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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBUF 160633
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
233 AM EDT SUN JUN 16 2013

.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE AND SURFACE COLD FRONT WILL BRING SHOWERS
AND THUNDERSTORMS AFTER SUNRISE THIS MORNING INTO THE EARLY
AFTERNOON. UPPER LEVEL TROUGHING WILL BUILD SOUTH ACROSS THE REGION
AND KEEP A CHANCE OF SHOWERS AND THUNDERSTORMS INTO TUESDAY. HIGH
PRESSURE AND DRIER WEATHER LOOKS TO RETURN BY MIDWEEK.

&&

.NEAR TERM /THROUGH TODAY/...
-- Changed Discussion --
MID-LEVEL CLOUDS CONTINUE TO BLANKET THE FORECAST AREA EARLY THIS
MORNING AHEAD OF A COMPLEX OF HEAVY RAIN AND THUNDERSTORMS WHICH IS
SHIFTING ACROSS MICHIGAN. THE STORM COMPLEX HAS FORMED BENEATH A
VIGOROUS UPPER LEVEL SHORTWAVE AND JUST AHEAD OF A SURFACE LOW AND
ASSOCIATED COLD FRONT. UPSTREAM OBSERVATIONS SHOW HEAVY RAINFALL IS
OCCURRING ACROSS CENTRAL AND NORTHERN MICHIGAN WITH MORE SCATTERED
CONVECTION ACROSS SOUTHERN MICHIGAN. KBUF RADAR IS SHOWING SOME
LIGHT WARM ADVECTION SHOWERS NOW LIFTING NORTH NEAR THE NY/PA STATE
LINE. JUST A LOW CHANCE OF A SHOWER HERE OTHERWISE EXPECT DRY
CONDITIONS UNTIL AROUND SUNRISE BASED ON RADAR EXTRAPOLATION OF
UPSTREAM CONVECTION AND SHORT TERM MODEL GUIDANCE.

A LOW LEVEL JET AHEAD OF THE COLD FRONT WILL INCREASE TO 40 PLUS
KNOTS WHICH WILL CONTINUE TO ADVECT A POOL OF HIGH MOISTURE
NORTHWARD OUT AHEAD OF THE FRONT. PRECIPITABLE WATER VALUES OFF
RECENT SPC MESOANALYSIS SHOWS 1.8 INCHES OVER CENTRAL ILLINOIS. THE
COMBINATION OF GOOD MOISTURE TRANSPORT AND LARGE SCALE ASCENT
ASSOCIATED WITH THE UPPER LEVEL SHORTWAVE WILL CONTINUE TO PRODUCE
WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS SHIFTING EASTWARD THIS
MORNING AND ARRIVING AROUND 12Z ACROSS WESTERN NY AND SHIFTING EAST
THROUGH THE MORNING.

00Z QPF FROM NAM/GFS/HRRR ARE SHOWING A MORE NORTHWARD TRACK OF THE
HEAVIER PRECIP THAN PREVIOUS RUNS WHICH SEEMS REASONABLE GIVEN THE
NEARLY DUE EASTWARD TRACK OF THE UPSTREAM THUNDERSTORM COMPLEX. AMOUNTS
WILL BE GREATEST ACROSS WESTERN NY RANGING FROM ABOUT A QUARTER TO A
THIRD OF AN INCH ACROSS THE SOUTHERN TIER TO AROUND THREE QUARTERS
OF AN INCH IN THE NORTHERN NIAGARA FRONTIER. NOT CONCERNED WITH
RENEWED HYDRO ISSUES WITH THESE AMOUNTS AS GAGES SHOW CREEKS AND
STREAMS CONTINUE ON THEIR WAY DOWN AND SHOULD BE ABLE TO ACCOMMODATE
THIS RAINFALL. HYDRO CONCERNS WOULD LIKELY ARISE IF AMOUNTS WERE TO
EXCEED AN INCH AND A HALF WHICH DOES NOT LOOK LIKELY UNLESS MORE
ELEVATED CONVECTION CAN DEVELOP.
-- End Changed Discussion --

