Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 270515

Area Forecast Discussion
National Weather Service Duluth MN
1215 AM CDT Mon Mar 27 2017

.SHORT TERM...(This evening through Monday)
Issued at 251 PM CDT Sun Mar 26 2017

A mid-level shortwave, with an associated sfc low, will advance
across northern Illinois into Michigan tonight. A ribbon of positive
vorticity advection that has supported rain/freezing rain across
portions of the Northland this morning will weaken while the
shortwave translates to the northeast. A secondary shortwave trough
that has developed out of the Four-Corners region this morning will
help push the previous shortwave to the east, while ejecting a
northern stream ribbon of PVA into the Northland later this evening
and overnight. Modest to weak isentropic lift looks to be associated
with this northern stream, so not sold on it supporting any
precipitation. Additional inhibition is provided by a push of drier
850-600 mb layer air, as evident in the latest NAM and RAP model
soundings, which removes the deeper moisture that has been in place
this morning. So, have decided not to include POPs with this
shortwave at this time. Areas of fog are also expected to develop
tonight as a low-level inversion traps boundary layer moisture,
along with light winds in place. Model guidance is hinting at
some of the thickest fog possible over the Iron Range area north
towards the International Border, and along the Gogebic Range
areas of Iron and Ashland counties. Visibilities could reduce to
as low as 2 SM in some spots, but most of the Northland should see
reductions between 3 to 5 SM.

Chances of precipitation should ramp down somewhat later this
evening, but maintaining over northwest Wisconsin overnight as
weak PVA lingers over this area. The northern PVA ribbon looks to
reinforce this lingering PVA. Moreover, deeper moisture should linger
over this area through Monday morning. So, kept chances of rain
showers for the eastern portions of our NW WI forecast area. Some
freezing rain may also develop as temperatures cool down overnight
and Monday morning. However, QPF should not be quite as high as
it was this morning, so not expecting much ice accumulation, if
any at all. Any lingering precipitation should diminish by Monday
afternoon as high pressure builds into the region.

.LONG TERM...(Monday night through Sunday)
Issued at 251 PM CDT Sun Mar 26 2017

Split flow pattern will continue for most of the upcoming week, with
the primary storm storm track remaining to our south from the
central Plains States into the middle Great Lakes, and another
series of fast-moving waves traversing Canada to our north in faster
more zonal flow aloft.

Overall, this will mean generally tranquil weather with a slow
warming trend, although there will be a few small chances for
precipitation with several weak disturbances traversing the region.
Temperatures, especially at night and during the early mornings, may
be sufficiently cold to support some wintry mixed precip, but
overall this should not amount to many significant impacts.


.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1215 AM CDT Mon Mar 27 2017

A trough of low pressure at the surface and a shortwave were moving
through portions of the Northland late this evening and they will
continue into Monday morning. Conditions varied from VFR over a good
portion of northern Minnesota to VLIFR around Lake Superior to
IFR/MVFR over northwest Wisconsin. Drizzle or freezing drizzle will
be possible over portions of northwest Wisconsin into Monday morning
as the shortwave impacts that area.

We do expect fog to continue to form overnight but confidence in how
dense it becomes and if stratus expands once again are lower than
average. KDLH has bounced around from from LIFR to MVFR and back to
LIFR. We think areas around Lake Superior will have the best chance
at seeing LIFR or VLIFR conditions. Conditions will then improve on
Monday as surface high pressure builds in. We expect most areas will
improve to VFR at some point during the day but not all with areas
around Lake Superior most likely to see lower conditions linger.


DLH  32  43  28  47 /  30  10   0   0
INL  29  46  27  48 /  10   0   0  10
BRD  33  54  30  56 /  10  10   0   0
HYR  32  45  26  52 /  30  20   0   0
ASX  31  42  26  45 /  30  10   0   0




LONG TERM...Miller
AVIATION...Melde is the U.S. government's official web portal to all federal, state and local government web resources and services.