Area Forecast Discussion
Issued by NWS Buffalo, NY

Home | 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 310604
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
204 AM EDT FRI OCT 31 2014

.SYNOPSIS...
A WEAK WARM FRONT WILL EXTEND EASTWARD ACROSS THE VICINITY OF LAKE
ONTARIO TODAY...WITH A FEW LIGHT SHOWERS THIS MORNING. THESE SHOWERS
WILL BECOME MORE NUMEROUS THIS AFTERNOON AS AN AREA OF LOW PRESSURE
DRAWS CLOSER TOWARDS LAKE ERIE. BEHIND THIS AREA OF LOW PRESSURE
CHILLY TEMPERATURES ARE EXPECTED FOR THE WEEKEND ALONG WITH
OCCASIONAL RAIN SHOWERS SATURDAY. MOST OF THE PRECIPITATION IS
EXPECTED TO REMAIN LIQUID...ALTHOUGH A FEW WET SNOWFLAKES MAY MIX IN
SATURDAY NIGHT. A WARMING TREND IS THEN EXPECTED EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
ABUNDANT LOW LEVEL MOISTURE THIS EARLY MORNING IS ALLOWING FOR
PLENTY OF STRATUS ACROSS OUR REGION. A WARM FRONT EXTENDING EASTWARD
ACROSS THE VICINITY OF LAKE ONTARIO IS FROM AN AREA OF LOW PRESSURE
NEAR NORTHERN LAKE HURON THIS EARLY MORNING. A FEW RAIN SHOWERS ARE
EXPECTED TO FORM OVER NIGHT NEAR LAKE ERIE AND ALSO ONTARIO...WITH
LIFT ALONG THE FRONTAL BOUNDARY THROUGH THE MOISTENING LOWER LEVELS
YIELDING THESE RAIN SHOWERS. FARTHER INLAND WITH LESS LIFT...EXPECT
MAINLY DRY CONDITIONS THROUGH THE NIGHT.

MODELS HAVE TRENDED TOWARD A SPLITTING SOLUTION...WITH THE MAIN
VORTICITY MAX DIGGING INTO THE CAROLINAS...LEAVING OUR AREA UNDER
WEAK / SPLIT FLOW ALOFT. WE WILL KEEP SOUTHERLY FLOW INTO THE
FORECAST AREA WITH DECENT MOISTURE THROUGH THE DAY FRIDAY. THE WEAK
SURFACE BOUNDARY TO OUR NORTH ON FRIDAY MORNING WILL SLOWLY SHIFT
SOUTH AND EASTWARD THROUGH THE DAY ON FRIDAY...AS THE NORTHERN
STREAM TROUGH PUSHES EASTWARD. OUR BEST CHANCE OF MORE NUMEROUS
SHOWERS SPREADING ACROSS THE FORECAST AREA WILL BE FRIDAY AFTERNOON
AND EVENING MAINLY ACROSS WESTERN NY. WHILE QPF IS EXPECTED TO BE
LIGHT DUE TO THE LACK OF WELL-DEFINED FORCING...THE HIGHEST AMOUNTS
WILL BE ACROSS WESTERN NEW YORK...WITH PROGRESSIVELY LESS RAINFALL
TO THE EAST...ESPECIALLY DROPPING OFF EAST OF THE GENESEE VALLEY AND
THE ROCHESTER AREA.

