Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/12/18

Area Forecast Discussion
National Weather Service Albuquerque NM
544 PM MDT Sat Aug 11 2018 .AVIATION... 00Z TAF CYCLE Storms today have formed over southeast NM as well as over the central mtn chain up to the southern Sangre`s. Storms have for the most part fallen apart rather quickly once moving W-SW off the mtns. Locales down the RGV including KSKX, KSAF, KABQ, and KONM will continue to see a chance for VCSH with an isold embedded TS moving by for the next 2-3 hours. Elsewhere, an outflow bdry has washed up to the Sacramento Mtns leaving behind a cold pool with -RA and VCSH over the southeast plains up to the central highlands and KLVS. These will gradually diminish with overhanging cirrus burning off by late evening to near midnight. The HRRR and RAP13 have also been showing a quick isold TS forming off the CO San Juans moving down into NM, which will likely kick off some gusty outflow winds to KFMN. Given the convection seen on visible satellite up that way, have been inclined to believe this outcome and included a period of gusts up to 20-30kts at KFMN from 01Z-04Z. 24 && .PREV DISCUSSION...252 PM MDT Sat Aug 11 2018... .SYNOPSIS... Dry air moving across northern New Mexico is leading to a downtick in storms there today, but plenty of moisture remains across the southern half where storms got an early start and are capable of producing locally heavy downpours. Look for more of the same Sunday, although with an uptick in storm coverage across northern New Mexico. High pressure will strengthen over the state early to mid week, with high temperature trending back to slightly above normal by Tuesday or Wednesday. Look for a resurgence of storms late next week as high pressure moves out of the state and allows moisture to trend up. && .DISCUSSION... Today`s crop of storms got off to an early start thanks to a higher PWAT atmosphere across southern New Mexico and disorganized low pressure aloft stretching from southeast Arizona east into Oklahoma. The lack of storms across northern New Mexico is due to dry air rotating southwest across the upper high circulation. Locally heavy rainfall will continue to be a threat across south central and southeast New Mexico through the afternoon and into the early evening hours prior to the loss of daytime heating. The disorganized area of low pressure aloft will tighten into an upper low over the Texas panhandle and the eastern plains of New Mexico overnight into Sunday. Look for an uptick in storms across northern portions of the state Sunday afternoon/evening, as PWATs trend up some. Otherwise, Sunday should be similar to today. The story for early to mid next week involves the upper low pulling northeast away from the state as the upper high slides south over Arizona, then east over New Mexico by Wednesday. This will cause temperatures to trend back up to above normal by a degree or two most areas by Tuesday or Wednesday. PWATs are forecast to trend up from mid to late week as high pressure loses it`s grip on the state and a new high center builds over CA/NV. Look for an uptick in storms next Thu/Fri, with a downtrend in daytime temperatures thanks to the added cloud cover and rain-cooling. 11 && .FIRE WEATHER... No critical fire weather conditions anticipated for the next 7 days. Overnight humidity recoveries will be generally good to excellent. Some areas of poor vent rates forecast over central New Mexico Sunday and again Tuesday with poor rates becoming more widespread mid to late next week. Cell motion through Sunday most likely from the northeast and east to the southwest and west as a weak upper low pressure system wobbles around eastern New Mexico/West Texas and the upper high center lingers over the Great Basin. Areas south of Interstate 40 are favored for wetting convection for the rest of this afternoon and tonight, while Sunday appears to be most active across the northwest third to half of the forecast area. Locally heavy rain is possible. High temperatures will remain mostly below average. The weak upper low is forecast to lift to the northeast of New Mexico Monday as the upper high center drifts back over Arizona and New Mexico. High temperatures will warm a few degrees early to mid next week, but don`t stray too far from normal. Cell motion Monday looks to be more north to south. The higher terrain may be favored for wetting storms early to mid week, with storms drifting into the valleys in the late afternoons and evenings. Late next week the upper high center reestablishes over Utah and Nevada, leaving eastern New Mexico vulnerable to occasional fronts from the north. Thunderstorms should be most active over the central and east under this regime. Temperatures will be within a few degrees of average. && .ABQ WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service La Crosse WI
626 PM CDT Sat Aug 11 2018 .SHORT TERM...(This evening through Sunday) Issued at 321 PM CDT Sat Aug 11 2018 At 3 PM, the GOES 16 0.64 micron red visible band was showing that much of the smoke was located across western Minnesota and western Iowa. The 11.12z HRRR experimental total smoke product shows that the greatest amount of smoke will remain across northwest Minnesota tonight. With its surface smoke product showing very low concentrations and the pollution sensors only reporting 50 to 80 parts (moderate air quality) per million of particulates, opted to remove the mention of smoke in the forecast. Further to the east across central and east-central Wisconsin, there was a band of showers and storms. This precipitation is develop along the same boundary that was over our area on Friday afternoon. The 925-850 mb moisture convergence is being enhanced by a short wave move southeast through Lower Michigan and eastern Wisconsin. With the HRRR continuing to show an isolated shower and storm may make it as far west as Juneau and Adams counties late this afternoon and early evening, kept a 20 percent chance in those counties for this time period. However, with this said, would not be overly shocked that these counties remain dry. For late tonight and early Sunday morning, the models soundings show that the depth of the light winds are even greater (up to 650 mb) than what they were this morning (up to 800 mb). Like last night, we will still be battling a bit of dry air near the surface. Due to this, went with the greatest concentration of valley fog in the Mississippi tributaries and Wisconsin River valley. There will be some valley fog in the Mississippi channel too, but it looks more to be areas than widespread. On Sunday, 925 mb temperatures are fairly similar to this afternoon. However, the influence of the smoke from the western Canadian forest fires looks less. As a result, went about 1 to 3F warmer than today. .LONG TERM...