000
FXUS63 KAPX 151609
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1209 PM EDT SAT JUN 15 2013

.SYNOPSIS...
ISSUED AT 250 AM EDT SAT JUN 15 2013

CLOUDS WILL INCREASE TODAY AS A SERIES OF UPPER LEVEL DISTURBANCES
BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO NORTHERN MICHIGAN
BEGINNING THIS AFTERNOON AND CONTINUING THROUGH THE WEEKEND AND INTO
EARLY NEXT WORK WEEK.

&&

.UPDATE...
ISSUED AT 1209 PM EDT SAT JUN 15 2013

14Z SURFACE/COMPOSITE ANALYSIS SHOWS 1021MB HIGH CENTERED OVER WEST
VIRGINIA RIDGING NORTHWESTWARD ACROSS LAKE HURON/FAR EASTERN LAKE
SUPERIOR...COLD/OCCLUDED FRONT RUNS FROM NORTHWEST ONTARIO SOUTHWARD
INTO THE UPPER MIDWEST/CENTRAL PLAINS.  COUPLE WARM FRONTAL
STRUCTURES EAST OF THE FRONT...ONE EMANATES FROM A FRONTAL WAVE NEAR
MSP AND EXTENDS INTO WISCONSIN...THE OTHER CUTS ACROSS CENTRAL/
SOUTHEAST IOWA.  PAIR OF UPPER LOWS TO THE NORTHWEST AND NORTHEAST
OF THE GREAT LAKES...WEAK SHORT WAVE RIDGING IN BETWEEN ACROSS
ILLINOIS/WISCONSIN.  WATER VAPOR IMAGERY SHOWS ANOTHER SHORT WAVE
CROSSING THE CENTRAL PLAINS WITH A SMALL MCS IN TOW...MCV MOVING
ACROSS NORTHERN ILLINOIS AND A SMALL SCALE CIRCULATION SHOWING UP ON
RADAR CROSSING NORTHERN LAKE MICHIGAN.  THIS LATTER FEATURE IS
PUSHING AN AREA OF LIGHT RAIN SHOWERS AND SPRINKLES TOWARD FAR
NORTHWEST LOWER MICHIGAN AS OF LATE MORNING.  FARTHER UPSTREAM
SCATTERED SHOWERS/THUNDERSTORMS OCCURRING ACROSS WESTERN/CENTRAL
UPPER AND NORTHEAST WISCONSIN WITHIN AREA OF LOW LEVEL WARM
ADVECTION AND AHEAD OF AN 850MB TROUGH AXIS.  LOW LEVELS ARE DRIER
ACROSS NORTHERN MICHIGAN PER 12Z APX SOUNDING...BUT AXIS OF DEEPER
MOISTURE EXISTS ACROSS WESTERN UPPER/WISCONSIN WHERE PRECIPITABLE
WATER VALUES AROUND 1.25 INCH.  PARCELS LIFTED FROM 850MB OFF MPX
SOUNDING YIELDS 2130J/KG CAPE.

WILL CONTINUE WITH THE IDEA OF SPOTTY SHOWERS/SPRINKLES ACROSS
NORTHERN LOWER THIS AFTERNOON WITH PASSAGE OF SMALL VORTICITY CENTER
ACROSS THE TIP OF THE MITT COUNTIES...AND ADDITIONAL SCATTERED
ACTIVITY OCCURRING BEHIND IT.  POSSIBLE THAT EASTERN UPPER STAYS
MOSTLY DRY THIS AFTERNOON AND WILL TREND THE FORECAST IN THIS
DIRECTION.

