Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000
FXUS63 KOAX 091716
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1216 PM CDT WED APR 9 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM CDT WED APR 9 2014

SEVERAL FORECAST CHALLENGES THIS FORECAST PACKAGE. TODAY THE
PRIMARY CONCERN WILL BE FIRE WEATHER HEADLINES WITH WARM AND DRY
CONDITIONS...THEN PRECIPITATION CHANCES TONIGHT THROUGH EARLY NEXT
WEEK.

OF NOTE ON THE UPPER AIR CHARTS WAS THE MID LEVEL RIDGE BUILDING
INTO THE REGION AT H5 AND THE LARGE AREA OF WARM H85 TEMPERATURES
MAKING THEIR WAY INTO THE WESTERN PLAINS.  OUR OAX FORECAST SOUNDING
SHOWED THAT WE MIXED OUT TO 750MB WITH HIGHS IN THE UPPER 50S TO
LOWER 60S. THE LATEST SURFACE MAP SHOWED RELATIVE HIGH PRESSURE
OVER THE CWA...WITH A DEEPENING SURFACE TROF/WIND SHIFT FROM
BISMARK ND TO PIERRE SD.

TODAY...A WARM FRONT WILL MOVE EAST ACROSS THE REGION.  SOUTHWEST
WINDS AND DEEP MIXING TO H7 OR HIGHER SHOULD YIELD MAXIMUM
TEMPERATURES IN THE 80 TO 85 DEGREE RANGE. RH PROGS SHOW AND
INCREASE IN CIRRUS THROUGH THE AFTERNOON...HOWEVER WILL MAINTAIN
UNSEASONABLY WARM HIGHS IN THE 79 TO 85 DEGREES.

TONIGHT...A SURFACE COLD FRONT WILL PUSH THROUGH. THE MID
TROPOSPHERIC TROF IN SOUTHWEST CANADA AND THE PACIFIC NORTHWEST
BREAKS DOWN THE MID LEVEL RIDGE AND DRAGS THE COLD FRONT THROUGH.
BY 12Z...THE SURFACE AND H85 FRONTS ARE THROUGH THE CWA. THERE IS
GOOD MID LEVEL MOISTURE WITH THIS SYSTEM...HOWEVER LOW LEVEL
MOISTURE IS LACKING. THE STRONGEST FRONTOGENESIS TRACKS ACROSS
SOUTH DAKOTA...MINNESOTA...AND NORTHERN IOWA AND THIS IS WHERE THE
BETTER JET SUPPORT AND MID LEVEL OMEGA ARE AS WELL. RESIDUAL LIFT
PASSES THROUGH THE FORECAST AREA FROM LATE EVENING THROUGH EARLY
MORNING. THE POSITIVES ARE STEEP LAPSE RATES...INSTABILITY AND
MOISTURE IN THE MID LEVELS...THE NEGATIVES ARE THAT THE BETTER
FORCING AND MOISTURE IS TO OUR NORTH AND EAST. DUE TO
UNCERTAINTIES WITH COVERAGE...DO MENTION ISOLATED SHOWERS/THUNDER
AND THE CHANCE FOR SPRINKLES ACROSS THE FORECAST AREA DURING
PERIOD.

ALTHOUGH THE NORTH TO NORTHEAST WINDS WILL PICK UP BEHIND THE
FRONT...THESE DO NOT LAST AS BY 18Z THURSDAY SURFACE HIGH PRESSURE
IS BUILDING IN AND THE TREND WILL BE FOR DIMINISHING WINDS DURING
THE AFTERNOON. HIGHS FRIDAY WILL NOT BE NEARLY AS WARM AS
WEDNESDAY...HOWEVER STILL ABOVE NORMAL IN THE UPPER 60S AND LOWER
70S.

WARM AIR ADVECTION ENSUES AHEAD OF THE NEXT SHORTWAVE TROF EMBEDDED
IN THE NORTHWEST FLOW ALOFT.  THIS COULD TRIGGER A FEW ISOLATED
SHOWERS LATE THURSDAY NIGHT AND FRIDAY MORNING.  AGAIN...NOT REALLY
EXCITED ABOUT THE COVERAGE...SO DO ONLY MENTION ISOLATED TO
SCATTERED SHOWERS.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED APR 9 2014

THE FLOW QUICKLY RETURNS TO THE SOUTH BY FRIDAY AFTERNOON...WITH A
45KT LOW LEVEL JET DEVELOPING OVER THE WESTERN PLAINS FRIDAY NIGHT.
DEEPER H85 MOISTURE RETURNS AHEAD OF THE FRONT. THE SHORTWAVE IN THE
FLOW ALOFT WILL DRAG A WIND SHIFT INTO NORTHEAST NEBRASKA BY
SATURDAY MORNING.  THE MAIN FOCUS APPEARS TO BE OVER MINNESOTA AND
PARTS OF IOWA...HOWEVER WITH INSTABILITY/STEEP LAPSE
RATES/LIFT/FRONTAL CONVERGENCE...COULD SEE SOME ISOLATED SCATTERED
SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONT.

SATURDAY...THE GFS/EC STALL OUT THE FRONT AS THE SHORTWAVE ENERGY
PUSHES OUT OF THE AREA AND THERE IS STILL A TROF IN THE SOUTHWEST
U.S.  MOISTURE FURTHER POOLS AHEAD OF THE H85 FRONT TO AROUND 10 TO
12 DEG C.  THE FRONT PUSHES FARTHER SOUTH SATURDAY NIGHT...HOWEVER
UPPER LEVEL SUPPORT MAY BE ENOUGH TO LINGER MIXED RAIN/SNOW INTO
SUNDAY.  THERE ARE SOME DIFFERENCES BETWEEN THE GFS/EC LOCATION OF
THE FRONT SATURDAY THROUGH SUNDAY NIGHT. THE 12Z EC WAS SLOWER
WITH THE FRONT AND HAS A DEEPER SURFACE LOW RIDING ALONG THE FRONT
INTO SUNDAY. THE 00Z EC WAS IN BETTER AGREEMENT WITH THE GFS. THE
CURRENT COLLABORATED FORECAST HAS HIGH POPS FOR THE SOUTHEAST HALF
OF THE FORECAST AREA SATURDAY AFTERNOON AND EARLY EVENING AND
AGAIN SUNDAY AFTERNOON. DEPENDING ON THE FRONTAL LOCATION...THERE
COULD BE SOME .5 INCH TO 1 INCH RAINS THIS WEEKEND FOR PARTS OF
THE AREA...ESPECIALLY IF THE FRONT LINGERS. MONDAY AFTERNOON
THROUGH TUESDAY NIGHT STILL LOOK MAINLY DRY.

&&

.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1210 PM CDT WED APR 9 2014

VFR CONDITIONS ARE EXPECTED THROUGH THE ENTIRE TAF CYCLE. GUSTY
SOUTHWEST SURFACE WINDS WILL GRADUALLY DECREASE AFTER SUNSET. A
COLD FRONT WILL SLIDE INTO THE AREA TONGIHT TURNING WINDS TO THE
NORTHWEST AROUND 06Z AT KOFK AND AROUND 09Z AT KOMA AND KLNK. THIS
WILL ALSO BRING AN INCREASE IN MID CLOUDS. A FEW SPRINKLES ARE
POSSIBLE THURSDAY MORNING BUT WILL NOT MENTION IN THE TAFS.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR NEZ011-012-
     015>018-030>034-042>045-050>053-065>068-078-088>093.

IA...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR IAZ043-055-056-
     069-079-080-090-091.

&&

$$

SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...KERN



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