Rochester, Minnesota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

266
FXUS63 KARX 141752
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1252 PM CDT Wed May 14 2025

.KEY MESSAGES...

- A few showers and storms again today (20-40%), mostly in the
afternoon. A lot more miss than hit.

- Strong to severe storms possible Thu afternoon-evening. Current
risk is trending east of the Mississippi river - but timing/location
is not certain (yet). Large hail, damaging wind gusts primary
concerns.

&&

.DISCUSSION...
Issued at 240 AM CDT Wed May 14 2025

- TODAY: a few more afternoon showers/storms possible (20-40%).
Similar to what occurred Tue.

Remnants of an upper level low remain anchored across the region
early this morning, evidenced by a small curl in the latest
watervapor satellite imagery. Little/if any push in the upper
atmosphere to dislodge it - at least for today. The associated bits
of upper level energy could provide some focus for afternoon
shower/storm development with little/if any sfc boundaries to act as
a trigger. Mostly, the rain threat will be associated with reaching
convective temps (by 1 pm) and upwards of 1k J/kg of SBCAPE (in the
RAP). Then, any subtle boundaries (outflows, cloud/sunny temp
discontinuities, etc) could spark additional shower-storms here and
there.

Not much wind so any convection would be slow moving - and could
lead to a quick 1/4-1/2" for a location where 5 miles in any other
direction it stays sunny. Small hail can`t be ruled out either, but
don`t anticipate severe weather.


-THURSDAY: severe storm threat

Upper level trough set to swing northeast out of the rockies today,
becoming negatively tilted with cyclogenesis kicking in as it moves
across the plain states. The storm system`s sfc low is progged to
lift across far eastern ND/northwest MN by 00z Fri, whipping the
southeastward extending cold front northeast across the local area.
The stronger upper level dynamics linger behind the front, but a
branch may catch up to the the sfc boundary for Thu evening. Mostly
though, the deterministic runs of the NAM/GFS/EC hold the brunt of
the shortwave energy north of the local area for Thu/Thu night.

In the morning a warm front is progged to be lifting north/northeast
across the region, likely spawning showers/storms along it. Short
term guidance holds most of this activity across MN, into northwest
WI.

Fetch of relatively warm/moist air will funnel northward behind the
warm front, ahead of the cold front (albeit still overdone in the
GFS). With sfc Tds in the mid 60s, SBCAPEs of 2500+ J/kg should
manifest in the warm sector. However, that warming will also work to
cap the atmosphere - which latest RAP/HRRR soundings suggest won`t
"break" until mid/late afternoon. Essentially, with the stronger cap
(warmer air) to the southeast - convection along the front could
unzipper from northwest to southeast as sfc temps warm and
mechanical lifting along the front lift parcels into the unstable
air a loft. Convection could be rather explosive once it sparks -
and the radar could "light up" within 1/2-1 hour. A scenario the
HRRR favors.

How quickly this occurs and where is a question that doesn`t have a
clear answer. Latest HRRR/RAP blossom storms at mid afternoon (2-
4pm), expanding southeast along the front. Many (most?) of the CAMS
also currently favoring north/east of I-94 for the stronger-severe
storms...IF the system continues at its current progged pace. That
said, a lot of support for the primary severe risk to lie east of
the Mississippi River, locally focused from mid afternoon into early
evening locally. "Fatter" CAPE profile/mid level lapse rates lend
themselves to large hail production with shear also suggestive of a
damaging wind risk (35-40kts 0-3km). Tornadoes remain possible,
perhaps more in the super-cell mode rather than QLCS (locally).

Expect some revision to location/timing/expectations over the next
24-36 hours.


-NEXT WEEK: the EPS and GEFS present a busy, fast moving weather
pattern as we move into the new week. Gone is the several days/week
of ridge dominant impacts (warm-low humidity-mostly dry conditions).
Instead, this scenario paints a trough-ridge, trough-ridge picture,
with each of the features influencing the area for a couple days.
While the models suffer from some differences in timing/location
with the various weather elements (not unexpected), shower-storm
chances will be more common with temps mostly hovering near the
seasonable norms.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1248 PM CDT Wed May 14 2025

Isolated to scattered showers and storms are on the table again
today, similar to yesterday. It is challenging to pin down
exactly when and where a storm will develop, but along and east
of the Mississippi River is favored for the most development,
but everywhere may see some showers/storms. Have included
PROB30 groups at both RST/LSE given this possibility. Any
impacts from showers/storms will be brief, and development
should begin to wane after sunset.

An area of lower clouds moves northward into Thursday morning.
Models suggest MVFR ceilings are possible, around 30-40%, but
somewhat uncertain about how low the clouds may be. Southeast
winds then increase in speed Thursday.

&&

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

&&

$$

DISCUSSION...Rieck
AVIATION...Falkinham