Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 040957
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
557 AM EDT MON MAY 4 2015

.SYNOPSIS...
THE REGION WILL REMAIN IN BETWEEN HIGH PRESSURE CENTERED WELL OFF
THE MID ATLANTIC COAST AND A SLOW MOVING COLD FRONT APPROACHING
FROM THE WEST THROUGH TUESDAY MORNING. THIS COLD FRONT WILL THEN
CROSS THE TRI-STATE TUESDAY AFTERNOON AND EVENING. HIGH PRESSURE
THEN BUILDS IN FROM LATE TUESDAY NIGHT THROUGH SATURDAY NIGHT. A
COLD FRONT APPROACHES FROM THE NORTH ON SUNDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MADE MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. THE FORECAST APPEARS ON TRACK.

CURRENTLY MONITORING PATCHY FOG AT KFOK...FOG CHANNEL AND OTHER
NEAR BY OBS SUGGESTS CONTAINED TO THAT LOCATION...SO WILL NOT
REFLECT IN FORECAST AT THIS TIME. WILL UPDATE IF AREA OF FOG
EXPANDS.

THE AXIS OF A DEEP LAYERED RIDGE WILL SLIDE OVER THE AREA THIS
MORNING...THEN TO THE EAST THIS AFTERNOON. SUBSIDENCE WITH THIS
RIDGE WILL KEEP CLOUD COVER AT A MINIMUM. IT WILL ALSO SERVE TO
LIMIT MIXING UNTIL THIS AFTERNOON...WITH THE BEST MIXING
OCCURRING OVER WESTERN PORTIONS OF THE TRI-STATE.

DO EXPECT A SEABREEZE TO DEVELOP THIS AFTERNOON...WITH SOME
GUSTINESS OVER THE TYPICAL AMBROSE JET REGION.

FOR HIGHS TODAY USED A BLEND OF MAV...MET AND ECS GUIDANCE WITH
NAM 2-METER TEMPERATURES WITH A MIX DOWN FROM 1000 HPA NEAR THE
COAST TO 725 HPA WELL INLAND PER BUFKIT SOUNDINGS. HIGHS TODAY
SHOULD RUN 15 TO 20 DEGREES ABOVE NORMAL.

A COMBINATION OF LOW RELATIVE HUMIDITIES AND SOME GUSTY WINDS IN
THE AFTERNOON BRINGS FIRE WEATHER CONCERNS WITH IT. REFER TO THE
FIRE WEATHER SECTION OF THE AFD FOR DETAILS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
ZONAL FLOW WILL PREVAIL AT 500-700 HPA TONIGHT AND
TUESDAY...FOLLOWED BY A WEAK NORTHERN STREAM TROUGH PASSING AT
THESE LEVELS TUESDAY NIGHT. WITH THE COLD FRONT MAINLY ALIGNED
WITH THE ZONAL FLOW...IT WILL MAKE SLOW PROGRESS INTO THE
REGION...SO HAVE SLOWED TIMING OF PRECIPITATION ACCORDINGLY.
SLIGHT CHANCE POPS ARE CONFINED TO FAR NW ZONES LATE TONIGHT AS A
RESULT.

MODELS STILL SUGGEST THAT WITH BEST FORCING GOING TO THE N...THAT
ANY PRECIPITATION COULD BREAK UP AS IT MOVES INTO THE AREA ON
TUESDAY...FOR THIS REASON HAVE KEPT POPS IN THE CHANCE
CATEGORY...BUT DID CHANGE TO AREAL COVERAGE WORDING IN THE
AFTERNOON. SHOWALTER INDICES IN THE AFTERNOON/EARLY EVENING ARE
FORECAST TO BE AROUND ZERO ACROSS THE CWA...SO ALSO HAVE A SLIGHT
CHANCE OF THUNDER IN THE AFTERNOON AND EARLY EVENING AS WELL.
SINCE ANY THUNDERSTORMS WILL MOST LIKELY BE ELEVATED IN
NATURE...DO NOT EXPECT ANY ISSUES WITH WIND OR HAIL.

HOWEVER...IF THE NAM IS CORRECT AND DO ACHIEVE SEVERAL HUNDRED
J/KG OF CAPE IN THE LATE AFTERNOON ACROSS N/W INTERIOR ZONES THEN
COULD SEE A FEW STRONG STORMS...AND AN ISOLATED SEVERE STORM COULD
NOT BE 100 PERCENT RULED OUT IF THE NAM IS CORRECT.

THE NAM BEING CORRECT IS PREDICATED ON THERE BEING SOME EXTENSIVE
BREAKS IN THE CLOUDS TUESDAY AFTERNOON. GIVEN SLOWER TIMING OF THE
FRONT...DID RAISE HIGHS...BUT NOT AS WARM AS THE NAM WOULD
SUGGEST. APPEARS LOW LEVELS SHOULD BE TOO MOIST TO SUPPORT
EXTENSIVE BREAKS IN THE CLOUDS AT THIS TIME.

