Area Forecast Discussion
Issued by NWS Buffalo, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KBUF 181809
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
209 PM EDT THU SEP 18 2014

.SYNOPSIS...
A RELATIVELY WEAK COLD FRONT WILL SETTLE SOUTH OF OUR FORECAST AREA
THIS AFTERNOON...AND THIS WILL BE FOLLOWED BY STRONG CANADIAN HIGH
PRESSURE THAT WILL PASS BY TO OUR NORTH. THIS SCENARIO WILL SUPPORT
A COOL BUT OTHERWISE PLEASANT DAY ON FRIDAY...THEN AS THE HIGH MOVES
OFF THE COAST...ITS CLOCKWISE CIRCULATION WILL PUMP NOTICEABLY
WARMER AIR ACROSS OUR REGION FOR SATURDAY. A FRONTAL SYSTEM WILL
LIKELY GENERATE SOME SHOWERS FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE JUST NORTH OF THE UPPER LAKES WILL BUILD SOUTHEAST
TOWARD THE REGION THIS AFTERNOON. RADAR IMAGERY SHOWING JUST A FEW
SPRINKLES ACROSS THE WESTERN SOUTHERN TIER/FINGER LAKES THIS
AFTERNOON. ASIDE FROM THAT...THE MAIN IMPACT CONTINUES TO BE THE
SHIELD OF LAKE CLOUDS BLANKETING AREAS FROM THE NIAGARA FRONTIER
EAST THROUGH THE FINGER LAKES.

TONIGHT...SFC HIGH PRESSURE WILL PASS BY TO OUR NORTH. THIS WILL
EFFECTIVELY REMOVE OUR UPSLOPE FLOW AS WINDS WILL VEER TO THE EAST-
SOUTHEAST WHILE DRYING WILL TAKE PLACE AT ALL LEVELS. THE CLEARING
SKIES AND LIGHT SFC WINDS WILL THEN PROMOTE FAVORABLE RADIATIONAL
COOLING OF A FRESH CANADIAN AIRMASS. TEMPERATURES AWAY FROM THE
LAKES WILL DROP INTO THE 30S...WITH SOME UPPER 20S ACROSS THE TUG
HILL AND WESTERN ADIRONDACKS. FREEZE WARNING REMAINS IN EFFECT FOR
JEFFERSON/LEWIS COUNTIES...WITH A FROST ADVISORY IN EFFECT FOR
OSWEGO COUNTY. SOME FROST IS ALSO EXPECTED ACROSS THE SOUTHERN TIER
AND POSSIBLY IN THE FINGER LAKES REGION. WAITING ON THE LATEST
GUIDANCE PACKAGE TO FINISH COMING IN TO HAVE ANOTHER LOOK AT THE
POSSIBILITY OF A FROST ADVISORY FOR THESE AREAS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
THIS PERIOD WILL OPEN WITH HIGH PRESSURE DRIFTING FROM THE UPPER
SAINT LAWRENCE VALLEY TO THE NEW ENGLAND COAST ON FRIDAY. PLENTY OF
DRY AIR AND SUBSIDENCE ASSOCIATED WITH THE DEPARTING HIGH WILL LEAD
TO DRY WEATHER AND PLENTIFUL SUNSHINE. AFTER A CHILLY START...THE
COMBINATION OF THE AFOREMENTIONED SUNSHINE AND WARM ADVECTION AROUND
THE BACKSIDE OF THE DEPARTING HIGH WILL HELP TEMPERATURES TO RECOVER
QUITE NICELY...WITH READINGS PEAKING IN THE MID TO UPPER 60S IN MOST
LOCATIONS FRIDAY AFTERNOON.

