000
FXUS63 KMQT 172311
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
711 PM EDT MON JUN 17 2013

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 400 PM EDT MON JUN 17 2013

WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER NRN
QUEBEC RESULTING IN WNW FLOW THROUGH GREAT LAKES. AT THE SFC...HIGH
PRES OVER NRN ONTARIO AND NRN MANITOBA WAS BUILDING SOUTHWARD INTO
THE NRN LAKES. WEAK 850-700 MB FGEN SUPPORTED A BAND OF DIMINISHING
LIGHT RAIN SHOWERS OR SPRINKLES OVER S CNTRL UPPER MI.
OTHERWISE...THE LOW CLOUDS OVER NRN UPPER MI HAD DISSIPATED LEAVING
MAINLY JUST SCT-BKN MID CLOUDS. FARTHER SOUTH...A WEAK SHORTWAVE
TROUGH INTO NRN WI SUPPORTED SCT TSRA OVER N CNTRL WI IN AREA WHERE
SFC HEATING HAD PUSHED MLCAPES INTO THE 500-1000 J/KG RANGE. MLCAPE
VALUES AND TSRA MOTION SUGGESTS THE TSRA WILL REMAIN SOUTH OF THE
CWA.

TONIGHT...THE MODELS WERE CONSISTENT IN BRINGING CLEARING ACROSS THE
REGION. WITH PWAT VALUES FALLING TO NEAR 0.30 INCH OVER THE WEST(35
PCT OR NORMAL) FAVORABLE RADIATIONAL COOLING CONDITIONS WILL ALLOW
TEMPS TO DROP TO NEAR THE LOWER END OF GUIDANCE. UPSTREAM OBS FROM
LAST NIGHT N OF LAKE SUPERIOR SUGGEST THAT TEMPS COULD FALL INTO THE
33F TO 36F RANGE OVER FAVORED COLDER LOCATIONS OVER THE INTERIOR
WEST HALF. SO...SOME PATCHY FROST WILL BE POSSIBLE. WITH THE LIGHT
RAIN THIS AFTERNOON INTO PORTION OF THE SOUTHWEST AND DELAYED
CLEARING/MIXING...LOW LEVEL MOISTURE MAY BE SLIGHTLY HIGHER THAN
EARLIER EXPECTED. SO...WAS NOT AS CONFIDENT IN MORE WIDESPREAD FROST
THAT WOULD REQUIRE AN ADVISORY.

TUE...SUNSHINE AND MIXING TO AROUND 800 MB SUPPORTS MAX TEMPS INTO
THE LOWER 70S INLAND AND DEWPOINTS INTO THE MID 30S RESULTING IN RH
VALUES TO NEAR 25 PCT. WITH HIGH PRESSURE AND LIGHT WINDS OVER THE
REGION...LAKE BREEZES WILL KEEP TEMPS IN THE 60S CLOSER TO THE GREAT
LAKES.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 400 PM EDT MON JUN 17 2013

THE START OF THE LONG TERM PERIOD WILL BE QUIET...AS THE AREA IS
UNDER NORTHWEST FLOW ALOFT AND A DRY SURFACE OVER THE UPPER GREAT
LAKES REGION. THIS WILL PRODUCE CLEAR SKIES AND A PLEASANT JUNE
NIGHT ACROSS THE AREA. AS THE HIGH SHIFTS SOUTHEAST INTO THE LOWER
GREAT LAKES ON WEDNESDAY...SOUTHWESTERLY LOW LEVEL FLOW WILL BE ON
THE INCREASE AND PUSH 850MB TEMPS UP TO 10C. WITH DEEP MIXING TO
800-750MB...WOULD EXPECT HIGHS TO RISE INTO THE MID-UPPER 70S. IN
ADDITION...WITH THE DEEP MIXING AND DRY LOW LEVEL AIR...HAVE
FOLLOWED MIXED LAYER DEWPOINTS FOR INTERIOR LOCATIONS /UPPER 30S TO
MID 40S/...LOWEST OVER THE EAST. THIS PRODUCES MINIMUM RH VALUES
AROUND 30 PERCENT OVER THE EAST. WIND SHOULDN/T BE TOO GUSTY THROUGH
THE FIRST PART OF WEDNESDAY...BUT WITH THE FLOW INCREASING THROUGH
THE DAY THERE COULD BE SOME GUSTS TO 15-20MPH IN THE MID-LATE
AFTERNOON. THIS COULD END UP PRODUCING MARGINAL FIRE WX CONCERNS FOR
THE CENTRAL/EASTERN UPPER MICHIGAN WHERE PRECIPITATION IS A LITTLE
BELOW NORMAL OVER THE LAST 30 DAYS.

ATTENTION FOR THE LONG TERM THEN TURNS TO A SERIES OF SHORTWAVES
THAT WILL BE AFFECTING THE AREA FOR THE WEDNESDAY NIGHT INTO THE
WEEKEND. THE FIRST WAVE WILL BE DROPPING SOUTHEAST ACROSS NORTHERN
LAKE SUPERIOR ON WEDNESDAY NIGHT...WITH AN ASSOCIATED WEAK SURFACE
COLD FRONT/TROUGH PUSHING THROUGH. WITH IT BEING NEAR THE MN
ARROWHEAD AROUND PEAK HEATING ON WEDNESDAY...THERE WILL LIKELY BE
SHOWER/THUNDERSTORM DEVELOPMENT THERE AND NORTHWEST OF LAKE SUPERIOR
IN ONTARIO. WITH THE FORECASTED STORM MOTION...THESE
SHOWERS/THUNDERSTORMS WILL MOVE SOUTHEAST INTO WESTERN LAKE SUPERIOR
ON WEDNESDAY AFTERNOON AND WILL CONTINUE TO MENTION SLIGHT CHANCE
POPS THERE. QUESTION IS HOW MUCH THEY WILL DIMINISH AS DIURNAL
HEATING IS LOST AND IT RUNS INTO THE EXISTING DRY AIR FROM THE HIGH.
THE BEST FORCING/MOISTURE IS CLOSER TO THE SHORTWAVE MOVING ACROSS
NORTHERN LAKE SUPERIOR...SO WILL FOLLOW THAT IDEA FOR THE HIGHEST
POPS AND THEN DIMINISH THE REST AS THEY DROP SOUTHEAST THROUGH THE
NIGHT.

