Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 301638
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1138 AM EST FRI JAN 30 2015

.UPDATE...
ISSUED AT 1138 AM EST FRI JAN 30 2015

13Z SURFACE ANALYSIS SHOWS A BROAD 1035+MB HIGH CENTERED OVER THE
MIDWEST...COLD FRONT THAT CROSSED NORTHERN MICHIGAN THURSDAY NIGHT
NOW ACROSS NEW YORK/PENNSYLVANIA.  PLENTY OF SUB-ZERO COLD
HORSESHOEING AROUND THE UPPER GREAT LAKES...WITH TEENS AND 20S BELOW
ZERO AROUND THE NORTH/EAST SIDES OF LAKE SUPERIOR.  MICHIGAN LIES IN
THE WAKE OF A SHORT WAVE TROUGH HEADING ACROSS THE LOWER LAKES/
MISSISSIPPI VALLEY WITH ATTENDANT SUBSIDENCE/UPPER LEVEL CONVERGENCE
ACROSS THE FORECAST AREA.  WATER VAPOR IMAGERY SHOWS A HINT OF SOME
ENERGY ACROSS THE DAKOTAS/MINNESOTA...DEFINITELY SOME WARM ADVECTION
AND MID LEVEL MOISTURE/CLOUDS ACROSS MANITOBA/NORTHERN MINNESOTA/
WESTERN WISCONSIN...THOUGH DRY LOWER LAYERS PER 12Z MPX/INL RAOBS.
LOW LEVEL THERMAL TROUGH DRAPED ACROSS THE GREAT LAKES ALLOWING FOR
MULTI-BAND LAKE CONVECTION OVER THE SURROUNDING LAKES...WITH NORTH-
NORTHWEST LOW LEVEL WINDS.  14Z LOCAL MESOANALYSIS SHOWS A WELL-
DEFINED CONVERGENCE AXIS FEEDING INTO A SINGLE BAND COMING INTO THE
LEELANAU PENINSULA AND FAR WESTERN GRAND TRAVERSE/WEXFORD COUNTIES.
12Z APX SOUNDING INVERSION HEIGHT JUST A SHADE BELOW 850MB...AT A
TEMPERATURE OF -22C.

PRESSURES RISING ACROSS MICHIGAN THIS AFTERNOON AS UPSTREAM HIGH
PUSHES EAST.  BACKING LOW LEVEL WINDS WILL SHIFT ONGOING LAKE BANDS
INLAND ACROSS EASTERN UPPER/NORTHWEST LOWER.  LINGERING SINGLE BAND
INTO LEELANAU COUNTY WILL SHIFT EAST AND FALL APART DURING EARLY
AFTERNOON WITH LOSS OF SUPPORTING LOW LEVEL CONVERGENCE AND
EFFECTIVE FETCH FROM LAKE SUPERIOR.  PARTLY/MOSTLY SUNNY SKIES
ACROSS MUCH OF EASTERN UPPER SHOULD GIVE WAY TO MORE CLOUDS LATER
THIS AFTERNOON...MIXED SKIES OVER NORTH CENTRAL/NORTHEAST LOWER
EXPECTED TO SEE MORE CLOUDS LATER WITH BACKING WINDS. WINTER WX
ADVISORY WILL BE ALLOWED TO EXPIRE AT MIDDAY.

UPDATE ISSUED AT 614 AM EST FRI JAN 30 2015

WAS THINKING EARLIER ABOUT DROPPING THE ADVISORY AT 7AM...BUT
THERE ARE STILL LAKE BANDS WITH A CONNECTION TO LAKE SUPERIOR AND
THERE IS STILL SOME MORE TIME FOR GUSTY WINDS TO BLOW AROUND SNOW.
WILL LET THE ADVISORY RIDE A BIT FURTHER INTO THE MORNING...AS WE
SHOULD BEGIN LOSING THE LAKE SUPERIOR CONNECTION OVER THE NEXT FEW
HOURS.

&&

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 1252 AM EST FRI JAN 30 2015

...COLD!...

SYNOPTIC PATTERN AND OBSERVATIONS:

