Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/07/24


Area Forecast Discussion
National Weather Service Grand Junction CO
441 PM MST Wed Nov 6 2024 .KEY MESSAGES... - Scattered snow showers continue through Thursday with the San Juan mountains receiving 4 to 8" of additional snowfall. - Gusty winds up to 35 mph will continue this afternoon across the western half of the forecast area. - Light snow may continue in the central and southern mountains through the end of the week. Temperatures will also remain below normal through Friday. && .SHORT TERM /THROUGH THURSDAY NIGHT/... Issued at 332 PM MST Wed Nov 6 2024 Satellite imagery this morning indicated this low was situated near the Four Corners and has slowly drifted into southwest Colorado this afternoon. This has allowed snowfall to continue today across southern and central mountains and adjacent valleys. Total snow accumulations seem to be right around where we were expecting with 4 to 10 inches across the central and southern mountain areas with less over the northern mountains since this storm started yesterday (Tuesday) morning. The valleys were a tricky forecast in terms of snowfall as the low was expected to be more progressive but stalled as closed lows tend to do some times, especially since this one is cut off from the main flow. Some valley locations received 1 to 4 inches in spots. A strong jet is rounding this closed low with windy conditions across the northern and western sides of the low across northwest Colorado into eastern Utah with gusts in the 20s and 30s. This jet will be a key player in how this closed low tracks and the forcing from this jet on the northern and western sides looks to help force this closed low southwestward into Arizona by Thursday. We will see if this does in fact happen though as the low isn`t really moving much right now. The best forcing and dynamics are seen across eastern New Mexico into southeast Colorado along the southern and eastern edges of this closed low. This is also where the heaviest snow accumulations are expected Thursday and Friday. We will be on the western fringes of this dynamic forcing and better moisture with easterly to northeasterly flow around the northern sides of the low. The San Juan mountains look to continue to receive additional snowfall in the realm of another 4 to 8 inches with locally higher amounts through Thursday, so decided to extend the Winter Weather Advisory for the San Juan mountains through 5 pm Thursday to account for this as impacts are still likely to occur at the higher passes. Currently roads remain wet at lower elevations with snowpacked roads at the highest passes but expect conditions to deteriorate overnight into Thursday as temperatures are cold and will get a bit colder. Mountains are obscured but showers remain scattered at this time. The southwest Colorado valleys received continuous snow this morning into the afternoon and is becoming more scattered at this time. Roads along Highway 160 remain wet but could become slick in spots especially overnight as highs struggled to make it out of the upper 20s and are near 30 this afternoon, but this is colder than the forecast, which can affect snowfall totals. After blending in the latest hi-res data, seems like the southern valleys could see an additional 2 to 4 inches of snow tonight as the HRRR is indicating a few bands moving through overnight. However, these amounts still remain below our advisory thresholds so will hold off on issuing highlights for the southern valleys. This is an area to keep a close eye on tonight though as they remain in closer proximity to the low with this low expected to shift southwestward Thursday. Snowfall rates drop off significantly to light showers and less accumulations are anticipated by Thursday evening and Friday as northeast New Mexico and southeast Colorado begin to take the brunt of the dynamics associated with the low and moisture/snowfall with it. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Issued at 332 PM MST Wed Nov 6 2024 By Friday, the low will be centered over New Mexico and tracking northeastward into the Colorado Plains. As the low lifts northeast, easterly flow will push rich wrap-around moisture will back toward the Divide, potentially keeping mountain snow showers in the forecast through the day. These showers will be generally light, with minimal accumulations on the western side of the Divide. Easterly flow promotes downsloping over the western side of the Divide, leading to warming and drying air, and minimizing accumulation potential. These light mountain showers will linger into Saturday before finally tapering off as the low moves into the Northern Plains. Ridging begins to build in late Saturday, with clearing skies and gradually moderating temperatures expected through Monday. Temperatures do remain below normal through the period, however, with the moderation allow temperatures to warm from 10-15 degrees below normal to more like 5-10 degrees below normal. The next Pacific storm begins to impact the Pacific Northwest on Monday afternoon, and is expected to drop into the Great Basin some time on Tuesday. Models are still in somewhat poor agreement over the evolution of this system, so stay tuned. As it stands, this unsettled and cooler pattern will persist well into next week. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 433 PM MST Wed Nov 6 2024 Snow showers continue through the TAF period across southern mountains to the Four Corners, mainly affecting KDRO, KCEZ and KTEX with IFR/LIFR conditions at times due to lower CIGS and VSBY. KGUC, KMTJ and KASE will have ceilings near or below ILS breakpoints overnight with isolated vicinity showers. Gusty northeast winds will occur across TAF sites in eastern Utah and northwest Colorado with gusts 20-30 kts possible through about 06Z. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...Winter Weather Advisory until 5 PM MST Thursday for COZ018-019. UT...None. && $$ SHORT TERM...MDA LONG TERM...BGB AVIATION...DB
