442  
FXUS63 KMQT 282044  
AFDMQT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MARQUETTE MI  
444 PM EDT WED JUN 28 2017  
   
SHORT TERM
 
(THIS EVENING THROUGH THURSDAY)  
ISSUED AT 256 PM EDT WED JUN 28 2017  
 
THE BREAK IN PRECIPITATION ACROSS THE U.P. IS SLOWLY COMING TO AN  
END, WITH A WEATHER SYSTEM APPROACHING FROM THE SOUTHWEST THIS  
EVENING. VISIBLE SATELLITE IMAGERY SHOWS AN EXPANSIVE AREA OF CLOUD  
COVER ACROSS THE GREAT LAKES/UPPER MIDWEST; HOWEVER, SOME CLOUDS  
HAVE BEEN ABLE TO ERODE WITH AFTERNOON HEATING ACROSS PORTIONS OF  
SOUTHERN MN/IA/MO. WATER VAPOR IMAGERY INDICATES A LOBE OF VORTICITY  
EMBEDDED WITHIN THE INVERTED TROUGH AXIS ACROSS NORTHEAST IOWA,  
WHICH IS CLOSER TO THE GREATEST INSTABILITY AREA OF EASTERN  
IOWA/NORTHERN ILLINOIS/SOUTHWEST WISC. FORECAST GUIDANCE THROUGHOUT  
THE DAY HAS MAINTAINED DIFFLUENT FLOW OVER THE U.P. WHICH IS HELPING  
TO DIMINISH THE LEADING EDGE OF PRECIP, AND THIS APPEARS TO BE THE  
CASE THROUGH 21Z. HEIGHTS ARE THEN PROGGED TO FALL, WITH THE VORT  
LOBE LIFTING NORTHEAST ACROSS CENTRAL WISC BUT ALSO WEAKENING. THE  
WARM/MOIST CONVEYOR IF PROGGED TO LIFT NORTH OVER CENTRAL/EASTERN  
U.P. WITH THE STEADIER PRECIP STILL POSITIONED ALONG A MENOMINEE  
COUNTY TO SOUTHERN LUCE COUNTY. AS ELUDED TO EARLIER, GUIDANCE HAS  
BEEN TRENDING TOWARDS LESS QPF THROUGH THE EVENT. BUT THIS COULD ALL  
DEPEND ON UPSTREAM CONVECTION, WHICH IS STRUGGLING AT PRESENT TO  
DEVELOP. WITH MORE THUNDERSTORM ACTIVITY OVER SOUTHERN WISC/IOWA/IL,  
THIS WOULD HELP TO SHUNT THE HEAVIER PRECIP AXIS FURTHER SOUTH. HAVE  
TRENDED LOWER WITH QPF AS A REFLECTION OF THIS THINKING, WITH  
BETWEEN 0.5" TO 0.8" FOR CENTRAL/WESTERN U.P. AND 1" TO 1.3" FOR  
MENOMINEE/LUCE AXIS. THERE DOES REMAIN SOME INSTABILITY THROUGH THE  
PROFILE OVERNIGHT, MAINLY WITHIN THE 00-06Z TIMEFRAME, WHICH COULD  
STILL SUPPORT SOME EMBEDDED OR ISOLATED CONVECTION. GIVEN THE MOIST  
AIRMASS, SOME BRIEF HEAVIER DOWNPOURS IS PLAUSIBLE AND COULD EASILY  
PUSH QPF TOTALS HIGHER FOR THOSE RESPECTIVE AREA.  
 
TEMPS TONIGHT WILL REMAIN MILD WITH THE WARM/MOIST AIRMASS IN PLACE,  
PUSHING DEWPOINTS INTO THE UPPER 50S TO LOWER 60S. THIS WILL KEEP  
OVERNIGHT LOWS SIMILAR TO TD'S. THE BAGGY GRADIENT MAY PRODUCE SOME  
PATCHY FOG AS WELL, BUT THIS APPEARS TO BE MORE FOCUSED IN THE  
EASTERN CWFA AFTER MIDNIGHT.  
 
THURSDAY...TROUGH AXIS WILL CONTINUE TO PIVOT EAST, BEING OVERHEAD  
OF THE U.P. AROUND DAYBREAK. THEN CONTINUEING TO PUSH EAST  
THROUGHOUT THE DAY, WITH HEIGHT RISES BEGINNING TO APPROACH FROM  
WEST TO EAST BY EARLY AFTERNOON. DRY WEATHER IS THEN PROGGED TO  
RETURN. HIGHS FOR THUR WILL WARM INTO THE UPPER 60S TO LOWER 70S,  
WITH AREAS ADJACENT TO LAKE SUPERIOR EXPERIENCING A SHADOW EFFECT  
AND REMAINING SEVERAL DEGREES COOLER THAN INLAND LOCATIONS.  
   
LONG TERM
 
(THURSDAY NIGHT THROUGH WEDNESDAY)  
ISSUED AT 440 PM EDT WED JUN 28 2017  
 
MODELS SUGGEST THAT A SLOWLY PROGRESSIVE PATTERN WILL PREVAIL  
WITH ZONAL FLOW GIVING WAY TO TROUGHING THROUGH THE NORTH CENTRAL  
CONUS THIS WEEKEND AS A MID LEVEL LOW MOVES FROM NORTHERN MANITOBA  
TO NEAR THE NORTHERN GREAT LAKES. A RIDGE WILL THEN BUILD FROM  
THE NORTHERN PLAINS INTO THE UPPER GREAT LAKES FOR THE FIRST HALF  
OF NEXT WEEK. TEMPERATURES WILL REMAIN BELOW NORMAL WITH  
MODERATION CLOSER TO SEASONAL AVERAGES EARLY NEXT WEEK.  
 
