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Area forecast discussion 
National Weather Service Grand Rapids Michigan
1019 am EDT Thursday Oct 23 2014

Latest update...

issued at 330 am EDT Thursday Oct 23 2014

The weather will remain relatively quiet by October standards
through the weekend. High pressure will bring fair weather today
with a good deal of sunshine. Tonight a weak trough of low pressure
will provide some light rain showers although amounts will be light.
Skies will turn partly sunny on Friday with a cold front set to move
through late Friday night and Saturday morning. At this point it
looks like the front will slide through dry Friday night and
Saturday. High temperatures the rest of this week and into the
weekend will remain near to slightly above normal in the 50s to
around 60.


issued at 1019 am EDT Thursday Oct 23 2014

We have allowed the dense fog advisory to come to an end across
the entire area. There are a few observations at the airports
still indicating visibilities around 1/4sm...however conditions are
generally improving quickly across the area. An example is kgrr
still reporting 3/4sm at 1416z...however conditions around most of the
Airport have improved much more at the same time.

We will maintain a dry forecast for the day today. Most of the latest
model guidance is showing the threat for rain showers coming in
after 00z across the Lakeshore. With the current movement of the
rain showers in WI moving more north than will take a
while for precipitation to make it to the area. Also...a dry atmosphere in
place will erode the precipitation as it tries to move toward the area..

Update issued at 544 am EDT Thursday Oct 23 2014

Have opted to issue a dense fog advisory for the entire area
through 1000 am. Fog has expanded quite a bit in the last half
hour with stratus beginning to show up in the fog satellite
product which is indicative of a more widespread fog. Have quarter
mile visibilities in all areas now and it will likely expand to
areas not currently seeing it. A light southeast flow is in place
in the lowest 50mb/S per the ruc13 and this should advect it even
to the Lakeshore areas with time. We still have about 2.5 hours
before it should expand and become more dense. Npwgrr
is already out.


Short term...(today through saturday)
issued at 330 am EDT Thursday Oct 23 2014

Limited concerns in the short term but the focus was on extent of
fog this morning...chance for rain tonight and spotty light rain
chances Saturday morning.

As for the fog...think we are looking at patchy radiational ground
fog this morning. Several sites are currently at a quarter of a mile
visibility so we will be keeping an eye on whether or not it expands
and becomes worthy of a dense fog advisory. Fog satellite product is
beginning to show hints at stratus forming.

Regarding rain chances looks about the same as the last
few nights...30/40 percent chance especially in the west during the
evening. A shortwave currently seen in the water vapor imagery over
the Dakotas moves through out region tonight. Some weak moisture
transport occurs at 850mb/S along with a weak surface trough. Feel
the best chances will occur early along and west of Highway
131...becoming isolated overnight and ending.

Another brief shot at some very light rain may come late Friday
night into Saturday morning as a cold front traverses the area. The
main upper support with this front is well north of southwest
lower...but there is a push of some moisture into the area from the
south. The European model (ecmwf) is painting some very light precipitation along the Lake
Michigan shore Saturday morning. Kept the forecast dry at this point
as not confident enough we will see anything.

Otherwise...quiet today outside of some morning fog. We should
become at least partly sunny Friday afternoon as the deeper moisture
peels off to the east.

Long term...(saturday night through wednesday)
issued at 330 am EDT Thursday Oct 23 2014

The upper low moves to eastern Canada to start the extended period.
This will allow upper and surface ridging to build over the upper
Midwest. The chilly temperatures will move out of the region as this
occurs with solid warm advection by Sunday night. The latter part
of the weekend continues to look dry...but we should see warm
advection clouds arrive on the heels of this warmup Sunday night
into Monday.

The next chance of rain should move in Monday or Monday night. The
vigorous system that was noted on water vapor this morning off the
British Columbia coast should move over The Rockies and help pump
warm and moist Gulf air into the region. There is poor agreement in
the models on the timing of this system into middle week but it appears
a cold front comes through Tuesday or Tuesday night. So the rain
chances should peak in this time frame. Added thunder to the
forecast for Tuesday given the higher temperatures/dewpoints expected with
the arrival of the front. It should turn colder again once the
front passes with highs back into the 50s by Wednesday.


Aviation...(for the 12z tafs through 12z Friday morning)
issued at 734 am EDT Thursday Oct 23 2014

Dense fog is fairly widespread across the area this morning with
LIFR conditions prevalent. The fog and stratus will linger into
the morning hours before lifting between 14z and 16z. High
clouds will spread in during the afternoon...but VFR weather is
forecast. VFR conditions will persist into the evening hours as
clouds lower to bases around 5000ft after dark. Light rain showers
will spread in this evening as well. MVFR conditions will try to
settle in tonight as ceilings and visibilities lower with time.


issued at 330 am EDT Thursday Oct 23 2014

No marine concerns today through Friday with high pressure sliding
east allowing for light southerly flow to take hold. The next chance
for winds and waves becoming an issue will be from Friday night into
Saturday as a cold front sweeps through the region. Saturday
especially...20-30 knot northwest winds can be expected which will
boost wave heights.


issued at 330 am EDT Thursday Oct 23 2014

Still not expecting any Hydro issues into early next week. Very
limited rain is expected through Monday. The first chance for rain
will be tonight...but not expected totals more than 0.05 anywhere.
Mainly dry weather is forecast through the weekend. River levels
remain low at the present time.


GRR watches/warnings/advisories...


short term...Duke
long term...jk

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