903  
FXUS61 KALY 182041  
AFDALY  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE ALBANY NY  
441 PM EDT THU JUL 18 2019  
   
SYNOPSIS
 
 
A FRONT THAT HAD SETTLED SOUTH OF THE REGION ON THURSDAY  
WILL LIFT NORTH AS A WARM FRONT ON FRIDAY. THIS WILL LEAD TO  
DANGEROUS HEAT AND OPPRESSIVE HUMIDITY THIS WEEKEND, ALONG WITH  
SCATTERED SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL DROP THROUGH  
THE REGION ON SUNDAY, WITH A RETURN TO SEASONABLE TEMPERATURES AND  
LOWER HUMIDITY TO START THE NEW WORK WEEK.  
 

 
   
NEAR TERM /UNTIL 6 AM FRIDAY MORNING/
 
 
FAIRLY TRANQUIL WEATHER IN PLACE THROUGH FRIDAY MORNING AS A  
COLD FRONT REMAINS SOUTH OF THE FORECAST AREA. SOME PARTIAL  
CLEARING HAS OCCURRED ACROSS THE REGION BUT PLENTY OF LOW LEVEL  
MOISTURE REMAINS IN PLACE. THIS WILL LEAD TO PRETTY MUGGY  
CONDITIONS OVERNIGHT WITH TEMPERATURES AND DEW POINTS IN THE  
60S. PATCHY FOG WILL BE POSSIBLE AS WELL.  
 

 
   
SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/
 
 
HEAT ADVISORY IN EFFECT FROM NOON FRIDAY TO NOON SATURDAY WITH  
AN EXCESSIVE HEAT WARNING IN EFFECT FROM NOON TO 8 PM SATURDAY  
FOR THE MOHAWK AND HUDSON RIVER VALLEYS, SOUTHERN TACONICS, AND  
LITCHFIELD COUNTY IN NW CT...  
 
HEAT ADVISORY HAS BEEN ISSUED FOR THE REMAINDER OF THE AREA FROM  
NOON TO 8 PM SATURDAY...  
 
THE COLD FRONT WILL LIFT NORTH AS A WARM FRONT THROUGHOUT THE  
DAY FRIDAY. THIS WILL RESULT IN A VERY WARM AND MUGGY AIR MASS  
IN PLACE FOR THE WEEKEND. THERE IS SOME QUESTION AS TO HOW  
QUICKLY MIXING WILL OCCUR TO ERODE THE SLIGHTLY COOLER, MARINE  
AIRMASS OUT. BUT WARM TEMPERATURES AND HIGHER HUMIDITY SHOULD BE  
IN PLACE ACROSS ALL AREAS BY THE AFTERNOON. DEW POINTS ARE  
EXPECTED TO RISE INTO THE LOWER 70S AS TEMPS SOAR INTO MID 80S  
TO LOW 90S. HOTTEST SPOTS WILL BE IN THE MOHAWK AND HUDSON  
VALLEYS AND WESTERN CT WHERE HEAT INDICES COULD EXCEED 100  
DEGREES.  
 
SOME HIGH-RES CAMS SUGGEST CONVECTION DEVELOPING IN THE WAKE OF  
THE WARM FRONT FOR FRIDAY AFTERNOON AND THEN ADDITIONAL  
CONVECTION UPSTREAM ACROSS THE GREAT LAKES DROPPING SOUTHWARD  
THROUGH THE REGION ALONG THE UPPER RIDGE AXIS FRIDAY EVENING  
INTO THE OVERNIGHT HOURS. THE LATEST SPC OUTLOOK HAS OUR AREA  
IN A MARGINAL RISK FOR SEVERE TO ACCOUNT FOR THIS POSSIBILITY.  
TRENDS WILL NEED TO BE WATCHED CLOSELY, AS THERE WILL BE  
ABUNDANT ELEVATED INSTABILITY AND STEEPENING MID LEVEL LAPSE  
RATES ON THE EASTERN EDGE OF AN ELEVATED MIXED LAYER (EML) AND  
ALSO ON THE SOUTHERN EDGE OF STRONGER MID LEVEL WINDS, WHICH  
COULD ALLOW UPSTREAM CONVECTIVE COMPLEXES TO RAPIDLY TRANSLATE  
INTO THE REGION, EVEN AT NIGHT. DAMAGING WINDS WOULD BE THE  
GREATEST THREAT SHOULD THUNDERSTORMS DEVELOP/OCCUR.  
 