(Sunday night through Saturday) Issued at 321 PM CDT Sat Aug 11 2018 500 hPa ridging continues across the forecast area Sunday into Monday resulting in mostly sunny/clear skies and dry conditions. With 925 hPa temperatures from 23 to 24 Celsius, it will be seasonably warm with daily highs in the mid 80s to lower 90s. The next best chance for showers and storms will be Tuesday into Wednesday as a Canadian trough drags a cold front across the region. Strongest deep layer shear is north of the international border, but some energy from a weakening Central Plains cut-off low could be ingested into the broader trough and provide additional lift for convective development. Even so, severe potential is low and POPs are still somewhat dependent on whether the northern stream wave and southern stream cut-off low can merge. Still another short-wave moves through weak quasi-zonal flow and across the region late Wednesday into Thursday for additional shower and storm chances. Forecast predictability really falls off the latter half of next week as medium range models continue to struggle with weak flow across the CONUS. Low-end consensus POPs seem reasonable at this time. Temperatures still look to cool down a bit Wednesday through the rest of the week in the wake of Tuesday night`s cold front. Daily highs will drop into the 70s to lower 80s for this period. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 626 PM CDT Sat Aug 11 2018 Main concerns this taf period are the smoke layers from the western NOAM wildfires and the late night/early morning BR/FG centered around 12z Sun. Northerly winds aloft will continue to spread smoke southward into the region, however the thickest of the smoke is progged to remain west of the TAF sites and not impact sfc vsbys. Smoke at the taf sites looking to be limited to semi-opaque layers in the 15K-25K ft range. Otherwise, clouds this period limited to few/sct diurnal cumulus Sun afternoon. Another favorable night/set-up for radiational valley fog formation. BR/FG again expected to develop in the MS river valley and be in/around the KLSE area in the 10-14z time-frame. Carried a tempo 11- 14z period of IFR cigs/vsbys in BR at KLSE. However BR/FG can be fickle at the KLSE ASOS site, as nuances of late night valley drainage winds determine where the BR/FG `sloshes` around the valley and if it will be observed by ASOS or not. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...Boyne LONG TERM...Rogers AVIATION...RRS
Area Forecast Discussion
National Weather Service Dodge City KS
500 PM CDT Sat Aug 11 2018 ...Updated Aviation... .SHORT TERM...(This evening through Sunday) Issued at 346 PM CDT Sat Aug 11 2018 The afternoon water vapor satellite and RAP analysis revealed expansive mid-upper tropospheric ridging across the bulk of the Rockies through the Northern Plains. Southwestern Kansas found itself in northeasterly flow aloft to the south of the ridge axis. As evident by the hazy sky across western Kansas, this flow regime allowed California wildfire smoke to round the ridge and continue southwestward into Kansas. The GOES-16 Blue Visible Band shows the smoke very nice in low light of morning and evening. A mid level cyclonic shear axis extended across New Mexico into North Texas and Oklahoma, which fostered thunderstorm activity in this region where deep tropospheric moisture was much greater. This remained far enough south such as not to influence sensible weather across western Kansas. This will continue to be the case through Sunday, although this will change after that. This will be discussed further in the Long Term section. Otherwise, a continuation of light easterly winds is expected with lows in the lower to mid 60s and highs around 90 on Sunday. .LONG TERM...(Sunday night through Saturday) Issued at 346 PM CDT Sat Aug 11 2018 The mid level shear axis across the Southern Plains, as first mentioned in the Short Term section, will work its way slowly north approaching southern Kansas. In doing so, it will bring much more abundant deep tropospheric moisture, leading to greater chances for thunderstorms. The first area to see convection will be south central Kansas as early as Sunday Night, but will only carry 20-30 POPs initially, primarily Comanche-Barber-Pratt counties. On Monday, the POPs will expand north and westward in the grids, with "Chance" POPs 25-40 percent in a corridor from Liberal to Garden to Wakeeney with 50-60 POPs east of a line from Ashland to Larned. The expected numerous shower and thunderstorm activity should keep temperatures at bay with highs generally in the lower 80s. It is possible it may not escape the upper 70s in some spots, but for now highs in south central KS will be forecast 82-83F. Fairly high POPs will continue all the way through Monday Night into Tuesday in these same general regions as a 700mb circulation center migrates slowly north across Kansas. The ECMWF is a bit farther west with higher QPF amounts, and if the GFS and eventual short-term high resolution models catch on to this, then "Likely" POPs will need to be expanded westward. If the ECMWF solution pans out, much of the region could see an inch or more of rainfall from this event Monday through Tuesday Night. The mid level feature responsible for this precipitation event will finally push east Tuesday Night-Wednesday with weak ridging replacing it. Eventually, though, western Kansas will become under the influence of perturbed northwest flow aloft later in the week for precipitation chances increasing again by Thursday Night. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 500 PM CDT Sat Aug 11 2018 VFR will continue through Sunday. That said, there will be some reductions in visibility (particularly slantwise visibility) due to smoke plumes arriving in weak NE flow aloft. Other than smoke and haze, SKC is expected tonight. NE winds gusting near 20 kts at DDC/GCK late this afternoon will subside quickly this evening, with light and variable winds overnight. After 15z Sun, a cumulus field will begin to develop, becoming most pronounced/broken SE of the terminals Sunday afternoon. No showers and thunderstorms are expected at the airports through this TAF period, but scattered rain showers and convection are expected on Monday. After 18z Sun, SE winds will increase to 10-20 kts at DDC, GCK and LBL, with lighter SE winds at HYS. && .PRELIMINARY POINT TEMPS/POPS... DDC 63 89 65 83 / 0 10 10 50 GCK 60 87 63 84 / 0 0 0 30 EHA 60 87 62 86 / 0 0 0 20 LBL 61 88 64 85 / 0 20 10 30 HYS 64 89 66 81 / 0 0 10 50 P28 67 90 68 83 / 0 20 30 60 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Umscheid LONG TERM...Umscheid AVIATION...Turner
Area Forecast Discussion
National Weather Service Goodland KS
628 PM MDT Sat Aug 11 2018 .UPDATE... Issued at 628 PM MDT Sat Aug 11 2018 With NE upper flow bringing smoke from the California fires back into the eastern portion of my CWA...have opted to mention patchy smoke and haze for the early evening hours. Since it is mixing down and affected visibility slightly...will monitor and expand areal coverage if necessary. && .SHORT TERM...(Today through Sunday night) Issued at 1205 PM MDT Sat Aug 11 2018 Today-Tonight: A dry/stable airmass will prevail over the Tri- State area through tonight, between an upper level ridge over the Rockies/High Plains and a stalled upper level low to the SSE (invof central TX). With little/no destabilization and little/no forcing, expect mostly clear skies through tonight. Simulated reflectivity products via the HRRR and NAM NEST are in agreement that diurnal convection will be relegated well south of the KS/OK border this aft/eve. Expect light/variable winds with highs in the lower 90s today and lows in the upper 50s to lower 60s tonight. Sun-Sun night: The upper level ridge over the Rockies/High Plains will begin to break down late Sun/Sun night as a potent upper level low (situated just offshore the PAC NW this afternoon) lifts slowly ENE/NE through southern British Columbia/Alberta into central Saskatchewan. The stalled upper low in central TX -- blocked from eastward progress by a N-S oriented ridge over the MS river valley -- is progged to retrograde slowly north toward a weakness in the de-amplifying ridge over the Central/Northern Plains late Sun night. Though isold convection cannot be entirely ruled out south of I-70 and east of Hwy 83 Sun night as low-level moisture advection commences, 12Z model guidance suggests that forcing attendant the broad upper low will largely be confined to the TX Panhandle, central OK, and far south-central KS through 12Z Mon. With the above in mind, expect dry conditions to persist Sunday through sunrise Monday. .LONG TERM...