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 212355
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
755 PM EDT MON APR 21 2014

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 415 PM EDT MON APR 21 2014

WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW REGIME ACROSS
THE CNTRL AND ERN CONUS. IN THE NRN STREAM...A VIGOROUS SHORTWAVE
WAS MOVING ACROSS NRN ONTARIO JUST TO THE N OF LAKE SUPERIOR. IN THE
SRN STREAM...ANOTHER WAVE WAS MOVING ACROSS THE MID AND LWR
MISSISSIPPI VALLEY. DESPITE STRENGTH AND PROXIMITY OF NRN STREAM
WAVE...IT`S ONLY BEEN IN THE LAST HR THAT ISOLD -SHRA HAVE MANAGED
TO DEVELOP ALONG ASSOCIATED SFC COLD FRONT WHICH IS RUNNING FROM
NEAR ISLE ROYALE ACROSS THE KEWEENAW AND THEN S THRU IRON COUNTY.
LIMITED COVERAGE IS DUE TO LACK OF INSTABILITY AND THE FACT THAT
DEEP LAYER FORCING WITH WAVE IS PASSING MOSTLY N OF UPPER MI.

OVER THE NEXT SEVERAL HRS...WILL CARRY MAINLY ISOLD -SHRA COVERAGE
ALONG COLD FRONT AS IT SWEEPS E. ATTENTION THEN TURNS TO HEALTHY CAA
AND LOW CLOUD/-FZDZ/DZ POTENTIAL. WITH 850MB TEMPS FALLING TO AROUND
-8C...LAKE EFFECT PCPN WON`T BE A CONCERN TONIGHT INTO TUE MORNING.
HOWEVER...MODELS CONTINUE TO SHOW SIGNIFICANT LOW-LEVEL MOISTENING
TONIGHT WHICH APPEARS ON TRACK GIVEN IFR CIGS THAT WERE OBSERVED
UPSTREAM IN NRN MN/ADJACENT ONTARIO EARLIER TODAY. DAYTIME HEATING
HAS RAISED CIGS...BUT CLOUDS CONTINUE TO HEAD SE EVEN THOUGH SLOWED
BY MIXING OUT OF MOISTURE AT THE LEADING EDGE. ONCE DAYTIME HEATING
DIMINISHES...CLOUDS WILL MAKE A QUICKER RUN TO THE SE INTO UPPER
MI. EXAMINATION OF FCST SOUNDINGS SHOW MOISTURE DEPTH INCREASES TO
800 TO 700MB...AND WITH TEMPS WITHIN THE MOISTURE DEPTH WARMER THAN
-10C...PRESENCE OF ICE CRYSTALS IS UNLIKELY. SO...IF THERE IS ANY
PCPN...PTYPE SHOULD BE JUST -DZ/-FZDZ. HOWEVER...SINCE MODEL TREND
HAS BEEN FOR MOISTURE DEPTH TO BE DEEPER AND CLOSER TO -10C...WILL
INCLUDE A MENTION OF FLURRIES AS WELL. WHILE CONFIDENCE IS NOT
HIGH...WILL CONTINUE WITH LOW POPS FOR -DZ/-FZDZ/FLURRIES
OVERNIGHT THRU TUE MORNING...MAINLY IN THE AREAS WHERE UPSLOPING
OCCURS WITH A NNW WIND. WITH THE BETTER MOISTURE OVER THE E...WILL
NOT MENTION ANY PCPN OVER THE FAR W.

ON TUE...IT APPEARS NOW THAT CLEARING TREND WILL BE SLOWER WITH
850MB TROF FIRMLY OVER THE FCST AREA AT 18Z. ANY LOCATIONS THAT
START THE DAY WITH SOME SUNSHINE WILL SEE CU/STRATOCU RAPIDLY
DEVELOP. DURING THE MID AND LATE AFTN...THE LAKE WILL BECOME A
STABILIZING INFLUENCE...RESULTING IN CLOUDS CLEARING OUT OVER THE
LAKE FIRST. THEN...THE CLEARING WILL SPREAD INLAND. WITH GRADIENT
N/NW WINDS ENHANCED BY LAKE BREEZE...IT WILL BE A BLUSTERY/SHARPLY
COLDER DAY WITH TEMPS 20 TO POSSIBLY AS MUCH AS 30 DEGREES COLDER IN
SOME SPOTS. IT WILL BE ESPECIALLY CHILLY ALONG LAKE SUPERIOR
WHERE TEMPS WON`T GET ABOVE THE MID 30S AT BEST. OVER THE FAR
SCNTRL...TEMPS MAY RISE TO AROUND 50F.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 409 PM EDT MON APR 21 2014

