Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/15/22

Area Forecast Discussion
National Weather Service Indianapolis IN
1201 AM EDT Sat Oct 15 2022 ...Updated Aviation Discussion... .Forecast Update... Issued at 936 PM EDT Fri Oct 14 2022 No major changes needed with the ongoing forecast as conditions are generally evolving as expected. The area of rain over central Illinois associated with the approaching trough will arrive in the northwestern counties after 10 PM with a few hundredths of an inch of rain for those counties through 2 AM. The primary concern with these showers will be the potential for stronger wind gusts as the rain helps bring down the 40kt winds at cloud level. We`ve already seen a few gusts to 30kts ahead of the rainfall at LAF and FKR but as the temperatures continue to cool, the frequency of the stronger gusts will gradually decrease. Latest ACARs soundings show a minimal amount of elevated instability with these showers, so can`t rule out a few pieces of graupel in the stronger showers. Lows in the mid to upper 30s across the northwestern counties still looks probable, but will be dependent on how quickly the clouds begin to clear in the aftermath of rainfall. Will monitor these conditions through the night and make adjustments as needed. && .Short Term...(This evening through Saturday) Issued at 226 PM EDT Fri Oct 14 2022 * Critical Fire Weather conditions this afternoon * Gusty winds 35 to 45 mph * Showers possible this evening with gusty winds Today Temperatures across the region have warmed into the upper 50s to near 60 as of 2pm. Excellent boundary layer mixing to as high as 700mb has allowed for efficient downward transfer of momentum aloft. Low-level flow within the 925 to 700 mb layer is around 30 kts, based on soundings out of ILX. Winds at the surface have been gusting consistently to around 25 kts at IND late this morning and early this afternoon. A potent shortwave trough is modeled to reach Indiana by around 8pm this evening, and in the process gain a negative tilt. Winds in the aforementioned layer should increase as this feature closes in, with 850mb flow increasing to 40kts and 700mb flow to around 60kts. Therefore, wind gusts should gradually increase through the afternoon before tapering off as solar insolation is lost and stability returns. Gusts could top out around 35kts for most locations before the day is out. Additionally, very dry air in the lower levels is mixing down to the surface. Dew points at IND are already in the upper teens, with RH values around 16 percent as of 2pm. Skies have been trending clearer than forecast, so the lower end of guidance regarding RH is preferred for the remainder of this afternoon. Continued mixing should lead to RH values dropping to as low as 15 percent in places. The very dry and cloud-free air and deep mixing should allow high temperatures to reach their full potential this afternoon, which would generally be in the mid to upper 60s based on nearby soundings. The combination of dry and windy weather will lead to critical fire conditions today. Recent lack of significant rainfall has lead to low fuel moisture levels, currently between 7 to 10 percent as of yesterday. Any fires that manage to ignite today will have little issue spreading, so the Red Flag Warning issued previously is maintained through 8pm. Tonight The potent shortwave arrives this evening, with increasing clouds and potentially a few showers. As mentioned before, the low levels are very dry, so widespread rainfall is not anticipated. But strong positive vorticity advection and diffluence aloft will lead to an enhanced area of lift as the system moves through. Additionally, some weak CAPE around 100 J/kg at the top of the mixed layer may enhance the convective nature of any showers this evening. In fact, some of the CAMs, namely the HRRR and 3km NAM, depict a more cellular appearance to the shower activity this evening. Model soundings indicate that any convective elements would be rather shallow, as a broad cap resides around 600mb. Nevertheless, strong low-level flow as mentioned earlier could easily be brought to the surface within the stronger showers. Therefore, wouldn`t be surprised to see some non-severe gusty winds associated with shower activity later on. The best chance would be north of a Terre Haute to Indianapolis line, which is closer to the best dynamics ahead of the approaching shortwave. The synoptically driven wind should die down quickly as daytime heating is lost, as it is primarily driven by surface mixing. Wind associated with the showers could persist a bit longer, however. As the system departs, skies should gradually clear throughout the night. Large scale troughing over the Great Lakes is maintaining a cooler air mass aloft, which should allow for a rather chilly overnight if ideal radiational cooling conditions materialize. Weak surface CAA / a cold front behind the shortwave will aid in cooling potential overnight. The most likely locations for maximized cooling would be the northwestern part of the CWA, which is deeper into the post-front air mass and will see clearing earlier compared to places further south. Lows should dip into the mid 30s across our north, but only into the low 40s south of Indianapolis. Patchy frost is possible, but dry low-levels and a residual breeze should prevent it from being too widespread. Tomorrow Benign weather is anticipated to start the weekend, at least compared to today`s weather. Surface high pressure will be in control, and light winds along with mainly clear skies should prevail. An area of high clouds may arrive mid afternoon as a weak wave aloft slides in from the west. High temps are expected to be cooler than today, but not significantly so. && .Long Term...