Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 240921
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
421 AM EST SAT JAN 24 2015

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 300 PM EST FRI JAN 23 2015

REMNANT SYNOPTIC SNOW FROM A CLIPPER SYSTEM THAT MOVED THROUGH TODAY
IS NOW EXITING THE SERN CWA. SNOW...RAIN...FREEZING
RAIN...SLEET...DRIZZLE AND FREEZING DRIZZLE HAVE ALL BEEN OBSERVED
ACROSS PARTS OF THE CWA TODAY...MAKING FOR QUITE A COMPLICATED PTYPE
FORECAST. ATTENTION HAS NOW TURNED TO MINOR PRECIP POTENTIAL AS LOW
LEVEL MOISTURE SLIDES IN FROM THE NNW /ALREADY ACROSS MUCH OF WRN
AND NRN LAKE SUPERIOR/ ALONG WITH A BURST OF MINOR SNOW ALONG A COLD
FRONT THAT WILL MOVE THROUGH FROM LATE TONIGHT INTO SAT MORNING.

WITH THE DGZ BEING ALOFT AND DRY BEHIND THE REMNANT SYNOPTIC
PRECIP...HAVE DRIZZLE/FREEZING DRIZZLE DEVELOPING IN UPSLOPE NW WIND
AREAS OVER THE NEXT FEW HOURS. THE TOP OF THE MOIST PORTION OF THE
PROFILE LOOKS TO BE JUST AT OR NEAR THE BOTTOM OF THE DGZ AFTER 00Z
TONIGHT...WHICH LEADS TO MORE UNCERTAINTY WITH PTYPE SO WENT TO MORE
OF A DRIZZLE/FREEZING DRIZZLE AND SNOW MIX AT THAT POINT. A COLD
FRONT WILL MOVE N-S THROUGH THE CWA BETWEEN ROUGHLY 12Z AND 18Z
SAT...BRINGING GREATER MOISTURE AND FORCING ALONG THE FRONT AND ALSO
LOWERING THE DGZ AS COLDER AIR PUSHES IN. 850MB TEMPS LOOK TO FALL
FROM AROUND -4C AT 00Z SAT TO -14C AT 00Z SUN. HAVE PRECIP
TRANSITIONING TO SNOW ALONG AND BEHIND THE FRONT. OVERALL...ONLY
EXPECT MINOR ICE AND SNOW ACCUMULATIONS. RELATIVELY WARM SFC TEMPS
WILL CONTINUE TO MAKE FOR EFFECTIVE ROAD TREATMENTS THROUGH SAT
MORNING...BUT UNTREATED ROADS COULD BE ICY. TEMPS WILL FALL THROUGH
THE DAY OVER NRN UPPER MI. OVER SRN UPPER MI...TEMPS WILL BE STEADY
THROUGH THE MORNING BEFORE STARTING TO FALL AFTER FROPA.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 411 AM EST SAT JAN 24 2015

MAIN FCST CONCERNS IN THE LONG TERM WL BE POPS RELATED TO CLIPPER
SHRTWV FCST TO DIVE SEWD THRU THE UPR MS RIVER VALLEY ON MON/MON NGT
AS A RELATIVELY BENIGN WX PATTERN DOMINATES THE MEDIUM AND EXTENDED
RANGE. WHILE THE FLOW LATE THIS WEEKEND/EARLY NEXT WL FEATURE A NW
FLOW ALF BTWN A HI AMPLITUDE WRN NAMERICA RDG AND A DEEP ERN TROF...
THE CORE OF THE COLDEST AIR WL REMAIN OVER QUEBEC. THE LONGER RANGE
GUIDANCE CONTINUES TO SHOW THE PATTERN WL BECOME A BIT LESS
AMPLIFIED BY THE MIDDLE OF THE COMING WEEK...BUT A TREND TOWARD A
MORE PERSISTENT HIER AMPLITUDE WRN RDG THAT MAINTAINS A MORE NW FLOW
SUGGESTS ANY WARMING AT MID WEEK WL BE BRIEF. TOWARD THE END OF THE
WEEK...THE LONGER RANGE MODELS SHOW THE PATTERN REAMPLIFYING WITH A
DEEP ERN TROF ALLOWING A RETURN OF SOME VERY COLD ARCTIC AIR.