BASED ON SLOWER FRONTAL TIMING...HAVE CONTINUED CHANCE POPS INTO
THE EVENING...THEN TAPER OFF FROM NW TO SE THROUGH THE NIGHT.

FOR LOWS TONIGHT...USED A BLEND OF MAV/MET/ECS GUIDANCE WITH NAM
2-METER TEMPERATURES. LOWS SHOULD BE AROUND 10 DEGREES ABOVE
NORMAL.

FOR HIGHS ON TUESDAY USED A BLEND OF ECS/MAV/MET GUIDANCE
WITH NAM 2-METER TEMPERATURES AND A MIX DOWN FROM 825-800 HPA PER
BUFKIT SOUNDINGS. NOTING THE 10 DEGREE TEMPERATURE SPREAD BETWEEN
THE NAM BASED TEMPERATURES AND NON-NAM TEMPERATURES THIS BLEND
ACCOUNTS FOR THE SLOWER FRONTAL MOTION BUT DOES NOT ALLOW FOR
EXTENSIVE BREAKS IN THE CLOUDS...CONSISTENT WITH EARLIER
REASONING. HIGHS SHOULD BE AROUND 10-15 DEGREES ABOVE NORMAL.

A BLEND OF NAM 2-METER TEMPERATURES AND ECS/MET/MAV GUIDANCE WAS
USED FOR LOWS TUESDAY NIGHT...WITH VALUES FORECAST TO BE 5-10
DEGREES ABOVE NORMAL.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE COLD FRONT CONTINUES TO MOVE SOUTH AND EAST OF THE AREA
WEDNESDAY MORNING. MUCH OF THE REGION WILL BE DRY AFTER 12Z
WEDNESDAY...WITH ONLY A SLIGHT CHANCE FOR A SHOWER ACROSS
SOUTHERNMOST ZONES. CLEARING SKY CONDITIONS FROM NORTH TO SOUTH ARE
FORECAST FROM LATE MORNING THROUGH THE REMAINDER OF THE DAY AS HIGH
PRESSURE BUILDS INTO THE AREA.

THURSDAY THROUGH SUNDAY...DEEP UPPER LEVEL RIDGING TAKES HOLD OF THE
LARGE SCALE PATTERN SETTING THE STAGE FOR A PERIOD OF MAINLY DRY
WEATHER AND ABOVE NORMAL TEMPERATURES. MODELS INDICATE POTENTIAL FOR
A COLD FRONT TO SINK SOUTH TOWARDS THE AREA LATE SATURDAY THROUGH
SUNDAY. HAVE KEPT SATURDAY DRY...BUT WITH THE FRONT IN CLOSER
PROXIMITY ON SUNDAY...HAVE DECIDED TO CARRY SLIGHT CHANCE POPS FOR
THE ENTIRE AREA.

FOR TEMPERATURES...HIGHS IN THE LOWER AND MIDDLE 70S FORECAST FOR
WEDNESDAY THROUGH FRIDAY...COOLEST NEAR THE COAST. TEMPERATURES WARM
SATURDAY INTO THE UPPER 70S AND LOWER 80S FROM THE CITY NORTH AND
WEST...WITH LOWER TO MIDDLE 70S NEAR THE COAST. SLIGHTLY COOLER
CONDITIONS ON SUNDAY THAN SATURDAY WITH A BIT MORE CLOUD COVER AND
FRONT IN THE VICINITY. LOW TEMPERATURES WEDNESDAY NIGHT FALL INTO
THE UPPER 40S AND LOWER 50S. LOWS THEN MODERATE THURSDAY NIGHT INTO
THE LOWER 50S AND THEN EVEN MILDER FRIDAY NIGHT AND SATURDAY NIGHT
INTO THE MIDDLE AND UPPER 50S.

&&

.AVIATION /10Z MONDAY THROUGH FRIDAY/...
VFR THROUGH THIS EVENING AS HIGH PRESSURE REMAINS JUST OFF THE
MID ATLANTIC COAST. A COLD FRONT APPROACHES FROM THE NW LATE
TONIGHT.

LGT AND VRB WINDS EARLY THIS MORNING...BECOMING SSW WINDS AND
INCREASING WITH SPEEDS GENERALLY 10-15KT AFT 16Z AS PRES GRADIENT
TIGHTENS. ELSEWHERE...FRQ GUSTS BETWEEN 18-22 KT SHOULD PREVAIL
AFT 17Z...DIMINISHING IN THE EVE. KGON MAY NOT GUST AT ALL DUE TO
LIMITED MIXING.

     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)

KJFK FCSTER COMMENTS: ANTICIPATING AMBROSE JET AFT 20Z WITH
SUSTAINED WINDS AROUND 20KT. GUSTS UP TO 25 KT ARE POSSIBLE
BETWEEN 20Z AND 02Z...BUT LOW CONFIDENCE.

