371  
FXUS63 KAPX 280704  
AFDAPX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GAYLORD MI  
304 AM EDT MON JUL 28 2014  
   
SYNOPSIS
 
 
ISSUED AT 303 AM EDT MON JUL 28 2014  
 
LOW PRESSURE IN THE EASTERN GREAT LAKES WILL MOVE EAST AND THEN  
NORTH...REACHING NORTHERN QUEBEC ON WEDNESDAY. WE WILL REMAIN IN THE  
BACKWASH OF THIS SYSTEM ALL WEEK...KEEPING OUR WEATHER ON THE COOL  
SIDE...AND PROVIDING US WITH OCCASIONAL CHANCES FOR SHOWERS.  
 

 
   
SHORT TERM
 
(TODAY THROUGH TONIGHT)  
ISSUED AT 303 AM EDT MON JUL 28 2014  
   
..ANOTHER TOUCH OF EARLY FALL-LIKE WEATHER
 
 
HIGH IMPACT WEATHER POTENTIAL: MINIMAL. WHAT THERE ARE CENTER ON  
MARINE SCA HEADLINES.  
 
PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: STRONG CAA WELL UNDERWAY  
ACROSS THE NORTH WOODS AT THIS EARLY HOUR...COURTESY OF DEEP NORTH  
FLOW ON BACKSIDE OF VIGOROUS EASTERN LAKES SHORTWAVE. SYSTEM ITSELF  
HELPING ESTABLISH ANOMALOUSLY DEEP OVERHEAD TROUGHING...THE CENTER OF  
WHICH IS LARGE GYRE SPINNING ACROSS CENTRAL QUEBEC. SHOWERS AND  
STORMS OF YESTERDAY NOW A THING OF THE PAST...WITH SAID CAA ALSO  
ACCOMPANIED BY RATHER STOUT DRY AIR ADVECTION (AS IT OFTEN IS).  
TROUGHING...HOWEVER...REMAINS UNSETTLED...WITH ANOTHER SLUG OF  
DEEPER MOISTURE TIED TO WEAK IMPULSE MAKING STEADY SOUTH PROGRESS  
ACROSS NORTHERN ONTARIO. LARGER SCALE PATTERN EXPECTED TO CHANGE  
LITTLE OVER THE NEXT 24 HOURS...SETTING THE STAGE FOR ANOTHER BOUT  
OF MID SUMMER CHILL TODAY AND TONIGHT...ALONG WITH SOME LATE NIGHT  
LIGHT RAIN CONCERNS AS UPSTREAM MOISTURE AXIS DROPS FURTHER SOUTH.  
 
PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE AND CLOUD TRENDS  
THROUGHOUT. ACCESSING RAIN CHANCES VERY LATE TONIGHT.  
 
DETAILS: WELL...AFTER DAYS OF TALKING ABOUT IT...ANOTHER BOUT OF  
EARLY FALL-LIKE CHILL HAS ARRIVED. CAA EXPECTED TO CONTINUE RIGHT  
THROUGH THIS MORNING AND EARLY AFTERNOON...WITH H8 TEMPERATURES  
BOTTOMING OUT IN THE MID SINGLE DIGITS. DIURNAL RESPONSE WILL TRY  
ITS BEST TO OFFSET...BUT SIMPLE LOW LEVEL THERMAL PROFILES SUPPORT  
HIGHS ONLY REACHING THE MID AND UPPER 60S. THESE ARE A GOOD 10 TO 15  
DEGREES BELOW NORMAL! INCREASINGLY GUSTY WINDS WILL ONLY ADD TO THE  
CHILL...WITH DEEPENING MIXED LAYER SUPPORTING WIND GUSTS OF 20 TO 25  
MPH. GOOD NEWS IS IT SHOULD BE A DRY DAY...WITH STRONG CAP UP NEAR  
H7 AND DRY LOW LEVELS. NO DOUBT SOME DIURNALLY DRIVEN CU WILL  
FORM...BUT THESE LOOK TO REMAIN SHALLOW-TOPPED AND SHOWER FREE.  
 
