Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/02/21

Area Forecast Discussion
National Weather Service Bismarck ND
958 PM CDT Thu Apr 1 2021 .UPDATE... Issued at 958 PM CDT Thu Apr 1 2021 The Red Flag Warning has been allowed to expire. Most locations are now reporting humidity above 20 percent and sustained wind speeds below 20 mph. The RAP and HRRR are advertising dewpoints much lower for Friday afternoon than our current forecast (as much as 10 degrees Fahrenheit). This would have huge implications on the potential for critical fire weather conditions. Will allow additional guidance and upstream trends to be further evaluated before making any changes to the forecast. Updates to sky cover were based on the GFS 300 mb RH field, which seems to have a decent representation of current trends. UPDATE Issued at 636 PM CDT Thu Apr 1 2021 The main concern early this evening continues to be critical fire weather conditions. Many locations across western North Dakota continue to report relative humidity around 10 percent, with winds in the 10 to 20 mph range. Farther east, relative humidity is closer to 15 percent, but with winds around 15 to 25 mph. We expect a slow but steady improvement over the next few hours, with decreasing wind speeds and increasing humidity. The timing of the Red Flag Warning remains on track. Cloud cover was increased this evening based on current trends. && .SHORT TERM...(This afternoon through Friday night) Issued at 133 PM CDT Thu Apr 1 2021 Critical fire weather conditions continue across all of western and central North Dakota through this evening. At the surface, a diffuse warm frontal boundary has generally washed out as it has crossed the state and the pressure gradient continues to tighten a bit. This has led to some breezy conditions with sustained southerly winds up to 25 mph and gusts to 35 mph. Additionally, widespread observations of relative humidity values below 20 percent have been noted. These humidity values should continue to plummet through the afternoon, possibly down into the upper single digits in some locations. Along with very dry vegetation, these conditions suggest the Red Flag Warning for all of western and central North Dakota is in good shape through the evening hours. Most of the area should see highs in the 60s today but a few 70s will be possible across the southwest. Winds will start to relax after sunset and the critical fire weather threat will also gradually diminish as we lose daytime heating and dewpoints come up. The upper ridge axis will continue to move across the state overnight as a weak and dry shortwave skirts us to the north of the International Border, transitioning us into more of a zonal flow regime on Friday. We will likely see highs a bit warmer than today Friday afternoon, with plentiful readings in the lower 70s across the south. The very dry airmass will remain in place leading to another afternoon where humidity values will dip into the 13 to 20 percent range for most of western and central North Dakota. However, winds be lighter than today. Therefore, near critical fire weather conditions will once again be possible, but the lack of stronger winds should keep us from needing any headlines at the moment. The one area to watch will be east of the Highway 83 corridor where we may see northwest winds approaching 20 mph for a couple hours in the afternoon. Expect Friday night lows in the 30s. .LONG TERM...(Saturday through Thursday) Issued at 133 PM CDT Thu Apr 1 2021 We transition to low amplitude west northwest flow aloft through the weekend as the broad upper ridge across the west continues to nudge into the region. While the NBM has backed off a bit on high temperatures Saturday through Monday, we coordinated with our neighboring offices to trend towards the 75th percentile of the NBM guidance. Given the low amplitude ridging that will be in place and considering the NBM has been consistently been too cool recently for highs, this seems like a reasonable solution. This will mean widespread highs in the 70s and even a few 80s across the far south Saturday through Monday. Dry air lingers through the weekend, so any day with an increase in wind will raise fire weather concerns, likely through Monday or even Tuesday of next week. Next best chance for any precipitation will be next week after Monday, when more of a southwesterly flow pattern tries to develop. Uncertainty remains high amongst ensemble members, with the latest WPC cluster analysis trended towards less potential for much needed moisture, though not entirely dry either. The deterministic GFS remains the wet outlier showing a strong low moving through Tuesday through Thursday. However, looking closer at the ensemble members it is clear that the deterministic run is one of the more extreme outliers in the GEFS. Thus, wouldn`t put too much credence into its solution at this time. Will continue to hold slight chance PoPs in the forecast for this time period for now. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 636 PM CDT Thu Apr 1 2021 VFR conditions are expected through the forecast period. Southerly winds will remain sustained around 10-15 kts through tonight, turning to the northwest Friday morning and afternoon. && .BIS WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 10 PM CDT /9 PM MDT/ this evening for NDZ001>005-009>013-017>023-025-031>037-040>048-050-051. && $$ UPDATE...Hollan SHORT TERM...ZH LONG TERM...ZH AVIATION...Hollan
Area Forecast Discussion
National Weather Service Boston/Norton MA
1049 PM EDT Thu Apr 1 2021 .SYNOPSIS... Mid-level trough slides east on Friday, cold and mainly dry heading into Friday. Surface low moves north into the Gulf of Saint Lawrence while a surface high builds across the southeast. Seasonably cool and dry weather for the weekend under high pressure. Though generally dry, conditions turn more unsettled into early next week as an upper level low over the Maritimes shifts westward toward coastal New England. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... No major changes to the forecast this evening. Still getting some reports of sleet and graupel this evening. Not expecting it to accumulate much. Main tweaks were to temperatures and precipitation chances to reflect observed trends. 745 PM Update: Lower-level colder and drier air is beginning to filter southeastward behind the cold front aloft. Radar mosaic shows a band of precip along the front`s extent across eastern MA. The colder air in lower-levels has led to several reports of graupel or ice pellets from spotters in the Metrowest Boston area and from the weather observer at Logan Airport. RAP-based soundings bear this out with sub-0C wet-bulb temps around 950-900 mb in the cold air advection, suggesting some re- freezing of rain into pellets/graupel below cloud base. This band of precip will move eastward into the coastal waters in the next hour or so. While much of it will fall as light showers, there may continue to be some ice pellets mixing in at times but will not be impactful. The colder air leading to steepening lapse rates, along with 2.5-3 mb per 3 hr pressure rises are also contributing to increasingly blustery conditions in the post- frontal air, with NW gusts across most of interior MA, CT and RI in the 20 to near 30 mph range. Did opt to bump up wind gusts through 06z following the 18z guidance and recent RAP soundings. Thinking after midnight the gusts should start to lighten up, but occasional breezes may linger especially into eastern MA, Cape Cod and into RI given the cold advection all night. Though skies should begin to gradually clear out later tonight/overnight, northwest winds/gusts and falling temps will make it feel rather raw/chilly. Not exactly a great way to start the first evening of April for those who may prefer milder weather. Previous discussion: The leading edge of our mid-level trough continues to move off the coast of southern New England leaving a cold and dry air mass aloft. In fact, temperatures at 850mb are between -10C and -16C, and those temperatures are 10 to 16 degrees below the seasonal normal. This will support minimum temperatures Friday morning in the upper teens to low 20s across the interior and the upper 20s to low 30s across the coast. Winds remain gusty, at times gusting between 20 and 25 knots, making it feel as if it`s the low teens at the eastern slopes of the Berkshires and low 20s at the coast. Gusty winds will diminish by early Friday morning. As for precipitation, KBOX remains rather quiet heading into the mid afternoon. A few rain and snow showers do continue upstream, as seen on KENX, across Albany and points north and west. Those showers continue to dry out as it reaches the western Berkshire slopes. We did opt to leave low POPs in the forecast overnight as a few of these streamers could make it into western MA/CT. Otherwise, PWATS are crashing through the floor and the mid-levels dry out. But we are left with enough moisture in the lower levels will continue our overcast cloud cover through daybreak. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... Friday: The surface low that gave us the unsettled weather today will have had moved into the Gulf of St. Lawrence. During the day on Friday we have high pressure building across the entire east coast of the United States. At the mid-levels over our area the mid-level trough exits southern New England, but we expect a fair amount of cloud cover. Additionally, a weak surface trough could provide a few isolated showers. Confidence in any shower does remain low because PWATs are less than 1/4 of an inch. If anything a shower would be brief and more of a nuisance type of shower. As for temperatures, we are cooler still because of cooler than normal temperatures aloft. Afternoon temperatures are forecast to reach the low 40s with those across extreme western MA/CT might only make it to the 40 degrees. Friday Night: The mid-level trough moves east of New England and the surface high expands into southern New England, this will allow for diminishing clouds and once again cooler temperatures. The low will be dependent on how much of the cloud cover we erode. As of now we are looking at temperatures in the 20s across much of the area with the low 30s across the coastal plain of MA. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Highlights... * Seasonably cool but mostly sunny and dry for the weekend. * Greater cloudiness eastern MA/RI with limited chances for light showers into early next week as closed low in the Maritimes builds back towards coastal New England. Less clouds and milder temps western MA/CT. * Moderating conditions toward midweek. Details: Saturday: High-latitude blocking pattern over the North Atlantic will govern the large-scale pattern this weekend thru at least the middle part of next week. Deep trough initially over the Northeast shifts eastward and evolves into a closed low later Sat south of Nantucket, a feature which then passes into the Gulf of Maine into Sat night. Moisture related to this feature should stay far enough away from coastal MA Sat into Sunday to allow for mostly clear skies. 925/850 mb thermal trough also shifts east with moderating but still below-avg temps at these isobaric levels. By Sunday, 850 mb temps around -3 to -5C should be common across SNE. Surface high in place will also maintain dry weather. Should see highs in the mid-40s to low-50s Sat, with nighttime lows in the upper 20s to mid 30s. Somewhat milder temps aloft support highs in the 50s, on the lower side near the coasts and into the mid- upper 50s across most of the interior due to NW wind downsloping. Monday into Tuesday: The high-latitude blocking over the North Atlantic leads to a continued amount of uncertainty in this portion of the forecast. This pertains more to how far west will the closed low over the Gulf of Maine retrograde, which would influence the sky and temperature forecast across eastern MA/RI. The 12z suite of guidance now however shows more consistency in westward retrogression of the closed low into coastal New England by Tuesday. Did increase sky cover a bit over NBM guidance given this trend toward mostly cloudy for eastern MA and RI. There may be some very light showers also in this area but not a washout by any stretch and most should remain generally dry. Most of western/central MA and much of CT should stay far enough away from the closed low`s influence to allow for better conditions. Highs mainly in the 50s for Mon, with highs Tues well into the 50s to low 60s away from the coast. Under increasing clouds on Tues, highs near the coast in the mid to upper 50s. Lows generally similar each night in the upper 30s to low 40s. Wednesday: Bit larger variance in GFS/ECMWF guidance compared to early-week on how quickly will the closed low near coastal New England dig south. ECMWF is more optimistic with clearing early Wed allowing for clearing skies and warming temperatures associated with an amplifying ridge aloft to our west. On the other hand the GFS is slower and doesn`t really clear the closed low out until late Wednesday night and would maintain similar conditions to those around early-week. Will stick with NBM guidance more closely in this portion of the forecast until there is better agreement. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Tonight: High confidence. Generally VFR, with MVFR ceilings trending VFR across Cape Cod/Nantucket. NW gusts 20-25 kt early, and while gust speeds should start to lower after 03-05z, occasional gusts to 18-20 kt may continue into the overnight/pre-dawn hrs. Friday...High confidence. VFR with NW winds between 5-10 kts. Friday Night: High confidence. VFR with easing NW winds. KBOS TAF...High confidence in TAF. NW gusts may linger after 04z but with lighter gust speeds. KBDL TAF...High confidence in TAF. Outlook /Saturday through Tuesday/... Saturday: VFR. Breezy. Saturday Night: VFR. Sunday through Tuesday: VFR. Breezy. && .MARINE... Marginal Small Craft Advisories continue for the waters off the coast of southern New England through Friday afternoon. Northwest winds do remain gusty