Area Forecast Discussion
Issued by NWS Buffalo, NY

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FXUS61 KBUF 020543
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
143 AM EDT THU APR 2 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH ACROSS THE LOWER GREAT LAKES OVERNIGHT
BRINGING A CHANCE OF A WINTRY MIX EAST OF LAKE ONTARIO BUT
OTHERWISE DRY WEATHER ELSEWHERE. INCREASING SOUTHERLY FLOW
THURSDAY WILL PUSH TEMPERATURES WELL ABOVE NORMAL. A COLD FRONT
WILL APPROACH THURSDAY EVENING BRINGING RAIN SHOWERS AND A CHANCE
OF THUNDERSTORMS WITH GUSTY WINDS. THE POTENTIAL FOR UNSETTLED
WEATHER WITH RAIN AND SNOW AT TIMES REMAINS THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
HIGH CLOUDS WILL INCREASE FROM THE NORTHWEST AND GRADUALLY LOWER
INTO A MID-DECK OVERNIGHT HOWEVER AS THE HIGH SLIDES OFF TO THE
SOUTHEAST AND A WARM FRONT CROSSES THE REGION. WHILE THE STRONGEST
ISENTROPIC UPLIFT AND DEEPER MOISTURE IS PROGGED TO REMAIN TO OUR
NORTHWEST ACROSS EASTERN ONTARIO...THERE REMAINS A
POSSIBILITY...SUPPORTED BY THE BULK OF MODEL GUIDANCE...THAT THE
SOUTHERN EDGE OF THIS ZONE OF GREATER MOISTURE AND LIFT WILL CLIP
THE NORTH COUNTRY LATE TONIGHT AS THE FRONT MOVES THROUGH. AS SUCH
HAVE LEFT THE CHANCE POPS IN PLACE ACROSS THE NORTH COUNTRY...BUT
HAVE ELIMINATED THEM ALONG THE THRUWAY CORRIDOR EAST OF ROCHESTER
AS THIS LIMITED MOISTURE WILL LIKELY BE UNABLE TO OVERCOME THE
VERY DRY LOW-LEVEL AIR CURRENTLY IN PLACE. EVEN IN THE NORTH
COUNTRY...ANY PRECIP THAT MAKES IT TO THE GROUND WILL BE VERY
LIGHT.

REGARDING PRECIP TYPE...TEMPERATURES SHOULD ONLY FALL A FEW MORE
DEGREES AT MOST THIS EVENING BEFORE WARM AIR ADVECTION KICKS IN
OVERNIGHT AS THE AFOREMENTIONED WARM FRONT MOVES THROUGH. WHILE
THERE IS A POTENTIAL THAT THE ISOLATED PRECIP ACROSS THE NORTH
COUNTRY MAY INITIALLY BEGIN AS A WINTRY MIX...IT WILL LIKELY BE VERY
LIGHT AND SHOULD CHANGE OVER TO RAIN WITHIN AN HOUR OR TWO AS
TEMPERATURES WARM ABOVE FREEZING. WITH THAT IN MIND...LOOK FOR LATE
EVENING LOWS RANGING FROM THE MID 30S IN WESTERN NEW YORK TO THE MID
TO UPPER 20S IN THE NORTH COUNTRY BEFORE TEMPERATURES WARM INTO THE
30S IN THE NORTH COUNTRY WITH LOWER 40S ACROSS FAR WESTERN NEW YORK
BY DAYBREAK.

