Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 272005

Area Forecast Discussion
National Weather Service Grand Rapids MI
305 PM EST Sun Nov 27 2016

Synopsis/Short Term/Long Term/Marine

Issued at 305 PM EST Sun Nov 27 2016

A warm front will move into our region early this week and bring
showers and milder conditions Monday. Dry weather will return
Tuesday before a cold front brings potential for more showers
Wednesday. A cooler airmass will move in Wednesday night through
late in the week along with potential for mixed rain and snow
showers late in the week.


.SHORT TERM...(This evening through Tuesday night)
Issued at 305 PM EST Sun Nov 27 2016

Primary short term fcst concerns involve determining probabilities
for showers and timing of showers into our fcst area from early
Monday morning through Tuesday night. A consensus of latest 12Z
shorter range guidance remains in fairly good agreement in suggesting
scattered showers will develop mainly west to southwest of Grand
Rapids around daybreak Monday.

Scattered light rain showers will then continue to develop Monday
morning and afternoon to the north of the approaching warm front.
It will also become breezy as southerly winds increase to around
15-25 mph. Short range guidance consensus continues to suggest
that more widespread/heavier rain will stay well south of Michigan
through Monday afternoon.

The warm front will continue to lift northward through our region
Monday night and bring a period of steadier rainfall from Monday
evening through the overnight period. We cannot completely rule
out an isolated rumble of thunder Monday night but this potential
is very low due to several factors including very weak to no sfc
or elevated instability.

Dry wx returns Tuesday in the warm sector with the warm front well
north of our fcst area by then. We went with a fairly conservative
max temp fcst mainly in the middle to upper 50`s for Tuesday but I
would not be surprised if a few locations see max temp readings
reach the 60 degree mark given some sun and strong south-southwest
flow waa by then.

The sfc low approaching from the west and occluded front will
bring potential for a few showers again late Tuesday night, though
most of the night should be dry.

.LONG TERM...(Wednesday through Sunday)
Issued at 305 PM EST Sun Nov 27 2016

We`ll see a gradual cooling trend through the period, with highs
falling to near normal values in the upper 30s by the weekend.

Low pressure moving across northern Lake Michigan will probably
bring a little rain to the cwa mid week, but the bulk of the pcpn
will already have moved east along with the occluded front. Colder
air will move in later Wednesday behind the front. Lingering rain
showers generated by the trailing upper low will mix with and change
to snow showers Wednesday night over inland areas. Mainly rain is
expected adjacent to the lake shore. Warmer temps Thursday will lead
to scattered rain showers and then the mix develops Thursday night
with temps cool. Troughiness associated with the trailing upper low
will linger through Friday night. Chances for pcpn will diminish by
late friday as the upper low moves away. The weekend looks dry with
seasonable temperatures.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1231 PM EST Sun Nov 27 2016

17z neph analysis shows abundant IFR conditons across SW Lwr MI.
JXN however is VFR and will likely remain that way as vis loop
shows clouds south of JXN thinning out. Elsewhere IFR/MVFR is
expected througout the afternoon.

An occluded front will push into Lwr MI tonight and we`ll see cigs
rise to VFR. Some light rain is possible after 10z across wrn LWR.


Issued at 305 PM EST Sun Nov 27 2016

A small craft advisory remains in effect from tonight through
Monday night. Southerly winds will increase to 20 to 30 kts late
tonight through Monday into Monday night. This will cause wave
heights to ramp up to 3 to 6 feet tonight and to 4 to 8 feet
Monday into Monday night. The highest wave heights within that
range will occur near to mainly north of Holland.


Issued at 305 PM EST Sun Nov 27 2016

The latest 48 hour QPF being used for the RFC forecasts would bring
a few forecast points above bankfull if all the rain materializes.
This would include the Grand River at Ionia, Maple River at Maple
Rapids, Looking Glass River at Eagle, and the Sycamore Creek at
Holt. Trends will be monitored with future river forecast updates.
This rain would likely boost numerous locations from the 70th and
80th percentiles to perhaps the 90th percentile or even max for this
time of year, compared to climatology. That said, significant
flooding looks quite unlikely. In general, expect river rises within
banks for many locations and perhaps out of banks for the harder hit


LM...Small Craft Advisory from 7 PM this evening to 7 AM EST Tuesday
     for LMZ844>849.



SHORT TERM...Laurens
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