Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KMQT 231728
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
128 PM EDT WED APR 23 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 456 AM EDT WED APR 23 2014

THE SHORT TERM PERIOD WILL BE MARKED BY MAINLY DRY AND SLIGHTLY
WARMER CONDITIONS AS AS HIGH CLOUDS SLOWLY STREAM IN FROM THE
W...AHEAD OF THE APPROACHING LATE SEASON WINTER WX EVENT.

FOR TODAY TEMPERATURES SHOULD END UP TOPPING OUT AROUND 10F WARMER
THAN YESTERDAY THANKS TO ONLY A FEW CLOUDS AND MUCH WARMER AIR
SLIDING IN. THAT WILL MEAN TEMPS NEARING NORMAL FOR THIS TIME OF
YEAR. 850MB TEMPS AVERAGING -7C AT 00Z WEDNESDAY WILL WARM TO AN
AVERAGE -1C BY 00Z THURSDAY. THE SFC HIGH WILL SLOWLY EXIT E THIS
AFTERNOON...BUT SHOULD STILL ALLOW FOR LIGHT ENOUGH WINDS FOR LAKE
BREEZES TO DEVELOP OVER THE E HALF OF THE CWA. OTHERWISE...DEW
POINTS COULD MIX DOWN TO SEE RH VALUES FALLING 20-25 PERCENT NEAR
THE WI BORDER. CURRENTLY HAVE ABOUT 5 PERCENT HIGHER FCST.

ESE DOWNSLOPE WINDS OVER THE FAR W AND PLENTY OF CLOUD COVER SHOULD
KEEP SFC TEMPS FROM FALLING BELOW FREEZING OVERNIGHT. OTHERWISE
CENTRAL AND E ARE A BIT TRICKIER...WITH MAINLY HIGH CLOUDS AND MUCH
LIGHTER WINDS. MID 20S STILL LOOK REASONABLE FOR LUCE COUNTY. THE
SLOWING TREND OF INCOMING WAA PRECIP CONTINUES...WITH A MIX OF RAIN
AND SNOW PUSHING INTO GOGEBIC COUNTY JUST PRIOR TO 12Z THURSDAY AS
THE APEX OF THE 500MB RIDGE SLIDES OVERHEAD.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 441 AM EDT WED APR 23 2014

MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON THE POTENTIAL FOR HEAVY
PCPN ON THU INTO EARLY FRI AS WELL AS PTYPE.

AT 12Z THU...THE STRONGER NRN SHRTWV WL BE LOCATED NEAR THE CNDN
BORDER WITH MONTANA WHILE THE SRN DISTUBANCE SHIFTS E INTO THE
CENTRAL PLAINS... WITH ACCOMPANYING SFC LO PRES CENTERS NEARBY.
DESPITE THE SEPARATION BTWN THE INDIVIDUAL SHRTWVS...MODEL FCST RH
FIELDS SHOW WARM CONVEYOR BELT AREA OF HIER RH EXTENDING FM MN INTO
THE UPR LKS UNDER OVERAL SE FLOW TO THE E OF LARGER SCALE LO PRES
TROF IN THE PLAINS. H7 SPECIFIC HUMIDITY WITHIN THIS BAND AT THE
LATITUDE OF UPR MI IS FCST TO BE ABOUT 4 G/KG...BOOSTED BY H85 S
WINDS FCST UP TO 35-50 KTS E OF THE LARGER SCALE TROF AXIS. SO EVEN
THOUGH THE MODELS CONTINUE TO SHOW THE SRN SHRTWV WL REMAIN OUT OF
PHASE WITH THE NRN DISTURBANCE AND THAT ONLY THE STRONGER NRN SHRTWV
WL IMPACT THE CWA AS THESE DISTURBANCES MOVE TO THE E THRU FRI...
THERE WL BE ADEQUATE MSTR AVBL FOR POTENTIALLY HEAVY PCPN OVER UPR
MI AS THESE INDIVIDUAL DISTURBANCES MOVE INTO THE OHIO RIVER VALLEY
AND INTO THE UPR LKS RESPECTIVELY BY 12Z FRI. DIFFLUENT H3
FLOW/SHARP H4-2 DVGC E OF THE ARPCHG NRN SHRTWV WL ALSO ACT TO
ENHANCE PCPN RATES OVER THE CWA.

