000
FXUS63 KMQT 131720
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
120 PM EDT THU JUN 13 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 443 AM EDT THU JUN 13 2013

LOTS OF STRONG TSRA AND LIGHTNING OVER THE LOWER GREAT LAKES AND
OHIO VALLEY THIS MORNING AHEAD OF STRONGER SHORTWAVE TROUGH AND SFC
LOW/WARM FRONT CROSSING THAT AREA. CLOSER TO HOME...WV LOOP
INDICATES NORTHERN BRANCH TROUGHING CLOSE BY OVER ONTARIO INTO
QUEBEC. MAIN WAVE WITHIN THAT TROUGH IS SLIDING SOUTH OF JAMES BAY
BUT ASSOCIATED LOW-LEVEL TROUGH AXIS IS JUST TO NORTH OF LK SUPERIOR
AS OF 05Z. AS THE SHORTWAVE MOVES INTO QUEBEC EXPECT THE SFC-H85
TROUGH TO DROP ACROSS UPR LAKES THIS MORNING. SFC TEMPS IMMEDIATELY
IN WAKE OF TROUGH IN ONTARIO NOT TOO DIFFERENT THAN CURRENT READINGS
OVER UPR MICHIGAN. COOLING AT 925-850MB IS SEEN THOUGH WITH H85
TEMPS DOWN TO +8C AT CWPL WHILE READINGS AT MPX/GRB AND APX WERE
AROUND +13C. SIMILAR COOLING AT 925MB WITH +20C AT APX FALLING OFF
TO +10C AT CWPL AND +13C AT CWZC /MOOSONEE ONTARIO AT SOUTH SHORE OF
JAMES BAY/. AT 00Z...ONLY UPSTREAM SOUNDING THAT SHOWED LOW-LEVEL
MOISTURE WAS CWZC AND NIGHTTIME SATELLITE IMAGERY AND AVAILABLE OBS
IN ONTARIO ARE SHOWING SOME SCT-BKN MVFR CLOUDS THUS FAR...THOUGH
07Z IMAGERY INDICATES LOW CLOUDS MAY BE STARTING TO FORM OVR HURON
MOUNTAINS. MODELS COMPARED WELL TO EACH OTHER INITIALIZING SFC
THROUGH H5 FEATURES UPSTREAM. NAM INITIALIZED SOUNDINGS AT CWPL AND
CWZC WELL. WILL LEAN ON THE NAM AND RUC13 FOR LOW-LEVEL MOISTURE
FORECASTS FOR TODAY OVR CWA.

FROM A FORECAST STANDPOINT...ENCOURAGED TO SEE LOWER CLOUDS
STARTING TO FORM. THINK IDEA OF BKN LOW CLOUDS THIS MORNING STILL
ON TRACK...ESPECIALLY FOR UPSLOPE AREAS OF NCNTRL UPR MICHIGAN. HAVE
STRUGGLED ON WHAT TO DO WITH DRIZZLE CHANCES. WAS GOING TO PULL
MENTION BASED ON RUC SOUNDINGS WHICH SHOWED LINGERING DRYING BENEATH
HIGHER MOISTURE 950-900MB. ULTIMATELY DECIDED TO KEEP MENTION IN FOR
HIGHER TERRAIN OF MARQUETTE COUNTY AS T/TD DEPRESSION AT STDM4
HAS STEADILY NARROWED OVER THE LAST FEW HOURS. THINK THIS MOISTENING
COMBINED WITH UPSLOPE FLOW COULD STILL RESULT IN LGT DRIZZLE OR
SPRINKLES. DRIZZLE WILL ONLY BE AROUND FOR THE MORNING. ONCE CLOUDS
SET UP...THINK THEY MAY STUBBORN TO LEAVE AS THERMAL TROUGHING FM
925-850MB PERSISTS ALONG WITH A CYCLONIC CONVERGENT NNE FLOW
925-850MB. KEPT BKN CLOUDS IN THROUGH EARLY AFTN WITH SCT CLOUDS
CLOUDS STAYING AROUND THROUGH MID AFTN IN THOSE UPSLOPE AREAS.
EVEN AWAY FM FAVORED AREAS NEAR LK SUPERIOR...THERMAL TROUGHING AND
DAYTIME HEATING SHOULD ACT TO INCREASE CU FOR A WHILE BEFORE
CLOUDS SCATTER OUT LATE TODAY. EXPECT RAPID CLEARING OF SKIES
LATE THIS AFTN/EARLY THIS EVENING AS SHARP 925-850MB DRYING WITH
DWPNT DEPRESSIONS OVER 15C SURGES INTO THE REGION FROM ONTARIO.

ONE ITEM TO NOTE ABOUT TODAY. A MODERATE SWIM RISK IS IN PLACE FOR
SHORELINES OF MARQUETTE AND ALGER COUNTIES AS WAVES BUILD TO 2 TO 4
FEET. LOWERING WAVES WILL LESSEN THE SWIM RISK BY THIS EVENING.

