491  
FXUS61 KBTV 290627  
AFDBTV  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BURLINGTON VT  
227 AM EDT MON JUN 29 2026  
   
WHAT HAS CHANGED  
 
AS OF 226 AM EDT MONDAY...  
 
DANGEROUS HEAT AND HUMIDITY IS STILL ON TRACK FOR WEDNESDAY THROUGH  
AT LEAST THURSDAY, AND PERHAPS INTO FRIDAY. THE THREAT FOR SEVERE  
THUNDERSTORMS HAS INCREASED FOR TUESDAY NIGHT AND WEDNESDAY.  
 
 
   
KEY MESSAGES  
 
AS OF 226 AM EDT MONDAY...  
 
1. DANGEROUS HEAT AND HUMIDITY ARE EXPECTED FOR MID TO LATE  
WEEK. HEAT HEADLINES WILL LIKELY NEED TO BE ISSUED BY SUBSEQUENT  
SHIFTS.  
 
2. STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE TUESDAY AND  
WEDNESDAY.  
 
3. DANGEROUSLY HOT AND HUMID CONDITIONS WILL LINGER INTO THE  
HOLIDAY WEEKEND ALONG WITH DAILY CHANCES OF SHOWERS AND  
THUNDERSTORMS.  
 
 
   
DISCUSSION  
 
AS OF 226 AM EDT MONDAY...  
 
KEY MESSAGE 1: TODAY STARTS A GRADUAL WARMING TREND THAT WILL CONTINUE  
INTO THE LATTER HALF OF THE WEEK. HIGH PRESSURE WILL BUILD EASTWARD  
FROM THE OHIO RIVER VALLEY, WHILE A WARM FRONT LIFTS TOWARD AND  
EVENTUALLY ACROSS OUR REGION TUESDAY INTO WEDNESDAY. WHILE TODAY  
WILL REMAIN FAIRLY COMFORTABLE, HUMIDITY WILL INCREASE MARKEDLY AS  
THE FRONT MOVES THROUGH, MAKING FOR VERY MUGGY CONDITIONS BY LATE  
TUESDAY INTO TUESDAY NIGHT. GUIDANCE CONTINUES TO KEEP TUESDAY A  
TOUCH COLDER THAN PREVIOUS RUNS OWING TO CLOUD COVER AND  
PRECIPITATION CHANCES (MORE ON THAT BELOW), SO WHILE IT WILL BE HOT  
AND HUMID, EXPECT HEAT INDEX VALUES TO GENERALLY REMAIN AT OR BELOW  
90F. HEAT BUILDS ON WEDNESDAY, WITH 925MB TEMPERATURES APPROACHING  
26-28C, AND PERHAPS EVEN WARMER IF THE GFS HOLDS TRUE. AS SUCH, WE  
EXPECT THIS WILL BE THE FIRST DAY TO WARRANT HEAT HEADLINES,  
PARTICULARLY SINCE DEWPOINTS WILL BE 70F OR BETTER ACROSS MUCH OF THE  
REGION. HOWEVER, THERE'S STILL CONSIDERABLE SPREAD IN  
SHOWER/THUNDERSTORM TIMING/PLACEMENT/COVERAGE ON WEDNESDAY, WHICH  
COULD POTENTIALLY IMPACT HIGH TEMPERATURES. REGARDLESS, THE HEAT  
WILL CONTINUE INTO THURSDAY AND PERHAPS BEYOND, WITH DEWPOINTS  
REMAINING IN THE UPPER 60S TO LOW 70S. IF PRECIPITATION HOLDS OFF  
AND EVERYTHING COMES TOGETHER JUST RIGHT, HEAT INDEX VALUES OF 95 TO  
105 ARE VERY MUCH POSSIBLE BOTH WEDNESDAY AND THURSDAY. AND THERE  
WILL BE LITTLE RELIEF OVERNIGHT AS MUGGY CONDITIONS WILL KEEP LOWS  
CLOSE TO OR ABOVE 70F. GIVEN THAT THE CORE OF THE HEAT IS STILL 48+  
HOURS AWAY AND THERE'S SOME UNCERTAINTY HOW WEDNESDAY'S TEMPERATURES  
WILL PLAY OUT, HAVE OPTED TO NOT ISSUE ANY HEAT HEADLINES AT THIS  
TIME. HOWEVER, PLEASE USE THIS TIME TO PREPARE FOR POTENTIALLY  
DANGEROUS HEAT LATER THIS WEEK, AND FOLLOW FORECAST UPDATES CLOSELY.  
 
