000 FXUS63 KDVN 170922 AFDMLI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 305 AM CST FRI MAR 17 2000 LATEST SFC AND MSAS ANALYSIS INDICATING LARGE CANADIAN RIDGE CENTER SHIFTING ACRS MN INTO WI...INDUCING CLEAR AND COOL NIGHT ACRS MUCH OF CORN BELT. IR LOOP SHOWS A FEW MID LEVEL CLDS SKIRTING ACRS SOUTHERN WI IN ASSOCIATION WITH SHORT WAVE CURRENTLY OVER THE AREA...ROLLING TOWARD SOUTHERN TIP OF LK MI. SHORT RANGE MODELS SIMILAR IN HANDLING PROGRESSIVE WAVE PATTERN THROUGH THE NEXT 48 HRS. UPPER RIDGING TO BUILD ACRS THE UPPER MIDWEST THROUGH 00Z SAT...BUT NEXT UPSTREAM TROUGH NOW SEEN IN THE W/V IMAGERY ACRS THE NORTHERN INTERMOUNTAIN REGION OF THE WEST COAST LOOKS TO PROGRESS ACRS THE UPPER MS RVR VALLEY BY 00Z SUN. ELONGATED VORT ASSOCIATED WITH THIS FEATURE TO SHEAR ACRS THE UPPER MIDWEST AND BE THE NEXT WX MAKER OF CONCERN FOR LOCAL AREA. UNTIL THEN...SFC RIDGE TO CONTINUE TO BUILD EAST ACRS THE GRT LKS TODAY...MAKING FOR A SUNNY AND NEAR SEASONABLE ST. PATTY'S DAY ACRS THE LOCAL AREA. MAY HAVE TO WATCH FOR SOME LK AFFECT STRATOCU ADVECTED WEST FROM SOUTHERN LK MI IN NORTHEAST H85 FLOW...POSSIBLY TICKLING NORTHEAST PORTIONS OF CWA...BUT WILL LEAVE SUNNY FOR NOW. EAST-NORTHEAST FLOW IN H85 RIDGE CENTER TO EVENTUALLY VEER TO A SOUTH-SOUTHEAST POSITION BY 00Z SAT WITH H85 TEMP RECOVERY TO -5 TO -7 C. FEEL THIS SCENARIO WOULD SUPPORT AT LEAST MID 40S WITH MID-MARCH INSOLATION...WITH SOME UPPER 40S POSSIBLE...EVEN AFTER COLD START. WILL SIDE WITH SLIGHTLY WARMER FWC TODAY...AND MAY EVEN GO BIT ABOVE THIS. NGM ACTUALLY BETTER AT 06Z WITH RIDGE AXIS PLACEMENT AND STRENGTH OVER MN/WI...ALTHOUGH ETA BETTER IN IT/S PRECIP HANDLING OVER EAST MT AND WY. AS UPPER LEVEL TROUGH PUSHES ACRS MN BY 12Z SAT...CORRESPONDING SFC TROUGH/FRONT LOOKS TO PUSH INTO FAR NORTHWEST IA. INCREASING SOUTH- SOUTHWEST H85 FLOW TONIGHT TO ADVECT HIGHER RH/S FROM WEST-TO-EAST OVER THE CWA BY LATE TONIGHT. BEST INITIAL MOISTURE FEED OVER THE LOCAL CWA LOOKS TO OCCUR FROM 12Z-18Z SAT FROM THE WEST GULF...BUT BEST MOISTURE POOLING AT THE LOW TO MID LEVELS PROGGED TO OCCUR OVER THE LOWER MS RVR VALLEY SAT AFTERNOON AND MAY BE INHIBITED FROM STREAMING FURTHER NORTH SOMEWHAT. AS FOR PRECIP POTENTIAL WITH THIS SYSTEM FURTHER NORTH OVER AREA OF CONCERN...AVN AND ESPECIALLY ETA MUCH MORE AGGRESSIVE BLOSSOMING PRE-FRONTAL PRECIP ACRS CENTRAL IA AFTER 06Z SAT THAN THE NGM. THERE LOOKS TO BE A NICE H85-H5 CONVERGENT QG FORCING BAND THAT SWEEPS ACRS THE CWA ON SAT...AS WELL AS FRONTOGENETICAL FORCING AHEAD OF TROUGH. 85+ H85-H5 LMRH/S ALSO SWEEP ACRS THE CWA ON SAT...BUT APPEAR TO LAG BEHIND BEST FORCING SOMEWHAT. TIME SECTIONS SHOW DEEP MOISTURE AND POS OMEGAS TO BUILD ACRS CENTRAL CWA AFTER 15Z SAT... SO LOOKS LIKE BETTER MOISTURE RETURN SCENARIO THIS RUN THAN BEFORE... BUT MAY STILL BE AT QUESTION. BACK TO PRECIP ITSELF...ETA AND AVN CONTINUE TO SHIFT PRECIP INTO EAST IA BY 18Z SAT...WITH ETA MORE PROGRESSIVE THAN AVN. PRECIP THEN TO PROGRESS INTO NORTHWEST IL BY SAT AFTERNOON. SLOWER AVN DOESN/T CLEAR PRECIP OUT OF THE EASTERN PORTIONS OF CWA TIL AFTER 06Z SUN...BUT FEEL THIS MAY BE A BIT SLOW WITH STILL PROGRESSIVE NATURE OF SYSTEM. STILL...WILL EXTEND PRECIP INTO THE NIGHT...ESPECIALLY OVER EASTERN CWA. LOOKING AT THIS LATEST MODEL RUN WITH A SLOWER TROUGH PROGRESSION AND THUS A MORE OPTIMISTIC MOISTURE RETURN...MAY UP POPS ON SAT FOR AREAL COVERAGE...ALTHOUGH FEEL PRECIP STILL GENERALLY LIGHT. AS FOR TYPE OF PRECIP...PROGGED H85 TEMPS AND CRITICAL THICKNESSES SUPPORT MAINLY SNOW ON SAT...BUT FEEL PROGGED BOUNDARY LAYER THERMAL PARAMETERS BEING UNDERDONE IN A WAA SCENARIO. MODELS MAY BE TOO SLUGGISH ON H85 TEMP RETURN WITH VALUES PROGGED AT -2 TO -3 C BY 00Z SUN. 00Z UA ANALYSIS ALREADY INDICATES 0 TO +2 C H85 WARMER TEMP BUBBLE AHEAD OF WEST COAST TROUGH. PRECIP MAY BE MAINLY LIGHT RAIN...BUT MAY THROW IN A CHANCE OF A MIX/RAIN OR SNOW WORDING FOR ONSET AND AGAIN SAT EVENING. LOWER DPTS AND EVAPORATIVE COOLING MAY HELP FOR SOME SNOW POTENTIAL AT TIMES. .DVN... IA...NONE. IL...NONE. MO...NONE. JDH