Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/12/19

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
531 PM MDT Wed Sep 11 2019 .AVIATION... 00Z TAF CYCLE W/SW flow continues over much of the state with a lee side sfc trough moving toward E/NE over southeastern CO this hour. Peak gusts of 25-35kts are beginning to subside into the 15-25kt range with the end of peak heating. As such, two areas of isold-sct ts activity over the northern mtns near KSKX and KLAM as well as over the caprock from KROW to KCVN will slowly diminish over the coming hours to 01Z-03Z. Much drier mid-level air has moved into western NM and will continue its progression into central and eastern NM Thursday, diminishing chances for afternoon ts activity. 24/RJH && .PREV DISCUSSION...338 PM MDT Wed Sep 11 2019... .SYNOPSIS... A Pacific front and increased moisture resulted in isolated to scattered thunderstorm activity across the state today. Drier air is beginning to move in from the west and will limit showers and thunderstorms on Thursday, except across the southeast and east central plains. Following a backdoor cold front late Thursday, increased moisture and cooler temperatures are possible into the weekend. A disturbance arriving Sunday looks to be particularly wet across western and central areas of the state. && .DISCUSSION... An approaching trough has drawn a stream of moisture northward, bringing low clouds and isolated to scattered thunderstorm activity across the state. This morning`s 12z sounding near Albuquerque showed precipitable water values over an inch. The HRRR and HREF are in good agreement for some thunderstorm activity in the metro area after 6 pm this evening. The northeast is once again favored for moderate instability (CAPE ~1500 J/kg, steep low-level lapse rates, and 0-6 km bulk shear 20-25 kts. Stronger storms may produce gusty winds, in addition to small hail and locally heavy rainfall. However, area of greatest risk shifts eastward after 03z as the boundary shifts. Showers and thunderstorms will favor the southeast and east central portions of the state Thursday, where enough moisture should spark some activity. Overnight lows going into Thursday will be the coolest since June west of the central mountain chain, as cold air is advected in the wake of the Pacific cold front. Highs across the northeast will be several degrees below normal, following impacts from a backdoor cold front. Southeast return flow will bring enough low-level moisture to produce precipitation east of the central mountain chain Thursday evening. Temperatures remain cooler across the east for Friday. The high will shift east of the state, drawing additional moisture northward for the weekend and early part of next week. A disturbance Sunday and Sunday night may further increase storm chances across western and central portions of the state Sunday night into Monday. It looks to be an active early part of next week; however, the GFS and NAM have begun backing off on a wetter solution. Decided to go with the middle road and stick more with the ECMWF and keeping at least chance showers in the forecast. 31 && .FIRE WEATHER... Showers and storms will continue to progress to the northeast over central and eastern New Mexico this afternoon and evening in advance of an upper trough and associated cold front. Breezy to windy conditions central and east will persist into the early evening before decreasing. Drier air will be infiltrating western and northern New Mexico tonight, leading to cooler overnight low temperatures as well as fair to poor humidity recoveries northwest and portions of the Rio Grande Valley. Thursday will be the driest day of the rest of this week and early next week as the drier air in the wake of the upper trough spreads farther east and south. However, moisture will linger south of Interstate 40 and east of Interstate 25 and a weak cold front sagging into the eastern plains will produce sufficient upslope flow to trigger a few showers and storms over the east Thursday afternoon. The cold front and showers and storms will spread westward to the central mountain chain Thursday night, while portions of west central and northwest New Mexico will continue to see fair to poor overnight humidity recoveries. Deeper moisture will gradually work it`s way west of the central mountain chain Friday and over the weekend, spreading increasing potential for wetting convection over central and western New Mexico especially Sunday and Monday. High temperatures will be within a few degrees of normal but lows will be mostly warmer than average. Next Tuesday and Wednesday could be quite unsettled if a deep upper trough tracks through the central and southern Rockies as both the GFS and ECMWF indicate. && .ABQ WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service State College PA
