Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/12/16


AREA FORECAST DISCUSSION
National Weather Service Eureka CA
422 AM PDT SUN JUL 10 2016 .SYNOPSIS...Cool and moist conditions will persist across the interior of northwestern California through this evening, with a few light showers possible today, mainly across northern Humboldt and Del Norte counties, and maybe into the Trinity horn. For the remainder of the week, dry conditions will prevail area-wide with temperatures increasing across the interior. && .DISCUSSION... .SHORT TERM... (Today and Tonight) The much talked about storm system continues to slowly churn south just offshore from the Oregon coast. Forcing aloft associated with this is starting to increase across northern portions of the forecast area, with showers development increasing on the latest Doppler radar loops. As has been the case the past couple of days, northern Humboldt and Del Norte areas seem to be the favored spots, especially along the coast. However, the radar loop also shows some very small/light showers trying to make a run at locations south and east of there. Have doubts that any of these showers will survive the trip into Mendocino and Trinity counties due to lower surface dewpoints, but some light drizzle isn`t totally impossible here. Otherwise, the system will begin to depart the region today, with any shower activity ending by mid to late afternoon. The one exception to this could be far Del Norte County, as some wrap around moisture could clip these areas. .LONG TERM... (Monday through Saturday) A return to a summertime pattern is on tap for the remainder of the week. A zonal flow aloft will develop with surface high pressure strengthening across the eastern Pacific. This will yield a classic northerly flow setup along the coast, with episodic morning stratus/fog possible. Farther inland, increasing temperatures under mainly clear skies will dominate your weather this week. /PD && .AVIATION...Low clouds continue across the Redwood Coast and inland to W Trinity County with patches of very light rain and drizzle. Skies elsewhere are mostly clear. The HRRR model keeps patchy precip around KACV through about 14Z while KCEC may see light precip into the afternoon hours. Clouds are expected to erode over the interior with daytime heating, but broken low cloudiness will likely hold over the coastal terminals. As expected, N winds have remained up at KUKI overnight. These winds will gradually subside through the morning hours. Elsewhere, winds will be generally light. /SEC && .MARINE...Light winds will continue through today with the wind direction more southerly N of Cape Mendocino this morning ahead of a frontal trough. N winds are expected to return by tonight, and a small craft advisory continues for the S offshore waters during that time period. Winds will need to be monitored in the S nearshore zone, but at this time, wind speeds are progged to remain just below advisory criteria. More widespread northerlies are progged by the middle of the this week as high pressure over the E Pacific rebuilds toward the area and the inland thermal trough sharpens. /SEC && .EKA Watches/Warnings/Advisories... CA...None. NORTHWEST CALIFORNIA COASTAL WATERS...Small Craft Advisory from 3 PM this afternoon to 11 PM PDT Wednesday for PZZ475. && $$ Visit us at http://WWW.WEATHER.GOV/EUREKA Follow us on facebook and twitter at: http://www.facebook.com/NWSEureka http://www.twitter.com/nwseureka FOR FORECAST ZONE INFORMATION SEE FORECAST ZONE MAP ONLINE: http://www.weather.gov/eureka/zonemap.png Area Forecast Discussion National Weather Service New York NY 1044 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Some slight adjustments were made regarding the temperatures, dewpoints, and cloud coverage to better match observed trends. The forecast overall remains on track. High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Cirrus clouds decrease overnight with the high pressure center moving closer and with some ridging aloft. With increasing low level moisture and light onshore flow along with cooling temperatures, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior and rural portions of the CWA will drop into the mid to upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. There is a moderate risk of rip current development at the Atlantic facing beaches on Tuesday. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area through Tuesday. This will result in mainly VFR conditions with southerly winds. Gradient tightens Tuesday afternoon with some of the coastal terminals increasing to around 15 kt. Patchy MVFR BR at rural airports towards sunrise. .OUTLOOK FOR 00Z Wednesday through Saturday... .Tue Night-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...JM/MPS SHORT TERM...MPS LONG TERM...JC AVIATION...DW MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service New York NY 1044 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Some slight adjustments were made regarding the temperatures, dewpoints, and cloud coverage to better match observed trends. The forecast overall remains on track. High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Cirrus clouds decrease overnight with the high pressure center moving closer and with some ridging aloft. With increasing low level moisture and light onshore flow along with cooling temperatures, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior and rural portions of the CWA will drop into the mid to upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. There is a moderate risk of rip current development at the Atlantic facing beaches on Tuesday. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area through Tuesday. This will result in mainly VFR conditions with southerly winds. Gradient tightens Tuesday afternoon with some of the coastal terminals increasing to around 15 kt. Patchy MVFR BR at rural airports towards sunrise. .OUTLOOK FOR 00Z Wednesday through Saturday... .Tue Night-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...JM/MPS SHORT TERM...MPS LONG TERM...JC AVIATION...DW MARINE...JC/MPS HYDROLOGY...JC/MPS
  [top] Area Forecast Discussion National Weather Service Taunton MA 946 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure over New England will become centered southeast of New England during Tuesday. Heat and humidity will increase this week with the high remaining centered offshore, bringing a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 945 pm Update... Quiet night. High clouds moving out of region per IR satellite, which will leave mostly clear skies and light winds. This will allow temperatures to drop off quickly overnight, especially in interior valleys where patchy fog should also form. May also see some fog near RI/MA South Coast. Lows in 50s to lower 60s look good. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Tuesday... The surface high becomes centered offshore during the day, while upper level ridge builds towards our area from the west. Southern New England gets into return low level SW flow which will begin to bring warmer and eventually more humid air into region. Mostly sunny skies expected, mainly from diurnal cumulus but could see a few higher deck clouds as well. Temperatures rise well into the 80s across much of the area. Exception will be along south coastal MA/RI, where highs in the 70s to near 80 are expected. Expecting an eventual sea breeze development along east coastal MA, but may take into midday/early afternoon to get going and overcome SW flow. Tuesday night... Surface high pressure centered offshore and light SW return flow continues. Upper ridge axis extends over New England. This will be a slightly warmer and more humid night, with lows in the 60s. Could see some patchy valley fog once more, otherwise mostly clear skies expected. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Big Picture... Longwave pattern shows steady heights through the week followed by building heights off the Atlantic Sunday and Monday. Shortwave scale shows an upper ridge with axis over New England Wednesday, shifting southeast Thursday and Friday. Shortwave over the Upper Midwest Wednesday moves into Eastern Canada and sweeps a weak shortwave across New England Friday night. Subtropical high over the Atlantic builds Sunday and Monday while another shortwave approaches from the west on Monday. General model agreement Wednesday to Friday, but uncertainty for Saturday and Sunday. Both show the Friday night cold front stalling to our south. Both the 12Z GFS and ECMWF show dry weather Saturday followed by a wave moving up the front spreading showers into our area Sunday. Earlier runs showed that wave moving past with wet weather Saturday followed by dry weather Sunday. All show high pressure and dry weather Monday. Low confidence as to which will be right for the weekend. We have chosen to compromise between the two camps for now and allow the next couple of runs provide clearer information. Details... Wednesday through Friday... High pressure offshore with a developing southwest flow over the region. This will bring in increasing dew points through the period. Temperatures aloft also increase with 850-equivalent temps 16-17C Wednesday increasing to 18-20C Thursday and Friday. Airmass also becomes increasingly unstable each day with LIs near zero in the CT Valley Wednesday but with limited cloud moisture, then sub-zero LIs across much of the area Thursday and at least part of Friday. Based on this, expect hot temps during this period with max temps either side of 90 Wednesday, and 90-95 Thursday and Friday. Dew points climb to around 70 by Friday morning so humidity levels will be at least noticeable and eventually oppressive. There is a small chance of a thunderstorm in far western MA Wednesday. Thunderstorms more likely Thursday afternoon through Friday. One concern...the GFS and EC both rush precipitation through on Friday morning, while maintaining southwest winds most areas until Friday evening. Perhaps this is focusing showers on a pre-frontal trough and keeping the main front dry. Temps aloft stay warm through the afternoon supporting the idea of a later cold fropa. We massaged the available grid data to keep chance pops into mid afternoon. Specific timing of convection is probably questionable this far out, with the important idea being that there will be precipitation during some part of Friday. Saturday-Sunday-Monday... Much uncertainty in the forecast and forecast data at this time. As noted above, the 12z GFS and EC show a low pressure wave passing us on Sunday with showers while much of the forecast grid data shows showers on Saturday and dry on Sunday. Previous model suites also went with wet weather on Saturday. We have hand-edited our database to show chance pops both days. Expect later model runs will resolve this timing to one day or the other. High pressure brings drier seasonable weather on Monday. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Overnight...High confidence. VFR with mostly clear skies. Local MVFR/IFR possible overnight in patchy valley fog, as well as a possibility for patchy stratus/fog overnight along south coastal MA/southern RI. Tuesday and Tuesday night...High confidence. VFR, with local MVFR possible Tuesday night in patchy valley fog once again. Prevailing S/SW winds Tue which should prevent sea breeze development along E MA coast. KBOS TAF...High confidence. VFR. SW flow Tue should be just strong enough to prevent sea breeze from coming onshore. KBDL TAF...High confidence. VFR. Outlook /Wednesday through Saturday/... Wednesday through Friday... Moderate Confidence. VFR. Areas if late night/early morning IFR in fog. Scattered MVFR/IFR in afternoon and evening showers/thunderstorms, mainly Thursday and Friday. Winds becoming southwest much of the period. Saturday... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England through tonight, and becomes centered offshore during Tuesday. Light and variable wind becomes prevailing SW later tonight and Tuesday, except for local sea breezes redeveloping on Tuesday. Outlook /Wednesday through Saturday/... Moderate confidence. Winds below 25 knots through the period. Seas mainly below 5 feet, although there is potential for brief 5 foot seas on the outer waters Thursday night and Friday. Winds becoming southwest for most of the period. Areas of poor visibility in overnight and morning fog. Scattered showers/thunderstorms mainly Thursday and Friday. Low confidence on showers for Saturday. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...WTB/NMB NEAR TERM...JWD SHORT TERM...NMB LONG TERM...WTB AVIATION...WTB/NMB/JWD MARINE...WTB/NMB
  [top] Area Forecast Discussion National Weather Service Albany NY 945 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 945 PM EDT...Mainly clear to partly cloudy skies are expected overnight with some patchy fog likely developing in river valleys. It will be cool once again tonight, with low temperatures before daybreak falling into the upper 40s to upper 50s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. This will be followed by a return ton VFR conditions for the day on Tuesday. Satellite imagery reveals few cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Skies will return to sct045 sct-bkn250 during the day on Tuesday. Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift to the south to southwest at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...KL/11 SHORT TERM...KL LONG TERM...11 AVIATION...KL/11 FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service New York NY 757 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Some slight adjustments were made to the forecast regarding the temperatures, dewpoints, and cloud coverage to better match observed trends. Otherwise, the forecast overall remains on track. High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Some initial higher coverage of cirrus clouds will decrease later this evening with the high pressure center moving closer and with some ridging aloft. Skies will further clear out overnight with high pressure and its subsidence prevailing. With increasing low level moisture and light onshore flow, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior portions of the CWA will drop into the upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. There is a moderate risk of rip current development at the Atlantic facing beaches on Tuesday. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area through Tuesday. This will result in mainly VFR conditions with southerly winds. Gradient tightens Tuesday afternoon with some of the coastal terminals increasing to around 15 kt. Patchy MVFR BR at rural airports towards sunrise. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component FCSTS can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments expected. KLGA TAF Comments: NE winds may persist through 01Z before shifting around to the S/SE. KEWR TAF Comments: No unscheduled amendments expected. KTEB TAF Comments: NE winds may persist through 01Z before shifting around to the S/SE. KHPN TAF Comments: No unscheduled amendments expected. KISP TAF Comments: No unscheduled amendments expected. .OUTLOOK FOR 00Z Wednesday through Saturday... .Tue Night-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...JM/MPS SHORT TERM...MPS LONG TERM...JC AVIATION...DW MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service Albany NY 708 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 630 PM EDT...Patchy high clouds continue to stream across portions of the region, especially from around I-90 southward. This may be at least in part in association with a jet max retreating off the New England coast, with our area within its right entrance region. This jet max is expected to translate farther off the coast this evening, and should allow its influence and associated high clouds to decrease. So, partly cloudy this evening, then becoming mostly clear overnight. Some patchy fog will likely develop in river valleys, given that mixing was not very strong/deep this afternoon, and afternoon dewpoints held in the 50s. It will be cool once again tonight, with low temperatures before daybreak falling into the 50s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. This will be followed by a return ton VFR conditions for the day on Tuesday. Satellite imagery reveals few cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Skies will return to sct045 sct-bkn250 during the day on Tuesday. Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift to the south to southwest at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...KL/11 SHORT TERM...KL LONG TERM...11 AVIATION...KL/11 FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service Albany NY 708 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 630 PM EDT...Patchy high clouds continue to stream across portions of the region, especially from around I-90 southward. This may be at least in part in association with a jet max retreating off the New England coast, with our area within its right entrance region. This jet max is expected to translate farther off the coast this evening, and should allow its influence and associated high clouds to decrease. So, partly cloudy this evening, then becoming mostly clear overnight. Some patchy fog will likely develop in river valleys, given that mixing was not very strong/deep this afternoon, and afternoon dewpoints held in the 50s. It will be cool once again tonight, with low temperatures before daybreak falling into the 50s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. This will be followed by a return ton VFR conditions for the day on Tuesday. Satellite imagery reveals few cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Skies will return to sct045 sct-bkn250 during the day on Tuesday. Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift to the south to southwest at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...KL/11 SHORT TERM...KL LONG TERM...11 AVIATION...KL/11 FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service Taunton MA 656 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build over New England tonight, and will then become centered southeast of New England during Tuesday. Heat and humidity will increase this week with the high remaining centered offshore, bringing a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... High pressure builds across the Eastern USA, including New England. A light flow region is in place, with most of the strongest winds found in sea breezes, which will shortly diminish. Satellite shows high-level cirrus across the region but settling southeast with clearing expected before midnight. Continue to expect mostly clear skies and light winds. This will encourage radiational cooling overnight which will allow temps to fall to near the dew point. Observed evening dew points are in the 50s with a few low 60s. Expect min temps in the mid 50s to low 60s. This will allow fog to form, especially in the usual fog- favored locations inland. There continues to be a low chance of some fog/low clouds along the southern coast of RI and MA as well. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Tuesday... The surface high becomes centered offshore during the day, while upper level ridge builds towards our area from the west. Southern New England gets into return low level SW flow which will begin to bring warmer and eventually more humid air into region. Mostly sunny skies expected, mainly from diurnal cumulus but could see a few higher deck clouds as well. Temperatures rise well into the 80s across much of the area. Exception will be along south coastal MA/RI, where highs in the 70s to near 80 are expected. Expecting an eventual sea breeze development along east coastal MA, but may take into midday/early afternoon to get going and overcome SW flow. Tuesday night... Surface high pressure centered offshore and light SW return flow continues. Upper ridge axis extends over New England. This will be a slightly warmer and more humid night, with lows in the 60s. Could see some patchy valley fog once more, otherwise mostly clear skies expected. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Big Picture... Longwave pattern shows steady heights through the week followed by building heights off the Atlantic Sunday and Monday. Shortwave scale shows an upper ridge with axis over New England Wednesday, shifting southeast Thursday and Friday. Shortwave over the Upper Midwest Wednesday moves into Eastern Canada and sweeps a weak shortwave across New England Friday night. Subtropical high over the Atlantic builds Sunday and Monday while another shortwave approaches from the west on Monday. General model agreement Wednesday to Friday, but uncertainty for Saturday and Sunday. Both show the Friday night cold front stalling to our south. Both the 12Z GFS and ECMWF show dry weather Saturday followed by a wave moving up the front spreading showers into our area Sunday. Earlier runs showed that wave moving past with wet weather Saturday followed by dry weather Sunday. All show high pressure and dry weather Monday. Low confidence as to which will be right for the weekend. We have chosen to compromise between the two camps for now and allow the next couple of runs provide clearer information. Details... Wednesday through Friday... High pressure offshore with a developing southwest flow over the region. This will bring in increasing dew points through the period. Temperatures aloft also increase with 850-equivilent temps 16-17C Wednesday increasing to 18-20C Thursday and Friday. Airmass also becomes increasingly unstable each day with LIs near zero in the CT Valley Wednesday but with limited cloud moisture, then sub-zero LIs across much of the area Thursday and at least part of Friday. Based on this, expect hot temps during this period with max temps either side of 90 Wednesday, and 90-95 Thursday and Friday. Dew points climb to around 70 by Friday morning so humidity levels will be at least noticeable and eventually oppressive. There is a small chance of a thunderstorm in far western MA Wednesday. Thunderstorms more likely Thursday afternoon through Friday. One concern...the GFS and EC both rush precipitation through on Friday morning, while maintaining southwest winds most areas until Friday evening. Perhaps this is focussing showers on a pre-frontal trough and keeping the main front dry. Temps aloft stay warm through the afternoon supporting the idea of a later cold fropa. We massaged the available grid data to keep chance pops into mid afternoon. Specific timing of convection is probably questionable this far out, with the important idea being that there will be precipitation during some part of Friday. Saturday-Sunday-Monday... Much uncertainty in the forecast and forecast data at this time. As noted above, the 12z GFS and EC show a low pressure wave passing us on Sunday with showers while much of the forecast grid data shows showers on Saturday and dry on Sunday. Previous model suites also went with wet weather on Saturday. We have hand-edited our database to show chance pops both days. Expect later model runs will resolve this timing to one day or the other. High pressure brings drier seasonable weather on Monday. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Tonight...High confidence. VFR with mostly clear skies. Local MVFR/IFR possible overnight in valley fog, as well as a possibility for patchy stratus/fog overnight along south coastal MA/southern RI. Tuesday and Tuesday night...High confidence. VFR, with local MVFR possible Tuesday night in valley fog. Prevailing S/SW winds Tue except sea breeze development expected along the shorelines. KBOS TAF...High confidence. VFR with light wind. Sea breeze should redevelop during Tuesday around midday. KBDL TAF...High confidence. VFR. Outlook /Wednesday through Saturday/... Wednesday through Friday... Moderate Confidence. VFR. Areas if late night/early morning IFR in fog. Scatterd MVFR/IFRin afternoon and evening showers/thunderstorms, mainly Thursday andFriday. Winds becoming southwest much of the period. Saturday... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England through tonight, and becomes centered offshore during Tuesday. Light and variable wind becomes prevailing SW later tonight and Tuesday, except for local sea breezes redeveloping on Tuesday. Outlook /Wednesday through Saturday/... Moderate confidence. Winds below 25 knots through the period. Seas mainly below 5 feet, although there is potential for brief 5 foot seas on the outer waters Thursday night and Friday. Winds becoming southwest for most of the period. Areas of poor visibility in overnight and morning fog. Scattered showers/thunderstorms mainly Thursday and Friday. Low confidence on showers for Saturday. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...WTB/NMB NEAR TERM...WTB/NMB SHORT TERM...NMB LONG TERM...WTB AVIATION...WTB/NMB MARINE...WTB/NMB
Area Forecast Discussion National Weather Service Albany NY 630 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 630 PM EDT...Patchy high clouds continue to stream across portions of the region, especially from around I-90 southward. This may be at least in part in association with a jet max retreating off the New England coast, with our area within its right entrance region. This jet max is expected to translate farther off the coast this evening, and should allow its influence and associated high clouds to decrease. So, partly cloudy this evening, then becoming mostly clear overnight. Some patchy fog will likely develop in river valleys, given that mixing was not very strong/deep this afternoon, and afternoon dewpoints held in the 50s. It will be cool once again tonight, with low temperatures before daybreak falling into the 50s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. Satellite imagery reveals few-sct cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift from the southerly direction at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...KL/11 SHORT TERM...KL LONG TERM...11 AVIATION...KL/BGM/JPV FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service New York NY 610 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Skies will clear out tonight. With increasing low level moisture and light winds, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior portions of the CWA will drop into the upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. There is a moderate risk of rip current development at the Atlantic facing beaches on Tuesday. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /22Z MONDAY THROUGH SATURDAY/... Seabreeze finally making steady progress north and should pass through KLGA, KEWR, and KTEB in the next hour, possibly two hours. Otherwise, high pressure builds over the terminals through the overnight. Fair weather cumulus with bases around 4000-5000 ft will diminish by early this evening VFR overnight with light winds. Perhaps some MVFR VIS in BR at rural airports towards sunrise. VFR continues for Tuesday with southerly flow. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component FCSTS can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments expected. KLGA TAF Comments: High confidence of seabreeze passage by 00Z. KEWR TAF Comments: High confidence of seabreeze passage by 00Z. KTEB TAF Comments: Moderate to high confidence of seabreeze passage by 00Z. KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 18Z Tuesday through Saturday... .Tue AFTN-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the Morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...MPS SHORT TERM...MPS LONG TERM...JC AVIATION...Tongue/DW MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service Albany NY 421 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 410 PM EDT, patchy high clouds continue to stream across portions of the region, especially from around I-90 southward. This may be at least in part in association with a jet max retreating off the New England coast, with our area within its right entrance region. This jet max is expected to translate farther off the coast this evening, and should allow its influence and associated high clouds to decrease. So, partly cloudy this evening, then becoming mostly clear overnight. Some patchy fog will likely develop in river valleys, given that mixing was not very strong/deep this afternoon, and afternoon dewpoints held in the 50s. It will be cool once again tonight, with low temperatures before daybreak falling into the 50s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. Satellite imagery reveals few-sct cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift from the southerly direction at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...KL SHORT TERM...KL LONG TERM...11 AVIATION...KL/BGM/JPV FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service Taunton MA 403 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build over New England tonight, and will then become centered southeast of New England during Tuesday. Heat and humidity will increase this week with the high remaining centered offshore, bringing a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 4 PM Update... Surface high pressure continues to move across our area this evening and overnight. Lingering patchy diurnal cumulus dissipate leaving mostly clear skies with some cirrus. The light to calm winds, mainly clear skies, and dry airmass will help lows fall back into the mid and upper 50s inland and to the lower 60s near the coast. There may be some patchy valley fog inland, and there is a low chance of some patchy fog/stratus along south coastal MA and southern RI. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Tuesday... The surface high becomes centered offshore during the day, while upper level ridge builds towards our area from the west. Southern New England gets into return low level SW flow which will begin to bring warmer and eventually more humid air into region. Mostly sunny skies expected, mainly from diurnal cumulus but could see a few higher deck clouds as well. Temperatures rise well into the 80s across much of the area. Exception will be along south coastal MA/RI, where highs in the 70s to near 80 are expected. Expecting an eventual sea breeze development along east coastal MA, but may take into midday/early afternoon to get going and overcome SW flow. Tuesday night... Surface high pressure centered offshore and light SW return flow continues. Upper ridge axis extends over New England. This will be a slightly warmer and more humid night, with lows in the 60s. Could see some patchy valley fog once more, otherwise mostly clear skies expected. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Big Picture... Longwave pattern shows steady heights through the week followed by building heights off the Atlantic Sunday and Monday. Shortwave scale shows an upper ridge with axis over New England Wednesday, shifting southeast Thursday and Friday. Shortwave over the Upper Midwest Wednesday moves into Eastern Canada and sweeps a weak shortwave across New England Friday night. Subtropical high over the Atlantic builds Sunday and Monday while another shortwave approaches from the west on Monday. General model agreement Wednesday to Friday, but uncertainty for Saturday and Sunday. Both show the Friday night cold front stalling to our south. Both the 12Z GFS and ECMWF show dry weather Saturday followed by a wave moving up the front spreading showers into our area Sunday. Earlier runs showed that wave moving past with wet weather Saturday followed by dry weather Sunday. All show high pressure and dry weather Monday. Low confidence as to which will be right for the weekend. We have chosen to compromise between the two camps for now and allow the next couple of runs provide clearer information. Details... Wednesday through Friday... High pressure offshore with a developing southwest flow over the region. This will bring in increasing dew points through the period. Temperatures aloft also increase with 850-equivilent temps 16-17C Wednesday increasing to 18-20C Thursday and Friday. Airmass also becomes increasingly unstable each day with LIs near zero in the CT Valley Wednesday but with limited cloud moisture, then sub-zero LIs across much of the area Thursday and at least part of Friday. Based on this, expect hot temps during this period with max temps either side of 90 Wednesday, and 90-95 Thursday and Friday. Dew points climb to around 70 by Friday morning so humidity levels will be at least noticeable and eventually oppressive. There is a small chance of a thunderstorm in far western MA Wednesday. Thunderstorms more likely Thursday afternoon through Friday. One concern...the GFS and EC both rush precipitation through on Friday morning, while maintaining southwest winds most areas until Friday evening. Perhaps this is focussing showers on a pre-frontal trough and keeping the main front dry. Temps aloft stay warm through the afternoon supporting the idea of a later cold fropa. We massaged the available grid data to keep chance pops into mid afternoon. Specific timing of convection is probably questionable this far out, with the important idea being that there will be precipitation during some part of Friday. Saturday-Sunday-Monday... Much uncertainty in the forecast and forecast data at this time. As noted above, the 12z GFS and EC show a low pressure wave passing us on Sunday with showers while much of the forecast grid data shows showers on Saturday and dry on Sunday. Previous model suites also went with wet weather on Saturday. We have hand-edited our database to show chance pops both days. Expect later model runs will resolve this timing to one day or the other. High pressure brings drier seasonable weather on Monday. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 20Z Update... This evening...High confidence. VFR conditions expected through this evening. Overall winds light and variable across the interior. East coastal MA sea breeze lingers thru early evening. Potential for a south coastal MA/RI sea breeze developing briefly late today. Overnight...High confidence. VFR, but local MVFR/IFR possible tonight in valley fog, as well as a possibility for patchy stratus/fog overnight along south coastal MA/southern RI. Tuesday and Tuesday night...High confidence. VFR, with local MVFR possible Tuesday night in valley fog. Prevailing S/SW winds Tue except sea breeze development expected along the shorelines. KBOS TAF...High confidence. VFR. Weak seabreeze lingers into early this evening. Sea breeze should redevelop during Tuesday around midday. KBDL TAF...High confidence. VFR. Outlook /Wednesday through Saturday/... Wednesday through Friday... Moderate Confidence. VFR. Areas if late night/early morning IFR in fog. Scatterd MVFR/IFRin afternoon and evening showers/thunderstorms, mainly Thursday andFriday. Winds becoming southwest much of the period. Saturday... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England through tonight, and becomes centered offshore during Tuesday. Light and variable wind becomes prevailing SW later tonight and Tuesday, except for local sea breezes redeveloping on Tuesday. Outlook /Wednesday through Saturday/... Moderate confidence. Winds below 25 knots through the period. Seas mainly below 5 feet, although there is potential for brief 5 foot seas on the outer waters Thursday night and Friday. Winds becoming southwest for most of the period. Areas of poor visibility in overnight and morning fog. Scattered showers/thunderstorms mainly Thursday and Friday. Low confidence on showers for Saturday. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...WTB/NMB NEAR TERM...NMB SHORT TERM...NMB LONG TERM...WTB AVIATION...WTB/NMB MARINE...WTB/NMB
Area Forecast Discussion National Weather Service New York NY 357 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Skies will clear out tonight. With increasing low level moisture and light winds, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior portions of the CWA will drop into the upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... High pressure builds over the terminals through the overnight. Fair weather cumulus with bases around 4500 ft will diminish by late AFTN (22Z). Northerly winds will eventually shift around to S late this AFTN into the evening as sea breezes move inland from the Atlantic and CT coasts. VFR overnight with light winds. Perhaps some MVFR VIS in BR at rural airports towards sunrise. VFR continues for Tuesday with southern flow. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component FCSTS can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: Sea Breeze has moved south of the airport causing a wind shift to the northeast. SFC winds eventually become south...but there is low confidence in the timing of this. It could be as late as 00Z. KLGA TAF Comments: No long expect the seabreeze to reach the field this evening. KEWR TAF Comments: A lot of variability in direction the rest of the AFTN. With the Sea Breeze having dissipated...winds should stay more NE into the evening. KTEB TAF Comments: No unscheduled amendments expected KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 18Z Tuesday through Saturday... .Tue AFTN-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly AFTN TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the Morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...MPS SHORT TERM...MPS LONG TERM...JC AVIATION...Tongue MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service Taunton MA 354 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build over New England tonight, and will then become centered southeast of New England during Tuesday. Heat and humidity will increase this week with the high remaining centered offshore, bringing a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 4 PM Update... Surface high pressure continues to move across our area this evening and overnight. Lingering patchy diurnal cumulus dissipate leaving mostly clear skies with some cirrus. The light to calm winds, mainly clear skies, and dry airmass will help lows fall back into the mid and upper 50s inland and to the lower 60s near the coast. There may be some patchy valley fog inland, and there is a low chance of some patchy fog/stratus along south coastal MA and southern RI. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Tuesday... The surface high becomes centered offshore during the day, while upper level ridge builds towards our area from the west. Southern New England gets into return low level SW flow which will begin to bring warmer and eventually more humid air into region. Mostly sunny skies expected, mainly from diurnal cumulus but could see a few higher deck clouds as well. Temperatures rise well into the 80s across much of the area. Exception will be along south coastal MA/RI, where highs in the 70s to near 80 are expected. Expecting an eventual sea breeze development along east coastal MA, but may take into midday/early afternoon to get going and overcome SW flow. Tuesday night... Surface high pressure centered offshore and light SW return flow continues. Upper ridge axis extends over New England. This will be a slightly warmer and more humid night, with lows in the 60s. Could see some patchy valley fog once more, otherwise mostly clear skies expected. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Highlights... * Becoming hot and humid late in the week. * Scattered thunderstorms will likely affect the region late Thu and Fri. * Low confidence forecast for the weekend. May have more showers on Sat. OVERALL PICTURE... Upper flow across North America becomes more zonal for a time this coming week. Fairly high confidence of hot temperatures and increasing humidity for the middle and latter part of the week. Have a risk of approaching Heat Advisory criteria on Thursday if dewpoints reach at least 70. Shortwave trof rotating about Hudson Bay vortex and associated surface front approaches southern New England Thursday night. The timing of this feature will be critical as to threat of strong to severe thunderstorms. Model consensus would seem to suggest that the front may pass through southern New England Friday morning or early afternoon, not diurnally optimal for convection. Confidence is relatively low for the weekend. May not be as dry as originally thought since flow aloft remains cyclonic and from the WSW or SW. Also, both the 00Z GFS and ECMWF operational runs suggest a frontal wave on Saturday. DETAILS... Wed...Temperatures will likely reach mid 80s to lower 90s. Cannot rule out isolated thunderstorm over the western higher terrain areas but expect that most, if not all, of region remains dry. Thu...Operational models have ensemble support for a hot/humid day. H850 temperatures will likely rise to at least around 18C and will likely see all but the south coast and highest terrain areas reach 90 to 95. Sufficient instability may exist for scattered pulse late afternoon/evening thunderstorms in the western zones. As the surface front or prefrontal trough approaches, convection may persist into the night for a time across the western zones. Fri...Upper short wave trof and associated surface front crosses the region. Timing is critical with regard to convective potential. Model consensus for now would seem to have the frontal boundary making it to the coast by midday or early afternoon, too soon to tap into diurnal heating. However, Friday is still 5 days away and so cannot be all that confident on timing details. There looks to be sufficient bulk shear to support organized storms if the instability is sufficient. Expect max temperatures to be a few degrees lower than Thursday due to increased cloudiness. Nevertheless, many locations are expected to reach into the lower 90s with dewpoints in the upper 60s to near 70. Next weekend...Confidence is relatively low at this time regarding next Saturday and Sunday. Both the GFS and ECMWF operational runs depict the broad upper trof axis to be west of the area and even hint at a frontal wave passing through or just SE of the area on Saturday. Have raised POPs and sky cover some for Saturday as a consequence. Also, lowered temperatures along the coastal plain a tad as well due to potential for more clouds and possibly onshore flow. If a surface wave forms more as per the GFS, then temperatures would likely be cooler and rainfall steadier. On the other hand, the ECMWF might keep some of southern New England in the warm sector and more convectively active. It is just too soon to be able to nail down specifics this far out. Have opted for POPs below chance for Sunday as looks for now that drier air should infiltrate the region from the west. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 20Z Update... This evening...High confidence. VFR conditions expected through this evening. Overall winds light and variable across the interior. East coastal MA sea breeze lingers thru early evening. Potential for a south coastal MA/RI sea breeze developing briefly late today. Overnight...High confidence. VFR, but local MVFR/IFR possible tonight in valley fog, as well as a possibility for patchy stratus/fog overnight along south coastal MA/southern RI. Tuesday and Tuesday night...High confidence. VFR, with local MVFR possible Tuesday night in valley fog. Prevailing S/SW winds Tue except sea breeze development expected along the shorelines. KBOS TAF...High confidence. VFR. Weak seabreeze lingers into early this evening. Sea breeze should redevelop during Tuesday around midday. KBDL TAF...High confidence. VFR. Outlook /Wednesday through Saturday/...High confidence. Wednesday through Thursday morning...Generally VFR except areas of MVFR/IFR in fog along the south coast. Thursday afternoon through Friday...Generally VFR but areas of MVFR cigs/vsbys in vicinity of scattered showers and thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England through tonight, and becomes centered offshore during Tuesday. Light and variable wind becomes prevailing SW later tonight and Tuesday, except for local sea breezes redeveloping on Tuesday. Outlook /Wednesday through Saturday/...High confidence. Relatively light wind fields are expected and seas should generally remain below 5 feet across all waters. There will be areas of late night and early morning fog, especially along the south coastal waters during this time period. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...NMB/JWD/Thompson NEAR TERM...NMB SHORT TERM...NMB LONG TERM...Thompson AVIATION...NMB/JWD/Thompson MARINE...NMB/JWD/Thompson
Area Forecast Discussion National Weather Service New York NY 330 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Skies will clear out tonight. With increasing low level moisture and light winds, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior portions of the CWA will drop into the upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... High pressure builds over the terminals through the overnight. Fair weather cumulus with bases around 4500 ft will diminish by late AFTN (22Z). Northerly winds will shift around to S this AFTN as sea breezes move inland from the Atlantic and CT coasts. VFR overnight with light winds. Perhaps some MVFR VIS in BR at rural airports towards sunrise. VFR continues for Tuesday with southern flow. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component FCSTS can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: High confidence in SFC winds becoming solidly south as the Sea Breeze works inland. KLGA TAF Comments: Wind shift from Sea Breeze could be as late as 00Z. KEWR TAF Comments: A lot of variability in direction the rest of the AFTN. High confidence in speeds of less than 10 KT as direction settles to SE by 22-23Z. KTEB TAF Comments: No unscheduled amendments expected KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 18Z Tuesday through Saturday... .Tue AFTN-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly AFTN TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the Morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...MPS SHORT TERM...MPS LONG TERM...JC AVIATION...Tongue MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service Taunton MA 216 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build over New England today, resulting in clearing skies and more seasonable temperatures. Heat and humidity will increase this week as the high becomes centered offshore and brings a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 215 PM Update... Surface high pressure continues to build over our area this afternoon, and low level moisture has been more steadily eroding. The lower clouds have been clearing from north to south between noon and 2 pm, leaving partly sunny skies across northern and central MA. Mostly cloudy skies remained across northern CT and southeast MA, due to the parting stratocumulus deck as well as a cirrus deck passing thru the area. Expect to see a continued decrease in clouds across southern New England during the remainder of this afternoon. Some locales across northern MA and the Connecticut River Valley in MA/CT will manage to warm into the upper 70s and low 80s. Elsewhere across the region thinking temps will max out in the low to mid 70s due to the later thinning of the cloud deck, and the sea breeze along east coastal MA and developing sea breeze along the south coast. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... High pressure builds over southern New England tonight. Light winds, clear skies, and a dry airmass will help lows fall back into the 50s inland (where we may see some patchy valley fog) and to the lower 60s near coast. As the high becomes centered offshore Tuesday, we get into return SW flow which will begin to bring warmer (and eventually more humid) air into region. Highs will top out well into 80s (except 70s near South Coast) if not around 90 in parts of CT and Merrimack Valleys. Some of the models (00z GFS and 21z SREF in particular) try to bring showers/storms into southern New England Tue afternoon, as moisture is drawn up from the mid Atlantic states and interacts with a weak surface trough. We are not buying into this wetter solution given axis of 500 mb ridge to our W with larger scale subsidence present over region. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Highlights... * Becoming hot and humid late in the week. * Scattered thunderstorms will likely affect the region late Thu and Fri. * Low confidence forecast for the weekend. May have more showers on Sat. OVERALL PICTURE... Upper flow across North America becomes more zonal for a time this coming week. Fairly high confidence of hot temperatures and increasing humidity for the middle and latter part of the week. Have a risk of approaching Heat Advisory criteria on Thursday if dewpoints reach at least 70. Shortwave trof rotating about Hudson Bay vortex and associated surface front approaches southern New England Thursday night. The timing of this feature will be critical as to threat of strong to severe thunderstorms. Model consensus would seem to suggest that the front may pass through southern New England Friday morning or early afternoon, not diurnally optimal for convection. Confidence is relatively low for the weekend. May not be as dry as originally thought since flow aloft remains cyclonic and from the WSW or SW. Also, both the 00Z GFS and ECMWF operational runs suggest a frontal wave on Saturday. DETAILS... Wed...Temperatures will likely reach mid 80s to lower 90s. Cannot rule out isolated thunderstorm over the western higher terrain areas but expect that most, if not all, of region remains dry. Thu...Operational models have ensemble support for a hot/humid day. H850 temperatures will likely rise to at least around 18C and will likely see all but the south coast and highest terrain areas reach 90 to 95. Sufficient instability may exist for scattered pulse late afternoon/evening thunderstorms in the western zones. As the surface front or prefrontal trough approaches, convection may persist into the night for a time across the western zones. Fri...Upper short wave trof and associated surface front crosses the region. Timing is critical with regard to convective potential. Model consensus for now would seem to have the frontal boundary making it to the coast by midday or early afternoon, too soon to tap into diurnal heating. However, Friday is still 5 days away and so cannot be all that confident on timing details. There looks to be sufficient bulk shear to support organized storms if the instability is sufficient. Expect max temperatures to be a few degrees lower than Thursday due to increased cloudiness. Nevertheless, many locations are expected to reach into the lower 90s with dewpoints in the upper 60s to near 70. Next weekend...Confidence is relatively low at this time regarding next Saturday and Sunday. Both the GFS and ECMWF operational runs depict the broad upper trof axis to be west of the area and even hint at a frontal wave passing through or just SE of the area on Saturday. Have raised POPs and sky cover some for Saturday as a consequence. Also, lowered temperatures along the coastal plain a tad as well due to potential for more clouds and possibly onshore flow. If a surface wave forms more as per the GFS, then temperatures would likely be cooler and rainfall steadier. On the other hand, the ECMWF might keep some of southern New England in the warm sector and more convectively active. It is just too soon to be able to nail down specifics this far out. Have opted for POPs below chance for Sunday as looks for now that drier air should infiltrate the region from the west. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 18Z TAF Update... This afternoon/evening...Moderate confidence. MVFR cigs lingering along southern RI and far southeast MA expected to improve to VFR by 20Z. Otherwise, high confidence VFR for the remainder of this afternoon and evening as ceilings lift and clouds decrease in coverage. N winds will be quite light this afternoon, in some cases light and variable. East coastal MA sea breeze lingers thru the remainder of today, with a south coastal MA/RI sea breeze developing thru 21Z. Overnight...High confidence. VFR, but local MVFR/IFR possible tonight in valley fog, as well as possibility for patchy stratus/fog overnight along south coastal MA/southern RI. Tuesday and Tuesday night...High confidence. VFR, with local MVFR possible Tuesday night in valley fog. Prevailing S/SW winds Tue except sea breeze development expected along the shorelines. KBOS TAF...High confidence. VFR. Weak seabreeze thru the remainder of today. Sea breeze should redevelop during Tuesday around midday. KBDL TAF...High confidence. VFR. Outlook /Wednesday through Friday/...High confidence. Wednesday through Thursday morning...Generally VFR except areas of MVFR/IFR in fog along the south coast. Thursday afternoon through Friday...Generally VFR but areas of MVFR cigs/vsbys in vicinity of scattered showers and thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England today. Light N/NE flow except for local sea breezes lingering into this evening. SW flow gets underway Tue as high becomes centered offshore. Outlook /Tuesday Night through Friday/...High confidence. Relatively light wind fields are expected and seas should generally remain below 5 feet across all waters. There will be areas of late night and early morning fog, especially along the south coastal waters during this time period. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...JWD/Thompson NEAR TERM...NMB/JWD/Thompson SHORT TERM...JWD LONG TERM...Thompson AVIATION...NMB/JWD/Thompson MARINE...NMB/JWD/Thompson
Area Forecast Discussion National Weather Service New York NY 207 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure settles over the region today and moves offshore Tuesday into Wednesday. A slow moving cold front will approach from Wednesday night into Thursday, then pass east on Friday. Another frontal system may pass through on Saturday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... High pressure continues to build in from the west. Clouds associated with a weak mid-level shortwave will also continue to erode going through the afternoon as heights aloft increase and the shortwave departs. Generally partly to mostly sunny skies for the rest of the afternoon. With weak flow, afternoon sea breezes will develop near the coast and slowly push inland. Sea breezes may struggle to make it into NE NJ and the Lower Hudson Valley. High temperatures will be in the upper 70s to the lower 80s. Coolest conditions near the immediate coast and across eastern Long Island and southeast Connecticut where more cloud cover will reside. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... Tranquil conditions and mostly clear skies are expected tonight as the surface high and building ridging aloft dominate. The high will move offshore on Tuesday, but the ridge axis will still be located to the west of the region. Warmer air begins to move around the offshore high with 850 HPA temperatures increasing 2C to 4C from Monday. However, increasing southerly flow off the Atlantic around the offshore high will likely allow temperatures to only warm to near normal levels for this time of year. Highs in the middle 80s are forecast away from the coast, with readings closer to 80 near the coast due to the onshore flow. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... High pressure at the surface will slowly pass off the Mid Atlantic coast Tue night. Models show some moisture return on the back side of the sfc high, perhaps a weak shortwave trough moving through the mean upper ridge which will also be passing to the east at that time. GFS likely too aggressive with moisture return and lift, and sided toward drier ECMWF/NAM ideas, with only isolated PoP from NYC west late day Wed into Wed night. A broad upper trough will then become established from the northern Plains to the Northeast later this week. A surface cold front will still be well to the NW on Thu, but expect scattered showers/tstms to develop inland Thu afternoon invof a pre-frontal trough as a mid level shortwave approaches, drifting toward the coast late day and at night. With very warm/moist low levels, S low level flow and NW flow aloft, would expect some potential for severe wx, but coverage could ultimately be limited by a mid level capping inversion if the 00Z GFs is correct. The cold front will slowly approach on Friday, with only slight chance PoP at most as deeper moisture will be shunted to the east. Fri could be the hottest day of the week, with lower/mid 90s except at south facing coastlines, and potential for the heat index to touch 100 in urban NE NJ. This front should move east by evening, then latest model/ensemble guidance indicates potential for another frontal system to quickly follow for Sat. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... High pressure builds over the terminals this AFTN. Fair weather cumulus with bases around 4500 ft will diminish by late AFTN (21Z). Northerly winds will shift around to S this AFTN as sea breezes develop. VFR overnight with perhaps some MVFR VIS in BR at rural airports towards sunrise and light winds. VFR continues for Tuesday with southern flow. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component fcsts can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: High confidence in southerly SFC wind for INTL departure bank. KLGA TAF Comments: Wind shift from Sea Breeze could be as late as 21Z. KEWR TAF Comments: High confidence in SE winds for this AFTN at less than 10 KT. KTEB TAF Comments: No unscheduled amendments expected KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 18Z Tuesday through Saturday... .Tue AFTN-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly AFTN TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the Morning. .Sat...VFR. && .MARINE... High pressure settles over the waters through the middle of the week with a cold front approaching late in the week. Winds and seas will remain below SCA levels through the period. && .HYDROLOGY... No significant widespread precipitation expected through the middle of the week. Locally heavy rainfall is possible in any thunderstorms that develop on Thursday, possibly also on Saturday. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...Goodman/DS NEAR TERM...MPS SHORT TERM...DS LONG TERM...Goodman AVIATION...Tongue MARINE...Goodman/DS HYDROLOGY...Goodman/DS
