Special Weather Statement, NWS Milwaukee, WI

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1025 AM CDT THU JUL 28 2016

.AVIATION/18Z TAFS/...Post frontal stratus fairly widespread
across srn WI. This is largely of the MVFR category however there
are pockets of IFR and even some LIFR cigs close to Lake Michigan.
SREF prog suggests the IFR conditions becomes less likely tonight
however the NAM MOS lingers this a bit longer. Will try to show
some gradual improvement today though lake shore areas may take
longer to lift. Either way cloud cover not showing much sign of
eroding overall. Will have to keep an eye on convective
development esp across the far south where MLCAPE values have
risen to over 1500 j/kg. Influence of next shortwave will be
arriving later this afternoon and this evening so the trends in
HRRR appear reasonable in showing convection firing near best
instab/inverted trough and cloud/no cloud thermal discontinuity.

PC

&&

.MARINE...Onshore flow to persist however winds and waves
expected to hold below small craft criteria.

PC

&&

.PREV DISCUSSION... /Issued 337 AM CDT THU JUL 28 2016/

TODAY...Forecast Confidence Medium

Main area of precipitation over northern and central WI has been
firing in region of strong differential CVA ahead of short wave and
deep moisture convergence on eastern side of inverted surface trough
along the surface baroclinic zone and in the most-unstable CAPE
gradient, which has been slowly collapsing south. Isolated to
scattered showers/storms over southern WI with weaker DCVA.
Individual cells have been short-lived with little shear to support
updrafts in weak flow with 500 mb winds around 25 knots and speeds
in the single digits below 750 mb on area forecast soundings.

Showers and storms will taper off for a time as this initial wave
exits to the east this morning, then chances increase ahead of
another wave coming across from the eastern Dakotas and the inverted
surface trough sagging into sw WI and lingering through the
afternoon before slowly collapsing south this evening.

Will have higher chance to likely PoPs in the western CWA closer to
the low-level convergence along the surface trough axis, tapering to
slight chance in the far east. Clouds and precipitation will limit
high temperatures to the mid 70s.

TONIGHT...Forecast Confidence Medium

Scattered showers and storms will taper off from northwest to
southeast as the inverted trough sags into IL and drier air finally
streams in on northeast winds. However lingering low-level
convergence and a continuing parade of short wave energy will keep
at least chance PoPs in the forecast through the overnight.
Temperatures will cool into the lower 60s away from Lake Michigan,
with some upper 50s in the far northwest CWA.

FRIDAY AND SATURDAY...Forecast Confidence...Medium

A slow moving trough is expected to kick off more showers and storms
on Friday. East to northeast low level flow will keep deeper
moisture and better instability across the west/southwest portions
of the forecast area. May struggle to see any precip at all in the
east. Storm motion will be slow but will have a westerly component,
so did keep some low pops most places in the east.

It looks drier Friday night and Saturday, though the NAM and
Canadian are slower to scour out deeper moisture as they hang
onto the trough longer. The GFS and ECMWF would suggest mainly dry
conditions for this period. Decided to hang onto some pops per the
slower/wetter NAM and Canadian solutions.

Should see high temps a couple/few degrees below normal for Fri and
Sat, with highs in the mid/upper 70s.

SUNDAY AND MONDAY...Forecast Confidence...Medium

It should be dry Sunday and Monday with southern Wisconsin sitting
under the western portion of high pressure, while the next
approaching trough will still be well to the west. High temps are
expected to be a tad above normal in the low to mid 80s most
places.

TUESDAY AND WEDNESDAY...Forecast Confidence...Medium

Deeper moisture is progged to return Monday night into Tuesday.
Additionally, some warm advection aloft and a shortwave will
provide lift for showers and storms by later Monday night. The
best chance for storms is expected to be on Tuesday as the wave
moves through. Left some low pops in for Wednesday as models are
showing a weak wave may bring a few showers/storms.

Temps Tue/Wed will be largely dependent on the timing of
clouds/precip. Overall though, will likely see highs a few
degrees above normal.

AVIATION/12Z TAFS/...

Some spotty IFR stratus cigs developing in areas that saw scattered
showers/storms during the overnight. Will monitor trends but not
expected to last long at any one site nor become widespread.
Otherwise expect VFR conditions with MVFR cigs/vsbys with scattered
showers and thunderstorms expected to develop later this morning and
afternoon. Exception may be western CWA including KMSN where
upstream MVFR cigs will dip in with inverted  surface trough.

Looking for light easterly winds to turn northeast and become gusty
around 20 knots in the far east for a time today.

Drier air working in as trough drops south should raise cigs back up
to VFR tonight, though onshore winds may advect enough lake moisture
for cigs to linger near MVFR levels overnight.

MARINE...

Looking for northeast winds to rise to 10 to 15 knots with gusts to
20 knots this afternoon in the northern zones in tightening pressure
gradient behind inverted trough lingering over sw WI. Southern zones
not as gusty with a weaker gradient, and waves everywhere remain
just below small craft advisory criteria so will not issue a
headline at this time. Will add "Small craft should exercise
caution" phrase to the forecast for the northern zones.

