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000
FXUS63 KGRB 300441
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1141 PM CDT SUN MAY 29 2016

Updated aviation portion for 06Z TAF issuance

.SHORT TERM...Tonight and Monday
Issued at 335 PM CDT Sun May 29 2016

Showers, and possibly a couple of thunderstorms, continued to make
their way across the forecast area as a mid level trough and a
cold front pushed east of Wisconsin. Models showed some mid level
short wave energy passing through the state during the evening,
but it looks like it will be far enough to the south to keep any
rain associated with it out of this area. Surface high pressure
and an upstream mid level ridge should keep the rest of the night
and Memorial Day dry. There could be some fog during the night as
clouds dissipate and winds weaken. Heavier rain across central and
north central Wisconsin the past 24 hours make those areas the
more likely spots for any fog formation.

Blended the previous forecast temperatures with a couple of the
better performing guidance sets. Looks like warmer than normal
temperatures but less humid for Memorial Day.

.LONG TERM...Monday Night Through Sunday
Issued at 335 PM CDT Sun May 29 2016

A quiet night expected for much of Monday night as a weak ridge
passes eastward. Return flow on the backside will increase clouds
overnight with progs persistent with convection possibly making
back into central Wisconsin toward Tuesday morning.

Precipitation chances will continue to be on the increase tuesday
into Tuesday night as an 850 mb and surface front slowly work
across the state from west to east. Pwats climb back into the
1.50 inch range by Tuesday evening while the rrq region of the
upper jet drifts into the state from the west. Combination of
increasingly moist unstable air mass with some forcing could lead
to some strong to severe storms. But more than likely with the
slowly frontal movement and plume of moisture working into the
area...a period of heavy rain possible from tuesday into wednesday.

Progs fairly similar with timing the surface front departing east
of the area late Wednesday afternoon or evening to start a trend
to diminish the convection.

The Northern Plains and Western Great Lakes region returns to
more of a upper northwest flow pattern...with a trend toward
slightly cooler and drier conditions. Will continue the chance
for afternoon diurnal showers Thursday due to the cyclonic flow
aloft.

The northwest flow turns more noisy next weekend with a few short
waves sliding southeast over the area. The primary system appears
toward saturday into saturday night with both the GFS and ECMWF
very similar with an 850 trough tracking through the area.
&&

.AVIATION...for 06Z TAF Issuance
Issued at 1139 PM CDT Sun May 29 2016

Still isolated showers in central WI, but those should end/exit
the area soon. Main aviation forecast concern is still fog
potential. West winds and the arrival of drier air will work
against fog, but lingering surface moisture from recent rains and
diminishing winds near surface high will be favorable. Will limit
fog to just central and north-central Wisconsin. Trends this
evening suggest north-central WI will have the better fog
potential, so will structure TAFs accordingly.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....MG
LONG TERM......TDH
AVIATION.......Skowronski





000
FXUS63 KGRB 282306
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
606 PM CDT SAT MAY 28 2016

Updated aviation portion for 00Z TAF issuance

.SHORT TERM...Tonight and Sunday
Issued at 324 PM CDT Sat May 28 2016

Showers and thunderstorms are the main concerns in the short
term.

A 500mb trough over the Plains today was forecast to move into
Wisconsin during the night, and a surface low to the west of the
area was to reach the northwest shores of Lake Superior by 12Z
Sunday. Mesoanalysis indicated at least 500J/kg of MUCAPE over
most of the forecast area, with in excess of 1,000 J/kg in parts
of central/north central Wisconsin. There was little to no CIN.
Radar mosaic time lapse showed showers and some thunderstorms,
from western upper Michigan across Wisconsin into Southeast
Minnesota/Iowa, moving north. Convection across the forecast area
was mainly focused in the vicinity of a warm front in north
central Wisconsin and a stationary front in western Wisconsin.

