Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 202157
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
457 PM EST THU NOV 20 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 406 PM EST THU NOV 20 2014

OVERALL CONDITIONS SHOULD IMPROVE OVER THE NEXT 12 TO 18 HOURS AS
LAKE EFFECT SNOW DIMINISHES FOR THE NORTHWEST WIND SNOW BELTS.

MODERATE TO HEAVY LAKE EFFECT SNOW BANDS HAVE BEEN RATHER PERSISTENT
FOR THE NW-WIND SNOW BELTS TODAY...ESPECIALLY AROUND IRONWOOD AND
GRAND MARAIS. HOWEVER...LOWERING INVERSION HEIGHTS ARE FINALLY
MAKING THEIR PRESENCE FELT ACROSS THE WEST AS ELEVATED RADAR RETURNS
ARE DIMINISHING. THIS TREND IS EXPECTED TO CONTINUE THROUGH THE
EVENING...LEAVING LIGHT TO SOMETIMES MODERATE SHOWERS THROUGH THE
NIGHT. ADDITIONALLY...DEEPER MOISTURE ASSOCIATED WITH A DEPARTING
MID-LEVEL TROUGH WILL CONTINUE TO DIMINISH THROUGH THE NIGHT. GIVEN
RECENT RADAR TRENDS AND HIGH-RES GUIDANCE...FEEL COMFORTABLE LETTING
ALL WESTERN LES ADVISORIES EXPIRE AT 00Z. HOWEVER...AS LOW-LEVEL
FLOW BEGINS TO BACK IN RESPONSE TO A SFC HIGH PASSING SW OF THE
REGION...EXPECT LAKE EFFECT BANDS TO FOCUS ACROSS THE KEWEENAW
OVERNIGHT. ANY ENHANCED CONVERGENT AREAS SHOULD BE RATHER TRANSIENT
WITH THE GRADUALLY BACKING WINDS...SO DO NOT THINK ANY STRONGER
BANDS WILL REMAIN IN ONE PLACE FOR TOO LONG. WITH THAT SAID...AN
ADDITIONAL 1 TO 3 INCHES WILL BE POSSIBLE DURING THE OVERNIGHT HOURS.

ACROSS THE EAST...CONVECTIVE CLOUDS DEPTHS OF 8-10 KFT ENCOMPASSING
THE DGZ COMBINED WITH LONGER FETCH WILL ALLOW FOR MODERATE TO
SOMETIMES HEAVY LAKE EFFECT BANDS TO PERSIST ACROSS THE WARNED AREA
OVER AND EAST OF MUNISING THROUGH THIS EVENING. THE BANDS ARE
BEGINNING TO SHIFT EASTWARD LATE THIS AFTERNOON AS LOW-LEVEL FLOW
BACKS SLIGHTLY. HOWEVER...A WEAK SFC TROUGH NOTED IN THE SFC WIND
FIELD OVER NE LAKE SUPERIOR AND ON SHORT-TERM MODEL GUIDANCE WILL
PUSH ACROSS THE EASTERN CWA LATE THIS EVENING INTO THE OVERNIGHT
HOURS. VEERING WINDS BEHIND THE TROUGH SHOULD PUSH THE LES BANDS
BACK WESTWARD TO AT LEAST MUNISING. WITH A LAND-BREEZE-ENHANCED
WESTERLY GRADIENT FLOW DEVELOPING OVER THE CENTRAL CWA AND AN
EASTERLY LAND BREEZE DEVELOPING OVER ONTARIO TONIGHT...AN AREA OF
STRONGER CONVERGENCE MAY FOCUS A MORE ROBUST LES BAND OVER EASTERN
ALGER COUNTY LATE TONIGHT. BY SUNRISE...INVERSION HEIGHTS BEGIN A
QUICK DESCENT TO UNDER 5KFT. WITH THE BACKING WINDS...THIS WILL PUSH
ALL OF THE LES OVER LAKE SUPERIOR BY LATE MORNING.

SOME CLEARING SKIES TONIGHT ALONG WITH DECREASING WINDS ASSOCIATED
WITH THE SFC RIDGE TO THE SW WILL ALLOW FOR GOOD RADIATIONAL COOLING
TONIGHT FOR WESTERN AND CENTRAL UPPER MI. WENT LOWER THAN MOST
GUIDANCE...BELOW ZERO...FOR MUCH OF THE INTERIOR. GIVEN TEMPS OF 0
TO -10F THIS MORNING UNDER THE SAME AIRMASS...AND THE START OF WAA
OUT WEST...DID NOT WANT TO GO TOO MUCH COLDER.