(Saturday night through Friday) Issued at 226 PM EDT Fri Oct 14 2022 Significant Weather Highlights: * Widespread freeze conditions likely multiple mornings early-mid next week * Hard freeze possible, which would officially end growing season A fairly stagnant upper level pattern is expected much of the long term period, featuring a western CONUS ridge/Rex block and eastern CONUS trough/closed upper level low. This will lead to mainly dry conditions, with much below normal temperatures expected for at least a significant portion of the period, particularly the early to middle portion of the coming work week. A dry cold front will move through the area late Sunday, followed by a blast of cold air accompanying a strong surface high pressure system driven southward in the highly amplified flow by a nearly meridional polar jet stream. The overall cyclonic flow aloft will allow some lake effect clouds and perhaps a low chance for light precipitation to nudge into northern/northeastern portions of central Indiana late Monday into Tuesday, but the larger story will be the anomalously low temperatures, which look nearly certain to deliver widespread freeze conditions one or more nights next week, with a hard freeze not out of the question (which would officially end the growing season and frost/freeze headlines for the area). Ensemble data suggest that Tuesday night should be the coldest period, with temperatures quite cool about 24 hours either side of this time, and suspect that blend may be underselling the degree of the cold expected. Will be trending temperatures, especially lows, toward the low end of the guidance envelope as a result. Lake effect could complicate this in the north/northeast, but these uncertainties will come into clearer view with time. Nonetheless, well below normal temperatures will dominate much of the long term period, with some moderation in temperatures expected very late in the period. && .Aviation...(06Z TAF Issuance) Issued at 1201 AM EDT Sat Oct 15 2022 Impacts: - VFR Conditions are expected this TAF period. Discussion: A cold front quickly moving across the TAF sites will quickly exit the area within 1-2 hours after 06Z. GOES16 shows mainly mid level cloud across the region with this feature. These VFR clouds will quickly exit to the east overnight as the front departs and high pressure centered over IA/NB begins to push into IL and IN. Although cyclonic flow is expected to remain in place aloft overnight and the rest of Saturday, the surface high pressure to the west will continue to build across Indiana. Forecast soundings show a very dry column through the rest of the period with unreachable convective temperatures. Thus continued VFR conditions. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ Update...White Short Term...Eckhoff Long Term...Nield Aviation...Puma
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
856 PM CDT Fri Oct 14 2022 .UPDATE... Issued at 855 PM CDT Fri Oct 14 2022 The current forecast remains in good shape this evening with just minor adjustments made to match trends. A cold front which is located along the I-57 corridor continues to push eastward across the area this evening which has lead to the widespread showers that are moving into northwestern Indiana. These showers will gradually come to an end as the front clears the area around midnight with clearing skies and easing winds expected for the rest of the overnight hours. The clear skies will allow temperatures to cool into the low to mid 30s across most of the area with a few sites possibly dipping into the upper 20s. The expectation of widespread temperatures near or below freezing has prompted the issuance of Freeze Warning for portions of northern and northwestern Illinois which means that those in this area with sensitive plants should take measures to protect them from the cold. As for our Saturday, expect temperatures to top out in the low to mid-50s tomorrow afternoon with partly sunny skies. Winds will also be a tad breezy again, but with gusts around 20 mph during the afternoon. Similar conditions are expected for Sunday with slightly warmer temperatures in the mid to upper 50s. Yack && .SHORT TERM... Issued at 302 PM CDT Fri Oct 14 2022 Through Saturday... Forecast concerns for this evening are a period of gusty winds along with a two to three hour window of showers. Also, while the growing season is rapidly fading, there will be subfreezing temperatures in parts of far northern and north central Illinois. GOES-16 visible imagery has shown clouds spreading rapidly over the area this mid-afternoon. This will by 4 PM over locations east of I-57 where red flag conditions had been met with multiple sites between 15 and 25 percent relative humidity and gusting to 30 mph. While the winds will increase some into early evening, the fire weather threat will ease due to gradually increasing relative humidity and the likelihood of showers. So no changes planned to the Red Flag Warning, but burning is continued discouraged through the entire evening. Satellite water vapor imagery is depicting a pronounced upper wave and attendant upper jet of 100+ kt sweeping across Iowa. Forcing for ascent ahead of this is shown on satellite with increasing cloud cooling over the area as well as a growing shower footprint across Iowa. This forcing will further increase immediately ahead of the wave and