UPDATE ISSUED AT 1009 AM EDT SAT JUN 15 2013

13Z MESOANALYSIS SHOWS A NORTHWEST-SOUTHEAST ORIENTED RIDGE AXIS
RUNNING FROM THE EASTERN SHORE OF LAKE SUPERIOR...ACROSS LAKE HURON
AND DOWN INTO EASTERN OHIO.  BROKEN-OVERCAST MID CLOUD DECK HAS
OVERSPREAD NORTHERN MICHIGAN...NOT MUCH ON RADAR OVER THE IMMEDIATE
AREA WITH SOME VERY LIGHT RAIN SHOWERS MOVING ACROSS CENTRAL UPPER
MICHIGAN THOUGH RADAR LOOPS SHOW THIS DRIVEN BY A COMPACT MESOSCALE
VORTICITY CENTER.  12Z APX SOUNDING SHOWS SATURATION IN THE 650-
550MB LAYER BUT IS QUITE DRY BELOW (36C DEW POINT DEPRESSION AT
850MB).

IMMEDIATE NOWCAST CHANGES TO FORECAST WILL BE TO INCREASE CLOUD
COVER... AND ADD IN SOME VERY LIGHT RAIN SHOWERS (OR MOSTLY
SPRINKLES) TO MUCH OF EASTERN UPPER AND NORTH OF A TVC-OSC LINE IN
NORTHWEST LOWER (MOSTLY AFTER 16Z).

UPDATE ISSUED AT 700 AM EDT SAT JUN 15 2013

WIDELY SCATTERED MID LEVEL RETURNS CONTINUE TO DRIFT SOUTH OF OUR
CWA EARLY THIS MORNING PER LATEST KAPX 88D BASE REF LOOP. ALL CIGS
REMAIN ABOVE 10 KFT SO FAR TODAY...BUT DO EXPECTED SOME LOW CLOUD
DEVELOPMENT AS WE HEAD INTO THIS AFTERNOON IN RESPONSE TO
GRADUALLY INCREASING LOW LEVEL MOISTURE AHEAD OF WEAK LOW PRESSURE
TRACKING TOWARD MICHIGAN. PRECIP CHANCES WILL GRADUALLY INCREASE
TOWARD AFTERNOON AS WELL...BUT ANY SHOWER OR THUNDERSTORM ACTIVITY
WILL REMAIN SCATTERED...WITH BETTER CHANCES AND HEAVIER PRECIP
REMAINING SOUTH OF OUR CWA. HAVE MADE SOME ADJUSTMENTS TO CLOUD
COVER BASED ON LATEST IR SATELLITE LOOP. OTHERWISE...CURRENT
FORECAST HIGHLIGHTS INCREASING SMALL CHANCES OF SHOWERS/STORMS
THIS AFTERNOON...WHICH IS STILL ON TARGET.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 250 AM EDT SAT JUN 15 2013

FIRST OF ALL...HATS OFF TO OLD MOTHER NATURE...DELIVERING ONE OF THE
FINER SUMMER DAYS YOU WILL SEE AROUND THESE PARTS YESTERDAY. DRY
AIRMASS RESPONSIBLE FOR SUCH FANTASTIC WEATHER STILL FIRMLY IN
CONTROL AT THIS EARLY HOUR...WITH EXPANSIVE SURFACE HIGH PRESSURE
EXTENDING FROM THE NORTHERN LAKES RIGHT DOWN INTO THE SOUTHEASTERN
STATES. 00Z RAOB PWAT ANALYSIS CONFIRMS SUCH...WITH CP AIRMASS
BRINGING SUB ONE INCH PWAT VALUES ACROSS THIS SAME REGION (RATHER
IMPRESSIVE FOR THIS TIME OF YEAR). UNFORTUNATELY...ONE DOES NOT HAVE
TO VENTURE TOO FAR WEST FOR SOME INCLEMENT WEATHER. BACKSIDE RETURN
FLOW ALREADY AMPING UP ACROSS THE WESTERN LAKES...WITH REAL-TIME OBS
AND HIGH RES RUC ANALYSIS SHOWING ELEVATED MOISTURE PLUME ALREADY
PUNCHING THROUGH WISCONSIN AND WESTERN UPPER MICHIGAN. LEADING
MOISTURE CONVERGENCE AXIS AND SUBTLE WAVE PIVOTING THROUGH BROADER
UPSTREAM RIDGING MANAGED TO KICK OFF SOME EVENING SHOWERS AND STORMS
TO OUR NORTHWEST...ALTHOUGH THESE HAVE LARGELY DIED OUT AS THEY
APPROACH OVERHEAD DEEP LAYER DRY WEDGE. THEME OF THIS SUMMER
CONTINUES...WITH THE MOST PROMINENT AREA OF SHOWERS AND STORMS
REMAINING SAFELY TO OUR SOUTHWEST WHERE NOCTURNALLY CHARGED LOW
LEVEL JET FORCED MASS CONVERGENCE AND DEEP INSTABILITY ARE BETTER
JUXTAPOSED. RADAR AND SATELLITE TRENDS BOTH SUGGEST THIS SHOULD
REMAIN THE CASE RIGHT THROUGH THE EARLY MORNING HOURS...LEAVING
MOSTLY DRY CONDITIONS ACROSS OUR AREA THROUGH AT LEAST THE FIRST
HALF OF THE MORNING. SHORT TERM FORECAST CONCERNS CENTER ON POSSIBLE
ADDITIONAL SHOWER AND STORM DEVELOPMENT TODAY AND TONIGHT.