(Monday through Saturday) Issued at 1210 PM MDT Sat Aug 11 2018 The period begins with a very zonal upper-level flow, confined mainly to over the PAC NW and into Canada. A weak jet finger is centered over the Great lakes surrounding a cut-off low. Higher upper-level wind speeds can also be noted over CO and KS, outlining a weak upper-level low over E CO, down into NM, and the panhandles of TX and OK. Divergence aloft can be noted over KS and NE. As the pattern progresses forward, Cyclogenesis will occur in the vicinity of the divergence aloft and extend down to at least 700 mb. This low will essentially absorb into the longwave trough, pushing southward out of Canada by Tuesday. There is a discrepancy as to when the low will be absorbed into the longwave pattern, with the ECMWF lagging behind the GFS by almost an entire day. Both the GFS and ECMWF agree on timing and placement of the longwave trough as it enters the CONUS Tuesday. This longwave will support a surface cold front which will sweep across the northern plains Tuesday, Wednesday, and Thursday, approaching the AOR then stalling out by Friday and becoming more stationary in nature. This boundary provides the instability and lift needed to possibly produce generalized thunderstorms and increased cloudiness Tuesday onward. Disturbances in the flow will be present Wednesday and Thursday, according to both models. This will increase chances for precipitation along the eastern periphery of the AOR until Wednesday night at which point precipitation could blanket the entire area and push off to the east, exiting the AOR by Thursday evening. After this, conditions should remain quite dry until Saturday with weak cyclogenesis producing a mid-level shortwave trough again occurring over the intermountain area. This will keep thunderstorm chances in the forecast throughout the weekend and for the duration of the forecast period. Max temperatures will be in the lower 80s through Wednesday then steadily creeping up into the mid-80s by Friday. Cloud cover will prevent grueling hot temps throughout the week. Low temps will steadily remain the the lower 60s the entire week and into the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 506 PM MDT Sat Aug 11 2018 High pressure over the region during the forecast period will allow for both terminals to see VFR conditions. Winds for KGLD...SE around 10kts thru 05z Sunday...then SSW around 10kts. Winds for KMCK...SE 5-10kts thru 03z Sunday...then light/variable. By 16z...SE around 10kts. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JN SHORT TERM...VINCENT LONG TERM...SANDERSON AVIATION...JN
Area Forecast Discussion
National Weather Service Elko NV
216 PM PDT Sat Aug 11 2018 .SYNOPSIS...Moisture slowly increases during the next two days across central and eastern Nevada. This brings isolated thunderstorms to the region, except northwest Nevada where dry weather prevails. Smoke and haze persists across the region. && .SHORT TERM...Tonight through Monday. HRRR Smoke product indicates that the haze is not going anywhere soon, especially with a westerly component that brings smoke from the California wildfires. A weak trough shears northeast over the Pacific northwest this afternoon and tonight. The trailing edge of the trough boosts gradient flow over northwest Nevada for gusty winds late in the day and continuing this evening. Shallow cool front pushes into northwest NV overnight and becomes stationary between the northern border and I80. While the northern portion of the warm high dome gets flatten by shearing trough, the southern portion remains firm over southern Utah and Arizona. Monsoonal moisture streams northward over central and eastern NV during the next two days. Isolated diurnally driven thunderstorms will develop across this area, with higher coverage over the higher terrain (from the Toiyabes east to the Snake range). Southwest flow prevails over northwest NV, keeping that portion of the state dry. With the high warm dome no longer overhead, daytime temperatures will not be as hot, but remain above the seasonal norms. .LONG TERM...Monday night through next Saturday. Models are in generally good agreement through the extended period. Upper high center will weaken this weekend while splitting to the northeast and retreating southward which will cause daytime temperatures to cool down to between 85 and 95 degrees for the first half of next week. Although main trough energy will pass north of region, modest monsoonal moisture over the east half of the state will allow for isolated to perhaps scattered pockets of dry and wetter storms to occur on Tuesday and Wednesday afternoon/evenings across portions of northeast and central Nevada. A mid-level shortwave lifting northeastward across California could also trigger isolated storms farther west and north on Wednesday before shifting eastward on Thursday. Upper high is forecast to briefly rebuild over California into Nevada on Friday and next Saturday which should allow for dry, storm-free weather to return to the state with afternoon temperatures warming back up into the mid 90s to near 100. && .AVIATION...VFR but hazy conditions are expected through Sunday evening for KWMC KBAM KEKO KELY and KTPH with the possibility of MVFR visibilities primarily around and west-southwest of KWMC on Sunday as thicker smoke plumes from California wildfires impact western Nevada. Isolated thunderstorms have developed in the vicinity of KELY this afternoon with a better chance on Sunday as weak push of monsoonal moisture continues to slowly creep northward. && .FIRE WEATHER... Evening gusty winds to 35 mph across zone 467 will exist through much of the evening. Gusty winds will gradually diminish overnight. As cold front pushes into northwest Nevada overnight, humidity values will increase. Moisture gradually increases during the next two days bringing the threat of thunderstorms to central and eastern Nevada. Initially, isolated dry thunderstorms are expected but gradually become wet toward mid week. Sunday, the highest dry lightning threat will be across zone 454, 455, 457, and 470, but areal coverage will be isolated. Monday, the dry lightning threat includes 454, 469 and 470 but some storms will be wet. For zone 454 and 455, storms are likely to be wet as precipitable water continues to rise above 0.75 inches. Tuesday and Wednesday, higher confidence that most thunderstorms will be generating wetting rains. && .LKN WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 11 PM PDT this evening for Central and Western Humboldt County. && $$ 88/95/95/88
Updated for 00Z Aviation Forecast Discussion below.

