Area Forecast Discussion
Issued by NWS Buffalo, NY

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000
FXUS61 KBUF 071437
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
937 AM EST SUN FEB 7 2016

.SYNOPSIS...
TODAY WILL LIKELY BE THE NICEST WEATHER DAY OF THE WEEK...AS
UNIMPRESSIVE HIGH PRESSURE WILL GUARANTEE DRY WEATHER WHILE
ENCOURAGING TEMPERATURES TO CLIMB WELL ABOVE NORMAL. A LARGE STORM
SYSTEM DEVELOPING OVER THE UPPER GREAT LAKES WILL THEN DRIFT OVER
OUR REGION DURING THE NEXT SEVERAL DAYS...AND THIS WILL LEAD TO
FREQUENT AND LARGELY INCONSEQUENTIAL SNOWS. TEMPERATURES WILL
GENERALLY TREND LOWER AS WE WORK OUR WAY THROUGH THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
SKIES ARE SUNNY ACROSS MOST OF THE REGION THIS MORNING...WITH THE
EXCEPTION OF THE EASTERN LAKE ONTARIO REGION WHERE LINGERING LAKE
EFFECT CLOUDS ARE LIFTING NORTHWARD IN THE SOUTHERLY FLOW.
TEMPERATURES WILL WARM TODAY AS THE NEARLY FULL SUNSHINE GRADUALLY
GIVES WAY TO MID-HIGH CLOUDS WHICH ARE APPROACHING FROM THE WEST.

A PAIR OF VIGOROUS SHORTWAVES OVER THE NORTHERN PLAINS AND CANADIAN
PRAIRIES THIS MORNING WILL TRACK SOUTHEAST TODAY AND CARVE OUT A
FRESH TROUGH OVER THE UPPER MISSISSIPPI VALLEY. WHILE THIS WILL KEEP
A LOW AMPLITUDE RIDGE MOVING TO THE EAST ACROSS OUR REGION...IT WILL
ALSO START TO BACK OUR MID LEVEL FLOW. THIS WILL SLOW THE EASTWARD
ADVANCE OF MID LEVEL CLOUD COVER THAT IS FOUND BACK ACROSS LOWER
MICHIGAN...SO THAT THE BULK OF TODAY SHOULD FEATURE A FAIR AMOUNT OF
SUN. THESE CLOUDS WILL GRADUALLY MAKE THEIR WAY ACROSS THE FAR
WESTERN COUNTIES AFTER LUNCHTIME.

RE-FOCUSING ON THE EASTERN LAKE ONTARIO REGION...HIGH PRESSURE
CENTERED NEAR JAMES BAY WILL PUSH A WEAKENING ARCTIC FRONTAL
BOUNDARY OVER SOUTHERN ONTARIO THIS MORNING...THEN SOUTH ACROSS THE
LAKE AND THE NORTH COUNTRY WHERE IT WILL STALL LATE TODAY. GIVEN
THAT THERE IS STILL A FAIR AMOUNT OF MID LEVEL MOISTURE IN THAT
REGION WITH MORE ADVECTING IN FROM UPSTREAM...ANY WEAK LIFT FROM
THIS FRONT SHOULD HELP TO KEEP SKIES PARTLY/MOSTLY CLOUDY. THIS
WILL ESPECIALLY BE THE CASE NORTH OF WATERTOWN TOWARDS THE
THOUSAND ISLANDS. WHILE THE FRONT WILL LIKELY PLAY A PART IN THE
SKY COVER FOR THAT REGION...THE COLDER AIR IN ITS WAKE IS NOT
EXPECTED TO MAKE IT MUCH FURTHER SOUTH THAN MASSENA.

SPEAKING OF TEMPERATURES...WEAK WARM ADVECTION TAKING PLACE BETWEEN
THE TWO STORM SYSTEMS WILL MODIFY OUR H85 TEMPS TO BETWEEN -2 AND
-4C. THIS IN COMBINATION WITH AT LEAST PARTIAL SUNSHINE WILL SUPPORT
AFTERNOON MAX TEMPS IN THE MID 40S ACROSS THE WRN COUNTIES...WITH
EVEN MILDER CONDITIONS POSSIBLE IN THE GENESEE VALLEY. MEANWHILE THE
MERCURY WILL TOP OUT IN THE UPPER 30S TO NEAR 40 EAST OF LK ONTARIO.

