000 FXUS61 KOKX 120336 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE UPTON NY 1136 PM EDT SAT OCT 11 2008 .SYNOPSIS... HIGH PRESSURE WILL BUILD OVER THE NORTHEAST THIS WEEKEND. A BACK DOOR COLD FRONT WILL THEN MOVE THROUGH MONDAY...AND THEN LIFT BACK NORTH OF THE AREA AS A WARM FRONT LATE MONDAY NIGHT INTO TUESDAY MORNING. A SERIES OF COLD FRONTS WILL MOVE ACROSS DURING THE MID WEEK PERIOD...WITH UNSETTLED WEATHER POSSIBLY CONTINUING INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... FCST LOOKING GOOD. WILL UPDATE HOURLY GRIDS BASED ON LATEST SFC OBS AND SAT IMG. JUST SOME THIN...WISPY CIRRUS ACROSS THE HUDSON VALLEY...BUT WILL GO AHEAD AND CARRY CLEAR SKIES THROUGHOUT. NO CHANGES TO THE OVERNIGHT LOWS...WHICH SHOULD BOTTOM OUT AROUND 50-55 IN NYC AND THE IMMEDIATE SUBURBS...AND 40S MOST ELSEWHERE...WITH UPPER 30S IN WESTERN ORANGE COUNTY AND THE COLDEST SPOTS OF THE LONG ISLAND PINE BARRENS. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... FINE FALL WX SHOULD CONTINUE THROUGH MUCH IF NOT ALL THE PERIOD. THE BIG PICTURE SHOWS AN AMPLIFYING UPPER LEVEL RIDGE OVER MOST OF THE EASTERN HALF OF THE NATION...WITH A DEEP CUTOFF LOW OVER THE WEST SHEARING OUT PIECEMEAL EARLY NEXT WEEK...AND A SERIES OF SHORTWAVES SPILLING OVER THE RIDGE INTO NORTHERN NEW ENGLAND AND THE CANADIAN MARITIMES. THE FIRST OF THESE. SHORTWAVES...NOW ENTERING NORTHERN MAINE...WILL HELP DRIVE A LOBE OF SURFACE HIGH PRESSURE SOUTHWARD ACROSS THE AREA ON SUNDAY VIA MID LEVEL CONFLUENCE IN ITS WAKE. THIS WAVE WILL DIG INTO THE BASE OF AN ALREADY AMPLIFYING LONG WAVE TROUGH SE OF NOVA SCOTIA...ENABLING A SECOND SHORTWAVE STILL NEAR HUDSON BAY TO DIG SE AND SEND A BACK DOOR COLD FRONT THROUGH THE AREA ON MONDAY. TEMPS SHOULD WARM UP DURING THE PERIOD...WITH LOWER/MID 70S IN MOST PLACES EXCEPT FAR EASTERN CT/LONG ISLAND ON SUNDAY...AND THEN A FEW DEGREES WARMER JUST AHEAD OF THE BACK DOOR FRONT ON MONDAY...WITH LOWER 80S IN NORTHEAST NJ AND 70S ELSEWHERE. IT NOW APPEARS THAT THE BACK DOOR FRONT WILL LIFT QUICKLY NORTHEAST LATE MON NIGHT INTO EARLY TUE MORNING...BUT UNTIL IT DOES... RELATIVELY MOIST LOW LEVEL ONSHORE FLOW BENEATH A SHALLOW FRONTAL INVERSION SHOULD LEAD TO DEVELOPMENT OF LOW STRATUS AND FOG LATE MON NIGHT INTO TUE MORNING ACROSS MOST OF LONG ISLAND AND SOUTHERN CT. RETURN OF SW FLOW THEREAFTER COULD LEAD TO ANOTHER VERY MILD DAY ON TUE...WITH TEMPS SIMILAR TO IF NOT WARMER THAN THOSE OF MON...BUT THIS WILL ULTIMATELY DEPEND ON AMOUNT OF HIGH/MID LEVEL CLOUDS SPILLING OVER THE UPPER RIDGE TO THE WEST AHEAD OF AN APPROACHING COLD FRONT. THINK GFS MAY BE TOO FAST IN THIS REGARD...AND HAVE LEANED TOWARD MORE AFTERNOON SUNSHINE AND WARMER TEMPS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A