Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 201801
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
201 PM EDT MON OCT 20 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 441 AM EDT MON OCT 20 2014

...ANOTHER CLOUDY DAY WITH SOME SHOWERS...

WV LOOP AND 00Z RAOBS SHOW MAIN SHORTWAVE TROUGH AXIS SWINGING
ACROSS WESTERN GREAT LAKES. RIDGING IS BUILDING UPSTREAM OVER THE
ROCKIES AND NORTHERN PLAINS...BUT THAT WILL NOT ARRIVE UNTIL LATER
THIS WEEK. THE SUNSHINE WILL BE WELCOME.

MAIN SFC LOW IS OVER EASTERN LK SUPERIOR NEAR WHITEFISH POINT BUT
AIRMASS IN WAKE OF THE LOW NOT ALL THAT COOL WITH MAINLY 40S SEEN
UPSTREAM OVER NORTHWEST ONTARIO. AFTER THE RAIN THAT AFFECTED MOST
AREAS ON SUNDAY AFTN AND EVENING HAS MOVED OUT...IT IS QUIET
CURRENTLY WITH JUST A FEW SHOWERS OVER LK SUPERIOR TIED TO ANOTHER
WEAKER SHORTWAVE WITHIN THE MAIN TROUGH AXIS. A LOT OF CLOUDS STILL
REMAIN /MOIST LAYER UP TO AROUND H85 PER 00Z INL RAOB/ AND CANADIAN
RADAR AND SFC OBS UPSTREAM OVER MANITOBA AND NORTHWEST ONTARIO DO
POINT TO AT LEAST ISOLD SHOWERS WORKING SE TOWARD LK SUPERIOR.

ONCE WINDS TURN NNW AND SLIGHTLY COOLER AIR WORKS OVER THE AREA
BEHIND THE EXITING LOW PRESSURE SYSTEM...THERE IS SUFFICIENT
OVER-WATER INSTABILITY FOR LAKE ENHANCEMENT /DELTA T/S AT AT LEAST
8C/ AS H85 TEMPS FALL TO 0C TO -2C BY AFTN AND AS LK SUPERIOR WATER
TEMPS AVERAGE 7-8C. PERHAPS WITH WEAK DAYTIME HEATING /HIGHS MAINLY
IN THE 40S TO LOW 50S/ AND SOUNDINGS SHOWING MINIMAL CAPE...MAY END
UP WITH HYBRID TYPE LAKE EFFECT/INSTABILITY SHOWERS EXTENDING
FARTHER INLAND THAT JUST THE TYPICAL LAKE EFFECT AREAS. COVERED THAT
WITH ISOLD POPS AS FAR SOUTH AS IRON MTN TO STEPHENSON TO ESCANABA.
BEST CHANCE FOR UP TO A TENTH OF RAIN WILL BE OVER HIGHER TERRAIN OF
CNTRL UPR MICHIGAN. LEANED ON GEM-REGIONAL INTO TONIGHT AS IT SHOWED
STRONGER NORTH TO NORTHEAST FLOW BTWN EXITING LOW AND HIGH PRESSURE
BUILDING OVER NORTHWEST ONTARIO. RESULT WILL BE UPSLOPE SHOWERS OVER
CNTRL UPR MICHIGAN THROUGH MOST OF THE EVENING AND EVEN LINGERING
OVERNIGHT. HOWEVER...LARGE SCALE FORCING IS NIL BY EVENING THOUGH
AND MOIST LAYER IS SUBSIDING BLO H85...SO NOT EXPECTING AS MUCH
COVERAGE AS WHAT WILL OCCUR TODAY. EVEN THOUGH WBZERO HEIGHTS FALL
BLO 1000 FT AGL AFTER MIDNIGHT...SOUNDINGS INDICATE TEMPS WILL BE
WARMER THAN -5C...SUGGESTING THERE WILL NOT BE ANY ICE CRYSTALS AND
THUS MINIMAL CHANCES OF SEEING ANY SNOW. KEPT PYTPE AS RAIN. EXPECT
CLOUDS TO PERSIST THROUGH THE NIGHT...BUT WITH DOWNSLOPING NE WINDS
FORMING OFF ONTARIO IN THE EASTERN CWA AND A DOWNSLOPE FORMING OVER
FAR WEST UPR MICHIGAN...COULD SEE PARTIAL CLEARING LATE. MINS WILL
RANGE FM LOWER 30S IN THE CLEARING AREAS TO UPR 30S TO NEAR 40
DEGREES WHERE CLOUDS HANG ON ALL NIGHT.

