FXUS64 KSJT 012201
AFDSJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
401 PM CST TUE DEC 1 2009
.SHORT TERM...
MODEL CONSENSUS SHOWS CLOSED UPPER LOW MOVING ACROSS I-10
CORRIDOR THROUGH 06Z THEN INTO EAST TEXAS BY 12Z. PRECIP HAS
REMAINED ALL RAIN TODAY BUT AN OBSERVER REPORTED SNOW MIXING WITH
THE RAIN IN THE SLIGHTLY HIGHER TERRAIN OF RUNNELS COUNTY AROUND
3 PM. PRECIP DECREASING ACROSS SOUTHWEST COUNTIES LATE THIS
AFTERNOON AS THE UPPER LOW APPROACHES BUT WILL STILL SEE CHANCE
TO LIKELY POPS CONTINUE OVER CENTRAL AND NORTHERN SECTIONS THIS
EVENING. SFC TEMPS WILL COOL A FEW DEGREES BY MID TO LATE EVENING
AND THIS COMBINED WITH COOLING ALOFT WITH THE APPROACH OF THE
UPPER LOW SHOULD ALLOW FOR A MIX OF RAIN AND SNOW OVER THE
WESTERN HALF OF THE CWFA WITH RAIN ELSEWHERE. MODELS CONTINUE TO
SHOW SOME LIGHT DEFORMATION BAND PRECIP AFTER MIDNIGHT WITH
FORECAST SOUNDINGS INDICATING MOSTLY SNOW ACROSS MUCH OF THE
CONCHO VALLEY AND WESTERN TWO THIRDS OF THE BIG COUNTRY WITH A
MIX OF RAIN AND SNOW ELSEWHERE. SOME LIGHT ACCUMULATIONS WILL BE
POSSIBLE MAINLY ACROSS THE NORTHERN CONCHO VALLEY AND THE BIG
COUNTRY BUT WILL HOLD OFF ON ANY ADVISORIES AT THIS TIME AND LET
THE EVENING SHIFT SEE HOW THINGS MATERIALIZE. OVERNIGHT LOWS
SHOULD REMAIN ABOVE FREEZING WITH LOWS IN THE LOW TO MID 30S.
PRECIP ENDS EARLY WED MORNING WITH DECREASING CLOUDS BY
AFTERNOON. DESPITE SOME SUN...WENT SLIGHTLY BELOW GUIDANCE FOR
HIGHS ON WED GIVEN DECENT LOW LEVEL COLD AIR ADVECTION WITH HIGHS
MID 40S NORTH TO UPPER 40S SOUTH.
24
.LONG TERM...
...WINTRY WEATHER POSSIBLE THURSDAY NIGHT INTO FRIDAY...
UPPER TROUGH IN PACIFIC NW...WILL MOVE INTO THE REGION BEGINNING
THURSDAY EVENING AND ENDING AROUND NOON FRIDAY. THERE WAS VERY
GOOD DYNAMICS AND LIFT FROM 500 TO 800 MB WITH THIS SYSTEM.
ALSO...THERE WAS NO SHORTAGE OF COLD AIR FOR SNOW. PROFILES
SOUNDINGS FOR ABILENE... SAN ANGELO...JUNCTION ALL SHOW A SNOW
PROFILE WITH SOUNDINGS BELOW FREEZING AND SATURATING IN THE
LOW/MID LEVELS BY THURSDAY MIDNIGHT. GFS AND NAM QFP (RAINFALL)
COMES IN AROUND .10 TO .40 INCHES...OR 1 TO 4 INCHES OF SNOW AT A
1 TO 10 RATIO. WILL NOT GO THAT HIGH ON QPF AND SNOW
ACCUMULATIONS ON THIS FORECAST...KEEPING SNOW AMOUNTS IN WEATHER
GRIDS LESS THAN 1 INCH. HOWEVER WITH THE VERY STRONG JETS AND
DYNAMIC...THAT MAY CHANGE IN LATER RUNS...AS CONFIDENCE INCREASES
AS THE EVENT APPROACHES. NAM AND GFS ARE CLOSE IN
AGREEMENT...WITH THE ECMWF DELAYING THE SYSTEM AND PRECIPITATION
UNTIL AFTER 6 AM FRIDAY.
WITH LIGHT WINDS AND CLEANING SKIES FRIDAY NIGHT...SHOULD SEE
GOOD RADIATIONAL COOLING AND OVERNIGHT LOWS IN THE MID 20S.
OTHERWISE WARMING TREND THIS WEEKEND...WITH ANOTHER UPPER TROUGH
POSSIBLY AFFECTING THE REGION TUESDAY.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 34 45 29 39 25 / 60 20 0 10 30
SAN ANGELO 34 48 30 39 27 / 30 10 0 10 30
JUNCTION 34 52 32 45 32 / 20 10 10 10 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
04
