Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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 251743
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1243 PM EST THU DEC 25 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 AM EST THU DEC 25 2014

PLEASANT FLYING WEATHER FOR THE BIG GUY EARLY THIS MORNING...WITH
JUST LIGHT SNOW...OR DRIZZLE/FREEZING DRIZZLE OUT THERE. EVEN HAD
SOME POCKETS OF SCT CLOUD COVER DEVELOP 06-08Z FROM ISLE ROYALE
THROUGH PORTIONS OF THE KEWEENAW PENINSULA...AND DOWN THROUGH
CENTRAL UPPER MI. LOOKS LIKE THE BEST AREA FOR THIS CLEARING TO
REMAIN WILL BE DOWNWIND OF THE KEWEENAW PENINSULA THROUGH JUST
OFFSHORE OF MARQUETTE AND ALGER COUNTIES. TAKING A LOOK AT THE
LATEST IR SATELLITE IMAGERY...PLENTY OF HIGH END IFR TO LOW END MVFR
CEILINGS REMAIN ACROSS MN AND WI.

LIGHT BROKEN BANDS OF SNOW ON NW WINDS CONTINUE THIS MORNING. AS THE
SFC LOW ALONG THE S ONTARIO/QUEBEC BORDER SHIFTS NNE TODAY...AND A
BRIEF RIDGE BUILDS IN FROM THE SW...EXPECT IMPROVING CONDITIONS
PRECIP WISE. THE CLOUD COVER PREVIOUSLY NOTED DOWN STEAM WILL BE ONE
OF THE TRICKY POINTS OF THIS FCST. EXPECT SOME SPORADIC CLEARING
DURING THE DAY...WITH CLOUDS QUICKLY FILLING BACK IN FROM THE SW.

FOR TONIGHT...THE TROUGH EXTENDING FROM W MANITOBA THROUGH THE
STRONGER E CO LOW THIS MORNING WILL SLIDE OVER THE W HALF OF UPPER
MI/LAKE SUPERIOR BY 06Z...AND CENTRAL AREAS BY 12Z. LOOK FOR LIGHT
SNOW TO OVERSPREAD THE CWA THROUGH THE EVENING HOURS...AND
LIFT/CENTER ACROSS THE FAR W LATE TONIGHT IN RESPONSE TO THE
ELONGATED SHORTWAVE PUSHING N ACROSS THE CWA /PLUS 06Z E KS SFC LOW
SHIFTING N/. EXPECT ALL SNOW TONIGHT...WITH ONLY LIGHT ACCUMULATIONS
GENERALLY LESS THAN 1IN AS SNOW RATIOS AVG 10:1.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 427 AM EST THU DEC 25 2014

LONGER RANGE MODELS INDICATE A SPLIT FLOW PATTERN WILL DOMINATE
NAMERICA INTO EARLY NEXT WEEK WITH AN UPR TROF IN BOTH BRANCHES
CENTERED OVER THE PLAINS. SINCE THE MODELS INDICATE THERE WL NO
PHASING BTWN THE SRN AND NRN BRANCH FLOWS...LOOKS LIKE THERE WL BE
NO MAJOR WINTER STORMS FOR UPR MI DURING THIS TIME. INITIAL FCST
CONCERN WL BE ON POTENTIAL FOR SOME WIDESPREAD LIGHT SN MAINLY LATE
ON FRI NGT INTO SAT IN ADVANCE OF A SRN BRANCH SHRTWV LIFTING NEWD
INTO THE GREAT LKS. FOCUS THEN SHIFTS ON INFLUX OF COLDER AIR AND
THE POTENTIAL FOR LES AS THE NRN BRANCH FLOW BECOMES THE DOMINANT
INFLUENCE OVER THE UPR LKS. ABOVE NORMAL TEMPS INTO SAT WL TREND BLO
NORMAL EARLY NEXT WEEK AS MANY OF THE LONGER RANGE MODELS SHOW H85
TEMPS FALLING AT LEAST NEAR -20C NEXT TUE.

FRI...A STATIONARY FNT UNDER THE SW FLOW ALOFT IN THE CONFLUENCE ZN
BTWN THE NRN AND SRN BRANCH FLOWS WL BE THE FOCUS FOR SOME LIGHT SN
OVER MAINLY THE NW HALF OF THE CWA INTO EARLY AFTN...WHERE AND WHEN
THE MODELS SHOW A PERIOD WHERE A POCKET OF SOME DEEP LYR QVECTOR
CNVGC WL BE IN PLACE OVER AXIS OF HIER MID LVL RH ASSOCIATED WITH
THE WAA PCPN CHCS ON THU NGT. A WEAK COLD FNT ASSOCIATED WITH A NRN
BRANCH SHRTWV MOVING ACROSS ONTARIO WL ALSO PUSH W TO E ACRS THE CWA
DURING THE DAY AND PUSH THE STNRY FNT TO THE E. DEEP LYR QVECTOR
DVGC ARRIVING IN THE WAKE OF THE ONTARIO DISTURBNANCE/SFC COLD FROPA
WL TEND TO DIMINISH PCPN CHCS LATER IN THE DAY. SINCE H85 TEMPS ARE
PROGGED TO FALL TO ONLY -9C TO -10C OVER THE FAR W TOWARD 00Z SAT
AND THE H925 NNW FLOW BEHIND THE FROPA IS FCST TO BE NEUTRAL TO
SLIGHTLY ACYC...EXPECT ONLY LO CHC POPS FOR LES EVEN IN THE FAVORED
SN BELTS.

