Area Forecast Discussion
Issued by NWS Duluth, MN

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000
FXUS63 KDLH 241757
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
ISSUED BY NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1257 PM CDT THU JUL 24 2014

.SYNOPSIS...
ISSUED AT 310 AM CDT THU JUL 24 2014

SFC HIGH IS POSITIONED OVER THE CWA EARLY THIS MORNING WITH MOSTLY
CLEAR SKIES AND CALM CONDITIONS. TEMPS HAVE LOWERED TO THE LOW TO
MID 40S FROM THE ARROWHEAD INTO NWRN WISCONSIN. PATCHY FOG IS
DEVELOPING ACROSS THE REGION AND SHOULD SEE SOME INCREASE IN AREAL
COVERAGE UNTIL 11Z.

&&

.SHORT TERM...(TODAY AND TOMORROW)
ISSUED AT 310 AM CDT THU JUL 24 2014

TODAY...SFC HIGH SHIFTS SOUTHEAST OF THE REGION ALLOWING SOME
INCREASE IN THE WARM ADVECTION PATTERN. 85H MSTR TRANSPORT MAGNITUDE
HAS TRENDED DOWNWARD FROM YESTERDAYS MODEL OUTPUT. MULTI MODEL QPF IS
MUCH SLOWER IN ADVANCING MEASURABLE INTO THE REGION. HAVE OPTED TO
REMOVE POPS FROM TODAYS FCST WITH COLLABORATION FROM SURROUNDING
OFFICES. MAX TEMPS A DEGREE OR TWO HIGHER BASED ON FCST 925 TEMPS. SCT
CLOUDS LIKELY AROUND 5KFT BASED ON LATEST BUFKIT MOISTURE PROFILES.

TONIGHT...SFC LOW WILL MAKE ITS WAY ACROSS SODAK WITH DEVELOPMENT OF
A LLJ EXPECTED TO OCCUR FROM ERN NEB TO SWRN MN BY MIDNIGHT AND THEN
STRETCH FROM KANSAS TO NRN IOWA BY 12Z. IT APPEARS A MCS/MCC WILL
DEVELOP ACROSS THE PLAINS AND TRACK INTO SRN MN/NRN IA BY EARLY
MORNING ON THE NRN FRINGE OF A MID LVL CAP. AN INVERTED SFC TROUGH
FROM ERN SODAK TO SRN MANITOBA MAY PROMOTE INCREASED BDRY LYR
CONVERGENCE HOWEVER MID LVL WARMING MAY PROVIDE ENOUGH INHIBITION TO
RESTRICT CONVECTIVE POTENTIAL. HAVE LOWERED POPS AND SLOWED ARRIVAL
INTO ARROWHEAD. IT IS POSSIBLE THAT THE LEVEL OF MID LVL WARMING MAY
NEGATE POPS ENTIRELY ACROSS A LARGER PART OF THE CWA AND UPDATES MAY
BE REQUIRED.

TOMORROW...MID LVL RIDGE WILL FLATTEN AS THE SFC FRONTAL BDRY SLOWLY
MOVES TOWARDS THE NORTHLAND. OVERALL THERMODYNAMICS SUGGEST THAT
INCREASING BDRY LYR INSTABILITY WILL DEVELOP AS THE MID/UPPER CLOUD
LAYER ADVECTS EAST BY MIDDAY. FRONTAL CONVERGENCE DOESNT MATERIALIZE
UNTIL LATE AFTN OVER WRN EDGE OF CWA. WITH LITTLE BDRY LYR
CONVERGENCE TO FOCUS INITIATION AND A RELATIVELY WARM MID LAYER
STILL IN EXISTENCE...CONVECTION MAY HAVE SOME DIFFICULTY ORGANIZING.
AT THIS TIME HIGHEST PROB OF DEVELOPMENT MAY BE ACROSS NWRN   CWA IN
AN AREA OF GREATEST SFC BASED INSTABILITY/LOWER CIN AND 35/45KT DEEP
LAYER SHEAR. MAX TEMPS WILL BE A LITTLE TRICKY AS WARM ADVECTION
LIFTS LOW LVL THICKNESSES HOWEVER CLOUD COVER WILL MITIGATE SOME OF
THAT WARMING IN ERN CWA.

