Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 210825
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
325 AM CDT MON APR 21 2014

.TODAY AND TONIGHT...FORECAST CONFIDENCE - MEDIUM.

FOCUS OF THIS FORECAST ON PRECIP THREAT TODAY.  WATER VAPOR PLUME OF
DEEPER MID-UPPER LEVEL MOISTURE HAS BEEN SPREADING INTO WISCONSIN
OVERNIGHT.  COLUMN PRECIPITABLE WATER VALUES WILL INCREASE TO
BETWEEN 1 AND 1.25 INCHES TODAY OVER SRN WI...AHEAD OF SHARPENING
MID-LEVEL TROUGH.  PWAT VALUES AT THIS RANGE FOR MID-APRIL ARE ABOUT
150-200 PERCENT OF NORMAL AND ABOVE THE 75TH PERCENTILE...
APPROACHING 2 STANDARD DEVIATIONS AT KGRB. INITIAL SURGE OF MOISTURE
HELPING TO TRIGGER SCATTERED -SHRA EARLY THIS MRNG OVER SRN WI WITH
MORE -SHRA INCREASING UPSTREAM OVER SOUTHEAST IA INTO WRN IL.  WL
KEEP SCT OR CHC POPS OVER MOST OF THE AREA THROUGH THE MID-MORNING
WITH LIKELY WORDING CONTINUING IN THE FAR WEST CLOSER TO BETTER
SYNOPTIC SCALE LIFT.

LATER THIS MORNING THROUGH THE AFTN...PHASING OF STRONGER MID-LEVEL
SHORT WAVE CURRENTLY IN VICINITY OF ND/MN BORDER INTO SRN CANADA
WITH WEAKER WAVE MOVING THROUGH SRN STREAM.  LAYER Q-VECTOR
CONVERGENCE INCREASES DURING THIS PERIOD BUT VALUES REMAIN LESS THAN
10 UNITS.  CONSIDERING THAT RIGHT ENTRANCE REGION OF UPPER JET
BRUSHES PORTIONS OF SRN WI LATER TODAY...RATHER SURPRISED Q-VECTOR
CONVERGENCE NOT A LITTLE STRONGER.  NEVER THE LESS...WITH DEEP
COLUMN MOISTURE IN PLACE...THINK SHOWERS AND SCT T WILL BECOME MORE
WIDESPREAD LATER THIS MRNG AND AFTN...SO INCREASED POPS TO
CATEGORICAL FOR SEVERAL HOURS.  MUCAPE INCREASES TO 500 TO 1000 J/KG
BUT BULK SHEAR REMAINS LOW.  NOT IMPOSSIBLE STRONGER T MAY PRODUCE
SMALL HAIL LATER TODAY.  ALSO...CORFIDI VECTORS REMAIN BETWEEN 5 TO
15 KNOTS DURING PEAK FORCING.  WARM CLOUD DEPTH REMAINS LESS THAN 7K
FEET...HOWEVER SOME LOCATIONS MAY RECEIVE SEVERAL BOUTS OF MODERATE
SHRA/T THAT MAY RESULT IN ONE HALF INCH TO ONE INCH OF RAINFALL
CAUSING LOCALIZED MINOR STREET FLOODING.

SHARPENING MID-LEVEL TROUGH EXITS AREA FAIRLY QUICKLY DURING THE
LATE AFTN AND EARLY EVENING AS DRIER...COLDER AIR SWEEPS IN.  WL
CARRY CHANCE POPS IN THE EARLY EVENING IN THE SOUTHEAST FOLLOWED BY
CLEARING SKIES.  BOUNDARY LAYER MIXING AND INFLUX OF DRIER AIR WILL
PREVENT FOG FORMATION.

.TUESDAY  CONFIDENCE...MEDIUM
UPPER TROUGH SHIFTS TO THE EAST WITH COLD ADVECTION CONTINUING.
LOW LEVEL COLD POOL LINGERS FOR THE DAY WITH 850 TEMPS A DEGREE OR
SO EITHER SIDE OF 0C. 925 TEMPS CONSIDERABLY COLDER AT ONLY 4-7C.
THIS WILL LIKELY YIELD HIGHS OF ONLY IN THE 50S AT INLAND AREAS
OUTSIDE OF THE LAKE INFLUENCE. MANY LAKESHORE LOCATIONS LIKELY TO
STAY IN THE 40S. LOW LEVEL RH PROGS AS WELL AS MOS SHOWING A MUCH
MORE GLANCING SHOT OF LOW LEVEL RH..MAINLY IN THE FAR EAST EARLY
ON. HOWEVER MOS AND BUFKIT ARE REALLY SHOWING A VERY PARCHED LOOK
SO LOOKS LIKE PLENTY OF SUNSHINE ON TAP.

