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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KOKX 181348
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
948 AM EDT SAT MAY 18 2013

.SYNOPSIS...
HIGH PRESSURE WILL SLIDE EAST OF THE AREA TODAY AND MOVE FURTHER
OUT TO SEA TONIGHT. A WARM FRONT WILL APPROACH FROM THE MID ATLANTIC
STATES SUNDAY INTO SUNDAY NIGHT AND THEN PASS 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 PM THIS EVENING/...
-- Changed Discussion --
FORECAST UPDATED TO INCREASE CLOUD COVER TO MOSTLY CLOUDY/OVERCAST
FOR LATE THIS MORNING AND AFTERNOON FOR MOST OF THE CWA AS CLOUDS
CONTINUE TO STREAM INTO THE REGION. IN ADDITION...SOME LIGHT RAIN
SHOWERS HAVE BEEN DEVELOPING ALONG THE NY/PA BORDER AND ARE HEADED
TOWARD THE CWA. HAVE INCLUDED SLIGHT CHANCE POPS...MAINLY ACROSS
NJ...THE LOWER HUDSON VALLEY AND NYC. THOSE POPS MAY NEED TO BE
INCREASE LATER THIS MORNING OR EARLY AFTERNOON...BUT WOULD PREFER
TO SEE HOW THESE SHOWER EVOLVE OVER THE NEXT COUPLE OF HOURS.

OTHERWISE...HIGHS WILL BE IN THE UPPER 60S AND LOWER 70S.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE HIGH MOVES FURTHER OFFSHORE TONIGHT WITH CLOUD COVER GRADUALLY
INCREASING FROM SW TO NE. STRATUS MAY DEVELOP LATE TONIGHT BUT
STILL EXPECT DRY CONDS.

A WARM FRONT WILL APPROACH SUN AND SUN NIGHT FROM THE SW.
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 DRIZZLE AND AREAS OF FOG DEVELOPING.

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. LOOKS LIKE THE FRONT MOVES
THROUGH IN THE MORNING...AND WITH THE SURGE OF A MORE UNSTABLE AIR
MASS THUNDERSTORMS ARE POSSIBLE WITH ITS PASSAGE. THE POTENTIAL
FOR SCATTERED AFTERNOON CONVECTION ALSO EXISTS BUT THERE IS
UNCERTAINTY IN HOW MUCH CLEARING THERE WILL BE IN THE AFTN. IT IS
STILL TOO EARLY TO DISCUSS SEVERE WEATHER OR FLOOD POTENTIAL WITH
THIS ACTIVITY WITH UNCERTAINTY ON MAGNITUDE OF INSTABILITY AND
FORCING.

TEMPERATURES ON SUNDAY WILL BE SLIGHTLY BELOW NORMAL DUE TO CLOUD
COVER...OTHERWISE...THEY WILL BE NEAR NORMAL LEVELS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
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.

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.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE MOVES EAST OF THE AREA TODAY AND TONIGHT.

GENERALLY VFR TODAY WITH MAINLY MID AND HIGH CLOUDS TO CONTEND
WITH. SCATTERED CU EXPECTED. A BRIEF PASSING SHOWER CANNOT BE
RULED OUT IN NYC METRO VICINITY THIS AFTERNOON AND EVENING.

LIGHT AND VARIABLE WINDS EARLY THIS MORNING WILL INCREASE TO 5 TO 10
KTS AFTER 13-15Z...GENERALLY FROM THE SOUTH. WINDS INCREASE DURING
THE AFTERNOON AT A FEW COASTAL AIRPORTS SUCH AS KJFK.

MAINLY VFR CIGS ARE FCST THROUGH THE EVENING AS SOUTH TO
SOUTHEAST WINDS LIGHTEN. MVFR CIGS MORE LIKELY AFTER
MIDNIGHT...EXCEPT EASTERN TERMINALS.

.OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY...
.SUN...MVFR OR LOWER CIGS POSSIBLE IN SHOWERS. SE SFC WIND 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.

&&

.MARINE...
HIGH PRESSURE PASSES TO THE EAST OF THE WATERS...RESULTING IN A
SOUTHERLY FLOW THIS WEEKEND. SMALL CRAFT ADVISORY THRESHOLDS ARE NOT
EXPECTED UNTIL POSSIBLY SUNDAY NIGHT OR MONDAY AS WINDS INCREASE AND
OCEAN SEAS BUILD DUE TO THE PERSISTENT SOUTHERLY FETCH.

A WARM FRONT MOVES NORTH OF THE WATERS MONDAY...AND SHOULD REMAIN TO
THE NORTH THROUGH TUESDAY. THE FRONT MAY SAG SOUTH AGAIN AND REMAIN
IN THE VICINITY OF THE WATERS THROUGH MID WEEK.

SOUTH TO SOUTHWEST WINDS PERSIST INTO TUESDAY. ONCE THE FRONT
SETTLES BACK TOWARD THE WATERS...WINDS LIGHTEN AND MAY
SHIFT...DEPENDING ON HOW FAR SOUTH THIS FRONT MOVES. STAY TUNED.

&&

.HYDROLOGY...
NO SIGNIFICANT RAINFALL IS EXPECTED THROUGH SUN 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...
NEAR TERM...BC
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...