Would expect an increase in showers and storms during the late
afternoon and early evening, with rain continuing during the
night, mainly across the northwest 2/3rds of the forecast area.
There is a better chance for showers and storms over the remainder
of the area on Sunday as the surface low drags a cold front
across the state while the 500mb trough moves through Wisconsin.

Used a blend of the previous forecast and the some of the better
performing guidance numbers for lows tonight and highs on Sunday.

.LONG TERM...Sunday Night Through Saturday
Issued at 324 PM CDT Sat May 28 2016

Precipitation chances will be on the decline Sunday evening as a
mid level short wave with surface cold front shifts east of the
area. A ridge of high pressure quickly builds into the region for
Monday for overall quiet weather. This ridge was in advance of
Pacific trough of low pressure working into the Northern Plains.

Precipitation chances expected to be back on the increase late
Monday night into Tuesday as the Northern Plains upper trough and
frontal system tracks into the western Great Lakes region.
Convection expected to be on the increase over southwest
Wisconsin Monday night with a warm front lifting northward. Some
of this convection may reach central Wisconsin Monday
night...otherwise the models are in good agreement with the brunt
of this convection spreading over the area Tuesday into Tuesday
night. Scattered convection may be ongoing Wednesday over eastern
Wisconsin and in an occluded frontal region...and east of a dry
slot working into much of Minnesota and the western half of
Wisconsin. Another round of showers possible with the upper low
system and a secondary cool front passing over Wednesday night
into Thursday. The most recent GFS has quickened the departure of
this upper system for Thursday and therefore drier that the
lagging upper trough ECMWF solution.

The broad upper ridge builds over the western states late in the
week and into the weekend leaving the area in a northwest flow
regime. Medium range progs attempt to drop weak short waves over
the region Friday and Saturday in this northwest flow. Any
precipitation mention during this period will likely be minor and
more of the diurnal variety.
&&

.AVIATION...for 00Z TAF Issuance
Issued at 603 PM CDT Sat May 28 2016

Cluster of thunderstorms headed NE from south-central WI will
likely pass across east-central WI this evening. Additional
development to the west will likely move across the rest of the
area. T/Td spreads much larger than yesterday at this time,
indicating it will take longer for low ceilings to develop across
the area tonight. Will maintain fairly good flight conditions
(outside of thunderstorms) across the area this evening, then
allow ceilings to lower after midnight.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....MG
LONG TERM......TDH
AVIATION.......Skowronski





000
FXUS63 KGRB 281150
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
650 AM CDT SAT MAY 28 2016

Updated aviation portion for 12Z TAF issuance

.SHORT TERM...Today...Tonight...and Sunday
Issued at 346 AM CDT Sat May 28 2016

Precipitation trends, potential for severe tstms and temperatures
will be the main fcst concerns.

An upper low over Nebraska and Kansas will move northeast into
western MN later today. Ahead of this feature, a short-wave trof
(currently over southwest WI) will lift north through the western
half of the forecast area this morning. In addition, a weak
surface low is expected to move toward north central WI, and pull
a warm front (currently situated over central WI) northward with
it. Expect the greatest pcpn coverage to occur across the
northwest half of the forecast area this morning, in association
with the s/w trof and sfc low. Partial clearing is possible over
the southeast part of the fcst area this afternoon, which should
result in enough destabilization (CAPE of 500-700 j/kg) for
scattered tstm development, especially near the lingering warm
frontal boundary. There is a marginal severe weather threat across
the region, and the best bet would with any discrete storms that
can develop near the warm front. It is difficult to say where the
front will reside this afternoon, but most models suggest
somewhere in north central and northeast WI.

Convection should weaken and decrease in coverage this evening,
as daytime instability wanes. However, showers and sct tstms will
increase again over nc/c WI overnight as a sharp upper trof pushes
into western WI. The trof and an associated cold front will sweep
across the forecast area on Sunday, bringing numerous showers and
sct tstms.

