Area Forecast Discussion
Issued by NWS Buffalo, NY

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 160847
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
447 AM EDT TUE SEP 16 2014

.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE COMBINED WITH A WEAK SURFACE FRONT WILL
CONTINUE RAIN SHOWERS ACROSS THE REGION THIS MORNING. THE RAIN WILL
THEN TAPER OFF FROM WEST TO EAST THROUGH TUESDAY MORNING WITH
SUNSHINE RETURNING IN THE AFTERNOON. AN AREA OF HIGH PRESSURE WILL
BRING COOL AND DRY CONDITIONS INTO WEDNESDAY BEFORE ANOTHER COLD
FRONT BRINGS A SLIGHT CHANCE FOR RAIN SHOWERS WEDNESDAY NIGHT.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AREA RADARS SHOW A WIDE SWATH OF RAIN SHOWERS OVER WESTERN AND
CENTRAL NEW YORK EARLY THIS MORNING AHEAD OF THE AXIS OF AN UPPER
LEVEL SHORTWAVE TROUGH AND SURFACE TROUGH APPROACHING THE EASTERN
GREAT LAKES. RADAR ESTIMATED RAINFALL TOTALS RANGE FROM A QUARTER
INCH OR LESS FROM LAKE ONTARIO NORTHWARD TO NEAR AN INCH ALONG THE
NY/PA BORDER. KBUF SHOWS THE BACK EDGE OF THE SHOWERS IS NOW PUSHING
EAST OF LAKE ERIE SO EXPECT ACTIVITY TO TAPER OFF FROM WEST TO EAST
THROUGH THE MORNING HOURS.

BY 12Z TUESDAY THE AXIS OF THE UPPER LEVEL SHORTWAVE WILL BE ACROSS
CNY...WITH THE COLD FRONT SIMILARLY NEAR CNY AS WELL. THUS SHOWERS
WILL LIKELY BE CONFINED MAINLY FOR AREAS EAST OF THE GENESEE VALLEY.
THERE IS NOT A LOT OF COLD AIR ADVECTION BEHIND THIS COLD FRONT AS
850 HPA TEMPERATURES ONLY DROP A FEW DEGREES. HOWEVER EVEN THESE 850
HPA READING OF AROUND +4C OVER THE WARM LAKE WATERS ALONG WITH WINDS
VEERING TO WEST-NORTHWESTERLY MAY BRING A FEW LAKE EFFECT SPRINKLES
OR LIGHT RAIN SHOWER ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER.
WILL LEAVE LOW CHANCE POPS IN THROUGH THE MORNING HERE...WITH
DAYTIME MIXING ENDING ANY ACTIVITY BY LATE MORNING. EAST OF LAKE
ONTARIO BY TIME ANY LAKE EFFECT SHOWERS GENERATE BEHIND THE COLD
FRONT...FEEL THAT IT WILL BE LATE ENOUGH IN THE MORNING THAT NO
ORGANIZED SHOWERS WILL DEVELOP.

HIGHS TODAY WILL RANGE THROUGH THE 60S. THE WARMEST AREAS IN THE
REGION...WHERE HIGHS MAY REACH INTO THE MID 60S WILL BE ACROSS
NORTHWESTERN NIAGARA FRONTIER AND THE SAINT LAWRENCE VALLEY WHERE
ADDITIONAL SUNSHINE WILL PROMOTE THE GREATEST AFTERNOON WARMING.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
A HIGH AMPLITUDE UPPER LEVEL PATTERN WILL BE IN PLACE ACROSS NORTH
AMERICA AS WE OPEN THE PERIOD WITH A DEEP TROUGH ACROSS THE EASTERN
UNITED STATES EXTENDING FROM A POLAR LOW OVER NORTHERN QUEBEC WHILE
STRONG RIDGING WILL BE FOUND OVER THE WEST. HIGH PRESSURE AT THE
SURFACE WILL PROVIDE A SUNNY DAY FOR MUCH OF THE LOWER GREAT
LAKES...HOWEVER A POTENT SHORTWAVE DROPPING AROUND THE BASE OF THE
AFOREMENTIONED UPPER LOW WILL SHUNT A COLD FRONT SOUTH TOWARDS OUR
REGION WITH CLOUDS INCREASING ACROSS THE NORTH COUNTRY ON WEDNESDAY
AS THE COLD FRONT APPROACHES THE REGION. WHILE THE BULK OF THE DPVA
AND ASSOCIATED SHOWER ACTIVITY SHOULD REMAIN NORTH OF THE
BORDER...THERE WILL BE A CHANCE OF A FEW SPRINKLES WEDNESDAY NIGHT
AS THE SURFACE COLD FRONT SAGS SOUTH ACROSS LAKE ONTARIO.

