Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/03/22

Area Forecast Discussion
National Weather Service Bismarck ND
956 PM CDT Mon May 2 2022 .UPDATE... Issued at 953 PM CDT Mon May 2 2022 Recent trends in the GOES-16 Nighttime Microphysics RGB show gradual westward expansion of stratus, as previously discussed. With this update we increased cloud cover in sky grids through Tuesday morning. Fog was also trimmed to keep most coverage west of stratus, in western North Dakota. There may need to be an adjustment in coverage of fog depending on how it develops tonight, but will leave that for upcoming updates. UPDATE Issued at 634 PM CDT Mon May 2 2022 23Z satellite picture remains consistent to this afternoon, where stratus was placed across eastern North Dakota with more broken up mid-level clouds in the southwest. The question tonight will be the westward progression of stratus as RAP and NAM forecast soundings show saturation in the low levels overnight, though less so towards KDIK-KXWA. With southeast winds it looks likely that stratus should expand overnight given relatively higher dew points southeast and the upslope component to the flow. && .SHORT TERM...(This evening through Tuesday) Issued at 130 PM CDT Mon May 2 2022 Current surface analysis places lows over eastern Ontario and over the southern plains, with ridging over the northern plains. Upper level analysis shows a variety of compact lows, with one over western Ontario, one over the central plains, and a deeper one affiliated with a broader trough over the Pacific Northwest. Over our area, westerly flow continues with a weak ridge to the west. For us, rather quiet weather continues, though a broad area of low cloud cover continues to stretch from the Turtle Mountains into the James River Valley and points eastward with light flow and ample low level moisture. For the rest of this afternoon into this evening, quiet weather will continue. Low clouds over the east may end up spreading towards the west tonight with the low level easterly flow. To the west of the cloud cover where skies will be clear, some patchy fog may develop late tonight. On Tuesday, quiet weather continues with weak ridging ahead of the aforementioned Pacific Northwest low which will meander over the Great Salt Lake area through the day, into the central Rockies overnight. .LONG TERM...(Wednesday through Monday) Issued at 130 PM CDT Mon May 2 2022 Aforementioned compact low works its way over the central plains Wednesday into Thursday. Precipitation should stay south of our area as this system continues on its way, but we may see an increase in cloud cover, primarily over southern areas. Temperatures will be on a gradual warming trend, which will continue through Friday. This weekend a deep Pacific trough will work its way into the western CONUS, bringing increasing precipitation chances this weekend into the start of the upcoming work week. In addition, temperatures will start to cool, but not greatly. There is still much question as to the location and timing of some key features, but the overall message is that a wetter pattern is probably on tap. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 953 PM CDT Mon May 2 2022 MVFR to IF stratus continues over eastern North Dakota, including KJMS tonight. There good indications that this stratus will spread west overnight, likely impacting KBIS-KMOT. KXWA-KDIK somewhat questionable if stratus makes it that far west, however if it doesn`t there will be the possibility of fog development and visibility reductions. Occurrence of this will likely hold off until 06Z or after. Conditions should improve in the west and central through the morning, and possibly at KJMS by Tuesday evening. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AE SHORT TERM...JJS LONG TERM...JJS AVIATION...AE
National Weather Service Sioux Falls SD
1037 PM CDT Mon May 2 2022 .SHORT TERM...(This Evening through Tuesday) Issued at 256 PM CDT Mon May 2 2022 Expansive rain shield across much of NE into southwest IA associated with a well-defined surface low across west-central KS is really struggling to move north of the MO River this afternoon. Latest RAP soundings show a substantial dry wedge above 3000 ft agl and this is not likely to moisten much over the ensuing hours. Best chance for measurable rain is now for areas along and south of line from Vermillion to Storm Lake, but even here amounts are not likely to exceed a half inch. Farther north, expect little to no accumulation with communities along the I-90 corridor now expected to remain dry through the evening. Temperatures tonight will be highly dependent on cloud cover. If some clearing can occur late for areas west of the James River, sub-freezing temperatures are possible. Otherwise, cloudy areas will generally dip into the mid to upper 30s. Surface high pressure drifts across the forecast area on Tuesday, resulting in gradually clearing skies, light wind, and warming temperatures. Afternoon highs are expected to climb into the mid to upper 50s. .LONG TERM...