Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 300528
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
128 AM EDT TUE JUN 30 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 349 PM EDT MON JUN 29 2015

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALF OVER
THE UPR GREAT LKS BTWN TROF OVER ERN NAMERICA AND HI AMPLITUDE UPR
RDG OVER THE ROCKIES. SHRTWV EMBEDDED IN THE NW FLOW AND ON CYC SIDE
OF RIBBON OF FASTER MID LVL WINDS OVER THE NRN PLAINS INTO MN IS
MOVING INTO NRN MN. COMBINATION OF DAYTIME HEATING AND DPVA/DEEP LYR
QVECTOR CNVGC/AXIS OF DEEPER MSTR/PWAT NEAR 1.30 INCHES AHEAD OF
THIS FEATURE HAS TRIGGERED SCT-NMRS SHOWERS/TS OVER MAINLY THE W
HALF OF THE CWA WHERE MUCAPE IS HIER NEAR 1500 J/KG. WITH SFC-6KM
SHEAR NO GREATER THAN 15 TO 20 KTS OVER THE WRN CWA...STORMS HAVE
BEEN PULSY/DISORGANIZED IN OUR CWA TO THE E OF A MORE IMPRESSIVE BOW
ECHO THAT HAS PLOWED THRU NE MN/WRN WI. SO THERE HAVE NO SVR WX
REPORTS IN THE MQT CWA. THERE APPEARS TO BE A 2ND WEAKER SHRTWV
DIGGING SEWD THRU MANITOBA AND INTO FAR NW ONTARIO THAT IS
MAINTAINING SOME COLDER CLD TOPS IN THAT AREA. A SFC COLD FNT
ASSOCIATED WITH THIS FEATURE IS SINKING SEWD TOWARD NW LK SUP.

MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/TS CHANCES
ASSOCIATED WITH PAIR OF SHRTWVS NOTED ABOVE.

TNGT...STRONGER SHRTWV NOW PASSING THRU MN IS PROGGED TO CONTINUE TO
THE SSE TO NEAR CHICAGO BY 12Z TUE WHILE SECOND DISTURBANCE MOVES TO
NEAR THE KEWEENAW. ALTHOUGH THE FIRST DISTURBANCE IS STRONGER...THE
SLOWER SECOND SHRTWV IS FCST TO MAINTAIN DEEP LYR QVECTOR CNVGC/AREA
OF DEEPER MSTR OVER MUCH OF THE CWA THRU THE NGT. SO EVEN THOUGH
NOCTURNAL COOLING WL ACT TO LIMIT CONVECTION...THIS FORCING AND
DEEPER MSTR AHEAD OF APRCHG COLD FNT WL MAINTAIN HIER POPS. ALTHOUGH
SOME OF THE STORMS IN THE EVNG ACROSS MAINLY THE W HALF OF THE CWA
CLOSER TO THE HIER H85 THETA E/MUCAPE VALUES MIGHT BE MARGINALLY
SVR...LACK OF SGNFT MSTR INFLOW INTO THE CWA/WEAK DCAPE AND
DIMINISHING INSTABILITY OVERNGT WL LIMIT THE THREAT FURTHER. MID LVL
DRYING/DEEP LYR QVECTOR DVGC IS FCST TO IMPACT THE FAR W LATE...SO
WL FCST DIMINISHING POPS THERE OVERNGT. BUT MOIST LLVL NNW FLOW
BEHIND ASSOCIATED COLD FROPA WL MAINTAIN QUITE A BIT OF LO CLD AND
ADVECT SOME FOG INLAND OFF LK SUP INTO THE NW CWA OVERNGT.

