Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 240651
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
251 AM EDT SUN MAY 24 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 251 AM EDT SUN MAY 24 2015

UPPER AIR PATTERN CONSISTS OF A CLOSED 500 MB LOW OVER THE CENTRAL
ROCKIES WITH A SHORTWAVE RIDGE OVER THE SOUTHEAST AND GREAT LAKES
REGION. THE RIDGE MOVES SLOWLY EAST TODAY WHILE A TROUGH MOVES INTO
THE PLAINS AND THIS TROUGH AFFECTS THE UPPER GREAT LAKES TONIGHT.

NAM BRINGS IN SOME 850-500 MB Q-VECTOR CONVERGENCE AND SOME DEEPER
MOISTURE INTO THE CWA TONIGHT. GFS AND ECMWF DO ABOUT THE SAME THING
AS WELL. OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING
FORECAST EXCEPT TO DELAY POPS FOR LATE THIS AFTERNOON. SOME OF THE
MODELS ARE SHOWING SOME CONVECTION THIS AFTERNOON WITH LAKE
BREEZES...BUT THINKING IS THIS IS OVERDONE WITH A VERY DRY AIRMASS
IN PLACE...WOULD BE HARD TO GET ANY CONVECTION GOING.
ECMWF...CANADIAN...NAM ALL HAVE BACKED OFF ON ANY PCPN FOR THIS
AFTERNOON AND WILL GO WITH THAT IDEA. DID BRING IN SOME CATEGORICAL
POPS FOR TONIGHT AS A BAND OF HEAVY RAIN MOVES THROUGH THE AREA.
WITH THIS RAIN...FOG BECOMES A POSSIBILITY ESPECIALLY IN THE LAKES
AND KEPT THAT IN THERE AS WELL. WILL BECOME A VERY GOOD POSSIBILITY
WHEN RAIN FALLS INTO THE LAKES. KEPT TEMPERATURES PRETTY SIMILAR TO
GOING FORECAST EXCEPT WARMED UP LOWS A BIT TONIGHT WITH PLENTY OF
CLOUDS IN THE AREA...TEMPERATURES SHOULD BE FAIRLY UNIFORM WITH
COOLEST READINGS NEAR LAKE MICHIGAN.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 357 PM EDT SAT MAY 23 2015

UPPER AIR PATTERN TO START LONG TERM SHOWS LARGER TROUGH FM WESTERN
CANADA INTO THE PLAIN STATES. RIDGE ALOFT CENTERED OVER SE CONUS
EXTENDS RIDGE BACK OVER GREAT LAKES. SHORTWAVE ON LEADING EDGE OF
WESTERN CONUS TROUGH LIFTS TOWARD UPPER MISSISSIPPI RIVER VALLEY ON
SUNDAY NIGHT. SFC LOW AND ASSOCIATED WARM AIR AND MOISTURE ADVECTION
AHEAD OF THE WAVE...SEEN IN H85-H7 MOISTURE TRANSPORT FIELDS...
COMBINES WITH LARGER SCALE ASCENT IN RIGHT ENTRANCE REGION OF 130+
KT JET STREAK FM NORTHERN ONTARIO TO NEW ENGLAND TO BRING A PERIOD
OF SHOWERS ACROSS CWA LATER SUNDAY NIGHT THROUGH EARLY MONDAY AFTN.
SHOWERS SHOULD END FIRST ALONG THE WI BORDER ON MONDAY MORNING AND
THEN ALONG LK SUPERIOR IN THE AFTERNOON. ELEVATED INSTABILITY SHOWS
UP SOME WITH SI/S LOWERING TOWARD 0-1C BUT THAT ARRIVES AFTER MAIN
FORCING MOVES ACROSS. NOT EXPECTING MUCH FOR TSRA AT THIS POINT.
RAIN COULD FALL HEAVY AT TIMES GIVEN PWATS BY 12Z MONDAY AT KGRB
THAT WOULD BE IN THE HIGHEST 5 PCT COMPARED TO CLIMO FOR THE DATE.
ESE-E WINDS AHEAD OF THE LOW AND ASSOCIATED WARM FRONT/ADVECTION OF
HIGHER DWPNTS AND RAIN OVER ALL THE AREA POINTS TO FOG OVER THE GREAT
LAKES/ADJACENT SHORELINES AND ALSO OVER KEWEENAW PENINSULA AND HIGHER
TERRAIN OF CNTRL CWA BTWN KIMT AND MARQUETTE.

UNCERTAINTY IN POPS/WX LATE MONDAY AFTN INTO MONDAY EVENING BUT
GENERALLY EXPECT MAINLY DRY WEATHER DUE TO MID-LEVEL SUBSIDENCE AND
DRYING THAT MOVES OVERHEAD IN WAKE OF PRIMARY SHORTWAVE. LIKELY WILL
BE LINGERING LOW-LEVEL MOISTURE...THOUGH SSW BLYR WINDS DO NOT FAVOR
PERSISTENT LOW CLOUDS SINCE THAT PROVIDES MINIMAL TRAJECTORIES OFF
THE ADDITIONAL MOISTURE FM THE GREAT LAKES. GIVEN THE SSW WINDS ALSO
DIMINISHED FOG ON THE LAND AREAS...AT LEAST AWAY FM LK MICHIGAN AND
THE OPEN WATERS OF LK SUPERIOR. NAM INDICATES ENOUGH ADDITIONAL MID-
LEVEL MOSITURE MOVES IN BY EVENING TO COMBINE WITH INCREASING
INSTABILITY TO PRODUCE CONVECTION. SINCE NAM IS ONLY MODEL
INDICATING THIS AT PRESENT...WILL DISCOUNT THAT IDEA AND CONTINUE TO
DOWNPLAY POPS. TEMPS ON MONDAY DEPEND ON EXTENT OF CLEARING. WILL
NOT TAKE MUCH TO BOOST TEMPS WITH WARM TEMPS ALOFT IN WARM SECTOR OF
SFC LOW THAT WILL BE NW OF LK SUPERIOR BY 00Z TUE. MIXING TO H9
RESULTS IN MAX TEMPS INTO THE 70S...SO INCREASED MAX TEMPS SLIGHTLY.

