000
FXUS63 KAPX 171508
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1108 AM EDT MON JUN 17 2013

.SYNOPSIS...
ISSUED AT 416 AM EDT MON JUN 17 2013

A WEAK WEATHER SYSTEM WILL CONTINUE TO MOVE ACROSS THE REGION TODAY
RESULTING IN MORE HUMID CONDITIONS ALONG WITH A FEW THUNDERSTORMS. A
LARGE AREA OF HIGH PRESSURE WILL THEN MOVE INTO THE GREAT LAKES AND
UPPER MIDWEST TONIGHT...AND HOLD ACROSS THE AREA THROUGH WEDNESDAY.
THIS PATTERN WILL GENERATE ABUNDANT SUNSHINE ALONG WITH SEASONABLY
COOL TEMPERATURES.

&&

.UPDATE...
ISSUED AT 1108 AM EDT MON JUN 17 2013

13Z SURFACE/COMPOSITE ANALYSIS SHOWS A COLD FRONT ARCING WESTWARD
FROM QUEBEC WESTWARD ACROSS CENTRAL LOWER MICHIGAN THEN BACK
NORTHWEST ACROSS WISCONSIN/NORTHERN MINNESOTA...SANDWICHED BETWEEN
HIGH PRESSURE CENTERS OVER NORTHWEST ONTARIO AND WEST VIRGINIA.
CLOUD COVER MOST PREVALENT ACROSS EASTERN UPPER AND NORTH OF M-72 IN
NORTHERN LOWER MICHIGAN WITH LOWER CEILINGS ACROSS EASTERN UPPER AND
THE TIP OF THE MITT COUNTIES...THOUGH DRY AS OF LATE MORNING WITH A
SMALL CLUSTER OF THUNDERSTORMS COMING OFF THE DOOR PENINSULA.
THICKER CLOUD COVER AND SPOTTY SHOWERS ACROSS NORTHWEST MINNESOTA
AND EXTENDING INTO WESTERN UPPER ALONG WELL DEFINED 850MB TROUGH
AXIS.  WATER VAPOR IMAGERY SHOWS A COUPLE OF MID LEVEL VORTICITY
CENTERS HEADING EAST-SOUTHEAST...ONE OVER NORTHERN WISCONSIN AND A
SECOND OVER WESTERN MINNESOTA.

LEAD VORTICITY CENTER OVER WISCONSIN TIMES INTO NORTHWEST LOWER IN
THE 19Z-20Z TIME FRAME.  MODIFIED 12Z APX SOUNDING FOR 73/54 YIELDS
AN UNCAPPED 600-700J/KG MLCAPE...SO NOT REASONABLE TO THINK WE COULD
END UP WITH 500-1000J/KG MLCAPE SOUTH OF M-72 WHERE BEST HEATING
CURRENTLY OCCURRING AND TEMPERATURES ARE ALREADY IN THE 70S IN
SPOTS.  CLOUD COVER FARTHER NORTH WILL LIMIT INSTABILITY...BUT AREA
OF "COLDER" CLOUD TOPS SPREADING SOUTHEAST FROM WESTERN UPPER SHOULD
REACH NORTHWEST LOWER BY LATE IN THE DAY.  SO WILL PLAY THE RAIN
CHANCES MOSTLY CVX-GLR-APN AND SOUTH...WITH THUNDER CHANCES WHERE
HEATING CURRENTLY OCCURRING.  THINK EASTERN UPPER AND THE TIP OF THE
MITT MOSTLY LIKELY TO REMAIN DRY BUT CLOUD COVER WILL BE A
NUISANCE (AS WELL AS TEMPERATURES).

