Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 190525
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
125 AM EDT FRI SEP 19 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 357 PM EDT THU SEP 18 2014

GENERALLY QUIET WEATHER IS EXPECTED THROUGH TONIGHT BEFORE WINDS
INCREASE AHEAD OF AN APPROACHING FRONTAL SYSTEM ON FRIDAY. SOME RAIN
SHOWERS WILL THEN MOVE OVER WESTERN UPPER MI FRIDAY AFTERNOON.

SURFACE HIGH PRESSURE CENTERED JUST EAST OF LAKE SUPERIOR LATE THIS
AFTERNOON WILL GRADUALLY MOVE EAST THIS EVENING AS LOW PRESSURE
DEVELOPS OVER SOUTHERN SASKATCHEWAN. MEANWHILE...A MID-LEVEL RIDGE
OVER THE NORTH-CENTRAL CONUS WILL BEGIN TO FLATTEN IN RESPONSE TO A
TROUGH OVER THE NW STATES. AS THIS OCCURS...A WEAK RIPPLE IN THE
GENERALLY ZONAL FLOW WILL BE THE FOCUS FOR PRECIP CHANCES ON FRIDAY
AFTERNOON.

TONIGHT...LOW-LEVEL MOISTURE ASSOCIATED WITH CLOUDS THAT HAVE BEEN
STUBBORN TO DISSIPATE ACROSS NORTHERN WI TODAY WILL SLOWLY WORK
NORTHWARD TONIGHT ON RETURN FLOW BEHIND THE DEPARTING HIGH.
HOWEVER...A FEW HOURS OF CLEARING IN THE EVENING AHEAD OF THE CLOUDS
WILL ALLOW FOR GOOD COOLING ACROSS MUCH OF THE INTERIOR CENTRAL AND
EAST. ARRIVAL OF THE CLOUDS AND INCREASING GRADIENT WINDS OVERNIGHT
WILL LIMIT COOLING AND LIKELY ALLOW TEMPS TO RISE DURING THE EARLY
MORNING HOURS. AM NOT TOO CONCERNED ABOUT FROST...THOUGH A FEW
PATCHES WILL BE POSSIBLE FOR THE TYPICAL COLD SPOTS ACROSS THE
INTERIOR EAST HALF.

FRIDAY...LOW-LEVEL MOISTURE WILL CONTINUE TO SURGE ACROSS THE
AREA...LEADING TO OVERALL CLOUDINESS THROUGHOUT THE DAY.
HOWEVER...THE MAIN STORY FOR FRIDAY WILL BE THE WIND. AN INCREASING
PRESSURE GRADIENT AHEAD OF THE LOW COMBINED WITH MODEST PRESSURE
FALLS NORTH OF LAKE SUPERIOR SHOULD ALLOW FOR A STEADY 15-20MPH
SOUTH TO SSW WIND ACROSS MUCH OF UPPER MI LATE MORNING INTO THE
AFTERNOON. 1KM AGL WINDS APPROACHING 50S KTS AHEAD OF THE LOW-LEVEL
TROUGH WILL MAKE THINGS INTERESTING IN THE AFTERNOON. IF ENOUGH
MIXING OCCURS...SOME OF THAT MOMENTUM WILL BE BROUGHT TO THE SFC.
CURRENTLY THINKING GUSTS OF 30-35MPH WILL BE POSSIBLE...ESPECIALLY
FOR THE DOWNSLOPE AREAS CENTRAL AND EAST ALONG LAKE SUPERIOR. MAY
EVEN SEE A FEW GUSTS HIGHER THAN THAT IF ENOUGH MIXING OCCURS BY MID
AFTERNOON.

AS THE WEAK SHORTWAVE AND ASSOCIATED LOW-LEVEL TROUGH APPROACH THE
AREA...RAIN SHOWERS WILL BE INCREASING IN COVERAGE ACROSS THE
WESTERN CWA IN THE AFTERNOON. DELAYED AND CUT BACK ON POPS SOMEWHAT
AS THE RIGHT ENTRANCE OF AN UPPER JET COUNTERACTS SOME OF THE MORE
FAVORABLE LOW AND MID-LEVEL DYNAMICS. ANY PRECIP SHOULD HOLD OFF
ACROSS THE WESTERN CWA UNTIL AFTER NOON...AND THE CENTRAL CWA UNTIL
LATE AFTERNOON. HOWEVER...WITH PLENTY OF LOW-LEVEL MOISTURE...A FEW
PATCHES OF DRIZZLE WILL BE POSSIBLE IN THE MORNING ACROSS THE WEST
HALF.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 329 PM EDT THU SEP 18 2014

