418  
FXUS63 KAPX 190131  
AFDAPX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GAYLORD MI  
831 PM EST FRI JAN 18 2019  
   
UPDATE
 
 
ISSUED AT 831 PM EST FRI JAN 18 2019  
 
STRONG COLD HIGH PRESSURE REMAINS CENTERED OVER CENTRAL CANADA  
WITH SURFACE RIDGING AND VERY COLD AIR EXTENDING INTO THE GREAT  
LAKES REGION. LOW PRESSURE CONTINUES TO DEVELOP OVER THE SOUTHERN  
PLAINS. THE NORTHER EDGE OF THE MOISTURE SHIELD ASSOCIATED WITH  
THIS SYSTEM IS PUSHING INTO SOUTHERN LOWER MICHIGAN LATE THIS  
EVENING...PRODUCING SOME LIGHT SNOW ACROSS SOUTHERN WISCONSIN AND  
SW LOWER MICHIGAN. LATEST KAPX 88D BASE REF LOOP DOES SHOW SOME OF  
THE MID LEVEL MOISTURE ASSOCIATED WITH THIS REACHING INTO OUR  
SOUTHERN CWA...RESULTING IN ONLY SOME SCATTERED FLURRIES/VERY  
LIGHT SNOW SHOWERS ACROSS OUR SW CWA. SOME LINGERING LIGHT  
NORTHERLY FLOW LAKE EFFECT FLURRIES/LIGHT SNOW SHOWERS ARE STILL  
STREAMING INTO THE GRAND TRAVERSE AREA AS WELL.  
 
AS WE HEAD INTO THE OVERNIGHT HOURS...LOW LEVEL FLOW WILL  
GRADUALLY SHIFT TO THE NE...REFOCUSING LAKE SNOW SHOWERS INTO NE  
LOWER MICHIGAN OFF OF LAKE HURON. SMALL CHANCES OF LIGHT SNOW WILL  
CONTINUE ACROSS OUR FAR SOUTHERN CWA AS WELL AS THE FAR NORTHERN  
FRINGE OF THAT MOISTURE SHIELD JUST SKIRTS TO OUR SOUTH. ALL IN  
ALL...EXPECT LITTLE TO NO NEW SNOW ACCUMULATION OVERNIGHT. TEMPS  
WILL BE QUITE COLD...ESPECIALLY ACROSS EASTERN UPPER MICHIGAN  
WHERE SKIES ARE EXPECTED TO CLEAR OUT THANKS TO DRY NE DRAINAGE  
FLOW. OVERNIGHT LOWS WILL BE MAINLY IN THE SINGLE DIGITS ABOVE AND  
BELOW ZERO...AND WILL LIKELY DROP INTO THE TEENS BELOW ZERO ACROSS  
FAR EASTERN UPPER MICHIGAN FOR A FEW HOURS VERY LATE TONIGHT. STAY  
WARM EVERYONE!  
 

 
   
NEAR TERM
 
(THROUGH TONIGHT)  
ISSUED AT 308 PM EST FRI JAN 18 2019  
   
..TEMPERATURES TRENDING DOWNWARD
 
 
HIGH IMPACT WEATHER POTENTIAL: MINIMAL, ALTHOUGH TEMPERATURE AND  
WIND CHILL READINGS WILL BE WELL BELOW ZERO TONIGHT, ESPECIALLY  
ACROSS EASTERN UPPER MICHIGAN.  
 
