Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 05/10/21

Area Forecast Discussion

National Weather Service Green Bay WI

 626 PM CDT Sun May 9 2021

Updated aviation portion for 00Z TAF issuance

.SHORT TERM...Tonight and Monday
Issued at 322 PM CDT Sun May 9 2021

Similar to the past couple days, the main forecast challenges
revolve around cloud cover, daytime convective showers, and low
temps and frost/freeze headlines.

Late this afternoon...Most of the forecast area had broken cu
overhead, with more stable air in far east- central WI which was
resulting in less cloudiness. Surface analysis at 1930Z also
indicated a surface low located in southwest WI. Steep lapse rates
along with enhanced convergence near the low was resulting in
scattered precip returns showing up on radar, however, have yet to
see any ground truth in the obs. Given high cloud bases and
surface dewpoint depressions not sure how much will reach the
ground, but will continue to carry slight chance PoPs across
central and far northeast WI for the late afternoon and early
evening. Any showers will be light and brief.

Tonight...Daytime cu will slowly begin to dissipate. Then, a mid-
level shortwave will quickly move from South Dakota towards
southwest WI overnight, bringing in more clouds, particularly
over central WI. Less certain on forecast lows here, but for the
rest of the area there should be enough clearing for temps to fall
to near to below freezing. Used a blend of some of the better
performing guidance and adjusted for local effects. This resulted
in forecast lows ranging from the low to middle 20s in the
Northwoods, to the low to middle 30s across the Fox Valley and
east- central WI. Issued a Freeze Warning for counties mainly
north of Hwy 29, and  a Frost Advisory for all counties south.

Monday...Northerly flow over Lake Superior and cold advection
around 850mb will once again result in steep lapse rates and cloud
development during the late morning and afternoon. Forcing from a
500mb shortwave rotating across northeast WI during the afternoon
will bring a chance for scattered, light showers, too. Meanwhile,
CAA will lead to slightly cooler Max Ts tomorrow, ranging from
the upper 40s near the U.P. border and in the low to middle 50s
elsewhere.

.LONG TERM...Monday Night Through Sunday
Issued at 322 PM CDT Sun May 9 2021

Any remaining rain showers across northeast Wisconsin will quickly
dissipate early Monday evening with the loss of daytime heating.
Clearing skies and light winds will once again allow temperatures
to tank, with lows falling into the 20s across the north, upper
20s across central, and 30 to 35 across east-central Wisconsin.
This will mean additional frost/freeze headlines across the area
Monday night into Tuesday morning.

Cool air will remain in place on Tuesday despite mostly sunny
skies; however, the weather should stay dry as high pressure
builds in across the western Great Lakes. Clear skies and light
winds will once again allow temperatures to fall, with lows
Tuesday night falling into the middle to upper 20s across the
north, with lower to middle 30s across central and east-central
Wisconsin. These cold temperatures will likely once again
necessitate frost/freeze headlines across much if not the entire
area Tuesday night into Wednesday morning.

Temperatures will then gradually warm up during the middle to late
part of the week as the high shifts east, with the threat for
frost/freeze diminishing as the week wears on. The weather is also
forecast to stay dry through Thursday night as the high slowly
drifts off to the east.

The chance for rain will return late into the week and into next
weekend as several weak shortwaves track through the region. The
dynamics with these shortwaves will be fairly weak with meager
moisture; therefore, not much rain is expected from any showers
that develop during this time period. Warm air advection will also
allow temperatures to continue to rise during this period, with
highs expected to be a few degrees above normal by next weekend.
&&

.AVIATION...for 00Z TAF Issuance
Issued at 625 PM CDT Sun May 9 2021

Mid clouds with bases between 6000 and 8000 feet may produce some
virga or sprinkles before they slowly dissipate this evening.
Skies will clear first across north central Wisconsin and later
further south. Frost is possible on aircraft parked outside again
tonight.

Skies will start out mostly sunny Monday with high based clouds
forming by midday and continuing into the evening. Some sprinkles
or brief rain showers are not out of the question.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Frost Advisory from midnight tonight to 8 AM CDT Monday for
WIZ022-035>040-045-048>050.

Freeze Warning from midnight tonight to 8 AM CDT Monday for
WIZ005-010>013-018>021-030-031-073-074.
&&

$$

SHORT TERM.....KLJ
LONG TERM......Kurimski
AVIATION.......RDM