Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 302032
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
332 PM CDT SAT APR 30 2016

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 332 PM CDT SAT APR 30 2016

LIGHT RAIN ACROSS SOUTHERN MN THIS AFTERNOON CONTINUES TO CREEP
SLOWLY NORTHWARD...ASSOCIATED WITH AN UPPER LEVEL LOW PRESSURE
SYSTEM OVER NEBRASKA AND KANSAS. THE FA IS BEING INFLUENCED BY A
COUPLED JET STRUCTURE ALOFT...WITH THE RIGHT ENTRANCE REGION OF A
120+ KNOT JET OVER THE WESTERN GREAT LAKES AND THE LEFT EXIT
REGION OF A 100+ KNOT JET IN EASTERN IA. AMPLE DIFFERENTIAL
DIVERGENCE STRETCHES FROM SOUTHERN MN THROUGH WEST CENTRAL WI
THROUGH THE EVENING. IN ADDITION...UPGLIDE AND ADIABATIC OMEGA ARE
SEEN ON THE NAM/GFS 295K THETA SURFACE RIGHT UP TO THE TWIN CITIES
THIS EVENING BEFORE THE FLOW BECOMES PARALLEL. THEREFORE...EXPECT
THE RAIN TO REACH INTO THE SOUTH METRO FOR A FEW HOURS EARLY THIS
EVENING AS VARIOUS CAMS HAVE SHOWN DURING THE DAY. THE NORTHERN EDGE
OF THE LIGHT RAIN WILL ALSO EXTEND EASTWARD TO EAU CLAIRE COUNTY
IN WI. RAIN AMOUNTS WILL ONLY BE A FEW HUNDREDTHS LOCALLY WITH THE
HEAVIER AMOUNTS OF A QUARTER TO A HALF INCH FARTHER SOUTH. ANOTHER
ISSUE THIS EVENING IS THE BRISK TO OUTRIGHT WINDY NORTHEAST WINDS
DUE TO THE TIGHT PRESSURE GRADIENT ACROSS THE AREA ALONG WITH
EVAPORATIVE COOLING FROM THE FALLING RAIN. THE STRONGEST WINDS
ARE EXPECTED ALONG I-90 WHERE SPEEDS COULD APPROACH 30 MPH
SUSTAINED WITH A FEW GUSTS TO 45 MPH.

THE UPPER LOW WILL BECOME AN OPEN WAVE ON SUNDAY WHILE MOVING TO
THE WESTERN GREAT LAKES BY EVENING. LINGERING AREAS OF LIGHT RAIN
ARE POSSIBLE FROM SOUTHEAST MN THROUGH EAU CLAIRE THROUGH AT LEAST
THE MORNING HOURS. THERE WILL BE A GOOD DEAL OF SUNSHINE TO THE
WEST AND NORTH. HIGHS TOMORROW WILL BE CLOSE TO SEASONAL VALUES
WITH READINGS IN THE UPPER 50S TO LOWER 60S.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 332 PM CDT SAT APR 30 2016

DRY WEATHER AND WARMING TEMPERATURES ARE EXPECTED THROUGH THE LONG
TERM WITH GRADUALLY BUILDING HEIGHTS EARLY TO MIDDLE NEXT WEEK.
THERE WILL BE A COLD FRONTAL PASSAGE TUESDAY NIGHT INTO WEDNESDAY
WHICH WILL DROP TEMPERATURES BACK SEVERAL DEGREES AND PERHAPS BRING
A FEW SHOWERS TO MN/WI. AFTER THE COLD FRONT...A HIGHLY AMPLIFIED
TROUGH-RIDGE-TROUGH PATTERN SETS UP BY THE END OF THE WEEK. THE
FORECAST AREA WILL BE MORE UNDER THE RIDGE AND WILL LIKELY SEE ABOVE
NORMAL TEMPERATURES LATE NEXT WEEK.

ON MONDAY...THE FORECAST AREA WILL BE UNDER THE INFLUENCE OF A
SURFACE HIGH AND DRIER BOUNDARY LAYER UNDER WEAK NORTHWEST FLOW.
THERE MAY BE SOME AFTERNOON FAIR WEATHER CUMULUS CLOUDS MONDAY...BUT
WE THINK THERE WILL BE AT LEAST SOME SUNSHINE AND IT SHOULD FEEL
MILD WITH A LIGHT WIND AND AFTERNOON TEMPS IN THE MID TO UPPER 60S.
THE FLOW INCREASES OUT OF THE NORTHWEST ON TUESDAY WITH DEEP MIXING.
TUESDAY WILL BE WINDY. EVEN WITH THE NORTHWEST FLOW...WE GET WARM
ADVECTION FROM THE NORTHERN HIGH PLAINS THROUGH THE MORNING AND
EARLY AFTERNOON BEFORE COOLER AIR EVENTUALLY FROM CANADA ARRIVES.
THAT NARROW RIBBON OF WARM AIR SHOULD ALLOW TEMPERATURES TO JUMP
INTO THE LOWER 70S BEFORE THE COOLER AIR ARRIVES. WED-THU WILL BE A
BIT COOLER IN THE WAKE OF THIS FRONT /ESPECIALLY IN WI/...BUT
BUILDING HEIGHTS ARE EXPECTED BY FRIDAY AND THE WARMING TREND WILL
CONTINUE INTO NEXT WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1230 PM CDT SAT APR 30 2016

RAIN ACROSS FAR SOUTHERN MN AT MIDDAY WILL PROGRESS SLOWLY
NORTHWARD THIS AFTERNOON AND BECOME MORE PATCHY. THESE PATCHES
WILL THEN BRUSH THE SOUTHERN TWIN CITIES METRO TO KEAU DURING THE
LATE AFTERNOON AND EVENING. KRWF MAY ALSO SEE SOME LIGHT RAIN
DURING THE AFOREMENTIONED PERIOD. ALTHOUGH VFR IS FORECAST THROUGH
THE PERIOD AT THE TAF SITES...KRWF HAS A SMALL THREAT FOR LOW MVFR
CEILINGS EARLY TONIGHT IF THE RAIN LATE TODAY AND THIS EVENING
BECOMES MORE WIDESPREAD THAN FORECAST. IN ADDITION...CEILINGS IN
THE 040-050 RANGE ARE LIKELY ON THE NORTHERN FRINGE OF THE RAIN
AREA. THIS WOULD IMPACT KRNH AND KEAU. NORTHEAST WINDS THIS
AFTERNOON AND EARLY EVENING WITH SPEEDS FROM 15-20 KNOTS WITH
GUSTS IN 24-28 KNOT RANGE. THE WIND WILL SETTLE DOWN EARLY TONIGHT
WITH SPEEDS AROUND 10 KNOTS.

KMSP...VFR THROUGH THE PERIOD WITH CEILINGS 040-050 FOR THE LATE
AFTERNOON AND EVENING HOURS. LIGHT RAIN WILL BE JUST SOUTH OF THE
AIRFIELD THIS EVENING WITH A FEW LIGHT PATCHES OF RAIN BRUSHING
THE AIRFIELD. NORTHEAST WINDS (050-070) NEAR 20 KNOTS THIS
AFTERNOON DIMINISHING TO 10 KNOTS BY EARLY EVENING.

/OUTLOOK FOR KMSP/
MON...VFR. WIND W AT 5-10KTS.
TUE...VFR. WIND WNW-NW AT 10G20KTS.
WED...VFR. WIND N AT 10 KTS.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&

$$

SHORT TERM...RAH
LONG TERM...CLF
AVIATION...RAH


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