Area Forecast Discussion National Weather Service Albany NY 133 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system for mid week. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1230 PM EDT, the combination of high clouds, and some lingering lower clouds has kept skies partly to mostly cloudy across the SE Catskills, mid Hudson Valley region and NW CT. Skies have become mostly sunny further N and W. We expect the overall trend for sky cover to become mostly sunny across the region by mid to late afternoon. Temperatures should continue rising, reaching highs of around 80 in many valley areas by 5 or 6 PM, with 70s for most higher terrain. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Heat and humidity return. Ridging will continue to build in. The surface high will begin to shift offshore on Tuesday with a southerly return flow developing. Aloft the ridge axis is forecast to crest over the region late Tuesday night/Wednesday morning with the axis shifting off the seaboard during the day. In the meantime, a stacked low pressure system will be on the gradual approach. Deep southwest flow will develop between the departing ridge and the approaching trough. Heat and humidity will be in the rise and will be very noticeably on Wednesday. 850 mb temperatures are forecast to rise to 16 to 18 degrees Celsius on Wednesday. Highs Tuesday are expected to be in the upper 70s to upper 80s with dew points rising into the upper 50s to mid 60s. Dew points will continue to rise Tuesday night into Wednesday with widespread mid to upper 60s anticipated. These values combined with high temperatures expected to top out in mainly on the 80s to lower 90s with result in heat indices in the upper 80s to upper 90s. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. As the atmosphere warms up and becomes increasingly more humid and unstable the threat of convection will be in the rise. With only subtle height fall expected Wednesday and upper level support remaining well to the west have slight chance pops across the local area for the afternoon hours. However, the chances for convection will continue Wednesday night as the upper trough and low pressure system`s cold front move into the Great Lakes region. Better chances will be west of the Hudson River Valley. The Storm Prediction Center has the region under a general thunderstorm outlook. Storms will be capable of locally heavy rainfall as precipitable water values are forecast to rise to 1.5+ inches. && .LONG TERM /THURSDAY THROUGH MONDAY/... The period starts out on Thursday with our region still under the influence of a very warm and moist southerly flow. It will become increasingly humid, with models indicating a pre-frontal trough moving through at some point during the afternoon or evening. This trough is expected to result in scattered showers and thunderstorms. Some of the storms could be on the stronger side depending on the eventual magnitude of instability and deep layer shear. Given the anticipated above normal PWATS of +1 to +2 STDEV, heavy rainfall is likely to occur within any persistent thunderstorms. Another rather subtle boundary may move across the region on Friday, with more mainly diurnal showers and thunderstorms. Models are showing a weaker system now compared to Thursday, but with the continued warm and humid air mass in place, scattered convection looks reasonable again. It will likely remain very warm and muggy Friday. Some of the 00Z model guidance showing a wave of low pressure developing along a fairly flat and progressive upper level trough for Saturday. Some GEFS ensemble members also depicting this potential wave with some probabilities for precip as well, so will raise pops to 30 percent to account for this possibility. This potential system should exit the region by Sunday with drier weather to close out the weekend. Overall, temperatures look to "cool" closer to normal values during the upcoming weekend, with somewhat of a reprieve in humidity levels as well. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. Satellite imagery reveals few-sct cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift from the southerly direction at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 80 to near 100 percent tonight. Minimum values Tuesday afternoon are forecast to be generally 40 to 50 percent south of Interstate 90 and 35 to 45 percent north of Interstate 90. Light northerly winds today will diminish tonight with a southerly flow developing Tuesday at generally less than 10 mph. && .HYDROLOGY... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/KL/BGM SHORT TERM...IAA LONG TERM...JPV AVIATION...BGM/JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service Albany NY 133 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system for mid week. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1230 PM EDT, the combination of high clouds, and some lingering lower clouds has kept skies partly to mostly cloudy across the SE Catskills, mid Hudson Valley region and NW CT. Skies have become mostly sunny further N and W. We expect the overall trend for sky cover to become mostly sunny across the region by mid to late afternoon. Temperatures should continue rising, reaching highs of around 80 in many valley areas by 5 or 6 PM, with 70s for most higher terrain. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Heat and humidity return. Ridging will continue to build in. The surface high will begin to shift offshore on Tuesday with a southerly return flow developing. Aloft the ridge axis is forecast to crest over the region late Tuesday night/Wednesday morning with the axis shifting off the seaboard during the day. In the meantime, a stacked low pressure system will be on the gradual approach. Deep southwest flow will develop between the departing ridge and the approaching trough. Heat and humidity will be in the rise and will be very noticeably on Wednesday. 850 mb temperatures are forecast to rise to 16 to 18 degrees Celsius on Wednesday. Highs Tuesday are expected to be in the upper 70s to upper 80s with dew points rising into the upper 50s to mid 60s. Dew points will continue to rise Tuesday night into Wednesday with widespread mid to upper 60s anticipated. These values combined with high temperatures expected to top out in mainly on the 80s to lower 90s with result in heat indices in the upper 80s to upper 90s. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. As the atmosphere warms up and becomes increasingly more humid and unstable the threat of convection will be in the rise. With only subtle height fall expected Wednesday and upper level support remaining well to the west have slight chance pops across the local area for the afternoon hours. However, the chances for convection will continue Wednesday night as the upper trough and low pressure system`s cold front move into the Great Lakes region. Better chances will be west of the Hudson River Valley. The Storm Prediction Center has the region under a general thunderstorm outlook. Storms will be capable of locally heavy rainfall as precipitable water values are forecast to rise to 1.5+ inches. && .LONG TERM /THURSDAY THROUGH MONDAY/... The period starts out on Thursday with our region still under the influence of a very warm and moist southerly flow. It will become increasingly humid, with models indicating a pre-frontal trough moving through at some point during the afternoon or evening. This trough is expected to result in scattered showers and thunderstorms. Some of the storms could be on the stronger side depending on the eventual magnitude of instability and deep layer shear. Given the anticipated above normal PWATS of +1 to +2 STDEV, heavy rainfall is likely to occur within any persistent thunderstorms. Another rather subtle boundary may move across the region on Friday, with more mainly diurnal showers and thunderstorms. Models are showing a weaker system now compared to Thursday, but with the continued warm and humid air mass in place, scattered convection looks reasonable again. It will likely remain very warm and muggy Friday. Some of the 00Z model guidance showing a wave of low pressure developing along a fairly flat and progressive upper level trough for Saturday. Some GEFS ensemble members also depicting this potential wave with some probabilities for precip as well, so will raise pops to 30 percent to account for this possibility. This potential system should exit the region by Sunday with drier weather to close out the weekend. Overall, temperatures look to "cool" closer to normal values during the upcoming weekend, with somewhat of a reprieve in humidity levels as well. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. Satellite imagery reveals few-sct cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift from the southerly direction at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 80 to near 100 percent tonight. Minimum values Tuesday afternoon are forecast to be generally 40 to 50 percent south of Interstate 90 and 35 to 45 percent north of Interstate 90. Light northerly winds today will diminish tonight with a southerly flow developing Tuesday at generally less than 10 mph. && .HYDROLOGY... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/KL/BGM SHORT TERM...IAA LONG TERM...JPV AVIATION...BGM/JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service New York NY 1244 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure settles over the region today and moves offshore Tuesday into Wednesday. A slow moving cold front will approach from Wednesday night into Thursday, then pass east on Friday. Another frontal system may pass through on Saturday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... High pressure continues to build in from the west. Clouds associated with a weak mid-level shortwave will also continue to erode going through the afternoon as heights aloft increase and the shortwave departs. Generally partly to mostly sunny skies for the rest of the afternoon. With weak flow, afternoon sea breezes will develop near the coast and slowly push inland. Sea breezes may struggle to make it into NE NJ and the Lower Hudson Valley. High temperatures will be in the upper 70s to the lower 80s. Coolest conditions near the immediate coast and across eastern Long Island and southeast Connecticut where more cloud cover will reside. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... Tranquil conditions and mostly clear skies are expected tonight as the surface high and building ridging aloft dominate. The high will move offshore on Tuesday, but the ridge axis will still be located to the west of the region. Warmer air begins to move around the offshore high with 850 HPA temperatures increasing 2C to 4C from Monday. However, increasing southerly flow off the Atlantic around the offshore high will likely allow temperatures to only warm to near normal levels for this time of year. Highs in the middle 80s are forecast away from the coast, with readings closer to 80 near the coast due to the onshore flow. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... High pressure at the surface will slowly pass off the Mid Atlantic coast Tue night. Models show some moisture return on the back side of the sfc high, perhaps a weak shortwave trough moving through the mean upper ridge which will also be passing to the east at that time. GFS likely too aggressive with moisture return and lift, and sided toward drier ECMWF/NAM ideas, with only isolated PoP from NYC west late day Wed into Wed night. A broad upper trough will then become established from the northern Plains to the Northeast later this week. A surface cold front will still be well to the NW on Thu, but expect scattered showers/tstms to develop inland Thu afternoon invof a pre-frontal trough as a mid level shortwave approaches, drifting toward the coast late day and at night. With very warm/moist low levels, S low level flow and NW flow aloft, would expect some potential for severe wx, but coverage could ultimately be limited by a mid level capping inversion if the 00Z GFs is correct. The cold front will slowly approach on Friday, with only slight chance PoP at most as deeper moisture will be shunted to the east. Fri could be the hottest day of the week, with lower/mid 90s except at south facing coastlines, and potential for the heat index to touch 100 in urban NE NJ. This front should move east by evening, then latest model/ensemble guidance indicates potential for another frontal system to quickly follow for Sat. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... High pressure builds over the terminals this AFTN. Fair weather cumulus with bases around 4000 ft will diminish by late AFTN (21Z). Northerly winds will shift around to S-SE this AFTN as sea breezes develop. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component fcsts can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: High confidence in southerly SFC wind for INTL departure bank. KLGA TAF Comments: Wind shift from Sea Breeze could be an hour or so sooner than FCST. KEWR TAF Comments: Wind shift to SE may occur +/- an hour so of FCST. The afternoon KEWR haze potential forecast is green...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 14Z Tuesday through Friday... .Tue-Wed...VFR. .Thu-Fri...Scattered to isolated AFTN showers/tstms possible with local MVFR conds. && .MARINE... High pressure settles over the waters through the middle of the week with a cold front approaching late in the week. Winds and seas will remain below SCA levels through the period. && .HYDROLOGY... No significant widespread precipitation expected through the middle of the week. Locally heavy rainfall is possible in any thunderstorms that develop on Thursday, possibly also on Saturday. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...Goodman/DS NEAR TERM...MPS SHORT TERM...DS LONG TERM...Goodman AVIATION...Tongue MARINE...Goodman/DS HYDROLOGY...Goodman/DS
Area Forecast Discussion National Weather Service Albany NY 1238 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system for mid week. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1230 PM EDT, the combination of high clouds, and some lingering lower clouds has kept skies partly to mostly cloudy across the SE Catskills, mid Hudson Valley region and NW CT. Skies have become mostly sunny further N and W. We expect the overall trend for sky cover to become mostly sunny across the region by mid to late afternoon. Temperatures should continue rising, reaching highs of around 80 in many valley areas by 5 or 6 PM, with 70s for most higher terrain. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Heat and humidity return. Ridging will continue to build in. The surface high will begin to shift offshore on Tuesday with a southerly return flow developing. Aloft the ridge axis is forecast to crest over the region late Tuesday night/Wednesday morning with the axis shifting off the seaboard during the day. In the meantime, a stacked low pressure system will be on the gradual approach. Deep southwest flow will develop between the departing ridge and the approaching trough. Heat and humidity will be in the rise and will be very noticeably on Wednesday. 850 mb temperatures are forecast to rise to 16 to 18 degrees Celsius on Wednesday. Highs Tuesday are expected to be in the upper 70s to upper 80s with dew points rising into the upper 50s to mid 60s. Dew points will continue to rise Tuesday night into Wednesday with widespread mid to upper 60s anticipated. These values combined with high temperatures expected to top out in mainly on the 80s to lower 90s with result in heat indices in the upper 80s to upper 90s. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. As the atmosphere warms up and becomes increasingly more humid and unstable the threat of convection will be in the rise. With only subtle height fall expected Wednesday and upper level support remaining well to the west have slight chance pops across the local area for the afternoon hours. However, the chances for convection will continue Wednesday night as the upper trough and low pressure system`s cold front move into the Great Lakes region. Better chances will be west of the Hudson River Valley. The Storm Prediction Center has the region under a general thunderstorm outlook. Storms will be capable of locally heavy rainfall as precipitable water values are forecast to rise to 1.5+ inches. && .LONG TERM /THURSDAY THROUGH SUNDAY/... The period starts out on Thursday with our region still under the influence of a very warm and moist southerly flow. It will become increasingly humid, with models indicating a pre-frontal trough moving through at some point during the afternoon or evening. This trough is expected to result in scattered showers and thunderstorms. Some of the storms could be on the stronger side depending on the eventual magnitude of instability and deep layer shear. Given the anticipated above normal PWATS of +1 to +2 STDEV, heavy rainfall is likely to occur within any persistent thunderstorms. Another rather subtle boundary may move across the region on Friday, with more mainly diurnal showers and thunderstorms. Models are showing a weaker system now compared to Thursday, but with the continued warm and humid air mass in place, scattered convection looks reasonable again. It will likely remain very warm and muggy Friday. Some of the 00Z model guidance showing a wave of low pressure developing along a fairly flat and progressive upper level trough for Saturday. Some GEFS ensemble members also depicting this potential wave with some probabilities for precip as well, so will raise pops to 30 percent to account for this possibility. This potential system should exit the region by Sunday with drier weather to close out the weekend. Overall, temperatures look to "cool" closer to normal values during the upcoming weekend, with somewhat of a reprieve in humidity levels as well. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals today into tonight. Only scattered diurnal cumulus clouds will be around this afternoon with high pressure building in. Clear skies and light winds tonight will likely lead to some radiation fog at KGFL/KPSF after 06Z Tuesday. Occasional IFR conditions look probable. Potential fog development more uncertain at KALB/KPOU, so will leave out mention for now. Winds will be light and variable, becoming N-NW around 5 kt later this morning. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 80 to near 100 percent tonight. Minimum values Tuesday afternoon are forecast to be generally 40 to 50 percent south of Interstate 90 and 35 to 45 percent north of Interstate 90. Light northerly winds today will diminish tonight with a southerly flow developing Tuesday at generally less than 10 mph. && .HYDROLOGY... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/KL/BGM SHORT TERM...IAA LONG TERM...JPV AVIATION...JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service New York NY 1236 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure settles over the region today and moves offshore Tuesday into Wednesday. A slow moving cold front will approach from Wednesday night into Thursday, then pass east on Friday. Another frontal system may pass through on Saturday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Morning forecast on track. Will update hourly grids based on latest surface obs and satellite trends, but no significant changes will be made to the forecast. Otherwise...high pressure settles over the region today while a shortwave trough off the New England coast lifts into the Canadian Maritimes. Ridging aloft builds as heights rise. Lingering low level moisture across far southeastern Connecticut and eastern Long Island will be slow to erode with partly to mostly cloudy skies forecast into the early afternoon before some clearing takes place. The rest of the area will see partly to mostly sunny skies through the day. With weak flow, afternoon sea breezes will develop near the coast and slowly push inland. Sea breezes may struggle to make it into NE NJ and the Lower Hudson Valley. High temperatures will be in the upper 70s to the lower 80s. Coolest conditions near the immediate coast and across eastern Long Island and southeast Connecticut where more cloud cover will reside. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... Tranquil conditions and mostly clear skies are expected tonight as the surface high and building ridging aloft dominate. The high will move offshore on Tuesday, but the ridge axis will still be located to the west of the region. Warmer air begins to move around the offshore high with 850 HPA temperatures increasing 2C to 4C from Monday. However, increasing southerly flow off the Atlantic around the offshore high will likely allow temperatures to only warm to near normal levels for this time of year. Highs in the middle 80s are forecast away from the coast, with readings closer to 80 near the coast due to the onshore flow. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... High pressure at the surface will slowly pass off the Mid Atlantic coast Tue night. Models show some moisture return on the back side of the sfc high, perhaps a weak shortwave trough moving through the mean upper ridge which will also be passing to the east at that time. GFS likely too aggressive with moisture return and lift, and sided toward drier ECMWF/NAM ideas, with only isolated PoP from NYC west late day Wed into Wed night. A broad upper trough will then become established from the northern Plains to the Northeast later this week. A surface cold front will still be well to the NW on Thu, but expect scattered showers/tstms to develop inland Thu afternoon invof a pre-frontal trough as a mid level shortwave approaches, drifting toward the coast late day and at night. With very warm/moist low levels, S low level flow and NW flow aloft, would expect some potential for severe wx, but coverage could ultimately be limited by a mid level capping inversion if the 00Z GFs is correct. The cold front will slowly approach on Friday, with only slight chance PoP at most as deeper moisture will be shunted to the east. Fri could be the hottest day of the week, with lower/mid 90s except at south facing coastlines, and potential for the heat index to touch 100 in urban NE NJ. This front should move east by evening, then latest model/ensemble guidance indicates potential for another frontal system to quickly follow for Sat. && .AVIATION /16Z MONDAY THROUGH FRIDAY/... High pressure builds over the terminals this AFTN. Fair weather cumulus with bases around 4000 ft will diminish by late AFTN (21Z). Northerly winds will shift around to S-SE this AFTN as sea breezes develop. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component fcsts can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: High confidence in southerly SFC wind for INTL departure bank. KLGA TAF Comments: Wind shift from Sea Breeze could be an hour or so sooner than FCST. KEWR TAF Comments: Wind shift to SE may occur +/- an hour so of FCST. The afternoon KEWR haze potential forecast is green...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 14Z Tuesday through Friday... .Tue-Wed...VFR. .Thu-Fri...Scattered to isolated AFTN showers/tstms possible with local MVFR conds. && .MARINE... High pressure settles over the waters through the middle of the week with a cold front approaching late in the week. Winds and seas will remain below SCA levels through the period. && .HYDROLOGY... No significant widespread precipitation expected through the middle of the week. Locally heavy rainfall is possible in any thunderstorms that develop on Thursday, possibly also on Saturday. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...Goodman/DS NEAR TERM...MPS SHORT TERM...DS LONG TERM...Goodman AVIATION...Tongue MARINE...Goodman/DS HYDROLOGY...Goodman/DS
Area Forecast Discussion National Weather Service Albany NY 1025 AM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1020 AM...Low stratus has eroded rather quickly and being replaced by CU/SC with a canopy of higher CI/CS advecting across the entire region. While this may have slowed down the diurnal temperature climb a bit, expectations are for a partly-mostly sunny day with terrain based cumulus clouds. Per the 12Z sounding, rather stable exists up to H700 and per mixing layer heights, forecast highs look good with no changes needed at this time. Prev Disc... Heights will rise as ridging builds in at all levels of the atmosphere today. Have variable cloudy skies across the area as higher level clouds stream in from northwest and have some lingering stratus from overnight. Will have partly to mostly sunny skies today. Light northerly flow across the area with seasonable temperatures expected along with comfortable dew points mainly in the 50s. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Heat and humidity return. Ridging will continue to build in. The surface high will begin to shift offshore on Tuesday with a southerly return flow developing. Aloft the ridge axis is forecast to crest over the region late Tuesday night/Wednesday morning with the axis shifting off the seaboard during the day. In the meantime, a stacked low pressure system will be on the gradual approach. Deep southwest flow will develop between the departing ridge and the approaching trough. Heat and humidity will be in the rise and will be very noticeably on Wednesday. 850 mb temperatures are forecast to rise to 16 to 18 degrees Celsius on Wednesday. Highs Tuesday are expected to be in the upper 70s to upper 80s with dew points rising into the upper 50s to mid 60s. Dew points will continue to rise Tuesday night into Wednesday with widespread mid to upper 60s anticipated. These values combined with high temperatures expected to top out in mainly on the 80s to lower 90s with result in heat indices in the upper 80s to upper 90s. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. As the atmosphere warms up and becomes increasingly more humid and unstable the threat of convection will be in the rise. With only subtle height fall expected Wednesday and upper level support remaining well to the west have slight chance pops across the local area for the afternoon hours. However, the chances for convection will continue Wednesday night as the upper trough and low pressure system`s cold front move into the Great Lakes region. Better chances will be west of the Hudson River Valley. The Storm Prediction Center has the region under a general thunderstorm outlook. Storms will be capable of locally heavy rainfall as precipitable water values are forecast to rise to 1.5+ inches. && .LONG TERM /THURSDAY THROUGH SUNDAY/... The period starts out on Thursday with our region still under the influence of a very warm and moist southerly flow. It will become increasingly humid, with models indicating a pre-frontal trough moving through at some point during the afternoon or evening. This trough is expected to result in scattered showers and thunderstorms. Some of the storms could be on the stronger side depending on the eventual magnitude of instability and deep layer shear. Given the anticipated above normal PWATS of +1 to +2 STDEV, heavy rainfall is likely to occur within any persistent thunderstorms. Another rather subtle boundary may move across the region on Friday, with more mainly diurnal showers and thunderstorms. Models are showing a weaker system now compared to Thursday, but with the continued warm and humid air mass in place, scattered convection looks reasonable again. It will likely remain very warm and muggy Friday. Some of the 00Z model guidance showing a wave of low pressure developing along a fairly flat and progressive upper level trough for Saturday. Some GEFS ensemble members also depicting this potential wave with some probabilities for precip as well, so will raise pops to 30 percent to account for this possibility. This potential system should exit the region by Sunday with drier weather to close out the weekend. Overall, temperatures look to "cool" closer to normal values during the upcoming weekend, with somewhat of a reprieve in humidity levels as well. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... VFR conditions expected across the terminals today into tonight. Only scattered diurnal cumulus clouds will be around this afternoon with high pressure building in. Clear skies and light winds tonight will likely lead to some radiation fog at KGFL/KPSF after 06Z Tuesday. Occasional IFR conditions look probable. Potential fog development more uncertain at KALB/KPOU, so will leave out mention for now. Winds will be light and variable, becoming N-NW around 5 kt later this morning. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 80 to near 100 percent tonight. Minimum values Tuesday afternoon are forecast to be generally 40 to 50 percent south of Interstate 90 and 35 to 45 percent north of Interstate 90. Light northerly winds today will diminish tonight with a southerly flow developing Tuesday at generally less than 10 mph. && .HYDROLOGY... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/BGM SHORT TERM...IAA LONG TERM...JPV AVIATION...JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service Albany NY 1025 AM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1020 AM...Low stratus has eroded rather quickly and being replaced by CU/SC with a canopy of higher CI/CS advecting across the entire region. While this may have slowed down the diurnal temperature climb a bit, expectations are for a partly-mostly sunny day with terrain based cumulus clouds. Per the 12Z sounding, rather stable exists up to H700 and per mixing layer heights, forecast highs look good with no changes needed at this time. Prev Disc... Heights will rise as ridging builds in at all levels of the atmosphere today. Have variable cloudy skies across the area as higher level clouds stream in from northwest and have some lingering stratus from overnight. Will have partly to mostly sunny skies today. Light northerly flow across the area with seasonable temperatures expected along with comfortable dew points mainly in the 50s. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Heat and humidity return. Ridging will continue to build in. The surface high will begin to shift offshore on Tuesday with a southerly return flow developing. Aloft the ridge axis is forecast to crest over the region late Tuesday night/Wednesday morning with the axis shifting off the seaboard during the day. In the meantime, a stacked low pressure system will be on the gradual approach. Deep southwest flow will develop between the departing ridge and the approaching trough. Heat and humidity will be in the rise and will be very noticeably on Wednesday. 850 mb temperatures are forecast to rise to 16 to 18 degrees Celsius on Wednesday. Highs Tuesday are expected to be in the upper 70s to upper 80s with dew points rising into the upper 50s to mid 60s. Dew points will continue to rise Tuesday night into Wednesday with widespread mid to upper 60s anticipated. These values combined with high temperatures expected to top out in mainly on the 80s to lower 90s with result in heat indices in the upper 80s to upper 90s. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. As the atmosphere warms up and becomes increasingly more humid and unstable the threat of convection will be in the rise. With only subtle height fall expected Wednesday and upper level support remaining well to the west have slight chance pops across the local area for the afternoon hours. However, the chances for convection will continue Wednesday night as the upper trough and low pressure system`s cold front move into the Great Lakes region. Better chances will be west of the Hudson River Valley. The Storm Prediction Center has the region under a general thunderstorm outlook. Storms will be capable of locally heavy rainfall as precipitable water values are forecast to rise to 1.5+ inches. && .LONG TERM /THURSDAY THROUGH SUNDAY/... The period starts out on Thursday with our region still under the influence of a very warm and moist southerly flow. It will become increasingly humid, with models indicating a pre-frontal trough moving through at some point during the afternoon or evening. This trough is expected to result in scattered showers and thunderstorms. Some of the storms could be on the stronger side depending on the eventual magnitude of instability and deep layer shear. Given the anticipated above normal PWATS of +1 to +2 STDEV, heavy rainfall is likely to occur within any persistent thunderstorms. Another rather subtle boundary may move across the region on Friday, with more mainly diurnal showers and thunderstorms. Models are showing a weaker system now compared to Thursday, but with the continued warm and humid air mass in place, scattered convection looks reasonable again. It will likely remain very warm and muggy Friday. Some of the 00Z model guidance showing a wave of low pressure developing along a fairly flat and progressive upper level trough for Saturday. Some GEFS ensemble members also depicting this potential wave with some probabilities for precip as well, so will raise pops to 30 percent to account for this possibility. This potential system should exit the region by Sunday with drier weather to close out the weekend. Overall, temperatures look to "cool" closer to normal values during the upcoming weekend, with somewhat of a reprieve in humidity levels as well. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... VFR conditions expected across the terminals today into tonight. Only scattered diurnal cumulus clouds will be around this afternoon with high pressure building in. Clear skies and light winds tonight will likely lead to some radiation fog at KGFL/KPSF after 06Z Tuesday. Occasional IFR conditions look probable. Potential fog development more uncertain at KALB/KPOU, so will leave out mention for now. Winds will be light and variable, becoming N-NW around 5 kt later this morning. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 80 to near 100 percent tonight. Minimum values Tuesday afternoon are forecast to be generally 40 to 50 percent south of Interstate 90 and 35 to 45 percent north of Interstate 90. Light northerly winds today will diminish tonight with a southerly flow developing Tuesday at generally less than 10 mph. && .HYDROLOGY... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/BGM SHORT TERM...IAA LONG TERM...JPV AVIATION...JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service Taunton MA 1009 AM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build over New England today, resulting in clearing skies and more seasonable temperatures. Heat and humidity will increase this week as the high becomes centered offshore and brings a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 1000 AM Update... Sufficient trapped low level moisture remained over southern New England this morning for clouds to develop and linger. Still expect this low level moisture to scour out over the course of the day, but clearing across the area will likely take several more hours. Radar showing spotty light returns across eastern MA and RI, and as far west as the Worcester hills. Have added patchy light drizzle to the forecast thru midday as well. Forecast highs look on track, but we will need the anticipated decrease in clouds over the next few hours in order to achieve those highs. So at this time not adjusting forecast highs, but will need to monitor. 300 AM Update... Last of showers were over coastal waters SE of Nantucket and were heading farther offshore. Wide range in conditions across region with partial clearing working into lower CT Valley and outer Cape Cod while clouds remain socked in elsewhere, and it`s foggy across central MA, NE CT, and parts of E MA where rain fell last evening. Weak surface low was passing well south of New England which has maintained light N flow. There is a lot of low level moisture trapped beneath subsidence inversion, so clouds/patchy fog will hang around through daybreak, before clearing begins during morning. Some of the higher-res models (most notably HRRR, RAP, and NAM) show some light precipitation early this morning, primarily in E MA. This appears to be spotty drizzle due to deeper marine layer. Since cloud heights are not all that low in this area right now, will probably leave mention out of forecast. Question for today is how fast does clearing occur? RAP forecast soundings show reasonable trend, with much of interior breaking out 12z-14z and coastal areas a bit later, more like 14z-18z. This looks like one of those situations where low clouds erode on edges, as opposed to clearing taking place from W to E, so it`s possible some areas away from coast (E of CT River) take longer than expected to clear out. Gradient remains weak today so expect coastal sea breezes to develop later this morning and early this afternoon. Forecast highs in 70s look reasonable based upon model 2-meter temperatures. Should get to around 80 in the CT and Merrimack Valleys. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... High pressure builds over southern New England tonight. Light winds, clear skies, and a dry airmass will help lows fall back into the 50s inland (where we may see some patchy valley fog) and to the lower 60s near coast. As the high becomes centered offshore Tuesday, we get into return SW flow which will begin to bring warmer (and eventually more humid) air into region. Highs will top out well into 80s (except 70s near South Coast) if not around 90 in parts of CT and Merrimack Valleys. Some of the models (00z GFS and 21z SREF in particular) try to bring showers/storms into southern New England Tue afternoon, as moisture is drawn up from the mid Atlantic states and interacts with a weak surface trough. We are not buying into this wetter solution given axis of 500 mb ridge to our W with larger scale subsidence present over region. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Highlights... * Becoming hot and humid late in the week. * Scattered thunderstorms will likely affect the region late Thu and Fri. * Low confidence forecast for the weekend. May have more showers on Sat. OVERALL PICTURE... Upper flow across North America becomes more zonal for a time this coming week. Fairly high confidence of hot temperatures and increasing humidity for the middle and latter part of the week. Have a risk of approaching Heat Advisory criteria on Thursday if dewpoints reach at least 70. Shortwave trof rotating about Hudson Bay vortex and associated surface front approaches southern New England Thursday night. The timing of this feature will be critical as to threat of strong to severe thunderstorms. Model consensus would seem to suggest that the front may pass through southern New England Friday morning or early afternoon, not diurnally optimal for convection. Confidence is relatively low for the weekend. May not be as dry as originally thought since flow aloft remains cyclonic and from the WSW or SW. Also, both the 00Z GFS and ECMWF operational runs suggest a frontal wave on Saturday. DETAILS... Wed...Temperatures will likely reach mid 80s to lower 90s. Cannot rule out isolated thunderstorm over the western higher terrain areas but expect that most, if not all, of region remains dry. Thu...Operational models have ensemble support for a hot/humid day. H850 temperatures will likely rise to at least around 18C and will likely see all but the south coast and highest terrain areas reach 90 to 95. Sufficient instability may exist for scattered pulse late afternoon/evening thunderstorms in the western zones. As the surface front or prefrontal trough approaches, convection may persist into the night for a time across the western zones. Fri...Upper short wave trof and associated surface front crosses the region. Timing is critical with regard to convective potential. Model consensus for now would seem to have the frontal boundary making it to the coast by midday or early afternoon, too soon to tap into diurnal heating. However, Friday is still 5 days away and so cannot be all that confident on timing details. There looks to be sufficient bulk shear to support organized storms if the instability is sufficient. Expect max temperatures to be a few degrees lower than Thursday due to increased cloudiness. Nevertheless, many locations are expected to reach into the lower 90s with dewpoints in the upper 60s to near 70. Next weekend...Confidence is relatively low at this time regarding next Saturday and Sunday. Both the GFS and ECMWF operational runs depict the broad upper trof axis to be west of the area and even hint at a frontal wave passing through or just SE of the area on Saturday. Have raised POPs and sky cover some for Saturday as a consequence. Also, lowered temperatures along the coastal plain a tad as well due to potential for more clouds and possibly onshore flow. If a surface wave forms more as per the GFS, then temperatures would likely be cooler and rainfall steadier. On the other hand, the ECMWF might keep some of southern New England in the warm sector and more convectively active. It is just too soon to be able to nail down specifics this far out. Have opted for POPs below chance for Sunday as looks for now that drier air should infiltrate the region from the west. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 06Z TAF Update... Today...Moderate confidence. 14Z update... Areas of MVFR ceilings should persist until 15Z-18Z, especially across RI and eastern MA. Otherwise, becoming VFR as ceilings lift and clouds decrease in coverage. N/NE winds will be quite light and so should give way to coastal sea breezes around midday or early this afternoon. Tonight and Tuesday...High confidence. VFR, but local MVFR/IFR possible in valley fog. Light winds tonight will give way to S/SW winds Tue. KBOS TAF...Moderate confidence. MVFR ceilings persist until 15-16Z, then VFR expected. Light N/NE flow gives way to weak sea breeze around 16z. KBDL TAF...Moderate confidence. Ceilings may briefly go to MVFR during late this morning, otherwise VFR conditions forecast. Outlook /Tuesday Night through Friday/...High confidence. Tuesday night through Thursday morning...Generally VFR except areas of MVFR/IFR in fog along the south coast. Thursday afternoon through Friday...Generally VFR but areas of MVFR cigs/vsbys in vicinity of scattered showers and thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England today. Light N/NE flow gives way to local sea breezes later this morning and early this afternoon. SW flow gets underway Tue as high becomes centered offshore. Outlook /Tuesday Night through Friday/...High confidence. Relatively light wind fields are expected and seas should generally remain below 5 feet across all waters. There will be areas of late night and early morning fog, especially along the south coastal waters during this time period. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...JWD/Thompson NEAR TERM...NMB/JWD/Thompson SHORT TERM...JWD LONG TERM...Thompson AVIATION...NMB/JWD/Thompson MARINE...JWD/Thompson Area Forecast Discussion National Weather Service Albany NY 448 AM EDT TUE JUL 12 2016 .SYNOPSIS... Heat and humidity return especially for Wednesday and Thursday. Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday with locally heavy rainfall expected. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Warmer today as the heat and humidity begin to return. Ridging will continue to build in aloft today with the 500 mb ridge axis expected to crest over the region by late in the day. At the surface, the high will begin to shift offshore with a southerly return flow developing. Highs today are expected to be several degrees warmer than yesterday; mainly in the 80s with mid-upper 70s across the higher terrain of the southern Adirondacks, eastern Catskills and southern Green Mountains. Dew points will begin to rise with as the southerly flow develops with values expected to be in the upper 50s to lower 60s by this evening. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... Hot and humid Wednesday and Thursday. Storms with locally heavy rainfall expected on Thursday. Aloft the ridge axis will begin to shift eastward overnight into Wednesday as a stacked low pressure system located over southern Manitoba moves northeastward. Deep southwest flow will develop between the departing ridge and the approaching trough which will help bring on the heat and humidity. 850 mb temperatures are still forecast to rise to 16 to 18 degrees Celsius on Wednesday and remained high through Thursday. Dew points are forecast to rise mid to upper 60s Wednesday with upper 60s to lower 70s for Thursday. Looking for highs Wednesday in the mid 80s to lower 90s and in the upper 70s to upper 80s Thursday. These temperatures combined with the high dew points will result in heat indices in the upper 80s to upper 90s both days. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. The nights will be very muggy with lows only in the mid 60s to lower 70s with dew points not far behind. The approaching system is expected weaken as the upper low opens and become incorporated in the large upper level low over Hudson`s Bay by Wednesday night. This will leave our region on the southern periphery of the longwave trough with weak short waves moving through the flow and only meager height falls across the region as the system`s cold front gradually approaches. With such a warm and humid air mass in place and possible subtle short wave moving through the flow can not rule out the threat for isolated thunderstorms Wednesday and Wednesday night. More widespread chances are expected on Thursday a as weak short wave moves through the flow. Chances for organized storms will remain to our north across far northern New York where better forcing will be present. The Storm Prediction Center has our region in the general thunderstorm outlook for both Wednesday and Thursday. Precipitable water values are forecast to rise to 1.5 to near 2 inches, which is 1-2 standard deviations above normal, so storms will be capable of locally heavy rainfall. The heavy downpours could result in some minor urban flooding of poor drainage and low lying areas. Have added mention of heavy rainfall to forecast for Thursday and will continue to have mention in our Hazardous Weather Outlook. && .LONG TERM /FRIDAY THROUGH MONDAY/... The period starts out on Friday with a cold front pushing southeastward across the area, mainly during the first half of the day. Models have come into better agreement with the timing. It will still be very warm and humid across the southern half of the area, with some locations in the Hudson Valley near Kingston and Poughkeepsie expected to exceed 90 degrees. Some modest instability and moisture in place will result in isolated to scattered convection. Best chances will be across the Adirondacks which will be closer to a short wave trough moving through northern NY. Any showers and thunderstorms should diminish Friday evening after diurnal heating is lost. Weak high pressure will then attempt to build into the region late Friday night into Saturday. However, the GFS and CMC are still depicting a wave of low pressure developing along the old frontal boundary that will stall to our south over the mid Atlantic states. The latest ECMWF has backed off on this wave despite having a slightly deeper upper level trough over the Midwest and Great Lakes. Will maintain low chance pops for Saturday, but with increasing uncertainty. Depending on the track of the area of low pressure, it could end up being cooler should the clouds/showers accompanying the low affect our region. Again, this is uncertain so will trend close to guidance which is depicting temperatures near normal. More differences in models for Sunday, with the GFS/CMC indicating weak high pressure building back in with a flatter flow pattern aloft. However, the ECMWF is showing some unsettled weather with a deeper trough moving into the Northeast. With a lingering upper level trough over the region into Monday and northwest flow aloft, widely scattered diurnal convection cannot be ruled out. Overall there is not much to indicate any strong signals, so will stay close to climo for temps/pops into early next week. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... High pressure in place across the region with mainly clear skies and calm winds. Some high level cirrus clouds continue to drift across the area from time to time. Fairly dry air mass in place for mid July, although radiation fog with occasional IFR conditions has already occurred at KGFL, with fog development expected at KPSF by 07Z or 08Z. Will mention any IFR in tempo groups due to some uncertainty regarding persistence of thick fog. IFR not anticipated at KALB/KPOU, but there could be some fog in the vicinity of KALB near the Mohawk River. Will mention brief MVFR vsby possible at KPOU, but thicker fog development should not occur. Any fog should dissipate by 11Z, with VFR conditions prevailing thereafter. Scattered diurnal cumulus clouds should develop with scattered-broken high level cirrus clouds around today too. Winds will be calm, then become southerly around 4-7 kt by early afternoon. Outlook... Wednesday Night: Low Operational Impact. Slight Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Low Operational Impact. Slight Chance of SHRA...TSRA. Friday Night: No Operational Impact. NO SIG WX. Saturday: Moderate Operational Impact. Chance of SHRA. && .FIRE WEATHER... Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight. Minimum values Wednesday afternoon are forecast to range from 45 to 55 percent. A southerly flow will develop today and persisting through Wednesday. && .HYDROLOGY... Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday with locally heavy rainfall expected. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. The heavy downpours could result in some minor urban flooding of poor drainage and low lying areas. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA SHORT TERM...IAA LONG TERM...JPV AVIATION...JPV FIRE WEATHER...IAA HYDROLOGY...IAA
  [top] Area Forecast Discussion National Weather Service New York NY 444 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure moves offshore today and will continue to remain in control through Wednesday. A prefrontal trough approaches Wednesday night and moves through Thursday night into Friday. A cold front moves through the area Friday night. High pressure builds behind the front Saturday. Another frontal system approaches for Saturday night into Sunday night. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Ridging continues to build aloft today as surface high pressure sets up off the middle atlantic coast. Some mid level moisture rolling over the ridge axis to the west will bring some scattered clouds this afternoon, but sky conditions should average mostly sunny through the day. Winds around the high will increase out of the south preventing temperatures near the coast from rising above the lower 80s. For the New York City metro and the interior, temperatures warm to normal levels for this time of year in the middle 80s. There is a moderate risk of rip current development at the Atlantic facing beaches today. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... Dew points will be on the rise tonight with continued southerly flow. However, there should be enough of a pressure gradient to keep winds from going completely calm. NAM12, NAM4KM, and SREF BUFKIT profiles support this, so have not included any mention of patchy fog. Upper ridge axis moves over the region Wednesday morning and then continues east of the area through the day. Capping is noted on model soundings around 500 hPa as the region is still in close proximity to the ridge axis. This should prevent any convection from developing, although shortwave energy over the Ohio Valley begins to approach late in the day. Have continued the thinking from the previous forecast package for a slight chance of a shower or storm drifting into the NW interior late in the afternoon. Warmer air continues to be transported around the offshore high on Wednesday. 850 hPa temperatures warm 2C to 4C from those on Tuesday. Forecast highs are in the middle and upper 80s for the city and for inland location, and the lower 80s near the coast. It will also feel more humid as dew points rise into the middle and upper 60s. Heat indices could briefly touch 90 degrees in the afternoon for the NYC metro and across the interior. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... High pressure and an upper ridge axis will be moving east of the area late Wednesday afternoon into Wednesday evening. The area will then be under the influence of an upper trough into Monday as weak shortwave and associated vorts rotate through the trough. Meanwhile at the surface, as high pressure exits Wednesday evening a prefrontal trough moves into the region well ahead of a cold front. The trough moves slowly through Thursday night into Friday with the cold front passing through Friday night. As a result will have slight chance to low end chance pops Wednesday evening into Friday with the cold front likely coming through dry Friday night as the area stabilizes behind the trough. There remains some uncertainty with the timing of the shortwaves and when the best chances of precipitation will be at this time. Friday looks to be warmest day of the extended period as some clearing occurs ahead of the cold front and 850 MB temperatures near 20C. There will be a brief dry period Friday night into Saturday as upper trough weakens and surface high pressure builds. However, and stronger shortwave and vort moves through southern Canada Saturday night into Sunday with a weak surface trough developing. Will again have slight to low chance pops for Saturday night into Sunday night as there remains uncertainty with the timing and placement of the shortwaves. Monday will likely be dry with yet another shortwave possible for Monday night into Tuesday. && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area throughout the day. VFR conditions with southerly winds through the TAF period. Generally light winds early this morning have veered more toward the west or southwest at some terminals, but expect these sites to return to southerly flow shortly after daybreak. The gradient tightens this afternoon with some of the coastal terminals increasing to around 15 kt. ...NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http://www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments expected. KLGA TAF Comments: No unscheduled amendments expected. KEWR TAF Comments: No unscheduled amendments expected. The afternoon KEWR haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected. KHPN TAF Comments: No unscheduled amendments expected. KISP TAF Comments: No unscheduled amendments expected. .OUTLOOK FOR 06Z Wednesday through Saturday... .Tue Night-Wed...VFR. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressures settles offshore today and will remain in control through Wednesday. Afternoon sea breezes may bring winds close to 20 KT on the western ocean waters each day. Otherwise, winds and seas will remain below advisory levels. A weak surface pressure gradient force will be across the forecast waters Wednesday night through Saturday as prefrontal trough moves through Thursday night into Friday with a cold frontal passage Friday night. Winds and seas will remain below advisory levels Wednesday night through Saturday. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...DS/MET NEAR TERM...DS SHORT TERM...DS LONG TERM...MET AVIATION...FEB MARINE...DS/MET HYDROLOGY...DS/MET
Area Forecast Discussion National Weather Service New York NY 444 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure moves offshore today and will continue to remain in control through Wednesday. A prefrontal trough approaches Wednesday night and moves through Thursday night into Friday. A cold front moves through the area Friday night. High pressure builds behind the front Saturday. Another frontal system approaches for Saturday night into Sunday night. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Ridging continues to build aloft today as surface high pressure sets up off the middle atlantic coast. Some mid level moisture rolling over the ridge axis to the west will bring some scattered clouds this afternoon, but sky conditions should average mostly sunny through the day. Winds around the high will increase out of the south preventing temperatures near the coast from rising above the lower 80s. For the New York City metro and the interior, temperatures warm to normal levels for this time of year in the middle 80s. There is a moderate risk of rip current development at the Atlantic facing beaches today. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... Dew points will be on the rise tonight with continued southerly flow. However, there should be enough of a pressure gradient to keep winds from going completely calm. NAM12, NAM4KM, and SREF BUFKIT profiles support this, so have not included any mention of patchy fog. Upper ridge axis moves over the region Wednesday morning and then continues east of the area through the day. Capping is noted on model soundings around 500 hPa as the region is still in close proximity to the ridge axis. This should prevent any convection from developing, although shortwave energy over the Ohio Valley begins to approach late in the day. Have continued the thinking from the previous forecast package for a slight chance of a shower or storm drifting into the NW interior late in the afternoon. Warmer air continues to be transported around the offshore high on Wednesday. 850 hPa temperatures warm 2C to 4C from those on Tuesday. Forecast highs are in the middle and upper 80s for the city and for inland location, and the lower 80s near the coast. It will also feel more humid as dew points rise into the middle and upper 60s. Heat indices could briefly touch 90 degrees in the afternoon for the NYC metro and across the interior. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... High pressure and an upper ridge axis will be moving east of the area late Wednesday afternoon into Wednesday evening. The area will then be under the influence of an upper trough into Monday as weak shortwave and associated vorts rotate through the trough. Meanwhile at the surface, as high pressure exits Wednesday evening a prefrontal trough moves into the region well ahead of a cold front. The trough moves slowly through Thursday night into Friday with the cold front passing through Friday night. As a result will have slight chance to low end chance pops Wednesday evening into Friday with the cold front likely coming through dry Friday night as the area stabilizes behind the trough. There remains some uncertainty with the timing of the shortwaves and when the best chances of precipitation will be at this time. Friday looks to be warmest day of the extended period as some clearing occurs ahead of the cold front and 850 MB temperatures near 20C. There will be a brief dry period Friday night into Saturday as upper trough weakens and surface high pressure builds. However, and stronger shortwave and vort moves through southern Canada Saturday night into Sunday with a weak surface trough developing. Will again have slight to low chance pops for Saturday night into Sunday night as there remains uncertainty with the timing and placement of the shortwaves. Monday will likely be dry with yet another shortwave possible for Monday night into Tuesday. && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area throughout the day. VFR conditions with southerly winds through the TAF period. Generally light winds early this morning have veered more toward the west or southwest at some terminals, but expect these sites to return to southerly flow shortly after daybreak. The gradient tightens this afternoon with some of the coastal terminals increasing to around 15 kt. ...NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http://www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments expected. KLGA TAF Comments: No unscheduled amendments expected. KEWR TAF Comments: No unscheduled amendments expected. The afternoon KEWR haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected. KHPN TAF Comments: No unscheduled amendments expected. KISP TAF Comments: No unscheduled amendments expected. .OUTLOOK FOR 06Z Wednesday through Saturday... .Tue Night-Wed...VFR. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressures settles offshore today and will remain in control through Wednesday. Afternoon sea breezes may bring winds close to 20 KT on the western ocean waters each day. Otherwise, winds and seas will remain below advisory levels. A weak surface pressure gradient force will be across the forecast waters Wednesday night through Saturday as prefrontal trough moves through Thursday night into Friday with a cold frontal passage Friday night. Winds and seas will remain below advisory levels Wednesday night through Saturday. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...DS/MET NEAR TERM...DS SHORT TERM...DS LONG TERM...MET AVIATION...FEB MARINE...DS/MET HYDROLOGY...DS/MET
Area Forecast Discussion National Weather Service New York NY 355 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure moves offshore today and will continue to remain in control through Wednesday. A prefrontal trough approaches Wednesday night and moves through Thursday night into Friday. A cold front moves through the area Friday night. High pressure builds behind the front Saturday. Another frontal system approaches for Saturday night into Sunday night. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Ridging continues to build aloft today as surface high pressure sets up off the middle atlantic coast. Some mid level moisture rolling over the ridge axis to the west will bring some scattered clouds this afternoon, but sky conditions should average mostly sunny through the day. Winds around the high will increase out of the south preventing temperatures near the coast from rising above the lower 80s. For the New York City metro and the interior, temperatures warm to normal levels for this time of year in the middle 80s. There is a moderate risk of rip current development at the Atlantic facing beaches today. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... Dew points will be on the rise tonight with continued southerly flow. However, there should be enough of a pressure gradient to keep winds from going completely calm. NAM12, NAM4KM, and SREF BUFKIT profiles support this, so have not included any mention of patchy fog. Upper ridge axis moves over the region Wednesday morning and then continues east of the area through the day. Capping is noted on model soundings around 500 hPa as the region is still in close proximity to the ridge axis. This should prevent any convection from developing, although shortwave energy over the Ohio Valley begins to approach late in the day. Have continued the thinking from the previous forecast package for a slight chance of a shower or storm drifting into the NW interior late in the afternoon. Warmer air continues to be transported around the offshore high on Wednesday. 850 hPa temperatures warm 2C to 4C from those on Tuesday. Forecast highs are in the middle and upper 80s for the city and for inland location, and the lower 80s near the coast. It will also feel more humid as dew points rise into the middle and upper 60s. Heat indices could briefly touch 90 degrees in the afternoon for the NYC metro and across the interior. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... High pressure and an upper ridge axis will be moving east of the area late Wednesday afternoon into Wednesday evening. The area will then be under the influence of an upper trough into Monday as weak shortwave and associated vorts rotate through the trough. Meanwhile at the surface, as high pressure exits Wednesday evening a prefrontal trough moves into the region well ahead of a cold front. The trough moves slowly through Thursday night into Friday with the cold front passing through Friday night. As a result will have slight chance to low end chance pops Wednesday evening into Friday with the cold front likely coming through dry Friday night as the area stabilizes behind the trough. There remains some uncertainty with the timing of the shortwaves and when the best chances of precipitation will be at this time. Friday looks to be warmest day of the extended period as some clearing occurs ahead of the cold front and 850 MB temperatures near 20C. There will be a brief dry period Friday night into Saturday as upper trough weakens and surface high pressure builds. However, and stronger shortwave and vort moves through southern Canada Saturday night into Sunday with a weak surface trough developing. Will again have slight to low chance pops for Saturday night into Sunday night as there remains uncertainty with the timing and placement of the shortwaves. Monday will likely be dry with yet another shortwave possible for Monday night into Tuesday. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area through Tuesday. This will result in mainly VFR conditions with southerly winds. Gradient tightens Tuesday afternoon with some of the coastal terminals increasing to around 15 kt. Patchy MVFR BR at rural airports towards sunrise. .OUTLOOK FOR 06Z Wednesday through Saturday... .Tue Night-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressures settles offshore today and will remain in control through Wednesday. Afternoon sea breezes may bring winds close to 20 KT on the western ocean waters each day. Otherwise, winds and seas will remain below advisory levels. A weak surface pressure gradient force will be across the forecast waters Wednesday night through Saturday as prefrontal trough moves through Thursday night into Friday with a cold frontal passage Friday night. Winds and seas will remain below advisory levels Wednesday night through Saturday. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...DS/MET NEAR TERM...DS SHORT TERM...DS LONG TERM...MET AVIATION...FEB/DW MARINE...DS/MET HYDROLOGY...DS/MET
