Area Forecast Discussion Issued by NWS Burlington, VT
000
FXUS61 KBTV 171528
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
1128 AM EDT MON JUN 17 2013
.SYNOPSIS...
A COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS
MONDAY AND MONDAY NIGHT...SOME THUNDERSTORMS MAY CONTAIN STRONG
GUSTY WINDS AND SMALL HAIL. SHOWERS WILL LINGER INTO
TUESDAY...MAINLY FOR SOUTHERN VERMONT. SURFACE HIGH PRESSURE WILL
THEN BUILD INTO THE NORTH COUNTRY BRINGING DRY WEATHER FOR
TUESDAY NIGHT THROUGH THE END OF THE WEEK. TEMPERATURES WILL
GENERALLY SEE DAYTIME MAXIMUMS IN THE MID 60S TO 70S AND
NIGHTTIME MINIMUMS IN THE 40S AND 50S.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 1031 AM EDT MONDAY...ADJUSTED TEMP/DWPT AND SKY GRIDS BASED
ON OBS. MOST CLEARING TO OUR SOUTH WHERE BEST INSTABILITY WILL BE
FOR THIS AFTN.
MODELS SHOWING 2 DISTINCT ROUNDS OF SHOWERS...ONE EARLIER IN THE
DAY/EARLY AFTN WITH THE PREFRONTAL TROUGH...WITH SW WINDS SHIFTING
MORE W BEHIND IT...THEN ANOTHER ROUND OF SHOWERS WITH THE FRONT
LATE IN THE DAY INTO TONIGHT...FURTHER SHIFTING WINDS TO THE NW/N.
AFOREMENTIONED CLEARING SKIES AHEAD OF THE APPROACHING COLD FRONT
AND UPPER LEVEL TROUGH WILL HELP INCREASE INSTABILITY TODAY.
LIMITING FACTOR OF MIXED LAYER CAPE VALUES OF 400+J/KG...BUT SOME
AREAS OVER VT NEARING 800-900J/KG COULD BE OVERDONE BY MODEL
GUIDANCE. BEST INSTABILITY LOOKS TO BE SOUTH OF THE AREA. OVER THE
NORTH COUNTRY AND AREAS SOUTH...EXPECTING LIFTED INDICES OF -4C TO
-6C AND WIND SHEAR...0-1KM AT 15-25KTS AND 0-6KM AT 40-50KTS. THIS
SHEAR COMBINED WITH BUFKIT FCST STORM MOTION OF 30-40 KTS COULD
RESULT IN A FEW STRONG THUNDERSTORMS ALONG AND AHEAD OF A PRE-
FRONTAL TROUGH IN THE LATE MORNING/EARLY AFTERNOON HOURS. THESE
STRONG STORMS COULD PRODUCE SMALL HAIL AND GUSTY WINDS...HOWEVER
NOT ANTICIPATING MUCH IN THE WAY OF SEVERE THUNDERSTORMS WITH THIS
SYSTEM. NAM AND GFS SEEM TO BE LACKING IN UPPER JET
DYNAMICS/SUPPORT...WITH 250MB JET STREAK ONLY SHOWING UP AROUND
WRN NY/PA AROUND 06S...FAR BEHIND THE FRONT. THE MAIN COLD FRONT
WILL BE WEAK AS IT PUSHES INTO THE REGION LATE IN THE DAY AND INTO
THE EVENING.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH WEDNESDAY/...
AS OF 448 AM EDT MONDAY...MONDAY NIGHT WILL SEE CONTINUED SCTD
SHOWERS AND TS AS FRONT GRADUALLY PRESSES EASTWARD AND ASSOCIATED
UPPER LOW APPROACHES FROM THE NW. MIN TEMPS WILL BE IN THE 50S
AGAIN WITH MOSTLY CLOUDY CONDITIONS. AS THE UPPER TROUGH MOVES
ACROSS THE REGION TUESDAY...SOME SCTD SHOWERS WILL DEVELOP
THROUGHOUT THE DAY. TEMPS WILL BE A LITTLE COOLER WITH NW FLOW
BRINGING IN CAA...WITH MAXES IN THE 60S TO L70S.
