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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KOKX 271100
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
700 AM EDT SUN JUL 27 2014

.SYNOPSIS...
A WARM FRONT APPROACHING FROM THE SOUTHWEST WILL LIFT THROUGH THE
AREA LATER TODAY. AS A COLD FRONT APPROACHES TONIGHT...A
STRENGTHENING AREA OF LOW PRESSURE WILL TRACK FROM THE EASTERN GREAT
LAKES TO SOUTHERN NEW ENGLAND BY MORNING. THE LOW WILL TRACK
THROUGH NEW ENGLAND ON MONDAY AS THE COLD FRONT MOVES ACROSS THE
LOCAL AREA...REMAINING JUST TO THE EAST THROUGH TUESDAY. HIGH
PRESSURE BUILDS IN FOR THE SECOND HALF OF THE WEEK BEFORE THE NEXT
LOW PRESSURE SYSTEM APPROACHES NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
FORECAST IS GENERALLY ON TRACK. MADE SOME MINOR ADJUSTMENTS TO
POPS BASED ON LATEST RADAR IMAGERY AND TRENDS. ACTIVITY IS A BIT
SLOWER THAN ORIGINALLY EXPECTED. LATEST THINKING IS THAT THE LINE
CURRENTLY OVER EASTERN PA HOLDS TOGETHER IMPACTING THE WESTERN
HALF OF THE FORECAST AREA BETWEEN 13Z AND 15Z AND CONTINUING EWD
THROUGH 18Z.

WARM FRONT WAS ORIENTED FROM JUST N OF KWAL...KBWI...KIPT...KROC
AS OF 10Z. IT WILL CONTINUE TO LIFT NEWD PASSING THROUGH THE LOCAL
AREA LATER TODAY WITH A MORE HUMID AIRMASS IN ITS WAKE. THETA-E
ADVECTION ACROSS THE AREA THIS MORNING WILL INCREASE MOISTURE AND
INSTABILITY AS THE LEFT EXIT REGION OF AN 80KT H25 JET APPROACHES.
THIS IS EXPECTED TO TRIGGER SHRA/TSTM ACTIVITY ACROSS EASTERN
PA/WESTERN NJ AND CONTINUE THROUGH THE MORNING AS IT TRACKS EWD.
INSTABILITY IS WEAK THIS MORNING...BUT SHEAR IS MODERATE AND BEING
IN THE LEFT EXIT REGION OF THE UPPER JET COULD RESULT IN A FEW
STRONG STORMS...ESPECIALLY AFTER 12Z. WITH THE WARM FRONT
NEARBY...CAN`T RULE OUT A FEW ROTATING STORMS WITH A VEERING LOW
LEVEL WIND PROFILE...AND LCL`S AOB 1K FT E OF NYC. HI RES MODELS
ARE IN DECENT AGREEMENT IN INCREASING ACTIVITY THIS
MORNING...WHICH COULD IMPACT WHAT HAPPENS LATER TODAY.

ONCE THE FRONT LIFTS THROUGH THE AREA...THERE COULD BE SEVERAL
HOURS OF DRY WEATHER BEFORE THE NEXT SHORTWAVE IMPACTS THE AREA.
EXPECT PARTIAL CLEARING FOR A FEW HOURS WHICH WILL DETERMINE THE
AMOUNT OF DESTABILIZATION THAT OCCURS AS THE POTENT SHORTWAVE AND
STRENGTHENING SFC LOW APPROACHES FOR THE EVENING. ANOTHER ROUND OF
SHRA/TSTMS IS EXPECTED WITH THIS FEATURE...WITH THE POTENTIAL FOR
A MORE SIGNIFICANT SVR WEATHER EVENT. 0-6KM SHEAR WILL AGAIN BE
MODERATE...APPROACHING STRONG LEVELS WITH 0-1KM SHEAR BETWEEN
15-20 KTS AND INCREASING HELICITY BETWEEN 00Z AND 06Z. THERE IS
SOME SLIGHT TIMING DIFFERENCES BETWEEN THE GUIDANCE...BUT THIS
APPEARS TO BE THE BETTER CHANCE FOR ROTATING STORMS. SPC HAS
PLACED THE ENTIRE AREA IN A SLIGHT RISK...WITH A 5 PERCENT CHANCE
FOR TORNADOES IN NYC AND WESTERN LONG ISLAND AND A 2 PERCENT CHC
ELSEWHERE. OTHERWISE...DAMAGING WINDS AND LARGE HAIL HAVE ABOUT
THE SAME CHANCE OF OCCURRING...OUTSIDE OF THE AFOREMENTIONED AREAS
WHERE THERE IS A 30 PERCENT CHANCE OF THUNDERSTORM WIND
DAMAGE...WITH WET BULB ZERO HEIGHTS NEAR OR SLIGHTLY BELOW 10K FT.

