Area Forecast Discussion
Issued by NWS Sterling, VA

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194 FXUS61 KLWX 271848 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 248 PM EDT WED APR 27 2016 .SYNOPSIS... A COLD FRONT WILL REMAIN STALLED NEAR THE VIRGINIA-NORTH CAROLINA BORDER THROUGH FRIDAY. WAVES OF LOW PRESSURE WILL RIDE ALONG THE BOUNDARY DURING THIS TIME. THE BOUNDARY MAY DROP A BIT FARTHER SOUTH SATURDAY...BUT ANOTHER WAVE OF LOW PRESSURE WILL TRACK ALONG THE FRONT FOR SUNDAY INTO MONDAY. && .NEAR TERM /THROUGH TONIGHT/... THE BNDRY REMAINS STALLED ACRS SRN VA TAFTN. TEMPS ONCE AGN IN THE LWR 80S SOUTH OF THIS BNDRY...BUT ONLY IN THE LWR 50S ACRS MUCH OF MD. A RDG OF SFC HIPRES EXTENDS DOWN THE COAST FM NEW ENGLAND. IN ADDITION...A RDG AXIS EXISTS ALOFT ACRS THE GRTLKS TO SERN CONUS. THEREFORE...THE NEAREST DIURNAL TSRA DVLPG ACRS ERN KY/SRN WVA/WRN VA. THE QSTN WL BE WHETHER THESE STORMS CAN REACH SRN CWFA. BASED ON SYNOP SETUP AND STBL AMS...AM BETTING AGAINST IT. TO PROVIDE A BUFFER NEED TO INCL CHC POPS ACRS CENTRAL VA/SRN MD...BUT FCST UNDERCUTS MOS SIGNIFICANTLY. ISENT UPGLIDE IMPRV OVNGT...SO WL INCR POPS SLGTLY. AM NOT SOLD ON ACCUM QPF...SO AM KEEPING POPS AT CHC. UTILIZED A MDL BLEND FOR MIN-T...WHICH YIELDS UPR 40S ACRS NRN MD TO MID 50S CENTRAL VA. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... PTTN REMAINS UNCHGD THRU THE END OF THE WEEK...AS STALLED FRONT POISED S OF CWFA. ANY S/WV RIDING ALONG THIS BNDRY CUD TRIGGER A FEW SHRA. THERE WONT BE MANY SUBSTANTIVE CHGS TO THE FCST GIVEN THESE SUBTLETIES...AND THE CHALLENGES W/ FORECASTING THEM THIS FAR OUT. ONE KEY FEATURE THAT IS DISCERNABLE ATTM IS THE CLOSED LOW ACRS THE PLAINS OPENS UP AND TRAVERSES THE CONUS DURING THE PD. THE SFC REFLECTION WL MIGRATE EWD AS WELL...ALONG THE BNDRY... WHICH WL PROVIDE THE IMPETUS FOR SHRA. THEREFORE WL INCR POPS TO LKLYS THU MIDDAY THRU MIDNGT. BYD THAT IT IS UNCLR HOW MUCH MSTR THE SUBSEQUENT VORT WL HV... EXACTLY WHERE IT WL TRACK...AND HOW STRONG IT WL BE. WL REVERT BACK TO CHC POPS FOR FRI. FEW TEMP CHGS DURING THE PD AS WELL. IT WL BE TOUGH FOR MUCH OF MD TO CRACK 60 DEGF...SPCLY ON THU. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... HIGH PRESSURE WILL REMAIN WEDGED ALONG THE EASTERN SLOPES OF THE APPALACHIAN MOUNTAINS SATURDAY THROUGH SUNDAY. SOME OVERRUNNING WARMTH AND MOISTURE SATURDAY NIGHT AND AN APPROACHING UPPER LEVEL DISTURBANCE WILL RIDE ALONG THE OHIO VALLEY INTO OUR REGION AND BRING A THREAT FOR PERIODS OF RAIN. PERIODS OF RAIN WILL BECOME MORE PRONOUNCED AND PROLONGED SUNDAY INTO SUNDAY NIGHT AS THE MAIN UPPER LEVEL TROUGH PIVOTS INTO THE AREA AND A SURFACE LOW PRESSURE SYSTEM DEVELOPS OVER SOUTHWEST VIRGINIA. ADDITIONAL UPPER LEVEL ENERGY WILL ROTATE WITHIN THE MAIN TROUGH OF LOW PRESSURE MONDAY INTO MONDAY NIGHT...LEAVING THE CHANCE FOR ADDITIONAL RAIN SHOWERS ACROSS THE REGION. THE SURFACE LOW AND UPPER ENERGY SHOULD EXIT THE EAST COAST TUESDAY TO ALLOW FOR A RIDGE OF HIGH PRESSURE TO BUILD INTO THE REGION TUESDAY NIGHT AND WEDNESDAY. DRIER CONDITIONS ON THE WAY. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... UNSTTLD PTTN THRU THE TAF PD...AND THRU THE END OF THE WK FOR THAT MATTER. STALLED FRNTL BNDRY S OF THE TERMINALS. ONSHORE FLOW BRINGING MARINE STRATUS/STCU. WL STICK MAINLY W/ MVFR FLGT CONDS. CUD BE A FEW SHRA INVOF CHO THIS EVNG...BUT LOW CONFIDENCE. BETTER CHC AT SEEING SHRA THU PM. PDS OF IFR PSBL TNGT...AND SPCLY THU AFTN-NGT. HV NOT PLACED AOB IFR IN ANY TAF ATTM. SHOULD IMPROVE TO VFR ON FRI. VFR CONDITIONS EXPECTED SATURDAY AS WELL. WINDS NORTHEAST LESS THAN 5 KNOTS. VFR CONDITIONS BECOMING MVFR OR IFR SATURDAY NIGHT WITH APPROACHING RAIN SHOWERS FROM THE WEST. WINDS BECOMING SOUTHEAST AROUND 5 KNOTS. && .MARINE... ONSHORE FLOW WL REMAIN IN PLACE THRU THE END OF THE WEEK INTO THE WKND. WIND SPDS AOB 10-15 KT THRU THE PD. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...HTS NEAR TERM...HTS SHORT TERM...HTS LONG TERM...KLW AVIATION...HTS/KLW MARINE...HTS

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