Area Forecast Discussion
Issued by NWS Gaylord, MI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KAPX 211126
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
726 AM EDT THU AUG 21 2014

.SYNOPSIS...
ISSUED AT 502 AM EDT THU AUG 21 2014

UPPER LEVEL LOW PRESSURE WILL MEANDER TOWARD NEW ENGLAND TODAY...
ALLOWING WEAK HIGH PRESSURE TO MAKE A BRIEF PUSH INTO NORTHERN
MICHIGAN. THAT WILL BRING ABOUT A MAINLY DRY AND SEASONABLE
DAY...BEFORE CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN TONIGHT
INTO FRIDAY. ADDITIONAL SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS
WILL CONTINUE EACH DAY THROUGH EARLY NEXT WEEK...AS SEVERAL WEAK
SYSTEMS TRACK NEARBY.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 502 AM EDT THU AUG 21 2014

...MORNING CLOUDS AND SOME AFTERNOON SUN/RAIN THREAT INCREASES
TONIGHT...

HIGH IMPACT WEATHER POTENTIAL: CHANCE FOR THUNDERSTORMS TONIGHT
MAINLY NORTHWEST LOWER.  HEAVY RAINFALL POTENTIAL IS THERE BUT WILL
BE HIGHLY DEPENDENT ON WHERE GREATEST CONCENTRATION OF THUNDERSTORMS
DEVELOP WHICH AT THIS POINT LOOKS TO BE DOWNSTATE.

PATTERN SYNOPSIS/FORECAST: MIDNIGHT SURFACE/COMPOSITE ANALYSIS SHOWS
A 1012MB SURFACE LOW OVER SOUTHWEST ONTARIO...WITH A FRONT THAT
LOOPS BACK TO THE SOUTH AND WEST ACROSS SOUTHERN LOWER MICHIGAN/
SOUTHERN WISCONSIN.  A SECOND FRONT EXTENDS ACROSS SOUTH DAKOTA/
IOWA/CENTRAL ILLINOIS/SOUTHERN INDIANA.  PARENT UPPER LOW SPINNING
NEAR THE NORTH CHANNEL...WITH A SHORT WAVE RIDGE AXIS ACROSS
NORTHWEST ONTARIO/UPPER MIDWEST.  PRECIPITATION HAS PUSHED EAST OF
MICHIGAN EARLY THIS MORNING...WITH A SCATTERED BAND OF CONVECTION
DEVELOPING ACROSS FAR SOUTHWEST LOWER/NORTHERN INDIANA/NORTHERN
ILLINOIS WITHIN AN ELONGATED ZONE OF WARM ADVECTION/MOISTURE
CONVERGENCE IN VICINITY OF THE ABOVE MENTIONED FRONTAL BOUNDARIES.
LOW CLOUDS HAVE MOSTLY OVERSPREAD EASTERN UPPER/NORTHERN LOWER
MICHIGAN...GETTING SOME DRIZZLE FORMING IN SPOTS AS WELL.

WHILE SHORT WAVE RIDGE OVER THE UPPER MIDWEST SLIDES EAST TODAY AND
TONIGHT...THE FRONTAL BOUNDARY EXTENDING FROM SOUTH DAKOTA AND
ACROSS THE MIDWEST WILL SLOWLY LIFT NORTHEAST TODAY...AND IS
EXPECTED TO BE A FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT
THROUGH TONIGHT.

PRIMARY FORECAST CONCERNS: AFTER DEALING WITH INITIAL CLOUD COVER
AND FOG...HOW CLOSE THAT SHOWER/THUNDERSTORM DEVELOPMENT GETS TO
NORTHERN MICHIGAN (AND RESULTANT QPF) WILL BE THE PRIMARY FOCUS FOR
THE SHORT TERM FORECAST.

