AREA FORECAST DISCUSSION

 
 FXUS64 KEPZ 281928
 AFDEPZ
 
 AREA FORECAST DISCUSSION
 NATIONAL WEATHER SERVICE EL PASO TX/SANTA TERESA NM
 128 PM MDT THU AUG 28 2008
 
 .SYNOPSIS...
 EAST AND SOUTHEAST WINDS WILL TRANSPORT MOIST UNSTABLE AIR INTO
 SOUTHERN NEW MEXICO AND WESTERN TEXAS WHILE UPPER LEVEL
 DISTURBANCES MOVE INTO THE REGION. THIS WEATHER PATTERN WILL BRING
 SCATTERED SHOWERS AND THUNDERSTORMS TO THE REGION THROUGH THE
 WEEKEND LOCALLY HEAVY RAIN POSSIBLE. HIGH PRESSURE WILL RESULT IN
 WARM DRIER WEATHER LATER NEXT WEEK. 
 
 &&
 
 .DISCUSSION...
 EVOLVING WEATHER PATTERN STILL APPEARS FAVORABLE FOR CONVECTION
 WITH LOCALLY HEAVY RAINFALLS INTO EARLY NEXT WEEK. CURRENTLY
 ELONGATED EAST-WEST UPPER RIDGE EXTENDS ACROSS THE NEW MEXICO-
 COLORADO BORDER VICINITY WHILE LARGE UPPER LOW REMAINS ALMOST
 STATIONARY ACROSS NORTHWEST MEXICO AND BAJA. AT LOW LEVELS LITTLE
 HAS CHANGED AS SUMMER THERMAL LOW COVERS ARIZONA WITH HIGH
 PRESSURE EXTENDING INTO CENTRAL TEXAS. THIS OVERALL PATTERN NOT
 EXPECTED TO CHANGE MUCH THROUGH FRIDAY AFTERNOON WITH HEIGHT-
 PRESSURE ALIGNMENTS GENERATING DEEP LOWER AND MIDDLE TROPOSPHERIC
 EAST AND SOUTHEAST WINDS. AN EXAMINATION OF REGIONAL FLOW SHOWS
 TRAJECTORY FROM THE GULF OF MEXICO INTO THE CWA WITH MOISTURE
 REMAINING ABUNDANT AND PRECIPITABLE WATER SUSTAINED ABOVE 1.3
 INCHES INTO FRIDAY AFTERNOON. INSTABILITY WILL BE MODERATE DURING
 THE AFTERNOON AND EVENING WITH CAPES AROUND 1000 J/KG SO DEEP
 CONVECTION SEEMS POSSIBLE. MAIN UNCERTAINTY IS DEEPER FORCING
 MECHANISMS AS MODELS SUGGEST WEAK WAVES ALOFT EMBEDDED IN FLOW AND
 APPROACHING FROM THE EAST AND SOUTHEAST. THESE FEATURES DIFFICULT
 TO DETECT IN DATA VOID AREAS SO MORE PRECISE TIMING AND LOCATION
 OF STRONGER STORMS DIFFICULT. HOWEVER FORECAST SOUNDINGS SHOW
 LITTLE SPEED OR DIRECTIONAL SHEAR THROUGH THE MID LEVELS WITH
 WEAKER FLOW HIGHER UP INDICATING SOME BACK BUILDING MAY OCCUR WITH
 ASSOCIATED HEAVY RAINS.
 
 MODELS HAVE BEEN RATHER CONSISTENT IN MOVING HIGH AMPLITUDE SLOW
 MOVING TROUGH ACROSS THE PACIFIC INTO THE WESTERN U.S. WITH
 SYSTEM PHASING WITH UPPER LOW OVER BAJA BY SATURDAY. APPROACH OF THIS
 TROUGH WILL ALSO RESULT UPPER RIDGE AXIS REFORMING FURTHER EAST ON
 A NORTH-SOUTH ALIGNMENT INTO THE MID WEST. THESE TRENDS WILL
 DEEPEN SOUTHERLY WIND COMPONENT THROUGH THE CWA WITH PRECIPITABLE
 WATER INCREASING EVEN FURTHER TO NEAR 1.5. THUS HEAVY RAIN
 POTENTIAL WILL CONTINUE INTO THE WEEKEND AS MODELS CONTINUE TO
 MOVE WEAK EMBEDDED WAVES INTO THE AREA. RISK OF SEVERE WEATHER MAY
 INCREASE ON MONDAY AS PRIMARY UPPER TROUGH MOVES ACROSS THE ROCKY
 MOUNTAINS PROVIDING DEEPER LIFT AND STRONGER SHEAR.
 
 LATEST GUIDANCE STILL INFERS WARM DRIER WEATHER TUESDAY
 THROUGH WEDNESDAY AS MORE WESTERLY WINDS AND SURFACE HIGH
 PRESSURE BECOME ESTABLISHED BEHIND THE TROUGH. GFS SHOWS BACK
 DOOR FRONT INCREASING RAIN THREAT THURSDAY BUT WILL KEEP SLIGHT
 CHANCES IN FOR NOW.
 
 &&
 
 .AVIATION...
 SCATTERED AREAS OF MVFR AND ISOLATED IFR CEILINGS AND
 VISIBILITIES IN SHOWERS AND THUNDERSTORMS THROUGH FRIDAY. 
 
 &&
 
 .FIRE WEATHER...
 SOUTH TO SOUTHEAST WINDS WILL PUSH MOIST UNSTABLE AIR INTO NEW
 MEXICO AND WESTERN TEXAS INTO EARLY NEXT WEEK WHILE WEAK UPPER
 DISTURBANCES MOVE ITO THE REGION. THIS PATTERN WILL BRING
 SCATTERED SHOWERS AND THUNDERSTORMS WITH LOCALLY HEAVY RAINS
 THROUGH MONDAY. THUS THE FIRE DANGER SHOULD BECOME LOWER OVER THE
 NEXT SEVERAL DAYS DUE TO WIDESPREAD RAINS AND HIGH HUMIDITIES.
 
 &&
 
 .PRELIMINARY POINT TEMPS/POPS...
 EL PASO                 69  85  67  83  64 /  40  40  30  30  50 
 SIERRA BLANCA TX        60  83  61  79  57 /  40  40  30  30  50 
 LAS CRUCES              68  85  67  83  64 /  30  30  30  30  50 
 ALAMOGORDO              65  84  63  82  61 /  20  20  20  30  50 
 CLOUDCROFT              47  66  45  64  43 /  30  30  20  40  50 
 TRUTH OR CONSEQUENCES   65  84  64  80  62 /  20  20  20  30  50 
 SILVER CITY             59  78  58  75  56 /  30  30  30  30  40 
 DEMING                  65  85  64  82  62 /  30  30  30  30  50 
 LORDSBURG               64  84  63  81  62 /  40  30  30  30  50 
 
 &&
 
 .EPZ WATCHES/WARNINGS/ADVISORIES...
 NM...NONE.
 TX...NONE.
 &&
 
 

 
 05 ROGASH/ADAIR
 
 

Webmaster
US Dept of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
Tucson Weather Forecast Office
520 North Park Ave, Suite 304
Tucson, AZ 85719

Tel: (520) 670-6526