000
FXUS63 KDLH 010004 AAA
AFDDLH

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
604 PM CST SAT JAN 31 2015

.UPDATE...
ISSUED AT 604 PM CST SAT JAN 31 2015

NEW 00Z AVIATION DISCUSSION BELOW...

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 303 PM CST SAT JAN 31 2015

MAIN CONCERNS NEXT 24 HOURS ARE THE LAKE EFFECT SNOW EXPECTED TO
EXPAND ACROSS NORTHWEST WISCONSIN THIS EVENING AND OVERNIGHT...AND
THE VERY COLD WIND CHILL VALUES EXPECTED FOR FAR NORTHERN MINNESOTA
TONIGHT.

WE HAVE BEEN WATCHING THE POTENTIAL FOR LAKE EFFECT SNOW FOR TONIGHT
FOR A FEW DAYS...WITH THE OPEN LAKE AROUND 34F/1C AND 850MB
TEMPERATURES ALOFT DROPPING TO -18C TO -20C BY 06Z TONIGHT AND NORTH
WINDS SLOWLY TURNING NORTHEAST FOR A LONGER FETCH ACROSS THE LAKE.
HOWEVER...THE VERY DRY AIR MOVING INTO THE AREA FROM THE NORTH IS A
DETRIMENT TO WHAT WOULD OTHERWISE BE A VERY FAVORABLE SET UP...AND
DO NOT EXPECT A VERY STRONG EVENT WITH MAINLY LIGHT SNOWFALL AMOUNTS.
THUS...HAVE PUT IN CHANCE TO SOME LIKELY POPS FOR THE SOUTH SHORE
AREAS FOR OVERNIGHT TONIGHT AND SUNDAY MORNING BEFORE DIMINISHING IN
THE AFTERNOON AS WINDS WEAKEN AND TURN BACK NORTH.  SNOWFALL AMOUNTS
OF AROUND AN INCH OR SO ARE POSSIBLE WHERE THE BANDS SET UP.

THE REMAINDER OF THE AREA IS LIKELY TO CLEAR OUT OR HAVE ONLY SOME
THINNER MID AND HIGH CLOUDS TONIGHT AS A STRONG WINTER STORM MOVES
ACROSS THE CENTRAL MIDWESTERN STATES.  ALONG WITH THE STRONG RIDGING
THAT WILL BE BUILDING INTO THE AREA WITH PRESSURE RISES ALL NIGHT WE
CAN EXPECT VERY GOOD RADIATIONAL CONDITIONS.  THUS...HAVE GONE WITH
MIN TEMPS ACROSS FAR NORTHERN MINNESOTA IN THE -15 TO -20 BELOW
RANGE.  UNDER THE LAKE EFFECT CLOUD COVER OF NORTHWEST WISCONSIN WE
SHOULD ONLY DROP TO BETWEEN ZERO AND 5 ABOVE.  THE LIGHT NORTH WINDS
THAT WILL CONTINUE TONIGHT SHOULD PRODUCE WIND CHILL VALUES OF -20
TO -30 OVER MOST OF NORTHERN MINNESOTA...AND HAVE PUT OUT A WIND
CHILL ADVISORY FOR TONIGHT FOR THE AREAS MOST LIKELY TO GET BELOW
-25.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 303 PM CST SAT JAN 31 2015

THE RELATIVELY QUIET WINTER WEATHER PATTERN SHOULD CONTINUE THROUGH
THE UPCOMING WEEK. NO SIGNIFICANT SNOWFALL IS FORECAST...BUT THE
MODELS ARE BEGINNING TO SHOW SOME SIGNS OF POTENTIAL LIGHT TO
MODERATE SNOWFALL OPPORTUNITIES VERY LATE IN THE WEEK AND NEXT
WEEKEND. AT THIS POINT...THESE OPPORTUNITIES FALL OUTSIDE THE
FORECAST PERIOD. A SLIGHTLY COLDER THAN NORMAL WEATHER PATTERN IS
EXPECTED FOR THE EARLY AND MIDDLE OF THE WEEK...BUT THERE COULD BE A
LITTLE MODERATION BACK TO NORMAL LATE IN THE WEEK. PARTS OF NW
WISCONSIN WILL LIKELY SEE PERIODS OF VERY LIGHT LAKE EFFECT SNOW
BECAUSE OF PERIODS OF COLD NW TO W FLOW OVER WESTERN LAKE SUPERIOR.
ACCUMULATIONS SHOULD BE VERY MINOR CONSIDERING THE RELATIVELY COLD
LAKE AND DRY NW FLOW.

