482  
FXUS63 KDTX 011040  
AFDDTX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI  
640 AM EDT SAT NOV 1 2014  
 
   
AVIATION
 
 
//DISCUSSION...  
 
WIDESPREAD MVFR STRATOCU WILL ONLY SLOWLY ERODE THROUGH THE MORNING.  
CLEARING WILL WORK INTO KMBS BY NOON BUT WILL TAKE THE BETTER PART  
OF THE DAYLIGHT HOURS TO WORK INTO THE REMAINING AIRFIELDS.  
NORTHERLY GUSTS OF 20 TO 25 KNOTS KNOTS WILL PERSIST UNTIL SUNSET  
THIS EVENING WHEN HIGH PRESSURE WILL EASE THE PRESSURE GRADIENT AND  
ALLOW SUSTAINED WINDS TO FALL BELOW 10 KNOTS. AN OCCASIONAL FLURRY  
WILL BE POSSIBLE INTO EARLY AFTERNOON BUT NOTHING WORTH A SPECIFIC  
MENTION IN THE TAF.  
 
//DTW THRESHOLD THREATS...  
 
* MEDIUM CONFIDENCE IN CEILINGS BELOW 5KFT  
 

 
   
PREV DISCUSSION
 
ISSUED 321 AM EDT SAT NOV 1 2014  
 
SHORT TERM...TODAY AND TONIGHT  
 
EARLY MORNING OBSERVATIONS REVEAL WIDESPREAD TEMPERATURES IN THE LOW  
TO MID 30S BENEATH AN EXTENSIVE LAKE ENHANCED STRATOCU DECK. WINDS  
WITHIN THE WELL-MIXED BOUNDARY LAYER CONTINUE GUSTING 30 TO 35 MPH  
PRODUCING WIND CHILLS IN THE UPPER TEENS TO LOW 20S. IN ADDITION,  
MODERATE INSTABILITY WITHIN NORTHERLY FLOW OVER LAKE HURON IS  
SUPPORTING LAKE EFFECT RAIN AND SNOW SHOWERS, WITH FAR EASTERN AREAS  
STILL STRUGGLING TO CHANGE OVER DUE TO WARM ADVECTION OFF THE LAKE.  
 
THIS MORNING'S WATER VAPOR IMAGERY REVEALS A SIGNIFICANT DISRUPTION  
TO STRATOCU COVERAGE OVER WESTERN LOWER DUE TO SUBSIDENCE TRAILING  
THE PASSING MID-LEVEL TROUGH AXIS. THIS BAND OF SUBSIDENCE WILL WORK  
ACROSS THE AREA BETWEEN NOW AND ABOUT 13Z, WHICH WILL LIKELY LEAD TO  
SOME COMPROMISING OF THE INTEGRITY OF THE CLOUD SHIELD, BUT  
INCREASING DIURNAL INSTABILITY AND CONTINUED THETA-E FLUX OFF THE  
LAKE WILL BE AN OFFSETTING FACTOR AND WILL HELP SUSTAIN MOSTLY  
CLOUDY TO CLOUDY CONDITIONS FOR ALL BUT THE WESTERNMOST AREAS WELL  
INTO THE AFTERNOON. DISSIPATION OF CLOUDS OVER MOST OF SE MI WILL  
HAVE TO WAIT UNTIL DEEP LAYER ANTICYCLONIC FLOW BUILDS IN FROM WEST  
TO EAST 18Z-00Z BEHIND THE DEPARTING THERMAL TROUGH THIS AFTERNOON,  
LEADING MOST AREAS TO REMAIN SOLIDLY BENEATH EXTENSIVE CLOUD COVER  
FOR MOST OF THE DAY. TEMPERATURES WILL STRUGGLE TO RECOVER AT ALL  
FROM EARLY MORNING LOWS SPELLING HIGHS RANGING FROM 36 TO  
40...LOWEST ALONG THE GLACIAL RIDGE. WIND CHILLS WILL BE 25-30F FOR  
THE BALANCE OF THE DAYLIGHT HOURS.  
 
BUILDING HEIGHTS WILL FORCE SURFACE HIGH PRESSURE TO TRANSLATE INTO  
THE REGION TONIGHT. ASSUMING COMPLETE EROSION OF LAKE CLOUDS BY  
SUNSET, OVERNIGHT LOWS WILL FALL WELL INTO THE 20S AREAWIDE. ANY  
LOCATIONS THAT HAVEN'T YET HAD A HARD FREEZE WILL GET IT TONIGHT.  
THERMAL TROUGHING ALONG THE SHORELINE WILL KEEP THE GRADIENT UP A  
BIT AND SUPPORT SLIGHTLY WARMER LOWS OF 25-28. WEST OF US-23, LOWS  
MAY FALL TO 20 DEGREES...PERHAPS AN ISOLATED UPPER TEENS  
READING...BEFORE HIGH CLOUDS PRESENTLY OVER NORTH DAKOTA SPREAD INTO  
THE AREA DURING THE PREDAWN HOURS.  
 
