522 FXUS61 KLWX 150757 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 357 AM EDT SUN APR 15 2012 .SYNOPSIS... HIGH PRESSURE OFF THE SOUTHERN ATLANTIC COAST WILL BE A WARM FRONT JUST TO OUR NORTH OVER THE NEXT COUPLE OF DAYS. THIS WILL CREATE WARM CONDITIONS THAT WILL BE WELL ABOVE NORMAL SUNDAY AND MONDAY. A COLD FRONT WILL CROSS THE REGION MONDAY NIGHT. HIGH PRESSURE BUILDS IN MIDWEEK. && .NEAR TERM /UNTIL 10 PM THIS EVENING/... A LARGE BATCH OF LIGHT SHOWERS HAVE MADE IT ACROSS THE MASON-DIXON LINE /REMNANTS OF A WELL-DISSIPATED MCS FEATURE THAT ARRIVED FROM THE OHIO VLY/. THIS BATCH HAS BEEN MOVING ESE ALONG THE WARM FRONTAL REGION WHICH IS SET-UP IN BETWEEN THE I-80 AND I-90 CORRIDORS WELL TO OUR NORTH. SCATTERED PIECES OF THE BATCH OF RAIN ARE STREWN ACROSS AND BACK TOWARD SRN SHORES OF LAKE ERIE...SO THE RAIN FOR THE CWA IS NEAR ITS END /EXPECT FOR EXTREME NERN MD/. SKIES WILL FOLLOW SUIT HEADING THRU THE MRNG HRS TODAY AND THIS AFTN...CLEARING OUT OVER TIME. WITH THE HIGHER LOW LEVEL MOISTURE CONTENT TONIGHT AND THE SOLID OVERHEAD CLOUD COVER...TEMPS ARE HAVING TROUBLE DROPPING OUT OF THE 60S INTO THE 50S. THIS WILL GIVE THE REGION A GOOD START TO ONE OF THE WARMEST DAYS SINCE LATE MARCH. BY MID AFTN...TEMPS WILL BE CLIMBING INTO THE L80S AND TOP OUT IN THE M80S FOR MUCH OF THE AREA. BREEZY SWLY WINDS WILL BE ON THE INCREASE OVER THE COURSE OF THE DAY...AS THE OFFSHORE RIDGE STRENGTHENS IN THE WAKE OF THE INCOMING LOW PRESSURE SYSTEM /CAUSING THE WIDESPREAD SVR WX OVER THE PLAINS/. THE LOW PRESSURE SYSTEM OVER THE PLAINS WILL LARGELY DISSIPATE BEFORE REACHING THE APLCNS...BUT W/ THE UPPER RIDGE HOLDING STRONG - IT WILL GIVE THE AREA AT LEAST TWO VERY WARM DAYS UP ACROSS THE ERN SEABOARD. HIGHS BOTH TODAY AND MONDAY WILL BE AROUND 15-20 DEG ABOVE NORMAL FOR THIS TIME OF YEAR. WINDS WILL SUBSIDE LATER THIS EVE AND AN EVEN WARMER OVERNIGHT PERIOD EXPECTED...WHERE MOST AREAS WILL STAY IN THE 60S BEFORE ANOTHER INCREASE BACK INTO THE 80S ON MONDAY. && .SHORT TERM /10 PM THIS EVENING THROUGH 6 AM MONDAY/... WARM MOIST AIR CONTINUES OVER THE REGION MONDAY WITH HIGH PRESSURE OFFSHORE...WHILE A COLD FRONT APPROACHES FROM THE WEST. WARMING TREND SHOULD REACH ITS PEAK MONDAY UNDER SW FLOW. 850MB TEMPS STILL FCST TO BE AROUND 13C...WITH AFTERNOON HIGH TEMPS REACHING THE MID 80S OVER MOST OF THE CWA. SOME SHOWER/TSTM ACTIVITY ASSOCIATED WITH THE COLD FRONT COULD REACH WESTERN PORTIONS OF THE CWA BY THE END OF THE DAY. COLD FRONT PUSHES THROUGH THE CWA MONDAY NIGHT. MODELS CONTINUE TO INDICATE ANY ASSOCIATED SHOWER/TSTM ACTIVITY WOULD LIKELY DISSIPATE OVERNIGHT DUE TO DECREASING INSTABILITY AND WEAKENING OF THE FRONT. INITIATION OF CAA WILL RESULT IN COOLER LOW TEMPS EARLY TUESDAY...WITH LOWS RANGING FROM THE UPPER 40S OVER THE POTOMAC HIGHLANDS TO THE LOW 60S IN THE BALTIMORE/WASHINGTON METROS. && .LONG TERM /TUESDAY THROUGH SATURDAY/... ON TUESDAY...COLD FRONT WILL BE SLOW-MOVING OR STALLED ALONG THE EAST COAST...WITH AN UPPER TROUGH APPROACHING FROM THE WEST. GOOD MODEL AGREEMENT OF A WAVE OF LOW PRESSURE DEVELOPING ALONG THE FRONT OVER NORTH CAROLINA. BASED ON THESE FEATURES...COULD SEE SOME LIGHT SHOWER ACTIVITY OVER SOUTHERN AND WESTERN PORTIONS OF THE CWA TUESDAY AFTN THROUGH TUESDAY NIGHT...ALTHOUGH DRY AIR NEAR THE SURFACE COULD INHIBIT ACTIVITY. TEMPS WILL BE COOLER THAN MONDAY...BUT STILL ABOVE