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fxus63 kgrr 141927 
afdgrr

Area forecast discussion
National Weather Service Grand Rapids Michigan
327 PM EDT Mon Oct 14 2019

Latest update...
synopsis/discussion/marine

Synopsis...
issued at 327 PM EDT Mon Oct 14 2019

-cold/frosty night in store

-showers return for Tuesday into Wednesday with another strong
Fall storm system.

-Windy Wednesday, highest gusts along the Lakeshore. Gale force
winds leading to 8 to 12 foot waves and further beach erosion

-milder weather for week's end; another strong Fall storm
possible next Monday

&&

Discussion...(this evening through next monday)
issued at 327 PM EDT Mon Oct 14 2019

Will maintain the frost advisory as is, although latest guidance
suggests an increase in mid and high level cloudiness tonight
related to the incoming warm advection ahead of the next system.
Depending on how thick/extensive these clouds become, as well as
how quick they arrive, could limit frost potential.

Otherwise main focus is on the next digging upstream upr trough
which induces a deepening sfc low over the nrn grtlks rgn Tuesday
and Wednesday. Initial impacts will be showers arriving Tuesday,
with isolated non-severe tstms possible Tuesday afternoon/evening
ahead of the cold front. About 500 j/kg of MUCAPE is about all we
can muster ahead of the front per href guidance, mainly south of
I-96, with sfc instability unlikely.

Main impacts arrive Wednesday on the back side of the deepening
sfc low over Georgian Bay. Windy conditions can be expected, and
even the possibility for some gusts near Wind Advisory criteria
(45 mph) along the Lakeshore. This could result in a few power
outages.

After a brief dry period behind the front Tuesday evening, rain
showers should become numerous again late Tuesday night and
Wednesday, especially near/west of Hwy 131, given projected deep
moisture under system deformation zone, lake enhancement with 800 mb
temps near -2c, and no substantial inversion aloft seen in the
soundings. Not forecasting any snow at this time due to mild sfc
temps, although heavier convective bands could briefly bring down
enough cold air to get a few reports of snow/graupel mixed in.

This is not a big rain maker by any means, with system rainfall
totals generally on the order of around one quarter inch. Some
locations near/west of Hwy 131 could push one half inch however
depending on where the better NW flow lake effect bands set
up/persist.

Lake effect clouds and a few showers may linger into early
Thursday, then a skinny sfc ridge gives another frost risk on
Thursday night. Milder trend expected for the end of the week and
next weekend before another potential strong Fall storm moves into
the wrn grtlks rgn a week from now.

&&

Aviation...(for the 18z tafs through 18z Tuesday afternoon)
issued at 200 PM EDT Mon Oct 14 2019

VFR conditions will continue through 18z Tuesday. The lake effect
clouds currently blanketing the region have bases between 3500 and
6000 ft. These clouds will scatter out across the majority of the
area after 21z leaving mostly clear skies. Exception will be at
mkg where the lake clouds could linger as late as midnight before
low level winds turn offshore/south-southeasterly.

Some mid and high level clouds may move in after midnight
tonight with bases above 12,000 ft. Cloud cover increases
Tuesday, but bases should remain above 5000 ft through 18z. The
outlook beyond 18z Tuesday is for lower MVFR cigs and showers to
arrive from the west.

West sfc winds around 10 kts diminishing tonight and becoming
light southerly. Winds Tuesday increasing out of the southeast to
12-22 kts with some higher gusts in the afternoon.



&&

Marine...
issued at 327 PM EDT Mon Oct 14 2019

While a brief period of more tranquil conditions is expected over
Lake Michigan tonight, we have more hazardous marine weather
arriving Tuesday and continuing on Wednesday as a deepening low
pressure system tracks across The Straits of Mackinac.

Initially the hazard will be the increasing south- southeast
winds on Tuesday, with the more impactful event arriving late
Tuesday night behind the cold frontal passage. Northwest gales up
to 40 kts appear likely Wednesday which will also lead to further
beach erosion and excessive/dangerous pier over-wash.

Will have a Small Craft Advisory starting noon Tuesday, ramping up
into a gale watch which starts at 5 am Wednesday. Lakeshore flood
headlines may be needed again as well to cover the erosion
aspect.



&&

GRR watches/warnings/advisories...
Michigan...frost advisory from 2 am to 8 am EDT Tuesday for miz037>040-
043>046-050>052-056>059-064>067-071>074.

Lm...gale watch from late Tuesday night through Wednesday evening for
lmz844>849.

Small Craft Advisory from noon Tuesday to 5 am EDT Wednesday for
lmz844>849.

&&

$$

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