FINALLY...SEEMS THERE IS BRIEF PERIOD LATE THIS AFTN INTO THIS
EVENING WHERE N-NE WINDS NEAR LK SUPERIOR...ESPECIALLY VCNTY OF
MARQUETTE AND MUNISING...COULD GET GUSTY. GEM-REGIONAL INDICATED
WINDS UP TO 925MB STARTING THE EVENING IN THE 25-30 KT RANGE AND
ONLY DIMINISHING TO 20-25 KT OVERNIGHT...SO WOULD NOT BE OUT OF
QUESTION TO HAVE 30-40 MPH GUSTS FOR A TIME. NOT EXPECTING THE NEED
FOR ANY KIND OF WIND HEADLINES ON LAND...BUT THE COMBO OF STRONGER
WINDS WILL BUILD WAVES UP ABOVE 8FT ON LK SUPERIOR. GIVEN THE HIGH
WATER LEVELS...THERE MAY BE SOME MINOR BEACH EROSION. MENTIONED
THIS IN THE HAZARDOUS WEATHER OUTLOOK AND HIGHLIGHTED IT IN THE EHWO
GRAPHICS.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 301 AM EDT MON OCT 20 2014

THE UPPER TROUGH THAT IS CURRENTLY SWEEPING THROUGH THE UPPER GREAT
LAKES REGION WILL BE EXITING THE AREA ON TUESDAY MORNING...ALLOWING
AN UPPER/SURFACE RIDGE TO BUILD OVER THE AREA. THESE RIDGES WILL BE
OVER THE AREA THROUGH WEDNESDAY AND LEAD TO DRY WEATHER FOR THE
START OF THE LONG TERM PERIOD. THE ONLY ITEM OF CONCERN FOR THIS
PERIOD WILL BE THE LINGERING CLOUDS OVER THE AREA TUESDAY MORNING
WITH THE LIGHT NORTHEASTERLY FLOW OFF LAKE SUPERIOR AND MOISTURE
TRAPPED BELOW THE LOWERING INVERSION (ESPECIALLY OVER THE NORTH
CENTRAL WITH UPSLOPE FLOW). THESE CLOUDS WILL DIMINISH THROUGH THE
DAY AS THE INVERSION CONTINUES TO LOWER UNDER THE HIGH PRESSURE
RIDGE. HIGHS WILL STILL BE A LITTLE BELOW NORMAL ON TUESDAY (40S)
WITH THE LIGHT FLOW OFF LAKE SUPERIOR AND THE THERMAL TROUGH
STARTING TO DEPART THE AREA. WITH THE CLEAR SKIES AND LIGHT
WINDS...SHOULD SEE ANOTHER COLD NIGHT ACROSS THE AREA ON TUESDAY
NIGHT. WILL CONTINUE TO FOLLOW THE LOW END OF GUIDANCE AND HAVE SOME
INTERIOR LOWS IN THE LOWER 20S. HIGHS ON WEDNESDAY WILL REBOUND
TOWARDS MORE NORMAL VALUES FOR THIS TIME OF YEAR (UPPER 40S TO MID
50S)...WITH THE WARMEST VALUES OVER THE WEST WHERE THE RETURN
SOUTHERLY FLOW DEVELOPS EARLIER.