FRIDAY NIGHT AND SATURDAY...THE SURFACE RIDGE WILL DRIFT FURTHER
EAST AND OFF THE NEW ENGLAND COAST...WHILE COMPLEX LOW PRESSURE
DRAPED FROM HUDSON BAY TO THE NORTHERN PLAINS BODILY SLIDES EAST
INTO ONTARIO AND QUEBEC PROVINCES. IN BETWEEN THESE TWO SYSTEMS...
A STRENGTHENING WARM AIR ADVECTION REGIME WILL HELP TO TRANSPORT
PROGRESSIVELY WARMER AIR INTO OUR REGION. THIS WILL RESULT IN A
CONSIDERABLY MILDER TEMPERATURES FRIDAY NIGHT WHEN LOWS WILL BE SOME
15 TO 20 DEGREES WARMER THAN THOSE OF THE PREVIOUS NIGHT...AND A
DOWNRIGHT SUMMERLIKE DAY ON SATURDAY WHEN READINGS WILL SURGE INTO
THE LOWER TO MID 70S ACROSS THE NORTH COUNTRY...AND TO THE MID TO
UPPER 70S SOUTH OF LAKE ONTARIO. OTHERWISE...EXPECT LARGELY DRY
WEATHER TO CONTINUE WITH THE BULK OF ANY DEEPER MOISTURE AND WARM
FRONTAL FORCING REMAINING TO OUR NORTH...WITH BREEZY CONDITIONS ALSO
DEVELOPING ON SATURDAY IN RESPONSE TO A TIGHTENING PRESSURE
GRADIENT. DOWNWIND OF THE LAKES...THIS WILL LEAD TO WIND GUSTS INTO
THE 30-35 MPH RANGE SATURDAY AFTERNOON.

SATURDAY NIGHT AND SUNDAY...A MORE SIGNIFICANT SHORTWAVE WILL DROP
INTO THE BROAD UPPER LEVEL TROUGH OVER THE UPPER MISSISSIPPI VALLEY/
UPPER GREAT LAKES...WHICH WILL RESULT IN THIS FEATURE SHARPENING UP
AND DIGGING SOUTHEASTWARD ACROSS THE GREAT LAKES REGION. AT THE
SURFACE...THIS WILL HELP SHUNT THE COMPLEX FRONTAL SYSTEM
EASTWARD...WITH ITS TRAILING COLD FRONTAL BOUNDARY INITIALLY
APPROACHING FAR WESTERN NEW YORK BY SUNDAY MORNING...BEFORE PUSHING
EAST ACROSS THE AREA THROUGH THE COURSE OF THE DAY. THIS WILL RESULT
IN SHOWER CHANCES SPREADING INTO THE AREA FROM WEST TO EAST LATER
SATURDAY NIGHT...FOLLOWED BY THE LIKELIHOOD OF SOME SHOWERS AS THE
FRONT PUSHES THROUGH THE REGION ON SUNDAY...WHEN SOME LIMITED
INSTABILITY MAY ALSO ALLOW FOR THE DEVELOPMENT OF A FEW ISOLATED
THUNDERSTORMS. WITH RESPECT TO TEMPS...THESE WILL REMAIN ABOVE
NORMAL...PARTICULARLY DURING SATURDAY NIGHT WHEN A VERY MILD/BRISK
SOUTHWESTERLY FLOW WILL KEEP OVERNIGHT LOWS FROM FALLING BELOW THE
LOWER TO MID 60S IN MANY LOCATIONS...LEVELS THAT WILL BE SOME 10
TO 15 DEGREES ABOVE LATE SEPTEMBER AVERAGES.

BY SUNDAY EVENING...THE LATEST GUIDANCE SUITE SUGGESTS THAT THE COLD
FRONT AND ITS ATTENDANT BAND OF SHOWERS SHOULD BE LARGELY TO OUR
EAST. A SWATH OF DRY SLOTTING/SUBSIDENCE WORKING IN BEHIND THE FRONT
SHOULD RESULT IN A BRIEF PERIOD OF MAINLY DRY WEATHER IMMEDIATELY
FOLLOWING THE FROPA...BEFORE LOWER-END SHOWER CHANCES RETURN WITH
THE ARRIVAL OF THE MAIN UPPER TROUGH AXIS. OTHERWISE...GOOD COOL AIR
ADVECTION IN THE WAKE OF THE FRONT WILL RESULT IN MUCH COOLER TEMPS
COMPARED TO THOSE OF THE SATURDAY NIGHT...WITH OVERNIGHT LOWS
AVERAGING IN THE UPPER 40S TO LOWER 50S.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
IN THE EXTENDED PORTION OF THE FORECAST...PRONOUNCED UPPER LEVEL
TROUGHING WILL LINGER ACROSS THE GREAT LAKES AND NEW ENGLAND MONDAY
AND TUESDAY. THE RESULTANT COOL CYCLONIC FLOW ACROSS OUR REGION WILL
ONCE AGAIN LEAD TO ANOTHER ROUND OF BELOW NORMAL TEMPERATURES...AS
WELL AS THE POTENTIAL FOR SOME INSTABILITY/LAKE EFFECT CLOUDS AND
SHOWERS. GIVEN THE MORE DISTANT TIME FRAME...HAVE KEPT POPS FOR THIS
PERIOD MUCH MORE BROADBRUSH IN NATURE...AND CONFINED TO THE SLIGHT
CHANCE/LOW CHANCE RANGE FOR NOW.

