National Weather Service Raw Text Product

727 
FXUS63 KGRR 031933
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
333 PM EDT Fri Apr 3 2020

LATEST UPDATE...
Synopsis/Discussion/Marine/Hydro

.SYNOPSIS...
Issued at 330 PM EDT Fri Apr 3 2020

-Light Rain event still in the works for Saturday

-Showers and storms possible Monday Night through Tuesday Night

-Pattern change to cooler weather starting Wednesday

&&

.DISCUSSION...(This evening through next Friday)
Issued at 330 PM EDT Fri Apr 3 2020

Light Rain event still in the works for Saturday

Our rain event is still on track for Saturday, but there are 
several things we are noticing today in the models that have 
changed. First off, it comes in slightly quicker, possibly before 
daybreak towards the Lake Michigan shore. Also, it seems to exit 
quicker to the east in today's models as well. The entire event 
seems to be over by 4pm to 5pm Saturday afternoon. The final 
change is that precipitation looks to be even lighter with the NAM
below 0.20 in all areas and the GFS less than 0.10. Bottom line, 
nothing to write home about. Some light rain accompanied by lower 
ceilings and gray skies. We do look to clear out fairly quick on 
the backside of this system with a clearing taking place between 
6pm and 2am Saturday evening and night. We will have to watch out 
for some fog develop into Sunday morning with BUFKIT overviews 
having “that look”.

-Showers and storms possible Monday Night through Tuesday Night

Showers and storms are still in the forecast early next week 
beginning Monday evening along a warm front and then associated 
with the weak low itself and associated cold front Tuesday into 
Tuesday night. Model CAPE values are not too impressive with the GFS 
being a bit lower today and the ECMWF showing more instability 
now. Tuesday evening ahead of the passage of the front still looks
to be the time frame where we stand the best chance for storms 
and locally heavier rains. CAPE values rise to around 1,000 j/kg 
over much of the area at 800pm Tuesday. Again, this does not look 
to be a widespread heavy rain, but quarter to half inch rain 
totals are probably likely in many areas with heavier swaths in 
spots.

-Pattern change to cooler weather starting Wednesday

A pattern change occurs mid to late next week as we return to 
troughing and northwest upper flow. 850mb temps dip back below 0C 
which will drop high temperatures back at least into the 40s if 
not cooler by next Friday. A return to reality in the Great Lakes 
in the spring with an up and down temperature forecast.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 158 PM EDT Fri Apr 3 2020

VFR conditions persist area wide at 18z, with some mid clouds 
drifting in from the west. These mid clouds have bases of 8,000ft 
to 10,000ft and will continue to spread in this evening and 
gradually lower and thicken with time. These clouds are associated
with a trough of low pressure moving our direction from the Upper
Midwest. Ceilings will dip below 5,000ft after midnight and lower
into the MVFR range between 10z and 15z Saturday morning. For a 
short time restrictions to visibility will occur due to light rain
and fog lowering to 3-5SM between 11z and 17z across the area. 
The rain overall will be light but ceilings will dip in some areas
to IFR, or to below 1,000ft. The rain should end by the early 
afternoon hours of Saturday. Ceilings will continue to 
improve/lift Saturday afternoon and the trough presses off to the 
east.

Winds will be variable under 10 knots this afternoon as we are
still under the influence of high pressure. Winds will pick up
from the south towards daybreak on Saturday and shift quickly to
the west and northwest thereafter. The strongest winds of the next
24 hours will be Saturday morning at KMKG where winds off the lake
will pick up into the 10-20 knot range from the northwest.

&&

.MARINE...
Issued at 330 PM EDT Fri Apr 3 2020


Winds and waves will remain light/fairly calm through roughly 
daybreak on Saturday. Northwest winds behind the passage of a 
trough of low pressure will kick up into the 15-25 knot range 
especially during the afternoon and early evening. We expect waves
to build into the 3 to 5 foot range from the Noon hour through 
about 11pm. We will be issuing a Small Craft Advisory for this 
time frame. 

Surface high pressure builds in for Saturday night through Monday 
which will bring another period of light winds and waves that 
will be fairly flat, likely 2 feet or less. Even with the passage 
of a low pressure system early next week, the pressure gradient 
does not look worthy of concern. We will likely continue lower 
wave heights into Tuesday. The next higher wind/wave event looks 
to be in the Wed/Thurs time frame of next week.

&&

.HYDROLOGY...
Issued at 330 PM EDT Fri Apr 3 2020

River levels are falling in most areas now from recent rains. We 
have several sites above Action Stage/Bankfull. The sites that 
remain above bankfull include Ionia, Comstock Park and Robinson 
TWP on the Grand, Maple Rapids on the Maple, Hastings on the 
Thornapple and Vicksburg on the Portage. 

We have a very light rain event on Saturday with amounts generally 
less than a tenth of an inch. Rivers will not be affected by this
rain much at all. Another rain event in the Monday night through 
Wednesday time frame of next week may contribute a quarter to a 
half inch of rain, but this should not affect river levels much 
either. Rivers will continue to fall through Monday of next week.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...Small Craft Advisory from noon to 11 PM EDT Saturday for 
     LMZ844>849.

&&

$$

SYNOPSIS...Duke
DISCUSSION...Duke
AVIATION...Duke
HYDROLOGY...Duke
MARINE...Duke