000
FXUS61 KOKX 010745
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE UPTON NY
340 AM EDT FRI SEP 1 2006
...WINDY AND WET WEATHER FORTHCOMING TONIGHT THROUGH SATURDAY...
.NEAR TERM (TODAY)...
FXUS61 KOKX 010745
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE UPTON NY
340 AM EDT FRI SEP 1 2006
...WINDY AND WET WEATHER FORTHCOMING TONIGHT THROUGH SATURDAY...
.NEAR TERM (TODAY)...
TROPICAL STORM ERNESTO CONTINUES TO CHUG ITS WAY NORTHWARD THROUGH NORTH CAROLINA AS OF EARLY FRIDAY MORNING. CONFLUENT FLOW OVER THE CANADIAN MARITIMES WILL ALLOW SFC HIGH PRESSURE OVER QUEBEC TO STRENGTHEN TODAY AS IT MOVES SOUTHEASTWARD. THIS HIGH WILL PROVIDE THE TRI-STATE AREA WITH FAIR WEATHER TODAY. WHILE LOW AND MID LEVELS WILL REMAIN DRY TODAY...CIRRUS WILL CONTINUE TO OVERSPREAD THE AREA AS ERNESTO'S EXHAUST KEEPS PUMPING MOISTURE UP THE COAST IN THE UPPER LEVELS. THIS WILL GIVE THE SKY A MOSTLY CLOUDY TO PERHAPS PARTLY SUNNY APPEARANCE TODAY...BUT THICKENING WILL BE NOTED AS THE DAY WEARS ON. TODAY WILL BE PRECIP-FREE THANKS TO THE LOW LEVEL DRY AIR IN PLACE.
AS FOR TEMPERATURES...TOOK A BLEND OF THE GUIDANCE... WHICH MEANS MAXES IN THE LOWER TO MID 70S AREA-WIDE. EASTERLY WINDS WILL NOTICEABLY INCREASE THIS AFTERNOON.
AS FOR TEMPERATURES...TOOK A BLEND OF THE GUIDANCE... WHICH MEANS MAXES IN THE LOWER TO MID 70S AREA-WIDE. EASTERLY WINDS WILL NOTICEABLY INCREASE THIS AFTERNOON.
THE GRIDS/FORECAST ARE IN GOOD SHAPE...ONLY MINOR TWEAKS TO THE HOURLY TEMPS...
DEWS AND WINDS TO ACCOUNT FOR CURRENT CONDITIONS.
.SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...
THE FORECAST GETS COMPLICATED TONIGHT AS THERE WILL BE SEVERAL FACTORS COMING INTO PLAY THAT WILL AFFECT OUR WEATHER. ERNESTO WILL CONTINUE TO WEAKEN AS IT HEADS NORTHWARD INTO EASTERN VIRGINIA. HOWEVER...
STRONG HIGH PRESSURE (ON THE ORDER OF 1030MB) WILL CONTINUE TO BUILD SOUTHEASTWARD ACRS THE REGION...
CREATING THE PROVERBIAL BATTLE OF THE AIRMASSES. WE'LL BE CAUGHT IN THE MIDDLE FOR THE MOST PART.
MAIN CONCERNS STARTING TONIGHT ARE:
1) WHEN DO ERNESTO'S RAINS ARRIVE,
2) HOW HEAVY WILL THE RAINS BE, AND
3) HOW WINDY DOES IT GET IN BETWEEN THE TWO PRESSURE SYSTEMS.
THE ARRIVAL OF THE RAINFALL IS QUITE PROBLEMATIC AS THE NORTHWARD ADVECTION OF THE MOISTURE WILL BUTT UP AGAINST SOME RATHER DRY AIR OWING TO THE STRONG HIPRES SYSTEM TO THE NORTH. THE GFS HAS BEEN QUITE CONSISTENT WITH THE MOVEMENT OF THE RAIN SHIELD...
BUT WILL SLOW THAT SOLUTION DOWN A BIT DUE TO THE DRY AIRMASS IN PLACE. WILL BASICALLY BRING IN CATEGORICAL POPS FROM SOUTH TO NORTH BETWEEN 06Z AND 12Z. THE EXCEPTION WILL BE SOUTHEAST CT WHERE THE STEADIER RAINS WILL BE SLOWER TO MOVE IN.
