Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KMKX 240157
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
857 PM CDT MON MAR 23 2015

.UPDATE...
A DRIER EASTERLY FLOW HAS BROUGHT CLEARING SKIES TO MUCH OF THE
FORECAST AREA THIS EVENING. CLOUDS STILL LINGER ACROSS THE FAR
SOUTH...BUT THESE SHOULD BE MOVING OUT BY MIDNIGHT OR SO. TEMPS
WILL MIGHT BE A CHALLENGE GIVEN THE CLEAR SKIES AND NEW SNOW
COVER. THERE IS LIKELY ENOUGH OF A GRADIENT FLOW TO KEEP THE
RADIATIONAL CONTRIBUTION IN CHECK...BUT TEMPS WILL BE COLDEST
WHERE THERE IS DEEPER SNOW COVER. THIS IS ALREADY REFLECTED IN
THE CURRENT FCST. HIGHER CLOUDS ARE APPROACHING THE SOUTHWEST
ALREADY AS THE NEXT WEATHER SYSTEM EDGES CLOSER. HOWEVER...IT WILL
TAKE UNTIL LATER IN THE DAY ON TUESDAY FOR THE BIG PUSH OF
CLOUDS...SO WE SHOULD SEE SOME MORNING SUNSHINE...ESPECIALLY NORTH
AND EAST OF MADISON.

&&

.AVIATION/06Z TAFS/...
LOOK FOR VFR CONDITIONS THROUGH THE DAY ON TUESDAY WITH WINDS
FAIRLY STEADY OUT OF THE EAST TO SOUTHEAST. LOWER CLOUDS WILL
THEN RETURN TO THE SOUTHWEST BY LATE AFTERNOON TUESDAY AHEAD OF
THE NEXT LOW PRESSURE SYSTEM. THESE LOW CIGS ALONG WITH WIDESPREAD
PRECIPITATION WILL SPREAD ACROSS SOUTHERN WISCONSIN TUESDAY
EVENING. IT LOOKS LIKE MAINLY RAIN WITH A RUMBLE OR TWO OF THUNDER
POSSIBLE FOR A GOOD PORTION OF THE FORECAST AREA...WITH A MIX OF
RAIN...SNOW...SLEET...AND FREEZING RAIN IN THE NORTH AND
NORTHWEST.

&&

.PREV DISCUSSION... /ISSUED 335 PM CDT MON MAR 23 2015/

TONIGHT AND TUESDAY...FORECAST CONFIDENCE - HIGH.

LOWER LEVEL CLOUDS CONTINUE TO ERODE FROM NORTH TO SOUTH THIS
AFTERNOON...WHILE A CLOUD DECK A COUPLE THOUSAND FEET HIGHER MOVES
IN FROM THE WEST. SHOULD SEE AN OVERALL CLEARING TREND THIS EVENING
AND OVERNIGHT...WITH THE BEST CHANCE FOR LINGERING CLOUDS IN THE
SOUTHWEST. WITH DECREASING CLOUDS...LIGHT WINDS...AND A COLD/DRY
AIRMASS IN PLACE...LOOKS LIKE BELOW NORMAL TEMPS OVERNIGHT.

SHOULD BE A FAIR AMOUNT OF SUNSHINE TUESDAY....ESPECIALLY ACROSS THE
NORTHEAST HALF OF THE FORECAST AREA. HIGH TEMPS FOR TOMORROW ARE A
BIT TRICKY GIVEN THE NEW SNOWPACK...ONSHORE WINDS...AND INCREASING
CLOUDS FROM THE SOUTHWEST IN THE AFTERNOON. LEANED TOWARD THE COOLER
END OF MODELS IN THE EAST AND ACROSS THE SOUTH GIVEN THESE
CONDITIONS.

SOME LIGHT PRECIP SHOULD BE MOVING INTO THE SOUTHWEST BY EVENING
AHEAD OF APPROACHING PRESSURE. KEPT THE PRECIP AS RAIN FOR
NOW...THOUGH A LITTLE SLEET IS NOT OUT THE QUESTION

TUESDAY NIGHT...CONFIDENCE - MEDIUM.

