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Area forecast discussion 
National Weather Service Grand Rapids Michigan
1046 PM EDT Wednesday Oct 22 2014

Latest update...

issued at 324 PM EDT Wednesday Oct 22 2014

Mainly dry and mild weather can be expected into early next week as
high pressure will generally control the weather for the area. A
weakening frontal system will move through Thursday night and
Friday. This will bring mainly clouds with it other than a chance
of a rain shower Thursday night. Another weak front will move
through Friday night and Saturday...but should remain dry.

Temperatures will make a run at 70 degrees across the area during
the day on Monday. A better chance of rain will move toward the area
next week on Tuesday and beyond.


issued at 1045 PM EDT Wednesday Oct 22 2014

Have updated the forecast to add some patchy fog to the forecast
late tonight into early Thursday. Crossover temperatures are
elevated with an ideal radational cooling set up in place. Most of
the stratus clouds that were east of Highway 131 earlier have


Short term...(this evening through Friday night)
issued at 324 PM EDT Wednesday Oct 22 2014

No major forecast issues in the short term portion of the forecast period.
There are a couple of minor issues to deal with including possible
stratus redevelopment tonight and then the chance of rain for Thursday night
into Friday with a weakening front.

We have added some stratus cloud cover to the forecast for tonight...
although we do not expect it to be as widespread as last night/this
morning. Stratus has been pesky today in holding on and not mixing
out as quickly as expected. This is likely to the continued flow off
of Lake Huron and with a strong subsidence inversion building in
over the area. The stratus has shown a quicker dissipation over the
past hour or two...and we expect it to continue this trend into
sunset. Some redevelopment could occur over the east until the wind
flow changes and the trajectory is not off of Lake Huron for the

We have left in the chance of rain for Thursday night...but it continues to
look like not everyone will see measurable rain. A decent upper
trough/surface front currently across the Dakotas will approach the area
on Thursday night and Friday. The main portion of the trough will head into
Canada and close off up there. Down in the u... long wave
ridge will become reestablished and help to dampen the trough out
down here. Ll moisture transport dissipates as it approaches...
helping to dissipate any rainfall. Some of it could sneak in before
it totally dries up...but it will not affect the area in a
significant way.

We will likely see clouds hold on over the area for at least the
first portion of the day on Friday as low level moisture holds on. This
low level moisture should mix out and dissipate in the
afternoon...allowing for a decrease in cloud cover. If we can get
rid of the clouds soon enough...60 will be possible across the area
with h850 temperatures around 10c.

Long term...(saturday through wednesday)
issued at 324 PM EDT Wednesday Oct 22 2014

Two systems will affect the County Warning Area during the long term. The first is a
cold front that will pass through the County Warning Area Saturday. The low
associated with it will be near Hudson Bay so we/re not looking at
much in the way of dynamics with it. The front should pass through
dry but will drop highs 5 degrees or so from Saturday to Sunday.

The next system is much more dynamic and will provide a better
opportunity for precipitation. Developing low pressure over Kansas will move
toward western Wisconsin by Monday. Some warm advection type precipitation
may develop Monday but doesn/T look too significant as the low is
filling as it moves northeast. The better chance for precipitation looks to
come Monday night or Tuesday when the trailing cold front moves
through. The GFS is much quicker with this system because the European model (ecmwf)
develops a trailing low over Oklahoma and slows the front up a bit.
The trailing low also pushes more moisture northward too which
should enhance precipitation potential. If the European model (ecmwf) is correct the main
batch of precipitation would arrive Wednesday vs earlier Tuesday with the
GFS. Took a compromise approach for now...but wouldn't be surprised
to see things slow down.

Temperatures will warm above normal early next week ahead of the cold
front. Temperatures approaching 70 seem possible across the southern County Warning Area late
Monday with 60s elsewhere.


Aviation...(for the 00z tafs through 00z Thursday evening)
issued at 803 PM EDT Wednesday Oct 22 2014

Stubborn broken-overcast cloud deck with bases around 2000 feet continues to
impact the area from btl to lan to mbs. Will forecast these clouds
dissipating by 03z but confidence is low since nighttime has
settled in and lack of mixing under the surface ridge could make
it difficult to completely get rid of this stratus tonight.

The other issue for later tonight is the potential for new areas
of IFR stratus and fog to develop. Currently the surface dew points
are in the middle to upper 30s and forecast low temperatures are expected to be
in lower 30s. Time of year and ideal radiational cooling regime
under the surface ridge suggests that nocturnal stratus/fog has a
decent chance of developing after 09z and lingering through

The exception would be if the current cloud deck east of GRR does
not dissipate... then the btl-lan-mbs corridor would not be
susceptible to the fog and lower based stratus.

Should any IFR/MVFR conditions be present Thursday morning... the
trend should be for VFR to develop everywhere by 18z.


issued at 324 PM EDT Wednesday Oct 22 2014

We do not expect any headlines to be needed through the day on
Friday. Winds will come up some late Thursday and Thursday night ahead of the
weakening wave moving in. It looks like winds may approach criteria
up toward Ludington...but should remain just below wind and wave

The next possible set of headlines would be for the Friday night and
Sat time frame along and behind a cold front expected to move


issued at 324 PM EDT Wednesday Oct 22 2014

No hydrology issues expected through early next week. Mainly dry
weather is expected through that time. Rivers are running average to
slightly above average across the area. The dry weather will only
allow them to drop off more.


GRR watches/warnings/advisories...


short term...njj
long term...93

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