(Tuesday Night through Monday) Issued at 256 PM CDT Mon May 2 2022 Clouds and rain chances return Wednesday and Thursday as a slowly meandering 500 hPa closed low moves across the Central Plains. Areas south of I-90 stand the best chance of seeing measurable precip with drier conditions to the north. With instability bottled up across the Central/Southern Plains, any precipitation will fall as light rain showers. Not expecting to see much change in daily temperatures with afternoon highs remaining in the 50s. A warming trend commences Friday into the weekend as 500 hPa short-wave ridging builds across the region in advance of a substantial Pacific trough. For the most part, late week looks dry with highs rising into the mid 60s to lower 70s. Saturday night into Sunday, rain/possible thunder chances return as aforementioned Pacific trough moves east. Multiple short-waves within nearly meridional flow are ill-resolved at this point, so will lean on current NBM POPs for the late weekend period, which are in the 50 to 60 percent range. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 1037 PM CDT Mon May 2 2022 Low level stratus remains across majority of the region, though we are starting to see pockets of clearing occurring so will likely continue to see improvements throughout the overnight period. Still have some light rain showers occurring across NW Iowa, but that activity will be moving into central Iowa over the next couple hours. Otherwise, expect light winds to continue into tomorrow, starting off north-northeasterly during the morning turning to east- southeasterly by the afternoon hours. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...Rogers LONG TERM...Rogers AVIATION...APT
Area Forecast Discussion
National Weather Service Lincoln IL
800 PM CDT Mon May 2 2022 .SYNOPSIS... Issued at 310 PM CDT Mon May 2 2022 A rainy night is on tap for central Illinois, as low pressure arrives in central Illinois by late Tuesday morning. This storm system will spread showers and a few thunderstorms northeast across central Illinois this evening, with shower chances continuing into Tuesday. Dry conditions return Tuesday night and Wednesday before the next storm system brings more showers and isolated thunderstorms back into the area overnight Wednesday night through Friday. && .UPDATE... Issued at 800 PM CDT Mon May 2 2022 An area of light rain has been advancing across the forecast area this evening. However, our evening sounding shows plenty of dry air below 700 mb, so much of this has been more along the lines of sprinkles. Regional radar mosaics show a large break in the rain, though some of it in the southeast CWA may be enhanced a bit longer by an MCV moving across southern Illinois. However, a larger area of showers and scattered thunderstorms is located over western Missouri, with the latest HRRR bringing it into west central Illinois closer to midnight. There still looks to be some breaks in the rain toward daybreak into Tuesday morning south of I-72, south of the low track. Recent forecast updates were done for some timing adjustments on rain chances. Temperatures were generally on track, but some tweaks were done to the hourly temperatures on Tuesday due to gridding tool errors caused by the non-diurnal trend across the northwest half of the CWA. && .SHORT TERM...(This evening through Tuesday) ISSUED AT 310 PM CDT Mon May 2 2022 A brief period of high pressure has provided some filtered sunshine and light winds this afternoon. However, a stationary front draped from the Plains across Missouri and southern Illinois will begin to lift north tonight. It`s parent low pressure will track from N Oklahoma this evening across central Illinois on Tuesday. Forecast soundings are pointing toward a relatively rapid saturation of the boundary layer with rain developing late this afternoon in our SW counties. Satellite images already indicate saturation in progress below the cloud-bearing layer. Surface dewpoints are projected to climb from the 40s this afternoon into the mid-upper 50s tonight and into the low to mid 60s Tuesday morning. While that usually ties to increasing instability, the timing of that surge of moisture will be at an unfavorable time for surface based CAPE. However, the models are indicating that low level helicity will be 400-600 m2/s2 tonight in the southern half of our CWA, as a 45-50KT 850mb LLJ noses into IL. Any storms that do develop could have some rotation develop. However, the marginal instability should preclude the development of severe weather from those storms. A dry slot is expected to push across our southern counties Tuesday morning, shutting down precip in that area by early afternoon. Our northern counties could see rain showers linger as the center of the surface low passes directly over that area, along with the upper trough axis. A wide range of high temps are expected, with morning highs in the low 70s south of I-70, while areas near Galesburg/Lacon struggle to climb into the mid 50s. && .LONG TERM...