FXUS61 KBUF 012059 AAA AFDBUF AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BUFFALO NY 500 PM EDT THU JUL 01 2004 .UPDATE... SEVERE THUNDERSTORM WATCH FOR MUCH OF WESTERN AND NORTH CENTRAL NEW YORK WILL REMAIN IN EFFECT UNTIL 22Z...BUT STRONG LAKE BREEZE OFF LK ERIE WILL KEEP THE NIAGARA FRONTIER PCPN FREE THROUGH THE PERIOD. VISIBLE LOOP HAS THE WELL DEFINED LAKE BREEZE STRETCHING FROM THE LAKE SHORE OF CHAUTAUQUA COUNTY TO FORT ERIE AND BUFFALO TO ROCHESTER. CU ARE EVEN HAVING TROUBLE FORMING WITHIN THIS MARINE AIRMASS WHERE LAPS DISPLAYS ARE GENERALLY SHOWING CAPES <800 J/KG. SOMEWHAT OF A DIFFERENT STORY OVER THE FINGER LAKES REGION. A SOLID DAYS WORTH OF HEATING HAS SENT SFC TEMPS TO MID 80S WITH CAPES NOW 1500-200 J/KG. THIS AREA ONLY NEEDS A TRIGGER...AND THE EASTERN EDGE OF THE LAKE ERIE BREEZE MAY BE JUST THE INGREDIENT. PLENTY OF POPCORN CU SHOWING UP ON THE VIS LOOP...BUT NOTHING OVERLY IMPRESSIVE AT THIS POINT. GIVEN THE HIGH CAPES AND LACK OF CAP... I AM SURE THAT THESE ARE AT LEAST MODERATE/TOWERING CU. FURTHER EAST OVER THE EASTERN LAKE ONTARIO REGION...SOME STORMS HAVE ALREADY MOVED THROUGH THAT REGION WITH ONE REPORT OF PENNY SIZED HAIL OVER SOUTHERN LEWIS COUNTY. DESPITE THE MODIFIED AIRMASS...STRONG STORMS ARE STILL UPSTREAM ALONG THE CANADIAN LAKE SHORE AND THESE ARE HEADING IN THAT DIRECTION. TO SUM IT UP...NEXT HOUR OR TWO COULD BECOME ACTIVE OVER THE FINGER LAKES REGION WITH ADDITIONAL STORMS EAST OF LAKE ONTARIO. FOR THE WESTERN COUNTIES...STORMS PROBABLY WILL NOT GET GOING UNTIL THE LAKE BREEZE DIES OFF LATER THIS EVENING. ORIGINAL AFTERNOON AFD LEFT BELOW. RSH .SHORT TERM (THROUGH SATURDAY)... WITH THE EXCEPTION OF THE WESTERN SOUTHERN TIER COUNTIES...A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR THE AREA THROUGH 6 PM THIS EVENING. CURRENTLY...SHOWERS/THUNDERSTORMS HAVE PRETTY MUCH BLOSSOMED ON SCHEDULE AND IN THE AREAS WE EXPECTED...WITH THE BULK OF THE ACTIVITY ACROSS THE EASTERN LAKE ONTARIO COUNTIES...LAKE ONTARIO...AND SOUTHEASTERN ONTARIO PROVINCE. AS DISCUSSED PREVIOUSLY...THIS IS THE AREA EXPERIENCING THE GREATEST INSTABILITY...THE BEST LOW-LEVEL MOISTURE POOLING...AND THE STRONGEST DYNAMICS FROM THE APPROACHING COLD FRONT/MID LEVEL SHORTWAVE/UPPER JET MAXIMA. FURTHER TO THE SOUTH AND WEST...ONLY ISOLATED ACTIVITY HAS DEVELOPED SO FAR IN THE SOMEWHAT LESS FAVORABLE