795  
FXUS61 KBTV 150235  
AFDBTV  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BURLINGTON VT  
1035 PM EDT SUN JUL 14 2024  
   
SYNOPSIS
 
 
AFTER A QUIET END TO THE WEEKEND, HEAT, HUMIDITY, AND SCATTERED  
SHOWERS AND THUNDERSTORMS ARE FORECAST FOR MONDAY AND TUESDAY,  
FOLLOWED BY AN ADDITIONAL CHANCE FOR THUNDERSTORMS ON WEDNESDAY.  
FOLLOWING A COLD FRONT PASSAGE WEDNESDAY NIGHT, COOLER AND DRIER  
WEATHER IS EXPECTED FOR THE END OF THE WEEK AND INTO NEXT WEEKEND.  
 

 
   
NEAR TERM /THROUGH TUESDAY/
 
 
AS OF 1035 PM EDT SUNDAY...FORECAST REMAINS IN GOOD SHAPE WITH  
CHANCES OF SHOWERS STILL ON TRACK TO LARGELY RAMP UP AFTER  
MIDNIGHT WITH GREATEST CHANCES GENERALLY FROM FRANKLIN COUNTY,  
NEW YORK EASTWARD ACROSS NORTHERNMOST PORTIONS OF VERMONT.  
MESOANALYSIS SHOWS A SHARP MOISTURE GRADIENT WITH 850 MILLIBAR  
TRANSPORT POINTED EAST-NORTHEASTWARD, SUCH THAT EVENTUALLY  
CLOUDS WILL LOWER AND SHOWERS SHOULD DEVELOP IN SPITE OF WEAK  
DYNAMIC FORCING AND LACK OF INSTABILITY. SOUTHERLY LOW LEVEL  
FLOW WILL HELP HELP INCREASE SURFACE CONVERGENCE IN THE NORTHERN  
CHAMPLAIN VALLEY, AS WELL, SO POPS UP INTO THE 30-40% RANGE  
TOWARDS DAYBREAK LOOK GOOD IN THAT AREA. MOST LOCATIONS THAT SEE  
RAIN WILL ONLY SEE A FEW HUNDREDTHS OF AN INCH OF RAIN, WITH  
PERHAPS A SPOT OR TWO THAT SEES OVER A 0.1".  
 
PREVIOUS DISCUSSION...  
SURFACE HIGH PRESSURE AND A WEAK RIDGE ALOFT PROVIDED A  
BEAUTIFUL END TO THE WEEKEND WITH WARM TEMPERATURES IN THE 80S  
AND SLIGHTLY MORE COMFORTABLE DEWPOINTS IN THE LOWER 60S.  
TONIGHT, A DECAYING MID-LEVEL SHORTWAVE TROUGH WILL TRACK  
EASTWARD FROM THE GREAT LAKES AND BRING A CHANCE FOR SHOWERS AND  
EMBEDDED THUNDER TO PORTIONS OF NORTHERN NEW YORK, BUT MOST OF  
VERMONT SHOULD REMAIN DRY. CLOUDS INCREASE ACROSS THE ENTIRE  
REGION THROUGH THE OVERNIGHT, HELPING TO KEEP MIN TEMPS MILD IN  
THE MID-60S TO LOW-70S. ON MONDAY THE REMNANT SHORTWAVE ENERGY  
PASSES THROUGH THE REGION AND COMBINED WITH INCREASING HUMIDITY  
AND INSTABILITY, WE SHOULD SEE SCATTERED SHOWERS AND  
THUNDERSTORMS DEVELOP THROUGH THE AFTERNOON. A LACK OF ANY DEEP  
LAYER SHEAR SUPPORTS STORMS BEING MORE OF THE GARDEN VARIETY,  
BUT BASED ON LOW FLASH FLOOD GUIDANCE AND PWATS SURGING BACK  
TOWARDS 2", ANY STRONGER CORES WILL BE CAPABLE OF PRODUCING SOME  
ISOLATED FLASH FLOODING IF RAINFALL EXCEEDS 1" IN AN HOUR,  
ESPECIALLY ACROSS CENTRAL AND NORTHERN VERMONT. IN ADDITION,  
WITH HIGH TEMPS RISING INTO THE UPPER 80S TO LOW 90S AND  
DEWPOINTS BACK INTO THE UPPER 60S, HEAT INDICES ARE EXPECTED TO  
RISE INTO THE MID/UPPER 90S FOR PORTIONS OF CENTRAL/SOUTHERN  
CHAMPLAIN VALLEY WHERE A HEAT ADVISORY HAS BEEN ISSUED.  
 
AFTERNOON CONVECTION SHOULD WANE WITH THE LOSS OF SURFACE  
HEATING AFTER SUNSET, WITH SOME LINGERING ISOLATED SHOWERS AND  
THUNDERSTORMS THROUGH MIDNIGHT. IT SHOULD BE ANOTHER STEAMY  
OVERNIGHT WITH LOWS ONLY IN THE UPPER 60S TO LOW 70S AGAIN, AND  
DEWPOINTS ONLY A FEW DEGREES BELOW FOR HUMIDITY CLOSE TO 100%.  
 

