National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS61 KBUF 210603
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
203 AM EDT TUE MAY 21 2013

.SYNOPSIS...
A SOUTHWESTERLY FLOW OF WARM AND MORE HUMID AIR WILL CONTINUE ACROSS
THE REGION FOR MUCH OF THIS WEEK...WHILE A FRONTAL BOUNDARY ALSO
STALLS OUT ACROSS NEW YORK STATE AND SETS THE STAGE FOR INCREASING
CHANCES OF SHOWERS AND THUNDERSTORMS. THE MORE UNSETTLED CONDITIONS
WILL LAST THROUGH THURSDAY...BEFORE A COLD FRONT CROSSES THE AREA
AND USHERS IN COOLER AND DRIER WEATHER FOR THE END OF THE WEEK AND
THE MEMORIAL DAY WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 06Z...ONE LEAD CLUSTER OF CONVECTION /THE REMNANTS OF A
DECAYING MCS AND A NEW LINE OF CONVECTION FIRING ALONG ITS OUTFLOW
BOUNDARY/ CONTINUES TO SLIDE EAST ACROSS EASTERN LAKE ONTARIO AND
THE NORTH COUNTRY. MEANWHILE FURTHER TO THE WEST...A SECOND AND
SMALLER CLUSTER OF SHOWERS/EMBEDDED STORMS IS AFFECTING WESTERN LAKE
ONTARIO AND ADJOINING PORTIONS OF ITS SOUTHERN LAKESHORE. BOTH OF
THESE AREAS WILL CONTINUE TO TRANSLATE EAST-NORTHEASTWARD THROUGH
THE REMAINDER OF THE NIGHT...BRINGING A LIKELIHOOD OF SHOWERS/STORMS
TO AREAS FROM THE SOUTHERN LAKESHORE AREAS OF LAKE ONTARIO
NORTHWARD. FURTHER SOUTH...MUCH QUIETER WEATHER WILL PREVAIL WITH
JUST THE RISK OF A FEW ISOLATED SHOWERS NORTH OF THE SOUTHERN
TIER...AND THE SOUTHERN TIER ITSELF LIKELY REMAINING TOTALLY DRY.
HAVE UPDATED THE FORECAST TO REFLECT CURRENT RADAR/SATELLITE IMAGERY
AND THE ABOVE TRENDS...WITH NO REAL CHANGES MADE BEYOND LATE
TONIGHT. THAT IS ALL FOR NOW...REFER TO THE PARAGRAPH BELOW FOR
EXPECTED CONDITIONS ON TUESDAY.

THE UPPER RIDGE AXIS WILL BE OVER OR TO THE EAST OF THE FORECAST
AREA ON TUESDAY AND WILL ALLOW AN INFLUX OF WARMTH AND MOISTURE WITH
DEWPOINTS SURGING TO THE UPPER 60S ACROSS WESTERN NY DURING TUESDAY
AFTERNOON. THE SUPPRESSIVE SUBSIDENCE WILL BE NEARLY ABSENT ON
TUESDAY SO CAN EXPECT CONVECTION TO DEVELOP DURING THE AFTERNOON
ALONG THE LAKE BREEZE BOUNDARIES AND THE INLAND TERRAIN. LAKE COOLED
AIR WILL PROVIDE LAKE SHADOWS WITHIN ABOUT HALF A COUNTY`S WIDTH OF
THE LAKE ERIE AND ONTARIO SHORES. WILL HAVE POPS INCREASING TO THE
LIKELY CATEGORY BY THE END OF THE DAY ON TUESDAY WITH THE CONTINUED
INFLUX OF HIGH THETA-E AIR. HIGH TEMPS ON TUESDAY SHOULD BE IN THE
LOWER TO MID 80S FOR MOST AREAS...LOWER TO MID 70S EXPECTED ACROSS
THE CLOUDIER AND POSSIBLY RAINIER TUG HILL PLATEAU AND EASTERN LAKE
ONTARIO COUNTIES.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
SUMMERY CONDITIONS WILL CONTINUE ACROSS OUR REGION ON WEDNESDAY...
AS A DEEP SOUTHERLY FLOW WILL REMAIN IN PLACE IN ADVANCE OF A
BROAD SFC LOW FOUND OVER LOWER MICHIGAN. WHILE IT WILL BE WARM AND
HUMID WITH TEMPERATURES RESEMBLING THOSE OF JULY...THERE WILL BE
SOME UNSETTLED WEATHER TO DEAL WITH AS WELL. OUR UNSTABLE AIRMASS
WILL CERTAINLY SUPPORT SOME SHOWERS AND THUNDERSTORMS...ALTHOUGH
THE BULK OF THE DAY MAY END UP BEING RAINFREE. LETS LOOK AT THE
PROS AND CONS TO THIS CONVECTION.

