Area Forecast Discussion
Issued by NWS Duluth, MN

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167
FXUS63 KDLH 281732 AAB
AFDDLH

Area Forecast Discussion...UPDATED
National Weather Service Duluth MN
1232 PM CDT Fri Apr 28 2017

.UPDATE...
Issued at 1232 PM CDT Fri Apr 28 2017

Update for the new 18Z Aviation Discussion below.

&&

.SHORT TERM...(Today through Saturday)
Issued at 331 AM CDT Fri Apr 28 2017

Quieter weather expected today, with the strong low from the past
2 days now well off over eastern Ontario, and only lingering
cyclonic flow to keep mostly cloudy skies and some snow showers
going during the day today. The steep low level lapse rates will
be enhanced by some weak shortwaves to aid the snow shower
development. Have kept pops pretty low as confidence in coverage
and placement is pretty low. The clouds will keep temperatures on
the cool side once again, with highs only in the mid 30s to mid
40s. Tonight a clearing trend can be expected, with the main
question being timing, which in turn affects how cold we will get.
Have nudged temperatures down somewhat, getting into the teens to
low 20s over much of the Arrowhead. Saturday temperatures finally
begin recovering back towards normal values, but will still be 5
to 10 degrees below normals for this time of year. Sunshine will
favor warmer temperatures, but the north flow and lingering cold
air advection are less favorable. Highs should get into the mid
30s to mid 40s.

.LONG TERM...(Saturday night through Thursday)
Issued at 331 AM CDT Fri Apr 28 2017

Saturday night and much of Sunday morning will be dry across the
Northland, thanks to some remaining low-amplitude mid-level
ridging. However, clouds will be on the increase ahead of a
potentially significant storm system that is slated to advance
through the region Sunday afternoon through Tuesday morning.

This system will be supported by a large mid- to upper-level
longwave trough, which will bring deep lifting with it, as
indicated by progged upper-level divergence and mid-level
isentropic upglide. The associated sfc low pressure center will
track from the OK/AR region early Sunday morning, towards the
central and northern portions of Wisconsin by Monday evening.
Moisture appears to have increased from previous model runs, with
Pwat values over Price and Sawyer counties over 1 inch, according
to the 28.00z GFS. The overall consensus of the synoptic models is
to lift the precipitation shield north by Sunday afternoon as the
inverted trough of the sfc low moves overhead, with the heaviest
precipitation being Monday morning and into the afternoon. The
cyclonic circulation around the sfc low will help to bring
northeasterly winds over the region, which will be favorable for
stronger gusts, especially along adjacent locations of Lake
Superior. The 28.00z GFS/NAM model soundings continue to indicate
that the primary precipitation types associated with this system
will be a rain/snow mixture. However, some freezing rain or sleet
can`t be ruled out at this point, especially Sunday night and
Monday morning. Guidance is starting to lock onto snow
accumulation amounts, but there is still much uncertainty with
these amounts, so it`s a bit too early to mention specific snow
amounts. However, several inches of accumulation will be possible.
At this time, the SREF ensemble snow probabilities are indicating
the corridor of the most likely snow accumulation will be from
the Brainerd Lakes area, northeast towards the Iron Range.
Moreover, the heaviest QPF amounts are expected to fall Monday
morning, which will make for a messy Monday morning commute. Those
with travel plans for late Sunday and Monday will want to stay
tuned for future updates. Chances of precipitation with this
system will linger over the western Lake Superior area through
Tuesday morning as the sfc low pressure center lifts northeast.

Beyond Tuesday, the weather looks to dry up through Wednesday as
subtle mid-level ridging moves overhead. The GFS/ECMWF/CMC models
appear to disagree with possible chances of precipitation for
Wednesday, so just leaned towards the consensus blends POPs for
now. Temperatures look to rebound through the rest of the week as
sfc high pressure develops over Ontario Canada, and brings in some
warm air advection on southerly return flow.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1232 PM CDT Fri Apr 28 2017

Stratus associated with departing area of low pressure lingers
over the Minnesota Arrowhead and portions of northwest Wisconsin
early this afternoon. Think cloud cover will continue the
decreasing trend with ceilings trending higher through afternoon.
Exception may be at INL where strong cyclonic flow aloft is
producing widespread snow showers across portions of northwest
Ontario. A few snow showers may rotate near INL this afternoon
along with VFR ceilings. Winds should remain gusty, but slowly
weakening by evening. An axis of stronger winds aloft will weaken
and pull northeastward through this evening draining the reservoir
of higher momentum over the area. Winds may become light and
variable overnight as a surface ridge approaches from the west. As
the ridge passes through the region, look for VFR conditions to
continue Saturday.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  44  26  48  30 /  10   0   0  10
INL  42  20  53  28 /  20   0   0   0
BRD  47  25  54  32 /   0   0   0  10
HYR  47  24  51  32 /   0   0   0  10
ASX  45  26  47  29 /  10  10   0  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&

$$

UPDATE...Huyck
SHORT TERM...LE
LONG TERM...JTS
AVIATION...Huyck



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