Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 220248
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
948 PM EST FRI NOV 21 2014

.SYNOPSIS...
ISSUED AT 308 PM EST FRI NOV 21 2014

HIGH PRESSURE ACROSS THE OHIO VALLEY TODAY WILL SLIDE OFF TO THE
ATLANTIC COAST BY SATURDAY. SOUTHWEST FLOW AROUND THE BACKSIDE OF
THIS SYSTEM WILL DRAW WARMER AIR UP INTO THE REGION HEADING INTO
THE WEEKEND. HOWEVER...AS THE WARMER AIR ARRIVES...THERE WILL BE A
PERIOD OF LIGHT FREEZING RAIN OR DRIZZLE LATER TONIGHT THROUGH
SATURDAY MORNING. A STRONG STORM SYSTEM SLIDES UP THROUGH THE
REGION SUNDAY INTO MONDAY BRINGING A PERIOD OF RAIN. BUT MUCH COLDER
AIR SPILLS BACK INTO THE REGION ON MONDAY AND MONDAY NIGHT...WITH
ANOTHER PROLONGED PERIOD OF LAKE EFFECT SNOWS ANTICIPATED THROUGH
MUCH OF NEXT WEEK.

&&

.UPDATE...
ISSUED AT 948 PM EST FRI NOV 21 2014

STRONG SW LOW-LEVEL FLOW IN PLACE ACROSS MI...WITH SEVERAL GALE
FORCE GUSTS SEEN OVER LAKE MI AND THE ADJOINING COASTLINE. MARINE
PLUME HAS TEMPS NEAR FREEZING AT FRANKFORT/BEAVER ISL/MANISTIQUE.
THE LOW LEVELS ARE STILL QUITE DRY AWAY FROM THAT MARINE
PLUME...MAINLY IN THE TEENS. THERE IS STILL SOME LAKE-INDUCED
STRATOCU ACROSS EASTERN UPPER...OTHERWISE THERE ARE NO LOW CLOUDS
HERE.

THAT MAKES THE FZDZ FORECAST PROBLEMATIC. THERE ARE LOW CLOUDS
UPSTREAM...WAY BACK IN FAR SOUTHERN WI AND POINTS S/W. OUR 925MB
WINDS ARE INCREASING TO NEAR 50KT...SO THOSE ARE GOING TO HUSTLE
INTO THE REGION FAST OVERNIGHT...BUT NOT QUITE AS FAST AS EARLIER
EXPECTED. HAVE THUS SLOWED THE POTENTIAL ONSET OF DZ/FZDZ BY A
SMIDGE. DZ WILL BE FAVORED NEAR LAKE MI...FZDZ ELSEWHERE.

NO CHANGES TO THE GOING HEADLINES. TEMPS WILL BE RISING
OVERNIGHT.

&&

.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 308 PM EST FRI NOV 21 2014

...THREAT FOR FREEZING DRIZZLE/LIGHT FREEZING RAIN AFTER MIDNIGHT...

HIGH IMPACT WEATHER POTENTIAL: SOME ICING ON ROADWAYS OVERNIGHT WITH
WIDESPREAD FREEZING DRIZZLE OR LIGHT FREEZING RAIN.

PATTERN SYNOPSIS/FORECAST: EARLY AFTERNOON SURFACE ANALYSIS SHOWS
1036MB CENTERED OVER SOUTHERN OHIO WITH ANTICYCLONIC WARM ADVECTION
TO ITS NORTH ACROSS MICHIGAN.  BACKING LOW LEVEL WINDS ASSOCIATED
WITH THIS HIGH IS PUSHING LINGERING LAKE INDUCED FLURRIES OFF LAKE
MICHIGAN AND INTO THE STRAITS REGION...OTHERWISE A MIX OF SUN AND
CLOUDS ACROSS NORTHERN MICHIGAN WITH WARM ADVECTION INDUCED MID/HIGH
CLOUDS SPILLING INTO THE UPPER LAKES.  STRONG SOUTHERLY RETURN FLOW
QUICKLY PULLING STRATUS NORTHWARD OUT OF KANSAS/MISSOURI...AHEAD OF
A SURGE OF 1+ INCH PRECIPITABLE WATER VALUES OVER THE LOWER
MISSISSIPPI VALLEY.  SHORT WAVE RIDGE AXIS MOVING THROUGH THE
MIDWEST... WITH A FLAT SHORT WAVE TROUGH CROSSING EASTERN KANSAS
WITH AN ASSOCIATED PV ANOMALY THAT EXTENDS EAST INTO THE TENNESSEE
VALLEY.

