Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 231759
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1259 PM EST SUN NOV 23 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM EST SUN NOV 23 2014

MAIN FORECAST CONCERNS INCLUDE DENSE FOG THIS MORNING...TIMING THE
ONSET OF PCPN LATER TODAY AND THEN THE CHANGEOVER TO SNOW LATE
TONIGHT IN THE WEST.

WV IMAGERY AND RUC ANALYSIS SHOWS A VIGOROUS SRN STREAM SHORTWAVE
OFF THE TX GULF COAST WITH A STRONG SHORTWAVE AND ASSOC 150+ KNOT
250 MB JET MOVING OFF THE PAC NW INTO NRN NEVADA. ANOTHER SHORTWAVE
TROUGH WAS MOVING INTO WRN ND. AT THE SFC...SRLY FLOW PREVAILED FROM
THE GULF TOWARD THE UPPER MS VALLEY AND NRN GREAT LAKES REGION BTWN
HIGH PRES OVER THE MID ATLANTIC AND A 993 MB LOW OVER ND. WAA AND
LOW CLOUD COVER HAVE MAINTAINED TEMPS IN THE MID AND UPPER 30S
ACROSS UPPER MI EARLY THIS MORNING. THE WARM AIR MOVING OVER THE
MOSTLY SNOWPACKED GROUND HAS ALSO RESULTED IN DENSE FOG ACROSS MUCH
OF THE ERN TWO THIRDS OF UPPER MI THIS MORNING.

TODAY...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
STRONG MOISTURE ADVECTION/TRANSPORT CONTINUES AND 850-700 MB FGEN
INCREASES. EXPECT THE BETTER CHANCE FOR RAIN OVER THE SOUTH CENTRAL
AND EAST IN PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS
THE MID-LVL DRY LAYER MOISTENS UP ANY DRIZZLE SHOULD CHANGE OVER TO
RAIN BY MID TO LATE AFTERNOON. EXPECT TEMPS WILL CLIMB ABOVE NORMAL
INTO THE LOW TO MID 40S. WARM AIR MOVING OVER THE COLD SNOW PACK HAS
RESULTED IN DENSE FOG THIS MORNING SO HAVE POSTED A DENSE FOG
ADVISORY THROUGH 16Z FOR ALL BUT THE FAR FOUR WESTERN COUNTIES OF
THE CWA.

TONIGHT...CONTINUED INCREASE IN DEEP LAYER Q-VECT
CONVERGENCE...DEVELOPMENT OF COUPLED UPPER JET STRUCTURE AND
ENHANCED 850-700 MB FGEN WILL LEAD TO WIDESPREAD RAINFALL ACROSS
MUCH OF THE CWA BY EVENING. MODEL AVERAGED QPF RANGES FROM .25 WEST
TO .75 SOUTHEAST. MODEL SNDGS AND CRITICAL 1000-850 MB THICKNESSES
SUGGEST RAIN WILL BEGIN TO SWITCH OVER TO SNOW FAR WEST AROUND 09Z
BUT WITH SNOW/WATER RATIOS RISING TO ONLY AROUND 6-7/1 BY 12Z MON
EXPECT SNOW ACCUMULATION TO BE LESS THAN AN INCH FOR THE FAR WEST BY
12Z MONDAY. THERE IS POTENTIAL FOR FOG TO BE AN ISSUE WITH RAIN OVER
THE SNOWPACK SO THIS WILL BE SOMETHING TO WATCH LATER TODAY. TEMPS WILL
RANGE FM THE LOWER 30S WEST TO UPPER 30S EAST.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 558 AM EST SUN NOV 23 2014

COMPLEX DEEPENING LOW PRESSURE SYSTEM AND ASSOCIATED SNOW/BLSN
MONDAY AND MONDAY NIGHT IS MAIN ISSUE.

WV LOOP AND 00Z RAOBS SHOW SPLIT FLOW OVER THE CONUS. STRONG
SHORTWAVE NOTED IN NORTHERN STREAM IS CROSSING SASKATCHEWAN WITH
VIGOROUS PAIR OF SHORTWAVES IN THE SOUTHERN STREAM OVER THE SOUTHERN
PLAINS AND INTO EAST TX. AT DAYBREAK ON MONDAY...SHORTWAVE CURRENTLY
OVER KS WILL BE LIFTING TOWARD UPPER GREAT LAKES. ASSOCIATED SFC LOW
WILL BE IN PROCESS OF DEEPENING TO AROUND 980MB VCTY OF NORTHERN
LOWER MICHIGAN OR EASTERN UPR MICHIGAN. WIDESPREAD PRECIPITATION
SHOULD BE ONGOING DUE TO LIFT FM H7-H5 Q-VECTOR CONVERGENCE FM LEAD
SHORTWAVE...RIGHT ENTRANCE FORCING FM JET STREAK OVER NORTHERN
ONTARIO...AND H85-H7 MOISTURE ADVECTION WRAPPING AHEAD OF SFC-H85
LOW. SOUNDINGS SHOW COOLING BLO 900MB LEADING TO INITIAL CHANGEOVER
FROM RAIN TO SNOW OVER WESTERN THIRD OF CWA. EXPECTED RAIN/SNOW LINE
FOLLOWS 925MB TEMP OF 0C PRETTY WELL.

