994
FXUS61 KOKX 212113
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
513 PM EDT SAT JUN 21 2025
SYNOPSIS
HIGH PRESSURE WILL BECOME MORE ESTABLISHED THROUGH THE WEEKEND.
A FEW DISTURBANCES WILL PASS THROUGH THIS WEEKEND. WEAK LOW
PRESSURE MOVES SOUTHEAST FROM NOVA SCOTIA INTO WESTERN ATLANTIC
ON MONDAY. STRONG RIDGE OF HIGH PRESSURE STILL BASED SOUTH AND
WEST OF THE REGION ON MONDAY. HIGH PRESSURE REMAINS BASED SOUTH
AND WEST OF THE REGION TUESDAY. A COLD FRONT MOVES NEAR THE
AREA WEDNESDAY AND WEAKENS WITH MULTIPLE WEAK WAVES OF LOW
PRESSURE MOVING ALONG IT FOR THE LATTER HALF OF THE WEEK.
NEAR TERM /UNTIL 6 AM SUNDAY MORNING/
QUIET CONDITIONS CONTINUE THROUGH TONIGHT WITH SOME FAIR WEATHER
CUMULUS CLOUDS THROUGH THIS EVENING. WHILE NO POPS ARE IN THE
FORECAST A FEW CAMS HAVE A POP-UP SHOWER THIS AFTERNOON.
A DEVELOPING SW FLOW THIS AFTERNOON AND TONIGHT WILL ADVECT MOISTURE
BACK INTO THE AREA. THERE IS STILL QUITE BIT OF UNCERTAINTY WITH THE
POSSIBLE DEVELOPMENT OF A CONVECTIVE MCS THAT RIDES OVER THE
NORTHERN PORTION OF THE DEVELOPING RIDGE. SOME CAMS INDICATE THAT
THIS MCS THAT DEVELOPS OVER SOUTHERN CANADA THIS AFTERNOON MAY
QUICKLY TRAVERSE THROUGH PARTS OF THE AREA SOMETIME LATE TONIGHT
INTO SUNDAY MORNING. AT THIS TIME HAVE OPTED NOT TO FORECAST
ANYTHING MORE THAN A SLIGHT CHANCE AS THE POTENTIAL MCS CONTINUES TO
SHOW RAPID WEAKENING AS IT APPROACHES THE AREA. BEST CHANCE TO SEE
ANY SORT OF PRECIPITATION WOULD BE FOR AREAS NORTH, BUT ONCE AGAIN,
CONFIDENCE IN THE OCCURRENCE OF THIS IS MUCH LOWER THAN NORMAL AT
THIS TIME FRAME.
LOWS TONIGHT WILL BE IN THE 70S WITH DEWPOINTS IN THE 60S.
SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/
* EXTREME HEAT WARNING FOR MUCH OF THE REGION FROM SUNDAY
AFTERNOON THROUGH 8 PM TUESDAY INCLUDING NYC.
* HEAT ADVISORY IS NOW IN EFFECT FOR SUNDAY AND AN EXTREME HEAT
WATCH ON MONDAY AND TUESDAY REMAINS, FOR PORTIONS OF LONG
ISLAND AND COASTAL MIDDLESEX AND NEW LONDON COUNTIES.
SUNDAY MORNING, THE DEVELOPMENT OF THE RIDGE WILL BE WELL UNDERWAY
WITH HEIGHTS CONTINUING TO RISE ALOFT AND HIGH PRESSURE
STRENGTHENING TO THE SOUTH. THERE IS THE POTENTIAL OF SOME MORNING
CLOUD COVER OR SHOWERS FROM A DECAYING MCS MOSTLY ACROSS OUR
NORTHERN ZONES, BUT OTHERWISE SKIES WILL BE MOSTLY CLEAR. SUNDAY IS
EXPECTED TO BE THE BEGINNING OF WHAT MAY VERY WELL BE A RECORD
SETTING HEATWAVE FOR SOME LOCATIONS.
SW FLOW WILL CONTINUE TO ALLOW DEW POINTS TO RISE INTO THE UPPER 60S
AND LOWER 70S WITH TEMPERATURES CLIMBING INTO THE 90S FOR MUCH OF
THE AREA. SOME OF THE HOTTEST SPOTS NEAR THE NYC METRO MAY APPROACH
100 DEGREES. HEAT INDEX VALUES WILL BE GENERALLY 100-105 FOR MUCH OF
THE AREA. FOR AREAS CLOSER TO THE COAST, HEAT INDEX VALUES OF 95-100
WILL BE EXPECTED.
