Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 250845
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
345 AM CDT FRI APR 25 2014

.SHORT TERM...

TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.

THE NORTHERN TROUGH MOVES ACROSS THE LAKE SUPERIOR REGION TODAY WITH
THE SOUTHERN TROUGH EXITING THE UPPER OHIO VALLEY.  SOUTHERN
WISCONSIN IS IN THE RIGHT ENTRANCE REGION OF THE NORTHERN SPEED MAX
EARLY THIS MORNING WITH UPPER DIVERGENCE OVER SOUTHEAST WISCONSIN
UNTIL MID MORNING. BY THIS EVENING SOUTHERN WISCONSIN IS IN
NORTHWEST FLOW...WITH A 100 KNOT JET MAX MOVING ACROSS CENTRAL
ILLINOIS.

WEAK 700 MB COLD AIR ADVECTION THIS MORNING BEHIND THE MID LEVEL
TROUGH AXIS.  MODERATE 700 MB DOWNWARD MOTION THIS MORNING WITH
UPWARD MOTION THIS EVENING...ESPECIALLY NEAR THE ILLINOIS BORDER DUE
TO THE JET MAX.  STRONG DRYING THIS MORNING WITH SOME INCREASE IN
700 RH SOUTH THIS EVENING.  NAM HAS 700 MB SATURATION JUST SOUTH OF
THE ILLINOIS BORDER.  SOME ACCAS POTENTIAL WITH 70 JOULES/KG OF
ELEVATED CAPE LIFTING FROM 12 THSD FT. NAM IS THE MOST AGGRESSIVE ON
PRECIP WITH THE GFS AND ECMWF MUCH DRIER.

MAIN CONCERN FOR TODAY WILL BE WIND.  700 MB WINDS INCREASE TO 50
KNOTS THIS AFTERNOON.  LAPSE RATES OF 10 CELSIUS/KG IN LOW LEVELS
AND 8.6 AT 700 MB WILL ALLOW SOME OF THE STRONGER WINDS TO TRANSFER
DOWN.  WE MAY BE ABLE TO MIX DOWN WIND GUSTS TO 25 TO 30 MPH.

THE STEEP LAPSE RATES WILL ALSO RESULT IN RATHER MILD TEMPERATURES
TODAY WITH THE BRISK WEST WINDS.

SATURDAY THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM.

MID LEVEL RIDGING OVER THE CENTER OF THE COUNTRY WILL SHIFT INTO THE
GREAT LAKES REGION OVER THE WEEKEND. AN 850MB WARM FRONT WILL LIFT
INTO SOUTHERN WI WHILE THE 925MB AND SURFACE WARM FRONTS WILL HANG
UP OVER NORTHERN IL.

INITIALLY...SURFACE HIGH PRESSURE WILL BE IN PLACE OVER SOUTHERN WI.
THERE WILL BE A COOL NORTHEAST TO EASTERLY BREEZE ON SATURDAY WITH
HIGHS GENERALLY IN THE 50S...COOLER NEAR THE LAKE. WEATHER WILL BE
DRY THROUGH THE DAY...WITH INCREASING CLOUDS DURING THE AFTERNOON.

THEN THE SURFACE PRESSURE GRADIENT WILL STRENGTHEN AS A HIGHLY
AMPLIFIED UPPER TROUGH DIGS INTO THE CENTER OF THE COUNTRY SATURDAY
NIGHT THROUGH SUNDAY. THERE WILL BE A CHANCE FOR SHOWERS WITH THE
WARM AIR ADVECTION AND ISENTROPIC LIFT OVER SOUTHERN WI...ALTHOUGH
THE DEEP MOISTURE WILL NOT QUITE BE HERE YET. PLAN ON A BREEZY DAY
WITH COLD EAST WINDS AND TEMPERATURES IN THE UPPER 40S AND LOWER
50S.

.LONG TERM...

SUNDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM.

GET READY FOR A CLOUDY...COOL AND WET WEEK. EVEN THOUGH THE CALENDAR
WILL BE SWITCHING OVER TO MAY...IT WILL FEEL LIKE MARCH OR EARLY
APRIL. WINDS WILL GENERALLY BE OUT OF THE EAST FOR THE WEEK WHICH
MEANS COOLER NEAR THE LAKE WITH HIGHS IN THE UPPER 40S THERE AND
LOWER 50S INLAND.

A LARGE OCCLUDED LOW PRESSURE SYSTEM WILL STALL OVER THE CENTRAL
PLAINS ON MONDAY AND THEN MEANDER NORTHEAST OVER THE UPPER GREAT
LAKES BY THURSDAY AND FRIDAY. DEEP MOISTURE WILL ARRIVE INTO
SOUTHERN WI SUNDAY NIGHT AND HANG AROUND THROUGH MONDAY. A FEW
ELEVATED THUNDERSTORMS WILL BE POSSIBLE DURING THIS TIME DUE TO
STRONG OMEGA AND STEEPENING MID LEVEL LAPSE RATES. NOTHING SEVERE
EXPECTED.

SHOWERS WILL OCCUR OFF AND ON THE REST OF THE WEEK UNTIL THE SLOW-
MOVING LOW PRESSURE SYSTEM EXITS THE REGION. EVEN AFTER THAT ONE
MOVES OUT NEXT FRIDAY...MODELS ARE SHOWING ANOTHER UPPER TROUGH
SWINGING DOWN THROUGH WI FOR EARLY NEXT WEEKEND.

&&

.AVIATION/12Z TAFS/...

A BAND OF IFR CONDITIONS WILL ACCOMPANY THE TROUGH AXIS EARLY THIS
MORNING.  THEN STRONG DRYING WILL RESULT IN A RAPID TRANSITION TO
MVFR CIGS THEN VFR.   LAPSE RATES OF 10 CELSIUS/KG IN LOW LEVELS AND
8.6 AT 700 MB WILL ALLOW SOME OF THE STRONGER 850 TO 700 MB WINDS TO
TRANSFER DOWN THIS AFTERNOON.  WE MAY BE ABLE TO MIX DOWN WIND GUSTS
TO 25 TO 30 KNOTS.

MID LEVEL CLOUDS WILL INCREASE THIS EVENING...SOME ACCAS
POSSIBLE...ESPECIALLY NEAR THE ILLINOIS BORDER.

&&

.MARINE...

WEST WINDS PICK UP AGAIN LATE THIS MORNING BEHIND A SURFACE LOW NEAR
LAKE SUPERIOR.  SOME GUSTS TO 25 KNOTS EXPECTED...AND WILL LIKELY
REACH SMALL CRAFT ADVISORY CONDITIONS THIS AFTERNOON.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 6 PM CDT THIS
     EVENING FOR LMZ643>646.

&&

$$

TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
SATURDAY THROUGH THURSDAY...MRC



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