FXUS63 KOAX 232008
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
308 PM CDT SAT JUL 23 2011
.SHORT TERM...TONIGHT THROUGH TUESDAY. THE AREA REMAINS WITHIN A
MOIST PLUME AS INDICATED BY RECENT WATER VAPOR IMAGERY. A SUBJECTIVE
UPPER AIR ANALYSIS REVEALED A DECENT RIDGE ALOFT WITH LOCAL HEIGHT
RISES...BUT A 40 TO 50KT JET JUST TO OUR NORTH...WHICH PLACES US
IN THE RIGHT ENTRANCE REGION AND WITHIN AN AREA OF ASCENT. THUS...
SPOTTY SHOWERS HAVE CONTINUED WITHIN THIS MOIST PLUME THROUGH THE DAY
WHICH HAS ALSO RESULTED IN A VERY NARROW BAND OF CLOUDS...WHICH
HAS HELD TEMPERATURES DOWN A BIT MORE THAN PREVIOUSLY THOUGHT.
THUS...WILL LIKELY BE ABLE TO TRIM SOME OF THE EXISTING HEAT
ADVISORY WITH THIS AFTERNOON. TO THE NORTH AND SOUTH OF THIS BAND...
SKIES HAVE REMAINED MOSTLY SUNNY...AND WE/VE EITHER MET OR SHOULD
MEET HEAT ADVISORY CRITERIA THROUGH EARLY EVENING.
MEANWHILE...THE ADVANCING COLD FRONT EXTENDED FROM CENTRAL SOUTH
DAKOTA THROUGH CENTRAL NEBRASKA...AND WILL BE MOVING INTO NORTHEAST
NEBRASKA THIS AFTERNOON. THIS WILL BE A FOCUS FOR THUNDERSTORMS THIS
EVENING IF THE CAP CAN BE BROKEN...ALTHOUGH SEVERE STORMS COVERAGE MAY
BE MARGINAL DUE TO RELATIVELY WEAK WIND SHEAR OF 25 TO 30
KTS...BUT STILL A SLIGHT RISK OF SEVERE STORMS WOULD BE POSSIBLE
THIS EVENING IN NORTHEAST NEBRASKA AND NORTHWEST IOWA. THE FRONT
CONTINUES TO MAKE SLOW PROGRESS SOUTHWARD THROUGH THE FORECAST
AREA OVERNIGHT AND MAY REACH NORTHEAST KANSAS AND NORTHWEST
MISSOURI BY DAYBREAK SUNDAY. WHILE I DONT BELIEVE WE/LL SEE
WIDESPREAD STORM COVERAGE OVERNIGHT...STILL SUFFICIENT FORCING
FOR 30 TO 40 PERCENT CHANCE OF RAIN.
DUE TO THAT MOISTURE PLUME THAT WILL PROBABLY REMAIN IN PLACE...
THERE COULD STILL BE SOME POST FRONTAL SPOTTY SHOWERS SUNDAY
MORNING...AND WITH BUILDING HEAT IN THE AFTERNOON...COULD SEE
ADDITIONAL THUNDERSTORMS REDEVELOP...PRIMARILY SOUTHERN FORECAST
AREA...THAT COULD ALSO LINGER INTO SUNDAY NIGHT. WE WILL EXPERIENCE
A NORTHEASTERLY FLOW DURING THIS TIME...WHICH WILL BRING IN SLIGHTLY
COOLER TEMPS...AND SLIGHTLY LESS HUMID AIR AS WELL TO SOME AREAS...AS
HIGH PRESSURE PREVAILS BEHIND THE COLD FRONT.
THE HIGH PRESSURE AXIS DOES BEGIN TO SHIFT EAST ON MONDAY. THE
QUESTION REMAINS...AS FLOW RETURNS TO THE SOUTHEAST...WHETHER WE
MIGHT BE ABLE TO CONTINUE TO POP A FEW SHOWERS WITHIN THE MOIST
PLUME...MAINLY THROUGH THE HEAT OF THE AFTERNOON. FOR MONDAY NIGHT
AND TUESDAY...THE RIDGE BEGINS TO REESTABLISH ITSELF ACROSS THE
PLAINS. LATEST MODELS SUGGEST THAT ANOTHER IMPULSE COULD BE
TOPPING THE RIDGE MOVING THROUGH THE DAKOTAS...WHICH CLOUD CLIP
NORTHERN PORTIONS OF THE FORECAST AREA.
.LONG TERM...WEDNESDAY THROUGH SATURDAY. THE RIDGE THAT WAS IN PLACE
ACROSS THE CENTRAL UNITED STATES SHOULD FLATTEN EARLY IN THE PERIOD
IN RESPONSE TO A WAVE MOVING THROUGH THE NORTHERN ROCKIES AND
EVENTUALLY NORTHERN PLAINS. THIS WILL PUSH A SLOW MOVING FRONT
TOWARD THE REGION FROM THE NORTH...BUT IN TYPICAL FASHION...THE
FRONT WILL LIKELY STALL NEAR OUR AREA RIGHT ON THROUGH THE PERIOD.
WITH A GENERALLY FLAT RIDGE AND A STALLED FRONTAL BOUNDARY REMAINING
ACROSS THE NEBRASKA AND IOWA VICINITY...IT APPEARS TO BE A SOMEWHAT
UNSETTLED WEATHER PERIOD ONCE AGAIN WITH NEARLY A DAILY CHANCE OF
SHOWERS AND THUNDERSTORMS AS NUMEROUS RIPPLES CONTINUE TO MOVE
THROUGH A FAST WESTERLY FLOW. THIS SHOULD HOWEVER LIMIT THE HEAT
JUST A BIT...WITH TEMPERATURES IN THE UPPER 80S TO LOWER 90S.
DEWALD
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
OVERALL VFR CONDITIONS EXPECTED THRU THE FCST PD. SCATTERED TSRA
EXPECTED THOUGH TO ACCOMPANY COLD FRONT DROPPING SWD THRU ERN NEB
LATER TONIGHT. AREAL COVERAGE OF CONVECTION IN QUESTION...SO HAVE
OPTED TO KEEP MVFR/PROB30 GROUPS BTWN 24/06-12Z AT ALL
TERMINALS.
DEE
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR NEZ011-012-015>018-
030>034-042>045-050>053-065>068-078-088>093.
IA...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR IAZ043-055-056-069-
079-080-090-091.
&&
$$