801 PM EDT Wed Sep 11 2019 .SYNOPSIS... A frontal system will approach the region this evening. Ahead of it will be muggy conditions with a change of showers and thunderstorms. The front will then stall along or just south of the Maryland border. Another frontal system will weaken as it moves into the area Saturday. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Warm and muggy conditions this afternoon with radar showing the first signs of convection developing over western areas of the region this afternoon. Will keep pops in the forecast through the period. Later tonight convection currently over the Great Lakes will approach the NW zones. Look for a muggy night with temperatures well above average. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... Frontal system will become stationary close to the MD border on Thursday. With easterly flow look for a good bit of cloud cover and cooler conditions then today. Will also keep some pops in the forecast, especially SE zones where low level moisture is greatest. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Models agree in building the eastern ridge with 5900m H5 heights moving into PA Thu night and Fri. Despite the warm bubble pushing in aloft, I have Fri as the coolest day of the next several with the big high to our NE keeping us in a cool ESE flow with plenty of clouds around. A new storm system will lift well to our west by the weekend, with the trailing cold front weakening as it encounters high heights over the eastern U.S. later Fri into Sat. The best chances for showers/thunderstorms will be over the western CWA. Right now it looks like the second half of Saturday will be drier than the first. Medium range guidance keeps us pretty close to the southern edge of the westerlies which casts doubt on the potential for rain through the extended. I chose a more optimistic precip forecast given the expectations of rather high heights aloft, suggesting the potential for rain will stay on the scattered disorganized side, too early to be specific about. A potentially interesting situation is hinted at next week with the upper high parked over the SE US. A wave in the Bahamas is brought under this ridge into the eastern Gulf of Mexico, with the ECMWF/GFS/Canadian all remarkably close in bringing a possible tropical cyclone toward the NE gulf states perhaps as early as later Monday. By the middle of next week there are hints that whatever moves ashore could be heading north up the Appalachians toward the OH Valley or NERN US, or at least a stream of deeper tropical moisture advecting up this way. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... Scattered convection this evening moving in vicinity of many TAF locations at 00z. While mainly VFR conditions exist, punctuated areas of of MVFR likely occurring directly under the thunderstorms. Included VCTS and VCSH in most TAF locations to capture current activity on the radar. HRRR indicates convection slowly wanes through 08z...with a lull into Thursday before more scattered convection fires. Again, best likelihood will be across central and northern airfields, with low chance across the southeast. Additionally, looking for some fog development overnight, with some lower stratus developing. Tomorrow, with the cold frontal passage, expect a decent broken stratus deck to develop in the wake of morning/early afternoon showers and thunderstorms. Again, coverage of precipitation may be limited. .Outlook... Fri-Sat...Low ceilings possible, mainly in the morning. Isolated afternoon SHRA possible. Sun-Mon...AM valley fog possible, otherwise no sig wx. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Ross NEAR TERM...Ross SHORT TERM...Ross/La Corte LONG TERM...La Corte/RXR AVIATION...Jung/Ross
Area Forecast Discussion
National Weather Service Des Moines IA
636 PM CDT Wed Sep 11 2019 .DISCUSSION.../Tonight through Wednesday/ Issued at 316 PM CDT Wed Sep 11 2019 Primary forecast concerns over the next 48 hours or so will be heavy rain potential over northern Iowa and perhaps down into northeast Iowa tonight and strong to severe storms as the cold front moves through the state on Thursday. Additional concerns with lesser expected impact will be stronger, gradient winds on Friday. Longer term, will have to keep an eye on Saturday if storms are able to form during peak heating over western Iowa with strong storms not out of the question. Morning showers and thunderstorms waned by midday today with ongoing recovery over the southern 2/3rds of the state early this afternoon. Convective allowing models (CAMs) did not