000
FXUS61 KOKX 202105
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
505 PM EDT SAT MAR 20 2010
.SYNOPSIS...
WEAK HIGH PRESSURE WILL MOVE SLOWLY OFFSHORE TODAY. A WEAK COLD
FRONT DROP DOWN FROM THE NORTH AND APPROACH THE AREA. IT WILL
SLOWLY MOVE THROUGH THE REGION TONIGHT AND BECOME NEARLY
STATIONARY OVER THE REGION ON SUNDAY. A LARGE AREA OF LOW PRESSURE
OVER THE SOUTHERN PLAINS WILL SLOWLY MOVE NORTHEAST THROUGH EARLY
NEXT WEEK AND PASS SOUTHEAST OF LONG ISLAND MONDAY NIGHT AND
TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WEAK COLD FRONT FROM THE NORTH WILL MOVE ACROSS THE AREA TONIGHT
AND WILL BRING JUST AN INCREASE IN CIRRUS. THIS WILL MITIGATE
RADIATIONAL COOLING LATER TONIGHT. COLDER THAN NORMAL SPOTS IN
OUTLYING AREAS WILL COOL OFF FIRST THIS EVENING AS WINDS BECOME
LIGHT BEFORE CLOUD COVERAGE INCREASES.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
THE WEAK COLD FRONT WILL MOVE THROUGH BY SUNDAY MORNING AND WILL
STALL JUST SOUTH OF THE AREA. HIGH PRESSURE BUILDING INTO NORTHERN
NEW ENGLAND WILL ALLOW FOR WINDS TO BECOME MORE EASTERLY AND
INCREASE THE MOISTURE IN THE LOWER LEVELS. MORE CLOUDS WILL BE
DEVELOPING WITH THIS INCREASE IN MOISTURE BENEATH AN INVERSION.
THE EASTERLY FLOW WILL ALLOW FOR A GREATER INFLUENCE OF THE COOLER
SURROUNDING WATERS AND LOWER MAX TEMPS CAN BE EXPECTED.
THE STALLED FRONT WILL START TO LIFT NORTH OF THE AREA WITH WINDS
TURNING MORE SOUTHERLY FOR SUNDAY NIGHT. CLOUDS WILL CONTINUE TO
INCREASE WITH NOT AS COLD MIN TEMPS. MOST RAINFALL INDICATED BY
MODELS FOR SUNDAY WILL BE DISPLACED NORTH OF THE LOCAL REGION WITH
JUST A SLIGHT CHANCE OF SOME LIGHT RAIN FOR NORTHERN TIER OF THE
CWA. RAIN CHANCES INCREASE LATE SUNDAY NIGHT INTO MONDAY.
FOR MONDAY...THE CLOSED UPPER LEVEL LOW WILL BE MOVING FROM THE
SOUTHEAST TOWARDS THE MID-ATLANTIC WITH WARM AIR ADVECTION
INCREASING ALOFT. FLOW ALOFT AS SUCH WITH BE TURNING MORE
SOUTHWESTERLY. THIS WILL BRING ADDITIONAL MOISTURE INTO THE
ATMOSPHERE WITH LAYER PRECIPITABLE WATERS EXCEEDING 1 INCH BY
MONDAY AFTERNOON. ISOENTROPIC LIFTING WILL BE GETTING MORE
EFFICIENT BY THIS TIME AS WELL WITH RAIN DEVELOPING FROM WEST TO
EAST.
THE MAJORITY OF THE RAIN WILL FALL MONDAY NIGHT INTO TUESDAY
MORNING AS THE UPPER LEVEL LOW AND SURFACE LOW MOVE INTO THE
COASTAL PLAIN OF THE NORTHEAST. RAINFALL COULD BE HEAVY AT TIMES
WITH HIGHER OMEGA AND VORTICITY MOVING IN DOWNSTREAM OF THE LOW
PRESSURE SYSTEM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
LIGHT PRECIP SHOULD CONTINUE INTO TUE NIGHT AS THE LOW MOVES EAST OF
THE AREA. TEMPS COULD COOL DOWN ENOUGH VIA NORTHERLY FLOW IN ITS
WAKE TO ALLOW A CHANGE BACK TO WET SNOW IN THE HIGHER ELEVATIONS
NORTH/WEST OF NYC BEFORE PRECIP ENDS.
WX WILL THEN BE GENERALLY QUIET WED INTO THU NIGHT...WITH ONLY
SLIGHT CHANCE POP WED NIGHT AS A WEAKENING COLD FRONT MOVES
THROUGH...FOLLOWED BY HIGH PRESSURE OF PACIFIC ORIGIN...WITH TEMPS A
FEW DEGREES ABOVE NORMAL.
