Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 010811
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
411 AM EDT FRI AUG 1 2014

.SYNOPSIS...
ISSUED AT 402 AM EDT FRI AUG 1 2014

VERY PLEASANT WEATHER WITH SEASONABLE TEMPERATURES WILL BE THE RULE
FOR THE NEXT SEVERAL DAYS. ONLY SMALL AREAS OF NORTHERN MICHIGAN
WILL SEE THE POSSIBILITY OF AN ISOLATED LIGHT RAIN SHOWER.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 402 AM EDT FRI AUG 1 2014

...ANOTHER GREAT DAY...

IMPACTS: NONE.

CURRENT WEATHER AND SYNOPTIC PATTERN:

DEEP CLOSED UPPER AND SFC LOWS FINALLY LIFTING NE OF JAMES BAY EARLY
THIS MORNING...DRAGGING A VERY ILL-DEFINED (DUE TO VERY WEAK
PRESSURE GRADIENT) SFC TROUGH AXIS ACROSS NRN MICHIGAN. NO HELP
ALOFT VIA A SHORTWAVE EXCEPT CENTRAL LOWER ALONG A POOR EXCUSE FOR
AN INSTABILITY/MOISTURE GRADIENT. YET...THIS FEATURE HAS BEEN SEEN
THE LAST FEW NIGHTS WEST OF US...AND...SOME LIGHT RAIN SHOWER
ACTIVITY HAS BEEN ABLE TO SUSTAIN ITSELF. NO PRECIP AROUND HERE
HOWEVER...WITH A LACK OF AN UPPER LEVEL VORT MAX. SKIES WERE MOSTLY
CLEAR WITH THE EXCEPTION OF SOME DEEPER MOISTURE WRAPPED INTO NRN
CHIPPEWA COUNTY...ASSOCIATED WITH THE BACKSIDE OF THE UPPER LOW.
TEMPERATURES WERE A FEW DEGREES ABOVE LAST NIGHTS PACE...IN THE 50S
AND LOWER 60S. FURTHER UPSTREAM...NEARING THE US/CANADIAN
BORDER...WAS WHAT SHOULD BE THE LAST...FINALLY...SFC AND MID LEVEL
TROUGH.

SYNOPTIC PATTERN/WEATHER EVOLUTION:

