FXUS63 KAPX 111120
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
620 AM EST FRI DEC 11 2009
.SYNOPSIS.../ISSUED AT 455 AM/
LAKE EFFECT SNOW SHOWERS WILL CONTINUE THROUGH TONIGHT ACROSS
NORTHERN MICHIGAN AS A RATHER COLD AIR MASS REMAINS ENTRENCHED OVER
THE REGION. SNOW SHOWERS ARE EXPECTED TO WIND DOWN SATURDAY AS
A RIDGE OF HIGH PRESSURE BUILDS INTO THE STATE AND WARMER AIR BEGINS
TO RETURN. HOWEVER...THIS PUSH OF WARMER AIR WILL ALSO RESULT IN A
RENEWED CHANCE FOR MORE WIDESPREAD LIGHT SNOW FOR THE LATTER HALF OF
THE WEEKEND...WITH SEVERAL ADDITIONAL CHANCES FOR SNOW THROUGH THE
FIRST HALF OF THE COMING WORK WEEK. THEREAFTER...IT APPEARS
INCREASINGLY LIKELY ANOTHER SURGE OF ARCTIC AIR AND PLENTIFUL LAKE
EFFECT SNOWS WILL MAKE AN APPEARANCE FOR THE LATTER HALF OF NEXT
WEEK.
&&
.SHORT TERM.../ISSUED AT 455 AM/...TODAY
CURRENTLY...WEAK SHORTWAVE TROUGH HAS LIFTED THROUGH THE NORTH
WOODS AND HAD PROVIDED AN UPTICK IN THE LES. THE BANDS WIGGLED A
BIT...GOING MORE SW PRIOR TO THIS WAVE...NOW IN THE PROCESS OF
SETTLING IN ON MORE OF A 270-280 REGIME. THE BEST BANDS ARE
WORKING ON CHIPPEWA COUNTY NORTH OF PARADISE...AND FAR NW LOWER
DOWNWIND OF LITTLE TRAVERSE BAY. TEMPERATURES ARE COLD...IN THE
SINGLE DIGITS TO LOW TEENS...WHILE WINDS ARE IN THE 15-25 MPH
RANGE. WIND CHILLS ARE GENERALLY IN THE SINGLE DIGITS BELOW ZERO.
SO QUITE THE CHILLY NIGHT...AND STILL RATHER NASTY WITH THE
FALLING SNOW AND BLOWING/DRIFTING SNOW.
THROUGH THE DAY...AFOREMENTIONED SHORTWAVE INDUCED STRONGER
CONVERGENCE ACROSS EASTER LAKE SUPERIOR...AS SEEN BY DOMINANT
SOUTHERN SNOW BAND...WHILE MORE GENERAL MULTI-BAND CONVECTION
PRESENT ACROSS NRN LOWER. AS SHORTWAVE CONTINUES TO LIFT NORTH
THIS MORNING...MORE RIDGING ALOFT ARRIVES WITH LOST CONVERGENCE
ACROSS EASTERN LAKE SUPERIOR. UNIDIRECTIONAL 1000-850MB FLOW SETS
UP OUT OF THE WEST (260-280) FOR THE DAY....WHICH STAYS BRISK AT
25-30KTS. HERE ARE THE OTHER PARTICULARS FOR LES...H8 TEMPS -18C
TO -20C...GRADUALLY DEPARTING RH ALOFT WITH INCREASING SUBSIDENCE
AND LOWERING INVERSION HEIGHTS (7500FT/5500FT TO 6500/4500FT).
STILL SEEING OMEGA/LIFT NAILING THE DGZ...AND WITH STILL
RESPECTABLE INVERSION HEIGHTS...MODERATE TO HEAVY LES REMAINS THE
EXPECTED OUTCOME WHERE IN LONGEST FETCHES AND WHERE BANDS CAN
PERSIST THROUGH MOST OF THE DAY. THIS MAY ONLY OCCUR FOR THE
MORNING HOURS ACROSS PARADISE NORTHWARD OF EXTREME NW CHIP
COUNTY...EVEN THOUGH THAT DOMINANT BAND LOOKS VERY IMPRESSIVE. HAD
TO LOWER SNOW AMOUNTS JUST A TOUCH THERE...ALTHOUGH UP TO 5
INCHES STILL PROBABLE. DECIDED TO END WINTER STORM WARNING SINCE
THE SNOW IS ONLY AFFECTING A MINOR PORTION OF THE COUNTY.
