513 FXUS64 KMEG 281517 AFDMEG AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEMPHIS TN 1017 AM CDT FRI MAR 28 2014 .DISCUSSION... SKIES ARE PARTLY TO MOSTLY CLOUDY ACROSS THE FORECAST AREA THIS MORNING WITH TEMPERATURES RANGING FROM THE UPPER 50S TO MID 60S. COLD FRONT IS SLOWLY MOVING SOUTH ACROSS NORTHERN SECTIONS OF THE FORECAST AREA. THERE IS NO PRECIPITATION OVER ANY PART OF THE FORECAST AREA AT THIS TIME BUT MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON. THERE IS STILL A SLIGHT RISK OF SEVERE THUNDERSTORMS FORMING NEAR AND SOUTH OF THE COLD FRONT. WILL UPDATE THE FORECAST TO REMOVE MORNING WORDING BUT NO BIG CHANGES ARE NEEDED AT THIS TIME. ARS && .PREV DISCUSSION... /ISSUED 655 AM CDT FRI MAR 28 2014/ DISCUSSION... AN UPPER LEVEL SHORTWAVE CONTINUES TO MOVE EAST ACROSS THE MIDDLE MISSISSIPPI VALLEY EARLY THIS MORNING AS A SURFACE COLD FRONT SAGS SOUTHEASTWARD ACROSS NORTHERN ARKANSAS AND SOUTHEASTERN MISSOURI. THE AIR MASS SOUTH OF THE FRONT ACROSS THE MID SOUTH REMAINS WARM AND INCREASINGLY MOIST. SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE ACROSS THE AREA EARLY THIS MORNING IN RESPONSE TO WEAK FORCING ALONG THE SOUTHERN PERIPHERY OF THE SHORTWAVE TO THE NORTH. AS THIS SHORTWAVE MOVES EAST LATER THIS MORNING...EXPECT COVERAGE OF SHOWERS AND THUNDERSTORMS TO WANE FOR A PERIOD. THE SURFACE FRONT SHOULD PROGRESS SOUTHEASTWARD INTO PORTIONS OF NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...AND NORTHWEST TENNESSEE BEFORE STALLING AS THE INITIAL SHORTWAVE DEPARTS AND THE UPPER FLOW BECOMES PARALLEL TO THE FRONT. AREAS NORTH OF THE FRONT SHOULD EXPERIENCE COOLER TEMPERATURES AND A NOTICEABLE DROP IN HUMIDITY LEVELS. ACROSS THE REMAINDER OF THE AREA TO THE SOUTH OF THE STALLING FRONT...TEMPERATURES SHOULD CONTINUE TO WARM FROM MID MORNING THROUGH THE EARLY AFTERNOON HOURS. DEWPOINTS SHOULD ALSO CONTINUE TO SLOWLY RISE INTO THE LOWER 60S SOUTH OF THE FRONT. BY LATER THIS AFTERNOON...A SECONDARY MID AND UPPER LEVEL SHORTWAVE TROUGH CURRENTLY ACROSS THE SOUTHWESTERN HIGH PLAINS WILL MOVE EAST AND INCREASE LARGE SCALE LIFT ACROSS WESTERN PORTIONS OF THE MID SOUTH. THE ATMOSPHERE WILL CONTINUE TO DESTABILIZE INTO THE AFTERNOON MAINLY ALONG AND SOUTH OF INTERSTATE 40. ACROSS AREAS NEAR THE INTERSTATE 40 CORRIDOR...SBCAPES SHOULD INCREASE TO AROUND 1000 J/KG...WITH LI/S BETWEEN -2C AND -4C...AND MID LEVEL LAPSE RATES AROUND 7.0 C/KM. FURTHER SOUTH ACROSS EASTERN ARKANSAS AND MUCH OF NORTH MISSISSIPPI...EVEN GREATER INSTABILITY SHOULD DEVELOP WITH SBCAPES RANGING FROM 1500-2000 J/KG...LI/S BETWEEN -4C AND -6C...AND MID LEVEL LAPSE RATES AROUND 7.0 C/KM. AS THE SHORTWAVE APPROACHES...MUCH OF THE AVAILABLE MODEL GUIDANCE SUGGESTS THAT A WEAK SURFACE WAVE WILL DEVELOP AND LIFT NORTHEAST ALONG THE STALLED FRONT. INCREASED LARGE SCALE ASCENT IN ASSOCIATION WITH THE SHORTWAVE...ENHANCED LOW LEVEL FORCING IN ADVANCE OF THE SURFACE LOW TRACK...AND MODERATE INSTABILITY SHOULD ALLOW NUMEROUS SHOWERS AND THUNDERSTORMS TO DEVELOP THIS AFTERNOON ACROSS WESTERN AREAS AND LIFT NORTHEAST ACROSS THE MID SOUTH THIS EVENING. STRONG MID LEVEL FLOW AROUND 50 KTS