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000
FXUS63 KMKX 080322
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
922 PM CST FRI MAR 7 2014

.UPDATE...SYNOPTIC SCALE FORCING ASSOCD WITH RIGHT ENTRANCE REGION
OF UPPER JET AND FRONTOGENETICAL FORCING IN VICINITY OF PASSING
COLD FRONT HAS CAUSED PATCHY MOSTLY -RA OVER SOUTHERN WI THIS
EVENING. TOP DOWN P-TYPE ESTIMATES AND DUAL POL METHODS SHOW THERE
MAY BE SOME SLEET MIXED IN WITH THE RAIN. BACK EDGE OF THIS AREA
OF -RA OVER SOUTH CENTRAL WI MOVING TO THE EAST. HOWEVER CAN NOT
TOTALLY REMOVE POPS AS SECONDARY AREA OF SYNOPTIC SCALE FORCING
WITH UPSTREAM MID-LEVEL SHORT WAVE OVER SRN MN/WRN IA MAY YET
BRING ANOTHER SURGE OF LIGHT PRECIP INTO SOUTHERN WI OVERNIGHT.
RADAR MOSAIC IS SHOWING RESURGENCE OF DBZ OVER CENTRAL AND
NORTHERN IA LAST HOUR OR SO. BUMPED UP OVERNIGHT LOWS A FEW
DEGREES MOST AREAS AS WELL.

&&

.AVIATION/06Z TAFS/...MOSTLY MVFR CONDITIONS TO CONTINUE INTO
SATURDAY AS COLDER AIR SETTLES OVER SOUTHERN WI.

&&

.MARINE...TIGHTENING PRESSURE GRADIENT BEHIND DEPARTING COLD FRONT
MAY RESULT IN OCCASIONAL WIND GUSTS TO 25 KNOTS LATER TONIGHT INTO
SATURDAY MORNING. HOWEVER DUE TO BORDERLINE SITUATION AND
WIDESPREAD ICE REMAINING OVER THE NEARSHORE WATERS...WILL HOLD OFF
ON ISSUING SMALL CRAFT ADVY.

&&

.PREV DISCUSSION... /ISSUED 336 PM CST FRI MAR 7 2014/

SHORT TERM...

LOW LEVEL FRONTOGENESIS AND SURFACE COLD FRONT WILL BE PUSHING
THROUGH THE REGION THIS EVENING. DRY AIR AT LOWER LEVELS SHOULD HOLD
OFF ANY PRECIP UNTIL THE LATE EVENING. RIGHT ENTRANCE REGION OF AN
UPPER JET AND MODERATE OMEGA WILL PROVIDE SOME LIFT...HOWEVER THERE
IS BETTER OMEGA EARLY SATURDAY MORNING OVER ILLINOIS WHERE GREATER
PRECIPITATION IS EXPECTED. LATEST NAM HAS BACKED OFF ON PRECIP
KEEPING ALL BUT THE FAR SOUTHERN COUNTIES DRY. GFS IS AN OUTLIER
WITH SLIGHLTY HIGHER PRECIP AMOUNTS. MODEL CONSENSUS IS FOR A FEW
TENTHS OF AN INCH OF PRECIP OVERNIGHT. EXPECTING A RAIN/SNOW MIX
WITH ANY PRECIP LATE THIS EVENING AND THEN A DUSTING OF SNOW IS
POSSIBLE AFTER MIDNIGHT...MAINLY SOUTH OF MADISON AND MILWAUKEE
WHERE THE FORCING IS BETTER.

HIGH PRESSURE PUSHES IN FROM THE NORTHWEST ON SATURDAY ENDING PRECIP
CHANCES BY DAYBREAK. SKIES ARE EXPECTED TO CLEAR DURING THE
AFTERNOON.

SATURDAY NIGHT AND SUNDAY...FORECAST CONFIDENCE...HIGH

NORTHWEST MID/UPPER FLOW BEHIND THE DEPARTING TROUGH. WEAK UPPER
DIVERGENCE ON SUNDAY...ALONG WITH WEAK 700 MB UPWARD MOTION...BUT
700 MB RH IS RATHER LOW SO EXPECT MAINLY HIGH LEVEL CLOUDS AHEAD
OF THE APPROACHING UPPER LEVEL JET MAX. ALTHOUGH SOME HIGH MID
LEVEL CLOUDS POSSIBLE.

