Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 231154
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
654 AM EST FRI JAN 23 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM EST FRI JAN 23 2015

A WINTRY MIX OF PRECIPITATION IS IN STORE FOR MUCH OF UPPER MICHIGAN
DURING THE SHORT TERM PERIOD...TIED TO A CLIPPER SYSTEM MOVING
THROUGH NORTHERN ONTARIO. THE 998MB LOW IS CURRENTLY LOCATED IN FAR
NORTHWEST ONTARIO AND MOVING SOUTHEAST. A TIGHT PRESSURE GRADIENT
BETWEEN THE LOW AND ITS ASSOCIATED SURFACE TROUGH AND A HIGH
PRESSURE RIDGE IN THE LOWER GREAT LAKES AND OHIO RIVER VALLEY HAS
LED TO A BREEZY SOUTHWESTERLY WIND OVER LAKE SUPERIOR AND MUCH OF
UPPER MICHIGAN. THE STRONGEST WIND GUST THUS FAR WAS REPORTED AT
ROCK OF AGES AT 5Z WITH A GUST OF 50KTS. OVER UPPER MICHIGAN...GUSTS
HAVE BEEN IN THE 30-35MPH RANGE OVER THE WESTERN HALF AND 20-30MPH
OVER THE EAST. THESE WINDS...ALONG WITH INCREASING CLOUDS...HAVE LED
TO TEMPERATURES BECOMING STEADY OR EVEN SLIGHTLY RISING DURING THE
OVERNIGHT HOURS. OVER THE LAST HOUR...HAVE SEEN THE PRECIPITATION
START TO OCCUR AT KCMX AND THAT WILL CONTINUE SOUTHEAST ACROSS THE
REST OF THE CWA TODAY.

TWO AREAS OF PRECIPITATION ARE ASSOCIATED WITH THIS CLIPPER
SYSTEM...ONE OF WHICH WILL BE TIED TO AN EMBEDDED WAVE WITHIN THE
LARGER SHORTWAVE TROUGH. THE STRONGER OF THE TWO PRECIPITATION AREAS
HAS STARTED TO DROP SOUTHEAST ACROSS CENTRAL/EASTERN LAKE SUPERIOR
THIS MORNING AND WILL CONTINUE ACROSS THE EASTERN 2/3RDS OF THE U.P.
TODAY. THIS PRECIPITATION IS TIED TO THE DEEPER FORCING ON THE 285-
300K SURFACES AND SEPARATED FROM THE STRONGEST PIECE OF SHORTWAVE
ENERGY TRACKING JUST TO THE NORTH OF LAKE SUPERIOR TODAY. THE
HEAVIEST PRECIPITATION WITH THIS FEATURE WILL OCCUR MAINLY EAST OF A
LINE FROM MARQUETTE TO ESCANABA (QPF AMOUNTS OF 0.1-0.25IN)...WHILE
AREAS FARTHER TO THE WEST WILL SEE FEW HUNDREDTHS TO A TENTH OF AN
INCH. A SECOND WAVE OF PRECIPITATION...TIED TO THE SOUTHERN PIECE OF
ENERGY AND NOSE OF STRONG WARM AIR ADVECTION THAT IS CURRENTLY
MOVING THROUGH NORTHERN MINNESOTA AND PRODUCING FREEZING RAIN...WILL
MOVE SOUTHEAST THROUGH NORTHWEST WISCONSIN AND BRUSH THE WESTERN
U.P. NEAR THE WISCONSIN BORDER. OVERALL...BOTH OF THESE FEATURES
WILL QUICKLY SWEEP ACROSS THE AREA...WITH MOST LOCATIONS ONLY SEEING
PRECIPITATION FOR A 3-5HR PERIOD TODAY.