EARLY THIS MORNING...SHARP UPPER TROUGH OVER THE EAST AN ASSOCIATED
SFC LOW...AND STRONG COLD FRONT THAT IS WORKING INTO THE EAST
COAST. BROAD RIDGING ACROSS THE WEST COAST...WITH A WEAK CYCLONIC
CIRCULATION BURIED UNDERNEATH...SEEN ON LATEST SATELLITE LOOPS
ACROSS FAR SRN CALIFORNIA/AZ AND PRODUCING RAINFALL ACROSS THE SW
CONUS. IN BETWEEN...ACROSS THE MISSISSIPPI VALLEY...SFC HIGH
PRESSURE AND COLD RESIDES. IN NRN MICHIGAN SPECIFICALLY...WE STILL
HAVE A TIGHT PRESSURE GRADIENT WITH NW WINDS GUSTING 25 TO 35 MPH
AND BECOMING COLDER. STRONGEST WINDS ARE OVER AND IMMEDIATELY
DOWNWIND OF LAKE MICHIGAN. LAKE EFFECT SNOWS ARE ONGOING WITH H8
TEMPS FALLING THROUGH THE TEENS. THE BETTER CYCLONIC CONVERGENCE IS
BECOMING MORE UNIDIRECTIONAL...VEERING MORE NNW WITH TIME.
RELATIVELY SHALLOW INVERSION HEIGHTS (INCREASING SUBSIDENCE) AROUND
4000-4500 FEET ARE LIKELY BEING OFFSET IN PART DUE TO GOOD LIFT
WITHIN THE DGZ/OPTIMAL TEMPERATURES...RESULTING IN DECENT SNOWFALL
WITHIN THE BANDS. OF COURSE THE GUSTY WINDS ARE ALSO PERIODICALLY
BLOWING AROUND THE SNOW AND HELPING DECREASE THE VISIBILITY. PRETTY
WINTRY AND NASTY MAINLY WITHIN THE LAKE EFFECT BANDS AND WHERE
APPRECIABLE SNOWS FELL YESTERDAY. A WINTER WEATHER ADVISORY IS IN
EFFECT FOR THE BETTER SNOWFALL AND WINDS...POORER CONDITIONS WEST
AND SOUTH OF GTV BAY. THE FLOW ALOFT IS RATHER FAST...WITH SOME
SHEARED OUT VORTICITY STRETCHING DOWN THE NW FLOW INTO ND/MN...AND A
BETTER WAVE NOW ENTERING FAR NRN SASKATCHEWAN/MANITOBA. PWATS
UPSTREAM ARE AROUND 0.25".

TEMPERATURES RANGED FROM THE SINGLE DIGITS FOR MUCH OF EASTERN
UPPER...TO THE UPPER TEENS AND LOWER 20S ALONG M-55.

SYNOPTIC PATTERN EVOLUTION AND ASSOCIATED WEATHER:

COLD AND GUSTY NNW FLOW WILL WEAKEN THROUGH THE DAY AS A LOOSER
PRESSURE GRADIENT ARRIVES...WHILE CORE OF HIGHER PRESSURE SINKS INTO
THE OHIO VALLEY. IT`LL BE QUITE CHILLY TO START THE DAY WITH
TEMPERATURES IN THE SINGLE BELOW AND ABOVE ZERO FOR MOST OF THE
REGION...AND WIND CHILLS 5 TO 20 BELOW ZERO. NOT AS COLD WEST AND
SOUTH OF GTV BAY DUE TO CLOUDS AND LAKE EFFECT SNOWS...BUT CERTAINLY
THE CONTINUATION OF THE SNOW AND GUSTY WINDS RESULTING IN
PERIODICALLY POOR DRIVING CONDITIONS. WILL KEEP CURRENT WINTER
WEATHER ADVISORY GOING. AS WINDS CONTINUE TO WEAKEN INTO THE
AFTERNOON...THEY WILL ALSO BE BACKING MORE WEST IN RESPONSE TO
ADVANCING NRN MANITOBA/SASKATCHEWAN WAVE. DECAY OF MOISTURE FLUX AND
A DRYING BL...WILL RESULT IN A GRADUAL DECAY OF LAKE EFFECT. SUPER
SUFFICIENT 925MB INSTABILITY HOWEVER WILL LIKELY LEAD TO AT LEAST
FLURRIES INTO THE NIGHT...AND MORE SCATTERED/LIKELY SNOW SHOWERS FOR
THE OVERNIGHT. THIS WOULD BE ACROSS A GOOD CHUNK OF NW LOWER AS THE
UPSTREAM SHORTWAVE...BRINGS A LITTLE BIT OF LIGHT SNOW...ENHANCED BY
THE SHALLOW INSTABILITY. THE SNOWS MAY POSSIBLY WORK INTO THE
STRAITS/DRUMMOND ISLAND...WITH LOW LEVEL WINDS JUST A SHADE SOUTH OF
DUE WEST.

MOST LIKELY NO MORE THAN AN INCH...EVEN ACROSS NW LOWER WITH LAKE
HELP.

LOWS MAINLY 10-20F WITH LOWS TONIGHT DIFFICULT WITH A PERIOD OF
CLEARING ACROSS NE LOWER AND TO A SHORTER PERIOD OF TIME EASTERN
UPPER (WEST FLOW). TEMPERATURES WILL BE CRASHING WHEN THIS OCCURS.
CAN FORESEE SINGLE DIGITS BELOW ZERO EASILY ATTAINABLE IN THESE
AREAS...WITH CLOUDY AREAS IN THE TEENS.

