Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
000
FXUS63 KMKX 230211 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
911 PM CDT TUE APR 22 2014

.UPDATE...

FORECAST TRENDING WELL WITH JUST A FEW MINOR ADJUSTMENTS TO
SKY/WINDS/TEMPERATURES. WILL KEEP AN EYE ON TEMPERATURES UNDER THE
CLEAR SKIES AND LIGHT WIND REGIME...BUT NO MAJOR CHANGES
EXPECTED.

 &&

.AVIATION/06Z TAFS/...
WINDS HAVE EASED WITH SURFACE RIDGE BUILDING OVER THE STATE.
LOOKING AT KEEPING VFR CONDITIONS THROUGH THE FORECAST AT ALL TAF
SITES...WITH ONLY TEMPORARY MVFR VSBYS AT WORST WITH WARM
ADVECTION SHOWERS LATE WEDNESDAY AFTERNOON/WEDNESDAY NIGHT. WILL
MAINTAIN PROB30 AT KMSN FROM 21Z UNTIL 00Z AND AT EASTERN SITES
FROM 00Z UNTIL 03Z WITH CONDENSATION PRESSURE DEFICITS ON
ISENTROPIC FORECASTS SHOWING IT WILL TAKE SOME TIME TO OVERCOME
DRY AIR BELOW 700 MB ON FORECAST SOUNDINGS. EVEN THE FASTER GFS
HOLDS THE BULK OF THE PRECIPITATION OVER S CENTRAL WI THROUGH
00Z...WITH THE LATEST NAM KEEPING PCPN WEST OF KMSN THROUGH 00Z
AND OUT OF EASTERN TAF SITES THROUGH 06Z WED.

&&

.PREV DISCUSSION... /ISSUED 247 PM CDT TUE APR 22 2014/

TONIGHT - CONFIDENCE...HIGH
LINGERING FEW/SCT CU ACROSS THE NORTHEAST CWA WILL CLEAR OUT THIS
EVENING. JUST A BIT OF CIRRUS UPSTREAM LIKELY TO CLIP THE SW CWA.
QUIET AND DRY HIGH PRESSURE MOVES IN. RIDGE AXIS OVER EASTERN WI
BY 12Z.

WEDNESDAY - CONFIDENCE...MEDIUM
LOW LEVEL NORTHERLY FLOW EARLY WITH SURFACE//850 RIDGE AXES SHIFTING
EAST. SOUTHERLY RETURN FLOW STARTS TO TAKE SHAPE DURING THE AFTERNOON.
MID LEVEL RIDGE AXIS DRAWS CLOSER DURING THE DAY THOUGH MAIN FOCUS
WILL BE ON POTENTIAL ISENTROPICALLY GENERATED BAND OF SHRA ACROSS WRN
INTO SC WI DURING THE AFTERNOON. 4KM SPC WRF/12Z NAM/12Z ECMWF SHOW
PRECIP ADVANCEMENT INTO SRN WI QUITE SLOW AS LINGERING DRY AIRMASS
DOMINATES. GFS LOOKS OVERDONE. ISENTROPIC PLOTS DO SHOW LOWERING OF
CONDENSATION PRESSURE DEFICITS DURING THE AFTERNOON...ESP ACRS SC WI
BUT STILL SHOWS A DECENT AMOUNT OF DRY AIR IN THE EAST...WITH CPD/S
STILL AOA 100MB. 925 TEMPS DO MODIFY TO 4-6C IN THE AFTERNOON THOUGH
GFS THERMAL PROFILE LOOKS TOO COOL. INLAND AREAS SHOULD REACH LOW/MID
50S...THOUGH ONSHORE FLOW WILL MEAN MORE 40S FOR THE FAR EAST.

WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE IS HIGH.

WARM ADVECTION WILL CONTINUE TO SWING THROUGH THE AREA DURING THE
EVENING WITH THE FOCUS AFTER MIDNIGHT SHIFTING TO THE WEST OF
MADISON WHERE THE LOW LEVEL JET WILL BE IMPINGING ON THE SFC AND
H8 WARM FRONTS AHEAD OF THE APPROACHING LOW PRESSURE SYSTEM/TROF.
THE SFC FRONT WILL REMAIN SOUTH OF WISCONSIN WED NGT...BUT THE H8
WARM FRONT SHOULD LIFT TO ABOUT A RACINE TO BARABOO LINE BY 12Z
THURSDAY. AN EASTERLY SFC WIND WILL ALLOW VERY CHILLY LAKE COOLED
AIR TO OVERSPREAD MUCH OF THE AREA...ENSURING THAT SFC WARM FRONT
WILL STAY SOUTH. WE SHOULD SEE TWO SEPARATE RAIN AREAS...THE FIRST
SWINGS THROUGH DURING THE EVENING WITH A LULL POSSIBLE...BEFORE IT
GETS GOING AGAIN WHEN THE NOSE OF THE LOW LEVEL JET PUSHES IN
LATER ON. THUNDER CHANCES LOOK QUITE LOW GIVEN THE LACK OF
INSTABILITY ON THE SOUNDINGS.

