Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/07/22

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
635 PM EST Tue Dec 6 2022 .AVIATION... Increasing upper level jet forcing across the central Great Lakes region has led to a brief episode of elevated frontal forcing from central Lake Huron southwestward to WI/IL border. As the forcing passes to the east, a weak cold front will slip southward tonight between 05-8Z. Onset of cold air advection will lead to increased low level saturation, drizzle and potentially IFR cig heights. Have refrained from going more aggressive with IFR for this taf issuance but will monitor model/obs trends this evening. Lack of strong gradient flow Wednesday with persistence of higher RH below 875mb supports MVFR/VFR overcast for much of the day. For DTW... DTW THRESHOLD PROBABILITIES... * High for ceilings at or below 5000 ft * High for ptype as rain tonight. && .PREV DISCUSSION... Issued at 348 PM EST Tue Dec 6 2022 DISCUSSION... Dry but cloudy mid to late afternoon conditions give way to another round of banded precipitation inbound from the west this evening. Patches of light rain and or drizzle are possible over the entire SE Mi area as the surface front settles south of the IN/OH border while the primary band of rain holds mainly north of I-69. Likely range POPs remain warranted in that area as a textbook mid level frontal circulation stays active while traversing central Lower Mi. A survey of 12Z model analysis and cross section forecast fields indicate strong fgen forcing associated with a 130+ kt upper jet that is favorably aligned SW to NE over the mid level frontal zone. The secondary circulation cycles through intensity variations in a nearly unstable profile judging by the most recent RAP theta-e cross sections through the 700-500 mb layer. This points to an even stronger vertical motion response compared to the morning band with perhaps a slightly farther north drift on the band location. Afternoon surface observations also support model soundings that indicate an all rain event across the area. RAP/HRRR/ARW soundings all show freezing level holding well above 2500 ft with several degrees of above freezing cushion on surface temperatures. HREF FRAM output has just a few speckles of freezing rain possible in the higher terrain north of Midland/Bay counties which is consistent with the weak push of cold air in the diffuse large scale surface pressure pattern. A push of slightly stronger gradient wind is possible late tonight which carries temperatures down to near freezing north of Flint but not before the rain band slides eastward prior to sunrise. Upper jet forcing shifts eastward and short wave forcing shifts northward which allows the low level frontal zone to dissipate during Wednesday. Surface high pressure then gains a foothold in the Great Lakes by Wednesday night to reinforce a dry weather pattern but struggles to dissipate clouds into Thursday. Any decrease in low clouds early Thursday is quickly replaced by thickening high clouds ahead of the next low pressure system. Medium range projections in today`s 12Z model cycle maintain solutions that bring today`s southern California low pressure system into the Midwest by early Friday. There is reasonable agreement on the track and strength of the short wave as it is kicked eastward by next round of Pacific jet energy with the mid level circulation reaching the south end of Lake Michigan by Friday afternoon. Model variations are greater with the magnitude and placement of the QPF axis which also feeds into precipitation type expectations. The ECMWF is reasonable representation of consensus among the deterministic solutions considering the short wave is forced to shear eastward during the day Friday. Surface temperature guidance is well above freezing during the day while NAM and GFS model soundings are closer to a snow sounding. For now, a high POP rain/snow mix with some light accumulation looks like a good start while keeping a close eye on temperature trends. Strong surface high pressure over northern Ontario and Quebec is poised to have a colder influence on the low level thermal profile likely requiring refinements to the proportions of rain and snow in upcoming forecasts. Additional short wave energy follows the Friday system into next weekend, however the large scale upper jet pattern keeps any substantially cold air confined to the north. A light rain/snow mix is once again possible centered around Saturday night while temperatures hover around normal values near 40 during the day and near 30 at night. MARINE... A frontal boundary over the Central Great Lakes will wash out, leading to light northerly winds through tomorrow. Strong high pressure building into northern Ontario in the evening will likely lead to a modest increase in winds over Lake Huron, but veering around to the northeast and then east, with gusts up around 20 knots by Friday morning. Low pressure coming out of the Midwest on Friday will increase the pressure gradient further and easterly winds gusting 25 to 30 knots should be no problem, along with rain and snow overspreading the region during Friday. Sufficient cold air in the low levels to support possible low end gales across the central and norther sections of Lake Huron. As the low pressure systems lifts north Friday evening, winds will diminish from south to north Friday night into Saturday, Winds then increase for the second half of the Weekend, as low pressure transfers to the East Coast, but it appears winds should remain comfortably under 30 knots. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ AVIATION.....CB DISCUSSION...BT MARINE.......SF You can obtain your latest National Weather Service forecasts online at
Area Forecast Discussion
National Weather Service Quad Cities IA IL
904 PM CST Tue Dec 6 2022 .UPDATE... Issued at 859 PM CST Tue Dec 6 2022 A problematic forecast is in place tonight, as the potential for dense fog remains high in any clear area, which was expanding over the area through 7 PM. However, despite the 00z DVN sounding showing drying in the layer of the stratus, the patches that were isolated at sunset, but now cover a growing percentage of the CWA, and by 9 PM, we now are seeing the majority of the area covered by stratus. While this is a problem for aviation, the stratus will help abate any dense fog formation through the night. I`ll leave the potential in the forecast through, as any hole will quickly see dense fog formation through mid morning Wednesday. && .SYNOPSIS... Issued at 230 PM CST Tue Dec 6 2022 As of 2 PM, radar was showing a narrow band of mainly virga and sprinkles along a line from Fairfield to Rockford. Some light sprinkles were observed by a NWS employee just before 2 pm. The air in place is dry with high cloud bases, but the HRRR has been indicating some slight intensification of the band which may be enough to squeeze out some more sprinkles or even some brief light rain. This potential is expected to wane and move east of the CWA by late afternoon or early this evening. Otherwise, mostly cloudy skies were common with some clearing working into the western portions of the CWA. Temperatures were in the upper 30s to mid 40s with dew points in the upper 20s and 30s. && .SHORT TERM...