  [top] Area Forecast Discussion National Weather Service Taunton MA 346 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure over New England will move offshore today resulting in a trend toward warmer and more humid weather for the remainder of the workweek. First look at the weekend appears not as hot and humid. As for precipitation...a cold front will introduce the risk of scattered showers and thunderstorms Thu (inland) and Fri (RI and eastern MA). More unsettled weather is possible over the weekend with a period of rain possible Saturday or Sunday. && .NEAR TERM /THROUGH TODAY/... Updated at 345 am. Clear skies across region early this morning with light winds. Usual interior cool spots have dropped into 50s, and with low temperature/dewpoint spreads patchy fog has formed in the usual low lying areas. Expect any fog to quickly lift around sunrise. High pressure becomes centered off the coast today while upper ridge builds over New England. This will bring warmer SW flow to the region, although models show gradient may weaken enough to allow for sea breezes along E MA coast. Not sure that will be the case, however, since forecast soundings show potential mixing up to 830 mb this afternoon. Looks to be a situation where weak sea breeze may develop offshore but never make it onto land. In any case, plenty of sunshine is expected despite high clouds from convection in upper Midwest making trip around the top of upper ridge. Leaned toward a MOS blend which gives highs well into 80s, except upper 70s along immediate South Coast. && .SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/... Updated at 345 am. Light SW flow persists tonight as upper ridge axis extends over New England. Should also see patchy mid/high clouds from remnants of upstream convection and warm advection aloft, so lows tonight will be a few degrees higher than recent nights, mainly in 60s. Question for Wednesday is whether or not we see any convection in western New England. SW flow continues across region which will serve to stabilize increasingly warm/humid airmass in place along and SE of I-95. Farther west toward Berkshires, models show SB CAPES between 1000 and 2000 J/kg but 0-6km shear is weak (less than 20 kt) as are mid level lapse rates (less than 5C/km). In addition, 700 mb temperatures are rather warm and should act to suppress any convection. Nonetheless, it is possible we see a few showers or perhaps an isolated thunderstorm Wednesday afternoon, so included that mention across western New England. A hotter day is in store despite continued presence of mid and high clouds. Once again leaned toward MOS blend which gives highs well into 80s (but around 90 across lower CT and Merrimack Valleys and closer to 80 near the South Coast). Dewpoints should climb into 60s which will make it feel more humid, but heat indices should stay close to actual temperatures, which would be below Advisory criteria. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Updated at 345 am. Highlights ... * Risk of scattered T-storms Thu (inland) & Fri (RI & eastern MA) * Additional showers possible over the weekend * Very warm and humid Thu and Fri Synoptic Overview ... Good model agreement among ensembles and deterministic guidance regarding the large scale flow this period with east coast ridge moving offshore Wed night and replaced by long wave trough setting up over the Great Lakes Thu and Fri. Some of the guidance suggest the trough deamplifies over the weekend however broad weak mid level cyclonic flow likely lingers across New England Sat and Sun. Thus potential periods of unsettled weather in the form of scattered showers and T-storms into this weekend. Guidance/Model assessment ... As expected at this time range deterministic guidance shows large timing differences. For example...over the weekend the GFS brings another slug of moisture into the region Sat whereas the 00z EC is about 24 hrs later with system arriving Sunday. Thus given the time range here we leaned toward the GEFS and EPS ensembles to better capture the full range of possibilities in the medium and long range. Temperatures ... New 00z guidance suggesting lots of deep layer moisture around Thu and may preclude temps from being as warm as Wed. EPS probs for 90+temps Thu is considerable lower than Wed. Thus have trended temps down Thu, nonetheless still very warm with highs in the MU80s. Highs likely jump back into the 90s Fri as both ensembles and deterministic guid have 850 temps up to +18c/+19c across southern New England. Quite humid Thu and Fri with dew pts climbing to around 70 both days. Therefore a very warm and humid Thu night is expected with lows only in the upper 60s and low 70s. For the weekend northern stream trough erodes the east coast ridge a bit resulting in temps and humidity not as oppressive as Friday. Nonetheless still warm Sat/Sun and Mon with highs well into the 80s away from the ocean. Precipitation ... Looks likes greatest risk for T-storms is Thu (interior) and Fri (RI and Eastern MA). GEFS and EPS both indicate highest probs of 1000- 2000j/kg of cape are Thu (interior) and Fri (RI & eastern MA). Given moderate instability and modest jet dynamics/wind fields could be a risk for a few strong storms Thu and Fri. Also heavy rainers possible as EPS shows high probs of PWATS of 1.5 to 2.0 inches Thu into Fri. Another chance of rain over the weekend but deterministic guidance showing a large spread in timing differences. Ensembles not much help here as it appears to be a frontal wave sliding south of New England and likely too small for ensembles to resolve. Thus low confidence forecast for the weekend. Given there is a risk for showers/T-storms just about any day this period there will also be many hours of dry weather too. Thus not a complete washout. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Updated at 345 am. Today through Wednesday...High confidence. Patchy fog in low lying areas will bring local MVFR/IFR vsbys through sunrise. Otherwise VFR today with S/SW flow. Gradient appears just strong enough to prevent sea breezes along E MA coast, but winds could back to SE for a time mainly 18z-22z. May see another round of patchy valley fog and local MVFR/IFR vsbys tonight. Widely scattered showers/tstms possible Wed afternoon, mainly near Berkshires where brief MVFR conditions are possible. KBOS TAF...High confidence. SW flow should be just strong enough to prevent sea breeze from coming onshore, but winds could back to 170-180 (true) for a couple of hours between 18z and 21z. KBDL TAF...High confidence. Outlook /Wednesday night through Saturday/... Wednesday night through Friday ... Moderate Confidence. VFR. Areas of late night/early morning IFR in fog. Scattered MVFR/IFR in afternoon and evening showers/thunderstorms, mainly Thursday and Friday. Winds becoming southwest much of the period. Saturday ... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Updated at 345 am. Short Term /through Wednesday/...High confidence. High pressure becomes centered SE of New England and brings S/SW flow. Gradient may weaken enough to allow for onshore winds near E MA coast this afternoon, but it`s more likely winds stay S or SW. Seas may approach 5 FT on outer waters E of Cape Cod late in day Wednesday due to persistent S/SW flow. Patchy fog possible tonight into Wednesday morning on S coastal waters, but is not expected to be dense or widespread. Outlook /Wednesday night through Saturday/ ... Moderate confidence. Persistent S-SW winds of 15 to 20 kt across the waters will result in modest seas. Vsby less than 1 nm at times in night time/morning fog and scattered T-storms. && .CLIMATE... Although we are not expecting record heat, here is a listing of record highs for later this week. July 13: BOS 97 in 1894 PVD 94 in 1994 BDL 99 in 1966 ORH 93 in 1894 July 14: BOS 100 in 1995 PVD 98 in 1995 BDL 100 in 1965 ORH 95 in 1952 July 15: BOS 98 in 1995 PVD 99 in 1995 BDL 100 in 1995 ORH 90 in 1892 Average Highs: BOS 82 PVD 83 BDL 85 ORH 79 && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Nocera/JWD NEAR TERM...JWD SHORT TERM...JWD LONG TERM...Nocera AVIATION...Nocera/JWD MARINE...Nocera/JWD CLIMATE...Staff
Area Forecast Discussion National Weather Service Taunton MA 346 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure over New England will move offshore today resulting in a trend toward warmer and more humid weather for the remainder of the workweek. First look at the weekend appears not as hot and humid. As for precipitation...a cold front will introduce the risk of scattered showers and thunderstorms Thu (inland) and Fri (RI and eastern MA). More unsettled weather is possible over the weekend with a period of rain possible Saturday or Sunday. && .NEAR TERM /THROUGH TODAY/... Updated at 345 am. Clear skies across region early this morning with light winds. Usual interior cool spots have dropped into 50s, and with low temperature/dewpoint spreads patchy fog has formed in the usual low lying areas. Expect any fog to quickly lift around sunrise. High pressure becomes centered off the coast today while upper ridge builds over New England. This will bring warmer SW flow to the region, although models show gradient may weaken enough to allow for sea breezes along E MA coast. Not sure that will be the case, however, since forecast soundings show potential mixing up to 830 mb this afternoon. Looks to be a situation where weak sea breeze may develop offshore but never make it onto land. In any case, plenty of sunshine is expected despite high clouds from convection in upper Midwest making trip around the top of upper ridge. Leaned toward a MOS blend which gives highs well into 80s, except upper 70s along immediate South Coast. && .SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/... Updated at 345 am. Light SW flow persists tonight as upper ridge axis extends over New England. Should also see patchy mid/high clouds from remnants of upstream convection and warm advection aloft, so lows tonight will be a few degrees higher than recent nights, mainly in 60s. Question for Wednesday is whether or not we see any convection in western New England. SW flow continues across region which will serve to stabilize increasingly warm/humid airmass in place along and SE of I-95. Farther west toward Berkshires, models show SB CAPES between 1000 and 2000 J/kg but 0-6km shear is weak (less than 20 kt) as are mid level lapse rates (less than 5C/km). In addition, 700 mb temperatures are rather warm and should act to suppress any convection. Nonetheless, it is possible we see a few showers or perhaps an isolated thunderstorm Wednesday afternoon, so included that mention across western New England. A hotter day is in store despite continued presence of mid and high clouds. Once again leaned toward MOS blend which gives highs well into 80s (but around 90 across lower CT and Merrimack Valleys and closer to 80 near the South Coast). Dewpoints should climb into 60s which will make it feel more humid, but heat indices should stay close to actual temperatures, which would be below Advisory criteria. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Updated at 345 am. Highlights ... * Risk of scattered T-storms Thu (inland) & Fri (RI & eastern MA) * Additional showers possible over the weekend * Very warm and humid Thu and Fri Synoptic Overview ... Good model agreement among ensembles and deterministic guidance regarding the large scale flow this period with east coast ridge moving offshore Wed night and replaced by long wave trough setting up over the Great Lakes Thu and Fri. Some of the guidance suggest the trough deamplifies over the weekend however broad weak mid level cyclonic flow likely lingers across New England Sat and Sun. Thus potential periods of unsettled weather in the form of scattered showers and T-storms into this weekend. Guidance/Model assessment ... As expected at this time range deterministic guidance shows large timing differences. For example...over the weekend the GFS brings another slug of moisture into the region Sat whereas the 00z EC is about 24 hrs later with system arriving Sunday. Thus given the time range here we leaned toward the GEFS and EPS ensembles to better capture the full range of possibilities in the medium and long range. Temperatures ... New 00z guidance suggesting lots of deep layer moisture around Thu and may preclude temps from being as warm as Wed. EPS probs for 90+temps Thu is considerable lower than Wed. Thus have trended temps down Thu, nonetheless still very warm with highs in the MU80s. Highs likely jump back into the 90s Fri as both ensembles and deterministic guid have 850 temps up to +18c/+19c across southern New England. Quite humid Thu and Fri with dew pts climbing to around 70 both days. Therefore a very warm and humid Thu night is expected with lows only in the upper 60s and low 70s. For the weekend northern stream trough erodes the east coast ridge a bit resulting in temps and humidity not as oppressive as Friday. Nonetheless still warm Sat/Sun and Mon with highs well into the 80s away from the ocean. Precipitation ... Looks likes greatest risk for T-storms is Thu (interior) and Fri (RI and Eastern MA). GEFS and EPS both indicate highest probs of 1000- 2000j/kg of cape are Thu (interior) and Fri (RI & eastern MA). Given moderate instability and modest jet dynamics/wind fields could be a risk for a few strong storms Thu and Fri. Also heavy rainers possible as EPS shows high probs of PWATS of 1.5 to 2.0 inches Thu into Fri. Another chance of rain over the weekend but deterministic guidance showing a large spread in timing differences. Ensembles not much help here as it appears to be a frontal wave sliding south of New England and likely too small for ensembles to resolve. Thus low confidence forecast for the weekend. Given there is a risk for showers/T-storms just about any day this period there will also be many hours of dry weather too. Thus not a complete washout. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Updated at 345 am. Today through Wednesday...High confidence. Patchy fog in low lying areas will bring local MVFR/IFR vsbys through sunrise. Otherwise VFR today with S/SW flow. Gradient appears just strong enough to prevent sea breezes along E MA coast, but winds could back to SE for a time mainly 18z-22z. May see another round of patchy valley fog and local MVFR/IFR vsbys tonight. Widely scattered showers/tstms possible Wed afternoon, mainly near Berkshires where brief MVFR conditions are possible. KBOS TAF...High confidence. SW flow should be just strong enough to prevent sea breeze from coming onshore, but winds could back to 170-180 (true) for a couple of hours between 18z and 21z. KBDL TAF...High confidence. Outlook /Wednesday night through Saturday/... Wednesday night through Friday ... Moderate Confidence. VFR. Areas of late night/early morning IFR in fog. Scattered MVFR/IFR in afternoon and evening showers/thunderstorms, mainly Thursday and Friday. Winds becoming southwest much of the period. Saturday ... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Updated at 345 am. Short Term /through Wednesday/...High confidence. High pressure becomes centered SE of New England and brings S/SW flow. Gradient may weaken enough to allow for onshore winds near E MA coast this afternoon, but it`s more likely winds stay S or SW. Seas may approach 5 FT on outer waters E of Cape Cod late in day Wednesday due to persistent S/SW flow. Patchy fog possible tonight into Wednesday morning on S coastal waters, but is not expected to be dense or widespread. Outlook /Wednesday night through Saturday/ ... Moderate confidence. Persistent S-SW winds of 15 to 20 kt across the waters will result in modest seas. Vsby less than 1 nm at times in night time/morning fog and scattered T-storms. && .CLIMATE... Although we are not expecting record heat, here is a listing of record highs for later this week. July 13: BOS 97 in 1894 PVD 94 in 1994 BDL 99 in 1966 ORH 93 in 1894 July 14: BOS 100 in 1995 PVD 98 in 1995 BDL 100 in 1965 ORH 95 in 1952 July 15: BOS 98 in 1995 PVD 99 in 1995 BDL 100 in 1995 ORH 90 in 1892 Average Highs: BOS 82 PVD 83 BDL 85 ORH 79 && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Nocera/JWD NEAR TERM...JWD SHORT TERM...JWD LONG TERM...Nocera AVIATION...Nocera/JWD MARINE...Nocera/JWD CLIMATE...Staff
Area Forecast Discussion National Weather Service Albany NY 130 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... Ridging will continue to build in aloft with the surface over the region. Mostly clear to partly cloudy skies overnight as some high level cirrus clouds stream across the region. Conditions are favorable for radiation fog development overnight especially in the river valleys locations. With overnight lows bottoming out mainly in the 50s it will be comfortable sleeping weather for most. There will be some upper 40s across the higher terrain of the southern Adirondacks, eastern Catskills and southern Green Mountains. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... High pressure in place across the region with mainly clear skies and calm winds. Some high level cirrus clouds continue to drift across the area from time to time. Fairly dry air mass in place for mid July, although radiation fog with occasional IFR conditions has already occurred at KGFL, with fog development expected at KPSF by 07Z or 08Z. Will mention any IFR in tempo groups due to some uncertainty regarding persistence of thick fog. IFR not anticipated at KALB/KPOU, but there could be some fog in the vicinity of KALB near the Mohawk River. Will mention brief MVFR vsby possible at KPOU, but thicker fog development should not occur. Any fog should dissipate by 11Z, with VFR conditions prevailing thereafter. Scattered diurnal cumulus clouds should develop with scattered-broken high level cirrus clouds around today too. Winds will be calm, then become southerly around 4-7 kt by early afternoon. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...IAA/KL/11 SHORT TERM...KL LONG TERM...11 AVIATION...JPV FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service Taunton MA 116 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure over New England will become centered southeast of New England during Tuesday. Heat and humidity will increase this week with the high remaining centered offshore, bringing a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 115 am Update... Clear skies across region early this morning with light winds. Usual interior cool spots have dropped into 50s, and with low temperature/dewpoint spreads expect to see some patchy fog develop through sunrise. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/... Tuesday... The surface high becomes centered offshore during the day, while upper level ridge builds towards our area from the west. Southern New England gets into return low level SW flow which will begin to bring warmer and eventually more humid air into region. Mostly sunny skies expected, mainly from diurnal cumulus but could see a few higher deck clouds as well. Temperatures rise well into the 80s across much of the area. Exception will be along south coastal MA/RI, where highs in the 70s to near 80 are expected. Expecting an eventual sea breeze development along east coastal MA, but may take into midday/early afternoon to get going and overcome SW flow. Tuesday night... Surface high pressure centered offshore and light SW return flow continues. Upper ridge axis extends over New England. This will be a slightly warmer and more humid night, with lows in the 60s. Could see some patchy valley fog once more, otherwise mostly clear skies expected. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Big Picture... Longwave pattern shows steady heights through the week followed by building heights off the Atlantic Sunday and Monday. Shortwave scale shows an upper ridge with axis over New England Wednesday, shifting southeast Thursday and Friday. Shortwave over the Upper Midwest Wednesday moves into Eastern Canada and sweeps a weak shortwave across New England Friday night. Subtropical high over the Atlantic builds Sunday and Monday while another shortwave approaches from the west on Monday. General model agreement Wednesday to Friday, but uncertainty for Saturday and Sunday. Both show the Friday night cold front stalling to our south. Both the 12Z GFS and ECMWF show dry weather Saturday followed by a wave moving up the front spreading showers into our area Sunday. Earlier runs showed that wave moving past with wet weather Saturday followed by dry weather Sunday. All show high pressure and dry weather Monday. Low confidence as to which will be right for the weekend. We have chosen to compromise between the two camps for now and allow the next couple of runs provide clearer information. Details... Wednesday through Friday... High pressure offshore with a developing southwest flow over the region. This will bring in increasing dew points through the period. Temperatures aloft also increase with 850-equivalent temps 16-17C Wednesday increasing to 18-20C Thursday and Friday. Airmass also becomes increasingly unstable each day with LIs near zero in the CT Valley Wednesday but with limited cloud moisture, then sub-zero LIs across much of the area Thursday and at least part of Friday. Based on this, expect hot temps during this period with max temps either side of 90 Wednesday, and 90-95 Thursday and Friday. Dew points climb to around 70 by Friday morning so humidity levels will be at least noticeable and eventually oppressive. There is a small chance of a thunderstorm in far western MA Wednesday. Thunderstorms more likely Thursday afternoon through Friday. One concern...the GFS and EC both rush precipitation through on Friday morning, while maintaining southwest winds most areas until Friday evening. Perhaps this is focusing showers on a pre-frontal trough and keeping the main front dry. Temps aloft stay warm through the afternoon supporting the idea of a later cold fropa. We massaged the available grid data to keep chance pops into mid afternoon. Specific timing of convection is probably questionable this far out, with the important idea being that there will be precipitation during some part of Friday. Saturday-Sunday-Monday... Much uncertainty in the forecast and forecast data at this time. As noted above, the 12z GFS and EC show a low pressure wave passing us on Sunday with showers while much of the forecast grid data shows showers on Saturday and dry on Sunday. Previous model suites also went with wet weather on Saturday. We have hand-edited our database to show chance pops both days. Expect later model runs will resolve this timing to one day or the other. High pressure brings drier seasonable weather on Monday. && .AVIATION /05Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Today through Wednesday...High confidence. Patchy fog in low lying areas will bring local MVFR or perhaps IFR vsbys through sunrise. Otherwise VFR today with S/SW flow. Gradient appears just strong enough to prevent sea breezes along E MA coast, but winds could back to SE for a time mainly 18z-22z. May see another round of patchy valley fog and local MVFR/IFR vsbys tonight. Widely scattered showers/tstms possible Wed afternoon, mainly near Berkshires where brief MVFR conditions are possible. KBOS TAF...High confidence. SW flow should be just strong enough to prevent sea breeze from coming onshore, but winds could back to 170-180 (true) for a couple of hours between 18z and 21z. KBDL TAF...High confidence. Outlook /Wednesday Night through Saturday/... Wednesday through Friday... Moderate Confidence. VFR. Areas if late night/early morning IFR in fog. Scattered MVFR/IFR in afternoon and evening showers/thunderstorms, mainly Thursday and Friday. Winds becoming southwest much of the period. Saturday... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Wednesday/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England through tonight, and becomes centered offshore during Tuesday. Light and variable wind becomes prevailing SW later tonight and Tuesday, except for local sea breezes redeveloping on Tuesday. Outlook /Wednesday Night through Saturday/... Moderate confidence. Winds below 25 knots through the period. Seas mainly below 5 feet, although there is potential for brief 5 foot seas on the outer waters Thursday night and Friday. Winds becoming southwest for most of the period. Areas of poor visibility in overnight and morning fog. Scattered showers/thunderstorms mainly Thursday and Friday. Low confidence on showers for Saturday. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...WTB/NMB NEAR TERM...JWD SHORT TERM...NMB LONG TERM...WTB AVIATION...JWD MARINE...WTB/NMB
Area Forecast Discussion National Weather Service New York NY 1044 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Some slight adjustments were made regarding the temperatures, dewpoints, and cloud coverage to better match observed trends. The forecast overall remains on track. High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Cirrus clouds decrease overnight with the high pressure center moving closer and with some ridging aloft. With increasing low level moisture and light onshore flow along with cooling temperatures, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior and rural portions of the CWA will drop into the mid to upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. There is a moderate risk of rip current development at the Atlantic facing beaches on Tuesday. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area through Tuesday. This will result in mainly VFR conditions with southerly winds. Gradient tightens Tuesday afternoon with some of the coastal terminals increasing to around 15 kt. Patchy MVFR BR at rural airports towards sunrise. .OUTLOOK FOR 00Z Wednesday through Saturday... .Tue Night-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...JM/MPS SHORT TERM...MPS LONG TERM...JC AVIATION...DW MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service New York NY 1044 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Some slight adjustments were made regarding the temperatures, dewpoints, and cloud coverage to better match observed trends. The forecast overall remains on track. High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Cirrus clouds decrease overnight with the high pressure center moving closer and with some ridging aloft. With increasing low level moisture and light onshore flow along with cooling temperatures, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior and rural portions of the CWA will drop into the mid to upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. There is a moderate risk of rip current development at the Atlantic facing beaches on Tuesday. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area through Tuesday. This will result in mainly VFR conditions with southerly winds. Gradient tightens Tuesday afternoon with some of the coastal terminals increasing to around 15 kt. Patchy MVFR BR at rural airports towards sunrise. .OUTLOOK FOR 00Z Wednesday through Saturday... .Tue Night-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...JM/MPS SHORT TERM...MPS LONG TERM...JC AVIATION...DW MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service Taunton MA 946 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure over New England will become centered southeast of New England during Tuesday. Heat and humidity will increase this week with the high remaining centered offshore, bringing a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 945 pm Update... Quiet night. High clouds moving out of region per IR satellite, which will leave mostly clear skies and light winds. This will allow temperatures to drop off quickly overnight, especially in interior valleys where patchy fog should also form. May also see some fog near RI/MA South Coast. Lows in 50s to lower 60s look good. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Tuesday... The surface high becomes centered offshore during the day, while upper level ridge builds towards our area from the west. Southern New England gets into return low level SW flow which will begin to bring warmer and eventually more humid air into region. Mostly sunny skies expected, mainly from diurnal cumulus but could see a few higher deck clouds as well. Temperatures rise well into the 80s across much of the area. Exception will be along south coastal MA/RI, where highs in the 70s to near 80 are expected. Expecting an eventual sea breeze development along east coastal MA, but may take into midday/early afternoon to get going and overcome SW flow. Tuesday night... Surface high pressure centered offshore and light SW return flow continues. Upper ridge axis extends over New England. This will be a slightly warmer and more humid night, with lows in the 60s. Could see some patchy valley fog once more, otherwise mostly clear skies expected. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Big Picture... Longwave pattern shows steady heights through the week followed by building heights off the Atlantic Sunday and Monday. Shortwave scale shows an upper ridge with axis over New England Wednesday, shifting southeast Thursday and Friday. Shortwave over the Upper Midwest Wednesday moves into Eastern Canada and sweeps a weak shortwave across New England Friday night. Subtropical high over the Atlantic builds Sunday and Monday while another shortwave approaches from the west on Monday. General model agreement Wednesday to Friday, but uncertainty for Saturday and Sunday. Both show the Friday night cold front stalling to our south. Both the 12Z GFS and ECMWF show dry weather Saturday followed by a wave moving up the front spreading showers into our area Sunday. Earlier runs showed that wave moving past with wet weather Saturday followed by dry weather Sunday. All show high pressure and dry weather Monday. Low confidence as to which will be right for the weekend. We have chosen to compromise between the two camps for now and allow the next couple of runs provide clearer information. Details... Wednesday through Friday... High pressure offshore with a developing southwest flow over the region. This will bring in increasing dew points through the period. Temperatures aloft also increase with 850-equivalent temps 16-17C Wednesday increasing to 18-20C Thursday and Friday. Airmass also becomes increasingly unstable each day with LIs near zero in the CT Valley Wednesday but with limited cloud moisture, then sub-zero LIs across much of the area Thursday and at least part of Friday. Based on this, expect hot temps during this period with max temps either side of 90 Wednesday, and 90-95 Thursday and Friday. Dew points climb to around 70 by Friday morning so humidity levels will be at least noticeable and eventually oppressive. There is a small chance of a thunderstorm in far western MA Wednesday. Thunderstorms more likely Thursday afternoon through Friday. One concern...the GFS and EC both rush precipitation through on Friday morning, while maintaining southwest winds most areas until Friday evening. Perhaps this is focusing showers on a pre-frontal trough and keeping the main front dry. Temps aloft stay warm through the afternoon supporting the idea of a later cold fropa. We massaged the available grid data to keep chance pops into mid afternoon. Specific timing of convection is probably questionable this far out, with the important idea being that there will be precipitation during some part of Friday. Saturday-Sunday-Monday... Much uncertainty in the forecast and forecast data at this time. As noted above, the 12z GFS and EC show a low pressure wave passing us on Sunday with showers while much of the forecast grid data shows showers on Saturday and dry on Sunday. Previous model suites also went with wet weather on Saturday. We have hand-edited our database to show chance pops both days. Expect later model runs will resolve this timing to one day or the other. High pressure brings drier seasonable weather on Monday. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Overnight...High confidence. VFR with mostly clear skies. Local MVFR/IFR possible overnight in patchy valley fog, as well as a possibility for patchy stratus/fog overnight along south coastal MA/southern RI. Tuesday and Tuesday night...High confidence. VFR, with local MVFR possible Tuesday night in patchy valley fog once again. Prevailing S/SW winds Tue which should prevent sea breeze development along E MA coast. KBOS TAF...High confidence. VFR. SW flow Tue should be just strong enough to prevent sea breeze from coming onshore. KBDL TAF...High confidence. VFR. Outlook /Wednesday through Saturday/... Wednesday through Friday... Moderate Confidence. VFR. Areas if late night/early morning IFR in fog. Scattered MVFR/IFR in afternoon and evening showers/thunderstorms, mainly Thursday and Friday. Winds becoming southwest much of the period. Saturday... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England through tonight, and becomes centered offshore during Tuesday. Light and variable wind becomes prevailing SW later tonight and Tuesday, except for local sea breezes redeveloping on Tuesday. Outlook /Wednesday through Saturday/... Moderate confidence. Winds below 25 knots through the period. Seas mainly below 5 feet, although there is potential for brief 5 foot seas on the outer waters Thursday night and Friday. Winds becoming southwest for most of the period. Areas of poor visibility in overnight and morning fog. Scattered showers/thunderstorms mainly Thursday and Friday. Low confidence on showers for Saturday. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...WTB/NMB NEAR TERM...JWD SHORT TERM...NMB LONG TERM...WTB AVIATION...WTB/NMB/JWD MARINE...WTB/NMB
Area Forecast Discussion National Weather Service Albany NY 945 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 945 PM EDT...Mainly clear to partly cloudy skies are expected overnight with some patchy fog likely developing in river valleys. It will be cool once again tonight, with low temperatures before daybreak falling into the upper 40s to upper 50s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. This will be followed by a return ton VFR conditions for the day on Tuesday. Satellite imagery reveals few cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Skies will return to sct045 sct-bkn250 during the day on Tuesday. Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift to the south to southwest at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...KL/11 SHORT TERM...KL LONG TERM...11 AVIATION...KL/11 FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service New York NY 757 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Some slight adjustments were made to the forecast regarding the temperatures, dewpoints, and cloud coverage to better match observed trends. Otherwise, the forecast overall remains on track. High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Some initial higher coverage of cirrus clouds will decrease later this evening with the high pressure center moving closer and with some ridging aloft. Skies will further clear out overnight with high pressure and its subsidence prevailing. With increasing low level moisture and light onshore flow, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior portions of the CWA will drop into the upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. There is a moderate risk of rip current development at the Atlantic facing beaches on Tuesday. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area through Tuesday. This will result in mainly VFR conditions with southerly winds. Gradient tightens Tuesday afternoon with some of the coastal terminals increasing to around 15 kt. Patchy MVFR BR at rural airports towards sunrise. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component FCSTS can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments expected. KLGA TAF Comments: NE winds may persist through 01Z before shifting around to the S/SE. KEWR TAF Comments: No unscheduled amendments expected. KTEB TAF Comments: NE winds may persist through 01Z before shifting around to the S/SE. KHPN TAF Comments: No unscheduled amendments expected. KISP TAF Comments: No unscheduled amendments expected. .OUTLOOK FOR 00Z Wednesday through Saturday... .Tue Night-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...JM/MPS SHORT TERM...MPS LONG TERM...JC AVIATION...DW MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service Albany NY 708 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 630 PM EDT...Patchy high clouds continue to stream across portions of the region, especially from around I-90 southward. This may be at least in part in association with a jet max retreating off the New England coast, with our area within its right entrance region. This jet max is expected to translate farther off the coast this evening, and should allow its influence and associated high clouds to decrease. So, partly cloudy this evening, then becoming mostly clear overnight. Some patchy fog will likely develop in river valleys, given that mixing was not very strong/deep this afternoon, and afternoon dewpoints held in the 50s. It will be cool once again tonight, with low temperatures before daybreak falling into the 50s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. This will be followed by a return ton VFR conditions for the day on Tuesday. Satellite imagery reveals few cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Skies will return to sct045 sct-bkn250 during the day on Tuesday. Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift to the south to southwest at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...KL/11 SHORT TERM...KL LONG TERM...11 AVIATION...KL/11 FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service Albany NY 708 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 630 PM EDT...Patchy high clouds continue to stream across portions of the region, especially from around I-90 southward. This may be at least in part in association with a jet max retreating off the New England coast, with our area within its right entrance region. This jet max is expected to translate farther off the coast this evening, and should allow its influence and associated high clouds to decrease. So, partly cloudy this evening, then becoming mostly clear overnight. Some patchy fog will likely develop in river valleys, given that mixing was not very strong/deep this afternoon, and afternoon dewpoints held in the 50s. It will be cool once again tonight, with low temperatures before daybreak falling into the 50s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. This will be followed by a return ton VFR conditions for the day on Tuesday. Satellite imagery reveals few cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Skies will return to sct045 sct-bkn250 during the day on Tuesday. Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift to the south to southwest at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...KL/11 SHORT TERM...KL LONG TERM...11 AVIATION...KL/11 FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service Taunton MA 656 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build over New England tonight, and will then become centered southeast of New England during Tuesday. Heat and humidity will increase this week with the high remaining centered offshore, bringing a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... High pressure builds across the Eastern USA, including New England. A light flow region is in place, with most of the strongest winds found in sea breezes, which will shortly diminish. Satellite shows high-level cirrus across the region but settling southeast with clearing expected before midnight. Continue to expect mostly clear skies and light winds. This will encourage radiational cooling overnight which will allow temps to fall to near the dew point. Observed evening dew points are in the 50s with a few low 60s. Expect min temps in the mid 50s to low 60s. This will allow fog to form, especially in the usual fog- favored locations inland. There continues to be a low chance of some fog/low clouds along the southern coast of RI and MA as well. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Tuesday... The surface high becomes centered offshore during the day, while upper level ridge builds towards our area from the west. Southern New England gets into return low level SW flow which will begin to bring warmer and eventually more humid air into region. Mostly sunny skies expected, mainly from diurnal cumulus but could see a few higher deck clouds as well. Temperatures rise well into the 80s across much of the area. Exception will be along south coastal MA/RI, where highs in the 70s to near 80 are expected. Expecting an eventual sea breeze development along east coastal MA, but may take into midday/early afternoon to get going and overcome SW flow. Tuesday night... Surface high pressure centered offshore and light SW return flow continues. Upper ridge axis extends over New England. This will be a slightly warmer and more humid night, with lows in the 60s. Could see some patchy valley fog once more, otherwise mostly clear skies expected. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Big Picture... Longwave pattern shows steady heights through the week followed by building heights off the Atlantic Sunday and Monday. Shortwave scale shows an upper ridge with axis over New England Wednesday, shifting southeast Thursday and Friday. Shortwave over the Upper Midwest Wednesday moves into Eastern Canada and sweeps a weak shortwave across New England Friday night. Subtropical high over the Atlantic builds Sunday and Monday while another shortwave approaches from the west on Monday. General model agreement Wednesday to Friday, but uncertainty for Saturday and Sunday. Both show the Friday night cold front stalling to our south. Both the 12Z GFS and ECMWF show dry weather Saturday followed by a wave moving up the front spreading showers into our area Sunday. Earlier runs showed that wave moving past with wet weather Saturday followed by dry weather Sunday. All show high pressure and dry weather Monday. Low confidence as to which will be right for the weekend. We have chosen to compromise between the two camps for now and allow the next couple of runs provide clearer information. Details... Wednesday through Friday... High pressure offshore with a developing southwest flow over the region. This will bring in increasing dew points through the period. Temperatures aloft also increase with 850-equivilent temps 16-17C Wednesday increasing to 18-20C Thursday and Friday. Airmass also becomes increasingly unstable each day with LIs near zero in the CT Valley Wednesday but with limited cloud moisture, then sub-zero LIs across much of the area Thursday and at least part of Friday. Based on this, expect hot temps during this period with max temps either side of 90 Wednesday, and 90-95 Thursday and Friday. Dew points climb to around 70 by Friday morning so humidity levels will be at least noticeable and eventually oppressive. There is a small chance of a thunderstorm in far western MA Wednesday. Thunderstorms more likely Thursday afternoon through Friday. One concern...the GFS and EC both rush precipitation through on Friday morning, while maintaining southwest winds most areas until Friday evening. Perhaps this is focussing showers on a pre-frontal trough and keeping the main front dry. Temps aloft stay warm through the afternoon supporting the idea of a later cold fropa. We massaged the available grid data to keep chance pops into mid afternoon. Specific timing of convection is probably questionable this far out, with the important idea being that there will be precipitation during some part of Friday. Saturday-Sunday-Monday... Much uncertainty in the forecast and forecast data at this time. As noted above, the 12z GFS and EC show a low pressure wave passing us on Sunday with showers while much of the forecast grid data shows showers on Saturday and dry on Sunday. Previous model suites also went with wet weather on Saturday. We have hand-edited our database to show chance pops both days. Expect later model runs will resolve this timing to one day or the other. High pressure brings drier seasonable weather on Monday. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Tonight...High confidence. VFR with mostly clear skies. Local MVFR/IFR possible overnight in valley fog, as well as a possibility for patchy stratus/fog overnight along south coastal MA/southern RI. Tuesday and Tuesday night...High confidence. VFR, with local MVFR possible Tuesday night in valley fog. Prevailing S/SW winds Tue except sea breeze development expected along the shorelines. KBOS TAF...High confidence. VFR with light wind. Sea breeze should redevelop during Tuesday around midday. KBDL TAF...High confidence. VFR. Outlook /Wednesday through Saturday/... Wednesday through Friday... Moderate Confidence. VFR. Areas if late night/early morning IFR in fog. Scatterd MVFR/IFRin afternoon and evening showers/thunderstorms, mainly Thursday andFriday. Winds becoming southwest much of the period. Saturday... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England through tonight, and becomes centered offshore during Tuesday. Light and variable wind becomes prevailing SW later tonight and Tuesday, except for local sea breezes redeveloping on Tuesday. Outlook /Wednesday through Saturday/... Moderate confidence. Winds below 25 knots through the period. Seas mainly below 5 feet, although there is potential for brief 5 foot seas on the outer waters Thursday night and Friday. Winds becoming southwest for most of the period. Areas of poor visibility in overnight and morning fog. Scattered showers/thunderstorms mainly Thursday and Friday. Low confidence on showers for Saturday. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...WTB/NMB NEAR TERM...WTB/NMB SHORT TERM...NMB LONG TERM...WTB AVIATION...WTB/NMB MARINE...WTB/NMB
Area Forecast Discussion National Weather Service Albany NY 630 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 630 PM EDT...Patchy high clouds continue to stream across portions of the region, especially from around I-90 southward. This may be at least in part in association with a jet max retreating off the New England coast, with our area within its right entrance region. This jet max is expected to translate farther off the coast this evening, and should allow its influence and associated high clouds to decrease. So, partly cloudy this evening, then becoming mostly clear overnight. Some patchy fog will likely develop in river valleys, given that mixing was not very strong/deep this afternoon, and afternoon dewpoints held in the 50s. It will be cool once again tonight, with low temperatures before daybreak falling into the 50s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. Satellite imagery reveals few-sct cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift from the southerly direction at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...KL/11 SHORT TERM...KL LONG TERM...11 AVIATION...KL/BGM/JPV FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service New York NY 610 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Skies will clear out tonight. With increasing low level moisture and light winds, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior portions of the CWA will drop into the upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. There is a moderate risk of rip current development at the Atlantic facing beaches on Tuesday. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /22Z MONDAY THROUGH SATURDAY/... Seabreeze finally making steady progress north and should pass through KLGA, KEWR, and KTEB in the next hour, possibly two hours. Otherwise, high pressure builds over the terminals through the overnight. Fair weather cumulus with bases around 4000-5000 ft will diminish by early this evening VFR overnight with light winds. Perhaps some MVFR VIS in BR at rural airports towards sunrise. VFR continues for Tuesday with southerly flow. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component FCSTS can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments expected. KLGA TAF Comments: High confidence of seabreeze passage by 00Z. KEWR TAF Comments: High confidence of seabreeze passage by 00Z. KTEB TAF Comments: Moderate to high confidence of seabreeze passage by 00Z. KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 18Z Tuesday through Saturday... .Tue AFTN-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the Morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...MPS SHORT TERM...MPS LONG TERM...JC AVIATION...Tongue/DW MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service Albany NY 421 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 410 PM EDT, patchy high clouds continue to stream across portions of the region, especially from around I-90 southward. This may be at least in part in association with a jet max retreating off the New England coast, with our area within its right entrance region. This jet max is expected to translate farther off the coast this evening, and should allow its influence and associated high clouds to decrease. So, partly cloudy this evening, then becoming mostly clear overnight. Some patchy fog will likely develop in river valleys, given that mixing was not very strong/deep this afternoon, and afternoon dewpoints held in the 50s. It will be cool once again tonight, with low temperatures before daybreak falling into the 50s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. Satellite imagery reveals few-sct cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift from the southerly direction at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...KL SHORT TERM...KL LONG TERM...11 AVIATION...KL/BGM/JPV FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service Taunton MA 403 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build over New England tonight, and will then become centered southeast of New England during Tuesday. Heat and humidity will increase this week with the high remaining centered offshore, bringing a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 4 PM Update... Surface high pressure continues to move across our area this evening and overnight. Lingering patchy diurnal cumulus dissipate leaving mostly clear skies with some cirrus. The light to calm winds, mainly clear skies, and dry airmass will help lows fall back into the mid and upper 50s inland and to the lower 60s near the coast. There may be some patchy valley fog inland, and there is a low chance of some patchy fog/stratus along south coastal MA and southern RI. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Tuesday... The surface high becomes centered offshore during the day, while upper level ridge builds towards our area from the west. Southern New England gets into return low level SW flow which will begin to bring warmer and eventually more humid air into region. Mostly sunny skies expected, mainly from diurnal cumulus but could see a few higher deck clouds as well. Temperatures rise well into the 80s across much of the area. Exception will be along south coastal MA/RI, where highs in the 70s to near 80 are expected. Expecting an eventual sea breeze development along east coastal MA, but may take into midday/early afternoon to get going and overcome SW flow. Tuesday night... Surface high pressure centered offshore and light SW return flow continues. Upper ridge axis extends over New England. This will be a slightly warmer and more humid night, with lows in the 60s. Could see some patchy valley fog once more, otherwise mostly clear skies expected. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Big Picture... Longwave pattern shows steady heights through the week followed by building heights off the Atlantic Sunday and Monday. Shortwave scale shows an upper ridge with axis over New England Wednesday, shifting southeast Thursday and Friday. Shortwave over the Upper Midwest Wednesday moves into Eastern Canada and sweeps a weak shortwave across New England Friday night. Subtropical high over the Atlantic builds Sunday and Monday while another shortwave approaches from the west on Monday. General model agreement Wednesday to Friday, but uncertainty for Saturday and Sunday. Both show the Friday night cold front stalling to our south. Both the 12Z GFS and ECMWF show dry weather Saturday followed by a wave moving up the front spreading showers into our area Sunday. Earlier runs showed that wave moving past with wet weather Saturday followed by dry weather Sunday. All show high pressure and dry weather Monday. Low confidence as to which will be right for the weekend. We have chosen to compromise between the two camps for now and allow the next couple of runs provide clearer information. Details... Wednesday through Friday... High pressure offshore with a developing southwest flow over the region. This will bring in increasing dew points through the period. Temperatures aloft also increase with 850-equivilent temps 16-17C Wednesday increasing to 18-20C Thursday and Friday. Airmass also becomes increasingly unstable each day with LIs near zero in the CT Valley Wednesday but with limited cloud moisture, then sub-zero LIs across much of the area Thursday and at least part of Friday. Based on this, expect hot temps during this period with max temps either side of 90 Wednesday, and 90-95 Thursday and Friday. Dew points climb to around 70 by Friday morning so humidity levels will be at least noticeable and eventually oppressive. There is a small chance of a thunderstorm in far western MA Wednesday. Thunderstorms more likely Thursday afternoon through Friday. One concern...the GFS and EC both rush precipitation through on Friday morning, while maintaining southwest winds most areas until Friday evening. Perhaps this is focussing showers on a pre-frontal trough and keeping the main front dry. Temps aloft stay warm through the afternoon supporting the idea of a later cold fropa. We massaged the available grid data to keep chance pops into mid afternoon. Specific timing of convection is probably questionable this far out, with the important idea being that there will be precipitation during some part of Friday. Saturday-Sunday-Monday... Much uncertainty in the forecast and forecast data at this time. As noted above, the 12z GFS and EC show a low pressure wave passing us on Sunday with showers while much of the forecast grid data shows showers on Saturday and dry on Sunday. Previous model suites also went with wet weather on Saturday. We have hand-edited our database to show chance pops both days. Expect later model runs will resolve this timing to one day or the other. High pressure brings drier seasonable weather on Monday. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 20Z Update... This evening...High confidence. VFR conditions expected through this evening. Overall winds light and variable across the interior. East coastal MA sea breeze lingers thru early evening. Potential for a south coastal MA/RI sea breeze developing briefly late today. Overnight...High confidence. VFR, but local MVFR/IFR possible tonight in valley fog, as well as a possibility for patchy stratus/fog overnight along south coastal MA/southern RI. Tuesday and Tuesday night...High confidence. VFR, with local MVFR possible Tuesday night in valley fog. Prevailing S/SW winds Tue except sea breeze development expected along the shorelines. KBOS TAF...High confidence. VFR. Weak seabreeze lingers into early this evening. Sea breeze should redevelop during Tuesday around midday. KBDL TAF...High confidence. VFR. Outlook /Wednesday through Saturday/... Wednesday through Friday... Moderate Confidence. VFR. Areas if late night/early morning IFR in fog. Scatterd MVFR/IFRin afternoon and evening showers/thunderstorms, mainly Thursday andFriday. Winds becoming southwest much of the period. Saturday... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England through tonight, and becomes centered offshore during Tuesday. Light and variable wind becomes prevailing SW later tonight and Tuesday, except for local sea breezes redeveloping on Tuesday. Outlook /Wednesday through Saturday/... Moderate confidence. Winds below 25 knots through the period. Seas mainly below 5 feet, although there is potential for brief 5 foot seas on the outer waters Thursday night and Friday. Winds becoming southwest for most of the period. Areas of poor visibility in overnight and morning fog. Scattered showers/thunderstorms mainly Thursday and Friday. Low confidence on showers for Saturday. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...WTB/NMB NEAR TERM...NMB SHORT TERM...NMB LONG TERM...WTB AVIATION...WTB/NMB MARINE...WTB/NMB