Used a blend of the better performing guidance sets for
temperatures the next couple days, but cloud and pcpn trends
will ultimately determine how warm we will get. Most places
should see highs in the 70s.

.LONG TERM...Sunday Night Through Friday
Issued at 346 AM CDT Sat May 28 2016

Mean flow to briefly go nearly zonal early next week, however the
development of a Western CONUS upper ridge is expected to have a
downstream shortwave trough develop and move east across the
northern tier of states toward mid-week. The timing of this
shortwave trough (and its associated cold front) into the Great
Lakes with precipitation chances to now be the main focus of the
extended forecast. Cooler/drier air is then expected for later
next week as surface high pressure builds into the region.

Any spotty leftover shower/thunderstorm activity from the exiting
initial shortwave trough should end early Sunday evening across
the north. Otherwise, expect to see decreasing clouds and light
winds over the region during the overnight hours which may allow
for some late night fog to develop. Min temperatures to be in the
lower 50s north, mid to upper 50s south. Weak area of high
pressure to be in our general vicinity for Memorial Day, however
there appears to be enough low-level moisture around such that
daytime heating may increase instability parameters in the
afternoon. While a stray shower or thunderstorm cannot be
completely ruled out, feel the instability may not be strong
enough to all precipitation to develop, thus have kept Memorial
Day dry for now. Max temperatures to range from the mid to upper
70s north/lakeshore, to the upper 70s to lower 80s south.

Attention then turns to the west, where a new shortwave trough is
forecast to be moving across the northern High Plains Monday
night. A SW flow aloft is expected to develop across the Plains/
Midwest with moisture beginning to get lifted toward WI. Models
indicate this moisture will interact with a warm front draped from
SW MN into IA to generate a new round of showers/thunderstorms.
Most of this activity should stay to our south and west Monday
night, however will probably need to carry a minimal pop for our
SW counties, especially after midnight. Otherwise, look for some
increase in clouds overnight with min temperatures around 50
degrees north, mid 50s south. This band of showers and
thunderstorms are forecast to lift newd and gradually overspread
NE WI on Tuesday as the warm front moves into WI and several
shortwaves lift into the region within the SW flow aloft. Highest
pops placed over central WI where the precipitation will reach
first and these values may need to be raised further once
confidence in timing gets better. Thicker clouds and advancing
precipitation will limit diurnal heating with max temperatures on
Tuesday ranging from around 70 degrees near Lake MI, lower to
middle 70s north and middle to upper 70s south.

Shower and thunderstorm chances still look good into Tuesday night
as the shortwave trough pushes across the northern Plains and a
cold front preceding the trough moves into roughly western WI by
12z Wednesday. While the models agree in taking the shortwave
trough eastward into the Upper MS Valley on Wednesday, they begin
to diverge with the forward speed of the cold front and potential
for a dry slot to rotate into WI. The GEM sides with the ECMWF as
far as the dry slot goes, but with the cold front expected to be
pushing across the state, hard to buy into the dry forecast these
two models are showing. May attempt to lower pop values down a bit
compared to the previous forecast, but not drop pops altogether.
Max temperatures on Wednesday should be a couple of degrees cooler
than Tue with upper 60s near Lake MI, lower 70s north and mainly
mid 70s south.

Precipitation trends should begin to diminish to a certain degree
as the cold front shoves farther to the east Wednesday night into
Thursday. However, the trailing shortwave trough is progged to
reach the Western Great Lakes on Thursday, so the big question is
whether there will be any moisture left over the region or will
the cold front have taken all the moisture east with it?
Typically, cold fronts do a good job in stripping the best low-
level moisture, leaving nothing behind for any trailing surface
boundary or mid-level system. May end up with a token pop just in
case the air mass aloft cools enough to steepen lapse rates.

