Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/08/17

Area Forecast Discussion
National Weather Service Taunton MA
938 PM EST Tue Nov 7 2017 .SYNOPSIS... Low pressure passing south of the region will bring a period of light rain mainly south of the Mass Pike this evening into the overnight. High pressure will result in dry conditions and seasonably cool temperatures Wednesday into Thursday. An approaching arctic front may trigger a few rain/snow showers Thursday evening and then usher much colder air into the region for Friday and Saturday. There is a chance of precipitation for Sunday night into Monday, but confidence is low at this time. High pressure then builds into the area for mid week. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 935 PM update... While sfc low tracks well to the south, deep moisture plume ahead of sharpening mid level trough and right entrance region of upper jet moving through northern New England providing enough moisture and synoptic lift for area of rain moving across SNE this evening, especially near the coast. Along the northern edge of the precip shield across interior MA, getting reports of some snow mixing in. RAP low level temps below 850 mb indicate potential for some mix with snow southward into higher terrain of northern CT and NW RI through midnight. Temps above freezing so no accum expected, except perhaps a coating on the grass over higher elevations. As system is progressive and moving eastward, precip already ending in NW MA and will end south of the Pike after midnight from W to SE with Cape/Islands the last to dry out late tonight. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... For Wednesday, the low will continue its eastward movement away from the coast, with the pressure gradient gradually decreasing across the area as high pressure builds in. A much cooler, drier air mass will be advected southward in weakening northerly flow, with highs in the the 40s to near 50. Cool temperatures will continue into Wednesday night with freezing temperatures across all areas, with the exception of perhaps the immediate coast. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Highlights... * Much colder and coldest temperatures so far this season expected Friday into the weekend with a winter feel * Chance for precipitation late Sunday into Monday but low confidence Cool temperatures continue into Thursday though with some moderation in return flow along the coast as high pressure moves offshore. A cold front will approach by evening, and although there will be little moisture, a brief return of low-level moisture may be supportive of a brief passing shower or light drizzle overnight. Following the frontal passage, strong cold advection follows with gusty winds and the coldest air mass of the season so far settling across the area. Highs will only reach into the 30s for most areas, with 40s closer to the coast. Cold temperatures will continue into Friday night, with a hard freeze expected even at the coast as temperatures plummet into the teens to the upper 20s. Dry conditions will continue into Saturday and much of Sunday as high pressure builds across the area, though with temperatures subtly increasing each day as the air mass begins to moderate. Thereafter confidence decreases as the southern stream jet begins to shift northward. Precipitation chances late Sunday into Monday depend largely on the phasing of two embedded short wave troughs. The developing system will need to be monitored. By Monday or Monday night, the system will begin to move eastward, with high pressure and drier conditions by mid week. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Wednesday Night/... Overnight...Moderate confidence. A mix of VFR/MVFR conditions in light rain mixed with snow over higher elevations in interior MA and northern CT. Precip ending south of the Pike from W to SE 04-09z. NE gusts to 20-25 kt developing Cape/Islands after midnight. Wednesday...Moderate confidence. Areas of MVFR cigs across eastern New Eng improving to VFR, but lower cigs may lingering across Cape/Islands into the afternoon. NE gusts to 20-25 kt Cape/Islands diminishing in the afternoon. Wednesday Night...High confidence. VFR. KBOS Terminal...High confidence. Onset of light rain and development of a marginal CIG this evening should be within an hour either side of TAF. Wet Runway. KBDL Terminal...Moderate confidence. BKN025-035 may move in 1-3 hours earlier than forecast. Timing of the arrival of light rain could be earlier than forecast by an hour or so. Outlook /Thursday through Sunday/... High confidence. Thursday: VFR. Thursday Night: VFR. Breezy. Slight chance SHRA. Friday: VFR. Windy with local gusts to 30 kt. Friday Night through Veterans Day:VFR. Breezy. Saturday Night: VFR. Sunday: VFR. Slight chance SHRA. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Wednesday Night/...High confidence. N/NE winds increasing tonight into Wed morning as low pres intensifies to the south. Gusts to 25-30 kt developing over the south coastal waters with some higher gusts reaching into the NE MA waters. Winds diminishing Wed afternoon. Small craft advisories extended into Wed for increasing winds and seas. Vsbys lowering tonight in rain and patchy fog, improving Wed. Outlook /Thursday through Sunday/...Moderate Confidence. Thursday: Winds less than 25 kt. Areas of seas approaching 5 ft. Thursday Night: Low risk for Small Craft Advisory winds with local gusts up to 30 kt. Local rough seas. Chance of rain showers. Friday: Strong winds with local gusts up to 30 kt. Rough seas up to 10 ft. Friday Night: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas. Veterans Day: Winds less than 25 kt. Seas locally approaching 5 ft. Saturday Night: Winds less than 25 kt. Sunday: Winds less than 25 kt. Slight chance of rain showers. && .CLIMATE... High temperatures Friday Nov 10 may approach record cold max temps. Here are the current record coldest max temps: Boston 37 (1873) Providence 34 (1956) Hartford 37 (1914) Worcester 32 (1956) && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 7 PM EST Wednesday for ANZ232>235- 237. Small Craft Advisory from 4 AM to 4 PM EST Wednesday for ANZ231. Small Craft Advisory until 6 AM EST Thursday for ANZ250- 254>256. Small Craft Advisory from 1 AM Wednesday to 6 AM EST Thursday for ANZ251. && $$ SYNOPSIS...WFO New York NEAR TERM...KJC SHORT TERM...WFO New York LONG TERM...WFO New York AVIATION...Belk/WFO New York MARINE...Belk/WFO New York CLIMATE...
