Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 071202
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
702 AM EST SUN FEB 7 2016

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM EST SUN FEB 7 2016

WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE ALONG
THE WEST COAST RESULTING NW FLOW FROM WRN CANADA INTO THE PLAINS. A
MID LEVEL LOW AND ASSOCIATED SFC LOW WAS SLIDING SE INTO NRN MN.
LIGHT SNOW OVER UPPER MI WAS SUPPORTED BY WAA AND 285K-295
ISENTROPIC LIFT AHEAD OF THE LOW. ADDITIONAL LIGHT SNOW WAS
ASSOCIATED WITH 700-300 MB QVECTOR CONV AHEAD OF A SHORTWAVE
TROUGH MOVING FROM MN INTO WRN WI.

TODAY...EXPECT SNOW OVER MAINLY THE N AND E PORTIONS OF THE CWA THIS
MORNING AS THE UPSTREAM SHRTWV TROUGH MOVES THROUGH. BEHIND THIS
FEATURE...THE PCPN SHOULD TAPER OFF OR END AS A DRY SLOT AND WARM
SECTOR MOVES IN AHEAD OF THE LOW AS IT MOVES INTO WRN LAKE SUPERIOR.
TEMPS REMAIN ON TRACK TOWARD THE MILD GUIDANCE VALUES IN THE MID TO
UPPPER 30S BY MID TO LATE AFTERNOON. THE BEST CHANCE FOR ADDITIONAL
SNOW THIS AFTERNOON WILL BE OVER THE WEST NEAR THE MID/UPPER LEVEL
LOW. EVEN WITH THE MILD CONDITIONS...WET-BULB ZERO HEIGHTS REMAIN
LOW ENOUGH TO KEEP PCPN TYPE AS MAINLY SNOW.

TONIGHT...AS THE MID LEVEL LOW DROPS INTO ERN WI TONIGHT...A SFC
TROUGH WILL SLIDE FROM W UPPER MI DURING THE EVENING TO THE CNTRL
U.P. BY 12Z/MON. INCREASING NNE WINDS BEHIND THE TROUGH WITH CAA
DROPPING 850 MB TEMPS TO AROUND -8C ALONG WITH DEEP MOISTURE AND
WEAK SYNOPTIC SCALE LIFT WILL FAVOR INCREASING LAKE ENHANCED SNOW
OVER THE WEST...ESPECIALLY WHERE UPSLOPE FLOW IS STRONGEST...NEAR
IWD. ALTHOUGH SNOWFALL RATES MAY BE LIGHT TO MODERATE DURING THE
EVENING...EXPECT THE SNOW INTENSITY TO INCREASE OVERNIGHT. SO...AN
ADVY WAS ISSUED FOR GOGEBIC AND ONTONAGON COUNTIES...STARTING AT
00Z/MON WHERE ACCUMULATIONS UP TO 3 INCHES ARE EXPECTED. 1 TO 2 INCH
AMOUNTS ARE ALSO POSSIBLE OVER THE KEWEENAW WITH ANY SNOWFALL OVER
THE CNTRL AND EAST LESS THAN AN INCH.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 456 AM EST SUN FEB 7 2016

THE MAIN ISSUES FOR THE EXTENDED FORECAST PERIOD CONSISTS OF SEVERAL
PERIODS OF LIGHT TO MODERATE LAKE EFFECT SNOW THROUGH THE END OF THE
WORK WEEK ALONG WITH A TREND TOWARD COLDER THAN NORMAL TEMPERATURES
BY NEXT WEEKEND.

