000
FXUS61 KOKX 112041
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
341 PM EST THU MAR 11 2010
.SYNOPSIS...
HIGH PRESSURE REMAINS OVER SOUTHEAST CANADA AS LOW PRESSURE
APPROACHES FROM THE SOUTHWEST. THIS LOW PASSES JUST SOUTH OF THE
AREA THIS WEEKEND...THEN MOVES WELL TO THE EAST NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
EAST FLOW CONTINUES...WITH LOW AND MID CLOUDS OBSERVED ACROSS
MUCH OF THE AREA. COULD SEE SOME LIGHT RAIN OR SPRINKLES OVERNIGHT
IN WEAK ISENTROPIC LIFT. OTHERWISE...ANY LIFT REMAINS LOW LEVEL
DRIVEN AS MID AND UPPER LEVEL RIDGE SLOWLY TRANSLATES EAST.
TEMPS WILL COOL TO THE 30S AND LOWER 40S. RADIATIONAL COOLING
CONDITIONS NOT EXPECTED IN LIGHT EAST FLOW AND AMPLE CLOUD COVER.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
LEANED TOWARD EC/NAM/SREF THIS TIME FRAME AS GFS DEPICTS ANOMALOUS
LOWER AND SFC LEVEL LOW PRESSURE SAT AND SAT NIGHT...WHICH IS AN
OUTLYING SOLUTION.
LOCAL AREA WILL EVENTUALLY BE SANDWICHED BETWEEN STRONG HIGH
PRESSURE OVER SOUTHEAST CANADA AND LOW PRESSURE TO OUR SOUTH.
INCREASING WINDS THE RESULT THROUGH SAT NIGHT...ALTHOUGH FEEL WIND
ADVISORY CRITERIA TYPE WINDS FALL JUST SHORT.
MID WEST UPPER LOW EVENTUALLY MOVES EAST TOWARD THE EAST COAST
THROUGH THE PERIOD. IMPRESSIVE MOISTURE FEED IN THE SOUTHERN
STREAM...SEEN ON WATER VAPOR...WILL FEED THIS HIGHLY ANOMALOUS SYSTEM.
RAIN SHOULD INCREASE IN COVERAGE AS THE DAY PROGRESSES FRIDAY AS
EAST/SOUTHEAST FLOW INCREASES AND RIDGE AXIS ALOFT MOVES EAST. DRIER
AIR INITIALLY FOR LOCATIONS TO THE NORTH AND EAST CLOSER TO THE
HIGH...WILL DELAY STEADIER PRECIP FRIDAY.
DEEP MID AND UPPER LEVEL SOUTHERLY FLOW FRIDAY NIGHT AND SATURDAY
WILL MOISTEN THESE LAYERS IN CONJUNCTION WITH ALREADY SATURATED LOW
LEVELS DUE TO PERSISTENT AND NOW STRONG BOUNDARY LAYER FLOW.
STACKED LOW BY FRIDAY NIGHT EXPECTED TO BE OVER THE OHIO VALLEY...WITH
EMBEDDED SHORTWAVES ROTATING AROUND IT. STRONG ISENTROPIC LIFT AT
THIS POINT...ALONG WITH LOW/MID LEVEL FRONTOGENESIS WILL SET THE
STAGE FOR RAIN...HEAVY AT TIMES. HEAVIEST RAIN OCCURS SAT AND SAT
NIGHT AS DEEP LOW APPROACHES.
BY SUNDAY...THE LOW WILL PASS JUST SOUTH OF THE AREA. BEST LIFT AT
THAT TIME APPEARS TO PUSH TO THE NORTH...BUT LINGERING LIGHT RAIN
LIKELY.
