Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 291752
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
152 PM EDT WED OCT 29 2014

.SYNOPSIS...
ISSUED AT 356 AM EDT WED OCT 29 2014

LOW PRESSURE LIFTING INTO QUEBEC TODAY WILL DRAG A WEAK COLD FRONT
THROUGH THE REGION...DELIVERING ANOTHER ROUND OF COOLER TEMPERATURES
ALONG WITH PERIODIC LAKE EFFECT RAIN SHOWERS. THOSE WILL END TONIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE BRIEFLY ARRIVES. A STRONG COLD
FRONT WILL QUICKLY DROP THROUGH THE AREA THURSDAY NIGHT INTO EARLY
FRIDAY...USHERING IN VERY WINDY AND COLD CONDITIONS FOR HALLOWEEN...
AS WELL AS A PERIOD OF RAIN CHANGING TO SNOW FOR MANY AREAS. DRY BUT
CHILLY WEATHER IS EXPECTED HEADING INTO THE WEEKEND...WITH OUR NEXT
CHANCE FOR RAIN HOLDING OFF UNTIL EARLY NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1041 AM EDT WED OCT 29 2014

NO MAJOR CHANGES AT THIS TIME EXCEPT FOR TO INCREASE COVERAGE OF
LAKE EFFECT RAIN SHOWERS ACROSS NORTHWEST LOWER INTO THE EARLY
AFTERNOON HOURS. DRIER AIR SHOULD BEGIN FILTERING INTO THE REGION
BY LATER THIS AFTERNOON DIMINISHING ACTIVITY DESPITE CONTINUED
DECENT OVER LAKE INSTABILITY.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 356 AM EDT WED OCT 29 2014

OVERVIEW: DEEP OCCLUDING SFC LOW PRESSURE SYSTEM AND ATTENDING
CLOSED UPPER LOW RACING NORTHEASTWARD AWAY FROM THE GREAT
LAKES...CENTERED JUST EAST OF JAMES BAY. COLD/OCCLUDED FRONT ALREADY
WELL EAST OF THE REGION OF COURSE. BUT TRAILING SFC TROUGH AXIS IS
IN THE PROCESS OF SWINGING DOWN THROUGH UPPER MICHIGAN WITH WINDS
TURNING SHARPLY NORTH BEHIND THE TROUGH PULLING DOWN CORE OF COLDEST
AIR. SMALLER SECONDARY SHORT WAVE ALSO NOTED SWINGING EASTWARD OUT
OF GREEN BAY AND WE/VE ALREADY SEEN AN UPTICK IN SHOWERS ACROSS NRN
LOWER MICHIGAN IN ADVANCE OF THIS FEATURE (COMBINED WITH STEEPER LOW
LEVEL LAPSE RATES NOW OVERSPREADING THE REGION). MEANWHILE...
ASSOCIATED WRAP AROUND/DEFORMATION AXIS NOW SWINGING BACK ACROSS
LAKE SUPERIOR ALTHOUGH FORCING HAS BEEN WEAKENING AND ASSOCIATED
PRECIP DIMINISHING AS EVIDENCED BY WARMING CLOUD TOPS SEEN ON IR
SATELLITE IMAGERY.

THIS MORNING...SECONDARY SFC TROUGH AXIS WILL SWING ACROSS THE CWA
EARLY THIS MORNING TURNING WINDS NW AND PULLING COLDEST AIR INTO THE
REGION...H8 TEMPS FALLING OFF TO -3C TO -5C ACROSS NRN MICHIGAN.
THIS WILL KEEP DAYTIME MAX TEMPS IN THE LOWER TO MIDDLE 40S FOR MOST
AREAS ALTHOUGH SE COUNTIES TOWARD SAGINAW BAY MAY REACH THE UPPER
40S WITH DOWNSLOPING NW FLOW AND PERHAPS A LITTLE SUN LATER TODAY.
PRECIP-WISE...MID LEVEL TROUGH AXIS SWINGS THROUGH EARLY THIS
MORNING BRINGING JUST A BRIEF PERIOD OF QG-UPWARD FORCING. BUT THE
MAIN PLAYER WILL BE THE INCREASING INSTABILITY OVER THE LAKES. WITH
CYCLONIC FLOW AND DEEPENING MIXED LAYER AND PLENTY OF MOISTURE...
EXPECT LAKE EFFECT/ENHANCED RAIN SHOWERS TO TAKE OFF THIS MORNING
ACROSS EASTERN UPPER AND NW LOWER MICHIGAN.

