700 FXUS64 KBMX 062333 AFDBMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BIRMINGHAM AL 633 PM CDT SAT JUL 6 2013 .UPDATE... FOR 00Z AVIATION. && .DISCUSSION... A WET SATURDAY ACROSS THE STATE OF ALABAMA. CURRENT WATER VAPOR IMAGERY INDICATES A CLOSED LOW ACROSS THE MID-MISSISSIPPI VALLEY WITH A SHORTWAVE TROUGH MOVING NORTHWARD OUT OF THE GULF OF MEXICO. THERE IS ALSO AN AREA OF SUBSIDENCE ALONG THE MAIN TROUGH AXIS FURTHER TO THE WEST NEAR THE MISSISSIPPI RIVER AND EXPECT THE MAIN MOISTURE AXIS WILL SHIFT TO THE NORTH AND EAST AS THIS AREA OF SUBSIDENCE ADVANCES EASTWARD. ADDITIONALLY...CENTRAL ALABAMA IS IN THE ENTRANCE REGION OF A 90 KT 300 MB JET WHICH IS PROVIDING THE SYNOPTIC SUPPORT FOR CONTINUED SHOWER AND THUNDERSTORM DEVELOPMENT. PW VALUES ACROSS THE AREA ARE ABOVE 2 INCHES AND ARE NEAR THE 99TH PERCENTILE FOR PW IN EARLY JULY. ALL OF THESE INGREDIENTS HAVE PROVIDED AN EXCELLENT RECIPE FOR HEAVY RAINFALL ACROSS CENTRAL ALABAMA. RADAR TRENDS INDICATE THAT THE MAIN MOISTURE AXIS IN NOW EAST OF THE I-65 CORRIDOR. THIS AXIS SHOULD CONTINUE TO PUSH FURTHER TO THE NORTH AND EAST THROUGHOUT THE EVENING AND OVERNIGHT HOURS AS THE UPPER LEVEL TROUGH LIFTS OFF TO THE NORTHEAST. RADAR RAINFALL ESTIMATES HAVE NOT BEEN OVERLY IMPRESSIVE. HOWEVER...ONE TO THREE INCH AN HOUR ESTIMATED RAINFALL RATES ARE OCCURRING IN THE HEAVIER DOWNPOURS ACROSS SOUTHERN AND EASTERN PORTIONS OF CENTRAL ALABAMA. THESE HEAVIER DOWNPOURS ARE A BIT MORE SCATTERED AND SHOULD REMAIN CONFINED TO AREAS ALONG AND EAST OF A MONTGOMERY TO ANNISTON LINE. HOWEVER...A FLASH FLOOD WATCH CONTINUE FOR ALL OF CENTRAL ALABAMA UNTIL TOMORROW MORNING. RADAR TRENDS WILL HAVE TO BE CAREFULLY MONITORED OVER THE NEXT FEW HOURS TO WATCH FOR TRAINING HEAVY DOWNPOURS. EVEN THOUGH THE MAIN UPPER LEVEL TROUGH WILL LIFT OUT OVERNIGHT TONIGHT...DEEP LAYER MOISTURE WILL REMAIN IN PLACE ACROSS CENTRAL ALABAMA. THE UPPER LEVEL RIDGE WILL FLATTEN BUT CONTINUED SOUTHERLY FLOW AROUND THE BERMUDA HIGH WILL KEEP THE FORECAST AREA IN A TROPICAL LIKE ATMOSPHERE. PW VALUES WILL REMAIN IN THE 2 INCH AREA. THIS WILL KEEP RAIN CHANCES IN THE FORECAST FOR THE START OF THE WEEK. PRECIPITATION CHANCES WILL EVENTUALLY BECOME MORE DIURNALLY DRIVEN THROUGHOUT THE WEEK WITH THE LACK OF ANY SYNOPTIC FEATURE. WENT WELL BELOW GUIDANCE WITH THE HIGH TEMPERATURES THROUGHOUT THE FORECAST WITH ABUNDANT LOW LEVEL AND SOIL MOISTURE TEMPERATURES SHOULD STRUGGLE TO REACH UP INTO THE 90S. THE UPPER LEVEL FLOW WILL BECOME MORE NORTHWESTERLY LATE IN THE WEEK AS A THE RIDGE OVER THE CENTRAL PLAINS AMPLIFIES AND A TROUGH DIGS IN ACROSS THE GREAT LAKES. THIS TROUGH WILL CONTINUE TO DIG IN ACROSS THE EASTERN U.S. THROUGHOUT THE END OF THE WORK WEEK WITH A FRONTAL PASSAGE POSSIBLE BY NEXT WEEKEND. 05/MA && .AVIATION... 00Z TAF DISCUSSION. NUMEROUS LIGHT TO MODERATE SHOWERS WILL CONTINUE THIS EVENING...MAINLY EAST OF I-65...WITH COVERAGE MOST LIKELY DECREASING OVERNIGHT. MODELS HAVE TRIED TO TAKE CIGS DOWN TO IFR/LIFR AT ALL TERMINALS THE PAST COUPLE OF NIGHTS...HOWEVER THIS HASN'T BECOME REALITY. HAVE MADE THE DECISION TO BASE TONIGHT'S CIG FORECAST MORE ON TRENDS FROM THE PAST COUPLE OF NIGHTS RATHER THAN THE MODEL OUTPUT. THEREFORE HAVE KEPT ALL SITES AT MVFR WITH A TEMPO OF IFR BEFORE SUNRISE...WITH THE EXCEPTION OF TOI WHICH HAS BEEN PRONE TO DROPPING TO IFR FOR LENGTHIER PERIODS OF TIME OVERNIGHT. WILL KEEP A CLOSE EYE ON EVENING TRENDS TO SEE IF ADJUSTMENTS FOR THE OVERNIGHT PERIOD ARE NEEDED. OVERALL RAIN COVERAGE SHOULD BE A BIT LESS ON SUNDAY WITH THE HIGHEST RAIN CHANCES ACROSS THE EAST. LOOK FOR MVFR/VFR CIGS THRU THE DAY WITH WINDS OUT OF THE SE AT LESS THAN 10 KTS. 19 && .BMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR ALL OF CENTRAL ALABAMA. && $$