Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KMQT 271151
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
651 AM EST THU NOV 27 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 556 AM EST THU NOV 27 2014

WATER VAPOR IMAGERY AND RUC ANALYSIS REVEAL AN AMPLIFIED PATTERN
ACROSS NAMERICA WITH A RIDGE OVER THE W COAST AND A TROF EXTENDING
FROM NCNTRL CANADA INTO THE ERN CONUS. A SHORTWAVE TROF MOVING
ACROSS THE REGION IS PRODUCING SOME -SN OVER NCNTRL WI AND PERHAPS
PROVIDING SOME ENHANCEMENT TO LES OVER ERN LAKE SUPERIOR INTO THE
THE ERN HALF OF UPPER MI. COLD AND VERY DRY AIR MASS UPSTREAM AS
NOTED ON 00Z KINL SNDG AND MINUS TEENS TO MINUS 20S DEWPOINTS OVER
WRN ONTARIO AND NRN MN WILL NEGATIVELY IMPACT LES FROM WEST TO EAST
TODAY AS IT MOVES ACROSS LAKE SUPERIOR IN THE WAKE OF THE SHORTWAVE
PASSAGE.

TODAY...MODEL SNDGS SHOW SHARP LOWERING OF INVERSION BASES BLO 4KFT
AS Q-VECT DIV SPREADING FROM WEST TO EAST ACROSS THE FCST AREA TODAY
AHEAD OF ADVANCING SHORTWAVE RIDGE. LOW-LEVEL FLOW ALSO BCMS MORE
ANTICYCLONIC THROUGH THE DAY WHICH IN TURN WILL WEAKEN LOW-LVL
CONVERGENCE. ALL THESE FACTORS WILL COMBINE TO QUICKLY DIMINISH LES
FROM W TO E THRU THE DAY. IN FACT OVER THE FAR W...EXPECT LES TO END
LATE IN THE AFTN AROUND KIWD AS FLOW BACKS SW. THE ONE POSITIVE
FACTOR FOR THE LES S THAT THE DGZ IS FIRMLY SITUATED THROUGH THE
CONVECTIVE LAYER ALLOWING FOR FLUFFY SNOW ACCUMULATIONS.
SO...DESPITE THE NEGATIVES LEADING TO MOSTLY LIGHT LES ON THE
WHOLE...MIGHT BE ABLE TO STILL GET 3-4 INCHES OF ADDITIONAL SNOW
WHERE LES IS MOST PERSISTENT. THE GREATEST ACCUMULATIONS WILL OCCUR
E OF MARQUETTE WHERE LOW-LEVEL FLOW IS MORE CYCLONIC THRU THE EARLY
PART OF THE DAY AND WHERE NW FETCH MAY BE HELPED BY LAKE NIPIGON
PRECONDITIONING. AWAY FROM THE MAIN LES...SCT -SHSN/FLURRIES ARE
POSSIBLE AT TIMES...EXCEPT OVER THE FAR SCNTRL. TEMPS WILL BE
UNSEASONABLY COLD TODAY AS 850MB THERMAL TROF (AROUND -20C) PASSES
ACROSS THE AREA. EXPECT HIGHS RANGING FM 10 TO 15F OVER THE WEST
HALF...TO AROUND 20F ALONG LAKE SUPERIOR AND E. RECORD LOW MAX
TEMP OF 18F HERE AT NWS MQT WILL FALL. IF TEMP DOESN`T REACH
14F...IT WILL BE THE COLDEST MAX TEMP FOR SO EARLY IN THE SEASON.

TONIGHT...THE LINGERING LES WILL DIMINISH OVER THE KEWEENAW AND FAR
ERN SHORELINE PORTION OF CWA AS THE SFC RIDGE AXIS SLIDES THROUGH
THE AREA ALLOWING THE LOW LEVEL WINDS TO BACK SW. WITH LIGHT
WINDS AND A PERIOD OF CLEARING OVER THE INTERIOR WEST DURING THE
EVENING...TEMPS WILL DROP QUICKLY TO MINS ON THE LOWER END OF MODEL
GUIDANCE BEFORE RECOVERING OVERNIGHT AS CLOUDS MOVE IN. MODELS
TRENDING A BIT SLOWER WITH ARRIVAL OF LIGHT SNOW INTO THE WEST LATE
WITH THE DEVELOPING WAA PATTERN...SO HAVE TRIMMED BACK POPS TO
SLIGHT CHC.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 509 AM EST THU NOV 27 2014