HIGH PRESSURE BUILDING INTO THE UPPER GREAT LAKES REGION ON TUESDAY
WILL LEAD TO A DRY PERIOD FOR TUESDAY NIGHT AND MUCH OF WEDNESDAY.
THERE MAY BE A FEW LINGERING CLOUDS OVER THE FAR EAST TO START THE
EVENING...BUT OTHERWISE EXPECT MOSTLY CLEAR SKIES TUESDAY NIGHT AND
INTO WEDNESDAY ACROSS THE U.P. LOWS ON TUESDAY NIGHT WILL BE BELOW
NORMAL AND IN THE 20S FOR MOST LOCATIONS. DID TREND SOME OF THE
INTERIOR COLD SPOTS IN THE TEENS SINCE THE HIGH WILL BE OVERHEAD
AND PWATS OF 40-45 PERCENT OF NORMAL WOULD SUPPORT GOING AT OR
BELOW MOS GUIDANCE. THE APRIL SUNSHINE SHOULD HELP WARM TEMPS BACK
CLOSER TO NORMAL FOR WEDNESDAY. LIGHT WINDS WILL GRADUALLY TURN TO
THE SOUTHEAST DURING THE AFTERNOON...BUT THEY SHOULD BE LIGHT
ENOUGH TO ALLOW LAKE BREEZES TO DEVELOP NEAR THE GREAT LAKES
SHORELINES AND KEEP TEMPERATURES COOLER THERE.

