Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 030540
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1240 AM EST WED FEB 3 2016

.UPDATE...
ISSUED AT 1231 AM EST WED FEB 3 2016

WARM ADVECTION PRECIPITATION CONTINUES TO STREAK NORTH
NORTHEASTWARD AND WILL CLEAR MOST AREAS SHORTLY LEAVING BEHIND
SOME DRIZZLE OR FREEZING DRIZZLE. TEMPERATURES CONTINUE TO SLOWLY
WARM SO FREEZING DRIZZLE SHOULD BECOME LESS OF AN ISSUE OVER THE
NEXT COUPLE OF HOURS...PLUS IT SHOULD BE FAIRLY LIGHT.
THEREFORE...WILL GO AHEAD AND CANCEL ALL ADVISORIES ACROSS
NORTHERN LOWER AS WELL AS THE WARNINGS ACROSS THE TIP OF THE MITT
(WHICH WERE DUE TO EXPIRE AT 06Z ANYWAYS). MEANWHILE...ACROSS
EASTERN UPPER...SNOWFALL AMOUNTS WILL FALL WELL SHORT OF WARNING
CRITERIA WITH ONLY ANOTHER INCH OR TWO EXPECTED...SO WILL CANCEL
THE WARNINGS UP THERE AS WELL.

UPDATE ISSUED AT 1035 PM EST TUE FEB 2 2016

STRONG SURFACE LOW CENTER IS NOW OVER IOWA...NRN MISSOURI AND
ILLINOIS LATE THIS EVENING. WIDESPREAD SNOW AMOUNTS OF ROUGHLY 3 TO
5 INCHES HAVE FALLEN OVER MUCH OF NRN LWR MICHIGAN...WITH QUITE A
BIT OF RAIN/FREEZING RAIN/SLEET MIXING IN ACROSS OUR SRN AND SW
COUNTIES THIS EVENING TOWARD THE BACK END OF THE SNOW SHIELD AS
WARMER AIR ALOFT LIFTS INTO THE REGION. ACCUMULATING SNOW STARTED
A BIT LATER ACROSS ERN UPR MICHIGAN...AND IS STILL IN THE PROCESS
OF INCREASING IN INTENSITY. BACK EDGE OF WIDESPREAD PRECIP IS
APPROACHING OUR SW CWA ALIGNED WITH THE NE EDGE OF THE DRY SLOT.
THIS SHOULD BRING A TEMPORARY END TO MEASURABLE PRECIP TO MUCH OF
NRN LWR MICHIGAN FOR THE OVERNIGHT HOURS...LEAVING MAINLY DRIZZLE
AND/OR FREEZING DRIZZLE THROUGH 12Z AT LEAST. DRIZZLE/FREEZING
DRIZZLE ON TOP OF SEVERAL INCHES OF NEW SNOW SHOULD HAVE LITTLE
IMPACT ON ALREADY RATHER HAZARDOUS ROAD CONDITIONS. WILL THEREFORE
NOT EXTEND ANY HEADLINES PAST 06Z ACROSS NRN LWR MICHIGAN AS MOST
MEASURABLE PRECIP SHOULD HAVE EXITED THIS AREA BY THAT TIME. WILL
MAINTAIN HEADLINES FOR ERN UPR MICHIGAN WHERE SNOW SHOULD CONTINUE
THRU THE OVERNIGHT HOURS WHERE WE SHOULD SEE ANOTHER 2 TO 4 INCHES
OF SNOW ACCUMULATION.

&&

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 253 PM EST TUE FEB 2 2016

IMPACT WEATHER: ACCUMULATING SNOW AND BLOWING SNOW. MONITORING THE
POTENTIAL FOR FREEZING RAIN AND FREEZING DRIZZLE. PROBABLY THE WHOLE
GAMUT OF PRECIPITATION TYPES TONIGHT. SNOW INITIALLY THOUGH.

