Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/19/20

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
620 PM CDT Fri Sep 18 2020 .UPDATE... Issued at 619 PM CDT Fri Sep 18 2020 No major changes are planned to the current forecast this evening. && .SHORT TERM...(This Evening through Saturday Night) Issued at 310 PM CDT Fri Sep 18 2020 Forecast challenges surround fire weather and temperatures through a smoke layer. Currently, beneath a sunny sky, temperatures are warming through the 60s and 70s on south-southeasterly breezes. Dry weather conditions are forecast for most of the next 36 hours over this CWA. The beginnings of some slight chance pops show up across the far western CWA late Saturday night when steep mid-level lapse rates and approaching shortwave energy combine. There is some decent low level WAA occurring later tonight through Saturday night, as well. Not sure how much that will be offset during daytime heating hours on Saturday when the next surge of smoke plume aloft (per the latest HRRR) is over the CWA. Breezy southeasterly boundary layer winds on Saturday should help to keep low level moisture from disappearing during peak heating/mixing on Saturday. The lone exception might be down across Stanley, Jones and Lyman counties in the afternoon where RAP model low level RH progs along and south of an establishing Lee-of-the- Black-Hills surface trof could tank to around 20 percent, especially if any amount of westerly component can be introduced into the boundary layer mixing wind Saturday afternoon/evening. .LONG TERM...(Sunday through Friday) Issued at 310 PM CDT Fri Sep 18 2020 The long term portion of the forecast will feature above normal temperatures with below normal precipitation. Fire weather will be a concern at times through the long term. The period begins on Sunday with an area of low pressure and upper level trough crossing the region. There may be enough instability and forcing associated with the frontal boundary for isolated thunderstorms on Sunday. While severe storms are not expected, inverted V-sounding, along with over 1,000 J/kg of DCAPE does support the potential of gusty winds with the thunderstorms. Another low pressure system will track across the region midweek, bringing a round of isolated showers and thunderstorms. Upper level ridging will build over the Northern Plain Thursday afternoon through Friday. The ridge, along with a surface low pressure system approaching the region from the west will bring gusty southwesterly winds and much above normal temperatures on Friday. Based on the GEFS mean, high on Friday could be a few degrees warmer. Near record highs could be possible. && .AVIATION...(For the 00Z TAFS through 00Z Saturday Evening) Issued at 619 PM CDT Fri Sep 18 2020 Terminals KABR,KATY,KPIR,KMBG VFR conditions are expected through the period. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...Wise SHORT TERM...Dorn LONG TERM...SD AVIATION...Wise
Area Forecast Discussion
National Weather Service Bismarck ND
935 PM CDT Fri Sep 18 2020 .UPDATE... Issued at 932 PM CDT Fri Sep 18 2020 So far visibilities holding steady this evening, a few spots down to 6 to 8 miles but otherwise nothing substantially low. A batch of stratus has developed in the southern James. Current sky cover grids cover this well. No changes needed with this update. UPDATE Issued at 633 PM CDT Fri Sep 18 2020 Widespread surface pressure falls this evening continued with warm southerly flow at the surface. Satellite imagery shows smoke filled skies aloft, mostly focused in the west through south- central. While surface visibility has been unaffected this afternoon, Beach AWOS visibility has recently dipped to 7 miles. Uncertainty remains in visibility trends over the next 3-6 hours with HRRR near-surface smoke fields clearing smoke a bit (possibly with the nocturnal surface inversion developing) while integrated smoke fields continue to push smoke aloft into our area. We`ll refrain from making any adjustments for now given uncertainty in how the inversion impacts near-surface smoke potential. && .SHORT TERM...(This afternoon through Saturday) Issued at 125 PM CDT Fri Sep 18 2020 An upper level ridge axis is currently located over central Montana, keeping all of western and central North Dakota in northwest flow aloft. This will keep the thickest smoke out of all areas except the far southwest through the rest of today and tonight. Expect hazy skies to continue through tonight with lows generally in the 40s. The ridge axis will reach the North Dakota border by around 12z Saturday and central North Dakota by around 21z. As the axis nudges closer, smoke aloft from western United States wildfires will once again increase through the day Saturday from west to east as the upper level flow turns more westerly and then southwesterly ahead of a potent negatively tilted trough. Most of the smoke should remain aloft, but may make its way down to the surface across the far west. Because of the smoke aloft, high temperatures will likely be lower than most guidance so we did adjust those values down a fair amount. Highs will range from the lower 70s east to the mid and upper 70s central and west. As a cold front approaches from Montana, breezy southeasterly winds will increase through the day with the strongest winds west and south. Sustained winds up to 20 mph with gusts up to 35 mph will be possible in these areas. With the front and best upper level forcing remaining in Montana through the day, expect dry weather through the afternoon. .LONG TERM...(Saturday night through Friday) Issued at 125 PM CDT Fri Sep 18 2020 The aforementioned negatively tilted trough and cold front will continue to approach the western Dakotas Saturday night. Chances for showers and a few thunderstorms return to the forecast after 00z across the far west, expanding east overnight with the best chances across the north. The global models continue to keep most of the precipitation west of the Montana border, but the longer range CAMs (and to some extent the 12z NAM) are more aggressive in bringing a broken line of showers and thunderstorms across nearly the entire state through the late morning/early afternoon hours on Sunday. Strong upper level Q-vector convergence and steep lapse rates along the front seem to support the potential of more widespread showers and storms than the global models suggest, but meager low level moisture and weak instability will likely limit the magnitude and coverage. SPC has placed most of the area in general thunder Saturday night and Sunday, but severe weather is not expected which seems reasonable given the meager instability. Behind the front expect more breezy conditions Sunday afternoon with winds out of the west. Regarding smoke, we may get a slight break on Sunday behind the front but the global models keep us generally in westerly flow aloft through midweek. Thus, hazy/smoky skies may be back to stay for a few days. The next chance for some showers and possibly a few thunderstorms looks to enter the forecast Tuesday night and Wednesday as another wave approaches. Global models are still a bit fuzzy on timing and specific details, but the consensus remains that we will not see widespread precipitation from this system, just more hit and miss showers and thunderstorms. Ridging once again builds towards the end of the period as a western United States trough begins to amplify and make its way towards the Northern Plains. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 633 PM CDT Fri Sep 18 2020 VFR conditions with hazy skies expected to continue through the TAF period. Smoke aloft will spread east into central North Dakota through Saturday. Not seeing a strong indication that this will translate to widespread surface visibility reductions at this time. Breezy southeasterly winds develop Saturday afternoon. A cold front will arrive in western North Dakota after 00Z, bringing chances for showers and possibly thunderstorms Saturday night. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AE SHORT TERM...ZH LONG TERM...ZH AVIATION...AE
Area Forecast Discussion
National Weather Service Charleston SC
1117 PM EDT Fri Sep 18 2020 .SYNOPSIS... Strong high pressure will gradually build into the area over the weekend and will persist through next week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Text and gridded products have been updated to remove the Coastal Flood Advisory. The inland wedge will strengthen overnight as the parent high bridges the central Appalachians and builds south through the Carolina Piedmont. A risk for patchy drizzle will linger a few more hours across the south. Overall, conditions will remain dry through the night. Lows will range from the mid 60s well inland to the lower 70s along the Georgia coast where onshore winds will moderate temperatures. Lake Winds: A Lake Wind Advisory has been posted for Lake Moultrie through noon Saturday. Winds are expected to increase into the 15-20 kt range with frequent gusts to 25 kt overnight into Saturday morning as strong mixing over the warm lake waters support strong mixing. H3R and RAP profiles support the highest winds over the central and southwest portions of the lake. Waves will build to 1-2 ft, highest central and southwest portions. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... Saturday through Monday: Strong surface high pressure centered over the Great Lakes region will gradually deepen as it propagates eastward. Surface ridging will continue to build over the weekend, with associated northeast flow eventually forming a wedge pattern. As surface winds veer to the northeast after the passage of the front, gusty winds will persist mainly along the coast due to a tightening pressure gradient. Wind gusts could approach Lake Wind Advisory criteria over Lake Moultrie this weekend; however, the current forecast caps gusts around 20 kt. Subsidence and a stable atmosphere should eliminate much precipitation from developing over land. Weak instability over the waters and deep moisture being advected from distant Hurricane Teddy calls for slight chance PoPs due to the potential for isolated showers developing. Strong northeast flow could push a shower onshore in southeast GA; however, it will likely be short-lived and light in nature. Model guidance hints at the greatest possibility for rain over McIntosh County where deeper moisture exists. PoPs are capped over this area near 20% considering the atmosphere is relatively stable. Much cooler temperatures are expected with high temps about 10 degrees below normal for this time in September. High temperatures Saturday through Monday should only reach the low to mid 70s, and min temps are forecast to drop below 60F inland with low to mid 60s closer to the coast. Additionally, noticeably lower dew points will make way for a drier, comfortable "autumn-like" setting. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A wedge of high pressure and drier air will prevail across the area through the middle of next week keeping rain chances to minimum. High temperatures will gradually increase through the week. Low temperatures could drop into the low 50s on Tuesday and Wednesday. By late week, low pressure could approach the area from the west and increase rain chances. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... Cigs are expected to mostly remain VFR through the period, although a brief period of MVFR and possibly some very light drizzle could impact the terminals this evening. A last minute TEMPO may be included just before release time pending trends. Extended Aviation Outlook: Brief MVFR conditions are possible in low clouds this weekend. VFR expected thereafter. && .MARINE... Tonight: Winds are steadily increasing across the waters this evening. Northeast winds 20-25 kt with gusts to 30 kt will be common overnight. Small Craft Advisories remain in force. Saturday through Wednesday: Strong ridging will continue to build over the waters further deteriorating marine conditions with gusty northeast winds around 25 kt, 6-7 foot seas entering the nearshore waters, and up to 10 foot seas in the outer waters on Saturday. Winds and seas will continue to gradually increase, following the strengthening pressure gradient as distant Hurricane Teddy moves north-northwest closer to strong surface high pressure. Seas could build up to 10 feet in the nearshore waters Sunday and up to 15 feet in the outer waters as wind gusts increase to near 35 knots. A slow downward trend in the wind gusts and seas will occur early next week; however, noticeable improvement in the marine conditions will not be until Wednesday. Small Craft Advisories are ongoing for all marine zones. The outer GA waters has been upgraded to a Gale Watch beginning 16Z Saturday. AMZ374 may need to be upgraded to a Gale Warning and the near shore waters may need to be upgraded to Gale Watches/Warnings. Rip Currents: A low risk of rip currents remains in the forecast for today and a moderate risk is forecast for Saturday. An elevated risk of rip currents is expected thereafter due to elevated northeast winds gradually increasing and incoming long period swell up to 16 seconds from distant Hurricane Teddy. In addition, building seas over the weekend could lead to high breakers at the beaches, 5 feet or greater late this weekend. High Surf Advisories could be needed along the beaches. Beach erosion could occur with the combined effects of high breakers and higher tidal levels. && .TIDES/COASTAL FLOODING... Significant coastal flooding is expected this weekend into early next week. The combination of astronomical forces, freshwater arriving from upstream, and gusty NE winds will result in flooding of both the AM and PM high tide cycles. PETSS guidance remains missing due to a scheduled outage. The extra- tropical guidance is suspected to be too low for the days 2-3 period. Based on the duration and strength of the wind field, departures over astronomical tides should increase Saturday into Sunday, the peak tide is forecast for Sunday morning. Peak water levels may reach the highest since the Thanksgiving 2018 event for both the SC and GA coasts. The combination of the AM/PM tides may result in 6-10 hours of water in excess of flood stage each day. Given the long duration of water above flood stage, it is possible that flooding may occur well upstream on rivers and creeks with tidal cycles. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...Lake Wind Advisory until noon EDT Saturday for SCZ045. MARINE...Small Craft Advisory until 8 PM EDT Tuesday for AMZ350-352. Small Craft Advisory until 3 AM EDT Wednesday for AMZ354. Gale Watch from Saturday afternoon through Monday morning for AMZ374. Small Craft Advisory until noon EDT Saturday for AMZ374. Small Craft Advisory until 8 PM EDT Monday for AMZ330. && $$
Area Forecast Discussion
National Weather Service Dodge City KS
441 PM CDT Fri Sep 18 2020 ...Updated Aviation... .SHORT TERM...(This evening through Saturday) Issued at 310 PM CDT Fri Sep 18 2020 Visible RGB satellite showing the smoky sky over, basically the entire region and high smoke concentration is focused around the 5000 ft level with lower concentration per HRRR smoke products toward the 1000 ft level, ahead of a surface trough from around Scott City to Dodge city and southeast. Warmest temperatures this afternoon were behind the surface trough where temperatures reached the low 80s by 2 pm, contrast to mid 70s on southeast surface winds ahead of the front. Marginally warmer overnight lows can be expected tonight, but still comfortable in the mid 50s most areas. .LONG TERM...(Saturday night through Friday) Issued at 310 PM CDT Fri Sep 18 2020 Little overall change to the going forecast in either the short or long term. We will develop a better boundary layer pressure gradient over the western half of Kansas which will result in more pronounced southwest/downslope flow for Saturday. This looks to push well into the upper 80s with winds sustained up near 20 knots or higher by the late morning. Both he EC and GFS20 show a weak trough and cold front influencing the area mid week, however it is not strong enough to change the overall pattern as warm temperatures extend well into the northern plains into late next week. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 441 PM CDT Fri Sep 18 2020 VFR/SKC will continue through this TAF cycle, along with continued modest visibility reductions in smoke/haze. MVFR visibility is not expected. Light S/SE winds near 10 kts are expected overnight. After 15z Sat, expect strong south winds to return to all airports, gusting 30-35 kts. The strongest south winds are expected at GCK Saturday midday/afternoon. && .PRELIMINARY POINT TEMPS/POPS... DDC 55 84 58 85 / 0 0 0 0 GCK 55 84 59 85 / 0 0 0 0 EHA 55 85 58 86 / 0 0 0 0 LBL 53 86 56 86 / 0 0 0 0 HYS 55 83 59 84 / 0 0 0 0 P28 54 80 54 80 / 0 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...Turner
Area Forecast Discussion
National Weather Service Des Moines IA
626 PM CDT Fri Sep 18 2020 ...Updated for 00z Aviation... .DISCUSSION.../Tonight through Friday/ Issued at 247 PM CDT Fri Sep 18 2020 General Summary... A quiet, generally comfortable forecast is on tap. Cool conditions will prevail today, slowly giving way to warmer temperatures through the weekend and early next week, back into the low to mid 80s. Breezy southerly winds will prevail over the weekend, especially Sunday when gusts could push 30 to 35+ mph over portions of wester/northwest Iowa. Precipitation chances will be very hard to come by as well, with only very low end chances in the forecast over far northern Iowa into Minnesota Sunday and Wednesday nights. Smoke from western wild fires also likely to linger overhead form now through early to middle of next week. A Bit More Detail... The seven day forecast is devoid of major concerns with regards to temperatures, winds, and precipitation. Instead, there are a few lower-end areas of concern. To begin with, upper level pattern across the western and central CONUS will continue to be conducive for smoke advection across the area. Currently, a closed upper low just entering the western Oregon coast will continue southerly mid and upper level flow over the main fire region, allowing smoke to ride overtop the ridge and down the northwest flow into the upper Mississippi Valley region. HRRR Smoke has shown a consistent trend for higher concentrations of smoke to pass overhead this weekend, resulting in continued and increased filtering of sunlight. Fortunately, the smoke should remain aloft, limiting any surface/near-surface issues. Synoptic guidance suggests relief from smoke aloft may not come until mid-late week when the upper level flow may keep some smoke west, but with fires ongoing in Oregon and Washington as well, we may be hard pressed to see truly clear skies. Main consequences revolve around reduced insolation and potential affects on temperatures including cooler highs, possibly slightly warmer lows. Have adjusted Saturday a degree or two in accordance with that line of thought. Away from smoke, the aforementioned upper level low entering the PNW will force amplified ridging in to the Plains, resulting in warming temperatures into the weekend and new work week. While smoke may temper highs a bit, high confidence in low to mid 80s returning as early as Sunday in western forecast areas and area wide during the early portions of the week. As this transition occurs, current surface high will slide off and surface low will build into the central and northern Rockies front range areas causing surface pressure gradient and winds to increase. Winds over the weekend may yield sustained 20+ mph and gusts pushing 35+ over the area, especially across the west on Sunday. As the parent upper level system slides across southern/central Canada late in the weekend, very low end precipitation chances may be seen in far northern Iowa along a weakening boundary. The trend in reducing POPs has continued and for the time being the Sunday night period is now dry. Broad upper level ridging/zonal flow will dominate early-mid week, keeping the region dry and pleasant. Flagship synoptic