(This evening through Wednesday) Issued at 230 PM CST Tue Dec 6 2022 Key message: Patchy fog possible late tonight into mid morning; possibly resulting in slick roads Tonight, high pressure will build into the area bringing decreasing cloud coverage and nearly calm winds. Western areas will see mostly clear skies while clouds may hold across areas along and east of the MS River. Some patchy fog is possible after midnight tonight which may linger through the Wednesday morning commute. Some locally dense fog is possible, with visibility under a quarter mile. With temperatures forecast to drop into the 20s to lower 30s, the increased humidity levels and fog potential may result in slick spots on roads; especially bridges and overpasses as they freeze up faster. This will be something to watch this evening and tonight for the possible need for an advisory headline. Wednesday, the light and variable or calm winds will continue as the high pressure remains over the region. Any fog is expected to dissipate around mid morning, leaving a mix of sun and cloud cover. Temperatures are forecast to reach the upper 30s and lower 40s north with mid and upper 40s south. If any fog or low level clouds linger, it may be cooler. .LONG TERM...(Wednesday night through Tuesday) Issued at 230 PM CST Tue Dec 6 2022 A late week storm system with minimal impacts. Temperatures generally at or slightly above normal with a stronger storm system around the middle of next week. Wednesday night through Friday Assessment...high confidence on a storm system. Medium confidence regarding timing of precipitation. The next storm system will move through the Midwest very late Wednesday night through Friday morning. Mainly dry conditions will be seen Wednesday night but some sprinkles may develop in the pre-dawn hours across the far south. On Thursday rain will overspread the area from south to north during the day. The dry low level northeast flow could slow the northward advancement of the rain but the strong push of moisture aloft will eventually win out. Cooling of the atmosphere during the onset of the rain may briefly result in a rain/snow mix but any accumulation will melt on contact. Thursday night is the main push of precipitation with the storm system. Rain will be seen during the evening hours with a potential rain/snow mix in the highway 20 corridor. After midnight things get interesting. The rain will slowly cool the atmosphere in the highway 20 corridor allowing the rain/snow mix to `possibly` change over to all snow. Thermal profiles of the atmosphere are marginal for this to occur but it cannot be ruled out. If a change-over to all snow occurs any accumulations would be north of highway 20 and probably a dusting at best. A possible inch of accumulation `may` occur along a Fairbank, IA to Balltown, IA line. A very tight gradient is expected on the southern edge of the snow. North of a Fairbank, IA to Warren, IL line accumulation amounts will quickly ramp up over the short distance of 10-20 miles. On Friday a lingering rain or rain/snow mix will end from west to east during the morning followed by dry condition in the afternoon. Friday night through Sunday Assessment...high confidence Quiet and dry conditions will be seen across the area as high pressure moves through the Midwest and into the eastern Great Lakes. Temperatures are expected to be around or slightly above normal. Sunday night through Tuesday Assessment...high confidence on a storm system in the mid-CONUS. Low to medium confidence on timing and potential impacts. All global models develop a strong storm system next week. As expected there are differences (some significant) regarding storm evolution and timing. The deterministic ECMWF keeps the area dry through Monday night with rain moving into the area on Tuesday. The system tracks from northeast Colorado into the Dakotas before occluding and then moving east. The EPS has very light precipitation as soon as late Saturday night and continuing through Tuesday. The better rain chances are favored Monday night/Tuesday. The deterministic GFS has a dry Sunday night with precipitation developing Monday into Tuesday. The system tracks from western Kansas into Western Minnesota. The GEFS develops precipitation Saturday night with it continuing through Tuesday. However the better precipitation chances favor Monday into Tuesday. The deterministic CMC global is dry Sunday night through Monday night with precipitation developing Tuesday. The system is slower but tracks through central Iowa and into Wisconsin. The CMCE develops precipitation Sunday night and continues through Tuesday. The better rain chances are favored Monday afternoon into Tuesday. Given the differences between the models and their respective ensembles, they do agree on two things: 1) there will be a strong system system developing and 2) it will generally track west of the area. The model consensus has chance pops Sunday night, chance to likely pops Monday followed by likely pops Monday night and Tuesday. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 516 PM CST Tue Dec 6 2022 While conditions at 00z will be mainly VFR, there is some MVFR stratus in patches over the area, and these could be in place, especially near CID into the evening. Otherwise, the light wind flow, and moist low levels will allow for fog potential to grow through the night, with possible LIFR dense fog at all sites from 09z through 15Z...which may linger a long time into Wednesday given the light winds. Expect potentially a prolonged poor flying weather forecast into late Wednesday should the dense fog develop. ERVIN && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...Ervin SYNOPSIS...14 SHORT TERM...14 LONG TERM...08 AVIATION...Ervin
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
957 PM EST Tue Dec 6 2022 .SYNOPSIS... Periods of rain continues mainly over the mountains and foothills through Friday. A cold front crosses our area to start the weekend with drier conditions behind the front and temperatures returning to near normal for this time of year. A strong cold front may approach from the west early next week. && .NEAR TERM /THROUGH WEDNESDAY/... As of 950 pm EST Tuesday: Visibilities continue to bounce around across the forecast area late this evening, but with the Dense Fog Advisory area across the foothills/Piedmont still generally well- placed with observations reporting 1/4 to 1/2-mile visibilities at times. The mountains remain even more variable, with visibiities ranging from 3/4 mile to 5+ miles. Will continue to ride on the existing SPS across the mountain counties until any clearer trends for overnight fog/visibility develop. The general approach is to prefer low stratus with patchy dense fog over the high terrain and areas of dense fog east of the mountains. Regional radars are starting to show a modest uptick in light precipitation coverage late this evening in and near the southwest mountains where improving low-level south to southwest flow is producing more upglide. Expect coverage to continue to increase from the west overnight and through Wednesday morning as 500 mb vorticity lobes bring better DPVA. Will feature the highest PoPs over the mountains and stretch out improved light rain chances along and north of I-40 early Wednesday. Lows tonight will be some 15-20 degrees above normal, with most locations seeing an evening low with hourly temperatures then rising a bit overnight. Short term guidance continues to predict slow erosion of the wedge through Wednesday, with NAM and RAP profiles featuring a significant low-level inversion even as late as early afternoon. Isentropic ascent should weaken, but CAD erosion is often slower than forecast so will hedge a bit cloudier and toward cooler temps than guidance. Assuming erosion does occur at some point, Wednesday`s highs should reach 10 to 12 degrees above normal. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... As of 205 pm Tuesday: Much of the forecast area is expected to become solidly warm-sectored during mid-week, as a cyclone lifts from the lee of the Rockies into the upper Miss Valley by Fri morning. The leading edge of a baroclinic zone will nevertheless loiter near the periphery of the CWA through the period, warranting an extended period of mostly chance PoPs in/near those areas. By the end of the period, the model guidance is in generally good agreement in sending the boundary back into the area through the back door, as low level high pressure is reinforced over the northeast Conus in the wake of a short wave trough. Meanwhile, another section of the front will approach the region from the TN Valley as aforementioned cyclone (in a weakening phase by that point) moves into the Ohio Valley. This warrants an increase of PoPs to the likely range, mainly across western and northern areas by the end of the day Friday. Temps will generally be well above normal through the period, except perhaps across northern areas Friday, where fropa may occur early enough to yield near-normal maxes. && .LONG TERM /SATURDAY THROUGH TUESDAY/... As of 215 pm Tuesday: Global model guidance is in generally good agreement that cold air damming will develop across much of the area over the weekend in the wake of short term back door cold front. There`s little signal for an organized precip through at least early next week...certainly not on a model consensus basis. However, moisture within a general weak upglide regime associated with the CAD regime...followed by an eventual return to warm sector conditions as the CAD weakens, and a major cyclone develops over the Great Plains, justifies some PoP mention through the period. The moist CAD regime will generally support max temps near to slightly above normal, and min temps a category or two above climo through much of the extended. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... At KCLT and elsewhere: LIFR to VLIFR conditions should be fairly persistent at all sites except perhaps KAVL overnight into Wednesday morning. Periods of dense fog and cigs down near airfield minimums are quite possible at times given the slowly shallowing cold wedge in place atop the region. Will also feature slower than guidance improvement in conditions through Wednesday given the typical difficulties we have in scouring shallow damming without a decent downslope flow. A brief window of lower MVFR late tomorrow is probably the best we can hope for at most TAF sites. Will feature mainly drizzle and light rain through the period to go with the periods of fog, with the best chances overnight through Wednesday morning. Light winds will be calm to variable tonight but see a steadily increasing S to SW flow through Wednesday with the slow CAD erosion. Outlook: Unsettled weather and associated flight restrictions will continue on and off through Friday. Temperatures will mostly be above normal, so no wintry precip is expected at any of the terminals during this time. The trend becomes drier on Saturday, but uncertainty remains in the weekend forecast. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...Dense Fog Advisory until 10 AM EST Wednesday for GAZ017-018- 026-028-029. NC...Dense Fog Advisory until 10 AM EST Wednesday for NCZ035>037- 056-057-068>072-082-502-504-506>510. SC...Dense Fog Advisory until 10 AM EST Wednesday for SCZ008>014- 019-101>109. && $$ SYNOPSIS...DEO NEAR TERM...HG SHORT TERM...JDL LONG TERM...JDL AVIATION...HG
Area Forecast Discussion
National Weather Service Gray ME
1053 PM EST Tue Dec 6 2022 .SYNOPSIS... Rain will continue to spread east tonight with the precipitation continuing on Wednesday as a weak area of low pressure crosses New England. Canadian high pressure builds into New England to end the work week. A mix of rain and snow showers then return for the weekend, as low pressure develops off the Mid Atlantic coastline. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 1050 PM Update...Waves of rain will traverse the forecast area from southwest to northeast overnight and PoPs are in good shape. Overall, forecast hasn`t needed much change, just a few minor adjustments here and there. Winds will be gusty on the W/NW slopes of the Whites as the southeasterly LLJ downslopes. Previously... 6pm Update...Mostly a discussion update as forecast changes were small. SE flow continues over the ME/NH seacoast. Temps are holding fairly steady amid this warm/moist flow. Did increase winds a bit over the western higher terrain as obs sites occasionally gust over 20 mph and higher peaks likely in a more breezy layer than the lowlands. MRMS RALA cuts away a lot of the elevated shower returns in the area, and hones in on a few patches of rain now moving across southern NH and from the foothills to coastal ME. A lot of the continuous rain has been mainly north of the international border. HRRR and NAMnest runs both agree with these rain shower continuing intermittently through much of the evening and overnight, with a more concentrated plume of rain moving through the area come early Wed AM. A weak area of low pressure will approach from the west tonight. This will spread precipitation across the region from west to east. The ptype will mainly be rain, however some mixed precipitation is possible across the highest peaks. Eastern portions of the forecast area will remain relatively dry for much of the night as the precipitation encounters dry air per latest observed and forecast atmospheric soundings. A southeasterly flow and plenty of cloud cover will keep temperatures relatively mild overnight. Readings will also be relatively uniform across the region with most areas in the upper 30s to mid 40s. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... 12Z guidance remains in relatively good agreement bringing the weak surface system and upper level trough through the region on Wednesday. Rain and patchy fog will continue. Rainfall totals will reach a half inch to an inch in most areas with a few locations possibly topping out just over an inch. Cyclogenesis will occur as the system exits to the east and into the Gulf of Maine. This will allow winds to switch to the northwest, bringing drier air into the region as Canadian high pressure builds into Maine and New Hampshire. The rain will taper to scattered showers with any chance of precipitation shifting to northern and eastern areas. && .LONG TERM /THURSDAY THROUGH TUESDAY/... A drier airmass will be moving into the region as low pressure continue to slowly scoot off to the east on Thursday and Friday while broad high pressure becomes centered across Ontario/James Bay/Quebec. Other than some lingering upslope rain or snow showers across the mountains on Thursday, this will give us a couple of mostly dry days with well above normal temps again Thursday with highs around 50 degrees south of the mountains, but Friday will see highs back down to around 40 degrees. As we go from later in the day on Friday and through the weekend, the high pressure will slide east and strengthen over Quebec or the Maritimes, forcing the previously mentioned low pressure back to the south