ACROSS NRN LOWER...SOLID 3-5 INCHES IN FAR NW LOWER...HIGHEST
AMOUNTS FOCUSED ALONG M-68 FROM LITTLE TRAVERSE BAY THROUGH
CHEBOYGAN COUNTY. WILL RIDE THE CURRENT WARNINGS AND ADVISORIES
THROUGH THE MORNING...AS COLD/GUSTY WINDS AND FALLING...BLOWING..
DRIFTING...ACCUMULATING SNOW WILL CONTINUE TO BRING HAZARDOUS
WINTER/TRAVEL CONDITIONS. SMD
&&
.LONG TERM.../ISSUED AT 455 AM/...TONIGHT AND BEYOND
TONIGHT...LAKE EFFECT SNOW SHOWERS WILL PERSIST TONIGHT AS WINDS
SHIFT FROM WESTERLY TO SOUTHWEST. ACCUMULATIONS WILL BE MUCH
LIGHTER...AS LES CONDITIONS BECOME MUCH MORE HOSTILE. CONTINUED
LOWERING INVERSION WITH SUBSIDENCE AND DEPARTING MOISTURE WILL
COUPLE WITH INCREASING ANTICYCLONIC FLOW AS SFC HIGH PUSHES INTO
THE REGION. WILL HAVE A COUPLE OF INCHES FOCUSED MORE AROUND
WESTERN EMMET/CHARLEVOIX COUNTIES. AWAY FROM THE LAKES
INFLUENCE...MORE CLEARING EXPECTED WITH LOWS DIPPING INTO THE
SINGLE DIGITS.
SATURDAY THROUGH SUNDAY...TOUGH TO DISCERN HOW THIS TIME FRAME
WILL PLAY OUT...AS NRN STREAM ENERGY LOOKS TO AFFECT MAINLY
ONTARIO...WHILE SRN JET STREAM EJECTS SHORTWAVE ACTIVITY OUR WAY
SATURDAY NIGHT AND SUNDAY. LIKELY SOME WEAK LES IN SW FLOW REGIMES
POSSIBLY ENHANCED LATE IN THE DAY SATURDAY AHEAD OF LEAD SRN
STREAM WAVE...PROVIDED THAT LOW LEVEL WARMING DOESN'T TRY AND
STABILIZE THE LAKES. BY SATURDAY NIGHT...WAA/ISENTROPIC ASCENT
ARRIVES TO BRING SOME GENERAL LIGHT SYSTEM SNOW TO THE REGION WITH
MAYBE SOME SHALLOW LAKE HELP. THE LIGHT SNOW EJECTS OUT OF HERE
SUNDAY...LEAVING BEHIND AN INCH OR TWO PERHAPS. COULD EVEN BE
LOOKING AT SOME DRIZZLE/FREEZING DRIZZLE. NOTHING VERY DEFINED AT
THE MOMENT...BUT TEMPERATURES SHOULD UNDERGO A DECENT WARMING.
HIGHS RISE INTO THE MID 20S/NEAR 30 SATURDAY AND INTO THE LOWER
HALF OF THE 30S FOR SUNDAY.
SUN NIGHT THRU TUE NIGHT...GIST OF GOING FCST LOOKS PRETTY
GOOD...WITH PATTERN BRIEFLY RELAXING BUT OVERALL WX NOT SETTLING
DOWN MUCH ACRS NORTHERN MICHIGAN. AS IS TYPICALLY THE CASE UP THIS
WAY...PATTERN RELAXATION/WARM ADVECTION REGIMES USUALLY LEAD TO MORE
SNOW/PRECIP CHANCES AND THIS NO EXCEPTION. APPEARS A BRIEF BREAK IN
THE ACTION ON TAP SUN NIGHT WITH WEAK LOW LEVEL RIDGE AXIS BRANCHING
THRU THE REGION AND FLOW REGIME QUITE ANTICYCLONIC AND CONVOLUTED.
