Skip Navigation Linkswww.nws.noaa.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service Forecast Office   NWS logo - Click to go to the NWS homepage
Buffalo, NY banner image
 
 

Area Forecast Discussion
Latest Versions  [Current][-1][-2][-3][-4][-5][-6][-7][-8][-9]



000
FXUS61 KBUF 301857
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
257 PM EDT TUE SEP 30 2014

.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL BRING CLOUDS AND SCATTERED SHOWERS 
TO SOUTHERN AND WESTERN NEW YORK TONIGHT AND EARLY WEDNESDAY. 
LINGERING CLOUDS WILL BREAK WITH A RETURN TO MILD AND WARM WEATHER 
ON THURSDAY. A STRONG COLD FRONT IS THEN EXPECTED TO CROSS THE 
REGION ON FRIDAY...BRINGING A GREATER LIKELIHOOD OF SHOWERS FOLLOWED 
BY MUCH COOLER TEMPERATURES FOR THE UPCOMING WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
SURFACE LOW MOVING SOUTHEAST INTO WESTERN PA WILL OPEN UP INTO 
SURFACE TROUGH...WITH SCATTERED LIGHT RAIN SHOWERS ACROSS THE 
SOUTHERN TIER AND SOME SPRINKLES ACROSS THE REST OF WESTERN NEW 
YORK. THE NORTH COUNTRY SHOULD AVOID ANY POSSIBILITY OF PRECIP 
TONIGHT AND WEDNESDAY.

AN INVERTED TROUGH WILL BECOME ESTABLISHED ACROSS WESTERN HALF OF 
THE STATE WITH SCATTERED SPRINKLES POSSIBLE THROUGH THE NIGHT AND 
EARLY WEDNESDAY. THIS TROUGH WILL ALSO DRAW MOIST AIR FROM LAKE 
ONTARIO AND EXPECTED TO PRODUCE PATCHY FOG OVERNIGHT...ESPECIALLY 
FROM THE LAKESHORE TO THE ESCARPMENTS SOUTH OF THE LAKE. 

HIGH PRESSURE NORTH OF LAKE ONTARIO WILL MOVE TOWARD THE SAINT 
LAWRENCE VALLEY ON WEDNESDAY AND WILL RIDGE SOUTHWARD WITH DRIER AIR 
AND BRING ABOUT A CLEARING TREND LATE IN THE DAY ON WEDNESDAY.

TEMPERATURES WILL RANGE MOSTLY IN THE MID 50S OVERNIGHT WITH A 
MODERATING INFLUENCE FROM LAKE ONTARIO AND THE THICKER CLOUD COVER. 
HIGHS ON WEDNESDAY WILL BE A LITTLE SHY OF TODAYS TEMPS WITH MAINLY 
UPPER 60S TO LOW 70S...THE WARMER SPOTS ACROSS THE NORTH COUNTRY 
WHERE CLOUDS WILL BE THINNER AND MORE SUNSHINE.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
OUR PROLONGED STRETCH OF INDIAN SUMMER WEATHER WILL COME TO AN END 
DURING THIS PERIOD AS A STRONG PACIFIC JET RACING ACROSS BRITISH 
COLUMBIA WILL PUSH A DEEPENING LONGWAVE TROUGH ACROSS THE CENTER OF 
THE COUNTRY...WHICH IN TURN WILL DISLODGE RIDGING OVER THE LOWER 
GREAT LAKES. THIS PROCESS WILL EVENTUALLY LEAD TO THE DEVELOPMENT OF 
AN ANOMALOUSLY DEEP CLOSED LOW OVER THE GREAT LAKES REGION. BY THE 
TIME THE ASSOCIATED PATTERN CHANGING SFC COLD FRONT MAKES ITS WAY 
ACROSS OUR FORECAST AREA...TEMPERATURES WILL HAVE AVERAGED ABOVE 
NORMAL FOR NEARLY TWO WEEKS.

