000 FXUS61 KBUF 100451 AFDBUF AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BUFFALO NY 1151 PM EST THU FEB 9 2012 .SYNOPSIS... A SOUTHWEST BREEZE WILL REMAIN WITH US RIGHT THROUGH THE OVERNIGHT HELPING TO KEEP LOW TEMPERATURES FOR TONIGHT ABOVE NORMAL THROUGHOUT THE REGION...DESPITE PARTLY CLOUDY SKIES. EARLY MORNING SUNSHINE TOMORROW WILL QUICKLY GIVE WAY TO INCREASED CLOUD COVER AS WE HEAD TOWARD THE MIDDLE OF THE DAY OUT AHEAD OF AN APPROACHING COLD FRONT THAT WILL BRING A SHOT OF SNOW TO THE REGION BEGINNING LATE TOMORROW AFTERNOON AND LASTING THROUGH SATURDAY MORNING...ALONG WITH MUCH COLDER TEMPERATURES AND SOME GUSTY WINDS. && .NEAR TERM /THROUGH FRIDAY/... HIGH PRESSURE OVER THE OHIO VALLEY/VIRGINIAS TONIGHT WILL MAINTAIN DRY WEATHER OVER OUR REGION WHILE A TIGHTENING PRESSURE GRADIENT BETWEEN THIS HIGH PRESSURE AND NEXT SFC TROUGH WILL CONTINUE THE SOUTHWEST WINDS. TEMPERATURES WILL REMAIN ABOVE NORMAL WITH TEMPERATURES DROPPING BACK ONLY INTO THE 20S OVERNIGHT. SOME SHELTERED AREAS OF THE SOUTHERN TIER...AND NORTH COUNTRY MAY DROP INTO THE UPPER TEENS UNDER LIGHTER WINDS. INTERESTINGLY...A BAND OF LAKE INDUCED STRATO-CU HAS FORMED OFF LK ERIE. IT IS INTERESTING IN THAT THE 00Z SOUNDING INDICATED THAT H85 TEMPS WERE ONLY IN THE VCNTY OF -3C...WHICH IS DEFINITELY TOO 'WARM' FOR LAKE INDUCED CONVECTION AT THIS POINT. THIS TEMP IS ABOUT 5 DEG WARMER THAN FORECAST BY THE MAINSTREAM MODELS. THE PROBLEM IS THAT THE H85 LEVEL IS AT THE TOP OF A SUBSIDENCE INVERSION...UNDER WHICH THE BASE IS ABOUT -6C. THIS IS APPARENTLY JUST COLD ENOUGH FOR SOME CLOUD COVER TO DEVELOP. THE CLOUD COVER CAN BE SEEN ON IR IMAGERY...AND DESPITE THE POORER RESOLUTION...CAN BE MORE READILY SEEN ON THE 11-3.9 FOG PRODUCT. IN ANY CASE...HAVE INCREASED CLOUD COVERAGE FOR PARTS OF THE IAG FRONTIER AS A RESULT WHILE ALSO RAISING CLOUD COVER ACROSS THE SRN TIER WHERE SOME LOW LEVEL MOISTURE MAY ADVECT IN FROM OHIO. CLOUDS WILL ALSO THICKEN THROUGH THE DAY FRIDAY AS THE TWO SHORT WAVES OVER CANADA CARVE A DEEP LONG WAVE TROUGH ACROSS THE GREAT LAKES AND NORTHEAST. REFLECTED AT THE SFC WILL BE A SFC LOW ACROSS SOUTHERN CANADA THAT WILL BRING A COLD FRONT TO THE DOORSTEPS OF THE REGION LATE FRIDAY AFTERNOON. AHEAD OF THIS COLD FRONT TEMPERATURES AT 850 HPA DROP TO NEAR -9C...JUST COLD ENOUGH TO SUPPORT LIMITED LACK ENHANCED SNOW AHEAD OF THE SFC COLD FRONT. HOWEVER MOISTURE WILL REMAIN LIMITED AND WILL HAVE JUST