Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 140138
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
938 PM EDT SUN APR 13 2014

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ANCHORED OFF THE COAST THROUGH MONDAY.
A COLD FRONT WILL APPROACH ON TUESDAY AND MOVE ACROSS TUESDAY
NIGHT...FOLLOWED BY BUILDING HIGH PRESSURE FROM THE WEST WEDNESDAY
INTO THURSDAY. THE HIGH WILL WEAKEN AND MOVE EAST ON FRIDAY...
ALLOWING A LOW PRESSURE SYSTEM TO APPROACH FROM THE SOUTHWEST
THIS WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
TEMPS WERE STILL IN THE LOWER 70S ALONG AND WEST OF THE HUDSON...BUT
WERE IN IN THE 60S MOST ELSEWHERE...AND 55-60 ACROSS SOUTHEAST
COASTAL CT AND LONG ISLAND. THESE SHOULD FALL TO A MORE UNIFORM
50S AREA-WIDE...IN LINE WITH 12Z GFS/NAM MOS AND 12Z NAM 2M TEMPS.
WILL NEED TO CONTINUE TO MONITOR THESE AS SOME AREAS ARE DROPPING
QUICKER THAN FORECAST.

MID AND HIGH LEVEL CLOUDS CONTINUE TO STREAM ACROSS. AS TEMPS COOL
AND MOISTURE DEEPENS BENEATH A SFC-BASED INVERSION...HYBRID
ADVECTION/RADIATION LOW STRATUS/FOG SHOULD DEVELOP MAINLY IN COASTAL
SECTIONS...WITH SOME PATCHY RADIATION FOG ELSEWHERE.

THE FOG AND STRATUS WILL HANG AROUND MON...WITH SOME BREAKS
POSSIBLE ESPECIALLY OVER THE INTERIOR MON AFTN.

NO RAIN IS EXPECTED THRU MON...HOWEVER AREAS OF DZ WILL BE CAPABLE
OF WETTING THE SFC. THE NAM IS THE MOST AGGRESSIVE MODEL WITH THIS
DEVELOPMENT...AND THE MODEL HAS HANDLED THE LLVL MOISTURE BETTER
THAN THE GFS THUS FAR WITH THIS PATTERN.

A WIDE RANGE IN TEMPS CAN BE EXPECTED AGAIN ON MON...WITH HIGHS
NEAR 60 FAR E AND IN THE 70S W. TEMPS IN THE W COULD BE A FEW
DEGREES HIGHER THAN FCST IF THERE IS ENOUGH AFTN CLEARING FOR
BETTER HEATING/DEEPER MIXING.

&&

.SHORT TERM /MONDAY NIGHT/...
HEIGHTS WILL STEADILY FALL MON NGT...AND THE LLJ WILL INCREASE
TO AROUND 50KT PER THE NAM AND GFS. ALTHOUGH THE MAIN SYNOPTIC
FORCING WILL REMAIN W OF THE CWA...SOME SCT-ISOLD SHRA COULD BE
TRIGGERED. AS A RESULT HAVE KEPT POPS BLW 60 BUT INCLUDED COVERAGE
WORDING. FOG AND PERHAPS DZ WILL CONTINUE TO HANG AROUND...WITH
SKIES MAINLY OVC WITH THE MOIST MARINE FLOW. TEMPS SHOULD BE
FAIRLY UNIFORM IN THE 50S DUE TO THE BUILDING LLVL MOISTURE.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
GUIDANCE REMAINS CONSISTENT ON A STRENGTHENING COLD FRONT
APPROACHING ON TUE..AND MOVING ACROSS TUE EVENING. DEEP LAYER S-SW
FLOW AHEAD OF THE FRONT SHOULD TAP NICELY INTO GULF AND ATLANTIC
MOISTURE...WITH PW INCREASING TO NEAR 1.5 INCHES...SO THREAT FOR
SOME HEAVY RAIN CONTINUES...ESPECIALLY WITH A STRENGTHENING LLJ
POKING INTO THE AREA DURING THE DAY ON TUE...AND INTO TUE EVENING
WITH FROPA. RAINFALL WILL ALSO BE ENHANCED IN/NEAR THE HIGHER
ELEVATIONS INLAND VIA OROGRAPHIC ENHANCEMENT. ADVECTION FOG
EXPECTED ESPECIALLY ALONG/NEAR SOUTH FACING COASTLINES AS THE
MOIST AIR MASS TRAVERSES THE COLD ATLANTIC WATERS OVER A LONG
FETCH.

SUSTAINED SOUTHERLY WINDS AHEAD OF THE FRONT SHOULD ALSO INCREASE TO
20-25 KT...AND WITH THE LLJ INCREASING TO 65-70 KT PER 12Z NAM COULD
SEE GUSTS TO 40-45 KT. GIVEN THE STRONG LL INVERSION IN PLACE THESE
SHOULD BE LIMITED TO STRONGER EMBEDDED CELLS IN HEAVY RAIN AND WOULD
BE HANDLED VIA SHORT FUSED PRODUCTS.

THE BETTER CHANCE FOR MORE WIDESPREAD STRONG WINDS WILL COME JUST
AFTER THE COLD FROPA TUE NIGHT AS COLD AIR QUICKLY MOVES IN AND LOW
LEVELS BECOME UNSTABLE...WITH GUSTS 35-45 MPH POSSIBLE. THE COLD AIR
COULD ALSO BRING A BRIEF MIX WITH OR CHANGE TO SNOW LATER TUE
NIGHT...EVEN ALL THE WAY DOWN TO THE COAST.

