Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 202039
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
439 PM EDT SUN APR 20 2014

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 357 PM EDT SUN APR 20 2014

QUITE THE DIFFERENCE IN CONDITIONS FROM THE LAKE MICHIGAN SHORELINE
TO THE WESTERN HALF OF UPPER MICHIGAN. THE AREA OF SHOWERS THAT
MOVED THROUGH UPPER MICHIGAN LAST NIGHT AND INTO THE EARLY MORNING
HOURS SLOWLY SLID SOUTHEAST THIS AFTERNOON AND IS NOW MAINLY
LOCATED IN NORTHERN LAKE MICHIGAN. THE CLOUDS AND RAIN (SOME
LOCATIONS ALONG THE SHORELINE SEEING 0.5-0.6IN OF ACCUMULATION) HAS
HELD TEMPS DOWN AND MAINLY IN THE UPPER 30S AND LOWER 40S (AIDED BY
SOUTHERLY WINDS OFF THE LAKE). MEANWHILE...JUST A SHORT DISTANCE TO
THE WEST AND THE SUNSHINE HAS HELPED TEMPERATURES RISE INTO THE
UPPER 50S AND LOWER 60S OVER CENTRAL UPPER MICHIGAN AND THE UPPER
60S TO A FEW 70S AT THE RAWS SITES IN THE WESTERN U.P. THIS
SUNSHINE AND DEEPER MIXING INTO THE DRIER AIR ALOFT INDICATED ON
THE 12Z KINL RAOB HAS ALLOWED DEWPOINTS TO FALL INTO THE LOWER 30S
OVER THE WESTERN U.P.

OVERALL...THERE WILL BE TWO FEATURES THAT WILL BE INFLUENCING THE
PRECIPITATION CHANCES FOR UPPER MICHIGAN TONIGHT AND MONDAY.
FIRST...THE THE PERSISTENT MID LEVEL MOISTURE PLUME THAT IS
CURRENTLY STRETCHING FROM NORTHERN IOWA THROUGH NORTHERN LAKE
MICHIGAN AND INTO ONTARIO. MODELS HAVE BEEN STRUGGLING WITH HOW FAR
NORTH THIS FEATURE TRACKS TONIGHT INTO MONDAY...IN ADDITION TO ITS
INTERACTION WITH THE NEXT WAVE MOVING THROUGH ON MONDAY. THIS
MORNING THERE WAS MORE OF A SOUTHWESTERLY COMPONENT TO THE
FLOW...AS THE UPPER LOW WAS LOCATED IN FAR NORTHERN ONTARIO. BUT
WITH THE EXPECTED TRACK TO THE EAST OF THIS UPPER LOW AND A WEAK
UPPER RIDGE OVER LAKE WINNIPEG EXPECTED TO SHIFT EAST INTO NORTHERN
ONTARIO TONIGHT...WOULD EXPECT THE 700-500MB FLOW TO BECOME A
LITTLE MORE WESTERLY. THIS WESTERLY FLOW SHOULD ALLOW THE DRIER AIR
SEEN ON THE 12Z KABR/KBIS/KINL SOUNDINGS TO CONTINUE TO SHIFT OVER
MUCH OF THE AREA AND HELP KEEP THE SHOWERS AT BAY. STILL THINK THE
SOUTH CENTRAL CWA COULD SEE A FEW SHOWERS TONIGHT AND SOME MID CLOUD
COVER AS THE 850MB FLOW TAKES A LITTLE LONGER TO VEER TO THE WEST.
WILL KEEP RAINFALL AMOUNTS ON THE LIGHT SIDE SINCE THE BETTER
MOISTURE AND PRECIPITATION SHOULD STAY TO THE SOUTH OF THE CWA. FOR
THE REST OF THE CWA...THE CLEARING SEEN THIS MORNING AND CONTINUING
THROUGH THE AFTERNOON SHOULD REMAIN IN PLACE DUE TO THE DRY AIR
MENTIONED PREVIOUSLY AND A WEAK HIGH PRESSURE RIDGE MOVING IN. THESE
CLEAR SKIES AND LIGHT WINDS WILL ALLOW FOR RADIATIONAL COOLING AND
ALLOW TEMPERATURES TO FALL INTO THE LOWER 30S OVER THE NORTHERN HALF
OF THE CWA. THERE IS THE POTENTIAL SOME LOCATIONS COULD EVEN FALL
INTO THE UPPER 20S...WHICH WOULD BE A TOUCH BELOW NORMAL. WITH THESE
FALLING TEMPS AND LIGHT WINDS...IT LEADS TO THE POTENTIAL FOR SOME
FOG DEVELOPMENT. THE DEEPER MIXING HAS ALLOWED AFTERNOON DEWPOINTS
OVER THE WEST TO FALL INTO THE LOWER 30S...WHILE THE CENTRAL CWA IS
STILL IN THE LOW-MID 40S WITH THE CLOSER PROXIMITY TO THE DEPARTING
CLOUDS. USING THOSE VALUES AS THE CROSSOVER TEMP TO GET A ROUGH
IDEA...WOULD EXPECT GROUND FOG TO OCCUR OVER MUCH OF THE
NORTH-NORTHWESTERN 2/3RDS OF THE U.P. THEREFORE...WILL CONTINUE TO
MENTION PATCHY FOG AWAY FROM THE MORE CLOUDY SOUTH CENTRAL AND DID
TREND UP TOWARDS AREAS OF FOG OVER THE CENTRAL U.P. WHERE THE
CROSSOVER TEMPERATURE VALUES ARE MORE SUPPORTIVE.

