FXUS64 KMRX 031847 AFDMRX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 247 PM EDT FRI MAY 3 2013 .SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)... THE CLOSED LOW OVER THE MS VALLEY WILL REMAIN NEARLY STATIONARY OVER THAT REGION BUT GRADUALLY STRENGTHEN TONIGHT. THIS WILL RESULT IN A 40-50 KT SE FLOW AT 850 MB...WHICH WILL TRANSPORT AN ATLANTIC MOISTURE PLUME INTO THE AREA. MODELS SHOW THAT LIFT IS STRONGLY TIED TO A FRONTOGENESIS ZONE...WHICH MOVES INTO THE SOUTHERN TN VALLEY BY 12Z SAT. THE SURFACE FRONT REMAINS NEARLY STATIONARY FROM THE SW NC CORNER TO AROUND CSV THROUGH SATURDAY NIGHT. MODERATE TO HEAVY PRECIP WILL BE MOVING INTO CHA AROUND THIS TIME. FARTHER NORTH...DOWNSLOPE EFFECTS IN THE LEE OF THE MOUNTAINS WILL GIVE LIGHT QPF AMOUNTS THROUGH SATURDAY...WITH CHANCE POPS ONLY COMING INTO SW VA SATURDAY NIGHT. THE SLOW MOVEMENT OF THE SYSTEM IS A CONCERN FOR FLOODING IN SOUTHERN AND WESTERN AREAS. RAINFALL AMOUNTS THROUGH SATURDAY NIGHT ARE EXPECTED TO BE 2 TO 4 INCHES IN THOSE AREAS. A FLOOD WATCH WILL BE ISSUED FOR SW NC...THE SOUTHERN TN VALLEY...AND CUMBERLAND PLATEAU. .LONG TERM (SUNDAY THROUGH FRIDAY)... NOT MUCH HAS CHANGED FROM THE PREVIOUS LONG TERM DISCUSSION. THE GFS AND ECMWF CONTINUE TO BE IN VERY CLOSE AGREEMENT THROUGHOUT THE EARLY PORTIONS OF THE LONG TERM WITH ONLY SLIGHT DIFFERENCES TOWARD THE END OF THE PERIOD. SUNDAY THROUGH MONDAY OUR WEATHER WILL STILL BE UNDER THE INFLUENCE OF A STUBBORN CUTOFF LOW THAT WILL TAKE ITS TIME TREKKING ACROSS THE STATES JUST TO OUR SOUTH. THE SLOW PROGRESSION IS DUE TO A BLOCKING PATTERN OVER NORTH AMERICA. IT LOOKS LIKE AREAS FROM THE CENTRAL VALLEY AND SOUTH HAVE BETTER CHANCES OF SEEING HIGHER RAINFALL AMOUNTS ON SUNDAY. MEAN FLOW IS IN A SE TO NW ORIENTATION AS WE WILL BE POSITIONED IN THE NORTHWEST QUADRANT OF THE LOW. THIS SHOULD ALLOW THE APPALACHIANS TO PROVIDE SOME WHAT OF A RAIN SHADOW TO AREAS NORTHEAST OF THE CENTRAL VALLEY...THUS LIMITING THE HIGHER RAINFALL AMOUNTS THAT WILL LIKELY BE SEEN FURTHER SOUTH. PRECIP EFFICIENCY LOOKS OKAY FOR THIS EVENT BUT I THINK THE HIGHER AMOUNTS ARE GOING TO BE DUE TO MORE OF A DURATION TYPE CAUSE THAN PRECIP EFFICIENCY. WARM-LAYER CLOUD DEPTHS ARE ROUGHLY 8000 TO 9000FT...WHICH IS WHAT WE WANT FOR HIGH EFFICIENCY...BUT CLIMATOLOGY SUGGEST PWS ARE MARGINAL FOR THIS TIME OF YEAR ALONG WITH A LACKING AMOUNT OF INSTABILITY. SOUNDINGS INDICATE PWS MAXING OUT JUST OVER 1 INCH...WHICH PUTS US AROUND THE 50TH PERCENTILE BASED ON CLIMO. HOWEVER...BECAUSE OF THE SLOW PROGRESSION OF THE SYSTEM...DURATION ALONE SHOULD ALLOW AN ADDITIONAL 1 TO 2 INCHES TO FALL ACROSS AREAS GENERALLY SOUTH OF THE CENTRAL VALLEY ON SUNDAY...ESPECIALLY ACROSS SOUTHWEST NC. I THINK PWS ARE ON THE LOW SIDE BECAUSE THE MOISTURE FETCH IS NOT A PURE SOUTHERLY GULF FETCH. IT IS A ATLANTIC/GULF COMBINATION. DEEP OMEGA AND ROBUST VORTICITY WILL MAINTAIN A STEADY GENERATION OF SHOWERS THROUGH MOST OF THE DAY ON SUNDAY. SHOWERS THEN CONTINUE INTO MONDAY...BUT AMOUNTS AND INTENSITY WILL DECREASE AS THE LOW MOVES FURTHER EAST. A FEW ISOLATED THUNDERSTORMS