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000
FXUS63 KAPX 200726
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
326 AM EDT SUN APR 20 2014

.SYNOPSIS...
ISSUED AT 326 AM EDT SUN APR 20 2014

LOW PRESSURE PASSING WELL NORTH OF MICHIGAN TODAY WILL DRAG A COLD
FRONT INTO NORTHERN MICHIGAN. THAT FRONT WILL STALL OVER NORTHERN
MICHIGAN...LEADING TO A PERIOD OF DAMP WEATHER THAT WILL LAST
THROUGH MONDAY NIGHT. TEMPERATURES WILL BE RELATIVELY MILD TODAY AND
MONDAY...THEN COOL OFF AGAIN ON TUESDAY.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 326 AM EDT SUN APR 20 2014

CURRENTLY, INTERESTING SET UP AS THE 500 MB JET IS OVER THE UPPER
GREAT LAKES ORIENTED ROUGHLY WEST TO EAST WITH THE SOUTHERLY SFC
FLOW OVER THE STATE. THIS HAS SET UP A BAROCLINIC ZONE THAT IS SET
TO SHARPEN AND SLOWLY SINK SOUTH OVER THE NEXT 24 HOURS. AHEAD OF
THIS SYSTEM IS A FAIR AMOUNT OF DRY AIR AT THE SFC AND AT 850 MB.
MAIN CONCERN IS THE TIMING OF THE PRECIPITATION AND THE POSSIBILITY
OF FREEZING PRECIPITATION OVER THE NEXT FEW HOURS IN E UPPER.

TODAY...WITH THE RADAR SHOWING SOME SOUTHERN DEVELOPMENT AHEAD OF
THE MAIN RAIN IN UPPER MICHIGAN, IN N LAKE MICHIGAN AND NW LOWER,
THINK THAT THE TIMING WHILE A TOUCH SLOWER IS LOOKING PRETTY GOOD.
SEEMS THAT THE ECMWF QPF FIELD MAY HAVE THE BETTER HANDLE ON THE
SPEED OF THIS SYSTEM, AS THE GFS HAS MORE DRY AND IS A BIT SLOWER
THAN ECMWF, AND THE NAM IS EVEN SLOWER WITH THE RAIN NOT EVEN
GETTING INTO NW LOWER UNTIL AFTER 12Z. SO HAVE LEANED TOWARD THE
ECMWF TIMING OVER THE DAY AS THE BEST PRECIPITATION LOOKS TO BE
FOCUSED NEAR THE STRAITS OVER THE NEXT COUPLE OF HOURS, AND THEN
SLIDING SOUTH AFTER 12Z. BY 18Z THE SFC GRADIENT RELAXES AND SO THAT
THE DIFFERENTIAL ADVECTION DIMINISHES. HOWEVER, THAT WILL PROBABLY
ONLY DIMINISH THE INTENSITY OF THE RAIN. AS A WHOLE IT WILL REMAIN
LIKELY THAT A GOOD PORTION OF N LOWER WILL END UP WITH MEASURABLE
RAIN.

TONIGHT...THE GFS BEGINS TO PULL MORE IN LINE WITH THE ECMWF AS THE
FRONT LAYS OUT OVER N LOWER. A STRONGER 500 MB SHORTWAVE TROUGH
BEGINS TO PUSH OUT OF THE PLAINS AND INTO THE UPPER GREAT LAKES BY
06Z, WHICH THEN BEGINS TO REORGANIZE THE RAIN ALONG THE FRONT AGAIN.
IT LOOKS LIKE, DEPENDING ON THE MODEL THAT IS RIGHT THAT THERE COULD
BE ANOTHER 0.50" OF RAIN OR MORE, ALTHOUGH, THE GFS LOOKS A LITTLE
LIKE IT IS CONVECTIVELY OVER DRIVEN AS THE SFC PRESSURE LOOK A BIT
TOO OVERDEVELOPED.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 326 AM EDT SUN APR 20 2014

MONDAY AND TUESDAY...SURFACE LOW DEVELOPS OVER THE UPPER MISSISSIPPI
VALLEY ALONG THE STATIONARY FRONT JUST AHEAD OF A SHARP UPPER LEVEL
TROUGH. THIS LOW WILL TRACK THRU NRN MICHIGAN MONDAY INTO MONDAY
EVENING... SHIFTING EAST OF OUR STATE LATE MONDAY NIGHT. ANOTHER
AREA OF ENHANCED PRECIP WILL DEVELOP WEST OF OUR CWA AS THIS SURFACE
LOW DEEPENS...TRACKING OVER MAINLY NRN LWR MICHIGAN DURING THE DAY
AND EARLY EVENING. NO DOUBT PRECIP WILL BE ALL LIQUID WITH MONDAY
AFTERNOON HIGHS RANGING FROM THE LOWER 50S IN ERN UPR MICHIGAN TO
THE UPPER 60S IN OUR FAR SE CWA (COOLER NEAR THE LAKES). WILL
MAINTAIN LIKELY POPS FOR ALL OF NRN LWR MICHIGAN MONDAY...TAPERING
TO CHANCE POPS FOR ERN UPR MICHIGAN AS THIS AREA WILL LIKELY BE
NORTH OF THE DEEPER MOISTURE AND BETTER LOW LEVEL CONVERGENCE ALONG
THE BOUNDARY. SURFACE LOW WILL FURTHER DEEPEN AS IT EXITS EAST INTO
ONTARIO AND QUEBEC MONDAY NIGHT INTO TUESDAY. PRECIP CHANCES WILL
TAPER OFF FROM WEST TO EAST AS CAA KICKS IN ON THE BACK SIDE OF THE
DEPARTING LOW. STILL APPEARS THAT PRECIP WILL COME TO AN END BEFORE
CAA BRING PRECIP TYPE INTO QUESTION. LOW TEMPS MONDAY NIGHT WILL
RANGE FROM THE MID 30S IN ERN UPR MICHIGAN TO THE LOWER 40S NEAR
SAGINAW BAY. TUESDAY AND TUESDAY NIGHT WILL BE DRY WITH A GRADUAL
DECREASE IN CLOUDS AS STRONG HIGH PRESSURE...SUBSIDENCE AND DRY AIR
THRU THE COLUMN BUILD INTO MICHIGAN. HIGH TEMPS TUESDAY AFTERNOON
WILL WARM INTO THE LOWER 40S TO LOWER 50S...WITH OVERNIGHT LOWS
FALLING MAINLY INTO THE MID 20S TO LOWER 30S.

