Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 201742 AAA
AFDDLH

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
1142 AM CST THU NOV 20 2014

.SHORT TERM...(TODAY THROUGH FRIDAY AFTERNOON)
ISSUED AT 339 AM CST THU NOV 20 2014

MAIN CONCERNS IN THE SHORT TERM REMAIN FOCUSED AROUND THE
LINGERING SNOW SHOWERS ACROSS MAINLY THE ERN HALF OF THE FORECAST
AREA THIS MORNING AND THE CONTINUED THREAT FOR ACCUMULATING LAKE
EFFECT SNOW IN NERN IRON COUNTY THROUGH THE DAY. COLD TEMPERATURES
TODAY AND TONIGHT...WITH A SLIGHT WARM UP ON FRIDAY WILL ALSO BE
HIGHLIGHTED IN THE NEAR TERM.

DEEP UPPER TROUGH OVER ERN CANADA CONTINUES TO ROTATE EWD THIS
MORNING WITH STRONG/COLD CYCLONIC FLOW FROM MANITOBA/WRN ONTARIO
THROUGH THE UPPER MIDWEST AND WRN GREAT LAKES. AREAS OF WEAK PVA
IN THE MID LEVELS COMBINED WITH COLD ARCTIC AIR ALOFT HAVE ALLOWED
THE MDT SNOW SHOWERS TO PERSIST THROUGH THE NIGHT.
HOWEVER...STARTING TO SEE THE DRY AIR TO WEST BEGIN TO SLOWLY MOVE
EWD AND ALLOW THE SNOW SHOWERS TO END AND CLOUDS TO MIX OUT. WILL
SEE THIS TREND CONTINUE THROUGH THE MORNING HOURS AS THE UPPER LOW
SHIFTS EWD. SNOW AMTS WILL BE LIGHT FROM THE ARROWHEAD THROUGH THE
TWIN PORTS AND INTO NW WI...WITH THE EXCEPTION OF THE SOUTH SHORE
DUE TO LAKE ENHANCEMENT.

A LOBE OF VERY COLD AIR WILL DROP IN ACROSS WRN LAKE SUPERIOR
THIS MORNING AND THROUGH MOST OF THE DAY TODAY. 850MB TEMPS WILL
FALL INTO THE -20 DEG C RANGE...AND BE CAPABLE OF MODIFYING
THERMAL PROFILES AND MOIST PLUMES OVER THE LAKE TO PRODUCE LOCALLY
HEAVY SNOW SHOWERS ACROSS PARTS OF THE SOUTH SHORE...MAINLY NRN
IRON COUNTY. THE WLY COMPONENT TO THE WINDS WILL KEEP THE HIGHER
SNOW AMTS FURTHER TO THE EAST INTO THE U.P. HOWEVER...THE TIP OF
THE BAYFIELD PENINSULA AND ESPECIALLY NERN IRON COUNTY COULD SEE
SIGNIFICANT ADDITIONAL ACCUMULATION TODAY. WITH THE POTENTIAL FOR
ANOTHER 2 TO 5 INCHES TODAY...WILL KEEP THE LAKE EFFECT SNOW
ADVISORY GOING FOR NRN IRON CNTY.

HIGH PRESSURE AT THE SURFACE WILL BUILD IN FROM THE WEST THIS
AFTERNOON AND TONIGHT. THE COLD BUBBLE OF AIR DROPPING IN TODAY
WILL KEEP TEMPERATURES IN THE UPPER SINGLE DIGITS AND LOWER
TEENS...AND THE HIGH PRESSURE BUILDING IN TONIGHT WILL ALLOW SKIES
TO CLEAR OUT AND TEMPERATURES TO DROP. LOWS OVERNIGHT AND FRI
MORNING WILL FALL INTO THE SINGLE DIGITS BELOW ZERO...WITH
SLIGHTLY WARMER CONDITIONS NEAR THE LAKE. AS THE SFC RIDGE BUILDS
TO THE EAST ON FRIDAY AN RETURN FLOW WILL DEVELOP ON THE BACK SIDE
OF THE RIDGE AND ALLOW SWLY WINDS TO DRAW UP A WARMER AIR MASS
FROM THE SOUTH. THIS WAA WILL BRING TEMPERATURES UP INTO THE UPPER
TEENS AND LOWER TO MID 20S ON FRIDAY. QUIET WEATHER CONDITIONS
WILL CONTINUE THROUGH THE DAY FRIDAY.