TEMPERATURE VARIANCE WILL BE VERY LOW BETWEEN TONIGHT AND
FRIDAY...AS CLOUD COVER AND LOW-LEVEL MOISTURE WILL HELP KEEP
TEMPERATURES UP OVERNIGHT. ON FRIDAY...EXPECT CLOUD COVER AND
INCREASING PRECIPITATION...ESPECIALLY ACROSS WESTERN NEW YORK...TO
KEEP TEMPERATURES FROM RISING MUCH DURING THE DAY. THE DIURNAL RANGE
IN TEMPERATURES WILL ONLY BE AROUND 10 DEGREES...WITH LOWS TONIGHT
IN THE UPPER 30S TO LOWER 40S ON THE LAKE PLAINS AND MID 30S IN THE
INTERIOR SOUTHERN TIER AND TUG HILL REGION...FOLLOWED BY HIGHS IN
THE UPPER 40S TO LOWER 50S ON THE LAKE PLAINS AND MID 40S ON THE
HILLS FRIDAY.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
IT WILL BE A WET START TO THE WEEKEND...AT LEAST ACROSS WESTERN NEW
YORK AND PORTIONS OF THE GENESEE VALLEY AS THE AREA WILL BE UNDER
THE INFLUENCE OF NORTHERLY UPSLOPE FLOW OFF OF LAKE ONTARIO IN THE
WAKE OF A COMPLEX LOW PRESSURE SYSTEM CUTTING TO THE SOUTHEAST OF
THE FORECAST AREA ACROSS THE SOUTHERN APPALACHIANS. OROGRAPHIC LIFT
WILL BE REINFORCED BY THE APPROACH OF A SECONDARY UPPER LEVEL TROUGH
AND ASSOCIATED LIFT. WHILE TEMPERATURES ALOFT...IN THE -2C TO -4C
RANGE WILL BE COLD ENOUGH TO ADD LAKE ENHANCEMENT OF PRECIPITATION
TO THE MIX...IT WILL NOT LIKELY BE COLD ENOUGH TO FACILITATE A
TRANSITION OVER TO SNOW. RATHER...WESTERN NEW YORK CAN EXPECT A
GENERAL LIGHT RAINFALL THROUGH THE NIGHT. LAKE ENHANCEMENT WILL BE
SIGNIFICANTLY DIMINISHED EAST OF THE GENESEE VALLEY UNDER
NORTH/NORTHEAST FLOW...AND AS SUCH ANY RAIN SHOWERS WILL BE LIMITED
IN SCOPE AND MAINLY DRIVEN BY THE APPROACHING SHORTWAVE. AS
MENTIONED ABOVE...THE AREA WILL BE UNDER THE INFLUENCE OF RELATIVELY
MILD MARITIME AIR FROM THE ATLANTIC AND THAT WILL KEEP LOWS FROM
DROPPING OUT OF THE MID TO UPPER 30S WITH AREAS ALONG THE LAKE
PLAINS LIKELY STAYING IN THE LOWER 40S.

THE NORTHERLY FLOW WILL CONTINUE ON SATURDAY WITH THE FOCUS OF
PRECIPITATION SHIFTING SLIGHTLY EAST TO THE GENESEE VALLEY AND
FINGER LAKES AS THE UPPER LEVEL TROUGH MOVES OVERHEAD. FLOW WILL
CONTINUE TO BACK TO THE NORTHWEST SUNDAY NIGHT BEHIND THE TROUGH.
SATURDAY NIGHT WILL PRESENT THE GREATEST OPPORTUNITY FOR A LIGHT
SNOW ACCUMULATION ACROSS CENTRAL NEW YORK AS THE COMBINATION OF
NIGHTFALL AND THE ARRIVAL OF COLDER AIR ALOFT WILL PUSH TEMPERATURES
BELOW FREEZING ACROSS THE FORECAST AIR. HOWEVER THE FLY IN THE
OINTMENT WILL BE THE DRY AIR ALOFT THAT WILL BE ACCOMPANYING THIS
COLD PUSH. AS THE AIR IN THE DENDRITIC GROWTH ZONE DRIES OUT...THERE
IS A POTENTIAL THAT WE COULD SEE ANY UPSLOPE/LAKE ENHANCED SNOW
SHOWERS PETER OUT INTO PATCHY FREEZING DRIZZLE OR POSSIBLY JUST
LAKE-INDUCED STRATUS WITH NO PRECIPITATION AT ALL.

ANY LINGERING LIGHT PRECIPITATION SHOULD FIZZLE OUT SUNDAY MORNING
AS INCREASING SUBSIDENCE AND DRY AIR ALOFT WILL OVERCOME ANY LAKE
ENHANCEMENT...THOUGH THERE WILL LIKELY STILL BE PLENTY OF CLOUDS TO
GO AROUND ON WHAT WILL OTHERWISE BE A DRY AND CHILLY DAY WHERE
TEMPERATURES WILL STRUGGLE TO REACH THE LOWER 40S NEAR THE LAKES AND
HIGHER ELEVATIONS OF THE SOUTHERN TIER AND NORTH COUNTRY WILL LIKELY
STAY LOCKED IN THE UPPER 30S. WE CAN THEN EXPECT ONE MORE NIGHT OF
FREEZING TEMPERATURES SUNDAY NIGHT BEFORE TEMPERATURES MODERATE NEXT
WEEK

