Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 061533
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1033 AM CDT SUN JUL 6 2014

.UPDATE...CONSIDERABLE DEBRIS CLOUDINESS UPSTREAM ALONG WITH LOW
LEVEL STRATUS FIELD WHICH HAS LEAD TO THE SHAKING OF CONFIDENCE
FOR HOW STORMS WILL EVOLVE LATER. THE PLAN IS IT IS TILL EARLY AND
THIS TIME OF YEAR THIS LOWER STRATUS SHOULD BURN OFF BURN OFF TO
ALLOW FOR THE BUILDUP OF CAPE. MORE SUN ACRS SE WI BUT INITIATION
POINT IS EXPECTED FURTHER WEST IN WC WI WHERE THE CLOUD COVER IS.
CONCERN ATTM IS THAT WE ARE NOT SEEING ANY DECREASE IN CLOUD COVER
EVOLVE. MID LEVEL JET STREAK STILL EXPECTED TO ENCROACH ON THE
AREA THIS AFTERNOON WITH TIGHTENING 500 MILLIBAR HEIGHT GRADIENT.
WITHIN THIS IS A WEAK SHORTWAVE THAT WILL AID IN VERTICAL MOTION.
UPPER JET FURTHER NORTH HOWEVER SOME DIFFLUENCE NOTED ACRS
CNTRL/SRN WI MODEL PROGGD DIVERGENCE IN RESPONSE TO THIS. SPC
SUGGESTS THIS CLOUDINESS MAY RESULT IN CONVECTION BEING TIED TO
THE FRONTAL ZONE BUT MODULATED BY HOW QUICK THESE CLOUDS AHEAD OF
IT CAN THIN. 00Z NMM/ARW ARE STILL RATHER ROBUST BUT DO NOT
BELIEVE THESE MODELS FROM LAST NIGHT HAVE A HANDLE ON THESE LOW
CLOUDS. MEANWHILE THE 13Z HRRR SHOWING SOME STRONGER STORMS BUT
NOT NEARLY AS WHAT THE OTHER 00Z MODELS WERE SHOWING. 12Z NAM
SHOWS QPF BULLSEYE ACRS ERN CWA BETWEEN 18-00Z...SO FRONT COULD
END UP INITIATING CONVECTION INTO A MORE UNSTABLE AIRMASS ACROSS
OUR CWA WHERE SOME SUN IS HEATING THINGS UP. SO LOTS OF
UNCERTAINTY AT THE MOMENT WITH THE THERMODYNAMICS BEING THE MAIN
QUESTION MARK. DYNAMICALLY/FORCING WISE...ALL SYSTEMS ARE STILL
GO.

PC

&&

.AVIATION/18Z TAFS/...PLENTY OF STRATUS ACRS NW 1/2 OF THE CWA
THOUGH EXPECTING SOME BURNOFF AS THE HEATING OF THE DAY INCREASES.
MAIN CHALLENGE CENTERS ON CONVECTIVE DEVELOPMENT WITH ALL OF THE
UPSTREAM CLOUDINESS HINDERING THE CAPE BUILDUP ATTM. HOWEVER STILL
EXPECT SOME THINNING AND SUBSEQUENT DESTABILIZATION TO MAINTAIN A
THREAT OF SOME STRONGER OR SEVERE STORMS LATER THIS AFTERNOON INTO
THE EVENING HOURS AS MID LEVEL STREAK/SHORTWAVE AND SURFACE COLD
FRONT APPROACH THE AREA. BUT THERE IS UNCERTAINTY ATTM. ANY STORMS
EXPECTED TO BE SOUTHEAST OF THE AREA BY 6Z WITH WEAK RIDGING
TAKING HOLD FOR MUCH OF MONDAY.

PC

&&

.PREV DISCUSSION... /ISSUED 348 AM CDT SUN JUL 6 2014/

TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.

AREA OF LOW STRATUS CLOUDS OVER MOST OF THE AREA SHOULD LINGER INTO
THE MORNING HOURS...BEFORE DAYTIME HEATING MIXES THIS LAYER OUT.

SYNOPTIC AND MESOSCALE MODELS SHOWING COLD FRONT MOVING EASTWARD
ACROSS THE AREA LATER THIS AFTERNOON THROUGH THE LATE EVENING HOURS.
A 500 MB VORTICITY MAXIMUM ACCOMPANIES THE FRONT. THE FRONT MOVES
INTO THE FAR WESTERN COUNTIES DURING PEAK HEATING. WARM AND HUMID
CONDITIONS ARE EXPECTED...WITH MID 80S F FOR HIGHS...AND DEW POINTS
AROUND 70 F. MEAN LAYER CAPES OF 2000 TO 2500 J/KG ARE EXPECTED. 0
TO 6 KM SHEAR VALUES OF 20 TO 30 KNOTS ARE EXPECTED AS WELL...WITH
PRECIPITABLE WATER VALUES OF AROUND 1.75 INCHES...2 STANDARD
DEVIATIONS ABOVE NORMAL.

AREA FORECAST SOUNDINGS DO SHOW A CAP TO BE OVERCOME...WHICH SHOULD
OCCUR BETWEEN 21Z SUNDAY AND 00Z MONDAY. CONVECTION IS LIKELY TO
OCCUR FROM WEST TO EAST WITH THE FRONT...BEGINNING AS DISCRETE CELLS
BEFORE BECOMING MORE LINEAR IN NATURE. SPC HAS AREA IN SLIGHT RISK
FOR SEVERE STORMS IN DAY 1 OUTLOOK LATER THIS AFTERNOON AND THIS
EVENING. LARGE HAIL AND DAMAGING WINDS ARE CERTAINLY POSSIBLE. 0 TO
1 KM SHEAR VALUES OF 10 TO 20 KNOTS DOES SUPPORT AN ISOLATED TORNADO
RISK AS WELL...WITH LOW LCLS EXPECTED. CONVECTION SHOULD DIMINISH BY
06Z MONDAY...ONCE UPWARD VERTICAL MOTION SHIFTS TO THE EAST.
TEMPERATURES SHOULD ONLY FALL INTO THE UPPER 60S TO AROUND 70 FOR
LOWS TONIGHT.