TUESDAY NIGHT...UPPER TROUGH WILL CONTINUE ITS EWD PROGRESSION
WITH HIGH PRESSURE BUILDING IN AT THE SFC. ANY SHOWERS WILL
END...WITH GENERALLY CLEARING SKIES. MIN TEMPS WILL BE IN THE 40S
TO NEAR 50. HIGH PRESSURE CONTINUES TO DOMINATE ON WEDNESDAY WITH
MOSTLY CLEAR SKIES...AND DRY CONDITIONS. MAX TEMPS WILL BE IN THE
L60S-L70S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 405 AM EDT MONDAY...UPPER LEVEL PATTERN IN THE EXTENDED IS
RATHER CONSISTENT WITH NORTHWEST FLOW ALOFT ESSENTIALLY REMAINING
OVER THE AREA RIGHT THROUGH THE PERIOD. EXPECTING DRY WEATHER
WEDNESDAY NIGHT THROUGH FRIDAY WITH A SLOW WARMING TREND. HIGH
TEMPERATURES SHOULD BE AT OR SLIGHTLY ABOVE NORMAL BY THE END OF
THE WEEK...THEN REMAIN SLIGHTLY ABOVE NORMAL FOR THE WEEKEND
DESPITE A BIT MORE CLOUD COVER. LOOKS LIKE THE FLOW ALOFT BECOMES
MORE WEST TO NORTHWEST OVER THE WEEKEND AND THIS COULD
POTENTIALLY ALLOW ANY MESOSCALE CONVECTIVE SYSTEMS TO MOVE INTO
OUR AREA. THUS GOING FORECAST OF A SLIGHT CHANCE TO LOW CHANCE
PRECIPITATION PROBABILITIES SATURDAY AND SUNDAY.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
THROUGH 12Z TUESDAY...CEILINGS AND VISIBILITIES HAVE IMPROVED BACK
INTO THE MVFR AND VFR CATEGORIES...WHICH IS WHERE THEY WILL RESIDE
THROUGH ABOUT 00Z. WATCH FOR A COLD FRONT TO SAG SOUTH OUT OF
CANADA AND MOVE ACROSS THE AREA BETWEEN 17Z AND 00Z. EXPECT
SHOWERS TO DEVELOP AHEAD OF THIS FRONT AND MOVE QUICKLY FROM WEST
TO EAST DURING THIS TIME FRAME. HAVE INCLUDED VARIABLE WIND GUSTS
IN THE 20 TO 30 KNOT RANGE WITH ANY OF THE SHOWERS OR
THUNDERSTORMS. MVFR CEILINGS AND VISIBILITIES WILL BE THE RULE
WITH ANY OF THE SHOWERS OR STORMS. FRONT MOVES SOUTH OF THE AREA
BY 00Z AND PRECIPITATION WILL COME TO AN END. VISIBILITIES WILL BE
IN THE VFR CATEGORY WITH CEILINGS RANGING LINGERING EARLY IN THE
MVFR CATEGORY...BUT IMPROVING INTO THE VFR CATEGORY AFTER 02Z AND
REMAINING THERE THROUGH THE REMAINDER OF THE PERIOD. WINDS WILL BE
MORE NORTHWEST ONCE THE FRONT PASSES AFTER 00Z.
OUTLOOK 12Z TUESDAY THROUGH THURSDAY...
12Z TUESDAY THROUGH 12Z FRIDAY...MAINLY VFR AS HIGH PRESSURE BUILDS
INTO THE REGION. PATCHY LATE NIGHT/EARLY MORNING FOG POSSIBLE
06-12Z EACH DAY...WITH MOST POTENTIAL AT KSLK/KMPV.
12Z FRIDAY ONWARD...GENERALLY VFR. WEAK FRONT SAGGING SOUTHWARD
TOWARD INTL BORDER MAY SPARK A FEW/WIDELY SCT SHOWERS/STORMS
AFTER 18Z AT NORTHERN TERMINALS.
&&
.MARINE...
SCATTERED TO NUMEROUS SHOWERS AND A FEW THUNDERSTORMS ARE EXPECTED
ACROSS THE LAKE CHAMPLAIN WATERS THIS AFTERNOON AND INTO THIS
EVENING. A FEW OF THE STORMS MAY BECOME LOCALLY STRONG WITH GUSTY
WINDS AND SMALL HAIL POSSIBLE THIS AFTERNOON. THE PRIMARY THREAT
OF ANY STRONGER STORMS SHOULD OCCUR ACROSS THE SOUTHERN HALF OF
THE LAKE FROM BURLINGTON SOUTHWARD. WINDS ARE ALREADY VEERING TO
WEST/SOUTHWESTERLY AND EXPECTED THIS GENERAL TREND TO CONTINUE
INTO THE AFTERNOON AND EVENING HOURS IN THE 5 TO 15 KNOT RANGE.
WAVES MAINLY AROUND 1 FOOT...THOUGH LOCALLY HIGHER TO NEAR 2 FEET
WITH A LIGHT CHOP ALONG THE EASTERN SHORE AND IN BAYS WITH A
WESTERLY EXPOSURE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KGM/MUCCILLI
NEAR TERM...KGM/NEILES
SHORT TERM...KGM
LONG TERM...EVENSON
AVIATION...EVENSON/JMG
MARINE...JMG