Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 021137
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
637 AM EST MON MAR 2 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM EST MON MAR 2 2015

00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPLIT FLOW OVER
NAMERICA WITH ARCTIC BRANCH TROF EXTENDING FM HUDSON BAY INTO THE
GREAT LKS. SHRTWV/AREA OF SOME LO/MID CLDS ASSOCIATED WITH SOME MSTR
BTWN H9 AND H7 SHOWN ON THE 00Z INL RAOB ARE PASSING THRU UPR MI
EARLY THIS MRNG. IN CONCERT WITH THE COLD NW LLVL FLOW E OF HI PRES
RDG SHIFTING INTO MN THAT IS ADVECTING H85 TEMPS AS LO AS -18C TO
-19C INTO THE AREA...SOME SCATTERED SN SHOWERS ARE IMPACTING UPR MI
DESPITE EXTENSIVE ICE COVER ON LK SUP. THE MOST NMRS SN SHOWERS
APPEAR TO BE OVER THE W TO THE S OF HOUGHTON AND OVER ALGER
COUNTY...LOCATIONS THAT ARE DOWNWIND OF WIDER BREAKS IN THE ICE
COVER OVER WRN LK SUP NEAR THE MN ARROWHEAD/E OF THE BAYFIELD
PENINSULA AND OVER AN AREA TO THE E OF THE KEWEENAW. LOOKING TO THE
NW...THERE IS A SHRTWV RDG WITHIN THE ARCTIC BRANCH MOVING E OVER
SCENTRAL CANADA SUPPORTING THE SFC HI MOVING INTO MN. 12HR H5 HGT
RISES UP TO 100-120M HAVE BEEN OBSVD UNDER THE NVA AHEAD OF THIS
FEATURE. WITHIN THE SRN BRANCH...THERE IS A CUTOFF LO MOVING OFF THE
PACIFIC INTO SRN CA.

MAIN FCST CONCERNS IN THE SHORT TERM ARE LES TRENDS INTO THIS MRNG
AND THEN ANTICIPATED CLRG WITH APRCH OF SHRTWV RDG/SFC HI PRES.
FOCUS FOR LATER TNGT WL SHIFT TOWARD POPS ASSOCIATED WITH DVLPG WAA
BTWN SFC HI PRES SHIFTING TO THE E AND FALLING MSLP TO THE W IN
ADVANCE OF SRN BRANCH SHRTWV LIFTING INTO THE PLAINS AND DEEPENING
ARCTIC BRANCH TROF INTO THE NRN PLAINS.

TODAY...WITH APRCH OF SHRTWV RDG AXIS/SFC HI PRES THIS MRNG...
MODELS SHOW H5 HGT RISES UP TO 180M BTWN 06Z-18Z. SHARPENING/
LOWERING SUBSIDENCE INVRN TO AOB 3K FT AGL AND INCRSGLY ACYC H925
FLOW SHOULD RESULT IN STEADY DIMINISHING TREND TO THE LES W-E WITH
ACTIVITY OVER THE E ENDING BY NOON. AS SKIES TURN MOSUNNY THIS AFTN
WITH RDG AXIS SHIFTING E ACRS THE CWA...EXPECT TEMPS TO TOP OUT IN
THE 20S WITH MIXING TO H85-875.

