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000
FXUS63 KMQT 172329
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
729 PM EDT FRI MAY 17 2013

.UPDATE...
ISSUED AT 728 PM EDT FRI MAY 17 2013

LATEST MODELS HAVE TRENDED DRIER FOR THE OVERNGT FCST FOR UPR MI...
SHOWING MORE IMPRESSIVE H85 MOISTENING ASSOCIATED WITH ADVANCING
WARM FNT FOCUSED W OF UPR MI. GIVEN ESE FLOW OUT OF STUBBORN HUDSON
BAY HI PRES/DRY AIRMASS SHOWN ON THE 12Z APX RAOB...TRIMMED POPS
ACCORDINGLY. ALSO REMOVED MENTION OF TS TNGT AS 18Z NAM SHOWS MUCAPE
THRU 12Z SAT NO HIER THAN 5-50 J/KG.
&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 447 PM EDT FRI MAY 17 2013

TRICKY PRECIP FORECAST IN THE SHORT TERM. CURRENTLY...THE CWA SITS
BETWEEN AN UPPER RIDGE OVER MN INTO CENTRAL CANADA AND AN UPPER LOW
OVER ERN QUEBEC. AT THE SFC...A HIGH IS OVER THE NE CWA WITH
DEVELOPING LOW PRESSURE OVER THE WRN PLAIN STATES. DRY AIR
ASSOCIATED WITH THE SFC HIGH HAS HELPED KEEP PRECIP/CLOUDS MOSTLY
S/SW OF THE CWA THIS AFTERNOON...BUT A LARGE ARE OF PRECIP IS
LOCATED N OF A WARM FRONT IN AN AREA OF MOISTURE ADVECTION OVER
CENTRAL WI. THE WARM FROM EXTENDS FROM SRN MN /WHERE CONVECTION HAS
DEVELOPED/ TO NRN IL...WHERE PRECIP IS ALSO BEING SEEN.

THE SFC HIGH SHIFTS SLIGHTLY E OVERNIGHT AS A SFC LOW DEEPENS OVER
THE WRN PLAINS...ALLOWING SLY FLOW TO INCREASE OVER THE CWA...BUT
DRY AIR TO KEEP A GRIP ON THE NERN CWA. THE WARM FRONT WILL MOVE N
INTO THE SW CWA AROUND 03Z SAT...FINALLY MOVING TO THE NE CWA BY 00Z
SUN. MODELS ARE ALL OVER THE PLACE WITH QPF LIKELY DUE TO CONVECTIVE
FEEDBACK...AND MANY DO NOT EVEN INITIALIZE WELL WITH QPF. SO
POPS/QPF/WEATHER ARE PRETTY UNCERTAIN LATER THIS EVENING INTO
SAT...BUT THERE ARE SOME THINGS WITH THE PRECIP THAT DO APPEAR MORE
CERTAIN. THE BEST MOISTURE ADVECTION/INSTABILITY WILL BE OVER THE
FAR WRN CWA CLOSER TO THE SFC LOW AND STRONGER SLY FLOW/LOW LEVEL
JET. KEPT HIGHEST POPS OVER THE W...WITH CHANCE POPS OVER THE
CENTRAL AND E CWA...AND ONLY SLIGHT CHANCE POPS OVER THE ERN CWA.
ANOTHER COMPLICATING FACTOR FOR PRECIP TONIGHT IS THE QUESTION ABOUT
CONVECTION DEVELOPING TO OUR S AND CUTTING OFF MOISTURE FLOW. THIS
MAY ACT TO FURTHER REDUCE PRECIP CHANCES...ESPECIALLY OVER THE
CENTRAL AND ERN CWA. EVEN WITH INCREASING LOW LEVEL TEMPS TONIGHT
INTO SAT...HIGHS ON SAT SHOULD NOT BE ALL THAT MUCH HIGHER THAN
TODAY IN MOST LOCATIONS DUE TO INCREASED CLOUD COVER SAT.