THIS AFTERNOON THROUGH TONIGHT...LOW-MID LEVELS BEGIN TO DRY OUT AS
EARLY AS THIS AFTERNOON AND ESPECIALLY TONIGHT  AS UPSTREAM SFC
RIDGE EASES INTO THE WESTERN GREAT LAKES AND LOW LEVEL FLOW WEAKENS
AND BEGINS TO BACK MORE WESTERLY BY THURSDAY MORNING. SHOWERS START
TO WIND DOWN AS EARLY AS MID TO LATE AFTERNOON ALTHOUGH MINOR LAKE
EFFECT PRECIP WILL PROBABLY LINGER ACROSS EASTERN UPPER AND NW LOWER
MICHIGAN THROUGH TONIGHT AS LOW LEVELS CERTAINLY REMAIN COLD ENOUGH.
QUESTION IS...P-TYPE. FORECAST SOUNDINGS ACROSS NRN LOWER MICHIGAN
KEEP FREEZING LEVELS JUST ABOVE 2K FEET MSL SUGGESTING JUST RAIN
THROUGH TONIGHT...ALTHOUGH SOME SNOWFLAKES IN THE HIGH TERRAIN NOT
OUT OF THE QUESTION. LOWER FREEZING LEVELS TONIGHT IN EASTERN
UPPER...DOWN AROUND 1600 FEET OR SO SUGGESTS SNOW OR AT LEAST A
RAIN/SNOW MIX.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 356 AM EDT WED OCT 29 2014

...LOOK OUT BELOW! HERE COMES THE COLD AIR...

HIGH IMPACT WEATHER POTENTIAL: INCREASING POTENTIAL FOR A BURST OF
SNOW MANY AREAS HALLOWEEN MORNING. STRONG WINDS ALSO POSSIBLE
FRIDAY...WITH A CHANCE FOR GALES ON PARTS OF THE GREAT LAKES.

PATTERN SYNOPSIS/EVOLUTION: WELL...IT HAD TO HAPPEN AT SOME POINT
THIS FALL...AND LOVE IT OR HATE IT...THAT TIME IS NOW. CURRENT
ANALYSIS PLACES A CLOSED LOW SPINNING OVER THE GULF OF ALASKA...WITH
A RATHER POTENT 150 KNOT MID LEVEL JET DIVING DOWN THE WESTERN SIDE
AND HELPING AMPLIFY THIS FEATURE SOUTHWARD WITH TIME OVER THE PAST
24 HOURS. MEANWHILE MEAN TROUGHING OF COURSE RESIDES FROM HUDSON BAY
DOWN INTO THE GREAT LAKES...BUT WITH A COUPLE OF ADDITIONAL
REINFORCING SHORTWAVES TRANSITING SOUTHWARD FROM THE NORTHWEST
TERRITORIES/WESTERN NUNAVUT INTO THE BACK SIDE OF SAID TROUGH.
CONTINUED DEEPENING OF GULF OF ALASKA TROUGHING THE NEXT FEW DAYS
WILL RAPIDLY HELP BUILD RIDGING THROUGH THE CANADIAN ROCKIES...
EFFECTIVELY OPENING THE DOOR FOR RAPID SOUTHWARD RE-AMPLIFICATION OF
TROUGHING INTO THE GREAT LAKES...WITH THE PASSAGE OF A STRONG COLD
FRONT FRIDAY MORNING USHERING IN THE COLDEST AIR OF THE SEASON SO
FAR. THAT PATTERN LOOKS TO BE SHORT-LIVED AS STRONGER JET ENERGY
HELPS PUNT GULF OF ALASKA TROUGHING INLAND...DISLODGING THE TROUGH
EASTWARD AND ALLOWING FOR RISING HEIGHTS ACROSS THE GREAT LAKES INTO
EARLY NEXT WEEK. HOWEVER...EVENTUALLY THE WESTERN TROUGH WILL HEAD
EAST...LIKELY TOWARD MIDWEEK BUT WITH PLENTY OF UNCERTAINTY
REGARDING THE OVERALL AMPLITUDE OF THE PATTERN TOWARD MIDWEEK.

LET`S LOOK AT THE DETAILS:

