000 FXUS64 KBMX 111140 AFDBMX AREA FORECAST DISCUSSION...UDPATED NATIONAL WEATHER SERVICE BIRMINGHAM AL 640 AM CST MON FEB 11 2008 .UPDATE...UPDATED FOR 12Z AVIATION DISCUSSION. && .SHORT TERM...TODAY AND TONIGHT. TRICKY LITTLE FORECAST TODAY TEMPERATURE- AND DEWPOINT-WISE...MORE STRAIGHTFORWARD IN THE SENSIBLE WEATHER DEPARTMENT. DOUBLE BARREL OF DISTURBANCES AIMED AT US...UPPER LOW EXITING MEXICO IN THE SOUTHERN STREAM...AND DIGGING DISTURBANCE RACING TO THE SOUTHEAST OUT OF THE ROCKIES IN THE NORTHERN STREAM. WATER VAPOR SHOWS A BIT OF A DRY SLOT BETWEEN THE TWO STREAMS...AND SHOULD KEEP SUNNY TO MOSTLY SUNNY SKIES THROUGH THE DAY. EXPECT HIGH CLOUDS TO MOVE IN FROM THE SOUTH FIRST TONIGHT...FOLLOWED BY INCREASING CLOUDS FROM THE NORTHWEST. SURFACE BOUNDARY ALREADY IN PLACE ACROSS THE SOUTH AMPLIFIES WITH THE UPPER LEVEL SUPPORT OVERNIGHT TONIGHT...AND APPROACHES THE NORTHWESTERN CORNER OF CENTRAL ALABAMA BY SUNRISE TUESDAY. WILL ADD JUST THE SLIGHTEST POPS AND SLIGHT CHANCE OF SHOWERS LATE TONIGHT FOR THAT AREA. BIG DEBATE IS IN THE TEMPS AND DEWPOINTS...WHICH HAVE BEEN VERY POORLY FORECAST BY THE MODELS OVER THE WEEKEND. JUST SEEMS LIKE THE MOS EQUATIONS ARE NOT HANDLING THE ANOMALOUSLY DRY AIR MASS WELL AT ALL. WE HAVE WARMED UP A BIT MORE THAN EXPECTED THE LAST FEW DAYS... WHICH GOES RIGHT ALONG WITH DEWPOINTS BEING LOWER THAN EXPECTED. LOCAL THICKNESS SCHEMES SUPPORT WARMER TEMPS THAN MAV...EVEN WITH GFS THICKNESSES...SO WILL TAKE A BLEND OF MAV AND MET FOR TODAYS HIGHS. WILL ALSO UNDERSHOOT GUIDANCE DEWPOINTS. NET RESULT HERE IS PERIOD OF RELATIVE HUMIDITY BELOW 25 PERCENT...WHICH MEANS A HIGH FIRE DANGER FOR THIS AFTERNOON. JD/81 .LONG TERM...TUESDAY THROUGH MONDAY. COLD FRONT...ACROSS THE NORTHWESTERN PORTIONS...WILL BEGIN TO SLOWLY SLIDE THROUGH CENTRAL ALABAMA BEGINNING TUESDAY MORNING. LOOK FOR THE FRONT EDGE OF THE RAIN TO BE JUST SOUTH OF INTERSTATE 59 BY THE LATE AFTERNOON TUESDAY. THAT FRONT END WILL BE NEAR THE INTERSTATE 85 CORRIDOR BY 9 PM. THE BACK END OF THE RAIN SHIELD WILL BE ABOUT 6 TO 9 HOURS LATER. SO THIS COULD POSSIBLY BE A PRETTY GOOD SOAKER FOR PORTIONS OF CENTRAL ALABAMA. MOST OF THE RAIN WILL BE OUT OF CENTRAL ALABAMA BY 6 AM ON WEDNESDAY...BUT WENT AHEAD AND STUCK WITH SOME SLIGHT CHANCES ACROSS THE FAR SOUTHEAST TO ACCOUNT FOR ANY LINGERING RAIN. WENT