Severe Thunderstorm Warning 73, NWS Buffalo, NY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
754 PM EDT WED JUN 25 2008

.SYNOPSIS...
LOW PRESSURE WILL ADVANCE FROM THE UPPER GREAT LAKES...BRINGING A
CHANCE FOR SHOWERS AND THUNDERSTORMS TONIGHT AND THURSDAY. WEAK HIGH
PRESSURE AND GENERALLY FAIR WEATHER IS EXPECTED TO FOLLOW THURSDAY
NIGHT AND FRIDAY...THEN THE WEEKEND WILL BE UNSETTLED AND POSSIBLY
STORMY AS ANOTHER AREA OF LOW PRESSURE APPROACHES FROM THE UPPER
GREAT LAKES.

&&

.NEAR TERM /THROUGH THURSDAY/...
PRECIPITATION SPREADING OUT AHEAD OF THE REMNANTS OF AN MCS WILL
WEAKEN AS IT ENCOUNTERS THE RELATIVELY STABLE AIR OVER LAKE
ERIE...BUT IT IS ENOUGH FOR LIKELY POPS IN THE WESTERN SOUTHERN
TIER EARLY THIS EVENING AND CHANCE POPS IN THE NIAGARA FRONTIER.
OTHERWISE...EXPECT THE DEVELOPING CONVECTION OVER MICHIGAN TO
PERHAPS FORM ANOTHER MCS AND IMPACT OUR AREA MAINLY AFTER
MIDNIGHT, WHEN THE LOW LEVEL JET AND CONNECTIVELY INDUCED VORT MAX
TRACK ACROSS SOUTHERN NY AND NORTHERN PA. SINCE THESE SYSTEMS
TYPICALLY INTENSIFY OVERNIGHT...A PERIOD OF STEADY RAIN IS
POSSIBLE...ESPECIALLY AS PRECIPITABLE WATER VALUES RISE ABOVE 1.5
INCHES. STILL EXPECT THE HEAVIEST RAIN TO FALL ACROSS THE SOUTHERN
TIER WHICH WILL BE CLOSER TO THE MAIN CENTER OF THE MCS.

THE SHOWERS AND SCATTERED THUNDERSTORMS WILL TAPER OFF FROM WEST TO
EAST THURSDAY MORNING AS THE REMNANTS OF THE MCS PUSH ACROSS CENTRAL
NEW YORK. EXPECT THE AIR TO STABILIZE IN THE WAKE OF THE MORNING
CONVECTION...BUT THE LATEST INSTABILITY INDICES SUGGESTS THAT THE
ATMOSPHERE WILL RECOVER DURING THE AFTERNOON AS A WESTERLY FLOW OF
INCREASINGLY MOIST AIR ADVECTS INTO NEW YORK STATE. THE COMBINATION
OF INCREASING MOISTURE AND DAYTIME HEATING MAY ALLOW CAPES TO
APPROACH 1500 J/KG DURING THE AFTERNOON. ADDITIONAL LIFT WILL BE
PROVIDED BY AN 80 KNOT UPPER LEVEL JET STREAK THAT IS FORECAST TO
TRACK JUST NORTH OF NEW YORK STATE. THE FAVORABLE THERMODYNAMICS AND
UPPER LEVEL SUPPORT MAY RESULT IN SOME ACTIVE CONVECTION IN THE
UNIDIRECTIONAL FLOW...ESPECIALLY ALONG THE BOUNDARY OF THE LAKE ERIE
BREEZE.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
CONVECTION THAT DEVELOPS DURING THE AFTERNOON THURSDAY WILL LINGER
FOR AWHILE INTO THE EVENING HOURS...BEFORE DIMINISHING WITH LACK
OF HEATING. MODELS SUGGESTING THERE WILL BE A BREAK IN THE
CONVECTIVE ACTIVITY THURSDAY NIGHT AND FRIDAY...AS WEAK HIGH
PRESSURE LOOKS TO BRIEFLY BUILD ACROSS THE AREA. THINK THAT MOST
OF THE AREA WILL BE DRY THROUGH THIS TIME PERIOD...BUT BOTH THE
12Z NAM AND GFS SUGGESTING THAT A WEAK UPPER WAVE WILL PUSH SOUTH
OF THE AREA ALONG FRONTAL BOUNDARY POISED JUST TO THE SOUTH OF THE
AREA WITH THE POTENTIAL FOR SOME REDEVELOPMENT OF CONVECTION BY
FRIDAY AFTERNOON ALONG THE SOUTHERN TIER...IN AREA OF GREATER
MOISTURE AND INSTABILITY AXES. POTENT UPPER TROUGH WILL CONTINUE
TO AMPLIFY SOUTHEASTWARD INTO THE UPPER GREAT LAKES SATURDAY.
ASSOCIATED COLD FRONT LOOKS TO WORK INTO THE AREA LATE IN THE DAY
SATURDAY...AND WITH A VERY MOIST/UNSTABLE AIRMASS LIKELY TO BE IN
PLACE AHEAD OF THE FRONT...WE COULD BE LOOK AT THE POTENTIAL FOR
SOME ACTIVE CONVECTION LATE IN THE DAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE MEDIUM RANGE PERIOD CONTINUES TO LOOK RATHER UNSETTLED AS
OPERATIONAL MODELS AND MEDIUM RANGE ENSEMBLES CONTINUING TO SUGGEST
A LARGE SCALE PATTERN AMPLIFICATION THROUGH THE WEEKEND...AS A
CUTOFF LOW MOVES INTO ONTARIO/UPPER GREAT LAKES AT THE BEGINNING OF
THE PERIOD...THEN REMAINING OVER THE REGION THROUGH THE WEEKEND.
THIS CUTOFF LOOKS TO LIFT AWAY EARLY NEXT WEEK...HOWEVER THE
LONGWAVE TROUGH IS SHOWN TO PERSIST ACROSS THE NORTHEAST CONUS
THROUGH THE END OF THE PERIOD.

