FXUS63 KMKX 220810
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
310 AM CDT Sun Jul 22 2018
Today into Tonight...Forecast Confidence is High...
Looks like we will have another day stuck in the western
periphery of the stacked trough/low with scattered showers and
extensive cloud cover for much of the day. Lift is pretty tame,
but just enough in the 600-500mb range to keep these random light
rain showers/drizzle going across southern Wisconsin. Looks like
there should be one last uptick in activity toward this afternoon
as another mid level shortwave trough propagates south along Lake
Michigan per the 22.06z RAP/NAM. There does appear to be some weak
instability (~500J/kg MUCAPE) that develops this afternoon, so
can not completely rule out a stray thunderstorm though it should
stay fairly isolated. High temperatures could be a bit tricky as
they stayed in the low 70s under cloud cover yesterday but then
popped up into the low 80s where some sun was able to peak out in
western WI. Went somewhere in-between in the mid 70s but could
get warmer if it clears out earlier than expected. Going into
tonight, there does appear to be some clearing that takes place as
the mid level trough flattens out and shifts eastward finally.
Monday through Wednesday - Confidence...Medium
Expecting a quiet period with main upper low to our east lifting
to the north with mid level flow taking on a more of a
west/northwest look. In the low levels the flow will be largely
anticyclonic. A cool front draws closer Wednesday though remains
far enough to our northwest to keep the area dry for much of
Wednesday. Some small pops are in place for the far northwest cwa
during the afternoon. However this is low confidence with the
latest ECMWF showing a much slower solution with the proggd precip
much further northwest than the GFS by days end Wednesday. 925
temps nudge up into the low/mid 20s celsius Wednesday ahead of
Wednesday night - Confidence...Medium
Potent 500 millibar low is proggd to traverse will be traversing
towards the MN arrowhead with some vorticity trailing south with
mid/upper level speed max impinging into the area on the southern
flank of the circulation. Surface/850 front in combo with some of
this upper support may set off a few showers/storms.
Thursday through Saturday - Confidence...Medium
Broad northwest cyclonic flow will be across the area with low
level thermal troughing. Some vorticity maxima moving through may
combine with low level trough to generate some shra or tsra about
Friday. Temps drop back into the 70s for much of this period with
925 temps back into the teens celsius.
.AVIATION(09Z TAFS)...Widespread MVFR to localized IFR ceilings
are occurring across southern Wisconsin with more of the 500-900ft
cigs in place closer to Lake Michigan. These conditions are
expected to persist through about mid-morning before gradually
improving into the afternoon. Some scattered showers and an
isolated thunderstorm are expected today which could briefly bring
visibilities down. Skies are expected to clear out tonight and
bring conditions back to VFR.
.MARINE...Small Craft Advisory runs through 5pm today due to the high
wave conditions. While winds are and will be slightly lower today than
what they were yesterday, the persistent fetch out of the north-
northeast will keep waves up in the 3-6ft range today. Winds will
continue to diminish into Monday and shift to the northwest which
will allow for the waves to gradually weaken. High pressure is
expected to move into the region and help to keep the wave action
down for much of next week.
.BEACHES...Persistent north to northeast winds over Lake Michigan have
lead to some high waves of up to 6 feet along the Wisconsin coast line.
While winds will not be as strong today, they will remain out of the
same direction and help to maintain the high waves and dangerous swimming
conditions. Winds should shift to the northwest on Monday and lighten
up and help to end the dangerous swimming conditions.
WI...Beach Hazards Statement through this afternoon for WIZ052-060-
LM...Small Craft Advisory until 5 PM CDT this afternoon for
Today/Tonight and Aviation/Marine...Halbach
Monday through Saturday...Collar
FXUS63 KARX 220736
Area Forecast Discussion
National Weather Service La Crosse WI
236 AM CDT Sun Jul 22 2018
.SHORT TERM...(Today and tonight)
Issued at 236 AM CDT Sun Jul 22 2018
Main forecast concerns are on chances for isolated showers mainly
over central Wisconsin through tonight.
Low pressure over centered over the Ohio River Valley will continue
to edge south today. A shortwave rotating around the low could
bring isolated showers to portions of Wisconsin today. It appears
that the main shortwave will move through this afternoon into this
evening but any showers look to be confined to area east of the
Mississippi River. High pressure then edges into to the Upper
Mississippi River Valley late tonight into Monday with quiet
weather expected across the area. Plan on highs today ranging from
the upper 70s to around 80 with lows falling into the mid 50s to
lower 60s. There will be more cloud cover across western and
central Wisconsin today thanks to the shortwave moving through
.LONG TERM...(Monday through Saturday)
Issued at 236 AM CDT Sun Jul 22 2018
A weak frontal boundary moves into the region from the west on
Monday as low pressure occludes over northern Manitoba. Given the
timing of the front into western sections of the forecast area,
it appears it won't produce much if any precipitation in the area.
Forecast models are generating some very light precipitation over
portions of northeast Iowa and southeast Minnesota Monday into
Monday evening but CAPE will be diminishing during the evening
hours so if any of this activity makes it into the area it would
be confined to far western sections of the forecast area. Will
keep low chances for showers and thunderstorms over these areas.
High pressure returns for Tuesday with dry and quiet weather
expected. Higher chances for showers and thunderstorms arrive
Wednesday afternoon as an upper trough and cold front drives
through the region. Cannot rule out the potential for a strong to
severe thunderstorm Wednesday afternoon and evening as MUCAPE
values climb to around 1500 J/kg and 0-6 km bulk shear increases
to around 30 kts during the afternoon, increasing to 40 kts by
late evening. Broad upper level troughing then sets up across the
western Great Lakes and Upper Mississippi River Valley Wednesday
night into Thursday and persists over the region into the weekend.