Area Forecast Discussion National Weather Service New York NY 357 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Skies will clear out tonight. With increasing low level moisture and light winds, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior portions of the CWA will drop into the upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... High pressure builds over the terminals through the overnight. Fair weather cumulus with bases around 4500 ft will diminish by late AFTN (22Z). Northerly winds will eventually shift around to S late this AFTN into the evening as sea breezes move inland from the Atlantic and CT coasts. VFR overnight with light winds. Perhaps some MVFR VIS in BR at rural airports towards sunrise. VFR continues for Tuesday with southern flow. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component FCSTS can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: Sea Breeze has moved south of the airport causing a wind shift to the northeast. SFC winds eventually become south...but there is low confidence in the timing of this. It could be as late as 00Z. KLGA TAF Comments: No long expect the seabreeze to reach the field this evening. KEWR TAF Comments: A lot of variability in direction the rest of the AFTN. With the Sea Breeze having dissipated...winds should stay more NE into the evening. KTEB TAF Comments: No unscheduled amendments expected KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 18Z Tuesday through Saturday... .Tue AFTN-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly AFTN TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the Morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...MPS SHORT TERM...MPS LONG TERM...JC AVIATION...Tongue MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service Taunton MA 354 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build over New England tonight, and will then become centered southeast of New England during Tuesday. Heat and humidity will increase this week with the high remaining centered offshore, bringing a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 4 PM Update... Surface high pressure continues to move across our area this evening and overnight. Lingering patchy diurnal cumulus dissipate leaving mostly clear skies with some cirrus. The light to calm winds, mainly clear skies, and dry airmass will help lows fall back into the mid and upper 50s inland and to the lower 60s near the coast. There may be some patchy valley fog inland, and there is a low chance of some patchy fog/stratus along south coastal MA and southern RI. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Tuesday... The surface high becomes centered offshore during the day, while upper level ridge builds towards our area from the west. Southern New England gets into return low level SW flow which will begin to bring warmer and eventually more humid air into region. Mostly sunny skies expected, mainly from diurnal cumulus but could see a few higher deck clouds as well. Temperatures rise well into the 80s across much of the area. Exception will be along south coastal MA/RI, where highs in the 70s to near 80 are expected. Expecting an eventual sea breeze development along east coastal MA, but may take into midday/early afternoon to get going and overcome SW flow. Tuesday night... Surface high pressure centered offshore and light SW return flow continues. Upper ridge axis extends over New England. This will be a slightly warmer and more humid night, with lows in the 60s. Could see some patchy valley fog once more, otherwise mostly clear skies expected. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Highlights... * Becoming hot and humid late in the week. * Scattered thunderstorms will likely affect the region late Thu and Fri. * Low confidence forecast for the weekend. May have more showers on Sat. OVERALL PICTURE... Upper flow across North America becomes more zonal for a time this coming week. Fairly high confidence of hot temperatures and increasing humidity for the middle and latter part of the week. Have a risk of approaching Heat Advisory criteria on Thursday if dewpoints reach at least 70. Shortwave trof rotating about Hudson Bay vortex and associated surface front approaches southern New England Thursday night. The timing of this feature will be critical as to threat of strong to severe thunderstorms. Model consensus would seem to suggest that the front may pass through southern New England Friday morning or early afternoon, not diurnally optimal for convection. Confidence is relatively low for the weekend. May not be as dry as originally thought since flow aloft remains cyclonic and from the WSW or SW. Also, both the 00Z GFS and ECMWF operational runs suggest a frontal wave on Saturday. DETAILS... Wed...Temperatures will likely reach mid 80s to lower 90s. Cannot rule out isolated thunderstorm over the western higher terrain areas but expect that most, if not all, of region remains dry. Thu...Operational models have ensemble support for a hot/humid day. H850 temperatures will likely rise to at least around 18C and will likely see all but the south coast and highest terrain areas reach 90 to 95. Sufficient instability may exist for scattered pulse late afternoon/evening thunderstorms in the western zones. As the surface front or prefrontal trough approaches, convection may persist into the night for a time across the western zones. Fri...Upper short wave trof and associated surface front crosses the region. Timing is critical with regard to convective potential. Model consensus for now would seem to have the frontal boundary making it to the coast by midday or early afternoon, too soon to tap into diurnal heating. However, Friday is still 5 days away and so cannot be all that confident on timing details. There looks to be sufficient bulk shear to support organized storms if the instability is sufficient. Expect max temperatures to be a few degrees lower than Thursday due to increased cloudiness. Nevertheless, many locations are expected to reach into the lower 90s with dewpoints in the upper 60s to near 70. Next weekend...Confidence is relatively low at this time regarding next Saturday and Sunday. Both the GFS and ECMWF operational runs depict the broad upper trof axis to be west of the area and even hint at a frontal wave passing through or just SE of the area on Saturday. Have raised POPs and sky cover some for Saturday as a consequence. Also, lowered temperatures along the coastal plain a tad as well due to potential for more clouds and possibly onshore flow. If a surface wave forms more as per the GFS, then temperatures would likely be cooler and rainfall steadier. On the other hand, the ECMWF might keep some of southern New England in the warm sector and more convectively active. It is just too soon to be able to nail down specifics this far out. Have opted for POPs below chance for Sunday as looks for now that drier air should infiltrate the region from the west. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 20Z Update... This evening...High confidence. VFR conditions expected through this evening. Overall winds light and variable across the interior. East coastal MA sea breeze lingers thru early evening. Potential for a south coastal MA/RI sea breeze developing briefly late today. Overnight...High confidence. VFR, but local MVFR/IFR possible tonight in valley fog, as well as a possibility for patchy stratus/fog overnight along south coastal MA/southern RI. Tuesday and Tuesday night...High confidence. VFR, with local MVFR possible Tuesday night in valley fog. Prevailing S/SW winds Tue except sea breeze development expected along the shorelines. KBOS TAF...High confidence. VFR. Weak seabreeze lingers into early this evening. Sea breeze should redevelop during Tuesday around midday. KBDL TAF...High confidence. VFR. Outlook /Wednesday through Saturday/...High confidence. Wednesday through Thursday morning...Generally VFR except areas of MVFR/IFR in fog along the south coast. Thursday afternoon through Friday...Generally VFR but areas of MVFR cigs/vsbys in vicinity of scattered showers and thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England through tonight, and becomes centered offshore during Tuesday. Light and variable wind becomes prevailing SW later tonight and Tuesday, except for local sea breezes redeveloping on Tuesday. Outlook /Wednesday through Saturday/...High confidence. Relatively light wind fields are expected and seas should generally remain below 5 feet across all waters. There will be areas of late night and early morning fog, especially along the south coastal waters during this time period. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...NMB/JWD/Thompson NEAR TERM...NMB SHORT TERM...NMB LONG TERM...Thompson AVIATION...NMB/JWD/Thompson MARINE...NMB/JWD/Thompson
Area Forecast Discussion National Weather Service New York NY 330 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Skies will clear out tonight. With increasing low level moisture and light winds, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior portions of the CWA will drop into the upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... High pressure builds over the terminals through the overnight. Fair weather cumulus with bases around 4500 ft will diminish by late AFTN (22Z). Northerly winds will shift around to S this AFTN as sea breezes move inland from the Atlantic and CT coasts. VFR overnight with light winds. Perhaps some MVFR VIS in BR at rural airports towards sunrise. VFR continues for Tuesday with southern flow. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component FCSTS can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: High confidence in SFC winds becoming solidly south as the Sea Breeze works inland. KLGA TAF Comments: Wind shift from Sea Breeze could be as late as 00Z. KEWR TAF Comments: A lot of variability in direction the rest of the AFTN. High confidence in speeds of less than 10 KT as direction settles to SE by 22-23Z. KTEB TAF Comments: No unscheduled amendments expected KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 18Z Tuesday through Saturday... .Tue AFTN-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly AFTN TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the Morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...MPS SHORT TERM...MPS LONG TERM...JC AVIATION...Tongue MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service Taunton MA 216 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build over New England today, resulting in clearing skies and more seasonable temperatures. Heat and humidity will increase this week as the high becomes centered offshore and brings a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 215 PM Update... Surface high pressure continues to build over our area this afternoon, and low level moisture has been more steadily eroding. The lower clouds have been clearing from north to south between noon and 2 pm, leaving partly sunny skies across northern and central MA. Mostly cloudy skies remained across northern CT and southeast MA, due to the parting stratocumulus deck as well as a cirrus deck passing thru the area. Expect to see a continued decrease in clouds across southern New England during the remainder of this afternoon. Some locales across northern MA and the Connecticut River Valley in MA/CT will manage to warm into the upper 70s and low 80s. Elsewhere across the region thinking temps will max out in the low to mid 70s due to the later thinning of the cloud deck, and the sea breeze along east coastal MA and developing sea breeze along the south coast. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... High pressure builds over southern New England tonight. Light winds, clear skies, and a dry airmass will help lows fall back into the 50s inland (where we may see some patchy valley fog) and to the lower 60s near coast. As the high becomes centered offshore Tuesday, we get into return SW flow which will begin to bring warmer (and eventually more humid) air into region. Highs will top out well into 80s (except 70s near South Coast) if not around 90 in parts of CT and Merrimack Valleys. Some of the models (00z GFS and 21z SREF in particular) try to bring showers/storms into southern New England Tue afternoon, as moisture is drawn up from the mid Atlantic states and interacts with a weak surface trough. We are not buying into this wetter solution given axis of 500 mb ridge to our W with larger scale subsidence present over region. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Highlights... * Becoming hot and humid late in the week. * Scattered thunderstorms will likely affect the region late Thu and Fri. * Low confidence forecast for the weekend. May have more showers on Sat. OVERALL PICTURE... Upper flow across North America becomes more zonal for a time this coming week. Fairly high confidence of hot temperatures and increasing humidity for the middle and latter part of the week. Have a risk of approaching Heat Advisory criteria on Thursday if dewpoints reach at least 70. Shortwave trof rotating about Hudson Bay vortex and associated surface front approaches southern New England Thursday night. The timing of this feature will be critical as to threat of strong to severe thunderstorms. Model consensus would seem to suggest that the front may pass through southern New England Friday morning or early afternoon, not diurnally optimal for convection. Confidence is relatively low for the weekend. May not be as dry as originally thought since flow aloft remains cyclonic and from the WSW or SW. Also, both the 00Z GFS and ECMWF operational runs suggest a frontal wave on Saturday. DETAILS... Wed...Temperatures will likely reach mid 80s to lower 90s. Cannot rule out isolated thunderstorm over the western higher terrain areas but expect that most, if not all, of region remains dry. Thu...Operational models have ensemble support for a hot/humid day. H850 temperatures will likely rise to at least around 18C and will likely see all but the south coast and highest terrain areas reach 90 to 95. Sufficient instability may exist for scattered pulse late afternoon/evening thunderstorms in the western zones. As the surface front or prefrontal trough approaches, convection may persist into the night for a time across the western zones. Fri...Upper short wave trof and associated surface front crosses the region. Timing is critical with regard to convective potential. Model consensus for now would seem to have the frontal boundary making it to the coast by midday or early afternoon, too soon to tap into diurnal heating. However, Friday is still 5 days away and so cannot be all that confident on timing details. There looks to be sufficient bulk shear to support organized storms if the instability is sufficient. Expect max temperatures to be a few degrees lower than Thursday due to increased cloudiness. Nevertheless, many locations are expected to reach into the lower 90s with dewpoints in the upper 60s to near 70. Next weekend...Confidence is relatively low at this time regarding next Saturday and Sunday. Both the GFS and ECMWF operational runs depict the broad upper trof axis to be west of the area and even hint at a frontal wave passing through or just SE of the area on Saturday. Have raised POPs and sky cover some for Saturday as a consequence. Also, lowered temperatures along the coastal plain a tad as well due to potential for more clouds and possibly onshore flow. If a surface wave forms more as per the GFS, then temperatures would likely be cooler and rainfall steadier. On the other hand, the ECMWF might keep some of southern New England in the warm sector and more convectively active. It is just too soon to be able to nail down specifics this far out. Have opted for POPs below chance for Sunday as looks for now that drier air should infiltrate the region from the west. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 18Z TAF Update... This afternoon/evening...Moderate confidence. MVFR cigs lingering along southern RI and far southeast MA expected to improve to VFR by 20Z. Otherwise, high confidence VFR for the remainder of this afternoon and evening as ceilings lift and clouds decrease in coverage. N winds will be quite light this afternoon, in some cases light and variable. East coastal MA sea breeze lingers thru the remainder of today, with a south coastal MA/RI sea breeze developing thru 21Z. Overnight...High confidence. VFR, but local MVFR/IFR possible tonight in valley fog, as well as possibility for patchy stratus/fog overnight along south coastal MA/southern RI. Tuesday and Tuesday night...High confidence. VFR, with local MVFR possible Tuesday night in valley fog. Prevailing S/SW winds Tue except sea breeze development expected along the shorelines. KBOS TAF...High confidence. VFR. Weak seabreeze thru the remainder of today. Sea breeze should redevelop during Tuesday around midday. KBDL TAF...High confidence. VFR. Outlook /Wednesday through Friday/...High confidence. Wednesday through Thursday morning...Generally VFR except areas of MVFR/IFR in fog along the south coast. Thursday afternoon through Friday...Generally VFR but areas of MVFR cigs/vsbys in vicinity of scattered showers and thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England today. Light N/NE flow except for local sea breezes lingering into this evening. SW flow gets underway Tue as high becomes centered offshore. Outlook /Tuesday Night through Friday/...High confidence. Relatively light wind fields are expected and seas should generally remain below 5 feet across all waters. There will be areas of late night and early morning fog, especially along the south coastal waters during this time period. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...JWD/Thompson NEAR TERM...NMB/JWD/Thompson SHORT TERM...JWD LONG TERM...Thompson AVIATION...NMB/JWD/Thompson MARINE...NMB/JWD/Thompson
Area Forecast Discussion National Weather Service New York NY 207 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure settles over the region today and moves offshore Tuesday into Wednesday. A slow moving cold front will approach from Wednesday night into Thursday, then pass east on Friday. Another frontal system may pass through on Saturday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... High pressure continues to build in from the west. Clouds associated with a weak mid-level shortwave will also continue to erode going through the afternoon as heights aloft increase and the shortwave departs. Generally partly to mostly sunny skies for the rest of the afternoon. With weak flow, afternoon sea breezes will develop near the coast and slowly push inland. Sea breezes may struggle to make it into NE NJ and the Lower Hudson Valley. High temperatures will be in the upper 70s to the lower 80s. Coolest conditions near the immediate coast and across eastern Long Island and southeast Connecticut where more cloud cover will reside. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... Tranquil conditions and mostly clear skies are expected tonight as the surface high and building ridging aloft dominate. The high will move offshore on Tuesday, but the ridge axis will still be located to the west of the region. Warmer air begins to move around the offshore high with 850 HPA temperatures increasing 2C to 4C from Monday. However, increasing southerly flow off the Atlantic around the offshore high will likely allow temperatures to only warm to near normal levels for this time of year. Highs in the middle 80s are forecast away from the coast, with readings closer to 80 near the coast due to the onshore flow. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... High pressure at the surface will slowly pass off the Mid Atlantic coast Tue night. Models show some moisture return on the back side of the sfc high, perhaps a weak shortwave trough moving through the mean upper ridge which will also be passing to the east at that time. GFS likely too aggressive with moisture return and lift, and sided toward drier ECMWF/NAM ideas, with only isolated PoP from NYC west late day Wed into Wed night. A broad upper trough will then become established from the northern Plains to the Northeast later this week. A surface cold front will still be well to the NW on Thu, but expect scattered showers/tstms to develop inland Thu afternoon invof a pre-frontal trough as a mid level shortwave approaches, drifting toward the coast late day and at night. With very warm/moist low levels, S low level flow and NW flow aloft, would expect some potential for severe wx, but coverage could ultimately be limited by a mid level capping inversion if the 00Z GFs is correct. The cold front will slowly approach on Friday, with only slight chance PoP at most as deeper moisture will be shunted to the east. Fri could be the hottest day of the week, with lower/mid 90s except at south facing coastlines, and potential for the heat index to touch 100 in urban NE NJ. This front should move east by evening, then latest model/ensemble guidance indicates potential for another frontal system to quickly follow for Sat. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... High pressure builds over the terminals this AFTN. Fair weather cumulus with bases around 4500 ft will diminish by late AFTN (21Z). Northerly winds will shift around to S this AFTN as sea breezes develop. VFR overnight with perhaps some MVFR VIS in BR at rural airports towards sunrise and light winds. VFR continues for Tuesday with southern flow. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component fcsts can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: High confidence in southerly SFC wind for INTL departure bank. KLGA TAF Comments: Wind shift from Sea Breeze could be as late as 21Z. KEWR TAF Comments: High confidence in SE winds for this AFTN at less than 10 KT. KTEB TAF Comments: No unscheduled amendments expected KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 18Z Tuesday through Saturday... .Tue AFTN-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly AFTN TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the Morning. .Sat...VFR. && .MARINE... High pressure settles over the waters through the middle of the week with a cold front approaching late in the week. Winds and seas will remain below SCA levels through the period. && .HYDROLOGY... No significant widespread precipitation expected through the middle of the week. Locally heavy rainfall is possible in any thunderstorms that develop on Thursday, possibly also on Saturday. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...Goodman/DS NEAR TERM...MPS SHORT TERM...DS LONG TERM...Goodman AVIATION...Tongue MARINE...Goodman/DS HYDROLOGY...Goodman/DS
Area Forecast Discussion National Weather Service Albany NY 133 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system for mid week. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1230 PM EDT, the combination of high clouds, and some lingering lower clouds has kept skies partly to mostly cloudy across the SE Catskills, mid Hudson Valley region and NW CT. Skies have become mostly sunny further N and W. We expect the overall trend for sky cover to become mostly sunny across the region by mid to late afternoon. Temperatures should continue rising, reaching highs of around 80 in many valley areas by 5 or 6 PM, with 70s for most higher terrain. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Heat and humidity return. Ridging will continue to build in. The surface high will begin to shift offshore on Tuesday with a southerly return flow developing. Aloft the ridge axis is forecast to crest over the region late Tuesday night/Wednesday morning with the axis shifting off the seaboard during the day. In the meantime, a stacked low pressure system will be on the gradual approach. Deep southwest flow will develop between the departing ridge and the approaching trough. Heat and humidity will be in the rise and will be very noticeably on Wednesday. 850 mb temperatures are forecast to rise to 16 to 18 degrees Celsius on Wednesday. Highs Tuesday are expected to be in the upper 70s to upper 80s with dew points rising into the upper 50s to mid 60s. Dew points will continue to rise Tuesday night into Wednesday with widespread mid to upper 60s anticipated. These values combined with high temperatures expected to top out in mainly on the 80s to lower 90s with result in heat indices in the upper 80s to upper 90s. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. As the atmosphere warms up and becomes increasingly more humid and unstable the threat of convection will be in the rise. With only subtle height fall expected Wednesday and upper level support remaining well to the west have slight chance pops across the local area for the afternoon hours. However, the chances for convection will continue Wednesday night as the upper trough and low pressure system`s cold front move into the Great Lakes region. Better chances will be west of the Hudson River Valley. The Storm Prediction Center has the region under a general thunderstorm outlook. Storms will be capable of locally heavy rainfall as precipitable water values are forecast to rise to 1.5+ inches. && .LONG TERM /THURSDAY THROUGH MONDAY/... The period starts out on Thursday with our region still under the influence of a very warm and moist southerly flow. It will become increasingly humid, with models indicating a pre-frontal trough moving through at some point during the afternoon or evening. This trough is expected to result in scattered showers and thunderstorms. Some of the storms could be on the stronger side depending on the eventual magnitude of instability and deep layer shear. Given the anticipated above normal PWATS of +1 to +2 STDEV, heavy rainfall is likely to occur within any persistent thunderstorms. Another rather subtle boundary may move across the region on Friday, with more mainly diurnal showers and thunderstorms. Models are showing a weaker system now compared to Thursday, but with the continued warm and humid air mass in place, scattered convection looks reasonable again. It will likely remain very warm and muggy Friday. Some of the 00Z model guidance showing a wave of low pressure developing along a fairly flat and progressive upper level trough for Saturday. Some GEFS ensemble members also depicting this potential wave with some probabilities for precip as well, so will raise pops to 30 percent to account for this possibility. This potential system should exit the region by Sunday with drier weather to close out the weekend. Overall, temperatures look to "cool" closer to normal values during the upcoming weekend, with somewhat of a reprieve in humidity levels as well. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. Satellite imagery reveals few-sct cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift from the southerly direction at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 80 to near 100 percent tonight. Minimum values Tuesday afternoon are forecast to be generally 40 to 50 percent south of Interstate 90 and 35 to 45 percent north of Interstate 90. Light northerly winds today will diminish tonight with a southerly flow developing Tuesday at generally less than 10 mph. && .HYDROLOGY... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/KL/BGM SHORT TERM...IAA LONG TERM...JPV AVIATION...BGM/JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service Albany NY 133 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system for mid week. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1230 PM EDT, the combination of high clouds, and some lingering lower clouds has kept skies partly to mostly cloudy across the SE Catskills, mid Hudson Valley region and NW CT. Skies have become mostly sunny further N and W. We expect the overall trend for sky cover to become mostly sunny across the region by mid to late afternoon. Temperatures should continue rising, reaching highs of around 80 in many valley areas by 5 or 6 PM, with 70s for most higher terrain. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Heat and humidity return. Ridging will continue to build in. The surface high will begin to shift offshore on Tuesday with a southerly return flow developing. Aloft the ridge axis is forecast to crest over the region late Tuesday night/Wednesday morning with the axis shifting off the seaboard during the day. In the meantime, a stacked low pressure system will be on the gradual approach. Deep southwest flow will develop between the departing ridge and the approaching trough. Heat and humidity will be in the rise and will be very noticeably on Wednesday. 850 mb temperatures are forecast to rise to 16 to 18 degrees Celsius on Wednesday. Highs Tuesday are expected to be in the upper 70s to upper 80s with dew points rising into the upper 50s to mid 60s. Dew points will continue to rise Tuesday night into Wednesday with widespread mid to upper 60s anticipated. These values combined with high temperatures expected to top out in mainly on the 80s to lower 90s with result in heat indices in the upper 80s to upper 90s. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. As the atmosphere warms up and becomes increasingly more humid and unstable the threat of convection will be in the rise. With only subtle height fall expected Wednesday and upper level support remaining well to the west have slight chance pops across the local area for the afternoon hours. However, the chances for convection will continue Wednesday night as the upper trough and low pressure system`s cold front move into the Great Lakes region. Better chances will be west of the Hudson River Valley. The Storm Prediction Center has the region under a general thunderstorm outlook. Storms will be capable of locally heavy rainfall as precipitable water values are forecast to rise to 1.5+ inches. && .LONG TERM /THURSDAY THROUGH MONDAY/... The period starts out on Thursday with our region still under the influence of a very warm and moist southerly flow. It will become increasingly humid, with models indicating a pre-frontal trough moving through at some point during the afternoon or evening. This trough is expected to result in scattered showers and thunderstorms. Some of the storms could be on the stronger side depending on the eventual magnitude of instability and deep layer shear. Given the anticipated above normal PWATS of +1 to +2 STDEV, heavy rainfall is likely to occur within any persistent thunderstorms. Another rather subtle boundary may move across the region on Friday, with more mainly diurnal showers and thunderstorms. Models are showing a weaker system now compared to Thursday, but with the continued warm and humid air mass in place, scattered convection looks reasonable again. It will likely remain very warm and muggy Friday. Some of the 00Z model guidance showing a wave of low pressure developing along a fairly flat and progressive upper level trough for Saturday. Some GEFS ensemble members also depicting this potential wave with some probabilities for precip as well, so will raise pops to 30 percent to account for this possibility. This potential system should exit the region by Sunday with drier weather to close out the weekend. Overall, temperatures look to "cool" closer to normal values during the upcoming weekend, with somewhat of a reprieve in humidity levels as well. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. Satellite imagery reveals few-sct cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift from the southerly direction at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 80 to near 100 percent tonight. Minimum values Tuesday afternoon are forecast to be generally 40 to 50 percent south of Interstate 90 and 35 to 45 percent north of Interstate 90. Light northerly winds today will diminish tonight with a southerly flow developing Tuesday at generally less than 10 mph. && .HYDROLOGY... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/KL/BGM SHORT TERM...IAA LONG TERM...JPV AVIATION...BGM/JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service New York NY 1244 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure settles over the region today and moves offshore Tuesday into Wednesday. A slow moving cold front will approach from Wednesday night into Thursday, then pass east on Friday. Another frontal system may pass through on Saturday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... High pressure continues to build in from the west. Clouds associated with a weak mid-level shortwave will also continue to erode going through the afternoon as heights aloft increase and the shortwave departs. Generally partly to mostly sunny skies for the rest of the afternoon. With weak flow, afternoon sea breezes will develop near the coast and slowly push inland. Sea breezes may struggle to make it into NE NJ and the Lower Hudson Valley. High temperatures will be in the upper 70s to the lower 80s. Coolest conditions near the immediate coast and across eastern Long Island and southeast Connecticut where more cloud cover will reside. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... Tranquil conditions and mostly clear skies are expected tonight as the surface high and building ridging aloft dominate. The high will move offshore on Tuesday, but the ridge axis will still be located to the west of the region. Warmer air begins to move around the offshore high with 850 HPA temperatures increasing 2C to 4C from Monday. However, increasing southerly flow off the Atlantic around the offshore high will likely allow temperatures to only warm to near normal levels for this time of year. Highs in the middle 80s are forecast away from the coast, with readings closer to 80 near the coast due to the onshore flow. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... High pressure at the surface will slowly pass off the Mid Atlantic coast Tue night. Models show some moisture return on the back side of the sfc high, perhaps a weak shortwave trough moving through the mean upper ridge which will also be passing to the east at that time. GFS likely too aggressive with moisture return and lift, and sided toward drier ECMWF/NAM ideas, with only isolated PoP from NYC west late day Wed into Wed night. A broad upper trough will then become established from the northern Plains to the Northeast later this week. A surface cold front will still be well to the NW on Thu, but expect scattered showers/tstms to develop inland Thu afternoon invof a pre-frontal trough as a mid level shortwave approaches, drifting toward the coast late day and at night. With very warm/moist low levels, S low level flow and NW flow aloft, would expect some potential for severe wx, but coverage could ultimately be limited by a mid level capping inversion if the 00Z GFs is correct. The cold front will slowly approach on Friday, with only slight chance PoP at most as deeper moisture will be shunted to the east. Fri could be the hottest day of the week, with lower/mid 90s except at south facing coastlines, and potential for the heat index to touch 100 in urban NE NJ. This front should move east by evening, then latest model/ensemble guidance indicates potential for another frontal system to quickly follow for Sat. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... High pressure builds over the terminals this AFTN. Fair weather cumulus with bases around 4000 ft will diminish by late AFTN (21Z). Northerly winds will shift around to S-SE this AFTN as sea breezes develop. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component fcsts can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: High confidence in southerly SFC wind for INTL departure bank. KLGA TAF Comments: Wind shift from Sea Breeze could be an hour or so sooner than FCST. KEWR TAF Comments: Wind shift to SE may occur +/- an hour so of FCST. The afternoon KEWR haze potential forecast is green...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 14Z Tuesday through Friday... .Tue-Wed...VFR. .Thu-Fri...Scattered to isolated AFTN showers/tstms possible with local MVFR conds. && .MARINE... High pressure settles over the waters through the middle of the week with a cold front approaching late in the week. Winds and seas will remain below SCA levels through the period. && .HYDROLOGY... No significant widespread precipitation expected through the middle of the week. Locally heavy rainfall is possible in any thunderstorms that develop on Thursday, possibly also on Saturday. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...Goodman/DS NEAR TERM...MPS SHORT TERM...DS LONG TERM...Goodman AVIATION...Tongue MARINE...Goodman/DS HYDROLOGY...Goodman/DS
Area Forecast Discussion National Weather Service Albany NY 1238 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system for mid week. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1230 PM EDT, the combination of high clouds, and some lingering lower clouds has kept skies partly to mostly cloudy across the SE Catskills, mid Hudson Valley region and NW CT. Skies have become mostly sunny further N and W. We expect the overall trend for sky cover to become mostly sunny across the region by mid to late afternoon. Temperatures should continue rising, reaching highs of around 80 in many valley areas by 5 or 6 PM, with 70s for most higher terrain. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Heat and humidity return. Ridging will continue to build in. The surface high will begin to shift offshore on Tuesday with a southerly return flow developing. Aloft the ridge axis is forecast to crest over the region late Tuesday night/Wednesday morning with the axis shifting off the seaboard during the day. In the meantime, a stacked low pressure system will be on the gradual approach. Deep southwest flow will develop between the departing ridge and the approaching trough. Heat and humidity will be in the rise and will be very noticeably on Wednesday. 850 mb temperatures are forecast to rise to 16 to 18 degrees Celsius on Wednesday. Highs Tuesday are expected to be in the upper 70s to upper 80s with dew points rising into the upper 50s to mid 60s. Dew points will continue to rise Tuesday night into Wednesday with widespread mid to upper 60s anticipated. These values combined with high temperatures expected to top out in mainly on the 80s to lower 90s with result in heat indices in the upper 80s to upper 90s. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. As the atmosphere warms up and becomes increasingly more humid and unstable the threat of convection will be in the rise. With only subtle height fall expected Wednesday and upper level support remaining well to the west have slight chance pops across the local area for the afternoon hours. However, the chances for convection will continue Wednesday night as the upper trough and low pressure system`s cold front move into the Great Lakes region. Better chances will be west of the Hudson River Valley. The Storm Prediction Center has the region under a general thunderstorm outlook. Storms will be capable of locally heavy rainfall as precipitable water values are forecast to rise to 1.5+ inches. && .LONG TERM /THURSDAY THROUGH SUNDAY/... The period starts out on Thursday with our region still under the influence of a very warm and moist southerly flow. It will become increasingly humid, with models indicating a pre-frontal trough moving through at some point during the afternoon or evening. This trough is expected to result in scattered showers and thunderstorms. Some of the storms could be on the stronger side depending on the eventual magnitude of instability and deep layer shear. Given the anticipated above normal PWATS of +1 to +2 STDEV, heavy rainfall is likely to occur within any persistent thunderstorms. Another rather subtle boundary may move across the region on Friday, with more mainly diurnal showers and thunderstorms. Models are showing a weaker system now compared to Thursday, but with the continued warm and humid air mass in place, scattered convection looks reasonable again. It will likely remain very warm and muggy Friday. Some of the 00Z model guidance showing a wave of low pressure developing along a fairly flat and progressive upper level trough for Saturday. Some GEFS ensemble members also depicting this potential wave with some probabilities for precip as well, so will raise pops to 30 percent to account for this possibility. This potential system should exit the region by Sunday with drier weather to close out the weekend. Overall, temperatures look to "cool" closer to normal values during the upcoming weekend, with somewhat of a reprieve in humidity levels as well. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals today into tonight. Only scattered diurnal cumulus clouds will be around this afternoon with high pressure building in. Clear skies and light winds tonight will likely lead to some radiation fog at KGFL/KPSF after 06Z Tuesday. Occasional IFR conditions look probable. Potential fog development more uncertain at KALB/KPOU, so will leave out mention for now. Winds will be light and variable, becoming N-NW around 5 kt later this morning. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 80 to near 100 percent tonight. Minimum values Tuesday afternoon are forecast to be generally 40 to 50 percent south of Interstate 90 and 35 to 45 percent north of Interstate 90. Light northerly winds today will diminish tonight with a southerly flow developing Tuesday at generally less than 10 mph. && .HYDROLOGY... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/KL/BGM SHORT TERM...IAA LONG TERM...JPV AVIATION...JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service New York NY 1236 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure settles over the region today and moves offshore Tuesday into Wednesday. A slow moving cold front will approach from Wednesday night into Thursday, then pass east on Friday. Another frontal system may pass through on Saturday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Morning forecast on track. Will update hourly grids based on latest surface obs and satellite trends, but no significant changes will be made to the forecast. Otherwise...high pressure settles over the region today while a shortwave trough off the New England coast lifts into the Canadian Maritimes. Ridging aloft builds as heights rise. Lingering low level moisture across far southeastern Connecticut and eastern Long Island will be slow to erode with partly to mostly cloudy skies forecast into the early afternoon before some clearing takes place. The rest of the area will see partly to mostly sunny skies through the day. With weak flow, afternoon sea breezes will develop near the coast and slowly push inland. Sea breezes may struggle to make it into NE NJ and the Lower Hudson Valley. High temperatures will be in the upper 70s to the lower 80s. Coolest conditions near the immediate coast and across eastern Long Island and southeast Connecticut where more cloud cover will reside. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... Tranquil conditions and mostly clear skies are expected tonight as the surface high and building ridging aloft dominate. The high will move offshore on Tuesday, but the ridge axis will still be located to the west of the region. Warmer air begins to move around the offshore high with 850 HPA temperatures increasing 2C to 4C from Monday. However, increasing southerly flow off the Atlantic around the offshore high will likely allow temperatures to only warm to near normal levels for this time of year. Highs in the middle 80s are forecast away from the coast, with readings closer to 80 near the coast due to the onshore flow. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... High pressure at the surface will slowly pass off the Mid Atlantic coast Tue night. Models show some moisture return on the back side of the sfc high, perhaps a weak shortwave trough moving through the mean upper ridge which will also be passing to the east at that time. GFS likely too aggressive with moisture return and lift, and sided toward drier ECMWF/NAM ideas, with only isolated PoP from NYC west late day Wed into Wed night. A broad upper trough will then become established from the northern Plains to the Northeast later this week. A surface cold front will still be well to the NW on Thu, but expect scattered showers/tstms to develop inland Thu afternoon invof a pre-frontal trough as a mid level shortwave approaches, drifting toward the coast late day and at night. With very warm/moist low levels, S low level flow and NW flow aloft, would expect some potential for severe wx, but coverage could ultimately be limited by a mid level capping inversion if the 00Z GFs is correct. The cold front will slowly approach on Friday, with only slight chance PoP at most as deeper moisture will be shunted to the east. Fri could be the hottest day of the week, with lower/mid 90s except at south facing coastlines, and potential for the heat index to touch 100 in urban NE NJ. This front should move east by evening, then latest model/ensemble guidance indicates potential for another frontal system to quickly follow for Sat. && .AVIATION /16Z MONDAY THROUGH FRIDAY/... High pressure builds over the terminals this AFTN. Fair weather cumulus with bases around 4000 ft will diminish by late AFTN (21Z). Northerly winds will shift around to S-SE this AFTN as sea breezes develop. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component fcsts can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: High confidence in southerly SFC wind for INTL departure bank. KLGA TAF Comments: Wind shift from Sea Breeze could be an hour or so sooner than FCST. KEWR TAF Comments: Wind shift to SE may occur +/- an hour so of FCST. The afternoon KEWR haze potential forecast is green...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 14Z Tuesday through Friday... .Tue-Wed...VFR. .Thu-Fri...Scattered to isolated AFTN showers/tstms possible with local MVFR conds. && .MARINE... High pressure settles over the waters through the middle of the week with a cold front approaching late in the week. Winds and seas will remain below SCA levels through the period. && .HYDROLOGY... No significant widespread precipitation expected through the middle of the week. Locally heavy rainfall is possible in any thunderstorms that develop on Thursday, possibly also on Saturday. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...Goodman/DS NEAR TERM...MPS SHORT TERM...DS LONG TERM...Goodman AVIATION...Tongue MARINE...Goodman/DS HYDROLOGY...Goodman/DS
Area Forecast Discussion National Weather Service Albany NY 1025 AM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1020 AM...Low stratus has eroded rather quickly and being replaced by CU/SC with a canopy of higher CI/CS advecting across the entire region. While this may have slowed down the diurnal temperature climb a bit, expectations are for a partly-mostly sunny day with terrain based cumulus clouds. Per the 12Z sounding, rather stable exists up to H700 and per mixing layer heights, forecast highs look good with no changes needed at this time. Prev Disc... Heights will rise as ridging builds in at all levels of the atmosphere today. Have variable cloudy skies across the area as higher level clouds stream in from northwest and have some lingering stratus from overnight. Will have partly to mostly sunny skies today. Light northerly flow across the area with seasonable temperatures expected along with comfortable dew points mainly in the 50s. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Heat and humidity return. Ridging will continue to build in. The surface high will begin to shift offshore on Tuesday with a southerly return flow developing. Aloft the ridge axis is forecast to crest over the region late Tuesday night/Wednesday morning with the axis shifting off the seaboard during the day. In the meantime, a stacked low pressure system will be on the gradual approach. Deep southwest flow will develop between the departing ridge and the approaching trough. Heat and humidity will be in the rise and will be very noticeably on Wednesday. 850 mb temperatures are forecast to rise to 16 to 18 degrees Celsius on Wednesday. Highs Tuesday are expected to be in the upper 70s to upper 80s with dew points rising into the upper 50s to mid 60s. Dew points will continue to rise Tuesday night into Wednesday with widespread mid to upper 60s anticipated. These values combined with high temperatures expected to top out in mainly on the 80s to lower 90s with result in heat indices in the upper 80s to upper 90s. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. As the atmosphere warms up and becomes increasingly more humid and unstable the threat of convection will be in the rise. With only subtle height fall expected Wednesday and upper level support remaining well to the west have slight chance pops across the local area for the afternoon hours. However, the chances for convection will continue Wednesday night as the upper trough and low pressure system`s cold front move into the Great Lakes region. Better chances will be west of the Hudson River Valley. The Storm Prediction Center has the region under a general thunderstorm outlook. Storms will be capable of locally heavy rainfall as precipitable water values are forecast to rise to 1.5+ inches. && .LONG TERM /THURSDAY THROUGH SUNDAY/... The period starts out on Thursday with our region still under the influence of a very warm and moist southerly flow. It will become increasingly humid, with models indicating a pre-frontal trough moving through at some point during the afternoon or evening. This trough is expected to result in scattered showers and thunderstorms. Some of the storms could be on the stronger side depending on the eventual magnitude of instability and deep layer shear. Given the anticipated above normal PWATS of +1 to +2 STDEV, heavy rainfall is likely to occur within any persistent thunderstorms. Another rather subtle boundary may move across the region on Friday, with more mainly diurnal showers and thunderstorms. Models are showing a weaker system now compared to Thursday, but with the continued warm and humid air mass in place, scattered convection looks reasonable again. It will likely remain very warm and muggy Friday. Some of the 00Z model guidance showing a wave of low pressure developing along a fairly flat and progressive upper level trough for Saturday. Some GEFS ensemble members also depicting this potential wave with some probabilities for precip as well, so will raise pops to 30 percent to account for this possibility. This potential system should exit the region by Sunday with drier weather to close out the weekend. Overall, temperatures look to "cool" closer to normal values during the upcoming weekend, with somewhat of a reprieve in humidity levels as well. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... VFR conditions expected across the terminals today into tonight. Only scattered diurnal cumulus clouds will be around this afternoon with high pressure building in. Clear skies and light winds tonight will likely lead to some radiation fog at KGFL/KPSF after 06Z Tuesday. Occasional IFR conditions look probable. Potential fog development more uncertain at KALB/KPOU, so will leave out mention for now. Winds will be light and variable, becoming N-NW around 5 kt later this morning. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 80 to near 100 percent tonight. Minimum values Tuesday afternoon are forecast to be generally 40 to 50 percent south of Interstate 90 and 35 to 45 percent north of Interstate 90. Light northerly winds today will diminish tonight with a southerly flow developing Tuesday at generally less than 10 mph. && .HYDROLOGY... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/BGM SHORT TERM...IAA LONG TERM...JPV AVIATION...JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service Albany NY 1025 AM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1020 AM...Low stratus has eroded rather quickly and being replaced by CU/SC with a canopy of higher CI/CS advecting across the entire region. While this may have slowed down the diurnal temperature climb a bit, expectations are for a partly-mostly sunny day with terrain based cumulus clouds. Per the 12Z sounding, rather stable exists up to H700 and per mixing layer heights, forecast highs look good with no changes needed at this time. Prev Disc... Heights will rise as ridging builds in at all levels of the atmosphere today. Have variable cloudy skies across the area as higher level clouds stream in from northwest and have some lingering stratus from overnight. Will have partly to mostly sunny skies today. Light northerly flow across the area with seasonable temperatures expected along with comfortable dew points mainly in the 50s. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Heat and humidity return. Ridging will continue to build in. The surface high will begin to shift offshore on Tuesday with a southerly return flow developing. Aloft the ridge axis is forecast to crest over the region late Tuesday night/Wednesday morning with the axis shifting off the seaboard during the day. In the meantime, a stacked low pressure system will be on the gradual approach. Deep southwest flow will develop between the departing ridge and the approaching trough. Heat and humidity will be in the rise and will be very noticeably on Wednesday. 850 mb temperatures are forecast to rise to 16 to 18 degrees Celsius on Wednesday. Highs Tuesday are expected to be in the upper 70s to upper 80s with dew points rising into the upper 50s to mid 60s. Dew points will continue to rise Tuesday night into Wednesday with widespread mid to upper 60s anticipated. These values combined with high temperatures expected to top out in mainly on the 80s to lower 90s with result in heat indices in the upper 80s to upper 90s. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. As the atmosphere warms up and becomes increasingly more humid and unstable the threat of convection will be in the rise. With only subtle height fall expected Wednesday and upper level support remaining well to the west have slight chance pops across the local area for the afternoon hours. However, the chances for convection will continue Wednesday night as the upper trough and low pressure system`s cold front move into the Great Lakes region. Better chances will be west of the Hudson River Valley. The Storm Prediction Center has the region under a general thunderstorm outlook. Storms will be capable of locally heavy rainfall as precipitable water values are forecast to rise to 1.5+ inches. && .LONG TERM /THURSDAY THROUGH SUNDAY/... The period starts out on Thursday with our region still under the influence of a very warm and moist southerly flow. It will become increasingly humid, with models indicating a pre-frontal trough moving through at some point during the afternoon or evening. This trough is expected to result in scattered showers and thunderstorms. Some of the storms could be on the stronger side depending on the eventual magnitude of instability and deep layer shear. Given the anticipated above normal PWATS of +1 to +2 STDEV, heavy rainfall is likely to occur within any persistent thunderstorms. Another rather subtle boundary may move across the region on Friday, with more mainly diurnal showers and thunderstorms. Models are showing a weaker system now compared to Thursday, but with the continued warm and humid air mass in place, scattered convection looks reasonable again. It will likely remain very warm and muggy Friday. Some of the 00Z model guidance showing a wave of low pressure developing along a fairly flat and progressive upper level trough for Saturday. Some GEFS ensemble members also depicting this potential wave with some probabilities for precip as well, so will raise pops to 30 percent to account for this possibility. This potential system should exit the region by Sunday with drier weather to close out the weekend. Overall, temperatures look to "cool" closer to normal values during the upcoming weekend, with somewhat of a reprieve in humidity levels as well. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... VFR conditions expected across the terminals today into tonight. Only scattered diurnal cumulus clouds will be around this afternoon with high pressure building in. Clear skies and light winds tonight will likely lead to some radiation fog at KGFL/KPSF after 06Z Tuesday. Occasional IFR conditions look probable. Potential fog development more uncertain at KALB/KPOU, so will leave out mention for now. Winds will be light and variable, becoming N-NW around 5 kt later this morning. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 80 to near 100 percent tonight. Minimum values Tuesday afternoon are forecast to be generally 40 to 50 percent south of Interstate 90 and 35 to 45 percent north of Interstate 90. Light northerly winds today will diminish tonight with a southerly flow developing Tuesday at generally less than 10 mph. && .HYDROLOGY... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/BGM SHORT TERM...IAA LONG TERM...JPV AVIATION...JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service Taunton MA 1009 AM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build over New England today, resulting in clearing skies and more seasonable temperatures. Heat and humidity will increase this week as the high becomes centered offshore and brings a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 1000 AM Update... Sufficient trapped low level moisture remained over southern New England this morning for clouds to develop and linger. Still expect this low level moisture to scour out over the course of the day, but clearing across the area will likely take several more hours. Radar showing spotty light returns across eastern MA and RI, and as far west as the Worcester hills. Have added patchy light drizzle to the forecast thru midday as well. Forecast highs look on track, but we will need the anticipated decrease in clouds over the next few hours in order to achieve those highs. So at this time not adjusting forecast highs, but will need to monitor. 300 AM Update... Last of showers were over coastal waters SE of Nantucket and were heading farther offshore. Wide range in conditions across region with partial clearing working into lower CT Valley and outer Cape Cod while clouds remain socked in elsewhere, and it`s foggy across central MA, NE CT, and parts of E MA where rain fell last evening. Weak surface low was passing well south of New England which has maintained light N flow. There is a lot of low level moisture trapped beneath subsidence inversion, so clouds/patchy fog will hang around through daybreak, before clearing begins during morning. Some of the higher-res models (most notably HRRR, RAP, and NAM) show some light precipitation early this morning, primarily in E MA. This appears to be spotty drizzle due to deeper marine layer. Since cloud heights are not all that low in this area right now, will probably leave mention out of forecast. Question for today is how fast does clearing occur? RAP forecast soundings show reasonable trend, with much of interior breaking out 12z-14z and coastal areas a bit later, more like 14z-18z. This looks like one of those situations where low clouds erode on edges, as opposed to clearing taking place from W to E, so it`s possible some areas away from coast (E of CT River) take longer than expected to clear out. Gradient remains weak today so expect coastal sea breezes to develop later this morning and early this afternoon. Forecast highs in 70s look reasonable based upon model 2-meter temperatures. Should get to around 80 in the CT and Merrimack Valleys. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... High pressure builds over southern New England tonight. Light winds, clear skies, and a dry airmass will help lows fall back into the 50s inland (where we may see some patchy valley fog) and to the lower 60s near coast. As the high becomes centered offshore Tuesday, we get into return SW flow which will begin to bring warmer (and eventually more humid) air into region. Highs will top out well into 80s (except 70s near South Coast) if not around 90 in parts of CT and Merrimack Valleys. Some of the models (00z GFS and 21z SREF in particular) try to bring showers/storms into southern New England Tue afternoon, as moisture is drawn up from the mid Atlantic states and interacts with a weak surface trough. We are not buying into this wetter solution given axis of 500 mb ridge to our W with larger scale subsidence present over region. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Highlights... * Becoming hot and humid late in the week. * Scattered thunderstorms will likely affect the region late Thu and Fri. * Low confidence forecast for the weekend. May have more showers on Sat. OVERALL PICTURE... Upper flow across North America becomes more zonal for a time this coming week. Fairly high confidence of hot temperatures and increasing humidity for the middle and latter part of the week. Have a risk of approaching Heat Advisory criteria on Thursday if dewpoints reach at least 70. Shortwave trof rotating about Hudson Bay vortex and associated surface front approaches southern New England Thursday night. The timing of this feature will be critical as to threat of strong to severe thunderstorms. Model consensus would seem to suggest that the front may pass through southern New England Friday morning or early afternoon, not diurnally optimal for convection. Confidence is relatively low for the weekend. May not be as dry as originally thought since flow aloft remains cyclonic and from the WSW or SW. Also, both the 00Z GFS and ECMWF operational runs suggest a frontal wave on Saturday. DETAILS... Wed...Temperatures will likely reach mid 80s to lower 90s. Cannot rule out isolated thunderstorm over the western higher terrain areas but expect that most, if not all, of region remains dry. Thu...Operational models have ensemble support for a hot/humid day. H850 temperatures will likely rise to at least around 18C and will likely see all but the south coast and highest terrain areas reach 90 to 95. Sufficient instability may exist for scattered pulse late afternoon/evening thunderstorms in the western zones. As the surface front or prefrontal trough approaches, convection may persist into the night for a time across the western zones. Fri...Upper short wave trof and associated surface front crosses the region. Timing is critical with regard to convective potential. Model consensus for now would seem to have the frontal boundary making it to the coast by midday or early afternoon, too soon to tap into diurnal heating. However, Friday is still 5 days away and so cannot be all that confident on timing details. There looks to be sufficient bulk shear to support organized storms if the instability is sufficient. Expect max temperatures to be a few degrees lower than Thursday due to increased cloudiness. Nevertheless, many locations are expected to reach into the lower 90s with dewpoints in the upper 60s to near 70. Next weekend...Confidence is relatively low at this time regarding next Saturday and Sunday. Both the GFS and ECMWF operational runs depict the broad upper trof axis to be west of the area and even hint at a frontal wave passing through or just SE of the area on Saturday. Have raised POPs and sky cover some for Saturday as a consequence. Also, lowered temperatures along the coastal plain a tad as well due to potential for more clouds and possibly onshore flow. If a surface wave forms more as per the GFS, then temperatures would likely be cooler and rainfall steadier. On the other hand, the ECMWF might keep some of southern New England in the warm sector and more convectively active. It is just too soon to be able to nail down specifics this far out. Have opted for POPs below chance for Sunday as looks for now that drier air should infiltrate the region from the west. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 06Z TAF Update... Today...Moderate confidence. 14Z update... Areas of MVFR ceilings should persist until 15Z-18Z, especially across RI and eastern MA. Otherwise, becoming VFR as ceilings lift and clouds decrease in coverage. N/NE winds will be quite light and so should give way to coastal sea breezes around midday or early this afternoon. Tonight and Tuesday...High confidence. VFR, but local MVFR/IFR possible in valley fog. Light winds tonight will give way to S/SW winds Tue. KBOS TAF...Moderate confidence. MVFR ceilings persist until 15-16Z, then VFR expected. Light N/NE flow gives way to weak sea breeze around 16z. KBDL TAF...Moderate confidence. Ceilings may briefly go to MVFR during late this morning, otherwise VFR conditions forecast. Outlook /Tuesday Night through Friday/...High confidence. Tuesday night through Thursday morning...Generally VFR except areas of MVFR/IFR in fog along the south coast. Thursday afternoon through Friday...Generally VFR but areas of MVFR cigs/vsbys in vicinity of scattered showers and thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England today. Light N/NE flow gives way to local sea breezes later this morning and early this afternoon. SW flow gets underway Tue as high becomes centered offshore. Outlook /Tuesday Night through Friday/...High confidence. Relatively light wind fields are expected and seas should generally remain below 5 feet across all waters. There will be areas of late night and early morning fog, especially along the south coastal waters during this time period. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...JWD/Thompson NEAR TERM...NMB/JWD/Thompson SHORT TERM...JWD LONG TERM...Thompson AVIATION...NMB/JWD/Thompson MARINE...JWD/Thompson Area Forecast Discussion National Weather Service New York NY 1140 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure moves offshore today and will continue to remain in control through Wednesday. A prefrontal trough approaches Wednesday night and moves through Thursday night into Friday. A cold front moves through the area Friday night. High pressure builds behind the front Saturday. Another frontal system approaches for Saturday night into Sunday night. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Ridging continues to build aloft today as surface high pressure sets up off the middle Atlantic coast. Cirrus spilling over the ridge is thin as seen on satellite. Convective fair weather cumulus have formed over NJ as of 14Z as the convective temperature has been reached. This cumulus will go BKN at times with subsidence aloft causing the cumulus to spread. Overall, still a mostly sunny day. Winds around the high will increase out of the south preventing temperatures near the coast from rising above the lower 80s. For the New York City metro and the interior, temperatures warm to normal levels for this time of year in the middle 80s. There is a moderate risk of rip current development at the Atlantic facing beaches today - particularly late this afternoon as southerly flow increases along with wave height. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... Dew points will be on the rise tonight with continued southerly flow. However, there should be enough of a pressure gradient to keep winds from going completely calm. NAM12, NAM4KM, and SREF BUFKIT profiles support this, so have not included any mention of patchy fog. Upper ridge axis moves over the region Wednesday morning and then continues east of the area through the day. Capping is noted on model soundings around 500 hPa as the region is still in close proximity to the ridge axis. This should prevent any convection from developing, although shortwave energy over the Ohio Valley begins to approach late in the day. Have continued the thinking from the previous forecast package for a slight chance of a shower or storm drifting into the NW interior late in the afternoon. Warmer air continues to be transported around the offshore high on Wednesday. 850 hPa temperatures warm 2C to 4C from those on Tuesday. Forecast highs are in the middle and upper 80s for the city and for inland location, and the lower 80s near the coast. It will also feel more humid as dew points rise into the middle and upper 60s. Heat indices could briefly touch 90 degrees in the afternoon for the NYC metro and across the interior. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... High pressure and an upper ridge axis will be moving east of the area late Wednesday afternoon into Wednesday evening. The area will then be under the influence of an upper trough into Monday as weak shortwave and associated vorts rotate through the trough. Meanwhile at the surface, as high pressure exits Wednesday evening a prefrontal trough moves into the region well ahead of a cold front. The trough moves slowly through Thursday night into Friday with the cold front passing through Friday night. As a result will have slight chance to low end chance pops Wednesday evening into Friday with the cold front likely coming through dry Friday night as the area stabilizes behind the trough. There remains some uncertainty with the timing of the shortwaves and when the best chances of precipitation will be at this time. Friday looks to be warmest day of the extended period as some clearing occurs ahead of the cold front and 850 MB temperatures near 20C. There will be a brief dry period Friday night into Saturday as upper trough weakens and surface high pressure builds. However, and stronger shortwave and vort moves through southern Canada Saturday night into Sunday with a weak surface trough developing. Will again have slight to low chance pops for Saturday night into Sunday night as there remains uncertainty with the timing and placement of the shortwaves. Monday will likely be dry with yet another shortwave possible for Monday night into Tuesday. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area tOday. VFR conditions with southerly winds through the TAF period. Winds increase to around 10-15 kt this afternoon as the gradient tightens. Occasional gusts are possible at some of the coastal terminals late this afternoon into early this evening. NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments expected. KLGA TAF Comments: No unscheduled amendments expected. KEWR TAF Comments: No unscheduled amendments expected. The afternoon KEWR haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected. KHPN TAF Comments: No unscheduled amendments expected. KISP TAF Comments: No unscheduled amendments expected. .OUTLOOK FOR 12Z Wednesday through Saturday... .Wed...VFR. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressures settles offshore today and will remain in control through Wednesday. Afternoon sea breezes may bring winds close to 20 KT on the western ocean/NY Bight waters each day. Otherwise, winds and seas will remain below advisory levels. A weak surface pressure gradient force will be across the forecast waters Wednesday night through Saturday as prefrontal trough moves through Thursday night into Friday with a cold frontal passage Friday night. Winds and seas will remain below advisory levels Wednesday night through Saturday. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...DS/MET NEAR TERM...Tongue SHORT TERM...DS LONG TERM...MET AVIATION...FEB/JMC MARINE...DS/MET HYDROLOGY...DS/MET
