Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 160925
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
525 AM EDT WED APR 16 2014

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 531 PM EDT TUE APR 15 2014

BIGGEST FORECAST CONCERNS FOR SHORT TERM FOCUS ON WINTER STORM
HEADLINES STARTING WEDNESDAY AND CONTINUING INTO THURSDAY.

WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
HUDSON BAY THROUGH THE CENTRAL GREAT LAKES INTO THE GULF COAST
STATES. INSTABILITY ASSOC WITH THIS TROUGH HAS SUPPORTED SOME
DIURNAL -SHSN ACROSS INLAND AREAS THIS AFTERNOON. THE SHORTWAVE
MOVING IN OFF THE PAC NW WILL BE THE FEATURE OF INTEREST IN THE
SHORT TERM AS IT DEVELOPS A DEEPENING STORM SYSTEM OVER THE NRN
PLAINS LATE TONIGHT AND BRINGS IT TOWARD THE WRN GREAT LAKES LATE
WED INTO WED NIGHT.

TONIGHT...ANY LEFTOVER DIURNAL SHSN OVER S CNTRL UPPER MI WILL
DIMINISH EARLY THIS EVENING AS PARTLY CLOUDY SKIES AND LIGHT WINDS
ALLOW TEMPS TO FALL INTO THE LOW SINGLE DIGITS OVER TYPICAL COLD
SPOTS FAR EAST TO 15 TO 20F RANGE FOR DOWNSLOPING AREAS ALONG LAKE
SUPERIOR FAR WEST AND AREAS CLOSE TO BAY OF GREEN BAY. TEMPS MAY
CLIMB LATE AS CLOUDS INCREASE AHEAD OF THE APPROACHING LOW PRESSURE
SYSTEM. WAA LIGHT SNOW WITH INCREASING 280K-290K ISENTROPIC LIFT IS
EXPECTED TO REMAIN MAINLY WEST OF UPPER MI BUT MAY SLIDE INTO THE
FAR WEST LATE.

WEDNESDAY...MODELS GENERALLY IN AGREEMENT SHOWING SHORTWAVE OF
INTEREST AND ASSOC DEEPENING SFC LOW OVER SE SOUTH DAKOTA AROUND 12Z
THEN DIFFER ON HOW QUICKLY THEY LIFT THIS LOW ENE TOWARD THE UPPER
GREAT LAKES. MOST OF 12Z MODELS GENERALLY TRENDING SLIGHTLY SLOWER
AND FARTHER SE THAN 06Z RUNS WITH TRACK OF SFC LOW. MODELS INDICATE
WARM AIR ADVECTION AND ISENTROPIC ASCENT ALONG AND AHEAD OF THE LOW
AND INVERTED SFC TROUGH SHOULD SUPPORT EXPANDING SNOW SHIELD FM
CNTRL MINNESOTA INTO NORTHWEST WI LATE TONIGHT THROUGH DAYBREAK ON
WEDNESDAY. THIS SNOW SHIELD WILL THEN SPREAD INTO WEST AND CENTRAL
UPPER MI DURING THE DAY ON WEDNESDAY. AS SFC TROUGH EDGES CLOSER TO
UPR MICHIGAN WED AFTN ISENTROPIC ASCENT BECOMES MAXIMIZED ON
285-290K SFCS ACROSS UPR MICHIGAN FROM 15Z INTO WED EVENING. GFS
REMAINS QUICKEST OF 12Z MODELS WHILE THE ECMWF IS THE SLOWEST. THE
NAM AND REGIONAL GEM FALL SOMEWHERE BTWN THESE SOLNS. H7 MIXING
RATIOS IN 2.5-3 G/KG RANGE SUGGESTS 12 HOUR SNOW AMOUNTS 4-6 INCHES
OVER MAINLY THE WEST HALF COUNTIES. IT/S POSSIBLE ACTUAL SNOW
AMOUNTS ON WED COULD BE HELD DOWN SOME AS SNOW ARRIVES DURING THE
DAYTIME WHEN INSOLATION COULD LIMIT ACCUMS ESPECIALLY ON HIGHER
TRAFFIC/TRAVELLED ROADS. CROSS SECTIONS SUGGEST POSSIBILITY OF
HEAVIER BANDED SNOWFALL OVER WESTERN COUNTIES WITH NEG EPV ABOVE
FAIRLY STRONG 7H FGEN FORCING SO THIS COULD ADD A FEW INCHES TO THE
4-6 INCH TOTALS RENDERED SOLELY FM ISENTROPIC ASCENT.

