Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/07/21

Area Forecast Discussion...UPDATED
National Weather Service Amarillo TX
648 PM CDT Tue Apr 6 2021 .AVIATION... For the 00Z TAFs, a cold front will move through the terminal sites this evening with strong north northwest winds in its wake. The overall strongest winds are expected to occur at KGUY and KDHT. No precipitation is anticipated with this cold frontal passage. Winds are forecast to diminish at KDHT and KAMA early Wednesday afternoon, followed by KGUY very late Wednesday afternoon. 02 && .PREV DISCUSSION... /Issued 257 PM CDT Tue Apr 6 2021/ SHORT TERM...Today through Tomorrow Night... Latest upper level analysis revealed a compact but potent closed low moving over northwest CO. Mid level water vapor imagery showed very dry air moving across the Panhandles associated with a subtle lead wave. The latest trends suggest the stronger mid and upper level flow is still over NM with the main wave, and just south of the Panhandles with the lead wave. The 500mb jet will not make it into the Panhandles until later this evening. The net result is that winds across the Panhandles have not been as strong as expected so far this afternoon, with most seeing winds of 15 to 20 knots with gusts near 25 to 35 knots. The Panhandles are also in the left exit region of the mid and upper level waves which is not helping with the deep mixing process. That being said, very dry surface conditions have been noted with dew points falling into the teens and upper single digits. So far, the HRRR and RAP have been too low with dew points, so have leaned more towards NBM compared to previous forecast, and this seems to match better with observations. The closed low will march across the Rocky Mountains and end up over central KS by Wednesday morning. This will promote a fairly strong cold front with sharp pressure rises (3mb/hr) across the Panhandles this evening (3-4 mb/hr in the north and 2-3 mb/hr in the south). Some models also suggest a localized 850mb jet maxima behind the front this evening across the northwest and north central zones, and weakening as it shifts across the eastern zones. Upcoming shifts will want to watch the trends with this feature, because the strongest guidance (GFS) suggest near 55 knot winds within the jet max. If this were to verify, there could be a brief period with near 60 mph wind gusts in the northern zones just behind the front as model soundings do keep dry adiabatic lapse rates up to 850mb. For now, will issue a wind advisory for the northwest TX Panhandle and the western two thirds of the OK Panhandle based on where the strongest pressure rises occur. Winds should decrease some towards sunrise Wednesday, but will become breezy again by Wednesday afternoon on the backside of the low. Winds on Wednesday afternoon will be mainly low level jet driven given modest wind speeds from 850mb to 500mb. Temperatures will be cooler across the Panhandles with highs near normal. FIRE WEATHER... Critical fire weather conditions will continue through this evening as westerly winds of 20 to 30 mph along with RH values in the single digits and teens extend through about 9 PM (RFTIs around 4 to 7 with some isolated 8s). So far, fuels seem to be limiting fire starts as only one hot spot has been detected (and it was outside of the critical area in Wheeler Co). RH values will rise sharply behind a cold front tonight, but this is also when we expect the strongest winds to occur. There is a window between roughly 8 PM and 2 AM where northwest twenty foot winds could peak around 35 to 45 mph (a 50 mph gust can`t be ruled out in the northwest and north central zones). Northwest winds are expected to decrease through sunrise, but should become gusty again Wednesday afternoon as the main system passes to our north. Northerly winds peaking around 20 to 30 mph with higher gusts will be possible Wednesday afternoon. Very dry surface air will remain in place as RH values drop into the low teens. This will result in elevated conditions given RFTIs in the 2 to 4 range. Fuels transitioning to green will be the main limitation. LONG TERM...Thursday through Monday... Dry weather conditions expected throughout the forecast period. With quite an active northern stream jet, the southern CONUS will miss out on most of the precipitation chances through early next week. With the exception of an occasional cold front moving through the Panhandles, temperatures overall will remain at or above average. Starting Thursday through Sunday, temperatures will be above average in the 70s and lower 80s. A series of cold front early next week will drop temperatures back to near average. Meccariello FIRE WEATHER... Elevated fire weather conditions are possible Thursday through Sunday. If prolonged cured fuels occur along with gusty 20 ft winds sustained above 15-20 MPH, critical fire weather conditions could also be possible among these aforementioned days. Min RH values will be consistent below 15 percent throughout the Panhandles Thursday through Sunday with max RFTI values of 2 to 3. Meccariello && .AMA Watches/Warnings/Advisories... TX...Red Flag Warning until 9 PM CDT this evening for the following zones: Armstrong...Carson...Dallam...Deaf Smith...Donley... Gray...Hansford...Hartley...Hutchinson...Moore...Oldham... Palo Duro Canyon...Potter...Randall...Sherman. Wind Advisory until 1 AM CDT Wednesday for the following zones: Dallam...Hartley...Sherman. OK...Red Flag Warning until 9 PM CDT this evening for the following zones: Cimarron...Texas. Wind Advisory until 1 AM CDT Wednesday for the following zones: Cimarron...Texas. && $$
Area Forecast Discussion
National Weather Service Gaylord MI
942 PM EDT Tue Apr 6 2021 .UPDATE... Issued at 847 PM EDT Tue Apr 6 2021 Surface boundary is largely stalled from eastern Ontario down through Wisconsin and to low pressure in the central Plains. Some semblance of a warm front arcs across eastern Upper and down through NE Lower Michigan into Lake Huron, although that is muddied by a strong afternoon inland lake breeze push through NE Lower Michigan that became the focus for showers and thunderstorms late in the afternoon. That boundary has pressed south of HTL and West Branch as of this hour. Upstream, a warm advection wing of showers/storms has developed across central and northern Wisconsin, within a region of increasing low level flow and renewed warm advection surge. Strongest warm advection forcing and convection should continue to lift north/northeastward into the U.P. and out of our area. That said, it`s not out of the question that we could see a few showers pop along the easternmost extension of the warm advection wing overnight into Wednesday morning. UPDATE Issued at 427 PM EDT Tue Apr 6 2021 Deep convection has rapidly fired between Waters and Atlanta since the original AFD issuance. This is a general zone of both colliding lake breezes, and the fine line/stalled front mentioned in the original discussion. Pops have been boosted in this area. Instability is quite meager this far north; the highest SbCape (near 1k j/kg) is analyzed near HTL-Gladwin. Do not expect this activity to be terribly vigorous. && .NEAR TERM...