Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/08/23


Area Forecast Discussion
National Weather Service Dodge City KS
523 PM CST Tue Feb 7 2023 ...Updated Aviation... .SHORT TERM...(This evening through Wednesday night) Issued at 1246 PM CST Tue Feb 7 2023 Key messages in the short term -Upper level low will bring cloud cover and small chances of rain in south central Kansas -Winds increasing in wake of a cold front moving through Wednesday night 18Z observations are showing an upper level low situated in southern New Mexico with the upper level winds generally out of the southwest. The jet stream currently is split flow with the polar jet entrenched over Canada. At the surface a 1026 mb high in eastern Colorado is keeping the winds light and the skies mainly clear. Tonight as the upper level low moves into west Texas mid level clouds will build in from south to north during the overnight hours. Winds should continue to stay light and stay generally out of the north to northwest as the surface low moves towards Dallas. Overall conditions should stay quiet as lows fall into the 20s. Wednesday the main forecast challenge will be where (if any) rain should fall during the day. The upper level trough will turn neutral as the upper level low moves into northwest Texas. The main mid level lift from the RAP and NAM keeps the best lift mainly in Oklahoma and eastern Kansas. As the 700 mb low approaches Oklahoma City towards mid afternoon this will give the best chance of rain around Barber county. Temperatures will cool on the backside of the low towards late afternoon which may introduce a brief mixed phase period around southeast Barber county. Most of the precipitation should be out of the CWA after sunset. Wednesday night as the first system exits another upper level trough will rotate in from the northwest. This will bring in a cold front during the night and post frontal winds will increase as we get towards Thursday morning. By sunrise we could already be experiencing wind speeds of 20-30 mph with higher gusts and wind chills could be in the teens. .LONG TERM...(Thursday through Tuesday) Issued at 129 PM CST Tue Feb 7 2023 Key messages in the long term -Strong surface winds on Thursday -Warm up and elevated fire risk far southwest on Saturday -Rain potential early next week Thursday will be a cold windy day as strong northwest winds pick up from the late morning to early afternoon. EFI and shift of tails are both showing a higher end wind event for areas especially along the Colorado border which could be approaching high wind criteria. Widespread wind speeds look to be 25-35 mph with gusts over 50 at times especially for our western counties. Otherwise with northwest flow aloft and some lift in the 700 mb zone coming in during the day we could see some scattered sprinkles/flurries during the day. 850 mb temperatures will be around -5 (C) and high will only get to the middle 30s to low 40s. Friday into Saturday should bring the return of warmer temperatures as an upper level trough moves into the central plains. Towards Saturday with winds increasing out of the southwest and drier air coming in from New Mexico we could see elevated fire danger for areas south and west of Garden City during the afternoon. Forecast updates are showing RH values below 15% around Elkhart. High temperatures on Saturday should reach into the upper 50s to mid 60s. Early next week deterministic and ensemble models are showing an upper level low moving into the southern plains on Tuesday and increasing chances of rain especially for Oklahoma and Texas. Confidence in southwest Kansas getting rain is low at this time as there is a wide spread in ensemble output QPF along with the convective parameters favoring a large thunderstorm event in Texas which would track the upper level low further south and lower our POP chances and QPF output. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 523 PM CST Tue Feb 7 2023 VFR flying conditions this TAF cycle for all terminals. Current NNE winds in the 8-12 kt range will relax to light and variable over the next hour or two, and persist through the end of the period. && .PRELIMINARY POINT TEMPS/POPS... DDC 24 51 28 41 / 10 10 0 10 GCK 22 49 27 38 / 0 10 0 10 EHA 27 52 27 40 / 10 0 0 10 LBL 24 51 26 42 / 10 10 0 10 HYS 24 51 29 41 / 0 10 0 10 P28 29 49 30 47 / 10 40 20 10 && .DDC WATCHES/WARNINGS/ADVISORIES... High Wind Watch from Thursday morning through Thursday afternoon for KSZ061-074-084. && $$ SHORT TERM...Tatro LONG TERM...Tatro AVIATION...Springer
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
536 PM CST Tue Feb 7 2023 ...New AVIATION... .SHORT TERM... (Tonight through Wednesday night) Issued at 212 PM CST Tue Feb 7 2023 Per latest mesoanalysis and radar imagery, the frontal boundary has raced out to the east of Del Rio already, but remains held up to the north of the Hill Country from a Rocksprings to Kerrville to Mason to San Saba line. This boundary will likely get held up a bit due to strong moisture advection north and westward from the Gulf of Mexico up through the I-35 Corridor and into the Hill Country and Southern Edwards Plateau. Rich surface moisture for early February, with dewpoints in the 60s east of this boundary are already in place. Add in the fact that PWATs will be approaching 1.2 to 1.4", a good 2 SD`s above the norm, we can expect some rather decent rainfall rates with any showers that can become more convectively driven. At the moment, most of the activity over the region remains showery in nature, but as daytime heating continues and instability increases with some breaks in the