-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KOKX 172047
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
447 PM EDT FRI MAY 17 2013

.SYNOPSIS...
HIGH PRESSURE BUILDS IN TONIGHT...THEN MOVES EAST SATURDAY AND
SATURDAY NIGHT. A WARM FRONT APPROACHES FROM THE MID ATLANTIC
STATES SUNDAY INTO SUNDAY NIGHT AND THEN PASSES TO THE NORTH ON
MONDAY. THE FRONT THEN REMAINS IN CLOSE PROXIMITY TO THE AREA
THROUGH THE WEEK UNTIL A COLD FRONTAL PASSAGE OCCURS LATE IN THE
WEEK OR EARLY WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
-- Changed Discussion --
SURFACE HIGH PRESSURE BUILDS OVER THE AREA TONIGHT.
MEANWHILE...SOME HIGH LEVEL CLOUDS ARE EXPECTED TO SPILL OVER THE
UPPER LEVEL RIDGE. NORTHWEST WINDS WILL GRADUALLY LIGHTEN AND
BECOME LIGHT AND VARIABLE WITH HIGH PRESSURE BUILDING OVERHEAD. THE
COMBINATION OF THE LIGHT WINDS AND THIN HIGH LEVEL CLOUDS SHOULD
RESULT IN SOME GOOD RADIATIONAL COOLING...MAINLY AWAY FROM NYC.
FORECAST LOWS ARE EXPECTED TO DROP INTO THE UPPER 30S AND
40S...WHILE LOWS IN THE NYC METRO REMAIN IN THE LOWER 50S.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
A WEAK TROUGH/VORT MAX APPROACHES THE REGION SATURDAY AND SATURDAY
NIGHT. EXPECTING CLOUDS TO INCREASE THROUGH THE DAY...HOWEVER WITH
THE RIDGING AND SURFACE HIGH NEARBY...THINKING THAT SATURDAY AND
SATURDAY NIGHT WILL REMAIN DRY.

AN ONSHORE FLOW ON SATURDAY WILL RESULT IN COOLER TEMPERATURES NEAR
THE COAST...AND WARMER READINGS ACROSS THE INTERIOR AWAY FROM THE
WATER. HIGHS WILL CLIMB INTO THE 70S...A FEW DEGREES COOLER NEAR THE
SOUTH FACING SHORES. SATURDAY NIGHT...LOWS WILL FALL INTO THE UPPER
40S AND 50S.

USED A MAV/MET BLEND THROUGH THE SHORT TERM PERIOD.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --
THERE ARE STILL SOME DISCREPANCIES AMONGST THE GLOBAL MODELS WITH
THE MAGNITUDE OF UPPER TROUGHING ACROSS EASTERN CANADA AS AN UPPER
RIDGE OVER THE MISSISSIPPI VALLEY TRANSLATES EAST THROUGH THE
UPCOMING WEEK. THE INTERACTION OF THE EASTERN CANADA TROUGHING AND
CENTRAL US TROUGHING WILL DETERMINE THE MAGNITUDE OF EAST COAST
RIDGING FOR THE MIDWEEK. MODELS ARE THEN SIGNALING A RETURN TO EAST
COAST TROUGHING FOR THE WEEKEND AS EAST COAST RIDGING BUILDS
OFFSHORE INTO THE WESTERN ATLANTIC.

SUN INTO SUN NIGHT WILL FEATURE A MODERATING CANADIAN MARITIME
AIR MASS AS HIGH PRESSURE SLIDES OFFSHORE AND A WARM FRONT APPROACHES
FROM THE SOUTH. INCREASING CLOUD COVER AND LATE DAY SHOWER ACTIVITY
ARE EXPECTED IN THIS WAA PATTERN. THE CONTINUATION OF THE
INCREASINGLY MOIST SE FLOW INTO SUN NIGHT POINTS TOWARDS CLOUDY
CONDITIONS WITH LIGHT RAIN...PATCHY FOG AND DRIZZLE.

MODELS IN DECENT AGREEMENT WITH A WEAK SHORTWAVE APPROACHING SUN
NIGHT INTO MONDAY...WITH A WARM FRONTAL PASSAGE ON MONDAY...AND
REGION WARM SECTORED INTO TUESDAY. TIMING OF WARM FRONTAL PASSAGE IS
UNCERTAIN ON MONDAY...BUT WITH SURGE OF A MORE UNSTABLE AIR MASS
THUNDERSTORMS ARE POSSIBLE WITH THE WARM FRONTAL PASSAGE. IF THE
REGION GETS WARM SECTORED BY MON AFTERNOON...THERE IS POTENTIAL FOR
SCATTERED AFTERNOON CONVECTION. IT IS STILL TOO EARLY TO DISCUSS
SEVERE WEATHER OF FLOOD POTENTIAL WITH THIS ACTIVITY WITH
UNCERTAINTY ON MAGNITUDE OF INSTABILITY AND FORCING.

