000
FXUS63 KOAX 201751
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1251 PM CDT SUN JUL 20 2014

.UPDATE...
ISSUED AT 1250 PM CDT SUN JUL 20 2014

PERSISTENT AREA OF LOW CLOUDS SHOULD CONTINUE TO MOVE NORTHEAST
AND MIX OUT THE REST OF THE AFTERNOON. ONLY MADE MINOR TWEAKS TO
THE AFTERNOON FORECAST.

&&

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 300 AM CDT SUN JUL 20 2014

...HEAT INDEX VALUES SHOULD REACH ADVISORY CRITERIA BY MONDAY AND
TUESDAY...

OVERALL...ONGOING FORECAST REMAINS IN GOOD SHAPE WITH MINOR
CHANGES EXPECTED THIS PACKAGE. MAIN CONCERNS WILL BE THE BUILDING
HEAT OVER THE NEXT THREE DAYS...WITH OPPRESSIVE SURFACE DEWPOINTS
EVENTUALLY RESULTING IN HEAT INDEX VALUES REACHING ADVISORY
CRITERIA BOTH MONDAY AND TUESDAY.

HIGHS TODAY SHOULD BE WARMER THAN YESTERDAY...REACHING THE MID
80S ACROSS WESTERN IOWA...TO THE LOWER 90S ACROSS EASTERN
NEBRASKA. WHILE SURFACE DEWPOINTS DO REACH THE LOWER 70S TODAY
MOST AREAS...HEAT INDEX VALUES WILL REMAIN GENERALLY BELOW 100.

TEMPS MONDAY SHOULD CLIMB INTO THE MID TO UPPER 90S MONDAY WHEN
DEWPOINTS SURGE INTO THE MID 70S AS CORN EVAPOTRANSPIRATION REALLY
KICKS IN. THIS WILL RESULT IN HEAT INDEX VALUES FROM 105 TO 109 IN
MOST AREAS ON MONDAY. VERY MUGGY AND HUMID CONDITIONS PERSIST INTO
MONDAY NIGHT WITH TEMPS ONLY DROPPING INTO THE MID TO UPPER 70S.

A WEAK FRONT MOVES INTO THE AREA ON TUESDAY. ALONG AND AHEAD OF
THE FRONT...HIGHS WILL AGAIN BE IN THE 95 TO 100 DEGREE RANGE...AGAIN
WITH ANOTHER DAY OF OPPRESSIVE HUMIDITY AND HEAT INDEX VALUES FROM
105 TO 109 IN THE AFTERNOON.

WE HAVE HIGHLIGHTED THE BUILDING HEAT THE LAST COUPLE OF DAYS...AND
WILL LIKELY BE ISSUING HEAT ADVISORIES LATER IN THE DAY ON SUNDAY
OR SUNDAY NIGHT FOR MONDAY/TUESDAY.

REGARDING PRECIPITATION...OPTED TO PULL THE SLIGHT CHANCE OF
THUNDERSTORMS EARLY THIS MORNING SINCE THEY ARE NOT
MATERIALIZING...IN THE ABSENCE OF ANY SIGNIFICANT FORCING.

STILL HAVE SOME CONCERN THAT ISOLATED SHOWERS/STORMS COULD DEVELOP
TONIGHT IN THE MID MISSOURI RIVER VALLEY AS THE AREA WILL BE
WITHIN THE NOSE OF A WEST/SOUTHWEST LOW LEVEL JET...WITH AN
INCREASE IN LOW/MID LEVEL MOISTURE NOTED. THE ECMWF IS THE ONLY
MODEL THAT REMAINS DRY TONIGHT. A HEALTHY CAP WILL ALSO EXIST
OVERNIGHT...THUS UNSURE IF THERE`S ENOUGH FORCING FROM THE LLJ
ALONE TO TRIGGER ANYTHING...AND WILL DEFER TO THE LATER COMPUTER
MODELS TO SEE IF THEY MAINTAIN THEIR WET TRENDS.

BEST CHANCE FOR CONVECTION STILL APPEARS TO BE MONDAY NIGHT AHEAD
OF THE COLD FRONT...WITH THE CONVERGENCE ALONG THE NOSE OF THE LOW
LEVEL JET...COMBINED WITH A VERY SUBTLE WAVE ALOFT COULD TRIGGER
ISOLATED STORMS...THAT COULD ALSO LINGER THROUGH THE DAY TUESDAY
AS THE COLD FRONT MOVES INTO THE REGION.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 300 AM CDT SUN JUL 20 2014

COLD FRONT ALONG OR JUST SOUTH OF I80 TUESDAY EVENING COULD
CONTINUE TO TRIGGER ISOLATED STORMS MAINLY TUESDAY EVENING IN
SOUTHEAST NE/SOUTHWEST IOWA.

SOMEWHAT LESS HUMID AIR AND COOLER TEMPS THEN SETTLE OVER THE
REGION ON THURSDAY BEHIND THE FRONT WITH DRY WEATHER EXPECTED.

THE UPPER RIDGE REMAINS FIRMLY IN PLACE ACROSS THE SOUTHWEST US
THROUGH THE REMAINDER OF THE FORECAST PERIOD. A COUPLE OF RIDGE
RIDER SYSTEMS COULD AFFECT THE AREA THURSDAY THROUGH FRIDAY WITH
SMALL THUNDERSTORM CHANCES. SATURDAY APPEARS DRY AT THIS TIME.

&&

.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1250 PM CDT SUN JUL 20 2014

MVFR CEILING AT KOFK SHOULD CONTINUE TO LIFT AND CLOUDS WILL
SCATTER OUT MID TO LATE AFTERNOON. AFTER THAT LOOK FOR MAINLY VFR
CONDITIONS AT ALL THREE SITES WITH SOUTH OR SOUTHEAST WINDS. SOME
VSBYS 4-6 MILES POSSIBLE LATE TONIGHT DUE TO FOG OR HAZE.

&&

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

$$

UPDATE...MILLER
SHORT TERM...DEWALD
LONG TERM...DEWALD
AVIATION...MILLER