CONTINUED WARM ADVECTION THURSDAY WILL HELP BOOST SURFACE
TEMPERATURES INTO THE LOW TO MID 60S FOR MOST OF WESTERN NEW YORK
WITH U50S FOR THE NORTH COUNTY. THESE NUMBERS WILL BE THE WARMEST WE
HAVE SEEN SO FAR THIS YEAR. THE SOUTHERLY WINDS WILL DOWNSLOPE FROM
THE HIGHER TERRAIN OF THE SOUTHERN TIER AND ADD AN ADDITIONAL BOOST
TO TEMPERATURES IN THE GENESEE VALLEY AND ALONG THE LAKE ONTARIO
LAKE SHORES WHERE READINGS MAY REACH INTO THE UPPER 60S. THIS MAY
ALSO OCCUR ALONG PORTIONS OF THE LAKE ERIE SHORELINE AS LONG AS THE
WINDS STAY AROUND 180/190. IF WINDS VEER TO SOUTHWEST THEN THE ICY
TEMPERATURES OVER LAKE ERIE WILL PREVENT TEMPERATURES IN METRO
BUFFALO FROM REACHING 60. A TIGHTENING PRESSURE GRADIENT WILL BRING
INCREASING WINDS INTO THE AFTERNOON WITH GUSTS 20-30 MPH. A COLD
FRONT WILL APPROACH WESTERN NEW YORK IN THE AFTERNOON WITH MESOSCALE
MODELS HINTING AT SOME PRE-FRONTAL SHOWERS SHIFTING INTO THE
SOUTHERN TIER THEN NORTH ACROSS WESTERN NEW YORK TOWARD THE EVENING
HOURS. THERE IS A CHANCE FOR SOME THUNDERSTORMS IF ANY ELEVATED
CONVECTION GETS GOING AHEAD OF THE COLD FRONT. OTHERWISE...SURFACE
BASED CAPE AND LIFTED INDEX VALUES ARE TOO WEAK FOR ANY SURFACE
BASED STORMS.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
MODEL GUIDANCE CONTINUES TO BE IN EXCELLENT AGREEMENT THAT A LINE OF
SHOWERS WILL MOVE ACROSS THE REGION ON THURSDAY EVENING.
HOWEVER...GUIDANCE HAS TRENDED WEAKER WITH THE SURFACE FRONT AND
INSTEAD KEEPS THE COLDER AIR BEHIND A SECONDARY FRONTAL BOUNDARY
WHICH WILL REMAIN UPSTREAM. THERE IS STILL AMPLE LIFT ALONG THE AXIS
OF A 60 TO 70 KT LLJ WHICH IS AHEAD OF A SHORTWAVE. NAM/GFS/SREF/RGEM
CONSENSUS QPF IS BETWEEN A QUARTER AND HALF INCH...WITH LOCALLY
HIGHER AMOUNTS. MODEL CONSENSUS AND THE SYNOPTIC NATURE OF THE
FEATURE PROVIDES GOOD FORECAST CONFIDENCE.

THE LLJ WILL WARM MID-LEVELS AND RESULT IN MODEST ELEVATED CAPE
WHICH MAY SPARK A FEW EMBEDDED THUNDERSTORMS. OTHERWISE...SURFACE
TEMPERATURES WILL REMAIN ON THE WARM SIDE THURSDAY EVENING AND ONLY
DROP MODESTLY WITH THE FRONTAL PASSAGE. WITH DEW POINTS WELL INTO
THE 40S THERE MAY BE SOME STRATUS OR FOG NEAR THE LAKES ONCE WINDS
DIMINISH BEHIND THE DISTURBANCE.

CONSENSUS 12Z GUIDANCE PUSHES THE FRONT A BIT FURTHER SOUTH WITH IT
NOW LIKELY TO DROP INTO PA FRIDAY MORNING. THERE IS STILL A SMALL
CHANCE FOR SHOWERS ACROSS THE SOUTHERN TIER...BUT THIS SHOULD ALLOW
FOR SOME SUN ELSEWHERE WHICH WILL ALLOW TEMPERATURES TO WARM QUITE
NICELY ON FRIDAY. THE WEAK FLOW WILL LEAVE US VULNERABLE TO LAKE
BREEZE DEVELOPMENT...WITH HIGHS LIKELY TO BE COOLER NEAR THE
IMMEDIATE LAKESHORES. INLAND...HIGHS SHOULD AGAIN CLIMB WELL INTO
THE 50S...WITH A FEW SPOTS REACHING 60 WITH AMPLE SUN.

A PROGRESSIVE TROUGH IS FORECAST TO MOVE ACROSS THE STALLED BOUNDARY
FRIDAY NIGHT...WITH A WEAK BUT MOIST WAVE OF LOW PRESSURE FORECAST
TO TRACK ALONG THE BOUNDARY. IN ADDITION TO THE SURFACE WAVE...THE
REGION WILL BE IN THE FAVORABLE LEFT FRONT QUADRANT OF THE JET
STREAM WHICH ALSO SHOULD ENHANCE LIFT. THE BIG QUESTION FOR THIS
SYSTEM IS IF TEMPERATURES WILL COOL QUICKLY FOR SIGNIFICANT SNOW
ACCUMULATION. BASED ON 12Z GUIDANCE IT NOW APPEARS LESS LIKELY THAT
THIS WILL HAPPEN...WITH THE MAJORITY OF QPF LIKELY TO COME BEFORE
BOUNDARY LAYER TEMPERATURES COOL ENOUGH TO SUPPORT SNOW. THE
OVERNIGHT TIMING SHOULD RENDER THE APRIL SUN ANGLE MOOT. THIS DOES
NOT MEAN WE ARE OUT OF THE WOODS...WITH ACCUMULATIONS OF 1 TO 3
INCHES LIKELY TO FOCUS ACROSS HIGHER TERRAIN. IT IS STILL A COULD
DAYS OFF...SO THERE IS A POTENTIAL THAT LATER RUNS WILL BRING MORE
COLD AIR WITH THE INITIAL FRONT OR TREND STRONGER WITH THE
SYSTEM...BOTH OF WHICH COULD POTENTIALLY INCREASE THESE AMOUNTS.

