Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 272023
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
323 PM CDT Thu Apr 27 2017
Tonight...Forecast confidence is high.
The main focus for tonight is on how cold temperatures get and the
potential of a frost/freeze.
Before then, there are still some showers that have developed
across southern Wisconsin due to some weak low level instability
associated with cold low level air that has wrapped in on the
southern side of the low/mid level trough. As the system continues
to propagate northward this afternoon/evening, expect that drier
low level air will move in and help to end these showers.
Thanks to the persistent cloud cover and rain showers,
temperatures have stayed fairly cool in the low 40s today, so we
will not have to drop much to get into some potential frost/freeze
temperatures. Some potential limitations to the frost development
is with whether skies will clear with the skinny surface ridge
moving in and how strong the winds will be just off the surface.
Agricultural partners along the Wisconsin River in southwest
Wisconsin have said that a lot of fruit trees have started to
bud/leaf out in that region, so we have started to issue
frost/freeze headlines in this area. Other ares in southern
Wisconsin will be just as cold tonight, but reports are that the
trees/plants are not as far along there, thus no advisory.
Friday through Saturday...Forecast confidence is medium.
After a break in the rain tonight into early Friday, another round
of rain is expected to develop from the southwest as low level
moisture transport increases along a warm front that extends into
northern Illinois. Trends have been to back off on this rainfall
amounts, particularly tomorrow morning. The higher chances will
be further to the south where the moisture will be a bit deeper
along with the lift. While the QPF may be going down, forecast
soundings look like they would support drizzle with some low level
lift in a saturated layer. Have kept precipitation chances around
to account for this potential.
Saturday Night through Wednesday...Forecast confidence is medium.
After another break in the rain/drizzle as the low level moisture
transport shifts east, another system moves into the region for
Saturday night through Monday night. This extended period of
dreary conditions will consist of gusty winds out of the northeast
off of the lake with light to moderate rain throughout. The only
potential period for thunder appears to be on Sunday as the core
of the low moves into the region and brings some weak instability
in along with it.
Steady precipitation has ended for most areas, but some drizzle
may persist for the next few hours. MVFR ceilings will gradually
rise to around 3.5 kft tonight, but clearing is no longer
expected. Visibility should remain the VFR range through the TAF
period. The next chance for rain showers arrives late Friday
Wind will be diminishing into the evening as an area of low
pressure tracks to the north into southern Canada and a skinny
ridge of high pressure moves in from the southwest. As this ridge
drifts to the southwest Friday night, persistent northeast winds
will setup across southern Lake Michigan with winds increasing
into Sunday as the next area of low pressure moves toward the
region. This long fetch and persistent wind out of the northeast
should lead to some high waves and small craft advisory conditions
for much of the weekend on into early next week.
WI...Frost Advisory from 1 AM to 8 AM CDT Friday for WIZ056-057-062-
LM...Small Craft Advisory until 7 PM CDT this evening for LMZ643>646.
Tonight through Thursday/Marine...Halbach