Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 290933
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
433 AM CDT THU SEP 29 2016

.SHORT TERM...(Today through Friday)
Issued at 432 AM CDT Thu Sep 29 2016

Stratus is the main concern for the next 24-36 hours, along with
associated temperatures.  An upper low over the lower Ohio river
valley this morning is expected to remain there through tonight
before wobbling back in our direction on Friday. Surface riding over
the area early this morning along with light winds and an inversion
are keeping the stratus in place over the forecast area.  Models do
not handle this well in general, but looking at the low level RH
progs and model soundings along with personal experience I expect we
will still have stratus over the area for most of today, though some
improvement will likely be found in the afternoon, mainly over
northwest Wisconsin and perhaps towards the Brainerd Lakes region.
The surface ridge shifts slowly east today and tonight, and by this
evening we should see some clearing on the western flanks of the
cloud cover, which may get into the western portions of the forecast
area tonight.  Northeast convergent flow off Lake Superior as well
as the relatively warm lake is going to help generate clouds over
the southern third of the forecast area tonight, with stratus
spreading back southwest again.  For now have it spreading all the
way to Brainerd, but do not have the greatest of confidence in this
and have allowed cloud cover percentage to lower into the 60-70
percent range overnight and early Friday morning.  However, mixing
should help get rid of the stratus on Friday, even as the upper low
begins to move in our direction again and move upper clouds closer.
This cloud cover is going to have moderating effects on
temperatures, with cooler highs and warmer lows.  Have made some
minor adjustments to previous forecast though we may need to make
additional changes as cloud cover trends become better defined.

.LONG TERM...(Friday night through Wednesday)
Issued at 432 AM CDT Thu Sep 29 2016

Initially in the extended the main focus will be on the cutoff low
retrograding from the Ohio River Valley into southern portions of
the central Great Lakes. All while high pressure continues to nudge
its way into northern MN. Good agreement from the latest
ECMWF/GFS/GEM with the stacked system moving northeastward from the
central Great Lakes into New England early next week. As the low
departs, high pressure will gradually build eastward into the
central Great Lakes, while a trough digs and deepens across the
western US into the Plains. Ahead of the trough a low will develop
in the Northern Plains and spread showers and storms chances into
the Northland late Tuesday through Thursday.

Light easterly/northeasterly flow will continue through the weekend
into early next week across the Northland due to the cutoff. Kept
low chances of precipitation across eastern portions of northwest WI
on Saturday as the stacked system moves northward into the central
Great Lakes. Highs through the weekend and on Monday will be in the
60s with lows in the 40s. Due to run to run trends, delayed the
onset of precipitation, so removed precipitation chances on Monday
and gradually increased chances Tuesday afternoon into Wednesday.

Expect slightly warmer temperatures on Tuesday as strong southerly
warm air advection occurs at 850 hPa ahead of the low developing in
the Northern Plains. Highs will be right around 70 degrees
throughout much of the Northland. Shower and thunderstorm chances
increase from west to east Tuesday into Wednesday as the low
pressure system moves eastward. Guidance continues to show cooler
air wrapping around the system as it lifts into Ontario late in the
week. This will bring cooler readings on Thursday with highs in the
50s across NE MN. The cooler air will continue to wrap around the
low, which will bring near to below 0 degrees Celsius 850 hPa
temperatures Friday into Saturday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1240 AM CDT Thu Sep 29 2016

High pressure will cover the terminals through the forecast. Mainly
VFR is expected. However, some MVFR ceilings are possible at HYR as
low clouds develop over Lake Superior and drift overhead. Opted to
bring radiation fog into KHYR due to clear skies, light winds and
recent precipitation. Think the NCAR ENSEMBLE has the best handle
on the situation per the latest observations. Expect fog to bring
visibility down to MVFR/IFR at KHYR with lower possible, still
uncertain how low visibilities will get especially if clouds drift
into KHYR. Will need to keep a close eye on overnight.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  59  47  63  47 /   0  10  10  10
INL  60  42  66  44 /   0   0   0   0
BRD  63  45  67  47 /   0   0   0   0
HYR  63  44  67  48 /   0   0   0  10
ASX  60  46  63  49 /  10  10  10  10

&&

.DLH Watches/Warnings/Advisories...
WI...None.
MN...None.
LS...None.
&&

$$

SHORT TERM...LE
LONG TERM...WL
AVIATION...GSF/WL



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