238
FXUS63 KMPX 040905
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
405 AM CDT Sat May 4 2024

.KEY MESSAGES...

- Rain showers this morning. Rainfall amounts of a tenth to a
  quarter of an inch expected.

- Another round of showers and thunderstorms likely Monday
  night into Tuesday morning.

&&

.DISCUSSION...
Issued at 334 AM CDT Sat May 4 2024

Rain showers continue to slowly spread eastwards out of western
Minnesota overnight. The MCS over Nebraska has taken on a more
easterly track into Iowa, meaning the trend towards heavier
precipitation & possible thunderstorms over southern Minnesota
no longer is expected. Most locations will see between a tenth
to a quarter inch of rain as the band of showers north of the
convective complex migrates east across the area. A few hours of
rain is expected, with the rain ending by mid-morning across
central MN, late morning/early afternoon for eastern Minnesota,
& by mid-afternoon for western Wisconsin. Skies will slowly
clear out after the rain, so a sunny afternoon or early evening
still looks salvageable for areas east of the St. Croix River.
The rain and clouds will keep temperatures cool this afternoon,
generally around 60 degrees.

Drier, sunny, & warm weather is expected Sunday into Monday as
high pressure moves over the region. High temperatures around low
70 are likely, potentially warming into the mid to upper 70s
Monday with some compressional warming possible ahead of an
approaching front. Winds will be relatively light on Sunday with
the high overhead, but increase through the day on Monday as the
pressure gradient increases ahead of the approaching front.
Southeasterly winds could gust as high as 40-50 mph late Monday
afternoon & evening across western Minnesota, in response to the
surface low deepening into the low 980s mb over the northern
Plains.

A band of showers an thunderstorms is expected to develop along
the front extending ahead of this deepening surface low, with
ensemble guidance showing a very high likelihood (>90%) of
precipitation occurring across the entire area. Strong dynamics
will be present with this system with surface winds gusting to
40-50 mph along of the front & bulk shear values of 50-60 kts.
However, instability will be lacking this far north across the
Dakotas & western Minnesota, further exacerbated by the fact
that the model consensus brings the front & thunderstorms
through the area late Monday night & overnight into Tuesday
morning. The threat for damaging winds isn`t negligible given
the strong background surface winds, but for now the severe
threat looks to mainly develop across the central Plains & mid-
Mississippi valley. Ensemble guidance generally shows rainfall
amounts between 0.5-1" across the entire area, mainly owing to
the forecast quick progression of the storms across the area.
Amounts over an inch are still possible if the system slows
somewhat between now & Monday night. In general, thunderstorms &
another soaking rain look a like a sure bet Monday night.

Beyond Tuesday, the upper-air pattern remains active as the
upper-level low responsible for the Monday-Tuesday system stalls
out, & potential becomes cutoff over the Great Lakes. A number
of weak disturbances pivot around this broad area of low
pressure as a result, meaning multiple chances for generally
light rain through the end of the week. Model consensus in
timing any of these disturbances is low so a generic broad ~30%
chance for rain exists pretty much exists for Wed-Fri.
Temperatures will be cooler as well with lower heights over the
region, with daytime highs generally in the low 60s. The upper-
level low finally exits the Great Lakes region over the weekend,
with likely a return to drier & more seasonable weather.


&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1254 AM CDT Sat May 4 2024

Rain showers will spread across the area this morning, impacting
western MN overnight through sunrise, central & eastern MN
through early to mid-morning, & western WI mid-morning into
early afternoon. Predominately low-end MVFR visibility &
ceilings are expected with the rain, although periods of IFR
conditions are possible. MVFR ceilings will linger for a few
hours after the rain ends, with ceilings eventually rising &
clearing out through the afternoon. Winds will generally be
northerly to northwesterly between 5-10 kts, with some gusts up
to 20kts during the morning through mid-afternoon. WInds drop
below 5 kts after sunset with clear skies overnight.

KMSP...Rain is expected to start between 6-7 AM with visibility
down to 3 miles & ceilings around 1000 ft expected. Brief IFR
conditions are possible during the heaviest rain, more likely
as lower ceilings as opposed to visibility. The rain will end
around noon with MVFR ceilings lingering into mid-afternoon.

/OUTLOOK FOR KMSP/
SUN...VFR. Wind variable 5 kts becoming SE 5-10 kts.
MON...VFR. Chance PM MVFR/-RA. Wind SE 15-20G25-30 kts.
TUE...Mainly VFR. Chance MVFR/-TSRA. Wind S 15-20G25-30kts.

&&

.HYDROLOGY...
Issued at 236 PM CDT Thu May 2 2024

The continued wet pattern for the next week will also continue to
cause rising rivers over the entire HSA. Soils have started to
become saturated at upper levels, so runoff is increasing with each
rain event, though the onset of the growing season does help along
with recovery days between rain events. All told, most tributaries
and mainstem rivers will continue a slow rise for at least the next
week, with some in the Minnesota and Crow river basins approaching
minor flood stage by early next week (Minnesota at Morton already
there).

&&

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

&&

$$

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