Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 192007
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
407 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 NIGHT THROUGH SATURDAY)
ISSUED AT 405 PM EDT SAT APR 19 2014

TRICKY FORECAST FOR THE LONG TERM AS MODELS ARE HAVING DIFFICULTIES
COMING INTO AGREEMENT. DIFFERENCES LIE IN HOW THE MODELS HANDLE THE
PHASING OF TWO UPPER LEVEL TROUGHS...ONE ACROSS THE CANADIAN PRAIRIE
AND ONE IN THE CENTRAL PLAINS.

THE GFS/GEM/ECMWF HAVE THE NORTHERN WAVE SLIDING FROM ALBERTA AT 00Z
MONDAY INTO EASTERN MANITOBA/NORTHWESTERN ONTARIO BY 12Z MONDAY. BY
00Z TUESDAY...ALL MODELS HAVE THE TROUGH JUST SOUTH-SOUTHWEST OF
JAMES BAY. THE NAM FOLLOWS A SIMILAR PATH...BUT MOVES SLIGHTLY
QUICKER THAN THE REST. DIFFERENCES IN THE TILT OF THE TROUGH EXIST
BY THIS TIME...WITH THE ECMWF POSITIVELY TILTED AND FURTHER
WEST...AND THE GFS/GEM/NAM NEUTRALLY/NEGATIVELY TILTED AND FURTHER
EAST. THE GEM HAS A MUCH SHARPER TROUGH THAN THE REST OF THE MODELS.

THE SOUTHERN WAVE ALOFT IS FAIRLY BROAD AND EXTENDS FROM SOUTH
DAKOTA SOUTHWESTWARD INTO OKLAHOMA AND NORTHERN TEXAS AT 00Z MONDAY.
BY 12Z MONDAY THE  GFS/ECMWF SPORT A POSITIVE TILT EXTENDING FROM
IOWA INTO OKLAHOMA. THE GEM/NAM HAVE A WEAKER TROUGH...DEVELOPING
ONLY THE SOUTHERN MOST EXTENT IN OKLAHOMA. BY 00Z TUESDAY THE MODELS
COME INTO SOMEWHAT MORE AGREEMENT ON THE LOCATION OF THE POSITIVELY
TILTED TROUGH...EXTENDING IT FROM CENTRAL LOWER MICHIGAN
SOUTHWESTWARD INTO EASTERN OKLAHOMA.

THESE TWO WAVES MERGE INTO A DISJOINTED TROUGH BY 18Z
TUESDAY...MOVING TOWARDS THE EASTERN SEABOARD TOGETHER AS A LARGE
RIDGE BUILDS INTO THE CENTRAL CONUS.

UNFORTUNATELY...THESE TWO FEATURES WILL SIGNIFICANTLY IMPACT THE
FORECAST FOR MONDAY AND TUESDAY...INCLUDING WHETHER OR NOT SUNDAYS
FRONT SITUATED ACROSS THE S/SE CWA WILL DROP INTO SOUTHEASTERN LOWER
MI MONDAY OR BE DRIVEN NORTHWARD AS ANOTHER BATCH OF MOISTURE AND
WEAK WAA MOVES INTO THE AREA. THE GEM/ECMWF HAVE THE FRONT MOVING
NORTHEASTWARD...BRINGING ANOTHER ROUND OF PRECIPITATION TO UPPER
MICHIGAN...ESPECIALLY THE EAST AS A SURFACE LOW DEVELOPS IN RESPONSE
TO THE DEEPENING NORTHERN WAVE...ALLOWING THE A MORE DEFINED SFC LOW
TO CROSS THE NORTHERN GREAT LAKES REGION. THE GFS/NAM KEEP THE
DEVELOPING LOW FURTHER SOUTH OVER LOWER MI AND PUSH IT INTO THE
LOWER LAKES. THERE IS ALSO THE ISSUE OF THE COLD FRONT FROM THE
NORTHERN WAVE DROPPING INTO THE WEST/CENTRAL CWA BEHIND THE MAIN
PUSH OF PRECIPITATION ON MONDAY EVENING/TUESDAY. OVERALL...DECIDED
TO BLEND WITH THE ECMWF/GFS...BRINGING CHANCE POPS INTO THE EASTERN
CWA TO ACCOUNT FOR THE POSSIBLE NORTHWARD MOVEMENT OF THE FRONT AND
SLIGHT CHANCE/CHANCE INTO THE WEST AND CENTRAL FOR THE COLD FRONT
MOVING THROUGH ON MON EVE-TUESDAY AM.

TEMPERATURES ON MONDAY WILL BE WARM...WITH 850MB TEMPS OVER UPPER MI
RANGING FROM 6C TO 8C. THIS PUTS HIGHS INLAND AND WEST INTO THE
UPPER 50S AND LOW TO MID 60S. AREAS EASTWARD WILL SEE MORE CLOUD
COVER...SO PUT HIGHS IN THE LOW TO MID 50S. HIGH TEMPERATURES
THROUGH THE REMAINDER OF THE WEEK WILL BE IN THE 40S AND LOW TO MID
50S...AND IN THE UPPER 30S NEAR LAKE SUPERIOR ON SOME DAYS. WITH THE
RAIN AND WARM TEMPERATURES...EXPECT A PROLONGED PERIOD OF HIGHER
RIVER FLOWS DUE TO RUNOFF FROM SNOW MELT.

MODELS LARGELY AGREE WITH HIGH PRESSURE RETURNING BY TUESDAY EVENING
AND MUCH OF WEDNESDAY AS THE STRONGER RIDGE BUILDS INTO THE CENTRAL
CONUS...KEEPING WEATHER COOL AND QUIET BEFORE THE NEXT SYSTEM MOVES
IN. AGREEMENT IS SHORT LIVED HOWEVER...AS THE MORE POTENT
TROUGH/CLOSED LOW ALOFT MOVES INTO THE NORTHERN PLAINS WEDNESDAY
EVENING INTO THURSDAY. THE ECWMF IS MUCH SLOWER THAN THE
GEM/GFS...BRINGING THE PRECIPITATION INTO THE WESTERN/CENTRAL CWA BY
18Z THURSDAY. IT IS ALSO DEEPER THAN THE GFS/GEM. THE GEM/GFS ARE
MORE PROGRESSIVE...BRINGING PRECIPITATION INTO THE WESTERN CWA AS
EARLY AS WEDNESDAY AFTERNOON...AND THE ENTIRE CWA BY 12Z THURSDAY.
WILL CONTINUE WITH CONSENSUS POPS AGAIN...GIVEN SIGNIFICANT
DIFFERENCES IN TIMING. ON SATURDAY AFTERNOON...BOTH THE GFS/ECWMF
HAVE HIGH PRESSURE FILTERING IN BEHIND THE EXITING SYSTEM...LEADING
TO ANOTHER COOL AND QUIET WEATHER DAY.
&&

.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...MCD
AVIATION...SRF
MARINE...SRF
HYDROLOGY...SRF






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