  [top] Area Forecast Discussion National Weather Service Taunton MA 1041 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure over New England will move offshore this afternoon, where it will remain the rest of this week, resulting in increasing heat and humidity. A cold front will introduce the risk of scattered showers and thunderstorms Thu (inland) and Fri (RI and eastern MA). More unsettled weather is possible over the weekend with a period of rain possible Saturday or Sunday. && .NEAR TERM /THROUGH TONIGHT/... Updated at 1030 AM ... Just some high level cirrus clouds across southern New England this afternoon. Temperatures were running about 2 to 3 degrees warmer than our forecast, so upped max forecast to upper 80s and even near 90 in a few spots for this afternoon...except upper 70s to near 80 at the coast. 850 mb temps warm to +16c by late afternoon. High pressure becomes centered off the coast this afternoon while an upper level ridge builds over New England. This will bring warmer SW flow to the region. Expecting the gradient to be weak enough to allow for sea breezes along eastern MA coast. && .SHORT TERM /WEDNESDAY/... Updated at 345 am. Light SW flow persists tonight as upper ridge axis extends over New England. Should also see patchy mid/high clouds from remnants of upstream convection and warm advection aloft, so lows tonight will be a few degrees higher than recent nights, mainly in 60s. Question for Wednesday is whether or not we see any convection in western New England. SW flow continues across region which will serve to stabilize increasingly warm/humid airmass in place along and SE of I-95. Farther west toward Berkshires, models show SB CAPES between 1000 and 2000 J/kg but 0-6km shear is weak (less than 20 kt) as are mid level lapse rates (less than 5C/km). In addition, 700 mb temperatures are rather warm and should act to suppress any convection. Nonetheless, it is possible we see a few showers or perhaps an isolated thunderstorm Wednesday afternoon, so included that mention across western New England. A hotter day is in store despite continued presence of mid and high clouds. Once again leaned toward MOS blend which gives highs well into 80s (but around 90 across lower CT and Merrimack Valleys and closer to 80 near the South Coast). Dewpoints should climb into 60s which will make it feel more humid, but heat indices should stay close to actual temperatures, which would be below Advisory criteria. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Updated at 345 am. Highlights ... * Risk of scattered T-storms Thu (inland) & Fri (RI & eastern MA) * Additional showers possible over the weekend * Very warm and humid Thu and Fri Synoptic Overview ... Good model agreement among ensembles and deterministic guidance regarding the large scale flow this period with east coast ridge moving offshore Wed night and replaced by long wave trough setting up over the Great Lakes Thu and Fri. Some of the guidance suggest the trough deamplifies over the weekend however broad weak mid level cyclonic flow likely lingers across New England Sat and Sun. Thus potential periods of unsettled weather in the form of scattered showers and T-storms into this weekend. Guidance/Model assessment ... As expected at this time range deterministic guidance shows large timing differences. For example...over the weekend the GFS brings another slug of moisture into the region Sat whereas the 00z EC is about 24 hrs later with system arriving Sunday. Thus given the time range here we leaned toward the GEFS and EPS ensembles to better capture the full range of possibilities in the medium and long range. Temperatures ... New 00z guidance suggesting lots of deep layer moisture around Thu and may preclude temps from being as warm as Wed. EPS probs for 90+temps Thu is considerable lower than Wed. Thus have trended temps down Thu, nonetheless still very warm with highs in the MU80s. Highs likely jump back into the 90s Fri as both ensembles and deterministic guid have 850 temps up to +18c/+19c across southern New England. Quite humid Thu and Fri with dew pts climbing to around 70 both days. Therefore a very warm and humid Thu night is expected with lows only in the upper 60s and low 70s. For the weekend northern stream trough erodes the east coast ridge a bit resulting in temps and humidity not as oppressive as Friday. Nonetheless still warm Sat/Sun and Mon with highs well into the 80s away from the ocean. Precipitation ... Looks likes greatest risk for T-storms is Thu (interior) and Fri (RI and Eastern MA). GEFS and EPS both indicate highest probs of 1000- 2000j/kg of cape are Thu (interior) and Fri (RI & eastern MA). Given moderate instability and modest jet dynamics/wind fields could be a risk for a few strong storms Thu and Fri. Also heavy rainers possible as EPS shows high probs of PWATS of 1.5 to 2.0 inches Thu into Fri. Another chance of rain over the weekend but deterministic guidance showing a large spread in timing differences. Ensembles not much help here as it appears to be a frontal wave sliding south of New England and likely too small for ensembles to resolve. Thus low confidence forecast for the weekend. Given there is a risk for showers/T-storms just about any day this period there will also be many hours of dry weather too. Thus not a complete washout. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Updated at 1030 am ... No changes to TAFs. Light southeast sea breezes along the eastern MA coast. This afternoonod through Wednesday...High confidence. VFR today with light westerly flow becoming southwest. Gradient may be just weak enough to cause a sea breeze along the eastern MA coast. May see patchy valley fog and local MVFR/IFR vsbys tonight. Widely scattered showers/tstms possible Wed afternoon, mainly near Berkshires where brief MVFR conditions are possible. KBOS TAF...High confidence VFR. Tricky forecast for winds. West to southwest flow may back to the south and perhaps go southeast for a time this afternoon. KBDL TAF...High confidence. Outlook /Wednesday Night through Saturday/... Wednesday night through Friday ... Moderate Confidence. VFR. Areas of late night/early morning IFR in fog. Scattered MVFR/IFR in afternoon and evening showers/thunderstorms, mainly Thursday and Friday. Winds becoming southwest much of the period. Saturday ... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Updated at 1030 am. Short Term /through Wednesday/...High confidence. High pressure becomes centered SE of New England and brings S/SW flow. Gradient may weaken enough to allow for onshore winds near E MA coast this afternoon, but it`s more likely winds stay S or SW. Seas may approach 5 FT on outer waters E of Cape Cod late in day Wednesday due to persistent S/SW flow. Patchy fog possible tonight into Wednesday morning on S coastal waters, but it is not expected to be dense or widespread. Outlook /Wednesday night through Saturday/ ... Moderate confidence. Persistent S-SW winds of 15 to 20 kt across the waters will result in modest seas. Vsby less than 1 nm at times in night time/morning fog and scattered T-storms. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Nocera/JWD NEAR TERM...GAF SHORT TERM...JWD LONG TERM...Nocera AVIATION...Nocera/JWD/GAF MARINE...Nocera/JWD/GAF
  [top] Area Forecast Discussion National Weather Service Albany NY 1023 AM EDT TUE JUL 12 2016 .SYNOPSIS... Heat and humidity return especially for Wednesday and Thursday. Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday with locally heavy rainfall expected. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1023 AM EDT...Morning fog/low stratus has all dissipated across the region. Meanwhile, thin, high cirrus clouds are moving into the region from the west, and these clouds look to continue to be in place through the remainder of the day. Some diurnal cumulus clouds may develop this afternoon as well, especially over the high terrain. Ridging will continue to build in aloft today with the 500 mb ridge axis expected to crest over the region by late in the day. At the surface, the high will begin to shift offshore with a southerly return flow developing. This will allow humidity levels to be higher than the past few days, with dewpoints values rising to near 60 degrees F by late today. With the upper level ridging/surface high nearby, enough subsidence will be in place to prevent any precip from developing across our area. Highs today are expected to be several degrees warmer than yesterday; mainly in the mid to upper 80s for valleys with mid- upper 70s across the higher terrain of the southern Adirondacks, eastern Catskills and southern Green Mountains. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... Hot and humid Wednesday and Thursday. Storms with locally heavy rainfall expected on Thursday. Aloft the ridge axis will begin to shift eastward overnight into Wednesday as a stacked low pressure system located over southern Manitoba moves northeastward. Deep southwest flow will develop between the departing ridge and the approaching trough which will help bring on the heat and humidity. 850 mb temperatures are still forecast to rise to 16 to 18 degrees Celsius on Wednesday and remained high through Thursday. Dew points are forecast to rise mid to upper 60s Wednesday with upper 60s to lower 70s for Thursday. Looking for highs Wednesday in the mid 80s to lower 90s and in the upper 70s to upper 80s Thursday. These temperatures combined with the high dew points will result in heat indices in the upper 80s to upper 90s both days. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. The nights will be very muggy with lows only in the mid 60s to lower 70s with dew points not far behind. The approaching system is expected weaken as the upper low opens and become incorporated in the large upper level low over Hudson`s Bay by Wednesday night. This will leave our region on the southern periphery of the longwave trough with weak short waves moving through the flow and only meager height falls across the region as the system`s cold front gradually approaches. With such a warm and humid air mass in place and possible subtle short wave moving through the flow can not rule out the threat for isolated thunderstorms Wednesday and Wednesday night. More widespread chances are expected on Thursday a as weak short wave moves through the flow. Chances for organized storms will remain to our north across far northern New York where better forcing will be present. The Storm Prediction Center has our region in the general thunderstorm outlook for both Wednesday and Thursday. Precipitable water values are forecast to rise to 1.5 to near 2 inches, which is 1-2 standard deviations above normal, so storms will be capable of locally heavy rainfall. The heavy downpours could result in some minor urban flooding of poor drainage and low lying areas. Have added mention of heavy rainfall to forecast for Thursday and will continue to have mention in our Hazardous Weather Outlook. && .LONG TERM /FRIDAY THROUGH MONDAY/... The period starts out on Friday with a cold front pushing southeastward across the area, mainly during the first half of the day. Models have come into better agreement with the timing. It will still be very warm and humid across the southern half of the area, with some locations in the Hudson Valley near Kingston and Poughkeepsie expected to exceed 90 degrees. Some modest instability and moisture in place will result in isolated to scattered convection. Best chances will be across the Adirondacks which will be closer to a short wave trough moving through northern NY. Any showers and thunderstorms should diminish Friday evening after diurnal heating is lost. Weak high pressure will then attempt to build into the region late Friday night into Saturday. However, the GFS and CMC are still depicting a wave of low pressure developing along the old frontal boundary that will stall to our south over the mid Atlantic states. The latest ECMWF has backed off on this wave despite having a slightly deeper upper level trough over the Midwest and Great Lakes. Will maintain low chance pops for Saturday, but with increasing uncertainty. Depending on the track of the area of low pressure, it could end up being cooler should the clouds/showers accompanying the low affect our region. Again, this is uncertain so will trend close to guidance which is depicting temperatures near normal. More differences in models for Sunday, with the GFS/CMC indicating weak high pressure building back in with a flatter flow pattern aloft. However, the ECMWF is showing some unsettled weather with a deeper trough moving into the Northeast. With a lingering upper level trough over the region into Monday and northwest flow aloft, widely scattered diurnal convection cannot be ruled out. Overall there is not much to indicate any strong signals, so will stay close to climo for temps/pops into early next week. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... A ridge of high pressure will remain in control of our weather today and tonight. Any leftover fog or low stratus clouds should dissipate by 12Z, with VFR conditions prevailing thereafter. Scattered diurnal cumulus clouds should develop with scattered-broken high level cirrus clouds around today too. Skies expected to be mainly clear again tonight with some passing high level cirrus clouds. With increasing low level moisture, radiation fog is likely to occur again at KGFL/KPSF with IFR/LIFR conditions possible. Fog formation less certain at KPOU but will monitor trends. A southerly breeze is expected to persist at KALB tonight, which should preclude fog development. Winds will initially be calm, then become southerly around 4-7 kt by early afternoon. Winds will become light and variable tonight, except remain southerly around 5-7 kt at KALB. Outlook... Wednesday Night: Low Operational Impact. Slight Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Low Operational Impact. Slight Chance of SHRA...TSRA. Friday Night: No Operational Impact. NO SIG WX. Saturday: Moderate Operational Impact. Chance of SHRA. && .FIRE WEATHER... Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight. Minimum values Wednesday afternoon are forecast to range from 45 to 55 percent. A southerly flow will develop today and persisting through Wednesday. && .HYDROLOGY... Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday with locally heavy rainfall expected. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. The heavy downpours could result in some minor urban flooding of poor drainage and low lying areas. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/Frugis SHORT TERM...IAA LONG TERM...JPV AVIATION...JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service Albany NY 1023 AM EDT TUE JUL 12 2016 .SYNOPSIS... Heat and humidity return especially for Wednesday and Thursday. Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday with locally heavy rainfall expected. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1023 AM EDT...Morning fog/low stratus has all dissipated across the region. Meanwhile, thin, high cirrus clouds are moving into the region from the west, and these clouds look to continue to be in place through the remainder of the day. Some diurnal cumulus clouds may develop this afternoon as well, especially over the high terrain. Ridging will continue to build in aloft today with the 500 mb ridge axis expected to crest over the region by late in the day. At the surface, the high will begin to shift offshore with a southerly return flow developing. This will allow humidity levels to be higher than the past few days, with dewpoints values rising to near 60 degrees F by late today. With the upper level ridging/surface high nearby, enough subsidence will be in place to prevent any precip from developing across our area. Highs today are expected to be several degrees warmer than yesterday; mainly in the mid to upper 80s for valleys with mid- upper 70s across the higher terrain of the southern Adirondacks, eastern Catskills and southern Green Mountains. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... Hot and humid Wednesday and Thursday. Storms with locally heavy rainfall expected on Thursday. Aloft the ridge axis will begin to shift eastward overnight into Wednesday as a stacked low pressure system located over southern Manitoba moves northeastward. Deep southwest flow will develop between the departing ridge and the approaching trough which will help bring on the heat and humidity. 850 mb temperatures are still forecast to rise to 16 to 18 degrees Celsius on Wednesday and remained high through Thursday. Dew points are forecast to rise mid to upper 60s Wednesday with upper 60s to lower 70s for Thursday. Looking for highs Wednesday in the mid 80s to lower 90s and in the upper 70s to upper 80s Thursday. These temperatures combined with the high dew points will result in heat indices in the upper 80s to upper 90s both days. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. The nights will be very muggy with lows only in the mid 60s to lower 70s with dew points not far behind. The approaching system is expected weaken as the upper low opens and become incorporated in the large upper level low over Hudson`s Bay by Wednesday night. This will leave our region on the southern periphery of the longwave trough with weak short waves moving through the flow and only meager height falls across the region as the system`s cold front gradually approaches. With such a warm and humid air mass in place and possible subtle short wave moving through the flow can not rule out the threat for isolated thunderstorms Wednesday and Wednesday night. More widespread chances are expected on Thursday a as weak short wave moves through the flow. Chances for organized storms will remain to our north across far northern New York where better forcing will be present. The Storm Prediction Center has our region in the general thunderstorm outlook for both Wednesday and Thursday. Precipitable water values are forecast to rise to 1.5 to near 2 inches, which is 1-2 standard deviations above normal, so storms will be capable of locally heavy rainfall. The heavy downpours could result in some minor urban flooding of poor drainage and low lying areas. Have added mention of heavy rainfall to forecast for Thursday and will continue to have mention in our Hazardous Weather Outlook. && .LONG TERM /FRIDAY THROUGH MONDAY/... The period starts out on Friday with a cold front pushing southeastward across the area, mainly during the first half of the day. Models have come into better agreement with the timing. It will still be very warm and humid across the southern half of the area, with some locations in the Hudson Valley near Kingston and Poughkeepsie expected to exceed 90 degrees. Some modest instability and moisture in place will result in isolated to scattered convection. Best chances will be across the Adirondacks which will be closer to a short wave trough moving through northern NY. Any showers and thunderstorms should diminish Friday evening after diurnal heating is lost. Weak high pressure will then attempt to build into the region late Friday night into Saturday. However, the GFS and CMC are still depicting a wave of low pressure developing along the old frontal boundary that will stall to our south over the mid Atlantic states. The latest ECMWF has backed off on this wave despite having a slightly deeper upper level trough over the Midwest and Great Lakes. Will maintain low chance pops for Saturday, but with increasing uncertainty. Depending on the track of the area of low pressure, it could end up being cooler should the clouds/showers accompanying the low affect our region. Again, this is uncertain so will trend close to guidance which is depicting temperatures near normal. More differences in models for Sunday, with the GFS/CMC indicating weak high pressure building back in with a flatter flow pattern aloft. However, the ECMWF is showing some unsettled weather with a deeper trough moving into the Northeast. With a lingering upper level trough over the region into Monday and northwest flow aloft, widely scattered diurnal convection cannot be ruled out. Overall there is not much to indicate any strong signals, so will stay close to climo for temps/pops into early next week. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... A ridge of high pressure will remain in control of our weather today and tonight. Any leftover fog or low stratus clouds should dissipate by 12Z, with VFR conditions prevailing thereafter. Scattered diurnal cumulus clouds should develop with scattered-broken high level cirrus clouds around today too. Skies expected to be mainly clear again tonight with some passing high level cirrus clouds. With increasing low level moisture, radiation fog is likely to occur again at KGFL/KPSF with IFR/LIFR conditions possible. Fog formation less certain at KPOU but will monitor trends. A southerly breeze is expected to persist at KALB tonight, which should preclude fog development. Winds will initially be calm, then become southerly around 4-7 kt by early afternoon. Winds will become light and variable tonight, except remain southerly around 5-7 kt at KALB. Outlook... Wednesday Night: Low Operational Impact. Slight Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Low Operational Impact. Slight Chance of SHRA...TSRA. Friday Night: No Operational Impact. NO SIG WX. Saturday: Moderate Operational Impact. Chance of SHRA. && .FIRE WEATHER... Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight. Minimum values Wednesday afternoon are forecast to range from 45 to 55 percent. A southerly flow will develop today and persisting through Wednesday. && .HYDROLOGY... Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday with locally heavy rainfall expected. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. The heavy downpours could result in some minor urban flooding of poor drainage and low lying areas. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/Frugis SHORT TERM...IAA LONG TERM...JPV AVIATION...JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service New York NY 1016 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure moves offshore today and will continue to remain in control through Wednesday. A prefrontal trough approaches Wednesday night and moves through Thursday night into Friday. A cold front moves through the area Friday night. High pressure builds behind the front Saturday. Another frontal system approaches for Saturday night into Sunday night. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Ridging continues to build aloft today as surface high pressure sets up off the middle Atlantic coast. Cirrus spilling over the ridge is thin as seen on satellite. Convective fair weather cumulus have formed over NJ as of 14Z as the convective temperature has been reached. This cumulus will go BKN at times with subsidence aloft causing the cumulus to spread. Overall, still a mostly sunny day. Winds around the high will increase out of the south preventing temperatures near the coast from rising above the lower 80s. For the New York City metro and the interior, temperatures warm to normal levels for this time of year in the middle 80s. There is a moderate risk of rip current development at the Atlantic facing beaches today - particularly late this afternoon as southerly flow increases along with wave height. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... Dew points will be on the rise tonight with continued southerly flow. However, there should be enough of a pressure gradient to keep winds from going completely calm. NAM12, NAM4KM, and SREF BUFKIT profiles support this, so have not included any mention of patchy fog. Upper ridge axis moves over the region Wednesday morning and then continues east of the area through the day. Capping is noted on model soundings around 500 hPa as the region is still in close proximity to the ridge axis. This should prevent any convection from developing, although shortwave energy over the Ohio Valley begins to approach late in the day. Have continued the thinking from the previous forecast package for a slight chance of a shower or storm drifting into the NW interior late in the afternoon. Warmer air continues to be transported around the offshore high on Wednesday. 850 hPa temperatures warm 2C to 4C from those on Tuesday. Forecast highs are in the middle and upper 80s for the city and for inland location, and the lower 80s near the coast. It will also feel more humid as dew points rise into the middle and upper 60s. Heat indices could briefly touch 90 degrees in the afternoon for the NYC metro and across the interior. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... High pressure and an upper ridge axis will be moving east of the area late Wednesday afternoon into Wednesday evening. The area will then be under the influence of an upper trough into Monday as weak shortwave and associated vorts rotate through the trough. Meanwhile at the surface, as high pressure exits Wednesday evening a prefrontal trough moves into the region well ahead of a cold front. The trough moves slowly through Thursday night into Friday with the cold front passing through Friday night. As a result will have slight chance to low end chance pops Wednesday evening into Friday with the cold front likely coming through dry Friday night as the area stabilizes behind the trough. There remains some uncertainty with the timing of the shortwaves and when the best chances of precipitation will be at this time. Friday looks to be warmest day of the extended period as some clearing occurs ahead of the cold front and 850 MB temperatures near 20C. There will be a brief dry period Friday night into Saturday as upper trough weakens and surface high pressure builds. However, and stronger shortwave and vort moves through southern Canada Saturday night into Sunday with a weak surface trough developing. Will again have slight to low chance pops for Saturday night into Sunday night as there remains uncertainty with the timing and placement of the shortwaves. Monday will likely be dry with yet another shortwave possible for Monday night into Tuesday. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area throughout the day. VFR conditions with southerly winds through the TAF period. Winds increase to around 10-15 kt this afternoon as the gradient tightens. Occasional gusts are possible at some of the coastal terminals late this afternoon into early this evening. NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments expected. KLGA TAF Comments: No unscheduled amendments expected. KEWR TAF Comments: No unscheduled amendments expected. The afternoon KEWR haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected. KHPN TAF Comments: No unscheduled amendments expected. KISP TAF Comments: No unscheduled amendments expected. .OUTLOOK FOR 12Z Wednesday through Saturday... .Wed...VFR. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressures settles offshore today and will remain in control through Wednesday. Afternoon sea breezes may bring winds close to 20 KT on the western ocean/NY Bight waters each day. Otherwise, winds and seas will remain below advisory levels. A weak surface pressure gradient force will be across the forecast waters Wednesday night through Saturday as prefrontal trough moves through Thursday night into Friday with a cold frontal passage Friday night. Winds and seas will remain below advisory levels Wednesday night through Saturday. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...DS/MET NEAR TERM...Tongue SHORT TERM...DS LONG TERM...MET AVIATION...FEB/JMC MARINE...DS/MET HYDROLOGY...DS/MET
Area Forecast Discussion National Weather Service New York NY 946 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure moves offshore today and will continue to remain in control through Wednesday. A prefrontal trough approaches Wednesday night and moves through Thursday night into Friday. A cold front moves through the area Friday night. High pressure builds behind the front Saturday. Another frontal system approaches for Saturday night into Sunday night. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Ridging continues to build aloft today as surface high pressure sets up off the middle atlantic coast. Some mid level moisture rolling over the ridge axis to the west will bring some scattered clouds this afternoon, but sky conditions should average mostly sunny through the day. Winds around the high will increase out of the south preventing temperatures near the coast from rising above the lower 80s. For the New York City metro and the interior, temperatures warm to normal levels for this time of year in the middle 80s. There is a moderate risk of rip current development at the Atlantic facing beaches today. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... Dew points will be on the rise tonight with continued southerly flow. However, there should be enough of a pressure gradient to keep winds from going completely calm. NAM12, NAM4KM, and SREF BUFKIT profiles support this, so have not included any mention of patchy fog. Upper ridge axis moves over the region Wednesday morning and then continues east of the area through the day. Capping is noted on model soundings around 500 hPa as the region is still in close proximity to the ridge axis. This should prevent any convection from developing, although shortwave energy over the Ohio Valley begins to approach late in the day. Have continued the thinking from the previous forecast package for a slight chance of a shower or storm drifting into the NW interior late in the afternoon. Warmer air continues to be transported around the offshore high on Wednesday. 850 hPa temperatures warm 2C to 4C from those on Tuesday. Forecast highs are in the middle and upper 80s for the city and for inland location, and the lower 80s near the coast. It will also feel more humid as dew points rise into the middle and upper 60s. Heat indices could briefly touch 90 degrees in the afternoon for the NYC metro and across the interior. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... High pressure and an upper ridge axis will be moving east of the area late Wednesday afternoon into Wednesday evening. The area will then be under the influence of an upper trough into Monday as weak shortwave and associated vorts rotate through the trough. Meanwhile at the surface, as high pressure exits Wednesday evening a prefrontal trough moves into the region well ahead of a cold front. The trough moves slowly through Thursday night into Friday with the cold front passing through Friday night. As a result will have slight chance to low end chance pops Wednesday evening into Friday with the cold front likely coming through dry Friday night as the area stabilizes behind the trough. There remains some uncertainty with the timing of the shortwaves and when the best chances of precipitation will be at this time. Friday looks to be warmest day of the extended period as some clearing occurs ahead of the cold front and 850 MB temperatures near 20C. There will be a brief dry period Friday night into Saturday as upper trough weakens and surface high pressure builds. However, and stronger shortwave and vort moves through southern Canada Saturday night into Sunday with a weak surface trough developing. Will again have slight to low chance pops for Saturday night into Sunday night as there remains uncertainty with the timing and placement of the shortwaves. Monday will likely be dry with yet another shortwave possible for Monday night into Tuesday. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area throughout the day. VFR conditions with southerly winds through the TAF period. Winds increase to around 10-15 kt this afternoon as the gradient tightens. Occasional gusts are possible at some of the coastal terminals late this afternoon into early this evening. NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments expected. KLGA TAF Comments: No unscheduled amendments expected. KEWR TAF Comments: No unscheduled amendments expected. The afternoon KEWR haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected. KHPN TAF Comments: No unscheduled amendments expected. KISP TAF Comments: No unscheduled amendments expected. .OUTLOOK FOR 12Z Wednesday through Saturday... .Wed...VFR. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressures settles offshore today and will remain in control through Wednesday. Afternoon sea breezes may bring winds close to 20 KT on the western ocean waters each day. Otherwise, winds and seas will remain below advisory levels. A weak surface pressure gradient force will be across the forecast waters Wednesday night through Saturday as prefrontal trough moves through Thursday night into Friday with a cold frontal passage Friday night. Winds and seas will remain below advisory levels Wednesday night through Saturday. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...DS/MET NEAR TERM...DS SHORT TERM...DS LONG TERM...MET AVIATION...FEB/JMC MARINE...DS/MET HYDROLOGY...DS/MET
Area Forecast Discussion National Weather Service New York NY 736 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure moves offshore today and will continue to remain in control through Wednesday. A prefrontal trough approaches Wednesday night and moves through Thursday night into Friday. A cold front moves through the area Friday night. High pressure builds behind the front Saturday. Another frontal system approaches for Saturday night into Sunday night. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Ridging continues to build aloft today as surface high pressure sets up off the middle atlantic coast. Some mid level moisture rolling over the ridge axis to the west will bring some scattered clouds this afternoon, but sky conditions should average mostly sunny through the day. Winds around the high will increase out of the south preventing temperatures near the coast from rising above the lower 80s. For the New York City metro and the interior, temperatures warm to normal levels for this time of year in the middle 80s. There is a moderate risk of rip current development at the Atlantic facing beaches today. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... Dew points will be on the rise tonight with continued southerly flow. However, there should be enough of a pressure gradient to keep winds from going completely calm. NAM12, NAM4KM, and SREF BUFKIT profiles support this, so have not included any mention of patchy fog. Upper ridge axis moves over the region Wednesday morning and then continues east of the area through the day. Capping is noted on model soundings around 500 hPa as the region is still in close proximity to the ridge axis. This should prevent any convection from developing, although shortwave energy over the Ohio Valley begins to approach late in the day. Have continued the thinking from the previous forecast package for a slight chance of a shower or storm drifting into the NW interior late in the afternoon. Warmer air continues to be transported around the offshore high on Wednesday. 850 hPa temperatures warm 2C to 4C from those on Tuesday. Forecast highs are in the middle and upper 80s for the city and for inland location, and the lower 80s near the coast. It will also feel more humid as dew points rise into the middle and upper 60s. Heat indices could briefly touch 90 degrees in the afternoon for the NYC metro and across the interior. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... High pressure and an upper ridge axis will be moving east of the area late Wednesday afternoon into Wednesday evening. The area will then be under the influence of an upper trough into Monday as weak shortwave and associated vorts rotate through the trough. Meanwhile at the surface, as high pressure exits Wednesday evening a prefrontal trough moves into the region well ahead of a cold front. The trough moves slowly through Thursday night into Friday with the cold front passing through Friday night. As a result will have slight chance to low end chance pops Wednesday evening into Friday with the cold front likely coming through dry Friday night as the area stabilizes behind the trough. There remains some uncertainty with the timing of the shortwaves and when the best chances of precipitation will be at this time. Friday looks to be warmest day of the extended period as some clearing occurs ahead of the cold front and 850 MB temperatures near 20C. There will be a brief dry period Friday night into Saturday as upper trough weakens and surface high pressure builds. However, and stronger shortwave and vort moves through southern Canada Saturday night into Sunday with a weak surface trough developing. Will again have slight to low chance pops for Saturday night into Sunday night as there remains uncertainty with the timing and placement of the shortwaves. Monday will likely be dry with yet another shortwave possible for Monday night into Tuesday. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area throughout the day. VFR conditions with southerly winds through the TAF period. Winds increase to around 10-15 kt this afternoon as the gradient tightens. Occasional gusts are possible at some of the coastal terminals late this afternoon into early this evening. NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments expected. KLGA TAF Comments: No unscheduled amendments expected. KEWR TAF Comments: No unscheduled amendments expected. The afternoon KEWR haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected. KHPN TAF Comments: No unscheduled amendments expected. KISP TAF Comments: No unscheduled amendments expected. .OUTLOOK FOR 06Z Wednesday through Saturday... .Tue Night-Wed...VFR. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressures settles offshore today and will remain in control through Wednesday. Afternoon sea breezes may bring winds close to 20 KT on the western ocean waters each day. Otherwise, winds and seas will remain below advisory levels. A weak surface pressure gradient force will be across the forecast waters Wednesday night through Saturday as prefrontal trough moves through Thursday night into Friday with a cold frontal passage Friday night. Winds and seas will remain below advisory levels Wednesday night through Saturday. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...DS/MET NEAR TERM...DS SHORT TERM...DS LONG TERM...MET AVIATION...FEB MARINE...DS/MET HYDROLOGY...DS/MET
Area Forecast Discussion National Weather Service Taunton MA 653 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure over New England will move offshore today resulting in a trend toward warmer and more humid weather for the remainder of the workweek. First look at the weekend appears not as hot and humid. As for precipitation...a cold front will introduce the risk of scattered showers and thunderstorms Thu (inland) and Fri (RI and eastern MA). More unsettled weather is possible over the weekend with a period of rain possible Saturday or Sunday. && .NEAR TERM /THROUGH TONIGHT/... Updated at 7 AM ... Not much change from previous forecast. Had to modify hourly temps and dew pts to better reflect current conditions. Otherwise comfortably cool temps at 7 am with readings in the 50s except low to mid 60s along the coast including the city of Boston. Any lingering patchy fog will burn off quickly. As high pressure slips offshore today winds will shift to the southwest. This combined with temps warming aloft (850 mb from +12c this morning to +16c by days end) will result in highs this afternoon jumping well into the 80s. Earlier discussion below. ===================================================================== Clear skies across region early this morning with light winds. Usual interior cool spots have dropped into 50s, and with low temperature/dewpoint spreads patchy fog has formed in the usual low lying areas. Expect any fog to quickly lift around sunrise. High pressure becomes centered off the coast today while upper ridge builds over New England. This will bring warmer SW flow to the region, although models show gradient may weaken enough to allow for sea breezes along E MA coast. Not sure that will be the case, however, since forecast soundings show potential mixing up to 830 mb this afternoon. Looks to be a situation where weak sea breeze may develop offshore but never make it onto land. In any case, plenty of sunshine is expected despite high clouds from convection in upper Midwest making trip around the top of upper ridge. Leaned toward a MOS blend which gives highs well into 80s, except upper 70s along immediate South Coast. && .SHORT TERM /WEDNESDAY/... Updated at 345 am. Light SW flow persists tonight as upper ridge axis extends over New England. Should also see patchy mid/high clouds from remnants of upstream convection and warm advection aloft, so lows tonight will be a few degrees higher than recent nights, mainly in 60s. Question for Wednesday is whether or not we see any convection in western New England. SW flow continues across region which will serve to stabilize increasingly warm/humid airmass in place along and SE of I-95. Farther west toward Berkshires, models show SB CAPES between 1000 and 2000 J/kg but 0-6km shear is weak (less than 20 kt) as are mid level lapse rates (less than 5C/km). In addition, 700 mb temperatures are rather warm and should act to suppress any convection. Nonetheless, it is possible we see a few showers or perhaps an isolated thunderstorm Wednesday afternoon, so included that mention across western New England. A hotter day is in store despite continued presence of mid and high clouds. Once again leaned toward MOS blend which gives highs well into 80s (but around 90 across lower CT and Merrimack Valleys and closer to 80 near the South Coast). Dewpoints should climb into 60s which will make it feel more humid, but heat indices should stay close to actual temperatures, which would be below Advisory criteria. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Updated at 345 am. Highlights ... * Risk of scattered T-storms Thu (inland) & Fri (RI & eastern MA) * Additional showers possible over the weekend * Very warm and humid Thu and Fri Synoptic Overview ... Good model agreement among ensembles and deterministic guidance regarding the large scale flow this period with east coast ridge moving offshore Wed night and replaced by long wave trough setting up over the Great Lakes Thu and Fri. Some of the guidance suggest the trough deamplifies over the weekend however broad weak mid level cyclonic flow likely lingers across New England Sat and Sun. Thus potential periods of unsettled weather in the form of scattered showers and T-storms into this weekend. Guidance/Model assessment ... As expected at this time range deterministic guidance shows large timing differences. For example...over the weekend the GFS brings another slug of moisture into the region Sat whereas the 00z EC is about 24 hrs later with system arriving Sunday. Thus given the time range here we leaned toward the GEFS and EPS ensembles to better capture the full range of possibilities in the medium and long range. Temperatures ... New 00z guidance suggesting lots of deep layer moisture around Thu and may preclude temps from being as warm as Wed. EPS probs for 90+temps Thu is considerable lower than Wed. Thus have trended temps down Thu, nonetheless still very warm with highs in the MU80s. Highs likely jump back into the 90s Fri as both ensembles and deterministic guid have 850 temps up to +18c/+19c across southern New England. Quite humid Thu and Fri with dew pts climbing to around 70 both days. Therefore a very warm and humid Thu night is expected with lows only in the upper 60s and low 70s. For the weekend northern stream trough erodes the east coast ridge a bit resulting in temps and humidity not as oppressive as Friday. Nonetheless still warm Sat/Sun and Mon with highs well into the 80s away from the ocean. Precipitation ... Looks likes greatest risk for T-storms is Thu (interior) and Fri (RI and Eastern MA). GEFS and EPS both indicate highest probs of 1000- 2000j/kg of cape are Thu (interior) and Fri (RI & eastern MA). Given moderate instability and modest jet dynamics/wind fields could be a risk for a few strong storms Thu and Fri. Also heavy rainers possible as EPS shows high probs of PWATS of 1.5 to 2.0 inches Thu into Fri. Another chance of rain over the weekend but deterministic guidance showing a large spread in timing differences. Ensembles not much help here as it appears to be a frontal wave sliding south of New England and likely too small for ensembles to resolve. Thus low confidence forecast for the weekend. Given there is a risk for showers/T-storms just about any day this period there will also be many hours of dry weather too. Thus not a complete washout. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Updated at 7 am ... not much change from 06z and 09z taf update. Any lingering patchy fog burns off quickly by 9 am. Today through Wednesday...High confidence. Patchy fog in low lying areas will bring local MVFR/IFR vsbys through sunrise. Otherwise VFR today with S/SW flow. Gradient appears just strong enough to prevent sea breezes along E MA coast, but winds could back to SE for a time mainly 18z-22z. May see another round of patchy valley fog and local MVFR/IFR vsbys tonight. Widely scattered showers/tstms possible Wed afternoon, mainly near Berkshires where brief MVFR conditions are possible. KBOS TAF...High confidence. SW flow should be just strong enough to prevent sea breeze from coming onshore, but winds could back to 170-180 (true) for a couple of hours between 18z and 21z. KBDL TAF...High confidence. Outlook /Wednesday Night through Saturday/... Wednesday night through Friday ... Moderate Confidence. VFR. Areas of late night/early morning IFR in fog. Scattered MVFR/IFR in afternoon and evening showers/thunderstorms, mainly Thursday and Friday. Winds becoming southwest much of the period. Saturday ... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Updated at 345 am. Short Term /through Wednesday/...High confidence. High pressure becomes centered SE of New England and brings S/SW flow. Gradient may weaken enough to allow for onshore winds near E MA coast this afternoon, but it`s more likely winds stay S or SW. Seas may approach 5 FT on outer waters E of Cape Cod late in day Wednesday due to persistent S/SW flow. Patchy fog possible tonight into Wednesday morning on S coastal waters, but is not expected to be dense or widespread. Outlook /Wednesday night through Saturday/ ... Moderate confidence. Persistent S-SW winds of 15 to 20 kt across the waters will result in modest seas. Vsby less than 1 nm at times in night time/morning fog and scattered T-storms. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Nocera/JWD NEAR TERM...Nocera/JWD SHORT TERM...JWD LONG TERM...Nocera AVIATION...Nocera/JWD MARINE...Nocera/JWD
