Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 142309
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
709 PM EDT SUN SEP 14 2014

.SYNOPSIS...
ISSUED AT 401 PM EDT SUN SEP 14 2014

A WEAK SURFACE FEATURE NORTH OF LAKE SUPERIOR...WILL GENERATE SOME
RAIN SHOWERS AND COOL TEMPERATURES ACROSS NORTHERN MICHIGAN TONIGHT
AND MONDAY.

OTHERWISE...A LARGE AREA OF HIGH PRESSURE ORGANIZING OVER THE
PLAINS WILL MOVE TOWARD THE GREAT LAKES MONDAY...BEFORE SETTLING
OVER THE STATE WEDNESDAY. THIS PATTERN WILL GENERATE SOME SUN AND
SLOWLY WARMING TEMPERATURES ACROSS NORTHERN MICHIGAN DURING THE
WORK WEEK.

&&

.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 401 PM EDT SUN SEP 14 2014

...RAIN THREAT INCREASES THIS EVENING...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: LATEST SURFACE/COMPOSITE ANALYSIS SHOWS
1012MB SURFACE LOW NORTH OF THE MINNESOTA ARROWHEAD...ALONG WITH A
SUPPORTING SHORT WAVE TROUGH AND JET STREAK.  TRAILING COLD FRONT
INTO THE UPPER MIDWEST...WITH HIGH PRESSURE STRETCHING FROM THE
LOWER GREAT LAKES TO THE OHIO VALLEY.  BAND OF SHOWERS ASSOCIATED
WITH UPSTREAM COLD FRONT JUST CLIPPING CENTRAL UPPER WITH THE
MAJORITY OF THE PRECIPITATION ACROSS LAKE SUPERIOR AND POINTS
NORTH.  SOME OFF-AND-ON INSTABILITY SHOWERS HAVE BEEN ONGOING ACROSS
CHIPPEWA/MACKINAC COUNTIES MUCH OF THE DAY.

COLD FRONT EXPECTED TO SLIP INTO NORTHERN MICHIGAN TONIGHT...WHILE
UPSTREAM JET STREAK STRETCHES ACROSS LOWER MICHIGAN.  THIS FEATURE
COMBINED WITH ANOTHER SHORT WAVE TROUGH DIGGING SOUTHEAST ACROSS THE
DAKOTAS AND TOWARD THE UPPER MIDWEST WILL SET UP AN ELONGATED
LOW/MID LEVEL FRONTOGENESIS AXIS THAT IS EXPECTED TO REACH LOWER
MICHIGAN AFTER MIDNIGHT.

PRIMARY FORECAST CONCERNS: ARLY PRECIPITATION ALONG COLD FRONT TO
THE NORTH...AND LATER PRECIPITATION WITH DEVELOPING FRONTOGENESIS
AXIS.

TONIGHT...INITIAL BROKEN AREA OF SHOWERS ACROSS CENTRAL UPPER
MICHIGAN ALONG TAIL END OF SHORT WAVE TROUGH MOVING ALONG THE NORTH
SHORE OF LAKE SUPERIOR WILL IMPACT THE EASTERN HALF OF THE UPPER
PENINSULA THROUGH MID/LATE EVENING.  ALSO HAVE TO CONSIDER THE
POSSIBILITY OF THIS BAND OF PRECIPITATION EXTENDING SOUTH INTO
NORTHERN LAKE MICHIGAN WITH STEEPENING LOW LEVEL LAPSE RATES AND LOW
LEVEL CONVERGENCE AIDING THE CAUSE.  SO WILL STRETCH EVENING POPS
SOUTHWARD INTO THE TIP OF THE MITT AND NORTHWEST LOWER SHORELINE
COUNTIES TO ACCOUNT FOR THIS POSSIBILITY.  BEYOND THIS...COMBINATION
OF FRONTOGENETIC AXIS AND RIGHT ENTRANCE REGION JET FORCING IS
EXPECTED TO GENERATE AN AREA OF RAIN ACROSS SOUTHERN MINNESOTA/
NORTHERN IOWA/SOUTHERN WISCONSIN DURING THE EVENING HOURS...ALREADY
SOME SEMBLANCE OF THESE PROCESSES GETTING GOING ACROSS SOUTH DAKOTA/
NORTHWEST IOWA.  PRECIPITATION EXPECTED TO "STREAK" EASTWARD AND
INTO CENTRAL LOWER MICHIGAN AFTER MIDNIGHT.  SO OVERALL ALL AREAS
WILL SEE SOME PRECIP THREAT TONIGHT BETWEEN THE FRONT/SHORT WAVE
TROUGH AND APPROACHING F-GEN/JET FORCING. CLOUD COVER WILL BE
VARIABLE ACROSS NORTHERN LOWER EARLY ON AS AFTERNOON DIURNAL
CLOUDS GET PUSHED EAST...SO SOME EARLY EVENING CLEARING FOR MUCH
OF NORTHERN LOWER BEFORE COLD FRONT/INSTABILITY CLOUDS SPREAD BACK
INTO NORTHWEST LOWER.

