Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 290125
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
925 PM EDT TUE JUL 28 2015

.UPDATE...
ISSUED AT 924 PM EDT TUE JUL 28 2015

STRONG SFC AND UPPER LVL RIDGE WHICH HAS BEEN IN PLACE ACROSS THE
GREAT LAKES AND OHIO VALLEY SINCE THE WEEKEND...WILL SLOWLY BEGIN TO
BREAKDOWN AND EXIT EAST TOWARD THE ATLANTIC TONIGHT. THIS WILL ALLOW
A STORM SYSTEM ORGANIZING OVER THE NRN PLAINS TO LIFT TOWARD HUDSON
BAY ON WEDNESDAY. A BOUNDARY ASSOCIATED WITH THIS SYSTEM...WILL PUSH
INTO THE WRN LAKES OVERNIGHT BEFORE QUICKLY EXITING EAST INTO LAKE
HURON WEDNESDAY EVENING. 850/700MB QVECTORS SHOW THE BEST
CONVERGENCE ALONG THE BOUNDARY TO INFLUENCE THE WRN LAKES BETWEEN
09Z WED AND 15Z WED...WITH THE BEST CONCENTRATED FOCUS BTWN 15Z WED
AND 00Z THURSDAY FOR THE ERN LAKES. MODEL SOUNDINGS AND MSTR PROGS
SHOW PLENTY OF MSTR TO AID IN INSTABILITY AND PCPN CHANCES ACROSS
NRN MI WEDNESDAY...AS SFC AND MID LVL DEW PT VALUES INCREASE
SIGNIFICANTLY IN ADVANCE OF THE APPROACHING BOUNDARY. 850MB DEW PTS
INCREASE FROM 11C TO 16C WHILE SFC DEW PTS INCREASE FROM THE UPPER
50S TONIGHT TO THE MID 60S BY 12Z WED.

CURRENT RADAR AND SAT DATA SHOWING BASICALLY JUST PARTLY CLOUDY
SKIES ACROSS MUCH OF THE GREAT LAKES REGION...WHILE CONVECTION FIRES
IN IOWA AND ERN MINN. IOWA STORMS ARE BEING TRIGGERED IN A THETA
RIDGE IN ADVANCE OF THE NRN PLAINS SFC BOUNDARY AND AIDED AND UPPER
JET DYNAMICS. 850/300MB THICKNESS WOULD SUGGEST IOWA PCPN WILL
REMAIN WELL SOUTH OF THE REGION OVERNIGHT.

OVERALL WILL CONTINUE WITH MAINLY DRY CONDS ACROSS NRN MI INTO THE
EARLY OVERNIGHT HOURS...BEFORE MENTIONING A SMALL CHANCE OF
CONVECTION OVER THE WRN LAKES AROUND 09Z TO 12Z AS CONVERGENCE IN
ADVANCE OF NRN PLAINS SYSTEM INCREASES.

&&

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 318 PM EDT TUE JUL 28 2015

IMPACT WEATHER: POSSIBLE THUNDERSTORM NEAR DAYBREAK. NO SEVERE.

SYNOPTIC PATTERN AND OBSERVATIONS:

AFTERNOON ANALYSIS...UPPER LEVEL RIDGING WAS SLIDING EAST WHILE THE
EARLIER SHORTWAVE/MCV CONTINUES TO MARCH INTO INTO THE WESTERN GREAT
LAKES. THIS WAVE IS OUTRUNNING THE BETTER MOISTURE AND INSTABILITY
STILL ACROSS THE MISSISSIPPI VALLEY...AHEAD OF A COLD FRONT. AS A
RESULT...THE EARLIER CONVECTION HAS PRETTY MUCH VANISHED. WE ARE
STILL DEALING WITH SOME CONVECTIVE DEBRIS/CLOUD BLOWOFF...BUT THIS
HASN`T STOPPED TEMPERATURES FROM SOARING INTO THE HOT LOWER 90S FOR
MOST OF THE REGION. LAKE BREEZES HAVE STARTED PRESSING INLAND WITH
FAIRLY SPORADIC CUMULUS GETTING SET TO CONSOLIDATE THEMSELVES INTO
THE CONVERGING LAKE BREEZES...INTERIOR LOCALES/AWAY FROM THE GREAT
LAKES. OUT WEST...COLD FRONT WAS STRETCHED OUT FROM MINNESOTA TO
WESTERN IOWA AND NEBRASKA. NOTHING HAS FIRED YET ON THE FRONT NORTH
OF IOWA...WHERE SUBSIDING AIR RESIDES FROM THE DEPARTING MCV/WAVE.
ACROSS WESTERN IOWA THOUGH...SUBSIDENCE WAS NON-EXISTENT.
ACTUALLY...LATEST SATELLITE SHOWING SOME WEAK VORTICITY MAXIMA
FEEDING THIS AREA WITH A LITTLE BETTER LOW LEVEL CONVERGENCE.
HENCE...ADDITIONAL SHOWERS AND EMBEDDED RUMBLES OF THUNDER HAVE BEEN
ABLE TO REDEVELOP.