SHORT TERM GUIDANCE HAS BEEN SHIFTING SLIGHTLY SOUTHWARD WITH
STRENGTHENING SFC LOW PRESSURE SYSTEM MOVING ACROSS THE REGION
TUESDAY NIGHT.  NAM...GFS AND CANADIAN CARRY DEEPENING SFC LOW
ACROSS SOUTHEAST WI AFTER 06Z/WED...WHILE 12Z ECMWF TAKES LOW MORE
OVER CHICAGO.  WL CONTINUE WITH MODEL CONCENSUS AND FOCUS ON STRONG
PUSH OF WARM...MOIST AIR ARRIVING DURING THE EVENING AS 850 AND 700H
CIRCULATIONS PASS BY JUST TO THE NORTHWEST OF CWA. PWAT VALUES
INCREASE QUICKLY TO AROUND 0.75 INCH WHICH IS AROUND THE 75TH
PERCENTILE FOR LATE MARCH.  DEEP MOISTURE TRANSPORT CARE OF 35 TO
45KT LOW LEVEL JET.  FORECAST SOUNDINGS CONTINUE TO SHOW ELEVATED
INSTABILITY OF SEVERAL HUNDRED JOULES SO WL CARRY THUNDER THREAT
ACROSS SRN CWA.

OF MORE CONCERN IS THAT TEMPS WL LIKELY COOL RAPIDLY AT THE ONSET OF
THE PRECIP DURING THE EVENING.  LOW LEVEL THERMAL PROFILES SHOW THE
WET BULB TEMP REMAINING SLIGHTLY BELOW FREEZING AS THE PRECIP MOVES
IN.  FARTHER ALOFT...PROFILES ARE SHOWING MORE OF A SLEET/RAIN
SCENARIO.  END RESULT MAY BE A PERIOD OF FREEZING RAIN OVER A PART
OF THE AREA...WITH THE BEST CHANCE NORTH OF A WEST BEND TO REEDSBURG
LINE. PAVEMENT TEMPS INITIALLY WILL BE ABOVE FREEZING FROM EARLIER
IN THE DAY...BUT WL HAVE A CHANCE TO COOL OFF TO NEAR OR BELOW
FREEZING AS WELL.

AS COOLER AIR WRAPS INTO LOW PRESSURE CIRCULATION LATER IN THE
NIGHT...ALSO EXPECT RAIN...SLEET AND FREEZING RAIN TO CHANGE OVER TO
SNOW FOR A TIME NORTH AND WEST OF MADISON.  CONTEMPLATED WINTER
STORM WATCH FROM FOND DU LAC WEST...BUT DUE TO UNCERTAINTY REGARDING
LOW LEVEL THERMAL PROFILE...HELD OFF ON WATCH AND ISSUED STATEMENT
HIGHLIGHTING THREAT FOR NOW.  RAPID RAINFALL OF THREE TENTHS TO ONE
HALF INCH SHOULD RESULT IN SOME PONDING OF WATER...ESPECIALLY IN THE
SOUTHWEST AND FAR SOUTH CWA WHERE LAST NIGHTS SNOW WILL LINGER.

WEDNESDAY THROUGH THURSDAY...CONFIDENCE - MEDIUM.

DRIER AIR ROTATING AROUND UPPER LOW WILL DIMINISH RAIN AND SNOW
SHOWER THREAT WEDNESDAY MORNING.  SECONDARY SHORT WAVE AND
REINFORCING PUSH OF COLD AIR WILL CONTINUE TO BRING SMALL CHANCE FOR
RAIN AND SNOW SHOWERS TO THE AREA WED NIGHT AND ESPECIALLY THURSDAY.

THURSDAY NIGHT THROUGH MONDAY...CONFIDENCE - MEDIUM.

