938
FXUS63 KGRB 131942
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
242 PM CDT Mon May 13 2024

Forecast discussion for routine afternoon forecast issuance

.KEY MESSAGES...

- An area of smoke or haze are expected to clear out of the
  region from northeast to southwest this evening. The smoke or
  haze may result in poor air quality at times until it clears
  out.

- Areas of frost are possible over the sandy soil ares of north-
  central and far northeast Wisconsin tonight and Tuesday night.

- After a dry period on Tuesday and Wednesday, the chance of rain
  and possibly some storms will return at times from Thursday
  through next Monday.

&&

.DISCUSSION...
Issued at 241 PM CDT Mon May 13 2024

Short Term...Tonight and Tuesday

An area of showers is slowly pushing northeast through southeast WI
along a nearly stationary surface boundary. Locations south of an
Oshkosh to Manitowoc line may see a few light showers this afternoon
and evening. A few rumbles of thunder may be hear, but the best
chance any thunderstorms will remain well south near Milwaukee.

Smoke and haze from Canadian wildfires will continue to linger over
much of the region through this afternoon. Winds shifting around to
the northeast and increasing slightly this evening and overnight
should disperse the smoke from northeast to southwest. As the smoke
disperses skies should become mostly clear through Tuesday.

Patchy areas of frost will be possible tonight across far northern
WI, mainly in low laying areas and sandy soil areas. Gradient
winds gusting 10-15 mph should be strong enough to prevent frost
from becoming widespread, so did not issue a Frost Advisory for
tonight.

High pressure settling over Lake Superior Tuesday will bring quiet
conditions to the region. Mixing to around 2000ft Tuesday afternoon
may bring some drier air to the surface with RHs dropping to 25-30
percent across northern WI during the afternoon. Fire weather
concerns are tempered with light NE winds only gusting 10-15 mph
across northern WI. Temperatures Tuesday will a few degrees cooler
than today, with highs in the 60s across the region, expect along
the lakeshore were onshore flow will keep highs in the mid to upper
50s.

Long Term...Tuesday Night Through Monday

Generally quiet spring weather is expected through midweek, with
unsettled weather expected from Wednesday night through early next
week. Beyond Thursday, forecast confidence in the details drops
significantly due to large spread amongst and within various
ensemble systems.

High pressure will keep the weather dry and quiet through
Wednesday. Clear skies and light winds could bring some frost
across north-central Wisconsin Tuesday night. the highest
probabilities will be across the sandy soil regions of north-
central Wisconsin.

An approaching low pressure system will bring the chance for rain
from west to east Wednesday night into Thursday. The rain will
bring relief from the low RH values and help to alleviate fire
weather concerns; however, rainfall amounts are expected to be
light with only 0.1 to 0.2 inches of QPF expected.

Beyond Thursday, a PV anomaly of varying strengths will track
through the northern Great Lakes late in the week. The strength of
this system will be the difference between a dry Friday (weaker)
or a wet Friday (stronger). Given the model differences,
confidence in the forecast at the end of the week is fairly low.

The forecast for the weekend doesn`t get any clearer as the flow
flattens out and several weak shortwaves bring the chance for rain
at times. Overall it appears the weekend will have more dry
periods than wet periods with the potential for unsettled weather
anywhere from Sunday to Monday depending on the strength and
timing of a stronger low pressure system and attendant mid level
trough expected to track through the western Great Lakes region.
Once again, model discrepancies that far out preclude more detail
on precipitation timing. However, it does appear that the weekend
will bring the warmest temperatures of the week to the region as
80 degree readings will be possible, especially across central and
east-central Wisconsin away from the lakeshore.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1229 PM CDT Mon May 13 2024

Smoke/haze drifting over the region this afternoon will reduce vsbys
down to low end VFR to MVFR conditions. Winds shifting around to the
northeast this evening should disperse the smoke and return vsbys
back to P6SM. Light to moderate NE winds and VFR conditions are then
expected overnight through the end of the TAF period.

There is a slight chance for a few vicinity rain showers this
afternoon and evening at MTW as on going showers currently along a
stalled frontal boundary in SE WI drift northeast. Don`t expect any
thunder with these shower.

&&

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

&&

$$

DISCUSSION.....GK/Kurimski
AVIATION.......GK