Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 121118
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
718 AM EDT SAT JUL 12 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT SAT JUL 12 2014

WEST FLOW ALOFT PERSISTS THIS MORNING ON SOUTHERN EDGE OF UPPER LOW
OVER NORTHERN SASKATCHEWAN AND MANITOBA. INITIAL SFC COLD FRONT IS
PUSHING ACROSS WESTERN LK SUPERIOR BUT DESPITE THE APPROACHING
FRONT...MINIMAL LARGE SCALE FORCING IS RESULTING IN LITTLE IF ANY
SHRA/TSRA. WV LOOP AND REGIONAL RADAR SHOWS ONE MAIN SHORTWAVE IS
OVER NORTHERN ONTARIO WHILE OTHER STRONGER WAVE AND ASSOCIATED
FORCING IS SLIDING ALONG NEB/SDAKOTA BORDER. KEPT SMALL RISK FOR
SHRA OR TSRA IN THIS MORNING AS H925 THETA-E RIDGE SLIDES ACROSS AND
THERE IS WEAK H7 MOISTURE TRANSPORT/LIFT. BETTER CHANCE FOR SHRA/TSRA
IS THIS AFTN OVER CNTRL UPR MICHIGAN AS THE FRONT SETTLES ACROSS AND
INTERACTS WITH LAKE BREEZES. FRONTAL PASSAGE WILL BE MOST NOTABLE
NEAR LK SUPERIOR. PARTLY TO MOSTLY CLOUDY SKIES THIS MORNING WILL
STILL ALLOW MIXING TO AT LEAST H9 OR EVEN H875-H85 FARTHER INLAND.
EXPECT MAX TEMPS WELL INTO THE 70S...WITH LOW 80S SCNTRL. ONCE FRONT
SLIDES ACROSS NORTHERN UPR MICHIGAN THOUGH...WINDS TURN OFF LK
SUPERIOR AND TEMPS SHOULD TUMBLE INTO THE AFTN. INDICATED FALLING
TEMPS IN GRIDS...WITH READINGS NEAR LK SUPERIOR...ESPECIALLY EAST OF
KEWEENAW TOWARD GRAND MARAIS THIS AFTN POSSIBLY ONLY IN THE 50S
AFTER MIDDAY HIGHS IN THE 70S. CONVERGENCE WITH THE FRONT AND
INCREASING LARGER SCALE LIFT VIA APPROACHING SHORTWAVES FM THE
NORTHERN PLAINS SHOULD ALLOW FOR SHRA/TSRA TO EXPAND MID-LATE AFTN.
DEEP LAYER SHEAR IS OVER 40 KTS...WITH MLCAPES MAXING OUT IN THE
400-800J/KG RANGE. GIVEN THE SHEAR...IF ORGANIZED STORMS DEVELOP
THERE IS A SMALL RISK OF STRONG STORMS. H7 WINDS FM THE WEST AT 20
KTS...SO AREAS MOST LIKELY AFFECTED WOULD BE
MENOMINEE/DELTA/SOUTHERN SCHOOLCRAFT COUNTIES AS WELL AS NSH AREAS
OF NORTHERN LK MICHIGAN INCLUDING BAY OF GREEN BAY.

LATE THIS AFTN INTO THE EVENING...SHRA/TSRA CURRENTLY AFFECTING
NEB/IOWA WILL MAINLY BE TRACKING TO THE SOUTH OF UPR MICHIGAN CLOSER
TO EDGE OF MLCAPES UP TO 3000J/KG FM IOWA INTO ILLINOIS. SHORTWAVE
PRODUCING THE CONVECTION SHOULD COME CLOSE ENOUGH TO HAVE A CHANCE
FOR SHRA/TSRA OVER MAINLY THE SOUTH AND EAST CWA. ECMWF AND LOCAL
REGIONAL WRF WERE USED FOR THE FORECAST HERE...MAINLY BECAUSE THEY
WERE THE BEST FIT FOR A FARTHER SOUTH TRACK OF THE SHORTWAVE THIS
MORNING COMPARED TO THE WV LOOP AND PATTERN OF ONGOING SHRA/TSRA. BY
LATE EVENING...CHANCES TAPER DOWN...BUT THEN OVERNIGHT TONIGHT THE
FIRST STRONGER NORTHERN STREAM WAVE WILL BE FAST APPROACHING AS
UPPER LOW DROPS TOWARD THE UPPER GREAT LAKES. MAJORITY OF LIFT AND
DEEP MOISTURE WITH THE WAVE LIKELY STAYS OVER LK SUPERIOR AND TO THE
NORTH. WAVE GLANCES NORTHERN UPR MICHIGAN SO PUT SOME SLIGHT CHANCES
IN AFTER MIDNIGHT. ELEVATED CAPES UP TO 300J/KG JUSTIFY CARRYING
SOME TSRA AS WELL. SFC FRONT PUSHES ACROSS WESTERN LK SUPERIOR AND
EVENTUALLY THE KEWEENAW PENINSULA. SOUNDINGS SHOW WNW WINDS 20-25
KTS IN THE MIXED LAYER AS THE FRONT ARRIVES. COULD GET QUITE GUSTY
FOR A TIME TOWARD DAYBREAK ON ISLE ROYALE AND THE KEWEENAW PENINSULA
AS THE FRONT FIRST ARRIVES. TEMPS MOST AREAS TONIGHT WILL STAY MILD
IN THE MID 50S TO LOWER 60S AS THE COOLING REALLY DOES NOT KICK IN
UNTIL SUNDAY AND BEYOND.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 328 AM EDT SAT JUL 12 2014