TONIGHT...THE AFOREMENTIONED SHORTWAVES WILL DIG INTO THE BASE OF A
RAPIDLY DEEPENING LONGWAVE TROUGH. IN FACT...A CLOSED LOW SHOULD
TAKE SHAPE IN THE VCNTY OF WISCONSIN BY DAYBREAK. AT THE SFC...THE
ARCTIC COLD FRONT WILL ESSENTIALLY WASH OUT OVER THE EASTERN LAKE
ONTARIO REGION WHILE A BROAD SFC LOW WILL DRIFT ACROSS THE U.P OF
MICHIGAN. THIS SYNOPTIC SET UP WILL SHARPEN THE SOUTHERLY GRADIENT
OVER THE LOWER GRADIENT...FURTHER DETERRING PCPN FROM MAKING ITS WAY
EASTWARD AHEAD OF A SFC OCCLUSION. WHILE THIS WILL KEEP OUR FORECAST
AREA PCPN FREE THROUGH THE OVERNIGHT...CLOUDS WILL INCREASE AND
THICKEN ACROSS THE FORECAST...PARTIALLY ENHANCED BY AN INCREASINGLY
DIVERGENT UPPER LEVEL FLOW.

TEMPERATURES ACROSS OUR REGION TONIGHT WILL AVERAGE SOME 15 DEG F
ABOVE NORMAL EARLY FEBRUARY LEVELS...AS LOWS ARE ONLY EXPECTED TO BE
IN THE UPPER 20S TO LOWER 30S. ITS PROBABLY WORTH NOTING THAT THE
BULK OF THE TEMPERATURE DROP FOR TONIGHT WILL TAKE PLACE BEFORE
MIDNIGHT...AS THE SOUTHERLY FLOW WILL HELP TO STABILIZE THE MERCURY
THROUGH THE WEE HOURS OF THE MORNING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
A MID LEVEL CLOSED LOW WILL MOVE FROM SOUTHERN WISCONSIN EARLY
MONDAY MORNING TO THE OHIO VALLEY BY TUESDAY MORNING BEFORE OPENING
UP INTO A BROAD MID LEVEL TROUGH DURING THE MIDDLE OF THE WEEK. AT
THE SURFACE A WEAKENING LOW WILL MOVE INTO THE CENTRAL LAKES MONDAY
AND THEN GIVE WAY TO WEAK SECONDARY COASTAL CYCLOGENESIS MONDAY
NIGHT. THIS WILL LEAVE BEHIND A WELL DEFINED INVERTED TROUGH ACROSS
THE LOWER LAKES CONNECTING THE OLD PARENT LOW WITH THE COASTAL LOW.
THE INVERTED TROUGH WILL CONTINUE TO PROVIDE A DIFFUSE FOCUS FOR
WEAK CONVERGENCE MONDAY NIGHT THROUGH TUESDAY NIGHT.

LOOKING AT THE DETAILS...ON MONDAY THE APPROACH OF THE MID LEVEL
CLOSED LOW AND ASSOCIATED DPVA AND UPPER LEVEL DIVERGENCE WILL
PROVIDE AN INCREASE IN LARGE SCALE ASCENT BY MONDAY AFTERNOON ACROSS
WESTERN NY...WITH THIS RELATIVELY WEAK FORCING SPREADING EAST ACROSS
THE REMAINDER OF THE AREA MONDAY NIGHT. AN OCCLUDED FRONT AT THE
SURFACE WILL GRADUALLY MOVE INTO WESTERN NY AND PROVIDE SOME
ADDITIONAL LOW LEVEL CONVERGENCE. EXPECT RELATIVELY LIGHT PRECIP TO
GRADUALLY SPREAD INTO WESTERN NY DURING THE LATE MORNING AND EARLY
AFTERNOON...THEN REACH THE GENESEE VALLEY BY LATE AFTERNOON OR
EARLY EVENING BEFORE REACHING CENTRAL NY AND THE NORTH COUNTRY
OVERNIGHT.

