Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 231619 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 1219 PM EDT SAT MAY 23 2015 .SYNOPSIS... HIGH PRESSURE SETTLES ACROSS THE AREA TODAY AND WILL START TO MOVE OFFSHORE TONIGHT. THIS WILL BECOME WELL ESTABLISHED OFFSHORE AS A BERMUDA HIGH CLOSING OUT THE WEEKEND INTO THE NEW WEEK. THERE WILL BE AN APPROACHING WARM FRONT MONDAY THAT WILL MOVE NORTH OF THE REGION MONDAY NIGHT WITH THE AFOREMENTIONED BERMUDA HIGH PERSISTING THEREAFTER. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LITTLE CHANGE FROM THE PREVIOUS UPDATE. JUST SLIGHT ADJUSTMENTS TO HOURLY TEMPS AND DEWPOINTS. HIGH PRESSURE CENTERED JUST TO OUR SOUTH WILL MOVE OFFSHORE. NW FLOW GIVES WAY TO SEA BREEZE DEVELOPMENT LATER THIS AFTERNOON. SUNNY WITH HIGHS IN THE 60S. MIXING WILL ALLOW FOR DEWPOINTS TO LOWER INTO THE UPPER TEENS TO LOWER 20S. AN SPS HAS BEEN ISSUED REGARDING THIS. SEE FIRE WEATHER SECTION FOR MORE DETAILS. THERE IS A MODERATE RISK FOR RIP CURRENTS ALONG THE ATLANTIC BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... TONIGHT MARKS THE COMMENCEMENT OF THE TRANSITION OF AIRMASS TO A WARMER MORE HUMID ONE AS HIGH PRESSURE SETTLES OFFSHORE WITH WARM AIR ADVECTION OCCURRING WITH SW FLOW INCREASING THROUGH THE ATMOSPHERIC COLUMN. THIS IS DIAGNOSED FROM 850MB TEMPS INCREASING A FEW DEGREES THROUGH THE NIGHT. LOWS WILL CONVEY A VAST RANGE...UPPER 30S FOR RURAL COUNTRYSIDE TO UPPER 50S FOR NYC. FOR SUNDAY...WARM AND MOIST AIR ADVECTION WILL RESULT IN A WARMER DAY WITH HIGHER DEWPOINTS WITH SOUTHWEST FLOW INCREASING. THE PRESSURE GRADIENT WILL BECOME TIGHTER AS HIGH PRESSURE SHIFTS FARTHER OFFSHORE. THE DRY WEATHER WILL CONTINUE. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... FOR SUNDAY NIGHT AND INTO THE NEW WEEK...THE JET STREAM WILL BE PUSHING NORTH OF THE REGION WITH HIGH PRESSURE PERSISTING OFFSHORE. THIS WILL ESSENTIALLY BECOME A BERMUDA HIGH. THE WARM AND MOIST AIR ADVECTION WILL CONTINUE. MAX TEMPS AND DEWPOINTS WILL BE ON A STEADY RISING TREND GOING THROUGH THE WEEK. A WARM FRONT MOVING ACROSS MONDAY INTO MONDAY NIGHT WILL ALLOW FOR MORE WARM AND MOIST AIR ADVECTION BEHIND IT. THERE WILL BE A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS NORTH AND WEST OF NYC MONDAY AFTERNOON WITH DAYTIME INSTABILITY AND FRONTAL BOUNDARY IN VICINITY. MORE OF A DIURNAL CONVECTIVE SCENARIO PROCEEDS FOR THE REMAINDER OF THE FORECAST PERIOD AS RIDGE AMPLITUDE MOVES EAST OF THE REGION AND CAPPING ALOFT IS NOT AS PROMINENT. THE SHOWERS AND THUNDERSTORMS WILL BE PRIMARILY CONFINED TO WESTERN INTERIOR PORTIONS OF THE REGION WHERE GREATER INSTABILITY WILL RESIDE. FARTHER EAST...LESS INSTABILITY WILL KEEP CHANCES FOR SHOWERS AND THUNDERSTORMS LOWER. WITH