Hail and Damaging Winds in New York, July 25, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
316 PM EDT SAT JUL 25 2009

.SYNOPSIS...
LOW PRESSURE OVER THE CENTRAL GREAT LAKES WILL TRACK NORTHEAST INTO
ONTARIO AND PUSH A COLD FRONT INTO THE AREA TONIGHT...WHICH WILL BE
ACCOMPANIED BY SOME SHOWERS AND THUNDERSTORMS. A CHANCE OF SHOWERS
AND THUNDERSTORMS WILL THEN LINGER ACROSS THE AREA ON SUNDAY AS THE
FRONT CONTINUES TO PUSH SLOWLY TO THE EAST...THEN CONDITIONS WILL
BECOME SOMEWHAT LESS UNSETTLED FOR MONDAY AND TUESDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
3 PM UPDATE...CONVECTION BEGINNING TO FIRE IN SEVERAL AREAS AT MID
AFTERNOON...ALONG SOUTHERN AND EASTERN EDGE OF REMNANTS OF EARLIER
BOOKEND VORTEX ASSOCIATED WITH DYING MCV WHICH HAS WORKED UP INTO
SOUTHERN ONTARIO JUST TO OUR WEST...AND MORE IMPRESSIVELY OVER
WESTERN PA AHEAD OF A WIND SHIFT BOUNDARY WHICH EXTENDED FROM CHAUT
CO NY TO EASTERN OHIO AT 19Z. OVERALL...THERE WILL AN AXIS ABOUT 40
MILES WIDE WHICH WILL SEE RAPID DEVELOPMENT AS IT DRIFTS EAST
DURING THE REST OF AFTERNOON AND EARLY THIS EVENING. THIS AXIS
SHOULD CLEAR BUF/IAG BY 5 PM AND CENTER ON GENESEE VALLEY AROUND 22Z
AND MOVE OFF TO OUR ERN LK ONTARIO COUNTIES AROUND MID EVENING.
BEGINNING TO THINK THIS MAY BE OUR ONLY CONCERN FOR ANY SEVERE WX.
ALSO KEEPING AN EYE ON A NARROW LINE OF CONVECTION WHICH WAS ALONG
THE COLD FRONT IN SE MICH NEAR DETROIT. IT DOES APPEAR THAT THE
CLOUDS FROM THE EARLIER MCV HAVE DIMINISHED THE INSTABILITY AND
REDUCED THE THREAT OF SVR WX THIS FAR NORTH...BUT WILL STILL NEED TO
MONITOR SITUATION THROUGH 02Z OR SO AS MAX LL JET TRAVERSES AREA AND
JUST TO SOUTH.

WILL THEREFORE PLAY AN INCREASE IN POPS FOR NEXT 6 HOURS FROM WEST
TO EAST AS THE AXIS OF MAXIMUM INSTABILITY MOVES ACROSS THE
AREA...LOWER THEM A BIT EARLY THIS EVE...THEN RAMP UP TO A BRIEF
PERIOD OF LIKELY POPS TO ACCOUNT FOR ANYTHING THAT MAKES IT EAST
FROM MICHIGAN...ALTHOUGH THIS IS NOT A CERTAINTY BY ANY MEANS.

MORE CONFIDENT ABOUT THE PERIOD OVERNIGHT INTO SUNDAY AS
BOUNDARY/FRONT SHOULD BE EAST OF OUR CWA BY 12Z SUNDAY. WILL LOWER
POPS AFT MIDNIGHT WEST AND TWD DAYBREAK EAST...WILL HOLD OFF ON FOG
IN THE GRIDS DUE TO LINGERING CLOUD BUT WILL BE AN ISSUE IF IT
CLEARS.

