879 FXUS63 KMQT 271950 AFDMQT AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 350 PM EDT THU JUN 27 2013 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 346 PM EDT THU JUN 27 2013 STRONG THUNDERSTORMS WITH HEAVY RAIN...HIGH WINDS AND HAIL POSSIBLE THIS AFTERNOON INTO THE EVENING HOURS. WATER VAPOR AROUND 15Z INDICATED A SHORTWAVE ROTATING INTO THE FAR WESTERN LAKE SUPERIOR FROM THE UPPER LEVEL CLOSED LOW OVER SOUTHERN MANITOBA AND FAR WESTERN ONTARIO. VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS ARE SHOWING CLOUDS BECOMING BROKEN ACROSS MUCH OF THE WESTERN HALF OF THE UPPER PENINSULA. RADAR IS SHOWING THE REMNANTS OF OVERNIGHT CONVECTION CONTINUING TO PRESS EASTWARD INTO FAR EASTERN UPPER MI WITH A FEW SHOWERS AND THUNDERSTORMS POPPING UP OVER NORTHERN WI. AS THIS SHORTWAVE ROTATES INTO THE AREA THROUGH THE AFTERNOON AND EVENING HOURS EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP ALONG AND AHEAD OF THE FEATURE. THIS AFTERNOON INTO TONIGHT...AS THE UPPER LEVEL LOW SHIFTS SOUTHEASTWARD TOWARD THE REGION THIS AFTERNOON INTO THE OVERNIGHT HOURS...SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AND BECOME SCATTERED ACROSS THE REGION WITH THE GREATEST CHANCES OCCURRING THIS AFTERNOON AND EVENING AS BEST FORCING AND THERMODYNAMIC PROFILES EXIST AROUND THAT TIME. SOME OF THE THUNDERSTORMS THIS AFTERNOON INTO THE EARLY EVENING HOURS WILL HAVE THE POTENTIAL TO BECOME SEVERE WITH HIGH WINDS BEING THE PRIMARY THREAT...HOWEVER...HAIL MAY BE A THREAT EARLY ON IN THE EVENT. DCAPE VALUES PROGGED TO BE AROUND 1000 J/KG BY THE HIGHER RESOLUTION MODELS ARE SUPPORTIVE OF STRONG WIND GUSTS ACROSS MUCH OF THE AREA...THIS CAN ALSO BE SEEN BY ANALYZING FORECAST SOUNDINGS ACROSS THE REGION WITH A NOTICEABLE INVERTED V TYPE SOUNDING...INDICATING THE POTENTIAL FOR ENHANCED COOLING OF DOWNDRAFTS. STORM MOTIONS ARE NOT INCREDIBLY IMPRESSIVE WITH SPEEDS ONLY AROUND 20 TO 25 KNOTS FROM AROUND 290 DEGREES. THE HAIL AFOREMENTIONED HAIL THREAT IS EXPECTED TO EXIST LARGELY DUE TO THE BUILD UP OF CAPE ACROSS THE AREA INTO THE AFTERNOON HOURS. MU CAPE VALUES AS OF 16Z ARE ANALYZED TO BE ON THE ORDER OF 2000 J/KG WITH FORECAST VALUES OF AROUND 2600 J/KG THROUGH THE AFTERNOON HOURS...WITH AROUND 800-900 J/KG IN THE HAIL GROWTH ZONE. THIS WILL DEFINITELY SUPPORT HAIL GROWTH...HOWEVER...THE HAIL THREAT IS LIKELY TO REMAIN MARGINAL AS 0-6KM SHEAR VALUES ARE ONLY ON THE ORDER OF 20 TO 25 KNOTS. ALSO INCLUDED PATCHY FOG DURING THE LATE AFTERNOON AND EVENING HOURS AS SHOWERS AND THUNDERSTORMS HELP COOL AND SATURATE THE LOWER LEVELS. FRIDAY...AS THE UPPER LEVEL TROUGH CONTINUES