and west. Increasing northeasterly flow with a tightening gradient between these two features will send higher moisture back our way, with mostly cloudy conditions and increasing shower or snow shower chances, especially closer to the coast. However, Ptype along the coast is expected to be mostly rain. Wind gusts will also be highest along the immediate coast from Friday into the weekend, where 25 to 35 mph look possible, while inland areas could see gusts to around 25 mph. The forecast has gone more pessimistic on the cloud cover for Saturday and Sunday, and with more cloud cover expected, have also gone on the cooler side of guidance. For next week, the weather looks to remain somewhat unsettled with the GFS and ECWMF showing a disturbance heading in our general direction while a ridge builds across the center CONUS. The ECMWF has the same high pressure holding fairly strong over Quebec (and even building slightly farther south) which would send the wave more to our south while the GFS has the high weakening, which would allow the wave to move across our area and bring increasing precip chances. With such big discrepancies in the upper air pattern amongst the global models, don`t see any reason to deviate from the low-end PoPs from the NBM. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... Short Term...Mainly IFR and LIFR conditions tonight through Wednesday in low clouds and rain. Some brief periods of mixed precipitation possible in the far north. Patchy fog developing as well during the overnight hours. This precipitation will taper off Wednesday night as winds shift to the northwest and drier air enter the region. Long Term...VFR conditions are expected on Thursday/Friday with high pressure building in, except a few snow showers and MVFR ceilings could last into Thurs afternoon at HIE. From Friday evening into the weekend, increasing moisture and northeast winds will bring increasing chances for rain or snow showers as well as MVFR ceilings, especially along the coast. && .MARINE... Short Term...An area of low pressure slowly tracks towards the Gulf of Maine Wednesday with winds diminishing to light and variable...but seas increasing to around SCA thresholds. SCA seas persist into Wednesday night as low pressure departs east and winds pull around to the northwest. Long Term...SCA conditions look to continue through the upcoming weekend and into early next week with seas remaining elevated. North to northeast winds will also stay brisk across the waters being between an area of low pressure to the east and a strong high pressure to the north. Wind gusts will be around 30 kt from Thursday night through the weekend but could approach or even exceed Gale force at times during this period. Winds may diminish somewhat early next week. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 8 PM EST Wednesday for ANZ152-154. && $$ NEAR TERM...Ekster SHORT TERM...Cannon LONG TERM...Combs
National Weather Service Wilmington OH
914 PM EST Tue Dec 6 2022 .SYNOPSIS... Occasional showers can be expected at times through the work week as a series of low pressure systems move through the region. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... The 00Z KILN sounding captured a sharp inversion at about 850mb, with a very stable (and very moist) boundary layer underneath. Above the inversion, lapse rates are actually somewhat steep. As some marginal elevated instability has been able to develop, some embedded thunderstorms have formed within the wider area of precipitation. With the steep lapse rates and somewhat cool profile (freezing level at about 10kft, -20C at about 20kft) some small hail could form in the stronger cores. Although visibilities have improved slightly where rain has fallen, parts of the northern / northeastern ILN CWA remained in a more favorable environment for very thick/low stratus and fog development. There have been widespread 1/2SM observations, with a few 1/4SM readings on occasion. With very light surface flow, HRRR visibility projections suggest at least a risk of patchy dense fog continuing through the overnight, though it is unclear if the truly dense fog will become persistent/concentrated enough for an advisory. Previous discussion > A weak boundary remains stalled out southwest to northeast across our area this afternoon. A wave of low pressure will ride northeast along it tonight and ahead of the low, a 30 to 40 knot 850 mb jet will shift east across the upper Ohio Valley. This will lead to an increase in shower activity through this evening with categorical pops overspreading much of our area. Will hang on to a mention of thunder across our southeast as some elevated instabilities work up from the south overnight. Meanwhile, areas of fog are persisting across our area this afternoon and vsbys will likely begin to drop off again this evening into the overnight hours. Temperatures will remain fairly steady overnight, generally ranging from the mid to upper 40s in the northwest to the mid to upper 50s in the southeast. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... The boundary will shift slightly off to our southeast Wednesday morning as the surface low lifts off to the northeast. A few showers may linger early across our far southeast, but otherwise expect mainly dry conditions. Lingering areas of fog in the morning should also dissipate, but clouds will hang around through the day and likely into Wednesday night as a fair amount of moisture will remain in the lower levels. Temperatures will only rise a few degrees on Wednesday with afternoon readings ranging from near 50 degrees in the northwest to the upper 50s in the far southeast. Lows Wednesday night will be in the upper 30s to mid 40s. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Active weather pattern with temperatures generally above normal through the long term forecast period. Model solutions consistent and therefore forecast confidence is high for Thursday/Thursday night with a mid level shortwave and associated surface low tracking through the Ohio Valley. This will offer an enhanced chance for rain, with the best chance for pcpn focused across ILN/s southern counties. Main mid level shortwave to pass through the Great Lakes on Friday leading to a continued chance for rain. Mid level ridging to bring dry weather Friday night into Saturday. Model solution spread and therefore uncertainty increases later Saturday into Sunday with some solutions offering light QPF with ILN/s area in a weakly forced area between systems. Have limited any pops to slight chance mainly east during this time frame. Mid level flow amplifies with ridge building into the area Monday ahead of closed low moving into the plains. Have trended drier than the NBM with main pcpn holding off until Monday night/Tuesday as the ridge axis shifts east and moisture overspreads the area. Above normal temperatures forecast for Thursday and Friday. Temperatures closer to normal this weekend before warming above normal next week. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... Significantly reduced aviation conditions are expected through the next 12-18 hours. The region is covered in widespread LIFR ceilings, with a few IFR or even MVFR breaks. However, these breaks should fill in over the next couple hours, leaving prevailing LIFR ceilings through the overnight hours. Visibilities range from LIFR to MVFR, but are also expected to settle into the LIFR/IFR categories overnight. There is certainly a chance of some dense fog (1/4SM) and this may need to be included in the TAFs as the timing and location becomes more certain. In addition to the above, rain is also moving into the area. This rain is not likely to result in any further reductions to aviation conditions, which are already quite low, but there will be a chance of thunder (placed in a TEMPO group) for Cincinnati. Conditions are expected to very gradually improve tomorrow, with IFR ceilings lasting until early to mid afternoon, and IFR visibilities lasting until late morning. VFR conditions are expected very late in the TAF period or closer to 00Z. Winds will be light through the period with no significant impacts expected. OUTLOOK...Episodic periods of MVFR/IFR conditions possible through Saturday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...JGL NEAR TERM...Hatzos/JGL SHORT TERM...JGL LONG TERM...AR AVIATION...Hatzos