KEY MESSAGE 2: WE'LL REMAIN ON THE NORTHEASTERN PERIPHERY OF AN UPPER  
LEVEL WHICH WHICH WILL BE CENTERED NEAR/OVER THE OHIO RIVER VALLEY.  
MODEL GUIDANCE CONTINUES TO INDICATE THE POTENTIAL FOR SEVERAL  
SHORTWAVES/RIDGE ROLLERS TO RIDE OVER THE TOP OF THE RIDGE AND DOWN  
THROUGH THE NORTHWEST FLOW THAT WILL BE IN PLACE OVER NEW ENGLAND.  
AS THESE DISTURBANCES MOVE ALONG THE UPPER FLOW, WE ALSO LOOK TO BE  
INFLUENCED BY WAVES OF AN EML, EITHER RIGHT OVERHEAD OR MOVING JUST  
OFF TO OUR WEST. THIS WILL INCREASE INSTABILITY, EVEN INTO THE  
OVERNIGHT HOURS, THUS AIDING ANY NIGHT TIME CONVECTION. TIMING THESE  
SORTS OF RIDGE ROLLING SYSTEMS IS NOTORIOUSLY DIFFICULT, BUT AT THIS  
TIME, GUIDANCE SEEMS TO BE KEYING IN ONE MOVING THROUGH  
NORTHERN/WESTERN NEW ENGLAND AND NY SOMETIME LATER TUESDAY INTO  
TUESDAY NIGHT, WITH ANOTHER ONE POTENTIALLY FOLLOWING SOMETIME  
WEDNESDAY. IF CONVECTION MOVES IN DURING DAYLIGHT HOURS, SB CAPE  
WILL BE AMPLE, GENERALLY 500-1500+ J/KG FROM THE CHAMPLAIN VALLEY  
WESTWARD ON TUESDAY. THIS WOULD BECOME MORE WIDESPREAD AND INCREASE  
ON WEDNESDAY, WITH SB CAPE AN IMPRESSIVE 1000-2000+ J/KG ACROSS MUCH  
OF THE AREA (NOTE BOTH THE NAM AND GFS HAVE VALUES AS HIGH AS 3000  
J/KG, THOUGH PLACEMENT DIFFERS BETWEEN THE MODELS). SHEAR BOTH DAYS  
WILL BE A RESPECTABLE 35-50 KT. HENCE, IF CONVECTION DOES DEVELOP  
DURING THE DAYLIGHT HOURS, STRONG TO SEVERE THUNDERSTORMS CAPABLE OF  
LARGE HAIL, DAMAGING WINDS, ESPECIALLY IN ANY SUPERCELLS. ANY  
OVERNIGHT STORMS WOULD BE ELEVATED BUT STILL CAPABLE OF SOME SMALL  
HAIL. AND ANY STORMS WOULD BE CAPABLE OF PRODUCING VERY HEAVY  
RAINFALL, WITH PWATS 1.5 TO 2+ INCHES AND WARM CLOUD DEPTHS 10-12+  
KFT. THIS THINKING IS REINFORCED BY BOTH SPC, WHICH HAS US INCLUDED  
IN A MARGINAL RISK (LEVEL 1 OF 5) FOR TUESDAY AND TUESDAY NIGHT,  
WHILE WPC LIKEWISE HAS A MARGINAL RISK (LEVEL 1 OF 4) OF EXCESSIVE  
RAINFALL OVER OUR REGION. THIS IS A COMPLEX SCENARIO AND THERE'S  
STILL PLENTY OF UNCERTAINTY, SO PLEASE STAY TUNED FOR FUTURE  
FORECAST UPDATES, ESPECIALLY IF YOU HAVE OUTDOOR PLANS.  
 
