Area Forecast Discussion Issued by NWS Upton, NY
000
FXUS61 KOKX 181144
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
744 AM EDT TUE JUN 18 2013
.SYNOPSIS...
A COLD FRONT SLOWLY PUSHES SOUTH THROUGH THE TRI STATE AREA TODAY
THROUGH TONIGHT. HIGH PRESSURE BUILDS IN BEHIND THE FRONT THROUGH
THE END OF THE WEEK. A WARM FRONT MAY PASS THROUGH THE REGION
SUNDAY OR MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A WEAK SURFACE TROUGH LIES OVER THE REGION THIS MORNING. THE
SURFACE TROUGH AND APPROACHING VORT FROM THE DELMARVA COULD ACT
AS A FOCUS FOR SHOWERS AND TSTMS THIS MORNING. TOUGH TO PICK OUT
THE EXACT LOCATION OF THIS WEAK BOUNDARY...BUT WILL HAVE TO BE
WATCHED AS A FOCUS FOR CONVECTIVE INITIATION THIS MORNING. IF
CONVECTION DOES FIRE...BASED ON STEERING FLOW WOULD HAVE TO WATCH
FOR THREAT OF TRAINING STORMS AND ASSOCIATED FLOODING ISSUES.
THE REST OF THE AREA WILL HAVE THEIR CHANCES MAINLY DURING THE
AFTERNOON AS A COLD FRONT MOVES THROUGH AND HAS ADDITIONAL LIFT
COURTESY OF A MID LEVEL SHORTWAVE. PERHAPS THERE WILL ALSO BE
SOME LIFT FROM BEING NEAR THE RIGHT ENTRANCE REGION OF AN UPPER
LEVEL JET STREAK.
CAPE VALUES PROBABLY NOT AS HIGH AND MID LEVEL LAPSE RATES NOT AS
STEEP AS THEY WERE YESTERDAY. BUT WITH CAPES AWAY FROM THE COAST
STILL IN THE RANGE OF 1000-1500 J/KG COMBINED WITH A BULK SHEAR OF
30-40KT...THERE IS A CHANCE OF STRONG TO POSSIBLY SEVERE TSTMS.
MAV/NAM MOS BLEND WITH A FEW SLIGHT LOCAL ADJUSTMENTS WAS USED FOR
HIGH TEMPS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
THE COLD FRONT CONTINUES TO DRIFT SOUTH...MOVING COMPLETELY OFFSHORE
PROBABLY DURING THE EVENING HOURS. STILL ENOUGH LIFT...CAPE AND
SHEAR FOR STRONG TO POSSIBLY SEVERE TSTMS. RAIN CHANCES THEN
DIMINISH OVERNIGHT WITH THE FRONT OFFSHORE AND HIGH PRESSURE
BUILDING IN BEHIND IT.
LOOKS LIKE THE FRONT SHOULD BE JUST FAR ENOUGH OFFSHORE BY DAYBREAK
ON WEDNESDAY TO KEEP SHOWER CHANCES OUT OF THE FORECAST. A TROUGH
AXIS ALOFT AND ACCOMPANYING SHORTWAVE SHIFTS IN DURING THE
AFTERNOON...BUT IT LOOKS LIKE MOISTURE WILL BE DEEP ENOUGH ONLY FOR
SOME CLOUD BUILDUP IN SPOTS. IT SHOULD FEEL LESS MUGGY WITH DEW
POINTS IN THE 50S AND HIGHS MOSTLY 75-80.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MODELS IN DECENT AGREEMENT WITH MEAN TROUGHING CONTINUING OVER THE
NORTHEAST THROUGH THE END OF THE WEEK...WITH CANADIAN HIGH PRESSURE
GRADUALLY BUILDING INTO THE REGION AND IN CONTROL THROUGH SATURDAY.