SOMEWHAT UNSETTLED WEATHER PATTERN LOOKS TO RETURN BY MID WEEK ALTHOUGH EXPECT MORE IN THE WAY OF CLOUD COVER THAN PRECIP UNTIL POSSIBLY LATE IN THE WEEK. ALTHOUGH THE GFS IS TRENDING TOWARDS THE ECMWF...IT CONTINUES TO BE THE FAST OUTLIER IN THE MEDIUM RANGE AND HAS BEEN DISCOUNTED. GENERALLY FOLLOWED HPC GUIDANCE WHICH IS COMPRISED OF THE 00Z ECMWF AND ECMWF ENS MEAN. A COLD FRONT ASSOCIATED WITH A CLOSED LOW PRESSURE SYSTEM MOVING ACROSS HUDSON/JAMES BAY AND INTO THE LABRADOR SEA WILL APPROACH FROM THE NORTH ON WED. AN OFFSHORE LOW BLOCKING THE UPPER PATTERN WILL CAUSE THIS FRONT TO SLOWLY MOVE ACROSS THE AREA WED AFTN AND EVENING. MID LEVEL ENERGY APPEARS MINIMAL...BUT WOULD NOT BE SURPRISED IF SOMETHING WAS SQUEEZED OUT. ANOTHER LOW GENERALLY FOLLOWS THE SAME TRACK ON WED NIGHT AND THU ALTHOUGH UPPER TROUGH AND DYNAMICS WEAKEN AS A LARGE RIDGE OVER THE SE FORCES THE UPPER FLOW OVER THE NORTHERN CONUS TO FLATTEN. THIS SYSTEMS COLD FRONT IS FORECAST TO MOVE ACROSS THE AREA DURING THE DAY THU WITH A RETURN TO FALL EXPECTED BEHIND IT. A DEVELOPING COASTAL SYSTEM MAY AFFECT THE AREA LATE IN THE PERIOD...HOWEVER THE 12Z ECMWF HAS TRENDED FURTHER SOUTH. TEMPERATURES WILL START OFF ABOVE NORMAL...BUT RETURN BACK TO SEASONABLE LEVELS AFTER THE COLD FROPA ON THU. && .AVIATION /04Z SUNDAY THROUGH THURSDAY/... UNLIMITED CIGS/VSBYS THROUGH THE TAF PERIOD. L/V WINDS IN PLACE THROUGH LATE SUN...THOUGH E-NE WINDS WILL AVG 5-7 KT AFTER 13Z. BY 20Z...WINDS WILL TURN SE WITH LOCAL SEABREEZE DEVELOPMENT. OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY... VFR WITH LARGE RIDGE IN CONTROL. SUB-VFR CONDITIONS ARE POSSIBLE IN FOG AND/OR LOW STRATUS VIA AN ONSHORE FLOW MON NIGHT INTO TUE MORNING...MAINLY ACROSS LONG ISLAND AND CT TERMINALS. A COLD FRONTAL PASSAGE IS POSSIBLE LATE WEDNESDAY INTO WEDNESDAY NIGHT WITH A CHANCE OF SHOWERS. ................................................... TAF CODE IS CHANGING NOVEMBER 5TH AT 00Z... PLEASE SEE... HTTP:/AVIATIONWEATHER.GOV/NOTICE/TAF30.PHP (LOWER CASE) ................................................... && .MARINE... QUIET THROUGH MOST OF THE PERIOD. ONLY CONCERNS ATTM ARE POSSIBLE REDUCED VSBY IN FOG LATE MON NIGHT INTO TUE MORNING VIA RELATIVELY MOIST ONSHORE FLOW...AND POSSIBLE SCA CONDITIONS THU NIGHT ON THE EASTERN OCEAN WATERS...AS THE PRESSURE GRADIENT TIGHTENS IN THE WAKE OF A COLD FRONTAL PASSAGE...AND AS LOW PRESSURE OVER THE WESTERN ATLANTIC INTENSIFIES. && .HYDROLOGY... NO SIGNIFICANT RAINFALL IS EXPECTED THROUGH NEXT SAT...SO RIVERS AND STREAMS SHOULD CONTINUE TO SLOWLY RECEDE. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...AL/BG NEAR TERM...MPS SHORT TERM...BG LONG TERM...AL AVIATION...MPS MARINE...AL/BG HYDROLOGY...BG