Severe Thunderstorm Warning 15, NWS Buffalo, NY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
230 PM EDT MON JUL 5 1999

THE TEMPERATURES HAVE ALREADY WARMED TO ABOUT 90 DEGREES ACROSS MUCH
OF WESTERN AND CENTRAL NEW YORK...BUT RESIDENTS IN THE IMMEDIATE
BUFFALO AREA ARE ENJOYING READINGS IN THE LOWER 80S WITH A BRISK
SOUTHWEST WIND OFF OF LAKE ERIE. THE VISIBLE SATELLITE IMAGE SHOWS A
BEAUTIFUL SHADOW  DOWNWIND OF LAKE ERIE WITH A LINE OF CU ALONG THE
SOUTHERN AND EASTERN EDGE OF THE LAKE BREEZE. BUT THE CU ARE NOT
SHOWING ANY SIGNS OF STRONG VERTICAL DEVELOPMENT.

THE MAIN QUESTION FOR TONIGHT IS WHETHER ANY CONVECTION WILL DEVELOP
ACROSS THE NORTH COUNTRY. THE REMNANTS OF THE MORNING MCS HAVE ALL
BUT DIED OUT...BUT MORE THUNDERSTORMS ARE DEVELOPING JUST NORTH OF
LAKE HURON IN THE VICINITY OF THE STATIONARY FRONT THAT STRETCHES
ACROSS SOUTHERN SOUTHERN. THE ETA SUGGEST THAT ANOTHER WEAK UPPER
LEVEL SHORT WAVE WILL RIDE ACROSS THE UPPER LEVEL RIDGE AND CROSS THE
NORTHERN PART OF THE STATE TONIGHT. BUT I THINK MOST OF THE
CONVECTION WILL STAY FOCUSED ALONG THE STATIONARY FRONT. THEREFORE I
WILL NOT MENTION AND PCPN FOR JEFFERSON AND LEWIS COUNTIES AT THIS
TIME.

ON TUESDAY...A SIGNIFICANT  CHANGE WILL BEGIN TO TAKE PLACE IN THE
UPPER LEVEL FLOW...SIGNIFYING THE END OF OUR RECENT HOT AND HUMID
SPELL. AS THE EASTERN UPPER LEVEL RIDGE DRIFTS INTO THE WESTERN PART
OF THE COUNTRY...IT WILL BE REPLACED BY A TROUGH THAT WILL SET UP
JUST SOUTHEAST OF JAMES BAY BY 12Z WEDNESDAY. THE FALLING HEIGHTS IN
THE EAST WILL ALLOW A COLD FRONT TO CROSS WESTERN NEW YORK LATE
TUESDAY AFTERNOON AND THE REST OF THE FA DURING THE EVENING.

THE BEST UPPER LEVEL SUPPORT IS FORECAST TO REMAIN NORTH OF THE STATE
ON TUESDAY...BUT A FEW THUNDERSTORMS WILL DEVELOP IN THE THE VERY
MOIST AND UNSTABLE AIR AHEAD OF THE FRONT. THE BRISK WEST TO
SOUTHWEST FLOW AHEAD OF THE COLD FRONT WILL ONCE AGAIN PRODUCE A MORE
STABLE SHADOW ZONE DOWNWIND OF BOTH LAKES. THEREFORE I WILL INDICATE
SLIGHTLY LOWER POPS EAST OF BUFFALO AND WATERTOWN TUESDAY AFTERNOON.

THE NGM AND AVN BRING THE FRONT THRU A LITTLE QUICKER THAN THE
ETA...BUT ALL THE MODELS SUGGEST THAT THE PCPN SHOULD BE ENDING
TUESDAY EVENING...FOLLOWED BY CLEARING CONDITIONS TUESDAY NIGHT.

THE REAL CHANGE WILL BE FELT ON WEDNESDAY WHEN MUCH DRIER AIR FILTERS
IN BEHIND THE COLD FRONT. MOS GUIDANCE INDICATES DEWPOINTS IN THE
LOWER 50S BY WEDNESDAY AFTERNOON. THIS WILL BE A VERY REFRESHING
CHANGE FROM THIS AFTERNOON/S READINGS IN THE LOWER TO MID 70S.

.BUF...NONE.

TJP