Area Forecast Discussion
Issued by NWS Burlington, VT

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
019
FXUS61 KBTV 181901
AFDBTV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
301 PM EDT MON MAY 18 2015

.SYNOPSIS...
SOUTH WINDS WILL DEVELOP ACROSS THE REGION AHEAD OF A LOW
PRESSURE SYSTEM APPROACHING FROM THE WEST. TEMPERATURES WILL BE
QUITE WARM IN NORTHERN NEW YORK AND THE CHAMPLAIN VALLEY, WHILE
EASTERN VERMONT WILL FEEL THE EFFECTS OF COOLER AIR FROM THE GULF
OF MAINE. CHANCES FOR RAIN WILL INCREASE FROM WEST TO EAST LATE
TODAY AND OVERNIGHT AS THE LOW PRESSURE SYSTEM DRAWS NEAR. A COLD
FRONT ON TUESDAY WILL BRING MORE CHANCES FOR THUNDERSTORMS,
FOLLOWED BY COOLER TEMPERATURES FOR THE SECOND HALF OF THE WEEK.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 1251 PM EDT MONDAY...MAINLY JUST CHANGES TO REFLECT CURRENT
OBSERVATIONS THIS AFTERNOON. GOING FORECAST WAS ALREADY IN GOOD
SHAPE. PREVIOUS DISCUSSIONS FOLLOW.

MAIN CHANGE WITH THIS UPDATE WAS TO DELINEATE CLOUDS IN EASTERN
VERMONT ASSOCIATED WITH BACK DOOR COLD FRONT. SUNRISE HAS REVEALED
SOLID LOW OVERCAST ON VISIBLE SATELLITE OVER MUCH OF EASTERN
VERMONT. PREVIOUS FORECAST HAD GENERAL OUTLINE BUT WAY LOW ON
TOTAL SKY COVER IN THAT AREA. NO MODEL GUIDANCE IS PICKING UP ON
THE CLOUDS SO USED THE 30 PERCENT SKY COVER AREA AND BUMPED IT UP
TO OVERCAST THROUGH LATE MORNING, THEN TAPERED DOWN THROUGH EARLY
AFTERNOON. QUITE A BIT OF VARIABILITY IN TEMPERATURES TODAY WITH
SOUTH WINDS BRINGING WARM AIR TO NORTHERN NEW YORK AND CHAMPLAIN
VALLEY, WHILE BACK DOOR FRONT KEEPS EASTERN VERMONT COOLER WITH
MORE CLOUDS.

SURFACE HIGH PRESSURE CENTERED OVER MAINE WILL KEEP EASTERLY FLOW
OFF THE GULF OF MAINE ACROSS NH INTO EASTERN VERMONT. SURFACE OBS
SHOWING EXTENT OF MOIST MARINE LAYER EVIDENT IN LOW OVERCAST BELOW
1500 FT INTO EASTERN VT. ELSEWHERE NEARLY CALM WINDS AND HIGH THIN
CLOUDS WITH PATCHES OF LIGHT FOG. SOUTHERLY FLOW TO DEVELOP TODAY
IN CHAMPLAIN VALLEY AND NORTHERN NY IN ADVANCE OF APPROACHING
SURFACE LOW. UPPER RIDGE CRESTS OVER REGION DURING THE DAY AND
SHIFTS EAST BY THE END OF THE PERIOD ALLOWING FOR CHANCE FOR
SHOWERS IN ST. LAWRENCE COUNTY.