STILL SOME VARIABILITY IN THE STRENGTH OF THE WARM NOSE...BUT HIGH
RESOLUTION MODELS (NAM/RAP/GEM-REGIONAL) ARE IN DECENT AGREEMENT
WITH THE NOSE OF 1-2C AIR BETWEEN 850-800MB MOVING SOUTHEAST ACROSS
THE WESTERN HALF OF UPPER MICHIGAN THIS MORNING THROUGH EARLY
AFTERNOON. THAT SHOULD BE AMPLE TO LEAD TO SOME MELTING OF THE SNOW
FALLING FROM ALOFT AND WILL CONTINUE TO SHOW A WINTRY MIX
(RAIN...SNOW...SLEET...AND FREEZING RAIN) AS THIS AREA OF
PRECIPITATION MOVES THROUGH THE WESTERN/CENTRAL U.P. WITH
TEMPERATURES STARTING OFF IN THE 20S IN MOST LOCATIONS AND MIDOT
ROAD TEMPS IN THE MID-UPPER 20S...ANY LIQUID PRECIPITATION WOULD
FREEZE ON THE SURFACE AND LEAD TO SLICK CONDITIONS ON UNTREATED
ROADS/SIDEWALKS. WITH LIGHT ICING REPORTED UPSTREAM IN
MINNESOTA...AM A LITTLE CONCERNED IN THERE BEING A QUICK 1-2 HOUR
PERIOD OF FREEZING RAIN THAT COULD LEAD TO A BRIEF PERIOD OF
SLIPPERY ROADS THIS MORNING BEFORE THE SYSTEM QUICKLY DEPARTS. BUT
CONFIDENCE WASN/T HIGH ENOUGH FOR A LONG DURATION
IMPACT...ESPECIALLY WITH TEMPERATURES WARMING ABOVE FREEZING QUICKLY
AFTER THE PRECIPITATION OCCURS TO GO WITH AN ADVISORY.
INSTEAD...WILL ISSUE AN SPS TO HIGHLIGHT THE WINTRY MIX AND
POTENTIAL FOR FREEZING RAIN TO PRODUCE SLIPPERY ROADS. MEANWHILE
OVER THE EAST...THE WARM NOSE WON/T MAKE IT FAR ENOUGH TO THE EAST
TO MELT ANY OF THE SNOW. THUS...WITH THE EXPECTED SNOW RATIOS AROUND
10-1 DURING THAT BURST OF SNOW...WOULD EXPECT A VERY QUICK 1-2
INCHES OF SNOW (MAYBE A FEW LOCALLY HIGHER AMOUNTS NEAR NEWBERRY).

BEHIND THE TROUGH...EXPECT A FEW HOUR LULL IN THE PRECIPITATION...AS
THE DEEPER MOISTURE PULLS OUT OF THE AREA AND BEFORE LOW LEVEL
MOISTURE MOVES IN. THAT LOW LEVEL MOISTURE WILL COMBINE WITH
UPSLOPING WEST-NORTHWEST WINDS TO LEAD TO THE DEVELOPMENT OF DRIZZLE
(NEARLY THE ENTIRE CLOUD IS WARMER THAN -8C) OVER THE HIGHER TERRAIN
OF WESTERN UPPER MICHIGAN. EXPECT THAT DRIZZLE...AND FREEZING
DRIZZLE AS TEMPERATURES COOL...TO CONTINUE THROUGH MUCH OF THE NIGHT
ALTHOUGH THE FORCING IS LARGELY TERRAIN DRIVEN. THIS IS DUE TO DELTA-
T VALUES BETWEEN THE SURFACE TROUGH THAT MOVES THROUGH THIS
AFTERNOON AND THE COLD FRONT THAT ARRIVES LATER TONIGHT ONLY BEING
AROUND 6. WITH DEEPER MOISTURE ARRIVING LATE TONIGHT WITH THE COLD
FRONT...EXPECT MORE ICE CRYSTALS TO ENTER THE CLOUDS AND STARTED TO
TRANSITION TOWARDS BETTER OPPORTUNITIES FOR SNOW.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 354 AM EST FRI JAN 23 2015

