Area Forecast Discussion
Issued by NWS Upton, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KOKX 180809
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
409 AM EDT SAT APR 18 2015

.SYNOPSIS...
A COLD FRONT APPROACHES TODAY AND MOVES ACROSS THE AREA THROUGH
THIS EVENING. HIGH PRESSURE BUILDS OVER THE AREA SUNDAY AND MOVES
OFFSHORE LATE IN THE DAY AS A FRONTAL SYSTEMS APPROACHES FROM THE
SOUTHWEST. A FRONTAL WAVE PASSES OVER OR RIGHT BY THE AREA MONDAY
NIGHT...FOLLOWED BY A COLD FRONTAL PASSAGE LATE AT NIGHT INTO
TUESDAY MORNING. A SERIES OF WEAK COLD FRONTS OR TROUGHS WILL MOVE
THROUGH DURING THE MIDWEEK PERIOD FOLLOWED BY HIGH PRESSURE AT THE
END OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOME PATCHY FOG WILL LINGER ACROSS PORTIONS OF THE INTERIOR AND
ACROSS EASTERN LONG ISLAND. THAT FOG SHOULD DISSIPATE AND BURN OFF
SHORTLY AFTER SUNRISE.

OTHERWISE...THE WARMEST DAY OF THE YEAR ON TAP WITH THE
COMBINATION OF MOSTLY SUNNY SKIES...DEEP MIXING...850 MB TEMPS
RANGING FROM +8C TO +10C...AND DOWNSLOPING WESTERLY FLOW. HIGHS
TODAY WILL RANGE FROM THE UPPER 70S TO AROUND 80 FOR NYC AND MOST
AREAS ALONG AND WEST OF THE HUDSON RIVER...AND IN THE MID 70S FOR
INTERIOR PORTIONS OF SOUTHERN CT AND THE REST OF THE LOWER HUDSON
VALLEY. FOR LONG ISLAND...COASTAL CT...AND COASTAL PORTIONS OF
NYC...HIGHS WILL TOP OFF IN THE LOW 70S.

A COLD FRONT APPROACHES LATER IN THE DAY...ALLOWING FOR WINDS TO
SHIFT FROM A SW FLOW TO MORE OF A WESTERLY FLOW.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
COLD FRONT MOVES ACROSS THE REGION THIS EVENING. WINDS MAY INCREASE
TO 15-20 MPH WITH 20-30 MPH WITH ITS PASSAGE...BUT WINDS DIMINISH
AS THE EVENING PROGRESSES...AND WINDS WILL SHIFT TO THE NORTH AT
5-10 MPH BY MIDNIGHT TONIGHT.

THE FRONT SHOULD COME THROUGH DRY...WITH THE EXCEPTION OF SOME
MID-LEVEL CLOUDS WITH ITS PASSAGE.

HIGH PRES OVER EASTERN CANADA WILL DROP INTO THE GULF OF MAINE
WITH THE CENTER OF THE HIGH JUST EAST OF CAPE COD ON SUNDAY. AS A
RESULT...WINDS WILL SHIFT TO THE SOUTHEAST...USHERING A MUCH
COOLER AND MORE SEASONAL AIRMASS INTO THE REGION. HIGHS ON SUNDAY
WILL TOP OFF IN THE MID 50S TO LOW 60S...EXCEPT FOR LONG ISLAND
AND COASTAL CT...WHERE HIGHS WILL ONLY BE IN THE LOW 50S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AN AMPLIFYING FULL LATITUDE TROF WILL LIFT NORTH AND EAST ACROSS
THE GREAT LAKES AND INTO THE NE SUN NIGHT INTO TUE. THIS WILL
RESULT IN AN APPROACHING FRONTAL SYSTEM THAT WILL HAVE BOTH
ATLANTIC AND GULF MOISTURE TO WORK WITH. PWAT VALUES WILL BE ON
THE ORDER OF 2SD ABOVE NORMAL. THE 00Z GLOBAL MODELS HAVE SPED UP
THE TIMING OF THIS SYSTEM BY A LITTLE...BUT STILL SOME DIFFERENCES
REGARDING PLACEMENT OF HIGHER RAIN AMOUNTS.

