954
FXUS63 KOAX 230418
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1118 PM CDT TUE SEP 22 2026
KEY MESSAGES
- THERE IS A 20-40% CHANCE OF SHOWERS IN PORTIONS OF EASTERN
NEBRASKA WEDNESDAY, BUT EXPECT MORE DRY TIME THAN WET.
- WIDESPREAD SHOWER AND STORM CHANCES RETURN WEDNESDAY NIGHT
AND LAST THROUGH SATURDAY, WITH CHANCES PEAKING AT 80-90%
DURING THE OVERNIGHT AND MORNING HOURS EACH DAY.
- COOL WEATHER WILL STICK AROUND WITH THE RAIN CHANCES, FOLLOWED
BY A BRIEF WARMUP AND DRY PERIOD ON SUNDAY.
- STORM CHANCES RETURN EARLY NEXT WEEK. SATURATED SOIL COMBINED
WITH POTENTIAL FOR HEAVY RAIN MAY YIELD A FLOODING THREAT.
DISCUSSION
ISSUED AT 1118 PM CDT TUE SEP 22 2026
WATER VAPOR IMAGERY THIS EVENING SHOWED A SHORTWAVE TROUGH
SLIDING ACROSS NORTHEAST NE INTO WESTERN IA WITH AN UPPER LEVEL
RIDGE AXIS JUST TO OUR WEST. SAID SHORTWAVE ALONG WITH WARM AIR
ADVECTION AND SOME WEAK FRONTOGENESIS ALOFT WAS LEADING TO
SHOWERS AND A FEW STORMS ACROSS THE EASTERN SANDHILLS. THESE
WILL SLOWLY CONTINUE EASTWARD, THOUGH HAVE SHOWN A DIMINISHING
TREND AS THEY HAVE DONE SO OWING TO LESS INSTABILITY THIS WAY,
SO NOT EXPECTING THEM TO AMOUNT TO MUCH IN OUR AREA. HOWEVER,
ADDITIONAL DEVELOPMENT IS EXPECTED OVERNIGHT AS MOISTURE
TRANSPORT RAMPS UP WITH LATEST SHORT TERM GUIDANCE IN DECENT
AGREEMENT OF AT LEAST SOME SPOTTY SHOWERS LINGERING ACROSS
NORTHEAST NE INTO THE AFTERNOON. A FEW SOLUTIONS EVEN SHOW THOSE
SHOWERS EXTENDING AS FAR SOUTH AS THE KS BORDER. AS IT STANDS,
HAVE 30-40% CHANCES IN FAR NORTHEAST NE AND 20% CHANCES
EXTENDING SOUTH FROM THERE, BUT DIMINISHING AS THEY PUSH EAST
TOWARD LINCOLN AND OMAHA. IN GENERAL, STILL EXPECT MUCH MORE DRY
TIME THAN WET DURING THE DAY WEDNESDAY AS THAT AFOREMENTIONED
RIDGE AXIS PUSHES EAST THROUGH THE AREA.
ON ITS HEELS, THOUGH, WILL BE A STEADY STREAM OF SHORTWAVE
ENERGY OUT OF THE DESERT SOUTHWEST, WARM AIR ADVECTION, AND
MOISTURE TRANSPORT THAT WILL LEAD TO PERSISTENT RAIN CHANCES
LASTING INTO SATURDAY. CHANCES ACROSS MOST OF THE AREA NEVER DIP
BELOW 40% IN THAT PERIOD AND GENERALLY PEAK AROUND 80-90% IN
THE OVERNIGHT/MORNING HOURS. WITH LIMITED INSTABILITY, NOT
EXPECTING MUCH IN THE WAY OF THUNDERSTORMS, THOUGH WITH
PRECIPITABLE WATER VALUES IN THE 1.50-1.75+ INCH RANGE
(APPROACHING THE 99TH PERCENTILE OF CLIMATOLOGY FOR THIS TIME OF
YEAR) THERE COULD BE SOME PERIODS OF VERY EFFICIENT RAIN
PRODUCTION. TOTALS THROUGH THAT PERIOD LOOK TO BE IN THE 1-2"
RANGE FOR MOST OF THE AREA. TEMPERATURES ALSO LOOK TO REMAIN ON
THE COOLER SIDE, WITH HIGHS IN THE 60S TO AROUND 70 THROUGH
FRIDAY. ASSUMING PRECIP TAPERS OFF BY SATURDAY AFTERNOON, WE
SHOULD SEE SOME MID TO UPPER 70S RETURN TO THE AREA. UPPER LEVEL
RIDGING WILL BUILD IN ON SUNDAY AND LEAD TO A DRY AND WARMER
DAY WITH A FEW SPOTS IN SOUTHEAST NE AND SOUTHWEST IA MAKING A
RUN AT 80 DEGREES.
