Area Forecast Discussion
Issued by NWS Duluth, MN

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000
FXUS63 KDLH 201446 AAA
AFDDLH

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
946 AM CDT SUN APR 20 2014

.UPDATE...
ISSUED AT 941 AM CDT SUN APR 20 2014

ONLY MINOR TWEAKS TO EXISTING GRIDS/ZFP. FOG HAS DISSIPATED OVER
SERN PART OF THE CWA AS MIXING LAYER INCREASES FROM SUNSHINE. SOME
CONCERN THAT NEARSHORE MAX TEMPS MAY BE MODULATED BY MARINE
BOUNDARY LAYER. FOR NOW...FCST 2K FT WINDS SUGGEST ENOUGH OFFSHORE
PUSH TO LOWER PROBABILITY OF AN EARLY PUSH INLAND. ONLY CLOUDS OF
NOTE TODAY WILL BE OVER SERN CORNER OF THE REGION WHERE NRN FRINGE
OF CLOUDS FROM SRN FRONTAL BDRY ARE ADVECTING NORTHEASTWARD.

UPDATE ISSUED AT 636 AM CDT SUN APR 20 2014

UPDATED FOR AVIATION SECTION BELOW.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM CDT SUN APR 20 2014

MAIN CONCERNS IN THE SHORT TERM REMAIN CENTERED AROUND THE ON-GOING
RAIN SHOWERS OVER SRN SAWYER AND PRICE COUNTIES THIS MORNING...THE
POTENTIAL FOR PATCHY FOG THIS MORNING AS WELL...WARM TEMPERATURES
THIS AFTERNOON...AND THE NEXT ROUND OF LIGHT RAIN SHOWERS EXPECTED
TONIGHT.

A TRAILING WEAK COLD FRONT ORIENTED NE-SW FROM ERN LAKE SUPERIOR
BACK TOWARD SRN MN CONTINUES TO INTERACT WITH A MOIST AND WEAKLY
UNSTABLE AIR MASS TO THE SOUTH AND PRODUCE RAIN SHOWERS OVER THE
EXTREME SERN PORTIONS OF THE FORECAST AREA. THIS BAND OF SHOWERS
WILL CONTINUE TO SLOWLY TRACK TO THE EAST THIS MORNING AS HIGH
PRESSURE AT THE SFC BUILDS IN ACROSS NRN MN. THE FLOW ALOFT WILL
CONTINUE TO REMAIN FAIRLY ZONAL...HOWEVER THE PRESENCE OF VERY DRY
AIR FROM THE SFC RIDGE WILL ALLOW SKIES TO REMAIN MOSTLY SUNNY TODAY
AND ALSO CONTRIBUTE TO THE WARM TEMPERATURES EXPECTED THIS
AFTERNOON.

IN ADDITION...THROUGH THE REST OF THIS MORNING THERE WILL BE A
SLIGHT CHANCE OF PATCHY FOG ACROSS THE NORTHLAND...WITH THE MOST
FAVORABLE AREA EXPECTED AROUND THE PERIPHERY OF LAKE SUPERIOR
WHERE THE NEAR-SFC AIR MASS IS MORE MOIST AND CLOSER TO
SATURATION. VSBYS HAVE BEEN AROUND 3-5 MILES SO FAR THIS
MORNING...AND COULD POSSIBLY DIP TO AROUND 1 MI IN SOME LOCATIONS.
NO WIDESPREAD DENSE FOG IS EXPECTED.

A RELATIVELY WARM AIR MASS WILL BUILD IN OVER THE UPPER MIDWEST
TODAY AND COMBINE WITH WEAK SUBSIDENCE FROM THE SFC HIGH AND STRONG
SOLAR HEATING FROM THE SUNNY SKIES TO PRODUCE HIGH TEMPERATURES IN
THE 50S THROUGH THE ARROWHEAD AND WELL INTO THE 60S FOR MUCH OF THE
NORTHLAND.

FOR TONIGHT...CONDITIONS WILL START OUT WARM AND DRY BUT CHANGE
THROUGH THE NIGHT AS TWO WEAK SYSTEMS APPROACH THE NORTHLAND. ONE
LOW PRESSURE SYSTEM FROM THE SOUTH WILL MOVE FROM THE CENTRAL PLAINS
NEWD INTO SRN MN/SWRN WI AND CONTINUE TO INTERACT WITH THE MOIST AIR
MASS TO THE SOUTH...PRODUCING LIGHT RAIN SHOWERS OVER THE SERN
PORTIONS OF THE NORTHLAND ONCE AGAIN. THE OTHER SYSTEM WILL RIDE IN
FROM THE NW IN THE FORM OF A COLD UPPER LOW. THIS SYSTEM WILL BE
SLIGHTLY MORE DYNAMIC...BUT NOT HAVE THE NECESSARY MOISTURE
AVAILABLE TO PRODUCE ANY SIGNIFICANT PRECIP. THE END RESULT IS A
CHANCE OF RAIN SHOWERS ACROSS THE NORTH AND SOUTH...WITH MOSTLY DRY
CONDITIONS IN BETWEEN. TEMPS WILL FALL AGAIN TONIGHT INTO THE 30S
AND LOWER 40S.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 357 AM CDT SUN APR 20 2014

