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 192005
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
405 PM EDT SAT APR 19 2014

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 359 PM EDT SAT APR 19 2014

A STRONG SHORTWAVE SPINNING OVER MANITOBA IS PRODUCING A SURFACE
LOW OF 1004MB OVER LAKE WINNIPEG. A SURFACE TROUGH STRETCHES
SOUTH-SOUTHEAST FROM THE LOW AND THROUGH WESTERN MINNESOTA. AHEAD
OF THIS SURFACE TROUGH...A MID LEVEL TROUGH IS MOVING EAST THROUGH
EASTERN MINNESOTA AND A SOUTHWEST TO NORTHEAST LINE OF SHOWERS
STRETCHES FROM CENTRAL MINNESOTA TO THE NORTHEAST ACROSS WESTERN
LAKE SUPERIOR. WATER VAPOR IMAGERY SHOWS AN ABUNDANT AMOUNT OF
MOISTURE AHEAD OF THIS TROUGH...WITH 12Z KMPX RAOB HAVING A PWAT OF
0.77IN. FATHER TO THE EAST...SOUTHEASTERLY LOW LEVEL FLOW HAS BEEN
FEEDING DRIER AIR INTO THE AREA BELOW 800MB (SEEN ON 12Z KGRB/KAPX
SOUNDINGS) AND HAS LED TO A GENERALLY DRY DAY WITH ONLY SCATTERED
HIGH CLOUDS. A POCKET OF WARM AIR ADVECTION OVER THE WESTERN LAKE
EARLIER TODAY DID PRODUCE SOME LIGHT RAIN SHOWERS OVER
ONTONAGON/HOUGHTON/KEWEENAW COUNTIES...BUT IT HAS SINCE SHIFTED
NORTHEAST. WITH THE FILTERED SUNSHINE...MIXING HAS LED TO
TEMPERATURES RISING INTO THE LOWER 50S OVER THE WEST ALONG THE
WISCONSIN BORDER...WITH GENERALLY 40S ELSEWHERE. THE COLD SPOT IS
OVER THE KEWEENAW PENINSULA WITH THE COOL FLOW OF LAKE SUPERIOR AND
AIDED BY EVAPORATIVE COOLING WHEN THE RAIN SHOWERS WENT THROUGH.

THE POTENT SHORTWAVE THAT IS IN SOUTHERN MANITOBA WILL SHIFT
NORTHEAST INTO FAR NORTHERN ONTARIO THIS EVENING AND PULL THE
ASSOCIATED SURFACE LOW WITH IT. THE ASSOCIATED LARGER SCALE FORCING
WILL FOLLOW SUIT AND KEEP THE MORE WIDESPREAD PRECIPITATION IN
CANADA. WHILE THAT IS OCCURRING...THE PUSH OF STRONG WAA AT
850-700MB THAT PRODUCED THE SHOWERS OVER MINNESOTA AND WESTERN LAKE
SUPERIOR THIS MORNING (BRUSHING FAR WESTERN UPPER MICHIGAN) IS
SLIDING NORTHEAST AND BECOMES FOCUSED OVER THE NORTHERN HALF OF
LAKE SUPERIOR. EXPECT THAT TO BE THE AREA WITH THE HIGHEST QPF/POPS
FOR TONIGHT...ESPECIALLY WITH THE HELP OF THE RIGHT REAR OF THE
WEST-EAST ORIENTATED UPPER JET.