overcast, we should see some more lightning strikes here and there through the afternoon hours. Latest CAMs have a pretty good handle on the timing of the front, with the HRRR likely the top dog when it comes to current positioning of the frontal boundary. As we move into the later evening hours, the front will finally start to push southward into the Hill Country/northern CWA, making it`s way into the Austin and San Antonio metros between 02Z-05Z. The latest 18Z HRRR indicates instability will be somewhat lacking despite deep moisture, but this is probably largely due in part to a lack of substantial surface heating. With a positively tilted 500mb trough set to swing through the CWA tonight into Wednesday, the severe threat is fairly limited, but with some stronger winds aloft, any storm that can get rooted in the boundary layer and tied to the advancing cold front could result in some damaging wind gusts in excess of 60 mph. Hail does not appear to be a threat at all with this setup, while the tornado threat is quite low as well, although not non-zero. If a storm were to spin-up, the window would be quite narrow, primarily between 12Z-15Z as the front moves east of the I-35 Corridor and into the Coastal Plains tomorrow morning. Ultimately, the bulk of the severe threat should be over the Coastal Plains and out of our CWA on Wednesday afternoon, with locally heavy and much-needed rainfall looking like a good bet tonight over a large portion of the region. Once the front moves through, expect some rather gusty winds out of the northwest, likely 15-25 mph with higher gusts to 30-35 mph out over the Rio Grande Plains where some elevated fire weather conditions may develop Wednesday afternoon. Temperatures will be cooler for most, but we are not expecting a significant drop off behind this front. However, you will definitely notice a drop in the humidity as much drier air filters into the region. Highs will range from the mid to upper 50s north to the mid to upper 60s south. Wednesday night looks to be much cooler with lows dipping into the mid to upper 30s and lower 40s, as the pressure gradient relaxes with a sfc high sliding through. The light winds won`t last long as our next front is progged to arrive just beyond the short term forecast. && .LONG TERM... (Thursday through Tuesday) Issued at 212 PM CST Tue Feb 7 2023 Thursday into Friday will see an upper trough push from near the Four Corners region and into the southern Plains, bringing a stronger cold front into south-central Texas. This frontal passage appears to be dry as moisture will be lacking behind the Pacific front we are seeing in the short term, but we can expect stronger northwesterly winds, possibly reaching or exceeding wind advisory criteria based on what forecast soundings show potentially mixing down to the surface. The front`s likely arrival during the evening and early overnight hours may help mitigate how much mixing we see within the boundary layer, however. Colder and drier air will filter in behind the front, with highs on Friday ranging from the low 50s to low 60s and lows early Saturday morning ranging from the upper 20s to low 30s. We will have to monitor for elevated to near- critical fire weather potential on Friday afternoon across our western counties where relative humidity could dip as low as the teens and northwesterly winds may remain elevated until the evening hours. Upper level ridging then builds in for the weekend with a warming trend heading into early next week. Meanwhile, another strong upper trough/closed low will be moving down the California coast, eventually making its way into the southern Plains by early Tuesday. Chances for showers and storms will be on the increase once again ahead of this upper low and associated Pacific front, with clearing and drying conditions in its wake heading into Wednesday of next week. && .AVIATION... (00Z TAFS) Issued at 534 PM CST Tue Feb 7 2023 Gusty northerly wind will continue at DRT through the period as it sits behind the cold front. Could see some showers between 08-10Z, but conditions should remain VFR through the period. More complicated weather for I-35 sites as showers and thunderstorms continue tonight into Wednesday. IFR ceilings are expected at all sites around 02-03Z, with possibly some MVFR visibilities with showers or storms. Isolated thunder will be possible after 02-03Z, but the best chances for prevailing TSRA will be after 05-06Z, possibly later as we see how storms progress. Ceilings improve to VFR after 18-21Z Wednesday. Northwesterly wind will be breezy behind the front, decreasing close to 23Z. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 49 59 41 71 / 80 80 0 0 Austin Bergstrom Intl Airport 49 58 38 70 / 80 80 0 0 New Braunfels Muni Airport 50 62 38 71 / 80 80 0 0 Burnet Muni Airport 46 56 39 68 / 80 80 0 0 Del Rio Intl Airport 48 68 41 75 / 30 20 0 0 Georgetown Muni Airport 48 57 39 68 / 80 80 0 0 Hondo Muni Airport 49 64 38 71 / 70 60 0 0 San Marcos Muni Airport 49 60 37 70 / 80 80 0 0 La Grange - Fayette Regional 54 60 39 69 / 80 70 0 0 San Antonio Intl Airport 50 61 41 69 / 80 80 0 0 Stinson Muni Airport 52 64 42 71 / 80 70 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...MMM Long-Term...Gale Aviation...27
Area Forecast Discussion
National Weather Service Goodland KS