&& .PREV DISCUSSION... /issued 305 PM CDT Sat Aug 11 2018/ DISCUSSION...Surface analysis this afternoon places a weak cold front from Southern Indiana, Illinois, Missouri, then back into Oklahoma. Regional WSR-88D radar trends indicate isolated to scattered showers and thunderstorms have developed along and south of this boundary with the nearest convection to the Mid-South near extreme Northeast Arkansas. As of 2 PM CDT, temperatures across the Mid-South are in the lower 90s at many locations. A weak cold front is expected to gradually drop south into the Lower Mississippi Valley tonight producing isolated to scattered showers and thunderstorms. The best chances for convection are expected to be predominantly north of I-40 through this evening. Surface based CAPE values at or above 3000 J/kg, Precipitable Water values around 1.7 inches, and overall shear remaining weak suggests the potential for pulse type thunderstorms producing wet microbursts with the potential for a few strong thunderstorms to an isolated severe thunderstorm. Damaging wind gusts along with localized heavy rainfall is possible with the stronger storms. Short term models indicate this weak front will become quasi- stationary across the forecast area for Sunday into Sunday night bringing isolated to scattered shower and thunderstorm chances to areas of East Arkansas, Southwest Tennessee, and North Mississippi. Shortwave mid-level ridging will try to build in for Monday and Tuesday. We may see a decrease in convective coverage during this period with generally isolated rain chances at best and primarily driven by convective temperatures being reached during the afternoon/early evening hours. Long term models indicate better chances for showers and thunderstorms will come towards mid to late next week as upper level ridging translates east and a mid level trough moves across the Middle/Lower Mississippi Valleys. This will bring an increase in shower and thunderstorm chances during this aforementioned time. CJC && .AVIATION... 00Z TAFs Main short term forecast concern is TSRA trends through late evening. Scattered TSRA north of JBR to east of MKL were occurring near a weak cold frontal boundary at 00Z. This front will show little further southward progress this evening. Expect a gradual decrease or consolidation in TSRA coverage as boundary layer stabilizes through 03Z. This dissipation may not be as quick to occur as typical under the normal midsummer upper ridge, as the Midsouth remains favorably-positioned with respect to an upper level jet core that we don`t typically see in mid/late summer. Have kept TSRA out of MEM TAF for the evening, given expected timing of storm dissipation. This scenario is supported by the HRRR and NAM-Nest models, but will need to monitor storm trends closely. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion
National Weather Service Pocatello ID
858 PM MDT Sat Aug 11 2018 .UPDATE...Frontal boundary in the western portions of the state making slow progress to the east tonight. Passage expected to be late tonight or early Sunday for most areas. Temperatures have fallen most areas with the loss of daytime heating. Outflow from weak convection over the central mountains has pushed into the Snake Plain, which has also contributed to locally cooler temperatures, along with breezy gusts over 30 mph in some locations. Since temperatures Sunday are still expected to be some 8-12 degrees cooler than today, depending on location, have allowed Heat Advisory to expire as planned. Gusty winds and low humidities Sunday, even behind the front, will remain and thus will leave the Red Flag Warning in place. There is still some concern about the potential for convection overnight, especially in the Central Mountains for fire concerns. Frontal passage could still provide enough lift in the area, where mid level instability still exists. Region is still in favorable region for upper jet dynamics as well. Current forecast grids maintain very weak PoP over the central mountains with isolated thunder mention, and despite low confidence in any one location seeing anything develop, am opting to leave mention in place overnight. HRRR develops some evidence of very weak convection across central mountains but also southern highlands near sunrise. Do not expect much, if any, precipitation out of it, but gusty outflows are possible. DMH && .AVIATION... VFR conditions are expected to continue across all terminals for at least the next 48 hours. Breezy west and southwesterly flow will gradually diminish tonight tonight ahead of a frontal boundary currently moving into western Idaho. This front is expected to bring little more than scattered high clouds and an eventual wind shift but a non-zero chance of isolated gusty showers does exist overnight. Breezy conditions are then expected Sunday behind the front. Gusts near 20kts should be common across area terminals. Smoke will also continue to varying degrees at all terminals, but not expecting vsbys below 6SM. TAX && .PREV DISCUSSION... /issued 232 PM MDT Sat Aug 11 2018/ DISCUSSION...Today Through Next Saturday. Our main weather concerns this afternoon/eve continue to be extreme heat, and critical fire weather with possible isolated t-storms. EXTREME HEAT: A Heat Advisory remains in effect until 9 PM this eve for the Snake Plain, eastern Magic Valley, and Southern Highlands. High temps are forecast to top out at similar values to what was observed yesterday, generally 98-104. A few other valley locations, such as Challis and Driggs, may reach similar values. Multiple high temp records will likely be broken again this afternoon. Model guidance, including the MAV/MET tables, have continued to run slightly cooler than what has actually been observed each afternoon during this heat wave, so once again bumped forecast highs up just a bit above guidance, and also made area adjustments based on observed temps yesterday. There is an increased risk of heat-related illnesses and injuries today. Residents should take today`s heat seriously...these high temperatures could be dangerous if precautions are not taken. Heat-related safety information is available on our social media pages, as well as at and THUNDERSTORMS: We do carry a slight chance of a few isolated showers and t-storms across portions of the Central Mntns this afternoon and eve ahead of a cold front, generally east of Stanley and Ketchum and north of Darlington. We