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 231136
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
736 AM EDT WED APR 23 2014

.SYNOPSIS...
A SECONDARY COLD FRONT WILL SETTLE ACROSS THE REGION THIS MORNING
WITH SCATTERED RAIN SHOWERS AND DRIZZLE...THEN HIGH PRESSURE OVER
THE UPPER GREAT LAKES WILL DRIFT EAST AND CLEAR OUR SKIES DURING THE
AFTERNOON AND EVENING. WHILE IT WILL BE SEASONABLY COOL
TODAY...MERCURY LEVELS WILL STEADILY CLIMB DURING THE COURSE OF THE
WEEK. THE NEXT CHANCE FOR RAIN COMES ON FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
A SURFACE TROUGH/SECONDARY COLD FRONT REMAINS E-W ACROSS LAKE
ONTARIO TO A PARENT LOW CENTERED OVER NORTHERN MAINE AS OF 11Z THIS
MORNING. AREA RADARS ARE SHOWING WIDESPREAD RAIN SHOWERS PIVOTING
SOUTH ACROSS WESTERN AND CENTRAL NEW YORK FROM LAKE ONTARIO/ST.
LAWRENCE VALLEY ASSOCIATED WITH SOME LOW LEVEL MOISTURE CONVERGENCE
ALONG AND AHEAD OF THE SURFACE TROUGH COMBINED WITH SOME UPSLOPE
FLOW OFF THE LAKE. AVERAGE RAIN TOTALS THROUGH THIS MORNING WILL RUN
0.10-0.25 INCHES. THE RAIN SHOWERS ARE EXPECTED TO MAINLY PIVOT JUST
TO THE NORTH/EAST OF THE SOUTHERN TIER COUNTIES WITH ONLY A CHANCE
FOR SOME DRIZZLE WITH A MOIST FLOW OFF LAKE ERIE. THERE MAY BE SOME
PATCHY AREAS ACROSS THE SOUTHERN TIER WHERE THE TEMP DROPS TO OR
JUST BELOW FREEZING AND SOME FREEZING DRIZZLE/WET SNOW IS POSSIBLE
BUT NO ACCUMULATIONS ARE EXPECTED AS LOW LEVEL MOISTURE REMAINS
BELOW THE PRIME DENDRITIC SNOW GROWTH ZONE AND WARMER THAN -10C
WHICH SUPPORTS DRIZZLE OVER PURE SNOW.

LATER THIS MORNING EXPECT THE SURFACE TROUGH/FRONT TO PIVOT SOUTH
AND EAST OF THE FORECAST AREA WITH JUST A CHANCE OF SOME LINGERING
DRIZZLE OR SCATTERED RAIN SHOWERS AND LINGERING CLOUD COVER IN THE
UPSLOPE NORTHWEST FLOW OFF THE LAKES. A RIDGE OF ARCTIC HIGH
PRESSURE EXTENDS OVER THE UPPER MIDWEST THIS MORNING AND IS FORECAST
TO SHIFT EAST THROUGH THE DAY. BEHIND THE SURFACE TROUGH THIS WILL
HELP ADVECT COOLER AND DRIER AIR ACROSS NEW YORK WHICH WILL ACT TO
ERODE CLOUD COVER AND SHOWERS FROM THE LAKE SHORES INLAND. SUNSHINE
SHOULD BREAK OUT ACROSS WNY BY EARLY AFTERNOON AND ACROSS CNY BY
EARLY EVENING. THE COLDER AIR ADVECTING ACROSS OUR AREA TODAY WILL
KEEP OUR SURFACE TEMPS ON THE CHILLY SIDE WITH HIGHS NOT EXPECTED TO
BREAK OUT OF THE 40S OR ABOUT 10 DEGREES BELOW NORMAL. A BREEZY
NORTHWEST FLOW WILL MAKE IT FEEL EVEN CHILLIER WITH WIND CHILLS IN
THE MID 30S.

