Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/14/24


Area Forecast Discussion
National Weather Service Binghamton NY
1149 PM EDT Sun Oct 13 2024 .SYNOPSIS... Showery weather will continue through Wednesday, especially across Central New York. Dry weather will return Thursday and will likely last through the weekend. Temperatures will also be well below normal through Wednesday, before temperatures warm up again late in the week. && .NEAR TERM /THROUGH MONDAY NIGHT/... 950 PM Update: Increased PoPs from Binghamton north and west Monday morning and into the early afternoon hours as a band of steady precipitation is likely to form in this location on the NW side of a developing low pressure system. The CAMs have come into better agreement on this area seeing steadier precipitation, so increased QPF amounts as well, and even went above the latest NBM for PoPs. There still remains the possibility for wet snow flakes to mix in over the higher elevations of the northern Susquehanna region, Catskills and S. Tug Hill plateau on Monday; not expecting any accumulation though with surface temperatures and wet bulb temps above freezing. 715 PM update: Scattered to numerous showers continue to stream over the area this evening, with isolated thunderstorms still possible from the Twin Tiers south across NE PA into the overnight hours. There are also areas of fog out there which may continue overnight. Temperatures were adjusted down 1-3 degrees with this update. The main uncertainty in the near term forecast is how much wrap around rain will be present on Monday, and exactly how long will it linger. There remain differences in the CAMs such as the 18z HRRR, 22z RAP and 18z 3km NAM. For now, took a blended approach with this guidance for the official forecast grids. It will become colder aloft after the surface low and 850mb low move northeast of our CWA (near Albany) by late Monday morning or midday. As 850mb temperatures fall to around -3C in the afternoon it is not out of the question that some wet snow flakes begin mixing in over the higher elevations as the precipitation shield slowly lifts northeast and exits. Temperatures will only be in the upper 30s to mid-40s early Monday afternoon over Central NY...with 40s to around 50 for NE PA. 300 PM Update: A surface low is moving through northern PA this afternoon with a sharp temperature gradient from upper 60s in Hazleton PA to low 50s in Scranton PA. Thunderstorms have developed along this warm front and will move through NEPA and parts of the Southern Tier through the evening. Most of these storms are north of the warm front so the cells should stay elevated with some small hail in the stronger storms. The surface low moves into the Gulf of Maine overnight with cold NW flow behind the front as a long wave trough digs in. Water vapor imagery shows a robust shortwave in Northern Wisconsin this afternoon and that should swing around the base of the trough late tonight into tomorrow morning and provide lift for continued rain showers across the region so chances of precipitation were kept higher through the day tomorrow. Across the Finger Lakes region, chances of precipitation were raised as 850 mb temperatures fall to near -5C tomorrow with surface temperatures of Lake Ontario up around 17C so there will be plenty of lake induced CAPE to generate widespread rain showers. Thunder was left out of the weather grids for now across CNY and the Finger Lakes but there is small potential as cold air continues to advect in with higher amounts of lake induced CAPE develop late Monday into Monday night. Forecast soundings across CNY showed that the freezing level will be getting low for this time of the year, falling down to near 2000 feet above sea level. Forecast soundings are saturated so the wet bulb will stay above freezing for the lower elevations but a few wet snow flakes may mix in with the precipitation at elevations above 1000 feet for CNY Monday night. Frost Monday night may be tough to get as we will have wind and clouds as well as precipitation for much of the region. Higher elevations of the Catskills and Poconos above 2000 feet may get below freezing thanks to the cold air advection but radiational cooling is unlikely for lower elevations. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... 310 PM Update... An upper-level trough will sweep through the region during the mid- week period, putting CNY and NEPA under cool, northwest flow. Wraparound moisture and multiple passing shortwaves will enhance lake effect precipitation. Near surface conditions will be warm enough for just rain showers during daytime hours. Surface temperatures will climb into the 40s and low 50s. Strong low-level flow will be able to mix to the surface and result in blustery conditions across the region. Conditions will feel much cooler than what the thermometer will ready. Also, peak gusts of 20 to 25 mph will be possible. Cooler air will continue to filter in from the north. 850mb temperatures will fall to -4 to -6C. These cooler conditions will be favorable for rain/snow mix or even just snow, mainly in the higher elevations in CNY. A trace to a couple tenths of accumulation will be possible. Temperatures will fall into the upper 20s and 30s overnight. Patchy frost may be possible in far southern NEPA if skies can stay clear long enough for temperatures to quickly fall. There is also some uncertainty if winds will be light enough for frost to develop. Wednesday will start out chilly, at least it will feel that way as breezy winds will result in wind chills in the 20s and 30s as many are heading out the door for school and work. Unfortunately, the cool, northwest flow will remain in place despite a ridge beginning to build into the region. As a result, temperatures only warm up into the 40s and potentially low 50s for some in NEPA. Lake effect precipitation will also continue with any snow transitioning back to rain by the afternoon hours. High pressure builds into the region Wednesday night, bringing drier air into the region. With the trough moving out of the region, this drier air will replace the wrap-around moisture that will be present throughout the first half of the week. With limited moisture, precipitation is expected to come to an end late Wednesday tonight. Despite the cooler air starting to retreat to the northeast, good radiational cooling will take place as skies begin to clear out, leading to lows in the upper 20s to mid 30s. Since winds will be calm, conditions will be favorable for frost. For winds this period, the latest NBM guidance was lower than previous runs and forecasts, at least through Wednesday daytime. With a sharp pressure gradient and likely deep mixing, the previous forecast was blended in with the latest NBM guidance. To better collaborate with neighboring offices, NBM 10th percentile was also used to increase the gusts. For Wednesday night, just NBM guidance was used. && .LONG TERM /THURSDAY THROUGH SUNDAY/... 