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AFTER A COOL AND SHOWER WEEKEND...WESTERN AND NORTH-CENTRAL NEW YORK
WILL TRANSITION TO A DRIER AND MORE MILD REGIME AS WE MOVE INTO THE
NEW WEEK. THIS WILL BE COURTESY OF STEEP UPPER LEVEL RIDGE THAT WILL
BE CROSSING THE GREAT LAKES MONDAY. FLOW BACKING TO THE SOUTHWEST
WILL ADVECT WARMER AIR ACROSS THE LOWER GREAT LAKES...PUSHING
TEMPERATURES BACK ABOVE THE 50 DEGREE MARK MONDAY AND BY TUESDAY
MANY AREAS WILL CLIMB INTO THE UPPER 50S WITH PERHAPS A 60 DEGREE
READING OR TWO NOT OUT OF THE QUESTION IN THE TYPICALLY WARMER SPOTS
OF THE GENESEE VALLEY AND NORTH OF THE FINGER LAKES. ALTHOUGH THE
WARM ADVECTION WILL PUT AN END TO ANY LAKE EFFECT CLOUD
COVER...THERE WILL STILL BE PLENTY OF MID AND HIGH CLOUDS TO GO
AROUND MONDAY AND TUESDAY COURTESY OF WARM ADVECTION ALOFT.

AFTER A DRY START TO THE WEEK...WE WILL SEE SHOWERS CREEP BACK INTO
THE FORECAST AS A POTENT UPPER LEVEL TROUGH AND ACCOMPANYING SURFACE
LOW LIFT FROM WESTERN ONTARIO INTO NORTHERN QUEBEC. AS THE LOW
TRACKS INTO NORTHERN QUEBEC...IT WILL DRAG A TRAILING COLD FRONT
ACROSS THE LOWER GREAT LAKES TUESDAY NIGHT. THE LATEST MODEL RUNS
ARE INDICATING A CHANCE OF SHOWERS MONDAY NIGHT AS THE WARM FRONT
LIFTS ACROSS THE REGION...HOWEVER THE BETTER PRECIP CHANCES WILL BE
ASSOCIATED WITH THE PASSAGE OF THE COLD FRONT TUESDAY NIGHT INTO
WEDNESDAY GIVEN THE FAVORABLE FRONTOGENETIC AND UPPER LEVEL FORCING
AND RETURN FLOW SUPPLYING GULF MOISTURE ACROSS THE OHIO VALLEY AND
LOWER LAKES ALONG THE FRONTAL BOUNDARY.

THE LATEST MODEL RUNS NOW SHOW SOME DIVERGENCE IN SOLUTIONS
REGARDING THE SPEED OF THE FRONTAL PASSAGE TUESDAY NIGHT/WEDNESDAY.
THE GFS BRINGS A FRONTAL WAVE ACROSS NEW YORK THAT SLOWS UP THE
FRONT WEDNESDAY WHILE THE ECMWF SPEEDS THE FRONT THROUGH WITH A
REINFORCING SHORTWAVE BRINGING ANOTHER ROUND OF SHOWERS WEDNESDAY
NIGHT. GIVEN THESE DIFFERENCES...WILL JUST COVER THE PERIOD WITH LOW
CHANCE POPS FOR THE TIME BEING AND KEEP TEMPERATURES RIGHT AROUND
CLIMATOLOGY AS THE REGION WILL LIKELY BE AWASH IN A MILD PACIFIC
AIRMASS THAT WILL BE ENCOMPASSING MUCH OF THE NORTHERN TIER OF THE
COUNTRY.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AT 06Z MAINLY VFR FLIGHT CONDITIONS WERE FOUND ACROSS THE
REGION...THOUGH A WEALTH OF STRATUS MAY OCCASIONALLY DROP DOWN INTO
HIGH END MVFR THIS MORNING. THIS WILL ESPECIALLY BE TRUE NEAR LAKE
ERIE AND ALSO LAKE ONTARIO WHERE A WARM FRONT EXTENDING EASTWARD
ACROSS THE VICINITY OF LAKE ONTARIO MAY YIELD A FEW SHOWERS IN
ADDITION TO THE LOWERING OF CIGS. WILL PLACE A VCSH IN THE KBUF/KIAG
TAFS FOR EARLY THIS MORNING FOR THESE SCATTERED LIGHT RAIN SHOWERS.