IN A PATTERN LIKE THIS...IT WILL BE DIFFICULT TO PINPOINT THE MOST
ACTIVITY WEATHER PERIOD...BUT IT DOES LOOK LIKE THERE WILL BE NO
SUSTAINED DRY WEATHER. THE MOST ACTIVE PERIOD COULD BE THE SATURDAY
NIGHT AND SUNDAY TIME FRAME AS A SURFACE FRONTAL BOUNDARY WORKS
THROUGH THE AREA WITH PRECIPITABLE WATER VALUES SURGING TO 1.5-2.0
INCHES...ABOUT 1-2 STANDARD DEVIATIONS ABOVE NORMAL AHEAD OF THE
BOUNDARY. EVEN AFTER THE UPPER LOW AND ASSOCIATED COLD POOL LIFTS
AWAY THE UPPER LEVEL TROUGHING WILL REMAIN AND WILL RESULT IN A
CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY AND TUESDAY.
MODEL SUGGESTION IS THAT THE PATTERN COULD BECOME MORE PROGRESSIVE
BY THE END OF THE PERIOD AND WE MAY SEE LESS OF A THREAT FOR
CONVECTION TUESDAY NIGHT AND WEDNESDAY...HOWEVER WE PREFER TO LEAVE
A CONTINUED MENTION OF SHOWERS/THUNDERSTORMS IN THE FORECAST FOR
NOW WITH THE AREA IN A FAVORABLE WEST NORTHWEST FLOW PATTERN ALOFT.

THE OVERALL PATTERN WOULD SUGGEST THAT TEMPERATURES DURING THE
PERIOD WILL LIKELY BE AT OR BELOW NORMAL...ESPECIALLY DURING THE
MONDAY TIME FRAME AS 850 MB TEMPERATURES DROP TO +8C TO +10C...
ABOUT 1 STANDARD DEVIATION BELOW NORMAL.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
HBUT MID AND HIGH LEVEL CLOUDS ASSOCIATED WITH THE APPROACHING
CONVECTION WILL SPREAD EAST ACROSS THE AREA THIS EVENING.
CONVECTION IS MOVING EAST AHEAD OF DEVELOPING MCS, WITH A CHANCE
OF THE FIRST ROUND OF RAIN SPREADING SOUTH OF BUFFALO DURING THE
LATE EVENING WITH SPOTTY MVFR CONDITIONS. EXPECT MAINLY VFR
CONDITIONS MOST OF THE NIGHT, BUT OCCASIONAL IFR VISIBILITY AND
MVFR CEILINGS IN STRONGER THUNDERSTORMS OVERNIGHT MAINLY IN THE
SOUTHERN TIER. THERE WILL BE A PERIOD OF MVFR CEILINGS FOR AWHILE
LATE TONIGHT AND WEDNESDAY MORNING IN THE WAKE OF THE MCS AND
CONVECTION.

SHOWERS AND THUNDERSTORMS WILL TAPER OFF FROM WEST TO EAST
WEDNESDAY MORNING...LIFTING TO VFR CONDITIONS. RATHER MOIST AND
INCREASINGLY UNSTABLE AIR WILL THEN SET UP ACROSS THE AREA
WEDNESDAY AFTERNOON. THIS WILL BRING ANOTHER CHANCE FOR
CONVECTION...ESPECIALLY ALONG THE PERIPHERY OF THE LAKE ERIE
BREEZE.