SUN...UPR MI WL BE DOMINATED BY A CHILLY NE FLOW BTWN HI PRES BLDG
SLOWLY SE THRU NW ONTARIO AND DEPARTING CLIPPER SFC LO DIVING SEWD
INTO THE OH RIVER VALLEY. FCST H85 TEMPS BTWN -14C AND -16C WL BE
COLD ENUF TO SUPPORT SOME LES...BUT LO INVRN BASE FCST BTWN H875-9
AS WELL AS ACYC/DIFFLUENT NATURE OF THE LLVL FLOW WL GREATLY LIMIT
SN SHOWER COVERAGE/INTENSITY EVEN THOUGH MUCH OF THE RELATIVELY
SHALLOW CONVECTIVE LYR WL BE WITHIN THE DGZ. WL RETAIN SOME CHC POPS
OVER THE NCENTRAL CWA WHERE THE FCST NE FLOW WL UPSLOPE. OVER THE
E...SHORTER OVERWATER FETCH AND DRYNESS OF THE INCOMING AIRMASS
/PWAT FCST UNDER 0.10 INCH/ WL ALLOW FOR A GOOD DEAL OF SUNSHINE.
ANY LES WL TEND TO DIMINISH LATER IN THE DAY WITH CLOSER APRCH OF
SFC HI PRES RDG/WEAKER UPSLOPE WINDS. HI TEMPS WL BE HARD PRESSED TO
RISE OUT OF THE TEENS EVEN WHERE THERE IS MORE SUNSHINE.

SUN NGT...SFC HI PRES RDG ON THE SW FLANK OF MAIN HI CENTER MOVING
INTO SW QUEBEC IS FCST TO DRIFT OVER UPR MI IN THE EVNG...ENDING ANY
LES AS THE FLOW SHIFTS TO THE SSW OVERNGT BTWN THE DEPARTING RDG TO
THE SE AND ANOTHER CLIPPER SHRTWV DIGGING SEWD THRU SCENTRAL CANADA.
ALTHOUGH THE LO CLDS MAY CLR OUT...THERE WL BE AN INCRS IN HIER CLD
LATE AS AREA OF DEEP LYR QVECTOR CNVGC/ISENTROPIC ASCENT IN ADVANCE
OF THE NEXT CLIPPER SHRTWV DROPPING SEWD OUT OF SCENTRAL CANADA
INVADES THE UPR LKS. MOST OF THE MODELS SHOW THE LEADING EDGE OF QPF
REACHING THE WRN CWA TOWARD 12Z...SO WL RETAIN SOME LO CHC POPS
THERE LATE. EXPECT THE LOWEST MIN TEMPS BLO ZERO/NEAR THE LO END OF
GUIDANCE OVER THE E CLOSER TO THE HI CENTER/CORE OF DRIER AIR AND
WHERE ANY HIER CLDS ASSOCIATED WITH THE CLIPPER WL BE LATER TO
ARRIVE.

MON/MON NGT...WHILE THE 00Z NAM/GFS INDICATE THE INCOMING CLIPPER
SHRTWV/AREA OF DEEP LYR QVECTOR CNVGC WL MOVE INTO THE UPR LKS ON
MON WITH AXIS OF HIER QPF UP TO ABOUT 0.20 INCH IMPACTING THE CWA
BEFORE TRACKING INTO LOWER MI ON MON NGT...THE 00Z CNDN AND 12Z
ECWMF RUNS SHOW A TRACK A BIT FARTHER TO THE SW...WITH AXIS OF HIER
QPF MISSING UPR MI. THIS FARTHER W SCENARIO APPEARS TO BE MORE IN
LINE WITH RECENT TRENDS AND THE RELATIVELY HI AMPLITUDE OF THE WRN
RDG/ERN TROF THAT WOULD A MORE SHARPLY DIGGING SHRTWV. HOWEVER...
OVERALL TREND TOWARD A MORE ZONAL FLOW BY MID WEEK MIGHT SUPPORT THE
FARTHER E TRACK SHOWN BY THE NCEP MODELS. 12Z GFS ENSEMBLE MEMBERS
SHOW SUPPORT FOR BOTH SCENARIOS...BUT A BULK OF THE MEMBERS LINE UP
MORE CLOSELY THE WITH OPERATIONAL NAM/GFS. SINCE THERE IS SUPPORT
FOR BOTH SCENARIOS...WL RELY ON THE MODEL CONSENSUS FOR POPS/QPF
RIGHT NOW. SO WL FCST HIER POPS/SN OVER THE WRN CWA. THE ONLY
CONCERN IS FCST S WIND UP THE LENGTH OF LK MI IN THE PRESENCE OF H85
TEMPS AOB -10C. THIS MAY RESULT IN SOME LK ENHANCEMENT IF THE
DRYNESS/HI STABILITY OF THE ANTECEDENT AIRMASS CAN BE OVERCOME.
TENDED TO BUMP UP POPS A BIT IN THIS AREA. AS THE SHRTWV SLIDES TO
THE SE ON MON NGT AND IS FOLLOWED BY DEEP LYR QVECTOR DVGC/
SUBSIDENCE...EXPECT SLOWLY DIMINISHING POPS IN THE ABSENCE OF
MEANINGFUL CAA THAT WL LIMIT THE POTENTIAL FOR LES. WITH MORE CLD
COVER/SLOW RETREAT OF THE ARCTIC HI TO THE NE...TEMPS WL MODERATE
THRU THIS TIME.