Area Forecast Discussion
National Weather Service Louisville KY
805 PM EST Tue Dec 6 2022 .Mesoscale Update... Issued at 802 PM EST Tue Nov 29 2022 Sfc low pressure is analyzed near Paducah this evening, with the warm front draped northeastward into central KY. Numerous showers and a handful of elevated storms have developed west of I-65, where a 30+ kt low-level jet has contributed to robust low-level moisture transport. Available instability is weak and largely elevated. The southern half of central KY will have the best chance at storms becoming marginally sfc-based tonight, but even BWG soundings show marginal low-level lapse rates. The 00z BNA sounding shows stronger instability, including around 500 J/kg SBCAPE with a mid 60s sfc dewpoint. Instability will likely remain weaker further north in south-central KY, but will need to keep an eye on any storms in that area with such strong low-level shear in place. A brief tornado is still not out of the question. Otherwise, small hail looks likely from any stronger storms that develop. Some areas south of the Cumberland Pkwy have already seen more than 1.50 inches of rainfall, so minor flooding issues could develop on Wednesday in southern KY. The area of showers ongoing now may tend to re-orient slightly more WSW to ENE over southern KY Wednesday morning. && .Short Term...(This evening through Wednesday) Issued at 330 PM EST Tue Dec 6 2022 Latest water vapor imagery and RAP analysis showed a steady stream of moisture from Arkansas back to west Texas along a southwest wind aloft that will continue to advect a good amount of moisture into the Ohio Valley over the next 24 to 30 hours. Surface obs showed surface relative humidity values between 80 and 90 percent with some lingering reduced visibility due to some light fog, drizzle or light rain in the region. Radar returns during the early afternoon were mainly confined to the KY parkways and south. Model forecasts continue to hint at a low level jet max over mainly Kentucky along and south of the Kentucky Parkway system, and along with a steady influx of water vapor based on satellite imagery, areawide rain is a certainty at this point tonight. Precipitable water amounts are at or above 90th percentile for climatology, also indicative of a good supportive atmosphere for overcast conditions and rain. Model soundings in the southwest corner of the forecast area (west of I-65, South of western KY parkway) show decent lapse rates with good bulk shear and effective inflow values, which could be indicative of some severe weather chances this evening. While probabilities will be low, there could be a chance for a brief tornado or damaging wind gusts from a strong developing thunderstorm. Rain tapers off to the KY parkways and southward for light precipitation through Wednesday. Through Wednesday, anywhere from 0.25" to 0.50" of rain along and south of the KY Parkways is possible, which falls roughly between the 25th and 50th NBM percentiles. 10th percentile probabilities have rain areawide between roughly 0.05" to 0.30" of rain, where 90th percentile rain amounts are anywhere from 0.50" to 1.30" (reasonable highest case scenario). .Long Term...(Wednesday night through Tuesday) Issued at 320 PM EST Tue Dec 6 2022 Highlights: - Wet and mild weather through the end of the week with best rain chances Thursday into Friday morning - Rainfall amounts range from 0.50" to 1.00" across central KY with less than an inch in southern IN through Friday morning - Slight break from the rain over the weekend - More rain chances early next week Our stagnant mild weather pattern will continue through the end of the week as the upper flow becomes more zonal across the Ohio Valley with a quasi-stationary sfc boundary remaining draped across southern KY and northern TN. Embedded upper shortwave trough will eject out of the Four Corners Thursday into Friday. At the surface, a weak system will work eastward out of the central Plains into the Ohio Valley by Friday morning. Ahead of this system a strong LLJ will work into KY during the day Thursday as the aforementioned sfc boundary lifts slightly northward into central KY. Rain will increase over the area from the west-southwest during the day thanks to the added lift from the sfc boundary and LLJ. Model soundings show very little in the way of instability but with the lift and model soundings showing some 0-3km shear, not going to rule out the possibility thunder Thursday night early Friday morning. Rainfall totals look to be around 0.50" to 0.75" with some localized areas approaching 1.00". Temperatures will remain mild with highs in the mid/upper 50s with the exception of south-central KY towards the TN border behind the sfc boundary where afternoon temperatures could climb into the low/mid 60s. Sfc low and associated cold front will sweep through the Ohio Valley during the day Friday as slight ridging builds in over the Ohio Valley behind the departing shortwave trough. Rain chances will decrease from the west to the east but wrap around moisture behind the departing system could keep some clouds lingering across north- central KY and southern IN during the day. Temperatures will warm to the low/mid 60s on the day which is 10-15 degrees warmer than climo norms. Bulk of the weekend continues to look mainly dry but with another quasi-zonal flow setting up over the Ohio Valley. Another embedded shortwave looks to work through the region Saturday into Sunday. This could bring a slight chance of PoPs, mainly across the southern portion of our CWA through the weekend. For now, going to stay with the NBM which keeps slight chance PoPs from the parkways southward through the weekend. Highs will be closer seasonal levels with highs in the upper 40s/low 50s and lows in the upper 30s/low 40s. Deterministic models are starting to show the development of an amplified weather pattern across the CONUS for the middle of next week. With a deepening trough across the western US and ridging building across the Plains and Midwest. Both the Euro and GFS develop the western trough into a closed low over the central plains and Upper Midwest Tuesday into Wednesday with a sfc low and a strong associated cold front at the sfc. Concern in this kind of pattern and setup would be the potential for strong to severe storms somewhere across the Plains and Midwest by the middle of the week. && .Aviation...(00Z TAF Issuance) Issued at 650 PM EST Tue Dec 6 2022 Confidence is high on IFR and LIFR ceilings lingering overnight and into Wednesday morning. Periods of SHRA are forecast tonight into early Wednesday as low pressure lifts northeast near the Ohio River. VCTS is certainly possible, though confidence is only medium in exact timing of TSRA. The bulk of the showers should push south of the northern terminals (HNB/SDF/LEX) during the early morning hours of Wednesday, while it will take longer for BWG to dry out. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Mesoscale...EBW Short Term...MCK Long Term...BTN Aviation...EBW