LATER IN THE DAY THESE RAIN SHOWERS ARE EXPECTED TO BECOME MORE
NUMEROUS AS THE WARM FRONT`S PARENT LOW DROPS SOUTHEASTWARD ACROSS
LAKE ERIE. SHOWER ACTIVITY IS EXPECTED TO BE LIKELY ACROSS WESTERN
NEW YORK AND LIGHT RAIN SHOWERS WILL BE PLACED IN THESE TAFS...WHILE
HOLDING JUST A VCSH FOR THE KART TERMINAL AND EASTERN LAKE ONTARIO
LOCATIONS WHERE RAIN SHOWERS WILL LIKELY BE ISOLATED IN NATURE.

A DEEPENING UPPER LEVEL TROUGH OVER THE OHIO VALLEY WILL SETTLE
TOWARDS THE CAROLINAS BY SATURDAY MORNING. THIS LOW PRESSURE OVER
LAKE ERIE WILL REFORM AND INTENSIFY EAST OF THE APPALACHIANS LATE
TONIGHT. AS THE LOW SURFACE PRESSURE CROSSES THE REGION...COMBINED
WITH THE NEARING UPPER LEVEL TROUGH LIGHT RAIN SHOWERS ARE LIKELY
THROUGH THE NIGHT TONIGHT...AGAIN MOST LIKELY FARTHER WESTWARD.

BEHIND THIS AREA OF LOW PRESSURE WINDS WILL INCREASE FROM THE
NORTH-NORTHEAST. COOLER AIR FLOWING BEHIND THIS LOW PRESSURE
COMBINED WITH THE NORTHEAST WINDS WILL LIKELY FORM MVFR AND LATER
IFR FLIGHT CONDITIONS FRIDAY NIGHT. CLIMATOLOGY PLACES IFR AT BETTER
THAN 50 PERCENT FOR KJHW...WHILE THE NORTHEAST FLOW OFF LAKE ONTARIO
MAY ALSO BRING IFR CIGS FOR KROC...IN ADDITION TO KIAG AND KBUF.

OUTLOOK...
SATURDAY...AREAS OF MVFR/IFR WITH OCCASIONAL SHOWERS.
SUNDAY...MVFR IMPROVING TO VFR WITH SCATTERED SPRINKLES AND
FLURRIES.
MONDAY...MAINLY VFR.
TUESDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.

&&

.MARINE...
WEST WINDS WILL CONTINUE TO PRODUCE CHOPPY WAVE ACTION ON THE EAST
HALF OF LAKE ONTARIO THIS EVENING WITH CONDITIONS BELOW SMALL CRAFT
ADVISORY CRITERIA.

WINDS WILL BECOME LIGHT AND VARIABLE OVERNIGHT ACROSS BOTH LAKE ERIE
AND LAKE ONTARIO...BEFORE SOUTHERLY TO SOUTHEASTERLY WINDS DEVELOP
DURING THE DAY ON FRIDAY WITH RELATIVELY FLAT WAVE ACTION.

STRONGER NORTHERLY WINDS WILL THEN INCREASE EARLY SATURDAY
MORNING...WITH WINDS OVER 20KTS COMMON ACROSS LAKE ONTARIO. WAVE
HEIGHTS SHOULD INCREASE TO 3 TO 6 FEET...ESPECIALLY ACROSS WESTERN
LAKE ONTARIO THROUGH THE DAY SATURDAY. THUS HAVE ISSUED A SMALL
CRAFT ADVISORY FOR WESTERN LAKE ONTARIO AND THE LOWER NIAGARA RIVER.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM EDT SATURDAY TO 1 AM EST SUNDAY
         FOR LOZ030-042.

&&

$$

SYNOPSIS...THOMAS
NEAR TERM...HITCHCOCK/THOMAS
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...THOMAS
MARINE...CHURCH/HITCHCOCK







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