Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 181436 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 1036 AM EDT FRI APR 18 2014 .SYNOPSIS... HIGH PRESSURE RETREATS TO THE NORTHEAST TODAY...WITH ANOTHER AREA OF HIGH PRESSURE BUILDING DOWN FROM SOUTHERN CANADA THROUGH THE WEEKEND. THE HIGH THEN SLOWLY SLIDES TO THE EAST INTO TUESDAY. A FRONTAL SYSTEM WILL IMPACT THE AREA FROM TUESDAY INTO WEDNESDAY. HIGH PRESSURE THEN BUILDS DOWN FROM SOUTH CENTRAL CANADA INTO THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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UPDATED TEMPERTURES...DEWPOINTS...AND CLOUD COVERAGE. INCREASED CLOUDS AS MOISTURE WILL BECOME TRAPPED UNDERNEATH A SUBSIDENCE INVERSION. THIS WAS EVIDENT IN THE OKX 12Z SOUNDING NEAR 925MB. MAX TEMPS WERE DECREASED A FEW DEGREES AS WELL...MORE SO FOR COASTAL SECTIONS WITH MORE MARITIME INFLUENCE. UNCERTAINTY ON HOW LONG IT WILL TAKE FOR CLOUDS WILL SCATTER OUT WHEN THE INVERSION BREAKS. LIKEWISE...MAX TEMPS COULD BE A FEW DEGREES TOO LOW IF THIS OCCURS. GENERALLY DRY WEATHER TODAY WITH HIGH PRESSURE SLOWLY PUSHING TO THE NORTHEAST AS A WEAKENING FRONT APPROACHES FROM THE NORTH AND WEST. GENERAL MODEL CONSENSUS HAS TRENDED IN KEEPING THE FRONT TO THE NORTH...WITH NO PRECIP EXPECTED TO IMPACT THE AREA AS THE MAIN NORTHERN STREAM ENERGY REMAINS OVER NORTHERN NEW ENGLAND AS WELL. STRATUS IN NEW JERSEY AND SOUTHERN NYC/LONG ISLAND IS EXPECTED TO PERSIST THROUGH THE MORNING WITH THE NORTHEAST FLOW. AS THE WINDS COME AROUND TO THE SOUTH...SHOULD SEE THE LOW LEVEL CLOUDS BEGIN TO SCATTER OUT BUT A PASSING VORT MAX WILL KEEP THE INCREASED SKY COVERAGE...INCREASING THE MID AND HIGH LEVEL CLOUDS FOR THE REMAINDER OF THE AFTERNOON. DESPITE A WARMING TREND WITH WAA...THE COMBINATION OF THE NORTHEAST FLOW...AND CLOUD COVER WILL HELP TO KEEP TEMPERATURES STILL ALMOST 10 DEGREES BELOW NORMAL.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... SURFACE HIGH RETREATS TO THE NORTHEAST BY TONIGHT...WITH A WEAK TROUGH SETTING UP BRIEFLY OVER NEW ENGLAND. THE TROUGH IS QUICKLY REPLACED BY THE NEXT HIGH PRESSURE...BUILDING SOUTH AND EAST FROM CANADA. UPPER LEVEL TROUGH SWINGS THROUGH TONIGHT BUT AGAIN MAIN FORCING IS TO THE NORTH AND WITH LITTLE TO NO FORCING AT THE SURFACE ALONG WITH MINIMAL MOISTURE...SHOULD SEE A DRY NIGHT. RIDGING SETS UP QUICKLY BEHIND THE DEPARTING TROUGH FOR SATURDAY AND WITH BUILDING SUBSIDENCE...SATURDAY LOOKS TO BE A DRY AND SUNNY DAY ONCE THE MORNING CLOUDS SCATTER OUT. TEMPERATURES EXPECTED TO REBOUND BACK TO NEAR NORMAL FOR TONIGHT...AND THEN EVEN A FEW DEGREES ABOVE NORMAL ON SATURDAY WITH DOWNSLOPING INFLUENCE. INCREASED WINDS AND LOW RH VALUES ON SATURDAY COULD LEAD TO AN ENHANCED RISK OF FIRE SPREAD. NORTHWEST WINDS WILL INCREASE...WITH SUSTAINED 10-15 MPH...AND GUSTS UP TO 20 MPH DURING THE AFTERNOON...CORRESPONDING WITH RH VALUES DROPPING TO AROUND 30 PERCENT. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... A NORTHERN STREAM RIDGE BUILDS OVER THE AREA SATURDAY NIGHT AND SUNDAY...THEN SLIDES TO THE NORTHEAST SUNDAY NIGHT. ASSOCIATED SUBSIDENCE SHOULD KEEP THE AREA DRY AND WITH MINIMAL CLOUD COVER IN THIS TIME FRAME. FOR LOWS SATURDAY NIGHT USED A BLEND OF MAV/MET GUIDANCE...WITH VALUES NEAR NORMAL IN NYC PROPER...AND A FEW DEGREES BELOW NORMAL ELSEWHERE. FOR HIGHS SUNDAY USED A BLEND OF MIXING DOWN FROM 925-875 HPA PER BUFKIT SOUNDINGS...WITH NAM 2-METER TEMPERATURES AND A BLEND OF MAV/MET GUIDANCE. EXPECT READINGS TO BE SLIGHTLY BELOW NORMAL. FOR LOWS SUNDAY NIGHT USED A BLEND OF NAM 2-METER TEMPERATURES WITH A BLEND OF MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE...WITH VALUES A FEW DEGREES BELOW NORMAL. ANOTHER NORTHERN STREAM RIDGE BUILDS OVER THE AREA MONDAY...THEN EXITS TO THE NORTHEAST MONDAY NIGHT. ASSOCIATED SUBSIDENCE WILL KEEP THINGS DRY...BUT COULD SEE AN INCREASE IN MAINLY MID TO HIGH CLOUDS BY LATE MONDAY NIGHT AHEAD OF AN APPROACHING DEVELOPING FULL LATITUDE TROUGH. TROUGH CONTINUES TO SHARPEN AS IT SLOWLY MOVES EAST INTO THE WESTERN APPALACHIANS ON TUESDAY...WITH ANY PRECIPITATION AHEAD OF IT LIKELY CONFINED TO THE NW 1/3-1/2 OF THE CWA. AS THE TROUGH MOVES INTO E PA/UPSTATE NY TUESDAY NIGHT...AND BEGINS TO TAKE ON A BIT OF A NEGATIVE TILT...WOULD EXPECT WIDESPREAD SHOWERS ACROSS THE CWA TUESDAY NIGHT. HOWEVER...NOTING SOME DIFFERENCES IN MODEL TIMING...AND INHERENT UNCERTAINTY THIS FAR OUT...HAVE CAPPED POPS AT CHANCE AT THIS TIME. SOME UNCERTAINTY AS TO HOW QUICKLY THE PRECIPITATION EXITS TO THE E ON WEDNESDAY...THOUGH THE 00Z ECMWF HAS COME CLOSER TO THE 00Z CMC AND GFS WHEN COMPARED TO THE 12Z ECMWF. MAIN QUESTION IS HOW SOON WILL A CUTOFF LOW DEVELOP AS THE TROUGH CONTINUES TO NEGATIVELY TILT AS IT LIFTS NORTHEAST...AND HOW QUICKLY WILL THIS CUTOFF LIFT TO THE NE. FOR NOW...HAVE LEANED TOWARDS THE SLIGHTLY SLOWER ECMWF SOLUTION...AS SLOWER IS OFTEN THE BETTER FORECAST WITH NEGATIVELY TILTED SYSTEMS. AS A RESULT DO HAVE SLIGHT CHANCE POPS OVER MOST OF THE AREA WEDNESDAY MORNING...AND THE NE 1/3 OF THE CWA WEDNESDAY AFTERNOON. A DEEP LAYERED RIDGE BEGINS TO BUILD IN FROM THE MIDWEST WEDNESDAY NIGHT AND THURSDAY...SO HAVE GONE WITH A DRY FORECAST FOR NOW. HOWEVER...WITH A DEVELOPING CUTOFF LOW FORECAST TO BE NOT TO FAR TO THE NE...CANNOT COMPLETELY RULE OUT THAT THE FORECAST COULD LATER EVOLVE INTO A CLOUDIER ONE WITH ISOLD-SCT SHOWERS IN THIS TIME FRAME. FOR TEMPERATURES MONDAY-THURSDAY USED A BLEND OF MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE. TEMPERATURES SHOULD RUN NEAR NORMAL ON MONDAY...ABOVE NORMAL ON TUESDAY...WITH THE POSSIBILITY OF SOME AREAS MAINLY FROM NYC ON W HITTING 70. WEDNESDAY AND THURSDAY FOR NOW SHOULD SEE TEMPERATURES WITHIN A FEW DEGREES ON EITHER SIDE OF NORMAL. HOWEVER...IF THE AFOREMENTIONED CUTOFF LOW ENDS UP CLOSER TO THE AREA...THEN BELOW NORMAL TEMPERATURES WOULD BE POSSIBLE. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... HIGH PRESSURE CENTERED OVER THE CANADIAN MARITIMES AND EXTENDING DOWN THE EASTERN SEABOARD WILL SLOWLY MOVE EAST WHILE WEAKENING TODAY. MVFR STRATUS STRUGGLING TO SCOUR OUT...SO WILL KEEP IN THE TAF TIL 18Z OR SO. EAST FLOW CONTINUES THROUGH THE DAY...BUT LOCAL SEA BREEZES THIS AFTERNOON WILL TURN WINDS S/SE AT 8-12 KT. WINDS DIMINISH TO 5 KT OR LESS TONIGHT. LOW CONFIDENCE AS TO WHETHER OR NOT STRATUS WILL REDEVELOP AFTER 00Z SATURDAY...SO WILL LEAVE OUT OF THE TAFS FOR NOW. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: CIGS BKN020-025 THROUGH 18Z. KLGA FCSTER COMMENTS: CIGS BKN020-025 THROUGH 18Z. KEWR FCSTER COMMENTS: CIGS BKN020-025 THROUGH 18Z. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: OCNL CIGS BKN025 THROUGH 18Z. KHPN FCSTER COMMENTS: POTENTIAL FOR BKN CIGS 2000-2500 FT THROUGH 18Z. KISP FCSTER COMMENTS: CIGS BKN015-020 THROUGH 18Z. .OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY... .SATURDAY-MON NIGHT...VFR. .TUE/TUE NIGHT...MVFR POSSIBLE WITH SHOWERS...COLD FROPA. && .MARINE...
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SCA FOR HAZARDOUS SEAS REMAINS IN EFFECT THROUGH 06Z AS LINGERING EASTERLY SWELL KEEPS HIGHER SEAS WITHIN THE FORECAST COASTAL OCEAN ZONES. POTENTIAL IS THERE FOR THESE HIGHER SEAS TO LAST LONGER THROUGH THE WHOLE NIGHT BUT FORECAST FOR NOW DROPS CONDITIONS TO BELOW SCA TOWARDS DAYBREAK SATURDAY. ELSEWHERE...SUB-SCA CONDITIONS EXPECTED THROUGH SATURDAY. ONCE THE SEAS ON THE OCEAN SUBSIDE TONIGHT...SUB-SCA CONDITIONS EXPECTED THERE AS WELL. AT THIS TIME...SUB-SCA CONDITIONS ARE FORECAST FROM SATURDAY NIGHT-TUESDAY...WITH WINDS ON NON-OCEAN WATERS 10 KT OR LESS. HOWEVER...THERE IS A CHANCE THAT THE COASTAL OCEAN WATERS COULD EXPERIENCE WIND GUSTS TO AROUND 25 KT LATE SATURDAY NIGHT AND SUNDAY. OTHERWISE WINDS ON THE COASTAL OCEAN WATERS SHOULD ALSO BE 10 KT OR LESS UNTIL LATE TUESDAY.
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&& .HYDROLOGY... NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE WEEKEND. THERE IS THE POTENTIAL FOR A SIGNIFICANT RAINFALL FROM LATE TUESDAY INTO WEDNESDAY MORNING. AT THIS TIME...THERE IS TOO MUCH UNCERTAINTY TO SPECIFY EXACT AMOUNTS OR ANY POTENTIAL IMPACTS - IF ANY. NOTE...MINOR FLOODING CONTINUES ALONG THE CONNECTICUT RIVER. FOR ADDITIONAL INFORMATION...PLEASE REFER TO THE LATEST FLOOD WARNINGS FROM NWS TAUNTON MA. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 AM EDT SATURDAY FOR ANZ350-353-355. && $$ SYNOPSIS...MALOIT/SEARS NEAR TERM...JM/SEARS SHORT TERM...SEARS LONG TERM...MALOIT AVIATION...BC/MPS MARINE...JM/MALOIT/SEARS HYDROLOGY...MALOIT/SEARS

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