Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 210935
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
335 AM CST FRI NOV 21 2014

.SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON)
ISSUED AT 333 AM CST FRI NOV 21 2014

MAIN CONCERNS IN THE SHORT TERM REMAIN FOCUSED AROUND THE COLD
TEMPERATURES THIS MORNING...RISING QUICKLY THROUGH THE DAY INTO
THE LOWER-MID 20S AND REMAINING MILD THROUGH TONIGHT WITH ANOTHER
JUMP INTO THE 30S ON SATURDAY. WILL ALSO HIGHLIGHT THE POTENTIAL
FOR DRIZZLE AND FREEZING DRIZZLE LATE TONIGHT AND INTO SAT
MORNING.

UPPER LEVEL RIDGE BUILDING EWD ACROSS THE UPPER MIDWEST THIS
MORNING ALONG WITH A FAIRLY ROBUST AREA OF WAA IN THE MID LEVELS.
AT THE SFC A LARGE AREA OF HIGH PRESSURE CONTINUES TO SHIFT TO THE
EAST OVER THE SRN GREAT LAKES AS A TROUGH SLIDES INTO ERN MT AND
NRN CO. THE UPPER RIDGE AHEAD OF THE TROUGH AXIS IS EXPECTED TO
DE- AMPLIFY AS IT TRACKS EWD TODAY...WITH THE GENERAL FLOW
BECOMING QUASI- ZONAL TONIGHT AND SATURDAY...AND THE WEAKENING TROUGH
ROTATING EWD OVER THE REGION.

THE STRONG WAA ALOFT WILL ACT TO CREATE A SHARP INVERSION OVER
MUCH OF THE AREA LATER TODAY THROUGH SAT MORNING. SHOULD SEE CLOUD
COVER CONTINUE TO STREAM IN FROM THE W/NW TODAY DUE TO WEAK MID
LEVEL F-GEN SETTING UP ALONG THE DAKOTAS/NRN MN REGION AND THE
APPROACHING UPPER TROUGH. THE BROAD LARGE SCALE FORCING FROM THIS
UPPER TROUGH WILL ACT TO PRODUCE LIGHT PRECIP ACROSS PORTIONS OF
THE NORTHLAND TONIGHT AND SAT MORNING...MAINLY IN THE FORM OF DZ
OR FZDZ. SHOULD BE GENERALLY FZDZ FROM LATE TONIGHT THROUGH MOST
OF SAT MORNING...AND A CHANGEOVER TO ALL DZ IN THE LATE
MORNING/EARLY AFTERNOON. HAVE ALSO INCLUDED A MENTION OF A SLIGHT
CHANCE OF SLEET DURING THE PERIOD WHEN THE PRECIP CHANGES OVER TO
LIQUID. WEAK RIDGING REGAINS A HOLD ON THE AREA BY THE LATE
AFTERNOON ON SATURDAY WITH QUIET CONDITIONS EXPECTED GOING INTO
THE EVENING.

TEMPERATURES THIS MORNING ARE REACTING TO THE WAA/MIXING AND
APPROACHING CLOUD COVER FROM THE W/NW WITH A NOTICEABLE INCREASE IN
TEMPS BEING OBSERVED OVER NE MN. WILL SEE THE SAME TREND OCCUR
FURTHER TO THE EAST INTO NW WI THROUGH THE MORNING. TEMPERATURES
WILL WARM INTO THE LOWER TO MID 20S TODAY...BUT NOT GET MUCH
WARMER THAN THAT DUE TO THE LIMITED AMT OF SUN UNDER THE ROBUST
CLOUD COVER.

THE CLOUD COVER WILL ALSO ACT TO KEEP TEMPERATURES ELEVATED
TONIGHT. LOWS FRI NIGHT/SAT MORNING WILL ONLY FALL INTO THE LOWER
20S...BEFORE RISING ITO THE 30S OVER MUCH OF THE NORTHLAND
SATURDAY.

.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 333 AM CST FRI NOV 21 2014

