| ALL RIGHT...THE PART OF THE FORECAST EVERYONE WANTS TO KNOW ABOUT. IS IT GOING TO RAIN THIS WEEKEND OR NOT? IF YOU LIVE CLOSER TO THE COAST...YOU WILL HAVE BETTER CHANCES OF SEEING AT LEAST A FEW DROPS. CONFIDENCE IN THIS FORECAST IS VERY LOW TO SAY THE LEAST. FIRST...TROPICAL WAVE IN THE NW CARIBBEAN IS NOT ALL THAT ORGANIZED AND LOOKS TO POSSIBLY MOVE OVER THE YUCATAN PENINSULA. HARD TO KNOW WHAT WILL REMAIN OF THE WAVE ONCE IT EMERGES INTO THE GULF SOMETIME TOMORROW. THE WAVE IS NOT ALL THAT WELL DEFINED BUT UPPER LEVEL WINDS MAY BE A LITTLE MORE FAVORABLE FOR DEVELOPMENT EXCEPT FOR SOME WESTERLY SHEAR ACROSS THE NORTHERN GULF WHERE THERE IS A WEAK UPPER LEVEL LOW. SAID ALL OF THIS TO SAY THAT THE SYSTEM MAY BE SLOW TO DEVELOP AND LARGELY DEPEND ON WHERE IT CAN DEVELOP A CORE OF CONVECTION. SECOND...SINCE THE SYSTEM IS ILL-DEFINED...NONE OF THE MODELS REALLY HAVE A GOOD GRIP ON HOW TO INITIALIZE IT OR HOW TO HANDLE ITS EVOLUTION ONCE SOMETHING DOES FORM. THE NAM HAS BEEN THE MOST CONSISTENT WITH DEVELOPING AT LEAST A TROPICAL CYCLONE OF SOME SHAPE AND DEEPENING IT OFF THE LA COAST FRI. THINK IT WEAKENS THE RIDGE TOO MUCH WHICH WILL STRETCH FROM THE S ROCKIES TO THE MISS RIVER VALLEY. THE GFS AND ECMWF SOLUTIONS MINDS AS WELL BE POLAR OPPOSITES WITH THEIR SOLUTIONS. GFS HAS A BROAD WEAK LOW ALONG THE LA COAST AND MOVES IT EAST WITH TIME AND THEN UP THE EAST COAST EARLY NEXT WEEK. THE ECMWF HAS A WEAK LOW FRI/SAT AND THEN DEEPENS IT OFF THE LOWER TX COAST SUN. THE SYSTEM REMAINS IN THE W GULF THROUGH MID OF NEXT WEEK BEFORE TURNING N INTO SE TX. NEITHER OF THESE SOLUTIONS LOOK VERY REASONABLE AT THIS POINT. THE SREF AND GFS ENSEMBLE MEAN PROBABLY OFFER AT LEAST SOME GUIDANCE. THE SREF LIKE THE NAM DEVELOPS A LOW OFF THE LA COAST BY FRI BUT IS MUCH WEAKER. SAME CAN BE SAID FOR THE GFS ENSEMBLE. SREF DOES LOOK TO MOVE THE SYSTEM BACK TO THE WEST SOME LIKE THE NAM AS WELL. THE MAIN TRICK WILL BE TO SEE IF A STRONG SHORTWAVE TROUGH OVER THE NORTHERN TIER OF STATES WILL BE ABLE TO PICK UP THE SYSTEM SUN/MON WITH THE UPPER RIDGE OVER THE S ROCKIES AND WEAKENING OVER THE MISS RIVER VALLEY. THIS MAY OPEN UP ENOUGH FOR THE SYSTEM TO PULL INLAND SUN/MON. ADD TOO THAT THAT THE EXTENDED MODELS BRING A FRONT INTO THE REGION MON...THIS TOO MAY GIVE REASON FOR THE SYSTEM TO PUSH INLAND IN THE SUN/MON TIME FRAME. SO UNTIL THE MODELS COME IN TO MORE AGREEMENT ON THE DETAILS...BEST COURSE SEEMS TO BE TO GO WITH PARTS OF MODEL SOLUTIONS THAT MAKE THE MOST PHYSICAL SENSE WHICH REALLY IS NOT MUCH. ALIGNED POPS FOR THE REST OF THE WEEK AND WEEKEND KEEPING IN MIND LOTS OF UNCERTAINTY BUT THAT THERE WILL BE SOME TROPICAL DEVELOPMENT IN THE N GULF FRI. SYSTEM LINGERS IN THE N/NW GULF THROUGH SUN WHEN STRONG SHORTWAVE ACROSS THE NORTH BEGINS TO PULL IT INLAND SUN/MON. FRONTAL BOUNDARY THEN PUSHES INTO THE REGION MON/TUE WHICH CLEARS EVERYTHING OUT AND MAY ACTUALLY BRING TEMPS DOWN TO CLIMO NORMS WHICH WILL BE ABOUT 10-15 DEGREES COOLER THAN TEMPS FROM THIS PAST WEEK. AGAIN...WILL REALLY HAVE TO WATCH THIS SYSTEM BECAUSE QUITE POSSIBLE FOR THERE TO BE RAINBANDS TO AFFECT THE AREA WHICH COULD BRING VERY HEAVY RAINFALL. STRONG EAST WINDS THAT DEVELOP WOULD ALSO BUILD UP SEAS AND COASTAL FLOODING THREAT. WHILE SE TX COULD USE THE RAINFALL...STILL LOTS OF OTHER IMPACTS THAT WILL DEPEND ON THE DETAILS IN THE FORECAST WHICH UNFORTUNATELY ARE SKETCHY AT BEST. GIVEN THE UNCERTAINTY AND THE POSSIBILITY OF EXTREME IMPACTS TO THE AREA...BEST TO MONITOR FORECAST TRENDS CLOSELY. |