concurrent with a strengthening surface cold front presently just west of the Mississippi River. Showers should continue to blossom as these features progress closer, with the shower timing for the forecast area from 530 to 10 P.M. With the colder air advection sweeping into an inherent well mixed air mass, there will be potential to mix down some enhanced gusty winds with any downdrafts. There were a couple upstream sites along the Iowa-Missouri border to have 40+ mph winds (even a 51 mph gust at Lamoni, IA), and those were without showers. The top of the channel on forecast RAP and HRRR soundings show potential for 40+ mph gusts, and am noting that temperatures are actually not dropping underneath the cloud layer (i.e. atmosphere staying mixed). So there is a window of opportunity for gusts up to near 50 mph. Behind these showers, the clouds look to clear into early overnight. With the cold advection, temperatures look to be drawn down to freezing in the northwest forecast area. Because we are continuing growing season products at this time, we have issued a Freeze Warning. Further east and south, frost likely will be hard to come by given continue winds of ~10 mph overnight. For Saturday, some stratocumulus may be seen, but otherwise should be just high clouds with continued breezy westerly winds. Highs in the lower to mid 50s are forecast by a high majority of guidance and that lines up well with climatology for 925 mb temperatures of +1 to +3C. MTF && .LONG TERM... Issued at 253 PM CDT Fri Oct 14 2022 Saturday night through Friday... Key messages in the extended forecast period: 1. Well below normal temps expected - Especially cold and blustery MON-TUE 2. Dry conditions for most of the area next week - Lake effect showers MON-TUE mainly into NW Indiana The upper level blocking pattern remains in place for much of the extended period with troughing across the eastern CONUS and Rex block across the west. Heading into Saturday night a reinforcing shortwave moving beneath the upper trough and associated surface boundary will move across the area into early Sunday morning turning winds northwesterly. Temperatures Sunday should still manage to warm into the 50s to near 60. A reinforcing surge of cold air then moves in late Sunday. This will usher in a cold and blustery two days with highs only in the 40s and northerly winds gusting up to 30 mph both Monday and Tuesday. Expecting dry conditions for most of the area this weekend through midweek other than some lake effect showers into northwest Indiana Monday into Tuesday as a shortwave pivots around the upper low. Also can`t rule out some snowflakes in there but think the warm lake temperatures should limit this. Toward the latter half of next week there are signs that the western ridge may start to break down with temperatures warming back into the 50s to near 60 Thursday and Friday as shortwave ridging shifts moves a bit closer to the area. Petr && .AVIATION... For the 00Z TAFs... Aviation Forecast Concerns: * Brief period of gusty west winds around 35 kts early this evening, and a period of light rain/showers in VFR conditions. * Breezy west-southwest winds gust around 20 kts Saturday afternoon. Surface low pressure was analyzed just east of KMKE early this evening, with a trailing cold front trailing across the Chicago metro terminals into western IL/central MO. Winds are shifting westerly with the passage of the cold front, and may continue to briefly gust above 30 kt with and immediately behind it early this evening before gradually diminishing. While low levels are initially very dry, a strong mid-level disturbance was providing sufficient forcing/ascent to saturate the column and produce an area of light rain/showers, which will linger for a few hours early this evening before clouds dissipate overnight. Surface high pressure will build south of the region across the lower Ohio Valley on Saturday, while another in a series of cold fronts approaches from the northwest later into the evening. Surface winds will gradually back from west to southwest through the afternoon, becoming somewhat breezy again with gusts around 20 kts. Gusts will subside Saturday evening, though southwest winds should remain near 10 kts ahead of the approaching cold front which moves in beyond the end of this TAF period. Otherwise, VFR conditions will prevail. Ratzer && .LOT WATCHES/WARNINGS/ADVISORIES... IL...Freeze Warning...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011- ILZ012...1 AM Saturday to 8 AM Saturday. IN...None. LM...Small Craft Advisory...Winthrop Harbor to Burns Harbor until 4 AM Saturday. Small Craft Advisory...Burns Harbor to Michigan City IN until 10 AM Saturday. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Pueblo CO