KLGA FCSTER COMMENTS: PK GUSTS OF 25 KT POSSIBLE BETWEEN 20Z AND
02Z.

KEWR FCSTER COMMENTS: PK GUSTS OF 25 KT POSSIBLE BETWEEN 20Z AND
00Z.

THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.

KTEB FCSTER COMMENTS: GUSTS COULD BE A FEW KT HIGHER THAN
FORECAST.

KHPN FCSTER COMMENTS: GUSTS COULD BE A FEW KT HIGHER THAN
FORECAST.

KISP FCSTER COMMENTS: GUSTS COULD BE A FEW KT HIGHER THAN
FORECAST.

.OUTLOOK FOR 06Z TUE THROUGH FRI...
.TONIGHT...VFR.
.TUE-WED MORNING...SLOW COLD FROPA. MVFR OR LOWER CONDS POSSIBLE
WITH ANY SHOWERS. LOW CHANCE FOR TSTMS TUE AFTERNOON/EVENING.
.WED AFTERNOON-FRI...VFR.

&&

.MARINE...
MADE MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. THE FORECAST APPEARS ON TRACK.

FOR NOW EXPECT WIND GUSTS TO REMAIN JUST BELOW SCA LEVELS THIS
AFTERNOON/EVENING AS COOL WATERS SHOULD PROMOTE SUFFICIENT OF AN
INVERSION TO LIMIT GUSTS TO MAINLY AROUND 20 KT...WITH MAYBE AN
OCCASIONAL GUST TO AROUND 25 KT NEAR SHORE.

THESE WINDS COUPLED WITH A PERSISTENT SE SWELL COULD BRING SEAS
TO AROUND 5 FT ON THE COASTAL OCEAN WATERS TONIGHT.

WINDS THEN DIMINISH TO 10 KT OR LESS OVER ALL WATERS BY TUESDAY
AFTERNOON AND REMAIN SO THROUGH AT LEAST FRIDAY MORNING. EVEN WITH
A DEVELOPING RETURN FLOW LATER ON FRIDAY...STILL EXPECT SUB-SMALL
CRAFT CONDITIONS THEN AS WELL.

&&

.FIRE WEATHER...
HAVE THE HIGHEST CONFIDENCE IN FREQUENT GUSTS TO GREATER THAN 25
MPH...COUPLED WITH RELATIVE HUMIDITIES FORECAST GENERALLY UNDER 30
PERCENT...IS OVER NE NJ/NYC/NASSAU COUNTY AND THE LOWER HUDSON
VALLEY THIS AFTERNOON. NOTING THAT THE 950 HPA JET PEAKS AT AROUND
21Z OVER THIS AREA...AND HAVE THE BEST MIXING THEN...HAVE ISSUED A
RED FLAG WARNING FOR THIS AREA FROM 17-23Z TODAY.

ELSEWHERE...WHILE OCCASIONAL GUSTS GREATER THAN 25 MPH ARE
POSSIBLE OVER S CT AND SUFFOLK COUNTY...AT THIS TIME DO NOT HAVE
CONFIDENCE THAT THEY WILL BE FREQUENT. ALSO...ONSHORE FLOW COULD
KEEP RELATIVE HUMIDITIES JUST OVER 30 PERCENT. SO WILL ADDRESS
RISK OF FIRE SPREAD HERE WITH A SPECIAL WEATHER STATEMENT.

&&

.HYDROLOGY...
GENERALLY EXPECT FROM 1/10 TO 1/4 INCH OF BASIN AVERAGE RAINFALL
TUESDAY AND TUESDAY NIGHT FROM ANY SHRA/ISOLD TSTMS WHICH DOES
OCCUR. HOWEVER CANNOT COMPLETELY RULE OUT LOCALLY HEAVY RAINFALL
IN ANY STRONGER CONVECTION. IF THIS DOES OCCUR OVER AN AREA...THEN
LOCALIZED MINOR FLOODING OF URBAN AND POOR DRAINAGE AREAS WOULD BE
POSSIBLE.

MAINLY DRY CONDITIONS ARE EXPECTED WEDNESDAY THROUGH THE WEEKEND.

&&

.EQUIPMENT...
KOKX RADAR REMAINS OUT OF SERVICE. REPAIRS WILL BEGIN LATER TODAY ONCE
PARTS ARRIVE. UPDATED ESTIMATE FOR COMPLETION OF REPAIR IS THIS EVENING.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM EDT THIS
     EVENING FOR NYZ067>075-176>179.
NJ...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM EDT THIS
     EVENING FOR NJZ002-004-006-103>108.
MARINE...NONE.

&&

$$
SYNOPSIS...MALOIT/DS
NEAR TERM...MALOIT
SHORT TERM...MALOIT
LONG TERM...DS
AVIATION...24
MARINE...MALOIT/DS
FIRE WEATHER...
HYDROLOGY...MALOIT/DS
EQUIPMENT...


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