NORMAL...WITH HIGHS RANGING FROM THE UPPER 60S OVER HIGHER ELEVATIONS TO THE MID 70S ALONG AND E OF THE I-95 CORRIDOR. TUESDAY NIGHT LOWS RANGE FROM THE LOW 40S OVER THE POTOMAC HIGHLANDS TO THE LOW 50S ALONG AND E OF I-95. UNSETTLED CONDITIONS POSSIBLE MID-LATE WEEK. MODELS BEGIN TO DIVERGE ON SYNOPTIC FEATURES...WITH ECMWF PERSISTING WITH UPPER SHORTWAVES PASSING THROUGH THE REGION AND WEAK LOW PRESSURE TO THE SOUTHEAST. GFS FAVORS AN EARLIER EXIT TO THESE FEATURES WITH A DAY OF HIGH PRESSURE THURSDAY AND A POTENTIAL FRONTAL BOUNDARY REACHING THE AREA FRIDAY. SLT CHC TO CHC POPS IN THE FCST THROUGH THIS PERIOD WITH ABOVE-NORMAL TEMPERATURES. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... BKN MID-LEVEL DECKS FOR MOST AREAS...W/ THE SHOWER ACTIVITY DISSIPATING AND MOVING OFF THE COAST. SKIES WILL GRADUALLY CLEAR OUT HEADING INTO MIDDAY...THOUGH WINDS WILL PICK UP OUT OF THE SW AND GUSTING IN THE 15-25KT RANGE AT TIMES. WINDS WILL DISSIPATE LATER TONIGHT BEFORE PICKING UP AGAIN ON MONDAY. PREDOMINANTLY VFR EARLY NEXT WEEK...WITH A LOW CHANCE FOR A PERIOD OF SUB-VFR CONDS MON NIGHT WITH SHOWERS ASSOCIATED WITH A COLD FROPA. GUSTY SW WINDS LIKELY MONDAY...BECOMING NW TUESDAY. && .MARINE... NEAR CALM WINDS ACROSS ALL BUT THE LOWEST BAY/TP ZONES. THEY WILL PICK UP ACROSS THE REGION BY MID MRNG...BACK INTO LOW-END SCA CRITERIA THRU LATE EVE. A SLY SURGE WILL OCCUR UP THE MAIN CHANNEL OF THE BAY OVERNIGHT...CHANNELING BACK INTO MARGINAL SCA RANGE BEFORE ANOTHER BREEZY DAY ON MONDAY. SCA EXTENDED TO MONDAY WITH GUSTY SW WINDS CONTINUING AS A COLD FRONT APPROACHES THE WATERS FROM THE WEST. COULD ALSO SEE A PERIOD OF SCA GUSTS MONDAY AND INTO TUE MORNING WITH A COLD FROPA AND GOOD PRESSURE GRADIENT BETWEEN HIGH PRESSURE TO THE NW AND WEAK LOW PRESSURE OVER NC. SAT MORNING MODELS CAME IN WITH A LITTLE LESS OF A SURFACE PRESSURE GRADIENT BETWEEN OFFSHORE HIPRES AND LOW PRESSURE OVER THE GREAT LAKES...BUT WINDS ALOFT WILL BE STRONG ENOUGH FOR SCA GUSTS IF THEY MIX WELL ENOUGH. SCA CONDITIONS PSBL AGAIN MONDAY AS A COLD FRONT APPROACHES THE WATERS. AFTERWARDS SUB-SCA CONDITIONS EXPECTED THROUGH MIDWEEK. && .FIRE WEATHER... DEWPOINTS DURING THE DAYTIME HRS WILL BE HIGHER TODAY THAN ANY DAY OVER THE PAST WEEK...BUT SO WILL TEMPS. MARGINAL RED FLAG CONCERNS TODAY. THE HIGHER TEMPS /L-M80S/ AND BREEZY SWLY WINDS WILL KEEP AT LEAST AN ELEVATED RISK FOR WILDFIRES TODAY. ELEVATED RISK OF FIRE WX CONDITIONS AGAIN MONDAY. GUSTY WINDS SW WINDS EXPECTED AHEAD OF AN APPROACHING COLD FRONT. ALTHOUGH MORE MOIST AIR WILL BE ADVECTED INTO THE REGION...UNUSUALLY WARM TEMPS IN THE 80S MAY SUPPORT RH DROPPING TO NEAR 30 PERCENT AT SOME LOCATIONS. FOR THIS REASON...AN ELEVATED RISK OF FIRE WX CONDITIONS CONTINUES. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 6 PM EDT MONDAY FOR ANZ531-532-539-540. SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 6 PM EDT THIS EVENING FOR ANZ530-538. SMALL CRAFT ADVISORY FROM 8 AM TO 6 PM EDT MONDAY FOR ANZ530- 535-536-538-542. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ542. SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ533-534-537- 541-543. SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 6 PM EDT THIS EVENING FOR ANZ535-536. && $$ SYNOPSIS...GMS/KCS NEAR TERM...GMS SHORT TERM...GMS LONG TERM...KCS AVIATION...GMS/KCS MARINE...GMS/KCS FIRE WEATHER...GMS/KCS