000
FXUS61 KBUF 182341
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
741 PM EDT SAT MAY 18 2013

.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO DRIFT OFF THE NEW ENGLAND COAST 
THROUGH THE END OF THE WEEKEND AND WILL ALLOW WARMER AIR TO MOVE 
INTO THE REGION FOR SUNDAY. MAINLY DRY WEATHER WILL CONTINUE THROUGH 
MONDAY BEFORE A FRONTAL BOUNDARY STALLS OUT OVER THE REGION TUESDAY 
THROUGH THE END OF NEXT WEEK WITH PERIODS OF SHOWERS AND 
THUNDERSTORMS ALONG WITH WARM TEMPERATURES.

&&

.NEAR TERM /THROUGH SUNDAY/...
SURFACE HIGH PRESSURE WILL CONTINUE TO DRIFT OFF THE NEW ENGLAND 
COAST WITH INCREASING SOUTH TO SOUTHEAST RETURN FLOW OVERNIGHT. 
SURFACE WINDS WILL RESPOND AND BACK TO THE SOUTHEAST TONIGHT. WHILE 
THE WINDS WILL BE LIGHT...THEY WILL BE JUST ENOUGH TO COMBINE WITH 
INCREASING DEWPOINTS AND SOME CLOUD COVER TO HOLD TEMPERATURES UP 
COMPARED TO RECENT NIGHTS. EXPECT LOWS IN THE MID TO UPPER 50S ON 
THE LAKE PLAINS OF WESTERN NY...WITH LOWER 50S ACROSS THE INTERIOR 
SOUTHERN TIER AND EAST OF LAKE ONTARIO.

THE GFS REMAINS A WET OUTLIER WITH RESPECT TO SHOWER POTENTIAL 
TONIGHT...AS IT LIFTS A BAND OF SHOWERS THROUGH THE FINGER LAKES AND 
CENTRAL NY. IT APPEARS THE GFS IS MUCH TO AGGRESSIVE IN LOW LEVEL 
MOISTURE RETURN AND CONVERGENCE. THE NAM IS ALSO LIKELY TOO 
AGGRESSIVE IN POOLING MOISTURE ALONG LOW LEVEL BOUNDARIES AND 
GENERATES SOME SPOTTY QPF TONIGHT. WITH NO APPARENT FORCING 
MECHANISM AND RELATIVELY LIGHT LOW LEVEL FLOW...WILL OPT TO GO WITH 
THE MUCH DRIER CANADIAN GEM SOLUTION AND KEEP A DRY FORECAST 
OVERNIGHT. THERE WILL BE VARYING AMOUNTS OF CLOUD COVER WITH PERIODS 
OF MID CLOUD ACROSS WESTERN NY. ACROSS THE NORTH COUNTRY MAINLY 
CLEAR SKIES THIS EVENING WILL GIVE WAY TO INCREASING CLOUDS 
OVERNIGHT AS THE RETURN FLOW PUSHES CLOUDS OVER PENNSYLVANIA 
NORTHWARD. 

ON SUNDAY THE SOUTHERLY RETURN FLOW WILL CONTINUE TO BOOST 850MB 
TEMPS TO AROUND +12C. THIS SHOULD SUPPORT HIGHS IN THE UPPER 70S ON 
THE LAKE PLAINS OF WESTERN NY WITH AN ADDED BOOST FROM DOWNSLOPE 
FLOW. THE SOUTHERLY WINDS WILL BE STRONG ENOUGH TO PREVENT LAKE 
BREEZES IN MOST LOCATIONS...WITH THE ONE EXCEPTION LIKELY BEING THE 
LAKE ONTARIO SHORE FROM BRADDOCK BAY TO THE NIAGARA RIVER. HERE... 
ENE FLOW WILL KEEP HIGHS IN THE LOWER 60S ALONG THE IMMEDIATE 
LAKESHORE. 

