Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 281126 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 726 AM EDT SAT MAR 28 2015 .SYNOPSIS... LOW PRESSURE WELL EAST OF THE NEW JERSEY COAST DEEPENS AND TRACKS NORTHEAST THROUGH TONIGHT...REACHING THE CANADIAN MARITIME. HIGH PRESSURE BUILDS INTO THE REGION 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/... LOW PRESSURE WAS CENTERED WELL EAST OF THE DELMARVA...SOUTHEAST OF THE BENCHMARK...THIS MORNING AND CONTINUES TO TRACK NORTHEAST THROUGH TODAY AS THE BROAD AND NEARLY FULL LATITUDE UPPER TROUGH MOVES EAST TOWARD THE COAST. THE PRECIPITATION SHIELD HAS NOW SPREAD A LITTLE FARTHER TO THE WEST INTO CENTRAL AND EASTERN LONG ISLAND...AND INTO MIDDLESEX AND NEW LONDON COUNTIES OF CONNECTICUT. A VIGOROUS VORT MAX WAS ROTATING INTO THE TROUGH AND WAS MOVING OFF THE NORTH CAROLINA COAST AS SEEN ON THE WATER VAPOR. PRECIPITATION WILL BECOME MORE WIDESPREAD EARLY THIS MORNING...AND ESPECIALLY ACROSS THE EAST AS THIS VORT MAX MOVES THROUGH THE EASTERN POTION OF THE TROUGH. HAVE LIMITED THE WESTWARD EXTENT OF HIGHER POPS TODAY. ALL MODEL PROFILES INDICATE LIGHT SNOW FOR THE EVENT. WITH THE LOW A LITTLE DEEPER AND CLOSER TO THE REGION...NORTHWEST FLOW HAS INCREASED ALONG WITH GUSTS. && .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 /11Z SATURDAY THROUGH WEDNESDAY/... SURFACE LOW PRESSURE WILL PASS WELL TO THE SOUTH AND EAST TODAY. MEANWHILE...AN UPPER LEVEL DISTURBANCE AND WEAK SURFACE LOW PRESSURE TROUGH WILL MOVE ACROSS THE REGION. VFR CONDITIONS AT MOST TERMINALS TO START. CIGS AT KGON ARE MVFR AND ARE EXPECTED TO FALL TO TO IFR BY 15Z. CIGS ARE EXPECTED TO FALL TO MVFR AT KISP AND KBDR IN SNOW BETWEEN 12Z-14Z. PRECIPITATION SHOULD GENERALLY BE SNOW THROUGH THE EVENT EXCEPT AT KGON WHERE THE PRECIP HAS STARTED AS RAIN. RUNWAY ACCUMULATION OF 1-3 INCHES IS FORECAST FOR EAST OF NYC. THE REST OF THE TERMINALS SHOULD REMAIN VFR THROUGH MUCH OF THE TAF PERIOD...ALTHOUGH A BRIEF PERIOD OF MVFR IS NOT OUT OF THE QUESTION IN ANY LIGHT SNOW THAT DEVELOPS. WINDS INCREASE AS THE PRESSURE GRADIENT TIGHTENS WITH THE OFFSHORE LOW DEEPENING AND GUSTS SHOULD DEVELOP. EXPECT GUSTS INTO THE 20-25 KT RANGE. A FEW OCCASIONAL GUSTS COULD EXCEED 25 KT. .OUTLOOK FOR 12Z SUN THROUGH WED... .SUNDAY...VFR. .MON...VFR. W WINDS G20KT. .TUE...VFR. .TUE NIGHT...CHANCE OF MVFR CONDITIONS WITH ANY RAIN SHOWERS. .WED...VFR. && .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 FROM 4 PM THIS AFTERNOON TO 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...MET SHORT TERM...MET LONG TERM...DW AVIATION...BC MARINE...MET HYDROLOGY...MET

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