(Through Tonight) Issued at 317 PM EDT Tue Apr 6 2021 ...Fog, maybe some spotty precip... High Impact Weather Potential...Low. Areas of fog overnight, especially near Lk Huron. A boundary remains stalled out over northern lower MI. A fine line is evident on radar just north of the office, with rain- and lake-cooled air to the north. A few showers have been kicking off near Presque Isle Lt, but these have been exciting east. Some decaying showers are also seen from CAD to HTL. We otherwise see the proverbial mix of sun-and-clouds, and south of the boundary, temps are very warm. (A friendly reminder that normal highs are still only in the mid-upper 40s.) Dew points have also steadily risen, into the 40s everywhere and creeping past 50f in some places south of the boundary. SPC mesoanalysis indicates that though we are starting to develop some SbCape (circa 500j/kg) south of the boundary, any MlCape is still very small and capped. A bubble of somewhat greater instability is seen between GRR and LAN. That pocket of more unstable air is progged to develop ne-ward, with still a decent amount of daylight ahead of us. The se quarter of the forecast area (south and east of Grayling) should have the best shot at cooking off a shower/t-storm late this afternoon thru mid evening. At times the HRRR has been progging reasonably vigorous updrafts with this activity, but at this juncture, don`t think we will muster enough instability for strong storms, let alone a svr threat. Would not be terribly surprised to see isolated convection elsewhere, but to a large degree have decreased pops late today. Once the diurnal heating cycle is over, we remain in an environment with relatively steep lapse rates well aloft (above 8c/km when lifting from 650mb). There is always some CIN present before this can be realized, and a paucity of forcing to overcome it. Showers/t-storms are expected to develop and lift across nw WI and western upper MI tonight, but unlike last night, this should not take a run at us. Suppose something isolated could cook off in the relatively warm/moist air aloft, especially overnight when we see more cooling at the top of an elevated moist layer. But only small chance pops are supported, and will not have any thunder. Given the moist BL/higher dew points noted above, and light winds under partly cloudy skies, fog is expected tonight. There will be a marine contribution to fog potential, noting that water temps are still in the mid-upper 30s over much of the Great Lakes. With just a touch of a light synoptic easterly breeze overnight, fog will be most extensive near Lk Huron. Min temps from near 40/lower 40s for APN/Straits/eastern upper MI, to the low and perhaps mid 50s TVC/Gladwin and south. && .SHORT TERM...(Wednesday through Friday) Issued at 317 PM EDT Tue Apr 6 2021 ...Thunder Possible, Periods of Rain Thursday... High Impact Weather Potential...Thunder possible. Not expected to be severe. Pattern Synopsis/Forecast and possible impacts...Wednesday, The models still are on track with the low moving through Kansas through the day. The warm front is still expected to move north through the forecast area, allowing us to get into the warm sector and with the moisture increasing afternoon showers and thunderstorms will be possible, but not expected until the late afternoon. However, the bulk of the convection will be Wednesday night, when the low in the Plains slowly moves from Kansas to Missouri. The showers and thunderstorms will get into the chance category as the cold front becomes more of a player as it nears the Upper Great Lakes. Most of the thunder should be elevated as the showalter index is +/- 0C during the night, and there is no SBCAPE or MLCAPE through that time. Thursday, The GFS and ECMWF are in good agreement as the 500 mb low moves into E Iowa/W Illinois by the evening and the rain spreads over the forecast area, by 00z/Fri. Thursday night, The GFS/ECMWF/SREF are in good agreement as we get into periods of rain for the forecast area into Friday morning. Friday, The 500 mb longwave trough is in the C Plains, with the cut off low in S Wisconsin by 12z/Fri, and a potent shortwave diving into the longwave trough in the foothills of the Rockies. The Cut off low affecting us, begins to move a bit faster as the shortwave develops on its heels in the C Plains. This continues the periods of rain as our low moves into W Upper by 00z/Sat. .LONG TERM...(Friday night through Tuesday) Issued at 317 PM EDT Tue Apr 6 2021 High Impact Weather Potential...Minimal, but non severe thunder is expected, at this time, through Saturday. Extended (Friday night through Tuesday)...Friday night, as the low continues to move north, the rain begins to move out of the region with most of out of the lower peninsula by 12z/Sat. Saturday,The models are hinting at precipitation free start, but by the afternoon the shortwave trough, talked about in the section above, is rotating along the some path as the first low, and is somewhere in the central Mississippi Valley by 00z/Sun. So the models disagree with the position, which changes the timing of the rain with this low, moving into the forecast area. The ECMWF looks the fastest, but all the models have rain in the forecast area sometime on Saturday night. Sunday, Models have differing opinions of where the low moves but the answer for will it rain or not, is yes. To top it off, the longwave 500 mb pattern with its trough in the center of the country, introduces us to another 500 mb shortwave diving into the N Plains somewhat following the second shortwave (so this makes three that we are following from the short term to the long term) as it moves into New England. So maybe a bit of a break Sunday night. Monday, It looks like the upper air pattern is trying to turn into a blocking pattern(if you take the GFS at face value), but we are on the wet side of the low that is stuck. The ECMWF just has a meandering cut off over the Upper Great Lakes. So rain for Monday. Tuesday looks wet as well with either the cut off over the region (ECMWF) or rotating lows through the longwave (GFS) that continues the periods of rain. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 942 PM EDT Tue Apr 6 2021 Another tough cloud forecast night...again. Thicker VFR cloud cover is looking to spread back into the region through the course of the night as another pulse of warm advection forcing pushes up through the region. But bigger challenge remains fog/low cloud development. That seems most probable across the tip of the mitt and a chunk of NE Lower Michigan where the Lake Huron lake breeze boundary pushed through late in the afternoon along with some rainfall. I have both PLN and APN trending to MVFR as we go through the night. For Wednesday, after whatever morning fog/lower cloud cover we do have during the morning, SCT-BKN VFR skies should return. With heating, additional showers (thunder?) may bubble up Wednesday afternoon into Wednesday evening, although probabilities again are too low to include in any TAF locations as of right now. Additional lower end shower chances continue through Wednesday night. && .MARINE... Issued at 317 PM EDT Tue Apr 6 2021 Winds and waves will diminish into tonight, as the pressure gradient decreases, even with a stalled front over northern lower MI. A more humid airmass is in place, and with very light easterly winds, marine fog/stratus seems likely to develop tonight into Wed, especially on Lk Huron. Otherwise fairly quiet for marine interests. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...BA NEAR TERM...JZ SHORT TERM...JL LONG TERM...JL AVIATION...BA MARINE...JZ