310 PM Update... With a ridge of high pressure in control throughout the long term period, conditions will be mostly dry and temperatures trend warmer. Canadian model guidance does continue to have the lake effect precipitation lasting into Thursday as well. While that may have to be something to consider in future updates, this update continues to keep Thursday dry as there will be quite a bit of dry air to overcome for this to happen. While Sunday is looking mainly dry as well, the next system will be just outside of our region. If timing were to trend quicker, this would then be the next chance for showers. Temperatures return to the 50s and 60s during this period. Widepsread 60s are expected during the weekend. Overnight lows won`t see as much of a warm up but 40s will be possible by Saturday night after a week of lows in the 30s or colder. Clear skies may allow temps to fall cooler than forecasted during the overnight hours. && .AVIATION /04Z MONDAY THROUGH FRIDAY/... Unsettled conditions and varying restrictions, both to ceilings and visibility, will be in place through much of the TAF period as an area of low pressure and trailing cold front will be working its way through the area this evening. This low will be followed by another low pressure system currently located over the Upper Midwest which is expected to rotate into the region early tomorrow morning. Scattered showers are expected to be around most terminals this evening before there is a little bit of a lull before the next disturbance approaches with an uptick in showers around 08-10Z. There can be a spotty thunderstorm this evening near and south of the low track, and a TEMPO is in for BGM with recent lightning strikes recorded nearby. AVP will be monitored closely with storms currently over central PA. If they hold together, thunder will be possible between 01-03Z. Ceilings will vary across the terminals with MVFR and worse conditions. AVP will be VFR initially before MVFR conditions are expected to develop at times overnight. Winds will be increasing tomorrow morning as they shift out of the northwest with gusts of 20-25 knots possible. Improving ceilings are expected tomorrow afternoon and into the evening. .Outlook... Monday night through Wednesday...Scattered showers and associated occasional restrictions at Central NY terminals. Mainly VFR at KAVP. Thursday into Friday...Mainly VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...BJG NEAR TERM...AJG/MJM SHORT TERM...BTL/ES LONG TERM...BTL AVIATION...AJG/DK
Area Forecast Discussion
National Weather Service Boston/Norton MA
1008 PM EDT Sun Oct 13 2024 .SYNOPSIS... Low pressure tracking across the region tonight will bring more showers into Monday morning as a cold front sweeps through, then trending drier and breezy for Monday afternoon. Though dry weather will prevail, blustery with below normal temperatures are expected Tuesday and Wednesday, with a gradual warming trend beginning Thursday into next weekend. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 10 PM update... One cluster of showers and isolated thunder is impacting the Cape and Islands and will be moving offshore during the next few hours. Meanwhile another area of convection is lifting NE from eastern MA assocd with a weak shortwave. HRRR and NAM3k have a pretty good handle on this and bring a round of showers and isolated thunder into western and northern MA and NW CT around and after midnight. Then will have to watch for yet another area of showers and isolated thunder possibly developing across RI and eastern MA late tonight into Mon morning as the amplifying upper trough approaches from the west. All the guidance is indicating area of elevated instability moving east across the region overnight. Overnight lows stay milder compared to last night, with low 40s in NW MA to low-mid 50s along the coastal plain. Even milder Cape/Islands which will remain south of the warm front with temps upper 50s and lower 60s. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... Upper-level shortwave and surface cold front move through the region Monday morning. With dry air and PWATS tumbling to 0.5 inches, the frontal passing will clear out any remaining rain showers. Winds behind the front become gusty from the WNW again at 25 to 30mph. High temperatures will again be cooler in NW MA in the low 50s, with mid to upper 60s in SE MA. Clouds begin to clear out tomorrow morning, with mostly sunny skies by the afternoon. Winds Monday night continue to gust from the NW at 15 to 20 mph as the pressure gradient remains tight due to the departing low to over northern New England. The gusty winds will keep lows from bottoming out in the upper 20s, instead staying in the low to mid-30s. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Much of this portion of the forecast is expected to feature a mid level longwave trough whose axis moves from the Great Lakes Tuesday into the Appalachians Wednesday, then moves offshore Thursday. Beyond then, it is looking like a mid level ridge builds over southern New England into next weekend. At the surface, a large high pressure should move from central Canada Tuesday, into the central USA Wednesday, before reaching the OH valley and central Appalachians Thursday. This high pressure should then linger nearby Friday into next weekend. Overall, looking like a prolonged dry stretch for most of southern New England. The exception to that looks to be mid week, when the cold advection across our region will be strongest. The relative difference between air and water temperatures, which were still around 60 degrees F, may be enough to generate some showers over the coastal waters. Anticipating below normal temperatures just about all this week. Thinking temperatures trend closer to normal Friday, then above normal into next weekend. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... Forecast Confidence Levels: Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Tonight...Moderate confidence. Mainly MVFR to start then IFR developing, with pockets of LIFR for interior terminals. The Cape and Islands likely stay VFR/MVFR overnight. Showers begin to scatter out overnight. Winds start turning NNW overnight at 5-10 knots Monday...Moderate confidence. Starting IFR, but a cold front moving west to east should quickly clear things up to VFR between 14-18z. Winds turn WNW behind the front and gust up to 25 knots. Monday Night...High Confidence VFR with WNW decreasing winds. KBOS TAF...Moderate confidence Brief break in the showers this evening. CIGS gradually drop to IFR before midnight. Low chance for LIFR conditions overnight between 06z-12z. A cold front will begin to clear things out after 12z, with VFR by 18z. Winds turn WNW with the cold front and gust up to 25 knots. KBDL TAF...Moderate confidence MVFR CIGS drop to IFR after 05z. A cold front will quickly clear things up to VFR Monday morning. Outlook /Tuesday through Friday/... Tuesday through Wednesday: VFR. Breezy. Wednesday Night through Friday: VFR. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tonight through Monday Night: A strong LLJ will bring SSW gusts of 20-30 knots for much of the coastal waters tonight. Seas become rough starting tonight, rising to 6-8 feet across the southern waters and 4-6 feet in the northern waters. Scattered rain showers and possibly an isolated thunderstorm across much of the coastal waters tonight. A strong cold front crosses the waters late Monday afternoon, turning winds to the WNW, with continued gusts of 20-30 knots. Winds begin to subside to 10-20 knots Monday night, with seas dropping to 3-5 feet. Outlook /Tuesday through Friday/... Tuesday: Winds less than 25 kt. Seas up to 5 ft. Tuesday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Slight chance of rain showers. Wednesday: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain showers. Wednesday Night through Thursday: Winds less than 25 kt. Slight chance of rain showers. Thursday Night through Friday: Winds less than 25 kt. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory from 2 AM Monday to 2 AM EDT Tuesday for ANZ232>234. Small Craft Advisory until 5 AM EDT Tuesday for ANZ235-237. Small Craft Advisory from 2 AM Monday to 8 AM EDT Tuesday for ANZ250. Small Craft Advisory until 8 AM EDT Tuesday for ANZ254>256. && $$ SYNOPSIS...Belk/KP NEAR TERM...KJC/KP SHORT TERM...KP LONG TERM...Belk AVIATION...Belk/KP MARINE...Belk/KP
Area Forecast Discussion
National Weather Service Cheyenne WY
557 PM MDT Sun Oct 13 2024 .KEY MESSAGES... - Frost and freezing temperatures are expected for many areas tonight. Frost advisories are in effect for parts of southeast Wyoming and western Nebraska. - Dry weather is expected through Wednesday - Chances for a few light showers and light mountain snow remain possible late-week into this weekend. && .SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 232 PM MDT Sun Oct 13 2024 Upper level ridging remains in place across the region this afternoon, and thus the current weather pretty much reflects what it has been for the past month. There are a few cumulus clouds drifting off the Snowy and Sierra Madre ranges, and there is some wildfire smoke evident streaming across from roughly Douglas to Scottsbluff. The HRRR smoke model suggests that some near-surface smoke may persist in small quantities into this evening. Tonight, the upper level ridging pattern is expected to remain in place with a very slow moving upper level low over Nevada drifting ever so slowly to the southeast, providing us without impacts from it. The main story tonight will be potential for some frost and freezing or near-freezing temperatures supported by mostly clear skies and generally light winds. The highest probabilities for frost are expected in far southeast Wyoming into western Nebraska, closest to the high pressure system over the upper midwest. For zones that have not yet seen a hard freeze, some frost advisories were issued. I contemplated issuing a freeze warning for Goshen county, but NBM probabilities for temperatures actually reaching freezing are only up to ~50% and with spatial coverage <50%. We will continue to monitor in case an upgrade may be needed, but at this time it`s looking like a widespread frost with perhaps localized freezing conditions possible. On Monday, expect more sunny and dry conditions with ridging overhead. Winds start to become more north to northwesterly as colder air associated with the broad high pressure to the east retreats a bit. Expect a nice recovery in temperatures with highs in the 70s east of the Front Range and cooler west. There is a bit of signal for some blustery conditions at 700 hPa, so winds have been nudged a bit above NBM for the afternoon, though confidence isn`t high that we will see gusts much over 25 mph except locally. Fire weather is expected to be elevated as a result of low RH falling to 15-20% for several places, though as a whole, wind gusts are expected to remain below 25 mph. Potential for some more frost Monday night as some cooler air filters back in from the east, but winds perhaps slightly more blustery may keep temperatures a degree or two warmer compared to tonight. Nevertheless, some frost and freezing temperatures will again be possible. Tuesday into Tuesday night, the closed low to our southwest will remain there with ridging over our region. Thus, another dry and sunny day, albeit a bit cooler with colder air moving in from the east. There is a bit better of a signal for some gusty winds along the temperature gradient across western Nebraska and southeast Wyoming, though with slightly higher humidity around 20-25%. Thus, another day with perhaps some elevated fire weather conditions, but red flag conditions are not expected at this time. The ridging pattern starts to signal its end as the upper level low becomes absorbed within a broader trough moving into the western CONUS Tuesday night. Quiet and slightly warmer weather is expected Tuesday night. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... Issued at 232 PM MDT Sun Oct 13 2024 After a very prolonged period of uneventful weather regarding precipitation, we have a highly anticipated weather pattern shift that should bring some widespread measurable precipitation to the region by the end of this upcoming week. Before we get there, there will be a weak disturbance that ejects out of the Four Corners region Wednesday. This lingering upper level low (ULL) is not anticipated to have much energy associated with it, so the anticipated weather forecast would just be some diurnal rain showers and sprinkles in the higher terrain along and west of the I-25 corridor. Above average temperatures will accompany this weak weather disturbance as we remain beneath the amplified upper level ridging pattern, although the ridge axis will be propagating toward the Central Plains and Great Lakes region by late Wednesday. Daytime highs in the 70s to low 80s can be expected, with cooler temperatures in the mountain zones. With the persistent drought conditions being present, there will also be some breezy winds and low RH values east of the Laramie Range. This could create some fire weather concerns as we have very dry conditions on the flashy 1 hour fuels. Wednesday night and Thursday will be the onset of the weather pattern shift. Surface pressure tendencies will fall due to lee surface trof perturbations east of the Laramie Range and Front