Area Forecast Discussion
Issued by NWS Duluth, MN

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000
FXUS63 KDLH 161445
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
945 AM CDT WED APR 16 2014

.UPDATE...
ISSUED AT 944 AM CDT WED APR 16 2014

THE SPRING STORM IS RAMPING UP THIS MORNING WITH SNOW ADVANCING
NORTH ACROSS THE MOST OF NORTHERN WISCONSIN AND AS FAR NORTH AS
HIGHWAY 2 ACROSS MINNESOTA. RADAR/OBSERVATIONS HAVE SHOWN MUCH OF
SOUTHWEST INTO CENTRAL MINNESOTA HAS FILLED IN WITH SNOW AS WELL.
STRONG LOW LEVEL WAA/LOW-MID LEVEL FGEN IN ADDITION TO STRONG
UPPER LEVEL DIVERGENCE WAS PROVIDING STRONG LIFT. THE 12Z NAM IS
NOT A WHOLE LOT DIFFERENT THAN THE 06Z RUN. WE STILL EXPECT HEAVY
SNOW TO FALL ACROSS PORTIONS OF THE NORTHLAND...WITH MUCH OF
NORTHERN WISCONSIN EXPECTED TO SEE THE HIGHEST AMOUNTS. FEW
CHANGES WILL BE MADE TO THE FORECAST THIS MORNING. IT MAY TAKE
AWHILE FOR THE SNOW TO MAKE IT UP INTO COOK COUNTY...AND MOST OF
THE SNOW FOR THAT AREA WILL FALL TONIGHT.

WINDS WILL BE INCREASING OVER LAKE SUPERIOR...AND AS THE AFTERNOON
PROGRESSES WE SHOULD SEE STRONG WINDS AT THE HEAD OF THE LAKE
WHICH WILL CAUSE CONSIDERABLE BLOWING AND FURTHER VSBY REDUCTIONS.
THE COMBINATION OF THE SNOW AND BLOWING MAY CREATE NEAR WHITE-OUT
CONDITIONS IN SPOTS AROUND THE TWIN PORTS LATE THIS AFTERNOON INTO
THE EVENING.

&&

.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 412 AM CDT WED APR 16 2014

THE MAJOR WINTER STORM IS THE MAIN FOCUS FOR THE SHORT TERM. THE
MODELS ARE COMING INTO BETTER AGREEMENT CONCERNING HEAVY SNOW THAT
WILL QUICKLY DEVELOP ACROSS THE NORTHLAND TODAY. SNOW WAS ALREADY
RAPIDLY DEVELOPING THIS EARLY MORNING. WHEN WE STARTED OUR SHIFT
AT MIDNIGHT...ALL THE PRECIPITATION WAS BASICALLY GOING INTO
SATURATING THE LOW LEVELS WITH NO SURFACE REFLECTION ON AREA
OBSERVATIONS. AS OF 4 AM...SNOW HAD BROKEN OUT ACROSS AN
INCREASINGLY LARGER AREA OF CENTRAL MN...WITH VSBYS NOW DOWN TO AS
LOW AS 3/4 MILE JUST SOUTH OF THE CWA. AREA RADARS SHOW PCPN
EXTENDING WESTWARD INTO THE DAKOTAS. TEMPERATURES RANGED FROM THE
SINGLE DIGITS IN THE TIP OF THE ARROWHEAD...TO THE LOWER 30S
AROUND THE KBRD AREA.

HIGH RESOLUTION SHORT TERM MODELS WERE GENERALLY DOING A DECENT
JOB AT PICKING UP THE GENERAL AREA AND TIMING OF THE CURRENT SNOW
AREA. WE SHOULD SEE SNOW CONTINUE TO BLOSSOM ON THE RADAR AS THE
MORNING WEARS ON WITH HEAVY SNOW BECOMING LIKELY ACROSS THE
SOUTHERN HALF OF THE CWA.

