848 FXUS62 KRAH 191838 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 238 PM EDT MON AUG 19 2013 .SYNOPSIS... A STALLED FRONTAL ZONE NEAR THE SOUTH CAROLINA BORDER WILL WEAKEN AND EVENTUALLY DISSIPATE THIS AFTERNOON AND TONIGHT. BERMUDA HIGH PRESSURE WILL RESULT IN A SEASONABLY MOIST SOUTHERLY RETURN FLOW THROUGH MID TO LATE WEEK. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 140 PM MONDAY... TODAY: SHORTWAVE TROUGH THAT EXTENDS FROM THE LOWER GREAT LAKES SOUTHWARD INTO THE TN VALLEY WILL SHEAR WITH TIME AS IT PROGRESSES EASTWARD ACROSS THE MID-ATLANTIC STATES. SMALL AMPLITUDE SHORTWAVE ENERGY EMBEDDED IN THE DEEP SWLY FLOW ALOFT AND WITHIN THE RIGHT ENTRANCE REGION OF AN 80-90KT UPPER JET CENTERED OVER THE SPINE OF THE CENTRAL APPALACHIANS IS SUPPORTING WIDESPREAD LIGHT RAIN ACROSS THE CAROLINAS...WITH A SMALL BAND OF WAA CONVEYOR CONVECTIVE SHOWERS ACROSS THE SOUTHERN PIEDMONT--SANDHILLS--AND SOUTHERN COASTAL PLAIN COUNTIES IN PROXIMITY TO A STALLED FRONTAL ZONE IMMEDIATELY ALONG THE SOUTHEAST COAST. WHILE THERE MAY BE A BRIEF BREAK FROM THE RAIN AND SHOWERS AFTER THE FIRST BATCH MOVES THROUGH LATER THIS MORNING/EARLY AFTERNOON...ANOTHER WAVE AND NEXT BATCH OF PRECIP CURRENTLY MOVING THROUGH CHARLOTTE THERE WILL PASS THROUGH THE AREA THIS AFTERNOON AND INTO THE EARLY EVENING. OVER THE PAST FEW HOURS...EARTH NETWORKS TOTAL LIGHTNING DETECTION DATA HAS NOT DETECTED ANY STRIKES ACROSS THE SOUTHERN CWA...WITH MUCAPE OF ONLY AROUND 250 J/KG ACROSS THE EXTREME SOUTHEASTERN ZONES. THE RAIN-COOLED AIR AND NELY WINDS WILL KEEP THE STABLE AIR FIRMLY ENTRENCHED OVER THE AREA...WITH PERHAPS A RUMBLE OF ELEVATED THUNDER ACROSS SAMPSON/WAYNE COUNTY. OUTSIDE OF SOME VERY LOCALIZED HEAVY RAINFALL...DO NOT ANTICIPATE ANY SEVERE WEATHER AT THIS TIME. GIVEN WIDESPREAD PRECIP AND LOW CLOUDS...EXPECT NEAR STEADY TEMPERATURES IN THE LOWER TO MID 70S THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY EVENING. TONIGHT: FORCING IS EXPECTED TO WEAKEN THIS EVENING AND TONIGHT AS THE SHEARED UPPER TROUGH MOVES OFF THE MID-ATLANTIC COAST. A CHANCE OF SPRINKLES/DRIZZLE OR ISOLD SHOWER ACTIVITY MAY PERSIST OVERNIGHT DUE TO A CONTINUED MOIST AIRMASS AND WEAK WARM ADVECTION...THOUGH CHANCES/COVERAGE WOULD BE MUCH LESS THAN TODAY. ADDITIONALLY...FOG IS LIKELY TO DEVELOP ALONG THE DISSIPATING SFC BOUNDARY WITH INLAND ADVECTION OF SFC DEWPOINTS INTO THE UPPER 60S-LOWER 70S EXPECTED. LOWS TONIGHT RANGING FROM THE MID-UPPER 60S N/NW TO LOWER 70S S/SE. