Area Forecast Discussion
Issued by NWS Upton, NY

Current Version | Previous Version | Text Only | 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 200850 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 450 AM EDT MON APR 20 2015 .SYNOPSIS... A WARM FRONT APPROACHES FROM THE SOUTH TODAY. AN ASSOCIATED WAVE OF LOW PRESSURE AND COLD FRONT THEN MOVE THROUGH THE REGION LATE TONIGHT. WEAK HIGH PRESSURE FOLLOWS FOR TUESDAY. A SERIES OF WEAK COLD FRONTS AND/OR TROUGHS WILL MOVE ACROSS THE REGION FOR THE MIDDLE TO THE LATE WEEK PERIOD. SURFACE HIGH PRESSURE BUILDS INTO THE REGION FROM THE NORTH FOR NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MODERATE TO POTENTIALLY BRIEFLY HEAVY RAINFALL SHIFTS THROUGH THE CWA THIS MORNING INTO EARLY AFTERNOON WITH THE HELP OF STRONG ISENTROPIC LIFT AHEAD OF AN APPROACHING WARM FRONT AND A LLJ. STILL A DECENT SHOT AT ADDITIONAL RAINFALL LATER THIS AFTERNOON...BUT WITH LESS LIFT AND MID LEVELS DRYING...INTENSITY WILL BE ON THE LIGHTER SIDE. LOOKS LIKE WE FALL SHORT OF FLASH FLOOD GUIDANCE...SO EXPECTING ONLY SOME MINOR URBAN/POOR DRAINAGE/SMALL STREAM FLOODING AT MOST. BETTER OVERALL CHANCES FOR THIS WOULD BE BEFORE LATE AFTERNOON. BREEZY CONDITIONS...ESPECIALLY FOR THE COASTAL AREAS THIS MORNING. WINDS SUBSIDE THIS AFTERNOON...BUT STILL ON THE BREEZY SIDE. GUSTS FROM THE LLJ ALOFT WILL HAVE A TOUGH TIME MIXING DOWN. ANY WIND ADVISORY-CRITERIA GUSTS THAT MANAGE TO MIX DOWN WITH HEAVIER DOWNPOURS WOULD BE TOO ISOLATED AND TOO LOW OF CHANCE FOR ANY ADVISORY CONSIDERATION. SUSTAINED WINDS COULD COME CLOSE TO CRITERIA FOR COASTAL SECTIONS THIS MORNING...BUT LOOKS LIKE WE`LL FALL SHORT. NAM/MAV MOS BLEND WAS USED FOR HIGH TEMPS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... WAVE OF LOW PRESSURE/TRIPLE POINT IS PROGGED TO MOVE THROUGH THE NW ZONES OR JUST NORTH OF US TONIGHT...DRAGGING A COLD FRONT THROUGH. ASSOCIATED UPWARD FORCING AND MOISTURE BRINGS PERIODS OF RAIN. THE WARM FRONT ASSOCIATED WITH THIS SYSTEM MAKES IT THROUGH AT LEAST PART OF THE CWA...MORE LIKELY THE EASTERN SECTIONS. IN ANY CASE...ELEVATED INSTABILITY SPREADS ACROSS THE ENTIRE AREA...AND WITH A MID LEVEL SHORTWAVE MOVING THROUGH PLUS MAYBE SOME ENHANCED LIFT FROM A JET STREAK...AN ISOLATED THUNDERSTORM IS POSSIBLE. WITH THE WARM FRONT MOVING THROUGH PART OF THE AREA...PLUS WINDS BECOMING LIGHTER AS THE CENTER OF THE LOW PRESSURE WAVE MOVES THROUGH...FOG IS EXPECTED. AND WITH HIGH DEWPOINT AIR MOVING OVER SEA SURFACE TEMPS IN THE MID 40S...THE COMBINATION OF ALL OF THIS BRINGS SOME CONCERN FOR AREAS OF DENSE FOG. WILL ALLOW DAY SHIFT TO LOOK AT GUIDANCE AND REASSESS THE NEED FOR ANY ADVISORIES CONCERNING THIS. FOR TUESDAY...ONLY LOW CHANCES OF A LINGERING SHOWER EARLY IN THE MORNING OVER THE FAR EASTERN ZONES. A MID LEVEL SHORTWAVE IS FORECAST TO MOVE THROUGH IN THE MORNING WITH STRONGER LIFT GENERALLY OVER THE NORTHERN ZONES...BUT IT APPEARS THAT MOISTURE WILL BE GREATLY REDUCED BY THE TIME IT SHIFTS THROUGH...SO NO RAINFALL EXPECTED WITH THIS FEATURE. TURNING PARTLY TO MOSTLY SUNNY. A WESTERLY FLOW ALLOWS FOR MIXING TO AT LEAST 850 MB. WITH AFTN TEMPS 4-5C AT THIS LEVEL...SIDED WITH THE WARMER NAM MOS FOR HIGHS. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... A PERIOD OF UNSETTLED WEATHER IS ON TAP FOR MUCH OF THE UPCOMING WEEK AS A SERIES OF WEAK COLD FRONTS AND UPPER TROUGHS MOVE ACROSS THE REGION. DEEP UPPER LOW NORTH OF THE GREAT LAKES WILL SLOWLY TRACK INTO EASTERN CANADA THROUGH FRIDAY. A SERIES OF STRONG SHORTWAVES WILL PASS ACROSS THE REGION DURING THIS TIME...AND WILL KEEP CHANCE POPS IN THE FORECAST INTO THURSDAY. IT SHOULD NOT RAIN ALL THE TIME...BUT THERE WILL BE AT LEAST SOME SHOWERS DURING THIS TIME. SFC HIGH PRES BUILDS INTO THE GREAT LAKES/OHIO VALLEY BY THE END OF THE WEEK AS THE UPPER LOW MOVES OFFSHORE. CONDS BEGIN TO DRY OUT...BUT A FEW LINGERING SHORTWAVES MAY TOUCH OFF A SHOWER OR TWO THURSDAY/FRIDAY. LOW CONFIDENCE FORECAST FOR NEXT WEEKEND...AS MODELS DIVERGE AS TO TIMING AND PLACEMENT OF LOW PRES APPROACHING FROM THE WEST. GFS TAKES LOW PRES THROUGH THE MID-ATLANTIC AND IT PASSES SOUTH OF THE 70/40 BENCHMARK DURING THE DAY SATURDAY. PRECIP OVERSPREADS THE REGION DURING THIS TIME. MEANWHILE...THE ECMWF HAS THE LOW MUCH WEAKER AND SLOWER...AND HIGH PRES BUILDING INTO THE GREAT LAKES/OHIO VALLEY WILL KEEP THE LOW OVER THE GULF COAST STATES. WPC IS FOLLOWING THIS TRACK...AND WILL FOLLOW SUIT AND GO WITH A MAINLY DRY FORECAST FOR NEXT WEEKEND. SW FLOW WILL USHER A MILD AIRMASS INTO THE REGION FOR WEDNESDAY... ALLOWING FOR SLIGHTLY ABOVE NORMAL TEMPS OVER THE AREA. TEMPS FOR THE REST OF THE WEEK AND INTO THE WEEKEND WILL THEN BE SLIGHTLY BELOW NORMAL. && .AVIATION /09Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
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
-- End Changed Discussion --
&& .MARINE... WINDS INCREASE EARLY THIS MORNING. WITH LOW LEVEL INVERSION AND COLDER OCEAN TEMPERATURES...CONFIDENCE IN SEEING WIDESPREAD GALES IS LOW. HAVE CONTINUED TO MENTION OCCASIONAL GUSTS TO 35 KT. IF THESE GUSTS OCCUR...IT WILL BE OVER A SHORT TIME PERIOD AS A LOW LEVEL JET MOVES OVERHEAD THIS MORNING INTO EARLY AFTERNOON. WILL CONTINUE WITH SMALL CRAFT ADVISORIES ON ALL WATERS TODAY. MIGHT BE ABLE TO END THE SCA OVER THE HARBOR AND WESTERN SOUND EARLIER THAN CURRENTLY POSTED. OCEAN SEAS WILL BUILD 7 TO 12 FEET. WINDS SUBSIDE FROM WEST TO EAST LATE THIS AFTERNOON AND EVENING. OCEAN SEAS WILL CONTINUE TO REMAIN HIGH THROUGH TONIGHT AND TUESDAY AS WELL. HAVE THEREFORE EXTENDED SCA ON THE OCEAN THRU TUES AFTN. COLD FRONT MOVES ACROSS THE WATERS ON WEDNESDAY. 25 KT WIND GUSTS POSSIBLE FOR THE WESTERN WATERS FOR A BRIEF PERIOD...BUT SEAS WILL REMAIN ABOVE SCA LEVELS INTO THURSDAY. TRANQUIL CONDS WILL RETURN FOR THE END OF THE WEEK AND INTO THE WEEKEND AS HIGH PRES BUILDS IN FROM THE WEST. && .HYDROLOGY... STORM TOTAL RAINFALL WITH THIS SYSTEM WILL RANGE MOSTLY FROM 1 TO 1.5 INCHES WITH LOCALLY HIGHER AMOUNTS. THIS COULD CAUSE MINOR FLOODING OF URBAN/POOR DRAINAGE/SMALL STREAMS...PRIMARILY THIS MORNING INTO EARLY AFTERNOON. 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. && .TIDES/COASTAL FLOODING... WITH STRENGTHENING E/SE FLOW AND HIGH ASTRONOMICAL TIDES...WILL NEED TO WATCH DEPARTURES OVER TODAY`S AND TONIGHT`S HIGH TIDE CYCLES. THIS MORNING`S ASTRONOMICAL HIGH TIDES WILL BE LOWER THAN LAST NIGHT`S...OFFSETTING THE STRENGTHENING ONSHORE FLOW. LOOKS LIKE THE DURATION OF STRONG WINDS BEFORE THE HIGH TIDE CYCLE ACROSS THE SOUTH SHORE BAYS WILL BE JUST SHORT ENOUGH TO PRECLUDE A COASTAL FLOOD STATEMENT. OTHERWISE...WILL KEEP THE STATEMENT GOING FOR ISOLATED MINOR FLOODING ACROSS THE WESTERN SOUND FOR THE MORNING HIGH TIDE CYCLE. NOT ENOUGH CONFIDENCE THAT ENOUGH TIDAL PILING OCCURS FOR A CHANCE OF MINOR COASTAL FLOODING WITH TONIGT`S CYCLE IN SPITE OF HIGHER ASTRONOMICAL TIDES. WILL ALLOW DAY SHIFT TO MONITOR THE TRENDS AND CHANGE HEADLINES AS NECESSARY. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ338- 345. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330- 335-340. SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355. && $$ SYNOPSIS...JC/MPS NEAR TERM...JC SHORT TERM...JC LONG TERM...MPS AVIATION...GC MARINE...JC/MPS HYDROLOGY...JC/MPS TIDES/COASTAL FLOODING...

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