610 
FXUS63 KAPX 132331
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
731 PM EDT SAT JUL 13 2013

.SYNOPSIS...
ISSUED AT 345 PM EDT SAT JUL 13 2013

A DOMINATING AREA OF HIGH PRESSURE OVER THE EASTERN THIRD OF THE 
COUNTRY...WILL REMAIN CENTERED ALONG THE ATLANTIC SEABOARD FOR THE 
NEXT SEVERAL DAYS. THIS PATTERN WILL GENERATE EXTREMELY WARM 
TEMPERATURES WITH INCREASING HUMIDITY LEVELS ACROSS THE GREAT LAKES 
THROUGH THE WEEKEND.

TEMPERATURES ARE ACTUALLY EXPECTED TO WARM INTO THE LOWER 90S TO 
START THE UPCOMING WORK WEEK. CHANCES OF SHOWERS AND STORMS WILL 
ENTER OUR WEATHER PICTURE BY MIDWEEK...AS A WEAK COOL FRONT SWEEPS 
THROUGH THE GREAT LAKES.

&&

.UPDATE...
ISSUED AT 730 PM EDT SAT JUL 13 2013

FLAT CU FIELD DIMINISHING ON SCHEDULE. NO CHANGES OF SUBSTANCE
MADE TO THE FORECAST FOR NOW.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 345 PM EDT SAT JUL 13 2013

AFTERNOON SURFACE ANALYSIS SHOWS HIGH PRESSURE EXTENDING FROM NEW 
ENGLAND/SOUTHERN QUEBEC WESTWARD INTO THE UPPER GREAT LAKES...COLD 
FRONT STRETCHES FROM HUDSON BAY SOUTHWEST INTO NORTH DAKOTA/ 
MONTANA.  UPPER RIDGE AXIS CROSSES THE GREAT LAKES AS WELL... 
"BRIDGING" CLOSED ANTICYCLONES OVER THE CENTRAL PLAINS AND OFF THE 
LONG ISLAND COAST WHILE AN UPPER LOW RETROGRADES WEST ALONG THE OHIO 
RIVER.  LATTER UPPER HIGH FORECAST TO BUILD WEST AND ENCOMPASS LOWER 
MICHIGAN BY SUNDAY AFTERNOON...WHILE SURFACE RIDGING HANGS ON AS 
WELL.  THE RESULT IS MINIMAL FORECAST CONCERNS OUTSIDE OF HIGH 
TEMPERATURES SUNDAY AFTERNOON.

TONIGHT/SUNDAY: WEATHER...SCATTERED CUMULUS ACROSS INTERIOR NORTHERN 
LOWER AT MID AFTERNOON WILL DISSIPATE WITH LOSS OF HEATING...THICKER 
BAND OF CLOUDS ACROSS WESTERN UPPER AND MUCH OF WESTERN/CENTRAL LAKE 
SUPERIOR SHOULD GET NUDGED NORTHWARD OVERNIGHT AS MID LEVEL WINDS 
BACK WITH RISING HEIGHTS AS ATLANTIC UPPER RIDGE BUILDS WESTWARD.  
PLENTY OF SUN FOR SUNDAY.  

WINDS...BECOMING LIGHT SOUTHERLY/VARIABLE THIS EVENING WITH 
DECOUPLING (ESPECIALLY ACROSS NORTHERN LOWER)...GENERALLY SOUTH/ 
SOUTHWEST WINDS FOR SUNDAY UNDER 10 MPH NORTHERN LOWER AND 5-15 MPH 
EASTERN UPPER...LAKE BREEZES WILL TURN WINDS OFF THE WATER AROUND 
THE NORTHWEST LOWER SHORELINE.  

TEMPERATURES...SEASONABLE 50S FOR LOWS TONIGHT...SHOULD BE ABLE TO 
TACK ON A COUPLE DEGREES TO TODAY'S HIGHS FOR SUNDAY...SO MORE 
WIDESPREAD 80S EXPECTED AWAY FROM THE LAKES.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 PM EDT SAT JUL 13 2013

