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Area forecast discussion
National Weather Service Gaylord Michigan
324 PM EDT Mon Sep 23 2019

Near term...(through tonight)
issued at 317 PM EDT Mon Sep 23 2019

High impact weather potential: none

Pattern synopsis and forecast:

Wrap around moisture and an upper level trough is continuing to
produce shower chances across northern Michigan with gusty
westerly winds. Gusts of up to 25 mph can be expected. The better
chances of precipitation is slowly moving to the east as the upper
level trough makes it's way through the forecast area and takes
the deeper moisture (pwat values near an inch) and better
instability with it. There have been a few rain reports of around
a half an inch falling since midnight, but the majority of reports
are below 0.20". High pressure and drier air will finally build
back into the area late tonight into the morning hours...bringing
a return to precipitation free weather after midnight. The gusty
west-northwest winds will diminish in intensity during the late
afternoon/early evening hours before becoming light and variable
during the overnight hours as said high pressure builds into the
forecast area. Temperatures are remaining steady in the upper 50s
to low 60s and lows will drop into the upper 40s to near 50


Short term...(tuesday through thursday)
issued at 317 PM EDT Mon Sep 23 2019

..warmer Tuesday, showers Wednesday...

High impact weather potential: slight chance for some thunderstorms
late Wednesday night.

A deamplifying 500mb shortwave ridge will cross northern Michigan Tuesday.
An upper low migrates to western Hudson Bay, deepens and stalls. An
initial shortwave pushes into northern Michigan from the west late Tuesday
night. At the surface, low pressure deepens near James Bay
Wednesday, with an associated cold front crossing northern Michigan Wed
morning. Tuesday looks warm and pleasant, but showers and a few T-
storms enter the picture from the west beginning late Tue night.

Surface ridging sits over lower Michigan to start Tuesday, but folds over
to our se during the day. That will allow return SW low-level flow
to develop, and an associated warm front will lift into northern
lower Michigan in the afternoon. Low-level moisture will be on the
increase as warm advection ramps up, so cloud cover will increase
(especially in western sections) in the PM. A marine contribution to
cloud cover is possible in eastern Upper Michigan as we warm/moisten, but
moisture isn't deep enough (thru 800mb) for precip (except maybe
some drizzle). No mention of precip during the day. Max temps in the
upper 60s to lower 70s. Will be some mid 70s in places that see
downsloping with a S/SW breeze, like tvc.

Tue night-Wed...organized showers/storms expected to develop to our
west late Tuesday, where the cold front encounters healthy
instability with favorable diurnal timing. Though forcing remains
respectable with the incoming shortwave and cold front late Tue
night/Wed morning, our diurnal timing is clearly unfavorable. DPVA
forcing looks to be sharpest in the north half of the forecast area,
and progged quantitative precipitation forecast values are highest there (0.25 to 0.75"). Have a
chance of showers arriving in eastern upper and the NW lower Michigan
coastal counties close to midnight. Pops increase to likely in those
same areas overnight, Chancy elsewhere. Highest pops Wed morning -
likely in most of northern Michigan - with fropa itself. Wraparound
moisture will sustain a shower threat into the afternoon, especially
in eastern upper. With instability seriously waning with eastward
extent, only a slight chance for thunder is warranted late Tuesday
night into the start of Wed. A relatively mild Tue night in the warm
sector, with lows in the mid 50s to lower 60s. Highs Wed in
the upper 60s to lower 70s.

Wed night-Thu...low pressure lifts northward from James Bay to
Hudson Bay. High pressure will quickly scoot eastward from the
Central Plains to the Northern Ohio valley/southern lakes. Lingering
wraparound moisture will support some showers into Wed evening, but
otherwise we will tend to dry out as deeper moisture lifts
northward. Eastern Upper Michigan will have more cloud cover than northern
lower Michigan thru these periods. Min temps mid 40s to lower 50s. Max
temps near 60f to the mid 60s.


Long term...(thursday night through monday)
issued at 317 PM EDT Mon Sep 23 2019

Relatively fast and low-amplitude flow will be in place across the
northern US late this work week. Eventually, energy diving into the
NW states will carve off an upper low out that way, with
corresponding ridging building in the east. Despite this, high
pressure to our north will tend to funnel cool air into the region
on easterly winds at low levels. That will keep temps relatively
close to climo.

A well-defined shortwave looks to cross the region at the end of the
week, with showers likely as soon as late Thu night lasting into Fri
night. Enough uncertainty with how the pattern and individual waves
play out to support some slight chance pops over the weekend.


Aviation...(for the 18z tafs through 18z Tuesday afternoon)
issued at 142 PM EDT Mon Sep 23 2019

Upper level low/trough axis continues to swing through northern
Michigan, producing showers and mostly MVFR ceilings across all
northern lower Michigan taf sites. Shower chances will end early
this evening as this feature slides east of our area. High
pressure and drier air will build in overnight... resulting in
diminishing cloud cover. West-northwest winds will continue to gust
to 10 to 20 kts this afternoon...and will diminish tonight as
high pressure moves in overhead. Winds Tuesday will be very light
out of the southwest.


issued at 317 PM EDT Mon Sep 23 2019

Winds and waves will diminish within all of our nearshore areas
during the late afternoon/early evening hours as an upper level
low pressure departs eastward and makes way for high pressure.
Rain showers will also move off to the east with said upper level
low during the early evening hours. As high pressure builds in
winds will be light Tuesday as aforementioned high pressure builds
overhead. Southwesterly winds will once again be gusty with
possible headlines Wednesday ahead of an approaching cold front
from the west.


Apx watches/warnings/advisories...
LH...Small Craft Advisory until 8 PM EDT this evening for lhz345.
Small Craft Advisory until 2 am EDT Tuesday for lhz346>349.
Lm...Small Craft Advisory until 8 PM EDT this evening for lmz323-341-
Ls...Small Craft Advisory until 8 PM EDT this evening for lsz321-322.



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