732 PM MST Tue Feb 7 2023 .UPDATE... Issued at 726 PM MST Tue Feb 7 2023 Overall forecast remains on track. Went ahead and added in patchy blowing dust across southern portions of Kit Carson county and throughout Cheyenne County Colorado for Thursday as office dust parameters continues to indicate the potential. The relative best area to see blowing dust will be across SW portions of Cheyenne County Colorado where snow has already been absent for the past few days. The other change that was made was to extend slight chance pops east (mainly along and north of Highway 36 for Thursday morning as Hi-Res guidance is picking up on a convective band of snow showers originating from the Nebraska Panhandle and traversing southeastward across the area. && .SHORT TERM...(This evening through Wednesday) Issued at 242 PM MST Tue Feb 7 2023 At the start of the short term period, the latest RAP analysis shows an upper air low over the central AZ/NM border with a ridge over the Pacific Northwest. Current satellite imagery and surface observations display sunny skies and dry conditions across the region with some snow cover still seen in a good portion of the CWA. Forecast guidance show the low advancing northeastward into NM with the ridge moving over the Northern Plains. On Wednesday, models depict the upper air low moving over the CWA by the afternoon and then opening up into a wave as another trough moves into the Pacific Northwest. During the evening hours, this trough moves eastward into the Northern Plains with the wave being absorbed into the trough overnight. At the surface, dry conditions are expected for the remainder of Tuesday for the CWA with a localized surface high expected to move into the CWA causing light winds as well. On Wednesday, models show a surface low moving from eastern TX up through central MO throughout the day. With this system, a cold front looks to move through the region bringing chances for a wintry mix to the western portion of the CWA that will transition to all light snow showers overnight. Snowfall accumulation for late Thursday expect to be a few tenths at most. Behind the cold front, winds become north-northwesterly and start to speed up overnight particularly in the western half of the CWA with soundings showing potential wind gusts up to around 40 kts. Will continue to monitor this as winds look to increase more beyond the short term period. The Tri-State Area looks to see overnight lows in the upper teens to the lower 20s. Daytime highs on Thursday expect to be in the lower 40s to lower 50s followed by overnight lows in the upper teens to upper 20s. .LONG TERM...(Thursday through Tuesday) Issued at 223 PM MST Tue Feb 7 2023 Main focus for this part of the forecast is the high wind potential Thursday behind the cold front. An upper level low will move south across the Plains Thursday behind the cold front from Wednesday night. Ahead of the upper level short wave trough northwest winds will increase. Data is indicating the low level winds will be strongest during the morning, then decline through the afternoon as the trough shifts into the Southern Plains. The peak wind gusts look to be around the 800mb level, which is close to the top of the mixed layer. Soundings in East Central CO show the gusts of 60 MPH or higher being in the top half of the mixed layer. One complicating factor is the uniform cloud deck expected during the day. However lapse rates are rather steep, so am thinking there should be some mixing occurring. Another complicating factor is the influence the snow field over Northern CO will have on the winds. The CAA off the snow could cause an inversion to form just above the surface which could limit the wind gust potential. There is also the unknown influence of how much snow will melt today and tomorrow ahead of the high winds. Looking at the potential for wind gusts of 60+ MPH, models have high likelihood of these winds occurring over East Central CO, extending into West Central KS. Given the above considerations, was initially skeptical of issuing a watch. However the model potential for high winds was enough reason to atleast issue a watch. Regarding wind potential, the strongest gusts look to occur over the western part of the forecast area. The strongest gusts look to occur during the mid to late morning, maybe into the early afternoon, before the winds begin to trend down. There will be some weak lift occurring during the day along with steep lapse rates. Am thinking the steep lapse rates will be the main contributor to snow showers forming. Given the high winds, we could see snow squalls occur. Blowing dust may occur, however the main threat area looks to be more over Southeast CO. Over East Central CO the surface winds may not be quite strong enough, and the lapse rates may not be steep enough to allow the dust to go very far vertically. Beyond Thursday a short wave ridge moves over the forecast area for the weekend. This will allow warmer weather into the forecast area. Early next week another upper level moves across the Southern Plains. The GFS continues to move the trough well south of the forecast area, while the ECMWF has it further north over the TX/OK Panhandles. This setup looks like a split flow pattern, which is usually not favorable for precipitation for the forecast area. As such am skeptical of the current forecast for precipitation. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 334 PM MST Tue Feb 7 2023 VFR conditions are forecasted for the entire TAF period as high pressure settles in across the area leading to the clear skies and light/variable winds. Winds will slightly strengthen mid to late morning Wednesday with sustained winds around 13 knots out of the SW. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...High Wind Watch from late Wednesday night through Thursday afternoon for KSZ027-041. CO...High Wind Watch from late Wednesday night through Thursday afternoon for COZ090>092. NE...NONE. && $$ UPDATE...Trigg SHORT TERM...076 LONG TERM...JTL AVIATION...Trigg
