Area Forecast Discussion
Issued by NWS Duluth, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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 170919
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
419 AM CDT THU APR 17 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 418 AM CDT THU APR 17 2014

AT 4 AM...SNOW CONTINUED ACROSS PORTIONS OF THE MINNESOTA
ARROWHEAD AND NORTHWESTERN WISCONSIN. TEMPERATURES RANGED FROM
THE LOWER 20S IN THE WESTERN CWA TO THE UPPER 20S AND LOWER 30S
EAST. THE MOST INTENSE SNOWFALL AT THIS TIME WAS OVER THE INTERIOR
ARROWHEAD AND ACROSS NORTHWESTERN WISCONSIN AROUND THE KHYR AREA
AS A DEFORMATION AREA WORKED THROUGH THOSE AREAS.

THE MAJOR SPRING SNOW STORM THAT BROUGHT WELL IN EXCESS OF A FOOT
OF SNOW TO MUCH OF EAST CENTRAL MINNESOTA AND NORTHWESTERN WISCONSIN
WILL GRADUALLY PULL OFF TO THE NORTH AND EAST TODAY. WINDS WILL
GRADUALLY DECREASE AND ANY ACCUMULATING SNOWFALL SHOULD HAVE ENDED
BY NOON. AS EXPECTED...THE GRADIENT WAS PRETTY EXTREME WITH THIS
SNOWFALL EVENT...WITH LITTLE TO NO SNOWFALL FROM THE IRON RANGE
NORTHWESTWARD. IN THE TWIN PORTS...HEAVIER SNOW WAS FOUND IN THE
CITY OF SUPERIOR...WHERE AMOUNTS APPROACHED A FOOT IN SPOTS.

SKIES SHOULD GRADUALLY CLEAR FROM THE WEST TODAY...WITH MOSTLY
CLEAR SKIES ALREADY IN OUR FAR WESTERN ZONES. THE CLEARING WILL
TAKE SOME TIME THOUGH...AS MOISTURE LINGERS DUE TO THE NEGATIVE
TILT TROUGH AND MOISTURE HANGING BACK BEHIND THE DEPARTING LOW
PRESSURE SYSTEM. TEMPERATURES SHOULD REACH WELL INTO THE 30S TODAY
DESPITE THE FRESH SNOW COVER. WITH SUNSHINE AT A HIGH ANGLE THERE
SHOULD BE PLENTY OF MELTING AREA WIDE. LOWS TONIGHT WILL FALL BACK
INTO THE TEENS AND 20S...WITH HIGHS ON FRIDAY REACHING INTO THE
40S FOR MUCH OF THE AREA.

.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 418 AM CDT THU APR 17 2014

FRIDAY NIGHT AND SATURDAY...THE MODELS ARE IN MUCH BETTER AGREEMENT
WITH THIS PERIOD THAN WHAT I OBSERVED IN THE MODELS ON MY PREVIOUS
NIGHT SHIFT. A LOW PRESSURE SYSTEM IS EXPECTED TO EXIT THE NORTHERN
HIGH PLAINS INTO DAKOTAS AND SOUTH SASKATCHEWAN/MANITOBA FRIDAY
NIGHT...AS ITS ASSOCIATED MID/UPPER LEVEL AND SHORTWAVE MOVES EAST
NEAR THE BORDER BETWEEN MONTANA AND CANADA...AND AS ITS MID LEVEL
WARM FRONT LIFTS INTO THE NORTHERN PLAINS AND NORTHLAND. THIS
APPROACHING LOW PRESSURE SYSTEM AND ITS WARM FRONT WILL LIKELY BRING
LIGHT TO MODERATE PCPN TO THE NORTHLAND LATE FRIDAY NIGHT AND
SATURDAY. THE MODELS ON MY LAST SHIFT HAD MAJOR DIFFERENCES IN
TIMING AND PCPN AMOUNTS...BUT THE LATEST 00Z RUNS ARE IN MUCH BETTER
AGREEMENT. I WAS ABLE TO REFINE THE TIMING OF THE PCPN AND INCREASE
PCPN CHANCES BASED ON MY HIGHER CONFIDENCE STEMMING FROM THE GOOD
MODEL AGREEMENT.

THE PCPN SHOULD BEGIN TO MOVE INTO THE WESTERN AND NORTHERN FORECAST
AREA AROUND OR AFTER MIDNIGHT. DETERMINING PCPN TYPE IS TRICKY.
OVERNIGHT LOWS ACROSS MUCH OF THE NORTHERN/CENTRAL/EASTERN FORECAST
AREA SHOULD BE IN THE UPPER 20S TO VERY LOW 30S. HOWEVER...THERE THE
LOWS WILL LIKELY OCCUR IN THE EVENING AS INCREASING CLOUD COVER AND
SE WINDS BRING WARMING TEMPERATURES LATER IN THE NIGHT. WHILE MODEL
SOUNDINGS INDICATE THE PCPN WILL LIKELY BEGIN AS SNOW FOR MUCH OF
THE FORECAST AREA...THERE SHOULD BE TRANSITION TO RAIN AS THE WARMER
AIR BUILDS INTO THE REGION. IN BETWEEN THAT TRANSITION
PERIOD...THERE COULD BE A SHORT PERIOD OF SLEET AND FREEZING RAIN. I
FOCUSED ON THE FREEZING RAIN THREAT TO NOT OVER COMPLICATE THE
FORECAST BY ALSO ADDING SLEET. I ONLY ADDED MINIMAL ACCUMULATION OF
ICE FROM FREEZING RAIN IN WHAT I BELIEVE WILL BE THE MOST LIKELY
AREAS WHERE THERE COULD BE FREEZING RAIN. WE WILL NEED TO LOOK INTO
THIS MORE WHEN THE TIME GETS CLOSER. THE SREF WAS ALSO HELPFUL IN
DETERMINING THE MOST LIKELY AREA WHERE THERE COULD BE FREEZING RAIN.