.WEDNESDAY - CONFIDENCE...MEDIUM
HIGH PRESSURE RIDGE SHIFTS EAST WITH SE LOW LEVEL FLOW. MID LEVEL
RIDGE AXIS APPROACHES. LOW LEVEL WAA STARTS TO INCREASE. HOWEVER
850 JET CORE WELL WEST OF THE AREA THROUGH 18Z WITH DRY AIRMASS
STILL IN PLACE. BUFKIT SOUNDINGS REVEAL THE VAST AMOUNT OF LOW
LEVEL DRY AIR TO OVERCOME EAST OF THE LLJ AXIS. THE NAM IS MUCH
MORE PRONOUNCED IN THIS REGARD ESP IN THE ERN CWA...WITH THE GFS
STILL SHOWING DRY AIR THOUGH NOT AS DEEP. MODELS ARE IN SYNC WITH
KEEPING PRECIP LARGELY WEST OF CWA THROUGH 18Z...THEN SOME
DIVERGENCE OCCURS IN THE AFTERNOON AS THE GEM/NAM ARE SLUGGISH TO
EXPAND PRECIP INTO THE EAST...WHICH HAS MERIT GIVEN THE EXTENT OF
DRY AIR ON THE PROGGD SOUNDINGS...WHILE THE GFS/ECMWF BRING QPF
ALL THE WAY INTO ERN WI. WILL CONTINUE THE IDEA OF HAVING HIGHEST
POPS IN THE WEST...IN BETTER PROXIMITY TO LOW LEVEL JET AXIS.

.WEDNESDAY NIGHT - CONFIDENCE...MEDIUM
LLJ RAMPS UP AND TRANSLATES EAST INTO WI. GREATEST MOISTURE
INFLUX ASSOCIATED WITH LLJ AND OVERALL PROGGD POSITION OF LLJ
DYNAMICS FAVORS PORTIONS OF WRN AND NRN WI FOR THE BETTER/MORE
ORGANIZED CONVECTIVE POTENTIAL.

.THURSDAY AND THURSDAY NIGHT - CONFIDENCE...MEDIUM
POTENT SHORTWAVE APPROACHES FROM THE PLAINS WITH BEST DCVA FROM
LATE AFTN INTO THE ERLY EVE HOURS. SOME DISAGREEMENT ON POSITIONING
OF SFC LOW CENTER WITH THE GFS MORE OF BLEND OF THE SRN ECMWF AND
MORE NW GEM SOLUTIONS. CWASP VALUES ARE NOW JUST SHOWING 50S WITH
THE BETTER VALUES FURTHER SOUTH OF THE STATE WHICH IS ALSO
HIGHLIGHTED BY THE CIPS ANALOG GUIDANCE. BUFKIT SOUNDINGS ARE ALSO
NOT SHOWING A VAST AMOUNT OF CAPE TO WORK WITH. SO WHILE A DECENT
COVERAGE OF SHRA/TSRA EXPECTED...CONFIDENCE IN ORGANIZED SVR IS
RATHER LOW AT THE MOMENT.

.FRIDAY - CONFIDENCE...MEDIUM
COLD FRONT WILL HAVE SHIFTED OFF TO THE EAST BUT LOW PRESSURE
SLOW TO DEPART THE REGION. SO EXPECTING A SHOWERY REGIME TO
LINGER. SEVERAL SPOKES OF VORTICITY LIKELY TO BE ENHANCING LIFT IN
ADDITION TO THE SURFACE/850 TROUGH AXES COMING INTO PLAY.

.SATURDAY AND SUNDAY - CONFIDENCE...LOW
SUBSTANTIAL MODEL DIFFERENCES WITH THE GFS SHOWING A MORE
PROLONGED INFLUENCE OF THE ERN UPPER TROUGH. MEANWHILE THE ECMWF
IS MORE PROGRESSIVE WITH THAT FEATURE WITH A RENEWED TROUGH MORE
AGGRESSIVELY ADVANCING INTO THE PLAINS AND SETTING UP AN ACTIVE
BAROCLINIC ZONE EVENT FROM IOWA INTO ILLINOIS WITH SRN WI ON THE
NRN FRINGE OF PRECIP. ALLBLEND POPS TO HANDLE THIS FOR NOW WITH
RAIN CHANCES IN THE EXTREME SW CWA SATURDAY AND EXPANDING CWA
WIDE FOR SUNDAY.

&&

.AVIATION/12Z TAFS/...MAINLY VFR CONDITIONS EXPECTED FOR BULK OF
THIS FORECAST CYCLE.  HOWEVER LIKELY TO BE SEVERAL ROUNDS OF PRECIP
AFFECTING TAF SITES.  BEST CHANCE LATER THIS MRNG THROUGH MID-LATE
AFTN WHEN SCT T WILL BE IN THE VICINITY.  BRIEF HEAVY RAINFALL MAY
ACCOMPANY SHRA/T AS WELL WITH LIKELY MVFR CIGS/VSBYS.  PATCHY LIGHT
FOG MAY AFFECT KMSN EARLY THIS MRNG AS WELL.

&&

.MARINE...LIGHT AND VARIABLE WINDS WILL BECOME MORE SOUTH TO
SOUTHEAST THIS MORNING AND THEN VEER TO THE SOUTHWEST AHEAD OF
APPROACHING COLD FRONT THIS AFTERNOON.  COLD FRONT EXPECTED TO SWEEP
ACROSS SOUTHWEST LAKE MI LATE AFTN AND EARLY EVE CAUSING WINDS TO
CONTINUE VEERING TO THE NORTHWEST.  ENOUGH OF A SURGE OF COLD AIR
BEHIND FRONT TO CAUSE WIND GUSTS TO 25 KNOTS OVER THE NEARSHORE
WATERS AS PRESSURE GRADIENT TIGHTENS.  WL POST SMALL CRAFT ADVY FOR
TNGT THRU TUE MRNG.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 1 PM CDT TUESDAY
     FOR LMZ643>646.

&&

$$
TODAY/TONIGHT AND AVIATION/MARINE...MBK
TUESDAY THROUGH SUNDAY...COLLAR



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