TODAY/TONIGHT...EXPECT CLOUDS WILL BE SLOW TO THIN ESPECIALLY ACROSS
EASTERN UPPER AND A GOOD CHUNK OF NORTHEAST LOWER TODAY...AND WILL
LIKELY SEE SOME DEBRIS CIRROSTRATUS FROM UPSTREAM CONVECTION.  WOULD
THINK THAT FOR THE MOST PART TODAY WILL REMAIN DRY...BUT EASTWARD
MOVING CONVECTION OVER CENTRAL/SOUTHERN MINNESOTA DOES PRESENT SOME
CONCERN.  INSTABILITY WANES OVER NORTHEAST WISCONSIN/MICHIGAN...AND
MCS MAY BEING TO PROPAGATE MORE SOUTHEAST OVER THE NEXT SEVERAL
HOURS.  SO FOR NOW...OUTSIDE OF CURRENT DRIZZLE...WILL KEEP THE
AFTERNOON DRY HIGHS MAINLY IN THE 70S.

WARM FRONT LIKELY TO PUSH NORTHEAST SLOWLY (ESPECIALLY IF CONVECTION
CAN CONTINUALLY REINFORCE THE COOL SIDE OF THE BOUNDARY)...EXPECTING
BOUNDARY TO REACH SOUTHERN WISCONSIN/SOUTHERN LOWER MICHIGAN
OVERNIGHT.  GIVEN STRENGTH OF WARM ADVECTION INTO THE UPPER
MISSISSIPPI VALLEY WOULD EXPECT SHOWERS AND STORMS TO CONTINUE
ACROSS THESE AREAS THROUGH THE DAY...AND THIS ACTIVITY WILL PUSH
TOWARD LOWER MICHIGAN BY LATE IN THE DAY.  HOW CONVECTION EVOLVES IS
ALWAYS THE TRICKY PART...SINCE STORMS WILL PROBABLY TEND TO
PROPAGATE SOUTHEAST WILL NEED CONVECTION TO DEVELOP PRETTY FAR NORTH
INTO THE COOL AIR TO HAVE A SIGNIFICANT IMPACT ON NORTHERN
MICHIGAN.  THIS MAY BE TOUGH IF CONVECTION CLOSER TO THE WARM FRONT
TURNS OUT TO BE THE MAIN SHOW TO THE DETRIMENT OF ACTIVITY FARTHER
NORTH.  BUT LOCATION OF MOST PERSISTENT CONVECTIVE ACTIVITY IS
CRUCIAL WITH THE BIG CONCERN BEING PRECIPITATION POTENTIAL
(PRECIPITABLE WATER 1.50-2.00 INCHES MOVING INTO LOWER MICHIGAN/
K INDICES 35-40/DEEP WARM CLOUD LAYER WITH FREEZING LEVELS ABOVE 14K
FEET).  AT THIS POINT...APPEARS THAT BETTER HEAVY RAIN POTENTIAL
WILL BE ACROSS SOUTHERN WISCONSIN/SOUTHERN LOWER MICHIGAN...BUT THIS
WILL CERTAINLY NEED TO BE WATCHED FOR HEAVIER ACTIVITY TRYING TO
SNEAK IN SOUTHWEST PORTIONS OF THE FORECAST AREA.  PRECIP CHANCES
SHOULD TAPER OFF THE FARTHER NORTHEAST YOU GO.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 502 AM EDT THU AUG 21 2014

...FEELING A LOT MORE LIKE LATE SUMMER...

HIGH IMPACT WEATHER POTENTIAL: A COUPLE CHANCES FOR THUNDERSTORMS
THROUGH THE ENTIRE FORECAST PERIOD...BUT CONFIDENCE IS VERY LOW.

PATTERN SUMMARY: LISTEN UP SUMMER WEATHER FANS! JUST IN TIME FOR THE
FINAL FEW DAYS OF METEOROLOGICAL SUMMER...IT APPEARS AS IF SUMMER
WILL ACTUALLY MAKE AN APPEARANCE ACROSS NORTHERN MICHIGAN. THAT WILL
ALL COME COURTESY OF A PATTERN CHANGE...FEATURING DEEP UPPER
TROUGHING OVER THE WESTERN CONUS BECOMING REINFORCED WITH TIME...
FAVORING RATHER SUBSTANTIAL DOWNSTREAM HEIGHT RISES OVER THE EASTERN
CONUS AND GREAT LAKES THIS WEEKEND AND EARLY NEXT WEEK. THAT FEATURE
MAY BE FLATTENED FOR A TIME TOWARD MIDWEEK AS SOME SEMBLANCE OF THE
WESTERN TROUGH ATTEMPTS TO FLATTEN THE NORTHERN FRINGE OF THE
RIDGE...BUT WITH SOME HINTS THAT WE MAY FIND OURSELVES BENEATH
ANOTHER ROUND OF BURGEONING UPPER RIDGE SOMETIME LATE NEXT WEEK OR
INTO THE LABOR DAY HOLIDAY WEEKEND.