TROUGHING BRINGING THE WELL BLO NORMAL TEMPERATURES ACROSS THE AREA
TODAY EXITS OVER EASTERN CANADA AND NEW ENGLAND ON FRIDAY. UPPER
LEVEL FLOW BECOMES MORE PROGRESSIVE FROM THE PACIFIC NW ACROSS THE
NORTHERN PLAINS AND OVER THE GREAT LAKES REGION. SHORTWAVE TROUGH
CURRENTLY JUST OFFSHORE OF PACIFIC NW HEADS EAST AND WILL SUPPORT
AREA OF WARM ADVECTION/ISENTROPIC ASCENT ALONG TIGHT BAROCLINIC ZONE
SFC-H85. MODELS STILL DIFFER ON WHERE SHARPEST TEMPERATURE GRADIENT
SETS UP...BUT SEEMS THAT AT LEAST THE SOUTH HALF OF UPR MICHIGAN
SEES WIDESPREAD SNOW...WITH A BIT MORE QUESTION ON NORTHERN EXTENT.
IF BAND OF MORE CONCENTRATED SNOW SLIDES NORTHWARD THEN COULD SEE
AMOUNTS NEARING ADVY ALONG THE WI BORDER AND NEAR BAY OF GREEN BAY
FRIDAY AFTN INTO FRIDAY EVENING. PRIMARY AREA OF CONCERN STILL IS OVER
EASTERN CWA THOUGH...SCHOOLCRAFT AND LUCE COUNTIES...DUE TO LAKE
ENHANCEMENT OFF LK MICHIGAN AS THE LARGER SCALE MOISTURE AND FORCING
WITH THE SHORTWAVE COMBINES WITH MEAN BLRY SSW FLOW AND H85 TEMPS
LOWER THAN -10C...PLENTY LOW ENOUGH FOR LAKE ENHANCEMENT WITH LK
MICHIGAN WATER TEMPS AROUND UP TO 4C. IF THE FARTHER NORTH NAM IDEA
IS CORRECT WITH MORE DIRECT INFLUENCE FROM THE INCOMING SYSTEM...THEN
MODERATE TO HEAVY SNOW WOULD OCCUR. BLEND OF OTHER MODELS...INCLUDING
THE FAVORED ECMWF/GEM-NH...POINT TO SOLID ADVY AMOUNTS. WILL MENTION
IN THE HWO AND HIGHLIGHT IN EHWO GRAPHICS...BUT NOT ISSUE ANY WATCH
ATTM GIVEN THE UNCERTAINTY ON TRACK OF INCOMING SYSTEM.

MESSY FORECAST LATER FRIDAY NIGHT INTO SATURDAY. OR MAYBE IT WILL
JUST END UP BENIGN. STILL TRYING TO FIGURE THIS OUT...BUT ECMWF/GEM
AND TREND FROM GFS WOULD SUGGEST MORE DRIER IDEA. ECMWF AND GEM ARE
FARTHER NORTH WITH LARGER SCALE Q-VECTOR CONVERGENCE AND DEEP
MOISTURE TIED INTO THE NEXT SHORTWAVE/SFC LOW MOVING ACROSS IN WHAT
LOOKS MORE LIKE A ZONAL FLOW PATTERN. H85 TEMPS QUITE WARM OFF THE
ECMWF WITH +8C...YES PLUS 8...INTO SCNTRL UPR MICHIGAN BY 00Z
SUNDAY. GEM EVEN WARMER AND THE NAM/GFS IN THE BALLPARK AS WELL.
EVEN WITH THE WARMTH...SOUNDINGS FM THE NAM/GFS SUGGEST THE ONLY
KIND OF PRECIP OCCURRING...IF ANY...WOULD BE DRIZZLE AS ONLY MOISTURE
IS BLO H85 WITH DRY AIR ALOFT. EXCEPTION TO THIS WOULD BE OVER THE
NORTH AND EAST CWA SATURDAY MORNING AND THEN RETURNING TO THE
NORTHWEST CWA LATER SATURDAY NIGHT ONCE THE SFC LOW PASSES BY AND A
COLD FRONT RE-ENTERS THE PICTURE. HAVE TRENDED TOWARD THE DZ/FZDZ
IDEA FOR LATE FRIDAY NIGHT THROUGH SATURDAY. NOW IF THIS FORECAST OF
LOW LEVEL MOISTURE TRAPPED BENEATH THE WARM AIR ADVECTION ALOFT TURNS
OUT TO BE OVERDONE AS HAS OCCURRED IN THE PAST...THEN SATURDAY COULD
ACTUALLY END UP BEING AN NICE DAY WITH PARTLY SUNNY SKIES AND ABOVE
NORMAL TEMPS. MIXING TO H9 VALUES OFF THE GFS WOULD YIELD LOW 40S
OVER PARTS OF THE AREA. FOR NOW...KEPT WITH THE LOW CLOUD/DZ IDEA AND
HAVE HIGHS IN THE MID 30S.

