Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 291227
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
727 AM EST THU JAN 29 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EST THU JAN 29 2015

WV AND LATEST RADAR IMAGERY SHOW IT WELL...THE DEEP MOISTURE SET UP
ACROSS CENTRAL UPPER MI IS QUICKLY EXITING E. THE SFC TROUGH SET UP
OVER W LAKE SUPERIOR AROUND 09Z THIS MORNING WILL EDGE TO THE E HALF
OF THE CWA SHORTLY AFTER DAYBREAK THIS IS WHEN WE WILL REALLY BEGIN
TO NOTICE SOME OF THOSE STRONGER N-NNW WINDS BEGIN /WINDS CURRENTLY
AROUND 12KTS AT CMX WILL BEGIN TO GUSTS 25-30KTS/.

-FZDZ HAS BEEN REPORTED OFF AND ON THIS MORNING AS THE MAIN BULK OF
MOISTURE EXISTS OVER CENTRAL AND E UPPER MI...AS STRONG HIGH
PRESSURE OVER CENTRAL SASKATCHEWAN NEARS. UTILIZED THE PROBABILITY
OF ICE PRESENT FROM THE RUC TO GET A BETTER HANDLE ON WHEN AND WHERE
-FZDZ MAY SET UP BEFORE COLD AIR PUSHES ACROSS ALL OF UPPER MI
/BASICALLY BY 18Z/ FOR ANY LINGERING MIXED PRECIP TO TRANSITION BACK
TO JUST -SHSN. LOOK FOR FALLING TEMPS THIS AFTERNOON AS THE COLDER
AIR SLIDES IN. 850MB TEMPS AROUND -10C EARLY THIS MORNING WILL FALL
THIS AFTERNOON...AND GET DOWN TO AROUND -17C BY 00Z...AND -20C BY
06Z FRIDAY. THE ARRIVAL OF THE COLDER AIR WILL BRING A BETTER CHANCE
OF LAKE EFFECT SNOW SHOWERS TO UPSLOPE LOCATIONS OVER THE W FAVORED
BY NNW WINDS.

LIMITING FACTORS FOR SIGNIFICANT SNOW ACCUMULATIONS OVER THE W THIRD
OF THE CWA LATER THIS AFTERNOON THROUGH THIS EVENING WILL BE THE
LOWERING DGZ TO AROUND 4KFT OR LESS BY 06Z FRIDAY...WINDS STILL
GUSTING 15-20KTS WILL KEEP SLR VALUES FROM RISING BACK UP TO
25:1 TOO FAST. HOWEVER...WITH THE 500MB TROUGH OVERHEAD AND AN
ADDITIONAL SHORTWAVE SLIDING THROUGH LATE THIS AFTERNOON THROUGH
THIS EVENING...SOME ENHANCEMENT IS EXPECTED. WILL KEEP SNOW AMOUNTS
AROUND 2IN OR LESS ACROSS THE W THIRD OF THE CWA.

ONE CONCERN FOR THE EVENING PERIOD WILL BE THE POTENTIAL OF A MESO
LOW SETTING UP OVER S CENTRAL LAKE SUPERIOR AFTER 03Z...KEEPING A
BAND OF MORE MODERATE SNOW OVER CENTRAL/E MARQUETTE COUNTY
AND W ALGER COUNTY. THE NAM AND REGIONAL WRF HIGHLIGHT THE
POTENTIAL. HAVE EXPANDED SNOW FARTHER W TO ACCOUNT FOR THIS...AS
WELL AS KEPT THE WINDS UP OVER S CENTRAL LAKE SUPERIOR A BIT LONGER
/WHICH SEEMS TO HAVE BEEN ALREADY ACCOUNTED FOR/. ENHANCED BY THE
WINDS GUSTING 25-35KTS...VISIBILITY RESTRICTIONS WILL BE A CONCERN
FOR THOSE TRAVELING ON M-28. EVEN WITHOUT ANY LAKE ENHANCEMENT
BLOWING AND DRIFTING SNOW COULD BE AN ISSUE...DEPENDING ON HOW SOLID
SNOW BANKS ON THE SIDE OF THE ROAD HAVE BECOME AND HOW MUCH SNOW HAS
BEEN ABLE TO ACCUMULATE ON THE ICE ALONG LAKE SUPERIOR.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 411 AM EST THU JAN 29 2015

FCST FOCUS IN THE MEDIUM AND EXTENDED RANGE WL BE ON THE IMPACT OF
SEVERAL CLIPPER TYPE SHRTWVS THAT ARE FCST TO MOVE THRU A MEAN UPR
TROF IN ERN NAMERICA. UNDER THE PERSISTENT NW FLOW ALOFT...EXPECT
BLO TO WELL BLO NORMAL TEMPS TO DOMINATE DURING THIS TIME WITH A
STEADY FEED OF CNDN AIR. WITH THE COLD AIR SURGES...LES WL BE AN
OBVIOUS CONCERN.

