000
FXUS63 KMQT 162328
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
728 PM EDT THU MAY 16 2013

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 421 PM EDT THU MAY 16 2013

WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW TROFFING ALONG THE W COAST
OF THE CONUS...BROAD RIDGING OVER THE CNTRL CONUS...AND A TROF
EXTENDING S INTO NEW ENGLAND. AHEAD OF THE RIDGE...IT`S BEEN A
GENERALLY SUNNY DAY ACROSS THE FCST AREA. WITH THE DRY AIR NOTED ON
THE 12Z KGRB SOUNDING...DWPTS HAVE FALLEN INTO THE 20S OVER PORTIONS
OF THE INTERIOR W HALF OF UPPER MI...RESULTING IN RH DOWN AROUND
20PCT. SFC HIGH PRES ASSOCIATED WITH APPROACHING MID LEVEL RIDGE IS
SETTLING S OVER THE UPPER GREAT LAKES AND WILL LEAD TO A QUIET NIGHT
TONIGHT. TO THE W...A COUPLE OF SHORTWAVES EMERGING OVER THE WRN
HIGH PLAINS ARE GENERATING SHRA/TSRA FROM ND TO NEBRASKA. THE SRN
WAVE OVER WRN NEBRASKA IS THE STRONGER ONE. HEADING INTO LATER
FRI...FCST WILL REVOLVE AROUND WHAT AFFECTS THESE WAVES WILL HAVE
FOR UPPER MI.

AS ALLUDED TO ABOVE...SFC HIGH PRES WILL LEAD TO A TRANQUIL NIGHT
ACROSS THE FCST AREA. MAINLY CLEAR SKIES WITH PRECIPITABLE WATER
AROUND 50PCT OF NORMAL WILL LEAD TO A QUICK TEMP DROP AFTER SUNSET.
COLUMN MOISTURE BEGINS TO INCREASE OVER THE W OVERNIGHT...AND SOME
OF THAT WILL MANIFEST ITSELF AS HIGH AND MID CLOUDS SPREADING E FROM
THE SHRA AREA CURRENTLY OVER THE DAKOTAS. IN THE END...THIS SHOULD
LEAD TO LOWEST MINS OVER THE E...THOUGH SOME OF THE TRADITIONAL COLD
SPOTS OVER THE W MAY BE EQUALLY AS LOW GIVEN THE GOOD RADIATIONAL
COOLING CONDITIONS EARLY IN THE NIGHT. GENERALLY FAVORED THE LOWER
END OF GUIDANCE ACROSS THE BOARD IN THE INTERIOR. A FEW OF THE
TYPICAL COLD SPOTS MAY SLIP JUST BLO 30F.

WHETHER ANY PCPN MAKES INTO THE FCST AREA FRI IS THE BIG QUESTION.
THE NAM IS VERY AGRESSIVE WITH PCPN...BRINGING OVER AN INCH OF RAIN
TO KIWD BY 00Z SAT WITH PCPN SPREADING AS FAR E AS SENEY. THE GFS
FOLLOWS CLOSE BEHIND THE NAM...THOUGH ITS PCPN FIELD IS DISPLACED A
LITTLE FARTHER S. THE GEM HAS NO PCPN THRU 00Z SAT...THE UKMET ONLY
BRINGS A FEW HUNDREDTHS TO SCNTRL UPPER MI...AND THE 12Z ECMWF IS
SIMILAR WITH A FEW HUNDREDTHS ALONG THE WI BORDER WHICH IS FARTHER S
AND W THAN ITS 00Z RUN. SUSPECT THE STRONGER MORE WELL-DEFINED SRN
WAVE OVER THE WRN PLAINS WILL BE THE BIGGER PLAYER...RESULTING IN
PCPN WITH THE NRN WAVE OVER ND GRADUALLY DRYING UP AS IT WILL HAVE
LIMITED/NO MOISTURE INFLOW AND IT WILL BE ENCOUNTERING DRIER AIR TO
THE E. EVEN PCPN WITH THE SRN WAVE WILL PROBABLY TEND TO DIMINISH OR
AT LEAST BE SLOWER TO ARRIVE DUE TO THE DRIER AIR OVER GREAT
LAKES...ESPECIALLY SINCE LOW-LEVEL TRAJECTORIES HAVE A GOOD EASTERLY
COMPONENT FRI THAT WILL HELP TO MAINTAIN DRY AIR OVER THE AREA. SO
PLAN WILL BE TO FAVOR THE DRIER NON NCEP MODELS FOR FRI. WHILE
RELUCTANT TO ADD PCPN CHC...WILL INCLUDE A SCHC MENTION ALONG THE WI
BORDER SINCE THE THERE WAS ONLY ONE MODEL (GEM) THAT HAD A
COMPLETELY DRY FCST. FOLLOWING THE DRIER SCENARIO...ALSO UTILIZED
LOWER DWPTS FOR FRI BY COMBINING SOME OF THE BIAS CORRECTED GUIDANCE
(GEM IN PARTICULAR) WITH DWPTS CALCULATED BASED ON MIXING HEIGHT.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 421 PM EDT THU MAY 16 2013

