Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 220721

Area Forecast Discussion
National Weather Service Grand Rapids MI
321 AM EDT Thu Mar 22 2018

Synopsis/Short Term/Long Term/Marine

Issued at 320 AM EDT Thu Mar 22 2018

The cool dry weather of the past week will continue through the
weekend. The next storm system will just miss Michigan to the
south Friday night into Saturday with a considerable amount of
snow just south of I-80. The pattern finally changes early next
week when a storm from the Central Plains heads toward the Great
Lakes. This system could bring a good soaking to the area with
warmer temperatures.


.SHORT TERM...(Today through Saturday)
Issued at 320 AM EDT Thu Mar 22 2018

Cool and dry weather will continue through Saturday. Skies will be
mostly clear most of the time.

There is a secondary northern wave that helps to bring another
polar high (currently near the North Pole)down to replace the one
currently over Hudson Bay. This will bring a sudo cold front
through our area Saturday morning but it hardly be noticed. Since
our actual weather will stay about the same.

The "BIG PICTURE" shows...persistence rules through the weekend.
An omega block (upper low over the Canadian Maritimes, upper ridge
over the central CONUS into central Canada and another upper low
over the western CONUS) has more or less continued over the past 7
days or so. With Michigan being on the down stream side of the
upper ridge, all of the storms have tracked south of Michigan
through the Ohio Valley this past week. One more system will do
that Friday night into Saturday. After that we will see a major
change in the upper wave pattern as the blocking system over the
western CONUS finally gets booted east into the Central Plains.
That will set the stage for Gulf moisture to surge north into
Michigan ahead of the upper trough heading east across the CONUS.

Meanwhile through, the really cold air is blocked by the arctic
jet being north of 65N. The warm air remains south of the southern
branch of the polar jet (South of 30N). This has keep and will
keep the really warm air and the really cold air from reaching
this area.

.LONG TERM...(Saturday night through Wednesday)
Issued at 320 AM EDT Thu Mar 22 2018

A ridge of high pressure will continue in control of the wx pattern
Saturday night through Sunday. A consensus of latest medium range
guidance continues to suggest that all the snow associated with the
TN Valley low pressure system will stay south of our fcst area
Saturday evening.

Strong southerly flow will develop Monday on the back side of the
departing ridge. This in conjunction with some sun will help to
boost high temps into the 50`s. Continued southerly flow off the
gulf will result in a gradual increase in moisture and potential for
some warm air advection rain showers to develop by late Monday night
and Tuesday. The showers will potentially linger through midweek.

Temperatures will average close to normal for this time of year this
weekend before moderating to 5 to 10 degrees above normal for the
early to middle portion of next week.


.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 1155 PM EDT Wed Mar 21 2018

VFR conditions will continue through Thursday evening. Winds
through Thursday evening will be out of the northwest aob 10 kts.


Issued at 320 AM EDT Thu Mar 22 2018

Winds and waves will remain below Small Craft Criteria through
the weekend.


Issued at 1035 AM EDT Wed Mar 21 2018

Dry weather is expected into next week and river levels will
continue to fall. The Portage River at Vicksburg however, will
remain around flood level into the weekend.


LM...Small Craft Advisory until 8 AM EDT this morning for LMZ844-845.



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