ONCE THE COLD FRONT ARRIVES LATER SATURDAY NIGHT...PRETTY QUICK DROP
OFF IN TEMPS AT H85. ECMWF SLOWER THAN THE GFS AND PROBABLY IS MORE
ON TRACK GIVEN THE FARTHER NORTH TREND OF WARMER AIR TO START THE
WEEKEND. EVEN SO...ENOUGH COLD AIR BY SUNDAY AFTN TO START THE LAKE
EFFECT UP AGAIN FOR AREAS FAVORED BY NORTHWEST WINDS. SHORTWAVE MOVING
THROUGH SUNDAY INTO MONDAY COULD RESULT IN A PERIOD OR TWO OF LAKE
ENHANCEMENT. CORE OF COLDEST AIR ARRIVES ON MONDAY. H85 TEMPS A VERY
CHILLY -20C TO -24C...COLDEST ON THE GFS. AT LEAST LIGHT LES SHOULD
CONTINUE NEAR LK SUPERIOR AND EAST. CENTER OF HIGH PRESSURE RIDGE IS
MORE OVER THE PLAINS...SO PRESSURE GRADIENT WILL BE FAIRLY TIGHT
LEADING TO SOME LOWER WIND CHILLS ON MONDAY MORNING.

ONCE THE HIGH MOVES TOWARD THE LOWER GREAT LAKES ON TUESDAY...TEMPS
MODERATE IN WARM AIR ADVECTION ON THE BACK SIDE OF THE HIGH. COULD
BE SOME SNOW BREAK OUT OVER REGION DUE TO THE WARM AND MOIST ADVECTION.
BEST CHANCE OF THAT LOOKS TO BE NEXT TUESDAY.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 645 AM EST THU NOV 27 2014

WITH INCREASING SUBSIDENCE/DRY ADVECTION IN ADVANCE OF HI PRES
MOVING E FM THE NRN PLAINS...EXPECT GRADUALLY IMPROVING CONDITIONS
TODAY AT TAF SITES. WITH THE MOST FAVORABLE UPSLOPE/CONFLUENT N
WIND...IWD WL SEE A LONGER PERSISTENCE OF SHSN/IFR VSBYS THIS MORNING.
AS THE HI AND ACCOMPANYING DRIER AIR EDGE CLOSER...THE LLVL WINDS WL
BACK TOWARD THE WNW EARLY THIS AFTN AND THEN TO THE WSW THIS EVNG...
RESULTING IN A RETURN TO VFR CONDITIONS AT IWD. MORE UPSLOPE WRLY WIND
AT CMX BY THIS AFTERNOON MAY HOLD CIGS IN THE MVFR RANGE AT THAT
LOCATION THRU THE MUCH OF THIS EVENING. NW WINDS BACKING TO S-SW
TONIGHT AT KSAW SHOULD CONTINUE THE VFR CONDITIONS THERE THRU THE
PERIOD. &&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 556 AM EST THU NOV 27 2014

NW WINDS TO 25 KNOTS WILL DIMINISH TO UNDER 20 KT W TO E TODAY INTO
TONIGHT AS HIGH PRES RIDGE ARRIVES. WITH ANOTHER COLD FRONT
PUSHING ACROSS THE UPPER LAKES SAT NIGHT...EXPECT INCREASING S/SW
WINDS TO 15-25KT FRI BEHIND THE FRONT...NW WINDS MAY REACH 20-30KT
LATE SAT NIGHT AND SUN AND INCREASE TO GALES BY SUN NIGHT INTO MON.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
     MIZ006.

LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...VOSS
MARINE...VOSS






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.