SATURDAY-SATURDAY NIGHT, FULL IMPACTS OF HEAT AND HUMIDITY ARE  
EXPECTED, WITH HIGH TEMPERATURES REACHING THE MID/UPPER 90S IN  
MOST VALLEY AREAS, AND DEWPOINTS AT LEAST IN THE LOWER 70S,  
ALTHOUGH COULD BE EVEN HIGHER. HEAT INDICES SHOULD REACH AT  
LEAST 100-110 IN MOST VALLEY AREAS, AND 90-100 ACROSS HIGHER  
ELEVATIONS. WE HAVE ISSUED EXCESSIVE HEAT WARNING FOR MOST  
VALLEY AREAS WITH A HEAT ADVISORY ISSUED FOR ALL OTHER LOCATIONS  
ON SATURDAY. ANYONE SPENDING TIME OUTDOORS SATURDAY SHOULD TAKE  
MEASURES TO REMAIN COOL AND LIMIT POTENTIAL FOR HEAT STROKE.  
 
UNCERTAINTIES REMAIN REGARDING CONVECTIVE POTENTIAL FOR  
SATURDAY-SATURDAY NIGHT, AS MID LEVEL CAPPING LOOKS STRONG WITH  
EML PASSING THROUGH, BUT ANY UPSTREAM CONVECTIVE COMPLEXES FROM  
THE GREAT LAKES REGION COULD CONTINUE TO TRACK INTO PORTIONS OF  
THE REGION, WITH GREATEST CHANCES ACROSS THE ADIRONDACKS AND  
MOHAWK VALLEY REGION. WILL MAINTAIN SLIGHT TO CHANCE POPS FOR  
SCATTERED AFTERNOON/EVENING CONVECTION DURING THIS TIME. ANY  
CONVECTION THAT OCCURS COULD EASILY HAVE STRONG WIND GUSTS DUE  
TO STEEP LOW/MID LEVEL LAPSE RATES.  
 
SATURDAY NIGHT LOWS MAINLY 70-80 IN VALLEYS, AND 65-70 ACROSS  
HIGHER ELEVATIONS, WITH SOME VALLEY AREAS POSSIBLY ONLY DROPPING  
INTO THE MID/UPPER 70S.  
 

 
   
LONG TERM /SUNDAY THROUGH THURSDAY/
 
 
SUNDAY SHOULD FEATURE THE FINAL DAY OF THE WEEKEND HEAT WAVE AS A  
BROAD POSITIVELY TILTED TROUGH IN SE CANADA SLOWLY SLIDES SOUTH AND  
EAST TOWARDS THE NORTHEAST. WHILE 500MB HEIGHTS FALL THROUGH THE DAY  
WITH OUR HOT AND HUMID AIR MASS STILL IN PLACE, BUFKIT SOUNDINGS  
SHOW OUR ELEVATED MIXED LAYER (EML) IN PLACE WHICH MAY INITIALLY  
PROVIDE SUFFICIENT CAPPING TO PREVENT WIDESPREAD CONVECTION.  
HOWEVER, BY MIDDAY INTO THE AFTERNOON, MORE IMPRESSIVE HEIGHT FALLS  
SPREAD FROM NORTHWEST TO SOUTHEAST ACROSS OUR AREA WITH MSLP ISOBARS  
HINTING THAT A PRESSURE TROUGH SHOULD BE OVER EASTERN NY DURING THE  
AFTERNOON HOURS. THESE FEATURES SHOULD BRING ABOUT INCREASED FORCING  
FOR ASCENT THAT SHOULD ERODE AWAY OUR CAPPING INVERSION (AS NOTED BY  
700MB TEMPERATURES DROPPING BELOW 10C).  
 