TNGT...AS SHRTWV RDG EXITS TO THE E...SFC HI PRES IS FCST TO DRIFT
INTO NEW ENGLAND. INCRSG SW FLOW BTWN THE DEPARTING HI AND FALLING
MSLP FM NW ONTARIO THRU THE PLAINS IN ADVANCE OF DIGGING SHRTWV THAT
WL BE DEEPENING THE ARCTIC BRANCH TROF IN SCENTRAL CANADA AND SHRTWV
LIFTING NE INTO THE PLAINS FM SRN BRANCH CUTOFF LO NOW OVER SRN CA
WILL BRING WAA/ISENTROPIC ASCENT BACK TO THE UPR LKS. THE MAJORITY
OF THE MODELS SHOW A BAND OF LGT PCPN UP TO 0.05 TO 0.10 INCH BY 12Z
NEAR THE WI BORDER WELL TO THE N OF H85 WARM FNT ASSOCIATED WITH SRN
BRANCH LO PRES CENTER FCST TO TAKE SHAPE IN THE CENTRAL PLAINS. THIS
BAND OF PCPN APPEARS TO BE RELATED TO HIER LVL FGEN IN THE H7-5 LYR
AND MID LVL MOISTENING WITH H7 SPECIFIC HUMIDITY FCST TO INCRS UP TO
2 G/KG BY 12Z. BUT POPS/PCPN AMNTS WL BE LIMITED BY LINGERING LOWER
LVL DRY AIR AS WELL AS PRESENCE OF SHARPER DEEP LYR QVECTOR STILL
FARTHER TO THE SW. GIVEN THE LINGERING LLVL DRY AIR AND FCST SHARPER
DYNAMIC SUPPORT/H85 WARM FNT/ISENTROPIC ASCENT TO THE SW...WENT NO
HIER THAN HI CHC POPS LATE NEAR THE WI BORDER ATTM. EXPECT THE
LOWEST MIN TEMPS OVER THE E CLOSER TO RETREATING HI PRES/CORE OF
DRIER AIR.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 331 AM EST MON MAR 2 2015

PRIMARY IMPACT IN THE LONG TERM WILL BE TUE AS MODERATE SNOW MOVES
THROUGH THE AREA.

AT 12Z TUE A NRN STREAM SYSTEM WILL BE OVER NRN MANITOBA WHILE A SRN
STREAM SYSTEM IS OVER THE CENTRAL PLAINS. LIGHT SNOW SHOULD BE
ONGOING LATE MON NIGHT INTO TUE MORNING...MAINLY OVER THE SRN/SWRN
CWA. SRN STREAM ENERGY STAYS MAINLY S OF THE CWA ON TUE AS THE NRN
STREAM SYSTEM MOVES INTO FAR NRN ONTARIO. GENERALLY MODERATE SNOW
WILL FALL ACROSS MOST OF THE REGION IN THE BROAD AREA OF
WAA/ISENTROPIC ASCENT ALONG WITH LARGER SCALE FORCING AS THE TROUGH
MOVES IN FROM THE W. SNOW RATIOS SHOULD BE BETWEEN    15-1 AND 18-1
AS TEMP PROFILES DO NOT SHOW THE DGZ BEING PARTICULARLY DEEP...BUT
DEEP ENOUGH TO KEEP RATIOS FROM BEING AS LOW AS 10-1. GENERALLY
PREFER A BLEND OF MODEL QPF FROM THE 00Z/02 GFS...12Z/01
ECMWF...00Z/02 NAM/NAM DNG...00Z/02 REGIONAL GEM AND 00Z/02 CONSALL.
THESE MODELS ARE IN GENERAL AGREEMENT ON QPF AMOUNTS...BUT THERE IS
STILL SOME DIFFERENCES...LIKELY DUE TO CHALLENGES OF SYSTEM PHASING.
PREFERRED MODEL BLEND GIVES QPF AMOUNTS OF 0.20-0.28
INCHES...RESULTING IN SNOWFALL AMOUNTS RANGING FROM AROUND 2.5
INCHES SCENTRAL TO 3-5 INCHES ELSEWHERE. LOOKING AT THE HIGHER END
OF PREFERRED GUIDANCE...QPF AMOUNTS UP TO 0.35 INCHES ARE NOT OUT OF
THE QUESTION...WHICH WOULD ALLOW FOR QPF AMOUNTS UP TO   5-6 INCHES.
THE LOW END OF PREFERRED GUIDANCE WOULD RESULT IN 2-3.5 INCHES OF
SNOW. LOOKING LIKE AN ADVISORY WILL BE NEEDED FOR TUE AS MOST OF THE
SNOW FALLS IN LESS THAN 12 HOURS DURING THE DAY AND CRITERIA IS 3-6
INCHES. WILL ALLOW THE DAY SHIFT TO TAKE ANOTHER LOOK AT THINGS
GIVEN VARIABILITY OF EXACT AMOUNTS AND PLACEMENT DUE TO COMPLEXITIES
OF SYSTEM PHASING.

