Area Forecast Discussion
Issued by NWS Gaylord, MI

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FXUS63 KAPX 210025
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
825 PM EDT TUE SEP 20 2016

.SHORT TERM...(This evening and overnight)
Issued at 333 PM EDT Tue Sep 20 2016

...Quiet tonight, increasing precip chances Wednesday onward...

High impact weather potential: Thunderstorm chances increase
Wednesday, no severe storms anticipated.

Overview: A somewhat zonal flow pattern is in place across the
northern CONUS with a strong upper jet streak stretching along the
U.S./Canadian border and northern lakes region and a tightening
W-E baroclinic zone south of the jet across the Northern Plains
into the Great Lakes. Loosely organized surface low pressure is
present across the front range of the Rockies with a developing
warm front stretching eastward through the Midwest. Some ongoing
showers (and some thunder) north of the warm front advancing
across Minnesota into Wisconsin, although precip does appear to be
weakening as it approaches a much drier/stable regime downstream.
But associated cloud cover is starting to push into the northern
parts of the CWA.

Tonight and Wednesday: Quiet weather for us overall tonight as
high pressure gradually drifts off through the eastern lakes
region. Then, aforementioned upstream warm front will further
tighten and nose into the northern Great Lakes late tonight
through the day Wednesday with deep moisture pooling up along the
front from the plains into the Great Lakes. This will become the
multi-day focus for several rounds of showers/storms across the
upper Mississippi River Valley and into northern Michigan.
Pattern has some earmarks for a heavy rain event, stalled W-E
front/deep moisture pooling along the front with PWAT values
running 1.5 to 2 inches, although better chances for heavy rain
will be back through Wisconsin/Minnesota/Iowa where better
instability will be found.

.LONG TERM...(Wednesday through Tuesday)
Issued at 333 PM EDT Tue Sep 20 2016

High Impact Weather: Significant rain for Wednesday into Thursday
night with locally heavy

(9/21)Wednesday night and (9/22)Thursday...Main concern is that with
the training echoes expected and the high Pwats, that locally heavy
rain is possible in portions of the forecast area. This concern is
born out of the developing warm/stationary front with the nearly
unidirectional flow up through 150 mb. Models showing that the
heaviest rain should be farther west in Wisconsin and Minnesota
nearer the sfc low, but there is some low chance for something
heavier here. The Pwats during this time is at or above 1.5". The
main thing that would cause flooding, and more rain that is expected
is if the warm front were to stall and allow the rain to train over
the same area. At this point, the models are somewhat different on
the location of the front, and allow it to meander a bit.

After 00z/Thurs, the sfc high begins to force the front south and
the dry air begins to move into E Upper overnight. The 500 mb jet
streak also begins to move east, and the forcing begins to diminish.
So will expect that the rain will begin to diminish as well.

(9/23)Friday...The sfc high continues to push things south. The GFS
really clears things out, while the ECMWF is slow to move the rain
out of the forecast area. Will allow the high to push most of the
rain out of the forecast area.

JSL

High pressure centered over Ontario should help to keep things clear
for the weekend, with a cold front arriving early in the week
bringing a chance for some widespread rains. Temperatures will
remain near to slightly above normal, in the mid to upper 60s
through the period. H8 temperatures behind the cold front could be
cold enough to support some lake enhanced clouds and/or showers
behind the front.

Mayhew

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 823 PM EDT Tue Sep 20 2016

VFR conditions expected with slowly lowering cigs in intial stages
of top-down saturation regime. Cigs may lower enough Wednesday to
kick off some showers, particularly during the afternoon hours.
Will tentatively cover with vcsh wording. Light winds through the
forecast.

&&

.MARINE...
Issued at 333 PM EDT Tue Sep 20 2016

Some gustier westerly winds will be persist into the early evening
hours across the northern lakes region. But small craft advisory
gustiness appears to have ended at this juncture and plan to allow
SCA`s to expire on schedule. Winds/waves will remain below any
headline criteria through the middle part of the week.

Weather-wise: precip chances increase steadily Wednesday and
Wednesday night.


&&

.APX Watches/Warnings/Advisories...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...Adam
LONG TERM...JSL/Mayhew
AVIATION...MSB
MARINE...Adam



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