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000
FXUS63 KMKX 150205
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
905 PM CDT FRI JUN 14 2013

.UPDATE...

CONVECTION IS INCREASING ACROSS IOWA...SE MN AND NORTHWEST
WISCONSIN WITHIN AN IMPRESSIVE MOISTURE AXIS. THE STRONGEST
ACTIVITY IS ACROSS WESTERN IOWA. 850MB WARM AIR ADVECTION KICKS
IN ACROSS THE FORECAST AREA LATER TONIGHT AS THE LOW LEVEL JET
UPSTREAM BEGINS TO TILT FROM SOUTHERLY TO SOUTHWEST. THE THETA-E
ADVECTION IS IMPRESSIVE.

SOME OF THE CONVECTION UPSTREAM IS EXPECTED TO ROLL INTO THE
WESTERN FORECAST AREA AFTER ABOUT 1-3 AM. IT WILL BE BATTLING SOME
DRIER AIR IN THESE PARTS...PLUS THE LOW LEVEL JET WILL BE
WEAKENING. RIGHT NOW IT APPEARS THE STORMS WITH THE HEAVIEST
RAINFALL WILL BE LIMITED TO THE SOUTHWEST HALF OF THE FORECAST
AREA. SOME SMALL HAIL AND GUSTY WINDS ARE POSSIBLE AS SOUNDINGS
DO SHOW A REASONABLE AMOUNT OF ELEVATED CAPE AND EFFECTIVE SHEAR.

SHEAR VECTORS FOR RIGHT MOVING SUPERCELLS IS ALMOST DUE SOUTH. SO
WOULD EXPECT THE STRONGEST ACTIVITY ACROSS IOWA TO TAKE A TURN
TOWARD THE SOUTH WITH TIME.

THE HRRR MODEL TAKES MOST OF THE IOWA ACTIVITY SOUTH OF WISCONSIN
BY 12Z SAT MORNING. THE NEW NAM AT 00Z SHOWS THIS RIGHT TURNING
BEHAVIOR...BUT STILL CLIPS SOUTHWEST WISCONSIN.

&&

.AVIATION/06Z TAFS/...
THE BEST CHANCE FOR ANY THUNDERSTORMS OVERNIGHT WILL BE IN THE
KMSN AREA AFTER ABOUT 8-9Z SAT...AND THIS WOULD ONLY BE FOR A FEW
HOURS. KMKE/KENW/KUES WILL LIKELY REMAIN DRY THROUGH ABOUT 12Z AS
ANY STORMS PUSHING IN WILL BE BATTLING MUCH DRIER AIR OVER
SOUTHEAST WISCONSIN. ANOTHER ROUND OF STORMS IS POSSIBLE LATER
SATURDAY AFTERNOON AND INTO THE EVENING. GENERALLY EXPECT
CONDITIONS TO BE VFR...BUT COULD DROP TO MVFR FOR A TIME WITH ANY
WIDESPREAD STORMS SAT AFTERNOON AND EVENING.

&&

.PREV DISCUSSION... /ISSUED 329 PM CDT FRI JUN 14 2013/

TONIGHT AND SATURDAY...FORECAST CONFIDENCE IS LOW TO MEDIUM.

HAVE CONCERNS ABOUT 12Z NAM SOLUTION WHICH CARRIES MCS ACROSS SRN
WI AFT MIDNIGHT. NOT DOING A VERY GOOD JOB WITH WEAKENING
CONVECTION OVER SRN IA/NRN MO ATTM. ANY CONVECTIVELY INDUCED MCV
FROM THIS ACTIVITY SHOULD REMAIN SOUTHWEST OF SRN WI THIS EVENING.

