Area Forecast Discussion
Issued by NWS Duluth, MN

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000
FXUS63 KDLH 151817
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
117 PM CDT TUE APR 15 2014

.UPDATE...
ISSUED AT 110 PM CDT TUE APR 15 2014

HAVE MADE CHANGES TO THE WINTER WEATHER HEADLINES WITH AN UPGRADE
TO A WINTER STORM WARNING FOR ALL OF NW WI AND SECTIONS OF FAR
N-CENTRAL MN...INCLUDING PINE AND SOUTHERN AITKIN COUNTIES. HAVE
DECIDED TO LEAVE AREAS TO THE NORTH AND WEST IN A WATCH AT THE
MOMENT AND WILL MAKE A FINAL DECISION WITH THE AFTERNOON FORECAST
PACKAGE. HAVE SEEN A SOLID SHIFT TO THE SOUTH WITH THE MODEL
FORECAST TRACK OF THE SFC LOW AND THE SUBSEQUENT SWATH OF HEAVIEST
SNOW...SO MADE ADJUSTMENTS TO THE HIGHER SNOW AMTS EXPECTED. LOOKS
TO BE FROM AROUND HINCKLEY/GRANTSBURG...TO AROUND ASHLAND/IRONWOOD
AREA. UP TO 15 INCHES OF SNOW IS POSSIBLE ALONG THIS PATH. AREAS
TO THE SOUTH/SE AND NW OF THIS CORRIDOR WILL LIKELY SEE AROUND 6
TO 10 INCHES...AND DRAMATICALLY LESS OR EVEN NO SO FROM THE IRON
RANGE NWD. CHECK BACK FOR UPDATES.

UPDATE ISSUED AT 1255 PM CDT TUE APR 15 2014

UPDATED FOR 18Z AVIATION DISCUSSION BELOW.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 418 AM CDT TUE APR 15 2014

THE FOCUS IS ON A STORM SYSTEM WHICH COULD BRING HEAVY SNOW TO
PARTS OF THE FORECAST AREA LATE TONIGHT THROUGH WEDNESDAY
NIGHT...PRIMARILY THE SOUTHERN HALF OF THE FORECAST AREA.
CONFIDENCE IN SNOWFALL AMOUNTS...AND WHERE THE HEAVIEST SNOWFALL
WILL OCCUR...IS INCREASING. HOWEVER...SINCE THERE IS STILL SOME
DIFFERENCES IN THE TRACK AND TIMING IN THE MODELS...AND SINCE
THESE SPRING WINTRY WEATHER SYSTEMS CAN BE TRICKY WITH
TEMPERATURES AND MELTING/COMPACTING OF SNOWFALL...I DECIDED TO
MAINTAIN THE WINTER STORM WATCH. THE DAY SHIFT SHOULD HAVE A
BETTER ABILITY AT NARROWING DOWN THE DETAILS OF THIS STORM.

TODAY...COLD BUT SUNNY. HIGH PRESSURE IN THE NORTHERN PLAINS EARLY
THIS MORNING WILL SHIFT INTO THE NORTHLAND BY THIS AFTERNOON. THIS
SHOULD PROMOTE SUNNY SKIES FOR MUCH OF THE FORECAST AREA
TODAY...OR AT LEAST THE WESTERN TWO THIRDS. THE ARROWHEAD AND NW
WISCONSIN WILL PROBABLY SEE SOME SCATTERED CUMULUS IN THIS COOL NW
FLOW. IRON COUNTY IN NW WISCONSIN COULD SEE A LITTLE DUSTING FROM
LAKE EFFECT SNOW. HIGH TEMPERATURES WILL BE ABOUT 20 DEGREES BELOW
NORMAL FOR THIS TIME OF THE YEAR. MEANWHILE...A LOW PRESSURE
SYSTEM IN SE ALBERTA EARLY THIS MORNING WILL MOVE INTO THE
AMERICAN NORTHERN HIGH PLAINS AND STRENGTHEN/ORGANIZE TODAY. THIS
IS THE STORM SYSTEM THAT WILL BE AFFECTING THE NORTHLAND LATE
TONIGHT AND WEDNESDAY. THERE COULD BE SOME INCREASING HIGH CLOUDS
ACROSS THE WESTERN FORECAST AREA LATE THIS AFTERNOON AND EARLY
THIS EVENING BEFORE SUNSET IN ADVANCE OF THIS APPROACHING STORM
SYSTEM.

