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000
FXUS63 KAPX 281947
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
347 PM EDT MON JUL 28 2014

.SYNOPSIS...
ISSUED AT 347 PM EDT MON JUL 28 2014

LOW PRESSURE IN THE EASTERN GREAT LAKES WILL CONTINUE TO MOVE EAST
AND THEN NORTH...REACHING NORTHERN QUEBEC ON WEDNESDAY. WE WILL
REMAIN IN THE BACKWASH OF THIS SYSTEM ALL WEEK...KEEPING OUR WEATHER
ON THE COOL SIDE...AND PROVIDING US WITH OCCASIONAL CHANCES FOR
SCATTERED SHOWERS.

&&

.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 347 PM EDT MON JUL 28 2014

...OUT-AND-IN CLOUDS THIS EVENING WITH A SHOWER OR TWO OVERNIGHT...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: AFTERNOON SURFACE ANALYSIS SHOWS UPPER
GREAT LAKES IN BETWEEN LOW PRESSURE OVER THE NORTHEASTERN U.S. AND
HIGH PRESSURE ACROSS THE PLAINS/MIDWEST.  NORTHWEST FLOW ALOFT INTO
THE REGION WITH WATER VAPOR IMAGERY SHOWING A SHORT WAVE TROUGH
DIGGING SOUTHEAST OUT OF NORTHWEST ONTARIO AND TOWARD ISLE ROYALE
WITH A SMALL PATCH OF COLDER CLOUD TOPS WITH IT AND SOME SPOTTY RAIN
SHOWERS.  THERE IS ADDITIONAL CLOUD COVER NORTH OF THIS FEATURE AS
WELL ADVECTING SOUTHWARD.  CLOSER TO HOME...PLENTY OF CLOUD COVER
THIS AFTERNOON ACROSS NORTHERN LOWER WITH PERSISTENT
STRATOCUMULUS...SOME OF IT LAKE-AIDED THIS MORNING WITH A FEW
STREAMERS OF DRIZZLE...AND DIURNALLY-AIDED DURING THE AFTERNOON.
CLOUDS OVER EASTERN UPPER CONFINED TO EAST OF THE I-75 CORRIDOR
WITH A GOOD DEAL OF AFTERNOON SUN ACROSS WESTERN CHIPPEWA/MOST OF
MACKINAC COUNTIES.

DEEP LAYER NORTH/NORTHWEST FLOW EXPECTED THROUGH THE NIGHT...SHORT
WAVE TROUGH APPROACHING WESTERN LAKE SUPERIOR EXTRAPOLATES INTO
NORTHWEST LOWER IN THE 02Z-03Z TIME FRAME...WITH ANOTHER MID LEVEL
WAVE MOVING INTO THE FORECAST AREA OVERNIGHT ALONG WITH INCREASING
MOISTURE.

PRIMARY FORECAST CONCERNS: CLOUDS AND PRECIPITATION CHANCES THE MAIN
ISSUES GIVEN WEAK FEATURES WITHIN NORTHWESTERLY FLOW ALOFT DROPPING
INTO THE REGION TONIGHT.

TONIGHT...SORT OF A NEBULOUS FORECAST FOR TONIGHT WITH SOME WEAK
FEATURES AND INCREASING MOISTURE (PLUS A LITTLE MID LEVEL
INSTABILITY) COMBINING TO BRING A MOSTLY NUISANCE SHOWER THREAT TO
NORTHERN MICHIGAN TONIGHT.  CLOUD COVER WILL BE IN FLUX HEADING INTO
THIS EVENING...AS STRATOCUMULUS OVER NORTHERN LOWER GETS PUSHED
SOUTHEAST BY BACKING LOW LEVEL WINDS...AND CLOUD DECK HEADING TOWARD
LAKE SUPERIOR DRIFTS SOUTH.  VORTICITY CENTER HEADING TOWARD ISLE
ROYALE WILL LIKELY TRACK TOWARD NORTHWEST LOWER MICHIGAN THIS
EVENING...NOT GOING TO RULE OUT THAT IT STILL WON`T HAVE A FEW RAIN
DROPS WITH IT AROUND THE GRAND TRAVERSE BAY REGION TOWARD MIDNIGHT.
OTHERWISE...WEAK TROUGH AT 850/700MB ROTATES IN OVERNIGHT ALONG WITH
SOME MID LEVEL COOLING/STEEPENING OF LAPSE RATES BELOW 700MB.  SO
CAN`T RULE OUT A FEW SPOTTY SHOWERS WITH THESE FEATURES DURING THE
NIGHT.  DON`T THINK IT WILL BE COLD ENOUGH FOR A SIGNIFICANT LAKE
CONTRIBUTION TO PRECIPITATION CHANCES EXCEPT PERHAPS THROUGH THE
STRAITS VICINITY.  OVERNIGHT LOWS MAINLY UPPER 40S-LOWER 50S.

&&

.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 347 PM EDT MON JUL 28 2014

...A STUCK UPPER LEVEL LOW...

OVERVIEW...THE 500 MB LOW THAT HAS BEEN JUST EAST OF HUDSON BAY WILL
CONTINUE TO SPIN OVER THE AREA, UNTIL CLOSE TO THE WEEKEND. THAT`S
WHEN THE LOW IS EXPECTED TO FILL AND LIFT OUT OF CANADA FOR A MORE
PROGRESSIVE PATTERN AGAIN. THE 500 MB PATTERN OVER THE CONUS IS
FAIRLY AMPLIFIED, WITH A 500 MB RIDGE OVER THE PLAINS. JUST TO THE
WEST OF THE RIDGE OUT OVER THE GULF OF ALASKA IS ANOTHER 500 MB LOW.
AT THIS POINT IT LOOKS LIKE THE BLOCK WILL LAST A FEW DAYS. SO WITH
THE IN MIND THE FORECAST LOOKS LIKE THIS...

