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000
FXUS63 KMKX 160225
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
925 PM CDT WED MAY 15 2013

.UPDATE...AREA OF MID-HIGH CLOUDS OVER MUCH OF IA SPREADING EAST
INTO FAR SOUTHERN WI LAST SEVERAL HOURS. CLOUDS ASSOCIATED WITH
WEAK MID LEVEL ISENTROPIC LIFT AND LOWER CONDENSATION PRESSURE
DEFICITS ON 310 THETA SURFACE. APPEARS SOUTHERN WI WL BE GRAZED BY
WEAK LIFT UNTIL AFTER MIDNIGHT. WL HOLD ONTO P/C WORDING IN SOUTH
WHILE NORTH REMAINS M/CLR. TWEAKED TEMPS DOWN A FEW DEGREES IN
NORTH AND EAST DUE TO MODERATE INVERSION SETTING UP AND DRY LOW
LEVELS.

&&

.AVIATION/06Z TAFS/...A VFR PERIOD WITH PASSING SCT-BKN HIGH
CLOUDS OVERNIGHT. WITH SHORT TERM GUIDANCE CONTINUING TO OVERDO
DAYTIME LOW LEVEL MOISTURE...NOT TOO EXCITED ABOUT ANY -SHRA
DEVELOPING ALONG LAKE BREEZE THU AFTN.

&&

.MARINE...SOUTH WINDS WILL TURN OFFSHORE AS A LAND BREEZE SETS UP
NEXT SEVERAL HOURS. LAKE BREEZE WILL REDEVELOP LATE THURSDAY
MORNING DUE TO TURN MORE NORTHEAST AS WEAK PRESSURE GRADIENT
INCREASES OVER SOUTHERN LAKE MI.

&&

.PREV DISCUSSION... /ISSUED 233 PM CDT WED MAY 15 2013/

SHORT TERM...

TONIGHT AND THURSDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH

A SHOWER OR TWO MAY LINGER IN THE EVENING...BUT OVERALL LOOKS DRY
TONIGHT AND THURSDAY MORNING. DRY CONDITIONS AT THE SURFACE WITH
MOSTLY CLEAR SKIES AND LIGHT WINDS TONIGHT SHOULD ALLOW TEMPS TO
FALL INTO THE LOW 50S MOST PLACES. THIS LINES UP NICELY WITH A
MODERATE SURFACE INVERSION AND 925 MB TEMPS AROUND 16C.

SHOULD BE AROUND 80 TOMORROW AWAY FROM LAKE MICHIGAN...AS 925 MB
TEMPS WILL BE A BIT WARMER...TOWARD 20C. SOME MODELS HAVE EASTERLY
PREVAILING WINDS RIGHT AWAY TOMORROW. EVEN IF WINDS ARE OFFSHORE AS
OTHER MODELS INDICATE...SHOULD SE A LAKE BREEZE DEVELOP QUICKLY AS
PREVAILING WINDS WILL BE LIGHT. TEMPS WILL THUS LIKELY HOLD STEADY
OR FALL THROUGH THE AFTERNOON NEAR THE LAKE.

MODELS ARE SHOWING A WEAK MID LEVEL FEATURE PUSHING THROUGH TOMORROW
AFTERNOON. THIS BRINGS INCREASED MID LEVEL MOISTURE INTO THE NORTH.
ADDITIONALLY...SOUNDINGS SHOW DECENT MID LEVEL LAPSE RATES...ALONG
WITH SOME LIFT IN THE MID AND LOW LEVELS. WONDERING IF SOME OF THE
LIFT IS DUE TO THE LAKE BREEZE...AS THE NAM AND WRF NMM FIRE THE
SHOWERS RIGHT ALONG THE BOUNDARY. IF SHOWERS DO FORM...GUESS A
RUMBLE OF THUNDER IS NOT OUT OF THE QUESTION GIVEN THE LAPS RATES
AND A BIT OF CAPE.

FRIDAY AND SATURDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.