Area Forecast Discussion...UPDATED
National Weather Service Corpus Christi TX
921 PM CST Tue Nov 7 2017 .DISCUSSION...KCRP radar indicates the cold front has moved into the northern portion of the forecast area, from Victoria to Choke Canyon Lake to Dilley. Front continues to move south at around 15 mph. Latest MSAS analysis shows the strongest pressure rises from the Hill Country to the I-10 corridor between San Antonio and Houston. Derived image from GOES 16 shows higher moisture over the coastal plains in advance of the front with PWAT values around 1.5 inches. But radars are showing only very weak showers forming in the post-frontal area. Latest HRRR and Texas Tech WRF along with GFS expected a bit more coverage of light showers with the front by this time. Will lower PoPs to slight chance for the overnight hours. With front pushing south a little quicker, made adjustments to temperatures. With cloud cover and cold air advection, the northern part of the forecast area should not make it out of the 50s. A refreshing change for Wednesday after spell of well above normal temperatures in the 90s. No changes made to PoPs for Wednesday but lift may not reach the area until the afternoon with the approaching short wave trough. && .PREVIOUS DISCUSSION... /Issued 552 PM CST Tue Nov 7 2017/ DISCUSSION...See Aviation section for 00Z TAFs. AVIATION...Cold front just south of the I-10 corridor continues to move south at around 15 mph. Expect frontal passage at VCT around 03Z. Low MVFR ceilings from 1000-1500 feet will be prevalent behind the front. Scattered light showers will be possible for a few hours behind the front as well. The front is expected to reach the CRP-ALI area around 09Z and LRD by 11Z. Ceilings will persist around 1500 feet after the front Wednesday with gusty north winds. Isolated showers will be possible Wednesday morning with coverage increasing from the west during the afternoon as an upper level disturbance moves into the Hill Country. && .PRELIMINARY POINT TEMPS/POPS... Corpus Christi 61 63 54 64 53 / 20 30 60 30 20 Victoria 56 58 51 65 49 / 20 20 60 20 10 Laredo 61 64 52 60 53 / 20 30 40 20 10 Alice 60 62 51 63 51 / 20 30 60 20 20 Rockport 61 63 54 67 54 / 20 30 60 20 10 Cotulla 57 59 51 64 50 / 20 40 40 10 10 Kingsville 63 64 53 63 53 / 20 30 60 30 20 Navy Corpus 65 67 56 65 58 / 20 30 60 30 20 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ TMT/89...SHORT TERM
Area Forecast Discussion
National Weather Service Green Bay WI
541 PM CST Tue Nov 7 2017 Updated aviation portion for 00Z TAF issuance .SHORT TERM...Tonight and Wednesday Issued at 148 PM CST Tue Nov 7 2017 The latest RAP analysis and satellite/radar imagery show high pressure centered from the northern Rockies to the Great Lakes early this afternoon. Mid and high clouds have moved out of Wisconsin and into northern Illinois, while backing winds have caused lake effect clouds to retreat north out of north-central WI. The next cold front is digging southeast across central Canada, with mid and high clouds already approaching the northern MN border. Because impacts from this next system are not expected to arrive until Wednesday night, concerns mainly revolve around cloud cover and temps in this part of the forecast. Tonight...High pressure will slide to the southeast into the Central Plains at the same time as the next cold front approaches northern Minnesota by early Wednesday morning. Will see cirrus increase from northwest to southeast starting around late in the evening. Because the pressure gradient will remain relatively tight, chances for the wind to decouple look low. So think temps will not have an opportunity to tank despite the very dry arctic airmass in place. Have therefore remained conservative with temps, with lows ranging from the mid teens in the north to the mid 20s in the southern Fox Valley. Wednesday...The cold front will move into northwest Wisconsin by late in the afternoon. Deeper cloud cover will reside behind the front, so the threat of precip should hold off until evening. Will otherwise see periods of scattered to broken cirrus overhead for much of the day. High temperatures will range from the low 30s in Vilas County to the lower 40s near the Lake. .LONG TERM...Wednesday Night Through Tuesday Issued at 148 PM CST Tue Nov 7 2017 An active weather pattern is in store for Wednesday night into Thursday as the upper level trough moves through, accompanied by very strong cold air advection. A shortwave will help lend some instability to the region, making Snowfall likely for much of northeastern Wisconsin in the early morning hours on Thursday. The primary focus during this time period and into Friday however, will be far northern Wisconsin where the mesoscale influence of Lake Superior will make snow fall totals higher, especially for Vilas County. Higher snow totals will be possible in far northern Wisconsin if the winds currently forecast to be northwesterly take a more northerly turn. Strong cold air advection continues through Thursday, as 850mb temperatures are pushed to the -15C and colder range. Expect relatively minimal warming during the day on Thursday as cold air continues to flow across the region, keeping high temperatures well below normal. High pressure will rotate off towards the east by late Friday night, bringing a chance to see temperatures rise once more towards the beginning of the weekend. Southerly flow into the weekend will herald the next approaching trough for the region, as the next chance to see some active weather arrives. Snow is expected to return to the region on Saturday with the upper level trough, along with a fairly saturated column thanks to the southerly flow through the earlier parts of the day. Warming near the Fox Valley and lakeshore through this period may be sufficient for a switch to rain in the afternoon, before any lingering precipitation once again returns to snow towards the end of the day. Quieter conditions return by Sunday into Monday. Well below normal temperatures start on Thursday and linger on into Friday before southerly flow gets temperatures closer to normal by the end of the weekend. && .AVIATION...for 00Z TAF Issuance Issued at 500 PM CST Tue Nov 7 2017 VFR conditions will continue through Wednesday afternoon. Gusty winds also expected on Wednesday after 16z, with gusts to around 20 knots possible from the west. Winds will subside by 23z. Snow removal/salting operations will be needed Wednesday night into Thursday morning across northern Wisconsin. Snow arrives across the northern Wisconsin Wednesday evening and overspreads the remainder of the area early on Thursday morning. Highest snowfall totals expected across the far north with a dusting south of highway 10. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......Uhlmann AVIATION.......Eckberg
