Area Forecast Discussion
Issued by NWS Buffalo, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS61 KBUF 240032
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
732 PM EST SUN NOV 23 2014

.SYNOPSIS...
TEMPERATURES WILL WARM FURTHER TONIGHT WITH MORE RAIN AS A WARM
FRONT LIFTS NORTH OUT OF THE OHIO VALLEY. THE WARMING TEMPERATURES
AND RAINFALL COMBINED WITH INCREASINGLY STRONG WINDS TONIGHT AND
ESPECIALLY MONDAY THROUGH MONDAY NIGHT WILL ACCELERATE MELTING OF
RECENT HEAVY SNOWS...CREATING A SIGNIFICANT FLOODING RISK ACROSS
PORTIONS OF WESTERN NEW YORK. A STRONG COLD FRONT WILL CROSS THE
REGION MONDAY EVENING...BRINGING A RETURN OF MORE WINTER-LIKE
TEMPERATURES AND A CHANCE OF SNOW BY LATER IN THE WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
THE WARMING TREND WILL CONTINUE THROUGH TONIGHT AS INCREASINGLY WARM
AIR SURGES NORTH ACROSS THE REGION AS A WARM FRONT LIFTS NORTHWARDS
ON THE NOSE OF A 60 TO 70 KNOT LOW LEVEL JET. A STRONG TEMPERATURE
INVERSION ASSOCIATED WITH THIS WARM ADVECTION WILL LIKELY PROTECT
MUCH OF THE FORECAST AREA FROM THE STRONG WINDS ALOFT...HOWEVER WITH
THE LOWER LEVELS OF THE ATMOSPHERE SHOWING SOUTH-SOUTHEASTERLY
ORIENTATION TO THE FLOW AND THE INVERSION SETTING UP NEAR THE
CHAUTAUQUA RIDGE...CONDITIONS ARE FAVORABLE FOR STRONG DOWNSLOPING
WINDS ALONG THE LAKE ERIE SHORELINE...WHERE A WIND ADVISORY REMAINS
IN EFFECT TONIGHT THROUGH MONDAY MORNING.

ISENTROPIC ASCENT ALONG THE WARM FRONTAL ZONE WILL BRING THE
DEVELOPMENT OF WIDESPREAD RAINFALL ACROSS THE REGION AS DEEP LAYERED
MOISTURE IS FOCUSED INTO THE REGION ON THE NOSE OF THE STRONG LOW
LEVEL JET. DOWNSLOPING SHOULD DIMINISH RAINFALL AMOUNTS ACROSS FAR
WESTERN NEW YORK...KEEPING THOSE AMOUNTS TO AROUND A QUARTER OF AN
INCH...WITH SLIGHTLY HIGHER AMOUNTS POSSIBLE ELSEWHERE. DESPITE THE
LIMITED RAINFALL THREAT...THE IMMENSE VOLUME OF WATER FROM THE
SNOWMELT ACROSS PORTIONS OF WESTERN NEW YORK WILL CREATE A
PERSISTENT FLOOD THREAT...PARTICULARLY ALONG THE BUFFALO CREEKS AND
AREAS WITH POOR DRAINAGE...ESPECIALLY TONIGHT INTO MONDAY.

MORE WARMING EXPECTED MONDAY AHEAD OF APPROACHING COLD FRONTAL
BOUNDARY. TEMPERATURES LIKELY PEAKING IN THE MID 50S TO LOWER 60S.
BRIEF SUBSIDENCE SUGGESTS A DIMINISHING TREND TO THE SHOWERS...
BEFORE AN INBOUND MID LEVEL WAVE WORKS ACROSS THE REGION DURING THE
MID TO LATE AFTERNOON. STRONG SIGNAL OF FRONTAL CONVERGENCE TUCKED
BENEATH FAVORABLE UPPER JET DYNAMICS SHOULD ALLOW SHOWER COVERAGE TO
INCREASE AGAIN LATER IN THE DAY.