LOWS AT NIGHT WILL NOT OFFER MUCH RELIEF AS LOW TEMPERATURES WILL
ONLY BE IN THE 70S WITH MORE URBAN LOCATIONS POSSIBLY NOT DROPPING
BELOW 80.
GIVEN THE EXPECTED EXCESSIVE HEAT, THE EXTREME HEAT WATCH THAT
WAS IN EFFECT FOR NYC HAS BEEN UPGRADED TO AN EXTREME HEAT WARNING
FOR SUNDAY THROUGH TUESDAY. THE HIGHEST HEAT INDEX VALUES WILL
OCCUR EACH AFTERNOON, BUT ESPECIALLY ON MONDAY AND TUESDAY.
LONG TERM /MONDAY THROUGH SATURDAY/
* EXTREME HEAT CONTINUES MONDAY AND TUESDAY FOR PORTIONS OF THE
REGION
* HEAT WAVE POTENTIALLY BREAKS LATER IN THE WEEK (THURSDAY
THROUGH SATURDAY) WITH MORE UNSETTLED WEATHER PATTERN TAKING
SHAPE
STRONG RIDGING WITH HIGH PRESSURE REMAINS DOMINANT FEATURE EARLY
IN THE WEEK WITH THIS RIDGING WEAKENING MID TO LATE WEEK,
ALLOWING FOR MORE DISTURBANCES TO MOVE ACROSS ALONG THE PERIPHERY
OF THIS RIDGE.
REGARDING EXTREME HEAT, THE NEW FORECAST INCORPORATES A BLEND OF
MOS, NBM AND THE PREVIOUS FORECAST FOR THE MAX TEMPERATURE FORECAST
AND DEWPOINT FORECAST MONDAY. USED NBM FOR TEMPERATURES TUESDAY AND
THEREAFTER.
THE MAX TEMPERATURE FORECAST FOR MONDAY USED 40 PERCENT NBM, 40
PERCENT PREVIOUS FORECAST AND 20 PERCENT MOS CONSENSUS. MOS DID
SHIFT SEVERAL DEGREES LOWER COMPARED TO LAST RUN. DID NOT WANT TO
MAKE SIGNIFICANT CHANGES JUST BASED ON SUITE OF MODEL RUNS THAT
BEING 12Z THIS MORNING. 12Z MOS MODEL DATA DID LOWER BY SEVERAL
DEGREES COMPARED TO PREVIOUS RUN AND IN SOME LOCATIONS MORE. THAT IS
WHY MOS CONSENSUS WAS WEIGHED LESS.
ONE SIGNIFICANT TREND MONDAY IS THAT DEWPOINTS RISE. SYNOPTICALLY,
LOW PRESSURE PASSES WELL TO THE EAST OF THE AREA AND WITH HIGH
PRESSURE TO THE SOUTH AND WEST, A MORE SOUTHERLY FLOW WILL BE DRIVEN
INTO THE LOCAL REGION. IF LOW PRESSURE DOES TREND ANY STRONGER OR
CLOSER EAST OF THE AREA OVER THE ATLANTIC, THAT WOULD INVOKE A MORE
SOUTHEAST FLOW AS OPPOSED TO THE SOUTH FLOW WHICH COULD TREND
TEMPERATURES DOWNWARD WITH SUBSEQUENT FORECASTS.
MODELS STILL INDICATE 850MB TEMPERATURES NEAR 21 TO 23 DEGREES C
WITH STRONG RIDGING AT 500MB, WELL ABOVE 590 DM FOR MONDAY.
SUBSIDENCE WILL ALLOW FOR DRY CONDITIONS AND MOSTLY SUNNY SKY
CONDITIONS. SURFACE TEMPERATURES WILL EASILY RISE WITH DIURNAL
HEATING AS A RESULT AND THE SOUTHERLY FLOW WILL PROVIDE MORE
HUMID CONDITIONS. MAX APPARENT TEMPERATURES FORECAST 105 TO 110
ACROSS PORTIONS OF NYC, NE NJ, LOWER HUDSON VALLEY AND PORTIONS
OF SOUTHERN CT FOR MONDAY. EXTREME HEAT WARNING CONTINUES TO
COVER THIS AS WELL AS AREAS THAT ARE CLOSE THE 105 DEGREE HEAT
INDEX MARK.
