773 
FXUS63 KMQT 171719
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
119 PM EDT TUE JUN 17 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 541 AM EDT TUE JUN 17 2014

WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF OVER THE WRN CONUS 
WITH BROAD RIDGE DOWNSTREAM OVER THE E HALF OF THE CONUS. SHORTWAVE 
THAT EJECTED FROM THE WRN TROF LED TO THE EXPECTED MCS DEVELOPMENT 
DURING THE NIGHT ACROSS THE UPPER MISSISSIPPI VALLEY. THE SHORTWAVE 
HAS STRENGTHENED FROM THE CONVECTION AND IS NOW MOVING ACROSS NRN 
WI. THE ASSOCIATED NRN END OF MCS IS MOVING ACROSS SCNTRL UPPER MI 
TOWARD ERN UPPER MI ATTM. TO THE N...A MID LEVEL LOW IS OVER NRN 
ONTARIO. ASSOCIATED ILL-DEFINED SFC FRONTAL BOUNDARY APPEARS TO BE 
NEAR THE N END OF LAKE SUPERIOR. 

MUCH OF THE HIGH RES MODEL GUIDANCE IS LAGGING A BIT BEHIND REALITY 
WITH THE MCS. LARGELY UTILIZED RADAR TRENDS...BUT INCORPORTATED SOME 
OVERALL MODEL GUIDANCE TO SHIFT ONGOING SHRA/ISOLD TSTMS ENE THIS 
MORNING. BULK OF THE PCPN SHOULD EXIT THE ERN FCST AREA AROUND MID 
MORNING IF NOT SOONER. IN THE WAKE OF THE SHORTWAVE AND SHRA... 
CLOUDS WILL THIN TODAY AND A LIGHT WIND REGIME WILL ALLOW LAKE 
BREEZE FORMATION. LAKE BREEZE MAY PROVIDE A TRIGGER FOR ISOLD 
CONVECTION LATER IN THE AFTN TOWARD THE WI BORDER AFTER STRONGER 
SUBSIDENCE IN THE WAKE OF SHORTWAVE DEPARTS. STILL...WITH HEIGHT 
RISES THRU THE DAY...IT APPEARS CONVECTIVE POTENTIAL WILL BE 
LIMITED. THE NAM/GFS SHOW MLCAPES ACROSS THE INTERIOR W HALF OF 
UPPER MI INCREASING TO 1000-2000J/KG THIS AFTN. HOURLY RUC13 RUNS 
ARE MUCH MORE CONSERVATIVE WITH MLCAPE IN THE 200-350J/KG RANGE 
TOWARD THE WI BORDER. THESE LOWER MLCAPES ARE DUE TO MIXED LAYER 
DWPTS BEING 5-10F LOWER THAN THE NAM AND GFS. PREFER THESE LOWER 
VALUES GIVEN THE OVERALL LIGHT WIND FIELDS TODAY THAT WILL LIMIT 
MOISTURE ADVECTION FROM THE S. IN ADDITION...OUTFLOW BOUNDARY FROM 
OVERNIGHT CONVECTION WHICH IS STILL CONTINUING WELL TO THE S IN 
IA/SRN WI/NRN IL WILL KEEP BEST MOISTURE/INSTABILITY HELD UP WELL TO 
THE S OF HERE. 

IF ANY SHRA/TSRA DEVELOP LATE THIS AFTN TOWARD THE WI BORDER...THE 
PCPN MAY LINGER INTO THE EARLY/MID EVENING HRS. OTHERWISE... 
AFOREMENTIONED OUTFLOW BOUNDARY WILL PLAY A SIGNIFICANT ROLE IN 
ANOTHER ROUND OF CONVECTION AND LIKELY MCS DEVELOPMENT TONIGHT AS 
NEXT SHORTWAVE EJECTS FROM WRN TROF. GIVEN HOW FAR S THE BOUNDARY IS 
CURRENTLY...BELIEVE NRN END OF CONVECTION TRIGGERED BY SHORTWAVE  
MAY STAY COMPLETELY S OF UPPER MI. THOUGHT ABOUT REMOVING POPS 
COMPLETLY AFTER ANY EARLY EVENING ISOLD CONVECTION...BUT OPTED TO 
JUST TRIM SCHC/CHC POPS BACK CLOSER TO THE WI/MI BORDER AS EVERY 
AVBL MODEL SHOWS SOME CONVECTION CROSSING THE BORDER TONIGHT. 
PERHAPS THIS NORTHWARD DEVELOPMENT IS SOMEWHAT TIED TO ILL-DEFINED 
BOUNDARY CURRENTLY N OF LAKE SUPERIOR THAT WILL DRIFT S ACROSS THE 
UPPER LAKES TODAY/TONIGHT IN ADVANCE OF BUILDING HUDSON BAY SFC HIGH 
PRES.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 555 AM EDT TUE JUN 17 2014

