Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 160844
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
344 AM EST TUE DEC 16 2014

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 331 AM EST TUE DEC 16 2014

FORECAST CHALLENGES: ENDING THE FOG AND TRANSITIONING TO RAIN THEN
SNOW BY TONIGHT.

OVERVIEW...THE 500 MB LOWS IN THE CENTER OF THE COUNTRY ARE
BEGINNING TO COME TOGETHER WITH THE SOUTHERN LOW MOVING INTO N
ILLINOIS AND IS ASSOCIATED WITH THE SFC LOW THAT IS MOVING INTO THE
MICHIGAN.  THE NORTHERN LOW, WHICH IS MORE LIKE AN ELONGATED TROUGH
IS BEGINNING TO ROTATE INTO THE UPPER GREAT LAKES OUT OF THE
BOUNDARY WATERS REGION.

TODAY...RAIN AND LIGHT FOG WILL BE THE RULE AS THE RAIN BAND MOVES
NORTH AHEAD OF THE SFC LOW MIGRATING FROM E WISCONSIN TO S LOWER. AT
THE SAME TIME, THE 500 MB TROUGH IN THE BOUNDARY WATERS BEGINS TO
FALL IN LINE BEHIND THE INITIAL 500 MB LOW, WHICH BY 00Z, HAS BEGUN
TO LOSE ITS IDENTITY. IN THE MEAN TIME, BY 00Z, THE SFC LOW HAS
MOVED INTO SW ONTARIO PULLING THE COLDER AIR SOUTH OUT OF N ONTARIO.
TEMPERATURES, AFTER 18Z WILL BEGIN TO COOL THROUGH THE AFTERNOON.
HOWEVER, LOOKING AT THE MODEL SOUNDING, IT DOESN`T LOOK LIKE THE
LOWER LEVELS COOL ENOUGH UNTIL AFTER 00Z. SO RAIN WILL BE DOMINATE
INTO THE EARLY EVENING.

TONIGHT...ITS DURING THE LATER EVENING, BETWEEN 0Z AND 03Z THAT THE
LOW LEVELS REALLY COOL OFF, AND THAT THE SFC TEMPERATURES BEGIN TO
FALL BELOW THE MID 30S. THIS ALLOWS THE RAIN TO MIX WITH SNOW IN NW
LOWER, AND THEN CHANGE OVER BY 03Z, WHILE IN NE LOWER THE
TEMPERATURES FALL AFTER 03Z SO THAT THE MIX IN IN NE LOWER, AND THEN
ALL SNOW BY 06Z. THE 850 MB TEMPERATURES TAKE A BIT OF TIME TO FALL
OFF OVERNIGHT AS WELL WITH -5C AIR STILL PREDOMINATE IN NE LOWER BY
12Z. THE -10C AND COLDER AIR IS JUST GETTING INTO  NW LOWER BY 12Z.
WAS A LITTLE CONCERNED FOR MORE DRIZZLE/FZ DRIZZLE BASED ON THE DRY
AIR (700-500 MB LAYER RH <30%) IN PORTIONS OF NW LOWER, AND ALONG
THE M-55 CORRIDOR, BUT THE 850 MB TEMPERATURES HAVE FALLEN TO AROUND
-10C BY THEN SO THAT WE SHOULD STILL BE HAVING LIGHT SNOW WITH THE
500 MB LOW AS IT MIGRATES INTO THE UPPER GREAT LAKES.

&&

.SHORT TERM...(WEDNESDAY THROUGH FRIDAY)
ISSUED AT 331 AM EST TUE DEC 16 2014

...ANOTHER STRETCH OF QUIET WEATHER COMING...

PATTERN DESCRIPTION AND EVOLUTION:

WEAK FLOW ALOFT REGIME SOLIDLY IN PLACE ACROSS THE GREAT LAKES
WITHIN SPLIT FLOW BEING THE RULE. CURRENT UPPER LOW AND SHOT AT RAIN
CHANGING TO SNOW WILL DEPART EAST OF US WHILE A SLOW TRANSITION TO
RISING HEIGHTS/GENERAL RIDGING WILL BRING QUIETER WEATHER FOR THE
LATTER HALF OF THE WEEK. LATE IN THE PERIOD...STILL LOOKING FOR A
STRONGER NRN STREAM WAVE AND PACIFIC MOISTURE TO CROSS INTO THE
GREAT LAKES.

FORECAST CHALLENGES: AMOUNT OF SNOW FOR WEDNESDAY WITH TIMING AND
EVOLUTION OF CLEARING SKIES THURSDAY. THIS LEADS TO MINIMUM
TEMPERATURE CONCERNS FOR THURSDAY NIGHT (HOW CHILLY CAN WE GET?).
FINALLY...TIMING OF NEXT CHANCE OF PRECIPITATION AND TYPE FOR EARLY
NEXT WORK WEEK.