Range. Surface cyclogenesis in the Dakotas will cause gusty winds in our wind prone areas. Have bumped up the wind gusts for the gap and wind prone areas of southeast WY to reflect this. Should model consistency prove true, we will be close to high wind headlines for the I-80/I-25 corridors that are favored during wind events. There will be a surface cold front that is anticipated to slowly propagate to the east on Thursday, bringing cooler temperatures to our north and western forecast zones. Further east, WAA will cause daytime high in the NE Panhandle to surge into the upper 70s to middle 80s where the cold front won`t arrive until much later. This cool front will not be accompanied by much atmospheric energy, so the chances of precipitation are low for rain showers. The main weather story is the timing of a secondary, and more potent cold front on Friday. Model guidance continues to signal much colder temperatures for daytime highs on Friday behind the cold front, but there is still a high amount of spread for deterministic solutions regarding exact timing and location of precipitation. The ECMWF, UKMET, GFS, Canadian, and ICON deterministic models for the extended model guidance show a longwave trough ejecting out of the Pacific Northwest toward the Central Rockies. From there, a myriad of localized deterministic differences emerge: heavy mountain snowfall for the Central/South Rockies to little snowfall for our mountain zones, and light rainfall for lower elevations. The consensus is that the Upper Level Low (ULL) will become sheared off from the main longwave trough and continue to "wobble" across the Four Corners area from Friday through the weekend, bringing the highest precipitation to areas further south and west of our cwa. Ensemble members have a better agreement on the colder temperatures sticking around for a short period of 36-48 hours, before we transition back to warmer daytime highs to round out the weekend. There still remains a lot of details to unpack with the extended model guidance, but overall expect much cooler temperatures and measurable precipitation to return to the area briefly by the end of the upcoming week. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 535 PM MDT Sun Oct 13 2024 A weak upper level ridge axis will remain over the Rocky Mountain Region and Adjacent eastern high plains through Monday. Relatively light winds and mostly clear skies will prevail. HAZARDS/WEATHER TRENDS: VFR conditions will continue with minimal Aviation concerns. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Frost Advisory from 2 AM to 8 AM MDT Monday for WYZ108-119. NE...Frost Advisory from 2 AM to 8 AM MDT Monday for NEZ019-020-054. && $$ SHORT TERM...JDS LONG TERM...BW AVIATION...TJT
Area Forecast Discussion
National Weather Service Grand Junction CO
548 PM MDT Sun Oct 13 2024 .KEY MESSAGES... - One last day of near record high temperatures today. - A system works into the region late today bringing chances for showers off and on through Wednesday. - A more significant system moves into the region late in the week through the coming weekend and is expected to bring valley rain and mountain snow as well much cooler temperatures more reminiscent of Fall. && .SHORT TERM /THROUGH MONDAY NIGHT/... Issued at 234 PM MDT Sun Oct 13 2024 Scattered showers have developed over the southern mountains with isolated activity across portions of the central mountains and as far north as the Bookcliffs. This is in response to diffluent flow ahead of a weak low pressure system dropping through the Great Basin that is pulling in some weak moisture advection. So far, instability remains limited so no lightning strikes are evident at this time with the HRRR indicating CAPE around 50 J/kg or less. Some showers look to increase across east-central Utah to west-central Colorado this evening as this low drops further south into southwest Utah by Monday morning, but not expecting much in the way of precipitation as chance of wetting rain remains low with continued dry low levels. This low does not have much dynamic support as it becomes cut off from the main flow and trapped underneath the high pressure ridge that will expand across the Intermountain West and Northern Rockies, leaving this cut off low spinning over southern Utah and near the Four Corners on Monday. We can expect weak shower activity across the southern and central mountains on Monday afternoon with embedded thunderstorms still possible but CAPE still remains low. Clouds today seem to be putting a damper on our expected high temperatures but we still remain about 10 to 15 degrees above normal today and Monday with near record highs possible in a few areas. Overnight lows still also remain about 10 degrees above normal for mid October even though the overnight and early morning seem to be providing some refreshing cool relief from the afternoon heat. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Issued at 234 PM MDT Sun Oct 13 2024 Models continue to show the weakening closed low over the Four Corners region Tuesday, before becoming an open wave and ejecting to the northeast on Wednesday. As far as our sensible weather is concerned, Tuesday will see gradually increasing cloud cover and a few widely scattered showers over the higher terrain during the afternoon and evening. Temperatures remain similar to what we`ve seen the last several weeks. However, as the wave begins to eject to the northeast on Wednesday, look for more widespread cloud cover, increased shower activity over the Divide mountains, and temperatures a few degrees cooler than previous days. Still 5-10 degrees above normal, though. As the Western Slope deals with a modest cooldown and mountain showers on Wednesday, the next Pacific trough will be swinging into the Pacific Northwest. It is this trough that looks to finally bring a pattern shift to the Intermountain West late in the week, with significantly cooler temperatures and potentially much wetter conditions as well. Above normal moisture is forecast to hang around over eastern Utah and western Colorado through the coming weekend. On Thursday, a potent cold front will push through, acting on that lingering moisture to bring widespread precipitation... mainly rain, as antecedent conditions are so warm, but some mountain snow at the highest elevations will work in. Thanks to the front, and the widespread showers and clouds, temperatures will drop yet again, running now in the 4-8 degrees above normal range. Now, in previous runs, there had been quite a bit of uncertainty regarding the forecast for Friday into the weekend. There had been two rather equally supported camps, one for this trough slowing down and developing a cutoff low somewhere over the southern Great Basin, and the other maintaining a progressive open