Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 060205 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
905 PM CDT SUN JUL 5 2015

.UPDATE...

NO BIG CHANGES TO FORECAST EXCEPT TO ADD SOME PATCHY FOG INTO THE
LATE OVERNIGHT HOURS. LATEST RUC SOUNDINGS SHOW LOW-LEVEL WINDS
DECOUPLING SOMEWHAT...AND EVEN THOUGH SOME TURBULENT MIXING JUST
ABOVE MODEST NEAR-SURFACE INVERSION WILL PREVENT ANY WIDESPREAD
FOG...COULD NOT RULE OUT SOME PATCHY FOG. ANY FOG SHOULD DISSIPATE
WITHIN AN HOUR OR TWO OF SUNRISE. LOOKING AT TREND OF LATEST HRRR
AND PREVIOUS NAM RUNS OF BRINGING A LEAD BAND OF DYING CONVECTION
FROM STORMS...CURRENTLY OVER MINNESOTA BACK TO SE SOUTH
DAKOTA...ACROSS SOUTHERN WISCONSIN IN THE MID TO LATE MORNING
HOURS. NEXT SHIFT WILL HAVE TO ASSESS THE FULL 00Z DATA SET TO SEE
IF THERE WILL BE A NEED TO BRING SOME POPS INTO THE AREA IN THE
MORNING.

&&

.AVIATION/06Z TAFS/...

EXCEPT FOR LOW CHANCE FOR SOME PATCHY FOG IN THE LAST FEW
HOURS BEFORE SUNRISE...STILL LOOKING AT TREND OF LATEST HRRR AND
PREVIOUS NAM RUNS OF BRINGING A LEAD BAND OF DYING CONVECTION
ACROSS SOUTHERN WISCONSIN IN THE MID TO LATE MORNING HOURS. WILL
AWAIT A LOOK AT COMPLETE 00Z DATA SET TO SEE IF THERE IS A NEED TO
ACCOUNT FOR THIS INITIAL BAND IN THE 06Z TAFS. 12Z GUIDANCE WAS
SHOWING POTENTIAL FOR SUB-1000 FT CIGS ALONG AND BEHIND THE FRONT.
WILL AWAIT FULL DATA SET TO SEE IF THIS TREND CONTINUES.

&&

.MARINE...

LATEST SHORT-TERM GUIDANCE IS SUPPORTING CURRENT FORECAST TREND
OF SOUTHERLY WINDS INCREASING THROUGH THE MORNING...AND THUS WILL
LEAVE TIMING OF SMALL CRAFT ADVISORY AS IS. PRIOR TO WINDS PICKING
UP...COULD SEE SOME HAZE/FOG THAT REDUCES VSBYS UNDER 5
MILES...AND POSSIBLY SOME PATCHES OF DENSE FOG.

&&

.BEACHES...

THERE IS A POTENTIAL FOR A HIGH SWIM RISK FOR THE BEACHES OF
SHEBOYGAN AND OZAUKEE COUNTIES FROM LATE TOMORROW MORNING INTO
MONDAY EVENING. STRENGTHENING SOUTH WINDS IN THE TIGHTENING
PRESSURE GRADIENT AHEAD OF AN APPROACHING COLD FRONT WILL PRODUCE
3 TO 5 FOOT WAVES AND LIFE-THREATENING CURRENTS...ESPECIALLY ON
SOUTH-FACING BEACHES AND NEAR PIERS AND BREAKWALLS. NEXT SHIFT
WILL HAVE TO ASSESS LATEST GUIDANCE TO SEE IF A BEACH HAZARD
STATEMENT WILL BE NEEDED.

&&

.PREV DISCUSSION... /ISSUED 330 PM CDT SUN JUL 5 2015/

TONIGHT - CONFIDENCE...MEDIUM.

WEAK MID LEVEL SOUTHWEST FLOW WITH BROAD LOW LEVEL ANTICYCLONIC
REGIME IN PLACE. WARM AND INCREASINGLY MOIST SOUTHERLY FLOW SETTING
UP AHEAD OF THE SYSTEM IN THE PLAINS. LLJ AND SHORTWAVE ACTIVITY
WILL KEEP THE STORMS WELL TO OUR WEST THIS PERIOD. DIURNALLY DRIVEN
CU WILL DISSIPATE THIS EVENING WITH POTENTIAL FOR CONVECTIVE DEBRIS
ARRIVING AS THE NIGHT WEARS ON.