SYNOPTIC PATTERN AND OBSERVATIONS:

WELL ADVERTISED STRONG SFC LOW PRESSURE WILL LIFT NE AND INTO NRN
LOWER BY DAYBREAK. TIGHT EASTERLY PRESSURE GRADIENT AND SWATH OF
DEEPER MOISTURE NORTH OF AN ADVANCING WARM FRONT AND STRONG LOW TO
MID LEVEL WAA AND CONVERGENCE. FORCING ALSO SUPPLIED BY DOUBLE UPPER
JET STRUCTURE DIVERGENCE. BOTH FORCING MECHANISMS WORK INTO EASTERN
UPPER THIS EVENING AND COMBINES WITH DPVA FORCING FROM THE PARENT
SHORTWAVE...AND ULTIMATE STRONGEST FORCING. WHILE SOME DEEPER
MOISTURE LINGERS ON THE N/NW FLANK OF THE SFC LOW...THE SYSTEM DRY
SLOT POUNDS DIRECTLY THROUGH NRN MICHIGAN ON THE LEADING EDGE OF
STEEPER LAPSE RATES ALOFT...CRUSHING PRECIPITATION INTENSITY AS A
RESULT OF THE LOSS OF NOT ONLY MOISTURE...BUT FORCING AS WELL.
THERMODYNAMICALLY...A SATURATED WARM NOSE AS WARM ABOVE 0C SWEEPS
INTO PRETTY MUCH ALL EXCEPT THE FAR WESTERN REACHES OF CHIP/MACK
COUNTIES OF EASTERN UPPER...WITH A MAX OF +6C THROUGH GLADWIN AND
ARENAC COUNTIES. WHILE THIS IS OCCURRING THERE IS A PRETTY DEEP LOW
LEVEL COLD AIR MASS WITH SFC BASED TEMPS CLIMBING JUST ABOVE
FREEZING. THIS SCENARIO WILL PROVIDE US WITH QUITE THE GAMUT OF
PRECIPITATION TYPES. IN GENERAL...HERE`S HOW IT PLAYS OUT...A PERIOD
OF SNOW WILL MIX WITH SLEET...POSSIBLY A BRIEF PERIOD OF FREEZING
RAIN IN THE HIGHER TERRAIN OF INTERIOR NRN LOWER...AND LIKELY A FEW
RUMBLES OF THUNDER...BEFORE DIMINISHING TO DRIZZLE...AND EASTERN
UPPER SEEING SOME FREEZING DRIZZLE AS WELL. THE SYSTEM DEFORMATION
ZONE AND DEEPER MOISTURE LOOKS TO HANG OUT JUST WEST OF US.

SYNOPTIC PATTERN AND WEATHER EVOLUTION:

