Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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 022102
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
402 PM 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 NIGHT THROUGH MONDAY)
ISSUED AT 402 PM EST MON MAR 2 2015

AT THE START OF THE LONG TERM PERIOD...UPPER MICHIGAN WILL SEE THE
SYNOPTIC PRECIPITATION QUICKLY COMING TO AN END OVER THE EASTERN
THIRD OF THE CWA. THIS IS DUE TO THE DRY MID LEVEL AIR MOVING OVER
THE AREA BEHIND THE COLD FRONT AND AHEAD OF THE MAIN SHORTWAVE
TROUGH THAT WILL MOVE THROUGH ON TUESDAY. THEN...AS COLDER AIR
SURGES INTO THE AREA...GENERALLY AFTER MIDNIGHT TUESDAY
NIGHT...SHOULD SEE THE POTENTIAL FOR LAKE EFFECT INCREASE FROM WEST
TO EAST. 850MB TEMPS WILL FALL FROM AROUND -11C AT 00Z WEDNESDAY
TO -26C AT 18Z WEDNESDAY...PROVIDING PLENTY OF OVER LAKE
INSTABILITY WHERE THERE IS OPEN WATER. THAT IS THE BIG QUESTION FOR
THE LAKE EFFECT FORECAST. VISIBLE SATELLITE SHOWS SEVERAL LARGER
AREAS OF OPEN WATER AND SLUSH OVER WESTERN...NORTH CENTRAL...AND
SOUTH CENTRAL LAKE SUPERIOR. THOSE AREAS HAVE NOT BEEN REPRESENTED
IN THE MODELS AT THIS POINT...SO I DON/T FEEL THE MODELS ARE
INDICATING THE LAKE EFFECT POTENTIAL IN THE QPF FIELDS.
THUS...HAVE PERFORMED SIGNIFICANT HAND EDITS TO THE GRIDS...BOTH IN
RAISING POPS AND HIGHLIGHTING AREAS DOWNWIND OF THE CURRENT OPEN
WATER AREAS. WITH THE STRONG WEST TO WEST-NORTHWEST WINDS TUESDAY
NIGHT INTO WEDNESDAY...THOSE AREAS OF OPEN WATER WILL LIKELY EXPAND
AND MOVE...SO THAT DOES INCREASE THE UNCERTAINTY OF THE LAKE EFFECT
SOME...BUT EVEN WITH THE COLD AIR...THINK THE WINDS WILL LIMIT THE
ICE COVER EXPANDING AT LEAST THROUGH WEDNESDAY. WHILE THE LAKE
EFFECT WON/T BE TOO STRONG INITIALLY TUESDAY NIGHT...THE CLOUD WILL
BE WITHIN THE DGZ AND LEAD TO A FLUFFY INCH OR SO OF ACCUMULATION.
THEN ON WEDNESDAY...INVERSION HEIGHTS WILL RISE TO 7-9KFT AS A
SHORTWAVE MOVES THROUGH AND SUPPORT MODERATE TO POTENTIALLY EVEN
LOCALLY HEAVY SNOWFALL. WITH THE COLD AIR BEING IN PLACE ON
WEDNESDAY...SNOWFLAKE SIZE SHOULD BE SMALL AND KEEP ACCUMULATIONS
IN THE COUPLE INCH RANGE FOR THE WEST-NORTHWEST WIND AREAS DOWNWIND
OF THE OPEN WATER. IN ADDITION...RECENT SNOWFALL AND THE STRONG
WINDS WILL LIKELY LEAD TO PATCHY/AREAS OF BLOWING SNOW...ESPECIALLY
OVER THE KEWEENAW AND NEAR LAKE SUPERIOR EAST OF MARQUETTE. WHEN
COMBINED WITH THE FINE FLAKED LAKE EFFECT SNOW...THIS WILL LEAD TO
VISIBILITIES BEING REDUCED BELOW 1 MILE AND IN THE STRONGER BANDS
LIKELY BELOW 1/2MI. FORTUNATELY...WITH WINDS MORE OUT OF THE WEST TO
WEST-NORTHWEST...THE IMPACT FOR AREAS EAST OF MARQUETTE WILL BE
FOCUSED MORE IN THE AREAS TO THE EAST OF MUNISING AND GENERALLY LESS
POPULATED AREAS.