Area Forecast Discussion
National Weather Service Grand Rapids MI
1011 PM EST Tue Feb 7 2023 LATEST UPDATE... Update .UPDATE... Issued at 1010 PM EST Tue Feb 7 2023 Forecast is on track tonight. The clearing line is steadily moving across the forecast area. By 1am, most areas will be clear based on the current movement. Winds will subside a bit late tonight, falling below 10 knots in the lowest 2,000 feet. As this occurs, we may see some light fog develop, especially down towards I-94. At this point, we are not expecting fog to become a significant issue. Normal lows for tonight are in the teens in most areas. We will be warmer than normal tonight with lows in the 20s. && .DISCUSSION...(This evening through next Tuesday) Issued at 308 PM EST Tue Feb 7 2023 - Freezing rain risk later Wednesday night into Thursday morning The pattern becomes favorable for an increased risk for freezing rain later Wednesday night into Thursday. High pressure will be situated over eastern Ontario...funneling shallow colder air into central Lower MI. At the same time a warm front will be lifting northward into Lower MI leading to overrunning precipitation. Forecast soundings around Big Rapids and Clare show an above freezing layer at 850 mb with a subfreezing layer below at 10z Thursday. Further south...surface temperatures are expected to remain above freezing. By 14z Thursday...above freezing surface temperatures should exist throughout the CWA. I don`t see the Ludington...Baldwin to Clare region getting out of the mid 30`s Thursday given this setup. If the freezing rain persist longer than expected...impacts would increase accordingly. SPC HREF FRAM shows freezing rain amounts remaining below a tenth of an inch for this region. - Strong wind gusts Thursday afternoon and evening We are seeing a trend in the models for a possible trop fold event Thursday afternoon. A PV anomaly shifts up the west side of Lower MI during this time. Cross sections through it show a lower of the 2 PVU heights here in lower MI then. The 500 mb winds are running 80 to 100 knots. Winds at 850 mb increase to 50 to 60 knots and 925 mb values 40 to 50 knots. It`s interesting to see some of the models showing 0 to 3 km CAPE moving in from the south...which may enhance the low level mixing. Either way most models are showing southern parts of the CWA featuring surface winds topping 35 knots with some showing over 40 knots. Thus confidence is increasing that we will see wind related impacts then and we appear to be headed toward a wind advisory. - Heavier qpf Wednesday night into Thursday with small thunder risk A strengthening warm front will be lifting northward into the CWA Wednesday night. PWAT values along this front are modeled to be over an inch. Stronger FGEN is noted as well with favorable upper level divergence. All this will lead to a band of steady precipitation that will be moderate in intensity at times. A dry slot will work in from the south Thursday but the upper low tracks in for Thursday night. Ensemble forecasts for Grand Rapids show 24 hr mean values of 0.75 to near an inch from the ECMWF...GFS and Canadian models. In addition...there is a small potential for a thunderstorm or two. MU CAPE values from several models like the Namnest and RAP are showing several hundred joules in the southern zones 09z to 12z Thu. This instability looks to be elevated. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 725 PM EST Tue Feb 7 2023 An area of MVFR ceilings persist across much of Southern Lower Michigan at 00z including all of the TAF sites. We should see a clearing take places as these clouds are not lake generated. A clearing out of the low clouds is expected to occur from west to east from MKG around 03z to the eastern TAF sites of LAN and JXN between 06z and 09z. Mainly clear skies are then expected late tonight and on Wednesday. Not out of the realm of possibilities to see some light fog or haze due to a moist boundary layer (via a melting snow pack) late tonight and on Wednesday. && .MARINE... Issued at 308 PM EST Tue Feb 7 2023 We will issue a gale watch. Based upon the strengthening winds and increasing mixing heights confidence is growing that we will see gale force winds for at least parts of the nearshore zones. Southern zones will be closer to the core of highest winds with this system. The main window for the stronger winds will be during the day on Thursday. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...Gale Watch from Thursday morning through Thursday evening for LMZ844>849. && $$ UPDATE...Duke DISCUSSION...MJS AVIATION...Duke MARINE...MJS
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
856 PM CST Tue Feb 7 2023 ...New MESOSCALE UPDATE... .MESOSCALE UPDATE... Issued at 856 PM CST Tue Feb 7 2023 In the wake of light showers earlier today, areas of dense fog quickly developed across portions of the Pine Belt this evening. While fog may modulate to low clouds at times, high res guidance has been consistently progging a broad area of dense fog across southeast MS overnight as winds still remain rather light at many locations. We have posted a Dense Fog Advisory for much of this area, as some evening travel is already being impacted. Fog may potentially spread more northward closer to daybreak. Otherwise, the area of light showers is beginning to make its way out of the area, so PoPs for the rest of tonight have been adjusted accordingly. We can`t rule out additional isolated light showers through the rest of the night, but low clouds and fog will