A LOOK AT THE FORECAST DETAILS...

FRIDAY-SUNDAY NIGHT: STILL QUITE A BIT OF FORECAST UNCERTAINTY
REGARDING THE EVOLUTION OF CONVECTION...THOUGH WHEN ISN`T THAT THE
CASE THIS FAR NORTH?. BASED ON THE LATEST DATA AND CLIMO IN THESE
TYPES OF SETUPS...GETTING A FAIRLY STRONG VIBE THAT NORTHERN
MICHIGAN MAY ESCAPE THE MAJORITY OF WIDESPREAD CONVECTION THROUGH
THE WEEKEND. WITH THAT SAID THOUGH...THE CHANCES AREN`T ZERO...WITH
THE BEST "CHANCES" FOCUSED ON FRIDAY AND AGAIN SOMETIME TOWARD
SUNDAY OR SUNDAY NIGHT. THE SIMPLE PROCESS OF RIDGE AMPLIFICATION
WILL SLOWLY DRIVE AN ELEVATED WARM FRONT NORTHWARD WITH TIME THROUGH
THE WEEKEND...WITH QUITE THE SUMMERLIKE PLUME OF WARMTH...MOISTURE...
AND INSTABILITY EXPANDING FROM THE MID MISSISSIPPI VALLEY/CENTRAL
PLAINS TOWARD THE LOWER LAKES.

JUST FROM A PATTERN RECOGNITION STANDPOINT...AND BACKED UP BY THE
LATEST 00Z GUIDANCE TRENDS...JUST NOT FEELING VERY GOOD ABOUT PRECIP
CHANCES ON FRIDAY. NORTHWARD BOWING WARM FRONT SHOULD EASILY GET
INTERCEPTED BY ONE OR MORE ROUNDS OF CONVECTION EMANATING ALONG THE
STRONG INSTABILITY GRADIENT FROM SOUTHERN WISCONSIN DOWN THROUGH THE
OHIO VALLEY. THAT LEAVES NORTHERN MICHIGAN IN NO MAN`S LAND...WITH A
VERY LIGHT FLOW REGIME AND LITTLE IN THE WAY OF ANY MOISTURE
ADVECTION...NOT TO MENTION POTENTIALLY CAPPED ON THE NORTHERN FRINGE
OF DEPARTING CONVECTION INTO MIDDAY FRIDAY. CAN`T RULE OUT SOME
CONVECTION ON THE NORTHERN FRINGE OF MORE ORGANIZED ACTIVITY
SCRAPING SOUTHWEST COUNTIES FRIDAY MORNING...AND ALSO CAN`T
COMPLETELY SAY THERE WON`T BE A ROGUE DIURNAL SHOWER OR STORM
BUBBLING UP FRIDAY AFTERNOON IN WEAK INSTABILITY UP THIS WAY.
HOWEVER...IN MY MIND...JUST NOT WORTH A WIDESPREAD BLANKET POP FOR
SUCH A LOWER PROBABILITY SETUP.

SIMILARLY...NOT FEELING VERY OPTIMISTIC ABOUT FRIDAY NIGHT GIVEN THE
LACK OF ANY FORCING FEATURE...OR SATURDAY AS THE LOW LEVEL FLOW
VEERS A BIT MORE EASTERLY...HELPING TAP INTO LOWER THETA-E AIR
ACROSS ONTARIO. THAT TREND HAS BEEN PRETTY WELL-ESTABLISHED FOR A
FEW RUNS NOW...AND GIVEN THAT DRY CONDITIONS ARE THE MORE LIKELY
OUTCOME...REALLY PREFER TO CAN THE GOING POPS...THOUGH MAY HAVE TO
WATCH FOR SOME SNEAKY LOWER STRATUS AT SOME POINT THROUGH THE
PERIOD. OUR BEST CHANCE FOR RAIN...IF ONE CAN CALL IT THAT...MAY
COME SOMETIME TOWARD SUNDAY OR SUNDAY NIGHT AS THE RIDGE AXIS
AMPLIFIES OVERHEAD...THEORETICALLY LIFTING THE BEST MOISTURE
GRADIENT BACK NORTH TOWARD OUR NECK OF THE WOODS. AS HAS BEEN STATED
A THOUSAND TIMES THE PAST FEW DAYS...THIS IS CONVECTION WE`RE
DEALING WITH AND CONFIDENCE IS QUITE LOW...BUT GOING SMALLER POPS
SHOULD DO THE TRICK.