THE NEXT OPPORTUNITY FOR RAIN WILL COME LATE WEDNESDAY NIGHT INTO
THURSDAY AS AN ELONGATED SHORTWAVE RUNS INTO THE UPPER RIDGE IN
PLACE OVER THE AREA AND WEAKENS. MODELS HAVE VARYING SOLUTIONS ON
HOW THIS WILL EVOLVE...BUT THE GENERAL IDEA FOR A WEAKENING COLD
FRONT MOVING INTO THE UPPER GREAT LAKES REGION IS CONSISTENT.
THUS...WILL CONTINUE TO SHOW SLIGHT CHANCES MOVING INTO THE WESTERN
HALF OF THE CWA BUT WILL KEEP IT FROM SHIFTING INTO THE EASTERN
CWA.

BEHIND THE WEAKENING FRONT AND SHORTWAVE...FRIDAY LOOKS TO BE A
NICE DAY WITH MOSTLY SUNNY SKIES UNDER DRY WESTERLY FLOW ALOFT.
TEMPERATURES WILL DEPEND ON HOW HIGH WE WILL BE ABLE TO MIX INTO
THE WARM AIR ALOFT (850MB TEMPS AROUND 14C)...BUT CURRENT MODEL
FORECASTS HAVE MIXING TO AROUND 925MB WITH THE STRENGTH OF THE
INVERSION. THIS WOULD KEEP HIGHS IN THE UPPER 50S AND LOWER 60S.

MODELS HAVE TRENDED A LITTLE FARTHER TO THE SOUTHWEST WITH AN UPPER
TROUGH DEVELOPING OVER EASTERN CANADA FRIDAY NIGHT AND BRUSHING THE
AREA ON SATURDAY. A COLD FRONT ASSOCIATED WITH THIS FEATURES WILL
SWEEP ACROSS THE AREA LATE FRIDAY NIGHT AND WITH THE BEST
FORCING/MOISTURE TO THE NORTHEAST OF THE AREA...WILL KEEP THE
FORECAST DRY AND SHOW MOSTLY CLEAR SKIES FOR SATURDAY. AN UPPER
RIDGE AND SURFACE HIGH WILL QUICKLY BUILD BACK OVER THE AREA FOR
SUNDAY AND ALLOW FOR CLEAR SKIES AND NORMAL TO SLIGHTLY BELOW NORMAL
HIGHS.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 150 PM EDT MON OCT 20 2014

EXPECT MVFR CIGS TO PREVAIL INTO TONIGHT...THOUGH A PERIOD OF IFR
CIGS SHOULD LINGER EARLY THIS AFTERNOON AT SAW. LAKE ENHANCED RAIN
SHOWERS WILL BE POSSIBLE...MAINLY THIS AFTERNOON AT KSAW. THE
PERSISTENT LOW LEVEL MOISTURE IS EXPECTED TO MOVE OUT OF WEST UPPER
MICHIGAN LATE TONIGHT BUT SHOULD LINGER INTO TUE MORNING AT SAW.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 441 AM EDT MON OCT 20 2014

LOW PRESSURE OVER EASTERN LAKE SUPERIOR NEAR WHITEFISH POINT WILL
MOVE TOWARD THE LOWER GREAT LAKES THROUGH THE DAY AND INTO TONIGHT.
PRESSURE GRADIENT TIGHTENS BTWN THE EXITING LOW AND HIGH PRESSURE
RIDGE BUILDING OVER NORTHWEST ONTARIO. EXPECT NORTH TO NORTHEAST
WINDS INCREASING TO 25-30 KTS THIS AFTN INTO THIS EVENING OVER
CNTRL AND EASTERN LK SUPERIOR. WINDS WILL DIMINISH TUESDAY MORNING
AS THE HIGH PRESSURE RIDGE SETTLES ACROSS LK SUPERIOR. WINDS SHOULD
REMAIN LESS THAN 20 KTS FOR THE REST OF THE WEEK...WITH STRONGER
WEST TO NORTHWEST WINDS UP TO 30 KTS POSSIBLE ON SATURDAY AS A LOW
PRESSURE SYSTEM CROSSES NORTHERN ONTARIO.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

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





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