THE SEMBLANCE OF A REX BLOCK (RIDGING OVER QUEBEC/CUTOFF LOW OVER 
NEW ENGLAND) FOUND OVER THE ST LAWRENCE VALLEY WEDNESDAY NIGHT WILL 
PUSH EAST TO THE CANADIAN MARITIMES DURING THE DAY THURSDAY. THIS 
GENERAL SCENARIO WILL PROMOTE FAIR DRY WEATHER FOR OUR REGION 
WEDNESDAY NIGHT...THEN A SECOND REINFORCING RIDGE WILL BUILD ACROSS 
THE LOWER GREAT LAKES IN ITS IMMEDIATE WAKE TO SUPPLY US WITH A 
BEAUTIFUL DAY ON THURSDAY. SUBSIDENCE ASSOCIATED WITH THE RIDGE WILL 
COMBINE WITH A DEEPENING SOUTHERLY FLOW TO SUPPORT WIDESPREAD 
AFTERNOON TEMPERATURES IN THE MID 70S. SITES ACROSS THE GENESEE 
VALLEY AND IN THE DOWNSLOPE AREAS NEAR THE IAG ESCARPMENT SHOULD 
MAKE IT INTO THE UPPER 70S.

A 130KT H25 JET OVER THE NORTHERN ROCKIES THURSDAY EVENING WILL DIG 
INTO A DEEPENING LONGWAVE TROUGH OVER THE NORTHERN PLAINS DURING THE 
OVERNIGHT...WHICH WILL SUPPORT THE CONSOLIDATION OF A SFC LOW OVER 
THE UPPER GREAT LAKES. THIS WILL INTENSIFY A DOWNSTREAM LOW LEVEL 
JET OVER MICHIGAN...WHICH IN COMBINATION WITH RIDGING TO OUR EAST 
WILL KEEP A VERY WARM SOUTHERLY FLOW IN PLACE OVER OUR REGION. THE 
RESULT WILL BE A WARM DRY NIGHT WITH MIN TEMPERATURES GENERALLY 
WITHIN A FEW DEGREES OF 60. THESE READINGS WILL BE SOME 15 DEG F 
ABOVE NORMAL EARLY OCT VALUES...OR CLOSE TO WHERE WE SHOULD BE FOR 
DAYTIME HIGHS. 

ON FRIDAY...A FEED OF 80-100 WINDS AT H25 WILL CONTINUE TO POUR INTO 
THE LONGWAVE TROUGH OVER THE MISSISSIPPI VALLEY. THIS WILL ENCOURAGE 
THE DEVELOPMENT OF A CUT OFF LOW NEAR THE ARROWHEAD OF MINNESOTA 
WHILE THE ASSOCIATED SFC LOW WILL LIFT DUE NORTH. THE MOVEMENT OF 
THE DEEPENING SFC LOW SHOULD BE A CLUE AS TO THE DOWNSTREAM FLOW 
OVER OUR REGION. AN ANOMALOUSLY STRONG 50KT SOUTHERLY LOW LEVEL JET 
OVER THE LOWER GREAT LAKES WILL NOT ONLY SUPPORT ONE MORE WARM DAY 
OVER OUR FORECAST AREA...BUT WILL ALSO KEEP THE EASTWARD PROGRESSION 
OF THE SFC FRONT AND ITS ASSOCIATED PCPN TO A CRAWL. HAVE THUS 
CONTINUED THE TREND OF SLOWING THE ADVANCEMENT OF THE SHOWERS...IN 
THIS CASE BY SOME 3-6 HOURS. THE BULK OF THE DAY SHOULD THUS BE RAIN 
FREE FOR SITES EAST OF THE GENESEE VALLEY...WITH LIKELY POPS NOT 
EXPECTED FOR THE FAR WESTERN COUNTIES UNTIL LATE. AGAIN...MANY AREAS 
WILL EXPERIENCE MAX TEMPS IN THE MID TO UPPER 70S.