THE MID LEVEL TROUGH WILL BE THE MAIN FOCUS FOR MUCH OF THE
PRECIPITATION TONIGHT. AS THAT TROUGH SHIFTS EAST LATE THIS
AFTERNOON AND EVENING...EXPECT THE SHOWERS THAT ARE MOVING NORTHEAST
FROM CENTRAL MN TO WESTERN LAKE SUPERIOR TO SLOWLY SHIFT EAST AND
ONSHORE IN THE WESTERN U.P. OVER THE NEXT FEW HOURS. HIGH RESOLUTION
MODELS HAVE A GOOD HANDLE ON THIS IDEA AND HAVE HIGH END LIKELY AND
DEFINITE POPS AS IT COMES ONSHORE. IN THE EVENING...MID LEVEL TROUGH
LOOKS TO SHIFT EAST A LITTLE FASTER THAN THE LOWER LEVELS...LEADING
TO VEERING FLOW AT/ABOVE 700MB STARTING THIS EVENING AND CONTINUING
INTO SUNDAY MORNING. EVEN THOUGH THAT OCCURS...THE LOWER LEVEL
(925-700MB) MOISTURE TRANSPORT STILL REMAINS PEGGED OVER THE
WESTERN/CENTRAL UPPER MICHIGAN THIS EVENING AND SHIFTING EAST INTO
THE OVERNIGHT HOURS. THE NOSE OF THAT MOISTURE ADVECTION IS
CO-LOCATED WITH THE PEAK OF THE 925-700MB WAA LARGELY OVER LAKE
SUPERIOR. BECAUSE OF THAT SEPARATION...PRECIPITATION AMOUNTS ARE A
LITTLE UNCERTAIN DUE TO THE MORE SCATTERED/BROKEN EXPECTATIONS OVER
THE WEST THIS EVENING...BUT THE GENERAL IDEA FROM THE MODELS IS FOR
A SLIGHT TREND DOWN TO THE QPF AMOUNTS IN THOSE AREAS. BUT ONCE THE
UPPER TROUGH REACHES THE EAST THE LOWER LEVEL FORCING BECOMES MORE
IN LINE WITH THE UPPER LEVEL FORCING AND WOULD EXPECT SOME INCREASE
IN THE PRECIPITATION AMOUNTS. IN ADDITION...THE LOW LEVEL (NEAR
SURFACE) FLOW BEGINS TO SHIFT MORE TO THE SOUTH AT THAT
TIME...TAKING AWAY THE INFLUX OF DRIER NEAR SURFACE AIR THAT MUCH OF
UPPER MICHIGAN WILL SEE THIS AFTERNOON AND EVENING FROM THE
SOUTHEASTERLY FLOW. ALONG THAT MID LEVEL TROUGH...THERE IS A THIN
RIBBON OF PWAT VALUES APPROACHING 0.75-1.0...WHICH WOULD SUPPORT THE
POTENTIAL FOR SOME BRIEF HEAVIER PRECIPITATION. OVERALL...OPTED TO
FOLLOW A GENERAL CONSENSUS OF THE NON GFS QPF AMOUNTS...SINCE THAT
MODEL IS ABOUT DOUBLE THE REST OF THE MODELS. THAT PRODUCES AMOUNTS
OF 0.1-0.2IN OVER THE WESTERN CWA AND 0.3-0.5IN OVER THE EASTERN
CWA. THAT IDEA MATCHES UP WELL WITH 00Z ECMWF ENSEMBLE AND 09Z/15Z
SREF PROBS FOR 12HR QPF.

WARM MOIST AIR SURGING INTO THE AREA TONIGHT SHOULD KEEP LOWS IN
THE UPPER 30S AND LOWER 40S OVER THE AREA. BEHIND THE RAIN...THERE
IS THE POTENTIAL FOR FOG TO DEVELOP. DO HAVE SOME QUESTIONS ON THE
EXTENT DUE TO THE LOW LEVEL WINDS THAT ARE EXPECTED TO STAY UP
THROUGH MUCH OF THE NIGHT AND MAY PRODUCE MORE LOW STRATUS THAN FOG.
THE WINDS WEAKEN THE MOST OVER THE WEST LATE TONIGHT AND WILL
CONTINUE TO MENTION SOME FOG THERE...BUT THINK IT WILL LARGELY
DEPEND ON THE AMOUNT OF RAIN EVEN THOUGH MELTING SNOW MAY MOISTEN
THE LOWER LEVELS.

SUNDAY...PRECIP LOCATION WILL LARGELY DEPEND ON WHERE THE
PRECIPITATION AND TROUGH STALLS OUT...BUT IT APPEARS THAT IT
WILL BE OVER NORTHERN LAKE MICHIGAN. THUS...WILL CONTINUE TO
MENTION SLIGHT/CHANCE POPS ALONG THE LAKE MICHIGAN SHORELINE AND
KEEP THEM NEARLY STATIONARY THROUGH MUCH OF THE DAY. BEHIND THE
PRECIPITATION TONIGHT...SHOULD SEE SOME CLEARING OVER THE NORTHWEST
1/3RD OF THE CWA THAT WILL CONTINUE THROUGH SUNDAY. THE CENTRAL PART
OF THE CWA DOES HAVE SOME QUESTIONS MARKS ON HOW MUCH 925-850MB
MOISTURE WILL REMAIN. AT THIS POINT...THINKING THERE WILL BE SOME
CLEARING IN THE MORNING (UNLESS FOG/STRATUS SETS UP)...BUT THAT WILL
AID SOME DIURNAL CU DEVELOPMENT OVER THE CENTRAL U.P.
MEANWHILE...THE AREAS NEAR LAKE MICHIGAN WILL LIKELY BE MOSTLY
CLOUDY THROUGH MUCH OF THE DAY. WITH ALL OF THE WARM AIR THAT HAS
SURGED NORTHEAST OVER THE AREA THIS AFTERNOON AND TONIGHT...SHOULD
SEE A WARM DAY ON SUNDAY...ESPECIALLY WHEN COMPARED TO WHAT HAS BEEN
EXPERIENCED OVER THE LAST SEVERAL DAYS. HAVE INTERIOR HIGHS IN THE
LOWER 60S OVER THE WEST/CENTRAL...WITH CLOUDS NEAR LAKE MICHIGAN
AND LAKE BREEZES OFF LAKE SUPERIOR KEEPING TEMPERATURES COOLER.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 428 AM EDT SAT APR 19 2014

