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000
FXUS63 KDTX 101705
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
105 PM EDT MON MAR 10 2014


.AVIATION...

//DISCUSSION...

VFR MIDCLOUD DECK IS NOW EAST OF THE TERMINAL CORRIDOR. SUNSHINE
/FILTERED THROUGH HIGH CIRRUS AT TIMES/ SHOULD AID MIXING
POTENTIAL TO A DEGREE...WITH WEST-SOUTHWEST GUSTS TO 20-25 KT
DEVELOPING THIS AFTERNOON. GUSTINESS SHOULD DIMINISH AROUND
SUNDOWN. MIDLEVEL CLOUDS REDEVELOP OVERNIGHT AS AN ELEVATED FRONT
STRENGTHENS AND MOVES SLOWLY INTO THE REGION. LOW LEVELS WILL
REMAIN TOO DRY FOR PRECIPITATION INITIALLY...BUT CEILINGS WILL
LOWER THROUGH THE MORNING TUESDAY. LIGHT PRECIPITATION IS POSSIBLE
BY TUESDAY AFTERNOON...ESPECIALLY OVER THE NORTHERN
TERMINALS...BUT CONFIDENCE IS TOO LOW TO MENTION IN THE TAFS AT
THIS TIME.

//DTW THRESHOLD THREATS...

* NONE.

&&

.PREV DISCUSSION...ISSUED 1100 AM EDT MON MAR 10 2014

UPDATE...
ONLY MINOR TWEAKS WERE MADE TO THE GOING FORECAST TO ACCOUNT FOR
PASSING AREA OF MIDLEVEL CLOUDS ASSOCIATED WITH MINOR UPGLIDE ON
THE 300K SURFACE. THE BACK EDGE OF THIS CLOUD DECK IS ADVANCING
STEADILY EASTWARD...SO A CLEARING TREND IS EXPECTED FROM WEST TO
EAST ACROSS THE CWA FROM 16-18Z. AFTER THAT...UPSTREAM OBS AND
SATELLITE INDICATE MOSTLY SUNNY SKIES ASIDE FROM SOME CIRRUS. WITH
MARCH SUN ANGLE AND SOME SHALLOW MIXING...STILL ANTICIPATING
HIGHS APPROACHING OR EXCEEDING 50F /DESPITE MODEL GUIDANCE
GENERATING SPURIOUS LOW CLOUDS AND RESULTING COOL TEMPS/.

PREV DISCUSSION...ISSUED 346 AM EDT MON MAR 10 2014

SHORT TERM... TODAY AND TONIGHT

EARLY MORNING SURFACE ANALYSIS SINCE MIDNIGHT INDICATE LOW PRESSURE
OFF THE NORTH SHORE OF LAKE SUPERIOR GIVING WAY TO THE NEXT WAVE
MOVING THROUGH MANITOBA. THIS SYSTEM WILL MAINTAIN MODERATE
SOUTHWEST FLOW INTO LOWER MICHIGAN AND BRING A NEW SURGE OF MILD AIR
INTO THE REGION TODAY. EARLY MORNING TEMPERATURES RISING THROUGH THE
30S WILL CONTINUE INTO THE 40S BY LATE MORNING WITH A RUN AT 50
WITHIN REACH DURING THE AFTERNOON. THERE REMAINS NO SIGN OF LOW
LEVEL MOISTURE SUFFICIENT FOR STRATUS IN THE LATEST SURFACE
OBSERVATIONS WHICH OPENS THE DOOR FOR A BOOST FROM MARCH SUN AS HIGH
CLOUDS THIN BY EARLY AFTERNOON. SATELLITE IMAGERY INDICATES THE LACK
OF HIGH CLOUDS OVER THE NORTHERN PLAINS AND UPPER MIDWEST AT PRESS
TIME WHICH IS HANDLED WELL BY THE 00Z MODEL PACKAGE OVER THE GREAT
LAKES. MODEL DEPICTIONS ALSO INDICATE THE LOW LEVEL THERMAL RIDGE
SETTLING INTO THE OHIO VALLEY BY EVENING BUT WITH THICKNESS WARMING
OVER LOWER MICHIGAN MATCHING THAT WHICH SUPPORTED MAX TEMPS SOLIDLY
IN THE UPPER 40S OVER THE NORTHERN PLAINS AND UPPER MIDWEST
YESTERDAY DESPITE BOUNDARY LAYER GROWTH LIMITED TO THE 900 MB LEVEL
OR LOWER.