be the prevailing condition over a larger area. Forecast updates have been posted. /DL/ && .DISCUSSION... Issued at 333 PM CST Tue Feb 7 2023 Tonight and Wednesday. Light rain continues to spread north and east across the area. Leaned heavily on the HRRR for the rain forecast which has the rain tapering off by early morning. Guidance was also showing fog for tonight, mainly in the I-59 corridor, so went with it. Wasn`t confident in widespread dense fog at this time, so went with patchy fog in the zones. Could see stratus or fog developing at this point. QPF amounts for tomorrow were less, so opted to remove the flood risk for the afternoon. Overall, not real changes to the short term forecast. Guidance pops and temps were good. Models continue to show the surface low deepening as it tracks northeast. Looking for more warm advection type showers to develop ahead of the system in the morning, so left slight chance values in the east through noon. Looks like most of the convection won`t move in until the late afternoon, generally hi-res models shows CAPE increasing in the afternoon with values around 1000 ahead of the boundary. There were a few other instability parameters increasing into the late afternoon that suggests the southwest portions of the area generally south of I-20 may be primed by the late afternoon. Right now, it doesn`t look like much convection will develop ahead of the boundary, so expecting most of the activity in the later afternoon. /07/ Wednesday night into next week ...Showers and storms will be ongoing to start the mid and long range forecast period Wednesday night including the risk for strong to severe storms through the overnight. Heavier rains are possible south of I-20 where a locally higher likelihood for isolated flash flooding remains possible. In this area, deeper moisture, somewhat slower storm motions, and a less meridionally orientated band of storms could result in both higher rainfall rates and longer duration of thunderstorm activity. Urban and low lying areas, as is typically the case, would be most at risk for flash flooding. With local rivers remaining high, additional rainfall may prolong river flooding issues across the area. As storms clear with the passage of the cold front, a seasonably cool and and dry airmass will become entrenched into the weekend. Temperatures Thursday will be 10-15 degrees cooler than Wednesday amidst steady northwest flow and cold advection with overnight lows down into the 40s F. Friday temperatures continue to trend cooler with surface high pressure in control with highs mostly in the 50s F and lows by Saturday and Sunday morning near and below freezing for much of the area. By Sunday afternoon, the center of the surface high migrates east of our area and southerlies return, resulting in moderating temperatures and highs near 60 F. The next chance for rain likely holds off until next week when an upper trough will be approaching Monday into Tuesday. This is around a week out and forecast confidence is low with considerable differences amongst the forecast guidance, but there does appear to be a risk for thunderstorms and we will be monitoring for any strong/severe weather risk particularly after we get through the mid- week event and the eventual outcome becomes more clear. /86/ && .AVIATION... (00Z TAFS) Issued at 540 PM CST Tue Feb 7 2023 VFR conditions prevail across the majority of the area, with patchy IFR/MVFR conditions in fog and light rain over mainly east MS. This area of rain will move out of the area through the evening, but may be accompanied by ceiling/visby reductions around MEI/GTR. Overnight into Wed morning, fog and low clouds will spread northward across the area, with widespread IFR/LIFR conditions around daybreak. Visibilities will quickly improve in most areas by mid-morning, but ceilings may be a bit slower to improve. Though most areas will return to VFR by the afternoon hours, MVFR ceilings may hang around, especially across east MS. Additional showers are possible across south MS in the morning, then generally along and west of the MS River during the afternoon, with some thunder also possible by that time. /DL/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 59 77 51 65 / 10 40 100 20 Meridian 57 75 55 66 / 30 30 80 50 Vicksburg 59 79 48 65 / 10 50 100 10 Hattiesburg 60 77 59 65 / 20 50 80 60 Natchez 60 78 51 66 / 10 60 100 10 Greenville 57 73 46 63 / 10 70 100 10 Greenwood 57 74 51 63 / 10 60 100 10 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...Dense Fog Advisory until 9 AM CST Wednesday for MSZ055>058- 062>066-072>074. LA...None. AR...None. && $$ DL/07/LP
Area Forecast Discussion
National Weather Service Memphis TN
846 PM CST Tue Feb 7 2023 ...New UPDATE... .UPDATE... Issued at 824 PM CST Tue Feb 7 2023 A quiet night before shower and storms move into the area for Wednesday. We are still in a Marginal to Slight Risk of Severe Weather on Wednesday. Greatest chances for storms will be Wednesday afternoon with damaging winds and heavy rain being the main threats. No major changes made to the forecast. && .SYNOPSIS... Issued at 345 PM CST Tue Feb 7 2023 A strong upper level low pressure system will lift from Texas into the Ozarks on Wednesday. Warm and humid air from the Gulf of Mexico will build north through the Midsouth in advance of this system. Scattered showers will develop early in the day, becoming most numerous over northeast Arkansas and the Missouri bootheel. By late afternoon Wednesday, thunderstorms will develop over eastern Arkansas, and progress through most of the Midsouth Wednesday evening. There is a Slight Risk for