Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KOAX 020019
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
719 PM CDT TUE SEP 1 2015

.SHORT TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 247 PM CDT TUE SEP 1 2015

WARM...HUMID...AND SLIGHTLY UNSETTLED WEATHER WILL CONTINUE THROUGH
THE WORK WEEK. SUBJECTIVE 12Z UPPER AIR ANALYSIS INDICATES BROAD
WEST-SOUTHWESTERLY UPPER-LEVEL FLOW...WITH A DEVELOPING UPPER LOW IN
WESTERN CANADA...AND INCREASING RIDGE OVER THE EASTERN US. WEAK
UPPER LOWS WERE NOTED OVER IN AND OVER EASTERN TX/EASTERN OK...AS
WELL AS A SHORTWAVE TROUGH IN EASTERN CO/WESTERN NEB.  HIGH AT 850MB
WAS PARKED OVER THE SOUTHEAST US...WITH LOW TO THE NORTHWEST...AND
SOUTHERLY FLOW ACROSS THE PLAINS DRAWING SOME GULF MOISTURE
NORTHWARD.  WESTERN EDGE OF 850MB MOISTURE /8C+/ WAS FROM AROUND
EASTERN SD TO CENTRAL NE TO UT/AZ.  SURFACE LOW AT 19Z WAS CENTERED
IN WESTERN SD...WITH MAINLY SOUTHERLY WINDS ACROSS THE CWA...ALONG
WITH SOME HIGH CLOUDS.

MAIN FORECAST CONCERN IS PERSISTENT POTENTIAL FOR SHOWERS/A FEW
STORMS THROUGHOUT THE PERIOD...WITH SOUTHWEST UPPER-LEVEL FLOW
DEVELOPING. WESTERN US TROUGH AND EASTERN US RIDGE PATTERN WILL
PERSIST ESSENTIALLY THROUGHOUT THE FORECAST PERIOD...EXCEPT FOR
POSSIBLY FLATTENING FOR A DAY OR TWO AROUND SUNDAY/MONDAY WITH A
STRONGER SHORTWAVE PASSAGE. CWA IS ON THE EASTERN FRINGE OF THE
SOUTHWESTERLY FLOW...AND THUS WILL BE IN A BIT OF A BATTLEGROUND
BETWEEN THE INFLUENCES OF THE RIDGE AND THE TRANSIENT SHORTWAVES
THROUGH THE UPPER-LEVEL SOUTHWESTERLIES. RESULT WILL BE LOW POPS
ON JUST ABOUT EVERY DAY...BUT VERY LOW CONFIDENCE OF PRECIPITATION
MATERIALIZING ON ANY GIVEN DAY THROUGH THE WORK WEEK. A FEW
SHOWERS/STORMS MAY DEVELOP IN NORTHEAST TO CENTRAL NEB LATER THIS
AFTERNOON INTO THIS EVENING...ON THE NOSE OF THE 850MB WARM/MOIST
AIR ADVECTION AND TIED TO A PASSING SHORTWAVE TROUGH /MAINLY
CLOSER TO NORTHWEST IA/. CAMS ARE MUCH LESS ROBUST THAN
DETERMINISTIC MODELS WITH SHOWERS/STORMS TONIGHT INTO
WEDNESDAY...AND HAVE SHAVED POPS DOWN IN EXTENT AS WELL AS
SLIGHTLY LOWERING THEM DUE TO COVERAGE CONCERNS...BUT THINK THERE
IS ENOUGH POTENTIAL TO LEAVE THEM IN THROUGH THE MORNING. ANY
LINGERING SHOWERS SHOULD BE CLEAR BY AROUND MIDDAY...LEAVING FAIR
WEATHER IN THE AFTERNOON AND EVENING. SHOWERS/STORMS AGAIN ARE
POSSIBLE ON WEDNESDAY NIGHT...CLOSER TO DAYBREAK...ON THE NOSE OF
THE LOW-LEVEL JET...BUT WITHOUT A SHORTWAVE TO AID FORCING...THINK
POTENTIAL IS QUITE LOW. HAVE SCALED BACK TO JUST A SLIGHT CHANCE
MENTION IN SOUTHEAST NEB.

