FXUS63 KMQT 101754 AAC
AFDMQT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MARQUETTE MI
1255 PM EST THU DEC 10 2009
UPDATED AVIATION SECTION FOR 18Z TAFS
.UPDATE... /ISSUED 1215 PM EST/
UPDATED WINTER WEATHER STATEMENT IS OUT. A ZFPMQT UPDATE IS COMING
SHORTLY. NO MAJOR CHANGES TO GOING THEME OF LK EFFECT SNOW SHOWERS
FOR WNW SNOW BELTS...EVENTUALLY AFFECTING W SNOW BELTS OVR THE
KEWEENAW LATE TONIGHT THROUGH FRIDAY. ONLY HEADLINE CHANGE WAS TO
INCLUDE ONTONAGON IN A WIND CHILL ADVY LATE TONIGHT INTO FRIDAY WITH
WSW WINDS 10-20 MPH AND TEMPS FALLING BLO ZERO.
SNOW AMOUNTS TODAY LOOKED GOOD BASED ON EARLIER 12 HR SNOW REPORTS.
SHOULD SEE AN ADDITIONAL 4-7 INCHES THIS AFTN...MAINLY IN THE
SNOWBELTS FROM SHINGLETON TOWARD PINE STUMP JUNCTION AS STRONGEST
SNOW BANDS RESIDE THERE. FOR TONIGHT...TWEAKED SNOW AMOUNTS SLIGHTLY
TO INDICATE HEAVIEST LK EFFECT SNOW FROM CMX SOUTH TO TWIN LAKES.
DOMINANT BAND OF SNOW...ENHANCED BY VIGOROUS LAND BREEZE WITH SUCH
COLD TEMPS...COULD PRODUCE LOCALIZED AMOUNTS UP TO A FOOT FOR THE
TWIN LAKES TO ATLANTIC MINE CORRIDOR. PROBABLY LESS THAN 6 INCHES
WILL OCCUR THROUGH TONIGHT TO THE NORTH OF THE CONVERGENCE BAND OVR
THE REST OF THE KEWEENAW IN A MORE MULTIBAND FASHION.
LASTLY...DIMINISHED SKY COVER OVR INLAND SW THIS AFTN AS WINDS ARE
BECOMING LESS AND LESS OFF THE LAKE. SKIES ARE PRETTY MUCH CLEAR
INTO NW WI. DESPITE THE SUNSHINE...TEMPS ARE GOING TO REMAIN QUITE
COLD. BASED ON TEMP TRENDS...KEPT HIGHS IN THE SW INTERIOR ONLY IN
THE LOWER SINGLE DIGITS. COLD AIR ADVECTION WITH FLOW OFF LK
SUPERIOR SHOULD KEEP REMAINING AREAS WITH STEADY TEMPS IN THE UPR
SINGLE DIGITS KEWEENAW TO THE LOW-MID TEENS ELSEWHERE.
&&
.DISCUSSION... /ISSUED 632 AM EST/
UPPER AIR PATTERN CONSISTS OF A DEEP TROUGH ACROSS THE CENTRAL U.S.
WITH PLENTY OF COLD AIR WITH A 500 MB LOW NE OF LAKE SUPERIOR WHICH
BROUGHT THE BIG WINTER STORM TO THE U.P. YESTERDAY. THE 500 MB
TROUGH WILL STICK AROUND A WHILE AND CONTINUE TO BRING COLD AIR TO
THE AREA FOR A WHILE AND LAKE EFFECT SNOW WHICH THE WIND DIRECTION
WILL PLAY A CRUCIAL ROLE IN WHICH AREAS GET SNOW AND ALSO HOW MUCH.
UPPER AIR PATTERN THIS WEEKEND THEN GOES TO SLIGHTLY MORE ZONAL FROM
WNW TO ESE ACROSS THE AREA WHICH SHOULD MODIFY THE COLD ARCTIC AIR A
BIT AS WELL.
BESIDES LAKE EFFECT...THERE WILL ALSO BE A WEAK SYSTEM FOR SAT AS
BOTH NAM AND GFS BOTH SHOW 850-500 MB Q-VECTOR CONVERGENCE COMING
THROUGH THEN.
EXTREMELY BUSY NIGHT WITH MANY HEADLINES AND PRODUCTS TO WRITE AND
WILL HIT THE HIGH POINTS ONLY.
CHANGED THE WINTER STORM WARNINGS TO LAKE EFFECT SNOW WARNINGS NOW
SINCE THE STORM HAS MOVED AWAY. THESE LAKE EFFECT SNOW WARNINGS ARE
HIGHLY DEPENDENT ON WIND DIRECTION AND WHEN THE WIND CHANGES
DIRECTION...THIS WILL DICTATE WHEN THE SNOW SHOWERS WILL MOVE OUT.
