Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 282045
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
345 PM EST FRI NOV 28 2014

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 248 PM EST FRI NOV 28 2014

COMPLEX SHORT TERM...AS IS NORMALLY THE CASE DURING TRANSITIONS FROM
SNOW TO MIXED PRECIP AND FREEZING RAIN/DRIZZLE.

A FAST MOVING AREA OF SNOW HAS BEEN TRACKING ACROSS THE SRN CWA
TODAY AND IS NOW MOVING INTO THE SERN CWA. THE SNOW IS AHEAD OF A
WEAK SHORTWAVE CURRENTLY OVER MN AND IN AN AREA OF WAA. GENERALLY UP
TO 1 INCH OF SNOW HAS BEEN OBSERVED WITH THE SYSTEM SNOW. ADDITIONAL
MORE ISOLATED SNOW SHOWERS ARE LOCATED W/WSW OF THE CWA MORE TOWARD
THE SHORTWAVE...WHICH WILL MAINLY MOVE ALONG AND S OF THE WI BORDER
THROUGH THIS AFTERNOON.

LATER THIS EVENING INTO THE OVERNIGHT HOURS ATTENTION TURNS TO AREAS
NEAR LAKE MICHIGAN AS SLY WINDS BRING AN LES BAND NOW ARCHING TO THE
MACKINAC BRIDGE INTO THE AREA. ADDITIONALLY...UPSLOPE/ONSHORE S-SSE
FLOW WILL BRING SNOW SHOWERS TO MUCH OF THE AREA MAINLY E OF A LINE
FROM SAWYER TO MENOMINEE. DO NOT THIS THIS BAND WILL DROP AS MUCH
SNOW IN ANY ONE AREA AS PREVIOUSLY THOUGHT DUE TO MODELS SHOWING THE
BAND BEING MORE TRANSIENT. THIS MAKES SENSE GIVEN THAT LOW LEVEL
FLOW WILL VEER WITH HEIGHT AND ALSO WINDS WILL VEER WITH TIME. HAVE
AROUND 2 INCHES OF SNOW FOR THESE AREAS FROM NOW THROUGH TONIGHT.

THINGS BECOME MORE COMPLICATED LATE TONIGHT AS AN 800-900MB WARM
NOSE WITH ABOVE FREEZING TEMPS MOVES IN FROM THE SW. PRECIP AT THIS
POINT WILL BE MAINLY CONFINED TO DOWNSTREAM OF LAKE MICHIGAN...BUT
LIGHT/ISOLATED PRECIP IS ALSO POSSIBLE ELSEWHERE AS WAA CONTINUES.
ADDITIONALLY...MODELS SHOW A NARROW AREA OF PRECIP AT OR S OF
MENOMINEE ASSOCIATED WITH ANOTHER WEAK SHORTWAVE CURRENTLY OVER ND
RIGHT AROUND THE TIME OF PTYPE TRANSITION. NATURALLY LOTS OF
UNCERTAINTY HOW MUCH AND WHERE THIS PRECIP WILL OCCUR. PRECIP MAY
INITIALLY BE SLEET DURING THE TRANSITION TO FREEZING RAIN AND
EVENTUALLY FREEZING DRIZZLE AS THE DGZ DRIES OUT. IF THAT BAND DOES
SET UP OVER MENOMINEE...GREATER AMOUNTS OF INITIALLY SNOW...THEN
POSSIBLY SLEET AND FREEZING RAIN WOULD OCCUR. MAIN AREA OF CONCERN
WITH FREEZING PRECIP IS DOWNSTREAM OF LAKE MICHIGAN...MAINLY NEAR
AND E OF A LINE FROM MANISTIQUE TO NEWBERRY...WHERE FLOW OFF LAKE
MICHIGAN WILL KEEP PRECIP GOING AS LAKE EFFECT PRECIP COMES TO AN
END. TRANSITION WILL OCCUR CLOSER TO 12Z OVER THE ERN U.P. EVEN WITH
HIGH TEMPS EXPECTED TO BE IN THE MID 30S SAT...ROAD SFC TEMPS IN THE
LOW TO MID 20S WILL LEAD TO ANY LIQUID PRECIPITATION FREEZING ON
CONTACT WITH UNTREATED ROADWAYS...ESPECIALLY BARE ROADS AND ROADS
COVERED IN HARD PACKED SNOW. THEREFORE...MAIN THREAT FROM FREEZING
PRECIP IS ON ROAD/SIDEWALKS...WITH NO SIGNIFICANT THREAT TO ELEVATED
SURFACES. AM NOT VERY CONFIDENT ON AMOUNT OF FREEZING PRECIP
ACCUMULATIONS. WITH FRESH SNOW FALLING TONIGHT /HOPEFULLY HELPING TO
MAKE A CRUSTY COVER ON THE ROADS WHEN THE FREEZING PRECIP
FALLS...THUS KEEPING THE ROADS FROM BECOMING AS SLICK/...AND THE
POTENTIAL IMPACTS FROM FREEZING PRECIP BEING VERY DEPENDENT ON ROAD
SURFACE TREATMENT AND CLEARING OF THE SNOW OFF THE ROADS...WILL NOT
ISSUE ANY HEADLINES FOR THE FREEZING PRECIP. HOWEVER...WILL ISSUE AN
SPS HIGHLIGHTING THE THREAT OVER THE ERN AREAS. ANOTHER AREA THAT
MAY SEE BETTER CHANCES OF FREEZING PRECIP IS THE KEWEENAW PENINSULA
AS SSE WINDS UPSLOPE INTO NRN PORTIONS OF THE PENINSULA...BUT AM
LESS CERTAIN IN THIS AREA AND THINK AMOUNTS WILL BE LOWER THAN OVER
THE ERN UPPER PENINSULA. PRECIP SHOULD DIMINISH SOME OVER THE ERN
U.P. AND THE NRN KEWEENAW SAT AFTERNOON...BUT NOT COMPLETELY END.