A FRONTAL WAVE IS FORECAST TO PASS OVER OR NEARBY JUST THE AREA
MON NIGHT...IN ESSENCE KEEPING THE AREA NEARBY DECENT LIFT. LIFT
WILL BE ENHANCED...ESPECIALLY OVER THE EASTERN HALF OF THE
CWA...BY FRONTOGENETIC FORCING AND A 50-60 KT SE LLJ LATE SUN
NIGHT INTO EARLY MON MORNING. THINKING IS THAT EASTERN ZONES WILL
PROBABLY END UP WITH HIGHER RAIN AMOUNTS IN GENERAL. INSTABILITY
ALOFT COULD ALSO RESULT IN SOME ISOLATED ELEVATED THUNDER MON
NIGHT...WHICH WOULD ADD TO THE VARIABILITY AND SOME UNCERTAINTY
WITH THE HIGHEST RAIN AMOUNTS FOR THE TRI STATE AREA. RAINFALL
AMOUNTS OF 1 TO 1.5 INCHES ARE FORECAST...WITH THE HIGHEST AMOUNTS
OVER LONG ISLAND AND CT. UP TO 2 INCHES LOCALLY IS STILL POSSIBLE.
THE SE FLOW PROBABLY ENHANCES OROGRAPHIC LIFT...SO FORECAST
AMOUNTS NW OF THE CITY COULD BE A LITTLE TOO LOW. SO IN
GENERAL...RAIN BECOMES LIKELY LATE SUNDAY NIGHT FOR MOST
SPOTS...WITH MODERATE TO POTENTIALLY BRIEFLY HEAVY RAIN MONDAY
MORNING. MID LEVELS DRY OUT MONDAY AFTERNOON...SO LIGHT RAINFALL
OR POSSIBLY EVEN DRIZZLE WOULD BE EXPECTED BY LATE IN THE DAY.
LIGHT RAIN REMAINS LIKELY MONDAY NIGHT AS A WEAK LOW PRESSURE WAVE
CENTER MOVES THROUGH. SOME FOG DEVELOPMENT EXPECTED MON NIGHT AS
WELL WITH WINDS BECOMING LIGHTER AND PLENTY OF MOISTURE AROUND.

GUSTS UP TO 25 TO 30 MPH WILL POSSIBLE AT THE SFC ON MON...BUT
TEMP PROFILES WILL BE INVERTED LIMITING ANY STRONGER WINDS FROM
COMING DOWN.

CONDITIONS DRY OUT TUE INTO WED WITH A SERIES OF WEAK FRONTS
AND/OR TROUGHS MOVING ACROSS THE REGION. THESE WILL REINFORCE A
SEASONABLE AIRMASS. HIGH PRESSURE THEN FOLLOWS FOR THE END OF THE
WEEK. UPPER AIR PATTERN WILL BE DOMINATED BY A BROAD...FLAT TROUGH
EAST OF THE MS RIVER VALLEY.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE FOR TODAY WITH A COLD FRONT PASSING THROUGH THIS
EVENING.

VFR THRU THE TAF PERIOD. LIGHT AND VARIABLE WINDS BCMG MOSTLY
W...EXCEPT SW SEA BREEZES FOR KJFK/KISP/KBDR/KGON. KJFK PROBABLY
SHIFTS S LATE AFTN. GUSTS 20-25 PRIMARILY IN THE AFTERNOON AND
EVENING HOURS. WINDS SHIFT NW BY MIDNIGHT AND BECOME LESS GUSTY
OVERNIGHT.

.OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...
.SAT NGT...VFR WITH DECREASING WINDS.
.SUN...VFR. SFC WND LIGHT NE BECOMING SE 10KT IN THE AFTN. LLWS
LATE.
.MON...MVFR BECOMING IFR. LLWS EARLY. INCREASING ESE SFC WND.
G30KT IN AFTN.
.TUE...MVFR BECOMING VFR. G20-25KT.
.WED...VFR BECOMING SUB VFR BY THE AFTN.