MAIN FCST CONCERN IN THE LONGER TERM IS FOCUSED ON THE POTENTIAL
INTERACTION BTWN A STALLED FNT/RIBBON OF HIER MSTR JUST S OF UPR MI
AND A SHRTWV THAT IS FCST TO MOVE E ACRS SRN CANADA ON MON AND IF/
HOW MUCH RA WL FALL OVER UPR MI AND IMPACT AREA STREAMS/HYDRO.
CONFIDENCE IN THIS FCST IS LOWERED BY POOR MODEL AGREEMENT ON THE
INTERACTION BTWN THESE FEATURES.

SUN...AS SHRTWV/SFC LO OVER NW ONTARIO ON SUN MRNG MOVE E CLOSER TO
JAMES BAY BY LATE IN THE DAY...A SHRTWV RDG AND MID LVL DRYING ARE
FCST TO ADVANCE INTO THE UPR LKS BEHIND DEPARTING/WEAKENING
ATTENDANT COOL FNT AND WARM CONVEYOR BELT MSTR RIBBON. ALTHOUGH SOME
MODEL DIFFERENCES REMAIN ON HOW AGGRESSIVE THIS MID LVL DRYING WL
BE...THE PREVIOUSLY SLOWER CNDN MODEL SHOWS ENUF DRYING TO END THE
PCPN OVER ALL BUT THE FAR SE CWA BY 00Z. OPTED TO RETAIN FLAVOR OF
GOING FCST THAT SHOWS LINGERING POPS OVER THE SE HALF DIMINISHING
THRU THE DAY...AND ENDING OVER ALL BUT THE FAR SE BY 00Z MON.
OTRW...WITH DIURNAL HEATING...EXPECT LO CLDS/FOG OVER THE MELTING SN
PACK TO DSPT BY THE AFTN. H85 TEMPS IN THE 6-8C RANGE WL SUPPORT ABV
NORMAL TEMPS...BUT LGT WINDS ASSOCIATED WITH WEAK HI PRES UNDER THE
SHRTWV RDGING SHOULD ALLOW FOR LK BREEZES THAT WL BRING LOCAL
COOLING NEAR THE SHORES.

SUN NGT/MON...SUN NGT WL START DRY EXCEPT PERHAPS OVER THE FAR
SCENTRAL CLOSER TO LINGERING STNRY FNT/MSTR AXIS. BUT AS NEXT SHRTWV
MOVING ESEWD ACRS SCENTRAL CAN IN THE NW FLOW E OF BLDG RDG OVER WRN
CANADA APRCHS AND GENERATES SOME HGT FALLS OVER THE UPR LKS...SOME
OF THE MODELS...ESPECIALLY THE 00Z ECWMF/UKMET...SHOW DEEP MSTR TO
THE S EXPANDING BACK TO THE N LATE SUN NGT AND IMPACTING MAINLY THE
SCENTRAL AND E. THE NCEP MODELS ARE MUCH DRIER AND INDICATE MAINLY
SCT RA SHOWERS ASSOCIATED WITH THE PASSAGE OF THE INCOMING SHRTWV.
THE 00Z CNDN MODEL SHOWS THE PCPN EXPANDING BACK FARTHER TO THE N
BUT NOT UNTIL MON. WHILE THE BLDG RDG OVER THE SE CONUS SUPPORTS THE
FARTHER N SCENARIO FAVORED BY THE NON NCEP MODELS...THE RATHER LARGE
SEPARATION BTWN THE DISTURBANCES IN QUESTION AND ABSENCE OF A SGNFT
BACKING OF THE UPR LVL WINDS TO A MORE SW DIRECTION INDICATE THE
DRIER NCEP GUIDANCE IS ON THE RIGHT TRACK. THE MODELS TYPICALLY HAVE
A DIFFICULT TIME HANDLING INTERACTION/PHASING BTWN DISPARATE
DISTURBANCES...SO CONFIDENCE IS LO IN THIS PORTION OF THE FCST.
FORTUNATELY...EVEN THE WETTER SCENARIO FAVORED BY THE NON NCEP
MODELS POINTS TO HEAVIER RA OVER THE SCENTRAL AND ERN CWA...WHERE
LESS SN REMAINS. OTRW...MAINTAINED MENTION OF PATCHY FOG LATE SUN
NGT INTO MON MRNG WITH LGT WINDS/POTENTIAL FOR DRIER MID LVLS OVER
MELTING SN.

