Area Forecast Discussion
Issued by NWS Duluth, MN

Home | Current Version | Previous Version | Graphics & Text | 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 KDLH 251457 AAC
AFDDLH

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
957 AM CDT WED MAR 25 2015

.UPDATE...
ISSUED AT 956 AM CDT WED MAR 25 2015

OVERALL FORECAST FOR THE NEXT 12-18 HOURS IS PRETTY STRAIGHTFORWARD.
HOWEVER..PRECIP TYPE DETAILS AND TEMPS ARE GOING TO BE A BIG
CHALLENGE DURING THE DAY TODAY.

S/W TROF EJECTING THROUGH THE CENTRAL GRT LAKES REGION IS IN THE
PROCESS OF PHASING WITH CLOSED UPPER LOW CENTERED OVER NCENT MN
THIS MORNING. MID LEVEL DRY SLOT THAT HAD PUSHED NORTHWARD ALONG
THE I-35 CORRIDOR EARLIER THIS MORNING IS GETTING PINCHED OFF INTO
A VERY NARROW CORRIDOR FROM THE MN ARROWHEAD INTO NW WI AND SHOULD
BE MOSTLY GONE WITHIN THE NEXT FEW HOURS. DEEP LAYER FORCING FOR
ASCENT ASSOCIATED WITH THE MAIN UPPER LOW IS NOW SPREADING
EASTWARD. THIS PROCESS HAS RESULTED IN THE RE-INTRODUCTION OF
MID-UPPER LEVEL ICE CLOUDS..AND REDEVELOPMENT OF RATHER WIDESPREAD
LIGHT SNOW UNDERNEATH THE DEVELOPING MID LEVEL DEFORMATION ZONE
BISECTING THE DULUTH CWA FROM NW TO SE AT MID MORNING.

PRECIP EVOLUTION SHOULD BE FAIRLY STRAIGHTFORWARD AS THE UPPER LOW
MOVES STEADILY EASTWARD ACROSS NRN MN TODAY AND THIS EVENING..WITH
DEFORMATION ZONE PRECIP CONTINUING TO EXPAND IN COVERAGE WHILE
LIFTING SLOWLY NORTHWARD AND THE LINGERING THE LONGEST ACROSS FAR
NORTHERN MINNESOTA..MAINLY NORTH OF A LINE ROUGHLY FROM CASS LAKE
TO JUST NORTH OF DULUTH. PRECIP TYPE IS GOING TO BE A MAJOR
CHALLENGE DUE TO THE BORDERLINE BOUNDARY LAYER TEMPS AND
DEPTH..WHICH WILL BE COMPLICATED BY PRECIP RATES.

WITH THE DEPTH AND MAGNITUDE OF NEAR-SURFACE TEMPS AT..OR
CLIMBING JUST ABOVE FREEZING THIS AFTERNOON..PTYPE AT THE SURFACE
WILL LIKELY LARGELY BE DETERMINED BY THE PRECIP RATE AT ANY ONE
LOCATION. AREAS UNDERNEATH HEAVIER PRECIP BANDS WILL LIKELY REMAIN
MOSTLY OR ALL SNOW WITH DIABATIC COOLING KEEPING THE NEAR SURFACE
TEMPS JUST COLD ENUF FOR ICE TO REACH THE SURFACE. BUT..IN AREAS
UNDERNEATH LIGHTER PRECIP..PRECIP WILL LIKELY CHANGE TO LIGHT RAIN.
WE HAVE UPDATED THE FORECAST TO REFLECT MORE OF A SNOW OR RAIN
SNOW MIX FOR THE REMAINDER OF THE DAY..IN MOST AREAS. LOCALES
ACROSS THE NORTH COULD PICK UP ANYWHERE FROM 1-3 INCHES OF WET
SLUSHY ACCUMULATION..BUT WE EXPECT PRETTY MUCH EVERYWHERE
ALONG/SOUTH OF THE HIGHWAY 2 CORRIDOR TO SEE LITTLE ADDITIONAL
ACCUMULATION ABOVE WHAT HAS ALREADY OCCURRED..EXCEPT FOR PERHAPS ON
SOME GRASSY AREAS. THE UPDATED FORECAST ALSO REFLECTS SLIGHTLY
LOWER TEMPS ACROSS NRN MN FOR TODAY.

