000
FXUS64 KEPZ 092200
AFDEPZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EL PASO TX/SANTA TERESA NM
300 PM MST TUE FEB 9 2010

.SYNOPSIS...
ANOTHER IN A SERIES OF STORM SYSTEMS ALONG THE CALIFORNIA COAST
WILL MOVE INTO THE BAJA CALIFORNIA REGION WEDNESDAY MORNING BEFORE
STARTING TO TRACK EAST SOUTHEASTWARD. AS THIS SYSTEM MOVES ACROSS
SOUTHERN ARIZONA WEDNESDAY...IT WILL START TO ADVECT INCREASING
CLOUDS AND RAIN SHOWERS INTO THE BORDERLAND BY WEDNESDAY AFTERNOON.
SOME EMBEDDED THUNDERSTORM ACTIVITY WITH ICE PELLETS IS ALSO POSSIBLE
ALONG WITH LOCALLY MODERATE TO HEAVY SHOWERS IN SOME LOCATIONS
INTO WEDNESDAY EVENING. THE HIGHER ELEVATIONS OF THE GILA
WILDERNESS AND THE SOUTHERN SACRAMENTO MOUNTAINS MAY SEE SOME
MODERATE TO HEAVY SNOW IN THIS SAME PERIOD. SNOW LEVELS SHOULD
STAY AROUND 5500 FEET...BUT LOWLAND AREAS SUCH AS SIERRA AND
HUDSPETH COUNTIES AND LOCATIONS NEAR FOOTHILLS AND MOUNTAIN PASSES
MIGHT SEE A MIXTURE OF RAIN AND SNOW LATE WEDNESDAY NIGHT AND
THURSDAY MORNING. THIS SYSTEM SHOULD EXIT THE BORDERLAND BY
THURSDAY EVENING...FOLLOWED BY A RIDGE OF HIGH PRESSURE MOVING
INTO THE DESERT SOUTHWEST FRIDAY THROUGH THE WEEKEND...GIVING US A
DRIER AND WARMER WEATHER PATTERN.


&&

.DISCUSSION...
BACKDOOR FRONT MOVED IN LAST EVENING ON SCHEDULE...DID NOT CHARGE
IN BUT JUST  PUSHED IN FROM THE ESE VS NE RESULTING IN A COOLER
DAY AND PATCHY/SCT LOW CLDS EAST OF THE FRANKLINS ALONG WITH THE
CHARACTERISTIC BACKDOOR DUST HAZE. AN INTERESTING NOTE: THE THIN
LINE OF CI OVER KELP THIS MORNING WAS ASSOCIATED WITH A VERY STG
STJ OF 195KTS AT 250 MB HERALDING AHEAD OF OUT FUTURE STORM SYSTEM.

NEXT SYSTEM ON SCHEDULE. TRENDS IN THE MODELS WITH THIS SYSTEM ARE
GENERALLY ABOUT 6 HOURS SLOWER AND TRACKING A LITTLE FARTHER
SOUTH THAN YESTERDAY`S RUNS. THE EC MODEL IS THE FASTEST AND THE NAM
THE SLOWEST WITH THE GFS THE MIDDLE COMPROMISE. AS OF 21Z..LOW UPPER
JUST OFF THE CENTRAL CALIFORNIA COASTLINE WITH EXTENSIVE COLD AIR
CU DOWN TO THE SAN DIEGO AREA WITH THE ASSOCIATED PACIFIC COLD
FRONT FROM ARN KSFO SOUTHWARD TO THE KSAN. LOW TO TRACK SOUTHEAST
TO BAJA CALIF BY 12Z WED THEN ESE JUST SOUTH OF THE INTERNATIONAL BORDER.
THE COMPROMISE GFS PLACES A SMALL CLOSED LOW ALOFT (~ -26C AT H5)
JUST SOUTH OF EL PASO0 AROUND 18Z THU BEFORE OPENING AND MOVING
EASTWARD BY SUNSET. THE FORECAST NAM/GFS SOUNDINGS ARE IMPRESSIVE
FROM 10/18Z-11/02Z WITH .5 PW AND A FORECAST LI OF -1 TO -2 GIVING
LIFT TO AROUND 25K FT MSL. AS THE SOUTHERN BRANCH OF THE STJ MOVES
INTO OUR AREA BY WED AFTN PRODUCING MORE VERTICAL SPEED SHEAR AND
SIGNIFICANT DIFFLUENCE...THUNDER WITH HAIL IS LIKELY. THE FCST SPEED
SHEAR IS ARN 30 TO 40 KTS FROM 850 TO 600 MB ALONG WITH ABOUT 90
DEG OF DIRC SHEAR VEERING FROM SSE IN THE LOWER LEVELS TO WSW AT
75 KTS AT 400 MB. QPF SUGGESTS 4 TO 8 INCHES OF HIGHER ELV SNOW
(AND EVEN HIGHER AMTS ABOVE 7500) AND THUS WATCHES WERE ISSUED FOR
NM ZONES 22 AND 25. WITH A LITTLE SLOWER MOVEMENT AND A SLIGHTLY
MORE SOUTHERN TRACK IN TODAY`S RUNS...BELIEVE THERE WILL NOT BE
ENOUGH COLD AIR (BOUNDARY LAYER TEMPS A TAD TOO WARM ALONG WITH A
WBZ ELV ARN 850 MB) AT THE LOWEST ELEVATIONS FOR ANY SIGNIFICANT
SNOWFALL LATE WED/EARLY THURSDAY BUT WITH SNOW LEVELS DOWN TO
5500-6000 FEET...DID MENTION A POSSIBILITY OF RA/SN MIX 09Z-15Z
ESPLY NEAR FOOTHILLS AND PASSES WITH NO SIG ACCUM. THIS WILL HAVE
TO BE MONITORED ESPLY IN SIERRA...EASTERN OTERO...AND HUDSPETH
COUNTIES. ALSO NOTED IS THE OPTICAL STRONG UVV IN THE OMEGA FIELD
FROM 18Z WED TO 06Z THURS WITH STRONG ATTENDANT DIFFERENTIAL
VORTICITY ADVECTION 00Z-06Z THURSDAY.