MOISTURE CONTINUES TO INCREASE FROM THE NORTH HEADING THROUGH  
TONIGHT AS SUBTLE WAVE PULLS INTO THE NORTHERN LAKES. TRENDS HAVE  
BEEN A TOUCH MORE AGGRESSIVE WITH INCREASING CLOUDS...WHICH HAS SOME  
MERIT GIVEN CURRENT VFR BROKEN/OVERCAST CONDITIONS MOVING ACROSS  
NORTHWEST ONTARIO. WILL TREND TOWARD THIS MORE AGGRESSIVE  
DIRECTION...ALTHOUGH NOT GOING QUITE AS CLOUDY AS MOST GUIDANCE  
WOULD SUGGEST. CANNOT COMPLETELY RULE OUT A LATE NIGHT SPRINKLE  
ACROSS THE NORTH...BUT SUCH LOW POTENTIAL ON WHAT WOULD BE A TRIVIAL  
EVENT JUST NOT WORTHY OF A SPECIFIC MENTION IN THE  
FORECAST.  
 

 
   
LONG TERM
 
(TUESDAY THROUGH SUNDAY)  
ISSUED AT 303 AM EDT MON JUL 28 2014  
   
..MUCH COOLER THAN NORMAL TO CLOSE OUT JULY
 
 
THE UPPER LOW IN CENTRAL QUEBEC WILL TEND TO RETROGRADE SLIGHTLY...  
AS IT FULLY ABSORBS THE UPPER LOW THAT GAVE US SUCH AN EXCITING DAY  
YESTERDAY. THE SYSTEM WILL BACK UP TO THE VICINITY OF JAMES BAY BY  
THURSDAY MORNING. AT THE SURFACE...BROAD BUT WEAK NW-ERLY FLOW WILL  
BE IN PLACE. THERE TENDS TO BE SOME WEAK TROFFING IN PLACE OVER  
NORTHERN MI TUESDAY...WHICH IS DISPLACED DOWNSTATE BY WEDNESDAY.  
TEMP TRENDS AND SMALL PRECIP CHANCES THE MAIN CONCERNS.  
 
TUESDAY...A VORT MAX ROTATING AROUND THE LARGE LOW IS PROGGED TO  
PIVOT FROM NORTH OF SUPERIOR TO FAR NORTHERN LOWER MI. DEEP  
CYCLONICALLY-CURVED FLOW WILL ASSIST THIS VORT IN PRODUCING A RATHER  
LARGE MOISTURE PLUME (850-500MB RH MAINLY 75-80 PERCENT). THE  
CONTINUED STEEP-ISH LAPSE RATES (700-500MB 6-6.5 C/KM) WILL HELP  
SUPPORT 100-300J/KG OF MUCAPE...EVEN IN THE MORNING. DIURNAL HEATING  
WILL BOOST THOSE NUMBERS TO 500-700J/KG IN THE AFTERNOON...JUST IN  
TIME FOR SOME ACTUAL FORCING. SO POPS NEEDED IN MOST AREAS MOST OF  
THE DAY...BUT WILL BE HIGHEST IN THE AFTERNOON IN N CENTRAL AND NE  
LOWER MI. LAKES MI AND SUPERIOR WILL ATTEMPT TO PROVIDE SMALLISH  
RAIN SHADOWS.  
 
WILL REDUCE (THOUGH NOT ELIMINATE) POPS IN THE MORNING...AND REMOVE  
AM THUNDER. WILL BOOST NE LOWER TO LIKELY POPS IN THE AFTERNOON.  
SMALL HAIL COULD BE RELATIVELY COMMON IN THE AFTERNOON GIVEN THE  
CHILLY TEMPS ALOFT.  
 
MAX TEMPS MAINLY UPPER 60S TO AROUND 70F.  
 