NOT MUCH TO BE SAID FOR FRIDAY AS WAA BEGINS ACROSS THE CWA. OTHER
THAN SOME MID TO HIGH CLOUD-COVER FILTERING OVER THE REGION IN THE
AFTERNOON...SKIES SHOULD BE MOSTLY SUNNY. SW WINDS WILL GRADUALLY
INCREASE THROUGH THE AFTERNOON...ESPECIALLY WEST...SO SOME BLOWING
SNOW WILL BE POSSIBLE.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 456 PM EST THU NOV 20 2014

BIG CHANGES ARE STILL EXPECTED DURING THE LONG TERM PORTION OF THE
FCST. HIGHLY AMPLIFIED PATTERN THAT HAS BROUGHT PERSISTENTLY MUCH
BLO NORMAL TEMPS INTO THE UPPER GREAT LAKES WILL RELAX SIGNIFICANTLY
OVER THE NEXT COUPLE OF DAYS AS PACIFIC FLOW PLOWS INTO THE WRN
PORTION OF NAMERICA AND FORCES THE ERN TROF OUT. CHANGE OCCURS
QUICKLY AS 500MB HEIGHTS OVER UPPER MI RISE A TREMENDOUS 400+ METERS
FROM THIS MORNING TO FRI EVENING. SO...AFTER AN UNSEASONABLY LONG
STRETCH OF COLD WEATHER FOR NOV (RECORD BREAKING SUBFREEZING STREAK
AT NWS MQT FOR NOV AND ALSO 6 CONSECUTIVE DAYS OF RECORD LOW MAX
TEMPS)...A QUICK TRANSITION BACK TO NORMAL/ABOVE NORMAL TEMPS WILL
OCCUR THIS WEEKEND. THE PACIFIC FLOW SURGING INTO THE WRN CONUS WILL
CARVE OUT A SIGNIFICANT SRN STREAM TROF THIS WEEKEND WHICH WILL LEAD
TO A DEEP SFC LOW LIFTING FROM TX TO UPPER MI (PRES BOTTOMS OUT IN
THE 970S MB OVER THE UPPER LAKES). WITH THE SIGNIFICANT WARMING THAT
WILL BE OCCURRING...PCPN ASSOCIATED WITH THIS DEEP SYSTEM ON THE
FRONT SIDE WILL BE RAIN FOR THE FCST AREA WITH MDT PCPN AMOUNTS
EXPECTED. AS COLDER AIR WRAPS INTO THE AREA ON THE BACKSIDE...THERE
WILL BE A TRANSITION BACK TO SNOW ON MON WITH THE POTENTIAL FOR AT
LEAST MDT SNOW ACCUMULATIONS ON INTO TUE...MAINLY NEAR LAKE
SUPERIOR. AFTER THE WARMUP THIS WEEKEND...IT LOOKS LIKE A COLD
PATTERN WILL BECOME RE-ESTABLISHED NEXT WEEK AS HEIGHTS RISE AGAIN
OVER WRN NAMERICA/NE PACIFIC WHICH WILL ALLOW ARCTIC AIR TO SPILL S
TOWARD THE CONUS AGAIN. THE ECMWF FOR THE LAST SEVERAL RUNS HAS BEEN
FAIRLY CONSISTENT SHOWING THE COLDEST AIR OF THE SEASON DROPPING SE
TOWARD THE CONUS NEXT WEEK...AND FOR WHAT IT`S WORTH...TODAYS 12Z
RUN HAS A LARGE MASS OF UNSEASONABLY COLD AIR DUMPING INTO THE GREAT
LAKES NEXT WEEKEND. WHETHER THIS IS A PATTERN THAT WILL AGAIN BECOME
PERSISTENT LIKE WHAT HAS OCCURRED RECENTLY IS HIGHLY UNCERTAIN AS
GEM ENSEMBLES AND CFSV2 RUNS CONTINUE TO SHOW A LOT OF FLUCTUATION
FARTHER OUT. HOWEVER...IT DOES APPEAR THAT COLDER THAN NORMAL
CONDITIONS WILL LIKELY BE MUCH MORE COMMON THAN ABOVE NORMAL OUT TO
2 WEEKS OR SO.

