Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 240230 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
930 PM CDT WED APR 23 2014

.UPDATE...

BAND OF LIGHT RAIN...IN ZONE OF BEST ISENTROPIC LIFT ON 300K
SFC...CROSSING SRN WI IS PRODUCING RAINFALL AMOUNTS UNDER 0.10
INCH. LOOKS TO BE POCKETS OF GRAUPEL/MELTING GRAUPEL/PRODUCING THE
50 DBZ REFLECTIVITIES OVER SRN SAUK/NRN IOWA AND WRN MONROE
COUNTIES PER DUAL POL RADAR PRODUCTS.

WILL ADJUST WX/POP GRIDS FOR DISTINCT BACK EDGE TO THIS INITIAL
BAND. LATEST NAM AGREES WITH HI-RES/RAPID UPDATE MODELS IN
BRINGING THE NEXT ROUND OF RAIN SHOWERS INTO SRN WI OVERNIGHT WITH
CONVERGENCE ALONG 850 MB BAROCLINIC ZONE...CURRENTLY HIGHLIGHTED
BY WEST/EAST ORIENTED SHOWER BAND ACROSS CENTRAL IA INTO CENTRAL
IL ON AREA RADAR MOSAICS...WITH THE BEST CHANCES BETWEEN 09Z AND
12Z.

ALSO ADJUSTED POPS DOWNWARD IN THE FAR SOUTHEAST FOR THURSDAY
MORNING AS MODELS CONTINUE TO SHOW NRN EDGE OF A DRY PUNCH PUSHING
INTO THE FAR SOUTHEAST AROUND 15Z. PREVIOUS FORECAST ACCOUNTED FOR
THIS WITH REDUCED POPS OVER MOST OF THE REST OF THE CWA AND THOSE
WERE KEPT.

&&

.AVIATION/06Z TAFS/...

CONTINUE TO SEE VFR CIGS/VSBYS WITH THE VERY LIGHT RAIN WITH
INITAL BAND OF RAIN CROSSING SRN WI. WILL HOLD ONTO PREVAILING VFR
CONDITIONS WITH ONLY TEMPO MVFR VSBYS WITH THE BRIEFLY HEAVIER
RAIN THROUGH MID-OVERNIGHT HOURS THEN BRING IN MVFR CONDITIONS
WITH STEADIER SHOWERS. WILL LOOK TO RAISE BACK TO VFR...
ESPECIALLY AT EASTERN TAF SITES BY MID-MORNING THURSDAY UNTIL PCPN
WITH WITH LOW MOVES IN LATER IN THE AFTERNOON/EVENING THURSDAY.
LOOKING AT GUSTY SOUTHEAST WINDS DEVELOPING TURSDAY MORNING AHEAD
OF LOW...EASING THURSDAY EVENING WITH BAGGY GRADIENT WITH LOW.

&&

.MARINE...

NO CHANGES TO SMALL CRAFT ADVISORY THIS NSH ISSUANCE. GUSTY
SOUTHEAST WINDS LOOK TO DEVELOP BY MID-MORNING THURSDAY AND
CONTINUE UNTIL BAGGY GRADIENT AROUND SURFACE LOW REACHES THE
NEARSHORE WATERS AROUND MID-EVENING.

&&

.PREV DISCUSSION... /ISSUED 314 PM CDT WED APR 23 2014/

TONIGHT - CONFIDENCE...MEDIUM
MID LEVEL RIDGE AXIS EXTENDS ACROSS THE CWA. LOW LEVEL JET AXIS
SHIFTS EASTWARD TOWARDS WRN WI. GREATEST MOISTURE SURGE THERE.
ALL MODELS SHOW A WING OF ISENTROPIC ASCENT EXTENDING SEWD INTO
SRN WI FROM THE MAIN CONVECTIVE AREA FROM IA THROUGH SRN MN INTO
WC WI. SO WILL STICK WITH THE IDEA OF GRADUALLY EXPANDING POPS
ACRS SRN WI AS THE NIGHT GOES ON.

