Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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 181945
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
345 PM EDT FRI APR 18 2014

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 344 PM EDT FRI APR 18 2014

A SHORTWAVE TROUGH IS CURRENTLY OVER THE NRN ROCKIES...WITH A
STRENGTHENING SFC LOW OVER MT/WY. ADDITIONALLY...THERE IS A WEAK
SHORTWAVE TROUGH AND 1031MB SFC HIGH OVER THE CWA. THE ROCKIES
SHORTWAVE WILL MOVE TO ECENTRAL MANITOBA/ECENTRAL ONTARIO BY 00Z
SUN.

CLEARING SKIES BEHIND THE WEAK SHORTWAVE OVERHEAD MAY ALLOW SOME FOG
TO DEVELOP OVER PORTIONS OF THE ERN HALF OF THE CWA. HIGH CLOUDS
MOVING INTO THE WRN CWA EARLIER TONIGHT WILL LIMIT FOG POTENTIAL
THERE.

PRECIP WILL MOVE INTO THE WRN CWA SAT MORNING AS STRONG FORCING FROM
ISENTROPIC ASCENT/WAA AND LOW-MID LEVEL MOISTURE ADVECTION. THE
MOISTURE TRANSPORT WILL BE NEEDED AS THE AIRMASS ABOVE THE NEAR SFC
INVERSION WILL BE QUITE DRY. THIS DRYNESS SHOULD HOLD THE PRECIP OFF
UNTIL AFTER 12Z OVER UPPER MI...WHICH ALLOWS FOR WARMER AIR TO MOVE
IN...MAKING RAIN THE DOMINANT PTYPE ON SAT. DO HAVE SOME SNOW EARLY
OVER THE KEWEENAW...BUT WOULD NOT BE SURPRISED TO NOT SEE ANY PRECIP
UNTIL LOW-MID LEVEL TEMPS WARM ENOUGH FOR ALL RAIN. ANOTHER AREA OF
MIXED PRECIP IS OVER FAR WRN UPPER MI WHERE THE RAIN WILL START
BEFORE SFC TEMPS ARE ABOVE FREEZING...SOME SOME VERY MINOR FREEZING
RAIN ACCUMULATIONS ARE POSSIBLE THERE EARLY. AS FAR AS PRECIP
AMOUNTS...HAVE NO QPF SCENTRAL AND E...WITH UP TO 0.40 INCHES OVER
THE KEWEENAW ON SAT. THE PRECIP MOVES SE ACROSS THE REST OF THE CWA
SAT NIGHT INTO SUN...SEE THE LONG TERM DISCUSSION FOR THE DETAILS OF
THAT TIME FRAME.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 425 AM EDT FRI APR 18 2014

MAIN FCST CONCERNS IN THE LONG TERM WL BE ON TIMING/POPS/PCPN TOTALS
AND HYDRO IMPACTS OVER THE WEEKEND ASSOCIATED WITH SHRTWV NOW MOVING
INTO THE PAC NW AND WHICH IS FCST TO SHIFT E ACRS SRN CANADA
SAT/SUN. LOOKS LIKE A PERIOD OF RELATIVELY QUIET WX EARLY NEXT WEEK
FOLLOWING THE PASSAGE OF THIS SHRTWV TO THE E.


SAT...SHRTWV NOW MOVING INTO THE PAC NW AND ASSOCIATED SFC LO ARE
FCST TO BE JUST W OF LK WINNIPEG AT 12Z SAT AND THEN OVER NW ONTARIO
BY 00Z SUN. ALTHOUGH ALL BUT PERHAPS THE NW CWA WL BE DRY AT 12Z ON
WRN FLANK OF DEPARTING SFC HI PRES CENTERED NEAR JAMES BAY...
VIGOROUS WAD/ISENTROPIC ASCENT BEST SHOWN ON THE 285-295K SFCS/DEEP
LYR QVECTOR CNVGC/H85-7 WARM FGEN/IMPRESSIVE H3-2 DVGC ON THE SE
FLANK OF THE SHRTWV TRACK ARE FCST TO IMPACT MAINLY THE NW HALF OF
UPR MI AS H85 SSW WINDS INCRS UP TO 50 KTS IN THE AFTN. SINCE THE
BEST DYNAMIC FORCING/MSTR CNVGC ARE PROGGED TO IMPACT MAINLY THE NW
HALF...GUIDANCE SHOWS MUCH LIGHTER PCPN...IF ANY AT ALL...FALLING
OVER THE FAR SE FARTHER FM THE SHRTWV/SFC LO TRACK AND WHERE DEEPER
DRY AIR WL BE MORE RESILIENT. SO MAINTENED LOWER POPS IN THAT AREA.
AFTER A CHILLY NGT...WITH H85 TEMPS AOB 0C AT 12Z SAT AS WELL AS
SOME LINGERING NEAR SFC DRY AIR THAT MAY MAINTAIN WBLB TEMPS JUST
BLO 32 NEAR THE ONSET OF THE PCPN...THERE IS SOME CONCERN THERE MAY
BE A WINTRY MIX OF PCPN ON SAT MRNG. BUT ANY MIXED PCPN IN THE MRNG
WL QUICKLY TURN TO RA AS THE STRENGTHENING SSW FLOW ADVECTS MUCH
WARMER AIR INTO THE UPR LKS IN THE PRESENCE OF DIURNAL HEATING. AS
FOR QPF...THE WETTER MODELS SHOW AS MUCH AS 0.50-0.75 INCH OF WATER
EQUIVALENT PCPN FALLING OVER THE NW THRU 00Z SUN. EXPECT SOME FOG TO
DVLP OVER THE W LATER IN THE DAY AS HIER SFC DEWPTS SURGE TO THE N
OVER THE MELTING SN. THE 00Z CNDN MODEL IS MOST AGGRESSIVE WITH THE
LLVL MSTR SURGE AND INDICATES SFC DEWPTS WL RISE TO 45 AT IWD.

