Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 212300
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
700 PM EDT TUE OCT 21 2014

.SYNOPSIS...
ISSUED AT 341 PM EDT TUE OCT 21 2014

HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE GREAT LAKES REGION
OVERNIGHT AND PERSIST THROUGH THE END OF THE WORK WEEK. THIS WILL PROVIDE A
RETURN TO DRY CONDITIONS AND A SLOW WARMING TREND INTO THE WEEKEND.

&&

.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 341 PM EDT TUE OCT 21 2014

...A TOUCH CHILLY TONIGHT...

HIGH IMPACT WEATHER POTENTIAL: NONE

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: LARGE SCALE PATTERN
UNFOLDING AS ANTICIPATED...WITH DEEPENING EASTERN LAKES TROUGH
GETTING READY TO SPAWN EAST COAST LOW PRESSURE...ALL-THE-WHILE STOUT
CENTRAL PLAINS RIDGING BEGINS ITS FOLDING PROCESS INTO THE NORTHWEST
LAKES. OVERHEAD HEIGHT REBOUND ALREADY NOTED...A PROCESS THAT WILL
CONTINUE TONIGHT INTO WEDNESDAY. SURFACE REFLECTION OF MID LEVEL
RIDGING JUST AS IMPRESSIVE...WITH ELONGATED HIGH PRESSURE EXTENDING
FROM CENTRAL QUEBEC BACK SOUTHEAST INTO THE CENTRAL PLAINS.

PRIMARY FORECAST CONCERNS: CLOUD AND TEMPERATURE TRENDS.

DETAILS: ONE CHALLENGING CLOUD FORECAST HEADING THROUGH TONIGHT. DRY
AIR INVASION CONTINUES...AND THAT ALONE WOULD SUPPORT CLEAR SKIES
OVERNIGHT. AS IS TYPICAL OF NORTHERN MICHIGAN...ALL IS NOT THAT
SIMPLE. NO DOUBT SURFACE HIGH PRESSURE RULES OVERNIGHT...ALTHOUGH
THE APEX OF WHICH REMAINS EXTENDING FROM NORTHEAST WISCONSIN UP INTO
CENTRAL QUEBEC. THIS SUPPORTS MAINTENANCE OF LIGHT EAST FLOW ACROSS
LAKE HURON. SUBSIDENCE INVERSION IS IMPRESSIVE...FURTHER
STRENGTHENED AS H9-H6 LEVELS SLOWLY WARM. TEMPERATURES JUST BELOW
INVERSION BASE (~H9 HEIGHT) STAY THE SAME OR EVEN COOL SLIGHTLY.
EXPECTED -2C READINGS AT THIS LEVEL MORE THAN COLD ENOUGH TO ENTICE
LAKE HURON MOISTURE CONTRIBUTION INTO THE NEAR SURFACE ENVIRONMENT.
NAM-WRF MOST AGGRESSIVE IN THIS REGARD...SHOWING ALMOST COMPLETE
SATURATION OVER NORTHEAST LOWER...ESPECIALLY ALONG AND EAST OF
INTERSTATE 75. PATTERN SUPPORTS SUCH...AND WILL CONTINUE TREND OF
THIS MORE PESSIMISTIC CLOUD FORECAST...WITH BELIEF STRATUS DECK WILL
FORM AND SPREAD INTO INTERIOR AREAS LATER TONIGHT. DOWNSLOPE FLOW
ACROSS EASTERN UPPER/NORTHWEST LOWER SHOULD KEEP SKIES CLEAR IN
THOSE REGIONS. TEMPERATURES ALL DEPENDENT ON THESE CLOUD TRENDS.
READINGS WELL INTO THE 20S A SAFE BET IN CLEAR AREAS...WHILE
NORTHEAST LOWER IS LIKELY TO STAY IN THE 30S. JUST ONE OF THOSE
TYPICAL OCTOBER NORTHERN MICHIGAN NIGHTS.

