Severe Thunderstorm Warning 3, NWS Burlington, VT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
230 PM EDT TUE MAY 9 2000

CRNT: WRM FNTL BNDRY WITH GOOD MOIST ADVECTION AND SFC CONVERGENCE
LYING ACRS A KOGS-KBTV-KMVL-K1V4 LINE. MOST RECENT ACTVTY FIRE UP
ALG BNDRY AND EXITING VORT MAX AT 17Z...BUT MVD ACRS MORE STABLE
VCNTY AND WEAKER THAN THIS MRNG/S ACTVTY.

THREE FCST PRBLMS FOR THIS PKG.
1) ISOLD SVR WX THREAT FOR SRN ZONES?!
2) WHERE...WHEN...DURATION OF ACTVTY THIS EVENING/TNGT (MAINLY FOR
FLD CONCERNS).
3) PSBL MORE WIDESPREAD EVENT WED AFTN WITH S/W AND FNT.

PRBLM #1: LTST SWOMCD ADDRESSES THIS PRBLM. PRETTY MUCH UNI-
DIRECTIONAL FLOW OF 40 KTS AT H8 AND 60 KTS AT H5 WITH GRTST
INSTABILITY WELL SOUTH OF WRM FNTL BNDRY. VSB SAT PIXS SHW TWO AREAS
OF IMMEDIATE CONCERN CENT NY AND ERN ONTARIO. THIS IS WELL AHD OF
APPRCHG VORT LOBE XPCTD TO SLICE ACRS NY BY 00Z. ACTUALLY...THIS LOBE
IS ASSOC WITH ERLR TSTM ACTVTY ACRS INDIANA THIS MRNG AND WL LKLY
FOLLOW THE HISTORY OF PRODUCING MORE ACTVTY LATE TDY/TNGT.

PRBLM #2: VORT LOBE FM INDIANA ACTVTY LKLY FOLLOWING CD FNTL
BNDRY AND THEN OVERRIDE RDG AND MV ALG WRM FNTL BNDRY AS PAST
EPISODES. THIS CUD FIRE UP MORE NOCTURNAL CONVECTION WITH PW/S OF
1-1.5 AND TVL ALG WRM FNTL BNDRY OVRNGT THAT SHLD LIE ACRS SAME AREA
THAT WITNESSED 1.5-3 INCHES OF RAIN. THE CONCERN IS ERLY CONVECTION
IN CENT NY AS WELL AS LESS THAN FVBRL JET IN QUESTION OF A REPEAT
PERFORMANCE. MDLS INDICATE CONVECTION FURTHER SOUTH AND NOT
NECESSARILY OVERRIDING BNDRY AS LAST NGT. IN FACT...WTR
VPR/VSB SHW BNDRY THAT MDLS KEY ON SETTING UP ACRS CENT NY.
ALSO... AMPLIFYING TROF PRODUCING S/W RDG AHD THAT MAY SQUELCH ACTVTY
FURTHER S AS WELL.

ATTM...LEANING AGAINST FFA BUT AM CONCERNED ABT PRVS HISTORY OF
VORT MAX. WL ISSUE FFSBTV ABT HIGH STREAMS AND PSBL THREAT TO ALLOW
ROOM FOR EVENING SHIFT IF NECESSARY. STAY TUNED!!!

PRBLM #3: INITIALLY WRM FNTL BNDRY STAYS STNRY OR PSBLY RETROGRADES
AS VEERING WND ALLOWS AGEO FLOW TO DROP BKDOOR. HWVR...AS SYNOPTIC
SYSTEM APPROACHES...SUNSHINE SOUTH OF BNDRY AND INCREASING SSW WND
DVLPS WED...WUD XPCT FNT TO MV N INTO MUCH OF FA TMRW.

FVRBL JET DYNAMICS WITH H5 S/W AND APPRCHG SFC LOW/FNT. SHEAR IS
MNLY UNIDIRECTIONAL ALTHOUGH SOME DIRECTIONAL SHEAR NR SFC LOW
AND WRM FNTL BNDRY. ACTVTY SHLD BE MUCH MORE WIDESPREAD WITH PSBL
N-S SQUALL LINE MVG QUICKLY. HVY RAIN BUT UNLIKELY TRAINING.

WORKS OUT BY 3 PM. ZONES BY 330 PM.

.BTV...NONE.

SLW

NYZ026>031-034-035-VTZ001>012-092200-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BURLINGTON VT
1210 PM EDT TUE MAY 9 2000

...MORE THUNDERSTORMS LATE THIS AFTERNOON AND TONIGHT COULD PRODUCE
ISOLATED SEVERE WEATHER IN THE NORTH COUNTRY...

AT NOON...A FRONTAL BOUNDARY LIES ACROSS THE SAINT LAWRENCE RIVER
VALLEY AND THE NORTHERN THIRD OF VERMONT.

SOUTH AND ALONG OF THIS LINE...PARTLY SUNNY SKIES WITH WARM
TEMPERATURES AND HUMIDITY WILL BE IDEAL OF DEVELOPMENT OF
THUNDERSTORMS LATER THIS AFTERNOON INTO TONIGHT. ISOLATED SEVERE
WEATHER IN THE FORM OF STRONG WINDS AND LARGE HAIL ARE POSSIBLE ALONG
WITH TORRENTIAL RAINS AND FREQUENT...DANGEROUS LIGHTNING.

NORTH OF THIS LINE...SHOWERS AND THUNDERSTORMS HAVE BEEN NUMEROUS
THROUGH THIS MORNING WITH TORRENTIAL RAINS AND FREQUENT LIGHTNING
CAUSING SCATTERED POWER OUTAGES. HEAVY RAINFALL OF 1 TO 2 INCHES
WITH LOCALLY HIGHER AMOUNTS HAVE CAUSED PONDING OF WATER ON ROADWAYS
AND RAPID RISES OF AREA STREAMS BUT NO REPORTS OF FLOODING.
ADDITIONAL THUNDERSTORMS WITH HEAVY RAIN...ESPECIALLY TONIGHT COULD
CAUSE ISOLATED FLOOD PROBLEMS.

STAY TUNED TO NOAA WEATHER RADIO...COMMERCIAL TELEVISION AND
RADIO...OR YOUR CABLE TELEVISION PROVIDER FOR LATER STATEMENTS
CONCERNING THIS POTENTIALLY DANGEROUS SEVERE WEATHER THREAT.

&&

WHITTIER