Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 102025 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 425 PM EDT THU JUL 10 2014 .SYNOPSIS... A FRONTAL BOUNDARY REMAINS STALLED OVER THE REGION TONIGHT...AND SLOWLY PUSHES SOUTH AND EAST ON FRIDAY AS A WEAK AREA OF LOW PRESSURE MOVES NORTHEAST ALONG THIS BOUNDARY. HIGH PRESSURE BUILDS SOUTH ACROSS THE MID ATLANTIC REGION FRIDAY NIGHT INTO SATURDAY. LOW PRESSURE MOVES THROUGH THE GREAT LAKES ON SUNDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... LATEST ANALYSIS INDICATES A FRONTAL BOUNDARY NOW SETUP OVER THE VA PIEDMONT...RATHER DIFFUSE AND DIFFICULT TO FIND GIVEN ALL OF THE CONVECTION THAT HAS AFFECTED THE REGION THUS FAR THIS AFTN. BACK EDGE OF WIDESPREAD PRECIP AND SOME CLEARING SKIES PUSHING INTO AREAS WEST OF I-95 NOW...BUT WITH UPPER TROUGH AXIS STILL WEST OF THE APPALACHIANS EXPECT ANOTHER BATCH OF SHOWERS AND TSTMS TO OVERSPREAD THE REGION LATER THIS EVENING. FARTHER EAST...SEVERE WX HAS GENLY PUSHED OFF THE COAST FOR THE TIME BEING...ALTHOUGH ANOTHER ROUND OF STORMS NOW PUSHING NE FROM NC AND SHOULD OVERSPREAD INTERIOR NE NC COUNTIES AND EVENTUALLY SE VA COUNTIES IN THE NEXT FEW HRS. MAIN CONCERN LATER THIS EVENING AND OVERNIGHT WILL BE FOR ADDITIONAL HEAVY RAIN...PRIMARILY IN SE VA/NE NC (SEVERE THREAT SEEMS TO BE WANING BUT FOR NOW SEVERE TSTM WATCH REMAINS IN EFFECT IN SE VA/NE NC). SHEARED OUT S/W ENERGY TRACKS E OF THE MTNS OVERNIGHT AND LOOKS TO KEEP LIKELY POPS IN SE VA/NE NC EVEN WELL AFTER MIDNIGHT...PARTICULARLY ACRS SE VA/NE NC. LOWS MID-UPPER 60S FAR NW TO LWR-MID 70S SE. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... SYSTEM LINGERS ALONG COASTAL AREAS FRIDAY MORNING BEFORE SLOWLY EXITING OFF THE COAST DURING THE AFTN. DATA SHOWS PLENTY OF MSTR ARND ALONG WITH SOME INSTABILITY TO INCLUDE CHC POPS THROUGH THE DAY WITH THE HIGHEST POPS SERN AREAS. HIGHS GNRLY IN THE M80S. SCT EVENING POPS FRI NIGHT...OTW BCMG PT CLDY. LOWS 65-70 F. MODELS INDICATING THE FRONT WASHES OUT / DISSIPATES ACROSS THE AREA SAT. KEPT A 20% POP OVER THE FAR NW AND IN SE VA/NE NC. PARTLY SUNNY WITH HIGHS IN THE M-U80S. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... HIGHLY ANOMALOUS FLOW WILL DEVELOP OVER THE CONUS DURING THE MEDIUM RANGE...AS A STRONG CLOSED LOW DROPS OVER THE GREAT LAKES REGION. THE RESULT WILL BE BELOW NORMAL TEMPS AND WET CONDITIONS FROM THE UPPER MIDWEST TO THE OH VALLEY. HOWEVER...THE LOCAL AREA REMAINS SEASONABLY WARM AS MUCH OF THE COOLER AIR WILL BE LOCKED WEST OF THE CNTRL APPALACHIANS. AS AN ANOMALOUS TROUGH DEVELOPS OVER THE ERN CONUS...HEIGHT FALLS AND INCREASE WINDS ALOFT WILL RESULT IN BETTER FORCING FOR ASCENT OVER THE LOCAL AREA. WITH A WARM/MOIST AIRMASS ALREADY IN PLACE (MODEL DERIVED PRECIP WATERS ~ 2+ INCHES)...EXPECT BETTER COVERAGE OF SHOWERS/THUNDERSTORMS MON AFTERNOON ALONG A SHARPENING LEE/THERMAL TROUGH. HOWEVER...THE BEST DYNAMICS WILL REMAIN WEST OF THE LOCAL AREA ALONG THE COLD FRONT...SO THE BEST CHANCES WILL BE IN THE NORTH AND WEST. ANOTHER AREA OF SHOWERS/THUNDERSTORMS WILL LIKELY DEVELOP ALONG THE TROUGH/BOUNDARIES...CLOSEST TO THE BEST INSTABILITY. STILL