IT APPEARS THERE WILL BE A BREAK IN THE ACTION SATURDAY EVENING
WITH A SFC RIDGE OVER THE FA. GOOD SHOT OF WAA WITH H85 TEMPS
WARMING TO NEAR 0C ALONG THE INTERNATIONAL BORDER TO 5C ACROSS THE
SOUTH. EXPECT NO PCPN. AFTER 06Z...PCPN BEGINS TO DEVELOP/SPREAD
INTO THE FA AS A SFC LOW DEEPENS NEAR THE NW ND/CANADA BORDER
AREA. THE PCPN IS ON THE NOSE OF A LLJ LIFTING INTO NW WI WITH THE
WAA. MODELS OFFER VERY DIFFERENT SOLUTIONS AT THIS POINT WITH
REGARD TO QPF AND PTYPE. HAVE A MIX OF -RA/-FZRA AS SOUNDINGS FROM
THE DIFFERENT MODELS SUGGEST. THERE WILL BE NO ICE ACCUMULATION
WITH THESE DIFFERENCES. ON SUNDAY MORNING...THE MODELS CONTINUE TO
DIVERGE WITH THE MASS FIELDS. HOWEVER...THEY AGREE THAT A DRY SLOT
IS WORKING INTO WESTERN MN AS A FRONTAL BOUNDARY REACHES THE MN/WI
BORDER BY 18Z. THE BULK OF THE PCPN WILL FALL IN THE VCNTY OF THE
FRONT. THERE WILL BE A MIX OF -FZRA/-SN OVER THE WESTERN HALF OF
THE FA WITH -RA OVER THE E THANKS TO THE WARM AIR AHEAD OF THE
FRONT AND CAA BEGINNING BEHIND THE FRONT. BY MID MORNING...THE
BOUNDARY LAYER WILL HAVE WARMED ENOUGH FOR THE PCPN TO BE ALL
LIQUID. WILL LEAN TOWARD THE ECMWF. THE DRY SLOT MOVES OVER MUCH
OF THE FA SUNDAY NIGHT. HAVE LOWERED THE POPS CONSIDERABLY TO
ACCOUNT FOR THIS FACTOR. -RA WILL OCCUR OVER THE EASTERN THIRD OF
THE AREA WHERE THE WARMEST AIR IS LOCATED. FURTHER WWD A MIX OF
-FZRA/-SN IS EXPECTED AS THE COLUMN COOLS. LATE SUNDAY NIGHT...THE
SFC LOW IS LIFTING INTO NORTHERN LOWER MI WITH THE CLOSED UPPER
LOW MOVING INTO MN. CAA IS WELL UNDERWAY AND -SN WILL BEGIN TO
AFFECT THE WESTERN THIRD OFF THE FA WITH A -FZRA/-SN MIX ELSEWHERE
AS THE REMNANTS OF THE DRY SLOT REACH NW WI. VERY LITTLE ICE
ACCUMULATION IS EXPECTED THROUGHOUT THIS EVENT. THE PCPN FINALLY
BECOMES ALL SNOW ON MONDAY AS THE SFC LOW LIFTS INTO NORTHERN
ONTARIO AND CAA COVERS THE AREA. HAVE A BLSN MENTION AS WELL WITH
TIGHT PRESSURE GRADIENT IN THE VCNTY. THE SNOW DIMINISHES MONDAY
NIGHT AS HIGH PRESSURE ARRIVES AND LINGERS THROUGH TUESDAY. NEXT
ROUND OF LIGHT SNOW ARRIVES TUESDAY NIGHT INTO WEDNESDAY AS A
CLIPPER AFFECTS THE AREA.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1136 PM CST THU NOV 20 2014

AN AXIS OF HIGH PRESSURE WILL SLIDE EAST OVER THE REGION
TONIGHT...ALLOWING VFR CONDITIONS TO PREVAIL THROUGH MORNING.
A TRANSITION TO GUSTY SOUTH WINDS AND STRONG WARM AIR ADVECTION
WILL BE FOUND TODAY...RESULTING IN INCREASING CLOUDS AND MOISTURE
THROUGH THE TAF PERIOD. LATEST NAM BUFR SOUNDINGS SUGGEST LOW
CLOUDS MOVE INTO NORTHEAST MN THIS MORNING...SPREADING OVER
LOCATIONS IN WIS AFTER 18Z. HAVE INTRODUCED LLWS AT ALL TERMINAL
AFTER 00Z AS WINDS ALOFT INCREASE TO 40-50 KT. DUE TO THE SURGE OF
MOISTURE AND SUB-FREEZING SFC TEMPS...THERE IS ALSO A SMALL
THREAT FOR VERY LIGHT FREEZING DRIZZLE...MAINLY LATE
TODAY/TONIGHT. HOWEVER...CONFIDENCE IS LOW SO HAVE LEFT ANY
MENTION OF FZDZ OUT OF TERMINALS AT THIS TIME.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  24  23  35  28 /   0  10  10  10
INL  26  23  35  24 /   0  10  20  10
BRD  26  25  35  27 /   0  10  10  10
HYR  23  22  36  30 /   0  10  10  20
ASX  25  24  38  28 /   0  10  10  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM CST
     SATURDAY FOR LSZ143>146.

     SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 10 AM CST
     SATURDAY FOR LSZ121-140>142-147-148.

&&

$$

SHORT TERM...BJT
LONG TERM...GSF
AVIATION...GRANING






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