WEDNESDAY THRU SATURDAY...HIGH PRESSURE AND DRY AIR REMAIN IN
CONTROL THRU WEDNESDAY...MAINTAINING DRY WX INTO WEDNESDAY NIGHT.
OUR NEXT CHANCE OF PRECIP WILL DEVELOP THURSDAY AS LOW PRESSURE
DEEPENS OVER THE UPPER MISSISSIPPI VALLEY AND SLOWLY CHURNS ITS WAY
THRU NRN MICHIGAN DURING THE LAST PART OF THE WEEK. SYSTEM BECOMES
VERTICALLY STACKED...THUS THE SLOW EASTWARD PROGRESS. AHEAD OF THIS
SYSTEM...MOISTURE AND LIFT (AND THUS PRECIP) WILL ARRIVE IN A SERIES
OF WAVES. THE DEEPEST MOISTURE WILL REMAIN NORTH AND WEST OF THE LOW
CENTER...WHICH AT THIS POINT IS EXPECTED TO TRACK JUST NW OF OUR
CWA. FOR NOW...WILL MAINTAIN HIGH CHANCE/LOW LIKELY POPS FOR
VIRTUALLY ALL OF OUR CWA THURSDAY THRU SATURDAY. PRECIP TYPE SHOULD
BE ALL RAIN AHEAD OF THE LOW PER TEMP PROFILES...WITH SOME SNOW
MIXING WITH THE RAIN FRIDAY NIGHT ACROSS OUR NRN CWA AS THE SURFACE
LOW PUSHES EAST OF OUR CWA AND LOW LEVEL CAA COMMENCES. TEMPS WILL
SLOWLY BUT STEADILY WARM THRU MUCH OF THE WEEK...WITH HIGH TEMPS IN
THE MID 40S TO LOWER 50S ON WEDNESDAY WARMING WELL INTO THE 50S TO
AROUND 60 BY FRIDAY AHEAD OF THE COLD FRONT. HIGH TEMPS ON SATURDAY
WILL DROP BACK INTO THE 40S BEHIND THE DEPARTING LOW IN CAA.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 123 AM EDT SUN APR 20 2014

SUMMARY: A COLD FRONT WILL STALL OVER NORTHERN MICHIGAN OVERNIGHT
AND THROUGH THE DAY ON SUNDAY WITH DETERIORATING FLYING CONDITIONS
EXPECTED.

RESTRICTIONS: OVERALL..CONDITIONS LOOKING A LITTLE MORE OPTIMISTIC
FOR THE DAY SUNDAY THAN SIX HOURS AGO BASED ON EVENING MODEL
EXPECTATIONS.  ONLY TERMINAL IMPACTED THROUGH EARLY SUNDAY SHOULD BE
PLN...WITH A DETERIORATION TO MVFR/IFR RESTRICTIONS BY DAYBREAK WITH
RA DEVELOPING.  EXPECT THAT IT WILL TAKE MOST OF THE DAY FOR THIS
RAINFALL TO MAKE IT FAR ENOUGH SOUTH THE IMPACT THE OTHER
TERMINALS...LIKELY NOT UNTIL AFTER 18Z TVC/APN AND EVEN LATER AT
MBL. SOME MVFR RESTRICTIONS DUE TO CIGS AND VSBYS LIKELY AT THESE
SITES BY SUNDAY EVENING...WITH MBL STILL LOOKING TO HOLD ONTO VFR
CONDITIONS THROUGH 06Z MONDAY.

WINDS: SOUTHEAST WINDS WILL CONTINUE 5-10KTS FOR THE OVERNIGHT.
WINDS WILL VEER SOUTHERLY BY SUNDAY MORNING AROUND 10KTS BEFORE
CONTINUING TO VEER SOUTHWESTERLY 10KTS FOR THE DAY ON SUNDAY.
SUNDAY EVENING WINDS WILL DIMINISH TO LIGHT AND VARIABLE.

LLWS /CONFIDENCE: HIGH/: SOUTHERLY WINDS IN THE 0.5-1.5KFT LAYER ARE
NOW REACHING 30-35KTS AND THIS LLWS WILL CONTINUE THROUGH THE OVERNIGHT
WITH SHEAR LAYER WINDS GRADUALLY VEERING MORE SOUTHWESTERLY BY
SUNDAY MORNING. EXPECT SHEAR LAYER TO MIX OUT DURING THE MORNING
SUNDAY.

THUNDER: NO THREAT THIS CYCLE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.

&&

$$

SYNOPSIS...MR
SHORT TERM...JL
LONG TERM...MR
AVIATION...ARNOTT