404 
FXUS63 KAPX 151805
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
205 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 158 PM EDT SAT JUN 15 2013

SCATTERED RADAR RETURNS OVER NORTHWEST LOWER...SOME SPITS OF RAIN
REPORTED AT PLN/FKS/TVC. THINGS SEEM TO BE EVOLVING AS
ANTICIPATED... DRY FORECAST OVER EASTERN UPPER STILL LOOKS FINE
AND MAY EVEN SEE SOME PEEKS OF SUN LATER. EXPECT THAT BEST CHANCE
FOR RAINFALL WILL ARRIVE DURING THE EVENING HOURS AS SHORT WAVE
TROUGH MOVING INTO NORTHWEST IOWA SPINS TOWARD LOWER MICHIGAN.
EXPECT ADDITIONAL CONVECTIVE DEVELOPMENT AHEAD OF THIS WAVE OVER
THE NEXT SEVERAL HOURS THAT EVENTUALLY GETS PUSHED INTO AT LEAST
LOWER MICHIGAN BY THIS EVENING.

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 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 158 PM EDT SAT JUN 15 2013

VFR CONDITIONS THROUGH THE AFTERNOON...SOME MVFR VISIBLITIES WITH
RAIN SHOWERS TONIGHT AND A PERIOD OF MVFR/IFR CEILINGS OVERNIGHT
THAT WILL MIX OUT SUNDAY MORNING.

&&

.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
MARINE...MSB