Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 270846 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 346 AM EST FRI FEB 27 2015 .SYNOPSIS... A COLD FRONT WILL SLOWLY MOVE EAST OF THE AREA THIS MORNING. HIGH PRESSURE WILL BUILD OVERHEAD TONIGHT INTO SATURDAY. THE HIGH WILL MOVE OFF THE COAST SUNDAY AND ANOTHER COLD FRONT WILL PASS THROUGH THE AREA SUNDAY NIGHT. A WARM FRONT AND LOW PRESSURE WILL CROSS THE AREA TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LTST SFC ANALY INDICATES WEAK SFC REFLECTION FM UPR TROF AXIS HUNG UP INVOF THE BLURDG/CATOCTINS. IT SHUD BE ABLE TO MAKE IT TO I-95 AND THE BAY BY SUNRISE. GDNC CONTS TO PRINT OUT LGT QPF. AM THINKING IT/LL LKLY BE NO MORE THAN FLURRIES DUE TO LMTD SUPPORT AND MSTR /AS EVIDENCED BY RADAR LOOP/. HV SCALED BACK POPS A BIT...BUT AM STILL CARRYING 20-30 PCT IN CASE A QUICK DUSTING OCCURS. THAT/LL REPRESENT THE WORST-CASE SCENARIO. NLY SFC FLOW PTTN WL CONT THRU THE DAYLIGHT HRS...W/ FLOW BACKING WLY THRU H5. STILL HV FAST FLOW THRUT...W/ THE ULVL JET /140 KT/ NEARLY OVRHD. WUD NOT RULE OUT ANOTHER FLURRY OR TWO SOMEWHERE W/IN THE CWFA TAFTN...SO WL PRESERVE THAT WORDING. THE FLOW PTTN MAY PROVIDE A SLGT BOOST IN THE MTNS TOO...BUT TRAJECTORY NOT OPTIMAL. THAT MAY BE THE PLACE THAT FLURRIES MOST LKLY. BELIEVE THE BIGGER ISSUE WL BE MOCLDY SKIES FM RESUDUAL LLVL MSTR SEEN ON MDL SNDGS AND 20 KT WIND GUSTS W/IN MEAN MIXED LYR. COMBINED W/ CAA...TEMPS WL BE STRUGGLING TO REACH FRZG...WHICH MEANS THAT WIND CHILLS WL AGN BE A FACTOR. TEMP GDNC HAS CONSISTENTLY SUGGESTED THAT CHO-EZF WL REACH MID 30S...SO HV REFLECTED THAT IN GRIDS TOO. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... A SPRAWLING AREA OF HIGH PRESSURE IN THE CENTRAL CONUS WL BE WORKING EWD TNGT-SAT. CLDS WL BECOME MORE SCARCE AS SUBSIDENCE INCREASES. THERE IS DCPLG POTL TNGT. IF THAT OCCURS...THEN TEMPS CUD TUMBLE. HV NOT REFLECTED THAT IN DATABASE /AM HOLDING ONTO 5 KT WIND/...BUT IF FCST WERE TO GO ASTRAY...THATS MOST LKLY WHERE. AM USING MOS MEAN... WHICH YIELDS MIN-T BTWN MID SINGLES WEST TO MID TEENS EAST. CORE OF COLD AIR WL BE OVER/JUST N OF CWFA SAT...SPCLY IN THE MRNG. THUS...THIS WL BE THE COLDEST DAY BEFORE REBOUND OCCURS. MAXT INTHE 20S EVERYWHERE. FURTHER...THINK THERE WL BE ENUF MSTR IN THE COLUMN FOR AT LEAST PTCLDY SKIES. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... HIGH PRESSURE WILL BE LOCATED ACROSS NEW ENGLAND AND THE MID- ATLANTIC SATURDAY NIGHT WHILE A JET STREAK MOVES NORTHWARD INTO THE MID-WEST. LOW PRESSURE WILL INTENSIFY ACROSS THE CENTRAL PLAINS AS A SHORTWAVE TROUGH DROPS INTO THE NRN PLAINS SUNDAY. WARM AIR ADVECTION AHEAD OF THE SYSTEM WILL BRING GULF AND ATLANTIC MOISTURE INTO THE MID-ATLANTIC SUNDAY AFTERNOON. PRECIPITATION IS EXPECTED TO MOVE INTO THE POTOMAC HIGHLANDS SUN MORNING AND SPREAD EASTWARD. PWATS ARE EXPECTED TO DOUBLE DURING THE DAY. HIGH PRESSURE IS EXPECTED TO KEEP COLD AIR IN PLACE ACROSS THE MID-ATLANTIC LEADING TO SUB FREEZING TEMPERATURES AS PRECIPITATION MOVES INTO THE REGION. WINDS ARE EXPECTED