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000
FXUS63 KAPX 101027
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
627 AM EDT THU JUL 10 2014

.SYNOPSIS...
ISSUED AT 329 AM EDT THU JUL 10 2014

HIGH PRESSURE WILL BRING SUNSHINE TO THE REGION TODAY AND
FRIDAY...THOUGH TEMPERATURES WILL AVERAGE A BIT BELOW NORMAL. CLOUDS
WILL INCREASE LATE FRIDAY AS A WEAK DISTURBANCE APPROACHES...AND
THERE IS A RISK FOR SHOWERS BEGINNING FRIDAY NIGHT CONTINUING INTO
THE WEEKEND.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 329 AM EDT THU JUL 10 2014

OVERVIEW: MID LEVEL TROUGHINESS IN THE PROCESS OF RETREATING
NORTHEAST THROUGH CANADA REPLACED BY LOW AMPLITUDE RIDGING NOSING
INTO THE GREAT LAKES. EXPANSIVE SFC HIGH PRESSURE HAS DEVELOPED
ACROSS THE GREAT LAKES AND MUCH OF THE EASTERN CONUS FOR THAT
MATTER...RESULTING IN QUIET WEATHER FROM THE NRN PLAINS THROUGH THE
GREAT LAKES. BUT NOT A TREMENDOUS PUSH OF DRY AIR INTO THE GREAT
LAKES OVER THE LAST 24 HOURS (0.75 PWAT ON 00Z APX SOUNDING) WITH
DEWPOINTS HOLDING IN THE 50S YESTERDAY (WEDNESDAY) AFTERNOON. THIS
HAS LEAD TO SOME FOG DEVELOPMENT OVERNIGHT AND KEPT TEMPERATURES
JUST A LITTLE WARMER (SPANNING THE 40S). IN ADDITION...STILL SOME
SCT CLOUDS OUT THERE PARTICULARLY ACROSS EASTERN UPPER MICHIGAN
AND SKIRTING THE LAKE HURON SHORELINE.

TODAY...HIGH PRESSURE SETTLES OVER THE GREAT LAKES IN EARNEST.
DEEPER MIXING/MORE SUN AND WARMER TEMPS WILL HELP TO MIX/DRY OUT THE
LOW LEVELS BETTER TODAY KNOCKING DEWPOINTS DOWN INTO THE LOWER 40S.
BUT...WITH A DEEPER MIXED LAYER PUSHING 7K FEET MSL...WILL PROBABLY
SEE SCT HIGH BASE CU DEVELOPMENT THIS AFTERNOON PARTICULARLY OVER
THE HIGHER TERRAIN OF NE LOWER MICHIGAN AS INLAND THERMAL LOW AND
LAKE BREEZES DEVELOP AND CONTRACT INLAND. BUT OVERALL...A DECENT DAY
WITH TEMPS WARMING BACK INTO THE 70S.

TONIGHT...MINIMAL WEATHER CONCERNS PERSIST AS HIGH PRESSURE DRIFTS
ACROSS THE GREAT LAKES. A BIT COOLER WITH A DRIER BOUNDARY
LAYER/LOWER SFC DEWPOINTS...MOSTLY SPANNING TH 40S. SOUTHERLY RETURN
FLOW WILL BEGIN TO SPREAD CLOUD COVER BACK INTO THE UPPER
MIDWEST/WESTERN GREAT LAKES VERY LATE...BUT MAINLY CLEAR SKIES AND
LIGHT WINDS WILL PREVAIL THROUGH MOST OF THE NIGHT.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 329 AM EDT THU JUL 10 2014

HIGH IMPACT WEATHER POTENTIAL: MINIMAL...THOUGH THUNDERSTORM CHANCES
INCREASE BY LATE IN THE WEEKEND.

FRIDAY AND FRIDAY NIGHT...HIGH PRESSURE OVER THE ERN GREAT LAKES
FRIDAY WILL PERMIT S/SW RETURN FLOW TO ADVECT SLIGHTLY HIGHER
MOISTURE INTO THE REGION /WITH H8 DWPTS NEARING +10C/. LLJ ANCHORED
OVER WRN GREAT LAKES EARLY FRIDAY WILL LIKELY BE SUPPORTING
CONVECTION UPSTREAM OVER WI FRIDAY MORNING. HOWEVER...WEAK FLOW
ALOFT IS EXPECTED TO PRECLUDE SHOWERS FROM REACHING FORECAST AREA
FRIDAY AFTERNOON...THROUGH SOME INCREASE IN CLOUDS IS LIKELY. HIGHS
WILL PEAK IN THE 70S TO NEAR 80. WEAK SHORT WAVE ALOFT...AN
APPROACHING SURFACE TROUGH...MODEST WAA...AND H8 MOISTURE AXIS
SHIFTING E WILL SUPPORT SCATTERED SHOWERS FRIDAY NIGHT...INITIALLY
OVER NW LOWER IN THE EVENING...THEN OVER ALL AREAS AFTER MIDNIGHT
/INCLUDING ERN UPPER AND NE LOWER/. WITH ONLY MARGINAL FORCING AND
INSTABILITY...TENTATIVELY REMOVED ALL THUNDER REFERENCES FROM
FORECAST FOR FRIDAY NIGHT. LOWS FRIDAY NIGHT WILL FALL BACK INTO THE
50S TO NEAR 60.