&&

.MARINE...
A COLD FRONT APPROACHES THE WATERS LATER THIS AFTERNOON AND MOVES
ACROSS THIS EVENING. GENERALLY SUB-SCA CONDS...BUT A FEW NEARSHORE
GUSTS TO 25 KT ARE POSSIBLE THIS AFTERNOON.

HIGH PRESSURE BUILDS EAST OF THE WATERS LATE SUN AFT WITH AN
APPROACHING FRONTAL SYSTEM FROM THE WEST. THIS WILL RESULT IN A
STRENGTHENING SE FLOW SUN NIGHT INTO MON WITH SCA CONDITIONS
LIKELY ACROSS ALL WATERS. SEAS WILL BUILD TO 7 TO 10 FT ON
MON...THEN WILL BE SLOW TO SUBSIDE MON NIGHT INTO TUE. SUB-SCA
CONDITIONS ARE EXPECTED ACROSS THE REMAINING WATERS LATE MON NIGHT
INTO WED.

&&

.FIRE WEATHER...
DRY WEATHER...MINIMUM RH 20-30 PERCENT...AND WINDS GUSTING TO
25-30 MPH WILL LEAD TO ELEVATED POTENTIAL FOR FIRE GROWTH/SPREAD
THIS AFTERNOON AND EARLY EVENING. SEVERAL WIND SHIFTS ARE
EXPECTED THROUGH THE DAY...CREATING AN ADDITIONAL HAZARD WITH ANY
ONGOING FIRES. INITIALLY NORTHWEST WINDS WILL SHIFT TO WEST-
SOUTHWEST THEN SOUTHWEST THROUGH THE AFTERNOON...BEFORE RAPIDLY
TURNING NORTHWEST AGAIN AROUND 6-7 PM WITH THE APPROACH/PASSAGE OF
ANOTHER COLD FRONT. GUSTS MAY BRIEFLY STRENGTHEN AFTER THE COLD
FRONTAL PASSAGE. THE FIRE WEATHER WATCH HAS BEEN UPGRADED TO A
RED FLAG WARNING...AND IS IN EFFECT FROM 12 PM TO 8 PM GIVEN
EXPECTED WEATHER CONDITIONS.

&&

.HYDROLOGY...
THERE IS THE POTENTIAL FOR SIGNIFICANT RAINFALL WITH
AN APPROACHING FRONTAL SYSTEM MONDAY INTO MONDAY NIGHT. STORM TOTAL
RAINFALL WITH THIS SYSTEM WILL BE FROM 1 TO 1.5 INCHES...WITH THE
HIGHEST AMOUNTS GENERALLY OVER LONG ISLAND AND CT. LOCALIZED HIGHER
AMOUNTS WILL BE POSSIBLE.

FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB SITE.

&&

.TIDES/COASTAL FLOODING...

A PROLONGED PERIOD OF SE FLOW LATE SUN NIGHT INTO MON EVE WILL
LIKELY RESULT IN WIDESPREAD MINOR COASTAL FLOODING. ASTRONOMICAL
HIGH TIDES WILL BE RUNNING HIGH FOLLOWING A NEW MOON ON SAT. IN SOME
CASES...DEPARTURES OF ONLY HALF A FOOT ABOVE NORMAL ARE NEEDED.
STORM SURGE IS LIKELY TO PRODUCE WATERS LEVELS 1 TO 1 1/2 FT ABOVE
NORMAL.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...RED FLAG WARNING FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
     CTZ005>012.
NY...RED FLAG WARNING FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
     NYZ067>075-078>081-176>179.
NJ...RED FLAG WARNING FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
     NJZ002-004-006-103>108.
MARINE...NONE.

&&

$$
SYNOPSIS...JC/MPS
NEAR TERM...MPS
SHORT TERM...MPS
LONG TERM...JC
AVIATION...JC
MARINE...JC/MPS
FIRE WEATHER...MPS
HYDROLOGY...JC/MPS
EQUIPMENT...


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.