NWS Forecast Discussion

Below is the latest Area Forecast Discussion from the Twin Cities National Weather Service office in Chanhassen, MN. It gives insight into why the forecasters are making the predictions you read in your local forecast. The overall "big picture" of the atmospheric setup is well described, as well as the forecasters' interpretation of the various Computer Atmospheric Models (CAMs). Sometimes, very specific information is available here that is not available, or otherwise generalized, in the public forecast.

727
FXUS63 KMPX 170826
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
326 AM CDT Fri May 17 2024

.KEY MESSAGES...
- Low RH values Saturday afternoon could result in areas of
  elevated fire weather conditions.

- Increasing confidence for showers and thunderstorms Sunday
  night into Monday morning. The risk for severe weather is
  low.

- An active pattern set to begin Sunday night. Multiple chances
  for rain, possibly heavy, and thunderstorms over the next
  seven days.

&&

.DISCUSSION...
Issued at 322 AM CDT Fri May 17 2024

TODAY THROUGH SUNDAY... Scattered thunderstorms across west &
central Minnesota north of I-94 this morning that`ll taper off
as the storms move further east into a more stable and drier
environment. Warm air advection will kick in today as an
impressive low level jet roaring aloft. Temperatures climb into
the low to mid 80s across MN & WI, with a solid shot at 90
across western Minnesota. There is a non-zero chance for
isolated thunderstorms this afternoon, but there is a lot
working against it. Forecast soundings highlight an impressive
inverted V featuring very dry low levels that`ll limit any
chance for precip to make it to the surface (virga). Saturday
will feature another pleasantly warm day, but we`ll have to keep
an eye on elevated fire weather potential Saturday afternoon
post-fropa as RH values could drop into the 20-25 percent range.


A sfc cold front will pass through the Upper Midwest. This will
present western Wisconsin with a slight chance for thunderstorms to
develop along it Saturday afternoon. Rusk Co is included in SPC`s
day 2 outlook, but most CAMs don`t initiate until past the MPX WI
CWA. Sunday will see an uptick in PoPs throughout the day as
southeast flow will ramp up moisture advection into the region. The
quasi-stationary front across Iowa will become a focal point for a
rather active pattern setting up over the next week or so.

SUNDAY NIGHT THROUGH THURSDAY NIGHT... A mid-level trough amplifying
over the western CONUS will drive southwest flow aloft over the
region throughout the week. WPC has highlighted days 3-5 with
marginal chances for excessive rainfall. The first shortwave moves
through Sunday night and will bring widespread rain and
thunderstorms across Minnesota and western Wisconsin. It looks like
the best chance for widespread and heavy rain will be across S MN
and into W WI. Monday will dry out, but by Monday night another
round of storms and showers will ride along the stationary boundary
set up across the Upper Mississippi Valley. This batch of possible
heavy rainfall will be in the late Monday into Tuesday time frame
when guidance indicates a more potent shortwave energy lifting
across the stationary frontal boundary draped across the region.
Model uncertainty spikes later into the week but it certainly looks
possible that additional round of showers Wednesday evening into
Thursday morning.

Showers could linger into Thursday before drying out on Friday.
Temperatures start off in the extended with highs in the upper
70s Sunday and Monday. However, temperatures will trend cooler
in the wake of the Tuesday low pressure system/frontal boundary
pushing off to our south and east. This pattern also would
suggest a cloudier forecast that would support cooler
temperatures. This active pattern looks to continue into
Memorial Day weekend before things "dry out" toward the end of
May.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1222 AM CDT Fri May 17 2024

VFR conditions expected throughout this TAF duration. A FEW to
SCT mid-level deck is possible this afternoon, but VFR
nonetheless. There is also a slight chance of a few showers
over western and central MN around sunrise, but chances are too
low for inclusion. Breezy westerly winds at initialization will
diminish to around 5 kts late this evening through the overnight
hours and back to southerly, then increase to near 10 kts by
late this morning. Added gusts after 18z to capture a bump in
hi-res models.

KMSP...No additional concerns.

/OUTLOOK FOR KMSP/
SAT...VFR, slight chc MVFR/-TSRA. Wind S to W 15-20G30kts.
SUN...VFR, chc MVFR/SHRA late. Wind SE 10-15kts.
MON...MVFR/-TSRA. Wind SE 5-10 kts, bcmg NW 5-15 kts.

&&

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

&&

$$

DISCUSSION...BPH
AVIATION...BPH

NWS MPX Office Area Forecast Discussion