THE MAIN FORECAST ELEMENT OF CONCERN REMAINS THE WIND POTENTIAL AS
STRONG COLD AIR ADVECTION ENSUES BY THE EVENING HOURS. STRONG
POST-FRONTAL SOUTHWEST GRADIENT TAKES HOLD DURING THIS TIME. GUST
POTENTIAL WILL CAPITALIZE ON A PERIOD OF STRONG 280-285K ISENTROPIC
DESCENT AND AN INCREASING MIXING POTENTIAL AS LAPSE RATES STEEPEN
WITH THE ADVECTIVE PROCESS. RECENT GUIDANCE MAINTAINS WIND SPEEDS IN
THE 50 TO 60 KNOT RANGE AT 925 MB. THIS WOULD INDICATE GUSTS TO 60
MPH DOWNWIND OF LAKE ERIE WITH 50 TO 55 MPH GUSTS ELSEWHERE.
GREATEST GUSTS LOOK TO BE CENTERED FROM 21Z AND INTO THE FIRST HALF
OF MONDAY NIGHT.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS THIS PERIOD OPENS...DEEP LOW PRESSURE NEAR JAMES BAY WILL FINISH
PUSHING ITS TRAILING COLD FRONT ACROSS THE AREA EARLY IN THE
EVENING. THIS BOUNDARY MAY BE ACCOMPANIED BY A BROKEN/NARROW BAND OF
SHOWERS AS IT CLEARS THE FINGER LAKES AND NORTH COUNTRY...WITH
STRONG DRY SLOTTING IN ITS WAKE THEN GENERALLY BRINGING DRY WEATHER
FOR THE BALANCE OF THE NIGHT IN MOST AREAS. THE POSSIBLE EXCEPTIONS
TO THIS WILL BE IN AREAS DOWNWIND OF THE LAKES...WHERE THE
COMBINATION OF SOMEWHAT BETTER LOW LEVEL MOISTURE AND THE PREVAILING
CYCLONIC LARGE-SCALE FLOW COULD HELP TO GENERATE A FEW ADDITIONAL
RAIN AND SNOW SHOWERS. WHILE THE LAKES SHOULD DEFINITELY CONTRIBUTE
SOME MOISTURE TO HELP THESE ALONG...THESE WILL NOT BE TRULY LAKE
EFFECT IN NATURE GIVEN THAT 850 MB TEMPS WILL ONLY FALL TO -5C/-6C
BY LATE IN THE NIGHT...OR LEVELS THAT ARE NOT COLD ENOUGH FOR A PURE
LAKE RESPONSE.

OF MUCH GREATER CONCERN MONDAY NIGHT WILL BE THE LIKELIHOOD FOR
STRONG WINDS. IN THE WAKE OF THE COLD FRONTAL PASSAGE...A STRONG LOW
LEVEL JET WILL REMAIN IN PLACE ALOFT WITH 925 MB WINDS AS HIGH AS
55-60 KNOTS AND 850 MB WINDS AS HIGH AS 65-70 KNOTS...AND STRONG
COLD AIR ADVECTION SHOULD HELP TO AT LEAST PARTIALLY MIX THESE DOWN
TO THE SURFACE. GIVEN THE EXPECTED SOUTHWEST FLOW REGIME AND THE
USUAL FUNNELING EFFECTS...THIS WILL LIKELY LEAD TO SOME WARNING-
CRITERIA WIND GUSTS FROM CHAUTAUQUA COUNTY NORTHEASTWARD ACROSS THE
NIAGARA FRONTIER TO THE ROCHESTER AREA...WITH SIMILAR GUSTS ALSO
POSSIBLE /THOUGH NOT AS QUITE A SURE THING/ ACROSS THE NORTH
COUNTRY. ELSEWHERE THE WIND GUSTS SHOULD NOT BE QUITE AS STRONG...
THOUGH THESE WILL PROBABLY STILL REACH ADVISORY LEVELS.