THE WIND WILL GO TO MORE WEST SOUTHWEST TONIGHT EAST OF MUNISING AND
THAT IS WHY THE WARNING WILL NOT GO INTO TONIGHT. ONLY A SMALL PART
OF ALGER AND LUCE COUNTIES WOULD BE AFFECTED BY LAKE EFFECT SNOW
SHOWERS FROM THAT. OPTED TO GO WITH ADVISORIES FOR ONTONAGON AND
SOUTHERN HOUGHTON COUNTIES DUE TO FACT THAT AREAS AFFECTED WILL BE
VERY SMALL. THERE WILL BE WARNING AMOUNTS IN A SMALL AREA NORTH OF
HIGHWAYS OF M-26 AND M-38 WHERE MOST PEOPLE DO NOT LIVE AND DID NOT
WANT TO WARN FOR THE WHOLE COUNTY WHEN ONLY A REALLY SMALL AREA IS
BEING AFFECTED...SO THOUGHT ADVISORY FOR THOSE TWO PLACES IS THE WAY
TO GO. NORTHERN HOUGHTON AND KEWEENAW COUNTIES...A DOMINANT WEST
BAND WILL SET UP SIMILAR TO LAST WEEKEND FOCUSED IN LARGE PART BY
STRONG CONVERGENCE AND FORECASTED UP 16 TO 30 INCHES OF SNOW IN THIS
BAND FROM TODAY THROUGH FRIDAY NIGHT AS THE WIND DIRECTION AND
CONVERGENCE DOES NOT CHANGE MUCH AND THIS BAND WILL BE SOMEWHAT
STATIONARY THROUGH ABOUT 48 HOURS. FINALLY ON SAT...THE WIND BECOMES
SOUTHWEST ENOUGH TO PUSH THIS BAND BACK OFFSHORE.
ISSUED A WIND CHILL ADVISORY FOR MOST OF THE WESTERN HALF OF UPPER
MICHIGAN TONIGHT AND DROPPED LOWS TO NEAR ADJMET GUIDANCE WHICH WAS
THE COLDEST AVAILABLE. IT WILL BE QUITE COLD WITH SOME CLEAR SKIES
AND WIND CHILLS WILL FALL TO 15 TO 30 BELOW ZERO TONIGHT THROUGH FRI
MORNING WHERE IT IS NOT SNOWING OR WHERE IT IS NOT CLOUDY.
FINALLY...LAKE ENHANCED SNOW FROM LAKE MICHIGAN LOOKS LIKELY SAT
AFTERNOON AND SAT NIGHT WITH WINDS FROM THE SOUTH OFF LAKE MICHIGAN
AND IT IS COLD ENOUGH FOR LAKE EFFECT. BUMPED POPS UP TO LIKELY
ACROSS THE EASTERN CWA TO ACCOUNT FOR THIS AND WILL HAVE TO WATCH AS
THERE IS A WEAK SYSTEM GOING THROUGH AS WELL. MIGHT HAVE ADVISORY
TYPE SNOW WITH THIS. WILL PASS THIS CONCERN ON TO DAYSHIFT AND THEY
CAN LOOK CLOSER AT IT.
OVERALL...DID NOT MAKE TOO MANY CHANGES TO TEMPERATURES OR TO GOING
FORECAST. MAIN CHANGES WERE HEADLINE CHANGES AND BUMPED UP SOME SNOW
AMOUNTS IN A FEW PLACES.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
HEAVIEST LK EFFECT/LOWEST FLIGHT CATEGORIES EXPECTED AT KCMX WITH
WRLY LOW-LEVEL WINDS. BAND OF DOMINANT SNOW SHOWERS SHOULD SET UP
OVR KCMX LATE TONIGHT THROUGH FRIDAY...WITH OCCASIONAL CIGS BLO 500
FT AND VSBY LESS THAN 1/2SM. BAND OF LK EFFECT SNOW OFF WRN LK
SUPERIOR MADE IT TO KSAW LATE THIS MORNING BUT RADAR SHOWS THIS IS
NOW LIFTING TO THE NORTH. OVERALL...CONDITIONS AT KSAW REMAIN VFR
THROUGH THE PERIOD WITH W/SW WINDS KEEPING LK EFFECT OUT OF THE
PICTURE.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
GALE WARNINGS WILL CONTINUE OVER PARTS OF THE LAKE UNTIL SUNRISE
THIS MORNING AS THE VERY DEEP LOW PRESSURE SYSTEM OVER SOUTHWEST
QUEBEC DEPARTS TO THE EAST. COLDER AIR MOVING INTO THE REGION HAS
HELPED MIX THE STRONG 925-850 MB WINDS TO THE SURFACE AND WILL ALSO
RESULT IN SOME FREEZING SPRAY. PLEASE SEE THE LATEST MARINE HAZARD
MESSAGE FOR FURTHER DETAILS.
ON TONIGHT THROUGH FRIDAY NIGHT...THERE MAY BE SOME LOCALIZED W
GALES MAINLY OVER THE EASTERN LAKE SUPERIOR ON THE SOUTHERN FLANK OF
LOW PRESSURE STRETCHING FROM WESTERN LAKE SUPERIOR ACROSS THE
KEWEENAW INTO CENTRAL LAKE SUPERIOR. HOWEVER...THESE STRONGER WINDS
WILL NOT BE WIDESPREAD ENOUGH TO JUSTIFY A GALE WATCH. OVERALL
H925-85 WINDS ARE AROUND 30 KTS...WHICH WILL READILY MIX TO THE
SURFACE WITH VERY COLD AIR RESULTING IN STEEP LLVL LAPSE RATES.
FREEZING SPRAY WILL PERSIST. WINDS WILL BE NO MORE THAN 15 TO 25 KTS
THIS WEEKEND...BUT STRONGER NW WINDS TO 30 KTS MAY ARRIVE EARLY NEXT
WEEK AS ANOTHER ARCTIC AIRMASS MOVES INTO THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST FRIDAY FOR MIZ002-084.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST SATURDAY FOR MIZ001-003.
WIND CHILL ADVISORY FROM 10 PM EST /9 PM CST/ THIS EVENING TO 11
AM EST /10 AM CST/ FRIDAY FOR MIZ002-004-005-009>013.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR
MIZ006-007-085.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 PM EST FRIDAY FOR LSZ266-267.
GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LSZ243>245-264-265.
LAKE MICHIGAN...NONE.
&&
$$
UPDATE...JLA
DISCUSSION...07
AVIATION...JLA
MARINE...DLG