TUE NIGHT/WED...SHRA THREAT MAY LINGER INTO TUESDAY EVENING IN SE  
SECTIONS...BEFORE EXITING OVERNIGHT. ALSO...LEFTOVER SHRA FROM FAR  
NORTHERN ONTARIO MAY BE ABLE TO SUSTAIN THEMSELVES FOR A WHILE IN  
THE STEEP LAPSE RATE ENVIRONMENT. SOME REMNANTS OF THESE COULD  
CONCEIVABLY POKE INTO EASTERN UPPER OVERNIGHT...THOUGH FOR NOW WILL  
NOT MENTION. ON WEDNESDAY...THE BIG BALL OF WRAPAROUND MOISTURE FROM  
THE UPPER LOW WILL BE JUST SKIRTING BE N AND E OF THE FORECAST AREA.  
POPS DO NOT NEED TO BE AS HIGH AS ON TUESDAY...BUT THEY DO APPEAR  
NEEDED THRU THE DAY IN EASTERN UPPER...CLOSEST TO THAT CHILLY LOW TO  
THE NNE. ALSO KEPT SOME PM POPS IN FAR SE SECTIONS...FURTHEST AWAY  
FORM LAKE SHADOWING IN AN AIRMASS THAT IS OTHERWISE NOT ESPECIALLY  
MOIST.  
 
MIN TEMPS UPPER 40S TO LOWER 50S. MAX TEMPS MAINLY WITHIN A FEW  
DEGREES OF 70F.  
 
REST OF THE FORECAST...THE UPPER LOW TO OUR NE FINALLY EJECTS FRIDAY  
AND BEYOND...THOUGH A RATHER SHARP TROF CONTINUES TO LINGER BACK  
ACROSS THE LAKES REGION (OF COURSE IT DOES). THAT SHOULD ALLOW TEMPS  
TO SLOWLY MODERATE...THOUGH IT WILL TAKE A WHILE FOR US TO APPROACH  
NORMAL. AND THAT DOES LEAVE US WITH A PLEASANT ENOUGH WEEKEND AHEAD.  
 
AS FOR PRECIP...STAYING BENEATH TROFFING ALOFT POTENTIALLY KEEPS THE  
DOOR OPEN FOR DIURNAL PRECIP. THIS MAY GET SOME SYNOPTIC ASSISTANCE  
ON FRIDAY...WHEN EVEN AS THE UPPER LOW STARTS TO EXIT...THE TRAILING  
TROF MAKES A BIT OF A PUSH INTO THE REGION FROM THE NW.  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)  
ISSUED AT 118 AM EDT MON JUL 28 2014  
 
SCT/BKN LOW VFR CIGS ARE EXPECTED ACROSS NRN LWR MICHIGAN THROUGH  
MONDAY NIGHT...WITH VFR VSBYS THRU THE TAF FORECAST PERIOD. NORTH  
WINDS GUSTING TO 15 TO 25 KTS SHOULD PRECLUDE FOG DEVELOPMENT  
OVERNIGHT. GUSTY NORTH WINDS WILL CONTINUE THRU THE DAY AND EARLY  
EVENING...AND THEN DIMINISH WITH SUNSET.  
 

 
   
MARINE
 
 
ISSUED AT 303 AM EDT MON JUL 28 2014  
 
NORTH WINDS WILL GRADUALLY BACK AROUND TO NORTHWEST  
TODAY...BECOMING MORE WESTERLY BY TUESDAY. GUSTY CONDITIONS WILL  
CONTINUE...WITH SPEEDS SLOWLY SUBSIDING FROM WEST TO EAST TODAY INTO  
THE OVERNIGHT. SCA CONDITIONS WILL CONTINUE TODAY ACROSS MUCH OF  
LAKE MICHIGAN AND HURON...WITH SCA CONDITIONS LIKELY CONTINUING  
THROUGH MUCH OF THE OVERNIGHT OFFSHORE OF NORTHEAST LOWER MICHIGAN.  
WINDS AND WAVES LOOK TO LARGELY REMAIN BELOW HEADLINE CRITERIA  
TUESDAY THROUGH THE REMAINDER OF THE WEEK.  
 

 
   
APX WATCHES/WARNINGS/ADVISORIES
 
 
MI...NONE.  
LH...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LHZ347>349.  
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ323-  
342-344>346.  
LS...NONE.  
 

 
 

 
 
SYNOPSIS...JZ  
SHORT TERM...MSB  
LONG TERM...JZ  
AVIATION...MR  
MARINE...MSB  
 
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