FXUS63 KOAX 222046
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
346 PM CDT MON AUG 22 2011
.SHORT TERM...TONIGHT
SCATTERED SHOWERS OVER WESTERN IOWA ENDED EARLIER THIS MORNING...WITH
CLOUD COVER QUICKLY ERODING AND PARTLY CLOUDY SKIES PREVAILING THIS
AFTERNOON. QUESTION FOR TONIGHT REMAINS CHANCES FOR CONVECTION AND
SEVERE/FLOODING RISK.
LOW LEVEL JET IS SETTING UP OVER CENTRAL KANSAS AND CENTRAL NEBRASKA
AND WILL MOVE EAST AND INTERACT WITH WEAK WAVE CURRENTLY MOVING
ACROSS EASTERN SOUTH DAKOTA. MID LEVEL TEMPERATURES HAVE BEEN
WARMING...KEEPING A CAP IN PLACE...EVEN WITH 70 DEGREE DEW POINTS
ADVECTING IN. THINK THAT THIS CAP WILL HOLD FOR THE LATE AFTERNOON
HOURS...ALTHOUGH SOME CONVECTION COULD DEVELOP ACROSS SOUTHEAST
SOUTH DAKOTA AND MOVE INTO THE AREA THIS EVENING. HAVE CONTINUED
CHANCE POPS MENTION THIS EVENING INTO THE OVERNIGHT HOURS...BUT
ACTIVITY WILL DECREASE THROUGH THE NIGHT.
NEXT CONCERN IS WITH THE POTENTIAL FOR FOG DEVELOPMENT. WITH
PORTIONS OF OMAHA RECEIVING OVER 4 INCHES OF RAIN LAST NIGHT...AND
RELATIVELY HIGH DEW POINTS...AT LEAST PATCHY FOG IS NOT OUT OF THE
QUESTION...AND HAVE ADDED TO THE GRIDS AFTER 3 AM.
.LONG TERM...TUESDAY THROUGH MONDAY
HOT CONDITIONS ON TAP FOR THE AREA ON TUESDAY WITH WAA ALOFT
CAPPING ANY CONVECTION AND SFC DEW POINTS LINGERING IN THE 65 TO
75 DEGREE RANGE. THIS WILL DRIVE HEAT INDICES TO AROUND 100
DEGREES IN MANY AREAS WITH LOCAL VALUES TOPPING OUT AROUND 105
ALONG THE MISSOURI RIVER WHERE SFC DEW POINTS WILL BE THE HIGHEST.
HAVE OPTED TO HOLD OFF ON ANY HEAT ADVISORIES ATTM AS COVERAGE OF
TEMPS ABOVE 105 APPEARS ISOLATED...BUT WILL BE SOMETHING WE WILL
CONTINUE TO MONITOR OVER THE NEXT 12 TO 18 HOURS.
CONVECTIVE POTENTIAL WILL ALSO BE DOWN THROUGH THURSDAY WITH
CAPPING INVERSION IN PLACE UNDER A BUILDING RIDGE OF HIGH
PRESSURE. HOWEVER...A FEW WEAK WAVES STILL POISED TO PASS
TO OUR NORTH...WITH THE MOST SIGNIFICANT OF THE BUNCH ARRIVING LATE
TUESDAY NIGHT. THIS WILL SEND AN ASSOCIATED SFC FRONT SOUTH ACROSS
THE REGION...SCOURING OUT THE DEEPER SFC MOISTURE...AND DROPPING
TEMPS ABOUT 2 TO 4 DEGREES ON AVERAGE FOR WEDNESDAY AFTERNOON.
MOISTURE STARTS TO RETURN BY THURSDAY...ALTHOUGH CONDITIONS
EXPECTED TO REMAIN DRY FOR THE DAYLIGHT HOURS. MODELS HINTING AT
ANOTHER WAVE PASSING THROUGH THE RIDGE BY THURSDAY NIGHT...BEST PICKED
UP IN THE PV15 FIELDS. THIS MAY TRIGGER A ROUND OF NOCTURNAL CONVECTION
LATE THURSDAY NIGHT AND FRIDAY MORNING AND WILL START TO SLOWLY
INCREASE POPS THROUGH THIS PERIOD.
NORTHWEST FLOW THEN SETS BACK UP AS WE MOVE THROUGH THE WEEKEND WITH
THE UPPER LEVEL RIDGE SHIFTING BACK TO THE WEST. EXPECT ANOTHER
ROUND OF ALMOST DAILY CONVECTION FRIDAY THROUGH MONDAY IN A
MOIST AND UNSTABLE ENVIRONMENT. ATTM...THE STRONGEST WAVE WILL
ARRIVE LATE SUNDAY AND SUNDAY NIGHT...WHICH COULD TRIGGER ANOTHER
ROUND OF STRONG TO SEVERE CONVECTION.
TEMPS WILL BE RUNNING NEAR TO SLIGHTLY ABOVE SEASONAL NORMS THROUGH
THE PERIOD WITH THE EXCEPTION BEING TOMORROW AFTERNOON...WHEN
READINGS WILL BE A GOOD 10 DEGREES ABOVE NORMAL FOR MOST
LOCATIONS.
&&
.AVIATION...
FOR THE 18Z TAFS...
SCATTERED CU DEVELOPED AT KOFK THIS MORNING...AND HAS SLOWLY LIFTED
THROUGH THE AFTERNOON. SOME QUESTION WITH TS DEVELOPMENT...AND DUE
TO LOW CONFIDENCE AT ANY ONE TAF SITE...DID NOT INCLUDE ATTM. FOG
DEVELOPMENT LOOKING MORE LIKELY...AND INCLUDED MVFR VSBYS AFTER
23/08Z...AND WILL SLOWLY LIFT AFTER 23/14Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
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