897  
FXUS63 KDTX 281051  
AFDDTX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI  
651 AM EDT TUE MAR 28 2017  
 
   
AVIATION
 
 
ONGOING SHALLOW COLD AIR ADVECTION WITHIN A MOIST LOW LEVEL  
ENVIRONMENT HAS LED TO WIDESPREAD IFR STRATUS WITH SOME LIFR/VLIFR  
CIGS AS WELL. SOME SUBTLE LOW LEVEL DRYING AND COLD AIR ADVECTION  
ALONG WITH DAYTIME HEATING WILL GRADUALLY LIFT THE CLOUD BASES TO  
MVFR, LIKELY LATE THIS MORNING OR EARLY AFTERNOON. THERE WILL BE A  
PUSH OF DRIER AIR FROM THE NORTH LATER IN THE DAY THAT WILL ERODE  
THE STRATUS DECK DURING THE EVENING.  
 
FOR DTW...THE GRADIENT WILL SUPPORT A STEADY NORTH-NORTHEAST WIND  
DURING THE ENTIRE DAY. BOUNDARY LAYER GROWTH DUE TO DAYTIME MIXING  
WILL SUSTAIN THE WIND SPEEDS AROUND 10 KNOTS. TIMING OF THE LIFTING  
OF CLOUD BASES TO MVFR CARRIES SOME DEGREE OF UNCERTAINTY, BUT  
SHOULD OCCUR SOMETIME BETWEEN 15Z AND 17Z.  
 
//DTW THRESHOLD PROBABILITIES...  
 
* HIGH FOR CIGS BELOW 5000 FEET THIS MORNING THROUGH MID EVENING.  
 

 
   
PREV DISCUSSION
 
 
ISSUED AT 322 AM EDT TUE MAR 28 2017  
 
DISCUSSION...  
 
QUIET FORECAST THROUGH THE MIDWEEK PERIOD AS HIGH PRESSURE ALOFT AND  
AT THE SURFACE BUILD INTO THE REGION. THE LAST OF WHATEVER LIGHT  
SHOWERS CAN DEVELOP OVER THE FAR SOUTHERN CWA WILL MOVE OFF EARLY  
THIS MORNING BUT ONLY A SLOW IMPROVEMENT IN CLOUD COVER WILL BE  
REALIZED. THE SURFACE HIGH CURRENTLY OVER MANITOBA, WILL TRACK  
ACROSS ONTARIO AND QUEBEC THROUGH THE WEEK WHICH WILL PLACE US IN  
THE SOUTHERN PERIPHERY OF THE RIDGE RESULTING IN DRIER AND COOLER  
EASTERLY FLOW. EXPECT A COOLING TREND THROUGH THURSDAY IN RESPONSE  
TO THIS SUSTAINED EASTERLY FLOW. STRONGER SUBSIDENCE ALOFT DUE TO AN  
AMPLIFYING RIDGE AHEAD OF THE NEXT SOUTHERN STREAM TROUGH WILL DRY  
THE COLUMN OUT FROM THE TOP DOWN. BASICALLY WE'LL END UP WITH A LOW  
STRATUS DECK AROUND 2-3KFT BY THIS AFTERNOON THAT SHOULD SCOUR OUT  
FROM NORTH TO SOUTH ALLOWING SOME SUN BY NIGHTFALL.  
 
WILL KEEP WITH THE COOL EASTERLY FLOW IN THE LOW LEVELS ON WEDNESDAY  
BUT A DRIER AIRMASS WILL RESULT IN PLENTY OF SUN THROUGH THE DAY.  
COULD SEE SOME CIRRUS DEBRIS AHEAD OF THE NEXT SYSTEM AND ALSO A FEW  
DIURNAL CU EARLY IN THE DIURNAL CYCLE BEFORE SCATTERING OUT. THE  
NEXT SYSTEM WILL BE OVER THE SOUTHERN PLAINS WEDNESDAY, PINCHING OFF  
FROM THE NORTHERN JET. SOUTHERN JET TRIES TO ABSORB IT BUT SOME  
ENERGY IN THE TROUGH REMAINS TIED TO THE NORTHERN JET WHICH ISN'T  
DOING THE MODELS ANY FAVORS. OVERALL THEY ARE PRETTY WELL IN SYNC BUT  
THE SETUP COULD TURN ONE WAY OR THE OTHER PRETTY QUICK. AS FOR NOW  
WILL GO WITH PERSISTENCE FORECASTING WITH THE STEADY MODEL OUTPUT.  
 
