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 230855
AFDMQT

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

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 350 PM EST THU JAN 22 2015

SKIES CLEARED OUT QUICKLY TODAY AHEAD OF CLIPPER SYSTEM OVER
SASKATCHEWAN. THE CLIPPER WILL MOVE INTO FAR NWRN ONTARIO AT 06Z FRI
AND THEN CROSS NERN LAKE SUPERIOR BETWEEN 12Z AND 00Z FRI. SYSTEM IS
COMPLICATED AS TEMPERATURES AND DGZ MOISTURE WILL MAKE FOR MIXED
PRECIP AT TIMES...ESPECIALLY BEHIND THE SYSTEM WITH UPSLOPE W-NW LOW
LEVEL FLOW.

MOST HIGH RES MODELS AGREE IN KEEPING THE BEST QPF OVER THE NERN
CWA...MAINLY ERN LAKE SUPERIOR AND ERN UPPER MI...BUT THE NCEP HIGH
RES WRF RUNS KEEP THE BEST QPF NE OF ERN UPPER MI. BLEND OF THE HIGH
RES MODELS SUGGESTS UP TO 0.15 INCHES OVER ERN UPPER MI...WHICH
SHOULD FALL MOSTLY AS SNOW...RESULTING IN LESS THAN 1.5 INCHES OF
SNOW IN THAT AREA GIVEN POOR SNOW TO LIQUID RATIOS.

ELSEWHERE...PRECIP SHOULD START AS SNOW BEFORE WARMING AIR COMES IN
AND TRANSITIONS PRECIP TO A WINTRY MIX OR ALL RAIN/FREEZING RAIN.
THE MIXED PRECIP SHOULD LAST LONG AS DRY MID LEVEL AIR MOVES IN
QUICKLY LATE TONIGHT AND EARLY FRI...DRYING THE DGZ OUT. THE W-NW
LOW LEVEL WINDS WILL THEN LEAD TO DRIZZLE/FREEZING DRIZZLE IN
UPSLOPE AREAS ON FRI. EXPECT ICE ACCUMULATIONS TO BE MINIMAL AS MOST
LOCATIONS WARM TO JUST ABOVE FREEZING ON FRI AND WINDS WILL BE GUSTY
ENOUGH TO HELP REDUCE ICE ACCUMULATIONS.

.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 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1150 PM EST THU JAN 22 2015

MVFR AND SOME IFR CIGS PRESENT TO THE SW IN WI HAVE BEEN MAKING SOME
PROGRESS NE DURING THE EVENING. SO...IT APPEARS KIWD AND
PARTICULARLY KSAW WILL PROBABLY HAVE A PERIOD OF LOW MVFR CIGS
OVERNIGHT. AT KCMX...VFR CONDITIONS WILL CONTINUE. OTHERWISE...LOW-
LEVEL JET HAS TRANSLATED INTO THE AREA IN RESPONSE TO LOW PRES
TRACKING ESE TOWARD NRN ONTARIO. THIS WILL CONTINUE TO RESULT IN
LLWS WHERE INVERSION ALLOWS SFC WINDS TO REMAIN MORE DECOUPLED. A
PERIOD OF A WINTRY MIX OF LIGHT PCPN IS THEN EXPECTED LATE IN THE
NIGHT AND THIS MORNING. VIS WILL PROBABLY REMAIN VFR AS THE PCPN
SHOULD BE QUITE LIGHT. BY THE TIME PCPN ENDS LATE MORNING...CIGS
WILL LIKELY BE MVFR AT ALL TERMINALS. FURTHER REDUCTION TO IFR
SHOULD OCCUR AT KIWD/KCMX IN THE AFTN UNDER DEVELOPING UPSLOPE
WESTERLY FLOW...AND THERE COULD BE SOME -DZ/-FZDZ AS WELL.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 350 PM EST THU JAN 22 2015

AS THE PRESSURE GRADIENT TIGHTENS THIS AFTERNOON AND TONIGHT AHEAD
OF A LOW PRESSURE SYSTEM MOVING THROUGH NORTHERN MANITOBA AND
NORTHERN ONTARIO...EXPECT SOUTHWESTERLY GALES OF 35-40KTS OVER
PORTIONS OF WESTERN AND CENTRAL LAKE SUPERIOR. BASED OFF THE
STRENGTH OF THE WINDS JUST ABOVE THE SURFACE...WOULDN/T BE SURPRISED
TO SEE SOME 45KT GUSTS AT THE HIGHER PLATFORMS AROUND ISLE ROYALE. A
COLD FRONT ASSOCIATED WITH THE LOW WILL SWEEP SOUTHEAST ACROSS LAKE
SUPERIOR ON FRIDAY...SHIFTING THE WINDS TO THE NORTHWEST AND
BRINGING AN END TO THE GALES. BEHIND THE FRONT...EXPECT WINDS TO 25-
30KTS BEFORE SHIFTING MORE NORTHERLY BEHIND A SECONDARY TROUGH ON
MOVING ACROSS LAKE SUPERIOR ON SATURDAY. WINDS WILL DIMINISH BEHIND
THE SECONDARY TROUGH AS A HIGH PRESSURE RIDGE SHIFTS SOUTH INTO THE
AREA SATURDAY NIGHT. 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 15KTS OR BELOW SUNDAY NIGHT INTO MONDAY.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
  GALE WARNING UNTIL 9 AM EST /8 AM CST/ THIS MORNING FOR LSZ162-
     263-264-266.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...TITUS
LONG TERM...KC
AVIATION...ROLFSON
MARINE...TITUS


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