000
FXUS63 KAPX 191050
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
650 AM EDT SUN MAY 19 2013

.SYNOPSIS...
ISSUED AT 310 AM EDT SUN MAY 19 2013

HIGH PRESSURE WILL PROVIDE A LITTLE MORE SUNSHINE...THUS A BIT
WARMER TEMPERATURES FOR SUNDAY. HOWEVER...A STORM SYSTEM DEVELOPING
OVER THE ROCKIES WILL BECOME BETTER ORGANIZED OVER THE PLAINS...
BEFORE MOVING INTO THE GREAT LAKES TO START THE WORK WEEK. THIS
APPROACHING SYSTEM WILL GENERATE SHOWERS AND THUNDERSTORMS ACROSS
NORTHERN MICHIGAN THROUGH MID WEEK.

&&

.UPDATE...
ISSUED AT 650 AM EDT SUN MAY 19 2013

A FEW LIGHT SHOWERS CONTINUE TO LINGER ACROSS ERN UPR MICHIGAN
EARLY THIS MORNING. THE REST OF OUR CWA REMAINS DRY AND MAINLY
CLOUDY AS TEMPS HOLD MAINLY IN THE 50S. A FEW SHOWERS MAY DEVELOP
THIS AFTERNOON ACROSS INTERIOR SECTIONS OF NRN LWR MICHIGAN THANKS
TO INCREASING DIURNAL INSTABILITY. OTHERWISE...EXPECT A MAINLY DRY
AND PARTLY SUNNY DAY AS MID CLOUDS CONTINUE TO DRIFT OVERHEAD. LOW
LEVEL SE FLOW WILL ADVECT WARMER TEMPS INTO THE REGION TODAY...
WITH AFTERNOON HIGHS IN THE MID 70S TO LOWER 80S.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 310 AM EDT SUN MAY 19 2013

A GRADUAL STEP UP TOWARD A MUCH MORE ACTIVE PERIOD OF WEATHER BEGINS
TODAY...AS SOME SMALL SHOWER CHANCES ENTER THE FORECAST. THE TIMING
AND EVEN EXISTENCE OF THOSE LATER THIS AFTERNOON REMAINS THE PRIMARY
FORECAST ISSUE THROUGH SUNSET...WITH THE FOCUS SHIFTING TOWARD
POSSIBLE ADDITIONAL PRECIP CHANCES OVERNIGHT. THE EARLY MORNING
WEATHER MAP IS STILL A RATHER QUIET ONE FOR NORTHERN MICHIGAN...AS
EXPANSIVE LOW LEVEL RIDGING REMAINS DRAPED FROM NEWFOUNDLAND DOWN
INTO OUR NECK OF THE WOODS. OF MUCH BIGGER INTEREST IS A RATHER
HEALTHY LONGWAVE TROUGH SLOWLY LIFTING FROM THE SOUTHERN ROCKIES
ONTO THE PLAINS...WITH THIS SYSTEM HELPING DRIVE LEE CYCLOGENESIS
ACROSS WESTERN KANSAS WHILE ALSO KICKING OFF SEVERAL COMPLEXES OF
SHOWERS AND SEVERE STORMS. GRADUAL RAMPING UP OF MID LEVEL WARM
ADVECTION ASCENT WELL AHEAD OF THIS TROUGH CONTINUES TO FORCE AN
AXIS OF THICKER CLOUD COVER UP ACROSS THE U.P...WITH EVEN A FEW
SPITS OF RAIN FALLING AT TIMES...THOUGH HINDERED LARGELY BY A
SIGNIFICANT DRY WEDGE BELOW 750MB.

FOR TODAY...NOT MUCH TO SPEAK OF THIS MORNING WITH RIDGING DOWN LOW
STILL IN CONTROL...THOUGH LOSING ITS INFLUENCE WITH TIME AS THE
RIDGE CORE SLIDES OFF THE NORTHEAST COAST. MEANWHILE...SLIGHTLY
BETTER RETURN FLOW SHOULD GET UNDERWAY...PARTICULARLY THIS AFTERNOON
AS A WARM FRONT TRIES TO MAKE SOME NORTHWARD PROGRESS...ALL WHILE
STRONGER LOW PRESSURE TAKES SHAPE ACROSS SOUTH DAKOTA. THE QUESTION
IS WILL WE GET ENOUGH LOWER LEVEL MOISTURE BACK THIS FAR NORTH TO
AID IN FIRING OFF AT LEAST A FEW AFTERNOON SHOWERS. A FEW THINGS
WORKING IN OUR FAVOR INCLUDE DECENT DAYTIME HEATING EXPECTED...WITH
HIGHS WARMING WELL INTO THE 70S AND LOWER 80S...AND WHAT SHOULD BE
NUMEROUS LOCALIZED TRIGGERS/CONVERGENCE AS LAKE BREEZE DEVELOPMENT
BECOMES WIDESPREAD WITH A LIGHT GRADIENT.

