Winter Weather Advisory 7, NWS Gaylord, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
113 PM EST THU FEB 23 2012

.UPDATE...
ISSUED AT 113 PM EST THU FEB 23 2012

SATL SHOWS CONVECTIVE TEMP WAS REACHED SHORTLY AFTER 15Z WITH SCT-
BKN CU/SC OUTSIDE OF MORE SOLID OVC DECK. WITH AN EQUILIBRIUM LVL
NEAR 6K FT...POCKETS OF FLURRIES HAVE DEVELOPED. SO EXTENDED
MENTION OF FLURRIES FURTHER INTO THE AFTN HRS. DESPITE HEAVIER
CLOUD COVER...TEMPS ARE DOING WELL VS FCST.

FCST DWPTS ARE RUNNING A LITTLE TOO HIGH VS REALITY WHERE MOST SUN
HAS OCCURRED OVER MBL COUNTY. HAVE MERGED CURRENT DWPTS WITH
LATEST GFS MAV TO ACCOUNT FOR LOWER RH. OTHERWISE...JUST MINOR
BRUSH-UP TO CLOUDS.

UPDATE ISSUED AT 1008 AM EST THU FEB 23 2012

FCST AREA IS IN A COL WITH VERY LITTLE TO CHANGE PRESENT
SITUATION. SO FCST IS ESSENTIALLY PERSISTENCE. MODEST LAKE
INSTABILITY CONTINUES. SO RECONFIGURED LOW POPS FOR FLURRIES AND
EXTENDED THEM FURTHER OUT IN TIME. CONVECTIVE TEMP WILL BE REACHED
SHORTLY IN SUNNY AREAS. SO EXPECT SOME SC TO DEVELOP.

BIGGEST FCST ADJUSTMENT WAS TO CLOUD COVER...TO BETTER DEPICT
CLR/OVC EXTREMES. OTHERWISE...NO SUBSTANTIAL ADJUSTMENTS TO THE
FCST THO CAN SEE NEED FOR POSSIBLY LOWERING MAX TEMPS WHERE
THICKEST OVC REMAINS...IF WE CAN GET A HANDLE ON IT. SOME EROSION
IS OCCURRING AT THE EDGES. WOULD LIKE TO SEE CURRENT CLOUDS
MAINTAINED BEFORE ADJUSTING TEMPS.

FOR TNGT-FRI: WE WILL BE EVALUATING THE NEED FOR WINTER WX
ADVISORY FOR GLADIN/ARENAC COUNTIES FOR 2-4" POTENTIAL. ALSO CAN
ENVISION POTENTIAL FOR LOW-END GALE WARNINGS ON PARTS OF LAKE
HURON NSH WATERS DEPENDENT ON EVENTUAL STRENGTH OF SFC LOW FRI. A
990 MB LOW VICINITY BUF TOUGH TO IGNORE. WILL UPDATE HWO TO
INDICATE THIS POTENTIAL.

UPDATE ISSUED AT 641 AM EST THU FEB 23 2012

NO SIGNIFICANT UPDATES. ADJUSTED TEMPERATURES UP A BIT THROUGH 12Z
AS CLOUDS BECAME A BIT MORE APPARENT...SLOWING THE TEMP FALL...SO
ADJUSTED THERE TOO. QUIET DAY ON TAP.

&&

.SYNOPSIS...
ISSUED AT 1008 AM EST THU FEB 23 2012

THERE WILL BE A SHORT LIVED LULL IN THE WEATHER TODAY WITH
CONTINUED MILD TEMPERATURES...ESPECIALLY WHERE THE MOST SUNSHINE
OCCURS. MEANWHILE...SRN PLAINS LOW PRESSURE WILL STRENGTHEN...AND
MOVE ACROSS THE NORTHERN OHIO VALLEY LATE TONIGHT. THIS SYSTEM
WILL BRING ANOTHER ROUND OF LIGHT SNOW LATER TONIGHT INTO FRIDAY
TO MUCH OF THE REGION. SEASONAL TEMPERATURES AND LIGHT LAKE EFFECT
SNOW SHOWERS ARE THEN POSSIBLE FRIDAY NIGHT INTO THE FIRST HALF OF
THE WEEKEND.