THE LOW WILL LIFT NORTHEAST WEDNESDAY NIGHT WITH GOOD WARM AIR  
ADVECTION CENTERED AROUND 5-10KFT AHEAD OF IT INTO THE REGION. LOW  
LEVEL EASTERLY FLOW FROM THE SURFACE HIGH WILL HOLD THROUGH THE DAY.  
LOOKS LIKE THE INITIAL RAIN WILL STAY TO OUR WEST LATE WEDNESDAY  
NIGHT AND THURSDAY MORNING AS THE 850MB JET SURGES NORTHWARD OVER  
WISCONSIN. THIS WOULD ALL BE ELEVATED SHOWERS ON THE LEAD ISENTROPIC  
LEAF BUT GETS A LITTLE COMPLICATED BY THE RIGHT ENTRANCE REGION OF  
THE NORTHERN STREAM JET MAX OVER NORTHERN LOWER. MODELS ARE TRYING  
TO LIGHT UP THIS EASTWARD EXTENSION OF THE ELEVATED FRONT THURSDAY  
MORNING FROM ABOUT FLINT NORTHWARD. DRY AIR IN THE LOWEST ~8KFT WILL  
MAKE IT TOUGH FOR THIS TO REACH THE GROUND BUT WILL BE SOMETHING TO  
WATCH. BETTER PRECIP CHANCES COME THURSDAY AFTERNOON AS THE 850MB  
JET SLIDES OVER LOWER MI BRINGING A SURGE OF BETTER THETA E INTO THE  
AREA. THIS IN CONJUNCTION WITH UPPER LEVEL DIFFLUENCE AND ISENTROPIC  
ASCENT LOOKS TO PRODUCE A BROAD COVERAGE OF SHOWERS ACROSS THE AREA.  
THERE DOES REMAIN A CHANCE OF SOME MIX PRECIP AT THE LEAD EDGE IF IT  
CAN GET GOING EARLY ENOUGH THURSDAY MORNING AS DRY, COOL SURFACE  
LAYER WILL WET BULB, BUT OVERALL THINK BEST PRECIP CHANCES WILL COME  
AFTER DIURNAL HEATING COMMENCES.  
 
RAIN WILL TAPER OFF OVERNIGHT AS THE SYSTEM PROGRESSES EASTWARD WITH  
THE LAST OF THE SHOWERS EXITING THE AREA FRIDAY MORNING. RIDGING  
WILL BUILD BACK INTO THE REGION FRIDAY FOR THE WEEKEND. THIS WILL  
BRING QUIET WEATHER AND A SLIGHT WARMING TREND BACK TO THE MID 50S.  
 
MARINE...  
 
NORTHERLY WINDS WILL INCREASE DURING THE DAY AS STRONG HIGH PRESSURE  
EXPANDS ACROSS THE NORTHERN GREAT LAKES. WIND GUSTS MAY REACH 20  
KNOTS ACROSS THE SOUTHERN LAKE HURON BASIN AND POSSIBLY SAGINAW BAY  
WHERE NORTHEAST WINDS WILL FUNNEL INTO THE BAY. THE HIGH WILL EXPAND  
INTO THE EASTERN GREAT LAKES BY WEDNESDAY. MODEST NORTHEAST WINDS  
WILL BE SUSTAINED AS A RESULT. LOW PRESSURE IS FORECAST TO LIFT INTO  
THE OHIO VALLEY ON THURSDAY BEFORE PUSHING INTO THE SOUTHERN GREAT  
LAKES ON FRIDAY. THIS SYSTEM COMBINED WITH STRONG HIGH PRESSURE TO  
THE NORTH WILL LEAD TO INCREASING EAST-NORTHEAST WINDS THURSDAY INTO  
FRIDAY, POSSIBLY RESULTING IN THE DEVELOPMENT OF SMALL CRAFT  
ADVISORY CONDITIONS.  
 

 
   
DTX WATCHES/WARNINGS/ADVISORIES
 
 
MI...NONE.  
LAKE HURON...NONE.  
LAKE ST CLAIR...NONE.  
MICHIGAN WATERS OF LAKE ERIE...NONE.  

 
 

 
 
AVIATION.....SC  
DISCUSSION...DRK  
MARINE.......SC  
 
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE  
AT WWW.WEATHER.GOV/DETROIT.  
 
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