KEY MESSAGE 3: PROLONGED HEAT WILL LIKELY BE ONGOING INTO THE END OF  
THE WEEK WITH AMPLE HUMIDITY, EVEN AS TEMPERATURES TREND LESS  
EXTREME. WHILE WE SHOW ANOTHER DAY OF HIGH HEAT INDEX VALUES ON  
FRIDAY WITH PEAK VALUES WELL INTO THE 90S AT ELEVATIONS BELOW 1000  
FEET, THE POTENTIAL FOR A MESOSCALE CONVECTIVE SYSTEM AND ITS EFFECT  
ON TEMPERATURES MAKES THIS FORECAST SOMEWHAT UNCERTAIN. FURTHERMORE,  
SOME GUIDANCE IS MORE AMPLIFIED WITH THE RIDGE CENTERED TO OUR  
SOUTHWEST, WHICH ALLOW FOR MORE ANOMALOUS LOW LEVEL TEMPERATURES TO  
REMAIN IN OUR AREA. THE MEAN 925 MILLIBAR TEMPERATURES RANGE FROM  
MERELY VERY WARM (CLOSE TO 20 CELSIUS) IN THE COOLER SCENARIO TO HOT  
(CLOSE TO 26 CELSIUS) IN THE HOTTER SCENARIO, TRANSLATING TO HIGH  
TEMPERATURES EITHER MAINLY MID TO UPPER 80S OR MID TO UPPER 90S IN A  
MAINLY DRY SCENARIO. THIS SPREAD CONTINUES ON SATURDAY (JULY 4TH)  
AND SUNDAY, BUT THE HIGH END TEMPERATURES TREND LESS HOT AS THE  
RIDGE BEGINS TO BREAK DOWN. AS SUCH, THE STORY FOR THE WEEKEND MAY  
BE POTENTIAL FOR FLOODING, AS A SURFACE BOUNDARY MAY EVENTUALLY  
BECOME STATIONARY TO OUR SOUTH WITH ROUNDS OF SHOWERS AND  
THUNDERSTORMS MOVING ACROSS THE NORTHEAST. THE DETAILS OF THIS ARE  
RATHER UNCLEAR AND DUE TO THE CONVECTIVE NATURE OF PRECIPITATION THE  
SIGNALS FOR WIDESPREAD HEAVY RAIN ARE LOW, BUT THIS HAZARD ALONGSIDE  
STRONG TO SEVERE THUNDERSTORMS OVER THE WEEKEND WILL NEED TO BE  
WATCHED, ESPECIALLY WHERE EARLIER WEEK CONVECTION HAD OCCURRED.  
 
 
   
AVIATION /06Z MONDAY THROUGH FRIDAY/  
 
THROUGH 06Z TUESDAY...VFR CONDITIONS AMIDST HIGH PRESSURE WILL  
PREVAIL ACROSS THE NEXT 24 HOURS. CANNOT RULE OUT A BRIEF OR  
INTERMITTENT PERIOD OF FOG AT SLK, MPV, OR EVEN MSS IN THE PRE-DAWN  
HOURS BUT CROSS OVER TEMPERATURES BASED ON YESTERDAY'S DRY AIR ARE  
QUITE LOW, MAKING IT UNFAVORABLE FOR FOG DESPITE THE CLEAR SKIES AND  
CALM WINDS. WINDS WILL REMAIN LIGHT AS IN RECENT DAYS, GENERALLY UP  
TO 5-8 KNOTS OUT OF THE NORTH.  
 
OUTLOOK...  
 
TUESDAY: VFR. CHANCE SHRA, SLIGHT CHANCE TSRA.  
TUESDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. CHANCE SHRA,  
CHANCE TSRA.  
WEDNESDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. CHANCE SHRA,  
CHANCE TSRA.  
WEDNESDAY NIGHT: VFR. CHANCE SHRA, CHANCE TSRA.  
THURSDAY: VFR. CHANCE SHRA, CHANCE TSRA.  
THURSDAY NIGHT: VFR. CHANCE SHRA, SLIGHT CHANCE TSRA.  
FRIDAY: MAINLY VFR, WITH AREAS MVFR POSSIBLE. CHANCE SHRA, CHANCE  
TSRA.  
 
 
   
CLIMATE  
 
EXTREME HEAT AND HUMIDITY IS POSSIBLE LATER THIS WEEK,  
ESPECIALLY ON WEDNESDAY AND THURSDAY, WHICH COULD LEAD TO SOME  
DAILY RECORDS. BELOW ARE THE CURRENT DAILY HIGH AND LOW  
TEMPERATURE RECORDS IN JEOPARDY AT OUR AREA CLIMATE SITES.  
 
RECORD HIGH TEMPERATURES:  
 
JUNE 30:  
KBTV: 93/2018  
 
JULY 1:  
KBTV: 96/2018  
KMPV: 92/2018  
KPBG: 94/1968  
KMSS: 94/2018  
 
JULY 2:  
KBTV: 97/2018  
KMPV: 90/2018  
KMSS: 94/2018  
 
JULY 3:  
KMPV: 91/2002  
 
RECORD HIGH MINIMUM TEMPERATURES:  
 
JULY 1:  
KBTV: 76/2018  
KPBG: 73/1971  
KSLK: 69/2018  
 
JULY 2:  
KPBG: 77/2002  
KSLK: 68/2002  
 
JULY 3:  
KBTV: 76/1911  
KPBG: 73/2002  
 
JULY 4:  
KPBG: 71/1973  
KSLK: 67/1952  
 
 
   
BTV WATCHES/WARNINGS/ADVISORIES  
 
VT...NONE.  
NY...NONE.  
 
 
 
 
 
WHAT HAS CHANGED...HASTINGS  
DISCUSSION...KUTIKOFF/HASTINGS  
AVIATION...KUTIKOFF  
CLIMATE...NWS BTV  
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