&&

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 347 AM EST THU FEB 23 2012

LONGWAVE TROUGH OVER HEAD WITH SHORTWAVE ENERGY ALL AROUND
US...BUT NOTHING IMPINGING ON NRN MICHIGAN WITH AN OVERALL LACK OF
UPWARD VERTICAL MOTION. COUPLE THAT WITH A TRANSITION TO A MORE
STABLE AIR MASS WITH A LACK OF AN INVERSION STILL...AND SKIES HAVE
BEEN BEHAVING LIKE SUMMERTIME...DIMINISHING THROUGH THE NIGHT.
MANY AREAS HAVE CLEARED OUT AND TEMPERATURES IN SOME SPOTS HAVE
FALLEN INTO THE TEENS. LOW LEVEL COLD AIR HAD NOT BEEN COLD
ENOUGH TO SPAWN LAKE EFFECT CLOUDS EITHER. HOWEVER...A COLD FRONT
LOCATED JUST NORTH OF CHIPPEWA COUNTY...OUT OVER LAKE
SUPERIOR...HAS NOT ONLY KEPT SOME SCATTERED LIGHT SNOW SHOWER
ACTIVITY AND MORE WIDESPREAD CLOUDS THERE. THE WESTERLY WIND HAS
ALLOWED FOR THE CONTINUATION OF WEAK COLD ADVECTION INTO NRN
MICHIGAN. 925MB AIR TEMPS APPROACHING -5C/-6C...AND OVER THE LAST
COUPLE OF HOURS...AND WE HAVE HAD SOME SUB 3KFT CLOUDS DEVELOP
WITH THE HELP OF SOME MID LEVEL MOISTURE COMING IN OFF LAKE
MICHIGAN. TEMPERATURES IN THE CLOUDIER AREAS WERE IN THE LOWER
30S. SO TEMPS WERE ALL OVER THE PLACE.

THROUGH TODAY...THE COLD FRONT WILL REMAIN NORTH OF CHIPPEWA
COUNTY...WHILE IT'S PARENT SFC LOW PULLS OFF INTO EASTERN CANADA.
THE PRESSURE GRADIENT WEAKENS THROUGH THE DAY...SO MOISTURE FLUXES
OFF THE LAKES WILL WANE. THE AIR MASS DRIES FROM ALOFT AND
SUBSIDENCE RESULTS IN A DEVELOPING INVERSION WHILE THE BL IS
STILL ON THE MOIST SIDE OF THINGS. THE COMBINATION OF EARLY
MORNING LAKE EFFECT CLOUDS...AND DAYTIME HEATING WILL LIFT THE BL
MOISTURE UP UNDERNEATH THE INVERSION. FEEL THAT IF THE DAY STARTS
OUT SUNNY IN SPOTS...THESE WILL FILL IN THROUGH THE MORNING AND
RESULT IN A MOSTLY CLOUDY DAY. COUPLE THAT WITH A SHORTWAVE
LIFTING THROUGH THE MID MISSISSIPPI VALLEY AND AN ASSOCIATED SFC
LOW PRESSURE WORKING INTO INDIANA...HIGH LEVEL CLOUDS WILL ALSO BE
SPREADING IN LATE IN THE AFTERNOON. OUTSIDE OF A CHANCE FOR LIGHT
SNOW SHOWERS IN CHIPPEWA COUNTY EARLY THIS MORNING...A WEAK WIND
AND NO FORCING WILL RESULT IN A DAY BETTER DESCRIBED WITH THE
WORDS "NO SNOW". HIGH TEMPERATURES WILL BE IN THE MID AND UPPER
30S AGAIN....SIMILAR TO YESTERDAY.

