Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 091945
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
245 PM EST TUE FEB 9 2016

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 243 PM EST TUE FEB 9 2016

UPPER AIR PATTERN CONSISTS OF A 500 MB RIDGE IN THE WESTERN U.S. AND
A CLOSED 500 MB LOW IN SOUTHERN ONTARIO WITH A TROUGH IN THE GREAT
LAKES REGION. THIS TROUGH CONTINUES TO MOVE SLOWLY EAST INTO THE
LOWER GREAT LAKES TONIGHT AS THE RIDGE MOVES INTO THE ROCKIES. NAM
SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR CONVERGENCE MOVING
OUT OF THE ERN CWA TONIGHT.

WINDS DO NOT CHANGE MUCH AND NEITHER DOES THE COLD AIR AMOUNT
THROUGH THIS FORECAST PERIOD...SO PERSISTENCE IS THE WAY TO GO WITH
THIS FORECAST. LOOKED AT 950 MB CONVERGENCE WINDS AND THEY STAY
STRONG UNTIL WED AFTERNOON ACROSS THE WESTERN CWA ALONG LAKE
SUPERIOR AND ACROSS MARQUETTE AND ALGER COUNTIES AND FOR THIS
REASON...EXTENDED THE ADVISORY FOR ALGER AND MARQUETTE COUNTIES
UNTIL 00Z WED AND WILL GO WITH AN ADVISORY FOR ONTONAGON AND GOGEBIC
COUNTIES AND KEEP NORTHERN HOUGHTON AND KEWEENAW COUNTIES IN AN
ADVISORY THROUGH THEN. LOOKING AT BUFKIT SOUNDINGS...INVERSION
HEIGHTS REMAIN BELOW 500 FEET THROUGH THIS WHOLE FORECAST PERIOD AS
WELL. OVERALL...DID NOT MAKE MANY BIG CHANGES TO THE GOING FORECAST
EXCEPT DID BUMP UP SNOW AND QPF AMOUNTS A BIT IN NORTHERLY LAKE
EFFECT SNOW BELTS AND HAVE CATEGORICAL POPS IN THOSE AREAS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 500 AM EST TUE FEB 9 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 MUCH COLDER THAN NORMAL
TEMPERATURES BY FRIDAY AND SATURDAY.

WEDNESDAY THROUGH THURSDAY...THE BROAD 500MB TROUGH WILL REMAIN IN
PLACE OVER THE EASTERN CONUS WITH CONTINUED RIDGING OVER THE WEST.
THE SHORTWAVE THAT SLID THROUGH TUESDAY NIGHT WILL CONTINUE TO BE
OVER THE CENTRAL AND EASTERN U.P. WEDNESDAY MORNING BEFORE SLIDING
EAST OF THE AREA BY WEDNESDAY EVENING. 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 MORE FOCUSED SNOW WILL BE OVER THE EASTERN U.P. AS THE DEEPER
MOISTURE WILL LINGER THERE THE LONGEST AND THAT AREA WILL BE IN
CLOSER PROXIMITY TO THE SHORTWAVE AXIS INTO WEDNESDAY EVENING. THE
CHILLY AIR AT 850MB IN THE -20C TO -23C RANGE WILL STILL BE IN PLACE
KEEPING SLR VALUES LOWER THAN WHAT THEY WOULD BE IF THE MOISTURE AND
CONVECTIVE LAYER WERE DEEPER IN THE PREFERRED DGZ. INVERSION HEIGHTS
WILL BE AROUND 6-8KFT OVER THE CENTRAL AND EAST THROUGH WEDNESDAY
EVENING...HOWEVER...THE BETTER MOISTURE IS ONLY PROGGED TO BE IN
PLACE THROUGH ABOUT 5-6KFT. LATE 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 AND A
RIDGE OF HIGH PRESSURE APPROACHES FROM CENTRAL CANADA. WILL STILL
SEE SOME LAKE EFFECT SNOW ONGOING...ON A MUCH DIMINISHED RATE...FOR
MORE NORTHWESTERLY WIND FAVORED AREAS WEDNESDAY NIGHT TO WEST-
NORTHWESTERLY WIND FAVORED AREAS THURSDAY...ESPECIALLY OVER THE
EAST WITH THE INCREASED FETCH.

