Area Forecast Discussion
Issued by NWS Wilmington, NC

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS62 KILM 291737 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 130 PM EDT WED JUL 29 2015 .SYNOPSIS... HIGH PRESSURE WILL SLOWLY WEAKEN THROUGH MID WEEK. A PIEDMONT TROUGH WILL FORM THIS AFTERNOON AND LINGER ON THURSDAY AS WEAK LOW PRESSURE REMAINS OFF THE SOUTHEAST COAST. A COLD FRONT WILL MOVE INTO THE AREA FRIDAY AND STALL DURING THE WEEKEND BEFORE DISSIPATING MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 930 AM WEDNESDAY... 12Z RAOBS SHOWED AN INVERSION AT AROUND 900MB THAT HAS RECENTLY BEEN OVERCOME DUE TO MIXING. DRY AIR ABOVE THIS LAYER MEANS THAT CUMULUS CLOUDS WILL BE SLOW TO DEVELOP IN MOST AREAS. MEANWHILE FAR WESTERN ZONES HAVE A MORE STRATOCU APPEARANCE ON VIS SAT IMAGERY WHERE A BIT OF MOISTURE HAD RESIDED ABOVE THIS INVERSION. HEATING WILL MAKE THESE CLOUDS TAKE ON A MORE CELLULAR APPEARANCE AND THEY INDICATE THE ONLY REAL AREAS THAT HAVE ANY SHOT AT PRECIPITATION. THE LATEST 12Z WRF KEEPS THIS ACTIVITY LARGELY TO OUR WEST BUT FEEL THAT THE CLOUD LINE REPRESENTS WHERE 20 POPS ARE WARRANTED. THIS IS VERY MUCH IN LINE WITH THE PREVIOUS FORECAST AND NOT ANTICIPATING ANY CHANGES AT THIS TIME. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...PRECIP CHANCES WILL BE ON THE INCREASE DURING THE PERIOD AS 5H RIDGE BREAKS DOWN AND 5H TROUGH STARTS TO SET UP. ILL DEFINED SURFACE PATTERN ON THU WILL ALLOW SEA BREEZE AND PIEDMONT TROUGH CONVECTION BUT LACK OF SIGNIFICANT SURFACE OR MID LEVEL TRIGGERS WILL KEEP COVERAGE LIMITED. PRECIP CHANCES START TO INCREASE THU NIGHT AS WEAKENING COLD FRONT MOVES IN FROM THE NORTHWEST. FRONT ARRIVES AS INSTABILITY IS WANING WHICH SHOULD KEEP COVERAGE FOR THU NIGHT IN SLIGHT CHC RANGE AT MOST DESPITE THE PRESENCE OF LOW LEVEL CONVERGENCE AND DEEP MOISTURE. FRONT REMAINS IN THE AREA FRI...SERVING AS A FOCAL POINT FOR CONVECTION. DIURNAL INSTABILITY WILL HAVE PLENTY OF DEEP MOISTURE TO WORK WITH...PRECIPITABLE WATERS EXCEED 2 INCHES LATER IN THE DAY. WEAKENING SUBSIDENCE AND INSTABILITY ALONG WITH WHAT APPEARS TO BE SOME SLIGHT PVA FRI AFTERNOON INCREASES PRECIP CHANCES FRI INTO FRI NIGHT. WILL CONTINUE WITH INHERITED LIKELY POP BUT WONDER IF MID LEVEL RIDGING MIGHT HOLD ON A BIT LONGER THAN GUIDANCE IS SUGGESTING. SHOULD THAT BE THE CASE LINGERING SUBSIDENCE COULD KEEP CONVECTION IN CHECK...RESULTING IN SLIGHTLY LOWER POP THAN WHAT IS CURRENTLY FORECAST FOR THE SECOND HALF OF THE PERIOD. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY...STALLED FRONT AND DEEP MOISTURE LINGERS OVER THE AREA SAT KEEPING WEATHER UNSETTLED THROUGH THE WEEKS END. AT THIS POINT UNCERTAINTY IN THE FORECAST REALLY STARTS TO INCREASE. BOTH GFS AND ECMWF SHOW A 5H TROUGH DIGGING DOWN THE EAST COAST. MID LEVEL TROUGH PUSHES THE DEEP MOISTURE OFF THE COAST FOR THE START OF NEXT WEEK WITH THE REGION DRYING OUT. SURFACE PATTERN REMAINS ILL DEFINED AND WHATS LEFT OF THE SURFACE