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Area forecast discussion 
National Weather Service La Crosse WI
1111 am CDT Friday Oct 9 2015

Short term...(today and tonight)
issued at 249 am CDT Friday Oct 9 2015

Area continues to be downstream of large upper ridge over northwest
U.S. In northwest flow. Short wave trough in flow generating just
enough lift for patchy drizzle overnight with stratus field across
much of the three state area. But this wave will exit this morning
and with stratus quickly clearing in subsidence and wake of this
feature...conditions should improve as the day GOES on...with more
seasonal temperatures.

Fast evolving flow will make for quick surface ridge passage tonight
as southwest low level winds return by early Saturday. Given lighter
winds though across central Wisconsin into daybreak...could see
decoupling and some patchy frost again in favored cold/bog areas.
Impact should be fairly local so no headlines expected at this time.

Long term...(saturday through thursday)
issued at 249 am CDT Friday Oct 9 2015

While general streak of nice autumn weather will continue...higher
amplified flow will make for interesting changes and minor
challenges this weekend and into next week.

Main feature of interest will be tracking fairly strong short wave
trough across northern tier of states. Medium range guidance in
fairly good agreement with track and speed of this. As this wave
enters Continental U.S.... mean upper ridge will shift east for the weekend
with warming temperatures and breezy conditions at times.
Temperatures rebound on Saturday as heights rise...but much larger
impact will be noticed on Sunday.

As wave approaches...response will tighten gradient with gusty
southwest winds and modest warm air advection on Sunday. Should
still see plenty of sunshine given dry airmass so lots to favor near
record warmth for middle October...2 Standard deviations in temperature
anomaly data. See climate section below for specifics. While airmass
is dry...some increase in moisture and limited mixing Sunday should
limit fire weather concerns. Fire weather section below covers those
threats more.

This same wave will dive into western Great Lakes by Monday morning.
Better qg forcing favored north of area...but strength of wave in
general will bear watching. Again...dry airmass will take some
forcing to saturate so extent of rain from this system should be
limited and rain chances remain on lower side...highest northeast of
Interstate 94.

Bigger story could be winds behind this wave on Monday...especially
given timing...expected mixing...and dry conditions as it relates to
fire weather. Details for fire weather threat listed below. Could be
strong enough for wind related headlines as well.

After that...tranquil northwest flow regime looks to continue with
temperatures at or slightly above seasonal normals. Dry pattern


Aviation...(for the 18z tafs through 18z Saturday afternoon)
issued at 1111 am CDT Friday Oct 9 2015

Area caught in between two cloud masses...the departing MVFR stratus
to the south with a VFR deck across much of Minnesota. The stratus will
continue to drop south while the bulk of the cloud shield to the
west should stay there...dissipating toward Sundown. However...some
residual moisture resides across the taf sites...and some scattered fair
weather cumulus is possible...especially on the fringes of both areas of

With high pressure overhead and light winds at the start of the
evening...thoughts move to fog potential. Winds start to increase
overnight...especially just off the surface. Believe this should
inhibit most/all fog potential at the taf sites...although farther
south into northeast Iowa/southwest WI winds could support more of a
fog threat. Some sct003 possible at klse.

Winds will be more of a factor tomorrow...and again on Monday.
Pressure gradient tightens as high pressure sinks south. Mixing
isn/T deep...but BUFKIT soundings suggest gusts into the middle 20s are
likely. Stronger winds are expected on Monday...Post a cold front
Sunday night.


Fire weather...
issued at 249 am CDT Friday Oct 9 2015

Unseasonably warm temperatures are expected across the area on
Sunday with high temperatures ranging from the middle 70s across
northern Wisconsin to the lower 80s over northeast Iowa. Southwest
winds will increase into the 12 to 17 miles per hour range with gusts
approaching 25 miles per hour at times across the open areas of southeast
Minnesota and northeast Iowa. Afternoon relative humidity values are
expected to drop into the 35 to 40 percent range Sunday afternoon.

Monday looks to be of more concern. A cold front sweeps through
Sunday night into early Monday morning with strong winds and dry
conditions expected in its wake. A dry slot pushes into the region
Monday morning into Monday afternoon with deep mixing possible.
Northwest winds are expected to increase to 20 to 30 miles per hour with gusts
of 40 to 45 miles per hour possible. Cooler temperatures...highs in the
60s...should help limit how low relative humidity values go.
However...we should see relative humidity values fall into the 35 to
40 percent range but these could drop lower if deeper mixing occurs.
Looking at the worst case...we may see late morning and afternoon
relative humidity values fall to around 27 percent. Clouds over
northern and central Wisconsin could limit mixing...but locations
along and south of Interstate 90 are expected to see more sunshine
and deeper mixing. Monitor the forecast closely over the next couple
of days as details should become more clear.


issued at 249 am CDT Friday Oct 9 2015

Given warm up expected for are the normals and records
for La Crosse/lse and Rochester/rst. Rochester could be in record

For October 11th...
lse - record 86 /1928/ normal is 62
rst - record 82 /1934/ normal is 61


Arx watches/warnings/advisories...


Short term...Shea
long term....Shea
fire weather...wetenkamp

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