000 FXUS62 KMHX 100053 AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 853 PM EDT FRI MAY 9 2008 .SYNOPSIS... A WEAK COLD FRONT WILL SLIDE INTO EASTERN NORTH CAROLINA TONIGHT THEN STALL OVER THE AREA. ANOTHER WEAK COLD FRONT WILL PUSH THROUGH THE AREA ON SATURDAY FOLLOWED BY WEAK HIGH PRESSURE BUILDING IN FROM THE NORTH SATURDAY NIGHT. A WARM FRONT AND ATTENDANT LOW PRESSURE WILL APPROACH FROM THE SOUTHWEST ON SUNDAY...PUSH THROUGH THE AREA SUNDAY EVENING THEN SLOWLY MOVE OFF THE MID ATLANTIC COAST ON MONDAY. HIGH PRESSURE BUILDS OVER THE AREA TUESDAY THEN SLIDES OFFSHORE WEDNESDAY. A COLD FRONT WILL MOVE INTO THE REGION THURSDAY. && .NEAR TERM /THROUGH SATURDAY/... WEAK BOUNDARY RIGHT ALONG THE SOUTHERN COAST AT 00Z THIS EVENING. DESPITE LOADS OF INSTABILITY ON THE 00Z MHX SOUNDING...SHOWER ACTIVITY HAS EITHER MOVED OFFSHORE OR DISSAPATED. AS A RESULT...WILL DROP EVENING POPS. REMAINDER OF FCST REMAINS UNCHANGED. SOME PATCHES OF FOG PSBL TOWARD MORNING. && .SHORT TERM /SATURDAY NIGHT/... WEAK SHORT WAVE AND ATTENDANT SFC COLD FRONT WILL PUSH THRU THE AREA ON SATURDAY BUT SYSTEM LACKING DEEP MOISTURE AND ADEQUATE FORCING WHICH SUGGS LTL IF ANY PCPN FOR MUCH OF THE AREA. HAVE A SLIGHT CHC POP OVR NE FCST AREA IN CASE AN AFTN SHWR POPS UNDER THE BETTER INSTABILITY WITH SHORT WAVE PASSING OFF MID ATLC COAST. SUNNY INTERVALS/SEASONABLE TEMPS THE MAIN HIGHLIGHTS OF THE DAY. HIGH PRES/MID LVL RIDGING TEMPORARILIY BUILD INTO THE REGION SAT NIGHT. CLEARING SKIES AND DECREASING WINDS WILL ALLOW DECENT RADIATIONAL COOLING WITH LOWS MAINLY M-U50S. POTENTIAL FOR AN ACTIVE SUNDAY AFTN/EVE ACRS THE AREA AS UPR LOW DIVES SE FM OHVLY. SHEAR/HELICITY WILL BE MAXIMIZED BY SFC LOW/WARM FRONT LIFTING NE THRU THE AREA. MARGINAL INSTABILITY MAY BE LIMITING FACTOR FOR WIDESPREAD SVR WEATHER BUT MOST PARAMETERS POINT TO AN ACTIVE DAY. TEMPS WILL BE HELP DOWN BY CLOUD COVER WITH HIGH REACHING THE BLO NORML L-M70S. STRONG CONVENTION WILL PUSH OFFSHORE WITH FRONT DURING THE EVENING HOURS. MOD TO STRONG WESTERLY FLOW WILL MITIGATE LOW LVL CAA WITH LOWS MAINLY M50S/L60S. && .LONG TERM /SUNDAY THROUGH FRIDAY/... WRAPARND MOISTURE AND WEAK VORT LOBE ROTG ABOUT THE UPR LOW OFF DELMARVA WL HELP ROTATE CLOUDS AND PSBLY A FEW SHWRS ACRS THE AREA MONDAY. OTRW A WIND/COOLISH DAY WITH HIGHS ARND 70. SFC HIGH PRES/HIGH AMPLITUDE UPR RDG GRADUALLY BUILD EAST AND BRING A RETURN TO DRIER CONDS AND MODERATING TEMPS TUE/WED. NEXT SYSTEM MOVES EAST OF THE MSVLY THU AND BRINGS BACK PCPN CHCS. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... LOOKS LIKE CHANCES FOR ADDITIONAL CONVECTION OVERNIGHT SLIM OR NIL AS INSTABILITY WILL BE DECREASING. WEAK BOUNDARY WILL DRIFT SOUTH OF THE AREA OVERNIGHT WITH A BRIEF SURGE IN WINDS LATE THIS EVENING THEN WINDS DECOUPLING LATE. WITH LOW LEVEL FLOW FORECAST TO BECOME EAST OVERNIGHT THERE IS SOME CONCERN FOR FOG/STRATUS AND IFR/LIFR CONDITIONS AFTER 08Z. THE AVIATION GUIDANCE IS SUGGESTING A PERIOD OF THIS LATE AND SO DID PREVIOUS FORECASTS SO