BEGINNING FRI NIGHT/SAT...WITH INCREASING ISENTROPIC ASCENT IN
STRENGTHENING WSW FLOW BTWN HIGH PRES MOVING OFF THE E COAST AND LOW
PRES MOVING ACROSS SCNTRL CANADA...MODELS ARE GENERATING SOME VERY
LIGHT PCPN OVER PARTS OF THE FCST AREA...MAINLY LATE FRI NIGHT INTO
SAT AFTN OVER THE ERN FCST AREA WHERE LONGER DURATION OF ISENTROPIC
ASCENT OCCURS. HOWEVER...PERSISTENCE OF DRIER AIR IN THE 850-700MB
LAYER SHOWN ON THE 12Z GFS/NAM FCST SOUNDINGS EVEN OVER THE E
WARRANTS JUST SCHC POPS FRI NIGHT...CHC POPS ONLY FOR THE E SAT
MORNING...AND NOTHING MORE THAN SCHC POPS ELSEWHERE SAT. WITH TODAYS
12Z GFS/NAM...FCST SOUNDINGS SHOW MORE OF A DISCONNECT OF MOISTURE
WITH MID LEVEL MOISTENING PRECEEDING LOW-LEVEL MOISTENING...AND THEN
MID LEVEL MOISTURE EXITING ONCE LOW LEVELS MOISTEN. SINCE THE
MOISTENING ENDS UP LOW BASED AND SFC BASED MOIST LAYER WILL BE
WARMER THAN -10C...PCPN MAY END UP MOSTLY AS -DZ/-FZDZ IF ANY PCPN
DOES OCCUR. EXPECT A RELATIVELY MODEST DIURNAL TEMP DROP FRI NIGHT
WITH MINS OCCURRING IN THE EVENING. TEMPS SHOULD THEN RISE SLOWLY
THRU MUCH OF THE NIGHT UNDER INCREASING SSW WINDS AND CLOUDS. TEMPS
ON SAT WILL RISE ABOVE FREEZING EVERYWHERE.

SAT NIGHT...WEAK HEIGHT RISES AND WEAKENING OF ISENTROPIC ASCENT
SUGGEST A DRY NIGHT IS PROBABLY IN THE OFFING. WITH LIGHTER WINDS
UNDER DRIER MID LEVELS...MIN TEMPS SHOULD FALL INTO THE 20S TO
AROUND 30F IN GENERAL.

MODELS CONTINUE TO INDICATE LOW PRES DEVELOPING OVER THE SRN PLAINS
SAT NIGHT/SUN MORNING IN ASSOCIATION WITH A STRONG SRN STREAM
SHORTWAVE. MEANWHILE...ADDITIONAL ENERGY MOVING OUT OVER THE PLAINS
WILL PULL THIS SYSTEM N WITH SFC LOW BECOMING DEEP INTO THE 970S MB
BY THE TIME IT REACHES THE UPPER LAKES MON MORNING. THERE CONTINUE
TO BE SOME CONCERNS WITH INTERACTION OF THE MAIN SHORTWAVE LIFTING
UP FROM TX AND UPSTREAM ENERGY MOVING INTO THE PLAINS. LATEST MODEL
TRENDS HAVE BEEN TO SHIFT SFC LOW TRACK SLIGHTLY E FROM CNTRL UPPER
MI TOWARD ERN UPPER MI. HOWEVER...LACK OF A COLD AIR TAP...HELD UP
BY THE ENERGY MOVING INTO THE PLAINS...STILL SUGGESTS PCPN ON THE
FRONT SIDE OF THIS SYSTEM WILL BE ALL RAIN FOR UPPER MI. THIS IS
BEST SHOWN BY THE ECMWF. HOWEVER...NOT OUT OF THE QUESTION THAT
THERE COULD BE A LITTLE -FZRA AT THE ONSET SUN IF TEMPS ARE STILL
CLOSE TO FREEZING WHEN PCPN BEGINS. OTHERWISE...MODEL TIMING IS GOOD
THAT RAIN WILL SURGE N INTO UPPER MI LATE SUN MORNING/AFTN AND
CONTINUE SUN NIGHT. EXPECT AT LEAST MDT RAINFALL AMOUNTS...ROUGHLY
AROUND ONE-HALF INCH IN GENERAL. HIGHER RAINFALL AMOUNTS WOULD BE
MORE LIKELY TO OCCUR OVER THE E WHERE MOISTURE TRANSPORT WILL BE
STRONGER/MORE SUSTAINED. AS THE SYSTEM THEN DRIFTS NE AND COLUMN
COOLS UNDER FALLING HEIGHTS...INCREASINGLY DEFINED DEFORMATION PCPN
SHIELD WILL DEVELOP INTO AT LEAST WRN UPPER MI. WITH 850MB TEMPS
COOLING SUFFICIENTLY...LAKE ENHANCEMENT WILL ALSO COME INTO PLAY. SO
AFTER THE RAIN...MAY END UP WITH MDT TO POTENTIALLY HVY SNOW OVER
WRN UPPER MI MON AFTN INTO MON NIGHT ALONG WITH BLUSTERY NW WINDS.
THE SNOW/WIND WILL SPREAD INTO THE ERN FCST AREA AS WELL...BUT WITH
DEFORMATION PCPN TENDING TO LIFT NE...SNOWFALL WILL LIKELY BE
LIGHTER THAN OVER THE W.

