000
FXUS61 KBTV 291718
AFDBTV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
118 PM EDT TUE JUL 29 2014

.SYNOPSIS...
TODAY WILL BE PARTLY SUNNY WITH TEMPERATURES SLIGHTLY BELOW
NORMAL WITH A NORTHWEST FLOW OF AIR FROM CANADA. A SHOWER OR
ISOLATED THUNDERSTORM WILL BE POSSIBLE BOTH WEDNESDAY AND THURSDAY
AFTERNOONS WITH LOW PRESSURE OVER EASTERN CANADA. A RETURN TO MORE
NORMAL SUMMER WEATHER IS EXPECTED THIS WEEKEND WITH A SLIGHT
CHANCE OF AN AFTERNOON OR EVENING SHOWER OR THUNDERSTORM.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1245 PM EDT TUESDAY...AFTERNOON FORECAST REMAINS IN GREAT
SHAPE WITH CONTINUED NORTHWEST FLOW PROVIDING SEASONABLY COOL
TEMPERATURES AND PARTY CLOUDY/SUNNY SKIES. CURRENT TEMPS ARE
GENERALLY RANGING FROM THE LOW 60S TO LOW 70S AND LIKELY WILL ONLY
RISE A COUPLE MORE DEGREES OVER THE NEXT FEW HOURS. CLOUD COVER WILL
REMAIN RATHER STEADY BEFORE SLOWLY BEGINNING TO DISSIPATE TOWARDS
SUNSET.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 452 AM EDT TUESDAY...

CYCLONIC FLOW ALOFT CONTINUES THROUGH THIS PERIOD WITH THE BEST
CHANCE OF SHOWERS AND THUNDERSTORMS ON THURSDAY AS FAIRLY POTENT
SHORT WAVE AND COLD POCKET ALOFT (-18 TO -20C AT 500 MB) ROTATES
THROUGH NORTHERN NEW YORK AND NEW ENGLAND.

OTHER THAN SOME DISSIPATING DIURNAL CLOUDS THIS EVENING EXPECTING
SOME MOSTLY CLEAR SKIES TONIGHT WITH LOW TEMPS IN THE MID 40S IN
THE USUAL COLD SPOTS TO MID TO UPPER 50S NEAR LAKE CHAMPLAIN. ALSO
EXPECTING SOME PATCHY DENSE RIVER VALLEY FOG AFTER MIDNIGHT UNTIL
ABOUT 8 A.M. IN THE CLIMATOLOGICALLY FAVORED FOG PRONE LOCATIONS.

ON WED LITTLE CHANGE IN THE SYNOPTIC SCALE PATTERN IS
EXPECTED...SOME WEAK INSTABILITY ESPECIALLY ST. LAWRENCE VALLEY
WITH SLIGHTLY COOLER TEMPS ALOFT. RESULTING CAPE FROM THE THE
MODELS AVG ABOUT 300 J/KG AND SUPPORTS THE IDEA OF A CHANCE OF SHOWERS OR
AN ISOLATED RUMBLE OF THUNDER AS SOME OF THE CONVECTION ALLOWING
MODELS SHOWING CAPE AS HIGH AS 1000 J/KG AT KMSS. 850 TEMPS CHANGE
VERY LITTLE PERHAPS A DEGREE WARMER THAN TODAY NEAR 10C WITH HIGHS
MAINLY IN THE 70S.

AGAIN PARTLY CLOUDY SKIES WED NIGHT AND SOME PATCHY FOG POSSIBLE.

THURSDAY WILL FEATURE THE STRONGER SUPPORT ALOFT WITH DIFF VORT
ADVECTION AND COOLING ALOFT. ARW MEMBERS OF THE SREF ALL SHOWING
CAPE VALUES UP TO 750 J/KG WITH OTHER MEMBERS LESS. WITH FURTHER
COOLING ALOFT ON THURSDAY AND A LITTLE MORE HEATING COULD SEE SOME
CAPE VALUES OVER 1000 J/KG AS THE ECMWF INDICATES OVER VT. FURTHER
WEST IT MAY BE THE TIME OF THE SHORT WAVE IS A BIT TOO EARLY WITH
MOVER CLOUDS TO PREVENT SIGNIFICANT HEATING. HIGHS AGAIN IN THE
70S.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 452 AM EDT TUESDAY...