THE BULK OF THE LONG TERM FORECAST DEALS WITH AN UPPER LEVEL TROUGH
AND ASSOCIATED LOW PRESSURE SYSTEM THAT MOVES THROUGH THE GREAT
LAKES REGION WEDNESDAY NIGHT AND LIKELY CONTINUING INTO SATURDAY.
THIS UPPER TROUGH IS CURRENTLY WEST OF THE PACIFIC NORTHWEST AND
WILL COME ONSHORE TONIGHT. AS THIS SYSTEM CROSSES THE ROCKIES...A
SURFACE LOW WILL DEVELOP IN THE LEE OF THE CANADIAN/NORTHERN
ROCKIES AND SHIFT EAST INTO THE UPPER MISSISSIPPI VALLEY ON
THURSDAY. AS THIS OCCURS...BROAD ISENTROPIC ASCENT ON THE 290-305K
SURFACES WILL SPREAD NORTHEAST INTO UPPER MICHIGAN ON WEDNESDAY
NIGHT. THIS FIRST WAVE WILL STEADILY PUSH NORTHEAST THROUGH
THURSDAY...WHILE A SECONDARY WAVE OF PRECIPITATION MOVES IN ON
THURSDAY AHEAD OF THE UPPER TROUGH AXIS MOVES INTO THE UPPER
MISSISSIPPI VALLEY AND NEARS THE UPPER GREAT LAKES. THIS UPPER
TROUGH WILL SHIFT THE HEAVIEST PRECIPITATION OVER THE NORTHERN
HALF OF LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT WITH THE
MOISTURE PRESENT AND FORCING FROM THE UPPER TROUGH...WOULD EXPECT
LINGERING LIGHT SHOWERS TO BE ONGOING OVER THE AREA FRIDAY INTO
FRIDAY NIGHT. PRECIPITATION TYPE IS VERY TRICKY AT THIS POINT DUE TO
THE VARYING SOLUTIONS IN THE MODELS WITH THE THERMAL FIELD WEDNESDAY
NIGHT INTO THURSDAY. AS THE INITIAL SURGE OF PRECIP MOVES INTO THE
AREA...IT ENCOUNTERS A ISOTHERMAL LAYER FROM THE SURFACE THROUGH
700MB WITH TEMPERATURES AT OR JUST ABOVE FREEZING. THIS LAYER
REMAINS STEADY THROUGH MUCH OF THURSDAY. AS FOR THE MODELS...THE
12Z GFS HAS TRENDED A LITTLE COOLER COMPARED TO THE PREVIOUS
RUNS...THE 12Z ECMWF REMAINS THE COOLEST AND THE 12Z GEM IS
IN BETWEEN INITIALLY. UNFORTUNATELY IT IS DIFFICULT TO GET TOO
SPECIFIC IN THESE SITUATIONS AS JUST A SLIGHT CHANGE IN TEMPERATURE
BETWEEN 925-700MB OF 1-2C ONE WAY OR ANOTHER CAN MAKE A HUGE
DIFFERENCE IN THE PRECIP TYPE AND ASSOCIATED IMPACTS. THUS...WILL
FOLLOW AN IDEA OF RAIN/SNOW MIX WITH THE INITIAL SURGE OF PRECIP AND
LIKELY TRANSITIONING TO MORE RAIN DURING THE DAY THURSDAY (OVER
THE SOUTH HALF). THE NORTHWARD EXTENT OF THIS TRANSITION IS
UNCERTAIN AT THIS POINT AND WILL PLACE IT OVER THE NORTH HALF OF
LAKE SUPERIOR THURSDAY AFTERNOON/EVENING. COLDER AIR WILL BEGIN TO
SHIFT INTO THE AREA ON THURSDAY NIGHT AS THE LOW SHIFTS EAST ACROSS
UPPER MICHIGAN AND LEAD TO A TRANSITION TO ALL SNOW INTO FRIDAY. BY
THE TIME THE PRECIPITATION WILL START TO TRANSITION TO ALL
SNOW...THE HEAVIEST RATES WILL HAVE DEPARTED THE AREA AND EXPECT
MORE OF A SCATTERED/LIGHT PRECIP TO REMAIN. WILL CONTINUE THE
PREVIOUS SHIFTS IDEA OF THE HIGHEST QPF OVER THE WESTERN HALF OF
THE CWA AND AROUND 0.5-1.0IN THROUGH THURSDAY EVENING. THAT MATCHES
UP WELL WITH SOME OF THE ECMWF/GFS QPF PROBS. AS MENTIONED
EARLIER...SNOW POTENTIAL IS TRICKY BUT THE SLIGHTLY COOLER
TREND SEEN IN THE 12Z MODELS CREATES CONCERN FOR MEASURABLE (AND
POTENTIALLY SIGNIFICANT) SNOWFALL OVER THE KEWEENAW DUE TO ITS
CLOSER PROXIMITY TO THE COLDER AIR TO THE NORTH. FINALLY FOR THIS
SYSTEM...THE COLD AIR AND BREEZING CONDITIONS SURGING IN BEHIND THE
LOW ON FRIDAY AND INTO SATURDAY WILL MAKE IT FEEL MORE LIKE MARCH
ACROSS THE AREA. WIND CHILL VALUES FRIDAY NIGHT AND INTO SATURDAY
WILL BE IN THE TEENS AND 20S WITH THE LOWEST VALUES NEAR LAKE
SUPERIOR.

MODELS DO DIFFER ON HOW QUICKLY THE UPPER TROUGH DEPARTS THIS
WEEKEND...SO THE FORECAST FOR THE END OF THE WEEKEND AND INTO EARLY
NEXT WEEK IS UNCERTAIN. EVEN WITH THIS UNCERTAINTY...THE GENERAL
IDEA OF BELOW NORMAL TEMPERATURES FOR THE WEEKEND AND INTO THE FIRST
PART OF NEXT WEEK SEEMS REASONABLE AS A HUDSON BAY HIGH BECOMES
STATIONARY AND LEADS TO DRY NORTHEASTERLY FLOW. PRECIPITATION
CHANCES WILL DEPEND ON THE NEXT UPPER TROUGH THAT LOOKS TO BE
LOCATED IN THE CENTRAL/SOUTHERN PLAINS AND AT THIS TIME MAY BE FAR
ENOUGH SOUTH TO KEEP THE AREA DRY.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 749 PM EDT MON APR 21 2014

