Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI

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617
FXUS63 KDTX 050454
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1154 PM EST THU FEB 4 2016


.AVIATION...

TRANSIENT SURFACE RIDGE WILL BRING A PERIOD OF FEW-SCT CLOUDS FOR A
FEW HOURS TO START THE FORECAST...BUT LOWER VFR BKN-OVC CIGS WILL
FILTER BACK IN OVERNIGHT AS THIS RIDGE PIVOTS ESE OF THE AREA AND
THE NEXT WEAK TROUGH APPROACHES FROM THE WEST. LOWER VFR TO MVFR
CIGS WILL MOST LIKELY PREDOMINATE THEREAFTER AS THIS SURFACE TROUGH
ENCROACHES ON THE TERMINALS AND THEN PASSES THROUGH THE AREA FRIDAY
EVENING.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN CEILINGS AOB 5KFT AFTER 08Z...HIGH DURING MUCH OF
  FRIDAY.

&&

.PREV DISCUSSION...ISSUED 325 PM EST THU FEB 4 2016

DISCUSSION...

SETUP TODAY PROVED TO BE MORE SUCCESSFUL IN SNOW PRODUCTION THAN
HIRES GAVE IT CREDIT FOR. MID LEVEL TROUGH WAS COLD ENOUGH TO
STEEPEN LAPSE RATES THROUGH A DEEP LAYER FROM THE SFC TO 700MB WHERE
TEMPS DIPPED TO AROUND -20C. ADD TO IT A GOOD PLUME OF MOISTURE OFF
LAKE MI ALREADY IN PLACE ACROSS LOWER MI AND THE STANDARD NARROW
LAKE EFFECT SHOWERS BETWEEN M59 AND I94 QUICKLY BLOSSOMED INTO
WIDESPREAD SHOWERS ACROSS MOST OF SE MI. HIGHLY VARIABLE CONDITIONS
HAVE PERSISTED THROUGH THE DAY WITH VISIBILITIES QUICKLY BOUNCING
FROM 9SM DOWN TO 2SM AND BACK AGAIN. THIS WILL CONTINUE THROUGH THE
EVENING HOURS THOUGH THE MAIN AREA WILL BECOME DISPLACED NORTHWARD
AS RIDGING BUILDS IN FROM THE SOUTH AND WINDS BECOME MORE
SOUTHWESTERLY. RECENT RADAR TRENDS ALREADY SHOW THIS OCCURRING WITH
REFLECTIVITY DECREASING OVER GRR`S AREA AND ACROSS THE OHIO BORDER.
MOST LOCATIONS WILL SEE A HALF INCH OR LESS OF ADDITIONAL
ACCUMULATIONS BY NIGHTFALL.

QUIETER CONDITIONS FOR FRIDAY AS RIDGING ALOFT AND AT THE SFC BUILDS
ACROSS THE REGION. LONGWAVE RIDGE OVER THE WESTERN CONUS WILL
DISPLACE THE REFORMING POLAR JET ACROSS NORTHERN CANADA KEEPING THE
NEXT SYSTEM OVER NORTHERN ONTARIO FRIDAY NIGHT. WEAK TROUGH
EXTENDING SOUTHWARD WILL PASS OVER LOWER MI EARLY SATURDAY MORNING
BUT APPEARS TO BE UNEVENTFUL OVER SEMI. THE BULK OF THE ENERGY TO
OUR NORTH...AND A SMALL VORTICITY MAX BREAKING OFF THE MAIN SYSTEM
LOOKS TO DIG SOUTH THROUGH THE WESTERN GREAT LAKES...WE ARE LEFT IN
A VOID WITH DEEP MID LEVEL DRY LAYER. WILL BE OVERCAST THOUGH DUE TO
UPPER LEVEL SUPPORT FROM THE TROUGH ITSELF. THE JET STRENGTHENS WITH
NORTHWESTERLY FLOW SETTING UP AS THE NEXT SYSTEM ROUNDS THE WESTERN
CONUS RIDGE. THE DEEPENING WAVE OVER THE NORTHERN PLAINS WILL RESULT
IN SHORT WAVE RIDGING OVER MI WHICH WILL KEEP SATURDAY DRY AS WELL.
HIGHS WILL RANGE FROM THE LOW TO MID 30S WITH LOWS FALLING INTO THE
MID 20S.

ABOVE-NORMAL TEMPERATURES SUNDAY AND MONDAY WITH HIGHS IN THE UPPER
30S/LOW 40S WILL TREND TO BELOW-NORMAL BY THE MIDDLE OF NEXT WEEK AS
A DEEP TROUGH AMPLIFIES OVER THE GREAT LAKES. 12Z MODEL SUITE
ADVERTISES POTENTIAL FOR LONG PERIOD OF LIGHT SNOW SUNDAY NIGHT
THROUGH TUESDAY OR WEDNESDAY AS THE 500 MB CLOSED LOW STALLS OVER THE
GREAT LAKES REGION.

MARINE...

FAIRLY LIGHT WINDS WILL CONTINUE THROUGH TONIGHT AS HIGH PRESSURE
EXPANDS INTO THE CENTRAL GREAT LAKES. WEAK LOW PRESSURE TRACKING
ACROSS THE NORTHERN GREAT LAKES WILL THEN CAUSE WINDS TO INCREASE
FROM THE WEST-SOUTHWEST ON FRIDAY...BUT SPEEDS LOOK TO REMAIN 15
KNOTS OR LESS. ANOTHER STRONGER LOW PRESSURE SYSTEM TRACKING THROUGH
ONTARIO SHOULD PROMPT A STRONGER WIND RESPONSE ON SATURDAY. SPEEDS
LOOK TO BE STRONGEST OVER LAKE HURON...WHERE GUSTS UP TO 25 KNOTS
CAN BE EXPECTED. WINDS WILL THEN TURN TO THE NORTHWEST SATURDAY
NIGHT BEFORE TURNING EAST ON SUNDAY IN ADVANCE OF ANOTHER LOW
PRESSURE SYSTEM.

&&

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

$$

AVIATION.....DG
DISCUSSION...DRK/DT
MARINE.......HLO


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



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