FXUS63 KOAX 230914
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
414 AM CDT THU SEP 23 2010
.DISCUSSION...
FORECAST CONCERNS TODAY WILL BE POTENTIAL FOR HEAVY RAIN...
STRONG WINDS AND HEADLINES.
WEDNESDAY WE HAD SEVERE WEATHER AND LOCALLY HEAVY RAIN IN
NORTHEAST NEBRASKA WITH 1.25 TO 1.5 INCH HAIL IN KNOX AND CEDAR
COUNTIES AND 4.25 INCHES OF RAIN AT CROFTEN. THE WARM FRONT THAT
LIFTED NORTH IS NORTH OF ONL...BUT SOUTH OF SPW IN NORTHWEST WITH
THE H85 BOUNDARY JUST TO THE NORTH OF THE SFC FNT. THE 00Z UPR AIR
DATA HAD THE H5 TROF FM MT TO SRN CA. A PLUME OF DEEP TROPICAL
MOISTURE STRETCHED FM MEXICO ACRS NM/CO/WRN KS/NE INTO SRN MN. THE
H7 DEWPOINT AT LBF WAS 9C...INDICATIVE OF THE DEEP MOISTURE.
THIS MORNING TEMPERATURES ARE QUITE MILD...IN THE MID AND UPR 70S
AT MANY LOCATIONS. OVER THE NEXT 12HRS...AM EXPECTING SFC LOW PRES
OVR NORTHEAST CO TO DEEPEN AND LIFT NORTHEAST TO SOUTHEAST
COLORADO AS THE MID LEVEL TROF MOVES INTO THE WRN PLAINS. PRECIP
WATER IS PROGGED TO BE OVER 2 INCHES TODAY. LARGE SCALE LIFT AND
ABUNDANT RH ALONG WITH A 4KM WRM CLD DEPTH WILL RESULT IN
EFFICIENT RAIN PRODUCTION AND WIDESPREAD RAIN TODAY. THE DIFFICULT
PART IS PINNING DOWN LOCATIONS THAT WILL SEE THE HEAVY RAIN. THE
INITIAL FOCUS OF HEAVY RAIN IS THE WARM FRONT. THIS AREA IS NORTH
OF OUR FORECAST AREA. THE SECOND AREA FOR HEAVY RAIN IS AHEAD OF
AND ALONG THE SFC LOW AND THE COLD FRONT. THIS AREA INCLUDES
NORTHEAST NEB/WCNTRL IA AND ECNTRL NEB AND THE REST OF THE FCST
AREA THIS AFTERNOON AND THIS EVENING. OVER THE LAST WEEK THERE
HAVE BEEN PERIODS OF RAIN...SOME HEAVY OVER THE FCST AREA. COUNTY
FFG IS 2 INCHES OR LESS FOR MOST OF OUR CWA AND LESS THAN 1.5
INCHES FOR SEVERAL COUNTIES. THIS STORM SYSTEM IS CAPABLE OF
PRODUCING AREAS OF 1 TO 2 INCH RAINS AND LOCAL 2 TO 4 INCH RAINS.
WITH THIS IN MIND ISSUED A FLASH FLOOD WATCH FOR THE NORTHERN AND
CENTRAL PARTS OF THE CWA THROUGH 4PM AND MUCH OF THE SRN CWA FROM
NOON UNTIL 10PM.
THE WINDS ARE THE NEXT CONCERN. AS THE SFC LOW DEEPENS THIS
MORNING AND EARLY THIS AFTERNOON THE SFC WINDS STRENGTHEN AND THE
H85 JET...ALREADY STRONG AT 50KTS INCREASES TO 60 OR 65KTS. THE
ONLY THING HOLDING ME BACK FM ISSUING A WIND ADVISORY IS THAT WE
WILL BE CLOUDY WITH RAIN AND THIS WILL HINDER THE MIXING. HAVE
STRONG WINDS FCST WITH 20 TO 25KTS SUSTAINED...WHICH IS JUST BELOW
WIND ADVISORY CRITERIA. THE DAYSHIFT CAN MONITOR HOW THINGS ARE
GOING AS THE STRONGEST WINDS ARE EXPECTED FOR LATE THIS MORNING
AND EARLY THIS AFTERNOON. THE RAIN MOVING IN WILL KEEP
TEMPERATURES IN CHECK. HIGHS MOSTLY IN THE 70S WITH LOWER 80S FOR
SOUTHEAST NEB AND SOUTHWEST IOWA.