SNOW WAS ALREADY IMPACTING AREAS JUST SOUTH AND WEST OF GRAND
TRAVERSE BAY....WHILE SOME LOWER LEVEL DRY AIR WAS TRYING TO
SATURATE. THIS PROCESS WON`T TAKE TOO LONG...AND SNOWS WILL BREAK
OUT FROM SOUTH TO NORTH THROUGH THE REMAINDER OF THE AFTERNOON AND
EARLY EVENING. EVERYONE GETS A PERIOD OF SNOW AND AS EASTERLY WINDS
START TO CRANK UP TO AROUND 30 MPH...RESULTING IN BLOWING SNOW...AS
THE WARM NOSE DOES NOT MAKE IT UP HERE UNTIL AFTER PRECIPITATION
STARTS. THOUGHTS HAVE CHANGED SINCE THE MORNING UPDATE. WATCHING SFC
OBS THROUGH THE DAY SHOW DEW POINTS DOWN INTO THE MIDDLE 20S AS OF
RIGHT NOW FOR MUCH OF THE CWA. SOME WET BULB/EVAPORATIVE COOLING
WILL JUST KEEP SFC BASED TEMPERATURES LOW ENOUGH FOR RAIN TO BE HELD
OFF FOR AWHILE...BUT SLEET WILL SLOWLY JOIN THE SNOW AS THE WARM
NOSE LIFTS INTO THE REGION. THE LOW LEVEL COOLER AIR WHICH IS BELOW
FREEZING IS QUITE DEEP FOR AWHILE...AND ALTHOUGH THE TYPICAL -6C IS
USUALLY NEEDED TO RE-FREEZE THE DROPS COMPLETELY...THE DEPTH OF THE
COLD AIR SHOULD BE ABLE TO DO THAT. EVENTUALLY THOUGH...THIS LOW
LEVEL COLD AIR WILL SHALLOW OUT WITH TIME WHILE TEMPS ALOFT CONTINUE
TO WARM THROUGH LATE EVENING...AND THERE IS A SLOW CLIMB ABOVE
FREEZING AT THE SFC. THIS WILL RESULT IN A PERIOD OF RAIN MIXING
IN...OR CHANGING COMPLETELY TO RAIN ACROSS LOCATIONS NEAR SAGINAW
BAY. UNLESS OF COURSE THE SYSTEM DRY SLOT ARRIVES BEFOREHAND AND
TURNS EVERYTHING TO JUST PERIODS OF DRIZZLE AND SOME LIKELY FOG
DEVELOPMENT. THIS DRIZZLE AND FOG WILL REACH EASTERN UPPER
OVERNIGHT...AND ALL OF THE REGION SHOULD WAKE UP TO DREARY AND MILD
WEATHER.

AS FAR AS HEADLINES...THERE IS A LOT GOING ON...AND CHANGING PRECIP
TYPES ALWAYS POSES DIFFICULTY. HOWEVER...THE STRONG WARM ADVECTION
AND FORCING IS LIKELY GOING TO LEAD TO 1-2" PER HOUR SNOWFALL RATES
WHEN THE SNOW SWINGS THROUGH. THE SNOW WILL AFFECT THE EVENING
COMMUTE AROUND GRAND TRAVERSE BAY...AND GREATER AMOUNTS OF SNOW ARE
EXPECTED THE FURTHER NORTH YOU GO. ANY FREEZING RAIN/FREEZING DRIZZLE
WILL LIKELY NOT POSE ANY THREAT WITH SNOW OCCURRING ON THE FRONT END
OF THE WINTER EVENT...BUT THERE IS LIKELY ENOUGH IMPACT TO KEEP
HEADLINES WHERE THEY ARE. AM JUST NOT GONNA THROW ANY OTHER COUNTIES
IN AT THIS POINT...NOR DOWNGRADE/UPGRADE ANYONE. THE CURRENT SET OF
ADVISORIES..IF PLACED AGAIN FROM THE START...ARE IN REASONABLY AND
METEOROLOGICALLY SOUND POSITIONS BASED ON IMPACT OF SNOWFALL...WIND
AND SNOWFALL RATE EXPECTATIONS.

&&

.SHORT TERM...(WEDNESDAY THROUGH FRIDAY)
ISSUED AT 253 PM EST TUE FEB 2 2016

WEDNESDAY THROUGH FRIDAY...THE PLAINS STORM SYSTEM WHICH LIFTED INTO
THE STATE ON TUESDAY...WILL EXIT NORTHEAST INTO QUEBEC EARLY
THURSDAY WHILE AREA OF HIGH PRESSURE BUILDS INTO THE GREAT LAKES AND
UPPER MIDWEST. AT UPPER LVLS...A 500MB RIDGE OVER THE ERN LAKES
WEDNESDAY MORNING WILL PUSH EAST OF THE REGION...WHILE A BROAD 500MB
TROUGH DIGS DEEPER INTO THE PLAINS AND ACROSS THE GREAT LAKES. 850MB
TEMPS IN THIS PATTERN COOL FROM AROUND +3C OVER LOWER MICHIGAN
WEDNESDAY MORNING TO BETWEEN -12C AND -14C THURSDAY AND FRIDAY.
OVERALL PATTERN THROUGH THE PERIOD...WILL BE A TRANSITION FROM
SYNOPTIC SCALE FORCING AND PRECIPITATION WED...TO LAKE INDUCED
SNOWFALL THURSDAY AND FRIDAY.

