Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 301510 AAA
Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
1010 AM CDT MON MAY 30 2016
There could be a stray shower in the far southwest late this
morning into early afternoon as a dying complex slides through.
Otherwise, skies should be mostly sunny today. Temperatures look
like they are on track to reach forecast highs this afternoon.
VFR conditions will prevail into the evening. There will be a
chance for showers and storms overnight and on Tuesday, which may
bring some lower visibilities at times.
West to northwest winds will shift to the southeast near Lake
Michigan late this morning into early afternoon as the lake
breeze pushes through.
Look for rather light south to southeast winds until a
cold front moves through later Wednesday morning. Winds will then
shift to a westerly flow through the end of the week. Winds and
waves should remain below small craft advisory levels through next
.PREV DISCUSSION... /Issued 525 AM CDT MON MAY 30 2016/
TODAY AND TONIGHT...Forecast Confidence Is Medium.
A vorticity maximum over central WI will move out over Lake MI
after 12z with differential AVA and subsidence the remainder of
the day. High pressure will prevail at the surface with low
relative humidity expected. Only few-sct cumulus and/or high
clouds will occur. 925 mb temps and the low humidity suggest high
temps will reach the lower 80s today with cooling near Lake MI via
the lake breeze.
For tonight, a shortwave trough will move into MN while low
pressure moves from the northern Great Plains toward nw MN. A weak
surface warm front will extend sewd from the low across southern
WI. Weak low to mid level warm advection and frontogenesis will
develop with MUCAPE values of several hundred mainly over south
central and southwest WI. Went with 20-40 PoPs with the highest
chances north of Madison. Low temps will range from the upper 50s
to lower 60s.
TUESDAY THROUGH WEDNESDAY NIGHT...Forecast Confidence Is Medium.
Models are in good agreement with showing southwest flow at 500 mb
Tuesday into Wednesday, before a shortwave trough slides eastward
through the region later Wednesday into Wednesday night. Moist
southerly flow at 850 mb continues across the region Tuesday
into Wednesday evening, as a surface cold front slowly moves
eastward through the region.
Area forecast soundings showing a general trend towards more low
level moisture and building mean layer CAPE as the front crosses
the area Wednesday into Wednesday evening. Continued trending
upward with pops Tuesday, with higher end pops Tuesday night into
Wednesday, before lowering Wednesday evening.
SPC has western portions of the area in Marginal Risk for severe
storms Tuesday/Tuesday night, with the east in Marginal Risk on
Wednesday/Wednesday evening. Deep layer shear is modest Tuesday,
but is stronger on Wednesday. Adjusted mean layer CAPE values on
NAM/GFS forecast soundings get to 500 to 700 J/kg or so Tuesday
and Wednesday, so isolated strong to severe storms cannot be ruled
out. However, think most convection will be below severe levels,
given the expected CAPE and shear values.
Warm highs in the lower to mid 80s are expected Tuesday inland,
with 70s near Lake Michigan with onshore winds. More clouds and
showers/storms Wednesday may hold down highs a bit compared to
THURSDAY THROUGH SUNDAY...Forecast Confidence Is Medium.
ECMWF/GFS show a period of quiet weather for Thursday into
Thursday night, as high pressure slides east across the region.
Models then diverge with trends for Friday into Saturday. They
both bring low pressure and a cold front through the region during
this period. However, the GFS has a more amplified 500 mb
shortwave trough passing through the area Friday night, with the
ECMWF missing the area to the north. Still, will go with consensus
pops for this period.
Models then have a 500 mb low develop in northeast Canada over the
weekend, which is stronger and further west on the GFS than the
ECMWF. This keeps small pops going into Sunday, with passing
embedded vorticity maxima. Temperatures remain in the 70s during
the Thursday into Sunday period, cooler near Lake Michigan with
lake breezes in the afternoon hours. Less humid conditions are
expected as well.
AVIATION/12Z TAFS/...Patchy ground fog will end around 12-13z.
Otherwise mostly sunny to partly cloudy skies are expected today
with high pressure prevailing. Few-sct cumulus around 5-6 kft are
expected along with some thin cirrus. Skies will become partly to
mostly cloudy at 6-10 kft as warmer air returns aloft. There are
chances of showers and slight chances of tstorms as well.
A ssely flow will develop later today and last through Wednesday.
The winds will remain relatively light and with low wave heights.
TODAY/TONIGHT AND AVIATION/MARINE...Wood
Tuesday THROUGH Sunday...Gehring