Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 05/11/21

Area Forecast Discussion

National Weather Service Green Bay WI

 1045 PM CDT Mon May 10 2021

Updated aviation portion for 06Z TAF issuance

.SHORT TERM...Tonight and Tuesday
Issued at 302 PM CDT Mon May 10 2021

There has been dense cloud cover across the area today with cold
air aloft and steep low and mid-level lapse rates. Water vapor
imagery at 1930Z indicated a shortwave was also moving over
northeast WI in association with the closed low across southern
Ontario. Isolated to scattered showers were once again developing
and evident on radar, however there have been few reports of
anything reaching the ground in the obs. There was a brief rain
shower reported in Manitowoc around 18Z, and a few sprinkles have
been noted just outside our office, too. Similar to the past
several days, expect diurnal showers to remain light and scattered
through early in the evening. Isolated graupel is also possible.
Showers will be most likely across northeast and east- central WI
closer to the forcing associated with the shortwave.

Tonight...Models are insistent on clearing the clouds out from
north to south from 00Z to 06Z this evening. A little uncertain
whether clearing will occur quite this rapidly due to how much
cloudiness is out there right now; but either way expect the
surface high, which as been situated around Manitoba, to shift
southeast towards WI overnight. This will eventually lead to
clearing skies and light winds, and as a result falling
temperatures. Have issued a Freeze Warning for most of the area
with lows expected to fall into the 20s to around 30 degrees. A
Frost Advisory was issued for the Fox Valley and east- central WI
were lows will range from about 31 to 34 degrees. Widespread frost
is likely across the forecast area.

Tuesday...Will start to see a change in the weather pattern as the
upper low which has been influencing the weather across the area
the past several days starts shifting east. High pressure
continues to build in at the surface which will lead to mostly
sunny skies and slightly warmer temperatures. Highs tomorrow will
be in the low 50s along the lakeshore and in the mid 50s to around
60 elsewhere.

.LONG TERM...Tuesday Night Through Monday
Issued at 302 PM CDT Mon May 10 2021

Upper level ridging and surface high pressure will keep the
weather dry during the middle part of this week. There appears to
be another round of frost/freeze headlines across the area Tuesday
night as lows fall into the 20s across the north, with lower to
middle 30s across central and east-central Wisconsin. Temperatures
then gradually warm throughout the week as the high shifts off to
the east, allowing warmer temperatures to advect into the region
and ending the threat for additional headlines.

The dry weather could come to an end late in the week and into the
weekend as the flow shifts to a more zonal pattern. Recent model
trends do indicate the chances for rain during this period could
be in question as a low pressure system approaching from the west
gets pushed a bit south and may only graze the southern portion of
the cwa. This part of the forecast will need to be monitored as
the system tracking back north will bring the precipitation back
into the region. The confidence and certainty in this portion of
the forecast is rather low given the lack of a strong low pressure
system to grasp onto. Temperatures during this period are expected
to rise to around or even slightly above normal for this time of
year.

Early next week there are indications that a more substantial low
pressure system could bring a round of moderate to heavy rain
somewhere across the western Great Lakes Sunday night into Monday.
However, like the previous period, confidence is rather low as not
all of the long term models indicate this will be the case.
&&

.AVIATION...for 06Z TAF Issuance
Issued at 1045 PM CDT Mon May 10 2021

VFR flight conditions will continue through Wednesday, with high
base cumulus clouds forming around midday and dissipating in the
evening.

When the skies clear tonight and Tuesday night temperatures will
fall and frost is likely on aircraft parked outside. Visibility
will be excellent through Wednesday.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Frost Advisory until 8 AM CDT Tuesday for WIZ022-038>040-048>050.

Freeze Warning until 8 AM CDT Tuesday for WIZ005-010>013-018>021-
030-031-035>037-045-073-074.
&&

$$

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