Area Forecast Discussion Issued by NWS Buffalo, NY
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000
FXUS61 KBUF 250241
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
1041 PM EDT FRI MAY 24 2013
.SYNOPSIS...
CANADIAN HIGH PRESSURE BUILDING ACROSS THE GREAT LAKES WILL BRING
MAINLY DRY AND COOL CONDITIONS THIS WEEKEND. TEMPERATURES WILL
REBOUND BACK TO ABOVE AVERAGE NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
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AS OF 1030 PM...REGIONAL RADARS SHOW THE BACK EDGE OF THE COASTAL
LOW/S PRECIPITATION SHIELD LINGERING NEAR THE LEWIS COUNTY
BORDER...WITH PATCHY LIGHT RAIN/SCATTERED LIGHT SHOWERS EXTENDING
BACK TO THE INTERSTATE 81 CORRIDOR IN CENTRAL NEW YORK. WITH THE
POSITION OF THE COASTAL LOW CHANGING LITTLE OVERNIGHT...WILL KEEP A
CHANCE OF RAIN SHOWERS IN PLACE ACROSS LEWIS COUNTY...ALONG WITH
CONTINUED MOSTLY CLOUDY SKIES ACROSS THE NORTH COUNTRY.
FURTHER TO THE WEST...CLEARING SKIES HAVE PROGRESSED ACROSS MUCH OF
WESTERN NEW YORK WEST OF THE GENESEE VALLEY...WHILE MOSTLY CLOUDY
SKIES PERSIST FROM THE GENESEE VALLEY EASTWARD. FOR THE REMAINDER OF
THE NIGHT...EXPECT THIS CLEARING TREND TO SLOWLY PUSH EASTWARD
ACROSS THE GENESEE VALLEY AND FINGER LAKES AS HIGH PRESSURE/DRIER
AIR SLOWLY BUILDS EAST FROM THE CENTRAL GREAT LAKES...THOUGH RECENT
SATELLITE TRENDS SUGGEST THIS WILL LIKELY TAKE PLACE A BIT MORE
SLOWLY THAN PREVIOUSLY THOUGHT.
WITH THE CLEARING SKIES AND CHILLY AIRMASS THAT IS IN PLACE...
TEMPERATURES WILL BE A CONCERN OVERNIGHT...PARTICULARLY ACROSS
INTERIOR SECTIONS OF THE SOUTHERN TIER THAT ONLY HAVE A SHORT WAYS
TO GO BEFORE REACHING THE FREEZING MARK...AND WHERE THE CURRENT
FREEZE WARNING STILL LOOKS PLAUSIBLE. MEANWHILE FURTHER TO THE
NORTH...SOME SPOTS CLOUD SEE TEMPS AS LOW AS THE MID 30S...HOWEVER
FEEL THERE WILL BE ENOUGH OF A GRADIENT AND/OR LINGERING CLOUD COVER
TO PREVENT MUCH IN THE WAY OF A FROST THREAT.
SATURDAY...MODELS IN CLOSER AGREEMENT WITH THE SLOW PROGRESSION OF
THE UPPER LOW. ASSOCIATED PRECIPITATION LOOKS TO BACK IN FROM THE
EAST AND MAY IMPACT AREAS EAST OF LAKE ONTARIO. BULK OF THE AREA
WILL SEE PLENTY OF SUNSHINE. WITH COLD AIR MASS CENTERED OVER THE
AREA WE WILL ONLY SEE HIGHS IN THE MID 50S TO LOWER 60S...ALTHOUGH
COOL WILL BE AN IMPROVEMENT OVER TODAYS READINGS IN THE 30S AND
40S.-- End Changed Discussion --
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
SATURDAY NIGHT A CLOSED UPPER LEVEL LOW WILL BE SITTING OVER NEW
ENGLAND...WITH A COLD NORTHWEST FLOW ACROSS THE EASTERN GREAT LAKES.