ENVIRONMENT. THIS IS PARTICULARLY THE CASE DOWNWIND OF LAKE ERIE...WHERE A STIFF SW BREEZE OFF THE LAKE IS HELPING TO KEEP THINGS EVEN MORE STABLE...AS EVIDENCED BY THE SHARP LAKE-EFFECT SHADOW ON VIS SATELLITE IMAGERY. ALTHOUGH THE BEST LIFT/INSTABILITY WILL REMAIN ACROSS THE NORTH COUNTRY FOR THIS EVENT...AS THE SFC TROUGH/ASSOCIATED MID-LEVEL WAVE PUSH FURTHER SE LATE THIS AFTERNOON AND EARLY THIS EVENING...AND AS INSTABILITY INCREASES A LITTLE BIT MORE THROUGH LATE AFTERNOON...WE EXPECT SCATTERED ACTIVITY TO DEVELOP FURTHER SAW INTO THE REST OF THE AREA AND PERSIST INTO AT LEAST THE EARLY EVENING. ACROSS THE FAR WESTERN PART OF THE STATE...THE MOST FAVORED AREA FOR DEVELOPMENT LATE THIS AFTERNOON MAY VERY WELL BE ALONG THE NORTH SIDE OF THE LAKE BREEZE BOUNDARY...AS LOW-LEVEL CONVERGENCE/MOISTURE POOLING ALONG THIS FEATURE MAY BE ENHANCED AS THE WEAK COLD FRONT PUSHES IN FROM THE NW. BOTH THE ETA/GFS ARE CONSISTENT IN BRINGING THE COLD FRONT THROUGH THE AREA BETWEEN 00Z-05Z...WITH THE AXIS OF THE MAIN SHORTWAVE FOLLOWING THROUGH ABOUT AN HOUR OR TWO LATER. AM A LITTLE WARY OF REMOVING POPS BEFORE THE MAIN S/W AXIS CLEARS THE AREA...SO WILL MAINTAIN THEM THROUGH THE WEE HOURS OF THE MORNING ACROSS FAR EASTERN SECTIONS. AGAIN...THE HIGHEST POPS WILL BE ACROSS THE NORTHERNMOST ZONES...CLOSEST TO THE BEST DYNAMICS. ONCE WE GET BEYOND TONIGHT...THINGS WILL TURN MUCH MORE PLEASANT FOR FRIDAY AND SATURDAY AS HIGH PRESSURE BUILDS DOWN ACROSS THE AREA...BRINGING MUCH DRIER CONDITIONS...RELATIVELY LIGHT WINDS AND SEASONABLE TEMPS. ALTHOUGH SKIES LOOK TO BE PARTLY CLOUDY ON BOTH DAYS DUE TO RESIDUAL LOW LEVEL MOISTURE FRI AND SOME PASSING CIRRUS ON SAT...850 TEMPS WILL BE IN THE +10 TO +14 RANGE FRI AND IN THE +13 TO +16 RANGE SAT...ENOUGH TO ALLOW READINGS TO HIT THE M-U 70S FRI AND THE LOW 80S SAT. && .LONG TERM (SATURDAY NT THROUGH THU)... THE 4TH OF JULY ITSELF CONTINUES TO LOOK A LITTLE BETTER THIS AFTERNOON. AS WAS SUSPECTED YESTERDAY...THE SLOWER/FURTHER WESTWARD TREND TO THE TRACK OF THE SFC LOW HAS CONTINUED ON THE GFS...AND IS ALSO SUPPORTED BY THE ETA/OTHER EXTENDED MODELS. IT NOW APPEARS THAT WE WILL HAVE A WARM FRONTAL PASSAGE WITH LIMITED LIFT DURING THE MORNING ON SUNDAY...FOLLOWED BY LITTLE IN THE WAY OF PCPN UNTIL THE COLD FRONT/SFC WAVE APPROACHES LATE IN THE DAY. BULK OF THE PCPN NOW APPEARS TO HOLD OFF UNTIL SUNDAY