 
   
SHORT TERM /TUESDAY NIGHT/
 
 
AS OF 256 PM EDT SUNDAY...TUESDAY IS LIKELY TO BE ANOTHER WARM AND  
HUMID DAY. HEAT INDICES ARE LIKELY TO CLIMB INTO THE 90S ACROSS THE  
REGION AS WARM, MOIST AIR LIFTS NORTHEAST AHEAD OF A COLD FRONT  
STRETCHING OUT TO OUR WEST. INTERESTINGLY, THE SOURCE OF MOISTURE ON  
TUESDAY WILL BE FROM A ROUND ABOUT CONNECTION FROM THE PACIFIC OCEAN  
UP THROUGH THE BAJA INTO THE INTERMOUNTAIN WEST BEFORE MAKING A  
BEELINE ACROSS THE PLAINS. THIS LEAVES ME SLIGHTLY SKEPTICAL WE CAN  
ACHIEVE TRULY OPPRESSIVE DEWPOINTS WE CAN GET OUT OF THE GULF OF  
MEXICO, BUT ALMOST ALL GUIDANCE HAS UPPER 60S TO LOWER 70S. IT'S  
HARD TO BEAT PERSISTENCE. HEAT ADVISORIES ARE PRESENTLY COVERING  
PART OF THE CHAMPLAIN VALLEY, AND WILL LIKELY BE NEEDED FOR THE  
CONNECTICUT RIVER VALLEY AS WELL. IT WILL LIKELY BE ADDED TO THE  
EXISTING HEAT ADVISORY TOMORROW.  
 
THE PICTURE FOR THUNDERSTORMS IS SOMEWHAT COMPLICATED. THERE ARE  
SOME TIMING DISCREPANCIES WITH THE SHORTWAVE EXPECTED TO CROSS THE  
AREA TUESDAY AFTERNOON. IT SEEMS MONDAY NIGHT'S CONVECTION AND  
TROUGH WILL PLACE SOME STABLE AIR ACROSS THE REGION INITIALLY. THIS  
SHOULD ALLOW THE EFFICIENT WARMING EXPECTED ON TUESDAY, BUT THE  
QUESTION IS HOW MUCH INSTABILITY RECOVERY CAN TAKE PLACE. IF THE  
SHORTWAVE IS TOO EARLY, WE MAY BE ABLE TO ESCAPE MUCH IMPACT, BUT IF  
THE SHORTWAVE IS DELAYED UNTIL LATER IN THE AFTERNOON, THERE WILL BE  
UPWARDS OF 1500 J/KG OF CAPE, 0-6KM SHEAR OF 30 TO 40 KNOTS, AND  
1.50-2.00" PWATS. AS NOTED BEFORE, THE MESO-BETA VECTORS ARE SLOW,  
AND SO THUNDERSTORMS MAY NOT BE IN ANY REAL HURRY OR COULD BACKBUILD  
DESPITE SOME PRESENT FLOW. SO THE WESTERN HALF OF VERMONT AND  
NORTHERN NEW YORK ARE IN A MARGINAL RISK OUTLOOK FOR EXCESSIVE RAIN,  
AND WE ARE IN A MARGINAL RISK OUTLOOK FOR LOCALIZED SEVERE STORMS.  
GIVEN THE POTENTIAL SEEMS CONDITIONAL, THIS ALL SEEMS REASONABLE.  
SOME LINGERING SHOWERS ARE EXPECTED OVERNIGHT, FOLLOWED BY A  
PREFRONTAL TROUGH THAT SHIFTS EVERYTHING OUT, AND THAT MEANS A HUMID  
NIGHT IN THE MID 60S TO LOWER 70S IS ANTICIPATED.  
 

 
   