WITH ALL ABOVE FACTORS TAKEN INTO CONSIDERATION...HAVE DECIDED TO
UPGRADE WATCHES OVER THE WEST HALF COUNTIES TO WARNINGS FROM
MQT-DICKINSON WESTWARD. GENERALLY STARTED WARNINGS ON WED FM 14Z
SOUTH TO 16Z NORTH. ALSO MOVED THE AXIS OF HEAVIER PCPN/SNOWFALL
SLIGHTLY FARTHER EASTWARD BASED ON 12Z MODEL TRENDS WITH SNOWFALL
AMOUNTS ON WED RANGING FM 3 TO 5 INCHES OVER THE NW CWA TO 4-7
INCHES OVER THE FAR SW CWA ALONG THE WI BDR. WENT WITH ADVISORIES
FOR MNM...DELTA AND ALGER COUNTIES WHERE 2-4 INCH AMOUNTS WILL BE
MORE COMMON ON WED WITH MUCH OF THE SNOW FALLING IN THE AFTERNOON
HRS. FARTHER EAST OVER SCHOOLCRAFT AND LUCE COUNTIES...LOW-LVL DRY
AIRMASS INITIALLY IN PLACE FROM LINGERING SFC RDG AXIS WILL TAKE A
BIT LONGER TO MOISTEN FM ISENTROPIC ASCENT SO ONLY EXPECT GENERALLY
1-2 INCHES OF SNOW THERE AND WILL HOLD OFF ON ANY HEADLINE THERE FOR
NOW. IF TONIGHT/S MODEL RUNS CONTINUE TO TREND EASTWARD MAY NEED TO
CONSIDER POSSIBILITY OF ADDING MNM AND POSSIBLY DELTA INTO
WARNING.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 514 AM EDT WED APR 16 2014

THURSDAY...WITH THE SLOWER MODEL TREND...THE SHORTWAVE OVER NRN WI
AND ASSOCIATED 700-500 QVECTOR CONV AND 290K-295 ISENTROPIC LIFT
WILL CONTINUE TO SUPPORT MODERATE SNOW IN THE MORNING...WITH
ADDITIONAL ACCUMULATIONS IN THE 1 TO 3 INCH RANGE...GREATEST OVER
THE NW HALF. THE STRONGER DYNAMICS AND PCPN WILL QUICKLY LIFT TO THE
NORTHEAST BY AFTERNOON WITH LITTLE ADDITIONAL SNOW. THERE MAY ALSO
BE A MIX OF LIGHT RAIN OVER THE SOUTH AND EAST PORTIONS OF THE CWA.

THURSDAY NIGHT...MOIST LOW LEVEL CYCLONIC FLOW BEHIND THE DEPARTING
LOW WILL RESULT IN MOSTLY CLOUDY SKIES AND SHOULD KEEP MIN TEMPS IN
THE LOW TO MID 20S.

FRIDAY...IF CLOUDS DO CLEAR OUT IN SOME AREAS THU NIGHT...EXPECT BKN
DIURNAL CU DEVELOPMENT FRI UNDER THE MID LEVEL TROF AND ASSOCIATED
THERMAL TROF WITH 850/700 MB TEMPS AROUND -10C/-15C. ALTHOUGH THE
STEEP LOW LEVEL LAPSE RATES COULD SUPPORT SOME FLURRIES...NO
ACCUMULATION IS EXPECTED. FRI HIGHS WILL BE IN THE 30S NORTH WITH A
COLD WIND OFF THE ICE TO THE 40S S. WITH CLOUDS CLEARING OUT FRI
NIGHT...IT WILL BE A COLD NIGHT WITH HIGH PRES STILL OVER THE AREA.
FAVORED THE LOWER SIDE OF GUIDANCE WITH SOME TEENS OVER THE W WHERE
WINDS WILL BE LIGHTEST. COULD BE CONSIDERABLY COLDER ACROSS ALL OF
THE INTERIOR IF SKIES CLEAR EARLY AND STAY THAT WAY FOR A GOOD PART
OF THE NIGHT.

SAT INTO SUN...A SHORTWAVE TROUGH OVER THE PAC NW THU WILL REACH NRN
ONTARIO SAT NIGHT INTO SUN. THE GEM AND ECMWF REMAINED MORE
PROGRESSIVE AND STRONGER WITH THE NRN PORTION OF THE
SHRTWV...DRAGGING THE FRONTAL SYSTEM THROUGH UPPER MI FASTER THAN
THE GFS. LOW LEVEL TEMPS WILL BE WARM ENOUGH FOR MAINLY RAIN. EXPECT
THE GREATEST RAIN CHANCE SAT NIGHT WITH SOME CLEARING POSSIBLE SUN
AS DRIER AIR MOVES IN FROM THE WEST. TEMPERATURES SHOULD CLIMB BACK
INTO THE LOWER TO MID 40S BY SUN AFTERNOON.