Area Forecast Discussion
National Weather Service La Crosse WI
1054 PM CDT Tue Apr 6 2021 .SHORT TERM...(Tonight through Friday) Issued at 130 PM CDT Tue Apr 6 2021 BIG PICTURE: upper level low swings out of the southern Rockies today, meandering across the southern plains before lifting northward over WI by 12z Fri. Ripples in the upper level low pinwheel around the closed low. The low would probably setup shop for a couple more days if not for another shortwave trough diving southeast out of the PAC NW, undercutting the low and kicking it north into Canada later Friday night. The end result is on and off showers Wed-Fri. A few storms possible - mostly tonight into Wed. LATE THIS AFTERNOON/TONIGHT: a left over west-east running outflow boundary over IA trying to lift northward, associated with mid level clouds but not much/if any pcpn. Meanwhile, a somewhat weak MCV associated with a small cluster of shra/ts over southwest IA is advancing northeast. Meso models do capture this feature, and bring it across the forecast area later this evening. However, not a lot of response via convection - more isold in nature (if anything). Think this under cuts the potential - and while not as likely as the convection west/north with the sfc front, will hold some small pops and monitor to see if further adjustments will be need. As for that front...the boundary lies just outside the forecast area, running from northwest IA into northwest WI. Probably won`t move much tonight as it sits parallel to the mean flow. Ripples in the upper level flow will slide across/just west of the front tonight - and there lies the main focus for widespread rain and some storms. Not a lot of shear, but enough CAPE to support some strong storms. With inverted-V soundings, enhanced wind gusts the likely outcome, but good mid level lapse rates would support some hail (probably more pea to 1/2 inch). Locally, the higher threat for strong/isold severe will be north of I-94, with the CAMS focusing more on Taylor co WI. Certainly something to keep an eye on this evening. WEDNESDAY: stronger push of upper level energy slated to advance ahead of the low during the late morning/early afternoon hours, and could/should get a band of showers/storms with it. Not all models are "in" with this outcome though. That said, enough consensus to lean the forecast that way. Enough instability for storms, but not a lot of shear. Still, sub cloud dry layer persists, and enhanced gusts will continue possible. Small hail also possible. Then, later in the afternoon/evening, another round of showers/storms could shift in from IA. A lot of uncertainty on how much the atmosphere would recover, but look for around 1000 J/kg of MUCAPE, although shear remains marginal. Again, a few strong storms could result, and can`t rule out isolated severe (yet). THU-FRI: periods of mainly showers continues with the upper level low overhead. Don`t expect improvement until Friday night when the low is progged to lift north. .LONG TERM...(Saturday through Tuesday) Issued at 130 PM CDT Tue Apr 6 2021 After the kickout Fri night/Sat shortwave trough dives southeast, then rotates back over the eastern Great Lakes, the GFS and EC point to another shortwave trough dropping southeast from western Canada, moving across IA/northern IL/southern WI Sun night-Mon. Another shot of showers and storms would result. What happens to this system after Monday is sketchy. Both models suggest the northwest flow a loft would drop yet another shortwave trough toward the region. The operational EC digs this into the Mon shortwave, more or less coalescing/congealing into a retrograding closed low over the northern great lakes. That solution wouldn`t necessarily result in persistent rain chances - but would likely keep cooler than normals temps across the region. The GFS is farther west with this next shortwave, and keeps all entities separate. The upshot is that the operational GFS suggests additional rain chances Wed night/Thu. Digging into the ensemble members shows quite a mess. GEFS spaghetti plots of 500 mb flow looks like a 3 year old`s etch-a-sketch drawing with the EC also showing a wide range of possible outcomes. Confidence rather low as a result and will ride the model blend for the moment. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1054 PM CDT Tue Apr 6 2021 Current shower and storm activity continue to lift primarily to the north and is expected to stay to the west of both sites for the overnight hours. Another short wave trough is expected to rotate out of the upper level low and come across the region during the late morning and early afternoon hours. The hi-res meso-scale models have been consistent showing an arcing line of showers and storms lifting north with this short wave trough. Will continue the trend of bringing some showers across both sites with MVFR conditions with this activity. The RAP has very minimal CAPE with this so will not include any thunder for now. It looks like there should then be a break behind this activity before more starts to move in Wednesday evening. This could hold off until late evening which would be slower than currently expected. As a result, will only include a VCSH in both sites until confidence on the timing increases. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...Rieck LONG TERM....Rieck AVIATION...04
Area Forecast Discussion
National Weather Service State College PA
1028 PM EDT Tue Apr 6 2021 .SYNOPSIS... Very mild and pleasant weather will continue through midweek with a passing rain shower possible. Temperatures will trend seasonably cooler with periods of rain from late week into the weekend. && .NEAR TERM /UNTIL 8 AM WEDNESDAY MORNING/... Mostly high clouds, now, but there is a sprinkle in the Finger Lakes and perhaps will nip our NE soon. Also, an upsteam cluster of TSRA are moving steadily down toward BFD along the baroclinic zone. However, it is decreasing in intensity and will fight some drier air over the Lower Peninsula, too. New NAM has all of it dry up before it reaches PA. RAP too aggressive with convection in the next few hours from BFD-UNV, though. Very weakly forced precip is never handled well by any model. The skeptic in me says that we can`t pull all PoPs from the NW just yet, and will hold with continuity for PoPs overnight. Prev... A few radar echoes did form and are still out there, but the cloud bases were very high and the sub-cloud air pretty dry. Some 40dBZ returns could have held large enough drops to make it down to the sfc without evaporating, but maybe not. Have tweaked the temps a little milder under the cloud cover. Other changes were less notable. Best chc for the ground to get wet is over the NErn half of the CWA as pinpoint vort maxes run over the area. Prev... 18Z vis sat shows sct-bkn cumulus field to the west of diffuse frontal zone located roughly along a line from KBFD/KUNV/KRYT. Cut back on POPs for the rest of today with no CAM support and dewpoints in the 40s. There may be a few sprinkles over the southwest zones but that would most likely be the extent of precip through 00Z. The best chance for showers will be later tonight across the northeast 1/2 of the CWA as a shortwave dives southeast across the region. Low temps in the low 40s NE to around 50F SW will be +10-20F above climo. && .SHORT TERM /8 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... Upper ridging will begin to build into the region Wednesday, supplying partly to mostly sunny and unseasonably warm conditions. Forecast highs in the mid 60s to mid 70s will be +10-20F above climo. Most of the day will be dry with a couple of showers possible over the southwest 1/2 of the area. Wednesday night should remain mild and generally dry. && .LONG TERM /THURSDAY THROUGH TUESDAY/... 