Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 222121
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
421 PM EST SAT NOV 22 2014

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 420 PM EST SAT NOV 22 2014

WV IMAGERY AND RUC ANALYSIS INDICATED ZONAL FLOW ACROSS THE NRN
CONUS WITH A STRONG 170 KNOT 250 MB JET MOVING INTO THE PAC NW. A
SHORTWAVE TROUGH WAS MOVING THROUGH SRN SASK AND NRN MT. A VIGOROUS
SRN SHORTWAVE TROUGH WAS LOCATED OVER WRN TEXAS. AT THE SFC...SRLY
FLOW PREVAILED FROM THE GULF TOWARD THE UPPER MS VALLEY AND NRN
LAKES BTWN HIGH PRES OVER THE MID ATLANTIC AND A 984 MB LOW INTO SRN
SASK. WAA HAS PUSHED TEMPS INTO THE MID AND UPPER 30S ACROSS UPPER
MI. ALTHOUGH THE LOW LEVEL MOISTURE THINNED OUT ENOUGH FOR SOME
SUNSHINE THIS AFTERNOON...ESPECIALLY IN DOWNSLOPE LOCATIONS...CLOUDS
OVER NRN WI AND WRN UPPER MI WERE FILLING IN AGAIN ACROSS THE AREA.

TONIGHT...ANY LINGERING DRY LOW LEVEL AIR WILL FILL IN TONIGHT WITH
STRONG LOW LEVEL MOISTURE ADVECTION THIS EVENING. SO...EXPECT BETTER
CHANCES FOR PCPN AS DRIZZLE OR POSSIBLY FREEZING DRIZZLE AS A
SUBSTANTIAL DRY LAYER REMAINS ABOVE 900 MB. SOME FOG WILL BE POSSIBLE
AS WELL AS DEWPOINTS CLIMB TO AROUND FREEZING OR SLIGHTLY ABOVE BY
LATE TONIGHT. EXPECT THE BEST CHANCE FOR DRIZZLE OVER CNTRL UPPER MI
WITH AN UPSLOPE LOW LEVEL WIND COMPONENT SUPPORT...AND OVER THE EAST
CWA WITH ADDED MOISTURE OFF OF LAKE MICHIGAN. TEMPS MAY DROP OFF TO
NEAR FREEZING THIS EVENING AND SLOWLY CLIMB OVERNIGHT.
HOWEVER...SINCE MANY ROAD SURFACES MAY STILL BE BELOW FREEZING...ANY
DRIZZLE THAT FALLS COULD CREATE ICY/SLIPPERY CONDITIONS ON UNTREATED
ROADS.

SUN...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
THE STRONG MOISTURE ADVECTION CONTINUES AND 850-700 MB FGEN
INCREASES. THE GREATEST CHANCE IS EXPECTED OVER THE EAST IN
PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS THE DRY
LAYER FILLS IN ANY DRIZZLE WILL CHANGE OVER TO RAIN BY MID TO LATE
AFTERNOON. TEMPS WILL CLIMB ABOVE NORMAL INTO THE LOW TO MID 40S.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 559 AM EST SAT NOV 22 2014

A VERY ACTIVE WEEK IS IN STORE ACROSS THE UPPER GREAT LAKES AS A
POTENT PACIFIC SHORTWAVE DIGS SE AND CARVES OUT A MID-LVL TROUGH
OVER THE PLAINS. THIS WILL BRING A DECENT SURGE OF WARM AIR ACROSS
THE AREA THIS WEEKEND...RESULTING IN ABOVE-AVERAGE TEMPERATURES FOR
A SHORT PERIOD. FORCING AHEAD OF THE ASSOCIATED SFC LOW PRESSURE
SYSTEM WILL ALSO BRING A BATCH OF MODERATE RAIN ACROSS MAINLY
CENTRAL AND EASTERN UPPER MI SUNDAY NIGHT INTO MONDAY. A QUICK
TRANSITION BACK TO WINTER WILL THEN TAKE PLACE ON MONDAY INTO MONDAY
NIGHT AS THE TROUGH AND ASSOCIATED STRONG SURFACE LOW MOVE NORTHEAST
OF THE REGION...BRINGING STRONG CAA AND THE POTENTIAL FOR A MODERATE
TO HEAVY SNOWFALL ACROSS THE WESTERN CWA.

