Area Forecast Discussion
Issued by NWS Marquette, MI

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203
FXUS63 KMQT 131000
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
500 AM EST SAT FEB 13 2016

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 456 AM EST SAT FEB 13 2016

...LAKE EFFECT SNOW AND BLOWING SNOW DIMINISH THROUGH THE DAY...

IN THE LARGE SCALE...DEEP TROUGHING REMAINS OVER EASTERN CANADA AND
THE GREAT LAKES. UPPER LOW WITH H85 TEMPS AS LOW AS -39C AT MOOSINEE
ONTARIO LAST EVENING PROVIDING THE CENTER OF TROUGH DRIFTS ACROSS
QUEBEC TODAY WHICH PLACES SYNOPTIC SUBSIDENCE ACROSS UPPER GREAT
LAKES TODAY INTO TONIGHT. AT THE SFC...LAKE INDUCED TROUGHING ACROSS
MUCH OF THE GREAT LAKES GRADUALLY IS REPLACED BY SFC RIDGE ATTM
FM SCNTRL CANADA TO THE CENTRAL PLAINS. ARRIVAL OF RIDGE WILL LEAD
TO DRYING BENEATH AN ALREADY LOWERING INVERSION AND ULTIMATELY WILL
RESULT IN WINDS BACKING TO SSW-S LEADING TO END OF LINGERING LAKE
EFFECT OVER EASTERN LK SUPERIOR. UNTIL THEN THOUGH...LAKE EFFECT
WILL CONTINUE WITH STEADY NW FLOW AND INVERIONS RUNNING FM 3-5KFT
WEST TO OVER 5KFT OVER EASTERN SUPERIOR AND DOWNSTREAM OVER UPR
MICHIGAN. H85 TEMPS START OUT THE DAY AROUND -25C WEST TO -28C
EAST...THEN RISE BY LATE TODAY TO -20C WEST AND -25C EAST. AS TEMPS
WITHIN LAKE EFFECT MOIST LAYER REMAIN LOWER THAN -20C...DO NOT
EXPECT SLR/S TO BE MORE THAN 15:1 MOST AREAS TODAY SO SNOW AMOUNTS
SHOULD STAY ON THE LOWER SIDE...PERHAPS 2-4 INCHES FOR SNOW BELTS OF
EASTERN CWA. WINDS IN MIXED LAYER STILL 20-30 MPH INTO AFTN AND THIS
ALONG WITH SMALLER SNOW FLAKES WILL LEAD TO POOR VSBY IN THE SNOW
SHOWERS.

HAVE DROPPED WARNINGS FOR MARQUETTE AND ALGER COUNTY AS WEATHER WEB
CAMS/ROAD WEATHER VSBY SENSORS AND LAW ENFORCEMENT REPORTS INDICATED
CONDITIONS HAVE IMPROVED SINCE FRI. WILL ROLL WITH LAKE EFFECT ADVY
FOR THESE AREAS AND EXTEND LAKE EFFECT ADVY FOR DELTA AND SOUTHERN
SCHOOLCRAFT. OUT WEST...DRY AIR BLO INVERSION TAKING TOLL ON LAKE
EFFECT BUT STILL ISOLD HEAVIER SNOW SHOWERS ATTM. SO...WILL LET ADVY
RUN TIL 12Z. BASED ON OBSERVATIONAL DATA AND LAW ENFORCEMENT
REPORTS...PRIMARY AREA STILL SEEING BLSN/POOR VSBY IS OVER KEWEENAW
COUNTY WHERE WINDS AT P59 WILL GUST TO 30 MPH TIL AROUND DAYBREAK
THEN DIMINISH THROUGH THE DAY. WIND CHILL ADVY ALONG WI BORDER GOES
UNTIL 15Z AND AFTER COORD WITH WFO GRB AND WFO DLH...WILL LET THAT
CONTINUE THOUGH DUE TO LIGHTER WINDS IT REMAINS MARGINAL ATTM.

INTO TONIGHT...LAKE EFFECT DIMINISHES WITH ARRIVAL OF SFC RIDGE. ONE
THING TO WATCH IS WHATEVER LAKE EFFECT IS ONGOING THIS EVENING IN
CONVERGENCE AREA OVER ALGER/NORTHERN SCHOOLCRAFT COUNTIES COULD
BECOME MUCH MORE FLUFFY BEFORE IT ENDS. INVERSIONS THIS EVENING
WILL BE AROUND 3KFT...SO THAT WILL LIMIT INTENSITY...BUT IF AN AREA
OF SNOW SHOWERS PERSISTS MAY SEE QUICK INCH OR TWO OF ACCUMS.
THANKFULLY WINDS WILL BE LIGHT SO BLSN SHOULD NOT BE ISSUE AT ALL.
NO REASON TO ALTER GOING TEMP FORECAST TONIGHT AS WHERE LAKE CLOUDS
CLEAR OUT THIS EVENING TEMPS SHOULD PLUMMET. HIGH CLOUDS INCREASE
LATE BUT THERE WILL BE PLENTY OF TIME BENEATH THE RIDGE TO ALLOW
TEMPS AT TYPICAL COLD SPOTS TO END UP IN THE TEENS BLO ZERO. WITH
DRAINAGE FLOW OUT OF ONTARIO BECOMING MORE OF A FACTOR...LOWERED
MINS OVER FAR EASTERN CWA TO 10-15 BLO ZERO.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 410 AM EST SAT FEB 13 2016