By the end of the work week, NE WI to reside under a NW flow aloft
with an area of high pressure building into the region. Do not see
enough evidence of any triggering mechanism for precipitation,
thus would like to go dry on Friday. Temperatures by the end of
the week could actually drop close to, if not a degree or two
below normal.
&&

.AVIATION...for 12Z TAF Issuance
Issued at 644 AM CDT Sat May 28 2016

An upper level disturbance and surface warm front will combine to
produce showers and a few tstms over the region this morning.
flight conditions should improve to mvfr/local vfr for a while
after the rain tapers off. Additional showers and storms should
develop later this afternoon and early evening, especially near
the warm front. expect flight conditions to deteriorate again
tonight, as areas of low stratus and fog redevelop.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....Kieckbusch
LONG TERM......Kallas
AVIATION.......Kieckbusch





000
FXUS63 KGRB 280847
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
347 AM CDT SAT MAY 28 2016

Forecast discussion for routine morning forecast issuance

.SHORT TERM...Today...Tonight...and Sunday
Issued at 346 AM CDT Sat May 28 2016

Precipitation trends, potential for severe tstms and temperatures
will be the main fcst concerns.

An upper low over Nebraska and Kansas will move northeast into
western MN later today. Ahead of this feature, a short-wave trof
(currently over southwest WI) will lift north through the western
half of the forecast area this morning. In addition, a weak
surface low is expected to move toward north central WI, and pull
a warm front (currently situated over central WI) northward with
it. Expect the greatest pcpn coverage to occur across the
northwest half of the forecast area this morning, in association
with the s/w trof and sfc low. Partial clearing is possible over
the southeast part of the fcst area this afternoon, which should
result in enough destabilization (CAPE of 500-700 j/kg) for
scattered tstm development, especially near the lingering warm
frontal boundary. There is a marginal severe weather threat across
the region, and the best bet would with any discrete storms that
can develop near the warm front. It is difficult to say where the
front will reside this afternoon, but most models suggest
somewhere in north central and northeast WI.

Convection should weaken and decrease in coverage this evening,
as daytime instability wanes. However, showers and sct tstms will
increase again over nc/c WI overnight as a sharp upper trof pushes
into western WI. The trof and an associated cold front will sweep
across the forecast area on Sunday, bringing numerous showers and
sct tstms.

Used a blend of the better performing guidance sets for
temperatures the next couple days, but cloud and pcpn trends
will ultimately determine how warm we will get. Most places
should see highs in the 70s.

.LONG TERM...Sunday Night Through Friday
Issued at 346 AM CDT Sat May 28 2016

Mean flow to briefly go nearly zonal early next week, however the
development of a Western CONUS upper ridge is expected to have a
downstream shortwave trough develop and move east across the
northern tier of states toward mid-week. The timing of this
shortwave trough (and its associated cold front) into the Great
Lakes with precipitation chances to now be the main focus of the
extended forecast. Cooler/drier air is then expected for later
next week as surface high pressure builds into the region.

Any spotty leftover shower/thunderstorm activity from the exiting
initial shortwave trough should end early Sunday evening across
the north. Otherwise, expect to see decreasing clouds and light
winds over the region during the overnight hours which may allow
for some late night fog to develop. Min temperatures to be in the
lower 50s north, mid to upper 50s south. Weak area of high
pressure to be in our general vicinity for Memorial Day, however
there appears to be enough low-level moisture around such that
daytime heating may increase instability parameters in the
afternoon. While a stray shower or thunderstorm cannot be
completely ruled out, feel the instability may not be strong
enough to all precipitation to develop, thus have kept Memorial
Day dry for now. Max temperatures to range from the mid to upper
70s north/lakeshore, to the upper 70s to lower 80s south.