MONDAY THE COLD FRONT MOVING THROUGH THE AREA IS EXPECTED TO
CONTINUE TO GENERATE SHOWERS BOTH NORTHEAST AND SOUTHEAST.
HOWEVER...THE SURFACE RIDGE WILL BUILD INTO THE AREA FROM THE
NORTHWEST...AND CONDITIONS SHOULD DRY OUT BY LATE AFTERNOON.  HIGH
TEMPERATURES WILL BE WARM AGAIN WITH HIGHS ACROSS THE SOUTH IN THE
60S AGAIN...BUT THE COLDER AIR BUILDING IN FROM THE NORTHWEST SHOULD
KEEP HIGHS THERE BACK IN THE MID AND UPPER 50S.  THE SURFACE RIDGE
BUILDING ACROSS THE AREA ON TUESDAY WILL KEEP THE WEATHER QUIET AND
CLEAR...WITH HIGHS TUESDAY IN THE 50S.

WEDNESDAY THROUGH FRIDAY IS OUR NEXT MAJOR WEATHER MAKER...AS A SLOW
MOVING UPPER LEVEL LOW MOVES ACROSS THE UPPER MIDWEST.  THIS SYSTEM
SHOULD START OUT WITH RAIN AS THE WARM AIR ADVECTION PUSHES ACROSS
THE AREA.  ON THE SOUTHERN FLANKS OF THIS WARM AIR ADVECTION WING WE
SHOULD ALSO GET SOME THUNDER...MAINLY ON WEDNESDAY NIGHT AND
THURSDAY WITH SOME FAIRLY STEEP MID LEVEL LAPSE RATES AND EVEN SOME
WEAK LOW LEVEL CAPE.  MODELS ARE IN GOOD ENOUGH AGREEMENT ON
WEDNESDAY AND THURSDAY TO HAVE FAIRLY GOOD CONFIDENCE ON
THIS...THOUGH THE ECMWF IS COOLER AT THIS POINT THAN THE GFS.
PRECIPITATION SHOULD REMAIN ALL RAIN SHOWERS THROUGH THURSDAY AS
WELL...THOUGH TIMING IS GOING TO BE QUITE TRICKY.  THURSDAY NIGHT
AND FRIDAY THE COLD AIR IS EXPECTED TO SURGE INTO THE AREA FROM THE
NORTHWEST...WITH THE ECMWF FASTER THAN THE DEEPER AND SLOWER GFS.
FOR NOW HAVE KEPT THINGS FAIRLY GENERIC WITH A RAIN/SNOW MIX
OVERNIGHT AND FRIDAY...WITH ALL SNOW FRIDAY NIGHT BEFORE THE EVENT
ENDS.  CONFIDENCE IS NOT VERY HIGH ON PRECIP TYPE OR TEMPERATURES BY
THURSDAY AND FRIDAY ON THIS SYSTEM.  FOR NOW TEMPERATURES THROUGH
THE PERIOD TO BE COLDER THAN NORMAL THROUGHOUT...BUT EXPECT TO BE
MAKING CHANGES IN UPCOMING FORECASTS.

SATURDAY CHILLY BUT QUIET WITH HIGHS IN THE 40S.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 636 AM CDT SUN APR 20 2014

LINGERING LOW LEVEL MOISTURE WILL KEEP A POTENTIAL FOR FOG AT
KDLH...KHIB...AND KHYR FOR A FEW MORE HOURS. OTHERWISE...EXPECT
CLEARING SKIES TODAY WITH LIGHT AND VARIABLE WINDS. FEW TO
SCATTERED CUMULUS ARE POSSIBLE OVER NORTHWEST WISCONSIN AT OR
ABOVE 3KFT...BUT SHOULD NOT GO BROKEN. SOME MID AND HIGH LEVEL
CLOUDS WILL MOVE ACROSS THE TERMINALS AFTER 06Z TONIGHT...BUT
CONDITIONS EXPECTED TO REMAIN VFR.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  59  38  60  33 /   0  10  10   0
INL  60  40  52  31 /   0  30  20  10
BRD  66  44  63  35 /   0  10  10   0
HYR  64  38  65  33 /  10  20  30   0
ASX  58  33  62  34 /  10  10  30   0

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&

$$

UPDATE...CANNON
SHORT TERM...BJT
LONG TERM...LE
AVIATION...LE






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