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
DURING THE COURSE OF SUNDAY NIGHT...ANY SCATTERED SHOWERS/STORMS
LINGERING BEHIND THE MAIN SHORTWAVE SHOULD WIND DOWN DURING THE
EVENING...LEADING TO A GENERALLY DRY AND QUIET SECOND HALF OF THE
NIGHT. WITH INCREASED LOW LEVEL MOISTURE AND CLOUD COVER IN PLACE
FROM SUNDAY`S CONVECTION AND LITTLE TEMPERATURE CHANGE OF OUR
AIRMASS EXPECTED...WE SHOULD EXPERIENCE RELATIVELY MILD LOWS RANGING
FROM THE UPPER 50S ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER
AND NORTH COUNTRY TO THE LOWER 60S ELSEWHERE.

MONDAY AND MONDAY EVENING...EXPECT ANOTHER ROUND OF SCATTERED
CONVECTION TO DEVELOP ACROSS THE AREA WITH THE RETURN OF DIURNAL
HEATING AND THE EVENTUAL PASSAGE OF A COLD FRONT THAT WILL BE
SAGGING IN OUR DIRECTION FROM SOUTHERN ONTARIO/QUEBEC. HAVE THUS
CONTINUED WITH BROADBRUSH CHANCE POPS DURING THIS TIME FRAME...WITH
THE CONVECTION THEN EXPECTED TO DIMINISH FROM NORTH TO SOUTH
FOLLOWING THE PASSAGE OF THE FRONT MONDAY NIGHT. A FEW LEFTOVER
SHOWERS COULD LINGER ACROSS THE SOUTHERN TIER INTO TUESDAY GIVEN THE
CLOSER PROXIMITY OF THIS AREA TO THE FRONT AND ONE FINAL WEAK WAVE
OF LOW PRESSURE RIPPLING EAST ALONG IT...OTHERWISE TUESDAY SHOULD BE
DRY WITH INCREASING SUNSHINE FROM NORTH TO SOUTH AS STRONG CANADIAN
HIGH PRESSURE AND DRIER AIR BUILDS SOUTHEAST FROM THE UPPER LAKES.
THIS HIGH WILL THEN CONTINUE TO RIDGE ACROSS THE AREA TUESDAY
NIGHT...BRINGING MAINLY CLEAR SKIES AND BENIGN WEATHER TO CLOSE OUT
THE PERIOD.

AS FOR TEMPERATURES...EXPECT MONDAY TO BE A SEASONABLY WARM DAY AS
PARTIAL SUNSHINE AND 850 MB T`S OF +10C TO +13C LEAD TO FAIRLY
WIDESPREAD HIGHS IN THE MID TO UPPER 70S...WITH A FEW OF OUR NORMAL
WARM SPOTS IN THE GENESEE VALLEY AND FINGER LAKES POSSIBLY REACHING
OR BREAKING THE 80 DEGREE MARK. IN THE WAKE OF THE COLD FRONTAL
PASSAGE...A TREND BACK TOWARD COOLER WEATHER WILL THEN FOLLOW FOR
THE REST OF THE PERIOD...WITH HIGHS DROPPING BACK TO WITHIN A FEW
DEGREES OF 70 FOR TUESDAY...AND LOWS FALLING OFF TO THE MID-UPPER
40S INLAND/LOWER 50S ACROSS THE LAKE PLAINS TUESDAY NIGHT.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
IN THE EXTENDED PERIOD...LINGERING BROAD/RELATIVELY FLAT TROUGHING
ALOFT WILL GIVE WAY TO AN INCREASINGLY ZONAL FLOW ACROSS OUR
REGION...WHILE SURFACE HIGH PRESSURE SLOWLY DRIFTS FROM THE CENTRAL
GREAT LAKES AT THE START OF THE PERIOD TO A POSITION OFF THE EAST
COAST BY FRIDAY AND SATURDAY. WITH RESPECT TO TEMPERATURES...THIS
EVOLUTION IN THE PATTERN WILL RESULT IN SLIGHTLY BELOW NORMAL
TEMPERATURES ON WEDNESDAY MODERATING BACK TO NEAR NORMAL LEVELS BY
THURSDAY...THEN TO AT LEAST A BIT ABOVE NORMAL FOR BOTH FRIDAY AND
SATURDAY. MORE SPECIFICALLY...DAYTIME HIGHS WITHIN A FEW DEGREES OF
70 ON WEDNESDAY WILL WARM BACK TO AT LEAST THE LOWER 80S IN MOST
PLACES BY SATURDAY...AND POSSIBLY EVEN WARMER THAN THAT SHOULD THE
THE GFS/ECMWF-ADVERTISED 850 MB TEMPS OF +15C TO +18C ACTUALLY COME
TO FRUITION.

