Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 300436
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1136 PM CDT TUE JUL 29 2014

.UPDATE...ISOLD TO SCT LIGHT SHOWERS WILL REMAIN POSSIBLE THROUGHOUT
THE NIGHT AS A SHORTWAVE TROUGH MOVES ACROSS THE REGION. ANOTHER
SHORTWAVE TROUGH WILL ROTATE AROUND THE LARGE CANADIAN POLAR
TROUGH FOR WED AFTERNOON WITH SRN WI ON THE WRN PERIPHERY OF IT. A
WEAK SFC TROUGH WILL BE RESIDE OVER THE REGION VIA THE UPPER
WAVE WITH WARM ADVECTION AHEAD OF IT. SO EXPECT ANOTHER ROUND OF
ISOLD TO SCT SHOWERS AND TSTORMS BUT PROBABLY LESSER COVERAGE THAN
WHAT OCCURRED MONDAY EVENING.


&&

.AVIATION/06Z TAFS/...SCT-BKN070-110 WILL PREVAIL THROUGH EARLY
WED AM ALONG WITH LINGERING ISOLD SHOWERS AS A SHORTWAVE TROUGH
PASSES THROUGH SRN WI. PATCHY FOG IS POSSIBLE DUE TO THE RAIN
COOLED AIR AND SOME BREAKS IN THE CLOUD COVER AT TIMES. OTHERWISE
CUMULUS CONGESTUS AROUND 5-6 KFT WILL DEVELOP ONCE AGAIN FOR WED
AFT AND EVENING WITH SCT SHOWERS AND TSTORMS DEVELOPING AS ANOTHER
UPPER WAVE PIVOTS AROUND THE LARGE POLAR TROUGH OVER SE CANADA.


&&

.PREV DISCUSSION... /ISSUED 331 PM CDT TUE JUL 29 2014/

TONIGHT...FORECAST CONFIDENCE MEDIUM.

A MID LEVEL SHORTWAVE ROTATING AROUND A STATIONARY CLOSED UPPER LOW
CENTERED OVER JAMES BAY IS OVER NORTHERN WI AT 3 PM THIS AFTERNOON
AND WILL CONTINUE TO MAKE ITS WAY SOUTHWARD THROUGH SOUTHERN WI
EARLY THIS EVENING. SHOWERS AND THUNDERSTORMS ARE DEVELOPING IN
RESPONSE TO THIS SHORTWAVE. LATEST RAP SOUNDINGS ARE NOW SHOWING
ONLY AROUND 200 J/KG OF CAPE TO WORK WITH...ALONG WITH WEAK SHEAR
AND MODERATE OMEGA AROUND 7 PM AT MADISON.

THE HRRR AND WRF-ARW MODELS AGREE THAT IS THE PEAK TIME OF
CONVECTION FOR OUR AREA. OTHERWISE...THERE WILL BE SOME SCATTERED
SHOWERS AND A FEW THUNDERSTORMS FROM NOW THROUGH LATE EVENING. THERE
COULD BE SOME SMALL HAIL OUT OF THE STRONGER CELLS AND WE WILL HAVE
TO WATCH FOR THE ONE OR TWO CELLS THAT MIGHT PRODUCE 1 INCH HAIL
THIS EVENING. GUSTY WINDS UP TO AROUND 35 MPH WILL BE POSSIBLE WITH
THESE SHOWERS AS WELL.

SHOWER ACTIVITY WILL DWINDLE AFTER MIDNIGHT IN THE WAKE OF THE
SHORTWAVE. LOWS ARE EXPECTED IN THE MID 50S. LIGHT WINDS AND
RAINFALL COULD LEAD TO SOME PATCHY LIGHT FOG TONIGHT.

WEDNESDAY...FORECAST CONFIDENCE MEDIUM.

THE UPPER LOW WILL REMAIN STATIONARY AND ANOTHER SHORTWAVE IS
EXPECTED TO DROP DOWN THROUGH THE STATE ONCE AGAIN IN THE AFTERNOON.
THIS ONE LOOKS A LITTLE DRIER WITH LESS INSTABILITY...SO I AM
EXPECTING ANY POP-UP SHOWERS TO BE MORE SCATTERED IN NATURE.
THUS...KEPT LOWER POPS INSTEAD OF RAISING THEM TO LIKELY.

MAX TEMPS SHOULD BE SIMILAR TO THOSE TODAY...IN THE UPPER 70S INLAND
FROM THE LAKE. THE OVERNIGHT SHORTWAVE WILL USHER IN MORE NORTHERLY
WINDS WEDNESDAY MORNING SO A LAKE BREEZE IS A SURE BET. INLAND AREAS
WILL KEEP THE NORTHWESTERLY WINDS THROUGH THE DAY.

SHORT TERM...WEDNESDAY NIGHT THROUGH FRIDAY NIGHT.

WED NIGHT...FORECAST CONFIDENCE HIGH

REGION CAUGHT BETWEEN SHORT WAVE RIDING 250 MB SPEED MAX THAT PASSES
TO THE NORTHEAST AND EAST AS IT ROTATES AROUND NEARLY-STATIONARY
UPPER LOW WOBBLING NEAR JAMES BAY ...AND SHEARED VORTICITY ON THE
WESTERN PERIPHERY OF MID-UPPER LEVEL CYCLONIC FLOW THROUGH THE
DAKOTAS AND IOWA. BEST FORCING AND INSTABILITY STAY CLOSE TO EASTERN
SHORT WAVE...BUT SOME OMEGA MOVES ACROSS NORTHEAST HALF OF CWA WED
EVENING. ALSO SOME BRIEF FORCING FOR ASCENT WITH WEAK UPPER LEVEL
DIVERGENCE WITH RIGHT ENTRANCE REGION OF THE JET MAX PASSING
THROUGH....THOUGH NAM IS EARLIER THAN GFS WITH THIS FEATURE.