cannot rule out isolated activity as far south and east as Craters of the Moon, Arco, and Monida early tonight as well. Generally most locations will remain dry, but this potential will be of concern for wildfire crews. NAM/RAP forecast soundings carry plentiful low-level dry air with inverted-V signatures, high LCLs, and notable DCAPE values of 1,200 to 1,600 J/kg, confirmed by the latest SPC mesoanalysis. Thus, t-storms may be capable of producing lightning and strong downdraft/outflow winds. A Red Flag Warning remains in effect as well for the Central Mntns through Sunday evening. See the FIRE WEATHER section below for more details. Breezy conditions are expected Sun afternoon behind the cold front, with a few isolated showers/t-storms possible in the Southern Highlands and Island Park region. Relatively cooler temps are expected, down 8-10 degrees compared to today. Then, some monsoonal moisture looks to expand north toward our forecast area for Monday through Saturday. The GFS and ECMWF have drifted into slightly better agreement with the overall pattern, but the GFS is still wetter, and confidence in placement and coverage of showers/t-storms is low throughout the week. Right now, Wed afternoon/eve looks like the wettest period. With increased moisture, storms may be able to put down some more noticeable localized rainfall amounts. Temps remain a bit cooler through the week, but still a bit warmer than average. - KSmith/RS AVIATION... VFR conditions are expected at all TAF terminals across SE Idaho for the next 48 hours, with moderate to high forecast confidence. A few isolated t-storms are possible in portions of the Central Mntns this afternoon and evening. It still looks like this activity will remain north and east of KSUN, but we cannot rule out an outflow boundary with gusty/erratic winds making it into the Wood River Valley. We will monitor for any needed updates. Smoke and haze will also continue to varying degrees at all terminals, but not expecting vsbys below 6SM. - KSmith/RS FIRE WEATHER... Red Flag conditions will continue through this evening across the central mountains (422, 475 and 476). Gusty winds, low humidity and Haines 6 remains in place. Forecast was updated for greater area of isolated dry thunderstorms with gusty out flow winds in the Salmon-Challis Forest this afternoon and evening. The latest model run has slowed the arrival of the front through Stanley and Clayton area until about 0400-0500 hours Sunday morning, winds at ridge top may increase a couple hours ahead of the front. Humidity tonight on mid and upper slopes should max around 30- 35 percent in the central mountains. About 7-9 degrees colling on Sunday will bring the Haines down to a 5 in most areas. Monsoon moisture and a slight chance of thunderstorms will sneak northward into the Southern Sawtooth Sunday afternoon and evening, flowed by increasing threat Monday and Tuesday. A few select cells may produce a tenth of an inch precipitation. This round of monsoon moisture reaches a max across southeastern Idaho on Thursday, then will be nudged eastward by a disturbance off the Pacific late Friday. Multiple disturbances in northwesterly flow next weekend will probably bring a few breezy days and not much precip. - RS AIR STAGNATION... Smoke and haze from numerous wildfires burning across Idaho and the Pacific Northwest continue to affect the region, and will result in periods of degraded air quality across SE Idaho. Continue to monitor data and forecasts from the Idaho Department of Environmental Quality (ID DEQ) for the latest on regional air quality. We currently carry haze in the forecast for the entire CWA through Tues morning. We MAY see some improvement by tomorrow behind the cold front, but this is hard to forecast, and additional smoke may still be able to stream into the region from the larger fires in CA and OR. - KSmith/RS && .PIH WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 9 PM MDT this evening for IDZ051>059-075. Red Flag Warning until 10 PM MDT Sunday for IDZ422-475-476. && $$
Area Forecast Discussion
National Weather Service Portland OR
840 PM PDT Sat Aug 11 2018 .SYNOPSIS...An upper level low pressure system resulting in the cooler temperatures and scattered showers across the area today will gradually give way to upper level high pressure and a return to hot temperatures by early next week. && .SHORT TERM...Tonight through Tuesday...Still some scattered showers over the north coast and over the north part of the Cascades this evening, but the overall trend has been for showers decreasing with the loss of diurnal heating. The main upper trough was beginning to stretch out and lift ne into BC, but as this happens there was still a vort max in the sw end of the trough swinging east, set brush the nw part of the forecast area overnight. Will cut back pops to account for the ending of showers over the southern parts of the forecast area. Remainder of short term discussion unchanged...Water vapor satellite imagery this afternoon reveals an upper level low pressure lifting northeastward towards the Strait of Juan de Fuca. A 500mb cold pool near -19C is accompanying this storm system, which has helped to produce several short lived thunderstorms over the Puget Sound. Because this upper level storm system is just brushing our region, a strong gradient in temperatures aloft exist across our CWA this afternoon. For example, the RAP suggests 500mb temperatures of -17C to -18C are currently in place over Pacific County vs. -9C to -10C towards Lane County. This considerable difference in cold air aloft (a decent proxy for instability present) has led to fairly widespread showers developing across southwest Washington today while areas farther south towards Lane County have remained dry. Rainfall amounts across our northern zones have generally remained under a tenth or two tenths of an inch, but a few locations have had upwards of 0.50-1.00" of rain including areas around Tillamook, the west slopes of the Willapa Hills and Kalama. Models remain in good agreement the upper level low pressure will shift northeastward into Canada overnight, which should lead to the threat of showers decreasing from south to north. The lone exception to this will be along the north Oregon and south Washington coast where models suggest a weak surface low pressure currently found off Vancouver Island will drop southeastward overnight. This should help to maintain a chance for light rain through the overnight hours that could even linger into Sunday morning along the north coast. 