Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 102307
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
707 PM EDT THU APR 10 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 351 PM EDT THU APR 10 2014

A STRONG 972MB SFC LOW OVER NRN JAMES BAY IS CONTRASTED BY A 1015MB
HIGH OVER THE CENTRAL PLAINS THIS AFTERNOON. ADDITIONALLY...A VORT
MAX IS CURRENTLY MOVING THROUGH THE NRN CWA. THE RESULT HAS BEEN
GUSTY WNW WINDS TODAY...WITH RECENT GUSTS OF 41KTS/48MPH AT CMX
BEING THE HIGHEST RECORDED SO FAR TODAY AS THE VORT IS OVERHEAD.
GIVEN JUST ISOLATED GUSTS ABOVE WIND ADVISORY CRITERIA OVER THE
KEWEENAW...KEPT THE SPS GOING FOR THE WINDS INSTEAD OF ISSUING AN
ADVISORY. MOST OF THE CWA HAS SEEN CLEAR SKIES FOR A GOOD PORTION OF
THE DAY AS THE AIRMASS OVERHEAD IS QUITE DRY. THE DRY MID LEVELS AND
GOOD MIXING TO AROUND 800MB HAS RESULTED NOT ONLY IN THE WINDS BUT
ALSO DEW PTS IN THE LOW TO MID 20S IN MOST LOCATIONS...COMBINING
WITH TEMPS IN THE MID 40S /JUST DOWNWIND OF LAKE SUPERIOR/ TO THE
UPPER 50S /INLAND/ TO PRODUCE RH VALUES OF 20-30 PERCENT IN WARMER
AREAS.

LOW TEMPS TONIGHT LOOK TO BE FROM NEAR 32F TO THE MID 20S INLAND.
CLOUDS WILL BE ON THE INCREASE OVER THE W TONIGHT AHEAD OF A
SHORTWAVE SET TO MOVE TO W OF THE CWA BY LATE TONIGHT. NO PRECIP IS
EXPECTED TONIGHT.

THE SHORTWAVE IS SET TO MOVE ACROSS THE AREA ON FRI...LEADING TO
STEEP MID LEVEL LAPSE RATES OF 7-8C/KM AND MLCAPE VALUES UP TO
100J/KG. THIS WILL BE SUFFICIENT TO SUPPORT ISOLATED TO SCATTERED
RAIN SHOWERS DURING THE DAY FRI. GIVEN THAT PRECIP WILL BE
CONVECTIVE IN NATURE...EXACT QPF AMOUNTS ARE DIFFICULT TO
PREDICT...BUT GENERALLY HAVE LESS A TENTH OF AN INCH. THINK THAT
MODELS MIGHT BE A BIT OVERDONE WITH QPF AMOUNTS UP TO A QUARTER INCH
GIVEN VERY DRY LOW LEVELS TO START THE DAY THAT WILL TAKE TOP DOWN
SATURATION TO OVERCOME. AS FAR AS MODEL AGREEMENT...DID NOT USE MUCH
OF THE NAM SOLUTION IN THE FORECAST AS IT WAS 6 HOURS FASTER THAN A
MAJORITY OF OTHER WELL AGREEING MODELS.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 419 PM EDT THU APR 10 2014

DURING THE LONG TERM....THE PATTERN WILL BRIEFLY RETURN TO ONE THAT
WAS COMMON DURING THE WINTER. A RIDGE BUILDING ALONG THE W COAST OF
NAMERICA THIS WEEKEND WILL FORCE A SHARP...DEEP TROF TO DEVELOP S
THRU THE CNTRL AND GREAT LAKES REGION. THIS AMPLIFIED PATTERN
WILL LIKELY YIELD HVY PCPN ALONG STRENGTHENING SFC FRONTAL BOUNDARY
ASSOCIATED WITH THE TROF DUE TO THE DEVELOPING TIGHT THERMAL
GRADIENT FROM WARM MOIST AIRMASS FEEDING N FROM THE GULF OF MEXICO
AND THE LATE SEASON ARCTIC AIR MASS HEADING S INTO THE CNTRL
CONUS/GREAT LAKES REGION. THERE IS STILL SOME UNCERTAINTY IN WHETHER
OR NOT UPPER MI GETS BRUSHED BY MDT/HVY PCPN...BUT MOST MEDIUM RANGE
MODELS SUGGEST THE FRONTAL BOUNDARY WILL SLIP TOO FAR S AND E BEFORE
THE MDT/HVY PCPN REALLY TAKES OFF IN THE VCNTY OF THE FRONT. WITH
THE UPCOMING PATTERN AMPLIFICATION...NEAR NORMAL TO SLIGHTLY BLO
NORMAL TEMPS WILL START THE LONG TERM ON SATURDAY BUT WILL
TRANSITION POTENTIALLY TO WELL BLO NORMAL EARLY NEXT WEEK. SLOW
MODERATION SHOULD THEN OCCUR BY THE END OF NEXT WEEK AS SPLIT FLOW
PATTERN TAKES SHAPE AND THE ERN CONUS TROF RETREATS INTO ERN
CANADA.