THE 00Z GFS/NAM INDICATE THE NRN SHRTWV WL TRACK THRU CENTRAL UPR
MI...WITH THE HEAVIEST PCPN MOST LIKELY TO THE N OF THE H85-7-5 LO
TRACK FM ABOUT IRONWOOD/ONTONAGON TO MARQUETTE BEFORE THE PCPN
SLOWLY DIMNISHES ON FRI WITH THE ARRIVAL OF DNVA/LARGER SCALE
QVECTOR DVGC IN THE WAKE OF THE DEPARTING SHRTWV INTO SE ONTARIO.
BUT THE 00Z UKMET AND THE 22/12Z AND 23/00Z ECMWF SHOW A FARTHER N
TRACK FOR THE NRN SHRTWV AND H85-7 LO ACRS THE NRN KEWEENAW...WITH
EARLIER DRY SLOTTING BY 06Z-12Z FRI AND A SHORTER WINDOW FOR HEAVIER
PCPN. THE 00Z CNDN MODEL IS A COMPROMISE BTWN THESE TWO CAMPS...BUT
SEEMS MORE ALIGNED WITH THE NCEP MODELS. 24 HR PCPN TOTALS THRU 12Z
FRI SHOWN BY THE NCEP MODELS RANGE FM 0.65-1.10 INCH...LEAST OVER
THE SE AND GREATEST OVER THE KEWEENAW ON THE CYC SIDE OF THE UPR LO
FCST TRACK. IN CONTRAST...THE 22/12Z ECWMF SHOWED 24 HR PCPN RANGING
FM 0.50 INCH OVER THE SE TO 0.75 INCH OVER THE KEWEENAW.

A MAJOR CONCERN THIS LATE IN THE SEASON IS ON PTYPE AND HOW SFC
TEMPS WL IMPACT SN ACCUM RATES. MODELS SHOW PCPN ARRIVING W-E ON
THU...REACHING NEWBERRY BY LATE IN THE AFTN. SINCE THE PCPN WL BE
ARRIVING DURING DAYTIME HEATING...WHEN H100-85 THKNS ARE FCST IN THE
1305-1310M RANGE...SUSPECT THE PCPN WL START AS RA OR A RA/SN MIX
OVER THE HIER TERRAIN WITH SOME EVAPORATIVE COOLING IN THE INITALLY
DRY LLVL AIR. EVEN WHERE SN IS MIXED IN WITH THE PCPN...EXPECT LTL
IF ANY SN ACCUMULATION ON WARMER SFCS LIKE ROADS. LOSS OF DAYTIME
HEATING/DYNAMIC COOLING WL ALLOW THE PCPN TO CHG TO PRIMARILY SN BY
00Z FRI AS H100-85 THKNS FALL TO 1295-1305M...ESPECIALLY AT
LOCATIONS TO THE N OF THE H85 LO TRACK. IN ADDITION TO THE WARM NEAR
SFC TEMPS...A HI AND THIN DGZ WL ALSO REDUCE SN/WATER RATIOS AND
MAKE THIS SN PARTICULARLY WET AND HEAVY. BEST BET ATTM IS FOR SN
TOTALS TO REACH 6 TO PERHAPS 8 INCHES OVER THE HIER TERRAIN OF THE
KEWEENAW GIVEN THE MORE FVRBL LOCATION RELATIVE TO THE H85-7 LO
TRACK. OTHER HIER TERRAIN LOCATIONS OVER THE NW HALF OF THE CWA MAY
SEE 2 TO 5 INCHES. THE FCST H85-7 LO TRACK ARGUES FOR MAINLY RA AND
LTL SN ACCUM OVER THE SE PORTION OF UPR MI.