WORKING AGAINST WIDESPREAD CONVECTION WILL BE A SHORTWAVE RIDGE THAT
WILL LIFT UP ACROSS OUR REGION. THIS COULD BE A DOUBLE EDGED SWORD
THOUGH...AS THE RIDGE COULD HELP TO THIN SOME OF THE EXPECTED CLOUD
COVER. THAT WOULD LEAD TO GREATER DIURNALLY INDUCED INSTABILITY THAN
IS BEING FORECAST...WHICH IN TURN WOULD LIKELY LEAD TO MORE
AFTERNOON CONVECTION. ON THE OTHER HAND...THE SUBSIDENCE FROM THE
PASSING RIDGE IN TANDEM WITH MOSTLY CLOUDY SKIES COULD MINIMIZE THE
THREAT OF STORMS (AS WAS ALSO EXPRESSED IN A PREVIOUS STORM
PREDICTION CENTER DISCUSSION)...OR AT LEAST HOLD THEM OFF UNTIL MID
TO LATE AFTERNOON.

EITHER WAY YOU SLICE IT...THERE SHOULD BE AT LEAST 500-1000 J/KG OF
SBCAPE BY WEDNESDAY AFTERNOON SO THERE SHOULD BE SHOWERS OR
THUNDERSTORMS TO DEAL WITH AS WE MOVE THROUGH THE DAY. THIS ACTIVITY
WILL LIKELY FOCUS ON TWO AREAS. THE FIRST BEING A NEARLY STALLED
FRONTAL BOUNDARY THAT WILL BE FOUND FROM THE NORTH SHORE OF LAKE
ONTARIO TO THE NORTH COUNTRY...AND THE SECOND BEING A LAKE BREEZE
BOUNDARY THAT SHOULD PUSH EAST OF LK ERIE. THE LATTER WOULD BE OF
MORE CONCERN BECAUSE THIS WOULD BE THE TRIGGER TO RELEASE THE
GREATER INSTABILITY OVER THE WRN COUNTIES. THIS LEADS US TO THE
POTENTIAL FOR SEVERE WEATHER.

LETS STATE RIGHT UP FRONT THAT SPC HAS OUR FORECAST AREA OUTLINED IN
A SLIGHT RISK FOR SEVERE STORMS ON WEDNESDAY. THAT BEING SAID AND
AS WAS THE CASE IN YESTERDAYS MORNING DISCUSSION...AM NOT OVERLY
IMPRESSED WITH THE OVERALL SET UP FOR SEVERE WEATHER. WE COULD HAVE
SUPPRESSED INSTABILITY FROM CLOUD COVER AND ONGOING SHOWER
ACTIVITY...BUT I AM JUST AS UNIMPRESSED WITH 0-3KM BULK SHEAR
(GENERALLY <25 M/S) AND LACKLUSTER MID LEVE LAPSE RATES OF 6 DEG
C/KM. ONE HAS TO LOOK AT A DEEPER LAYER (0-6 KM) TO FIND IMPRESSIVE
BULK SHEAR VALUES OF 35-40 M/S. A TELLING SIGN WILL LIKELY BE HOW
MUCH SUN WE GET DURING THE MORNING AND MIDDAY. THE MAIN THREAT FROM
ANY STRONG TO SEVERE STORMS WOULD BE STRAIGHT LINE WINDS...AND IF WE
CAN GET OUR CAPES UP OVER 1500 J/KG...SOME LARGE HAIL. PWAT VALUES
>1.5 INCHES WILL ALSO LIKELY LEAD TO SOME TORRENTIAL DOWNPOURS...
BUT THERE SHOULD BE ENOUGH WINDS TO MOVE THE STORMS ALONG AND
MINIMIZE THE POTENTIAL FOR HYDRO ISSUES. BOILING THIS ALL DOWN...
WILL MAINTAIN HIGH LIKELY TO CAT POPS BUT WILL REFRAIN FROM ADDING
ANY ENHANCED TSRA WORDING. WILL DEFER THIS TO LATER SHIFTS FOR
FURTHER REVIEW.

ON WEDNESDAY NIGHT...THE AFOREMENTIONED SFC LOW WILL TRACK BY TO OUR
NORTH WHILE THE CONVECTION FROM THE EVENING HOURS WILL GRADUALLY
SUBSIDE WITH THE LOSS OF DAYTIME HEATING AND SUBSEQUENT
STABILIZATION OF THE LOWEST LEVELS. THIS WILL LEAVE A WARM AND DAMP
NIGHT WITH NOCTURNAL TEMPERATURES ONCE AGAIN NOT FALLING OUT OF THE
60S.

