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000
FXUS63 KDTX 060856
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
356 AM EST FRI DEC 6 2013

.SHORT TERM...TODAY AND TONIGHT

THE WEATHER FOR SOUTHEASTERN MICHIGAN WILL BE INFLUENCED BY A
BAROCLINIC ZONE THAT IS IN PLACE FROM THE EASTERN GREAT LAKES
THROUGH MUCH OF THE OHIO RIVER VALLEY. THE FRONTAL BOUNDARY WILL
BECOME QUASI-STATIONARY TODAY AS THE VERY STRONG...POLAR JET AXIS
OVERHEAD BECOMES FAIRLY STATIC. CHARACTERISTICS OF THE FRONT OFFERED
BY CROSS SECTIONS ARE: 1. GRADUALLY SLOPED 2. A DOUBLE GRADIENT
STRUCTURE AT ROUGHLY 750 MB AND 550 MB.

A WAVE IS EXPECTED TO RIPPLE ALONG THE BAROCLINIC ZONE LATE THIS
AFTERNOON AS A LOWER TROPOSPHERIC REFLECTION OF RIGHT ENTRANCE
REGION DYNAMICS. OVERALL PRECIPITATION CHANCES WILL BE NEAR ZERO FOR
MUCH OF THE CWA WITH CHANCES VERY LOW ACROSS MONROE COUNTY. THE
REASON IS ANALYSES OF LOW TO MID TROPOSPHERIC -DIV AND DEFORMATION
ADVERTISE VERY LITTLE FORCING. IN ADDITION...CROSS SECTIONS SUPPORT
SUBSIDENCE THIS AFTERNOON BETWEEN THE 750 MB AND 550 MB GRADIENTS
ALONG WITH RELATIVELY HIGH STATIC STABILITY THROUGH A GOOD CHUNK OF
THE COLUMN. A DRY LAYER BELOW THE 750MB GRADIENT WILL PROVIDE AN
EVAPORATION BUFFER. IN THE SPIRIT OF CONTINUITY...CONTINUED TO
INCLUDE A LOW CHANCE POP OF LIGHT SNOW FOR MONROE COUNTY BETWEEN
21-02Z BUT ANY SNOWFALL...IF ANY...WILL BE NEGLIGIBLE. SOME FORCING
VERY HIGH IN COLUMN IS STILL EXPECTED TO OVERLAP SOUTHEASTERN
MICHIGAN WHICH SHOULD PROVIDE AN ABUNDANCE OF HIGH CLOUD FOR MUCH OF
THE DAYLIGHT HOURS.

SLUGGISH MOVEMENT OF THE FRONT TODAY WILL GIVE SOME POTENTIAL AT
AFTERNOON HIGHS DESPITE THE CLOUDS. FREEZING MARK SOUTH...TO MIDDLE
20S NORTH. WIND CHILLS WILL DROP INTO THE TEENS THIS MORNING...THEN
STRUGGLE TO CLIMB ABOVE 20 FOR THE AFTERNOON. SUBSIDENCE OCCURRING
BEHIND THE WAVE LATE TONIGHT ALONG WITH DRY AIR SHOULD ALLOW CLOUDS
TO SCATTER AN HOUR OR TWO BEFORE SUNRISE. TEMPERATURES WILL HAVE THE
POTENTIAL TO DROP...LOWS IN THE TEENS WIND CHILLS IN THE SINGLE
DIGITS FOR ALL OF SOUTHEASTERN MICHIGAN.

&&

.LONG TERM...SATURDAY THROUGH THURSDAY

HIGH AMPLITUDE MID LEVEL FLOW ANCHORED BY A SPRAWLING LONGWAVE
TROUGH WILL REMAIN THE CONTROLLING LARGE SCALE FEATURE WELL INTO
NEXT WEEK.  THE WEEKEND BEGINS WITH SE MICHIGAN INITIALLY RESIDING
ALONG THE EASTERN EXTENSION OF THE MAIN HEIGHT FALL CENTER AND WELL
WITHIN THE COLD DOME PERPETUATED BY AN INBOUND 1040 MB ARCTIC HIGH.
AMBIENT AIRMASS WILL CARRY A DEEP DRY LAYER ABOVE 900 MB...WHILE A
CHECK OF UPSTREAM SOUNDINGS ACROSS LAKE MICHIGAN SHOW A PROFILE ALSO
LACKING IN MOISTURE DEPTH WITH SUPPRESSED INVERSION HEIGHTS.  THIS
WOULD INDICATE THE OPPORTUNITY FOR A LAKE AND/OR DIURNALLY ENHANCED
STRATOCU FIELD WILL BE LIMITED.  SOME LINGERING EARLY STRATUS MAY
EXIST...PARTICULARLY ACROSS THE NORTH WITH THE RESIDUAL MOISTURE
SOURCE FROM TODAY PERHAPS SLOWER TO MIX OUT.  MAIN STORY WILL BE
TEMPERATURES...WITH EVEN A HIGH DEGREE OF INSOLATION STRUGGLING TO
MODERATE A THERMAL PROFILE CARRYING 925 MB TEMPERATURES IN THE -11
TO -12C RANGE.  THIS WILL TRANSLATE INTO HIGHS OF LOWER TO MIDDLE
20S...OR A GOOD 15 DEGREE BELOW EARLY DECEMBER NORMS.  THE EXISTING
SURFACE RIDGING AND DEEP DRY LAYER WILL PROMOTE A GOOD RADIATIONAL
COOLING RESPONSE SATURDAY NIGHT.  A GRADUALLY INCREASING CIRRUS
SHIELD WILL BE THE ONE POSSIBLE DISRUPTION TO REALIZING THE FULL
POTENTIAL.  OVERALL STILL LOOKING AT LOWS IN THE TEENS...A FEW
SINGLE DIGIT READINGS NOT OUT OF THE QUESTION IN THE COLDEST
LOCALES.