OUTLOOK...
FRIDAY...VFR.
SATURDAY...VFR. CHC SHWRS.
SUNDAY AND MONDAY...VFR/MVFR. CHC TSTMS.

&&

.MARINE...
NO MARINE HEADLINES WILL BE NECESSARY THROUGH THE WEEKEND.
HOWEVER LATE TONIGHT AND THURSDAY...SOUTHWEST WINDS WILL INCREASE AS
IN ADVANCE OF LOW PRESSURE TRACINGS EASTWARD...JUST NORTH OF THE
LOWER LAKES OR ACROSS LAKE ONTARIO. WAVES WILL INCREASE ON THE EAST
END OF LAKE ERIE DURING THIS PERIOD WITH HEIGHTS TO 4 FEET POSSIBLE.
MARINERS SHOULD BE ON THE ALERT FOR POSSIBLE STRONG THUNDERSTORMS
LATE TONIGHT AND THURSDAY ALSO SATURDAY NIGHT AND SUNDAY.

&&

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

&&

SYNOPSIS...TMA
NEAR TERM...APB/TJP
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...APB/TJP
MARINE...TMA

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BUFFALO NY
540 AM EDT WED JUN 25 2008

NYZ001>008-010>014-019>021-085-260945-
NIAGARA-ORLEANS-MONROE-WAYNE-NORTHERN CAYUGA-OSWEGO-JEFFERSON-LEWIS-
NORTHERN ERIE-GENESEE-WYOMING-LIVINGSTON-ONTARIO-CHAUTAUQUA-
CATTARAUGUS-ALLEGANY-SOUTHERN ERIE-
540 AM EDT WED JUN 25 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND NORTH CENTRAL NEW
YORK.

.DAY ONE...TODAY AND TONIGHT

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THURSDAY. PRIMARY
HAZARDS WOULD BE DAMAGING WINDS AND LARGE HAIL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

THIS PRODUCT...ALONG WITH OTHER WATCHES...WARNINGS...ADVISORIES...
AND STATEMENTS ISSUED BY THE NATIONAL WEATHER SERVICE OFFICE IN
BUFFALO CAN BE FOUND ON THE INTERNET AT HTTP://WWW.WEATHER.GOV/BUF

LEZ020-040-041-LOZ042>045-062>065-SLZ022-024-260945-
UPPER NIAGARA RIVER AND BUFFALO HARBOR-
LAKE ERIE NEARSHORE WATERS FROM RIPLEY TO DUNKIRK-
LAKE ERIE NEARSHORE WATERS FROM DUNKIRK TO BUFFALO-
LAKE ONTARIO NEARSHORE WATERS FROM THE NIAGARA RIVER TO HAMLIN BEACH-
LAKE ONTARIO NEARSHORE WATERS FROM HAMLIN BEACH TO SODUS BAY-
LAKE ONTARIO NEARSHORE WATERS FROM SODUS BAY TO MEXICO BAY-
LAKE ONTARIO NEARSHORE WATERS FROM MEXICO BAY TO THE SAINT LAWRENCE
RIVER-
LAKE ONTARIO OPEN WATERS FROM THE NIAGARA RIVER TO HAMLIN BEACH-
LAKE ONTARIO OPEN WATERS FROM HAMLIN BEACH TO SODUS BAY-
LAKE ONTARIO OPEN WATERS FROM SODUS BAY TO MEXICO BAY-
LAKE ONTARIO OPEN WATERS FROM MEXICO BAY TO THE SAINT LAWRENCE RIVER-
SAINT LAWRENCE RIVER FROM CAPE VINCENT TO OGDENSBURG-
SAINT LAWRENCE RIVER FROM OGDENSBURG TO SAINT REGIS-
540 AM EDT WED JUN 25 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF LAKE ERIE...LAKE
ONTARIO AND SAINT LAWRENCE RIVER.

.DAY ONE...TODAY AND TONIGHT

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THURSDAY. PRIMARY
HAZARDS WOULD BE DAMAGING WINDS AND LARGE HAIL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

THIS PRODUCT...ALONG WITH OTHER WATCHES...WARNINGS...ADVISORIES...
AND STATEMENTS ISSUED BY THE NATIONAL WEATHER SERVICE OFFICE IN
BUFFALO CAN BE FOUND ON THE INTERNET AT HTTP://WWW.WEATHER.GOV/BUF

SAGE