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000
FXUS63 KDTX 170400
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1200 AM EDT THU APR 17 2014

.AVIATION...

//DISCUSSION...

A VERY DRY LOW LEVEL ENVIRONMENT WILL MAINTAIN VFR CONDITIONS
TONIGHT AND THURSDAY.  WINDS WILL FIRMLY HOLD OUT OF THE
EAST-SOUTHEAST AS THE AREA REMAINS BETWEEN EXITING HIGH PRESSURE
AND THE NEXT LOW PRESSURE SYSTEM LIFTING TOWARD THE UPPER
PENINSULA.  SLIGHT INCREASE IN SPEEDS ON THURSDAY AS THE GRADIENT
STRENGTHENS IN ADVANCE OF THE ASSOCIATED COLD FRONT.  THIS FRONTAL
BOUNDARY WILL EASE INTO THE REGION THURSDAY NIGHT.  WINDS BEGIN TO
VEER TOWARD SOUTHERLY UPON THE ARRIVAL TOWARD EVENING.  AN
ACCOMPANYING THICKENING/LOWERING OF CLOUDS THROUGH THIS TIME.

//DTW THRESHOLD THREATS...

* NONE

&&

.PREV DISCUSSION...ISSUED 319 PM EDT WED APR 16 2014

SHORT TERM... TONIGHT

THE REGION OF SNOW NOW EXTENDING ACROSS PORTIONS OF MN/NRN WI/WRN
UPPER MI IS ASSOCIATED WITH A COMPACT MID LEVEL WAVE ROTATING INTO
THE UPPER MIDWEST. THE SFC LOW LOCATED OVER THE NE/IA BORDER WILL
LIFT INTO WRN WISCONSIN BY THURS MORNING AS THE MID LEVEL WAVE LIFTS
UP TOWARD WRN UPPER MI. THE OVERALL TREND WITH THIS SYSTEM THROUGH
THE NIGHT WILL BE FOR GRADUAL WEAKENING AS THE MID LEVEL WAVE
DAMPENS. SOME RADAR RETURNS WITHIN A MID CLOUD DECK HAVE BEEN
ADVANCING ACROSS W-CNTL LOWER MI THIS AFTERNOON. A REGION OF WEAK
ASCENT ALONG THE 285-295K SURFACES IN ADVANCE OF THE MID LEVEL WAVE
IS RESPONSIBLE FOR THESE RETURNS. THUS FAR NO PRECIP HAS BEEN
REPORTED OVER LOWER MI AS A DEPARTING LOW LEVEL ANTICYCLONE IS
SUSTAINING A HEALTHY AMOUNT OF LOW LEVEL DRY AIR. THE ISENTROPIC
ASCENT WILL LARGELY PASS NORTH OF THE TRI CITIES THIS EVENING. A
BROAD REGION OF LOW LEVEL WARM AIR ADVECTION ASSOCIATED WITH THIS
SYSTEM WILL OVERSPREAD SE MI TONIGHT. STRENGTHENING LOW LEVEL SE
FLOW DURING THE NIGHT WILL ACTUALLY SUSTAIN A GOOD DEGREE OF DRY AIR
IN THE LOW LEVELS WHICH WILL KEEP SE MI PRECIP FREE. DESPITE THE
COOL AFTERNOON TEMPS AND VERY LOW SFC DEWPOINTS /IN THE TEENS
ATTM/... THE INCREASING GRADIENT OVERNIGHT /950MB WINDS FORECAST TO
RISE TO 35 KTS/ WILL HINDER THE AMOUNT OF BOUNDARY LAYER DECOUPLING.
THIS REMAINS SUPPORTIVE OF CURRENT FORECAST MIN TEMPS ON THE HIGH
SIDE OF GUIDANCE...MAINLY IN THE LOW 30S.

LONG TERM...THURSDAY THROUGH WEDNESDAY

HIGH PRESSURE WILL SLIDE OFF TO THE EAST AS A WEAKENING LOW PRESSURE
SYSTEM TRACKS ACROSS NORTHERN MICHIGAN. PRECIPITATION ASSOCIATED
WITH THIS LOW WILL REMAIN NORTH OF THE CWA...HOWEVER EXPECT CLOUDS
TO INCREASE OVER SOUTHEAST MICHIGAN ESPECIALLY NORTH OF I-69. AS A
RESULT OF THE INCREASED CLOUD COVER THROUGH THURSDAY...HAVE LOWERED
TEMPS A COUPLE DEGREES /HIGHS EXPECTED IN THE MID TO UPPER 50S/.

A FRONTAL BOUNDARY STILL LOOKS TO IMPACT SOUTHEAST MICHIGAN ON
THURSDAY NIGHT AND INTENSIFY INTO FRIDAY AS A THETA E BOUNDARY
SLIDES ACROSS THE REGION. THIS FRONT WILL BRING RAIN SHOWERS FOR
THURSDAY NIGHT AND FRIDAY. CURRENT MODEL RUNS ARE SHOWING
CONSISTENCY ABOUT THE TIMING OF THIS FRONT AND THEREFORE HAVE BUMPED
POPS UP TO LIKELY FROM THURSDAY NIGHT THROUGH FRIDAY. HIGH
TEMPERATURES ON FRIDAY WILL BE WELL INTO THE MID 50S HOWEVER...COLD
AIR FILTERS IN BEHIND THE FRONTAL PASSAGE. 850 MB TEMPERATURES SHOW
TEMPERATURES DROPPING TEMPERATURES INTO THE 0 C TO -4 C RESULTING IN
SURFACE TEMPERATURES IN THE MID TO LOW 30S ON FRIDAY NIGHT. THE
MAJORITY OF THE PRECIPITATION IS ANTICIPATED TO MOVE OUT OF THE
REGION BY 00Z SATURDAY...BUT ANY LINGERING SHOWERS PRESENT INTO
FRIDAY NIGHT COULD BE A RAIN/SNOW MIX AS THE TEMPERATURES DROP.

SATURDAY WILL BRING A RAPID INCREASE IN H85 TEMPS FROM -2 TO +6 AS
STRONG WAA SETS UP FROM RETURN FLOW. AS HIGH PRESSURE DEPARTS TO THE
EAST...A FRONTAL BOUNDARY AND ELONGATED LOW PRESSURE TROUGH WILL
CROSS THE AREA ON SUNDAY. THE NARROW FRONTAL ZONE AND SURROUNDING DRY
AIR WILL KEEP SHOWERS SPOTTY FOR THE DAY. COLD AIR ADVECTION WILL
ENSUE FOR NEXT WEEK WITH MAINLY DRY CONDITIONS.

MARINE...

HIGH PRESSURE SLIDES EAST TONIGHT AS LOW PRESSURE ENTERS THE WESTERN
GREAT LAKES. WINDS ARE EXPECTED TO REMAIN BELOW 30 KNOTS TONIGHT AND
THURSDAY AS THIS LOW BUILDS OVER THE EASTERN GREAT LAKES. LIGHTER
WINDS WILL RETURN THURSDAY NIGHT INTO FRIDAY AS A COLD FRONT SLOWLY
MOVES THROUGH THE AREA...BRINGING WITH IT A CHANCE OF RAIN AND
POSSIBLY SOME SNOW SHOWERS OVER NORTHERN LAKE HURON. HIGH PRESSURE
RETURNS FOR SATURDAY BEFORE THE NEXT DISTURBANCE IMPACTS THE
NORTHERN GREAT LAKES ON SUNDAY.

&&

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

&&

$$

AVIATION.....MR
SHORT TERM...SC
LONG TERM....RK/MM
MARINE.......RK

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