000
FXUS63 KOAX 071132
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
532 AM CST FRI MAR 7 2014

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 330 AM CST FRI MAR 7 2014

THE CHANCE FOR PCPN TODAY INTO TONIGHT AND TEMPERATURES THE NEXT FEW
DAYS WILL PROVIDE THE MAIN FORECAST CHALLENGES.

UPPER AIR CHARTS FROM 00Z FRIDAY SHOWED THE FOLLOWING MAIN FEATURES.
AT 300 MB...TWO MAIN JET SEGMENTS WERE NOTED. ONE WAS OVER ONTARIO
(115 KNOTS) AND THE OTHER WAS BACK OVER NORTHERN CALIFORNIA (110
KNOTS). AT 500 MB...SHORTWAVE TROUGH OVER THE ROCKIES HAD 12 HOUR
HEIGHT FALLS OF UP TO 80 METERS IN NORTHERN NEVADA. AT 700 MB...
THERE WAS A WARM WEDGE WITH TEMPERATURES OF ZERO DEGREES C OR
WARMER FROM MEXICO INTO SOUTHWEST SOUTH DAKOTA. THIS WARM WEDGE
WAS ALSO EVIDENT AT 850 MB WITH TEMPERATURES OF 15 DEGREES C AS
CLOSE AS RAPID CITY AND NORTH PLATTE.

AS THE SHORTWAVE TROUGH MOVES EAST...IT WILL HELP A COLD FRONT MOVE
THROUGH THE REGION. MODELS ARE NOT VERY CONSISTENT WITH DEVELOPMENT
OF PCPN. HRRR AND MOST RECENT RUNS OF THE RAP MODEL DO NOT BRING
MUCH INTO THE FORECAST AREA THIS AFTERNOON. FOR NOW...DECIDED TO
STAY WITH A BLEND OF THE PREVIOUS FORECAST...06Z NAM AND 00Z GFS.
ALSO CONSIDERED THE 00Z ECMWF FOR DETAILS. MAIN FORCING MECHANISM
WITH THIS SYSTEM APPEARS TO BE A NARROW BAND OF ELEVATED
FRONTOGENESIS BETWEEN ABOUT 600 MB AND 700 MB. THE PCPN TYPE WILL
BE RAIN INITIALLY...THEN A MIX...THEN MOSTLY SNOW AS THE COLD AIR
DEEPENS AND MOVES SOUTHEAST BEHIND THE FRONT. SNOWFALL AMOUNTS
SHOULD BE LESS THAN HALF AN INCH. FAIRLY BRISK NORTH/NORTHWEST
WINDS WILL OCCUR BEHIND THE FRONT TODAY.

TONIGHT...PCPN CHANCES WILL BE HIGHEST THIS EVENING THEN END AFTER
09Z IN FAR SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. FOR LOWS...HAVE
STAYED A LITTLE ABOVE A BLEND OF GFS AND NAM MOS.

LITTLE OR NO PCPN IS EXPECTED SATURDAY AND SUNDAY. HIGHS SATURDAY
WILL BE BELOW NORMAL WITH COLD HIGH PRESSURE IN PLANE AND FAIRLY
POOR MIXING CONDITIONS. THAT HIGH PUSHES EAST AND WITH BETTER MIXING
WITH SOUTHWEST WINDS WE SHOULD SEE HIGHS RANGING FROM THE MID 50S TO
LOWER 60S (WITH THE WARMEST READINGS IN EASTERN NEBRASKA).

.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 330 AM CST FRI MAR 7 2014

A FAIRLY PROGRESSIVE MID TROPOSPHERIC PATTERN WILL BE IN PLACE
THROUGH THIS PERIOD. A FAIRLY STRONG RIDGE AT 500 MB WILL BUILD
INTO WESTERN CANADA BY TUESDAY...WITH A DOWNSTREAM TROUGH
STRETCHING FROM CANADA SOUTHWESTWARD INTO THE CENTRAL ROCKIES.
THIS TROUGH MOVES THROUGH THE CENTRAL PLAINS TUESDAY THROUGH
TUESDAY NIGHT...BRINGING A CHANCE FOR RAIN AND SNOW.

MONDAY WILL BE VERY MILD...PROBABLY THE WARMEST DAY OF THE WEEK
WITH HIGHS IN THE 60S. COOLER 40S ARE EXPECTED FOR HIGHS TUESDAY
AND WEDNESDAY. A SLIGHT MODERATION APPEARS LIKELY FOR LATE IN THE
WEEK AS HEIGHTS ALOFT INCREASE.

&&

.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 521 AM CST FRI MAR 7 2014

DETERIORATING CONDITIONS EXPECTED LATER THIS AFTN IN RESPONSE TO A
COLD FRONT MOVING INTO THE CNTRL PLAINS. EXPECT FROPA TO OCCUR AT
KOFK LATER THIS MORNING WITH BEST CHANCE FOR POST-FRONTAL -RASN
MIX DURING THE EARLY AFTN. AT KOMA/KLNK...FROPA TO OCCUR TWD 18Z
THIS AFTN WITH POST-FRONTAL -RASN MIX DURING THE EARLY EVENING
HOURS. MVFR CIGS LIKELY TO PREVAIL THEN INTO SAT MORNING.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...DEE