ON TUESDAY...MODELS ARE IN GOOD AGREEMENT WITH AN UNSEASONABLY WARM
AND HUMID AIR MASS WORKING INTO THE REGION. DEPENDING ON THE LOCATION
OF THE FRONTAL BOUNDARY...FAVORABLE INSTABILITY AND WIND FIELDS
PRESENT THE POTENTIAL FOR SOME STRONG TO SEVERE CONVECTION
AHEAD/ALONG THIS BOUNDARY. LOCATION OF THE BOUNDARY WILL BE KEY.

THEN FOR THE MID-LATE WEEK PERIOD THE INTERACTION OF THE EARLIER
MENTIONED UPPER FEATURES WILL BE CRITICAL TO THE LOCATION OF THE
FRONTAL BOUNDARY AND WHETHER THE REGION REMAINS UNDER AN
UNSEASONABLY WARM AND UNSTABLE AIR MASS WED-FRI...OR WHETHER THE
PICTURE IS MORE MUDDLED WITH A FRONTAL BOUNDARY MEANDERING ACROSS
THE REGION FOR MUCH OF THE TIME PERIOD WITH CLOUDS AND SEASONABLE TO
SLIGHTLY BELOW SEASONABLE TEMPS.

REGARDLESS OF WHERE THE WARM FRONT ENDS UP...IF THIS BOUNDARY REMAIN
CLOSE TO THE REGION...SHORT WAVES AT THE SOUTHERN EDGE OF THE
WESTERLIES MAY ALLOW FOR CONVECTIVE COMPLEXES TO FORM AND TRACK WEST
TO EAST ALONG THIS BOUNDARY THROUGH THE MIDWEEK PERIOD. THESE WOULD
BRING THE THREAT FOR HEAVY RAIN AND SEVERE WEATHER...BUT IT IS TOO
FAR OUT DISCUSS SPECIFICS.
-- End Changed Discussion --

&&

.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
VFR THROUGH THE TAF PERIOD AS HIGH PRESSURE BUILDS IN FROM THE
GREAT LAKES.

NW SFC FLOW WEAKENS THROUGH THE EVENING. STILL A CHANCE FOR A LATE
DAY SEA BREEZE...BUT NO LONGER LIKELY. SEA BREEZE DID DEVELOP AT
KGON. TAFS AMENDED.

 NY METRO ENHANCED AVIATION WEATHER SUPPORT...

DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT:  HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)

KEWR FCSTER COMMENTS: SEA BREEZE NO LONGER EXPECTED.

KJFK FCSTER COMMENTS: SEA BREEZE COULD STILL DEVELOP LATE. WILL
CONTINUE TO MONITOR. AMENDMENTS POSSIBLE FOR A WIND SHIFT TO THE
SOUTH IF IT DOES FORM.

KLGA FCSTER COMMENTS: SEA BREEZE NO LONGER EXPECTED.

KTEB FCSTER COMMENTS: SEA BREEZE NO LONGER EXPECTED.

KHPN FCSTER COMMENTS: AMENDMENTS NOT SCHEDULED.

KISP FCSTER COMMENTS: SEA BREEZE NOT EXPECTED.

.OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
.SAT AFTN...VFR.
.SUN...VFR CIG. SE SFC WND AROUND 15 KT.
.SUN NGT-MON...SE SFC FLOW WITH IFR CIG INTO MON MORNING. SHOWERS.
SCATTERED AFTN TSTMS.
.TUE AND WED...CHANCE OF SUB-VFR CONDS IN SHOWERS AND TSTMS.
-- End Changed Discussion --

&&

.MARINE...
SURFACE HIGH PRESSURE NEAR THE AREA WATERS WILL KEEP CONDITIONS
BELOW SMALL CRAFT LEVELS THROUGH SATURDAY NIGHT. WINDS WILL BECOME
LIGHT AND VARIABLE TONIGHT THEN GRADUALLY SHIFT TO THE
SOUTH-SOUTHEAST DURING THE DAY ON SATURDAY AND SATURDAY NIGHT.

A STRENGTHENING SE FLOW IS EXPECTED SUN INTO SUN NIGHT AHEAD OF AN
APPROACHING A WARM FRONT. MARGINAL SCA WINDS ARE POSSIBLE ON TE
OCEAN...BUT THIS FLOW SHOULD GRADUALLY BUILDS SEAS TO SCA LEVELS BY
SUN NIGHT. ONCE THE WARM FRONT MOVES NORTH ON MONDAY A PERSISTENT
SOUTHERLY FLOW SHOULD KEEP OCEAN SEAS AT SCA LEVELS. MARGINAL SCA
WINDS ARE POSSIBLE ON MONDAY...BUT WINDS SHOULD BE BELOW SCA LEVELS
FOR THE REMINDER OF THE EARLY TO MID WEEK PERIOD.

&&

.HYDROLOGY...
DRY WEATHER IS EXPECTED THROUGH SATURDAY NIGHT.

ALTHOUGH WIDESPREAD HEAVY RAIN EVENTS ARE NOT EXPECTED MON-
FRI...THUNDERSTORMS ARE POSSIBLE THROUGH THIS PERIOD...WHICH WOULD
BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...BC/NV
NEAR TERM...BC
SHORT TERM...BC
LONG TERM...NV
AVIATION...GC/TONGUE
MARINE...BC/NV
HYDROLOGY...BC/NV