THE GREAT LKS WL BE DOMINATED BY A NW FLOW ALOFT THRU THE MEDIUM/
EXTENDED RANGE BTWN A MEAN RDG OVER WRN NAMERICA AND A TROF OVER THE
E PORTION OF THE CONTINENT. WHILE THE TROF OVER THE E MAY DEEPEN
THIS WEEKEND INTO EARLY NEXT WEEK...THE GUIDANCE INDICATES THE CORE
OF COLDEST AIR WL REMAIN TO THE NE. THERE ARE SIGNS THE THE WRN
RDG/ERN TROF WL THEN DEAMPLIFY FOR AT LEAST A BRIEF TIME THE MIDDLE
OF NEXT WEEK...ALLOWING FOR A RETURN OF SOME MILDER PACIFIC AIR
BEFORE THE PATTERN REAMPLIFIES LATE IN THE WEEK AND MORE ARCTIC AIR
RETURNS TO THE AREA. NO BIG STORMS LOOK TO IMPACT UPR MI DURING THE
NEXT WEEK...BUT A SERIES OF CLIPPER TYPE SHRTWVS EMBEDDED IN THE NW
FLOW ALF MAY BRING SOME LIGHT PCPN TO AT LEAST PORTIONS OF THE CWA
DURING THIS FCST PERIOD.

SAT...AS A SHRTWV EMBEDDED IN THE NW FLOW ALF DIGS SEWD THRU NW
ONTARIO IN THE WAKE OF LO PRES EXITING THRU NRN QUEBEC...THE 00Z
MODELS ARE IN GOOD AGREEMENT SHOWING A SFC COLD FNT DROPPING THRU
THE UPR LKS ON SAT MRNG...WITH H85 TEMPS FALLING TO ARND -14C OVER
LK SUP BY 00Z SUN. ALTHOUGH SOME DEEP LYR QVECTOR CNVGC IS FCST TO
IMPACT THE AREA...A NEAR ABSENCE OF MSTR INFLOW INDICATES ONLY SCT
SN SHOWERS WL ACCOMPANY THE FROPA...MAINLY NEAR LK SUP. DID INCLUDE
A CHC OF SOME FREEZING DZ IN THE UPSLOPE AREAS NEAR LK SUP EARLY IN
THE DAY WHEN THE RATHER SHALLOW MOIST LYR IS STILL WARMER THAN -10C.
AS THE COLDER AIR ARRIVES IN THE AFTN...OVERWATER INSTABILITY WL
BECOME SUFFICIENT FOR SOME LES.  HOWVER...TENDENCY FOR LLVL FLOW TO
BECOME MORE ACYC UNDER DEEP LYR QVECTOR DVGC/SUBSIDENCE THAT IS FCST
TO LOWER THE INVRN TOWARD H9 LATE IN THE DAY AS WELL SOME FAIRLY
SHARP DIRECTIONAL SHEAR IN THE LLVL VEERING FLOW WL GREATLY LIMIT
THE INTENSITY OF THE PCPN.

SAT NGT/SUN...NEXT CLIPPER TYPE SHRTWV THAT WL BE TOPPING THE WRN
RDG ON SAT IS FCST TO DIG SEWD THRU THE PLAINS AND INTO THE LOWER OH
RIVER VALLEY BY LATE SUN WHILE CNDN HI PRES TENDS TO BUILD INTO NW
ONTARIO. MODELS HAVE TRENDED TOWARD DIGGING THIS DISTURBANCE MORE
SHARPLY...CONSISTENT WITH THE RATHER HI AMPLITUDE WRN RDG...WHICH
HAS ALSO CAUSED SOME DISTURBANCES IN THE RECENT PAST TO DIG MORE
SHARPLY THAN EARLIER ANTICIPATED. IN FACT...THE 00Z GFS/CNDN/ECMWF
MODELS SHOW THE SHRTWV AND SFC/H85 LO TRACKING FAR ENUF TO THE SW
THAT THE BULK OF THE DEEP LYR QVECTOR CNVGC AND PCPN PASS TO THE SW
OF UPR MI...WITH NO MORE THAN A FEW HUNDREDTHS OF AN INCH QPF NEAR
THE WI BORDER LATE SAT NGT/SUN MRNG. THE GFS MOS FCST FOR IRON MTN
SHOWS A 12HR POP ON SAT NGT/SUN UNDER 10 PCT...WITH ONLY A POP NEAR
20 AT IRONWOOD. THE 00Z NAM IS A BIT FARTHER TO THE NE AND GENERATES
UP TO 0.15 INCH NEAR THE BORDER. CONSIDERING THE HI AMPLITUDE
PATTERN...DRY LLVL NE FLOW OUT OF THE HI BLDG INTO NW ONTARIO AND
RECENT TRENDS...WL FOLLOW THE DRIER 00Z GFS/CNDN/ECMWF SCENARIO AND
LOWER PREVIOUS FCST POPS. DID RETAIN SOME SCHC POPS NEAR LK SUP WITH
THE AIRMASS SUFFICIENTLY COLD FOR LES AND AN UPSLOPE NE FLOW. ONCE
THE DISTURBANCE PASSES FARTHER TO THE SE AFTER SUN MRNG AND DEEP LYR
QVECTOR DVGC DVLPS...ENDED POPS COMPLETELY EXCEPT NEAR LK SUP. SAT
NGT/SUN TEMPS WL BE COLDEST OVER THE E CLOSER TO THE CORE OF COLD
AIR/HI PRES CENTER TO THE NE.