perform well last night with regards to the strengthen of the cold pool and subsequent southward push of the storms to around I-80. This lends concern to placement of later convection tonight. Currently, deep western US trough is slowly moving eastward with broad southwesterly flow ahead of it over our region. A surface low will develop and lift northeast from eastern Colorado this evening to near southeast South Dakota by Thursday morning with a warm front lifting to around the Iowa-Minnesota border if not southern Minnesota by later this evening and farther into southern Minnesota by Thursday morning. Meanwhile, a lead shortwave trough will move over the region this evening with a strong, 925mb jet of 30 to 40 knots into central Iowa. This should all aid in the development of storms, especially over northern Iowa and points north tonight, especially near the front. Precipitable water values of 1.5 to 1.75 inches will be common with deep warm cloud depths owing to efficient rain processes. 850-300mb winds are generally around 20 knots and more orthogonal to the warm front, with the exception over northeast Iowa where they become more parallel. High resolution WRF NMM and ARW cores along with 12z HREF localized probability matched mean highlight this area with some higher rain totals of 4 to 7 inches by 12z Thursday with recent HRRR runs around 8.5 to 9.5 inches by the same time. However, these CAMs may be incorrectly initializing as they depict an outflow boundary that currently does not exist that the convection is suppose to later develop along. Much of the rest of the 12z guidance has lifted the heaviest rainfall farther north of the state. Therefore, in collaboration with the Weather Prediction Center, the moderate risk of excessive rainfall was pushed a bit farther north and they did extend the moderate into northeast Iowa given concern over some of the CAMs. The heaviest rainfall last night into this morning was over northwest Iowa with 1 to 2 inches common. Past week to two weeks shows the highest rainfall over many parts of western Iowa and over some parts of northeast Iowa with a minimum over north central Iowa around Mason City. Outside of an isolated urban flash flood threat, concern is not as great for flash flooding over north central or even northwest Iowa with either mature crops or the trend of the heaviest rainfall to be farther north. The only caveat here is if the models have not properly resolved the cold pool tonight, as was the case last night, which would place the heavier rainfall closer to our northern Iowa counties. This seems less likely given more synoptic features/forcing coming into play late in the period. The greater concern given antecedent conditions may end up over our northeast forecast area around Waterloo, but low confidence in this solution given the forcing of the modeled thunderstorms tonight in the high resolution WRF cores/HRRR. Will monitor near term, high resolution models and observations for possible flash flood watch if needed this evening. Thunderstorms should wane as the warm front lifts into southern Minnesota by 12z Thursday. Attention will then turn to the west as the cold front extends southward from the low pressure over southeast South Dakota. All of Iowa should get into the warm sector as the low moves into eastern North Dakota; however, a triple point may set up somewhere over northern Iowa leading to a small window for a few tornadoes. Forecast soundings near MCW show surface based convection with strong instability, low LCLs, and favorable helicity values supporting this idea. In addition, soundings across central Iowa show thick CAPE profiles in the hail growth region so large hail will be a concern and entrainment of stronger low level winds in thunderstorm downdrafts may lead to damaging wind gusts. While the overall flash flood risk on Thursday will be lower given the progressive nature of the storms, there will be a narrow ribbon pooling ahead of the cold front with precipitable water values around 2 inches. If an area has flash flooding tonight, a very localized, isolated flash flood risk may be possible tomorrow. Overall, this is a low probability. These storms are expected to exit the area by early Thursday evening west of I-35 and by mid to late evening for areas between I-35 and Highway 63 (essentially our forecast area of responsibility). Cold air advection will ensue behind the cold front with breezy winds from the west on Friday delivering cooler and drier air. Sustained winds of 15 to 25 mph with gusts to around 35 to 40 mph will be possible. High temperatures will be about 5 to 10 degrees lower than Thursday. More zonal flow will follow into the weekend with moderating