000
FXUS63 KMKX 140221
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
921 PM CDT MON MAY 13 2013

.UPDATE...INCREASING SOUTHEAST WINDS AHEAD OF STRENGTHENING WARM
FRONT HAVE PULLED COOL AIR ACROSS ABOUT THE EASTERN THIRD OF CWA
THIS EVENING. TEMPERATURES HAVE FALLEN INTO THE LOWER TO MIDDLE
40S. HENCE NEEDED TO LOWER OVERNIGHT TEMPS A FEW DEGREES ACROSS
MOST OF THE AREA AS EXPECT COOL AIR TO CONTINUE SPREADING WWD
UNTIL WARM FRONT MOVES NORTHWARD LATE TONIGHT AND EARLY TUE.
STRONG PUSH OF WARM AIR ALOFT LACKING LOW LEVEL MOISTURE AND IS
ONLY CAUSING ISOLD -SHRA AND SPRINKLES. EXPECT THIS TREND TO
CONTINUE IN THE EAST FOR SEVERAL MORE HOURS UNTIL SURGE OF WARM
AIR PUSHES EAST OF WI.

SHORT TERM GUIDANCE STILL HAVING DIFFICULTY DISCERNING LOW LEVEL
ATMOSPHERIC MOISTURE. UPSTREAM DEWPTS 5 TO 10 DEGREES COOLER THAN
00Z NAM. HENCE WL CONTINUE DRY FORECAST AHEAD OF APPROACHING COLD
FRONT FOR TUESDAY EVENING AS NAM WARMS DEWPOINTS INTO THE MIDDLE
60S TO LOW 70S. CURRENTLY WIDESPREAD HIGH PRESSURE OVER THE GULF
SUPPRESSING THIS DEEPER MOISTURE...AND DO NOT SEE IT BEING ABLE TO
STREAM NWD IN TIME FOR FRONTAL PASSAGE LATE TUE.

&&

.AVIATION/06Z TAFS/...A VFR PERIOD IS EXPECTED WITH A COOL FRONT
SLIPPING THROUGH SOUTHERN WI TUESDAY EVENING. LOW LEVEL MOISTURE
EXPECTED TO BE LIMITED SO WL NOT INTRODUCE ANY PRECIPITATION AT
THIS TIME.

&&

.MARINE...WITH TIGHTENING PRESSURE GRADIENT OVERNIGHT...EXPECT
WINDS TO REMAIN SOUTHEAST FOR MUCH OF THE NIGHT. 10 TO 20 KNOT
WINDS WILL CONTINUE TO KICK UP WAVES OF 2 TO 4 FEET. EXPECTED WARM
FRONTAL PASSAGE VERY LATE TONIGHT/TUESDAY MORNING MAY TEMPORARILY
CAUSE THE WINDS TO BECOME MORE SOUTHWEST FOR A TIME...BUT
WEAKENING PRESSURE GRADIENT WILL ALLOW THE WINDS TO BECOME ONSHORE
DURING THE AFTERNOON ONCE AGAIN.

&&

.PREV DISCUSSION... /ISSUED 315 PM CDT MON MAY 13 2013/

SHORT TERM...

TONIGHT...FORECAST CONFIDENCE MEDIUM

NAM 700 MILLIBAR FRONTOGENESIS LOCKED INTO ONGOING PRECIP ACRS
ERN MN /NE IA AND WRN WI. THIS PEAKS ACROSS SRN WI AROUND
00Z...WITH THE BEST LIFT OUT OF THE AREA BY AROUND 6Z. WILL PLAY
POPS ACCORDINGLY WITH RESPECT TO TIMING. 850 WAA PRETTY IMPRESSIVE
AS WELL WITH TEMPS GOING FROM 3-4C AT 00Z TO 14-17C BY LATER IN
THE NIGHT. A MORE MILD NIGHT THAN LAST WITH LOWS MAINLY IN THE
40S.

