Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/23/22


Area Forecast Discussion
National Weather Service La Crosse WI
1045 PM CDT Thu Sep 22 2022 .DISCUSSION...(This evening through Thursday) Issued at 204 PM CDT Thu Sep 22 2022 Key Messages: - Frost likely in central/northern Wisconsin, northeast of I-94 tonight. Protect any plants as needed. - Showers move in from the west Friday, finally making it to WI late and into the evening/overnight. A diminishing but lingering rain chance in WI Sat/Sun. Amounts of less than 0.25" total expected. - Cool weather continues into mid-week, frost/freeze possible Wednesday morning. Tonight: Frost/Fog potential The surface ridge will progress into the western Great Lakes overnight. RAP soundings indicate a deep light wind layer through early morning before southerly flow begins to increase later overnight in response to an approaching mid-level trough upstream. With favorable radiational cooling conditions, especially east, chilly temps down into the mid 30s appear likely over typically cooler areas of central into north-central Wisconsin with potential for readings near or below 30F in some spots, which would be near the NBM 5th percentile. Collaborated to include a frost advisory for central into north-central WI overnight into early Friday morning. In addition, given the light wind layer, some fog could develop in low-lying areas of central WI and in river valleys, but confidence in a more widespread fog event is reduced due to the increasing flow aloft later in the night and potential for higher level clouds at times. Friday-Sunday: Showers spreading east, lingering Synoptic lift/warm advection will increase ahead of the approaching trough on Friday. The lift signal looks to be concentrated in the mid-levels and weakens somewhat with eastward extent through the day. Areas of showers will spread east during the day but could battle dry air in the low-levels as they work east into western and central WI. Regardless, amounts should be on the lighter side, up to around 0.10" west, with limited thunder risk given weak destabilization at best. The weekend will be dominated by large scale troughing as the flow consolidates and begins to amplify across North America. Friday night should be wet in most places with the well-agreed on secondary/main shortwave trough moving across the area from W->E with moderate 500-300mb Qvector convergence. This forcing will couple with low-level warm advection and the N-S moisture tongue to increase and push rain chances into WI overnight. With upstream ridge amplification over western North America, and upstream trough energy over central Canada, the large scale trough deepens and lingers over the Great Lakes. This will linger rain chances over mainly WI through Sunday. Confidence is lower in this hard to model north/northwest flow and transient wave intensity could be stronger and thus more widespread light rain could occur in WI /esp central/ Saturday night and Sunday (or weaker and lighter!). For now have left rain chances in the 30s but feel the direction they move would be up in future forecasts. Monday-Thursday: Continued cool Consolidation and amplification of the large scale flow pattern over North America continues next week with repeat shortwave trough energy affecting the local area in northwest flow. These waves emanate from the Yukon where more limited satellite and observational data initialization lower model skill. While the larger ideas yield a cool pattern continuing, details on the precipitation timing is of low confidence this far out. There seems to be signal in the EC/GEFS ensembles for a strong trough moving through in the Monday / Monday night period reinforcing the cool air and providing a light rain chance for the area. The 22.06Z GEFS solution would suggest a 20-30% chance of measurable rain mainly northeast of La Crosse, where the EC ensembles have 60-70% placed in WI. Again, as this time frame approaches, it is likely rain chances will change. This trough and cold front bring the coldest air of the season in with ~50% probability of <0C at 850 mb northeast of I-94 and consensus highs in the low 50s! This could mean a freeze Wednesday morning and the forecast was lowered 4-5F cooler vs. previous. Large scale progression of the western North American ridge with southerly flow and warming is pretty well agreed upon for late week, with only timing differences for the onset. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1045 PM CDT Thu Sep 22 2022 Confidence in fog for the rest of the night has decreased given the influx of high clouds that has arrived sooner than previously progged. Still maintained some mention of localized non- restrictive fog at LSE, but there is a strong possibility that this may not happen. Confidence is also on the lower side with the coverage of showers during the day, with the best potential for rain shaping up to be west of the Mississippi River before 00Z. Winds increase from the south during the day with gusts of 20-25kts likely west of the Mississippi River. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...Frost Advisory until 8 AM CDT Friday for WIZ017-029-034-042>044. MN...NONE. IA...NONE. && $$ DISCUSSION...Baumgardt/JM AVIATION...Skow
Area Forecast Discussion
National Weather Service Columbia SC