Attention then turns to the west, where a new shortwave trough is
forecast to be moving across the northern High Plains Monday
night. A SW flow aloft is expected to develop across the Plains/
Midwest with moisture beginning to get lifted toward WI. Models
indicate this moisture will interact with a warm front draped from
SW MN into IA to generate a new round of showers/thunderstorms.
Most of this activity should stay to our south and west Monday
night, however will probably need to carry a minimal pop for our
SW counties, especially after midnight. Otherwise, look for some
increase in clouds overnight with min temperatures around 50
degrees north, mid 50s south. This band of showers and
thunderstorms are forecast to lift newd and gradually overspread
NE WI on Tuesday as the warm front moves into WI and several
shortwaves lift into the region within the SW flow aloft. Highest
pops placed over central WI where the precipitation will reach
first and these values may need to be raised further once
confidence in timing gets better. Thicker clouds and advancing
precipitation will limit diurnal heating with max temperatures on
Tuesday ranging from around 70 degrees near Lake MI, lower to
middle 70s north and middle to upper 70s south.

Shower and thunderstorm chances still look good into Tuesday night
as the shortwave trough pushes across the northern Plains and a
cold front preceding the trough moves into roughly western WI by
12z Wednesday. While the models agree in taking the shortwave
trough eastward into the Upper MS Valley on Wednesday, they begin
to diverge with the forward speed of the cold front and potential
for a dry slot to rotate into WI. The GEM sides with the ECMWF as
far as the dry slot goes, but with the cold front expected to be
pushing across the state, hard to buy into the dry forecast these
two models are showing. May attempt to lower pop values down a bit
compared to the previous forecast, but not drop pops altogether.
Max temperatures on Wednesday should be a couple of degrees cooler
than Tue with upper 60s near Lake MI, lower 70s north and mainly
mid 70s south.

Precipitation trends should begin to diminish to a certain degree
as the cold front shoves farther to the east Wednesday night into
Thursday. However, the trailing shortwave trough is progged to
reach the Western Great Lakes on Thursday, so the big question is
whether there will be any moisture left over the region or will
the cold front have taken all the moisture east with it?
Typically, cold fronts do a good job in stripping the best low-
level moisture, leaving nothing behind for any trailing surface
boundary or mid-level system. May end up with a token pop just in
case the air mass aloft cools enough to steepen lapse rates.

By the end of the work week, NE WI to reside under a NW flow aloft
with an area of high pressure building into the region. Do not see
enough evidence of any triggering mechanism for precipitation,
thus would like to go dry on Friday. Temperatures by the end of
the week could actually drop close to, if not a degree or two
below normal.
&&

.AVIATION...for 06Z TAF Issuance
Issued at 856 PM CDT Fri May 27 2016

After the recent rains and with a humid air mass across the area,
expect flight conditions to deteriorate significantly overnight.
But confidence in how widespread the fog becomes is very low. Plan
to stick close to the scenario in the current TAFs.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....Kieckbusch
LONG TERM......Kallas
AVIATION.......Skowronski





000
FXUS63 KGRB 271145
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
645 AM CDT FRI MAY 27 2016

Updated aviation portion for 12Z TAF issuance

.SHORT TERM...Today...Tonight...and Saturday
Issued at 348 AM CDT Fri May 27 2016

Precipitation trends and temperatures are the main fcst concerns.

Ridging aloft brought dry conditions early this morning, with
mainly high clouds impacting the area. Light winds and abundant
low-level moisture was resulting in patchy fog development.
Regional radar mosaic showed showers and a few tstms developing
over southeast MN, eastern IA and northwest IL, in response to
increasing waa and moisture convergence, and a short-wave trof.

Patchy/areas of fog will dissipate early in the day. The band of
showers and embedded tstms is expected to arrive a little slower
than was previously advertised. Most of the meso-models suggest
that pcpn will hold off until around 15z in central WI, then
surge northeast as sfc/H8 warm fronts arrive in the late morning
and afternoon. Will carry likely pops for most of the fcst area,
with chance pops in our far eastern counties. Not expecting any
severe tstms, as instability will be weaker than the previous
couple days. Used a blend of the better performing guidance sets
for high temps, which yielded mid 70s to lower 80s, except upper
60s and lower 70s near the lakeshore.

