Rochester, Minnesota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

154
FXUS63 KARX 201045
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
545 AM CDT Sun Jul 20 2025

.KEY MESSAGES...

- Mostly dry through Monday night. Storm chances graze southern
  and western peripheral counties in northeast Iowa and
  southeast Minnesota.

- Warm midweek, heat indices from 90F to 100F or higher possible.
  Highest confidence (70-100%) in warmest temperatures on
  Wednesday.

&&

.DISCUSSION...
Issued at 231 AM CDT Sun Jul 20 2025

Mostly Dry Through Monday Night:

Ongoing ridging with locally confluent mid level heights keep higher
preciptiation chances along western peripheral counties locally in
southeast Minnesota and northeast Iowa today through Monday night.
Evident in 2" PWATs (2+ SAs NAEFS/ENS M-Climate) mostly staving off
south and west of the forecast area through Monday night. Some northern
burbling of storms resulting in low PoPs (<20%) in northeast Iowa
and southwest WIsconsin this evening into tonight. Any storms will
be departing the warm sector and accompanying instability as they
head north therefore expect a weakening trend /should/ storms poke
into the forecast area.

Anomalous Warmth Midweek:

Progression in the synoptic pattern brings the warmer and more moist
air into the forecast area through midweek. LREF certainty in the
70 degree isodrosotherm lies along and west of the Mississippi River
Valley on Tuesday, becomes widespread for Wednesday, and drapes across
the southern half of the forecast area on Thursday (locally from northeast
Iowa into southwest Wisconsin). Current LREF (19.12Z) confidence for
95F+ heat indices primarily affect southern half of the
forecast area for Wednesday. However with a slight LREF cold
bias, the NBM has 25th to 75th surface temperatures from 92F to
96F at La Crosse, causing in heat indices near 100F. Have
continued with NBM solution in collaboration with neighbours.

Confidence in Anomalous Warmth Midweek:

As previously mentioned, overall highest confidence (70-100%) in
anomalous warmth is on Wednesday. Overall timing of strongest return
flow causing discrepancies among and between LREF members for heat
impacts on Tuesday and subsequently lasting impacts into Thursday.
GEFS/GEPS show warmer solutions with 25th to 75th temperatures of
21C to 24C at 850mb and 24 to 27C at 925mb through Tuesday. Still
slightly cooler than climatological reanalysis for locally hottest
days (24-25C @850mb / 29-30C @925mb). While the cooler EPS has remained
stable over recent forecast trends, the most recent GEFS (20.00Z)
has exhibited a 1-2C cooling trend at 850mb.

Combined with more moist dewpoint temperatures near 80F, GEFS (19.12Z)
probabilities for 90F+ heat indices are 70-90% along and southwest
of the Mississippi River Valley Tuesday. Should a quicker solution
bring the warmer and more moisture in for Tuesday, may introduce
95F heat indices farther northeast into the forecast area.

Storm Chances Through Midweek:

The easterly progression of the more moisture assisted by a weak synoptic
perturbation, slightly flattening the ridge periphery, causes precipitation
chances primarily northwest of the local forecast area Tuesday through
Tuesday night. Local impacts will be tied to southeastern extent of
storms, which will hinge on strength and accompanying location of
the synoptic ridge. Storm confidence increases (70- 100% LREF) through
Wednesday/Wednesday night as a frontal boundary and synoptic trough
sag southeast through the forecast area,

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 543 AM CDT Sun Jul 20 2025

A deck of IFR/MVFR clouds over central and west-central
Wisconsin will advect west into the TAF sites. They should
arrive in KLSE around 20.12z and KRST around 20.13z. These
clouds will then persist through mid to late morning
(20.14z-20.16z). Once they mix out, both ceilings and
visibilities will be VFR through tonight.

&&

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

&&

$$

DISCUSSION...JAR
AVIATION...Boyne