THE LOW PRESSURE TROF WILL PUSH ACROSS THE AREA ON THURSDAY. THE
ECMWF IS KEEPING A WEAK SURFACE LOW SOUTH OF THE BORDER AS IT
MOVES THROUGH...THE GFS TAKES THE LOW OVER CNTRL TO NCNTRL WI AND
THE NAM TRACKS ACROSS SOUTHERN WI. I STILL BELIEVE THE MORE
SOUTHERN SOLUTION IS THE WAY TO GO. THAT WOULD KEEP THE SFC WARM
FRONT SOUTH OF THE BORDER...KEEPING US IN THE COOLER SOUTHEAST
FLOW OFF THE LAKE...CLASSIC FOR THIS TIME OF YEAR. IT/S POSSIBLE
THE FAR SOUTHEAST COULD GET INTO A BRIEF WARM SECTOR IF THE LOW
MOVES ACROSS SOUTHEAST WISCONSIN. SO...EXPECT A COOL DAY ON
THURSDAY WITH RAIN AND A FEW THUNDERSTORMS THROUGH THE DAY. NO
SEVERE WEATHER IS EXPECTED. THURSDAY IS SEVERE WEATHER AWARENESS
DRILL DAY AND DON/T SEE ANY REASON WHY IT WON/T BE A GO.

FRIDAY INTO EARLY NEXT WEEK...FORECAST CONFIDENCE IS LOW.

RAIN AND A FEW THUNDERSTORMS WILL LIKELY CONTINUE INTO THURSDAY
EVENING...THEN EXIT QUICKLY WITH THE LATE NIGHT HOURS DRY. A
TRAILING COLD FRONT WILL TAKE IT/S TIME TO DROP SOUTH THROUGH THE
STATE...NOT UNTIL FRIDAY...WITH THE NAM/GFS/ECMWF OFFERING A HUGE
VARIETY OF OPTIONS ON TRENDS. IT SHOULD BE NOTED HERE THE ECMWF
HAS MADE A MASSIVE SHIFT IN HOW THINGS EVOLVE THIS WEEKEND INTO
NEXT WEEK...MORE ON THAT IN A MINUTE.

SO WE SHOULD BE MOSTLY DRY ON FRIDAY WITH HIGHS STILL ABLE TO
CLIMB INTO THE UPPER 50S TO MID 60S BEFORE THE FRONT DROPS
THROUGH. AS THE FRONT MOVES IN WE COULD SEE SOME LIGHT SHOWERS
DEVELOP FRI AFTERNOON...MAINLY NORTH AND WEST OF MADISON.

HIGH PRESSURE IS EXPECTED TO BRING DRY WEATHER ON SATURDAY.
BUT...THIS IS WHERE THE ECMWF AND THE GFS BEGIN TO BREAK. THE
MODELS HAD BEEN SHOWING A MASSIVE HUDSON BAY RIDGE THAT STRETCHED
SOUTH THROUGH THE GREAT LAKES AND WAS GOING TO KEEP US VERY COOL
AND MOSTLY DRY INTO EARLY NEXT WEEK. THE ECMWF HAS NOW WEAKENED
THE RIDGE CONSIDERABLY AND NOW SHOWS VERY STRONG LEE SFC
CYCLOGENESIS WITH THE LOW EVENTUALLY MOVING JUST SOUTH OF THE
AREA ON MONDAY. GIVEN THE WEAKER CANADIAN RIDGE...THE ECMWF NOW
DEPICTS A MUCH WETTER POTENTIAL SUNDAY THROUGH TUESDAY WITH MILDER
TEMPS. IT IS HARD TO TAKE SIDES AT THIS POINT AND THE MODEL BLEND
IS THE BEST WAY TO APPROACH THIS. STAY TUNED.

AVIATION/00Z TAFS/...NW WINDS WILL EASE TONIGHT AS SURFACE HIGH
SETTLES ACROSS ERN WI BY 12Z WED. PROXIMITY OF HIGH AND LINGERING
DRY AIR WILL DOMINATE INTO AT LEAST WEDNESDAY MORNING. SHRA CHANCES
WILL INCREASE ACRS SC WI DURG THE AFTN AS LEADING EDGE OF MOISTURE
ADVECTION ARRIVES ASSOCIATED WITH RENEWED WAA REGIME...THOUGH
SEVERAL MODELS SHOW PRECIP WILL STRUGGLE TO ADVANCE TOO FAR EAST
GIVEN LINGERING DRY AIR AND BETTER MOISTURE ADVECTION/LLJ AXIS
FURTHER WEST BACK INTO IA/MN.

&&

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

$$

UPDATE...REM
TONIGHT/WEDNESDAY AND AVIATION/MARINE...COLLAR
WEDNESDAY NIGHT THROUGH TUESDAY...DAVIS



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.