SUNDAY NIGHT SHOULD BE CLEAR AND COLD AS HIGH PRESSURE MOVES THROUGH
THE REGION. LEANED ON THE COLDER ECMWF MOS GUIDANCE FOR MY MODEL
TEMPERATURE BLEND. OVERNIGHT LOWS WILL LIKELY BE WELL BELOW
ZERO...AND APPROACH -20 DEGREES OVER THE NORTH. THE LACK OF WIND
WILL LIKELY PREVENT THE NEED FOR A WIND CHILL ADVISORY.

A WEAK ARCTIC COLD FRONT WILL MOVE THROUGH THE NORTHLAND LATE
MONDAY. THIS WILL LIKELY BRING BKN/OVC LOW CLOUD COVER AND SOME SNOW
FLURRIES TO NE MINNESOTA.

THE PREVIOUS FORECAST HAD CHANCES OF LIGHT SNOW FOR
TUESDAY...PRIMARILY ACROSS THE SOUTH...BUT MOST OF THE RECENT 12Z
MODEL GUIDANCE SHIFTED THE SNOW ASSOCIATED WITH THIS SYSTEM WELL
SOUTH OF THE FORECAST AREA. THE SHIFT WAS SUBSTANTIAL ENOUGH TO
SIGNIFICANTLY CUT OUT THE PCPN CHANCES.

THERE WILL BE A REINFORCING BLAST OF ARCTIC AIR LATE TUESDAY AND
EARLY WEDNESDAY. THIS COULD BRING SOME LIGHT SNOW FLURRIES. THE
COMBINATION OF THE 5 TO 15 MPH NW WINDS AND COLD TEMPERATURES COULD
PRODUCE PERIODS OF WIND CHILLS OF -25 DEGREES OR COLDER OVER THE
NORTHERN FORECAST AREA EARLY WEDNESDAY AND WEDNESDAY EVENING.

TEMPERATURES MIGHT MODERATE THURSDAY AS SW FLOW DEVELOPS AHEAD OF AN
APPROACHING COLD FRONT. THE COLD FRONT MIGHT MOVE THROUGH THE
NORTHLAND THURSDAY NIGHT AND FRIDAY AS A CLIPPER MOVES THROUGH THE
NORTHERN PLAINS INTO THE UPPER MIDWEST. THIS COULD BRING LIGHT SNOW
TO THE FORECAST AREA. THE PCPN CHANCES ARE LOW AT THIS POINT...BUT
THAT IS BECAUSE OF HOW FAR OUT THIS SYSTEM IS IN TIME.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 604 PM CST SAT JAN 31 2015

MAIN CONCERNS WITH THIS TAF ISSUANCE INVOLVE POTENTIAL FOR LAKE
EFFECT CLOUDS AND PRECIPITATION AT DLH AND OVER NW WI TONIGHT. CLEAR
SKIES WERE GIVING WAY TO HIGH CLOUD COVER EARLY THIS EVENING
ACROSS NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN. MANNED SITES
TO THE WEST /GFK AND FAR/ WERE REPORTING CIGS IN THE 10KFT TO
20KFT RANGE. THOSE CLOUDS WILL MOVE INTO NE MN TERMINALS EARLY
THIS EVENING. LAKE EFFECT CLOUD COVER AND LIGHT SNOW WERE OBSERVED
OVER PORTIONS OF UPPER MICHIGAN...AND LOW-LEVEL WINDS ARE FORECAST
TO VEER NORTHEASTERLY THIS EVENING. THE SUBTLE CHANGE IN WIND
DIRECTION SHOULD ALLOW LOWER CIGS AND SNOW SHOWERS/FLURRIES TO
AFFECT HYR/ASX/PBH LATER TONIGHT...POSSIBLY EXPANDING WESTWARD TO
INCLUDE OLG/DYT/SUW OVERNIGHT. AT THIS POINT...OFFSHORE FLOW ALONG
THE MN NORTH SHORE SHOULD LIMIT THE CLOUDS AND CHANCE OF
PRECIPITATION AT DLH...BUT WILL NEED TO MONITOR TRENDS THIS
EVENING IN CASE OFFSHORE WINDS ARE WEAKER THAN EXPECTED. IN THAT
CASE...WOULD NEED TO INTRODUCE PREVAILING LOWER CIGS AND SNOW
SHOWERS AT DLH AS WELL...BUT FOR NOW WILL HANDLE WITH TEMPO GROUP.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  -3   9  -9  13 /  20  10   0   0
INL -22   2 -20  11 /   0   0   0  10
BRD  -1   9  -5  15 /  10  10   0   0
HYR   3  11 -12  15 /  10  10   0   0
ASX   5  11  -7  15 /  40  40  20   0

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 11 AM CST SUNDAY
     FOR MNZ010>012-018>021-026.

WI...NONE.
LS...NONE.
&&

$$

SHORT TERM...LE
LONG TERM...GROCHOCINSKI
AVIATION...HUYCK