SUNDAY LOOKS SIMILAR TO FRIDAY...WITH A CYCLONIC FLOW AROUND THE
SEMI-PERMANENT UPPER LOW WHICH WILL LIE ACROSS THE UPPER LAKES. IT
WILL BE DRIER BUT STILL SOME DECENT INSTABILITY DURING THE
AFTERNOON. WITH CAPES OF 500-1000J/KG. LAKE SHADOWS SHOULD COME
INTO PLAY...WITH BEST CHC OF SHOWERS ALONG LK BREEZE BOUNDARIES
(NIAG PENIN/S AND E OF BUF AND ROC) AND LOWEST CHC IN SHADOWS IMMED
BUF/ART AREAS. NOT A BAD DAY. 850 MB TEMPS OF 12-13C SUPPORT
75-80...COOLEST DOWNWIND OF THE LAKES. WILL LEAN MORE TWD LOWER MET
POPS...20 IN SHADOWS TO 40 INLAND.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
ALL OF SUNDAY AFTERNOONS CONVECTION SHOULD DIE OUT FAIRLY
QUICKLY WITH THE DEPARTURE OF THE LINGERING FRONT AND THE LOSS OF
DAYTIME HEATING SUNDAY EVENING...WITH A GENERALLY DRY PERIOD
EXPECTED FOR THE REMAINDER OF SUNDAY NIGHT AND MONDAY MORNING AS
WEAK RIDGING BUILDS OVERHEAD.

DURING MONDAY AFTERNOON...ANOTHER SHORTWAVE IS EXPECTED TO TRACK
ACROSS NEW YORK STATE. WITH A GOOD AMOUNT OF DIURNAL HEATING
EXPECTED AND STILL-COOL TEMPERATURES LINGERING ALOFT...ENOUGH
INSTABILITY SHOULD BE PRESENT FOR THIS SHORTWAVE TO KICK OFF SOME
MORE SCATTERED CONVECTION...THOUGH THIS SHOULD BE LESS WIDESPREAD
THAN THAT SEEN OVER THE PRECEDING FEW DAYS. AS SUCH...WILL CONTINUE
TO COVER THE CONVECTIVE POTENTIAL WITH LOW CHANCE POPS FOR MONDAY
AFTERNOON...WITH THE ACTIVITY THEN DYING OUT FAIRLY QUICKLY ONCE
AGAIN MONDAY EVENING WITH THE LOSS OF HEATING.

AT THIS POINT...TUESDAY LOOKS TO BE A PRETTY DECENT AND GENERALLY
DRY DAY...WITH THE HEIGHTS ALOFT ON A SLOW RISE AND THE AREA
SITUATED UNDER SURFACE WEAK RIDGING BETWEEN A LOW OFF THE EAST COAST
AND THE NEXT FRONTAL BOUNDARY DROPPING SOUTHEAST ACROSS THE WESTERN
AND CENTRAL GREAT LAKES. WILL KEEP POPS FOR THIS PERIOD CONFINED TO
THE SLIGHT CHANCE RANGE OR LESS...AND INDICATE WIDESPREAD TEMPS IN
THE LOW-MID 80S GIVEN 850 MB TEMPS CLIMBING INTO THE +14C TO +16C
RANGE...FOR ONCE A TYPICAL LATE JULY DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
DURING THIS PERIOD...THE PERSISTENT UPPER LOW OVER THE GREAT LAKES
REGION IS EXPECTED TO RETROGRADE A LITTLE BIT FURTHER TO THE WEST IN
RESPONSE TO A BUILDING RIDGE OVER THE EASTERN PACIFIC...WITH THE
MEAN POSITION OF THE UPPER TROUGH AXIS MIGRATING FROM THE CENTRAL
LAKES TO THE WESTERN LAKES/UPPER MIDWEST. THIS WILL ALLOW FOR
GRADUAL HEIGHT RISES OVER OUR AREA AS THE WESTERN ATLANTIC
SUBTROPICAL RIDGE SLOWLY BUILDS FURTHER WESTWARD IN RESPONSE TO THE
RETROGRADING LOW...WITH THE UPPER LEVEL FLOW TENDING MORE THEN
SOUTHWESTERLY WITH TIME. AS A RESULT...TEMPERATURES DURING THIS
PERIOD SHOULD BE CLOSE TO OR EVEN A LITTLE ABOVE NORMAL MIDSUMMER
LEVELS.

