AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEMPHIS TN 1005 AM CDT SUN MAY 19 2013 .DISCUSSION... SKIES ARE PARTLY TO MOSTLY SUNNY ACROSS THE FORECAST AREA THIS MORNING WITH TEMPERATURES RANGING FROM THE MID 70S TO LOWER 80S. A FEW SHOWERS MOVED ACROSS PORTIONS OF NORTHWEST TENNESSEE EARLIER THIS MORNING BUT THIS ACTIVITY HAS MOVED INTO MIDDLE TENNESSEE. THE REMAINDER OF THE DAY SHOULD BE DRY WITH TEMPERATURES APPROACHING 90 DEGREES IN SOME AREAS. WILL UPDATE FORECAST TO REMOVE MENTION OF POPS FOR TODAY. ARS && .PREV DISCUSSION... /ISSUED 649 AM CDT SUN MAY 19 2013/ AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE MID SOUTH TODAY. RESIDUAL TROUGHING OVER EASTERN SECTIONS OF THE MID SOUTH THIS MORNING MAY CONTINUE TO SUPPORT ISOLATED SHOWERS AND THUNDERSTORMS THIS MORNING ACROSS WEST TENNESSEE AND FAR NORTHEAST MISSISSIPPI IN THE VICINITY OF THE TENNESSEE RIVER. THIS ACTIVITY SHOULD DIMINISH LATER THIS MORNING AS THE UPPER RIDGING BUILDS EAST AND SUPPRESSES CONVECTION. MORNING CLOUD COVER WILL LIKELY GIVE WAY TO MOSTLY SUNNY SKIES THIS AFTERNOON. TEMPERATURES SHOULD RISE INTO THE UPPER 80S TO AROUND 90 DEGREES ALONG WITH CONTINUED SEASONABLY HIGH DEWPOINTS IN THE UPPER 60S TO AROUND 70 DEGREES. THIS WILL RESULT IN AFTERNOON HEAT INDEX VALUES RISING WELL INTO THE 90S. THE UPPER RIDGE WILL CONTINUE TO MOVE EAST OVER THE NEXT FEW DAYS BUT SHOULD KEEP MAINLY DRY WEATHER IN PLACE OVER THE MID SOUTH ALONG WITH VERY WARM AND HUMID CONDITIONS THROUGH MONDAY. A POTENT UPPER LEVEL LOW PRESSURE SYSTEM CURRENTLY OVER THE CENTRAL ROCKIES WILL LIFT SLOWLY NORTHEAST INTO THE NORTHERN PLAINS THROUGH EARLY NEXT WEEK. A SERIES OF SHORTWAVE DISTURBANCES WILL SWING AROUND THE SOUTHERN PERIPHERY OF THE UPPER LOW. THE FIRST IN A SERIES OF SHORTWAVES WILL LIFT NORTHEAST ACROSS THE SOUTHERN PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY LATER TODAY INTO TONIGHT. THIS WILL RESULT IN SHOWERS AND THUNDERSTORMS DEVELOPING OVER THE CENTRAL AND SOUTHERN PLAINS WHICH WILL LIFT INTO THE MIDDLE MISSISSIPPI VALLEY TONIGHT. THIS ACTIVITY IS EXPECTED TO REMAIN NORTH AND WEST OF THE FORECAST AREA THROUGH MONDAY. A SECOND SHORTWAVE WILL LIKELY FOLLOW A SIMILAR TRAJECTORY LATE MONDAY AND MONDAY NIGHT. THUNDERSTORMS WILL AGAIN DEVELOP OVER THE SOUTHERN PLAINS MONDAY AFTERNOON AND EVENING...LIFTING NORTHEAST TOWARDS THE MIDDLE MISSISSIPPI VALLEY MONDAY NIGHT. FAR NORTHWEST PORTIONS OF THE MID SOUTH MAY BE GRAZED BY THE ACTIVITY LATE MONDAY NIGHT BEFORE LIFTING TO THE NORTH. PLAN TO CARRY CHANCE POPS OVER PORTIONS OF NORTHEAST ARKANSAS AND THE MISSOURI