CONTINUED TREND IN THE 00Z TAFS. THE FRONT WILL RETURN TO THE NORTH SATURDAY AS WEAK LOW PRESSURE DEVELOPS OVER THE AREA. CAN'T'T RULE OUT A FEW STRAY THUNDERSTORMS BUT MOISTURE AND FORCING WILL BE LACKING SO NO MENTION IN THE TAFS. THE FRONT WILL SURGE TO SOUTH LATE SATURDAY AFTERNOON WITH DRY WEATHER AND VFR CONDITIONS PREVAILING INTO SUNDAY MORNING. EXCEPTION WILL BE LATE SATURDAY NIGHT WHEN ANOTHER PERIOD OF FOG AND/OR STRATUS WILL BE POSSIBLE. ANOTHER ROUND OF STRONG TO SEVERE STORMS WILL BE POSSIBLE SUN AFT THROUGH EVENING...FOLLOWED BY STRONG NW WINDS WITH VFR CONDITIONS ON MON. && .MARINE... THE COLD FRONT IS BEGINNING TO DRIFT SOUTH OF THE WATERS THIS EVENING AND WILL DRIFT THROUGH OR STALL ACROSS THE SOUTHERN WATERS AFTER MIDNIGHT. INITIALLY THERE WILL BE A SURGE IN NORTH WINDS TO 20 KT FOLLOWING THE FRONT BUT SPEEDS WILL DIMINISH TO 15 KT OR LESS AFTER 8Z. THE FRONT WILL PUSH BACK NORTH SATURDAY AS WEAK LOW PRESSURE FORMS OVER EASTERN NC. WINDS FOR MOST OF SATURDAY WILL BE 15 KT OR LESS WITH THE DIRECTION DEPENDING ON WHICH SIDE OF THE FRONT YOU ARE ON (EASTERLY NORTH/WESTERLY SOUTH). LATE IN THE AFTERNOON AFTER 20Z...THE FRONT WILL SURGE SOUTH OF THE WATERS AS THE LOW MOVES OFFSHORE AND WINDS WILL SHIFT TO NORTH AND INCREASE TO 20 IF NOT BRIEFLY TO 25 KT. SUBSEQUENT FORECASTS MAY NEED TO BEEF UP WINDS AND SEAS SATURDAY EVENING. WINDS WILL THEN DIMINISH AND BECOME E/SE AFTER MIDNIGHT SATURDAY NIGHT. I HAVE ALLOWED THE ADVISORIES FOR THE SOUNDS TO EXPIRE AT 8 PM BUT WILL CONTINUE THEM OVER THE WATERS OVERNIGHT MAINLY FOR SEAS AFT 06Z. A SECOND LOW WILL SLIDE S AND OFFSHORE SAT NIGHT WITH A BRIEF N/NW SURGE AROUND 20KT. WINDS WILL DROP BACK DOWN...AND THEN SWITCH TO THE SE BY SUN AFT. AN APPROACHING STORM SYSTEM WILL MOVE TOWARDS THE AREA ON SUN. THE GFS...THE PREFERRED MODEL...SHOWS THE LOW ALONG THE ILM COAST BY SUN NT...WHILE THE ECMWF HAS THE CENTER MORE N OVER THE CENTRAL NC/VA BORDER. THE WIND SPEEDS ARE SIMILAR...JUST A DIFFERENCE IN DIRECTION BASED ON THE CENTER OF THE SFC LOW. WILL CONTINUE USING THE GFS WHICH SHOWS WINDS INCREASING OUT OF THE SE...AND THEN SWITCHING TO THE W/NW AS THE LOW MOVES OFF THE N OBX SUN NT. THE NW WINDS ON THE BACKSIDE OF THIS STRENGTHENING SYSTEM WILL LIKELY REACH STRONG SCA TO GALE FORCE ACROSS THE COASTAL WATERS. AND WITH STRONG MIXING POTENTIAL ON MON...WILL SEE GUSTY WINDS INLAND. THE WINDS WILL GRADUALLY DROP OFF INTO TUE...BUT LOOK FOR SOME LINGERING SWELL OUT OF THE N TO KEEP SEAS UP N OF HATTERAS. SINCE OPC WAS NOT FAVORING THE STORM FORCE WINDS OFFSHORE OF THE GFS...AND SUBSEQUENTLY LOWERED WAVEWATCH SEAS LATER IN THE FORECAST HAS FOLLOWED THEIR LEAD. HOWEVER...HAVE KEPT SCA SEAS THROUGH MID WEEK UP N. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR AMZ152-154. SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR AMZ156-158. SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR AMZ150. && $$ SYNOPSIS...BTC NEAR TERM...CTC SHORT TERM...BTC LONG TERM...BTC AVIATION...JME/SJ MARINE...JME/SJ