(7/29)TUESDAY...MOISTURE IN THE 700-500 MB LAYER AND AT 850 MB WILL
CONTINUE TO ROTATE AROUND THE 500 MB LOW AS IS SINKS A BIT SOUTH AND
WEST TOWARD THE UPPER GREAT LAKES. NOT TO MENTION WITH THE MOISTURE,
THAT THERE ARE SEVERAL PIECES OF ENERGY ROTATING AROUND THE LOW AS
WELL. THIS SHOULD KICK OFF SHOWERS AT THE VERY LEAST. ALTHOUGH THE
GFS BOUNDARY LAYER CAPE IS A FEW HUNDRED J/KG, SO WILL EXPECT THAT
THUNDER WILL WORK ITS WAY INTO THE REGION THROUGH THE MORNING HOURS
AND THE AFTERNOON. 0-6KM SHEAR WILL BE BELOW 30 KNOTS, SO WON`T BE
EXPECTING ANY GOOD ORGANIZATION WITH THESE.

TUESDAY NIGHT...IT LOOKS LIKE THE LAPSE RATES STABILIZE (LIS>0C)
AFTER 00Z, SO THE RAIN SHOWERS WILL DIMINISH WITH ONLY A FEW SHOWERS
IN THE SE COUNTIES IN THE EARLY EVENING. THIS WILL LEAVE THE
OVERNIGHT DRY AHEAD OF THE NEXT PIECE OF ENERGY TO MOVE SOUTH INTO
THE REGION.

(7/30)WEDNESDAY...INHERITED 30 POPS IN E UPPER AND THE SE COUNTIES
OF N LOWER, BUT WAS A LITTLE CONCERNED WITH THE GFS AND THE ECMWF
SHOWING THE 500 MB JET MAX NOSING INTO N LOWER BY 00Z. HOWEVER, WITH
THE 700-500 MB LAYER RH AROUND 20-30% NOSING INTO N LOWER AS WELL,
WILL LEAVE THE POPS AS IS FOR NOW AS THE WE LOOK AT ANOTHER RUN.

WEDNESDAY NIGHT...WILL LEAVE THE EVENING DRY AS THE MOISTURE SLOWLY
INCREASES, BUT NOT EXPECTING IT TO MOISTEN "ENOUGH" FOR SHOWERS
UNTIL AFTER 06Z. THE 500 MB JET MAX WILL BE MOVING THROUGH THE
REGION SO WILL HAVE THE SHOWERS OVERNIGHT.

(7/31)THURSDAY...THE 500 MB SHORTWAVE TROUGH MOVES THROUGH, DURING
THE MORNING SO WILL HAVE THE SMALL CHANCES FOR RAIN SHOWERS AS THE
FEATURE MOVES OUT OF THE FORECAST AREA DURING THE AFTERNOON.
OVERNIGHT, DRY AIR (700-500 MB LAYER RH DROPS TO LESS THAN 40%),
MOVES INTO THE REGION WITH THE ECMWF AND THE GFS, AND ON THE GFS AT
850 MB AS WELL. SO WILL BEGIN TO DRY THINGS OUT.

EXTENDED (FRIDAY THROUGH MONDAY)...(8/1)FRIDAY...ANOTHER 500 MB
TROUGH AND A SFC LOW MOVE THROUGH THE REGION, AND KICKS OFF ANOTHER
ROUND OF THUNDERSTORMS DURING THE DAY. THEN DRY AIR PUSHES BACK INTO
THE REGION AND DIMINISHES THE RAIN AGAIN. (8/2)SATURDAY...WITH THE
TEMPERATURES WARMING INTO THE MID TO UPPER 70S, MOISTURE INCREASING,
A 500 MB TROUGH OVER THE REGION, AND WHAT LOOKS LIKE A WARM FRONT
NEARBY, WILL GO WITH THE CHANCE OF THUNDERSTORMS FOR THE AFTERNOON.
WITH THE DIURNAL HEATING GONE, WILL EXPECT THAT THE SHOWERS AND
THUNDERSTORMS WILL AS WELL. (8/3)SUNDAY...MODELS ARE TRYING TO BRING
A COLD FRONT THROUGH THE REGION. WILL LEAVE THE SHOWERS FOR MAINLY
SUNDAY NIGHT, BUT MIGHT HAVE TO GO WITH THUNDERSTORMS AS THE
SCENARIO BECOMES A LITTLE MORE CLEAR. (8/4)MONDAY...MODELS ARE
HAVING A DISCREPANCY, WITH THE GFS CONTINUING WITH THE RAIN, AND THE
ECMWF MAINLY DRY. SO WILL KEEP THE CHANCE POPS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 156 PM EDT MON JUL 28 2014

MOSTLY VFR CEILINGS EXPECTED THIS AFTERNOON AND TONIGHT...WITH AN
INCREASED CHANCE FOR RAIN SHOWERS BY DAYBREAK TUESDAY.

&&

.MARINE...
ISSUED AT 347 PM EDT MON JUL 28 2014

AS HIGH PRESSURE BUILDS INTO THE UPPER GREAT LAKES TONIGHT,
EXPECT THE WINDS TO DIMINISH OVER THE GREAT LAKES. THEN WITH THE
LACK OF GRADIENT OVER THE UPPER GREAT LAKES FOR THE NEXT COUPLE OF
DAYS, THE WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT CRITERIA
THROUGH THE PERIOD.

&&

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

&&

$$

SYNOPSIS...KB
SHORT TERM...JPB
LONG TERM...JSL
MARINE...JSL