BEGINNING FRI NIGHT...PRIOR TO THE ONSET OF PATTERN AMPLIFICATION
THIS WEEKEND...MODELS SHOW A SHORTWAVE AND ASSOC FRONTAL BOUNDARY
TRACKING ESE INTO THE UPPER LAKES LATE FRI AFTERNOON/FRI EVENING
WHICH COULD SUPPORT SCT -SHRA INTO FRI EVENING UNDER STEEP MIDLEVEL
LAPSE RATES OF 7-8C/KM AND MLCAPE VALUES LESS THAN 100J/KG. AS THE
FRONTAL BOUNDARY EXITS AND WEAK RDGG ALOFT MOVES IN BEHIND THE
SHORTWAVE...LOOK FOR DRY CONDITIONS OVERNIGHT FRI NIGHT.

AS THE UPR TROF BEGINS TO AMPLIFY S INTO THE ROCKIES/WRN PLAINS
SAT...A BROAD SFC LOW PRES TROF WILL DEVELOP AHEAD OF IT OVER THE
PLAINS. A SHORTWAVE FCST TO MOVE ACROSS THE NRN PLAINS TOWARD THE
UPPER LAKES/NRN ONTARIO. STRENGTHENING WAA/ISENTROPIC ASCENT AS
NOTED ON 295K SFC AHEAD OF A SHORTWAVE MOVING FROM THE NRN PLAINS
INTO THE UPPER GREAT LAKES WILL SPREAD AN ORGANIZING AREA OF PCPN
FROM THE NRN PLAINS/UPPER MISSISSIPPI VALLEY INTO THE UPPER GREAT
LAKES. GIVEN INCREASING MOISTURE AND ASCENT...WILL CONTINUE THE
LIKELY TO CATEGORICAL POPS SPREADING W TO E DURING THE DAY SAT.

12Z GFS HAS NOW BACKED OFF ON ITS COLDER SOLN AND NOW MOST MODELS
POINT TOWARD RAIN BEING THE DOMINANT PCPN TYPE ON SAT. THE UKMET
STILL SHOWS THE POTENTIAL FOR SNOW TO MIX WITH RAIN OVER THE NW CWA
WITH THE SHARPER FRONTAL BOUNDARY SET UP S OF UPPER MI SAT. WITH
EASTERLY WINDS...WILL STILL MAINTAIN GENERALLY COOLER TEMPS OF PREV
FCST. TEMPS MAY NOT GET OUT OF THE 30S N AND NEAR LAKE MICHIGAN.
MODELS STILL SHOW SOME ELEVATED INSTABILITY OF A FEW HUNDRED J/KG
NOSING N...KEPT A MENTION OF SCHC THUNDER SCNTRL SAT AFTN/EVENING.

PCPN WILL WIND DOWN AND END IN MOST AREAS SAT NIGHT AS SHORTWAVE
PASSES TO THE E AND NE AND ASSOCIATED COLD FRONT EXITS TO THE E AND
SE. THE RAIN MAY MIX WITH OR CHANGE TO LIGHT SNOW/FLURRIES AS IT
DIMINISHES/ENDS UNDER CAA REGIME. SUNDAY SHOULD BE DRY AT LEAST
THROUGH MOST OF THE DAY.