GOING TO BE AWFULLY HARD TO BEAT YESTERDAY...AND......WE WON`T.
THAT SAID...UPSTREAM TRENDS AND PATTERN RECOGNITION SUPPORTS A
NOT-TO-SHABBY START TO THE WEEKEND. REMAIN LARGELY UNENTHUSED WITH
RAIN CHANCES TODAY...DESPITE STAGE RIGHT DEPARTURE OF CURRENT
SURFACE HIGH. UPSTREAM MID LEVEL RIDGING REPLACES ITS SURFACE
LIKENESS...ALTHOUGH DEAMPLIFYING AS IT DOES SO WITH ENERGY CUTTING
ACROSS SOUTHERN CANADA. UPPER LEVEL FORCING ARRIVES LATE VIA RER
UPPER JET DYNAMICS...MOST OF WHICH HOLDS OFF UNTIL THE OVERNIGHT
HOURS. PER THE USUAL...GUIDANCE JUST SEEMS MUCH TOO AGGRESSIVE
DRIVING LOW LEVEL MOISTURE THIS FAR NORTH...ESPECIALLY GIVEN
ANTECEDENT DRY CONDITIONS AND PROPENSITY FOR MOISTURE STEALING
CONVECTION TO CONTINUE TO FIRE WELL TO OUR SOUTHWEST. MODIFYING
MODEL SUGGESTED SOUNDINGS FOR SUCH SHOWS SIGNIFICANT MID LEVEL CAP
UNTIL VERY LATE...AND LITTLE...IF ANY ML CAPE DEVELOPMENT. CORE OF
MORE IMPRESSIVE MID LEVEL LAPSE RATES REMAINS JUST UPSTREAM ACROSS
WISCONSIN. THETA-E RIDGING DOES ADVANCE EAST WITH TIME....CROSSING
OUR AREA LATE MORNING THROUGH THE AFTERNOON. EVEN THIS...HOWEVER...
WILL BE LOSING DEFINITION WITH TIME. NO DOUBT CLOUDS WILL BE ON THE
INCREASE AS UPSTREAM MID LEVEL MOISTURE PLUME ADVANCES EAST...BUT
GIVEN ALL THE ABOVE...THE PROSPECTS FOR ANY MEANINGFUL RAINS ARE
MUCH LESS THAN IDEAL. SUPPOSE A SPRINKLE/VERY LIGHT SHOWER IS
PLAUSIBLE ALONG THETA-E GRADIENT OR FROM WHAT`S EVER LEFT OF
UPSTREAM ACTIVITY. TEMPTED TO PULL POPS ALTOGETHER...BUT GIVEN SOME
LINGERING UNCERTAINTY...WILL JUST SIMPLY MAINTAIN INHERITED LOW
CHANCE MENTION. DESPITE CLOUDS...THERMAL PROFILES SUPPORT A RATHER
MILD DAY...WITH HIGHS WELL INTO THE 70S ACROSS MOST AREAS. LIGHT
PRESSURE GRADIENT SUPPORTS LATE MORNING AND AFTERNOON LAKE BREEZE
DEVELOPMENT...KEEPING SHORELINE AREAS A FEW DEGREES COOLER.