(Tuesday night through Monday) ISSUED AT 310 PM CDT Mon May 2 2022 A break in the rain will occur Tuesday night as NW winds usher in some cooler air. Lows will drop into the low to mid 40s in most areas, with below normal highs on Wednesday. The next long wave trough will arrive late Wednesday night and Thursday, producing another period of widespread rain and scattered storms. The rain on Thursday will be associated with synoptic lift north of the warm front, while Thursday night and Friday precip will come with the passage of the occluded low. The system looks to be an efficient rain producer, with QPF amounts around 1.25 to 1.75 inches Thursday into Friday. The upper trough should shift east of Illinois Saturday, helping bring an end to the rain shortly after sunrise Sat. Depending on the timing of the clearing of clouds, high temps could reach near 70. Forecast highs for now are in the mid 60s Sat. ECMWF and Canadian are advertising a Rex Block setting up for Sunday and Monday, while the GFS keeps the ridge very narrow and not in a blocking pattern. The ensemble spread is relatively high as a result of the spread. However, a robust warming trend is likely early next week, with 80s possible for highs on Monday. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 606 PM CDT Mon May 2 2022 Ceilings expected to steadily decrease, dropping to MVFR from 05-08Z and to IFR before 12Z, as rain moves into the area. A period of thunder is expected overnight and have continued VCTS mentions for about a 3-5 hour period at each site. Once ceilings drop below 1,000 feet, they should largely stay there or perhaps nudge up into low MVFR territory at best. Wind forecast will be tricky, as low pressure tracks directly across central Illinois early Tuesday morning. While gustiness picks up around toward late this evening, it will drop off for a few hours with the low passing overhead, before returning with winds shifting to the north/northwest during the afternoon. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Geelhart SYNOPSIS...Shimon SHORT TERM...Shimon LONG TERM...Shimon AVIATION...Geelhart
Area Forecast Discussion
National Weather Service North Platte NE
719 PM CDT Mon May 2 2022 .SYNOPSIS... Issued at 253 PM CDT Mon May 2 2022 The current storm system is centered over far northwest KS. A large deformation existed to the north of the low across the southeast panhandle and southwest NE into the central Sandhills. A look at area webcams shows light snow continuing across much of these areas, with moderate to heavy snow continuing across western Custer County. Snow accumulations so far are around 2 inches parts of western Custer County, and from 1 to 2 inches portions of the west. Some areas however have not accumulated, including Tryon. With snow and reduced visibility still lingering across the west, will keep the existing Winter Weather Advisory in effect across the western Sandhills until 5 pm MDT. && .SHORT TERM...(This evening through Tuesday night) Issued at 253 PM CDT Mon May 2 2022 The closed upper low will track east northeast this evening to near Omaha by midnight. Chance to likely POPS across the east through early evening, then ending far eastern areas by around midnight CDT. Do not expect much for accumulations this evening, except for a dusting of wet snow possible parts of Custer County. Expecting some clearing overnight across the northwest Sandhills, as the remainder of the area remains cloudy. This will help keep lows up a few degrees overnight, from the upper 20s northwest to the lower 30s southeast. The precipitation received today and support from the 15Z SREF and RAP models indicate that patchy fog is expected across the southwestern half of the area. This is expected from 09Z until 15Z Tuesday. Upper ridging briefly builds in Tuesday with some clearing skies into the afternoon. Highs to mostly range in the mid 50s. The next upper trough and closed low will move into CO and WY Tuesday night, bringing increasing chances for showers across the west. .LONG TERM...(Wednesday through Monday) Issued at 253 PM CDT Mon May 2 2022 The upper trough and closed low will move slowly eastward across Nebraska and Kansas Wednesday and Thursday. This will bring a chance for showers through the period. Temperatures will be cool in the mid 50s Wednesday and the upper 50s to low 60s Thursday. Friday expected to be dry and warmer and the system moves east of the area and weak warm air advection returns. Highs return mainly into the 70s. A broad upper trough will deepen across the western U.S. Saturday thorugh Monday. This will bring a chance for showers each day, with thunderstorms also possible during the afternoon and evening hours. Southwesterly flow aloft will increase. The area is expected to remain in the "warm sector" each day. This is shown more substantially by the 12Z ECMWF than the 12Z GFS. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 719 PM CDT Mon May 2 2022 Lingering precipitation across north central Nebraska will slowly come to an end this evening. In the wake of the departing precipitation, some patchy fog is possible, mainly across southwest Nebraska and the eastern Panhandle. Fog may impact KLBF Tuesday morning with visibility down to 4 miles. Fog will dissipate by mid- morning giving way to partly sunny skies with gradual increasing ceilings through Tuesday afternoon. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Roberg SHORT TERM...Roberg LONG TERM...Roberg AVIATION...Kulik