UPSTREAM SHORT WAVE TROUGH/PV ANOMALY WILL CONTINUE TO LIFT
NORTHEAST TOWARD LOWER MICHIGAN OVERNIGHT...AS WILL DEEP LAYER WARM
AIR AND MOISTURE SURGE (850MB TEMPERATURES WARMING ABOVE FREEZING BY
MORNING...PRECIPITABLE WATER NEAR THREE-QUARTERS OF AN INCH INTO
SOUTHERN LOWER MICHIGAN).

PRIMARY FORECAST CONCERNS: INCREASING PRECIPITATION THREAT TONIGHT
AND POSSIBILITY OF PRECIP TYPE ISSUES

TONIGHT: A QUIET START TO THE NIGHT WILL GIVE WAY TO QUICKLY
INCREASING LOW CLOUDS AFTER MIDNIGHT.  INITIAL SURGE OF MOISTURE
LOOKS TO BE PRETTY SHALLOW...BUT LOW LEVEL WARM ADVECTION AND
UPSLOPE FLOW COMBINED WITH A SHARP INCREASE IN LOW LEVEL MIXING
RATIOS WITH HEIGHT USUALLY A HARBINGER OF DRIZZLE.  LOOKS LIKE THIS
THREAT INCREASES FROM SOUTHWEST TO NORTHEAST DURING THE EARLY
MORNING HOURS OF SATURDAY...AND WITH SURFACE TEMPERATURES AWAY FROM
LAKE MICHIGAN LIKELY TO STILL BE BELOW FREEZING THEN FREEZING
DRIZZLE AND ICING WILL BE THE CONCERN.  SO WILL MATCH UP WITH
SOUTHERN OFFICES AND ISSUE A FREEZING RAIN ADVISORY FOR ALL OF
NORTHERN LOWER MICHIGAN WITH VARYING START/END TIMES DEPENDING ON
THREAT TIMING...EARLIEST ADVISORIES WILL START AT 06Z WITH NEXT
GROUP AT 09Z.

.LONG TERM...(SATURDAY THROUGH FRIDAY)
ISSUED AT 308 PM EST FRI NOV 21 2014

...A BREAK FROM THE COLD THEN RIGHT BACK IN IT NEXT WEEK...

OVERVIEW: THREE WAVE LONG WAVE PATTERN AROUND THE NRN HEMISPHERE
TODAY WITH CROSS POLAR TROUGHINESS FROM ASIA OVER THROUGH EASTERN
CANADA...AND DEEPENING TROUGHINESS THROUGH ALASKA AND THE EASTERN
PACIFIC. NRN HEMISPHERIC PATTERN HAS/IS UNDERGOING A BIT OF DE-
AMPLIFICATION...WITH A STRONG PACIFIC JET/SHORT WAVE (CURVING AROUND
THAT ABOVE MENTIONED ALASKAN TROUGH) ABOUT TO PLOW INTO THE WEST
COAST OF NOAM AND FORCING A DOWNSTREAM FLATTER FLOW ACROSS THE CONUS
AND THE NORTHWARD RETREAT OF OUR PERSISTENT DEEP TROUGHINESS/COLD
AIR. THERE IS A BIT OF A SPLIT IN THE FLOW TODAY OVER THE WESTERN
CONUS WITH ANOTHER PIECE OF SHORT WAVE ENERGY ROLLING THROUGH THE SW
CONUS TODAY THAT WILL EVENTUALLY RE-PHASE WITH THE PACIFIC ENERGY
LATE IN THE WEEKEND.