NIGHT/EARLY MONDAY...AND EVEN THOSE PERIODS DO NOT APPEAR TO BE A TOTAL WASHOUT AS MOST OF THE BETTER DYNAMICS REMAIN TO THE NORTHWEST OF OUR AREA. FOR NOW...WILL CONTINUE TO GO WITH CHC POPS LATE SAT NT/SUNDAY FOLLOWED BY LIKELY SUNDAY NT/EARLY MON...THOUGH WILL BACK OFF A BIT ON THE TIMING/PROBABILITIES...AS WELL AS WORD THINGS AS A "FEW" -SHRA/-TSRA SUN NT/MON DUE TO SOMEWHAT MORE LIMITED DYNAMICS. I SHOULD NOTE THAT IT COULD GET PRETTY WARM (WARMER THAN CURRENTLY ADVERTISED) ON SUNDAY IF WE MANAGE TO GET ANY SUN - AS 850 T'S ARE +18C AND FLOW LOOKS TO BE SOUTHERLY...THOUGH HAVE HELD BACK A BIT ON TEMPS FOR NOW DUE TO UNCERTAINTIES OF THIS...AS WELL AS TO STAY IN LINE WITH GRIDS FROM SURROUNDING OFFICES. REST OF THE FCST PERIOD LOOKS PRETTY MUCH THE SAME AS BEFORE. AFTER SOME LINGERING PCPN FOR MON AM...WE DRY OUT DURING THE AFTERNOON FROM W TO E...THEN STAY THAT WAY UNTIL LATER TUESDAY AFTERNOON WHEN THE NEXT WARM FRONT APPROACHES. OPERATIONAL GFS AND HPC PROGS SWING THIS NEXT FRONTAL SYSTEM ACROSS THE AREA TUES NT AND WED...SO WILL CONTINUE TO DO THIS IN THE FORECAST AS WELL...FINALLY DRYING THINGS OUT FOR THU. && .AVIATION... THE ENTIRE REGION EXCEPT FOR THE SOUTHERN TIER REMAINS UNDER A SEVERE THUNDERSTORM WATCH UNTIL 6PM. DIURNAL CU WILL PRODUCE OCNL CIGS AROUND 4K FT IN LOCATIONS SUCH AS ROC ART AND JHW. HOWEVER BRISK SAW FLOW OFF LAKE ERIE WILL PRECULDE CU DEVELOPMENT AT IAG AND BUF THROUGH EARLY EVENING. AS A COLD FRONT SLIDES SOUTHWARD FROM ONTARIO ACROSS THE REGION IN THE 22Z THROUGH 02Z TIMEFRAME THERE WILL BE POTENTIAL FOR SCT SVR THUNDERSTORMS THAT WILL HAVE THE COULD PRODUCE WIND GUSTS IN EXCESS OF 50 KTS AS WELL AS HAIL. AFTER 02Z THE THUNDERSTORM DEVELOPMENT SHOULD WEAKEN. AREA WILL SEE VFR CIGS AS THE FRONT SLOWLY SLIDES THROUGH THE REGION. THERE IS THE POTENTIAL FOR A BIT OF FOG IN THE SOUTHERN TIER TOWARD MORNING IF THE CIGS CAN BREAK ENOUGH TO ALLOW FOR RADIATIONAL COOLING. VISIBILITY WILL PREVAIL THROUGH MID DAY TODAY. A COLD FRONT APPROACHING FROM THE CENTRAL GREAT LAKES WILL KICK OFF A FEW THUNDERSTORMS LATE THIS AFTERNOON AND EVENING...BUT MOST TAF SITES WILL SEE VFR CONDITIONS. SOUTHWEST WINDS AHEAD OF THE FRONT WILL INCREASE TO 15 TO 25 KNOTS TOWARD LATE MORNING AND CONTINUE THROUGHOUT THE AFTERNOON. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. $$ SHORT/LONG TERM...JJR AVIATION...TAN