&&

.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 433 AM CDT WED MAR 25 2015

AN ACTIVE WEATHER PATTERN IN THE SHORT TERM WITH A WINTRY MIX TODAY
WITH LAKE EFFECT SNOW TONIGHT INTO TOMORROW. FIRST WAVE OF SNOWFALL
IS MOVING OUT EARLY THIS MORNING WITH AN INCH OF SNOWFALL RECEIVED
AT THE OFFICE. TODAY THE ATTENTION SHIFTS TO THE SFC LOW AT THE
NORTHWEST MN/NORTHEAST NORTH DAKOTA BORDER. THIS LOW WILL GRADUALLY
MOVE EAST ACROSS THE INTERNATIONAL BORDER TODAY WITH AN ASSOCIATED
COLD FRONT. TONIGHT A COLD FRONT WILL MOVE IN FROM THE NORTH AS A
COLDER AIRMASS PUSHES SOUTH FROM CANADA INTO THE NORTHERN PLAINS AND
UPPER MIDWEST THROUGH THE END OF THE WORK WEEK.

TODAY...CLOUDY...BREEZY...AND A MIX OF RAIN AND SNOW THROUGH THE
DAY. THE MAIN TWO CONCERNS TODAY ARE THE PRECIPITATION AND WIND.
STEEP LOW LEVEL LAPSE RATES COMBINED WITH AMPLE MOISTURE AND
LARGE-SCALE LIFT FROM THE SFC LOW GENERALLY ALONG/NORTH OF HIGHWAY 2
WILL PRODUCE RAIN/SNOW SHOWERS THIS MORNING INTO THE AFTERNOON.
EARLY THIS MORNING A DRY SLOT ALOFT IS CAUSING FREEZING
DRIZZLE/DRIZZLE IN PARTS OF NORTH-CENTRAL TO NORTHEAST MINNESOTA
BEHIND THE FIRST WAVE OF PRECIP...BUT WITH ROAD TEMPS ABOVE FREEZING
THERE WILL BE LIMITED IMPACTS FROM THIS DRIZZLE...ESPECIALLY AS SFC
TEMPS WARM UP THIS MORNING. PRECIPITATION TYPE THIS AFTERNOON WILL
BE MAINLY SNOW ALONG THE IRON RANGE...BUT FARTHER SOUTH SUCH AS THE
TWIN PORTS AND ACROSS NORTHWEST WISCONSIN EXPECT PRECIP TO CHANGE TO
RAIN AT TIMES DUE TO WARM LOW LEVELS. SHOULD SFC TEMPS BE COOLER
THAN CURRENTLY FORECAST WE COULD SEE JUST ALL SNOW...BUT
ROADS/SIDEWALKS WILL LIKELY SEE LITTLE TO NO ACCUMULATION. DO NOT
EXPECT ANYTHING BESIDES RAIN/SNOW/DRIZZLE TODAY SINCE THE ONLY WARM
LAYER THROUGHOUT THE COLUMN IS AT THE SFC. TOTAL SNOWFALL THIS
AFTERNOON COULD BE AN INCH OR TWO ALONG THE INTERNATIONAL
BORDER...BUT OTHERWISE LESS THAN AN INCH ELSEWHERE.

THE OTHER CONCERN TODAY WILL BE WIND IN THE SOUTHWEST PORTION OF THE
CWA...GENERALLY SOUTH OF A LINE FROM LEECH LAKE TO MOOSE LAKE. WINDS
IN THIS REGION WILL BE OUT OF THE WEST AND WINDY AT TIMES...15 TO 25
MPH WITH GUSTS TO 30 TO 40 MPH. ELSEWHERE BREEZY NORTHWEST WINDS OF
15 TO 20 MPH WITH GUSTS TO 30 MPH ARE EXPECTED IN THE
AFTERNOON...WITH WEAKER WINDS IN THE TIP OF THE ARROWHEAD.