PATTERN FORECAST: SO...A FLATTER/PROGRESSIVE FLOW PATTERN WILL BE
THE STORY FOR THE SHORTER TERM...AGAIN FORCING CORE OF COLD AIR BACK
INTO NRN CANADA FOR THIS WEEKEND AND ALLOWING WARMER MORE SEASONABLE
AIR THATS BEEN BOTTLED UP ACROSS THE WESTERN CONUS TO SPREAD
EASTWARD THROUGH THE LOWER 48 (A TRANSITION THAT IS  ALREADY
UNDERWAY TODAY). BUT GIVEN OUR NEWLY ACQUIRED SNOWPACK OVER A GOOD
CHUNK OF NRN MICHIGAN...THAT WILL INTRODUCE ANOTHER SET OF ISSUES
AS RAIN EVENTUALLY ENTERS THE PICTURE LATE IN THE WEEKEND INTO
MONDAY ON TOP OF A FAIRLY HEFTY SNOWPACK ACROSS THE SNOWBELTS.

BUT NOT TO WORRY...OUR WINTER FUN IS NOT OVER YET. LARGE SCALE FLOW
PATTERN IS FORECAST TO ONCE AGAIN BECOME HIGHLY AMPLIFIED HEADING
THROUGH NEXT WEEK...WITH THE PATTERN ESSENTIALLY REVERTING BACK TO
THE APPARENT NEW STANDARD...THAT IS STRONG RIDGING ALONG THE WEST
COAST AND DEEP TROUGHINESS/COLD AIR INTRUDING DOWN THROUGH CANADA
ACROSS THE GREAT LAKES. AND OF COURSE WITH SUCH A PATTERN
CHANGE...HAS TO BE SOME SORT OF STRONG STORM SYSTEM TO HELP FORCE
THE CHANGE. THAT SYSTEM WILL ROLL UP THROUGH THE REGION LATE SUNDAY
INTO MONDAY AND INITIALLY BRING THAT AFOREMENTIONED RAINFALL...BUT
THEN FOLLOWED BY ANOTHER BOUT OF LAKE EFFECT SNOW LATE MONDAY INTO
TUESDAY AS THE COLD AIR RETURNS TO THE REGION.

AS FAR AS SPECIFICS GO FOR THE SHORTER TERM...SATURDAY IS SORT OF AN
"IN BETWEEN" DAY. DEEP SW FLOW AND ONGOING WARM ADVECTION FORCING
WILL ALREADY BE IN PLACE FROM THE GULF UP THROUGH THE GREAT
LAKES...ON THE BACKSIDE OF HIGH PRESSURE THAT WILL BE PERCHED ALONG
THE ATLANTIC COAST...DRIVING ELEVATED WARM LAYER AND 0C H8 LINE UP
THROUGH NRN MICHIGAN. INITIALLY...A FAIRLY DRY ATMOSPHERE WILL ALSO
BE IN PLACE EARLY ON ACROSS THE GREAT LAKES (LOTS OF CLEAR SKIES
BACK ACROSS THE MIDWEST TODAY). BUT NOTE BATCH OF EXPANDING LOW-MID
CLOUD COVER (AND SOME SHOWER ACTIVITY) WITHIN BULGE OF WARM AIR OVER
EASTERN TEXAS INTO THE LOWER MISSISSIPPI RIVER VALLEY TODAY...WHICH
GUIDANCE SUGGESTS WILL GET PULLED UP INTO THE WESTERN GREAT LAKES ON
SATURDAY. JUST HOW FAR NORTH THE DEEPER MOISTURE GETS (THAT WOULD
SUPPORT MEASURABLE PRECIP) REMAINS TO BE SEEN. NAM/GFS SOLUTIONS
SUGGEST DEEPER MOISTURE SLIDES UP THROUGH SRN/CENTRAL LOWER
MICHIGAN JUST GRAZING THE M-55/M-72 CORRIDORS BUT KEEPING
MEASURABLE PRECIP MOSTLY OUT OF THIS CWA. BUT MEANWHILE...STRONG
WARM ADVECTION ALOFT SHOVED OVER A RETREATING SHALLOW COLD AIRMASS
(AND SNOWPACK ACROSS THE NRN STATES) SHOULD LEAD TO EXPANDING LOW
CLOUDS/STRATUS ACROSS THE REGION BY SATURDAY WHILE MODEL SOUNDINGS
CERTAINLY SUGGEST FZDZ TO DZ POSSIBILITIES THROUGH THE DAY. MAY BE
ENOUGH TO CAUSE SOME TRAVEL HEADACHES ACROSS THE REGION THROUGH
SATURDAY MORNING UNTIL SFC TEMPS CAN CLAW BACK ABOVE FREEZING.