.LONG TERM...(WEDNESDAY THROUGH TUESDAY)
ISSUED AT 341 PM EDT TUE OCT 21 2014

...HEADING INTO A NICE STRETCH OF WEATHER THROUGH THE WEEKEND...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: PROGRESSIVE UPPER RIDGE AXIS OVER CENTRAL
NORTH AMERICA...FLANKED BY TROUGHING OVER EASTERN NORTH AMERICA AND
AN EXPANSIVE UPPER LOW OVER THE EASTERN PACIFIC.  SHORT WAVE TROUGH
WAS DIVING DOWN THE FRONT SIDE OF THE CENTRAL NORTH AMERICAN RIDGE
AND ACROSS THE LOWER GREAT LAKES...ANOTHER SHORT WAVE TROUGH WAS
LIFTING NORTHEAST ACROSS THE GREAT BASIN.  SURFACE HIGH PRESSURE WAS
CENTERED OVER NORTHERN ONTARIO RIDGING SOUTH INTO THE UPPER
MIDWEST...BOUNDARY LAYER FLOW INTO MICHIGAN GETTING SQUEEZED BETWEEN
THIS HIGH AND LOW PRESSURE OVER LAKE ONTARIO.  UPSTREAM SOUNDINGS
ACROSS NORTHERN ONTARIO FROM 12Z SHOW VERY DRY AIR ADVECTING INTO
THE UPPER GREAT LAKES.

WARM ADVECTION TO THE EAST OF THE UPPER RIDGE OVER HUDSON BAY/FAR
NORTHERN QUEBEC WILL ALLOW HEIGHT RISES TO PUSH EAST AND "FOLD" OVER
THE TOP OF THE GREAT LAKES SHORT WAVE TROUGH WHICH WILL CLOSE OFF
OVER THE MID ATLANTIC AS A RESULT.  GREAT LAKES WILL BE IN A BIT OF
A SQUEEZE PLAY BETWEEN THIS UPPER LOW AND THE GREAT BASIN SHORT WAVE
LIFTING INTO THE NORTHERN PLAINS/UPPER MIDWEST THURSDAY (THIS SHORT
WAVE TROUGH SLIDES ACROSS MICHIGAN FRIDAY).  ABOVE NORMAL HEIGHTS
EXPECTED TO PREVAIL ACROSS THE NATION`S MIDSECTION THIS WEEKEND WITH
A STRONG NORTHWESTERLY JET STREAK EXPECTED ACROSS THE UPPER LAKES.

PRIMARY FORECAST CONCERNS (NEAR TERM): PRETTY MINIMAL.  SOME CLOUD
COVER WEDNESDAY MORNING...THEN ANY RAIN CHANCE WILL WEAKENING SHORT
WAVE TROUGH LATER THURSDAY/THURSDAY NIGHT.

NEAR TERM (WEDNESDAY/THURSDAY): NORTHEAST BOUNDARY LAYER FLOW OFF
LAKE HURON WILL LIKELY KEEP SOME CLOUDS HANGING ACROSS NORTHEAST
LOWER TO START THE DAY WEDNESDAY...BUT SHOULD BE PRETTY SHALLOW BY
THAT POINT AND EXPECT THESE CLOUDS TO MIX OUT FAIRLY QUICKLY LEADING
TO A MOSTLY SUNNY AFTERNOON AND TEMPERATURES GETTING CLOSE TO
SEASONABLE VALUES.  CHILLY WEDNESDAY NIGHT WITH LOWS DIPPING INTO
THE 20S/LOWER 30S.