BOOTHEEL AFTER MIDNIGHT MONDAY INTO EARLY TUESDAY MORNING. A THIRD AND STRONGER SHORTWAVE IS EXPECTED TO EJECT FROM THE SOUTHERN PLAINS AND ACROSS THE MID SOUTH TUESDAY NIGHT INTO WEDNESDAY. LATEST MODEL GUIDANCE SUGGESTS THAT THIS SHORTWAVE WILL TAKE ON AN INCREASINGLY NEGATIVE TILT AS IT MOVES INTO THE FORECAST AREA. INSTABILITY AND SHEAR SHOULD STRENGTHEN IN ADVANCE OF THIS FEATURE AS THE SHORTWAVE OVERSPREADS A WARM AND HUMID AIRMASS IN PLACE OVER THE REGION. THIS SHOULD RESULT IN THE DEVELOPMENT OF NUMEROUS SHOWERS AND THUNDERSTORMS OVER WESTERN AREAS BY TUESDAY EVENING THAT SHOULD SPREAD NORTHEASTWARD ACROSS THE REMAINDER OF THE FORECAST AREA THROUGH WEDNESDAY. THE DEGREE OF SHEAR AND INSTABILITY EXPECTED APPEARS FAVORABLE TO SUPPORT THE POTENTIAL FOR SEVERE THUNDERSTORMS. IT STILL REMAINS TOO EARLY TO PROVIDE SPECIFIC DETAILS ON EVENTUAL THREATS AND MAGNITUDE OF THE SEVERE EVENT. STAY TUNED TO THE LATEST FORECAST OVER THE NEXT COUPLE OF DAYS AS THIS POTENTIAL SEVERE WEATHER EVENT UNFOLDS. THE SHORTWAVE SHOULD LIFT NORTHEAST OF THE FORECAST AREA WEDNESDAY NIGHT LEAVING BROAD TROUGHING IN PLACE OVER THE REGION INTO THURSDAY AS THE UPPER LOW TO THE NORTH MOVES EAST INTO THE GREAT LAKES REGION AND ATTEMPS TO PHASE WITH SHORTWAVE ENERGY DROPPING SOUTH THROUGH EASTERN CANADA. WARM AND HUMID CONDITIONS SHOULD PERSIST INTO THURSDAY WITH SCATTERED SHOWERS AND THUNDERSTORMS CONTINUING ACROSS THE AREA. THE PHASING SYSTEMS OVER THE NORTHEAST U.S. SHOULD HELP TO CARVE OUT A DEEPER UPPER TROUGH OVER THE EASTERN SEABOARD FRIDAY INTO NEXT WEEKEND. THIS SHOULD HELP TO FORCE A COLD FRONT ACROSS THE MID SOUTH ON FRIDAY WITH HIGH PRESSURE BUILDING SOUTH. THIS SHOULD ALLOW FOR A RETURN TO DRY WEATHER BY NEXT WEEKEND ALONG WITH SLIGHTLY COOLER AND LESS HUMID CONDITIONS. JLH && .AVIATION... 12Z TAF CYCLE TEMPORARY MVFR CONDITIONS EXPECTED AT MKL/JBR/TUP THROUGH 19/14Z DUE TO REDUCED VISIBILITIES. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH MOST OF THE PERIOD AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE AREA TODAY AND TONIGHT. CONFIDENCE FOR LOW STRATUS LATE TONIGHT IS LOW AND LEFT OUT MENTION IN FORECAST AT MKL/JBR/TUP FOR NOW. SOUTH WINDS WILL INCREASE TODAY TO BETWEEN 10-15 KTS SUSTAINED WITH GUSTS BETWEEN 18-25 KTS...ESPECIALLY AT MEM/JBR. SOUTH WINDS WILL DECREASE TO 5-8 KTS AT MKL/TUP AND BETWEEN 9-11 KTS AT MEM/JBR AFTER 20/00Z. && .PRELIMINARY POINT TEMPS/POPS... MEM 89 73 90 72 / 10 10 10 10 MKL 88 69 89 70 / 10 10 10 10 JBR 89 71 88 70 / 10 10 10 20 TUP 88 69 89 68 / 10 10 0 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$