guidance remains in fair agreement on a shortwave trough moving through in the Wednesday evening/overnight time frame, bringing with it another chance for a few showers and a slight cool down. With the surface low anticipated to be along/near the Canadian border, the frontal passage, along with large surface dew point depressions, appears to be hard pressed to provide enough of a kick for much precipitation potential with best chances as you move northward into Minnesota. At this point cannot rule out an elevated shower or two though. Main discernible change more likely to be a brief one day switch from southerly winds to northerly winds and nominal few degree cool down. && .AVIATION.../For the 00Z TAFS through 00Z Saturday evening/ Issued at 626 PM CDT Fri Sep 18 2020 VFR conditions will persist through the TAF period. Winds will become southerly on Saturday and increase, gusting over 20 kts mainly over the western half of the state. Upper-level smoke will increase across portions of the state again on Saturday. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...Curtis AVIATION...Hagenhoff
Area Forecast Discussion
National Weather Service Quad Cities IA IL
510 PM CDT Fri Sep 18 2020 ...00Z AVIATION UPDATE... .SYNOPSIS... Issued at 216 PM CDT Fri Sep 18 2020 Quiet weather was in place across the area with high pressure centered across northern Wisconsin and far eastern Minnesota. Despite that, clouds were widespread with good vertical mixing and steep lapse rates aloft in the boundary layer. This was leading to cooler temperatures with values as of 2 PM ranging from 59 in Dubuque, to 69 in Independence. && .SHORT TERM...(This Evening through Saturday) ISSUED AT 216 PM CDT Fri Sep 18 2020 Key Message: 1) Below normal temperatures continue into the beginning of the weekend but with dry and quiet weather. Broken diurnal cloud cover should diminish through the evening with boundary layer decoupling, which should lead to clear skies over the area tonight. In addition, the surface high will make its way towards the Midwest, and is progged to be centered directly over Michigan by 12z Saturday. As a result, winds will become light and variable. All of this sets up what will likely be the coldest night of the season so far. Temperatures, especially closer to the high in northwest Illinois, will easily drop into the mid to upper 30s, especially in low-lying areas like river valleys. Several CAMs like the NAMnest and ARW hint at this strongly, and even show values nearing freezing in the Illinois River Valley in Putnam county. However, this likely overdoing a bit. Regardless, temperatures falling to this degree will lead to potential for development of patchy frost. The best chance for this will be in Stephenson county and into portions of Bureau and Putnam counties. Given the patchy nature, will not issue a frost advisory with this package. Saturday should see some good recovery in temperatures with CU rule procedures suggesting mostly sunny skies during the day as we lose moist northeast flow from Lake Michigan. Temperatures will be similar to today, with widespread afternoon highs in the mid to upper 60s. HRRR forecasts suggest another round of western CONUS wildfire smoke will likely overspread the area beginning in the evening, but should not be enough to influence afternoon highs. .LONG TERM...(Saturday Night through Friday) ISSUED AT 216 PM CDT Fri Sep 18 2020 Key Message: 1) Temperatures warming heading into next week; dry and quiet weather conditions continue. The high pressure will continue to influence our weather for much of the long term period. As it continues to move into the Northeast U.S., surface ridging should gradually expand to its south and west through early next week, with most guidance suggesting it reaching all the way down into northern Texas through at least Tuesday. This will be effective at keeping moisture from the Gulf of Mexico at bay even with the formation of what will likely be Beta over the next few days. Eventually, the surface high should begin to weaken with decreasing heights aloft and a breakdown of the upper level ridging. By mid to late next week, deterministic guidance including the GFS and ECMWF show a cold front moving across the area but differ w.r.t. precip chances. At the point the GFS is the most bullish while the ECMWF shows a weaker front. Given the low confidence have kept shower chances out with this package. Temperatures will end the weekend in the upper 60s to low 70s, and should begin to warm back into the 70s to near 80 for the remainder of the week with mainly zonal flow aloft. Lows should remain in the 50s. If we end up with more wildfire smoke overhead, this may act to lower temperatures slightly. Given these kinds of forecasts are only made in the short term, didn`t make any changes to values at this time. && .AVIATION...(For the 00Z TAFS through 00Z Saturday Evening) ISSUED AT 510 PM CDT Fri Sep 18 2020 VFR conditions are expected to dominate the TAF cycle, with a BKN cumulus deck gradually decreasing tonight with loss of heating and influx of drier air. If the clouds were to hang around longer than expected late tonight into Saturday AM, then would have low potential for high MVFR ceilings mainly near to west of DBQ to CID terminals. Another round of upper level smoke may move in Saturday. Light easterly winds tonight look to turn from south/southeast on Saturday and increase to around 10 kts with some localized higher gusts possible west of the Mississippi River in the afternoon. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...Speck SHORT TERM...Speck LONG TERM...Speck AVIATION...McClure
Area Forecast Discussion
National Weather Service Flagstaff AZ
820 PM MST Fri Sep 18 2020 .SYNOPSIS...Dry weather will persist over northern Arizona through Sunday. Expect breezy conditions today and Saturday, with the fastest winds near the Utah border. A slight chance of afternoon showers and thunderstorms returns to the Northland Monday through Wednesday next week. && .UPDATE...Minor updates were made this evening to overnight low temperatures. Otherwise, forecast remains on track for another cool and calm night across northern Arizona. Expect more breezy southwest winds to return tomorrow afternoon, mainly across western Arizona. As mentioned by the day shift, we may see an increase in haze from the west coast wildfires with this southwest flow as well. However, this will largely be lofted high in the atmosphere. && .PREV DISCUSSION /319 PM MST/...A dry and warm day has developed across northern Arizona. Southwesterly flow aloft has increased and will continue to increase through Saturday in advance of a trough moving through the Great Basin to our north. This will be a dry