TONIGHT AND FRIDAY...THE TRACK OF THIS SFC LOW PRESSURE IS MORE
AGREED UPON NOW....THROUGH OH/PA FRIDAY MORNING...ALTHOUGH THERE
STILL REMAINS SOME LEVEL OF UNCERTAINTY. THERE ARE OTHER THINGS
TO WORK OUT WITH THIS PARTICULAR STORM. A SECOND ISSUE IS THE
STRENGTH AND ORIENTATION OF THE PARENT SHORTWAVE...AS THE GFS IS
MORE AMPLIFIED THAN OTHER SOLUTIONS...THUS SPREADING GREATER
ACCUMULATIONS FURTHER NORTH INTO OUR NECK OF THE WOODS. AS FAR AS
A WEATHER DESCRIPTION THROUGH FRIDAY...BELIEVE THAT CLOUDS STUCK
UNDER THE INVERSION TODAY...WILL REMAIN LOCKED IN LONG ENOUGH INTO
THE EVENING FOR A GENERALLY CLOUDY SKY. THEN...HIGH LEVEL MOISTURE
JUST THICKENS THROUGH THE NIGHT. THERE WILL BE A LOT OF DRY AIR
CENTERED AROUND 700MB THAT WILL NEED TO BE OVERCOME...AND THE
ONSET OF SNOW WILL BE SLOWED BY THIS NEED TO MOISTEN DEEPER
THROUGHOUT THE COLUMN. THAT SAID...FEEL THAT LIGHT SNOWS WILL
BREAK OUT BY DAYBREAK ACROSS MUCH OF OUR SE CWA. THE BRUNT OF THE
SNOWS WILL OCCUR FRIDAY MORNING THROUGH EARLY AFTERNOON...BEFORE
EVERYTHING DEPARTS EAST...AND THE SNOW GRADUALLY WINDS DOWN. NOT
SEEING SIGNIFICANT SNOWFALL...BUT SEVERAL INCHES OF SNOW AND AN
ADVISORY ARE POSSIBLE ACROSS GLADWIN/ARENAC COUNTIES AT THIS
POINT. THE TRACK OF THE 500MB LOW OVER NRN LOWER OUGHT TO BRING AT
LEAST SOME SNOW TO MOST. EASTERN UPPER LOOKS TO REMAIN OUT OF THE
SYNOPTIC SNOWS...BUT COLD ADVECTION UNDER BACKING WINDS FROM NE TO
NW...COULD BRING IN SOME LIGHT LAKE EFFECT TO WESTERN CHIP/MACK
(H8 TEMPS FALLING TO -12C IN SUFFICIENT MOISTURE. FCST SOUNDINGS
COULDN'T BE MORE DIFFERENT BETWEEN NAM/GFS THOUGH (NAM MORE
AGGRESSIVE WITH LES). WILL JUST INCREASE CHANCES OF SEEING SNOW
THERE TO 40 PERCENT. HIGHS IN THE LOW TO MID 30S.

.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 347 AM EST THU FEB 23 2012

FRIDAY NIGHT INTO SATURDAY NIGHT...A TROUGH EVIDENT ON WATER VAPOR
LOOP OVER MONTANA LOOKS LIKE IT WILL MOVE ACROSS THE REGION FRIDAY
NIGHT INTO SATURDAY. MODELS CONTINUE TO SHOW SOME SEMBLANCE OF
INTERACTION BETWEEN THIS SYSTEM AND THE ONE DEPARTING TO THE
NORTHEAST (WHICH IS ALWAYS A RISKY PROPOSITION). IN ADDITION...IT
BECOMES MARGINALLY COLD ENOUGH TO INVOLVE THE LAKES SO WILL CONTINUE
WITH LIKELY POPS IN NNW FAVORED AREAS WITH CHANCE TO SLIGHT CHANCE
POPS ELSEWHERE. NOT QUITE AS MILD WITH LOWS IN THE MIDDLE TEENS TO
LOWER 20S AND HIGHS RANGING FROM THE MIDDLE 20S NORTH TO THE LOWER
30S SOUTH.

SUNDAY THROUGH NEXT WEDNESDAY...THE PATTERN STILL LOOKS AT LEAST
SOMEWHAT ACTIVE. EXTENDED MODELS CONTINUE TO BRING A WOUND UP (BUT
WEAKENING) AREA OF LOW PRESSURE OUT OF THE PLAINS INTO THE WESTERN
GREAT LAKES LATER IN THE WEEKEND INTO EARLY NEXT WEEK (ALTHOUGH AM
LESS IMPRESSED WITH THE STRUCTURE/TRACK TODAY). BIG QUESTION MARKS
REMAIN OVER THE TRACK OF THIS SYSTEM (WHICH IS TRENDING A BIT
FARTHER NORTH) AS WELL AS POSSIBLE PRECIPITATION TYPE ISSUES COMING
INTO PLAY AS THE LOW LIKELY TRACKS BY TO OUR NORTHWEST (DRAWING UP
WARM AIR FROM THE SOUTH). THERE IS ALSO LIKELY TO BE A DECENT DRY
SLOT WHICH COULD SHUT OFF PRECIPITATION FOR A TIME. DUE TO CONTINUED
UNCERTAINTY...WILL HOLD COURSE WITH HIGH CHANCE OR LOW LIKELY POPS
FOR SUNDAY NIGHT INTO MONDAY (FOR SNOW SUNDAY NIGHT AND RAIN OR SNOW
MONDAY). IT LOOKS LIKE A PIECE OF MODIFIED ARCTIC AIR WILL THEN MOVE
IN BEHIND THE SYSTEM FOR MONDAY NIGHT INTO TUESDAY BRINGING COLDER
TEMPERATURES AND A DECENT SHOT OF LAKE EFFECT SNOW SHOWERS. YET
ANOTHER SYSTEM IS POSSIBLE FOR WEDNESDAY...BUT IT IS WAY TOO FAR OUT
TO PIN DOWN ANY DETAILS...JUST CHANCE POPS FOR NOW.