WITH 850MB TEMPS AROUND -14C TUE...NW FLOW LAKE ENHANCEMENT WILL
TRANSITION TO PURE LES AS TROF SHIFTS E AND DEEP MOISTURE DEPARTS.
THUS...THERE WILL BE A DIMINISHING OF SNOW THRU THE DAY NEAR THE
LAKE.

HEADING INTO WED/THU...THERE CONTINUES TO BE INDICATIONS OF A
CLIPPER TYPE SHORTWAVE BRINGING A POTENTIAL PERIOD OF -SN...FOLLOWED
BY A SURGE OF COLDER AIR AND RENEWED LES. GIVEN INCONSISTENCY IN
TIMING/LOCATION IN RECENT GFS/ECMWF MODEL RUNS...UTILIZED A
CONSENSUS APPROACH WHICH KEEPS POPS HIGHEST NEAR LAKE SUPERIOR.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1243 PM EST THU NOV 20 2014

LAKE EFFECT SNOW WILL CONTINUE FOR ALL SITES...ESPECIALLY
IWD...THROUGH THE REMAINDER OF THE AFTERNOON. VISIBILITIES WILL BE
QUITE VARIABLE FOR CMX AND IWD THROUGH 00Z...WITH IFR VIS PREVALENT.
SOME STRONGER -SHSN BANDS HAVE FOCUSED AROUND IWD EARLY THIS
AFTERNOON...SO VIS MAY BRIEFLY FALL TO LANDING MINS OVER THE NEXT
FEW HOURS. BACKING WINDS THIS EVENING WILL THEN END THE LAKE EFFECT
FOR IWD AND SAW. CMX SHOULD SEE CONTINUING -SHSN THROUGH MUCH OF THE
NIGHT UNTIL THE WINDS BACK MORE TO THE SW FRIDAY MORNING.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 PM EST THU NOV 20 2014

NW WINDS OF 20 TO 30 KNOTS ACROSS THE EASTERN LAKE WILL GIVE WAY TO
WEST WINDS OF 15 TO 25 KNOTS ACROSS MUCH OF LAKE SUPERIOR TONIGHT AS
A SURFACE RIDGE PASSES SW OF THE AREA. THEN...AS LOW PRESSURE BUILDS
OVER SOUTH-CENTRAL CANADA ON FRIDAY...EXPECT INCREASING SW FLOW
THROUGHOUT THE DAY. SW WINDS OF 20-30 KNOTS WILL BE COMMON FRIDAY
NIGHT...WITH SOME GALES TO 35 KNOTS POSSIBLE ACROSS MAINLY THE
WESTERN LAKE. LAKE STABILITY MAY KEEP OVERALL WINDS BELOW GALES
EXCEPT FOR THE HIGH PLATFORMS. THESE WINDS WILL QUICKLY DIMINISH TO
UNDER 20 KNOTS BY SATURDAY EVENING. THEN...AS TWO LOW PRESSURE
SYSTEMS DEVELOPING OVER THE NORTHERN PLAINS AND GULF COAST MERGE
OVER THE UPPER GREAT LAKES SUNDAY NIGHT INTO MONDAY...EXPECT A ROUND
OF N TO NW GALES.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  LAKE EFFECT SNOW WARNING UNTIL 10 AM EST FRIDAY FOR MIZ006-007-
     085.

  LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING
     FOR MIZ001>003-009.

LAKE SUPERIOR...
  GALE WATCH FROM FRIDAY EVENING THROUGH SATURDAY MORNING FOR
     LSZ263-264.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KLUBER
LONG TERM...ROLFSON
AVIATION...KLUBER
MARINE...KLUBER






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