587
FXUS63 KMPX 221746
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1246 PM CDT Wed May 22 2024

.KEY MESSAGES...

- Active pattern remains bringing additional chances for rain
Thursday night into Friday and Memorial Day.

- Mild temperatures expected through the holiday weekend.

&&

.DISCUSSION...
Issued at 302 AM CDT Wed May 22 2024

Light, stratiform rain associated with the deformation band on the
west side of the surface low continues over our WI counties early
this morning. This activity is slowly moving east and should clear
the MPX CWA prior to sunrise, though some mist may still occur (like
what is currently being observed at our office). Nearly the entire
CWA received at least 0.5" of rain over the last 24 hours with the
big "winner" being a corridor from the Twin Cities metro into
northwest WI. Here, amounts range from 1.5" to around 2.5". It`s
kinda nice to hear the soil squish beneath your feet again. Westerly
winds will be breezy this morning but gradually slow as Wednesday
progresses with the surface low moving away. A few afternoon showers
are possible underneath the cyclonic flow aloft, mainly north of I-
94. Otherwise, the rest of area will see a relatively nice day with
partly sunny skies and highs upper 60s to lower 70s.

Our winds will flip to southerly ahead of the next incoming
shortwave Thursday, warming us completely into the 70s during the
afternoon. We will be dry to start the day, but PoPs increase in
western MN heading into the evening hours as forecast models develop
showers and thunderstorms in the eastern Dakotas and track them
eastward. If thunderstorms can arrive in western MN early enough in
the evening so surface parcels are still able to be lifted, a small
severe risk would also exist. The primary threat appears to be
damaging winds, as the cold front would be catching the convection
and thus favoring line segments. Forecast models do develop
additional precip along the cold front as it travels east across the
CWA overnight Thursday into Friday afternoon. Categorical PoPs along
the entire cold highlight the confidence in guidance of an extended
line of precipitation with this system. So expect wet weather for at
least the first half of Friday. Once the front passes through, we
should dry out and see a brief cool down with the change of air mass
following the front. Lows Friday night look a little chilly with
temperatures currently forecast in the low to mid 40s.

Temperature-wise, the holiday weekend looks mild with temperatures
hanging near or just below normal. A welcome change from the
abnormal warmth we`ve experienced the last few Memorial Day
weekends. Guidance does give us a chance for rain later Sunday into
Monday as models favor a system developing over the Central Plains
and tracking northeast into the Lower Great Lakes. If this comes to
fruition, MN/WI would be affected by northern fringes of the precip
shield associated with the deformation band and precip shield north
of the warm front. However, considerable model spread still exists
on exact low track and how far north the precipitation extends.
Thus, only have PoPs in the 30s at this time. Afterwards, the
weather appears to become quieter as long-range ensembles favor
upper-level ridging building over the western CONUS and slowly
pushing east during the middle to latter half of next week. This
could also signal a return to warmer than normal temperatures as we
approach June.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1237 PM CDT Wed May 22 2024

VFR conditions through the period with SCT/BKN cumulus through
sunset. Isolated showers are expected to develop later this
afternoon, mainly along & north of Interstate 94, but the
probability of rain impacting any one terminal (10-20%) is too
low to include a mention in the TAF. A few instances of
lightning are also possible with any of the showers this
afternoon. Westerly winds will gust to 25-30 kts this afternoon,
with speeds diminishing towards sunset & eventually dropping
below 5 kts by 01-02Z. Winds back from southwesterly to
southerly overnight into tomorrow morning.

KMSP...Can`t rule out an isolated shower or thunderstorm late
this afternoon in the vicinity of the terminal. Any impacts
would be brief.

/OUTLOOK FOR KMSP/
FRI...VFR/MVFR with -SHRA/TSRA likely. Wind SE 10-20 kts,
becoming W 15-25 kts during the afternoon.
SAT...VFR. Wind SW 10-15 kts.
SUN...VFR. Wind E 10-15 kts.

&&

.HYDROLOGY...
Issued at 321 PM CDT Mon May 20 2024

Given the setup for widespread heavy rainfall, were certain to
see most rivers in the area end their recent recession and
begin rising once again. Extended probabilistic guidance (HEFS)
shows the potential for decent rises on area rivers should
rainfall exceed 2.5 inches or so over large areas, something
that is in the realm of possibility. The upper Minnesota and
tributaries, as well as the Crow river basin, are probably the
most susceptible to seeing rises to near or above flood stage by
later in the week should this occur. Urban/small
stream/overland flooding is also possible during and shortly
after some of the heavier downpours Tuesday and Tuesday night.

A reminder: The NWS hydrology/river forecast webpage (AHPS) at
water.weather.gov is going to be discontinued next week (May
28th). The new site (NWPS, the National Water Prediction
Service) is located at water.noaa.gov  now is the time to
replace bookmarks and familiarize yourself with how the new site
looks and feels. Resources for learning more are available at
the bottom of this page: https:/www.weather.gov/owp/operations

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.

&&

$$

DISCUSSION...CTG
AVIATION...ETA
HYDROLOGY...CCS