BOUNDARY LAYER TEMPS ARE QUITE MILD INITIALLY ON MONDAY...SO EXPECT
A RAIN/WET SNOW MIX OR EVEN JUST RAIN AT THE ONSET ACROSS WESTERN
NY. PRECIPITATION WILL SLOWLY TRANSITION OVER TO SNOW MONDAY NIGHT
AS WEAK COLD ADVECTION SPREADS INTO THE AREA. EXPECT THE TRANSITION
TO BE ELEVATION DEPENDENT...WITH THE HIGHER TERRAIN GOING TO ALL
SNOW FIRST...AND THE LAKE PLAINS CHANGING TO ALL SNOW LAST. THE MILD
BOUNDARY LAYER TEMPS WILL PREVENT ANY ACCUMULATION IN MOST AREAS
MONDAY WITH JUST A COATING POSSIBLE ON THE HILLS OF THE WESTERN
SOUTHERN TIER. MONDAY NIGHT EXPECT A COATING OF ACCUMULATION ACROSS
LOWER ELEVATIONS AND AROUND AN INCH ACROSS HIGHER TERRAIN.

TUESDAY AND TUESDAY NIGHT THE INVERTED TROUGH WILL REMAIN ACROSS THE
AREA AS THE SECONDARY COASTAL LOW TAKES SHAPE. THIS WILL LEAVE
BEHIND WEAK/DIFFUSE FORCING PRODUCING AREAS OF LIGHT SNOW. THE WEAK
NATURE OF THE FORCING AND STILL MARGINAL BOUNDARY LAYER TEMPS DURING
THE DAY TUESDAY WILL KEEP ANY ADDITIONAL ACCUMULATIONS AN INCH OR
LESS...WITH SIMILAR LIGHT AMOUNTS TUESDAY NIGHT.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
WEDNESDAY AND THURSDAY THE LOWER LAKES WILL REMAIN UNDER THE
INFLUENCE OF THE BROAD MID LEVEL TROUGH. AT THE SURFACE AN INVERTED
TROUGH WILL REMAIN IN PLACE ACROSS THE LOWER LAKES WHILE SEVERAL
WEAK WAVES OF LOW PRESSURE DEVELOP ALONG THE EAST COAST. THE
INVERTED TROUGH IS FORECAST TO SHARPEN WEDNESDAY NIGHT AND MOVE
SOUTH ACROSS THE LOWER LAKES AS A KICKER SHORTWAVE ROUNDS INTO THE
LONGWAVE TROUGH.

THE SHARPENING OF THE INVERTED TROUGH WILL ACT TO ENHANCE LOW LEVEL
CONVERGENCE LATER WEDNESDAY AND WEDNESDAY NIGHT. COLD ADVECTION WILL
ALSO INCREASE THE CONTRIBUTION OF LAKE MOISTURE AND INSTABILITY AS
LAKE INDUCED EQUILIBRIUM LEVELS STEADILY RISE. GIVEN THE FORECAST
PATTERN EVOLUTION...WEDNESDAY NIGHT AND THURSDAY WILL LIKELY BE THE
TIME FRAME OF BEST SNOW ACCUMULATIONS FROM THIS SYSTEM. IN MOST AREAS
THE ACCUMULATIONS WILL STILL BE MODEST...BUT THE COMBINATION OF LAKE
ENHANCEMENT AND UPSLOPE FLOW MAY LEAD TO HEAVIER ACCUMULATIONS
ACROSS THE HIGHER TERRAIN OF THE CHAUTAUQUA RIDGE EAST OF LAKE ERIE.
LAKE ENHANCEMENT MAY ALSO BRING BETTER ACCUMULATIONS TO AREAS
ALONG THE SOUTH SHORE OF LAKE ONTARIO.

LATER THURSDAY AND THURSDAY NIGHT THIS SYSTEM FINALLY PULLS INTO THE
CANADIAN MARITIMES WITH SYNOPTIC SCALE SNOW ENDING FROM WEST TO
EAST. LAKE EFFECT SNOW SHOWERS WILL CONTINUE SOUTHEAST OF BOTH LAKES
AS 850MB TEMPS CONTINUE TO DROP TO AROUND -20C.