ONCE THE CAP BREAKS, WE'LL HAVE TO WATCH FOR MORE WIDESPREAD  
CONVECTION AND WITH 0-6KM SHEAR VECTORS ORIENTED NEARLY  
PERPENDICULAR TO OUR PRESSURE TROUGH, A DISCRETE CONVECTIVE MODE  
LOOKS POSSIBLE. THANKS TO OUR EML, MID-LEVEL LAPSE RATES SHOULD BE  
QUITE IMPRESSIVE OVER 6.5C/KM AND OUR HOT/HUMID AIR MASS SHOULD  
PROVIDE VERY HIGH INSTABILITY VALUES (SB CAPE POTENTIALLY OVER  
2000J/KG). THE ONLY INGREDIENT THAT IS NOT SO IMPRESSIVE IS SHEAR.  
HOWEVER, MID-LEVEL FLOW SHOULD STRENGTHEN THROUGH THE DAY AS OUR  
TROUGH APPROACHES SO WE EXPECT DEEP LAYER SHEAR TO RISE TO NEAR 25-  
35KNOTS DURING THE SECOND HALF OF THE DAY. WITH SUCH FAVORABLE  
THERMODYNAMICS, SHEAR VECTORS SHOULD BECOME SUFFICIENT TO LEAD TO  
ORGANIZED CONVECTION WHICH INCREASES OUR CONCERNS FOR SEVERE  
WEATHER, DAMAGING WINDS BEING THE PRIMARY HAZARD.  
 
THE GENERAL MODEL CONSENSUS SHOWS OUR ACTUAL SURFACE COLD FRONT  
REACHING THE NY/CANADIAN BORDER BY 18Z SUNDAY. THIS BOUNDARY SHOULD  
PROVIDE SUFFICIENT LOW LEVEL FORCING AS IT IS CHARACTERIZED BY A  
RATHER IMPRESSIVE TEMPERATURE AND MOISTURE GRADIENT WITH 20-23C AT  
850MB WITHIN THE WARM SECTOR QUICKLY FALLING TO 11-13C BEHIND THE  
BOUNDARY. IN ADDITION, WE ALSO NOTE A SHARP WIND SHIFT ACROSS THE  
BOUNDARY. AS OUR COLD FRONT EVENTUALLY PUSHES INTO EASTERN  
NY/WESTERN NEW ENGLAND LATE IN THE DAY/EVENING, WE SHOULD SEE OUR  
CONVECTIVE MODE BECOME MORE LINEAR AS OUR SHEAR VECTORS BECOME  
PARALLEL TO OUR LIFTING MECHANISM. SEVERE WEATHER CONCERNS REMAIN IN  
PLACE GIVEN THE STRENGTHENING SHEAR VECTORS.  
 
BESIDES SEVERE WEATHER CONCERNS FOR SUNDAY, WE MAY HAVE TO REISSUE  
OUR HEAT ADVISORY AND EXCESSIVE HEAT WARNING HEADLINES, ESPECIALLY  
FOR THE HUDSON VALLEY. HIGH TEMPERATURES ONCE AGAIN MAY REACH INTO  
THE 90S WITH VERY HIGH HUMIDITY VALUES LEADING TO HEAT INDICES IN  
EXCESS OF 95F WITH EVEN OVER 100F IN THE MID-HUDSON VALLEY AND  
PORTIONS OF NW CT.  
 