TUE...AS SECOND SHRTWV SLIDES SLOWLY TO THE SE...LINGERING DYNAMIC
FORCING/DEEP MSTR OVER THE ERN CWA IN THE MRNG IS FCST TO EXIT IN
THE AFTN AND GIVE WAY TO MID LVL SUBSIDENCE/DRYING. SO WL MAINTAIN
FLAVOR OF GOING FCST THAT SHOWS DIMINISHING POPS NW-SE. WSHFT TO THE
NNW/SHALLOW INFUSION OF COLD AIR BEHIND COLD FROPA WL SUPPORT
EXPANSION OF LO CLDS TO THE SE. THIS LO CLD/PERHAPS SOME DRIZZLE WL
BE MOST PERSISTENT OVER THE UPSLOPE HIER TERRAIN NEAR LK SUP.
FARTHER INLAND...THE COMBINATION OF DAYTIME HEATING AND ADVECTION OF
LLVL DRIER AIR MAY ALLOW FOR SOME SUNSHINE LATE IN THE DAY.
CONSIDERING THE LLVL INFUSION OF COOL AIR WITH STEADY N WIND OFF THE
CHILLY LK WATERS...LOWERED FCST MAX TEMPS. THE MERCURY SHOULD HOLD
IN THE 50S AT MOST PLACES NEAR LK SUP.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 403 PM EDT MON JUN 29 2015

DECENT AGREEMENT IN OVERALL LOOK OF LARGE SCALE PATTERN THROUGH THE
4TH OF JULY WEEKEND. TROUGHING OVER EASTERN CANADA AND THE GREAT
LAKES PERSISTS THROUGH THE WEEK...WITH RIDGING ALOFT BRIEFLY MOVING
OVER THE GREAT LAKES FOR THE WEEKEND. HOLIDAY WEEKEND AT THIS POINT
LOOKS MAINLY DRY WITH TEMPS AT OR ABOVE NORMAL. BEST CHANCE OF
SHOWERS AND THUNDERSTORMS FOR THE EXTENDED OCCURS SUNDAY NIGHT AND
MONDAY AS STRONGER TROUGH ALOFT AND SFC COLD FRONT WORK OVER THE
UPPER GREAT LAKES REGION.

TO START THE LONG TERM...TUESDAY NIGHT INTO WEDNESDAY MORNING MAIN
CONCERN WILL BE LOW CLOUDS. NAM/GFS SOUNDINGS INDICATES MOISTURE
LINGERS 950-900MB WELL INTO TUESDAY NIGHT AND POSSIBLY WEDNESDAY
MORNING. NE WINDS OFF LK SUPERIOR BTWN DEPARTING TROUGH AND NEARING
RIDGE SHOULD ALSO LEAD TO SLIGHT CHANCES OF SHOWERS INTO TUESDAY
EVENING NEAR LK SUPERIOR NCNTRL WITH UPSLOPE FLOW. OVERALL HIT UP
CLOUDS MORE ON TUESDAY NIGHT AND REMOVED CHANCES OF FOG. SKIES WILL
CLEAR OUT ON WEDNESDAY. EVEN WITH THE SUNSHINE...THERMAL TROUGH IN
LOW-LEVELS WILL KEEP TEMPS BELOW NORMAL WITH 50S NEAR LK SUPERIOR
AND IN THE 60S ELSEWHERE. SFC RIDGE SETTLES ACROSS UPPER LAKES
WEDNESDAY NIGHT INTO THURSDAY. GIVEN PWATS BLO 0.5 INCH AND LIGHT
WINDS...EXPECT MIN TEMPS IN UPR 30S TO LOW 40S FOR THE COOLER SPOTS
ON WEDNESDAY NIGHT. LAKE BREEZES SHOULD RULE ON WEDNESDAY...BUT
SOUNDINGS REMAIN QUITE DRY AND WITH DEEPER MIXING...DWPNTS IN AFTN
SHOULD FALL BACK INTO 30S OR 40S. NAM DWPNTS WHICH TYPICALLY HAVE
HIGH BIAS SHOW MID 30S...SO THAT INDICATES HOW DRY THE AIRMASS LOOKS
TO BE. MAY BE MORE CU THAN MODELS INDICATE ALONG LAKE BREEZES...BUT
TOO DRY TO INCLUDE ANY POP-UP SHRA.

SCATTERED SHRA/TSRA APPEAR POSSIBLE ON FRIDAY AS SHORTWAVE TROUGH
SLIDES OVER ONTARIO AND SOUTHERN PORTION OF THIS WAVE MOVES INTO
UPPER LAKES DURING PEAK HEATING. STRONGEST DEEP LAYER Q-VECTOR
CONVERGENCE STAYS OVER NORTHERN ONTARIO...BUT FRONT SLIDING TOWARD
UPR LAKES COMBINED WITH DAYTIME HEATING AND LAKE BREEZES COULD BE
ENOUGH TO TRIGGER SHRA/TSRA. LOW-LEVEL MOISTURE IS MARGINAL AND
FRONT IS NOT VERY STRONG...SO APPEARS LIKE ONLY LOW-CHANCES AT THIS
POINT.