500mb heights look to slowly build across the region through early next week as a weak upper level trough gives way to shortwave ridging. This should lead to temperatures returning to near average levels Sunday and climbing into the 90s for the Willamette Valley and Columbia River Gorge on Monday. At this point Tuesday looks to be the hottest day next week with temperatures likely climbing into the mid to upper 90s per the GFS/EC and their ensemble members. /Neuman .LONG TERM...Tuesday night through Saturday...No changes. Previous discussion follows. Ridging builds back up over the Pacific NW next week. A weak shortwave trough swings through midweek, cooling us a few degrees Wednesday, and dropping temperatures back down into the upper 80s on Thursday. We should remain dry through the period, though. Ridge builds back up even stronger going into next weekend on the GFS, while the ECMWF keeps the ridge weaker. This lowers confidence in temperatures going into next weekend. With high pressure, we will probably see temperatures get back up into at least the low 90s next weekend, but the GFS solution would have us hotter than the ECMWF solution as well as the current forecast. - McCoy && .AVIATION...A weak surface low is apparent on satellite and radar as of 03z. Main impact is to generate some stratus over the waters which could bring additional weak showers or drizzle to KAST for the next several hours. Also looks like the stratus will work south along the coast reaching KONP in a couple hours or so. Expect cigs to lower further into IFR cigs reaching near 007 07-08z, remaining there until starting to lift by late Sunday morning. WIll also see a surface thermal low stretch north along the coast to bring gusts 20-25 kt to KONP Sunday afternoon and night. Inland remains VFR and will likely remain so until later overnight when models show MVFR stratus cigs of 020-030 to develop around 12-14z. Stratus should dissipate by 17z and have modest confidence in that timing. KPDX AND APPROACHES...Generally VFR through tonight, with scattered showers possible through this evening. MVFR cigs look to impact the terminal between 10-18Z. VFR conditions return by late Sunday morning. JBonk/64 && .MARINE...Main changes were to adjust winds related to the increasing pressure gradient between surface high pressure drifting south Sunday morning and deepening surface thermal low pressure pushing north along the northern California/southern Oregon coast coast. Expect gusty winds to 25 kt to reach all portions of the central Oregon coastal waters, thus have added the inner waters to the advisory as well. Also stretched the advisory a little longer into Monday morning with winds easing near daybreak. High pressure will linger over the NE Pac for much of the upcoming week, with conditions flirting with advisory criteria during the afternoon/evening hours, especially south of Cascade Head. Seas are currently around 3 to 4 ft this afternoon, but will build to around 5 to 6 ft Sunday and Monday, mainly south of Newport as northerly winds increase. Seas could build to around 7 to 8 ft later in the week, especially over the outer waters, but confidence is low as much of the growth will be determined by how much of the tropical cyclone swell is pushed this way. JBonk/64 && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory for winds from 3 PM Sunday to 6 AM PDT Monday for Coastal Waters from Cascade Head OR to Florence OR out 60 NM. && $$ Interact with us via social media: This discussion is for Northwest Oregon and Southwest Washington from the Cascade crest to 60 nautical miles offshore. This area is commonly referred to as the CWA or forecast area.
Area Forecast Discussion
National Weather Service Tallahassee FL
911 PM EDT Sat Aug 11 2018 .UPDATE... Very minor update to PoPs for the overnight hours, otherwise the previous forecast was on track with no other changes necessary. && .PREV DISCUSSION [758 PM EDT]... .NEAR TERM [Through Tonight]... Plenty of cloud cover across the area early this afternoon with a little drier air moving in through the mid levels across the area. Thunderstorms this afternoon appear to be hindered due to these two features. HRRR keeps the area mostly dry through mid afternoon then develops isolated storms over AL/GA which move southeast into our counties through early this evening as well as portions of the FL panhandle. Low end chance PoPs are reasonable and left as is. A weak shortwave trough moving through westerly flow will help spark convection in the marine zones west of Apalachicola this evening and overnight. Some of these may move inland overnight across coastal sections of the FL panhandle and western Big Bend. Elsewhere, tranquil conditions will prevail under mostly clear skies and lows into the low/mid 70s. .SHORT TERM [Sunday Through Monday Night]... A mid to upper level closed off low over the Great Lakes today will slide southeastward into the Ohio Valley. The weak frontal boundary out ahead of it will be draped across the tri-state area Sunday and Monday, shifting northward ever so slightly on Monday. The dry side of the front will sit mostly over our southeast AL and southwest GA counties, resulting in the highest PoPs over north FL. Deep layer shear will be low, less than 20 knots, so organized severe weather is unlikely. Afternoon MLCAPE values will be around 1000-1500 J/kg on Sunday, though and will increase to around 1500-2000 J/kg on Monday, so a few strong to severe storms will be possible both days. The main threat will be downbursts of damaging (50-60 MPH) winds. Highs will be in the low 90s, with heat indices peaking around 100 both days. Overnight lows will be in the low to mid 70s. .LONG TERM [Tuesday Through Saturday]... The mid to upper level low will weaken and move off the northeastern coast by Wednesday, allowing the front draped across our area to dissipate. PoPs will remain high Tuesday and Wednesday, but return to near normal (30-50%) through the weekend as deep layer ridging builds and seabreeze becomes the main forcing once again. Temperatures will peak in the low 90s each afternoon and dip into the low to mid 70s each night. .AVIATION [Through 00Z Monday]... A shower or thunderstorm may briefly impact the ABY terminal later this evening. Otherwise, VFR conditions are