Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 212311
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
611 PM EST FRI NOV 21 2014

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 406 PM EST FRI NOV 21 2014

WV IMAGERY AND RUC ANALYSIS INDICATED ZONAL MID/UPPER LEVEL FLOW
THROUGH THE NW AND N CNTRL CONUS WITH A WEAK SHORTWAVE TROUGH OVER
NORTH DAKOTA. A VIGOROUS SRN STREAM SHRTWV WAS SLIDING THROUGH SW
ARIZONA. AT THE SFC...SW FLOW WAS INCREASING FROM THE UPPER MS VALLEY
INTO THE NRN LAKES AS THE PRES GRADIENT TIGHTENS BETWEEN A 995 MB LOW
OVER MANITOBA AND 1034 MB HIGH OVER THE OH VALLEY. WAA INTO THE
REGION HAS BROUGHT AN INCREASE IN MID CLOUDS ACROSS UPPER MI WITH
ANOTHER BATCH UPSTREAM FROM MN INTO CNTRL WI. THE LOWER CLOUDS
REMAINED WELL TO THE SOUTH OVER MO AND SRN IA.

TONIGHT...EXPECT THAT THE STRONG SSW LOW LEVEL WAA PATTERN WILL
RAPIDLY BRING LOW LEVEL MOISTURE TOWARD THE AREA TO SUPPORT LOWER
CLOUDS INTO THE CWA. ALTHOUGH THE LOW LEVEL ISENTROPIC LIFT WILL BE
MARGINAL TO PRODUCE PCPN...UPSLOPE FLOW INTO MUCH OF THE AREA SHOULD
BE ENOUGH TO SUPPORT SOME LIGHT PCPN...ESPECIALLY OVER THE EAST HALF
WHERE ADDITIONAL MOISTURE FROM LAKE MICHIGAN IS AVAILABLE. MODEL
SOUNDINGS SUGGEST THAT THE 3K-8K DRY/WARM LAYER WILL BE STRONG ENOUGH
TO LIMIT/PREVENT ICE CRYSTAL AVAILABILITY INTO THE LOWER MOIST LAYER.
SO...EXPECT -FZDZ WILL BE THE PREDOMINANT PCPN TYPE. EVEN THOUGH
LITTLE IF ANY MEASURABLE PCPN IS EXPECTED...EVEN A VERY THIN COATING
OF -FZDZ COULD RESULT IN HAZARDOUS CONDITIONS ON UNTREATED ROADS.

SAT...THE COMBINATION OF DAYTIME HEATING AND ADDITIONAL WAA WILL
PUSH TEMPS ABOVE FREEZING IN MOST AREAS BY NOON CHANGING ANY
LINGERING FREEZING DRIZZLE TO DRIZZLE. EXPECT THE PCPN CHANCES TO
DIMINISH AS THE LOW LEVEL WAA WEAKENS DURING THE LATE MORNING AND
AFTERNOON. OTHERWISE...TEMPS SHOULD CLIMB TO READINGS AT OR ABOVE
NORMAL IN THE MID TO UPPER 30S.

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 430 PM EST FRI NOV 21 2014

A VERY ACTIVE WEEK IS IN STORE ACROSS THE UPPER GREAT LAKES AS A
POTENT MID-LEVEL SYSTEM DIGS INTO THE NORTHERN ROCKIES/PLAINS. THIS
WILL BRING A DECENT SURGE OF WARM AIR ACROSS THE AREA BY LATE
WEEKEND...BRINGING THE AREA BACK INTO ABOVE-AVERAGE TEMPERATURES FOR
A SHORT PERIOD. WITH THIS WILL COME A DECENT ROUND OF RAIN ACROSS
MAINLY CENTRAL AND EASTERN UPPER MI SUNDAY NIGHT INTO MONDAY. A
QUICK TRANSITION BACK TO WINTER WILL THEN TAKE PLACE ON MONDAY AS
THE TROUGH AND ASSOCIATED STRONG SURFACE LOW MOVE NORTHEAST OF THE
REGION...BRINGING STRONG CAA AND THE POTENTIAL FOR A DECENT SNOWFALL
ACROSS THE WESTERN CWA.