CONDITIONS INTO SUNDAY REMAIN DEFINED BY THE PRESENCE OF A COLD/DRY
ENVIRONMENT...LOW LEVEL FLOW FLIPPING TO EASTERLY WITH THE ARCTIC
HIGH SLOWLY EASING EASTWARD.  HIGHS AGAIN IN THE 20S...EFFECTIVELY
CONTAINED BY A MORE CONCERTED INCREASE IN HIGH CLOUD.  FOCUS INTO
SUNDAY EVENING/NIGHT THEN TURNS TO A WELL DEFINED PV ANOMALY WORKING
THROUGH THE TROUGH BASE.  THIS WAVE WILL SHEAR INTO THE PREVAILING
SOUTHWESTERLIES ORIENTED FROM THE CENTRAL PLAINS INTO THE GREAT
LAKES THROUGH THE LATTER HALF OF THE WEEKEND.  THIS PROCESS WILL
PROMPT TWO AREAS OF FOCUS...ONE WITHIN A WING OF EMERGING ISENTROPIC
ASCENT AND MOISTURE TRANSPORT ORIGINATING OUT OF THE WESTERN
GULF...AND A SECOND ACCOMPANYING THE PRIMARY REGION OF FORCED ASCENT
CONTAINED WITHIN THE MAIN HEIGHT FALL CENTER AND ALONG THE
DEVELOPING WEAK SURFACE WAVE AND FRONTAL CIRCULATION EJECTING OUT OF
THE PLAINS.  THE OVERALL UPPER JET POSITIONING WOULD TEND TO DIRECT
THE BULK OF THE GULF ORIGINATING MOISTURE AND ATTENDANT WEAK ASCENT
TO OUR SOUTHEAST.  IT REMAINS PLAUSIBLE FOR SOUTHERN SECTIONS OF
SOUTHEAST MICHIGAN TO RECEIVE A GLANCING SHOT ALONG THE WESTERN EDGE
SUNDAY EVENING.  WEAK SURFACE WAVE THEN LIFTS THROUGH LOWER MICHIGAN
SUNDAY NIGHT...DISPLACED SOUTHEAST OF THE MAIN STRIPE OF DCVA AND
DEFORMATION FORCING SHIFTING FROM THE UPPER MS VALLEY INTO THE U.P.
THIS WILL LEAVE SE MICHIGAN UNDER A BROADER LOOKING PERIOD OF
FORCING...STILL SUFFICIENT TOWARD GENERATING A FEW HUNDREDTHS OF QPF
SUNDAY NIGHT.  A SUB-FREEZING THERMAL PROFILE THROUGHOUT WILL
SUPPORT ALL SNOW...ALTHOUGH THE PROFILE WILL BE WARMING WITH
TIME...EFFECTIVELY REDUCING POTENTIAL SNOWFALL RATIOS.

A GENERAL EASTWARD MIGRATION OF THE MEAN LONGWAVE TROUGH WILL DIRECT
A SERIES SHORTWAVES OF SIBERIAN ORIGIN THROUGH THE GREAT LAKES
DURING THE EARLY AND MID WEEK PERIOD.  THIS WILL RESULT IN AN
EXTENDED STRETCH OF WELL BELOW NORMAL TEMPERATURES AS ARCTIC AIR
TAKES FIRM RESIDENCE THROUGHOUT THE WEEK.

&&

.MARINE...

WESTERLY WINDS WILL DIMINISH SLIGHTLY TODAY AND TONIGHT AS THE
PRESSURE GRADIENT EASES BEHIND LOW PRESSURE LIFTING INTO QUEBEC.
THIS WILL RESULT IN A LOWER WAVE CONDITIONS THROUGH THIS TIME.
COLDER AIR MOVING ACROSS THE WATERS WILL MAINTAIN WIND SPEEDS IN
THE 15 TO 20 KNOT RANGE ACROSS NORTHERN PORTIONS OF LAKE HURON.
SLIGHT INCREASE IN WINDS EARLY SATURDAY WILL BRING GUSTS JUST SHY
OF GALES ACROSS NORTHERN LAKE HURON.  STRONG HIGH PRESSURE WILL
THEN TAKE CONTROL SATURDAY NIGHT AND SUNDAY.

&&

.AVIATION...ISSUED 1146 PM EST THU DEC 5 2013

//DISCUSSION...

A FEW MVFR CLOUDS ARE SWIRLING AROUND CENTRAL MICHIGAN...HOWEVER
THEIR EFFECT IS EXPECTED TO BE MINIMAL WITH AT BEST A SCT DECK AT
2500 FT EXPECTED OVERNIGHT. LOW PRESSURE MOVING THROUGH THE OHIO
VALLEY WILL BRING LOWER CLOUDS INTO THE SOUTHERN GREAT LAKES THROUGH
THE OVERNIGHT HOURS AND INTO FRIDAY. HOWEVER THE CIGS ARE EXPECTED
TO REMAIN IN THE VFR CATEGORY WITH THE LOWEST CIGS EXPECTED AT THE
METRO AIRPORTS FRIDAY AFTERNOON WITH BASES AROUND 4K FT.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE IN CEILINGS AT OR BELOW 5000 FT FRIDAY AFTERNOON.

&&

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

&&

$$

SHORT TERM...CB
LONG TERM....MR
MARINE.......MR
AVIATION.....KURIMSKI

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