SNOW AMOUNTS ON MONDAY DEPEND ON EXTENT OF MOISTURE INGESTED INTO
THE SFC LOW...AND MORE SPECIFICALLY HOW MUCH OF THIS DEEP MOISTURE
IS ADVECTED FARTHER TO THE WEST OF THE SFC LOW BACK INTO THE COLD
AIR. AT THIS TIME...ONLY MODEL THAT IS REALLY EMPHATIC WITH STRONGER
AND SLOWER SFC LOW AND THUS MORE DEEP MOISTURE TO WORK WITH IS THE
00Z/06Z NAM. OTHER MODELS AND ENSEMBLES...INCLUDING THE 00Z GFS AND
ECMWF AND 21Z SREF...AND TO A LESSER DEGREE THE 00Z GEM...ARE MORE
PROGRESSIVE WITH THE LOW AND ULTIMATELY HAVE LESS DEEPER MOISTURE
AND SYNOPTIC QPF LINGERING INTO MONDAY AFTN. USING MORE MIDDLE OF
ROAD APPROACH AS DO NOT HAVE ENOUGH CONFIDENCE TO TREND TOWARD
WETTER NAM IDEA. LESSER QPF ALONG WITH SNOW-LIQUID RATIOS THAT
BARELY RISE ABOVE 10:1 MOST OF MONDAY...RESULTED IN SOLID ADVISORY
LEVEL SNOWS OF 2-4 INCHES OR MAYBE 3-5 INCHES...HEAVIEST OVER FAR
WESTERN CWA WHERE PTYPE IS SNOW FOR LONGEST DURATION. LESS THAN 1
INCH OF SNOW DURING THE DAYTIME FOR EAST WITH A LATER CHANGEOVER.

GOING WITH PREFERRED GFS/ECMWF IDEA FOR MONDAY NIGHT...SHORTWAVE
MOVING NORTHEAST OVER THE WESTERN GREAT LAKES IS CAUGHT UP SOME BY
ANOTHER SHORTWAVE LEFT OVER THE CURRENT TROUGH OVER SASKATCHEWAN.
SWATH OF MODERATE SNOW SHOULD RESULT...MAINLY OVER NORTH AND EAST
CWA. ENOUGH COLD AIR WORKING IN BY THAT TIME TO LEAD TO LAKE
ENHANCEMENT OFF LK SUPERIOR. SIGNAL STILL THERE THAT SECONDARY AREA
OF SYNOPTIC FORCING/LIFT LINKS UP WITH MOST IDEAL LAKE ENHANCEMENT
VCNTY OF NNW WIND SNOW BELTS OF ALGER/NORTHERN SCHOOLCRAFT COUNTIES.
LATEST 12 HR SNOW AMOUNTS ARE PUSHING WARNING CRITERIA OF 6 INCHES
FOR THESE AREAS. MODERATE SNOW ACCUMULATIONS WILL CONTINUE ALONG
MUCH OF LK SUPERIOR...BUT SNOW AMOUNTS SHOULD BE ON THE DECLINE
ALONG THE WI BORDER AS BETTER FORCING MISSES THAT AREA TO THE EAST.

FROM AT STRICTLY SNOW AMOUNT CRITERIA...EVENT LOOKS TO BE SOLID ADVY
MONDAY INTO MONDAY NIGHT. SNOW ON TUESDAY SHOULD BE ON THE WANE AS
EVEN THOUGH IT IS BECOMING COLDER FOR LAKE EFFECT...SUPPLEMENTAL
LARGER SCALE FORCING IS ON THE WANE. SOUNDINGS INDICATE LESSENING
CYCLONIC FLOW WILL REALLY PUT THE KABOSH ON LINGERING LAKE EFFECT ON
TUESDAY. ONE ASPECT OF THE SYSTEM THAT CANNOT BE DISCOUNTED THOUGH
IS THE WIND. SFC LOW DEEPENS AS IT LIFTS EAST OF LK SUPERIOR AND ON
TO THE NORTHEAST ON MONDAY NIGHT TRACKING TOWARD JAMES BAY. AT THE
PEAK...PRESSURE GRADIENT WEST TO EAST FROM DLH TO SSM IS 20 MB LATE
MONDAY AFTN INTO MONDAY EVENING. SOUNDINGS INDICATE 35+ KT WINDS
ABOVE H9 WITH 40+ KTS ABOVE H8. GIVEN THE DEGREE OF MIXING WITH THE
COLD AIR ADVECTION EXPECTED...SEEMS REASONABLE THAT MOST AREAS WILL
SEE GUSTS 30-40 MPH. BLOWING SNOW/POOR VSBY MAY BECOME PRETTY BIG
FACTOR OVER MUCH OF THE AREA WITH THE STRONG WINDS.