MORE CONCERNED ABOUT ACTIVITY UPSTREAM OVER NW IA. MCV FROM THIS
ACTIVITY MAY AFFECT SOUTHWEST WI LATER TONIGHT/EARLY SAT. STILL
EXPECT STRONG PUSH OF LOW LEVEL THETA-E ADVECTION TO AFFECT SRN WI
OVERNIGHT AS PWAT VALUES DOUBLE TO AROUND 1.5 INCHES. SHORT TERM
GUIDANCE IN FAIR AGREEMENT ON PIVOTING WEAKENING LOW LEVEL JET
ACROSS SRN WI LATER TONIGHT...WHICH WL LIKELY CARRY WEAKENING
CONVECTION ACROSS TRI-STATE AREA AND PARTS OF SOUTHWEST WI.

EXPECT SCATTERED TO NUMEROUS CONVECTION TO REFIRE SATURDAY
AFTERNOON AS ENHANCED SYNOPTIC SCALE FORCING MOVES ACROSS SRN WI
IN RESPONSE TO RIGHT ENTRANCE REGION OF UPPER JET. BY THIS
TIME...DEWPTS WL LIKELY BE IN THE MIDDLE 60S RESULTING IN SFC
BASED CAPES OF 1000-2000 J/KG. SHEAR NOT THAT IMPRESSIVE BUT
SHOULD BE ENOUGH TO RESULT IN MULTI-CELLS AND ISOLD
SUPERCELLS...PROVIDED CLOUDS FROM MORNING MCS CLEAR DURING THE
LATE MRNG AND AFTN.

SHORT TERM...SATURDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE
IS MEDIUM.

SHORT TERM MODELS SHOW SOME DIFFERENCES WITH QPF PLACEMENT AND
SUBSEQUENT THUNDERSTORM CHANCES SATURDAY NIGHT. THE NAM IS NOW
KEEPING A MAJORITY OF THE QPF JUST SOUTH OF THE AREA SATURDAY
NIGHT. HOWEVER...THE GFS/ECMWF/CANADIAN MODELS ALL BRING A BLOB OF
QPF THROUGH PORTIONS OR MOST OF THE AREA SATURDAY EVENING...THEN
TAPER OFF LATER SATURDAY NIGHT.

THIS IS IN RESPONSE TO 850MB LOW LEVEL JET NOSE POINTING INTO THE
AREA AT 00Z SUNDAY PER ECMWF/CANADIAN...THOUGH NAM/GFS HAVE IT
POINTING FURTHER TO THE EAST. ALL MODELS SHOW RIGHT REAR QUADRANT
OF 250MB JET STREAK PUSHING THROUGH THE AREA DURING SATURDAY
EVENING...WITH THE 500MB VORTICITY MAXIMUM PASSING EAST THROUGH
THE AREA.

AREA FORECAST SOUNDINGS FROM NAM SHOWING MODEST MOISTURE IN THE
LOW LEVELS...WITH THE GFS SOUNDINGS MORE MOIST. ELEVATED CAPES OF
500 TO 900 J/KG WITH DECENT EFFECTIVE LAYER SHEAR ON GFS...LESS SO
ON ADJUSTED NAM SOUNDINGS. SEVERE STORMS WITH POSSIBLE LINEAR MCS
MAY CLIP FAR SOUTHWEST COUNTIES DURING THE EVENING...PER SPC DAY
2 OUTLOOK.

LEANED MORE TOWARD THE GFS/ECMWF/CANADIAN AND KEPT HIGH END CHANCE
TO LIKELY POPS NORTHWEST TO SOUTHEAST DURING THE
EVENING...TAPERING OFF LATER IN THE NIGHT...LINGERING IN THE FAR
SOUTH SUNDAY MORNING. THERE IS STILL SOME UNCERTAINTY HERE WITH
WHERE EXACTLY ANY CONVECTION WILL DEVELOP AND MOVE THROUGH...SO
KEEP UP WITH LATER FORECASTS.

NICE DAY EXPECTED SUNDAY...WITH DRIER AIR WORKING INTO THE AREA.
HIGHS SHOULD REACH INTO THE 80S ACROSS MOST OF THE AREA. LAKE
BREEZE LATE IN THE DAY WILL BRING COOLER TEMPERATURES THERE.