UPDATE ISSUED AT 913 AM EDT MON JUN 17 2013

12Z MESOANALYSIS SHOWS A COLD FRONT DRAPED ACROSS CENTRAL LOWER
MICHIGAN.  BAND OF POST-FRONTAL RAIN SHOWERS MOVING OUT OF THE
SOUTHEAST CORNER OF THE FORECAST AREA...WITH A FEW SPITS OF PRECIP
BACK ACROSS NORTHERN LAKE MICHIGAN/GREEN BAY.  LOW CLOUDS PRESSING
SOUTH ACROSS EASTERN UPPER AND TIP OF THE MITT COUNTIES.  12Z APX
SOUNDING IS MOIST WITH DEW POINT DEPRESSIONS AT OR BELOW 5C FROM THE
BOUNDARY LAYER UP TO 500MB.  WATER VAPOR IMAGERY SHOWS A TRAIN OF
SMALL ROLL-UPS/VORTICITY CENTERS...ONE HEADING TOWARD THE THUMB AND
CARRYING THE REMAINING CENTRAL LOWER RAIN SHOWERS WITH IT...ANOTHER
OVER CENTRAL LAKE MICHIGAN AND A THIRD IN THE VICINITY OF THE
MINNESOTA/WISCONSIN BORDER.

EARLY FORECAST CHANGES WILL BE TO DOWNPLAY RAIN CHANCES THROUGH THE
REST OF THE MORNING BASED ON CURRENT TRENDS...AS WELL AS SKY COVER
TO ALLOW FOR SOME MORE SUN SOUTH OF M-72 THIS MORNING.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 416 AM EDT MON JUN 17 2013

NORTHERN LAKES CONTINUE TO LIE UNDER A RATHER ROBUST MID LEVEL FLOW
PATTERN...CENTERED NICELY BETWEEN EASTERN CANADA TROUGHING AND
ELONGATED INTERMOUNTAIN WEST/SOUTHERN PLAINS RIDGING. SHEAR AXIS
BETWEEN THIS TWO ENTICING QUITE THE WAVE TRAIN OF ENERGY
COUPLETS...ONE PIVOTING THROUGH THE AREA NOW...WITH ANOTHER UPSTREAM
ENTERING NORTHWEST MINNESOTA. A RATHER RESPECTABLE MOISTURE AXIS IS
COLLOCATED WITH THE ABOVE FEATURES...ALTHOUGH AGGRESSIVE DRYING IS
DIGGING SOUTH JUST NORTH OF LAKE SUPERIOR. SURFACE FEATURES NOTHING
TO WRITE HOME ABOUT...WITH WEAK TROUGHING/COOL FRONT SLOW SAGGING
SOUTH ACROSS UPPER MICHIGAN AS WEAK LOW PRESSURE PULLS OFF INTO
QUEBEC. COMBINATION OF MOISTURE AND SHORTWAVE ENERGY CONTINUES TO
SPARK A FEW SHOWERS ACROSS THE AREA...WITH LOSS OF LATE AFTERNOON
INSTABILITY HELPING KEEP THINGS ON THE LIGHT SIDE. FORECAST CONCERNS
CENTER ON ADDITIONAL SHOWER AND STORM CHANCES TODAY...WITH
TEMPERATURE AND CLOUD TRENDS THROUGH TONIGHT ALSO NEEDING ADDRESSING.

