Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 262002
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
402 PM EDT SUN OCT 26 2014

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 402 PM EDT SUN OCT 26 2014

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER
CENTRAL NAMERICA BLDG TOWARD THE WRN GREAT LKS BTWN SLOWLY DEPARTING
CLOSED LO OVER SE CANADA AND ANOTHER DEEP TROF OVER THE W. AT THE
SFC...HI PRES RDG AXIS AND DRY AIRMASS SHOWN ON THE 12Z INL/MPX
RAOBS...WHERE 12Z PWAT WAS 0.25-0.30 INCH...ARE PRESSING EWD THRU
THE UPR LKS...BRINGING MOSUNNY SKIES TO UPR MI. SOME SC LINGERS OVER
THE FAR E UNDER LLVL NW FLOW/THERMAL TROF AHEAD OF THE RDG AXIS...
AND SOME CI SPILLING OVER THE UPR RDG AXIS TO THE NE OF H85 WARM FNT
IN THE NRN PLAINS IS MOVING INTO THE W. DEEPENING SFC LO PRES IS
MOVING SLOWLY E THRU THE NRN PLAINS IN ADVANCE OF THE WRN TROF...BUT
OVERALL DRYNESS OF THE AIRMASS IN THE NRN PLAINS HAS PREVENTED ANY
PCPN AND EVEN MUCH CLD COVER SO FAR. 12Z H85 TEMPS WERE AOA 20C IN
THE NCENTRAL PLAINS IN THE WARM SECTOR OF THIS LO.

MAIN FCST CONCERNS IN THE SHORT TERM FOCUSED ON CLD/PCPN TRENDS
ASSOCIATED WITH APRCHG WARM FNT.

TNGT WL START OFF MAINLY CLEAR WITH JUST SOME SCT HI CLDS...BUT THEN
CLDS WL THICKEN THRU THE NGT WITH DVLPG WAD BTWN HI PRES RDG
DEPARTING TO THE E AND LO PRES MOVING TOWARD LK WINNIPEG AND NE OF
ATTENDANT WARM FNT MOVING NE THRU WI. ALTHOUGH LINGERING LLVL DRY
AIR AND PASSAGE OF SHARPER H85-5 QVECTOR CNVGC TO THE NW MAY TEND TO
LIMIT POPS...FCST DEEP ISENTROPIC ASCENT WITH VIGOROUS H85-5
MOISTENING LIFTING PWAT TOWARD ARND AN INCH OR 225 PCT OF NORMAL
OVER THE W BY 12Z MON...BAND OF FCST H85-7 FGEN TO THE NE OF THE H85
WARM FNT AND INCRSG UPR DVGC JUSTIFY BUMPING POPS UP A BIT OVER THE
W HALF LATE. BUT OVERALL INITIAL DRYNESS OF THE AIRMASS WARRANTS A
FCST OF NO HIER THAN HI CHC POPS. MAINTAINED MENTION OF SOME THUNDER
OVER THE W LATER AT NGT...WHEN MID LVL LAPSE RATES ARE FCST TO
STEEPEN AND FCST SDNGS INDICATE MUCAPE UP TO 500 J/KG. THE STEEPER
MID LVL LAPSE RATES FCST ARE REASONABLE GIVEN THE VERY HI H85 TEMPS
OBSVD IN THE PLAINS TODAY. DESPITE THE EXPECTED INCRSG CLDS/MSTR...
DRYNESS OF THE AIRMASS IN PLACE SUGGESTS LOWERING FCST LO TEMPS A
BIT. EXPECT THE LOWEST MIN TEMPS TOWARD THE LO END OF GUIDANCE OVER
THE INTERIOR E...WHERE CLDS WL INCRS LATEST. HOURLY TEMPS FCST WL
SHOW RELATIVELY EARLY MINS WITH RISING READINGS LATER TNGT UNDER THE
INCRSG/THICKENING CLDS.

MON...INCRSD POPS TO LIKELY ON MON MRNG OVER THE E HALF WHERE MODELS
SHOW INCRSG UPR DVGC/BAND OF H85-7 FGEN AND ISENTROPIC ASCENT
COINCIDENT WITH INCRSG PWAT UP TO ABOUT 215 PCT OF NORMAL. MODEL
FCST SDNGS INDICATE MUCAPE 500-1000 J/KG WHEN LIFTING FM ARND H8 ON
MON. GIVEN THE MAGNITUDE OF THIS ELEVATED INSTABILITY...NOT OUT OF
THE QUESTION THERE COULD BE SOME HAIL UNDER ANY STRONGER STORM.
ARRIVAL OF DEEP LYR QVECTOR DVGC/MID LVL DRYING AND CAPPING W-E IN
THE AFTN FOLLOWING EXIT OF THE UPR DVGC/FGEN BAND WL DIMINISH THE
POPS. TENDED TOWARD THE LO END OF GUIDANCE FOR MAX TEMPS ON MON
GIVEN HI SFC-H85 STABILITY/CLDS N OF SFC WARM FNT. ADDED A MENTION
OF SOME FOG LATE IN THE DAY OVER THE CENTRAL WITH INCRSGLY MOIST
UPSLOPE LLVL SE FLOW UNDER MID LVL DRYING IN ADVANCE OF SLOWLY
APRCHG WARM FNT.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 326 PM EDT SUN OCT 26 2014

