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000
FXUS63 KAPX 040228
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
928 PM EST MON MAR 3 2014

.SYNOPSIS...
ISSUED AT 358 PM EST MON MAR 3 2014

INCREASED CLOUDINESS AHEAD OF A WEAK LOW PRESSURE ARRIVING LATE
TONIGHT INTO TUESDAY WILL PROVIDE A BRIEF ROUND OF LIGHT
SNOW...BEFORE THINGS AGAIN DRY OUT INTO MIDWEEK WITH STRONG CANADIAN
HIGH PRESSURE OVERHEAD. ANOTHER ROUND OF LIGHT SNOW IS POSSIBLE TO
WRAP UP THE WORK WEEK...SETTING THE STAGE FOR A RETURN TO DRY BUT
STILL CHILLY CONDITIONS JUST IN TIME FOR NEXT WEEKEND.

&&

.UPDATE...
ISSUED AT 928 PM EST MON MAR 3 2014

IN A SOMEWHAT SURPRISING (AND ATYPICAL) DEVELOPMENT...MOST CHANGES
TO MIN TEMPS OVER THE PAST COUPLE OF HOURS HAVE BEEN UPWARD. THIS
IS ESPECIALLY THE CASE ALONG THE I-75 CORRIDOR IN NORTHERN
LOWER...WHERE PLACES LIKE PLN/GLR HAVE REFUSED TO DECOUPLE THIS
EVENING. THAT LEAVES CURRENT TEMPS COMFORTABLY IN SINGLE DIGITS
ABOVE ZERO...WHICH THICKER MID/HIGH CLOUDS KNOCKING ON DOOR. WOULD
NOT PRECLUDE HTL FROM PERHAPS DROPPING TO SLIGHTLY BELOW 0F...BUT
WILL BE A STRUGGLE FOR THE REST OF N CENTRAL LOWER. HAVE NO
PROBLEM WITH NE LOWER MIN TEMPS...WITH APN ALREADY 0F. NW LOWER
WAS TWEAKED UPWARD A DEGREE OR TWO...FEW CHANGES IN EASTERN UPPER.

VERY SLIGHTLY SLOWED THE ONSET OF BETTER SNOW TONIGHT. IT/S COMING
PER UPSTREAM TRENDS...BUT OUR ANTECEDENT AIRMASS IS RIDICULOUSLY
DRY (00Z APX SOUNDING PWAT 0.06 INCHES...850MB DEW POINT
DEPRESSION 40C...CURRENT MBL DEW POINT -11F). LOOKING AT BETTER
FGEN-RELATED RETURNS UPSTREAM...THEY ARE ON TARGET TOWARD
LEELANAU/GRAYLING AREAS...PERHAPS A SMIDGE NORTH OF SHORT-TERM NAM
PROGS. HAVE NO PROBLEM SEEING THOSE AREAS PICK UP AN INCH OR SO
OVERNIGHT. WILL DECREASE SNOWFALL ALONG THE NORTH FLANK OF
THIS...ESPECIALLY ALONG A PLN-APN AXIS.

UPDATE ISSUED AT 637 PM EST MON MAR 3 2014

SKY COVER GRIDS ADJUSTED TO ACCOUNT FOR SLOWER INCREASE IN HIGH
CLOUDS INTO THE REGION...BUT ALSO FOR THE RATHER NARROW BAND OF
LAKE-INDUCED STRATOCU DEVELOPING NE-WARD INTO TVC/PLN. NO CHANGES
TO TEMPS JUST YET...PRESSURE GRADIENT ISN/T TERRIBLY RELAXED (WITH
GUSTS TO 20 MPH STILL IN THE STRAITS REGION). BETWEEN THAT AND THE
INCOMING CLOUD COVER...AM NOT CONVINCED TEMPS NEED TO LOWERED...
BUT SUSPECT THAT MAY BE NEEDED LATER ON.

&&

.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 358 PM EST MON MAR 3 2014

...LIGHT SNOW TO OVERSPREAD REGION TONIGHT...

IMPACTS: MINOR. LOCALLY SLICK ROADS WITH LIGHT SNOW LATE TONIGHT.

CONFIDENCE:  HIGH FOR LIGHT SNOW ACROSS NRN LOWER MI TONIGHT.
MODERATE FOR LIGHT SNOW ACROSS ACROSS ERN UPPER MI LATE TONIGHT.