wave. With this morning`s 12z runs, however, models have actually come into agreement on one solution. The outlier guidance, the deterministic and ensemble ECMWF, have come around to developing a cutoff low somewhere over the southern Great Basin, putting them in alignment with the GFS/GEFS and the Canadian model suite. This then also favors a longer residence time of strong dynamic forcing to work on the resident moisture, bringing a prolonged precipitation event and, potentially, our first winter highlights of the season. Unless something truly drastic happens over the coming days, confidence is high that we`ll see mountain snow and valley rain Friday into the weekend, with current forecast snow levels dropping as low as 7K feet. The questions of exactly when, where, and how much will have to wait a few more runs to be ironed out, as while models have come to agree on one solution, they do not agree on most of the details. Just a few hundred miles of difference in the placement of the center of the low can have drastic impacts on precipitation amounts, cloud cover, and temperatures across the region, and guidance is still all over the place with that factor alone. As far as temperatures are concerned, there is a pretty strong signal that we`ll see a substantial cooldown with this system. Ensemble guidance, deterministic guidance, and blended guidance all drop temperatures near to a few degrees below normal for Friday into the weekend. That doesn`t sound that impressive until you remember that by mid-October, the desert valleys should be seeing highs in the low to mid 60s, and mountain towns should be seeing 40s to low 50s for highs. That`s quite a departure from the temperatures we`ve seen the last several weeks, and will feel like a bit of a shock at first. But it does seem that fall is finally making a return to the Western Slope. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 541 PM MDT Sun Oct 13 2024 More mid and high-level clouds are forecast through the TAF period. Virga in the vicinity of TAF sites may produce periodic wind gusts up to 25 mph. Precipitation chances increase tomorrow afternoon over the southern mountains with a light shower or two possible at TEX. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...MDA LONG TERM...BGB AVIATION...TGJT
Area Forecast Discussion
National Weather Service North Platte NE
612 PM CDT Sun Oct 13 2024 .KEY MESSAGES... - Widespread frost and freeze event appearing likely tonight and again tomorrow night. Potential hard freeze for most of the Sandhills. - Fire weather concerns return Wednesday and Thursday as temperatures rebound, humidity lowers, and winds really strengthen. - Fall-like temperatures come back at the week`s end, along with precipitation chances. && .SYNOPSIS... Issued at 411 PM CDT Sun Oct 13 2024 A large upper ridge is centered over the Intermountain West, while a trough digs across the Great Lakes, resulting in northwest flow aloft for Nebraska. Toward the surface, a broad high pressure extends across the central and northern Great Plains. Mostly clear skies and a light northerly breeze complemented seasonable temperatures in the upper 50s to 60s in the Sandhills today. && .SHORT TERM /THROUGH MONDAY NIGHT/... Issued at 411 PM CDT Sun Oct 13 2024 This evening and tonight... The center of the surface high drifts southward and will sit directly over the Sandhills after 06z. A band of mid/high level clouds currently (as of 20z) over the Dakotas will continue to spread south, which will probably affect far north central Neb overnight. Other than that, mostly clear conditions will continue, along with light to calm low level winds. All in all, the setup appears good for full boundary layer decoupling. RAP forecast soundings indicate a large inversion and a very dry column throughout. Trended the min temp forecast toward the 25%ile NBM, which falls in line with most MOS guidance, and nudged the Platte River Valley even lower to account for cold air drainage. Would not be surprised if some spots in the Sandhills or river valleys will be even colder than represented. With forecast values now ranging from the mid 20s in parts of the Sandhills to right near freezing in southwest Nebraska, updated the Frost Advisory and Freeze Watch over to a Freeze Warning for the entire CWA. Confidence in a hard freeze is relatively lower for areas south of I-80, but decided upon Warning for collaboration purposes with adjacent WFOs. Tomorrow and tomorrow night... The upper ridge makes little eastward progress, but the surface high continues on its trek toward the Mississippi Valley. This pattern places western Nebraska squarely in southerly return flow in the low levels. Later in the day, a weak surface low then straddles the NE/SD border, which drags a trough (warm front?) across the panhandle. Fair skies, somewhat deeper mixing, and a period of westerly downslope flow will help push temperatures back into the 70s for the western half of the CWA. The warm air advection scheme kicks into high gear with 24 hr temp changes at H85 approach 6-8C. Trended toward the warmer MAV for max temps, partly due to the persistent dry air. Forecast values range from mid 60s north central to mid 70s panhandle. Nighttime lows are rather tricky this go around as an H85 thermal ridge gives way to east/northeast low level backing flow. The sky will likely be mostly clear again, but surface winds may stay a bit higher around 10-15 mph. Some solutions suggest "milder" lows compared to tonight, while some solutions keep with the hard freeze criteria. For now, split the difference, which still lines up between the 25th and 50th percentiles of the NBM envelope, generally upper 20s to lower 30s. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Issued at 411 PM CDT Sun Oct 13 2024 A secondary surface high backs into the Upper Midwest, which continues the easterly low level flow for Nebraska, and the upper trough digs deeper into the Eastern US for Tuesday. Guidance is in good agreement regarding a strong cold air advection scheme with H85 temps around 10C cooler compared to Monday. Highs will likely be stuck in the 50s for most of the CWA. Despite the east winds, no additional moisture is advected in, as shown by falling dew points throughout the day. The pattern changes briefly for Wednesday and Thursday as the upper ridge over the Rockies turns progressive and kicks across the Plains. The surface high gets confined to the Ohio Valley while a deep low over the northern High Plains pulls a warm front through Nebraska, then a dryline/trough, and finally a strong cold front. Temperatures rebound to well above normal levels (lower 80s) by Thursday, as southerly winds really strengthen ahead of the cool front. Gusts above 40mph are appearing more likely Wed. afternoon. Humidity levels are marginally supportive of critical fire weather as of now, but the wind will be more than enough to support rapid fire spread during this timeframe. Trends will be monitored for potential fire weather headlines. The upper ridge promptly breaks down over the Plains at the end of the week as a lee side surface low spins up near the CO/KS/NE border and the front slows. This setup favors cooler conditions once again, but also a decent chance of moisture. Discrepancies remain in the longer range solutions regarding timing and coverage of precip, but periodic showers Friday into Saturday seem to be a decent bet. Capped PoP to 50% / "chance" until details become clearer. Potential exists for some locations to receive the first wetting rain in several weeks. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 609 PM CDT Sun Oct 13 2024 Strong sfc high pressure across srn Canada and the nrn and cntl Plains will build south tonight and then east into the Midwest Monday. Very dry air will remain across wrn/ncntl Nebraska during this time and VFR is likely across the region. && .LBF WATCHES/WARNINGS/ADVISORIES... Freeze Warning from 1 AM CDT /midnight MDT/ to 9 AM CDT /8 AM MDT/ Monday for NEZ004>010-022>029-035>038-056>059-069>071-094. && $$ SYNOPSIS...Snively SHORT TERM...Snively LONG TERM...Snively AVIATION...CDC
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
924 PM EDT Sun Oct 13 2024 .SYNOPSIS... As low pressure passes to our northeast, a cold front moves through tonight into early Monday morning. High pressure will gradually build eastward from the Midwest through mid week. This area of high pressure settles over the Eastern Seaboard by Thursday into next weekend. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... EVENING UPDATE... Some clouds and isolated showers have developed around western Maryland and the eastern West Virginia panhandle this evening as the cold front approaches. A few flashes of lightning have also been noted with these cells. They have also continued further east than earlier CAMs suggested, though the latest HRRR now caps their eastward progression around the Blue Ridge. SPC continues to highlight a Marginal risk for severe thunderstorms in this area. Based on more recent CAMS, expect isolated showers with possible thunder from now until shortly after midnight for areas along and west of the Blue Ridge. Some weakening showers could make it further east, but would be less likely to have lightning and should quickly dissipate. PREVIOUS DISCUSSION FOLLOWS... The latest surface observations show the backdoor front has stayed north of the Mason-Dixon Line. An expanding warm sector is noted over the Mid-Atlantic, accompanied by increasing southerly warm advection. With only spotty clouds and continued surface heating, much of the area has seen temperatures rocket well into the 70s to low 80s. In particular, a spotty area of mid 80s can be expected across the Allegheny mountain valleys extending from Grant County up into western Allegany County. Southerly winds will continue to be breezy at times, pushing into the 25 to 30 mph range at times. Looking farther upstream, the pattern changing cold front looms back over central Ohio. Lagging behind is the parent upper trough which is currently spinning near the Upper Great Lakes. Given the lack of alignment of the surface and features aloft, the focus for convection is somewhat nebulous. The Storm Prediction Center paints a Marginal risk for severe thunderstorms from I-81 westward. This is actually an eastward expansion from previous outlooks. 12Z HREF ensemble paintball plots show some enhanced reflectivity racing from the Alleghenies toward I-81 during the early/mid evening hours. Locally damaging wind gusts would be the primary threat given the higher LCLs and increasing downdraft CAPE values. Any convective threat decays for those farther east. The cold front currently over the Ohio Valley is expected to cross the Allegheny Front late this evening before reaching the Chesapeake Bay by the middle of the overnight hours. This brings an abrupt wind shift to westerly which will become increasingly gusty in time. Low temperatures will be coolest west of I-81 with mainly 40s expected. Farther east, 50s to low 60s are more likely. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... The core of upper forcing with the trough pushes across the Mid-Atlantic region early Monday. This particular surge allows for the larger push in dew point falls as cooler/drier modified Canadian air works its way in from the northwest. Favorable upslope trajectories will carry a threat of rain showers along the Alleghenies. This is accompanied by mostly cloudy skies, gusty winds, and temperatures confined to the 40s. For downstream locations, a considerable cool down is also evident as high temperatures fall into the upper 50s to 60s (warmest south of I-66). This comes with a mixed bag of sun and clouds along with northwesterly wind gusts around 25 to 35 mph, locally up to 40 mph across the Allegheny mountain peaks. Winds begin to decrease in strength after nightfall with the loss of deep vertical mixing. Enhanced cloud cover overnight should limit the true potential of nocturnal cooling. Low temperatures drop into the upper 30s to mid 40s, with widespread low/mid 30s over the mountains. There should be enough wind to thwart off a widespread frost although the near freezing temperatures could cause a freeze in spots across the Alleghenies. A reinforcing shortwave continues to trend deeper for Tuesday which has led to an uptick in precipitation chances. Not only will this bring a reinforcing shot of cold air, it also invigorates another round of shower activity along the Allegheny Front. Given the cooling temperatures, some of this will feature a mixture of rain and snow over the Allegheny ridges. The current forecast does bring a couple tenths of an inch of snow over such locations. It remains to be seen if this will actually accumulate given marginal surface temperatures. Elsewhere, scattered rain showers are advertised given the ample ascent underneath this strong trough. These likely weaken after dark as heating is lost. Tuesday`s high temperatures hold steady in the mid/upper 50s, while the higher elevations can expect 40s to low 50s. With high pressure still back over the Mississippi Valley, it is not certain winds drop off enough to bring a widespread frost to those from U.S. 15 westward. The current forecast does drop lows into the mid 30s over much of that area, with low 30s over the mountains and I-81 corridor. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... The main upper trough axis will pass overhead Wednesday morning, before moving off to our south and east later Wednesday afternoon into Wednesday night. At the surface, a broad area of high pressure will build eastward from the center of the country toward the Ohio Valley by Wednesday night. Northwesterly flow ahead of the approaching high will maintain below normal temperatures across the area on Wednesday. Upslope snow showers will continue along the Allegheny Front during the morning, before winding down during the afternoon hours. Further east, a mix of clouds and sun is expected. High temperatures will range from the 30s and lower 40s in the mountains, to the 50s further east. High pressure will continue to build eastward Wednesday night into Thursday, before becoming centered overhead Thursday night. The pressure gradient should weaken enough for many locations to decouple Wednesday night. Radiational cooling will allow temperatures to plummet into the 30s for most, with lower 40s in the urban centers. Frost and freeze headlines will likely be needed for much of the area. Sunny skies and light northerly winds are expected during the day Thursday. High temperatures will be in the upper 50s and lower 60s for most (upper 40s-lower 50s in the mountains). Another night with ideal radiational cooling conditions is expected on Thursday night as the high builds overhead. Low temperatures will be in the 30s for most, and frost/freeze headlines will likely be needed once again. High pressure will remain in the vicinity through Friday and Saturday as upper ridging builds in aloft. This will lead to continued sunny skies, light winds, and a warming trend in temperatures. Highs should be in the 60s on Friday (upper 50s/lower 60s mountains), and then upper 60s to lower 70s on Saturday (low-mid 60s mountains). && .AVIATION /01Z MONDAY THROUGH FRIDAY/... While mainly VFR conditions are anticipated through Tuesday, the big story will be the gusty winds in response to a pronounced pattern change. Ahead of the cold front, expect a breezy southerly wind with gusts up to 20 to 25 knots through early this evening. This front tracks through overnight leading to a shift to westerly winds into the first half of Monday before turning more northwesterly. Gusts up to 25 to 30 knots are expected in this gusty post-frontal environment. Wind fields largely stay out of the west to northwest into Tuesday as well. Afternoon gusts up to 20 knots are possible on Tuesday as a system aloft tracks through. This may also spark scattered showers over the area, although no restrictions are expected at this time. VFR conditions and northwesterly winds are expected on Wednesday. Light northerly winds and continued VFR conditions are expected on Thursday. && .MARINE... Ahead of a strong cold front over the Ohio Valley, a breezy southerly wind has overspread the marine waters. As such, Small Craft Advisories are in place through tonight. This frontal boundary pushes across the waters early Monday morning leading to an abrupt shift to westerly winds. This gusty post-frontal environment will yield widespread gusts of 25 to 30 knots, potentially approaching gale force at times. However, model soundings and high-resolution model output are somewhat at odds at how widespread and frequent such gusts would be. For now, will maintain Small Craft Advisories through the day which will likely be extended into portions of Monday night. Northwesterly wind gusts stay close to the 15 to 20 knot range through Tuesday, slightly toward that higher range later in the day. Small Craft Advisories may be needed over portions of the waters during this period. Northwesterly winds may reach low-end SCA levels on Wednesday. Light northerly winds are expected over the waters on Thursday. && .TIDES/COASTAL FLOODING... Strengthening south winds may result in a surge into Action Stage along sensitive shoreline later today. No coastal flooding is explicitly forecast at this time, although guidance is closest to minor flood stage at Annapolis. The threat ends behind a cold front tonight. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory until 6 PM EDT Monday for ANZ530>543. && $$ SYNOPSIS...BRO/CAS NEAR TERM...BRO/CAS SHORT TERM...BRO LONG TERM...KJP AVIATION...BRO/KJP MARINE...BRO/KJP TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
714 PM CDT Sun Oct 13 2024 .KEY MESSAGES... - Sub-freezing temperatures likely tonight across central Minnesota. Widespread sub-freezing Monday night. - Isolated rain showers continue tomorrow across western Wisconsin. - Warmer temperatures to end the week, along with better chances for rain. && .DISCUSSION... Issued at 208 PM CDT Sun Oct 13 2024 Our coldest air of the season has arrived as sprawling Canadian high pressure spreads into the Upper Midwest. Strong cold advection from blustery northwest winds has kept temperatures in the low to mid 50s this afternoon, and has generated a few isolated showers across western Wisconsin. The winds will weaken after sunset, but speeds are still expected to remain around 5-10 mph overnight. This along with dry RH values should prevent much frost from developing tonight despite the chilly temperatures, but continued cold advection overnight will likely result in temperatures dipping below freezing across west-central Minnesota by early tomorrow morning. Another chilly day is expected Monday as the high pressure becomes centered over the region. Winds will be lighter, but the cold core aloft will be centered over the area so temperatures will again struggle to warm much into the 50s during the afternoon. Isolated light rain showers will again develop across western Wisconsin, and a narrow band of light rain is also possible across southwest Minnesota as a jetstreak moves over the eastern dakotas/western MN. Ideal radiational cooling conditions develop Monday night as winds become calm and skies remain clear under the center of the high pressure. Widespread sub- freezing temperatures are expected everywhere except for the inner core of the Twin Cities metro, and temperatures could potentially drop all the way into the low 20s across western Minnesota. This will be the killing frost that officially ends the growing season area-wide, and draining un-insulated outdoor pipes & irrigation system is a wise precaution as well. Temperatures begin to warm midweek as southerly flow returns on the back side of the departing high pressure, and above-normal temperatures return late in the week as highs once again approach the 70s. Ensembles continue to show a strong signal for accumulating precipitation during the Friday to saturday timeframe, as a trough over the central CONUS develops a frontal boundary that moves through the region. The precipitation will likely be constrained to a band along the front, and the front looks to be in the process of decaying as it reaches the region, so unfortunately a widespread soaking rainfall is beginning to look less likely. Still, ensemble