THURSDAY NIGHT THROUGH SATURDAY...AS THE TROUGH AXIS SLIDES FARTHER
TO THE EAST...THE UPPER PENINSULA WILL BE JUST EAST OF THE
INFLECTION POINT BETWEEN THE TROUGH TO THE EAST AND THE RIDGE TO THE
WEST. THE GFS/EC ARE SHOWING A 500MB CLOSED LOW SLIDING ACROSS
HUDSON BAY THURSDAY NIGHT TO CENTRAL QUEBEC THROUGH SATURDAY
AFTERNOON. AS THIS HAPPENS...EXPECT A COUPLE SHORTWAVES TO ROTATE
THROUGH THE AREA WITH INCREASED MOISTURE WRAPPING THROUGH THE EAST
HALF OF THE CWA. THE MORE PRONOUNCED SHORTWAVE LOOKS TO SLIDE
THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY MORNING. 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 ALONG WITH LAKE EFFECT
SNOW POTENTIAL FOR NORTH TO NORTH-NORTHWEST WIND FAVORED AREAS.
AGAIN...WITH THE BETTER MOISTURE SLIDING OVER THE EAST HALF OF THE
U.P. PLACED THE LIKELY POPS FOR LAKE EFFECT SNOW IN THOSE AREAS NEAR
LAKE SUPERIOR. THE AFOREMENTIONED COLD AIR MOVING IN WILL PRESS THE
FAVORED DGZ DOWN TO THE LOWEST LEVELS OF THE ATMOSPHERE AND IT WILL
BE FAIRLY SHALLOW TOO. THIS WOULD KEEP SNOWFLAKE SIZE FAIRLY SMALL
AND SNOW TO LIQUID RATIOS A BIT LOWER. THE THINGS HINTING TOWARD
HEAVIER SNOWFALL INTENSITY/ MORE PERSISTENT SNOW OVER THE EAST IS
THE INVERSION HEIGHTS PROGGED TO JUMP UP TO NEAR 8KFT OR SO ALONG
WITH INCREASED FORCING IN THAT LAYER THURSDAY NIGHT THROUGH FRIDAY
EVENING.

SATURDAY NIGHT...THE GFS AND EC ARE IN A BIT BETTER AGREEMENT ON
ANTICYCLONIC FLOW SLIDING INTO THE AREA ASSOCIATED WITH A SURFACE
RIDGE MOVING FROM SOUTH-CENTRAL CANADA AND THE NORTHERN PLAINS
EASTWARD INTO THE CWA. THIS...ALONG WITH DRIER AIR AND THE SLOW
APPROACH OF THE UPPER LEVEL RIDGE...SHOULD HELP TO DIMINISH THE LAKE
EFFECT SNOW ACROSS MOST OF THE CWA SATURDAY NIGHT. IF THIS WORKS OUT
AND THE SURFACE RIDGE IS OVERHEAD SATURDAY NIGHT...THE LIGHT WINDS
AND CLEARING SKIES WILL ALLOW TEMPERATURES TO FALL OFF SUBSTANTIALLY
ACROSS THE CWA WITH LOWS POSSIBLY FALLING INTO THE TEENS BELOW ZERO.

SUNDAY THROUGH MONDAY...MODELS DIVERGE DURING THIS TIME PERIOD AS
THE GFS TRIES TO BRING A COLD FRONT AND SHORTWAVE THROUGH THE UPPER
GREAT LAKES REGION DURING THIS TIME PERIOD WHILE THE EC KEEPS A
SURFACE RIDGE...DRIER AIR AND UPPER LEVEL 500MB RIDGE IN THE AREA
THROUGH MOST OF THIS TIME PERIOD. AT THIS POINT WENT WITH A
CONSENSUS OF THE MODELS GIVING ONLY SMALL CHANCES FOR LIGHT SNOW
LATE IN THE WEEKEND INTO EARLY NEXT WEEK.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1149 AM EST TUE FEB 9 2016

A CYCLONIC NNW FLOW OF COLD AIR WILL PERSIST THIS FORECAST PERIOD.
WITH DEEP MOISTURE ALSO LINGERING...EXPECT IFR/LIFR CONDITIONS TO
PREDOMINATE AT ALL SITES THROUGH THE PERIOD.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 243 PM EST TUE FEB 9 2016

GALE FORCE GUSTS WILL CONTINUE INTO THIS EVENING OVER NORTH CENTRAL
LAKE SUPERIOR. NEXT GALES LOOK TO BE THU NIGHT AND FRI ACROSS LAKE
SUPERIOR AS NEXT SHOT OF COLD AIR MOVE IN AND PRESSURE GRADIENT
TIGHTENS UP AGAIN. FREEZING SPRAY WILL ALSO INCREASE WITH THE
HEAVIEST FREEZING SPRAY INTO WED.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST WEDNESDAY FOR MIZ006.

  LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
     MIZ001-003.

  LAKE EFFECT SNOW WARNING UNTIL 4 PM EST /3 PM CST/ THIS
     AFTERNOON FOR MIZ002-009.

  LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST WEDNESDAY FOR MIZ005.

LAKE SUPERIOR...
  HEAVY FREEZING SPRAY WARNING UNTIL 4 PM EST /3 PM CST/ WEDNESDAY
     FOR LSZ162-263>266.

  GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ264.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...KEC
AVIATION...07
MARINE...07


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