145
FXUS63 KMPX 210802
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
302 AM CDT Wed May 21 2025

.KEY MESSAGES...

- Widespread rain showers continue today, diminishing gradually
  throughout the day

- Temperatures slowly warm but remain below normal through
  Memorial Day weekend. Isolated showers are possible Saturday
  and Sunday with no significant accumulation expected.

&&

.DISCUSSION...
Issued at 301 AM CDT Wed May 21 2025

The radar has slowly filled back in this morning as echoes had
backed off during the evening as our upper level low continues to
churn over the region, centered over western Minnesota with the
surface low over southern Lake Michigan per the latest surface
analysis. Differential water vapor RGB on GOES-East shows a bit of
dry air entering the circulation from the south, with the greatest
moisture contained within the eastern edge of the upper level low
over Western WI and eastern MN where the showers have returned.
Widespread showers are expected to continue for most of today
diminishing gradually into the afternoon and evening as the upper
level occlusion weakens as the front edge of a southern stream ridge
forces a positive tilt, alongside the surface low migrating towards
Lake Erie by 06z Thursday. The last of the light showers will be
over shortly afterwards, with dry conditions beginning Thursday and
lasting through at least Saturday as skies also clear up allowing
for the sun to return. By 12z Friday upper level flow will have
turned northwesterly as the apex of the western ridge is over the
Dakotas, with wide scale subsidence allowing for clear skies and
cool temperatures which looks to linger through the weekend.

A few ensemble members want to bring some isolated showers to the
area on Saturday and Sunday primarily due to a mid level shortwave
and weak surface low as the upper level ridge sags southwards into
the central plains. The deterministic GFS is the main outlier in
bringing wetter conditions to primarily the southern half of
Minnesota on Sunday as it produces a robust shortwave across the
area, while the other deterministic global guidance remains muted
and dry as surface high pressure keeps showers from forming. The
overall ensemble picture produces more of a dry than a wet signal,
which was reflected in the NBM as POPs were kept in the slight
chance to chance categories. Given the weak subsidence signal and
westerly to northwesterly flow aloft, we should strike a balance
between warming but also remaining below normal, with highs for the
day ultimately dependent on how much cloud cover or showery weather
forms. The pattern into the middle of the week continues to favor
northerly flow aloft and weak surface high pressure over the region,
contributing to an overall drier signal aside from potential weak
showers due to shorter range or smaller scale features.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1216 AM CDT Wed May 21 2025

IFR/LIFR conditions expected area-wide through at least
Wednesday morning as cigs under 1000 feet, mist, and rain
showers persist. Current radar shows rain showers filling in
again across eastern MN and WI. This trend should continue
through Wednesday morning with a gradual expansion of rain
westward late morning into the afternoon along a northwest to
southeast stationary front. Rain should then dissipate from
north to south during Wednesday evening. Expect visibilities to
hang somewhere between 3-5sm from mist and showers. Also, not
optimistic about cigs and cloud cover improving quickly. Kept
most terminals south of AXN, STC, and RNH only improving to MVFR
by the end of the TAF period. East-northeasterly winds of 7-10
knots expected at most terminals through Wednesday afternoon
before shifting northerly and slowing. However, RWF and MKT will
be south of the stationary front and their winds will be
northwesterly during Wednesday.

KMSP...Showers and IFR cigs look likely until Wednesday evening
before cigs begin to lift and rain tapers off. Thinking
improvement to MVFR occurs around 03Z Thursday and then VFR by
06Z as clouds lift and break apart. East-northeasterly winds of
7-10 knots expected into Wednesday afternoon before winds
gradually turn northerly and slow to near 5 knots.

/OUTLOOK FOR KMSP/
THU...VFR. Wind N 10-15kts.
FRI...VFR. Wind NE 5-10kts.
SAT...VFR. Wind E 5-10kts.

&&

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

&&

$$

DISCUSSION...TDH
AVIATION...CTG