Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KMQT 281745
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1245 PM EST FRI NOV 28 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 418 AM EST FRI NOV 28 2014

LAKE EFFECT CONTINUES ACROSS ALGER AND LUCE COUNTIES THIS
MORNING...ALTHOUGH IT SHOULD QUICKLY SHIFT EAST AND NORTH THIS
MORNING AS THE BOUNDARY LAYER FLOW SHIFTS W AND SW AHEAD OF THE LOW
PRESSURE SYSTEM OVER THE NRN PLAINS. OTHERWISE...DESPITE THE
INCREASING HIGH CLOUDS AHEAD OF THE SYSTEM...TEMPERATURES REMAIN
QUITE COLD WITH MANY PLACES OVER THE WEST STILL BELOW ZERO.

LIGHT SNOW SHOULD SLOWLY SPREAD EAST AND SOUTHEAST TODAY AS THE
SHORT WAVE AND LEFT EXIT REGION OF THE UPPER JET MOVES TOWARD THE
AREA. MUCH OF THIS INITIAL PRECIPITATION WILL REMAIN NEAR THE
WISCONSIN BORDER THIS MORNING INTO THE EARLY AFTERNOON BEFORE THE
BETTER WARM ADVECTION ALOFT MOVES INTO THE AREA. THE NWP GENERALLY
AGREE THAT UP TO 2 INCHES OF SNOW COULD FALL ACROSS SOUTH CENTRAL
UPPER MICHIGAN TODAY. GIVEN THAT THE BEST WARM ADVECTION AND
MOISTURE WILL REMAIN GENERALLY JUST SOUTH OF THE BORDER...EXPECT
THERE TO BE A FAIRLY SHARP CUTOFF OF PCPN TO THE NORTH...WITH AREAS
CLOSER TO LAKE SUPERIOR GENERALLY SEEING A DUSTING TO AN INCH OF
SNOWFALL TODAY. IT IS POSSIBLE THAT THE EAST SIDE OF THE KEWEENAW
WILL SEE SOME WEAK LAKE ENHANCEMENT LATE THIS AFTERNOON INTO THIS
EVENING AS THE BOUNDARY WINDS TURN SE...BUT THIS IS VERY CONDITIONAL
AND UNCERTAIN AT THIS TIME. EVEN IF SOME ENHANCEMENT DOES
OCCUR...EXPECT IT TO BE VERY SHORT LIVED BEFORE THE WINDS TURN
SOUTHERLY.

A SLIGHTLY DIFFERENT STORY FOR DELTA...SCHOOLCRAFT AND LUCE COUNTIES
THIS AFTERNOON INTO THE OVERNIGHT. WITH RELATIVELY COLD 850MB TEMPS
THROUGH MUCH OF TODAY INTO THIS EVENING...EXPECT LAKE ENHANCED SNOW
TO DEVELOP OFF OF LAKE MICHIGAN IN THE SOUTH-SE FLOW. THE NAM...GEM
AND THE NCEP ARW AND NMM RUNS SEEM TO AGREE THAT THERE WILL BE SOME
LAKE EFFECT BANDS DEVELOPING LATER THIS AFTERNOON...HOWEVER THEY ARE
IN DISAGREEMENT ON EXACTLY WHERE /OR IF/ THEY WILL SET UP OVER ANY
ONE PLACE. IN FACT...THE MODELS TEND TO DEVELOP BANDING BUT KEEP IT
SHIFTING AND SOMEWHAT DISORGANIZED THIS AFTERNOON INTO TONIGHT. THIS
ACTUALLY SEEMS SOMEWHAT REASONABLE GIVEN THE VEERING OF WINDS IN THE
LOWEST 5000 FT...WHILE THE OVERALL PBL WINDS BACK WITH TIME AS THE
850MB WARM FRONT APPROACHES THE AREA. BY 00Z TONIGHT...THE RAP...NAM
AND GEM SHOW THE 1000-850MB WINDS WILL BE DUE SOUTH...ALTHOUGH THE
VERY LOWEST LEVELS WILL BE OUT OF THE S-SE. THIS WOULD SUGGEST THAT
THE BEST SNOW WILL BE OVER DELTA AND SCHOOLCRAFT COUNTIES...AND THE
HIGHER RES NWP EVEN IMPLY THAT ESC MAY SEE A LITTLE LAKE ENHANCEMENT
AS WELL. AS SUCH...WILL OPT TO RAISE POPS TO LIKELY OR CATEGORICAL
ACROSS DELTA AND SCHOOLCRAFT COUNTIES LATER THIS AFTERNOON INTO
TONIGHT...WITH THIS AREAS SEEING 2 TO 4 INCHES OF SNOW. CONTEMPLATED
ISSUING AN ADVISORY...HOWEVER WITH SHIFTING WINDS AND NO INDICATION
OF ANY DOMINATE BANDING DEVELOPING...WILL OPT TO JUST GO WITH A
SPECIAL WEATHER STATEMENT AND HIGHLIGHT THE SNOW IN SOCIAL MEDIA
AVENUES.