FOR TONIGHT...A COOL NIGHT IN STORE DUE TO THE CLEARING SKIES AND
LIGHT WINDS AS HIGH PRESSURE RIDGE CURRENTLY OVER MANITOBA DROPS
ACROSS REGION. WINDS FCST TO BECOME CALM OVER INTERIOR WEST CWA
WHICH WILL RESULT IN TEMPS FALLING INTO THE UPR 30S...MAYBE EVEN MID
30S. CURRENT READINGS BENEATH THE HIGH IN MANITOBA HAVE ALREADY INTO
UPR 30S AS OF 07Z. KEPT THE FROST MENTION FOR INTERIOR WEST...BUT IT
REMAINS TOO ISOLD TO MENTION IN THE HWO OR SFP.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 443 AM EDT THU JUN 13 2013

FRI...HI PRES IS FCST TO BE CENTERED OVER THE E HALF OF LK SUP ON
FRI AFTN TO THE E OF UPR RDG AXIS EXTENDING FM THE CENTRAL PLAINS
THRU THE UPR MS RIVER VALLEY AND INTO SCENTRAL CANADA DOWNSTREAM OF
CLOSED LO OVER THE CANADIAN ROCKIES JUST N OF THE BORDER. ALTHOUGH
SOME HI CLDS IN THE DVLPG SLY FLOW/WAD PATTERN BTWN THE HI AND LOWER
PRES TO THE W MAY DRIFT INTO THE WRN COUNTIES IN THE AFTN...THE DAY
SHOULD FEATURE A GOOD DEAL OF SUNSHINE WITH LLVL DRY AIRMASS IN
PLACE. H85 TEMPS FCST IN THE 11-12C RANGE AND MIXING TO H8 ON FCST
SDNGS YIELDS HI TEMPS WELL INTO THE 70S OVER THE INTERIOR W HALF
AWAY FM LK MODERATION. THE DEEP MIXING AND DRY AIRMASS IN PLACE WL
CAUSE SFC DEWPTS TO FALL INTO THE 20S IN THE AFTN OVER THE
INTERIOR...WITH MIN RH AS LO AS 20 PCT OVER THE E CLOSER TO THE CORE
OF DRIEST AIR. FORTUNATELY...WINDS WL BE LGT...SO FIRE WX CONCERNS
SHOULD BE MINIMAL.

FOCUS FOR FRI NGT THRU THE WEEKEND WL THEN SHIFT TO PCPN CHCS
ASSOCIATED WITH BROAD SW FLOW BTWN HI PRES RETREATING INTO THE MID
ATLANTIC STATES AND CLOSED LO THAT DRIFTS ONLY SLOWLY E ACRS SRN
CANADA AND TOWARD THE UPR LKS BY LATE SUN. GUIDANCE IN GOOD
AGREEMENT SHOWING SOME DEEP LYR ISENTROPIC ASCENT DVLPG ON FRI NGT
WITH BAND OF HIER MID LVL RH MOVING IN FM THE W. BUT GIVEN THE
DRYNESS OF THE ANTECENT AIRMASS...TENDENCY FOR MOST IMPRESSIVE DEEP
LYR QVECTOR CNGVC TO REMAIN WELL TO THE NW CLOSER TO THE LO ALLOWING
A MORE PERSISTENT UPR RDG AXIS OVER THE UPR LKS...AND PRESENCE OF
WARM FNT IN IOWA/ILLINOIS THAT WL INTERCEPT THE BULK OF RETURNING
LLVL MSTR...TRIMMED BACK THE EWD ADVANCE OF THE FRI NGT POPS SHOWN
IN PREVIOUS FCST TO MORE ALIGN WITH 00Z NAM/GFS/CNDN FCSTS. MIN
TEMPS ON FRI NGT SHOULD BE COOLEST OVER THE E CLOSER TO RETREATING
HI PRES RDG/DRIER AIR.