Area Forecast Discussion National Weather Service Albany NY 645 AM EDT TUE JUL 12 2016 .SYNOPSIS... Heat and humidity return especially for Wednesday and Thursday. Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday with locally heavy rainfall expected. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Warmer today as the heat and humidity begin to return. Radiation fog mainly in the river valley locations will lift and burn off quickly this morning. Ridging will continue to build in aloft today with the 500 mb ridge axis expected to crest over the region by late in the day. At the surface, the high will begin to shift offshore with a southerly return flow developing. Highs today are expected to be several degrees warmer than yesterday; mainly in the 80s with mid-upper 70s across the higher terrain of the southern Adirondacks, eastern Catskills and southern Green Mountains. Dew points will begin to rise with as the southerly flow develops with values expected to be in the upper 50s to lower 60s by this evening. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... Hot and humid Wednesday and Thursday. Storms with locally heavy rainfall expected on Thursday. Aloft the ridge axis will begin to shift eastward overnight into Wednesday as a stacked low pressure system located over southern Manitoba moves northeastward. Deep southwest flow will develop between the departing ridge and the approaching trough which will help bring on the heat and humidity. 850 mb temperatures are still forecast to rise to 16 to 18 degrees Celsius on Wednesday and remained high through Thursday. Dew points are forecast to rise mid to upper 60s Wednesday with upper 60s to lower 70s for Thursday. Looking for highs Wednesday in the mid 80s to lower 90s and in the upper 70s to upper 80s Thursday. These temperatures combined with the high dew points will result in heat indices in the upper 80s to upper 90s both days. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. The nights will be very muggy with lows only in the mid 60s to lower 70s with dew points not far behind. The approaching system is expected weaken as the upper low opens and become incorporated in the large upper level low over Hudson`s Bay by Wednesday night. This will leave our region on the southern periphery of the longwave trough with weak short waves moving through the flow and only meager height falls across the region as the system`s cold front gradually approaches. With such a warm and humid air mass in place and possible subtle short wave moving through the flow can not rule out the threat for isolated thunderstorms Wednesday and Wednesday night. More widespread chances are expected on Thursday a as weak short wave moves through the flow. Chances for organized storms will remain to our north across far northern New York where better forcing will be present. The Storm Prediction Center has our region in the general thunderstorm outlook for both Wednesday and Thursday. Precipitable water values are forecast to rise to 1.5 to near 2 inches, which is 1-2 standard deviations above normal, so storms will be capable of locally heavy rainfall. The heavy downpours could result in some minor urban flooding of poor drainage and low lying areas. Have added mention of heavy rainfall to forecast for Thursday and will continue to have mention in our Hazardous Weather Outlook. && .LONG TERM /FRIDAY THROUGH MONDAY/... The period starts out on Friday with a cold front pushing southeastward across the area, mainly during the first half of the day. Models have come into better agreement with the timing. It will still be very warm and humid across the southern half of the area, with some locations in the Hudson Valley near Kingston and Poughkeepsie expected to exceed 90 degrees. Some modest instability and moisture in place will result in isolated to scattered convection. Best chances will be across the Adirondacks which will be closer to a short wave trough moving through northern NY. Any showers and thunderstorms should diminish Friday evening after diurnal heating is lost. Weak high pressure will then attempt to build into the region late Friday night into Saturday. However, the GFS and CMC are still depicting a wave of low pressure developing along the old frontal boundary that will stall to our south over the mid Atlantic states. The latest ECMWF has backed off on this wave despite having a slightly deeper upper level trough over the Midwest and Great Lakes. Will maintain low chance pops for Saturday, but with increasing uncertainty. Depending on the track of the area of low pressure, it could end up being cooler should the clouds/showers accompanying the low affect our region. Again, this is uncertain so will trend close to guidance which is depicting temperatures near normal. More differences in models for Sunday, with the GFS/CMC indicating weak high pressure building back in with a flatter flow pattern aloft. However, the ECMWF is showing some unsettled weather with a deeper trough moving into the Northeast. With a lingering upper level trough over the region into Monday and northwest flow aloft, widely scattered diurnal convection cannot be ruled out. Overall there is not much to indicate any strong signals, so will stay close to climo for temps/pops into early next week. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... A ridge of high pressure will remain in control of our weather today and tonight. Any leftover fog or low stratus clouds should dissipate by 12Z, with VFR conditions prevailing thereafter. Scattered diurnal cumulus clouds should develop with scattered-broken high level cirrus clouds around today too. Skies expected to be mainly clear again tonight with some passing high level cirrus clouds. With increasing low level moisture, radiation fog is likely to occur again at KGFL/KPSF with IFR/LIFR conditions possible. Fog formation less certain at KPOU but will monitor trends. A southerly breeze is expected to persist at KALB tonight, which should preclude fog development. Winds will initially be calm, then become southerly around 4-7 kt by early afternoon. Winds will become light and variable tonight, except remain southerly around 5-7 kt at KALB. Outlook... Wednesday Night: Low Operational Impact. Slight Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Low Operational Impact. Slight Chance of SHRA...TSRA. Friday Night: No Operational Impact. NO SIG WX. Saturday: Moderate Operational Impact. Chance of SHRA. && .FIRE WEATHER... Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight. Minimum values Wednesday afternoon are forecast to range from 45 to 55 percent. A southerly flow will develop today and persisting through Wednesday. && .HYDROLOGY... Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday with locally heavy rainfall expected. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. The heavy downpours could result in some minor urban flooding of poor drainage and low lying areas. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA SHORT TERM...IAA LONG TERM...JPV AVIATION...JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service Albany NY 645 AM EDT TUE JUL 12 2016 .SYNOPSIS... Heat and humidity return especially for Wednesday and Thursday. Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday with locally heavy rainfall expected. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Warmer today as the heat and humidity begin to return. Radiation fog mainly in the river valley locations will lift and burn off quickly this morning. Ridging will continue to build in aloft today with the 500 mb ridge axis expected to crest over the region by late in the day. At the surface, the high will begin to shift offshore with a southerly return flow developing. Highs today are expected to be several degrees warmer than yesterday; mainly in the 80s with mid-upper 70s across the higher terrain of the southern Adirondacks, eastern Catskills and southern Green Mountains. Dew points will begin to rise with as the southerly flow develops with values expected to be in the upper 50s to lower 60s by this evening. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... Hot and humid Wednesday and Thursday. Storms with locally heavy rainfall expected on Thursday. Aloft the ridge axis will begin to shift eastward overnight into Wednesday as a stacked low pressure system located over southern Manitoba moves northeastward. Deep southwest flow will develop between the departing ridge and the approaching trough which will help bring on the heat and humidity. 850 mb temperatures are still forecast to rise to 16 to 18 degrees Celsius on Wednesday and remained high through Thursday. Dew points are forecast to rise mid to upper 60s Wednesday with upper 60s to lower 70s for Thursday. Looking for highs Wednesday in the mid 80s to lower 90s and in the upper 70s to upper 80s Thursday. These temperatures combined with the high dew points will result in heat indices in the upper 80s to upper 90s both days. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. The nights will be very muggy with lows only in the mid 60s to lower 70s with dew points not far behind. The approaching system is expected weaken as the upper low opens and become incorporated in the large upper level low over Hudson`s Bay by Wednesday night. This will leave our region on the southern periphery of the longwave trough with weak short waves moving through the flow and only meager height falls across the region as the system`s cold front gradually approaches. With such a warm and humid air mass in place and possible subtle short wave moving through the flow can not rule out the threat for isolated thunderstorms Wednesday and Wednesday night. More widespread chances are expected on Thursday a as weak short wave moves through the flow. Chances for organized storms will remain to our north across far northern New York where better forcing will be present. The Storm Prediction Center has our region in the general thunderstorm outlook for both Wednesday and Thursday. Precipitable water values are forecast to rise to 1.5 to near 2 inches, which is 1-2 standard deviations above normal, so storms will be capable of locally heavy rainfall. The heavy downpours could result in some minor urban flooding of poor drainage and low lying areas. Have added mention of heavy rainfall to forecast for Thursday and will continue to have mention in our Hazardous Weather Outlook. && .LONG TERM /FRIDAY THROUGH MONDAY/... The period starts out on Friday with a cold front pushing southeastward across the area, mainly during the first half of the day. Models have come into better agreement with the timing. It will still be very warm and humid across the southern half of the area, with some locations in the Hudson Valley near Kingston and Poughkeepsie expected to exceed 90 degrees. Some modest instability and moisture in place will result in isolated to scattered convection. Best chances will be across the Adirondacks which will be closer to a short wave trough moving through northern NY. Any showers and thunderstorms should diminish Friday evening after diurnal heating is lost. Weak high pressure will then attempt to build into the region late Friday night into Saturday. However, the GFS and CMC are still depicting a wave of low pressure developing along the old frontal boundary that will stall to our south over the mid Atlantic states. The latest ECMWF has backed off on this wave despite having a slightly deeper upper level trough over the Midwest and Great Lakes. Will maintain low chance pops for Saturday, but with increasing uncertainty. Depending on the track of the area of low pressure, it could end up being cooler should the clouds/showers accompanying the low affect our region. Again, this is uncertain so will trend close to guidance which is depicting temperatures near normal. More differences in models for Sunday, with the GFS/CMC indicating weak high pressure building back in with a flatter flow pattern aloft. However, the ECMWF is showing some unsettled weather with a deeper trough moving into the Northeast. With a lingering upper level trough over the region into Monday and northwest flow aloft, widely scattered diurnal convection cannot be ruled out. Overall there is not much to indicate any strong signals, so will stay close to climo for temps/pops into early next week. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... A ridge of high pressure will remain in control of our weather today and tonight. Any leftover fog or low stratus clouds should dissipate by 12Z, with VFR conditions prevailing thereafter. Scattered diurnal cumulus clouds should develop with scattered-broken high level cirrus clouds around today too. Skies expected to be mainly clear again tonight with some passing high level cirrus clouds. With increasing low level moisture, radiation fog is likely to occur again at KGFL/KPSF with IFR/LIFR conditions possible. Fog formation less certain at KPOU but will monitor trends. A southerly breeze is expected to persist at KALB tonight, which should preclude fog development. Winds will initially be calm, then become southerly around 4-7 kt by early afternoon. Winds will become light and variable tonight, except remain southerly around 5-7 kt at KALB. Outlook... Wednesday Night: Low Operational Impact. Slight Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Low Operational Impact. Slight Chance of SHRA...TSRA. Friday Night: No Operational Impact. NO SIG WX. Saturday: Moderate Operational Impact. Chance of SHRA. && .FIRE WEATHER... Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight. Minimum values Wednesday afternoon are forecast to range from 45 to 55 percent. A southerly flow will develop today and persisting through Wednesday. && .HYDROLOGY... Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday with locally heavy rainfall expected. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. The heavy downpours could result in some minor urban flooding of poor drainage and low lying areas. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA SHORT TERM...IAA LONG TERM...JPV AVIATION...JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service Albany NY 448 AM EDT TUE JUL 12 2016 .SYNOPSIS... Heat and humidity return especially for Wednesday and Thursday. Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday with locally heavy rainfall expected. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Warmer today as the heat and humidity begin to return. Ridging will continue to build in aloft today with the 500 mb ridge axis expected to crest over the region by late in the day. At the surface, the high will begin to shift offshore with a southerly return flow developing. Highs today are expected to be several degrees warmer than yesterday; mainly in the 80s with mid-upper 70s across the higher terrain of the southern Adirondacks, eastern Catskills and southern Green Mountains. Dew points will begin to rise with as the southerly flow develops with values expected to be in the upper 50s to lower 60s by this evening. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... Hot and humid Wednesday and Thursday. Storms with locally heavy rainfall expected on Thursday. Aloft the ridge axis will begin to shift eastward overnight into Wednesday as a stacked low pressure system located over southern Manitoba moves northeastward. Deep southwest flow will develop between the departing ridge and the approaching trough which will help bring on the heat and humidity. 850 mb temperatures are still forecast to rise to 16 to 18 degrees Celsius on Wednesday and remained high through Thursday. Dew points are forecast to rise mid to upper 60s Wednesday with upper 60s to lower 70s for Thursday. Looking for highs Wednesday in the mid 80s to lower 90s and in the upper 70s to upper 80s Thursday. These temperatures combined with the high dew points will result in heat indices in the upper 80s to upper 90s both days. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. The nights will be very muggy with lows only in the mid 60s to lower 70s with dew points not far behind. The approaching system is expected weaken as the upper low opens and become incorporated in the large upper level low over Hudson`s Bay by Wednesday night. This will leave our region on the southern periphery of the longwave trough with weak short waves moving through the flow and only meager height falls across the region as the system`s cold front gradually approaches. With such a warm and humid air mass in place and possible subtle short wave moving through the flow can not rule out the threat for isolated thunderstorms Wednesday and Wednesday night. More widespread chances are expected on Thursday a as weak short wave moves through the flow. Chances for organized storms will remain to our north across far northern New York where better forcing will be present. The Storm Prediction Center has our region in the general thunderstorm outlook for both Wednesday and Thursday. Precipitable water values are forecast to rise to 1.5 to near 2 inches, which is 1-2 standard deviations above normal, so storms will be capable of locally heavy rainfall. The heavy downpours could result in some minor urban flooding of poor drainage and low lying areas. Have added mention of heavy rainfall to forecast for Thursday and will continue to have mention in our Hazardous Weather Outlook. && .LONG TERM /FRIDAY THROUGH MONDAY/... The period starts out on Friday with a cold front pushing southeastward across the area, mainly during the first half of the day. Models have come into better agreement with the timing. It will still be very warm and humid across the southern half of the area, with some locations in the Hudson Valley near Kingston and Poughkeepsie expected to exceed 90 degrees. Some modest instability and moisture in place will result in isolated to scattered convection. Best chances will be across the Adirondacks which will be closer to a short wave trough moving through northern NY. Any showers and thunderstorms should diminish Friday evening after diurnal heating is lost. Weak high pressure will then attempt to build into the region late Friday night into Saturday. However, the GFS and CMC are still depicting a wave of low pressure developing along the old frontal boundary that will stall to our south over the mid Atlantic states. The latest ECMWF has backed off on this wave despite having a slightly deeper upper level trough over the Midwest and Great Lakes. Will maintain low chance pops for Saturday, but with increasing uncertainty. Depending on the track of the area of low pressure, it could end up being cooler should the clouds/showers accompanying the low affect our region. Again, this is uncertain so will trend close to guidance which is depicting temperatures near normal. More differences in models for Sunday, with the GFS/CMC indicating weak high pressure building back in with a flatter flow pattern aloft. However, the ECMWF is showing some unsettled weather with a deeper trough moving into the Northeast. With a lingering upper level trough over the region into Monday and northwest flow aloft, widely scattered diurnal convection cannot be ruled out. Overall there is not much to indicate any strong signals, so will stay close to climo for temps/pops into early next week. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... High pressure in place across the region with mainly clear skies and calm winds. Some high level cirrus clouds continue to drift across the area from time to time. Fairly dry air mass in place for mid July, although radiation fog with occasional IFR conditions has already occurred at KGFL, with fog development expected at KPSF by 07Z or 08Z. Will mention any IFR in tempo groups due to some uncertainty regarding persistence of thick fog. IFR not anticipated at KALB/KPOU, but there could be some fog in the vicinity of KALB near the Mohawk River. Will mention brief MVFR vsby possible at KPOU, but thicker fog development should not occur. Any fog should dissipate by 11Z, with VFR conditions prevailing thereafter. Scattered diurnal cumulus clouds should develop with scattered-broken high level cirrus clouds around today too. Winds will be calm, then become southerly around 4-7 kt by early afternoon. Outlook... Wednesday Night: Low Operational Impact. Slight Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Low Operational Impact. Slight Chance of SHRA...TSRA. Friday Night: No Operational Impact. NO SIG WX. Saturday: Moderate Operational Impact. Chance of SHRA. && .FIRE WEATHER... Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight. Minimum values Wednesday afternoon are forecast to range from 45 to 55 percent. A southerly flow will develop today and persisting through Wednesday. && .HYDROLOGY... Fair weather is expected into early Wednesday as high pressure dominates. A slow moving cold front will be on the approach eventually crossing the region Friday. With a warm and humid air mass in place some showers and thunderstorms are expect with the storms being most numerous on Thursday with locally heavy rainfall expected. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. The heavy downpours could result in some minor urban flooding of poor drainage and low lying areas. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA SHORT TERM...IAA LONG TERM...JPV AVIATION...JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service New York NY 444 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure moves offshore today and will continue to remain in control through Wednesday. A prefrontal trough approaches Wednesday night and moves through Thursday night into Friday. A cold front moves through the area Friday night. High pressure builds behind the front Saturday. Another frontal system approaches for Saturday night into Sunday night. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Ridging continues to build aloft today as surface high pressure sets up off the middle atlantic coast. Some mid level moisture rolling over the ridge axis to the west will bring some scattered clouds this afternoon, but sky conditions should average mostly sunny through the day. Winds around the high will increase out of the south preventing temperatures near the coast from rising above the lower 80s. For the New York City metro and the interior, temperatures warm to normal levels for this time of year in the middle 80s. There is a moderate risk of rip current development at the Atlantic facing beaches today. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... Dew points will be on the rise tonight with continued southerly flow. However, there should be enough of a pressure gradient to keep winds from going completely calm. NAM12, NAM4KM, and SREF BUFKIT profiles support this, so have not included any mention of patchy fog. Upper ridge axis moves over the region Wednesday morning and then continues east of the area through the day. Capping is noted on model soundings around 500 hPa as the region is still in close proximity to the ridge axis. This should prevent any convection from developing, although shortwave energy over the Ohio Valley begins to approach late in the day. Have continued the thinking from the previous forecast package for a slight chance of a shower or storm drifting into the NW interior late in the afternoon. Warmer air continues to be transported around the offshore high on Wednesday. 850 hPa temperatures warm 2C to 4C from those on Tuesday. Forecast highs are in the middle and upper 80s for the city and for inland location, and the lower 80s near the coast. It will also feel more humid as dew points rise into the middle and upper 60s. Heat indices could briefly touch 90 degrees in the afternoon for the NYC metro and across the interior. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... High pressure and an upper ridge axis will be moving east of the area late Wednesday afternoon into Wednesday evening. The area will then be under the influence of an upper trough into Monday as weak shortwave and associated vorts rotate through the trough. Meanwhile at the surface, as high pressure exits Wednesday evening a prefrontal trough moves into the region well ahead of a cold front. The trough moves slowly through Thursday night into Friday with the cold front passing through Friday night. As a result will have slight chance to low end chance pops Wednesday evening into Friday with the cold front likely coming through dry Friday night as the area stabilizes behind the trough. There remains some uncertainty with the timing of the shortwaves and when the best chances of precipitation will be at this time. Friday looks to be warmest day of the extended period as some clearing occurs ahead of the cold front and 850 MB temperatures near 20C. There will be a brief dry period Friday night into Saturday as upper trough weakens and surface high pressure builds. However, and stronger shortwave and vort moves through southern Canada Saturday night into Sunday with a weak surface trough developing. Will again have slight to low chance pops for Saturday night into Sunday night as there remains uncertainty with the timing and placement of the shortwaves. Monday will likely be dry with yet another shortwave possible for Monday night into Tuesday. && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area throughout the day. VFR conditions with southerly winds through the TAF period. Generally light winds early this morning have veered more toward the west or southwest at some terminals, but expect these sites to return to southerly flow shortly after daybreak. The gradient tightens this afternoon with some of the coastal terminals increasing to around 15 kt. ...NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http://www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments expected. KLGA TAF Comments: No unscheduled amendments expected. KEWR TAF Comments: No unscheduled amendments expected. The afternoon KEWR haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected. KHPN TAF Comments: No unscheduled amendments expected. KISP TAF Comments: No unscheduled amendments expected. .OUTLOOK FOR 06Z Wednesday through Saturday... .Tue Night-Wed...VFR. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressures settles offshore today and will remain in control through Wednesday. Afternoon sea breezes may bring winds close to 20 KT on the western ocean waters each day. Otherwise, winds and seas will remain below advisory levels. A weak surface pressure gradient force will be across the forecast waters Wednesday night through Saturday as prefrontal trough moves through Thursday night into Friday with a cold frontal passage Friday night. Winds and seas will remain below advisory levels Wednesday night through Saturday. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...DS/MET NEAR TERM...DS SHORT TERM...DS LONG TERM...MET AVIATION...FEB MARINE...DS/MET HYDROLOGY...DS/MET
Area Forecast Discussion National Weather Service New York NY 444 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure moves offshore today and will continue to remain in control through Wednesday. A prefrontal trough approaches Wednesday night and moves through Thursday night into Friday. A cold front moves through the area Friday night. High pressure builds behind the front Saturday. Another frontal system approaches for Saturday night into Sunday night. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Ridging continues to build aloft today as surface high pressure sets up off the middle atlantic coast. Some mid level moisture rolling over the ridge axis to the west will bring some scattered clouds this afternoon, but sky conditions should average mostly sunny through the day. Winds around the high will increase out of the south preventing temperatures near the coast from rising above the lower 80s. For the New York City metro and the interior, temperatures warm to normal levels for this time of year in the middle 80s. There is a moderate risk of rip current development at the Atlantic facing beaches today. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... Dew points will be on the rise tonight with continued southerly flow. However, there should be enough of a pressure gradient to keep winds from going completely calm. NAM12, NAM4KM, and SREF BUFKIT profiles support this, so have not included any mention of patchy fog. Upper ridge axis moves over the region Wednesday morning and then continues east of the area through the day. Capping is noted on model soundings around 500 hPa as the region is still in close proximity to the ridge axis. This should prevent any convection from developing, although shortwave energy over the Ohio Valley begins to approach late in the day. Have continued the thinking from the previous forecast package for a slight chance of a shower or storm drifting into the NW interior late in the afternoon. Warmer air continues to be transported around the offshore high on Wednesday. 850 hPa temperatures warm 2C to 4C from those on Tuesday. Forecast highs are in the middle and upper 80s for the city and for inland location, and the lower 80s near the coast. It will also feel more humid as dew points rise into the middle and upper 60s. Heat indices could briefly touch 90 degrees in the afternoon for the NYC metro and across the interior. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... High pressure and an upper ridge axis will be moving east of the area late Wednesday afternoon into Wednesday evening. The area will then be under the influence of an upper trough into Monday as weak shortwave and associated vorts rotate through the trough. Meanwhile at the surface, as high pressure exits Wednesday evening a prefrontal trough moves into the region well ahead of a cold front. The trough moves slowly through Thursday night into Friday with the cold front passing through Friday night. As a result will have slight chance to low end chance pops Wednesday evening into Friday with the cold front likely coming through dry Friday night as the area stabilizes behind the trough. There remains some uncertainty with the timing of the shortwaves and when the best chances of precipitation will be at this time. Friday looks to be warmest day of the extended period as some clearing occurs ahead of the cold front and 850 MB temperatures near 20C. There will be a brief dry period Friday night into Saturday as upper trough weakens and surface high pressure builds. However, and stronger shortwave and vort moves through southern Canada Saturday night into Sunday with a weak surface trough developing. Will again have slight to low chance pops for Saturday night into Sunday night as there remains uncertainty with the timing and placement of the shortwaves. Monday will likely be dry with yet another shortwave possible for Monday night into Tuesday. && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area throughout the day. VFR conditions with southerly winds through the TAF period. Generally light winds early this morning have veered more toward the west or southwest at some terminals, but expect these sites to return to southerly flow shortly after daybreak. The gradient tightens this afternoon with some of the coastal terminals increasing to around 15 kt. ...NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http://www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments expected. KLGA TAF Comments: No unscheduled amendments expected. KEWR TAF Comments: No unscheduled amendments expected. The afternoon KEWR haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected. KHPN TAF Comments: No unscheduled amendments expected. KISP TAF Comments: No unscheduled amendments expected. .OUTLOOK FOR 06Z Wednesday through Saturday... .Tue Night-Wed...VFR. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressures settles offshore today and will remain in control through Wednesday. Afternoon sea breezes may bring winds close to 20 KT on the western ocean waters each day. Otherwise, winds and seas will remain below advisory levels. A weak surface pressure gradient force will be across the forecast waters Wednesday night through Saturday as prefrontal trough moves through Thursday night into Friday with a cold frontal passage Friday night. Winds and seas will remain below advisory levels Wednesday night through Saturday. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...DS/MET NEAR TERM...DS SHORT TERM...DS LONG TERM...MET AVIATION...FEB MARINE...DS/MET HYDROLOGY...DS/MET
Area Forecast Discussion National Weather Service New York NY 355 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure moves offshore today and will continue to remain in control through Wednesday. A prefrontal trough approaches Wednesday night and moves through Thursday night into Friday. A cold front moves through the area Friday night. High pressure builds behind the front Saturday. Another frontal system approaches for Saturday night into Sunday night. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Ridging continues to build aloft today as surface high pressure sets up off the middle atlantic coast. Some mid level moisture rolling over the ridge axis to the west will bring some scattered clouds this afternoon, but sky conditions should average mostly sunny through the day. Winds around the high will increase out of the south preventing temperatures near the coast from rising above the lower 80s. For the New York City metro and the interior, temperatures warm to normal levels for this time of year in the middle 80s. There is a moderate risk of rip current development at the Atlantic facing beaches today. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... Dew points will be on the rise tonight with continued southerly flow. However, there should be enough of a pressure gradient to keep winds from going completely calm. NAM12, NAM4KM, and SREF BUFKIT profiles support this, so have not included any mention of patchy fog. Upper ridge axis moves over the region Wednesday morning and then continues east of the area through the day. Capping is noted on model soundings around 500 hPa as the region is still in close proximity to the ridge axis. This should prevent any convection from developing, although shortwave energy over the Ohio Valley begins to approach late in the day. Have continued the thinking from the previous forecast package for a slight chance of a shower or storm drifting into the NW interior late in the afternoon. Warmer air continues to be transported around the offshore high on Wednesday. 850 hPa temperatures warm 2C to 4C from those on Tuesday. Forecast highs are in the middle and upper 80s for the city and for inland location, and the lower 80s near the coast. It will also feel more humid as dew points rise into the middle and upper 60s. Heat indices could briefly touch 90 degrees in the afternoon for the NYC metro and across the interior. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... High pressure and an upper ridge axis will be moving east of the area late Wednesday afternoon into Wednesday evening. The area will then be under the influence of an upper trough into Monday as weak shortwave and associated vorts rotate through the trough. Meanwhile at the surface, as high pressure exits Wednesday evening a prefrontal trough moves into the region well ahead of a cold front. The trough moves slowly through Thursday night into Friday with the cold front passing through Friday night. As a result will have slight chance to low end chance pops Wednesday evening into Friday with the cold front likely coming through dry Friday night as the area stabilizes behind the trough. There remains some uncertainty with the timing of the shortwaves and when the best chances of precipitation will be at this time. Friday looks to be warmest day of the extended period as some clearing occurs ahead of the cold front and 850 MB temperatures near 20C. There will be a brief dry period Friday night into Saturday as upper trough weakens and surface high pressure builds. However, and stronger shortwave and vort moves through southern Canada Saturday night into Sunday with a weak surface trough developing. Will again have slight to low chance pops for Saturday night into Sunday night as there remains uncertainty with the timing and placement of the shortwaves. Monday will likely be dry with yet another shortwave possible for Monday night into Tuesday. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area through Tuesday. This will result in mainly VFR conditions with southerly winds. Gradient tightens Tuesday afternoon with some of the coastal terminals increasing to around 15 kt. Patchy MVFR BR at rural airports towards sunrise. .OUTLOOK FOR 06Z Wednesday through Saturday... .Tue Night-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressures settles offshore today and will remain in control through Wednesday. Afternoon sea breezes may bring winds close to 20 KT on the western ocean waters each day. Otherwise, winds and seas will remain below advisory levels. A weak surface pressure gradient force will be across the forecast waters Wednesday night through Saturday as prefrontal trough moves through Thursday night into Friday with a cold frontal passage Friday night. Winds and seas will remain below advisory levels Wednesday night through Saturday. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...DS/MET NEAR TERM...DS SHORT TERM...DS LONG TERM...MET AVIATION...FEB/DW MARINE...DS/MET HYDROLOGY...DS/MET
Area Forecast Discussion National Weather Service Taunton MA 346 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure over New England will move offshore today resulting in a trend toward warmer and more humid weather for the remainder of the workweek. First look at the weekend appears not as hot and humid. As for precipitation...a cold front will introduce the risk of scattered showers and thunderstorms Thu (inland) and Fri (RI and eastern MA). More unsettled weather is possible over the weekend with a period of rain possible Saturday or Sunday. && .NEAR TERM /THROUGH TODAY/... Updated at 345 am. Clear skies across region early this morning with light winds. Usual interior cool spots have dropped into 50s, and with low temperature/dewpoint spreads patchy fog has formed in the usual low lying areas. Expect any fog to quickly lift around sunrise. High pressure becomes centered off the coast today while upper ridge builds over New England. This will bring warmer SW flow to the region, although models show gradient may weaken enough to allow for sea breezes along E MA coast. Not sure that will be the case, however, since forecast soundings show potential mixing up to 830 mb this afternoon. Looks to be a situation where weak sea breeze may develop offshore but never make it onto land. In any case, plenty of sunshine is expected despite high clouds from convection in upper Midwest making trip around the top of upper ridge. Leaned toward a MOS blend which gives highs well into 80s, except upper 70s along immediate South Coast. && .SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/... Updated at 345 am. Light SW flow persists tonight as upper ridge axis extends over New England. Should also see patchy mid/high clouds from remnants of upstream convection and warm advection aloft, so lows tonight will be a few degrees higher than recent nights, mainly in 60s. Question for Wednesday is whether or not we see any convection in western New England. SW flow continues across region which will serve to stabilize increasingly warm/humid airmass in place along and SE of I-95. Farther west toward Berkshires, models show SB CAPES between 1000 and 2000 J/kg but 0-6km shear is weak (less than 20 kt) as are mid level lapse rates (less than 5C/km). In addition, 700 mb temperatures are rather warm and should act to suppress any convection. Nonetheless, it is possible we see a few showers or perhaps an isolated thunderstorm Wednesday afternoon, so included that mention across western New England. A hotter day is in store despite continued presence of mid and high clouds. Once again leaned toward MOS blend which gives highs well into 80s (but around 90 across lower CT and Merrimack Valleys and closer to 80 near the South Coast). Dewpoints should climb into 60s which will make it feel more humid, but heat indices should stay close to actual temperatures, which would be below Advisory criteria. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Updated at 345 am. Highlights ... * Risk of scattered T-storms Thu (inland) & Fri (RI & eastern MA) * Additional showers possible over the weekend * Very warm and humid Thu and Fri Synoptic Overview ... Good model agreement among ensembles and deterministic guidance regarding the large scale flow this period with east coast ridge moving offshore Wed night and replaced by long wave trough setting up over the Great Lakes Thu and Fri. Some of the guidance suggest the trough deamplifies over the weekend however broad weak mid level cyclonic flow likely lingers across New England Sat and Sun. Thus potential periods of unsettled weather in the form of scattered showers and T-storms into this weekend. Guidance/Model assessment ... As expected at this time range deterministic guidance shows large timing differences. For example...over the weekend the GFS brings another slug of moisture into the region Sat whereas the 00z EC is about 24 hrs later with system arriving Sunday. Thus given the time range here we leaned toward the GEFS and EPS ensembles to better capture the full range of possibilities in the medium and long range. Temperatures ... New 00z guidance suggesting lots of deep layer moisture around Thu and may preclude temps from being as warm as Wed. EPS probs for 90+temps Thu is considerable lower than Wed. Thus have trended temps down Thu, nonetheless still very warm with highs in the MU80s. Highs likely jump back into the 90s Fri as both ensembles and deterministic guid have 850 temps up to +18c/+19c across southern New England. Quite humid Thu and Fri with dew pts climbing to around 70 both days. Therefore a very warm and humid Thu night is expected with lows only in the upper 60s and low 70s. For the weekend northern stream trough erodes the east coast ridge a bit resulting in temps and humidity not as oppressive as Friday. Nonetheless still warm Sat/Sun and Mon with highs well into the 80s away from the ocean. Precipitation ... Looks likes greatest risk for T-storms is Thu (interior) and Fri (RI and Eastern MA). GEFS and EPS both indicate highest probs of 1000- 2000j/kg of cape are Thu (interior) and Fri (RI & eastern MA). Given moderate instability and modest jet dynamics/wind fields could be a risk for a few strong storms Thu and Fri. Also heavy rainers possible as EPS shows high probs of PWATS of 1.5 to 2.0 inches Thu into Fri. Another chance of rain over the weekend but deterministic guidance showing a large spread in timing differences. Ensembles not much help here as it appears to be a frontal wave sliding south of New England and likely too small for ensembles to resolve. Thus low confidence forecast for the weekend. Given there is a risk for showers/T-storms just about any day this period there will also be many hours of dry weather too. Thus not a complete washout. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Updated at 345 am. Today through Wednesday...High confidence. Patchy fog in low lying areas will bring local MVFR/IFR vsbys through sunrise. Otherwise VFR today with S/SW flow. Gradient appears just strong enough to prevent sea breezes along E MA coast, but winds could back to SE for a time mainly 18z-22z. May see another round of patchy valley fog and local MVFR/IFR vsbys tonight. Widely scattered showers/tstms possible Wed afternoon, mainly near Berkshires where brief MVFR conditions are possible. KBOS TAF...High confidence. SW flow should be just strong enough to prevent sea breeze from coming onshore, but winds could back to 170-180 (true) for a couple of hours between 18z and 21z. KBDL TAF...High confidence. Outlook /Wednesday night through Saturday/... Wednesday night through Friday ... Moderate Confidence. VFR. Areas of late night/early morning IFR in fog. Scattered MVFR/IFR in afternoon and evening showers/thunderstorms, mainly Thursday and Friday. Winds becoming southwest much of the period. Saturday ... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Updated at 345 am. Short Term /through Wednesday/...High confidence. High pressure becomes centered SE of New England and brings S/SW flow. Gradient may weaken enough to allow for onshore winds near E MA coast this afternoon, but it`s more likely winds stay S or SW. Seas may approach 5 FT on outer waters E of Cape Cod late in day Wednesday due to persistent S/SW flow. Patchy fog possible tonight into Wednesday morning on S coastal waters, but is not expected to be dense or widespread. Outlook /Wednesday night through Saturday/ ... Moderate confidence. Persistent S-SW winds of 15 to 20 kt across the waters will result in modest seas. Vsby less than 1 nm at times in night time/morning fog and scattered T-storms. && .CLIMATE... Although we are not expecting record heat, here is a listing of record highs for later this week. July 13: BOS 97 in 1894 PVD 94 in 1994 BDL 99 in 1966 ORH 93 in 1894 July 14: BOS 100 in 1995 PVD 98 in 1995 BDL 100 in 1965 ORH 95 in 1952 July 15: BOS 98 in 1995 PVD 99 in 1995 BDL 100 in 1995 ORH 90 in 1892 Average Highs: BOS 82 PVD 83 BDL 85 ORH 79 && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Nocera/JWD NEAR TERM...JWD SHORT TERM...JWD LONG TERM...Nocera AVIATION...Nocera/JWD MARINE...Nocera/JWD CLIMATE...Staff
Area Forecast Discussion National Weather Service Taunton MA 346 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure over New England will move offshore today resulting in a trend toward warmer and more humid weather for the remainder of the workweek. First look at the weekend appears not as hot and humid. As for precipitation...a cold front will introduce the risk of scattered showers and thunderstorms Thu (inland) and Fri (RI and eastern MA). More unsettled weather is possible over the weekend with a period of rain possible Saturday or Sunday. && .NEAR TERM /THROUGH TODAY/... Updated at 345 am. Clear skies across region early this morning with light winds. Usual interior cool spots have dropped into 50s, and with low temperature/dewpoint spreads patchy fog has formed in the usual low lying areas. Expect any fog to quickly lift around sunrise. High pressure becomes centered off the coast today while upper ridge builds over New England. This will bring warmer SW flow to the region, although models show gradient may weaken enough to allow for sea breezes along E MA coast. Not sure that will be the case, however, since forecast soundings show potential mixing up to 830 mb this afternoon. Looks to be a situation where weak sea breeze may develop offshore but never make it onto land. In any case, plenty of sunshine is expected despite high clouds from convection in upper Midwest making trip around the top of upper ridge. Leaned toward a MOS blend which gives highs well into 80s, except upper 70s along immediate South Coast. && .SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/... Updated at 345 am. Light SW flow persists tonight as upper ridge axis extends over New England. Should also see patchy mid/high clouds from remnants of upstream convection and warm advection aloft, so lows tonight will be a few degrees higher than recent nights, mainly in 60s. Question for Wednesday is whether or not we see any convection in western New England. SW flow continues across region which will serve to stabilize increasingly warm/humid airmass in place along and SE of I-95. Farther west toward Berkshires, models show SB CAPES between 1000 and 2000 J/kg but 0-6km shear is weak (less than 20 kt) as are mid level lapse rates (less than 5C/km). In addition, 700 mb temperatures are rather warm and should act to suppress any convection. Nonetheless, it is possible we see a few showers or perhaps an isolated thunderstorm Wednesday afternoon, so included that mention across western New England. A hotter day is in store despite continued presence of mid and high clouds. Once again leaned toward MOS blend which gives highs well into 80s (but around 90 across lower CT and Merrimack Valleys and closer to 80 near the South Coast). Dewpoints should climb into 60s which will make it feel more humid, but heat indices should stay close to actual temperatures, which would be below Advisory criteria. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Updated at 345 am. Highlights ... * Risk of scattered T-storms Thu (inland) & Fri (RI & eastern MA) * Additional showers possible over the weekend * Very warm and humid Thu and Fri Synoptic Overview ... Good model agreement among ensembles and deterministic guidance regarding the large scale flow this period with east coast ridge moving offshore Wed night and replaced by long wave trough setting up over the Great Lakes Thu and Fri. Some of the guidance suggest the trough deamplifies over the weekend however broad weak mid level cyclonic flow likely lingers across New England Sat and Sun. Thus potential periods of unsettled weather in the form of scattered showers and T-storms into this weekend. Guidance/Model assessment ... As expected at this time range deterministic guidance shows large timing differences. For example...over the weekend the GFS brings another slug of moisture into the region Sat whereas the 00z EC is about 24 hrs later with system arriving Sunday. Thus given the time range here we leaned toward the GEFS and EPS ensembles to better capture the full range of possibilities in the medium and long range. Temperatures ... New 00z guidance suggesting lots of deep layer moisture around Thu and may preclude temps from being as warm as Wed. EPS probs for 90+temps Thu is considerable lower than Wed. Thus have trended temps down Thu, nonetheless still very warm with highs in the MU80s. Highs likely jump back into the 90s Fri as both ensembles and deterministic guid have 850 temps up to +18c/+19c across southern New England. Quite humid Thu and Fri with dew pts climbing to around 70 both days. Therefore a very warm and humid Thu night is expected with lows only in the upper 60s and low 70s. For the weekend northern stream trough erodes the east coast ridge a bit resulting in temps and humidity not as oppressive as Friday. Nonetheless still warm Sat/Sun and Mon with highs well into the 80s away from the ocean. Precipitation ... Looks likes greatest risk for T-storms is Thu (interior) and Fri (RI and Eastern MA). GEFS and EPS both indicate highest probs of 1000- 2000j/kg of cape are Thu (interior) and Fri (RI & eastern MA). Given moderate instability and modest jet dynamics/wind fields could be a risk for a few strong storms Thu and Fri. Also heavy rainers possible as EPS shows high probs of PWATS of 1.5 to 2.0 inches Thu into Fri. Another chance of rain over the weekend but deterministic guidance showing a large spread in timing differences. Ensembles not much help here as it appears to be a frontal wave sliding south of New England and likely too small for ensembles to resolve. Thus low confidence forecast for the weekend. Given there is a risk for showers/T-storms just about any day this period there will also be many hours of dry weather too. Thus not a complete washout. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Updated at 345 am. Today through Wednesday...High confidence. Patchy fog in low lying areas will bring local MVFR/IFR vsbys through sunrise. Otherwise VFR today with S/SW flow. Gradient appears just strong enough to prevent sea breezes along E MA coast, but winds could back to SE for a time mainly 18z-22z. May see another round of patchy valley fog and local MVFR/IFR vsbys tonight. Widely scattered showers/tstms possible Wed afternoon, mainly near Berkshires where brief MVFR conditions are possible. KBOS TAF...High confidence. SW flow should be just strong enough to prevent sea breeze from coming onshore, but winds could back to 170-180 (true) for a couple of hours between 18z and 21z. KBDL TAF...High confidence. Outlook /Wednesday night through Saturday/... Wednesday night through Friday ... Moderate Confidence. VFR. Areas of late night/early morning IFR in fog. Scattered MVFR/IFR in afternoon and evening showers/thunderstorms, mainly Thursday and Friday. Winds becoming southwest much of the period. Saturday ... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Updated at 345 am. Short Term /through Wednesday/...High confidence. High pressure becomes centered SE of New England and brings S/SW flow. Gradient may weaken enough to allow for onshore winds near E MA coast this afternoon, but it`s more likely winds stay S or SW. Seas may approach 5 FT on outer waters E of Cape Cod late in day Wednesday due to persistent S/SW flow. Patchy fog possible tonight into Wednesday morning on S coastal waters, but is not expected to be dense or widespread. Outlook /Wednesday night through Saturday/ ... Moderate confidence. Persistent S-SW winds of 15 to 20 kt across the waters will result in modest seas. Vsby less than 1 nm at times in night time/morning fog and scattered T-storms. && .CLIMATE... Although we are not expecting record heat, here is a listing of record highs for later this week. July 13: BOS 97 in 1894 PVD 94 in 1994 BDL 99 in 1966 ORH 93 in 1894 July 14: BOS 100 in 1995 PVD 98 in 1995 BDL 100 in 1965 ORH 95 in 1952 July 15: BOS 98 in 1995 PVD 99 in 1995 BDL 100 in 1995 ORH 90 in 1892 Average Highs: BOS 82 PVD 83 BDL 85 ORH 79 && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Nocera/JWD NEAR TERM...JWD SHORT TERM...JWD LONG TERM...Nocera AVIATION...Nocera/JWD MARINE...Nocera/JWD CLIMATE...Staff
Area Forecast Discussion National Weather Service Albany NY 130 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... Ridging will continue to build in aloft with the surface over the region. Mostly clear to partly cloudy skies overnight as some high level cirrus clouds stream across the region. Conditions are favorable for radiation fog development overnight especially in the river valleys locations. With overnight lows bottoming out mainly in the 50s it will be comfortable sleeping weather for most. There will be some upper 40s across the higher terrain of the southern Adirondacks, eastern Catskills and southern Green Mountains. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... High pressure in place across the region with mainly clear skies and calm winds. Some high level cirrus clouds continue to drift across the area from time to time. Fairly dry air mass in place for mid July, although radiation fog with occasional IFR conditions has already occurred at KGFL, with fog development expected at KPSF by 07Z or 08Z. Will mention any IFR in tempo groups due to some uncertainty regarding persistence of thick fog. IFR not anticipated at KALB/KPOU, but there could be some fog in the vicinity of KALB near the Mohawk River. Will mention brief MVFR vsby possible at KPOU, but thicker fog development should not occur. Any fog should dissipate by 11Z, with VFR conditions prevailing thereafter. Scattered diurnal cumulus clouds should develop with scattered-broken high level cirrus clouds around today too. Winds will be calm, then become southerly around 4-7 kt by early afternoon. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...IAA/KL/11 SHORT TERM...KL LONG TERM...11 AVIATION...JPV FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service Taunton MA 116 AM EDT TUE JUL 12 2016 .SYNOPSIS... High pressure over New England will become centered southeast of New England during Tuesday. Heat and humidity will increase this week with the high remaining centered offshore, bringing a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 115 am Update... Clear skies across region early this morning with light winds. Usual interior cool spots have dropped into 50s, and with low temperature/dewpoint spreads expect to see some patchy fog develop through sunrise. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/... Tuesday... The surface high becomes centered offshore during the day, while upper level ridge builds towards our area from the west. Southern New England gets into return low level SW flow which will begin to bring warmer and eventually more humid air into region. Mostly sunny skies expected, mainly from diurnal cumulus but could see a few higher deck clouds as well. Temperatures rise well into the 80s across much of the area. Exception will be along south coastal MA/RI, where highs in the 70s to near 80 are expected. Expecting an eventual sea breeze development along east coastal MA, but may take into midday/early afternoon to get going and overcome SW flow. Tuesday night... Surface high pressure centered offshore and light SW return flow continues. Upper ridge axis extends over New England. This will be a slightly warmer and more humid night, with lows in the 60s. Could see some patchy valley fog once more, otherwise mostly clear skies expected. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Big Picture... Longwave pattern shows steady heights through the week followed by building heights off the Atlantic Sunday and Monday. Shortwave scale shows an upper ridge with axis over New England Wednesday, shifting southeast Thursday and Friday. Shortwave over the Upper Midwest Wednesday moves into Eastern Canada and sweeps a weak shortwave across New England Friday night. Subtropical high over the Atlantic builds Sunday and Monday while another shortwave approaches from the west on Monday. General model agreement Wednesday to Friday, but uncertainty for Saturday and Sunday. Both show the Friday night cold front stalling to our south. Both the 12Z GFS and ECMWF show dry weather Saturday followed by a wave moving up the front spreading showers into our area Sunday. Earlier runs showed that wave moving past with wet weather Saturday followed by dry weather Sunday. All show high pressure and dry weather Monday. Low confidence as to which will be right for the weekend. We have chosen to compromise between the two camps for now and allow the next couple of runs provide clearer information. Details... Wednesday through Friday... High pressure offshore with a developing southwest flow over the region. This will bring in increasing dew points through the period. Temperatures aloft also increase with 850-equivalent temps 16-17C Wednesday increasing to 18-20C Thursday and Friday. Airmass also becomes increasingly unstable each day with LIs near zero in the CT Valley Wednesday but with limited cloud moisture, then sub-zero LIs across much of the area Thursday and at least part of Friday. Based on this, expect hot temps during this period with max temps either side of 90 Wednesday, and 90-95 Thursday and Friday. Dew points climb to around 70 by Friday morning so humidity levels will be at least noticeable and eventually oppressive. There is a small chance of a thunderstorm in far western MA Wednesday. Thunderstorms more likely Thursday afternoon through Friday. One concern...the GFS and EC both rush precipitation through on Friday morning, while maintaining southwest winds most areas until Friday evening. Perhaps this is focusing showers on a pre-frontal trough and keeping the main front dry. Temps aloft stay warm through the afternoon supporting the idea of a later cold fropa. We massaged the available grid data to keep chance pops into mid afternoon. Specific timing of convection is probably questionable this far out, with the important idea being that there will be precipitation during some part of Friday. Saturday-Sunday-Monday... Much uncertainty in the forecast and forecast data at this time. As noted above, the 12z GFS and EC show a low pressure wave passing us on Sunday with showers while much of the forecast grid data shows showers on Saturday and dry on Sunday. Previous model suites also went with wet weather on Saturday. We have hand-edited our database to show chance pops both days. Expect later model runs will resolve this timing to one day or the other. High pressure brings drier seasonable weather on Monday. && .AVIATION /05Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Today through Wednesday...High confidence. Patchy fog in low lying areas will bring local MVFR or perhaps IFR vsbys through sunrise. Otherwise VFR today with S/SW flow. Gradient appears just strong enough to prevent sea breezes along E MA coast, but winds could back to SE for a time mainly 18z-22z. May see another round of patchy valley fog and local MVFR/IFR vsbys tonight. Widely scattered showers/tstms possible Wed afternoon, mainly near Berkshires where brief MVFR conditions are possible. KBOS TAF...High confidence. SW flow should be just strong enough to prevent sea breeze from coming onshore, but winds could back to 170-180 (true) for a couple of hours between 18z and 21z. KBDL TAF...High confidence. Outlook /Wednesday Night through Saturday/... Wednesday through Friday... Moderate Confidence. VFR. Areas if late night/early morning IFR in fog. Scattered MVFR/IFR in afternoon and evening showers/thunderstorms, mainly Thursday and Friday. Winds becoming southwest much of the period. Saturday... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Wednesday/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England through tonight, and becomes centered offshore during Tuesday. Light and variable wind becomes prevailing SW later tonight and Tuesday, except for local sea breezes redeveloping on Tuesday. Outlook /Wednesday Night through Saturday/... Moderate confidence. Winds below 25 knots through the period. Seas mainly below 5 feet, although there is potential for brief 5 foot seas on the outer waters Thursday night and Friday. Winds becoming southwest for most of the period. Areas of poor visibility in overnight and morning fog. Scattered showers/thunderstorms mainly Thursday and Friday. Low confidence on showers for Saturday. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...WTB/NMB NEAR TERM...JWD SHORT TERM...NMB LONG TERM...WTB AVIATION...JWD MARINE...WTB/NMB
Area Forecast Discussion National Weather Service New York NY 1044 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Some slight adjustments were made regarding the temperatures, dewpoints, and cloud coverage to better match observed trends. The forecast overall remains on track. High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Cirrus clouds decrease overnight with the high pressure center moving closer and with some ridging aloft. With increasing low level moisture and light onshore flow along with cooling temperatures, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior and rural portions of the CWA will drop into the mid to upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. There is a moderate risk of rip current development at the Atlantic facing beaches on Tuesday. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area through Tuesday. This will result in mainly VFR conditions with southerly winds. Gradient tightens Tuesday afternoon with some of the coastal terminals increasing to around 15 kt. Patchy MVFR BR at rural airports towards sunrise. .OUTLOOK FOR 00Z Wednesday through Saturday... .Tue Night-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...JM/MPS SHORT TERM...MPS LONG TERM...JC AVIATION...DW MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service New York NY 1044 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Some slight adjustments were made regarding the temperatures, dewpoints, and cloud coverage to better match observed trends. The forecast overall remains on track. High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Cirrus clouds decrease overnight with the high pressure center moving closer and with some ridging aloft. With increasing low level moisture and light onshore flow along with cooling temperatures, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior and rural portions of the CWA will drop into the mid to upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. There is a moderate risk of rip current development at the Atlantic facing beaches on Tuesday. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area through Tuesday. This will result in mainly VFR conditions with southerly winds. Gradient tightens Tuesday afternoon with some of the coastal terminals increasing to around 15 kt. Patchy MVFR BR at rural airports towards sunrise. .OUTLOOK FOR 00Z Wednesday through Saturday... .Tue Night-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...JM/MPS SHORT TERM...MPS LONG TERM...JC AVIATION...DW MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service Taunton MA 946 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure over New England will become centered southeast of New England during Tuesday. Heat and humidity will increase this week with the high remaining centered offshore, bringing a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 945 pm Update... Quiet night. High clouds moving out of region per IR satellite, which will leave mostly clear skies and light winds. This will allow temperatures to drop off quickly overnight, especially in interior valleys where patchy fog should also form. May also see some fog near RI/MA South Coast. Lows in 50s to lower 60s look good. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Tuesday... The surface high becomes centered offshore during the day, while upper level ridge builds towards our area from the west. Southern New England gets into return low level SW flow which will begin to bring warmer and eventually more humid air into region. Mostly sunny skies expected, mainly from diurnal cumulus but could see a few higher deck clouds as well. Temperatures rise well into the 80s across much of the area. Exception will be along south coastal MA/RI, where highs in the 70s to near 80 are expected. Expecting an eventual sea breeze development along east coastal MA, but may take into midday/early afternoon to get going and overcome SW flow. Tuesday night... Surface high pressure centered offshore and light SW return flow continues. Upper ridge axis extends over New England. This will be a slightly warmer and more humid night, with lows in the 60s. Could see some patchy valley fog once more, otherwise mostly clear skies expected. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Big Picture... Longwave pattern shows steady heights through the week followed by building heights off the Atlantic Sunday and Monday. Shortwave scale shows an upper ridge with axis over New England Wednesday, shifting southeast Thursday and Friday. Shortwave over the Upper Midwest Wednesday moves into Eastern Canada and sweeps a weak shortwave across New England Friday night. Subtropical high over the Atlantic builds Sunday and Monday while another shortwave approaches from the west on Monday. General model agreement Wednesday to Friday, but uncertainty for Saturday and Sunday. Both show the Friday night cold front stalling to our south. Both the 12Z GFS and ECMWF show dry weather Saturday followed by a wave moving up the front spreading showers into our area Sunday. Earlier runs showed that wave moving past with wet weather Saturday followed by dry weather Sunday. All show high pressure and dry weather Monday. Low confidence as to which will be right for the weekend. We have chosen to compromise between the two camps for now and allow the next couple of runs provide clearer information. Details... Wednesday through Friday... High pressure offshore with a developing southwest flow over the region. This will bring in increasing dew points through the period. Temperatures aloft also increase with 850-equivalent temps 16-17C Wednesday increasing to 18-20C Thursday and Friday. Airmass also becomes increasingly unstable each day with LIs near zero in the CT Valley Wednesday but with limited cloud moisture, then sub-zero LIs across much of the area Thursday and at least part of Friday. Based on this, expect hot temps during this period with max temps either side of 90 Wednesday, and 90-95 Thursday and Friday. Dew points climb to around 70 by Friday morning so humidity levels will be at least noticeable and eventually oppressive. There is a small chance of a thunderstorm in far western MA Wednesday. Thunderstorms more likely Thursday afternoon through Friday. One concern...the GFS and EC both rush precipitation through on Friday morning, while maintaining southwest winds most areas until Friday evening. Perhaps this is focusing showers on a pre-frontal trough and keeping the main front dry. Temps aloft stay warm through the afternoon supporting the idea of a later cold fropa. We massaged the available grid data to keep chance pops into mid afternoon. Specific timing of convection is probably questionable this far out, with the important idea being that there will be precipitation during some part of Friday. Saturday-Sunday-Monday... Much uncertainty in the forecast and forecast data at this time. As noted above, the 12z GFS and EC show a low pressure wave passing us on Sunday with showers while much of the forecast grid data shows showers on Saturday and dry on Sunday. Previous model suites also went with wet weather on Saturday. We have hand-edited our database to show chance pops both days. Expect later model runs will resolve this timing to one day or the other. High pressure brings drier seasonable weather on Monday. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Overnight...High confidence. VFR with mostly clear skies. Local MVFR/IFR possible overnight in patchy valley fog, as well as a possibility for patchy stratus/fog overnight along south coastal MA/southern RI. Tuesday and Tuesday night...High confidence. VFR, with local MVFR possible Tuesday night in patchy valley fog once again. Prevailing S/SW winds Tue which should prevent sea breeze development along E MA coast. KBOS TAF...High confidence. VFR. SW flow Tue should be just strong enough to prevent sea breeze from coming onshore. KBDL TAF...High confidence. VFR. Outlook /Wednesday through Saturday/... Wednesday through Friday... Moderate Confidence. VFR. Areas if late night/early morning IFR in fog. Scattered MVFR/IFR in afternoon and evening showers/thunderstorms, mainly Thursday and Friday. Winds becoming southwest much of the period. Saturday... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England through tonight, and becomes centered offshore during Tuesday. Light and variable wind becomes prevailing SW later tonight and Tuesday, except for local sea breezes redeveloping on Tuesday. Outlook /Wednesday through Saturday/... Moderate confidence. Winds below 25 knots through the period. Seas mainly below 5 feet, although there is potential for brief 5 foot seas on the outer waters Thursday night and Friday. Winds becoming southwest for most of the period. Areas of poor visibility in overnight and morning fog. Scattered showers/thunderstorms mainly Thursday and Friday. Low confidence on showers for Saturday. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...WTB/NMB NEAR TERM...JWD SHORT TERM...NMB LONG TERM...WTB AVIATION...WTB/NMB/JWD MARINE...WTB/NMB
