345  
FXUS63 KDTX 092332  
AFDDTX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI  
632 PM EST SUN FEB 9 2025  
   
KEY MESSAGES
 
 
 
- A MID-WINTER TEMPERATURE PATTERN HOLDS READINGS IN THE MID 20S TO  
NEAR 30 DURING THE DAY AND IN THE TEENS AT NIGHT THROUGH THE EARLY  
WEEK PERIOD.  
 
- DRY WEATHER IS EXPECTED MONDAY THROUGH WEDNESDAY MORNING OUTSIDE  
OF A FEW FLURRIES TUESDAY NIGHT.  
 
- ANOTHER ROUND OF WIDESPREAD SNOWFALL REMAINS POSSIBLE WEDNESDAY  
AND THURSDAY AS A LOW PRESSURE SYSTEM IS FORECAST TO MOVE THROUGH  
THE OHIO RIVER VALLEY.  
 
- REINFORCEMENT OF BELOW NORMAL TEMPERATURES FOLLOWS THIS SYSTEM FOR  
THE LATE WEEK PERIOD.  
 

 
   
AVIATION
 
 
STEADY DRYING OF THE LOW LEVEL ENVIRONMENT WILL SUPPORT A MORE  
LIMITED COVERAGE OF STRATUS GOING FORWARD TONIGHT. CLEARING TREND  
NOTED ON SATELLITE THIS EVENING WILL FAVOR WIDESPREAD VFR WITH  
PRIMARILY A SCATTERED COVERAGE OF STRATUS. THERE REMAINS SOME  
POTENTIAL FOR BRIEF INTERLUDES OF HIGHER/BROKEN COVERAGE TO EMERGE  
AS SUFFICIENT COLD WESTERLY FLOW MAINTAINS THE POSSIBILITY FOR SOME  
DEGREE OF DOWNSTREAM LAKE MOISTURE FLUX. SIMILAR ENVIRONMENT REMAINS  
ENTRENCHED INTO MONDAY. FORECAST WILL CONTINUE TO OUTLOOK SIMPLY A  
SCATTERED COVERAGE OF LOWER VFR CLOUD UNTIL UPSTREAM TRENDS INDICATE  
OTHERWISE. WINDS FROM A WEST TO SOUTHWEST DIRECTION GENERALLY AOB 12  
KNOTS THROUGH THE PERIOD.  
 
DTW THRESHOLD PROBABILITIES...  
 
* LOW FOR CEILING 5000 FEET OR LESS TONIGHT AND MONDAY.  
 

 
   
PREV DISCUSSION
 
 
ISSUED AT 353 PM EST SUN FEB 9 2025  
 
DISCUSSION...  
 
MID AFTERNOON OBSERVATIONS UPSTREAM INDICATE THE ANTICIPATED  
DECREASING CLOUD TREND UNFOLDING WEST TO EAST ACROSS LOWER MI THIS  
EVENING. THE OPEN SKY COMBINED WITH LIGHT WIND WILL HELP THE  
TYPICALLY COLDER SAGINAW VALLEY AND THUMB REGIONS REACH SINGLE DIGIT  
LOW TEMPERATURES HEADING INTO SUNRISE MONDAY. BENIGN SURFACE HIGH  
PRESSURE THEN HOLDS THROUGH MONDAY UNTIL A REINFORCING COLD FRONT  
ARRIVES MONDAY NIGHT. THIS FRONT IS ASSOCIATED WITH A NORTHERN STREAM  
SHORT WAVE PROGRESSING ACROSS ONTARIO WHILE SWINGING THE FRONT INTO  
AN ALREADY MOISTURE STARVED AIR MASS ACROSS THE GREAT LAKES. THE  
MUTED LAKE EFFECT RESPONSE KEEPS SNOW SHOWERS CLOSER TO THE  
SHORELINES AND POSSIBLY SUPPLIES A FEW FLURRIES ACROSS SOUTHERN LOWER  
MI INTO TUESDAY MORNING.  
 
THIS FRONT REINFORCES THE ALREADY FORMIDABLE BAROCLINIC ZONE STALLED  
IN THE TN VALLEY REGION WHILE CP HIGH PRESSURE MAINTAINS BELOW  
NORMAL GREAT LAKES TEMPERATURES TUESDAY AND WEDNESDAY. READINGS IN  
THE 20S DURING THE DAY AND SINGLE DIGITS TO TEENS AT NIGHT OUTSIDE  
OF METRO DETROIT ARE ACCOMPANIED BY DRY WEATHER AND LIGHT WIND.  
 