TUESDAY, 500MB SHOWS A SLIGHT DECREASE IN HEIGHT, BUT STILL
PROMINENT RIDGE REMAINS ESTABLISHED ACROSS THE REGION. 850MB
TEMPERATURES TUESDAY STILL NEAR 22 TO 23 DEGREES C. DAYTIME
TROUGHING APPEARS MORE EVIDENT TUESDAY, GIVING MORE OF A
WESTERLY COMPONENT. PRESSURE GRADIENT IS NOT TOO STRONG SO WINDS
NEAR 5-10 KT SW TO W. MORE DAYTIME MIXING EXPECTED BUT
DEWPOINTS STILL MID 60S TO NEAR 70 FOR THE REGION. MAX APPARENT
TEMPERATURE FORECAST JUST SLIGHTLY LESS THAN THE PREVIOUS DAY.
ACROSS THE EXTREME HEAT WARNING AREA, MOST LOCATIONS ARE AROUND
105 DEGREE HEAT INDEX WITH SOME LOCATIONS SLIGHTLY HIGHER.
OUTSIDE THE EXTREME HEAT WARNING, WE HAVE AN EXTREME HEAT WATCH FOR
NASSAU INTO WESTERN SUFFOLK AS WELL AS SOUTHEAST CT ALONG THE COAST.
105 DEGREE HEAT INDEX VALUES ARE POSSIBLE WITHIN THIS REGION BUT
MOST FORECAST VALUES ARE IN THE MID 90S TO AROUND 100 RANGE.
WEDNESDAY MARKS A TRANSITION TIME PERIOD WHERE THE HEAT WANES
WITH MORE HEIGHT DECREASES AT 500MB WITH 850MB TEMPERATURES MORE
WITHIN THE 18 TO 20 DEGREE C RANGE. MAX APPARENT TEMPERATURE
RANGE WEDNESDAY FORECAST WESTERN SUFFOLK WEST THROUGH NE NJ AND
LOWER HUDSON VALLEY AND MUCH OF SOUTHERN CT, MORE IN THE 95 TO
100 DEGREE C RANGE. THIS FORECAST IS A FEW DAYS AWAY AND THERE
IS UNCERTAINTY OF A FEW DEGREES WITH TEMPERATURE AND DEWPOINTS.
THIS COULD VERY WELL MAKE THE DIFFERENCE WITH HEAT INDICES AS A
RESULT. HEAT INDEX COULD POTENTIALLY GET TO 105 FOR MUCH OF THE
AREA AS PREVIOUS DAYS. SO, HEAT HEADLINES MAY NEED TO GET
EXTENDED INTO WEDNESDAY.
OTHERWISE, LESS RIDGING AND THE APPROACH OF A COLD FRONT WEDNESDAY
WHICH COULD VERY WELL STALL OUT THEREAFTER WILL PRESENT A MORE
UNSETTLED WEATHER PATTERN. MULTIPLE MODEL GUIDANCE SETS
INDICATES A SUBSTANTIAL COOL DOWN THURSDAY THROUGH SATURDAY,
WITH TEMPERATURES ON AVERAGE FOR HIGHS MORE IN THE 80S. CHANCES
FOR SHOWERS AND THUNDERSTORM REAPPEAR IN THE FORECAST.
AVIATION /21Z SATURDAY THROUGH THURSDAY/
VFR WITH HIGH PRESSURE IN CONTROL.
SW-S 5-10 KT EXPECTED THIS AFTERNOON. ALONG THE COAST, EXPECT
THE AFTERNOON SEA BREEZE TO PRODUCE WINDS CLOSER TO 10-15 KT.
WINDS BECOME LIGHT AND VARIABLE TONIGHT. WINDS ON SUNDAY WILL BE
FROM THE SW. CAN NOT RULE OUT AN ISOLATED SHOWER THIS
AFTERNOON/EVENING.
...NY METRO (KEWR/KLGA/KJFK/KTEB) TAF UNCERTAINTY...
S-SE HARBOR BREEZE SHOULD HOLD JUST E OF KEWR THIS AFTERNOON, BUT
MAY MAKE IT IN THERE AND AT KTEB TOWARD 00Z SUNDAY.
OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY
SUNDAY AFTERNOON: VFR. CHANCE OF AN ISOLATED SHOWER OR
THUNDERSTORM IN THE AFTERNOON. WSW-SW WINDS G15-20KT IN THE
AFTERNOON.
MONDAY AND TUESDAY: VFR.
WEDNESDAY: CHANCE OF SHOWERS/TSTMS IN THE AFTERNOON/EVENING MAINLY
FOR KHPN/KSWF.
THURSDAY: CHANCE OF SHOWERS/TSTMS MAINLY IN THE
AFTERNOON/EVENING.