THE MAIN MODEL SOLUTIONS FROM 00Z HAD SLOWED THINGS DOWN A BIT
FROM PREVIOUS RUNS...A RESULT OF BEING DEEPER AND A BIT FURTHER TO
THE NORTH. THE MODEL RUN SNOW ACCUMULATION IS SHOWING SOME VERY
IMPRESSIVE AMOUNTS...AND THE SREF PLUMES CONTINUE TO TREND HIGHER
AS WELL. AS A RESULT...HAVE MADE SOME MINOR CHANGES TO HEADLINES
AND ALSO INCREASED SNOWFALL AMOUNTS IN MUCH OF THE SOUTH. HAVE
ADDED A FEW COUNTIES TO THE ADVISORIES...AND ALSO ISSUED A WARNING
FOR THE ARROWHEAD. THINK THEY COULD SEE SOME IMPRESSIVE AMOUNTS
MORESO TONIGHT AND ON THURSDAY...AS THE LOW WRAPS UP AND TAKES ON
MORE OF A NEGATIVE TILT. EASTERLY WINDS WILL NO DOUBT CONTRIBUTE
TO HIGHER AMOUNTS ALONG THE NORTH SHORE.

THE SREF PLUME MEAN VALUES NOW SHOW ABOUT 15 INCHES AT
DULUTH...WITH THE LOWEST MEMBER BEING AT ABOUT 8 INCHES. THE RUN
SNOW ACCUMULATION VALUES RANGE FROM 15 TO 20 INCHES ACROSS THE
SOUTHERN AND EASTERN PORTIONS OF THE CWA. WHILE THAT MAY BE A BIT
HIGH...THE TREND HAS DEFINITELY BEEN A BIT HIGHER. WITH INTENSE
FRONTOGENESIS...WE SHOULD SEE SNOWFALL RATES AT SOME POINT OF 1 TO
2 INCHES AN HOUR POSSIBLE. H3 DIVERGENCE IS ALSO IMPRESSIVE DUE TO
A COUPLED JET. OVERALL...WILL GO LITTLE TO NO SNOW AT
INTERNATIONAL FALLS...AND ROUGHLY 8 TO 14 INCHES OR A BIT MORE IN
SPOTS IN THE SOUTHEASTERN 1/3 TO HALF OF THE CWA. COULD SEE A BIT
OF A MIX IN FAR SOUTHEASTERN PORTIONS OF NW WI...BUT WILL GO WITH
MAINLY SNOW AT THIS POINT.

THE SNOW WILL DIMINISH FROM WEST TO EAST TONIGHT AND IN THE
ARROWHEAD ON THURSDAY.

.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 412 AM CDT WED APR 16 2014

THURSDAY NIGHT AND FRIDAY...HIGH PRESSURE WILL MOVE INTO THE
NORTHLAND IN THE WAKE OF THE EXITING STORM SYSTEM AFFECTING US
TODAY. THIS SHOULD PROVIDE A CLEARING TREND EARLY FRIDAY AND SUNNY
SKIES FOR MOST OF DAYTIME FRIDAY. THE SUNSHINE WILL WARM UP THE PINE
TREES WELL...SO I INCREASED HIGHS FOR AREAS WELL INLAND FROM LAKE
SUPERIOR. TEMPERATURES WILL BE ABOUT 10 DEGREES BELOW NORMAL.

THE WEEKEND...THE MODELS ARE IN POOR AGREEMENT CONCERNING
TIMING/PLACEMENT/AMOUNTS OF PCPN ASSOCIATED WITH A MID/UPPER LEVEL
TROUGH AND THAT WILL BE MOVING THROUGH SOUTH CENTRAL CANADA AND THE
AMERICAN NORTHERN PLAINS INTO THE NORTHLAND. THE GFS/NAM/SREF ARE
MUCH SLOWER THAN GEM AND ECMWF. I USED A WIDE BLEND FOR PCPN
CHANCES...BUT I LEANED ON THE SLOWER MODELS WITH THE THINKING THAT
IT WILL TAKE TIME TO SATURATE AIR IN THE RELATIVELY DRY CONDITIONS
IN THE REGION OF THE HIGH PRESSURE. DEPENDING ON THE TIMING AND
MOVEMENT OF THE TROUGH...SATURDAY OR SUNDAY COULD BE DRY AND SUNNIER
THAN FORECAST. FOR NOW...I HAD TO USE A BLEND THAT INCORPORATES BOTH
THE FASTER AND SLOWER MODELS. FOR THE MOST PART...THE PCPN APPEARS
TO BE RAIN. HOWEVER...I HAD TO ADD A MIX OF RAIN AND SNOW AT TIMES
IN CASE THE PCPN MOVES DURING THE COLDER TIMES EARLY IN THE MORNING.

