FXUS63 KDLH 010945
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
345 AM CST TUE DEC 1 2009
.DISCUSSION...
THRU WED...
MODELS IN REASONABLY GOOD AGMT ON POSITION AND EVOLUTION OF SFC LOW
OVR NWRN ND ATTM. LOW WILL DIP DOWN ACRS CENT MN AS IT PROGRESSES
EWD...MOVG E OF LK SUP BY MIDDAY WED. SPEED OF SYSTEM AND LACK OF A
GOOD MSTR SOURCE WILL LIMIT ACCUMS...BUT STRENGTH OF ASSOC
DYNAMICS OUGHT TO BE SUFFICIENT FOR 3-5 INCHES N OF THE IRON
RANGE...WITH LOCAL AMTS PSBLY TO ARND 6 INCHES CLOSE TO THE CN
BORDER. AMTS WILL THEN TAPER OFF TO LESS THAN AN INCH IN SRN PARTS
OF THE CWA. WILL ISSUE WSW FOR N OF THE RANGE RUNNING FROM NOON TDA
TO NOON WED. FUTURE SHIFTS MAY BE ABLE TO CANX EARLY...BUT WITH UPR
LVL CYC FLOW ALOFT THRU THE PD...IT WILL PRBLY NOT STOP SNOWING
COMPLETELY. THE MAJOR ACCUMULATING SNOW HWVR WILL PRBLY FALL FROM
MID AFTN TDA THRU VERY EARLY WED MRNG. WINDS ON BACK SIDE OF THE LOW
WILL ALSO BE A FACTOR ON WED...CAUSING SOME BLOWING AND DRIFTING.
EXPECT LOWER HIGH TEMPS ON WED AS CAA BEGINS TO SET UP...CONTINUING
THRU THE REST OF THE WEEK.
WEDNESDAY NIGHT THRU SUNDAY...
MDT/STRONG MDL CONSENSUS THAT A LARGE AMPLITUDE MID LVL TROF WILL
DOMINATE THE REGIONAL WEATHER PATTERN THIS PERIOD. BY BEGINNING OF
PERIOD...SHOULD HAVE ESTABLISHED A SNOWPACK UPSTREAM OF CWA AND INTO
AT LEAST NRN THIRD OF AREA. 85H TEMPS WILL DROP BELOW NORMAL VALUES
FOR THE PERIOD SO SHOULD ACTUALLY SEE MIN/MAX TEMPS DROP BELOW NORMS
TO SOME DEGREE. CLOUDS/PASSING SNSH WILL MODIFY TEMPS AT NIGHT. MAIN
QPF THIS PERIOD WILL BE ASSOCIATED WITH LES ACROSS SNOWBELT. SOME
CONTRIBUTING FACTORS OF NOTE: LAKE INDUCED CAPE SHOULD REACH BETWEEN
500/750 J/KG INDICATING MODERATE LVLS OF INSTABILITY...LAKE INDUCED
EQL MAINTAINS 10/15K FT THROUGHOUT PERIOD WITH NO INVERSION ISSUES
TO RESTRICT GROWTH OF LAKE CLOUDS...AND AT LEAST A 24/36 HR PERIOD
OF OMEGA WITHIN THE FAVORED DENDRITIC GROWTH ZONE. AS USUAL...ANY
SIGNIFICANT DEVIATIONS IN LOW LVL TRAJECTORY OFF LAKE WILL AFFECT
THE INTENSITY/LOCATION OF BEST PLUMES. MDL SIGNALS HAVE BEEN
CONSISTENT THAT SIGNIFICANT ACCUMULATION IS BECOMING MORE LIKELY
GIVEN SYNOPTIC PATTERN...TIME OF YEAR WITH OPEN LAKE....AND
ANOMALOUS 85H TEMPS. OTHERWISE SHORTWAVES EMBEDDED WITHIN DEEP
CYCLONIC CIRCULATION SHOULD ACT UPON RELATIVELY MOIST COLUMN TO
GENERATE PERIODIC SNSH/FLURRIES IN MOST AREAS.
&&
.AVIATION...06Z TAF ISSUANCE...
CLOUDS WILL RAPIDLY INCREASE ACROSS THE NRN/CTRL CWA WITH SNOW
DEVELOPING AT INL/HIB TERMINALS BY MID MORNING. MAINLY MVFR EXPECTED
ALTHOUGH OCCASIONAL MDT SNOW MAY DROP VIS TO IFR CATEGORY. DLH WILL
EXPERIENCE MAINLY MVFR CLGS WITH SOME LT SNOW.MAINLY VFR AT BRD/HYR
THROUGH PERIOD.
&&
.POINT TEMPS/POPS...
DLH 35 23 29 15 / 20 40 30 10
INL 31 18 25 10 / 90 70 40 20
BRD 42 24 29 14 / 10 20 30 10
HYR 41 26 30 18 / 10 20 20 30
ASX 38 28 30 20 / 20 40 40 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM NOON TODAY TO NOON CST WEDNESDAY
FOR MNZ010>012-018-019-021.
WI...NONE.
LS...NONE.
&&
$$
04/CANNON/BERDES