trough passage for Arizona but will continue to bring breezy southwest winds through Saturday. Winds will be strongest on Saturday afternoon when gusts reach up to 25 to 35 mph across western Arizona. In addition, the trough will result in a decrease in daytime temperatures over the weekend but they will still remain above normal. The HRRR Smoke model shows indications that the increasing southwest flow may lead to increased smoke/haze Saturday. Next week looks to remain mostly dry with temperatures running close to or just slightly above average. Early in the week, southeasterly flow aloft develops and begins to draw moisture northward along the Colorado River. We may see just enough of an increase in moisture for a few afternoon instability showers to develop. We will carry a low chance for showers in the forecast next week, mostly favoring the mountains along and north of the Mogollon Rim. We are not expecting appreciable rainfall. Another dry trough passage with increased winds is possible late next week. && .AVIATION...For the 06Z package...VFR conditions through the forecast period. Southwest winds will increase again Saturday with afternoon gusts 20-25kts west of a line from KPRC-KFLG-KGCN. Areas of smoke and haze will be possible from west coast fires , though remaining mostly elevated. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Saturday...breezy south to southwest winds across northwestern Arizona, with calm to light winds on Sunday. Temperatures will run slightly above normal. Monday through Tuesday... Isolated thunderstorms with lightning and gusty winds possible Monday afternoon especially north/west of Flagstaff. Temperatures remain slightly above average with light southwest winds Tuesday/Wednesday. Critical fire weather thresholds are not expected through the period. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...ET/MCT AVIATION...ET FIRE WEATHER...MCT For Northern Arizona weather information visit
Area Forecast Discussion...CORRECTED
National Weather Service Hanford CA
455 PM PDT Fri Sep 18 2020 Updated for air quality section .SYNOPSIS...Increased southwest winds will bring gusty conditions over the higher elevations of the Sierra Nevada this evening. Daytime temperatures will remain below average on Saturday then rise to slightly above average by early next week. Dry conditions will prevail tonight through next week. && .DISCUSSION...Upper trough now pushing through CA brought increased mid/high clouds to our area today as it pulled up some moisture from the remnants of what was Tropical Depression Karina. The trough has also brought cooler temperatures to our area aside from the Kern County Desert areas today. Several stations in the Sierra Nevada and adjacent foothills from Fresno County northward picked up some light rainfall earlier today with amounts generally a tenth of an inch or less. in addition, trace amounts were reported at some stations in the San Joaquin Valley. HRRR indicating sprinkles or a few light showers are still possible in the Sierra Nevada through early this evening. As the trough continues to push through our area tonight, a period of gusty southwest winds are possible over the higher elevations of the Sierra Nevada which could pose challenges to fire suppression efforts. The trough has provided for better mixing conditions which have resulted in improved visibility over the San Joaquin Valley and Sierra foothills today. By Saturday, the trough will move to the east leaving central CA under a dry northwest flow which will result in clearing skies, and cooler than normal temperatures across our area. A weak ridge is progged to build into CA on Sunday which will result in a dry weather and a warming trend on Sunday and Monday with daytime temperatures rising to slightly above normal levels across our area by Monday. The medium range models are in good overall agreement for the remainder of next week with the ridge being flattened on Tuesday by a weak system pushing through the PAC NW then rebuilding on Wednesday and Thursday before a stronger system moves through the PAC NW next Friday. Temperatures will remain slightly above seasonal normals for much of next week until lowering to near normal on Friday. With the moisture and dynamics from these systems remaining well to the north of our area, mainly clear skies and dry conditions will prevail next week. However, with light winds expected to prevail for much of next week, wildfire smoke could impact the area once again next week with lower visibility and slightly lower daytime temperatures. && .AVIATION...Over the Sierra Nevada range, areas of mountain obscuring IFR conditions due to clouds and showers over the Sierra Nevada until 03Z Sat. Otherwise areas of MVFR visibility and local IFR visibility due to smoke will continue for the next 24 hours. Elsewhere across the central CA interior, local MVFR visibility due to smoke and haze will continue for the next 24 hours. && .AIR QUALITY ISSUES... Please see SFOAQAHNX for an Air Quality Alert On Saturday September 19 2020... Unhealthy for sensitive groups in Kern and Tulare Counties. Very unhealthy in Sequoia National Park and Forest. && .CERTAINTY... The level of certainty for days 1 and 2 is medium. The level of certainty for days 3 through 7 is medium. Certainty levels include low...medium...and high. Please visit for additional information an/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES...None. && $$ public...DS aviation....DS
Area Forecast Discussion
National Weather Service Wichita KS
1031 PM CDT Fri Sep 18 2020 .SYNOPSIS... Issued at 305 PM CDT Fri Sep 18 2020 In the overall pattern, a trough is making its way onshore along the West Coast while a ridge sits over the Rockies and another trough stretches from Hudson Bay through the East Coast. There is a tropical depression in the western portions of the Gulf of Mexico which is tracked to work its way north then west towards the Texas coast early next week. A plethora of fires along and west of the Rockies continue to bring smoke plumes/haze into the Plains. Afternoon temperatures range from the upper 70s to lower 80s with variable winds at 5 to 10 mph. && .SHORT TERM...