945 pm Tuesday update... On the large-scale, our ensemble prediction systems are in generally good agreement through the upcoming weekend. The pattern should feature short-wave ridging in the upper levels over the northeastern CONUS to start the period on Thursday, gradually giving way to falling heights into the weekend, as an upper trough digs into the Great Lakes region. As for sensible weather across the Commonwealth, this points to another mild and mainly dry day Thursday, with the prospects for showers increasing in the Thursday night-Friday time frame. Another period of showery weather looks plausible over the weekend, especially later Saturday into early Sunday. By early next week, although the customary model disagreements and levels of uncertainty are certainly there, it does seem as though a blocking upper ridge from the north Atlantic into eastern Canada will force upper troughiness to prevail from the Great Lakes into the northeastern states. This signals an unsettled, showery period, with temperatures trending cooler. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... All is going well. The wind has died off everywhere. Upstream sprinkles and even the meager convection seem to be steady state or waning a bit. Will keep on with mentions of VCSH overnight. Prev... Moisture spilling over the upper ridge over the upper Great Lakes is trying to make it to the ground. But, the llvl moisture continues to be meager. Sharp dewpoint contrast between ern PA terminals and IPT/MDT when dewpoints have risen. Warm front is right there. Cloud bases remain high with only a very small chc of a SHRA tonight, mainly along and NE of a BFD-UNV line. Curr SHRA over wrn LH could be on more of a track to get BFD and UNV wet vs IPT, where most of the mdls have the precip chc highest overnight. Still pretty dry overnight, but dewpoints do creep up into the 40s most places. Warm front doesn`t move much. Enough sun should break through Wed to make isold/sct T/SHRA over the wrn mtns and have them slide S later in the aftn. A developing east to southeast low level flow regime along with periods of rain favors some MVFR to IFR restrictions are likely from late week into the weekend. Outlook... Thu night-Sun...MVFR/IFR possible. Periods of rain. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Steinbugl NEAR TERM...Dangelo/Steinbugl SHORT TERM...Dangelo/Steinbugl LONG TERM...Jurewicz AVIATION...Dangelo/Steinbugl
Area Forecast Discussion
National Weather Service Cheyenne WY
721 PM MDT Tue Apr 6 2021 .UPDATE... Issued at 721 PM MDT Tue Apr 6 2021 Periods of snow, moderate to heavy at times, will continue through this evening, gradually tapering off overnight. Already received reports of 6 to 8 inches over far eastern WY into the northern NE Panhandle. Upgraded Winter Weather Advisory to a Winter Storm Warning for Niobrara, North Sioux and Dawes counties. Updates sent. && .SHORT TERM...(Late This Afternoon & Tonight) Issued at 229 PM MDT Tue Apr 6 2021 The main focus over the next 12-18 hours will be the potential for accumulating snowfall across east central Wyoming and the northern Nebraska Panhandle. A rather vigorous upper-level low continues to spin across northwest Colorado late this afternoon w/ an excellent fetch of mid & high-level moisture focused into these areas within the northeast quadrant of the upper low. GOES-16 IR satellite data indicates significant cooling of cloud tops in this region, within zone of enhanced low-level convergence and WAA aloft. It is rather unstable across the eastern plains today, with plenty of lightning strikes being observed with upwards of 500 J/kg of MUCAPE. Believe this could support very heavy snowfall rates into this evening and overnight as the HRRR has been very consistent with showing a very broad area 8-12 inches of snow using a 10:1 ratio. Do agree w/ the previous shifts assessment that profiles are quite warm w/ much of the saturated profile above -10 deg C, so realized ratios will end up being around 8:1 at best in the most likely scenario. Also, one other challenge is the change over from rain to snow. This already has occurred along the SD border and the Pine Ridge, as indicated/ confirmed by area webcams. However, the recent warmth may have had some impact on potential road accumulations. While it is certainly a possibility that grassy surfaces may pick up 6-10 inches of snow in the next 6-12 hours, overall impacts may remain Advisory level. After discussions with WFO Rapid City, have opted against issuance of a Winter Storm Warning for the time being. Trends will continue to be monitored and an upgrade may still be necessary if area road conditions warrant later this evening. .LONG TERM...(Wednesday through Monday) Issued at 332 AM MDT Tue Apr 6 2021 Skies will begin to clear Wednesday morning as light snow moves out of the area by late morning. Temperatures will attempt to warm back up for the rest of the week with 500 mb height rises, however looks like we will have to wait a little longer to return to the warm weather from this past weekend. Temperatures will rise up to around 60 on Thursday. Will need to keep an eye on fire weather conditions Thursday afternoon as current forecast min RHs drop below 20 percent with gusty westerly winds ahead of an approaching cold front. This cold front Thursday night will drop temperatures back down into the 40s and 50s. Limited moisture will be available with this front, but slight chance of rain/snow showers is still possible. Same story is expected into the weekend with a brief warm up before another cold front drops down from the northwest Saturday night. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 519 PM MDT Tue Apr 6 2021 Periods of light snow showers are moving through SE WY and W NE from now until around 13Z tomorrow. The snow is moving north- northeastward and is bringing MVFR to IFR ceilings and visibilities to all TAF terminals. After 13Z tomorrow, the winds will continue to gust 25 to 33 knots in SE WY and 25 to 40 knots in W NE. The wind direction has been very difficult to forecast the last few times, but it is expected to stay between westerly and northwesterly. Ceilings will stay MVFR to IFR until 17Z for SE WY and 20Z for W NE. && .FIRE WEATHER... Issued at 332 AM MDT Tue Apr 6 2021 Minimal fire weather concerns today with rain and snowfall expected for much of the area. Cooler temperatures in the 40s will be a relief after the abnormally warm and dry weather for early April this past weekend. Temperatures will briefly warm back up above normal headed into later this week. Will need to keep an eye on Thursday for elevated fire weather conditions as RHs look to drop below 20 percent and gusty winds are possible. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Winter Storm Warning until 9 AM MDT Wednesday for WYZ102. Winter Weather Advisory until 9 AM MDT Wednesday for WYZ101. NE...Winter Storm Warning until 9 AM MDT Wednesday for NEZ002-095. && $$ UPDATE...MAJ SHORT TERM...CLH LONG TERM...MB AVIATION...LK FIRE WEATHER...MB