guidance shows high probabilities of rainfall in excess of 0.10" which suggests it will still rain, just expect values to likely remain below half an inch. Temperatures are expected to cool closer to more seasonable values behind this front, with highs in the low to mid 60s over the weekend && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 701 PM CDT Sun Oct 13 2024 Wind gusts will slowly back down over the next couple of hours. They will increase in strength again on Monday, though at speeds much lower than what we saw today. Mid/upper clouds will thicken through the night in west central & southwest MN, while stratocu in eastern MN & western WI scatters out overnight. That mid level cloud cover will persist through much of Monday in western MN, while eastern MN and western WI will see an uptick in stratocu coverage as mixing commences Monday morning. KMSP...The HRRR is showing some potential for some MVFR cigs to be approaching MSP toward the end of the period out of WI, but we have lots of time to see if that ends up happening. /OUTLOOK FOR KMSP/ TUE...VFR. Wind N 5-10kts. WED...VFR. Wind SW 10-15 kts. THU...VFR. Wind S 15-20G25-35kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...Freeze Warning from 1 AM to 9 AM CDT Monday for Benton- Chippewa-Douglas-Kandiyohi-Lac Qui Parle-Meeker-Morrison- Pope-Stearns-Stevens-Swift-Todd-Yellow Medicine. WI...None. && $$ DISCUSSION...ETA AVIATION...MPG
Area Forecast Discussion
National Weather Service Reno NV
220 PM PDT Sun Oct 13 2024 .SYNOPSIS... * Cooler temperatures continue today, before warmer afternoons return on Monday and Tuesday. * A storm system arrives on Wednesday bringing cooler temperatures and shower chances to the area. * Another system comes right behind the previous one on Thursday and Friday, keeping the cooling trend and chances for valley rain and possible mountain snow showers. && .DISCUSSION... The latest RAP analysis of the upper air pattern shows an upper level low over northern NV with the REV CWA just to the west of it being underneath the forward part of a trailing ridge. Current satellite imagery and surface observations report mostly sunny skies along with dry conditions across the CWA. Going forward into this week, forecast guidance shows the low departing eastward and the ridge residing over the CWA through Monday night. By Tuesday, the ridge begins to progress eastward as an upper air trough moves into the Pacific Northwest. As a result of this upper air pattern development, dry conditions are expected to continue through Tuesday for the region. Daytime high temperatures for today look to be in the 60s to middle 70s range with higher elevation areas in the Sierra topping off in the lower to middle 50s. Low temperatures for tonight expect to range between the middle 30s and around the 50 degree mark in the valleys while Sierra Mountain communities see temperatures drop down to between the 30 degree mark and the lower 40s. Temperatures warm up going into the work week with daytime highs in valley areas being in the 70s on Monday and in the lower 70s to lower 80s range on Tuesday. Higher elevation areas in the Sierra will see to see high temperatures on Monday in the middle 50s to lower 60s and upper 50s to lower 60s on Tuesday. Winds look to be generally light to start the week with Tuesday being the breeziest day having afternoon gusts up to 20 mph possible. Fire weather does not look to be much of a concern with these winds though Tuesday`s forecast calls for minimum relative humidity values in the middle to upper teens in some portions. By Tuesday night and going into Wednesday, forecast guidance depicts the CWA taking a southwesterly upper air flow as the aforementioned trough moves into the northwestern CONUS. The axis of this trough looks to pass over the CWA by the late afternoon and evening hours of Wednesday allowing for a northwesterly flow overnight. At the surface, a cold front looks to pass through the area bringing cooler temperatures and precipitation chances back to the region. The best chances (65-75%) look to be in areas closer to the OR border during the morning and afternoon hours of Wednesday with these chances gradually tapering off going southward though there looks to be some chance at least for the entire area throughout the day. Currently, QPF value look to range between a trace and around two- tenths in northern Washoe County. At this time, the precipitation looks to be all of a rain type though the highest elevation areas may see some light snow mixed in (not the best confidence for this yet). Daytime high temperatures on Wednesday drop to between the middle 60s and lower 70s for the valley areas with the Sierra Mountain communities seeing highs in the upper 40s to middle 50s. The higher elevations have low temperatures at or below the freezing point on Wednesday night while the remainder of the CWA has lows in the middle 30s to middle 40s in the forecast. For Thursday and Friday, ensemble guidance continues to show some sign of an inside slider pattern. The uncertainty continues in the latest forecast runs, so will be still be monitoring future runs closely to see how this looks to play out. As a result, temperatures should continue to cool on both days with yet another cold front system passing through the region. The CWA may see some possible enhanced winds that may cause some marine impacts on Thursday. Chances for precipitation are again seen on Thursday though a bit less than those on Wednesday. With cooler temperatures, light snow may be mixed into the rain in some locations once again with NBM guidance showing snow levels down to around 5000 ft during Thursday night. Early snowfall totals look to be under an inch at the mountain summits though lower elevations could possibly also see a trace. Still a lot of uncertainty exists, but it is worth mentioning this possible scenario at this time. While Friday looks to be dry, it also expects to be the coldest day of the week with high temperatures not over the 60 degree mark and low temperatures generally around the freezing mark. It might be a good idea to check if your furnace needs some maintenance now in case you need to use it later this week. Going into next weekend, long term guidance shows an upper air ridge moving into the area. This will allow for temperatures to warm back up a bit as well as dry conditions to prevail. -078 && .AVIATION... VFR conditions are expected to continue at all REV TAF sites with dry conditions to begin the week. While winds will be generally light across the CWA today, an occasional gust of around 15 kts may be possible between 13/21Z and 14/03Z for KTRK and KMMH. Light and variable winds are then expected to persist through the overnight hours. -078 && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$