(This evening through Monday night) Issued at 305 PM CDT Fri Sep 18 2020 Highlights: 1) Haze/smoke possibly into Sunday 2) Highs in upper 70s to lower 80s Another day of hazy skies due to the smoke from the fires in the Rockies and westward was the story for the Central Plains today. Thankfully there were minimal if any visibility restrictions as it was more elevated than surface based. According to the latest experimental HRRR-smoke model and RAP-smoke model, the smoke/haze is expected to continue potentially even through Sunday. The RAP hints of an increase mid morning on Saturday and into Sunday for the central and western thirds of Kansas. This could mean a thicker layer of haze in the sky or the return of possible visibility restrictions. Anyone with breathing issues or other sensitivities to smoke should consider staying indoors. A trough is moving over the West Coast and should track to the east/northeast through the weekend which will push the northern portions of the ridge east as well. The center of the low pressure system is still on target for movement across south central Canada on Sunday. Winds are anticipated to pick up and be breezy during the afternoon hours of Saturday and Sunday primarily west of a line from Hutchinson to Salina. Temperatures are forecast to stay in the upper 70s to lower 80s for this period. Only minor tweaks were made to the ongoing forecast as it was still representative of the expectations. .LONG TERM...(Tuesday through Friday) Issued at 305 PM CDT Fri Sep 18 2020 Highlight: Highs around 80 with lows in the mid 50s A shortwave is still progged to cross the Northern Plains Tuesday night into Wednesday. High pressure should follow in for Thursday. The forecast remains dry for the next seven days for now. Temperatures are forecast to stay near the seasonal normal range with highs around 80 and lows in the mid 50s. It will definitely be pretty nice for anyone wanting to enjoy outdoor activities or work on fall chores. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) Issued at 1029 PM CDT Fri Sep 18 2020 VFR conditions will prevail for the next 24hrs across the region as surface high pressure drifts slowly eastward. Southeast winds will switch to the south and increase during the afternoon hours. && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 55 80 55 79 / 0 0 0 0 Hutchinson 53 81 55 79 / 0 0 0 0 Newton 53 79 54 79 / 0 0 0 0 ElDorado 53 79 54 78 / 0 0 0 0 Winfield-KWLD 55 80 54 79 / 0 0 0 0 Russell 55 82 60 84 / 0 0 0 0 Great Bend 54 81 58 81 / 0 0 0 0 Salina 54 81 58 83 / 0 0 0 0 McPherson 53 80 55 80 / 0 0 0 0 Coffeyville 53 78 51 79 / 0 0 0 0 Chanute 53 77 51 79 / 0 0 0 0 Iola 52 77 51 80 / 0 0 0 0 Parsons-KPPF 53 77 51 79 / 0 0 0 0 && .ICT WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...VJP SHORT TERM...VJP LONG TERM...VJP AVIATION...CDJ
Area Forecast Discussion
National Weather Service Memphis TN
856 PM CDT Fri Sep 18 2020 .DISCUSSION...A ridge of high pressure centered over the Great Lakes Region continues to bring mostly clear skies to much of the Mid-South with the exception of some high clouds over Mississippi associated with an upper level jet streak moving across the Lower Mississippi Valley. As of 8 PM CDT, temperatures across the Mid- South are in the 60s at most locations. Adjusted temperatures down slightly to account for short term trends. Otherwise, no other changes made to the remainder of tonight`s forecast. CJC && .PREV DISCUSSION... /issued 630 PM CDT Fri Sep 18 2020/ UPDATE... Aviation Update Below PREV DISCUSSION... /issued 330 PM CDT Fri Sep 18 2020/ DISCUSSION... A pleasant afternoon ongoing across the Mid-South. Temperatures are currently in the mid to upper 70s under mostly clear, albeit hazy skies. Latest GOES CIMSS Natural Color imagery shows thick wildfire smoke filtering into the Mid-South from the northwest with high cirrus spilling into northeast Mississippi. Brisk northwest winds will continue to usher in an even drier airmass late tonight. Expect lows to fall into the low to mid 50s areawide, with a few low lying areas briefly touching the 40s by tomorrow morning. Surface high pressure will remain in place through at least early next week. This will lead to a string of several pleasant days across the Mid-South. Expect highs in the 70s with lows in the 50s each morning. Latest HRRR model shows smoke finally exiting the Mid-South by late tomorrow afternoon as the jet stream retreats northward. Thereafter, we should see the return of blue skies through early next week. Models are now latching onto what is now Tropical Storm Beta. It appears that TS Beta will stay in close proximity to the Texas Gulf Coast through early next week and will produce copious amounts of rainfall. Models suggest that it will get picked up by a subtropical shortwave by the middle of next week and lift through the Lower Mississippi Valley. Lots of uncertainty still remains on how far north the remnants will move and its effects on the Mid-South. Went with a blend for now, keeping low POPs across north Mississippi through late next week. Stay tuned. AC3 && .AVIATION... 00Z TAF VFR conditions through the TAF cycle at all sites. NNE winds 8-15kts. Will get gusty again tomorrow afternoon with gusts 15-20kt range. SMW && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion
National Weather Service Spokane WA
231 PM PDT Fri Sep 18 2020 .SYNOPSIS... Smoke will persist across our region through Saturday morning, then anticipate improving conditions. The arrival of a cold front will bring showers and westerly winds. Not only will the front bring showers to the Inland Northwest, but it should provide essential rains to the Oregon wildfires. Drier and seasonal weather under smoke free skies is forecast for Sunday through Tuesday, then warmer and showery weather is forecast by mid week. && .DISCUSSION... Tonight through Sunday Night: The air quality has made little regionwide improvement today. However, the approaching weather system has been bringing significant improvements to coastal air quality. The change in winds and rain will assist in the removal of the smoke and poor air quality. By Sunday, we are anticipating most smoke removed. The Air Quality Alert will continue through tomorrow morning. The incoming low is bringing a break in the high pressure & it`s dry and smoky air. The bands of wetting rain have been moving across the western side of Washington and Oregon today. They are slowly making their way into the Cascades late this afternoon. Rain will be widespread tonight and further east tomorrow. With this system, we will receive much needed precipitation. From tonight into tomorrow, there will be widespread rainfall, with the chance for isolated heavy downpours. The 36 hour rain total will range anywhere from 0.02" in the Basin and up to 0.5" - 0.75" in the northern WA mountains, Cascades, and Idaho Panhandle. The much needed moisture will be helpful with some current fires. However, the numerous burn scars are going to be very sensitive to even a brief heavy downpour, which may create debris flow. There is not generous instability with this system, but there is potential for isolated thunderstorms in the Cascades tonight and northern mountain on Saturday. The Blues and far southeastern Washington has the