FXUS63 KOAX 042258 AAA
AFDOAX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
558 PM CDT WED MAY 4 2011
.UPDATE...
UPDATED TO ALLOW WIND ADVISORY TO EXPIRE. NO OTHER CHANGES.
&&
.PREV DISCUSSION... /ISSUED 328 PM CDT WED MAY 4 2011/
SHORT TERM...TONIGHT.
COLD FRONT MOVES THROUGH THE AREA OVERNIGHT WITH A CHANCE OF SHOWERS
AND A FEW THUNDERSTORMS. INSTABILITY RATHER LIMITED ON FORECAST
SOUNDINGS SO STORMS MAY BE ISOLATED. EXPECT GUSTY SOUTHEAST TO SOUTH
WINDS TO DIMINISH AS FRONT APPROACHES THEN SHIFT TO NORTHWEST AFTER
PASSAGE.
LONG TERM...THURSDAY THROUGH WEDNESDAY.
TEMPERATURES AND PRECIPITATION CHANCES WILL BE THE PRIMARY FORECAST
CONCERNS FOR THE NEXT SEVERAL DAYS. TEMPERATURES WILL BE A LITTLE ON
THE COOL SIDE THURSDAY BUT AFTER THAT THINGS LOOK WARMER WITH AT OR
ABOVE NORMAL TEMPERATURES FRIDAY THROUGH TUESDAY.
A COLD MID TROPOSPHERIC TROUGH WILL CONTINUE TO MOVE EAST ACROSS THE
AREA THURSDAY WITH SCATTERED INSTABILITY SHOWERS AND A FEW ISOLATED
THUNDERSTORMS POSSIBLE DURING THE DAY. 12Z MODELS SHOWED 500 MB
TEMPERATURES AROUND -22 TO -26 C THURSDAY...SO LAPSE RATES WILL BE
STEEP. THE PATTERN IS SUGGESTIVE OF POSSIBLY SEEING A BIT OF GRAUPEL
OR SMALL HAIL WITH THE STRONGEST CELLS. WE HAVE SEEN THAT A FEW TIMES
RECENTLY. EXPECT THAT THIS WILL FADE AWAY QUICKLY AT AT LEAST FOR
NOW DID NOT MENTION ANY PRECIPITATION INTO THURSDAY EVENING. THAT
COLD MID LEVEL TROUGH WILL MOVE OFF TO THE EAST FRIDAY...WITH OUR
AREA IN RELATIVELY FAST NORTHWEST FLOW THAT FLATTENS AND BECOMES
MORE ZONAL BY SATURDAY NIGHT. ONE FAST MOVING DISTURBANCE COULD
BRING SOME SHOWERS/THUNDERSTORMS FOR FRIDAY AFTERNOON AND EVENING.
GUSTY SOUTH WINDS FRIDAY SHOULD PULL LOW LEVEL MOISTURE NORTHWARD
WITH 850 MB DEWPOINTS EXPECTED TO REACH 5-10 DEGREES CELSIUS AHEAD
OF A COLD FRONT THAT WILL PUSH THROUGH.
FARTHER WEST...A 500 MB TROUGH WILL BE DIGGING IN OVER THE WESTERN
UNITED STATES FROM SUNDAY THROUGH MONDAY. THIS SHOULD ALLOW WARM
AND MOIST LOW LEVEL AIR WILL MOVE IN FROM THE SOUTH. THE 12Z RUNS OF
THE GFS AND ECMWF WERE IN DECENT AGREEMENT WITH THE LARGE SCALE
PATTERN AT LEAST THROUGH 12Z TUESDAY...AND FORECASTER CONFIDENCE ON
THIS ACTUALLY HAPPENING IS A LITTLE ABOVE NORMAL. IT APPEARS THAT
THE PATTERN WILL BE ACTIVE AT TIMES FROM LATE SATURDAY NIGHT INTO
WEDNESDAY FOR PARTS OF THE CENTRAL PLAINS. DYNAMICS AND MOISTURE
SHOULD BE HIGH ENOUGH FOR SOME SEVERE STORMS...BUT THE DETAILS ARE
STILL NOT CLEAR AT THIS TIME. HAVE HIGHS FORECAST TO BE MOSTLY IN
THE 70S FRIDAY AND SATURDAY...75 TO 85 SUNDAY THROUGH TUESDAY AND
THEN COOLER (65 TO 75) WEDNESDAY.
AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
STRONG SOUTHEAST WINDS AHEAD OF A COLD FRONT WILL GRADUALLY DIMINISH
AFTER 00Z AS FRONT APPROACHES AND SURFACE HEATING CUTS OFF. STILL
SOME CHANCE OF SHOWERS AND A FEW THUNDERSTORMS ALTHOUGH FORECAST
SOUNDINGS SHOW LIMITED INSTABILITY OVERNIGHT. OTHERWISE...VFR
CONDITIONS EXPECTED TO PREVAIL.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
MILLER