000
FXUS61 KOKX 191147
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
747 AM EDT FRI MAR 19 2010
.SYNOPSIS...
WEAK HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH SATURDAY. A BACK
DOOR COLD FRONT WILL DROP INTO THE AREA SATURDAY NIGHT AND
DISSIPATE ON SUNDAY. LOW PRESSURE TAKING SHAPE OVER THE PLAINS
STATES AND MISSISSIPPI VALLEY THIS WEEKEND WILL THEN APPROACH
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A BACK DOOR COLD FRONT STRETCHING FROM UPSTATE NEW YORK TO JUST E
OF BOSTON SHOULD REMAIN NORTH/EAST OF THE AREA TODAY. ANOTHER SUNNY
DAY IS COMING UP. NAM INDICATES SLIGHTLY LESS VERTICAL MIXING THAN
YESTERDAY...BUT WITH WARMER H8 TEMPS TODAY SHOULD BE A TOUCH WARMER
THAN YESTERDAY...WITH LOWER 70S IN MOST OF THE LOWER ELEVATIONS FROM
NYC NORTH/WEST...AND MID/UPPER 60S NEAR SOUTH FACING SHORES AND IN
THE HIGHER ELEVATIONS. WITH MEAN BOUNDARY LAYER FLOW MORE WSW
TODAY...SEA BREEZES SHOULD START A LITTLE EARLIER AND PUSH A
LITTLE FARTHER INLAND...WITH COOLING LATE DAY TEMPS ACROSS MOST OF
LONG ISLAND AND COASTAL CT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
A WEAK SFC TROUGH WILL MOVE INTO THE AREA TONIGHT AND REMAIN
THROUGH SAT. WITH AIR MASS SO DRY...DO NOT EXPECT MUCH NI THE WAY
OF CLOUDS/PRECIP WITH THIS FEATURE. URBAN HEAT ISLAND EFFECT WILL
KEEP MINS IN THE LOWER 50S IN MOST OF NYC...BUT RADIATIONAL
COOLING VIA MOSTLY CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPS
TO DROP INTO THE UPPER 30S AND 40S ELSEWHERE.
AIR MASS WILL REMAIN DRY AND H8-10 THICKNESSES ON SAT WILL BE
SIMILAR TO THOSE TODAY AS UPPER LEVEL RIDGING MOVES OVERHEAD...
SO SAT SHOULD BE A CARBON COPY OF TODAY...WITH HIGH TEMPS AGAIN
FROM THE MID 60S TO LOWER 70S. HIGH AND MID LEVEL CLOUDS WILL
START INCREASE DURING SAT NIGHT AS THE UPPER LEVEL RIDGE AXIS
MOVES EAST...ALLOWING A MID LEVEL SHORTWAVE TO APPROACH FROM THE
SW. STRONGER FORECAST UPPER LEVEL CONFLUENCE AND SFC HIGH
PRESSURE OVER QUEBEC WILL ALSO ALLOW A BACK DOOR COLD FRONT TO
MOVE INTO THE AREA. LOWS SAT NIGHT SHOULD BE A LITTLE MILDER...
RUNNING FROM THE LOWER 40S WELL INLAND TO LOWER 50S AGAIN IN NYC.
THE COMBINATION OF THE APPROACHING MID LEVEL SHORTWAVE AND WEAK
MID LEVEL ISENTROPIC LIFT/ELEVATED CAPE MAY GENERATE A FEW LIGHT
SHOWERS ON SUNDAY...MAINLY FROM NYC NORTH/WEST AND MAINLY IN THE
MORNING. MEANWHILE...AS HIGH PRESSURE MOVES OFF THE NEW ENGLAND
COAST AND LOW PRESSURE MOVES INTO THE OHIO VALLEY...THE FRONT WILL
LIFT NORTH EXCEPT PERHAPS ACROSS EASTERN SECTIONS...WITH LOW LEVEL
FLOW BECOMING MORE SE. THE COMBO OF CLOUDS AND ONSHORE FLOW SHOULD
KEEP TEMPS COOLER...WITH UPPER 60S IN NORTHEAST NJ...LOWER/MID 60S
MOST ELSEWHERE...AND UPPER 50S ACROSS MOST OF LONG ISLAND AND
EASTERN CT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
SOUTHERN STREAM DEVELOPING LOW THE FOCUS OF THE LONG TERM EARLY
IN THE PERIOD. SYSTEM IS CLOSED OFF OVER THE SOUTHEASTERN STATES
AT THE START OF THE PERIOD...AND CONTINUES TO PROGRESS IN THE
UPPER TROUGH...BUT SLOWLY. THE SYSTEM WILL APPROACH ON MON AND
THEN PASS JUST S OF THE AREA MON NIGHT/TUE...WITH LIKELY POP
ACROSS THE BOARD FOR MON/MON NIGHT AND HIGHER CHANCE POP FOR TUE.