MONDAY...THE PATTERN MONDAY WILL CONSIST OF AMPLIFYING RIDGE OVER
THE WESTERN CONUS WITH DEEP TROUGH POSITIONED OVER THE EASTERN CONUS.
A CLOSED 500MB LOW WILL BE PARKED JUST SOUTH OF THE CWA THROUGHOUT
THE DAY WITH WELL DEFINED SURFACE LOW SLIDING FROM CENTRAL UPPER MI
TO EASTERN UPPER MI BY MONDAY EVENING. THE CAA ON THE BACK SIDE OF
THE LOW WILL ALLOW 850MB TEMPS TO DROP FROM -14C/-15C OVER THE WEST
MONDAY MORNING TO AROUND TO -17C/-18C BY MONDAY AFTERNOON AND
EVENING. OVER THE EAST HALF...850MB TEMPS WILL BE AROUND -6C/-7C IN
THE MORNING BEFORE FALLING TO AROUND -10C/-11C MONDAY AFTERNOON AND
EVENING. AT THIS POINT...EXPECTING LAKE EFFECT SNOW TO BE
DEVELOPING/ONGOING OVER THE WESTERN U.P. ON NORTH TO NORTH-NORTHWEST
UPSLOPE FLOW MONDAY MORNING AND CONTINUING THROUGH THE DAY. THE
EASTERN CWA WILL HAVE SOUTHERLY WINDS MONDAY MORNING BEFORE SLOWLY
BECOMING NORTH BY LATE AFTERNOON AND EARLY EVENING. ONCE THE WIND
SHIFTS TO THE NORTH AND 850MB TEMPS BEGIN TO FALL WILL EXPECT LAKE
EFFECT SNOW TO DEVELOP OVER THE EAST HALF BY LATE AFTERNOON AS THE
SURFACE LOW SLIDES EAST. INVERSION HEIGHTS ARE PROGGED TO INCREASE
TO AROUND 5-7KFT THROUGH THE DAY OVER THE FAR WEST WITH MUCH LOWER
INVERSION HEIGHTS EXPECTED CENTRAL AND EAST THROUGH THE DAY. THIS
WOULD LEND SUPPORT TO ENHANCED LAKE EFFECT SNOW OVER THE WESTERN
U.P. THROUGH THE DAY. A GOOD DEAL OF THE MOISTURE IN THE CLOUD LAYER
WOULD BE IN THE DGZ AS WELL...HELPING TO BOOST SNOW RATIOS OVER THE
WEST. AT THIS POINT EXPECT TOTALS DURING THE DAY TO BE AROUND 2 TO 4
INCHES FROM THE HIGH TERRAIN OF THE KEWEENAW SOUTHWEST TO IRONWOOD.
THE HIGHEST TOTALS ARE EXPECTED IN THE HIGHER TERRAIN OF GOGEBIC AND
ONTONAGON COUNTIES WHERE THE WINTER WEATHER ADVISORY IS IN EFFECT.

MONDAY NIGHT THROUGH TUESDAY NIGHT...THE UPPER LEVEL TROUGHING WILL
REMAIN IN PLACE ACROSS THE EASTERN CONUS THROUGH THIS TIME PERIOD
WHILE THE SURFACE LOW SLIDES EVER SO SLOWLY TO THE EAST NEAR LAKE
HURON BY LATE TUESDAY NIGHT. THIS WILL KEEP ALL OF THE U.P. IN NORTH
TO NORTH-NORTHWEST WIND FLOW. 850MB TEMPERATURES WILL STEADILY COOL
ON CAA INTO THE AREA WITH 850MB TEMPERATURES DROPPING FROM AROUND
-14C/-15C MONDAY NIGHT TO AROUND -20C/-22C BY TUESDAY NIGHT. THIS
WILL KEEP LAKE EFFECT SNOW IN THE FORECAST...HEAVIEST IN THE NORTH
TO NORTH-NORTHWEST WIND FAVORED LOCATIONS. THE BEST SNOWFALL
POTENTIAL/HIGHEST SNOW TO LIQUID RATIOS DURING THIS TIME PERIOD
WOULD BE MONDAY NIGHT AS THERE IS STILL A SIGNIFICANT AMOUNT OF
MOISTURE IN THE DGZ WITH INVERSION HEIGHTS PROGGED TO BE AROUND 5-
7KFT. LATE MONDAY NIGHT THROUGH TUESDAY SNOW TO LIQUID RATIOS WILL
LIKELY COME DOWN QUITE A BIT EVEN THOUGH IT WILL LIKELY STILL BE
SNOWING. THE MUCH COLDER AIR SLIDING IN ALOFT WILL PLACE MUCH OF THE
CLOUD LAYER COLDER THAN THE IDEAL DGZ LATE MONDAY NIGHT THROUGH
TUESDAY NIGHT GIVING MUCH SMALLER SNOWFLAKES.