severe thunderstorms Wednesday afternoon and evening over the Mississippi River delta south of Memphis, and over north central Mississippi. There is a Marginal Risk over the remainder of the Midsouth. The primary severe weather threats will be damaging winds. A few brief tornadoes will be possible, especially over the Slight Risk area. Flash flooding will be possible, especially over northeast Arkansas and the Missouri bootheel, where rain will likely get an early start to the day. && .DISCUSSION... (This evening through next Monday) Issued at 345 PM CST Tue Feb 7 2023 GOES water vapor imagery shows a deep upper low near the NM bootheel at 2045Z. A pronounced shortwave was evident along the southwest periphery of the upper low. This system will track east to west Texas by 18Z/Noon CST Wednesday, becoming neutrally- tilted in the process. An elevated warm conveyer belt over the eastern third of TX will extend northeast to Ozarks. The operational NAM model depicts an east-west oriented 925mb warm front over northern AR during the morning and early afternoon. Persistent flow of higher theta-e air orthogonal to this slowly lifting elevated front will lead to a potential of heavy rainfall over far northeast AR and the MO bootheel through early afternoon Wednesday. Although instability will modest, a plume of precipitable water values nearing 1.5 inches should lead to efficient rainfall rates. Following coordination with WFOs Paducah, Springfield and Little Rock, a Flood Watch has been issued for far northeast AR and the MO bootheel for Wednesday and Wednesday night. Over the remainder of the Midsouth, Wednesday`s daytime storm chances will be more conditional due to shortwave ridging aloft. Expect some cloud breaks to allow surface temps to warm above NBM guidance south of I-40. Dewpoints in this area will also warm to the lower to mid 60s, yielding mixed layer CAPE of 500 to 1000 J/kg. NAM 3km soundings depict the presence of an elevated mixed layer (EML), sufficient to cap surface based convection. As is often the case, HRRR soundings don`t depict an EML. As such, the HRRR is more prone to develop scattered storms along a northward lifting warm front during the afternoon. It should be noted that the 18Z HRRR has backed off the warm sector afternoon convection slightly. By 00Z Thursday/6 PM Wednesday, the southern lobe shortwave will pivot around to the southeast perimeter of the upper low and eject through AR during the evening. A 1001 mb surface low will track just northeast of the main upper low, lifting into southern MO by 9 pm, where it become occluded. Nonetheless, the presence of the ejecting shortwave and frontal reflection will likely maintain strong frontal convergence through mid to late evening over the Midsouth. If mixed layer CAPE of 500 to 1000 J/kg persists into the evening south of I-40 to 03Z as the HRRR suggests, a damaging wind and short-lived tornado threat will continue into midevening. With 50 to 80 kts of 0-6km bulk shear, the kinematics with this system are well-established. Cool season instability is difficult to model this far in advance, and it is instability that will determine the extent of the severe threat late Wednesday, particularly past sunset. The exit of Wednesday night`s system will be hastened by an upstream northern branch trough dropping into the central and southern Great Plains by Thursday afternoon. This trough will lift into the Ozarks on Friday. Isolated rain showers will develop near the upper low and extend into the Midsouth. Cooler temperatures will follow for Saturday, before upstream ridging arrives from the southern plains on Sunday. Sunday`s high temps should prevail near normal. Temperatures should warm further early next week, in advance of another upper level closed low. PWB && .AVIATION... (00Z TAFS) Issued at 552 PM CST Tue Feb 7 2023 A cold front is currently draped over MEM and MKL, where winds have gone calm. The front will sag a little further south over the next couple of hours with winds shifting to the northwest at both MEM and MKL. SHRAs will hang back behind the front with no impacts on station through late tomorrow morning. The main story will be lowering CIGs overnight behind the front, where they could go as low as IFR. Some light fog is also possible. A warm front will lift back north tomorrow afternoon and CIGs may lift back to MVFR or VFR for a few hours before the main line of SHRAs and TSRAs arrive after 09/00Z tomorrow. AC3 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...Flood Watch from 6 AM CST Wednesday through late Wednesday night for ARZ009-018. MO...Flood Watch from 6 AM CST Wednesday through late Wednesday night for MOZ113-115. MS...None. TN...None. && $$ PUBLIC FORECAST...MJH AVIATION...AC3
Area Forecast Discussion
National Weather Service Pueblo CO
