Area Forecast Discussion
Issued by NWS Buffalo, NY

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000
FXUS61 KBUF 261744
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
144 PM EDT WED AUG 26 2015

.SYNOPSIS...
DEEP LOW PRESSURE NEAR JAMES BAY WILL MAINTAIN COOL...UNSETTLED
WEATHER ACROSS THE REGION THROUGH MUCH OF THE WEEK. HIGH PRESSURE
WILL BUILD ACROSS THE GREAT LAKES WITH TEMPERATURES RETURNING TO
MORE SEASONABLE READINGS.

&&

.NEAR TERM /THROUGH TONIGHT/...
AN UPPER LEVEL LOW TO OUR NORTH WILL MAINTAIN A COOL AND MOIST
CYCLONIC FLOW ACROSS THE REGION THIS AFTERNOON. RADAR IMAGERY
SHOWING LAKE EFFECT SHOWERS EVOLVING INTO SCATTERED DIURNAL SHOWERS
WITH THE ONSET OF PEAK DAYTIME MIXING WHICH DISRUPTS THE LAKE EFFECT
PROCESS. SCATTERED SHOWERS WILL BE POSSIBLE JUST ABOUT ANYWHERE THIS
AFTERNOON WITH COOL AIR ALOFT AND PLENTY OF WRAP AROUND MOISTURE.

THE 12Z BUF SOUNDING ALSO SHOWS A CAP AT 750 MB. IR CLOUD TOPS
CONFIRM THAT LAKE EFFECT SHOWERS HAVE NOT BEEN ABLE TO BREAK
THROUGH THIS...AND UNLESS THIS CHANGES IT WILL BE DIFFICULT FOR
ANY THUNDERSTORMS TO DEVELOP.

OTHERWISE...ANOTHER COOL AND CLOUDY DAY IS EXPECTED TODAY. VERY
SIMILAR TO WHAT WE SAW ON TUESDAY. HIGH TEMPS WILL ONLY CLIMB INTO
THE MID TO UPPER 60S OR ABOUT 10 DEGREES BELOW NORMAL.

TONIGHT COOLER AIR ALOFT ARRIVES BEHIND THE SURFACE AND UPPER LEVEL
TROUGH AXIS. THIS WILL FURTHER BOOST LAKE-INDUCED INSTABILITY.
SURFACE AND 850MB WINDS WILL VEER TO NORTHWEST AND ALIGN. THIS FLOW
FEATURES A LONGER FETCH ACROSS LAKE ONTARIO AIMED AT THE SOUTHEAST
SHORES OF THE LAKE. HAVE INTRODUCED LIKELY POPS ACROSS
WAYNE...NORTHERN CAYUGA AND SOUTHERN OSWEGO COUNTIES THROUGH THE
OVERNIGHT. A MUCH SHORTER FETCH ACROSS LAKE ERIE HAS LED TO A TREND
OF LOWERING POPS TONIGHT BUT HOLDING IN THE CHANCE RANGE WITH SOME
UPSLOPE. OVERNIGHT LOWS WILL ONLY SLIP BACK INTO THE UPPER 50S NEAR
THE LAKE SHORES AND NEAR LAKE BANDS. LOW 50S EXPECTED WELL INLAND
FURTHEST FROM ANY LAKE INFLUENCES.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
THE UPPER LEVEL TROUGH WILL MOVE EAST INTO NEW ENGLAND THURSDAY AND
HIGH PRESSURE WILL BUILD ACROSS THE GREAT LAKES. THE CORE OF THE
COLD AIR ALOFT WILL STILL BE CROSSING WESTERN AND BOTH-CENTRAL NEW
YORK AND THIS COMBINED WITH NORTHWESTERLY FLOW AROUND THE EDGE OF
THE APPROACHING HIGH SHOULD KEEP A DECENT AMOUNT OF CLOUD COVER
AROUND THE AREA WITH HIGHS IN THE 60S.

SKIES SHOULD CLEAR OUT THURSDAY NIGHT AS THE HIGH MOVES OVERHEAD AND
LIGHT SOUTHERLY FLOW DEVELOPS. THIS WILL ALLOW FOR TEMPERATURES TO
FALL INTO THE 40S IN THE SOUTHERN TIER...WHERE VALLEY FOG WILL ALSO
BE LIKELY. AREAS ALONG THE LAKE PLAINS SHOULD REMAIN IN THE 50S.

