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000
FXUS63 KAPX 161816
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
216 PM EDT SUN JUN 16 2013

.SYNOPSIS...
ISSUED AT 332 AM EDT SUN JUN 16 2013

A WEAK SYSTEM DROPPING INTO THE GREAT LAKES TODAY...WILL SLOWLY EXIT
NORTHEAST INTO QUEBEC MONDAY. THIS PATTERN WILL GENERATE MUGGY
CONDITIONS ALONG WITH A FEW THUNDERSTORMS...ACROSS NORTHERN MICHIGAN
THROUGH MONDAY.

HOWEVER...A LARGE AREA OF HIGH PRESSURE WILL MOVE INTO THE GREAT
LAKES AND UPPER MIDWEST MONDAY NIGHT...AND WILL REMAIN NEARLY
STATIONARY OVER THE REGION INTO THURSDAY. THIS PATTERN WILL
GENERATE SOME SUN ALONG WITH NEARLY SEASONAL TEMPERATURES...OVER THE
GREAT LAKES THROUGH MIDWEEK.

&&

.UPDATE...
ISSUED AT 215 PM EDT SUN JUN 16 2013

LINE OF CONVECTION HAS DEVELOPED OVER CHIPPEWA COUNTY WITH SOME
SMALL HAIL AROUND KINCHELOE AND A WIND GUST TO 34 MPH AT CIU.
NASCENT CONVECTION ALSO DEVELOPING ALONG A LINE FROM NORTH OF
BEAVER ISLAND BACK TOWARD MQT...ALSO WATCHING A CONVERGENCE OF CU
OVER SOUTHEAST PORTION OF THE FORECAST AREA WHERE MLCAPE ABOVE
1000J/KG AND CINH IS SHRINKING (AND LAKE BREEZE HAS KICKED IN AS
OSC).

UPDATE ISSUED AT 1151 AM EDT SUN JUN 16 2013

14Z SURFACE/COMPOSITE ANALYSIS SHOWS A 1004 SURFACE LOW OVER
NORTHEAST ONTARIO...WITH A TRAILING COLD FRONT BACK ACROSS SOUTHWEST
ONTARIO AND FAR SOUTHERN LOWER MICHIGAN.  A SECOND BOUNDARY RUNS
NORTHWEST-SOUTHEAST ACROSS NORTHERN ONTARIO/SOUTHERN QUEBEC.  WATER
VAPOR IMAGERY SHOWS A VORTICITY CENTER PASSING THE NORTH SHORE OF
LAKE SUPERIOR...WITH SCATTERED SHOWERS ASSOCIATED WITH IT.  THIS
WAVE RUNS ALONG THE EDGE OF AN EAST-WEST ORIENTED LATENT PV ANOMALY
THAT CROSSES THE LENGTH OF THE UPPER PENINSULA AND BACK INTO
NORTHERN MINNESOTA.  ALSO WITHIN THIS ANOMALY APPEARS TO BE ANOTHER
VORTICITY CENTER NOT AS OBVIOUS (SINCE IT IS STILL WITHIN FAIRLY DRY
AIR) MOVING INTO NORTHWEST WISCONSIN.  TO THE SOUTH OF THIS...
SUBSIDENCE/DRYING HAS PUSHED ACROSS NORTHERN/CENTRAL LOWER
MICHIGAN.  12Z APX/GRB/MPX SOUNDINGS SHOW PROGRESSIVE DRYING
UPSTREAM...BUT AXIS OF BETTER MOISTURE EXISTS TO THE NORTH OF THE
ABOVE MENTIONED PV ANOMALY ALONG WITH COOLER MID LEVEL
TEMPERATURES.  CLOUDS REMAIN OVER MUCH OF THE FORECAST AREA THOUGH
CLEARING IS SPREADING INTO EASTERN UPPER WITH BREAKS IN THE CLOUDS
CLOSER TO SAGINAW BAY.