SEVERAL FACTORS TO WORK IN TANDEM TODAY TO BRING A GOOD BET FOR SOME
ADDITIONAL RAINS. EXPECT AT LEAST SCATTERED LIGHT SHOWERS TO
CONTINUE THROUGH THE MORNING AS SOUTHWARD SAGGING SURFACE FRONT
INTERACTS WITH DEEPER MOISTURE PLUME...WEAK MID LEVEL
SUPPORT...AND SOME FGEN DYNAMICS. ATTENTION THEN TURNS TO DIURNAL
ENHANCEMENT OF SHOWERS ACROSS PORTIONS OF NORTHERN LOWER MICHIGAN
THIS AFTERNOON. SURFACE FRONT BECOMES SOMEWHAT MORE DIFFUSED AS
LIGHT PRESSURE GRADIENT ALLOWS LAKE BREEZE DEVELOPMENT...MOST
NOTABLE OFF LAKE HURON. GOOD EVIDENCE FOR TROUGHING AND LAKE BREEZES
TO FORCE GOOD INTERIOR SURFACE CONVERGENCE...PERHAPS FURTHER
AUGMENTED BY WEAK UPSLOPE FLOW INTO THE HIGHLANDS. MID LEVELS ALSO
LOOK TO HELP OUT...WITH WEAK WAVE SUPPLYING AT LEAST SOME UPWARD QG
SUPPORT ABOVE INCREASINGLY UNSTABLE LOW LEVELS. MID 50 DEWPOINTS
SHOULD SUPPORT SEVERAL HUNDRED JOULES OF ML CAPE...ONLY HELPING THE
CAUSE. INHERITED FORECAST ALREADY AGGRESSIVE WITH SHOWER AND STORM
DEVELOPMENT THIS AFTERNOON FOR AREAS SOUTH OF M-72. REALLY LIKE THIS
IDEA...AND WILL MAKE JUST SOME SMALL ADJUSTMENTS TO SUCH BASED
OFF LATEST GUIDANCE TRENDS. WIDESPREAD SEVERE WEATHER IS NOT
EXPECTED...ALTHOUGH WITH SUB 10 KFT FREEZING LEVELS...SUPPOSE AN
ISOLATED SEVERE HAILER IS POSSIBLE WITH THE STRONGEST UPDRAFTS (MUCH
LIKE YESTERDAY). SHOWER AND STORM THREAT EXPECTED TO END BY
AFTERNOON ACROSS EASTERN UPPER AS DEEP DRYING SPREADS SOUTH.

HIGH PRESSURE AND DEEP DRYING WILL CONTINUE TO SPREAD SOUTH...ENDING
ANY LINGERING SHOWER THREAT VERY QUICKLY THIS EVENING. CLEARING
SKIES AND LIGHT WINDS SHOULD LEAD TO A SEASONABLY CHILLY
NIGHT...WITH LOWS MOSTLY IN THE 40S.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 416 AM EDT MON JUN 17 2013

PLEASANT CONDITIONS ARE EXPECTED TO SETTLE IN FOR THE MID WEEK
PERIOD WITH HIGH PRESSURE IN CONTROL. WARMER AND PROGRESSIVELY MORE
HUMID CONDITIONS THEN MOVING IN LATE IN THE WEEK AND ESPECIALLY NEXT
WEEKEND AS UPPER LEVEL HEIGHTS INCREASE...ALONG WITH CHANCES FOR
SHOWERS AND THUNDERSTORMS. THE MAIN LONG TERM FORECAST CONCERNS ARE
MINIMAL TO START WITH POPS AND HOW WARM IT WILL ACTUALLY GET THE
MAIN CHALLENGES THEREAFTER.

TUESDAY INTO WEDNESDAY...HIGH PRESSURE DROPS SOUTHEAST OUT OF
CENTRAL CANADA INTO THE REGION. THIS IS EXPECTED TO ENSURE A DRY AND
LESS HUMID STRETCH OF WEATHER. HIGHS RANGING FROM THE UPPER 60S TO
MIDDLE 70S. LIGHT WINDS AND MAINLY CLEAR SKIES MONDAY NIGHT SETTING
THE STAGE FOR EXCELLENT RADIATIONAL COOLING CONDITIONS...YIELDING
LOWS IN THE UPPER 30S TO MIDDLE 40S (WITH EVEN AN OUTSIDE CHANCE OF
PATCHY FROST).