NAM SHOWS A CLOSED 500 MB LOW OVER SOUTH CENTRAL CANADA 12Z SUN WITH
A 500 MB TROUGH DIGGING INTO THE GREAT LAKES REGION. UPPER AIR
PATTERN AMPLIFIES OVER THE AREA 12Z MON WITH THE LOW MOVING OVER THE
AREA ON MON. AS THE LOW MOVES OVER THE AREA ON MON...EXPECT SOME
INSTABILITY SHOWERS TO BREAK OUT WITH THE HIGHEST POPS DURING THE
PEAK DIURNAL HEATING. NAM SHOWS SOME DEEPER MOISTURE AND 850-500 MB
Q-VECTOR CONVERGENCE MOVING THROUGH THE AREA ON MON INTO MON NIGHT.

WILL HAVE SOME SMALL CHANCE POPS IN FOR THE ERN CWA SUN MORNING AND
THEN GO DRY FOR SUN AFTERNOON AND SUNDAY EVENING. WITH APPROACH OF
THE UPPER LEVEL LOW ON MON...WILL HAVE POPS INCREASING TO LIKELY IN
A FEW PLACES MON WITH PEAK DIURNAL HEATING HAVING THE HIGHEST POPS
IN THE AFTERNOON. WITH LOSS OF DIURNAL HEATING MON NIGHT...HAVE POPS
DECREASING BACK TO CHANCE TO SLIGHT CHANCES. OVERALL...DID NOT MAKE
TOO MANY CHANGES TO THE GOING FORECAST. TEMPERATURES WILL BEGIN THE
COOLING TREND THIS FORECAST PERIOD AND LOWERED HIGHS A BIT FOR SUN
THROUGH MON NIGHT.

IN THE EXTENDED...GFS AND ECMWF SHOW A DEEP 500 MB TROUGH AND CLOSED
LOW OVER THE ERN HALF OF NORTH AMERICA WITH VERY COLD TEMPERATURES
OVER THE AREA 12Z TUE. THE TROUGH REMAINS NEARLY STATIONARY INTO THU
BEFORE PATTERN MODIFICATION TAKES PLACE WITH THE TROUGH AND
AMPLIFICATION BREAKING DOWN. A RIDGE MOVES INTO THE ROCKIES 12Z FRI.
WHAT THIS WILL MEAN IS THE COOL CONDITIONS WILL CONTINUE FOR MOST OF
THE FORECAST PERIOD WITH A SLOW MODERATION IN TEMPERATURES. SFC
HIGH PRESSURE REMAINS IN CONTROL OF THE WEATHER AND LOOKS COOL AND
DRY FOR THE MOST PART. WILL KEEP SOME SMALL POPS IN FOR TUE WITH
DEPARTING UPPER LOW IN THE AREA.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 717 AM EDT SAT JUL 12 2014

AS WINDS SHIFT AROUND TO A W TO NW DIRECTION BEHIND WEAK COLD FROPA
THIS MORNING...THE UPSLOPE WINDS AT KIWD/KCMX MAY RESULT IN A PERIOD
OF IFR CONDITIONS. MVFR CONDITIONS MAY DEVELOP AT KSAW. ALL TERMINALS
SHOULD RETURN TO VFR LATE THIS MORNING INTO THE AFTN. THERE MAY BE
SHRA/TSRA AROUND KSAW THIS AFTN...BUT LOCATION AND COVERAGE OF ANY
SHRA/TSRA DEVELOPMENT REMAINS TOO UNCERTAIN AT THIS POINT TO INCLUDE
A MENTION IN FCST. NEXT ISSUE LATER TONIGHT IS STRONGER FROPA. WINDS
MAY GUST OVER 20 KTS LATE AT KCMX AS THE FRONT MOVES THROUGH. &&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EDT SAT JUL 12 2014

SOUTH WINDS OF UP TO 20 KTS SHIFT TO THE NORTHWEST TODAY AS FRONT
WORKS ACROSS LK SUPERIOR. WINDS BECOME MORE SOUTHWEST THIS EVENING
THEN SHIFT SHARPLY TO THE WEST LATE TONIGHT AS STRONGER COLD FRONT
ARRIVES. MAY SEE WINDS UP TO 25 KTS AT LEAST BRIEFLY LATE TONIGHT
OVER WEST AND NORTH CENTRAL LK SUPERIOR BEHIND THE FRONT. AREAS OF
FOG ARE CURRENTLY OVER LK SUPERIOR AND THIS WILL DISSIPATE ON SUNDAY
IN WAKE OF THE STRONGER FRONT. EXPECT NORTHWEST WINDS TO 20 KTS AT
TIMES INTO EARLY THIS WEEK IN WAKE OF THE COLD FRONT AND AS HIGH
PRESSURE BUILDS OVER THE NORTHERN PLAINS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...JLA
LONG TERM...07
AVIATION...JLA
MARINE...JLA






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