000 FXUS64 KMAF 301131 AFDMAF AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 631 AM CDT SAT AUG 30 2008 .DISCUSSION... SEE AVIATION DISCUSSION BELOW. && .AVIATION... SHOWER ACTIVITY HAS ENDED ACROSS THE AREA THIS MORNING...BUT EXPECT IT TO FIRE BACK UP LATE THIS MORNING OR THIS AFTERNOON. MOST OF THE SHOWERS WILL HAVE TO WAIT FOR AFTERNOON HEATING WHICH IS WHEN THE TAF SITES WILL HAVE THE GREATEST RAIN CHANCES. DID NOT MENTION TS IN THE TAFS SONCE MOST OF THE SHOWERS TODAY LACKED LIGHTNING THOUGH OCCASIONAL LIGHTING WILL CERTAINLY BE POSSIBLE. MVFR CIGS SHOULD NOT BE MUCH OF A PROBLEM...THEY BRIEFLY APPEARED AT PEQ BUT AM NOT EXPECTING THEM TO REAPPEAR THROUGH THE TAF PERIOD. WINDS WILL BE LIGHT FROM A NORTHEAST OR SOUTHEASTERLY DIRECTION. && .PREV DISCUSSION... /ISSUED 412 AM CDT SAT AUG 30 2008/ DISCUSSION... AREAL SHOWERS HAVE GRADUALLY WEAKENED OVER THE LAST SEVERAL HOURS. GENERALLY LIGHT SCATTERED SHOWERS ARE TRACKING NORTHWESTWARD ACROSS MUCH OF WEST TEXAS WITH A FEW STRONGER ONES IN SOUTHEAST NEW MEXICO. EXPECTING A SLIGHT DISSIPATION INTO THE LATE MORNING HOURS. AN UPPER LEVEL LOW HAS MOVED LITTLE FROM ITS POSITION OVER NORTHWESTERN MEXICO. A STEADY STREAM OF DEEP MOISTURE HAS CONTINUED TO SURGED INTO THE REGION. A SHORTWAVE SEEN ON WATER VAPOR IMAGERY ROTATING AROUND THE UPPER LOW IS EXPECTED TO TRACK INTO AND ACROSS THE SOUTHERN PORTION OF THE CWA. OROGRAPHIC LIFT ALONG WITH UPPER LEVEL LIFT SHOULD WILL PROVIDE THE POTENTIAL FOR HEAVY RAINFALL BASICALLY FROM THE BIG BEND REGION NORTHWESTWARD INTO THE GUADALUPE MOUNTAINS. DECIDED TO EXTEND HIGHEST POPS ALONG THIS REGION AND MAINTAIN FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR AREAS SOUTH AND WEST OF THE PECOS RIVER. ELSEWHERE ACROSS THE CWA...CAN EXPECT MORE SCATTERED SHOWERS TO DEVELOP IN THE AFTERNOON. MOVING INTO TONIGHT...A SHORTWAVE IS PROGGED TO TRACK NORTHWARD ALONG THE SOUTHEASTERN PORTION OF THE CWA. SO DECIDED TO INCREASE POPS ALONG THE STOCKTON PLATEAU AND LOWER TRANS PECOS. TEMPS SHOULD BE ONCE AGAIN ON THE MILD SIDE TODAY WITH EXTENSIVE CLOUD COVER ACROSS THE ENTIRE AREA AND ESPECIALLY SOUTH WHERE MOST OF HEAVIER RAIN IS EXPECTED. SPREAD OUT UPPER LEVEL RIDGE TO THE NORTH OF THE AREA IS IN THE PROCESS OF BEING BROKEN OFF AND WILL CONTINUE TO SHIFT EASTWARD. AN UPPER LEVEL TROUGH IS CURRENTLY ENTERING THE PACIFIC NORTHWEST. THIS SYSTEM WILL DIG SOUTHWARD AND THEN TRACK ACROSS THE CENTRAL ROCKIES. IN THE MEANTIME...SHORTWAVES WILL TRACK NORTHEASTWARD ALONG AND IN BETWEEN THE TROUGH AND RIDGE. THUS...EXPECTING INCREASED POPS TO CONTINUE ACROSS THE WESTERN HALF OF THE AREA THROUGH THE WEEKEND. TEMPERATURES SHOULD ALSO BEGIN TO MODERATE EACH DAY AND RETURN TO NEAR NORMAL BY MONDAY WITH THE EXCEPTION OF WESTERN AREAS WITH HIGHER POPS. AS THE AFOREMENTIONED TROUGH TRACKS EASTWARD ACROSS THE CONUS...A COLD FRONT LOOKS TO GET PUSHED INTO THE REGION. WHILE MODELS AGREE ON A FRONT COMING IN...THERES CONSIDERABLE DISAGREEMENT IN TIMING. ECMWF IS THE MOST AGGRESSIVE AND HAS THE FRONT IN THE AREA BY TUESDAY AFTERNOON WHILE THE GFS IS ABOUT 12 HOURS SLOWER WITH ITS PROGRESSION. THIS DOESN/T REALLY CORRELATE WELL TO THE FORECASTED STRENGTH AND N/S TRACK OF EACH MODEL B/C THE GFS IS DEEPER AND MORE SOUTH WHICH SHOULD RESULT IN A FASTER FRONT. THE NAM IS SIGNIFICANTLY SLOWER THAN THE OTHER 2 WITH FRONT REACHING THE NORTHERN PERMIAN BASIN THURSDAY MORNING AND THEN STALLS OUT. SO...DID/T MAKE TOO MANY CHANGES TO EXTENDED FORECAST BUT KEPT MENTION OF SLGT CHNC OF RAIN. MEFFER && .MAF WATCHES/WARNINGS/ADVISORIES... NM...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR THE FOLLOWING ZONES... EDDY COUNTY PLAINS...GUADALUPE MOUNTAINS OF EDDY COUNTY. TX...FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES... BIG BEND AREA...DAVIS/APACHE MOUNTAINS AREA...GUADALUPE MOUNTAINS...MARFA PLATEAU...PECOS...PRESIDIO VALLEY... REEVES COUNTY AND UPPER TRANS PECOS...TERRELL...VAN HORN AND HIGHWAY 54 CORRIDOR. && $$ 10