WITH ALL OF THE ABOVE IN MIND...A HIGH WIND WARNING WILL CONTINUE
THROUGH MUCH OF THE NIGHT FOR THE FAVORED AREAS DOWNWIND OF LAKE
ERIE...WHILE A HIGH WIND WATCH WILL BE IN PLACE EAST OF LAKE
ONTARIO...AND A WIND ADVISORY WILL BE IN EFFECT ELSEWHERE. EXPECT
THE STRONGEST OVERALL WINDS TO BE IMMEDIATELY DOWNWIND OF LAKE
ERIE...WHERE SATURATED GROUND CONDITIONS IN THE WAKE OF THE ONGOING
MASSIVE SNOWMELT WILL LEAD TO AN ENHANCED POTENTIAL FOR DOWNED TREES
AND POWER OUTAGES...WHICH WILL BE A MAJOR CONCERN FOR THOSE HOPING
TO KEEP THEIR BASEMENTS DRY.

ON TUESDAY...THE WINDS WILL GRADUALLY RELAX THROUGH THE COURSE OF
THE DAY AS THE LOW LEVEL JET WEAKENS/DEPARTS OUR REGION AND THE
OVERALL PRESSURE GRADIENT RELAXES...THOUGH IT WILL STILL BE FAIRLY
BREEZY TO WINDY RIGHT THROUGH THE DAY WITH SOME LINGERING
ADVISORY-TYPE GUSTS STILL POSSIBLE EARLY. IN TERMS OF PRECIP
CHANCES...THE COMBINATION OF CONTINUED MODEST COLD AIR ADVECTION
AND INCREASING MOISTURE IN ADVANCE OF A SECONDARY SURFACE TROUGH
SHOULD HELP TO FUEL THE DEVELOPMENT OF SOME MODEST LAKE EFFECT SNOW
AND RAIN SHOWER ACTIVITY NORTHEAST OF THE LAKES...THOUGH THIS IS
LIKELY TO REMAIN FAIRLY MODEST IN EXTENT DUE TO EXPECTED MARGINAL
TEMPERATURE PROFILES AND LAKE INDUCED EQLS IN THE 5-7 KFT RANGE. AS
A RESULT...ANY SNOWFALL ACCUMS SHOULD REMAIN OF THE NUISANCE-TYPE
VARIETY. OUTSIDE OF THE MAIN LAKE EFFECT AREAS...CONDITIONS SHOULD
REMAIN LARGELY DRY.

ADDITIONAL NUISANCE-TYPE LAKE EFFECT SNOW SHOWERS SHOULD THEN
CONTINUE INTO TUESDAY NIGHT EAST-NORTHEAST OF THE LAKES...BEFORE
GRADUALLY WINDING DOWN OVERNIGHT AND WEDNESDAY MORNING AS HIGH
PRESSURE AND ATTENDANT SUBSIDENCE/DRIER AIR BUILDS INTO THE
REGION...WHILE ALSO FORCING THE LOW LEVEL WIND FIELD TO BECOME
LIGHTER/INCREASINGLY SHEARED. BY MIDDAY WEDNESDAY...EXPECT THIS
ACTIVITY TO EITHER END ALTOGETHER OR BE PUSHED OUT OF OUR AREA AS
THE LOW LEVEL FLOW BACKS TO AN UNFAVORABLE ORIENTATION FOR LAKE
EFFECT ACROSS WESTERN AND NORTH CENTRAL NEW YORK.

FOLLOWING THE END OF THE LAKE EFFECT...OUR ATTENTION WILL TURN TO A
DEVELOPING COASTAL SYSTEM THAT WILL BE IN THE PROCESS OF LIFTING
NORTHEASTWARD ALONG THE ATLANTIC COASTLINE. BOTH THE GFS/ECMWF ARE
TRENDING MORE AND MORE DEVELOPED WITH THIS SYSTEM...WHICH COULD
ULTIMATELY PRODUCE A PRE-THANKSGIVING SNOWSTORM ACROSS PORTIONS OF
EASTERN NEW YORK AND NEW ENGLAND. MEANWHILE FURTHER WEST...IT
APPEARS THAT OUR REGION WILL BE MORE ON THE WESTERN FRINGES OF THIS
SYSTEM AND THUS SUBJECT TO MUCH LIGHTER PRECIP...THOUGH THE EXACT
WESTERN EDGE OF THE PRECIP SHIELD REMAINS VERY MUCH IN QUESTION AT
THIS PARTICULAR TIME. TAKING BOTH THE ABOVE MENTIONED MODEL TRENDS
AND ALSO THE LINGERING UNCERTAINTY INTO CONSIDERATION...FOR NOW HAVE
ELECTED TO INTRODUCE A CHANCE OF SNOW FOR OUR AREA WEDNESDAY
AFTERNOON AND WEDNESDAY NIGHT...WITH THE HIGHEST CHANCES OF THIS
FOUND ALONG OUR EASTERN PERIPHERY.