FORECAST UNCERTAINTY INCREASES SOME FRIDAY INTO THE WEEKEND WITH THE
HANDLING OF A TRUE ARCTIC AIRMASS. THE 00Z ECMWF REMAINS CONSISTENT
WITH PREVIOUS RUNS IN DROPPING THE CORE OF A FRIGID AIRMASS ACROSS
THE LOWER LAKES AND NEW ENGLAND THIS WEEKEND WITH 850MB TEMPS
BOTTOMING OUT AROUND -30C. THESE FORECAST TEMPERATURES ALOFT ARE ON
PAR WITH THE COLDEST EVER RECORDED IN THE MONTH OF FEBRUARY AT KBUF.
THE 00Z GFS DIRECTS THE CORE OF THE COLD THROUGH QUEBEC AND INTO
NORTHERN MAINE...WITH A COLD BUT LESS EXTREME AIRMASS MOVING INTO
OUR REGION.

GIVEN THE MODEL UNCERTAINTY WILL CONTINUE WITH A RELATIVELY
CONSERVATIVE FORECAST WITH HIGHS IN THE LOWER TEENS ON SATURDAY WITH
SINGLE NUMBERS ACROSS THE NORTH COUNTRY. IF THE COLDER ECMWF
SOLUTION VERIFIES THIS WILL NEED TO BE ADJUSTED SIGNIFICANTLY
DOWNWARD. THE FRIGID AIRMASS WILL PRODUCE SOME LAKE EFFECT SNOW
SHOWERS SOUTHEAST OF THE LAKES...BUT AIRMASSES THIS COLD ARE ALSO
VERY DRY AND THIS WILL LIMIT ACCUMULATIONS DESPITE THE STRONG
INSTABILITY.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
OUTSIDE OF SOME LINGERING LAKE EFFECT CLOUDS WILL WILL LIFT ACROSS
ART LATE THIS MORNING...WEAK HIGH PRESSURE WILL KEEP FAIR VFR
CONDITIONS IN PLACE ACROSS THE REGION. MID LEVEL CLOUD COVER WILL
GRADUALLY INCREASE OVER THE FAR WESTERN COUNTIES DURING THE
AFTERNOON.

WHILE A LARGE STORM SYSTEM WILL TAKE SHAPE ACROSS THE UPPER GREAT
LAKES TONIGHT...FAIR WEATHER WILL REMAIN IN PLACE OVER OUR REGION.
CLOUDS WILL LOWER AND THICKEN THOUGH DURING THE COURSE OF THE
NIGHT...ESPECIALLY OVER THE WESTERN COUNTIES.

OUTLOOK...
MONDAY...MVFR. RAIN OR SNOW LIKELY.
MONDAY NIGHT THROUGH THURSDAY...MVFR/IFR IN PERIODS OF SNOW.

&&

.MARINE...
WEAK RIDGING OVER THE LOWER GREAT LAKES WILL PRODUCE GENTLE TO
MODERATE BREEZES TODAY...AS WAVES WILL AVERAGE WELL BELOW SMALL
CRAFT ADVISORY LEVELS.

WHILE A LARGE STORM SYSTEM WILL DEVELOP OVER THE UPPER GREAT LAKES
LATE TODAY AND TONIGHT...THE SFC PRESSURE GRADIENT WILL REMAIN WEAK
OVER THE LOWER GREAT LAKES. THIS WILL KEEP GENTLE TO OCCASIONALLY
MODERATE BREEZES IN PLACE.

ON MONDAY...THE APPROACHING STORM SYSTEM WILL FRESHEN AN EAST TO
SOUTHEAST FLOW OVER THE LOWER GREAT LAKES...PARTICULARLY LAKE
ONTARIO. THE SOMEWHAT HIGHER WINDS ARE NOT EXPECTED TO BE A PROBLEM
THOUGH...AS THE FLOW WILL KEEP THE HIGHEST WAVES IN CANADIAN WATERS.

&&

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

&&

$$

SYNOPSIS...RSH
NEAR TERM...APFFEL/RSH
SHORT TERM...HITCHCOCK
LONG TERM...HITCHCOCK
AVIATION...APFFEL/RSH
MARINE...RSH


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