Area Forecast Discussion
National Weather Service Midland/Odessa TX
523 PM CST Tue Dec 6 2022 ...New AVIATION... .SHORT TERM... (This afternoon through Wednesday night) Issued at 150 PM CST Tue Dec 6 2022 Per latest water vapor imagery and RAP 500mb analysis, southwest flow has commenced over the region, evidenced by increasing clouds region-wide today. A few transient showers have been observed across portions of the Trans Pecos and Permian Basin, though most locations will stay dry, at least until later this afternoon into this evening. A positively-tilted trough remains entrenched between a broad trough along the US/Canada border and a broad ridge over the southeastern CONUS, and as this trough translates eastward, its attendant jet as well as a series of shortwaves embedded in the southwesterly flow aloft will yield increasing rain chances across much of the region through Wednesday night. As ascent increases this afternoon, precipitation will begin to overspread the area from southwest to northeast, expanding in coverage overnight through Wednesday. Despite somewhat limited instability and marginal lapse rates, thunderstorms will be possible, though are not expected to be severe. The best chance for thunderstorms will be Wednesday afternoon into Wednesday evening, and storms could produce localized enhancements to rainfall received. Overall, however, rainfall amounts will generally remain on the light side, under 0.50" for the duration of the event. Rainfall will diminish rather quickly overnight Wednesday night as the jet progresses northeast of the region, and the aforementioned trough moves across the Rockies, sending an attendant Pacific front eastward through the area. Temperatures, despite the expected rainfall, will remain on the mild side. As a matter of fact, Midland set a record warm low both Monday morning and this morning and another record warm low is expected Wednesday morning. The current forecast low tonight is 58 degrees, which would easily beat the standing record of 51 degrees, set on December 7, 1980. Highs Wednesday afternoon will be several degrees cooler than today, though will remain well above normal, in the middle 60s to lower 70s for most. Wednesday night, as the Pacific front sweeps across the area, portions of Southeast New Mexico south to the Davis Mountains will see temperatures fall into the 40s, though lows in the 50s to around 60 degrees are expected elsewhere. && .LONG TERM... (Thursday through Monday) Issued at 150 PM CST Tue Dec 6 2022 West Texas and Southeast New Mexico remains nestled between a broad ridge over the Gulf of Mexico and a trough over the Pacific Northwest. The ridge keeps temperatures into the 60s and 70s for the end of the week before it flattens out over the weekend and temperatures fall back towards average. A weak disturbance looks to skirt just north of the area and will bring the chance for some showers to the northeast Permian Basin Saturday afternoon. Indications are that rain amounts stay low, but given drought conditions, any rain is a welcomed sight. The beginning of the next week features a longer wave trough moving out of the Pacific Northwest and rolling across the northern Plains. For now, it does not appear to be a threat precipitation wise, but the forecast area could see fairly breezy conditions as the southern edge of this system moves overhead. With the trough nearby during the Monday to Wednesday timeframe next week, temperatures will dip back towards near or below average. && .AVIATION... (00Z TAFS) Issued at 515 PM CST Tue Dec 6 2022 Winds are generally light and southerly with a broken cloud deck around 10k feet. Showers are developing and impacting FST. These will slowly spread north and east this evening and overnight. Ceilings should gradually fall as these showers spread. Many terminals will fall to MVFR early tomorrow morning with lowered ceilings and reduced visibility in heavier showers. && .PRELIMINARY POINT TEMPS/POPS... Big Spring 59 71 58 72 / 50 40 50 0 Carlsbad 53 66 47 66 / 30 40 30 0 Dryden 59 71 59 74 / 20 0 0 0 Fort Stockton 57 76 54 71 / 50 10 20 0 Guadalupe Pass 51 59 44 59 / 30 50 30 0 Hobbs 53 64 49 65 / 40 50 50 0 Marfa 46 71 41 68 / 50 10 10 0 Midland Intl Airport 58 72 56 71 / 50 30 40 0 Odessa 58 71 56 70 / 50 30 40 0 Wink 55 70 50 70 / 40 30 40 0 && .MAF WATCHES/WARNINGS/ADVISORIES... TX...None. NM...None. && $$ SHORT TERM...84 LONG TERM....93 AVIATION...91
Area Forecast Discussion...UPDATED
National Weather Service Memphis TN
600 PM CST Tue Dec 6 2022 ...New AVIATION... .DISCUSSION... (This evening through next Monday) Issued at 334 PM CST Tue Dec 6 2022 We`re currently in a bit of a precipitation lull, but widespread showers, and a few thunderstorms, will affect the Mid-South late tonight through Thursday. Locally heavy rainfall will be the primary concern though there is a potential for a few strong storms. Expect above normal temperatures through the remainder of the work week. A classic split-flow pattern continues over the CONUS this afternoon with a closed shortwave trough moving slowly southeast along the CA coast. Strong southwest flow aloft downstream of this trough has tapped into a subtropical air mass, advecting deep moisture across the Southern Plains and into the Lower MS Valley. Precipitable water (PWAT) is slightly lower than 24 hours ago in the wake of yesterday`s trough but we`ll see additional moistening through tonight as PWATs climb to near 1.75". As stated yesterday, these PWATs are is in the 99th percentile of climatology for early December, indicating highly anomalous moisture throughout the column. A warm front continues to lift poleward slowly this afternoon and is located near the northern reaches of the CWA along the MO and KY state lines. Just north of this front, dense fog resulted in visibility below 1/2 mile through mid-afternoon but these conditions have largely improved. Another area of large-scale ascent can be inferred from the water vapor loop and this will overspread the area this evening and and overnight. The aforementioned warm front is expected to stall and eventually slide back to the south late tonight. Warm advection over the top of this boundary will enhance frontogenesis from 850 mb up through 500 mb, enhancing the thermally direct circulation and providing ascent in the vicinity of the boundary. CAPE will be somewhat limited, but shear is sufficient to warrant a marginal risk for severe thunderstorms, mainly north of I-40. Effective bulk shear near 40 kts is supportive of organized convection and there is enough curvature in the hodograph to at least note the possibility of a few supercells. Low-level shear is supportive of minimal tornado mention. This conditional severe weather threat is low confidence, but will be watched closely throughout the evening. QPF progs continue to indicate widespread rainfall in the 1-2" range with localized higher amounts through Thursday night. The greatest