WITH 850MB TEMPS AS WARM AS -9C ON TUE...SFC HIGH TEMPS WILL BE IN
THE MID TO UPPER 20S. ANOTHER COLDER PERIOD WILL FOLLOW THE PASSAGE
OF A STRONG COLD FRONT TUE AFTERNOON/EVENING AND A SECONDARY COLD
FRONT TUE NIGHT/WED MORNING. 850MB TEMPS WILL DECREASE TO A MINIMUM
OF -25C TO -30C WED INTO WED NIGHT. THIS WILL RESULT IN TEMPS
FALLING INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO BY LATE WED
MORNING...THEN INCREASING TO THE SINGLE DIGITS ABOVE ZERO DURING
PEAK HEATING WED AFTERNOON. SFC HIGH PRESSURE WILL START TO WORK
INTO THE AREA FROM THE W WED NIGHT...WHICH SHOULD ALLOW FOR VERY
COLD TEMPERATURES UNDER THE LINGERING COLD AIRMASS WITH LOWS WED
NIGHT FALLING TO AROUND -20 ALONG THE WI BORDER IN GOGEBIC AND IRON
COUNTIES. TEMPERATURE MODERATION WILL THEN OCCUR FRI THROUGH THE
WEEKEND.

WITH LAKE SUPERIOR NEARLY COMPLETELY ICE COVERED...LES
COVERAGE/INTENSITY IS SIGNIFICANTLY REDUCED...BUT SCATTERED LIGHT
LES IS EXPECTED TUE NIGHT INTO THU IN NW WIND SNOWBELTS. BLOWING
SNOW WILL BE AN ISSUE ALONG LAKE SUPERIOR AS WNW WINDS INCREASE
BEHIND THE COLD FRONTS...WITH GUSTS UP TO 40MPH POSSIBLE ALONG THE
SHORE LATE TUE INTO WED.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 637 AM EST MON MAR 2 2015

MVFR CIGS AT IWD WL GIVE WAY TO VFR CONDITIONS EARLY AS DRY HI PRES
MOVES INTO THE UPR GREAT LKS. OTRW...EXPECT VFR CONDITIONS TO
PREVAIL UNDER THE INFLUENCE OF THIS HI UNTIL AT LEAST LATE TNGT...
WHEN SOME -SN IN ADVANCE OF A LO PRES MOVING NE FM THE PLAINS WL
OVERSPREAD THE AREA. MVFR VSYBS ASSOCIATED WITH THIS PCPN MAY OCCUR
AFT 09Z AT IWD AND PERHAPS SAW IF LINGERING LLVL DRY AIR CAN BE
OVERCOME.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 AM EST MON MAR 2 2015

NW WINDS UP TO 30 KTS OVER EASTERN LAKE SUPERIOR EARLY WILL DIMINISH
QUICKLY THIS MORNING WITH ARRIVAL OF HI PRES RIDGE. LIGHT S WINDS
WILL THEN INCREASE UP TO 25 KTS ON TUE IN ADVANCE AN APPROACHING LO
PRES. ONCE THE LO PASSES TO THE E ON TUE NIGHT...TIGHTENING PRES
GRADIENT AND STRONG COLD AIR ADVECTION AHEAD OF ARCTIC HI PRES
MOVING INTO THE NORTHERN PLAINS WILL LIKELY BRING A PERIOD OF NW
GALES INTO WED. LATEST OFFICIAL ICE CONCENTRATION ON LK SUPERIOR IS
AROUND 95 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK...EXPECT
THE HIGHER ICE COVERAGE TO PERSIST AS TEMPERATURES STAY BELOW
FREEZING.
&&

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

$$

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


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