THE COLD FRONT...WHICH WILL BE ON OUR DOORSTEP STRETCHING FROM LAKE 
HURON TO CENTRAL LAKE ERIE FRIDAY EVENING...WILL GRUDGINGLY PUSH 
ACROSS OUR FORECAST AREA DURING THE COURSE OF FRIDAY NIGHT. THE LOW 
LEVEL FORCING FROM THE COLD FRONT WILL BE ACCOMPANIED BY A 
RELATIVELY NARROW 3 HR WINDOW OF ENHANCED LIFT SUPPLIED BY THE RR 
ENTRANCE REGION OF A CYCLONICALLY CURVED 120KT H25 JET OVER SOUTHERN 
ONTARIO. WILL HOLD ONTO THE HIGH LIKELY POPS WITH THIS PACKAGE...BUT 
AS THE CONFIDENCE IN THE TIMING OF THIS FRONTAL PASSAGE BECOMES 
GREATER...CAN EASILY SEE POPS BEING RAISED TO CATEGORICAL. GIVEN 
LAPSE RATES OF LESS THAN 6 DEG C/KM...WILL CONTINUE TO LEAVE OUT THE 
MENTION OF ANY THUNDER. THAT BEING SAID...THERE SHOULD BE DEEP 
ENOUGH LIFT AND SUFFICIENT MOISTURE TO SUPPORT SOME HEAVIER SHOWERS.

H85 TEMPS THAT WILL BE IN THE VCNTY OF 12-14C AHEAD OF THE FRONT 
FRIDAY EVENING WILL PLUNGE TO ARND 2C (WRN COUNTIES) BY DAYBREAK. 
THIS SHOULD ENABLE TEMPS OVER THE FAR WESTERN COUNTIES TO BOTTOM OUT 
AT NORMAL LEVELS (40S).

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
TEMPERATURES WILL AVERAGE NEAR TO BELOW NORMAL DURING THIS PERIOD AS 
A PERSISTENT LONGWAVE TROUGH WILL BE CENTERED OVER ONTARIO AND THE 
GREAT LAKES REGION. THE CORE OF THE COLDEST AIR ASSOCIATED WITH THIS 
TROUGH WILL BE OVER THE GREAT LAKES REGION DURING THE SECOND HALF OF 
THE WEEKEND. AS THE NEGATIVELY TILTED LONGWAVE ROTATES POLEWARD 
ACROSS EASTERN CANADA EARLY NEXT WORK WEEK...A NEAR ZONAL PACIFIC 
FLOW WILL PROMOTE A MODIFICATION OF THE AIRMASS OVER GREAT LAKES. 

FOR SATURDAY...THE SFC COLD FRONT WILL PUSH AWAY FROM OUR REGION VIA 
THE ST LAWRENCE VALLEY WHILE A SHORTWAVE RIDGE WILL BUILD ACROSS THE 
LOWER GREAT LAKES AND OUR FORECAST AREA IN ITS WAKE. THIS RIDGING 
WILL WORK AGAINST ORGANIZED LAKE DRIVEN SHOWER ACTIVITY...EVEN 
THOUGH H85 TEMPS NEAR 2C WILL SUPPLY PLENTY OF INSTABILITY OVER THE 
LAKES. WILL CARRY LIKELY POPS FOR THE MORNING ACROSS THE NORTH 
COUNTRY WITH GENERALLY LOW CHC POPS ELSEWHERE. THE BULK OF THE 
MIDDAY AND AFTERNOON SHOULD BASICALLY BE PCPN FREE...BUT CHILLY AS 
TEMPERATURES WILL CLIMB INTO THE UPPER 50S TO LOWER 60S.

THE CYCLONIC FLOW FOUND ABV 10K FT WILL WORK TO THE SFC SATURDAY 
NIGHT AS THE AFOREMENTIONED RIDGING WILL PUSH EAST. THIS WILL 
ENCOURAGE THE DEVELOPMENT OF SOME LAKE DRIVEN RAIN SHOWERS EAST OF 
LK ERIE AND PARTICULARLY EAST OF LK ONTARIO IN THE VCNTY OF THE TUG. 
LOW TEMPS WILL RANGE FROM THE 30S ACROSS THE SRN TIER TO THE LOWER 
40S MOST ELSEWHERE.

AS THE CORE OF THE NEGATIVELY TILTED UPPER LEVEL TROUGH ADVANCES TO 
THE NORTH ON SUNDAY...THE LOW LEVEL FLOW WILL BACK AND THIS WILL 
SEND INCREASINGLY DISORGANIZED LAKE EFFECT RAIN SHOWERS TO PARTS OF 
THE IAG FRONTIER AND ACROSS THE HEART OF JEFFERSON COUNTY. H85 TEMPS 
STRADDLING THE ZERO DEG ISOTHERM WILL SUGGEST DAYTIME HIGHS WILL 
ONLY BE IN THE 50S.

