Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Text Only | 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 211003
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
603 AM EDT THU MAY 21 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 434 AM EDT THU MAY 21 2015

THE NEARING COLD FRONT/SFC TROUGH WILL BE A POSITIVE OVER THE
KEWEENAW PENINSULA...MOISTENING UP THE LOWER LEVELS BY SHIFTING
COOLER AIR INLAND FROM LAKE SUPERIOR. AT 3AM IT WAS 59F AT P59 WITH
28 PERCENT RH. THIS POOR RH RECOVERY HAS BEEN THE TREND ACROSS MUCH
OF THE W AND CENTRAL UP...BUT ESPECIALLY THE KEWEENAW PENINSULA AND
DOWNSLOPE AREAS NEAR LAKE SUPERIOR. ON THE OPPOSITE END OF THE
SPECTRUM...ISQ HAS BEEN IN THE FOG...WITH VIS DOWN TO 3/4SM SHORTLY
AFTER 3AM.

THE MAIN QUESTION TODAY WILL BE IF SHOWERS WILL BE ABLE TO DEVELOP S
CENTRAL THIS AFTERNOON ALONG THE E-W ORIENTED COLD FRONT/SFC
BOUNDARY SINKING ACROSS MOST OF THE CWA THIS MORNING...AND S CENTRAL
EARLY THIS AFTERNOON. FCST MODELS HAVE BEEN VERY CONSISTENT OVER THE
PAST COUPLE OF DAYS ON HAVING PRECIP ACROSS NE WI /ASSOCIATED WITH
PEAK HEATING AND LAKESHORE BOUNDARIES/. MUCH OF MENOMINEE COUNTY
LOOKS TO GET CLIPPED WITH LESS THAN 0.1IN. WOULD NOT BE SUPRISED IF
S MENOMINEE COUNTY POPS NEED TO BE INCREASED. WILL CONTINUE TO
MONITOR THE 06Z MODEL RUNS AS THEY COME IN...AND ADJUST AS NEEDED.

OTHERWISE...DRY AIR WILL BE UPON US. RH VALUES WILL FALL TO 25 TO 30
PERCENT IN THE TRADITIONAL LOCATIONS INLAND FROM THE COOLER N TO NW
AIR OFF LAKE SUPERIOR. THE STRONGEST WINDS WILL BE OVER THE E HALF
OF UPPER MI...WITH FUNNELING NW WINDS INCREASING GUSTS TO 20-25KTS
NEAR THE SOO. IT WILL BE ANOTHER COOL/DRY NIGHT AS THE NEXT ROUND OF
HIGH PRESSURE BUILDS IN FROM THE NW. TEMPERATURES SHOULD BOTTOM OUT
IN THE MID 20S TO MID 30S. WILL MENTION A FROST POTENTIAL INLAND
FROM THE GREAT LAKES.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 603 AM EDT THU MAY 21 2015

THE BEGINNING OF THE LONG TERM FORECAST PERIOD LOOKS FAIRLY QUIET AS
THE UPPER GREAT LAKES REGION STAYS IN A NORTHWESTERLY CONFLUENT FLOW
ALOFT ON WESTERN EDGE OF TROUGH CENTERED OVER EASTERN CANADA. AS A
RESULT...SFC HIGH PRESSURE WILL DOMINATE THE AREA THROUGH MUCH OF
THE WEEKEND KEEPING CONDITIONS DRY. SHORTWAVE ENERGY EJECTING NE
FROM MID-UPPER LEVEL TROUGH OVER THE WRN CONUS WILL PROVIDE A NEXT
BEST CHANCE FOR RAIN LATE WEEKEND/EARLY NEXT WEEK. MODELS HINT THAT
SERIES OF WEAKER NORTHERN STREAM SHORTWAVES COULD KEEP CONDITIONS
UNSETTLED INTO THE MIDDLE OF NEXT WEEK.

AS STATED PREVIOUSLY...SURFACE HIGH PRESSURE WILL LIKELY BE THE
DOMINANT FEATURE ACROSS AREA FROM FRIDAY INTO SUNDAY KEEPING
FORECAST GENERALLY DRY. CLIPPER SHORTWAVE GLANCING THE ERN EDGE OF
LAKE SUPERIOR TONIGHT WILL CONTINUE NORTHERLY FLOW INTO FRIDAY AS
THE CENTER OF THE SFC HIGH DESCENDS SOUTH FROM ONTARIO. HIGHS FRIDAY
WILL REMAIN COOLER THAN NORMAL...FROM LOWER TO MID 50S NCNTRL AND
EAST TO THE LOWER TO MID 60S WRN INTERIOR. TEMPS BY SATURDAY WILL
REBOUND TO ABOVE NORMAL VALUES (MAINLY LOWER TO MID 70S) AS HIGH
DEPARTS SOUTHEAST AND WSW FLOW STARTS TO DEVELOP.