THINGS TRY TO CONGEAL TO BRING BETTER RAIN CHANCES TONIGHT...WITH
SOMEWHAT DEEPER LOW LEVEL MOISTURE OVERTOPPED BY UPPER JET DYNAMICS.
NOTHING OVERLY IMPRESSIVE THROUGH THE MID LEVELS...WITH PERHAPS A
CONVECTIVELY AUGMENTED VORT LOBE/SUBTLE WAVE RACING EAST ACROSS THE
SOUTHERN THIRD OF THE AREA. PATTERN RECOGNITION CONTINUES TO SUPPORT
SOUTHERN LAKES/NORTHERN OHIO VALLEY MCS DEVELOPMENT ON NOSE OF
STRONGER LOW LEVEL JET. SOME GUIDANCE SEEMS OVERLY AGGRESSIVE
DRIVING CONVECTIVE DEVELOPMENT NORTH...ESPECIALLY THE 00Z GFS AND
12Z ECMWF. DEEP LAYER FLOW SIMPLY DOES NOT BACK ENOUGH TO SUPPORT
THESE NORTH BASED TRENDS. CONVECTIVE EVOLUTION TODAY WILL HAVE
PLENTY TO SAY ON OVERALL MASS FIELDS...BUT LARGE SCALE PATTERN FULLY
SUPPORTS A MORE SOUTH BASED PASSAGE TO ANY MCS TONIGHT...WITH JUST
SOME LIGHTER ACTIVITY THIS FAR NORTH. WILL TREND POPS AS SUCH...BUT
STILL LEAVE PLENTY OF OPPORTUNITY FOR FUTURE ADJUSTMENTS BASED ON
THIS AFTERNOONS UPSTREAM TRENDS. A MILD NIGHT...WITH LOWS IN THE 50S
AND LOWER 60S.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 250 AM EDT SAT JUN 15 2013

SUNDAY AND MONDAY...A WEAK AREA OF LOW PRESSURE WILL SLIDE EAST THRU
MICHIGAN EARLY SUNDAY MORNING. THIS LOW WILL GRADUALLY MERGE WITH
ANOTHER NRN STREAM LOW DROPPING SE INTO MICHIGAN SUNDAY AFTERNOON
AND EVENING. A COLD FRONT ASSOCIATED WITH THE SECOND LOW PRESSURE
SYSTEM WILL DROP INTO NRN MICHIGAN SUNDAY NIGHT...AND WILL THEN
SWEEP THRU LWR MICHIGAN ON MONDAY. LATEST NAM APPEARS TO BE TOO FAST
WITH THE PASSAGE OF THIS FRONT CONSIDERING THE FRONT BECOMES
ORIENTED WEST TO EAST ALONG THE UPPER LEVEL FLOW ONCE IT REACHES
UPPER MICHIGAN. ECMWF PROVIDES A SLOWER AND THUS MORE REASONABLE
SOLUTION...AND WILL LEAN IN THIS DIRECTION. CHANCE OF SHOWERS/STORMS
WILL LINGER INTO SUNDAY MORNING FOR MUCH OF OUR CWA AS THE INITIAL
SURFACE LOW EXITS LWR MICHIGAN. DIURNAL INSTABILITY COMBINED WITH
WEAK LAKE BREEZE BOUNDARIES AND LINGERING LOW LEVEL MOISTURE TO
PROVIDE SMALL CHANCES OF SHOWERS AND STORMS FOR ERN UPR AND NE LWR
MICHIGAN SUNDAY AFTERNOON. SECONDARY SURFACE LOW AND ASSOCIATED COLD
FRONT WILL DROP INTO ERN UPR AND FAR NRN LWR MICHIGAN SUNDAY
AFTERNOON/EVENING...PROVIDING ADDITIONAL FOCUS FOR CONVECTIVE
DEVELOPMENT TO PERSIST THRU THE NIGHT ACROSS LOCATIONS ALONG AND
NORTH OF M-32. BY MONDAY...THE SLOW-MOVING COLD FRONT WILL DROP THRU
THE REST OF OUR CWA...RESULTING IN CONTINUED CONVECTIVE DEVELOPMENT
THRU THE DAY. CHANCES OF SHOWERS AND STORMS WILL COME TO AN END THRU
MONDAY NIGHT AS THE COLD FRONT EXITS LWR MICHIGAN.