THE 500MB RIDGE JUST TO OUR W WILL SHIFT ACROSS THE UPPER GREAT 
LAKES/ONTARIO WEDNESDAY NIGHT THROUGH THURSDAY. THE SFC HIGH OVER 
HUDSON BAY AND NORTHERN ONTARIO WILL EXTEND A RIDGE ACROSS UPPER 
MICHIGAN THROUGH THURSDAY...WITH SLIGHTLY COOLER AND DRIER AIR. A 
FEW SHOWERS WILL BE POSSIBLE NEAR THE WISCONSIN BORDER...BUT MOST 
LOCATIONS WILL BE RAIN FREE DURING THIS TIME PERIOD. THE DRIEST AIR 
WILL BE ACROSS THE EASTERN HALF OF UPPER MICHIGAN...WITH HUMIDITY 
VALUES FALLING AS LOW AS 25 TO 35 PERCENT BY THURSDAY AFTERNOON. 
THESE LOW HUMIDITY VALUES THURSDAY WILL LIKELY BE ACCOMPANIED BY 
EAST WINDS OF 10 TO 15 MPH...WHICH HAS BEEN HIGHLIGHTED IN THE 
MORNING FIRE WEATHER FORECAST. THE APPROACHING LOW TO THE W SHOULD 
HELP BRING SOME CLOUDS TO THE CWA...BUT JUST HOW FAR E THEY WILL GET 
DURING THE DAY IS IN QUESTION. CONSENSUS IS TO KEEP THEM OVER MAINLY 
W UPPER MI THROUGH 12Z FRIDAY...AND SLOWLY SWEEP THEM E ACROSS THE 
CWA THROUGH THE DAY AS THE RIDGE SLOWLY EXITS E AND A LOW NEARS FROM 
S CANADA AND THE N PLAINS. WILL LIKELY NEED TO DIMINISH POPS A BIT 
MORE FOR FRIDAY NIGHT...ESPECIALLY IF THE LATEST/SLOWER ECMWF AND 
CANADIAN RUNS ARE CORRECT...AHEAD OF THE MAIN LOW SLIDING IN FROM 
THE NW.

THE MAIN 500MB LOW LOOKS TO SINK ESE ACROSS THE UPPER GREAT LAKES 
LATE SATURDAY THROUGH SUNDAY. WILL LIKELY NEED TO TREND BACK ON POPS 
FOR WHILE FCST POPS ARE IN THE 20-40 PERCENT RANGE SATURDAY THROUGH 
SUNDAY. AT THIS POINT A SOAKING WEEKEND IS NOT ANTICIPATED. DUE THE 
LOWER CONFIDENCE OF WHEN AND WHERE SHOWERS /AND POSSIBLY 
THUNDERSTORMS/ COULD DEVELOP...A BROAD 20-40 PERCENT SEEMS 
REASONABLE FOR NOW. WILL NEED TO DO SOME ADJUSTMENTS TO THESE 
PERIODS AS THE TIME NEARS.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 110 PM EDT TUE JUN 17 2014

VFR CONDITIONS SHOULD PREVAIL AT KIWD/KCMX/KSAW THRU THIS FCST
PERIOD AS LOW-LEVELS REMAIN RELATIVELY DRY UNDER DOMINANT HIGH 
PRESSURE.

&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EDT TUE JUN 17 2014

PATCHY FOG WILL BE DEVELOPING ACROSS LAKE SUPERIOR. 5SM HAS ALREADY 
BEEN REPORTED JUST N OF ONTONAGON EARLY THIS MORNING. ADDITIONAL 
SHOWER ACTIVITY THIS MORNING OVER THE E HALF OF LAKE SUPERIOR WILL 
ONLY ENHANCE THE POTENTIAL FOR FOG...THAT SHOULD CONTINUE INTO 
WEDNESDAY.

A TROUGH OF LOW PRESSURE OVER LAKE SUPERIOR WILL SLOWLY BE REPLACED 
BY A RIDGE THIS EVENING...EXTENDING FROM HIGH PRESSURE ACROSS 
SOUTHERN HUDSON BAY AND NORTHERN ONTARIO. LIGHT WINDS WILL BECOME 
NE...AND FUNNEL OVER THE W HALF OF LAKE SUPERIOR...WITH GUSTS OF 
20-25KTS LATE TONIGHT INTO WEDNESDAY EVENING. THE RIDGE WILL SLOWLY 
SHIFT EAST FRIDAY...AS LOW PRESSURE ACROSS SOUTHERN MANITOBA AND 
NORTH DAKOTA APPROACHES NORTHERN MINNESOTA...BRINGING THE RETURN OF 
THUNDERSTORMS THURSDAY THROUGH SATURDAY. EXPECT THE LOW TO SHIFT 
ACROSS THE UPPER GREAT LAKES ON SATURDAY.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...VOSS
MARINE...KF