TONIGHT THE RIDGE OF HIGH PRESSURE BUILDS OVER NEW YORK STATE WITH
CLEAR SKIES AND LIGHT WINDS. EXPECT GOOD RADIATIONAL COOLING WITH
FALLING DEWPOINTS HELPING TEMPERATURES TO DIP INTO THE MID 20S
INLAND TO LOW 30S TOWARD THE LAKE SHORES OVERNIGHT.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
LOW AMPLITUDE RIDGING WILL SLIDE ACROSS THE GREAT LAKES THURSDAY.
UPPER LEVEL NORTHWEST CONFLUENT FLOW...WITH GOOD SUBSIDENCE/DRYING AS
PRECIPITABLE WATER VALUES LESS THAN QUARTER OF AN INCH...WILL
SUPPORT A DAY OF ABUNDANT SUNSHINE. THE AIRMASS WILL MODERATE A
BIT...BUT WITH THE SLOWLY DEPARTING 850 MB THERMAL TROUGH...850 MB
TEMPERATURES WILL STILL REMAIN IN THE NEGATIVE SINGLE DIGITS.
THEREFORE...DESPITE THE SUNSHINE HIGHS LIKELY ONLY REACHING THE MID
50S IN MOST AREAS BY MID TO LATE AFTERNOON. A NORTHWEST GRADIENT
ONSHORE FLOW WILL KEEP AREAS ALONG BOTH THE LAKE ONTARIO AND LAKE
ERIE SHORELINE COOLER.

INCREASING MID/HIGH CLOUDINESS EXPECTED THURSDAY NIGHT WITH
DEVELOPING WARM AIR ADVECTION PATTERN AHEAD OF APPROACHING SURFACE
LOW AND MID LEVEL TROUGH. STILL SOME MODEL DIFFERENCES ON HOW MUCH
PRECIPITATION WILL BE REALIZED WITH THIS FIRST PUSH OF WARM AIR
ADVECTION LATE THURSDAY NIGHT. INITIALLY DRY AMBIENT AIRMASS...BUT
TOP DOWN MOISTENING DURING THE OVERNIGHT HOURS SHOULD RESULT IN
SHOWERS DEVELOPING INTO THE WEST BY FRIDAY MORNING.

AN AREA OF SHOWERS IS EXPECTED TO GROW IN COVERAGE DURING THE FIRST
HALF OF FRIDAY AS THE MID LEVEL TROUGH AND ASSOCIATED MOISTURE
PLUME/850-700 MB THETA-E RIDGE AXIS MOVES THROUGH. MEAGER MID LEVEL
LAPSE RATES/SLIGHTLY POSITIVE SHOWALTER INDEX SUPPORTS LEAVING OUT
THE MENTION OF THUNDER.

PRONOUNCED MID LEVEL DRY SLOT WITHIN WESTERLY FLOW DEVELOPS BY
FRIDAY AFTERNOON...SETTING US UP FOR SNEAKY MILDER DAY WITH GOOD
MIXING. HIGH TEMPERATURES COULD GET WELL INTO THE 60S...A FEW  70
PLUS READINGS ARE CERTAINLY IN PLAY IF SKIES CAN OPEN UP QUICKLY
ENOUGH...BUT THERE ARE SOME TIMING CONCERNS WITH THE APPROACH OF A
SECONDARY COLD FRONT.

AN UPPER LEVEL TROUGH AND SECONDARY FRONT PUSH ACROSS THE EASTERN
GREAT LAKES ON FRIDAY NIGHT. THIS WILL HELP TO ENHANCE RAIN SHOWER
ACTIVITY ACROSS WESTERN AND CENTRAL NEW YORK...ESPECIALLY IN FAVORED
UPSLOPE AREAS DOWNWIND OF THE LAKES.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
MEDIUM RANGE MODEL GUIDANCE CONTINUES TO STRUGGLE WITH THE SYNOPTIC
SCALE DETAILS FOR NEXT WEEKEND...WITH BOTH THE GFS AND ECMWF SHOWING
FAIRLY WIDE SWINGS FROM RUN TO RUN. GIVEN THE MODEL DISAGREEMENT...
THE BEST COURSE OF ACTION IS TO STAY FAIRLY CLOSE TO THE PREVIOUS
FORECAST UNTIL BETTER MODEL CONSISTENCY IS SEEN.