TEMPERATURES WERE TOPPING OUT IN THE LOWER 90S FOR MOST FOLKS...BUT
HAVE NOW COOLED OFF A LITTLE NEAR THE LAKESHORES DUE TO LAKE
BREEZES.

SYNOPTIC PATTERN EVOLUTION AND ASSOCIATED WEATHER:

THE COLD FRONT WILL MAKE IT INTO EASTERN WISCONSIN BY
DAYBREAK...WITH A WING OF WARM/MOIST ADVECTION SLIDING INTO LAKE
MICHIGAN. UNLIKE LAST NIGHT WHERE A STRONG LOW LEVEL JET AIDED IN
FIRING OFF A WIDE SWATH OF SHOWERS AND STORMS...THE LLJ TONIGHT WILL
BE MUCH WEAKER AND VERY DIFFICULT TO SEE WHERE IT WILL SET UP. THE
KEY IN FIGURING OUT WHERE/IF STORMS DEVELOP MAY LIE IN THAT LATEST
SATELLITE IMAGERY. THE WEAK VORTICITY/POCKETS OF ENHANCED CLOUDS AND
RESULTING BETTER LOW LEVEL CONVERGENCE WILL LIKELY POKE INTO NRN IL
THROUGH THE NIGHT...POSSIBLY LIFTING INTO SRN WISCONSIN WITH SOME
MINOR ADDITIONAL HEIGHT RISES. COULD SEE A CLUSTER OF SHOWERS AND
WEAK STORMS THERE...EVENTUALLY DRIFT EASTWARD TOWARD THE GTV
BAY/MANISTEE AREA AROUND DAYBREAK. WHATEVER DOES FIRE...IT WILL
UNDERGO THE SAME WEAKENING THROUGH WEDNESDAY MORNING...DECAYING AS
THE LLJ MIXES OUT. THIS WHOLE PROCESS IS SLOWER...AND IF I WERE
FORCED TO BET...BELIEVE CHANCES FOR SEEING RAIN PRIOR TO DAYBREAK
ACROSS THE WESTERN CWA IS MINIMAL. FOR FURTHER DISCUSSION....SEE
BELOW...

&&

.SHORT TERM...(WEDNESDAY THROUGH FRIDAY)
ISSUED AT 318 PM EDT TUE JUL 28 2015

HIGH IMPACT WEATHER POTENTIAL: NOT MUCH. STILL MONITORING
THUNDERSTORM CHANCES WEDNESDAY.

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: PATTERN SET TO MORPH INTO
ONE ALL-TO-FAMILIAR TO US NORTHERN MICHIGAN RESIDENTS...WITH CURRENT
OVERHEAD HEAT DOME SUCCUMBING TO NORTHERN PLAINS WAVE WEDNESDAY...
ALL-THE-WHILE SUBTROPICAL RIDGING RETROGRADES BACK INTO THE
INTERMOUNTAIN WEST. THIS WILL REESTABLISH COOLER NORTHWEST FLOW
ALOFT AS TROUGHING ONCE AGAIN BECOMES ESTABLISHED ACROSS NORTHEAST
NOAM.

PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE TRENDS THROUGHOUT
AND ADDRESSING SHOWER AND THUNDERSTORM CHANCES WEDNESDAY.

DETAILS: LOW CONFIDENCE FORECAST CONTINUES ON HOW TOMORROW`S SHOWER
AND STORM EVOLUTION WILL WORK OUT. CONFLICTING SIGNALS FOR
SURE...WITH NICE SURGE OF DEEP LAYER MOISTURE JUST AHEAD OF
APPROACHING COLD FRONT...AT LEAST PARTIALLY OFFSET BY
DELAYED/SHEARING OF MID LEVEL DYNAMICS AND NEARLY NON-EXISTENT UPPER
LEVEL JET SUPPORT. FRONTAL TIMING IS SLOWER...WHICH DOES AT LEAST
OFFER SOME OPPORTUNITY FOR SOLAR DRIVEN DESTABILIZATION...ESPECIALLY
ACROSS EASTERN AREAS. SIMPLY FEEL THE NEGATIVES ARE TOO MANY...AND
STILL EXPECT NOTHING MORE THAN A BROKEN/SCATTERED BAND OF SHOWERS
AND ISOLATED THUNDERSTORMS TO WORK WEST/EAST ACROSS OUR AREA.
POTENTIAL IS THERE FOR SOME DECENT RAINS FOR THOSE THAT ARE LUCKY
ENOUGH TO EXPERIENCE THE STORMS...BUT REALLY FEEL THIS WILL BE FEW
AND FAR BETWEEN. MAY SEE AN UPTICK IN ACTIVITY DURING THE AFTERNOON
ACROSS THE SUNRISE SIDE...PENDING DEGREE OF CLOUD COVER AND ITS
IMPACTS ON DESTABILIZATION. LACK OF MID/UPPER LEVEL SUPPORT COULD
SIMPLY PREVENT SUCH...BUT ANY STORMS THAT DO DEVELOP WILL NEED TO BE
MONITORED FOR SOME GUSTY WINDS WITH 25-30 KNOTS OF DEEP LAYER SHEAR
TO WORK WITH. LATEST DAY 2 SPC CONVECTIVE OUTLOOK STILL HAS MARGINAL
RISK FAR REMOVED TO OUR SOUTH...WHICH CONTINUES TO FIT THE OVERALL
FLAVOR OF THE SYNOPTIC FEATURES.