CONFIDENCE IS STILL RATHER LOW ON QPF POTENTIAL FRIDAY NIGHT INTO
SATURDAY ASSOCIATED WITH THE DEVELOPING BAROCLINIC ZONE. AS THE
850MB LOW OVER THE CENTRAL AND NORTHERN ROCKIES MOVES EAST...STRONG
WARM ADVECTION AND ISENTROPIC LIFT WILL SPREAD ACROSS THE UPPER
MIDWEST. THE NAM IS VERY AGGRESSIVE IN DEVELOPING SIGNIFICANT
ELEVATED CONVECTION CLOSE TO THE MI/WI BORDER LATE FRI AFTN INTO
FRIDAY NIGHT...WITH OVER 2 INCHES OF QPF FORECAST AT IMT AND IWD BY
SAT AFTN. THE 12Z GFS HAS SHIFTED THE BAROCLINIC AXIS
NORTHWARD...BUT IT IS NOT AS STRONG AS THE NAM. THE 00Z ECMWF IS
OVERALL THE WEAKEST WITH THE FRONTAL BOUNDARY BUT NONETHELESS IS
SIMILAR IN POSITION BUT A LITTLE SLOWER (SIMILAR TO WHAT THE 18Z NAM
SHOWS). THE GEM IS MUCH FURTHER SOUTH. WITH ALL THAT SAID...THE
CONSENSUS OF DETERMINISTIC AND ENSEMBLE NWP SUGGEST THAT POPS WILL
NEED TO BE RAISED ACROSS THE ENTIRE AREA (EXCEPT EAST 1/3) FRIDAY
NIGHT INTO SATURDAY. WITH THE STRONGLY CONFLUENT FLOW AND DRY AIR IN
PLACE...DO NOT EXPECT THE HEAVY PCPN PER THE NAM FORECAST...HOWEVER
SOME SHOWER ACTIVITY FRIDAY NIGHT INTO SATURDAY IS EXPECTED
ESPECIALLY CLOSER TO THE WI BORDER WHERE THE BETTER MOISTURE AND
BETTER LIFT ASSOCIATED WITH THE FRONTAL ZONE IS LOCATED.

BY SATURDAY AFTERNOON...THE BAROCLINIC ZONE SHIFTS NORTH OF THE AREA
WITH THE BEST MOISTURE TRANSPORT CLOSER TO THE LOW TO THE WEST OF
THE AREA. IN FACT...WILL LIKELY SEE SOME CLEARING LATE SAT AFTN AS
THE WARM SECTOR MOVES OVER THE AREA AND DRIER AIR ADVECTS INTO THE
AREA. WILL MAINTAIN LOW CHANCE POPS WEST SAT AFTN/NIGHT...BUT
GENERALLY DRY ELSEWHERE.

SUNDAY SHOULD END UP BEING GENERALLY DRY WITH THE BEST MOISTURE AND
LOW LVL JET TO THE WEST OF THE AREA. NAM AND GFS ARE VERY AGGRESSIVE
IN WARMING 850MB TEMPS TO +18C ACROSS THE SOUTH...BUT AM THINKING
THE MORE CONSERVATIVE ECMWF WITH 850MB TEMPS AROUND +14 SEEMS MORE
REASONABLE. REGARDLESS...SHOULD BE A NICE DAY WITH PERHAPS A CHANCE
OF SHOWERS AND THUNDERSTORMS LATE IN THE DAY SUNDAY ACROSS THE WEST.

RATHER UNSETTLED WEATHER WILL CONTINUE THROUGH THE EARLY PART OF
NEXT WEEK WITH THE UPPER LOW OVER THE NORTHERN PLAINS BEING RATHER
STUBBORN TO MOVE OUT. THIS WILL KEEP THE BAROCLINIC ZONE NEARBY
THROUGH WEDNESDAY BEFORE AN UPPER TROUGH OVER HUDSON BAY DIVES SOUTH
AND ALLOWS THE FRONT TO MOVE SOUTH OF THE AREA BY THURSDAY. WITH
THAT SAID...MON-WED LOOKS QUITE WET AT TIMES WITH SOME HEAVY RAIN
CERTAINLY POSSIBLE. ALTHOUGH 850MB TEMPS WILL BE AROUND +10C THROUGH
WED...EASTERLY FLOW DUE TO THE LOW STAYING SOUTH OF THE AREA AS WELL
AS PLENTIFUL CLOUDS WILL KEEP TEMPS COOL NEAR LAKE SUPERIOR. INLAND
TEMPS WILL LIKELY STAY NEAR NORMAL...BUT TEMPS CLOSER TO LAKE
SUPERIOR WILL BE IN THE UPPER 50S.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 726 PM EDT THU MAY 16 2013

ALTHOUGH SOME HI CLDS WL BE ON THE INCREASE...EXPECT VFR CONDITIONS
TO PREVAIL THRU THIS FCST PERIOD WITH DRY E WIND OUT OF HUDSON BAY
HI PRES.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 421 PM EDT THU MAY 16 2013

LIGHT WINDS WILL BE THE RULE ACROSS LAKE SUPERIOR TONIGHT WITH HIGH
PRES OVER THE UPPER LAKES. WHILE THE HIGH WILL BE SHIFTING E FRI...A
MESO HIGH MAY LINGER OVER ERN LAKE SUPERIOR THRU THE DAY. THIS WILL
KEEP WINDS LIGHT OVER THE E...BUT E TO NE WINDS WILL BEGIN TO
INCREASE OVER THE W. HEADING THRU THE WEEKEND INTO EARLY NEXT
WEEK...PRES 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.
&&

$$

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