PERSISTENT SOUTHERLY FLOW...EXPECTING PATCHY FOG FOR LATE NIGHT INTO EARLY MORNING HOURS MID TO LATE WEEK AS THE AIRMASS BECOMES INCREASINGLY WARM AND HUMID. && .AVIATION /16Z SATURDAY THROUGH WEDNESDAY/... HIGH PRESSURE WILL BUILD TO THE SOUTH OF THE AREA THROUGH TONIGHT. VFR THROUGH THE TAF PERIOD. NW FLOW WILL BACK TO THE W...THEN SW THIS AFTERNOON. SPEEDS WILL BE GENERALLY AROUND 10 KT...EXCEPT AT KISP WHERE CLOSE TO 15 KT...BUT SPEEDS SHOULD REDUCE TO AROUND 10 KT THIS AFTERNOON. GUSTS TO THE UPPER TEENS ARE POSSIBLE THIS AFTERNOON. HAVE PUT IN TAFS AT TERMINALS WHERE MOST LIKELY. KJFK COULD SEE FLOW BACK TO SSW BY LATE AFTERNOON DUE TO SEA BREEZE INFLUENCE...AND SEE SPEED INCREASE TO CLOSER TO 15 THAN 10 KT. WINDS DIMINISH THIS EVENING...GENERALLY FROM THE S/SW. .OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY... .SUNDAY-MONDAY...VFR. SW WINDS G15-20KT POSSIBLE IN THE AFTERNOON. .MONDAY NIGHT-WEDNESDAY...MVFR OR LOWER POSSIBLE IN FOG/STRATUS LATE AT NIGHT/MORNING. S-SW WINDS G15-20KT POSSIBLE IN THE AFTERNOON. && .MARINE... FORECAST MAINLY ON TRACK. SEA BREEZES EXPECTED TO DEVELOP BY LATE AFTN...WHICH COULD INCREASE WINDS...BUT SHORT OF SCA CRITERIA. THE WINDS SHIFT TO THE WEST...THEN SW AS HIGH PRESSURE PASSES TO THE EAST. THIS HIGH DRIFTS EAST TONIGHT AND SUNDAY. IN FACT...THIS HIGH WILL REMAIN NEARLY STATIONARY OVER THE WESTERN ATLANTIC FOR SEVERAL DAYS. AS SUCH...A PERSISTENT SW/S FLOW WILL PREVAIL ACROSS THE WATERS THROUGH AT LEAST THE MID WEEK PERIOD. IN GENERAL...WINDS SHOULD REMAIN BELOW SCA CRITERIA SUNDAY THROUGH WEDNESDAY WITH WARMER AIR MOVING OVER THE COOLER WATERS. SOME NEAR SHORE GUSTS EACH AFTERNOON MAY APPROACH SCA LEVELS...ESPECIALLY AROUND STRONGER AFTERNOON SEA BREEZES THAT MAY DEVELOP. HOWEVER...WITH A PERSISTENT SOUTHWESTERLY FLOW...SEAS ON THE OCEAN WATERS ARE EXPECTED TO EVENTUALLY BUILD TO SMALL CRAFT LEVELS. THIS WOULD MOST LIKELY OCCUR MONDAY NIGHT WITH SEAS THEN REMAINING AT SMALL CRAFT LEVELS INTO WEDNESDAY. && .FIRE WEATHER... WITH DAYTIME MIXING AND NORTHWEST FLOW...DEWPOINTS WILL LOWER INTO THE 20S AND UPPER TEENS AS TEMPERATURES RISE INTO THE 60S. THE RESULTING RELATIVE HUMIDITY VALUES WILL DROP TO 15 TO 30 PERCENT THIS AFTERNOON INTO THE EARLY EVENING. THE WIND SPEEDS WILL BE GENERALLY 10 TO 15 MPH ON AVERAGE WITH GUSTS UP TO 20 MPH AND OCCASIONALLY UP TO 25 MPH. THIS WILL ENHANCE THE SPREAD AND GROWTH OF ANY FIRES THAT DEVELOP. && .HYDROLOGY... NO SIGNIFICANT WIDESPREAD RAIN EXPECTED THROUGH THE FORECAST PERIOD. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...JM NEAR TERM...JC/JM SHORT TERM...JM LONG TERM...JM AVIATION...MALOIT/PW MARINE...JC/PW FIRE WEATHER... HYDROLOGY...JM

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