Area Forecast Discussion
Issued by NWS Buffalo, NY

Home | Current Version | Previous Version | Graphics & Text | 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 300624
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
224 AM EDT SAT APR 30 2016

.SYNOPSIS...
FOLLOWING THE PASSAGE OF AN UPPER LEVEL TROUGH OF LOW PRESSURE...HIGH
PRESSURE BUILDS ACROSS THE REGION TONIGHT RESULTING IN A DRY START
TO THE WEEKEND BEFORE ANOTHER TROUGH OF LOW PRESSURE DEVELOPS
ACROSS THE AREA ON SUNDAY...BRINGING SHOWERS TO MOST AREAS.
TEMPERATURES THROUGH THE WEEKEND WILL RUN SLIGHTLY COOLER THAN
AVERAGE.

&&

.NEAR TERM /THROUGH TODAY/...
MOST IF NOT ALL SHOWERS HAVE COME TO AN END ACROSS THE FORECAST AREA
AS OF 0230Z. WILL REDUCE AND ELIMINATE POPS FOR TONIGHT. IN THE WAKE
OF A COOL RAINY DAY...CLEARING SKIES ACROSS THE SOUTHERN TIER TO
UPPER GENESEE VALLEY HAVE LEAD TO FORMATION OF LOW CLOUD DECK AND
AREAS OF FOG. HAVE UPDATED THAT AREA TO REFLECT THE CLOUDS AND FOG
THROUGH 12Z-13Z ON SATURDAY.

A DRY NIGHT AND SATURDAY ARE IN STORE BEHIND THE WAVE PASSAGE AS
RISING HEIGHTS ALOFT AND HIGH PRESSURE NOSING IN FROM THE NORTH AT
THE SURFACE KEEP FAIR WEATHER IN PLACE. CLEARING CLOUD COVER...
MAINLY ALONG AND NORTH/EAST OF LAKE ONTARIO WILL ALLOW FOR SOME
RADIATIONAL COOLING OVERNIGHT. LOW TEMPERATURES WILL RUN SLIGHTLY
BELOW SEASONAL NORMALS... IN THE 30S TO LOW 30S IN THE NORTH
COUNTRY... WHICH WILL SEE THE MOST CLEARING.

ON SATURDAY... A WARM FRONT WILL APPROACH THE REGION FROM THE
SOUTHWEST LATE IN THE DAY AS A WAVE EJECTS OUT OF THE CENTRAL PLAINS
TOWARD THE OHIO VALLEY. EXPECT INCREASING CLOUD COVER FROM SOUTHWEST
TO NORTHEAST THROUGH THE AFTERNOON... HOWEVER THE DRY FEED OF AIR
FROM THE SURFACE HIGH TO OUR NORTH WILL HELP TO ERODE AN INITIAL
SHOWERS THAT APPROACH THE REGION. THUS WILL MAINTAIN A DRY FORECAST
THROUGH THE DAYTIME HOURS ON SATURDAY... WITH JUST INCREASING CLOUD
COVER AND VIRGA INTO THE LATE AFTERNOON... ESPECIALLY TOWARD
SOUTHWEST NY. HIGH TEMPERATURES WILL RUN NEAR NORMAL... WITH HIGHS
IN THE U50S TO L60S.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
SATURDAY NIGHT AND SUNDAY...ANOTHER WAVE OF LOW PRESSURE WILL
RIPPLE NORTHEASTWARD ACROSS THE OHIO VALLEY AND INTO NEW YORK/
PENNSYLVANIA. A SURGE OF WARM AIR ADVECTION ASSOCIATED WITH BOTH
THIS FEATURE AND AN ATTENDANT LOW LEVEL JET SEGMENT WILL SPREAD
INCREASING AMOUNTS OF MOISTURE AND LARGE-SCALE ASCENT INTO OUR
REGION SATURDAY NIGHT...WITH THE FORCING PEAKING OVER OUR REGION
LATER SATURDAY NIGHT/SUNDAY MORNING... THEN GRADUALLY WEAKENING
FROM SOUTHWEST TO NORTHEAST DURING THE DAY AS THE LOW LEVEL JET
SEGMENT SLIDES OFF INTO EASTERN NEW YORK.