HEADING INTO EARLY NEXT WEEK, THERE IS GOOD AGREEMENT THAT
SHOWER AND STORM CHANCES WILL RETURN, BUT THERE REMAINS QUITE A
BIT OF SPREAD IN TIMING OF THOSE CHANCES. THE GENERAL IDEA IS
THAT THE UPPER LEVEL RIDGE PUSHES OFF TO THE EAST WITH SOUTHERLY
FLOW ALLOWING A GOOD PLUME OF GULF MOISTURE TO PUSH INTO THE
AREA. IN ADDITION, SOME GUIDANCE HINTS THAT SOME TROPICAL
MOISTURE OUT OF THE PACIFIC ON THE EDGES OF HURRICANE POLO COULD
WORK ITS WAY TOWARD THE AREA. EVENTUALLY, A POTENT SHORTWAVE
TROUGH PUSHES STRAIGHT EAST OUT OF CA, SPINNING UP A SURFACE LOW
EAST OF THE ROCKIES, WITH THE SYSTEM EVENTUALLY MOVING THROUGH
THE FORECAST AREA AND GIVING US WIDESPREAD SHOWER AND STORM
CHANCES. AGAIN, TIMING OF THIS WAVE IS STILL UP IN THE AIR, BUT
IT LOOKS TO BE SOMETIME MONDAY OR TUESDAY, WITH MAYBE A SLIGHT
TREND TOWARD BEING LATER. GIVEN THE POTENTIAL TROPICAL MOISTURE
PLUME IN PLACE WITH A LITTLE INSTABILITY AND THE EXPECTED
RAINFALL A FEW DAYS PRIOR FURTHER SATURATING THE GROUND, A
FLOODING THREAT COULD DEVELOP. IN ADDITION, GIVEN THE STRENGTH
OF THE SYSTEM, THERE WILL LIKELY BE SOME DECENT SHEAR IN PLACE,
WHICH COULD YIELD A SEVERE THUNDERSTORM THREAT. FOR WHAT IT'S
WORTH, MACHINE LEARNING SEVERE WEATHER GUIDANCE IS STARTING TO
SUGGEST AT LEAST A 5% CHANCE OF SEVERE STORMS BY MONDAY. WOULD
EXPECT THAT TO INCREASE A BIT SOMEWHERE IN THE REGION AS
ENSEMBLE GUIDANCE COMES INTO BETTER AGREEMENT ON SYSTEM TIMING.
OVERALL, STILL A LOT OF DETAILS TO WORK OUT, BUT EARLY NEXT WEEK
WILL BE A TIME PERIOD TO KEEP AN EYE ON.
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
ISSUED AT 639 PM CDT TUE SEP 22 2026
MVFR TO IFR CEILINGS ARE EXPECTED TO BUILD IN AGAIN OVERNIGHT,
THOUGH CHANCES FOR FOG/DRIZZLE AND LOW VISIBILITY ARE LOOKING
LOWER THAN PAST NIGHTS. THAT SAID, COULD SEE A FEW SHOWERS NEAR
OFK ANYTIME AFTER 04Z THROUGH MUCH OF WEDNESDAY MORNING, BUT
GIVEN SPOTTY NATURE AND 20% CHANCES, DIDN'T INCLUDE MENTION AT
THIS TIME. OTHERWISE, CEILINGS SHOULD GRADUALLY SCATTER OUT
DURING THE DAY WEDNESDAY. WINDS WILL GO FROM EASTERLY TO
SOUTHEASTERLY THROUGH THE PERIOD, GENERALLY ON EITHER SIDE OF 10
KTS, WITH PERHAPS A FEW GUSTS AROUND 20 KTS AT OFK.
OAX WATCHES/WARNINGS/ADVISORIES
NE...NONE.
IA...NONE.
DISCUSSION...CA
AVIATION...CA
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