FOR MONDAY...THE LOCATION OF THE PRECIPITATION IN THE MORE WESTERLY
FLOW BRUSHING THE AREA WILL REMAIN A CONCERN...ALONG WITH A
SHORTWAVE MOVING THROUGH THE AREA. THIS SHORTWAVE IS CURRENTLY
DEPARTING THE ROCKIES ALONG THE US/CANADIAN BORDER AND IS EXPECTED
TO CONTINUE THAT TRACK ALONG THE BORDER TONIGHT AND
MONDAY...REACHING NORTHERN LAKE SUPERIOR BETWEEN 18Z-00Z. AN
ASSOCIATED BROAD SURFACE LOW STRETCHING FROM SOUTHERN CANADA AND
INTO THE NORTHERN CONUS WILL SHIFT EAST THROUGH THE WESTERN GREAT
LAKES REGION ON MONDAY. AS HAS BEEN THE CASE OVER THE LAST SEVERAL
DAYS...MODELS CONTINUE TO STRUGGLE WITH THE SOUTHWARD EXTENT OF THIS
WAVE AND POTENTIAL MERGING WITH THE EXISTING MID LEVEL MOISTURE
STREAM ALONG AND SOUTH OF THE SOUTHERN EDGE OF THE CWA. WITH THE
BULK OF THE FORCING FROM THE SHORTWAVE STAYING NORTH OF THE AREA
(ALTHOUGH THE SOUTHWEST EDGE DOES SWEEP OVER THE WESTERN CWA LATE
IN THE AFTERNOON) AND LIMITED MOISTURE SEEN ON THE SOUTHERN SIDE OF
THE SHORTWAVE...HAVE TO THINK THE NORTHWARD EXTENT OF THE SOUTHERN
FEATURE WILL DETERMINE PRECIPITATION CHANCES. WITH THE MORE
WESTERLY FLOW EXPECTED TONIGHT...FEEL THAT THE SOUTHERN STREAM
MOISTURE WILL BE FAIRLY SUPPRESSED TO THE SOUTH. THUS...LIKE THE
GENERALLY DRY IDEA SHOWN BY THE 12Z NAM/GFS/ECMWF FOR TOMORROW. THE
GEM-REGIONAL SHOVE HIGHER DEWPOINTS INTO THE AREA (LOWER 50S
OVER THE SOUTH HALF) DURING THE DAY TOMORROW AND IF THE BOUNDARY
SHIFTS FARTHER TO THE NORTH THAT MAY BE REASONABLE. BUT WITH THE
DRY AIR IN PLACE AND SOME FILTERED SUNSHINE WITH THE INCREASING
10-15KFT CLOUDS AHEAD OF THE SHORTWAVE...DON/T THINK DEWPOINTS WILL
GET THAT HIGH (ML DEWPOINTS WITH MOST MODELS IN THE LOWER 40S EAST
AND UPPER 30S WEST IN THE AFTERNOON DEPENDING ON WHEN THE LOW
MOVES THROUGH). THUS...WOULD EXPECT THE INSTABILITY SHOWN ON
THE GEM-REGIONAL (MLCAPES OF 300-700J/KG) TO BE OVERDONE AND LARGELY
DRIVING THE PRECIPITATION IT DEVELOPS. DUE TO THOSE
EXPECTATIONS...HAVE TRENDED POPS DOWN FOR THE MORNING HOURS AND
CONFINED TO THE SOUTH CENTRAL. DID LEAVE SOME ISOLATED POPS IN FOR
THE AFTERNOON HOURS DUE TO THE STRENGTH OF THE SHORTWAVE AND
COLD AIR DROPPING INTO THE CWA FROM THE NORTHWEST. IF THE SOUNDINGS
END UP AS DRY AS SHOWN ON THE 12Z NAM/GFS...DON/T EVEN THINK THE
STRENGTH OF THE SHORTWAVE WILL LEAD TO ANY PRECIPITATION. AS FOR
TEMPS...SHOULD SEE ANOTHER NORMAL TO ABOVE NORMAL TEMPERATURE DAY
FOR THE INTERIOR LOCATIONS AND NORMAL NEAR THE LAKE SHORES. MIXING
TO 900-850MB TEMPS SHOWN ON THE NAM WOULD YIELD HIGHS IN THE 60S FOR
INTERIOR LOCATIONS. LIGHT WINDS AND WARMING TEMPS SHOULD PRODUCE
LAKE BREEZES OFF LAKE MICHIGAN/SUPERIOR AND KEEP VALUES A LITTLE
COOLER. THEN AS WINDS TURN WESTERLY FROM WEST TO EAST IN THE
AFTERNOON BEHIND THE BROAD LOW PRESSURE AREA...WOULD EXPECT COOLING
OVER THE WEST WITH WINDS OFF THE ICE.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 438 PM EDT SUN APR 20 2014