MONDAY - CONFIDENCE...MEDIUM

A WARM AND HUMID DAY IS SETTING UP AS SSW WINDS BECOME GUSTY. 925
TEMPS OFF THE NAM REACH LEVELS THAT WOULD SUPPORT A FEW LOWER 90S IN
PARTS OF THE EAST. OTHER MODELS NOT QUITE AS AGGRESSIVE AND SOME
CONCERN ABOUT LINGERING DEBRIS CLOUDS FROM CONVECTION TO OUR WEST.
SO WON/T GO QUITE THAT HIGH BUT WILL HAVE PLENTY OF MID/UPPER 80S
GOING. WESTERLY 500 MILLIBAR FLOW INCREASES WITH SHORTWAVE PROGGD
INTO WRN WI DURG THE AFTN. INSTABILITY LOOKS TO BE PLENTIFUL. 12Z
NAM SOUNDINGS SUPPORT CAPES TO NEAR 3000 J/KG IN MSN DURG THE AFTN
WHILE THE 12Z GFS HAS INCREASED FROM THE 6Z RUN...WITH CAPES AROUND
1000 J/KG. IF SUN IS AMPLE THINK WE CAN HIT AT LEAST SOMEWHERE
CLOSER TO THE MIDDLE GROUND. SO MID LEVEL FORCING WILL BE ARRIVING
IN PRIME TIME. CWASP NUMBERS HIGHEST ON THE NAM...IN THE LOW
70S...WHILE OTHER MODELS LOWER. 0-6KM SHEAR IS OK BUT NOT AT THE
SWEET SPOT OF AOA 40 KTS. HOWEVER 0-1KM SHEAR IS 20-25 KNOTS WHICH
IS FAVORABLE. SOME CONCERN OVER THE PROGGD VERY LOW MID LEVEL LAPSE
RATES AND THE ORIENTATION OF 850 JET CORE SHOWING MORE OF AN
ENTRANCE REGION PLACEMENT AT 00Z. MAIN UPPER JET IS PROGGD TO OUR
NORTH BUT SOME INCREASE IN UPPER DIVERGENCE NOTED DURING THE
AFTERNOON. 12Z ECMWF DEVELOPS A STRONGER LOW INTO CNTRL WI BY 00Z
WITH OTHER SOLUTIONS A BIT WEAKER BUT BEST LOW LEVEL FRONTAL
CONVERGENCE JUST WEST OF CWA BUT DRAWING CLOSER DURING PEAK HEATING.
WILL HAVE HIGHEST POPS ALIGNED SIMILARLY TO WHAT WE HAVE GOING WITH
BIGGEST POPS IN THE NW AND SMALLEST CHANCES IN THE SOUTHEAST. 4KM
SPC WRF DOES SUGGEST A SCENARIO SIMILAR TO THE 12Z NAM WITH SOME
DEVELOPMENT POSSIBLE DURING THE AFTERNOON AHEAD OF THE AFTERNOON.
SPC HAS UPGRADED TO SLIGHT RISK FOR MUCH OF CWA AND THIS SEEMS
REASONABLE ESP GIVEN THE POTENTIAL INSTABILITY AND BETTER FORCING
PARAMETERS ARRIVING AT PEAK TIME OF DAY INTO ESP SC WI. GIVEN PROGGD
POOR MID LEVEL LAPSE RATES WOULD NOT EXPECT MUCH IN THE HAIL
DEPARTMENT...WHICH CIPS ANALOGS SUPPORT...WITH WIND EVENT MORE
LIKELY GIVEN FAVORABLE LOWER LEVEL LAPSE RATES AND PRETTY DECENT
DOWNDRAFT CAPES PROGGD.

MONDAY NIGHT THROUGH WEDNESDAY...FORECAST CONFIDENCE - HIGH
TRENDING TOWARD MEDIUM.

WILL CONTINUE TO CARRY A 3 TO 5 HOUR PERIOD OF CATEGORICAL POPS
ACROSS CWA THRU 06Z TUES AS STRONG COLD FRONT MOVES ACROSS SRN WI.
SHORT TERM GUIDANCE IN BETTER AGREEMENT ON CARRYING AXIS OF HIGHER
LAYER Q-VECTOR CONVERGENCE ACROSS SRN WI ASSOCIATED WITH UPSTREAM
SHORT WAVE TROF CURRENTLY MOVING ACROSS WY/CO AREA.  PLENTY OF
MOISTURE IN PLACE AS PWAT VALUES INCREASE TO AROUND 2 INCHES...WHICH
IS ABOUT 2 STANDARD DEVIATIONS FOR EARLY JULY. MODERATE
FRONTOGENETICAL FORCING IN THE LOW LEVELS AS EXPECTED WITH FRONT
WILL EXTEND UP TO ABOUT 10K FEET INCREASING THE LIKLIHOOD FOR MORE
WIDESPREAD CONVECTION.  SFC DEWPT POOLING LIKELY TO INCREASE INTO
THE LOW 70S AHEAD OF THE FRONT ON MONDAY.  HOWEVER STILL SOME
UNCERTAINTY REGARDING THERMAL PROFILE ALOFT AND AMOUNT OF ELEVATED
INSTABILITY AS FRONT MOVES THROUGH.  BULK SHEAR WILL BE
MODEATE...SUPPORTING MULTICELLS AND PERHAPS A FEW SUPERCELLS.   WITH
SFC FRONT MOVING THRU DURING BETTER TIME OF THE DAY...SPC UPGRADE TO
SLIGHT RISK IN WRN CWA UNDERSTANDABLE.