ISSUES FOR THE AFTERNOON WILL REVOLVE AROUND CLOUD COVER AND
INSTABILITY ISSUES.  AS MENTIONED IN PREVIOUS UPDATE CLOUD COVER IS
FAIRLY THIN AND WILL CONTINUE TO MIX WITH TIME THOUGH WILL INITIALLY
BE REPLACED WITH SC.  MODIFYING THE 12Z APX SOUNDING FOR 78/61
YIELDS NEARLY 1000J/KG MLCAPE...BUT 2 CAVEATS HERE.  FIRST IS A
DECENT INVERSION IN THE 900-850MB LAYER THAT WILL NEED TO BE MIXED
THROUGH...AND SECOND IS DRIER AIR ADVECTING IN FROM WISCONSIN THAT
WILL MIX INTO THE BOUNDARY LAYER LATER THIS AFTERNOON (THOUGH MAY BE
OFFSET TO SOME DEGREE BY EVAPORATION OF OVERNIGHT RAINFALL).  THE
LATTER ISSUE WILL PROBABLY TAKE SOME TIME TO OCCUR OVER NORTHEAST
LOWER...SO THERE MAY BE A WINDOW OF OPPORTUNITY THIS AFTERNOON
(PROVIDED DEW POINTS REMAIN THE UPPER 50S/LOWER 60S) THAT SOME
CONVECTION MAY POP ALONG/EAST OF THE M-33 CORRIDOR.  THIS PROCESS
COULD BE AIDED BY LAKE BREEZE CONVERGENCE.  ANOTHER CONCERN AREA IS
EASTERN UPPER WHERE IT IS ALREADY COOLER IN THE MID LEVELS AND
SOUTHWEST WINDS OFF LAKE MICHIGAN MAY FOCUS CONVERGENCE AND ALLOW
FOR CONVECTIVE DEVELOPMENT HERE AS WELL.  OTHER ISSUE IS SHORT WAVE
TROUGH MOVING ACROSS WISCONSIN...WHICH IS FORECAST TO ARRIVE OVER
NORTHERN LOWER IN THE 22Z-00Z TIME FRAME.  AS THIS FEATURE CROSSES
NORTHERN WISCONSIN THIS AFTERNOON IT MAY RESULT IN CONVECTIVE
DEVELOPMENT THAT PUSHES INTO NORTHWEST LOWER TOWARD EVENING.
CURRENT FORECAST DOES ACCOMMODATE THESE LATTER TWO SCENARIOS TO SOME
DEGREE...WILL ADD IN SOME SHOWER POTENTIAL FOR NORTHEAST LOWER AS
WELL.

UPDATE ISSUED AT 1007 AM EDT SUN JUN 16 2013

12Z MESOANALYSIS SHOWS A WAVE OF LOW PRESSURE OVER GEORGIAN BAY...
SOME SEMBLANCE OF A WEAK BOUNDARY EXTENDS BACK TO THE SOUTHWEST
ACROSS SOUTHERN LOWER MICHIGAN. ANOTHER BOUNDARY/THETA-E GRADIENT
LIES ACROSS NORTHEAST ONTARIO. PLENTY OF LOW CLOUDS ACROSS THE
FORECAST AREA WITH FOG OVER EASTERN UPPER/NORTHWEST LOWER.
PRECIPITATION HAS MOVED EAST OF LAKE HURON AS DRY/SUBSIDENCE
SPREADS INTO NORTHERN MICHIGAN PER WATER VAPOR IMAGERY. SOME
DRIZZLE ACROSS EASTERN UPPER/NORTHWEST LOWER WITHIN THE LOW CLOUD
DECK. 12Z APX SOUNDING SHOWS A VERY SHALLOW SURFACE BASED
SATURATED LAYER...BEGINS TO DRY OUT ABOVE 925MB (PIREP OUT OF TVC
REPORTING CLOUD TOPS AT 2500FT AND CLEAR ABOVE).

EARLY FORECAST CHANGES FOCUS MAINLY ON FOG/DRIZZLE COVERAGE AND
ADJUSTMENTS TO CLOUD COVER (WILL LIKELY BE MORE PERSISTENT THROUGH
THE MORNING CLOSER TO LAKE MICHIGAN WHERE MARINE LAYER IS INVOLVED).