247 PM MDT Fri Oct 14 2022 .SHORT TERM...(This evening through Saturday) Issued at 245 PM MDT Fri Oct 14 2022 Key Messages: 1) A Frost Advisory has been issued for Crowley and Kiowa counties from 3am until 8am Friday morning. 2) A dry cold front will pass through tomorrow, bringing easterly winds and slightly cooler temperatures for our Saturday. Currently.. Relative humidities have fallen into the single digits for most of the high country, with a lot of the plains already down to near 10% as well. Winds have began to calm and shift more northerly and easterly as the pressure gradient relaxes across the region. Not expecting any cloud cover or precipitation this afternoon, but we do have a couple of prescribed burns going on in Chaffee and Huerfano counties, where smoke plumes are starting to become apparent on visible satellite imagery. Rest of Today and tonight.. We remain in northwesterly flow aloft as longwave troughing sits across the eastern half of the country and a low pressure system begins to push onshore near the southwest coast of California. A Frost Advisory has been issued for Crowley and Kiowa counties from 3am until 8am Friday morning. Expecting radiational cooling to be strong on our plains tonight with all of the dry air being advected into the area today. Downsloping winds will help to keep our mountain adjacent plains slightly warmer and drier, but expecting frost to be likely for areas north of highway 50 and east of the I- 25 corridor where dewpoints recover into the upper 20s by around sunrise. Will continue to monitor eastern Pueblo county and Prowers county, where frost formation looked more marginal, but still possible. In the high country, expect overnight lows to be near or below freezing again tonight. Tomorrow.. Deterministic models push a backdoor cold front across our plains on Saturday morning. The HRRR brings this boundary in between about 10am and noon tomorrow. Models are in close agreement that we will stay dry behind the front, and winds will quickly become easterly after its passage. Skies are expected to stay mostly clear tomorrow, with temperatures rising to near normal for daytime highs. Warmest temperatures will stay southeast, with Baca and Prowers counties warming into the upper 70s. Elsewhere on the plains we`ll see highs in the low to mid 70s, with mountain valleys warming into the 60s and higher terrain seeing highs in the 50s. .LONG TERM...(Saturday night through Friday) Issued at 245 PM MDT Fri Oct 14 2022 Key Messages: 1) Cool and cloudy Sunday for most, with precipitation along southern portions of Colorado. 2) Drier and warmer pattern expected to develop next week for southern Colorado. Saturday Night... The start of the long term period will bring some active weather to southern Colorado. During late Sunday/early Saturday timeframe, a short wave trough just to the northeast will race to east, and is expected to push a cold front southward across the region, with northerly winds behind it. This is anticipated to be a dry cold front though, as moisture and surface forcing will be on the modest side. Given that, dry conditions are expected across southern Colorado. As for temperatures, despite the cold front, increasing cloud cover will keep temperatures slightly warmer than the past few previous nights. The plains will cool into the low to mid 40s, the mountain valleys will drop into the 30s, and the mountains will fall into the mid 20s to low 30s. Sunday... Weather picks up in activity some across the region for the end of the weekend. Ensemble model guidance, such as the GEFS and EPS, are in good agreement about the pattern Sunday. Synoptically, a closed low will slowly trek across New Mexico, just south of the Colorado state line. This low will bring increased synoptic ascent and better flow to the region. Given the support from the low, and stronger orographic forcing from the better flow, precipitation is expected to develop starting around mid morning and continue through the afternoon. With that said though, the aforementioned short wave will confine higher moisture to the south/southwestern part of the state, particularly along the San Juan and Sangre de Cristo Mountains. Given the lack of greater moisture, precipitation will be more scattered in nature. At lower elevations, winds behind the cold front are expected to become more easterly during the day, starting in the morning. The easterly winds will induce persistent surface upsloping during the day. Given these easterly winds, along with a modest uptick in surface moisture behind the front, overcast skies are likely across much of the eastern plains, especially along portions of the southern I25 corridor. Looking at temperatures, a much cooler day is expected given the cold front and widespread cloud cover. Given this, most across southern Colorado are expected to be below average throughout the day. Monday - Friday... For the rest of the long term period, a more quiet stretch of weather is expected. Ensemble guidance continue in agreement about the pattern. Starting Monday, troughing out east and ridging out west is expected to redevelop over CONUS, with northwest flow over Colorado. As this pattern develops, the aforementioned low will become ingested into the troughing out east during the day Monday, and persistent northwest flow is expected after that. This pattern will bring drier air into the region, which will lead to low precipitation chances, with the exception being around the San Juan Mountains Monday as the low moves east. This pattern will also bring above average temperatures to southern Colorado, especially for the eastern plains. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 245 PM MDT Fri Oct 14 2022 VFR conditions are expected at all three TAF sites, KCOS, KPUB, and KALS. At KCOS and KPUB, winds will continue to remain mostly easterly this evening, before switching back to northerly overnight. A weak cold front is expected for Saturday morning, which will bring northerly and easterly winds for the rest of the day tomorrow. At KALS, winds will remain light and diurnally driven. Sky conditions are expected to be mostly clear throughout the period and no precipitation is expected at any of our TAF sites. && .PUB WATCHES/WARNINGS/ADVISORIES... Frost Advisory from 3 AM to 8 AM MDT Saturday for COZ089-095-096. && $$ SHORT TERM...EHR LONG TERM...SIMCOE AVIATION...EHR