LATE SUNDAY INTO MONDAY...BIG QUESTION FOR THIS PERIOD IS WHETHER
PCPN WILL OCCUR...AND IF SO...HOW MUCH OVER THE CENTRAL AND ERN
FCST.  BOTH THE GFS AND ECMWF ADVERTISE A SHORTWAVE RIDING ALONG
FRONTAL BOUNDARY FROM THE SRN PLAINS INTO THE GREAT LAKES REGION
SUNDAY NIGHT INTO MONDAY. THE 12Z GFS HAS NOW TRENDED BACK FARTHER
NORTH AND WEST WITH PCPN BRINGING AT LEAST A QUARTER INCH OF PCPN
INTO MAINLY THE SCNTRL AND ERN FCST AREA FOR LATE SUNDAY INTO SUNDAY
NIGHT. THIS PCPN APPEARS AT FIRST GLANCE TOO FAR NORTH GIVEN THAT
THE SFC-8H FRONTAL BOUNDARY STRETCHES FROM NRN IL INTO SRN LOWER MI.
LOOKING AT THE 290-295K ISENTROPIC SFCS FROM BOTH THE GFS AND
ECMWF...THE BEST ISENTROPIC ASCENT ALSO STAYS WELL S AND E OF UPPER
MI. MY FIRST IMPRESSION IS TO DISCOUNT THE 12Z GFS AND AFT LOOKING
AT THE 12Z ECMWF WILL LEAN AWAY FROM THE GFS AND KEEP CLOSER TO MORE
CONSISTENT ECMWF SOLN WHICH ALSO AGREES FAIRLY WELL WITH PREV FCST.
WILL KEEP CURRENT LOW CHC POPS FOR LIGHT SNOW IN FCST FOR CENTRAL
AND ERN CWA WITH THE POTENTIAL FOR THESE COUNTIES TO BE AFFECTED BY
THE FAR NRN FRINGE OF THE PCPN SHIELD.

ON TUE...MODELS INDICATE THAT A SHORTWAVE MAY DROP THRU THE AREA AND
GENERATE -SHSN. MID APRIL DAYTIME HEATING/DESTABILIZATION WOULD
FURTHER AID -SHSN DEVELOPMENT. MAY NEED TO INTRODUCE CHC POPS OVER
THE INLAND PORTIONS OF WRN FCST AREA.

WED LOOKS DRY WITH HIGH PRES SETTLING OVER THE AREA AND TUE NIGHT
WILL LIKELY BE COLDEST NIGHT OF FCST PD WITH SFC HIGH PRES OVERHEAD
AND CLEAR SKIES. WAA AHEAD OF SYSTEM DEVELOPING OVER THE PLAINS
COULD BRING IN A CHC OF SNOW/RAIN TO MAINLY THE WEST HALF OF CWA ON
THU AFTERNOON.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 705 PM EDT THU APR 10 2014

CLOSER APRCH OF HI PRES/LOSS OF DIURNAL HEATING WL CAUSE QUICKLY
DIMINISHING WINDS THIS EVNG. ALTHOUGH THE CLOSER APRCH OF A LO PRES
TROF ON FRI IN THE PRESENCE OF DAYTIME HEATING WL BRING SOME DIURNAL
CLDS/PERHAPS SOME -SHRA TO MAINLY IWD AND SAW...OVERALL DRYNESS OF
THE LLVLS WL RESULT IN VFR CONDITIONS THRU THE ENTIRE FCST PERIOD AT
ALL 3 SITES.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EDT THU APR 10 2014

A LOW PRES SYSTEM NEAR JAMES BAY WILL MOVE EAST INTO QUEBEC THIS
EVENING AS W-NW WINDS TO 30 KNOTS EARLY THIS EVENING SUBSIDE. BEHIND
THE EXITING LOW  A WEAK HIGH PRESSURE RIDGE WILL SLIDE THROUGH THE
GREAT LAKES REGION TONIGHT AND LEAD TO WINDS FALLING BELOW 15KTS.
THESE LIGHTER WINDS WILL CONTINUE THROUGH FRIDAY NIGHT EVEN THOUGH A
WEAK SURFACE TROUGH MOVES THROUGH THE UPPER GREAT LAKES FRIDAY
AFTERNOON/EVENING. AN ELONGATED SURFACE TROUGH WILL MOVE INTO THE
GREAT LAKES REGION THIS WEEKEND FROM A LOW IN THE PLAINS STATES. THE
TROUGH WILL LIKELY ORIENT OVER NORTHERN LAKE MICHIGAN. THIS WILL
LEAD TO INCREASING NORTHEASTERLY WINDS ON SATURDAY...WITH SOME GUSTS
TO THE 25KTS RANGE OVER THE WESTERN LAKE. WINDS WILL REMAIN IN THE
15-25KT RANGE (SHIFTING TO THE N-NW ON SUNDAY) AS THE LOW PULLS OUT
OF THE SOUTHERN PLAINS AND MOVES THROUGH THE LOWER GREAT LAKES ON
MONDAY. WINDS WILL SUBSIDE BLO 20 KTS FOR TUE AND WED AS HIGH PRES
BUILDS ACROSS THE UPPER GREAT LAKES.
&&