WEDNESDAY...WIDESPREAD PCPN CONTINUES ACROSS NRN MI THROUGH THE
AFTERNOON...AS CYCLONIC LOW LVL FLOW LINGERS OVER NRN MI ON THE
BACKSIDE OF THE EXITING STORM SYSTEM. 850/500MB QVECTORS SHOWING THE
STRONGEST CONVERGENCE WITH THIS FORCING DIMINISHING AND PUSHING EAST
OF LAKE HURON BETWEEN 21Z WED AND 00Z THURSDAY. SEVERAL ITEMS
COMPLICATE PCPN CHANCES AND TYPE OVER NRN MI WEDNESDAY...THE MAIN
TWO BEING MID LVL DRY AIR AND LOW LVL TEMP PROFILES. MODEL SOUNDINGS
SHOW 850/500MB RH UNDER 50 PCT INTO WEDNESDAY AFTERNOON (DRY AIR
ASSOCIATED WITH RIDGE OF HIGH PRESSURE BUILDING INTO THE REGION)
WITH SATURATED LOW LVL MOISTURE EXISTING IN TEMPS WARMER THAN
-10C. MODEL SOUNDINGS SHOW A VERTICAL TEMP PROFILE ABOVE FREEZING
FROM THE SFC THROUGH 4K FT OVER MUCH OF NRN LOWER MI THROUGH WED
MORNING...WITH TEMPS BELOW THE 0C ISOTHERM OVER ERN UPPER. HOWEVER
MODEL SOUNDINGS SHOW MID LVL MSTR INCREASING AGAIN OVER THE NRN
LAKES BETWEEN 18Z WED AND 00Z THURS IN ADVANCE OF 500MB TROUGH
PUSHING INTO THE GREAT LAKES...AS VERTICAL TEMP PROFILES BY 00Z FALL
TO COLDER THAN THE 0C ISOTHERM (EXPECT AROUND SAGINAW BAY REGION
WHERE WARMER AIR HOLDS ON A TAD LONGER). OVERALL WILL CONTINUE TO
MENTION MIXED PCPN OVER NRN LWR WED MORNING (MAINLY DRIZZLE)...WITH
ALL SNOW OVER ERN UPPER. WILL TREND TO ALL SNOW ACROSS NRN LWR
WEDNESDAY AFTN...AS MID LVL MSTR INCREASES AND VERTICAL TEMP
PROFILES FALL COLDER THAN 0C.

LAKE EFFECTS BECOME THE MAIN FOCUS WEDNESDAY NIGHT THROUGH FRIDAY AS
850MB TEMPS FALL TO -12C TO -16C IN DEEP UPPER TROUGH. SFC-850MB
WINDS TREND FROM NORTH-NORTHWEST WEDNESDAY NIGHT IN LINGERING
CYCLONIC FLOW TO WEST THURSDAY AFTERNOON THROUGH FRIDAY. MODEL
SOUNDINGS SHOWING INVERSION HEIGHTS GENERALLY BETWEEN 5K AND 6K FEET
THROUGH THE PERIOD. THURSDAY NIGHT WILL BE A SIGNIFICANT PERIOD OF
LAKE SNOW FOR NRN LWR...WITH PERSISTENT WEST FLOW AND INVERSION
HEIGHTS INCREASING TO 7500 FT.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 253 PM EST TUE FEB 2 2016

