Area Forecast Discussion
Issued by NWS Upton, NY

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KOKX 181948 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 348 PM EDT SAT APR 18 2015 .SYNOPSIS...
-- Changed Discussion --
A COLD FRONT WILL CROSS THE TRI-STATE THROUGH EARLY THIS EVENING....FOLLOWED BY HIGH PRESSURE BUILDING TO THE NORTH INTO SUNDAY MORNING. THIS HIGH SLIDES TO THE EAST INTO SUNDAY NIGHT...ALLOWING A WARM FRONT TO APPROACH FROM THE SOUTH SUNDAY NIGHT AND MONDAY...LIKELY MOVING THROUGH SOMETIME LATE MONDAY OR MONDAY NIGHT. A COLD FRONT PASSES TUESDAY. A SERIES OF WEAK COLD FRONTS AND/OR TROUGHS OF LOW PRESSURE WILL MOVE THROUGH DURING THE MID TO LATE WEEK PERIOD.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
-- Changed Discussion --
DEEP LAYERED RIDGING BUILDS IN FROM THE WEST TONIGHT. ASSOCIATED SUBSIDENCE AND DOWNSLOPE FLOW SHOULD KEEP THINGS DRY AND PROMOTE MINIMAL CLOUD COVER TONIGHT. LOWS TONIGHT WERE BASED ON A BLEND OF MAV/MET/ECS GUIDANCE AND SHOULD BE A FEW TO FIVE DEGREES ABOVE NORMAL. IT IS UNCERTAIN HOWEVER...EXACTLY HOW MUCH DECOUPLING WILL OCCUR DURING THE OVERNIGHT HOURS...ESPECIALLY OVER WESTERN ZONES. IF MORE DECOUPLING OCCURS THEN CURRENTLY EXPECTED - THEN WOULD NEED TO LOWER LOWS WHERE THIS OCCURS BY 5 DEGREES OR SO.
-- End Changed Discussion --
&& .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
-- Changed Discussion --
DEEP LAYERED RIDGING CONTINUES TO BUILD OVER THE AREA SUNDAY...WITH ITS RIDGE AXIS LOCATED NEAR THE HUDSON RIVER BY AROUND 00Z MONDAY. COULD SEE A FEW HIGH CLOUDS BUILD IN OVER WESTERN ZONES IN THE AFTERNOON AS A RESULT...OTHERWISE THERE SHOULD BE LITTLE IF ANY IN THE WAY OF CLOUD COVER SUNDAY. HIGHS ON SUNDAY WERE BASED ON A BLEND OF MIXING DOWN FROM 900-875 HPA PER BUFKIT SOUNDINGS WITH NAM 2-METER TEMPERATURES AND A BLEND OF MAV...MET AND ECS GUIDANCE. HIGHS SHOULD BE NEAR TO SLIGHTLY BELOW NORMAL. HAVE KEPT THINGS DRY THROUGH SUNDAY EVENING DUE TO SUBSIDENCE UNDER DEPARTING RIDGE. SHOULD THEN HAVE SUFFICIENT WARM ADVECTION/ISENTROPIC UPGLIDE LATE SUNDAY NIGHT TO WARRANT POPS FROM CHANCE EASTERN ZONES (SLIGHT CHANCE FAR E NEW LONDON COUNTY) TO CATEGORICAL OVER ROUGHLY THE WESTERN 1/4 OF THE CWA AFTER 6Z. WITH A 45-55 KT LOW LEVEL JET FORECAST TO IMPINGE ON THE CWA BY LATE SUNDAY NIGHT...SHOULD SEE SOME MODERATE...TO POSSIBLY LOCALLY HEAVY RAINFALL IN AREAS WITH CATEGORICAL POPS LATE SUNDAY NIGHT. FOR NOW...BELIEVE MARINE INVERSION WILL KEEP MOST IF NOT ALL OF THE LOW LEVEL JET ALOFT SUNDAY NIGHT...WITH STRONGEST WINDS NEAR THE COAST. GUSTS SHOULD BE 25 MPH OR LESS...WITH LITTLE IF ANY GUSTING OVER N INTERIOR ZONES. FOR LOWS SUNDAY NIGHT USED A BLEND OF MAV/MET/ECS GUIDANCE WITH NAM 2-METER TEMPERATURES...WITH NEAR NORMAL TEMPERATURES FORECASTED.WOULD EXPECT A NON-DIURNAL TEMPERATURE TREND...ESPECIALLY AFTER MIDNIGHT GIVEN DEVELOPING STRONG LOW LEVEL WARM ADVECTION THEN.
-- End Changed Discussion --
&& .LONG TERM /MONDAY THROUGH SATURDAY/...