MOISTURE AND PRECIPITATION AROUND THIS AREA OF LOW PRESSURE WILL
LARGELY BE CONFINED TO AREAS JUST TO OUR EAST...THOUGH A FEW LIGHT
SHOWERS MAY BRUSH BY OUR NORTH COUNTRY. BY SUNDAY MORNING COLD AIR
UNDER THIS AREA OF LOW PRESSURE WILL BACK SLIGHTLY WESTWARD SUCH
THAT -2C AIR AT 850 HPA WILL BE FOUND ACROSS THE WESTERN FOOT HILLS
OF THE ADIRONDACKS AND WOULD NOT BE SURPRISED IF A FEW SNOW FLURRIES
MIXED IN WITH THE LIGHT RAIN SHOWERS.
AWAY FROM THE NORTH COUNTRY MAINLY CLEAR SKIES WILL BE FOUND AND
COLD WITH A NORTHWEST WIND. THE GRADIENT BETWEEN HIGH PRESSURE
NOSING SOUTHWARD OVER THE CENTRAL GREAT LAKES AND THE CLOSED LOW
OVER NEW ENGLAND WILL BE ABOUT THE SAME SATURDAY NIGHT AS FRIDAY
NIGHT. CURRENT THINKING IS THAT FREEZING TEMPERATURES WILL BE A
CONCERN AGAIN ACROSS THE SOUTHERN TIER...AND THAT THE LIGHT WINDS
WILL LIMIT THE FROST FORMATION. CLOSER TO THE LAKES IS WHERE THE
WARMEST OVERNIGHT LOWS WILL BE FOUND WITH UPPER 30S TO AROUND 40 FOR
NIGHTTIME LOWS.
THERE WILL BE A LITTLE IMPROVEMENT SUNDAY AS THE CLOSED LOW SLOWLY
LIFTS THROUGH NORTHERN NEW ENGLAND. THIS MOVEMENT SHOULD BE ENOUGH
TO KEEP OUR AREA DRY WITH LINGERING CLOUDS BRUSHING BY THE EASTERN
PORTIONS OF THE NORTH COUNTRY. ELSEWHERE PLENTY OF SUNSHINE WILL
AGAIN BE FOUND ACROSS AREAS SOUTH OF LAKE ONTARIO AND WITH 850 HPA
RANGING FROM +2 TO +4 OUR HIGHS WILL BE A COUPLE DEGREES WARMER THAN
SATURDAY...WITH HIGHS IN THE LOW 60S. A LIGHT NORTHWEST WIND WILL
AGAIN BE FOUND ACROSS THE CWA.
SUNDAY NIGHT WILL BE DRY AND WINDS BACKING TO MORE OF A SOUTHWESTERLY
FLOW. WHILE FREEZING TEMPERATURES WILL BE VERY SPOTTY ACROSS THE
SOUTHERN TIER AND INLAND NORTH COUNTRY THE LIGHTER WINDS AND RELAXED
PRESSURE GRADIENT WILL ALLOW FOR SOME PATCHY FROST.
ON MONDAY SURFACE HIGH PRESSURE WILL SLIDE INTO THE REGION.
SUBSIDENCE WITH THIS FEATURE WILL BRING A DRY MEMORIAL DAY AND
ABUNDANT SUNSHINE ACROSS THE REGION. THOUGH A BLUE SKY TEMPERATURES
WILL STILL FALL SHY OF NORMAL WITH AFTERNOON HIGHS IN THE MID TO
UPPER 60S. DEWPOINTS WILL ALSO BE LOW...IN THE MID TO UPPER 30S
WHICH WILL BRING LOW RH VALUES. DRY CONDITIONS WILL CONTINUE THROUGH
THE NIGHT MONDAY WITH LOWS DROPPING BACK INTO THE 40S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THIS TIME PERIOD WILL BE MAINLY DRY...WITH BUILDING HEAT AND
HUMIDITY. THERE IS STILL A BIT OF UNCERTAINTY AS TO WHEN A WARM
FRONT LIFTING NORTHEASTWARD WILL CROSS THE EASTERN GREAT LAKES
REGION. THE 12Z GFS/12Z CANADIAN OPERATIONAL MODEL RUNS ARE A LITTLE
FASTER THAN THE 12Z ECMWF...WITH A PASSAGE TUESDAY...WHILE THE
EUROPEAN MODEL FOCUSES MORE UPON WEDNESDAY. WILL BRING LOW CHANCE
POPS FOR SHOWERS AND THUNDERSTORMS ACROSS THE REGION TUESDAY
NIGHT-WEDNESDAY NIGHT.