A SERIES OF FAIRLY ENERGETIC SYSTEMS WILL TRACK ACROSS THE CONUS
OVER THE NEXT 7 TO 10 DAYS. GIVEN THE TIME OF YEAR...CAN`T RULE OUT
THE POSSIBILITY OF MID/UPPER LEVEL LOWS DEVELOPING/CLOSING OFF AND
SLOWING THE PROGRESSION DOWN. IF SO...DEPENDING ON WHERE IT
HAPPENS...SIGNIFICANT PCPN COULD BE IN THE OFFING ALONG WITH THE
POSSIBILITY OF LATE SEASON SNOW. AT THIS POINT...MEDIUM RANGE
GUIDANCE POINTS TOWARD A PROGRESSIVE PATTERN WITH THE FIRST
SHORTWAVE TROF PASSING ACROSS THE UPPER LAKES MON NIGHT. THIS WILL
BE FOLLOWED BY A MID/UPPER LEVEL RIDGE ARRIVING WED. ON ITS HEELS
WILL BE THE NEXT MORE POTENT SHORTWAVE TROF WHICH MOVES ONSHORE OVER
THE WRN CONUS TUE. BY THE TIME IT REACHES THE GREAT LAKES LATE IN
THE WORK WEEK...THIS SHORTWAVE TROF WILL HAVE INTERACTED WITH A NRN
STREAM WAVE DROPPING S THRU CNTRL CANADA. DEPENDING ON WHERE/WHEN
THE INTERACTION BTWN THE 2 WAVES OCCURS...PTYPE COULD BECOME MORE OF
AN ISSUE DURING THE PRIMARY PUSH OF PCPN ACROSS THE AREA. RIGHT
NOW...IT APPEARS RAIN WILL BE THE MAIN PTYPE. FEATURES INVOLVED
ARE CERTAINLY FAR ENOUGH OUT IN THE FCST CYCLE FOR IMPORTANT
ADJUSTMENTS TO OCCUR. IN ANY EVENT...THE INFUSION OF THE NRN STREAM
WAVE WILL RESULT IN A DUMP OF COLDER AIR/BLO NORMAL TEMPS LATE WEEK
INTO THE WEEKEND...INCLUDING AT LEAST SOME LIGHT SNOW ON THE
BACKSIDE OF THE LATE WEEK SYSTEM. BEYOND THIS 7 DAY FORECAST...
THERE ARE HINTS FLOW COULD BECOME QUITE BLOCKY ACROSS CANADA WHICH
MAY HOLD COOL AIR IN PLACE ACROSS MUCH OF THE NRN CONUS/SRN CANADA.
SO...TEMPS NEXT WEEK ARE MORE LIKELY TO BE IN THE NORMAL TO BLO
NORMAL RANGE RATHER THAN ABOVE NORMAL. KEEP IN MIND NORMALS NEXT
WEEK ARE GENERALLY 50S N TO LOW/MID 60S S.

