FXUS61 KBUF 060506
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
1206 AM EST SUN DEC 6 2009
.SYNOPSIS...
HIGH PRESSURE BUILDING FROM THE OHIO VALLEY WILL BRING AN END TO THE
LAKE EFFECT SNOW SHOWERS SOUTHEAST OF THE LAKES BY SUNDAY MORNING.
AS THE HIGH SLIDES OFF THE EAST COAST MONDAY...A WEAK LOW WILL TRACK
EAST FROM THE CENTRAL GREAT LAKES AND BRING A GENERAL LIGHT SNOW TO
THE AREA. A STRONGER WINTER STORM IS POSSIBLE FOR MID WEEK WITH MUCH
COLDER CONDITIONS FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
BUFKIT PROFILE FOR JAMESTOWN SHOWS FLOW OFF LK ERIE OSCILLATING
BETWEEN 320 AND 300 DEGREES AND SINCE IT HAS BECOME MORE WNW THE
AREA OF ACTIVITY HAS BECOME A BIT WIDER IN AREAL COVERAGE AND HAS
EXTENDED FURTHER INLAND INTO CATTARAUGUS COUNTY AS EXPECTED BY
EARLIER UPDATE. WILL CONTINUE WITH HIGH LKLY POPS ACROSS SOUTHERN TIER
WITH ACCUMULATIONS OF 1 TO 3 INCHES IN MOST PERSISTENT LAKE SNOWS
WITH ACTIVITY MORE SCT IN SOUTHERN ERIE COUNTY. HAVE BROUGHT IN
CHC OF A FEW FLRYS INTO WESTERN PORTIONS OF NIAGARA FRONTIER AS
WELL TIL ARND 07Z AND CHC OF FLRYS LTR TNGT INTO ALLEGANY COUNTY
AS WELL.
OFF LK ONTARIO, HAVE RAISED POPS TO HIGH LKLY RANGE AS WELL OVER
OSWEGO COUNTY THROUGH AROUND 07Z. LATER TONIGHT AS FLOW BECOMES
MORE WNW SHLD SHIFT A BIT FURTHER WEST INTO NORTHERN CAYUGA AND
EASTERN WAYNE COUNTIES SO WILL GO WITH CHC POPS THERE EAST INTO
SW OSWEGO COUNTY. IN OSWEGO COUNTY WILL ALSO GO WITH 1 TO 3 INCHES
OF ACCUMULATION IN MOST PERSISTENT LAKE SNOWS.
ELSEWHERE GENLY PTLY-MSTLY CLDY SKIES.
HIGH PRESSURE WILL BUILD TO THE SOUTH OF US SUNDAY. WE WILL GET AN
INCREASING WEST TO SOUTHWEST FLOW. PARTLY TO MOST SUNNY SKIES ARE
EXPECTED OVER MOST OF THE CWA WITH HIGHS ONLY IN THE 30S. IT WILL BE
CLOUDIER EAST OF LAKE ONTARIO WHERE LAKE EFFECT PARAMETERS REMAIN
FAVORABLE FOR SCATTERED LAKE EFFECT SNOW SHOWERS. THE BACKING
STEERING WINDS WILL PUSH IT FARTHER NORTHWARD INTO JEFFERSON AND
LEWIS COUNTIES AND THE CHANCE WILL ALSO CONTINUE TO OSWEGO COUNTY.
NEXT SHIFT MAY HAVE TO CONSIDER RAISING POPS A BIT EAST OF LAKE
ONTARIO SUNDAY AND ADD SOME ACCUMULATIONS.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
THE SURFACE RIDGE WILL SLIDE OFF THE EAST SUNDAY NIGHT AND ALLOW ANY
LINGERING LAKE EFFECT SNOW TO END AS SUBSIDENCE AND INCREASING LOW
LEVEL SHEAR TAKE OVER.
LOW PRESSURE APPROACHING FROM THE CENTRAL GREAT LAKES WILL THEN
BRING A CHANCE OF LIGHT SNOW ON MONDAY AS WEAK ISENTROPIC LIFT
DEVELOPS AHEAD OF THIS SYSTEM. AFTER THE WEAK LOW DRIFTS OFF THE NEW
ENGLAND COAST MONDAY NIGHT...A NORTHWEST FLOW WILL SET UP ACROSS THE
LAKES AND GENERATE LIMITED LAKE EFFECT SNOW SHOWERS. ANY LINGERING
LAKE SNOWS WILL END BY TUESDAY TUESDAY AFTERNOON AS HIGH PRESSURE
BUILDS ACROSS NEW YORK STATE AND BRINGS SOME SUNSHINE TO THE AREA.
CLOUDS WILL INCREASE FROM WEST TO EAST TUESDAY NIGHT AS THE
INTENSIFYING LOW LIFTS OUT OF THE SOUTHERN ROCKIES AND MOVES INTO
THE MIDWEST. A POWERFUL LOW LEVEL JET SURGING AHEAD OF THE LOW WILL
ADVECT MOISTURE INTO PARTS OF WESTERN NEW YORK BEFORE DAYBREAK
WEDNESDAY. THE TEMPERATURES WILL BE COLD ENOUGH FOR MAINLY SNOW.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE INTENSE SURFACE LOW THAT IS FORECAST TO MOVE INTO THE MIDWEST
TUESDAY NIGHT IS STILL LOOKS LIKE IT WILL HAVE A SIGNIFICANT IMPACT
ON OUR AREA WEDNESDAY AND THURSDAY. THE GFS AND AND ECMWF TRACK THE
MAIN CENTER OF THE LOW JUST WEST OF NEW YORK STATE WEDNESDAY...WHILE
A COASTAL LOW DEVELOPS NEAR CHESAPEAKE BAY DURING THE AFTERNOON.
