Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 282105
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
405 PM EST FRI NOV 28 2014

.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 401 PM EST FRI NOV 28 2014

...SOME ACCUMULATING SNOW TONIGHT...POSSIBLE LATE NIGHT FREEZING
DRIZZLE...

HIGH IMPACT WEATHER POTENTIAL: GENERALLY MINIMAL. SOME ICY ROADS.

PATTERN SYNOPSIS/CURRENT CONDITIONS: RATHER STOUT WAA BEGINNING TO
RAMP UP NICELY ACROSS THE WESTERN LAKES AT THIS HOUR...WITH +10C H8
AIR REACHING AS FAR WEST AS SOUTHWEST MINNESOTA...WITH SAME LEVEL
TEMPERATURES REMAIN IN THE NEGATIVE TEENS OVERHEAD. BROAD AREA OF
MOSTLY LIGHT SNOW A RESULT OF THIS INCREASING WARM AIR
INVASION...ALTHOUGH LACK OF DEEPER MOISTURE/MORE ORGANIZED LARGE
SCALE FORCING LEADING TO A RATHER DISJOINTED SNOW SHIELD. AS
MENTIONED...STILL PLENTY COLD AROUND THESE PARTS...COLD ENOUGH TO
CONTINUE TO ENTICE SOUTHWEST FLOW LAKE SNOW DEVELOPMENT INTO THE TIP
OF THE MITT AND STRAITS REGION. THAT ITSELF HAS NOT BEEN TOO
INTENSE...A PRODUCT OF A RATHER LOW CBL (INVERSION AT H8) AND AN
INCREASINGLY MARGINAL OVER-LAKE THERMODYNAMIC PROFILE. WAA WILL
NOT BE DENIED IN THIS ZONAL FLOW REGIME...SUPPORTING UPSTAIRS
TEMPERATURES WARMING SEVERAL DEGREES OVERNIGHT. THIS BRINGS WITH
IT A SOMEWHAT COMPLICATED FORECAST...BOTH IT TERMS OF SNOWFALL
AMOUNTS AND POSSIBLE LATE NIGHT PRECIP TYPE ISSUES.

PRIMARY FORECAST CHALLENGES/CONCERNS: SNOW AMOUNTS AND POSSIBLE LATE
NIGHT FREEZING DRIZZLE POTENTIAL.

DETAILS: AS MENTIONED...SIMPLY NO DENYING NOW WELL DEVELOP WAA
REGIME...WITH PERSISTENT SOUTHWEST H8 FLOW HELPING DRIVE TEMPERATURES
AT THAT LEVEL UP SEVERAL DEGREES THROUGH THE OVERNIGHT. THIS WILL
HELP EXPAND AN AREA OF MOSTLY LIGHT SNOW THROUGH MUCH OF THE AREA
THIS AFTERNOON AND INTO MUCH OF THE OVERNIGHT. STILL APPEARS THE
STEADIEST SNOWS WILL OCCUR SOUTH OF THE BRIDGE...BUT EVEN HERE LACK
OF DEEPER MOISTURE AN STRONGER DYNAMICS EXPECTED TO KEEP AMOUNTS
GENERALLY ON THE LIGHT SIDE. OVERALL..EXPECTING NOT MUCH MORE THAN
AN INCH OR TWO...HIGHEST AMOUNTS SOUTH OF M-32. STILL EXPECTING SOME
LAKE ENHANCEMENT TO CONTINUE TO PUSH INTO AREAS NEAR THE STRAITS AND
POINTS WEST IN MACKINAC COUNTY...ESPECIALLY LATER THIS AFTERNOON AND
EVENING. PER RECENT RADAR TRENDS AND OBSERVATIONS...NOT EXPECTING
THIS TO BE A BIG DEAL EITHER...WITH PERHAPS AN INCH OR TWO WHERE
ENHANCEMENT OCCURS LONGEST. WARMING THERMAL PROFILES AND CONTINUED
BACKING OF WINDS SHOULD QUELL THE LAKE RESPONSE LATE TONIGHT.

OTHER ISSUE LATER TONIGHT INVOLVES AT LEAST THE POTENTIAL FOR SOME
FREEZING DRIZZLE. THE ANSWER IS NOT A DEFINITE ONE...WITH EVIDENCE
OF ONLY PARTIAL LOSS OF MID LEVEL MOISTURE...AND THAT ITSELF LOOKS
FLUCTUATING. WILL CONTINUE TO MENTION THE POSSIBILITY FOR NOW...BUT
NO DOUBT JUST CHANCE WORDING WILL SUFFICE.