LOOKS TO BE NO STOPPING NOW WELL ADVERTISED DEVELOPMENT OF A MINI 
NORTHERN MICHIGAN HEAT WAVE HEADING INTO THE UPCOMING WORK WEEK. 
PATTERN RECOGNITION FULLY SUPPORTS SUCH...WITH CURRENT WESTERN 
ATLANTIC RIDGING RETROGRADING AND STRENGTHEN TO A 595+ HEIGHT 
ANTICYCLONE OVER THE NORTHERN OHIO VALLEY MONDAY THROUGH WEDNESDAY. 
OVERHEAD LOWER AND MIDDLE 590 HEIGHTS NOTHING TO SNEEZE AT...WITH 
MULTI-DAY SUSTAINED W-SW OFF THE DECK FLOW TAPPING INTO AT LEAST 
SOME OF THE CENTRAL PLAINS HEAT DOME. RECORD SETTING HEAT IT APPEARS 
NOT TO BE...BUT WITH H85 TEMPERATURES PROGGED TO REACH THE UPPER 
TEENS...LOWER 90S APPEAR EASILY ATTAINABLE FOR AT LEAST PARTS OF THE 
AREA EACH AFTERNOON MONDAY THROUGH WEDNESDAY. WHILE DON'T SEE A 
DIRECT TAP TO WESTERN GULF OF MEXICO MOISTURE...GRADUAL MOISTURE 
POOLING AND NEAR PEAK EVAPOTRANSPIRATION WILL HELP DEW POINTS SPIKE 
WELL INTO THE 60S (IF NOT LOWER 70S). THIS SETS THE STAGE FOR 
APPARENT TEMPERATURES TO FEEL SEVERAL DEGREES HOTTER THAN ACTUAL 
HIGHS...MAKING FOR SOME VERY UNCOMFORTABLE CONDITIONS. RATHER 
SIGNIFICANT CHANGES IN THE PATTERN EXPECTED TOWARDS THE END OF 
WEEK/INTO THE START OF NEXT WEEKEND... WITH TROUGHING DIGGING BACK 
ACROSS THE LAKES...DRIVING A RATHER SIGNIFICANT COLD FRONT SOUTH 
ACROSS THE REGION. THIS WILL BRING OUR BEST BET FOR SOME MUCH NEEDED 
RAINFALL AS MID LEVEL HEIGHTS LOWER...ALONG WITH A RETURN TO MUCH 
MORE TOLERABLE TEMPERATURES. FORECAST CONCERNS THROUGH THE EXTENDED 
CENTER ON SHEDDING A TOUCH MORE INSIGHT TO ALL THE ABOVE.

INCREASINGLY HOT...HUMID...AND MOSTLY DRY ABOUT SUMS UP THE WEATHER 
HEADING INTO MID WEEK. DEEP LAYER HIGH PRESSURE REMAINS CENTERED 
ACROSS THE REGION...FORCING SHOWER/STORM PRODUCING BAROCLINIC AXIS 
WELL TO OUR NORTH AND WEST. H85 TEMPERATURES BEGIN THE TREND 
UPWARD...MAXING OUT IN THE UPPER TEENS BY TUESDAY AND WEDNESDAY. SEE 
LITTLE REASON NOT TO MIX OUT AT LEAST THROUGH THIS LAYER...WHICH 
SUPPORTS HIGH TEMPERATURES NEAR 90 FOR SOME MONDAY...AND UP INTO THE 
LOWER 90S TUESDAY AND WEDNESDAY AFTERNOONS. PER THE USUAL...WARMEST 
READINGS WILL BE FOUND ACROSS THE INTERIOR OF NORTHERN LOWER...WITH 
LAKE MODIFICATION HELPING KEEP NEARSHORE AREAS AND LOCATION NORTH OF 
THE BIG BRIDGE A TOUCH LESS OPPRESSIVE. HEAT INDICES BEGIN TO SPIKE... 
ESPECIALLY TUESDAY AND WEDNESDAY AFTERNOON WHEN DEW POINTS REACH 
INTO THE UPPER 60S AND LOWER 70S. MUGGIEST WEATHER EXPECTED ON THE 
SOUTH SIDE OF THE SUNRISE SIDE CLOSER TO MAX AREA OF 
EVAPOTRANSPIRATION FROM LOWER MICHIGAN CORN BELT. HERE...WOULD EXPECT 
APPARENT TEMPERATURES TO AT LEAST APPROACH HEAT ADVISORY CRITERIA 
(HEAT INDICES OF AT LEAST A 100 FOR A PERIOD OF 3 HOURS OR MORE). 
NOT MUCH BETTER ELSEWHERE...WITH WIDESPREAD LOWER AND MIDDLE 90 
DEGREE HEAT INDICES ACROSS INTERIOR NORTHERN LOWER MICHIGAN. AS 
MENTIONED...AND UNFORTUNATELY...THIS SHOULD ALSO MAINLY BE A DRY 
PATTERN WITH SUCH HIGH MID LEVEL HEIGHTS AND LACK OF ANY APPRECIABLE 
TRIGGER. MODEL DERIVED SOUNDINGS STARTING TO SHOW SOME RATHER 
IMPRESSIVE ML CAPE DEVELOPMENT DURING PEAK AFTERNOON HEATING...WITH 
VALUES AOA 1.5 J/KG FOR SOME. THIS IS LIKELY A TOUCH OVERDONE...WITH 
GUIDANCE A TOUCH TOO AGGRESSIVE DRIVING SURFACE DEWPOINTS UPWARD. 
EITHER WAY...APPEARS TO BE AT LEAST SOME FUEL FOR LAKE INDUCED 
BOUNDARIES TO KICK OFF SOME ISOLATED MOIST CONVECTION. GIVEN CURRENT 
DRY PATTERN AND INHERENT MESOSCALE FORECAST DIFFICULTIES...PREFER TO 
LEAVE THIS POSSIBILITY OUT OF THE FORECAST. ONE EXCEPTION... 
HOWEVER...WILL BE ACROSS EASTERN UPPER WEDNESDAY AFTERNOON...WHERE 
LOWERING HEIGHTS LOOK TO HELP THE CONVECTIVE CAUSE.

