Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 281804 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 204 PM EDT SAT MAR 28 2015 .SYNOPSIS... LOW PRESSURE WELL EAST OF LONG ISLAND THIS AFTERNOON TRACKS NORTHEAST THROUGH TONIGHT...REACHING THE CANADIAN MARITIMES. HIGH PRESSURE BUILDS INTO THE REGION LATE TONIGHT INTO SUNDAY... FOLLOWED BY A SERIES OF FRONTAL SYSTEMS THAT WILL IMPACT THE AREA THROUGH THE UPCOMING WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WITH AN APPROACHING UPPER LOW OVER CENTRAL PA/NY...THERE WILL BE A PERSISTENT AREA OF WEAK TO MODERATE LIFT ACROSS THE TRI-STATE AREA WITH EMPHASIS TO THE EAST OF NYC AND THE LOWER HUDSON VALLEY. THIS WILL MEAN A CONTINUATION OF MAINLY LIGHT SNOW. THERE ARE NO PLANS FOR A WINTER WEATHER ADVISORY AT THIS TIME WITH ROADWAYS MAINLY CLEAR OF SNOW. A GUSTY NW FLOW WILL CONTINUE AS WELL WITH DEEPENING LOW PRESSURE WELL OFFSHORE AND HIGH PRESSURE OVER THE GREAT LAKES BUILDING EAST. TEMPS WILL HOLD STEADY IN THE LOW TO MID 30S ACROSS LI AND CT...BUT IT WILL BE WARMER ACROSS NE NJ/NYC WHERE THE BACK EDGE OF THE CLOUDS RESIDE. AMAZINGLY...TEMPS ARE ABOUT 15 TO 20 DEGREES BELOW NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... THE UPPER TROUGH MOVES OVER THE REGION BY 00Z SUNDAY WITH THE INTENSIFYING VORT MOVING SOUTH AND EAST OF THE REGION. THIS DEEPENS THE SURFACE LOW WHICH WILL PASS SOUTH AND EAST OF THE 40N 70W BENCHMARK. AGAIN ENOUGH COLD AIR WILL BE IN PLACE BEHIND THIS LOW FOR THE PRECIPITATION TO BE ALL LIGHT SNOW. WITH THE LOW PASSING WELL TO THE SOUTH AND EAST HAVE CUT BACK OF THE WESTWARD AND NORTHWARD EXTENT OF THE POPS WITH INLAND AREAS RECEIVING LITTLE PRECIPITATION. LIQUID TO SNOW RATIOS AROUND 1 TO 10 AND WITH AROUND A THIRD OF AN INCH MAINLY ACROSS NEW LONDON COUNTY...COULD SEE 2 TO 3 INCHES OF SNOW HERE...AND CLOSE TO WPC SNOW AMOUNTS. PRECIPITATION ENDS SLOWLY FROM WEST TO NORTHEAST LATE IN THE DAY AND INTO TONIGHT AS THE SURFACE LOW TRACKS NORTHEAST TOWARD THE CANADIAN MARITIME AND THE UPPER TROUGH AXIS MOVES OFF THE COAST 06Z TO 12Z SUNDAY...WITH HEIGHTS QUICKLY BUILDING. SUNDAY REMAINS DRY WITH UPPER RIDGE AXIS OVER REGION BY 00Z MONDAY...AND THE SURFACE HIGH SLIDING TO THE SOUTH. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... A PROGRESSIVE...YET AMPLIFIED FLOW IS BEING ADVERTISED BY THE GLOBAL MODELS THROUGH NEXT WEEK. INITIALLY...A SERIES OF FAST MOVING PAC SYSTEMS RIDE OVER TOP THE RIDGE OVER WESTERN NORTH AMERICA... DROPPING SE ACROSS CENTRAL CANADA AND INTO THE NE QUARTER OF THE NATION. HOWEVER...TOWARD THE END OF THE WEEK...THERE ARE TIMING AND MAGNITUDE DIFFERENCES WITH PAC ENERGY MOVING INTO THE WEST COAST OF THE LOWER 48. THE 12Z ECMWF FOCUSES ON A TRAILING SECOND PIECE OF ENERGY...THUS SLOWING DOWN THE FRONTAL SYSTEM AT THE END OF NEXT WEEK. FOR THE TIME...WILL MAINTAIN A LOW CHANCE OF RAIN SHOWERS THU AND FRI WITH THE POSSIBILITY THAT THIS SYSTEM MAY BE SLOWER THAN CURRENTLY ADVERTISED. THE OTHER SYSTEM THAT MAY BE NOTEWORTHY IS A CLIPPER LOW THAT THE 12Z GFS TAKES JUST NORTH OF NYC AND LI TUE NIGHT...WHILE THE ECMWF IS SIGNIFICANTLY FARTHER SOUTH EMERGING OFF THE MID ATLANTIC COAST. THE LATTER SCENARIO HAS SOME SUPPORT FROM THE GEFS. THIS COULD RAISE CONCERNS FOR SOME WINTRY WEATHER...ESPECIALLY INLAND. FOR NOW...GOING WITH AN ALL RAIN FORECAST BASED ON CLIMO AND MODEL UNCERTAINTY. A MUCH WEAKER COLD FRONT WILL MOVE ACROSS THE AREA MON WITH PERHAPS A FEW SHOWERS. AFTER AN UNSEASONABLY COLD START ON SUN WITH HIGHS 40 TO 45...BOTH HIGHS AND LOWS WILL REBOUND TO NEAR SEASONABLE LEVELS. THE ONE CAVEAT IS A FARTHER SOUTH STORM TRACK TUE NIGHT INTO WED. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... LIGHT SNOW CONTINUES ACROSS NYC/NORTHEAST NJ/LOWER HUDSON VALLEY TERMINALS WITH SOME MVFR TO LOCALIZED IFR CONDS WHILE LIGHT TO MODERATE SNOW CONTINUES OVER CT/LONG ISLAND WITH A BIT MORE WIDESPREAD IFR AND LOWER CONDS. SNOW TAPERS OFF FROM WEST TO EAST GOING THROUGH THIS EVENING...AND CONDS WILL LIFT TO VFR ACROSS THE REGION. NW WINDS ACROSS THE TERMINALS WILL RANGE FROM 10-20 KT WITH GUSTS UP TO 25 KT. WINDS DIMINISH TO 10-15 KT SUNDAY MORNING...AND THEN WILL GRADUALLY BACK TO THE WEST IN THE AFTERNOON. .OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY... .SUNDAY AFTERNOON...VFR. NW WINDS...BACKING TO THE SW. .SUNDAY NIGHT...VFR. .MONDAY...VFR. WEST WINDS 10-15 KT WITH GUSTS UP TO 20 KT. .MONDAY NIGHT-TUESDAY...VFR. .TUESDAY NIGHT...MVFR OR LOWER CONDS IN -RA. .WEDNESDAY...VFR. .THURSDAY...MVFR OR LOWER CONDS IN -RA. && .MARINE... FORECAST ON TRACK...WIND AND GUSTS A FEW KNOTS HIGHER THAN FORECAST WITH THE LOW OFF THE DELMARVA AND DEEPENING QUICKLY. A SMALL CRAFT ADVISORY ON THE OCEAN WATERS REMAINS WITH SEAS 5 FT OR MORE...IN ADDITION AS LOW PRESSURE PASSES SOUTH AND EAST TODAY WHILE DEEPENING...WIND AND GUSTS WILL INCREASE TO SMALL CRAFT LEVELS ACROSS ALL THE FORECAST WATERS. GUSTY NORTHWEST SMALL CRAFT WIND CONTINUES INTO TONIGHT AS THE LOW MOVES INTO THE CANADIAN MARITIME AND HIGH PRESSURE BUILDS TO THE WEST. SMALL CRAFT GUSTS MAY LINGER INTO EARLY SUNDAY MORNING ACROSS THE EASTERN WATERS...HOWEVER GUSTS DIMINISH AS HIGH PRESSURE BUILDS TO THE WEST. THE SMALL CRAFT ON THE OCEAN WATERS WAS EXTENDED THROUGH SUNDAY FOR LINGERING SEAS...AND THE SMALL CRAFT ON THE REMAINDER OF THE WATERS REMAINS IN EFFECT TONIGHT. WAVES DIMINISH TO SUB SCA ON SUNDAY...BUT BUILD TO ABOVE SCA CRITERIA ON A SOUTHERLY FLOW LATE SUNDAY NIGHT INTO MONDAY AHEAD OF AN APPROACHING WARM FRONT. WINDS MAINLY OVER THE OCEAN WATERS WILL GUST TO 25 KT LATE SUNDAY NIGHT INTO MONDAY NIGHT. WINDS AND WAVES WILL DIMINISH ON TUESDAY AS THE PRESSURE GRADIENT RELAXES WITH WEAK HIGH PRESSURE BUILDING IN. THERE IS THE POTENTIAL FOR MARGINAL SCA CONDITIONS TUE NIGHT INTO WED MORNING DEPENDING ON THE TRACK AND INTENSITY OF LOW PRESSURE NEAR THE WATERS. LEANING TOWARD SUB-SCA CONDITIONS AT THIS TIME. && .HYDROLOGY... A FEW HUNDREDTHS TO A THIRD INCH LIQUID EQUIVALENT QPF IS EXPECTED THROUGH TONIGHT...WITH LITTLE TO NONE ACROSS PORTIONS OF THE LOWER HUDSON VALLEY AND INTO NORTHEASTERN NEW JERSEY AND THE HIGHEST AMOUNTS ACROSS THE TWIN FORKS AND NEW LONDON COUNTY. THE PRECIPITATION FALLS AS SNOW. NO SIGNIFICANT WIDESPREAD PRECIPITATION IS FORECAST SUNDAY INTO NEXT WEEK. RIVERS AND STREAMS ARE EXPECTED TO REMAIN BELOW BANK FULL...BUT INCREASED RIVER/STREAM FLOW ACROSS THE LOWER HUDSON VALLEY AND SOUTHERN CONNECTICUT WILL CONTINUE ICE BREAKUP AND MOVEMENT INTO THIS WEEKEND. ISOLATED ICE JAMS ARE POSSIBLE...WHICH IF THEY OCCUR...COULD RESULT IN LOCALIZED FLOODING. SINCE ICE JAM FLOODING IS UNPREDICTABLE AND SUDDEN...INTERESTS ALONG ICE COVERED RIVERS SHOULD MONITOR NWS FORECASTS FOR THE LATEST INFORMATION. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB SITE. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ338. SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EDT SUNDAY FOR ANZ330-335-340-345. SMALL CRAFT ADVISORY UNTIL 6 PM EDT SUNDAY FOR ANZ350-353-355. && $$ SYNOPSIS...MET NEAR TERM...DW SHORT TERM...MET LONG TERM...DW AVIATION...MPS MARINE...MET HYDROLOGY...MET

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