HIGH PRESSURE OVERHEAD WILL ALLOW FOR THE WEEK TO CLOSE OUT ON A
SUNNY AND WARMER NOTE FRIDAY WITH HIGHS CLIMBING BACK INTO THE MID
70S. LIKEWISE INCREASING RIDGING ALOFT WILL PRODUCE WARMER READINGS
FRIDAY NIGHT WITH LOWS IN THE 50S TO AROUND 60 NEAR THE LAKES.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE FORECAST BECOMES A LITTLE MURKIER AS WE MOVE INTO THE WEEKEND
AND THE HIGH WEAKENS AND MOVES OFF TO THE EAST COAST. MODELS ARE IN
DISAGREEMENT REGARDING THE STRENGTH OF A SHORTWAVE THAT WILL WE
CROSSING THE CENTRAL GREAT LAKES. THE STRENGTH/AMPLITUDE OF THIS
TROUGH AND RESULTANT SURFACE LOW WILL SUBSEQUENTLY AFFECT DEGREE OF
SOUTHERLY RETURN FLOW THAT WE SEE ACROSS THE GREAT LAKES
SATURDAY...ALSO AFFECTING ANY SHOWER CHANCES. WHILE THE GFS IS
AGGRESSIVE IN DEVELOPING RETURN FLOW OF MOISTURE ACROSS THE
AREA...BROAD MODEL CONSENSUS IS AGAINST THIS AND WILL STICK TO A DRY
FORECAST FOR SATURDAY AND SUNDAY THOUGH WE SHOULD SEE THE WARMING
TREND CONTINUE AS THE HIGH MOVES OFF TO OUR EAST.

LOOKING AHEAD TO NEXT WEEK WE SHOULD SEE A RETURN OF SUMMERLIKE
CONDITIONS AS GUIDANCE IS CURRENTLY IN GOOD AGREEMENT ON THE
TRANSLATION OF A STRONG UPPER LEVEL RIDGE ACROSS THE AREA WITH
WARM...DRY...AND SUNNY WEATHER LASTING AT LEAST THROUGH TUESDAY.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
LAKE EFFECT SHOWERS ARE TRANSITIONING INTO SCATTERED DIURNAL SHOWERS
THIS AFTERNOON WITH THE ONSET OF PEAK DAYTIME MIXING. EXPECT
SCATTERED SHOWERS ACROSS MUCH OF THE AREA THROUGH EARLY EVENING. VFR
WILL PREVAIL...ALTHOUGH THE HEAVIER SHOWERS WILL PRODUCE BRIEF MVFR
CONDITIONS. SOME MVFR CIGS WILL ALSO LINGER ACROSS THE HIGHER
TERRAIN EAST OF LAKES ERIE AND ONTARIO WITH SOME ADDED LAKE EFFECT
MOISTURE.

AFTER SUNSET SHOWERS WILL TRANSITION BACK TO MORE LAKE EFFECT IN
NATURE...WITH THE MAJORITY OF THE SHOWERS FOCUSING EAST AND
SOUTHEAST OF LAKE ONTARIO AFTER 03Z AND TO A LESSER EXTENT ACROSS
THE WESTERN SOUTHERN TIER. CIGS WILL TEND TO LOWER TO MVFR OVERNIGHT
WITHIN THE LAKE EFFECT BANDS EAST OF BOTH LAKES AND ALSO ACROSS
HIGHER TERRAIN. SOME MVFR OR EVEN IFR VSBY MAY BRIEFLY DEVELOP IN
ANY HEAVIER LAKE EFFECT RAIN BANDS...ESPECIALLY SOUTHEAST OF LAKE
ONTARIO.

THURSDAY MORNING MVFR CIGS WILL BE AT THEIR MOST WIDESPREAD...
POSSIBLY EVEN ACROSS THE LAKE PLAINS AS WINDS BECOME NORTHWEST AND
INTRODUCE SOME UPSLOPE COMPONENT. SCATTERED SHOWERS SOUTHEAST OF THE
LAKES WILL END DURING THE AFTERNOON AS MUCH DRIER AIR BUILDS INTO
THE LOWER LAKES REGION. MVFR CIGS WILL IMPROVE TO VFR FIRST ACROSS
LOWER ELEVATIONS AROUND MIDDAY...THEN IMPROVE ACROSS HIGHER TERRAIN
BY MID AFTERNOON.

OUTLOOK...
FRIDAY AND SATURDAY...MAINLY VFR.
SUNDAY...MAINLY VFR WITH A CHANCE OF SHOWERS AND THUNDERSTORMS
AND ASSOCIATED BRIEF MVFR.
MONDAY...MAINLY VFR.

&&

.MARINE...
A WEST TO SOUTHWEST FLOW WILL PREVAIL TODAY...THEN WINDS
WILL SHIFT TO THE NORTHWEST BEHIND A SURFACE TROUGH TONIGHT AND
THURSDAY. WINDS/WAVES SHOULD GENERALLY STAY BELOW SMALL CRAFT
CRITERIA BUT IT WILL BE CLOSE AT TIMES.

THE COMBINATION OF COOL AIR ALOFT AND WARM LAKE TEMPERATURES WILL
CONTINUE TO BE FAVORABLE FOR WATERSPOUT DEVELOPMENT. THE BEST CHANCE
FOR WATERSPOUTS WILL BE THROUGH THIS MORNING...ESPECIALLY ALONG ANY
LAKE BOUNDARIES THAT FORM. HOWEVER...IN THIS ENVIRONMENT ANY SHOWER
COULD POTENTIALLY PRODUCE A WATERSPOUT.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.

&&

$$

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



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