Area Forecast Discussion
National Weather Service Grand Junction CO
636 PM MDT Tue Apr 6 2021 .UPDATE... Issued at 634 PM MDT Tue Apr 6 2021 Humidities have recovered in this cooler environment today though windy conditions will continue through sunset. Have dropped today`s Red Flag Warning and issued a Fire Weather Watch for central portions of E.Utah and W.Colorado for Thursday. && .SHORT TERM...(Tonight through Wednesday night) Issued at 335 PM MDT Tue Apr 6 2021 The mid-level low at the center of the storm moving over the area this afternoon was centered over KCAG at 21Z according to RAP analysis. As models had predicted, shower activity became more scattered as the best dynamic forcing shifted east of the Continental Divide. Meanwhile, the strong gradient around the surface low combined with deep mixing has continued to bring strong and gusty west to northwest winds to areas along and south of the I-70 corridor. Snowfall in the mountains has been pretty light with just 1 to 2 inches indicated across the northern mountains with little accumulation in the central mountains. Models were consistent in shifting the low eastward tonight with its center moving over central Kansas by sunrise Wednesday. As the gradient relaxes in the system`s wake and diurnal inversions form winds will diminish significantly with variable or light drainage flows becoming established later tonight. Clearing over eastern Utah and westernmost Colorado combined with light winds favor strong radiational cooling and expect a number of lower elevation areas will experience freezing temperatures. Areas which have begun growing in earnest have expanded in response to the unseasonable warmth experienced over the past week. Therefore, based on the numbers compiled locally, was compelled to expand the Freeze Warning into most lower valleys in eastern Utah and western Colorado. Meanwhile, residual moisture in northwest flow over the northern mountains is expected to continue to bring light snow to the Elkhead, Park, Flat Tops and portions of the Gore Ranges overnight. Additional accumulations of 1 to 3 inches are expected with locally higher amounts along the higher ridgelines. A transitory, shallow mid-level ridge moves overhead on Wednesday into Wednesday night which will bring decreasing mountain cloud cover and sunny skies elsewhere. Increased solar insolation will help temperatures recover with highs expected to peak a few degrees above normal. Winds will be lighter, but still moderately breezy across the south during the afternoon. Overnight lows will be less cold as warm air advection will be ongoing during the period, so no plans for additional freeze warnings at this time. .LONG TERM...(Thursday through Tuesday) Issued at 335 PM MDT Tue Apr 6 2021 Eastern Utah and western Colorado will remain under northwest flow into next week. A few shortwaves embedded in the flow will swing by, just clipping northern portions of the area. Western Colorado and eastern Utah will remain mostly dry as the bulk of the moisture remains well to the north. Of greater concern are the tightening pressure gradients ahead of these systems that bring the potential for gusty winds. With daytime relative humidity values expected to remain in the teens and single digits, critical fire weather conditions will be possible for the end of the week and in as to the weekend. Models are in good agreement that the first shortwave will move past on Friday, and the second on Sunday. Confidence in the forecast for the beginning of the next work week is lower, though in general the flow aloft will remain northwesterly and there is potential for another disturbances to drop in on Tuesday. Temperatures through the period will bounce around a bit, dropping 5- 10 degrees with the passage of each shortwave and then rebounding the next day. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 524 PM MDT Tue Apr 6 2021 Showers and clouds will be dissipating by sunset with the winds lowering not long after as well. VFR conditions will dominate the forecast over the next 24 hours with less winds expected on Wednesday. && .FIRE WEATHER... Issued at 335 PM MDT Tue Apr 6 2021 Overall wind speeds will decrease, but post-frontal flow will keep winds gusty across southeast Utah and southwest Colorado into the evening. Dew points will not recover much in these areas so Red Flag conditions are still likely until 9 PM. Not much changes Wednesday except that temperatures will be warmer, so expect the Hwy 160 corridor is likely to reach critical levels once again so upgraded the Fire Weather Watch to a Red Flag Warning for areas below 8000 feet in the Four Corners region. The jet builds back northward on Thursday and warm temps mean dry surface conditions spread across the region. Critical fire weather looks possible once again near and along most of the CO/UT state line on Thursday. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...Fire Weather Watch from Thursday afternoon through Thursday evening for COZ202-203. Freeze Warning from midnight tonight to 9 AM MDT Wednesday for COZ006-007-011-020-021. Red Flag Warning from noon to 9 PM MDT Wednesday for COZ207-295. UT...Fire Weather Watch from Thursday afternoon through Thursday evening for UTZ490. Freeze Warning from midnight tonight to 9 AM MDT Wednesday for UTZ022-024-027. && $$ UPDATE...15 SHORT TERM...NL LONG TERM...BGB AVIATION...TGJT FIRE WEATHER...TGJT
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
713 PM CDT Tue Apr 6 2021 .UPDATE... Issued at 642 PM CDT Tue Apr 6 2021 Updated to include 00z aviation discussion below. && .SHORT TERM...(This evening through Wednesday night) Issued at 400 PM CDT Tue Apr 6 2021 WAA showers/storms developing this afternoon are the beginnings of what will be a very wet next few days. The upper system of interest is the closed h5 low over CO/WY that by 12z Thursday will have deepened some, taken on a negative tilt and traveled to northeast MO. We`ll be in a very diffluent mid/upper flow pattern to the northeast/north of the low, which means ample upward motion for precipitation generation. At the surface, there is a stationary front snaking from about Springfield, MN, to the southeast Twin Cities metro, and up to near Ladysmith. This front will move very little during the short term, with a surface low eventually working up along it and into southeast MN by Thursday morning. During this period, a threat for severe weather will exist pretty much the entire time near the boundary. Limiting factor for severe weather today is lack of mid level flow. We`ve got decent low level shear with the boundary in the area, but the weak flow aloft has left us with short hodographs. We do have 1500-2000 j/kg of muCAPE in the warm sector, so enough instability for some isolated incidences of severe hail and maybe a wind gust, but not much more than that. For Wednesday, a threat for severe weather will continue, but we`ll loose the EML and associated steep mid-level lapse rates, so less instability to go with a slight increase in shear. For Wednesday the severe threat near where the boundary ends up can be best described as low, but not zero. For PoPs/QPF, followed something close to a blend of the CAMs. This has pretty high pops along and northwest of the front through tonight, with lower values from Albert Lea up through Eau Claire, where drier mid-level air will cut back on precip production. Some longer dry periods are expected across southwest and south central MN on Wednesday as another dry slot slides up into southern MN, with another round of fairly widespread precip expected to move back across the area Wednesday night. In the end, the CAMs are all pretty similar with 2 to 3 inches of rain falling in just the short term period for areas west of the stationary boundary, with some higher embedded streaks. .LONG TERM...