TONIGHT...THE MODELS ARE IN FAIRLY GOOD AGREEMENT THAT THE LOW
PRESSURE SYSTEM WILL MOVE TO THE SE SOUTH DAKOTA AREA BY LATE
TONIGHT. IT WILL BE ACCOMPANIED BY A SHORTWAVE THAT WOULD WILL
HAVE CROSSED THE PACIFIC NW AND ROCKIES TODAY. THE MODELS ARE
INDICATING THAT A BAND OF LOW/MID LEVEL FRONTOGENESIS WILL SET UP
NE OF THE LOW...AND WILL LIKELY BEGIN TO BRING SNOW INTO THE
WESTERN AND SOUTHERN FORECAST OVERNIGHT. HOWEVER...THE GEM IS
FASTER AND MORE SOUTH WITH THE SNOW THAN THE OTHER MODELS. THE NAM
IS MORE FOCUSED WITH THE SNOW BAND...AND IS PROBABLY PICKING UP
THE MORE NARROW BAND THAT THE FRONTOGENETICAL BAND WILL LIKELY
PROMOTE. THE ECMWF IS MUCH LIGHTER IN PCPN AND SNOWFALL AMOUNTS
THAN THE GFS/GEM/NAM. CONSIDERING ALL THIS...I LEANED ON A BLEND
OF THE NAM AND GFS.

WEDNESDAY...THIS IS WHERE THE MODELS BEGIN TO LOSE AGREEMENT WITH
THE TRACK AND TIMING OF THE MOVEMENT OF THE SURFACE LOW. THE ECMWF
AND GEM ARE SIGNIFICANTLY...ABOUT 3 TO 6 HOURS OR SO...SLOWER THAN
THE GFS AND NAM. HOWEVER...THE GENERAL TRACK SHOULD BE FROM SE
SOUTH DAKOTA TO SE MINNESOTA OR WEST CENTRAL WISCONSIN. THE GEM
AND ECMWF AND SLOWER WITH THE TRACK THAN THE GFS AND NAM. WHILE I
USED A BLEND FOR PCPN CHANCES AND AMOUNTS...I LEANED A LITTLE BIT
MORE ON THE GFS AND NAM. THE GFS AND NAM ARE INDICATING LOW/MID
LEVEL FRONTOGENESIS WILL LIKELY INTENSIFY ACROSS THE SE AND SOUTH
CENTRAL FORECAST AREA. DEPENDING ON WHERE THIS FRONTOGENETICAL
BAND SETS UP...IT COULD MEAN THE DIFFERENCE OF SEVERAL INCHES OR
MORE OF SNOW FOR ANY PARTICULAR PLACE IN THE FORECAST AREA...AND
THAT IT IMPLIES THERE COULD BE A SHARP CUTOFF IN SNOWFALL AMOUNTS.
THE NAM AND SREF INDICATE THERE COULD BE GOOD LIFT AND MOISTURE IN
THE DENDRITIC GROWTH ZONE...WHICH COULD PROMOTE HIGHER SNOWFALL
RATES AND AMOUNTS. SNOWFALL RATES IN THE STRONGER BAND THAT SHOULD
SET UP COULD EXCEED ONE INCH PER HOUR. THE NAM AND GFS ARE ALSO
SHOWING WARMER AIR ALOFT MOVING INTO THE SE FORECAST AREA DURING
THE AFTERNOON. THIS COULD RESULT IN SOME SNOW MIXED WITH RAIN...OR
EVEN JUST RAIN...FOR SOME AREAS...INCLUDING PHILLIPS...PARK FALLS
AND WINTER. THE RAIN COULD MELT SOME OF THE SNOWFALL ALREADY ON
THE GROUND AND CUT DOWN ON TOTAL STORM SNOWFALL. THERE WILL BE
INCREASING EAST TO NORTHWEST WINDS WEDNESDAY...ESPECIALLY NEAR
LAKE SUPERIOR. THE COMBINATION OF THE WIND AND HEAVIER SNOWFALL
RATES COULD CAUSE LOW VISIBILITY AT TIMES.

OVERALL...I STILL HAVE SOME CONCERNS ABOUT THE EXACT TRACK AND
TIMING OF THE SURFACE LOW...WHERE AND WHEN WILL THE FRONTOGENETICAL
BANDS SET UP...WHETHER THERE WILL BE ANY RAIN...AND WHETHER THE
ROADS WILL BE WARM ENOUGH TO MELT ANY SNOW AND CUT DOWN ON TOTAL
SNOWFALL AMOUNTS. THIS IS WHY I AM MAINTAINING THE WATCH...AND
HOPEFULLY THE WATCH WILL NARROW DOWN THE DETAILS EVEN MORE.
I AM GETTING MORE CONFIDENT THOUGH IN HIGHER SNOWFALL
ACCUMULATIONS. THE LOW TEMPERATURES TONIGHT ARE EXPECTED TO BE
WELL BELOW FREEZING. THE SNOW AND CLOUD COVER THEN MOVE IN LATE
TONIGHT. THIS SHOULD PREVENT MUCH WARMING WEDNESDAY...AND THE
ROADS COULD REMAIN COLD ENOUGH TO ALLOW PLENTY OF SNOW
ACCUMULATION...ESPECIALLY IF THERE IS THICK CLOUD COVER TO
INSULATE THE LOWEST LAYERS. AT THIS TIME...IT APPEARS MUCH OF THE
SOUTHERN FORECAST AREA COULD SEE 6 TO 12 INCHES. THE NORTHERN
FORECAST AREA COULD SEE LITTLE IF ANY SNOWFALL.