BIGGER ISSUE WILL BE PRECIP TYPE SATURDAY MORNING. TEMPERATURES
TONIGHT WILL FALL BACK INTO THE TEENS TO MIDDLE 20S AND WILL BE SLOW
TO RECOVER TO ABOVE FREEZING READINGS SATURDAY IN SPITE OF STRONG
WARM ADVECTION RAMPING UP JUST OFF THE SFC...PARTICULARLY ACROSS THE
HIGHER TERRAIN AND WHERE THERE IS APPRECIABLE SNOWPACK. OF COURSE
TIMING IS EVERYTHING BUT THINK THERE WILL BE A PERIOD OF LIGHT
FREEZING DRIZZLE FOR MANY AREAS SATURDAY MORNING AND A PERIOD OF
LIGHT FREEZING RAIN ACROSS THE SRN COUNTIES.

SATURDAY NIGHT...DEEPER MOISTURE PEELS OFF TO THE EAST/SOUTHEAST
WHICH WILL LARGELY END ANY MEASURABLE PRECIP THREAT. BUT A SOUPY LOW
LEVEL AIRMASS WILL REMAIN WITH TEMPS AND DEWPOINTS STAYING JUST
ABOVE FREEZING THROUGH THE NIGHT. THIS WILL LEND ITSELF TO PATCHY
DRIZZLE AND AREAS OF FOG.

SUNDAY THROUGH MONDAY...TURNS A BIT MORE INTERESTING. STRONG SHORT
WAVE ENERGY IN THE PAC NW TODAY BEGINS TO PHASE WITH ENERGY OVER THE
SW CONUS...AND BEGINS THE PROCESS OF CARVING OUT ANOTHER DEEP TROUGH
THROUGH THE NATIONS MIDSECTION BY MONDAY WITH ANOTHER INTRUSION OF
COLD AIR DROPPING INTO THE PLAINS. AHEAD OF THE TROUGH...DEEP LOW
PRESSURE LOOKING TO SPIN UP OVER THE LOWER LAKES AND ADVANCE UP
THROUGH THE STATE SUNDAY NIGHT INTO MONDAY. A SUBSTANTIAL SLUG OF
RAINFALL IS POSSIBLE AS THE SYSTEM ESSENTIALLY DEEPENS OVERHEAD AND
WE GET A PERIOD OF COMBO UPPER JET ENTRANCE REGION FORCING AND WARM
ADVECTION FORCING SLIDING UP THROUGH THE REGION...WITH PRECIP
AMOUNTS OF HALF TO ONE INCH POSSIBLE. BUT ALL ANTICIPATED RIGHT NOW
AT LEAST (UNTIL PERHAPS LATE MONDAY AFTERNOON AS THE SYSTEM IS
DEPARTING. BUT REGARDLESS...A DECENT RAINFALL ON TOP OF AN EXISTING
SNOWPACK/SNOW COVERED ROADS MIGHT POSE SOME TRAVEL ISSUES. WE WILL
JUST HAVE TO SEE HOW MUCH SNOW REMAINS ON AREA ROADS BY SUNDAY
AFTERNOON AFTER A GOOD 24 HOURS OF ABOVE FREEZING TEMPS/DEWPOINTS.

MONDAY NIGHT THROUGH TUESDAY...HERE WE GO AGAIN. DEEP LOW PRESSURE
SYSTEM DEPARTS ON TO THE NORTHEAST DRAGGING FIRST FIRST CORE OF COLD
AIR INTO THE WESTERN GREAT LAKES...WHILE WRAP AROUND DEFORMATION
FORCING/SNOWFALL SLIDES THROUGH THE REGION MONDAY NIGHT THROUGH
TUESDAY MORNING. SNOW/LAKE ENHANCED SNOW...ALL COMBINED WITH VERY
GUSTY WINDS THROUGH TUESDAY WILL LIKELY PROMPT ANOTHER ROUND OF
WINTER WEATHER HEADLINES THROUGH THAT TIME.