AS THE LOW TRACKS INTO SOUTHERN NEW ENGLAND TONIGHT...THE BEST
DYNAMICAL FORCING WILL LIFT N AND E BRINGING AN END TO THE SVR
THREAT. THE TIMING WILL NEED TO BE REFINED LATER TODAY AS THINGS
UNFOLD...BUT EXPECT ACTIVITY TO LINGER THROUGH MUCH IF NOT ALL OF
THE NIGHT...ESPECIALLY EASTERN AREAS.

THERE IS A MODERATE RISK FOR THE DEVELOPMENT OF RIP CURRENTS ALONG
THE ATLANTIC OCEAN FACING BEACHES THROUGH THIS EVENING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
LOW TRACKS THROUGH NEW ENGLAND ON MONDAY AS ITS ATTENDING COLD
FRONT MOVES ACROSS THE AREA. POTENTIAL FOR SCT CONVECTION DURING
THE AFTN...WITH A FEW STRONG STORMS MAINLY E OF NYC...BUT WILL
DEPEND ON FRONTAL PROGRESSION. HIGHS ARE ALSO TROUBLESOME DUE TO
THIS. FRONT SHOULD CLEAR THE AREA MON EVE AND REMAIN JUST E OF THE
AREA THROUGH TUE. A MORE COMFORTABLE AIRMASS WILL FOLLOW IN THE
WAKE OF THE FRONT.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL BEGIN TO BUILD IN TUE NIGHT AND SHOULD TAKE HOLD
OF THE AREA THROUGH THE END OF THE WEEK. MODEL DISCREPANCIES IN
THE HANDLING OF THE NEXT LOW PRESSURE SYSTEM BUT SOME FORM OF LOW
PRESSURE WILL BEGIN TO APPROACH BY NEXT WEEKEND...THOUGH COULD
HOLD OFF ANY IMPACTFUL WEATHER TILL THE WORK WEEK.

CONCERNING THE PCPN FOR MONDAY...WILL BE WATCHING THE PATH THE LOW
TAKES AS IT FORMS SUNDAY NIGHT. RIGHT NOW THE AREA WILL REMAIN
POSITIONED BETWEEN A WARM FRONT TO THE NORTH AND THE COLD FRONT TO
THE WEST. AS SUCH...EXPECTING DECENT INSTABILITY AND SHEAR IN PLACE
TO ALLOW FOR TSTM DEVELOPMENT. QUESTION REMAINS THOUGH OF WHERE/WHEN
THE SHORTWAVES PIVOT AROUND THE UPPER LVL TROUGH. MODELS AGREE ON
STRONG VORT MAX OVER NE PA BY 18Z MON THEN LIFTING ON INTO NEW
ENGLAND...JUST SKIRTING THE NORTHERN FRINGES OF THE AREA. WHILE
THERE WONT BE A LACK OF FORCING ALOFT OVER THE REMAINDER OF THE
AREA...IT WILL BE ON THE WEAKER END. SO WITH THIS
THINKING...MAINTAINED CHC POPS BASICALLY NYC METRO AND TO THE EAST
AND SOUTH...WHILE INCLUDING LIKELY POPS TO THE NORTH AND WEST WITH
NOW CONSECUTIVE MODEL RUNS HINTING AT THE SECONDARY LOW FORMATION.
STRONGER STORMS ARE NOT OUT OF THE QUESTION...THINKING MORE TO THE
NORTH AND EAST OVER PORTIONS OF CT WITH THE BETTER FORCING AND THE
ASSISTANCE OF THE COLD FRONT AT THE SFC.