ILL-DEFINED SFC TROUGH EXITS NE LOWER EARLY THIS MORNING WITH LITTLE
FANFARE/NO PRECIP. THE UPPER AND SFC LOWS CONTINUE TO LIFT NE
THROUGH THE DAY AND NIGHT...WHILE THE FINAL MID LEVEL TROUGH ROTATES
NEAR EASTERN UPPER LATE THIS AFTERNOON...AND ACROSS NRN LOWER
TONIGHT. THE ASSOCIATED SFC TROUGH AXIS GETS DISTURBED IN LAKE
BREEZE DEVELOPMENT...AND WEAK PRESSURE GRADIENT MAKES IT
UNRECOGNIZABLE TONIGHT. FORCING ALOFT AND WITH THE FRONT IS JUST
ABOUT NIL...VERY WEAK. NO MUCH CHANGES ALOFT...OUTSIDE OF MAYBE A
DEGREE COOLING IN THE 600-700MB LAYER...WHILE SLIGHTLY BETTER LOW
LEVEL WARMING ENSUES. SFC TEMPS ARE EXPECTED TO BE IN THE MIDDLE TO
UPPER 70S MOST AREAS TODAY. SO...WITH NO HELP ALOFT...WILL BE
LOOKING AT DIURNAL HEATING TO BE THE PRIMARY FACTOR FOR POSSIBLE
SHOWER DEVELOPMENT. OUTSIDE OF WARMER SFC TEMPS...THE WEAK BL
PRESSURE GRADIENT...SHOULD OFFER UP LITTLE TO NO MOISTURE ADVECTION.
THUS...AM EXPECTING A GOOD DEAL OF MIXING AGAIN. YESTERDAYS SFC DEW
POINTS DROPPED INTO THE UPPER 40S TO LOWER 50S MOST AREAS. MODEL
DATA SEEMINGLY WAY TOO HIGH WITH TRYING TO BRING IN MIDDLE TO UPPER
50S DEW POINTS THIS AFTERNOON...WHILE SOUNDING ANALYSIS SUGGESTS NO
MORE THAN LOWER 50S....POSSIBLE MORE UPPER 40S TOO. LAKE BREEZE
DEVELOPMENT WILL BE IN FULL FORCE TODAY...WITH INTERIOR SECTIONS
SEEING SOME MINOR LOW LEVEL CONVERGENCE. THE AFOREMENTIONED STEEPER
LAPSE RATE AND MOISTURE GRADIENT IS SUGGESTED TO LIFT INTO AREAS
ALONG AND SOUTH OF M-72 THIS AFTERNOON...WHICH WOULD BE FAVORABLE
FOR AIDING THE DEVELOPMENT FOR SHOWERS. WITH ONLY A DEGREE COOLING
ALOFT...THE EFFECT SHOULD BE MINOR. BUT THE COMBINATION OF WARMER
SFC TEMPS DOES LEAD TO A DEEPER MIXED LAYER (ALSO LIKELY LEADING TO
LOWER DEW POINTS). EVEN WITH THE HIGHER SFC DEW POINTS OF MODEL
WORLD...VERY LITTLE TO NO QPF SUGGESTED. TAKING THE MORE REAL DRIER
SFC TDS IN AROUND 50F-LOWER 50S...ONLY BRINGS A COUPLE HUNDRED J/KG
FOR MLCAPE...AND UP TO 400 J/KG FOR A SFC BASED PARCEL. SUPPOSE SOME
VERY ISOLATED SHOWERS ARE POSSIBLE IN INTERIOR SECTIONS OF EASTERN
UPPER AND NRN LOWER...WHICH SHOULD MOVE SLOWLY EAST IN WESTERLY
STEERING FLOW ALOFT. WILL LOWER POPS DOWN TO JUST 20% IN THESE
AREAS...BUT GUT FEELING IS THAT ANY COVERAGE SHOULD BE VERY VERY
MINIMAL.

THAT MID LEVEL TROUGH AXIS MAY HELP THINGS IN EASTERN UPPER...BUT
WITH LOSS OF HEATING...BY THE TIME IT CROSSES INTO NRN LOWER...IT
SHOULDN`T BE ABLE TO SUSTAIN ANY ACTIVITY. THUS...AM EXPECTING
THINGS TO END AT NIGHTFALL. SOME CLOUDINESS IS ANTICIPATED THOUGH.
PRETTY QUIET NIGHT WITH LOWS IN THE 50S.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 402 AM EDT FRI AUG 1 2014

SEEMS LIKE AN UNENDING POSITIVE PACIFIC/NORTH AMERICAN PATTERN. A
CLOSED MID-LEVEL LOW PRESSURE SYSTEM NEAR JAMES BAY CONTINUES TO
GENERATE PERIODIC SHOWERS AND CLOUD COVER ACROSS NORTHERN MICHIGAN.
THERE ARE SUBTLE HINTS OF THIS PATTERN FINALLY BEGINNING TO BECOME
MORE FLAT..BUT NOT UNTIL THE END OF THE NEXT WORK WEEK. THIS WEEKEND
APPEARS TO HAVE THE BEST CHANCES OF WARMING TO ABOVE NORMAL AS H8
TEMPS WARM TO ABOVE 12C. TIMING OF SHORTWAVES AND ASSOCIATED
VORTICITY EMBEDDED IN THE BROAD TROUGHING PATTERN ARE NEAR
IMPOSSIBLE TO TIME...SO WILL CONTINUE WITH CHANCE POPS...ESPECIALLY
DURING THE DAYTIME HOURS WITH DIURNAL HEATING TO AID IN THE
DEVELOPMENT OF ANY PRECIPITATION. WINDS APPEAR TO REMAIN
RELATIVELY LIGHT THROUGHOUT THE NEXT WEEK.

