Area Forecast Discussion
Issued by NWS Grand Rapids, MI

Home | Current Version | Previous Version | Text Only | 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
FXUS63 KGRR 142344

Area Forecast Discussion
National Weather Service Grand Rapids MI
744 PM EDT Fri Oct 14 2016


Issued at 314 PM EDT Fri Oct 14 2016

High pressure will move east and a cold front will cross Michigan
Saturday night and Sunday. Showers and thunderstorms will accompany
the cold front. That cold front will quickly move north as a warm
front Monday and a few showers are possible then.


.SHORT TERM...(This evening through Sunday night)
Issued at 314 PM EDT Fri Oct 14 2016

Forecast concerns deal with the cold front moving through the cwa
Saturday night and Sunday.

We`re expecting breezy conditions to develop Saturday as the
pressure gradient tightens ahead of the cold front. There isn`t a
tremendous amount of upper support with this cold front and what
there is remains north of Lake Superior. Weak instability also is
progd to accompany the front Saturday night. Timing of the pcpn by
the models has been pretty consistent during the past several model
runs and continues to bring showers into the nw cwa around 10 pm and
then move it steadily across the cwa reaching the Lansing area
around 4 am. Pcpn should be out of the cwa by 00 Monday.

The cold front won`t get too far south before low pressure in the
Northern Plains lifts it north through the cwa. There may be a few
showers late Sunday night but the atm will be fairly dry by then and
we don`t see a large rain threat.

Temps will be warm enough tonight that frost doesn`t look like a
threat either. Highs around 70 Saturday and Sunday will be several
degrees above normal.

.LONG TERM...(Monday through Friday)
Issued at 314 PM EDT Fri Oct 14 2016

A warm front lifts north on Monday with a few showers and possibly a
thunderstorm lingering across the northern forecast zones through
Monday night as a sfc low tracks across northern Lower Michigan.

As the sfc low moves east on Tuesday, the front sags south as a cold
front. There may be a sharp gradient in max temps Tuesday as clouds
and showers will keep the northern zones cooler while maxes will be
near 80 across the south. We will have to watch the potential for
any convection Tuesday afternoon as 0 to 6 km shear values are
forecast to be near 60 knots in afternoon.

Much cooler weather follows for the rest of the week although
confidence is low in the precip forecast as there is a lot of
uncertainty in the evolution of the upper trough, specifically if
and where the trough cuts off into a closed low. Given the range of
solutions, the chances for precip should be lowest on Wednesday and
increasing Thursday and Friday. Temperatures were adjusted down a
bit at the end of the period  towards the thermal pattern depicted
by the ECMWF the past few days.


.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 733 PM EDT Fri Oct 14 2016

VFR weather is forecasted to prevail tonight as the low levels
remain relatively dry. The southerly flow will advect in
increasing amounts of low level moisture later tonight into
Saturday morning. It appears that low level clouds will be moving
in Saturday morning. The most likely scenario has MVFR level
clouds...but a risk for IFR does exist. In addition the wind will
be on the increase during the day. Gusts over 25 mph could. It
looks like showers and even a few thunderstorms will be
approaching from the west later in the day. They should not arrive
until after 00z Sun.


Issued at 314 PM EDT Fri Oct 14 2016

The small craft advisory remains in effect through Sunday morning.
South winds will strengthen Saturday ahead of the cold front ans
waves will build to 4 to 7 feet.


Issued at 100 PM EDT Fri Oct 14 2016

River levels are running above normal for this time of year in the
upper half of the Grand basin, including Hastings, Ionia, and points
upstream. Basin average rainfall amounts approaching one inch are
expected Saturday night through Monday in parts of the area. Main
stem rivers should remain within their banks. Smaller rivers may
exceed bankfull if locally heavier precip falls within their basins.
Precip amounts may be locally enhanced by scattered thunderstorms.


LM...Small Craft Advisory until 8 AM EDT Sunday for LMZ847>849.

     Small Craft Advisory from 2 AM Saturday to 8 AM EDT Sunday for



LONG TERM...Ostuno
MARINE...04 is the U.S. government's official web portal to all federal, state and local government web resources and services.