000
FXUS63 KDTX 031958
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
258 PM EST TUE MAR 3 2015

.SHORT TERM...TONIGHT

A SOLID 1 TO 3 INCHES OF SNOW FELL ACROSS THE MAJORITY OF
SOUTHEAST MICHIGAN...TOPPED OFF WITH SLEET AND FREEZING RAIN.
MID LEVEL DRY SLOT HAS ARRIVED...EFFECTIVELY PUTTING AN END TO THE
APPRECIABLE PRECIPITATION. WEAK SURFACE LOW NOW PUSHING INTO
NORTHERN LOWER MICHIGAN LATE THIS AFTERNOON AS
UPPER LEVEL SHORTWAVE TRACKS THROUGH THE STRAIGHTS.
SOUTHERLY WINDS ADVECTING MILDER AIR INTO SOUTHERN LOWER
MICHIGAN...AND STILL EXPECTING TEMPS TO REACH AND RISE ABOVE
32 DEGREES DURING THE RUSH HOUR. ALLOWING THE WINTER WEATHER
ADVISORY FOR SOUTHERN FOUR COUNTIES TO EXPIRE AT 4 PM...WITH THE
OTHER ADVISORY HOLDING TIL 7 PM. WEAK SURFACE CONVERGENCE ALONG THE
COLD FRONT THIS EVENING STILL MAY BE SUFFICIENT TO WRING OUT
DRIZZLE/FREEZING DRIZZLE...BUT FOR THE MOST PART...TONIGHT WILL BE
UNEVENTFUL WITH LIGHT WESTERLY POST FRONTAL FLOW AND GRADUALLY
LOWERING TEMPERATURES. DEEPER (925 MB) LOW LEVEL COLD AIR DOES NOT
ARRIVE UNTIL RIGHT AROUND 12Z WEDNESDAY...MAKING MINS A BIT
CHALLENGING...AND FAVOR TEMPS HOLDING IN THE UPPER TEENS FAR
NORTH TO MID 20S SOUTH AS CLOUDS PERSIST OVERNIGHT.

&&

.LONG TERM...WEDNESDAY THROUGH NEXT TUESDAY

THERE HAS BEEN A NOTED TREND TOWARD SLIGHTLY LESS PROGRESSION OF THE
LONG WAVE TROUGH PUSHING INTO THE WESTERN GREAT LAKES WED AND WED
NIGHT. DEEP LAYER FGEN AND MOISTURE WILL STILL RESIDE WELL SOUTH OF
THE STATE...WITH PERSISTENT LOW LEVEL COLD AIR ADVECTION ACROSS
LOWER MI. THE NAM...CANADIAN AND TO SOME EXTENT ECMWF HOLD SOME
LINGERING SFC TROUGHING BACK ACROSS CNTL MI THROUGH WED AFTERNOON
WITH DEEP LAYER W-SW IN PLACE ALOFT. UPSTREAM OBSERVATIONS SUGGEST
THERE WILL BE SOME RESIDUAL LOW LEVEL MOISTURE IN PLACE ACROSS LOWER
MI. THE ADDED LOW LEVEL CONVERGENCE ASSOCIATED WITH THE TROUGH AND
STEEPENING LOW LEVEL LAPSE RATES DUE TO 925-850MB COLD AIR ADVECTION
AND DAYTIME HEATING WILL SUPPORT A SLIGHT CHANCE OF SNOW SHOWERS
ACROSS THE SAGINAW VALLEY AND THUMB WED AFTERNOON. THIS TROUGH AXIS
SHOULD SLIDE SE OF THE FORECAST AREA WED NIGHT ALLOWING LOW LEVEL
COLD AIR TO MAKE A STRONGER PUSH INTO LOWER MI. 850MB TEMPS ARE
STILL EXPECTED TO DROP TO -20 TO -22C BY THURS MORNING. A GOOD DEAL
OF MID/HIGH CLOUDS SHOULD STREAM ACROSS THE FORECAST AREA WED NIGHT
INTO AT LEAST THURS MORNING...TEMPERING WED NIGHT MINS TO THE SINGLE
DIGITS. THE DEEP LAYER COLD AIR WILL PERSIST OVER SE MI INTO EARLY
FRI MORNING...SUPPORTING A CONTINUATION OF WELL BELOW NORMAL TEMPS
AND SUB ZERO WIND CHILLS THURS NIGHT INTO FRI MORNING.