THE DEVELOPMENT OF THE COASTAL LOW WILL KEEP THE WARMEST LOW LEVEL
AIR TO OUR SOUTHEAST...BUT ENOUGH WARM AIR SHOULD MAY SURGE NORTH
WITH THE LOW LEVEL JET WEDNESDAY AFTERNOON TO ALLOW FOR A POSSIBLE
CHANGEOVER TO RAIN ALONG THE LAKE PLAINS. DEPENDING UPON HOW MUCH OF
A MIX OF RAIN AND SNOW THERE IS...OR IF CHANGEOVER TO RAIN DOES
OCCUR...IT LOOKS LIKE WE COULD SEE SIGNIFICANT ACCUMULATIONS OF SNOW
ON WEDNESDAY. STAY TUNED FOR LATER DETAILS.
THE OTHER FACTOR TO TAKE INTO ACCOUNT WILL BE THE WINDS ASSOCIATED
WITH THIS PATTERN. A LOOK AT THE 1.5 PVU FIELD SHOWS A DEEP
INTRUSION ASSOCIATED WITH THE MAIN SURFACE LOW AT 12Z WEDNESDAY
TRACKING OVER WESTERN TO CENTRAL NY BETWEEN 12Z AND 18Z. I LIKE TO
USE THE LEADING GRADIENT OF THIS PV INTRUSION TO TIME THE ONSET OF
GUSTY WINDS AND THE POTENTIAL FOR CONVECTION. THIS PV INTRUSION IS
ALSO COINCIDENT WITH A 6-HOUR DROP OF 13-16 MILLIBARS DURING THE
SAME TIMEFRAME...BOTH PARAMETERS POINTING TO A VERY WINDY DAY FOR
WEDNESDAY.
AS THE LOW TRACKS NORTH OF LAKE ONTARIO WEDNESDAY NIGHT AND
THURSDAY...MUCH COLDER AIR WILL SURGE IN BEHIND THE LOW AND GENERATE
VERY WINDY CONDITIONS AND MORE SYNOPTIC AND LAKE ENHANCED SNOW.
THE MAIN CENTER OF THE LOW IS FORECAST TO MOVE TO THE GULF OF SAINT
LAWRENCE DURING THURSDAY NIGHT AND ONWARD TO LABRADOR ON
FRIDAY...WHILE HIGH PRESSURE BUILDS INTO THE MIDDLE ATLANTIC STATES.
THE COLD NORTHWEST FLOW BETWEEN THESE TWO SYSTEMS WILL GENERATE
LAKE EFFECT SNOW THURSDAY THROUGH FRIDAY.
ANOTHER...MUCH WEAKER LOW WILL BRING A CHANCE OF SNOW ON SATURDAY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
SOME LAKE EFFECT SNOW SHOWERS WILL CONTINUE THROUGH THE FIRST
PORTION OF THE TAF PERIOD EAST OF LAKE ERIE THAT WILL BRING MVFR
CONDITIONS ACROSS THE SOUTHERN TIER. MVFR CIGS SHLD IMPROVE TO VFR
CONDITIONS LATER THIS AFTERNOON ACROSS THIS REGION. ACROSS THE
NIAGARA FRONTIER AND THE GENESEE VALLEY GENLY VFR CONDITIONS ARE
EXPECTED THROUGH THE TAF PERIOD.
SOME LAKE EFFECT SNOW SHWRS EARLY THIS MORNING SOUTHEAST OF LAKE
ONTARIO SHLD BE TO THE EAST OF ROCHESTER TO AROUND THE KFZY REGION.
DURING THE COURSE OF THE DAY THE LAKE SNOWS SHLD MOVE NORTH TO AREAS
EAST OF LK ONTARIO BUT THE ACTIVITY SHLD STAY TO THE SOUTH OF
WATERTOWN. SOME MVFR/IFR CONDITIONS CAN BE EXPECTED IN THE LK SNOWS WHEN
THEY MOVE INTO THE TUG HILL REGION BY MIDDAY. SOEM MVFR CIGS COULD
MAKE IT TO KART DURG THE COURSE OF THE AFTERNOON.
OUTLOOK...
MONDAY...VFR/MVFR WITH A CHANCE OF SNOW.
TUESDAY...VFR.
WEDNESDAY...MVFR/IFR WITH RAIN/SNOW. PSBL LOW LEVEL WIND SHEAR.
THURSDAY...MVFR/IFR SNOW SHOWERS. STRONG SURFACE WINDS LIKELY.
&&
.MARINE...
SOUTHWEST TO WESTERLY WINDS WILL INCREASE AGAIN ON SUNDAY WITH
SMALL CRAFT ADVISORIES. DURING MIDWEEK...A STRONG WINTER STORM WILL
LIKELY GENERATE GALES ON THE LAKES WEDNESDAY AND THURSDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 1 AM EST
MONDAY FOR LOZ042-043.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 6 AM EST
MONDAY FOR LOZ045.
SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 5 AM EST
MONDAY FOR LOZ044.
&&
$$
SYNOPSIS...TJP
NEAR TERM...JJP/SAGE
SHORT TERM...TJP
LONG TERM...TJP/WCH
AVIATION...JJP/TJP
MARINE...TJP