SATURDAY NIGHT...AS WEAK MID-LEVEL RIDGING WORKS ACROSS THE UPPER
GREAT LAKES...THIS LOOKS TO BE THE QUIETEST PERIOD THROUGH AT LEAST
TUESDAY. SIGNIFICANTLY DRY AIR ABOVE 900 HPA AND THE LACK OF ANY
APPRECIABLE MID/UPPER-LEVEL FORCING SHOULD LIMIT ANY DEEPER PRECIP
POTENTIAL. THE ONLY CONCERN IS A CHANCE FOR DZ/FZDZ ASSOCIATED WITH
WEAK LOW-LEVEL WAA SOUTH LATE IN THE NIGHT.

SUNDAY AND MONDAY...SIGNIFICANT CHANGES ARE SET TO BEGIN SUNDAY AS
AN ACTIVE NORTHERN AND SOUTHERN STREAM TAKE AIM ON THE UPPER GREAT
LAKES. FIRST...A LOOK AT THE LARGE SCALE PICTURE. AS THE
AFOREMENTIONED TROUGH OVER THE NORTHERN ROCKIES TRACKS ESE TOWARD
THE UPPER MS VALLEY...ANOTHER TROUGH ACROSS TX SATURDAY EVENING WILL
EJECT NE INTO THE UPPER GREAT LAKES. THE MERGING PIECES OF ENERGY
COMBINED WITH A QUICKLY DEVELOPING 120KT UPPER JET STREAK WILL
INDUCE A SFC LOW SOMEWHERE FROM EASTERN UPPER MI TO NORTHERN LOWER
MI BY 12Z MONDAY.

UPPER MI FINDS ITSELF CAUGHT IN A CONVOLUTED PATTERN SUNDAY MORNING
BEFORE THE TWO SYSTEMS CONSOLIDATE OVER THE AREA. OVERALL SYNOPTIC
FORCING REMAINS LIMITED TO START THE DAY...BUT LOW-LEVEL MOISTURE
TRANSPORT RESULTING IN A DEEPENING MOIST LAYER WILL ALLOW FOR
INCREASING CHANCES OF FZDZ/DZ IN THE MORNING...AND RAIN THROUGHOUT
THE AFTERNOON. BEST CHANCES DURING THE DAY LOOK TO BE ACROSS THE
CENTRAL AND EASTERN CWA WITH UPSLOPE AND MOISTURE INFLUENCES FROM SE
WINDS OFF LAKE MI. TEMPS THROUGH THE MOIST LAYER WILL REMAIN WARM
ENOUGH FOR SUPER-COOLED LIQUID...INTRODUCING CONTINUED CONCERN FOR
FZDZ/FZRA IN THE MORNING. GIVEN OUR RECENT SUB-FREEZING
STRETCH...CLEARED ROADS MAY SEE SOME ICING EVEN AS TEMPS WARM INTO
THE 30S TO LOW 40S DURING THE DAY SUNDAY. LATEST MDOT ROAD SENSORS
ARE SHOWING SUB-FREEZING TEMPS DOWN AT LEAST 24 INCHES BELOW THE
ROAD AND SUB-20F TEMPS DOWN TO AT LEAST 6 INCHES FOR NEARLY ALL
UPPER MI HIGHWAYS. WILL THEREFORE EXTEND THE FZDZ/FZRA POTENTIAL
THROUGH SUNDAY MORNING UNTIL AIR TEMPS WARM WELL-ABOVE FREEZING
SUNDAY AFTERNOON.