SUSPECT FUTURE SHIFTS WL NEED TO ISSUE WINTER WX ADVYS FOR THE HIER
TERRAIN OF NW UPR MI. GIVEN THE GREAT UNCERTAINTY ON SHRTWV LO TRACKS
AND THE IMPACT OF TEMPS ON SN ACCUM RATES FOR A MAINLY 4TH PERIOD SN
FALL...OPTED TO UPDATE GOING SPECIAL WEATHER STATEMENT.

FRI NGT...ANOTHER SHRTWV DIVING ESEWD INTO THE UPR LKS BEHIND
DEPARTING SHRTWV MAY BRING SOME LGT SN/RA TO THE CWA. THE 00Z CNDN
MODEL IS STRONGEST WITH THIS DISTURBANCE AND GENERATES ANOTERH 0.50
INCH OF PCPN NEAR THE WI BORDER...BUT THIS STRONGER/WETTER SCENARIO
SEEMS UNREASONABLE GIVEN THE LARGER SCALE HGT RISES/DRYING THAT
WOULD BE EXPECTED OVER UPR MI IN THE WAKE OF THE DEPARTING INITIAL
STRONGER NRN SHRTWV.

EXTENDED...THE NW FLOW ALF E OF UPR RDG BLDG IN THE PLAINS IN THE
WAKE OF THE DEPARTING LO PRES AND TO THE S OF SPRAWLING HI PRES OVER
SCENTRAL CANADA ARE FCST TO PUSH DRIER AIR INTO THE UPR LKS STARTING
ON SAT. SOME OF THE LONGER RANGE MODELS SHOW NEXT SHRTWV LIFTING NE
OUT OF THE PLAINS BRINGING A RETURN OF PCPN AS EARLY AS SUN
NGTCONSIDERING THIS HUDSON BAY HI AND THE LIKELY DRY NNE FEED OF DRY
AIR THAT WL IMPACT THE AREA/CLIMATOLOGY OF HUDSON BAY HI PRES
SYSTEMS IN SPRING...OPTED TO CUT MODEL CONSENSUS POPS AND KEEP THE
FCST DRY THRU MON. TEMPS WL AVG BLO NORMAL DURING THIS TIME.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 126 PM EDT WED APR 23 2014

A VERY DRY AIR MASS IS ASSOCIATED WITH SFC HIGH PRES CURRENTLY OVER
THE WRN GREAT LAKES. THIS VERY DRY AIR MASS WILL LINGER AT THE LOW
LEVELS THRU TONIGHT...ENSURING VFR CONDITIONS CONTINUE AT
KIWD/KCMX/KSAW. OTHERWISE...THERE WILL BE INCREASING HIGH CLOUDS
THIS AFTERNOON THRU THIS EVENING THEN INCREASING MID CLOUDS LATER
TONIGHT THRU THU MORNING AS THE NEXT LOW PRES SYSTEM APPROACHES. RAIN
OR MIX OF RAIN AND SNOW WILL PROBABLY REACH KIWD EARLY THU
MORNING...THOUGH THERE IS UNCERTAINTY IN TIMING AS LINGERING
LOW-LEVEL DRY AIR MASS WILL WORK TO SLOW E/NE PROGRESSION OF PCPN.
BY LATE MORNING...PCPN IS LIKELY AT KIWD ALONG WITH MVFR CONDITIONS.
PCPN (SNOW OR SNOW/RAIN) SHOULD BE CLOSE TO KCMX/KSAW BY 18Z AND WILL
CERTAINLY BEGAN SHORTLY AFTER THIS FCST PERIOD.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 439 AM EDT WED APR 23 2014