MOSTLY COINCIDENT WITH SUNSET, A WEAK COLD FRONT ASSOCIATED WITH THE
LOW WILL MOVE THROUGH SE MICHIGAN AS THE LOW MAKES IT TO NORTHERN
ONTARIO. COLD ADVECTION IS INDICATED TO BE WEAK BEHIND THIS BOUNDARY
AND THICKENING HIGH CLOUDS WILL HELP MAINTAIN MILD TEMPERATURES WELL
INTO THE NIGHT AND MOSTLY ABOVE FREEZING THROUGH SUNRISE TUESDAY.
THE WEAK FRONT WILL MAKE IT SOUTH OF THE OHIO BORDER WHERE IT WILL
MERGE WITH LOW PRESSURE DEVELOPING IN THE LEE OF THE CENTRAL
ROCKIES. SURFACE CYCLOGENESIS, ALONG WITH IMPROVING UPPER JET
DYNAMICS OVER THE NORTHERN PLAINS AND GREAT LAKES, WILL INDUCE MID
LEVEL FRONTOGENESIS THAT WILL THICKEN CLOUD COVER OVER SE MICHIGAN
DURING THE OVERNIGHT HOURS. THE GFS IS SHOWING ITS WET BIAS BY
BREAKING OUT LIGHT QPF OVER OUR AREA BEFORE 12Z BUT ITS OWN MODEL
SOUNDINGS INDICATE DRY AIR HOLDING TOUGH AROUND 850 MB IN SUPPORT OF
OUR GOING DRY FORECAST THROUGH THE NIGHT.

LONG TERM...TUESDAY THROUGH SUNDAY

AN ENERGETIC AND PROGRESSIVE AMPLIFIED NORTHERN STREAM WILL BRING A
POTENT TROUGH THROUGH THE GREAT LAKES MIDWEEK BRINGING ABOUT BIG
CHANGES IN THE WEATHER. A SPLIT FLOW REGIME WILL PHASE OVER THE
WESTERN OHIO VALLEY WITH THE NORTHERN STREAM TROUGH PICKING UP A
MOIST SOUTHERN STREAM WAVE LATE TUESDAY. AFTER A PERIOD OF RAIN AND
SNOW...THE TROUGH WILL USHER YET ANOTHER VERY COLD AIRMASS INTO THE
STATE BRINGING NEAR ZERO TEMPS BACK INTO THE FORECAST WEDNESDAY
NIGHT...FOLLOWED BY HIGHS IN THE 20S ON THURSDAY. AS QUICKLY AS THE
TROUGH ARRIVES IT WILL DEPART WITH A RIDGE BUILDING IN ON FRIDAY TO
WARM US BACK INTO THE 40S WITH YET ANOTHER TROUGH DURING THE
WEEKEND. PRETTY TYPICAL PATTERN FOR THIS TIME OF YEAR.

THE COLD FRONT THAT MONDAYS CLIPPER DROPPED THROUGH THE STATE WILL
BECOME ORIENTED WITH THE MEAN FLOW AND RATHER DIFFUSE THROUGH THE
DAY TUESDAY AS IT STALLS ACROSS SOUTHERN MI. THIS
BOUNDARY/BAROCLINIC ZONE QUICKLY TRANSITIONS TO A WARM FRONT AS THE
TROUGH AND SHORTWAVE PHASE AND LATCH ONTO IT. CAA NORTH OF THE
BOUNDARY AND SOUTHERLY MOIST FLOW JUST SOUTH OF THE STATE WILL
TIGHTEN UP THE BOUNDARY WHICH SHOWS UP VERY WELL ON 850-700MB THETA
E PLOTS. CROSS SECTIONS SHOW A VERY GOOD...DEEP LAYER OF FGEN AT
850MB NEAR THE OHIO BORDER GENTLY SLOPING UP TO AROUND 600MB OVER
MBS. THIS WILL PRODUCE THE FIRST QUESTION WITH THE FORECAST OF HOW
MUCH QPF WILL BE GENERATED AND WILL IT BE RAIN OR SNOW OR A MIX?
THERMAL PROFILES WILL START OFF WARM 00Z WEDNESDAY WHICH WOULD LEAD
TO RAIN BUT THE CAA WILL EVENTUALLY COOL THE PROFILE ENOUGH TO GET A
CHANGE OVER. AS OF NOW WILL ADVERTISE A FEW HUNDREDTHS OF
QPF...MAINLY RAIN...AS SOME MOISTURE WILL GO INTO SATURATING THE DRY
LAYER LEFT BY THE RIDGE. IF THE COLD AIR CAN SPEED UP BY A FEW HOURS
IT WILL NOT BE OUT OF THE QUESTION TO TURN THAT QPF INTO AROUND AN
INCH OR SO OF SNOW.