ANY LINGERING SHOWERS SHOULD BE HISTORY BY WEDNESDAY EVENING AS DRY
AIR OVERSPREADS THE REGION. TROUGHING AND NORTHWEST FLOW PREVAILS
THEREAFTER THROUGH FRIDAY...WITH EMBEDDED WEAK WAVES ROTATING
THROUGH SUCH. MOISTURE WILL BE SEVERELY LIMITED WITH EACH WAVE...AS
WILL ANY TYPE OF LOW LEVEL SURFACE CONVERGENCE (ALTHOUGH WILL NEED
TO MONITOR INTERIOR EASTERN UPPER WITH BACKGROUND WEST WINDS PERHAPS
ALLOWING A NARROW RIBBON OF ENHANCED CONVERGENCE). IDEA FOR NOW IS
TO SIMPLY RIDE WITH A DRY FORECAST...WITH ANY RAINFALL BEING LIMITED
AND MINOR AT BEST. BIGGER STORY NO DOUBT WILL BE TEMPERATURES...WITH
HIGHS BOTH THURSDAY AND FRIDAY BACK DOWN TO NEAR NORMAL LEVELS.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 318 PM EDT TUE JUL 28 2015

MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE EXTENDED PERIOD. A
BROAD AREA OF LOW PRESSURE OVER HUDSON BAY WILL BRING THE OCCASIONAL
COLD FRONT AND SHORTWAVE TROUGH THROUGH THE GREAT LAKES REGION
PRODUCING ON AND OFF CHANCES OF SHOWERS AND THUNDER TO THE FORECAST
AREA THROUGHOUT THE PERIOD. SUNDAY APPEARS TO HAVE THE BEST CHANCE
FOR PRECIPITATION ALONG A PASSING COLD FRONT. SKIES WILL REMAIN
MOSTLY CLEAR TO PARTLY CLOUDY THROUGHOUT THE PERIOD WITH THE
EXCEPTION OF SUNDAY...PARTLY TO MOSTLY CLOUDY. HIGH TEMPERATURES
WILL REMAIN IN THE UPPER 70S TO LOW 80S...WHILE LOWS WILL BE IN THE
MID 50S TO NEAR 60.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 713 PM EDT TUE JUL 28 2015

VFR CIGS AND VSBYS TO REMAIN ACROSS THE NRN LAKES TAF SITES THIS
EVENING...THE RESULT OF A LARGE AREA OF HIGH PRESSURE CENTERED ON
THE MID ATLANTIC. THUNDERSTORMS ALONG WITH MVFR CIGS AND VSBYS ARE
EXPECTED OVERNIGHT INTO WEDNESDAY AFTERNOON...AS A STORM SYSTEM
CURRENTLY ORGANIZING OVER THE NRN PLAINS PUSHES INTO THE WRN
LAKES. CONVECTION IS EXPECTED TO DIMINISH AROUND 18Z FOR TAF SITES
PLN- TVC- MBL...ENDING FOR TAF SITE APN AFT 21Z WED.


&&

.MARINE...
ISSUED AT 318 PM EDT TUE JUL 28 2015

WINDS WILL INCREASE AHEAD OF AN APPROACHING COLD FRONT TONIGHT INTO
WEDNESDAY MORNING...BUT STABLE CONDITIONS OVER THE LAKES WILL LIKELY
KEEP ADVISORY LEVEL WINDS FROM DEVELOPING. BEST CHANCE WOULD BE
ALONG THE NW LOWER COASTLINE DUE TO COASTAL CONVERGENCE. THIS COLD
FRONT WILL BRING CHANCES FOR SHOWERS AND STORMS TOWARD DAYBREAK AND
INTO WEDNESDAY...BUT NOTHING SEVERE IS EXPECTED. BETTER LOW LEVEL
COOLING DEVELOPS THURSDAY INTO FRIDAY...TO KNOCK DOWN THE STABILITY
SOME...BUT WINDS WILL LIKELY NOT BE STRONG ENOUGH FOR ADVISORIES.


&&

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

$$

UPDATE...SWR
NEAR TERM...SMD
SHORT TERM...MSB
LONG TERM...TJL
AVIATION...SWR
MARINE...SMD



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