Area Forecast Discussion
National Weather Service Louisville KY
848 PM EDT Mon May 2 2022 .Forecast Update... Issued at 849 PM EDT Mon May 2 2022 A weakening cluster of showers and storms is moving NE toward our CWA from western TN/KY at this hour. Cloud tops in IR satellite imagery have been steadily warming, and the convection will be running into some much drier air over our CWA. So, given that plus latest HRRR runs showing the activity dissipating across our SW CWA tend to agree with that solution. Previous forecast already had the pops in our SW to cover this, so no changes planned at this time. There is a left mover that had a history of severe hail across western TN that is now moving into Christian county, but it has steadily weakened and isn`t expected to be a threat when it arrives in our CWA. && .Short Term...(This evening through Tuesday) Issued at 340 PM EDT Mon May 2 2022 ...Strong to Severe Storms Possible Tuesday Afternoon and Evening... A beautiful afternoon is in progress - warm, dry, and low humidity. Temperatures have warmed into the mid 70s under increasing cirrus streaming in from the west. Sfc low pressure is rotating into western Oklahoma on the southeastern flank of a compact mid/upper level trough near the CO/KS border. This low pressure system will continue ENE tonight into Tuesday, with the sfc low forecast to track across central MO/IL late tonight and Tuesday morning. A warm front gets pulled northward across the CWA with a 40+ kt southwesterly LLJ arriving after 06z tonight. Expect scattered to numerous showers to move through late tonight through early Tuesday morning, with the highest PoPs/QPF concentrated near and north of the Ohio River. The northern CWA will see stronger forcing for ascent and low-level moisture transport closer to the core of the low-level jet. Isolated rumbles of thunder are also likely, though any storms will remain elevated in nature through Tuesday morning. Warm advection showers are already exiting off to the northeast by 12-14z (mid-morning) Tuesday. A lull in shower activity is then likely into early afternoon, during which time the atmosphere will destabilize ahead of the impinging cold front. HREFv2 and v3 data supports a high likelihood for greater than 1000 J/kg MLCAPE with the greatest instability axis from Bowling Green to Lexington. Deep- layer shear on the order of 30-40 kts will be supportive of strong to severe convection - the more marginal 30 kt values will be across south-central KY. Forecast soundings and hodographs show little directional shear, but fairly impressive 0-1 km speed shear. Multicell storm clusters organized into linear segments look possible along and just ahead of the cold front. A veered wind profile, steep low-level lapse rates, marginal mid- level lapse rates, and some mid-level dry air all point to damaging straight-line winds as the primary threat. There is a low risk for an isolated tornado and marginally severe hail. Timing: The main time frame of concern for severe weather is 2-10 PM EDT. These storms will be initiating overhead, likely near the I-65 corridor. The area with the greatest (relative) chance for severe weather is roughly east of a line from Scottsburg, IN to Bowling Green, KY. Confidence: Agree with SPC`s Slight Risk for severe weather, so any severe weather will remain isolated in nature. Given that definition, confidence in severe weather is low-medium. Confidence in isolated damaging winds is medium. Confidence is low for tornadoes, large hail, and flash flooding. .Long Term...(Tuesday night through Monday) Issued at 320 PM EDT Mon May 2 2022 Synopsis...In the wake of the lifting shortwave trough, a brief period of drier weather is anticipated as mid-level ridge moves overhead and the surface cold front washes out in the lower Tennessee Valley. Thereafter, global model guidance hasn`t changed enough to agree in an unified solution. The GFS output keeps depicting the translation of the upcoming closed low much faster than its CMC/ECMWF counterparts. These differences might prove significant when comparing the expected storm total QPF as the latter favors a greater flooding risk. Besides, there is potential for another round of strong/severe storms during the Thursday-Friday interval. Nonetheless, given the aforementioned model uncertainty, it is still of low confidence. Overall, an slower, more amplified, and detached scenario is preferred for this part of the forecast. Finally, it seems that model differences are reconciled by next week as the GFS catches up with the CMC/ECMWF in portraying an Omega-type blocking pattern as an elongated mid-level ridge extends from the Gulf of Mexico to the Great Lakes and into Canada, flanked by distinct troughing. Wednesday...Although some light showers might manifest in the KY/TN border at sunrise, most of the frontal heavy rain would