ALL OF THIS WILL RESULT IN CLOUDS RAPIDLY INCREASING ACROSS OUR
REGION SATURDAY NIGHT AND THEN REMAINING IN PLACE THROUGH SUNDAY...
ALONG WITH A SLUG OF RAIN WORKING ACROSS OUR REGION...WITH THE
BULK OF THE RAIN FALLING BETWEEN ABOUT MIDNIGHT SATURDAY NIGHT
AND EARLY SUNDAY AFTERNOON. AT THIS POINT...THIS SYSTEM LOOKS
IMPRESSIVE ENOUGH TO WARRANT BOOSTING POPS UP INTO THE CATEGORICAL
RANGE...WITH THE HIGHEST VALUES ACCOMPANYING THE APPROACH AND
PASSAGE OF THE AFOREMENTIONED LOW LEVEL JET SEGMENT. RAINFALL
AMOUNTS ALSO LOOK AS IF THEY WILL BE PRETTY RESPECTABLE JUDGING
FROM A 12Z MODEL QPF CONSENSUS...WHICH SUGGESTS THE POTENTIAL FOR
AS MUCH AS A THIRD TO TWO THIRDS OF AN INCH OF RAINFALL BETWEEN
SATURDAY NIGHT AND SUNDAY...WITH THE HIGHEST AMOUNTS MOST LIKELY
FOCUSED ACROSS THE SOUTHERN TIER. WITH THE EXPECTED CLOUD COVER
AND RAINFALL...TEMPS WILL GENERALLY RANGE A BIT ABOVE AVERAGE
SATURDAY NIGHT AND A BIT BELOW AVERAGE ON SUNDAY...WITH LOWS
MOSTLY IN THE MID 40S SATURDAY NIGHT FOLLOWED BY HIGHS IN THE
LOWER TO MID 50S ON SUNDAY.

SUNDAY NIGHT AND MONDAY...THE VARIOUS GUIDANCE PACKAGES APPEAR
TO BE COMING INTO BETTER AGREEMENT ON THE IDEA OF A SECONDARY
SURFACE WAVE FOLLOWING QUICKLY ON THE HEELS OF THE FIRST...ALBEIT
ON A SLIGHTLY MORE SOUTHERLY TRACK ACROSS THE OHIO VALLEY AND MID
ATLANTIC STATES. THIS FEATURE WILL LIKELY BRING THE LIKELIHOOD OF
ANOTHER ROUND OF RAIN TO MOST AREAS /WITH THE POSSIBLE EXCEPTION
OF PORTIONS OF THE NIAGARA FRONTIER/ LATER SUNDAY NIGHT AND EARLY
MONDAY...WITH THE RAIN THEN TAPERING OFF FROM WEST TO EAST THROUGH
THE BALANCE OF THE DAY AS THIS SECOND WAVE DEPARTS TO THE EAST...
AND AS HIGH PRESSURE AND DRIER AIR BUILDS EASTWARD FROM THE UPPER
GREAT LAKES. TEMPERATURE-WISE...LOWS SUNDAY NIGHT SHOULD MOSTLY
RANGE NEAR NORMAL LEVELS IN THE LOWER 40S... WITH HIGHS ON MONDAY
AGAIN HELD BACK A BIT BY LINGERING CLOUD COVER AND A COOL NORTHERLY
FLOW...WHICH SHOULD CONSPIRE TO KEEP READINGS CONFINED TO THE MID
50S.