This will lead to slightly below normal temperatures and the
potential to see a few showers at times as weak shortwaves move
through the trough.
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1142 PM CDT Sat Jul 21 2018
As expected, with the loss of the daytime heating, the clouds over
the area have dissipated with clear skies over much of the region.
The clouds trapped in the cyclonic flow are not that far away from
the area and are still expected to rotate back into the area late
tonight through Sunday as a short wave trough rotates around the
back side of the upper level low. These clouds will likely bring a
VFR ceiling into KLSE for much of Sunday with mainly scattered VFR
clouds for KRST.
FXUS63 KGRB 220828
Area Forecast Discussion
National Weather Service Green Bay WI
328 AM CDT Sun Jul 22 2018
Forecast discussion for routine morning forecast issuance
.SHORT TERM...Today...Tonight...and Monday
Issued at 318 AM CDT Sun Jul 22 2018
Lingering cyclonic flow and remaining deep moisture across the
western Great Lakes will keep the chance for light rain showers
across the area today as shortwaves continue to move around a
large upper level low situated over the southern Great Lakes
region. Modest instability will also remain, however it should
only produce shower activity with a fairly low chance for
lightning as MUCAPEs are less than 500 J/kg. This instability
lingers across central Wisconsin during the evening hours,
therefore will keep small POPs in across this area during that
time period. Periods of sun will allow temperatures to rise to
around 80 degrees away from the Lake this afternoon.
Drier air and shortwave ridging will work their way into the
region later this evening and into the overnight hours, which
should end the chance for rain and bring clearing skies to the
area. Overnight lows are expected to plummet into the 50s across
the north, with lows around 60 degrees elsewhere.
By Monday the ridging flattens out a bit as a low pressure system
approached the upper Mississippi Valley region. Additional
sunshine will allow highs to rise into the lower to middle 80s
away from the Lake.
.LONG TERM...Monday Night Through Saturday
Issued at 318 AM CDT Sun Jul 22 2018
Pesky upper low that has been hanging around over the Ohio
Valley and eastern Great Lakes last few days will continue to
weaken and will eventually get absorbed by broader medium wave
trough forecast to settle over the western Great Lakes region by
late in the work week. As this transition occurs, broad upper-
level high pressure ridge that has dominated much of the southwest
CONUS will gradually get suppressed to the Desert Southwest by
next weekend. This will leave the forecast area generally under
the influence of a broad northern stream trough with occasional
weak shortwave disturbances propagating through the mean trough.
Temperatures will start out above normal during the first half of
the work week, then fall back to near or a little below normal
Main weather impacts will be associated with fairly potent cold
front that will approach the forecast area sometime late
Wednesday. Medium range guidance still struggling on timing and
intensity of primary shortwave to drop southeast into the western
Great Lakes with the GFS more progressive than the ECMWF. Will
continue to go with a blended solution at this time with best
guess frontal passage sometime around 06Z Thursday. Timing of
frontal passage during the overnight hours suggests threat for
severe weather would be minimal. Forecast soundings early Wednesday
evening over central Wisconsin suggest somewhat marginal MLCAPE
in 500 to perhaps 750 J/kg range and modest mid-level LRs of
around 6.0 deg c/km ahead of the front, while more favorable deep
layer shear lags behind the front. However, given the rather
potent shortwave trough and associated cold front, strong storms
are possible primarily west of the Fox Valley if models trend
toward a faster solution.
In the wake of the frontal passage, Thursday looks to be a cooler
and rather breezy day with CAA dominating the region. Signals in
the medium range guidance suggest additional shortwave energy to
rotate around primary upper low bringing additional chances for
showers or perhaps isolated thunder especially across the north on
Thursday afternoon. Daytime highs on Thursday will be quite a bit
cooler especially across the northwoods with highs in the lower
Upper-level trough will continue to influence the forecast area
into the weekend with small chances for showers associated with
any weak embedded shortwave disturbances. Confidence low on timing
of these transient disturbances so will just go with blended
solution of slight chance pops into the upcoming weekend. Max
temperatures during the latter half of the work week and into the
upcoming weekend will be a few degrees below normal for late July
mainly in the 70s.
.AVIATION...for 06Z TAF Issuance
Issued at 1046 PM CDT Sat Jul 21 2018
A large, slow-moving area of low pressure over the Ohio Valley
will continue to affect northeast Wisconsin with scattered
showers and low ceilings into Sunday morning. Scattered showers
over northeast and east central WI will become more numerous late
tonight into early Sunday as a short-wave trof rotates through
the area. MVFR ceilings are expected to lower to IFR overnight,
then persist until the showers move through Sunday morning.
Improving conditions are anticipated after the showers move out,
with VFR conditions returning to most locations by late morning
or early afternoon.
Gusty north to northeast winds will continue in eastern WI through
Sunday afternoon, then diminish by sunset.
.KOSH...Scattered showers will become more numerous toward
daybreak, then linger through much of Sunday morning, as an upper
level disturbance impacts the region. MVFR ceilings are expected
to lower to IFR again overnight, with IFR persisting until the
showers end late Sunday morning. Flight conditions should improve
to MVFR in the late morning, then VFR in the early afternoon.
North to northeast winds will continue to gust to 15 to 20 knots
through Sunday afternoon, then diminish by sunset.
Beach Hazards Statement through this afternoon for WIZ040-050.
Beach Hazards Statement until noon CDT today for WIZ022.