TEMPS IN ST. LAWRENCE VALLEY TO REACH THE MID 80S...WITH 70S
ELSEWHERE AND EASTERN VERMONT ONLY IN THE 60S. MARINE LAYER IS
SHALLOW AND DO NOT EXPECT IT TO BECOME BLOCKED BY THE GREEN
MOUNTAINS AND REMAIN IN EASTERN VT. SOUTHERLY FLOW UP THE
CHAMPLAIN VALLEY WILL ALSO KEEP ANY MARINE INVERSION MIXED OUT AS
WELL. WINDS TO INCREASE TO 15 TO 25 KNOTS.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
AS OF 415 AM EDT MONDAY...500 MB RIDGE SHIFTS EAST EARLY IN THE
PERIOD WITH INITIAL SHORTWAVE TROUGH PUSHING INTO THE RIDGE.
DEEPER UPPER LOW MOVING ACROSS THE GREAT LAKES TONIGHT AND WILL
SUPPRESS RIDGE TO THE EAST AND SOUTH LATER IN THIS PERIOD. BAND OF
SHOWERS WITH SOME THUNDER WILL MOVE WEST TO EAST MAINLY OVERNIGHT
TONIGHT ALONG THE INITIAL SHORTWAVE TROUGH, WITH LIKELY POPS
TRANSLATING WEST TO EAST. SOUTHERLY FLOW WILL POOL VERY MOIST AIR
WITH PRECIPITABLE WATER OVER 1.5 INCHES BASED ON NAM BUFKIT PLOT,
WHICH GETS US ABOVE THE 90TH PERCENTILE FOR THE DAY. BRIEF HEAVY
DOWNPOURS ARE POSSIBLE, BUT THE GOOD NEWS IS RAIN WILL BE MOVING
THROUGH RELATIVELY QUICKLY AND HYDRO ISSUES ARE NOT A CONCERN.

FOR TUESDAY THE COLD FRONT MAKES ITS PUSH THROUGH, CROSSING
NORTHERN NEW YORK IN THE MORNING, CHAMPLAIN VALLEY MIDDAY, AND
VERMONT IN THE AFTERNOON. HIGH RESOLUTION MODELS NOT INDICATING
MUCH PRECIP WITH THE FRONT IN THE MORNING AS CAPE DOES NOT YET
BUILD, BUT BETTER CHANCES FOR RAIN SHOWERS AND SOME THUNDER FROM
MIDDAY ONWARD COINCIDING WITH SURFACE HEATING. TEMPERATURES
TUESDAY STILL WARM IN THE 70S. AFTER THE FRONT PASSES TEMPERATURES
QUITE A BIT COOLER TUESDAY NIGHT, WITH FROST A POSSIBILITY IN THE
ADIRONDACKS. LOW CHANCE POPS CONTINUE IN THE HIGHER TERRAIN
THROUGH WEDNESDAY. TRAILING 500 MB TROUGH PASSES THROUGH THE DAY
ON WEDNESDAY, AND WEST TO NORTHWEST UPSLOPE FLOW COMBINED WITH
DESTABILIZATION OF COLD POOL ALOFT AND RESIDUAL LOW LEVEL MOISTURE
WILL GENERATE SCATTERED TERRAIN DRIVEN SHOWERS. TEMPS WEDNESDAY IN
THE 50S AND 60S.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 301 PM EDT MONDAY...A PERUSAL OF THIS MORNING`S GLOBAL
MODEL OUTPUT CONTINUES TO SUGGEST ABOVE AVERAGE AGREEMENT ON THE
OVERALL WEATHER PATTERN DURING THE THURSDAY THROUGH MONDAY TIME
FRAME. THUS BY AND LARGE A PERSISTENCE FORECAST WILL BE OFFERED.
THE GENERAL PATTERN WILL FEATURE SUBSTANTIAL EASTERN NORTH PACIFIC
BLOCKING WHICH WILL TEND TO BE REINFORCED BY INFUSED ENERGY FROM
ONCE WEST PAC SUPER TYPHOON NOUL. THIS WILL IN TURN ALLOW A
SUPPRESSED POLAR JET AND BROAD-SCALE UPPER TROUGHING TO REMAIN
INTACT TO ITS EAST ACROSS THE NORTHERN GREAT LAKES INTO THE
NORTHEASTERN CONUS WITH SEASONABLY COOL AND MAINLY DRY WEATHER
EXPECTED. THE BEST SHOT FOR A FEW/SCATTERED SHOWERS WILL OCCUR ON
FRIDAY WITH PASSAGE OF A FAIRLY DISTINCT SURFACE TROUGH, OTHERWISE
DRY CONDITIONS ARE EXPECTED THROUGH SUNDAY WITH MEAN HIGH PRESSURE
DOMINATING IN THE LOWER LEVELS. OF SOME CONCERN WILL BE CHILLY
OVERNIGHT LOW TEMPERATURES, WHICH WILL AVERAGE SOME 5-10 DEGREES
BELOW NORMAL THROUGH SATURDAY MORNING. THUS PATCHY FROST WILL BE
QUITE POSSIBLE IN MANY AREAS OUTSIDE THE IMMEDIATE CHAMPLAIN
VALLEY, ESPECIALLY ON FRIDAY NIGHT/SATURDAY MORNING WHEN CORE OF
THE SURFACE HIGH DRIFTS OVERHEAD.