TO PRESS SLOWLY TO THE SOUTHEAST OF THE AREA EXPECT THE CHANCE OF SHOWERS AND THUNDERSTORMS TO LINGER THROUGHOUT MUCH OF THE DAY. THE AXIS OF THE UPPER LEVEL TROUGH WILL BE STRETCHED ACROSS MUCH OF THE UPPER PENINSULA THROUGH MID AFTERNOON. THE COLDER AIR MOVING IN ALOFT ALONG WITH TEMPERATURES REMAINING IN THE LOW TO MID 70S WILL ALLOW ENOUGH INSTABILITY TO REMAIN IN PLACE TO KEEP THE CHANCE OF SHOWERS AND THUNDERSTORMS THROUGHOUT MUCH OF THE DAY. FORCING WILL ALSO BE COLLOCATED WITH THE INCREASED MOISTURE IN THE AREA AS SHOWN BY ANALYZING QDIV AS WELL AS 1000-500MB RH. FREEZING LEVELS DURING THE DAY FRIDAY ARE FORECAST TO DROP TO AROUND 9500FT...WHICH MAY ALLOW SOME OF THE STRONGER STORMS TO PRODUCE PEA SIZED HAIL...HOWEVER THE OVERALL SEVERE WEATHER THREAT FOR FRIDAY IS VERY LOW. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 346 PM EDT THU JUN 27 2013 THE TREND FOR THIS LONG TERM PERIOD WILL THE THE AMPLIFYING 500MB RIDGE OVER THE WESTERN HALF OF THE NATION...AND LOW SETTING UP ACROSS THE EASTERN HALF. A FEW LINGERING SHOWERS OR POSSIBLY EVEN TS COULD BE LINGERING FRIDAY EVENING OVER NE MN AND EXTREME W LAKE SUPERIOR /CO-LOCATED WITH BETTER Q-VECTOR CONVERGENCE AND ML CAPE VALUES OFF THE NAM OF 100-300J/KG. EXPECT A DIMINISHING TREND PRECIP WISE. TO START OUT FRIDAY NIGHT THE WESTERN RIDGE WILL BE ALREADY WELL IN PLACE NEAR THE 4-CORNERS REGION...WITH THE 500MB LOW STRETCHERED ACROSS THE GREAT LAKES /CENTERED OVER THE LOWER GREAT LAKES/. THE LOW OVER THE LOWER GREAT LAKES WILL ELONGATE TOWARD THE TN VALLEY OVER THE WEEKEND...WITH A CUT-OFF LOW FORMING FROM MI AND WI DOWN THROUGH TN SUNDAY NIGHT. AT THE SFC...A LINGERING FROM FROM THE LOWER GREAT LAKES LOW WILL CONTINUE TO WEAKEN AS LARGE HIGH PRESSURE NEARS FROM CENTRAL CANADA AND THE NORTHERN PLAINS. MUCH DRIER AIR WILL SETTLE ACROSS MAINLY W UPPER MI DURING THE DAY SATURDAY...WITH PW VALUES AROUND 0.5IN /OR APPROX 45-50 PERCENT OF NORMAL...WITH ML DEW POINTS NEAR 40F. WITH N-NNE WINDS MAXING OUT AROUND 10KTS OR LESS OFF LAKE SUPERIOR....TEMPS IN THE 60S...AND RECENT RAIN...FIRE CONCERNS SHOULD BE MINIMAL. WHILE THE CENTER OF THE RESPECTABLE SFC 1024MB HIGH MOVES ACROSS NORTHERN ONTARIO SUNDAY AND MONDAY...AND ACROSS JAMES BAY INTO QUEBEC MONDAY NIGHT...THE RIDGE WILL REMAIN ACROSS LAKE SUPERIOR AND MUCH OF WESTERN UPPER MI. THE PESKY TROUGH MAY STILL HAVE SOME INFLUENCE OVER THE EAST THROUGH EARLY TUESDAY...WITH NNE WINDS AT THE SFC AND A BETTER CHANCE OF INCREASED CLOUD COVER. FOR SUNDAY THE DRIER AIR SHOULD BE OVER MAINLY E UPPER MI WITH PW VALUES OF 0.4 TO 0.5IN...ONCE AGAIN ACCOMPANIED BY LIGHTER WINDS OFF LAKE SUPERIOR. THE MAIN AREA OF CONCERN MAY BE MACKINAC AND TO A LESSER EXTENT CHIPPEWA AS MUCH DRIER AIR IS PULLED DOWN FROM ONTARIO AND QUEBEC. 