Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 200545
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
145 AM EDT SAT SEP 20 2014

.SYNOPSIS...
HIGH PRESSURE TO OUR NORTH MOVES EAST OVER THE ATLANTIC ON SATURDAY.
A COLD FRONT CROSSES THE AREA SUNDAY NIGHT. HIGH PRESSURE RETURNS
ON MONDAY AND REMAINS IN CONTROL THROUGH THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
FORECAST UPDATE TO REFLECT LATEST OBSERVATIONS. OTHERWISE NO
SIGNIFICANT CHANGES WERE MADE.

HIGH PRESSURE OVER THE GULF OF MAINE RESULTING IN SE SURFACE FLOW.
WITH THE FLOW GOING SE...STRATUS HAS EXPANDED INTO THE REGION.
STILL SOME UNCERTAINTY AS TO JUST HOW EXPANSIVE THE STRATUS GETS.

WITH WATER TEMPS NEAR 70...DO NOT BELIEVE FOG IS AN ISSUE.

TEMPS WILL BE AFFECTED BY THE STRATUS AND ITS TIMING. HAVE STAYED
CLOSE TO MOS AND PREVIOUS FORECAST DUE TO UNCERTAINTY WITH THE
CLOUDS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
SOUTHERLY FLOW THROUGH THE PERIOD WITH POSITIVE LOW LEVEL MOISTURE
ADVECTION. MORNING CLOUDS GIVE WAY TO SUN BY AFTERNOON.
UNCERTAINTY THOUGH IN THE MAX TEMPS WITH NAM MOS A GOOD 5 DEGREES
HIGHER THAN GFS. WITH UNCERTAINTY IN AMOUNT OF SUN...HAVE STAYED
CLOSE TO PREVIOUS FORECAST WHICH IS BASICALLY A COMPROMISE OF THE
NAM AND GFS MOS.

EXPECT WIDESPREAD STRATUS SATURDAY NIGHT AND POTENTIALLY SOME FOG
ALONG THE COAST. WITH OCEAN TEMPS STILL NEAR 70 THOUGH...DID NOT
INCLUDE THE FOG IN THE FORECAST. WHILE SOME DETERMINISTIC 12Z RUNS
(NAM, CMC GEM) SUGGEST MEASURABLE PCPN...MEASURABLE QPF IN THE
SREF IS ONLY AROUND 10 PERCENT. THUS USED SLIGHT POPS (LIGHT RAIN)
FOR THE EASTERN HALF OF THE CWA...BUT DID GO WITH DRIZZLE (ALL
AREAS) AS NWP PROFILES SUGGEST MOISTURE TO 700 HPA AS SUBSIDENCE
INVERSION LIFTS.

THERE WILL BE A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN
FACING BEACHES SATURDAY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
POTENTIAL FOR UNSETTLED WEATHER SUNDAY THROUGH SUNDAY NIGHT

MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT WITH FORECASTS OF THE
MASS FIELDS SUNDAY THROUGH SUNDAY NIGHT. THEY SHOW LOW PRESSURE
DEVELOPING OFF THE SE COAST THEN MOVING NE AS IT IS PICKED UP BY THE
APPROACHING DIGGING AND AMPLIFYING UPPER LVL SHORT WAVE. THERE ARE
DIFFERENCES IN THE AMPLIFICATION AND TIMING OF THIS SHORT WAVE WHICH
WILL IMPACT THE POSITION AND INTENSITY OF THIS OFFSHORE LOW. AT THIS
TIME...IT APPEARS THAT LONG ISLAND AND SOUTHERN CT WILL BE MOST
VULNERABLE WITH THE HIGHEST CHANCES FOR RAIN.

ADDITIONALLY...SCT SHOWERS AND TSTMS ARE POSSIBLE AHEAD OF THE
APPROACHING COLD FRONT. IF ADEQUATE INSTABILITY DEVELOPS...A FEW
STORMS COULD PRODUCE GUSTY WINDS WEST AND NORTH OF NYC LATE IN THE
DAY.