SATURDAY AND SATURDAY NIGHT...LATEST NUMERICAL GUIDANCE POINTS TO A
PRETTY NEBULOUS WEATHER REGIME SATURDAY...WITH AN ALREADY WEAK
SURFACE TROUGH MOVING INTO THE REGION /AND WEAKENING FURTHER/
RESULTING IN AN ILL-DEFINED PRESSURE PATTERN BY MIDDAY. STILL...H8
MOISTURE AXIS /WITH DWPTS APPROACHING +14C/ WILL BE DIRECTED INTO
LOWER MICHIGAN. THIS ELEVATED LOW LEVEL MOISTURE...TOGETHER WITH AT
LEAST SOME CONVERGENCE FROM PROBABLE LAKE BREEZES MAY SUPPORT SPOTTY
SHOWERS AND A FEW AFTERNOON STORMS /THOUGH PRECIP WILL LIKELY BE
EXCEPTION RATHER THAN RULE/. A FAIR AMOUNT OF UNCERTAINTY IN HOW DAY
WILL EVOLVE...WITH MODEL SOUNDINGS SHOWING GOOD DEAL OF LOWER
CLOUDINESS /ESPECIALLY EARLY SATURDAY/ WHICH MAY INHIBIT WARMING AND
SUBSEQUENTLY DESTABILIZATION. THAT SAID...SMALL RISK FOR CONVECTION
WILL CONTINUE INTO SATURDAY NIGHT...AS HEIGHT FALLS BEGIN ACROSS THE
NRN GREAT LAKES...A SURFACE TROUGH APPROACHES FROM THE WEST...AND
500 MB WINDS APPROACH 50 KT ACROSS THE NRN GREAT LAKES BY LATE
SATURDAY NIGHT. HIGHS SATURDAY WILL GENERALLY BE IN THE 70S...WITH
LOWS SATURDAY NIGHT FROM AROUND 60 TO THE MID 60S.

REMAINDER OF FORECAST /SUNDAY THROUGH WEDNESDAY/...A RELATIVELY
ANOMALOUS MID JULY UPPER FLOW PATTERN IS SET TO EVOLVE BY EARLY NEXT
WEEK...AND MEDIUM RANGE GUIDANCE IS IN AMAZINGLY GOOD AGREEMENT
REGARDING THIS EVOLUTION. GFS/ECMWF BOTH SHOW STEADY HEIGHT FALLS
OVER THE GREAT LAKES EARLY IN THE PERIOD...AS AN IMPRESSIVE CLOSED
UPPER LOW OVER FAR WRN ONTARIO SUNDAY DROPS ABRUPTLY SOUTHWARD INTO
THE WRN GREAT LAKES MONDAY...CROSSES MICHIGAN TUESDAY...BEFORE
LOOSENING ITS GRIP ON THE REGION SOMEWHAT BY WEDNESDAY. WHILE THE
GFS ENSEMBLE MEAN PLACES CLOSED UPPER LOW FARTHER NORTH...THE
OPERATIONAL GFS/ECMWF RUNS EACH SHOW A /SUB 552 DM/ CLOSED 500 MB
LOW VICINITY OF NRN LAKE HURON TUESDAY /VERY UNUSUAL FOR MID JULY/.

WHAT DOES THIS MEAN FOR NORTHERN MICHIGAN? HEIGHT FALLS ASSOCIATED
WITH SHORT WAVE ENERGY ROTATING AROUND UPPER LOW WILL SUPPORT
SCATTERED SHOWERS/THUNDERSTORMS SUNDAY AND MONDAY. RISK FOR SHOWERS
WILL PERSIST INTO TUESDAY WITH UPPER LOW FORECAST TO BE IN CLOSE
PROXIMITY. SOME IMPROVEMENT WILL BE POSSIBLE WEDNESDAY ASSUMING
UPPER LOW BEGINS TO EJECT AS FORECAST. TEMPERATURES WILL BE BELOW
NORMAL THROUGH THE PERIOD...WITH HIGHS GENERALLY IN THE 70S
SUNDAY...DROPPING TO THE UPPER 50S TO MID 60S BY TUESDAY...BEFORE
THEY SLOWLY REBOUND.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 625 AM EDT THU JUL 10 2014

SPOTTY FOG ACROSS NRN LOWER MICHIGAN THIS MORNING...IMPACTING JUST
MBL ALTHOUGH SOME BRIEF VSBY REDUCTIONS REMAIN POSSIBLE AT PLN/TVC
THROUGH 13Z OR SO. OTHERWISE...SOLID VFR CONDITIONS AT THE
TERMINAL SITES TODAY AND TONIGHT. LIGHT WINDS WILL ALLOW LAKE
BREEZES TO DEVELOP AND DOMINATE WIND DIRECTIONS AT ALL SITES.

&&

.MARINE...
ISSUED AT 329 AM EDT THU JUL 10 2014

LIGHT WINDS TODAY AND TONIGHT WITH LAKE BREEZES FULLY DEVELOPING
ALONG ALL COASTLINES BY THIS AFTERNOON. STRONGER SW FLOW DEVELOPS
FRIDAY AND FRIDAY NIGHT ALTHOUGH WINDS/WAVES SHOULD REMAIN BELOW
SMALL CRAFT CRITERIA.


&&

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

&&

$$

SYNOPSIS...BS
SHORT TERM...ADAM
LONG TERM...BS
AVIATION...ADAM
MARINE...ADAM