potential for a few pop up cells with lightning overnight tonight with the heavier rainfall. There is a slight chance and we are low in confidence. Many locations are still quite dry and lightning could easily spark a fire. Winds will be breezy tomorrow, with potential gusts up to 20-30 mph, widespread in eastern Washington. The HRRR is hinting at a gusty outflow with the arrival of the showers, but the smoke coverage could prevent this and many models are not in agreement. If so, these winds would be isolated and monitored if they are by fires. Sunday winds will be light, accompanied by remnant rain in the far eastern Panhandle. Temperatures tomorrow and Sunday will be cooler in seasonal normals, with highs in the upper 60s and 70s. Lows cool back into the 40s Saturday and Sunday night. JS Monday through Friday: The work week will start off on the dry side but becoming wetter by the end of the week and feeling more fall like. A southwesterly flow aloft will be over the Inland NW for Monday and Tuesday. Aside from some spotty showers near the Cascade crest on Monday, it should be a dry period through Tuesday night. Residual low level moisture will give way to patchy morning fog in the northern valleys. Temperatures will be slightly above normal with daytime highs in the 70s and lows spanning the 40s to lower 50s. Winds will be light with occasional westerly breezes in the afternoon and early evening. Meanwhile, a Pacific low will be swinging from the Gulf of AK toward the WA coast. A slow moving frontal boundary will sag across the region, reaching the Cascades Wednesday morning and then shifting across the Columbia Basin and into the northern mountains Wednesday night into Thursday night. Showers will linger into Friday with a broad upper trough over the region. The best chance for measurable rains look to be across the higher terrain, while lighter rainfall will stretch across the Basin. Temperatures will warm slightly ahead of the cold front, although by Friday temperatures cool to below normal. Southwesterly winds will increase late Wednesday and continue through Friday with higher gusts possible by Friday. A benefit of the wetter and breezier pattern should keep smoke levels limited from the region. /rfox && .AVIATION... 00Z TAFS: Smoke will continue to impact TAF sites with reduced visibility and ceilings. They are expected to fluctuate between IFR and MVFR conditions through the TAF period. The incoming frontal system tonight and tomorrow will bring chances of showers at the TAF sites and will help clear out some of the smoke. There is a slight chance for lightning at KEAT and KLWS tonight from 00z to 12Z. JS && .PRELIMINARY POINT TEMPS/POPS... Spokane 50 70 46 71 45 74 / 40 30 20 0 0 0 Coeur d`Alene 52 68 47 69 45 74 / 50 40 40 10 0 0 Pullman 48 67 43 70 42 73 / 60 50 10 0 0 0 Lewiston 57 74 53 76 51 79 / 60 40 10 0 0 0 Colville 47 72 41 73 39 75 / 30 50 40 10 0 10 Sandpoint 50 66 45 66 41 71 / 50 60 60 20 10 0 Kellogg 55 64 52 66 48 73 / 60 70 50 20 0 0 Moses Lake 49 76 46 76 46 75 / 30 20 0 0 0 0 Wenatchee 57 73 54 75 53 74 / 60 20 10 0 0 0 Omak 55 76 48 75 48 74 / 50 30 10 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
Area Forecast Discussion...UPDATED
National Weather Service Reno NV
534 PM PDT Fri Sep 18 2020 .UPDATE... Most of the Red Flag Warnings were cancelled early due to much higher humidities and only marginal wind speeds, especially for Mono-Mineral counties and west central NV which received light amounts of rain. Lightning strikes were occurring east of US-95 with the shower activity, which produced up to 0.20" of rainfall in some locations. These thunderstorms will exit Pershing, Churchill and Mineral counties by 6 pm. The only areas where Red Flag Warnings were retained through 8 pm are the western NV Sierra Front and eastern Lassen County (Fire zones 420 and 278). In these areas the humidity is still marginally dry in the 15-20% range with wind gusts around 30 mph, while some wind prone areas were reporting 35-40 mph gusts. Conditions in these areas should improve after sunset. MJD && .SYNOPSIS... Smoke from wildfires will continue to impact the region, although some areas not downwind of fires should see improvement through at least Saturday. A cold front making its way through the region today will bringing cooler temperatures through Saturday, followed by some warming on Sunday. Slightly above average temperatures and dry conditions are expected through much of next week. && .PREVIOUS DISCUSSION... /Issued 134 PM PDT Fri Sep 18 2020/ SYNOPSIS... Smoke from wildfires will continue to impact the region, although some areas not downwind of fires should see improvement through at least Saturday. A cold front making its way through the region today will bringing cooler temperatures through Saturday. Warming to slightly above average Sunday is expected to persist through next week with highs generally in the 70s and 80s for valleys. SHORT TERM... Low pressure centered near the central Oregon coast will progress into the interior Pac NW and northern Rockies by Saturday afternoon. A moisture plume from the subtropical Pacific west of Baja California picked up by the incoming low combined with orographic ascent in the Sierra to bring between a few hundredths and ~0.15" of rainfall to the Sierra. For western and west-central NV, the moisture plume has encountered broad upper forcing and instability ahead of the incoming low. This has initiated isolated showers with rainfall generally between a trace and a few hundredths, except east of the Carson Sink where between 0.10" and 0.15" has been reported by automated stations. Any showers should dissipate by this evening as the moisture plume and best forcing exits into central and northeast NV. Winds have picked up this afternoon as cooler air with the incoming trough axis clashes with warmer antecedent air. Gusts have been fairly modest for this area of the country with 20-35 mph noted so far today for valleys and slopes and 40-60 mph over Sierra ridges. Winds should peak in the next few hours with gusts up to 40 mph or so below ridges, and up to 60-80 mph over exposed Sierra ridges. Humidities are way up today, mostly above 20% (higher still in the moisture plume); however, winds in some areas are strong enough that some fire danger remains. See the fire discussion for more. The increased mixing from winds has brought much better air quality to many areas, with the exception of the southern half of Mono County where the Creek Fire continues to plague that area (as it is directly downwind of the fire). There may also be some pockets of poor air quality left out in the Carson Sink although visibility has improved in Fallon recently so air quality may be