(Thursday through Tuesday) Issued at 400 PM CDT Tue Apr 6 2021 With the closed low pressure system stalled over the Midwest, Thursday into Friday look wet for our region. Continued 850 mb WAA around the northern periphery of the low will create a TROWAL wrapping counter-clockwise from WI across MN and into northern IA. Thus, rain will occur along this feature into Friday afternoon as the low slowly migrates northeast while weakening. The upper-level pattern will play billiards Friday into early next week as continued southeastward moving troughs from western Canada are forecast to become cutoff from the northern jetstream and "kick out" preceding closed lows over the Midwest. This upper-level behavior is due to a strong ridge situated over the the northern Atlantic Ocean/Greenland causing the northern jetstream to bend far northward over the Arctic. Any troughs in western Canada that dive southeast into MT/ID/WY will cutoff and slowly stall out in the split flow over the central CONUS. Indeed, the closed low affecting us into late week will finally be punted northeast into Ontario by another closed low shifting into the Central Plains. An additional 1- 1.5" of rain is possible over western MN by Friday evening with lesser amounts east. Fortunately, the long duration of rainfall and our dry soil should mitigate flooding concerns. Have also toned down Thursday and Friday`s highs to NBM 50th percentile due to expected cloud cover. Saturday and Sunday look relatively dry for our region as the aforementioned closed low in the Central Plains currently appears too far south to affect us. Slight chances of precipitation are possible early next week with rounds of cutoff lows rotating through the Upper Midwest. However at this time, location and timing differences within the guidance owes to low predictability. What is more certain heading into next week is cooler air continually being advected into the Northern Plains by the "cutoff low train". Thus, we may very well see a return to below normal temperatures by mid-next week. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 642 PM CDT Tue Apr 6 2021 Tricky TAF set due to the uncertain timing of precip in/out of the terminals, particularly TS. This is all being caused by a nearly stationary frontal boundary oriented NE-SW over southern MN into western WI, and this front is expected to generally remain in place through the entire TAF period. Have utilized a mainly HRRR look to time in the convection but there will be more rain time than dry time throughout this TAF set. Ceilings will mainly run VFR through this evening with occasional MVFR visibility due to the passing RA/TSRA. However, going into the overnight hours, chances increase for MVFR ceilings area-wide with MVFR ceilings likely at all TAF sites by daybreak Wednesday. Ceilings may also dip into IFR range for several hours during the day Wednesday. Best shot at TSRA will be this evening into the early morning hours then generally RA expected on Wednesday with more sporadic TSRA. The other issue will be wind directions, which will be entirely dependent on where the front settles. So, wind directions in eastern MN into southern MN may be subject to frequent wind shifts. Overall, a fairly good amount of variance should be allowed and amendments may be fairly frequent. KMSP...Intermittent RA/TSRA is expected from this evening through the early morning hours as several waves of precipitation move north through the Twin Cities. A few rounds of TS likely this evening with diminishing chances of TS going into the early morning hours and the rest of Wednesday. Have held off TS mention beyond 12z at this point but it would not be surprising to see additional mentions of TS through the day Wednesday as TS potential extends throughout this TAF duration. Wind directions likely to run N to E overnight then continue veering to SE and S through the day tomorrow with MSP likely to be on the E side of the front. But, still some chance of seeing more varied wind directions which, when combined with the dropping ceilings, could impact runway operations. /OUTLOOK FOR KMSP/ THU...MVFR/-SHRA. Chc IFR. Wind SE 5-15kts. FRI...MVFR. Chc -SHRA/IFR. Wind W 5-10kts. SAT...MVFR. Chc -SHRA. Wind NW at 5-10kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ UPDATE...JPC SHORT TERM...MPG LONG TERM...CTG AVIATION...JPC
Area Forecast Discussion
National Weather Service Riverton WY
235 PM MDT Tue Apr 6 2021 .SHORT TERM...Tonight through Wednesday Night As of 1pm, the low center is located just to the east of the WY/UT/CO border and is continuing to move eastward this afternoon. Precipiation bands continue to spiral over the region, mainly east of the Divide. Temperatures are hovering just above freezing in many areas so snow that is falling is not sticking to the ground or is melting as it falls. Some locations continue to see all rain and are not expected to switch over to snow if they have not yet done so. The Winter Weather Advisories for the western mountains expired on time this morning and the only one remaining for the Bighorns will expire on time at 3pm. Models are holding onto precip a little longer than previous runs, especially east of the Divide, but the low will continue to move east and things will clear out quickly when the precip ends. With precip and clouds moving out quickly after midnight, there likely will be widespread patchy fog overnight across the region. If a significant cloud deck hangs on and winds stay up, this will be less of a concern, but model soundings are indicating a pretty decent fog signature beginning after midnight for many locations. This signature is most notable in the NAM, but the HRRR and SREF also hint at a fog signature. GFS MOS guidance is also picking up on fog, particularly for the Green River basin, Jackson Valley, and Cody. Behind today`s trough, ridging moves back into the region, bringing quiet weather for tomorrow. By sunrise, most areas will see clouds scattering out to mainly clear skies by noon. Temperatures will recover into the 50s for most areas and 40s across higher elevations tomorrow afternoon. Tomorrow night will see temps drop into the 20s and low 30s with mainly clear skies. Winds, which remain breezy today, will also diminish tonight and will be mainly light tomorrow, so no concerns there. The nicer weather will continue into the extended forecast period. .LONG TERM...Thursday through Tuesday A fast moving, progressive pattern will be the rule for the first few days. A Pacific trough / cold front will enter northwestern Wyoming late in the day and swing across the state at night. A vast majority of the day should be precipitation free though with near normal temperatures. Thinking remains similar to