THE WAVE WILL EXIT INTO THE CANADIAN MARITIMES ON SATURDAY WITH
SYNOPTIC PRECIPITATION EXPECTED TO TAPER OFF RATHER QUICKLY. COLDER
AIR WILL ADVECT INTO THE REGION...WHICH MAY PROMOTE A VERY LIMITED
LAKE RESPONSE. MEANWHILE TEMPERATURES WILL BE BELOW NORMAL WITH
HIGHS ONLY IN THE 30S ON SATURDAY.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
A WEAK COLD FRONT IS FORECAST TO DROP SOUTHWARD INTO THE REGION
SATURDAY NIGHT WHICH MAY BRING A FEW SNOW SHOWERS. AFTER THIS...THIS
FRONTAL BOUNDARY IS FORECAST TO STALL AND STRENGTHEN. THE
TEMPERATURE DIFFERENCE WILL INITIALLY BE MODEST...BUT BY TUESDAY OF
NEXT WEEK TEMPERATURES ON THE WARM SIDE WILL BE IN THE 60S AND THE
COOL SIDE ONLY IN THE 30S. FORECAST WILL USE A WEIGHTED CONSENSUS OF
RECENT RUNS OF THE ECMWF/GFS/GGEM FOR THE POSITION OF THE FRONT. IN
GENERAL...THE BEST CHANCE FOR THE FRONT TO BE OUR SOUTH (PUTTING US
ON THE COOL SIDE) IS ON SUNDAY. AFTER THIS THE FRONT IS LIKELY TO
MEANDER NORTHWARD WITH AN INCREASING CHANCE OF WARMING TEMPERATURES
ON MONDAY AND TUESDAY. A WAVE OF LOW PRESSURE IS LIKELY TO DEVELOP
ON THE FRONT IN THE TUESDAY TIMEFRAME WHICH WOULD BRING AN
INCREASING CHANCE OF PRECIPITATION LATE TUESDAY FOLLOWED BY COOLER
TEMPERATURES WEDNESDAY. OTHERWISE...THERE WILL BE A PERSISTENT LOW
CHANCE FOR RAIN (OR POSSIBLY SNOW SHOWERS NORTH) DEPENDING WHERE
THIS BOUNDARY SETTLES.

FORECAST CONFIDENCE IN THIS GENERAL PATTERN IS QUITE HIGH...WITH
NEARLY ALL LONG-TERM GUIDANCE FORECASTING SOMETHING SIMILAR. HOWEVER
WHEN IT COMES TO SPECIFICS FOR OUR FORECAST CONFIDENCE IS
LOW...ESPECIALLY FOR TEMPERATURES. TEMPERATURES MAY BE SUBSTANTIALLY
WARMER (OR COOLER) THAN THE CURRENT FORECAST DEPENDING ON THE
POSITION OF THE FRONT. STAY TUNED...AND BE READY FOR CHANGES IN THE
TEMPERATURE FORECAST AS MODEL GUIDANCE FINE TUNES THE POSITION OF
THE MEANDERING BOUNDARY.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE AND WIDESPREAD VFR CONDITIONS WILL PERSIST THROUGH THE
OVERNIGHT. AS A HIGH SLIDES OFF TO THE EAST...A WARM FRONT WILL LIFT
ACROSS THE AREA BRINGING INCREASING MID/HIGH CLOUD COVER. CIGS ARE
EXPECTED TO LOWER TO AROUND 5KFT ACROSS THE NORTH COUNTRY AND A FEW
LIGHT AREAS OF MIXED PRECIP CHANGING OVER TO RAIN SHOWERS WILL BE
POSSIBLE ACROSS THAT AREA AS WELL. OTHERWISE...LOOK FOR DRY
WEATHER TO PERSIST ACROSS THE REST OF THE FORECAST AREA OVERNIGHT.

CLOUD COVER SHOULD CLEAR OUT THURSDAY MORNING AND VFR CONDITIONS
WILL CONTINUE. STRENGTHENING SOUTHERLY WINDS WILL DEVELOP THROUGH
THE MORNING WITH GUSTS TO 30KT POSSIBLE THU AFTERNOON AS A LOW LEVEL
JET BEGINS TO MOVE OVERHEAD. THE CORE OF THIS JET WILL MOVE ACROSS
THE FORECAST AREA THU EVENING IMMEDIATELY AHEAD OF A COLD FRONT THAT
WILL CROSS THE REGION. THIS FRONT...EXPECTED TO MOVE INTO FAR WNY
AROUND 00Z...MAY BE ACCOMPANIED BY A PERIOD OF HEAVY SHOWERS WITH A
FEW RUMBLES OF THUNDER POSSIBLE...IN ADDITION TO WINDS THAT MAY GUST
TO 40 KTS.