THE VARIOUS GUIDANCE PACKAGES THEN START TO DIVERGE ON THE HANDLING
OF THE WAVY FRONTAL BOUNDARY THAT WILL OOZE ACROSS OUR FORECAST AREA
ON THURSDAY. IN PREVIOUS MODEL RUNS...THE ECMWF HAS BEEN THE FASTER
PACKAGE IN BRINGING THE FRONT THROUGH. IT NOW TRAILS THE GFS...AND
FOR WHAT ITS WORTH...THE NAM. THE SECONDARY WAVE ALONG THE TRAILING
FRONT IS WHAT IS OBVIOUSLY THROWING A MONKEY WRENCH INTO THE
MODELS...BUT IN ANY CASE...THE MODELS ARE IN GENERAL AGREEMENT THAT
THERE WILL BE A WEALTH OF LOW LEVEL MOISTURE THAT WILL BE LIFTED IN
FAIRLY WIDESPREAD SHOWERS. JUST DO NOT SEE ENOUGH INSTABILITY TO
HOLD ONTO THE SLGT CHC THAT WE HAVE FOR THUNDER...AS LAPSE RATES ARE
GENERALLY BELOW 6 DEG C/KM BY MID MORNING. WILL COMPROMISE AND LEAVE
THE MENTION FOR THE MORNING ONLY. OTHERWISE...IT WILL BE A WET AND
NOTICEABLY COOLER DAY WITH TEMPERATURES AVERAGING SOME 10 DEG F
LOWER THAN PREVIOUS DAYS. HIGHS SHOULD GENERALLY BE IN THE UPPER 60S
TO LOWER 70S.

WHILE THE WAVY FRONT WILL BE WELL TO OUR EAST THURSDAY NIGHT...THE
SUPPORTING H5 TROUGH WILL BE JUST CROSSING THE LOWER LAKES. THIS
SHOULD KEEP SOME LEFTOVER SHOWERS OVER THE REGION...ESPECIALLY
DURING THE FIRST HALF OF THE NIGHT. MEANWHILE...TEMPERATURES ARE
EXPECTED TO TUMBLE INTO THE 40S...WHICH WILL BE QUITE REFRESHING
AFTER SEVERAL DAYS OF MID JULY-LIKE WEATHER.

FRIDAY WILL FEATURE SEASONABLY COOL CONDITIONS AS H85 TEMPS IN THE
VCNTY OF 4C WILL ONLY SUPPORT AFTERNOON HIGHS AROUND 60 F. WHAT IS
MUCH LESS CERTAIN IS WHETHER ALL OF THE SHOWER ACTIVITY WILL BE
DONE. THE 00Z GFS IS NOW BEING STUBBORN WITH CLEARING OUT THE
SHOWERS AND LEFTOVER CLOUDS...SO WILL HAVE TO KEEP AT LEAST SLGT CHC
POPS OVER THE REGION DURING THE MORNING AND INCREASE OUR CLOUD COVER
A BIT. WILL STILL LEAN MORE ON THE ECMWF SOLUTION THOUGYH...WHICH AT
THIS POINT FAVORS A MORE OPTIMISTIC SCENARIO.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
PLENTY OF SUNSHINE AND SEASONABLY COOL TEMPERATURES WILL BE THE NAME
OF THE GAME THIS WEEKEND AS HIGH PRESSURE WILL SETTLE ACROSS THE
GREAT LAKES. 850MB TEMPS DROPPING TO AROUND 0C SHOULD ONLY YIELD
HIGHS TOPPING OUT IN THE LOWER 60S FOR MOST AREAS ON SATURDAY...
NEARLY 10 DEGREES BELOW NORMAL. LIKEWISE OVERNIGHT LOWS WILL RUN ON
THE CHILLY SIDE WITH READINGS IN THE LOWER 40S ALONG THE LAKE PLAINS
WHILE AREAS FARTHER INLAND ACROSS THE SOUTHERN TIER AND NORTH
COUNTRY COULD DROP INTO MID 30S...POTENTIALLY SETTING THE STAGE FOR
A FROST...PARTICULARLY SATURDAY NIGHT WHEN THE SURFACE HIGH IS
FORECAST TO BE OVERHEAD.

