655  
FXUS63 KMQT 240504  
AFDMQT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MARQUETTE MI  
104 AM EDT FRI MAR 24 2017  
   
SHORT TERM
 
(THIS EVENING THROUGH FRIDAY)  
ISSUED AT 402 PM EDT THU MAR 23 2017  
 
THIS AFTERNOON TEMPERATURES HAVE BEEN SLOW TO WARM, ESPECIALLY  
ACROSS THE INTERIOR CENTRAL PORTIONS OF THE U.P. GIVEN THE AMPLE  
CLOUD COVER, AS MID AND UPPER LEVEL CLOUDS CONTINUED TO STREAM  
NORTHEAST AHEAD OF A DEVELOPING LEE CYCLONE ACROSS THE HIGH PLAINS  
THIS AFTERNOON. CURRENT RADAR IMAGERY SHOWS RETURNS BEGINNING TO  
SHOW UP ACROSS MUCH OF MINNESOTA; HOWEVER, GIVEN HOW DRY THE AIR  
MASS CURRENTLY IS ONLY A FEW SELECT SITES ARE REPORTING  
PRECIPITATION THIS AFTERNOON.  
 
THE MAIN FORECAST CONCERN TONIGHT THROUGH FRIDAY IS THE POTENTIAL  
FOR FREEZING RAIN, AND POSSIBLY SOME SLEET, ACROSS MUCH OF UPPER  
MICHIGAN TONIGHT INTO THE MORNING HOURS ON FRIDAY. THIS WILL LIKELY  
RESULT IN A SLICK COMMUTE DURING THE MORNING HOURS. MODELS ARE IN  
GOOD AGREEMENT WITH A CONVECTIVE BAND, CURRENTLY DEVELOPING IN  
CENTRAL MINNESOTA, LIFTING NORTHEAST ACROSS MUCH OF UPPER MICHIGAN  
TONIGHT AS WARM AIR ADVECTION/ISENTROPIC LIFT INCREASE AND WORK  
STRENGTHEN A MID-LEVEL BAROCLINIC ZONE. A FEW OF THE MODELS ARE  
SUGGESTING UPWARDS OF AROUND OR EVEN GREAT THAN 0.50'' OF QPF WITH  
THIS HEAVIER BAND. HOWEVER, GIVEN HOW DRY THE LOW-LEVELS ARE,  
CURRENTLY THINKING THE MODELS ARE LIKELY OVERDOING AMOUNTS.  
THEREFORE, HAVE OPTED TO RUN WITH A LOWER QPF, BUT GIVEN THE THERMAL  
PROFILES AND EXPECTED WET-BULBING TONIGHT THIS STILL RESULTED IN  
AROUND QUARTER OF AN INCH OF ICE ACCUMULATIONS ACROSS THE CENTRAL  
PORTIONS OF UPPER MICHIGAN. THE HIGHEST ICE ACCUMULATIONS ARE  
EXPECTED TO OCCUR ACROSS THE INTERIOR AND CENTRAL PORTIONS OF THE  
AREA, ESPECIALLY ACROSS THE HIGHER TERRAIN. THESE LOCATIONS WILL SEE  
MORE COOLING THIS EVENING AND ONCE PRECIPITATION STARTS TO FALL, THE  
WET-BULBING PROCESS WILL ALLOW FOR FREEZING RAIN TO DEVELOP AS WARM  
AIR ADVECTION ALOFT CONTINUES TO STREAM NORTHWARD. ONE CONCERN IS  
THAT THERE MAY BE PERIODS WHEN RAIN MIXES IN WITH THE FREEZING RAIN,  
AND/OR BEGIN TO TRANSITION OVER TO RAIN TOWARDS THE MORNING HOURS.  
THEREFORE, THERE UNCERTAINTY STILL EXISTS IN THE OVERALL ICE  
ACCUMULATIONS. FURTHER TO THE WEST, ICE ACCUMULATIONS ARE STILL  
POSSIBLE; HOWEVER, THE THERMAL PROFILES POINT MORE TOWARDS A MIX OF  
RAIN AND FREEZING RAIN SO ICE ACCUMULATIONS ARE EXPECTED TO BE A BIT  
LESS. ACROSS EASTERN PORTIONS OF THE AREA, A MIXTURE OF SLEET AND  
FREEZING RAIN ARE EXPECTED TO BEGIN LATE TONIGHT. CLOSER TO THE  
LAKE, ICE ACCUMULATIONS ARE EXPECTED TO REMAIN A BIT LESS,  
ESPECIALLY ACROSS WESTERN GOGEBIC COUNTY AND NORTH OF LAKE MICHIGAN  
AS SOUTHERLY WINDS SHOULD KEEP TEMPERATURES JUST ABOVE FREEZING.  
 