temperatures to just above seasonal levels. Warm air advection coupled with QG convergence arriving on Saturday will likely lead to scattered thunderstorms if weak capping can be overcome, especially later in the day and at night. If storms do form in the afternoon, there is a chance they could become strong to severe given strong elevated instability and deep layer shear of 30 to 45 knots with the highest shear over northern Iowa. CIPS Experimental Analog-Based Severe Probability Guidance supports this notion showing a 15% area of severe over western Iowa. After Saturday, the zonal flow will begin to amplify with a ridge building over the central US. This will largely limit rain and storm chances with above normal temperatures through midweek. Another deep trough will enter the western US early next week and progress eastward through the first part of the week. As a surface cold front associated with this trough approaches the state later Thursday into Friday, this will bring the next widespread chance of thunderstorms to the region. && .AVIATION.../For the 00Z TAFS through 00Z Thursday evening/ Issued at 632 PM CDT Wed Sep 11 2019 Storms and low cigs will be the forecast challenge through the next 24 hours. MVFR cigs and thunderstorm activity looks to remain across northern Iowa this evening and overnight. TSRA may produce heavy rain at times. Cigs may drop as low as IFR at KMCW toward Thursday morning, but otherwise levels should remain within MVFR category. Another round of TSRA is anticipated Thursday afternoon and evening as a front sweeps through. Timing at each terminal remains in question, but have included a broad mention of vcts to highlight the potential. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...Ansorge AVIATION...Martin
Area Forecast Discussion
National Weather Service El Paso Tx/Santa Teresa NM
319 PM MDT Wed Sep 11 2019 .SYNOPSIS... Drier and more stable air will limit thunderstorm potential over most of the area this evening, though a stray shower or storm will be possible east of the Rio Grande. This drier pattern will continue on Thursday. However, thunderstorm chances will increase again Friday and through the weekend as moisture increases over the area again. && .DISCUSSION... Water vapor imagery shows a deep trough moving into the Northern Rockies, with drier W to SW flow aloft over Arizona and New Mexico continuing to push moisture out of the area. Surface dewpoints have managed to stay in the 50s over much of the area, and while RAP13 soundings and SPC mesoanalysis suggest moderate MLCAPE and little to no CIN, visible satellite imagery shows just shallow cumulus development over most of the area. The 12Z Tucson sounding showed a significant warm nose around 550mb, and it`s quite possible that we are warmer and drier aloft than the RAP analysis would suggest. We could still see a stray shower or thunderstorm over the Gila, or (slightly) more likely in Otero and Hudspeth County before the day`s end, but most areas will remain dry this evening. As the upper trough moves eastward into the northern Plains, the subtropical ridge will build back to the west, with its axis remaining south of the international border, and westerly flow persisting over AZ/NM. Thus expect the drier spell to continue tomorrow, with just an outside chance of a stray shower or thunderstorm well east of the Rio Grande. Increasing SE flow at the surface and low levels will lead to increasing moisture on Friday, especially east of the Continental Divide. Meanwhile, the mid-level ridge axis will begin to drift northwards, resulting in a reversal of mid-level winds to easterly, which will also allow for subtropical moisture south of the border to begin migrating northwards. This pattern will continue into the weekend, with increasing chances of afternoon showers and thunderstorms continuing. A deep and high-amplitude upper trough will move into the west coast on Tuesday, breaking down the western edge of the subtropical ridge, and increasing mid-level southwesterlies over our area on Tuesday. This will initially draw up more subtropical moisture into the area Tue-Thu, with a drying trend west-east late Thursday and into Friday as the main trough axis moves east of the Rockies. Head of the drying, however, increasing winds aloft may lead to more organized and stronger thunderstorms, particularly Tue/Wed as we transition into a more Autumn-like pattern. && .AVIATION...Valid 12/00Z-13/00Z... P6SM FEW-SCT080-100 SCT250 through 06Z with isolated 1-3SM TSRA BKN030-040 possible east of a KELP-KALM line. Skies turning SKC- SCT250 after 06Z. After 18Z FEW-SCT100-120 SCT200-250 with isolated 3-5SM -TSRA BKN060-080 over far east. && .FIRE WEATHER... Upper