DETAILED INFORMATION, INCLUDING HOURLY TAF WIND COMPONENT FORECASTS,
CAN BE FOUND AT: HTTPS:/WWW.WEATHER.GOV/ZNY/N90
MARINE
BELOW SCA CONDITIONS EXPECTED THROUGH SUNDAY NIGHT WITH SOME
OCCASIONAL 5 FEET SEAS SUNDAY AFTERNOON/EVENING. SUB-SCA
CONDITIONS FORECAST MONDAY THROUGH THURSDAY NIGHT WITH THE
PRESSURE GRADIENT OVERALL NOT BEING STEEP AS LARGE SCALE HIGH
PRESSURE RIDGE IS HOLDING STRONG MUCH OF THE TIME.
HYDROLOGY
THERE ARE NO HYDROLOGIC CONCERNS WITH MAINLY DRY CONDITIONS
PREVAILING THROUGH THE MIDDLE OF NEXT WEEK.
TIDES/COASTAL FLOODING
LOW RISK FOR RIP CURRENTS FOR ALL OCEAN BEACHES WITH A
DIMINISHED SWELL AND LOWER OFFSHORE WAVE HEIGHTS THROUGH EARLY
THIS EVENING.
WITH AN INCREASE IN ONSHORE SWELL (3 TO 4 FT) AND SOUTHERLY
WINDS (SW 10-15 KTS), A MODERATE RISK OF RIP CURRENTS IS
FORECAST FOR ALL OCEAN BEACHES ON SUNDAY.
WINDS LIGHTEN AND BECOME MORE VARIABLE SUNDAY NIGHT INTO EARLY
MONDAY WITH A RESUMPTION OF LIGHT SOUTHERLY FLOW MONDAY
AFTERNOON (5-10 KTS). ONSHORE SWELL DECREASES FOR MONDAY (2 TO 3
FT). THERE IS A LOW RISK OF RIP CURRENTS FORECAST FOR MONDAY
FOR ALL OCEAN BEACHES.
CLIMATE
INCREASING HEAT MAY RESULT IN RECORD HIGH TEMPERATURES SUNDAY
THROUGH TUESDAY.
SUNDAY'S RECORD HIGHS (JUNE 22):
EWR 101 / 1988
BDR 93 / 1949
NYC 98 / 1988
LGA 99 / 1988
JFK 94 / 2012
ISP 94 / 2012
MONDAY'S RECORD HIGHS (JUNE 23):
EWR 99 / 2024
BDR 91 / 2010
NYC 96 / 1888
LGA 95 / 2024 AND PREVIOUS YEARS
JFK 94 / 2010
ISP 91 / 1999
TUESDAY'S RECORD HIGHS (JUNE 24):
EWR 97 / 1966
BDR 94 / 1966
NYC 96 / 1888
LGA 96 / 2013
JFK 97 / 2010
ISP 96 / 1966
OKX WATCHES/WARNINGS/ADVISORIES
CT...AIR QUALITY ALERT FROM 11 AM SUNDAY TO 11 PM EDT MONDAY FOR
CTZ005>012.
EXTREME HEAT WARNING FROM NOON SUNDAY TO 8 PM EDT TUESDAY FOR
CTZ005>010.
HEAT ADVISORY FROM NOON TO 8 PM EDT SUNDAY FOR CTZ011-012.
EXTREME HEAT WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY
EVENING FOR CTZ011-012.
NY...EXTREME HEAT WARNING FROM NOON SUNDAY TO 8 PM EDT TUESDAY FOR
NYZ067>075-176-178.
HEAT ADVISORY FROM NOON TO 8 PM EDT SUNDAY FOR NYZ078-080-177-
179.
EXTREME HEAT WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY
EVENING FOR NYZ078-080-177-179.
AIR QUALITY ALERT FROM 11 AM TO 11 PM EDT SUNDAY FOR
NYZ078>081-177-179.
NJ...EXTREME HEAT WARNING FROM NOON SUNDAY TO 8 PM EDT TUESDAY FOR
NJZ002-004-006-103>108.
AIR QUALITY ALERT FROM 11 AM TO 11 PM EDT MONDAY FOR NJZ002-
004-006-103>108.
AIR QUALITY ALERT FROM 11 AM TO 11 PM EDT SUNDAY FOR NJZ004-
006-103>108.
MARINE...NONE.
SYNOPSIS...20
NEAR TERM...20
SHORT TERM...20
LONG TERM...JM
AVIATION...BC
MARINE...20/JM
HYDROLOGY...20/JM
TIDES/COASTAL FLOODING...
CLIMATE...
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