THEREAFTER...00Z GUIDANCE SUITE LATCHING ONTO NEXT SHORTWAVE
EMERGING FROM THE FOUR CORNERS AREA AND HEADING TOWARD THE NORTHERN
GREAT LAKES LATER MONDAY...DRIVING SOME SORT OF SFC RESPONSE (LOW
PRESSURE) INTO NORTHERN MICHIGAN. RATHER GOOD AGREEMENT REGARDING
THIS FEATURE AT THIS POINT...BUT COULD BE SOME PTYPE ISSUES ACRS THE
SOUTH GIVEN PROGGED RATHER HEALTHY SURGE OF WARM ADVECTION. WILL
LEAVE GOING CHANCE POPS INTACT AT THIS POINT BUT CAN FORESEE NEED TO
BUMP TOWARD LIKELY PENDING CONTINUED GUIDANCE AGREEMENT.
THEREAFTER...NEXT SHOT OF QUITE CHILLY AIR SET TO ROLL INTO THE AREA
TUE/TUE NIGHT...PERHAPS ON THE HEELS OF CLIPPER SYSTEM TO DELIVER
SOME LIGHTER SNOW EARLY TUESDAY. GOING LIKELY LAKE EFFECT POPS TUE
NIGHT AND BEYOND LOOK GREAT. TEMPS HANGING NEAR CLIMO EARLY THEN
HEADED TOWARD THE DEEP FREEZE INTO MIDWEEK.
LAWRENCE
&&
.MARINE.../ISSUED AT 455 AM/
SLIGHT DIURNAL DECREASE IN THE WINDS ATTM TO BELOW GALE CRITERIA.
HOWEVER...HIGH INSTABILITY OVER THE LAKES LIKELY STILL PRODUCING
GALES OVER THE NEARSHORE WATERS. PLUS...WITH MIXING DURING THE
DAY...GALES LIKELY TO PERSIST THROUGH THE DAY. WINDS DO WEAKEN A
TOUCH TONIGHT...SO WILL KEEP HEADLINES AS THEY ARE. CONDITIONS
WILL STILL BE RATHER ROUGH...WITH SMALL CRAFT ADVISORY CRITERIA
TONIGHT THROUGH AT LEAST SATURDAY NIGHT. LAKE EFFECT SNOW SHOWERS
WILL ONLY ADD TO THE NASTY CONDITIONS...ALTHOUGH A DOWNWARD TICK
IN THE INTENSITY OF THE SNOW IS EXPECTED BY SATURDAY. SNOW CHANCES
RETURN SAT NIGHT-SUNDAY...WITH LAKE EFFECT FOR THE NEXT WORK WEEK.
SMD
&&
.AVIATION.../ISSUED AT 616 AM/...VALID FOR 12Z TAFS
LAKE EFFECT SNOW SHOWERS AND GUSTY WINDS WILL CONTINUE TO IMPACT
MUCH OF NW LWR MICHIGAN WITH SNOW AND BLOWING AND DRIFTING SNOW
THROUGH THIS EVENING. CONDITIONS WILL DROP TO MVFR AND SOMETIMES
IFR WITHIN SNOW BANDS...WITH BRIEF PERIODS OF LIFR WITHIN HEAVY
SNOW BANDS. THE WORST CONDITIONS WILL BE AROUND PLN AND TVC INTO
THIS EVENING...WITH PLN BEING IMPACTED LATE TONIGHT...WHILE APN
BECOMES VFR WITH CLEAR SKIES. SMD
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MIZ018-020-023-
025>028-031-032.
WINTER STORM WARNING UNTIL 5 PM EST THIS AFTERNOON FOR MIZ016-
017-019-021-022.
LM...GALE WARNING UNTIL 5 PM EST THIS AFTERNOON FOR LMZ323-341-342-
344>346.
LH...GALE WARNING UNTIL 5 PM EST THIS AFTERNOON FOR LHZ345>349.
LS...GALE WARNING UNTIL 5 PM EST THIS AFTERNOON FOR LSZ321-322.
&&
$$