&&

.AVIATION...VALID 10/00Z-11/00Z...
VFR CONDITIONS ARE EXPECTED THROUGH AT LEAST 10/22Z WEDNESDAY AFTN
FOR ALL TERMINALS.  SOUTHWEST FLOW AHEAD OF STRONG WINTER STORM
SYSTEM APPROACHING FROM THE WEST WILL DRAW UP SUBSTANTIAL
SUB-TROPICAL MOISTURE BEGINNING WED AFTN.  IN ADDITION AREAS OF LIFT
IN THE MIDDLE AND UPPER ATMOSPHERE...ARE EXPECTED TO DEVELOP AHEAD
OF THIS SYSTEM.  HAVE HIGH CONFIDENCE THIS WILL HELP DEVELOP AREAS
OF SHOWERS AND CHANCES FOR ISOLATED -TSRA GENERALLY SW OF A
ELP-DMN-LSB LINE AFT 19Z .  FZ LVLS LIKELY TO BRIEFLY BEGIN ABV 3KFT
AGL END OF PERIOD...LOWERING THROUGH THE WED NIGHT 1000 FT OR MORE.

&&

.FIRE WEATHER...WEAK HIGH PRESSURE RIDGE ALOFT OVER THE AREA WILL
PRECLUDE WETTING PRECIPITATION FOR OUR ZONES THROUGH AT LEAST MID
DAY WEDNESDAY...BEFORE MOVING EAST AND ALLOWING STRONG WINTER STORM
SYSTEM TO PUSH INTO THE OUR AREA FROM THE WEST. SOUTHWEST FLOW AHEAD
OF THIS SYSTEM WILL DRAW UP SUBSTANTIAL SUB-TROPICAL MOISTURE
BEGINNING WED AFTN. WITH ADDED LIFT AND RELATIVELY COLDER AIR ALOFT
WITH THIS SYSTEM...RIGHT INGREDIENTS IN PLACE FOR SHOWERS AND
ISOLATED STORMS AS EARLY AS WEDNESDAY AFTERNOON BEGINNING IN THE
BOOTHEEL. SHOWERS AND ANY STORMS WILL SPREAD GENERALLY NORTHEAST
ACROSS OUR ZONES WEDNESDAY NIGHT.

4 TO 8 INCHES OF ACCUMULATING SNOWFALL GENERALLY ABOVE 6000 FEET
ACROSS THE GILA WILDERNESS...SACRAMENTO AND CAPITAN MOUNTAINS. LOCAL
AMOUNTS IN FAVORED LOCATIONS MAY APPROACH 1 FOOT. SNOW LEVELS WILL
FALL THROUGH WEDNESDAY EVENING...POSSIBLY DROPPING BELOW 5000 FT
THURSDAY MORNING. SNOW MAY BEGIN BRIEFLY AS HIGH AS 7000-7500
WEDNESDAY AFTERNOON OUT IN THE BOOTHEEL AND POSSIBLY FALL BELOW 5000
FEET THURSDAY MORNING. TEMPERATURES SHOULD RUN ROUGHLY 6 TO 11
DEGREES BELOW NORMAL THROUGH THURSDAY...FOLLOWED BY A GRADUAL
WARM-UP AS PATTERN WITH DRY WEST-NORTHWESTERLY FLOW DEVELOPS OVER
THE REGION BY WEEKS END.

22 - TRIPOLI


&&

.PRELIMINARY POINT TEMPS/POPS...
EL PASO                 37  54  37  51  36 /   0  10  50  40   0
SIERRA BLANCA TX        29  49  32  46  32 /   0  10  40  40  10
LAS CRUCES              35  54  36  51  33 /   0  10  60  40   0
ALAMOGORDO              33  51  35  48  34 /   0  10  60  40  10
CLOUDCROFT              19  34  19  30  19 /   0  10  60  40  10
TRUTH OR CONSEQUENCES   32  51  34  48  33 /   0  30  70  40   0
SILVER CITY             26  45  29  37  28 /   0  30  70  20   0
DEMING                  34  53  36  49  34 /   0  20  70  30   0
LORDSBURG               33  51  35  48  32 /   0  30  70  30   0

&&

.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
     AFTERNOON FOR NMZ022-025.

TX...NONE.
&&

$$

20/22 NOVLAN / TRIPOLI