have already moved further south while subsidence and mid-level dry air prevail. As a result, anticipate a drying trend for the middle of the week along with low/high clouds and light northerly surface winds. Thursday-Saturday...The next system in store for the lower Ohio Valley will be better organized and with more dynamic support. An occluded and vertically stacked surface low could potentially track near or north of the KY state line Friday into Saturday. Initially, a warm front could bring the first elevated chance of rain/storms during Thursday afternoon and evening. CAPE/Shear space parameters could boost the potential of discrete organized convection, so elevated weak supercells cannot be ruled out. The slower model solutions promote a northern storm track which augments the possibility of warm-sector convection over central Kentucky, even though this could happen after losing some diurnally-driven instability. The next chance of storms and heavy rain comes with the actual cold front passage, probably between Thursday night-Friday morning. Aside from any severe weather concerns, it is also reasonable to talk about flood risks, especially if the Tuesday rain episode leaves non-negligible accumulations. Some factors to weigh in are the slow movement of the system which enhances training showers and low one- and three-hourly FFG in the Cumberland and some parts of the Bluegrass regions. Although storm total QPF is not impressive, it did increase since the last package. Also, suspect that global models` spatial resolution might not be adequate to resolve the embedded convective elements that usually support the greatest rain rates. That`s why, CMC QPF (highest guidance) could be the most representative of this period rainfall, which currently depicts 2-3+ inches area-wide. Sunday-Monday... Rain-free weather for this part of the medium range as strong high pressure and elongated upper ridging become established over the central CONUS. After a couple of days registering normal or slightly below-normal temperatures, southeasterly flow will warm up the mercury as highs on Monday might reach the low 80s. && .Aviation...(00Z TAF Issuance) Issued at 753 PM EDT Mon May 2 2022 A low pressure system is expected to move from the eastern Great Plains to the eastern Great Lakes through this TAF period. As this occurs, a warm front will lift NE across our TAF sites tonight, and then a cold front will sweep through by Tuesday evening. TAFs will go valid in a VFR regime with Bkn-Ovc upper sky cover and light E winds. Ceilings will gradually lower overnight, but will stay VFR. Numerous showers with embedded thunder will accompany the warm front later tonight into tomorrow morning, before a brief lull in activity takes hold by late morning into the early afternoon. A second round of showers and storms is then possible ahead of the cold front from afternoon through evening. Surface winds will steadily veer from SE tomorrow morning, to SW by tomorrow afternoon, gusting in the afternoon up around 25 knots. Tried to include best timing for prevailing or tempo showers and storms, and also mentioned a low level wind shear threat mainly at HNB/SDF tonight. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Update...BJS Short Term...EBW Long Term...ALL Aviation...BJS
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
635 PM CDT Mon May 2 2022 .SHORT TERM... (Through Late Tuesday Afternoon) Issued at 246 PM CDT Mon May 2 2022 The primary focus for tonight and Tuesday is severe thunderstorm chances and the possibility of heavy rain across parts of northeast Missouri this evening. Latest deterministic guidance is showing a relative lack of strong instability tonight with less than 500 J/Kg MUCAPE on the GFS and a bit more on the NAM, but generally less than 1000 J/Kg. The RAP has somewhat more, with 1000-1500 J/Kg, and with 40+ kts of deep layer shear, its solution would give us the greatest chance for severe storms. CAMS do show some relatively strong convection tonight, primarily west and southwest of our forecast area, but by the time it gets here it`s weakening. With this in mind, I think the probability for severe storms tonight is low. I wouldn`t be shocked if there was some hail or a localized wind gust in a few storms, but widespread/large hail does not seem very likely. Turning attention to heavy rain, WPC forecast has over an inch across parts of northeast Missouri this evening. GEFS and ECENS situational awareness plots do highlight that area tonight as anomalously high on P-wats, IVT, and QPF, however none of these parameters are maxed out, and our 1 hour FFG guidance values are 1.5 to 2 inches. Given that the ground seems able to absorb the 1-1.25 inch QPF we`re forecasting, will hold off on issuing any hydro headlines at this time. As this first system moves east tonight and Tuesday, it will drag a cold front through the region. Cooler and drier air will move in behind the front which will shut the rain off from west to east through Tuesday morning. There may be some lingering showers over southeast Missouri into the afternoon, but