FRI...SFC HI PRES IS FCST TO SHIFT FM OVER MN TOWARD THE OH RIVER
VALLEY BE 00Z SAT. AS NW WINDS IN THE MRNG BACK TO THE W AND THEN
THE SW LATE...LINGERING LES OVER THE W WL BECOME CONFINED TO OVER
THE KEWEENAW AND END OVER THE E EXCEPT NEAR THE SHORE E OF GRAND
MARAIS TOWARD 00Z SAT. ALTHOUGH THE LK CLDS WL BE SHIFTING
OFFSHORE...MORE MID/HI CLDS IN ADVANCE OF ANOTHER SHRTWV MOVING SE
WITHIN THE NW FLOW ALF WL BE PUSHING INTO THE UPR LKS.

FRI NGT/SAT...SHRTWV EMBEDDED IN THE NW FLOW ALOFT WL BE MOVING INTO
NW MN AT 00Z SAT AND IS THEN FCST TO SLIDE SE THRU NCENTRAL WI BY
12Z SAT AND THEN ACROSS LOWER MI ON SAT. AT THE SAME TIME...ANOTHER
STRONGER SHRTWV WL BE MOVNG FM CENTRAL CANADA INTO FAR NW ONTARIO BY
12Z SAT BEFORE MOVING TO JUST S OF JAMES BAY BY 00Z SUN. UPR MI WL
BE IMPACTED MAINLY BY THE WEAKER SRN DISTURBANCE. ALTHOUGH A BAND OF
RELATIVELY WEAK QVECTOR CNVGC IS FCST TO SLIDE ACROSS UPR MI ON FRI
NGT INTO SAT MRNG ON THE CYC SIDE OF THIS SRN SHRTWV...ACCOMPANYING
ISENTROPIC ASCENT/MSTR INFLOW IS FCST TO BE RELATIVELY WEAK. SO WL
FCST ONLY CHC POPS OVER MOST OF THE CWA AND MAINLY BTWN 03Z SAT AND
15-18Z SAT...WHEN THE FORCING ACCOMPANYING THE SRN SHRTWV AND A COLD
FNT ATTENDANT TO THE NRN SHRTWV ARE FCST TO EXIT THE ERN CWA AND
GIVE WAY TO SOME VIGOROUS DEEP LYR QVECTOR DVGC. MAINTAINED SOME
LIKELY POPS OVER THE NRN TIER OF THE CWA CLOSE TO THE STRONGER NRN
SHRTWV AND WHERE SHARPER LLVL CNVGC WL ACCOMPANY THE SAT COLD FROPA.
THE COLDEST 00Z GFS/12Z ECMWF RUNS SHOW H85 TEMPS IN THE WAKE OF THE
SAT COLD FROPA PLUNGING AS LO AS -25C BY 00Z SUN...BUT QUICK
TRANSITION TO A MORE DIFFLUENT/ACYC H925 N FLOW AND INVRN BASE
FALLING TO H85-875 WL TEND TO LIMIT LES INTENSITY. RELATIVELY
MODERATE TEMPS INTO SAT MRNG WL FALL THRU THE AFTN AS THE COLDER AIR
SURGES INTO THE AREA IN THE STEADY N FLOW AHEAD OF ARCTIC HI PRES
BLDG SEWD IN SCENTRAL CANADA.

SAT NGT THRU SUN NGT...UPR MI WL REMAIN DOMINATED BY A COLD N
BACKING WNW LLVL FLOW OF ARCTIC AIR ASSOCIATED WITH ARCTIC HI PRES
MOVING FM OVER ALBERTA/SASKATCHEWAN AT 00Z SUN INTO THE UPR MS RIVER
VALLEY BY 12Z MON. EXPECT TEMPS TO RUN WELL BLO NORMAL AND LES TO
CONTINUE NEAR LK SUP WITH H85 TEMPS FCST TO REMAIN NOT FAR FM -22C
TO -25C. SAT NGT COULD BE PARTICULARLY CHILLY OVER THE E WITH THE N
H925 FLOW ALLOWING SOME DRAINAGE OF COLD AIR INTO THAT AREA OFF
ONTARIO. ALTHOUGH FCST ACYC NATURE OF THE H925 FLOW AND NEAR ABSENCE
OF THE DGZ ASSOCIATED WITH THE VERY LO H85 TEMPS WL LIMIT LES
AMOUNTS...SOME OF THE MODELS HINT THERE MAY BE SOME ENHANCED CNVGC
ALONG A LK INDUCED TROF STRETCHING FM THE KEWEENAW TOWARD WHITEFISH
PT THAT WL INTENSIFY AS THE LARGER PRES GRADIENT RELAXES AND A
SHRTWV EMBEDDED IN THE NW FLOW APRCHS ON SUN/SUN NGT. RAISED POPS
WELL ABOVE THE CONSENSUS TO LIKELY ALONG THIS AXIS.

