Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI

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FXUS63 KDTX 041153
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
653 AM EST WED MAR 4 2015


.AVIATION...

MVFR CIGS WILL BE SLOW TO ERODE TODAY...EXPECT PERHAPS MBS/FNT WHERE
COLD FRONT WILL PASS THROUGH AND BRING DRIER NORTHWEST FLOW EARLIER
IN THE DAY. FURTHER SOUTH...CIGS AROUND 2500 FEET WILL GRADUALLY
LIFT TO 3500 FEET OR SO AND TREND TOWARDS BKN AS THIS FRONT CLIPS
THE AREA. VFR CONDITIONS WILL THEN DEVELOP TONIGHT AS A SECONDARY
SURGE OF DRIER...COLDER AIR PUSHES INTO THE AREA AS HIGH PRESSURE
BUILDS IN FROM THE WEST.

FOR DTW...MVFR CEILING WILL LINGER IN ADVANCE OF THE COLD FRONT
BEFORE IMPROVING SLIGHTLY INTO VFR POST FRONT DURING THE MORNING

//DTW THRESHOLD PROBABILITIES...

* HIGH FOR CEILINGS BELOW 5000 FT THROUGH 20Z OR SO.

&&

.PREV DISCUSSION...ISSUED 347 AM EST WED MAR 4 2015

SHORT TERM...TODAY AND TONIGHT

RATHER QUIET WEATHER EXPECTED OVER THE NEXT 24 HOURS. A COLD FRONT
WILL SETTLE THROUGH THE AREA TODAY AND BRING OCCASIONAL FLURRIES TO
PARTS OF THE AREA. THIS ACTIVITY WILL LIKELY BE LIMITED TO THE
NORTHERN SECTIONS OF THE FORECAST AREA AS MINOR UPPER LEVEL SUPPORT
WITH THIS FRONT SHIFTS EAST/SOUTHEAST INTO SOUTHERN ONTARIO WITH
TIME LATE IN THE DAY. OTHERWISE...SKIES WILL GENERALLY BE MOSTLY
CLOUDY AS COLD...CYCLONIC FLOW MAINTAIN UNSETTLED CONDITIONS OVER
THE AREA...WITH CLOUD COVER FURTHER ENHANCED BY MOISTURE STREAMING
FROM LAKE MICHIGAN AS THE AIRMASS BECOMES INCREASINGLY COLD DURING
THE DAY AND LEADS TO SOME LAKE EFFECT/ENHANCED CLOUDINESS.

HIGHS WILL RANGE FROM NEAR 20 OVER THE FAR NORTHERN THUMB/SAGINAW
VALLEY TO THE MID/UPPER 20S SOUTH THROUGH THE I-69 CORRIDOR ON TO
THE OHIO AND MICHIGAN STATE LINE. THESE HIGHS WILL MOST LIKELY COME
IN THE EARLY TO MID AFTERNOON AS INCREASING COLD AIR ADVECTION
DURING THE LAST HALF OF THE DAY CAP THE HIGHS AND LEAD TO SLOWLY
FALLING TEMPERATURES FROM LATE AFTERNOON INTO THE EARLY EVENING.

TEMPERATURES WILL CONTINUE TO DROP INTO TONIGHT AS THE NEXT PIECE OF
ARCTIC AIR DEEPENS OVER THE AREA. AS SURFACE RIDGING ASSOCIATED WITH
THIS AIRMASS SHIFTS INTO THE AREA...SOME GRADUAL CLEARING OF SKIES
CAN BE EXPECTED...ESPECIALLY OVER NORTHERN SECTIONS OF THE REGION.
THIS WILL ALLOW TEMPERATURES TO DROP TO ZERO OR SLIGHTLY BELOW IN
MANY LOCATIONS ALONG AND NORTH OF I-69 WITH SINGLE DIGITS ABOVE ZERO
THE RULE FURTHER TO THE SOUTH. THE FRESH SEVERAL INCHES OF SNOW WILL
ALSO ASSIST IN RADIATIVE COOLING AND PROMOTE THESE COLDER MINIMUM
TEMPERATURES. WILL MAINTAIN THE FORECAST M-59 SOUTH...BUT SHAVE A
FEW DEGREES OFF OF LOWS FURTHER NORTH GIVEN THIS EXPECTATION. THIS
WILL BRING WIND CHILLS DOWN TO 10 BELOW OR LESS IN SPOTS...BUT NOT
QUITE TO THE ADVISORY CRITERION OF 15 BELOW...AT LEAST NOT IN A
WIDESPREAD AND PERSISTENT MANNER.