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 447 PM EDT FRI MAY 17 2013

SAT NIGHT AND SUNDAY...MODELS SUGGEST THAT MID/UPPER LEVEL RIDGING
WILL PREVAIL DOWNSTREAM FROM THE TROUGH DIGGING INTO THE PLAINS.
EXPECT THAT THE AREA WILL REMAIN MAINLY DRY AS THE MOISTURE AXIS
REMAINS WEST OF THE CWA AND THE THE FOCUS FOR STRONGER ISENTROPIC
LIFT WITH THE 850-700 MB FRONT REMAINS WELL TO THE NORTH. POPS
CLIMB SLIGHTLY SUNDAY AFTERNOON OVER THE WEST AS THE TROUGH SHIFTS
TO THE EAST AND THE POTENTIAL FOR WEAK SHRTWVS LIFTING TOWARD THE
REGION INCREASES. MUCAPE VALUES TO NEAR 1K J/KG WILL ALSO SUPPORT
POTENTIAL FOR TSRA.

SUN NIGHT INTO MON...THE ECMWF/GFS/GEM WERE IN GOOD AGREEMENT WITH
THE POSITION OF THE DEVELOPING CLOSE MID LEVEL LOW AND SFC LOW FROM
ERN NEBRASKA TO THE SW CORNER OF MN. THIS WILL ALLOW ENOUGH GULF
MOISTURE INFLOW TO PUSH PWAT VALUES TO NEAR 1.5 INCHES (NEAR 200 PCT
OF NORMAL). THE ABUNDANT MOISTURE ALONG WITH INCREASING FORCING FOR
ASCENT WITH UPPER LEVEL DIV AND 700-300 MB QVECTOR CONV AHEAD OF THE
LOW WILL SUPPORT LIKELY POPS SPREADING INTO THE CWA SUNDAY NIGHT AND
LINGERING THROUGH MONDAY. SCT TSRA ARE ALSO EXPECTED WITH THE
MAINLY ELEVATED CONVECTION NORTH OF THE SFC WARM FRONT MOVING TOWARD
NRN WI.

TUE-FRI...UNCERTAINTY INCREASES AS MODEL SHOW LARGER DIFFERENCES IN
HANDLING THE THE SLOW MOVING MID LEVEL LOW/TROUGH. THE 12Z ECMWF AND GEM
SUGGEST THAT THE LOW WILL ONLY SLOWLY WEAKEN AND SLIDE TO THE
EAST...KEEPING PCPN CHANCES IN THE AREA THROUGH THU WHILE THE 12Z
GFS AND 00Z ECMWF PUSH THE TROUGH AND FRONT TO THE SOUTH AS
STRENGTHENING NRN STREAM FLOW DEVELOPS FROM NRN ONTARIO INTO THE NRN
LAKES.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 728 PM EDT FRI MAY 17 2013

EXPECT VFR CONDITIONS/DRY WX TO PERSIST THRU THIS EVNG. BUT AS A
WARM FNT MOVES IN FM THE S...SOME -SHRA/MVFR CIGS WL BE PSBL...
MAINLY AT CMX/IWD WHERE LLVL WARM/MOIST ADVCTN WL BE MOST
PRONOUNCED. FOLLOWING THE WARM FROPA SAT MRNG...EXPECT WSHFT TO THE
S AND A RETURN TO PREDOMINANT VFR WX WITH DAYTIME HEATING/MIXING.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 PM EDT FRI MAY 17 2013

HEADING THRU THE WEEKEND INTO EARLY NEXT WEEK...PRESSURE GRADIENT
OVER THE UPPER LAKES WILL SLOWLY TIGHTEN BTWN LOW PRES SLOWLY MOVING
FROM THE WRN PLAINS TOWARD THE UPPER MISSISSIPPI VALLEY AND HIGH
PRES BUILDING IN THE VCNTY OF WRN HUDSON BAY. THIS WILL LEAD TO
EASTERLY WINDS GRADUALLY INCREASING INTO GENERALLY THE 15-25KT
RANGE. COULD BE SOME PERIODS OF HIGHER WINDS AT TIMES EARLY NEXT
WEEK...ESPECIALLY OVER WRN LAKE SUPERIOR WHERE FUNNELING/CHANNELING
WILL ENHANCE THE WINDS.
&&

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

$$

UPDATE...KC
SHORT TERM...TITUS
LONG TERM...JLB
AVIATION...KC
MARINE...TITUS