UNSETTLED CONDITIONS TO CONTINUE THROUGH THE PERIOD...WITH
TEMPERATURES VARYING FROM NEAR TO WELL BELOW NORMAL FOR LATE MARCH.

A COLD PERIOD LOOKS LIKELY TO FINISH OFF THE WORK WEEK.  STRONG
NORTHWEST FLOW ON THE BACKSIDE OF AMPLIFYING LONG WAVE TROF OVER ERN
CONUS WILL USHER IN A REINFORCING SURGE OF COLD AIR FOR FRIDAY.
925H TEMPS COLDER THAN -10C ONLY WARM A FEW DEGREES DURING THE DAY.
DAYTIME TEMPS WILL STRUGGLE TO REACH THE MID 30S DESPITE PARTIAL
SUNSHINE.  IN ADDITION...WL NEED TO WATCH FOR POSSIBLY LAKE EFFECT
LIGHT SNOW SHOWERS THU NIGHT AS LOW LEVEL WINDS VEER TO THE
NORTHEAST FOR A TIME.

LONG WAVE TROF OVER ERN CONUS GETS NUDGED EWD OVER THE WEEKEND BY
APPROACHING STRONG CLIPPER LOW PRESSURE MOVING SOUTHEAST ACROSS SRN
CANADA.  WARM AIR ADVECTION WILL START IN EARNEST ACROSS SRN WI LATE
SAT AND SAT NGT AS LARGE HIGH PRESSURE SYSTEM SLIDES OFF TO THE
SOUTHEAST.  DESPITE WARM AIR MOVING IN ALOFT...SFC TEMPS WL BE
SLOWER TO RESPOND AND MAY HAVE TO DEAL WITH A SNOW OR MIXED PRECIP
EVENT LATE SAT NGT INTO EARLY SUN BEFORE ENDING OR TRANSITIONING TO
LIGHT RAIN.  COLDER TEMPS RETURN FOR THE FINAL DAY OF MARCH.

5DAY 500H MEANS BASED ON GFS SHOWING NEAR SEASONAL HEIGHTS AT 00Z/03
WITH WEAK TROFFING ACROSS CENTRAL CONUS INTO CANADA.  NCEP CLIMATE
FORECAST SYSTEM PLUMES FOR MKE SHOWS BELOW NORMAL TEMPS CONTINUING
THRU FIRST WEEK OF APRIL BEFORE TEMPS CLIMB TO MORE SEASONAL LEVELS.

AVIATION/00Z TAFS/...

LOWER CIGS CONTINUE TO HANG ON ACROSS THE SOUTHERN FORECAST
AREA...BUT SHOULD CONTINUE TO IMPROVE NORTH TO SOUTH INTO THE
EVENING AS DRIER AIR MOVES IN. SOME LOWER CLOUDS MAY PERSIST INTO
THE NIGHT ACROSS THE SOUTHWEST...WITH A RETURN TO VFR BY EARLY
MORNING.

LOWER CLOUDS WILL THEN RETURN TO THE SOUTHWEST BY LATE AFTERNOON
TUESDAY AHEAD OF THE NEXT LOW PRESSURE SYSTEM. THESE LOW CIGS ALONG
WITH WIDESPREAD PRECIPITATION WILL SPREAD ACROSS SOUTHERN WISCONSIN
TUESDAY EVENING. IT LOOKS LIKE MAINLY RAIN WITH A RUMBLE OR TWO OF
THUNDER POSSIBLE FOR A GOOD PORTION OF THE FORECAST AREA...WITH A
MIX OF RAIN...SNOW...SLEET...AND FREEZING RAIN IN THE NORTH AND
NORTHWEST.

MARINE...

A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED TUESDAY NIGHT AND
WEDNESDAY AS STRONG LOW PRESSURE MOVES THROUGH THE AREA.

&&

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

$$

UPDATE...DAVIS
TONIGHT/TUESDAY AND AVIATION/MARINE...DDV
TUESDAY NIGHT THROUGH MONDAY...MBK



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