OF COURSE...WITH ANY TROPICAL SYSTEM...RAINFALL RATES WILL MOST LIKELY BE HEAVY. THE HEAVIEST RAIN WILL FALL TO THE SOUTH OF THIS AREA...BUT AN IMPRESSIVE LOW LEVEL JET WILL BE PUMPING IN MOISTURE FROM THE SOUTHEAST. WILL SIDE WITH HPC RAINFALL AMOUNTS WHICH BRING ABOUT 2.5" OF RAINFALL TO THE WESTERN HALF OF THE CWA DURING THE FRIDAY NIGHT-SATURDAY NIGHT TIMEFRAME. NW ZONES WILL HAVE THE ADDED COMPONENT OF UPSLOPE...SO AMOUNTS COULD BE ENHANCED THERE. THIS COMBINED WITH THE FACT THAT WE'VE HAD SOME HEAVY RAINS AS OF LATE BEHOOVES ME TO ISSUE A FLASH FLOOD WATCH FOR THE LOWER HUDSON VALLEY/NORTHEAST NJ/NYC FROM EARLY SAT MORNING THROUGH MOST OF SATURDAY NIGHT. POINTS EAST WILL SEE LESSER AMOUNTS OF RAINFALL (1-2") SO WILL HOLD OFF ON WATCH THERE. WILL STILL HAVE TO WATCH ALL AREAS FOR TRAINING WHICH COULD PROMPT MUCH HIGHER LOCAL AMOUNTS.
THE RAINFALL SHOULD TAPER OFF SATURDAY NIGHT...BUT NOT COMPLETELY END.
THE WINDS ARE MY NEXT CONCERN. THE SFC PRESSURE GRADIENT TIGHTENS MARKEDLY OVERNIGHT TONIGHT THROUGH AT LEAST 18Z SATURDAY. GIVEN THAT ERNESTO IS ABOUT 10MB STRONGER THAN THE GFS...THE PRESSURE GRADIENT COULD EVEN END UP SLIGHTLY STRONGER THAN PROGGED.
LOW LEVEL JET GETS CRANKING...WITH THE GFS SHOWING 50-60 KTS OF WIND FROM 975MB TO 850MB DEVELOPING TONIGHT INTO SATURDAY. THIS IS PROBABLY OVERDONE BY SOME MINOR DEGREE...BUT I THINK IT'S CLOSE GIVEN THE MAGNITUDE OF THE HIGH TO THE NORTH AND ERNESTO TO THE SOUTH. IT LOOKS AS THROUGH THE STRONGEST PRESSURE GRADIENT AND LLJ SPEEDS WILL COINCIDE WITH THE BEST CHANCE FOR CONVECTIVE PRECIP ...LATE TONIGHT INTO SATURDAY MORNING...WHICH COULD BRING THOSE LLJ WINDS DOWN...ESPECIALLY NEAR THE COAST. IN ADDITION...IT'S SEPT 1ST. THE ATLC WATER TEMPS ARE STILL AROUND 70F. THIS WILL NOT ALLOW A STRONG INVERSION TO DEVELOP NEAR THE SFC LIKE WE WOULD SEE IN THE COOL SEASON.
IN ANY EVENT...I HAVE DECIDED TO ISSUE A HIGH WIND WATCH FOR LONG ISLAND AND PARTS OF NYC FOR LATE TONIGHT THROUGH EARLY SATURDAY AFTERNOON. THIS MAINLY FOR WIND GUSTS POSSIBLY REACHING 60 MPH IN THE CONVECTIVE SHOWERS. THE DAY SHIFT WILL BE ABLE TO REASSESS THE SITUATION AND SEE IF A HIGH WIND WARNING OR ADVISORY WILL BE NEEDED FOR THESE AREAS. IT'LL PROBABLY BE THE LATTER...BUT FEEL A HIGH WIND WATCH IS PRUDENT FOR THE COASTAL ZONES AT THIS TIME (EXCEPT FOR CT). ADVISORIES MAY NEED TO GO UP FOR SOME INLAND ZONES AS WELL...BUT DAY SHIFT WILL ASSESS THAT POSSIBILITY AS WELL. WINDS ARE EXPECTED TO RELAX AS SATURDAY AFTERNOON WEARS ON.
DEWS AND WINDS TO ACCOUNT FOR CURRENT CONDITIONS.
.SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...
THE FORECAST GETS COMPLICATED TONIGHT AS THERE WILL BE SEVERAL FACTORS COMING INTO PLAY THAT WILL AFFECT OUR WEATHER. ERNESTO WILL CONTINUE TO WEAKEN AS IT HEADS NORTHWARD INTO EASTERN VIRGINIA. HOWEVER...
STRONG HIGH PRESSURE (ON THE ORDER OF 1030MB) WILL CONTINUE TO BUILD SOUTHEASTWARD ACRS THE REGION...
CREATING THE PROVERBIAL BATTLE OF THE AIRMASSES. WE'LL BE CAUGHT IN THE MIDDLE FOR THE MOST PART.
MAIN CONCERNS STARTING TONIGHT ARE:
1) WHEN DO ERNESTO'S RAINS ARRIVE,
2) HOW HEAVY WILL THE RAINS BE, AND
3) HOW WINDY DOES IT GET IN BETWEEN THE TWO PRESSURE SYSTEMS.
