973  
FXUS63 KAPX 300350  
AFDAPX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GAYLORD MI  
1150 PM EDT THU SEP 29 2016  
   
UPDATE
 
 
ISSUED AT 1042 PM EDT THU SEP 29 2016  
 
PESKY, DEEP UPPER LOW CONTINUES TO SPIN OVER THE OHIO VALLEY WITH  
THE CENTER OF CIRCULATION OVER KENTUCKY. BANDS OF SHOWERS CONTINUE  
TO ROTATE AROUND THIS FEATURE, THROUGH OHIO AND SOUTHERN LOWER  
MICHIGAN, AND THE OCCASIONAL SPOTTY SHOWERS GETTING UP INTO PARTS  
OF NORTHERN LOWER MICHIGAN. BUT, DEEP NORTHEASTERLY DRY FLOW  
CONTINUES TO MAINTAIN OVERALL DRY CONDITIONS FOR MUCH OF NORTHERN  
MICHIGAN AND A SHARP CLEARING LINE FROM THE TIP OF THE MITT INTO  
EASTERN UPPER MICHIGAN.  
 
REST OF TONIGHT: PRETTY MUCH STATUS QUO AS DEEP CIRCULATION MOVES  
VERY LITTLE. THERE IS ANOTHER BATCH OF QG-FORCING AND SURGE OF  
MOISTURE/PRECIP ROTATING UP THROUGH NE OHIO THAT WILL SLIDE UP  
THROUGH SE LOWER MICHIGAN OVERNIGHT AND MAY SKIRT THE FAR  
SOUTHERN/SOUTHEAST COUNTIES OF THIS CWA TOWARD MORNING. BUT UNTIL  
THEN, NOT MUCH ANTICIPATED OTHER THAN SOME LOWER CLOUD COVER  
STREAMING OFF LAKE HURON INTO PARTS OF NE LOWER AND SPOTTY RADAR  
RETURNS.  
 

 
   
SHORT TERM
 
(THIS EVENING AND OVERNIGHT)  
ISSUED AT 312 PM EDT THU SEP 29 2016  
 
UPPER LEVEL LOW THAT HAS PLAGUED GREAT LAKES WEATHER FOR THE LAST  
FEW DAYS CONTINUES TO SIT AND SPINS ACROSS THE LOWER OHIO VALLEY  
THIS AFTERNOON. DEEP ATLANTIC MOISTURE FEED WITHIN WARM CONVEYOR  
BELT OF THIS SYSTEM BRINGING SOME DECENT RAINS TO OUR NEIGHBORS TO  
OUR SOUTH, WITH RAINFALL AMOUNTS THIS MORNING IN EXCESS OF 3 INCHES  
FOR PARTS OF SOUTHEAST MICHIGAN. UP THIS WAY, DEEP NORTHEAST FLOW  
CONTINUES TO BRING IN PLENTY OF LOWER LEVEL DRY AIR, WHICH HAS  
GREATLY HINDERED ANY NORTHWARD ADVANCE OF THAT SOUTHERN MICHIGAN  
RAIN SHIELD (AND BROUGHT SUN-FILLED SKIES TO EASTERN UPPER  
MICHIGAN). BASED OFF SIMPLE RADAR EXTRAPOLATION, IT DOES LOOK LIKE A  
FEW LIGHT SHOWERS WILL IMPACT AREAS DOWN CLOSER TO SAGINAW BAY YET  
THIS AFTERNOON.  
 