PATTERN SYNOPSIS/FORECAST: STEP-DOWN PROCESS TO A MUCH COLDER  
WEATHER REGIME NOW WELL UNDERWAY AS ARCTIC HIGH PRESSURE BUILDS  
ACROSS THE NORTHERN GREAT LAKES AND SOUTHERN CANADA. MID AND UPPER  
LEVEL FLOW ONLY HELPING THE COOLING CAUSE, WITH NORTHERN MICHIGAN ON  
THE SOUTHERN EXTENT OF A VERY DEEP NORTHEAST CANADA CENTERED TROUGH  
AXIS. SPLIT FLOW DOMINATES THE REST OF THE CONUS, WITH A SHARP  
SHORTWAVE TROUGH EMBEDDED WITHIN A MUCH MORE ACTIVE SOUTHERN STREAM  
FLOW REGIME ACROSS THE SOUTHERN PLAINS INTO THE SOUTHEAST STATES.  
THIS SOUTHERN WAVE, COUPLED WITH A MUCH MORE SUBTLE NORTHERN STREAM  
POCKET OF ENERGY DIGGING ACROSS THE NORTHERN PLAINS, IS KICKING OFF  
A BROAD AREA OF SNOW ACROSS THE NORTHERN AND MID MISSISSIPPI VALLEY.  
MUCH LESS ACTIVE ACROSS OUR AREA, WITH JUST SOME LIGHT LAKE DRIVEN  
SNOWS IN A SLOWLY VEERING BOUNDARY LAYER FLOW PATTERN. COLD AIR  
ADVECTION HAS OFFSET THE ALREADY MUTED JANUARY DIURNAL TEMPERATURE  
CYCLE, RESULTING IN TEMPERATURES FALLING THIS MORNING AND EARLY  
AFTERNOON, WITH READINGS ALREADY DROPPING INTO THE UPPER SINGLE  
DIGITS AND LOWER TEENS ACROSS EASTERN UPPER MICHIGAN.  
 
UPSTREAM WAVES EVENTUALLY CONGEAL, DRIVING A RATHER SIGNIFICANT  
WINTER STORM ACROSS THE SOUTHERN GREAT LAKES AND OHIO VALLEY LATER  
TONIGHT INTO SATURDAY. PROXIMITY OF STRONG HIGH PRESSURE AND  
PERSISTENT DRY NORTHEAST FLOW WILL HELP KEEP MUCH OF THE WIDESPREAD  
SNOW WELL OFF TO OUR SOUTH, ALTHOUGH NORTHERN EXTENT OF SNOW SHIELD  
AND A WEAK LAKE RESPONSE WILL BRING THE THREAT FOR A LITTLE SNOW TO  
AT LEAST PARTS OF OUR AREA TONIGHT.  
 
PRIMARY FORECAST CONCERNS/CHALLENGES: JUST HOW COLD TO GO ACROSS  
EASTERN UPPER MICHIGAN AND ADDRESSING THOSE LIGHT SNOW CONCERNS.  
 
DETAILS: BOUNDARY LAYER FLOW CONTINUES TO VEER TO A NORTHEAST  
DIRECTION TONIGHT AS LOW PRESSURE FURTHER MATURES AS IT PASSES  
ACROSS ARKANSAS. THIS SHOULD BRING LAKE EFFECT SNOW SHOWERS INTO  
NORTHEAST LOWER MICHIGAN WITH TIME. SNOW SHOWER INTENSITY AND  
ORGANIZATION WILL BE SEVERELY HAMPERED BY AN SUB 5KFT CONVECTIVE  
CLOUD DEPTH AND EXTREMELY DRY AIR ROTATING OUT OF CANADA. IN  
ADDITION, MAY SEE THE NORTHERN AND MUCH LESS INTENSE FRINGE OF THAT  
OHIO VALLEY WINTER STORM CLIP AREAS DOWN NEAR M-55, BRINGING THE  
THREAT FOR SOME VERY LIGHT SNOW TO THOSE AREAS BY LATER TONIGHT. ALL  
TOLD, LOOKING AT JUST MINIMAL SNOW ACCUMULATIONS TONIGHT, LIKELY  
REMAINING WELL UNDER AN INCH EVEN UNDER THE MOST PERSISTENT SNOW  
SHOWER ACTIVITY.  
 
