Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 021145
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
745 AM EDT THU OCT 2 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 444 AM EDT THU OCT 2 2014

DESPITE THE SOUTHERLY FLOW IN LOW-LEVELS...MAIN WARM FRONT IS WELL
TO SOUTH OVER CNTRL MISSISSIPPI RIVER VALLEY. FRONT ESSENTIALLY IS
JUST TO SOUTH OF WHERE MULTIPLE CLUSTERS OF TSRA ARE CURRENTLY
OCCURRING. STRONG LOW PRESSURE OVER NORTHERN MANITOBA MOVING TOWARD
HUDSON BAY AND A NORTH-SOUTH ORIENTED FRONT FROM THE LOW TOWARD THE
UPPER MISSISSIPPI RIVER VALLEY IS REASON FOR THE SOUTH WINDS OVER UPR
LAKES REGION.

SHOWERS HAVE DEVELOPED OVER SOUTHERN AND EASTERN CWA THIS MORNING
OUT AHEAD OF SHORTWAVE AND ON NOSE OF JET STREAK OVER WISCONSIN AND
WITHIN AREA OF GREATER MOISTURE ADVECTION. THERE IS ALSO A TOUCH OF
MID-LEVEL INSTABILITY BUT NO TSRA HAVE BEEN OBSERVED THUS FAR.
EXPECT SHRA OVER MAINLY EASTERN CWA INTO AT LEAST EARLY AFTN WHILE
REST OF CWA SHOULD BE WITHIN A LULL AS MUCH STRONGER SYSTEM IN FORM
OF TWO MAIN SHORTWAVES...ONE OVER FOUR CORNERS AND THE OTHER STRONGER
ONE OVER WESTERN CANADA DIVING SOUTHEAST OVER SOUTHERN BRITISH
COLUMBIA AND ALBERTA...DOES NOT BEGIN TO AFFECT UPPER GREAT LAKES
UNTIL LATER THIS AFTN AND MORE EMPHATICALLY INTO TONIGHT. BACK TO
TODAY...EXPECT TEMPS TO END UP A BIT ABOVE NORMAL /NORMAL HIGHS UPR
50S TO LOW 60S/ AS 950-900MB TEMPS CONTINUE TO WARM AHEAD OF LARGER
SCALE UPPER TROUGH OVER WESTERN CANADA AND ROCKIES AND CLOUD COVER BY
AFTN SHOULD THIN OUT SOME. EXPECT MAX TEMPS INTO THE 60S...WITH SHOT
AT EVEN SOME UPPER 60S FOR SOME LOCATIONS OVER WEST HALF OF CWA.

INTO THIS EVENING THE WESTERN CANADA SHORTWAVE DIVES ACROSS NORTHERN
PLAINS WHILE THE FOUR CORNERS WAVE HEADS ACROSS KS INTO WESTERN
MO. OVERNIGHT THE NORTHERN PLAINS SHORTWAVE WILL BECOME THE MAIN
SHORTWAVE AS IT PHASES WITH THE SOUTHERN PLAINS WAVE. LIFT WILL
INCREASE DUE TO DEEPENING OF LARGER SCALE TROUGH FROM SCNTRL CANADA
TO SOUTHERN PLAINS/12 HR HEIGHT FALLS UP TO 150DAM SPREADING TOWARD
UPPER GREAT LAKES AND BROAD MODERATE/STRONG H7-H5 Q-VECTOR
CONVERGENCE OVER UPR GREAT LAKES. ENHANCEMENT TO LIFT AS H3 JET
STREAK AMPLIFIES FM UPPER GREAT LAKES TO NORTHERN ONTARIO/HUDSON
BAY...PLACING MUCH OF UPR MICHIGAN WITHIN RIGHT ENTRANCE REGION.
WITH THE BACKGROUND OF THIS LARGER SCALE SUPPORT...STRONG SSW-NNE
MOISTURE ADVECTION RAMPS UP AHEAD OF THE INITIAL NORTH-SOUTH
ORIENTED SFC TROUGH AND AS WAVE OF SFC LOW PRESSURE THAT IS FORMING
OVER SOUTHERN PLAINS THIS MORNING STEADILY DEEPENS AS IT LIFTS ALONG
TROUGH TO A POSITION SOMEWHERE VCNTY OF EASTERN LK SUPERIOR BY
DAYBREAK FRIDAY. OVERALL...CONSENSUS OF MODEL GUIDANCE AND EXPECTED
FORCING AND MOISTURE ADVECTION SUPPORTS LARGE SHIELD OF MODERATE
RAIN LIFTING ACROSS UPR MICHIGAN THIS EVENING AND CONTINUING THOUGH
MOST OF THE NIGHT. QPF AMOUNTS SEEM LIKELY TO REACH 0.75 INCHES OVER
EAST CWA...WHILE AMOUNTS SHOULD STAY BLO 0.50 INCH OVER WEST CWA AS
THAT AREA IS FARTHER REMOVED FM ADVECTION OF MOISTURE WITH PWATS
OVER 200 PCT OF NORMAL. STRENGTH OF DYNAMICS SUGGESTS SOME EMBEDDED
TSRA MAY OCCUR...THOUGH BEST CHANCE WILL BE OVER EAST HALF OF CWA
LATER THIS EVENING AND OVERNIGHT CLOSER TO STRONGER H85-H7 MOISTURE
TRANSPORT AND TRACK OF DEEPENING SFC LOW.