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 332 AM EDT SUN JUN 16 2013

BULLSEYE OF UPPER LEVEL DIVERGENCE...DEEP MOISTURE ADVECTION...AND
CONVECTIVELY INFLUENCED MID LEVEL WAVES HELPING DRIVE A RATHER
HEALTHY AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS ACROSS THE AREA
AT THIS EARLY HOUR. MOST OF THE ACTIVITY REMAINS CENTERED SOUTH OF
THE STRAITS...WITH SOME AREAS RECEIVING OVER A HALF INCH OF MUCH
NEEDED RAINFALL. OVERHEAD PROGRESSIVE FLOW SOUTH OF SOUTH CANADA MID
LEVEL LOW KEEPING THINGS ON THE MOVE...WITH WATER VAPOR IMAGERY
CONFIRMING RAPID OFF THE DECK DRYING ALREADY PUSHING INTO LAKE
MICHIGAN. LOW LEVEL DRYING MUCH SLOWER TO ARRIVE...WITH LOW CLOUDS
AND FOG RAPIDLY DEVELOPING ACROSS PARTS OF WISCONSIN (NO DOUBT
HELPED ALONG BY HEAVY EARLY EVENING RAINS). EXPECT ABOVE TRENDS TO
CONTINUE THROUGH THE REMAINDER OF THE EARLY MORNING HOURS...WITH
CORRIDOR OF RAINS STEADILY ENDING FROM WEST TO EAST...ONLY TO BE
REPLACED WITH AREAS OF FOG AND LOW CLOUDS. FORECAST CONCERNS CENTER
ON ENDING OF INITIAL RAIN THREAT THIS MORNING...FOLLOWED BY
ADDITIONAL SHOWER AND THUNDERSTORM POTENTIAL THIS AFTERNOON THROUGH
THE OVERNIGHT AS MORE ENERGY DROPS ACROSS THE NORTH WOODS.

OVERNIGHT RAINS SHOULD BE OFF TO OUR EAST BY SUNRISE TODAY...WITH
UPSTREAM MID LEVEL DRY AIR OVERSPREADING OUR AREA BEHIND PASSING
SURFACE TROUGH AXIS. MORNING EXPECTED TO REMAIN DRY...WITH LOW
CLOUDS/FOG STEADILY MIXING OUT AS LOW LEVEL DRYING ENSUES. FOCUS FOR
THE AFTERNOON CENTERS ON DIURNALLY DRIVEN SHOWER AND STORM
POTENTIAL...ESPECIALLY WITHIN DUAL SURFACE WIND CONVERGENCE AXES
OVER NORTHEAST LOWER AND EASTERN UPPER MICHIGAN. UPSTREAM DEWPOINT
ANALYSIS AND BACKWARD RUN LOW LEVEL TRAJECTORIES BOTH SUGGEST TOO
HIGH OF GUIDANCE PROGGED AFTERNOON DEWPOINTS ACROSS NORTHEAST LOWER.
SURFACE CONVERGENCE NOT OVERLY STELLAR EITHER...AND WHEN COUPLED
WITH COMPLETE LACK OF BACKGROUND SYNOPTIC DYNAMICS...JUST CAN FIND
NO COMPELLING REASON FOR ADDITIONAL SHOWER DEVELOPMENT ACROSS
NORTHEAST LOWER. MUCH TOUGHER CALL NORTH OF THE BIG BRIDGE...WITH
LAKE DRIVEN INTERIOR CONVERGENCE AXIS SETTING UP EARLY THIS
AFTERNOON ACROSS INTERIOR EASTERN UPPER. BACKGROUND WEST WINDS SHOULD
FAVOR THIS CONVERGENCE DROPPING SOUTH WITH TIME...PERHAPS PUSHING
INTO FAR NORTHWEST LOWER BY LATER THIS AFTERNOON. LOW LEVEL MOISTURE
AND DEEP FORCING NOTHING TO RIGHT HOME ABOUT...BUT SIMILAR
CONDITIONS YESTERDAY BACK ACROSS SOUTHERN CANADA DID MANAGE TO SPARK
SOME SCATTERED SHOWERS AND STORMS. TRAJECTORY ANALYSIS SUGGESTS THIS
UPSTREAM AIRMASS SPREADING INTO EASTERN UPPER AS SURFACE CONVERGENCE
IS MAXIMIZED. BASED ON UPSTREAM COVERAGE AND LESS THAN IDEAL SURFACE
MOISTURE PROGS...WITH KEEP JUST LOW END SHOWER AND STORM
POTENTIAL...SLOWLY SLIDING THIS CORRIDOR SOUTH WITH CONVERGENCE
ZONE. NO SEVERE WEATHER IS EXPECTED...BUT MARGINALLY DRY LOW LEVELS
DOES SUPPORT SOME BRIEFLY GUSTY WINDS WITH ANY OF THE MORE ORGANIZED
ACTIVITY. A RATHER MILD DAY BY RECENT STANDARDS...WITH HIGHS WELL
INTO THE 70S AND LOWER 80S SOUTH OF THE STRAITS. OF COURSE...
READINGS WILL BE A TOUCH COOLER NEAR THE BIG WATERS AND ACROSS
EASTERN UPPER.

