FXUS63 KOAX 182045
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
345 PM CDT WED MAY 18 2011
.DISCUSSION...
ACTIVE WEATHER PATTERN EXPECTED THROUGH THE MIDDLE OF NEXT WEEK.
BROAD TROUGH CENTERED OVER UTAH WILL VERY SLOWLY SHIFT EASTWARD
OVER THE NEXT FEW DAYS...FINALLY BECOMING CENTERED OVER CENTRAL
PLAINS BY FRIDAY AFTERNOON. MEANWHILE...SURFACE LOW PRESSURE OVER
THE SOUTHEASTERN PLAINS BECOMES MORE ORGANIZED AND DEEPENS OVER
WESTERN KANSAS TONIGHT. SCATTERED SHOWERS AND THUNDERSTORMS WILL
PERSIST MAINLY ACROSS EASTERN NEBRASKA THIS EVENING AS A STRONG
PUSH OF WARM AIR ADVECTION WORKS ACROSS THE AREA. SHOWERS AND
THUNDERSTORMS WILL BECOME WIDESPREAD BY LATE TONIGHT AS UPPER
LEVEL SUPPORT INCREASES LATE TONIGHT AND MUCH OF THURSDAY WITH A
80KT JET MAX TRACKING INTO THE REGION. ELEVATED THUNDERSTORMS
COULD CONTAIN MARGINALLY SEVERE HAIL ON THURSDAY AFTERNOON AND
EVENING...PARTICULARLY ACROSS SOUTHEAST NEBRASKA NEAR THE
APPROACHING JET MAX. WIDESPREAD PRECIPITATION WILL PERSIST INTO
THURSDAY NIGHT AND EARLY FRIDAY WITH A DEEPER POOL OF MOISTURE
SPELLING THE POTENTIAL FOR MODERATE/HEAVY RAINFALL AMOUNTS.
AGAIN...MARGINALLY SEVERE STORMS WILL BE POSSIBLE DURING THIS TIME
FRAME.
THE SLOW MOVING UPPER LOW TURNS NORTHWARD ON FRIDAY AND WOBBLES
INTO NORTH DAKOTA BY SATURDAY...THEN TOWARDS LAKE SUPERIOR ON
SUNDAY NIGHT. AS A RESULT SEVERAL WEAK WAVES ROTATING AROUND THE
PARENT LOW WILL KEEP THE AIRMASS VERY UNSTABLE AND ALLOW RAIN
CHANCES TO REMAIN IN THE FORECAST THROUGH AT LEAST THE WEEKEND.
DRY SLOTTING WILL BRING SOME BREAKS TO THE SHOWERS BUT OVERALL
PATTERN WILL BE WET THROUGH SATURDAY. TEMPERATURES WILL BE MILD
WITH HIGHS EXPECTED PRIMARILY IN THE 70S. RIDGING MAKES A BRIEF
RETURN ON MONDAY...BUT GUIDANCE SUGGESTS THAT ANOTHER BROAD TROUGH
WILL BRING ENCROACHING ON THE PLAINS AS EARLY AS TUESDAY.
&&
.AVIATION...
CONDITIONS WILL LIKELY REMAIN VFR FOR MUCH OF TONIGHT...BUT THEN
THINGS BEGIN TO CHANGE. A LARGE UPPER LOW TO THE WEST WILL SPIN OFF
SHORT WAVE ENERGY WHICH WILL LIKELY BEGIN TO AFFECT OUR SOUTHERN
ZONES SHORTLY BEFORE SUNRISE. THE QG FORCING IS ACTUALLY STRONGEST
IN WESTERN NE THURSDAY MORNING...BUT A LOBE OF IT WILL MOVE
NORTHWARD ACROSS OUR AREA. THEREFORE RAIN WILL BECOME INCREASINGLY
LIKELY MOVING FROM SOUTH TO NORTH LATE TONIGHT AND THURSDAY
MORNING...WITH MVFR CONDITIONS PREVAILING IN MUCH OF THE RAINFALL.
THERE IS ALSO A RISK THAT OUR SOUTHERN ZONES MAY EXPERIENCE SOME IFR
CEILINGS AS THURSDAY MORNING PROGRESSES. THE BEST CHANCES FOR A FEW
THUNDERSTORMS TO EMBED WITH THE RAINFALL WILL BE FROM ABOUT A
COLUMBUS TO OMAHA LINE AND SOUTHWARD THURSDAY MORNING. NORTH OF THAT
LINE...THUNDERSTORM CHANCES BECOME INCREASINGLY MORE DIFFICULT DUE
TO STABILITY...BUT AGAIN RAINFALL IS CERTAINLY A THREAT IN OUR
NORTHERN ZONES.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
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