ARE POSSIBLE ON MONDAY AS 500 J/KG OF CAPE ARE PRESENT IN SOUNDINGS. HIGHER PRESSURE EDGES TOWARD THE SOUTHERN APPALACHIANS TUESDAY INTO WEDNESDAY WITH A DECREASING CHANCE FOR CONVECTION AS FURTHER DRYING CONTINUES. WEDNESDAY THROUGH THE REST OF THE EXTENDED LOOK GENERALLY DRY...EXCEPT FOR A SLIGHT CHANCE OF ISOLATED TERRAIN BASED CONVECTION ON THURSDAY AND FRIDAY. WENT SLIGHTLY BELOW GUIDANCE ON TEMPS THROUGH EARLY PERIODS BECAUSE OF INCREASED CLOUD COVER AND SHOWERS. TEMPS WILL GRADUALLY BEGIN TO WARM BY TUESDAY AND CONTINUE TO WARM THROUGH THE REST OF THE EXTENDED. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 55 60 48 62 49 / 90 100 100 60 80 KNOXVILLE MCGHEE TYSON AIRPORT, TN 53 63 51 62 50 / 50 80 100 80 60 OAK RIDGE, TN 54 61 50 62 49 / 50 80 100 80 60 TRI CITIES AIRPORT, TN 48 64 49 62 48 / 10 20 50 60 60 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...FLOOD WATCH FROM SATURDAY AFTERNOON THROUGH MONDAY MORNING FOR THE FOLLOWING ZONES: CHEROKEE...CLAY. TN...FLOOD WATCH FROM SATURDAY AFTERNOON THROUGH MONDAY MORNING FOR THE FOLLOWING ZONES: LOUDON...MORGAN...NORTHWEST MONROE... ROANE...SCOTT TN...SOUTHEAST MONROE. FLOOD WATCH FROM SATURDAY MORNING THROUGH MONDAY MORNING FOR THE FOLLOWING ZONES: BLEDSOE...BRADLEY...EAST POLK...HAMILTON... MARION...MCMINN...MEIGS...RHEA...SEQUATCHIE...WEST POLK. VA...NONE. && $$ DGS/SR  FXUS64 KMRX 051425 AFDMRX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 1025 AM EDT MON AUG 5 2013 .DISCUSSION... UPPER LEVEL NORTHWEST FLOW AND CONVECTION OVER NORTHEASTERN ARKANSAS AND SOUTHEASTERN MISSOURI HAS BEEN SPILLING THE ASSOCIATED CLOUD COVER ACROSS SOUTHWESTERN PORTIONS OF THE FORECAST AREA THIS MORNING. THERE MAY BE A COUPLE OF HOURS OF SUNSHINE IN CHATTANOOGA BEFORE THICKER CLOUDS FILL IN LATER TODAY. MARION...SEQUATCHIE... BLEDSOE AND EVENTUALLY HAMILTON COUNTIES WILL BECOME MOSTLY CLOUDY. DAYTIME MAX TEMPERATURES WILL BE HIGHLY DEPENDENT ON THE THICKNESS OF THE CLOUDS AND HOW MUCH SUNSHINE IS FILTERED. WAS TEMPTED TO LOWER CHA TEMPS BUT WITH THE UNCERTAINTY OF CLOUD THICKNESS OPTED TO CONTINUE WITH THE UPPER 80S. HOWEVER...DID UPDATE THE SKY GRID TO ACCOUNT FOR HIGHER CLOUD COVER THE REMAINDER OF THE DAY. ALL AREAS SHOULD BE PRECIPITATION FREE TODAY AND OTHER AREA TEMPERATURES LOOK FINE. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 87 67 88 72 88 / 10 10 30 30 60 KNOXVILLE MCGHEE TYSON AIRPORT, TN 85 64 86 70 85 / 10 10 30 30 60 OAK RIDGE, TN 85 64 86 70 85 / 10 10 20 30 60 TRI CITIES AIRPORT, TN 82 61 83 66 81 / 10 10 20 30 60 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ AC  FXUS64 KMRX 071851 AFDMRX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 251 PM EDT WED AUG 7 2013 .SHORT TERM...