FCST SOUNDINGS INDICATE MORE OF A STRATIFORM RAIN EVENT WITH
LITTLE IF ANY CHANCE FOR THUNDER. LOW LEVEL JET OFF THE COAST AND
SOUTH OF THE AREA MON WILL ENHANCE PRECIPITATION. TOO EARLY TO
DETERMINE EXACTLY WHERE THIS WILL SET UP...BUT POTENTIAL FOR AT
LEAST AN INCH OF RAIN LOOKS HIGH ATTM.
STRONGEST WINDS WILL BE ON THE BACK SIDE OF THE LOW LATE TUE INTO
TUE NIGHT...WITH GUSTS AROUND 30 KT. AS THE LOW PULLS EAST ON
WED...WINDS WILL BE DIMINISHING AS HIGH PRESSURE BUILDS IN.
A COLD FRONT WILL APPROACH FROM THE NORTH NEXT THU. THERE COULD BE
SOME INSTABILITY AHEAD OF THE FRONT...AND WITH EXPECTED LATE DAY
PASSAGE...MENTIONED AFTERNOON THUNDER.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR. AGAIN SEA BREEZE DEVELOPMENT FORECAST FOR THE NYC TERMINALS
EXCEPT FOR KEWR TODAY. LIGHT AND VARIABLE WINDS TO START THIS
MORNING BECOMING W/SW AT 5 TO 8 KT. THE ONE CAVEAT HERE IS THAT
THE FLOW THIS MORNING LOOKS LIGHT ENOUGH TO GO WITH A NE WIND OFF
THE EAST RIVER AT KLGA.
LIGHT SW FLOW THIS EVENING VEERING AROUND TO THE W WITH A WEAK SFC
TROF PUSHING THROUGH BY 12Z SAT.
KJFK AFTN HOURLY WIND FORECAST IN SUPPORT OF RUNWAY CONSTRUCTION
ALL WIND DIRECTIONS ARE TRUE...ADD 13 DEGREES FOR MAGNETIC
19/18Z 19012KT
19/19Z 19012KT
19/20Z 19013KT
19/21Z 19014KT
19/22Z 20012KT
19/23Z 21009KT
20/00Z 22006KT
20/01Z 22005KT
20/02Z 22004KT
OUTLOOK 12Z SAT THROUGH TUE...
SAT-SUN...VFR. AFTERNOON SEA BREEZE LIKELY ON SAT.
SUN NIGHT-MON...SUB-VFR LIKELY WITH GUSTY SOUTHERLY WINDS.
TUE...SUB-VFR WITH IMPROVEMENT LATE TO VFR. GUSTY NW WINDS TO
IN THE AFT/EVE.
&&
.MARINE...
TRANQUIL CONDITIONS EXPECTED THROUGH THE WEEKEND...WITH SEAS
AROUND 1 FT ON THE SOUND...NY HARBOR AND BAYS...AND 3 FT OR LESS
ON THE OCEAN.
SUNDAY NIGHT THROUGH TUE...INCREASING SOUTHERLY FLOW AHEAD OF AN
APPROACHING LOW WILL BUILD SEAS TO SMALL CRAFT ADVISORY LEVELS ON
THE OCEAN ON MON....WHERE THEY WILL LIKELY REMAIN THROUGH TUE.
SEAS WILL BE SLOWLY SUBSIDING TUE NIGHT AS WINDS SHIFT TO THE NW.
SMALL CRAFT ADVISORY LEVEL GUSTS POSSIBLE BEHIND THE LOW
TUE NIGHT.
&&
.HYDROLOGY...
DRY THROUGH THE WEEKEND. THE NEXT STORM SYSTEM WILL IMPACT THE
REGION SUN NIGHT THROUGH TUE...POSSIBLY PRODUCING MODERATE TO
HEAVY RAIN AT TIMES. POTENTIAL FOR AN INCH OF RAIN IS HIGH...BUT
THERE IS SOME UNCERTAINTY AS TO WHETHER HIGHER AMOUNTS WILL OCCUR.
THE SITUATION WILL NEED TO BE CLOSELY MONITORED DUE TO HIGH RIVER
AND STREAM LEVELS ACROSS THE INTERIOR.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BG
NEAR TERM...BG
SHORT TERM...BG
LONG TERM...BG/MET
AVIATION...DW
MARINE...DW
HYDROLOGY...BG