It will be difficult to nail down specific pcpn trends tonight
into Saturday, due to a lack of significant dynamic forcing.
However, a very moist air mass will return to the region, with
precipitable water values increasing to 1.5 to 1.75 inches, so
it won`t take much to generate showers and sct tstms. Will
continue to carry high chance/likely pops over the entire fcst
area. There are some indications that another warm front will
lift into central WI Saturday afternoon, as low pressure moves
into the northwest part of the state. A dry slot may provide
partial clearing over c/ec WI in the afternoon, allowing
instability to build near the frontal boundary. With CAPE
increasing to 800-1200 j/kg, and deep layer shear of 30 to 35 kts,
will need to monitor for another round of isold severe tstms. High
temperatures should be in the 75 to 80 range away from Lake
Michigan.

.LONG TERM...Saturday Night Through Thursday
Issued at 348 AM CDT Fri May 27 2016

A prevailing SW flow aloft will continue into WI through Sunday
night, thanks to a shortwave trough that is expected to move from
the Central Plains through the Great Lakes. Expect to see
unsettled weather persist until this trough exits the region with
conditions becoming more stable as the mean flow turns more
westerly. Models show an upper ridge developing over the Western
CONUS early to middle part of next week and this will allow for a
downstream shortwave trough to push east across the northern tier
of states. This system would bring the next chance of showers/
thunderstorms to NE WI late on Tuesday into Wednesday.
Temperatures are forecast to remain above normal through mid-week
and then fall to or slightly below normal next Thursday.

The initial shortwave trough is forecast to move from the Central
Plains northeast to the Upper MS Valley/Midwest Saturday night and
into the Great Lakes on Sunday. This trough will be accompanied by
an eastward moving cold front that is expected to push across WI
on Sunday. Plenty of low-level moisture to be in place with dew
points in the upper 50s to lower 60s and with the lift provided by
the cold front and sufficient mid-level forcing provided by the
shortwave trough, anticipate at least a couple rounds of showers
and thunderstorms to move through the region during the Saturday
night/Sunday time frame. Look for min temperatures Saturday night
to be in the mid to upper 50s north/lakeshore, lower to middle
60s south. Max temperatures for Sunday should reach the mid to
upper 70s north, upper 70s to around 80 degrees south (cooler
lakeside).

Any lingering precipitation chances into Sunday evening should
come to an end as the cold front pushes east and the shortwave
trough continues to track northeast into Canada. The rest of
Sunday night and most of Memorial Day appear to be dry at the
moment with a weak area of high pressure drifting through the
region. The only concern for precipitation would be Monday
afternoon roughly over the southern half of the state where
instability increases and there is an upper diffluent flow aloft.
Will probably end up keeping a small pop over central/east-central
WI on Memorial Day for now. Sunday night`s min temperatures will
cool a bit with some clearing taking place as readings drop into
the 50-55 degree range north, 55-60 degree range south. Max
temperatures though on Memorial Day should again return to
readings similar to Sunday`s.

Any spotty precipitation chances would remain over southern
sections of WI Monday night, but shower/thunderstorm chances are
expected to increase on Tuesday as the next shortwave trough rolls
across the Northern Rockies. Winds will turn to the S-SE and begin
to pull gulf moisture northward toward WI. Modest isentropic lift
to be the primary mechanism for these precipitation chances on
Tuesday, but with the main forcing still well to our west, have
kept pops fairly low through 00z Wednesday. Increasing clouds
should balance the WAA, thus max temperatures on Tuesday to range
from the upper 60s to lower 70s near Lake MI, to the upper 70s
over parts of Central WI.