EXPECT ANOTHER DAY OF VARYING CLOUD COVER ACROSS THE REGION AS MID 
LEVEL CLOUD AND INCREASING LOW LEVEL MOISTURE CROSS THE AREA. THE 
GFS CONTINUES TO BE AGGRESSIVE IN DEVELOPING SHOWERS ACROSS MUCH OF 
THE REGION...BUT AGAIN THIS LOOKS OVERDONE. THE LACK OF APPARENT 
FORCING OR STRONGER LOW LEVEL FLOW WILL LIKELY PREVENT ENOUGH LOW 
LEVEL CONVERGENCE OR MOISTURE POOLING TO SUPPORT ANY SHOWER CHANCES. 
THE ONE EXCEPTION MAY BE ACROSS THE EASTERN LAKE ONTARIO REGION 
WHERE LOW LEVEL WARM ADVECTION AND ISENTROPIC UPGLIDE IS MAXIMIZED. 
HERE WE WILL CARRY A LOW CHANCE OF A SPOTTY SHOWER OR TWO...BUT 
OTHERWISE WILL KEEP THE REST OF THE AREA DRY FOLLOWING THE DRIER NAM 
AND CANADIAN GEM SOLUTIONS.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
SUNDAY NIGHT WILL BE RATHER QUIET...AND MILD WITH RIDGING ALOFT OVER 
THE REGION. A LIGHT SOUTHERLY WIND WILL MAINTAIN LOWS IN THE LOWER 
60S ACROSS LOWER ELEVATIONS AND UPPER 50S ACROSS THE INLAND 
SOUTHWESTERN NYS AND THE NORTH COUNTRY. 

ON MONDAY BENEATH THE UPPER LEVEL RIDGE AXIS THE LOW LEVEL MOISTURE 
WILL INCREASE THROUGH THE DAY. THIS WILL INCREASE THE DEW POINTS AND 
WITH A FAIR AMOUNT OF SUNSHINE THROUGH THE DAY A BIT OF A HUMID 
AFTERNOON WILL BE IN STORE. HIGH TEMPERATURES ON MONDAY WILL CLIMB 
INTO THE UPPER 70S AND LOWER 80S WHICH WILL PRODUCE A FAIR AMOUNT OF 
INSTABILITY/CAPE. A WEAK COLD FRONT WILL CROSS THE REGION...HOWEVER 
WITH THE UPPER LEVEL RIDGE AXIS REMAINING OVER THE AREA THERE WILL 
JUST BE A LOW CHANCE POP FOR A FEW POP UP SHOWERS AND THUNDERSTORMS. 

MONDAY NIGHT THE UPPER LEVEL RIDGE WILL BEGIN TO WEAKEN AS WEAK 
IMPULSES OF ENERGY CREST THE RIDGE TOP. THE COLD FRONT BOUNDARY WILL 
STALL JUST TO OUR SOUTH WITH A CONTINUE LOW CHANCE POP FOR A SHOWER 
OR THUNDERSTORM OVERNIGHT. THE GREATEST CHANCE FOR A SHOWER OR 
THUNDERSTORM WILL BE ACROSS SW NEW YORK IN PROXIMITY TO A 
WARM FRONT THAT WILL BE FOUND ACROSS THE CENTRAL GREAT LAKE STATES. 
ELEVATED INSTABILITY OF OVER 500 J/KG WILL BRING A THREAT OF SHOWERS 
AND THUNDERSTORMS THROUGH THE NIGHT HERE. WITH LITTLE CHANGE TO THE 
AIRMASS OVERNIGHT LOWS WILL BE SIMILAR TO SUNDAY NIGHT...WITH LOWS 
IN THE LOWER 60S ACROSS WESTERN NEW YORK AND UPPER 50S ACROSS THE 
NORTH COUNTRY.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
IN THIS TIME PERIOD SHOWERS AND THUNDERSTORMS WILL BE LIKELY 
EARLY...WITH POSSIBLE COOLER AND DRIER AIR SETTLING OVER THE REGION 
FOR THE START OF NEXT WEEKEND...THOUGH MODEL DIFFERENCES BRING A BIT 
OF UNCERTAINTY FOR WHEN THIS WILL HAPPEN. 

ON BOTH TUESDAY AND WEDNESDAY A CLOSED UPPER LEVEL LOW WILL BE 
CENTERED OVER THE CENTRAL PLAINS WITH A ZONAL FLOW ALOFT OVER THE 
EASTERN GREAT LAKES. DAYTIME INSTABILITY OF 1000+ J/KG ON TUESDAY 
WILL LIKELY BRING SHOWERS AND THUNDERSTORMS. WEDNESDAY A SLIGHT 
SOUTHWARD PUSH TO A WEAK FRONTAL BOUNDARY WILL LIKELY FOCUS THE 
CONVECTION TOWARDS THE STATE LINE...WITH JUST A LOW CHANCE ACROSS 
THE NORTH COUNTRY. 

ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS WILL COME THURSDAY AND 
THURSDAY NIGHT WHEN THE SHORTWAVE FROM THE CENTRAL PLAINS PASSES 
TOWARDS OUR REGION. UPPER LEVEL HEIGHT FALLS AND LOW LEVEL 
CONVERGENCE AHEAD OF A COOL POOL OF AIR WILL BRING SHOWERS AND 
PERHAPS SOME THUNDERSTORMS. INSTABILITY WILL NOT BE AS GREAT 
THURSDAY...COMPARED TO TUESDAY AND WEDNESDAY.

THE ECMWF WILL PHASE THIS CENTRAL PLAINS LOW WITH A SHORTWAVE 
DROPPING SOUTHWARD FROM EASTERN CANADA. THIS PHASING WILL DEVELOP A 
TROUGH THAT WILL DRIVE A COLD FRONT ACROSS THE REGION THURSDAY 
NIGHT. BEHIND THE COLD FRONT HIGH PRESSURE AND MUCH DRIER AND COOLER 
AIR WILL FILTER ACROSS THE EASTERN GREAT LAKES. MEANWHILE THE GFS 
DOES NOT PHASE THESE TWO TROUGHS OF LOW PRESSURE...AND CONTINUES A 
CHANCE OF SHOWERS ON FRIDAY...KEEPING THE CORE OF THE COOLER AND 
DRIER AIR ACROSS THE WESTERN GREAT LAKES. WILL CONTINUE WITH 
CONTINUITY AND CONTINUE A LOW CHANCE POP FOR FRIDAY...WITH COOLER 
AND DRIER AIR BUILDING ACROSS THE REGION FOR THE WEEKEND.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR WILL PREVAIL TONIGHT AND SUNDAY. MID AND HIGH CLOUDS WILL 
CONTINUE TO STREAM OVER WESTERN AND CENTRAL NY TONIGHT. EVENTUALLY 
SOME DEEPER LOW LEVEL MOISTURE WILL PUSH NORTH THROUGH CENTRAL NY 
LATE TONIGHT AND THEN REACH THE EASTERN LAKE ONTARIO REGION ON 
SUNDAY. STILL EXPECT CIGS TO BE VFR WITHIN THIS AREA AS WELL. THE 
COMBINATION OF INCREASING MOISTURE AND WARM ADVECTION MAY TOUCH OFF 
A FEW SCATTERED SHOWERS EAST OF LAKE ONTARIO ON SUNDAY...BUT THESE 
SHOULD REMAIN LIGHT ENOUGH TO KEEP CIGS/VSBY MAINLY VFR. FARTHER 
WEST EXPECT A CONTINUATION OF DRY WEATHER ON SUNDAY WITH PERIODS OF 
MID/HIGH CLOUDS.

OUTLOOK...  
MONDAY...VFR.
TUESDAY AND THURSDAY...MAINLY VFR WITH A CHANCE OF SHOWERS AND 
THUNDERSTORMS AND ASSOCIATED BRIEF MVFR/IFR.

&&

.MARINE...
FINE RECREATIONAL BOATING CONDITIONS WILL REMAIN IN PLACE ON LAKES 
ERIE AND ONTARIO THROUGH THE END OF THE WEEKEND. WINDS WILL 
GENERALLY BE EAST AT 5 TO 15 KNOTS THROUGH SUNDAY WITH LIGHT WAVE 
ACTION. TYPICAL OF SPRING...GENERALLY LIGHT WINDS WILL CONTINUE 
THROUGH MUCH OF NEXT WEEK. THE CHANCES OF THUNDERSTORMS WILL 
INCREASE TUESDAY THROUGH MUCH OF THE WEEK HOWEVER...WITH LOCALLY 
STRONGER WINDS AND WAVES NEAR THUNDERSTORMS.

&&

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

&&

$$

SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK/SMITH
SHORT TERM...THOMAS
LONG TERM...THOMAS
AVIATION...HITCHCOCK/SMITH
MARINE...HITCHCOCK