HIGH PRESSURE RIDGE WILL BEGIN TO MOVE INTO THE AREA WEDNESDAY
NIGHT...DECREASING WINDS AND INCREASING SUBSIDENCE (LOWERING
INVERSION HEIGHTS). A WEAK SURFACE TROUGH MOVING OVER EASTERN LAKE
SUPERIOR AROUND MIDNIGHT WILL SHIFT WINDS MORE TO THE NORTHWEST FOR
A BRIEF PERIOD OF TIME BEFORE BACKING BACK TO THE WEST BY THURSDAY
AFTERNOON. WILL SHOW A GRADUALLY DECREASING TREND TO THE POPS FOR
THAT TIME PERIOD WHILE FOLLOWING THE WIND DIRECTIONS.

SHOULD SEE TEMPERATURES MODERATING BOTH ALOFT AND AT THE SURFACE
FRIDAY THROUGH THE WEEKEND AS 500MB FLOW BEGINS TO TURN A LITTLE
MORE WEST-NORTHWESTERLY. THIS SHOULD LEAD TO TEMPERATURES WARMING
TOWARDS MORE NORMAL VALUES FOR THIS TIME OF YEAR (INTO THE LOWER
30S). BUT THE CONFIDENCE ON PRECIPITATION OCCURRENCE IS LOW DUE TO
DIFFERENCES IN THE WAY THE MODELS HANDLE A COUPLE WAVES COMING ON
SHORE IN NORTHERN BRITISH COLUMBIA. THE 12Z GFS/GEM SLIDE THE WAVES
SOUTHEAST THROUGH THE AREA LATE FRIDAY NIGHT INTO SATURDAY...WITH
ANOTHER ONE ARRIVING ON SUNDAY. MEANWHILE...THE 12Z ECMWF SHOWS THE
WAVES BECOMING SEPARATED AND SPLITTING THE CWA THROUGH THE WEEKEND.
EITHER WAY WITH THE LIMITED DEEP MOISTURE...WOULDN/T EXPECT MUCH
MORE THAN LIGHT PRECIP ACCUMULATION THROUGH THE WEEKEND AND WILL
ONLY MENTION SLIGHT CHANCES.

A STRONGER SHORTWAVE LOOKS TO MOVE THROUGH THE AREA SUNDAY NIGHT
INTO MONDAY...LIKELY PULLING IN THE LAST SURGE OF COLD AIR FOR A
WHILE THROUGH THE AREA. EXPECT THERE TO BE SOME PRECIP ASSOCIATED
WITH THE SHORTWAVE...BUT THEN WITH WINDS TURNING NORTHERLY BETWEEN
THE DEPARTING SURFACE TROUGH AND A HIGH IN THE DAKOTAS...SHOULD SEE
A PERIOD OF LAKE EFFECT IN THE NORMAL SNOW BELTS. WITH THE FAVORABLE
850MB TEMPS (AROUND -14 TO -18C MONDAY)...WILL TREND POPS UP TO
MID/HIGH END CHANCES FOR NOW UNTIL WE ARE ABLE TO GET A BETTER
HANDLE ON THE ICE SITUATION ON LAKE SUPERIOR.

BEHIND THIS WAVE...GFS/ECMWF DETERMINISTIC AND ENSEMBLE MEMBERS ARE
SHOWING THE RIDGE THAT HAS BEEN PERSISTENT OVER THE WESTERN CONUS
AND ALASKA FOR THE LAST MONTH TO SHIFT EAST INTO THE CENTRAL CONUS
AROUND THE MIDDLE OF NEXT WEEK. THIS WILL LEAD TO TEMPERATURES
WARMING TO ABOVE NORMAL VALUES AND START MELTING SOME OF THE
SNOWPACK.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1240 PM EST MON MAR 2 2015

VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THIS AFTN/EVENING
UNDER DRY AIR MASS ASSOCIATED WITH HIGH PRES MOVING FROM THE MID
MISSISSIPPI VALLEY TO THE MID ATLANTIC STATES. LATE TONIGHT...SW
FLOW BTWN THE HIGH AND AN APPROACHING LOW PRES TROF WILL BRING A
RAPID INCREASE IN MOISTURE WHICH WILL LEAD TO SNOW DEVELOPMENT. AS
THE SNOW SPREADS NE...MVFR CONDITIONS SHOULD DEVELOP AT KIWD AROUND
09Z AND AT KCMX/KSAW AROUND 12Z. BY MID TO LATE MORNING...ALL
TERMINALS SHOULD SEE IFR CONDITIONS.
&&

.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...
  WINTER WEATHER ADVISORY FROM 7 AM EST /6 AM CST/ TO 7 PM EST /6
     PM CST/ TUESDAY FOR MIZ001>007-009>014-084-085.

LAKE SUPERIOR...
  GALE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY EVENING FOR
     LSZ264>267.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...KC


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