most of the area should be dry by 18Z Tuesday. Carney .LONG TERM... (Tuesday Night through Next Monday) Issued at 246 PM CDT Mon May 2 2022 The next short wave in line will have crossed the Rocky Mountains by Wednesday morning, forcing lee-side cyclogenesis over the Oklahoma Panhandle. Low level flow will turn back to the south and southwest across Missouri and Illinois by Wednesday evening. It should take most if not all of Wednesday to moisten the atmosphere over our area enough for precipitation, but overnight Wednesday night into Thursday morning looks wet. Deterministic guidance shows a 40-50kt low level jet with moderate to strong moisture convergence pushing into eastern Missouri and western Illinois between 06-12Z Thursday, with plenty of QPF, so the likely to categorical PoPs that the NBM builds across the region Wednesday night into Thursday look entirely appropriate. The 02/12Z GFS and ECMWF are now in much better agreement with the speed and strength of the low as it drifts across the Mid Mississippi Valley through the end of the week. The GFS is much slower, and is nearly in lockstep with the ECMWF now. WPC cluster analysis is also showing much less variability on speed and strength with this system on the EOF plots...though there is still some speed difference in the ensemble clusters on day 4 and 5 (Saturday/Sunday). The primary impact of a faster or slower system will be rain chances or lack thereof on Saturday, and cooler/warmer temperatures on Sunday. Regardless, Sunday should be dry and warmer and Monday looks downright balmy as another deep trough digs into the southwest U.S. and south-southwest flow is re-established over the Mid Mississippi Valley. Carney && .AVIATION... (For the 00z TAFs through 00z Tuesday Evening) Issued at 629 PM CDT Mon May 2 2022 The primary concerns during the 00Z TAF cycle will be progressively lowering ceilings, as well as the potential for thunderstorms overnight tonight. While it appears likely that both things will occur and impact most local terminals, confidence is low regarding the timing of each. While precipitation is diminishing temporarily this evening, ceilings have begun to lower at COU/JEF, and this is expected to continue over the next several hours, and also spread eastward to affect additional terminals. IFR ceilings are likely overnight, with very gradual improvement expected tomorrow morning through the afternoon. Showers and scattered thunderstorms are expected to move into the region late this evening through the early overnight hours. Confidence is highest that storms will impact central Missouri terminals (COU/JEF), but there is at least a reasonable potential for thunderstorms to impact all areas. Hail and gusty winds will be possible with the strongest storms. Precipitation should largely cease very late tonight aside from a few light showers.. BRC && .PRELIMINARY POINT TEMPS/POPS... Saint Louis 60 63 50 68 / 90 40 5 10 Quincy 54 58 45 62 / 90 50 0 10 Columbia 52 56 49 66 / 90 20 0 30 Jefferson City 53 57 49 66 / 90 20 0 30 Salem 62 68 49 68 / 90 30 5 5 Farmington 60 66 49 69 / 90 30 10 20 && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1058 PM CDT Mon May 2 2022 .UPDATED for 06Z Aviation Discussion... Issued at 1058 PM CDT Mon May 2 2022 && .DISCUSSION...(This evening through Monday) Issued at 237 PM CDT Mon May 2 2022 KEY MESSAGES: - Temperatures near to even a little above normal expected to return this weekend. - Weather pattern looks fairly quiet this week, but looks to turn active again next week. Tonight through Tuesday... Strong shortwave on water vapor imagery spinning across CO and into KS will be our primary weather driver during this period. It will remain to our south, but tonight we will see an area of rain build north across IA. The question remains with how far north precipitation makes it. Trend from the 12z guidance was to keep the northern edge of the precip shield a bit farther south, so have basically confined precipitation chances tonight to the I-90 corridor. We may see some clearing of the low clouds into central MN tonight, but those clouds will just be replaced by mid/upper clouds from the system to the south. Tuesday, a surface ridge axis will move into the area and although we are advertising mostly sunny skies by the afternoon, forecast soundings from the RAP do cause a little concern as they show the stratus deck remaining in place through much of the day. At the very least we`ll start the day with the stratus deck still overhead, with the current expectations being that it will clear out through the morning, leaving us with mainly sunny skies by the afternoon. The sun will also allow us to warm up, but the CAA on the north winds will keep highs in the 50s. Wednesday through Friday... Mid to late week, we will see split flow develop. The northern stream will head north into Canada, with the southern stream sending another slow moving closed h5 low across the central Plains and into the Ohio Valley. This will result in another multi-day severe weather episode to our south, with the main impact for us being the threat of