BEGINNING MON NIGHT...COLD FRONT ASSOCIATED WITH SHORTWAVE PASSING
THRU THE UPPER LAKES WILL BE EXITING THE E IN THE EVENING. UNDER CAA
REGIME MON NIGHT...NAM/GFS INDICATE SIGNIFICANT LOW-LEVEL
MOISTENING...ESPECIALLY IN THE N/NNW WIND UPLSOPE AREAS...WHICH
RAISES THE PROSPECT FOR SOME -DZ/-FZDZ TO DEVELOP AS MOISTURE DOES
NOT EXTEND TO -10C ISOTHERM. LOW CONFIDENCE IF IT WILL HAPPEN... BUT
THE E WOULD BE MOST FAVORED.

AFTER SOME MORNING CLOUDS IN CYCLONIC FLOW AND THEN LIKELY A PERIOD
OF BKN CU DEVELOPMENT LATE MORNING THRU EARLY AFTN UNDER 850MB
THERMAL TROF...SKIES WILL CLEAR IN THE AFTN AS MUCH DRIER AIR MASS
SETTLES INTO THE AREA IN ASSOCIATION WITH SFC HIGH PRES RIDGE
SHIFTING INTO THE UPPER LAKES. N TO NW GRADIENT WIND AIDED BY LAKE
BREEZE COMPONENT WILL LEAD TO A CHILLY DAY ALONG LAKE SUPERIOR WITH
HIGH TEMPERATURES IN THE 30S. WELL INLAND...TEMPS SHOULD STILL RISE
WELL INTO THE 40S TO AROUND 50F UNDER LATE APR SUNSHINE.

IDEAL RADIATIONAL COOLING NIGHT SETS UP TUE NIGHT UNDER SFC HIGH
PRES AND CLEAR SKIES. PRECIPITABLE WATER OF 40-60PCT OF NORMAL WILL
AID THE COOLING PROCESS. FAVORED THE LOW END OF GUIDANCE...
ESPECIALLY WHERE DECENT SNOW COVER WILL STILL EXIST. TRADITIONAL
COLD SPOTS MAY SLIP INTO THE TEENS.

