Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 270818
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
418 AM EDT FRI MAR 27 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 418 AM EDT FRI MAR 27 2015

HAVE BEEN CONTINUING THE TREND THAT STARTED YESTERDAY
EVENING...SLOWLY DIMINISHING LAKE EFFECT SNOW SHOWERS. AT THIS POINT
THE SNOW SHOWERS HAVE SHIFTED INLAND OVER THE N CENTRAL...WITH NO
NEW STRINGS OF SHOWER ACTIVITY NOTED ON THE SAT/RADAR IMAGERY. OVER
THE W IS A DIFFERENT STORY. THE LAST BATCH OF SNOW SHOWERS HAVE GONE
THROUGH CMX...DROPPING THE VIS DOWN TO 6SM TEMPORARITY. LOOK FOR THE
STEADY N WINDS TO KEEP THEM GOING DOWN W LAKE SUPERIOR. NEAR IWD THE
WINDS SHOULD BECOME MORE OUT OF THE NE TOWARDS
DAYBREAK...PUSHING/CONCENTRATING THE BANDS OVER N WI. WILL CONTINUE
TO MONITOR THE CLOUDS OVER ONTARIO...E OF LAKE SUPERIOR...FOR
FURTHER DEVELOPMENT. HOWEVER...WITH HIGH PRESSURE STRENGTHENING IT/S
GRIP ACROSS UPPER MI...LIMITED IF ANY ADDITIONAL DEVELOPMENT IS
EXPECTED.

UNDER THIS COOL HIGH PRESSURE...HIGHS TODAY WILL BE IN THE UPPER
TEENS TO NEAR 30F...WARMEST ALONG THE WI BORDER. IT LOOKS TO BE A
COLD NIGHT TONIGHT WITH LOWS IN THE SINGLE DIGITS BELOW AND ABOVE
ZERO...COLDEST WELL INLAND FROM THE GREAT LAKES. THE POTENTIAL
REMAINS FOR -10 TO -15F OVER IRON COUNTY.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 512 PM EDT THU MAR 26 2015

FAIRLY PROGRESSIVE WEATHER PATTERN SETTING UP OVER THE NRN CONUS
THROUGH MUCH OF THE EXTENDED FCST PERIOD. PERIOD WILL BE
CHARACTERIZED BY VERY COLD NIGHT FRI NIGHT FOLLOWED BY MODERATING
TEMPS ON SATURDAY AS A SHORTWAVE RIDGE BUILDS INTO THE UPPER LAKES.
WEATHER FROM SUNDAY INTO THURSDAY WL THEN BE HIGHLIGHTED BY A
MODERATE AND FAIRLY PROGRESSIVE PACIFIC FLOW WITH NEAR TO ABOVE
NORMAL TEMPS AS A SERIES OF SHORTWAVES MOVE THROUGH THE UPPER GREAT
LAKES BRINGING PERIODS OF MIXED PCPN.

BEGINNING FRI NIGHT...WITH THE SFC HIGH DRIFTING ACROSS THE
AREA...EXPECT A VERY COLD LATE MARCH NIGHT UNDER CALM WINDS AND A
VERY DRY AIR MASS (PRECIPITABLE WATER FCST UNDER ONE-TENTH OF AN
INCH). RECENT ADDITION OF NEW SNOW ON THE GROUND IN MANY AREAS WILL
FURTHER AID RADIATIONAL COOLING. WL FAVOR THE COLDEST END OF AVBL
MODEL GUIDANCE WHICH SUGGESTS MANY INTERIOR LOCATIONS SHOULD FALL
BLO ZERO AND SOME OF THE TRADITIONAL COLDEST SPOTS WL LIKELY FALL
INTO THE DOUBLE DIGITS BLO ZERO. GENERALLY FOLLOWED THE COLDER END
OF 12Z BIAS CORRECTED MODEL GUIDANCE...PARTICULARLY THE CANADIAN
MODEL WHICH TYPICALLY PERFORMS BEST DURING THESE IDEAL RADIATIONAL
COOLING NIGHTS.

SAT WILL BE SUNNY AND WARMER WITH TEMPS MOVING CLOSER TO NORMAL
ESPECIALLY W AND SCNTRL. SOUTHERLY WINDS WILL BEGIN TO INCREASE SAT
AFTERNOON...BUT MORE SO SAT NIGHT DUE TO TIGHTENING PRES GRADIENT
BTWN DEPARTING HIGH SLIDING TO THE SE AND SFC LOW PRES MOVING INTO
SRN MANITOBA/NW ONTARIO. EXPECT DOWNSLOPING AREAS ALONG LAKE
SUPERIOR WEST AND NCNTRL TO GET QUITE GUSTY OVERNIGHT WITH SSW WINDS
REACHING AOA 30 MPH. CONTINUED TO CARRY SLIGHT CHC POPS FOR LATE SAT
NIGHT FOR THE FAR WRN COUNTIES AS BOTH THE FASTER NAM AND GFS SOLNS
STILL HAVE SOME WAA PCPN SNEAKING IN FM WEST AHEAD OF APPROACHING
LOW PRES TROF. ECMWF AND CANADIAN CONTINUE TO BE SLOWER KEEPING THE
WEST DRY THROUGH 12Z SUN.