A BROAD AREA OF LOW PRESSURE IS FORECAST TO DRIFT ACROSS THE GREAT 
LAKES AND SOUTHERN ONTARIO ON MONDAY. THIS WILL BRING THE CHANCE FOR 
SOME SHOWERS TO ALL OF OUR REGION...ALTHOUGH THE BULK OF THE DAY 
SHOULD BE PCPN FREE.

FINALLY FOR TUESDAY...LOW LEVEL RIDGING OVER THE MISSISSIPPI VALLEY 
WILL DRIFT EAST ACROSS THE UPPER GREAT LAKES AND OHIO VALLEY WHILE 
THE AFOREMENTIONED SFC LOW WILL WORK ITS WAY DOWN THE ST LAWRENCE 
VALLEY. THE EXITING SFC LOW WILL ONCE AGAIN POSE THE OPPORTUNITY FOR 
SOME BADLY NEEDED RAIN SHOWERS.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
A FEW SHOWERS WILL PASS ACROSS THE REGION LATE TODAY. WILL MAINTAIN 
VCSH AS THIS ACTIVITY IS EXPECTED TO BE SCATTERED SOUTH OF LAKE 
ONTARIO. THE EXCEPTION WILL BE ACROSS THE SOUTHERN TIER WHICH WILL 
LIE CLOSER TO THE UPPER LEVEL SHORTWAVE AND COLD POOL ALOFT. THE 
NORTH COUNTRY SHOULD REMAIN VFR THROUGH THIS TAF PERIOD.

TONIGHT CLOUDS WILL LOWER SOUTH OF LAKE ONTARIO AS WINDS VEER AROUND 
TO NORTHEASTERLY. A STILL CONVERGENCE BOUNDARY IN THE LOW LEVELS MAY 
SERVE AS A FOCUS FOR SPRINKLES AND LOW MVFR OR IFR CLOUDS SOUTH OF 
LAKE ONTARIO AS THE NORTHEAST WINDS MAINTAIN AMPLE LOW LEVEL 
MOISTURE. 

CLOUDS WILL THIN AND DISSIPATE LATER ON WEDNESDAY WITH VFR OVERALL.

OUTLOOK... 
WEDNESDAY THROUGH THURSDAY...VFR...EXCEPT FOR LOCALIZED IFR IN 
SOUTHERN TIER VALLEY FOG BETWEEN 06Z-15Z EACH DAY.
FRIDAY...VFR LOWERING TO MVFR WITH SHOWERS BECOMING LIKELY.
SATURDAY...MVFR WITH A CHANCE OF SHOWERS.

&&

.MARINE...
AN UPPER LEVEL LOW...AND WEAK SURFACE LOW WILL DIVE SOUTHEASTWARD 
ACROSS PENNSYLVANIA TODAY TONIGHT. A LIGHT WIND WILL BECOME 
NORTHEASTERLY TONIGHT AND INCREASE TO AROUND 15 KNOTS ON LAKE 
ONTARIO...AND 10 KNOTS ON LAKE ERIE. THESE STRONGER WINDS ON LAKE 
ONTARIO WILL BRING WAVES 2 TO 4 FEET TONIGHT. WEAKER WINDS WILL 
ALLOW FOR 1 TO PERHAPS 2 FOOT WAVES ON THE EASTERN END OF LAKE ERIE 
TONIGHT. 

WAVES AND WINDS WILL DIMINISH THROUGH THE DAY WEDNESDAY AS HIGH 
PRESSURE AGAIN BUILDS ACROSS THE LOWER LAKES REGION. 

LATE IN THE WEEK...A STRONG AREA OF LOW PRESSURE IS EXPECTED TO LIFT 
ACROSS THE GREAT LAKES REGION ON FRIDAY...WHILE SWINGING A STRONG 
TRAILING COLD FRONT ACROSS THE LOWER LAKES. THE TIGHTENING PRESSURE 
GRADIENT ASSOCIATED WITH THE LOW WILL LEAD TO A PERIOD OF STRONGER 
WINDS...WITH ADVISORY-LEVEL WINDS AND WAVES BECOMING POSSIBLE.

&&

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

&&

$$

SYNOPSIS...WCH
NEAR TERM...WCH
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...WCH
MARINE...THOMAS/WCH







National Weather Service
Disclaimer Privacy Policy