TUESDAY...FORECAST CONFIDENCE MEDIUM

UPPER FLOW TO BE BROADLY ANTICYCLONIC WITH VERY WARM AIRMASS
OVERSPREADING THE AREA. MAIN JET DYNAMICS WELL NORTH. 850 TEMPS IN
THE UPPER TEENS TO LOW 20S CELSIUS WITH 925 TEMPS AVERAGING
19-24C. SO THIS SUGGESTS TEMPS REACHING WELL INTO THE
80S...ESPECIALLY THE FURTHER WEST AND SOUTH WITHIN THE CWA.
EXPECTING SOUTH WINDS TO TURN SOUTHEAST SO COOLER TEMPS NEAR THE
LAKE.

TUESDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE HIGH

A 100 KT JET STREAK AND ASSOCIATED SHORTWAVE TROUGH AND SFC LOW
WILL CONTINUE EWD ACROSS ONTARIO CANADA TUE NT AND OCCLUDE ON
WED. A WAVE OF LOW PRESSURE IS DEPICTED ALONG THE COLD FRONT
ACROSS NRN WI WITH THE TRAILING COOL FROPA EXPECTED OVER SRN WI
LATE TUE NT INTO WED AM. MODELS CONTINUE WITH THEIR HIGH BIAS ON
MOISTURE RETURN AND WITH VERY WARM TEMPS ALOFT AND WEAK SFC
CONVERGENCE THE FRONTAL PASSAGE SHOULD BE DRY.

A WEAK AREA OF W-E HIGH PRESSURE WILL THEN STRETCH FROM THE MID MO
RIVER VALLEY EWD INTO SRN WI FOR LATE WED INTO THU. THE COLD FRONT
WILL STALL TO THE SOUTH OVER CENTRAL IL. THERE IS ONLY SLIGHTLY
LESS COOLER AIR BEHIND THE FRONT AND 850 MB TEMPS AROUND 12C
YIELDS HIGH TEMPS IN THE UPPER 70S TO 80F FOR WED AND THU WITH THE
EXCEPTION OF THE COOLING OF THE LAKE MI LAKE BREEZE.

LONG TERM...

FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM

A SLOW MOVING UPPER TROUGH OVER THE WRN USA WILL MOVE INTO THE
GREAT PLAINS FOR THE WEEKEND AND POSSIBLY REACH THE UPPER MS RIVER
VALLEY ON SUN-MON. THE WARM FRONT WILL MOVE INTO THE VICINITY OF
SRN WI BY FRI AND SLOWLY LIFT NORTH THROUGH THE STATE OVER THE
WEEKEND. THE COLD FRONT WOULD THEN ARRIVE ANYTIME FROM SUNDAY
AFTERNOON INTO MONDAY. WITH THE SLOW MOVEMENT OF THIS SYSTEM THERE
WILL BE PLENTY OF TIME FOR LOW LEVEL MOISTURE TO STREAM INTO THE
REGION. THUS WARM...HUMID...AND UNSTABLE CONDITIONS ARE EXPECTED
WITH ROUNDS AND SHOWERS AND TSTORMS FORECAST.

AVIATION/00Z TAFS/...SURFACE HIGH SHIFTING EAST. MID LEVEL WAA
KICKING OFF A FEW SHRA ACRS ERN MN/NE IA/WRN WI SHIFTING SOUTHEAST.
BASES HIGH IN THE VFR RANGE AS THIS BAND SHIFTS SE. PROGS STILL
SUGGEST SHRA WILL FILL IN ACRS SC WI THIS EVE. BASICALLY IN
CONJUNCTION WITH THIS EASTWARD TRANSLATING TIGHTENING 700 MILLIBAR
BAROCLINIC RIBBON. OVERALL VFR CONDITIONS THIS PERIOD. VERY CLOSE
CALL ON INCLUSION OF LLWS LATER TONIGHT INTO TUESDAY MORNING DUE TO
INCREASE IN SW 875-925 WINDS.

&&

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

$$
UPDATE...MBK