&&

.SHORT TERM...(SATURDAY THROUGH SUNDAY NIGHT)
ISSUED AT 335 AM EST FRI JAN 30 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING MAJOR FORESEEN THROUGH THE
WEEKEND. THERE STILL APPEARS TO BE A LOW END RISK FOR SOME FREEZING
DRIZZLE SATURDAY AFTERNOON AND MAYBE SATURDAY EVENING...BUT THE
OVERALL IMPACT LOOKS MINOR GIVEN ALREADY SNOW COVERED/SLUSHY ROADS
THAT WILL REMAIN THAT WAY THROUGH THE WEEKEND.

A FAMILIAR-LOOKING PATTERN WITH THE PARADE OF NORTHERN STREAM
SHORTWAVES CONTINUING...SOME DROPPING TOWARD THE AREA AND SOME
SKIRTING JUST NORTH. SATURDAY`S ITERATION WILL FEATURE A MODEST WAVE
PASSING THROUGH ONTARIO...DRAGGING A TRAILING COLD FRONT THROUGH THE
AREA DURING THE AFTERNOON HOURS. MAJORITY OF THE UPPER FORCING WITH
SAID WAVE WILL PASS TO OUR NORTH...LEAVING US HINGING OUR BETS ON
WHATEVER SORT OF LOW LEVEL/FRONTAL FORCING WE CAN MUSTER FOR PRECIP
CHANCES. BRIEF BUT NOTABLE INTRUSION OF "WARMER" AIR ALOFT LOOKS TO
WORK INTO THE REGION THROUGH MIDDAY...WITH A LACK OF MOISTURE ABOVE
800MB AND CLOUD TOP TEMPS WARMING ABOVE -10C AT LEAST RAISING AN
EYEBROW TOWARD THE POTENTIAL OF A LITTLE FREEZING DRIZZLE. AS
MENTIONED YESTERDAY...THE AMBIENT AIRMASS TO ME JUST LOOKS A LITTLE
TOO COOL TO SUPPORT ANY SIGNIFICANT FREEZING DRIZZLE...AND EVEN IF
IT WERE TO OCCUR (MOST LIKELY SOUTH OF M-32)...ANY IMPACT SHOULD BE
MINOR GIVEN THE TIME OF DAY IT WOULD OCCUR (DURING THE DAYLIGHT
HOURS). FARTHER NORTH...WEAK FRONTAL FORCING AND DEEP ENOUGH
MOISTURE UP TO 800MB WITH CLOUD TEMPS DOWN AS LOW AS -15C SHOULD BE
ENOUGH TO BRING AT LEAST A BRIEF ROUND OF SOME LIGHT SNOW SHOWERS
FOR MANY AREAS ALONG AND JUST BEHIND THE BOUNDARY. ACCUMULATION
LOOKS MINOR BUT IT WILL LIKELY SNOW...THUS HIGHER POPS WILL REMAIN.

WE SORT OF SIT IN NO MAN`S LAND SATURDAY EVENING AS COLDER AIR JUST
STARTS TO FILTER INTO THE REGION...ALL WHILE WE AWAIT UPSTREAM
TRENDS TO SEE JUST HOW MUCH PHASING CAN GET TAKE PLACE OVER THE
PLAINS/MID MISS VALLEY. SIMILAR TO WHAT OCCURRED THURSDAY
AFTERNOON...CAN`T COMPLETELY RULE OUT ANOTHER PERIOD OF SOME LIGHT
FREEZING DRIZZLE WITH SATURATION SHRINKING BELOW 850MB BUT COLD AIR
ADVECTION ONLY SLOWLY KICKING INTO GEAR. THAT THREAT SHOULD BE GONE
NO LATER THAN 03-06Z AS SOME VERY CHILLY AIR WORKS BACK INTO THE
AREA AS EXPANSIVE LOW LEVEL RIDGING FROM THE NORTHERN PLAINS INTO
ONTARIO KICKS OUR LOW LEVEL FLOW ALMOST DUE NORTHERLY.