WARM...MOIST...AND MURKY SOUTHWEST FLOW ALOFT/SOUTHERLY FLOW IN THE
LOWER LEVELS CONTINUES THURSDAY AND FRIDAY.  MODELS DO INDICATE A
SHORTWAVE TRAVERSING THE NORTHWESTERLY FLOW ON THURSDAY
EVENING/NIGHT...AND FOR THE MOST PART...THEY KEEP CONVECTION WEST OF
THE CWA IN WESTERN TO CENTRAL NEB.  WILL TIP IN THAT DIRECTION AS
WELL...CLOSER TO THE SHORTWAVE...AND KEEP PRECIP MENTION OUT OF
THE AREA ON THURSDAY NIGHT. DID KEEP SMALL POPS IN THE NORTHERN
CWA ON FRIDAY...BUT ALSO HAVE LOW CONFIDENCE ON THESE
MATERIALIZING...AS CWA WILL BE FAIRLY WELL EAST OF THE DEVELOPING
SURFACE LOW DURING THE DAY AND LIKELY WILL BE CAPPED.

DID KEEP TEMPERATURES ON THE WARM SIDE THROUGH FRIDAY...AND KEPT
DEWPOINTS ON THE HIGH SIDE AS WELL...AS WARM AND MOIST SOUTHERLY
FLOW IN THE LOWER LEVELS WILL LIKELY PUSH TEMPS UP.  CONFIDENCE
WOULD BE OFFSET BY ANY SHOWER/STORM ACTIVITY THAT DOES MATERIALIZE
AND PROVIDE CLOUDINESS DURING THE DAY.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 247 PM CDT TUE SEP 1 2015

WITH VARYING INTENSITY AND SOUTHWARD PUSH...MODELS DO BRING AN UPPER-
LEVEL LOW ACROSS THE NORTHERN US...DRAWING THE SURFACE LOW EASTWARD
AND PUSHING COOLER AND DRIER AIR INTO THE MISSOURI RIVER VALLEY.
WEAK CHANCES OF SHOWERS/STORMS CONTINUE ON SATURDAY...MUCH LIKE
EARLIER IN THE WEEK. FRONTAL PASSAGE SEEMS MOST LIKELY ON
SUNDAY/SUNDAY NIGHT...WITH 12Z ECMWF TRENDING TOWARD A
STRONGER/COOLER/DRIER PUSH LIKE THE 12Z GFS. RESULT WOULD BE TO
STABILIZE THE AIRMASS OVER THE CWA...AND DRIVE THE CHANCES FOR
PRECIP SOUTH INTO KS/MO.  HAVE BACKED OFF POPS MONDAY NIGHT/TUESDAY
CONSIDERABLY...AND OFF OF MONDAY POPS SOMEWHAT TOO.  TEMPERATURES
WOULD TREND TOWARD BELOW-NORMAL READINGS TO START THE NEXT WORK
WEEK.

&&

.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 659 PM CDT TUE SEP 1 2015

VFR CONDITIONS ARE EXPECTED TO PREVAIL AT KOMA...KOFK...AND KLNK
THROUGH THE FORECAST PERIOD. A WEAK UPPER LEVEL SHORTWAVE TROUGH
WILL MOVE ACROSS THE DAKOTAS INTO THE MID AND UPPER MISSISSIPPI
VALLEY TONIGHT AND WEDNESDAY. SOME MID LEVEL CLOUDS AROUND 10000
FEET ARE POSSIBLE AT KOMA AND KLNK AFTER. WIDELY SCATTERED SHOWERS
AND THUNDERSTORMS MAY DEVELOP AFTER AFTER 06Z AS LOW LEVEL JET
INCREASES. MUCH OF THE PRECIPITATION MAY BECOME BETTER ORGANIZED
IN WESTERN IOWA. AT THIS TIME...HAVE INCLUED VCSH AT KOMA BETWEEN
04Z AND 14Z. BECAUSE OF THE STRENGTHENING LOW LEVEL JET...LOW
LEVEL WIND SHEAR IS LIKELY AT 2000 FEET AFTER 04Z AT
KOFK...KOMA...AND KLNK.

&&

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

$$

SHORT TERM...MAYES
LONG TERM...MAYES
AVIATION...SMITH



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.