&&

.MKX Watches/Warnings/Advisories...
WI...None.
LM...None.
&&

TODAY/TONIGHT AND AVIATION/MARINE...REM
Friday THROUGH Wednesday...DDV

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
419 AM CDT THU JUL 28 2016

WIZ046-047-051-052-056>060-062>072-290930-
MARQUETTE-GREEN LAKE-FOND DU LAC-SHEBOYGAN-SAUK-COLUMBIA-DODGE-
WASHINGTON-OZAUKEE-IOWA-DANE-JEFFERSON-WAUKESHA-MILWAUKEE-
LAFAYETTE-GREEN-ROCK-WALWORTH-RACINE-KENOSHA-
419 AM CDT THU JUL 28 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL
WISCONSIN...SOUTH CENTRAL WISCONSIN AND SOUTHEAST WISCONSIN.

.DAY ONE...TODAY AND TONIGHT

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY INTO THIS
EVENING IN THE WESTERN FORECAST AREA...WITH LESSER CHANCES FOR
STORMS IN THE EAST. NO SEVERE WEATHER IS EXPECTED.

THERE WILL BE A MODERATE SWIM RISK AT LAKE MICHIGAN BEACHES LATE
THIS AFTERNOON AND EVENING...DUE TO DANGEROUS CURRENTS PRODUCED
BY BUILDING WAVES ON PERSISTENT NORTHEAST WINDS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THERE WILL BE A MODERATE SWIM RISK AT LAKE MICHIGAN BEACHES FRIDAY
AS PERSISTENT NORTHEAST WINDS KEEP WAVES HIGH ENOUGH TO PRODUCE
DANGEROUS CURRENTS NEAR SHORELINE STRUCTURES AND THE MOUTHS OF
RIVERS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED THE REMAINDER OF THE WEEK.

LMZ643>646-290930-
SHEBOYGAN TO PORT WASHINGTON WI-
PORT WASHINGTON TO NORTH POINT LIGHT WI-
NORTH POINT LIGHT TO WIND POINT WI-
WIND POINT WI TO WINTHROP HARBOR IL-
419 AM CDT THU JUL 28 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF LAKE MICHIGAN.

.DAY ONE...TODAY AND TONIGHT

NORTHEAST WINDS AND WAVES WILL APPROACH...BUT REMAIN BELOW SMALL
CRAFT ADVISORY LEVELS THIS AFTERNOON INTO TONIGHT. SMALL BOATS
SHOULD EXERCISE CAUTION.

THERE IS A CHANCE FOR THUNDERSTORMS TODAY AND TONIGHT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE PERSISTENT NORTHEAST WINDS AND MODERATE WAVES WILL APPROACH
SMALL CRAFT ADVISORY LEVELS INTO FRIDAY MORNING.

REM
WWW.WEATHER.GOV/MKX

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1228 PM CDT THU JUL 28 2016

WIZ068-069-281830-
ROCK-GREEN-
1228 PM CDT THU JUL 28 2016

...STRONG THUNDERSTORMS PRODUCING TORRENTIAL RAINFALL WILL AFFECT
ROCK AND EASTERN GREEN COUNTIES...

AT 1226 PM CDT...STRONG THUNDERSTORMS WERE CLUSTERED OVER
ORFORDVILLE... OR NEAR BRODHEAD...MOVING NORTHEAST AT 10 MPH.

TORRENTIAL RAINFALL IS OCCURING WITH THESE STORMS...AND MAY CAUSE
LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS. WINDS IN EXCESS OF 30 MPH ARE ALSO POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
JANESVILLE...BELOIT...MILTON...EDGERTON...EVANSVILLE...BRODHEAD...
CLINTON...ORFORDVILLE...ALBANY...FOOTVILLE...LAKE KOSHKONONG...
FULTON...NEWARK...MAGNOLIA...TIFFANY...SHOPIERE...EMERALD GROVE...
INDIANFORD...AVALON AND COOKSVILLE.

FREQUENT CLOUD TO GROUND LIGHTNING IS ALSO OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 10 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

PERSONS IN CAMPGROUNDS SHOULD CONSIDER SEEKING STURDY SHELTER UNTIL
THIS STORM PASSES.

LAT...LON 4250 8940 4284 8945 4285 8896 4249 8878
TIME...MOT...LOC 1726Z 239DEG 7KT 4264 8925

SPM

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
129 PM CDT THU JUL 28 2016

WIZ063-064-069-070-281930-
JEFFERSON-ROCK-DANE-WALWORTH-
129 PM CDT THU JUL 28 2016

...AN AREA OF STRONG THUNDERSTORMS PRODUCING TORRENTIAL RAINFALL
WILL AFFECT SOUTHWESTERN JEFFERSON...WEST CENTRAL WALWORTH AND
NORTHEASTERN ROCK COUNTIES...

AT 128 PM CDT...STRONG THUNDERSTORMS WERE CLUSTERED NEAR
JANESVILLE... MOVING NORTHEAST AT 10 MPH.

WINDS IN EXCESS OF 30 MPH ARE POSSIBLE WITH THIS STORM. TORRENTIAL
RAINFALL IS ALSO EXPECTED...AND MAY PRODUCE MINOR FLOODING.

LOCATIONS IMPACTED INCLUDE...
JANESVILLE...WHITEWATER...FORT ATKINSON...MILTON...LAKE KOSHKONONG...
RICHMOND AND JOHNSTOWN CENTER.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY CAUSE
LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

LAT...LON 4263 8897 4278 8911 4295 8889 4273 8868
TIME...MOT...LOC 1828Z 234DEG 8KT 4275 8897

SPM