LOOKING IN MORE DETAIL...THE GFS REMAINS MUCH FARTHER SOUTH WITH A
STRONG MID LEVEL TROUGH FRIDAY NIGHT AND SATURDAY AS IT SWINGS
THROUGH THE GREAT LAKES AND NEW ENGLAND. THE GFS IS ALSO MUCH
STRONGER WITH A SURFACE REFLECTION. THE ECWMF IS FARTHER NORTH WITH
THE MID LEVEL TROUGH AND MUCH WEAKER WITH THE SURFACE SYSTEM...
ALTHOUGH IT WOULD STILL PRODUCE A FEW SHOWERS SATURDAY. THE GEFS
ENSEMBLE MEMBERS SHOW A VARIETY OF SOLUTIONS RANGING FROM THE
OPERATIONAL GFS AND OPERATIONAL ECMWF TO EVERYTHING IN BETWEEN. IN
SHORT...CONFIDENCE IS FAIRLY HIGH ON SOME SORT OF SYSTEM FOR
SATURDAY BUT THE TRACK AND INTENSITY IS STILL VERY UNCERTAIN. WITH
THIS IN MIND HAVE JUST KEPT POPS IN THE HIGH CHANCE RANGE.
TEMPERATURES WILL BEGIN TO PULL BACK ON SATURDAY...WITH THE CORE OF
THE COOL DOWN LIKELY TO ARRIVE SATURDAY NIGHT AND SUNDAY. BY THIS
TIME THE NEW 12Z ECMWF HAS MADE A DRAMATIC CHANGE TO PREVIOUS
FORECASTS AND BECOMES OUT OF PHASE WITH THE GFS AND MOST ENSEMBLE
MEMBERS. THE NEW ECMWF BECOMES MUCH LESS AMPLIFIED WITH ITS
NORTHEAST CONUS TROUGH...WHICH ALLOWS THE CENTRAL CONUS CUTOFF TO
GET CLOSE ENOUGH TO PRODUCE SHOWERS SUNDAY AND MONDAY. GIVEN THE
MAJOR CHANGE FROM PREVIOUS RUNS...WE WILL DISCARD THE 12Z ECMWF
SOLUTION AND KEEP SUNDAY AND MONDAY MAINLY DRY. SUNDAY WILL LIKELY
BE THE COOLEST DAY BEFORE SOME MODERATION EARLY NEXT WEEK ALTHOUGH
TEMPERATURES WILL STILL REMAIN BELOW AVERAGE.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AN AREA OF LOW PRESSURE WILL CONTINUE TO TRACK EAST ACROSS MAINE
THIS MORNING WHILE AN ASSOCIATED SURFACE TROUGH/COLD FRONT PIVOTS
SOUTH ACROSS LAKE ONTARIO. RAIN SHOWERS/DRIZZLE WILL SWEEP ACROSS
WESTERN AND NORTH CENTRAL NEW YORK THIS MORNING AHEAD OF THE
FRONT WITH MVFR/IFR CIGS. BEHIND THE FRONT DRIZZLE/SHRA AND LOW CIGS
WILL LINGER THROUGH THE MORNING HOURS. A RIDGE OF HIGH PRESSURE WILL
SHIFT EAST FROM THE WESTERN GREAT LAKES TODAY AND CLEAR SKIES OUT TO
VFR BY LATE AFTERNOON/EARLY EVENING. SKC WILL PREVAIL OVERNIGHT WITH
SOME HIGH CLOUDS POSSIBLY MOVING IN ACROSS FAR WESTERN NY LATE.

OUTLOOK...
WEDNESDAY NIGHT AND THURSDAY...VFR.
FRIDAY THROUGH SUNDAY...VFR/MVFR. A CHANCE OF SHOWERS.

&&

.MARINE...
LOW PRESSURE WILL DRIFT ACROSS MAINE THIS MORNING BEFORE MAKING ITS
WAY ACROSS NOVA SCOTIA LATER TODAY WHILE HIGH PRESSURE OVER THE
MISSISSIPPI VALLEY WILL SLOWLY MOVE EAST. THE RELATIVELY TIGHT SFC
PRESSURE GRADIENT BETWEEN THE TWO SYSTEMS WILL PROMOTE MODERATE TO
FRESH NORTHWESTERLIES ON LAKES ERIE AND ONTARIO...RESULTING IN SMALL
CRAFT ADVISORIES FOR ALL OF THE NEW YORK NEARSHORE WATERS.

AS THE SFC HIGH DRIFTS ACROSS THE LOWER GREAT LAKES TONIGHT...WINDS
WILL WEAKEN WITH ADVISORIES EXPIRING FROM WEST TO EAST. LIGHT WINDS AND
NEGLIGIBLE WAVES WILL BE FOUND ON THE LOWER GREAT LAKES ON THURSDAY.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LEZ040-
         041.
         SMALL CRAFT ADVISORY UNTIL 11 AM EDT THURSDAY FOR
         LOZ043>045.
         SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR
         LOZ042.

&&

$$

SYNOPSIS...SMITH
NEAR TERM...SMITH
SHORT TERM...TMA
LONG TERM...HITCHCOCK
AVIATION...SMITH
MARINE...RSH/SMITH







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