AS FOR TEMPS...THESE WILL AGAIN FALL BACK TO BELOW NORMAL LEVELS
FOLLOWING MONDAY EVENING`S FRONTAL PASSAGE...THEN WILL REMAIN THERE
THROUGH THE BALANCE OF THE PERIOD.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
IN THE WAKE OF THE DEPARTING COASTAL SYSTEM...A FRESH SHOT OF MUCH
COLDER AIR WILL OVERSPREAD THE LOWER LAKES REGION THURSDAY AND
THURSDAY NIGHT...WHICH IN CONJUNCTION WITH LINGERING SYNOPTIC-SCALE
MOISTURE WILL HELP SET THE STAGE FOR ANOTHER POSSIBLE ROUND OF LAKE
EFFECT SNOW. AT THIS POINT...IT APPEARS THAT THE LARGE-SCALE FLOW
WILL LARGELY BE WESTERLY OR PERHAPS EVEN A BIT WEST-NORTHWESTERLY IN
NATURE...WHICH WOULD FAVOR THE MORE TRADITIONAL SNOW BELTS EAST AND
EAST-SOUTHEAST OF THE LAKES. ELSEWHERE...EXPECT JUST A GENERAL
CHANCE OF SNOW SHOWERS GIVEN THE LARGE-SCALE COLD CYCLONIC FLOW.

ON FRIDAY...BUILDING SURFACE-BASED RIDGING SHOULD FORCE ANY LAKE
EFFECT SNOW/SNOW SHOWERS TO DRAMATICALLY WEAKEN AND LIFT NORTHWARD
AS THE STEERING WINDS BACK AGAIN...WITH AREAS OUTSIDE OF ANY LAKE
INFLUENCES LIKELY TO REMAIN DRY. AFTER THAT...THINGS GET MUCH MORE
UNCERTAIN FOR NEXT WEEKEND WITH THE VARIOUS GUIDANCE PACKAGES
FLOPPING AROUND BETWEEN TWO GENERAL IDEAS...ONE OF WHICH SUGGESTS A
STRONG LOW LIFTING ACROSS THE GREAT LAKES AND PROVIDING OUR AREA A
STRONG WARMUP AT SOME POINT...AND THE OTHER INDICATING A MUCH WEAKER
TROUGH PASSAGE FOLLOWED BY ANOTHER SHOT OF MUCH COLDER AIR/MORE LAKE
EFFECT POTENTIAL. GIVEN THE DISTANT TIME FRAME...OUR PREVIOUS
CONTINUITY AND WPC PREFERENCES...HAVE ELECTED TO FOLLOW ALONG WITH
THE LATTER SCENARIO FOR NOW.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
AN AREA OF LIGHT SHOWERS WILL CONTINUE TO LIFT NORTHWARD ACROSS THE
AREA THIS AFTERNOON AHEAD OF APPROACHING WARM FRONT. PATCHY MVFR
CONDITIONS WITH THE SHOWER ACTIVITY WILL BECOME VFR AS THE
SHOWERS END AND THE WARM FRONT LIFTS ACROSS THE AREA.

LATER THIS EVENING...A STRENGTHENING LOW LEVEL JET AHEAD OF A
RAPIDLY DEEPENING LOW PRESSURE SYSTEM OVER THE CENTRAL MS VALLEY
WILL LEAD TO STRONG DOWNSLOPING WINDS AND LOCALIZED TURBULENCE ALONG
THE LAKE ERIE SHORELINE WITH LLWS DEVELOPING ELSEWHERE AS A STRONG
LLJ MOVES OVERHEAD IN ADVANCE OF THE AFOREMENTIONED LOW. THE NOSE OF
THIS JET WILL ALSO MARK THE LEADING A BROADER AREA OF RAINFALL
PROGGED TO MOVE INTO THE FORECAST AREA AFTER 06Z...BRINGING MVFR
CONDITIONS.