THIS WILL RESULT IN FAIR AND SEASONABLE WARM CONDITIONS THROUGH THE
PERIOD. WEAK PIECES OF SHORTWAVE ENERGY ROUNDING THE BASE OF THE
TROUGH COULD SET OFF ISOLATED PULSE SHRA/TSRA ACTIVITY FRI AND
SAT AFT/EVE...PARTICULARLY OFF THE NW HIGHER ELEVATIONS.
HEIGHTS APPEAR TO BUILD THIS WEEKEND INTO EARLY NEXT WEEK...WITH A
TREND TOWARDS MORE SUMMER LIKE WEATHER. THIS WOULD ALSO BRING
POTENTIAL FOR MCS ACTIVITY AS A WARM FRONT WORKS INTO THE VICINITY
OF THE REGION AND THE AREA LIES ON THE SOUTHERN EDGE OF THE
WESTERLIES.
&&
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
A STATIONARY FRONT WILL REMAIN OVER THE TRI-STATE THROUGH
THIS AFTERNOON...THEN PUSH TO THE SOUTH BY EARLY THIS EVENING. A
COASTAL LOW MOVES OFF THE MID ATLANTIC COAST LATE THIS
EVENING...THEN PASSES SE OF LONG ISLAND OVERNIGHT
VFR AT MOST LOCATIONS THROUGH THE MORNING HOURS. COULD SEE SOME
MVFR HZ AT NORTHERN TERMINALS 10-16Z TIME FRAME...PATCHY MVFR FOG
AT KJFK THROUGH 14Z...AND ISOLATED IFR OR LOWER
CEILINGS/VISIBILITIES AT CENTRAL/EASTERN LONG ISLAND TERMINALS
THROUGH 14Z.
HAVE A TEMPO FOR -TSRA THIS AFTERNOON - SPECIFYING A 4 HOUR WINDOW
WHERE IT APPEARS MOST LIKELY THERE WILL BE CONVECTION AT THIS
TIME. STILL SOME UNCERTAINTY AS TO HOW ORGANIZED/WIDESPREAD
THUNDER WILL BE - SO START TIME IS SOMEWHAT UNCERTAIN. WOULD NOT
BE SURPRISED IF THERE WERE A FEW CELLS THAT DEVELOPED OUT AHEAD OF
THE MAIN CONVECTIVE BAND. HAVE THE POTENTIAL FOR STRONG TO
POSSIBLY SEVERE STORMS IF THEY FORM...SO HAVE GUSTS UP TO 40KT IN
THE TEMPO.
STORMS SHOULD BE GONE BY AROUND 23-03Z FROM W TO E...THEN RESIDUAL
LOW LEVEL MOISTURE SHOULD LEAVE MVFR/POSSIBLY IFR CEILINGS/FOG
THIS EVENING. CONFIDENCE IN IFR IS NOT HIGH ENOUGH...EXCEPT AT
KISP AND KGON TO REFLECT IN TAFS AT THIS TIME.
LIGHT AND VARIABLE WINDS ALL DAY AT NORTHERN TERMINALS.
ELSEWHERE...EXCEPT AT KLGA WHERE NE SOUND BREEZE ALREADY IN PLACE
LIGHT AND VARIABLE WINDS THROUGH EARLY AFTERNOON. WINDS BECOME SE-S
UNDER 10 KT AT CT/NYC METRO/LONG ISLAND TERMINALS EARLY-MID
AFTERNOON...THEN BECOME LIGHT AND VARIABLE AGAIN JUST AHEAD OF
THE CONVECTION AT ALL EXCEPT KGON/KISP/KJFK...WHERE THE WINDS
BECOME LIGHT AND VARIABLE POST CONVECTION. AFTER MIDNIGHT WINDS
BECOME NNE- NE AT 5-10KT...THEN INCREASE LATE OVERNIGHT TO AROUND
10KT WITH GUSTS 15-20KT AT ALL BUT KSWF.