trough will be passing over the area tonight which will flush most of the moisture east of the Borderland for Thursday. This dry weather is not expected to last long as low level winds turn back to the east Friday and bring moisture back to the region. Isolated to scattered showers and thunderstorms are expected again starting Friday and continuing into early next week as another upper trough moves into the Pacific Northwest. Temperatures will be within a few degrees of average with relative humidities mainly above 25-30 percent except tomorrow which will be the driest when minimums fall to around 20-25 percent. Vent rates will be poor tomorrow but improve Friday as easterly winds increase over the area. && .PRELIMINARY POINT TEMPS/POPS... El Paso 71 94 71 90 / 0 10 0 30 Sierra Blanca 65 87 64 84 / 20 30 30 40 Las Cruces 65 91 66 88 / 0 0 0 40 Alamogordo 65 93 66 90 / 10 0 10 50 Cloudcroft 51 71 50 67 / 20 30 20 70 Truth or Consequences 64 91 65 90 / 0 0 0 30 Silver City 58 86 60 84 / 0 0 0 30 Deming 64 93 66 91 / 0 0 0 30 Lordsburg 63 91 65 91 / 0 0 0 20 West El Paso Metro 71 94 71 91 / 0 0 0 30 Dell City 66 94 66 89 / 20 20 10 40 Fort Hancock 71 95 71 91 / 20 20 20 30 Loma Linda 66 87 66 83 / 10 20 10 40 Fabens 70 93 71 89 / 10 10 0 30 Santa Teresa 68 92 69 89 / 0 0 0 40 White Sands HQ 67 92 68 89 / 0 0 0 50 Jornada Range 64 92 65 89 / 0 0 0 40 Hatch 64 94 65 91 / 0 0 0 30 Columbus 66 92 67 91 / 0 0 0 20 Orogrande 66 91 66 88 / 10 0 10 40 Mayhill 56 80 55 76 / 20 30 20 70 Mescalero 54 81 54 77 / 20 20 20 70 Timberon 55 78 54 74 / 20 20 20 60 Winston 53 84 54 83 / 0 0 0 30 Hillsboro 60 91 61 88 / 0 0 0 30 Spaceport 62 91 63 89 / 0 0 0 30 Lake Roberts 51 86 53 84 / 0 0 0 30 Hurley 58 88 61 86 / 0 0 0 30 Cliff 57 93 59 93 / 0 0 0 30 Mule Creek 58 88 60 88 / 0 0 0 20 Faywood 59 89 62 87 / 0 0 0 30 Animas 64 93 65 93 / 0 0 0 20 Hachita 62 91 64 91 / 0 0 0 30 Antelope Wells 62 91 64 91 / 0 0 0 30 Cloverdale 61 86 63 87 / 0 0 0 30 && .EPZ WATCHES/WARNINGS/ADVISORIES... NM...None. TX...None. && $$ 25-Hardiman / 26-Grzywacz
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
400 PM CDT Wed Sep 11 2019 .SHORT TERM...(This evening through Thursday night) Issued at 400 PM CDT Wed Sep 11 2019 Short term concern is mainly hydro concerns with a severe weather threat as well. Pesky upper trough slow to clear to the east with lingering light rain/drizzle mainly in western WI early. Then model trends continue to slow progression of next wave of moisture northeast overnight. Have timed PoP with HRRR timing for the most part. This brings convection along WAA zone into southwest MN mainly after 02z and then northeast toward east central MN through about 08z and then into WI by 12z or so. Does appear to be a couple of waves of precipitation tonight as whatever complex develops into eastern South Dakota, moving east behind the initial rain band. Last night 1.5 to 2.5 inch rain was mainly confined to about the southern third of the CWA. This area will be prime for rapid runoff and flash flood potential later tonight into Thursday. Complex rides east along and ahead of surface warm front which lifts into southern MN overnight. Still see nearly PW`s to 3 standard deviations above normal over the area tonight into Thursday. This combined with forcing with the actual trough and surface cold front, should yield heavy rain potential. QPF forecast has another general 1.5 to 2.5 inches with a max of 3 inches possible near the metro in east central MN. Have coordinated a flash flood watch across much of central, into south central MN for tonight into Thursday. The front moves east Thursday and should develop more convection by midday to the east. Still think there will be heavy rain potential with this as well as it exits into west central WI by late afternoon. Will need to monitor overall trends, but confidence is rising that the current watch may need to be expanded a bit farther to the east. If we indeed get organized convection along the front. The severe threat would be mainly wind over the southwest during the late evening. That should gradually weaken as it moves farther east as the initial WAA advection moves northeast. Severe threat Thursday is a bit conditional. We will need some heating to generate instability ahead of the front. That looks limited however with extensive cloud cover continuing. Expect the front to exit into western WI by evening, leaving clouds and increasing W-NW winds on the backside later Thursday night. A few wrap around showers also possible as the upper low/trough exits. .LONG TERM...