OTHERWISE...THE WARM ADVECTION TONIGHT WILL GRADUALLY ALLOW 850MB
TEMPS TO RISE ABOVE 0C ACROSS THE FAR SOUTH LATE TONIGHT. THIS WILL
ALLOW ANY REMAINING PCPN TO TURN TO LIQUID CLOSER TO THE WI BORDER.
HOWEVER...THE LOW LEVEL TEMPS WILL REMAIN BELOW FREEZING AND AS SUCH
THERE IS A POSSIBILITY OF A LIGHT COATING OF GLAZE EITHER FROM
FREEZING RAIN OR FREEZING DRIZZLE. THE 00Z NAM AND GEM SUGGESTED A
SECONDARY AREA OF LIGHT PRECIP MOVING ACROSS THE SOUTHERN PART OF
UPPER MICHIGAN LATE TONIGHT ALONG THE ACTUAL 850MB WARM FRONT.
HOWEVER...THE ECMWF AND GFS DO NOT INDICATE THIS AND IN FACT THE 06Z
NAM HAS BACKED OFF THIS SOLUTION AS WELL. AS SUCH...WILL CONTINUE
WITH MAINLY LOW CHANCE POPS LATE TONIGHT ACROSS THE SOUTH WITH THE
ASSUMPTION THAT THE DRY SLOT WILL MOVE OVERHEAD. NONETHELESS...AS
MENTIONED THERE COULD BE A FEW SLIPPERY SPOTS SAT MORNING ESPECIALLY
ACROSS THE SOUTH. REGARDLESS...TEMPERATURES WILL BE RISING TONIGHT
ACROSS THE ENTIRE AREA DUE TO THE STRONG WARM ADVECTION.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 336 AM EST FRI NOV 28 2014

NAM SHOWS A SHORTWAVE OVER THE PACIFIC NW 12Z SAT WITH THE UPPER
FLOW BEING ZONAL OVER THE UPPER GREAT LAKES. THE TROUGH HEADS EAST
INTO THE NORTHERN ROCKIES 12Z SUN AND INTO THE UPPER GREAT LAKES SUN
NIGHT. COLD AIR MOVES IN ON SUNDAY AND LOOKS LIKE TEMPERATURES WILL
BE FALLING THEN. NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE AND
DEEPER MOISTURE ON SUN MOVING THROUGH THE AREA.

DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST EXCEPT TO BRING
THE COLDER AIR IN QUICKER FOR SAT NIGHT INTO SUNDAY. TEMPERATURES
WILL BE FALLING ALL DAY ON SUNDAY AND HAVE A NON-DIURNAL TEMPERATURE
CURVE FOR THIS. WILL ALSO KEEP MIXED PCPN IN THE FORECAST FOR SAT
WITH FREEZING RAIN/DRIZZLE AND SNOW IN THE MORNING CHANGING TO RAIN
LATE IN THE AFTERNOON AND KEEP LOW CHANCE POPS IN THE FORECAST.

IN THE EXTENDED...GFS AND ECMWF SHOW A DEEP 500 MB TROUGH WITH VERY
COLD AIR 12Z MON OVER THE UPPER GREAT LAKES. 850 MB TEMPERATURES ARE
DOWN TO AROUND -28C AT THAT TIME. THEY QUICKLY MODIFY WITH THE
TROUGH PASSING OFF TO THE EAST 12Z TUE WITH ANOTHER UPPER TROUGH
PASSING THROUGH THE AREA TUE NIGHT. THIS UPPER TROUGH DIGS INTO THE
EASTERN U.S. 12Z THU. THE EXTENDED FORECAST PERIOD LOOKS PRETTY
ACTIVE WITH SNOW THROUGH THE PERIOD AND NO DRY WEATHER EXPECTED AS
LAKE EFFECT WILL BE IN THERE AS WELL. TEMPERATURES WILL START OFF
VERY COLD AND THEN MODIFY WITH TIME WITH TEMPERATURES REMAINING
BELOW NORMAL.
&&

.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 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 AM EST FRI NOV 28 2014

THE HIGH PRESSURE RIDGE WILL SHIFT EAST OF THE AREA TODAY WHILE
DEVELOPING LOW PRESSURE OVER THE PLAINS MOVES TOWARD THE UPPER GREAT
LAKES. 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...MRD
LONG TERM...07
AVIATION...TITUS
MARINE...MRD





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.