(TONIGHT THROUGH THURSDAY)...SHOWERS AND STORMS WILL CONTINUE TO DEVELOP THROUGH THE AFTERNOON AND INTO THE EVENING HOURS AS HIGH PWS AND MODEST CAPE WILL MAKE FOR AN UNSTABLE ENVIRONMENT. LATEST NAM SOUNDINGS SHOW PWS RANGING FROM 1.8 TO 2 INCHES WITH ROUGHLY 800 TO 1500 J/KG OF CAPE. AS MENTIONED IN THE MORNING UPDATE...THESE HIGHER PWS PUT US IN THE 75TH TO 90TH PERCENTILE RANGE FOR THIS TIME OF YEAR. WARM LAYER CLOUD DEPTHS WILL CONTINUE TO REMAIN WELL ABOVE 10K FEET THROUGH THE EVENING WHICH IS A CONDUCIVE ENVIRONMENT FOR HEAVY RAINFALL DUE TO THE HIGHER PRECIP EFFICIENCY OF THE WARM RAIN PROCESS. HOWEVER...ONLY LOCALIZED POCKETS OF HEAVY RAINFALL ARE EXPECTED. MODELS INDICATE A DECREASE IN ACTIVITY BY AROUND 03Z BUT ONLY FOR A BRIEF PERIOD. TEMPERATURES WILL REMAIN A FEW DEGREES ABOVE NORMAL TONIGHT AS CLOUD COVER WILL PREVENT GOOD RADIATIONAL COOLING. IT APPEARS THAT SOME CONVECTIVE DEBRIS CLOUD COVER WILL REMAIN THROUGH THE NIGHT BUT SOME AREAS COULD SEE PARTIAL CLEARING WHICH WOULD LEAD TO THE DEVELOPMENT OF PATCHY FOG. AMOUNT OF CLEARING IS UNCERTAIN...BUT DID INCLUDE PATCHY FOG IN ZONES OVERNIGHT. HIGH PWS AND MODEST CAPE VALUES CONTINUE FOR THURSDAY... GIVING WAY TO MORE SHOWERS AND STORMS. MODELS SHOW NEW ACTIVITY BEGINNING TO DEVELOP BETWEEN 12Z AND 15Z ON THURSDAY AND CONTINUING THROUGH THE DAY. THIS NEW ACTIVITY WILL BE IN RESPONSE TO AN APPROACHING COLD FRONT THAT STALLS OUT TO OUR WEST. MAX TEMPS ON THURSDAY WILL BE A DEGREE OR TWO WARMER THAN TODAY. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)...UPPER AIR PATTERN OVER THE FORECAST AREA WILL CONTINUE TO BRING UNSETTLED WEATHER FOR THE NEXT WEEK. THE NORTHERN EXTENT OF THE UPPER RIDGE WILL PLAGUE US THROUGH THE WEEKEND ALONG WITH A PESKY QUASI-STATIONARY FRONTAL BOUNDARY. THE BOUNDARY WILL SERVE AS A FOCI FOR SHOWER AND THUNDERSTORM DEVELOPMENT NEARLY EVERY DAY. ONE ISSUE MAY BECOME HEAVY RAIN ASSOCIATED WITH THE BOUNDARY AND INCREASING PW VALUES. THE CURRENT HAZ WX OUTLOOK COVERS THESE POSSIBILITIES WELL. BY MONDAY A BROAD TROUGH WILL REDEVELOP WITH MORE MCS ACTIVITY FOR SOUTHERN MO AND WESTERN KY. THIS OCCURS EACH DAY THROUGH THE MIDDLE OF NEXT WEEK. LOOKS LIKE A VERY SIMILAR PATTERN TO THE PAST FEW DAYS. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 72 87 72 89 71 / 50 70 30 50 50 KNOXVILLE MCGHEE TYSON AIRPORT, TN 70 85 71 87 69 / 50 60 40 60 50 OAK RIDGE, TN 70 85 71 86 70 / 50 60 40 60 50 TRI CITIES AIRPORT, TN 68 83 67 82 67 / 50 60 40 60 50 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SR/AC  FXUS64 KMRX 080216 AFDMRX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 1015 PM EDT TUE APR 7 2015 .DISCUSSION...WATCHING THE CLUSTER OF SHOWERS AND ISOLATED THUNDERSTORMS TRACKING SE OUT OF ERN KY AT LATE EVENING...WHICH CONTINUE TO WEAKEN JUST UPON ENTERING OUR SW VA COUNTIES. MAY STILL SEE SOME PASSING LIGHT TO MODERATE SHOWERS CLIP SW VA AND NE TN OVER THE NEXT FEW HOURS...SO THE UPDATED GRIDS FROM EARLIER STILL LOOK ON TRACK. AREAS ALONG THE TN-VA STATE LINE DID MEASURE AROUND 2 TO 3 INCHES OF RAIN TODAY...AND A FEW STREAMS HAVE RESPONDED BY RISING TO BANKFULL. THE RFC UPDATED A FEW POINTS ALONG THE CLINCH AND POWELL RIVERS RECENTLY. THE NEW FORECASTS TAKE THE CLINCH RIVER ABOVE TAZEWELL TN TO JUST ABOVE THE ACTION STAGE OF 10 FEET...AND AN FLS WAS ISSUED. OTHERWISE...PLAN TO FRESHEN A FEW GRIDS AND WEB PRODUCTS AROUND 11 PM EDT. && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ TG