FXUS61 KOKX 201140
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE UPTON NY
740 AM EDT SAT SEP 20 2008
.SYNOPSIS...
LARGE HIGH PRESSURE RIDGE WILL FINALLY GIVE WAY TO A WEAK COLD FRONT 
LATE SUNDAY. THIS FRONT WILL SLOWLY MOVE THROUGH SUNDAY NIGHT AND 
MONDAY...THEN ANOTHER AREA OF HIGH PRESSURE WILL SETTLE OVER THE 
AREA THROUGH MID WEEK. A DEVELOPING COASTAL LOW MAY APPROACH THE 
AREA LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH CLOUDS SHOULD MOVE ACROSS THE AREA EARLY TODAY AS SEEN ON IR 
IMAGERY. THIS HIGH LEVEL MOISTURE NOT HANDLED TOO WELL BY MODELS.
SHOULD NOT BE THICK ENOUGH TO HAVE A BIG INFLUENCE ON TEMPERATURES. 
IN ADDITION...SCATTERED LOW CLOUDS TO DEAL WITH EARLY THIS MORNING. 
THESE CLOUDS WILL BE TRAPPED UNDERNEATH INVERSION INITIALLY...THEN 
SKIES CLEAR (SCT TO FEW CU) AS INVERSION MIXES OUT WITH DAYTIME 
HEATING. A GOOD DEAL OF SUNSHINE EXPECTED THIS AFTERNOON...AND 
TEMPERATURES WILL WARM A FEW DEGREES HIGHER THAN WHAT WAS OBSERVED 
YESTERDAY DUE TO WEAKER EASTERLY LOW LEVEL FLOW...AND THUS DEEPER 
MIXED LAYER. MOS/LAV NUMBERS LOOK GOOD.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
AS THE RIDGE SETTLES OVER THE AREA AND WEAK FRONT APPROACHES FROM 
THE NORTHWEST...LOW LEVEL EASTERLY FLOW WILL END. AS SUCH...SKIES 
WILL REMAIN CLEAR TONIGHT.
UPPER TROUGH THAT REMAINS WELL TO THE NORTH WILL SLOWLY PROGRESS 
EAST ACROSS SOUTHEAST CANADA. AT THE SURFACE...WEAK FRONT BETWEEN 
RIDGE TO THE SOUTH AND NEXT AREA OF HIGH PRESSURE UP IN CENTRAL 
CANADA WILL APPROACH THE REGION. THIS WILL OCCUR LATER SUNDAY AND 
SUNDAY NIGHT. AN INCREASE IN LOW LEVEL MOISTURE POOLING AHEAD OF 
FRONT...AND WEAK FORCING COULD TRIGGER AN ISOLATED SHOWER OR 
SPRINKLE. BEST TIME FOR ANY PRECIP LOOKS TO BE SUNDAY NIGHT INTO 
EARLY MONDAY. THEN RIDGE PREDOMINATES LATER MONDAY...AND ATMOSPHERE 
DRIES OUT QUICKLY.
TEMPS...SEASONABLE NIGHT TONIGHT...THEN WARMER AIR SWEEPS IN AHEAD 
OF SFC FRONT SUNDAY. 950 HPA TEMPS WARM FROM 12-13C SATURDAY 
(EASTERLY LOW LEVEL FLOW) TO 18-19C SUNDAY.
EXPECTED CLOUD COVER SUNDAY NIGHT WILL KEEP READINGS A TAD HIGHER 
THAN PREVIOUS NIGHTS...BUT MONDAY SHOULD BE QUITE COOL AS CLOUDS 
LINGER AND NORTHEAST FLOW SETS UP ONCE AGAIN.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
BUILDING HIGH PRESSURE WILL RESULT IN ANOTHER STRETCH OF DRY WEATHER 
THROUGH AT LEAST THU. PERSISTENT NE-E CAN BE EXPECTED THROUGH THE 
PERIOD AS THE HIGH REMAINS ANCHORED NORTH OF THE AREA. 
THERE CONTINUES TO MODEL UNCERTAINTY ABOUT HOW CLOSE A LOW OFF THE 
SE COAST WILL APPROACH IN THE THURSDAY NIGHT THROUGH SATURDAY TIME 
FRAME. LATEST GUIDANCE SUGGESTS THAT RIDGING WILL REMAIN FIRMLY IN 
PLACE DURING THE PERIOD...RESULTING IN A MORE EASTERLY TRACK OF THE 
SURFACE LOW. GIVEN UNCERTAINTY REGARDING THIS SURFACE LOW...HAVE 
KEPT POPS LOW FOR THURSDAY NIGHT THROUGH FRIDAY NIGHT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
A FEW POCKETS OF LOW STRATUS REMAIN OVER THE REGION AND ADJACENT
WATERS AS MOISTURE POOLS JUST BELOW THE BASE OF AN INVERSION. 
BASES GENERALLY BETWEEN 3000 AND 3500 FEET...SO WILL CONTINUE TO
CARRY A TEMPO GROUP THROUGH 14Z FOR BKN035. 
WITH WARMER TEMPERATURES EXPECTED TODAY...EXPECT SCT INSTABILITY
CU DEVELOPMENT DURING THE LATE MORNING AND EARLY TO MID AFTERNOON.