NEXT SYSTEM MOVES SOUTHEAST INTO THE REGION SUNDAY NIGHT INTO
MONDAY. SURFACE COLD FRONT SLIDES SOUTHEAST INTO THE AREA BY 00Z
TUESDAY...WITH A STRONG 500MB SHORTWAVE TROUGH. AREA FORECAST
SOUNDINGS SHOWING 500 TO 1000 J/KG MEAN LAYER CAPES WITH MODEST
DEEP LAYER SHEAR.

SLIGHT CHANCE POPS SUNDAY NIGHT IN THE WEST WERE ADDED...WITH
CHANCE POPS FOR MONDAY. MAY HAVE TO RAISE POPS IN LATER FORECASTS
GIVEN STRONG SHORTWAVE AND UNSTABLE AIRMASS OVER THE AREA. A
SEVERE RISK IS POSSIBLE MONDAY IF BETTER DEEP LAYER SHEAR
DEVELOPS.

LONG TERM...MONDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE IS
MEDIUM.

GFS/ECMWF IN DECENT AGREEMENT WITH FEATURES FOR MONDAY NIGHT
THROUGH THURSDAY ACROSS THE REGION. AFTER SMALL CHANCES FOR
LINGERING SHOWERS MONDAY EVENING...HIGH PRESSURE MOVES THROUGH AND
EAST OF THE REGION TUESDAY THROUGH THURSDAY. THIS SHOULD BRING A
STRETCH OF QUIET WEATHER TO THE AREA. TEMPERATURES SHOULD BE NEAR
SEASONAL NORMALS...WITH ONSHORE WINDS EACH DAY KEEPING LAKESHORE
AREAS SOMEWHAT COOLER.

THESE MODELS THEN DIFFER THURSDAY NIGHT INTO FRIDAY...WITH THE GFS
SHOWING A WARMER SOLUTION WITH WARM AIR ADVECTION
PRECIPITATION...AND THE ECMWF KEEPING THE REGION NORTHEAST OF THE
NEXT LOW PRESSURE SYSTEM IN THE CENTRAL HIGH PLAINS. USED
CONSENSUS BLEND FOR THIS PERIOD WITH TEMPERATURES AND POPS.

AVIATION/00Z TAFS/...

VFR CONDITIONS TO CONTINUE TONIGHT. INCREASING THREAT OF
CONVECTION AFFECTING KMSN AROUND AND AFTER 06Z THROUGH THE EARLY
MORNING. ISOLD CONVECTION MAY HOLD TOGETHER AND AFFECT ERN TAF
SITES EARLY SAT. CIGS MAY FLIRT WITH MVFR FOR A TIME SAT MRNG AS
WELL AS LOW LEVEL MOISTURE INCREASES. BETTER CHANCE FOR MORE
WIDESPREAD CONVECTION LATER SAT AFTN AND EVE.

MARINE...

SOME CONCERN REGARDING FOG POTENTIAL ON SATURDAY INTO SATURDAY
NIGHT IN LIGHTER LOW LEVEL WIND REGIME AND INCREASING SFC DEWPTS
INTO THE 60S. LATEST CLOSEUP SEA SURFACE MODIS IMAGERY SHOWS LAKE
TEMPERATURES REMAIN IN THE UPPER 40S TO MID 50S. OTHERWISE NO
PROLONGED PERIOD OF STRONGER WINDS ANTICIPATED THROUGH THE WEEKEND
BUT WL NEED TO WATCH FOR STRONG CONVECTION...ESPECIALLY IN SRN
ZONES SAT INTO SAT EVE.

&&

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

$$

UPDATE...DAVIS
TONIGHT/SATURDAY AND AVIATION/MARINE...MBK
SATURDAY NIGHT THROUGH FRIDAY...WOOD