Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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 222319
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
619 PM CDT Mon May 22 2017

.AVIATION(00Z TAFS)...Scattered convection has spread across
southern portion of CWA last several hours. Strongest storm
deposited dime size hail in/near Monroe around 23Z. That storm has
since weakened. Thinking convection formed due to earlier weak low
level convergence along instability axis. Some weakening of
convection last 30-45 minutes or so. Will need to continue chance
pops at least through the evening due to lingering instability and
nearby frontal boundary. With diminishing winds and high low level
rh, still expect areas of low clouds to develop later tonight into
Tuesday morning.

&&

.PREV DISCUSSION... (Issued 344 PM CDT Mon May 22 2017)

SHORT TERM...

Tonight and Tuesday...Forecast confidence medium.

With skies clearing off in the wake of this initial rain area
some buildup of MLCAPE has occurred to our west in Iowa however
low level convergence noted with wind shift and dew point
discontinuity into SW WI. So expecting further development of
shra/tsra into the evening hours esp in the western portion of the
cwa. Meso models have been pretty consistent with this evolution.
The approach of a 250 millibar jet core on eastern side of trough
will be enhancing upper divergence as well. Any tsra expected to
remain below severe levels with better air (instability wise) to
our west. 500 millibar low will continue to drop south into Iowa
through the end of Tuesday. The surface low will evolve well south
with an inverted trough extending into the area. The 500 millibar
low will keep disturbances pivoting in from the southwest as
overall trough axis remains to our west through the end of the
day. So POPS will be on the higher side this period though some
dry times as well.

Tuesday night through Thursday...Forecast confidence medium.

An upper low will drop south from IA to MO Tue nt with
cyclogenesis over the wrn portion of the Ohio River Valley. PVA
from the upper low and an inverted sfc trough extending into srn
WI will continue the light rain into Tue eve before becoming more
spotty. For Wed, the low pressure area will track to IN or Ohio
and then possibly Lower MI for Wed nt. Thus srn WI will be on the
wrn periphery of the low pressure area with small chances of
showers and continued cool temps. The large low pressure area will
finally shift far enough east on Thu for high pressure to build
into the region for the afternoon and night. Therefore, more
sunshine and warmer temps are expected. 0.30-0.60 inches of rain
is forecast from tnt-Wed.

LONG TERM...Friday through Monday...Forecast confidence medium.

Temps will return to near normal for this period although there is
uncertainty on how much cooling may occur with another large upper
trough that may drop into the Great Lakes. The large upper trough
will bring chances of showers and slight chances of tstorms for
the weekend.

AVIATION(18Z TAFS)...With slowly advancing trough axis expect
coverage of shra/isold tsra to be on the increase tonight. Wind
fields will weaken and with an uptick in low level moisture may
see some fog development tonight. Low pressure will continue to
develop to our south Tuesday with inverted trough axis extending
northward into srn WI. MOS guidance showing MVFR cigs evolving
tonight into Tuesday and some lower cigs possible especially with
onshore flow near the Lake. Unsettled pattern with the slowly
developing low pressure and only gradual eastward movement over
the next couple of days.

MARINE...Gusty southwest winds are expected into the early
evening. Gusts up to 25 knots are anticipated, so a Small Craft
Advisory is in effect from until 9 pm. Highest waves will be
toward the open waters.

Will have to watch any fog trends later tonight into Tuesday as
dew points will be up and overall flow is expected to be weaker.

Brisk northeast winds will probably reach small craft advisory
criteria on Wednesday.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory until 9 PM CDT this evening for LMZ643>646.

&&

$$

Aviation...MBK
Tonight/Tuesday and Marine...PC
Tuesday Night through Monday...MG


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