OUTLOOK...
THURSDAY NIGHT...VFR/MVFR WITH RAIN SHOWERS AND A CHANCE OF
THUNDERSTORMS.
FRIDAY...VFR WITH A CHANCE OF RAIN SHOWERS.
FRIDAY NIGHT...VFR/MVFR WITH RAIN SHOWERS CHANGING TO SNOW SHOWERS.
SATURDAY AND SUNDAY...MVFR/IFR WITH A CHANCE OF SNOW SHOWERS.
MONDAY...VFR WITH A CHANCE OF SNOW AND RAIN SHOWERS.

&&

.MARINE...
HIGH PRESSURE AND LIGHT WINDS WILL SLOWLY SHIFT EAST OF THE LOWER
GREAT LAKES OVERNIGHT. SOUTHWEST WINDS WILL INCREASE ON THURSDAY
AHEAD OF AN APPROACHING COLD FRONT BRINGING CHOPPY CONDITIONS
ACROSS THE OPEN WATERS WITH THE HIGHEST ONTARIO WAVES ALONG THE
NORTH SHORE. WINDS WILL LIKELY CLIMB OVER 20KTS FOR A TIME THU
EVENING ALONG AND JUST AHEAD OF THE APPROACHING COLD FRONT...WITH
GUSTS AS HIGH AS 35KT POSSIBLE. A SMALL CRAFT ADVISORY REMAINS
IN EFFECT FOR THE NEAR SHORE WATERS OF LAKE ONTARIO FOR THURSDAY
NIGHT. THE GUSTY WINDS MAY ALSO CONTRIBUTE TO SHIFTING ICE ON LAKE
ERIE AND THE EASTERN END OF LAKE ONTARIO. AS THE COLD FRONT SAGS
SOUTH OVER NEW YORK FRIDAY INTO SATURDAY WINDS WILL VEER TO
NORTHERLY WITH WAVES INCREASING ALONG THE SOUTHERN ONTARIO LAKE
SHORE.

&&

.HYDROLOGY...
TEMPERATURES WILL WARM SIGNIFICANTLY ON THURSDAY...AND ARE LIKELY TO
REMAIN ABOVE FREEZING THROUGH FRIDAY EVENING. ALTHOUGH MUCH OF THE
SNOW HAS MELTED SOUTH OF LAKE ONTARIO...THERE ARE STILL SIGNIFICANT
PATCHES...ESPECIALLY IN SHELTERED AREAS AND ACROSS HIGHER TERRAIN.
THERE IS STILL A SIGNIFICANT SNOW PACK IN PLACE EAST OF LAKE
ONTARIO.

RAINFALL AMOUNTS ARE EXPECTED TO BE LIGHT ON THURSDAY
EVENING...GENERALLY A QUARTER TO HALF INCH. SOME ADDITIONAL
PRECIPITATION IS EXPECTED FRIDAY NIGHT...BUT THIS MAY ACTUALLY END AS
SNOW AS COOLER AIR BUILDS IN. THE COMBINATION OF SNOW MELT FROM WARM
TEMPERATURES AND MODEST RAINFALL COULD POTENTIALLY CAUSE SOME
FLOODING.

BASED ON THE CURRENT FORECAST AND ENSEMBLES THERE IS A LOW CHANCE
FOR FLOODING IN SOME OF THE CREEKS AND RIVERS. MMEFS ENSEMBLES
SUGGEST THERE IS A LOW PROBABILITY FOR MINOR FLOODING IN SOME AREA
CREEKS AND RIVERS. THERE IS ALSO A CHANCE FOR ICE JAMS IN THE
BLACK RIVER BASIN WHERE SOME SMALLER WATERWAYS STILL HAVE ICE IN
PLACE. THIS RISK FOR FLOODING IS MENTIONED IN THE HWO
PRODUCT...AND IT IS POSSIBLE A FLOOD WATCH WILL BE ISSUED IF THE
EXPECTED RAINFALL OR SNOW MELT INCREASES.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 5 AM EDT FRIDAY
         FOR LOZ042>045.

&&

$$

SYNOPSIS...SMITH/TMA
NEAR TERM...SMITH/TMA/WOOD
SHORT TERM...APFFEL
LONG TERM...APFFEL
AVIATION...TMA/WOOD
MARINE...SMITH/TMA/WOOD
HYDROLOGY...APFFEL



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