SATURDAY AND SUNDAY...SHOULD BE ANOTHER DECENT NORTHERN MICHIGAN
WEEKEND EVEN WITH THE CONTINUED AFOREMENTIONED BROAD TROUGH OVER THE
GREAT LAKES REGION. THIS TROUGH WILL CONTINUE TO PRODUCE CHANCES OF
PRECIPITATION...MAINLY OVER NORTHEAST LOWER NEAR SAGINAW BAY ON
SATURDAY. ALTHOUGH ANY PRECIPITATION THAT DOES DEVELOP WILL NOT BY
ANY MEANS BE A WASHOUT. TRENDS ARE EVEN BEGINNING TO SHOW A
MID-LEVEL CAP THAT MAY INHIBIT PRECIPITATION ALTOGETHER FOR THE
WEEKEND. MODIFIED SOUNDINGS SHOW NEARLY 100 JOULES OF MLCINH FOR
SATURDAY. TEMPERATURES WILL REACH INTO THE UPPER 70S TO NEAR 80
THROUGHOUT THE WEEKEND. LOW TEMPERATURES WILL ONLY DROP TO THE LOW
50S.

MONDAY...A POSSIBLE COLD FRONTAL PASSAGE FROM AN ASSOCIATED SURFACE
LOW PRESSURE SYSTEM OVER JAMES BAY ALONG WITH YET ANOTHER SHORTWAVE
RIDING THE LONG WAVE TROUGH MAY FIRE OFF SOME SHOWERS AND POSSIBLY
EVEN SOME THUNDER DURING THE AFTERNOON HOURS OVER NORTHERN MICHIGAN.
TEMPERATURES WILL BE SLIGHTLY COOLER THAN THE WEEKEND...BUT STILL IN
THE LOW TO MID 70S WITH LOW TEMPERATURES IN THE MORNING HOURS ONLY
DROPPING TO AROUND 60.

TUESDAY THROUGH FRIDAY...AS MENTIONED ABOVE...SOME SUBTLE HINTS OF
THE POSITIVE PNA PATTERN FINALLY BREAKING DOWN...WITH WHAT HAS BEEN
A SEMI-PERMANENT TROUGH OVER THE GREAT LAKES BEGINNING TO MOVE EAST
AND A RIDGE BUILDING OVER NORTHERN MICHIGAN. WITH THIS COMES HEIGHT
INCREASES AND A FRONTAL BOUNDARY PUSHING NORTH...POSSIBLY INTO THE
GREAT LAKES REGION. STILL FAIRLY LOW CONFIDENCE WITH EXACT TIMING
AND LOCATION DUE TO BEING SO FAR OUT AND MODEL GUIDANCE CONTINUING
TO CHANGE WITH EACH RUN. DAYTIME TEMPERATURES APPEAR TO REMAIN IN
THE 70S THROUGHOUT THE PERIOD WITH LOWS IN THE MID 50S TO LOW 60S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1151 PM EDT THU JUL 31 2014

GROUND FOG OVERNIGHT PLN/MBL. OTHERWISE VFR.

WEAK LOW PRESSURE JUST SOUTH OF JAMES BAY WILL MOVE NE AWAY FROM
THE REGION. THAT WILL LEAVE BROAD...WEAK HIGH PRESSURE IN CONTROL.
SOME FOG IS EXPECTED AGAIN TONIGHT AT FOG-PRONE MBL/PLN. BRIEF
INCURSIONS OF IFR ARE POSSIBLE...BUT FOR NOW WILL JUST TEMPO IN
SEVERAL HOURS OF MVFR VERY LATE TONIGHT.

LIGHT WINDS TONIGHT...LAKE BREEZES BY FRIDAY AFTERNOON.

&&

.MARINE...
ISSUED AT 402 AM EDT FRI AUG 1 2014

NO MARINE ISSUES TO BE CONCERNED WITH FOR SEVERAL DAYS...WELL INTO
NEXT WORK WEEK...WITH A LIGHT PRESSURE GRADIENT...AND AFTERNOON LAKE
BREEZES. MAYBE AN ISOLATED SHOWER ACROSS NE LOWER EACH AFTERNOON BUT
THREAT FOR THIS IS MINIMAL AT BEST.

&&

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

&&

$$

SYNOPSIS...SMD
SHORT TERM...SMD
LONG TERM...TL
AVIATION...JZ
MARINE...SMD





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