PERHAPS FAR BIGGER STORY WILL BE THOSE FALLING TEMPERATURES AS COLD  
AIR ADVECTION ONLY RAMPS UP WITH TIME. CLOUDS WILL DO THEIR BEST TO  
KEEP READING IN-CHECK FOR AREAS SOUTH OF THE BIG BRIDGE, WITH  
TEMPERATURES BY MORNING DROPPING INTO THE SINGLE DIGITS ABOVE AND  
BELOW ZERO ACROSS INTERIOR AREAS. UNFORTUNATELY, NORTHEAST WINDS ARE  
IDEAL TO BRING VERY COLD TEMPERATURES INTO EASTERN UPPER MICHIGAN AS  
THEY HELP SCOUR OUT THE LOW LEVEL OVERCAST. FULLY EXPECT  
TEMPERATURES TO DROP INTO THE LOWER NEGATIVE TEENS, WITH THE COLDEST  
READINGS ACROSS NORTHEAST CHIPPEWA COUNTY, INCLUDING SAULT STE  
MARIE. COUPLE THOSE TEMPERATURES WITH SOME LIGHT WINDS, AND WIND  
CHILL READINGS WILL LIKELY DIP BELOW -20 DEGREES BY EARLY SATURDAY  
MORNING. JUST SHORT OF HEADLINE WORTHY, BUT VERY COLD NONETHELESS.  
 

 
   
SHORT TERM
 
(SATURDAY THROUGH MONDAY)  
ISSUED AT 308 PM EST FRI JAN 18 2019  
   
..THE COLDEST AIR OF THE SEASON
 
 
HIGH IMPACT WEATHER POTENTIAL...LAKE ENHANCED SNOW AS THE STORM TO  
THE SOUTH PULLS DOWN COLD AIR. ALSO, THE COLD AIR WILL BE THE  
COLDEST OF THE SEASON...SO FAR.  
 
PATTERN SYNOPSIS/FORECAST...S PLAINS LOW MOVES INTO THE  
SOUTHERN/CENTRAL APPALACHIAN MOUNTAINS, AS A DECENT 500 MB TROUGH  
BEGINS TO SWING INTO THE UPPER GREAT LAKES. THIS LEADS TO THE NORTH  
TO NNE LAKE ENHANCEMENT WITH THE SNOW THAT IS FALLING IN CONJUNCTION  
WITH THE STORM SYSTEM THAT LOOKS TO FALL SOUTH AND EAST OF A PZQ TO  
CAD LINE. SATURDAY NIGHT, THE LAKE ENHANCEMENT ALONG LAKE MICHIGAN  
DIMINISHES, WHILE THE LAKE EFFECT CONTINUES ALONG THE LAKE HURON  
SHORELINE, UNTIL SUNDAY MORNING. AS THE 500 MB TROUGH AXIS BEGINS TO  
SWING THROUGH THE FORECAST AREA SUNDAY, THE SNOW ALONG LAKE MICHIGAN  
AND NW LOWER/E UPPER BEGINS TO GET BETTER FOR A TIME. THEN  
DIMINISHING SUNDAY NIGHT AS THE DRY AIR FROM THE SFC HIGH TO THE  
NORTHEAST OF THE FORECAST PUSHES INTO THE REGION. THIS WILL PRODUCE  
SOME OF THE COLDEST TEMPERATURES OF THE SEASON SO FAR AS WE GO INTO  
MONDAY MORNING.  
 
PRIMARY FORECAST CONCERNS...THE LAKE EFFECT/ENHANCEMENT HAS SOME  
ISSUES WITH IT. ONE IS THE TEMPERATURES AT 850 MB THROUGH THIS TIME  
PERIOD. SUNDAY AFTERNOON, THE 850 MB TEMPERATURES OVER THE UPPER  
GREAT LAKES IS -25C OR COLDER. THIS MAKES FOR SMALL SNOW FLAKES OVER  
THE REGION, WHICH COULD A MAJOR ISSUE WITH THE VISIBILITY. ALSO, THE  
AMOUNTS, WHICH COULD BE LIGHT TO MODERATE.  
 
