Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KMKX 181457
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
957 AM CDT Fri May 18 2018

.UPDATE...Few light showers may have grazed southwest Lafayette
county in past hour or so, but have since dissipated. These may
have been due to some weak 750mb frontogenesis rotating around
southern MO upper low. As this upper low gets nudged northward,
still looking like some showers will spread into parts of southern
WI late this afternoon and evening. Otherwise, a pleasant morning
will give way to gradually thickening mid-high clouds this
afternoon. Temperatures look in good shape for now.

&&

.MARINE...Will let Small Craft Advisory expire shortly at 15Z.
Wind gusts and waves are expected to remain sub threshold for the
rest of today and tonight. Lake surface temps in the upper 30s to
lower 40s. Shallow inversion over the colder lake will prevent
stronger winds from mixing down to lake surface.

&&

.PREV DISCUSSION... (Issued 631 AM CDT Fri May 18 2018)

UPDATE...The forecast is on track for today and tonight.

AVIATION(12Z TAFS)...LLWS will be possible this morning through
14Z on an ely 40-45 kt low level jet. Otherwise VFR conditions
today into the early evening. Cigs of 1-3 kft and good chances of
rain will then occur for the late evening with Cigs falling below
1 kft after midnight along with areas of Vsbys of 2-5SM. The low
Cigs and Vsbys will improve by Sat afternoon.

PREV DISCUSSION... (Issued 319 AM CDT Fri May 18 2018)

DISCUSSION...

Today and Tonight...Forecast Confidence is high.

Enely winds will continue today making for cool temps near Lake MI
but continued 70s well inland. The slow moving upper trough over
the Middle MS River Valley will track to the IL and IN border by
12z Sat. The increasing PVA and moisture transport will bring
likely rain showers to ern WI tonight with lesser chances over
south central WI.

Saturday...Forecast confidence is medium.

The models are really struggling with the split flow over the
center of the U.S. becoming confluent over the Great Lakes. Energy
ejecting out of the Central Plains into the Great Lakes is
differing just enough to produce a variety of solutions for the
weekend. So, confidence is challenged. This will continue into
next week.

We`ll see rain tonight that will dissipate on Saturday and we
could end up with mostly dry conditions by afternoon. But, a
northeast flow will keep it much cooler near Lake Michigan. Clouds
look abundant as well.

Sunday and Monday...A mid level short wave and associated surface
low pressure system will push into the area, producing scattered
showers and a few thunderstorms. The clouds, showers and east to
northeast wind should keep temps mainly in the 60s. The
GFS/NAM/ECMWF are handling this low pressure system very
differently. The EC is the most northern, wetter and progressive
solution, while the GFS is more south, weaker and results in a
drier period. The GFS is showing rather wild swings from run to
run and the EC appears far more stable. Will keep the precip
probabilities in the chance category given the uncertainties, but at
some point those will likely increase as confidence is gained.

Tuesday and Tuesday night...Forecast confidence is medium.

The ECMWF has us under a drier northerly flow within high pressure
in the wake of the stronger low pressure system that exits to the
east. The GFS, on the other hand, brings much more moisture north
into Wisconsin with a weak trough moving through. This is a huge
departure from its dry forecast on the previous run. There is too
much uncertainty in this pattern to know which solution will pan
out. Thus, we`ll see small chances of precip continue into this
period.

Wednesday and Thursday...Forecast confidence is medium.

It looks like high pressure all around with the models, so this
should be a dry period with temperatures back to warmer levels.

AVIATION(09Z TAFS)...LLWS will be possible this morning through
15Z on an ely 40-45 kt low level jet. Otherwise VFR conditions
today into the early evening. Cigs of 1-3 kft and good chances of
rain will then occur for the late evening with Cigs falling below
1 kft after midnight along with areas of Vsbys of 2-5SM. The low
Cigs and Vsbys will improve by Sat afternoon.

MARINE...A Small Craft Advisory remains in effect until 10 AM CDT
from Port Washington south to Winthrop Harbor IL. 3 to 5 foot
waves will linger before falling to 2 to 4 feet by late morning.
Nely winds 10-15 kts are forecast.

WATCHES/WARNINGS/ADVISORIES... WI...None. LM...Small Craft
Advisory until 10 AM CDT this morning for LMZ644>646.

$$

Today/Tonight and Aviation/Marine...Gehring

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory until 10 AM CDT this morning for LMZ644>646.

&&

$$

Update...MBK
Today/Tonight and Aviation/Marine...MBK
Saturday THROUGH
Thursday...Gehring



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.