Rochester, Minnesota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

101
FXUS63 KARX 180503
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1103 PM CST Fri Jan 17 2025

.KEY MESSAGES...

- Warmer than normal temperatures this afternoon with highs in
  the 30s to 40s.

- A cold front pushes through the area with gusty winds of 30-40
  mph and scattered flurries/snow showers late this afternoon
  through the overnight.

- Arctic air moves into the region this weekend with very high
  probabilities (60-90%) for wind chills of -25F or colder on
  Sunday through Tuesday morning across the local area.

&&

.DISCUSSION...
Issued at 215 PM CST Fri Jan 17 2025

Rest of Today - Tonight: Ongoing Warmth, Increasing Winds with
Flurries and Snow Showers

Surface observations this morning show very pleasant temperatures
this afternoon for this time of year with temperatures ranging from
the middle 30s in north-central Wisconsin to as high as 47 degrees
at Platteville in southwestern WI. So be sure to get out and enjoy it
because it unfortunately will not last for much longer. As we head
over the next few hours, a cold frontal boundary will push towards
the region with some low-level frontogenesis and steepening low-
level lapse rates as shown in the recent RAP. Initially, a fairly
dry sub-cloud layer may cause some issues getting precipitation
initially. However, as deeper saturation occurs post-frontally some
weak instability, thinking that scattered flurries/snow showers will
progress through the area into the evening and overnight. However,
minimal accumulations are anticipated with any passing snow showers.
As low-level forcing lessens and we lose the relatively steeper low-
level lapse rates, flurries/snow showers will diminish in coverage
during the early morning hours on Sunday.

Saturday - Tuesday: Arctic Air Moves Into The Region

As we progress through tonight and into Saturday, the arctic
frontal passage will continue to usher in strong cold air
advection into the region with northwesterly flow for the
weekend. Consequently, expecting temperatures to fall throughout
the day on Saturday with afternoon temperatures only in the
teens and single digits for much of the area. Continuing into
the overnight, temperatures will continue to fall with lows
crashing below zero with high confidence (60-100% in the
GEFS/EC/Canadian ensemble) for wind chills of -25F to -35F
across much of the local area. As a result, have issued a Cold
Weather Advisory beginning at 9pm on Saturday and continuing
through noon on Sunday. The main forecast question still in play
for Sunday will be if we are able to see any recovery in
temperatures and reduction in winds to enable wind chills to
increase above -25F for most of the area or if the advisory will
be needed for the entire day. Otherwise, looking towards Monday
and Tuesday, the core of the colder air moves overhead with
850mb temperatures falling to -30C across the area. As a
result, morning low temperatures will likely fall into the
negative double digits for much of the area with Tuesday morning
likely being the coldest period where typical cold spots across
north-central and central Wisconsin having fairly high
probabilities (30-70%) for seeing air temperatures below -20F in
the grand ensemble (GEFS/EC/Canadian ensemble).

Wednesday - Friday: Temperatures Return To Normal

As we head into Wednesday, the upper-level trough eventually swings
east of the region through the Great Lakes, subjecting our area
to some upper-level ridging and quickly moderating our
temperatures. Consensus across 850mb temperature fields in both
the 17.02z GFS/EC warming into the -15C to -10C range.
Consequently, median temperatures in the grand ensemble
(GEFS/EC/Canadian ensemble) quickly recover to near normal with
highs generally in the 20s across much of the local area for
Wednesday and beyond. Deterministic guidance tries to sneak in
an upper-level wave into the local area Wednesday night and into
Thursday with some precipitation potential. However, with
fairly wide variation confidence remains low in if any
precipitation will manifest so have kept with the NBM
precipitation chances for now.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1056 PM CST Fri Jan 17 2025

The cold front has pushed through the area with gusty northwest
winds and scattered flurries in its wake. Ceilings are variable
VFR/MVFR with some breaks in the clouds over parts of Minnesota.
The HREF shows decreasing low level RH, thus held on to some
scattered flurries for a few hours overnight, then improved
conditions to VFR. Mid clouds advance over the Saturday. The
HREF increases low level rh again sometime later
afternoon/evening, with reinforcing cold air, thus could see
some MVFR ceilings return. Northwest winds mostly 14 to 22kts
with gusts 22 to 30kts continue into Saturday evening.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Cold Weather Advisory from 9 PM Saturday to noon CST Sunday
     for WIZ017-029-032>034-041>044-053>055-061.
MN...Cold Weather Advisory from 9 PM Saturday to noon CST Sunday
     for MNZ079-086>088-094>096.
IA...Cold Weather Advisory from 9 PM Saturday to noon CST Sunday
     for IAZ008>011-018-019-029-030.

&&

$$

DISCUSSION...Naylor
AVIATION...Zapotocny