SOME MODEST WARMING WILL OCCUR ON FRIDAY AS THE CORE OF THE ARCTIC
AIR SLIDES EAST. A BROAD LONG WAVE TROUGH WILL REMAIN IN PLACE
ACROSS ERN CANADA AND THE GRT LKS THROUGH THE WEEKEND WHICH WILL
STILL HOLD TEMPS BELOW EARLY MARCH MEANS. NUMEROUS MID LEVEL SHORT
WAVE IMPULSES CONTINUE TO BE SHOWN BY BOTH THE GFS AND ECMWF TO
IMPACT THE REGION FRI THROUGH MON. CONTINUED DIFFERENCES IN TIMING
AND AMPLITUDE AND POOR RUN TO RUN CONTINUITY WITH THESE FEATURES
WILL LIKELY PERSIST FOR SEVERAL MORE MODEL CYCLES. THE AIRMASS
OVERALL WILL BE QUITE DRY...SUPPORTING NOTHING MORE THEN SLIGHT
CHANCE TYPE POPS THROUGH THIS PERIOD ATTM. THE MEDIUM RANGE MODEL
SUITE DO HOWEVER REMAIN CONSISTENT IN SHOWING THE TROUGH-RIDGE
PATTERN OVER NOAM... WHICH HAS BEEN SO DOMINATE THE LAST SEVERAL
WEEKS...BREAKING DOWN NEXT WEEK. THIS SUGGESTS BUILDING HEIGHTS
ACROSS LOWER MI AND THE POTENTIAL FOR A MORE SUBSTANTIAL WARMING
TREND.

&&

.MARINE...

WINDS WILL VEER FROM S-SE TO WEST THIS EVENING AS LOW PRESSURE LIFTS
NORTHEAST OF THE STRAITS REGION. WINDS WILL ACTUALLY WEAKEN DURING
THE FIRST HALF OF THE NIGHT AS SOME RESIDUAL TROUGHING LINGERS OVER
LAKE HURON. WESTERLY WINDS WILL INCREASE EARLY WED MORNING 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 WED AFTERNOON. WINDS WILL THEN DECREASE LATE WED INTO
THURS AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE WEST.

&&

.AVIATION...ISSUED 100 PM EST TUE MAR 3 2015

WIDESPREAD IFR CONDITIONS AS PRECIP TYPES AND CIGS CONTINUE TO
CHANGE THROUGH THE AFTERNOON. THE HEAVIEST PRECIPITATION /SNOW/ IS
NOW EAST OF THE AREA WITH WARMER SFC AIR AND MID LEVEL DRY SLOT
WORKING INTO THE AREA. TEMPS ARE STILL COLD ENOUGH AT THE SFC TO
RESULT IN LIGHT FREEZING RAIN FOR MOST TAF SITES CURRENTLY...BUT
SHOULD BE TRANSITIONING TO RAIN ACROSS DTW/DET/YIP AND POSSIBLY PTK
IN A FEW HOURS AS TEMPS RISE ABOVE 32. UPSTREAM OBS SUGGEST FNT/MBS
WILL HOLD ONTO FREEZING RAIN A BIT LONGER AS THE WARM AIR LIFTS
NORTHWARD. WARM AIR OVER THE SNOWPACK SHOULD PRODUCE SOME BR TONIGHT
WHICH WILL NEED TO BE MONITORED FOR VSBY RESTRICTIONS.
OTHERWISE...CONDITIONS WILL GENERALLY IMPROVE TONIGHT AS THE LOW
PRESSURE SYSTEM LIFTS NORTHEASTWARD AWAY FROM LOWER MI.

FOR DTW...LIGHT FREEZING RAIN WILL CONTINUE FOR A COUPLE MORE HOURS
AS THE +32 DEGREE AIR IS STILL RESIDING IN CENTRAL IL...BUT A
CHANGEOVER TO RA/DZ SHOULD OCCUR LATE THIS AFTERNOON. PRECIP WILL
SHUT OFF THIS EVENING WITH POSSIBLE BR LINGERING INTO THE OVERNIGHT.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS BELOW 5000 FT 06Z TONIGHT...LOWER CONFIDENCE
  THEREAFTER.

* LOW IN VISIBILITY AOB 1/2 MILE IN FOG MID AFTERNOON INTO THE
  EVENING.

* HIGH IN PTYPE AS FZRA THROUGH THIS AFTERNOON...AND RA/DZ THIS
  EVENING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ047>049-
     053>055-060>063-068>070.

     WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MIZ075-
     076-082-083.

LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...SF
LONG TERM....SC
MARINE.......SC
AVIATION.....DRK


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