Rochester, Minnesota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

271
FXUS63 KARX 140506
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1106 PM CST Wed Nov 13 2024

.KEY MESSAGES...

- Scattered showers continue to develop, but generally weaken
  as they move northeast. Rainfall amounts through tonight have
  decreased with most locations less than 0.10" (HREF
  probabilities for 0.10" now 0 to 50%).

- Dry conditions and warmer temperatures (10 to 15F above
  normal) with highs in the mid to upper 50s for the end of the
  week.

- Weather pattern turns more active for next week as rain
  chances (50 to 70%) return late Monday. Some potential for
  accumulating snow as the storm exits east for the middle part
  of next week, along with much colder air.

&&

.DISCUSSION...
Issued at 157 PM CST Wed Nov 13 2024

Overview:

A mid-tropospheric trough of low pressure was located over the
Plains with a north to south area of surface low pressure located in
the same area. The KARX VAD wind profiler shows the low level flow
through 3kft was generally from the southeast with veering winds
aloft; gradually working to moisten top down.  As a result of the
storm system being so far west and the dry air in place, with the
weakening of the system as it moves east, the rainfall area has
become narrower with time and slow to move east.
Temperatures were in the 40s to around 50 at 19Z.

Scattered showers continue to develop, but generally weaken as they
move northeast.  Rainfall amounts through tonight have decreased
with most locations less than 0.10" (HREF probabilities for 0.10"
now 0 to 50%):

Moisture transport vectors weaken over our local area and increase
over the Tennessee River Valley toward Illinois.  As a result, the
CAMs weaken the rain band through 03Z over Minnesota with the new
area of rain developing over parts of eastern Iowa, Illinois, and
southern Wisconsin.  The bulk of the rainfall is forecast to be less
than 0.10".  HREF probabilities for 0.25" or more quite low; 0 to
10%. Rainfall continues to push east tonight for most of our local
area by 12Z. The closed low over parts of the Missouri River Valley
is progged to slowly track toward the Mid-Mississippi River Valley
through Thursday morning. Ridging builds in quickly builds in for
Thursday. Above normal highs are forecast for Thursday in the 40s to
lower 50s with a mix of clouds and sunshine.

Thursday - Sunday: Above Normal Temperatures, Rain Chances?

Shortwave ridging enters the area helping to keep conditions mostly
dry through the weekend. High temperatures will be 10 to 15 degrees
above normal, which equates to highs in the mid to upper 50s.
Heading into Saturday night into Sunday morning, a shortwave trough
moves north of the region. This will bring a low chance (20 to 40%)
of rain, primarily in Wisconsin. The caveat to this rain chance is
that the GEFS members are mostly dry while the EPS has about half
its members showing precipitation occurring. Compared to the
previous forecast there is a trend of fewer EPS members showing
precipitation. If this precipitation occurs, only a couple hundreths
of rain would fall.

Monday - Wednesday: Rain, Potential for Snow?

Deterministic and ensemble guidance continues to show a shortwave
trough moving out of the desert southwest and impacting the Upper
Midwest. This trough is then forecasted to merge with the apparent
longwave trough. At the moment both deterministic runs of the GFS
and ECMWF show this merger happening over the Upper Midwest early
next week. This would prolong the effects of the storm system.
Differences in exact path of the low coming out of the southwest and
strength of it continue to exist. Regardless, the majority of
ensemble members, about 90% of EPS and GEFS members show
precipitation occurring. Ensemble clusters show a good percentage,
about 85% of all ensemble members, of this trough influencing the
area through the middle of next week. As this system moves through,
rain will be precipitation type, however as the storm exits, cold
air will wrap around and snow will be possible! Current ensemble
guidance shows around a 40 to 60% chance of measurable snow on
Wednesday. Given the complex synoptic setup, there are plenty of
things that need to be worked out, so continue to monitor as we get
closer to next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1106 PM CST Wed Nov 13 2024

MVFR/IFR cigs will persist through the overnight and into the
daytime hours across portions of southeast MN and northeast IA as
showers continue to exit the region. Low-level saturation
responsible for this may have some lift present to produce drizzle
however, this would be isolated in nature and not pose any vsby
reductions. Otherwise, will need to watch KLSE overnight as
guidance continue to suggest a narrow dry slot that tries to
keep any category reductions from reaching KLSE. Have leaned on
the side of guidance for now but will amend if needed.
Additionally, LIFR conditions remain possible (20-40%) overnight
and into the early morning at KRST however, given that the
lower confidence have opted to leave it out of the TAF at this
time. Cigs will improve marginally during the daytime hours with
some weak mixing to MVFR across southeast MN and northeast IA.
Winds will increase to around 5-10 kts and remain from the
northwest throughout the TAF period.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.

&&

$$

DISCUSSION...Cecava/Zapotocny
AVIATION...Naylor