Area Forecast Discussion
Issued by NWS Duluth, MN

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000
FXUS63 KDLH 200531
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
1131 PM CST WED NOV 19 2014

.UPDATE...
ISSUED AT 854 PM CST WED NOV 19 2014

SNOW SHOWERS CONTINUED THIS EVENING...MOST NUMEROUS OVER AND NEAR
FAR WESTERN LAKE SUPERIOR AND ALONG THE SOUTH SHORE OF LAKE
SUPERIOR. WE UPDATED GRIDS TO ACCOUNT FOR THE LATEST RADAR
TRENDS...LINGERING THE SNOW SHOWERS EVEN LONGER INTO THE NIGHT.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 348 PM CST WED NOV 19 2014

COLD AND SNOWY PATTERN CONTINUES TODAY INTO TONIGHT AS A CLIPPER
SYSTEM MOVES SOUTH INTO THE REGION. MAIN CONCERN FOR THE FORECAST
WAS SNOW SHOWERS TODAY AND LAKE EFFECT SNOWFALL TONIGHT.

TODAY...OFF AND ON SHOWERS WERE A BIT MORE PERSISTENT THAN
ORIGINALLY EXPECTED...WITH SOME INTENSE SHOWERS BRIEFLY REDUCING
VISIBILITY TO A MILE OR LESS AT TIMES. ACCUMULATION WAS UP TO AN
INCH IN MOST SPOTS. WINDS WERE GUSTY AT TIMES WITH 25-35 KT WINDS
MIXING DOWN DUE TO STEEP LOW LEVEL LAPSE RATES. SKIES WERE MOSTLY
CLOUDY.

TONIGHT...WHILE SNOW SHOWERS END ACROSS MOST OF NORTHERN MN AND
NORTHWEST WI LAKE EFFECT SNOWFALL WILL RAMP UP ALONG THE SOUTH SHORE
OF LAKE SUPERIOR...ESPECIALLY ALONG THE GOGEBIC RANGE NEAR THE
WISCONSIN/MICHIGAN BORDER. CONDITIONS ARE VERY GOOD FOR LAKE EFFECT
SNOWFALL...WHILE WIND DIRECTION IS A BIT MORE WESTERLY THAN IDEAL
FOR GOOD FETCH LENGTH...LAKE TEMP OF AROUND 5 C /40 F/ AND 850 MB
TEMPS OF -20 WILL RESULT IN UPWARDS OF 500 J/KG OF LAKE-INDUCED
CAPE. SNOW AMOUNTS OF 4 TO 7 INCHES ARE EXPECTED...AND WOULD NOT BE
SURPRISED TO SEE A FEW SPOTS RECEIVE UP TO 10 INCHES DEPENDING ON
WHERE THE BEST BANDS SET UP. ELSEWHERE...OFF AND ON SNOW SHOWERS
SHOULD DISSIPATE AFTER MIDNIGHT. OVERNIGHT LOWS IN THE SINGLE
DIGITS...BELOW ZERO ACROSS THE ARROWHEAD REGION.

TOMORROW...LAKE EFFECT SNOW SHOWERS WILL WIND DOWN DURING THE DAY
AND SKIES EVERYWHERE WILL BE ON A CLEARING TREND AS THE SURFACE LOW
MOVES EAST AND HIGH PRESSURE BUILDS OVER THE NORTHERN PLAINS. WINDS
WILL WEAKEN AS THE SURFACE LOW MOVES EAST...OUT OF THE NORTHWEST AT
5 TO 10 KTS. THE AREA OF COLDEST AIR ALOFT WILL MOVE ACROSS THE CWA
ON THURSDAY AFTERNOON...AND EVEN WITH PLENTY OF SUNSHINE HIGH
TEMPERATURES WILL STRUGGLE TO REACH THE LOWER TEENS...AND REMAINING
THE IN THE SINGLE DIGITS /ABOVE ZERO/ ACROSS THE ARROWHEAD. THESE
HIGHS WILL APPROACH RECORD LOW MAX TEMPS...BUT DO NOT ANTICIPATE
ACTUALLY BREAKING ANY OF THE LOW MAX RECORDS.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 348 PM CST WED NOV 19 2014

THE FOCUS FOR THE EXTENDED PERIOD IS THE SURGE OF WARM AIR COMING
FOR THE WEEKEND AND THE NEXT POSSIBLE STORM SYSTEM EARLY NEXT WEEK.