.HYDROLOGY...
ISSUED AT 351 PM EDT THU APR 10 2014

A RIPE SNOW PACK AND TEMPERATURES ABOVE FREEZING FOR THE LAST
ROUGHLY 30 HOURS HAS LEAD TO A STEADY SNOWMELT ACROSS UPPER
MICHIGAN. FORTUNATELY...LIMITED RAINFALL AND TEMPERATURES ONLY IN
THE MID 40S TO UPPER 50S YESTERDAY THROUGH FRIDAY WILL KEEP THE
SNOWMELT SIMILAR TO NORMAL SPRING CONDITIONS. THEREFORE...WOULD
EXPECT A SLOW STEADY RISE IN RIVER LEVELS HEADING INTO THE
WEEKEND...BUT DON/T EXPECT ANY LARGER RIVERS TO RISE ABOVE BANKFULL
AT THIS TIME. RECEIVED A FEW REPORTS AND PICTURES OF SOME SMALL
CREEKS AND STREAM IN DELTA COUNTY NEAR OR OUT OF THEIR BANKS...BUT
NO SIGNIFICANT IMPACTS WERE NOTED. ALSO RECEIVED A REPORT OF ICE
COVERED BIG IRON RIVER BEGINNING TO BREAK UP NEAR SILVER CITY AS
WELL AS A COUPLE OF HINTS OF SMALL ICE JAMS ON A COUPLE OF
HYDROGRAPHS /PARTICULARLY THE ONTONAGON RIVER NEAR ROCKLAND AND FORD
RIVER NEAR HYDE...WITH THE ONTONAGON RIVER APPEARING TO BE THE MOST
SIGNIFICANT/. THIS ICE BREAK UP DOES LEAD TO SOME CONCERN FOR ICE
JAMS ON OTHER RIVERS ACROSS THE CWA...ESPECIALLY FOR RIVERS THAT
EMPTY INTO THE GREAT LAKES AND ENCOUNTER FROZEN MOUTHS.

A WEAK UPPER LEVEL DISTURBANCE WILL MOVE THROUGH ON FRIDAY...WHICH
MAY LEAD TO UP TO 0.15 INCHES OF RAIN...WITH THE BETTER CHANCES NEAR
THE WISCONSIN BORDER. THIS IS NOT EXPECTED TO SIGNIFICANTLY IMPACT
AREA RIVERS.

A LOW PRESSURE TROUGH MOVING THROUGH THE UPPER GREAT LAKES REGION
ON SATURDAY WILL LEAD TO PERIODS OF RAIN THROUGH SATURDAY EVENING.
THE CURRENT FORECAST CALLS FOR AMOUNTS TO BE IN THE 0.25-0.60 INCH
RANGE...BUT WITH COOLER TEMPERATURES ARRIVING WITH THIS RAIN...THE
IMPACT ON THE RIVERS SHOULD BE LIMITED. THEN...COLDER AIR SURGES
INTO THE GREAT LAKES REGION ON SUNDAY NIGHT AND REMAINS THROUGH THE
FIRST HALF OF THE WORK WEEK. THIS WILL SIGNIFICANTLY REDUCE OR EVEN
END THE SNOW MELT...AS HIGHS WILL ONLY BE IN THE 30S AND LOWS WILL
BE WELL BELOW FREEZING. SINCE 4-9 INCHES OF SNOW WATER EQUIVALENT
STILL REMAINS OVER PARTS OF WESTERN AND CENTRAL UPPER
MICHIGAN...THERE IS STILL PLENTY OF WATER AVAILABLE FOR THE SECOND
PERIOD OF SNOW MELT OVER THE NEXT COUPLE OF WEEKS.
&&

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

$$

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




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