SUN INTO SUNDAY NIGHT...MODELS CONTINUE TO INDICATE LOW PRES RAPIDLY
DEVELOPING OVER THE SRN PLAINS LATE TONIGHT AND SUN IN RESPONSE TO
THE STRONG PACIFIC SHORTWAVE DIGGING INTO THE BASE OF THE SRN STREAM
TROUGH. MEANWHILE...ADDITIONAL ENERGY MOVING OUT OVER THE NRN PLAINS
WILL HELP PULL THIS SYSTEM NORTH AND WITH THE SUBSEQUENT PHASING THE
SFC LOW IS EXPECTED TO RAPIDLY DEEPEN BASICALLY BOMBING OUT INTO THE
970S MB BY THE TIME IT REACHES THE UPPER LAKES MON MORNING. THE
GFS/GEM-NH AND ECMWF ARE NOW ALL IN FAIRLY AGREEMENT SHOWING A SFC
LOW TRACK TOWARD THE MACKINAC STRAITS BY MON MORNING. THE 00Z RUNS
OF THE GEM-NH AND GFS SHOW A DEEPER LOW (IN THE LOW 970S) WHILE THE
ECMWF SHOWS A LOW PRES CENTER IN HIGH 970S. ALL MODELS SUGGEST THAT
PCPN ON THE FRONT SIDE OF THIS SYSTEM WILL BE ALL RAIN FOR UPPER MI
SUNDAY AFTERNOON INTO SUNDAY NIGHT. PCPN WILL LIKELY BE MORE IN THE
FORM OF DRIZZLE SUN MORNING AS SFC-BASED MOIST LAYER STAYS ABOVE
FREEZING WITH DRY AIR ALOFT IN THE DGZ REGION. MODELS FAIRLY
CONSISTENT SHOWING BEST SURGE OF RAIN INTO UPPER MI LATE SUNDAY INTO
SUN NIGHT. COUPLED UPPER JET STRUCTURE SUPPORTING THE RAPID
DEEPENING OF THE SFC LOW AND DEEP LAYER Q-VECT CONVERGENCE WILL
SUPPORT WIDESPREAD RAIN ACROSS THE CWA ON SUNDAY NIGHT. LOOK FOR THE
GREATEST PCPN...PERHAPS MORE THAN ONE INCH...TO OCCUR OVER THE ERN
COUNTIES WHERE THE BEST 850-700 MB MOISTURE TRANSPORT IS EXPECTED
CLOSER TO THE TRACK OF THE SFC LOW.

MON INTO MON NIGHT...AS THE SYSTEM LIFTS NNE AND THE COLUMN COOLS
UNDER FALLING HEIGHTS...MODELS INDICATE DEFORMATION/COMMA HEAD PCPN
SHIELD DEVELOPING. THE FCST CHALLENGE WILL BE DETERMINING THE
STRENGTH AND PERSISTENCE OF THIS DEFORMATION PCPN SHIELD AND WHERE
IT WILL SET UP. 00Z MODELS NOW HINTING THAT BEST DEFORMATION/MOST
PERSISTENT 700 MB FGEN FORCING WILL BE OVER THE WRN COUNTIES WHERE
PCPN WILL BE CHANGING OVER TO SNOW MON MORNING. WITH 850MB TEMPS
COOLING TO AROUND -12C LATE MON...LAKE ENHANCEMENT WILL ALSO COME
INTO PLAY. STILL HAVE THE WRN CWA PEGGED FOR THE POTENTIAL OF
MODERATE TO POTENTIALLY HEAVY SNOW MON INTO MON NIGHT ALONG WITH
BLUSTERY NW WINDS DEVELOPING BEHIND THE SYSTEM AND WILL CONTINUE TO
HIGHLIGHT IN HWO AND EHWO GRIDS. WITH MODEL AVERAGED QPF OF .5-.7
AND SNOW/WATER RATIOS NEAR 10/1 MON MORNING RAISING TO 20/1 LATE MON
NIGHT...HAVE COME UP WITH 24 HR SNOW TOTALS OF 7-9 INCHES OVER SOME
HIGHER TERRAIN LOCATIONS OF WEST FROM KIWD UP TO KCMX. 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 FM -12C TO -14C TUE...NW FLOW LAKE ENHANCEMENT WILL
TRANSITION TO PURE LES AS TROF SHIFTS E AND DEEP MOISTURE DEPARTS.
WITH A TREND TOWARD MORE ANTICYCLONIC FLOW...THERE WILL BE A
DIMINISHING OF NW FLOW LES THRU THE DAY NEAR THE LAKE...BUT WILL
MAINTAIN LIKELY TO CATEGORICAL POPS AT LEAST FOR THE MORNING OVER
THESE AREAS.