STORMS END LATER MONDAY NIGHT WITH PASSAGE OF COLD FRONT.
DRIER...LESS HUMID AIR SPREADS RAPIDLY ACROSS SRN WI LATER MON NIGHT
AND CONTINUES ON TUE AS HIGH PRESSURE BUILDS INTO THE UPPER MIDWEST.

WEAK LOW PRESSURE MOVING ALONG THE FRONT SITUATED SOUTH OF WI ON
WEDNESDAY MAY BRUSH THE AREA WITH SOME MID-HIGH CLOUDS...BUT AT THIS
TIME...EXPECTING THE DRIER AIR AND HIGH PRESSURE TO KEEP PRECIP
SOUTH OF THE STATELINE.

WEDNESDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE - MEDIUM
TRENDING LOW.

MEDIUM RANGE GUIDANCE HAVING ISSUES LATE IN THE WEEK AS HIGHER
AMPLITUDE PATTERN TRANSITIONS TO MORE PROGRESSIVE...ZONAL SCENARIO.
WHILE DEEP...CLOSED LOW OVER NORTHERN HUDSON BAY SHIFTS SLIGHTLY
NORTHWARD...SECOND WEAKER CLOSED LOW OVER SOUTHWEST CONUS IS
EXPECTED TO FURTHER WEAKEN AND GET NUDGED NORTHEAST AHEAD OF
APPROACHING ERN PACIFIC TROF.  GUIDANCE HAVING ISSUES WITH TIMING
AND STRENGTH OF AMOUNT OF RIDGING AFFECTING NORTHERN PLAINS INTO THE
UPPER MIDWEST LATE IN THE WEEK...AND ITS AFFECT ON FRONTAL BOUNDARY
DRAPED ACROSS THE CENTRAL US EAST INTO THE OH VALLEY.  GFS STILL
BULLISH ON STRONGER...COMPACT SHORT WAVE AFFECTING SRN WI THU NGT
WHILE GEM MUCH SLOWER AND TAKES THIS WAVE WELL NORTH OF THE AREA ON
FRIDAY.  ECMWF DOES CARRY WEAK MID-LEVEL WAVE ACROSS NRN IL THU NGT.
FOR NOW WL CONT TO CARRY SMALL POPS FOR THESE PERIODS.

FOR THE WEEKEND...DIFFERENCES CONTINUE AS ECMWF CONTINUES
DRIER...MORE ZONAL PATTERN ACROSS THE UPPER MIDWEST WHILE GFS
TRENDING TO MORE SOUTHWEST STEERING FLOW.  THIS WOULD RESULT IN MORE
UNSETTLED CONDITIONS FOR THE REGION AS FRONTAL BOUNDARY SHIFTS
NORTHWARD.  WPC BLENDED SOLUTION FAVORING DRIER ECMWF SOLUTION BUT
DOES GIVE SOME WEIGHT TO GFS AND GEM FOR NEXT WEEKEND.  HENCE CAN
NOT AVOID KEEPING LOW POPS GOING FOR THE LATER PERIODS.  TEMPS WILL
WARM TO MORE SEASONAL NORMALS BY THE WEEKEND.

AVIATION/00Z TAFS/...

QUIET AND VFR FOR MUCH OF THIS PERIOD. SOUTHERLY FLOW GRADUALLY
PICKS UP AHEAD OF FRONTAL BOUNDARY APPROACHING FROM THE PLAINS. MAY
SEE PATCHY FOG DEVELOP ONCE AGAIN TONIGHT BUT NOT EXPECTING ANYTHING
TOO WIDESPREAD OR DENSE AS SOUTH WINDS AT THE SURFACE AND ALOFT A
BIT STRONGER. STILL LOOKS LIKE THE MAIN LINE OF STORMS ARRIVES LATER
MONDAY AFTERNOON IN SC WI AND ARRIVING EARLY EVENING IN THE SE.
MODELS ARE HINTING AT SOME PRE-FRONTAL DEVELOPMENT LATE MRNG/ERLY
AFTN BUT THE MAIN EVENT LOOKS TO BE FROM MID AFTERNOON IN THE SC
THROUGH EARLY EVENING INTO THE SE.

MARINE...HAVE ISSUED A SMALL CRAFT ADVISORY FOR MONDAY AFTERNOON
AND EVENING DUE TO A TIGHTENING PRESSURE GRADIENT AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM NOON TO 10 PM CDT MONDAY FOR
     LMZ643>646.

&&

$$

UPDATE...REM
TONIGHT/MONDAY AND AVIATION/MARINE...COLLAR
MONDAY NIGHT THROUGH SUNDAY...MBK



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