233
FXUS63 KMPX 061729
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1229 PM CDT Sat Jul 6 2024

.KEY MESSAGES...

- Scattered showers and storms this afternoon and evening,
  diminishing after sunset. Locally heavy rain could result in
  up to a half inch of accumulation, most of the area within a
  quarter inch.

- Further chances for daytime heating driven showers and storms
  for the next few days. Temperatures gradually warm throughout
  the week.

&&

.DISCUSSION...
Issued at 309 AM CDT Sat Jul 6 2024

Compared to yesterday morning at this time, we are dealing with a
lower both spread and depth of fog with the main tricky spots still
persisting over western Wisconsin, which makes sense given the
longer residence time of showers over that area today. Visibility
has dropped below 3 miles in spots but should improve quickly after
sunrise with free mixing expected today. Satellite imagery shows
some deeper clouds with weak convection in central South Dakota,
however the states of Minnesota and Wisconsin are generally clear
with only a few smaller banks of stratus aside from the fog. An
extremely broad trough is currently stretching over the CONUS with
the only forcing to speak of being an upper level jet in eastern
Canada with weak high pressure holding over the center of the
country. This makes for a perfect setup for mostly clear skies and
sunshine to begin the day, which will allow for efficient mixing and
eventually the potential for showers and thunderstorms by the
afternoon through the evening. Deterministic CAMs and also HREF
output show a broad area of showers and storms favoring western
Minnesota this afternoon with instability building to upwards of
1000 J/KG SBCAPE. There is a lack of deep layer shear and much of
the activity will end up being pulse-like or multicellular such that
the potential for severe storms is low but non-zero. We`ve slightly
bumped up both PoP and QPF for the afternoon as guidance is
consistent in producing showers and storms, with activity quickly
cutting off after sunset with the mixing resulting in a loss of
forcing as it diminishes.

This setup is more or less what we have to work with over the next
few days, with chances for mainly afternoon to early evening showers
and storms through at least Tuesday afternoon. Compared to today,
the chances seem marginally weaker as we head into early next week
with an upper level trough taking on a positive tilt and further
solidifying a lack of synoptic scale reinforcement of what looks to
be diurnally driven activity. Temperatures will likewise reflect our
sunshine and lack of movement, with highs in the upper 70s to low
80s across the area through the majority of the forecast period,
creeping up towards the mid 80s by the end of the week. The primary
thing to watch out for will be the atmospheric response to Beryl as
it makes landfall and begins to modify the surrounding environment,
as at least for now the track does not bring it far enough north to
affect us aside from keeping weak high pressure locked in place.
Overall, a fairly quiet period with some typically summertime
activity, a far cry from the setup which gave us the persistent
rainfall over the last few weeks.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1211 PM CDT Sat Jul 6 2024

Pop-up thunderstorms have begun to develop across western to
central MN early this afternoon. This activity should be short-
lived but could pass by RWF, AXN, and STC. The more likely
timing for more widespread thunderstorms will be late this
afternoon in western MN as a mid-level disturbance arrives from
the west. These scattered storms will travel west to east across
MN this evening, likely weakening to just rain around 06Z, and
reaching WI early Sunday morning. Have included TEMPOs at MN
terminals for possibility of MVFR during thunderstorms. Outside
of the storms, VFR is likely with cigs dropping to low end VFR
at RNH and EAU towards the end of the period. However, patchy
fog does look possible at AXN near sunrise Sunday. South-
southwesterly winds will slow overnight (with a more southerly
component) before returning again Sunday morning.

KMSP...Kept PROB30 for isolated -TSRA from 22-02Z today. Rain
showers look possible from midnight to sunrise as a disturbance
passes through but conditions should remain VFR. Chance of
afternoon -TSRA again Sunday.

/OUTLOOK FOR KMSP/
MON...VFR. Chc aftn SHRA/TSRA. Wind W 5-10 kts.
TUE...VFR. Chc aftn SHRA/TSRA. Wind NW 5-10 kts.
WED...VFR. Chc aftn SHRA/TSRA. Wind NE 5-10 kts.

&&

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

&&

$$

DISCUSSION...TDH
AVIATION...CTG