752 PM EDT Thu Sep 22 2022 .SYNOPSIS... A cold front will cross the area overnight. Much cooler and drier air will move in behind the front for Friday, then we once again begin a warming trend for later in the weekend. Another cold front will cross the region early next week with another round of cool and dry air. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Cold front at 23z still in the Upstate region...the pre-frontal trough moving toward the coastal plain. Widely scattered ahead of the front...mainly along the pre-frontal trough will exit the Midlands soon. However, a few showers remain to the west but should diminish during the next hour or two as the front pushes to the southeast. The Rap model has the front moving to the southeast of CAE by 1100 pm. Behind the front, wind will urn northwesterly and increase to around 10 to 20 mph with gusts to near 30 mph possible. Based on the gusty winds expected will continue Lake Wind Advisory until 800 am since stronger winds more likely on the warmer area lakes. Much cooler and drier air moves in overnight, and temperatures by morning will feel very refreshing with readings in the mid 50s in the western Midlands and Pee Dee to around 60s in the southern CSRA and southeastern Midlands. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... Absolutely beautiful conditions expected on Friday and Saturday. Strong cold air advection is expected to continue through much of the day on Friday as the cold front races off the eastern US coast. Gusty winds out of the north are expected before noon, with winds tapering off through the afternoon. Surface high pressure will push into the Mid Atlantic through the day, and maintain sunny skies and cool temperatures. PWs are forecast to be below the 10th percentile across the region during the afternoon, with values approaching 0.3"- 0.6" across the region. Highs are expected to remain in the upper 70s across the region during the afternoon. Overnight, prepare to feel the first taste of fall across the area. Temperatures are likely to plummet into the low 50s in many spots, and possibly into the upper 40s in our cooler spots. Dewpoints will be in the 40s much of the day tomorrow, which will make it easier to see radiational cooling. Saturday looks equally beautiful. PWs will slowly be on the rise through the day but will still be a bit below normal across the region. With high pressure dominating to our north, we`ll likely see mostly sunny skies across the region with slowly moderating high temps on Saturday afternoon into the low/mid 80s. Temps overnight will fall into the upper 50s and low 60s. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Lots of uncertainty in the long term period, especially towards the middle of next week. However, confidence is fairly high in what is going to go down ahead of that time frame weather wise. On Sunday, the surface high will quickly shift eastward ahead of an approaching deep trough from the upper Midwest. Winds will shift out of the south and southwest through the day, and result in another brief warm up across the region. Expecting highs to get into the upper 80s again on Sunday afternoon. The front will likely be strong enough and see good enough moisture advection ahead of it to result in some isolated showers along the front on Sunday night. Strong surface high pressure will push in behind this, and will settle in to our north or northwest on Monday and Tuesday, and will lead to temps falling back to near or slightly below normal values across the region. Rain isn`t expected on Monday or Tuesday as PWs are forecast by ensembles to be well below normal. There is good agreement that troughing will dominate the mid and upper levels of the atmosphere by the middle of next week. Outside of that, there is much uncertainty in the forecast as we get towards Wednesday and Thursday. With a strong high pressure sitting to our northwest, it is likely that temps will be seasonal or below normal during this time as well. && .AVIATION /23Z THURSDAY THROUGH TUESDAY/... A cold front will move through the region overnight. Showers are unlikely as dry air moves into the area and impedes convective development. Winds will remain gusty through the night with gusts to around 20 kts at times. NW winds this evening will become northerly by midnight then NE early Friday morning. LLWS conditions appear unlikely tonight since surface winds will stay up through the night. The airmass will be too dry to support fog or stratus. Friday will not be as breezy with clear or mostly clear skies and NE winds around 5 to 10 kts. EXTENDED OUTLOOK...An upper trough will push into the region late this weekend and early next week increasing rain chances and associated restrictions. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...Lake Wind Advisory until 8 AM EDT Friday for GAZ040-063>065- 077. SC...Lake Wind Advisory until 8 AM EDT Friday for SCZ016-018- 020>022-025>031-035-037-038-041-115-116-135>137. && $$
Area Forecast Discussion
National Weather Service Cheyenne WY