LONG TERM...THURSDAY THROUGH TUESDAY

SOUTHEASTERN MICHIGAN WILL REMAIN UNDER THE GRIPS OF THE LARGE
WAVLENGTH UPPER LEVEL TROUGH THROUGH THE UPCOMING WEEKEND...POSSIBLY
BREAKING DOWN SOMETIME NEXT WEEK. THIS WILL LEAD TO A CONTINUATION
OF BELOW NORMAL TEMPERATURES THURSDAY AND FRIDAY BEFORE MODERATING
THIS WEEKEND. THE FIRST TWO ITEMS TO NOTE ARE THE FORECASTED LOW
TEMPERATURES FRIDAY MORNING AROUND ZERO...AND THE POTENTIAL FOR
WINDCHILLS FRIDAY MORNING TO RANGE BETWEEN 8 AND 18 DEGREES BELOW
ZERO. THE NEXT FORECAST ITEM OF NOTE IS THEN BRISK SOUTHWESTERLY
FLOW SETTING UP OVER ALL OF SOUTHEASTERN MICHIGAN DUE TO RETURN FLOW
KICKING IN ON THE COLD/NORTHERN PERIPHERY OF THE SURFACE
ANTICYCLONE. DESPITE LOW MIXING HEIGHTS DUE TO HIGH STABILITY...THIS
IS A CLASSIC SETUP FOR A SIGNIFICANT GRADIENT FLOW SETUP. WINDSPEEDS
FRIDAY AFTERNOON ARE EXPECTED TO REACH THE 20 TO 30 MPH...HIGHER END
OF THE RANGE ACROSS THE NORTHERN CWA. WARM ADVECTION CLOUDS ARE THEN
FORECASTED TO RETURN FRIDAY NIGHT AHEAD OF THE CLIPPER SYSTEM THAT
WILL DIVE ACROSS THE REGION ON SATURDAY. MODELS HAVE BEEN VERY
PERSISTENT IN THE OVERALL SHARP MIDLEVEL TROUGH THAT WILL ACCOMPANY
THE SHORTWAVE ENERGY WHICH INCREASES THE POTENTIAL FOR BOTH
TEMPERATURES TO CLIMB ABOVE THE FREEZING MARK SATURDAY AND SOME
INCREASED PRECIPATION CHANCES. THATS ABOUT IT FOR THE INCREASING
CONFIDENCE AS TIMING...PLACEMENT...STRUCTURE DIFFERENCES CONTINUE TO
EXIST IN REGARDS TO THE CLIPPER SYSTEM.

MARINE...

WESTERLY WINDS WILL INCREASE EARLY TODAY AS ANOTHER SURGE OF ARCTIC
AIR ADVANCES INTO THE REGION. THE WINDS SHOULD BE STRONGEST ACROSS
NORTHERN LAKE HURON AS SOME DEGREE OF LINGERING SURFACE TROUGH IS
EXPECTED ACROSS THE SOUTHERN HALF OF THE LAKE INTO THIS AFTERNOON.
WINDS WILL THEN DECREASE LATE WED INTO THURS AS HIGH PRESSURE BUILDS
INTO THE REGION FROM THE WEST. MAIN ITEM TO NOTE WITH THIS MARINE
PACKAGE IS STRONG SOUTHWESTERLY WINDS DEVELOPING OVER THE GREAT
LAKES FRIDAY ON THE NORTHWEST PERIPHERY OF THE SURFACE HIGH. CURRENT
INDICIATIONS ARE WINDSPEEDS MAY REACH THE 30 TO 40 KNOT RANGE DURING
THE AFTERNOON HOURS.

&&

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

$$

AVIATION.....DG
SHORT TERM...DG
LONG TERM....CB
MARINE.......CB


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



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