GUSTY NW WINDS TO 25 KTS IN THE WAKE OF A COLD FRONT WILL DRAW MUCH
COLDER AIR AS WELL AS LOW CLOUDS INTO THE UPPER LAKES LATE THIS
EVENING AND OVERNIGHT. MVFR CIGS WILL ARRIVE FIRST AT KCMX AND KSAW
CLOSER TO MIDNIGHT AND THEN OVERNIGHT AT KIWD. ARRIVAL OF DRIER AIR
WILL RESULT IN CLOUDS CLEARING OUT AT KIWD LATE TUE MORNING OR EARLY
AFTN AND MID TO LATE AFTERNOON AT KCMX AND KSAW.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EDT MON APR 21 2014

IN THE WAKE OF A COLD FRONT CURRENTLY PASSING ACROSS LAKE
SUPERIOR...NW WINDS WILL INCREASE TO 15-30KT TONIGHT. STRONGEST
WINDS WILL BE IN A CORRIDOR FROM NCNTRL TO SCNTRL/SE LAKE SUPERIOR
WHERE SOME GALE FORCE GUSTS WILL PROBABLY OCCUR...MOSTLY IN THE
OVERNIGHT/EARLY TUE MORNING TIME PERIOD. THESE STONG WINDS WILL
DIMINISH FROM W TO E TUE INTO TUE EVENING AS A HIGH PRES RIDGE
ARRIVES. WINDS WILL FALL TO UNDER 15KT TUE NIGHT WITH LIGHT WINDS
LINGERING THRU AT LEAST WED MORNING AS HIGH PRES SLOWLY EXITS TO THE
E. OVER WRN LAKE SUPERIOR...NE WINDS WILL BE ON THE INCREASE WED
AFTN. AS ANOTHER LOW PRESSURE SYSTEM APPROACHES FROM THE PLAINS
LATER IN THE WEEK AND THE GRADIENT SHARPENS AGAIN...EASTERLY WINDS
WILL BE ON THE INCREASE THU. WINDS WILL THEN BACK AROUND TO THE N
FRI AS THE LOW PASSES ACROSS THE UPPER GREAT LAKES. DEPENDING ON THE
TRACK AND INTENSITY OF THIS LOW...THERE COULD SOME GALE FORCE
WINDS...POSSIBLY OVER WRN LAKE SUPERIOR AHEAD OF THE LOW AND THEN
OVER CNTRL AND ERN LAKE SUPERIOR AS THE LOW PASSES TO THE E.
&&

.HYDROLOGY...
ISSUED AT 409 PM EDT MON APR 21 2014

ANOTHER ABOVE NORMAL TEMPERATURE DAY WAS SEEN ACROSS UPPER MICHIGAN
TODAY...WITH HIGHS RISING INTO THE 50S TO LOWER 70S OVER MUCH OF
THE AREA. THESE WARM TEMPERATURES AND SUNSHINE HAS LIKELY LED TO
ANOTHER GOOD DAY OF MELTING IN THE AREAS THAT HAVE SNOW REMAINING.
STARTED TO SEE THE SECOND WAVE OF SNOW MELT RISES ON THE AREA
RIVERS YESTERDAY AND WILL CONTINUES TO SEE THAT INTO TONIGHT. BUT
COLDER TEMPERATURES EXPECTED TO ARRIVE ON TUESDAY SHOULD REALLY
SLOW THE MELT AND IN TURN LIMIT ADDITIONAL RISES. UNSETTLED WEATHER
WILL RETURN FROM THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. 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 AFTERNOON. 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. WE WILL CONTINUE TO REFINE
THE FCST AS THE TIME NEARS.

SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN
ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE
ONTONAGON RIVER...CRYSTAL FALLS/CRYM4/ ON THE PAINT RIVER...AND TO A
LESSER EXTENT THE HYDE/FRDM4/ ON THE FORD RIVER (WHICH APPEARS TO
HAVE BEEN FROM AN ICE JAM).

WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME...ALTHOUGH SOME
LOCATIONS MAY NEAR BANKFULL. 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...ROLFSON
LONG TERM...SRF
AVIATION...VOSS
MARINE...ROLFSON
HYDROLOGY...SRF






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