SEE HYDROLOGY SECTION FOR DETAILS ON POTENTIAL RAINFALL...BUT 2 TO 4
INCHES QUITE POSSIBLE WITH THIS EVENT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
RAIN SHOULD CONTINUE INTO SUNDAY NIGHT-MON AS THE COASTAL STORM
SLOWLY PULLS AWAY FROM THE AREA. ECMWF AND GEFS MEAN CONTINUE TO BE
SLOWER IN THIS REGARD THAN THE OPERATIONAL GFS AND WERE FOLLOWED
MORE CLOSELY. FAIR WX WILL THEN FOLLOW FOR TUE-THU...WITH A DRY BACK
DOOR COLD FROPA TUE-TUE NIGHT...AND ONLY SLIGHT CHANCE POP WITH
ANOTHER BACK DOOR COLD FROPA THU MORNING. TEMPS LOOK TO REMAIN NEAR
TO SLIGHTLY ABOVE NORMAL INTO THE END OF NEXT WEEK.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
E/SE FLOW AROUND 10 KT WITH AN INVERSION BASED AROUND 1 KFT HAS
ALLOWED MVFR CIGS TO REMAIN ACROSS THE NYC TERMINALS. WITH THE
TRAJECTORY OF HIGHER DEW POINT AIR ACROSS THE WATERS...SEE NO
REASON FOR THESE CIGS TO NOT REMAIN...BUT THERE MAY BE A BRIEF
EPISODE WHERE CIGS GO VFR. THIS HAS BEEN A VERY CHALLENGING
FORECAST WITH VFR COND JUST TO THE WEST OF THE NYC TERMINALS.
ONSHORE FLOW AND DEEPENING LOW-LEVEL MOISTURE WILL RESULT IN IFR
CIGS ACROSS THE NYC TERMINALS TONIGHT...BUT TO THE NE ACROSS LI AND
CT...THERE MAY BE ENOUGH DRY AIR IN THE LOW LEVELS TO KEEP CIGS
FROM DROPPING BELOW MVFR. MVFR VSBYS IN DZ AFTER 04Z.
ON FRI...CIGS/VSBYS WILL BE RIGHT AROUND THE MVFR/IFR THRESHOLD.
THE MAGNITUDE OF THE SFC HIGH TO THE NORTH WILL BE THE ULTIMATE
FACTOR...BUT REGARDLESS CIGS LOOK TO BE BELOW 2 KFT.
E WINDS 5 TO 10 KT THIS AFT BACK AROUND TO THE E/NE OVERNIGHT...
GRADUALLY STRENGTHENING TOWARD DAYBREAK....THEN E AT 10 TO 15 KT
WITH GUST TO AROUND 20 KT 12-18Z FRI.
KJFK AFTN HOURLY WIND FORECAST IN SUPPORT OF RUNWAY CONSTRUCTION
ALL WIND DIRECTIONS ARE TRUE...ADD 13 DEGREES FOR MAGNETIC
11/19Z 11010KT
11/20Z 11010KT
11/21Z 10009KT
11/22Z 10007KT
11/23Z 09007KT
12/00Z 08007KT
12/01Z 06007KT
12/02Z 06008KT
12/03Z 06008KT
OUTLOOK 18Z FRIDAY THROUGH TUESDAY...
FRIDAY THROUGH SATURDAY NIGHT...IFR IN RAIN AND FOG. INCREASING
EASTERLY FLOW WITH 30 PLUS KT GUSTS LATE FRIDAY NIGHT INTO
SATURDAY NIGHT. LLWS ALSO LIKELY.
SUNDAY THROUGH MONDAY...IFR CONDITIONS LIKELY INTO SUN NIGHT...THEN
CONDITIONS IMPROVING TO VFR ON MON. DIMINISHING WINDS MONDAY.
TUE...VFR.
&&
.MARINE...
EASTERLY WINDS TONIGHT WILL INCREASE AS THE PRESSURE GRADIENT
TIGHTENS OVERNIGHT THROUGH SATURDAY. EXPECT SCA CONDITIONS ALL WATERS
BY FRIDAY MORNING...THEN POTENTIAL GALES FRI NIGHT AND SAT. WINDS
SHOULD DIMINISH SUNDAY AS SFC LOW PRESSURE APPROACHES AND PASSES
JUST SOUTH OF THE WATERS.
FOLLOWED WAVE WATCH III AND BUOY CLIMO CLOSELY THROUGH THE PERIOD.
