FXUS63 KOAX 220835
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
335 AM CDT FRI APR 22 2011
.DISCUSSION...
MAIN CONCERN IS TIMING BEST CHANCES FOR PRECIPITATION OVER THE NEXT
SEVERAL DAYS. MODEL AGREE THAT PATTERN SHOULD REMAIN FAIRLY ACTIVE
WITH MAINLY WEST OR SOUTHWEST MID TROPOSPHERIC FLOW FOR OUR AREA.
SHOWER AND THUNDERSTORM ACTIVITY OVER PARTS OF SOUTHWEST AND CENTRAL
NEBRASKA ASSOCIATED WITH SHORTWAVE TROUGH SHOULD CONTINUE TO MOVE
EAST THIS MORNING. THERE HAS ALSO BEEN AN INCREASE IN COVERAGE OF
SHOWERS AND THUNDERSTORMS ACROSS PARTS OF KANSAS INTO PARTS OF
SOUTHEAST NEBRASKA...IN ASSOCIATION WITH INCREASE IN LOW LEVEL
MOISTURE AND ELEVATED INSTABILITY. SURFACE ANALYSIS AT 08Z SHOWED
TWO LOW PRESSURE CENTERS TO OUR WEST. ONE WAS LOCATED IN NORTHEAST
WYOMING AND THE OTHER WAS IN THE SOUTHWEST CORNER OF KANSAS. THERE
APPEARED TO BE A DOUBLE WARM FRONTAL STRUCTURE WITH THE SOUTHERN
LOW. 00Z MODELS WERE IN DECENT AGREEMENT THAT BOTH LOWS WILL MOVE
EASTWARD THIS MORNING...WITH A OCCLUDED FRONT BETWEEN THE LOWS ALSO
PUSHING EAST ACROSS OUR AREA. LEFT PRECIPITATION CHANCES MOSTLY IN
THE 50 TO 70 PERCENT RANGE UNTIL 18Z TODAY...THEN WENT WITH CHANCES
MAINLY LESS THAN 25 PERCENT THIS AFTERNOON. HIGHS TODAY WILL DEPEND
ON HOW FAST THE CLOUDS CLEAR OUT AND HOW STRONG WINDS GET. HAVE
TEMPERATURES REACHING THE UPPER 50S TO MID 60S BY MID AFTERNOON.
IT APPEARS THAT PRECIPITATION TONIGHT WILL STAY MOSTLY TO OUR NORTH
AND SOUTH...WITH WEST OR NORTHWEST WINDS BRINGING IN DRIER AIR. WEAK
HIGH PRESSURE SHOULD BUILD ACROSS THE FORECAST AREA SATURDAY. MODEL
HINT AT POSSIBLE SHOWER ACTIVITY SATURDAY AFTERNOON OVER PORTIONS OF
SOUTHEAST NEBRASKA WITH AN INCREASE IN MID LEVEL MOISTURE AND LIFT.
FOR NOW JUST HAVE A SLIGHT CHANCE OF SHOWERS FOR THAT SINCE DEEPER
MOISTURE AND INSTABILITY STAY MUCH FARTHER SOUTH.
A TROUGH WILL START TO DIG OVER THE ROCKIES SATURDAY NIGHT AND
SUNDAY. THIS SHOULD HELP PULL 850 MB MOISTURE BACK NORTH INTO THE
AREA...WITH SOME INSTABILITY MAKING ITS WAY INTO SOUTHEAST NEBRASKA.
WENT WITH A CHANCE OR SLIGHT CHANCE OF MAINLY SHOWERS MOSTLY FOR THE
SOUTHERN 2/3 OF THE AREA...WITH ISOLATED THUNDERSTORMS POSSIBLE NEAR
THE KANSAS AND MISSOURI BORDERS. CHANCES LOOK BETTER MONDAY INTO
MONDAY NIGHT AS THE SHORTWAVE TROUGH MOVES OUT INTO THE PLAINS WITH
A NEGATIVE TILT. MODEL DIFFERENCES BECOME LARGER BY ABOUT TUESDAY...
SO CONFIDENCE STARTS TO DROP OFF. FOR NOW HAVE KEPT THE PERIOD FROM
TUESDAY NIGHT THROUGH THURSDAY MAINLY DRY.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
BROAD AREA OF IFR AND LIFR CIGS AND VSBYS LOCATED ACROSS MUCH OF
KANSAS INTO NORTHWEST MISSOURI AT 06Z WITH WARMER SURFACE DEW POINTS
SPREADING NORTH. THESE LOW CIGS AND VSBYS ARE EXPECTED TO ADVECT
INTO EASTERN NEBRASKA THROUGH 18Z IN ADVANCE OF A COLD FRONT. SOME
LIGHT DRIZZLE OR LIGHT RAIN ALSO POSSIBLE AT TIMES THROUGH 12Z.
CONDITIONS IMPROVE AFTER 18Z WITH PASSAGE OF FRONTAL BOUNDARY AND
DRIER AIR MOVING INTO THE AREA ON GUSTY WEST WINDS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
DISCUSSION...MILLER
AVIATION...FOBERT