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fxus63 kdlh 202333 

Area forecast discussion
National Weather Service Duluth Minnesota
633 PM CDT Tue Mar 20 2018

issued at 631 PM CDT Tue Mar 20 2018

Updating aviation section below for the 00z taf update.


Short term...(this evening through wednesday)
issued at 230 PM CDT Tue Mar 20 2018

Weak short wave trough currently moving through the region will
shift to the south and east tonight, bringing any light snow to an
end across the southern portion of the area. We may see some
patchy fog tonight into Wednesday morning, particularly over the
western and southern portions of the forecast area. Benign weather
is expected Wednesday as we remain under fairly dry northwest

Long term...(wednesday night through tuesday)
issued at 230 PM CDT Tue Mar 20 2018

Predominantly northwest upper flow looks to persist for most of
the period, with the main weather item(s) of interest over the
weekend into the start of next week as the pattern looks to
transition with heights building across the region. We look to
remain on the southern/western ridge of surface high pressure
centered over Canada through Thursday night. After that we will
start to get into return flow, and see some warm advection and
deeper moisture begin to work into the region, with precipitation
eventually developing from west to east late Friday into Saturday.
The deterministic guidance (gfs, ECMWF, canadian) start to deviate
quite a bit in forecast details after Friday, and there is
significant spread in their respective ensembles after that point,
leading to fairly low forecast confidence in the forecast details
after Friday. However, we look to have a decent shot at some light
snow with higher pops from late Friday night into Saturday
morning across the western and southern portion of the area, with
the north and northeast looking like they could stay mostly dry
during that time. The main baroclinic zone and surface low remain
well to our south, so any significant precipitation looks to stay
south of US. The next feature of interest will try to work into
the area late Sunday into Monday, although there is substantial
disagreement in the speed, amplitude, and degree of phasing
between northern and southern stream waves, leading to an
extending period of pops from late Sunday into Tuesday given the
uncertainty and need to stick with a consensus forecast at this
point. Later forecasts should be able to shorten up the overall
time period precipitation potential and get a better handle on
precipitation type. At this point, mainly tied precipitation type
to expected boundary layer temperatures, leading to a mention of
rain and snow over that time period.


Aviation...(for the 00z tafs through 00z Wednesday evening)
issued at 631 PM CDT Tue Mar 20 2018

Overall, getting quieter as a system moves out of the region. VFR
for most sites, but isolated to scattered MVFR possible -
especially south and west of kdlh. A little light wintry precip
may linger under thicker clouds; otherwise, improving conditions
for Wednesday.


Preliminary point temps/pops...
dlh 19 33 16 39 / 10 0 0 0
inl 15 38 17 42 / 10 0 10 10
brd 22 38 22 41 / 20 0 0 0
hyr 13 38 13 41 / 10 0 0 0
asx 15 33 15 39 / 10 0 10 10


Dlh watches/warnings/advisories...


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