Area Forecast Discussion
Issued by NWS Upton, NY

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 201955
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
355 PM EDT WED AUG 20 2014

.SYNOPSIS...
HIGH PRESSURE REMAINS CENTERED TO THE NORTH AND EAST OF THE AREA
THROUGH THURSDAY NIGHT. MEANWHILE...WAVES OF LOW PRESSURE ALOFT
MOVE ACROSS THE REGION TONIGHT AND AGAIN THURSDAY INTO THURSDAY
NIGHT. AN UPPER LEVEL DISTURBANCE WILL TRACK THROUGH THE AREA ON
FRIDAY AS HIGH PRESSURE BUILDS DOWN FROM EASTERN CANADA. THIS HIGH
WILL GRADUALLY BUILD DOWN THE EASTERN SEABOARD THROUGH THE MIDDLE
OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS THE UPPER LEVEL LOW CENTERED OVER N MICHIGAN OPENS UP AND SLIDES
TO THE SOUTHEAST...A SHORTWAVE ROTATING AROUND IT WILL INFLUENCE THE
AREA OVERNIGHT. WITH HEIGHT FALLS ALOFT...ESPECIALLY ACROSS NW
ZONES...CHANCES FOR SHOWERS WILL INCREASE TOWARDS MORNING. WITH A
SURFACE HIGH NOSING IN FROM THE NORTHEAST...DRIER AIR WILL BE PRESENT
BENEATH H9 OR SO. HOWEVER...IT APPEARS THERE WILL BE ENOUGH FORCING
FOR SOME PRECIPITATION...PRIMARILY ACROSS THE LOWER HUDSON VALLEY.

TEMPS WILL BE A FEW DEGREES MILDER THAN THE PREVIOUS NIGHT IN MOST
AREAS...AS INCREASING CLOUD COVER REDUCES THE ABILITY FOR
RADIATIONAL COOLING. GENERALLY USED A MAV/MET/ECS BLEND AS THERE WAS
GOOD AGREEMENT.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
THERE WILL BE SOME SHOWERS ONGOING DURING THE FIRST HALF OF THE
DAY...AS A SHORTWAVE SWINGS ACROSS THE AREA. BEST CHANCES WILL AGAIN
BE ACROSS WESTERN AND NORTHERN ZONES...AS RIDGING NOSES IN ACROSS
OUR EASTERN SECTIONS. INCLUDED ISO THUNDER ACROSS THE APPROXIMATE
WESTERN THIRD OF THE AREA...WHERE MODEL FIELDS INDICATE A LITTLE
MORE IN THE WAY OF MUCAPE. ADDITIONALLY...THESE AREAS WILL BE LESS
INFLUENCED BY THE MARITIME AIR BEING ADVECTED ACROSS THE AREA THANKS
TO E/SE ONSHORE FLOW.

DUE TO THE AFOREMENTIONED ONSHORE FLOW AND INCREASED CLOUD
COVER...TEMPS WILL BE COOLER THAN THE PREVIOUS DAY...WITH MANY AREAS
STAYING IN THE 70S / BELOW NORMAL FOR THIS TIME OF YEAR.

AS THE FIRST WAVE DEPARTS TO THE EAST THURSDAY AFTERNOON AND
EVENING...SUBSIDENCE ALOFT AND THE CONTINUED SURFACE RIDGING POKING
IN FROM THE NORTH AND EAST WILL ALLOW MOST PLACES TO BE DRY LATER IN
THE DAY. CHANCES WILL THEN INCREASE AGAIN OVERNIGHT...AS THE UPPER
LOW TO THE NW OPENS AND APPROACHES THE AREA.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
MODELS ARE IN GOOD AGREEMENT THAT THE H5 PATTERN ACROSS NOAM AT THE
START OF THE LONG TERM PERIOD WILL CONSIST OF A STRONG BROAD RIDGE
ACROSS THE SE CONUS WITH A DEEP TROUGH OUT WEST WITH AN UPPER LOW
CUTTING OFF OVER THE PAC NW AND AN OMEGA BLOCK OVER ERN CANADA WITH
A WEAK CUTOFF LOW MOVING THROUGH NEW ENGLAND.

SOME UNCERTAINTY WITH THE SPECIFIC DETAILS AND TIMING OF VORT MAXES
MOVING AROUND THE LEFT SIDE OF THE UPPER LOW ONCE IT SLIDES
OFFSHORE...BUT THE GENERAL TREND APPEARS TO BE DECREASING CHC`S OF
SHOWERS DURING FRI AS DEEP LAYERED RIDGING BUILDS INTO THE NORTHEAST
FROM THE N. MAY NEED TO ADD SLIGHT TO LOW CHC POPS AT TIMES THROUGH
SAT IN SUBSEQUENT FORECAST PACKAGES TO ACCOUNT FOR THESE TIMING
DIFFERENCES. ADDITIONALLY...THE AMOUNT OF CLOUD COVER FOR FRI AND
SAT IS ALSO QUESTIONABLE AS A RESULT.