Area Forecast Discussion
National Weather Service Goodland KS
501 PM MST Wed Nov 6 2024 .KEY MESSAGES... - Periods of accumulating snow will create dangerous driving conditions in eastern Colorado and adjacent Kansas and Nebraska border counties tonight and Thursday. This includes the I-70 corridor from Flagler CO to Goodland KS. - Rain and snow chances will increase Friday into Saturday as another system moves out of the southern Rockies. Accumulating snow is possible in eastern Colorado and adjacent Kansas border counties. && .SHORT TERM /THROUGH THURSDAY NIGHT/... Issued at 300 PM MST Wed Nov 6 2024 The Winter Storm Warning was expanded in area this morning to include Sherman County, KS.. where precipitation-related cooling (i.e. melting) drove temperatures close to the freezing mark (temperature has been steady ~33F since 10 am MST at NWS Goodland). The Winter Storm Warning has also been extended in time (now in effect until sunset Thursday evening). Expect little change in the location of the rain/snow transition line on Thursday. Guidance indicates a `resurgence` in precipitation (from the south) during the day.. and additional snow accumulation (potentially significant) is likely over eastern CO. A Winter Weather Advisory remains in effect for Dundy and Cheyenne (KS) counties through sunrise Thursday morning. Current and recent runs of the GFS, HRRR, RAP and NAM NEST continue to indicate a potential for additional snow accumulation (2-4") over portions of the advisory area this evening and tonight.. mainly west of Highway 27 will be most affected. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Issued at 103 PM MST Wed Nov 6 2024 The main focus for the extended period will be on Friday and Saturday as a cutoff 500/700mb low moves north out of the southern New Mexico area and through the central Plains. Based on the latest runs of the GFS, NAM and ECMWF, there are differences in the track of the 500/700mb systems versus the surface. The GFS and ECMWF are more vertically stacked from the surface to 500mb w/ a track further east of the Front Range. The NAM however carries the 500/700 system north more along the Front Range before lifting into the north- central Plains almost north of the CWA, while the surface feature moves through the area as an inverted trough. These differences will result in the potential for quite varying amounts of QPF over the 36-48 hr period. The GFS/ECMWF solution being vertical stacked will be most favorable for ample persistent low level moisture to bring a decent round of mainly rain to the area(based on forecasted highs/lows). Colorado will see some colder air wrap into the area Friday night into Saturday morning on the back side of the system for snow showers to occur. There could be enough QPF available to produce a couple inches of snow from Flagler south. The overall potential QPF with this will range widely from 0.69" west into the 1.70-1.80" range east. These numbers are creating a Marginal/Slight risk for excessive rainfall for areas along/east of Highway 25 on Fri-Fri night. Pops will range from 70- 90% during the 24 hour period. There will be a wide range from 20% south to 70% north as the system lifts out of the area. For the NAM solution, the split track of the upper/lower systems is going to allow for mid level dry air to work in from the southwest behind the 500/700mb low. This will put the QPF emphasis on the inverted trough/low that swings through the region. While high PW(precipitable water) values will be present here and the GFS/ECMWF solution above, the NAM will see a similar wide range from west to east, but slightly lower amounts west due to dry air intrusion. For now until better consistency shows, will be following the latest GFS/ECMWF combo which mirrors the ongoing NBM guidance. Stay tuned here as any change in the track will impact potential precip totals area-wide. Going into Sunday, guidance has an upper ridge sliding across the central Plains carrying through Monday. A couple weak shortwaves do work east along the northern periphery of the ridge, but with dry conditions at the surface, not expecting any impacts. A stronger shortwave has the potential to work off the central Rockies late Tuesday into Wednesday. Nothing set to impact the CWA as it passes along with its mirrored surface trough, but there is a 20% chance for light rain/snow showers in Colorado on the backside of the system as the flow becomes more easterly and upslope/orographic. For temps, highs for Friday and Saturday will range in the mid 30s to mid 40s along/west of Highway 27. East of there, mid 40s to the lower 50s. Warmest of the two days will be Saturday. For Sunday through next Tuesday, low 50s west into the low 60s east. Cooling down slightly on Wednesday with upper 40s to upper 50s expected. Overnight lows will generally range from the upper 20s west in Colorado, into the mid and upper 30s east, especially east of Highway 83. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 453 PM MST Wed Nov 6 2024 At KGLD...light snow and low ceilings will continue to impact flight categories through the entire TAF period. The main upper low will move over the area tomorrow which will continue to provide lift for mainly snow, though there may be occasional changeovers to rain, particularly Thursday afternoon as temperatures warm into the mid to upper 30s. At KMCK...precipitation chances more uncertain at McCook. In fact, there may be a break in the precipitation tonight based on radar trends. Ceilings will be very close to the VFR/MVFR threshold and expect some minor lowering tonight will result in a return to MVFR which will persist into tomorrow. The next round of precipitation coming up from the south tomorrow will mostly impact areas further west, but still might see some showery type activity through the afternoon, mainly as rain. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...Winter Storm Warning until 5 PM MST Thursday for KSZ013. Winter Weather Advisory until 6 AM CST Thursday for KSZ001. CO...Winter Storm Warning until 5 PM MST Thursday for COZ090>092. NE...Winter Weather Advisory until 5 AM MST Thursday for NEZ079. && $$ SHORT TERM...Vincent LONG TERM...JN AVIATION...024
