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Old Greenwich, Connecticut, United States (06870)
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 Lat: 41.02N, Lon: 73.57W
Wx Zone: CTZ009 ICAO Used: KHPN
Area Discussion for County Warning Area OKX:
FXUS61 KOKX 261152
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
652 AM EST SAT DEC 26 2009

.SYNOPSIS...
LOW PRESSURE NEAR THE NORTH CAROLINA COAST WILL MOVE UP THE
EASTERN SEABOARD AND ACROSS THE LOCAL AREA TONIGHT. WEAK HIGH
PRESSURE RETURNS SUNDAY...AND IS REINFORCED BY A STRONG ARCTIC
COLD FRONT EARLY NEXT WEEK. COLD HIGH PRESSURE BUILD IN FOR THE
MID WEEK PERIOD. A STORM SYSTEM MAY IMPACT THE AREA LATE IN THE
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STACKED LOW PRES OVER THE UPPER MIDWEST...MOVES TOWARDS THE GREAT
LAKES TODAY. MODELS IN GOOD AGREEMENT WITH SECONDARY LOW PRES
TRACKING NNE UP THE EASTERN SEABOARD FROM NORTH CAROLINA TODAY.
CAN SEE SIGNS OF THE COLD AIR DAMMING WEAKENING IN THE LEE OF THE
APPALACHIANS OVER THE LAST FEW HOURS WITH HIGH PRES LIFTING INTO
THE CANADIAN MARITIME PROVINCES. MESONET/ASOS OBSERVATIONS ARE
REPORTING TEMPERATURES RIGHT AROUND THE FREEZING MARK ACROSS MANY
INTERIOR LOCATIONS WHERE THE FREEZING RAIN ADVISORY IS IN PLACE.
HAVE KEPT NOON AS THE END TIME FOR THE ADVISORY...BUT COULD SEE
THE DAY SHIFT TAKING IT DOWN A FEW HOURS EARLIER WITH TEMPS
ALREADY MARGINAL EARLY THIS MORNING. A FEW LOCATIONS ALONG
COASTAL CT ARE ALSO REPORTING FREEZING TEMPS...BUT DON'T FEEL ITS
WIDESPREAD ENOUGH TO WARRANT EXPANDING THE ADVISORY. WILL CONTINUE
TO HIGHLIGHT WITH SPS. ELSEWHERE...TEMPS WILL REMAIN ABOVE
FREEZING FOR THE DURATION OF THE EVENT WITH PLAIN RAIN EXPECTED.

A BIT OF A LULL IN PRECIP EARLY THIS MORNING...BUT EXPECTING IT
TO FILL BACK IN OVER THE NEXT FEW HOURS AS BETTER UPPER FORCING
ENTERS THE REGION WITH THE APPROACH OF THE LOW.

HIGHS GENERALLY IN THE MID TO UPPER 30S ACROSS INTERIOR
LOCATIONS...LOWER TO MID 40S AT THE COAST WITH THE FLOW OFF OF THE
WARMER OCEAN WATERS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
LOW MOVES ACROSS THE LOCAL AREA TONIGHT WITH RAIN CONTINUING
OVERNIGHT. WINDS WILL WEAKEN AS IT MOVES ACROSS AND THE
COMBINATION OF SOMEWHAT WARMER TEMPS OVER A COLD SNOW
PACK...ABUNDANT LOW LEVEL MOISTURE AND LIGHT WINDS SHOULD ALLOW
AREAS OF FOG TO DEVELOP. RAIN TAPERS FROM WEST TO EAST SUN
MORNING WITH WEAK HIGH PRES BUILDING IN AND WINDS BECOMING
WESTERLY.

WINDS ALOFT INCREASE TO 40 TO 50 KT TODAY...BUT SFC INVERSION
SHOULD KEEP MOST OF THIS FROM MIXING TO THE SFC. GUSTS UP TO 40
MPH POSSIBLE..ESP ALONG THE COAST.

VIGOROUS SHORTWAVE APPROACHES SUN NIGHT/MON...BUT THERE ARE TIMING
DIFFERENCES AMONGST SHORT RANGE MODEL SOLUTIONS. GENERALLY
EXPECT SNOW SHOWERS INLAND...BUT TOUGH TO SAY IF IT WILL BE LIQUID
OR FROZEN PTYPE AT THE COAST. HAVE RAIN OR SNOW SHOWERS FOR NOW.

TEMPS ARE EXPECTED TO BE ABOVE NORMAL THROUGH THE DAY SUN...THEN
AT TO SLIGHTLY NORMAL BELOW NORMAL SUN NIGHT/MON.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
DEEP TROUGHING OVER THE REGION TO START THE PERIOD WITH WELL BELOW 
NORMAL TEMPS. ARCTIC COLD FRONT CROSSES THROUGH THE REGION MON NIGHT 
IN WAKE OF INITIAL COLD FRONT WITH CLIPPER SYSTEM. WINDS MAY BRIEFLY 
GUST CLOSE TO WIND ADVISORY WITH TEMPS FALLING INTO THE TEENS AND 
LOWER 20S AREAWIDE. WIND CHILLS FALLING INTO THE LOWER SINGLE 
DIGITS CITY/COAST AND SINGLE DIGITS BELOW ZERO INTERIOR. A FEW SNOW 
SHOWERS POSSIBLE BEHIND THE ARCTIC FRONT.