WILL COMBINE WITH THE AVAILABLE INSTABILITY TO ALLOW FOR A FEW SEVERE STORMS CAPABLE OF MAINLY DAMAGING WINDS AND LARGE HAIL. AN ISOLATED TORNADO CANNOT BE RULED OUT NEAR AND SOUTHEAST OF THE SURFACE LOW...BUT RELATIVELY WEAK LOW LEVEL FLOW SHOULD TEND TO SUPPRESS THE OVERALL TORNADO THREAT. THIS SEVERE WEATHER THREAT SHOULD REMAIN PRIMARILY ALONG AND SOUTH OF INTERSTATE 40 FROM THIS AFTERNOON THROUGH THIS EVENING. AS THE SURFACE LOW LIFTS NORTHEAST AND THE SHORTWAVE MOVES EAST IT WILL HELP TO DRAG THE INITIALLY STALLED FRONT THROUGH AS A COLD FRONT LATE TONIGHT. SHOWERS AND THUNDERSTORMS SHOULD END IN MOST AREAS BY SUNRISE SATURDAY MORNING WITH SKIES CLEARING FROM WEST TO EAST THROUGH THE MORNING HOURS. HIGH PRESSURE WILL BUILD OVER THE REGION ON SATURDAY AND SLOWLY MOVE EAST ACROSS THE AREA THROUGH MONDAY. TEMPERATURES SHOULD INITIALLY REMAIN RATHER COOL BEHIND THE FRONT SATURDAY WITH HIGHS REMAINING 5-10 DEGREES BELOW SEASONAL NORMALS. BY LATE IN THE WEEKEND...AS THE HIGH SHIFTS EAST EXPECT A RETURN TO LOW LEVEL SOUTHERLY FLOW AND TEMPERATURES WARMING EAST DAY...INTO THE MID AND UPPER 60S SUNDAY...AND LOWER TO MIDDLE 70S MONDAY. AN UPPER LEVEL SHORTWAVE WILL LIFT NORTHEAST ACROSS THE UPPER MISSISSIPPI VALLEY BY MONDAY NIGHT AND INTO THE GREAT LAKES ON TUESDAY. THIS SYSTEM WILL HELP TO PUSH ANOTHER WEAKENING COLD FRONT TOWARDS THE AREA BY TUESDAY. THIS FRONT SHOULD WASH OUT PRIOR TO REACHING THE FORECAST AREA...THEREFORE ONLY EXPECTING INCREASED CLOUD COVER AND LITTLE CHANGE IN TEMPERATURES THROUGH WEDNESDAY MORNING. HIGH TEMPERATURES TUESDAY WILL AGAIN REACH INTO THE 70S WITH LOWS IN THE 50S. A STRONGER UPPER LEVEL SHORTWAVE WILL APPROACH THE AREA FROM THE WEST ON WEDNESDAY AND THURSDAY. A WARM AND MOIST AIR MASS SHOULD EXIST ACROSS THE MID SOUTH WITH INCREASING CHANCES FOR ADDITIONAL SHOWERS AND THUNDERSTORMS DURING THIS TIME PERIOD. TEMPERATURES SHOULD REMAIN WARM THROUGH THE END OF NEXT WEEK UNTIL ANOTHER COLD FRONT MOVES THROUGH LATE NEXT WEEK BRINGING SLIGHTLY COOLER CONDITIONS AND A RETURN TO DRY WEATHER CONDITIONS. JLH && .AVIATION... 12Z TAF CYCLE MAINLY MVFR/IFR CONDITIONS PERSIST AT TAF SITES THIS MORNING. A GRADUAL IMPROVEMENT TO VFR CONDITIONS BY THIS AFTERNOON IS EXPECTED. A COLD FRONT IS EXPECTED TO BECOME NEARLY STATIONARY ACROSS THE AREA TODAY WITH A SURFACE LOW MOVING FROM NORTHEAST TEXAS INTO THE REGION LATER THIS AFTERNOON INTO TONIGHT. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO RE-DEVELOP AT MEM/JBR AFTER 28/22Z WITH BETTER COVERAGE FROM EARLY TO MID EVENING...THEN SPREADING TO AFFECT MKL AND TUP FROM LATE EVENING INTO THE EARLY OVERNIGHT HOURS. THESE SHOWERS AND THUNDERSTORMS ARE ANTICIPATED TO BRING A RETURN OF MVFR/IFR CONDITIONS BACK TO THE AREA TONIGHT. SOUTH WINDS BETWEEN 6-8 KTS TODAY AT MEM/MKL/TUP AND EAST/NORTHEAST WINDS AT JBR WILL GRADUALLY VEER NORTHWEST WITH PASSAGE OF THE SURFACE LOW AND ASSOCIATED COLD FRONT TONIGHT. CJC && .PRELIMINARY POINT TEMPS/POPS... MEM 73 51 62 43 / 70 90 10 0 MKL 71 50 60 36 / 50 90 10 0 JBR 67 45 61 38 / 80 90 10 0 TUP 74 57 64 40 / 50 90 10 0 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$