WITH POWERFUL LOW APPROACHING THIS WEEKEND...SEAS OF 14 TO 18 FEET
QUITE POSSIBLE OVER THE OPEN OCEAN WATERS.
SCA CONDITIONS SHOULD CONTINUE ON MOST WATERS INTO SUNDAY NIGHT-MON
AS THE COASTAL STORM SLOWLY PULLS AWAY FROM THE AREA. OCEAN SEAS
WILL BE RATHER SLOW TO SUBSIDE THEREAFTER...WITH LONG PERIOD SWELLS
OVER 5 FT LINGERING THROUGH AT LEAST TUE MORNING AND POSSIBLY
THROUGH WED MORNING.
&&
.HYDROLOGY...
MAINLY LIGHT RAIN WILL INCREASE IN COVERAGE FRIDAY AND FRIDAY NIGHT.
THE HEAVIEST RAINFALL WILL OCCUR SATURDAY AND SATURDAY NIGHT. DO
EXPECT POTENTIAL FOR URBAN/POOR DRAINAGE AND RIVER/STREAM FLOODING
THROUGHOUT THE AREA SAT AND SAT. RESIDUAL RIVER FLOODING COULD
LINGER SUNDAY IF HEAVY RAINFALL MATERIALIZES AS ANTICIPATED.
FOR NE NJ AND THE LOWER HUDSON VALLEY...FLASH FLOOD GUIDANCE IS
LOWER (ESPECIALLY FOR NE NJ)...WITH WET ANTECEDENT CONDITIONS.
SATURATED GROUNDS TO THE EAST ACROSS LI AND SRN CT HAVE RESULTED
IN HIGH WATER TABLES. THESE SATURATED GROUNDS WILL BE UNABLE TO
ABSORB THE RAINFALL...AND POOR DRAINAGE/BASEMENT FLOODING QUITE
POSSIBLE.
&&
.TIDES/COASTAL FLOODING...
A PERSISTENT EASTERLY FLOW...STEADILY INCREASING THROUGH
SATURDAY...AND INCREASING ASTRONOMICAL TIDES DUE TO AN APPROACHING
NEW MOON...MAY RESULT IN WIDESPREAD MINOR TO LOCALLY MODERATE
COASTAL FLOODING DURING THE HIGH TIDE CYCLES ON SATURDAY NIGHT.
TIDAL DEPARTURES OF 2 TO 2 1/2 FEET ON THE ON THE ATLANTIC AND 3 TO
4 FT ON LONG ISLAND SOUND ARE FORECAST FOR THE SATURDAY NIGHT HIGH
TIDE CYCLES. THESE LEVELS WILL PUT PARTS OF WESTERN LI SOUND OVER
MODERATE BENCHMARKS. THIS AREA WILL NEED TO BE MONITORED CLOSELY FOR
A POTENTIAL COASTAL FLOOD WATCH. ON THE ATLANTIC SIDE...ANY MODERATE
COASTAL FLOODING WILL LIKELY BE CONFINED TO THE SOUTH SHORE BACK
BAYS OF WESTERN LI.
IN ADDITION...BEACH EROSION IS LIKELY FOR THE SOUTH SHORE BEACHES
WITH HIGH SURF FROM EASTERLY SWELLS. SEAS ON THE OCEAN ARE FORECAST
TO RANGE FROM 15 TO 18 FEET SATURDAY NIGHT INTO SUNDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM SATURDAY MORNING THROUGH SUNDAY MORNING FOR
CTZ005>012.
NY...FLOOD WATCH FROM SATURDAY MORNING THROUGH SUNDAY MORNING FOR
NYZ067>081.
NJ...FLOOD WATCH FROM SATURDAY MORNING THROUGH SUNDAY MORNING FOR
NJZ002>006-011.
MARINE...GALE WATCH FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON FOR
ANZ330-335-338-340-345-350-353-355.
SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EST FRIDAY FOR ANZ330-
335-338-340-345-350-353-355.
&&
$$
SYNOPSIS...PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...BG
AVIATION...DW
MARINE...BG/PW
HYDROLOGY...PW
TIDES/COASTAL FLOODING...DW