000 FXUS64 KMAF 061802 AFDMAF AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 1202 PM CST FRI MAR 6 2009 .DISCUSSION... SEE AVIATION DISCUSSION BELOW. && .AVIATION... VFR CONDITIONS EXPECTED AREAWIDE FOR THE NEXT 24 HOURS WITH SCATTERED TO BROKEN LAYERS OF MIDDLE TO HIGH LEVEL CLOUDINESS. AN EXCEPTION TO ABOVE MENTIONED VFR CONDITIONS WILL BE AROUND DAYBREAK SATURDAY MORNING WHERE A MOIST 45-50KT SOUTHERLY LOW LEVEL JET WILL AID IN DEVELOPING MVFR LOW CLOUDS /BKN020/ NEAR THE KMAF TERMINAL. ALSO...A DEEPENING SURFACE LOW PRESSURE AND ASSOCIATED LEE SIDE TROUGH WILL RESULT IN GUSTY SOUTH TO SOUTHWEST WITH WINDS GUSTING UP TO 25 KNOTS AT TIMES THIS AFTERNOON . SOME DECOUPLING OF WINDS EXPECTED OVERNIGHT AS A SOUTHERLY LOW LEVEL JET DEVELOPS...WITH POTENTIAL LOW LEVEL WIND SHEAR VICINITY KMAF BETWEEN 05Z AND 11Z SATURDAY. && .PREV DISCUSSION... /ISSUED 455 AM CST FRI MAR 6 2009/ DISCUSSION... EARLY MORNING ANALYSIS CONTINUES WITH SOUTHWEST FLOW ALOFT OVER WEST TEXAS AS AN UPPER LEVEL SHORTWAVE TROUGH...VISIBLE IN WATER VAPOR IMAGERY...MOVES EAST OUT OF SOUTHERN CALIFORNIA. NORTH OF THIS FEATURE...ANOTHER VORT MAX IS NOW DIVING SOUTH OUT OF WESTERN CANADA. THE LATTER FEATURE WILL RESULT IN A POSITIVELY TILTED TROUGH JUST NORTHWEST OF THE FOUR CORNERS REGION BY SATURDAY MORNING. WITH MID TO UPPER LEVEL FLOW ON THE BACKSIDE OF THIS UL TROUGH RELATIVELY WEAK AND GREATEST HEIGHT FALLS OCCURRING OVER SOUTH CENTRAL PLAINS SATURDAY AFTERNOON AND THEN NORTHEAST TOWARDS GREAT LAKES...ONE WOULD EXPECT LIMITED POTENTIAL FOR IT TO DIG MUCH FURTHER TO THE SOUTH. FOR THIS REASON...EXPECTING WIND MAKER THIS TIME AROUND AS MID TO UPPER LEVEL HEIGHT GRADIENT INCREASES ALONG WITH SFC PRESSURE GRADIENT. ONLY MINOR POPS OVER EXTREME EASTERN PORTIONS OF CWA (NEAR DRYLINE) AND SOUTH CENTRAL NEW MEXICO (NEAR WEAK UL JET SUPPORT) WILL BE INCLUDED FOR SATURDAY. SUBTROPICAL FETCH OF MOISTURE WILL CONTINUE TO RESULT IN CIRRUS THROUGH MOST OF THE WEEKEND...WITH SOME BREAKS TODAY...UNTIL UPPER LOW EJECTS NORTHEASTWARD. LOW CLOUD WILL BE POSSIBLE AS WELL FOR THIS MORNING ACROSS SOUTHEASTERN PORTIONS OF THE CWA AS LOW LEVEL JET CONTINUES TO ADVECT MOISTURE. LOWS THIS MORNING WILL BE RATHER WARM AS A RESULT. TEMPS TODAY WILL BE COOLER THAN YESTERDAY AS 850 MB THERMAL RIDGE SHIFTS SLIGHTLY TO THE WEST...WITH LEE LOW NEAR KS/CO BORDER...AND DOWNSLOPE COMPONENT WEAKENING. LOWS WILL REMAIN ON THE WARM SIDE SATURDAY MORNING AS BOUNDARY LAYER MOISTURE ADVECTION CONTINUES. DRYLINE WILL MOST LIKELY BE POSITIONED ALONG OUR EASTERN CWA BORDER BY LATE SATURDAY AFTERNOON AND PACIFIC FRONT WILL FOLLOW....COOLING TEMPS FOR SUNDAY. WILL NEED TO WATCH HIGH WIND POTENTIAL FOR THE GUADALUPE MOUNTAINS SATURDAY WITH INCREASED MID LEVEL FLOW AND PERHAPS SLIGHT CHANCE OF VIRGA OVER REGION. A HIGH WIND WATCH WILL BE ISSUED THIS MORNING. MAV GUIDANCE CONTINUES TO SHOW THIS AS WELL. WINDS MAY ALSO APPROACH ADVISORY LEVEL CRITERIA IN THE SOUTHEAST NM PLAINS...BUT