THE FRONT NOW LOOKS TO PASS FAR ENOUGH SOUTH/EAST TO GO MORE
CONFIDENTLY WITH A DRY FCST FOR WED-FRI AS HIGH PRESSURE BUILDS FROM
THE WEST. CLOUDS SHOULD INCREASE FRI NIGHT AS THE HIGH
WEAKENS/RETREATS EWD...WITH A CHANCE FOR SOME LIGHT RAIN THIS
WEEKEND AS GUIDANCE SHOWS AN AMPLIFYING UPPER TROUGH APPROACHING
FROM THE WEST AND PHASING WITH A WEAKER SRN STREAM TROUGH...WITH
PRIMARY INLAND LOW PRESSURE AND SECONDARY DEVELOPMENT OCCURRING
ALONG THE FRONTAL BOUNDARY STALLED WELL TO THE SOUTH.

TEMPS AFTER COLD FROPA SHOULD BE BELOW AVG WED-THU...WITH HIGHS
MOSTLY IN THE UPPER 40S AND TO LOWER 50S. THU COULD BE ESPECIALLY
RAW OVER ERN LONG ISLAND VIA A PERSISTENT ENE MARITIME FLOW...WITH
HIGHS ONLY ONLY IN THE LOWER/MID 40S. SOME MODERATION MAY TAKE PLACE
THIS WEEKEND...BUT TEMPS OVERALL SHOULD STILL BE A LITTLE BELOW AVG.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE REMAINS OVER THE WESTERN ATLANTIC AS LOW PRESSURE
OVER THE CENTRAL UNITED STATES SLOWLY MOVES NORTH AND EAST THROUGH
MONDAY MORNING.

VFR INTO THIS EVENING...AND THEN FOG/STRATUS WILL DEVELOP TOWARDS
MIDNIGHT TONIGHT. COASTAL AIRPORTS SUCH AS KJFK/KISP/KGON ARE THE
MOST LIKELY AIRPORTS TO OBSERVE THESE LOWER CLOUDS...BUT MODELS
INDICATING SUB-VFR CONDS COULD BE MORE WIDESPREAD. THOUGH CIGS
WILL LIKELY DROP TO IFR...DO NOT FORESEE WIDESPREAD VSBYS IFR OR
LOWER.

TIMING REMAINS UNCERTAIN...BUT BEST CHANCE FOR SUB VFR CONDITIONS IS
AFTER MIDNIGHT. ANY STRATUS SHOULD SCOUR OUT LATER MONDAY MORNING.

SOUTHERLY WINDS WILL DIMINISH TO 8-12 KT...AND THEN INCREASE TO
15-20 KT WITH 20-30 KT GUSTS MONDAY AFTERNOON.

.OUTLOOK FOR 00Z SUNDAY THROUGH FRIDAY...
.MON NIGHT...BECOMING SUB VFR IN SCATTERED SHOWERS/LOW CLOUDS AND
FOG. LLWS POSSIBLE.
.TUE-TUE NIGHT...IFR LIKELY WITH RAIN AND FOG. LLWS POSSIBLE EARLY.
GUSTY NW-N WINDS AFTER COLD FROPA TUE NIGHT.
.WED-FRI...VFR.

&&

.MARINE...
A SCA REMAINS FROM TNGT THRU MON NGT. ELSEWHERE...SLY WINDS WILL
REACH SCA LVLS ON MON INTO MON EVE...AND AN SCA REMAINS
FOR THIS AS WELL. THERE IS THE POTENTIAL FOR AREAS OF DENSE FOG TO
DEVELOP AT TIMES THRU MON NGT.

STRONG SCA CONDS ARE LIKELY TO CONTINUE VIA PERSISTENT/INCREASING
S FLOW AHEAD OF A COLD FRONT TUE INTO TUE EVENING...WITH ADVECTION
FOG LIKELY LIMITING VSBY TO 1 NM OR LESS ESPECIALLY ON THE
OCEAN. MODERATE TO HEAVY RAIN ALSO POSSIBLE...WITH ISOLD STRONG
WIND GUSTS OVER GALE FORCE POSSIBLE IN STRONGER CELLS.
POST-FRONTAL NW GALES ARE HOWEVER MORE LIKELY AFTER FROPA
TUE NIGHT.

SCA CONDS ON ALL WATERS WED MORNING SHOULD RAMP DOWN ON THE
PROTECTED WATERS...BUT AN EXTENDED PD OF HAZARDOUS OCEAN SEAS IS
POSSIBLE INTO FRI VIA COMBO OF LEFTOVER SWELLS AND PERSISTENT E-NE
FLOW BETWEEN INLAND HIGH PRESSURE AND A STALLED FRONTAL ZONE WELL TO
THE SOUTH.

&&

.HYDROLOGY...
QPF OF 1.00 TO 1.75 INCHES...NEARLY ALL RAIN...EXPECTED FROM LATE
MON NIGHT INTO TUE NIGHT...WITH WETTER GUIDANCE STILL SIGNALING
POTENTIAL FOR HIGHER END LOCAL AMTS OF 2-3 INCHES. MOST FLOODING
WILL MOSTLY BE MINOR FLOODING OF URBAN/POOR DRAINAGE AREAS AND
FLASHY SMALL STREAMS.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 10 PM EDT MONDAY FOR ANZ330-
     335-340-345.
     SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ350-353-355.

&&

$$










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