WEDNESDAY NIGHT THROUGH FRIDAY...THE REGION GETS ON THE MORE MOIST
SIDE OF THE SURFACE HIGH (RETURN FLOW). IN ADDITION...LOW PRESSURE
IN THE PLAINS WILL SEND A WEAK WARM FRONT TOWARD THE AREA. NOT
EXPECTING MUCH ACTION BUT WILL CONTINUE WITH SLIGHT CHANCE POPS FAR
NORTH THROUGH THURSDAY NIGHT WITH A SOMEWHAT BETTER CHANCE FOR
SHOWERS AND STORMS DURING THE DAY ON FRIDAY. HIGHS THURSDAY RANGING
FROM THE UPPER 60S NORTH TO THE MIDDLE AND UPPER 70S SOUTH. HIGHS
FRIDAY RANGING FROM THE LOWER 70S TO AROUND 80. LOWS IN THE MIDDLE
40S TO LOWER 50S WEDNESDAY NIGHT THEN THE LOWER TO MIDDLE 50S THURSDAY
NIGHT.

FRIDAY NIGHT THROUGH SUNDAY...IT LOOKS LIKE A FAIRLY ACTIVE PATTERN
SETTING UP ACROSS OUR NECK OF THE WOODS AS SHORTWAVES RIDE OVER THE
TOP OF THE RIDGE. THIS IN COMBINATION WITH A SURFACE WARM FRONT
DRAPED ACROSS THE REGION WILL BRING CHANCES FOR SHOWERS AND
THUNDERSTORMS. WARMER AND MORE HUMID WITH HIGHS OF WELL INTO THE 70S
TO THE LOWER 80S AND LOWS RANGING FROM THE UPPER 50S TO MIDDLE
60S. THERE IS THE POTENTIAL TO BE EVEN WARMER AS 850 MB
TEMPERATURES TOP OUT IN THE MIDDLE TEENS TO NEAR 20 C (GFS A
COUPLE OF DEGREES ABOVE THE ECMWF). HOWEVER...WILL CONTINUE TO
PLAY IT ON THE CONSERVATIVE SIDE DUE TO QUESTIONS OVER THE ACTUAL
COVERAGE OF SHOWERS/CLOUDS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 728 AM EDT MON JUN 17 2013

A COLD FRONT AND AN UPPER LEVEL DISTURBANCE WILL CONTINUE TO MOVE
ACROSS NORTHERN MICHIGAN TODAY. THIS WILL LEAD TO SCATTERED
SHOWERS AND POSSIBLY ISOLATED THUNDERSTORMS...MOST PREVALENT THIS
AFTERNOON. NO PREVAILING CIG RESTRICTIONS WILL BE CARRIED BUT COULD
SEE MVFR OR EVEN IFR CIGS IN ANY HEAVIER SHOWER. HIGH PRESSURE
BUILDS IN LATE TONIGHT LEADING TO MOSTLY CLEAR SKIES AND LIGHT AND
VARIABLE WINDS.


&&

.MARINE...
ISSUED AT 416 AM EDT MON JUN 17 2013

A WEAK COLD FRONT WILL SLOWLY DROP SOUTH ACROSS THE WATERS
TODAY...SHIFTING WINDS AROUND TO AN EASTERLY DIRECTION. LATE MORNING
AND AFTERNOON LAKE BREEZE DEVELOPMENT EXPECTED...FORCING LOCAL
ONSHORE FLOW. HIGH PRESSURE BUILDS SOUTH TONIGHT...MAINTAINING
CONTROL OF NORTHERN MICHIGAN WEATHER FOR THE NEXT FEW DAYS. THIS
WILL CONTINUE TO RESULT IN GENERALLY LIGHT WINDS...WITH NO HEADLINE
CRITERIA EXPECTED RIGHT THROUGH THE MIDDLE OF THIS WORK WEEK.
AFTERNOON THUNDERSTORMS POSSIBLE TODAY ACROSS PORTIONS OF THE
NEARSHORE WATERS...POSSIBLY RESULTING IN BRIEF GUSTY
WINDS.


&&

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

&&

$$

UPDATE...JPB
SYNOPSIS...AJS
SHORT TERM...MSB
LONG TERM...AJS
AVIATION...AJS
MARINE...MSB