FXUS64 KAMA 292358 AAA
AFDAMA
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE AMARILLO TX
558 PM CST SUN NOV 29 2009
.AVIATION...
WINTRY MIX HAS MOVED EAST OF THE AMA AND DHT THIS EVENING...WITH
IMPROVING CONDITIONS ALL READY OCCURRING. REMOVED ALL MENTION OF
PRECIP AND LOW CLOUDS FROM THE TAFS FOR THE 00Z ISSUANCE. SKIES
SHOULD BEGIN TO CLEAR AS SURFACE HIGH SETTLES INTO THE REGION. VFR
FORECAST THE 24 HOURS.
TAB
&&
.PREV DISCUSSION... /ISSUED 342 PM CST SUN NOV 29 2009/
DISCUSSION...
MAIN FORECAST CONCERNS THIS AFTERNOON CENTER ON PRECIP POTENTIAL
ASSOCIATED WITH UPPER LOW NEAR THE FOUR CORNERS REGION AND ON TEMPS
THROUGHOUT THE WEEK.
WATER VAPOR IMAGERY INDICATES STRONG CLOSED UPPER LOW OVER SOUTHERN
AZ. MODEL GUIDANCE HAS BEEN CONSISTENT IN DIGGING THIS LOW FURTHER
SOUTH BEFORE IT LIFTS ACROSS SOUTHERN NM MONDAY. PROFILER NETWORK
INDICATES A JET STREAK LIFTING ACROSS THE SOUTHERN PLAINS AND
COMBINED WITH MID LEVEL FRONTOGENETICAL FORCING HAS HELPED TO SUSTAIN
SNOW ACROSS THE SOUTHERN PANHANDLES. AFTERNOON REFLECTIVITY DOPPLER
RADAR IMAGERY SHOWS ANOTHER AREA OF PRECIP LIFTING NORTHEAST OUT OF
THE SOUTHERN ROLLING PLAINS. GIVEN CURRENT TRAJECTORY OF THIS BAND
OF PRECIP...HAVE INCREASED POPS THIS EVENING IN THE SOUTHEAST
PORTION OF THE TX PANHANDLE. PRECIP TYPE HAS BEEN MAINLY ALL SNOW
TODAY AS 12Z AMA RAOB SOUNDING SHOWS A WEDGE OF WARM DRY AIR IN THE
MID LEVELS WITH A SATURATED LAYER ALOFT WHICH WOULD PROMOTE
EVAPORATIVE COOLING. HOWEVER CAN SEE A RAIN SNOW MIX IN THE
SOUTHEAST TX PANHANDLE AS TEMPS REMAIN JUST ABOVE FREEZING THIS
EVENING. EXPECT PRECIP TO SHUT OFF LATER THIS EVENING AS FORCING FOR
ASCENT DIMINISHES. SFC ANTICYCLONE BUILDS INTO THE CENTRAL PLAINS
TONIGHT WHICH WILL CAUSE SKIES TO START TO CLEAR AND WINDS TO
DIMINISH. AS DRIER AIR UPSTREAM MOVES IN ON NORTHERLY WINDS...
SHOULD SEE A COLDER NIGHT. HAVE LEANED TOWARD THE COOLER MET
GUIDANCE WITH LOWS RANGING FROM THE UPPER TEENS OUT WEST TO THE
UPPER 20S IN THE SOUTHEAST.
MONDAY LOOKS TO BE THE WARMEST DAY OF THE WEEK AS THE SFC
ANTICYCLONE SLIDES INTO EASTERN TX...RESULTING IN A LIGHT WEST TO
SOUTHWEST LOW LEVEL FLOW. WITH DOWNSLOPING WINDS AND RISING
HEIGHTS...HIGHS IN THE 50S LOOK REASONABLE. UPPER LOW HEADS
TOWARD WEST TX LATE MONDAY NIGHT. SHOULD SEE CLOUDS
THICKEN/INCREASE ACROSS THE SOUTHERN TX PANHANDLE. AFTER SEEING
SOME RECOVERY IN TEMPS MONDAY AND WITH THE INCREASE IN CLOUDS...
LOWS MONDAY NIGHT WILL BE WARMER....WITH TEMPS IN THE UPPER 20S TO
MID 30S.
MODEL GUIDANCE CONTINUES TO SHOW CONSISTENCY IN THE TRACK OF
THE UPPER LOW BUT SOME TIMING DIFFERENCES SHOW UP WITH THE VARIOUS
MODEL SOLUTIONS. THE GFS HAS THE QUICKEST SOLUTION AND WITH HPC
PREFERRING A NON GFS BLEND...HAVE TRENDED FORECAST TOWARD A BLEND OF
THE NAM/ECMWF. AS THE LOW SLIDES ACROSS SOUTHERN TX...DEFORMATION
AXIS WILL MOVE ACROSS THE SOUTHERN TX PANHANDLE. MEANWHILE A
NORTHERN BRANCH TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS. THIS
WILL BRING A REINFORCING SHOT OF COLDER AIR TO THE AREA. MODEL
SOUNDINGS OFF THE NAM INDICATE A DEEP SATURATED LAYER WITH MOST OF
THE COLUMN BELOW FREEZING...WHICH WOULD SUPPORT ALL SNOW. SHOULD SEE
TEMPS CLIMB ABOVE FREEZING DURING THE AFTERNOON THOUGH SO WENT WITH
A RAIN SNOW MIX. COLD FRONT WILL PUSH INTO THE AREA WEDNESDAY...
KEEPING TEMPS ON THE COOL SIDE. PRECIP SHOULD END WEDNESDAY AS THE
UPPER LOW SLIDES INTO EAST TX. SNOWFALL TOTALS CAN RANGE FROM 1 TO 2
INCHES WHICH IS WITHIN ADVISORY CRITERIA. HOWEVER HELD OFF ON
ISSUING ANY HEADLINES AS ANY DEVIATION IN THE TRACK OF THE UPPER LOW
CAN GREATLY AFFECT SNOWFALL AMOUNTS.
UPPER LOW GETS CAUGHT UP IN THE NORTHERN BRANCH AND EJECTS TO THE
EASTERN CONUS THURSDAY...LEAVING THE AREA IN DRY NORTHWEST FLOW
ALOFT. CAN SEE SOME MODERATION IN TEMPS BY THE END OF THE WEEK AS
THE UPPER FLOW FLATTENS. HOWEVER CONTINUED THE TREND OF
UNDERCUTTING MEX GUIDANCE AS THICKNESSES LOOK TO SUPPORT HIGHS IN
THE 40S. MEDIUM RANGE GUIDANCE CONTINUES TO INDICATE MORE OF A
WINTER-LIKE PATTEN TAKING SHAPE EARLY NEXT WEEK AS THE NEXT
SIGNIFICANT TROUGH SLIDES ACROSS THE PLAINS. COULD SEE EVEN COLDER
TEMPS WITH THIS SYSTEM BUT WILL HAVE TO WAIT AND SEE HOW THE MODELS
HANDLE THIS PATTERN.
CLK
FIRE WEATHER...
FIRE WEATHER CONCERNS WILL REMAIN LOW THROUGH THE FORECAST PERIOD AS
COLDER AIR ACROSS THE PANHANDLES WILL KEEP MINIMUM RELATIVE
HUMIDITIES ABOVE CRITICAL THRESHOLDS.
CLK
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
10/02