A WAA PATTERN BTWN HI PRES SLIDING E INTO THE MID ATLANTIC AND
APRCHG SHRTWVS/LO PRES TROF FM SCENTRAL CANADA/THE NRN PLAINS WL
BRING SOME LIGHT SN TO UPR MI FM LATER ON SUN INTO MON. THE BEST CHC
FOR THIS PCPN WL BE OVER THE E HALF DOWNWIND OF LK MI AS THE AIRMASS
IN PLACE WL BE COLD ENUF TO SUPPORT SOME LK ENHANCED SN OFF THAT
BODY OF WATER. THE PASSAGE OF ANOTHER LO PRES/COLD FNT LATE MON
NGT/TUE WL BRING ANOTHER ROUND OF LES INTO WED...BUT AT THIS POINT
THIS PCPN LOOKS TO REMAIN ON THE RELATIVELY LGT SIDE. HI PRES WL
MOVE INTO THE AREA ON WED AND DIMINISH LINGERING LES. THERE WL
LIKELY BE SOME MIXED PCPN AT THE END OF THE WEEK AS THE UPR FLOW
TURNS MORE ZONAL AND ALLOWS MORE MODERATE PACIFIC AIR TO OVERSPREAD
THE AREA AHEAD OF AN APRCHG LO PRES.

SUN...SHRTWV DIGGING SEWD FM THE NRN PLAINS TOWARD THE LOWER GREAT
LKS IS PROGGED TO PASS FAR ENUF TO THE S SO THAT ACCOMPANYING DEEP
LYR QVECTOR CNVGC AND STRONGER WAA/ISENTROPIC ASCENT WL MISS THE
CWA. BUT MOST OF THE MODELS DO INDICATE SOME LES WL DVLP OFF LK MI
AND IMPACT MAINLY THE SE CWA WITH H85 TEMPS STARTING THE DAY ARND
-16C/-17C REBOUNDING TO ARND -14C LATE IN THE DAY IN THE SLY FLOW
BTWN DEPARTING HI PRES MOVING INTO THE MID ATLANTIC STATES AND A LOW
PRES TROF STRETCHING FM SCENTRAL CANADA INTO THE NRN PLAINS. BUT
LARGER SCALE ACYC H925 FLOW AND RELATIVELY LO SUBSIDENCE INVRN BASE
ARND 4K FT AGL WL LIMIT THE INTENSITY OF THIS PCPN. AWAY FM THE CLDS
OFF LK MI...EXPECT ONLY SOME HI CLDS AS FCST SDNGS SHOW VERY DRY AIR
BLO H6. SFC TEMPS WL REBOUND AT LEAST CLOSER TO NORMAL WITH SOME
FILTERED SUNSHINE AWAY FM THE LK MI CLDS.

SUN NGT/MON...THE APRCH OF ANOTHER SHRTWV AND SOME DPVA/DEEP LYR
QVECTOR CNVGC AS WELL AS CONTINUED MODEST WAA/ISENTROPIC ASCENT WL
BRING SOME LO CHC POPS TO MOST OF THE CWA ON SUN NGT INTO MON
MRNG...WHEN THE SHRTWV/ACCOMPANYING FORCING ARE PROGGED TO EXIT TO
THE E. BETTER PCPN CHCS WL LINGER DOWNSTREAM OF LK MI...WHERE THERE
COULD BE SOME MODEST ENHANCEMENT AS THE INVRN BASE RISES WITH THE
DYNAMIC FORCING/DEEPER MSTR/H85 TEMPS LINGERING ARND -12C. THE
ARRIVAL OF LARGER SCALE SUBSIDENCE/MID LVL DRYING IN THE WAKE OF THE
PASSING SHRTWV WL BRING DIMINISHING POPS ON MON AFTN. VEERING H925
WINDS TOWARD THE WSW AND RISING H85 TEMPS TOWARD -10C WL ALSO END
THE LES INTO THE SE COUNTIES. EXPECT TEMPS TO REACH AT LEAST NORMAL
ON MON WITH THE INFLUX OF WARMER H85 AIR.