THURSDAY NIGHT INTO FRIDAY, AS THE LARGER SCALE MID LEVEL TROUGH  
DEEPENS FROM THE NORTHERN PLAINS INTO THE UPPER GREAT LAKES, A  
SHORTWAVE TROUGH AND ASSOCIATED SFC LOW IS EXPECTED TO LIFT FROM THE  
CENTRAL PLAINS INTO THE WESTERN GREAT LAKES. ALTHOUGH THE  
STRONGER CONVECTION THURSDAY NIGHT SHOULD REMAIN WELL TO THE SOUTH  
OVER SRN WI, AND FCST 700-300MB QVECTOR CONV BY FRIDAY WITH THIS  
FEATURE IS RELATIVELY WEAK, DIURNAL HEATING SHOULD BE STRONG  
ENOUGH TO SUPPORT SCT/ISOLD SHRA AND A FEW TSRA.  
 
SATURDAY-SUNDAY, WITH THE MID-LEVEL TROUGH DEEPENING INTO THE  
NORTHERN GREAT LAKES, RAIN CHANCES WILL INCREASE SATURDAY,  
ESPECIALLY INLAND DURING PEAK HEATING. ISOLATED T-STORMS WILL ALSO  
BE POSSIBLE CNTRL AS MLCAPE VALUES APPROACH 500-1000 J/KG. ENOUGH  
MOISTURE/INSTABILITY WILL LINGER INTO SUNDAY AS THE MID LEVEL LOW  
OR SHRTWV DROPS THROUGH NRN ONTARIO OR EVEN TO LAKE SUPERIOR TO  
SUPPORT LOW CHC POPS FOR MAINLY AFTERNOON ISOLD TO SCATTERED  
SHOWERS.  
 
MONDAY-WEDNESDAY, MODELS AND ENSEMBLES WERE IN GOOD AGREEMENT  
WITH THE DRYING TREND EXPECTED AT LEAST FOR THE FIRST HALF OF NEXT  
WEEK AS MID-LEVEL AND SFC RIDGING BUILD INTO THE AREA. WITH A  
GRADUAL WARMING TREND, SUNSHINE SHOULD PUSH TEMPS WELL INTO THE  
70S MON/TUE TO AROUND 80 BY WED. LAKE BREEZES SHOULD KEEP READINGS  
MAINLY IN THE 60S TO AROUND 70 ALONG THE GREAT LAKES.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)  
ISSUED AT 256 PM EDT WED JUN 28 2017  
 
VFR CONDS ARE STILL HOLDING AT TAF SITES; HOWEVER, VISIBLE  
SATELLITE IMAGERY INDICATES UPSTREAM OBS ARE LOWERING DUE TO THE  
MOISTENING AIRMASS THAT IS EXPECTED TO ARRIVE TONIGHT. LEADING  
EDGE OF PRECIP HAS STRUGGLED TO LIFT NORTHEAST TOWARDS IWD/SAW;  
HOWEVER, EXPECT LATER TONIGHT PRECIP COVERAGE TO INCREASE ALONG  
WITH INTENSITY INCREASING. THERE DOES REMAIN A POSSIBLE  
THUNDERSTORMS COULD APPROACH IWD/SAW, BUT TIMING IS CURRENTLY  
DIFFICULT TO PIN-DOWN. VFR CONDS ARE EXPECTED TO STEADILY LOWER  
THIS EVENING, HEADING TOWARDS IFR CIGS WITH VSBYS HOLDING AROUND  
MVFR. AFTER 6Z, THE GRADIENT BECOMES WEAK AND THIS MAY ALLOW CIGS  
AND VSBYS TO FALL FURTHER TOWARDS LIFR CONDS. AFTER DAYBREAK THUR,  
CIGS/VSBYS WILL BE SLOW TO RECOVER BUT EXPECT PRECIP TO SHIFT EAST  
BY MID-MORNING AND VFR CONDS RETURNING BY 18Z THUR IF NOT SLIGHTLY  
EARLIER.  

 
   
MARINE
 
(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)  
ISSUED AT 256 PM EDT WED JUN 28 2017  
 
AHEAD OF A LOW PRESSURE SYSTEM THE GRADIENT INCREASES OVER LAKE  
MICHIGAN, WITH GUSTS APPROACHING 25 TO 30 KT AT TIMES THIS  
EVENING/OVERNIGHT. ACROSS LAKE SUPERIOR THE GRADIENT IS NOT AS  
ROBUST; HOWEVER, WINDS MAY APPROACH SMALL CRAFT ADVISORY CONDITIONS  
AT TIMES FOR PORTIONS OF LAKE SUPERIOR EAST OF THE KEWEENAW  
PENINSULA. THE LOW LIFTS NORTHEAST TONIGHT, AND COULD ALLOW MARINE  
FOG TO DEVELOP. WITH WINDS TURNING WEST/NORTHWEST, EXPECT ANY FOG TO  
BE CONFINED TO THE EAST GIVEN THE SHORT-WINDOW FOR DEVELOPMENT.  

 
   
MQT WATCHES/WARNINGS/ADVISORIES
 
 
UPPER MICHIGAN...  
BEACH HAZARDS STATEMENT UNTIL 9 PM EDT THIS EVENING FOR MIZ014.  
 
LAKE SUPERIOR...  
NONE.  
LAKE MICHIGAN...  
NONE.  

 
 

 
 
SHORT TERM...BEACHLER  
LONG TERM...- NONE -  
AVIATION...BEACHLER  
MARINE...BEACHLER  
 
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