TO BECOME SOUTHERLY SUNDAY MORNING BUT LIGHT AND WARM AIR ADVECTION WILL LIKELY BE SLOW UNTIL WINDS INCREASE...WHICH MAY NOT HAPPEN DURING THE DAY. IF THAT IS THE CASE...TEMPS WILL BE SLOWER TO RISE AND AREAS ACROSS CENTRAL VA MAY SEE A PERIOD OF WINTRY PRECIPITATION. GUIDANCE SHOWS TEMPS RISING ABOVE FREEZING SUNDAY IN THIS AREA BUT DUE TO THE LIGHT WINDS LEFT A CHANCE OF IP/ZR ACROSS THE ENTIRE AREA. PRECIPITATION IS EXPECTED TO BEGIN AS SNOW BUT THEN SWITCH TO IP/ZR BY SUNDAY AFTERNOON. THE BEST CHANCE OF IP/ZR AND LIGHT ICE ACCUMULATION WILL BE FURTHER NORTH NEAR THE MD/PA BORDER WHERE SFC TEMPS WILL STAY NEAR OR BELOW FREEZING DURING THE DAY AND POSSIBLY INTO THE EVENING. AREAS SOUTH OF DC MAY NOT SEE MUCH QPF AS MUCH OF THE FORCING IS FURTHER NORTH HOWEVER...MOISTURE ADVECTION WILL LIKELY LEAD TO A PERIOD OF RA/IP/ZR. A COLD FRONT MOVES THROUGH THE REGION SUNDAY NIGHT AND DRY CONDITIONS ARE EXPECTED MONDAY WITH THE EXCEPTION OF UPSLOPE SN/RA SHOWERS ALONG THE WESTERN SLOPES. HIGH PRESSURE MOVES INTO THE REGION MONDAY NIGHT AND TUESDAY. A COLORADO LOW WILL DEVELOP EARLY NEXT WEEK AND TRACK ACROSS THE CENTRAL PLAINS AND EVENTUALLY THE GREAT LAKES. ANOTHER ROUND OF WARM AIR ADVECTION WILL BUILD INTO THE REGION TUESDAY. COLD SURFACE TEMPS WILL PERSIST ACROSS THE MID- ATLANTIC AND ANOTHER ROUND OF ICING IS POSSIBLE TUESDAY NIGHT INTO WEDNESDAY BEFORE A WARM FRONT PASSAGE. THIS WARM FRONT WILL BRING MUCH RELIEF TO THE MID-ATLANTIC WITH TEMPERATURES FORECAST IN THE 50S TO NEAR 60 BY WED AFTERNOON. A COLD FRONT WILL MOVE THROUGH THE REGION BY THURSDAY AND TEMPS WILL LOWER TO NEAR NORMAL. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... TAFS ON THE CUSP BTWN MVFR AND VFR ATTM DUE TO CIGS AS A TROF AXIS SLIDES OVERHEAD. SHUD GET TO VFR IN ITS WAKE /BY MIDDAY/ AND REMAIN THERE FOR THE REST OF THE VALID TAF PD. N/NWLY WINDS WL ALSO PICK UP BY MIDDAY...W/ GUSTS UP TO 20 KT AVBL W/IN MEAN MIXED LYR. WINDS SHUD RELAX AND CLDS SLOWLY SCATTER OUT TNGT. LGT WNDS AND SCT CLDS WL CARRY INTO SAT. A WINTRY MIX IS POSSIBLE SUNDAY AFTERNOON AT THE TERMINALS AND MVFR/IFR CONDITIONS ARE LIKELY AS PRECIPITATION MOVES INTO THE REGION. ANOTHER ROUND OF WINTRY MIX IS POSSIBLE TUESDAY AND TUESDAY NIGHT. && .MARINE... LGT WINDS ON THE WATERS ATTM. XPCT WINDS TO INCREASE DURING THE MRNG IN THE WAKE OF A TROF AXIS. UP TO 20KT AVBL W/IN MEAN MIXED LYR. SCA FOR ALL WATERS APPEARS ON TRACK FOR THE MIDDAY-AFTN. WL CONT ADVY FOR TNGT...BUT HV PULLED BACK N OF POOLES ISLAND. HIGH PRESSURE WILL PERSIST ACROSS THE AREA SATURDAY NIGHT BEFORE MOVING OFF THE COAST SUNDAY. SCA CONDITIONS ARE POSSIBLE SUNDAY NIGHT INTO MONDAY AHEAD AND BEHIND A FRONTAL PASSAGE. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 6 AM EST SATURDAY FOR ANZ530>534-537-539>541-543. SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 6 PM EST THIS EVENING FOR ANZ535-536-538-542. && $$ SYNOPSIS...HTS NEAR TERM...HTS SHORT TERM...HTS LONG TERM...HAS AVIATION...HTS/HAS MARINE...HTS/HAS

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