WITH THAT SAID...ARRIVAL OF BUILDING SHORTWAVE RIDGING SQUARELY
OVERHEAD WITH TIME DOES GIVE ONE A LITTLE PAUSE WITH POSSIBLE
CAPPING ISSUES...AND THE FACT THAT GUIDANCE MOISTURE PROGS CAN`T BE
TRUSTED DOESN`T HELP. NAM/GFS DEPICTION OF SURFACE DEW POINTS WELL
INTO THE 60S JUST DOESN`T LOOK DOABLE GIVEN THE TRUE WARM FRONT WILL
LIKELY HOLD TO OUR SOUTH THROUGH THE DAY AS IT BENDS AROUND THE COLD
LAKE WATERS. INSTEAD...LOW OR MID 50S LOOK BETTER...SIMILAR TO
THOSE OBSERVED ACROSS NORTHERN INDIANA YESTERDAY. PER FORECAST
RAOBS...AN 80/55 PARCEL MIGHT JUST BE ABLE TO SQUEAK BY THE
CAP...BUT THAT DOESN`T LEAVE A WHOLE LOT OF AVAILABLE INSTABILITY...
EVEN WITH SOME DECENT (NOT GREAT) LAPSE RATES ARRIVING. THE LONG AND
SHORT OF IT IS THE CHANCE FOR A FEW SHOWERS IS NOT COMPLETELY
ZERO...ESPECIALLY WHERE LAKE BREEZE BOUNDARIES CAN PROVIDE SOME
BETTER MOISTURE POOLING...BUT IT`S CERTAINLY NOTHING HIGHER THAN
ABOUT 20 PERCENT. WILL CONTINUE TO HAVE A MENTION BUT CONFIDENCE IS
NOT VERY HIGH. EASTERN UPPER MIGHT ACTUALLY STAND A BETTER SHOT
WITH THE LEAD INVERTED TROUGH AXIS/WARM FRONT PROVIDING SLIGHTLY
BETTER CONVERGENCE...WHILE THE BACKGROUND/SYNOPTIC FLOW FROM THE
SOUTH TRIES TO PIN ANY SHOWERS CLOSER TO THE LAKE SUPERIOR SHORE.

CHANCES ARE MAYBE A LITTLE BETTER THE FIRST HALF OF TONIGHT AS AN
ELEVATED WARM FRONT LIFTS THROUGH THE REGION ROUGHLY 06-12Z...WITH
THE SURFACE FRONTAL BOUNDARY SLIDING NORTH TOWARD THE STRAITS BY
SUNRISE. LOW LEVEL JET FORCING IS NOTHING SPECTACULAR...NOR IS ANY
UPPER JET OR DYNAMIC FORCING...AS MUCH OF THAT IS RELEGATED WELL TO
OUR WEST IN ADVANCE OF THE STRONGER UPPER TROUGH. STILL...COULD BE
ENOUGH ACCELERATION OF THE LOW LEVEL JET UP THE SPINE OF LAKE
MICHIGAN TO HELP FIRE OFF SOME ADDITIONAL SHOWERS ACROSS MAINLY THE
TIP OF THE MITT AND EASTERN U.P. THROUGH 06Z. AN EVEN BETTER CHANCE
SHOULD ARRIVE FOR THOSE AREAS AND PROBABLY NORTHWEST LOWER TOO AFTER
06Z AS A PRONOUNCED THETA-E RIDGE FOLDS OVER INTO THE AREA...WITH
MUCAPE VALUES ON THE SOUTHERN FRINGE OF THE ELEVATED WARM FRONT
RISING TO AROUND 700 J/KG...SUGGESTING A THUNDER THREAT. A MILD
NIGHT EXPECTED...WITH LOWS ONLY IN THE 50S NORTH TO 60S ACROSS MUCH
OF NORTHERN LOWER...SOUTH OF THE WARM FRONT. IN FACT...COULD SEE A
FEW SPOTS CLOSER TO LAKE MICHIGAN HOLD NOT FAR FROM 70 THROUGH MUCH
OF THE NIGHT...AS IS TYPICAL IN THESE SETUPS.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 310 AM EDT SUN MAY 19 2013

