000
FXUS63 KMKX 172022
AFDMKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
322 PM CDT WED MAR 17 2010
.SHORT TERM...
TONIGHT AND THURSDAY...FORECAST CONFIDENCE...HIGH
UPPER LOW EXITING SOUTHWEST MISSOURI AREA THEN PHASING WITH THE
SOUTHEAST UPPER LOW ON THURSDAY. NORTHERN STREAM SHORT WAVE FROM
THE NORTHERN ROCKIES TO NORTH OF LAKE SUPERIOR...WITH WEST
SOUTHWEST FLOW OVER THE UPPER MIDWEST. WEAK PRESSURE GRADIENT AT
THE SURFACE TONIGHT. DEW POINTS HAVE DROPPED WITH AFTERNOON
HEATING AND MIXING. LAKE BREEZE HAS REACHED AROUND 25 MILES INLAND
BRINGING DEW POINTS UP AND TEMPS DOWN WITH LAKE AIR.
WITH LOW DEW POINTS...NOT EXPECTING MUCH IN THE WAY OF
FOG...EXCEPT IN THE RIVER VALLEYS. HOWEVER WINDS WILL START TO
INCREASE OUT OF THE WSW THU MORNING. WEST WINDS WILL INHIBIT LAKE
BREEZE DEVELOPMENT...SO EXPECTING ANOTHER MILD DAY.
MODEL SOUNDINGS SHOW DECENT MIXING ONCE AGAIN...AND DEW POINTS WILL
DROP AGAIN. FIRE WEATHER CONDITIONS WILL BE MORE OF A CONCERN
WITH THE WINDS PICKING UP.
FRIDAY THROUGH SUNDAY...FORECAST CONFIDENCE...MEDIUM
FRIDAY...UPPER TROUGH SWINGING ACROSS SOUTHERN CANADA TO THE
CENTRAL PLAINS...AIDED BY RIGHT ENTRANCE REGION OF POLAR JET.
MEANWHILE...WESTERN PORTION OF POLAR JET DIVING SOUTH AND MEETING
UP WITH ZONAL SUBTROPICAL JET PRODUCING POTENT SHORTWAVE THAT WILL
HEAD NORTHEAST TOWARDS THE OHIO VALLEY REGION BY SUNDAY MORNING.
MODEL TRENDS ON THE ECMWF HAVE BEEN MORE SOUTHWARD AND SLOWER. NAM
ALSO TRENDS MORE TOWARD ECMWF.
ELONGATED FRONTOGENETIC ZONE OVER THE MIDWEST STRETCHING FROM KS
TO WI WILL SET UP BY FRI NIGHT AND SAT ON NAM...SINKING A BIT
FARTHER SOUTH ON GFS BY SATURDAY.
ECMWF DIVERGES FROM GFS...KEEPING THE CLOSED UPPER LOW FARTHER
SOUTH OVER WESTERN KENTUCKY/TENNESSEE SUNDAY. GFS HAS MORE OF A
TROUGH AXIS. RESULTANT STRONGER SURFACE LOW SPREADS MORE PRECIP
INTO THE SOUTHEAST.
PRECIP TYPE SUGGESTS RAIN INITIALLY...THEN COOLING TEMPS BRINGS
RAIN SNOW MIXTURE THEN MAINLY SNOW. WILL LOWER SNOW AMOUNTS SINCE
QPF IN THE COLDER AREAS OF SOUTH CENTRAL WISCONSIN APPEARS TO BE
LESS THAN EARLIER EXPECTED. ALSO BOUNDARY LAYER TEMPS WILL BE
RATHER WARM. SNOW WILL BE WET AND MELT SOMEWHAT ON ROADS UNLESS
CONVECTION OCCURS.
.LONG TERM...
MONDAY AND TUESDAY...FORECAST CONFIDENCE...MEDIUM
ZONAL FLOW OVER THE UPPER MIDWEST. SURFACE LOW MOVES ACROSS
SOUTHERN CANADA LATER SUNDAY. PREFER THE ECMWF MORE NORTHERN TRACK ON
THIS. THEN HIGH BUILDS OVER THE WESTERN GREAT LAKES MONDAY...AND
OVER THE EASTERN GREAT LAKES BY TUESDAY.
WEDNESDAY...FORECAST CONFIDENCE...MEDIUM
BOTH GFS AND ECMWF SIMILAR IN BRINGING SHORTWAVE INTO THE CENTRAL
PLAINS LATE WEDNESDAY. RESULTANT SURFACE LOW DEVELOPS OVER THE
SOUTHERN PLAINS. SOME WARM AIR ADVECTION CLOUDS AND LIGHT
PRECIPITATION POSSIBLE BY TUESDAY NIGHT AND WEDNESDAY.
&&
.AVIATION...
FR CONDITIONS EXPECTED THROUGH THURSDAY. HIGH PRESSURE
MOVING SOUTH THROUGH THE PLAINS WILL CONTINUE TO BRING QUIET
WEATHER. LIGHT WINDS EARLY TONIGHT WILL GRADUALLY INCREASE AS THEY
SHIFT FROM THE SOUTHWEST TO WEST LATER TONIGHT INTO THURSDAY. WEST
SOUTHWEST WIND GUSTS TO 22 KNOTS POSSIBLE THURSDAY AFTERNOON...WITH
DAYTIME HEATING AND ROBUST MIXING OF LOW LEVEL WINDS TO THE SURFACE.
SCATTERED CIRRUS CLOUDS EARLY ON THURSDAY BECOME BROKEN BY LATE IN
THE DAY.
&&
.MARINE...
THE COOLER NEARSHORE WATERS OF LAKE MICHIGAN...WITH
SURFACE TEMPERATURES IN THE UPPER 30S...SHOULD SUPPORT AN INVERSION
OVER THIS AREA ON THURSDAY. THIS SHOULD SUPPRESS ANY 22 TO 25 KNOT
GUSTS TRYING TO MIX DOWN TO THE SURFACE. THUS...AM NOT ANTICIPATING
SMALL CRAFT ADVISORY LEVEL WINDS FOR THURSDAY.
SMALL CRAFT ADVISORY LEVEL WINDS AND WAVES ARE EXPECTED AT TIMES
FRIDAY NIGHT THROUGH MONDAY...AS TWO SEPARATE LOW PRESSURE SYSTEMS
MOVE THROUGH THE REGION. FOR NOW...WILL JUST MENTION POTENTIAL IN
HAZARDOUS WEATHER OUTLOOK.
&&
.FIRE WEATHER...
HIGHER DEW POINTS IN THE LOWER TO MID 30S SHOULD
SHIFT INTO THE AREA LATER TONIGHT AND THURSDAY. THIS...COMBINED WITH
HIGHS ON THURSDAY IN THE LOWER TO MID 60S...SHOULD YIELD MINIMUM
RELATIVE HUMIDITIES IN THE MID 30 PERCENT RANGE. BREEZY WEST
SOUTHWEST WINDS OF 10 TO 20 MPH ARE EXPECTED DURING THE AFTERNOON.
FURTHER MIXING OUT OF THE DEW POINTS ARE POSSIBLE...THOUGH NOT AS
MUCH AS THIS AFTERNOON GIVEN THE HIGHER VALUES EXPECTED.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
SHORT/LONG TERM...06/HENTZ
AVIATION/MARINE...08/WOOD