A FALL/WINTER/EARLY SPRING LOOK TO THE UPPER LEVEL PATTERN ACROSS
NOAM...DOMINATED BY A SLOW-MOVING/RETROGRADING UPPER LOW PARKED OVER
THE JAMES BAY REGION AND A BUILDING ATLANTIC RIDGE ALOFT.

THE PROXIMITY OF TROF AXIS ALOFT AND SURFACE WITH DAYTIME HEATING
WILL ACCOUNT FOR CHC SHRA/TSRA ON THE WEEKEND BUT HOPEFULLY
REMAINING DRY ON FRIDAY OR JUST ISOLATED IN NATURE.

UPPER LOW FINALLY WEAKENS AND SHIFTS EASTWARD INTO THE GULF OF SAINT
LAWRENCE SUNDAY WITH A WEAK RIDGE DEVELOPING ALOFT SUNDAY NIGHT INTO
MONDAY WITH SUNNIER/DRIER WEATHER EXPECTED.

TEMPERATURES WILL REMAIN AT SEASONABLE LEVELS THROUGH THE STRETCH
WITH 70S/L80S DURING THE DAY AND PRIMARILY 50S/L60S AT NIGHT WITH
SFC DEWPOINTS CREEPING BACK INTO U50S/L60S.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
THROUGH 18Z WEDNESDAY...VFR CONDITIONS WL PREVAIL AT ALL TAF SITES
THRU THIS EVENING. AVIATION CHALLENGE WL BE AREAL COVERAGE OF FOG
AT SLK/MPV AND ASSOCIATED LIFR CONDITIONS. THINKING DIURNALLY
DRIVEN CUMULUS CLOUDS WL DISSIPATE WITH THE LOSS OF SFC HEATING
THIS EVENING...WITH AREAS OF FOG DEVELOP AT SLK/MPV BY 06Z
TONIGHT. GUIDANCE SUGGESTS THESE AREAS WL DROP BLW THEIR CROSS
OVER TEMPS...WITH CLR SKIES AND LIGHT WINDS...COMBINED WITH RECENT
RAINFALL WL RESULT IN FOG. HAVE MENTION VIS 1/2SM WITH CIGS OVC AT
100 FEET AT BOTH MPV/SLK. THINKING SOME WINOOSKI RIVER VALLEY FOG
COULD IMPACT BTV...ESPECIALLY NORTHERN AND EASTERN SIDE OF THE
AIRPORT...ESPECIALLY IF A LIGHT DRAINAGE FLW CAN DEVELOP...PER
LOCAL BTV SOLUTION. OTHERWISE...WINDS OF 15 TO 20 KNTS AT 200 FEET
AGL AND TRRN DRIVEN WINDS AT RUTLAND OF 3 TO 7 KNOTS WL LIMIT FOG
POTENTIAL. OTHERWISE...FOG LIFTS BTWN 12-13Z ON WEDS WITH VFR
CONDITIONS.

OUTLOOK 18Z WEDNESDAY THROUGH SATURDAY...
SCATTERED SHOWERS AND THUNDERSTORMS WL BE POSSIBLE WEDS AND THURS
AFTNS WITH LOCALIZED MVFR CONDITIONS IN THE HEAVIER
SHOWERS/STORMS. IN ADDITION...BRIEF GUSTY WINDS WL BE POSSIBLE
WITH VIS BTWN 3-5SM IN ANY SHOWER ACTIVITY. CLOUDS AND WINDS
SHOULD LIMIT FOG/BR POTENTIAL...BUT LOCATIONS THAT RECEIVE RAINFALL
DURING THE DAYTIME HAVE THE POTENTIAL FOR IFR CONDITIONS IN FOG AT
NIGHT. SFC HIGH PRES WITH MAINLY VFR CONDITIONS WL PREVAIL FRIDAY
INTO SATURDAY.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.

&&

$$
SYNOPSIS...SISSON
NEAR TERM...LAHIFF
SHORT TERM...SISSON
LONG TERM...SLW
AVIATION...TABER