000
FXUS63 KOAX 211732
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1232 PM CDT TUE MAY 21 2013

.DISCUSSION...
BUMPED UP CLOUD COVER SIGNIFICANTLY FROM PREVIOUS FORECAST AND
DROPPED TEMPS JUST A COUPLE OF DEGREES. ALSO BROUGHT CHANCE OF
SHOWERS A LITTLE FURTHER SOUTH WHERE CYCLONIC FLOW IS A LITTLE
STRONGER.

&&

.AVIATION...18Z TAFS FOR KOMA...KLNK AND KOFK. VFR CONDITIONS
EXPECTED AT KOMA/KLNK...BUT LIKELY BECOMING MVFR BY 00-03Z...WHICH
SHOULD CONTINUE THROUGH THE REMAINDER OF THE FORECAST. KOFK WILL
LIKELY REMAIN MVFR THROUGH 00-03Z...WITH SPOTTY SHOWERS IN THE
VICINITY OF THE TAF SITE...THEN BECOMING IFR BY 06-09Z. WINDS WILL
BE WEST SOUTHWEST...THEN NORTHWEST...WITH SUSTAINED SPEEDS 12 TO
15 KNOTS...GUSTS UP TO 25 TO 28 KNOTS THROUGH 23-01Z.

&&

.PREV DISCUSSION... /ISSUED 323 AM CDT TUE MAY 21 2013/

DISCUSSION...
QUIET WEATHER ACROSS THE AREA THIS MORNING AS UPPER LOW SPINS
NEARBY.  SUBJECTIVE 00Z UPPER AIR ANALYSIS INDICATES BROAD UPPER LOW
CENTERED IN NORTHEAST SD/SOUTHEAST ND...WITH UPPER-LEVEL RIDGE FROM
NORTHERN CA THROUGH CENTRAL SASK.  UPPER-LEVEL JET STREAK UP TO 95KT
EXTENDED FROM TX/OK PANHANDLES TO NORTHWEST MO. DEEP 850MB LOW WAS
CENTERED IN EASTERN ND/NORTHWEST MN...WITH TRAILING COLD FRONT
THROUGH CENTRAL NEB/CENTRAL KS/WESTERN OK...AND WARM FRONT EXTENDING
FROM LOW ACROSS NORTHERN MN/NORTHERN WI/UP OF MI.  850MB DEWPOINTS
OF 8C+ COVERED THE BROAD AREA AHEAD OF THE FRONTS...WITH DRIER AIR
ALSO INTO NEB/IA/NORTHEAST KS/NORTHWEST MO.  SURFACE LOW AT 07Z WAS
CENTERED IN NORTHEAST SD...WITH TRAILING COLD FRONT ALONG THE MO
RIVER VALLEY.

MAIN FORECAST CONCERNS INCLUDE POTENTIAL FOR SHOWERS IN THE
NORTHEAST CWA TONIGHT/WEDNESDAY...THEN THUNDERSTORM POTENTIAL FRIDAY
THROUGH MONDAY NIGHT.  FORECAST SOUNDINGS INDICATE MORE STABILITY
TODAY THAN YESTERDAY...AND THINK CWA WILL AVOID SHOWERS DURING THE
DAY...THOUGH CLOUDS WILL INCREASE.  MAY SEE A SHOWER SKIRT THE
NORTHEAST CWA TONIGHT AS UPPER LOW DROPS OUT OF THE DAKOTAS TOWARD
NORTHWEST IA...BUT THINK SOUNDINGS STILL LOOK TOO STABLE FOR
THUNDER...AND HAVE KEPT PRECIP MENTION LIMITED TO SHOWERS.
WEDNESDAY NIGHT AND THURSDAY LOOK QUIET AS UPPER LOW MOVES SLOWLY
EASTWARD...WITH MID- TO UPPER-LEVEL RIDGING MOVING INTO THE CENTRAL
PLAINS.  TEMPS WILL REMAIN ON THE COOLER SIDE THROUGH THURSDAY...BUT
AS SOUTHERLY FLOW RETURNS TO THE AREA FRIDAY...TEMPERATURES WILL
MODERATE TO NEAR OR ABOVE NORMAL.

WHILE UPPER-LEVEL RIDGING IS EXPECTED TO LINGER OVER THE CENTRAL US
THROUGH THE WEEKEND...A MID-LEVEL WARM FRONT IS PROGGED TO DEVELOP
ACROSS THE AREA ON SATURDAY. ECMWF PROG INDICATES FRONT WOULD THEN
SAG SOUTHWARD ON SUNDAY...WHILE GFS HINTS AT FRONT LIFTING NORTH.
WARM AIR ADVECTION ON FRIDAY AFTERNOON/EVENING COULD BE ENOUGH TO
KICK UP SOME SHOWERS/THUNDERSTORMS...WITH ADDITIONAL SHOWERS/STORMS
ALONG THE FRONT ON SATURDAY.  WOULD EXPECT A DRY PERIOD OR TWO AS
FRONT SLIPS SOUTHWARD OUT OF THE AREA...WITH THUNDERSTORM ACTIVITY
FOCUSING ON THE HIGH PLAINS AS WELL AS IN A CORRIDOR ALONG THE
FRONT.  MODEL BLENDS HAVE SPRAYED THE ENTIRE EXTENDED PERIOD WITH
CHANCE POPS...BUT HAVE TRIED TO PULL BACK TO SLIGHT CHANCE IN
PERIODS THAT LOOK LESS FAVORABLE FOR SHOWERS/STORMS.  UNCERTAINTY
INCREASES FOR MONDAY/TUESDAY...AS BEST FORCING FOR STORMS STILL
LOOKS TO REMAIN WEST OF HERE...BUT RIDGE BEGINS TO WEAKEN AND WAVES
MOVE THROUGH THE RIDGING.

MAYES

&&

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

$$

DEWALD