EVEN WITH THE DEEPENING LOW MOVING ACROSS TONIGHT...APPEARS STRONGER
WINDS WILL NOT MATERIALIZE UNTIL MORE SO ON FRIDAY. MINS TONIGHT
WILL BE ON THE MILD SIDE FOR EARLY OCTOBER...WITH NEAR 50 DEGREE
READINGS WEST TO MID-UPR 50S FOR THE EAST.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 523 AM EDT THU OCT 2 2014

THE FIRST HALF OF THE LONG TERM WILL BE DOMINATED BY A DEEP TROF
THAT WILL BE DEVELOPING OVER THE ERN CONUS OVER THE NEXT FEW DAYS.
IMPRESSIVE HEIGHT ANOMALIES MAX OUT OVER THE LOWER OHIO VALLEY EARLY
ON SAT WHERE 500MB HEIGHTS WILL BE 3.5 STANDARD DEVIATIONS BLO THE
LONG TERM EARLY OCT AVG. TROF WILL EVOLVE INTO A LARGE MID-LEVEL LOW
CENTERED OVER NRN ONTARIO FROM LATE SAT THRU THE EARLY PART OF NEXT
WEEK. THIS PATTERN WILL BRING A BLO NORMAL TEMP REGIME. DAILY MAX
TEMPS WILL BE THE MOST ANOMALOUS WITH MANY DAYS HAVING HIGHS WELL
BLO NORMAL. AS WOULD BE EXPECTED...THE WEATHER WILL BE UNSETTLED
WITH LAKE EFFECT/LAKE ENHANCED PCPN UNDER COLD DEEP CYCLONIC FLOW.
AIR MASS WILL BE COLD ENOUGH TO SUPPORT SNOW AT TIMES OVER THE
HIGHER TERRAIN WITH SOME LIGHT ACCUMULATIONS CERTAINLY
POSSIBLE...NOT THAT UNUSUAL FOR EARLY OCT. FARTHER OUT...MEDIUM
RANGE GUIDANCE HAS COME INTO BETTER AGREEMENT ON TIMING THE
TRANSITION TO A MORE PROGRESSIVE/LESS AMPLIFIED FLOW DURING THE
MIDDLE AND END OF NEXT WEEK. THIS WILL LEAD TO MODERATION OF TEMPS
BACK CLOSER TO NORMAL AFTER A COLD EARLY PART OF THE WEEK.

BEGINNING FRI...SFC LOW WILL BE LIFTING N THRU ERN LAKE SUPERIOR
DURING THE MORNING. MDT TO POSSIBLY HVY RAINFALL THAT OVERSPREADS
THE AREA TONIGHT WILL LINGER OVER THE E THRU AT LEAST THE MORNING
HRS AS A RESULT OF ANOTHER SHORTWAVE LIFTING N THRU LWR MI. ECMWF
REMAINS SLOWER THAN OTHER MODELS SHIFTING THIS RAIN OUT OF THE ERN
FCST AREA FRI. IN THE WAKE OF THE MAIN PCPN AREA...A MORE SHOWERY
PCPN REGIME WILL TAKE OVER...BUT WITH MID LEVEL DRYING NOTED...A
GOOD PART OF THE DAY MAY ACTUALLY END UP DRY OVER PORTIONS OF THE W
AND CNTRL. WINDS WILL INCREASE AND TURN GUSTY...ESPECIALLY ACROSS
LAKE SUPERIOR AND THE KEWEENAW UNDER A FAVORABLE WRLY WIND FLOW.

FRI NIGHT...MODELS ARE IN PRETTY GOOD AGREEMENT THAT A REINFORCING
SECOND COLD FRONT WILL DROP THRU THE AREA BRINGING COLDER AIR MORE
FIRMLY INTO THE UPPER LAKES...WITH 850MB TEMPS DROPPING TO -2 TO -4C
BY 12Z SAT. IN CONCERT WITH FAIRLY STRONG DEEP LAYER QVECTOR
CONVERGENCE THAT IS PROGGED TO SHIFT ACROSS THE AREA...LAKE ENHANCED
SHOWERS WILL INCREASE. WETBULB ZERO HEIGHTS SUPPORT THE POTENTIAL
FOR PCPN TO MIX WITH OR EVEN CHANGE TO SNOW OVER THE HIGH TERRAIN OF
FAR W THE NEAR THE WI BORDER.