BY SUNDAY ONWARD UPPER TROUGHING SHOULD BEGIN TO ABATE WITH A
MODERATION IN TEMPERATURES EXPECTED. SOME MODEL DISPARITY BY NEXT
MONDAY (MEMORIAL DAY) WITH THIS MORNING`S OPERATIONAL RUNS NOW
SUGGESTING THAT RESIDUAL NORTHWESTERLY FLOW AT MID-LEVELS MAY
SUPPRESS INITIAL RETURN OF WARM/MOIST ADVECTION AND ASSOCIATED
PRECIPITATION OFF TO OUR SOUTH AND WEST. FOR NOW WILL MAINTAIN
SLIGHT TO LOW CHANCE POPS FOR SHOWERS OUT OF RESPECT FOR THE
ACCOMPANYING ENSEMBLE MEANS.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
THROUGH 18Z TUESDAY...VFR, WITH A PERIOD OF MVFR POSSIBLE
OVERNIGHT INTO TUESDAY MORNING AS SCT SHOWERS/THUNDER MOVE THROUGH
THE REGION. SCT SHOWERS/THUNDER DEVELOPING ACROSS CENTRAL/WRN NY
STATE THIS AFTERNOON WILL PROGRESS NORTH AND EAST INTO THIS
EVENING, AND ACROSS MOST TERMINALS OVERNIGHT. BEST CHANCE OF
SHOWERS/THUNDER TO OCCUR AT KSLK/KPBG/KBTV 22-03Z, THEN MAINLY
AREAS OF SHOWERS FROM 03-12Z AT MOST TERMINALS WITH PATCHY BR AND
MVFR CIGS OVERNIGHT, MVFR BEING MOST LIKELY AT KMPV/KSLK. WINDS
SOUTH TO SOUTHWESTERLY AND GUSTY THROUGH 00Z (SOUTHEAST AT
KPBG/KRUT) BEFORE ABATING OVERNIGHT INTO TUESDAY.

OUTLOOK 18Z TUESDAY THROUGH SATURDAY...

18Z TUESDAY THROUGH 00Z WEDNESDAY...BKN/OVC VFR/MVFR WITH
SCATTERED SHOWERS/THUNDER, MAINLY KPBG/KBTV EASTWARD. BRIEF IFR
POSSIBLE IN HEAVIER DOWNPOURS.

00Z WEDNESDAY ONWARD...MAINLY VFR WITH HIGH PRESSURE.

&&

.MARINE...
AS OF 240 PM EDT MONDAY...LOW PRESSURE SYSTEM APPROACHING FROM
THE WEST IS BRINGING SOUTHERLY WINDS DURING THE AFTERNOON AND
EVENING. SOUTH WINDS ARE NEAR LAKE WIND ADVISORY NOW AT 10-25
KNOTS. SOUTH WINDS 15-25 KNOTS TO CONTINUE OVERNIGHT AND INTO
TUESDAY, UNTIL THE COLD FRONT PASSES AROUND MID DAY TUESDAY AND
WIND SHIFTS TO WEST. WINDS COULD INCREASE TO ADVISORY LEVEL AGAIN
ON WEDNESDAY AFTERNOON AT 15-25 KNOTS. WAVES OF 1-3 FEET ARE
EXPECTED FOR THIS AFTERNOON AND TONIGHT.

&&

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

&&

$$
SYNOPSIS...HANSON
NEAR TERM...NEILES/HANSON
SHORT TERM...HANSON
LONG TERM...JMG
AVIATION...JMG
MARINE...MV



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.