850MB TEMPS OF +4 TO +6C WILL SUPPORT HIGHS IN THE MID 60S ACROSS
THE LOWER ELEVATIONS OF THE FORECAST AREA WHILE HIGHER ELEVATIONS OF
THE SOUTHERN TIER AND NORTH COUNTRY WILL RUN A FEW DEGREES
COOLER...IN THE LOWER 60S. FOR WEDNESDAY NIGHT...ENCROACHING CLOUD
COVER ASSOCIATED WITH THE COLD FRONT WILL KEEP TEMPERATURES LOWS IN
THE MID TO UPPER 40S ALONG THE LAKE PLAINS AND INTO THE NORTH
COUNTRY WHILE ACROSS THE SOUTHERN TIER THERE MAY BE JUST ENOUGH
SOUTHWESTERLY FLOW AHEAD OF THE APPROACHING COLD FRONT TO LIMIT
RADIATIONAL COOLING AND ONLY PRODUCE LOWS IN THE LOW TO MID 40S.

THE COLD FRONT WILL DROP SOUTH OF LAKE ONTARIO AROUND DAYBREAK
THURSDAY MORNING AND CONTINUE TO SAG SOUTH ACROSS THE FORECAST AREA
DURING THE DAY. UPSLOPE NORTHERLY FLOW OFF LAKE ONTARIO BEHIND THE
FRONT COUPLED WITH 850MB TEMPS DROPPING TO AROUND +2C WILL GENERATE
PLENTY OF STRATUS ACROSS MUCH OF WESTERN AND NORTH-CENTRAL NEW
YORK...THOUGH THE NORTH COUNTRY SHOULD SEE SUNSHINE IN THE
AFTERNOON AS IT WILL ESCAPE THE INFLUENCE OF THE LAKE. THE
COMBINATION OF COLD ADVECTION AND ABUNDANT CLOUD COVER WILL MAKE
FOR A CHILLY DAY ACROSS THE AREA WITH HIGHS ONLY EXPECTED TO TOP
OUT IN THE MID 50S.

THE CLOUD COVER SHOULD DIMINISH THURSDAY NIGHT AS THE CENTER OF
THE SURFACE HIGH PASSES TO OUR NORTH AND LOW LEVEL FLOW VEERS AROUND
TO THE EAST...PARTICULARLY EAST OF THE GENESEE VALLEY AND THE
NORTH COUNTRY. THIS CLEARING COUPLED WITH THE VERY DRY AIR
ADVECTING INTO THE REGION COULD RESULT IN THE FIRST WIDESPREAD
FREEZE OF THE SEASON ACROSS THE NORTH COUNTRY WHILE FROST MAY BE
POSSIBLE ELSEWHERE WITH THE EXCEPTIONS OF AREAS NEAR THE LAKE ERIE
AND ONTARIO SHORELINES.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
THE ARCTIC HIGH AND ASSOCIATED COLD AIR WILL MOVE OFF TO THE EAST
ON FRIDAY AS THE HIGH AMPLITUDE PATTERN OF EARLIER IN THE WEEK
BRIEFLY GIVES WAY TO A MORE ZONAL FLOW ACROSS THE NORTHERN TIER OF
THE COUNTRY. WITH THE SURFACE HIGH MOVING OFF TO OUR EAST ON
FRIDAY...INCREASING SOUTHERLY RETURN FLOW WILL ALLOW FOR
TEMPERATURES TO WARM BACK INTO THE 60S ON FRIDAY BEFORE BOOSTING
READINGS INTO THE 70S ON SATURDAY WITH AN ABUNDANCE OF SUNSHINE BOTH
DAYS THANKS TO THE ABUNDANCE OF DRY AIR ACROSS THE REGION.