A LOW CHC POPS FOR ANY LAKE ENHANCED SNOW AHEAD OF THE SFC TROUGH. MODELS ARE A LITTLE SLOWER WITH THE CROSSING OF THIS COLD FRONT AND WILL HOLD BACK POPS TO JUST CHC ACROSS FAR WESTERN NEW YORK...WITH THE LIKELY TIME PERIOD FOR SNOW TO BE FRIDAY NIGHT. TEMPERATURES TOMORROW WILL BE JUST A FEW DEGREES COOLER THAN THURSDAY'S HIGHS WITH HIGHS IN THE UPPER 30S TO LOWER 40S. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... THE PERIOD WILL FEATURE A PAIR OF COLD FRONTS...BOTH OF WHICH WILL BRING THE THREAT OF SNOW. THE FIRST FRONT WILL SLOWLY CROSS THE REGION FRIDAY NIGHT. MODELS ARE IN FAIRLY GOOD AGREEMENT ON TIMING...WITH NEGLIGIBLE DIFFERENCES AMONG THE NAM/GFS/RGEM. HOWEVER...THE 12Z CONSENSUS IS A TAD SLOWER THAN PREVIOUS RUNS. WHILE THERE WILL BE A SW FLOW AHEAD OF THIS FRONT...IT APPEARS AIR ALOFT WILL NOT BE COLD ENOUGH TO DEVELOP MUCH...OR ANY...LAKE EFFECT NE OF THE LAKES ON FRIDAY EVENING. HOWEVER...WHATEVER MOISTURE DOES DEVELOP ON THE LAKES DURING THE EVENING...SHOULD BE THROWN ONSHORE FOLLOWING THE FRONT...WITH MOST OF THE PRECIPITATION EXPECTED TO BE FOLLOWING THE FRONTAL PASSAGE AS WINDS SHIFT TO THE N-NW. 850 MB TEMPERATURES DROPPING TO AROUND -15C BEHIND THE FRONT WILL DESTABILIZE THINGS WITH RESPECT TO THE LAKES. THIS SHOULD BRING A PERIOD OF SNOW SHOWERS TO MOST LOCATIONS LATE FRIDAY EVENING THROUGH SATURDAY MORNING. IN GENERAL...SNOW ACCUMULATIONS SHOULD BE ON THE LIGHT SIDE...WITH GENERAL ACCUMULATIONS OF AROUND AN INCH. CONSENSUS QPF SUGGESTS SLIGHTLY GREATER ACCUMULATIONS ACROSS THE NIAGARA FRONTIER...WESTERN PORTIONS OF THE SOUTHERN TIER...AND THE NORTH COUNTRY....WHERE 1 TO 3 INCHES CAN BE EXPECTED. THE UPPER LEVEL TROF FORCING THE FRONT WILL NOT MOVE VERY FAST...RESULTING IN A SLOW FRONTAL PASSAGE AS WELL. EXPECT THE FRONT WILL FINALLY PUSH SOUTH AND EAST OF THE REGION SATURDAY MORNING...WITH SNOW SHOWERS LIKELY TO TAPER OFF AS DRIER AIR BUILDS IN ON THE BACK OF THE EXITING UPPER TROF. WHILE SNOW SHOWERS ON SATURDAY SHOULD BE QUICK TO TAPER OFF...IT WILL BE NOTABLY COLDER ACROSS WESTERN NEW YORK. EXPECT CLOUDS WILL LINGER FOR MOST OF THE DAY...AND IN THE COLD FLOW HIGHS SHOULD BE LIMITED TO THE UPPER TEENS TO LOWER 20S...MAKING FOR A BLUSTERY DAY. BEYOND THIS...THERE IS A BIT MORE UNCERTAINTY. IT/S NOT THAT THE MODEL GUIDANCE IS THAT ALL FAR APART...RATHER THAT WESTERN NEW YORK WILL BE ALONG A KEY FRONTAL BOUNDARY...WITH THE EXACT LOCATION OF THIS FRONT KEYING OUR