THE BELOW NORMAL TEMPERATURES HELP SET THE STAGE FOR AN EASY CALL ON  
AN ALL SNOW SCENARIO FOR THE WED NIGHT/THU SYSTEM AS IT MOVES  
THROUGH THE CENTRAL PLAINS INTO THE TN/OH VALLEY. GIVEN THE SYSTEM  
IS STILL OUTSIDE OF 72 HRS, CONSISTENCY BETWEEN THE DETERMINISTIC  
MODEL SOLUTIONS AND ENSEMBLE MEANS IS GOOD ON THE SHAPE OF THE  
LARGER SCALE MID LEVEL FLOW AND UPPER LEVEL JET STRUCTURE, ALTHOUGH  
THERE ARE THE USUAL TIMING AND AMPLITUDE DIFFERENCES ON THE LEADING  
SHORT WAVE THAT HAS MEANING ON GREAT LAKES FORECAST OUTCOMES. THERE  
IS EARLY CONSENSUS ON MODEL QPF THAT SHOWS SIGNS OF FAVORING A FOCUS  
AREA FROM MO/IL INTO SOUTHERN LOWER MI FOR THE LEADING ZONE OF WARM  
ADVECTION SNOW. MOISTURE TRANSPORT AVERAGING 2-3 G/KG SPECIFIC  
HUMIDITY IN THE 850-700 MB LAYER RAMPS UP CONSIDERABLY AND IS PLENTY  
ADEQUATE EVEN IF THERE IS SOME THEFT BY CONVECTION NEAR THE TN VALLEY  
SURFACE LOW AND WARM FRONT. THIS MOISTURE IS FED INTO A ZONE OF  
STRONG THETA-E ADVECTION DURING THE DAY WEDNESDAY, ENHANCED BY  
FAVORABLE POSITIONING FOR MID LEVEL FGEN INTO THE 160+ KNOT UPPER JET  
OVER THE GREAT LAKES. THESE ARE BULK FEATURES OF THE SYSTEM THAT ARE  
EXPECTED TO HOLD WITH ABOVE AVERAGE PREDICTABILITY AND COULD RESULT  
IN THE FIRST INCH OF SE MI SNOW ACCUMULATION BY SUNSET (09/00Z) WED  
EVENING. QUESTIONS THEN REMAIN TO BE ANSWERED IN UPCOMING FORECAST  
CYCLES FOR THE EVENT PEAK WED NIGHT INTO THURSDAY AS MODELS SPLIT  
INTO TWO MAIN CAMPS OF SOLUTIONS. THERE IS A ECMWF LED CAMP HAVING A  
DEEPER 500 MB TROUGH AND SURFACE LOW ON A TRACK CLOSER TO CLE WHICH  
BRINGS CONSIDERABLY MORE SNOW INTO SE MI. THIS IS COMPARED TO A GFS  
LED CAMP OF A WEAKER LEAD 500 MB WAVE AND A MORE OPEN SURFACE LOW  
FARTHER SOUTH. AS OF TODAY'S 09/12Z MODEL CYCLE, THE EDGE MAY GO  
TOWARD THE FORMER SOLUTION AS THE GFS ENSEMBLE MEAN LEANS THE  
DETERMINISTIC GFS TOWARD THE ECMWF FAVORED SOLUTION OF A STRONGER  
LEADING MID LEVEL WAVE.  
 
AN AGGRESSIVE SURGE OF POLAR AIR FOLLOWS THE LOW PRESSURE SYSTEM  
THURSDAY INTO THURSDAY NIGHT. MODEL BLENDED TEMPERATURE GUIDANCE IS  
WELL DOWN INTO THE SINGLE DIGITS ACROSS ALL OF SE MI BY FRIDAY  
MORNING. BROAD HIGH PRESSURE DOMINATES WITH DRY CONDITIONS FRIDAY  
FOLLOWED BY ANOTHER LOW PRESSURE SYSTEM ON A SIMILAR TRACK THROUGH  
THE REGION THIS WEEKEND.  
 
MARINE...  
 
BROAD AREA OF HIGH PRESSURE OVER THE CENTRAL PLAINS GRADUALLY BUILDS  
OVER THE SOUTHERN GREAT LAKES TONIGHT RESULTING IN STEADILY  
WEAKENING WESTERLY WINDS. WHILE SIMILAR WEAKENING TRENDS CAN BE  
EXPECTED TO OVER THE SOUTHERN HALF OF LAKE HURON, LOW PRESSURE  
ACROSS NORTHERN ONTARIO PREVENTS THE PRESSURE GRADIENT FROM  
LOOSENING OVER NORTHERN LAKE HURON. WINDS FOR THIS PORTION OF THE  
LAKE REMAIN AROUND 20KTS THROUGH MONDAY. WINDS SHIFT MORE TO THE NW  
EARLY TUESDAY AS A WEAK ARCTIC COLD FRONT SINKS ACROSS THE CENTRAL  
GREAT LAKES. GUSTS REACH BETWEEN 20-30KTS ALONG/IMMEDIATE WAKE OF  
THE FRONTAL PASSAGE- STRONGEST WINDS IN RANGE FOCUSED OVER THE  
NORTHERN HALF OF HURON. A FEW SNOW SHOWERS POSSIBLE ALONG THE FRONT  
AS WELL. WINDS THEN WEAKEN AGAIN DAYTIME TUESDAY AS HIGH PRESSURE  
BUILDS BACK OVER THE GREAT LAKES.  
 

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

 
 

 
 
AVIATION.....MR  
DISCUSSION...BT  
MARINE.......KDK  
 
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE  
AT WWW.WEATHER.GOV/DETROIT.  
 
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