Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 290544
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1144 PM CST Mon Nov 28 2016

.SHORT TERM...(This evening through Tuesday)
Issued at 305 PM CST Mon Nov 28 2016

Vertically stacked low has seen it`s surface low bottom out at
975mb just to the west of Fargo this afternoon. Through tomorrow,
this low will slowly fill as it slides off to the east and by the
end of the short term, we should see a 995mb surface low centered
near Grand Rapids with an surface trough across the arrowhead to
a secondary low near Thunder Bay that will be the result of lift
associated with a strong shortwave currently down in Oklahoma that
will swing up to eastern Lake Superior Tuesday.

Precipitation today has been centered within two areas. Along an
occluded front, which has been straddling the I-35 corridor since
the late morning, and with the main deep moisture feed associated
with the upper low over the Red River Valley that is coming up
across the eastern half of WI. The occluded front won`t move much
through 00z, but will start to surge north after that, reaching a
Grand Rapids to southern Lake Superior line by around midnight.
This boundary will become the surface trough reference above
Tuesday. Through the period, best precip chances are expected east
and north of this occluded front/surface trough and to the west of
the surface low. Tonight, heaviest rain will be seen up in Lake
and Cook counties, where upslope flow from ESE winds coming off
of Lake Superior will lead to orographic precip enhancement along
the north shore. Tuesday, best rain chances are expected across
the international border (north of the surface trough) and out in
the Red River Valley (west of the surface low), with most of the
Duluth area remaining dry. However, low levels will remain moist
and it won`t take much lift to generate drizzle/light rain near
the low, which is why we still 20/30 PoPs across much of the area
Tuesday.

For temperatures, they will just gradually drop during the
period, with cloud cover and CAA keeping temperatures steady in
the mid/upper 30s Tuesday. Tonight, we will have to keep an eye
out for fog formation as the pressure gradient weakens as the
surface low starts to drift east, though the more likely scenario
tonight for the fog is to see the stratus lower down to around 500
feet as opposed to dense fog becoming problematic.

.LONG TERM...(Tuesday night through Monday)
Issued at 305 PM CST Mon Nov 28 2016

Surface low that is over Fargo now, will meander to Grand Rapids
Tuesday and make it to northern Lake Huron on Wednesday. However,
we do not look to clear its cyclonic flow until Friday, so the
mostly cloudy conditions will stick with us for a few more days.
As the low moves across the upper Great Lakes, the deformation
precipitation on the west side of the surface low will be working
across the Duluth area on Wednesday/Wednesday night. However, as
this deformation band arrives, the main moisture feed from this
system will be stretched out from the FL Panhandle to upstate New
York, leaving us a little lacking on the moisture department. As
a result, we are only looking at total QPF of maybe a tenth of an
inch Wed/Wed night. By then, we look to have cooled enough to give
us a mainly snow p-type, but this type of QPF will only translate
to a dusting at best.

For the weekend, not much is expected weather wise as we get into
an upper confluence region to the west of Today`s upper low
remnants. Airmass behind this system will be cool, but with highs
in the lower 30s, we will still be around 5 degrees above normal.

As for the potential weather system in the Sunday night/Monday
timeframe, like the 28.00 runs, the ECMWF still has one and the
GFS does not. However, the ECMWF has the surface low going up
through Cleveland with its 28.12 run as opposed to Milwaukee as it
had with the 28.00 run. It still has a swath of heavy snow to the
west of the low, but as opposed to coming up through WI and
getting near the east side of the Duluth CWA, that heavy snow is
now getting dumped on Michigan. Chance PoPs we have in the east
Monday are influenced strongly by what we had going last night,
but until we see some semblance of agreement between the models,
it`s hard to put much stock in any sort of precipitation forecast
from Sunday and beyond.

Oddly enough though, there is really good agreement between the
GFS and the ECMWF in the extended in one area. For those that are
wondering exactly when it is we will start seeing some cold air,
the answer looks to be the second week of December. Both the GFS
and ECMWF show a significant push of arctic air coming heading out
of Canada then, so enjoy the warmth while you can.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1142 PM CST Mon Nov 28 2016

A large low pressure system will remain largely in place across
the Northland throughout the TAF period. An area of instability
rotated from southwest to northeast across the region during the
evening, and we will continue to see bands of precipitation wrap
around the main upper level low throughout the period. The impact
will be somewhat variable cloud heights and visibilities, with a
mix of VFR conditions as well as MVFR to IFR CIG`s and VSBY`s. We
could see a bit of an improvement on Tuesday, but probably only
improve to MVFR at most sites. Rain showers will also be found
across the region once again.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  37  38  33  37 /  70  40  30  40
INL  37  39  32  35 /  70  80  40  40
BRD  34  38  32  37 /  30  40  30  50
HYR  36  39  32  39 /  80  30  20  40
ASX  39  42  33  39 /  80  30  20  40

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...Small Craft Advisory until 4 AM CST Tuesday for LSZ121-142>148.

     Small Craft Advisory until noon CST Tuesday for LSZ140-141.

&&

$$

SHORT TERM...MPG
LONG TERM...MPG
AVIATION...DAP



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