THURSDAY-FRIDAY: HERE COMES THE FUN WEATHER! LOW LEVEL RIDGING LOOKS
TO DOMINATE WITH DRY WEATHER THE FIRST HALF OF THURSDAY. HOWEVER...
QUICKLY APPROACHING WILL BE QUITE THE SHARP UPPER WAVE (ALREADY
CLEARLY EVIDENT OVER THE NORTHWEST TERRITORIES) DROPPING TOWARD THE
WESTERN LAKES. BACKING FLOW INTO THIS FEATURE SHOULD HELP TIGHTEN AN
AXIS OF FRONTOGENESIS EASTWARD ACROSS THE U.P. THROUGH THE
AFTERNOON...ALL WHILE MOISTURE DEEPENS SUFFICIENTLY TO PRODUCE AN
EXPANDING AREA OF PRECIPITATION...ALONG AND JUST BEHIND THE ACTUAL
STRONG SURFACE COLD FRONT. THERE REMAIN SOME MINOR GUIDANCE
DISCREPANCIES REGARDING THE SPECIFICS...THOUGH CONFIDENCE IS
INCREASING IN A QUICK SHOT OF PRECIP FOR ALL AREAS VERY LATE
THURSDAY AFTERNOON INTO THURSDAY NIGHT...HELPED ALONG BY QUITE THE
STRONG SHOT OF UPWARD FORCING/DYNAMICS ARRIVING WITH THE UPPER
TROUGH.

FROM A PRECIP TYPE STANDPOINT...MOST AREAS SHOULD START OFF AS
LIQUID WITH A WARMER BOUNDARY LAYER AND FREEZING LEVELS UP ABOVE
2KFT. HOWEVER...STRONG COLD ADVECTION INTO THE REGION BETWEEN 09-13Z
STRONGLY ARGUES FOR MANY SPOTS EXPERIENCING A QUICK TURNOVER AS
FREEZING LEVELS CRASH BELOW 1KFT (NEAR THE SURFACE EASTERN UPPER AND
HIGHER TERRAIN AREAS). THE KEY OF COURSE WILL BE JUST HOW MUCH
PRECIP IS LEFT BY THIS POINT...BUT REALLY GETTING THE FEELING THAT
AT LEAST A BURST OF SNOW IS ENTIRELY POSSIBLE FOR MANY AREAS FOR A
TIME THROUGH MID/LATE MORNING FRIDAY. LAKE ENHANCEMENT ALSO A GOOD
BET WITH H8 TEMPS DIVING TOWARD -10C OR COLDER WHILE THE LOW LEVEL
FLOW BECOMES NORTH/NORTHEASTERLY. STRONG DRYING IN THE POST-FRONTAL
ENVIRONMENT ARGUES FOR A TRANSITION TO MORE OF A PURE LAKE EFFECT
SETUP INTO FRIDAY AFTERNOON...BUT DESPITE GUIDANCE DEPICTIONS OF DRY
WEATHER...HAVE A SNEAKY SUSPICION WE WILL BE DEALING WITH DIURNALLY
ENHANCED SNOW SHOWERS ENCOMPASSING MUCH OF AT LEAST NORTHERN LOWER
THROUGH THE DAY.

GIVEN SUCH A SHOT OF DYNAMICS AND COOLING LOW LEVELS...SOME
ACCUMULATION CERTAINLY APPEARS POSSIBLE...PARTICULARLY INTO EASTERN
UPPER AND INTO THE HIGHER TERRAIN AREAS...BUT ANY HEAVIEST BURSTS
COULD OF COURSE LAY DOWN A QUICK COATING JUST ABOUT ANYWHERE. BASED
ON TRENDS OF A STRONGER SYSTEM AND AFOREMENTIONED STRONG FORCING...
HAVE TO WONDER IF WE COULD SQUEEZE OUT AN INCH OR TWO FOR THE HIGH
SPOTS AND WILL START THE TREND OF BEEFING UP ACCUMULATION...IN LINE
WITH WPC EXPECTATIONS AND PATTERN RECOGNITION...DESPITE WARMER
GROUND TEMPS. WINDS ALSO AN ISSUE WITH MIXED LAYER WINDS UP TO 35
KNOTS SUPPORTING SOME PRETTY HEFTY GUSTS AS DOWNWARD TRANSPORT IN
STRONG COLD ADVECTION KICKS INTO GEAR. ALL IN ALL...THIS HAS SOME
POTENTIAL FOR A SNEAKY EVENT TO CAUSE SOME TRAVEL TROUBLES PROVIDED
SNOW PANS OUT AS EXPECTED...AS GIVEN HEAVY RATES...A SLUSHY
ACCUMULATION ON ROADS ISN`T TOTALLY IMPOSSIBLE.