SULLIVAN

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 113 PM EST THU FEB 23 2012

REST OF THE AFTN: LOW-END VFR 3500-4000 FT CIGS WILL PREVAIL ALL
TERMINALS EXCEPT MBL WHICH WILL HAVE 20K FT CIGS. SOME TEMPO MVFR
CIGS DOWN TO 2000 FT ARE POSSIBLE TVC PLN APN ALONG WITH SOME VFR
FLURRIES. WINDS WILL BE VARIABLE AOB 5 KTS.

CONFIDENCE HIGH ALL ELEMENTS.

TNGT: CONFIDENCE IN LOW-END VFR CIGS IS AVERAGE AND PARTIALLY
BASED ON SOME PERSISTENCE. SATL SHOWS A DIURNAL COMPONENT AND
EXPECT THIS TO DISSIPATE EARLY. THIS COULD RESULT IN CLOUDS
BECOMING SCT. MULTI-LAYERED HIGH CLOUDS INVADE AND GRADUALLY
DESCEND THRU THE NGT. MVFR CIGS WILL DEVELOP AFTER 08Z AND IFR -SN
WILL FOLLOW AT MBL TVC APN. LIGHT AND VARIABLE WINDS ORGANIZE FROM
THE NE AFTER 03Z BUT REMAIN AOB 10 KTS.

OVERALL CONFIDENCE AVERAGE ON TIMING OF CHANGE IN FLGT CATEGORIES.

FRI THRU 18Z: IFR CIGS/VSBYS IN -SN WITH HIGHEST CONFIDENCE MBL
TVC APN. UNSURE IF NRN FRINGE OF -SN MAKES IT TO PLN. THERE IS A
LOW PROB THAT PLN REMAINS VFR. N WINDS INCREASE 10-20 KTS AND
GUSTY WITH GRADUAL VEERING TO NE.

CONFIDENCE AVERAGE ALL ELEMENTS.

&&

.MARINE...
ISSUED AT 347 AM EST THU FEB 23 2012

A GENERALLY LIGHT AND VARIABLE WIND OVER THE NEARSHORES THROUGH
TODAY...BEFORE LOW PRESSURE LIFTS THROUGH THE MID MISSISSIPPI
VALLEY THIS EVENING...AND THROUGH AREAS NORTH OF THE OHIO RIVER
VALLEY THROUGH FRIDAY. THE LIGHT WINDS WILL INCREASE AND SWITCH TO
OUT OF THE NORTH AS THE LOW PRESSURE NEARS. CAN SEE SMALL CRAFT
ADVISORIES BEING NEEDED THROUGH THE MANITOU ISLANDS AND DOWN A
LARGE STRETCH OF THE LAKE HURON SHORELINES LATE TONIGHT INTO
FRIDAY MORNING. WINDS SHOULD THEN STAY BELOW SCA LEVELS UNTIL
LATE SUNDAY...WHEN THE NEXT LOW PRESSURE NEARS.

&&

.CLIMATE...
ISSUED AT 1008 AM EST THU FEB 23 2012

F6 FORMS ARE SHOWING THIS HAS BEEN A VERY MILD MONTH AT LONG TERM
CLIMATE SITES. BELOW IS A LISTING OF AVG TEMP DEPARTURES AND
CURRENT RANK AS OF TODAY. SOME MINOR FLUCTUATIONS MAY OCCUR BEFORE
FINALIZATION AT THE END OF THE MONTH...BUT NO PATTERN CHANGE
SUGGESTS WE WON'T BE FAR FROM THESE VALUES.