THE FORECAST AREA HAS A RISK FOR SEVERE WEATHER AND WILL BE
CONDITIONAL ON THE INSTABILITY. THE SHEAR IS QUITE STRONG
TODAY...HOWEVER...THE CLOUDS AND RAIN WILL LIMIT INSTABILITY.
THERE IS A HINT AT AN INCREASE IN THE INSTABILITY ALONG THE FRONT
LATE THIS MORNING INTO THIS AFTERNOON...THUS WILL CONTINUE TO
MENTION THE RISK FOR SEVERE.
THE RAIN WILL BE MOVING OUT THIS EVENING OVER THE SOUTHEAST PART
OF THE FCST AREA WITH MUCH DRIER DEWPOINTS IN THE 40S TONIGHT.
WINDS SHOULD DIMINISH AS SFC HIGH PRES BUILDS IN WITH LOWS IN THE
UPR 40S TO LOWER 50S. FRIDAY STILL LOOKS DRY AND SUNNY WITH HIGHS
IN THE 70S.
THE WEEKEND STORM SYSTEM IS STILL ON TRACK FOR EARLY SATURDAY INTO
SATURDAY EVENING. HAVE POPS IN THE NORTH LATE FRIDAY NIGHT AND
CONTINUE ACRS THE FCST AREA SATURDAY AS THE MID LEVEL TROF OVR
MN/WI SWINGS THRU. WITH GOOD MODEL AGREEMENT...HIGH CHC TO LIKELY
POPS WITH THIS FEATURE SAT...DECREASING SATURDAY NIGHT. THE LOW
CLOSES OFF OVR IA/MO...AND ISO PRECIP MAY LINGER ALONG WITH SOME
CLDS. THIS WILL MAKE TEMPS TOUGH OVER THE WEEKEND AND CURRENTLY
HAVE HIGHS ONLY IN THE 60S AND 70S.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
WIDESPREAD MVFR CONDITIONS ARE EXPECTED TO DEVELOP BETWEEN 12Z AND
18Z AS THUNDERSTORMS INCREASE IN COVERAGE ACROSS EASTERN NEBRASKA
AHEAD OF A COLD FRONT MOVING EAST. CIGS SHOULD DROP TO NEAR FL025
WITH VSBYS NEAR 5SM AS SHOWERS INCREASE...BUT OCCASIONAL IFR
CONDITIONS IN THUNDERSTORMS ARE LIKELY. STRONG SOUTHERLY LOW LEVEL
JET WILL CAUSE LOW LEVEL WIND SHEAR THROUGH 14Z...THEN SURFACE WINDS
GUSTING NEAR OR ABOVE 30KTS CAN BE EXPECTED. THE COLD FRONT SHOULD
REACH KOFK NEAR 22Z...THEN KOMA AND KLNK NEAR 00Z. WINDS WILL TURN
TO THE NORTHWEST AND THUNDERSTORMS END WITH FRONTAL PASSAGE...
HOWEVER MVFR CIGS WILL REMAIN.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR NEZ011-012-015>018-
030>034-042>045-050>052.
FLASH FLOOD WATCH FROM NOON CDT TODAY THROUGH THIS EVENING FOR
NEZ053-066>068-089>093.
IA...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR IAZ043-055-056.
FLASH FLOOD WATCH FROM NOON CDT TODAY THROUGH THIS EVENING FOR
IAZ069-079-080-090-091.
&&
$$
ZAPOTOCNY/DERGAN