This latest shortwave trough is progged to move across the
Northern Plains Tuesday night and head toward the Upper MS Valley
by late Wednesday. A cold front is expected to preclude this
shortwave trough with the models showing this front possibly
reaching Western WI by 00z Thursday. While the timing of both of
these weather systems could change in the coming days, there
should be enough isentropic lift and mid-level forcing to provide
a good chance of showers/thunderstorms across NE WI Tuesday night
into Wednesday. Forecast becomes more uncertain thereafter as the
ECMWF is rather progressive with this system, whereas the GFS is
much slower. It appears that the GFS maintains a much stronger
Eastern CONUS upper ridge which would slow the upstream shortwave
trough. This is evident with the dry ECMWF versus wet GFS for
Wednesday night and Thursday. Fully expect the models to wrestle
with this scenario in the days to come, so have used the consensus
solution which keeps small chc pops for both Wednesday and
Thursday.
&&

.AVIATION...for 12Z TAF Issuance
Issued at 637 AM CDT Fri May 27 2016

BANDS OF SHOWERS AND SCT TSTMS WILL LIFT NORTH INTO THE REGION AS
A WARM FRONT APPROACHES. THE FIRST BAND WILL SHIFT THROUGH C/NC WI
THIS MORNING, BUT ACCURATELY TIMING SUBSEQUENT PERIODS OF SHOWERS
WILL BE A REAL PROBLEM. EXPECT MAINLY VFR AND PATCHY MVFR
CONDITIONS DURING THE DAY, WITH FLIGHT CONDITIONS GRADUALLY
DETERIORATING TO IFR AND PATCHY LIFR OVERNIGHT. CONFIDENCE IN THE
TIMING AND OCCURRENCE OF TSTMS WAS TOO LOW TO MENTION IN THE TAFS
RIGHT NOW.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....Kieckbusch
LONG TERM......Kallas
AVIATION.......Kieckbusch





000
FXUS63 KGRB 270849
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
349 AM CDT FRI MAY 27 2016

Forecast discussion for routine morning forecast issuance

.SHORT TERM...Today...Tonight...and Saturday
Issued at 348 AM CDT Fri May 27 2016

Precipitation trends and temperatures are the main fcst concerns.

Ridging aloft brought dry conditions early this morning, with
mainly high clouds impacting the area. Light winds and abundant
low-level moisture was resulting in patchy fog development.
Regional radar mosaic showed showers and a few tstms developing
over southeast MN, eastern IA and northwest IL, in response to
increasing waa and moisture convergence, and a short-wave trof.

Patchy/areas of fog will dissipate early in the day. The band of
showers and embedded tstms is expected to arrive a little slower
than was previously advertised. Most of the meso-models suggest
that pcpn will hold off until around 15z in central WI, then
surge northeast as sfc/H8 warm fronts arrive in the late morning
and afternoon. Will carry likely pops for most of the fcst area,
with chance pops in our far eastern counties. Not expecting any
severe tstms, as instability will be weaker than the previous
couple days. Used a blend of the better performing guidance sets
for high temps, which yielded mid 70s to lower 80s, except upper
60s and lower 70s near the lakeshore.

It will be difficult to nail down specific pcpn trends tonight
into Saturday, due to a lack of significant dynamic forcing.
However, a very moist air mass will return to the region, with
precipitable water values increasing to 1.5 to 1.75 inches, so
it won`t take much to generate showers and sct tstms. Will
continue to carry high chance/likely pops over the entire fcst
area. There are some indications that another warm front will
lift into central WI Saturday afternoon, as low pressure moves
into the northwest part of the state. A dry slot may provide
partial clearing over c/ec WI in the afternoon, allowing
instability to build near the frontal boundary. With CAPE
increasing to 800-1200 j/kg, and deep layer shear of 30 to 35 kts,
will need to monitor for another round of isold severe tstms. High
temperatures should be in the 75 to 80 range away from Lake
Michigan.