BEFORE THE FRONTAL PASSAGE IT WILL BE COMFORTABLE WITH LOW DEWPOINTS
AND SEASONABLE LATE MAY TEMPERATURES.
AFTER THE WARM FRONT PASSES HUMIDITY WILL BEGIN TO BUILD WHILE
TEMPERATURES EACH DAY WILL LIKELY BE A DEGREE OR SO WARMER. BY
FRIDAY AFTERNOON HIGHS WILL BE WELL INTO THE 80S ACROSS THE REGION.
THE BUILDING RIDGE OVER THE REGION THURSDAY AND FRIDAY WILL LIKELY
CAP ANY AFTERNOON SHOWERS AND THUNDERSTORM DEVELOPMENT...AND THUS WE
WILL MAINTAIN A DRY FORECAST FOR NOW.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
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LINGERING 5-6 KFT CIGS AND A CHANCE OF SHOWERS WILL PERSIST ACROSS THE
EASTERN LAKE ONTARIO REGION THROUGH SATURDAY AS LOW PRESSURE SLOWLY
LIFTS NORTH ALONG THE NEW ENGLAND COAST. MEANWHILE FURTHER TO THE
WEST...LINGERING VFR CIGS WILL CONTINUE TO LIFT AND EVENTUALLY
SCATTER OUT FROM WEST TO EAST AS HIGH PRESSURE AND DRIER AIR BUILDS
EAST FROM THE CENTRAL GREAT LAKES...WITH UNLIMITED VFR CONDITIONS
THEN FOLLOWING FOR THE BALANCE OF THE TAF PERIOD.
OUTLOOK...
SATURDAY NIGHT THROUGH WEDNESDAY...VFR.-- End Changed Discussion --
&&
.MARINE...
UNSEASONABLE CONDITIONS ARE IN PLACE OVER THE LOWER LAKES REGION DUE
TO THE PRESENCE OF A DEEP UPPER TROUGH AND PLENTY OF ASSOCIATED COLD
AIR ALOFT...WITH A PERSISTENT NORTHWESTERLY LOW LEVEL FLOW
SUSTAINING LOW END ADVISORY LEVEL CONDITIONS. THESE WILL PERSIST
INTO THE OVERNIGHT HOURS ON LAKE ERIE AND THE WESTERN END OF LAKE
ONTARIO...BEFORE WINDS BEGIN TO DIMINISH. THIS SAID...SMALL CRAFT
CONDITIONS MAY REDEVELOP ON LAKE ERIE SATURDAY AFTERNOON.
FURTHER EAST...THE MODEST NORTHWESTERLY FLOW WILL PERSIST INTO
SATURDAY ON THE EASTERN END OF LAKE ONTARIO...WHICH WILL MAINTAIN
LOW END SMALL ADVISORY-LEVEL CONDITIONS THERE.
CONDITIONS WILL IMPROVE SUNDAY AND MONDAY AS HIGH PRESSURE MOVES
OVERHEAD...WITH NO ISSUES FORESEEN FOR THE LATTER PORTIONS OF THE
HOLIDAY WEEKEND.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...FREEZE WARNING FROM 2 AM TO 7 AM EDT SATURDAY FOR NYZ019>021.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR
LOZ043>045.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR LOZ042.
&&
$$
SYNOPSIS...TMA
NEAR TERM...JJR/TMA
SHORT TERM...THOMAS
LONG TERM...THOMAS
AVIATION...JJR
MARINE...JJR/TMA