FXUS63 KOAX 280925
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
325 AM CST FRI JAN 28 2011
.DISCUSSION...
SYNOPSIS...00Z UPPR AIR ANLYS INDCD UPPR LVL RIDGE FM THE GREAT
BASIN TO THE ERN PAC. SHRTWV TROF ANALYZED OVR BRITISH COLUMBIA
WAS ASSOCIATED WITH A 140 KT H3 JET AND H5 HEIGHT FALLS OF AROUND
80 M. DOWNSTREAM OF THE SHRTWV TROF...HEIGHTS HAVE BEEN INCREASING
OVR THE PLAINS AT H5. H85 ANALYSIS INDCD LO PRES OVR NRN SASK WITH
A WRM FNT SWD THRU THE WRN HI PLAINS. 08Z SFC ANLYS INDCD WRM FNT
EXTNDD FM CNTRL ND INTO NW KS.
FORECAST...MAIN FORECAST ISSUE FOR THE SHRT TERM IS HOW WARM TMPS
WL GET TODAY...AND THEN THE COOL DOWN INTO THE WEEKEND. 00Z KOAX
SOUNDING INDC A 950 MB TMP +2F 0C AND A 925 MB TMP OF 0 C. THIS IS
PROGGED BY MODELS TO WARM TODAY...AND WITH THE EXPECTED SUN...SEE
NO REASON WE WILL BE COOLER THAN THE TMPS ON THU. GOING FORECAST
INDCD THIS...AND HAD ABOUT A 1 TO 2 F INCREASE THAN WHAT WAS SEEN
ON THU AND THIS SEEMED ON TRACK. WRM FNT MAY TEND TO STALL NEAR
THE RIVER LATER THIS MRNG...AND THUS WE WILL NEED TO MONITOR SW
IA AS THEY MAY BE A TOUCH COOLER. WE HAVE SLOWED THE WARM UP IN
THE GRIDS IN THOSE LOCATIONS. AS THE BC SHRTWV TROF CROSSES THE
NRN PLAINS LATER TODAY...CDFNT EXPECTED TO SWEEP THRU THE FA. HAVE
INCREASED GOING LOWS A TOUCH TONIGHT AS MOS HAS SLOWED SOME OF THE
COOLING...AND THIS SEEMED REASONABLE GIVEN THE RAW FIELDS. THE
FIRST IN A SERIES OF SHRTWV TROFS WILL CROSS THE REGION ON SAT
BEHIND THE SFC CDFNT WITH A QUICK MOVG AREA OF DPVA FM SD INTO
IA. THIS IS EXPECTED TO RIDE ALNG THE MID LVL THRML GRADIENT WITH
FRONTOGENESIS INDCD ARND H6-H7 FM THE EC/GFS/NAM. ALTHOUGH MODELS
ARE FAIRLY DRY QPF WISE...STABILITY IS NOT ALL THAT GREAT AND
GIVING THE FORCING...MAINTAIN THE SCHC POPS IN THE N ON SAT AFTN
FOR A QUICK SHOT OF -SN. LITTLE IN THE WAY OF ACCUM WLD BE
EXPECTED THOUGH.
THE NEXT SHRTWV TROF FOR THE FA IS EXPECTED ON LATE SUN INTO EARLY
MON. AGAIN THE MODELS ARE IN GOOD AGREEMENT IN THE TRACK OF A
MINOR SHRTWV TROF ALNG THE MID-LVL W-E THERMAL GRADIENT DURING
THIS TIME LEADING TO A QUICK SHOT OF FRONTOGENESIS AND LIFT. THE
MAIN QUESTION THOUGH IS THE LATITUDE THE SYSTEM PASSES. THE EC/GEM
ARE N OF OUR FA WHILE THE GFS/NAM IMPACT OUR NRN CWA. GIVEN THE
UNCERTAINTY LEFT HIGH CHC POPS GOING. WHERE EVER THE FRONTAL BAND
ENDS UP...IT LOOKS LIKE SOME MINOR 1-2 IN ACCUM WILL BE POSSIBLE
WITH THIS SYSTEM. IN ADDITION...THE COLD AIR IS EXPECTED TO CONT
TO SLOWLY PUSH SWD THRU THE WEEKEND WITH HIGHS/LOWS A LITTLE
COOLER EACH DAY. GOING FORECAST HAS THIS HANDLED WELL AND WE MADE
VERY FEW CHANGES.
THE EXTENDED PART OF THE FORECAST GETS A LITTLE MORE INTERESTING
AS THE EC HAS A MADE A LARGE JUMP IN CONTINUITY...AND NOW HAS A
MAJOR WINTER STORM FOR THE FA ON TUE/WED. THIS OCCURS AS NRN
STREAM SHRTWV PHASES WITH THE SRN STREAM SYSTEM EXPECTED TO MOV
INTO THE GREAT BASIN FM THE ERN PAC ON SUN. THE GEM ALSO INDCS A
SIG SYSTEM MOVG THRU THE PLAINS...BUT IS GENERALLY S OF THE FA.
QUICK ANALYSIS OF THE GFS ENSEMBLES SHOW LITTLE SUPPORT FOR SUCH
A SIG SYSTEM AS THE EC AT THIS TIME...BUT MODELS ALWAYS HAVE A
DIFFICULT TIME WITH PHASING...SO NO SOLUTION SEEMS OUT OF THE
REALM OF POSSIBILITY ATTM. NAEFS MEAN WLD INDC THE BEST CHC FOR
PRECIP WITH THIS SYSTEM WLD BE IN THE TUE/TUE NIGHT TIME FRAME AND
THUS WL INSERT SOME CHC POPS INTO THAT TIME FRAME AS A STARTING
POINT. OTHERWISE WILL JUST NEED TO WAIT FOR MORE CONTINUITY...BUT
EXPECT MORE MODEL CHANGES AS THE SYSTEM NEARS DUE TO THE
COMPLEXITY.
BOUSTEAD
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
INTERMITTENT FOG IS POSSIBLE AT ALL TAF SITES THROUGH AROUND 16Z
THIS MORNING...WITH VIS VARYING BETWEEN VFR AND LIFR AS PATCHY FOG
DEVELOPS. ONCE FOG CLEARS...VFR CONDITIONS ARE EXPECTED AT ALL
SITES...WITH LIGHT WRLY WINDS THROUGH AROUND 00Z BEFORE WINDS BECOME
NWRLY AND INCREASE TO AROUND 10-12KT.
MAYES
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$