OUTLOOK...
MONDAY AND MONDAY NIGHT...VFR/MVFR WITH SHOWERS. VERY WINDY.
TUESDAY...MAINLY VFR WITH A CHANCE OF RAIN/SNOW SHOWERS.
WEDNESDAY AND THURSDAY...MAINLY VFR/MVFR EXCEPT IFR POSSIBLE IN LAKE
EFFECT SNOW SHOWERS EAST OF BOTH LAKES.

&&

.MARINE...
SOUTH WINDS GENERALLY UNDER 15 KNOTS THROUGH THE AFTERNOON. BY
THIS EVENING...SOUTH-SOUTHEASTERLY WINDS WILL FRESHEN ON LAKE
ERIE AS A WARM FRONT LIFTS NORTH ACROSS THE REGION AHEAD OF A
RAPIDLY DEEPENING LOW PRESSURE SYSTEM THAT WILL TRACK FROM THE
CENTRAL MISSISSIPPI VALLEY ACROSS THE WESTERN GREAT LAKES. THESE
SOUTHEASTERLY WINDS WILL AFFECT THE LAKE ERIE NEARSHORE WATERS...
LEADING TO ANOTHER ROUND OF SMALL CRAFT ADVISORIES FROM BUFFALO TO
RIPLEY TONIGHT.

THIS LOW WILL CONTINUE TO INTENSIFY AS IT CROSSES THE OTTAWA VALLEY
AND MOVES INTO QUEBEC MONDAY EVENING WHILE SWINGING A STRONG COLD
FRONT ACROSS THE LOWER GREAT LAKES. GALES WILL DEVELOP ON BOTH
EASTERN LAKE ERIE AND LAKE ONTARIO FROM MONDAY THROUGH TUESDAY DUE
TO THE VERY STRONG WIND FIELDS ACCOMPANYING THIS DEEP LOW.

GALES WILL SUBSIDE LATER ON TUESDAY AS THE LOW PRESSURE SYSTEM
RESPONSIBLE TRACKS OFF TO THE NORTHEAST ACROSS LABRADOR. A WEAK
AREA OF HIGH PRESSURE IS THEN EXPECTED TO SKIRT THE LAKES WITH
LIGHTER WINDS EXPECTED FOR THE MIDDLE PORTION OF THE WEEK BEFORE
NORTHERLY WINDS FRESHEN THURSDAY NIGHT AS A DEEPENING COASTAL LOW
TRACKS UP THE EASTERN SEABOARD.

&&

.HYDROLOGY...
A SNOW SURVEY COMPLETED ON FRIDAY CAME UP WITH A GENERAL 4 TO 6
INCHES OF SNOW WATER EQUIVALENT IN THE HARDEST HIT LAKE EFFECT
SNOW AREAS.

TEMPERATURES WILL REMAIN VERY MILD TONIGHT AND ONLY FALL INTO THE
MID 40S...BEFORE RISING INTO THE 60S ON MONDAY. DEW POINTS ACROSS
THE REGION ARE ABOVE 32 AND WILL CONTINUE TO STEADILY RISE INTO
THE UPPER 40S TO AROUND 50 BY TONIGHT AND MONDAY. THE HIGHER
DEWPOINTS COMBINED WITH STRONG WINDS WILL BE VERY EFFICIENT AT
RAPIDLY MELTING THE DEEP SNOW PACK. THIS...ALONG WITH RAINFALL
AMOUNTS OF GENERALLY UNDER A QUARTER INCH THROUGH TONIGHT...WILL
RESULT IN SIGNIFICANT RISES ON LOCAL TRIBUTARIES WITH AREAL
FLOODING EXPECTED FOR THE AREAS IN FAR WESTERN NEW YORK THAT
RECEIVED THE TWO LAKE EFFECT SNOW STORMS THIS PAST WEEK.