OVERALL EVOLUTION AND EXPECTED WEATHER: HIGH PRESSURE RESPONSIBLE
FOR TODAY/S BRILLIANT SUNSHINE WILL PUSH EWD ACROSS THE LOWER GREAT
LAKES THIS EVENING...THOUGH SADLY ITS INFLUENCE ON OUR WEATHER WILL
QUICKLY DIMINISH AS A WEAK WEATHER DISTURBANCE APPROACHES FROM THE
WEST. THIS MID LEVEL SHORT WAVE TROUGH /CURRENTLY OVER N DAKOTA/
WILL MOVE ACROSS UPPER MS VALLEY AND INTO THE GREAT LAKES LATE
TONIGHT. AS SAID SURFACE HIGH MOVES EAST WINDS WILL BACK TO SW...AND
THIS WILL SUPPORT WEAK ISENTROPIC ASCENT BEGINNING THIS EVENING. IN
ADDITION...QG SUPPORT FOR ASCENT /ALBEIT MODERATE/ WILL BE ON THE
INCREASE AS SHORT WAVE APPROACHES LATE. WILL BE INTERESTING TO SEE
RESPONSE TO MID LEVEL FGEN THAT WILL EXTEND W-E ACROSS FAR NRN LOWER
MI LATE TONIGHT. IF FGEN RESPONSE IS SUFFICIENTLY STRONG...SNOW
COVERAGE COULD DROP OFF DRAMATICALLY NORTH OF THE STRAITS - WITH
LITTLE/NO ACCUMULATION.

IN GENERAL...AROUND AN INCH OF NEW SNOW IS EXPECTED ACROSS NRN LOWER
MI TONIGHT /MAINLY LATE/. A BIT MORE IS POSSIBLE ACROSS NW LOWER
/IN THE VICINITY OF MBL-TVC/ GIVEN LONGER SNOW DURATION AND POSSIBLE
BOOST AS SW WINDS CROSS LIMITED OPEN WATER ACROSS CENTRAL AND
NORTHERN LAKE MICHIGAN.

WITH MAINLY CLEAR SKIES AND LIGHT WINDS EARLY THIS EVENING...TEMPS
SHOULD DROP OFF QUICKLY. THEN...INCREASING CLOUDS FROM MID-LATE
EVENING ONWARD WILL CONTRIBUTE TO A SLOW INCREASE IN TEMPS/WINDS.
LOWS TEMPS /AROUND MIDNIGHT/ WILL FALL TO AROUND 5F ALONG/WEST OF
US-131 CORRIDOR...AND FROM ZER

.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 358 PM EST MON MAR 3 2014

HIGH IMPACT WEATHER POTENTIAL: SOME SLICK TRAVEL TO START THE PERIOD
TUESDAY MORNING /WITH LIGHT SNOW ACCUMULATIONS/.  OTHERWISE...A VERY
QUIET WEATHER PERIOD EXPECTED WITH NO HIGH IMPACT WEATHER EXPECTED.

PATTERN SUMMARY: CONTROLLING FEATURES FOR THIS FORECAST PERIOD ARE
THOSE THAT WE HAVE SEEN FOR MUCH OF THE WINTER.  FIRST...ONGOING
RIDGING OVER THE EASTERN PACIFIC...OCCASIONALLY EDGING EAST INTO
WESTERN NOAM. PERSISTENT TROUGHING REMAINS ENTRENCHED EAST OF THIS
WITH RIDGING DOWNSTREAM OVER THE CENTRAL ATLANTIC.  WHILE THE
INTENSITIES OF EACH OF THESE FEATURES HAS EBBED AND FLOWED...THEIR
POSITIONS HAVE REMAINED NEARLY LOCKED.  RECENT HOVMOLLER ANALYSES
SUGGEST NO CHANGE IN THESE LARGE SCALE FEATURES...AND A LOOK AT
RECENT DETERMINISTIC AND ENSEMBLE GUIDANCE DOES NOT DISAPPOINT...
PROVIDING MORE OF THE SAME FOR THE UPCOMING LONG TERM FORECAST
PERIOD.  FOR THOSE OF YOU LOOKING FOR SPRINGTIME WARMTH...THERE IS
THE GOOD NEWS THAT THE OVERALL BACKGROUND PATTERN IS SLOWLY
WARMING...WITH THIS MOST RECENT BOUT OF ARCTIC AIR HELPING TO
BASICALLY USE UP THE COLDEST OF THE AIR ON THIS SIDE OF THE
GLOBE...WITH FUTURE AIRMASSES COLDER THAN NORMAL...BUT WARMER THAN
RECENTLY...AND PERHAPS NEARING CLIMATOLOGICAL VALUES BY THE END OF
THIS FORECAST PERIOD.

