FXUS63 KOAX 090235
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
935 PM CDT FRI JUL 8 2011
.UPDATE...
ADJUSTED POPS OVERNIGHT AND INTO THE DAY ON SATURDAY.
&&
.DISCUSSION...
00Z SOUNDING DATA INDICATES THAT THE ATMOSPHERE OVER THE CWA IS
GENERALLY STABLE THIS EVENING...AND UPSTREAM LOW LEVEL AIR FROM
MO/ERN KS IS ALSO FAIRLY STABLE. THUS ONGOING THUNDERSTORM
ACTIVITY OVER WESTERN NEBRASKA WILL HAVE A TOUGH TIME MAKING IT
EAST INTO THE FA OVERNIGHT. HAVE BACKED OFF ON TIMING OF THE
INITIAL PRECIP MENTION TO AFTER 4 AM IN THE NORTHWEST CWA AND
REMOVED POPS ACROSS THE REST OF THE CWA OVERNIGHT. AS THE LOW
LEVEL JET VEERS IN THE MORNING...SOME ACTIVITY MAY LINGER PAST 12Z
OVER NORTHEAST NEB...AND THUS HAVE ADDED SOME MORNING POPS TO
THIS AREA. ALSO LOWERED CLOUDS THROUGH A GOOD PART OF THE NIGHT
BEFORE CONVECTIVE DEBRIS STARTS TO MOVE INTO THE WESTERN FA AFTER
MIDNIGHT. OTHER ELEMENTS OF THE FORECAST APPEAR ON TRACK ATTM.
NEW ZFP/GRIDS OUT BY 10 PM.
BOUSTEAD
&&
.PREV DISCUSSION... /ISSUED 303 PM CDT FRI JUL 8 2011/
SHORT TERM...TONIGHT THROUGH MONDAY.
MODELS IN PRETTY GOOD AGREEMENT THAT PCPN CHANCES TONIGHT FOCUSED
ALONG MID LYR AGEOSTROPHIC LIFT AXIS WEST OF THE CWA...AIDED BY MINOR
EMBEDDED IMPULSES PASSING THRU ALOFT. BNDRY LYR THETA-E AXIS BEGINS
TO SLOWLY SHIFT EAST OVERNIGHT AND SHOULD BE AT THE WRN CWA
PERIPHERY AFTER MIDNIGHT...THEN SLOWLY CROSS CWA SATURDAY. MAX
OMEGA AND BEST MOISTURE PER NAM/GFS GENERALLY CONCENTRATED OVER THE
NRN CWA JUST AHEAD OF COLD FRONT DROPPING OUT OF THE DAKOTAS. ON
SATURDAY...CAP WILL LIKELY BE A FACTOR UNTIL SAT AFTERNOON DAYTIME
HEATING ALLOWS DEVELOPMENT INVOF SFC TROF. FLOW ALOFT OVER THE
CNTRL PLAINS BECOMES ZONAL FOR A SHORT TIME RESULTING IN SFC BNDRY
BECOMING NEARLY STATIONARY. EXPECT PRESENCE OF SFC BNDRY INVOF THE
CWA WILL CONTINUE SATURDAY NIGHT THRU MONDAY...THUS WILL MAINTAIN
GOING POPS.
LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
OTHER THAN PULLING POPS ON WEDNESDAY...NO SIGNIFICANT CHANGES MADE.
FOCUS FOR PCPN MONDAY NIGHT THROUGH TUESDAY NIGHT REVOLVING AROUND
NEARLY STATIONARY SFC BNDRY ASSOCIATED WITH SFC LOW IN ERN MT. BNDRY
PROGGED TO EXTEND SEWD THRU NEB/NRN MO/OH VLY. MODELS EVENTUALLY
LIFT IT NORTH AS A WARM FRONT EARLY WEDNESDAY MORNING. IN THE
MEANTIME...GOOD MODEL AGREEMENT LARGE SCALE FLOW ALOFT WILL
TRANSITION TO UPPER LEVEL HIGH PRESSURE DOME BECOMING ESTABLISHED
OVER THE SERN STATES WITH A LONG WAVE TROF COVERING THE WRN CONUS.
GFS/ECM BOTH PLACE QPF OVER THE CWA WED NIGHT THRU FRIDAY TIME
FRAME...AND CURRENT FORECAST COVERS WITH SMALL POPS. NOT TOO
IMPRESSED THOUGH FOR ANY PCPN DEVELOPMENT DURING THAT TIME GIVEN
1000-500MB THKNS VALUES INCREASE TO GREATER THAN 579 DAM.
DEE
AVIATION...
TAF SITES KOFK/KOMA/KLNK
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH INCREASING HIGH
CLOUDS AS SURFACE HIGH PRESSURE SHIFTS EAST AND COLD FRONT MOVES
INTO THE NORTHERN HIGH PLAINS. SOME POTENTIAL FOR A THUNDERSTORM AT
KOFK AROUND 12Z BUT WILL LEAVE MENTION OUT FOR NOW AS STRONGER
DYNAMICS LOOK TO STAY TO THE NORTH.
FOBERT
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$