PCPN WILL CLEAR THE AREA MON NIGHT ON INTO TUES MORNING. ANOTHER
SHORTWAVE PIVOTING THE TROUGH COULD BRING SLIGHT CHC OF TSTMS TUES
AFTN. DESPITE MULTIPLE WEAKER SHORTWAVES PROGRESSING THROUGH MID
WEEK...EXPECTING A MUCH DRIER AIRMASS IN PLACE AS THE HIGH BUILDS IN
WITH NOTHING TO ASSIST IN TRIGGERING ANY CONVECTION. THE QUESTION
THEN TURNS TO THE PCPN CHCS FOR THE COMING WEEKEND. WITH SUCH A
SPREAD IN THE GLOBAL MODEL SOLUTIONS...WILL MAINTAIN SLIGHT CHC
WORDING FOR NOW. OTHER THAN MONDAY...EXPECTING TEMPS A FEW DEGREES
BELOW NORMAL FOR THE COMING WEEK WITH THE PERSISTENT NW-N FLOW.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
WARM FRONT MOVES NORTHWARD TODAY AS A COLD FRONT APPROACHES TONIGHT.

MAINLY VFR...BUT WILL MONITOR THUNDERSTORMS THAT COULD IMPACT THE
NYC METRO AIRPORTS AROUND 14Z...AND A BIT LATER EAST. AFTER THIS
ACTIVITY MOVES EAST...THERE WILL BE CLEARING WITH ANOTHER ROUND OF
STORMS TOWARD EVENING. ANY STORM COULD PRODUCE STRONG GUSTY WINDS
AND HAIL.

SOUTH WINDS 10 TO 15 KTS CAN BE EXPECTED THROUGH TODAY AND INTO
TONIGHT.

.OUTLOOK FOR 12Z MON THROUGH THU...
.MON...MAINLY VFR. CHC SHRA/TSTMS. CHC TEMPO SUB-VFR.
.TUE-THU...VFR.

&&

.MARINE...
SOUTHERLY WINDS INCREASE TODAY AND TONIGHT AHEAD OF LOW PRESSURE
AND ASSOCIATED COLD FRONT. OCEAN SEAS BUILD TO MARGINAL SCA AS A
RESULT BY LATE TODAY AND THROUGH TONIGHT. SEAS REMAIN RATHER ROUGH
MONDAY.

THE APPROACHING COLD FRONT MONDAY COULD INCREASE GUSTS TO AROUND 25
KTS...ESPECIALLY ON THE OCEAN WATERS. THEN WINDS TURN TO THE WEST
LATE IN THE DAY...WITH A FEW GUSTS OF 25 TO 30 KTS POSSIBLE BEHIND
THE FRONT FOR A SHORT TIME.

WINDS DIMINISH QUICKLY MONDAY NIGHT...ALLOWING SEAS TO SUBSIDE BY
TUESDAY.

HIGH PRESSURE BUILDS OVER THE WATERS MID TO LATE WEEK.

&&

.HYDROLOGY...
UNSETTLED WEATHER WITH SCATTERED TO NUMEROUS SHOWERS/TSTMS ARE
FORECAST THROUGH MONDAY. ANY OF THESE STORMS HAVE THE POTENTIAL
TO PRODUCE HEAVY DOWNPOURS. SOME UNCERTAINTY STILL EXISTS
WITH TIMING AND COVERAGE OF THUNDERSTORMS THOUGH. IT LOOKS LIKE
THE HIGHER POTENTIAL FOR HEAVY RAIN IS LATE THIS AFTN AND TONIGHT
WITH HIGHER PWATS OF 1.5 TO 2 INCHES ACROSS THE REGION. MINOR
URBAN FLOODING IS POSSIBLE WITH THESE HEAVY DOWNPOURS...BUT FLASH
FLOODING IS NOT EXPECTED SINCE STORMS SHOULD BE MOVING AND
TRAINING IS NOT ANTICIPATED.

NO SIGNIFICANT RAINFALL THEN EXPECTED FOR THE REMAINDER OF THE
WEEK.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 PM EDT
     MONDAY FOR ANZ350-353-355.

&&

$$