850/700 MB WARM AIR ADVECTION BEGINS LATER SATURDAY NIGHT AND
CONTINUES SUNDAY WITH 850 MB TEMPERATURES RISING TO AROUND
4 CELSIUS. FAIRLY BRISK SOUTHWEST LOW LEVEL FLOW.

SUNDAY NIGHT AND MONDAY...FORECAST CONFIDENCE...MEDIUM

MID/UPPER FLOW IS MORE ZONAL ON MONDAY. MILDER TEMPERATURES
EXPECTED MONDAY WITH THE WEST FLOW AT LOWER LEVELS.

LONG TERM...

TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE...MEDIUM

MID/UPPER FLOW IS ZONAL BEFORE A SHORTWAVE DROPS INTO THE HIGH
PLAINS TUESDAY. THE 00Z ECMWF IS MORE PROGRESSIVE WITH THIS
TROUGH...MOVING IT INTO THE KANSAS AND OKLAHOMA AREA TUESDAY
NIGHT...AND TOWARDS THE KENTUCKY/TENNESSEE AREA WEDNESDAY.
MEANWHILE THE GFS AND 06Z DGEX KEEP THE TROUGH BACK TOWARDS UTAH
AND COLORADO. ALL MODELS DROP A NORTHERN STREAM SHORTWAVE INTO
WISCONSIN WEDNESDAY.

SOME LIGHT PRECIPITATION ON THE GFS AND ECMWF LATE TUESDAY...BUT
THE ECMWF IS DRIER.

THE MAIN SURFACE LOW MOVES ACROSS THE KENTUCKY AND TENNESSEE
VALLEY WITH WEAK HIGH PRESSURE ACROSS WISCONSIN.

TEMPERATURES COOL ON WEDNESDAY.

THURSDAY AND FRIDAY...FORECAST CONFIDENCE...MEDIUM

THE MAIN TROUGH PUSHES ACROSS THE EASTERN U.S. WEDNESDAY NIGHT AND
THURSDAY WITH A SECOND NORTHERN STREAM SHORTWAVE MOVING INTO THE
UPPER GREAT LAKES LATER FRIDAY.

WARM ADVECTION BEGINS THURSDAY AS LOW PRESSURE MOVES ACROSS SOUTH
CENTRAL CANADA. WEAK COLD ADVECTION THURSDAY NIGHT AND FRIDAY
AS THE LOW MOVES INTO SOUTHEAST CANADA.

AVIATION/00Z TAFS/...

MVFR CIGS CONTINUE TO PUSH IN FROM THE WEST AND WILL OVERSPREAD ALL
OF SOUTHERN WISCONSIN BY LATE AFTERNOON. A SHORTWAVE AND COLD FRONT
WILL BRING A CHANCE FOR RAIN AND SNOW SHOWERS MAINLY DURING THE
EVENING HOURS. SOME QUESTION AS TO PRECIP TYPE...WITH MODEL
SOUNDINGS RIGHT AT THE RAIN/SNOW THRESHOLD. EITHER WAY...PRECIP
AMOUNTS ARE EXPECTED TO BE LIGHT.

MODELS ARE NOT IN GREAT AGREEMENT WITH THE PLACEMENT OF
PRECIP...WITH THE NAM AND MESO MODELS PAINTING OUT A NARROW STRIP
ACROSS THE CENTRAL FORECAST AREA...GENERALLY FROM LONE ROCK TO
MADISON TO MILWAUKEE. THESE MODELS MAINLY KEEP IT DRY NORTH TOWARD
FOND DU LAC AND SOUTH TOWARD THE ILLINOIS BORDER. OTHER MODELS SUCH
AS THE GFS AND ECMWF HAVE BEEN SHOWING A BROADER AREA OF PRECIP.
HAVE JUST KEPT PRECIP AT ALL TAF SITES FOR NOW...BUT WILL KEEP AN
EYE ON RADAR TRENDS OVER THE NEXT FEW HOURS.

LOWER CIGS ARE EXPECTED AS THE FRONT/PRECIP MOVE THROUGH...AND THEN
BEHIND THE FRONT AS COLDER AIR MOVES IN. WILL LIKELY SEE A RETURN TO
VFR TOMORROW AS HIGH PRESSURE APPROACHES.

&&

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

$$

UPDATE...MBK