GFS REMAINS MOST AGGRESSIVE OF OPERATIONAL 00Z MODEL SOLNS WITH
ARRIVAL OF SHORTWAVE ENERGY AND ASSOC WAA PCPN INTO THE UPPER GREAT
LAKES...ALTHOUGH IT MIGHT BE SHOWING SIGNS OF TRENDING TOWARD SLOWER
SOLNS OF NAM/CANADIAN AND ECMWF AS ALL MODELS NOW SHOW POSITION OF
PLAINS 5H RIDGE AXIS REMAINING WEST OF UPPER MI THROUGH AT LEAST SUN
MORNING. BIGGEST PROBLEM WITH GFS APPEARS TO BE OVERDONE MOISTURE
ADVECTION INTO AREA EVEN WITH ESTABLISHED RIDGE IN PLACE. 00Z GFS
RUN STILL WANTS TO BRING PCPN INTO THE SRN HALF OF THE FCST AREA SAT
NIGHT INTO SUN MORNING WHICH SEEMS ENTIRELY TOO QUICK GIVEN THAT 5H
RIDGE AXIS REMAINS WEST OF THE AREA. SEEMS MORE REASONABLE TO SIDE
WITH BLEND OF SLOWER ECMWF/CANADIAN/NAM SOLNS GIVEN BLOCKY PATTERN
IN PLACE ACROSS THE CONUS THROUGH THE WEEKEND. THUS...WL CONTINUE TO
DELAY BULK OF PCPN AND HIGHER POPS UNTIL AT LEAST SUN NIGHT INTO
MONDAY WHEN CONSENSUS OF OPERATIONAL MODELS AND ENSEMBLE SOLNS
INDICATE WRN CONUS SHORTWAVE ENERGY AND ASSOC SFC LOW PRESSURE WILL
LIFT INTO THE WRN GREAT LAKES. MODELS GENERALLY INDICATE BEST
INSTABILITY AND MID LEVEL LAPSE RATES STAYING SOUTH OF AREA THROUGH
PERIOD. ONLY CANADIAN AND GFS MODELS HINT AT GREATER INSTABILITY BY
MON AFTERNOON AS THEY SHOW SFC LOW TRACKING TO OUR WEST AND UPPER MI
PLACED IN WARM MOIST SECTOR AHEAD OF THE LOW...BUT PREFER TO SEE
THIS SIGNAL IN AT LEAST ONE MORE MODEL RUN BEFORE INSERTING THUNDER
IN FCST.  WEATHER MAY REMAIN UNSETTLED INTO THE MIDDLE OF NEXT WEEK
AS MODELS CONTINUE TO INDICATE POSSIBILITY FOR A SERIES OF WEAKER
NRN PLAINS SHORTWAVES TO MOVE ACROSS THE AREA AND BRING LIGHT SHRA
ACTIVITY INTO THE AREA.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 444 AM EDT THU MAY 21 2015

EXPECT INCREASED N TO NW WINDS TODAY BEHIND A COLD FRONT SINKING IN
FROM LAKE SUPERIOR TODAY. DESPITE THE FRONT A DRY AIR MASS WILL
PERSIST AT LOW LEVELS...RESULTING IN VFR CONDITIONS PREVAILING AT
KIWD/KCMX/KSAW THROUGH THIS FCST PERIOD. WINDS BEHIND THE FRONT
TODAY WILL BE GUSTY AT KSAW DUE TO FAVORABLE N WIND ENHANCED BY THE
LAKE BREEZE. OTHERWISE...WINDS WILL DIMINISH TONIGHT TO AROUND 5KTS
OR LESS AT ALL SITES AS HIGH PRESSURE BUILDS IN FROM THE NW.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 434 AM EDT THU MAY 21 2015

SW WINDS WITH GUSTS NEARING 30KTS WILL REMAIN POSSIBLE OVER THE W
HALF OF LAKE SUPERIOR EARLY THIS MORNING. A TROUGH ACROSS S LAKE
SUPERIOR WILL SINK TO CENTRAL LAKE MICHIGAN TODAY...AND THE OHIO
VALLEY OVERNIGHT...WITH NW WINDS OVER THE E THIRD OF LAKE SUPERIOR
GUSTING TO AROUND 25KTS THIS AFTERNOON INTO EARLY THIS EVENING. HIGH
PRESSURE OVER N MANITOBA THIS MORNING WILL SLOWLY SINK ACROSS THE
UPPER GREAT LAKES OVERNIGHT...AND EXIT TO THE OHIO VALLEY FRIDAY
NIGHT. THIS WILL LEAVE A RIDGE ACROSS LAKE SUPERIOR THROUGH SUNDAY.
EXPECT  LOW PRESSURE OVER THE CENTRAL AND SOUTHERN PLAINS SUNDAY
MORNING TO DEEPEN ACROSS S MN AND IA BY DAYBREAK MONDAY...AND W LAKE
SUPERIOR DURING THE DAYTIME HOURS MONDAY.
&&

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

$$

SHORT TERM...KF
LONG TERM...VOSS
AVIATION...KF
MARINE...KF



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