TUESDAY THRU FRIDAY...STRONG CANADIAN HIGH PRESSURE...SUBSIDENCE AND
DRY AIR WILL BUILD INTO THE GREAT LAKES TUESDAY INTO WEDNESDAY
BEHIND THE DEPARTING COLD FRONT. DRY WEATHER IS EXPECTED THRU THIS
TIME PERIOD...WITH TEMPS SEVERAL DEGREES BELOW NORMAL THANKS TO CAA.
WEAK AREA OF LOW PRESSURE WILL SLOWLY TRACK THRU ONTARIO AND INTO
QUEBEC WEDNESDAY NIGHT THRU FRIDAY...DRAGGING THE SRN END OF A WEAK
FRONT THRU NRN MICHIGAN. BOTH MOISTURE AND LIFT WILL BE LIMITED WITH
THIS WEAK FEATURE...BUT WILL INTRODUCE SMALL PRECIP CHANCES INTO THE
FORECAST FOR THIS TIMEFRAME AS THIS FRONT PASSES THRU THE REGION.
TEMPS WILL REBOUND TO NEAR NORMAL IN WEAK WAA AHEAD OF THIS FRONT.
INITIAL LOOK FOR NEXT WEEKEND SUGGESTS MAINLY DRY WEATHER WITH NEAR
NORMAL TEMPS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 700 AM EDT SAT JUN 15 2013

OVERALL CONDITIONS WILL REMAIN VFR THRU THE 24 HR TAF FORECAST
PERIOD. A THICK DECK OF MID CLOUDS WILL REMAIN OVERHEAD...AS
SCT/BKN LOW CLOUDS AT AROUND 5-6 KFT DEVELOPS TODAY AND TONIGHT.
CHANCES OF SHOWERS AND POSSIBLY A THUNDERSTORM WILL GRADUALLY
INCREASE AS WE HEAD INTO THIS AFTERNOON AND TONIGHT ALONG AND
AHEAD OF WEAK LOW PRESSURE TRACKING EAST THRU MICHIGAN. LIGHT
WINDS THIS MORNING WILL ONLY INCREASE TO LESS THAN 10 KTS FROM THE
SW BY THIS AFTERNOON...WITH SOME LAKE BREEZE DEVELOPMENT EXPECTED
ALONG THE LAKESHORES.


&&

.MARINE...
ISSUED AT 250 AM EDT SAT JUN 15 2013

LIGHT WINDS CONTINUE...WITH LOCAL LAKE BREEZE DEVELOPMENT
THIS AFTERNOON...ESPECIALLY OFF LAKE HURON. WEAK SURFACE TROUGH
PASSES THROUGH THE REGION LATE TONIGHT INTO EARLY SUNDAY...VEERING
SOUTHWEST FLOW TO WESTERLY. MARINE FOG EXPECTED TO DEVELOP LATER
TONIGHT INTO SUNDAY AS LOW LEVEL MOISTURE ADVECTION STRENGTHENS.
SHOWERS AND STORMS POSSIBLE TONIGHT...ALTHOUGH STRONGEST ACTIVITY
EXPECTED TO REMAIN ACROSS THE SOUTHERN LAKES. EARLY INDICATIONS ARE
FOR MAINLY LIGHT WINDS TO CONTINUE RIGHT THROUGH MUCH OF NEXT WORK
WEEK.


&&

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

&&

$$

UPDATE...JPB
SYNOPSIS...MLR
SHORT TERM...MSB
LONG TERM...MLR
AVIATION...MLR
MARINE...MSB