VERY CLOSE TO SREF MODEL CONSENSUS FOR POPS...WHICH ARE HIGHER THAN GFS MOS AND ACTUALLY LOWER THAN MET MOS FOR TUESDAY. MODELS ARE IN CLOSE AGREEMENT ON TUESDAY NIGHT...WHEN THE BULK OF THE RAIN WILL BE IN PLACE. WILL CONTINUE TO STICK WITH STRONG WORDING IN THE HAZARDOUS WEATHER...AS THERE WILL CONTINUE TO BE SOME DESCENT INSTABILITY IN PLACE. THERE IS A SLIGHT RISK OF SEVERE WEATHER TO THE SOUTHWEST OF CENTRAL ALABAMA. SO WILL NEED TO MONITOR CONDITIONS TO SEE IF THIS RISK MAY MOVE FURTHER NORTH. ONCE THIS SYSTEM CLEARS EARLY WEDNESDAY...WILL SEE A FEW DRY DAYS...WITH THE NEXT SYSTEM APPROACHING THE AREA FRIDAY. HERE IS WHERE THE MEDIUM TERM MODELS DISAGREE SOME. THE CANADIAN AND GFS AGREE WITH WITH A SOLUTION THAT BRINGS THE NEXT SYSTEM THROUGH ON SATURDAY. THE GFS AND CANADIAN HAVE THE HEAVIEST PRECIPITATION OVER THE AREA BY SATURDAY MORNING. THE ECMWF...HOWEVER...IS A GOOD 18 TO 24 SLOWER. GIVEN THE CONSENSUS APPROACH AND FORECAST CONSISTENCY WILL HEDGE CLOSER TO THE GFS. HAVE ADJUSTED TIMING SOMEWHAT SLOWER THAN THE GFS BUT ONLY BY ABOUT 6 HOURS. SOME INSTABILITY EXIST WITH THIS SYSTEM SO WILL CONTINUE WITH SOME STRONG STORMS POSSIBLE. WILL DEFINITELY NEED TO MONITOR THIS TIMING OVER THE NEXT SEVERAL DAYS AS THERE WILL LIKELY BE SOME HEDGING HERE AND THERE. TIMING COULD BE A BIG PLAYER IN THE SEVERE WEATHER POTENTIAL. 16 && .AVIATION...12Z TAF DISCUSSION. VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD. HIGH CLOUDS WILL SPREAD IN FROM THE WEST THIS AFTERNOON AND EVENING...GRADUALLY THICKENING AND LOWERING TO MID LEVELS IN THE WEST BY MORNING. EXPECT GENERALLY SOUTHERLY WINDS AT 10 KTS OR LESS THROUGH THE PERIOD. JD/81 && .FIRE WEATHER...RELATIVE HUMIDITIES THIS AFTERNOON WILL BE LESS THAN 25 PERCENT FOR MUCH OF THE AFTERNOON. THIS IS SUFFICIENTLY LOW FOR A HIGH FIRE DANGER ACROSS MOST OF CENTRAL ALABAMA. A RED FLAG WARNING WILL BE ISSUED FOR GENERALLY THE EASTERN TWO THIRDS OF CENTRAL ALABAMA. && .BMX WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING 11 AM THROUGH 5 PM FOR THE FOLLOWING COUNTIES... WINSTON-WALKER-BLOUNT-ETOWAH-CALHOUN-CHEROKEE-CLEBURNE-TUSCALOOSA- JEFFERSON-SHELBY-ST. CLAIR-TALLADEGA-CLAY-RANDOLPH-HALE-PERRY-BIBB- CHILTON-COOSA-TALLAPOOS A-CHAMBERS-DALLAS-AUTAUGA-LOWNDES-ELMORE- MONTGOMERY-MACON-BULLOCK-LEE -RUSSELL-PIKE-BARBOUR. && $$ 81/16/81