New Brighton, Minnesota Weather Forecast Discussion

150
FXUS63 KMPX 180549
AFDMPX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1249 AM CDT Thu Sep 18 2025
.KEY MESSAGES...
- Chances for thunderstorms increase this afternoon, which will
  begin a period of unsettled weather expected to last through
  the weekend.
- Slow moving storms and high atmospheric moisture content will
  likely lead to areas of heavy rain totals each of the next few
  days.
&&
.DISCUSSION...
Issued at 223 PM CDT Wed Sep 17 2025
Water vapor imagery this afternoon shows broad troughing that
extends from interior PacNorthwest down to the 4-Corners region then
up to the Great Lakes. Featured within this troughing pattern, h700
low pressure rotates near the SD/NE border. Closer to home, a
stationary boundary currently resides from Lake Superior down across
southwestern MN. Cloudier skies exist across much of MN, thus have
decided to lower MaxT values this afternoon a couple of degrees
using a blend of NBM and HiRes guidance. The previously mentioned
surface boundary will continue to serve as the primary source of
convection for the rest of today. Latest RAP guidance indicates that
increased moisture will advect from the south throughout the course
of this afternoon and evening. Moderate mixed-layer instability
ranges between 1000 to 1500 J/kg and PWATs exceed 1.5 inches, which
should maintain the risk of scattered showers and thunderstorms. The
wind field continues to appear weak, thus storms will be slow moving
or meander on outflow boundaries. Given this slow storm motion
setup, it is possible that areas that do observe heavier periods of
rainfall could see localized ponding/flooding. As of the 12z HREF
QPF LPMM, a narrow corridor extends near Granite Falls over to the
Twin Cities that could see localized rainfall amounts between 2 to
2.5 inches.
As we transition into the latter half of this week into early next
week, high pressure building in over south-central Canada will serve
as a Rex Block to our current troughing pattern, meaning our PoPs
will continue to remain elevated through Friday into much of this
weekend. It is likely that daily PoPs will continue to increase as
we get closer to the weekend. Precip activity looks to simmer down
early next week once ridging over the central CONUS develops. As for
temperatures, values will return to the 70s with lows in the
mid 50s lower 60s.
&&
.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1249 AM CDT Thu Sep 18 2025
Showers tonight are mainly confined to western MN, although a
few are also present just south of EAU. Most of the area will
remain dry tonight, with lowering cigs across western and
central MN toward the early morning hours. IFR conditions are
possible for several hours into mid to late morning, then
lifting back to MVFR or VFR for Thursday afternoon. Scattered
showers and storms could develop in the afternoon, but the
better chance for showers is Thursday night.
KMSP...Expecting to stay dry and VFR overnight with light winds.
/OUTLOOK FOR KMSP/
FRI...MVFR. -SHRA likely, chc -TSRA. Wind SE 5-10 kts.
SAT...Chc MVFR/-TSRA. Wind S 5-10 kts.
SUN...Chc MVFR/-TSRA. Wind SW 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...Dunleavy
AVIATION...Borghoff

NWS MPX Office Area Forecast Discussion