Area Forecast Discussion
National Weather Service Grand Rapids MI
630 PM EST Wed Nov 6 2024 .KEY MESSAGES... - Low clouds could stick around into Thursday - Wet Saturday night and Sunday, unsettled into Monday && .DISCUSSION... Issued at 330 PM EST Wed Nov 6 2024 - Low clouds could stick around into Thursday The main fcst challenge in the short term period is with low cloud trends. We`re in that time of year now when getting rid of low clouds in Michigan is not easy regardless of what guidance may say. Bufkit overviews from the NAM/RAP keep low level moisture trapped over much of the area on Thursday while various sky/cloud model forecasts show us sunny. Given that we have moist boundary layer conditions from the recent 1-2" of rain and there`s still considerable low clouds under the sfc high to our west will trend the sky forecast to be a bit more pessimistic. Per 925 mb RH progs, western and northern sections look more favored to keep the clouds Thursday while southeast sections have the better chance of sunshine. Min temps tonight could be a bit warmer than fcst and high temps Thursday a bit cooler should the clouds hang in tough. In the meantime we have a sfc trough dropping south through the area which is touching off areas of drizzle that are expected to persist into at least the early evening hours. - Wet Saturday night and Sunday, unsettled into Monday No major changes of note to the inherited forecast. Saturday night and Sunday still look quite wet as an opening upper cutoff low originating from the SW CONUS ejects towards the western Great Lakes. Model forecast consistency with this feature has been impressive, especially when you consider that patterns like these typically are characterized by marginal predictability at best. As noted previously, rain could be tenacious on Sunday. NBM guidance shows a PoP maximum anchored along the southeast Lake Michigan shoreline during this time. This is a good indicator of a lake- induced Convective Boundary Layer (CBL) that deepens eastward (downstream) towards the lee side of Lake Michigan. Bufkit soundings support the presence of this CBL along with Lake SBCAPE on the order of a few hundred J/kg. Current indications are that the convective depth under the inversion initially would be too warm to support thunder. However, from late Sunday into Sunday night, the upper PV max associated with the cutoff low will be crossing the region. A growing lake-induced CBL depth ahead of this feature, combined with cold air advection and synoptic ascent aloft, should assist in convective destabilization to the point where thunder look much more plausible. Lake effect clouds look to continue Monday with residual, albeit lesser, rain chances by the lakeshore. We might be looking at a brief period of dry conditions Tuesday, but by this point predictability in general will have basically fallen off the shelf. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 630 PM EST Wed Nov 6 2024 Ceilings will be primarily in the range of 1500-2500 AGL this evening as stratus clouds with areas of drizzle move through. Conditions will slowly improve late tonight and Thursday morning as the lower clouds move off to the southeast. WInds will be west to northwest AOB 10 knots. && .MARINE... Issued at 330 PM EST Wed Nov 6 2024 The Small Craft Advisory was extended earlier through 10 PM to account for a period of stronger north winds which follows behind a sfc trough sliding south down the lake. Those winds have been occurring at Ludington and the buoy there has 4 ft waves. The core of strongest winds on the HRRR (20kts) is shown to be near Grand Haven at 4 PM and near South Haven at 8 PM. After a lull in winds and waves later tonight into Thursday, we see another uptick in westerly winds for Thursday night into Friday as a low pressure area tracks across Hudson Bay. A Small Craft Advisory may be needed for this time frame, especially north of Holland. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory until 10 PM EST this evening for LMZ844>849. && $$ DISCUSSION...Meade/TJT AVIATION...Ostuno MARINE...Meade
Area Forecast Discussion
National Weather Service Indianapolis IN