MONDAY THROUGH FRIDAY WILL BE DOMINATED BY A COOL CANADIAN HIGH
PRESSURE WITH TEMPERATURES AVERAGING AT LEAST 5 DEGREES BELOW
NORMAL. NO RAIN IS FORECAST DURING THIS TIME AS DRYING CONTINUES.

&&

.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE CONTINUES TO DRIFT EASTWARD INTO THE ATLANTIC
TODAY...WHILE A WEAK COASTAL WAVE AND COLD FRONT APPROACH LATE
TONIGHT INTO SUNDAY.

5 TO 10 KT SE WINDS THIS MORNING...INCREASING AND BECOMING GUSTY
S/SE THIS AFTERNOON. WINDS SHOULD GRADUALLY WEAKEN AND BACK E/NE
TONIGHT.

MVFR STRATUS DEVELOPMENT LIKELY THIS MORNING. THERE IS UNCERTAINTY
WITH THIS AND START/END TIMES WILL VARY FOR INDIVIDUAL SITES WITH
OCCASIONAL FLUCTUATION BETWEEN MVFR AND VFR QUITE POSSIBLE AS
WELL. CIGS EXPECTED TO GRADUALLY RISE TO VFR THIS AFTERNOON AND
SCATTER...BUT OCCASIONAL BKN CIGS POSSIBLE ACROSS NYC METRO AND
WESTERN TERMINALS.

MVFR CONDS LIKELY TO RE-DEVELOP LATE THIS EVENING INTO
TONIGHT...WITH POTENTIAL FOR PATCHY DRIZZLE OR LIGHT RAIN.

.OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...
.LATE SATURDAY NIGHT-SUNDAY...MVFR...LOCALLY IFR CONDS AFTER 04Z
WITH PATCHY DRIZZLE OR LIGHT RAIN SHOWER. CONDITIONS IMPROVE TO
VFR IN THE MORNING. ISOLATED SHOWERS OR THUNDERSTORM IN THE
AFTERNOON.
.SUNDAY NIGHT...SHOWERS ENDING WITH CONDITIONS IMPROVING TO VFR.
.MONDAY-WEDNESDAY...VFR.

&&

.MARINE...
SE WINDS TONIGHT INTO SATURDAY AS SEAS SLOWLY SUBSIDE ON THE
OCEAN.

WINDS INCREASE SLIGHTLY LATE SATURDAY WITH GUSTS TO AROUND 20 KT.

SUNDAY NIGHT THROUGH MONDAY NIGHT...WINDS WILL INCREASE CAUSING SEAS
TO BUILD...APPROACHING SMALL CRAFT ADVISORY LEVELS OF 25 KT AND 5
FT ACROSS THE ATLANTIC COASTAL WATERS. SW WINDS 15-20 KT SUNDAY
NIGHT WILL SHIFT FROM THE NW BY SUNRISE MONDAY AND CONTINUE
THROUGH MONDAY EVENING. SEAS WILL BUILD TO 3 TO 5 FT.

OTHERWISE...WINDS AND SEAS WILL BE TRANQUIL THROUGH TUE NIGHT.

INCREASING EAST WINDS WILL DEVELOP BY WED AS SEAS GRADUALLY BUILD AS
STRONG HIGH PRESSURE MOVES ACROSS NORTHERN NEW ENGLAND.

&&

.HYDROLOGY...
LESS THAN 1/4 INCH OF RAIN IS FORECAST SUNDAY THROUGH SUNDAY NIGHT
AS A LOW MOVES OFFSHORE FOLLOWED BY A COLD FRONT SUNDAY NIGHT.

OTHERWISE...DRY WEATHER IS FORECAST.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...JMC
SHORT TERM...
LONG TERM...GC
AVIATION...NV
MARINE...GC
HYDROLOGY...GC








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