FXUS63 KAPX 251831
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
131 PM EST FRI DEC 25 2009
.SYNOPSIS.../ISSUED AT 515 AM/
A STORM SYSTEM OVER MISSOURI...WILL SLOWLY DRIFT NORTH INTO IOWA
TODAY. AS THE SYSTEM STALLS OUT...A FRONTAL BOUNDARY WILL SURGE
NORTHEAST INTO LOWER MICHIGAN...PRODUCING WIDESPREAD RAINFALL
TODAY. SOME FREEZING RAIN REMAINS POSSIBLE IN THE HIGHER
TERRAIN OF NORTHERN MICHIGAN. THEN...THIS SYSTEM WILL SLOWLY ROTATE
INTO THE GREAT LAKES THROUGH SUNDAY WITH COLDER AIR FILTERING BACK
INTO THE REGION. THIS WILL LEAD TO PERIODS OF LIGHT SNOW SHOWERS
FROM TONIGHT THROUGH SUNDAY. SNOW SHOWERS WILL REMAIN POSSIBLE INTO
EARLY NEXT WORK WEEK...AS THE LAKE EFFECT MACHINE CRANKS UP AGAIN
WITH A SECONDARY SURGE OF COLD AIR ARRIVING ON MONDAY.
&&
.SHORT TERM.../ISSUED AT 130 PM/...THIS AFTERNOON
TEMPS THIS AFTERNOON HAVE WARMED INTO THE MID AND UPPER 30S ACROSS
MUCH OF NORTHERN MICHIGAN. TEMPERATURES OVER THE HIGHER TERRAIN...
HAVE WARMED ABOVE FREEZING TO AROUND 34/35 DEGREES. CURRENT SFC OBS
SHOWING PCPN IN THE FORM OF RAIN ACROSS THE CWA. EXPECT THE ABOVE
FREEZING TEMPS TO CONTINUE THROUGH THE REMAIN OF THE AFTN. THEREFORE
WILL CANCEL THE ADVISORY FOR NRN MI.
SWR
&&
.LONG TERM.../ISSUED AT 515 AM/...TONIGHT AND BEYOND
TONIGHT...THE STORM SYSTEM OCCLUDES THROUGH THE DAY...AND THE WARM
ADVECTIVE CHARACTERISTIC GETS CUT OFF/SHUNTED EAST OF THE REGION
(MORE QUICKLY ON THE GFS). DEEP MOISTURE CHANNEL ALONG/LEFT OF H8
LLJ LIFTS UP NORTH THROUGH THE NORTH WOODS...WHILE COLD ADVECTION
ARRIVES OVERNIGHT VIA SOUTHERLY WINDS. THIS PROCESS WILL ALLOW FOR
A PERIOD OF RAIN AND SOME FREEZING RAIN IN THE EVENING TO BECOME
MORE OF A SNOW CHANCE INTO THE OVERNIGHT HOURS. BEST RAIN WHILE
WARMER TEMPERATURES ARE HERE THOUGH. MINIMAL SNOW ACCUMULATIONS...
MAYBE A FEW SPOTS COULD SEE AN INCH...OTHERWISE LESS THAN THAT. ONE
CHANGE SEEN FROM LAST NIGHT'S DATA...MOISTURE IS A BIT DEEPER FOR
LESS CHANCE OF DRIZZLE. DON'T HAVE IT IN THE FORECAST RIGHT
NOW...BUT I DO HAVE IT IN THE BACK OF MY MIND.
THE WEEKEND...COLDER AIR WITH H8 TEMPS DROPPING INTO THE -10C TO
-12C RANGE...WHILE UPPER LOW DRIFTS ACROSS THE REGION. TOO
DIFFICULT TO TRY AND PINPOINT EXACT VORT/DEEPER MOISTURE TRACKS AT
THIS POINT. HOWEVER...PATTERN SUGGESTS THAT PERIODS OF LIGHT SNOW
ARE MORE THAN LIKELY. WILL CONTINUE TO RISE GOOD CHANCES OF SNOW
IN THE FORECAST...BUT EXPECT SOME LIKELY/CATEGORICAL WORDING IN
THE NEAR FUTURE.
LATER PERIODS...NOT MANY CHANGES...BUT NRN STREAM SHORTWAVE DIVING
IN MONDAY SHARPENS LOW LEVEL TROUGHING ACROSS THE REGION. WE ARE
LOOKING AT YET ANOTHER LIKELY PERIOD OF SNOW. COLDER AIR...WITH H8
TEMPS POSSIBLY DOWN TO -20C...SCRAPES BY MONDAY NIGHT WHILE AIR
MASS DRIES OUT. SURE CAN EXPECT ANOTHER PERIOD OF SNOW.
THE SNOWFALL OVER THE NEXT SEVERAL DAYS DOES NOT LOOK ALL THAT
IMPRESSIVE FOR ANYTHING SIGNIFICANT AT THIS POINT. SMD
&&
.MARINE.../ISSUED AT 515 AM/
EAST/SOUTHEAST WINDS INCREASE TO 35 TO 45 KTS TODAY...WITHIN
SHALLOW INSTABILITY OVER THE GREAT LAKES. GALES HAVE ALREADY
VERIFIED AT WHITEFISH BAY...NOT SURPRISING WITH THE SOUTHEAST
WIND COMPONENT. GALES WILL BE NO PROBLEM IN ALL NEARSHORE ZONES
INTO THE EVENING. AM CONCERNED ABOUT POTENTIAL STORM FORCE WINDS
WITHIN THE STRAITS REGION DUE TO COASTAL CONVERGENCE AND SOME
CHANNELED/FUNNELED AIR FLOW. EXPANDED GALES INTO WHITEFISH
BAY/SAINT MARY'S...AND EXTENDED THE TIME FOR GALES INTO THE
EVENING MOST ALL AREAS. SMD
&&
.AVIATION.../ISSUED AT 130 PM/...VALID FOR 18Z TAFS
WIDESPREAD RAIN OVER NRN MI THIS AFTN...IS IN RESPONSE TO STORM
SYSTEM MOVING INTO IOWA. CURRENT IFR/MVFR CIGS AND VSBYS AT NRN MI
TAF SITES...EXPECTED TO CONTINUE INTO THIS EVENING DUE TO RAIN AND
WARM AIR MOVING OVER SNOWPACK. IFR/MVFR CIGS AND VSBYS EXPECTED TO
SLOWLY IMPROVE OVERNIGHT AND SATURDAY MORNING...AS COOLER AND DRIER
AIR PUSHES INTO THE REGION FROM SOUTHERN MICHIGAN. RAIN WILL
TRANSITION TO SNOW THIS EVENING/TONIGHT...WITH ANY LINGERING PCPN
AFT 06Z THROUGH 18Z SATURDAY IN THE FORM OF SNOW.
SWR
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WARNING UNTIL 4 AM EST SATURDAY FOR LMZ323-341-342-344.
GALE WARNING UNTIL 5 PM EST THIS AFTERNOON FOR LMZ345-346.
LH...GALE WARNING UNTIL 4 AM EST SATURDAY FOR LHZ345>349.
LS...GALE WARNING UNTIL 4 AM EST SATURDAY FOR LSZ321-322.
&&
$$