WEATHER. THE FRONT ITSELF WILL BE QUITE IMPRESSIVE...DIVIDING COLD AIR FROM ARCTIC AIR. 850 MB TEMPS WELL BEHIND THIS FRONT DROP BELOW -25C. WHILE OUR CWA WILL NOT GET THIS COLD...IT WILL BE MARKEDLY COLDER BEHIND THIS FRONT. EXPECT THIS BOUNDARY TO DROP TOWARD THE REGION SATURDAY NIGHT...THEN STALL OUT SOMEWHERE NEAR LAKE ONTARIO...BEFORE IT LIFTS BACK TO THE NORTH ON SUNDAY. OUTSIDE OF TEMPERATURES...THE POSITION OF THE FRONT IS MOST IMPORTANT IN DETERMINING WHERE LAKE EFFECT SNOW MAY FALL. THERE WILL BE INSTABILITY AHEAD OF THE FRONTAL BOUNDARY...YIELDING LAKE INDUCED CAPES OF AROUND 400 J/KG. MEANWHILE...THE FRONT WILL MOISTEN THE ATMOSPHERE...ALLOWING LAKE EFFECT TO DEVELOP. THE FRONTAL POSITION WILL DETERMINE WIND DIRECTION...WHICH WILL ULTIMATELY DETERMINE WHERE LAKE SNOWS DEVELOP. DEPENDING ON WHERE THE FRONT STALLS...THERE ALSO MAY BE ADDITIONAL MOISTURE ENHANCEMENT FROM UPSTREAM LAKES. THIS DOES BRING A POTENTIAL FOR SOME LOCALLY SIGNIFICANT LAKE EFFECT SNOWS. GIVEN THE COLD AIR IN PLACE...SNOW GROWTH IS FAVORABLE FOR SNOW RATIOS TO 20:1. THIS SAID...ITS IMPORTANT NOT TO READ TOO MUCH INTO ANY ONE MODEL OR ITS QPF...AS THESE ARE LIKELY TO VARY IN FUTURE MODEL RUNS. SEE THE BEST CHANCE FOR LAKE EFFECT SNOW SHOWERS SATURDAY NIGHT AND SUNDAY MORNING...AND WILL GO WITH LIKELY POPS IN THE MORE TRADITIONAL SNOW BELTS...WITH CHANCE POPS ELSEWHERE. OTHERWISE... OTHERWISE...EXPECT THE COLDEST TEMPERATURES WILL LIKELY STAY NORTH OF BUFFALO AND ROCHESTER...WITH SUNDAY LIKELY TO BE A BIT WARMER THAN SATURDAY. EAST OF LAKE ONTARIO MAY BE A DIFFERENT STORY...WITH A CONSERVATIVE HIGH TEMPERATURE FORECAST IN THE TEENS. THIS SAID...EXPECT BITTERLY COLD TEMPERATURES IF THE FRONT DOES PASS THROUGH...WITH TEMPERATURES IN THE SINGLE DIGITS BEHIND THE FRONT. OVERALL...HAVE LOW CONFIDENCE IN TEMPERATURE FORECASTS FOR SUNDAY GIVEN THE CLOSE PROXIMITY OF THE FRONT. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... IN ALL...IT LOOKS LIKE A FAIRLY QUIET PERIOD...WITH NO MAJOR SYSTEMS ON THE HORIZON. TEMPERATURES SHOULD START OFF SEASONABLY COOL...BUT SHOULD THEN TREND ABOVE NORMAL BY MID WEEK. WHEREVER THE ARCTIC BOUNDARY MAKES IT ON SUNDAY...BY SUNDAY NIGHT IT SHOULD BE NORTH AND EAST OF THE REGION AS HIGH PRESSURE BUILDS NEAR KENTUCKY. THE EXITING UPPER TROF WILL ALLOW HIGH PRESSURE TO RIDGE NORTHWARD INTO THE REGION ON MONDAY AND MONDAY NIGHT. THERE MAY BE SOME LINGERING LAKE SNOWS EAST OF THE LAKES