.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 339 AM CST THU NOV 20 2014

A SW FLOW SFC AND ALOFT FRIDAY NIGHT WITH NEUTRAL TO WEAK WAA AND
A WEAK MID LEVEL TROF REACHES THE ND/MN BORDER BY 12Z SATURDAY.
MODELS ARE HAVING A TOUGH TIME DECIDING ON WHETHER THERE WILL BE
ANY PCPN TO AFFECT THE FA. HAVE NO PCPN IN THE EVENING AS DRY
ATMOSPHERE NEEDS TO MOISTEN UP. AFTER 06Z...HAVE SMALL POPS OVER
THE SE CORNER OF THE WI FA WHERE FORECAST SOUNDINGS ARE INDICATING
SOME LIGHT FREEZING RAIN OR SLEET MAY FORM AND SOME OMEGA MOVES
THROUGH. THERE IS A POSSIBILITY FOR SOME FOG...BUT HAVE LEFT OUT
FOR NOW AS THERE SHOULD BE ENOUGH WIND TO KEEP IT FROM FORMING.
MAINTAINED THE SMALL POPS OVER THE SAME GENERAL AREA SATURDAY
MORNING WITH THE SLEET/-FZRA POSSIBLE. BY SATURDAY
AFTERNOON...HAVE NO POP MENTION AS WEAK UPPER LEVEL/SFC RIDGING
COVERS THE FA. MODELS BEGIN TO DIVERGE SATURDAY NIGHT...BUT COME
INTO BETTER AGREEMENT BY SUNDAY NIGHT. LOW PRESSURE ORGANIZES IN
THE CENTRAL PLAINS WHILE AN UPPER LOW DIGS INTO THE NORTHERN
PLAINS. SOUNDINGS INDICATE ANY PCPN THAT DOES FALL OVER MUCH OF NE
MN WILL BE -FZRA POSSIBLY MIXED WITH SNOW. FROM THE BRAINERD LAKES
AREA E THROUGH MUCH OF NW WI A MIX OF RAIN AND SNOW IS ON TAP FOR
SUNDAY MORNING. BY SUNDAY AFTERNOON...THE PCPN SHOULD BE PRIMARILY
RAIN OVER THE SOUTHERN THIRD OF THE FA WITH A RAIN/SNOW MIX
ELSEWHERE. THE SFC LOW DEEPENS AS IT LIFTS THROUGH EASTERN WI.
MEANWHILE...THE UPPER LOW CLOSES OFF. PCPN TYPE ISSUES CONTINUE ON
SUNDAY NIGHT WITH SOME -FZRA/-SN POSSIBLE WITH THE PCPN CHANGING
TO ALL SNOW OVER THE WESTERN EDGE OF THE FA. ON MONDAY...THE
MODELS POINT TOWARD THE UPPER LOW AND SFC LOW BECOMING VERTICALLY
STACKED. A WINDY DAY IS EXPECTED...BUT THE PCPN TYPE WILL BE ALL
SNOW AS COLD AIR IS PULLED DOWN FROM NORTHERN CANADA. HAVE ADDED A
MENTION OF BLSN AS A TIGHT PRESSURE GRADIENT MOVES OVERHEAD AS THE
SFC LOW CENTER REACHES EASTERN LAKE SUPERIOR BY 00Z MONDAY. VERY
COLD AIR IS PULLED IN BEHIND THIS SYSTEM AS IT BEGINS TO LOOSEN
ITS GRIP ON THE AREA MONDAY NIGHT. MORE LIGHT SNOW IS EXPECTED
MONDAY NIGHT BEFORE ENDING ON TUESDAY WITH THE HIGH MOVING INTO
THE AREA. LES IS POSSIBLE TUESDAY WITH A NWLY FLOW OVER LS. THE
LES ENDS TUESDAY NIGHT AS A SFC RIDGE AND DRIER AIR ARRIVE. MODELS
TRY TO BRING IN MORE LIGHT SNOW FOR WEDNESDAY WITH A SHORT WAVE
TROF CLIPPING THE INTERNATIONAL BORDER.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1140 AM CST THU NOV 20 2014

SNOW SHOWERS AND MVFR CIGS WILL CONTINUE AT KHYR THIS AFTERNOON
BUT WILL QUICKLY IMPROVE TO SKC VFR AFT 22Z. OTHERWISE....VFR SKC
OVER THE FA THROUGH THE FORECAST PERIOD.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  13   0  21  20 /   0   0   0  10
INL  10  -2  23  21 /  10   0   0  10
BRD  14  -2  23  23 /   0   0   0  10
HYR  13  -8  21  21 /  10  10   0  10
ASX  14   2  24  22 /  50  10   0  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...LAKE EFFECT SNOW ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ004.

LS...NONE.
&&

$$

SHORT TERM...BJT
LONG TERM...GSF
AVIATION...CLC





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