WITH THE PERSISTENCE OF THIS LARGE SCALE PATTERN...WE CAN EXPECT
NORTHERN STREAM DOMINANCE...SUGGESTING FAST MOVING...MOISTURE
STARVED SYSTEMS...WITH GENERALLY COLDER THAN NORMAL TEMPERATURES.
THERE ARE SOME INDICATIONS THAT PATTERN FLATTENS FOR A TIME AS WE
END THIS PERIOD EARLY NEXT WEEK...BUT WE SAID THIS SAME THING A WEEK
AGO...AND...WELL...ITS STILL RATHER CHILLY!  SO...STAY TUNED FOR THE
POTENTIAL FOR SOME WARM UP EARLY NEXT WEEK AS CONFIDENCE /HOPEFULLY/
GROWS.

NOW FOR SOME DETAILS...

TUESDAY: WEAK SHORTWAVE ARRIVES IN TANDEM WITH RIGHT ENTRANCE REGION
OF AN EXITING 120KT JET STREAK ON THE 1.5 PVU SURFACE.  THIS AND
SOME WEAK SIGNAL IN THE MID LEVEL FRONTOGENESIS FIELD SHOULD HAVE NO
PROBLEM PRODUCING AN AREA OF LIGHT SNOWFALL...MUCH LIKE WHAT IS SEEN
THIS AFTERNOON OVER MINNESOTA AND NORTH DAKOTA.  WHILE THE QG
FORCING FOR ASCENT IS MODEST...THE DGZ IS WELL-PLACED...SUGGESTING
GOOD RATIOS FOR THE LIMITED AMOUNT OF QPF /ON THE ORDER OF 20:1/.
PRECIPITABLE WATERS REACH JUST OVER CLIMATOLOGICAL VALUES FOR MARCH
/0.25"/.  SREF PLUMES SHOW EVENT TOTAL QPF AROUND 0.15" FOR THE
SOUTHERN HALF OF NORTHERN LOWER...WITH LESSER AMOUNTS FURTHER NORTH
AS ONE MOVES AWAY FROM THE DEEPEST MOISTURE.  GFS LOOKS TOO MOIST
/0.25"/ GIVEN THE WEAK NATURE OF FORCING...WITH NO STRONG FGEN
SIGNAL TO HELP CONCENTRATE SNOWFALL INTO A STRONGER BAND.  STILL...
WITH GOOD RATIOS...WE COULD CERTAINLY SQUEEZE OUT 1-2" /ISOLATED 3"/
OF SNOW...MOST OF IT ON THE GROUND BY NOON.  WEAK LLEVEL CONVERGENCE
CONTINUES OVER NORTHERN LOWER IN THE AFTERNOON ALLOWING SOME LIGHT
SNOWS TO CONTINUE GIVEN...AGAIN...THE DGZ WELL PLACED FOR MAXIMIZING
SNOWFLAKE PRODUCTION DESPITE SHALLOW LIFT.  THEREFORE...EXPECT SOME
LIGHT SNOW/FLURRIES TO CONTINUE THROUGH THE AFTERNOON...BUT LITTLE
ADDITIONAL ACCUMULATION.  AS FOR TEMPERATURES...T9 AROUND -13C
INDICATE AN UPPER BOUND AROUND 20F...WITH MOST LOCATIONS LIKELY IN
THE UPPER TEENS GIVEN CLOUD COVER/SNOWFALL.  STILL...A GOOD BOOST
UPWARD FROM TODAY/S FRIGID READINGS.