Area Forecast Discussion
National Weather Service Wilmington NC
931 PM EST Tue Nov 7 2017 .SYNOPSIS... A slow moving cold front nearly overhead tonight, will drop south of the area before stalling during Wednesday. Weak surface lows will move along the stalled front bringing unsettled conditions through late Thursday. Strong Canadian high pressure will finally bring cool and dry conditions as it wedges strongly down the coast Friday thru the upcoming weekend. This will be the coolest weather so far for this Fall season with low temperatures this weekend near the freezing mark especially west of the I-95 Corridor. && .NEAR TERM /THROUGH WEDNESDAY/... As of 900 PM Tuesday...Embedded mid-level s/ws moving within fast 500mb flow, will help drive a sfc cold front, currently across the northern portions of the FA from Cherry Point across Lumberton to Bennettsville, southward across the FA and local waters overnight to a Charleston to Augusta line. The majority of the pcpn will be north of the front as it drops southward. Looking at overrunning type pcpn in the form of light rain and/or drizzle. Dynamics from one of those embedded s/ws will result in the best chances for pcpn occurring from late this evening through daybreak Wed, with the highest rainfall amounts of up to 0.15 inches, running along the northern border of the ILM CWA. Have worked the POPs close to the latest runs of the HRRR model. Temperatures will drop to their lows by daybreak Wed and not push much hier from there for Wed maxes. Previous................................................... As of 300 PM Tuesday...H5 zonal flow, with embedded impulses, will persist through tonight into Wed ahead of a positively tilted trough positioned to the west and northwest. A nearly stationary front was located just north of the forecast area. The zonal flow will inhibit any significant southward push of this boundary through the early evening. Developing low pressure off the Mid-Atlantic coast tonight will finally allow the front to push north to south across the area from 06-12Z Wed. While the post-frontal air-mass will not be dry much cooler temperatures are on tap. In fact, tomorrow`s high temperature will occur in the morning as cold air advection allows temperatures to fall during the day. Overall, Wednesday`s high temperature will be several categories below normal (normal is around 70 at the coast to the upper 60s inland). Rainfall chances will increase through the evening, but more-so overnight. Scattered to numerous showers, with isolated tstms possible will become increasingly stratified Wednesday. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 300 PM Tuesday...Chief weather caption this period, `cool and wet`, as widespread, post-frontal over-running strengthens Wednesday night, ahead of an approaching short-wave. Upper support and deepening moisture will bring the heart of QPF tallies on Thursday as the short-wave axis transits the area. Damp and blustery NE winds and overcast conditions will lessen diurnal temperature ranges this period and we essentially are looking at 40s and 50s most of this period to accompany the rain and periods of drizzle. Rain amounts Wednesday night through Thursday night will range from 3/10ths to 6/10ths, which after a period of relative dryness will be welcomed by the ground. Winds will on occasion gust to 25 mph at the beaches and ICW this period and the surf will be rough. && .LONG TERM /FRIDAY THROUGH TUESDAY/... As of 300 PM Tuesday...Very fall-like this period with high pressure dominating the synoptic regime. However, this high will likely develop as a wedge during the weekend bringing low clouds, abnormally cool temperatures, and periods of mist/drizzle possible, especially late Saturday into Sunday. Ahead of this wedge, Friday will likely be a pleasant day with temps near seasonable norms and abundant sunshine as the relatively low- amplitude flow blocks the cold air across New England from flooding into the Southeast. On Saturday, the surface high wedges down the coast while the mid- level flow amplifies downstream from a shortwave digging into the OH VLY. This creates much cooler temperatures and mins Saturday morning will fall into the low 30s, with frost possible away from the coast. Additionally, this setup supports an overrunning wedge, and while soundings and time-heights show only shallow moisture, some light showers are possible late Sat into Sun, along with temps well below climo. This shortwave will push a weak front across the Carolinas late Sunday into Monday eroding the wedge. The GFS/ECM diverge at this point with the GFS faster and drier with the FROPA, while ECM is slower and more moist. The key difference appears to be strength of the trough, but in the fast flow expect the GFS may be more correct and is preferred attm. Behind this front, cool and dry conditions will return with temps recovering to near climo by Tuesday. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... As of 00Z...A fairly significant cold front will drop south through the region through the overnight hours. Look for post frontal conditions of a moderate north wind, ceilings lowering to IFR, with deteriorating visibilities on Wednesday. FLO observations will be missing the visibility, so will not be amending for this condition. Wednesday will be a rather raw day with continued IFR conditions and northerly winds. Extended Outlook...Mainly MVFR ceilings/tempo IFR Wed with showers through Thursday. MVFR becoming VFR Friday and continuing through Sunday. && .MARINE... NEAR TERM /THROUGH WEDNESDAY/... As of 900 PM Tuesday...At the moment, the WSW to ENE oriented sfc cold front has reached the Cape Hatteras to Cherry point to Lumberton line. The front will continue to sink southward overnight, reaching the Charleston to Augusta line a few hours after daybreak Wed. The sfc pg will tighten after it`s passage and combined with CAA, looking at northerly winds in the 15 kt range occasionally to 20 kt and hier gusts due to the air-sea interaction with local SSTs still around 70 degrees. Significant seas will start off 1 to 3 ft and build only to 2 to 4 ft due to a limited fetch to build upon under northerly winds. Previous................................................... As of 300 PM Tuesday...Variable winds 10 knots or less will become southwesterly during the afternoon and evening. The wind will turn north-northeasterly and increase overnight for the Cape Fear waters, and toward day break for the southern waters. North to northeast flow will persist during Wednesday all waters as a ridge of high pressure takes hold across the Southeast U.S. Seas around 2 ft will prevail this afternoon, then increase in the wake of the front through Wednesday. Scattered to numerous showers possible tonight, with isolated tstms. SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 300 PM Tuesday...`Exercise Caution` or `Small Craft Advisory` conditions possible this period, as NE winds behind a cold front produce rough ocean conditions. Seas at a minimum of 3-5 feet expected, and closer to 3-4 feet SC waters, with occasional gusts to 25 KT certainly believable given relatively warm waters still in place. Not expecting an improving trend this period, as winds remain elevated 15-20 KT and gusty. Occasional rain and drizzle with mist may reduce visibilities to 1 NM or less at times. Dominant wave periods of 5-6 seconds will produce steep wave conditions. LONG TERM /FRIDAY THROUGH SUNDAY/... As of 300 PM Tuesday...High pressure ridging down the coast will keep N/NE winds ongoing across the waters late week and through the upcoming weekend. The strongest of these winds will occur late Friday and through Saturday, as the gradient pinches around the periphery of a short lived wedge setup. During this timeframe, wind speeds will climb to 20-25 kts and drive seas to 4-6 ft, and an SCA is likely. Otherwise, during Friday and Sunday, wind direction remains N/NE but with speeds at 10-15 kts and slightly lower amplitude wave heights, with a NE wind wave likely the dominant wave group in the spectrum. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...JDW NEAR TERM...DCH/SRP SHORT TERM...MJC LONG TERM...JDW/CRM AVIATION...DL
Area Forecast Discussion
National Weather Service Jackson MS
956 PM CST Tue Nov 7 2017 .UPDATE... Updated for evening discussion. && .DISCUSSION... Main focus tonight continues on the cold front slowly trudging southward through our area. Latest surface analysis and obs indicate the front located over far southeastern areas of the region, continuing its movement southward out of the CWA overnight. Cloudiness extending behind the front across most of the CWA along with a few showers will remain likely throughout the night. HiRes guidance suggests potential for shower development in areas along/near the I-20 corridor in association with a subtle disturbance embedded in the flow aloft swinging through during the hours just before daybreak. Fog does not appear to be as widespread a threat as previous nights but low stratus will be possible near the frontal boundary in southern locations. Cooler air has begun to filter in behind the front, with temps in the northern counties already in the low to mid 50s. Expect overnight low temps ranging from lower 50s in northern locations to upper 50s to around 60 in southern locations. Winds will become northerly areawide as the front clears the region. Prior discussion below: Tonight through Tuesday: Latest Rap and Satellite imagery showed flat ridging through the atmosphere. A slow moving cold front was slowly making its way across the region. Temperatures to the north of the front were in the 60s and upper 50s. To the south of the boundary readings were in the 70s to lower 80s. Area radars had showers just ahead of the front near TVR to approaching JAN to around GTR. For tonight latest CAM guidance shows some light rain developing from west to east overnight. The front will be positioned south of the region. Isentropic lift will bring back the rain ahead of an approaching shortwave. There may be some patchy fog in the southeast near the frontal boundary prior to dawn, but will lift by 14z. The light rain will increase in coverage on Wednesday as the shortwave pushes into the Lower Mississippi Valley. Rainfall amounts do not look very impressive. It should be a steady light rain that should soak into the soil some. Looking at temperatures lows will be in the lower 50s north to the lower 60s southeast. Highs on Wednesday will be more seasonable with readings from the middle 50s northwest to the middle 60s southeast. /17/ Wednesday night through early next week: The shortwave will be on our western doorstep by 00Z Thursday. Rain from this system will spread eastward overnight and will exit our region Thursday after dawn. The overall setup of this system suggests a more stratiform rainfall vs. convective and the models continue their downward trend of potential rain intensity. Therefore, the total precip amounts are not expected to be more than an inch across the area. As the system clears the area on Thursday, northerly surface flow continues to bring cooler temperatures to the region. Upper level flow shifts to zonal and through the rest of the week, temps remain very seasonal. On Sunday the next system is projected to affect us. Models continue to show some slight differences in evolution but agree that a cold front will pass through with some rain on Sunday at this point. This round of models did not necessarily show a reinforcing cold shot behind the front, but temps going into next week do appear to be near normal for this time of year. /10/ && .AVIATION... 