expected to prevail at all terminals through the period. The best chance for a thunderstorm on Sunday will be at TLH and VLD so went with VCTS after 18z. Winds will be light and mostly from the north to northwest. .MARINE... Moderate westerly flow will persist through the weekend, but wind speeds will lower heading into next week as high pressure builds over the area. Seas will be around 2 to 3 feet through Sunday then lower to around 1 foot around Monday. .FIRE WEATHER... Hazardous fire weather conditions are not expected over the next several days. .HYDROLOGY... Scattered showers and thunderstorms could produce brief and localized heavy rainfall through this afternoon and Sunday. As we get into the start of the work week a mid-level disturbance and surface boundary forcing will cooperatively work together and favor a higher coverage of showers and thunderstorms for Monday and Tuesday. Localized minor flooding is possible with slower moving and high rainfall producing storms. However, widespread flooding for this period is not expected. During the remainder of the week we will return to a typical sea breeze driven afternoon thunderstorms regime. .SPOTTER INFORMATION STATEMENT... Spotter activation is not requested. However, spotters are always encouraged to safely report significant weather conditions when they occur by calling the office or tweeting us @NWSTallahassee. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 74 92 73 92 72 / 20 40 20 60 20 Panama City 76 92 76 90 75 / 30 30 20 30 20 Dothan 73 92 74 91 73 / 20 20 10 40 20 Albany 73 93 74 92 74 / 20 20 20 40 30 Valdosta 73 92 72 91 72 / 10 40 20 50 30 Cross City 74 90 74 88 74 / 20 40 20 40 30 Apalachicola 77 89 77 89 76 / 30 40 20 40 20 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk until midnight EDT /11 PM CDT/ tonight for Coastal Bay-Coastal Gulf. GA...None. AL...None. GM...None. && $$ UPDATE...Harrigan NEAR TERM...Scholl SHORT TERM...Nguyen LONG TERM...Nguyen AVIATION...Barry MARINE...Nguyen FIRE WEATHER...Harrigan HYDROLOGY...DiCatarina
Area Forecast Discussion
National Weather Service Tucson AZ
225 PM MST Sat Aug 11 2018 .SYNOPSIS...Monsoon moisture will remain over southern Arizona through the coming week resulting in scattered showers and thunderstorms, mainly during the afternoon through evening lingering at times into the overnight hours. Some variation in the number of storms will occur from day today. Temperatures will generally remain within a few degrees of normal for mid August. && .DISCUSSION...Latest regional radar imagery shows isolated to scattered thunderstorms are ongoing across southeast Arizona this afternoon. Thus far, the storms haven`t been very impressive for our area with the strongest storms across far northern Sonora. Latest RAP analysis still shows adequate instability with about 500 J/KG of MLCAPE for areas north and east of Tucson to about 1000 to 1500 J/KG from Tucson south and westward. Meanwhile, PWAT values are about 1.25 to 1.5 inches from Tucson westward but down around 1 inch across Graham and Greenlee County with even lower values on the rim which will prevent storm development up there today from moving into the lower elevations. Thus, we`re going to be dependent on locally generated storms and outflows. Main concerns will be some gusty winds and brief downpours but any flooding concerns should be mitigated by 10 to 20 mph storm motions. Based on review of both the 12Z deterministic models guidance and CAMs, a similar pattern is expected for Sunday with northeast mid level flow. While moisture across southern Arizona will be similar to today, there will be a bit more moisture on the rim which could send a few thunderstorms down our way into the lower elevations with isolated to lower end scattered coverage looking good for Sunday and Sunday evening. As the mid/upper level high reconsolidates across Arizona Monday and Tuesday, there will be enough moisture for at least isolated coverage but it should remain slightly below climatological normals for mid August. A more favorable pattern will setup starting later this week, perhaps as early as Wednesday afternoon/evening as a more established east to southeasterly flow aloft and deeper moisture moves into the area. Both the 12Z ECMWF and GFS are showing an inverted trough pushing into the area Wednesday night, continuing Thursday and perhaps into Friday with an significant uptick in convection. Otherwise, temperatures will be within a few degrees of normal through the forecast period. && .AVIATION...Valid through 13/00Z. Scattered TSRA already developing with at leash VCSH possible at all 3 TAF sites through 00Z along with BKN080-100 cigs. Outside of thunderstorm gusts, expect mainly light east/southeast winds to prevail at all sites. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...The pattern remains favorable for daily scattered thunderstorm development areawide into next week. Near or slightly below normal temperatures will continue throughout the forecast period. 20-ft winds will be terrain driven at less than 15 mph, except for in and around thunderstorms where strong outflows may occur. && .TWC WATCHES/WARNINGS/ADVISORIES... None. && $$ Discussion...Lader Aviation/Fire Weather...Leins Visit us on Facebook...Twitter...YouTube...and at
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
452 PM MDT Sat Aug 11 2018 .DISCUSSION...(This Evening Through Saturday) Issued at 154 PM MDT Sat Aug 11 2018 Upper-level analysis shows a broad ridge over the western/central states, with a low pushing into the Pacific Northwest. Skies across the northern plains are sunny, although smoke continues to drift into the region, mainly east of the CWA. With a surface trough to the west, winds are southeasterly around 10 kts. Temperatures are rising into the 90s, with some places reaching 100 degrees. Good meteor-shower-viewing conditions are in tonight`s forecast, with clear skies and temperatures slowly decreasing to the lower 60s. Dry weather will continue Sunday, and another hot day is expected beneath the thermal ridge. Highs will be around 100. Across the SD plains, southerly winds will be breezy ahead of the incoming trough. Sustained winds will be 20 to 30 mph, with gusts around 35 mph. Clear skies are also expected for most areas Sunday night, although some clouds may start moving into northwestern parts of the CWA with a cold front; additionally, the HRRR is hinting at smoke moving into the same areas. A more active pattern will develop Monday, bringing near daily chances for showers and thunderstorms for next week. Temperatures will cool behind the cold front. Tuesday still looks like the coolest day, with highs in the mid 70s to mid 80s on the plains, and 60s/70s in the Hills. && .AVIATION...