FXUS64 KAMA 272338 AAA
AFDAMA

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE AMARILLO TX
538 PM CST FRI NOV 27 2009

.AVIATION...
VFR FORECAST TO CONTINUE THE NEXT 24 HOURS. ONLY AVIATION CONCERN
WILL BE THE COLD FRONT MOVING THROUGH THE AREA ON SATURDAY. MAIN
IMPACT FROM FRONT WILL BE A WIND SHIFT TO A NORTHERLY DIRECTION.
BROUGHT THE FRONT THROUGH DHT/GUY AROUND 17Z...AND AMA AROUND 21Z.
WIND SPEEDS SHOULD REMAIN LESS THAN 15 KNOTS THROUGH THIS TAF CYCLE.

TAB

&&

.PREV DISCUSSION... /ISSUED 350 PM CST FRI NOV 27 2009/ 

DISCUSSION...
FORECAST ISSUES WILL CONTINUE TO BE ON PRECIP CHANCES SUNDAY WITH
NEXT SYSTEM SLATED TO IMPACT THE PANHANDLES.

WATER VAPOR IMAGERY THIS AFTERNOON SUGGESTING BROAD MID LEVEL RIDGE
ACROSS THE CENTRAL PLAINS WITH AN UPPER LEVEL TROUGH OVER THE
PACIFIC NORTHWEST. HIGH CLOUDS FROM UPPER WAVE MOVING ACROSS DEEP
SOUTH TX WILL KEEP SKIES PARTLY CLOUDY TONIGHT. SHOULD SEE TEMPS
SIMILAR TO LAST NIGHT WITH LOWS FROM THE UPPER 20S TO THE UPPER 30S.
UPPER TROUGH WILL DIVE FURTHER TO THE SOUTH SATURDAY WITH A LOW
CUTTING OFF OVER SOUTHERN CA. A NORTHERN STREAM TROUGH WILL PROPAGATE
ACROSS THE NORTHERN ROCKIES WHILE ITS ASSOCIATED COLD FRONT PUSHES
INTO THE NORTHERN PANHANDLES. THIS WILL SET UP A MORE PRONOUNCED
BAROCLINIC ZONE WITH HIGHS IN THE LOWER 60S NORTHERN SECTIONS TO
THE LOWER 70S IN THE SOUTHERN TX PANHANDLE.

FOCUS THEN SHIFTS TO PRECIP CHANCES ASSOCIATED WITH APPROACHING
SYSTEM. WITH THE LOW BECOMING CUT OFF OVER SOUTHERN CA...WILL SEE
THE UPPER FLOW TRANSITION TO THE SOUTHWEST. MOISTURE WILL START TO
INCREASE ACROSS THE AREA WHILE MODEST FRONTOGENESIS CAN SUPPORT SOME
LIGHT RAIN SATURDAY EVENING IN THE NORTHWEST ZONES. IN ADDITION...A
140KT JET STREAK WILL ROUND THE BASE OF THE TROUGH AND LIFT ACROSS
THE SOUTHERN PLAINS...ENHANCING UPWARD VERTICAL MOTION. MAIN PUSH OF
COLDER AIR WILL ARRIVE SUNDAY AS THE FRONT CONTINUES TO HEAD TO THE
SOUTH. WITH THIS IN MIND USED A NON DIURNAL TEMP TREND FOR SUNDAY
WITH THE DAYTIME HIGH BEING REACHED AROUND NOON WITH TEMPS FALLING
DURING THE AFTERNOON. SHOULD SEE A RAIN SNOW MIX CHANGING TO ALL
SNOW BY EVEING. NAM HAS SLOWED DOWN THE UPPER LOW AND HANGS IT BACK
WHILE THE GFS/UKMET/ECMWF ARE IN BETTER AGREEMENT. GIVEN
THIS...STAYED MORE WITH THE GFS IDEA OF CHANCE POPS SUNDAY. DID LOWER
SNOW TOTALS A LITTLE AS SYSTEM QUICKLY LIFTS ACROSS THE AREA. HAVE
PAINTED GRIDS WITH AROUND A HALF AN INCH IN THE NORTHWEST TO JUST A
COUPLE OF TENTHS OF AN INCH IN THE SOUTHEAST.

SHOULD SEE SKIES CLEAR MONDAY BUT WITH NORTHERLY SFC WINDS...SHOULD
SEE ANOTHER COOL DAY WITH HIGHS IN THE UPPER 40S TO LOWER 50S.
TEMPS SHOULD MODERATE TUESDAY AS THE UPPER LOW SLIDES ACROSS
SOUTHERN TX WITH LOW LEVEL WINDS VEERING TO THE SOUTHWEST. DRY
NORTHWEST FLOW DEVELOPS MID WEEK BUT MEDIUM RANGE MODELS INDICATE
THE NEXT SYSTEM TO APPROACH THE AREA BY THE END OF THE WEEK. MODELS
CONTINUE TO BE IN DISAGREEMENT WITH THE DEGREE OF COLD AIR WITH THIS
SYSTEM. WITH THIS IN MIND...LEFT TEMPS IN THE EXTENDED ALONE BUT
THIS BEARS WATCHING IN FUTURE MODEL RUNS. CLK

FIRE WEATHER...
A COLD FRONT WILL MOVE INTO THE PANHANDLES SATURDAY BUT IS NOT
EXPECTED TO PUSH THROUGH THE SOUTHERN TX PANHANDLE UNTIL LATE
SATURDAY NIGHT. RELATIVE HUMIDITIES AHEAD OF THE FRONT WILL FALL TO
BELOW 20 MPH BUT WITH 20 FOOT WIND SPEEDS GENERALLY AROUND 10 TO 15
MPH...FIRE WEATHER CONCERNS SHOULD REMAIN LOW. MUCH COLDER AIR
BEHIND THE FRONT WILL USHER IN COLDER TEMPERATURES FOR SUNDAY. WHILE
SOME MODERATION OF TEMPERATURES IS EXPECTED EARLY NEXT WEEK...NO
FIRE WEATHER CONCERNS ARE ANTICIPATED THROUGH THE REMAINDER OF THE
FORECAST PERIOD AS RELATIVE HUMIDITY VALUES REMAIN ABOVE CRITICAL
THRESHOLDS.  CLK

&&

.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.

&&

$$

10/02