Area Forecast Discussion National Weather Service Albany NY 945 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 945 PM EDT...Mainly clear to partly cloudy skies are expected overnight with some patchy fog likely developing in river valleys. It will be cool once again tonight, with low temperatures before daybreak falling into the upper 40s to upper 50s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. This will be followed by a return ton VFR conditions for the day on Tuesday. Satellite imagery reveals few cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Skies will return to sct045 sct-bkn250 during the day on Tuesday. Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift to the south to southwest at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...KL/11 SHORT TERM...KL LONG TERM...11 AVIATION...KL/11 FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service New York NY 757 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Some slight adjustments were made to the forecast regarding the temperatures, dewpoints, and cloud coverage to better match observed trends. Otherwise, the forecast overall remains on track. High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Some initial higher coverage of cirrus clouds will decrease later this evening with the high pressure center moving closer and with some ridging aloft. Skies will further clear out overnight with high pressure and its subsidence prevailing. With increasing low level moisture and light onshore flow, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior portions of the CWA will drop into the upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. There is a moderate risk of rip current development at the Atlantic facing beaches on Tuesday. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... High pressure remains just south and east of the area through Tuesday. This will result in mainly VFR conditions with southerly winds. Gradient tightens Tuesday afternoon with some of the coastal terminals increasing to around 15 kt. Patchy MVFR BR at rural airports towards sunrise. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component FCSTS can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments expected. KLGA TAF Comments: NE winds may persist through 01Z before shifting around to the S/SE. KEWR TAF Comments: No unscheduled amendments expected. KTEB TAF Comments: NE winds may persist through 01Z before shifting around to the S/SE. KHPN TAF Comments: No unscheduled amendments expected. KISP TAF Comments: No unscheduled amendments expected. .OUTLOOK FOR 00Z Wednesday through Saturday... .Tue Night-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...JM/MPS SHORT TERM...MPS LONG TERM...JC AVIATION...DW MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service Albany NY 708 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 630 PM EDT...Patchy high clouds continue to stream across portions of the region, especially from around I-90 southward. This may be at least in part in association with a jet max retreating off the New England coast, with our area within its right entrance region. This jet max is expected to translate farther off the coast this evening, and should allow its influence and associated high clouds to decrease. So, partly cloudy this evening, then becoming mostly clear overnight. Some patchy fog will likely develop in river valleys, given that mixing was not very strong/deep this afternoon, and afternoon dewpoints held in the 50s. It will be cool once again tonight, with low temperatures before daybreak falling into the 50s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. This will be followed by a return ton VFR conditions for the day on Tuesday. Satellite imagery reveals few cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Skies will return to sct045 sct-bkn250 during the day on Tuesday. Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift to the south to southwest at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...KL/11 SHORT TERM...KL LONG TERM...11 AVIATION...KL/11 FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service Albany NY 708 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 630 PM EDT...Patchy high clouds continue to stream across portions of the region, especially from around I-90 southward. This may be at least in part in association with a jet max retreating off the New England coast, with our area within its right entrance region. This jet max is expected to translate farther off the coast this evening, and should allow its influence and associated high clouds to decrease. So, partly cloudy this evening, then becoming mostly clear overnight. Some patchy fog will likely develop in river valleys, given that mixing was not very strong/deep this afternoon, and afternoon dewpoints held in the 50s. It will be cool once again tonight, with low temperatures before daybreak falling into the 50s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. This will be followed by a return ton VFR conditions for the day on Tuesday. Satellite imagery reveals few cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Skies will return to sct045 sct-bkn250 during the day on Tuesday. Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift to the south to southwest at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...KL/11 SHORT TERM...KL LONG TERM...11 AVIATION...KL/11 FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service Taunton MA 656 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build over New England tonight, and will then become centered southeast of New England during Tuesday. Heat and humidity will increase this week with the high remaining centered offshore, bringing a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... High pressure builds across the Eastern USA, including New England. A light flow region is in place, with most of the strongest winds found in sea breezes, which will shortly diminish. Satellite shows high-level cirrus across the region but settling southeast with clearing expected before midnight. Continue to expect mostly clear skies and light winds. This will encourage radiational cooling overnight which will allow temps to fall to near the dew point. Observed evening dew points are in the 50s with a few low 60s. Expect min temps in the mid 50s to low 60s. This will allow fog to form, especially in the usual fog- favored locations inland. There continues to be a low chance of some fog/low clouds along the southern coast of RI and MA as well. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Tuesday... The surface high becomes centered offshore during the day, while upper level ridge builds towards our area from the west. Southern New England gets into return low level SW flow which will begin to bring warmer and eventually more humid air into region. Mostly sunny skies expected, mainly from diurnal cumulus but could see a few higher deck clouds as well. Temperatures rise well into the 80s across much of the area. Exception will be along south coastal MA/RI, where highs in the 70s to near 80 are expected. Expecting an eventual sea breeze development along east coastal MA, but may take into midday/early afternoon to get going and overcome SW flow. Tuesday night... Surface high pressure centered offshore and light SW return flow continues. Upper ridge axis extends over New England. This will be a slightly warmer and more humid night, with lows in the 60s. Could see some patchy valley fog once more, otherwise mostly clear skies expected. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Big Picture... Longwave pattern shows steady heights through the week followed by building heights off the Atlantic Sunday and Monday. Shortwave scale shows an upper ridge with axis over New England Wednesday, shifting southeast Thursday and Friday. Shortwave over the Upper Midwest Wednesday moves into Eastern Canada and sweeps a weak shortwave across New England Friday night. Subtropical high over the Atlantic builds Sunday and Monday while another shortwave approaches from the west on Monday. General model agreement Wednesday to Friday, but uncertainty for Saturday and Sunday. Both show the Friday night cold front stalling to our south. Both the 12Z GFS and ECMWF show dry weather Saturday followed by a wave moving up the front spreading showers into our area Sunday. Earlier runs showed that wave moving past with wet weather Saturday followed by dry weather Sunday. All show high pressure and dry weather Monday. Low confidence as to which will be right for the weekend. We have chosen to compromise between the two camps for now and allow the next couple of runs provide clearer information. Details... Wednesday through Friday... High pressure offshore with a developing southwest flow over the region. This will bring in increasing dew points through the period. Temperatures aloft also increase with 850-equivilent temps 16-17C Wednesday increasing to 18-20C Thursday and Friday. Airmass also becomes increasingly unstable each day with LIs near zero in the CT Valley Wednesday but with limited cloud moisture, then sub-zero LIs across much of the area Thursday and at least part of Friday. Based on this, expect hot temps during this period with max temps either side of 90 Wednesday, and 90-95 Thursday and Friday. Dew points climb to around 70 by Friday morning so humidity levels will be at least noticeable and eventually oppressive. There is a small chance of a thunderstorm in far western MA Wednesday. Thunderstorms more likely Thursday afternoon through Friday. One concern...the GFS and EC both rush precipitation through on Friday morning, while maintaining southwest winds most areas until Friday evening. Perhaps this is focussing showers on a pre-frontal trough and keeping the main front dry. Temps aloft stay warm through the afternoon supporting the idea of a later cold fropa. We massaged the available grid data to keep chance pops into mid afternoon. Specific timing of convection is probably questionable this far out, with the important idea being that there will be precipitation during some part of Friday. Saturday-Sunday-Monday... Much uncertainty in the forecast and forecast data at this time. As noted above, the 12z GFS and EC show a low pressure wave passing us on Sunday with showers while much of the forecast grid data shows showers on Saturday and dry on Sunday. Previous model suites also went with wet weather on Saturday. We have hand-edited our database to show chance pops both days. Expect later model runs will resolve this timing to one day or the other. High pressure brings drier seasonable weather on Monday. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Tonight...High confidence. VFR with mostly clear skies. Local MVFR/IFR possible overnight in valley fog, as well as a possibility for patchy stratus/fog overnight along south coastal MA/southern RI. Tuesday and Tuesday night...High confidence. VFR, with local MVFR possible Tuesday night in valley fog. Prevailing S/SW winds Tue except sea breeze development expected along the shorelines. KBOS TAF...High confidence. VFR with light wind. Sea breeze should redevelop during Tuesday around midday. KBDL TAF...High confidence. VFR. Outlook /Wednesday through Saturday/... Wednesday through Friday... Moderate Confidence. VFR. Areas if late night/early morning IFR in fog. Scatterd MVFR/IFRin afternoon and evening showers/thunderstorms, mainly Thursday andFriday. Winds becoming southwest much of the period. Saturday... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England through tonight, and becomes centered offshore during Tuesday. Light and variable wind becomes prevailing SW later tonight and Tuesday, except for local sea breezes redeveloping on Tuesday. Outlook /Wednesday through Saturday/... Moderate confidence. Winds below 25 knots through the period. Seas mainly below 5 feet, although there is potential for brief 5 foot seas on the outer waters Thursday night and Friday. Winds becoming southwest for most of the period. Areas of poor visibility in overnight and morning fog. Scattered showers/thunderstorms mainly Thursday and Friday. Low confidence on showers for Saturday. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...WTB/NMB NEAR TERM...WTB/NMB SHORT TERM...NMB LONG TERM...WTB AVIATION...WTB/NMB MARINE...WTB/NMB
Area Forecast Discussion National Weather Service Albany NY 630 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 630 PM EDT...Patchy high clouds continue to stream across portions of the region, especially from around I-90 southward. This may be at least in part in association with a jet max retreating off the New England coast, with our area within its right entrance region. This jet max is expected to translate farther off the coast this evening, and should allow its influence and associated high clouds to decrease. So, partly cloudy this evening, then becoming mostly clear overnight. Some patchy fog will likely develop in river valleys, given that mixing was not very strong/deep this afternoon, and afternoon dewpoints held in the 50s. It will be cool once again tonight, with low temperatures before daybreak falling into the 50s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. Satellite imagery reveals few-sct cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift from the southerly direction at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...KL/11 SHORT TERM...KL LONG TERM...11 AVIATION...KL/BGM/JPV FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service New York NY 610 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Skies will clear out tonight. With increasing low level moisture and light winds, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior portions of the CWA will drop into the upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. There is a moderate risk of rip current development at the Atlantic facing beaches on Tuesday. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /22Z MONDAY THROUGH SATURDAY/... Seabreeze finally making steady progress north and should pass through KLGA, KEWR, and KTEB in the next hour, possibly two hours. Otherwise, high pressure builds over the terminals through the overnight. Fair weather cumulus with bases around 4000-5000 ft will diminish by early this evening VFR overnight with light winds. Perhaps some MVFR VIS in BR at rural airports towards sunrise. VFR continues for Tuesday with southerly flow. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component FCSTS can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments expected. KLGA TAF Comments: High confidence of seabreeze passage by 00Z. KEWR TAF Comments: High confidence of seabreeze passage by 00Z. KTEB TAF Comments: Moderate to high confidence of seabreeze passage by 00Z. KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 18Z Tuesday through Saturday... .Tue AFTN-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly afternoon TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the Morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...MPS SHORT TERM...MPS LONG TERM...JC AVIATION...Tongue/DW MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service Albany NY 421 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 410 PM EDT, patchy high clouds continue to stream across portions of the region, especially from around I-90 southward. This may be at least in part in association with a jet max retreating off the New England coast, with our area within its right entrance region. This jet max is expected to translate farther off the coast this evening, and should allow its influence and associated high clouds to decrease. So, partly cloudy this evening, then becoming mostly clear overnight. Some patchy fog will likely develop in river valleys, given that mixing was not very strong/deep this afternoon, and afternoon dewpoints held in the 50s. It will be cool once again tonight, with low temperatures before daybreak falling into the 50s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday-Tuesday night, a weakening upper level shortwave will approach from the Great Lakes, and then move southeast, grazing southern areas Tuesday afternoon/evening. Weak dynamics and some developing mid level warm advection should promote a period of mid level clouds Tuesday afternoon/evening, but it appears that the low levels should remain fairly dry. Therefore, other than clouds, will keep out mention of any showers, although can not completely rule out a sprinkle or two reaching the ground in some areas of the SE Catskills and mid Hudson Valley region late Tuesday afternoon/early Tuesday night. Otherwise, it will be warmer Tuesday, with late day high temperatures reaching the mid/upper 80s in valleys, and upper 70s to lower 80s across higher elevations. For Tuesday night/Wednesday morning, low temperatures should only fall into the mid/upper 60s in valley areas, and generally upper 50s to lower 60s for higher elevations. Wednesday-Wednesday night, a strengthening low level south/southwest flow and at least some sunshine in the morning should allow temperatures to reach the upper 80s to lower 90s in valley areas, with 80s even across higher terrain. The combination of increasing moisture will contribute to enhanced instability across western areas. Some models suggest isolated to scattered convection develops late Wed afternoon into Wed night, mainly across the western Adirondacks. Will include slight chance mention of isolated showers/thunderstorms for Wednesday afternoon for areas west of the Hudson River, with some low chance mention across the western Adirondacks/Mohawk Valley and eastern Catskills into early Wednesday night. Dewpoints should climb into the mid/upper 60s by late Wed afternoon, which should result in heat indices reaching the mid 90s within the Hudson River Valley. Warm and humid for Wed night, with some low clouds possibly developing. Low temperatures should only fall into the upper 60s to lower 70s for most valley areas, and lower/mid 60s across higher elevations. Thursday, another hot and humid day, although clouds and earlier and more widespread convective development may preclude temperatures from exceeding 90. For now, expect most valley areas to reach 85-90, with lower/mid 80s across higher elevations. However, if convection holds off until later in the day, and more sunshine occurs, high temperatures could easily reach into the lower 90s or slightly higher. Dewpoints should be higher than Wednesday, reaching into the lower 70s in valleys, and mid/upper 60s. So, even if high temperatures only reach close to 90, heat indices should still reach the upper 90s within much of the Hudson River Valley. Should the possibility of even higher heat indices increase, then heat advisories would be issued for some of these areas. Scattered, mainly pulse-type thunderstorms are expected Thursday afternoon, with locally heavy downpours likely as PWAT/s increase to over 1.5-1.75 inches. The 0-6 km bulk shear increases late Thursday across northwest areas close to 30 KT, so isolated severe can not be ruled out, especially with any cells that merge and develop associated cold pools, possibly resulting in isolated strong wind gusts. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A very active long term period is expected as hazy, hot and humid weather along with scattered showers and thunderstorms will be in the forecast for the period from Thursday night through Saturday. Thursday night and Friday...A cold front will be dropping slowly southeast from the eastern Great Lakes with a wave of low pressure moving northeast along it on Friday morning. The warm moist airmass in place ahead of this frontal boundary will clash with the cooler drier air behind it producing more showers and thunderstorms. The MLMUCAPES on Friday are generally 500 to 1000 j/kg with the theta e ridge axis not sliding east of the fa until late in the day. PWATS remain in the 1.5 to 2.0+ range so more heavy rain is possible. At this time mid level lapse rates are not overly strong generally between 5.5 and 6 C/km, however 0-6 km bulk shear increase to 50 to 60+ kts across the forecast area Friday afternoon. Lows Thursday night are expected to be in the mid 60s to lower 70s with highs on Friday in the upper 70s to lower 90s. Friday night and Saturday...The upper level low and associated vort max will be crossing the region producing more scattered showers and thunderstorms. Lows Friday night are expected to be in the upper 50s to upper 60s with highs on Saturday in the upper 60s to mid 80s. Saturday night and Sunday at this time look dry as a ridge of high pressure builds in from the eastern Great Lakes. Lows on Saturday night are expected to be in the mid 50s to mid 60s with highs on Sunday in the mid 70s to mid 80s. Overall expect temperatures to be well above normal with precipitation above normal as well. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. Satellite imagery reveals few-sct cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift from the southerly direction at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Isolated SHRA...TSRA. Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA. Thursday: Moderate Operational Impact. Scattered SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Relative humidity values are expected to recover to percent this afternoon. Values are expected to recover to 90 to near 100 percent tonight, with widespread dew formation likely. Minimum values Tuesday afternoon are forecast to be generally 35 to 45 percent range. Light/variable winds are expected overnight, with south winds of 10 mph or less Tuesday. && .HYDROLOGY... High pressure will dominate our weather into Wednesday, with mainly fair weather. Heat and humidity will return for Wednesday and Thursday ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA/KL NEAR TERM...KL SHORT TERM...KL LONG TERM...11 AVIATION...KL/BGM/JPV FIRE WEATHER...IAA/KL HYDROLOGY...IAA/KL
Area Forecast Discussion National Weather Service Taunton MA 403 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build over New England tonight, and will then become centered southeast of New England during Tuesday. Heat and humidity will increase this week with the high remaining centered offshore, bringing a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 4 PM Update... Surface high pressure continues to move across our area this evening and overnight. Lingering patchy diurnal cumulus dissipate leaving mostly clear skies with some cirrus. The light to calm winds, mainly clear skies, and dry airmass will help lows fall back into the mid and upper 50s inland and to the lower 60s near the coast. There may be some patchy valley fog inland, and there is a low chance of some patchy fog/stratus along south coastal MA and southern RI. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Tuesday... The surface high becomes centered offshore during the day, while upper level ridge builds towards our area from the west. Southern New England gets into return low level SW flow which will begin to bring warmer and eventually more humid air into region. Mostly sunny skies expected, mainly from diurnal cumulus but could see a few higher deck clouds as well. Temperatures rise well into the 80s across much of the area. Exception will be along south coastal MA/RI, where highs in the 70s to near 80 are expected. Expecting an eventual sea breeze development along east coastal MA, but may take into midday/early afternoon to get going and overcome SW flow. Tuesday night... Surface high pressure centered offshore and light SW return flow continues. Upper ridge axis extends over New England. This will be a slightly warmer and more humid night, with lows in the 60s. Could see some patchy valley fog once more, otherwise mostly clear skies expected. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Big Picture... Longwave pattern shows steady heights through the week followed by building heights off the Atlantic Sunday and Monday. Shortwave scale shows an upper ridge with axis over New England Wednesday, shifting southeast Thursday and Friday. Shortwave over the Upper Midwest Wednesday moves into Eastern Canada and sweeps a weak shortwave across New England Friday night. Subtropical high over the Atlantic builds Sunday and Monday while another shortwave approaches from the west on Monday. General model agreement Wednesday to Friday, but uncertainty for Saturday and Sunday. Both show the Friday night cold front stalling to our south. Both the 12Z GFS and ECMWF show dry weather Saturday followed by a wave moving up the front spreading showers into our area Sunday. Earlier runs showed that wave moving past with wet weather Saturday followed by dry weather Sunday. All show high pressure and dry weather Monday. Low confidence as to which will be right for the weekend. We have chosen to compromise between the two camps for now and allow the next couple of runs provide clearer information. Details... Wednesday through Friday... High pressure offshore with a developing southwest flow over the region. This will bring in increasing dew points through the period. Temperatures aloft also increase with 850-equivilent temps 16-17C Wednesday increasing to 18-20C Thursday and Friday. Airmass also becomes increasingly unstable each day with LIs near zero in the CT Valley Wednesday but with limited cloud moisture, then sub-zero LIs across much of the area Thursday and at least part of Friday. Based on this, expect hot temps during this period with max temps either side of 90 Wednesday, and 90-95 Thursday and Friday. Dew points climb to around 70 by Friday morning so humidity levels will be at least noticeable and eventually oppressive. There is a small chance of a thunderstorm in far western MA Wednesday. Thunderstorms more likely Thursday afternoon through Friday. One concern...the GFS and EC both rush precipitation through on Friday morning, while maintaining southwest winds most areas until Friday evening. Perhaps this is focussing showers on a pre-frontal trough and keeping the main front dry. Temps aloft stay warm through the afternoon supporting the idea of a later cold fropa. We massaged the available grid data to keep chance pops into mid afternoon. Specific timing of convection is probably questionable this far out, with the important idea being that there will be precipitation during some part of Friday. Saturday-Sunday-Monday... Much uncertainty in the forecast and forecast data at this time. As noted above, the 12z GFS and EC show a low pressure wave passing us on Sunday with showers while much of the forecast grid data shows showers on Saturday and dry on Sunday. Previous model suites also went with wet weather on Saturday. We have hand-edited our database to show chance pops both days. Expect later model runs will resolve this timing to one day or the other. High pressure brings drier seasonable weather on Monday. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 20Z Update... This evening...High confidence. VFR conditions expected through this evening. Overall winds light and variable across the interior. East coastal MA sea breeze lingers thru early evening. Potential for a south coastal MA/RI sea breeze developing briefly late today. Overnight...High confidence. VFR, but local MVFR/IFR possible tonight in valley fog, as well as a possibility for patchy stratus/fog overnight along south coastal MA/southern RI. Tuesday and Tuesday night...High confidence. VFR, with local MVFR possible Tuesday night in valley fog. Prevailing S/SW winds Tue except sea breeze development expected along the shorelines. KBOS TAF...High confidence. VFR. Weak seabreeze lingers into early this evening. Sea breeze should redevelop during Tuesday around midday. KBDL TAF...High confidence. VFR. Outlook /Wednesday through Saturday/... Wednesday through Friday... Moderate Confidence. VFR. Areas if late night/early morning IFR in fog. Scatterd MVFR/IFRin afternoon and evening showers/thunderstorms, mainly Thursday andFriday. Winds becoming southwest much of the period. Saturday... Low confidence. VFR. Low confidence potential for MVFR/IFR developing in showers and scattered thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England through tonight, and becomes centered offshore during Tuesday. Light and variable wind becomes prevailing SW later tonight and Tuesday, except for local sea breezes redeveloping on Tuesday. Outlook /Wednesday through Saturday/... Moderate confidence. Winds below 25 knots through the period. Seas mainly below 5 feet, although there is potential for brief 5 foot seas on the outer waters Thursday night and Friday. Winds becoming southwest for most of the period. Areas of poor visibility in overnight and morning fog. Scattered showers/thunderstorms mainly Thursday and Friday. Low confidence on showers for Saturday. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...WTB/NMB NEAR TERM...NMB SHORT TERM...NMB LONG TERM...WTB AVIATION...WTB/NMB MARINE...WTB/NMB
Area Forecast Discussion National Weather Service New York NY 357 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Skies will clear out tonight. With increasing low level moisture and light winds, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior portions of the CWA will drop into the upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... High pressure builds over the terminals through the overnight. Fair weather cumulus with bases around 4500 ft will diminish by late AFTN (22Z). Northerly winds will eventually shift around to S late this AFTN into the evening as sea breezes move inland from the Atlantic and CT coasts. VFR overnight with light winds. Perhaps some MVFR VIS in BR at rural airports towards sunrise. VFR continues for Tuesday with southern flow. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component FCSTS can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: Sea Breeze has moved south of the airport causing a wind shift to the northeast. SFC winds eventually become south...but there is low confidence in the timing of this. It could be as late as 00Z. KLGA TAF Comments: No long expect the seabreeze to reach the field this evening. KEWR TAF Comments: A lot of variability in direction the rest of the AFTN. With the Sea Breeze having dissipated...winds should stay more NE into the evening. KTEB TAF Comments: No unscheduled amendments expected KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 18Z Tuesday through Saturday... .Tue AFTN-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly AFTN TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the Morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...MPS SHORT TERM...MPS LONG TERM...JC AVIATION...Tongue MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service Taunton MA 354 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build over New England tonight, and will then become centered southeast of New England during Tuesday. Heat and humidity will increase this week with the high remaining centered offshore, bringing a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 4 PM Update... Surface high pressure continues to move across our area this evening and overnight. Lingering patchy diurnal cumulus dissipate leaving mostly clear skies with some cirrus. The light to calm winds, mainly clear skies, and dry airmass will help lows fall back into the mid and upper 50s inland and to the lower 60s near the coast. There may be some patchy valley fog inland, and there is a low chance of some patchy fog/stratus along south coastal MA and southern RI. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Tuesday... The surface high becomes centered offshore during the day, while upper level ridge builds towards our area from the west. Southern New England gets into return low level SW flow which will begin to bring warmer and eventually more humid air into region. Mostly sunny skies expected, mainly from diurnal cumulus but could see a few higher deck clouds as well. Temperatures rise well into the 80s across much of the area. Exception will be along south coastal MA/RI, where highs in the 70s to near 80 are expected. Expecting an eventual sea breeze development along east coastal MA, but may take into midday/early afternoon to get going and overcome SW flow. Tuesday night... Surface high pressure centered offshore and light SW return flow continues. Upper ridge axis extends over New England. This will be a slightly warmer and more humid night, with lows in the 60s. Could see some patchy valley fog once more, otherwise mostly clear skies expected. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Highlights... * Becoming hot and humid late in the week. * Scattered thunderstorms will likely affect the region late Thu and Fri. * Low confidence forecast for the weekend. May have more showers on Sat. OVERALL PICTURE... Upper flow across North America becomes more zonal for a time this coming week. Fairly high confidence of hot temperatures and increasing humidity for the middle and latter part of the week. Have a risk of approaching Heat Advisory criteria on Thursday if dewpoints reach at least 70. Shortwave trof rotating about Hudson Bay vortex and associated surface front approaches southern New England Thursday night. The timing of this feature will be critical as to threat of strong to severe thunderstorms. Model consensus would seem to suggest that the front may pass through southern New England Friday morning or early afternoon, not diurnally optimal for convection. Confidence is relatively low for the weekend. May not be as dry as originally thought since flow aloft remains cyclonic and from the WSW or SW. Also, both the 00Z GFS and ECMWF operational runs suggest a frontal wave on Saturday. DETAILS... Wed...Temperatures will likely reach mid 80s to lower 90s. Cannot rule out isolated thunderstorm over the western higher terrain areas but expect that most, if not all, of region remains dry. Thu...Operational models have ensemble support for a hot/humid day. H850 temperatures will likely rise to at least around 18C and will likely see all but the south coast and highest terrain areas reach 90 to 95. Sufficient instability may exist for scattered pulse late afternoon/evening thunderstorms in the western zones. As the surface front or prefrontal trough approaches, convection may persist into the night for a time across the western zones. Fri...Upper short wave trof and associated surface front crosses the region. Timing is critical with regard to convective potential. Model consensus for now would seem to have the frontal boundary making it to the coast by midday or early afternoon, too soon to tap into diurnal heating. However, Friday is still 5 days away and so cannot be all that confident on timing details. There looks to be sufficient bulk shear to support organized storms if the instability is sufficient. Expect max temperatures to be a few degrees lower than Thursday due to increased cloudiness. Nevertheless, many locations are expected to reach into the lower 90s with dewpoints in the upper 60s to near 70. Next weekend...Confidence is relatively low at this time regarding next Saturday and Sunday. Both the GFS and ECMWF operational runs depict the broad upper trof axis to be west of the area and even hint at a frontal wave passing through or just SE of the area on Saturday. Have raised POPs and sky cover some for Saturday as a consequence. Also, lowered temperatures along the coastal plain a tad as well due to potential for more clouds and possibly onshore flow. If a surface wave forms more as per the GFS, then temperatures would likely be cooler and rainfall steadier. On the other hand, the ECMWF might keep some of southern New England in the warm sector and more convectively active. It is just too soon to be able to nail down specifics this far out. Have opted for POPs below chance for Sunday as looks for now that drier air should infiltrate the region from the west. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 20Z Update... This evening...High confidence. VFR conditions expected through this evening. Overall winds light and variable across the interior. East coastal MA sea breeze lingers thru early evening. Potential for a south coastal MA/RI sea breeze developing briefly late today. Overnight...High confidence. VFR, but local MVFR/IFR possible tonight in valley fog, as well as a possibility for patchy stratus/fog overnight along south coastal MA/southern RI. Tuesday and Tuesday night...High confidence. VFR, with local MVFR possible Tuesday night in valley fog. Prevailing S/SW winds Tue except sea breeze development expected along the shorelines. KBOS TAF...High confidence. VFR. Weak seabreeze lingers into early this evening. Sea breeze should redevelop during Tuesday around midday. KBDL TAF...High confidence. VFR. Outlook /Wednesday through Saturday/...High confidence. Wednesday through Thursday morning...Generally VFR except areas of MVFR/IFR in fog along the south coast. Thursday afternoon through Friday...Generally VFR but areas of MVFR cigs/vsbys in vicinity of scattered showers and thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England through tonight, and becomes centered offshore during Tuesday. Light and variable wind becomes prevailing SW later tonight and Tuesday, except for local sea breezes redeveloping on Tuesday. Outlook /Wednesday through Saturday/...High confidence. Relatively light wind fields are expected and seas should generally remain below 5 feet across all waters. There will be areas of late night and early morning fog, especially along the south coastal waters during this time period. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...NMB/JWD/Thompson NEAR TERM...NMB SHORT TERM...NMB LONG TERM...Thompson AVIATION...NMB/JWD/Thompson MARINE...NMB/JWD/Thompson
Area Forecast Discussion National Weather Service New York NY 330 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure south of Long Island remains in control through Wednesday. A prefrontal trough then approaches on Thursday and passes through Thursday night into Friday morning. The trailing cold front then moves through Friday night. High pressure builds back in behind the front on Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... High pressure continues to build in from the west, and the center of the high will pass overhead before moving offshore by daybreak Tuesday. Skies will clear out tonight. With increasing low level moisture and light winds, can expect patchy fog to develop across interior portions of the Lower Hudson Valley, southern CT, and Long Island. Lows tonight will range from the upper 60s to around 70 in/around NYC to the low to mid 60s for most coastal locations. Interior portions of the CWA will drop into the upper 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With high pressure centered south of Long Island and east of NJ, return flow develops with increasing S-SW winds. Humidity levels will increase and surface dewpoints climb into the low 60s throughout. Temps creep up a bit as well, with highs generally in the low to mid 80s near the coasts, and in the mid to upper 80s across NYC and the interior. The heat index may approach 90 in some of the warmer areas. Tuesday night will feature clear skies and light winds once again. Persistent southerly flow will allow dewpoints to continue to creep up, and patchy fog is possible once again away from NYC. Lows will generally be in the 60s. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Deep-layered ridging will be centered offshore during Wednesday. Resulting high pressure should still be strong enough to keep the CWA dry during the day. Looks like mid level capping could prevent shower development altogether, but there is still a slight chance that a shower or thunderstorm develops just off to the west and drifts into the far NW zones during the afternoon. Went a little above guidance for high temps as models agree upon an 850mb temperature of around 16C during the afternoon. A prefrontal trough approaches on Thursday with supplemental lift during the afternoon and nighttime as a shortwave approaches and moves through. Capped pops at chance through the period, but it would appear that the highest threat of showers and storms will be in the afternoon and night. The trough is progged to be right over the CWA during Friday morning, so will leave in a chance of showers and storms during the morning, then the boundary shifts east with a drying column during the afternoon. 850mb temps are forecast to be 18-19C during the afternoon, and with boundary layer winds with a westerly component, high temperatures are expected to reach the low-mid 90s for parts of the city and urban NJ areas, and upper 80s to low 90s for just about elsewhere. Assuming the boundary shifts east as progged, drier air should mix down with daytime heating outside of any sea breezes,keeping maximum heat index values below advisory criteria. A dry cold front passage is expected Friday night with high pressure keeping Saturday dry. Highs Saturday returning to normal levels behind the front. A wave of low pressure may then develop along the front to our south and potentially bring us rainfall at some period from Saturday night to Sunday night, or even Monday morning. With uncertainty of the eventual development, track, and timing of this system, have opted for slight chc pops for most of this period. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... High pressure builds over the terminals through the overnight. Fair weather cumulus with bases around 4500 ft will diminish by late AFTN (22Z). Northerly winds will shift around to S this AFTN as sea breezes move inland from the Atlantic and CT coasts. VFR overnight with light winds. Perhaps some MVFR VIS in BR at rural airports towards sunrise. VFR continues for Tuesday with southern flow. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component FCSTS can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: High confidence in SFC winds becoming solidly south as the Sea Breeze works inland. KLGA TAF Comments: Wind shift from Sea Breeze could be as late as 00Z. KEWR TAF Comments: A lot of variability in direction the rest of the AFTN. High confidence in speeds of less than 10 KT as direction settles to SE by 22-23Z. KTEB TAF Comments: No unscheduled amendments expected KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 18Z Tuesday through Saturday... .Tue AFTN-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly AFTN TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the Morning. .Sat...VFR. && .MARINE... High pressure over the area moves offshore tonight and settles south of Long Island over the ocean waters through the mid-week period. Winds and seas will remain below SCA levels during this time as well as for the rest of the forecast period in the absence of a strong pressure gradient or significant swell. && .HYDROLOGY... No significant widespread precipitation expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC/MPS NEAR TERM...MPS SHORT TERM...MPS LONG TERM...JC AVIATION...Tongue MARINE...JC/MPS HYDROLOGY...JC/MPS
Area Forecast Discussion National Weather Service Taunton MA 216 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build over New England today, resulting in clearing skies and more seasonable temperatures. Heat and humidity will increase this week as the high becomes centered offshore and brings a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 215 PM Update... Surface high pressure continues to build over our area this afternoon, and low level moisture has been more steadily eroding. The lower clouds have been clearing from north to south between noon and 2 pm, leaving partly sunny skies across northern and central MA. Mostly cloudy skies remained across northern CT and southeast MA, due to the parting stratocumulus deck as well as a cirrus deck passing thru the area. Expect to see a continued decrease in clouds across southern New England during the remainder of this afternoon. Some locales across northern MA and the Connecticut River Valley in MA/CT will manage to warm into the upper 70s and low 80s. Elsewhere across the region thinking temps will max out in the low to mid 70s due to the later thinning of the cloud deck, and the sea breeze along east coastal MA and developing sea breeze along the south coast. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... High pressure builds over southern New England tonight. Light winds, clear skies, and a dry airmass will help lows fall back into the 50s inland (where we may see some patchy valley fog) and to the lower 60s near coast. As the high becomes centered offshore Tuesday, we get into return SW flow which will begin to bring warmer (and eventually more humid) air into region. Highs will top out well into 80s (except 70s near South Coast) if not around 90 in parts of CT and Merrimack Valleys. Some of the models (00z GFS and 21z SREF in particular) try to bring showers/storms into southern New England Tue afternoon, as moisture is drawn up from the mid Atlantic states and interacts with a weak surface trough. We are not buying into this wetter solution given axis of 500 mb ridge to our W with larger scale subsidence present over region. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Highlights... * Becoming hot and humid late in the week. * Scattered thunderstorms will likely affect the region late Thu and Fri. * Low confidence forecast for the weekend. May have more showers on Sat. OVERALL PICTURE... Upper flow across North America becomes more zonal for a time this coming week. Fairly high confidence of hot temperatures and increasing humidity for the middle and latter part of the week. Have a risk of approaching Heat Advisory criteria on Thursday if dewpoints reach at least 70. Shortwave trof rotating about Hudson Bay vortex and associated surface front approaches southern New England Thursday night. The timing of this feature will be critical as to threat of strong to severe thunderstorms. Model consensus would seem to suggest that the front may pass through southern New England Friday morning or early afternoon, not diurnally optimal for convection. Confidence is relatively low for the weekend. May not be as dry as originally thought since flow aloft remains cyclonic and from the WSW or SW. Also, both the 00Z GFS and ECMWF operational runs suggest a frontal wave on Saturday. DETAILS... Wed...Temperatures will likely reach mid 80s to lower 90s. Cannot rule out isolated thunderstorm over the western higher terrain areas but expect that most, if not all, of region remains dry. Thu...Operational models have ensemble support for a hot/humid day. H850 temperatures will likely rise to at least around 18C and will likely see all but the south coast and highest terrain areas reach 90 to 95. Sufficient instability may exist for scattered pulse late afternoon/evening thunderstorms in the western zones. As the surface front or prefrontal trough approaches, convection may persist into the night for a time across the western zones. Fri...Upper short wave trof and associated surface front crosses the region. Timing is critical with regard to convective potential. Model consensus for now would seem to have the frontal boundary making it to the coast by midday or early afternoon, too soon to tap into diurnal heating. However, Friday is still 5 days away and so cannot be all that confident on timing details. There looks to be sufficient bulk shear to support organized storms if the instability is sufficient. Expect max temperatures to be a few degrees lower than Thursday due to increased cloudiness. Nevertheless, many locations are expected to reach into the lower 90s with dewpoints in the upper 60s to near 70. Next weekend...Confidence is relatively low at this time regarding next Saturday and Sunday. Both the GFS and ECMWF operational runs depict the broad upper trof axis to be west of the area and even hint at a frontal wave passing through or just SE of the area on Saturday. Have raised POPs and sky cover some for Saturday as a consequence. Also, lowered temperatures along the coastal plain a tad as well due to potential for more clouds and possibly onshore flow. If a surface wave forms more as per the GFS, then temperatures would likely be cooler and rainfall steadier. On the other hand, the ECMWF might keep some of southern New England in the warm sector and more convectively active. It is just too soon to be able to nail down specifics this far out. Have opted for POPs below chance for Sunday as looks for now that drier air should infiltrate the region from the west. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 18Z TAF Update... This afternoon/evening...Moderate confidence. MVFR cigs lingering along southern RI and far southeast MA expected to improve to VFR by 20Z. Otherwise, high confidence VFR for the remainder of this afternoon and evening as ceilings lift and clouds decrease in coverage. N winds will be quite light this afternoon, in some cases light and variable. East coastal MA sea breeze lingers thru the remainder of today, with a south coastal MA/RI sea breeze developing thru 21Z. Overnight...High confidence. VFR, but local MVFR/IFR possible tonight in valley fog, as well as possibility for patchy stratus/fog overnight along south coastal MA/southern RI. Tuesday and Tuesday night...High confidence. VFR, with local MVFR possible Tuesday night in valley fog. Prevailing S/SW winds Tue except sea breeze development expected along the shorelines. KBOS TAF...High confidence. VFR. Weak seabreeze thru the remainder of today. Sea breeze should redevelop during Tuesday around midday. KBDL TAF...High confidence. VFR. Outlook /Wednesday through Friday/...High confidence. Wednesday through Thursday morning...Generally VFR except areas of MVFR/IFR in fog along the south coast. Thursday afternoon through Friday...Generally VFR but areas of MVFR cigs/vsbys in vicinity of scattered showers and thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England today. Light N/NE flow except for local sea breezes lingering into this evening. SW flow gets underway Tue as high becomes centered offshore. Outlook /Tuesday Night through Friday/...High confidence. Relatively light wind fields are expected and seas should generally remain below 5 feet across all waters. There will be areas of late night and early morning fog, especially along the south coastal waters during this time period. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...JWD/Thompson NEAR TERM...NMB/JWD/Thompson SHORT TERM...JWD LONG TERM...Thompson AVIATION...NMB/JWD/Thompson MARINE...NMB/JWD/Thompson
Area Forecast Discussion National Weather Service New York NY 207 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure settles over the region today and moves offshore Tuesday into Wednesday. A slow moving cold front will approach from Wednesday night into Thursday, then pass east on Friday. Another frontal system may pass through on Saturday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... High pressure continues to build in from the west. Clouds associated with a weak mid-level shortwave will also continue to erode going through the afternoon as heights aloft increase and the shortwave departs. Generally partly to mostly sunny skies for the rest of the afternoon. With weak flow, afternoon sea breezes will develop near the coast and slowly push inland. Sea breezes may struggle to make it into NE NJ and the Lower Hudson Valley. High temperatures will be in the upper 70s to the lower 80s. Coolest conditions near the immediate coast and across eastern Long Island and southeast Connecticut where more cloud cover will reside. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... Tranquil conditions and mostly clear skies are expected tonight as the surface high and building ridging aloft dominate. The high will move offshore on Tuesday, but the ridge axis will still be located to the west of the region. Warmer air begins to move around the offshore high with 850 HPA temperatures increasing 2C to 4C from Monday. However, increasing southerly flow off the Atlantic around the offshore high will likely allow temperatures to only warm to near normal levels for this time of year. Highs in the middle 80s are forecast away from the coast, with readings closer to 80 near the coast due to the onshore flow. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... High pressure at the surface will slowly pass off the Mid Atlantic coast Tue night. Models show some moisture return on the back side of the sfc high, perhaps a weak shortwave trough moving through the mean upper ridge which will also be passing to the east at that time. GFS likely too aggressive with moisture return and lift, and sided toward drier ECMWF/NAM ideas, with only isolated PoP from NYC west late day Wed into Wed night. A broad upper trough will then become established from the northern Plains to the Northeast later this week. A surface cold front will still be well to the NW on Thu, but expect scattered showers/tstms to develop inland Thu afternoon invof a pre-frontal trough as a mid level shortwave approaches, drifting toward the coast late day and at night. With very warm/moist low levels, S low level flow and NW flow aloft, would expect some potential for severe wx, but coverage could ultimately be limited by a mid level capping inversion if the 00Z GFs is correct. The cold front will slowly approach on Friday, with only slight chance PoP at most as deeper moisture will be shunted to the east. Fri could be the hottest day of the week, with lower/mid 90s except at south facing coastlines, and potential for the heat index to touch 100 in urban NE NJ. This front should move east by evening, then latest model/ensemble guidance indicates potential for another frontal system to quickly follow for Sat. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... High pressure builds over the terminals this AFTN. Fair weather cumulus with bases around 4500 ft will diminish by late AFTN (21Z). Northerly winds will shift around to S this AFTN as sea breezes develop. VFR overnight with perhaps some MVFR VIS in BR at rural airports towards sunrise and light winds. VFR continues for Tuesday with southern flow. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component fcsts can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: High confidence in southerly SFC wind for INTL departure bank. KLGA TAF Comments: Wind shift from Sea Breeze could be as late as 21Z. KEWR TAF Comments: High confidence in SE winds for this AFTN at less than 10 KT. KTEB TAF Comments: No unscheduled amendments expected KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 18Z Tuesday through Saturday... .Tue AFTN-Wed...VFR...though patchy early morning MVFR BR possible outside the NYC Metro. .Thu...Scattered to isolated mainly AFTN TS/SHRA with local MVFR conds. .Fri...VFR...CHC TS/SHRA in the Morning. .Sat...VFR. && .MARINE... High pressure settles over the waters through the middle of the week with a cold front approaching late in the week. Winds and seas will remain below SCA levels through the period. && .HYDROLOGY... No significant widespread precipitation expected through the middle of the week. Locally heavy rainfall is possible in any thunderstorms that develop on Thursday, possibly also on Saturday. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...Goodman/DS NEAR TERM...MPS SHORT TERM...DS LONG TERM...Goodman AVIATION...Tongue MARINE...Goodman/DS HYDROLOGY...Goodman/DS