THE FORECAST FOR MON NIGHT/TUE REMAINS SOMEWHAT UNCERTAIN DUE TO
MODEL DISAGREEMENT WITH SHORTWAVE ENERGY /AND RESULTING
CYCLOGENESIS/ ROTATING AROUND AN UPPER TROUGH MOVING THROUGH THE
REGION. THE REAL DIFFERENCES ARE DUE TO THE PLACEMENT OF THE
SHORTWAVE. THE GFS KEEPS THE BEST ENERGY FARTHER N...RESULTING IN
THE DRY SLOT BEING OVER THE CWA MUCH OF MON NIGHT AND TUE. ON THE
OTHER HAND...THE NAM IS MUCH FARTHER S...RESULTING IN A DEEPER SFC
LOW THAT MOVES FROM CENTRAL LAKE MICHIGAN TO ERN UPPER MI...WHICH
MEAN MORE RAIN. THE ECMWF IS BETWEEN THE NAM AND GFS AND ONLY BRINGS
THE DRY SLOT INTO FAR SRN PORTIONS OF THE CWA...RESULTING IN A
WETTER FORECAST THAN THE GFS. VERY DIFFICULT TO LEAN TOO FAR ONE WAY
OR ANOTHER AT THIS POINT GIVEN UNCERTAINTIES WITH SHORTWAVE ENERGY
AND SFC CYCLOGENESIS...SO WILL GO WITH A CONSENSUS BLEND.
ADDITIONALLY...TUE WILL END UP BEING GUSTY...BUT THE EXTENT OF SUCH
DEPENDS LARGELY ON THE TRACK/STRENGTH OF THE SFC LOW...SO HARD TO
GET TOO SPECIFIC ON EXPECTED GUSTS AT THIS POINT. THE KEWEENAW
SHOULD SEE THE STRONGEST WINDS OVER UPPER MI DUE TO THE FAVORABLE
WLY WINDS DIRECTION.

TUE NIGHT INTO THU NIGHT...THE SYSTEM THAT MOVED THROUGH ON TUE WILL
MOVE INTO NRN QUEBEC BY LATE WED AS A SFC RIDGE MOVES TO THE WRN
CWA. FORECAST CONFIDENCE IMPROVES DURING THIS TIME AS CONDITIONS
TRANSITION TO A MORE FAVORABLE LAKE EFFECT/ENHANCED RAIN/SNOW
SETUP...WHICH ENTAILS LESS MODEL VARIABILITY IN THIS CASE. BOUNDARY
LAYER WINDS WILL BE FROM THE NW...BUT WILL START TO BACK TO THE W
/FROM W TO E/ ON WED AFTERNOON AS THE RIDGE MOVES IN. THERE WILL BE
AMPLE LOW LEVEL MOISTURE WRAPPING AROUND THE BACK SIDE OF THE
PREVIOUS SYSTEM INTO WED MORNING...BUT DRIER AIR WILL START TO
BECOME MORE DOMINANT ON WED. AS FOR TEMPS...850MB TEMPS WILL FALL
FROM AROUND -2C AT 00Z WED TO AROUND -6C AT 12Z WED. DURING THE DAY
ON WED...850MB TEMPS WILL FALL A COUPLE OF DEGREES OVER ERN LAKE
SUPERIOR WHILE WARMING A COUPLE OF DEGREES OVER THE WRN LAKE.
OVERALL...LOOKS LIKE A GOOD SETUP FOR LAKE EFFECT RAIN...WITH SNOW
BECOMING MORE LIKELY IN OVER THE HIGHER TERRAIN LATE TUE NIGHT AND
TO A LESSER EXTENT ON WED. SHOULD SEE A DIMINISHING TREND TO PRECIP
ON WED...ESPECIALLY OVER THE WRN CWA. DO NOT EXPECT TO SEE ANY
SIGNIFICANT SNOW ACCUMULATIONS.