totals will occur in areas where banded precipitation is favored and/or precipitation echoes train but that will depend on exactly where the front sets up. This front will remain in the vicinity throughout Thursday and into Thursday night, maintaining high PoPs, especially along and north of the front with temperatures remaining well above normal. Areas in the far southeast portion of the CWA will see much lighter precipitation through this time frame. The cold front will swing through the area early Friday as an occluding trough lifts northeast across the Midwest. A few thunderstorms will be possible ahead of the front, but nothing significant is anticipated at this time. Cooler and drier air will move into the area behind this front with with PWATs briefly dropping below 0.50" by Friday afternoon. This will result in temperatures returning to near climatology Saturday with highs mainly in the 50s and lows in the 40s. This respite from the rain looks to be short-lived as moisture quickly returns and rain chances re-enter the forecast for Saturday. Much of the ensemble uncertainty by late weekend exists in the evolution of the trough off the West Coast. A majority of the NAEFS and EPS members favor a weaker trough with more quasi- zonal flow aloft over the southern tier of the CONUS to begin the week. However, a few do feature a deeper, slower trough. This particular system will bear watching as it moves onshore and approaches the Mid-South toward midweek as it could offer another potential for significant weather impacts. In the meantime, the period from late weekend into early next week looks to be highlighted by continued rain chances with temperatures climbing back above normal. MJ && .AVIATION... (00Z TAFS) Issued at 539 PM CST Tue Dec 6 2022 00Z surface analysis showed a cold front extending from ARG-SIK- PAH line. IFR/LIFR prevailed the north of the front, with VFR/occasional MVFR to the south. The cold front will drop south through the night, stalling over the far southern MEM TRACON by 15Z. In the interim, a weak passing disturbance will support isolated TSRA along the front, perhaps within the 25SM norheast of MEM. 00Z TAF followed HRRR guidance frontal timing, showing passage through MEM during the early outbound push. With the front stalling between MEM and TUP, expect little flight category improvement Wednesday, as occasional showers reinforce the most frontal inversion. In the warm sector, TUP should prevail at MVFR with VFR potential limited by SHRA. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...MJ AVIATION...PWB
Area Forecast Discussion
National Weather Service Shreveport LA
1002 PM CST Tue Dec 6 2022 ...New UPDATE... .UPDATE... Issued at 934 PM CST Tue Dec 6 2022 Updates this evening remain minor as only a few adjustments were made to the present forecast. Decided to adjust overnight lows by 1-2 degrees across NW zones based on present sfc analysis and the latest 00z guidance. Sfc theta-e in both the NAM and HRRR show a very slow SE progression of the cold front that is currently located to the NW of the Idabel,OK obs site as of 9:30 PM CST. Sfc analysis this evening also showcased some fog developing just south of the boundary in De Queen. Based on this and the idea that other sites may see a similar theme under a rather moist environment ahead of the boundary, brief patchy fog has been added through midnight for sites north of I-30. Given increased coverage of shower activity overnight, and into the early morning, the idea of fog past midnight remains low at this time. The final adjustment was to remove low end odds of thunder along the I-20 corridor to fit in line with the SPC general thunderstorm outlook. Rain coverage will continue to develop across northern zones, mainly I-20 and north over the next couple of hours, heading into Wednesday morning. Based on the confidence and placement of this, POPs have not been adjusted during this update. /53/ && .SHORT TERM... (This evening through Wednesday Night) Issued at 239 PM CST Tue Dec 6 2022 A frontal boundary across eastern Oklahoma into Arkansas will be the main driver of the weather pattern through the short-term period. The front is forecast to remain in place through Wednesday before gradually lifting north on Wednesday night. Low-level instability associated with the front combined with moist west to southwest flow aloft will maintain mostly cloudy skies through the period across the entire ArkLaTex. Rain chances will gradually increase tonight through Wednesday along the frontal boundary as instability increases in response to an upper-trough kicking out of the Rockies and moving east into the Great Plains. However, forcing across the ArkLaTex will be relatively weak, allowing for mainly widespread showers tonight, mainly in the vicinity of the front across Arkansas and Oklahoma, with the addition of isolated thunderstorms on Wednesday into Wednesday night. Otherwise, expect warm temperatures across the region with highs on Wednesday approaching 80 degrees across much of east Texas and north Louisiana with slightly cooler temperatures across the I-30 corridor where rain chances will be higher. Overnight lows both tonight and Wednesday night will be in the 60s. /05/ && .LONG TERM... (Wednesday Night through Tuesday) Issued at 239 PM CST Tue Dec 6 2022 The recent long term forecast story, featuring waves of moisture riding on southwesterly flow on the northwest side of a stubborn ridge over the Gulf, will change little this week. Said area of ridging established over the Gulf of Mexico by mid week will remain firmly in place through the end of the workweek and into the weekend. Late in the weekend, this long lived pattern will start to come to an end, as the upper level high breaks down and the ridge broadens and begins to drift east, making way for the next large scale feature of note. A pronounced trough will dig south from Canada, deep into the Rockies before ejecting east over the Great Plains early next week, characterized by a tight gradient of 500mb heights on its leading edge, extending from the Great Lakes south and west into west Texas and northern Mexico. This trough looks to bring with it a potent cold front, which when introduced to the warmer, very moist environment across the southeast, may set the stage for another round of unsettled weather. It remains far too early to deal in speculation of precise specifics, but it bears mentioning that the latest SPC severe weather outlook highlights the ArkLaTex in a slight risk (15%) for Day 7 (Monday, December 12th). There is still plenty of time for this forecast to drift in both time and space, but based on previous performance of Day 7 SWOs highlighting the ArkLaTex this season, this feature will be closely monitored in the coming days. Rainfall will progress south and east into the ArkLaTex Thursday, lingering overnight before clearing the region Friday afternoon. The next wave will be hot on its heels, with rain chances returning to our northern and western zones shortly after sunset, overtaking the region and remaining areawide through Tuesday, not departing entirely until overnight into Wednesday. Above average temperatures late this week (mid to upper 70s) will begin to fall over the weekend (upper 50s to lower 70s) before rebounding slightly early next week in advance of the frontally- driven cool down. Lows will drift accordingly, from 50s to 60s late this week, followed by a round of 40s to 50s, and