SSM +9.9F AND 2ND WARMEST
APN +8.5F AND 3RD WARMEST
HTL +7.5F AND 3RD WARMEST
TVC +7.5F AND 2ND WARMEST

THIS WON'T GO DOWN AS THE WARMEST FEB ON RECORD. THERE'S NO WAY
WE'LL BEAT THOSE NUMBERS FROM 1998. BUT THIS ONE WILL STILL BE VERY
RESPECTABLE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

UPDATE...HALBLAUB
SYNOPSIS...HALBLAUB
SHORT TERM...SD
LONG TERM....AS
AVIATION...HALBLAUB
MARINE...SD
CLIMATE...HALBLAUB

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GAYLORD MI
1018 AM EST THU FEB 23 2012

LHZ345>349-LMZ323-341-342-344>346-LSZ321-322-MIZ008-015>036-041-042-
241215-
STRAITS OF MACKINAC-ST IGNACE TO FALSE DETOUR CHANNEL-
MACKINAC BRDG TO PRESQUE ISLE LT-PRESQUE ISLE LT TO STURGEON PT-
STURGEON PT TO ALABASTER-GRAND TRAVERSE BAY-
SEUL CHOIX PT TO MACKINAC BRDG-NORWOOD TO MACKINAC BRDG-
SLEEPING BEAR PT TO GRAND TRAVERSE LT-PT BETSIE TO SLEEPING BEAR PT-
MANISTEE TO PT BETSIE-WHITEFISH BAY-ST. MARYS RIVER-CHIPPEWA-
MACKINAC-EMMET-CHEBOYGAN-PRESQUE ISLE-CHARLEVOIX-LEELANAU-ANTRIM-
OTSEGO-MONTMORENCY-ALPENA-BENZIE-GRAND TRAVERSE-KALKASKA-CRAWFORD-
OSCODA-ALCONA-MANISTEE-WEXFORD-MISSAUKEE-ROSCOMMON-OGEMAW-IOSCO-
GLADWIN-ARENAC-
1018 AM EST THU FEB 23 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHERN LOWER MICHIGAN...
EASTERN UPPER MICHIGAN...AND ADJACENT NEARSHORE WATERS OF LAKE
MICHIGAN...LAKE HURON AND LAKE SUPERIOR.

.DAY ONE...TODAY AND TONIGHT

A LOW PRESSURE SYSTEM WILL LIFT INTO THE EASTERN GREAT LAKES LATE
TONIGHT AND FRIDAY WITH SIGNIFICANT SNOWFALL EXPECTED FOR SOUTHERN
LOWER MICHIGAN. THERE REMAINS SOME QUESTION TO THE EXACT TRACK OF
THIS STORM...WHICH HAS IMPLICATIONS OF THE EXTENT OF THE SNOWFALL
FOR NORTHERN MICHIGAN. TRENDS ARE SUGGESTING THAT ACCUMULATING SNOW
WILL REACH TO THOSE COUNTIES ALONG THE M-55 CORRIDOR...MAINLY CLOSE
TO SAGINAW BAY. PLEASE SEE LATEST FORECASTS FOR MORE DETAILED
FORECAST SNOW AMOUNTS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

FRIDAY...SIGNIFICANT ACCUMULATIONS ARE POSSIBLE NEAR SAGINAW BAY.
THERE IS ALSO A CHANCE FOR LOW-END NORTHERLY GALE FORCE WINDS ON THE
NEARSHORE WATERS OF LAKE HURON...MAINLY SOUTH OF THUNDER BAY.

ANOTHER LOW PRESSURE SYSTEM IS EXPECTED TO MOVE THROUGH THE UPPER
GREAT LAKES SUNDAY NIGHT INTO MONDAY. THERE CONTINUES TO BE PLENTY
OF UNCERTAINTY WITH ITS TRACK AND STRENGTH. HOWEVER...THE
POTENTIAL REMAINS FOR ACCUMULATING SNOW. THE SNOW MAY MIX
WITH...OR CHANGE OVER TO ALL RAIN...IN PORTIONS OF NORTHERN
MICHIGAN MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ALWAYS ENCOURAGED TO REPORT SNOWFALL AMOUNTS TO THE
NATIONAL WEATHER SERVICE.

REPORTS MAY BE MADE ONE OF TWO WAYS:

BY PHONE: 1-800-647-8676 (REPORTS ONLY PLEASE...NO FORECASTS)

BY FACEBOOK: FACEBOOK.COM/US.NATIONALWEATHERSERVICE.GAYLORD.GOV

SMD/HALBLAUB