LATER PERIODS (WEDNESDAY THROUGH FRIDAY)...RIGHT BACK INTO FULL BORE
WINTER TO FINISH OFF THE WEEK AS ANOTHER FOLLOW-UP CORE OF ARCTIC
AIR (-20C OR COLDER AT H8/-35C OR COLDER AT H5) DESCENDS INTO THE
GREAT LAKES LATE WEDNESDAY INTO THURSDAY. ANOTHER PIECE OF
ENERGY/SFC LOW PRESSURE MAY ALSO BE PASSING THROUGH THE REGION
DURING THAT TIME. BUT IN THE END...MUCH OF NEXT WEEK IS SHAPING UP
TO BE BE ANOTHER PROLONGED PERIOD OF LAKE EFFECT/LAKE ENHANCED SNOWS
TO VARYING DEGREES. BEST CHANCES LOOK TO OCCUR LATER WEDNESDAY
THROUGH THURSDAY...ALTHOUGH WHATEVER WEATHER SYSTEM IS MOVING
THROUGH WILL OF COURSE HAVE AN IMPACT ON WIND DIRECTIONS AND JUST
WHAT AREAS SEE THE MOST.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 701 PM EST FRI NOV 21 2014

CIGS DESCEND TO IFR/MVFR OVERNIGHT WITH DZ/FZDZ. LLWS.

HIGH PRESSURE WAS OVER THE MID ATLANTIC COAST THIS EVENING...WITH
LOW PRESSURE NEARING FAR NW ONTARIO. IN BETWEEN...SW LOW-LEVEL
FLOW IS STRENGTHENING IN THE LAKES REGION. LOW LEVEL MOISTURE WILL
RAPIDLY BE TRANSPORTED NORTHWARD...RESULTING IN STRATUS AND
DZ/FZDZ DEVELOPMENT OVERNIGHT. FOR NOW...WITH DOWNSLOPING SW
WINDS...HAVE KEPT APN WITH MVFR CIGS AND NO DZ/FZDZ MENTION.
TVC/MBL/PLN SHOULD SEE IFR CIGS AND RISK FOR FZDZ/DZ ARRIVE AFTER
06Z. AS WE WARM FURTHER...ALL PRECIP WILL TURN TO DZ ON
SATURDAY...THOUGH CIGS WILL REMAIN LOW.

S TO SW SURFACE WINDS THRU THE FORECAST. LLWS THRU THE
FORECAST...WITH STRONG SW WINDS JUST OFF THE DECK.


&&

.MARINE...
ISSUED AT 308 PM EST FRI NOV 21 2014

HIGH PRESSURE OVER THE OHIO VALLEY WILL SLIDE OFF TO THE ATLANTIC
COAST. STRONGER SW FLOW AROUND THIS SYSTEM WILL BRING GALE FORCE
WIND GUSTS TO LAKE MICHIGAN TONIGHT INTO SATURDAY...WHILE WARMER
AIR QUICKLY SPREADS UP INTO THE REGION. WINDS WILL WEAKEN A BIT
LATER SATURDAY INTO SUNDAY WHILE BACKING MORE SOUTHERLY. MOST
MARINE HEADLINES SHOULD BE ALLOWED TO DROP BY LATE SATURDAY INTO
SUNDAY.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...FREEZING RAIN ADVISORY FROM 1 AM TO NOON EST SATURDAY FOR MIZ021-
     022-027>029-032>036-041-042.

     FREEZING RAIN ADVISORY FROM 1 AM TO 7 AM EST SATURDAY FOR MIZ020-
     025-026-031.

     FREEZING RAIN ADVISORY FROM 4 AM TO NOON EST SATURDAY FOR
     MIZ016>019-023-024-030.

LH...SMALL CRAFT ADVISORY UNTIL 5 PM EST SATURDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST SATURDAY FOR LMZ323.

     GALE WARNING UNTIL 10 AM EST SATURDAY FOR LMZ341-342-344>346.

LS...SMALL CRAFT ADVISORY UNTIL 5 PM EST SATURDAY FOR LSZ321-322.

&&

$$

UPDATE...JAZ
SYNOPSIS...ADAM
SHORT TERM...JPB
LONG TERM...ADAM
AVIATION...JAZ
MARINE...ADAM



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