OTHERWISE...EXPECT DRY AND SEASONABLE CONDS THROUGH THE MIDDLE OF
NEXT WEEK AS THE H5 FLOW AMPLIFIES IN RESPONSE TO THE BLOCKING
PATTERN. SFC HIGH PRES WILL BUILD DOWN THE ERN SEABOARD DURING THIS
TIME WITH AN ELY FLOW EXPECTED AT LEAST INTO MON. THIS WILL
CONTRIBUTE TO BELOW NORMAL TEMPERATURES THOUGHT THIS TIME...BUT AS
HEIGHTS RISE TUE AND WED...TEMPERATURES WILL REBOUND TO NEAR NORMAL
LEVELS.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
VFR AS HIGH PRESSURE REMAINS OVER THE AREA LATE THIS AFTERNOON AND
EVENING. SCT_BKN CU 040-050 NORTH AND WEST OF THE NY METRO OVER THE
HILLIER TERRAIN WILL DISSIPATE BY 01Z.

CONVECTION FROM D.C. NORTH TO CENTRAL PA AND WESTERN NY WILL
WEAKEN THIS EVENING AS IT APPROACHES THE PA/NJ BOARDER TOWARDS
02Z. SCATTERED SHOWERS COULD REACH THE NY METRO TOWARDS MIDNIGHT.
THESE ARE NOT INCLUDED IN TAFS AS THE PROBABILITY OF THIS IS ONLY
30% AT THIS TIME AND THEY ARE NOT EXPECTED TO AFFECT FLIGHT
CATEGORY.

THURSDAY MORNING COULD START OFF WITH SOME CIGS AROUND 030...THESE
SHOULD RISE SLIGHTLY TO AT LEAST 035-040 BY AFTERNOON.

     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: HIGH CONFIDENCE IN WINDS THIS AFTN. SPEED
AVERAGE JUST BELOW 10 KT...THOUGH EXPECT OCNL 10-12 KT DURING
FOR THE LATE AFTN DEPARTURE BANK.

KLGA FCSTER COMMENTS: WIND DIRECTION WILL VARY 20 DEGREES OF THE
FCST MEAN.

KEWR FCSTER COMMENTS: HIGH CONFIDENCE IN WIND DIRECTION BEING
30-40 DEGREES RIGHT OF 130 MAGNETIC THIS AFTERNOON.

KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.

KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.

KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.

.OUTLOOK FOR 18Z THU THROUGH MON...
.THU AFTN-NGT...VFR. SCATTERED TSTMS MAINLY SOUTH AND WEST OF THE NY
METRO.
.FRI-MON...VFR.

&&

.MARINE...
WITH HIGH PRESSURE STILL EXTENDING ACROSS THE WATERS THURSDAY...AND
ONLY STARTING TO LIFT OUT THURSDAY NIGHT...WINDS AND SEAS WILL
REMAIN BELOW SCA CRITERIA DURING THIS TIME. EASTERLY FLOW WILL BE ON
THE INCREASE LATE THURSDAY THOUGH.

WIND GUSTS ARE EXPECTED TO REMAIN BLO SCA LEVELS...ALTHOUGH COULD
COME CLOSE TO 25 KT ON THE OCEAN WATERS LATE FRI/FRI EVE. AN
INCREASING E-NE FLOW WILL RESULT IN BUILDING SEAS ON THE OCEAN WITH
SCA CONDS EXPECTED BETWEEN FRI NIGHT AND SUN NIGHT. THE GRADIENT
RELAXES THEREAFTER WITH SEAS DIMINISHING.

&&

.HYDROLOGY...
A FEW THUNDERSTORMS ARE POSSIBLE ON THURSDAY ACROSS THE LOWER HUDSON
VALLEY AND INTERIOR NE NJ. ANY STORMS WILL HAVE THE POTENTIAL TO
PRODUCE LOCALLY HEAVY RAIN...BUT BASIN AVERAGED TOTALS ARE FORECAST
TO REMAIN LIGHT...AS ANY THUNDERSTORMS SHOULD BE ISOLATED.

NO SIGNIFICANT RAINFALL IS EXPECTED IN THE EXTENDED.

&&

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

&&

$$
SYNOPSIS...24/PICCA
NEAR TERM...PICCA
SHORT TERM...PICCA
LONG TERM...24
AVIATION...TONGUE
MARINE...24/PICCA
HYDROLOGY...24/PICCA








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