OVER THE WEEKEND...DEEP...CHILLY AND MOIST CYCLONIC FLOW WILL
DOMINATE AS MID/UPPER LEVEL LOW SPINS OVER NRN ONTARIO. WITH
850MB TEMPS IN THE -3 TO -6C RANGE...EXPECT PLENTY OF CLOUDS AND
LAKE EFFECT PCPN. SHORTWAVES ROTATING AROUND THE LOW WILL BRING
PERIODS OF HEAVIER/MORE WIDESPREAD LAKE ENHANCED PCPN. PCPN ON SAT
WILL BE MOST FAVORED IN AREAS AFFECTED BY NW FLOW LAKE EFFECT.
BACKING WINDS ON SUN WILL SHIFT PCPN TO AREAS THAT ARE MOST AFFECTED
BY WESTERLY FLOW LAKE EFFECT. RAIN WILL MIX WITH OR CHANGE TO SNOW
AT TIMES OVER THE HIGHER TERRAIN...ESPECIALLY DURING THE NIGHT AND
MORNING HRS.

WITH A LENGTHY PERIOD OF STRONG NW TO W WINDS ON LAKE SUPERIOR...
INCLUDING GALES FOR A TIME...AND HIGH LAKE LEVELS (LAKE SUPERIOR
IS CURRENTLY ABOUT 6 INCHES BLO THE RECORD HIGH FOR THIS TIME OF
YEAR)...BEACH EROSION/FLOODING MAY BECOME A PROBLEM FOR AREAS THAT
ARE EXPOSED TO WAVES GENERATED BY W TO NW WINDS.

AS MENTIONED AT THE BEGINNING OF THIS DISCUSSION THERE IS MUCH
BETTER AGREEMENT ON TRANSITIONING FLOW DURING THE MIDDLE AND END OF
NEXT WEEK. AGREEMENT IS GOOD THAT THE MID LEVEL LOW WILL LINGER OVER
NRN ONTARIO THRU AT LEAST MON...WHICH WILL KEEP THE UPPER LAKES
UNDER ITS UNSETTLED INFLUENCE. LOW WILL BEGIN TO LIFT OUT TUE...
LEADING TO A TRANSITION TO DRY WEATHER AND SOME TEMP MODERATION.
MODERATION/DRY WEATHER WILL CONTINUE WED WITH A MORE ZONALLY
ORIENTED FLOW TAKING SHAPE ACROSS THE NRN CONUS.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 743 AM EDT THU OCT 2 2014

MVFR CIGS WILL CONTINUE THROUGH THIS AFTERNOON AT KCMX AND KIWD. AS
NEXT SYSTEM APPROACHES THIS EVENING...CONDITIONS WILL RAPIDLY
DETERIORATE TO IFR/LIFR WITH UPSLOPE RAIN AND FOG. LIFR CONDITIONS
IN FOG AT KSAW THIS MORNING WILL SLOWLY IMPROVE TO MVFR THIS
AFTERNOON WITH SOME DRYING AND LIMITED DAYTIME MIXING. CONDITIONS
WILL DROP AGAIN TO LIFR THIS EVENING AS RAIN MOVES BACK INTO THE
AREA.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 444 AM EDT THU OCT 2 2014

EXPECT DIMINISHING S WINDS THIS MORNING OVER THE EAST. WINDS WILL
REMAIN LIGHT THROUGH MOST OF TONIGHT AS SFC LOW TO THE NORTH ACROSS
LK SUPERIOR. ONCE THE LOW LIFTS TO THE NORTH OF LK SUPERIOR ON
FRIDAY...STRONG WEST WINDS WILL SPREAD ACROSS LK SUPERIOR DUE TO
TIGHT PRESSURE GRADIENT AND THE ARRIVAL OF COLDER AIR. GALE FORCE
WINDS EXPECTED LATER FRIDAY AFTN...AND THESE WILL INCREASE TO 35-40
KTS FRIDAY NIGHT INTO SATURDAY AS WINDS SHIFT TO THE NORTHWEST AS
COLDER AIR MOVES ACROSS LK SUPERIOR. GALE WATCH IN EFFECT FOR ALL
BUT FAR WESTERN LK SUPERIOR FRIDAY AFTERNOON THROUGH EARLY SATURDAY
AFTERNOON. AS IT STANDS NOW...GALE WARNINGS WILL EVENTUALLY BE
ISSUED EITHER LATER TODAY OR TONIGHT.

THOUGH GALES SHOULD DIMINISH ON SATURDAY AFTERNOON...WEST WINDS
20-30 KTS WILL PERSIST INTO SUNDAY AND SUNDAY NIGHT WITH GUSTY
SOUTHWEST WINDS EXPECTED MONDAY INTO TUESDAY OUT AHEAD OF ANOTHER
LOW PRESSURE SYSTEM DROPPING IN FROM SCNTRL CANADA.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
  GALE WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON FOR
     LSZ263>267.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...JLA
LONG TERM...ROLFSON
AVIATION...JLA
MARINE...JLA






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