SIGNIFICANT MOISTURE TRANSPORT/ISENTROPIC LIFT WILL FOCUS ACROSS THE
EAST HALF OF THE CWA LATE SUNDAY AFTERNOON THROUGH MUCH OF THE
NIGHT. MEANWHILE...DECENT LIFT UNDER THE RIGHT ENTRANCE OF THE UPPER
JET WILL SPREAD ACROSS THE AREA. THIS SHOULD BRING WIDESPREAD PRECIP
OVER THE ENTIRE CWA THROUGHOUT THE NIGHT. WARMING TEMPS THROUGHOUT
THE COLUMN WILL RESULT IN A PTYPE OF ALL RAIN FOR THE ENTIRE CWA
SUNDAY AFTERNOON AND EVENING...AND ALL BUT THE WESTERN CWA LATE
SUNDAY NIGHT. WITH THE DECENT FORCING AND SUFFICIENT
MOISTURE...RAINFALL AMOUNTS LATE SUNDAY AFTERNOON THROUGH MONDAY
MORNING ARE EXPECTED TO SURPASS 0.75IN ACROSS THE EAST HALF. THIS
MAY BE A LITTLE CONSERVATIVE...BUT WOULD LIKE TO SEE BETTER
MID-LEVEL SUPPORT IN CONJUNCTION WITH THE UPPER JET BEFORE
INCREASING PRECIP AMOUNTS ANY FURTHER.

LATE SUNDAY NIGHT INTO MONDAY STARTS THE TRANSITION BACK TO SNOW AS
THE SFC LOW REACHES EASTERN UPPER MI LATE SUNDAY NIGHT. AS THE
SOUTHERN AND NORTHERN STREAM MERGE...THE NEW DEEPER TROUGH NEARLY
STALLS OVER THE UPPER GREAT LAKES. AN IMPRESSIVE 140KT UPPER JET
OVER THE MID MS VALLEY COMBINED WITH THE DEPARTING 120KT JET MOVING
OVER QUEBEC WILL BE ENOUGH TO KEEP A DEEPER SFC LOW OVER
ONTARIO/QUEBEC. MEANWHILE...A COMPACT TROUGH NEAR SEATTLE SUNDAY
AFTERNOON WILL DIG INTO THE DEPARTING THE TROUGH...FURTHER SLOWING
ITS MOVEMENT. ALL OF THIS COMES TOGETHER TO PRODUCE A LAGGING
LOW-LEVEL TROUGH AND DEFORMATION ZONE OVER UPPER MI ON MONDAY AND
MONDAY NIGHT. WITH LAKE ENHANCEMENT KICKING IN WITH N/NNW
WINDS...THERE IS INCREASING POTENTIAL FOR MODERATE TO POSSIBLY HEAVY
SNOW ACROSS THE NORTHWEST HALF OF UPPER MI. THE 12Z NAM AND 12Z GFS
HAVE BOTH COME IN WITH MUCH HIGHER QPF ACROSS THE WESTERN AND
CENTRAL CWA ON MONDAY. THOUGH THE ECMWF TAKES THE LOW ACROSS
NORTHERN LOWER MI...THE MID/UPPER-LEVEL SUPPORT PAINTS HIGHER QPF
AMOUNTS ACROSS THE WESTERN CWA AS WELL. THE TRANSITION TO SNOW
SHOULD BE UNDERWAY ACROSS THE FAR WEST BY DAYBREAK MONDAY...THEN
CONTINUE PRESSING EASTWARD. BY EARLY AFTERNOON...ALL BUT SOME OF THE
SHORELINE LOCATIONS OF THE WEST HALF SHOULD CHANGE OVER TO SNOW.
WHILE THERE IS SOME UNCERTAINTY IN HOW QUICK SNOW RATIOS INCREASE
DURING THE DAY...SEVERAL INCHES OF SNOW SHOULD FALL FOR MOST OF THE
NW HALF OF THE CWA MONDAY AFTERNOON. DO NOT WANT TO COMPLETELY JUMP
ON BOARD WITH THE NEW GUIDANCE QUITE YET...BUT THERE IS ENOUGH
EVIDENCE TO AT LEAST INCREASE SNOW AMOUNTS A BIT. THE EASTERN CWA
SHOULD SEE AT LEAST SOME ACCUMULATIONS...BUT A LATER TRANSITION TO
ALL SNOW COMBINED WITH A LESS FAVORABLE LOCATION OF THE FORCING WILL
KEEP AMOUNTS LOWER. WILL NEED TO MONITOR THIS OVER THE NEXT COUPLE
DAYS AS AT LEAST SOME WINTER WX HEADLINES MAY BE NEEDED.