(Friday through Wednesday) Issued at 400 PM CDT Wed Sep 11 2019 The surface low responsible for the active weather today and tomorrow departs north into Ontario Friday morning, with the thunderstorm and heavy rain threat departing to the east. Scattered light wrap-around showers look possible during the morning and into Friday afternoon, primarily across central Minnesota. The main weather impact on Friday will be the gusty winds during the day with the tightening pressure gradient over the area and strong subsidence behind behind the cold front allowing westerly winds of 30-40 mph to mix down to the surface. Cold advection will limit highs to the upper 50s-upper 60s despite clearing skies Friday afternoon. Guidance has trended a little stronger with the shortwave passing through northern Minnesota/Wisconsin on Saturday, and have raised PoPs Saturday afternoon into the evening. Models depict a corridor of 1000-2000 J/kg of MLCAPE advecting into west-central Minnesota along with effective bulk shear values of 30-40 kts, so the potential exists for some stronger/more organized storms with those that do develop. Thunderstorms could develop north of this instability corridor into saturday evening along the nose of the LLJ. Drier and warmer weather develops Sunday into early next week as anomalously string ridging builds into the Great Lakes region. The GEFS and ECE ensemble means have 850 mb temperatures of 20-24 C nosing into the area Monday and Tuesday, which would be in the 95- 99th percentile for mid-September. Highs look to easily reach into the 80s across most of the area, with some upper 80s and even a few 90s possible across western Minnesota should peak mixing be realized. precipitation chances return mid-week as the ridge departs to the east and a trough approaches out of the plains. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 1250 PM CDT Wed Sep 11 2019 Weakening upper trough exiting to the east. Some residual FGEN forcing over east central MN trailing into west central WI enough to continue -ra a couple hours or so. IFR/MVFR cigs with next shot of thunder/ra moving into mainly southwest MN after 02z or so. Will time using the current HRRR which seems to have a decent handle of overall expected development. Should lift to east central MN by 08z and then exit into WI in the morning. CIGS look to remain IFR much of Thu morning as well, ahead of surface cold front. KMSP...Residual shra exiting to the east early with next shot of trsa moving in mainly after 08z. May have a break early Thu morning before redevelopment by 17z-18z expected. /OUTLOOK FOR KMSP/ THU night...MVFR/IFR. chc SHRA. Wind SW at 10-15 kts. FRI...VFR. MVFR possible. Wind W at 20G30 kts. SAT...VFR. Chc MVFR/TSRA. Wind S at 10G20 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...Flash Flood Watch from 1 AM CDT Thursday through Thursday evening for MNZ059>063-066>070-074>078-082>085. Flash Flood Watch from 9 PM CDT this evening through Thursday morning for MNZ054>058-064-065-073. && $$ SHORT TERM...DWE LONG TERM...ETA AVIATION...DWE
Area Forecast Discussion
National Weather Service Marquette MI
700 PM EDT Wed Sep 11 2019 .SHORT TERM...(This evening through Thursday) Issued at 241 PM EDT WED SEP 11 2019 Per RAP Analysis, today`s rain-making trough is currently stretched from near Munising to near Washington Island. Rain is just working it`s way into the eastern UP this afternoon and much of the Keweenaw Peninsula has also remained mostly dry, but with the mid-level forced rain combined with the low level, orographic enhanced drizzle over the northern tier, most areas have seen A rather gloomy day. Only Newberry has seen temperatures hit 60 this afternoon with most locations moored in the 50s today. Rain showers will gradually end this evening, exiting Menominee and Delta Counties last after about 10pm Eastern. Some fog redevelopment looks possible, but will be dependent on whether or not winds are able to fully decouple; regardless low stratus is expected. While cloudy, relatively gloomy conditions are expected to continue into Thursday, the progression of the next deep trough is now slowed quite a bit from the previous forecast issuance. POPS have been reduced tomorrow accordingly. While winds will turn to the east, low level moisture will remain in place, perhaps as deep as 4km, which will likely allow for additional drizzle in Marquette County. A few scattered showers cannot be ruled out during the morning and early afternoon near the Wisconsin border, however the bulk of the precipitation is not expected to move into western Upper Michigan until the mid to late afternoon. At this time, instability looks to lag behind this initial round of pre-warm frontal rain so no thunder is expected. Slightly below normal temperatures will remain in place with highs in the upper 50s to the mid 60s. .LONG TERM...