BOUNDARY WILL LINGER IN THE AREA. HOWEVER THE LACK OF DEEP MOISTURE KEEPS PRECIP CHANCES AT OR BELOW THE TYPICAL SUMMERTIME AFTERNOON 30 POP TO START THE WEEK. PREVIOUSLY GUIDANCE HAD BEEN SHOWING A STRONGER SHORTWAVE DROPPING ACROSS THE AREA IN THE DEEP NORTHWEST FLOW TUE. WHILE THIS FEATURE IS STILL DISCERNIBLE...JUST BARELY...IT IS IN A WEAKER STATE. AS THESE SHORTWAVES ARE FREQUENTLY CONVECTIVELY INDUCED/INFLUENCED WILL NOT GO ABOVE CLIMO POP FOR THE END OF THE PERIOD GIVEN THE HEIGHTENED UNCERTAINTY. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE CLIMO...GENERALLY NEAR CLIMO BY DAY AND SLIGHTLY ABOVE BY NIGHT. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AS OF 18Z...A COASTAL LOW AND TROUGH WILL KEEP CONVECTION OFFSHORE TODAY. VERY LITTLE MOISTURE TO WORK WITH TODAY...WITH SCATTERED CU AND TRANSITORY UPPER CLOUDS EXPECTED. ONSHORE FLOW WILL KEEP THINGS FAIRLY PLEASANT TODAY...WITH SLIGHTLY BELOW NORMAL TEMPERATURES ALONG THE COAST. LIGHT WINDS THIS EVENING WITH LIGHT FOG POSSIBLE TOWARD DAYBREAK. CHANCES FOR PRECIP WILL BE INCREASING ON THURSDAY AS A FRONTAL BOUNDARY APPROACHES. EXTENDED OUTLOOK...PREDOMINANTLY VFR THROUGH THE PERIOD WITH A SLIGHT CHANCE AFTERNOON SHRA/TSRA. BEST CHANCE SHRA/TSRA FRIDAY AND SATURDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 930 AM WEDNESDAY...ONSHORE FLOW QUASI-STEADY TODAY. NOT EXPECTING ANY CHANGES TO THE FORECAST. THE PREVIOUS DISCUSSION FOLLOWS. AS OF 538 AM WEDNESDAY...E WIND 10-15 KT TO PREVAIL TODAY AND TONIGHT...ACCOMPANIED BY 3-3.5 FOOT SEAS. OCCASIONAL GUSTS TO 20 KT OUGHT TO BE ANTICIPATED...ESPECIALLY IN THE AFTERNOON NEARSHORE. SEAS PRIMARILY A MIX OF SE WAVES 2-3 FT EVERY 6 SECONDS AND MODERATE EASTERLY CHOP. SHOWERS AND TSTMS ARE EXPECTED TO REMAIN WELL BEYOND THE 0-20 NM WATERS TODAY AND NO RESTRICTIONS TO VISIBILITY ARE EXPECTED. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...ILL-DEFINED GRADIENT AND WEAK SURFACE WAVE PASSING EAST OF THE WATERS THU WILL INDUCE LIGHT NORTH TO NORTHEAST FLOW INTO THU NIGHT. WAVE MOVES OFF TO THE NORTHEAST THU NIGHT INTO FRI AS WEAK SURFACE FRONT DROPS IN FROM THE NORTHWEST. LIGHT AND VARIABLE WINDS THU NIGHT GAIN A SOUTHWEST COMPONENT FRI AND FRI NIGHT BUT LACK OF ANY REAL GRADIENT KEEPS SPEEDS AROUND 10 KT THROUGH THE END OF THE PERIOD. SEAS 2 TO 3 FT THROUGH THE PERIOD. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 AM WEDNESDAY...SOUTHWEST FLOW WILL CONTINUE OVER THE WATERS THROUGH THE WEEKEND. THE REMAINS OF A STALLED FRONT WILL LINGER NEAR THE COAST AS BERMUDA HIGH TRIES TO BUILD BACK WEST. GRADIENT WILL REMAIN ON THE WEAK SIDE WITH SPEEDS NO MORE THAN 10 TO 15 KT AT ANY POINT DURING THE PERIOD. DAILY SEA BREEZE WILL RESULT IN ENHANCED ONSHORE FLOW NEAR THE COAST BOTH DAYS. SEAS WILL RUN 2 TO 3 FT ON SAT AND 2 TO 4 FT SUN. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...MBB SHORT TERM...III LONG TERM...III AVIATION...43

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.