915 PM EST Wed Nov 6 2024 .KEY MESSAGES... - Patchy fog expected tonight, mainly over SE and N portions of Central Indiana - Above normal temperatures to continue through the forecast period - Rain and a few thunderstorms late Saturday into Sunday, with additional rain chances mid week next week && .FORECAST UPDATE... Issued at 915 PM EST Wed Nov 6 2024 - Cloudy and Cooler Overnight Surface analysis this evening shows a departed cold front stretching across Ohio to Central KY and western TN. Strong high pressure was found over the northern plains. Winds across Central Indiana were from the northwest around 10 mph. GOES16 show cold air advection cloud cover development the past few hours, resulting in low, stratocu cloud cover. Dew points were in the upper 40s to lower 50s. Forecast soundings and time heights across the area show lower level moisture expected to be present through the night. HRRR also suggests high RH values overnight at 925mb. Given our Cold air advection and pressure gradient in place, this stratus development will be expected to persist as opposed to fog. Given the expected clouds, expect lows in the middle and upper 40s. && .SHORT TERM (This evening through Thursday)... Issued at 256 PM EST Wed Nov 6 2024 Much quieter weather has settled in over central Indiana this afternoon, as weak CAA and AVA in the back side of the decaying trough has increased surface pressure and subsidence. Initially this has lead to breaks in the stratus layer, with a broken strato-cu deck now encompassing most of central Indiana. The one caveat is far SE central Indiana where a weak low level boundary remains, as seen on satelitte imagery. In this area, isolated showers may develop this afternoon as a modest instability gradient develops. Any rainfall should be minimal/isolated, but cannot be ruled out nonetheless. Overnight, the main forecast problem will be the potential development of ground fog. This will work two-fold for central Indiana. In the far SE, dew points are not expected to fall quickly with the boundary just to the south. This boundary is also likely to limit surface winds as a nocturnal inversion sets up. This combination typically leads to patchy dense fog, especially over river valleys. The other method of fog formation could occur over northern portions of central Indiana, as model soundings have shown a continuing towards an inversion reestablishing tonight underneath clearing skies. A steady northerly wind at 5-10mph could limit decoupling of the boundary layer and largely prevent any fog concerns, but areas where winds fall below 5mph are expected to have patchy fog. Tomorrow, much of the same weather is expected in central Indiana, just with slightly cooler temperatures as central Indiana`s wind flow becomes largely out of the N/NW overnight, including marginal cold air advection. Any remaining stratus from overnight subsidence inversions will likely mix-out by the late morning, with scattered to isolated strato-cu remaining in the afternoon. This increased sunshine may lead to slightly warmer than forecasted temperatures, but given climatology of early November and consistent N/NW flow, temperatures have been capped in the mid 60s as of this issuance. && .LONG TERM (Thursday night through Wednesday)... Issued at 256 PM EST Wed Nov 6 2024 A fairly progressive pattern is expected is expected throughout the period. Broad surface high pressure will keep the area dry into the very early portion of the weekend. An upper level low currently in the process of cutting off over the Southwest will move quickly northeast through the Great Lakes late in the week and over the weekend, bringing first a warm front, followed by a narrow warm sector and cold front through the area late Saturday into Sunday - this will produce a period of widespread showers and perhaps a few thunderstorms, primarily Saturday night into early Sunday, though timing differences will necessitate chances lingering into Sunday evening. Ridging at the surface and aloft will reassert control thereafter, with continued above normal temperatures and dry conditions early next work week. Guidance then suggests, though differs significantly in timing and strength, that a much larger upper trough and stronger surface low will develop across the northern CONUS and move into the central Canadian provinces, with steady eastward progress of the upper trough pushing a stronger cold front through the area mid week next week. Despite the cold frontal passage, temperatures are likely to remain above normal throughout the forecast period, though depending upon the strength of the cold front next week, there is at least some chance of a brief drop to near or slightly below normal mid-month. && .AVIATION (00Z TAF Issuance)... Issued at 542 PM EST Wed Nov 6 2024 Impacts: - VFR at BMG/HUF/IND until around 06Z. MVFR overnight. - MVFR conditions overnight at LAF. - Patchy fog possible again late tonight BMG/LAF. - Return to VFR all locations after 071400Z. Discussion: GOES16 shows IND/BMG and HUF caught in an area of clearing between MVFR cloud decks over southern Indiana and over NW Indiana and Central IL. HRRR 925mb surface shows increasing RH through the overnight house as diurnal cooling takes place and the cold front across Central Indiana pushes farther southeast. This will lead to some brief VFR conditions in between these two cloud decks, but eventual MVFR cigs overnight across the forecast area. On Thursday, VFR conditions will return as high pressure arrives across the area. Forecast soundings at that time show a dry column with subsidence by late morning, returning conditions to VFR. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Puma SHORT TERM...Updike LONG TERM...Nield AVIATION...Puma
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