.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 310 AM CDT THU JUL 24 2014

THE UPPER LEVEL FLOW WILL TRANSITION FROM ZONAL WITH AN UPPER LOW
OVER SOUTHEAST SK EARLY IN THE PERIOD...TO NORTHERLY FLOW BY EARLY
NEXT WEEK.

THE UPPER LOW OVER SK WILL MOVE THROUGH THE NORTHLAND THIS WEEKEND
BRINGING A CHANCE FOR SHOWERS AND THUNDERSTORMS THROUGH SUNDAY.
PRECIP COVERAGE WILL BE AT A MINIMUM FRIDAY NIGHT AS FORCING
WEAKENS. THE UPPER LOW WILL THEN CONTINUE SOUTHEAST SATURDAY INTO
SUNDAY BRINGING A BETTER CHANCE FOR RAIN INTO THE REGION. THE ECMWF
IS SLOWER WITH THE UPPER LOW...AND IS LIKELY MORE ACCURATE AND HAS
SUPPORT FROM THE NAM/GEM. SATURDAY NIGHT WILL FEATURE THE HIGHEST
POPS AS THE UPPER WAVE MOVES THROUGH THE NORTHLAND. HIGHS SATURDAY
WILL REACH THE UPPER SEVENTIES TO MID EIGHTIES.

WE INCREASED TEMPS A BIT SUNDAY DUE TO THE EXPECTED SLOWER ARRIVAL
OF THE UPPER WAVE AND COOLER TEMPS. MONDAY SHOULD BE DRY WITH THE
NORTHLAND SANDWICHED BETWEEN THE SURFACE HIGH OVER THE NORTHERN
PLAINS AND LOW PRESSURE WELL OFF TO THE EAST. HIGHS MONDAY WILL
RANGE FROM 70-75.

THE UPPER LOW WILL GET ABSORBED INTO THE LARGER LOW CENTERED NEAR
JAMES BAY MONDAY. THE UPPER LOW WILL THEN RETROGRADE SOME. WE HAVE
SOME LOW POPS TUESDAY/WEDNESDAY AS A WEAK WAVE OR TWO WILL MOVE
THROUGH IN THE NORTHERLY FLOW ALOFT. HIGHS WILL BE MAINLY IN THE MID
TO UPPER SEVENTIES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT CDT THU JUL 24 2014

CONFIDENCE IS INCREASING THAT AN AREA OF SCATTERED THUNDERSTORMS
WILL DROP SOUTH ACROSS NORTHERN AND CENTRAL MINNESOTA
TONIGHT...BUT THE DETAILS STILL NEED TO BE WORKED OUT. THE STORMS
THIS AFTERNOON WILL MISS THE TAF SITES TO THE SOUTHWEST...KBRD IS
REALLY THE ONLY SITE THAT MIGHT GET GRAZED BY A FEW SHOWERS. THE
SECOND BATCH TONIGHT SHOULD FORM A LITTLE FARTHER NORTH AND
EAST...WHICH WOULD PUT IT ON A BETTER TRACK TOWARD THE TAF SITES
IN NORTHERN MN AND EVENTUALLY INTO NORTHWEST WI. WE AREN`T TOTALLY
CLEAR ON THE SPECIFIC TIMING /OR LOCATION/...BUT THE BEST WINDOW
LOOKS LIKE 06-12Z. WE KEPT THE THUNDER OUT OF KINL WITH THE 18Z
ISSUANCE...BUT IT`S CLOSE AND WE WILL LOOK TO UPDATE AT 21Z. WE
MIGHT NEED TO INCLUDE THUNDER IN THE TAF WHEN WE UPDATE. A LOT OF
THE FORECASTING MODELS WE LOOK AT ARE CALLING FOR MVFR/IFR
STRATUS LATE TONIGHT...BUT THIS IS HIGHLY DEPENDENT ON HOW MUCH
RAIN FALLS. THIS REALLY ISN`T A CLIMATOLOGICALLY FAVORABLE TIME OF
YEAR TO FORECAST WIDESPREAD LOW STRATUS.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  76  59  77  60 /  10  20  30  40
INL  77  56  78  57 /  10  20  40  50
BRD  79  64  80  61 /  10  30  30  20
HYR  77  59  77  59 /  10  30  30  30
ASX  73  58  77  58 /  10  20  30  40

&&

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

$$

SYNOPSIS...CANNON
SHORT TERM...MELDE
LONG TERM...MELDE
AVIATION...MILLER







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