508 FXUS64 KMEG 290516 AFDMEG AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEMPHIS TN 1216 AM CDT FRI MAR 29 2013 .UPDATE... UPDATED FOR 06Z AVIATION DISCUSSION. && .PREV DISCUSSION... /ISSUED 956 PM CDT THU MAR 28 2013/ UPDATE... UPDATED TO SHIFT RAIN CHANCES WEST OVERNIGHT. DISCUSSION... A LOW LEVEL JET STREAK EVIDENT ACROSS THE SOUTHERN PLAINS THIS EVENING WILL SHIFT EASTWARD INTO THE OZARKS LATE TONIGHT WITH INCREASING MOISTURE AND ISENTROPIC ASCENT OVER WESTERN PORTIONS OF THE REGION BEFORE SUNRISE. MAINTAINED CHANCES FOR RAIN MAINLY ACROSS AREAS WEST OF THE MISSISSIPPI RIVER AND ACROSS FAR NORTHERN AREAS WHERE LIFT BECOMES ENHANCED LATE TONIGHT. OTHER THAN MINOR CHANGES TO POPS...THE REMAINDER OF THE FORECAST LOOKS GOOD AND REMAINS UNCHANGED. UPDATED ZONES AND GRIDS HAVE BEEN SENT. JLH && PREV DISCUSSION... /ISSUED 345 PM CDT THU MAR 28 2013/ SURFACE ANALYSIS THIS AFTERNOON PLACES A SURFACE LOW ALONG THE TEXAS PANHANDLE WITH A WARM FRONT EXTENDING NORTHEAST INTO SOUTHEAST KANSAS AND SOUTHERN MISSOURI. VISIBLE SATELLITE TRENDS INDICATE MOSTLY SUNNY SKIES HAVE PREVAILED AT MOST LOCATIONS WITH THE ONLY CLOUD COVER OCCURRING MAINLY ACROSS PORTIONS OF NORTHEAST ARKANSAS...AND THE MISSOURI BOOTHEEL. TEMPERATURES AS OF 3 PM CDT RANGE FROM AROUND 60 DEGREES TO THE LOWER 60S ALONG THE TENNESSEE RIVER AND ACROSS NORTHEAST ARKANSAS AND THE MISSOURI BOOTHEEL. ELSEWHERE...TEMPERATURES ARE IN THE MIDDLE TO UPPER 60S SOUTH OF I-40. SHORT TERM...(TONIGHT THROUGH SUNDAY)...A MID LEVEL DISTURBANCE EMBEDDED WITHIN NORTHWEST FLOW ALOFT WILL MOVE ACROSS THE LOWER MISSISSIPPI VALLEY TONIGHT INTO FRIDAY MORNING. INCREASING ISENTROPIC ASCENT WILL RESULT IN THE DEVELOPMENT OF RAIN SHOWERS TONIGHT...MAINLY ALONG AND WEST OF THE MISSISSIPPI RIVER...AND BETTER CHANCES DURING THE DAY FRIDAY AS THE WARM FRONT BEGINS TO MOVE AS A WEAK COLD FRONT AND THEN QUICKLY BECOMES QUASI- STATIONARY ACROSS THE AREA. THIS WILL RESULT IN SEVERAL CHANCES FOR SHOWERS INTO SATURDAY MORNING AS THE SURFACE BOUNDARY REMAINS NEARLY PARALLEL TO UPPER LEVEL FLOW ALOFT. THE QUASI-STATIONARY BOUNDARY IS EXPECTED TO LIFT BACK NORTH AS A WARM FRONT BY SATURDAY AFTERNOON AND RETURN BACK TO THE MID SOUTH AS COLD FRONT SATURDAY NIGHT INTO SUNDAY. SHORT TERM MODELS INDICATE SOME INSTABILITY WILL BE PRESENT FOR THUNDERSTORMS SATURDAY NIGHT WITH THE BEST CHANCES ON SUNDAY. OVERALL SHEAR AND INSTABILITY IS ANTICIPATED TO REMAIN TOWARDS THE MARGINAL SIDE AND THUS WILL HOLD OFF ON MENTION OF STRONG THUNDERSTORMS IN THE HAZARDOUS WEATHER OUTLOOK. NONETHELESS...WILL CONTINUE TO MONITOR TRENDS IF SUBSEQUENT MODEL RUNS SUGGEST OTHERWISE. TEMPERATURES IN THE SHORT TERM WILL AVERAGE NEAR NORMAL THROUGH THE PERIOD. LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)...12Z GFS/ECMWF LONG TERM MODELS ARE INITIALLY IN GOOD AGREEMENT THROUGH MONDAY NIGHT AS A SECONDARY COLD FRONT MOVES INTO THE LOWER MISSISSIPPI VALLEY. THEREAFTER...THE GFS SUGGESTS THE COLD FRONT WILL BECOME QUASI- STATIONARY AND MOVE BACK ACROSS THE AREA TUESDAY NIGHT INTO TUESDAY WHILE THE ECMWF INDICATES A RIDGE OF HIGH PRESSURE WILL RETURN NEXT TUESDAY AND WEDNESDAY WHILE AN UPPER LEVEL LOW DEVELOPS ACROSS THE SOUTHERN PLAINS BY NEXT THURSDAY. CONSEQUENTLY...CONFIDENCE REMAINS LOW WITH PRECIPITATION CHANCES FOR TUESDAY AND BEYOND AND KEPT CHANCES TO A MINIMUM UNTIL MODELS COME INTO BETTER AGREEMENT. BELOW NORMAL TEMPERATURES ARE ANTICIPATED NEXT WEEK. && .AVIATION... 06Z TAF CYCLE VFR CONDITIONS CONTINUING TONIGHT. RAIN DEVELOPING AND SPREADING ACROSS THE REGION FROM THE NORTHWEST BEGINNING LATE TONIGHT. CONDITIONS LOWERING TO MVFR FROM THE NORTHWEST FRIDAY MORNING. ISOLATED THUNDER MAY ALSO BE POSSIBLE FRIDAY MORNING...HOWEVER THE THREAT IS LOW ENOUGH TO NOT MAKE A MENTION OF IT IN EACH TAF BODY. WINDS TONIGHT SOUTHERLY 5 KTS AT KMEM AND KJBR...VRB03KT AT KTUP AND KMKL. WINDS FRIDAY SOUTHERLY 6-8 KTS. WINDS AFTER 30/00Z E-S ABOUT 4 KTS. JCL/JAB && .PRELIMINARY POINT TEMPS/POPS... MEM 48 64 50 64 / 10 50 50 60 MKL 41 59 45 60 / 10 50 50 50 JBR 47 59 48 60 / 30 70 50 50 TUP 40 63 47 66 / 0 50 50 60 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$