996
FXUS63 KOAX 161730
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1230 PM CDT WED OCT 16 2013
.AVIATION...18Z TAFS FOR KOFK...KLNK AND KOMA.
VFR WILL PREVAIL AT ALL THREE TAF SITES THROUGH THE FORECAST
PERIOD. AS THE UPPER LEVEL WAVE EXITS THE REGION TO THE
EAST...UPPER RIDGING WILL BUILD ACROSS THE WESTERN HIGH PLAINS AND
INTO THE CENTRAL PLAINS. THIS WILL KEEP THE WEATHER QUIET AND COOL
THROUGH THIS FORECAST PERIOD.
&&
PREV DISCUSSION... /ISSUED 311 AM CDT WED OCT 16 2013/
SHORT TERM...(THIS AFTERNOON THROUGH FRIDAY)
MAIN FORECAST PROBLEMS ARE CLOUD COVER AND INFLUENCES ON
TEMPERATURES...AS WELL AS SMALL RAIN CHANCES MAINLY FRIDAY.
THE FORECAST AREA WILL REMAIN UNDER THE INFLUENCE OF A BROAD
LONGWAVE UPPER TROUGH THAT COVERED MUCH OF THE WESTERN TWO-THIRDS
OF THE UNITED STATES EARLY THIS MORNING. THIS PUTS THE REGION
UNDER CYCLONICALLY CURVED UPPER FLOW THAT WILL PERSIST INTO NEXT
WEEK. THIS PATTERN TYPICALLY INCLUDES A SERIES OF WEAK SHORTWAVES
AND ASSOCIATED COLD FRONTS... WITH ABOVE NORMAL CLOUD COVER AND
BELOW NORMAL TEMPERATURES. 00Z MODEL SUITE ADVERTISES JUST THAT...
WITH MINOR VARIANCES IN TIMING OF FRONTAL PASSAGES.
INITIALLY...THE STRATO-CU FIELD CURRENTLY OVER EASTERN AND
NORTHERN NEBRASKA...AS WELL AS ALL OF IOWA...IS LINGERING LONGER
THAN PREDICTED BY EARLIER MODEL RUNS. GENERALLY SEEMS TO BE A BIAS
OF MOVING STRATUS OUT TOO QUICKLY IN THESE SCENARIOS...THUS WE
HAVE FAVORED A SLOWER DECREASING OF THE CLOUDS TODAY. KNOCKED
FORECAST HIGHS DOWN A DEGREE OR TWO AS A RESULT. EVEN TONIGHT
THERE COULD BE THIN POCKETS OF CLOUD COVER TO KEEP LOWS FROM
DROPPING MUCH BELOW THE MID 30S.
THE NEXT WAVE/FRONT SHOULD ENTER THE REGION THURSDAY. EXPECT A
PRE- FRONTAL SURFACE TROUGH TO MOVE THROUGH THE FORECAST AREA
THURSDAY MORNING WITH THE INITIAL WIND SHIFT TO THE NORTHWEST.
ACTUAL COLD FRONT SHOULD ENTER NORTHEAST NEBRASKA THURSDAY
AFTERNOON THEN EXIT SOUTHWEST IOWA THURSDAY EVENING. MODELS ARE
DRY WITH THIS WAVE AND THIS LOOKS REASONABLE GIVEN THE DRY
PROFILE. ANOTHER SURGE OF CLOUDS AND SLIGHTLY COOLER AIR ARE
EXPECTED BEHIND THE FRONT.
CONFIDENCE IS LOW WITH THE FORECAST FOR FRIDAY. SURFACE HIGH
PRESSURE BUILDS INTO THE REGION EARLY...THEN ANOTHER WAVE/FRONT
MOVES IN LATE FRIDAY. MODELS ARE SHOWING A STRONGER SHORTWAVE
MOVING OVER THE TOP OF THE SURFACE HIGH PRESSURE DOME...WITH
TIGHTENING BAROCLINIC ZONE OVER KANSAS AROUND 850MB AND
ASSOCIATED STRONG FRONTOGENESIS IN THE 850-700MB LAYER. THIS MAY
PROVIDE ENOUGH FORCING TO GENERATE SHOWERS IN OUR SOUTHERN
COUNTIES...BUT DRY AIR NEAR THE SURFACE WILL HINDER RAIN FOR A FEW
HOURS. SETTLED ON A SLIGHT CHANCE FOR LIGHT SHOWERS SOUTH FRIDAY.
HIGHS EXPECTED TO BE IN THE 50S FRIDAY AFTER MORNING LOWS IN THE
MID 30S NORTH TO 40 SOUTH.
LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ABOVE MENTIONED UPPER PATTERN CONTINUES INTO TUESDAY WITH WEAK
SHORTWAVES AND FAST MOVING SURFACE COLD FRONTAL PASSAGES. AT THIS
TIME THERE IS NOT ENOUGH SUPPORT IN ANY PERIOD FOR PRECIPITATION
CHANCES...AND TEMPERATURES SHOULD GENERALLY REMAIN SLIGHTLY COOLER
THAN NORMAL.
NIETFELD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
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