00Z TAF discussion: A weak cold front, extending from NMM to ESF, will continue to slowly move south, finally pushing through HBG by 08/04Z. In its wake, MVFR/IFR ceilings with patchy fog will overspread all TAF sites and persist through the end of the period. /26/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 55 58 48 64 / 58 66 62 24 Meridian 57 61 48 64 / 47 59 64 34 Vicksburg 53 56 47 64 / 55 73 65 14 Hattiesburg 63 65 52 65 / 15 45 59 37 Natchez 55 57 48 63 / 26 58 59 19 Greenville 50 54 44 62 / 17 75 74 4 Greenwood 51 55 44 63 / 12 75 78 6 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$
Area Forecast Discussion
National Weather Service Melbourne FL
837 PM EST Tue Nov 7 2017 .UPDATE... Tonight...After 3 mornings with fog/stratus and a weakening high pressure ridge across the local area, persistence would argue for another round overnight. Generally, air masses that produce fog will continue to do so until replaced by different one. However, MOS has really backed off of fog formation. We did get a bit of an air mass change this afternoon as drier air above the surface mixed down and produced surface dew points several degrees lower than yesterday. The GFS forecast soundings don`t show low level saturation late tonight, but the visibility forecast from the HRRR model and local WRF still have a few areas of fog, so will maintain patchy fog in the forecast. Weakening northerly low level flow has been pushing a few light showers down the Gulf Stream. The HRRR and local WRF don`t show much shower activity lingering overnight, but will leave a small PoP for the far south coast into the early morning. && .AVIATION... VFR through this evening. MOS guidance does not show visibility and ceilings nearly as low as recent mornings. Therefore, have just a mention of MVFR in the TAFs, except at KLEE. The fog/stratus Wed morning will dissipate quickly again. && .MARINE... Tonight-Wednesday...Good boating conditions with weakening high pressure ridge over the waters. Winds will be less than 10 knots and seas 2-3 feet. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ Lascody/Sedlock
Area Forecast Discussion
National Weather Service New York NY
936 PM EST Tue Nov 7 2017 .SYNOPSIS... A weak wave of low pressure moves well south and east of Long Island through overnight. High pressure to the north gradually builds in Wednesday into Wednesday night. High pressure over the area on Thursday gives way to an approaching arctic cold front, which will pass through the area late Thursday night. High pressure then returns for the weekend before giving way to another frontal system late Sunday into Monday. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Have continued with slight speed up of system heading offshore to the ENE. Adjusted POPs down a little sooner as per latest radar trends, along with latest HRRR and RAP guidance. Also adjusted temps to go with latest trends which have been a bit colder for the overnight in N & NW sections. Northern zones in CT see a mix of rain and snow before precip ends with no accumulation expected as moisture exits as colder and drier air wraps in behind the departing system. Minimum temperatures will range from the upper 30s to lower 40s for NYC Metro Area and coastal regions to the lower 30s for locations far N/W of NYC. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... In the upper levels, there is a split jet structure. Polar jet moves into North Central U.S. Wednesday and into Great Lakes Wednesday night and subtropical jet will be moving eastward from Southeast into mid-Atlantic Wednesday through Wednesday night. Dry weather will prevail for Wednesday and Wednesday night. The surface low pressure area well southeast of the 40N/70W benchmark will move east farther out into the Atlantic. Have the clouds decreasing during the late morning and into the early afternoon now with high pressure gradually building in from the north. Have now gone with more clearing for Wednesday night with the high continuing to build in. The downward trend with winds will continue as well, making for more radiational cooling Wednesday night. Maximum temperatures Wednesday will be limited due to cold air advection from the backing of winds from low to mid levels. The NE flow will keep maximum temperatures in the upper 40s to lower 50s. A blend of 1/3 NAM12 and 2/3 ECS guidance was used. For Wednesday night, a blend of 1/2 ECS and 1/2 MET guidance was used that conveys a range of lows from mid and upper 20s for rural interior locations to low 40s in NYC. For Wednesday night there is forecast areas of frost and patchy frost across much of the region. Coastal CT and Suffolk County NY have patchy frost but there is potential this could expand in coverage in subsequent forecasts. && .LONG TERM /THURSDAY THROUGH TUESDAY/... ***Record Cold Friday Night*** A digging upper trough across eastern Canada and into the northeast quarter of the nation will send an arctic cold front through the area late Thursday night. There is a good likelihood of record cold Friday night with daytime highs Friday struggling to get out of the 30s most locations. Readings will be be 15 to 20 degrees below normal. Thereafter, the upper flow flattens with a more zonal flow to follow. This will allow for a gradual moderation of temperatures through early next week with a return to more seasonable temperatures. High pressure will prevail through the first half of the weekend and then retreats offshore Sunday ahead of a fast moving frontal system over the Midwest and Great Lakes. There are some timing and magnitude issues amongst the global models with this system with the GFS on the faster side of the envelope. Preference at this time was to go with model consensus forecast with the frontal system approaching the area Sunday night and then slowly passing to the east on Monday. There is a chance of showers from Sunday afternoon into Monday. Rainfall amounts appear to be light at this time. The 12Z ECMWF places more emphasis on the southern branch energy, with a slower progression of the system and higher rainfall amounts (up to half an inch). Model trends will be watched, but the nature of flow is more progressive and less amplified. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... Low pressure tracks well to the southeast of Long Island tonight. Weak high pressure builds in from the west on Wednesday. Primarily VFR this evening, with occasional periods of MVFR. Cannot rule out a few flakes of snow or sleet pellets mixed in with predominate rain through around 4-5z at northern/city terminals and 6-7z at Long Island/Eastern CT Terminals. Should then see a period of MVFR ceilings overnight, giving way to VFR throughout by around 12z Wednesday. Winds N-NNE mainly around 10KT overnight/Wednesday morning. Winds diminish and back slightly to more N-NNW by late Wednesday afternoon. Winds should become light and variable at inland terminals by late afternoon as well. .OUTLOOK FOR 00Z THURSDAY THROUGH SUNDAY... .Wednesday night-Thursday night...Most likely VFR, with a low chance of MVFR conditions Thursday afternoon/evening. S-SW winds G15-25KT possible Thursday evening. W-NW winds G20-30KT possible late Thursday night. .Friday-Saturday night...VFR. NW winds G20-30+KT possible Friday and Friday night. .Sunday...MVFR or lower possible. SW winds G15-25KT possible. && .MARINE... The pressure gradient tightens as a low pressure area moving well south of Long Island deepens tonight. The low tracks farther into the open Atlantic Wednesday while slightly deepening. Weak high pressure to the north will gradually build in Wednesday into Wednesday night. A gusty N-NE flow develops going into tonight with SCA wind gusts becoming likely for all waters. On the ocean, boundary layer winds mixing down could result in a few spots with some brief gales but not enough temporal or spatial coverage to warrant any gale headlines. Otherwise, expect SCA conditions to continue tonight and then lingers mainly on the ocean for Wednesday, although expect some SCA gusts on Eastern Long Island Sound and Eastern Long Island Bays for Wednesday morning. Conditions lower to below SCA Wednesday night with winds as the pressure gradient decreases with high pressure gaining control but the ocean seas will likely remain elevated in SCA range. So SCA headlines are as follows: All waters for tonight, ocean and Eastern Long Island Sound and Eastern Long Island Bays Wednesday morning, and then just the ocean for the rest of Wednesday and Wednesday night. Conditions should remain below SCA on the waters Thursday as weak high pressure continues to be across the waters. An arctic front will cross the region late Thursday night, with SCA conditions expected on all waters into Friday evening. There is a low potential for gale gusts. Conditions will improve Saturday as high pressure builds into the region with conditions forecast to return to sub SCA. && .HYDROLOGY... QPF is expected to range between 1/3 and 3/4 inch through early Wednesday with no hydrologic impacts expected. Rainfall amounts Sunday night into Monday are forecast to be under a quarter inch. The 12Z ECMWF is more aggressive with a slower frontal wave with the potential for higher rainfall amounts. Model trends will be watched, but the nature of flow is more progressive and less amplified. && .TIDES/COASTAL FLOODING... In spite of a northerly flow, an average of guidance plus current anomalies points to the likelihood of minor coastal flooding during Wendesday`s late morning to early afternoon high tide cycle as low pressure pulls away to the southeast. Minor coastal flooding is expected along the South Shore Back Bays of Nassau County, Queens and Brooklyn as well as along parts of southern NY Harbor. An advisory has been issued for these locations, and a statement has been issued for southwestern Suffolk county where minor flooding is expected to be isolated and barely met. Statements or possibly even advisories may be needed for the high tide cycle near noontime for Southern Nassau and Southern Queens. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...Coastal Flood Advisory from 10 AM to 1 PM EST Wednesday for NYZ074-075-178-179. NJ...None. MARINE...Small Craft Advisory until 6 AM EST Wednesday for ANZ335-338- 345. Small Craft Advisory until noon EST Wednesday for ANZ330-340. Small Craft Advisory until 6 AM EST Thursday for ANZ350-353- 355. && $$ SYNOPSIS...JM/DW NEAR TERM...JE SHORT TERM...JM/JE LONG TERM...DW AVIATION...Maloit MARINE...JM/DW HYDROLOGY...JM/DW TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Mount Holly NJ
951 PM EST Tue Nov 7 2017 .SYNOPSIS... Low pressure emerges off the Mid-Atlantic coast early this evening, then moves out to sea through tonight. High pressure builds into our region Wednesday before weakening during Thursday. A strong cold front moves through Thursday night followed by cold Canadian high pressure on Friday and Saturday. The next cold front moves through late Sunday into Monday, then high pressure returns for Tuesday. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Precipitation continues to move to the east this evening and should gradually move towards the coast and offshore through tonight. Snowfall totals have been around an inch in parts of the Southern Poconos with snow reported mainly in the higher elevations. The surface low remains to our south and will continue to lift northeast and away from the region through the overnight period. The low appears to be in good agreement with the GFS and RAP and we continue to follow that guidance. Temperatures overnight will remain cold, especially across the north, with lows in the upper 20s to lower 30s. As you head south of I-78, temperatures will remain more in the mid 30 to lower 40s, with mid 40s along the southern NJ and DE coasts. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... As the low moves further away, drier and cooler air will move into the region. The one exception is in southern DE, where rain may linger through the day thanks to continued onshore flow. Any precipitation during the day tomorrow though should be light. Temperatures tomorrow should be slightly below normal, with highs ranging from the mid 40s to lower 50s. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... Summary...Strong cold front Thursday night ushers in arctic air for Friday and Saturday, followed by some moderation through early next week. Synoptic Overview...A potent upper-level trough arriving into the Pacific Northwest Wednesday night into Thursday builds a ridge into western Canada. This forces a significant digging trough downstream, which overtakes the Great Lakes and Northeast at the end of the week before lifting out over the weekend. The flow looks to briefly turn more zonal before another upper-level trough arrives late in the weekend into early next week. A couple of cold fronts look to move through; a strong one Thursday night then another arrives later Sunday into Monday. The first cold front will deliver a shot of arctic air for a couple of days. For Wednesday night and Thursday...A short wave trough will shift offshore Wednesday night, allowing low pressure offshore to move farther away. This should be far enough south and east to keep the lingering northwestern edge of the rain pretty out of our area to start Wednesday night. Otherwise, surface high pressure builds into the area overnight Wednesday before gradually shifting east and weakening during Thursday. A potent upper-level trough will be digging across the Great Lakes Thursday and then the Northeast at night. This will drive surface low pressure to our north, however a strong cold front will sweep through Thursday night. The main forcing looks to be tied to the northern part of the front closer to the surface low, with the guidance indicating the potential for a narrow line of low-topped convection with it. This may glance our northwestern zones Thursday night, however the moisture with a southern extent looks to be more limited. The main impact with this front will be a strong surge of cold air advection in its wake, along with substantial dry air advection. This will set the stage for much colder air arriving. For Friday and Saturday...As a robust upper-level trough swings across New England Friday, deepening surface low pressure will be north of New England while surface high pressure builds across the Great Lakes and Ohio Valley. This will allow for a tight pressure gradient across our region within a cold air advection regime. The end result will be a gusty north-northwest wind during Friday with peak gusts to around 30 mph. The airmass looks very dry, characteristic of arctic origin, therefore dew points will be down into the teens and even single numbers. The center of the surface high builds in Friday night and Saturday, allowing the winds to diminish. The airmass will be rather cold already, however if the winds decouple enough or even faster Friday night then temperatures will be even colder. At least the more sheltered areas should see a drop off in the winds quicker and therefore went a bit colder with the low temperatures. Our current forecast places some record low temperatures in jeopardy for early Saturday morning. Overall, a widespread hard freeze is expected Friday night. The growing season is still technically active for extreme southeastern Pennsylvania, southern New Jersey, Delaware and northeastern Maryland. As a result, the need for a Freeze Watch to Warning is expected. Daytime high temperatures for both of these days are expected to only be in the 30s and 40s. For Sunday through Tuesday...High pressure retreats eastward with its center mostly becoming situated close to the Canadian Maritimes Sunday. The earlier zonal flow amplifies with an upper-level trough moving through the Great Lakes region on eastward Sunday into Monday, driving a cold front across our area late Sunday. There are some differences among the model guidance on the strength of this feature and how much precipitation occurs. We will maintain some chances for precipitation with it, however it may be delayed some to allow for enough warming to prevent any frozen/freezing precipitation up north at the onset. High pressure then builds into our area during Tuesday as the flow may tend to become more zonal. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Tonight...Occasional MVFR/IFR visibility and ceilings will continue through at least 03Z. After 03Z, the rain is expected to taper off from west to east. As the rain ends, there may be a brief period of MVFR visibilities but overall most areas should see rapid improvement. Ceilings may take longer to clear than the visibilities but should gradually return to VFR by 12Z. However, at KACY and KMIV persistent onshore flow could help to keep the low clouds through the overnight and into early Wednesday. North to northeasterly winds will be around 10 to 15 knots this evening with gusts up around 20 knots possible, mainly at KACY and KMIV. Wednesday...MVFR conditions early should clear quickly and become VFR. However, with the prolonged north to northeast flow, KACY and KMIV may see MVFR conditions linger through the morning and possibly into the afternoon, especially at KACY where VFR may not occur until later in the day. Northeast winds around 10 knots or less across the terminals. OUTLOOK... Wednesday night and Thursday...VFR with ceilings at times mainly at and above 5000 feet. Northeast winds 5 knots or less becoming southwest Thursday afternoon, then west to northwest Thursday night and