Flash Flood in New York, June 18 to 19, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
837 PM EDT THU JUN 18 2009

.SYNOPSIS...
LOW PRESSURE PASSING THROUGH THE REGION WILL LIKELY BRING MORE
SHOWERS TONIGHT...FOLLOWED BY A PERIOD OF MAINLY DRY WEATHER
FRIDAY. A STRONGER LOW PRESSURE SYSTEM WILL BRING THE POTENTIAL
FOR HEAVY RAIN SATURDAY AND SATURDAY NIGHT. A CUTOFF LOW PRESSURE
SYSTEM WILL REMAIN ANCHORED EAST OF OUR REGION THROUGH THE MIDDLE OF
NEXT WEEK...BRINGING A FEW MORE SHOWERS AND SLIGHTLY BELOW NORMAL
TEMPERATURES.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LIGHT TO MODERATE RAIN SHOWERS CONTINUE OVER EASTERN CT AND
EASTERN LONG ISLAND. SOME LIGHT SHOWERS HAVE DEVELOPED OVER
NORTHERN NJ...BUT NOTHING AS STRONG AS INDICATED ON 18Z NAM OR 18Z
GFS. AS SUCH...THINK CHANCE POPS WILL COVER THAT ARE BEST.

OTHERWISE...SHOWERS WILL TAPER OFF FROM WEST TO EAST...ENDING LATE
TONIGHT. WITH LIGHT WINDS AND ABUNDANT LOW-LEVEL MOISTURE...FOG
WILL DEVELOP AND WILL BE IN PLACE THROUGH DAYBREAK.

LOWS TONIGHT WILL BE NEARLY STEADY IN THE UPPER 50S TO LOWER 60S.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY EVENING/...
A MUCH DRIER DAY IS IN STORE FOR FRIDAY AS MODELS SHOW MID LEVEL
DRY AIR...WITH THE BULK OF THE WEAK LOW PRESSURE SYSTEM MAINLY TO
THE NORTHEAST OF THE FORECAST AREA. HOWEVER...WITH LINGERING LOW
LEVEL MOISTURE PRESENT...THERE WILL STILL BE A SMALL CHANCE OF
MAINLY AFTERNOON SHOWERS. TOTAL TOTALS INDICES CLIMB TO NEAR 46
AND SFC LIFTED INDICES REACH -2 TO -3. CANNOT RULE OUT A TSTM BUT
DID NOT INCLUDE IN THE FORECAST AS YET.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
*** THE MAIN CONCERN WILL REVOLVE AROUND THE POTENTIAL FOR HEAVY
 RAIN AND POSSIBLE FLOODING SATURDAY AND SATURDAY NIGHT ***

FRIDAY NIGHT THROUGH SATURDAY NIGHT...
A STRONG UPPER LEVEL DISTURBANCE WILL SLIDE SOUTHEAST FROM THE GREAT
LAKES FRIDAY NIGHT AND CLOSE OFF INTO A DEEP ANOMALOUS UPPER LEVEL
LOW PRESSURE SYSTEM.  THE EXACT TRACK THIS SYSTEM REMAINS A BIT
UNCERTAIN...BUT AFTER LOOKING AT THE ENSEMBLES FEEL THAT THE GFS MAY
BE TOO FAR NORTH WITH THE TRACK AND SUFFERING FROM CONVECTIVE
FEEDBACK.  THE SREF ENSEMBLES AND MOST OF OUR OTHER MODEL GUIDANCE
TAKE THE SLOW MOVING LOW PRESSURE SYSTEM SOUTHEAST...PASSING SOUTH
OF LONG ISLAND SATURDAY/SATURDAY NIGHT WHICH SEEMS TO MAKE MORE
SENSE.

MUCH OF FRIDAY NIGHT MAY END UP DRY...BUT WILL HAVE SOME CHANCE POPS
IN AS SOME SHOWERS MAY MOVE INTO THE REGION LATE. WE MAY ALSO SEE
AREAS OF FOG DEVELOP WITH A FAIR AMOUNT OF LOW LEVEL MOISTURE.

OTHERWISE...THE MAIN EVENT AND THE POTENTIAL FOR HEAVY RAIN LOOKS
TO OCCUR SATURDAY AND OR SATURDAY NIGHT. FOR NOW WILL RUN WITH
HIGH END LIKELY POPS...SINCE THERE STILL IS SOME DISAGREEMENT ON
TIMING/LOCATION OF HEAVIEST PRECIPITATION. HOWEVER...LATER SHIFTS
MAY CERTAINLY NEED TO GO WITH CATEGORICAL POPS. AS FOR
CONVECTION...THERE IS SOME ELEVATED INSTABILITY SO WILL INCLUDE A
CHANCE OF THUNDERSTORMS SATURDAY AND SATURDAY NIGHT.