SINCE THIS EVENT SEEMS TO BE HEADING TOWARD MORE OF AN ADVY EVENT
INSTEAD OF A WARNING...DECIDED TO NOT ISSUE A WATCH AND INSTEAD
ISSUE ANOTHER SPECIAL WEATHER STATEMENT. DID EXPAND THE SPS TO
INCLUDE ALL OF THE CWA WITH THE POTENTIAL FOR MODERATE SNOW AND BLSN
OVER MUCH OF THE AREA.

REST OF THE WEEK COULD FEATURE HIGHER IMPACT WEATHER FOR THE TRAVEL
TIME AROUND THANKSGIVING AND THE HOLIDAY ITSELF. DETAILS FAR FROM
CERTAIN BUT AFTER A LULL FOR MOST AREAS ON TUESDAY NIGHT /MINS
POSSIBLY NEAR 0F OVER INTERIOR CNTRL CWA WITH ENOUGH CLEARING TUE
NIGHT/...ANOTHER PAIR OF SHORTWAVES ARE FORECAST TO SLIDE SOUTHEAST
OVER THE GREAT LAKES WEDNESDAY INTO WEDNESDAY NIGHT. GFS WEAKER THAN
THE ECMWF WITH THE SFC TROUGH AND THAT AFFECTS THE DEGREE OF
CYCLONIC FLOW AND LAKE ENHANCED SNOW THAT DEVELOPS AS THE SYSTEM
MOVES BY. ALSO COULD SEE MORE STRONG WINDS DUE TO TIGHTER PRESSURE
GRADIENT...ESPECIALLY NEAR LK SUPERIOR OVER THE WEST. HAVE LIKELY
POPS ALONG MOST OF THE NORTHERN PART OF CWA LATER WEDNESDAY INTO
WEDNESDAY NIGHT AND ALSO FOR THANKSGIVING NEAR LK SUPERIOR FOR
NNW-NW FLOW LAKE EFFECT. OVER-WATER INSTABILITY NON-ISSUE AS H85
TEMPS FALL BLO -15C WED NIGHT AND TREND TOWARD -20C ON THANKSGIVING.
TEMPS WILL STRUGGLE THROUGH THE TEENS ON THANKSGIVING MAKING IT MORE
LIKE LATE DECEMBER OR JANUARY. RECORD LOW MAX AT NWS MQT FOR 27
NOVEMBER IS 18 SET IN 1967. COULD BE CLOSE TO THAT MARK.

COLD AIRMASS WILL KEEP LAKE EFFECT GOING TO CLOSE THE WEEK...MAINLY
FOR WNW-WSW FLOW REGIMES...SO MOSTLY LOOKING AT KEWEENAW AND ALONG
LK SUPERIOR TO EAST OF MARQUETTE. IF THERE IS ANY MODERATION IN
TEMPS IT PROBABLY WILL NOT BE UNTIL LATE IN THE WEEKEND OR EVEN
EARLY NEXT WEEK.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1258 PM EST SUN NOV 23 2014

WITH LOW LEVEL MOIST/WARM ADVECTION CONTINUING INTO THE AREA
SHOULD...PERSISTENT LOW CIGS AND FOG WILL CONTINUE INTO TONIGHT.
VLIFR CONDITIONS BELOW LANDING MINS ARE LIKELY TO PERSIST THIS
AFTERNOON AT KSAW WITH THE UPSLOPE FLOW HELPING TO MAINTAIN THE
DENSE FOG. SOME IMPROVEMENT MAY BE POSSIBLE WHEN RAIN MOVES IN THIS
EVENING AND OVERNIGHT. CONFIDENCE IN TIMING WHEN THE FOG MAY DIMINISH
IS UNCERTAIN. OTHERWISE...IFR/LIFR CIGS WILL ALSO PERSIST AT IWD AND
CMX BUT SHOULD NOT BE AS LOW WITH A MORE DOWNSLOPE SRLY WIND
COMPONENT. AS A DEEP LOW PRESSURE SYSTEM MOVES EAST OF THE AREA
MONDAY MORNING WINDS WILL BECOME NORTH AND QUICKLY STRENGTHEN WITH
ANY RAIN CHANGING TO SNOW.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 523 AM EST SUN NOV 23 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 BY MONDAY MORNING INTO MONDAY NIGHT.
EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS 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...
  DENSE FOG ADVISORY UNTIL 2 PM EST /1 PM CST/ THIS AFTERNOON FOR
     MIZ004>007-010>014-085.

  LAKESHORE FLOOD ADVISORY FROM 11 AM MONDAY TO 6 AM EST TUESDAY
     FOR MIZ001-003-005>007.

LAKE SUPERIOR...
  GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR LSZ251-267.

  GALE WARNING FROM 10 AM MONDAY TO 4 AM EST TUESDAY FOR
     LSZ246>250-265-266.

  GALE WARNING FROM 6 AM MONDAY TO 2 AM EST TUESDAY FOR LSZ242>245-
     263-264.

  GALE WARNING FROM NOON EST /11 AM CST/ TO 9 PM EST /8 PM CST/
     MONDAY FOR LSZ162.

LAKE MICHIGAN...
NONE.
&&

$$

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





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