IN TERMS OF PRECIPITATION CHANCES...EXPECT THE WEDNESDAY TO FRIDAY
TIME FRAME TO BE MAINLY DRY COURTESY OF THE AFOREMENTIONED SURFACE
RIDGE...THOUGH A WEAK SYSTEM DROPPING THROUGH CENTRAL ONTARIO/QUEBEC
IN THE STILL-NORTHWESTERLY FLOW ALOFT COULD TOUCH OFF SOME ISOLATED
CONVECTION ACROSS THE SAINT LAWRENCE VALLEY/NORTH COUNTRY. BY
SATURDAY...INCREASING RETURN FLOW ON THE BACKSIDE OF THE RIDGE
SHOULD PUMP SOMEWHAT MORE HUMID AIR BACK INTO OUR REGION...AND THIS
COUPLED WITH DAYTIME HEATING AND THE APPROACH OF THE NEXT FRONTAL
SYSTEM SHOULD RESULT IN A MORE GENERAL CHANCE OF SOME SCATTERED
CONVECTION.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
WIDESPREAD VFR LEVEL BKN/OVC CIGS WILL CONTINUE THROUGH THE EARLY
MORNING IN ADVANCE OF A STORM SYSTEM CURRENTLY OVER CENTRAL
MICHIGAN. SOME LIGHT RAIN SHOWERS ARE LIFTING NORTH NEAR THE NY/PA
STATE LINE BUT THE MAIN IMPACT FOR THE FORECAST AREA WILL BE CLOSER
TO 12Z THIS MORNING WITH SHOWERS AND THUNDERSTORMS. CIGS AND VIS
WILL LOWER TO MVFR IN PRECIP/CONVECTION SPREADING FROM WEST TO EAST. VFR
CONDITIONS LOOK TO RETURN FOLLOWING THE PASSAGE OF CONVECTION AND
TRIGGERING COLD FRONT...FROM 20Z ONWARD.

OUTLOOK...
SUNDAY...VFR/MVFR. SHOWERS AND THUNDERSTORMS LIKELY.
MONDAY AND TUESDAY...MAINLY VFR WITH A CHANCE OF SHOWERS AND
THUNDERSTORMS.
WEDNESDAY THROUGH FRIDAY...VFR.
-- End Changed Discussion --

&&

.MARINE...
AN UPPER LEVEL DISTURBANCE AND SURFACE LOW WILL BRING SHOWERS AND
THUNDERSTORMS BEGINNING THIS MORNING WITH STRENGTHENING SOUTHWESTERLY
WINDS THAT MAY APPROACH SMALL CRAFT ADVISORY LEVELS. UNSETTLED
CONDITIONS WILL CONTINUE INTO TUESDAY THEN BY WEDNESDAY HIGH PRESSURE
WILL BUILD BACK ACROSS THE LOWER LAKES WITH TRANQUIL CONDITIONS.

&&

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

&&

$$

SYNOPSIS...SMITH
NEAR TERM...SMITH
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...SMITH
MARINE...SMITH