FINALLY FOR MONDAY NIGHT AND TUESDAY...THE AFOREMENTIONED SURFACE
RIDGE WILL BUILD DIRECTLY OVERHEAD AND BRING A RETURN TO FAIR AND
DRY WEATHER TO CLOSE OUT THIS PERIOD...WITH ATTENDANT DRIER AIR
AND SUBSIDENCE ALSO LEADING TO A RETURN TO MOSTLY SUNNY SKIES IN
TIME FOR TUESDAY. MEANWHILE...TEMPERATURES WILL RETURN TO RIGHT
AROUND AVERAGE LEVELS FOR EARLY MAY...WITH LOWS MOSTLY WITHIN A
FEW DEGREES OF 40 MONDAY NIGHT FOLLOWED BY HIGHS IN THE LOWER TO
MID 60S ON TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
A HIGHLY AMPLIFIED PATTERN WILL BE IN PLACE ACROSS THE COUNTRY
DURING THIS PERIOD...AS A STRONG RIDGE WILL BE FOUND OVER THE
WESTERN HALF OF THE CONUS WHILE A DEEPENING TROUGH IN THE EAST WILL
EVENTUALLY EVOLVE INTO A CLOSED LOW OVER THE MID ATLANTIC STATES.
UNFORTUNATELY...THIS PATTERN IS NOT CONDUCIVE FOR WARM WEATHER
ACROSS THE GREAT LAKES REGION. H85 TEMPS FOR OUR REGION WILL
GENERALLY BE IN THE LOWER SINGLE DIGITS...AND THIS WILL EQUATE TO
TEMPERATURES THAT WILL AVERAGE NEAR OR JUST BELOW NORMAL EARLY MAY
VALUES.

IN TERMS OF PRECIPITATION...THE VAST MAJORITY OF THIS TIME PERIOD
WILL BE RAINFREE. THE BROAD BRUSH DETAILS...

HIGH PRESSURE OVER THE LOWER GREAT LAKES TUESDAY NIGHT WILL
GRUDGINGLY GIVE WAY TO A COLD FRONT WEDNESDAY AFTERNOON AND NIGHT.
THE PASSAGE OF THIS FEATURE WILL PRODUCE SCATTERED SHOWERS OVER THE
REGION...THEN THE FRONT WILL BECOME ABSORBED WITHIN A COMPLEX
COASTAL STORM SYSTEM LATER THURSDAY AND FRIDAY. THIS WILL FOCUS THE
BULK OF THE RAIN AND UNSETTLED WEATHER CLOSER TO THE COAST...WITH
THE BACK EDGE OF THE INCLEMENT WEATHER LIKELY BEING FOUND OVER
EASTERN SECTIONS OF NEW YORK AND PENNSYLVANIA.

A LOOK FURTHER DOWN THE ROAD AT NEXT WEEKEND...
BOTH THE GFS AND ECMWF BASED ENSEMBLES ARE IN FAIRLY GOOD AGREEMENT
THAT TROUGHING WILL REMAIN IN PLACE OVER THE NORTHEASTERN PORTION OF
THE COUNTRY. THIS SHOULD KEEP RELATIVELY COOL CONDITIONS IN PLACE
WITH FAIRLY HIGH CONFIDENCE OF BELOW NORMAL TEMPS. AVERAGE
TEMPERATURES FOR THIS TIME OF YEAR RANGE FROM THE MID 60S FOR
AFTERNOON HIGHS TO THE LOW-MID 40S FOR OVERNIGHT LOWS.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...

SHOWERS HAVE ENDED ACROSS THE FORECAST AREA AND UPPER LEVEL RIDGING
AND ACCOMPANYING WEAK SURFACE RIDGING ARE MOVING INTO THE LOWER
GREAT LAKES. HOWEVER...A LAYER OF MOISTURE REMAINS TRAPPED
UNDERNEATH THE APPROACHING HIGH AND IS PRODUCING VFR CIGS AROUND
3500-4000FT ACROSS MUCH OF THE FORECAST AREA WITH THE EXCEPTION OF
THE NORTH COUNTRY. THE LINGERING MOISTURE IS PARTICULARLY ACUTE
ACROSS THE SOUTHERN TIER WHERE THE HEAVIEST RAIN FELL FRI EVENING
AND WIDESPREAD IFR CONDITIONS WITH AREAS OF FOG CAN BE FOUND. EXPECT
IFR CONDITIONS TO PERSIST THERE THROUGH 12-15Z BEFORE CIGS LIFT AND
FOG DISSIPATES.