313 PM MST Tue Feb 7 2023 .SHORT TERM...(This evening through Wednesday) Issued at 309 PM MST Tue Feb 7 2023 Relatively quiet conditions are expected this forecast period. The upper level system can still be seen slowly moving east, just to our south. While this does remain close to southern CO, the drier air which has been in place will continue to limit any precip development across the CO and NM border, outside of a few possible flurries. With the surface ridge in place, will see most places across the plains fall well into the teens. Higher cloud cover over the far southeast plains should keep these locations slightly warmer. Similar temps expected Wednesday and given the strengthening westerly winds, may be slightly warmer. Increasing cloud cover and chances for snow very late in the afternoon/period, though not really expected to increase until the evening. .LONG TERM...(Wednesday night through Tuesday) Issued at 309 PM MST Tue Feb 7 2023 Key messages: 1) Snow will be possible over portions of southeast Colorado from Wednesday night through Thursday. There could be some locally heavier snow showers, and even a few snow squalls possible. 2) Very strong winds will be likely on during the day on Thursday, with some gusts in excess of 60 mph possible over the eastern plains during the afternoon. 3) A cold front will be moving in Wednesday evening with much colder temperatures for highs on Thursday. Along with the winds will be some low wind chill readings in the single digits or even less than 0F for areas of the plains tomorrow evening. 4) Temperatures will rebound quickly from Friday through Saturday, with readings well above the seasonal average for most locations for highs on Saturday. 5) There will be a gradual cooldown beginning Sunday through early next week, with a chance of snow on Monday and Tuesday, mainly for the southern mountains and plains. Detailed discussion: Wednesday night through Thursday... A deepening major shortwave trough over Montana will move down over the region through Thursday. There will be increasing clouds during the evening on Wednesday, and some of the model guidance is starting precipitation over Central Mountains and the Rampart Range/Palmer Divide area as early as 9 PM. This system has a good amount of dynamic forcing associated with it, however it lacks moisture. Therefore, it could provide some good bursts of locally heavy snowfall for some areas, while completely missing others. When analyzing the CAMs (convective allowing models), the HRRR appears to be the driest, especially over the plains. The ARW has only a concentrated area of heavier QPF over Crowley and Kiowa counties around midnight. Some of the other guidance suggests better amounts for the plains, especially the NAM 4km Nest, which also reflects a similar QPF to the ARW, with a micro-low embedded within the surge of colder air over northeastern Otero County around 10 PM, providing the extra lift needed for a heavier swath of snow around the US-50 in Bent and Prowers counties and northward. This heavier cluster then proceeds to move over the southeastern plains through the early morning on Thursday if the NAMNst verifies. Given the convective nature of this with higher instability, there could be snow squalls with this initial wave, even over the mountains. In terms of the deterministic models, the GFS-20 does the best with QPF over the Palmer Divide area, and the NAM12 also alludes to higher amounts over the plains. The Canadian and ECMWF are more sparse in terms of QPF over the plains, and keep the higher amounts limited to more of the southern I-25 corridor where there is more of an upsloping wind component to allow for better lift. The GFS does favor higher QPF over the southern I-25 corridor and extending back into the lower Arkansas River Valley between midnight and 5 AM on Thursday morning. The models are in fairly good agreement with better QPF sticking around over the southern I-25 corridor and Raton Mesa area going into the early afternoon hours on Thursday. There will also be some lingering snow showers continuing into the afternoon hours over the central mountains, and then the snow will continue to taper off and should be completely ended by the evening hours with clearing taking place throughout the night. The timing of the cold front also is relatively similar with all of the model guidance, with winds switching to a northeasterly direction over the plains at around 5 PM with an initial push of colder air being the earliest with the HRRR. There is going to be a stronger surge of colder air moving in later around midnight, which will cause the increase in the northerly winds as the gradient tightens from the deepening low to downstream over the Great Lakes Region and the high builds in over the western states, along with stronger winds moving in at the 700 mb level. Due to this, these strong winds will help to draw in much colder air advection over the CWA, with high temperatures being anywhere from 10 to 15 below the seasonal average on Thursday. These blustery winds will also create wind chill values mainly in the teens over much of the plains during the day and then dropping into the single digits, or perhaps even below 0F, for several locations by later in the evening. There will also be much stronger winds over Kiowa, Bent, Prowers, and Baca Counties which will likely reach High Wind Warning criteria from around sunrise to the late afternoon hours. There could also be some locations that potentially reach HWW criteria in eastern El Paso County, as well as Crowley and Otero Counties, but more than likely for a shorter duration. These winds do look to weaken by around 5 PM and gradually decline going into the late evening hours. Friday through Sunday... Winds will continue to weaken by early Friday morning as the trough proceeds to move further north and allows for a ridge to move over the region. This will allow for downsloping westerly winds to provide a nice warmup back to around the seasonal average for most, especially the plains, on Friday. Temperatures will even further warm up significantly on Saturday as the strengthening and slight positively tilted ridge moves over Colorado. Expect temperatures to be well above the seasonal average for the plains, and even slightly above average for the higher terrain. Temperatures will cool back down on Sunday near the seasonal average as the ridge breaks down, and another major