WATCHING A WEAKENING SHORT WAVE TROUGH COMING ACROSS THE UPPER
MIDWEST FOR THURSDAY...BUT TO START THE DAY LOWER MICHIGAN WILL BE
IN A NARROW DEFORMATION ZONE BETWEEN THIS UPPER WAVE AND A STORM
SYSTEM SPINNING UP OFF THE MID ATLANTIC COAST.  BUT AS OF NOW
THURSDAY ITSELF SHAPING UP TO BE ANOTHER NICE DAY WITH A FEW MORE
HIGH CLOUDS DURING THE AFTERNOON SPREADING IN FROM THE WEST...AND
WIDESPREAD HIGHS IN THE 50S.  BUT THERE ARE SOME DIFFERENCES IN
EVOLUTION OF THE APPROACHING SHORT WAVE TROUGH THURSDAY NIGHT
BETWEEN THE GFS WHICH DEPICTS A MORE ELONGATED/SHEARED WAVE SLOWLY
PUSHING INTO WESTERN LOWER MICHIGAN...AND THE NON-AMERICAN GUIDANCE
WHICH SPIN UP AN UPPER LOW OVER SOUTHWEST LOWER/NORTHERN ILLINOIS/
NORTHERN INDIANA.  A PROBABILISTIC APPROACH IS PROBABLY BEST
HERE...THOUGH HEADING INTO FRIDAY WILL PUSH THE FORECAST IN THE
DIRECTION OF THE SMALL UPPER LOW IDEA.  SMALL RAIN CHANCES PRIMARILY
WEST OF M-37 AND KEEPING THINGS DRY ELSEWHERE SHOULD BE A GOOD
COMPROMISE.

MEDIUM RANGE (FRIDAY/SATURDAY/SUNDAY):  LOOKING PRETTY BENIGN FROM A
SIGNIFICANT WEATHER STANDPOINT HEADING INTO THE WEEKEND...
NORTHWESTERLY JET STREAK WILL BE PASSING NEAR/NORTH OF MICHIGAN
SATURDAY...FOLLOWED BY SHORT WAVE RIDGING SUNDAY.  SO AFTER A MONTH
WHERE IT HAS RAINED PRETTY MUCH EVERY DAY (E.G., GAYM4 COOP HAS YET
TO RECORD A ZERO FOR DAILY PRECIPITATION THIS MONTH)...WILL BE NICE
TO HAVE A STRETCH OF DRY WEATHER AND TEMPERATURES A LITTLE ABOVE
AVERAGE FOR LATE OCTOBER.

OUTLOOK (MONDAY/TUESDAY): TROUGHING RETURNS TO THE PLAINS STATES FOR
EARLY NEXT WEEK...WITH SOUTHWEST WINDS ALOFT INTO THE MIDWEST/GREAT
LAKES.  RAIN THREAT LIKELY TO INCREASE FOR MONDAY/TUESDAY OF NEXT
WEEK...POTENTIALLY MILD AS WELL.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 700 PM EDT TUE OCT 21 2014

SCT/BKN LAKE-INDUCED LOW CLOUDS AND MVFR CIGS ARE EXPECTED TO PUSH
BACK INTO PORTIONS OF NE LWR MICHIGAN (APN) OVERNIGHT INTO EARLY
WEDNESDAY MORNING...BEFORE MIXING OUT BY MID MORNING. NW LWR
MICHIGAN (PLN/TVC/MBL) WILL REMAIN VFR THRU THE TAF FORECAST
PERIOD WITH LITTLE TO NO CLOUD COVER EXPECTED IN THIS AREA. WINDS
WILL REMAIN BLO 10 KTS FROM THE N/NE.

&&

.MARINE...
ISSUED AT 341 PM EDT TUE OCT 21 2014

PRESSURE GRADIENT EXPECTED TO CONTINUE TO WEAKEN AS HIGH
PRESSURE BUILDS INTO THE AREA. WINDS WILL SUBSIDE...BUT WILL TAKE
THEIR TIME DOING SO OVER NORTHERN LAKE HURON. WILL DROP INHERITED
SCA FOR LAKE MICHIGAN...WHILE EXTENDING THOSE ON LAKE HURON INTO THE
EVENING. OTHERWISE...AN EXTENDED PERIOD OF QUIET WEATHER AND MOSTLY
LIGHT WINDS IS EXPECTED FOR THE REMAINDER OF THIS WEEK AS HIGH
PRESSURE REMAINS IN CONTROL.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LHZ347>349.
LM...NONE.
LS...NONE.

&&

$$

SYNOPSIS...AM
SHORT TERM...MSB
LONG TERM...JPB
AVIATION...MR
MARINE...MSB






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