Area Forecast Discussion
Issued by NWS Duluth, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
506
FXUS63 KDLH 151750
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1150 AM CST Sun Jan 15 2017

.SHORT TERM...(Today through Monday)
Issued at 400 AM CST Sun Jan 15 2017

An upper level trof was moving through northern Minnesota at
0730Z/130am. A very dry atmosphere is in place over the forecast
area with high pressure centered over southeast Minnesota. The
only thing the trof could generate was a patch of cirrus near the
Canadian border.

The upper trof washes out by 18Z/12pm. The surface high center
drifts to southern Wisconsin. May see a few more clouds along the
Canadian border, but no precipitation. On the backside of this
high, warm air advection begins and 850mb temps rise to 0C over
northwest Wisconsin to 2C over the western edge of the forecast
area. Max temps will be in the 20s.

A quasi-zonal flow covers the region tonight with weak warm
advection continuing. The surface high remains in the vicinity of
southern Wisconsin tonight. Low temps will be in the single digits
above zero, with 10 to 15 near Lake Superior.

On Monday, upper level and surface ridging cover the region.
However, a closed upper low will move from the Oklahoma panhandle
to northwest Missouri. This will send a surface low, which is
vertically stacked with the closed low, into northwest Missouri. A
shield of precipitation will lift northward from this system
toward the far southern edge of the forecast area late Monday
afternoon. The NAM is the only model that brings any into the area
and was ignored. Used a compromise of the other models which kept
the region dry on Monday. Max temps will be a bit warmer with
upper 20s to lower 30s.

.LONG TERM...(Monday night through Saturday)
Issued at 400 AM CST Sun Jan 15 2017

Three main concerns during the long term are the early week
system with potential for wintry mix, much above average
temperatures for the rest of the week, and a potential for
precipitation Friday night into next weekend.

Models have shifted a bit farther south with the track of the
early week system and a more progressive pattern with the 15.00Z
and 15.06Z deterministic and ensemble runs. Cutoff upper low is
still forecast to lift northeastward from the Big Bend region of
Texas today to near Kansas City, MO by Monday evening and then
east- northeast to near Buffalo, NY by Tuesday night. A northern
stream shortwave trough will cross the northern Rockies and move
into the Dakotas Monday morning and then dig into the Central
Plains Monday night and Tuesday. The northern stream trough is a
little slower this morning and is expected to kick the upper low
eastward rather than phasing with. The more progressive cutoff low
featured by this morning`s guidance would result in less
precipitation for the Northland with the best forcing located over
southern Minnesota and central and southern Wisconsin. GFS and NAM
favor a more easterly track with a shorter duration precip event,
and therefore less QPF overall. ECMWF/GEM still bring a robust
band of precip into Washburn, Sawyer, and Price Counties Monday
night. Given the uncertainty in timing, location, and intensity,
there is still a potential for a mix of snow, sleet, or freezing
rain Monday night through late Tuesday morning for interior
portions of northwest Wisconsin. Interestingly the 15.00Z NAM was
warmest and produced a longer period of freezing rain or sleet
from a Hayward to Bayfield line and eastward. The 15.06Z run,
however, shunts precip farther east along with the warmer
temperatures aloft. Not sold on this change just yet, but if the
15.12Z runs continue the cooler and eastward trend, the potential
for mixed precip would effectively drop to zero. Trended POPs a
bit lower Monday night and Tuesday, in the direction of the
consensus but not quite as aggressive as a straight CONS blend.
With the northern stream shortwave still offshore west of British
Columbia and Washington state as of 15.00Z, another shift in the
forecast is possible after then 15.12Z soundings sample the
disturbance.

The progressive pattern aloft brings another northern stream
shortwave across the Canadian Prairies and Northern Plains Tuesday
night and Wednesday. The GFS is most aggressive with this feature
and would support a slight chance of snow showers or flurries late
overnight into mid-morning Wednesday. As the complex upper trough
finally pushes east of the region Wednesday night, a high
amplitude ridge will build into the Plains and the Midwest
resulting in a period of quieter weather and warmer temperatures.
High temperatures will rise above freezing in northwest Wisconsin
as early as Tuesday afternoon, with highs in the low to upper 30s
across the Northland Wednesday. There may even be a few 40s
Thursday and Friday. There is still a slight chance of another
storm system moving into the area Friday through next weekend. The
GEM, GFS, and ECMWF all feature a shortwave trough or cutoff low
developing in the Southern Plains or Lower Mississippi Valley on
Friday, but the subsequent evolution of that feature diverges
considerably. The GEM pushes the upper low east across the Deep
South while the GFS and ECMWF have flavors of a digging trough
lifting into the Northern Plains and Upper Midwest Friday night
and Saturday. The GEM solution would keep us mild and dry, while
the GFS or ECMWF trends would suggest a chance for precipitation.
Continued with consensus approach as there was no strong signal
favoring any of the potential solutions.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1150 AM CST Sun Jan 15 2017

Generally expecting VFR conditions through the forecast. High
pressure will remain southeast of the region, while a trough axis
swings through Ontario. This will bring low level wind shear to
KHIB/KINL. Further south the threat is more marginal per the
latest GFS/NAM/RAP. Expect the wind shear threat to diminish this
evening as the trough moves into Quebec.

Late tonight into early Monday, there still appears to be a threat
of low level stratus developing around 500-1000 feet per the
GFS/NAM/DLHWRF and RAP. Leaned more heavily on the GFS for the
timing of the stratus development. Kept in as a scattered layer as
uncertain how widespread the development will be. Also held off on
low visibilities.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  27  12  28  19 /   0   0   0  20
INL  26   8  26   6 /   0   0   0   0
BRD  26   9  28  17 /   0   0   0  10
HYR  29  10  32  23 /   0   0  10  50
ASX  29  14  33  22 /   0   0   0  40

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...Small Craft Advisory until 10 PM CST this evening for LSZ142>144-
     146-147.

     Small Craft Advisory until 4 AM CST Monday for LSZ140-141.

&&

$$

SHORT TERM...GSF
LONG TERM...Huyck
AVIATION...WL



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.