Tuesday, March 23, 2010

Tuesday Morning Forecast discussion

.DISCUSSION...  THE LARGE SCALE PATTERN WILL CONTINUE TO FEATURE A LONG WAVE TROUGH ACROSS EASTERN NORTH AMERICA...WITH A RIDGE NEAR OR SLIGHTLY INLAND OF THE WEST COAST. A GENERAL NORTHWEST FLOW WILL THEREFORE PERSIST ACROSS THE CENTRAL UNITED STATES. NO STRONG BLOCKING SIGNALS NOTED INITIALLY...SO UPPER LEVEL ENERGY SHOULD BE FAIRLY PROGRESSIVE IN NATURE. LONG WAVE CHARTS DO INDICATE SLIGHT AMPLIFICATION AS WE GET INTO EARLY NEXT WEEK...SO PROGRESSION MAY TEND TO SLOW DOWN. FORECAST CONCERNS INCLUDE TEMPERATURES IN THE SHORT TERM...WITH MELTING SNOW PACK PLAYING A BIG ROLE. ATTENTION THEN TURNS TO A PAIR OF STORM SYSTEMS...ONE FOR MIDWEEK AND ONE FOR THE UPCOMING WEEKEND.  FIRST THINGS FIRST...WILL KEEP PATCHY FOG IN THE FORECAST FOR EARLY THIS MORNING. HAS NOT MATERIALIZED YET...ALTHOUGH VISIBILITIES ARE STARTING TO COME DOWN ACROSS SOUTHEAST MISSOURI. AS WE SAW ON MONDAY...THE SNOW PACK PLAYED A HUGE ROLE WITH TEMPERATURES. THERE WAS A CONSIDERABLE AMOUNT OF MELTING...BUT SNOW REMAINS ACROSS THE OSAGE PLAINS REGION OF SOUTHEAST KANSAS AND WESTERN MISSOURI. WITH A SHORT WAVE RIDGE SLIDING OVERHEAD TODAY...925 MB TEMPERATURES ARE PROGGED TO WARM INTO THE LOWER TEENS CELSIUS. WITH NEAR FULL SUNSHINE...THIS SHOULD RESULT IN UPPER 60 TO NEAR 70 DEGREE HIGHS WHERE THERE IS NO SNOW. AREAS WITH SNOW PACK SHOULD STILL MANAGE TO MAKE THE LOWER OR MIDDLE 60S. DOUBT WE WILL HAVE ANY SNOW LEFT AFTER TODAY. THEN WENT ON THE HIGH SIDE OF GUIDANCE FOR TEMPERATURES TONIGHT AS WEAK LOW LEVEL SOUTHERLY FLOW PERSISTS AND HIGH CLOUDS INCREASE. MIDDLE AND PERHAPS A FEW UPPER 40S LOOK REASONABLE.  UPPER LEVEL ENERGY WILL THEN TRACK ACROSS THE REGION FOR THE MIDWEEK PERIOD. THERE IS STILL UNCERTAINTY REGARDING THE EXACT TRACK OF THE UPPER LEVEL FEATURE. THIS WILL ALSO HAVE IMPACTS ON WHERE A LOW LEVEL BAROCLINIC ZONE SETS UP...AS WELL AS A SURFACE LOW. CURRENT THINKING IS THAT A WARM FRONT WILL TAKE SHAPE FROM SOUTHWEST OKLAHOMA INTO CENTRAL MISSOURI TUESDAY NIGHT AND WEDNESDAY. NOT OUT OF THE QUESTION WE COULD SEE A FEW SHOWERS DEVELOP TO THE NORTH OF THE FRONT...BUT THINK THE MAJORITY OF THIS ACTIVITY WILL REMAIN ACROSS EASTERN KANSAS AND NORTHERN MISSOURI. THE BETTER CHANCE FOR RAIN COMES LATER WEDNESDAY INTO THURSDAY. DID INTRODUCE A SLIGHT CHANCE FOR THUNDER ON THURSDAY ACROSS SOUTH CENTRAL MISSOURI. WITH THE TRACK OF THE LOW STILL UNCERTAIN...QPF AMOUNTS ALSO REMAIN IN QUESTION. ONCE WE GET A BETTER FEEL FOR THIS...THE WET ANTECEDENT CONDITIONS MAY WARRANT THE CONSIDERATION OF A FLOOD WATCH. AS OF RIGHT NOW...IT LOOKS LIKE AROUND AN INCH OF RAINFALL IS PLAUSIBLE.  ONCE THIS SYSTEM CLEARS THE AREA...WE MAY HAVE TO DEAL WITH A PERIOD OF LOW CLOUDS. THEREFORE KEPT DIURNAL TEMPERATURE RANGES DOWN TO END THE WORK WEEK. AS FOR THE WEEKEND...MEDIUM RANGE MODELS HAVE COME IN SLIGHTLY FASTER WITH THE APPROACH OF THE NEXT WAVE OF ENERGY. THIS IS ALSO SUPPORTED BY SEVERAL ENSEMBLE MEMBERS. HAVE THEREFORE INCREASED POPS INTO THE SLIGHT CHANCE TO CHANCE RANGE FOR SATURDAY. SOME THUNDER WILL ALSO BE POSSIBLE...BUT AGAIN THIS WILL BE DEPENDENT ON THE TRACK OF THE SYSTEM. WITH PROGRESSION BEGINNING TO SLOW...IT IS A TOUGH CALL AS TO WHEN THIS SYSTEM WILL CLEAR THE AREA. IT IS QUITE POSSIBLE THAT CLOUDS AND PERHAPS A FEW SHOWERS COULD LINGER INTO SUNDAY.