MONDAY-WEDNESDAY: STILL LOWER CONFIDENCE BUT THE GENERAL TREND
SHOULD BE FOR A GRADUAL EASTWARD DRIFT OF THE WESTERN TROUGH...BUT
WITH THIS FEATURE MORE THAN CERTAINLY WEAKENING WITH TIME AS IT
BUTTS INTO SUCH STRONG AMBIENT RIDGING. THE TIMING OF AN ASSOCIATED
COLD FRONT HAS NOT SURPRISINGLY SLIPPED BY MORE THAN 48 HOURS OVER
RECENT DAYS...AND SUSPECT THAT TREND MAY CONTINUE A BIT MORE...WITH
SAID BOUNDARY PERHAPS ARRIVING SOMETIME TOWARD WEDNESDAY. PRIOR TO
THAT TIME...CAN`T COMPLETELY RULE OUT SOME DIURNAL CONVECTION MONDAY
AND TUESDAY AFTERNOONS...BUT ALSO HAVING A BIG ISSUE WITH MODEL DEW
POINTS SOARING WELL INTO THE 70S. INSTEAD...A MORE REASONABLE MIXED
PARCEL YIELDS VALUES MORE LIKELY IN THE MID OR UPPER 60S...
SUGGESTIVE OF AT LEAST SOME SEMBLANCE OF WEAK LOWER LEVEL CAPPING TO
OVERCOME PER MODIFIED FORECAST RAOBS. HATE THE CLUTTER UP THE
FORECAST WITH LOW PROBABILITY POPS WHEN MORE THAN LIKELY MOST AREAS
WON`T SEE MUCH IF ANY PRECIP...BUT SOME POPS ARE PROBABLY WARRANTED
CLOSER TO MIDWEEK WHEN WE PERHAPS SEE THE APPROACH OF A COLD FRONT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 723 AM EDT THU AUG 21 2014

VFR CONDITIONS EXPECTED AT MBL/TVC THROUGH THIS AFTERNOON...WITH
SHOWERS/THUNDERSTORMS POSSIBLE TONIGHT. IFR CONDITIONS AT APN/PLN
WILL IMPROVE TO MVFR OVER THE NEXT COUPLE OF HOURS...THEN SHOULD
BECOME VFR DURING THE AFTERNOON.

&&

.MARINE...
ISSUED AT 502 AM EDT THU AUG 21 2014

A WEAK PRESSURE GRADIENT WILL RESIDE OVER THE WATERS THROUGH THE
WEEKEND...PROVIDING AN EXTENDED STRETCH OF LIGHT WINDS MAINLY LESS
THAN 10 KNOTS AND LOW WAVES. A COUPLE CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL BE NOTED...PARTICULARLY TONIGHT INTO EARLY
FRIDAY...BUT WITH THE MOST WIDESPREAD AND INTENSE ACTIVITY EXPECTED
TO IMPACT THE LOWER GREAT LAKES THROUGH SUNDAY. LOCALIZED DENSE FOG
IS A POSSIBILITY AT TIMES AS WELL...AS MUCH MORE HUMID AIR CONTINUES
TO MARCH NORTH ACROSS THE COLDER WATER. WINDS MAY INCREASE A BIT
EARLY NEXT WEEK...AHEAD OF A COLD FRONT WORKING THROUGH THE UPPER
MIDWEST.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.

&&

$$

SYNOPSIS...LAWRENCE
SHORT TERM...JPB
LONG TERM...LAWRENCE
MARINE...LAWRENCE





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.