TUE INTO TUE NGT...ALTHOUGH LINGERING LO PRES TROF ASSOCIATED WITH
SHEARING SHRTWV DIGGING TO THE SSE MAY STILL BE THE FOCUS FOR SOME
LIGHT SN... OVERALL LARGER SCALE QVECTOR DVGC ASSOCIATED WITH APRCH
OF TRAILING SHRTWV RDG SHOULD RESULT IN A CONTINUED DIMINISHING
TREND IN POPS. SOME OF THE MODELS SHOW ANOTHER SHRTWV/SFC LO
TRACKING INTO NW ONTARIO AND MOVING FAR ENUF TO THE S TO ALLOW FOR
SOME LARGER SCALE FORCING TO BRUSH THE N HALF OF THE CWA...MAINLY LK
SUP.

EXTENDED...ANOTHER SHRTWV IS FCST TO MOVE ESE FM SCENTRAL CANADA ON
WED INTO THE UPR LKS ON THU IN THE WNW FLOW ALOFT THAT IS FCST TO
DVLP AS THE ERN TROF SLOWLY WEAKENS. NOT SURPRISINGLY...THERE ARE
LARGE DIFFERENCE IN THE FCST MSLP/THERMAL FIELDS. IN GENERAL...THE
MODEL TREND HAS BEEN FOR THE ACCOMPANYING SFC LO TO TRACK FARTHER TO
THE S...PROBABLY BECAUSE THE LONGER RANGE MODELS SHOW A HIER
AMPLITUDE UPR RDG PERSISTING OVER WRN NAMERICA. BEST CHANCE FOR SOME
PCPN WL BE WED NGT INTO THU BEFORE COLDER AIR FOLLOWS LATE IN THE
WEEK.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1158 PM EST FRI JAN 23 2015

MVFR CONDITIONS WILL GENERALLY BE THE RULE THROUGH MUCH OF THE TAF
PERIOD UNDER A W-NW FLOW OF LOW LEVEL MOISTURE. CONDITIONS ARE
EXPECTED TO BE THE WORST AT KIWD WHERE UPSLOPE CONDITIONS COULD LEAD
TO IFR CONDITIONS LATE TONIGHT/EARLY SATURDAY. CONDITIONS SHOULD BE
BEST AT KSAW AS DOWNSLOPE WNW FLOW TONIGHT SHOULD LIMIT FALL IN CIGS.
CONDITIONS AT KSAW WILL DETERIORATE MORE RAPIDLY SAT MORNING AS A
TROUGH MOVES THROUGH...SWITCHING WINDS AROUND TO A MORE NLY
DIRECTION. CONDITIONS SHOULD IMPROVE SLIGHTLY AT KIWD AND KCMX LATE
SATURDAY AS WINDS SHIFT MORE NE BUT STILL SHOULD REMAIN MVFR.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 421 AM EST SAT JAN 24 2015

A LOW OVER N QUEBEC WILL DRIFT E TODAY AND DRAG A TROUGH ACROSS THE
UPPER GREAT LAKES THIS MORNING. THE RESULT WILL BE INCREASING N
WINDS WITH GUSTS NEARING 30KTS LATE THIS MORNING THROUGH THE REST OF
TODAY. EXPECT INCREASING NE WINDS TO FUNNEL OVER W LAKE SUPERIOR
TONIGHT...WITH ANOTHER ROUND OF 25-30KT GUSTS POSSIBLE.

HIGH PRESSURE OVER CENTRAL CANADA TO SHIFT INTO NW ONTARIO ON SUNDAY
MORNING...AND SW QUEBEC ON MONDAY. AT THE SAME TIME A LOW DIVING SE
FROM CENTRAL SASKATCHEWAN THIS MORNING WILL PUSH INTO THE MID MS
VALLEY ON SUNDAY. ANOTHER LOW DEVELOPING IN WEST CENTRAL CANADA ON
SUNDAY WILL CROSS LAKE WINNIPEG MONDAY MORNING...AND WISCONSIN ON
MONDAY EVENING. LOOK FOR A HIGH OVER THE N PLAINS ON TUESDAY TO
SHIFT TO OH RIVER VALLEY ON WEDNESDAY. THIS WILL BE TO THE S OF A
TROUGH THAT WILL DRIFT ACROSS NORTHWEST ONTARIO. ANOTHER LOW WILL
DEVELOP IN THE N PLAINS ON WEDNESDAY.
&&

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

$$

SHORT TERM...TITUS
LONG TERM...KC
AVIATION...VOSS
MARINE...KF



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