.LONG TERM...Saturday Night Through Thursday
Issued at 348 AM CDT Fri May 27 2016

A prevailing SW flow aloft will continue into WI through Sunday
night, thanks to a shortwave trough that is expected to move from
the Central Plains through the Great Lakes. Expect to see
unsettled weather persist until this trough exits the region with
conditions becoming more stable as the mean flow turns more
westerly. Models show an upper ridge developing over the Western
CONUS early to middle part of next week and this will allow for a
downstream shortwave trough to push east across the northern tier
of states. This system would bring the next chance of showers/
thunderstorms to NE WI late on Tuesday into Wednesday.
Temperatures are forecast to remain above normal through mid-week
and then fall to or slightly below normal next Thursday.

The initial shortwave trough is forecast to move from the Central
Plains northeast to the Upper MS Valley/Midwest Saturday night and
into the Great Lakes on Sunday. This trough will be accompanied by
an eastward moving cold front that is expected to push across WI
on Sunday. Plenty of low-level moisture to be in place with dew
points in the upper 50s to lower 60s and with the lift provided by
the cold front and sufficient mid-level forcing provided by the
shortwave trough, anticipate at least a couple rounds of showers
and thunderstorms to move through the region during the Saturday
night/Sunday time frame. Look for min temperatures Saturday night
to be in the mid to upper 50s north/lakeshore, lower to middle
60s south. Max temperatures for Sunday should reach the mid to
upper 70s north, upper 70s to around 80 degrees south (cooler
lakeside).

Any lingering precipitation chances into Sunday evening should
come to an end as the cold front pushes east and the shortwave
trough continues to track northeast into Canada. The rest of
Sunday night and most of Memorial Day appear to be dry at the
moment with a weak area of high pressure drifting through the
region. The only concern for precipitation would be Monday
afternoon roughly over the southern half of the state where
instability increases and there is an upper diffluent flow aloft.
Will probably end up keeping a small pop over central/east-central
WI on Memorial Day for now. Sunday night`s min temperatures will
cool a bit with some clearing taking place as readings drop into
the 50-55 degree range north, 55-60 degree range south. Max
temperatures though on Memorial Day should again return to
readings similar to Sunday`s.

Any spotty precipitation chances would remain over southern
sections of WI Monday night, but shower/thunderstorm chances are
expected to increase on Tuesday as the next shortwave trough rolls
across the Northern Rockies. Winds will turn to the S-SE and begin
to pull gulf moisture northward toward WI. Modest isentropic lift
to be the primary mechanism for these precipitation chances on
Tuesday, but with the main forcing still well to our west, have
kept pops fairly low through 00z Wednesday. Increasing clouds
should balance the WAA, thus max temperatures on Tuesday to range
from the upper 60s to lower 70s near Lake MI, to the upper 70s
over parts of Central WI.

This latest shortwave trough is progged to move across the
Northern Plains Tuesday night and head toward the Upper MS Valley
by late Wednesday. A cold front is expected to preclude this
shortwave trough with the models showing this front possibly
reaching Western WI by 00z Thursday. While the timing of both of
these weather systems could change in the coming days, there
should be enough isentropic lift and mid-level forcing to provide
a good chance of showers/thunderstorms across NE WI Tuesday night
into Wednesday. Forecast becomes more uncertain thereafter as the
ECMWF is rather progressive with this system, whereas the GFS is
much slower. It appears that the GFS maintains a much stronger
Eastern CONUS upper ridge which would slow the upstream shortwave
trough. This is evident with the dry ECMWF versus wet GFS for
Wednesday night and Thursday. Fully expect the models to wrestle
with this scenario in the days to come, so have used the consensus
solution which keeps small chc pops for both Wednesday and
Thursday.
&&

.AVIATION...for 06Z TAF Issuance
Issued at 1040 PM CDT Thu May 26 2016

low clouds and fog are possible later tonight and
early friday. ifr conditions are possible from 09z through 13z in
some areas. a warm front will lift northeast across wisconsin
friday bringing showers and thunderstorms to the area by friday
afternoon and evening.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....Kieckbusch
LONG TERM......Kallas
AVIATION.......RDM





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