shortwave trough begins to advance closer towards the region, with extensive mid and high cloud coverage within the baroclinic leaf moving overhead. Monday through Tuesday... Ensembles and deterministic models alike are generally displaying a longwave trough moving in over the region early next week with an U/L cut-off low over the southwestern CONUS, however, there is some disagreement with the actual place of the trough will be between the GFS and the ECMWF. The GFS puts the progression of the trough further ahead than the ECMWF, and the Canadian is much more similar To this. The location of the cut-off low is very close in agreement between the GFS and Canadian. The ECMWF not only has the cut-off located much further east, but it also keeps the trough further back over Utah at the same time the other models has it over Colorado on Monday afternoon, and also has the axis less positively tilted. If the ECMWF verifies, it will be mainly dry over Colorado on Monday, whereas if the GFS and Canadian resolve this better, there could be some snow over the higher elevations. On Tuesday, the cut-off low will progress northeastward and could provide a chance of precip for southeast Colorado, especially over the southern half of the CWA. This is where the GFS and Canadian diverge as far as the progression of the cut-off low, where the GFS has it moving far south and not providing any precip over southeast Colorado on Tuesday whatsoever. -Stewey && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 309 PM MST Tue Feb 7 2023 VFR conditions and dry weather are expected to persist this period. Winds will generally be light and diurnally driven, though do anticipate increasing northerly winds at ALS very late with COS possibly becoming more variable with an approaching boundary. && .PUB WATCHES/WARNINGS/ADVISORIES... High Wind Watch from late Wednesday night through Thursday afternoon for COZ095>099. && $$ SHORT TERM...RODRIGUEZ LONG TERM...STEWARD AVIATION...RODRIGUEZ
Area Forecast Discussion
National Weather Service Sacramento CA
148 PM PST Tue Feb 7 2023 .SYNOPSIS... Mostly dry weather this week with chilly nights, near to slightly above normal high temperatures, and areas of Valley fog. Light precipitation possible Friday into Saturday, and again early next week. Breezy northerly winds later this weekend into Monday. && .Discussion... Latest GOES-West visible satellite imagery shows a band of clouds moving across interior northern California early this afternoon. These clouds are associated with a shortwave trough that is passing over the Pacific Northwest today. The upper level ridging will flatten a little bit today as this shortwave passes to our north, but the ridging will build back in on Wednesday and Thursday. This band of clouds is expected to move out of the area later this afternoon. Some clearing skies and light winds will allow for the potential for fog development Wednesday morning. HREF probabilities show about 50 to 80 percent probability for less than a half mile visibility from Oroville southward. The HRRR is also highlighting dense fog from about the Sacramento area southward. With the increasing confidence in the return of dense fog, a Dense Fog Advisory has been issued from 2 AM to 10 AM PST Wednesday for portions of the southern Sacramento Valley, Carquinez Straight and Delta, and northern San Joaquin Valley. Motorists should drive slow and use low- beam headlights when fog is encountered. Relatively quiet weather is expected Wednesday and Thursday, with some chilly overnight temperatures, near to slightly above normal daytime temperatures, and generally light winds. Daytime high temperatures in the Valley are expected to be in the 60s both days. An upper level trough will approach the area on Friday, bringing along chances for light precipitation Friday and Saturday. At this point, minimal impacts are expected, as this system does not have much moisture associated with it. The National Blend of Models (NBM) has about a 10 to 25 percent probability of observing a tenth of an inch of precipitation or greater, mainly confined to the higher elevations of the foothills and mountains. Snow probabilities range from 25 to 50 percent chance of observing greater than an inch of snow in the mountains. && .EXTENDED DISCUSSION (Saturday THROUGH Tuesday)... Ensemble guidance is in agreement for the upper level low to push southward across California over the weekend and into early next week. Minimal impacts are expected with this trough besides some light precipitation and breezy north to east winds. Some lingering showers will be possible on Saturday as the weak weather system moves through the area. Dry weather returns Sunday and into Monday as ridging builds back in behind it. The Extreme Forecast Index (EFI) highlights increased wind speeds and wind gusts over the Sacramento Valley and Sierra Nevada later this weekend and into Monday behind the passage of this system. An additional shortwave trough early next week will bring chances for light precipitation late Monday into Tuesday. && .AVIATION... Light and variable winds expected across the region through at least Wednesday. Periods of SCT to BKN mid to high clouds aoa 12 Kft through 03-05Z Wednesday, then a brief period of mostly clear skies tonight. MVFR to LIFR conditions possible for TAF sites from the Sacramento Area to KMOD where fog development is likely between 11Z-17Z Wednesday. //Peters && .STO WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory from 2 AM to 10 AM PST Wednesday for Carquinez Strait and Delta-Northern San Joaquin Valley-Southern Sacramento Valley. && $$