-- Changed Discussion --
THIS MEDIUM RANGE PERIOD WILL FEATURE A FULL LATITUDE TROUGH... UPPER LEVEL LOW WHICH SLOWLY TRAVERSES FROM THE GREAT LAKES REGION ACROSS THE NORTHEAST. SPLIT FLOW OUT WEST...AND EVENTUAL PACIFIC NW ENERGY SHOULD KICK THIS UPPER LOW OVER THE NORTHEAST OUT BY NEXT WEEKEND. AT THE SURFACE...WARM FRONT APPROACHES MONDAY...WITH A WEAK WAVE OF LOW PRESSURE...TRIPLE POINT NEARING THE AREA. WITH THE MAIN SFC LOW FAR TO THE WEST CLOSER TO THE UPPER TROUGH...WARM FRONT MAY HAVE A HARD TIME MOVING THROUGH UNTIL RIGHT BEFORE THE COLD FRONTAL PASSAGE...WHICH LOOKS TO OCCUR EARLY TUESDAY. THE AREA WILL REMAIN BETWEEN HIGH PRESSURE TO THE SOUTH AND LOW PRESSURE TO THE NORTH THROUGH WEDNESDAY. ANOTHER COLD FRONT APPROACHES WED NIGHT AND MOVES THROUGH THURSDAY...AS UPPER ENERGY ROUNDS THE BASE OF THE LOW. AS FOR SENSIBLE WEATHER...RAIN MOVES IN AHEAD OF THE WARM FRONT/SFC WAVE. STRENGTHENING LOW LEVEL JET WILL RESULT IN MODERATE TO POSSIBLY HEAVY RAIN FOR A TIME MONDAY...WITH PLENTY OF LIFT OVER THE COOLER AIR AT THE SFC. ATLANTIC AND GULF MOISTURE IS TAPPED WITH THIS SYSTEM...SO WOULD EXPECT SIGNIFICANT RAINFALL. ELEVATED INSTABILITY NOTED AS WELL LATE MONDAY AND MONDAY NIGHT. WILL ADD IN ISOLATED THUNDER AND PATCHY FOG AS THE WARM FRONT SITS NEARBY. THEREAFTER...GENERALLY DRY WEATHER RETURNS...ALTHOUGH HARD TO LEAVE OUT POPS LATE IN THE WEEK DUE TO PRESENCE OF UPPER LOW/COLD POOL. BEST CHANCE THOUGH FOR ADDITIONAL RAIN LOOKS TO BE WED NIGHT INTO EARLY THURSDAY AHEAD OF THE COLD FRONT. TEMPS SHOULD REMAIN SLIGHTLY BELOW NORMAL MONDAY PER MOS...ASSUMING WARM FRONT REMAINS SOUTH. SEASONABLE TEMPS ARE EXPECTED TUESDAY...WITH A GRADUAL COOLING TREND THEREAFTER. FOLLOWED MEX/GRIDDED MOS AND WPC NUMBERS THROUGH MUCH OF THIS TIME FRAME.
-- End Changed Discussion --
&& .AVIATION /19Z SATURDAY THROUGH THURSDAY/...
-- Changed Discussion --
A COLD FRONT PASSES THROUGH THIS EVENING FOLLOWED BY HIGH PRESSURE BUILDING OVER THE TERMINALS INTO SUNDAY MORNING. VFR THRU THE TAF PERIOD. W-WNW WINDS 10 TO 15 KT THIS AFTERNOON WITH GUSTS 20 TO 25 KT AWAY FROM THE COAST. S-SW SEA BREEZES AT KJFK/KLGA/KISP/KBDR/KGON. WINDS WILL SHIFT TO THE NW THIS EVENING WITH COLD FRONT PASSAGE WITH GUSTS AROUND 20 KT CONTINUING. WINDS WILL SHIFT TO THE NW THIS EVENING WITH GUSTS AROUND 20 KT. GUSTS END BY 06Z...WITH WINDS VEERING TO THE NE. NE WINDS CONTINUE SUNDAY MORNING. .OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY... .SUN...VFR. WINDS BECOMING SE IN THE AFTERNOON WITH G15-20KT POSSIBLE. .SUN NIGHT...MVFR/IFR IN RAIN. LLWS DEVELOPING LATE. ESE G20-25KT LATE. .MON...MVFR/IFR. RAIN. LLWS EARLY. INCREASING ESE SFC WIND. G30KT. .TUE...MVFR BECOMING VFR. WEST G25KT. .WED-THU...MVFR POSSIBLE IN CHANCE OF SHOWERS.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