THERE IS GOOD AGREEMENT AMONG THE GUIDANCE THAT OUR COLD FRONT  
SHOULD BE VERY SLOW MOVING AS ITS PARENT BROAD, POSITIVELY TROUGH  
GRADUALLY PUSHING EASTWARD OVERNIGHT. MOST MEMBERS OF GUIDANCE ONLY  
HAVE OUR COLD FRONT IN THE MID-HUDSON VALLEY/NW CT BY 12Z MONDAY SO  
WE CONTINUED TO SHOW CHANCE POPS FOR SHOWERS/THUNDERSTORMS MOST OF  
MONDAY IN OUR SOUTHERN ZONES WITH LOWER POPS NORTH AND WEST OF THE  
CAPITAL REGION. TEMPERATURES SHOULD FINALLY BE MORE TOLERABLE IN THE  
WAKE OF OUR COLD FRONT WITH HIGH TEMPERATURES MONDAY ONLY IN THE MID  
70S TO LOW 80S. DEW POINTS, HOWEVER, MAY STILL BE HIGH (ESPECIALLY  
IN SOUTHERN ZONES) AS OUR COLD FRONT WILL STILL BE NEARBY, KEEPING  
IT FEELING MUGGY.  
 
OUR COLD FRONT SHOULD FINALLY CLEAR THE AREA BY 00Z TUESDAY WITH  
COOLER AND LESS HUMID AIR SPREADING INTO EASTERN NY AND WESTERN NEW  
ENGLAND. SKIES SHOULD ALSO BECOME PARTLY CLEAR AS MID-LEVEL DRY AIR  
MOVES INTO AREA SO OVERNIGHT LOWS SHOULD BECOME MORE COMFORTABLE IN  
THE 50S TO LOW 60S.  
 
TUESDAY SHOULD BE A PLEASANT AND SEASONABLY COOL DAY WITH HIGHS ONLY  
IN THE 70S TO NEAR 80 AS CANADIAN HIGH PRESSURE TAKES CONTROL OF THE  
AREA. HOWEVER, UNSETTLED CONDITIONS RESUME FOR WEDNESDAY/THURSDAY AS  
OUR UPPER LEVEL TROUGH AXIS MOVES OVERHEAD. TEMPERATURES SHOULD  
REMAIN TOLERABLE IN THE 70S TO NEAR 80 BOTH DAYS.  
 

 
   
AVIATION /19Z THURSDAY THROUGH TUESDAY/
 
 
A FRONTAL BOUNDARY IS SITUATED JUST SOUTH OF THE REGION. PLENTY OF  
LINGERING LOW LEVEL MOISTURE CLOSE TO THE BOUNDARY IS KEEPING FLYING  
CONDITIONS MVFR FOR KALB, KPSF AND KPOU. ALTHOUGH THERE MAY BE A  
BRIEF RETURN BACK TO VFR LATER THIS AFTERNOON, MOST SITES SHOULD  
CONTINUE TO BE MAINLY MVFR THROUGH THE REST OF THE DAY. THERE COULD  
BE A FEW PASSING LIGHT RAIN SHOWERS AS WELL, BUT INTENSITY WILL BE  
LIGHT, DURATION WILL BE BRIEF AND IMPACTS SHOULD BE MINIMAL, SO WILL  
MAINLY ADDRESS IT AS A VCSH FOR NOW. NORTHERLY WINDS WILL EVENTUALLY  
BECOME EAST TO SOUTHEAST BY LATE THIS AFTERNOON INTO THIS EVENING,  
BUT SPEEDS WILL GENERALLY BE 5 KTS OR LESS.  
 
MVFR CONDITIONS ARE EXPECTED OVERNIGHT FOR ALL SITES DUE TO LOW  
STRATUS WITH CEILINGS 1-2 KFT FOR ALL SITES. CANNOT RULE OUT SOME  
MIST FORMING LATE AS WELL, BUT THE ABUNDANT LOW CLOUDS SHOULD  
PREVENT THE MIST FROM BECOMING TOO DENSE. VERY LIGHT OR CALM WINDS  
EXPECTED TONIGHT.  
 