THE PATTERN REMAINS VERY ACTIVE IN THE EXTENDED PERIOD AS A STEEP
500MB RIDGE BUILDS ALONG THE PACIFIC COAST AND WESTERN
ROCKIES...LEAVING THE REST OF US IN BROAD TROUGHING. A RELATIVELY
WEAK SHORT WAVE SPINS THROUGH THE LAKES ON SATURDAY...GENERATING
SOME SNOW SHOWERS ACROSS NORTHERN MICHIGAN. THEN...NO SOONER THE
MOISTURE DEPARTS FROM THAT FEATURE...MOISTURE INVADES FROM THE WEST
IN ADVANCE OF A SLOW MOVING STORM SYSTEM DROPPING DOWN FROM SOUTH
CENTRAL CANADA. MODELS SHOWING AN EAST COAST RIDGE SLOWING THE
PROGRESS OF THIS STORM...AS THE LOW SETS UP CAMP OVER THE LAKES
THROUGH TUESDAY. BEYOND THE FORECAST PERIOD...AS THIS LOW PULLS
OUT...A COOLER REGIME PERSISTS WITH THE SHOT AT SOME ADDITION LAKE
SNOWS MID WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1231 AM EST WED FEB 3 2016

WARM ADVECTION PRECIPITATION IN ADVANCE OF LOW PRESSURE TO THE
SOUTH HAS PRETTY MUCH ENDED AS DRIZZLE ACROSS THE TAF SITES.
EXPECT THE DRIZZLE TO CONTINUE OVERNIGHT WITH LOWERING VSBYS AND
POSSIBLE FOG FORMATION. WRAP AROUND SNOW SHOWERS WILL LIKELY
IMPACT ALL TAF SITES...EXCEPT FOR APN THIS AFTERNOON. LAKE EFFECT
SNOW SHOWERS WILL THEN DEVELOP TONIGHT...IMPACTING MAINLY TVC.
EASTERLY WINDS WILL BE GUSTY EARLY THIS MORNING BEFORE
DIMINISHING. WINDS WILL THEN BECOME NORTHWEST THIS AFTERNOON AND
CONTINUE INTO TONIGHT.

&&

.MARINE...
ISSUED AT 253 PM EST TUE FEB 2 2016

WINDS ALREADY STARTING TO CRANK UP OUT OF THE EAST AHEAD OF AN
APPROACHING DEEP SFC LOW PRESSURE. THESE EASTERLY WINDS WILL BRING
SOLID ADVISORY LEVEL SPEEDS...WITH LOW END GALES FUNNELING THROUGH
THE STRAITS REGION. THIS IS A FAIRLY BRIEF PERIOD OF GALES...AS THE
SFC LOW WILL CROSS DIRECTLY THROUGH NRN MICHIGAN WEDNESDAY MORNING.
WINDS WILL QUICKLY DROP OFF TO MORE VARIABLE UNDER 10KTS...BEFORE NW
WINDS AND COLD ADVECTION BRING ADVISORY LEVEL GUSTS BACK INTO THE
PICTURE FOR LATER WEDNESDAY AND WEDNESDAY NIGHT. WINDS WEAKEN SOME
INTO THE WEEKEND BUT WILL REMAIN GUSTY DUE TO OVERALL UNSTABLE
CONDITIONS.

EXPECT SNOW TO MIX WITH SLEET AND RAIN THROUGH EVENING...BEFORE
BECOMING DRIZZLE WITH SOME FOG DEVELOPMENT OVERNIGHT AND INTO
WEDNESDAY MORNING.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LH...SMALL CRAFT ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
     LHZ349.

     GALE WARNING UNTIL 5 AM EST EARLY THIS MORNING FOR LHZ345>348.

LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
     LMZ323-344>346.

     GALE WARNING UNTIL 5 AM EST EARLY THIS MORNING FOR LMZ341-342.

LS...NONE.
&&

$$

UPDATE...SULLIVAN
NEAR TERM...DICKSON
SHORT TERM...SWR
LONG TERM...KAB
AVIATION...SULLIVAN
MARINE...DICKSON


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