WEDNESDAY: PRIMARY COLD FRONT SETTLES SOUTH OF THE REGION WITH HIGH
PRESSURE OOZING IN FROM THE NORTH.  INTERESTING FEATURE OF NOTE IS
MID LEVEL SHORTWAVE THAT ARRIVES BEHIND DEPARTING FRONT...AND COAXES
A WEAK RESPONSE IN THE SURFACE PRESSURE FIELD ACROSS NORTHERN
MICHIGAN.  AS MENTIONED BY THE OVERNIGHT FORECASTER...THIS TAKES THE
FORM OF AN INVERTED TROUGH DOWN THE SPINE OF NORTHERN LOWER...WITH
AN IMPLIED BAND OF ENHANCED LLEVEL CONVERGENCE.  INTERESTINGLY...
THIS LLEVEL CONVERGENCE AND LIFT IS ALSO COLLOCATED WITH THE DGZ.
SO...HAVE SOME CONCERNS FOR SOME LIGHT...FLUFFY SNOW POTENTIAL
PARTICULARLY OVER SOUTHERN PORTIONS OF THE CWA...CLOSEST TO THE
DEPARTING DEEP MOISTURE PLUME.  WILL ADD CHANCE POPS IN WITH THIS
PACKAGE...BUT EVEN IF THIS MATERIALIZES...WE ARE NOT LOOKING AT ANY
MORE THAN AN ADDITIONAL COATING OF SNOW. BY WEDNESDAY NIGHT...DRIER
AIR AND QG FORCING FOR DESCENT SHOULD SQUASH ANY ONGOING LIGHT SNOWS
WITH SOME CLEARING POSSIBLE.  FOR WEDNESDAY...T9S IN THE LOW MINUS
TEENS SUGGEST HIGHS IN THE UPPER TEENS TO LOWER 20S...IN GOOD
AGREEMENT WITH THE CURRENT MODEL CONSENSUS. WITH AT LEAST PARTIAL
CLEARING WEDNESDAY NIGHT...LOWS FALLING BACK TOWARDS ZERO SEEM VERY
PLAUSIBLE.

THURSDAY: MOISTURE CONTINUES TO SCOUR OUT WITH BUILDING SUBSIDENCE
INVERSION BENEATH ARRIVING HIGH PRESSURE SYSTEM.  THE DAYTIME
CERTAINLY LOOKS DRY...WITH SOME CLOUD COVER CONCERNS BOTH FROM
1-POTENTIAL LINGERING STRATUS BENEATH THE SUBSIDENCE INVERSION AND
2-INCREASING UPPER LEVEL CLOUDINESS LATE IN THE DAY AS NEXT FRONTAL
SYSTEMS BEGINS TO PUSH TOWARDS NORTHERN MICHIGAN.  NAM SEEMS A
LITTLE TOO AGGRESSIVE WITH LLEVEL MOISTURE THROUGH THE
DAY...PARTICULARLY WITH A FROZEN LAKE HURON...AND THEREFORE EXPECT
ANY CLOUDS BENEATH THE SUBSIDENCE INVERSION TO BE NO THICKER THAN
SCATTERED.  THIS...COMBINED WITH AFOREMENTIONED LATE DAY UPPER LEVEL
CLOUDINESS SUGGESTS A PARTLY SUNNY DAY FOR MOST LOCATIONS.  T9
MODERATES SLIGHTLY TO JUST BELOW -10C...WHICH...WITH SOME SUNSHINE
SHOULD ALLOW HIGHS TO MODERATE INTO THE 20S UNDER LIGHT SOUTH TO
SOUTHEAST WINDS.

THURSDAY NIGHT THROUGH MONDAY:

DESPITE THE FAST-MOVING NATURE OF SYSTEMS IN THE NORTHWEST
FLOW...THE GFS/ECMWF ARE IN RATHER GOOD AGREEMENT ON THE PASSAGE OF
A COLD FRONT THROUGH THE REGION ON THURSDAY NIGHT AND FRIDAY.
DESPITE A VERY DRY ANTECEDENT AIRMASS...PWAT VALUES NEARING 0.5"
MAKE A RUN AT THE CWA AHEAD OF THIS BOUNDARY IN THE WARM ADVECTION
REGIME.  AGREEMENT CONTINUES TO SLOWLY BRING BUILDING CONFIDENCE OF
OCCURRENCE...AND WILL BUMP POPS INTO THE HIGH CHANCE CATEGORY THIS
AFTERNOON.  GEFS PROBS REACH NO HIGHER THAN 0.1 PER 12HR...IN
AGREEMENT WITH A NORTHERN STREAM SYSTEM THAT HAS ACCESS TO LIMITED
MOISTURE.  THUS...NO MORE THAN A 1-3" SNOWFALL APPEARS POSSIBLE AT
THIS TIME. GIVEN INCREASING CLOUDS AND WARM ADVECTION...SHOULD SEE
LOWS A GOOD BIT WARMER THAN PREVIOUS NIGHTS...LIKELY REACHING NO
LOWER THAN 10F THROUGHOUT THE CWA.  ONLY POTENTIAL CAVEAT TO THIS IS
OVER NE LOWER WHERE...WITH DEPARTING HIGH PRESSURE...ANY CLEAR SKIES
IN THE EVENING WILL LEAD TO RAPIDLY FALLING TEMPERATURES.  AT THIS
TIME...EXPECT CLOUD COVER TO BE THICK ENOUGH QUICK ENOUGH TO
PRECLUDE THIS FROM HAPPENING. HIGHS FRIDAY WILL LIKELY MAKE A RUN AT
30F AS T9S WARM TO -7C...BUT ALSO TAKING INTO ACCOUNT SOME
CLOUDS/PRECIPITATION.