LATE FRIDAY MORNING THROUGH THE REST OF THE AFTERNOON, WARM AIR  
ADVECTION WILL WEAKEN AS A WEAK BACK DOOR COLD FRONT PUSHES SOUTH  
ACROSS THE AREA. THIS WILL ALLOW THE FOCUS FOR ADDITIONAL  
PRECIPITATION TO BE ACROSS SOUTH CENTRAL AND EASTERN POTIONS OF  
UPPER MICHIGAN. THE FREEZING RAIN WILL BEGIN TO TRANSITION OVER TO  
RAIN, WITH A FEW LOCATIONS POSSIBLY SEEING SOME SNOW MIXED IN THE  
AFTERNOON NEAR LAKE SUPERIOR. ELSEWHERE, SKIES WILL REMAIN CLOUDY.  
   
LONG TERM
 
(FRIDAY NIGHT THROUGH THURSDAY)  
ISSUED AT 327 PM EDT THU MAR 23 2017  
 
A SPLIT UPR FLOW WL DOMINATE AREAS NEAR THE CNDN BORDER THRU THE  
COMING WEEK. RECENT MODEL TRENDS INDICATE MORE AGGRESSIVE MID LVL  
DRYING ASSOCIATED WITH A NRN BRANCH SHRTWV RDG AXIS/HI PRES IN  
ONTARIO WL PUSH THE TIGHT MSTR GRADIENT ON THE NRN FLANK OF A CLOSED  
LO EMBEDDED IN THE SRN BRANCH FLOW DOMINATING THE CONUS AND TRACKING  
TOWARD THE LOWER GREAT LKS FARTHER TO THE S ON FRI NGT/SAT, REDUCING  
THE POTENTIAL FOR FREEZING RA/ICING DURING THIS TIME. HOWEVER, AS  
THE CLOSED LO DRIFTS TOWARD SRN LOWER MI LATER IN THE WEEKEND  
FOLLOWING THE PASSAGE OF THE SHRTWV RDG/SFC HI PRES TO THE E TOWARD  
QUEBEC, MORE MID LVL MSTR AND THE POTENTIAL FOR SOME LIGHT FREEZING  
RAIN WL RETURN. A BDLG UPR RDG/SFC HUDSON BAY HI PRES WL THEN BRING  
A DRYING TREND MID NEXT WEEK, BUT MORE PCPN MAY RETURN LATER IN THE  
WEEK DEPENDING ON THE TRACK/TIMING OF ANOTHER SRN BRANCH CLOSED LO  
MOVING THRU THE SCENTRAL PLAINS. EXPECT TEMPS THRU THE MEDIUM/  
EXTENDED RANGE TO AVERAGE ABOVE NORMAL, MAINLY DUE TO RELATIVELY  
WARM OVERNGT TEMPS.  
 
FRI NIGHT/SAT...UPR MI WL BE SITUATED NEAR THE EDGE OF A SHARP MID  
LVL MSTR GRADIENT BTWN A SRN BRANCH SLOW MOVING CLOSED LO MOVING  
NEAR THE MID MS RIVER VALLEY AND DRY HI PRES MOVING THRU NW ONTARIO  
UNDER AN UPR RDG AXIS IN THE NRN BRANCH FLOW DOMINATING SRN CANADA.  
THE LATEST MODEL RUNS HAVE TRENDED TOWARD MORE AGGRESSIVE MID LVL  
DRYING AS A MORE EXPANSIVE SFC HI PRES IN ONTARIO DEPRESSES FARTHER  
TO THE S THE AXIS OF DEEPER MSTR ASSOCIATED WITH THE WARM FNT  
EXTENDING FM THE SRN BRANCH LO INTO THE LOWER LKS. AS A RESULT, POPS  
WL BE MAINLY CONFINED TO THE SCENTRAL. FCST SDNGS FOR THIS AREA  
CONTINUES TO SHOW AN ELEVATED WARM LYR ABOVE A NEAR SFC BASED INVRN  
WITH SFC TEMPS NOT FAR FM 32, SO SOME FREEZING RAIN/DRIZZLE WILL  
BE PSBL. AN UPSLOPE ENE WIND INTO THE NCENTRAL MAY ALSO CAUSE SOME  
LIGHT DRIZZLE/FREEZING DRIZZLE IN THESE AREAS DEPENDING ON THE  
DEGREE OF NEAR SFC DRYING WITHIN THE SHALLOW SUB INVRN LYR.  
 