958 PM CST Wed Nov 6 2024 ...New MESOSCALE UPDATE, AVIATION... .MESOSCALE UPDATE... Issued at 956 PM CST Wed Nov 6 2024 Rest of tonight... Main concerns for the region will be the potential for areas of dense fog west of the I-55 corridor. Upper air/RAP/water vapor imagery indicate trough deepening over the Four Corners while Atlantic subtropical ridge continues to remain parked in the western Atlantic. This is keeping broad southwesterly flow over the region. Evening sfc/RAP analysis indicate sfc frontal zone draped across the northwest Delta. This pattern will favor some light rain showers through the overnight hours. Especially in areas that received rain & closer to the sfc frontal zone, dense fog could be a concern. HREF indicate some increased probs of 20-40% probs, with some potential even higher. With HRRR & other convective allowing model consensus on dense fog development, there is enough to warrant a HWO fog graphic. Added a "Limited" along & east of I-55 & "Elevated" to the west. This supports potential for some targeted Dense Fog Advisory, but some combination of stratus/fog limit confidence enough to add one for now. Updates are out. /DC/ && .DISCUSSION... Issued at 209 PM CST Wed Nov 6 2024 Tonight and Tomorrow... Late afternoon global guidance shows a closed low over the Four Corners Region with an associated deep trough axis located on the southern periphery of this sfc low. As this sfc low digs further south across the Four Corner Region heading into tonight, a anomalously strong sfc ridge aloft will continue to slowly shift east over the southeastern CONUS. At the same time, a stalled frontal boundary will remain in place over our CWA. This setup will allow for isolated scattered showers and thunderstorms to occur over northwestern portions of the area including our southeast Arkansas counties and some of our northeast Louisiana Parishes. Elsewhere, sky conditions will be generally cloudy with quiet conditions expected. HREF guidance is picking up low probabilities (around 10-20%) of patchy fog development. The persistent cloud cover should help keep overnight lows in the upper 60s range. Heading into Thursday morning, rain coverage will start to decrease across the Delta with quiet conditions expected heading into the afternoon as the aforementioned boundary continues to stall across our CWA. Highs will be in the upper 70s range across the Delta. Elsewhere, afternoon temperatures will peak in the low to mid 80s range. /CR/ Thursday night through mid next week: The primary weather concerns for the longer range forecast period are related to rainfall amounts in what will continue to be an unusually warm and humid weather pattern for this time of year. Looking ahead, forecast confidence is increasing for a significant weather pattern change as we go later into next week. While the southeast CONUS subtropical ridge will continue to have the strongest influence on the weather for our forecast area, a shortwave trough moving across the Central Plains will send a cold front toward the Lower MS Valley region by the weekend, and this will help transport tropical moisture associated with TC Rafael into our area. There is little concern for what should be a weakening tropical system in the central Gulf of Mexico to bring us weather impacts, but we`ll need to monitor for the potential of heavy rainfall given the combination of potentially favorable upper level jet support and tropical moisture. Getting a little more specific, the majority of ensemble guidance focus on northwest to northern portions of the forecast area for the most probable area heavy rainfall in the Fri night to Sat night time frame, but the entire area is still in play. In terms of rainfall amounts, confidence is quite low in this regard and will hold off on any special messaging for flooding potential for now. Will note that the ceiling for locally very heavy rainfall amounts is high given the anomalous moisture content available. Beyond the weekend, it looks like the ridge will build back over the area and maintain the unusually warm weather pattern through early next week, but as mentioned earlier, a weather pattern change is looking more likely later in the week. Guidance continue to show signals for a significant cold front to push through during the middle of next week. The front would bring stormy weather to our region followed by a significant intrusion of continental polar air. Confidence in this scenario remains greater than usual given the favorable MJO forecast and teleconnection indices. /EC/ && .AVIATION... (06Z TAFS) Issued at 956 PM CST Wed Nov 6 2024 Mixture of IFR to LIFR stratus & fog are expected overnight. There is some ongoing lower IFR stratus developing near the sfc frontal zone at GLH, with some more advecting in from the southeast near MEI, HBG & PIB currently. Flight restrictions will plummet to as low as LIFR areawide after 07/08-14Z. Some areas of fog could be dense at times, especially near GLH, GWO & west of JAN & HKS, with patchy dense fog psbl at other TAF sites. Expect conditions to improve to MVFR around 07/15-16Z & lift to VFR by midday to early afternoon. Winds will be light from the east-northeast. /DC/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 69 84 67 80 / 20 20 30 40 Meridian 67 82 66 80 / 10 20 20 30 Vicksburg 68 82 64 78 / 20 10 20 30 Hattiesburg 69 85 69 83 / 10 10 10 30 Natchez 68 83 66 80 / 20 10 20 30 Greenville 66 74 60 75 / 30 20 10 20 Greenwood 67 80 63 79 / 20 20 10 20 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$ DC/EC/DC
Area Forecast Discussion
National Weather Service San Francisco CA