NOW...SPEAKING OF POTENTIAL PHASING TO OUR SOUTH...GUIDANCE TRENDS
AND SIMPLE PATTERN RECOGNITION CONTINUE TO FAVOR LITTLE IMPACT THIS
FAR NORTH HEADING INTO SUNDAY. LOOKING MORE AND MORE LIKELY THAT
ANOTHER NORTHERN STREAM WAVE WORKING THROUGH ONTARIO WILL ACT TO
BLOCK ANY NORTHWARD PROGRESS OF THE STRONGER WAVE OVER THE MID MISS
VALLEY. NOT HELPING MATTERS WILL ALSO BE THE ABOVE-MENTIONED VERY
STRONG LOW LEVEL RIDGING (SURFACE PRESSURES NEARING 1044MB TO OUR
WEST)...ALSO ACTING AS A FORMIDABLE BLOCK TO ANY NORTHWARD PROGRESS
OF THE SURFACE LOW THAT IS MORE LIKELY TO SKIRT THROUGH THE
TENNESSEE VALLEY. GIVEN THAT SCENARIO...COULD WELL END UP SEEING A
GOOD DEAL OF INLAND SUNSHINE FOR SUNDAY AND CLEAR SKIES SUNDAY
NIGHT...AS NORTH FLOW FAVORS CLOUDS AND LIGHT SNOW SHOWERS NEAR THE
LAKESHORES BUT POTENTIALLY SOME QUITE COLD CONDITIONS INLAND. SHEAR
MAGNITUDE OF THE COLD AIR (H8 TEMPS IN THE -19C TO -23C RANGE) AND
VERY SHALLOW MOISTURE ARGUES FOR ONLY VERY LIGHT SNOW ACCUMULATION
WHERE LAKE EFFECT DOES EXIST...AS FLAKE SIZE WILL BE QUITE SMALL
WITH THE DGZ BASICALLY AT GROUND LEVEL. SOME POTENTIAL IS THERE FOR
SPOTS TO DIP BELOW -10F SUNDAY NIGHT PROVIDED WINDS AND CLOUDS
COOPERATE.

&&

.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 335 AM EST FRI JAN 30 2015

WE NOW RETURN YOU TO NORMAL WINTER WEATHER (THOUGH ARGUABLY THERE IS
NO SUCH THING AS "NORMAL WEATHER" IN NORTHERN MICHIGAN). BROAD UPPER
TROUGHING LOOKS TO RESIDE OVER MUCH OF THE EASTERN CONUS THROUGH THE
ENTIRE WORK WEEK...REINFORCED AT TIMES BY A COUPLE OF NORTHWEST FLOW
EMANATING SHORTWAVES THAT WILL DRAG SEVERAL COLD FRONTS THROUGH THE
REGION. TIMING AND PLACEMENT OF THESE FEATURES OF COURSE REMAINS A
CHALLENGE... AS IT OFTEN IS IN SUCH SETUPS...BUT A GENERAL CONSENSUS
WOULD PLACE ONE WAVE ARRIVING LATER TUESDAY AND ANOTHER SOMETIME ON
WEDNESDAY OR WEDNESDAY NIGHT. THE INITIAL WAVE DOES AT LEAST PEAK
SOME INTEREST GIVEN A PERSISTENT AND DECENT FGEN SIGNAL NOTED FOR A
FEW DAYS NOW SO SOMETHING TO WATCH. OUTSIDE OF SYNOPTIC SUPPORT...
SIMPLE STEP-DOWN TOWARD MUCH COLDER CONDITIONS ONCE AGAIN MANDATES
DAILY CHANCES FOR LAKE EFFECT SNOW SHOWERS...WITH TEMPERATURES
SOLIDLY BELOW NORMAL FOR THE FIRST WEEK OF FEBRUARY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 614 AM EST FRI JAN 30 2015

...LIGHT LAKE EFFECT AND BLOWING SNOW WANING...

STILL GUSTY NW WINDS AND VERY COLD AIR...ALONG WITH LIGHT LAKE
EFFECT SNOW SHOWERS (MBL/TVC) WILL CONTINUE TO WEAKEN THROUGH THE
MORNING AS HIGHER PRESSURE WORKS INTO THE REGION. BY LATER THIS
AFTERNOON AND EVENING...ONLY FLURRIES EXPECTED...WHICH SHOULD WORK
THEIR WAY BACK INTO PLN AS WINDS GRADUALLY SHIFT OUT OF THE WEST
LATER THIS AFTERNOON AND TONIGHT. GUSTIER WINDS FOR AWHILE LONGER
AT APN WILL CONTINUE TO BLOW AROUND SNOW AND KEEP VSBYS REDUCED.

SKIES WILL REMAIN HIGH MVFR/LOW VFR ACROSS NW LOWER...BUT A CORE
OF DRIER LOW LEVEL IS EXPECTED TO GRAZE APN...POSSIBLY SCATTERING
THEM OUT...POSSIBLY PLN FOR AWHILE THIS MORNING.

A DISTURBANCE ALOFT WILL ARRIVE OVERNIGHT...BRINGING A TOUCH OF
LIGHT SYSTEM SNOW...MAINLY PLN/APN. COULD SEE SOME VSBYS COME DOWN
WITH ENHANCED LAKE EFFECT.


&&

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

$$

UPDATE...JPB
NEAR TERM...SMD
SHORT TERM...LAWRENCE
LONG TERM...LAWRENCE
AVIATION...SMD



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