FXUS63 KOAX 092100
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
300 PM CST SUN JAN 9 2011
.SHORT TERM...TONIGHT THROUGH WEDNESDAY.
UPPER LEVELS REMAIN THE PRIMARY FOCUS FOR TWO SIGNIFICANT WEATHER
SYSTEM THIS AFTERNOON. A BROAD UPPER LOW OVER THE NORTHERN ROCKIES
WAS SPINNING SHORT WAVE ENERGY INTO THE CENTRAL PLAINS AND
PRODUCING SNOW FROM THE CENTRAL AND NORTHERN ROCKIES INTO THE
CENTRAL PLAINS. A SECOND WAVE WAS MOVING ACROSS THE DEEP SOUTH
AND CREATING HAVOC THERE AS SNOW AND FREEZING RAIN SPREAD EAST
WITH THE SYSTEM.
GENERAL FORECAST TRENDS LOCALLY UNCHANGED WITH THIS FORECAST AS
SNOW IS EXPECTED TO CONTINUE INTO MONDAY NIGHT THEN PULL EAST OF
THE AREA ON TUESDAY. SNOWFALL IN THE 6-10 INCH RANGE STILL ON
TRACK FOR THE AREA BY TUESDAY MORNING. VERY COLD TEMPERATURES
FOLLOW THE FRESH SNOW COVER TUESDAY AND BEYOND AS ARCTIC HIGH
PRESSURE BUILDS INTO THE REGION. WINDCHILL HEADLINES LIKELY FOR
THAT TIME PERIOD IN LATER FORECASTS AS COLDEST TEMPERATURES SO FAR
THIS SEASON EXPECTED.
DID ADJUST WINDS UP A BIT BEHIND THE SURFACE TROUGH MONDAY NIGHT
AND TUESDAY TOWARD THE 12Z EURO BUT LITTLE CHANGE ELSEWHERE IN THE
SHORT TERM FORECAST.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY.
MAIN FORECAST CONCERN IN EXTENDED PERIOD CONTINUES TO FOCUS ON
TEMPERATURES. WEAK UPPER RIDGING SHOULD BRING SOMEWHAT MODERATING
TEMPS TOWARD THE END OF THE WEEK BEFORE ANOTHER TROUGH DROPPING FM
SRN CANADA TWD GREAT LAKES SHOVES ANOTHER ARCTIC FRONT THROUGH CWA.
12Z GFS CONTS TREND OF PREVIOUS RUNS IN SHIFTING FIRST ARCTIC HIGH
EWD A TOUCH QUICKER THAN ECMWF...00Z ECMWF IN THIS CASE...BUT THE
LATTER MODEL HAD SPED THINGS UP A BIT. THUS INCREASED SKY COVER
FASTER THU AND BUMPED UP THU AM LOWS A BIT. OTHERWISE LTL CHANGES
TO TEMPS MADE IN THU/FRI PD AS WARM ADVCTN CONTS INTO FRI BEFORE
NEXT ARCTIC FRONT PUSHES THROUGH AREA. KEPT IN SMALL SNOW CHCS
FRI/FRI NGT AND EXTENDED THEM INTO SAT/SAT NGT...GENERALLY ALL BUT
SWRN ZONES. 12Z GFS AND TO SOME DEGREE 00Z ECMWF SUGGESTED PSBL
DUAL FRONTAL PASSAGE ACROSS CWA WITH MAIN ARCTIC FRONT FRI NGT.
MOST OF THE FORCING REMAINS TO OUR N...BUT ISENTROPIC UPGLIDE AND
INITIAL COLD CLOUD TEMPS COULD SQUEEZE SOME LIGHT SNOW OUT. FELT
12Z MEX NUMBERS WERE POSSIBLY INFLUENCED BY CLIMO ON SAT THUS KEPT
THEM MOSTLY BELOW THOSE VALUES. 00Z ECMWF QUICKLY MODERATED TEMPS
ON SUNDAY WHILE 00Z GFS MEAN DID SO BRIEFLY LATE SAT. FEEL
OPERATIONAL 12Z GFS MAY END UP BEING RIGHT BUT ATTM ALLOWED FOR SOME
POSSIBILITY OF ECMWF VERIFYING AND THUS KEPT TEMPS A LTL WARMER THAN
MEX NUMBERS ON SUNDAY.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
TAF FORECASTS DOMINATED BY THE CURRENT WINTER STORM MOVING THROUGH
THE MIDWEST WITH CONTINUOUS SNOWFALL. GENERALLY EXPECT LIGHT SNOW
AND VISIBILITIES OF 3-5 MILES THROUGH 18Z...WITH BANDS OF HEAVIER
SNOW AND VISIBILITIES DOWN TO 1/2 MILE AT TIMES. CIGS WILL ALSO
FALL TO AROUND 500 FEET IN THESE HEAVIER BANDS. VERY CHALLENGING TO
DETERMINE WHEN SPECIFIC BANDS WILL MOVE OVER THE TAF SITES...
THEREFORE CONFIDENCE IN TIMING OF THE LIFR CONDITIONS IS LOW.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 6 AM CST TUESDAY FOR NEZ034-044-
045-051>053-066>068-078-088>093.
WINTER WEATHER ADVISORY UNTIL 6 PM CST MONDAY FOR NEZ011-012-
015>018-030>033-042-043-050-065.
IA...WINTER WEATHER ADVISORY UNTIL 6 AM CST TUESDAY FOR IAZ043-055-
056-069-079-080-090-091.
&&
$$
FOBERT/CHERMOK/NIETFELD