GUSTS TO AROUND 20 KT THIS EVENING...WITH POSSIBLY SOME ISOLATED GUSTS TO 25 KT...THEN WINDS DIMINISH TO AROUND 15 KT OR LESS ON ALL WATERS OVERNIGHT...AND REMAIN SO THROUGH SUNDAY EVENING. WINDS INCREASE LATE SUNDAY NIGHT OUT OF THE E. AT THIS TIME...NOT CONFIDENT ENOUGH IN GUSTS TO 25 KT TO PUT IN THE FORECAST...BUT CANNOT RULE OUT. HOWEVER...WINDS SHOULD BE STRONG ENOUGH TO BRING SEAS ON THE COASTAL OCEAN WATERS TO SCA LEVELS LATE SUNDAY NIGHT. HAVE HOISTED AN SCA THERE STARTING AT MIDNIGHT SUNDAY NIGHT AS A RESULT. BY MONDAY...EXPECT CONDITIONS TO DETERIORATE QUICKLY AHEAD OF A FRONTAL SYSTEM...AND HAVE SCA FOR COASTAL OCEAN WATERS ON MONDAY AS RESULT. EXPECT E/SE WINDS TO INCREASE RAPIDLY MONDAY MORNING...WITH BUILDING SEAS THE RESULT. IN FACT...A FEW GALE GUSTS ARE POSSIBLE MONDAY. THE WINDS DIMINISH LATE IN THE DAY AND AT NIGHT AS THE FRONT NEARS. A COLD FRONT WILL PASS ACROSS THE WATERS TUESDAY...AND WINDS ARE EXPECTED TO SHIFT TO THE WEST BEHIND THE FRONT. ELEVATED OCEAN SEAS WILL TAKE SOME TIME TO SUBSIDE THROUGH TUESDAY. HIGH PRESSURE BUILDS WELL TO THE SOUTH TUESDAY AND WEDNESDAY. ANOTHER FRONT APPROACHES WED NIGHT INTO THURSDAY. WINDS INCREASE AHEAD OF AND BEHIND THE FRONT. FOR THE NON OCEAN WATERS...SCA CONDITIONS ARE EXPECTED MONDAY...THEN SUB SCA IS FORECAST THROUGH THURSDAY.
-- End Changed Discussion --
&& .FIRE WEATHER...
-- Changed Discussion --
DRY WEATHER...MINIMUM RH 20-30 PERCENT...AND WINDS GUSTING TO 25-30 MPH WILL LEAD TO ELEVATED POTENTIAL FOR FIRE GROWTH/SPREAD THROUGH EARLY THIS EVENING. GUSTS MAY BRIEFLY STRENGTHEN AFTER THE COLD FRONTAL PASSAGE AS WELL. A RED FLAG WARNING IS IN EFFECT FOR THE WHOLE CWA THROUGH 8 PM GIVEN EXPECTED WEATHER CONDITIONS.
-- End Changed Discussion --
&& .HYDROLOGY...
-- Changed Discussion --
THERE IS THE POTENTIAL FOR SIGNIFICANT RAINFALL WITH AN APPROACHING FRONTAL SYSTEM FROM LATE SUNDAY NIGHT INTO MONDAY NIGHT. STORM TOTAL RAINFALL WITH THIS SYSTEM IS EXPECTED TO BE IN THE 1 TO 2 INCH RANGE. LOCALIZED HIGHER AMOUNTS WILL BE POSSIBLE. THIS COULD CAUSE POSSIBLE MINOR FLOODING OF URBAN AND POOR DRAINAGE AREAS. 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.
-- End Changed Discussion --
&& .TIDES/COASTAL FLOODING...
-- Changed Discussion --
INCREASING E/SE FLOW MONDAY MAY RESULT IN LOCAL TO WIDESPREAD MINOR COASTAL FLOODING. ASTRONOMICAL HIGH TIDES WILL BE RUNNING HIGH FOLLOWING A NEW MOON. IN SOME CASES...DEPARTURES OF ONLY HALF A FOOT ABOVE NORMAL ARE NEEDED. STORM SURGE COULD PRODUCE WATERS LEVELS 1 TO 1 1/2 FT ABOVE NORMAL.
-- End Changed Discussion --
&& .OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR CTZ005>012. NY...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR NYZ067>075- 078>081-176>179. NJ...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR NJZ002-004- 006-103>108. MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT SUNDAY NIGHT TO 6 PM EDT MONDAY FOR ANZ350-353-355.
-- End Changed Discussion --
&& $$ SYNOPSIS...MALOIT/PW NEAR TERM...MALOIT SHORT TERM...MALOIT LONG TERM...PW AVIATION...DS MARINE...MALOIT/PW FIRE WEATHER...MALOIT HYDROLOGY...MALOIT/PW TIDES/COASTAL FLOODING...PW

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.