THE SLOW MOVING LOW PRESSURE IS QUITE DEEP FOR THIS TIME OF YEAR AND
IS EXPECTED TO BE AROUND 995 MB AS IT PASSES SOUTH OF LONG ISLAND.
PWATS EXCEED 2 INCHES SO THE ATMOSPHERE WILL CERTAINLY BE JUICED. THIS
WILL BRING THE POTENTIAL FOR HEAVY RAINFALL TO THE REGION ALONG
WITH POSSIBLY SOME FLOODING. SINCE THERE WILL LIKELY BE CONVECTION
INVOLVED THE MODELS ARE PROBABLY GOING TO HAVE TROUBLE PINNING AN
AREA MOST SUSCEPTIBLE TO HEAVY RAIN. WILL JUST HAVE TO WAIT AND
SEE HOW THINGS EVOLVE OVER THIS TIME...BUT WE MAY EVENTUALLY NEED
A FLOOD WATCH. HOWEVER...SINCE ITS THE 4TH PERIOD FEEL THERE IS
MORE TIME TO EVALUATE THIS POTENTIAL.

AS FOR TEMPERATURES...CLOUDS AND INCREASING DEWPOINTS SHOULD HOLD
LOWS FRIDAY NIGHT AND SATURDAY NIGHT IN THE 60S.  WE FEEL THAT GFS
MOS GUIDANCE IS TOO WARM FOR HIGHS ON SATURDAY...AND WILL GO WITH
UPPER 60S TO THE 70S ACROSS MOST LOCATIONS.

SUNDAY THROUGH THURSDAY...
VERTICALLY STACKED LOW PRESSURE WILL BE VERY SLOWLY TO MOVE EAST OF
THE REGION OVER THIS TIME.  THIS MAY KEEP A NORTHEAST FLOW OF AIR
OVER THE REGION AND A CONTINUED THREAT FOR SHOWERS MUCH OF THE
TIME.  HOWEVER...ITS UNCERTAIN AS TO HOW CLOSE THE SYSTEM WILL BE TO
OUR REGION AND THE WESTWARD EXTENT OF THE PRECIPITATION SHIELD.

FOR NOW...WILL KEEP A CHANCE OF SHOWERS IN THE FORECAST THROUGH MOST
OF THE PERIOD.  WE DO NOT EXPECT IT TO BE A WASHOUT OVER THIS
TIME...AND THERE WILL LIKELY BE PLENTY OF DRY WEATHER MIXED IN.
HOWEVER...THERE CERTAINLY IS THE RISK FOR THE POTENTIAL OF SHOWERS
TO AFFECT THE REGION AND WORTH MAINTAINING CHANCE POPS.
ALSO...FEEL THAT MOS GUIDANCE IS TOO WARM OVER MUCH OF THE TIME
WITH UPPER LEVEL LOW JUST EAST OF OUR REGION. WILL KEEP HIGHS
GENERALLY IN THE MID 70S TO LOWER 80S OVER MUCH OF THE TIME...BUT
WE MAY SEE A BIT OF A MODERATION TOWARDS THE MIDDLE OF NEXT WEEK.

&&

.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
THOUGH A FEW TERMINALS HAVE LIFTED TO VFR...THIS IS EXPECTED TO BE
BRIEF...AND CIGS WILL DROP TO MVFR OVER THE NEXT HOUR OR SO...AND
THEN TO IFR BY 04Z. LIFR CONDITIONS THEN EXPECTED THROUGH THE
OVERNIGHT...GRADUALLY IMPROVING TO VFR FRI MORNING. SOME OUTLYING
AND COASTAL TERMINALS WILL NOT LIFT TO VFR UNTIL EARLY FRI
AFTERNOON.

L/V WINDS TONIGHT...THEN W-NW WINDS WILL INCREASE TO 5-10 KT
DURING THE AFTERNOON.

OUTLOOK /00Z SAT THROUGH TUE/...

FRI NIGHT THROUGH SAT NIGHT...MVFR-IFR IN HEAVY RAIN AND FOG.
SUN-TUE...SUB-VFR FROM TIME TO TIME IN SCT SHOWERS.

&&

.MARINE...
SCA REMAINS IN EFFECT FOR THE OCEAN WATERS FOR WINDS GUSTING TO 25
KNOTS AND FOR SEAS 5 FT OR GREATER TONIGHT...THEN MAINLY FOR SEAS
ON FRIDAY.

OUTLOOK /FRIDAY NIGHT THROUGH TUESDAY/...

AN ANOMALOUS VERTICALLY STACKED LOW PRESSURE SYSTEM WILL BE VERY
SLOW TO MOVE AWAY FROM THE REGION. THIS MAY RESULT IN NORTHEAST
WINDS AND SEAS AT OR ABOVE SCA AT TIMES.

&&

.HYDROLOGY...
LOCAL PONDING OF WATER WILL CONTINUE ON AREA ROADWAYS THROUGH THE
OVERNIGHT FOR MUCH OF THE AREA. WILL COVER THESE INSTANCES WITH
URBAN AND SMALL STREAM ADVISORIES. THE RAIN WILL BE MORE
SCATTERED FROM NEW YORK CITY NORTH AND WEST.

THE RAHWAY RIVER IN SPRINGFIELD NJ IS AT 4.55 FT WITH FLOOD STAGE
OF 5.5 FT...AND HAS COME DOWN FROM A CREST OF 4.84 FT.

