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000
FXUS63 KMKX 210902 AAA
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
402 AM CDT TUE MAY 21 2013

.TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM

A CLEARING TREND WILL CONTINUE THIS MORNING WHICH WILL AID DAYTIME
HEATING AND INSTABILITY FOR LATE THIS MORNING AND AFTERNOON. VARIOUS
MODEL SOUNDINGS VARY WITH EXPECTED CAPE VALUES FROM VERY LITTLE UP
TO 1000 J/KG. THIS HAS TO DO WITH DIFFERENCES IN MID LEVEL LAPSE
RATES AND DEWPOINTS. WILL COUNT ON MARGINAL CAPE PERHAPS UP TO 500
J/KG. TRIGGERS FOR CONVECTION TODAY ARE WEAK WITH A COUPLE WEAK
VORTICITY MAXIMUMS TO SWING NWD IN THE SLY FLOW ALOFT OF THE UPPER
LOW. A WEAK SFC TROUGH MAY ALSO BECOME PRESENT AS SLY WINDS TURN
MORE WLY. WILL GO WITH CHANCES OF TSTORMS FROM LATE AM THROUGH THE
AFTERNOON. LOW PROBABILITIES OF SEVERE WX WILL BE POSSIBLE GIVEN MDT
DEEP LAYER SHEAR AND MID LEVEL DRY AIR.

THE UPPER LOW WILL FINALLY BEGIN TO MOVE SEWD INTO WRN IA BY 12Z
WED. THE FORWARD TILT UPPER TROUGH WILL BECOME MORE NEGATIVE TILT
WITH SATURATION AND RAIN POSSIBLE IN FAR SE WI BY 12Z.

.WEDNESDAY AND WEDNESDAY NIGHT...FORECAST CONFIDENCE MEDIUM.

THE STACKED LOW PRESSURE SYSTEM FINALLY SLIDES INTO THE AREA ON
WEDNESDAY AND PASSES OVERHEAD WEDNESDAY NIGHT. THERE IS IMPRESSIVE
AND RATHER SUSTAINED Q-VECTOR CONVERGENCE THROUGH THE PERIOD WITH
DEEP MOISTURE AVAILABLE. THIS LOOKS LIKE OUR BEST CHANCE FOR A
WIDESPREAD RAINFALL. INSTABILITY IS MARGINAL SO WILL JUST CARRY A
CHANCE FOR STORMS. NO SEVERE WEATHER IS EXPECTED.

WINDS ALSO TURN ONSHORE ACROSS THE SOUTHEAST...SO AREAS CLOSE TO
THE LAKE WILL COOL OFF QUITE A BIT.

.THURSDAY AND THURSDAY NIGHT...FORECAST CONFIDENCE IS HIGH.

WILL LINGER A CHANCE FOR RAIN ACROSS THE SOUTHEAST THURSDAY
MORNING AS THE REMNANTS OF THE UPPER LOW PULL AWAY. THEN MUCH
COOLER AND DRIER WEATHER OVERSPREADS THE AREA ON INCREASING
NORTHEAST WINDS AS HIGH PRESSURE BUILDS IN. WE COULD SEE LOWS
THURSDAY NIGHT DIP INTO THE UPPER 30S IN MANY AREAS AS WINDS FALL
OFF WITH THE RIDGE AXIS MOVING OVERHEAD.

.FRIDAY AND FRIDAY NIGHT...

COOL AND DRY FOR FRIDAY WITH HIGH PRESSURE HOLDING STRONG.
AS THE RIDGE SLIDES OFF TO THE EAST FRIDAY NIGHT...THE RETURN FLOW
WARM AIR ADVECTION COULD BRING IN SOME LATE NIGHT THUNDERSTORMS.
THIS IS A PRETTY SMALL CHANCE AT THIS POINT.

.SATURDAY AND BEYOND...FORCAST CONFIDENCE IS LOW TO MEDIUM.

THE GFS AND THE ECMWF ARE IN DISAGREEMENT WITH THE PATTERN THIS
WEEKEND INTO EARLY NEXT WEEK. THE ECMWF MAINTAINS THE RIDGE OVER
OUR AREA AND THE GREAT LAKES THROUGH NEXT TUESDAY...RESULTING IN
DRY WEATHER. MEANWHILE THE GFS PUSHES A SFC BOUNDARY FARTHER
EAST...ACTING AS A FOCUS FOR SHOWERS AND STORMS THROUGH THE SAME
PERIOD. A BLEND WOULD KEEP ANY RISK FOR STORMS MAINLY OVER OUR FAR
WESTERN CWA...AND THOSE CHANCES LOOK SMALL.

&&

.AVIATION/12Z TAFS/...ISOLD IFR TO MVFR STRATUS AND VSBYS WILL
PRESENT OVER SRN WI EARLY THIS AM BUT PREVAILING CONDITIONS WILL BE
VFR. A WEAK WIND SHIFT LINE WILL GRADUALLY SHIFT WINDS FROM SLY TO
WLY TODAY. THERE IS A CHANCE OF TSTORMS MAINLY THIS AFTERNOON AS THE
WINDS SHIFT. SCT-BKN CUMULUS AROUND 5 KFT IS EXPECTED FROM LATE
MORNING THROUGH THE AFTERNOON. DRIER AIR WILL ARRIVE ON THE WLY
WINDS FOR TNT BUT LOW PRESSURE OVER IA WILL BRING GOOD CHANCES OF
RAIN TO FAR SRN WI INCLUDING KENW TOWARD SUNRISE WED AM. AREAS OF
LIGHT FOG COULD DEVELOP LATE TNT BEFORE THE CLOUDS AND RAIN CHANCES
MOVE BACK INTO THE AREA. WIDESPREAD RAIN WITH LOW CIGS AND VSBYS IS
THEN EXPECTED ON WED.


&&

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

$$

TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
WEDNESDAY THROUGH MONDAY...DAVIS