BEYOND THIS SYSTEM...HIGH PRESSURE LOOKS TO BUILD INTO THE GREAT
LAKES REGION FOR THE WEEKEND...WITH THE MORE ACTIVE STORM TRACK
REMAINING /MUCH LIKE IT IS TODAY/ OVER THE OHIO VALLEY AND POINTS
SOUTH.  T9S REMAIN AT OR A LITTLE BELOW -10C THROUGH THE
WEEKEND...WHICH SUGGESTS A STARTING POINT FOR HIGHS SOMEWHERE IN THE
MID 20S. WILL HAVE TO BE ON THE WATCH FOR ANOTHER CHILLY
NIGHT...MOST LIKELY SATURDAY NIGHT...WITH SNOWPACK...LIGHT
WINDS...AND POTENTIALLY CLEARING SKIES.  WENT BELOW MODEL CONSENSUS
FOR THIS PERIOD...BUT TEMPS WILL NEED FURTHER DOWNWARD ADJUSTMENT IF
CURRENT /WELL-AGREED UPON/ SETUP HOLDS.  BEYOND THIS...AS MENTIONED
ABOVE...THERE ARE SOME SIGNS THAT MILDER AIR LOOKS TO BRIEFLY PUSH
IN TO THE REGION BY EARLY NEXT WEEK.  NOT GOING TO GET TOO EXCITED
ABOUT THIS THAT FAR OUT...BUT WILL TREND TEMPERATURES TO JUST BELOW
CLIMATOLOGY TO END THE PERIOD MONDAY.  AS FOR PRECIPITATION
CHANCES...BOTH THE GFS/GEFS/ECMWF SHOW SOME SIGNALS FOR ANOTHER WEAK
FRONTAL SYSTEM BY MONDAY...THEREFORE SEE NO REASON TO DEVIATE FROM
CLIMATOLOGICAL CHANCE POPS FOR SNOW TO END THIS FORECAST PERIOD.
STILL...PATTERN SUGGESTS THAT ANY SNOW WOULD GENERALLY BE LIGHT.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 637 PM EST MON MAR 3 2014

MVFR CIGS TVC/MBL/TVC THIS EVENING. -SN DEVELOPING
OVERNIGHT...WITH PERIODS OF IFR VSBYS INTO TUESDAY MORNING.

HIGH PRESSURE OVER THE SOUTHERN GREAT LAKES WAS KEEPING THE AREA
CLEAR FOR MOST OF THE DAY. HOWEVER...SOME LAKE-INDUCED MVFR CIGS
HAVE MADE INROADS INTO NW LOWER MI LATE THIS AFTERNOON...AND WILL
CONTINUE THRU AT LEAST MUCH OF THE EVENING. OVERNIGHT...A FAST-
MOVING DISTURBANCE ARRIVES FROM THE WEST...WITH INCREASING MID-
HIGH CLOUDS GIVING WAY TO -SN. VSBYS IN THE 1-3SM RANGE EXPECTED
INTO TUESDAY MORNING. MVFR CIGS SHOULD LINGER INTO AFTERNOON EVEN
AFTER -SN EXITS AND VSBYS IMPROVE.

LIGHTISH WESTERLY WINDS THRU THE FORECAST.


&&

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

&&

$$

UPDATE...JZ
SYNOPSIS...TL
SHORT TERM...BS
LONG TERM...ARNOTT
AVIATION...JZ