DRIER WEATHER IS EXPECTED FRIDAY ALTHOUGH SCATTERED AFTERNOON
SHOWERS ARE STILL POSSIBLE.

SATURDAY AND SATURDAY NIGHT...
THE POTENTIAL EXISTS FOR HEAVY RAIN AND POSSIBLE FLOODING.
HOWEVER...THE AREA OF HEAVIEST RAIN REMAINS A BIT UNCERTAIN SO ITS
TOO EARLY FOR A FLOOD WATCH. HOWEVER...LATER SHIFTS WILL CERTAINLY
HAVE TO CONSIDER THE POTENTIAL FOR ONE.

&&

.TIDES/COASTAL FLOODING...

SATURDAY AND SUNDAY...
THE POTENTIAL EXISTS FOR SOME MINOR COASTAL FLOODING AT THE TIMES
OF HIGH TIDE THIS WEEKEND. VERTICALLY STACKED SYSTEM WILL CREATE A
PERSISTENT EAST TO NORTHEAST WIND AND THAT WILL COMBINED WITH A
HIGH ASTRONOMICAL TIDE. WILL HAVE TO GET A BETTER FEEL ON THE
EXACT TRACK OF THE SYSTEM/TIMING/WIND DIRECTION BEFORE WE CAN SAY
MUCH MORE.

&&

.EQUIPMENT...
THE TRANSITION FROM THE MICROART UPPER AIR SYSTEM TO THE
RADIOSONDE REPLACEMENT SYSTEM (RRS) CONTINUES. THERE WILL NOT BE
ANY SOUNDINGS TAKEN UNTIL RRS IS INSTALLED AND OPERATING. ANOTHER
MESSAGE WILL BE ISSUED INDICATING THE FIRST OFFICIAL SOUNDING WITH
THE RRS...WHICH SHOULD BE BY THE WEEK OF JUNE 22 2009.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ350-353-355.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NEW YORK NY
ISSUED BY NATIONAL WEATHER SERVICE TAUNTON MA
427 PM EDT THU JUN 18 2009

CTZ005>012-NJZ002>006-011-NYZ067>081-192030-
NORTHERN FAIRFIELD-NORTHERN NEW HAVEN-NORTHERN MIDDLESEX-
NORTHERN NEW LONDON-SOUTHERN FAIRFIELD-SOUTHERN NEW HAVEN-
SOUTHERN MIDDLESEX-SOUTHERN NEW LONDON-WESTERN PASSAIC-BERGEN-
EASTERN PASSAIC-ESSEX-HUDSON-UNION-ORANGE-PUTNAM-ROCKLAND-
NORTHERN WESTCHESTER-SOUTHERN WESTCHESTER-NEW YORK (MANHATTAN)-
BRONX-RICHMOND (STATEN ISLAND)-KINGS (BROOKLYN)-QUEENS-NASSAU-
NORTHWESTERN SUFFOLK-NORTHEASTERN SUFFOLK-SOUTHWESTERN SUFFOLK-
SOUTHEASTERN SUFFOLK-
427 PM EDT THU JUN 18 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHERN
CONNECTICUT...NORTHEAST NEW JERSEY AND SOUTHEAST NEW YORK.

.DAY ONE...TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

HEAVY RAIN WILL BE POSSIBLE SATURDAY AND SATURDAY NIGHT ACROSS THE
REGION. IT IS TOO EARLY TO DETERMINE EXACT AMOUNTS OR WHERE THE
HEAVIEST RAIN WILL OCCUR. HOWEVER...THE POTENTIAL IS THERE FOR
SOME FLOODING. THERE ALSO MAY BE A FEW EMBEDDED THUNDERSTORMS
SATURDAY AND SATURDAY NIGHT...ALTHOUGH SEVERE WEATHER IS NOT
EXPECTED AT THIS TIME.

IN ADDITION...PERSISTENT EAST TO NORTHEAST WINDS WILL BRING THE
CHANCE FOR SOME MINOR COASTAL FLOODING ALONG THE COAST DURING THE
TIMES OF HIGH TIDE SATURDAY AND SUNDAY. HOWEVER...THE EXACT TRACK
OF THE LOW PRESSURE SYSTEM REMAINS UNCERTAIN SO STAY TUNED.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

ANZ330-335-338-340-345-350-353-355-192030-
LONG ISLAND SOUND EAST OF NEW HAVEN CT/PORT JEFFERSON NY-
LONG ISLAND SOUND WEST OF NEW HAVEN CT/PORT JEFFERSON NY-
NEW YORK HARBOR-PECONIC AND GARDINERS BAYS-
SOUTH SHORE BAYS FROM JONES INLET THROUGH SHINNECOCK BAY-
MORICHES INLET NY TO MONTAUK POINT NY OUT 20 NM-
FIRE ISLAND INLET NY TO MORICHES INLET NY OUT 20 NM-
SANDY HOOK NJ TO FIRE ISLAND INLET NY OUT 20 NM-
427 PM EDT THU JUN 18 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF ATLANTIC
COASTAL WATERS.

.DAY ONE...TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

A FEW THUNDERSTORMS ARE POSSIBLE SATURDAY AND SATURDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

FRANK