DIFFICULT RAIN FORECAST HEADING THROUGH TONIGHT AND FRIDAY AS THAT  
UPPER LEVEL SYSTEM ONLY MAKES SLOW PROGRESS BACK NORTH. THAT  
ATLANTIC MOISTURE PLUME ATTEMPTS TO DO THE SAME, ALTHOUGH PERSISTENT  
DRY NORTHEAST FLOW WILL HAVE PLENTY TO SAY ON JUST HOW FAR NORTH IT  
ADVANCES. PRETTY STOUT H8-H7 THETA-E ADVECTION DOES OCCUR OVERNIGHT  
INTO FRIDAY OVER NORTHERN LOWER, ALTHOUGH BETTER FORCING PER PASSING  
VORT LOBES ROTATING AROUND PARENT SYSTEM LARGELY REMAINS OFF TO OUR  
SOUTH. GIVEN TRENDS/SIMPLE PERSISTENCE, GOTTA BELIEVE THE BETTER  
RAINS STAY TO OUR SOUTH FOR THE NEXT 24 HOURS OR SO, WAITING TO MAKE  
A MORE DEFINITIVE NORTHWARD SHIFT FRIDAY NIGHT. STILL DO BELIEVE  
SOME LIGHTER ACTIVITY WILL SLIDE INTO PARTS OF NORTHERN LOWER  
TONIGHT AND FRIDAY, ESPECIALLY ALONG AND SOUTH OF THE M-55 CORRIDOR.  
WILL TREND INHERITED POPS ACCORDINGLY, WITH A RATHER SHARP SOUTH TO  
NORTH DELINEATION. NOW, WITH ALL THAT SAID, THIS WILL HAVE TO BE  
CLOSELY MONITORIED, AS RAINFALL RATES COULD BE LOCALLY HEAVY WITH  
EFFICIENT RAIN PROCESSES AND DEFINITE HINTS OF TRAINING SHOWER  
ACTIVITY (SEE DETROIT THIS MORNING). CURRENT THOUGHT IS THIS HEAVIER  
RAIN AXIS WILL REMAIN JUST OFF TO OUR SOUTH.  
   
LONG TERM
 
(FRIDAY THROUGH THURSDAY)  
ISSUED AT 312 PM EDT THU SEP 29 2016  
 
SYNOPTIC PATTERN: VERTICALLY STACKED UPPER LOW OVER THE OHIO VALLEY  
WILL MEANDER ITS WAY NORTHWARD THROUGH SOUTHERN MICHIGAN THIS  
WEEKEND UNDER THE INFLUENCE OF INCREASING WESTERLIES. THIS WILL  
RESULT IN A RATHER CLOUDY AND UNSETTLED WEEKEND, WITH PERIODIC RAIN  
CHANCES.  
 
MODEL GUIDANCE IN VERY GOOD AGREEMENT FRIDAY NIGHT THROUGH THE  
WEEKEND IN LIFTING UPPER LOW NORTHWARD INTO MICHIGAN. THE  
CHALLENGING PART OF THE FORECAST IS IN THE DETAILS OF PRECIPITATION  
ASSOCIATED WITH CIRCULATION CENTER, AS MODELS CONTINUE TO STRUGGLE  
TO RESOLVE EMBEDDED SHORTWAVES. MOST WIDESPREAD RAIN POTENTIAL  
FRIDAY NIGHT SHOULD BE ACROSS THE SOUTHERN HALF OF THE AREA (MAINLY  
SOUTH OF M-55) WITHIN H8-H7 THETA-E AXIS, WITH LESSER RAIN THE  
FURTHER THE NORTH YOU GO WHERE THE INFLUENCE OF DRY EASTERLY FLOW  
WILL BE GREATER.  
 
PLENTY OF QUESTION MARKS FOR THE WEEKEND WITH REGARD TO HOW WET  
THINGS WILL BE. 850MB THETA-E RIDGE SHIFTS NORTH THROUGH THE  
WEEKEND, BUT IS NOT NECESSARILY REFLECTED IN THE MODEL QPF.  
CERTAINLY SOME SHOWERS AROUND ON SATURDAY, ALTHOUGH WONDER WHETHER  
DRIER EAST FLOW WILL CONTINUE TO INFLUENCE THE COVERAGE OF  
PRECIPITATION. DEEPER MOISTURE (H8-H5) PUSHES NORTHWARD INTO MORE  
OF THE AREA LATER SATURDAY NIGHT INTO SUNDAY AS SURFACE/UPPER  
FEATURE MOVES TOWARD THE THUMB REGION. THIS MAY BRING A BETTER  
CHANCE OF RAIN TO MORE OF THE AREA - ALTHOUGH CONFIDENCE IS NOT THAT  
HIGH. TEMPERATURES NEAR SEASONABLE LEVELS, WITH HIGHS GENERALLY IN  
THE 60S.  
 