SFC HIGH PRES SLIPS E WED. ALTHOUGH 06Z GFS/00Z ECMWF SHOW PCPN
REACHING WRN UPPER MI LATE IN THE DAY WED ASSOCIATED WITH WEAK LEAD
SHORTWAVE CUTTING THRU MID/UPPER RIDGE WELL IN ADVANCE OF THE
AFOREMENTIONED LATE WEEK SYSTEM...WILL MAINTAIN DRY WEATHER THRU THE
AFTN AS EASTERLY LOW-LEVEL WIND COMPONENT EMANATING FROM DEPARTING
SFC HIGH SHOULD HELP HOLD LOW-LEVEL DRY AIR IN PLACE. 12Z RUNS HAVE
SLOWED EASTWARD PCPN PROGRESSION...SO DRY FCST SEEMS IN GOOD
SHAPE.

DESPITE COMPLEXITIES IN THE FLOW REGIME...MEDIUM RANGE GUIDANCE IS
IN GOOD AGREEMENT WITH THE SHORTWAVE TROF MOVING ONSHORE OVER THE W
COAST TUE AND REACHING THE GREAT LAKES FRI. WITH PUSH OF STRONGEST
WAA/ISENTROPIC ASCENT ARRIVING THU...HIGHEST POPS WILL BE USED AT
THAT TIME AS AN AREA OF RAIN WILL LIKELY MOVE ACROSS THE AREA.
GEM/ECMWF SHOW 850MB TEMPS HOVERING AROUND 0C WED NIGHT THRU THU ON
FRONT SIDE OF SYSTEM...BUT BOUNDARY LAYER SHOULD BE SUFFICIENTLY
WARM FOR ONLY RAIN GIVEN THAT IT`S LATE APR. STILL...IT WILL BE
SOMETHING TO MONITOR IN THE COMING DAYS DUE TO SOME UNCERTAINTY IN
THE NRN STREAM FLOW ACROSS CANADA AND THE INTERACTION IT HAS WITH
THE SHORTWAVE MOVING ACROSS THE CONUS. WOULDN`T TAKE MUCH OF
SOUTHWARD SHIFT OF SYSTEM TO RESULT IN ANOTHER LATE SEASON SNOW FOR
THE W AND N HIGHER TERRAIN. TODAYS 12Z ECMWF HAS TRENDED DEEPER WITH
THE MIDLEVEL LOW AS IT MOVES ACROSS THE UPPER LAKES THU NIGHT/FRI.
IF VALID...SOME ACCUMULATING SNOW WOULD BE POSSIBLE WITH DEFORMATION
PCPN SHIELD IMPACTING WRN AND NRN UPPER MI THU NIGHT/FRI.

ANY LINGERING PCPN WILL WIND DOWN/END SAT AS SYSTEM MOVES OFF TO THE
E. TEMPS SAT WILL BE WELL BLO NORMAL IN THE 30S N TO LOW/MID 40S
SCNTRL. ONLY SLIGHT MODERATION IS EXPECTED SUN AS SFC HIGH PRES
RIDGE NOSES INTO THE AREA.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 104 PM EDT SUN APR 20 2014