541 PM MDT Thu Sep 22 2022 .SHORT TERM...(This evening through Friday night) Issued at 211 PM MDT Thu Sep 22 2022 Cool and cloudy conditions have persisted for a majority of the cwa east of I-25 through 20Z this afternoon. In addition to this, widespread low cloud ceilings and dense fog at times has plagued the area with visibility less than 1 mile for several areas along the I-80 corridor from the Summit to Cheyenne County earlier today. Further to the west of the Laramie Range, much drier air and breaks in cloud cover have allowed for temperatures to reach the 60s to near 70 degrees. This break in cloud cover combined with weak instability produced weak thunderstorms moving from west to east. Wind gusts up to 50+mph were observed as the showers and thundershowers pushed through. The hi-res model guidance from the HRRR and NamNest brings low ceilings and patchy fog back into the I-80 corridor late this afternoon and evening before dry air moves into the region. This subsidence will become much more abundant as the overnight hours occur. Omega fields and other model guidance continues to show a strong signal for mountain wave activity beginning by 6Z-9Z late tonight. This will combine with energy being present from a passing potent shortwave aloft to our north and east overnight. The wind prone corridors will see the first response of strong wind gusts of 55-65mph by 12Z Friday due to 700mb winds reaching 55-60 kts at H7 heights. As daytime mixing occurs because of mostly sunny skies and dry conditions being present, the strong wind gusts will push further to the east across additional weather zones in SE WY. Breezy conditions of 35-45mph wind gusts can be expected into the NE Panhandle at times through early afternoon Friday. The wind prone corridors of I-25/I-80 will see wind gusts up to 65mph. With this occurring on a Friday, there could be a higher blowover risk as commuters may plan on going to weekend destinations. Wind gusts should dissipate by sunset on Friday. Localized temperatures due to downsloping effects will create warmer temperatures in the mid to upper 70s, instead of guidance in the low 70s. Have decided against going with a possible fire weather headline as the strong winds will be present and minimum RH should create only elevated concerns at best due to the recent rainfall. Dry conditions will be present overnight Friday as seasonal temperatures in the 30s and 40s are expected. .LONG TERM...(Saturday through Thursday) Issued at 211 PM MDT Thu Sep 22 2022 KEY MESSAGES: 1) Gusty winds through Saturday afternoon with gusts 30 to 35+ mph possible. 2) Dry and warm conditions through the end of the long term period. 3) Next chance for precipitation is Thursday. DISCUSSION: Gusty winds are expected to decrease throughout the day Saturday as a brief cool front moves through and a low pressure system pushes east along the Canada/US border and a deep ridge develops across the western US, decreasing the pressure gradient across southeast Wyoming and the Nebraska panhandle. A brief shortwave passage Tuesday will give chances for elevated wind gusts once again, but high winds are not expected at this time. This shortwave trough passage will pave the way for the next point of interest in the long term forecast Wednesday into Thursday. This quick shortwave trough currently looks to break down the ridge enough the eject moisture into the area, increasing shower/ thunderstorm chances, mainly Thursday. Temperatures jump back to above normal for this time of year. Average high temperatures are in the upper 60s to 70s. Temperatures start above normal Saturday with highs in the mid- to upper-70s, then drop to normal Sunday. Beginning Monday as the ridge axis shifts eastward, temperatures gradually increase each day with Wednesday and Thursday being the warmest days with highs in the 70s to 80s. Overnight low temperatures will be right about average with low in the 40s in southeast Wyoming to low 50s in the Nebraska panhandle. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 540 PM MDT Thu Sep 22 2022 Current satellite imagery has clearing moving from west to east across southeastern Wyoming with lingering low ceilings across the Nebraska Panhandle. Should expect these trends to continue on the Wyoming side with mostly downsloping winds evident from current observations, and the Nebraska Panhandle expected to follow in the late night hours. Main concerns into tomorrow is the chance for some fog conditions to set up across KBFF from 11z to 14z with HiRes model guidance being consistent between products. With that being said, confidence remains low at this time with mostly a downslope component to the wind, limiting the development of fog. However, started trending those visibilities down and will re- evaluate later on tonight. Looking into tomorrow, mostly strong winds are expected across the terminals with strong winds at 700mb mixing down to the surface. && .FIRE WEATHER... Issued at 211 PM MDT Thu Sep 22 2022 Cool and cloudy conditions will persist today for FWZs across the NE Panhandle, but clearing from west to east will allow dry air to move into the region. Min RH values of 20-30% across Carbon County will exist by late this afternoon. Very strong winds will be present on Friday as west to southwest winds sustained at 25-35mph with gusts up to 45-55mph are anticipated across Southeast WY FWZs. Areas in the wind prone corridors could see gusts to 65mph. All this being said will account for elevated fire weather conditions on Friday, and near critical conditions are possible on Saturday for FWZs in SE WY. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...High Wind Warning from 3 AM to 3 PM MDT Friday for WYZ106-116- 117. High Wind Warning from midnight tonight to 3 PM MDT Friday for WYZ110. NE...None. && $$ SHORT TERM...BW LONG TERM...LK AVIATION...MRD FIRE WEATHER...BW
Area Forecast Discussion
National Weather Service Goodland KS
