National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KDTX 290853
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
353 AM EST FRI NOV 29 2013

.SHORT TERM...TODAY AND TONIGHT

SHORTWAVE RIDGING WILL TRANSLATE THROUGH THE GREAT LAKES REGION
DURING THE NEXT 24 HOURS AGAINST A BACKDROP OF REBOUNDING HEIGHTS
COURTESY OF THE DEPARTING UPPER TROUGH. SUBSIDENCE WILL LIMIT
DIURNAL MIXING DEPTHS TO AROUND 925MB THIS AFTERNOON WITH HEATING
EVEN FURTHER LIMITED BY THE ADVECTION OF HIGH CLOUDS FROM CENTRAL
CANADA WITHIN NW FLOW ALOFT, ESPECIALLY FOR WESTERN AREAS.
THEREFORE, ONLY A LIMITED TEMPERATURE RECOVERY FROM YESTERDAY`S
HIGHS IN THE MID TO UPPER 20S IS FORECAST WITH ONLY THOSE LOCATIONS
IN THE METRO AREA AND POINTS SOUTH EXPECTED TO BREAK 30 DEGREES.
WEAK GRADIENT CONDITIONS IMMEDIATELY BEHIND THE DEPARTING SURFACE
HIGH ARE THEN EXPECTED FOR THE FIRST HALF OF TONIGHT BEFORE EMERGING
RETURN FLOW AND A CONTINUING THICKENING OF MID/HIGH CLOUDS LIMIT THE
RATE OF COOLING FOR THE REST OF THE NIGHT. TWEAKED LOWS UPWARD INTO THE
20-25F RANGE.

&&

.LONG TERM...SATURDAY THROUGH THURSDAY

TEMPERATURES WILL GRADUALLY MODERATE THIS WEEKEND INTO EARLY NEXT
WEEK AS THE CORE OF THE CURRENT POLAR HIGH PRESSURE SYSTEM SHIFTS
EAST. TEMPERATURES WILL REMAIN COOL...HOWEVER...AS UPPER TROUGHING
REMAINS IN PLACE. EXPECT HIGHS IN THE MIDDLE 30S TO AROUND 40 INTO
TUESDAY OR SO WITH LOW TEMPERATURES GENERALLY RANGING IN THE 20S.
ANY PRECIPITATION WILL BE VERY LIGHT AND SPOTTY AS SEVERAL WAVES
TRAVERSE THE AREA.

UPPER LEVEL PATTERN DOES BEGIN TO CHANGE BY MIDWEEK AS LARGE UPPER
TROUGH COVERING MUCH OF THE WESTERN HALF OF THE CONUS EVOLVES AND
UPPER RIDGING BUILDS INTO THE GREAT LAKES TO THE EAST OF THIS
FEATURE. THIS WILL BRING MILDER TEMPERATURES YET AND EVENTUALLY
HIGHER PRECIPITATION CHANCES BY THE END OF THIS FORECAST PERIOD.
SO FAR...MODELS HAVE NOT BEEN VERY CONSISTENT WITH THE EVOLUTION OF
THIS TROUGH...OR ANY SHORTWAVES EJECTING FROM IT FOR THAT MATTER.
SO...FORECAST CONFIDENCE REMAINS MORE IFFY THAN USUAL.

&&

.MARINE...

A LARGE AREA OF HIGH PRESSURE WILL BUILD INTO THE AREA TODAY AND
THEN CONTINUE EASTWARD OVER THE WEEKEND. SOUTH TO SOUTHWEST WINDS
WILL INCREASE WITHIN PRESSURE GRADIENT BETWEEN THIS DEPARTING HIGH
AND THE NEXT APPROACHING COLD FRONT. WITH MARGINAL TO MODEST
INSTABILITY STILL IN PLACE OVER LAKE HURON...WINDS WILL ONCE AGAIN
BECOME RATHER GUSTY. AT THIS TIME...IT APPEARS THAT WIND GUSTS WILL
GENERALLY TOP OUT AROUND 30 KNOTS ON SATURDAY...BUT A FEW GUSTS MAY
APPROACH GALE FORCE OVER CENTRAL LAKE HURON. THE PASSAGE OF THE WEAK
COLD FRONT SATURDAY NIGHT WILL LEAD TO LIGHTER NORTHWEST WINDS FOR
SUNDAY.

&&

.AVIATION...ISSUED 1157 PM EST THU NOV 28 2013

//DISCUSSION...

LINGERING LAKE ENHANCED MOISTURE AND COMPLETE DECOUPLING OF THE
BOUNDARY LAYER PROVIDING A FAVORABLE ENVIRONMENT FOR SOME
REINTRODUCTION OF A LOWER CEILING AND/OR VISIBILITY REDUCTION EARLY
THIS MORNING.  RECENT OBSERVATIONAL AND SATELLITE TRENDS SUGGEST THE
NORTHERN TAF SITES ARE MORE FAVORABLY POSITIONED FOR FLUCTUATIONS
FROM LOWER VFR INTO IFR THROUGH AT LEAST THE PRE-DAWN HOURS.  A
LONGER PERIOD OF CLEARING WOULD LEAVE MBS/FNT VULNERABLE TO LIFR
VSBY GIVEN THE FRESH SNOW/ SATURATED NEAR SURFACE CONDITIONS.
DIMINISHING CERTAINTY TOWARD THE SOUTH WHERE LOW LEVEL DRYING
CARRIES MORE DEPTH.

//DTW THRESHOLD THREATS...

* LOW CONFIDENCE IN CEILINGS BELOW 5000 FT THROUGH FRIDAY MORNING...
MEDIUM CONFIDENCE IN THE AFTERNOON.

&&

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

&&

$$

SHORT TERM...JVC
LONG TERM....DG
MARINE.......DG
AVIATION.....MR


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).