MON/TUE...THE MODELS SUGGEST THAT THE PATTERN WILL AMPLIFY AS A
TROUGH DIGS INTO THE WEST COAST. AS A RESULT THE NRN LAKES WILL BE
ON THE EDGE OF THE WARMER AIR AS A RIDGE BUILDS OVER THE PLAINS.
TEMPS SHOULD CLIMB BACK TO NEAR NORMAL WITH HIGHS IN THE UPPER 40S
AND LOWER 50S WITH MIN READINGS IN THE LOWER 30S. SOME LIGHT RAIN
MAY BE POSSIBLE WITH ANY WEAK SHRTWVS EMBEDDED IN THE WNW FLOW
THROUGH THE REGION. HOWEVER...ANY AMOUNTS WOULD BE VERY LIGHT.
SO...ONLY SLIGHT CHANCE POPS SEEM ON TRACK.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 133 AM EDT WED APR 16 2014

LIGHT WINDS WILL PERSIST THROUGH THE NIGHT AS HIGH PRESSURE MOVES
THROUGH THE REGION. THEN AN APPROACHING STORM SYSTEM WILL BRING
INCREASING CLOUDS AND SNOW TO THE AREA. KIWD WILL SEE THE IMPACTS
FIRST...WITH IFR VSBYS DEVELOPING THERE BY MIDDAY IN LIGHT TO
MODERATE SNOW. THE SNOW WILL THEN SPREAD TO KCMX AND KSAW THROUGH
THE REMAINDER OF THE DAY. CIGS TO LOWER DURING THE DAY WITH IFR
CONDITIONS DEVELOPING AS THE SYSTEM CLOSES IN ON THE AREA AND
PERSISTING THROUGH THE END OF THE FORECAST.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 524 AM EDT WED APR 16 2014

AN APPROACHING LOW PRESSURE SYSTEM FROM THE PLAINS WILL RESULT IN
INCREASING EAST TO NORTHEAST WINDS TODAY WITH GALES FOR FAR WRN LAKE
SUPERIOR THIS AFTERNOON INTO THU MORNING MORNING AS WINDS ARE
ENHANCED DUE TO CHANNELING AND TERRAIN EFFECTS. WINDS SHIFT TO THE
NORTH-NORTHWEST TO 25 KTS BY THURSDAY AFTERNOON AS THE LOW WEAKENS
WHILE MOVING OVER ERN LK SUPERIOR. EXPECT WINDS STAY BLO 20 KTS FOR
THE REST OF THE FORECAST PERIOD.
&&

.HYDROLOGY...
ISSUED AT 531 PM EDT TUE APR 15 2014

RECENT COLDER WEATHER AND CONTINUATION OF COLDER WEATHER FOR THE
NEXT FEW DAYS WILL RESULT IN SLOW RUNOFF OF MELTING SNOW. THUS...
RIVER LEVELS SHOULD NOT SHOW ANY SIGNIFICANT FLUCTUATIONS.
HOWEVER...ICE JAMS COULD BE AN ISSUE AS THEY HAVE BEEN IN SOME
AREAS. HOWEVER...DIMINISHED RUNOFF SHOULD REDUCE THE POTENTIAL FOR
ADDITIONAL ICE JAMS. WIDESPREAD PRECIPITATION IS IN THE FORECAST FOR
WEDNESDAY THROUGH THURSDAY MORNING WITH THE POTENTIAL FOR 0.50 TO
1.25 INCHES OF LIQUID EQUIVALENT PRECIPITATION...GREATEST OVER THE W
HALF OF UPPER MICHIGAN. THIS PRECIP ADDED TO EXISTING SNOWPACK WITH
WATER EQUIVALENT OF 4-9 INCHES WILL RESULT IN ANOTHER PERIOD OF
SNOWMELT RUNOFF/RIVER RISES AND POSSIBLE ICE JAMS ONCE WARMER
TEMPERATURES ARRIVE NEXT WEEK.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO NOON EDT
     THURSDAY FOR MIZ006-013.

  WINTER STORM WARNING FROM NOON TODAY TO 11 AM EDT THURSDAY FOR
     MIZ004-084.

  WINTER STORM WARNING FROM NOON TODAY TO NOON EDT THURSDAY FOR
     MIZ005.

  WINTER STORM WARNING FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO
     11 AM EDT /10 AM CDT/ THURSDAY FOR MIZ002-009>011.

  WINTER STORM WARNING FROM 2 PM THIS AFTERNOON TO NOON EDT
     THURSDAY FOR MIZ001-003.

  WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO 10 AM CDT
     THURSDAY FOR MIZ012.

LAKE SUPERIOR...
  GALE WARNING FROM 6 PM EDT /5 PM CDT/ THIS EVENING TO 6 AM EDT
     /5 AM CDT/ THURSDAY FOR LSZ162.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...VOSS
LONG TERM...JLB
AVIATION...RJT
MARINE...JLB
HYDROLOGY...ROLFSON






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