SAT NGT...AS THE SHRTWV/SFC LO CONTINUE E THRU NW ONTARIO ON THE NRN
FLANK OF BLDG UPR RDG OVER THE SE CONUS...ATTENDANT COLD FNT IS FCST
TO DRIFT INTO THE WRN CWA OVERNGT. WHILE SOME RA IS FCST TO CONTINUE
UNDER THE WARM CONVEYOR BELT MSTR BAND AHEAD OF THIS FNT UNDER THE
DYNAMIC FORCING ON THE SRN FLANK OF THE DISTURBANCE TO THE N...THE
ARRIVAL OF DRIER AIR ALF IN THE JET SURGE REGION OF THE SHRTWV THAT
IS FCST TO PUSH AHEAD OF THE SFC FNT WL DIMINISH THE PCPN AT LEAST
OVER THE NW HALF OF THE CWA WHERE THE MID LVL DRYING IS FCST TO BE
MOST EMPHATIC. THE 00Z NCEP MODELS ARE MOST AGGRESSIVE WITH THE MID
LVL DRYING. WL RETAIN THE HIER POPS OVER THE SE CWA...WHERE THE WARM
CONVEYOR BELT MSTR RIBBON IS FCST TO LIE AT 12Z SUN. GOING FCST
APPEARS TO HAVE A PRETTY GOOD HANDLE ON THE EXPECTED TRENDS. THERE
SHOULD BE RELATIVELY LTL DIURNAL TEMP FALL WITH ALL BUT THE FAR W
REMAINING IN THE WARM SECTOR. SUSPECT AREAS OF FOG WL DVLP WITH
MELTING SN/HIER SFC DEWPTS UNDER THE MID LVL DRYING.

SUN...AS THE MID LVL DRYING IMPACTS MOST OF THE CWA ON SUN...EXPECT
GENERALLY DRY WX. BUT WL RETAIN SOME POPS OVER THE SE CWA...WHERE
THE ECWMF/CNDN MODELS ARE LESS AGGRESSIVE WITH THE MID LVL DRYING
AND HOLD THE NRN EDGE OF THE WARM CONVEYOR BELT MSTR IN LONGER. MRNG
LO CLDS/FOG OVER THE NW SHOULD BURN OFF TO ALLOW AT LEAST PARTIAL
SUNSHINE IN THE PRESENCE OF DIURNAL HEATING/INCRSG SUN ANGLE.

SUN NGT/MON...MOST OF THE MEDIUM RANGE GUIDANCE HINTS ANOTHER SHRTWV
MAY MOVE THRU THE SCENTRAL GRT LKS AND INVIGORATE SHRA ACTIVITY
ALONG THE MSTR RIBBON STRETCHED W-E OVER THE CENTRAL LKS...INCLUDING
AT LEAST THE FAR SCENTRAL CWA. WL RETAIN SOME CHC POPS IN THIS AREA.
TEMPS SHOULD RUN AOA NORMAL WITH H85 TEMPS 5 TO 7C. MORE FOG IS
LIKELY SUN NGT OVER THE MELTING SN PACK...ESPECIALLY OVER THE NRN
TIER IF THE MID LVLS DRY OUT AND A WEAK SFC HI WITH LGT WINDS BLDS
OVHD.