SUNDAY NIGHT INTO MONDAY. BOTH THE GFS AND EUROPEAN TRACK A WEAK LOW TO OUR SOUTH ON TUESDAY...WITH THIS ONLY SUPPORTING CHANCE POPS ON TUESDAY. WHILE 850 MB TEMPERATURES NEAR -6C ARE MARGINALLY COLD ENOUGH FOR LAKE EFFECT...GIVEN THE SYNOPTIC NATURE OF THIS SYSTEM...EXPECT THAT WHAT DOES FALL WILL MOSTLY BE SNOW. EITHER WAY...THIS LOOKS LIKE A LIGHT SNOW EVENT AT BEST. BEYOND THIS...WARMER AIR WILL GRADUALLY BUILD INTO THE REGION AS THERE IS SIMPLY NO REAL COLD AIR UPSTREAM. HIGH PRESSURE WILL LIKELY BRING FAIR WEATHER FOR WEDNESDAY AND THURSDAY. MEANWHILE...TEMPERATURES SHOULD MODERATE...WITH DAYTIME HIGHS LIKELY TO BE IN THE LOWER 40S. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... WHILE VFR CONDITIONS WILL BE IN PLACE FOR THE BULK OF THE REGION OVERNIGHT...MVFR CIGS FROM LAKE INDUCED CLOUD COVER WILL BE PRESENT AT KBUF. THERE WILL ALSO BE THE CHANCE FOR SOME MVFR CIGS ACROSS THE SRN TIER LATE AS LOW LEVEL MOISTURE FROM OHIO WILL TRY TO ADVECT IN OUR DIRECTION. FOR FRIDAY...HIGH CLOUDINESS EARLY IN THE DAY WILL GRADUALLY GIVE WAY TO LOWERING STRATO-CU AS AN ARCTIC FRONT WILL NEAR THE REGION FROM SOUTHERN ONTARIO. THIS FRONT WILL LEAD TO DETERIORATING CONDITIONS LATE FRIDAY AFTERNOON AND EVENING...AS VFR CONDITIONS WILL GIVE WAY TO IFR CIGS/VSBYS FRIDAY NIGHT. OUTLOOK... FRIDAY NIGHT...MVFR/IFR IN SNOW SHOWERS. SATURDAY AND SUNDAY...AREAS MVFR IN SCATTERED SNOW SHOWERS. MONDAY...MAINLY VFR. TUESDAY...MVFR IN CHC OF SNOW. && .MARINE... A TIGHTENING PRESSURE GRADIENT WILL MAINTAIN SCA ON THE LAKES AND THE UPPER NIAGARA RIVER THROUGH THE OVERNIGHT AND FRIDAY. WINDS WILL WEAKEN SOME LATER FRIDAY AS THE COLD FRONT NEARS...THOUGH WAVES 4 FEET AND ABOVE WILL LIKELY REMAIN INTO THE OVERNIGHT TIME PERIOD ON FRIDAY NIGHT. WESTERLY WINDS WILL FRESHEN ONCE AGAIN ON SATURDAY AS THE GRADIENT TIGHTENS UP ACROSS THE REGION BETWEEN HIGH PRESSURE BUILDING OVER THE NATION/S MID-SECTION AND LOW PRESSURE OFF THE EAST COAST. THIS WILL RESULT IN ADDITIONAL SMALL CRAFT ADVISORY CONDITIONS THAT SHOULD PERSIST THROUGH THE WEEKEND. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST SATURDAY FOR LEZ040-041. SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR LEZ020. SMALL CRAFT ADVISORY UNTIL 4 AM EST SATURDAY FOR LOZ043>045. SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR LOZ042. && $$ SYNOPSIS...JM NEAR TERM...RSH/THOMAS SHORT TERM...APFFEL LONG TERM...APFFEL AVIATION...RSH MARINE...THOMAS