WINDY AND COLD TEMPS TUES WITH TEMPS LIKELY NOT GETTING OUT OF THE 
20S AREAWIDE.

HIGH PRESSURE BUILDS OVER THE REGION TUES NIGHT WITH GOOD 
RADIATIONAL COOLING CONDS LIKELY.

SLOW MODERATION THROUGH MID WEEK AS UPPER FLOW BECOMES MORE ZONAL 
AND HIGH PRESSURE SLIDES OFFSHORE...BUT STILL BELOW SEASONABLE. THEN 
WILL HAVE TO KEEP AN EYE ON POSSIBLE PHASING OF NORTHERN AND 
SOUTHERN STREAM ENERGY ACROSS THE CENTRAL US ON THURS...WHICH WOULD 
HAVE IMPLICATIONS OF A POSSIBLE COASTAL STORM TO END THE WEEK.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
LOW PRESSURE NEAR NC/VA TRACKS NORTHEAST TODAY TOWARD NYC METRO.
STRONG EAST FLOW PREVAILS OUT AHEAD OF THIS LOW...SUSTAINED 15 TO
20 KTS WITH GUSTS AROUND 25 KTS. ON AND OFF RAIN EXPECTED...WITH
MAINLY IFR CIGS ANTICIPATED.

BY TONIGHT...WINDS TURN TO THE EAST/SOUTHEAST AND LIGHTEN AFTER
00Z AS THE LOW NEARS. COULD BE A PERIOD OF VARIABILITY IN THE
WINDS DEPENDING ON EXACT TRACK OF THE LOW. BEST GUESS IS FOR WINDS
TO TURN TO THE SOUTH...THEN SOUTHWEST OVERNIGHT AROUND 10 KTS.
BOUNDARY LAYER REMAINS SATURATED...AND EXPECT VSBYS TO LOWER TO
IFR OVERNIGHT AS WINDS LIGHTEN. CONDITIONS SLOWLY IMPROVE AROUND
SUNRISE SUNDAY AS THE LOW DEPARTS TO THE NORTH AND EAST AND WINDS
BECOME WESTERLY...SCOURING OUT ANY STRATUS.

OUTLOOK 12Z SUNDAY THROUGH WEDNESDAY...
BECOMING VFR SUNDAY MORNING.
POSSIBLE SUB VFR AT TIMES MONDAY.
VFR WITH STRONG NW WINDS TUE.
VFR WITH DIMINISHING WINDS WED.

&&

.MARINE...
WATERS REMAIN BETWEEN DEPARTING HIGH PRESSURE TO THE NORTHEAST AND 
LOW PRESSURE RIDING ALONG MID ATLANTIC COAST TOWARD THE WATERS. A 
TIGHT PRESSURE GRADIENT RESULTS...WITH GALE CONDITIONS ACROSS THE 
WATERS EXCEPT PERHAPS NY HARBOR AND WESTERN LI SOUND. THE LOW 
TRAVERSES ACROSS THE WATERS TONIGHT...ALLOWING WINDS TO ABATE. THEN 
WINDS SHIFT TO THE WEST SUNDAY BEHIND THE LOW/FRONT. A SERIES OF 
WEAK TROUGHS MOVE ACROSS THE WATERS THROUGH MONDAY...BUT AN ARCTIC 
FRONT MONDAY NIGHT WILL USHER IN NORTHWEST GALES TUESDAY...ALONG 
WITH VERY COLD TEMPERATURES. WINDS GRADUALLY DIMINISH WEDNESDAY AS A 
RIDGE OF HIGH PRESSURE BUILDS. NEED TO KEEP AN EYE ON POTENTIAL CSTL 
STORM THEREAFTER.

FOLLOWED WAVE WATCH III SEA FORECASTS CLOSELY. EXPECT ROUGH 
CONDITIONS OUT ACROSS THE WATERS TODAY IN STRONG EAST FLOW. SEAS 
REMAIN ROUGH FOR QUITE SOME TIME...BUT SOME IMPROVEMENT EXPECTED 
INTO MONDAY. NW GALES KEEP SEAS RATHER ROUGH TUESDAY...THEN SEAS 
SHOULD SUBSIDE WEDNESDAY WITH THE APPROACH OF HIGH PRESSURE.

&&

.HYDROLOGY...
STILL EXPECTING AROUND AN INCH OF QPF ON AVERAGE ACROSS THE LOCAL
AREA THROUGH SUN MORNING. THE HIGHER QPF VALUES (JUST OVER AN
INCH) ARE EXPECTED TO FALL ACROSS WESTERN AREAS WHERE THERE IS
LESS SNOW PACK/WATER EQUIVALENT QPF. AROUND 2 INCH WATER
EQUIVALENT QPF REMAINS IN THE SNOW PACK ACROSS EASTERN
AREAS...WHERE BETWEEN 3/4 AND 1 INCH OF RAINFALL IS EXPECTED TO
FALL. THE COMBINATION OF THE SNOW PACK AND RAINFALL WILL LIKELY
LEAD TO MINOR NUISANCE URBAN FLOODING. RIVER AND STREAM FLOODING
NORTH AND WEST OF NYC IS LESS LIKELY TO OCCUR DUE TO LESS OF A
SNOW PACK.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR CTZ005>008.
NY...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NYZ067>070.
NJ...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NJZ002.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ335-
     338.
     GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR ANZ330-340-350-353.
     GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ345-355.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...


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