EXTENDED...AS AN UPR RDG BLDS OVER THE ROCKIES...AN AMPLIFYING NW
FLOW ALF WL PUSH COOLER CNDN AIR INTO THE UPR LKS FOR TUE. ALTHOUGH
THERE COULD BE SOME SHRASN ASSOCIATED WITH THE COLD FROPA ON MON NGT
INTO EARLY TUE...ANY PCPN SHOULD BE LGT. TUE INTO WED SHOULD FEATURE
DRY AND COOLER WX WITH CNDN HI PRES DOMINATING. NEXT CHC FOR PCPN WL
THEN ARRIVE LATER WED AND THU AS ANOTHER FAIRLY STRONG SHRTWV MOVES
E FM THE PLAINS. NOT SURPRISINGLY...VARIOUS OPS MODELS SHOW A WIDE
RANGE OF PSBL WX. THE COLDER 00Z ECMWF WOULD SUPPORT A PTYPE OF
MAINLY SN AS THIS SHRTWV MOVES E AT THE SAME TIME ARCTIC HI PRES
BLDS OVER SCENTRAL CANADA AND PUSHES COLDER AIR INTO THE UPR LKS.
BUT THE 00Z GFS SHOWS A WARMER SCENARIO WITH A STRONGER S WIND THAT
WOULD LIMIT ANY MIXED PCPN TO NEAR THE ONSET OF THE EVENT.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 125 PM EDT FRI APR 18 2014

VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD...WITH THE EXCEPTION
BEING POSSIBLE FOG AT SAW TONIGHT. IF MID-HIGH CLOUDS DO NOT ARRIVE
QUICK ENOUGH TONIGHT...COULD SEE SOME FOG DEVELOP AT SAW. SOME RAIN
AND SNOW IS POSSIBLE BY LATE SATURDAY MORNING AT KIWD AND KCMX...BUT
MODELS HAVE BEEN SLOWER WITH BRINGING THIS IN SO LEFT IT OUT OF THE
FORECAST FOR NOW.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 344 PM EDT FRI APR 18 2014

WINDS GENERALLY BELOW 20 KTS THROUGH THE ENTIRE FORECAST PERIOD. ONLY
EXCEPTION WILL BE SATURDAY AND SATURDAY NIGHT AS EAST TO SOUTHEAST
WINDS INCREASE TO 20 TO 30 KTS ON FLANK OF LOW PRESSURE MOVING FROM
NORTHERN PLAINS INTO NORTHERN ONTARIO.
&&

.HYDROLOGY...
ISSUED AT 425 AM EDT FRI APR 18 2014

THE RECENT HEAVY SNOWFALL ACROSS WESTERN UPPER MI HAS REPLENISHED
SOME OF THE WATER CONTENT THAT WAS LOST DURING THE WARMER CONDITIONS
OVER THE PAST TWO WEEKS. THE WESTERN HIGH TERRAIN NOW HAS 6 TO 8
INCHES OF WATER EQUIVALENT...WITH LOCALIZED 10 INCH AMOUNTS. SINCE
TEMPERATURES ARE EXPECTED TO BE AT OR SLIGHTLY ABOVE AVERAGE ACROSS
UPPER MI THIS WEEKEND INTO MON /AS HI AS THE 50S AWAY FROM LOCAL
LAKE COOLING ON SUN AND MON/...A GOOD DEAL OF MELTING SHOULD OCCUR.
EXCEPT FOR SAT NIGHT...LOW TEMPERATURES WILL FALL TO AT LEAST NEAR
FREEZING...LIMITING CONCERNS OF RAPID MELTING. SOMEWHAT COLDER AIR
WILL RETURN ON MON NIGHT INTO AT LEAST WED...MODERATING THE MELT
DOWN.

AS FOR PRECIPITATION...AN ADDITIONAL 0.5 TO 0.75 INCH OF LIQUID IN
THE FORM OF MOSTLY RAIN IS EXPECTED SAT AND SAT NIGHT. WITH THE
ADDITIONAL PRECIPITATION FROM THE RECENT SNOW STORM AND ON SAT...A
PROLONGED PERIOD OF HIGHER RIVER FLOWS ARE EXPECTED. THOUGH
WIDESPREAD FLOODING IS NOT A CONCERN AT THIS TIME...REMAINING ICE ON
THE RIVERS COULD LEAD TO POTENTIAL ICE JAMS ONCE THE WARMER AIR
ARRIVES ON SAT THRU MON. THOSE LIVING AROUND RIVERS...CREEKS... AND
STREAMS SHOULD MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE
JAMS CAN FORM AND BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING
RIVER LEVELS.
&&

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

$$

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






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