(Thursday night through Wednesday) Issued at 401 PM EDT WED SEP 11 2019 Top "story" for this forecast period continues to be the approach/crossing of a deepening low associated with an amplified trough from the Northern Plains into NW Ontario tomorrow night into Friday. Copious PWAT values accompanying this system will allow for widespread moderate to locally heavy rain to fall, primarily tomorrow night into early Friday. Once the low passes to the north late Friday, the precip will go right along with it, with any lingering wrap-around showers on the backside of the low likely gone by early Saturday. Look for a break in the active weather for much of the day on Saturday, with showers/storms returning late Saturday into early Sunday as the next shortwave traverses through. This weaker system should be fairly quick moving, with another break occurring early next week. Although still fairly far out in the forecast, the next deep trough looks to bring in a renewed unsettled period starting around the middle of next week. The general trend for temperatures will be on the increase into next week, rising above normal for mid-September by this weekend. Are near-record highs going to occur early next week? It doesn`t look entirely out of the question for next week with highs perhaps reaching well into the 70s, near the 80 degree mark. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 700 PM EDT WED SEP 11 2019 Ample low level moisture will continue to lead to IFR/MVFR conditions at all sites overnight. Conditions will improve to VFR by Thu afternoon at all sites except at IWD which will improve to MVFR. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 309 PM EDT WED SEP 11 2019 Northeast winds of 15-25 knots continue today as Lake Superior remains in between a high pressure system to our north and a developing low across the Central Plains. Strongest wind gusts will reach up to 30 knots across the far western lake through this evening. By Thursday, the pressure gradient will strengthen, increasing wind gusts to just under gale criteria over the west half. These winds will become southeasterly and spread across the rest of the lake Thursday night as the low moves through MN into Ontario, and there remains a good chance that winds will reach into gale criteria, with up to 40 knot gusts possible. A Gale Watch remains in place for the central and eastern portions of the lake. During the day Friday, winds will shift to southwesterly, and by Friday night wind gusts approaching gale criteria will again be possible over the west half of the lake. By Saturday afternoon, the gradient relaxes allow winds to fall back below 20 knots for the remainder of the forecast period. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Gale Watch from Thursday evening through Friday morning for LSZ249>251-266-267. Gale Watch from Thursday evening through Friday morning for LSZ243>246-263>265. Lake Michigan... None. && $$ SHORT TERM...KCW LONG TERM...lg AVIATION...07 MARINE...KCW
Area Forecast Discussion
National Weather Service New York NY
820 PM EDT Wed Sep 11 2019 .SYNOPSIS... A cold front will slowly pass through the area late tonight into Thursday morning. High pressure will then build across the northeast Thursday and slowly offshore on Friday. A warm front and weakening cold front will pass through on Saturday before high pressure returns into next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Convection across NE PA this evening has struggled to move east into NJ. The forcing remains weak over the area and shear is weak. A cold front and pre-frontal trough will continue to approach from the NW, but any shower or thunderstorm looks to remain isolated this evening. Marginal instability will persist through midnight and a shower or thunderstorm could develop as the front moves into the area. A shortwave will also approach around day break and this could help develop a few showers. Have raised PoPs to chance after 08z to account for this potential of showers. Instability should diminish with no thunder mentioned beyond 08z. Overnight lows will be about five degrees above normal, in the mid 60s across the interior, and around 70 at the coast. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... Model trends continue to point toward plenty of clouds and a good chance of showers on Thursday as a dissipating MCS arrives from the Great Lakes. While the upper trough pivots south and east across the northeast, thermal forcing is weak and wander if this is more of a convective feedback issue in the lower resolution models. However, the NAM 3km and HRRR does point toward decent coverage of showers Thursday afternoon. Plan to cap rain chances at 50 percent at this time due to the uncertainty mentioned. Strong high pressure builds in from the north Thursday night with any lingering showers pushing south in the evening, NE winds will gradually strengthen on Thursday with some gusts developing near the coast in the evening up to 20 mph. Highs have been dropped several degrees for Thursday due to the increase in cloud cover and rain chances. Readings are forecast to top out in the lower to mid 70s, but could vary somewhat depending on the shower coverage. Cooler air continues to filter in from the north Thursday night with the building high, with lows in the lower 50s well inland, to near 60 in NYC. There is a moderate rip current risk for Thursday. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Dry air filters in on Friday following the cold frontal passage as surface high pressure pushes down from the north. There will be plenty of subsidence resulting in a mostly sunny day. North easterly winds around the high will keep temperatures cool, with highs topping out in the upper 60s to around 70. Clouds will increase Friday night as moisture advects in ahead of a warm front. The best chance at seeing scattered showers will be ahead of a weakening cold front that is forecast to push through Saturday night. The front may dissipate before reaching the area as it encounters an unfavorable environment with a strong ridge in the western Atlantic. High pressure will then build into the region with high amplitude ridging across the central and eastern US into early next week. The remainder of the long term should be mainly dry with warming temperatures to above seasonable levels. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... A cold front approaches tonight, moving across the region overnight into early Thursday and farther south of the area through the rest of the TAF period. VFR conditions expected tonight with increasing mid and high level clouds as showers and thunderstorms move well southwest of the terminals. Clouds lower late tonight with eventually showers moving into the local area late tonight into Thursday. MVFR chances increase Thursday, especially in the afternoon. Localized IFR will be a possibility as well. Winds have decreased to 5-10 kt mainly out of the S-SW. Winds become more westerly late tonight and more northerly by early Thursday. Winds stay NE Thursday into Thursday night and increase to around 10 kts. Gusts to 20-25 kt will be possible Thursday into Thursday night. ...NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http:/ KJFK TAF Comments: Amendments possible for MVFR timing. Gusts 20-25 kt possible in the afternoon into evening Thursday. KLGA TAF Comments: Amendments possible for MVFR timing. Gusts 20-25 kt possible in the afternoon into evening Thursday. KEWR TAF Comments: Amendments possible for MVFR timing. Gusts 20-25 kt possible in the afternoon into evening Thursday. KTEB TAF Comments: Amendments possible for MVFR timing. Gusts up to around 20 kt possible in the afternoon into evening Thursday. KHPN TAF Comments: Amendments possible for MVFR timing. Gusts up to around 20 kt possible in the afternoon into evening Thursday. KISP TAF Comments: Amendments possible for MVFR timing. Gusts 20-25 kt possible in the afternoon into evening Thursday. .OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY... .Thu night...Chance of showers early with MVFR, localized IFR possible. Improving conditions late with VFR returning. .Fri...VFR. .Sat...Chance of mainly afternoon/evening showers and possibly a tstm, with MVFR possible at times. .Sun-Mon...VFR. && .MARINE... Marginal SCA on the oceans this evening due to a moderate SW flow ahead of an approaching cold front. The gradient will relax through the night as the cold front approaches and passes through the waters Thursday morning. Strong high pressure building to the north Thursday night will tighten up a the pressure gradient with E-NE gradient winds at 15 to 20 kt with gust up to 25 kt on the ocean waters. Winds elsewhere look to be just below SCA criteria. Winds and seas will remain at SCA levels into Friday afternoon before subsiding Friday night. However, ocean seas will be slow to subside and may be stay up into Saturday afternoon. Sub SCA conditions are expected late Saturday and Sunday across all the forecast waters. && .HYDROLOGY... No significant hydrologic impacts expected through the weekend. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO35 (162.55 MHz) remains off the air. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until midnight EDT tonight for ANZ350-353- 355. && $$ SYNOPSIS...CB/DW NEAR TERM...DS/DW SHORT TERM...DW LONG TERM...CB AVIATION...JM MARINE...CB/DW HYDROLOGY...CB/DW EQUIPMENT...