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 341 PM EST FRI NOV 28 2014

SAT NIGHT INTO SUN...LOW PRES NEAR LAKE SUPERIOR LIFTING TO THE NE
TO JAMES BAY WILL DRAG A COLD FRONT ACROSS LAKE SUPERIOR. ALTHOUGH
THERE MAY BE SOME LEFTOVER LIGHT RAIN OVER THE FAR ERN CWA...EXPECT
DRY CONDITIONS THROUGH MOST OF SAT NIGHT. MODELS SUGGEST 850-600 MB
FGEN WILL INCREASE LATE INTO WRN UPPER MI AND INTO THE REST OF THE
CWA SUN MORNING. AS 850 MB TEMPS DROP FROM NEAR -12C OVER THE WEST
BY 12Z/SUN TO -18C BY 00Z/MON...LAKE ENHANCED/EFFECT SNOW WILL ALSO
INCREASE FOR NW FLOW FAVORED LOCATIONS. HOWEVER...850-700 MB DRYING
IN THE AFTERNOON WILL LIMIT ACCUMULATIONS TO ONLY LIGHT AMOUNTS OF
AN INCH OR TWO. OVER THE REST OF THE CWA...THE FGEN DYNAMICS COULD
ALSO SQUEEZE OUT SOME LIGHT SNOW WITH ACCUMULATIONS LESS THAN AN INCH.

SUN NIGHT INTO MON...VERY COLD AIR WILL PLUNGE INTO THE NRN LAKES
WITH 850 MB TEMPS DROPPING TO AROUND -25C BY 12Z-18Z/MON. EVEN WITH
STRONG OVER LAKE INSTABILITY (LAKE INDUCED CAPES ABOVE 750 J/KG) THE
DRY AIRMASS AND VERY SHALLOW DGZ WILL SUPPORT MAINLY JUST MODERATE
SNOW AMOUNTS FOR WNW FLOW SNOW BELTS. THE LES SHOULD TAPER OFF BY
LATE MON INTO MON NIGHT AS WINDS BACK TO SW.

TUE-WED...THE MODELS SUGGEST THAT A MID LEVEL AND SFC TROUGH WILL
SLIDE THROUGH THE AREA TUE INTO TUE NIGHT. ONLY CHANCE POPS FOR
LIGHT SNOW WAS INCLUDED AS THE DEEP LAYER QVECTOR CONV WILL HAVE
LITTLE MOISTURE TO WORK WITH. SOME WNW FLOW LES MAY DEVELOP BEHIND
THIS SYSTEM...PER COLDER ECMWF SOLUTION...WITH 850 MB TEMPS DROPPING
TO AROUND -16C ON WED.

THU-FRI...MODEL DIFFERENCES BETWEEN THE ECMWF AND GFS/GEFS WERE
LARGER AS THE GFS BRINGS A SHRTWV THROUGH THE OH VALLEY WHILE THE
ECMWF ALSO PUSHES A NRN STREAM SHRTWV THROUGH THE WRN LAKE THAT COULD
BRING SOME LIGHT SNOW TO UPPER MI.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1244 PM EST FRI NOV 28 2014

AT IWD...SNOW SHOULD END EARLY THIS EVENING. -FZDZ MAY START EARLY
SAT...BUT NOT SURE HOW MUCH WILL ACCUMULATE OR HOW LONG IT WILL LAST.

AT CMX...CONDITIONS ARE NOT EXPECTED TO CHANGE MUCH THROUGH THIS
EVENING. UPSLOPE FLOW IS EXPECTED TONIGHT...WHICH MAY LEAD TO -FZDZ.
WAS CONFIDENT ENOUGH TO INCLUDE FZDZ IN THE FORECAST...BUT AM
UNCERTAIN HOW MUCH WILL ACCUMULATE AND HOW LONG IT WILL PERSIST.

AT SAW...COMPLEX FORECAST AS UPSLOPE FLOW OFF LAKE MICHIGAN WILL
LEAD TO WORSENING CONDITIONS TONIGHT. PRECIPITATION SHOULD
TRANSITION TO LIGHT FREEZING RAIN OR FREEZING DRIZZLE LATE TONIGHT
OR EARLY SAT...BUT AM UNSURE HOW MUCH WILL ACCUMULATE AND HOW LONG
IT WILL PERSIST.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 248 PM EST FRI NOV 28 2014

A DEVELOPING LOW PRESSURE SYSTEM OVER THE PLAINS WILL CONTINUE TO
MOVE TOWARD THE UPPER GREAT LAKES INTO SATURDAY. THIS WILL ALLOW FOR
WINDS TO GRADUALLY TURN SOUTH LATER TODAY INTO TONIGHT...BUT THEY
SHOULD STAY BELOW 20-25 KT. THE FRONT MOVES THOUGH SUNDAY...WHILE
STRONG ARCTIC HIGH PRESSURE BUILDS INTO THE PLAINS. THIS WILL ALLOW
NW GALES TO DEVELOP LATER SUNDAY AND CONTINUE INTO MONDAY. THE HIGH
RAPIDLY SHIFTS OVER THE LAKE MONDAY AFTERNOON...THEN MOVES INTO
QUEBEC BY TUESDAY. HIGH WILL ALLOW FOR A BRIEF RESPITE OF GALES MON
AFTN INTO MONDAY NIGHT...WITH SOUTHERLY GALES POSSIBLE AGAIN ON
TUESDAY ON THE BACK SIDE OF THE HIGH.
&&

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

$$

SHORT TERM...TITUS
LONG TERM...JLB
AVIATION...TITUS
MARINE...TITUS






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