WITH THESE COLD 850 MB TEMPERATURES, CAUSES ISSUES OF DOUBLE DIGIT  
BELOW ZERO SFC MINS FOR SUNDAY AND MONDAY, AND WITH THE WIND  
EXPECTED COULD PRODUCE ADVISORY WIND CHILLS IN E UPPER. HYPOTHERMIA  
AND FROSTBITE ARE ISSUES THAT WILL NEED TO BE ADDRESSED.  
   
LONG TERM
 
(MONDAY NIGHT THROUGH FRIDAY)  
ISSUED AT 308 PM EST FRI JAN 18 2019  
 
HIGH IMPACT WEATHER POTENTIAL...A STORM SYSTEM THAT LOOKS TO IMPACT  
THE REGION MONDAY NIGHT THROUGH TUESDAY NIGHT, WITH LAKE EFFECT INTO  
WEDNESDAY.  
 
EXTENDED...HIGH PRESSURE LENDS TO WARMING TEMPERATURES AS SW  
WINDS AND SUNNY SKIES, MONDAY. HOWEVER, MONDAY NIGHT, THE WARM  
FRONT TO THE NEXT SFC LOW MOVES IN AND SNOW BEGINS BY 12Z/TUE.  
THERE ARE STILL SOME TRACK ISSUES FOR TUESDAY AS THE SYSTEM MOVES  
THROUGH LOWER MICHIGAN, BUT N LOWER LOOKS TO HAVE SOME  
ACCUMULATING SNOW AND MAYBE SOME MIXED PRECIPITATION SOUTH OF  
M-72. THEN THE HEAVIER PRECIPITATION MOVES EAST, AND LES IS ON THE  
BACKSIDE OF THE LOW AS WE GO INTO WEDNESDAY. THE SNOW DIMINISHES  
WEDNESDAY NIGHT, BEFORE A CLIPPER SYSTEM MOVES IN THURSDAY.  
FRIDAY, THE UPCOMING COLD AIR WHICH IF THE ECMWF IS RIGHT WOULD BE  
EVEN COLDER AND COULD KICK OFF THE UPCOMING BELOW NORMAL  
TEMPERATURES FOR FEBRUARY.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)  
ISSUED AT 545 PM EST FRI JAN 18 2019  
 
LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO FALL ACROSS PORTIONS OF  
NORTHERN LOWER MICHIGAN THRU TONIGHT...WITH SOME SYNOPTIC  
ENHANCEMENT DEVELOPING LATER TONIGHT AS THE NORTHERN EDGE OF  
MOISTURE FROM A SYSTEM TRACK SOUTH OF OUR AREA PUSHES INTO OUR  
REGION. LOW LEVEL WINDS WILL SHIFT TO THE NE LATER TONIGHT AND  
SATURDAY...SHIFTING FOCUS OF LIGHT LAKE EFFECT SNOW SHOWERS TO NE  
LOWER MICHIGAN. OVERALL CONDITIONS WILL REMAIN VFR/MVFR THRU THE  
FORECAST PERIOD.  
 

 
   
MARINE
 
 
ISSUED AT 308 PM EST FRI JAN 18 2019  
 
HIGH PRESSURE WILL EXTEND FROM CENTRAL CANADA INTO ONTARIO  
AND QUEBEC THROUGH THE WEEKEND, WHILE LOW PRESSURE DEEPENS AS IT  
MOVES ACROSS THE OHIO VALLY TO THE ATLANTIC COAST. THERE WILL BE  
VARIOUS TIMES FOR LOW END ADVISORY WIND SPEEDS THROUGH THIS WEEKEND,  
AS WELL AS SCATTERED LIGHT LAKE EFFECT SNOW AND FLURRIES.  
 

 
   
APX WATCHES/WARNINGS/ADVISORIES
 
 
MI...NONE.  
LH...NONE.  
LM...NONE.  

 
 

 
 
UPDATE...MR  
NEAR TERM...MB  
SHORT TERM...JL  
LONG TERM...JL  
AVIATION...MR  
MARINE...MB  
 
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