(For the 00Z TAFS Through 00Z Sunday Evening) Issued At 449 PM MDT Sat Aug 11 2018 VFR conditions are expected through the TAF period. Upper-level smoke will persist across the area, increasing a bit on Sunday, but no reductions to low-level visibility are expected. There is some potential for low level wind shear tonight on the plains east of the Black Hills. Southerly winds with some gusts over 25 kt will be found on the South Dakota Plains on Sunday. && .FIRE WEATHER... Issued At 154 PM MDT Sat Aug 11 2018 RH across northeastern WY and parts of northwestern SD is dipping into the teens. Winds over these areas are 10 to 15 mph, with gusts of 20 to 25 mph. Will let the Red Flag Warning continue for these areas. Hot and dry conditions will continue Sunday, with winds becoming breezier across the SD plains. Weather still looks favorable for critical fire weather conditions to develop across northwestern and central SD. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...Red Flag Warning until 9 PM MDT Sunday for SDZ261. Red Flag Warning from noon to 9 PM MDT Sunday for SDZ266. WY...Red Flag Warning until 9 PM MDT this evening for WYZ259-297-298. && $$ DISCUSSION...Pojorlie AVIATION...7 FIRE WEATHER...Pojorlie
Area Forecast Discussion
National Weather Service Las Vegas NV
800 PM PDT Sat Aug 11 2018 .SYNOPSIS...Thunderstorm chances will remain in areas roughly along and east of a line from Barstow to Rachel this evening, then shift to areas north and east of Las Vegas for Sunday through early next week. Temperatures will remain several degrees above normal over the weekend into early next week. && .NEAR TERM...Strong thunderstorms now extend along a line from near Moapa down to Laughlin, with numerous reports of severe winds coming in, including a wind gust to 62 mph at Bullhead City airport and gusts over 50 mph near Moapa. KESX radar is sampling this outflow boundary moving towards Las Vegas, and should reach Nellis AFB around 830, and into the central Vegas Valley by 9pm. Strong wind gusts of 40-50 mph are likely to spread across the Valley, and Lake Mead in the next 90 minutes. Thunderstorms have showed little signs of weakening at this point, and may in fact reach the Vegas metro after 900 pm. Suspect another few hours of thunderstorms are likely across Clark and eastern San Bern counties as the ongoing activity develops westward. Activity should begin to wane by midnight as the storms outrun the deeper moisture and instability. -Outler- && .SHORT TERM...through Monday night. Storms tonight should linger for a time as they ride the cold pool and slowly diminish. Currently think storms should end by 06Z overnight. Thunderstorm activity in Clark County is looking less likely, and the HRRR has backed off the intense solution it had earlier. Sunday will be a transition day as a ridge of high pressure drifts eastward into Arizona by Monday. Unsure how "quiet" Sunday will be. Compared to today, storms should be more limited as we lose moisture, especially in the afternoon. However a few models show some midlevel energy circling around the main anticyclonic flow, so dont think it will be quiet day either. Best chance for storms will again by over MOhave County where there will be lingering instability and dry air will be slowest to intrude. By Monday, drier air and anticyclonic flow will be overhead and strengthening. Precipitation chances should be limited to the edges of the high`s center, which would limit precipitation chances to the Sierra, northern and eastern Lincoln County, down into eastern Mohave County. PWATs should be at or less than an inch, so thunderstorm activity will be isolated. .LONG TERM...Tuesday through Saturday. High pressure situated over the Desert Southwest will shift eastward Tuesday through Thursday as low pressure approaches the California coast which will help strengthen southerly flow across the area. There will still be limited instability on Tuesday and activity should be more diurnally driven and focused over the higher elevations. High-grade monsoon moisture will push northward from the Gulf of California reaching our southern zones Tuesday night into Wednesday morning; overspreading a majority of the area on Wednesday and Thursday. As such, storm activity is expected to increase each day from Tuesday to Thursday with Thursday looking to be particulary interesting as a shortwave trough pushes northward into central Arizona. Highest precip chances remain over Mohave, eastern San Bernardino, Lincoln, and Clark counties Wednesday and Thursday. A downward trend in storm activity should begin on Friday as high pressure builds back in. As ridge weakens and moisture increases Tuesday through Thursday temperatures look to decrease a degree or two each day. However, as high pressure builds back in on Friday temps will begin to rebound back above seasonal normals. && .AVIATION...For McCarran...Thunderstorms should be confined to the Peach Springs and Mormon Mesa corridors this evening. There is a slight possibility that storms over southwest Utah could move toward Las Vegas and hold together. There will be potential for winds from distant storms to affect the terminal area...primarily from the southeast this evening, but there is also possibility wind gusts could come in from the northeast after 05Z. Otherwise a south wind component is expected through this evening followed by a south- southwest component late tonight through Sunday with only FEW-SCT clouds with bases above 12 kft. For the rest of southern Nevada, northwest Arizona, and southeast California...Thunderstorms over northwest Arizona and southwest Utah may produce gusty winds through early this evening which could travel far from the originating storms. The terminals most likely impacted will be KEED and KIFP. The rest of the region will see mostly benign weather with reduced visibility`s from smoke/haze continuing across the region through Sunday. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM...Wolf AVIATION...Adair LONG TERM....Guillet For more forecast information...see us on our webpage: or follow us on Facebook and Twitter