Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 100807 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 407 AM EDT THU JUL 10 2014 .SYNOPSIS... A COLD FRONT STALLS JUST SOUTH OF THE REGION TODAY THROUGH TONIGHT. HIGH PRESSURE FROM THE GREAT LAKES BUILDS IN FROM THE WEST ON FRIDAY. HIGH PRESSURE WILL THEN REMAIN IN THE VICINITY THROUGH SATURDAY. A SERIES OF LOW PRESSURE TROUGHS THEN DEVELOP NEARBY THROUGH TUESDAY...FOLLOWED BY A COLD FRONT PASSAGE TUESDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE FRONT IS IN THE VICINITY OF WATERS JUST SOUTH OF LONG ISLAND. CONVECTION STILL DEVELOPING ALONG IT ABOUT 20 NM SOUTH OF LONG ISLAND...MAINLY EAST OF MORICHES INLET. ALOFT...THERE WILL BE INCREASING JET STREAM FROM SOUTHWEST TO NORTHEAST DEVELOPING THROUGH THE DAY. A GRADUAL LIFTING TO THE NORTH OF THE MID AND UPPER LEVEL TROUGHS IS EVIDENT WITHIN THE MODEL GUIDANCE. THE FRONT WILL NOT MAKE MUCH SOUTHWARD PROGRESS THE FIRST HALF OF THE DAY SO CHANCES FOR CONVECTION WILL LINGER ESPECIALLY SOUTH OF LONG ISLAND AS WELL AS THE EASTERN END OF LONG ISLAND. THESE ARE RELATIVELY LOW WITH DRIER AIR MOVING IN FROM THE NORTH ADVECTED BY THE NORTHERLY WINDS. THERE ALSO COULD BE A SHOWER OR THUNDERSTORM FROM THE RELATIVELY HIGHER TEMPERATURES AND THEREBY HIGHER INSTABILITY ACROSS THE INTERIOR THIS AFTERNOON BUT CHANCES ARE ONLY SLIGHT. A BLEND OF MAV/MET/GMOS WAS USED FOR HIGHS...YIELDING MOSTLY 80S...HIGHER END ACROSS INTERIOR WHERE THEY WILL HAVE THE AID OF DOWNSLOPE FLOW. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... THE FRONT WILL BE MAKING MORE SOUTHWARD PROGRESS THIS EVENING WITH INSTABILITY LOWERING AS TEMPERATURES COOL. THE HEIGHTS ALOFT CONTINUE TO BUILD...ALLOWING FOR LESS STEEP LAPSE RATES FURTHER LIMITING INSTABILITY. A DRYING TREND CONTINUES WITH HIGH PRESSURE STARTING TO BUILD IN FROM THE WEST. LOWS WERE A BLEND OF GMOS AND MET AND WILL BE A LITTLE COOLER THAN RECENT NIGHT TEMPERATURES. FOR FRIDAY...HIGH PRESSURE CONTINUES TO BUILD IN FROM THE WEST WITH CONTINUED RIDGING ALOFT. OUTSIDE OF A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM ACROSS THE INTERIOR...DRY CONDITIONS ARE EXPECTED. TEMPERATURES ARE FORECAST TO BE RELATIVELY SIMILAR TO THE PREVIOUS DAY...ALBEIT COOLER AT THE COAST WITH MORE OF A ONSHORE COMPONENT TO THE WIND. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE KEEPS THE AREA DRY FRIDAY AND NIGHT AND SATURDAY WITH CLEAR TO PARTLY CLOUDY SKIES. PREFERRED THE WARMER MAV MOS GUIDANCE FOR HIGHS ON SATURDAY BASED ON MIXING PROFILES...WINDS...AND SKY COVER. ON SUNDAY...A SHORTWAVE COULD TRIGGER ISOLATED TO SCATTERED TSTMS...FOCUSED MORE TOWARD THE AFTERNOON AND OVER THE WESTERN HALF OF THE AREA. HIGH TEMPS AROUND OR SLIGHTLY ABOVE SATURDAY`S. LOW PRESSURE OVER THE GREAT LAKES SLOWLY TRACKS NE