SUN NGT...SFC HI PRES MOVING SLOWLY SE THRU NW ONTARIO AND INTO
QUEBEC ON MON WL EXTEND A SFC RDG AXIS INTO UPR MI...RESULTING IN
MAINLY DRY WX. EVEN THOUGH H85 TEMPS WITHIN A FEW DEGREES OF -15C WL
BE COLD ENUF FOR LES...LO INVRN BASE UNDER 3K FT AGL AND ACYC NATURE
OF THE LLVL FLOW WL GREATLY LIMIT THE COVERAGE AND INTENSITY OF ANY
SN SHOWERS. EXPECT THE LOWEST MIN TEMPS NEAR THE LO END OF GUIDANCE
OVER THE E CLOSER TO THE SFC HI/CORE OF DRIER AIR.

MON/MON NGT...THE HI PRES TO THE NE IS FCST TO DRIFT E INTO QUEBEC.
BUT ON MON INT MON NGT...THE 00Z GFS AND ESPECIALLY THE CNDN MODEL
SHOW ANOTHER CLIPPER SHRTWV DROPPING SEWD AND GENERATING SOME LIGHT
SN OVER MUCH OF UPR MI. THE 12Z ECWMF SHOWS A CLIPPER SHRTWV AS
WELL...BUT TRACKS THIS DISTURBANCE FAR ENUF TO THE W THAT MOST OF
THE PCPN MISSES THE U.P. THE DIFFENENCE THE OPS MODEL FCSTS APPEARS
TO BE RELATED TO THE DEGREE TO WHICH THE GIVEN MODEL IS DEAMPLIFYING
THE PATTERN. SINCE THE 12Z ECMWF SHOWS A HIER AMPLITUDE RDG
PERSISTING LONGER...THE SHRTWV IS FCST TO DIG FARTHER TO THE SW. THE
CNDN MODEL ON THE OTHER HAND HINTS AT A FASTER TREND TOWARD
DEAMPLIFICATION...THUS ALLOWING THE SHRTWV/DYNAMIC FORCING TO MOVE
FARTHER TO THE E. SINCE THE 00Z ECWMF HAS TENDED TO SHIFT THE
CLIPPER TRACK TO THE E...FOLLOWED THE MODEL CONSENSUS FOR POPS.

EXTENDED...ALTHOUGH HGTS ARE FCST TO RISE ON TUE AS THE TROF IN ERN
CANADA SLOWLY WEAKENS...LINGERING LO PRES TROF EXTENDING S FM LO
PRES MOVING THRU HUDSON BAY WILL SERVE AS A FOCUS FOR SOME LO CHCS
POPS ON TUE. AS THE FLOW ALF TRENDS MORE ZONAL ON WED...ANOTHER
SHRTWV/SFC LO PRES WL TRACK THRU NW ONTARIO AND BRING SOME CHC POPS
ACROSS MAINLY THE NRN PART OF THE CWA. INFLUX OF SOME MILDER PACIFIC
AIR IN THE WSW FLOW ON THE SRN FLANK OF THIS CLIPPER WL LIFT H85
TEMPS TOWARD 0C ON WED. BUT COLDER AIR/LES CHANCES WL FOLLOW AN
EARLY THU FROPA. THE 00Z ECMWF/GFS HINT H85 TEMPS WL FALL TOWARD -
28C BY LATE NEXT WEEKEND AS THE ERN TROF DEEPENS...SO JAN SHOULD END
ON A COLD NOTE.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 653 AM EST FRI JAN 23 2015