UPPER LEVEL PATTERN TRANSITIONS FROM NORTHWEST FLOW ON BACK SIDE OF
TROUGHING OVER EASTERN CANADA TO MORE ZONAL FLOW BY THIS WEEKEND.
MAIN REASON THIS OCCURS IS 125+ KT H25 JET STREAK PLOWING ACROSS
PACIFIC TOWARD BRITISH COLUMBIA AND PACIFIC NORTHWEST. AS THIS JET
ENERGY REACHES NORTHERN PLAINS ON FRIDAY IT WILL HELP DEVELOP TROUGH
ALOFT OVER NORTHERN ONTARIO AND THE LK SUPERIOR REGION. INITIAL WAVE
ON LEADING EDGE OF THIS TROUGH WORKS THROUGH FRIDAY NIGHT INTO
SATURDAY MORNING AND THIS SHOULD BE WHEN MAJORITY OF RAIN OCCURS.
AT THE SFC...A TROUGH WITH A WIND SHIFT AND LOW-LEVEL DRYING WILL
MOVE THROUGH. ANOTHER SHORTWAVE IS FORECAST TO SWING THROUGH
SATURDAY NIGHT INTO SUNDAY MORNING. A STRONGER SFC COLD FRONT
WILL ACCOMPANY THAT SHORTWAVE. WARMER THAN NORMAL TEMPS FRIDAY NIGHT
INTO SATURDAY...BEFORE TEMPERATURES FALL BACK BELOW NORMAL ON SUNDAY.
LOW TEMPS ON FRIDAY NIGHT MAY NOT FALL BLO 60 DEGREES IN SOME AREAS
AS THE WARM SOUTH/SOUTHWEST WINDS PERSIST. THOUGH THERE COULD BE LOW
CLOUDS AROUND TO START THE DAY ON SATURDAY...APPEARS THERE WILL BE
ENOUGH MIXING BY LATE MORNING/EARLY AFTN TO RESULT IN MIXING HEIGHTS
BUILDING TO AT LEAST TO H9/H875 WITH HIGHS POTENTIALLY WELL INTO THE
70S IF THERE IS AT LEAST PARTIAL SUNSHINE. MUCH DIFFERENT STORY ON
SUNDAY WITH HIGHS NEAR LK SUPERIOR BARELY REACHING ABOVE 50 DEGREES
AND ONLY INTO THE 50S FARTHER INLAND AND OVER SOUTHERN CWA AND NEAR
LK MICHIGAN. NOTHING TOO HIGH IMPACT IN TERMS OF NORTH TO NORTHWEST
WINDS IN WAKE OF THE COLD FRONT ON SUNDAY...WITH 20-30 MPH ON LK
SUPERIOR AND NEAR THE SHORE...NOTHING TOO ATYPICAL FOR SEPTEMBER.

BACK TO THE IMPACTS TIED TO SYSTEM MOVING THROUGH FRIDAY NIGHT
THROUGH SATURDAY. DOES NOT APPEAR THAT HEAVY RAIN WILL BE A LARGE
THREAT WITH THIS SYSTEM...MAINLY BECAUSE THE GREATEST SURGE OF H85
THETA-E ADVECTION AND PWATS NEAR 200 PCT OF NORMAL ONLY OCCURS FOR
BRIEF PERIOD ON FRIDAY NIGHT BEFORE THE H85 JET VEERS MORE WEST BY
12Z SATURDAY. SOUTH WINDS AHEAD THE INITIAL LOW PRESSURE SYSTEM AND
SFC TROUGH WILL BE STRONG AND GUSTY FRIDAY EVENING. SOUNDINGS SHOW
STABLE PROFILE BLO AN INVERSION AT H9-H85...BUT BLYR WINDS ARE STILL
IN THE 40-50 MPH RANGE. PRESSURE FALLS OVER EASTERN LK SUPERIOR TO
JAMES BAY WILL ENHANCE THE SOUTH WINDS. OVERALL...COULD SEE SOUTH
WINDS GUSTING OVER 35 MPH VCNTY OF EASTERN LK SUPERIOR AND NORTHERN
LK MICHIGAN WITH SOME GUSTS 30-35 MPH ON THE LAND AREAS OF THE
EASTERN CWA. ATTM THINK THE WIND GUSTS SHOULD STAY BELOW ADVY
CRITERIA OF 45 MPH.