STILL A LOT OF UNCERTAINTY FOR LATE IN THE WEEK GIVEN POOR MODEL RUN
TO RUN CONTINUITY AND MODEL DISAGREEMENT...COMBINED WITH THE USUAL
CAVEATS WITH SHORTWAVES 5 DAYS OUT. THE GFS BRINGS THE SHORTWAVE
RIGHT ACROSS THE CWA...WHILE THE ECMWF MOVES THE SHORTWAVE FARTHER
SW. IN ANY CASE...MODELS HAVE SHOWN POOR RUN TO RUN CONTINUITY WITH
THE SHORTWAVE ITSELF...SO SYNOPTIC PRECIP IS HIGHLY UNCERTAIN.
THANKFULLY...THERE IS HIGHER CONFIDENCE WITH LAKE EFFECT SNOW DUE TO
MODEL AGREEMENT ON NNW LOW LEVEL WINDS AND 850MB TEMPS AOB -10C FOR
MUCH OF FRI AND POSSIBLY INTO FRI NIGHT. THE LES SHOULD RAMP UP THU
NIGHT WHEN THE COLDER AIR SURGES INTO THE AREA /DEPENDENT ON
SHORTWAVE TIMING AS WELL/ AND SHOULD DIMINISH FRI NIGHT INTO SAT AS
A SFC RIDGE MAY SHIFT ACROSS THE CWA. COULD SEE SOME LIGHT
ACCUMULATIONS IN NNW WIND SNOWBELTS EVEN IF THE SHORTWAVE DOES NOT
DIRECTLY IMPACT THE CWA...BUT WOULD BE GREATER IF THE SHORTWAVE DOES
IMPACT THE AREA. SHOULD ALSO BE WINDY FOR AT LEAST A SHORT PERIOD
THU NIGHT INTO FRI /DEPENDING ON THE TRACK AND STRENGTH OF THE
SHORTWAVE/ AS A 1030MB SFC HIGH MOVES FROM THE WNW FAIRLY QUICKLY
BEHIND THE SHORTWAVE. SHOULD SEE A QUICK PERIOD OF GALES FROM THE
EVENT...BUT WILL HAVE TO WAIT UNTIL THINGS BECOME MORE CERTAIN TO
GET TOO SPECIFIC ON WINDS SPEEDS.

SHOULD SEE ANY REMAINING LAKE EFFECT PRECIP DIE OUT/MOVE OUT ON SAT
AS MODELS SHOW THE SFC HIGH SHIFT E OF THE CWA. WILL RUN WITH A
CONSENSUS OF GUIDANCE FOR SAT NIGHT INTO SUN...WHICH WILL SHOW A
WARMING TREND AS AN UPPER RIDGE PUSHES IN FROM THE W.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 121 PM EDT SUN OCT 26 2014

ALTHOUGH HIER CLDS WL BE ON THE INCRS LATER THIS AFTN/THIS EVNG IN
ADVANCE OF AN APRCHG WARM FNT...EXPECT VFR CONDITIONS TO PREVAIL
WITH DRYNESS OF LLVL AIRMASS SHOWN ON LOCAL 12Z RAOBS. BUT AS THE
INCRSG SSE WIND AHEAD OF THE WARM FNT DRAWS MORE MSTR INTO THE UPR
LKS...SOME -SHRA WL DVLP LATE TNGT. CLD BASES WL LOWER...BUT
LINGERING NEAR SFC DRY LYR SHOULD MAINTAIN A VFR CIG. RETAINED
MENTION OF MARGINAL LLWS AT IWD WITH CLOSER APRCH OF THE WARM
FNT/INVRN AND EXPECTED STRONGER LLJ AT THAT LOCATION. AFTER 12Z
MON...THE LLVLS WL MOISTEN SUFFICIENTLY TO WARRANT FCST MVFR CIGS.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 326 PM EDT SUN OCT 26 2014

HIGH PRESSURE MOVING INTO THE REGION WILL LEAD TO DECREASING WINDS
TODAY. AFTER A BRIEF PERIOD WITH WINDS LESS THAN 20 KTS WITH THE
HIGH PRESSURE...SE WINDS INCREASE TO 30 KTS OVER MAINLY EASTERN LAKE
SUPERIOR ON MONDAY AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM. ONCE
THIS LOW MOVES TO THE EAST OF LAKE SUPERIOR ON TUESDAY...WEST WINDS
TO 30 KTS AND POSSIBLY UP TO GALE FORCE OF 35 KTS WILL DEVELOP LATE
TUESDAY INTO TUESDAY NIGHT. WINDS WILL THEN SHIFT NORTHWEST AND STAY
UP TO 30 KTS INTO WEDNESDAY...BEFORE GRADUALLY DIMINISHING TO LESS
THAN 25 KTS BY WEDNESDAY NIGHT. ANOTHER LOW PRESSURE SYSTEM MAY MOVE
THROUGH THE REGION LATE THIS WEEK...POSSIBLY LEADING TO GALES TO 35
KTS.
&&

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

$$

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




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