VFR CONDITIONS WILL PREVAIL THROUGH THE FIRST HALF OF THE TAF
FORECAST PERIOD...AS DRY AIR HAS SURGED OVER THE THREE TAF SITES.
THIS WILL CONTINUE INTO THE EVENING HOURS WITH WINDS COMING OFF
LAKE SUPERIOR. HEADING INTO TONIGHT...THE MAIN QUESTION MARK IS
IF/WHEN RADIATIONAL FOG DEVELOPS. HAVE FOLLOWED MOS GUIDANCE FOR
MUCH OF THE TIMING ON THE FOG AND INTENSITY. KIWD MAY END UP BEING
THE HIGHEST WITH VERY LIGHT AND UNFAVORABLE SOUTHEAST FLOW
DEVELOPING LATER TONIGHT AND LIKELY LIMITING VISIBILITY
RESTRICTIONS. A LITTLE CONCERNED WITH DRIER AIR OVER LAKE SUPERIOR
INFLUENCING KCMX AND HAVE NOT WENT AS LOW AS INDICATED BY SOME OF
THE MOS. AS FOR KSAW...THINK THEY HAVE THE BEST OPPORTUNITY TO FALL
TO LIFR BASED OFF THE HIGHER DEWPOINTS THIS AFTERNOON...THE CLOSER
PROXIMITY TO THE MOISTURE TO THE SOUTHEAST...AND LIGHT
SOUTH-SOUTHEAST UPSLOPE FLOW DEVELOPOING OVERNIGHT. EXPECT THE FOG
TO BURN OFF DURING THE MORNING AS MIXING INCREASE AND SOME MID
CLOUDS TO APPROACH TOWARDS AFTERNOON.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 357 PM EDT SUN APR 20 2014

GENERALLY LIGHT WINDS (LESS THAN 20KTS) ARE EXPECTED OVER THE NEXT
24 HOURS AS A WEAK HIGH PRESSURE RIDGE MOVES IN THIS EVENING. A
BROAD AREA OF LOW PRESSURE WILL MOVE ACROSS LAKE SUPERIOR MONDAY
AFTERNOON AND LEAD TO INCREASING NORTHWESTERLY WINDS MONDAY NIGHT
AND CONTINUING INTO TUESDAY. THE STRONGEST WINDS WILL BE OVER
EASTERN LAKE SUPERIOR WITH GUSTS UP TO 25KTS. ANOTHER AREA OF HIGH
PRESSURE WILL MOVE OVER THE AREA ON TUESDAY NIGHT AND REMAIN INTO
WEDNESDAY EVENING...PRODUCING ANOTHER PERIOD OF LIGHT WINDS. A LOW
PRESSURE SYSTEM MOVING OUT OF THE NORTHERN PLAINS ON WEDNESDAY
NIGHT WILL BRING INCREASING SOUTHEASTERLY FLOW ON THURSDAY. AT THIS
TIME...WINDS APPEAR TO STAY BELOW 25KTS FOR THURSDAY AND
FRIDAY...AS THE LOW MOVES THROUGH THE GREAT LAKES REGION.
&&

.HYDROLOGY...
ISSUED AT 438 PM EDT SUN APR 20 2014

SNOW WATER EQUIVALENT OVER THE W AND N PROBABLY RUNS IN THE 5 TO 9
INCH RANGE WITH LOCALLY HIGHER AMOUNTS. WARMER CONDITIONS CONTINUING
THRU MON WILL RESULT IN DECENT/STEADY SNOWMELT AND RUNOFF WITH
RIVERS RISING MORE QUICKLY AGAIN. FORTUNATELY...A SHOT OF COLDER AIR
WILL ARRIVE MON NIGHT/TUE. WITH LOW TEMPS SLIPPING BLO FREEZING MON
NIGHT AND ESPECIALLY TUE NIGHT (THE COLDEST NIGHT)...SNOWMELT RUNOFF
WILL EASE. TEMPS WILL RETURN CLOSER TO NORMAL...BUT STILL BLO...WED
THRU FRI BEFORE ANOTHER SURGE OF COLDER AIR DROPS TEMPS
SIGNIFICANTLY FOR THE WEEKEND. RAINFALL IS ALSO EXPECTED IN THE LATE
WEEK PERIOD...PARTICULARLY THU.

WITH A COUPLE OF COLDER PERIODS OVER THE NEXT WEEK...AND NO
SIGNIFICANT RAINFALL EXPECTED FOR NOW...WIDESPREAD FLOODING IS NOT
FORESEEN AT THIS TIME. HOWEVER...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...ROLFSON
AVIATION...SRF
MARINE...SRF
HYDROLOGY...ROLFSON






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