THERE WILL BE A RAPID DE-AMPLIFICATION OF THE LONGWAVE TROF OVER
THE WESTERN GREAT LAKES AS THE UPPER FLOW BECOMES MUCH MORE ZONAL.
THIS FLOW BECOMES A S/WV WILL BE MOVING THROUGH THE FLOW AFTER IT
IS EJECTED FROM A TROF THAT IS DIGGING INTO THE PACIFIC NORTHWEST.
THIS TROF WILL BE AFFECTING HE NORTHLAND LATE IN THE WEEKEND/EARLY
IN THE WEEK.

BUT...FIRST...THE SFC HIGH PRESSURE RIDGE WILL SLIP ACROSS THE
REGION...SWINGING WINDS SOUTHERLY. THIS WILL TURN OFF THE LAKE
EFFECT SNOW OVER NRN WI. AND IT WILL BEGIN A PERIOD OF INTENSE WARM
AIR ADVECTION. FRIDAY MORNING STARTS OUT WITH 8H TEMPS OF -10 TO -16
WITH THE STRONG BAROCLINIC ZONE ACROSS NORTHEAST MN AND WESTERN
WISCONSIN. BY FRIDAY EVENING THE 0 DEGREE ISOTHERM WILL BE WELL INTO
NORTHERN WI.  THE WARM UP BROUGHT BY THIS AIR MASS WILL BE TEMPERED
BY THE THICK SNOW COVER AND CLOUDS...BUT TEMPS WILL BE BACK TO ABOUT
NORMAL. AS THE WARM AIR ARRIVES THERE WILL BE FREEZING DRIZZLE OVER
NORTH CENTRAL WI SATURDAY AS THERE WILL BE NO SEEDING FROM ABOVE THE
LOW LEVEL INVERSION...THEN AS SFC TEMPS WARM IT WILL CHANGE TO
DRIZZLE.

THE NEXT SYSTEM TO AFFECT THE NORTHLAND WILL BE ARRIVING
ON SUNDAY WHEN THE NRN STREAM TROF DIGS INTO THE MIDWEST. AS A
RESULT A SFC LOW WILL FORM AND MOVE ACROSS THE MIDWEST. AT THIS TIME
WE ARE LOOKING AT SOME ERRATIC MOVEMENTS AND NOT ALOT OF
CONSISTENCY FROM RUN TO RUN AND MODEL TO MODEL. BUT AHEAD OF THE
SYSTEM WE ARE STILL LOOKING FOR MIXED PCPN UNTIL COLDER AIR ARRIVES
SUNDAY NIGHT AND MONDAY. THIS SYSTEM DOES HAVE THE POTENTIAL OF
CAUSING SIGNIFICANT PRECIPITATION AND SNOW...BUT MUCH DEPENDS ON
FINAL LOW PATH AND PRECIPITATION TYPE CHANGEOVER.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1130 PM CST WED NOV 19 2014

SNOW SHOWERS CONTINUED IN SPOTS...PARTICULARLY FROM NEAR KHIB TO
KDLH INTO NORTHWEST WISCONSIN. MOST GUIDANCE SUGGESTS THESE SNOW
SHOWERS WILL DISSIPATE OVERNIGHT. OVERALL...THE TREND HAS BEEN FOR
THE SNOW SHOWERS TO DECREASE. SKIES HAVE CLEARED IN SPOTS...AND WE
EXPECT SCATTERED TO BROKEN CLOUDS FROM 3000-5000FT BUT DROP IN
SNOW SHOWERS.

CLOUDS WILL DECREASE FURTHER THROUGH THE DAY THURSDAY.

LAKE EFFECT SNOW SHOWERS WILL OCCUR ALONG THE SOUTH SHORE...MAINLY
TOWARD KIWD THROUGH THE PERIOD.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH   2  12   0  20 /  70   0   0   0
INL  -1  10  -5  23 /  70  10  10   0
BRD   2  14  -3  23 /  30   0   0   0
HYR   1  14  -6  21 /  60  10   0   0
ASX   6  15   0  22 /  90  60  10   0

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...LAKE EFFECT SNOW ADVISORY UNTIL 6 PM CST THURSDAY FOR WIZ004.

LS...SMALL CRAFT ADVISORY UNTIL 4 PM CST THURSDAY FOR LSZ121-145>148.

&&

$$

UPDATE...MELDE
SHORT TERM...MOORE
LONG TERM...CLC
AVIATION...MELDE







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