LONG TERM /WEDNESDAY THROUGH SATURDAY/
 
 
AS OF 256 PM EDT SUNDAY...THE EXTENDED BEGINS WITH A FRONTAL BOUNDARY  
AT OUR DOORSTEP. THE STRETCHED OUT COLD FRONT TO OUR WEST WILL ONLY  
SLOWLY SHIFT EAST. HOWEVER, A LARGE UPPER TROUGH BEGIN TO FORCE IT  
TO MAKE SOME EASTWARD PROGRESS. THE QUESTION IS, EXACTLY HOW FAST  
WILL THAT BE. A SLOWER FRONT MEANS A WARMER WEDNESDAY WITH MORE  
CHANCES TO DESTABILIZE, WHILE A FASTER FRONT WOULD RESULT IN  
ACTIVITY LIMITED TO THE GREEN MOUNTAINS EASTWARDS. THE UPPER TROUGH  
IS GOING TO LAG BEHIND, BUT IT WILL SEND COOLER, LESS HUMID AIR  
EASTWARDS. SO IF THINGS DON'T LINE UP WELL, WE COULD BE ON THE DRIER  
SIDE. PROBABILISTIC GUIDANCE SUGGESTS ONE SHOULD NOT BE TOO  
OPTIMISTIC WITH THE CHANCE OF EXCEEDING 0.10" AT GREATER THAN 50  
PERCENT. THE CLUSTERING OF DRIER ENSEMBLES ARE LESS THAN 20 PERCENT  
TOO. TO COMPLICATE MATTERS, THE 12Z DETERMINISTIC RUNS CAME IN WITH  
A RELATIVELY DRY WEDNESDAY WITH A FAST FRONTAL PROGRESSION, THOUGH.  
FOR NOW, THE FORECAST CHANGES LITTLE FROM THE PREVIOUS FORECAST. THE  
FOCUS IS MOST LIKELY TO BE THE SOUTHERN HALF OF VERMONT THOUGH, AND  
SO HAVE STUCK CLOSELY TO BLENDED DATA FOR RAINFALL FORECASTS FOR NOW  
WHICH HIGHLIGHTS THAT WELL ENOUGH.  
 
A FEW SHOWERS COULD DEVELOP ON THURSDAY AS THE UPPER TROUGH AMBLES  
EAST, BUT THERE WILL BE A LOT OF HAPPY PEOPLE AS TEMPERATURES TREND  
SLIGHTLY BELOW NORMAL! DRY HIGH PRESSURE SETS UP, AND WE'LL BE  
LOOKING AT PLEASANT WEATHER CONDITIONS THROUGH SATURDAY. ALTHOUGH  
TEMPERATURES WILL BEGIN TO CLIMB BACK UP ABOVE NORMAL, THERE WILL  
NOT BE THE OPPRESSIVE HUMIDITY. THEN, THERE'S A REINFORCING COLD  
FRONT SOMETIME EARLY NEXT WEEK. IT WILL COME WITH SOME SHOWERS, BUT  
NOTHING SIGNIFICANT AS IT COMES FROM THE NORTH WITHOUT A TROPICAL  
MOISTURE FEED.  
 

 
   
AVIATION /03Z MONDAY THROUGH FRIDAY/
 
 
THROUGH 00Z TUESDAY...VFR CONDITIONS WILL PREVAIL THROUGH THE  
PERIOD. TEMPORARY VISIBILITY REDUCTIONS DUE TO AN UNLIKELY  
DIRECT HIT OF A HEAVIER SHOWER, ESPECIALLY LATE IN THE PERIOD,  
IS POSSIBLE AT MOST SITES. HOWEVER, COVERAGE OF THESE VARIETY  
OF SHOWERS AND THUNDERSTORMS LOOKS ISOLATED.  
 
IN THE 00Z TO 02Z PERIOD, AN AREA OF LIGHT SHOWERS CURRENTLY  
OVER EASTERN LAKE ONTARIO MAY MOVE THROUGH KMSS AND KSLK  
OVERNIGHT BUT SHOULDN'T FLIGHT CONDITIONS. ADDITIONAL VERY LIGHT  
RAIN IS POSSIBLE THERE AND POSSIBLY UP THROUGH THE NORTHERN  
CHAMPLAIN VALLEY THROUGH 12Z. TOWARDS 16Z, SCATTERED SHOWERS  
AND THUNDERSTORMS WILL DEVELOP WITH SKIES SCT-BKN.  
 
WINDS OVERNIGHT WILL BE MAINLY <5KTS, THEN SOUTH/SOUTHWEST AT  
6-11KTS AFTER 14Z MONDAY.  
 
OUTLOOK...  
 
MONDAY NIGHT: VFR. SCATTERED SHRA, SCATTERED TSRA.  
TUESDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. CHANCE SHRA,  
SLIGHT CHANCE TSRA.  
TUESDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. CHANCE SHRA.  
WEDNESDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. CHANCE SHRA,  
SLIGHT CHANCE TSRA.  
WEDNESDAY NIGHT: VFR. CHANCE SHRA.  
THURSDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. CHANCE SHRA,  
SLIGHT CHANCE TSRA.  
THURSDAY NIGHT: VFR. SLIGHT CHANCE SHRA.  
FRIDAY: VFR. NO SIG WX.  
 

 
   
BTV WATCHES/WARNINGS/ADVISORIES
 
 
VT...HEAT ADVISORY FROM NOON MONDAY TO 8 PM EDT TUESDAY FOR VTZ005-  
009-011.  
NY...HEAT ADVISORY FROM NOON MONDAY TO 8 PM EDT TUESDAY FOR NYZ035.  
 

 
 

 
SYNOPSIS...LAHIFF  
NEAR TERM...KUTIKOFF/LAHIFF  
SHORT TERM...HAYNES  
LONG TERM...HAYNES  
AVIATION...KUTIKOFF/LAHIFF  
 
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