A CLIPPER SYSTEM SLIDING ACROSS FAR NORTHERN ONTARIO WILL DRAG A
TROUGH ACROSS UPPER MICHIGAN THIS MORNING AND EARLY AFTERNOON. WARM
AIR SURGING OVER THE AREA AHEAD OF THIS TROUGH WILL LEAD TO A MIX
OF FREEZING RAIN...SNOW...AND SLEET THIS MORNING. THINK THERE IS
ENOUGH LOW LEVEL DRY AIR TO KEEP CEILINGS IN THE VFR RANGE FOR MUCH
OF THE MORNING...ALTHOUGH THERE MAY BE A BRIEF PERIOD WHERE
KIWD/KCMX FALL TO MVFR BEFORE THE PRECIPITATION ENDS.

BEHIND THE TROUGH...EXPECT VFR CONDITIONS TO CONTINUE THROUGH MID
AFTERNOON BEFORE ABUNDANT LOW LEVEL MOISTURE SLIDES INTO THE AREA.
THIS WILL LEAD TO CEILINGS FALLING TO IFR THIS EVENING AT KIWD/KCMX
WITH DZ/FZDZ. THOSE IFR CEILINGS WILL CONTINUE THROUGH MUCH OF THE
REST OF THE TAF PERIOD. AT KSAW...THE WEST-NORTHWEST WINDS WILL
LEAD TO DOWNSLOPING AND HAVE KEPT CEILINGS IN THE MVFR RANGE.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 AM EST FRI JAN 23 2015

A 998MB LOW MOVING SOUTHEAST ACROSS FAR NORTHERN ONTARIO THIS
MORNING WILL SWEEP A TROUGH ACROSS LAKE SUPERIOR LATE THIS MORNING
AND THIS AFTERNOON. AHEAD OF THE TROUGH...GUSTY SOUTHWESTERLY WINDS
ARE IN PLACE OVER WESTERN AND CENTRAL LAKE SUPERIOR...WITH GUSTS IN
THE 35-45KT RANGE. THERE WAS EVEN A GUST LATE YESTERDAY EVENING AT
ROCK OF AGES THAT REACHED 50KTS. THESE GALES WILL CONTINUE THROUGH
AROUND MID MORNING...BEFORE SHIFTING TO THE WEST THIS AFTERNOON AT
15-25KTS. DID EXTEND THE GALE WARNING FOR A COUPLE HOURS TO ACCOUNT
FOR A SLIGHTLY SLOWER DIMINISHING TREND THIS MORNING. THESE WESTERLY
WINDS WILL STAY BELOW 25KTS FOR MUCH OF TONIGHT BEFORE A TRAILING
COLD FRONT DROPS SOUTHEAST ACROSS LAKE SUPERIOR LATE TONIGHT AND
SATURDAY MORNING...WHICH WILL SHIFT WINDS TO THE NORTH AT 20-30KTS.
A HIGH PRESSURE RIDGE WILL THEN QUICKLY NOSE SOUTHEAST INTO UPPER
MICHIGAN SATURDAY EVENING AND DIMINISH THE WINDS WHILE VEERING THEM
TO THE NORTHEAST. ANOTHER CLIPPER SYSTEM WILL MOVE OUT OF CANADA AND
THROUGH THE UPPER MISSISSIPPI VALLEY ON SATURDAY NIGHT AND THEN
SLIDE THROUGH WISCONSIN SUNDAY MORNING. THIS WILL KEEP WINDS UP TO
20KTS OUT OF THE NORTH-NORTHEAST. ANOTHER RIDGE WILL BUILD IN BEHIND
THIS CLIPPER AND KEEP WINDS 20KTS OR BELOW SUNDAY NIGHT INTO MONDAY.
SOUTHERLY FLOW WILL BEGIN TO INCREASE MONDAY NIGHT INTO TUESDAY
AHEAD OF THE NEXT CLIPPER SYSTEM TAKING SHAPE IN
ALBERTA/SASKATCHEWAN.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
  GALE WARNING UNTIL NOON EST /11 AM CST/ TODAY FOR LSZ162-263-264-
     266.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...SRF
LONG TERM...KC
AVIATION...SRF
MARINE...SRF



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