LONG TERM...SUNDAY THROUGH FRIDAY  
 
AFTER A COLD START TO THE DAY SUNDAY...AFTERNOON HIGHS SHOULD RISE  
INTO THE 40S AS THE LOW LEVEL FLOW BACKS TOWARD THE WEST MARKING THE  
ONSET OF LOW LEVEL WARM AIR ADVECTION. THIS WARM AIR ADVECTION  
REGIME WILL PERSIST INTO MON NIGHT. A PROGRESSIVE LONG WAVE TROUGH  
ADVANCING ACROSS THE WRN US WILL FORCE A HIGH AMPLITUDE MID LEVEL  
RIDGE ACROSS THE GREAT LAKES SUN INTO MON...MAINTAINING DRY  
CONDITIONS ACROSS THE FORECAST AREA. DESPITE LINGERING DRY AIR IN  
THE LOW-MID LEVELS ON SUNDAY...MODEL PLAN VIEWS SUGGEST A GOOD  
DEGREE OF HIGH LEVEL MOISTURE SPILLING OVERTOP THE APPROACHING MID  
LEVEL RIDGE AND CASCADING ACROSS LOWER MI /SUGGESTING OPAQUE SKIES  
AT TIMES/. LOW TO MID LEVEL MOISTURE WILL THEN ADVANCE INTO LOWER MI  
MON AND MON NIGHT WITHING STRENGTHENING W-SW FLOW AHEAD OF THE LONG  
WAVE TROUGH PUSHING INTO THE CENTRAL US. WHILE THIS WILL INCREASE  
CLOUD COVER ON MON...THE DEGREE OF LOW LEVEL WARMING STILL SUGGESTS  
DAYTIME HIGHS WILL RISE INTO THE 50S.  
 
THE MEDIUM RANGE MODEL SUITE SUGGEST THE SOUTHERN BRANCH OF THE LONG  
WAVE TROUGH WILL EVOLVE INTO A CUT OFF CIRCULATION OVER NRN MEXICO  
TUES INTO WED...WHILE THE NORTHERN BRANCH REMAINS PROGRESSIVE AND  
ROTATES INTO THE GREAT LAKES. PERSISTENT DEEP LAYER MOISTURE  
ADVECTION AND ISENTROPIC ASCENT ALONG WITH INCREASING FRONTOGENESIS  
ALONG THE ASSOCIATED COLD FRONT WILL SUPPORT A GOOD CHANCE OF  
SHOWERS IN THE MON NIGHT TO TUES TIME FRAME. ALTHOUGH MODEL  
SOLUTIONS DIVERGE WITH RESPECT TO THE TIMING OF ADDITIONAL NORTHERN  
STREAM WAVES ROTATING INTO THE REGION TOWARD THE END OF THE WEEK...A  
GENERAL CONSENSUS REMAINS THAT SOME SEMBLANCE OF LARGE SCALE TROUGH  
AMPLIFICATION WILL OCCUR ACROSS THE GREAT LAKES THURS INTO FRI. THIS  
WILL SUPPORT A COOLING TREND DURING THE LATER HALF OF THE WORK WEEK.  
 
MARINE...MARINE OBSERVATIONS STILL SUGGEST GALE FORCE WINDS ARE  
ONGOING ACROSS SOUTHERN LAKE HURON AND WESTERN LAKE ERIE. THE WINDS  
AND WAVES WILL STEADILY DECREASE DURING THE MORNING AND AFTERNOON AS  
HIGH PRESSURE BUILDS IN FROM THE WEST AND WEAKENS THE GRADIENT OVER  
THE ERN GREAT LAKES. THIS HIGH WILL THEN INFLUENCE THE REGION  
THROUGH THE END OF THE WEEKEND PROVIDING RELATIVELY LIGHT WINDS IN  
COMPARISON TO THE LAST COUPLE OF DAYS. S-SW WINDS WILL INCREASE  
MONDAY INTO TUESDAY. WARMER AIR WILL ALSO FILTER INTO THE REGION  
WILL WILL BOOST THE STABILITY OVER THE LAKES AND WILL SUPPRESS THE  
MAGNITUDE OF THE WINDS.  
 
CLIMATE...  
 
RECORD LOW HIGH TEMPERATURES FOR 11/1:  
DETROIT AREA (DTW).....30F (1879)  
FLINT AREA (FNT).......36F (1996)  
TRI-CITIES (MBS).......38F (2002)  
 
RECORD LOW TEMPERATURES FOR 11/2:  
DETROIT AREA (DTW).....22F (1951)  
FLINT AREA (FNT).......20F (1951)  
TRI-CITIES (MBS).......18F (1951)  
 

 
   
DTX WATCHES/WARNINGS/ADVISORIES
 
 
MI...NONE.  
LAKE HURON...GALE WARNING UNTIL NOON EDT TODAY FOR LHZ363-441>443-462>464.  
 
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LHZ421-422.  
 
LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LCZ460.  
 
MICHIGAN WATERS OF LAKE ERIE...GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LEZ444.  
 

 
 

 
 
AVIATION.....JVC  
SHORT TERM...JVC  
LONG TERM....SC  
MARINE.......SC  
CLIMATE......JVC  
 
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE  
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab MI Page Main Text Page