WEDNESDAY THROUGH THURSDAY...THE 500MB TROUGH WILL REMAIN DUG IN
OVER THE EASTERN CONUS WITH CONTINUED RIDGING OVER THE WESTERN
CONUS. AT THE SURFACE...THE LOW PRESSURE SYSTEM OVER LAKE HURON WILL
BEGIN TO SLIDE TO THE NORTHEASTERN U.S BY WEDNESDAY EVENING AND OFF
THE COAST THURSDAY. THIS WILL KEEP MOST OF THE U.P. IN THE CONTINUED
NORTH TO NORTH-NORTHWESTERLY FLOW. THE DEEPER MOISTURE WILL SLOWLY
BEGIN TO EXIT TO THE EAST OF THE AREA THROUGH THE DAY
WEDNESDAY...EVEN THOUGH MOST OF THE U.P. WILL STILL SEE LAKE EFFECT
SNOW AND CONTINUED CLOUD COVER. THE CHILLY AIR AT 850MB WILL STILL
BE IN PLACE KEEPING SLR VALUES LOWER THAN WHAT THEY WOULD BE IF THEY
WERE IN THE PREFERRED DGZ. WEDNESDAY NIGHT INTO THURSDAY...MUCH
DRIER AIR IS PROGGED TO SLIDE INTO THE AREA AS THE UPPER LEVEL
TROUGH AXIS SLIDES EVER SO SLOWLY TO THE EAST. WILL STILL SEE LAKE
EFFECT SNOW ONGOING...ON A MUCH DIMINISHED RATE...FOR MORE
NORTHWESTERLY WIND FAVORED AREAS WEDNESDAY NIGHT INTO THURSDAY.

FRIDAY THROUGH THE EXTENDED...AS THE TROUGH AXIS SLIDES FARTHER TO
THE EAST...THE UPPER PENINSULA WILL BE ON THE INFLECTION POINT
BETWEEN THE TROUGH AND THE RIDGE TO THE WEST. THE GFS/EC ARE HINTING
AT A SHORTWAVE QUICKLY SLIDING THROUGH FRIDAY AND FRIDAY
NIGHT...WHICH WILL PROBABLY GIVE AN UPTICK IN LES FOR THE CWA WITH
ONLY A SMALL AMOUNT OF MOISTURE PROVIDED WITH THE SHORTWAVE. 850MB
TEMPERATURES ARE PROGGED TO FALL EVEN FURTHER DURING THIS TIME
PERIOD POSSIBLY REACHING -30C. THIS WILL ALLOW FOR COLDER THAN
NORMAL TEMPERATURES DURING THIS TIME PERIOD.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 701 AM EST SUN FEB 7 2016

EXPECT IFR TO OCCASIONAL MVFR CONDITIONS THROUGH MUCH OF THE PERIOD
AS LOW PRESSURE APPROACHING NRN MN WILL CONTINUE TO SPREAD LIGHT
SNOW ACROSS THE TAF SITES THIS MORNING. THE LOW PRESSURE SYSTEM WILL
MOVE OVER NE MN AND FAR WRN LAKE SUPERIOR BY 18Z...PUSHING MUCH OF
THE INITIAL AREA OF SNOW NE IN THE AFTERNOON. STEADIER SNOW IS
EXPECTED TO MOVE BACK INTO THE AREA AGAIN THIS EVENING ESPECIALLY
WEST AS CONDITIONS DROP TO LIFR OR NEAR LIFR.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 523 AM EST SUN FEB 7 2016

LOW PRESSURE WILL MOVE INTO WRN LAKE SUPERIOR AND THEN INTO THE
CENTRAL GREAT LAKES BY MON. WINDS WILL SHIFT TO THE N AND INCREASE
TO 30KTS AS THE PRES GRADIENT TIGHTENS BETWEEN THIS LOW AND HIGH
PRES BUILDING INTO SCENTRAL CANADA. THE STRONGER WINDS WILL
CONTINUEINTO WED. WITH THE INFLUX OF COLDER AIR AND STRONG
WINDS...HEAVY FREEZING SPRAY WILL IMPACT THE AREA FROM MON NIGHT
INTO WED AS WELL. THE WINDS AND HEAVY FREEZING SPRAY WILL DIMINISH
LATER ON WED/THU AS THE HIGH PRES EDGES CLOSER TO THE WESTERN LAKES.
THERE MAY BE ANOTHER ROUND OF HEAVY FREEZING SPRAY FRI FOLLOWING
ANOTHER COLD FRONTAL PASSAGE LATE IN THE WEEK.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  WINTER WEATHER ADVISORY FROM 7 PM EST /6 PM CST/ THIS EVENING TO
     7 PM EST /6 PM CST/ MONDAY FOR MIZ002-009.

LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...JLB
LONG TERM...KEC
AVIATION...JLB
MARINE...JLB


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