000
FXUS61 KOKX 180543
AFDOKX

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

.SYNOPSIS...
HIGH PRESSURE BUILDS IN OVERNIGHT...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 THIS MORNING/...
FORECAST ON TRACK...ONLY MINOR CHANGES MADE TO REFLECT CURRENT
TRENDS.

SURFACE HIGH PRESSURE BUILDS OVER THE AREA TONIGHT WITH HIGH
LEVEL CLOUDS SPILLING OVER THE UPPER LEVEL RIDGE. LIGHT AND VARIABLE
WINDS WILL PREVAIL. 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.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
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 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. 

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.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
VFR TODAY AS HIGH PRESSURE MOVES EAST OF THE AREA.

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 MID AND HIGH CLOUDS ARE EXPECTED TODAY...WITH FEW TO 
SCATTERED CU.

VFR CIGS ARE FCST THROUGH THE EVENING AS SOUTH TO SOUTHEAST WINDS 
LIGHTEN.

.OUTLOOK FOR 06Z SATURDAY THROUGH WEDNESDAY...
.SAT NIGHT...CIGS POSSIBLY LOWERING TO MVFR.
.SUN...MVFR CIGS. 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.

&&

.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 THE 
OCEAN...BUT THIS FLOW SHOULD GRADUALLY BUILD 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.

&&

$$