FRI NGT/SAT...A STRONGER SHRTWV EMERGING OUT OF THE SRN BRANCH TROF
IN THE SCENTRAL PLAINS IS FCST TO MOVE NE TOWARD THE WESTERN GREAT
LKS ON FRI NGT...CAUSING THE DEPARTING SFC FNT TO STALL NOT TOO FAR
SE OF UPR MI. ALTHOUGH A WEAK LO PRES IS FCST TO ACCOMPANY THE
SHRTWV TO THE NE AND RIDE ALONG THE STNRY FNT...THE TRACK OF THE
SHRTWV THRU THE CONFLUENCE ZN BTWN THE SEPARATE BRANCHES SHOULD
CAUSE THIS DISTURBANCE TO SHEAR OUT/WEAKEN WITH TIME. THE 00Z CNDN
MODEL SHOWS THE MOST VIGOROUS SHRTWV/DYNAMIC SUPPORT...WITH SOME
MODERATE PCPN FALLING OVER MAINLY THE SCENTRAL ON SAT MRNG. BUT THIS
MODEL HAS SHOWN VERY POOR RUN-TO-RUN CONTINUITY. IN FACT...PAST RUNS
SHOWED THE MOST SHEARED OUT/WEAKER/DRIER SCENARIO. ALTHOUGH THE 00Z
ECMWF HAS TRENDED IN THIS DIRECTION AS WELL...OPTED TO FOLLOW THE
WEAKER 00Z NAM/12Z ECMWF SOLUTIONS. THE QPF FM THESE MODELS IS ABOUT
0.15 INCH OVER THE SCENTRAL CWA LATE FRI NGT INTO SAT AFTN...
CONSISTENT WITH H7 SPECIFIC HUMIDITY NEAR 2 G/KG. SINCE THE NAM FCST
SDNGS SHOW SOME SHARP UVV WITHIN AN EXPANDING DGZ...THERE COULD BE
2-3 INCHES OF SN IN SOME LOCATIONS IN THAT AREA. OPTED TO BUMP UP
POPS INTO THE LIKELY RANGE OVER ABOUT THE SE HALF OF THE CWA WHERE
THE MSTR IS DEEPEST AND AN AXIS OF H85-7 FGEN PASSES ON SAT MRNG.
THE ARRIVAL OF DEEP LYR QVECTOR DVGC IN THE WAKE OF THE DEPARTING
SHRTWV LATER IN THE DAY WL CAUSE THE SYNOPTIC SCALE SN TO DIMINISH
W-E. ARRIVAL OF H85 TEMPS AS LO AS -12 TO -13C TOWARD 00Z SUN IN THE
WNW FLOW LEFT IN THE WAKE OF THE DEPARTING SHRTWV WL BRING A RETURN
OF MORE LES.

SAT NGT/SUN...LARGER SCALE DNVA/DEEP LYR QVECTOR DVGC IN THE WAKE OF
THE DEPARTING SHRTWV WL DOMINATE MOST OF SAT NGT...BUT THE MEDIUM
RANGE MODELS SHOW A NRN BRANCH SHRTWV ARRIVING LATE SAT NGT AND SUN
WITH SOME DEEP LYR QVECTOR CNVGC/DEEPER MSTR. THIS SETUP COULD
SUPPORT SOME LK ENHANCED SN OVER THE NRN TIER COUNTIES...ESPECIALLY
ALONG LK INDUCED TROF AND WHERE THE LLVL NW FLOW IS MOST FAVORABLE.
GFS FCST SDNGS INDICATE FAVORABLE UVV PROFILE WITHIN A FAIRLY DEEP
DGZ AS WELL.