.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 401 PM EDT SUN SEP 14 2014

...MOSTLY GREAT EARLY FALL WEATHER...

HIGH IMPACT WEATHER POTENTIAL: NOT MUCH. PERHAPS A FROST THREAT
TOWARD MIDWEEK...BUT SOME QUESTIONS ARE BEGINNING TO ARISE ABOUT
CLOUD COVER.

PATTERN SUMMARY: WHO DOESN`T LOVE EARLY FALL IN NORTHERN MICHIGAN?
IF YOU DON`T LIKE ONE TYPE OF WEATHER...JUST STICK AROUND FOR A DAY
OR TWO AND YOU GET ENTIRELY DIFFERENT CONDITIONS. THE NEXT 7-14 DAYS
LOOK TO HIGHLIGHT THAT IDEA QUITE WELL AS WE AT LEAST BRIEFLY
TRANSITION OURSELVES BACK TO SOME LATE SUMMER/EARLY FALL WARMTH
HEADING TOWARD THE WEEKEND. AT THE MOMENT...BROAD UPPER TROUGHING
CONTINUES TO ENCOMPASS MUCH OF THE GREAT LAKES REGION AND WILL BE
ENHANCED THROUGH THE EARLY WORK WEEK AS ANOTHER UPPER VORT DIVES
THROUGH THE SOUTHERN LAKES ON MONDAY. A COUPLE OF ADDITIONAL
REINFORCING PIECES OF ENERGY LOOK TO WORK ACROSS ONTARIO THROUGH
MIDWEEK...HELPING DELIVER CONTINUED PERSISTENT UPPER TROUGHING FOR
OUR AREA...WHILE CLOSED LOW PRESSURE RECENTLY SPINNING NEAR THE
ALEUTIANS SLOWLY ADVANCES EASTWARD...HELPING PUNT WESTERN RIDGING
FURTHER INLAND. THIS FEATURE WILL EVENTUALLY MAKE A RUN AT THE
NORTHERN LAKES TOWARD LATE WEEK AND AT LEAST PART OF THE WEEKEND...
THOUGH ONLY BECAUSE ADDITIONAL UPPER ENERGY WILL BE HOT ON ITS TAIL
THROUGH THE NORTHERN PLAINS. THAT TROUGH MAY MAKE A RUN BACK AT OUR
NECK OF THE WOODS SOMETIME LATE IN THE WEEKEND OR EARLY NEXT WEEK.

A LOOK AT THE FORECAST DETAILS:

MONDAY: SECONDARY UPPER TROUGH IS EXPECTED TO PASS THROUGH THE
AREA...WITH THE BETTER UPPER FORCING SLIDING THROUGH THE LOWER LAKES
INTO THE AFTERNOON. AT THE SURFACE...WEAK LOW PRESSURE OVER HUDSON
BAY WILL PUSH A COLD FRONT THROUGH THE AREA DURING THE MORNING...
WITH THIS FEATURE EFFECTIVELY STALLING/WASHING OUT ACROSS CENTRAL
LOWER INTO THE AFTERNOON. DECENT LITTLE MID LEVEL FGEN RESPONSE
COMBINED WITH A MODEST CORRIDOR OF UPPER JET SUPPORT SHOULD DRIVE A
STRUNG OUT BAND OF LIGHT RAIN FROM ABOUT M-72 ON SOUTH THROUGH
SOUTHERN LOWER...WITH THIS STUFF FIRST HAVING TO OVERCOME A MODESTLY
DRY AIR MASS AT THE ONSET. STILL...SIMPLY BASED ON THE PATTERN AND
OUR PROPENSITY LATELY TO RAIN JUST ABOUT ANY TIME WE CAN...HAVE TO
BELIEVE HIGHER POPS ARE WARRANTED FOR SOUTHERN COUNTIES...AND WILL
BUMP THINGS TO LIKELY RANGE AS MEASURABLE PRECIP IS EXPECTED.