MONDAY THRU WEDNESDAY...PRECIP CHANCES WILL CONTINUE TO INCREASE
FROM WEST TO EAST MONDAY MORNING AS THE WARM FRONT SAGS SOUTHWARD
INTO NRN LWR MICHIGAN. DEVELOPING LOW PRESSURE IN THE PLAINS WILL
BEGIN TO TAP INTO GULF MOISTURE...ADVECTING IT NORTHWARD THRU THE
LOWER AND MID MISSISSIPPI VALLEY AND INTO THE WRN GREAT LAKES. AS
THIS DEEPER MOISTURE BEGINS TO INTERACT WITH THE WARM FRONT AND A
SERIES OF SHORT WAVES RIDING NE THRU MICHIGAN AHEAD OF THE DEEPENING
UPPER LOWER...SHOWER AND THUNDERSTORM ACTIVITY WILL INCREASE MONDAY
MORNING...WITH LIKELY POPS EXPECTED THRU WEDNESDAY NIGHT. SURFACE
AND CLOSED UPPER LOW BECOME VERTICALLY STACKED...THUS MAKING VERY
SLOW EASTWARD PROGRESS OVER THIS TIME PERIOD...AND THEREFORE KEEPING
OUR WEATHER UNSETTLED THRU MID WEEK. WARM TEMPS WILL HOLD OVER THE
REGION ON MONDAY BEFORE THE WARM FRONT DROPS SOUTH OF OUR CWA ON
TUESDAY AND WEDNESDAY. HIGH TEMPS ON MONDAY WILL RANGE FROM THE MID
TO UPPER 60S ACROSS ERN UPR MICHIGAN NORTH OF THE WARM FRONT TO THE
MID 70S TO LOWER 80S SOUTH OF THE WARM FRONT. HIGH TEMPS WILL ONLY
REACH INTO THE 60S TO NEAR 70 BOTH TUESDAY AND WEDNESDAY AS THE WARM
FRONT CONTINUES TO DROP SOUTH OF OUR CWA.

WEDNESDAY NIGHT THRU SATURDAY...SURFACE AND UPPER LOW CENTERS WILL
SLOWLY SLIDE THRU LWR MICHIGAN WEDNESDAY NIGHT...EXITING EAST TOWARD
NEW ENGLAND THURSDAY. THE THREAT OF THUNDER WILL END WEDNESDAY NIGHT
AS THE SURFACE LOW CENTER SLIDES JUST SOUTH OF OUR CWA. SOME SHOWERS
WILL LINGER ACROSS OUR CWA WEDNESDAY NIGHT AND THURSDAY...BUT SHOULD
COME TO AN END BY THURSDAY NIGHT AS COLDER AND DRIER AIR FILTER INTO
THE REGION BEHIND THE DEPARTING LOW. CORE OF THE COLD AIR WILL
REMAIN WELL NORTH OF MICHIGAN...BUT LIMITED CAA WILL DROP HIGH TEMPS
INTO THE UPPER 50S AND LOWER 60S FOR BOTH THURSDAY AND FRIDAY. NEXT
WEEKEND STILL LOOKS DRY WITH COOLER THAN NORMAL TEMPS AS THE SURFACE
HIGH AND BROAD UPPER LEVEL TROUGHING BOTH REMAIN LOCKED OVER THE
GREAT LAKES.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 650 AM EDT SUN MAY 19 2013

VFR CONDITIONS WILL CONTINUE AT ALL NRN LWR MICHIGAN TAF SITES
THRU MONDAY MORNING. CHANCES OF SHOWERS AND STORMS WILL INCREASE
OVERNIGHT AS A WARM FRONT SAGS SOUTH INTO NRN LWR MICHIGAN AND THE
FIRST IN A SERIES OF SHORT WAVES ENTERS MICHIGAN AHEAD OF LOW
PRESSURE DEVELOPING IN THE PLAINS. WILL HANDLE WITH VCSH FOR NOW
AND BETTER DEFINE TIMING OF PRECIP AS THE EVENT DRAWS CLOSER.
LIGHT SYNOPTIC FLOW WILL ALLOW FOR LAKE BREEZE DEVELOPMENT THIS
AFTERNOON.

&&

.MARINE...
ISSUED AT 310 AM EDT SUN MAY 19 2013

A WEAK GRADIENT WILL CONTINUE TO PROVIDE LIGHT WINDS ACROSS THE
WATERS TODAY INTO TONIGHT...BUT WITH EASTERLY FLOW GRADUALLY
STRENGTHENING LATE TONIGHT THROUGH MIDWEEK...NORTH OF A WARM FRONT
STALLING NEARBY. SMALL CRAFT ADVISORIES MAY EVENTUALLY BE
NEEDED...ESPECIALLY LATER MONDAY THROUGH WEDNESDAY...AND
PARTICULARLY IN AND AROUND THE STRAITS WHERE EASTERLY FLOW WILL BE
CHANNELED. HIGH PRESSURE IS EXPECTED TO SLOWLY WORK BACK INTO THE
REGION LATE IN THE WORK WEEK AND TOWARD NEXT WEEKEND...WITH A RETURN
TO LIGHT WINDS.


&&

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

&&

$$

UPDATE...MR
SYNOPSIS...MLR
SHORT TERM...LAWRENCE
LONG TERM...MLR
AVIATION...MR
MARINE...LAWRENCE