SUN NGT THRU WED...LONGER RANGE 00Z MODELS SHOW COLDER CANADIAN AIR
STEADILY SURGING INTO THE AREA IN THE NNW FLOW E OF ARCTIC HI PRES
BLDG FM WRN CANADA INTO THE NRN PLAINS. MOST OF THE GUIDANCE SHOWS
THE H85 TEMP FALLING TO AROUND -20C BY 00Z TUE...SO TEMPS WL FALL
BLO NORMAL. THIS SETUP IS A FVRBL ONE FOR LES. ALTHOUGH THE GFS FCST
SNDGS SHOW THE INVRN SINKING AS LO AS 4K FT AGL DURING THIS TIME
FOLLOWING THE DEPARTURE OF THE SHRTWV SUN NGT...OPTED TO BUMP POPS
ABOVE THE CONENSUS FCST INTO THE LIKELY RANGE IN AREAS FAVORED BY
THE EXPECTED LLVL WINDS. AS ANOTHER SHRTWV APRCHS TOWARD NEXT WED...
THE LLVL FLOW MAY BACK SUFFICIENTLY TO SHIFT THE LES OVER MAINLY THE
KEWEENAW AND THE OPEN WATERS OF LK SUP AT THAT TIME.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1242 PM EST THU DEC 25 2014

MOIST SOUTHWESTERLY FLOW BETWEEN A DEPARTING RIDGE AND A TROUGH
LOCATED IN MINNESOTA CONTINUES TO LEAD TO MVFR CEILINGS AT THE TAF
SITES. THERE HAVE BEEN TIMES WHERE THE SOUTHWESTERLY DOWNSLOPE FLOW
AT KIWD/KSAW LED TO THE LOW CLOUDS SCATTERING OUT. BELIEVE THAT
BETTER MOISTURE ARRIVING AT KIWD WILL KEEP THEM IN MVFR CONDITIONS
FOR THE REST OF THE AFTERNOON. CONFIDENCE IS LOWER AT KSAW BASED
OFF THE EDGE OF THE CLOUDS BEING LOCATED JUST TO THE NORTHEAST OF
THE SITE. IN ADDITION...KIMT UPSTREAM DID HAVE CEILINGS RISE TO
VFR OVER THE LAST COUPLE HOURS AND COULD BE AN INDICATION OF A
BRIEF PERIOD OF VFR. OPTED TO GO WITH LOW END MVFR FOR NOW AND
TREND TOWARDS HIGHER MVFR LATER THIS AFTERNOON...BUT WOULD NOT BE
SURPRISED IF THERE ARE A FEW PERIODS OF VFR.

FOR TONIGHT...A COUPLE WEAK DISTURBANCES WILL SHIFT NORTHEAST
THROUGH UPPER MICHIGAN. THE FIRST WAVE WILL LARGELY AFFECT CENTRAL
UPPER MICHIGAN AND HAVE SHOWN A PERIOD OF MVFR VISIBILITIES AS THE
SNOW MOVES THROUGH KSAW. AS THE SECOND WAVE ARRIVES OVERNIGHT...THE
BETTER SNOWFALL WILL SHIFT TO THE NORTHWEST AND AFFECT KCMX/KIWD.
EXPECT VISIBILITIES TO LARGELY STAY MVFR...BUT DID BRING KIWD DOWN
TO IFR FOR A PERIOD LATE TONIGHT INTO FRIDAY MORNING AS WINDS SHIFT
TO THE NORTH AND LAKE ENHANCEMENT INCREASES THE SNOWFALL INTENSITY.
THIS SNOW WILL SHIFT OUT OF THE WESTERN U.P. DURING THE AFTERNOON
ON FRIDAY.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 AM EST THU DEC 25 2014

A FEW NW GUSTS NEARING 30KTS WILL BE POSSIBLE EARLY THIS MORNING
OVER E LAKE SUPERIOR. A LOW MOVING INTO SW QUEBEC THIS MORNING WILL
CONTINUE TO EXIT THE AREA AS A RIDGE AXIS EXTENDING N OF A HIGH
PRESSURE CENTER OVER THE SE STATES CROSSES THE UPPER GREAT LAKES. AS
THIS RIDGE SHIFTS OVER SE CANADA TONIGHT AND NEW ENGLAND ON
FRIDAY...A WEAK TROUGH WILL MOVE ACROSS LAKE SUPERIOR. THIS TROUGH
WILL STALL OVER THE GREAT LAKES ON FRIDAY NIGHT...ALLOWING A WEAK
LOW TO MOVE FROM THE UPPER MIDWEST THROUGH LOWER MICHIGAN AND INTO
SE ONTARIO ON SATURDAY. AS A HIGH PRESSURE BUILDS INTO W CANADA AND
ANOTHER HIGH MOVES FROM THE PLAINS TOWARD THE OHIO RIVER VALLEY ON
SUNDAY...EXPECT A WEAK TROUGH AVERAGING TO DROP SOUTH THROUGH THE
UPPER GREAT LAKES. THE HIGH IN WESTERN CANADA WILL MOVE INTO THE
NORTHERN PLAINS ON MONDAY. WITH HIGH PRESSURE WILL COME LIGHTER
WINDS...BUT ALSO COOLER AIR...INCREASING THE POTENTIAL FOR FREEZING
SPRAY FROM LATE SUNDAY ON.
&&

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

$$

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






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