A RATHER LOW CONFIDENCE FORECAST HEADING THROUGH TONIGHT. SECONDARY
SHORTWAVE TROUGH AND ATTENDANT SURFACE REFLECTION PUSH THROUGH THE
REGION. FORCING...HOWEVER...IS NOT OVERLY IMPRESSIVE...AND FEATURES
ARE COMING THROUGH WHEN ALL DIURNALLY ENHANCED INSTABILITY IS LOST.
SURFACE/MID LEVEL CONVERGENCE AXIS MAY BE ABLE TO KICK A FEW SHOWERS
AND ISOLATED THUNDERSTORMS...AND WILL SIMPLY FOLLOW THESE FEATURES
SOUTH FOR LOW END POP PLACEMENT. LOW TONIGHT GENERALLY IN THE 50S.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 332 AM EDT SUN JUN 16 2013

MONDAY...THE WEAK SYSTEM THAT DROPPED INTO THE STATE SATURDAY NIGHT
AND SUNDAY WILL SLOWLY EXIT NORTHEAST INTO QUEBEC MONDAY...WHILE
BROAD UPPER TROUGHING LINGERS ACROSS THE GREAT LAKES AND UPPER MIDWEST.
MODELS ARE SUGGESTING COOLER TEMPERATURES OVER NORTHERN MICHIGAN
MONDAY...AS 850MB TEMPS DROP FROM 12C SUNDAY TO BTWN 6C-8C MONDAY ON
THE BACKSIDE OF THE EXITING WEEKEND SYSTEM. DRIER AIR ALSO PROGGED
TO SINK SOUTH INTO THE GREAT LAKES THROUGHOUT THE DAY MONDAY...AS
850MB DEW PTS DROP FROM 12C SUNDAY TO UNDER 4C BY MONDAY EVENING
WHILE SFC DEW PTS DROP FROM THE UPPER 50S SUNDAY INTO THE LOWER 40S
BY MONDAY EVENING. OVERALL FORECAST TREND FOR MONDAY WILL BE COOLER
WITH ANY LINGERING CONVECTION ENDING OVER ERN UPPER IN THE MORNING
...BEFORE DIMINISHING IN THE AFTERNOON SOUTH OF THE STRAITS. SOME
CONVECTION MAY LINGER INTO THE EARLY EVENING OVER THE SE CWA...AS
850MB MSTR REMAINS HIGH WHILE 850/500MB QVECTORS SHOW SOME
CONVERGENCE LINGERING NEAR SAGINAW BAY IN ADVANCE OF AN APPROACHING
500MB TROUGH. OTHERWISE...WILL MENTION TEMPERATURES DROPPING INTO
THE 40S MONDAY NIGHT...AS SKIES CLEAR AND WINDS CALM IN RESPONSE TO
HIGH PRESSURE SETTLING INTO THE REGION.