MODELS ARE COMING TOGETHER NICELY WITH THE TRACK OF THE STORM WHICH
IS CURRENTLY NE RIGHT ALONG THE OHIO RIVER REACHING THE OH/PA BORDER
AROUND 18Z WEDNESDAY. THIS TRACK PUTS SE MI IN THE FAVORABLE REGION
NORTH AND WEST OF THE CENTER OF THE LOW TO GET ACCUMULATING SNOWFALL
TUESDAY NIGHT THROUGH WEDNESDAY. MODELS ARE TRENDING DOWN WITH QPF
TOTALS IN THE MOST RECENT RUNS...ACTUALLY CLOSER TO MORE REASONABLE
VALUES WHICH IS NICE TO SEE. THE COLD AND DRY AIR FROM THE NORTH
WILL CREATE A PRETTY RAPID DROP OFF IN SNOWFALL TOTALS WHICH LOOKS
TO FALL SOMEWHERE ALONG OR NORTH OF THE I69 CORRIDOR. LOCATIONS TO
THE SOUTH...BETWEEN OHIO AND I96/M59...HAVE SEVERAL FAVORABLE
FACTORS WORKING FOR IT WITH VERY MOISTURE RICH AIR...SPECIFIC
HUMIDITIES AROUND 3 G/KG...EXTENDING UP THROUGH 700MB FOR ONE. GOOD
RIDGE OF THETA E FOLDING ALONG THE FRONT INTO MI AND ALSO THE
AFOREMENTIONED FGEN BAND TO START IT OFF FOLLOWED BY A DECENT AREA
OF DEFORMATION OVER FAR SE LOWER MI. WITH BETTER MODEL CONSISTENCY
AND AGREEMENT WITH LATEST RUNS...ADJUSTED QPF/SNOW AMOUNTS SLIGHTLY
TO BETTER DENOTE THE POSSIBLE NORTHERN EDGE/CUT OFF TO THE NORTH AND
HIGHER AMOUNTS SOUTH OF A LINE FROM ABOUT ADG TO PHN. BEST WINDOW
FOR ACCUMULATING SNOWFALL WILL BE FROM ABOUT 09Z-18Z WEDNESDAY.
CURRENT FORECAST AMOUNTS ARE...UP TO AN INCH FOR THE SAGINAW
VALLEY...1-3 INCHES BETWEEN I69 AND M59 AND 3-5 INCHES FOR THE
SOUTH. JUST TO REITERATE...THERE IS A CHANCE FOR INCH OR SO OF SNOW
LEADING INTO THE EVENT IF THE LEADING FGEN AND COLD AIR CAN ALIGN
THEMSELVES BETTER LIMITING RAIN CHANCES. AND EXPECT FURTHER TRACK
ADJUSTMENTS WHICH MAY SHIFT TOTALS.

THE REST OF THE EXTENDED WILL FEATURE FREQUENT UPS AND DOWN WITH
TEMPERATURES AS PATTERN STAYS AMPLIFIED AND PROGRESSIVE THROUGH THE
WEEKEND. HIGHS WILL RANGE FROM ABOUT 30-40F THIS WEEKEND WITH LOW
UNFORTUNATELY STILL TRYING TO DIP INTO THE SINGLE DIGITS ON
OCCASION.

MARINE...

MODERATE SOUTHWEST WIND WILL HOLD GENERALLY BELOW 25 KNOTS OVER ICE
COVERED SAGINAW BAY AND THE MOSTLY ICE COVERED OPEN WATER OF LAKE
HURON. THE MOST NOTABLE ASPECT OF MARINE CONDITIONS WILL BE THE
MILDER AIR DRAWN INTO THE REGION AS LOW PRESSURE MOVES THROUGH
NORTHERN ONTARIO TODAY FOLLOWED BY COLDER AIR RETURNING DURING
TUESDAY. WIND CONDITIONS WILL THEN WORSEN DURING THE MID WEEK PERIOD
AS A STRONG LOW PRESSURE SYSTEM MOVES THROUGH THE OHIO VALLEY.
NORTHERLY WIND GUSTS COULD APPROACH GALE FORCE WEDNESDAY OVER THE
SOUTH HALF OF LAKE HURON BEFORE HIGH PRESSURE RETURNS THURSDAY.

&&

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

&&

$$

AVIATION.....DT
UPDATE.......DT
SHORT TERM...BT
LONG TERM....DRK
MARINE.......DRK


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