FRONT LOOKS TO STALL OVER THE AREA ON THURSDAY. DIURNAL
HEATING WILL COMBINE WITH WEAK LAKE BREEZES TO AID CONVECTION
DEVELOPMENT. THINK THE BEST INTERACTION WITH THE CONVERGENCE
AND INSTABILITY /ML CAPE VALUES TO AROUND 1000 J/KG/ WILL BE OVER
THE CENTRAL PORTIONS OF THE CWA. HAVE TRENDED POPS UP TO HIGH
CHANCE AND LOW LIKELY VALUES WITH THE CONSISTENCY IN THE MODELS.
0-6KM BULK SHEAR VALUES ARE ON THE MARGINAL SIDE /25-30KTS/ AND
WITH CAPE FAIRLY TALL/SKINNY...WOULD THINK HEAVY RAIN WOULD BE THE
BIGGEST CONCERN WITH RELATIVELY SLOW STORM MOTIONS OF 20KTS
ALTHOUGH SMALL HAIL CAN/T BE RULED OUT.

MEANWHILE...UPPER RIDGE IN THE SOUTHERN STREAM WILL BUILD INTO THE
NORTHERN PLAINS ON THURSDAY AND THE FORECAST FOR THURSDAY NIGHT
INTO THE WEEKEND WILL DEPEND ON A SERIES OF SHORTWAVES ROUNDING THE
RIDGE AND SLIDING THROUGH THE CWA. THIS MAKES PINNING DOWN POPS A
LITTLE DIFFICULT AS THEY WILL DEPEND ON CONVECTION DEVELOPING
UPSTREAM AND MOVING THROUGH. AT THIS POINT...IT SEEMS LIKE THE
WAVES WILL COME LATE THURSDAY NIGHT INTO FRIDAY...LATE FRIDAY NIGHT
THROUGH SATURDAY EVENING...AND AGAIN ON SUNDAY. WILL HIGHLIGHT
THOSE PERIODS FOR THE HIGHEST POPS. INSTABILITY WILL BE ON THE
INCREASE THROUGH THAT PERIOD...SO THUNDERSTORMS ARE POSSIBLE WITH
EACH OF THE WAVE. SEVERE THREAT WILL LARGELY DEPEND ON WHERE THE
WARM FRONT WILL LINE UP ON THE EAST SIDE OF THE NEARLY STATIONARY
LOW IN THE NORTHERN PLAINS AND THE EXACT LOCATION OF THE
SHORTWAVES. WITH THE SOURCE REGION FOR THE THUNDERSTORMS GETTING
CLOSER INTO THE WEEKEND...WOULD THINK THE SEVERE THREAT WILL BE ON
THE RISE. THIS IS ESPECIALLY TRUE FOR THE BEGINNING OF THE
WEEKEND...AS INSTABILITY BEGINS TO PEAK AND THE OVERALL PATTERN
LOOKS CONDUCIVE FOR AN MCS FORMING IN THE UPPER MISSISSIPPI VALLEY
AND ROLLING THROUGH THE UPPER GREAT LAKES. CIPS WARM SEASON ANALOGS
FROM THE 12Z GFS ALSO SHOW AN INCREASING SEVERE THREAT TOWARDS
SATURDAY...SO IT WILL DEFINITELY BE SOMETHING TO WATCH OVER THE
COMING DAYS.

THE RIDGE LOOKS TO BREAK DOWN BY THE SECOND HALF OF THE WEEKEND AND
THE AREA WILL COME UNDER MORE ZONAL TO START THE NEXT WORK WEEK.
CONFIDENCE REALLY DIMINISHES FOR THIS PERIOD AS IT WILL ALL DEPEND
ON SMALLER SCALE FEATURES. IN GENERAL...IT APPEARS THE BOUNDARY
THAT WILL BRING THE CONVECTION TO THE AREA FOR THE END OF THIS WEEK
WILL SAG SOUTH AND FOCUS THE BETTER OPPORTUNITY FOR CONVECTION
SOUTH OF THE AREA.

WARM AND HUMID CONDITIONS ARE EXPECTED THURSDAY INTO THE
WEEKEND...WITH DEWPOINTS RISING INTO THE 60S. ADDED PATCHY FOG OVER
LAKE SUPERIOR FOR WEDNESDAY NIGHT THROUGH MONDAY WITH THE EXPECTED
PRECIPITATION AND HUMID CONDITIONS. MAY NEED TO INCREASE IT IN
COVERAGE IN THE FUTURE AND ALSO EXPAND IT INTO LAKE MICHIGAN.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 711 PM EDT MON JUN 17 2013

WITH HIGH PRESSURE IN CONTROL...VFR CONDITIONS EXPECTED TO CONTINUE
THROUGH THE PERIOD.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 PM EDT MON JUN 17 2013

WINDS ARE EXPECTED TO STAY BELOW 20KTS THROUGH THE PERIOD. HIGH
PRESSURE BUILDING OVER THE UPPER GREAT LAKES TONIGHT WILL REMAIN
THROUGH WEDNESDAY. A WEAK TROUGH WILL THEN APPROACH THE AREA
FROM THE NORTHWEST FOR THURSDAY.
&&

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

$$

SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB