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000
FXUS63 KGRB 252330
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
530 PM CST SUN JAN 25 2015

UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE

.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 253 PM CST SUN JAN 25 2015

THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE BUILDING SOUTHWARD OVER LAKE SUPERIOR EARLY THIS
AFTERNOON.  A FEW POCKETS OF STRATO-CU REMAIN OVER THE FORECAST
AREA...BUT MAJORITY OF LOCATIONS HAVE CLEARED OUT.  WILL SEE A SHORT
PERIOD OF MOSTLY CLEAR SKIES THIS AFTERNOON...THEN AN AREA OF
THINNING ALTO-CUMULUS WILL MOVE SOUTHEAST ACROSS NORTHERN
WISCONSIN.  LOOKING FARTHER UPSTREAM...THE NEXT CLIPPER SYSTEM IS
MOVING SOUTHEAST INTO THE LAKE WINNIPEG REGION...AND POISED TO
ARRIVE LATE TONIGHT INTO MONDAY MORNING.  SNOWFALL POTENTIAL WITH
THIS SYSTEM IS THE MAIN FORECAST CONCERN.

TONIGHT...LINGERING AREAS OF STRATO-CU OVER CENTRAL AND NORTHEAST
WISCONSIN WILL BE FADING BY SUNSET AS INCOMING ARCTIC HIGH AND VERY
DRY AIR OVERWHELM THE LOW LEVEL MOISTURE.  POCKET OF MID-CLOUDS WILL
BE MOVING ACROSS THE FORECAST AREA AT THE START OF THE EVENING BUT
THINKING THESE CLOUDS WILL THIN/DIMINISH AS SUBSIDENCE INCREASES.
IF THIS OCCURS...THIS WILL LEAVE A FEW HOUR WINDOW FOR GOOD
RADIATIONAL COOLING OVER N-C WISCONSIN UNTIL CLOUDS INCREASE AGAIN
LATE IN THE EVENING.  WILL DROP LOW TEMPS ACROSS N-C WISCONSIN AND
THEN SHOW RISING TEMPS AFTER MIDNIGHT.  THE NEXT ALBERTA CLIPPER
WILL MAKE QUICK PROGRESS TONIGHT AND REACH THE BOUNDARY WATERS OF
NORTHERN MINNESOTA BY 12Z MON.  WARM ADVECTION AHEAD OF THE CLIPPER
WILL CAUSE MID AND HIGH CLOUDS TO LOWER OVERNIGHT...WITH A CHANCE OF
SNOW ARRIVING OVER N-C WISCONSIN BETWEEN 09-12Z.  UNCERTAINTY IS
RATHER HIGH WITH LOW TEMPS ACROSS N-C WISCONSIN...BUT WENT BELOW
GUIDANCE WITH LOWS RANGING FROM THE LOWER SINGLE DIGITS ABOVE ZERO
NORTH TO AROUND 10 ABOVE SOUTH.

MONDAY...LOW PRESSURE WILL CONTINUE TO MOVE SOUTHEAST AND WEAKEN AS
IT MOVES INTO NORTHWEST WISCONSIN BY 00Z. DECENT MID-LEVEL FGEN WILL
ACCOMPANY THE WARM ADVECTION OVER CENTRAL WISCONSIN DURING THE
MORNING BUT WILL GRADUALLY WEAKEN AS IT MOVES INTO EASTERN WISCONSIN
IN THE AFTERNOON.  WITH SNOW RATIOS AROUND 15 TO 1...NORTH-CENTRAL
AND CENTRAL WISCONSIN COULD SEE AROUND 2 INCHES OF ACCUMULATION BY
THE END OF THE DAY WHILE EASTERN WISCONSIN SHOULD SEE AROUND AN INCH
OR LESS.  THE SNOW MAY ALSO MIX WITH FREEZING DRIZZLE OVER CENTRAL
WISCONSIN BY LATE IN THE AFTERNOON AS MID-LEVEL MOISTURE BEGINS TO
PEEL OUT.  WILL INCREASE PRECIP CHANCES SUBSTANTIALLY.  HIGHS
RETURNING TO THE 20S AS WINDS SHIFT TO THE SOUTH.

.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 253 PM CST SUN JAN 25 2015

NORTHWEST UPPER FLOW WILL CONTINUE THOUGH AT LEAST
THE END OF THIS WEEK. WEAK CLIPPER SYSTEMS WILL MOVE THROUGH
MONDAY NIGHT AND AGAIN WEDNESDAY NIGHT AND THURSDAY AND AGAIN
SATURDAY. THE MIDWEEK CLIPPER SYSTEM PROBABLY HAS THE BEST CHANCE
OF PRODUCING MORE THAN AN INCH OR TWO OF SNOW DEPENDING ON HOW
MUCH PHASING THERE IS WITH SOUTHERN STREAM JET ENERGY PASSING BY
TO THE SOUTH.

THERE IS ALSO LIMITED MOISTURE WITH ALL THREE SYSTEMS SO DO NOT
EXPECT ANY BIG SNOWS THIS WEEK. UPPER HEIGHTS BUILD THROUGH MID
WEEK DESPITE THE FLOW BEING NORTHWEST. THIS SHOULD RESULT IN ABOVE
NORMAL TEMPERATURES. COLDER AIR WILL ARRIVE LATER THIS WEEK WITH
THE POSSIBILITY OF REAL ARCTIC AIR SUNDAY OR MONDAY OF THE
FOLLOWING WEEK.
&&

.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 528 PM CST SUN JAN 25 2015

NO SIG CHCS TO AVN FCST WITH THE 00Z TAFS. PATCH OF MID CLDS WL
DROP SSE ACRS THE AREA THIS EVENING...FOLLOWED BY MORE EXPANSIVE
CLD DECK THAT WL LOWER WITH TIME. SNOW AHEAD OF INCOMING SYSTEM
LOOKS TO START IN THE 14Z-18Z TIME FRAME...WITH PERHAPS SOME SHSN
OFF LAKE MICHIGAN WORKING WWD INTO LAKESHORE AREAS EARLIER.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......SKOWRONSKI