ADDITIONAL IMPACT COULD BE STRONG OR POSSIBLE SEVERE STORMS ON
SATURDAY AFTN AS SFC TROUGH CROSSES THE AREA ALONG WITH SHORTWAVE
AND PUSH OF MID-LEVEL MOISTURE. MLCAPES UP OVER 1500J/KG AND WITH
THE UPPER TROUGH IN THE VCNTY...0-6KM SHEAR IS OVER 40 KTS. NAM
QUITE AGGRESSIVE DEPICTING BUILD UP OF INSTABILITY...WHILE THE GFS
AND ECMWF ARE NOT AS MUCH. SREF PROBABILITIES OF MUCAPE OVER
1000J/KG ALONG WITH SHEAR OVER 30 KTS SHOW SOME INCREASE 15-21Z
SATURDAY OVER MAINLY THE SCNTRL CWA...BUT STILL REMAIN MAINLY BLO 10
PCT. FREEZING LEVEL IS 9-11KFT AND HEIGHT THAT CORES ALOFT WOULD
HAVE TO REACH TO POSSIBLY PRODUCE SEVERE 1 INCH HAIL IS 27-30KFT...
SO LARGE HAIL IS A POSSIBILITY. LOW-LEVEL LAPSE RATES NOT THAT
STEEP...BUT WITH THE DRY AIR H9-H7 AND STRONG WINDS H7-H5...SUPPOSE
STRONG WIND GUSTS COULD MAKE IT TOO SFC. PRIMARY AREA HIGHLIGHTED IN
SPC DAY3 OUTLOOK IS FARTHER EAST AND SOUTH AHEAD OF COLD FRONT
WITHIN SW H85 JET AND WHERE THE SFC DWPNTS ARE WELL INTO THE 60S.
DOES SEEM IF TIMING WORKS OUT WHERE SOME INSTABILITY CAN BUILD OVER
CNTRL UPR MICHIGAN AHEAD OF THE SHORTWAVE...THERE IS ENOUGH OF A
RISK FOR SEVERE...SO WILL CONTINUE TO MENTION IN THE HWO.

INTO SATURDAY NIGHT...COULD STILL SEE SOME TSRA WITH COMBINATION OF
SHORTWAVE AND STEEP H7-H4 LAPSE RATES/COLD POCKET AT H5/. NO STRONG
STORMS EXPECTED THROUGH AS EFFECTIVE SHEAR DIMINISHES TO LESS THAN
20 KTS BY THIS TIME. BESIDES THE CHILL THAT WILL BE IN THE AIR ON
SUNDAY...ANOTHER SHORTWAVE DROPPING THROUGH IN NW FLOW ALOFT AND THE
H85-H5 THERMAL TROUGHING/EXTENSIVE MOISTURE WILL LIKELY BE ENOUGH TO
KICK OFF SOME SHOWERS OVER MAINLY INLAND AREAS. WATER TEMPS OVER
MUCH OF LK SUPERIOR ARE IN THE 6-8C RANGE BASED ON BUOYS AND SHIP
REPORTS. IMMEDIATE NSH AREAS OF SCNTRL LK SUPERIOR MAY BE OVER 10C
IN SOME SPOTS BUT THAT IS LOCALIZED. THEREFORE WITH H85 TEMPS STAYING
ABOVE 0C WILL NOT BE LOOKING AT MUCH LAKE ENHANCEMENT ESPECIALLY AS
LOW-LEVEL FLOW WILL BE TRENDING MORE ANTICYCLONIC THROUGH THE DAY
WITH SFC RIDGE EXPANDING EAST FM THE NORTHERN PLAINS.

EXTENDED...TROUGHING ALOFT DOMINATES EARLY NEXT WEEK. HINT OF
STRONGER SHORTWAVE AND RE-INFORCING SFC TROUGH DROPPING ACROSS
THE UPPER GREAT LAKES ON MONDAY. GFS FARTHER WEST WITH THE WAVE AND
WOULD INDICATE AT LEAST ISOLD SHRA ON MONDAY. ECMWF AND GEM-NH AND
PREVIOUS FORECASTS...KEEP BULK OF WAVE AND MOISTURE TOO FAR EAST TO
RESULT IN MUCH SHRA. SINCE GFS IS ALSO TRENDING THIS WAY WITH 12Z
RUN...WILL KEEP IT DRY ATTM. HIGH PRESSURE INITIALLY AT THE SFC THEN
ALOFT AS WELL BUILDS ACROSS REGION TUESDAY THROUGH THURSDAY. PWATS
LESS THAN 50 PCT OF NORMAL AND AFTN SFC DWPNTS IN THE 30S INDICATE
THERE COULD BE FROST TUESDAY NIGHT/WEDNESDAY NIGHT FOR ALL INLAND
AREAS AND MAYBE EVEN THURSDAY NIGHT FOR INLAND AREAS OF EASTERN CWA.
DAYTIME TEMPS WILL LIKELY BE AT OR ABOVE NORMAL...ESPECIALLY
WEDNESDAY INTO THURSDAY AS WARMER AIR WORKS IN ALOFT /H85 TEMPS OVER
10C/ WITH THE BUILDING UPPER RIDGE. SINCE IT LOOKS LIKE THERE WILL
BE LITTLE IN WAY OF CLOUD COVER EITHER DAY...TEMPS COULD EVEN REACH
THE 70S. NORMAL HIGHS FOR MID-LATE SEPTEMBER ARE IN THE MID TO UPPER
60S.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 121 AM EDT FRI SEP 19 2014

