FXUS63 KDLH 120919
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
319 AM CST SAT DEC 12 2009
.DISCUSSION...A WARM FRONT WAS LOCATED ALONG THE INTERNATIONAL
BORDER AT 08Z LEAVING THE FA IN SW FLOW. SOME CLOUDS MOVING
ACROSS THE FA AS SHORT WAVE ENERGY PASSES BY. MEANWHILE...A WEAK
COLD FRONT WAS SLIDING THROUGH EASTERN ND. ONLY SOME FLURRIES WERE
OCCURRING NEAR THE FRONT WITH THE HIGH CLOUD BASES NEAR 10K FT.
THE COLD FRONT WILL MOVE INTO THE AREA TODAY AND STALL NEAR THE
TWIN PORTS. ONLY PCPN EXPECTED TO OCCUR NEAR THE GRAND MARAIS MN
AREA WHERE THE SW FLOW AHEAD OF THE FRONT WILL INDUCE OROGRAPHIC
LIFT AND GENERATE A FEW SNOW SHOWERS.
THE FRONT WILL BE SWEPT OUT OF THE FA TONIGHT AS A STRONG CUT OFF
UPPER LOW MOVES THROUGH NORTHERN CANADA. SOME LIGHT SNOW MAY
ACCOMPANY THE FROPA...BUT SHOULD BE FAIRLY LIGHT WITH NO GOOD
MOISTURE TO WORK WITH. CAA BEHIND THE FRONT ON SUNDAY WILL SWITCH
THE SFC FLOW AROUND TO THE NW AND INITIATE SOME LES SHOWERS ALONG
THE HIGHER TERRAIN AREAS OF THE SOUTH SHORE OF LAKE SUPERIOR. WINDOW
OF OPPORTUNITY FOR LES IS SMALL AS DRIER AIR WILL END THE POTENTIAL
FOR ACCUMULATIONS BY MID AFTERNOON. HAVE CHANCE POPS TO REPRESENT
THE LES. HIGH PRESSURE BUILDS OVER THE REST OF THE FA SUNDAY.
EXTENDED...SUNDAY NIGHT THROUGH THURSDAY...
MDL GUIDANCE IN MDT/STRONG AGREEMENT THAT A SFC LOW WILL TRACK FROM
THE CENTRAL PLAINS INTO THE SRN REACHES OF THE GREAT LAKES AT
BEGINNING OF PERIOD. ACCUMULATIONS SHOULD BE MINOR ACROSS THE
NORTHERN PART OF CWA. 2 TO 5 INCHES POSSIBLE ACROSS THE CTRL TO SRN
CWA AS MAIN OMEGA COINCIDES WITH MORE FAVORABLE DGZ. ENHANCED SNOW
TOTALS SHOULD OCCUR MONDAY NIGHT ACROSS ERN WISC SNOWBELT AS DEEP
LAYER SATURATION IN SYNOPTIC SCALE FOSTERS SOME LES AS WINDS SHIFT
TO NWLY IN BDRY LAYER. DEEP LAYER DRYING ADVECTS EAST TUESDAY TO
DIMINISH WHATEVER LES MAY BE OCCURRING. ANOTHER SURGE OF COLD AIR
WILL BE DELIVERED TO THE REGION TUES/WED AS LARGE SFC HIGH PUSHES
ACROSS NRN/CTRL PLAINS. HAVE LOWERED MIN TEMPS TUESDAY NIGHT AS
RADIATIONAL COOLING OVER FRESH SNOW PACK DEVELOPS UNDERNEATH AXIS OF
SFC HIGH. WAA REGIME DEVELOPS QUICKLY WEDNESDAY WITH LATEST EC/GFS
ADVERTISING YET ANOTHER AREA OF SNOW PUSHING INTO CWA LATE WED
NIGHT/THUR. GEM GLOBAL NOT SUPPORTING THIS. WITH EXISTING
GRIDS/ZONES DRY AND SOME LACK OF AGREEMENT ON AREAL
COVERAGE/INTENSITY OF MID WEEK SYSTEM WILL LEAVE FCST AS IS FOR NOW.
WOULD SUSPECT THAT NEXT MDL CYCLE MAY REQUIRE AN UPDATE TO THUR/FRI
FCST.
&&
.AVIATION...UPDATE FOR 06Z TAFS.
WARM AIR ADVECTION EARLY THIS MORNING HAS ALLOWED A LLJ TO DEVELOP
ACROSS ERN CWA. LLWS FOR A FEW HRS AT DLH/HYR TERMINALS AS 35/40KT
WINDS SLIDE EAST THRU 12Z. OTHERWISE...VFR THRU TAF PD EXCEPT FOR
FAR N WHERE MVFR CIGS AND -SHSN ARE PSBL WITH APPROACHING CFNT SAT
NITE.
&&
.POINT TEMPS/POPS...
DLH 20 1 12 6 / 10 20 10 60
INL 14 -15 -1 -6 / 10 20 10 10
BRD 19 0 10 4 / 10 20 10 60
HYR 26 12 14 9 / 10 20 10 50
ASX 28 13 14 11 / 10 20 30 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LSZ140-
141-146-147.
SMALL CRAFT ADVISORY UNTIL 10 AM CST THIS MORNING FOR
LSZ142-143.
&&
$$
GSF/CANNON