SAT/SAT NGT...NOT SURPRISINGLY...SGNFT MODEL DIFFERENCES BEGIN TO
SHOW UP IN THIS TIME PERIOD. THERE IS GOOD AGREEMENT ON PROGRESSION
OF BAND OF HIER MID LVL RH ALIGNED WITH DEEP ISENTROPIC ASCENT AND
AHEAD OF SHRTWV MOVING E THRU SW ONTARIO WELL IN ADVANCE OF SLOWER
CLOSED LO IN SASKATCHEWAN. THIS BAND OF HIER RH IS FCST TO DRIFT E
ACRS UPR MI FOLLOWED BY MID LVL DRYING IN THE JET SURGE REGION ON
THE SRN FLANK OF THE SHRTWV MOVING THRU SW ONTARIO. THE 00Z GFS IS
THEN MOST AGGRESSIVE AT DVLPG MORE SHRA/TS OVER THE W IN THE AFTN
WITH SHRTWV INTERACTING WITH THE GREATER INSTABILITY ALLOWED BY CLRG
IN THE WAKE OF THE DEPARTING MSTR AXIS. THE GFS THEN MOVES THESE
SHRA/TS E ACRS THE CWA ON SAT NGT. THE 00Z NAM ON THE OTHER HAND IS
VERY AGGRESSIVE WITH THE MID LVL JET SURGE DRYING...WITH FCST SDNGS
SHOWING EFFECTIVE MID LVL CAPPING AND ALMOST NO PCPN. PREFER THE
COMPROMISE 00Z CNDN MODEL HANDLING OF THE POPS GIVEN BETTER
PLACEMENT OF THE FEATURES RELATIVE TO CLOSED LO LINGERING BACK W OF
LK WINNIPEG THRU 12Z SUN...WITH LESS AGGRESSIVE MID LVL DRYING THAN
THE NAM AND LESS DYNAMIC SUPPORT FOR INSTABILITY SHRA/TS OVER THE W
THAN SHOWN BY THE GFS LATE SAT AFTN/NGT. BUT PASSAGE OF THIS WEAKER
SHRTWV STILL WARRANTS CHC POPS ON SAT NGT AS INDICATED BY THE CNDN
MODEL.

SUN...THERE IS A GENERAL MODEL CONSENSUS SHRTWV RDG BTWN DEPARTING
WEAK SHRTWV TO THE E AND SLOWLY APRCHG CLOSED LO FCST TO OPEN AND
APRCH NW MN LATE IN THE DAY WL BE AN INFLUENCE ON UPR MI WX. THE
RESULT SHOULD BE MAINLY DRY WX OVER THE CWA ON SUN. SO LOWERED MODEL
CONSENSUS POPS A BIT TO REFLECT THE MID LVL DRYING FCST/LACK OF
DYNAMIC SUPPORT...WHICH IS FCST TO ARRIVE ONLY LATER IN THE DAY OVER
THE W CLOSER TO APRCHG SHRTWV.

SUN NGT/MON... BEST CHC FOR SHRA/SOME TS LOOKS TO BE ON SUN NGT INTO
MON WHEN DPVA/FAIRLY VIGOROUS DEEP LYR QVECTOR CNVGC/HGT FALLS
ASSOCIATED WITH APRCHG SHRTWV FM THE WNW IMPACT THE CWA. MODEL
CONSENSUS HI CHC POPS APPEAR ON THE RIGHT TRACK.

EXTENDED...A DRIER NW FLOW ALF IN THE WAKE OF DEPARTING SHRTWV
SHOULD BRING MAINLY DRY WX TO THE UPR LKS ON TUE AND WED. ONLY
POTENTIAL FLY IN THE OINTMENT WOULD BE A STRONGER SHRTWV EMBEDDED IN
THIS FLOW...WHICH COMMONLY BRING SOME SHRA/TS TO THE AREA IN THE
SUMMER IF THERE IS ENUF MSTR/INSTABILITY. BUT NOTHING HIER THAN SCHC
POPS ARE WARRANTED.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 119 PM EDT THU JUN 13 2013

HIGH PRESSURE SINKING SOUTHWARD OUT OF ONTARIO WILL GRADUALLY REACH
THE GREAT LAKES LATE THIS AFTERNOON. DRY AIR HAS ALREADY BE OBSERVED
SCOURING OUT LOW CLOUDS OVER LAKE SUPERIOR. EXPECT THE SET OF MVFR
CLOUDS OVER CMX TO DISSIPATE WITHIN THE NEXT COUPLE HOURS. KSAW WILL
TAKE THE LONGEST TO CLEAR OUT...BUT SHOULD BE SKC BY 00Z TONIGHT.
GUSTY WINDS WILL ALSO DIE DOWN LATE THIS AFTERNOON AS THE LOW
PRESSURE SYSTEM TO THE SOUTHEAST MOVES TO THE EAST COAST...ALLOWING
THE PRESSURE GRADIENT TO RELAX. A QUIET DAY IS IN STORE TOMORROW AS
HIGH PRESSURE WILL BE DIRECTLY OVERHEAD...KEEPING CONDITIONS
DRY...SKIES MOSTLY CLEAR...AND WINDS LIGHT.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 443 AM EDT THU JUN 13 2013

N WINDS UP TO 15-25 KTS TODAY...HIGHEST OVER THE E PART OF THE
LAKE...UNDER A SHARPER PRES GRADIENT ON THE SOUTHERN FLANK OF
BUILDING HI PRES IN ONTARIO WILL DIMINISH TONIGHT AS THE HI MOVES
TOWARD THE AREA AND THE GRADIENT SLACKENS. THEN A RELATIVELY WEAK
PRES GRADIENT AND HI OVERWATER STABILITY WILL CAUSE WINDS UNDER 15
KTS INTO EARLY NEXT WEEK.
&&

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

$$

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