AFTER THAT...CONDITIONS SHOULD IMPROVE MARKEDLY BY MIDWEEK AS STRONG
RIDGING BUILDS ACROSS THE REGION AT ALL LEVELS. PLENTY OF ASSOCIATED
DRY AIR AND SUBSIDENCE/WARMING ALOFT SHOULD RESULT IN DRY WEATHER...
ALONG WITH TEMPERATURES MODERATING BACK CLOSER TO NORMAL.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
IFR CIGS CONTINUE AT THE KBUF/KIAG TERMINALS AS EXPECTED...WITH LOW
LOW MVFR/MVFR CIGS AT KROC/KART. EXPECT MVFR/IFR CIGS TO REMAIN IN
PLACE FOR MUCH OF THE AFTERNOON ACROSS THE AFOREMENTIONED
TERMINALS...WITH LOW VFR/ISOLATED MVFR CIGS ACROSS THE KJHW
TERMINAL...WHICH WILL PERSIST THROUGH THE AFTERNOON AS WELL. THE
EXCEPTION TO THIS WILL BE ACROSS PORTIONS OF THE NORTH
COUNTRY...WHERE MVFR CIGS SHOULD SCATTER OUT A BIT LATER THIS
AFTERNOON AT THE KART TERMINAL AS DRIER AIR PUSHES SOUTH OUT OF
CANADA COMBINED WITH THE LACK OF LAKE INFLUENCE.

FOR TONIGHT...HIGH PRESSURE SLIDING BY TO OUR NORTH WILL PROMOTE VFR
CONDITIONS ACROSS THE MAJORITY OF OUR REGION. THE EXCEPTION WILL BE
IN THE VALLEYS OF THE SRN TIER WHERE FOG AND/OR LOW STRATUS COULD
DEVELOP LATE.

FRIDAY...ANY MVFR/IFR CIGS/VSBYS ACROSS THE INTERIOR SOUTHERN TIER
(POSSIBLY KJHW) WILL MIX OUT/BURN OFF BY MID MORNING...LEAVING
WIDESPREAD VFR CONDITIONS ACROSS ALL TERMINALS THROUGH 18Z AS A
LARGE AREA OF HIGH PRESSURE DOMINATES THE WEATHER.

OUTLOOK...
FRIDAY NIGHT THROUGH SATURDAY...VFR.
SUNDAY...VFR/MVFR WITH SHOWERS BECOMING LIKELY.
MONDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.

&&

.MARINE...
HIGH PRESSURE WILL BUILD ACROSS THE LAKES IN THE WAKE OF A COLD
FRONT THIS AFTERNOON. THIS WILL PRODUCE A FRESHENING NORTHEAST
WIND...WHICH ON LAKE ONTARIO...WILL RESULT A SHORT WINDOW OF SMALL
CRAFT ADVISORY CONDITIONS FROM HAMLIN BEACH TO IRONDEQUOIT BAY
THROUGH LATE THIS AFTERNOON.

AS HIGH PRESSURE DRIFTS ACROSS TO THE NORTH OF LAKE ONTARIO
TONIGHT...THE WEAKENING SFC PRESSURE GRADIENT WILL ALLOW WINDS AND
WAVES TO SUBSIDE. MODERATE EASTERLIES WITH NEGLIGIBLE WAVES WILL
THEN BE FOUND ACROSS THE LOWER GREAT LAKES ON FRIDAY.

A DEEPENING SOUTHERLY FLOW WILL BECOME ESTABLISHED ACROSS THE LOWER
GREAT LAKES FRIDAY NIGHT AND SATURDAY...AND WHILE THE HIGHEST WAVES
WILL BE FOUND IN CANADIAN WATERS...THE STRONGER WINDS COULD LEAD TO
WIND BASED SMALL CRAFT ADVISORIES.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...FROST ADVISORY FROM 3 AM TO 9 AM EDT FRIDAY FOR NYZ006.
     FREEZE WARNING FROM 3 AM TO 9 AM EDT FRIDAY FOR NYZ007-008.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LOZ043-
         044.

&&

$$

SYNOPSIS...JM/RSH
NEAR TERM...JM/RSH
SHORT TERM...JJR
LONG TERM...JJR/TMA
AVIATION...JM/RSH
MARINE...JM/RSH






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.