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: MODERATE CONFIDENCE ON END TIME OF MVFR
THIS MORNING...COULD BE OFF +/- 2 HOURS. LOW CONFIDENCE IN EXACT
END TIME OF LIGHT AND VARIABLE WINDS...COULD BE OFF +/- 2-3 HOURS.
LOW CONFIDENCE ON START/END TIME OF ANY -TSRA.
KLGA FCSTER COMMENTS: LOW CONFIDENCE IN EXACT END TIME OF NE
WINDS...COULD BE OFF +/- 2-3 HOURS. LOW CONFIDENCE ON START/END
TIME OF ANY -TSRA.
KEWR FCSTER COMMENTS: LOW CONFIDENCE IN EXACT END TIME OF LIGHT
AND VARIABLE WINDS...COULD BE OFF +/- 2-3 HOURS. LOW CONFIDENCE ON
START/END TIME OF ANY -TSRA.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: LOW CONFIDENCE IN EXACT END TIME OF LIGHT
AND VARIABLE WINDS...COULD BE OFF +/- 2-3 HOURS. LOW CONFIDENCE ON
START/END TIME OF ANY -TSRA.
KHPN FCSTER COMMENTS: LOW CONFIDENCE IN EXACT END TIME OF LIGHT
AND VARIABLE WINDS...COULD BE OFF +/- 2-3 HOURS. LOW CONFIDENCE ON
START/END TIME OF ANY -TSRA. LOW-MODERATE CHANCE OF HAZE THIS MORNING.
KISP FCSTER COMMENTS: MODERATE CONFIDENCE ON END TIME OF IFR THIS
MORNING...COULD BE OFF +/- 2 HOURS. LOW CONFIDENCE IN EXACT END
TIME OF LIGHT AND VARIABLE WINDS...COULD BE OFF +/- 2-3 HOURS. LOW
CONFIDENCE ON START/END TIME OF ANY -TSRA.
.OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY...
.WEDNESDAY MORNING...VFR. NE WINDS G15-20KT POSSIBLE.
.WEDNESDAY AFTERNOON-SATURDAY...VFR.
&&
.MARINE...
TRANQUIL CONDITIONS ON ALL WATERS WITH WINDS AT 10 KT OR LESS
TODAY THROUGH TONIGHT. WINDS PICK UP ON WEDNESDAY AS HIGH PRESSURE
BUILDS IN BEHIND A DEPARTING COLD FRONT. WINDS ON THE OCEAN COULD
GUST TO JUST BELOW SMALL CRAFT ADVISORY CRITERIA...BUT THIS WOULD
BE FOR ONLY A RELATIVELY SHORT PERIOD OF TIME. WINDS SHOULD
SUBSIDE A LITTLE BY THE END OF THE DAY.
MAINLY SUB SCA CONDITIONS ARE EXPECTED FOR THE LATE WEEK INTO
SATURDAY AS HIGH PRESSURE BUILDS IN. MARGINAL SCA OCEAN SEAS MAY
BE POSSIBLE BY LATE WEEK WITH A PERSISTENT SOUTHERLY FLOW...BUT
LOW CONFIDENCE AT THIS POINT.
&&
.HYDROLOGY...
THERE IS THE POTENTIAL FOR A HALF TO THREE-QUARTERS OF AN INCH OF
BASIN AVERAGE RAINFALL TODAY INTO TONIGHT. LOCALLY HIGHER AMOUNTS
WILL BE POSSIBLE WITH CONVECTION. THERE IS THE POTENTIAL FOR LOCALLY
HEAVY RAINFALL WITH ANY STRONGER CONVECTION. THIS COULD CAUSE MINOR
FLOODING OF URBAN/POOR DRAINAGE AREAS.
THE PROBABILITY FOR WIDESPREAD SIGNIFICANT RAINFALL IS LOW DURING
THE LONG TERM PERIOD.
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 WEBSITE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JC/NV
NEAR TERM...JC/NV
SHORT TERM...JC
LONG TERM...NV
AVIATION...MALOIT
MARINE...JC/NV
HYDROLOGY...JC/NV