LATER MONDAY NIGHT INTO TUESDAY...MAIN FRONT SWINGS ACROSS UPPER
GREAT LAKES AS SFC LOW TRACKS NORTH OF LK SUPERIOR. VARYING IDEAS ON
STRENGTH AND WESTWARD EXTENT OF SHORTWAVE LIFTING NORTHEAST ALONG THE
FRONT. GFS MOST AGRESSIVE WITH THAT IDEA WHERE ECMWF AND GEM ARE NOT
AS BULLISH. KEPT IT SIMPLE AND RETAINED LOW CHANCE POPS ALONG AND
AHEAD OF FRONT MOVING THROUGH. BASED ON SW H85 THETA-E ADVECTION
AHEAD OF THE FRONT AND AT LEAST A FEW HUNDRED J/KG OF ELEVATED
CAPE...ADDED SLIGHT CHANCE FOR THUNDER OVER EAST HALF OF CWA MONDAY
NIGHT INTO TUESDAY. BASED ON FORECAST SOUNDINGS...KEPT THE FOG GOING
OVER THE GREAT LAKES AND NEAR LK MICHIGAN AT LEAST FOR THE MORNING ON
TUESDAY. ENOUGH DRYING DEVELOPS LATER IN THE DAY TO DISSIPATE THE
FOG. TEMPS ON TUESDAY COOLEST OVER NW CWA AND NEAR LK MICHIGAN WITH
MORE PRONOUNCED ONSHORE FLOW. EVEN FOR THOSE AREAS THOUGH...TEMPS
WILL BE IN THE 60S. MAX TEMPS REACH MID 70S INLAND TOWARD WI BORDER.

REST OF EXTENDED INDICATES MAINLY DRY WEATHER FOR WEDNESDAY WITH
ANOTHER FRONT BRINGING SMALL CHANCES FOR RAIN THURSDAY INTO FRIDAY.
BASED ON LATEST ECMWF WHICH TRENDED TOWARD LAST COUPLE RUNS OF
GFS...APPEARS THAT NEXT WEEKEND WOULD BE DRIER AS MORE ACTIVE
FRONTAL BOUNDARY SETTLES OVER THE LOWER GREAT LAKES AND OHIO VALLEY.
KEPT LOW CHANCES THAT CONSENSUS GAVE ATTM...BUT IF THESE MODEL
TRENDS CONTINUE...LATER SHIFTS MAY BE ABLE TO REMOVE POPS FM NEXT
SATURDAY. OVERALL TEMPS THROUGH THE WEEK SHOULD BE AROUND NORMAL.
GIVEN THE LACK OF REAL COOLING AT H85 OTHER THAN WITH THE FRONT
MOVING THROUGH ON TUESDAY...COULD SEE TEMPS MOST DAYS TUESDAY
THROUGH THURSDAY PUSH SLIGHTLY ABOVE NORMAL IN THE MID-UPR 70S.
NIGHTTIME LOWS SHOULD STAY SAFELY ABOVE FREEZING...WITH MAINLY 40S
TO AROUND 50 DEGREES EXPECTED. COOLER TEMPS MOVE BACK IN NEXT
WEEKEND AS COOLER CANADIAN HIGH PRESSURE SETTLES OVER THE AREA.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 106 AM EDT SUN MAY 24 2015

ALTHOUGH THERE WILL BE AN INCREASE IN MID AND HIGH CLOUDS...DRY AIR
WILL LINGER AT THE LOWER LEVELS THRU AT LEAST EARLY THIS EVENING...
RESULTING IN VFR CONDITIONS PREVAILING AT KIWD/KCMX/KSAW. LATE THIS
EVENING AND JUST BEYOND THIS FCST PERIOD...AN AREA OF SHOWERS WILL
LIFT N INTO THE UPPER GREAT LAKES...BRINGING DETERIORATING
CONDITIONS. PCPN SHOULD ADVANCE AS FAR N AND NE AS KIWD JUST BEFORE
THE END OF THIS FCST PERIOD. BEYOND THIS FCST PERIOD...CONDITIONS
WILL LIKELY FALL TO IFR OR LOWER AT ALL TERMINALS BY SUNRISE MON.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 251 AM EDT SUN MAY 24 2015

WINDS REMAIN AT OR LESS THAN 20 KTS THIS FORECAST PERIOD. FOG SHOULD
DEVELOP TONIGHT AND THIS WILL LINGER OVER MUCH OF LAKE SUPERIOR
THROUGH WEDNESDAY MORNING. FOG MAY BECOME DENSE AT TIMES.
&&

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

$$

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


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