Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 201801

Area Forecast Discussion
National Weather Service Duluth MN
101 PM CDT Sat May 20 2017

Issued at 1243 PM CDT Sat May 20 2017

Updated aviation section below.

UPDATE Issued at 1143 AM CDT Sat May 20 2017

Did a slight adjustment to the forecast for this afternoon by
slowing down the progression of the rain showers. Current
radar trends have light to moderate rain falling from the
Brainerd Lakes region southeast towards Hinckley and the I-35
corridor. This is a bit slower compared to what was previously
forecast, so adjusted accordingly. Still, this initial band of
precipitation will continue to advance northward through the
afternoon and evening, affecting all of the Northland. Didn`t
make any adjustments to QPF at this time as QPF amounts appear to
be on track.


.SHORT TERM...(Today through Sunday)
Issued at 409 AM CDT Sat May 20 2017

Cloud cover had spread northward across much of the Northland
early this morning. A closed upper low was located over the
Rockies and the western Great Plains with a surface low centered
over northeast Kansas. Poleward moisture transport ahead of the
trough and surface low will increase precipitable water values
across the Upper Midwest to between 0.50 and 1.25 inches by this
afternoon. Rain will spread northward across the forecast area
later this morning and this afternoon, continuing overnight.
Widespread rainfall of up to one inch is expected, with locally
higher amounts possible in northwest Wisconsin. The dry slot is
forecast to lift into northern Wisconsin overnight. Mid-level
lapse rates are expected to steepen slightly and should yield a
marginal ribbon of up to 250 J/kg of MUCAPE. Have added a slight
chance of thunderstorms for interior portions of northwest
Wisconsin tonight. Severe weather is not anticipated, with pea-
size hail possible from the strongest storms.

The trough and surface low will lift northeastward through the
Upper Midwest on Sunday. Cold air advection aloft should continue
the rain chances for the second half of the weekend, but changing
to a more showery rather than stratiform structure. Additional
rain amounts should be lower, up to one-quarter inch.

.LONG TERM...(Sunday night through Friday)
Issued at 409 AM CDT Sat May 20 2017

An upper level low will be over the region Sunday evening, moving
slowly east through Tuesday. Several shortwaves will rotate
around the low and there will be a chance for showers Sunday night
through Tuesday.

The best chance for showers through midweek will be Sunday night
into Monday. We have the highest chances during that time over far
northern Minnesota. Widespread heavy rainfall is not expected.
Highs Monday will range around 50 to 55 in the Arrowhead to around
60 south.

The low will continue east Monday night into Tuesday with the
upper flow becoming more northerly. A chance for showers will
continue and there is some concern coverage may be higher than our
current probabilities. If the models look similar with the next
update, POPS will be increased. Widespread heavy rain again looks
unlikely. Highs Tuesday will be in the lower fifties to lower

Upper ridging will exist to the west Tuesday night moving over
the region Wednesday into Wednesday night. A dry period will occur
Tuesday night through Wednesday night with ridging in place.
Temperatures will warm into the sixties but be cooler around Lake

Although there are timing and strength issues with the pattern
late in the week into next weekend between the GFS and ECMWF, they
both do develop a western CONUS trough. Southerly flow will
develop over the region Thursday with a low pressure system moving
through late in the week into the weekend. Depending on the speed
of the low, significant rainfall could occur as instability
increases. Highs Thursday through Saturday will be mainly in the


.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1243 PM CDT Sat May 20 2017

Low pressure over southwest Iowa is expected to move north-
northeast across Iowa and southern Minnesota to northwest
Wisconsin by 12z Sunday before moving up to eastern Lake Superior
by 18z. Ahead of this low pressure system, rain will spread north
to affect the terminals through 08z tonight with IFR/MVFR
conditions, with potential for LIFR ceilings as well. Visibilities
should improve to MVFR or VFR after 09z as the more intense rain
bands move north of the area. KDLH is the exception, where IFR
visibilities are likely to linger. IFR ceilings will continue
through the end of the TAF period.


DLH  46  37  48  40 /  90  90  60  40
INL  58  39  48  40 /  60  90  70  50
BRD  48  40  50  41 / 100  90  60  30
HYR  52  44  52  41 / 100  80  60  50
ASX  51  39  51  41 /  90  90  60  40


LS...Small Craft Advisory until 10 AM CDT Sunday for LSZ121-140>143-

     Small Craft Advisory until 4 PM CDT this afternoon for LSZ144-

     Small Craft Advisory from midnight tonight to 10 AM CDT Sunday
     for LSZ144-145.

     Gale Warning from 4 PM this afternoon to midnight CDT tonight
     for LSZ144-145.



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