Area Forecast Discussion National Weather Service Albany NY 133 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system for mid week. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1230 PM EDT, the combination of high clouds, and some lingering lower clouds has kept skies partly to mostly cloudy across the SE Catskills, mid Hudson Valley region and NW CT. Skies have become mostly sunny further N and W. We expect the overall trend for sky cover to become mostly sunny across the region by mid to late afternoon. Temperatures should continue rising, reaching highs of around 80 in many valley areas by 5 or 6 PM, with 70s for most higher terrain. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Heat and humidity return. Ridging will continue to build in. The surface high will begin to shift offshore on Tuesday with a southerly return flow developing. Aloft the ridge axis is forecast to crest over the region late Tuesday night/Wednesday morning with the axis shifting off the seaboard during the day. In the meantime, a stacked low pressure system will be on the gradual approach. Deep southwest flow will develop between the departing ridge and the approaching trough. Heat and humidity will be in the rise and will be very noticeably on Wednesday. 850 mb temperatures are forecast to rise to 16 to 18 degrees Celsius on Wednesday. Highs Tuesday are expected to be in the upper 70s to upper 80s with dew points rising into the upper 50s to mid 60s. Dew points will continue to rise Tuesday night into Wednesday with widespread mid to upper 60s anticipated. These values combined with high temperatures expected to top out in mainly on the 80s to lower 90s with result in heat indices in the upper 80s to upper 90s. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. As the atmosphere warms up and becomes increasingly more humid and unstable the threat of convection will be in the rise. With only subtle height fall expected Wednesday and upper level support remaining well to the west have slight chance pops across the local area for the afternoon hours. However, the chances for convection will continue Wednesday night as the upper trough and low pressure system`s cold front move into the Great Lakes region. Better chances will be west of the Hudson River Valley. The Storm Prediction Center has the region under a general thunderstorm outlook. Storms will be capable of locally heavy rainfall as precipitable water values are forecast to rise to 1.5+ inches. && .LONG TERM /THURSDAY THROUGH MONDAY/... The period starts out on Thursday with our region still under the influence of a very warm and moist southerly flow. It will become increasingly humid, with models indicating a pre-frontal trough moving through at some point during the afternoon or evening. This trough is expected to result in scattered showers and thunderstorms. Some of the storms could be on the stronger side depending on the eventual magnitude of instability and deep layer shear. Given the anticipated above normal PWATS of +1 to +2 STDEV, heavy rainfall is likely to occur within any persistent thunderstorms. Another rather subtle boundary may move across the region on Friday, with more mainly diurnal showers and thunderstorms. Models are showing a weaker system now compared to Thursday, but with the continued warm and humid air mass in place, scattered convection looks reasonable again. It will likely remain very warm and muggy Friday. Some of the 00Z model guidance showing a wave of low pressure developing along a fairly flat and progressive upper level trough for Saturday. Some GEFS ensemble members also depicting this potential wave with some probabilities for precip as well, so will raise pops to 30 percent to account for this possibility. This potential system should exit the region by Sunday with drier weather to close out the weekend. Overall, temperatures look to "cool" closer to normal values during the upcoming weekend, with somewhat of a reprieve in humidity levels as well. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. Satellite imagery reveals few-sct cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift from the southerly direction at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 80 to near 100 percent tonight. Minimum values Tuesday afternoon are forecast to be generally 40 to 50 percent south of Interstate 90 and 35 to 45 percent north of Interstate 90. Light northerly winds today will diminish tonight with a southerly flow developing Tuesday at generally less than 10 mph. && .HYDROLOGY... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/KL/BGM SHORT TERM...IAA LONG TERM...JPV AVIATION...BGM/JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service Albany NY 133 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system for mid week. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1230 PM EDT, the combination of high clouds, and some lingering lower clouds has kept skies partly to mostly cloudy across the SE Catskills, mid Hudson Valley region and NW CT. Skies have become mostly sunny further N and W. We expect the overall trend for sky cover to become mostly sunny across the region by mid to late afternoon. Temperatures should continue rising, reaching highs of around 80 in many valley areas by 5 or 6 PM, with 70s for most higher terrain. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Heat and humidity return. Ridging will continue to build in. The surface high will begin to shift offshore on Tuesday with a southerly return flow developing. Aloft the ridge axis is forecast to crest over the region late Tuesday night/Wednesday morning with the axis shifting off the seaboard during the day. In the meantime, a stacked low pressure system will be on the gradual approach. Deep southwest flow will develop between the departing ridge and the approaching trough. Heat and humidity will be in the rise and will be very noticeably on Wednesday. 850 mb temperatures are forecast to rise to 16 to 18 degrees Celsius on Wednesday. Highs Tuesday are expected to be in the upper 70s to upper 80s with dew points rising into the upper 50s to mid 60s. Dew points will continue to rise Tuesday night into Wednesday with widespread mid to upper 60s anticipated. These values combined with high temperatures expected to top out in mainly on the 80s to lower 90s with result in heat indices in the upper 80s to upper 90s. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. As the atmosphere warms up and becomes increasingly more humid and unstable the threat of convection will be in the rise. With only subtle height fall expected Wednesday and upper level support remaining well to the west have slight chance pops across the local area for the afternoon hours. However, the chances for convection will continue Wednesday night as the upper trough and low pressure system`s cold front move into the Great Lakes region. Better chances will be west of the Hudson River Valley. The Storm Prediction Center has the region under a general thunderstorm outlook. Storms will be capable of locally heavy rainfall as precipitable water values are forecast to rise to 1.5+ inches. && .LONG TERM /THURSDAY THROUGH MONDAY/... The period starts out on Thursday with our region still under the influence of a very warm and moist southerly flow. It will become increasingly humid, with models indicating a pre-frontal trough moving through at some point during the afternoon or evening. This trough is expected to result in scattered showers and thunderstorms. Some of the storms could be on the stronger side depending on the eventual magnitude of instability and deep layer shear. Given the anticipated above normal PWATS of +1 to +2 STDEV, heavy rainfall is likely to occur within any persistent thunderstorms. Another rather subtle boundary may move across the region on Friday, with more mainly diurnal showers and thunderstorms. Models are showing a weaker system now compared to Thursday, but with the continued warm and humid air mass in place, scattered convection looks reasonable again. It will likely remain very warm and muggy Friday. Some of the 00Z model guidance showing a wave of low pressure developing along a fairly flat and progressive upper level trough for Saturday. Some GEFS ensemble members also depicting this potential wave with some probabilities for precip as well, so will raise pops to 30 percent to account for this possibility. This potential system should exit the region by Sunday with drier weather to close out the weekend. Overall, temperatures look to "cool" closer to normal values during the upcoming weekend, with somewhat of a reprieve in humidity levels as well. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals well into the evening hours. Chance for MVFR/IFR conditions overnight into early Tuesday morning. Satellite imagery reveals few-sct cumulus clouds across the region with a canopy of thin cirrus streaming across the region. Further upstream, a thicker canopy of high and mid level clouds (still VFR) that may impact the region into this evening. Later tonight is the forecast challenge as dewpoint depressions diminish and some patchy mist/fog may develop. This would be most susceptible at climatology favored locations (KGFL and KPSF). Winds will be light N-NW around 5 kt, becoming light and variable or calm tonight. Winds shift from the southerly direction at speeds less than 10 kts on Tuesday. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 80 to near 100 percent tonight. Minimum values Tuesday afternoon are forecast to be generally 40 to 50 percent south of Interstate 90 and 35 to 45 percent north of Interstate 90. Light northerly winds today will diminish tonight with a southerly flow developing Tuesday at generally less than 10 mph. && .HYDROLOGY... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/KL/BGM SHORT TERM...IAA LONG TERM...JPV AVIATION...BGM/JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service New York NY 1244 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure settles over the region today and moves offshore Tuesday into Wednesday. A slow moving cold front will approach from Wednesday night into Thursday, then pass east on Friday. Another frontal system may pass through on Saturday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... High pressure continues to build in from the west. Clouds associated with a weak mid-level shortwave will also continue to erode going through the afternoon as heights aloft increase and the shortwave departs. Generally partly to mostly sunny skies for the rest of the afternoon. With weak flow, afternoon sea breezes will develop near the coast and slowly push inland. Sea breezes may struggle to make it into NE NJ and the Lower Hudson Valley. High temperatures will be in the upper 70s to the lower 80s. Coolest conditions near the immediate coast and across eastern Long Island and southeast Connecticut where more cloud cover will reside. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... Tranquil conditions and mostly clear skies are expected tonight as the surface high and building ridging aloft dominate. The high will move offshore on Tuesday, but the ridge axis will still be located to the west of the region. Warmer air begins to move around the offshore high with 850 HPA temperatures increasing 2C to 4C from Monday. However, increasing southerly flow off the Atlantic around the offshore high will likely allow temperatures to only warm to near normal levels for this time of year. Highs in the middle 80s are forecast away from the coast, with readings closer to 80 near the coast due to the onshore flow. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... High pressure at the surface will slowly pass off the Mid Atlantic coast Tue night. Models show some moisture return on the back side of the sfc high, perhaps a weak shortwave trough moving through the mean upper ridge which will also be passing to the east at that time. GFS likely too aggressive with moisture return and lift, and sided toward drier ECMWF/NAM ideas, with only isolated PoP from NYC west late day Wed into Wed night. A broad upper trough will then become established from the northern Plains to the Northeast later this week. A surface cold front will still be well to the NW on Thu, but expect scattered showers/tstms to develop inland Thu afternoon invof a pre-frontal trough as a mid level shortwave approaches, drifting toward the coast late day and at night. With very warm/moist low levels, S low level flow and NW flow aloft, would expect some potential for severe wx, but coverage could ultimately be limited by a mid level capping inversion if the 00Z GFs is correct. The cold front will slowly approach on Friday, with only slight chance PoP at most as deeper moisture will be shunted to the east. Fri could be the hottest day of the week, with lower/mid 90s except at south facing coastlines, and potential for the heat index to touch 100 in urban NE NJ. This front should move east by evening, then latest model/ensemble guidance indicates potential for another frontal system to quickly follow for Sat. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... High pressure builds over the terminals this AFTN. Fair weather cumulus with bases around 4000 ft will diminish by late AFTN (21Z). Northerly winds will shift around to S-SE this AFTN as sea breezes develop. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component fcsts can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: High confidence in southerly SFC wind for INTL departure bank. KLGA TAF Comments: Wind shift from Sea Breeze could be an hour or so sooner than FCST. KEWR TAF Comments: Wind shift to SE may occur +/- an hour so of FCST. The afternoon KEWR haze potential forecast is green...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 14Z Tuesday through Friday... .Tue-Wed...VFR. .Thu-Fri...Scattered to isolated AFTN showers/tstms possible with local MVFR conds. && .MARINE... High pressure settles over the waters through the middle of the week with a cold front approaching late in the week. Winds and seas will remain below SCA levels through the period. && .HYDROLOGY... No significant widespread precipitation expected through the middle of the week. Locally heavy rainfall is possible in any thunderstorms that develop on Thursday, possibly also on Saturday. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...Goodman/DS NEAR TERM...MPS SHORT TERM...DS LONG TERM...Goodman AVIATION...Tongue MARINE...Goodman/DS HYDROLOGY...Goodman/DS
Area Forecast Discussion National Weather Service Albany NY 1238 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system for mid week. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1230 PM EDT, the combination of high clouds, and some lingering lower clouds has kept skies partly to mostly cloudy across the SE Catskills, mid Hudson Valley region and NW CT. Skies have become mostly sunny further N and W. We expect the overall trend for sky cover to become mostly sunny across the region by mid to late afternoon. Temperatures should continue rising, reaching highs of around 80 in many valley areas by 5 or 6 PM, with 70s for most higher terrain. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Heat and humidity return. Ridging will continue to build in. The surface high will begin to shift offshore on Tuesday with a southerly return flow developing. Aloft the ridge axis is forecast to crest over the region late Tuesday night/Wednesday morning with the axis shifting off the seaboard during the day. In the meantime, a stacked low pressure system will be on the gradual approach. Deep southwest flow will develop between the departing ridge and the approaching trough. Heat and humidity will be in the rise and will be very noticeably on Wednesday. 850 mb temperatures are forecast to rise to 16 to 18 degrees Celsius on Wednesday. Highs Tuesday are expected to be in the upper 70s to upper 80s with dew points rising into the upper 50s to mid 60s. Dew points will continue to rise Tuesday night into Wednesday with widespread mid to upper 60s anticipated. These values combined with high temperatures expected to top out in mainly on the 80s to lower 90s with result in heat indices in the upper 80s to upper 90s. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. As the atmosphere warms up and becomes increasingly more humid and unstable the threat of convection will be in the rise. With only subtle height fall expected Wednesday and upper level support remaining well to the west have slight chance pops across the local area for the afternoon hours. However, the chances for convection will continue Wednesday night as the upper trough and low pressure system`s cold front move into the Great Lakes region. Better chances will be west of the Hudson River Valley. The Storm Prediction Center has the region under a general thunderstorm outlook. Storms will be capable of locally heavy rainfall as precipitable water values are forecast to rise to 1.5+ inches. && .LONG TERM /THURSDAY THROUGH SUNDAY/... The period starts out on Thursday with our region still under the influence of a very warm and moist southerly flow. It will become increasingly humid, with models indicating a pre-frontal trough moving through at some point during the afternoon or evening. This trough is expected to result in scattered showers and thunderstorms. Some of the storms could be on the stronger side depending on the eventual magnitude of instability and deep layer shear. Given the anticipated above normal PWATS of +1 to +2 STDEV, heavy rainfall is likely to occur within any persistent thunderstorms. Another rather subtle boundary may move across the region on Friday, with more mainly diurnal showers and thunderstorms. Models are showing a weaker system now compared to Thursday, but with the continued warm and humid air mass in place, scattered convection looks reasonable again. It will likely remain very warm and muggy Friday. Some of the 00Z model guidance showing a wave of low pressure developing along a fairly flat and progressive upper level trough for Saturday. Some GEFS ensemble members also depicting this potential wave with some probabilities for precip as well, so will raise pops to 30 percent to account for this possibility. This potential system should exit the region by Sunday with drier weather to close out the weekend. Overall, temperatures look to "cool" closer to normal values during the upcoming weekend, with somewhat of a reprieve in humidity levels as well. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR conditions expected across the terminals today into tonight. Only scattered diurnal cumulus clouds will be around this afternoon with high pressure building in. Clear skies and light winds tonight will likely lead to some radiation fog at KGFL/KPSF after 06Z Tuesday. Occasional IFR conditions look probable. Potential fog development more uncertain at KALB/KPOU, so will leave out mention for now. Winds will be light and variable, becoming N-NW around 5 kt later this morning. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 80 to near 100 percent tonight. Minimum values Tuesday afternoon are forecast to be generally 40 to 50 percent south of Interstate 90 and 35 to 45 percent north of Interstate 90. Light northerly winds today will diminish tonight with a southerly flow developing Tuesday at generally less than 10 mph. && .HYDROLOGY... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/KL/BGM SHORT TERM...IAA LONG TERM...JPV AVIATION...JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service New York NY 1236 PM EDT MON JUL 11 2016 .SYNOPSIS... High pressure settles over the region today and moves offshore Tuesday into Wednesday. A slow moving cold front will approach from Wednesday night into Thursday, then pass east on Friday. Another frontal system may pass through on Saturday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Morning forecast on track. Will update hourly grids based on latest surface obs and satellite trends, but no significant changes will be made to the forecast. Otherwise...high pressure settles over the region today while a shortwave trough off the New England coast lifts into the Canadian Maritimes. Ridging aloft builds as heights rise. Lingering low level moisture across far southeastern Connecticut and eastern Long Island will be slow to erode with partly to mostly cloudy skies forecast into the early afternoon before some clearing takes place. The rest of the area will see partly to mostly sunny skies through the day. With weak flow, afternoon sea breezes will develop near the coast and slowly push inland. Sea breezes may struggle to make it into NE NJ and the Lower Hudson Valley. High temperatures will be in the upper 70s to the lower 80s. Coolest conditions near the immediate coast and across eastern Long Island and southeast Connecticut where more cloud cover will reside. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... Tranquil conditions and mostly clear skies are expected tonight as the surface high and building ridging aloft dominate. The high will move offshore on Tuesday, but the ridge axis will still be located to the west of the region. Warmer air begins to move around the offshore high with 850 HPA temperatures increasing 2C to 4C from Monday. However, increasing southerly flow off the Atlantic around the offshore high will likely allow temperatures to only warm to near normal levels for this time of year. Highs in the middle 80s are forecast away from the coast, with readings closer to 80 near the coast due to the onshore flow. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... High pressure at the surface will slowly pass off the Mid Atlantic coast Tue night. Models show some moisture return on the back side of the sfc high, perhaps a weak shortwave trough moving through the mean upper ridge which will also be passing to the east at that time. GFS likely too aggressive with moisture return and lift, and sided toward drier ECMWF/NAM ideas, with only isolated PoP from NYC west late day Wed into Wed night. A broad upper trough will then become established from the northern Plains to the Northeast later this week. A surface cold front will still be well to the NW on Thu, but expect scattered showers/tstms to develop inland Thu afternoon invof a pre-frontal trough as a mid level shortwave approaches, drifting toward the coast late day and at night. With very warm/moist low levels, S low level flow and NW flow aloft, would expect some potential for severe wx, but coverage could ultimately be limited by a mid level capping inversion if the 00Z GFs is correct. The cold front will slowly approach on Friday, with only slight chance PoP at most as deeper moisture will be shunted to the east. Fri could be the hottest day of the week, with lower/mid 90s except at south facing coastlines, and potential for the heat index to touch 100 in urban NE NJ. This front should move east by evening, then latest model/ensemble guidance indicates potential for another frontal system to quickly follow for Sat. && .AVIATION /16Z MONDAY THROUGH FRIDAY/... High pressure builds over the terminals this AFTN. Fair weather cumulus with bases around 4000 ft will diminish by late AFTN (21Z). Northerly winds will shift around to S-SE this AFTN as sea breezes develop. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component fcsts can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: High confidence in southerly SFC wind for INTL departure bank. KLGA TAF Comments: Wind shift from Sea Breeze could be an hour or so sooner than FCST. KEWR TAF Comments: Wind shift to SE may occur +/- an hour so of FCST. The afternoon KEWR haze potential forecast is green...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected KHPN TAF Comments: No unscheduled amendments expected KISP TAF Comments: No unscheduled amendments expected .OUTLOOK FOR 14Z Tuesday through Friday... .Tue-Wed...VFR. .Thu-Fri...Scattered to isolated AFTN showers/tstms possible with local MVFR conds. && .MARINE... High pressure settles over the waters through the middle of the week with a cold front approaching late in the week. Winds and seas will remain below SCA levels through the period. && .HYDROLOGY... No significant widespread precipitation expected through the middle of the week. Locally heavy rainfall is possible in any thunderstorms that develop on Thursday, possibly also on Saturday. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...Goodman/DS NEAR TERM...MPS SHORT TERM...DS LONG TERM...Goodman AVIATION...Tongue MARINE...Goodman/DS HYDROLOGY...Goodman/DS
Area Forecast Discussion National Weather Service Albany NY 1025 AM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1020 AM...Low stratus has eroded rather quickly and being replaced by CU/SC with a canopy of higher CI/CS advecting across the entire region. While this may have slowed down the diurnal temperature climb a bit, expectations are for a partly-mostly sunny day with terrain based cumulus clouds. Per the 12Z sounding, rather stable exists up to H700 and per mixing layer heights, forecast highs look good with no changes needed at this time. Prev Disc... Heights will rise as ridging builds in at all levels of the atmosphere today. Have variable cloudy skies across the area as higher level clouds stream in from northwest and have some lingering stratus from overnight. Will have partly to mostly sunny skies today. Light northerly flow across the area with seasonable temperatures expected along with comfortable dew points mainly in the 50s. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Heat and humidity return. Ridging will continue to build in. The surface high will begin to shift offshore on Tuesday with a southerly return flow developing. Aloft the ridge axis is forecast to crest over the region late Tuesday night/Wednesday morning with the axis shifting off the seaboard during the day. In the meantime, a stacked low pressure system will be on the gradual approach. Deep southwest flow will develop between the departing ridge and the approaching trough. Heat and humidity will be in the rise and will be very noticeably on Wednesday. 850 mb temperatures are forecast to rise to 16 to 18 degrees Celsius on Wednesday. Highs Tuesday are expected to be in the upper 70s to upper 80s with dew points rising into the upper 50s to mid 60s. Dew points will continue to rise Tuesday night into Wednesday with widespread mid to upper 60s anticipated. These values combined with high temperatures expected to top out in mainly on the 80s to lower 90s with result in heat indices in the upper 80s to upper 90s. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. As the atmosphere warms up and becomes increasingly more humid and unstable the threat of convection will be in the rise. With only subtle height fall expected Wednesday and upper level support remaining well to the west have slight chance pops across the local area for the afternoon hours. However, the chances for convection will continue Wednesday night as the upper trough and low pressure system`s cold front move into the Great Lakes region. Better chances will be west of the Hudson River Valley. The Storm Prediction Center has the region under a general thunderstorm outlook. Storms will be capable of locally heavy rainfall as precipitable water values are forecast to rise to 1.5+ inches. && .LONG TERM /THURSDAY THROUGH SUNDAY/... The period starts out on Thursday with our region still under the influence of a very warm and moist southerly flow. It will become increasingly humid, with models indicating a pre-frontal trough moving through at some point during the afternoon or evening. This trough is expected to result in scattered showers and thunderstorms. Some of the storms could be on the stronger side depending on the eventual magnitude of instability and deep layer shear. Given the anticipated above normal PWATS of +1 to +2 STDEV, heavy rainfall is likely to occur within any persistent thunderstorms. Another rather subtle boundary may move across the region on Friday, with more mainly diurnal showers and thunderstorms. Models are showing a weaker system now compared to Thursday, but with the continued warm and humid air mass in place, scattered convection looks reasonable again. It will likely remain very warm and muggy Friday. Some of the 00Z model guidance showing a wave of low pressure developing along a fairly flat and progressive upper level trough for Saturday. Some GEFS ensemble members also depicting this potential wave with some probabilities for precip as well, so will raise pops to 30 percent to account for this possibility. This potential system should exit the region by Sunday with drier weather to close out the weekend. Overall, temperatures look to "cool" closer to normal values during the upcoming weekend, with somewhat of a reprieve in humidity levels as well. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... VFR conditions expected across the terminals today into tonight. Only scattered diurnal cumulus clouds will be around this afternoon with high pressure building in. Clear skies and light winds tonight will likely lead to some radiation fog at KGFL/KPSF after 06Z Tuesday. Occasional IFR conditions look probable. Potential fog development more uncertain at KALB/KPOU, so will leave out mention for now. Winds will be light and variable, becoming N-NW around 5 kt later this morning. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 80 to near 100 percent tonight. Minimum values Tuesday afternoon are forecast to be generally 40 to 50 percent south of Interstate 90 and 35 to 45 percent north of Interstate 90. Light northerly winds today will diminish tonight with a southerly flow developing Tuesday at generally less than 10 mph. && .HYDROLOGY... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/BGM SHORT TERM...IAA LONG TERM...JPV AVIATION...JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service Albany NY 1025 AM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1020 AM...Low stratus has eroded rather quickly and being replaced by CU/SC with a canopy of higher CI/CS advecting across the entire region. While this may have slowed down the diurnal temperature climb a bit, expectations are for a partly-mostly sunny day with terrain based cumulus clouds. Per the 12Z sounding, rather stable exists up to H700 and per mixing layer heights, forecast highs look good with no changes needed at this time. Prev Disc... Heights will rise as ridging builds in at all levels of the atmosphere today. Have variable cloudy skies across the area as higher level clouds stream in from northwest and have some lingering stratus from overnight. Will have partly to mostly sunny skies today. Light northerly flow across the area with seasonable temperatures expected along with comfortable dew points mainly in the 50s. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Heat and humidity return. Ridging will continue to build in. The surface high will begin to shift offshore on Tuesday with a southerly return flow developing. Aloft the ridge axis is forecast to crest over the region late Tuesday night/Wednesday morning with the axis shifting off the seaboard during the day. In the meantime, a stacked low pressure system will be on the gradual approach. Deep southwest flow will develop between the departing ridge and the approaching trough. Heat and humidity will be in the rise and will be very noticeably on Wednesday. 850 mb temperatures are forecast to rise to 16 to 18 degrees Celsius on Wednesday. Highs Tuesday are expected to be in the upper 70s to upper 80s with dew points rising into the upper 50s to mid 60s. Dew points will continue to rise Tuesday night into Wednesday with widespread mid to upper 60s anticipated. These values combined with high temperatures expected to top out in mainly on the 80s to lower 90s with result in heat indices in the upper 80s to upper 90s. The warmest temperatures and highest heat indices are expected up the Hudson River Valley. Will continue to keep mention of the heat and humidity in our Hazardous Weather Outlook. As the atmosphere warms up and becomes increasingly more humid and unstable the threat of convection will be in the rise. With only subtle height fall expected Wednesday and upper level support remaining well to the west have slight chance pops across the local area for the afternoon hours. However, the chances for convection will continue Wednesday night as the upper trough and low pressure system`s cold front move into the Great Lakes region. Better chances will be west of the Hudson River Valley. The Storm Prediction Center has the region under a general thunderstorm outlook. Storms will be capable of locally heavy rainfall as precipitable water values are forecast to rise to 1.5+ inches. && .LONG TERM /THURSDAY THROUGH SUNDAY/... The period starts out on Thursday with our region still under the influence of a very warm and moist southerly flow. It will become increasingly humid, with models indicating a pre-frontal trough moving through at some point during the afternoon or evening. This trough is expected to result in scattered showers and thunderstorms. Some of the storms could be on the stronger side depending on the eventual magnitude of instability and deep layer shear. Given the anticipated above normal PWATS of +1 to +2 STDEV, heavy rainfall is likely to occur within any persistent thunderstorms. Another rather subtle boundary may move across the region on Friday, with more mainly diurnal showers and thunderstorms. Models are showing a weaker system now compared to Thursday, but with the continued warm and humid air mass in place, scattered convection looks reasonable again. It will likely remain very warm and muggy Friday. Some of the 00Z model guidance showing a wave of low pressure developing along a fairly flat and progressive upper level trough for Saturday. Some GEFS ensemble members also depicting this potential wave with some probabilities for precip as well, so will raise pops to 30 percent to account for this possibility. This potential system should exit the region by Sunday with drier weather to close out the weekend. Overall, temperatures look to "cool" closer to normal values during the upcoming weekend, with somewhat of a reprieve in humidity levels as well. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... VFR conditions expected across the terminals today into tonight. Only scattered diurnal cumulus clouds will be around this afternoon with high pressure building in. Clear skies and light winds tonight will likely lead to some radiation fog at KGFL/KPSF after 06Z Tuesday. Occasional IFR conditions look probable. Potential fog development more uncertain at KALB/KPOU, so will leave out mention for now. Winds will be light and variable, becoming N-NW around 5 kt later this morning. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Minimum relative humidity values are expected to range from 35 to 45 percent this afternoon. Values are expected to recover to 80 to near 100 percent tonight. Minimum values Tuesday afternoon are forecast to be generally 40 to 50 percent south of Interstate 90 and 35 to 45 percent north of Interstate 90. Light northerly winds today will diminish tonight with a southerly flow developing Tuesday at generally less than 10 mph. && .HYDROLOGY... High pressure will build in and dominate our weather into Wednesday. Heat and humidity will return ahead of a slow moving low pressure system. Showers and thunderstorms are expected Thursday and Friday as the system`s cold front approaches and crosses the region. Precipitable water values are forecast to rise to 1.5 to near 2 inches, 1-2 standard deviations above normal, which means storms will be capable of locally heavy downpours. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/BGM SHORT TERM...IAA LONG TERM...JPV AVIATION...JPV FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion National Weather Service Taunton MA 1009 AM EDT MON JUL 11 2016 .SYNOPSIS... High pressure will build over New England today, resulting in clearing skies and more seasonable temperatures. Heat and humidity will increase this week as the high becomes centered offshore and brings a southwest flow of hot and humid air into the region. Scattered showers and thunderstorms may accompany the heat towards the end of the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 1000 AM Update... Sufficient trapped low level moisture remained over southern New England this morning for clouds to develop and linger. Still expect this low level moisture to scour out over the course of the day, but clearing across the area will likely take several more hours. Radar showing spotty light returns across eastern MA and RI, and as far west as the Worcester hills. Have added patchy light drizzle to the forecast thru midday as well. Forecast highs look on track, but we will need the anticipated decrease in clouds over the next few hours in order to achieve those highs. So at this time not adjusting forecast highs, but will need to monitor. 300 AM Update... Last of showers were over coastal waters SE of Nantucket and were heading farther offshore. Wide range in conditions across region with partial clearing working into lower CT Valley and outer Cape Cod while clouds remain socked in elsewhere, and it`s foggy across central MA, NE CT, and parts of E MA where rain fell last evening. Weak surface low was passing well south of New England which has maintained light N flow. There is a lot of low level moisture trapped beneath subsidence inversion, so clouds/patchy fog will hang around through daybreak, before clearing begins during morning. Some of the higher-res models (most notably HRRR, RAP, and NAM) show some light precipitation early this morning, primarily in E MA. This appears to be spotty drizzle due to deeper marine layer. Since cloud heights are not all that low in this area right now, will probably leave mention out of forecast. Question for today is how fast does clearing occur? RAP forecast soundings show reasonable trend, with much of interior breaking out 12z-14z and coastal areas a bit later, more like 14z-18z. This looks like one of those situations where low clouds erode on edges, as opposed to clearing taking place from W to E, so it`s possible some areas away from coast (E of CT River) take longer than expected to clear out. Gradient remains weak today so expect coastal sea breezes to develop later this morning and early this afternoon. Forecast highs in 70s look reasonable based upon model 2-meter temperatures. Should get to around 80 in the CT and Merrimack Valleys. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... High pressure builds over southern New England tonight. Light winds, clear skies, and a dry airmass will help lows fall back into the 50s inland (where we may see some patchy valley fog) and to the lower 60s near coast. As the high becomes centered offshore Tuesday, we get into return SW flow which will begin to bring warmer (and eventually more humid) air into region. Highs will top out well into 80s (except 70s near South Coast) if not around 90 in parts of CT and Merrimack Valleys. Some of the models (00z GFS and 21z SREF in particular) try to bring showers/storms into southern New England Tue afternoon, as moisture is drawn up from the mid Atlantic states and interacts with a weak surface trough. We are not buying into this wetter solution given axis of 500 mb ridge to our W with larger scale subsidence present over region. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Highlights... * Becoming hot and humid late in the week. * Scattered thunderstorms will likely affect the region late Thu and Fri. * Low confidence forecast for the weekend. May have more showers on Sat. OVERALL PICTURE... Upper flow across North America becomes more zonal for a time this coming week. Fairly high confidence of hot temperatures and increasing humidity for the middle and latter part of the week. Have a risk of approaching Heat Advisory criteria on Thursday if dewpoints reach at least 70. Shortwave trof rotating about Hudson Bay vortex and associated surface front approaches southern New England Thursday night. The timing of this feature will be critical as to threat of strong to severe thunderstorms. Model consensus would seem to suggest that the front may pass through southern New England Friday morning or early afternoon, not diurnally optimal for convection. Confidence is relatively low for the weekend. May not be as dry as originally thought since flow aloft remains cyclonic and from the WSW or SW. Also, both the 00Z GFS and ECMWF operational runs suggest a frontal wave on Saturday. DETAILS... Wed...Temperatures will likely reach mid 80s to lower 90s. Cannot rule out isolated thunderstorm over the western higher terrain areas but expect that most, if not all, of region remains dry. Thu...Operational models have ensemble support for a hot/humid day. H850 temperatures will likely rise to at least around 18C and will likely see all but the south coast and highest terrain areas reach 90 to 95. Sufficient instability may exist for scattered pulse late afternoon/evening thunderstorms in the western zones. As the surface front or prefrontal trough approaches, convection may persist into the night for a time across the western zones. Fri...Upper short wave trof and associated surface front crosses the region. Timing is critical with regard to convective potential. Model consensus for now would seem to have the frontal boundary making it to the coast by midday or early afternoon, too soon to tap into diurnal heating. However, Friday is still 5 days away and so cannot be all that confident on timing details. There looks to be sufficient bulk shear to support organized storms if the instability is sufficient. Expect max temperatures to be a few degrees lower than Thursday due to increased cloudiness. Nevertheless, many locations are expected to reach into the lower 90s with dewpoints in the upper 60s to near 70. Next weekend...Confidence is relatively low at this time regarding next Saturday and Sunday. Both the GFS and ECMWF operational runs depict the broad upper trof axis to be west of the area and even hint at a frontal wave passing through or just SE of the area on Saturday. Have raised POPs and sky cover some for Saturday as a consequence. Also, lowered temperatures along the coastal plain a tad as well due to potential for more clouds and possibly onshore flow. If a surface wave forms more as per the GFS, then temperatures would likely be cooler and rainfall steadier. On the other hand, the ECMWF might keep some of southern New England in the warm sector and more convectively active. It is just too soon to be able to nail down specifics this far out. Have opted for POPs below chance for Sunday as looks for now that drier air should infiltrate the region from the west. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 06Z TAF Update... Today...Moderate confidence. 14Z update... Areas of MVFR ceilings should persist until 15Z-18Z, especially across RI and eastern MA. Otherwise, becoming VFR as ceilings lift and clouds decrease in coverage. N/NE winds will be quite light and so should give way to coastal sea breezes around midday or early this afternoon. Tonight and Tuesday...High confidence. VFR, but local MVFR/IFR possible in valley fog. Light winds tonight will give way to S/SW winds Tue. KBOS TAF...Moderate confidence. MVFR ceilings persist until 15-16Z, then VFR expected. Light N/NE flow gives way to weak sea breeze around 16z. KBDL TAF...Moderate confidence. Ceilings may briefly go to MVFR during late this morning, otherwise VFR conditions forecast. Outlook /Tuesday Night through Friday/...High confidence. Tuesday night through Thursday morning...Generally VFR except areas of MVFR/IFR in fog along the south coast. Thursday afternoon through Friday...Generally VFR but areas of MVFR cigs/vsbys in vicinity of scattered showers and thunderstorms. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday/...High confidence. Winds and seas below SCA. Weak high pressure builds over New England today. Light N/NE flow gives way to local sea breezes later this morning and early this afternoon. SW flow gets underway Tue as high becomes centered offshore. Outlook /Tuesday Night through Friday/...High confidence. Relatively light wind fields are expected and seas should generally remain below 5 feet across all waters. There will be areas of late night and early morning fog, especially along the south coastal waters during this time period. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...JWD/Thompson NEAR TERM...NMB/JWD/Thompson SHORT TERM...JWD LONG TERM...Thompson AVIATION...NMB/JWD/Thompson MARINE...JWD/Thompson Area Forecast Discussion National Weather Service Grand Junction CO 418 PM MDT TUE JUL 12 2016 .SHORT TERM...(This evening through Wednesday night) Issued at 330 PM MDT Tue Jul 12 2016 Dry westerly flow will continue across eastern Utah and western Colorado through the next 36 hours. The 12Z GJT sounding only carried 0.36 of an inch precipitable water (PW) and models indicated the moisture level will change little in the near term. Consequently, look for skies to remain mostly clear tonight, Wednesday and Wednesday night. Afternoon winds will be lighter than over the past couple of days as the gradient aloft relaxes a bit. Overnight lows tonight will remain cooler than normal but expect advection of warmer air will hold off record low temperatures again tonight. Expect a commensurate warming trend in afternoon highs Wednesday followed by more moderate lows Wednesday night. .LONG TERM...(Thursday through Tuesday) Issued at 330 PM MDT Tue Jul 12 2016 Conditions will remain relatively quiet, dry and warmer than normal through early next week. Flow aloft will shift from the west on Thursday and Friday, to the southwest this weekend and into early next week. Isolated thunderstorms may arrive as early as Monday with better chances Tuesday. Latest model data suggests less moisture available on Tuesday than in earlier runs so coverage may be reduced. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 415 PM MDT Tue Jul 12 2016 VFR conditions will continue through the week. Breezy west winds end with sunset but will develop again Wednesday afternoon. The strongest winds will be along the CO/WY border with afternoon gusts around 30 MPH. && .FIRE WEATHER... Issued at 330 PM MDT Tue Jul 12 2016 An upper level disturbance moving over northwest Colorado this afternoon was responsible for enhanced west winds over fire zones 200 and 202. Combined with low RH and dry fuels strong gusty winds will continue to bring critical fire weather conditions to northwest Colorado late this afternoon into the evening. Winds will drop off as the disturbance moves east of the area and cooling prevents stronger upper level winds from transferring their momentum to the surface. Consequently, will hold onto the Red Flag Warning through 9 PM MDT, but do not anticipate a need to extend it any later tonight. Winds appear borderline for Red Flag conditions on Wednesday for fire zone 200 and 202. However, the upper level support for enhanced winds won`t be present and flow aloft relaxes a bit so less certain that critical conditions will develop. Therefore, will go with a Fire Weather Watch for those areas which will allow later shifts to evaluate need for an RFW based on data collected this afternoon/evening. && .GJT Watches/Warnings/Advisories... CO...Red Flag Warning until 9 PM MDT this evening for COZ200-202. Fire Weather Watch from Wednesday afternoon through Wednesday evening for COZ200-202. UT...None. && $$ SHORT TERM...NL LONG TERM...NL AVIATION...Joe FIRE WEATHER...NL
  [top] Area Forecast Discussion National Weather Service Denver/Boulder CO 337 PM MDT TUE JUL 12 2016 .SHORT TERM...(This evening through Wednesday) Issued at 337 PM MDT Tue Jul 12 2016 Warm temperatures and low humidities have returned this afternoon, especially in the mountain areas. Moderate westerly flow aloft has mixed down to the surface in the mountains with the warm temperatures. On the plains...showers have failed to materialize up to this point, but the HRRR shows a few showers over the Palmer Divide in the next few hours. This will be the only areas of weather this evening. For tomorrow...more of the same weather is expected as westerly flow aloft continues. Temperatures are expected to be a few degrees warmer under the persistent warm ridging over the region. Medium range models do not generate any shower activity tomorrow afternoon, but we will wait to see if the shorter range models generate showers tomorrow morning. .LONG TERM...(Wednesday night through Tuesday) Issued at 337 PM MDT Tue Jul 12 2016 The strong Westerly flow aloft will shift a bit more Northwesterly for Thursday and Friday. This will open the door for some cooler temperatures and weak surges moving into Northeast Colorado. Moisture levels will also increase across the plains leading to a better chance for showers and thunderstorms by late Thursday afternoon and again for Friday. There are some differences showing up in model solutions with the NAM being the cooler and wetter model while GFS solution is drier and warmer. At this time will go more in the middle road and see how things evolve as the week goes along. If in fact the NAM is correct may even see severe storms on the plains given higher dewpoints and CAPE values upwards of 2000j/kg on the plains and modest shear. The flow again shifts back more Southwest over the weekend as the broad high pressure builds back over the Southern High plains. Drier and warmer temperatures return under the SW flow. Model trends by early next week indicate the High pressure aloft will rebuild further North into the Central portion of the country which may begin to steer moisture back into Colorado from the Southwest. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) Issued at 337 PM MDT Tue Jul 12 2016 Minimal aviation impact expected this evening as the airmass is too warm and dry for any appreciable showers around the Denver area. Winds will oscillate back and forth between easterly and westerly through the evening as high based clouds cross overhead. Winds will return to drainage southerlies later this evening. Lighter winds are expected on Wednesday. && .FIRE WEATHER... Issued at 337 PM MDT Tue Jul 12 2016 Extremely low relative humidities are being observed in North and Middle Park along with breezy conditions. Will let the Red Flag Warning continue through expiration at 8 PM. For Wednesday...much the same conditions are expected as moderate zonal flow aloft continues with temperatures maybe a degree or two warmer. Fire behavior this afternoon has been more limited than yesterday, but may pick up again tomorrow. Will issue a Fire Weather Watch for North, Middle and South Parks, along with the northern Front Range Foothills. && .BOU Watches/Warnings/Advisories... Red Flag Warning until 8 PM MDT this evening for COZ211-213-217. Fire Weather Watch from Wednesday morning through Wednesday evening for COZ211-213>215-217. && $$ SHORT TERM...Dankers LONG TERM...Entrekin AVIATION...Dankers FIRE WEATHER...Dankers
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
330 PM CDT TUE JUL 12 2016 .SHORT TERM...(This Evening through Wednesday) Issued at 328 PM CDT TUE JUL 12 2016 Water vapor imagery showing upper wave rotating north into central Canada around an upper low over southern Saskatchewan, with another wave forming to its west. Overnight convective complex had dissipated over southeastern Kansas and southwestern Missouri with southeast winds returning early in the day. This has allowed rather moist air to return and status to be prevalent for most areas early this afternoon. Weak surface trough remains over the area from southwest to northeast. Precipitation chances remain the main challenge through Wednesday afternoon. Surface-based convection looking more and more unlikely this afternoon and evening with destabilization retarded by the stratus. A weak mid-level wave appears to have initiated a few elevated showers in central portions of the area and isolated activity seems possible into the late afternoon as this moves off. The more active period should come in the late evening to overnight hours as the low level jet increases resulting in decent convergence and isentropic lift around 850mb. With little other focusing/forcing mechanism and little model agreement, have kept pops in chance range, highest in east where the best moisture/upglide is suggested. Elevated shear and CAPE values could support some severe wind and hail. Thickness and Corfidi vectors suggest activity propagating southeast with time and have followed along in the overnight and early morning hours. Next front still looking to enter the area from the northwest in the late afternoon. Expect better insolation ahead of this front for more potential for storms with it though mid level capping aloft does look to increase somewhat. Will keep chance pops mainly in the north. Severe weather potential exists here too with wind and hail the main issues in steep mid and low level lapse rates. .LONG TERM...(Wednesday Night through Tuesday) Issued at 328 PM CDT TUE JUL 12 2016 Wednesday Night through Friday... Speed and position of the incoming front for Wednesday evening into the overnight hours has some timing differences both in synoptic models and mesoscale propagation, but for the most part sweeps the front and associated convection across the area in this time period. Locally heavy rainfall will be possible but difficult to pinpoint depending on the speed of the boundary, but should be noted as a hazard. Atmosphere looks to have a chance to heat up and destabilize before the boundary comes in, and as such these storms may bring damaging winds or hail as a hazard as well. Could likely see a break between overnight storms and redevelopment on Thursday late, before once again being reignited along and to our south as the low level jet increases. Both Wednesday night and Thursday night models also indicate shortwave trofs moving over the frontal boundary and aiding in convective development. Think the front will be shifted southward into Friday as high pressure moves into the Central Plains from the northeast, and have diminished and shifted chances to the south as a result. Highs Thursday are forecast near 90, and a few degrees cooler on Friday behind the front in the middle 80s. Friday Night through Tuesday... Shortwaves in the synoptic flow leave the weekend in another unsettled pattern. Chances for storms are seen Friday night through Sunday night, although Sunday looks like dry periods will be possible during the afternoon and evening. Monday and Tuesday look to be dry as an upper level high pressure system moves over the Central Plains. As for temperatures through the period, highs will range from the mid-80s to lower 90s, with seasonable low temperatures near the lower 70s forecast. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon) Issued at 1245 PM CDT TUE JUL 12 2016 Short term concerns are low cloud that continues to develop northeast out of south central Kansas. Believe MVFR cigs will move in shortly at FOE and TOP and expect some rises to occur with diurnal trends. With a more stable boundary layer resulting, pushed back TS mention to overnight when low level jet should form. If storms do not form, will need to watch for wind shear potential. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...65 LONG TERM...67/Heller AVIATION...65
Area Forecast Discussion National Weather Service Dodge City KS 326 PM CDT TUE JUL 12 2016 ...Upated long term section... .SHORT TERM...(This evening through Wednesday) Issued at 237 PM CDT Tue Jul 12 2016 An are of low pressure will slide westward along the KS/OK border this evening reaching far southwestern Kansas by sunrise tomorrow. Meanwhile, an associated warm front will shift from central Kansas tonight into western Kansas by sunrise tomorrow. Partly cloudy skies and dry conditions are expected with the exception of across northern Kansas where a slight chance of thunderstorms will be possible after midnight. The frontal boundary slides back east tomorrow do to an upper level disturbance moves into the area. A few thunderstorms may form along this boundary late tomorrow afternoon into tomorrow evening, mainly across central Kansas. Winds will generally be from the southeast tonight shifting to more of a northerly direction tomorrow as the frontal boundary moves through the CWA. As for temperatures, lows tonight look to range from the mid 60s across eastern Colorado to mid 70s across south central Kansas. Highs tomorrow are expected to reach into the upper 90s with some areas along the KS/OK border reaching around 100 degrees. .LONG TERM...(Wednesday night through Tuesday) Issued at 323 PM CDT Tue Jul 12 2016 Scattered thunderstorms are expected Thursday into Friday as upper level disturbances moves through the area with an upslope easterly component of the wind at the surface. A few storms Thursday afternoon may become severe with large hail and damaging winds being the main concern. Moisture will be abundant in the lower levels of the atmosphere creating an increase of cloudiness across western Kansas. Thunderstorms chances look to be confined across central Kansas Saturday morning with decreasing cloudiness as the day progresses. Models then suggest the upper level high across the Southern United States to build and shift northward into the remainder of the Plains. This will bring a drier weather pattern to western Kansas into at least the first part of next week. As for temperatures, highs look to be in the 90s Thursday then upper 80s to lower 90s Friday. A warming trend is expected this weekend into the first part of next week reaching into the upper 90s to around 100 degrees by Sunday. Lows look to dip into the 60s through Friday night then increase into the upper 60s to lower 70s this weekend into the early part of next week. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) Issued at 1212 PM CDT Tue Jul 12 2016 VFR conditions will prevail this afternoon into tonight with the exception of around the HYS terminal where a few thunderstorms could bring MVFR to IFR conditions towards sunrise tomorrow. Winds will generally be from the east to northeast at less than 10 knots. && .PRELIMINARY POINT TEMPS/POPS... DDC 71 98 69 94 / 10 10 10 40 GCK 68 97 68 92 / 10 10 10 30 EHA 69 100 67 95 / 10 10 10 30 LBL 72 101 69 97 / 10 10 10 30 HYS 69 97 69 89 / 30 20 20 30 P28 76 103 72 97 / 10 20 20 50 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Hovorka_42 LONG TERM...Hovorka_42 AVIATION...Hovorka_42
  [top] Area Forecast Discussion National Weather Service Wichita KS 325 PM CDT TUE JUL 12 2016 .SHORT TERM...(This evening through Friday night) Issued at 318 PM CDT Tue Jul 12 2016 A vigorous mid/upper trough was situated near the Canadian border over southern Manitoba and southwest Ontario. South of trough...seasonably strong WSW mid/upper flow was observed extending south across the Central Plains states. Isolated storms may develop late this afternoon/evening along a sfc trough axis over NW OK extending into south central KS where sfc heating/lower 70 dewpoints may be sufficient to erode the cap...however the threat remains conditional with H7 temperatures of 15-16C observed on the afternoon analysis. There is slightly higher confidence that widely scattered storms will develop in the 02-03z timeframe over portions of south central and southeast KS as the llj increases waa/low lvl moisture transport into the area. As the diffuse front lifts northward this evening...other storms may develop over portions of central KS. Much of this activity may remain just north and east outside of our area of responsibility but maintained pops over mainly southeast KS after midnight as some of this activity may develop SSE impacting the area through the early morning hours on Wed. The remnant frontal boundary may become a focus for deep moist convection again on Wed afternoon. Prior to storm development, afternoon highs are expected to climb into the mid and upper 90s allowing heat indices to exceed the century mark once again. Storms developing across central KS may dive SSE across much of the area again on Wed night as the low lvl moisture transport is progged to ramp up once again. Any storm developing on Wed afternoon/evening will have the potential to become severe with large hail and damaging winds as well as torrential rain with pwats running 125-150 percent of normal with warm cloud depths progged to exceed 3500 m. Thu-Fri...The potential for severe storms will return on Thursday with seasonably strong mid-lvl flow and impressive deep layer shear for mid July. Overnight/early morning convection may force the effective front further south which lowers confidence a bit and the cap is progged to weaken considerably which may allow storms to develop by midday. This could minimize some of the threat for severe storms across the area. The best chance for severe storms appears to remain across southern KS within a post-frontal easterly upslope regime through the afternoon and evening hours as a subtle pv anomaly approaches late in the period. Pwats are progged to rise above 2 inches across southern KS while warm cloud depths exceed 4000 meters supporting efficient rain production. Excessive rain and flooding may become a concern Thursday evening and Thursday night across southern KS. The front is expected to be forced south into northern OK on Fri while possibly mixing north late in the day or overnight on Friday providing a focus for additional showers and storms. Seasonably cool temperatures with highs in the upper 80s are expected on Friday. .LONG TERM...(Saturday through Tuesday) Issued at 318 PM CDT Tue Jul 12 2016 The pesky diffuse frontal boundary could linger across the area into Sat providing a focus for additional showers and storms. Shear/buoyancy profiles would suggest any storm that develops on Sat would have the potential to become severe. As we move in the latter half of the weekend and early next week a pattern change is expected. Hot and dry weather is expected to return as the subtropical ridge builds over the Central Plains states bringing above normal temperatures and dry weather conditions to the area. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) Issued at 1243 PM CDT Tue Jul 12 2016 Areas of MVFR/VFR ceilings should gradually improve by mid afternoon across central and south-central Kansas as diurnal heating increases. Isolated thunderstorms may develop early this evening from northwest Oklahoma into south-central and east-central Kansas along an inverted surface trough axis and remnant outflow boundary. A more favorable area for storm genesis may be toward mid-late evening across east-central/northeast Kansas as a 40 knot southerly low-level jet ramps up with isentropic upglide. Will include VCTS mentions at SLN...ICT...and CNU terminals for now and adjust as needed. Thermal low sets up over southwest Kansas Wednesday, with breezy southerly winds expected along/east of I-135. && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 74 97 71 92 / 20 10 30 50 Hutchinson 73 99 70 91 / 20 20 30 50 Newton 73 96 70 90 / 40 20 30 50 ElDorado 73 95 71 90 / 30 10 40 50 Winfield-KWLD 75 96 72 93 / 20 10 20 50 Russell 70 98 68 89 / 20 20 20 40 Great Bend 70 99 69 90 / 20 20 20 40 Salina 72 99 70 89 / 30 20 40 40 McPherson 72 99 70 90 / 30 20 30 50 Coffeyville 74 94 73 92 / 30 20 30 40 Chanute 73 94 72 90 / 30 20 50 40 Iola 73 93 71 90 / 40 20 50 40 Parsons-KPPF 74 94 72 91 / 30 20 30 40 && .ICT Watches/Warnings/Advisories... None. && $$ SHORT TERM...MWM LONG TERM...MWM AVIATION...JMC
  [top] Area Forecast Discussion National Weather Service Goodland KS 205 PM MDT TUE JUL 12 2016 .SHORT TERM...(This evening through Wednesday) Issued at 141 PM MDT Tue Jul 12 2016 Dry conditions will prevail this afternoon with increasing cloudiness this afternoon and evening in advance of a fast moving short wave followed by a warm front. Short term guidance has come into better agreement at midday as the HRRR and RAP have increasingly moved toward the NAM12 and SREF solutions. The ARW and NMM models however, have backed off on precip chances. Overall, I increased PoPs across the CWA in response to the model guidance coming into better agreement. The environment will become increasingly favorable for thunderstorms around or after 00Z in eastern Colorado, spreading eastward into northwest Kansas as we head through the evening and overnight. CAPE values will increase through the afternoon to near 2100 J/Kg as the warm front approaches with bulk shear at 30kt to 50kt (RAP), and DCAPE in the 400 J/Kg to 1000 J/Kg range. There is a marginal risk of severe thunderstorms that could include large hail and damaging wind gusts. .LONG TERM...(Wednesday night through Tuesday) Issued at 150 PM MDT Tue Jul 12 2016 Low chances for thunderstorms will continue Wednesday night and Thursday morning in the wake of an earlier cold frontal passage. Favorable low level upslope combined with weak shortwave trough aloft will result in limited coverage during those time periods...but increasing Thursday afternoon and evening with destabilization. Moderate to strong instability is forecast with deep layer shear of 40-50kts...an environment conducive to supercells. Only negative is lack of well-defined synoptic scale forcing which may limit overall coverage of storms. The wet pattern continues into Friday with the upper flow becoming more northwest and possible embedded shortwave trough providing lift. Afternoon instability not as impressive as Thursday...only moderate values are forecast...although deep layer shear remains around 40kts. Severe storms will be possible once again. Temperatures will be above normal on Wednesday...then below normal on Thursday and Friday. Upper ridge will begin to strengthen over the weekend. Other than some isolated storms Saturday afternoon developing on the higher terrain of eastern Colorado a hot and dry period will begin for the region. This will continue through at least Tuesday. Temperatures will return to the upper 90s/lower 100s by the beginning of next week. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) Issued at 1131 AM MDT Tue Jul 12 2016 VFR conditions will prevail at both TAF sites through the early afternoon with increasing cloudiness as we head into the late afternoon and early evening. Winds will remain under 15kt and gradually shift to the south throughout the day. Thunderstorms may develop overnight along a warm front and pass within the vicinity of both TAF sites. && .GLD Watches/Warnings/Advisories... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...TL LONG TERM...024 AVIATION...TL