948 PM MDT Thu Sep 22 2022 .UPDATE... Issued at 803 PM MDT Thu Sep 22 2022 Based on lowering visibility trend at Goodland, and webcams across Sherman County, added fog to the evening hours. The dense fog is patchy, and am thinking it should remain so through the night. UPDATE Issued at 552 PM MDT Thu Sep 22 2022 Due to the low levels of soundings being saturated, and weak isentropic lift occurring in that layer, have prolonged precipitation chances into mid morning Friday. UPDATE Issued at 531 PM MDT Thu Sep 22 2022 Latest near term models are indicating the current rainfall moving through is the only round of rainfall that will occur for the night. Based on this have shifted the higher rainfall amounts to the early evening. There could be lingering rainfall after the main round moves through due to weak isentropic lift occurring, so have low chances for rainfall lasting into the overnight hours. && .SHORT TERM...(This evening through Saturday) Issued at 319 PM MDT Thu Sep 22 2022 At the beginning of the short term period, the latest RAP analysis shows the CWA underneath the back half of an upper air ridge with a strong upper air low over MT giving the CWA a west-southwesterly flow aloft. Current satellite and radar imagery along with surface observations show cloudy skies across the region with scattered slightly lower visibilities as well as precipitation moving into eastern CO. Forecast models depict the low over MT moving eastward into ND overnight causing the CWA`s upper air flow to speed up quite a bit. At the surface, precipitation chances look to spread across the CWA from west to east going into the evening hours and last until after midnight when they depart to the east. Both the current runs of the HRRR and NAMNest show better chances for precipitation for areas south of I-70. QPF values look to range from a trace to a few tenths in the southern portions of the CWA. Overnight lows expect to be in the upper 40s to lower 50s. On Friday, the CWA expects to see a westerly flow aloft as the upper air low continues is eastward progress as a ridge builds over Pacific Northwest overnight. At the surface, early morning patchy fog is possible across the entire CWA after the precipitation chances depart as several models show lower visibilities with a very small dewpoint depression. Not too certain on how low the visibilities can go as models continue to differ in this aspect as well as locations of the lower visibilities, but will continue to monitor it and hold off on a fog advisory at this time. Skies look to clear by the afternoon and dry conditions are expected for the CWA throughout the rest of the day. Friday`s daytime highs look to be in the upper 70s to lower 80s followed by overnight lows similar to those on Thursday night. For Saturday, model guidance shows the front part of the western ridge making it over the CWA by the evening hours turning the flow aloft to a more northwesterly direction. At the surface, dry conditions look to continue with sunny skies throughout the day. Fire weather conditions are not anticipated with current forecast minimum RH values being around 20 percent and wind gusts staying below criteria. Daytime highs for Saturday expect to be in the upper 70s to middle 80s range with overnight lows in the middle 40s to lower 50s range. .LONG TERM...(Sunday through Thursday) Issued at 241 PM MDT Thu Sep 22 2022 For the long term, generally dry and warm conditions are expected across the area. A disturbance around the early/mid part of the week may briefly lower temperatures and bring a low chance for rain. The upper level pattern is forecasted to be defined with a high amplitude ridge over the Western CONUS and a high amplitude trough over the Eastern CONUS. This will put the area in northwest flow aloft. While northwest flow generally allows for some more active weather, the high amplitude of the ridge will generally keep the area dry and disturbance free except for around Tuesday/Wednesday when a shortwave is forecasted to potentially undercut the ridge. As the previous discussion mentioned, this shortwave isn`t looking too good for bring rainfall or much cooler temperatures though Tuesday could be a few degrees cooler than the rest of the week. Still a chance for a few storms can`t be ruled out. Otherwise, the rest of the period is forecasted to be near to slightly above average in temperatures with highs in the 80`s. Dry conditions will prevail with the possibility of RH values dropping into the teens and 20`s. Fire weather conditions look to be unlikely as winds are forecasted to be relatively light with the lack of disturbances and broad features. Towards the end of the period, there is some more uncertainty as to how conditions will evolve given the potential for a hurricane in the Gulf of Mexico as suggested by long term guidance. The hurricane may affect the evolution of the trough that is forecasted to move into the northwest around the mid part of the week. Currently keeping the dry and warm as current guidance would trap the upper ridge over the Plains. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 944 PM MDT Thu Sep 22 2022 IFR to VFR conditions forecast for the TAFs. Patchy dense fog is occurring over the forecast area. Am expecting this to continue past sunrise. The IFR ceiling should lift after 12z, but possibly before for KGLD. Have based the timing on the clearing currently occurring along the Rockies, which lines up quite well with a few of the preferred models. KMCK may increase to MVFR for a short time as the west edge of the cloud cover approaches in the morning. Otherwise winds will be light through the TAF. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...076 LONG TERM...KAK AVIATION...JTL