THE FLOOD POTENTIAL WILL BE TWO FOLD. FIRST...THERE IS A GENERAL
RISK OF URBAN FLOODING IN THE TOWNS HARDEST HIT BY THE SNOW AS
MELT WATER POOLS IN LOW LYING AND POOR DRAINAGE AREAS. EXCESSIVE
SNOW PILES AND LEAVES BENEATH THE SNOW MAY BLOCK STORM DRAINS.
FLOODING OF SOME STREETS AND RESIDENTIAL BASEMENTS COULD BEGIN
ANYTIME NOW WITH MELTING UNDER WAY....SO AN AREAL FLOOD WARNING
CONTINUES THROUGH AT LEAST MONDAY AFTERNOON TO ADDRESS THIS
THREAT.

THERE WILL ALSO BE THE RISK FOR THE FLOODING OF THE VARIOUS
CREEKS AND TRIBUTARIES ACROSS FAR WESTERN NEW YORK. THE GREATEST
THREAT IS ON THE BUFFALO CREEKS WHICH DRAIN THE HARDEST HIT AREAS
FROM THIS WEEKS LAKE EFFECT SNOW. THIS INCLUDES
CAZENOVIA...BUFFALO... CAYUGA...AND ELLICOTT. INDIVIDUAL FLOOD
WARNINGS FOR THESE CREEKS HAVE BEEN ISSUED...AS ALL ARE NOW
FORECAST TO REACH AT LEAST MINOR FLOOD LEVELS. THERE MAY ALSO BE
SOME FLOOD RISK FOR CATTARAUGUS CREEK AND SOME OF THE SMALLER
CREEKS THAT FLOW THROUGH DUNKIRK AND SILVER CREEK.

THERE IS ALSO A FAIRLY HEAVY SNOW PACK IN THE UPPER REACHES OF THE
OATKA WATERSHED...BUT NOT AS HIGH AS THE BUFFALO CREEKS. WE WILL
CONTINUE TO MONITOR THIS BASIN FOR POSSIBLE FUTURE INCLUSION IN
A FLOOD WARNING IF WE SEE STEADY RISES. THE EASTERN LAKE ONTARIO
REGION HAD LESS SNOW... WITH TOTALS OF 2 TO 2.5 FEET ON THE TUG
HILL. THIS SNOW PACK IS NOT EXCESSIVE FOR THAT AREA...SO HAVE NOT
INCLUDED THE NORTH COUNTRY IN A FLOOD WATCH AT THIS TIME.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...HIGH WIND WARNING FROM 1 PM MONDAY TO 4 AM EST TUESDAY FOR
     NYZ001>003-010>012-019-085.
     WIND ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST MONDAY FOR
     NYZ019-085.
     LAKESHORE FLOOD WATCH FROM MONDAY AFTERNOON THROUGH LATE
     TUESDAY NIGHT FOR NYZ010-019-085.
     HIGH WIND WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY
     NIGHT FOR NYZ006>008.
     WIND ADVISORY FROM 1 PM MONDAY TO 4 AM EST TUESDAY FOR NYZ004-
     005-013-014-020-021.
MARINE...GALE WARNING FROM 1 PM MONDAY TO 7 PM EST TUESDAY FOR LEZ020-
         040-041.
         SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST
         MONDAY FOR LEZ040-041.
         GALE WARNING FROM 1 PM MONDAY TO 7 PM EST TUESDAY FOR
         LOZ030-042-062.
         GALE WARNING FROM 4 PM MONDAY TO 7 PM EST TUESDAY FOR
         LOZ043>045-063>065.
         SMALL CRAFT ADVISORY FROM 10 AM MONDAY TO 7 AM EST
         TUESDAY FOR SLZ022-024.

&&

$$

SYNOPSIS...TMA
NEAR TERM...TMA/WCH
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...TMA/WCH
MARINE...TMA
HYDROLOGY...HITCHCOCK/RSH/SMITH







USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.