THE ARRIVAL OF THE RAINFALL IS QUITE PROBLEMATIC AS THE NORTHWARD ADVECTION OF THE MOISTURE WILL BUTT UP AGAINST SOME RATHER DRY AIR OWING TO THE STRONG HIPRES SYSTEM TO THE NORTH. THE GFS HAS BEEN QUITE CONSISTENT WITH THE MOVEMENT OF THE RAIN SHIELD...
BUT WILL SLOW THAT SOLUTION DOWN A BIT DUE TO THE DRY AIRMASS IN PLACE. WILL BASICALLY BRING IN CATEGORICAL POPS FROM SOUTH TO NORTH BETWEEN 06Z AND 12Z. THE EXCEPTION WILL BE SOUTHEAST CT WHERE THE STEADIER RAINS WILL BE SLOWER TO MOVE IN.
OF COURSE...WITH ANY TROPICAL SYSTEM...RAINFALL RATES WILL MOST LIKELY BE HEAVY. THE HEAVIEST RAIN WILL FALL TO THE SOUTH OF THIS AREA...BUT AN IMPRESSIVE LOW LEVEL JET WILL BE PUMPING IN MOISTURE FROM THE SOUTHEAST. WILL SIDE WITH HPC RAINFALL AMOUNTS WHICH BRING ABOUT 2.5" OF RAINFALL TO THE WESTERN HALF OF THE CWA DURING THE FRIDAY NIGHT-SATURDAY NIGHT TIMEFRAME. NW ZONES WILL HAVE THE ADDED COMPONENT OF UPSLOPE...SO AMOUNTS COULD BE ENHANCED THERE. THIS COMBINED WITH THE FACT THAT WE'VE HAD SOME HEAVY RAINS AS OF LATE BEHOOVES ME TO ISSUE A FLASH FLOOD WATCH FOR THE LOWER HUDSON VALLEY/NORTHEAST NJ/NYC FROM EARLY SAT MORNING THROUGH MOST OF SATURDAY NIGHT. POINTS EAST WILL SEE LESSER AMOUNTS OF RAINFALL (1-2") SO WILL HOLD OFF ON WATCH THERE. WILL STILL HAVE TO WATCH ALL AREAS FOR TRAINING WHICH COULD PROMPT MUCH HIGHER LOCAL AMOUNTS.
THE RAINFALL SHOULD TAPER OFF SATURDAY NIGHT...BUT NOT COMPLETELY END.
THE WINDS ARE MY NEXT CONCERN. THE SFC PRESSURE GRADIENT TIGHTENS MARKEDLY OVERNIGHT TONIGHT THROUGH AT LEAST 18Z SATURDAY. GIVEN THAT ERNESTO IS ABOUT 10MB STRONGER THAN THE GFS...THE PRESSURE GRADIENT COULD EVEN END UP SLIGHTLY STRONGER THAN PROGGED.
LOW LEVEL JET GETS CRANKING...WITH THE GFS SHOWING 50-60 KTS OF WIND FROM 975MB TO 850MB DEVELOPING TONIGHT INTO SATURDAY. THIS IS PROBABLY OVERDONE BY SOME MINOR DEGREE...BUT I THINK IT'S CLOSE GIVEN THE MAGNITUDE OF THE HIGH TO THE NORTH AND ERNESTO TO THE SOUTH. IT LOOKS AS THROUGH THE STRONGEST PRESSURE GRADIENT AND LLJ SPEEDS WILL COINCIDE WITH THE BEST CHANCE FOR CONVECTIVE PRECIP ...LATE TONIGHT INTO SATURDAY MORNING...WHICH COULD BRING THOSE LLJ WINDS DOWN...ESPECIALLY NEAR THE COAST. IN ADDITION...IT'S SEPT 1ST. THE ATLC WATER TEMPS ARE STILL AROUND 70F. THIS WILL NOT ALLOW A STRONG INVERSION TO DEVELOP NEAR THE SFC LIKE WE WOULD SEE IN THE COOL SEASON.
IN ANY EVENT...I HAVE DECIDED TO ISSUE A HIGH WIND WATCH FOR LONG ISLAND AND PARTS OF NYC FOR LATE TONIGHT THROUGH EARLY SATURDAY AFTERNOON. THIS MAINLY FOR WIND GUSTS POSSIBLY REACHING 60 MPH IN THE CONVECTIVE SHOWERS. THE DAY SHIFT WILL BE ABLE TO REASSESS THE SITUATION AND SEE IF A HIGH WIND WARNING OR ADVISORY WILL BE NEEDED FOR THESE AREAS. IT'LL PROBABLY BE THE LATTER...BUT FEEL A HIGH WIND WATCH IS PRUDENT FOR THE COASTAL ZONES AT THIS TIME (EXCEPT FOR CT). ADVISORIES MAY NEED TO GO UP FOR SOME INLAND ZONES AS WELL...BUT DAY SHIFT WILL ASSESS THAT POSSIBILITY AS WELL. WINDS ARE EXPECTED TO RELAX AS SATURDAY AFTERNOON WEARS ON.
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