INCREASING SUPPORT FOR A PATTERN REALIGNMENT HEADING INTO WEDNESDAY 
NIGHT AND BEYOND...WITH REESTABLISHMENT OF INTERMOUNTAIN WEST 
RIDGING AND SUBSEQUENT ARRIVAL OF LOWERING HEIGHTS ACROSS THE GREAT 
LAKES. TIMING STILL SUBJECT TO CHANGE...OF COURSE...BUT PERUSAL OF 
AVAILABLE MID RANGE GUIDANCE SUGGESTS COLD FRONTAL PASSAGE WEDNESDAY 
NIGHT (GO FIGURE...ANOTHER OVERNIGHT FRONTAL PASSAGE :)). FORCING 
ALONG THIS FRONT NOT OVERLY IMPRESSIVE...ALTHOUGH THERE IS SOME 
SEMBLANCE OF ATTENDANT DIVERGENCE POCKET TIED TO UPPER JET RER QUAD. 
UNFAVORABLE TIMING ONLY ADDING TO THE UNCERTAINTY IN RAIN 
COVERAGE...SO A SIMPLE CHANCE WORDING WILL SUFFICE FOR NOW. ADDITION 
HARD TO TIME WAVES EXPECTED TO PINWHEEL THROUGH THE REGION INTO THE 
START OF NEXT WEEKEND. MODEL BLEND APPROACH JUST TOO AGGRESSIVE WITH 
RAIN CHANCES...HOWEVER...ESPECIALLY GIVEN TIMING AND MOISTURE 
AVAILABILITY UNCERTAINTIES. AS IS OFTEN THE CASE DURING THE 
SUMMER...FORECAST WILL SEEM MUCH WETTER THAN IT ACTUALLY WILL 
BE...WITH EXTENDED DRY PERIODS MORE THAN EXPECTED DURING THIS 
PERIOD. ONE THING APPEARS INCREASINGLY CERTAIN...AND THAT IS A TREND 
TOWARDS MUCH MORE TOLERABLE TEMPERATURES. TEMPERATURES LOOK TO COOL 
OFF HEADING INTO THE WEEKEND...WITH 80+ DEGREE HIGHS THURSDAY GIVEN 
WAY TO READINGS BACK DOWN INTO PERHAPS THE LOWER AND MIDDLE 70S BY 
SATURDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 730 PM EDT SAT JUL 13 2013

VFR...OUTSIDE OF SOME GROUND FOG AT MBL LATE TONIGHT.

VERY LITTLE IS CHANGING ACROSS THE NORTHERN LAKES...AS HIGH
PRESSURE NOSES IN FROM THE EAST. LIGHT SOUTHERLY WINDS AT THE LOW
LEVELS ARE VERY SLOWLY BRINGING IN WARMER AND MORE HUMID AIR. SOME
THIN GROUND FOG COULD FORM AT MBL TONIGHT...ONLY HAVE MVFR VSBYS
IN A TEMPO GROUP FOR NOW. A FEW CUMULUS ARE EXPECTED AGAIN ON
SUNDAY. 

LIGHT WINDS TONIGHT. A LIGHT SOUTH BREEZE EARLY SUNDAY WILL GIVE
WAY TO LAKE BREEZES LATER IN THE DAY.

&&

.MARINE...
ISSUED AT 345 PM EDT SAT JUL 13 2013

LAKE BREEZE CIRCULATIONS WILL DIMINISH THIS EVENING BUT WILL RAMP UP 
AGAIN FOR SUNDAY...MAINLY NOTICEABLE AROUND THE NORTHEAST LOWER 
NEARSHORE ZONES WHERE WINDS WILL TAKE ON AN EASTERLY COMPONENT OFF 
LAKE HURON.  NO HEADLINES EXPECTED THROUGH SUNDAY NIGHT.


&&

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

&&

$$

UPDATE...JZ
SYNOPSIS...KB
SHORT TERM...JB
LONG TERM...MB
AVIATION...JZ
MARINE...JB