ASSOCIATED WEATHER:

WEDNESDAY: UPPER LOW STILL OVERHEAD WITH SFC AND MID LEVEL
TROUGHING/DEEPER MOISTURE WRAPPING FROM EASTERN UPPER...THROUGH NRN
LOWER THROUGH THE DAY. FORCING WEAKENS WITH TIME AND THE LOW LEVEL
CONVERGENCE FADES ALONG WITH MID LEVEL DEFORMATION. CLOUDY SKIES AND
DAMP WEATHER WILL BE THE THEME...BUT RATHER THAN RAIN...CAA WILL
ALREADY HAVE MADE A CHANGEOVER TO LIGHT SNOW. CAA STRONGEST ACROSS
NW LOWER FROM TVC SOUTH...WITH INVERSION HEIGHTS CLIMBING TO 4-5KFT
AND MUCH LOWER FURTHER NORTH ACROSS EASTERN UPPER...WITHIN TROWAL
(2KFT OR LESS). THUS...MORE OF A LAKE CONTRIBUTION TVC SOUTH. BEST
SNOWS WILL BE IN THE MORNING...WITH A 1-1.5 INCHES POSSIBLE...LEAST
NEARER SAGINAW BAY (A FEW TENTHS POSSIBLE). FORCING WANES FURTHER
THROUGH THE NIGHT WITH DEEPER DRIER AIR ARRIVING LATE. A COUPLE OF
TENTHS AT MOST...WITH MOISTURE FALLING OUT OF THE -10C ISOTHERM WITH
TIME. SKIES TO STAY FAIRLY CLOUDY WITH MINIMAL TEMPERATURE SWING.
RAISED MODEL SUGGESTIONS BY A DEGREE OF TWO. HIGHS IN THE UPPER
20S/LOW 30S...WITH LOWS IN THE LOW TO MID 20S IN NRN LOWER. COULD
SEE SOME TEENS LATE ACROSS EASTERN UPPER...WHERE SOME CLEARING COULD
OCCUR VERY LATE.

THURSDAY INTO FRIDAY: DEEPER DRIER AIR TAKES OVER...WITH SFC AND
UPPER LEVEL RIDGING SETTLING IN. MAYBE SOME VERY LIGHT SNOW/FLURRIES
EARLY THURSDAY MORNING...BUT CLOUDS WILL CONTINUE TO DEPART WITH
SUNSHINE GRADUALLY INCREASING FROM NORTH TO SOUTH...AS THE DRY AIR
PUNCHES INTO THE BL. SKIES WILL BECOME MOSTLY CLEAR/CLEAR THURSDAY
NIGHT WITH OVERALL GOOD SUNSHINE EXPECTED FOR FRIDAY. MAYBE SOME
SHALLOW GROUND FOG IN LOW LYING AREAS THURSDAY NIGHT. LOWS THEN IN
THE 10-20F RANGE FOR MOST. HIGHS BOTH DAYS IN THE UPPER 20S TO LOWER
30S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH MONDAY)
ISSUED AT 353 PM EST MON DEC 15 2014

HIGH PRESSURE WILL STILL BE CENTERED OVER MICHIGAN FRIDAY NIGHT
INTO SATURDAY...AND WILL BE THE MAIN FEATURE CONTROLLING OUR
RATHER QUIET WEATHER EXPECTED THROUGHOUT MUCH OF THE PERIOD AS
MAINLY DRY CONDITIONS AND TEMPS NEAR CLIMO DOMINATE.

TOWARD THE END OF THIS TIME FRAME...CONFIDENCE DECREASES
REGARDING THE TRACK...SPEED AND OVERALL STRENGTH OF A NORTHERN
STREAM WAVE EXPECTED TO DIVE SOUTHWARD OUT OF CANADA INTO THE
NORTHERN TIER OF THE CONUS. AT LEAST SOMETHING TO KEEP AN EYE ON
FOR EARLY NEXT WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 127 AM EST TUE DEC 16 2014

BEGINNING TO SEE AN END OF THE LOW VSBYS AS THE RAIN STARTS TO
SCOUR OUT THE MOISTURE. TVC IS AT 1SM AND APN AT 2 1/2SM WITH
MVFR VSBYS DOWNSTATE BEHIND THE LINE OF RAIN SHOWERS. PLN IS THE
PROBLEM AT THIS POINT AS THE SOUPY MASS HAS CONTINUED TO DROP THE
VSBY AND THE CIGS INTO THE LIFR CATEGORY FROM TIME TO TIME. AM
EXPECTING THE RAIN SHOWERS AND THE BETTER VSBYS TO MAKE ITS WAY TO
PLN OVER THE NEXT FEW HOURS.


&&

.MARINE...
ISSUED AT 331 AM EST TUE DEC 16 2014

WINDS TODAY WILL REMAIN VARIABLE AT LESS THEN 10 KNOTS THROUGH
THE MORNING, BUT WITH THE SFC LOW MOVING EAST INTO SE LOWER BY
18Z, THE PRESSURE GRADIENT WILL BEGIN TO TIGHTEN UP IN N LAKE
MICHIGAN. THIS WILL LEAD TO SMALL CRAFT ADVISORY WINDS AND WAVES
ALONG THE FROM NEAR GRAND TRAVERSE LIGHT TO SOUTH OF MANISTEE.
HOWEVER THAT DOESN`T LOOK TO BE THE CASE UNTIL AFTER 21Z. THE
WINDS WILL CONTINUE TONIGHT AND INTO WEDNESDAY AS THE GRADIENT
CONTINUES TIGHT. HOWEVER AS THE SFC LOW MOVES EAST WEDNESDAY NIGHT
THE GRADIENT RELAXES AND THE WINDS SHOULD DIMINISH.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EST
     WEDNESDAY FOR LMZ345-346.

LS...NONE.
&&

$$

NEAR TERM...JSL
SHORT TERM...SMD
LONG TERM...GILLEN
AVIATION...JSL
MARINE...JSL


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