SAT NGT THRU MON NGT...ALTHOUGH THERE ARE SOME DIFFERENCES AMONG THE  
MEDIUM RANGE GUIDANCE, THESE MODELS IN GENERAL SHOW ANOTHER SHRTWV  
MOVING WITHIN THE SRN BRANCH TROF OVER THE SW STATES KICKING THE  
CLOSED LO IN THE MID MS RIVER VALLEY UP TO SRN LOWER MI ON SUN. AS A  
RESULT, MID LVL MSTR IS FCST TO EXPAND SLOWLY BACK INTO THE UPR LKS  
BEGINNING SAT NGT AS THE SFC HI PRES IN ONTARIO SHIFTS INTO QUEBEC.  
THE MAIN FCST CHALLENGE IS THAT THE LLVL FLOW WL REMAIN OUT OF THE  
ENE, WHICH WL ACT TO MAINTAIN SOME COLDER NEAR SFC TEMPS BLO AN  
ELEVATED WARM LYR WITH H85 TEMPS ABOVE 0C, ALLOWING THE POTENTIAL  
FOR MORE FREEZING RAIN, ESPECIALLY AT NGT IN THE ABSENCE OF ANY  
INSOLATION/HIER EARLY SPRING SUN ANGLE. FORTUNATELY, THE SHARPER  
DEEP LYR FORCING IS PROGGED TO REMAIN TO THE S, SO THERE SHOULD BE  
NO SGNFT QPF/ICING.  
 
EXTENDED...AN UPR RDG AXIS IN THE NRN AND SRN STREAMS IS FCST TO  
BUILD BACK INTO NW ONTARIO AND THE MID MS RIVER VALLEY THE MIDDLE OF  
NEXT WEEK, ALLOWING A HUDSON BAY SFC HI PRES TO EXPAND INTO THE WRN  
GREAT LKS. SO AFTER ANY LINGERING PCPN ENDS BY EARLY ON TUE, EXPECT  
DRY WX TO PREVAIL INTO AT LEAST EARLY ON THU, WHEN SOME OF THE  
LONGER RANGE MODELS HINT ANOTHER SRN BRANCH CLOSED LO MAY APRCH FM  
THE SW.  

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)  
ISSUED AT 102 AM EDT FRI MAR 24 2017  
 
EXPECT CONDITIONS TO DETERIORATE OVERNIGHT AS PERIODS OF RAIN AT IWD  
AND FREEZING RAIN (SAW) OR SLEET/SNOW (CMX) RESULTS IN LOW LEVEL  
MOISTENING AND LOWER CIGS. EXPECT MAINLY MVFR CIGS SHOULD DROP TO  
IFR AND LIFR CIGS BY LATE TONIGHT. SLIGHT WARMING INTO FRIDAY  
MORNING SHOULD BRING A TRANSITION TO MAINLY RAIN AT SAW/CMX. DRIER  
AIR MOVING IN WITH NRLY WINDS FRIDAY WILL LIFT TO CIGS MVFR AT  
CMX/IWD BY AFTERNOON WHILE UPSLOPE FLOW INTO SAW MAINTAINS IFR CIGS.  

 
   
MARINE
 
(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)  
ISSUED AT 327 PM EDT THU MAR 23 2017  
 
THE STRONGEST SOUTHERLY WINDS WILL BE CONFINED TO THE EASTERN HALF  
OF THE LAKE WITH SPEEDS OF 20 TO 30 KNOTS. THESE WINDS WILL DIMINISH  
TO AROUND 5 TO 10 KNOTS AND VEER TO THE WEST OVERNIGHT INTO FRIDAY  
MORNING. WEST WINDS WILL VEER NORTH-NORTHEASTERLY AND INCREASE TO 20  
TO 25 KNOTS THROUGH THE AFTERNOON HOURS ON FRIDAY. THEN EXPECT NE  
VEERING E WINDS TO INCREASE UP TO 25 TO PERHAPS 30 KTS ON FRI NIGHT  
INTO SUN UNDER THE TIGHTENING PRES GRADIENT BETWEEN HI PRES PASSING  
FROM ONTARIO INTO QUEBEC AND LO PRES IN THE LOWER GREAT LAKES. THE  
STRONGEST WINDS ARE MOST LIKELY OVER WESTERN LAKE SUPERIOR, WHERE  
THE LAKE TOPOGRAPHY WILL ENHANCE THE ENE FLOW. AS THESE FEATURES  
WEAKEN AND EXIT TO THE E, WINDS WILL DIMINISH ON SUN AND MON. WINDS  
ON TUE SHOULD REMAIN RELATIVELY LIGHT AS HI PRES BUILDS INTO ONTARIO.  

 
   
MQT WATCHES/WARNINGS/ADVISORIES
 
 
UPPER MICHIGAN...  
WINTER WEATHER ADVISORY UNTIL 11 AM EDT /10 AM CDT/ THIS MORNING  
FOR MIZ001>007-009>014-084-085.  
 
LAKE SUPERIOR...  
NONE.  
LAKE MICHIGAN...  
NONE.  

 
 

 
 
SHORT TERM...RITZMAN  
LONG TERM...KC  
AVIATION...JLB  
MARINE...RITZMAN/KC  
 
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