SOME SUBSIDENCE/WARM AIR ALOFT VISIBLE IN SOUNDINGS...SO WILL LEAVE AT LOW END CHANCE. HIGHS MON EXPECTED IN THE LOW-MID 90S. WITH DEWPOINTS IN THE MID-UPPER 60S...HEAT INDICES WILL BE NEAR 100 INLAND. STRONG SPEED MAX ROUNDS THE DEEP CLOSED LOW OVER THE GREAT LAKES TUES...EJECTING THE LOW NEWD INTO SE CANADA. THE COLD FRONT DROPS INTO THE REGION TUES-TUES NIGHT. STRONGEST DYNAMICS LIFT WELL NORTH OF THE REGION WITH THE CLOSED LOW...BUT HEIGHT FALLS AND PERTURBATIONS IN THE WSW FLOW WILL RESULT IN SCT-NUMEROUS SHOWERS/THUNDERSTORMS. BASED ON SPATIAL AND TIMING DIFFERENCES OF THE FRONT AND STILL BEING DAY 6...WILL CAP POPS AT CHANCE WITH THIS PACKAGE. STRONG TO SEVERE THUNDERSTORMS ALSO POSSIBLE AS MODELS DEPICT MARGINAL SHEAR AND MLCAPE > 2500 J/KG. ANOMALOUS TROUGH WILL PUSH THE SRN PORTION OF THE FRONT INTO THE DEEP SOUTH...BUT THE ERN PORTION LIKELY STALLING OVER/OFF THE MID-ATLANTIC COAST AS AN ANOMALOUS UPPER RIDGE REMAINS PARKED OVER THE WRN ATLANTIC. WILL MAINTAIN SLIGHT CHANCE-CHANCE POPS WEDS ACROSS THE SE AS THE FRONT WILL LIKELY LINGER OVER THE REGION. SFC HIGH PRESSURE WILL BE SLOW TO BUILD INTO THE REGION IN WAKE OF THE FRONT AS UPPER TROUGH REMAINS OVER THE ERN CONUS. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... TSTMS CONTINUE ACROSS SE VA AND NE VA AS THE STRONGEST STORMS HAVE MOVED OFF THE COAST. EXPECT SOME CLEARING THROUGH 23Z...BUT DO THINK SHOWERS AND THUNDERSTORMS WILL REDEVELOP TONIGHT ALONG A STALLED FRONTAL BOUNDARY. MVFR AND IFR FOG/CEILINGS ARE POSSIBLE OVERNIGHT AS THE LOWER ATMOSPHERE REMAINS SATURATED DUE TO HEAVY RAINS AND CONTINUED MOIST FLOW. EXPECT SHOWERS AND THUNDERSTORMS TO FORM ALONG A SOUTHWARD SINKING FRONT FRIDAY AFTN. FRONT CROSSES AREA BY FRIDAY...LEAVING FRI NGT/SAT DRY ATTM. NEXT FRONT COULD BRING THE POTENTIAL FOR MORE SHWRS/TSTMS TO THE REGION LATE SUNDAY OR MONDAY. && .MARINE... SUB-SCA CONDITIONS ARE EXPECTED OVER THE WATERS THROUGH THE WEEK. A WEAK TROF IS TO THE WEST OF THE WATERS KEEPING MAINLY A LIGHT SOUTHERLY WIND OVER THE WATERS. A WEAK LOW PRESSURE SYSTEM WILL MOVE ALONG THIS BOUNDARY TONIGHT AND FRIDAY. THIS WILL ALLOW THE WINDS TO BE MORE SOUTHEAST AT TIMES. AFTER THE LOW MOVES PAST FRIDAY NIGHT THE TROF WILL MOVE OFF THE COAST SATURDAY. WILL HAVE LIKELY THUNDERSTORMS THIS AFTERNOON AND TONIGHT OVER THE SOUTHERN WATERS WITH A CHANCE ACROSS THE NORTHERN WATERS.SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS THE WATERS FRIDAY INTO FRIDAY NIGHT. WINDS WILL BECOME MORE WEST TO NORTH OVER THE WEEKEND. FLOW VEERS TO THE SOUTH SUN...REMAINING SUB SCA AT 10-15 KT. SEAS REMAIN 2-3 FT. LOW PRESSURE LIFTS INTO THE GREAT LAKES REGION MON AS A COLD FRONT PUSHES INTO THE OH VALLEY. GRADIENT WILL STRENGTHEN SLIGHTLY OVER THE WATERS SUN NIGHT-MON...BUT REMAINS SUB-SCA. PERSISTENT SLY FLOW WILL PUSH SEAS TO 4 FT IN THE NRN WATERS...BUT ANTICIPATE SEAS TO REMAIN UNDER 5 FT. COLD FRONT CROSSES THE WATERS TUES NIGHT-WED MORNING. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...LKB NEAR TERM...LKB SHORT TERM...LKB/MPR LONG TERM...SAM AVIATION...DAP MARINE...SAM

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