AS FOR RAIN CHANCES...THE RELATIVELY QUIET CONDITIONS AT THE END OF
THE SHORT TERM PERIOD SHOULD QUICKLY BECOME MUCH MORE UNSETTLED FOR
WEDNESDAY AND WEDNESDAY NIGHT AS A WEAKENING FRONTAL BOUNDARY SLIDES
SOUTH INTO OUR REGION...THEN EITHER SLOWS MARKEDLY OR BECOMES
STATIONARY AS ONE OR MORE SHORTWAVE TROUGHS WORK THROUGH IN THE
SOUTHWESTERLY FLOW ALOFT...AND THEIR ATTENDANT SURFACE FEATURES
RIPPLE NORTHEAST ALONG THE SLOW-MOVING FRONTAL BOUNDARY. LATTER
PORTIONS OF THE PERIOD SHOULD THEN FEATURE A GRADUAL RETURN TO DRIER
CONDITIONS AS A WEAK SURFACE RIDGE BUILDS ACROSS THE GREAT LAKES AND
NORTHEAST...AND SLOWLY SHUNTS THE SURFACE BOUNDARY FARTHER TO THE
SOUTH.

GIVEN THE RATHER WET-LOOKING SYNOPTIC PATTERN EXPECTED FOR
MIDWEEK...AND CONTINUED GOOD RUN-TO-RUN AND MODEL-TO-MODEL
CONSISTENCY IN SHOWING THIS PATTERN...HAVE RAISED POPS TO THE LIKELY
RANGE FOR BOTH WEDNESDAY AND WEDNESDAY NIGHT. THEREAFTER...HAVE
INDICATED POPS SLOWLY LOWERING THROUGH THE CHANCE RANGE AS THE
FRONT PUSHES FURTHER SOUTH DURING THE THURSDAY-FRIDAY PERIOD...WITH
GENERALLY DRY WEATHER THEN INDICATED FOR NEXT SATURDAY WITH THE
AREA UNDER THE INFLUENCE OF WEAK RIDGING.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS THIS AFTERNOON AND EVENING WILL LOWER AT TIMES TO
MVFR/IFR IN SHOWERS AND THUNDERSTORMS AS THEY PASS THROUGH. THE
BEST THREAT WOULD BE FROM 19-23Z ACROSS THE WESTERN TERMINALS AND
LATER THIS EVENING ACROSS CENTRAL NEW YORK. ANY STORMS CAN HAVE
GUSTY WINDS. LOOK FOR GENERALLY MVFR CIGS OVERNIGHT INTO SUNDAY
MORNING AFTER THE FRONTAL PASSAGE...IMPROVING TO VFR BY MIDDAY.

OUTLOOK...
SUNDAY NIGHT...MAINLY VFR.
MONDAY AND TUESDAY...MAINLY VFR.
WEDNESDAY...MVFR IN SHOWERS/THUNDERSTORMS.

&&

.MARINE...
SOUTHEAST TO SOUTH WINDS ACROSS THE LOWER GREAT LAKES WILL VEER A
BIT TO SOUTH AND SOUTHWEST TONIGHT...BEFORE TENDING ALL
SOUTHWESTERLY ON SUNDAY AND FRESHENING A BIT BEHIND A DEPARTING COLD
FRONT. AT THIS POINT...CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL
CRAFT ADVISORY CRITERIA...THEREFORE NO ADVISORIES WILL BE ISSUED AT
THIS TIME.

THE ABOVE SAID...BOATERS SHOULD REMAIN ON ALERT FOR THUNDERSTORMS
LATE THIS AFTERNOON AND TONIGHT. SOME OF THESE STORMS WILL HAVE THE
POTENTIAL TO PRODUCE STRONG WIND GUSTS...ESPECIALLY LATE THIS
AFTERNOON AND THIS EVENING.

&&

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

&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BUFFALO NY
522 AM EDT SAT JUL 25 2009

NYZ001>008-010>014-019>021-085-260930-
NIAGARA-ORLEANS-MONROE-WAYNE-NORTHERN CAYUGA-OSWEGO-JEFFERSON-LEWIS-
NORTHERN ERIE-GENESEE-WYOMING-LIVINGSTON-ONTARIO-CHAUTAUQUA-
CATTARAUGUS-ALLEGANY-SOUTHERN ERIE-
522 AM EDT SAT JUL 25 2009

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

.DAY ONE...TODAY AND TONIGHT.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATER THIS
AFTERNOON AND EVENING AS A COLD FRONT APPROACHES THE LOWER GREAT
LAKES.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.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-SLZ022-024-260930-
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-
522 AM EDT SAT JUL 25 2009

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

.DAY ONE...TODAY AND TONIGHT.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATER THIS
AFTERNOON AND EVENING AS A COLD FRONT APPROACHES THE LOWER LAKES.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.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