between 25 and 30 knots. Gusty winds diminish early Friday as the surface low moves north into the Gulf of Saint Lawrence. High pressure builds across the eastern half of the United States through the end of the weekend. Late Sunday into early next week a retrograding surface low will move westward towards the Gulf of Maine. Outlook /Saturday through Tuesday/... Saturday: Winds less than 25 kt. Areas of seas approaching 5 ft. Saturday Night through Sunday: Winds less than 25 kt. Seas locally approaching 5 ft. Sunday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Monday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Slight chance of rain showers. Monday Night: Winds less than 25 kt. Local rough seas. Tuesday: Winds less than 25 kt. Areas of seas approaching 5 ft. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 2 AM EDT Friday for ANZ230>234-236- 251. Small Craft Advisory until noon EDT Friday for ANZ235-237. Small Craft Advisory until 1 PM EDT Friday for ANZ250. Small Craft Advisory until 8 PM EDT Friday for ANZ254>256. && $$ SYNOPSIS...Loconto/Gaucher NEAR TERM...Belk/Loconto/Gaucher SHORT TERM...Gaucher LONG TERM...Loconto AVIATION...Belk/Loconto/Gaucher MARINE...Belk/Loconto/Gaucher
Area Forecast Discussion
National Weather Service Springfield MO
623 PM CDT Thu Apr 1 2021 .SHORT TERM...(This evening through Friday) Issued at 1214 PM CDT Thu Apr 1 2021 The key message of the short term forecast is the potential for a frost and freeze Friday morning. Surface high pressure will be building south into Missouri overnight. Light winds, clear skies and a cool airmass will aid radiational cooling and result in low temperatures in the middle 20s to lower 30s. The National Blend of Models depicts over an 80% probability of low temperatures below 32 degrees across the central and eastern Ozarks. Low temperatures will flirt with record territory at Rolla and West Plains. Surface winds in southeast Kansas and the Osage Plain will turn to the southeast overnight and will keep temperatures warmer compared to the Ozarks. Will continue with current frost and freeze headlines. Southerly surface winds will increase Friday in response to a tightening pressure gradient ahead of a lee-side trough in the High Plains. High temperatures will rebound to the mid 50s and 60s with dry weather. .LONG TERM...(Friday Night through Thursday) Issued at 1214 PM CDT Thu Apr 1 2021 The highlights of the extended forecast is a dry and warmer trend through Easter weekend into early next week. Chances for showers and thunderstorms return the middle of next week. Ensemble members are in solid agreement of an upper ridge building across the Plains. At the surface, south and southwest return flow will advect a warmer airmass. Look for high temperatures to jump above average to the 70s Sunday through the middle of next week. The next chance for precipitation will be focused on a shortwave trough tracking through the Pacific Northwest into the Central Rockies and ejecting into the Central Plains the middle of next week. Moisture advection is likely to be sufficient ahead of the approaching trough to support widespread rainfall. Lift and instability also support the inclusion of thunderstorms. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 617 PM CDT Thu Apr 1 2021 Mainly VFR conditions with light winds expected this TAF period. However, the HRRR model is bringing smoke from prescribed forest burns into the KSGF area after midnight tonight. Right now, that does not appear to cause significant visibility reductions, but time will tell. && .CLIMATE... Issued at 258 AM CDT Wed Mar 31 2021 A cold airmass will impact the Ozarks Thursday night. While the average last freeze for most of southwest Missouri is around April 15th, the warm weather over the past two weeks has jump started the growing season. Trees and plants have begun setting buds and leafing our and will be susceptible to freezing temperatures. Some areas may approach record lows for tonight into the morning of the 2nd. Below are the record lows for some locations across the Ozarks. Springfield Joplin West Plains Vichy Low Low Low Low Fri 20(1936) 25(1992) 22(1992) 24(1992) 2nd Forecast: 29 34 25 26 Multiple hours of temperatures in the middle 20s are forecast and will cause damage to sensitive plants and early growth. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...Freeze Warning from 1 AM to 9 AM CDT Friday for MOZ055>058- 068>071-079>083-090>092-095>098-104>106. Frost Advisory from 1 AM to 9 AM CDT Friday for MOZ066-067-077- 078-088-089-093-094-101>103. KS...Frost Advisory from 1 AM to 9 AM CDT Friday for KSZ073-097-101. && $$ SHORT TERM...Angle LONG TERM...Angle AVIATION...Titus CLIMATE...Angle