000 FXUS63 KMQT 291959 AFDMQT AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 400 PM EDT FRI AUG 29 2008 .SYNOPSIS... UPPER LEVELS FEATURE A TROUGH OVR ONTARIO INTO GREAT LAKES WHILE A RIDGE HOLDS OVR WESTERN CONUS INTO SW CANADA. SHORTWAVE SLIDING INTO THE TROUGH MAY BRING LGT PCPN TO NRN CWA THIS EVENING...OTHERWISE HIGH PRESSURE BOTH AT THE SFC AND ALOFT WITH DRY WEATHER DOMINATES INTO THE MIDDLE PART OF THE UPCOMING WEEK. && .SHORT TERM (TONIGHT AND SATURDAY)... BATCH OF CLOUDS AND STEEP LAPSE RATES ALOFT CONTRIBUTING TO A FEW LIGHT RETURNS ON KDLH RADAR. STRONGER ECHOES AND LTG STRIKES ARE JUST NORTH OF THE MN ARROWHEAD IN ONTARIO ALONG TRACK OF TAIL OF UPPER LEVEL SHORTWAVE. KEPT ISOLATED POPS FOR SHRA/TSRA OVR LK SUPERIOR THIS EVENING AS SHORTWAVE AND MID LEVEL MOISTURE MOVES EAST. OBS OVR MN INDICATE BASES OF CLOUDS ARE AROUND 10KFT AND NO REAL MOISTURE ADVECTION IS EXPECTED OVR UPR MI. WILL CONTINUE TO CARRY A FEW SPRINKLES ALONG NORTHERN TIER OF CWA AS THE MID CLOUDS ROLL ACROSS. ALL ACTIVITY SHOULD BE DONE BY 03Z SINCE AXIS OF SHORTWAVE IS THROUGH THE AREA BY THEN. ONCE NVA MOVES IN AND WINDS LIGHTEN UP WITH APPROACHING RIDGE TEMPS COULD FALL SWIFTLY LATE TONIGHT IN THE WEST HALF OF CWA. PWAT MIN EXPANDING OVR TIME WILL ONLY ENHANCE RADIATIONAL COOLING POTENTIAL. GIVEN TEMPS IN THIS SECTOR OF THE INCOMING RIDGE FELL INTO THE 30S IN SOUTHERN SASKATCHEWAN THIS MORNING...REALLY SEE NO REASON WHY FAVORED COLD SPOTS IN WRN UPR MI WILL NOT DROP INTO THE UPR 30S. DRY AIR TO BEGIN THE DAY WILL ONLY ENHANCE MIXING WITH FULL SUNSHINE ON SATURDAY. MIXING TO H85-H8 YIELDS MAX TEMPS IN THE LWR-MID 80S INLAND...BUT LAKESHORE AREAS WILL BE COOLER THANKS TO LIGHT WINDS AND LAKE BREEZES. RH VALUES MAY DROP AS LOW AS 25 PCT...BUT LIGHT WINDS WILL OFFSET ANY FIRE WEATHER ISSUES. AFTER COORDINATING WITH FIRE WEATHER OFFICIALS...WILL BE ISSUING A WILDFIRE POTENTIAL STATEMENT FOR THE UPCOMING HOLIDAY WEEKEND DUE TO THE INCREASING TEMPERATURES AND PROLONGED DRY WEATHER (IN SOME SPOTS IN THE CWA). EXPECT INCREASING WILDFIRE POTENTIAL SUNDAY AND MONDAY AS SOUTH WINDS BEGIN TO INCREASE. .LONG TERM (00Z SUN THROUGH DAY 7)... MAIN FCST CONCERNS DURING THIS PERIOD ARE UNSEASONABLY WARM TEMPERATURES FOR SUN/MON/TUE AND ARRIVAL OF NEXT PRECIPITATION FOR WEDNESDAY NIGHT THROUGH FRIDAY. LATEST MODEL RUNS CONTINUE TO SHOW A STRONG UPPER LEVEL RIDGE BUILDING INTO THE UPPER GREAT LAKES BY SUNDAY AFTN/EVENING. BOTH LONG RANGE MODELS...ECMWF/GFS...SHOW SLIGHT DIFFERENCES IN THE STRENGTH OF THE RIDGE...592/590 DM RESPECTIVELY. THIS MINOR DIFFERENCE WILL NOT PRECLUDE THE UNSEASONABLY WARM AIR ASSOCIATED WITH THIS RIDGE FROM BUILDING INTO THE FA FOR LABOR DAY WEEKEND. BOTH SUNDAY AND MONDAY WILL FEEL HOT WITH HIGH TEMPERATURES ACROSS THE WEST HALF WILL REACH WELL INTO THE 80S...SOME AREAS COULD REACH 90 WHERE DOWNSLOPING IS MAXIMIZED. BY TUESDAY EVENING THE RIDGE WILL SHIFT EAST OVER NEW ENGLAND ALLOWING FOR RETURN FLOW AND NEXT PRECIP. CHANCE TO MOVE INTO THE FA. HAD TO DELAY POPS INTO THE FA AS LATEST GUIDANCE SHOWS DRY AIR/REMAINING SUBSIDENCE FROM STRONG RIDGE KEEPING UPPER MICHIGAN DRY THROUGH TUESDAY AFTN. FOR THE TIME BEING IT LOOKS LIKE THE FRONT WILL LINGER TO THE WEST LONG ENOUGH FOR TUE TO BE WARM DAY AS WELL. HIGH TEMPERATURES ON WEDNESDAY ARE A BIT TRICKIER AS THE GFS BRINGS THE FRONT INTO THE WEST WEDNESDAY MORNING..WHILE THE EC NOT ONLY LAGS THE FRONT TO OUR WEST BUT ALSO WEAKENS THE FRONT ALTOGETHER AS IT MOVES INTO UPPER MICHIGAN. AS A RESULT THERE IS 10+ DEGREE DIFFERENCE IN AIRMASS TEMPS FOR WEDNESDAY NIGHT/THURSDAY. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... VFR CONDITIONS TO PREVAIL THROUGH THE FORECAST PERIOD. BATCH OF MID CLOUDS AND INCREASING INSTABILITY ALOFT MAY PRODUCE ISOLD SHRA AT KCMX 22Z-02Z...BUT DUE TO DRY AIR BLO BASE OF MID CLOUDS...EXPECT NO RESTRICTION TO VSBY OR CIGS. AFTER THE SCT-BKN MID CLOUDS TONIGHT...PLAN ON CLEAR SKIES FOR SATURDAY AS HIGH PRESSURE BUILDS INTO REGION. && .MARINE (FOR THE 4 PM MARINE ISSUANCE)... HIGH PRESSURE TO DOMINATE THE REGION FOR THE NEXT SEVERAL DAYS WITH WINDS EXPECTED TO REMAIN LESS THAN 20 KNOTS. AS THE HIGH SHIFTS EAST...DEEPENING LOW PRESSURE OVER THE NORTHERN PLAINS TO RESULT IN INCREASING PRESSURE GRADIENT OVER LAKE SUPERIOR LATER SUNDAY INTO TUESDAY WITH GUSTS UP TO 25 KNOTS. COLD FRONT SHIFTS INTO LAKE SUPERIOR LATE WEDNESDAY INTO THURSDAY. GUSTS ON WEDNESDAY MAY EXCEED 20 KNOTS IN ASSOCIATION WITH THE APPROACHING FRONT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ SHORT TERM DISCUSSION...JLA LONG TERM DISCUSSION...PEARSON AVIATION...JLA MARINE...JLA