INTO QUEBEC MONDAY THROUGH TUESDAY NIGHT. AN ASSOCIATED COLD FRONT SLOWLY APPROACHES AT THE SAME TIME...PASSING THROUGH MOST LIKELY DURING TUESDAY NIGHT. A SERIES OF PRE-FRONTAL TROUGHS WILL DEVELOP AHEAD OF THIS FRONT...AND ALONG WITH THE FRONT...WILL BE THE FOCUS OF MOISTURE CONVERGENCE/LIFT AND A TRIGGER FOR THUNDERSTORMS. SYNOPTIC LIFT DOESN`T LOOK TOO SIGNIFICANT AT THIS TIME WITH THE UPPER JET PROGGED TOO FAR TO THE NW...HOWEVER A FEW MID LEVEL SHORTWAVES PROBABLY PASS THROUGH AND SUPPLY SOME LIFT. CAPPED POPS AT 50% THROUGH THE PERIOD...BUT IF MODELS ARE CORRECT WITH THE TIMING OF THE COLD FRONT...WILL PROBABLY NEED TO BUMP UP POPS TUES AFTN/EVENING. SHEAR AND CAPE VALUES ARE ENOUGH TO SUPPORT STRONG TO SEVERE THUNDERSTORMS. HIGH TEMPS BOTH DAYS NEAR NORMAL...BUT ON THE MUGGY SIDE WITH DEWPOINTS 65-70. A DRIER AIR MASS FOLLOWS BEHIND THE COLD FRONT ON WEDNESDAY. THE FLOW ALOFT BECOMES MORE CYCLONIC...BUT AT THIS TIME IT APPEARS THAT MOISTURE IS LACKING FOR DIURNAL SHOWER/TSTM DEVELOPMENT. HIGHS MOSTLY IN THE LOW 80S. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... MOST CONVECTION ASSOCIATED WITH A WEAK COLD FRONT PASSING THRU HAS WEAKENED...SO FOR THE MOST PART EXPECT VFR CONDS OVERNIGHT EXCEPT AT KGON WHERE MVFR VSBY IS POSSIBLE. AS HIGH PRESSURE BUILDS TO THE NORTH AFTER COLD FROPA...EXPECT LIGHT N WINDS TO VEER NE-E THIS MORNING TO AROUND MIDDAY...THEN SHIFT SE-S AT 5-10 KT THIS AFTERNOON VIA COMBO OF THE HIGH BUILDING TOWARD THE REGION AND AFTERNOON SEA BREEZE DEVELOPMENT. .OUTLOOK FOR 06Z FRI THROUGH MON... .THU-SAT...VFR. .SUNDAY-MON...SCATTERED SHOWERS AND TSTMS WITH LOCAL MVFR OR LOWER CONDS AND GUSTY WINDS. && .MARINE... THE DOWNWARD TREND IS BEING OBSERVED WITH WINDS AND SEAS. THE PERSISTENT DECREASE IN PRESSURE GRADIENT WILL KEEP THIS TREND GOING DOWN WITH WINDS AND SEAS. ONE FEATURE TO WATCH WITH THE SEAS IS TO SEE HOW FAST THEY LOWER FOR EASTERN OCEAN ZONES IN RESPONSE TO WINDS BECOMING LIGHT AND EASTERLY. THE SOUTHERLY SWELL MAY ALLOW FOR PERSISTENT SEAS NEAR 5 FT. FOR THE TIME BEING...LEFT END TIME OF SMALL CRAFT FOR EASTERN OCEAN 18Z TODAY. THEREAFTER WITH THE AFOREMENTIONED DECREASE IN PRESSURE GRADIENT...EXPECTING SUB SCA CONDITIONS THROUGH FRIDAY. WINDS AND SEAS CONTINUE TO REMAIN BELOW SCA LEVELS FRIDAY NIGHT THROUGH MONDAY. SCA CONDITIONS RETURN MON NIGHT AND TUE ON THE OCEAN WATERS WITH A MODERATE SW FLOW BUILDING SEAS. && .HYDROLOGY... NO WIDESPREAD SIGNIFICANT HYDROLOGIC ISSUES EXPECTED THROUGH THE WEEKEND. ANY TSTMS MON AND TUE WILL BE CAPABLE OF PRODUCING LOCALLY HVY RAIN. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ350. && $$ SYNOPSIS...JM NEAR TERM...JM SHORT TERM...JM LONG TERM...JC AVIATION...GOODMAN MARINE...JC/JM HYDROLOGY...JC/JM

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