Area Forecast Discussion
Issued by NWS Duluth, MN
FXUS63 KDLH 142104
Area Forecast Discussion
National Weather Service Duluth MN
404 PM CDT FRI OCT 14 2016
.SHORT TERM...(This evening through Saturday)
Issued at 404 PM CDT Fri Oct 14 2016
The Northland will continue to get breezy southerly flow through
tonight as an area of low pressure in south central Canada moves
east through southern Saskatchewan and into Manitoba. Its cold
front will also move into the northern Plains and begin to
approach northeast Minnesota early Saturday.
Low-level stratus has been advecting northward from Iowa into
southeast Minnesota and western Wisconsin today, and is expected
to surge northward into the Northland this evening. By later this
evening or the wee hours of the morning, much of eastern and
central parts of the Northland should be under an overcast stratus
layer, while broken/overcast upper-level cloud cover will spread
over the Northland due to the approaching low pressure. The
extensive cloud cover, increasing dew point temperatures, and
breezy winds will combine to bolster the overnight temperatures.
Overnight lows should only be in the middle to lower 50s.
Some models are indicating the stratus layer may be thick enough
to produce some very light drizzle overnight into Saturday
morning, including the NAM, SREF, WRF ARW and NMM, and GFS. Kept
some chances for drizzle, with the higher chances Saturday
The cold front will work its way through northeast Minnesota
Saturday morning and afternoon, which will also help to produce
some light rain near and ahead of the front. The front will begin
approaching northwest Wisconsin Saturday afternoon. The NAM and
SREF are suggesting there could be enough elevated instability to
create some thunder across parts of northwest Wisconsin in the
afternoon, especially if there are any shortwaves that lift
through the area, a possibility.
Meanwhile, it looks like skies will clear in the wake of the
passing front during the afternoon, so some of the warmest
temperatures should be across the west due to afternoon sunshine.
Highs will range from the lower to middle 60s.
.LONG TERM...(Saturday night through Friday)
Issued at 404 PM CDT Fri Oct 14 2016
The main concerns for the long range are precipitation chances
Sunday night through Tuesday morning and subsequent cool down next
Deterministic guidance is in relatively good agreement with
departing shortwave trough Saturday evening. The general consensus
shows this feature stretching from far northwest Ontario southwest
into central Minnesota. This progressive feature will quickly
advance eastward to northeast Ontario through eastern Upper
Michigan and eastern Wisconsin by 06Z. Precipitation should end
quickly Saturday evening with only low chance POPs lingering after
16.00Z over my southeastern-most zones.
The break will be short-lived as sharp ridging quickly gives way
to the next approaching shortwave on Sunday. Lee cyclogenesis will
accompany the trough as it crosses the Canadian Rockies. Surface
low pressure is forecast to develop over southern Alberta, and
move eastward into southern Saskatchewan by Sunday evening. A
nascent warm front will move northeast across the Plains and into
the Upper Midwest by early Sunday afternoon. Showers will be
possible along and north of the boundary as it moves into northern
Minnesota, mainly affecting my far northwest areas by 17.00Z. The
low will begin to occlude Sunday night as a cold front marches
across the Dakotas and into western Minnesota Sunday night into
Monday. Rain chances quickly increase as the cold front approaches
Sunday night and early Monday. Continued thunder mentions along
the southern extent of the cold front.
The cold front will stall over Wisconsin, southern Minnesota, and
southern South Dakota Monday evening. Another shortwave trough
will move across the Rockies along the southern periphery of the
stalled upper low over the Canadian Prairies. A compact surface
low should develop Monday evening in the western Dakotas and track
eastward overnight, lifting the boundary northward once again as a
warm front. Another round of showers and thunderstorms seems
likely for portions of the Upper Midwest as that system moves
through late Monday night and Tuesday.
The smaller shortwave should be sufficient to kick the stagnant
upper low eastward Tuesday night and Wednesday with quasi-zonal
flow developing. Deterministic solutions diverge once again late
next week with the ECMWF and GEM featuring a progressive longwave
trough moving through the region, while the GFS establishes a
split-flow regime with a cutoff low near the Four Corners.
Confidence in sensible weather diminishes quickly with the drastic
split in solutions. The progressive trough would continue the
trend toward unsettled weather for the latter half of the week,
while the cutoff upper low would keep a stout ridge of high
pressure parked over Ontario and the Upper Midwest.
Temperatures will trend near to much above normal across the
Northland Sunday through Tuesday, trending near to slightly below
normal behind the third system on Tuesday night. The change may
not be especially noteworthy since minimum temperatures will trend
as much as 20 degrees above average for middle October Saturday
night through Monday night, before trending cooler Tuesday night
through the end of the period.
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 113 PM CDT Fri Oct 14 2016
VFR conditions continue this afternoon with MVFR, and eventually
IFR/LIFR, developing tonight and continuing into Saturday morning.
South to southwesterly flow ahead of an approaching storm system
will draw moisture northward into the area late this afternoon and
tonight. Satellite and surface observations over southern
Minnesota, Iowa, and farther south feature an area of MVFR/IFR
ceilings being drawn northward toward the area. Expect a period of
MVFR ceilings and visibility to arrive by this evening, with
ceilings continuing to lower to IFR a few hours later. NAM model
BUFKIT profiles suggest the low-level moist layer will be deep
enough, with enough shear aloft, to support drizzle overnight.
Ceilings at DLH, HYR, and HIB may continue to lower into LIFR
between 06Z and 12Z. Was not confident in that potential to
include at this time. As winds aloft increase overnight, low-
level wind shear will become a concern at HYR, where the strongest
winds aloft will be found. All sites should see periods of gusty
winds overnight. Think ceilings will lift back to MVFR Saturday
morning, but confidence is below average in CIGS lifting before
cold front arrives from the west. Confidence is above average
through 15.02Z, average between 15.02Z and 15.09Z, and below
.PRELIMINARY POINT TEMPS/POPS...
DLH 53 65 44 60 / 40 40 0 10
INL 52 64 39 58 / 10 10 0 20
BRD 56 68 44 64 / 20 10 0 10
HYR 56 66 44 66 / 40 40 10 10
ASX 55 66 47 63 / 10 30 10 0
LS...Small Craft Advisory until 10 AM CDT Saturday for LSZ140.
Small Craft Advisory until 4 AM CDT Saturday for LSZ141.