A MUCH MORE COMPLEX PATTERN EVOLVES FOR THE LATTER HALF OF THE
WEEKEND INTO THE BEGINNING OF NEXT WEEK. THERE ARE ESSENTIALLY THREE
TIERS OF UPPER LEVEL ENERGY THAT WILL BE MAKING THEIR WAY ACROSS
NORTH AMERICA DURING THIS PERIOD. THE FIRST IS OVER HUDSON BAY
ASSOCIATED WITH THE POLAR VORTEX. THE SECOND IS A SHORTWAVE
TRACKING OUT OF THE NORTHERN ROCKIES WITH AN ATTENDANT SURFACE LOW
THAT MOVES INTO THE WESTERN GREAT LAKES SATURDAY. THE THIRD AND
FINAL FACTOR IS THE REMNANTS OF HURRICANE ODILE THAT WILL BE
MEANDERING ACROSS THE SOUTHERN PLAINS BY SATURDAY. TO VARYING
DEGREES THE GLOBAL MODELS PHASE ALL THREE OF THESE SYSTEMS AND BRING
THEM ACROSS EASTERN NORTH AMERICA WITH THE X-FACTOR BEING THE SPEED
AND INTENSITY OF YET ANOTHER PLAYER...A POTENT SHORTWAVE DROPPING
OUT OF THE MACKENZIE BASIN OF FAR NORTHWESTERN CANADA SATURDAY NIGHT
INTO SUNDAY. THIS PARTICULAR FEATURE MAY END UP DIGGING FAR
ENOUGH SOUTH TO GENERATE A LARGE SURFACE CYCLONE OVER WESTERN
ONTARIO ON SUNDAY...AS DEPICTED BY THE ECMWF...OR ARRIVE TOO LATE
TO DO SO AND INSTEAD REINVIGORATE THE WESTERN GREAT LAKES SURFACE
LOW AS IT LIFTS INTO WESTERN QUEBEC. THE GLOBAL GEM IS EVEN
FARTHER NORTH AND EAST WITH THIS FEATURE...HAVING IT MISS OUR
GREAT LAKES LOW ENTIRELY.