ON FRIDAY MORNING, LOW CLOUDS SHOULD FINALLY START TO BREAK UP BY  
THE MID MORNING HOURS, ALLOWING FOR VFR CONDITIONS TO RETURN TO ALL  
SITES, WITH JUST SOME SCT CLOUDS LINGERING THROUGH THE REST OF THE  
DAY. SOUTHERLY WINDS WILL BE 5 TO 10 KTS.  
 
OUTLOOK...  
 
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.  
SATURDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.  
SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.  
SUNDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.  
SUNDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA.  
MONDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.  
 

 
   
FIRE WEATHER
 
 
A FRONT THAT HAD SETTLED SOUTH OF THE REGION ON THURSDAY  
WILL LIFT NORTH AS A WARM FRONT ON FRIDAY. THIS WILL LEAD TO  
DANGEROUS HEAT AND OPPRESSIVE HUMIDITY THIS WEEKEND, ALONG WITH  
SCATTERED SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL DROP THROUGH  
THE REGION ON SUNDAY, WITH A RETURN TO SEASONABLE TEMPERATURES AND  
LOWER HUMIDITY TO START THE NEW WORK WEEK.  
 
RH WILL ONLY FALL TO 50-60 PERCENT FRIDAY AFTERNOON AND 55 TO 80  
PERCENT SATURDAY NIGHT. RH WILL RECOVER TO NEAR 100 PERCENT  
TONIGHT AND FRIDAY NIGHT.  
 
WINDS WILL BECOME BECOME SOUTHEAST TO SOUTH AT LESS THAN 10  
MPH TONIGHT. WINDS WILL BECOME SOUTH TO SOUTHWEST BY FRIDAY  
AFTERNOON AT 5-15 MPH.  
 
WINDS WILL BE STRONGER, AND VARIABLE IN DIRECTION IN AND NEAR  
ANY THUNDERSTORMS.  
 

 
   
HYDROLOGY
 
 
ISOLATED TO SCATTERED, MAINLY AFTERNOON/EVENING SHOWERS AND  
THUNDERSTORMS WILL BE POSSIBLE THROUGH THE UPCOMING WEEKEND,  
WITH THE MOST WIDESPREAD COVERAGE EXPECTED SUNDAY AFTERNOON INTO  
MONDAY AS A COLD FRONT CROSSES THE REGION.  
 
PLEASE VISIT OUR ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ WEB  
PAGE FOR SPECIFIC AREA RIVERS AND LAKES OBSERVATIONS AND  
FORECASTS.  
 

 
   
ALY WATCHES/WARNINGS/ADVISORIES
 
 
CT...EXCESSIVE HEAT WARNING FROM NOON TO 8 PM EDT SATURDAY FOR  
CTZ001-013.  
HEAT ADVISORY FROM NOON FRIDAY TO NOON EDT SATURDAY FOR CTZ001-  
013.  
NY...HEAT ADVISORY FROM NOON TO 8 PM EDT SATURDAY FOR NYZ032-033-  
042-047-051-054-058-061-063-082.  
EXCESSIVE HEAT WARNING FROM NOON TO 8 PM EDT SATURDAY FOR  
NYZ038>041-048>050-052-053-059-060-064>066-083-084.  
HEAT ADVISORY FROM NOON FRIDAY TO NOON EDT SATURDAY FOR  
NYZ038>041-048>050-052-053-059-060-064>066-083-084.  
HEAT ADVISORY FROM NOON FRIDAY TO 8 PM EDT SATURDAY FOR NYZ043.  
MA...HEAT ADVISORY FROM NOON TO 8 PM EDT SATURDAY FOR MAZ001-025.  
VT...HEAT ADVISORY FROM NOON TO 8 PM EDT SATURDAY FOR VTZ013>015.  
 

 
 

 
SYNOPSIS...JLV  
NEAR TERM...JLV  
SHORT TERM...KL/JLV  
LONG TERM...SPECIALE  
AVIATION...FRUGIS  
FIRE WEATHER...JLV  
HYDROLOGY...JLV  
 
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