WILL KEEP SLIGHT CHANCE POPS IN THE EARLY EVENING IN ALL BUT THE FAR
SW...AND LINGER BETWEEN 03Z AND 06Z IN THE NE HALF OF CWA.
DECOUPLING WITH DIMINISHING CLOUD COVER AFTER 06Z WILL ALLOW LOWS TO
COOL INTO THE MID-UPPER 50S.

THURSDAY AND THURSDAY NIGHT...FORECAST CONFIDENCE MEDIUM

YET ANOTHER SHORT WAVE DROPS THROUGH MAINLY THE NORTHEAST PORTION OF
THE STATE...BUT SOME WEAK 850 MB WARM AIR ADVECTION/CONVERGENCE
CROSSES SRN WI AHEAD OF THE WAVE THURSDAY AFTERNOON...UNDER COOLING
500 MB TEMPERATURES. RESULTING FORCING AND INSTABILITY DURING PEAK
HEATING BRINGS ANOTHER ROUND OF SHOWERS AND POSSIBLE
THUNDERSTORMS...WHICH WILL BE MORE LIKELY IF MORE MOIST SFC DEW
POINTS ON NAM PAN OUT WITH SFC BASED CAPE RISING TO NEAR 900 J/KG.

TIMING OF CLOUDS AND PCPN WILL AFFECT HIGH TEMPERATURES BUT GIVEN
925 MB TEMPS OF 20C TO 21C WEST AND 19C TO 20C EAST AND WESTERLY
GRADIENT WIND...EVEN THOUGH UNDER 10 KNOTS...STRONG ENOUGH TO HOLD
OFF LAKE BREEZE UNTIL MID-LATE AFTERNOON SHOULD SEE HIGHS CLIMB INTO
THE MID TO UPPER 70S EAST AND UPPER 70S TO LOWER 80S WEST.

WILL CARRY SOME CHANCE POPS INTO THE EVENING DUE TO MODEL
DIFFERENCES FOR POSITION OF WEAK SURFACE TROUGH WITH THE GFS AND
ECMWF LAYING IT OVER THE NRN CWA WITH SOME SFC CONVERGENCE THEN
SLOWLY WASH IT OUT OVERNIGHT.

FRIDAY AND FRIDAY NIGHT...FORECAST CONFIDENCE MEDIUM

MORE POTENT SHORT WAVE TROUGH MOVES THROUGH WI FRIDAY
AFTERNOON/EVENING...GIVING THE BEST CHANCE FOR WIDESPREAD SHOWERS
AND THUNDERSTORMS FOR THE WEEK. WHILE ALL OF SRN WISCONSIN SHOULD
SEE SOME PRECIPITATION...THE MODELS ARE FOCUSING THE STRONGEST
FORCING OVER THE EASTERN HALF OF THE CWA SO WILL KEEP LIKELY POPS
GOING THERE. SECONDARY SHORT WAVE...OF VARYING STRENGTH AMONG THE
MODELS...MOVES THROUGH AROUND/AFTER MIDNIGHT SO WILL GO WITH SLIGHT
CHANCE/CHANCE POPS FOR THE ENTIRE NIGHT.

LONG TERM...SATURDAY THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM

UPPER TROUGH AXIS SLOWLY PUSHES EAST FROM THE VICINITY OF LAKE
MICHIGAN...BUT SHORT WAVE ENERGY STILL AFFECTING SRN WI
SATURDAY...EITHER IN THE FORM OF A LINGERING BROAD CIRCULATION AS
DEPICTED ON THE GFS AND GEM...OR A TRAILING WEAKER SHORT WAVE IN THE
ECMWF. WILL KEEP SLIGHT CHANCE/CHANCE POPS ON SATURDAY WITH THE
HIGHER POPS OVER THE SOUTHEAST. STILL UNDER CYCLONIC FLOW INTO
SATURDAY EVENING BUT DRIER AIR MOVING IN WITH HIGH PRESSURE SHORT
WAVE RIDGING BUILDING IN FOR OVERNIGHT INTO SUNDAY. PRECIPITATION
CHANCES BEGIN TO RISE WITH TROUGH DIGGING INTO THE EASTERN GREAT
LAKES AS UPPER FLOW BUCKLES IN RESPONSE TO RE-DEVELOPING WESTERN
RIDGE.

AVIATION/00Z TAFS/...

A VFR PERIOD IS EXPECTED. LOOK FOR ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS OVER SOUTHERN WI FROM LATE AFTERNOON THROUGH MID TO
LATE EVENING. GUSTY WINDS UP TO 35 MPH AND BRIEFLY REDUCED VSBYS AND
CIGS WOULD ACCOMPANY ANY CONVECTION.  SMALL HAIL IS A POSSIBILITY AS
WELL.

MARINE...

THE SOUTHEAST WINDS IN THE NEARSHORE WILL VEER BACK TO THE WEST
TONIGHT. THE WINDS WILL ONCE AGAIN BECOME ONSHORE ON WEDNESDAY AS A
WEAK FRONT SAGS SOUTH ACROSS THE LAKE.

&&

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

$$

UPDATE...GEHRING
TONIGHT/WEDNESDAY AND AVIATION/MARINE...MRC
WEDNESDAY NIGHT THROUGH TUESDAY...REM


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