319 PM PST Wed Nov 6 2024 ...New AVIATION, MARINE... .SYNOPSIS... Issued at 225 PM PST Wed Nov 6 2024 A Red Flag Warning will remain in effect through 5 PM Wednesday for interior portions of the Central Coast and through 7 AM Thursday across the Bay Area. Wind gusts between 30 to 40 mph will remain possible across the higher elevations through this evening before diminishing late this evening/overnight. && .SHORT TERM... (This evening through Thursday) Issued at 225 PM PST Wed Nov 6 2024 Strong offshore winds and critically dry conditions continue through the afternoon before winds gradually ease this evening. It has been a windy day throughout the Bay Area with widespread observed gusts between 35 to 50 mph. Mt. St. Helena West remains the big winner with a maximum gust of 88 mph recorded at 6:30 AM. Current observations show relative humidity values as low as 10% across the North Bay and as low as 15% across the rest of the Bay Area. The KSFO-KWMC pressure gradient peaked at -14.10 mb at 7AM this morning (shortly after that 88 mph gust was reported at Mt. St. Helena). Since then, the gradient has weakened (slightly) and is reporting a value of -13.30 mb as of 1 PM. GFS pressure gradient forecast guidance most closely resembles the current observed pressure gradient values (-11.6 compared to -13.3 at 1 PM). The GFS shows the pressure gradient gradually weakening heading into the evening hours and values dropping off more quickly overnight. This suggests that winds will ease more slowly through the evening before diminishing more quickly overnight. The NBM, WRF, and HRRR are in support of a similar scenario showings winds diminishing slowly through the evening before diminishing more rapidly overnight. However, continued poor overnight humidity recoveries will necessitate the continuation of the RFW through 7AM Thursday. Across the Central Coast, however, we see a slightly different story developing. Wind gusts across the interior Central Coast have been weaker than originally forecast with gusts peaking between 15 to 25 mph this morning/afternoon. Probabilistic NBM guidance shows only a 20% chance of winds gusting above 20 mph at 5 PM and a low <10% chance after 6 PM. That being said, winds are not the only contributing factor to RFW issuance with the other component being moisture/relative humidity. Overnight humidity recoveries across the interior Central Coast will be slightly improved compared to yesterday with poor to fair humidity recoveries at most sites. Given the combination of poor to fair humidity recoveries and light (< 6 mph) winds expected overnight, the decision was made to end the Red Flag Warning at 5PM today for areas within the interior Central Coast. If things continue to stay on track, the Red Flag Warning will be allowed to expire across the Bay Area at 7AM on Thursday. That being said, this is not free reign to partake in outdoors activities that may result in the wildfire development or spread as widespread near critically dry conditions and fuels will continue even after winds diminish Thursday morning. A mix of light offshore and onshore winds will continue throughout the day on Thursday with longer range NAM and GFS guidance showing the KSFO-KWMC gradient flipping back to positive (onshore) late Thursday evening. && .LONG TERM... (Thursday night through next Tuesday) Issued at 225 PM PST Wed Nov 6 2024 Beginning Thursday night, we will start to see increasing improvements in relative humidity recoveries with WRF guidance showing some potential for a (shallow) marine layer to return Thursday into Friday. As our fire weather conditions improve, so to do our rain chances heading into the weekend. The upper level trough over the Four Corners region that produced our prolonged offshore wind event will gradually start to progress eastward by late Thursday. In its place, upper level ridging will gradually expand over the West Coast Thursday and Friday bringing with it light, at times variable, winds. Ridging will be short lived with the pattern becoming more active/progressive the Saturday to Tuesday timeframe as a series of troughs enter into the West Coast. The first trough (Saturday into Sunday) will bring light rain (up to a few hundredths of an inch) to the far northern portions of Sonoma County. The second trough (Monday into Tuesday) looks to bring more widespread wetting rains to the entire Bay Area and Central Coast. As has been per the norm for our last few systems, the highest rain accumulations will be across the North Bay with accumulation totals gradually dropping off moving southward. Totals around half an inch remain possible across the North Bay, between a quarter to half an inch across elevated terrain of the Bay Area, and generally less than a quarter of an inch for all other areas. In the long run, the CPC has updated their temperature and precipitation outlooks to show temperatures leaning below average and precipitation above average through the end of November. && .AVIATION... (00Z TAFS) Issued at 318 PM PST Wed Nov 6 2024 High confidence VFR through the TAF period. Breezy and gusty winds N/NE winds will be the primary aviation concern. Models show some signals for LLWS over the North Bay terminals this evening, but should diminish before midnight. Overall winds will diminish overnight and will gradually turn back to an onshore component. Vicinity of SFO...VFR through the TAF period. Gusty N/NE winds up to 25 knots will diminish towards the evening and breezy sustained winds will remain until 06Z. Winds become relatively light to moderate through the remainder of the TAF period, and winds will turn back to NW by Thursday afternoon. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...VFR through the TAF period. Winds will continue to diminish into the evening becoming light to moderate. Winds will turn to NW by Thursday afternoon. && .MARINE... (Tonight through next Monday) Issued at 318 PM PST Wed Nov 6 2024 Northerly winds will gradually diminish through the day and turn light and variable on Thursday. Weaker winds and a decaying northerly swell will lead to an improved sea state. Breezy northwest winds will build again early next week. && .FIRE WEATHER... Issued at 241 PM PST Wed Nov 6 2024 Red Flag warnings persist across the Bay Area, with widespread verification being reported this afternoon. Sustained winds are from the NE at 15-30 mph with gusts as high as 70 mph in the higher elevations. The RH is generally between 10 and 20%. The dry, offshore winds have mixed down to the lower elevations and even the Oakland International Airport observation is reporting Red Flag Conditions (17% RH, 20G32MPH winds). It`s a different story in the Central Coast. Observations in the Santa Lucia Mountains, Gabilan Range and southern Diablo Range of Monterey and San Benito Counties are reporting RH in the 20-30% range with much weaker winds of 5-10 mph. For this reason, we have decided to end this section of the Red Flag Warning early. The Central Coast section is now set to expire after peak heating at 5 PM, while the rest of the Bay Area will remain in effect through 7 AM. While the Bay Area winds are running a little stronger than our forecast, the SFO-WMC gradient has started to decrease and all indications are that the winds will greatly diminish overnight for all but the North Bay Interior Mountains, where strong winds will likely hold on until sunrise. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Red Flag Warning until 7 AM PST Thursday for CAZ006-502>504-506- 508>510-512>515-529. Red Flag Warning until 5 PM PST this afternoon for CAZ517-518. PZ...Small Craft Advisory until 9 PM PST this evening for Pt Arena to Pt Reyes 10-60 NM. && $$ SHORT TERM...Kennedy LONG TERM....Kennedy AVIATION...SO MARINE...SO Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/nwsbayarea www.twitter.com/nwsbayarea www.youtube.com/nwsbayarea
Area Forecast Discussion
National Weather Service Norman OK
514 PM CST Wed Nov 6 2024 ...New AVIATION... .KEY MESSAGES... Updated at 454 PM CST Wed Nov 6 2024 -Heavy rain event possible tomorrow through Friday night -Cooler and drier for most of the weekend, then warmer && .NEAR TERM... (Rest of today and tonight) Issued at 220 PM CST Wed Nov 6 2024 Southeast surface winds will become more east and northeast this evening and overnight. The upslope flow is expected to result in some low cloud and perhaps fog development. Both the RAP and NAM model soundings indicate a decent chance of a modest saturated layer below a fairly steep inversion after 6Z. Perhaps northwest and west central Oklahoma have a better chance of fog develop during the overnight, so will add a mention of patchy fog for these areas. && .SHORT TERM... (Thursday through Friday night) Issued at 220 PM CST Wed Nov 6 2024 If low clouds are widespread by Thursday morning, it`s possible that Thursday daytime high temperatures may be on the warm side, especially across western Oklahoma. With a slanted/long inversion, and a November sun angle, warming may be difficult. Meanwhile, there appears to be a PV anomaly that moves across northern Mexico on Thursday and into Thursday night. This should help with the eastward movement of the upper low over Arizona and New Mexico, despite upstream and downstream ridging. Although boundary layer instability is expected to remain low to nill Thursday into Friday, there should be enough elevated instability for thunderstorms and enhance rainfall rates. Currently, southwestern Oklahoma and parts of western north Texas have higher storm total rainfall amounts (2-4 inches) Thursday afternoon through Friday afternoon. It still remains possible that the rainfall may be occur over a long enough duration, that and flooding will not be overly impactful. At this time, it appears that rain and embedded thunderstorms will be more widespread across western Oklahoma and northern Texas, generally from late Thursday afternoon into Friday morning. The precipitation should gradually shift eastward Friday morning through Friday overnight. && .LONG TERM... (Saturday through next Tuesday) Issued at 220 PM CST Wed Nov 6 2024 It still appears the upper-level low moves northeast of the area Saturday into early Sunday. A fast moving shortwave trough may bring a weak wind shift on Monday, but little if any cooling will occur behind the boundary. Still appears that another storm system will impact the area late Tuesday into Wednesday. Issued at 228 AM CST Wed Nov 6 2024 The upper-level low will finally kick out into the Plains on Saturday, bringing a clearing cold front behind it. Rain chances will diminish throughout the day. Expect rather cool temperatures beneath the cold air aloft on Saturday. Sunshine returns on Sunday and Monday with shortwave ridging. Temperatures will (stop me if you`ve heard this before) quickly recover to about 10 degrees above normal on Monday and Tuesday. Another longwave trough will approach the Plains toward the middle of the week, which could bring precipitation chances with it. Meister && .AVIATION... (00Z TAFS) Issued at 454 PM CST Wed Nov 6 2024 VFR conditions will continue this evening with east winds shifting to the northeast. Expect to see widespread stratus develop overnight, mainly MVFR ceilings, but no out of the question to see some IFR as well. Could also see some patch fog across the west after midnight with CSM having the best chance and have maintained a period of fog at that TAF. Ceilings will be slow to improve through the morning and many of the sites will maintain MVFR conditions through the day Thursday. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 46 63 52 62 / 0 10 60 80 Hobart OK 45 62 49 61 / 0 40 90 90 Wichita Falls TX 49 65 58 65 / 0 40 80 90 Gage OK 42 55 41 51 / 10 30 90 90 Ponca City OK 43 61 46 59 / 0 0 40 60 Durant OK 51 71 58 66 / 0 20 40 60 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && $$ NEAR TERM...06 SHORT TERM...06 LONG TERM....06 AVIATION...30
Area Forecast Discussion
National Weather Service Phoenix AZ