IF ANY LCL CIGS DEVELOP...THEY WILL ALSO BE LOW END VFR. THESE
CLOUDS DISSIPATE BY 20-22Z...WITH SKIES TRENDING TO SKC THEREAFTER.
WINDS WILL BE TRICKY AS THE REGION WILL BE IN A TUG OF WAR BETWEEN
A RIDGE OF HIGH PRESSURE THAT RUNS ALONG AND JUST INSIDE OF THE
I-95 CORRIDOR...AND OFFSHORE LOW OVER THE ATLANTIC. WILL KEEP A
GENERAL NE-E FLOW ACROSS THE AREA....AS I EXPECT THE RIDGE AXIS TO
REMAIN TO OUR NORTH...WITH JUST ENOUGH INFLUENCE FROM THE OFFSHORE
LOW TO KEEP THE FLOW FROM TURNING MORE ONSHORE. ONE GOOD THING IS
THAT SPEEDS ARE EXPECTED TO REMAIN 10 KT OR LESS. WILL TAKE WINDS
OVER TO SEA BREEZE DIRECTIONS AT IMMEDIATE COASTAL TERMINALS THIS
AFTERNOON. HOWEVER...CONFIDENCE IS NOT HIGH ENOUGH AT OTHER
TERMINALS TO INCLUDE. FOR 12Z TAF PACKAGE...ONLY JFK...BDR AND GON
WILL INCLUDE THIS WIND SHIFT.
THEREAFTER...PRESSURE PATTERN...AND AS A RESULT WINDS...BECOME
LIGHT AND ERRATIC THIS EVENING...BEFORE A BIT BETTER DEFINED
NORTHWEST FLOW DEVELOPS AROUND OR AFTER MIDNIGHT. EXPECT A LIGHTER
ONSHORE FLOW AT SEA BREEZE TERMINALS WITH VRB AROUND 5 KT
ELSEWHERE FROM 23-00Z THROUGH 03-05Z.
OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY...HI PRES OVER THE REGION
THROUGH WED WITH MAINLY VFR CONDITIONS. A WEAK CDFNT SUN NIGHT/MON
TIME FRAME. ATTM FRONT LOOKS DRY WITH A CHANCE FOR MVFR CIGS AT
TIMES WITH NELY FLOW BEHIND THE FRONT.
&&
.MARINE...
THE AREA REMAINS SANDWICHED BETWEEN INLAND RIDGE OF HIGH PRESSURE 
AND AN OFFSHORE LOW EAST OF THE CAROLINAS. THIS WILL KEEP A FAIRLY 
PERSISTENT NE-E FLOW IN PLACE. WINDS WILL CONTINUE TO GRADUALLY 
DIMINISH TODAY...BUT SEAS SHOULD REMAIN ABOVE SCA THRESHOLDS INTO
SUN. HAVE UNDERCUT WAVEWATCH III...BUT WILL KEEP 4 TO 6 FT ON OCEAN 
WATERS TODAY AND 3 TO 5 FT TONIGHT INTO SUNDAY.
THE PERSISTENT EASTERLY COMPONENT TO THE WINDS...A WEAK EASTERLY 
SWELL AND LARGE BREAKING WAVES WILL RESULT IN A MODERATE RISK OF RIP 
CURRENTS ALONG NEW YORK ATLANTIC BEACHES TODAY.
AN EXTENDED PERIOD OF SCA CONDITIONS IS LIKELY TO RETURN TO THE 
OCEAN WATERS AFTER COLD FROPA ON MON...AS THE AREA ONCE AGAIN 
BECOMES SANDWICHED BETWEEN ANOTHER STRONG INLAND HIGH...AND A 
COASTAL LOW DEVELOPING ALONG THE SOUTHEAST COAST...WITH A PERSISTENT 
NE-E FLOW OVER THE WATERS KEEPING MAX OCEAN SEAS 5+ FEET.
&&
.HYDROLOGY...
NO SIGNIFICANT RAINFALL EXPECTED.
&&
.TIDES/COASTAL FLOODING...
CURRENTLY WATER LEVELS ARE BETWEEN 0 AND 0.75 FT ABOVE NORMAL. THE
TIDE CYCLE OF CONCERN WILL ONCE AGAIN BE THE MIDDAY HIGH TIDE CYCLE...
WHICH IS THE HIGHER OF THE TWO DAILY HIGH TIDES. ASTRONOMICAL TIDES
REMAIN HIGH...AND A DEPARTURE OF ONLY ABOUT 1.0 FT IS NEEDED TO
REACH MINOR COASTAL FLOODING BENCHMARKS. FEEL THAT WE WILL FALL
SHORT OF THIS TODAY DUE TO THE COMBINATION OF A MORE NORTHEAST
FLOW THIS MORNING AND A DECREASING WIND SPEED AS THE DAY PROGRESSES.
THE DEPARTURES FOR THE HIGH TIDE CYCLE OVERNIGHT WERE LESS THAN
YESTERDAY...AND EXPECT THE DECREASING DEPARTURE THEME TO CONTINUE.
MOST LOCALES WILL REMAIN SAFELY BELOW (0.5 FT OR MORE) MINOR 
BENCHMARKS. HOWEVER...WE COULD COME CLOSE IN THE NASSAU SOUTH SHORE 
BACK BAYS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM EDT SUNDAY 
     FOR ANZ350-353-355.
&&
$$