MON NGT...INCRSG NNW FLOW WITH H925 WINDS INCRSG UP TO 25-30 KTS
ASSOCIATED WITH DIGGING SHRTWV THRU THE GREAT LKS IS FCST TO DROP
H85 TEMPS AS LO AS -6 TO -7C BY 12Z TUE. WHILE THE INCOMING AIRMASS
IS NOT COLD ENUF FOR LK EFFECT SN...SOME OF THE MODELS SHOW ENUF
LLVL MSTR TO JUSTIFY CHC POPS. WITH THE ARRIVAL OF THE COLDER AIR...
EXPECT THE RA SHOWERS TO MIX WITH OR CHG TO SN...ESPECIALLY OVER THE
HIER TERRAIN OF THE W.

TUE INTO WED...CNDN SFC HI PRES RDG UNDER UPR RDG TRAILING DEPARTING
SHRTWV WL BRING A PERIOD OF COOLER AND DRIER WX TO THE CWA.

EXTENDED...NOT SURPRISINGLY...THERE REMAINS SGNFT DISAGREEMENT AMONG
THE LONGER RANGE MODELS ON THE HANDLING OF NEXT LO PRES THAT IS
LIKELY TO IMPACT THE UPR LKS LATER ON WED INTO FRI. THE 00Z ECMWF
INDICATES A COLDER SCENARIO WITH THE SFC LO PRES TRACKING TO THE S
OF UPR MI AND BLDG HI PRES JUST N OF LK WINNIPEG. THIS FCST WOULD
RESULT IN SOME MIXED PCPN AT THE ONSET AND LATER IN THE WEEK. THE
00Z GFS AND CNDN MODELS ON THE OTHER HAND SHOW A DEEPER LO FARTHER
TO THE N ALONG WITH A STRONGER SLY FLOW OF WARMER AIR. WL RELY ON
MODEL CONSENSUS FOR NOW.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 132 PM EDT SAT APR 19 2014

COMPLICATED 18Z TAF FORECAST DUE TO SEVERAL FACTORS COMING TOGETHER
THIS AFTERNOON AND TONIGHT. THE FIRST ITEM OF NOTE WILL BE RAIN
SHOWERS PUSHING EAST-NORTHEAST ACROSS KIWD/KCMX THIS AFTERNOON AND
INTO THE EVENING. WITH THE PRECIP FALLING OUT OF MID-CLOUDS...WOULD
EXPECT CONDITIONS TO STAY AS VFR DUE TO LOWER LEVEL DRY AIR IN
PLACE. AS THESE SHOWERS SHIFT EAST AND POTENTIALLY REDEVELOP
FARTHER TO THE SOUTHWEST...THEY SHOULD AFFECT KSAW LATER THIS
EVENING BUT THERE TOO CONDITIONS SHOULD STAY VFR. IN
ADDITION...EXPECT LLWS TO AFFECT KCMX/KSAW THIS EVENING AND INTO
THE OVERNIGHT HOURS AS A LOW LEVEL JET MOVES THROUGH. KIWD MAY SEE
A BRIEF PERIOD OF LLWS TOO...BUT IT WOULD ONLY BE A COUPLE HOURS IN
LENGTH.