MON NGT THRU TUE NGT...MEDIUM RANGE GUIDANCE INDICATES ANOTHER
SHRTWV WL DIG SE THRU NW ONTARIO INTO THE ERN TROF AND DRAG A COLD
FNT THRU UPR MI LATE MON NGT/TUE MRNG. WHILE THERE ARE LIKELY TO BE
SOME SN SHOWERS ASSOCIATED WITH THE FROPA MAINLY NEAR LK SUP...
PASSAGE OF ANOTHER DISTURBANCE TO THE SW THAT WL LIMIT MSTR INFLOW
INTO THE UPR LKS AND TRACK OF THE SHRTWV/STRONGER DYNAMIC FORCING TO
THE N WL LIMIT POPS OVERALL IN ADVANCE OF THE DISTURBANCE. SOME LES
IS LIKELY TO FOLLOW THE FROPA AS THE N FLOW BEHIND THE FROPA DROPS
H85 TEMPS AT LEAST CLOSE TO -20C...BUT RATHER DRY NATURE OF THE
INCOMING AIRMASS AS WELL AS STRENGTHENING/LOWERING SUBSIDENCE INVRN
TOWARD 3K FT ON TUE NGT WL LIKELY LIMIT THE INTENSITY OF THIS ROUND
OF LES. H925 N WINDS UP TO ABOUT 30 KTS MAY RESULT IN SOME BLSN NEAR
LK SUP.

WED THRU FRI...TRAILING SFC HI PRES BLDG INTO THE UPR LKS ON WED WL
DIMINISH LINGERING LES. AS THIS HI SHIFTS TO THE E AS THE UPR FLOW
TENDS TOWARD A MORE ZONAL CONFIGURATION...STRONG SLY FLOW/WAA IS
FCST TO DVLP ON THU AHEAD OF A SHRTWV MOVING E THRU THE NRN ROCKIES/
MSLP FALLS OVER THE NRN PLAINS. THIS SLY FLOW IS PROGGED TO DRAW
MUCH WARMER AIR INTO THE UPR LKS...WITH H85 TEMPS FCST TO RISE ABOVE
0C OVER A GOOD PORTION OF THE CWA ON THU NGT INTO FRI. WITH THIS
ELEVATED WARM LYR...CLOSER APRCH OF SHRTWV/SFC LO PRES WL BRING SOME
MIXED PCPN THAT MAY CHANGE TO PLAIN RA FOR AT LEAST A TIME OVER MUCH
OF THE CWA DEPENDING ON THE DEGREE OF SFC WARMING. HOWEVER...THE 00Z
RUNS OF THE GFS AND ESPECIALLY THE ECMWF HAVE TRENDED TOWARD EITHER
MORE RESILIENT COLD AIR OR A QUICKER RETURN OF COLDER AIR BY LATER
FRI. SO THERE IS MUCH UNCERTAINTY AS TO THE EVENTUAL OUTCOME FOR
PTYPE LATE IN THE WEEK.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1227 AM EST SAT FEB 13 2016

GUSTY NW WINDS AND FINE SNOWFLAKES WILL CONTINUE IFR VSBYS AT KCMX
AND MVFR TO IFR VSBYS AT KIWD THROUGH MUCH OF THE OVERNIGHT. AS
WINDS SLOWLY BACK AND DIMINISH THROUGH THE DAY ON SATURDAY THERE
WILL BE GRADUAL IMPROVEMENT TO MVFR CONDIITONS AT KCMX TOWARD SAT
EVENING AND TO VFR CONDITIONS AT KIWD BY SAT AFTERNOON. LESS
FAVORABLE NW WIND DIRECTION FOR LAKE EFFECT SNOW SHOULD KEEP KSAW
VFR THROUGH FCST PD.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 AM EST SAT FEB 13 2016

EXPECT N WINDS UP TO 25-30 KTS...WITH A FEW GALE FORCE GUSTS TO 35
KTS OVER MAINLY THE E HALF THIS MORNING...TO DIMINISH W-E TODAY AND
TONIGHT AS A HI PRES RIDGE MOVES THRU THE WESTERN GREAT LAKES.
ONGOING HEAVY FREEZING SPRAY WILL ALSO DIMINISH AS THE WAVES SUBSIDE.
ONCE THIS HIGH DRIFTS TO THE E...EXPECT AN INCREASING S WIND THAT
WILL REACH UP TO 25-30 KTS ON SUN INTO MON UNDER THE TIGHTENING PRES
GRADIENT BETWEEN THE DEPARTING HI AND AN APPROACHING LO PRES TROF IN
THE PLAINS. ALTHOUGH WINDS WILL DIMINISH LATER ON MON...ANOTHER ROUND
OF STRONG NNW WINDS UP TO 30 KTS WILL DEVELOP ON TUE/TUE NIGHT
FOLLOWING A COLD FRONTAL PASSAGE. NOT OUT OF THE QUESTION THERE COULD
BE SOME MARGINAL GALE FORCE GUSTS. LIGHTER WINDS WILL RETURN ON WED
WITH ANOTHER HI PRES RIDGE.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR
     MIZ001>003.

  LAKE EFFECT SNOW ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
     MIZ005-013-014.

  WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR MIZ009>012.

  LAKE EFFECT SNOW ADVISORY UNTIL 6 PM EST THIS EVENING FOR MIZ006-
     007-085.

LAKE SUPERIOR...
  HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THIS EVENING FOR
     LSZ265>267.

  HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
     LSZ264.

  HEAVY FREEZING SPRAY WARNING UNTIL 10 AM EST THIS MORNING FOR
     LSZ263.

LAKE MICHIGAN...
NONE.
&&

$$

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



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