yesterday, with rain and the snow showers across mainly the northern portions of the state. There is not a ton of moisture associated with it and given the fast movement, any snowfall amounts continue to look sub advisory at this point. The big impact may end up being strong wind given the favorable northwest flow and cold advection pattern. The main areas that would have impacts would be the Big Horn Basin, Johnson County and the Wind River Basin. However, 700 millibar winds continue to not look sufficient for high wind highlights from later Thursday night into Friday. We did bump up winds somewhat, since the national blend usually does a horrible job capturing these effects. Any leftover showers should end Friday morning. Following that another transitory ridge will build in and bring around a 36 hour period of dry and seasonable weather. There will be some breezes around though given the fast flow however. Then the next wave moves into the northwest later Saturday. But again, a vast majority of the area should remain dry through the daylight hours. And like the previous one, moisture amounts are modest so at this point snowfall amounts look to remain sub advisory once again. The main impact once again may turn out to be strong winds in the similar northwest flow areas, mainly the Big Horn Basin, Johnson County and the Wind River Basin. Uncertainty then ramps up considerably toward the start of the new work week. The GFS is showing very poor run to run continuity with the storm of Monday now gone. Given the differences in models, we made few changes to continuity and did not spend a lot of time on it given more pressing concerns closer to the present day.&& .AVIATION...for the 00Z TAFS through 00Z Thursday West of the Divide...KBPI, KJAC, KPNA, and KRKS... Most precipiation has wrapped up with the exception of KRKS which continues to see showery precipitation off and on. MVFR cigs will continue at KRKS, as well as KBPI, KJAC, and KPNA off and on through about 06Z before becoming VFR through the rest of the period. Patchy fog is possible at all sites once cigs lift and winds begin to diminish. KRKS has the lowest chance of fog because winds will remain gusty through the night. Any fog that forms will dissipate after 14Z to 15Z and VFR with mainly light winds will prevail through the rest of the period. KRKS will see the breezy conditions continue through the period. East of the Divide...KCOD, KCPR, KLND, KRIW, KWRL... All terminals will continue with MVFR to IFR conditions with off and on snow showers through 06Z. KCOD, KLND, and KRIW will see VFR and increasing cigs beginning around 03Z while KCPR and KWRL will not see conditions improve until 06Z to 09Z. As cigs lift and scatter, patchy fog will be possible at all sites through 15Z. VFR conditions and scattered high clouds will prevail for the end of the period with mainly light winds. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on icing and turbulence forecasts. && .FIRE WEATHER... Rain and snow showers will taper off and end tonight. High pressure will bring a dry day on Wednesday with near normal temperatures. There will be breezy conditions from eastern Sweetwater County across southern and western Wyoming on Wednesday, but strong winds are not expected. Wind should remain light to moderate elsewhere. Relative humidity should remain above critical levels. Mixing and smoke dispersal will range from poor to good in northern Wyoming to very good in southern Wyoming. && .RIW WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Fisher LONG TERM...Hattings AVIATION...Fisher FIRE WEATHER...Hattings
...Update to aviation forecast discussion...

.DISCUSSION... Issued at 320 PM CDT Tue Apr 6 2021 Strong to severe thunderstorms move through the region this evening/tonight, with large hail and damaging winds the main threats. Otherwise look for a seasonal and quiet forecast. Elevated convection worked across the forecast area this morning and early afternoon, bringing light rain to most locales and moistening the lower BL in advance of our main event this evening. Daytime solar insolation helped slow the rate of decay of these showers, with even a few thunderstorms redeveloping along the western flank of the convective cloud shield early this afternoon. However, this complex should continue to slide eastward and pose little in the way of a threat. Water vapor imagery shows a compact, negatively-tilted upstream shortwave/low centered across the UT/WY/CO border region, which will be the driver for the main convective show this evening. Return southern flow is well-established ahead of a surface cold front (visible in satellite imagery) that stretches N to S over western Kansas, producing temperatures in the upper 70s to low 80s and dewpoints in the upper 50s to low 60s. Stable billow clouds have given way to more convective cumulus fields near the frontal boundary, an indication of destablilzation in the BL. The approaching upper trough should steadily erode the H700 cap over the next few hours and result in convective initiation in central Kansas towards the 22-00Z timeframe. CAM guidance is in good agreement in the general timing and progression of the convection through the evening. A modest line- parallel, storm-relative effective shear component and complex mid- level hodograph structure should result in quick upscale growth to multi-cell clusters and eventually a line as the convective cold pool becomes established amidst DCAPE values of over 1000 J/kg. Thus, expect that the threat will transition to wind with severe hail possible with stronger updrafts. The threat for tornadoes is non-zero towards central Kansas towards sunset with 0-1 km SRH values of 300-400 m2/s2, but the aforementioned issues with the mid-level hodographs--resulting in competing updrafts and lower effective shear values--will certainly not aid in sustained mesocyclone growth. The cold pool surges E/SE through the early overnight hours, reaching the Topeka area a little bit before midnight. Recent HRRR runs have E-W up-shear development along the interface of the LLJ behind this initial wind surge, thus we will also need to monitor the threat for heavy rain/flash flooding throughout the night along and south of I-70 with any training storms. The trailing stratiform precipitation shield lingers through the rest of the night and into the morning on Wednesday. The upper low dives into western Kansas by 12Z Wednesday. The attendant dry slot wraps around the southern and eastern flanks of the low by mid-morning, which may temper the threat of rainfall in eastern portions of the forecast area during the morning hours. Renewed convective development is expected along the cold front as it lifts northeastward through far eastern Kansas. While the best threat for storms, and even a few tornadoes, will be further east into MO, will still need to monitor trends in the timing of the front/upper wave as the ribbon of 60 degree dewpoints is still very close to the eastern CWA border at 18Z Wed based on the HRRR. The upper low slows as it becomes the western flank of a eastern Great Lakes/Appalachian omega block. Multiple perturbations wrapping around the cyclone keep cool, cloudy, and damp weather through the day on Wednesday and even into Thursday in far NE Kansas. Clouds start to clear in central Kansas late Thursday, allowing temperatures to warm back up into the 60s for highs. A narrow ribbon of warmer air preceding our next cold front boosts highs into the low 70s for Friday, but the cold front moves through in the early afternoon and keeps the bulk of any convection southeast of the forecast area. The weekend looks to be quite nice with highs in the upper 60s to mid-70s and with the threat of any showers coming late Sunday into Monday as the next northern stream wave in the caravan approaches from northwest. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 640 PM CDT Tue Apr 6 2021 Thunderstorms anticipated to arrive as early as 03-04Z time frame right now but could be delayed. Threat should be mostly brief heavy rain transitioning to moderate rain and wind. Thinking a short window for LLWS ahead of these storms appears to be very short, and with slightly stronger surface winds still in place, have decided to not include at this time. Showers and storms tonight should maintain MVFR categories but additional wrap around showers and cooler air into the early morning hours are expected bring CIGs down to low MVFR and dip into IFR levels. Showers could linger much of the day over the terminals and would be light. Right now this idea is reflected in the KMHK forecast but may need to be spread east into the KTOP/KFOE terminals for the next forecast update. && .TOP WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 8 PM CDT this evening for KSZ008>012-020>024- 034>039-054-055-058. && $$ DISCUSSION...Skow AVIATION...Drake
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
923 PM MDT Tue Apr 6 2021 .UPDATE... Issued at 918 PM MDT Tue Apr 6 2021 Have continued to tweak Advisory/Warning area as storm evolves through the evening. Small but potent band setting up along foothills...with reports of 2"/hr snowfalls being reported near westside of Rapid City. Appears to be associated with last bit of 700hpa theta-e forcing. Have updated hazard grids to place foothill zones into advry through 08z. Satellite trends show a quick diminishing taking place as dynamics shift to the east with convection across ern parts of NE and KS. Of interest is the latest run of the HRRR showing warning criteria snowfall now by morning across Todd/Tripp counties. They are currently in a winter weather advisory for 3-5" of snow and will let that ride for now. UPDATE Issued at 614 PM MDT Tue Apr 6 2021 Several little details to pay attention to this evening. Updated fcst earlier to put Fall River county into the winter storm warning. Webcams continued to show heavy snow falling in county, and calls placed verified heavy snow falling. 21z RAP40 and latest HRRR show 700hpa theta-e forcing still in play across the far SW part of the state along with ample moisture advection providing for efficient snow making machine. Lastest HRRR wants to put 12" snow in far SW CWA. Next item on convection firing in central Nebraska moving to north. Warnings and statements have been issued on these storms as they move north on 700hpa jet. 0-3km SRH slightly favorable for cont development in Todd/Tripp will need to continue to watch && .DISCUSSION...(This Evening Through Tuesday) Issued at 254 PM MDT Tue Apr 6 2021 Potent mid-to-upper-level vort max centered over nwrn CO is evident on WV imagery this afternoon, with deep moisture extending enewd across WY/SD. Satellite-derived layered PWATs indicate that a steady stream of low-to-midlevel moisture is being transported around the developing 850/700 mb cyclone toward nern WY/swrn SD, with moisture convergence generally maximized in the vicinity of the srn Black Hills. Analysis suggests an enhanced area of low-level fgen extending from near the Black Hills newd through cntrl SD, with midlevel fgen slightly offset to the NW and associated with a band of deformation rotating around the upper low. Relatively dry air aloft is detected S/E of this fgen, while relatively dry low-level air persists over portions of the nwrn SD plains, with dew point depressions near or over 20 degrees in portions of Perkins, Meade, and Ziebach counties. Upper low should gradually shift ewd and weaken thru the evening. Despite an expected weakening trend, moisture advection/convergence along a TROWAL axis extending into nern WY and forcing along the zones of fgen/deformation should continue to support heavy stratiform precip from srn portions of nern WY thru the Black Hills/swrn SD and into cntrl SD into the evening. Additionally, elevated buoyancy/CAPE should continue to promote some convective elements, both within the broader precipitation shield and along its srn periphery, where thunder rain/snow showers have been ongoing this morning and early afternoon. As cyclone weakens this evening into tonight, forcing and associated precip should gradually wane from west to east, though precip will likely linger into tomorrow across s cntrl SD. Tough decision on headlines for this afternoon and evening, but decided to expand winter weather advisory into the srn foothills and Weston Co. plains. Certainly plausible, if not likely, that some locations in Weston/Fall River Co. will end up with over 6 inches of snow on grassy sfcs. However, webcams across the area show relatively limited impacts on roadways thus far, with only minor slushy accumulations despite rather consistent and heavy snow for the last couple of hours. Based on large-scale moisture advection and Froude numbers/wind directions near the hills, enhanced convergence along the swrn/srn peripheries of the hills may continue for several more hours. If snowfall rates over the last couple of hours persist into the evening, more significant travel impacts may develop, particularly after dark, which may require a reevaluation of existing headlines there. Winds/Froude numbers also appear marginally favorable for upslope enhancement along the nrn/nern foothills this evening. However, given the delayed onset of snow and model trends that suggest a rapid erosion of deep moisture across nwrn SD this evening as the cyclone weakens, opted to not introduce any headlines in these locations at this time. Near-normal temps tomorrow as precip wraps up. Warm and dry again on Thursday ahead of our next cold front, which should arrive Thursday night into Friday. Boundary layer winds and pressure rises suggest this should be a breezy/windy frontal passage that may require headlines. Could see some light precip, but it appears that this frontal passage will be fairly dry (at least compared to the current system). Rinse and repeat for the weekend: warm Saturday, followed by another mostly dry frontal passage. && .AVIATION...(For the 00Z TAFS Through 00Z Wednesday Evening) Issued At 614 PM MDT Tue Apr 6 2021 MVFR/IFR cigs/vsbys will continue over terminal locations through most of valid fcst period. Look for gusty northerly winds to continue overnight...diminishing during the day Wednesday. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...Winter Storm Warning until midnight MDT tonight for SDZ024-028- 029. Winter Weather Advisory until 6 AM MDT Wednesday for SDZ042-044. Winter Storm Warning until 6 AM MDT Wednesday for SDZ027-041. Winter Weather Advisory until 2 AM MDT Wednesday for SDZ026-072- 074. WY...Winter Storm Warning until midnight MDT tonight for WYZ057. Winter Storm Warning until 6 AM MDT Wednesday for WYZ058. && $$ Update...Hintz DISCUSSION...Sherburn AVIATION...Hintz