THURSDAY - CONFIDENCE...HIGH
MODELS AGREE ON TAKING SFC LOW PRES FROM IA INTO WC IL BY 00Z.
MEANWHILE 850 LOW LIFTS INTO NW WI. MOISTURE WILL BE TRANSPORTED
NORTHWARD WITH A NEARLY DUE SOUTH 40 KNOT 850 JET. PRIMARY SHORTWAVES
OF NOTE WILL BE MOVING INTO MN AND MO. HOWEVER DECENT JET
STRUCTURE IN PLACE WITH EVEN A HINT OF SOME COUPLING SO PLENTY OF
UPPER DIVERGENCE IN PLACE. SOME HINT OF A BREAK IN THE SE AFTER
OVERNIGHT WAA MOVES THROUGH WITH THE WESTERN CWA SEEING LESS OF A
BREAK AS NEXT FRONTAL INDUCED PRECIP MOVES IN QUICKLY ON THE HEELS
OF THE WAA. INSTABILITY LACKING. SOME ELEVATED CAPE NOTED ON THE
SOUNDINGS SO SOME RUMBLES OF THUNDER A POSSIBILITY.

THURSDAY EVENING AND OVERNIGHT...FORECAST CONFIDENCE...HIGH

SURFACE LOW PRESSURE IS PROGGED TO SLIDE BY JUST TO THE SOUTH
THURSDAY EVENING...WHILE A STRONG SHORTWAVE MOVES THROUGH THE
FORECAST AREA. PLENTY OF MOISTURE AND FRONTOGENETICAL FORCING...SO
WIDESPREAD RAINFALL IS EXPECTED. NOT REALLY SEEING MUCH
INSTABILITY...SO DROPPED THE THUNDER CHANCES.

FRIDAY AND SATURDAY...FORECAST CONFIDENCE...MEDIUM

LOW PRESSURE TO THE EAST FRIDAY WILL MOVE OUT...ALLOWING HIGH
PRESSURE TO SLIDE THROUGH FRIDAY NIGHT AND SATURDAY. LOOKS MAINLY
DRY FOR FRIDAY AND SATURDAY...THOUGH WITH BAROCLINIC ZONE SETUP
RIGHT IN THE AREA...COULD SEE A WEAK WAVE OR TWO BRING A LITTLE
PRECIP. MOST MODELS ARE PAINTING OUT A LITTLE QPF AT
TIMES...THOUGH NOT VERY GOOD TIMING AGREEMENT BETWEEN MODELS.

SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE...MEDIUM

BELOW NORMAL TEMPERATURES ALONG WITH OCCASIONAL RAIN CHANCES ARE
EXPECTED FOR THE FIRST HALF OF NEXT WEEK AS A LARGE UPPER LOW
SLOWLY MOVES THROUGH THE REGION. THE ECMWF REMAINS COLD ENOUGH TO
SUGGEST A FEW SNOW FLAKES WOULD EVEN BE POSSIBLE AT SOME
POINT...THOUGH CONFIDENCE IN SNOW TOO LOW TO PUT IN THE FORECAST
FOR NOW. ADDITIONALLY...BREEZY EAST WINDS ARE POSSIBLE AT
TIMES...MAKING THINGS EVEN MORE UNPLEASANT NEAR LAKE MICHIGAN.

AVIATION/00Z TAFS/...MID/HIGH CLOUDS INCREASING INTO WRN WI ASSOC
WITH WAA. STEADIER RAIN SHIFTING EWD FROM IA WITH DVLPG BAND ACRS NW
AND WC WI. SATURATION WILL BE A SLOW PROCESS INTO THIS EVENING. NO
IMPACT ON TAF SITES JUST A GRADUAL THICKENING OF A HIGH BASED VFR
BLANKET. TNGT/ERLY WED EXPECTING ISENTROPIC FORCING TO LEAD TO
BETTER SATURATION AND SHRA DEVELOPMENT. AS LOW PRESSURE APPROACHES
AND ACTUALLY MOVES SOUTH OF WI ON THURSDAY RAIN WILL BECOME MORE
WIDESPREAD WITH A GREATER LIKELIHOOD OF LOWERED CIGS/VSBYS.
DECENT PRESSURE GRADIENT SETS UP AHEAD OF TROUGH AXIS SO
EXPECTING SE WINDS TO RAMP UP FOR A TIME ON THURSDAY. ELEVATED
CAPE SUGGESTS ISOLATED/SLGT CHC THUNDER BUT NOT WIDESPREAD ENOUGH
FOR TAF INCLUSION.

MARINE...SOUTHEAST WINDS WILL BE INCREASING ON THURSDAY AHEAD OF
APPROACHING LOW PRESSURE. THIS WILL RESULT IN ONSHORE WINDS REACHING
ADVISORY CRITERIA. WAVES WILL BUILD IN RESPONSE TO THE HIGHER WINDS
AND REASONABLY GOOD FETCH.

&&

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

&&

$$

UPDATE...REM
TONIGHT/THURSDAY AND AVIATION/MARINE...COLLAR
THURSDAY NIGHT THROUGH WEDNESDAY...DDV



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