MONDAY...FORECAST CONFIDENCE...MEDIUM

ANOTHER ROUND OF STORMS EXPECTED MONDAY EVENING INTO THE NIGHT AS
A SHORTWAVE PUSHES THROUGH. INCREASED POPS GIVEN DECENT WARM
ADVECTION IN THE LOW AND MID LEVELS...ALONG WITH SOME UPPER LEVEL
DIVERGENCE. LOOKS LIKE A BIT LESS OF A SEVERE CHANCE THAN TODAY DUE
THE LATER TIMING AND LESS INSTABILITY...THOUGH 0-6 KM BULK SHEAR
OF 40-50 KNOTS WILL PROBABLY KEEP THINGS INTERESTING. SPC DOES
HAVE THE DAY 2 SLIGHT RISK INTO THE FAR WEST FORECAST AREA.

TEMPS MONDAY ARE EXPECTED TO BE ON THE WARM SIDE AGAIN...WITH 925
MB TEMPS GENERALLY IN THE 22-24C RANGE. SHOULD SEE A GOOD AMOUNT
OF SUN...SO WENT MID 80S MOST PLACES.

TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE...MEDIUM

A COUPLE OF WEAK WAVES MAY BRING A FEW SHOWERS AND STORMS TUESDAY
AND WEDNESDAY. THERE WILL BE MUCH LESS MOISTURE TO WORK WITH...AS
PRECIPITABLE WATER VALUES WILL BE AROUND AN INCH TUE...AND EVEN
LESS THAN THAT WED. FORCING IS ON THE WEAK SIDE TOO...SO KEPT
POPS ON THE LOW END.

THURSDAY THROUGH SATURDAY...FORECAST CONFIDENCE...MEDIUM

INCREASING WARM ADVECTION FROM THE SOUTHWEST MAY KICK OF A FEW
SHOWERS/STORMS LATER FRIDAY...BUT OTHERWISE IT LOOKS LIKE A DRY
END TO THE WORK WEEK. SHOWER/STORM CHANCES ARE THEN EXPECTED TO
INCREASE FRIDAY NIGHT INTO SATURDAY AS A SHORTWAVE MOVES THROUGH.
SHOULD SEE HIGH TEMPS WITHIN A COUPLE DEGREES OF NORMAL THU-SAT.

AVIATION/12Z TAFS/...

MVFR CEILINGS WITH LOW STRATUS CLOUDS SHOULD LINGER INTO THE MORNING
HOURS ACROSS MADISON...WITH THE EASTERN SITES IN AND OUT OF IT.
THESE CLOUDS SHOULD DISSIPATE BY AROUND 18Z SUNDAY. SOUTH SOUTHWEST
WINDS SHOULD BECOME GUSTY AT TIMES BY THE AFTERNOON...GUSTING TO
AROUND 22 KNOTS BY LATER IN THE AFTERNOON. DIURNAL CUMULUS SHOULD
DEVELOP AS WELL.

COLD FRONT WITH THUNDERSTORMS SHOULD AFFECT MADISON BETWEEN 22Z
SUNDAY AND 02Z MONDAY...AND THE EASTERN SITES BETWEEN 00Z AND 04Z
SUNDAY. STRONG GUSTY WINDS AND LARGE HAIL ARE POSSIBLE WITH ANY
SEVERE STORMS...ALONG WITH VISIBILITIES DOWN TO ALTERNATE MINIMUMS.

WINDS WEAKEN AND SHIFT TO THE WEST AFTER 06Z MONDAY...WITH CLOUDS
GRADUALLY THINNING OUT FROM WEST TO EAST.

MARINE...

SMALL CRAFT ADVISORY CONTINUES FROM 18Z SUNDAY TO 03Z MONDAY ACROSS
THE NEARSHORE WATERS. FREQUENT SOUTH SOUTHWEST WIND GUSTS TO 22 TO
25 KNOTS SHOULD OCCUR DURING THIS TIME...WITH GOOD MIXING OF THE LOW
LEVEL WINDS. WAVES SHOULD BUILD TO 3 TO 4 FEET NEAR SHEBOYGAN...WITH
2 TO 4 FOOT WAVES TO THE SOUTH. WINDS AND WAVES WILL SUBSIDE TONIGHT
AFTER COLD FRONT MOVES INTO THE AREA.

BEACHES...

A MODERATE SWIM RISK IS EXPECTED FOR SHEBOYGAN AND OZAUKEE COUNTY
BEACHES ALONG LAKE MICHIGAN LATER THIS MORNING INTO EARLY THIS
EVENING. THE WINDS WILL BE SOUTH TO SOUTH SOUTHWEST AND
GUSTY...GENERATING WAVES OF UP TO 3 TO 4 FEET. THIS WILL POSE SOME
RISK TO SWIMMERS IN THESE AREAS. WILL NOT ISSUE A BEACH HAZARDS
STATEMENT AT THIS TIME.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM CDT THIS
     EVENING FOR LMZ643>646.

&&

$$
TODAY/TONIGHT AND AVIATION/MARINE...WOOD
MONDAY THROUGH SATURDAY...DDV


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