JK  
 
MONDAY THROUGH THURSDAY...WILL CONTINUE WITH WELL ABOVE NORMAL  
TEMPERATURES ALONG WITH MAINLY DRY CONDITIONS THROUGH THE PERIOD.  
 
AT UPPER LVLS...A NEARLY CUTOFF UPPER LOW OVER THE ERN LAKES SUNDAY  
NIGHT WILL EXIT EAST MONDAY...WHILE A SECOND UPPER LOW ORGANIZES AND  
DIGS INTO THE WEST COAST. A 500MB UPPER RIDGE WILL INCREASE ACROSS  
THE GREAT LAKES AND OHIO VALLEY THROUGH MIDWEEK...AS THE WEST COAST  
UPPER LOW PUSHES INTO THE PLAINS. MID LVL TEMPS IN THIS PATTERN...  
SHOW 850MB TEMPS AROUND 8C THROUGH TUESDAY...WARMING TO AROUND 12C  
WEDNESDAY AND THURSDAY. THIS PATTERN WILL CONTINUE ABOVE NORMAL  
TEMPERATURES ACROSS NORTHERN MICHIGAN THROUGH THE PERIOD...WARMING  
FROM THE MID 60S MONDAY TO THE LOWER 70S BY WEDNESDAY.  
 
AT THE SURFACE...AN AREA OF HIGH PRESSURE CENTERED NEAR HUDSON BAY  
TO BEGIN THE WEEK WILL SLOWLY SINK SOUTH INTO THE NORTH ATLANTIC BY  
MID-WEEK...WHILE A SYSTEM OVER THE ROCKIES MONDAY BECOMES BETTER  
ORGANIZED AND LIFTS INTO THE WRN GREAT LAKES THURSDAY. THIS PATTERN  
WILL GENERATE SOME SUN AND MAINLY DRY CONDS OVER NRN MI THROUGH  
MIDWEEK...WHILE THE CHANCE OF RAIN SHOWERS INCREASES SLIGHTLY  
THURSDAY.  
 
SWR  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)  
ISSUED AT 1150 PM EDT THU SEP 29 2016  
 
DEEP UPPER LOW CONTINUES TO SPIN OVER THE OHIO VALLEY, CENTERED  
OVER KENTUCKY, WITH BANDS OF SHOWERS CONTINUING TO ROTATE THROUGH  
THE LOWER LAKES REGION. THIS SYSTEM WILL SLOWLY LIFT BACK  
NORTHWARD INTO THE STATE OVER THE NEXT FEW DAYS AND EVENTUALLY  
BRING SEVERAL ROUNDS OF SHOWERS BACK INTO NORTHERN MICHIGAN HEADING  
INTO THE WEEKEND.  
 
MVFR CLOUD COVER AND SHOWERS WILL SPREAD NORTHWARD INTO THE  
REGION THROUGH FRIDAY, IMPACTING MAINLY TVC/MBL. PLN AND APN MAY  
REMAIN JUST ON THE NORTHERN FRINGE OF THE LOWER CLOUD COVER AND  
SHOWERS.  
 
WINDS, GUSTIER NE WINDS WILL PERSIST THROUGH FRIDAY.  
 

 
   
MARINE
 
 
ISSUED AT 312 PM EDT THU SEP 29 2016  
 
GUSTY NORTHEAST WINDS AND CHOPPY WAVES TO CONTINUE ACROSS  
MUCH OF LAKE MICHIGAN AND LAKE HURON THROUGH FRIDAY EVENING.  
NORTHEAST WINDS WILL BEGIN TO SUBSIDE SOME HEADING THROUGH LATER  
FRIDAY NIGHT ON INTO THE START OF THE WEEKEND. ALL INHERITED  
ADVISORIES WILL REMAIN.  
 

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

 
 

 
 
UPDATE...ADAM  
SHORT TERM...MSB  
LONG TERM...SWR/KEYSOR  
AVIATION...ADAM  
MARINE...MSB  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab MI Page Main Text Page