IN SPITE OF THE SIGNIFICANT DIFFERENCES IN DETAILS BETWEEN THESE
SCENARIOS...THE TIMING OF IMPACTS ON SENSIBLE WEATHER ACROSS THE
LOWER GREAT LAKES IS SURPRISINGLY SIMILAR. AFTER ONE MORE WARM AND
DRY DAY SUNDAY...SHOWERS WILL LIKELY BREAK OUT ACROSS WESTERN NEW
YORK SOMETIME SUNDAY NIGHT AS THE SURFACE/UPPER LEVEL TROUGHS
APPROACH THE AREA. GIVEN THE STRONG DYNAMICS AT WORK ALONG WITH A
DECENT RETURN FLOW OFF OF MOISTURE OFF OF THE GULF OF MEXICO AND
POTENTIAL CONTRIBUTIONS FROM WHATEVER IS LEFT FROM ODILE...WE COULD
SEE A PERIOD OF MODERATE TO HEAVY RAINFALL SUNDAY NIGHT INTO MONDAY.
A COLD FRONT WILL LIKELY CROSS THE REGION MONDAY BRINGING A
POTENTIALLY SIGNIFICANT COOL-DOWN...ALTHOUGH SIGNIFICANCE OF THIS
COOL-DOWN WILL BE A FUNCTION OF THE FINAL TRACK OF THE AFOREMENTIONED
NORTHWEST CANADIAN SHORTWAVE AND THE DEGREE TO WHICH IT ENHANCES THE
LOW OVER WESTERN ONTARIO AND SUBSEQUENT POSSIBLE OCCLUSION ACROSS
THE GREAT LAKES.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
A SURFACE AND UPPER LEVEL TROUGH ARE APPROACHING THE EASTERN GREAT
LAKES THIS MORNING WITH A SWATH OF RAIN SHOWERS ACROSS NEW YORK
STATE. LIGHT TO OCCASIONALLY MODERATE RAINFALL AND LOWERING CIGS ARE
POSSIBLE ACROSS THE CWA MAINLY THROUGH 12Z. MUCH OF THE TIME SHOULD
BE VFR...THOUGH OCCASIONAL MVFR VSBYS AND IFR CIGS ARE POSSIBLE
WITHIN THE RAIN SHOWERS.

THE AXIS OF THE UPPER LEVEL TROUGH WILL PASS EAST ACROSS NY THIS
MORNING BRINGING AN END TO THE RAINFALL. SOME SCATTERED LIGHT SHOWERS
OR SPRINKLES MAY LINGER ACROSS THE SOUTHERN TIER ALONG WITH MVFR
CIGS THROUGH THE MORNING AS BOUNDARY LAYER WINDS VEER AROUND TO
NORTHWESTERLY. OTHERWISE DECREASING CLOUDS ARE EXPECTED AFTER 12Z
WITH A GENERAL LIGHT WIND FLOW AS HIGH PRESSURE BUILDS OVERHEAD.
SOME LAKE EFFECT CLOUDS ARE POSSIBLE IN THE UPSLOPE FLOW INLAND FROM
THE LAKES TONIGHT BUT EXPECT THIS TO REMAIN VFR.

OUTLOOK...
TUESDAY NIGHT THROUGH SATURDAY...GENERALLY VFR. SOME PATCHES OF MVFR
CIGS BOTH TUESDAY AND WEDNESDAY NIGHT. SOME VALLEY FOG WITH
LOCALIZED IFR FLIGHT VSBYS ACROSS THE SOUTHERN TIER EACH MORNING.

&&

.MARINE...
NORTHWESTERLY WINDS WILL DEVELOP BEHIND THE PASSAGE OF A WEAK COLD
FRONT AND UPPER LEVEL SHORTWAVE TODAY. THESE WINDS WILL BRING 2 TO 4
FOOT WAVES ON LAKE ERIE...AND ON LAKE ONTARIO A LONGER FETCH TO THE
LAKE WILL ALLOW FOR 3 TO 5 FOOT WAVES. BASED ON THIS ALONG WITH
WINDS NEARING 20 KNOTS WILL CONTINUE SMALL CRAFT ADVISORIES FOR LAKE
ONTARIO THIS AFTERNOON THROUGH THIS EVENING.

WINDS WILL EVENTUALLY BACK AROUND TO THE WEST TONIGHT AS HIGH
PRESSURE BEGINS TO BUILD INTO THE LOWER GREAT LAKES. WINDS AND WAVES
WILL GRADUALLY SUBSIDE THROUGH THE OVERNIGHT HOURS AND INTO
WEDNESDAY BEFORE BUILDING ONCE AGAIN WEDNESDAY NIGHT AS A COLD FRONT
DROPS SOUTH OUT OF CANADA.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 2 AM EDT
         WEDNESDAY FOR LOZ044.

&&

$$

SYNOPSIS...SMITH
NEAR TERM...SMITH/THOMAS
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...SMITH/THOMAS
MARINE...SMITH/THOMAS






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