TEMPERATURES EXPECTED TO GO MUCH OF NOWHERE THIS EVENING...WITH
READINGS SLOWLY RISING THROUGH THE OVERNIGHT...WITH SOME AREAS ALONG
THE LAKE MICHIGAN SHORELINE PUSHING FREEZING BY SUNRISE SATURDAY.

&&

.LONG TERM...(SATURDAY THROUGH FRIDAY)
ISSUED AT 401 PM EST FRI NOV 28 2014

...LIGHT MIXED PRECIPITATION SATURDAY/FOG SATURDAY NIGHT SUNDAY...

HIGH IMPACT WEATHER POTENTIAL: SOME LIGHT MIXED PRECIPITATION
SATURDAY WITH THE POTENTIAL FOR SOME FREEZING DRIZZLE/LIGHT
FREEZING RAIN. POSSIBLY DENSE FOG DEVELOPING SATURDAY NIGHT INTO
EARLY SUNDAY BEFORE TURNING COLDER SUNDAY AFTERNOON/NIGHT.

PATTERN SYNOPSIS/FORECAST: HEMISPHERIC PATTERN ANCHORED BY LONG WAVE
TROUGHS OVER NORTH AMERICA AND EASTERN ASIA.  LOW AMPLITUDE SHORT
WAVE RIDGE MOVING THROUGH THE WESTERN MOUNTAINS/HIGH PLAINS...WITH A
SPLIT SHORT WAVE TROUGH IMPACTING THE WEST COAST...NORTHERN BRANCH
WAVE OVER BRITISH COLUMBIA WITH SOUTHERN BRANCH FEATURE AROUND 135W
OFF THE U.S. WEST COAST.  AT THE SURFACE...1031MB HIGH CENTERED OVER
TENNESSEE WITH A RIDGE AXIS EXTENDING NORTH INTO THE UPPER GREAT
LAKES...ELONGATED FRONT EXTENDS FROM SOUTHERN BRITISH COLUMBIA
SOUTHEAST INTO NEBRASKA/EASTERN KANSAS/MISSOURI WITH SEVERAL FRONTAL
WAVES ALONG THE BOUNDARY.  VERY COLD AIR ACROSS CANADA WITH
WIDESPREAD SUB-ZERO TEMPERATURES.

AS NORTHERN BRANCH SHORT WAVE TROUGH OVER WESTERN CANADA DROPS INTO
THE PACIFIC NORTHWEST/INTERMOUNTAIN WEST...ZONAL FLOW WILL PREVAIL
DOWNSTREAM ACROSS THE REMAINDER OF THE CONTINENTAL U.S.  RESULTANT
HEIGHT FALLS WILL THEN SPREAD ACROSS THE NORTHERN PLAINS/CANADIAN
PRAIRIES...AND THEN ACROSS THE UPPER MIDWEST/UPPER GREAT LAKES IN
THE SUNDAY/MONDAY TIME FRAME.  ONE OF THE FRONTAL WAVES UPSTREAM
WILL DEEPEN TONIGHT AND RIDE EAST ACROSS THE DAKOTAS WHILE ARCTIC
FRONT SINKS INTO THE ROCKIES.  THIS LOW IS EXPECTED TO TRACK TO THE
NORTH OF LAKE SUPERIOR SATURDAY NIGHT...AND DRAG THE ARCTIC FRONT
ACROSS THE UPPER LAKES SUNDAY...WITH SURFACE PRESSURES IN THE
VICINITY OF 1045MB ACROSS THE MIDWEST MONDAY (SOMEWHAT UNUSUAL IN A
CLIMATOLOGICAL SENSE FOR EARLY DECEMBER) AS COLD AIR SPILLS BACK
INTO MICHIGAN.

PRIMARY FORECAST CONCERNS (NEAR TERM): PRECIPITATION CHANCES/TYPE
FOR SATURDAY...FOG POTENTIAL LATER SATURDAY INTO THE FIRST PART OF
SUNDAY PRIOR TO COLD FRONTAL PASSAGE...THE IMPACTS OF WITH THE FRONT
AND POST-COLD FRONT LATER SUNDAY IN MONDAY.