.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 418 AM CDT TUE APR 15 2014

THE LOW WILL CONTINUE TO MOVE NORTHEAST WEDNESDAY NIGHT AND WILL
BE IN THE NORTHERN GREAT LAKES BY THURSDAY MORNING. THE SNOW
WILL END WEST TO EAST ACROSS NW WI WITH AN ADDITIONAL 2-4 INCHES
EXPECTED BEFORE ENDING AFTER MIDNIGHT. THERE WILL BE SOME
LINGERING FLURRIES OR LIGHT SNOW ACROSS THE ARROWHEAD AND NW
THURSDAY MORNING BEFORE ENDING BY NOON IN THE WRAP-AROUND. AN AREA
OF HIGH PRESSURE WILL BUILD INTO THE FORECAST AREA THURSDAY
AFTERNOON AND MOVE EAST THROUGH SATURDAY. TEMPERATURES WILL BE
SLOWLY ON THE REBOUND WITH 40S BY SATURDAY. A SERIES OF SHORTWAVES
WILL MOVE THROUGH THE FORECAST AREA SATURDAY THROUGH MONDAY
BRINGING A CHANCE FOR RAIN DURING THE DAY AND A MIXTURE OF
RAIN/SNOW AT NIGHT. HIGH TEMPERATURES WILL BE IN THE 50S SATURDAY
INTO NEXT WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1255 CDT TUE APR 15 2014

FEW CONCERNS FOR THE FIRST 12 HOURS OF THIS AVIATION FORECAST
CYCLE. SURFACE RIDGE WILL TRANSLATE EASTWARD ACROSS NORTHERN
MINNESOTA WITH VFR CONDITIONS AND GENERALLY LIGHT/VARIABLE WINDS.
A FEW SCATTERED CLOUDS BETWEEN 4-6 KFT WILL AFFECT KHYR THRU
ROUGHLY 21Z.

RAPIDLY APPROACHING WINTER STORM WILL BEGIN TO INFLUENCE THE AREA
06-12Z TONIGHT WITH WINDS BECOMING EASTERLY AND STEADILY
INCREASING IN SPEED BY WED MORNING. HIGH LEVEL CLOUDS WILL RAPIDLY
THICKEN WITH LOWERING CEILINGS AS WELL. TIMING OF THE ONSET OF
SNOW IS SLIGHTLY SLOWER THAN THE PREVIOUS ISSUANCE..BUT WE STILL
EXPECT A DETERIORATION TO MVFR CONDITIONS AT KBRD 11-12Z AND
12-13Z AT KHYR. BOTH OF THOSE TAF SITES SHOULD SEE A FURTHER
LOWERING TO IFR IN MDT/HVY SNOW TOWARD THE END OF THIS TAF PERIOD.
KDLH SHOULD ALSO COME DOWN INTO MVFR RANGE WED MORNING WITH SNOW
DEVELOPING..ALONG WITH VERY STRONG AND GUSTY EAST WINDS
DEVELOPING OFF LK SUPERIOR BY 18Z WED. KINL/KHIB WILL SEE THE
GUSTY EAST WINDS..BUT ANY LIGHT SNOW SHOULD HOLD OFF AT KHIB UNTIL
AFTER 18Z..AND IT IS POSSIBLE KHIB/KINL MAY NOT SEE MUCH FROM THIS
STORM AT ALL.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  22  29  19  36 /  60 100  60  20
INL  15  34  14  37 /  10  10  20  10
BRD  26  31  21  38 /  80  80  30  10
HYR  21  31  24  38 /  70 100  80  20
ASX  20  31  23  36 /  50 100  80  30

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING FROM 4 AM WEDNESDAY TO 4 AM CDT THURSDAY
     FOR MNZ036-038.

     WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE WEDNESDAY
     NIGHT FOR MNZ033-034.

     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING
     FOR MNZ020-035-037.

WI...WINTER STORM WARNING FROM 4 AM WEDNESDAY TO 4 AM CDT THURSDAY
     FOR WIZ006.

     WINTER STORM WARNING FROM 10 AM WEDNESDAY TO 10 AM CDT THURSDAY
     FOR WIZ001>004-007>009.

LS...NONE.
&&

$$

UPDATE...BJT
SHORT TERM...GROCHOCINSKI
LONG TERM...STEWART
AVIATION...MILLER






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