308 FXUS63 KMKX 072112 AFDMKE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 310 PM CST FRI MAR 7 2003 FCST FOCUS ON SNOW AMOUNTS FOR SAT. SKIES SHLD RMN MOCLDY TNT...AS INVERSION EXPECTED TO REMAIN NEAR 850MB ACROSS CWA...KEEPING LOW LVLS MOIST. INVERSION ALSO EXPECTED TO HELP WINDS DECOUPLE EARLY TNT. THIS SHOULD COMBINE WITH THE SNOW COVER OVR CWA TO PRODUCE PATCHY FOG LATER TNT. TEMPS TO STAY IN MID- UPR 20S TNT...AS CLDS TRAP LONGWAVE RADIATION FM GND. ATTN THEN TURNS TO QUICK-MOVING CYCLONE FOR SAT...AND AMOUNTS OF SNOW WITH IT. STG 850-800MB FRONTOGENESIS/Q-VECTOR CONVERGENCE NOTED PER WETZEL INGREDIENTS METHOD BOTH DOWNSTREAM OF SFC CYCLONE AND ALONG CDNFT SAT AM ACROSS CWA. FCST SOUNDINGS INDICATE MOIST LOW AND MID LVLS SAT AM...WITH ABOVE FREEZING LAYER FM 925-850MB EARLY SAT AM. AVN MODEL HAS BEEN THE BEST MODEL RECENTLY WITH THE HANDLING OF THE SFC CYCLONE PROPAGATION AND PRECIP AMOUNTS/PLACEMENTS. THUS...WL LEAN TOWARDS THE AVN SOLUTION WITH THE SFC CYCLONE...BRINGING SFC CYCLONE QUICKLY ACROSS EXTREME SRN CWA SAT AM. THIS SOLUTION BRINGS INVERTED TROUGH AND CDFNT ACROSS CWA DURING THIS TIME AS WELL...LEADING TO STG UPWARD VERTICAL MOTION FM EXPECTED 800-850MB FRONTOGENESIS/Q-VECTOR CONVERGENCE. UWM-MM5 MODEL ALSO SUPPORTS STG LIFT VIA 700MB W-WIND FIELDS. MOISTURE VALUES IN 2-2.5 G/KG RANGE ACROSS CWA SAT AM...AND USING GARCIA METHOD AND ADJUSTING FOR ONLY A 6-HOUR WINDOW FOR PRECIP...WOULD GENERALLY EXPECT A 2-4 INCH SNOWFALL ACROSS CWA. UWM- MM5 QPF ALSO SUPPORTS THESE AMOUNTS. HOWEVER...A FEW THINGS NEED TO BE CONSIDERED. FIRST...THE SERN 1/2 OF CWA SHOULD BE WARM ENOUGH IN LOW LVLS PER FCST SOUNDINGS AND PROGS FOR -RA OR SLEET TO MIX WITH THE -SN EARLY SAT AM. THAT LAYER QUICKLY COOLS AS THE CDFNT AND INVERTED TROUGH APPORACH BY MID-AM SAT...WHICH SHOULD RESULT IN A QUICK CHANGEOVER TO ALL -SN. SO...WOULD TEND TO KEEP SNOW AMOUNTS A LITTLE LOWER THERE. SECOND...CONVECTIVE SNOWFALL IS A CONCERN SAT AM. FCST SOUNDINGS INDICATE SOME FAIRLY STEEP LAPSE RATES ABOVE 750MB...AND WETZEL INGREDIENTS METHOD INDICATES...AFTER ADJUSTING OUTPUT TO MATCH AVN SOLUTION...SOME DECENT VALUES OF PVQ AND PVF OVR CWA IN 600-650MB LAYER. ALTHOUGH BEST MOISTURE AND LIFT IS IN 800-850MB LAYER...AND BEST INSTABILITY IS FURTHER ALOFT PER WETZEL INGREDIENTS CROSS SECTION...INSTABILITY COULD BE AND HAS BEEN OBSERVED IN THE PAST TO BE REALIZED WITH THE STG LIFT...WHICH WOULD BUMP UP SNOW AMOUNTS QUITE A BIT. CONSIDERING THE UNCERTAINTIES WITH THE PLACEMENTS OF MAX LIFT AND INSTABILITY WITH THIS SYSTEM IN THE AVN SOLUTION...WL HOLD OFF ON ADVISORIES FOR NOW. WL GO 2-4 INCHES N 1/2...WITH 2-3 SW CUT AND 1-3 SCNTRL AND SE CUTS. INTENSE...FOCUSED CAA IN WAKE OF LOW SAT AFT AND NGT SHOULD QUICKLY ERODE CLDS. THIS WILL USHER IN MUCH COLDER AIR...AND BRISK NWLY WINDS IN DECENT PRESS GRADIENT SHOULD DROP WIND CHILLS IN -10F TO -20F RANGE LATE SAT NGT. COLD AIRMASS TO STICK AROUND SUN AND MON WITH STG SFC ANTICYCLONE OVR NRN PLAINS. SLOW WARMUP IN EXTENDED PDS...BUT WL KEEP HI TEMPS A LITTLE LOWER THAN MEX MOS...AS GFS REVERTING TO CLIMATOLOGY LATE NEXT WEEK...WHICH DOES NOT USUALLY MATERIALIZE IN EARLY- TO MID-MARCH. .MKX...NONE. $$ WOOD