THE LOW PRESSURE SYSTEM WILL MOVE FROM SOUTHERN SASKATCHEWAN INTO
SOUTHERN/CENTRAL MANITOBA SATURDAY...WHILE ITS COLD FRONT MOVES
THROUGH THE NORTHLAND. THE LIGHT TO MODERATE PCPN SHOULD GRADUALLY
MOVE EAST THROUGH THE NORTHLAND DURING THE DAY. THERE COULD BE SOME
LINGERING SNOW AND FREEZING RAIN IN THE ARROWHEAD UNTIL MID TO LATE
SATURDAY MORNING WHEN THE SURFACE TEMPERATURES WARM TO AT LEAST THE
MID 30S. I ADDED ISOLATED THUNDER ACROSS THE SOUTHERN FORECAST AREA
AS THERE COULD BE SOME ELEVATED CAPE AND EMBEDDED LIGHTING WITHIN
THE HEAVIER RAIN BANDS. THIS WAS ALSO BASED ON THE SREF WAS SHOWING
LOW CHANCES OF CONVECTIVE PCPN ACROSS THE SOUTHERN FORECAST AREA
DURING THE DAY SATURDAY. TEMPERATURES WILL BE ABOUT 10 DEGREES BELOW
NORMAL.

SATURDAY NIGHT...THE PCPN SHOULD CONTINUE TO GRADUALLY SHIFT EAST OF
THE NORTHLAND OVERNIGHT AS THE LOW PRESSURE SYSTEM MOVES FROM
MANITOBA INTO FAR NW ONTARIO. ANY LINGERING RAIN AND THUNDER SHOULD
PRIMARILY BE IN NW WISCONSIN AS THE FRONT WILL STILL BE MOVING
THROUGH THAT AREA DURING THE EVENING AND WILL LIKELY NOT EXIT UNTIL
THE FORECAST AREA UNTIL LATE IN THE NIGHT.

SUNDAY THROUGH TUESDAY...FOR THE MOST PART...THIS PERIOD LOOKS MUCH
WARMER AND DRY AS HIGH PRESSURE MOVES INTO THE REGION. THERE COULD
BE SOME LIGHT RAIN ACROSS THE NORTHERN FORECAST AREA SUNDAY NIGHT
AND MONDAY AS THE GFS AND ECMWF INDICATE A WEAK LOW PRESSURE SYSTEM
AND WEAK COLD FRONT MOVING THROUGH THE REGION. TEMPERATURES WILL
LIKELY BE NEAR OR SLIGHTLY ABOVE NORMAL.

TUESDAY NIGHT AND WEDNESDAY...THIS COULD EB ANOTHER ACTIVE PERIOD
WITH RAIN AND THUNDERSTORMS. THE GFS AND ECMWF ARE IN FAIRLY GOOD
AGREEMENT THAT A LOW PRESSURE SYSTEM WILL BE ORGANIZING IN THE HIGH
PLAINS NEAR THE BORDER BETWEEN MONTANA AND SASKATCHEWAN TUESDAY
NIGHT. THE MODELS INDICATE THAT THE ASSOCIATED MID LEVEL WARM FRONT
WILL GRADUALLY LIFT NORTH AND EAST INTO THE NORTHERN PLAINS AND
UPPER MIDWEST TUESDAY NIGHT AND WEDNESDAY. THIS COULD BRING SHOWERS
AND THUNDERSTORMS TO THE NORTHLAND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1243 AM CDT THU APR 17 2014

BAND OF SNOW DRAPED ACROSS KDLH AND KHYR AS OF 06Z WITH IFR TO
LIFR CONDITIONS AT KDLH AND MVFR AT KHIB...WITH VFR AT KINL AND
KBRD. THIS SNOW TO CONTINUE THROUGH MUCH OF THE OVERNIGHT WITH
CONDITIONS LOWERING AT KHYR BACK TO IFR FOR OVERNIGHT. KHIB TO
ALSO LOWER TO MVFR FOR SEVERAL HOURS OVERNIGHT AND THURSDAY
MORNING. THESE SAME LOW CLOUDS TO SPREAD INTO KINL FOR A FEW HOURS
AFTER 10Z...THEN IMPROVING AGAIN BY 17Z. CONDITIONS SHOULD TO MVFR
CIGS BY 18Z...AND THEN TO VFR BY 00Z THURSDAY EVENING.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  36  21  39  27 /  50  10  10  50
INL  38  17  44  30 /  10  10  10  70
BRD  41  24  44  33 /  10  10  10  50
HYR  39  17  44  28 /  60  10  10  10
ASX  38  19  39  24 /  90  10  10  30

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING UNTIL NOON CDT TODAY FOR MNZ012-021.

     WINTER STORM WARNING UNTIL 6 AM CDT EARLY THIS MORNING FOR
     MNZ020-037.

     WINTER WEATHER ADVISORY UNTIL 6 AM CDT EARLY THIS MORNING FOR
     MNZ019.

WI...WINTER STORM WARNING UNTIL 6 AM CDT EARLY THIS MORNING FOR
     WIZ001-007.

     WINTER STORM WARNING UNTIL 10 AM CDT THIS MORNING FOR WIZ002>004-
     008-009.

LS...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR LSZ121-
     144>148.

     SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR
     LSZ140>143.

&&

$$

SHORT TERM...DAP
LONG TERM...GROCHOCINSKI
AVIATION...LE







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