NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 131130
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
630 AM CDT Sun Jul 13 2025

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Near-surface Canadian wildfire smoke will continue to result in
  poor air quality and reduced visibilities through Monday
  morning. An Air Quality Advisory remains in effect.

- Next round of more widespread active weather arrives Tuesday
  afternoon into Wednesday.

&&

.DISCUSSION...
Issued at 257 AM CDT Sun Jul 13 2025

Rain chances... Some CAMs hint at a weak surface boundary passing
over northern Wisconsin this afternoon, which could produce an
isolated shower. This being said, just as many CAMs keep us dry
throughout the day, though have opted to retain slight chance
PoPs in the forecast. Similarly, a wrung-out frontal boundary and
shallow mid-level shortwave may be enough to squeeze out a shower
or two on Monday, although any resultant rainfall would be trivial
compared to what we've seen over the past week. Next chances for
more widespread precip then look to arrive sometime on Wednesday,
accompanying a quasi-stationary front that sets up over central
Wisconsin. Instability and moisture build along/south of the
boundary during the afternoon as several transient shortwaves ride
along predominantly zonal flow, although heavier rain or thunder
potential would likely hinge on any north/south wobbles of the
front. Will continue to monitor in the coming days.

Smoke trends... Overnight obs show visibilities gradually rising
in response to a lull in near-surface smoke activity. This brief
reprieve will not be long-lived, however, as RAP/HRRR smoke
guidance shows another bout of elevated smoke arriving later this
morning. Some of this smoke may make it down to the surface
provided some mixing occurs, with highest concentrations across
northern Wisconsin. Westerly winds will then usher in yet another
plume from out over Minnesota Monday morning. An Air Quality
Advisory remains in effect until noon on Monday.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 626 AM CDT Sun Jul 13 2025

Near-surface Canadian wildfire smoke is still on track to impact
northeast Wisconsin today, degrading air quality and reducing vsbys
from west to east beginning this morning. Thickest smoke will set
up over north-central Wisconsin, where vsbys may drop to IFR at
times. Opted to include 2 SM in the RHI TAF due to morning
trends, though included 4 to 6 SM elsewhere. Attempted to provide
resolution/timing where possible of conditions improving later in
the evening. Otherwise, only cloud cover will come in the form of
SCT daytime cu field.

LLWS may briefly make it down to RHI early Monday morning as 40
knot 850 mb jet noses into north-central Wisconsin, though decided
not to include in the TAF due to its short-lived/uncertain nature.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION.....Goodin
AVIATION.......Goodin