NEAR TERM (SATURDAY/SUNDAY/MONDAY): LOW/MID LEVEL WARM ADVECTION
WILL BE ONGOING SATURDAY MORNING...THOUGH MOISTURE DEPTH MAY BE
VARYING ACROSS THE FORECAST AREA AT THE ONSET WITH DRIER MID LEVELS
NORTH SUGGESTING A MORE FLURRIES/FREEZING DRIZZLE LOOK TO THINGS.
WILL PROBABLY GO WITH CHANCE POPS/LOW QPF TYPE EVENT TO COVER
THIS...SUSPECT PRECIPITATION WILL BE SOMEWHAT PATCHY.  DEVELOPMENT
OF A WARM NOSE ABOVE A BELOW FREEZING BOUNDARY LAYER MAY ALLOW FOR
SOME ICE PELLETS/FREEZING RAIN TO MIX IN...WITH A TREND TOWARD MORE
DRIZZLE ACROSS NORTHERN LOWER DURING THE AFTERNOON WITH TEMPERATURES
CLIMBING NEAR/ABOVE FREEZING.  STILL LIKE THE IDEA OF AN INCREASING
FOG THREAT HEADING INTO SATURDAY NIGHT WITH INCREASING LOW LEVEL DEW
POINTS GETTING ADVECTED OVER MELTING SNOW COVER...ALONG WITH STEADY
OR SLOWLY RISING TEMPERATURES.

COLD FRONT EXPECTED TO CROSS NORTHERN MICHIGAN DURING THE MORNING
HOURS...LIKELY CLEARING THE SOUTHEAST PORTION OF THE FORECAST AREA
DURING THE FIRST PART OF THE AFTERNOON.  FORECAST TRENDS STILL
SUGGEST NOT MUCH HAPPENING AS THE FRONT PASSES...THERE IS A SIGNAL
FOR A POST-FRONTAL FRONTOGENETICALLY DRIVEN BAND OF SNOW THAT MAY
JUST IMPACT EASTERN UPPER/FAR NORTHERN LOWER DURING THE AFTERNOON.
SO EARLY PRE-FRONTAL FOG EXPECTED TO GIVE WAY WITH FRONTAL
PASSAGE...WITH SOME SYNOPTIC LIGHT SNOW TRANSITIONING TO LAKE
INDUCED CONVECTION SUNDAY NIGHT WITH ONSET OF STRONG LOW LEVEL COLD
ADVECTION.  THOUGH 850MB TEMPERATURES SINK QUICKLY BELOW -15C...DRY
AIR ABOVE A NOT PARTICULARLY DEEP CONVECTIVE BOUNDARY LAYER NOT
EXPECTED TO YIELD A BIG SNOWFALL BOUNTY SUNDAY NIGHT.

LAKE INDUCED SNOW SHOWERS CONTINUE MONDAY...MOST PREVALENT IN
NORTHWEST FLOW LAKE SNOW BELTS.  COULD SEE A FEW INCHES ACROSS
CHIPPEWA COUNTY IN BANDS OFF LAKE SUPERIOR.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1158 AM EST FRI NOV 28 2014

WIDESPREAD LIGHT SNOW EXPECTED TO SPREAD ACROSS ALL TAF SITES
LATER THIS AFTERNOON THROUGH MUCH OF THE OVERNIGHT...PRODUCING
MVFR/OCCASIONAL IFR CONDITIONS. SNOW INTENSITY CHANGES WILL BE
FREQUENT...SUGGESTING IFR CONDITIONS WILL BE INTERMITTENT. MID
LEVEL MOISTURE BEGINS TO STRIP OUT LATE...AND ESPECIALLY SATURDAY
MORNING...SUGGESTING FZDZ MAY ENTER THE MIX. CIGS WILL CONTINUE TO
LOWER DURING THE MORNING AS THIS OCCURS...POSSIBLY SUPPORTING MORE
WIDESPREAD IFR CONDITIONS. LIGHT WINDS THROUGHOUT THIS TAF PERIOD.


&&

.MARINE...
ISSUED AT 401 PM EST FRI NOV 28 2014

DEPARTING SURFACE RIDGE WITH ALLOW SOUTHERLY WINDS TO INCREASE
TONIGHT INTO SATURDAY AHEAD OF A COLD FRONT THAT WILL PASS ACROSS
THE UPPER LAKES SUNDAY.  MARGINAL SMALL CRAFT ADVISORY CONDITIONS
POSSIBLE SATURDAY AND INTO SATURDAY NIGHT PARTICULARLY ACROSS THE
LAKE MICHIGAN NEARSHORE ZONES.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...MSB
LONG TERM...JPB
AVIATION...MSB
MARINE...JPB



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