Area Forecast Discussion
Issued by NWS Grand Rapids, MI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KGRR 251734
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
134 PM EDT Sun Jun 25 2017

LATEST UPDATE...
Aviation

.SYNOPSIS...
Issued at 330 AM EDT Sun Jun 25 2017

Cool weather is expected today through Tuesday. Temperatures will
likely stay in the 60s for highs both today and especially on
Monday. We will warm slightly into the lower 70s for Tuesday.
Normal high temperatures for this time of year are in the lower
80s, so we will be well below normal. Scattered showers are
expected today through Monday with an isolated thunderstorm
possible as well. Any storms should mainly occur during the
afternoon hours.

&&

.SHORT TERM...(Today through Tuesday)
Issued at 330 AM EDT Sun Jun 25 2017

Fall like pattern is expected through the short term with
northwest upper flow. A shortwave is affecting the area at present
and will touch off scattered showers and possibly an isolated
storm through the morning hours. Another shortwave will dive
through the northwest flow on Monday. Given the cold airmass
aloft, there will likely be a diurnal flare to the precipitation
both today and on Monday. Monday may tend to overperform in regard
to precipitation as the upper shortwave will be coincident with
max heating and the thermal trough over Lake Michigan. Delta T`s
on Monday will be near 13 degrees C, so we may see lake generated
showers as well.

We should dry out for later Monday night into Tuesday as ridging
begins to build in both at the surface and aloft. Bottom line, its
going to be a cool period with some showers around through Monday
evening.

.LONG TERM...(Tuesday night through Saturday)
Issued at 330 AM EDT Sun Jun 25 2017

Surface high pressure moving by to the South of Michigan Tuesday
night into Wednesday should result in dry weather for the area. A
Low pressure system is then expected to pass over Michigan and drape
a front across the region, bringing showers and thunderstorms Monday
night into Tuesday. Another low pressure system will then move from
southwest to northeast along the front, accompanied by more rain and
thunderstorms Friday and Friday night. If the focus of the heavy
rain stretches across Lower Michigan, we could see areal and river
flooding by the end of the week.

Temperatures will be warming through the long term. They will be
below normal into mid week and near normal for the second half of
the week. Normal highs are around 80 degrees and normal lows are in
the upper 50s.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 130 PM EDT Sun Jun 25 2017

Conditions this afternoon and into tonight will be mainly VFR.
Local rain showers will be developing along with an isolated storm
or two. These could briefly reduce conditions...but it is
uncertain whether they will impact any particular TAF site. Gusty
winds will occasionally top 25 knots during the day.

Later tonight the low level moisture does increase somewhat. This
could support some lower cloud bases. Will go MVFR at this point.

&&

.MARINE...
Issued at 1048 AM EDT Sun Jun 25 2017

Based on the latest observations from the buoy offshore of
Ludington and the State Park, we have expanded the Small Craft
Advisory and Beach Hazards Statement north to include the entire
nearshore. Winds and waves will peak over the next few hours,
before a brief break. They will then come up again tonight as the
next wave moves through.


&&

.HYDROLOGY...
Issued at 1231 PM EDT Sat Jun 24 2017

The Chippewa River at Mount Pleasant crested at 14.77 feet Friday
night, about 10 inches below the record flooding of 15.58 feet in
September 1986. All river forecast points in our area have crested
as the water is being routed down through the Muskegon and Saginaw
river systems. Scattered showers Saturday through Monday should
have little effect on the rivers. Heavy rain potential may return
during the latter part of the upcoming week.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement through Monday evening for MIZ037-043-
     050-056-064-071.

LM...Small Craft Advisory until midnight EDT Monday night for
     LMZ844>849.

&&

$$

SYNOPSIS...Duke
SHORT TERM...Duke
LONG TERM...63
AVIATION...MJS
HYDROLOGY...CAS
MARINE...NJJ



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.