THE UPPER JET EXTENDS ACROSS THE U.S. CANADIAN BORDER INTO THE
NORTHEAST U.S. WITH A JET MAX EXITING THE NORTHERN GREAT LAKES
FRIDAY. UPPER DIVERGENCE FRIDAY ACROSS MUCH OF WISCONSIN. THE
STRONGEST 700 MB UPWARD MOTION IS MORE ACROSS NORTHERN WISCONSIN.
AT 700 MB SATURATION OCCURS ACROSS A NW/SE BAND THAT LIFTS FROM
THE NORTHERN PORTIONS OF THE FORECAST AREA FRIDAY MORNING/EARLY
AFTERNOON INTO NORTHERN WISCONSIN FRIDAY NIGHT AS DRIER AIR PUSHES
INTO SOUTH CENTRAL WISCONSIN SATURDAY. WARM AIR ADVECTION OCCURS
IN THE 850/700 MB LAYER BUT THE MAIN 850 MB LOW LEVEL JET REMAINS
ACROSS THE PLAINS. SOME ELEVATED CONVECTION POSSIBLE FRIDAY AND
INTO THE SOUTHEAST ON SATURDAY...BUT ELEVATED CAPE IS LACKING IN THE
FORECAST SOUNDINGS.

ON SATURDAY A MID/UPPER RIDGE BUILDS INTO THE CENTRAL PLAINS TO
EASTERN SOUTH DAKOTA/SOUTHWEST MINNESOTA AHEAD OF A TROUGH OVER
THE WESTERN U.S. THE SURFACE WARM FRONT SHOULD BE TO THE
SOUTH AND SHOULD BE RATHER WEAK THIS FAR EAST OF THE MAIN LOW
DEVELOPING NEAR THE OKLAHOMA PAN HANDLE. THE SOUTHEAST WINDS WILL
ALLOW COOLING NEAR LAKE MICHIGAN...WHILE AREAS ESPECIALLY
SOUTHWEST OF MADISON WILL WARM.

LONG TERM...

SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE MEDIUM.

THE MID/UPPER RIDGE MOVES ACROSS WISCONSIN SATURDAY NIGHT AS THE
WESTERN TROUGH PUSHES INTO THE ROCKIES.

MODELS DIVERGE A LITTLE WITH THE 00Z ECMWF TAKING A LEAD SHORTWAVE
INTO THE UPPER MISSISSIPPI VALLEY QUICKER. THE GFS/GEM/DGEX ARE A
LITTLE SLOWER WITH THE TROUGH MOVEMENT WITH THE TROUGH/MID LEVEL
LOW STILL IN THE PLAINS.

SOUTHERN WISCONSIN WILL SEE INCREASING TEMPERATURES/LOW LEVEL
MOISTURE AND INSTABILITY WITH THE SOUTH FLOW DEVELOPING.
THUNDERSTORM CHANCES WILL INCREASE DURING THIS TIME FRAME. SOME
SEVERE STORMS WILL BE POSSIBLE MAINLY SUNDAY OR MONDAY. HOWEVER
GIVEN THE UNCERTAINTY IN LOW AND WARM SECTOR PLACEMENT...CONFIDENCE
IS NOT HIGH ON WHICH TIME FRAME THIS WILL OCCUR. APPEARS BETTER
CHANCES WILL BE MONDAY...WITH CWASP SEVERE PROBABILITY IN THE MID
70S ON THE 12Z ECMWF. HOWEVER LOW MAY BE OCCLUDING BY THAT TIME
AND BEST SEVERE CHANCES LIKELY TO BE WEST AND SOUTH.

THE CHANCE FOR SHOWERS WILL CONTINUE TUESDAY EVEN AS THE SURFACE
LOW MOVES EAST AS THE MID/UPPER TROUGH REMAINS ACROSS WISCONSIN...ALTHOUGH
TEMPERATURES WILL BE COOLER.

AVIATION/00Z TAFS/...

VFR CONDITIONS WILL PERSIST THROUGH THURSDAY. COULD SEE A FEW
SHOWERS MAINLY NORTH OF MADISON AND MILWAUKEE THROUGH LATE
AFTERNOON AND THEN AGAIN TOMORROW AFTERNOON...BUT OTHERWISE QUIET
WEATHER WILL CONTINUE.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&

$$
MBK