MONDAY NIGHT AND TUESDAY...MOISTURE CONTINUING TO WRAP AROUND
THE BACKSIDE OF THE DEPARTING LOW COMBINED WITH UPSLOPE AND LAKE
INFLUENCE WILL GENERATE SNOW FOR THE N TO NNW WIND SNOW BELTS.
ANOTHER SEVERAL INCHES OF SNOW WILL BE POSSIBLE MONDAY NIGHT. BY
TUESDAY...SOME DRIER AIR WILL BEGIN TO WORK IN FROM THE WEST AS
INVERSION HEIGHTS FALL BELOW 5KFT...CUTTING OFF MUCH OF THE RESIDUAL
LAKE EFFECT PRECIP.

WEDNESDAY THROUGH FRIDAY...ANOTHER TROUGH DIGGING OUT OF
NORTH-CENTRAL CANADA WILL MOVE SE ACROSS THE UPPER GREAT LAKES
TUESDAY NIGHT INTO WEDNESDAY. ACCUMULATING SNOW WILL BE POSSIBLE
WEDNESDAY WITH THIS SYSTEM...BUT ITS TRACK AND STRENGTH ARE TOO
VARIABLE IN THE MODELS TO PIN DOWN LOCATIONS AT THIS TIME. MUCH
COLDER AIR ARRIVES BEHIND THE LOW AND INDUCES LES FOR THE NNW WIND
SNOW BELTS WEDNESDAY NIGHT THROUGH THANKSGIVING. A SLOWLY MODERATING
850 HPA AIRMASS WITH TEMPS -15 TO -20C WILL RESULT IN THE WEATHER
FEELING MORE LIKE CHRISTMAS THAN THANKSGIVING AS HIGHS STRUGGLE TO
GET OUT OF THE TEENS FOR AT LEAST THE WEST AND CENTRAL. BY
FRIDAY...ANOTHER PATTERN CHANGE WILL BRING MODERATING CONDITIONS TO
END THE WEEK.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 610 PM EST FRI NOV 21 2014

LLWS IS EXPECTED AS THE LOW LEVEL JET REALLY INCREASES 1-2KFT ABOVE
THE SURFACE...ESPECIALLY AT KSAW. HAVE LEFT GUSTS UP TO ACCOUNT FOR
THIS. MVFR CLOUDS WILL BE PUSHING NORTH-NORTHEAST INTO THE AREA
TONIGHT. THIS WILL LEAD TO A QUICK DROP IN CEILINGS LATE
TONIGHT...WITH KSAW HAVING THE LOWEST VALUES THAT SHOULD FALL INTO
THE IFR RANGE LATE. WITH THESE LOW CLOUDS...THERE IS THE POTENTIAL
FOR LIGHT FREEZING DRIZZLE LATE TONIGHT...ESPECIALLY AT KSAW.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 PM EST FRI NOV 21 2014
WINDS WILL CONTINUE TO INCREASE WITH A TIGHT PRES GRADIENT BETWEEN
LOW PRES OVER THE PLAINS AND A RIDGE OVER THE OH VALLEY.
WINDS TOT 30KTS WITH FREQUENT GALE FORCE GUSTS TO 35 KNOTS ARE
EXPECTED TONIGHT. THE PRESSURE GRADIENT WILL DECREASE SATURDAY INTO
SATURDAY NIGHT AS A TROUGH TRAILING THE CANADIAN LOW DROPS SOUTHEAST
OVER LAKE SUPERIOR. A DEVELOPING LOW IN THE CENTRAL/SOUTHERN PLAINS
ON SATURDAY NIGHT WILL LIFT NORTHEAST THROUGH THE GREAT LAKES REGION
TO NEAR THE STRAITS MONDAY MORNING AT AROUND 28.9 INCHES. AS THE LOW
LIFTS TO THE NORTHEAST ON MONDAY NORTHERLY GALES ARE LIKELY WHICH
COULD PERSIST THROUGH MONDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
  GALE WARNING UNTIL 7 AM EST SATURDAY FOR LSZ266-267.

  GALE WARNING UNTIL 7 AM EST /6 AM CST/ SATURDAY FOR LSZ162-263-
     264.

LAKE MICHIGAN...
  GALE WARNING UNTIL 10 AM EST SATURDAY FOR LMZ248.

&&

$$

SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...07
MARINE...JLB





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