Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 211746

Area Forecast Discussion
National Weather Service Grand Rapids MI
146 PM EDT Wed Mar 21 2018


Issued at 314 AM EDT Wed Mar 21 2018

Expect partly cloudy skies with highs in the 40s and lows in the
20s through Sunday. A large blocking Canadian Polar high pressure
system, centered near southern Hudson Bay will remain in place
through this coming weekend. That will force all storm systems
this week, into this weekend, to track south of Michigan.


.SHORT TERM...(Today through Friday)
Issued at 314 AM EDT Wed Mar 21 2018

No significant weather issues through Friday. Being on the south
edge of a large Canadian Polar high pressure system we will stay
in the cooler air through Friday. We will see mid clouds from the
storm tracking south of the area today into tonight but the sun
should be able to shine through most of those clouds. Once that
storm gets east of the area Thursday skies should become mostly
clear until Saturday.

We remain on the down stream side of a large upper level ridge
through Friday. This will continue to force all Pacific storm
systems to track south of Michigan. Meanwhile our Polar Vortex,
while displaced southward to near Baffin Island, is keeping the
polar air locked north of the Polar Jet, which is currently near
65 north latitude. The southern branch of the polar jet is
largely over the Gulf States. The combination of these to features
will keeps all the polar air in the arctic and the really warm
air over the southern states.

The bottom line is highs in the 40s and lows in the 20s through

.LONG TERM...(Friday night through Tuesday)
Issued at 314 AM EDT Wed Mar 21 2018

Fair wx will continue through the weekend as a high pressure ridge
remains in control of our wx pattern. We will go with a dry fcst for
Saturday through Saturday night in lieu of recent medium range
guidance trends the past 24 hours which now suggest all pcpn with
the TN Valley low pressure system will stay south of our area
Saturday through Saturday night.

Fair wx will continue into Monday and temperatures will undergo a
slow moderating trend this weekend into early next week as southerly
flow develops on the back side of the departing ridge by next
Monday. High temperatures early next week will potentially reach the
50`s. The southerly flow will also result in increasing moisture and
a chance of showers by Monday night through Tuesday.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 145 PM EDT Wed Mar 21 2018

Confidence is very high that VFR conditions will continue tonight
and Thursday. North winds of 10 to 20 knots this afternoon will
diminish to less than 10 kts after 00Z this evening, then
become northwest on Thursday.


Issued at 314 AM EDT Wed Mar 21 2018

We will see our northeast winds slowly turn to the northwest over
the next 24 hours as the storm to our south moves toward the east
coast. Winds and waves will remain below Small Craft Criteria.


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.




LONG TERM...Laurens
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