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... AS OF 223 PM MONDAY... NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE CAROLINAS ON TUESDAY IN AN AXIS OF 2.0" PWATS RESIDING OVER THE AREA...THAT LIES IN A ZONE OF LOW TO MID-LEVEL MOISTURE CONFLUENCE BETWEEN THE SHORTWAVE TROUGH MOVING INTO THE OHIO/TN VALLEY AND THE SUBTROPICAL HIGH BUILDING IN FROM THE WESTERN ATLANTIC. WHILE STRONGER INSOLATION WILL FINALLY YIELD SOME WEAK TO MODERATE DESTABILIZATION...WEAK BULK SHEAR OF 20KTS OR LESS WILL LIMIT THE SEVERE THREAT...WITH HEAVY RAIN AND LOCALIZED FLOODING THE PRIMARY CONCERN. CONVECTION SHOULD BE LARGELY DIURNALLY DRIVEN...BUT CONTINUED WEAK SOUTHERLY WAA ALONG WITH THE POSSIBILITY FOR ADDITIONAL S/W IMPULSES TO MOVE THROUGH THE AREA ON THE CYCLONIC SIDE OF THE SHORTWAVE TROUGH WILL SUPPORT SLIGHT TO SMALL CHANCE POPS OVERNIGHT. HIGHS IN THE LOWER 80S NW TO MID 80S SE. LOWS IN THE UPPER 60S TO LOWER 70S. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... AS OF 235 PM MONDAY... OVERALL...THE SYNOPTIC PATTERN DURING THE LONG TERM PERIOD WILL SHOWCASE THE BERMUDA RIDGE TO OUR SOUTH AND EAST AND ANOTHER BUILDING RIDGE OVER THE CENTRAL US. OVER OUR REGION...A SHORT WAVE TROUGH WILL SLOWLY DRIFT (AS IT BECOMES SANDWICHED BETWEEN THE TWO AFOREMENTIONED RIDGES) TOWARDS THE MID ATLANTIC WEDNESDAY INTO THURSDAY. THIS SHOULD RESULT IN CONTINUED ABOVE NORMAL CHANCES OF PRECIP...ESPECIALLY ON THURSDAY AS A SURFACE FRONT IS ALSO PROGGED TO IMPACT THE AREA. THE SHORT WAVE TROUGH IS PROGGED TO BE EAST OF THE AREA ON FRIDAY...WITH THE RIDGE OVER THE CENTRAL US STARTING TO BUILD EAST TOWARDS OUR REGION. THIS...ALONG WITH SLIGHTLY LOWER DEEP LAYER MOISTURE THAT IS PROGGED TO FILTER IN BEHIND THE WEAK SURFACE BOUNDARY...SHOULD RESULT IN DECREASING PRECIP CHANCES...ALTHOUGH ISOLATED TO SCATTERED DIURNAL SHOWERS/STORMS WILL STILL BE POSSIBLE EACH AFTERNOON/EVENING. TEMPS WILL GENERALLY BE IN THE MID/UPPER 80S THROUGHOUT THE PERIOD...MAYBE SLIGHTLY WARMER OVER THE WEEKEND AND INTO EARLY NEXT WEEK IF THE RIDGE BUILDS FAR ENOUGH TO THE EAST (WHICH IS IN QUESTION STILL). && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 140 PM MONDAY... 24-HR TAF PERIOD: WEAK SHORTWAVE IMPULSES EMBEDDED IN THE MOIST SWLY FLOW ALOFT WILL CONTINUE TO SUPPORT WIDESPREAD SHOWERS AND RAIN ACROSS THE AREA THROUGH THE REMAINDER OF THE AFTERNOON. CEILINGS SHOULD FLUCTUATE BETWEEN IFR TO MVFR WITH PERIODS OF RAIN THROUGH 00Z. ONCE THE PRECIP TAPERS OFF...CEILINGS COULD BRIEFLY IMPROVE TO MVFR AND POSSIBLY VFR THIS EVENING BETWEEN 00Z TO 04Z WITH CONDITIONS THEN RAPIDLY DETERIORATE OVERNIGHT WITH A RETURN OF LIFR TO IFR CONDITIONS IN LOW CLOUDS AND POSSIBLY FOG ACROSS THE EAST IN THE VICINITY OF THE DISSIPATING STALLED SURFACE FRONT. ANY SUB-VFR CONDITIONS ARE EXPECTED TO IMPROVE AOA 15Z TUESDAY WITH NUMEROUS SHOWERS AND STORMS DEVELOPING WITHIN THE MOIST AND INCREASINGLY UNSTABLE AIR ACROSS THE AREA TUESDAY AFTERNOON. LOOKING AHEAD: AT THIS TIME IT APPEARS THAT PRIMARILY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS CAN BE EXPECTED THROUGH THE WORK WEEK...WITH A POTENTIAL FOR SUB-VFR FOG OR STRATUS DURING THE EARLY MORNING HOURS...PRIMARILY BETWEEN 07-13Z. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...CBL SHORT TERM...CBL LONG TERM...KRR AVIATION...CBL