FARTHER NORTH...CAN`T RULE OUT SOME DIURNALLY DRIVEN SHOWERS POPPING
UP BENEATH THE UPPER HEIGHT/THERMAL TROUGH...PARTICULARLY ACROSS THE
CENTRAL U.P. (JUST OUTSIDE OUR CWA) WHERE LOW LEVEL CONVERGENCE WILL
BE MAXIMIZED AHEAD OF THE INCOMING LOW LEVEL RIDGE. THAT SAME
CONVERGENCE AXIS MAY LAY OUT INTO EASTERN UPPER AS WELL...WITH A
SMATTERING OF SHOWERS CERTAINLY POSSIBLE IN AN AXIS OF 100-200J/KG
SBCAPE. AFTERNOON TEMPS ARE TRICKY FOR THE AREA WITH CLOUD ISSUES
AND THE ONSET OF WEAKISH LOW LEVEL COLD ADVECTION THROUGH THE
AFTERNOON. SHOULD SEE AT LEAST SOME BREAKS NORTH OF THE BETTER
SOUTHERN RAIN SHIELD...SUGGESTING HIGHS INTO THE UPPER 50S ARE
POSSIBLE...PROBABLY SLIGHTLY COOLER SOUTH OF M-72 WHERE PERIODIC
LIGHT RAIN IS EXPECTED.

MONDAY NIGHT-WEDNESDAY: DRYING OUT MONDAY NIGHT INTO TUESDAY AS HIGH
PRESSURE SLIPS THROUGH THE LOWER LAKES BUT EXHIBITS A GREAT
INFLUENCE ON OUR WEATHER. INCOMING AIR MASS DOESN`T LOOK QUITE COOL
ENOUGH TO DELIVER ANY PESKY LAKE EFFECT CLOUDS...THOUGH CERTAINLY A
LITTLE CU LOOKS POSSIBLE TUESDAY AFTERNOON BENEATH RESIDUAL COOLER
AIR ALOFT. SHOULD BE A REALLY NICE DAY TUESDAY WITH HIGHS PUSHING
THE LOWER 60S THANKS TO ADDED SUNSHINE...AFTER A COOL/COMFORTABLE
START IN THE UPPER 30S TO LOW 40S. STILL NOT VERY WORRIED ABOUT
FROST POTENTIAL MONDAY NIGHT AS WE LOOK TO MAINTAIN SOME SEMBLANCE
OF A GRADIENT THROUGH THE NIGHT.

THINGS GET A LITTLE MORE INTERESTING INTO WEDNESDAY AS ANOTHER
SHORTWAVE DROPS THROUGH SOUTHERN ONTARIO...ADVANCING A BACKDOOR COLD
FRONT THROUGH AT LEAST PART OF THE AREA. OF COURSE CONFIDENCE IN
TIMING AND PLACEMENT OF THE BOUNDARY IS STILL QUITE LOW THIS FAR
OUT...BUT GETTING THE FEELING SOME AREAS ACROSS THE NORTH MAY BE
STUCK BENEATH THICKER CLOUDS WITH A SNEAKY VERY CHILLY DAY POSSIBLE
AS STRONG BUT SHALLOW SUB-850MB COLD ADVECTION KICKS INTO GEAR. IN
ADDITION...CAN`T COMPLETELY RULE OUT A FEW SHOWERS FIRING OFF IN A
NARROW AXIS OF TIGHTENING FRONTOGENESIS SOMEWHERE ACROSS THE
NORTHERN HALF OF THE CWA. AGAIN...CONFIDENCE IS LOW ENOUGH TO
PRECLUDE ANY MENTION AT THIS POINT BUT CERTAINLY SOMETHING TO WATCH.