a return of 30s mid next week. /26/ && .AVIATION... (00Z TAFS) Issued at 536 PM CST Tue Dec 6 2022 Mainly OVC skies will prevail across all terminals through the 00z TAF cycle as a warm front continues to advance north of the airspace. As a boundary sets into place, this will help to generate -RA, increasing in coverage by 07/11z, with possibly even -SHRA across extreme northern terminals by 07/15z. The general theme is for VFR conditions to prevail through the early stages of the period ahead of MVFR with lowering CIGs. Some brief IFR conditions may be possible across terminals by mid to late morning. Continue to expect south to southwest winds to average between 5 to 10 knots through the period, with an occasional gust not out of the question. /53/ && .PRELIMINARY POINT TEMPS/POPS... SHV 67 80 65 77 / 30 20 10 10 MLU 66 80 64 79 / 20 20 10 10 DEQ 59 70 60 73 / 70 90 70 60 TXK 64 76 64 76 / 70 70 40 40 ELD 63 76 61 75 / 60 60 30 20 TYR 66 78 66 77 / 40 20 10 30 GGG 67 79 65 77 / 30 20 10 20 LFK 66 81 65 79 / 10 10 0 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ SHORT TERM...05 LONG TERM....26 AVIATION...53
Area Forecast Discussion
National Weather Service Las Vegas NV
647 PM PST Tue Dec 6 2022 .SYNOPSIS...Wintry weather moves into our northwestern areas this evening, sliding east through Lincoln County tomorrow afternoon. For the rest of the area, seasonal temperatures and dry conditions persist before a more potent system approaches over the weekend. && .UPDATE...Continuing to track the incoming upper level low as it pivots into to region tonight. Satellite imagery through the early evening would have the center of the the low finally moving ashore along the central California coast. An obvious area of decent forcing and upward motion was present out ahead of the main system based on 500mb analysis as strong potential vorticity wrapped itself around the low. Even away from the low itself there was at least some forcing evident as clouds increased and cooled over Inyo, Esmeralda, and central Nye County. While observations are few and far between in that area and radar returns have been limited, based on the satellite trends in the past hour and surface temperatures being below freezing, it likely has just started snowing under these better organized cloud signatures. Elsewhere, it remains dry under partly to mostly cloud skies. The forecast for overnight remains about the same with the only changes being made to precipitation chances based on the latest hi- res short term models. The main uncertainty overnight will be how far south and east precipitation will be able to blossom. Each run of the HRRR keeps areas like Lincoln County dry through the night which would match up with the slower progression of the system moving east. If the system gets any slower, there will be concerns for cold core showers in eastern Nye and Lincoln County Wednesday afternoon. Based on the latest forecast and trends, there is no need to make any changes to the Winter Weather Advisory. -Nickerson- && .PREVIOUS DISCUSSION...112 PM PST Tue Dec 6 2022 .SHORT TERM...Today and Wednesday. The low that has been lingering along the West Coast finally swings through tonight and tomorrow. As it does so, positive differential vorticity advection and diffluence aloft will produce ascent over the northern half of the CWA. Precipitation s expected to begin around 5PM in Esmeralda, northern Inyo, and central Nye Counties. Ascent and the cold core of the low will produce relatively-steep lapse rates, possibly enough to yield some low-end CAPE (100 J/kg or less). With this in mind, can`t rule out convective enhancement of precipitation, and possibly a few flashes of lightning. Outside of the Owens Valley, snow levels will be around 5000-5500 feet at precip onset, but fall to 4000-4500 feet overnight. In the Owens Valley, snow levels may support a brief window of rain initially, but precip will be primarily snow. Accumulations in Inyo County come to an end early tomorrow morning, lingering until lunchtime in Esmeralda and Nye Counties. Amounts? Well, it`s a little tricky. Highest totals will be in the higher terrain (above 5000 feet), where 3-5 inches are possible. Places of most concern are along US- 95 near Goldfield and Highway-266 near Lida Summit. Confidence in impactful accumulations is less in northern Inyo County, though if any occur, Highway-168 through Westgard Pass will likely see them. Below 5000 feet, anything from just rain to 2" of snow is generally expected. The caveat in this forecast extends from the potential for convection and precipitation banding, which could produce locally-higher amounts and periods of low visibility. With all this in mind, opted to issue a Winter Weather Advisory for Esmeralda and central Nye Counties for tonight and tomorrow morning. Farther east in Lincoln County, snow amounts have trended downward slightly. Current forecast has 2" or less for the US-93 corridor between Alamo and the White Pine border. South of Alamo, precip will be mostly rain except on the high terrain. Thus, opted to leave Lincoln County out of the advisory, but minor impacts will be possible. Snowfall should begin after midnight, and come to an end tomorrow afternoon. Light snowfall is also expected in the Spring and Sheep ranges, as well as the high terrain of northern Mohave County, but impacts are not anticipated. For the rest of the area, dry conditions and seasonal temperatures prevail. Highs are forecast to be in the 50s and low 60s as clouds hang around. .LONG TERM...Thursday through Monday. As the aforementioned system exits our area, a series of weaker shortwaves move through. These won`t do much other than keep temperatures slightly below normal and bring periods of cloud cover. A more robust system takes aim at the region over the weekend. Southwest breezes begin to increase on Saturday, becoming gusty on Sunday. The ECMWF EFI is already beginning to highlight Sunday for the potential of strong winds. The bigger question with this system is the precip potential for the Mojave Desert, which hinges on the depth of the trough. Ensemble guidance shows some variability in timing and depth, so uncertainty remains in this regard. However, with a modest atmospheric river forecast, confidence is fairly high in accumulating snow for the southern Sierra during this time. As the weekend draws closer, details will become more clear, so stay tuned! && .AVIATION...For Harry Reid...Light and mainly diurnally driven winds through Thursday morning. A more persistent southwest wind at 10-15 kts will develop Thursday afternoon but weaken to a more diurnal flow in the evening. A few clouds are possible around 8k feet but otherwise any CIGs should be AOA 15k feet. For the rest of southern Nevada, northwest Arizona and southeast California...Isolated areas of SCT-BKN040-060 today otherwise SCT-BKN AOA 15k feet. Precipitation will move into Inyo, Esmeralda and Nye during the evening hours with CIGs lower to BKN020-050 with isolated lower CIGs and mountain obscurations. The majority of precip will fall as snow and limit VSBYs to under a mile at times. Elsewhere, mainly light diurnally driven winds through Wednesday morning then southwest winds of 10-20 kts mainly at locations south of I-15. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ DISCUSSION...Woods AVIATION...Czyzyk For more forecast information...see us on our webpage: or follow us on Facebook and Twitter