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Area forecast discussion
National Weather Service La Crosse WI
638 PM CDT Mon Sep 16 2019

Short term...(tonight through Tuesday night)
issued at 145 PM CDT Mon Sep 16 2019

Sure this is mid-september? The weather on tap over the next few
days will feel more August-like as southwest flow aloft allows very
warm and humid airmass to overspread the region. Temperatures this
afternoon as of 2 PM were in the 80s most places with dew points in
the mid 60s.

A mid-level trough rotates toward the upper Mississippi Valley
region overnight through Tuesday. This will spread some mid
cloud/altocumulus into the area. Otherwise, bulk of 850mb moisture
transport steers west of the area over Minnesota into far northwest WI -or
northwest of our forecast area. This is where the deterministic and
cams keep qpf/showers and storms. Otherwise, another warm one for
Tuesday with highs topping off again well into the 80s for much of
the area.

Shower and storm chances move into portions of Minnesota/IA/western WI
later Tuesday night as a cold front pushes from the Dakotas into Minnesota.
Better shear and instability stay west of the area with BUFKIT
sounding showing mainly elevated convection over our area. Not
really looking at anything severe with this then but storms could
produce some locally heavier rainfall as precipitable water values
creep up into the 1.25 to 1.5 inch range.

Long term...(wednesday through monday)
issued at 145 PM CDT Mon Sep 16 2019

Cold front sinks ever so slowly southeast into the area Wednesday
into Thursday with increasing precipitable water values and cape.
However, bulk shear remains fairly weak -generally 15-20kt, so not
expecting any widespread severe. That being said, rainfall could be
quite heavy at times with precipitable water values in the 1.5 to
2.25" range. Will have to keep an eye out for some localized
flooding, especially those areas across southwest WI that got heavy
rain this last week. Remaining on the warm and muggy side otherwise
with highs in the upper 70s to middle 80s and dew points in the
60s/lower 70s.

Area of low pressure rolls out of The Rockies into the northern
plains Friday, pushing another/stronger cold front toward the
region. Increasing moisture transport ahead of the front will
produce more shower and thunderstorm chances. Cold front pushes into
our area Saturday with increasing bulk shear values. May have to
watch for a few stronger storms then along with that continued
threat for some localized heavier rainfall in the warm/muggy
airmass.

Models show mid-level trough lingering across the area Sunday for
plenty of cumulus and perhaps a few showers.

Ridging builds in for Monday for what looks to be a drier/pleasant
day.

&&

Aviation...(for the 00z tafs through 00z Tuesday evening)
issued at 623 PM CDT Mon Sep 16 2019

A short wave trough moving northeast of Nebraska will continue to
produce broken mid and high clouds across the area through
tonight. The combination of these clouds and a slightly stronger
wind gradient than last night will limit the fog development
tonight. The highest probabilities will be found in Wisconsin and
Kickapoo river valleys of southwest Wisconsin. There will likely
be some fog in the Mississippi channel. The main question is
whether it will impact klse or not. For now, just kept a scattered
to broken IFR deck and mentioned the potential of bcfg.

&&

Arx watches/warnings/advisories...
WI...none.
Minnesota...none.
Iowa...none.
&&

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