HIGH PRESSURE ACROSS THE UPPER GREAT LAKES WILL SHIFT E TO CANADA
AND THE LOWER GREAT LAKES ON THURSDAY. THIS WILL MAKE WAY FOR THE
LOW STRETCHING FROM SOUTHERN SASKATCHEWAN TO IA AROUND DAYBREAK
THURSDAY TO PUSH ACROSS THE UPPER GREAT LAKES THURSDAY NIGHT THROUGH
FRIDAY...BEFORE EXITING ACROSS LAKE HURON LATE FRIDAY AFTERNOON.
LOOK FOR A MIX OF RAIN AND SNOW OVER THE W HALF OF LAKE SUPERIOR BY
MID MORNING THURSDAY...BEFORE EXPANDING ACROSS THE REMAINDER OF THE
LAKE BY THE END OF THE DAY. PERIODS OF MODERATE SNOW MAY BE POSSIBLE
OVER MAINLY W LAKE SUPERIOR THURSDAY EVENING...AND ACROSS CENTRAL
AND E AREAS OVERNIGHT AS E WINDS GUSTS INTO THE 20-30KT RANGE. A FEW
GALES MAY STILL BE POSSIBLE...SO STAY TUNED TO LATER FCSTS.

LARGE HIGH PRESSURE OVER CENTRAL CANADA ON FRIDAY WILL PUSH ACROSS
HUDSON BAY SATURDAY...WHERE IT WILL REMAIN THROUGH SUNDAY. EXPECT A
RIDGE EXTENDING SOUTHWARD ACROSS LAKE SUPERIOR FRIDAY NIGHT TO
STRENGTHEN OVER THE AREA ON SATURDAY...AND LINGER INTO SUNDAY AS LOW
PRESSURE ORGANIZES ACROSS THE CENTRAL PLAINS. INCREASED
N-NW GUSTS NEARING 30KTS OR MORE MAY BE POSSIBLE AGAIN FRIDAY
AFTERNOON INTO EARLY SATURDAY...STRONGEST OVER CENTRAL AND E LAKE
SUPERIOR.
&&

.HYDROLOGY...
ISSUED AT 441 AM EDT WED APR 23 2014

THE ARRIVAL OF MUCH COLDER AIR IS LEADING TO GREATLY REDUCED
SNOWMELT RUNOFF OVER UPR MI. BUT SINCE RUNOFF FROM RECENT ABOVE
NORMAL TEMPS AND SNOWMELT CONTINUES TO FLOW THRU THE GROUND...SOME
AREA STREAMS AND RIVERS ARE STILL RISING SLOWLY. LOCATIONS
EXPERIENCING RISES NEAR OR ABOVE BANKFULL HAVE BEEN ALSTON AND
CHASSELL ON THE STURGEON RIVER...CRYSTAL FALLS ON THE PAINT
RIVER...AND HARVEY ON THE CHOCOLAY RIVER. SINCE CHILLY AND DRY
WEATHER WILL CONTINUE THRU TONIGHT...SNOWMELT AND RUNOFF SHOULD
DIMINISH AND PREVENT THESE RIVERS FROM EXCEEDING FLOOD STAGE IN THE
SHORT TERM.

REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS.

UNSETTLED WEATHER WILL RETURN THURSDAY AND THURSDAY NIGHT AS ANOTHER
LOW PRESSURE SYSTEM MOVES FROM THE PLAINS TOWARD THE GREAT LAKES...
POTENTIALLY ADDING TO RUNOFF LATER THIS WEEK. AT THIS POINT THE BEST
CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE WEST HALF
OF UPPER MI...AND SPECIFICALLY THE KEWEENAW PENINSULA...WHERE
0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY FRIDAY MORNING. THERE
IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL
FALL AS SNOW...BUT THE BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW
PENINSULA. IF MORE OF THE PRECIPITATION FALLS AS SNOW...RUNOFF WILL
BE DELAYED UNTIL WARMER WEATHER RETURNS NEXT WEEK.

OVERALL...WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. THOSE
LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER
LEVELS OVER THE NEXT WEEK.
&&

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

$$

SHORT TERM...KF
LONG TERM...KC
AVIATION...ROLFSON
MARINE...KF
HYDROLOGY...KC






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.