ELSEWHERE...EXPECT VFR CIGS TO LINGER SOUTH OF LAKE ONTARIO THROUGH
MUCH OF THE DAY ON SATURDAY AS MOISTURE REMAINS TRAPPED UNDERNEATH
THE AFOREMENTIONED RIDGING ALOFT. DRIER AIR MAY WORK ITS WAY IN FROM
THE NORTHEAST...ALLOWING CIGS TO SCATTER OUT FOR A TIME AFTER 18Z
FROM KIAG-KROC-KFZY...HOWEVER EXPECT MID/HIGH CLOUDS TO INCREASE
FROM WEST TO EAST FROM 00Z ONWARDS AS A WARM FRONT APPROACHES THE
REGION. THIS WILL LIKELY RESULT IN A RETURN TO IFR CONDITIONS ACROSS
THE SOUTHERN TIER TOWARDS THE END OF THE FORECAST PERIOD AS RAIN
WORKS ITS WAY NORTH INTO THE AREA SAT NIGHT.

CONDITIONS IN THE NORTH COUNTRY SHOULD REMAIN LARGELY CLOUD-FREE
THROUGH MUCH OF THE OVERNIGHT AND THROUGH THE DAY SATURDAY AS
SATELLITE IMAGERY INDICATES THE BULK OF THE LINGERING MOISTURE IS
SOUTH OF THE AREA AND GUIDANCE INDICATES THAT EAST-NORTHEASTERLY
FLOW SHOULD ENSURE THIS REMAINS THE CASE THROUGH THE PERIOD.
MID/HIGH CLOUDS WILL MAKE IT IN LATE IN THE PERIOD HOWEVER.

OUTLOOK...

SATURDAY NIGHT AND SUNDAY...VFR/MVFR WITH RAIN LIKELY. IFR CONDITIONS
LIKELY ACROSS THE SOUTHERN TIER.
MONDAY...VFR/MVFR WITH A CHANCE OF SHOWERS.
TUESDAY...MAINLY VFR.
WEDNESDAY AND THURSDAY...VFR/MVFR WITH A CHANCE OF SHOWERS.

&&

.MARINE...
A BROAD AREA OF HIGH PRESSURE MOVING ACROSS THE REGION WILL MAINTAIN
TRANQUIL CONDITIONS ON THE LAKES THROUGH TODAY AND INTO SATURDAY
EVENING. EAST-NORTHEASTERLY FLOW WILL FRESHEN AS A LOW PRESSURE
SYSTEM TRACKING OUT OF THE MISSISSIPPI VALLEY TRACKS TOWARDS THE
LOWER GREAT LAKES. WITH EAST-NORTHEASTERLY WINDS STRENGTHENING TO
20KTS...WAVES WILL BUILD IN EXCESS OF 4FT ON THE EAST END OF LAKE
ONTARIO SUNDAY MORNING AND SMALL CRAFT ADVISORIES ARE LIKELY.

WINDS AND WAVES WILL GRADUALLY DIMINISH SUNDAY NIGHT AS THE LOW
TRACKS ACROSS THE LAKES. HIGH PRESSURE WILL THEN RETURN TO THE LAKES
INT HE WAKE OF THE DEPARTING LOW MONDAY NIGHT INTO TUESDAY.

&&

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

&&

$$

SYNOPSIS...CHURCH/WCH
NEAR TERM...CHURCH/WCH
SHORT TERM...JJR
LONG TERM...RSH
AVIATION...WOOD
MARINE...WOOD


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