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 300730
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
330 AM EDT TUE AUG 30 2016

LATEST UPDATE...
Synopsis/Short Term/Long Term/Marine

.SYNOPSIS...
Issued at 330 AM EDT Tue Aug 30 2016

A slow moving cold front will bring scattered showers and
thunderstorms along with warm and humid conditions today into
tonight.

The front will move south of the area by Wednesday afternoon and
north winds behind it will deliver cooler and less humid air for the
rest of the week.

Currently the majority of the upcoming holiday weekend looks dry
with above normal temperatures. The next chance of storms will
arrive on Labor Day.

&&

.SHORT TERM...(Today through Thursday)
Issued at 330 AM EDT Tue Aug 30 2016

Scattered showers/storms have recently developed over srn Lk MI on
the leading edge higher PWAT/theta-e air. Latest near term HRRR
guidance indicates that this activity will impact areas mainly near
and south of I-96 this morning.

As we head into the afternoon hours and sfc instability builds, look
for scattered diurnal tstms to develop, with highest concentration
of storms inland from lk MI and the lake breeze front - primarily
near and east of Highway 131. The best sfc convergence later today
looks to set up in a band from Kalamazoo to Lansing and this is
where most of the storms should be situated from 4 pm to 8 pm.

The main threat from storms this afternoon and early evening will be
locally heavy rainfall. Juicy air mass will be in place with sfc dew
pts near 70 and PWATs near 2 inches. Fcst soundings reveal deep
skinny cape and high freezing levels, and storms should be very slow
movers.

Height falls Wednesday/Thursday and evolution of a deep upr trough
over the ern grtlks rgn will shove the sfc cold front to the south
and send a much drier air mass into the state. A shortwave trough
and secondary sfc trough is progged to slide south Wednesday night
into early Thursday and could touch off a period of cloudiness with
some light showers.


.LONG TERM...(Thursday night through Monday)
Issued at 330 AM EDT Tue Aug 30 2016

High pressure will continue to build in and produce fair weather
with seasonable temperatures Thursday night through Saturday. Fair
weather will continue Sunday along with warmer temperatures and
gradually increasing humidity levels as southerly flow waa develops
on the back side of the ridge.

Most of the holiday weekend should be dry but there is a chance for
a shower or thunderstorm beginning on Labor Day as continued
southerly flow results in increasing moisture. However the
relatively better chance for a few showers and thunderstorms should
hold off until next Tuesday or Wednesday as the next system moves in
from the west.

Temperatures will undergo a gradual moderating trend this weekend
into early next week. High temperatures by Sunday and Monday will
average around 5 to 10 degrees above normal.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 100 AM EDT Tue Aug 30 2016

Vfr conditions will continue for most of the overnight period
before deteriorating to mvfr and possibly ifr around or shortly
prior to daybreak Tuesday due to patchy fog. Fog will linger
through mid morning before dissipating when conditions will
improve to vfr.

Scattered showers and thunderstorms will develop Tuesday
afternoon. Prevailing conditions will remain vfr Tuesday afternoon
but could briefly dip to mvfr/ifr in heaviest showers and storms.
Scattered showers will linger Tuesday evening along and ahead of
the cold front that will be moving through overnight.


&&

.MARINE...
Issued at 330 AM EDT Tue Aug 30 2016

Period of strong north flow will bring hazardous winds and waves
beginning late Wednesday, continuing into Thursday evening. This
will probably also lead to an upwelling event which could cause our
recent enjoyable stretch of warm lk mi water temps to plunge at the
shore going into the holiday weekend.

&&

.HYDROLOGY...
Issued at 1100 AM EDT Mon Aug 29 2016

The Portage River at Vicksburg has fallen below flood stage and is
slowly receding, so the Flood Warning has been canceled. Showers
and thunderstorms Tuesday into Wednesday are expected to provide
basin-average rainfall amounts between a tenth and quarter inch.
Dry weather the rest of the week signals a low flood potential.

&&

.GRR Watches/Warnings/Advisories...
MI...None.
LM...None.
&&

$$

SYNOPSIS...Meade
SHORT TERM...Meade
LONG TERM...Laurens
AVIATION...Laurens
HYDROLOGY...CAS
MARINE...Meade



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