AS ALLUDED TO EARLIER...THINKING NOW IS THAT JULY 4TH WILL BE DRY AS
HIGH PRESSURE WORKS OVER THE AREA IN WAKE OF THE FRONTAL PASSAGE ON
FRIDAY/FRIDAY NIGHT. BECOMING WARMER AS H85 TEMPS RISE TOWARD +14C
BY END OF SATURDAY...BUT PROBABLY NOT ENOUGH LOW-LEVEL MOISTURE AND
RESUTING INSTABILITY AROUND GIVEN OVERALL HIGHER HEIGHTS TO GENERATE
ANY CONVECTION EVEN WITH THE PRESENCE OF LAKE BREEZES. WARMER YET ON
SUNDAY AS H85 TEMPS RISE TOWARD +15C. WINDS MAINLY SOUTHERLY AHEAD
OF NEXT FRONT...WHICH WILL KEEP LAKE MODIFICATION RESTRICTED TO
EASTERN CWA OFF LK MICHIGAN. GIVEN ENOUGH SUNSHINE...MAX TEMPS ON
SUNDAY COULD SURGE WELL INTO THE 80S FOR MUCH OF THE WEST HALF.
CONSENSUS POPS OF HIGHER CHANCES SEEMED GOOD FOR SUNDAY NIGHT AS
SHORTWAVE TROUGH AND COLD FRONT CROSS UPR MICHIGAN. SFC-H85 THETA-E
RIDGING AHEAD OF THE FRONT AND STRONGER DYNAMICS SUPPORT THE BEST
CHANCE FOR ORGANZED SHRA/TSRA THROUGH THE LONG RANGE PERIOD.
LINGERING CHANCES FOR SHRA/TSRA NEXT MONDAY...WITH TIMING AND
COVERAGE DETAILS TO BE WORKED OUT IN LATER FORECASTS.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 127 AM EDT TUE JUN 30 2015

WITH PASSAGE OF COLD FRONT AND WSHFT TO THE NNW...THE UPSLOPE FLOW
OFF LAKE SUPERIOR WILL BRING LOW CLOUDS/FOG AND LIFR CONDITIONS TO
KIWD/KCMX/KSAW OVERNIGHT. EXPECT -SHRA/-DZ AT TIMES...ESPECIALLY AT
KSAW. BY LATE MORNING/EARLY AFTN...DAYTIME HEATING AND ARRIVAL OF
SOME DRIER LOW-LEVEL AIR WILL LIKELY LEAD TO IMPROVEMENT AT
KIWD/KCMX...BUT KSAW SHOULD REMAIN IFR THRU AT LEAST MID AFTN WITH A
SLOWER ARRIVAL OF THE DRIER AIR AND A MORE FAVORABLE UPSLOPE WIND
COMPONENT. KIWD/KCMX SHOULD BREAK OUT TO VFR DURING THE LATTER HALF
OF THE AFTN. IMPROVEMENT TO VFR SHOULD OCCUR AT KSAW IN THE
EVENING...BUT THERE ARE SOME INDICATIONS THAT MVFR CONDITIONS MAY
LINGER.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 349 PM EDT MON JUN 29 2015

FOR THE MOST PART...EXPECT LIGHT WINDS BELOW 20 KNOTS THROUGH THE
ENTIRE FORECAST PERIOD. THE ONE EXCEPTION WILL BE THE NCENTRAL LAKE
LATE TONIGHT INTO TUE AFTERNOON. N WINDS UP TO 25 KTS WILL FOLLOW
THE PASSAGE OF THIS FRONT IN THAT AREA BEFORE DIMINISHING WITH THE
ARRIVAL OF HI PRES LATE IN THE DAY. EXPECT PATCHY FOG TO PERSIST
ACROSS THE LAKE THROUGH TUE AS A RELATIVELY MOIST AIRMASS REMAINS
OVER THE REGION. THE ARRIVAL OF DRIER LLVL AIR WL DISSIPATE ANY
LINGERING FOG BY WED MORNING.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...KC



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