VEERING LOW-LEVEL WINDS IN RESPONSE TO DEPARTING SFC HIGH PRES WILL
BRING TRAJECTORIES OFF LAKE MICHIGAN FOR A TIME EARLY THIS MORNING.
THIS UPSLOPE FLOW OF LAKE MOISTENED AIR INTO COOLER AIR OVER UPPER
MI SHOULD RESULT IN STRATUS (IFR CIGS) SPREADING N TO KSAW TOWARD
DAYBREAK. THESE LOWER CLOUDS SHOULD LIFT AND SCATTER OUT MID MORNING
THRU EARLY AFTN AT KSAW. WHILE S WINDS ARE DOWNSLOPING AT KIWD...LOW
MVFR CIGS MAY DEVELOP THERE AS WELL TOWARD DAYBREAK AND THRU MID
MORNING. WITH FLOW UNDERGOING MORE SUBSTANTIAL DOWNSLOPING BEFORE
REACHING KCMX...OPTED TO MAINTAIN VFR CONDITIONS AT THAT TERMINAL.
OTHERWISE...TIGHTENING PRES GRADIENT AHEAD OF APPROACHING SFC TROF
WILL BRING GUSTY S WINDS TO ALL TERMINALS TODAY. FLOW IS ESPECIALLY
FAVORABLE FOR KSAW...AND EXPECT GUSTS TO 30KT OR PERHAPS HIGHER
THERE THIS AFTN. WITH UNCERTAIN COVERAGE OF SHRA AHEAD OF TROF...
ONLY VCSH WAS INCLUDED IN FCST AT KIWD/KCMX LATE IN THE AFTN/EARLY
EVENING. BETTER CHC OF SHRA AND PERHAPS A TSTM WILL ARRIVE AT
KCMX/KIWD DURING THE EVENING. CONDITIONS MAY FALL TO MVFR AT THAT
TIME.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 357 PM EDT THU SEP 18 2014

SOUTHERLY WINDS WILL INCREASE TONIGHT AND FRIDAY WITH LOW PRESSURE
APPROACHING FROM THE WEST AND HIGH PRESSURE JUST EAST OF LAKE
SUPERIOR SHIFTING EASTWARD. 20-30KT SOUTHERLY WINDS ARE EXPECTED
ACROSS ALL OF LAKE SUPERIOR BY LATE TONIGHT...AND CENTRAL AND
EASTERN LAKE SUPERIOR THROUGH FRIDAY. A FEW GALES TO 35 KNOTS WILL
BE POSSIBLE FOR THE HIGHER PLATFORMS AND CLOSER TO THE UPPER MI
SHORELINE...BUT OVERALL COVERAGE AND A FAIRLY STABLE NEAR-WATER
LAYER PRECLUDE THE NEED FOR A GALE WARNING AT THIS TIME. THE 20-30KT
SOUTH WINDS WILL GRADUALLY DIMINISH ACROSS THE EAST HALF OF THE LAKE
FRIDAY NIGHT THROUGH SATURDAY AS THE TROUGH MOVES ACROSS LAKE
SUPERIOR. EXPECT A PERIOD OF WESTERLY WINDS OF UP TO 20 KNOTS
SATURDAY AFTERNOON AND NW WINDS TO 20 KNOTS SATURDAY NIGHT BEHIND
THIS TROUGH. WINDS WILL REMAIN UNDER 20 KNOTS THROUGH MUCH OF NEXT
WEEK AS A SERIES OF HIGH PRESSURE SYSTEMS MOVES OVER THE UPPER GREAT
LAKES. THE ONE EXCEPTION WILL BE THE CHANCE OF NORTH WINDS UP TO 25
KNOTS MONDAY AFTERNOON AND EVENING BEHIND A QUICK-MOVING LOW
PRESSURE TROUGH.
&&

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

$$

SHORT TERM...KLUBER
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...KLUBER







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