FRIDAY NIGHT-SUNDAY NIGHT: DRYING OUT BUT STAYING CHILLY AS DEEPER
UPPER TROUGHING SLOWLY PULLS AWAY AS WE`RE LEFT WITH RISING HEIGHTS
ALOFT WHILE ELONGATED LOW LEVEL RIDGING WORKS THROUGH THE REGION.
PERSISTENT NORTH TO NORTH/NORTHEAST FLOW AROUND THE PERIPHERY OF
SAID LOW LEVEL RIDGING COMBINED WITH PLENTY COLD LOW LEVELS SHOULD
MAINTAIN SOME LAKE SNOW SHOWERS (MIXED WITH RAIN AT THE COAST?)
CLOSER TO THE LAKE HURON COAST FRIDAY NIGHT...BUT WITH THAT THREAT
ENDING INTO SATURDAY AS THE FLOW BECOME LIGHT/ANTICYCLONIC AND WE
LOSE THE BEST INSTABILITY. CLOUDS LIKELY TO BE PESKY AT TIMES
(ESPECIALLY SATURDAY) AND LIMITED MIXING MANDATES TEMPS WILL REMAIN
ON THE CHILLY SIDE...SETTING UP A CHILLY NIGHT SATURDAY NIGHT WITH
LIGHT WINDS AND A TREND TOWARD CLEARING SKIES.

MONDAY-TUESDAY: BETTER PUSH OF WARM ADVECTION/RETURN FLOW LOOKS TO
GET INTO GEAR EARLY NEXT WEEK OUT AHEAD OF ADDITIONAL UPPER
TROUGHING WORKING THROUGH THE PLAINS. WHILE TIMING AND PLACEMENT OF
THAT WAVE REMAINS IN QUESTION...THE END RESULT SHOULD BE INCREASING
CHANCES FOR ANOTHER ROUND OF SHOWERS SOMETIME LATER MONDAY OR MONDAY
NIGHT...WITH OF COURSE A PUSH OF THICKER CLOUDS AS SAID WARM
ADVECTION CRANKS UP AS WELL. THE THERMAL REGIME APPEARS IT WILL
MODERATE SUFFICIENTLY TO MITIGATE ANY THREAT FOR FROZEN
PRECIPITATION...THOUGH OVERALL TEMPS MAY WELL REMAIN ON THE CHILLY
SIDE PENDING THE TIMING OF CLOUDS AND PRECIP.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 148 PM EDT WED OCT 29 2014

SYNOPTICALLY DRIVEN MOISTURE IS STRIPPING OUT AT THE MOMENT AS
STORM SYSTEM RACES OFF TO THE NORTHEAST. STILL MARGINAL LAKE
EFFECT CONDITIONS THROUGH THIS EVENING POSSIBLY LEADING TO A FEW
SHOWERS. DRIER AIR THEN LOOKS TO ADVECT IN OVERNIGHT INTO THURSDAY
MORNING YIELDING A BREAK IN THE ACTION OUT AHEAD OF ANOTHER SYSTEM
LATER THURSDAY INTO THURSDAY NIGHT. CIGS ARE EXPECTED TO BE JUST
ABOVE MVFR THROUGH THE TAF PERIOD...THROUGH TEMPORARY IFR CIGS ARE
POSSIBLE AT TIMES...MAINLY AT TVC AND MBL. NORTHWEST WINDS WILL
DIMINISH LATER TODAY THEN BECOME LIGHT AND VARIABLE TONIGHT WITH
LIGHT WEST SOUTHWEST WINDS DEVELOPING THURSDAY.

&&

.MARINE...
ISSUED AT 429 AM EDT WED OCT 29 2014

ANOTHER SURGE OF COOLER AIR WORKING ACROSS THE WATERS WILL CONTINUE
TO PROVIDE PERIODS OF SMALL CRAFT ADVISORY WINDS AND WAVES
TODAY...ABATING QUICKLY THIS EVENING AND TONIGHT AS HIGH PRESSURE
APPROACHES. WINDS WILL REMAIN LIGHT RIGHT ON INTO THURSDAY BEFORE
RAPIDLY SWITCHING TO THE NORTH AND INCREASING SUBSTANTIALLY ON
FRIDAY AS A STRONG COLD FRONT ARRIVES. DEEP MIXING OF QUITE STRONG
FLOW ALOFT WITH VERY COLD AIR WORKING OVER THE WATERS SUGGESTS GALE
FORCE WINDS ARE LIKELY ON LAKE MICHIGAN...AND PERHAPS ON LAKE HURON
AS WELL. CONDITIONS WILL SETTLE DOWN THROUGH THE WEEKEND AS HIGH
PRESSURE AGAIN BUILDS BACK INTO THE REGION.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LHZ345>349.
     GALE WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY NIGHT FOR
     LHZ348-349.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ323-341-
     342-344>346.
     GALE WARNING FROM 5 AM TO 11 PM EDT FRIDAY FOR LMZ323-342-
     344>346.
LS...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LSZ321-322.

&&

$$

UPDATE...AS
SYNOPSIS...LAWRENCE
SHORT TERM...ADAM
LONG TERM...LAWRENCE
AVIATION...AS
MARINE...LAWRENCE






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