TONIGHT...SNOW SHOWERS IN FAR NORTHEAST MINNESOTA AND NORTHWEST
WISCONSIN TAPERING OFF...WITH CLEARING SKIES AFTER MIDNIGHT.
SEASONABLE...LOWS IN THE TEENS ALONG THE INTERNATIONAL BORDER TO THE
LOW TO MID 20S ELSEWHERE. NORTH/NORTHWEST WINDS BREEZY AT TIMES IN
THE EVENING...10 TO 20 MPH...DIMINISHING AFTER MIDNIGHT.

THURSDAY...LAKE EFFECT SNOW SHOWERS ACROSS NORTHWEST WISCONSIN WILL
LEAD TO ONE TO THREE INCHES...WITH THE HIGHER TOTALS POSSIBLE ALONG
THE GOGEBIC RANGE IN NORTHERN IRON/ASHLAND COUNTIES. IN NORTHEAST
MINNESOTA SKIES WILL BE SUNNY WITH LIGHT NORTH W

.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 433 AM CDT WED MAR 25 2015

SFC HIGH PRESSURE WILL START OUT THE EXTENDED PERIOD...BUT THE NORTH
WINDS AND COLD AIR WILL KEEP SOME SNOW SHOWERS GOING OVER
NORTHWESTERN WI...WITH 8H TEMPS STARTING OUT BETWEEN -12 TO -14 BUT
WARM AIR ADVECTION ON THE RETURN FLOW BEHIND THE HIGH WILL QUICKLY
SHUT DOWN ANY LAKE EFFECT OVERNIGHT. ANOTHER STRONG UPPER LEVEL
SHORTWAVE TROF WILL BE AFFECTING THE NORTHLAND SATURDAY AND SUNDAY.
THE TROF WILL ENTER WRN MN BY SATURDAY EVENING AND BEGIN SPREADING
PRECIPITATION ACROSS MN THEN INTO WISCONSIN SUNDAY AS THE TRAILING
COLD FRONT MOVES THROUGH. PRECIPITATION TYPE IS IN QUESTION...THERE
WILL BE A STRONG SURGE OF WARM AIR AT LOWER LEVELS AHEAD OF THE
SYSTEM...AND MAY BE WARM ENOUGH THROUGH THE LAYER TO BEGIN AS
RAIN...THEN CHANGE TO SNOW AS THE COLD AIR ARRIVES WITH THE FRONT.
BUT SOME MAJOR DIFFERENCES IN TEMPERATURE PATTERN SHOWING UP...SO
WILL NEED TO WAIT TO GET BETTER HANDLE ON P-TYPE.  ONCE THIS WEEKEND
LOW MOVES OUT UPPER RIDGING WILL TAKE OVER UNTIL THE NEXT SHORT
WAVES MAKES AN APPEARANCE ABOUT MIDWEEK...WITH ANOTHER CHANCE OF
RAIN AND SNOW.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 633 AM  CDT WED MAR 25 2015

EXPECT IFR CONDITIONS THIS MORNING WITH CIGS BLO OVC010 WITH SOME
LINGERING LIGHT SNOW AND PATCHY DRIZZLE. THE LOWER CIGS RANGING
FROM HIGH IFR AND INTO MVFR WILL CONTINUE THROUGH THE FORECAST
PERIOD. WILL BECOME VERY WINDY ON THE BACK SIDE OF A RETREATING
LOW. WINDS WILL BECOME WESTERLY WITH GUSTS OVER 30 MPH
LIKELY. THE WINDS WILL GRADUALLY DECREASE LATE TONIGHT.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  39  21  30  11 /  80  40  10  10
INL  35  15  27   7 /  90  60   0   0
BRD  37  23  34  12 /  50  10   0   0
HYR  38  23  33  11 /  50  30  20  20
ASX  40  24  30  13 /  70  60  70  30

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 1 AM CDT
     THURSDAY FOR LSZ145-146.

     SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 1 AM CDT THURSDAY
     FOR LSZ121-147-148.

&&

$$

UPDATE...MILLER
SHORT TERM...JJM
LONG TERM...CLC
AVIATION...CLC







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