SHOULD REMAIN JUST BELOW OVER PERMIAN BASIN AND UPPER TRANS PECOS. NEXT FEATURES TO KEEP AN EYE ON WILL BE EMBEDDED SHORTWAVE TROUGHS IN SOUTHWEST FLOW ALOFT EARLY NEXT WEEK MOVING OVER SOUTHWEST TEXAS AND COLD FRONT MAKING ITS WAY DOWN THE PLAINS LATE TUESDAY. BOTH GFS AND ECMWF DEPICT FIRST SIGNIFICANT SHORTWAVE TROUGH MOVING OVER REGION SOMETIME WEDNESDAY AND TIMING OF THIS FEATURE WITH FRONTAL POSITION COULD RESULT IN DECENT POPS FOR THE FORECAST AT THIS TIME. WILL INCREASE POPS SLIGHTLY...BUT STILL STAY ON LOW SIDE AS CONFIDENCE IN TIMING STILL A CONCERN. FIRE WEATHER... THE CONTINUATION OF UNSEASONABLY WARM TEMPERATURES AND DRY LOWER LEVEL WILL RESULT IN VERY LOW RH WEST OF A SURFACE TROUGH WHICH SHOULD SET UP NEAR A HOBBS TO FT DAVIS LINE BY THIS AFTERNOON. MIN RH OF 10 PERCENT OR LESS WILL BE POSSIBLE. LIMITING FACTOR ACROSS THE SOUTHWEST WILL BE LOWER WIND SPEEDS... HOWEVER HIGHER 850 AND 700 MB SPEEDS OVER SOUTHEAST NEW MEXICO SHOULD MIX DOWN THIS AFTERNOON AND REACH 20 MPH OR GREATER AT 20 FEET. THESE FEATURES COMBINED WITH HIGH TO VERY HIGH FIRE DANGER WILL RESULT IN NEED FOR UPGRADE OF FIRE WX WATCH FOR SOUTHEAST NM TO A RED FLAG WARNING THIS AFTERNOON. SATURDAY LOOKS TO BE A BIGGER FIRE WX DAY AS A STRONG UPPER TROUGH SWINGS ACROSS THE ROCKIES AND A DRYLINE MOVES EAST AS THE SURFACE LOW DRAGS ACROSS THE PANHANDLE. THIS WILL ALLOW VERY LOW RH TO SPREAD ACROSS MOST OF THE REGION SATURDAY AFTERNOON. THE COMBINATION OF THIS DEEPENING SURFACE LOW AND STRONGER MID LEVEL WINDS SATURDAY WILL RESULT IN WINDIER CONDITIONS. THEREFORE WILL CONTINUE FIRE WX WATCH SATURDAY ALONG AND NORTH OF A VAN HORN TO IRAAN LINE. LATER SHIFTS MAY NEED TO REFINE EASTERN OR SOUTHERN EXTENT OF WATCH. && .MAF WATCHES/WARNINGS/ADVISORIES... NM...FIRE WEATHER WATCH FROM SATURDAY MORNING THROUGH SATURDAY EVENING FOR THE FOLLOWING ZONES... SOUTHEAST PLAINS/BLM ROSWELL/LNZ. RED FLAG WARNING UNTIL 7 PM MST THIS EVENING FOR THE FOLLOWING ZONES... GUADALUPE MOUNTAINS NP/LINCOLN NF/LNZ...SOUTHEAST PLAINS/BLM ROSWELL/LNZ. FIRE WEATHER WATCH FROM LATE TONIGHT THROUGH SATURDAY EVENING FOR THE FOLLOWING ZONES... GUADALUPE MOUNTAINS NP/LINCOLN NF/LNZ. HIGH WIND WATCH FROM LATE TONIGHT THROUGH SATURDAY EVENING FOR THE FOLLOWING ZONES... GUADALUPE MOUNTAINS OF EDDY COUNTY. TX...FIRE WEATHER WATCH FROM SATURDAY MORNING THROUGH SATURDAY EVENING FOR THE FOLLOWING ZONES... ANDREWS...BORDEN... CRANE...DAVIS/APACHE MOUNTAINS AREA...DAWSON...ECTOR... GAINES...GLASSCOCK...HOWARD...LOVING...MARTIN...MIDLAND... MITCHELL...PECOS...REAGAN...REEVES COUNTY AND UPPER TRANS PECOS...SCURRY...UPTON...VAN HORN AND HIGHWAY 54 CORRIDOR... WARD...WINKLER. RED FLAG WARNING UNTIL 7 PM MST THIS EVENING FOR THE FOLLOWING ZONES... GUADALUPE MOUNTAINS. FIRE WEATHER WATCH FROM LATE TONIGHT THROUGH SATURDAY EVENING FOR THE FOLLOWING ZONES... GUADALUPE MOUNTAINS. HIGH WIND WATCH FROM LATE TONIGHT THROUGH SATURDAY EVENING FOR THE FOLLOWING ZONES... GUADALUPE MOUNTAINS. && $$