FXUS63 KOAX 090804
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
304 AM CDT SAT JUL 9 2011
.DISCUSSION...
WITH UPPER RIDGE OVER SERN U.S. KEEPING H5 HEIGHTS OVER ERN
NEBR/WRN IA ON HIGH SIDE INTO NEXT WEEK AND ILL-DEFINED/TIMED WEAK
DISTURBANCES ROTATING AROUND RIDGE UPPER FORCING FOR CONVECTION
WILL BE MEAGER OR HARD TO TIME MUCH OF FORECAST PERIOD. ONLY
CONSISTENT TREND HAS BEEN FOR PRECIPITABLE WATER VALUES...PWS...
TO GET TO AROUND 2 INCHES TODAY AND PERIODICALLY REMAIN THERE INTO
NEXT WEEK AND FOR SOME TYPE OF SUBTROPICAL/TROPICAL WAVE PIVOTING
FM W TX ACROSS CNTRL PLAINS IN TUE/WED PD.
THAT SAID THERE SHOULD BE PROBABLE PERIODS OF PRECIPITATION FIRST
OF WHICH COULD DEVELOP LATE THIS AFTN/EVENING VICINITY WEAK
BOUNDARY FM NCNTRL NEBR INTO SD. THIS ACTIVITY SHOULD TRACK ACROSS
NERN ZONES TONIGHT AND WARRANTS FIRST LIKELY PCPN GROUP. CAPPING
ISSUES COULD LIMIT SRN EXTENT OF PRECIP TONIGHT...BUT WITH SFC
TEMPS APPROACHING 100 IN CNTRL KS COULD SEE A MCS DEVELOP AND
TRACK ACROSS SERN ZONES...SO UPPED POPS MOST AREAS TONIGHT.
ALTHOUGH CONVECTION TONIGHT WILL PROBABLY MESS UP ALREADY WEAK
SURFACE FIELD ACROSS FORECAST AREA...MAIN FRONT WILL REMAIN TO
OUR NW UNTIL UPPER TROUGH CURRENTLY OVER ALBERTA CANADA BEGINS
OPENING UP AND PROGRESSING SEWD LATE SUNDAY INTO MONDAY. EVEN THEN
FRONT WILL BE LOSING ITS PUSH AS IT MOVES INTO UPPER RIDGE.
HOWEVER...BLEND OF 00Z GFS/ECMWF WOULD BRING THIS WEAK E-W
BOUNDARY TO NEAR OMAHA BY 12Z MONDAY. FELT A SECOND LIKELY POP WAS
WARRANTED NORTH OF IT SUNDAY NIGHT. QPF FROM 00Z NAM AND ECMWF
MEAGER AT BEST FOR FORECAST AREA AND PROBABLY A FUNCTION OF HIGH
HGTS/THICKNESSES FCST AND LACK OF SHORTWV ENERGY. HOWEVER...WITH
HIGH PWS...POSSIBLE TRAINING/SLOW MOTION TO CONVECTION AND BEEFED
UP LINGERING CAPE AVAILABLE DUE TO STRONG HEATING SUNDAY...IF MCS
DOES DEVELOP QPF AMOUNTS WILL BE QUITE A BIT HIGHER THAN THE
GENERALLY LESS THAN 1/2 INCH FORECAST. AMOUNTS WERE KEPT ON LOWER
SIDE WITH THIS FORECAST TO ACCOUNT FOR POSSIBILITY OF HIGH
HGTS/LACK OF UPPER SUPPORT SUPPRESSING ACTIVITY.
ALTHOUGH OVERALL LITTLE CHANGES WERE MADE TO TEMPERATURES THROUGH
FORECAST...MAX TEMPS WERE RAISED A LITTLE ACROSS SOUTHERN SECTIONS
MONDAY AS NAM/ECMWF KEPT FRONT NEARLY STATIONARY NEAR OMAHA. THIS
INCREASED HEATING AND WEAK SURFACE CONVERGENCE COULD WARRANT
ANOTHER LIKELY POP SCENARIO IN LATER FORECAST EITHER LATE MON AFTN
OR MON NIGHT...ALTHOUGH WITH THIS FORECAST POPS WERE RAISED IN MONDAY
NIGHT PERIOD THEY WERE KEPT IN CHANCE RANGE.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
VFR CONDITIONS ARE EXPECTED THRU THE TAF PD WITH SOUTHERLY SFC
WINDS. SCATTERED CU WL LIKELY DEVELOP BY 17Z JUST AS MID AND HIGH
CLOUDS MOVE OUT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
CHERMOK/KERN