THE MAIN UNCERTAINTY IN THE FORECAST COMES FROM THE FOG AND
LOW STRATUS POTENTIAL HEADING INTO THE OVERNIGHT HOURS. MOS GUIDANCE
SEEM TO BE TRENDING SLIGHTLY DRIER IN THE LOWER LEVELS...LIKELY DUE
TO SLIGHTLY LOWER RAINFALL AMOUNTS. IN ADDITION...LOW LEVEL WINDS
WON/T BE OVERLY SUPPORTIVE TO FOG DEVELOPMENT (ACTUALLY MORE LOW
STRATUS) UNTIL THEY WEAKEN LATE IN THE OVERNIGHT HOURS. WITH THE
UNCERTAINTY...HAVE CONTINUED THE IDEA OF MVFR VISIBILITY AT THIS
TIME...BUT IT IS HIGHLY DEPENDENT ON RAINFALL LOCATION AND LOW LEVEL
MOISTURE MOVING IN. ONE REASON FOR MORE OF A LOW STRATUS IDEA IS
WITH THE LOW LEVEL SOUTH-SOUTHWESTERLY WINDS...WHICH WOULD BE
DOWNSLOPING FOR KIWD AND OFF LAND AT KCMX (REDUCING COOLING FROM
LAKE SUPERIOR). SHOULD SEE A TREND TO VFR CONDITIONS SUNDAY MORNING
AS DRIER AIR MOVES IN.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EDT SAT APR 19 2014

SOUTHEAST WINDS OF 20 TO 30 KNOTS CURRENTLY OVER CENTRAL LAKE
SUPERIOR WILL DIMINISH TONIGHT AS A SURFACE TROUGH MOVES INTO
WESTERN LAKE SUPERIOR. THIS TROUGH WILL SHIFT EAST ACROSS THE LAKE
ON SUNDAY AND BRING LIGHT WINDS THROUGH MONDAY (GENERALLY BELOW
15KTS). A WEAK LOW WILL SHIFT EAST ACROSS LAKE SUPERIOR MONDAY
AFTERNOON AND EVENING AND BRING AN INCREASE TO THE WINDS OUT OF THE
NORTHWEST. AT THIS POINT...WINDS SHOULD REMAIN BELOW 20KTS MONDAY
NIGHT THROUGH TUESDAY. HIGH PRESSURE WILL BUILD OVER THE UPPER
GREAT LAKES REGION TUESDAY AFTERNOON AND REMAIN THROUGH WEDNESDAY
AND KEEP WINDS BELOW 15KTS. A LOW PRESSURE SYSTEM DEVELOPING IN THE
NORTHERN/CENTRAL PLAINS ON WEDNESDAY WILL APPROACH THE UPPER GREAT
LAKES REGION ON THURSDAY.
&&

.HYDROLOGY...
ISSUED AT 405 PM EDT SAT APR 19 2014

THE HEAVY SNOWFALL THIS PAST THURSDAY 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 MICHIGAN INTO MON /THE UPPER 50S AND LOW 60S AWAY FROM
LOCAL LAKE COOLING ON SUN AND MON/ WITH DEWPTS RISING AS HIGH AS THE
LOW 40S...A GOOD DEAL OF MELTING SHOULD OCCUR. EXCEPT FOR
TONIGHT...LOW TEMPS WILL FALL TO AT LEAST NEAR FREEZING...LIMITING
CONCERNS OF RAPID MELTING. COOLER AIR WILL RETURN MON NIGHT INTO
THU...SOMEWHAT MODERATING THE MELT DOWN. HIGHS ARE STILL EXPECTED TO
RANGE FROM THE 40S TO THE LOW 50S.

AS FOR PRECIPITATION...AN ADDITIONAL 0.10 TO 0.50 INCH OF LIQUID IN
THE FORM OF RAIN IS EXPECTED LATE THIS AFTERNOON INTO EARLY SUN
AFTERNOON. FORTUNATELY...THE HEAVIER RAIN IS FORECAST OVER THE EAST
WHERE THERE IS GENERALLY LESS SNOW ON THE GROUND. BUT WITH THE
ADDITIONAL LIQUID ADDED TO THE SNOWPACK FROM THE RECENT SNOW
STORM...WARM TEMPERATURES/GREATER SNOWMELT...AND LIGHT TO MODERATE
RAINFALL...A PROLONGED PERIOD OF HIGHER RIVER FLOWS ARE EXPECTED.

ALTHOUGH WIDESPREAD FLOODING IS NOT A CONCERN AT THIS TIME...ANY
RIVER THAT HAS ICE REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN
DELTA COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER
LEVELS THIS WEEK. 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...SRF
LONG TERM...KC
AVIATION...SRF
MARINE...SRF
HYDROLOGY...SRF





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