HEADING INTO WED/THU...AFTER A BRIEF BREAK FROM THE SNOW TUE NIGHT
...IT LOOKS LIKE THERE MAY BE A POTENTIAL FOR SOME MORE SNOW WED
INTO THANKSGIVING AS MEDIUM RANGE MODELS SHOW INDICATIONS OF A
CLIPPER SHORTWAVE DIVING THROUGH THE MIDWEST/GREAT LAKES REGION.
GFS IS QUITE A BIT QUICKER THAN THE ECMWF/GEM-NH/UKMET WITH THIS
WAVE AND SEEMS TO BE AN OUTLIER AT THIS POINT. THE ECMWF SOLN SHOWS
A BIT DEEPER SYSTEM AND MORE PROLONGED TROFFING INTO THE UPPER GREAT
LAKES WHICH WOULD LIKELY YIELD MORE SNOW. WILL HIGHLIGHT IN EHWO
GRIDS AT LEAST A LIMITED POTENTIAL FOR MODERATE SNOW ALONG THE LAKE
SUPERIOR COUNTIES.

BOTH THE ECMWF AND GEM-NH SHOW RIDGING WORKING IN FROM THE WEST BY
NEXT FRIDAY WHICH SHOULD ALLOW FOR A DIMINISHING TREND TO LES FOR NW
FLOW AREAS ALONG LAKE SUPERIOR.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1244 PM EST SAT NOV 22 2014

LOW CLOUDS ARE THE MAIN FORECAST ISSUE INTO SUNDAY. ALTHOUGH THERE
WERE SOME BREAKS IN THE OVERECAST IN DOWNSLOPE AREAS IN CNTRL UPPER
MI EXPECT MVFR CIGS TO PERSIST AT THE TAF SITES THIS AFTERNOON.
CONTINUING MOISTURE FLOWING INTO THE AREA SHOULD RESULT IN LOWERING
OF CIGS TONIGHT. BASED ON UPSTREAM CIGS THIS MORNING OVER
IA/MN/WI...EXPECT CIGS TO FALL TO IFR LATE TONIGHT...OR EVEN
LIFR...AS THE MOIST LOW-LEVELS WILL BE ONLY BE ADDED TO BY
ADDITIONAL MOISTURE AND HELPED ALONG BY DEVELOPING UPSLOPE FLOW AT
KCMX AND KSAW. AT THESE SITES....PROBABLY WILL SEE DRIZZLE AND FOG
AS WELL WITH VSBY LIKELY REACHING IFR LATE TONIGHT.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 420 PM EST SAT NOV 22 2014

SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL MOVE
TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL INCREASE TO
GALES 40-45 KTS MONDAY AFTN INTO MONDAY NIGHT. WINDS DIMINISH TO 25
KTS OR LESS LATER TUESDAY INTO WEDNESDAY...THEN INCREASE TO 30 KTS
ON THURSDAY AS COLD AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE
BUILDING OVER THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE
LOWER GREAT LAKES.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
  GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
     LSZ248>250-265-266.

  GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
     LSZ242>245-263-264.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...JLB
MARINE...JLB






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