TUESDAY AND WEDNESDAY...LARGE AREA OF HIGH PRESSURE WHICH BECAME
CENTERED OVER THE GREAT LAKES AND UPPER MIDWEST MONDAY...WILL REMAIN
NEARLY STATIONARY OVER THE REGION THROUGH MIDWEEK. AT UPPER LEVELS
THE BROAD UPPER TROUGH EARLY WILL TREND MORE ZONAL THROUGH THE
PERIOD...ALLOWING 850MB TEMPS TO WARM FROM 8C TUESDAY TO NEARLY 12C
BY THURSDAY. MODEL SOUNDINGS AND MSTR PROGS SHOWING A RATHER DRY
AIRMASS TO LINGER OVER THE GREAT LAKES THROUGH WEDNESDAY EVENING...
WITH 850MB DEW PTS BETWEEN 0C AND -4C WHILE SFC DEW PTS REMAIN IN
THE 40S. OVERALL WILL CONTINUE GENERALLY A DRY TREND INTO MIDWEEK
WITH AFTN HIGH TEMPS NEARLY SEASONAL IN THE LOW TO MID 70S. THERE IS
A SMALL CHC OF CONVECTION NORTH OF THE STRAITS EARLY THURSDAY
MORNING...AS WEAK FORCING FROM A 500MB TROUGH COMBINES WITH WEAK SFC
BOUNDARY AND INCREASING MID LEVEL DEW PTS...THOUGH WILL KEEP CHCS
TO A MINIMUM AT THE MOMENT.

THURSDAY THROUGH SATURDAY...MUCH WARMER AND MORE HUMID THROUGH THE
PERIOD WITH SOME CONVECTION POSSIBLE TO ROUND OUT THE WORK WEEK AND
THE START OF THE UPCOMING WEEKEND. OVERALL CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL BE MINIMAL INTO SATURDAY...AS A WEAK SFC BOUNDARY
SLOWLY DRAPES SOUTH OVR NRN MI BY FRIDAY WHILE UPPER CYCLONIC FLOW
THURSDAY TRANSITIONS TO WEAK UPPER RIDGING BY SATURDAY. SUMMER
LIKE WARMTH AND HUMIDITY IS EXPECTED OVER THE STATE FRIDAY AND
SATURDAY...AS 850MB TEMPS WARM TO BETWEEN 12C AND 14C WHILE MILD LVL
DEW PTS INCREASE TO 12C AND SFC DEW PTS INCREASE INTO THE UPPER
50S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 200 PM EDT SUN JUN 16 2013

VFR CONDITIONS EXPECTED THROUGH TONIGHT OUTSIDE OF A BRIEF PERIOD
OF MVFR/HIGH END IFR CEILINGS AT PLN THROUGH ABOUT 20Z. ADDITIONAL
SHOWERS POSSIBLE TONIGHT INTO MONDAY MORNING.

&&

.MARINE...
ISSUED AT 332 AM EDT SUN JUN 16 2013

FOG AND HAZE THE PRIMARY CONCERN HEADING THROUGH TODAY
AS LOW LEVEL MOISTURE RICH AIR OVERSPREADS THE STILL COOL LAKE
WATERS. SOME OF THIS MAY CONTINUE INTO TONIGHT AS A SECONDARY TROUGH
AXIS SLOWLY SLIPS SOUTH INTO THE AREA. OTHERWISE...RELATIVELY LIGHT
PRESSURE GRADIENT TO REMAIN FOR THE NEXT SEVERAL DAYS...KEEPING WIND
SPEEDS BELOW HEADLINE CRITERIA. LAKES WILL CONTINUE TO HAVE SOME
INFLUENCE ON LOCAL WIND DIRECTIONS. EARLY MORNING SHOWERS WILL COME
TO AND END...WITH ADDITIONAL SHOWER AND THUNDERSTORM CHANCES
RETURNING FOR PARTS OF THE NEARSHORE WATERS THIS AFTERNOON THROUGH
MONDAY.


&&

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

&&

$$

UPDATE...JPB
SYNOPSIS...SWR
SHORT TERM...MSB
LONG TERM...SWR
MARINE...MSB