MON...LES ALONG THE LK INDUCED TROF WL BEGIN TO DIMINISH/SHIFT OUT
INTO LK SUP WITH THE APRCH OF A SFC RDG AXIS EXTENDING N FM THE HI
CENTER SHIFTING TOWARD THE OH VALLEY AND THE ASSOCIATED BACKING LLVL
FLOW. BUT THE MORE W WIND COMPONENT WL MEAN LESS LK MODERATION AND
PERSISTENT WELL BLO NORMAL SFC TEMPS EVEN AS THE H85 TEMPS MODERATE
A BIT FASTER.

TUE/WED...THE LONGER RANGE GUIDANCE HINTS ANOTHER CLIPPER TYPE
DISTURBANCE WL PASS THRU THE UPR LKS ON TUE...WITH H85 TEMPS
REBOUNDING TO NEAR -15C IN THE WAA BTWN THIS FEATURE AND HI PRES
MOVING INTO THE MID ATLANTIC. BUT ANOTHER ARCTIC SURGE LOOKS TO
FOLLOW ON WED AS THE SHRTWV PASSAGE REAMPLIFIES THE ERN TROF AND THE
NW FLOW IN ADVANCE OF THE NEXT CNDN HI SINKING INTO THE NRN PLAINS
ADVECTS H85 TEMPS AS LO AS -25 TO -28C INTO THE UPR LKS.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 725 AM EST THU JAN 29 2015

GUSTY N-NNW WINDS ARE BEGINNING TO TAKE HOLD AT IWD AND
CMX...AND WILL PUSH INTO SAW OVER THE NEXT 2 HOURS. MUCH DRIER AIR
WORKING IN WILL BE WORKING AGAINST THE STRONG UPSLOPE WINDS
TODAY...AND WITH COLDER AIR PUSHING ACROSS LAKE SUPERIOR...EXPECT
NEARLY STEADY STATE CONDITIONS WITH MVFR CEILINGS. IFR CONDITIONS
MAY BE POSSIBLE IN SNOW AND BLOWING SNOW LATER THIS AFTERNOON AND
THIS EVENING AS AN UPPER LEVEL DISTURBANCE ENHANCES SNOW SHOWERS
BRIEFLY. OTHERWISE...LOOK FOR SLOWLY IMPROVING CONDITIONS TOWARDS
DAYBREAK FRIDAY AS WINDS RELAX TO AROUND 10KS OR LESS MORE OUT OF THE
NW AND LOW LEVEL MOISTURE DIMINISHES.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 AM EST THU JAN 29 2015

LOW PRESSURE SYSTEM NEAR N LAKE SUPERIOR THIS MORNING WILL MOVE INTO
QUEBEC THIS AFTERNOON WHILE ANOTHER LOW NEAR CHICAGO SHIFTS EAST
INTO NEW ENGLAND ON FRIDAY MORNING. MEANWHILE...A HIGH OVER S
CENTRAL CANADA WILL MOVE SE INTO MN ON FRIDAY. IN BETWEEN THE
EXITING LOW AND NEARING HIGH...STRONG N-NNW GALES GUSTING 35 TO
AROUND 40KTS WILL DEVELOP THIS AFTERNOON OVER MAINLY CENTRAL AND E
LAKE SUPERIOR. LOOK FOR WINDS TO SLOWLY DIMINISH LATE THIS EVENING
AND OVERNIGHT...WITH GUSTS REMAINING 25-30KTS THROUGH DAYBREAK
FRIDAY. GIVEN THE STRONG WINDS...AND COLDER AIR SURGING IN...HEAVY
FREEZING SPRAY WILL BE POSSIBLE OVER THIS SAME AREA INTO EARLY
FRIDAY MORNING. WINDS WILL THEN QUICKLY DIMINISH AND REMAIN LESS
THAN 30KTS THROUGH FRIDAY NIGHT.

AS THIS HIGH DRIFTS INTO THE OH RIVER VALLEY ON SATURDAY...A TROUGH
WILL SLIDE ACROSS THE UPPER GREAT LAKES. A FEW N TO NW GUSTS OF 30
TO NEAR 35KTS WILL BE POSSIBLE SATURDAY AFTERNOON AND EVENING.
EXPECT HIGH PRESSURE OVER CENTRAL CANADA ON SATURDAY TO MOVE SE INTO
THE N PLAINS ON SUNDAY...AND THE MID MS RIVER VALLEY ON MONDAY.
WINDS SHOULD DIMINISH FOR A TIME SUN BEFORE INCREASING AGAIN MONDAY.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
  HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 7 AM
     EST FRIDAY FOR LSZ264-266-267.

  GALE WARNING FROM 1 PM THIS AFTERNOON TO 4 AM EST FRIDAY FOR
     LSZ267.

  GALE WARNING UNTIL 4 AM EST FRIDAY FOR LSZ265-266.

  GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ263-264.

  HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 1 AM
     EST FRIDAY FOR LSZ263.

LAKE MICHIGAN...
NONE.
&&

$$

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



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