EARLY NEXT WEEK...MUCH WARMER WEATHER IS EXPECTED TO START OFF THE
WORK WEEK MONDAY. HIGH PRESSURE SHOULD KEEP THE REGION DRY
MONDAY...BUT THERE COULD BE A STALLED FRONT THAT BEGINS TO LIFT AS A
WARM FRONT TUESDAY. THIS COULD BRING PCPN TO THE FORECAST AREA
TUESDAY AFTERNOON...AS SUGGESTED BY THE GFS. THE FRONT IS FARTHER
SOUTH IN THE ECMWF...AND KEEPS THE NORTHLAND MAINLY DRY FOR TUESDAY.
TEMPERATURES SHOULD BE NEAR NORMAL...HIGHS IN THE 50S AND LOW 60S.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 640 AM CDT WED APR 16 2014

A STORM SYSTEM WILL MOVE INTO NE MINNESOTA AND NW WISCONSIN TODAY.
SNOW WILL SPREAD INTO THE REGION FROM THE SOUTH THIS MORNING AND
THEN INTENSIFY THIS AFTERNOON. EAST TO ENE WINDS OF 15 TO 25 KNOTS
WILL DEVELOP ACROSS MUCH OF THE REGION BY THIS AFTERNOON. THE KDLH
AND KHYR AREAS WILL BE THE MOST AFFECTED...AND CAN EXPECT A
PROLONGED PERIOD OF MODERATE TO HEAVY SNOWFALL RATES...GUSTY
WINDS...AND LIFR CONDITIONS. THE NEXT MOST AFFECTED AREA WILL BE
KBRD...FOLLOWED BY KHIB. ALL OF THESE TERMINALS CAN EXPECT
IFR/LIFR CONDITIONS WITH LOW CIGS AND SIGNIFICANTLY REDUCED VIS
FROM SN AND BLSN.

THERE SHOULD BE SOME IMPROVEMENT TONIGHT TO IFR/MVFR CONDITIONS AS
THE SNOW BEGINS TO MOVE OUT OF THE REGION...AND ONLY LOW CLOUDS
LINGER. THE WINDS WILL BECOME NORTHERLY THIS EVENING AND THEN
GRADUALLY WEAKEN LATE TONIGHT.

THERE IS A LOW CHANCE THAT THE PCPN COULD SWITCH FROM SNOW TO RAIN
AT KHYR DURING THE AFTERNOON...BEFORE SWITCHING BACK TO SNOW THIS
EVENING. CONFIDENCE THAT THIS WILL HAPPEN THOUGH IS LOW SINCE
SURFACE TEMPERATURES ARE LIKELY TO ONLY REACH ABOUT 35
DEGREES...NOT QUITE WARM ENOUGH TO MELT THE FALLING SNOW TO RAIN
BEFORE IT HITS THE GROUND.

THE KINL AREA SHOULD NOT BE AFFECTED BY THIS STORM. THE GUSTY ENE
WINDS SHOULD DEVELOP THIS AFTERNOON...AND THEN BECOME NORTHERLY
THIS EVENING. I ADDED MVFR CIGS FOR LATE TONIGHT AS THE MODELS ARE
INDICATING LOW LEVEL SATURATION IN THE NORTHERLY FLOW...WHICH
COULD PRODUCE SOME MVFR CIGS.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  28  19  35  21 / 100 100  20  10
INL  34  14  37  17 /  10  10  10  10
BRD  32  21  38  23 / 100  50  10  10
HYR  32  24  38  17 / 100 100  20  10
ASX  31  23  36  19 / 100 100  50  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING UNTIL 4 AM CDT THURSDAY FOR MNZ033>036-038.

     WINTER WEATHER ADVISORY UNTIL 4 AM CDT THURSDAY FOR MNZ025-026.

     WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO NOON CDT
     THURSDAY FOR MNZ012-021.

     WINTER STORM WARNING UNTIL 10 AM CDT THURSDAY FOR MNZ020-037.

     WINTER WEATHER ADVISORY UNTIL 10 AM CDT THURSDAY FOR MNZ019.

WI...WINTER STORM WARNING UNTIL 4 AM CDT THURSDAY FOR WIZ006.

     WINTER STORM WARNING UNTIL 10 AM CDT THURSDAY FOR WIZ001>004-
     007>009.

LS...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THURSDAY FOR LSZ121-140>142-
     148.

     GALE WARNING UNTIL 4 AM CDT THURSDAY FOR LSZ143>147.

&&

$$

UPDATE...MELDE
SHORT TERM...DAP
LONG TERM...GROCHOCINSKI
AVIATION...GROCHOCINSKI






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