A GRADUAL REBOUND IN TEMPERATURES IS EXPECTED FOR THE LATTER HALF OF
THE WEEKEND AS THE COLDEST AIR ASSOCIATED WITH THE UPPER LEVEL
TROUGH DEPARTS THE REGION AND WARMER AIR BEGINS TO CREEP NORTH FROM
THE OHIO VALLEY ONCE AGAIN. OTHERWISE...EXPECT DRY WEATHER TO
CONTINUE THROUGH THE END OF THE WEEKEND.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...ONE LEAD CLUSTER OF CONVECTION /THE REMNANTS OF A
DECAYING MCS AND A NEW LINE OF CONVECTION FIRING ALONG ITS OUTFLOW
BOUNDARY/ CONTINUES TO SLIDE EAST ACROSS EASTERN LAKE ONTARIO AND
THE NORTH COUNTRY. MEANWHILE FURTHER TO THE WEST...A SECOND AND
SMALLER CLUSTER OF SHOWERS/EMBEDDED STORMS IS AFFECTING WESTERN LAKE
ONTARIO AND ADJOINING PORTIONS OF ITS SOUTHERN LAKESHORE. BOTH OF
THESE AREAS WILL CONTINUE TO TRANSLATE EAST-NORTHEASTWARD THROUGH
THE REMAINDER OF THE NIGHT...BRINGING A LIKELIHOOD OF SHOWERS/STORMS
TO AREAS FROM THE SOUTHERN LAKESHORE AREAS OF LAKE ONTARIO
NORTHWARD...WITH AN ATTENDANT RISK OF LOCALIZED IFR/MVFR CONDITIONS
AND GUSTY WINDS. FURTHER SOUTH...MUCH QUIETER VFR WEATHER WILL
PREVAIL WITH JUST THE RISK OF A FEW ISOLATED SHOWERS NORTH OF THE
SOUTHERN TIER...AND THE SOUTHERN TIER ITSELF LIKELY REMAINING
TOTALLY DRY. LATE TONIGHT...SOME MVFR STRATUS WILL BE POSSIBLE
ACROSS THE SOUTHERN TIER.

DURING THE COURSE OF THE UPCOMING DAY /TUESDAY/...EXPECT MAINLY DRY
VFR CONDITIONS TO PREVAIL DURING THE MORNING...WITH SCATTERED
CONVECTION THEN DEVELOPING ACROSS INTERIOR SECTIONS AND ALONG
LAKE BREEZE BOUNDARIES DURING THE AFTERNOON...SOME OF WHICH COULD
PRODUCE ADDITIONAL BRIEF LOCALIZED REDUCTIONS TO IFR/MVFR.

TONIGHT...SOME ADDITIONAL UPSTREAM CONVECTION MAY THEN RIDE EAST
ALONG A STALLED OUT FRONTAL BOUNDARY AND CROSS THE AREA FROM WEST TO
EAST THIS EVENING...BEFORE QUIETER WEATHER RETURNS FOR THE OVERNIGHT
HOURS.

OUTLOOK...
WEDNESDAY THROUGH THURSDAY...SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS WITH ASSOCIATED MVFR/IFR...OTHERWISE VFR.
FRIDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
SATURDAY...VFR.

&&

.MARINE...
A LINE OF SHOWERS AND THUNDERSTORMS MOVING ACROSS EASTERN MICHIGAN
AND LAKE HURON WILL SHIFT EAST THIS EVENING AND MAY PUSH ACROSS THE
LAKES ARRIVING NEAR MIDNIGHT AND SHIFTING EAST THROUGH THE EARLY
MORNING HOURS.

OTHERWISE...FOR MUCH OF THIS WEEK WINDS WILL REMAIN RELATIVELY LIGHT
AND VARIABLE IN DIRECTION DUE TO A NEARLY STATIONARY FRONTAL
BOUNDARY THAT WILL REMAIN DRAPED ACROSS THE REGION...AS WELL AS THE
DAILY DEVELOPMENT OF LAKE BREEZES. AS A RESULT...WAVE HEIGHTS SHOULD
ALSO REMAIN MINIMAL. OTHERWISE...SHOWER AND THUNDERSTORM
CHANCES WILL INCREASE MARKEDLY FOR THE TUESDAY THROUGH THURSDAY TIME
FRAME. A COLD FRONTAL PASSAGE WILL TURN WINDS TO A NORTHERLY
DIRECTION WITH AN INCREASE IN WAVE HEIGHTS... ESPECIALLY ALONG THE
SOUTH SHORE OF LAKE ONTARIO ON FRIDAY MORNING.

&&

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

&&

$$

SYNOPSIS...JJR
NEAR TERM...JJR/WCH
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...JJR
MARINE...SMITH