A COLD FRONT WILL MOVE THROUGH DURING FRI MORNING...WHILE A WEAK
SOUTHERN STREAM LOW MOVES THROUGH THE OHIO/TENNESSEE VALLEYS TOWARD
THE SOUTHERN MID ATLANTIC COAST. THE AREA WILL BE CLOSE TO THE
NORTHERN FRINGE OF THIS SYSTEM...WITH CHANCE POP FRI AFTERNOON INTO
SAT. WITH THE NEW AIR MASS BEING OF CANADIAN ORIGIN...PRECIP
BEGINNING AS RAIN COULD CHANGE BRIEFLY TO SNOW INLAND AND A
RAIN/SNOW MIX IN COASTAL SECTIONS OUTSIDE OF NYC LATE FRI
NIGHT-EARLY SAT MORNING.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
VFR WEATHER CONDITIONS WILL PERSIST THROUGH 18Z SUNDAY.
WINDS...AS A WEAK COLD FRONT MOVES SLOWLY SE TOWARD THE AREA...A SW
PRES GRADIENT BETWEEN THE FRONT AND A HIGH PRES SYSTEM OVER THE SOUTHEAST
U.S. WILL INCREASE. WIND DIRECTIONS WILL MAINLY RANGE FROM 220-240
DEGS WITH SUSTAINED SPEEDS 10-15 KT. ALTHOUGH NOT INCLUDED IN THE
LATEST TAF FORECASTS...ISOLATED WIND GUSTS OF 15-20 KT ARE
POSSIBLE UNTIL SUNSET.
WINDS WILL QUICKLY DECREASE AFTER SUNSET AND BECOME LIGHT AND
VARIABLE BETWEEN 01Z AND 03Z AT MOST TERMINALS.
THE COLD FRONT IS FORECAST TO MOVE SE OF THE AREA BETWEEN 06Z AND
09Z TONIGHT. LIGHT NE WINDS WILL DEVELOP WITH THE APPROACH OF
SUNRISE AS LOW LEVEL INSTABILITY BEGINS TO INCREASE.
SUNDAY...MID AND UPPER LVL CIGS WILL GRADUALLY LOWER BUT REMAIN
VFR AS LOW PRES BEGINS TO APPROACH THE AREA. LIGHT NE WINDS WILL
GRADUALLY BECOME SE AND INCREASE TO AROUND 10 KT SUNDAY AFTERNOON.
KJFK AFTN HOURLY WIND FORECAST IN SUPPORT OF RUNWAY CONSTRUCTION
ALL WIND DIRECTIONS ARE TRUE...ADD 13 DEGREES FOR MAGNETIC
20/21Z 20014KT
20/22Z 20013KT
20/23Z 21012KT
21/00Z 22010KT
21/01Z 22008KT
21/02Z 22007KT
OUTLOOK 18Z SUNDAY THROUGH THURSDAY...
SUN AFTN-NIGHT...VFR...MVFR POSSIBLY DEVELOPING AFT 06Z.
MON-TUE...SUB-VFR LIKELY.
TUE NIGHT...IMPROVING CONDITIONS WITH GUSTY NW WINDS.
WED...VFR CIGS WITH GUSTY NW WINDS.
THU...VFR.
&&
.MARINE...
A WEAK FRONT MOVES INTO THE WATERS FROM THE NORTH TONIGHT.
TRANQUIL WEATHER CONDITIONS ARE FORECAST THROUGH SUNDAY WITH SEAS
REMAINING MOSTLY BELOW 3 FEET ON THE OCEAN AND 1 FOOT OR LESS ON
THE SOUND.
FOR MONDAY AND TUESDAY...AN AREA OF LOW PRESSURE WILL MOVE SLOWLY
NORTHEAST TOWARD THE WATERS...RESULTING IN INCREASING EASTERLY
WINDS. THE LOW PASSES JUST SOUTH...THEN EAST LATER TUESDAY AND
WEDNESDAY. WINDS AND SEAS DURING THE TIMEFRAME LOOK TO STAY BELOW
SCA LEVELS.
SCA CONDITIONS SHOULD LAST ON THE OCEAN TUE NIGHT-WED
VIA THE COMBO OF N-NW FLOW ON THE BACK SIDE OF THE DEPARTING LOW
AND LEFTOVER SWELLS...THEN QUIET CONDITIONS ARE EXPECTED FROM WED
NIGHT-THU NIGHT.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH SUNDAY.
A WIDESPREAD RAINFALL IS POSSIBLE MONDAY THROUGH TUESDAY WITH
AMOUNTS RANGING FROM 1 TO 2 INCHES. MINOR URBAN FLOODING IS
POSSIBLE...BUT MORE IMPORTANTLY...RIVERS AND STREAMS ARE RUNNING HIGH
ACROSS NE NJ AND THE LOWER HUDSON VALLEY. RUNOFF FROM THIS STORM
COULD CAUSE SOME OF THEM TO EXCEED BANK FULL.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...BG
AVIATION...GC
MARINE...BG/JM
HYDROLOGY...JM
CLIMATE...