541 PM MST Wed Nov 6 2024 .UPDATE...Updated Aviation Discussion. && .SYNOPSIS... A weather system centered near the Four Corners will bring cooler temperatures with some places dipping below freezing overnight tonight across the higher terrain. Temperatures will warm up for the end of the week with highs returning to near normal readings by Sunday. Dry conditions will prevail for the end of the week and into the beginning of next week. && .DISCUSSION... Latest satellite WV imagery and RAP analysis showed a potent upper level low centered over the Four Corners, while an associated cold front continued to sag southward across southern Arizona. Behind this front, visible satellite showed mostly clear skies prevailing across the majority of the forecast area. Dry conditions will persist through the rest of today across the CWA, while below normal temperatures only top out in the upper 60s to low 70s this afternoon across the lower deserts. This weather system has brought gusty winds to region, particularly down along the Lower Colorado River Valley where peak wind gusts today have reached upwards of around 40-50 mph. However, winds continue to weaken as gradients gradually relax. The latest HREF shows the greatest probabilities (~40-60%) of wind gusts in excess of 40 mph are mostly confined to ridgetop locations such as the Chocolate Mountains, while lower elevation areas along the Lower Colorado River Valley have already seen these probabilities drop off substantially (now < 20%). Given this and the fact that observed wind gusts in the aforementioned area have already weakened below 40 mph, have decided to go ahead and cancel the Wind Advisory. Nonetheless, some gusts upwards of 25-35 mph will remain possible through the rest of the afternoon before relaxing this evening as the nocturnal inversion sets up. This low pressure system will also act to reinforce below normal temperatures for us as it ushers in cooler weather into the region. Overnight lows tonight will dip into the low to mid 40s across the lower deserts with some of the colder desert spots dipping into the 30s. Higher terrain areas will stand a good chance of dipping below freezing tonight. NBM probabilities for freezing temperatures increases to around 70% for places like Globe and San Carlos as well as the higher elevations of Joshua Tree National Park. As a result, Freeze Warnings are in effect for these areas. The upper level low will dig a bit more southward into Arizona before exiting going through the day Friday. In its wake, weak ridging will shift into the southwest CONUS and will promote rising heights for the end of the week and into the beginning of next week. Global ensembles show good agreement that 500 mb heights will rise to upwards of 576-579 dm this weekend with temperatures in turn warming up for the end of the week. Temperatures will return back to near normal readings by Sunday as highs across the lower deserts warm into the upper 70s to low 80s. Dry conditions will prevail for the end of the week and into at least the beginning of next week. Ensemble cluster analysis show increased forecast uncertainty during the early part of next week as a trough is expected to move through the Intermountain West. This uncertainty continues to be reflected in the NBM temperatures with around a 10 degree spread in the interquartile range early to mid next week. Despite the forecast uncertainty, guidance favor dry conditions persisting with very low PoPs across the northern Arizona high terrain. && .AVIATION...Updated at 0040Z. South Central Arizona including KPHX, KIWA, KSDL, and KDVT: N-NE winds will continue at all terminals until around 06Z when they will shift more N-NW, to W-NW at KPHX. Wind gusts will subside this evening, but speeds will remain elevated through around midnight before weakening. Confidence in wind directions Thursday morning become less certain, with potential periods of light variability, a persistent northerly component, to a brief period of easterly winds. Winds at all terminals will eventually shift westerly Thursday afternoon. Mostly clear skies will prevail, aside from occasional FEW to SCT mid-level clouds Thursday. Southeast California/Southwest Arizona including KIPL and KBLH: Wind gusts should relax over the next few hours with more modest gustiness returning Thursday afternoon. Wind speeds at KIPL will become eventually become light at KIPL while KBLH remains elevated with speeds up around 9-12 kts. Northerly winds will prevail at KBLH while KIPL sees W-NW overnight and N again during the day Thursday. SKC will prevail. && .FIRE WEATHER... Well below normal temperatures will prevail through the end of the work week. A mostly dry weather system will dive south into the Desert Southwest today and linger through Thursday. This system will bring breezy to locally windy conditions across the western districts for much of today, with wind gusts along the Lower Colorado River Valley and portions of Southeast California to between 35-45 mph. Light shower activity will be possible across the eastern Arizona higher terrain through Thursday afternoon, but CWR for the high terrain of the eastern districts is 5% or less. MinRHs today will fall in the upper single digits up to around 15% and will mainly fall into the teens on Thursday across the lower deserts, with readings closer to 20-30% over higher terrain areas each day. For late this week into the weekend, dry conditions will persist with weak high pressure eventually pushing temperatures from below normal into the normal range over the weekend. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...Freeze Warning from midnight tonight to 9 AM MST Thursday for AZZ557-558-560-562. CA...Freeze Warning from 11 PM this evening to 8 AM PST Thursday for CAZ560. && $$ DISCUSSION...Smith AVIATION...Benedict FIRE WEATHER...Whittock