850MB TEMPS WILL NOT BE UP TO THE 16C THAT WE HAD ON WEDNESDAY...BUT MORE IN THE 10-12C RANGE...WITH SFC TEMPS HOVERING AT OR MORE THAN LIKELY SLIGHTLY BELOW NORMAL THROUGH THE START OF THE NEXT WORK WEEK. EXPECT THE 500MB LOW TO RETROGRADE ACROSS IL AND MO FOR MONDAY AND TUESDAY...BEFORE DRIFTING BACK N AGAIN ON WEDNESDAY. THE 27/00Z ECMWF AND PAST 2 RUNS OF THE GFS SHOW SIMILAR TRENDS. THE GFS HAS BEEN QUICKER TO PULL THE LOW NORTHWARD ACROSS THE UPPER GREAT LAKES AS EARLY AS TUESDAY...WITH THE ECMWF HOLDING OFF UNTIL CLOSER TO WEDNESDAY NIGHT. THE OVERALL TREND FOR OUR AREA WILL BE DRY WEATHER UNTIL THROUGH TUESDAY...WITH MORE SIGNIFICANT DIFFERENCES COMING INTO PLAY FOR THE LAST FEW DAYS OF THIS FORECAST WITH THE TIMING OF WAVES SPINNING AROUND THE NEARING 500MB LOW AND WEAKENING SFC HIGH AS A TROUGH SLOWLY EDGES EASTWARD FROM MN TUESDAY AND WEDNESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 134 PM EDT THU JUN 27 2013 MUCH OF THE FOG ACROSS THE TAF SITES LINGERING AROUND EARLIER THIS MORNING HAS NOW BURNED OFF AND MIXED UP CREATING OCCASIONAL LOW CLOUD BASES IN THE IFR CATEGORY. THE MAIN ISSUE FOR THE TAF SITES THIS AFTERNOON INTO THE OVERNIGHT HOURS...AND AGAIN DURING THE DAY FRIDAY WILL BE THE CHANCES OF CONVECTION EFFECTING THE TAF SITES. MANY OF THE HIGH RES MODELS ARE INDICATING THAT CONVECTION WILL BEGIN DEVELOPING ACROSS MAINLY THE IWD AND SAW TAF SITES THROUGH MID AFTERNOON AND LINGER INTERMITTENTLY THROUGH THE LATE EVENING HOURS. THE EXACT TIMING IS VERY DIFFICULT TO PIN DOWN AS STORM INITIATION HAS NOT YET OCCURRED. WINDS OUTSIDE OF THE THUNDERSTORMS SHOULD REMAIN LIGHT...GENERALLY LESS THAN 10 KNOTS WITH VISIBILITY REMAINING MAINLY IN THE VFR RANGE THIS AFTERNOON. OVERNIGHT...VISIBILITY MAY DROP TO IFR OR LOWER DEPENDING LARGELY ON AREAL COVERAGE OF AN CONVECTION THAT DEVELOPS. CONVECTION BASES WILL LIKELY BE AROUND 3-4KFT WITH LOWER CEILINGS POSSIBLE DURING THE MORNING HOURS FRIDAY AS ANY FOG DEVELOPMENT BEGINS TO BURN OFF. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 346 PM EDT THU JUN 27 2013 WINDS ARE EXPECTED TO REMAIN BELOW 20 KTS THROUGH THE PERIOD AS A HIGH PRESSURE PATTERN REMAINS ACROSS THE AREA THROUGH THE FIRST PART OF NEXT WEEK. WARM MOIST AIR OVER THE UPPER GREAT LAKES WILL CONTINUE TO TRAP MOISTURE NEAR THE SURFACE OF THE LAKE KEEPING PATCHY FOG IN THE FORECAST THROUGH FRIDAY AFTERNOON. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KEC LONG TERM...KF AVIATION...KEC MARINE...KEC