SUNDAY...THE LOW APPROACHING FM SCNTRL CANADA WILL BE ASSOCIATED
WITH A STRONG SHORTWAVE THAT WILL BE MOVING INTO THE UPPER LAKES.
THE GFS HAS THE DEEPEST SOLN INDICATING 170-200M 12 HR 500 MB HEIGHT
FALLS ACROSS THE AREA ASSOC WITH THE SHORTWAVE. THE
ECMWF/CANADIAN/NAM MODELS ALL KEEP BEST HEIGHT FALLS GENERALLY OVER
NRN LAKE SUPERIOR AND EAST OF UPPER MI. GENERALLY ALL MODELS AGREE
THAT BEST DYNAMICS AND DEEP LAYER Q-VECT CONV ASSOC WITH SHORTWAVE
WILL STAY NORTH OF LAKE SUPERIOR ALONG TRACK OF SFC LOW. STILL A
BRIEF PERIOD OF MODERATE ISENTROPIC ASCENT WILL SUPPORT PCPN
POSSIBLY AS EARLY AS LATE SAT NIGHT FOR WEST BUT MORE LIKELY SUNDAY
FOR MOST OF THE FCST AREA. MIXING RATIOS OF 4G/KG ARE AVBL ON THE
295K SFC (725-750MB)...SO THERE COULD BE A QUICK BURST OF DECENT
SNOWFALL MAINLY IN THE MORNING DURING THE SHORT-LIVED PEAK
ISENTROPIC ASCENT RANGING FROM HALF AN INCH WEST TO 1.5 INCHES EAST
WHERE BEST ISENTROPIC ASCENT IS LOCATED. AFTER THE INITIAL BURST OF
SNOW WITH THE STRONG ISENTROPIC ASCENT...ANY LIGHTER SNOW ESPECIALLY
BY SUN AFTERNOON SHOULD MIX WITH OR EVEN CHANGE TO RAIN FOR A TIME
UNDER DAYTIME HEATING...THEN CHANGE BACK OVER TO SNOW SUN NIGHT
UNDER WEAK CAA.

BIGGER STORY WITH THIS SYSTEM WL LIKELY BE GUSTY WINDS WITH EXPECTED
STRONG PRES FALLS NORTH OF LAKE ENHANCING DOWNSLOPE S-SW WINDS AHEAD
OF THE TROF ALLOWING FOR GUSTS TO REACH NEAR 40 MPH ALONG THE LAKE
SUPERIOR SHORE AND ERN COUNTIES. S-SW WINDS COULD ALSO APPROACH 40
MPH ALONG PORTIONS OF LAKE MI AS WELL AS S-SW WINDS FUNNEL ACROSS
THE LONG AXIS OF THE LAKE. WINDS WILL SHIFT NW BEHIND LATE SUNDAY
INTO SUNDAY NIGHT AND REMAIN FAIRLY GUSTY INTO SUN EVENING.

MAINLY DRY WEATHER WILL FOLLOW FOR MON AS A WEAK HIGH PRES RIDGE
MOVES ACROSS THE AREA. 12Z MODELS HINT AT ANOTHER WEAKER SHORTWAVE
MOVING THROUGH THE REGION MON NIGHT WHICH COULD BRING SOME LIGHT
PCPN TO THE AREA INTO TUE MORNING FOLLOWED BY ANOTHER DRY PERIOD TUE
AFTERNOON INTO TUE NIGHT AS ANOTHER SHORTWAVE RIDGE MOVES IN FM THE
WEST. BOTH THE ECMWF AND GFS INDICATE ANOTHER SHORTWAVE MOVING INTO
THE AREA FOR WED INTO THU AND DEPENDING ON THE TRACK/STRENGTH OF THE
SHORTWAVE THIS COULD BE A BETTER PCPN PRODUCER FOR THE REGION. THERE
WL BE PLENTY OF TIME YET FOR MODELS TO SORT OUT DETAILS/DIFFERENCES
BUT FOR NOW WL INCLUDE CHC POPS ACROSS MUCH OF CWA WED/THU.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY NIGHT)
ISSUED AT 418 AM EDT FRI MAR 27 2015

OTHER THAN INITIAL CLOUD COVER POSSIBLY LINGERING OVERHEAD AROUND 12Z
AT AT IWD...DO NOT EXPECT ANYTHING BELOW VFR CEILINGS/VIS FOR THE 3
TAF SITES THROUGH THE PERIOD AS HIGH PRESSURE SETTLES INTO THE
REGION. CLOSER TO THE HIGH PRESSURE SYSTEM...WINDS SHOULD REMAIN
BELOW 10KTS AT CMX AND IWD...AND DIMINISH TO LESS THAN 10KTS AT SAW
BY MID AFTERNOON. &&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 327 AM EDT FRI MAR 27 2015

THE NEXT STRONG PERIOD OF WINDS LOOKS TO BE LATE SATURDAY NIGHT
THROUGH SUNDAY NIGHT.

WINDS WILL CONTINUE TO WEAKEN AS HIGH PRESSURE CENTERED JUST NW OF
LAKE SUPERIOR THIS MORNING WILL DRIFT SLOWLY SE INTO THE LOWER GREAT
LAKES ON SATURDAY...AND THEN INTO THE MID ATLANTIC STATES ON SUNDAY.
LOOK FOR THE NEXT ROUND OF STRONGER WINDS WITH SW TO W GALES OF
35KTS /POSSIBLY AS HIGH AS 40KTS/ LATE SATURDAY NIGHT THROUGH
SUNDAY.

A LOW TRACKING ACROSS ONTARIO ON SUNDAY WILL DRAG A TROUGH ACROSS
THE UPPER GREAT LAKES. NW GALES TO 35KTS WILL LINGER OVER THE E HALF
OF LAKE SUPERIOR INTO SUNDAY NIGHT. EXPECT A RIDGE TO PASS ACROSS
THE UPPER GREAT LAKES ON MONDAY. ANOTHER LOW WILL THEN TRACK SE
ACROSS THE GREAT LAKES REGION MONDAY NIGHT THROUGH TUESDAY.
&&

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

$$

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



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