increasing to near 10 knots. Friday and Saturday...Mainly VFR. North-northwest wind gusts to around 25 knots Friday, then lighter winds Friday night and Saturday. Sunday...Possible times of MVFR conditions with a chance of showers. && .MARINE... SCA conditions are imminent on both the Delaware Bay and the coastal waters. On the DE and southern NJ Atlantic coastal waters, gale force gusts are likely after 00Z through at least 06Z. For the remainder of the area, gusts are expected to be around or below 30 KT. Winds should begin to subside by day break, and the Bay may be below SCA criteria as early as late Wednesday morning. On the coastal waters however, SCA conditions are expected to continue through the day. OUTLOOK... Wednesday night and Thursday...The winds and seas will be diminishing, however a Small Craft Advisory may be needed for a time especially for the Atlantic coastal waters zones. Thursday night through Friday night...Small Craft Advisory conditions are expected due to strong cold air advection and deeper mixing. North-northwest wind gusts up to 30 knots are anticipated, however around daybreak Friday some gusts could reach to low-end gale force. The winds gradually diminish Friday night as high pressure arrives. Saturday and Sunday...No headlines are anticipated as high pressure initially over the area shifts to our northeast and east through Sunday. && .TIDES/COASTAL FLOODING... A Coastal Flood Advisory was issued for the NJ and DE coast, including the DE Bay, with minor tidal flooding expected to occur with the Wednesday morning high tide. The astronomical tides continue to remain high. With the continued north to northeast wind on Wednesday, we will maintain a surge of between 1/2 and 1 ft above the astronomical tide. && .CLIMATE... Record low temperatures for Saturday morning for several of our sites are forecast to be challenged. The extent of the cold however will depend on how quick the winds diminish Friday night as high pressure builds in. The daily record low temperatures for 11/11 are listed below for all of our climate sites. Site Daily Record Low Year Set Temp for 11/11 (F) ACY 22 1973 PHL 21 1961 ILG 22 1961 ABE 19 1954 and 1956 TTN 25 1973 and 1987 GED 21 1973 RDG 18 1973 MPO 11 1956 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...Coastal Flood Advisory from 9 AM to 4 PM EST Wednesday for NJZ012>014-020>027. DE...Coastal Flood Advisory from 9 AM to 4 PM EST Wednesday for DEZ002>004. MD...None. MARINE...Gale Warning until 6 AM EST Wednesday for ANZ452>455. Small Craft Advisory until 6 PM EST Wednesday for ANZ431-450- 451. Small Craft Advisory until noon EST Wednesday for ANZ430. && $$ Synopsis...Gorse Near Term...Johnson/Meola Short Term...Johnson Long Term...Gorse Aviation...Gorse/Johnson/Meola Marine...Gorse/Johnson Tides/Coastal Flooding... Climate...
Area Forecast Discussion
National Weather Service Shreveport LA
1002 PM CST Tue Nov 7 2017 .DISCUSSION... The cold front has finally cleared the region to the S into far SE TX and Cntrl LA this evening, with the post-frontal cooler air slowly beginning to deepen in its wake across the area. A considerable post-frontal stratus shield will linger overnight though, which should help limit the extent of the temp fall as the cold advection weakens. The regional mosaic radar imagery indicates sct areas of -RA over Cntrl TX migrating E into portions of Deep E TX, although the sfc obs have not reflected much of any of this actually reaching the ground. The latest run of the HRRR suggests that this -RA should continue to spread E into Ncntrl LA after 06Z as ripples in the zonal flow aloft over the Srn Plains/Lower MS Valley continues to shift E. However, our focus will shift to our W late tonight as areas of SHRA develops over Wrn and N TX, ahead of an upper trough now entering the Four Corners Region. Isentropic forcing along the 300-310K surfaces will begin to spread E across N TX late tonight/Wednesday morning, some of which will begin to spill into portions of NE TX/SE OK/SW AR. The HRRR is most aggressive with the SHRA, although the latest run has backed off on this (more in consensus with the 00Z NAM/18Z GFS), and thus have maintained mid chance pops for these areas. Did lower pops a tad elsewhere to low chance given the lesser deep lyr forcing/lack of isentropic lift, but SHRA should quickly ramp up from W to E Wednesday morning as the isentropic forcing spreads E near and N of the H850 front over Deep E TX/Cntrl LA. Given the QPF consensus amongst the short term progs, have maxed out the categorical pops across much of NE TX/Srn AR/Extreme Nrn LA, with temps not expected to recover much during the day from the morning low temps. As for min temps, did make some minor downward tweaks per the 03Z obs, which were 1-2 degrees cooler than the gridded temps. Otherwise, the remainder of the forecast is in good shape. Zone update already out...grids will be available shortly. 15 && .PREV DISCUSSION... /issued 555 PM CST Tue Nov 7 2017/ AVIATION... For the 08/00z TAFs, IFR flight conditions already prevail in most areas with the exception of KTYR and locations in Texas and Louisiana south of Interstate 20. However, ceilings and visibilities will continue to deteriorate, and IFR conditions should prevail areawide by 08/06z. Patchy fog, light rain, and drizzle is also likely across much of the area. A large area of rain will develop and spread eastward across the region after 08/12z. All TAF sites will be affected by the rain, and the precipitation should persist through at least the end of the period. IFR, and occasional LIFR, conditions will also persist. CN && .PRELIMINARY POINT TEMPS/POPS... SHV 52 54 45 62 / 30 100 80 10 MLU 52 54 46 63 / 30 90 80 10 DEQ 50 50 40 62 / 40 90 50 10 TXK 49 51 43 61 / 40 100 60 10 ELD 49 52 42 61 / 30 100 80 10 TYR 48 52 46 60 / 30 100 80 10 GGG 51 53 45 61 / 30 100 80 10 LFK 55 58 49 62 / 30 90 80 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 15/09
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