WEDNESDAY NIGHT-FRIDAY: MAINLY QUIET AS LOW LEVEL RIDGING WORKS
ACROSS ONTARIO AND DOWN INTO THE NORTHEAST. STILL WATCHING WEDNESDAY
NIGHT AS A POSSIBLE VERY CHILLY NIGHT. GUIDANCE TRENDS HAVE SHOWN A
TENDENCY TO BACK AWAY FROM THE STRONGER HIGH EARLIER PROGGED TO OUR
NORTH...BUT THE SETUP STILL LOOKS DECENT TO GOOD RADIATIONAL COOLING
AS THE RIDGE AXIS POKES OVERHEAD THROUGH THE NIGHT. CLOUDS WILL BE
THE KICKER...ESPECIALLY WITH A TENDENCY FOR SHALLOW COLD AIR TO
DRAPE ITSELF OVER NORTHERN MICHIGAN...PERHAPS FAVORING SOME LAKE
HURON STRATUS ROLLING INLAND ON AN EASTERLY FLOW. STILL MORE THAN
WORTH AN HWO/WEB STORY MENTION AND WILL CONTINUE TO WATCH.
OTHERWISE...LOOKS QUITE NICE BOTH THU AND FRI (AGAIN...BARRING ANY
PESKY LAKE CLOUDS) WITH HIGHS WARMING BACK THROUGH THE
60S...ESPECIALLY FRIDAY AS STRONGER RETURN FLOW GETS UNDERWAY.

FRIDAY NIGHT-SUNDAY: STRENGTHENING PUSH OF THERMAL AND MOISTURE
ADVECTION ARRIVES SOMETIME LATER FRIDAY NIGHT OR SATURDAY WITH
PROBABLY A ROUND OF SHOWERS AND PERHAPS EVEN THUNDER. AT THE
MOMENT...IT APPEARS A COLD FRONT WILL MAKE A RUN AT THE AREA
SOMETIME SUNDAY...WITH ANOTHER ROUND OF RAIN...THOUGH THE EXACT
TIMING OF ALL THIS REMAINS SOMEWHAT LOWER CONFIDENCE. ONE THING THAT
APPEARS MORE CERTAIN IS TEMPS WARMING BACK TO NORMAL OR EVEN ABOVE
NORMAL LEVELS...AND PENDING THE TIMING OF CLOUDS AND PRECIP...IT
ISN`T IMPOSSIBLE SOME SPOTS COULD PUSH WELL INTO THE 70S FOR A TIME
THIS WEEKEND AHEAD OF THE INCOMING COLD FRONT.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 709 PM EDT SUN SEP 14 2014

VFR CONDITIONS ARE EXPECTED TONIGHT DESPITE THE DEVELOPMENT OF
SCATTERED SHOWERS ACROSS NW LWR MICHIGAN (ESPECIALLY PLN) AS A
WEAK WAVE COMBINES WITH OVER-LAKE INSTABILITY AND SW LOW LEVEL
FLOW. CONDITIONS WILL DETERIORATE TO MVFR ON MONDAY AS WIDESPREAD
RAIN DEVELOPS MAINLY ALONG AND SOUTH OF M-32 THANKS TO THE ARRIVAL
OF A STRONGER WAVE ALONG A COLD FRONT SURGES INTO LWR MICHIGAN. SW
WINDS UNDER 10 KTS TONIGHT WILL SHIFT TO THE NW AT AROUND 10 KTS
ON MONDAY.

&&

.MARINE...
ISSUED AT 401 PM EDT SUN SEP 14 2014

SMALL CRAFT ADVISORIES WILL STILL BE NEEDED WITHIN MOST LAKE
MICHIGAN NEARSHORE ZONES TONIGHT WITH BRISK SOUTHWEST WINDS AHEAD
OF AN APPROACHING COLD FRONT. FRONTAL PASSAGE LATER TONIGHT WILL
ALLOW WINDS TO SHIFT TO THE WEST AND DIMINISH...WITH
WEST/NORTHWEST WINDS EXPECTED MONDAY.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EDT MONDAY FOR LMZ341-342-
     344>346.
LS...NONE.

&&

$$

SYNOPSIS...SWR
SHORT TERM...JPB
LONG TERM...LAWRENCE
AVIATION...MR
MARINE...JPB





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