improving there as well. The main forecast concerns tonight through Sunday night will be the broken record that is smoke along with temperatures, mainly for lows in the Sierra and coldest lower valleys for the next couple nights. HRRR smoke forecasts bring more smoke tonight into areas well north of Reno-Sparks, into the Carson Sink, and across Mono and Mineral counties with prevailing SW-W flow bringing additional particulates from the North Complex and Creek fires. Later Saturday and Saturday night, some smoke may drift into far western NV once again as low-level flow turns light easterly. If you have seen smoke clear out in your area, enjoy it while you can! As for low temperatures, freezing temperatures are likely in many Sierra valleys this weekend, at least for a few hours early in the morning, with the very coldest lower valleys possibly seeing some frost. The best shot may be tomorrow night as it may remain a bit mixed up tonight as the trough axis moves overhead. In any case, watch your local forecast and give it a few degrees of leeway on the lower side (forecast error combined with colder temperatures near the ground below where official air temperatures are read) if you have sensitive plants or exposed water lines to protect. -Snyder LONG week... The weather pattern looks mildly active with one or two passing shortwave troughs (around Monday and late Thursday/Friday) possible. On and off breezy southwest-west winds are possible during this time with dry conditions in place. Temperatures look to remain above average (peaking Wed-Thu) through at least Thursday before possibly easing down next Friday and Saturday. There is about a 10-degree range in possible highs next Friday and Saturday...going with blended forecast guidance is best for now but keep in mind the actual high may wind up around 5 degrees warmer or cooler. The second trough next week could also bring light rain north of Susanville and Gerlach and likely just breezes south of there. -Snyder AVIATION... Gusty winds this afternoon into the evening, mainly to 25-30 kts but locally to around 35 kts for valleys, will decrease tonight as a front moves through and a weak surface high settles into the area. With ridge winds gusting ~40-50 kts into the evening, turbulence over and downwind of ridges/peaks is a good bet. Modest high pressure moves overhead for much lighter north-east winds over the weekend along with VFR conditions (outside of morning fog potential in the Martis Valley near KTRK, especially by Sunday morning). Smoke-wise, there looks to be at least a brief reprieve through Saturday for many areas not directly downwind of major California fires; however, a general light haze (possibly affecting slantwise vis some) remains possible due to the shear amount of smoke being generated to the west. Areas that remain under the gun for lowered visibility in smoke are Mono and Mineral counties (Creek Fire), as well as across Plumas/southern Lassen counties eastward to Pershing and Churchill counties (North Complex fires). This is likely to affect KMMH the worst but could also bring a return to degraded visibility for KLOL/KNFL tonight into Saturday morning. -Snyder FIRE WEATHER... Not exactly your classic Red Flag situation out there. Mainly a low- end event but still plenty of wind with gusts 30+ mph in many areas. However a band of tropical moisture has resulted in light showers and higher humidity across a good part of the CWA. Afternoon RH`s even up into the 60s/70s in spots of W Nevada and the E Sierra. Even so the precip is for the most part not a wetting rain and vegetation is quite dry, so erratic wind-driven fire behaviour remains possible into early evening. Winds will continue strong on the ridges and mid- slopes until about midnight and then settle as upper jet moves off to the east. Light and variable winds for the most part this weekend, ranging from east/northeasterly over most areas to sneaky afternoon southwesterly breezes along the Sierra crest. Could see some isolated spots of critical conditions Monday afternoon as upper shortwave kicks up the winds slightly, but most ECMWF EPS members keep us below warning levels. -Chris && .REV Watches/Warnings/Advisories... NV...Red Flag Warning until 8 PM PDT this evening NVZ420. Lake Wind Advisory until 8 PM PDT this evening for Lake Tahoe in NVZ002. Lake Wind Advisory until 8 PM PDT this evening for Pyramid Lake in NVZ004. CA...Red Flag Warning until 8 PM PDT this evening CAZ278. Lake Wind Advisory until 8 PM PDT this evening for Lake Tahoe in CAZ072. && $$ For more information from the National Weather Service visit...
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
826 PM EDT Fri Sep 18 2020 .UPDATE... It has been a fairly quiet evening with sporadic showers and storms confined to southwest Florida with most of the other counties staying rain-free. Fair conditions will continue through the night with light winds expected. The trough that has been over the region will pull away to the east, allowing for some drier air and decreasing rain chances to settle over the region on Saturday. This is already evident in the 00Z evening sounding with a PWAT 1.96 inches, which is a half inch lower than 24 hours ago. Rain chances tomorrow will top out in the 20-40 percent range with seasonal daytime highs in the upper 80s. Made a minor tweak to POPs removing all mention of rain overnight to coincide with latest radar imagery and HRRR model guidance. && .AVIATION... VFR conditions will prevail with light winds less than 10 knots through tomorrow morning. Onshore flow is expected Saturday afternoon with the west coast sea breeze remaining less than 10 knots. Scattered showers and storms are possible from 18-00Z so will hold VCTS at all terminals during that time. No other aviation impacts expected. && .MARINE... Light northwest through northeast winds around 8-12 knots and minimal rain chances expected overnight and on Saturday. The gradient tightens between strong high pressure to the north and Tropical Storm Beta over the west Gulf of Mexico starting late Saturday. This will produce increasing northeast winds with SCEC or possibly SCA conditions beginning Saturday night and continuing into next week. In addition to building seas with increasing winds, a long period westerly swell propagating from Tropical Storm Beta can be expected into next week. && .Preliminary Point Temps/PoPs... TPA 74 89 75 88 / 0 30 20 40 FMY 76 91 75 90 / 10 30 10 70 GIF 73 90 75 87 / 0 50 30 50 SRQ 74 89 75 90 / 10 20 20 50 BKV 72 89 73 86 / 0 40 20 30 SPG 76 89 75 89 / 0 20 20 40 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...None. Gulf waters...None. && $$ UPDATE/AVIATION/MARINE...74/Wynn UPPER AIR/DECISION SUPPORT...29/Delerme