

Water levels in most rivers will continue to fall through Tuesday
as mostly dry weather is expected. The Muskegon and Chippewa River
Basins have seen slight rises due to localized heavy rainfall over
the past 24 hours. These rises will be short-lived, and levels
should begin to fall by tonight.

The next chance for widespread rainfall will be on Wednesday and
Thursday as the remnants of a tropical system, Alberto, track up
into the Great Lakes. The exact track of this system is still a
little uncertain, making it hard to judge where the heaviest
rainfall will occur and how much rain will fall. The latest guidance
from the NOAA Weather Prediction Center is for between 0.75 and 1.5
inches of rainfall over West Michigan. Rainfall amounts of this
magnitude over a few days typically do not cause widespread or
serious flooding, but we will continue to monitor this system
closely as it moves inland and evolves. Expected rainfall amounts
may change. There is potential for some rivers to rise out of their
banks or reach minor flood stage if locally higher totals occur, or
if rain is focused in smaller river basins.


Issued at 321 PM EDT Sun May 27 2018

All-time May records are as follows with projected high
temperatures on Memorial Day:

GRR: 95 (May 31, 1934) / Forecast - 94
LAN: 96 (May 28, 1874) / Forecast - 94
MKG: 93 (May 29, 1962) / Forecast - 87

Daily records for 5/28:

GRR: 92 / LAN: 96 / MKG: 89

Memorial Day records:

GRR: 92 (May 30, 1919)
LAN: 95 (May 30, 1895)
MKG: 89 (May 28, 2012)




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