FXUS63 KOAX 200904
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
404 AM CDT MON SEP 20 2010
.DISCUSSION...
SEVERAL FORECAST CONCERNS THIS PACKAGE AS WE ARE STARTING OUT WITH
WIDESPREAD DENSE FOG...THEN HAVE CLEARING...WARMER AND WINDY
CONDITIONS THIS AFTERNOON. SEVERAL FRONTS WILL AFFECT THE FORECAST
AREA THRU WED.
THE OAX 00Z SOUNDING HAD A DEPTH OF SATURATION AROUND 3K FT.
LATEST SFC OBS SHOW WIDESPREAD VSBYS AOB 1 MILE SOUT OF WAYNE WITH
A QUARTER OF A MILE FM YORK TO NEB CITY. IN ADDITION TO THE FOG
THERE IS SOME DRIZZLE. HAVE A DENSE FOG ADVISORY FOR THE SRN
2/3RDS OF THE FORECAST AREA AND CONTINUE THIS THRU 8AM. THE LOW
CLOUDS ARE BEGINNING TO BUDGE NEAR HOLDREGE AS THE LOW LEVEL JET
INCREASES AND THE SFC WINDS RESPOND AND ERODE THE LOW LEVEL RH.
TRENDED CLEARING FROM 12Z-16Z FM SOUTH TO NORTH.
THE LATEST VWP ARE SHOWING 50KTS ACRS NEB AT H85. AS THE MORNING
PROGRESSES...THESE STRONG WINDS ALOFT WILL MIX DOWN TO THE SFC
WITH SUSTAINED WINDS IN EXCESS OF 25KTS. DUE TO THE INCREASING
WINDS THRU THE LAYER WITH SUNSHINE AND UNI-DIRECTIONAL WINDS FM
THE SFC TO H85 AND HIGHER...HAVE DECIDED TO ISSUE A WIND ADVISORY
FM 17Z-00Z TODAY FOR MUCH OF EASTERN NEB INTO WRN IA MAINLY ALONG
AND NORTH OF A LINE FROM BIE TO OMAHA TO MO VALLEY. THE DAYSHIFT
CAN SEE HOW THIS IS GOING AS FAR AS POTENTIALLY ADJUSTING
SOUTHWARD ETC. MEANWHILE...AFTER TWO DAYS OF WELL BELOW NORMAL
TEMPERATURES...WITH THE WARM FRONT LIFTING NORTH...HAVE WELL
ABOVE NORMAL TEMPERATURES WITH HIGHS MOSTLY NEAR 90. CURRENT
RECORDS ARE 93 AT OMA/95 LNK/100 AT OFK...SO ARE WITHIN A CATEGORY
OF THE RECORDS AT OMA AND LNK.
THE MID LEVEL RIDGE OVER THE CENTRAL PART OF THE COUNTRY BEGINS TO
BREAK DOWN AS A MID LEVEL TROF MOVES INTO THE NRN PLAINS TODAY. IN
RESPONSE TO THE TROF...LOW PRES DEEPENS OVER WESTERN SOUTH DAKOTA
WITH A STRONG PRES GRADIENT OVR NEB. DURING THE AFTERNOON...A SFC
COLD FRONT WILL MOVE INTO WESTERN NEBRASKA. TONIGHT...THE
COMBINATION OF THE UPR LEVEL SUPPORT AND THE COLD FRONT SHIFTING
INTO NORTHEAST NEBRASKA AND THEN EAST CENTRAL NEBRASKA SHOULD
TRIGGER A FEW SHOWERS AND THUNDERSTORMS. THRU TONIGHT THE CAPE IS
GENERALLY LESS THAN 1000J/KG...HOWEVER SOME STRONGER DEEP LAYER
SHEAR DOES MOVE IN AFTER MIDNIGHT. THE SFC FRONT STALLS OUT OVER
THE AREA TUES AS THE MID LEVEL FLOW FLATTENS OUT. THE FRONT THEN
LIFTS BACK NORTHWARD WED. SHRA/TSRA WILL BE POSSIBLE IN THE
VICINITY OF THE FNT. A STRONGER SHORTWAVE TROF MOVES INTO THE
PLAINS WED NIGHT AND THUR. THE STORMS TUES AND WED SHOULD HAVE SOME
BETTER INSTABILITY TO WORK WITH ALONG WITH MODERATE
SHEAR...INCREASING IN THE NORTH. DEEPER RH SHOULD ALSO INCREASE
FOR WED AND THU.
DID NOT MAKE ANY CHANGES BEYOND WED NIGHT...BUT WILL NEED TO LOOK AT
INCREASING POPS THURSDAY WITH THAT STRONGER WAVE. FRIDAY IS STILL
LOOKING DRY AND ISO PRECIP FOR SAT.
&&
.AVIATION...
06Z TAFS
LIFR CONDITIONS ARE EXPECTED AT ALL TAF SITES EARLY THIS MORNING
WITH FOG AND SOME PATCHY DRIZZLE. LLWS IS ALSO EXPECTED AT ALL TAF
SITES WITH A STRONG LLJ OF 45-50KTS REMAINS JUST OVERHEAD. LIFE
CONDITIONS SHOULD SCATTER OUT THIS MORNING FROM SOUTH TO
NORTH...EXPECTING VFR CONDITIONS AT KLNK BY 15-17Z ACROSS THE AREA.
FOCUS SHIFTS TO DEVELOPING SOUTHERLY WINDS...INCREASING TO 24-26KTS
SUSTAINED...WITH GUSTS UP TO 31-34KTS...THAT SHOULD LINGER THROUGH
ABOUT 01Z. THEREAFTER...THERE WILL BE CHANCE FOR THUNDERSTORMS AT
KOFK BY 06Z...AND 09-12Z AT KLNK/KOMA...AND MAY CONSIDER ADDING SOME
PROB30 GROUPS IN THE NEXT TAF ISSUANCE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 8 AM CDT THIS MORNING FOR NEZ030-
042>045-050>053-065>068-078-088>093.
WIND ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
NEZ011-012-015>018-030>034-042>045-050>053-065-066-078-088-
089.
IA...DENSE FOG ADVISORY UNTIL 8 AM CDT THIS MORNING FOR IAZ055-056-
069-079-080-090-091.
WIND ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
IAZ043-055.
&&
$$
ZAPOTOCNY/DEWALD