some light rain once again on Thursday sneaking up into southern MN. There wasn`t a huge change to this precip chance with this update outside of a small reduction to PoPs on Thursday. With us being stuck between the northern and southern streams, we`ll at least see temperatures continue to moderate back closer to seasonal normals. The weekend into early next week... The big story here is a significant pattern change to what we have seen much of this spring. GEFS/EPS mean h5 forecasts show a strong ridge building over Quebec this weekend, with a trough digging into the Rockies. This will set us up into southwest flow. At the very least, this will lead to our first prolonged stretch of what one might call spring-like weather of the season. Where uncertainty reigns is with how quickly we start seeing energy move out of the western trough and into the upper MS Valley. The GFS continues to be the most aggressive with bringing energy from the western trough in on Sunday, though even it has slowed down closer to the ECMWF, which hangs most of that energy back until next week. Given the strength of the ridge and its possible development into a rex block over eastern NOAM, the slower solution is more likely at this point. With that said, given current model spread, stayed with the NBM forecast, which didn`t change much from the previous forecast with chance PoPs spreading across the area on Sunday that continue into next week. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 1058 PM CDT Mon May 2 2022 VFR conditions continue to become more widespread this evening, so have kept this trend going in the TAFS and removed most of the MVFR ceilings except at KMKT and KEAU where they could see a bit more low level moisture from the system to the southeast. Otherwise expect light northeast winds becoming a bit more easterly Tuesday night. KMSP... VFR conditions should continue throughout the TAF period. There is a chance for some MVFR at times, but overall the clouds have trended a bit higher the last few model runs. Winds will be northeast, and eventually easterly Tuesday night. /OUTLOOK FOR KMSP/ Wed...VFR. Wind SE at 5-10 kts. Thu...VFR. Wind ESE at 5-10 kts. Fri...VFR. Wind SE at 10-15 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...MPG AVIATION...JRB
National Weather Service Morristown TN
1009 PM EDT Mon May 2 2022 .UPDATE... EVENING UPDATE. && .DISCUSSION... The convection south and west has been moving northeast and weakening/dissipating so far. The hi res models have generally backed off on overnight convection. Cannot rule out thunder but think the chance is rather low given the very limited convective energy and forcing. Will make a few tweaks to the low PoPs and remove thunder overnight. Will also make some minor adjustments to temps and dew points with this update. && .AVIATION... 00Z TAF DISCUSSION. Will carry VCTS for a few hours CHA as convection is not too far off to the south and southwest, but probability of TSRA occurring at the airport still looks low this evening. Cannot rule out a shower or even thunder later tonight into early Tuesday at any site but again it looks too unlikely to impact the airports to include for now. However, by afternoon will include a prob30 group for thunder at TRI. Outside of any thunderstorm, VFR conditions are expected all sites for the period. Winds will be light overnight then become gusty from the southwest Tuesday. && .PREV DISCUSSION... /ISSUED 325 PM EDT Mon May 2 2022/ SHORT TERM...(Tonight Through Tomorrow)... Key Messages: 1. How much if any precip do we see overnight? 2. Breezy afternoon winds Tomorrow with gusts up to about 25 mph areawide. Discussion: This afternoon, visible satellite imagery shows a CU field just south of the TN state line down into GA/AL. This is the current location of the warm front associated with an area of low pressure across the central Great Plains. A much drier airmass is currently across our area with dewpoints only in the upper 40s to low 50s. Tonight, this warm front will lift northeast through our forecast area, reaching northeast TN by tomorrow morning. Our airmass becomes more saturated as the front brings higher PWs in from the southwest. As the front lifts through, we could see a few isolated showers and storms. However, models are having a really hard time with how much if any precip we actually see overnight. A quick look through the CAMs confirms this. Currently have slight chance POPs in through the night, timed around the frontal progression. If the forecast busts, I think it will be toward the wet side as the HRRR shows quite a bit of coverage overnight. Our best chance at showers and storms will be from late tomorrow morning through afternoon up across northeast TN and southwest VA. These areas will be closest to the warm frontal boundary. Currently have chance POPs in for these locations. Believe that most other areas will be dry due to being firmly within the warm sector with little forcing. There is also a slight chance POP along the Cumberland Plateau and east TN mountains. While not expecting severe storms, any thunderstorm(s) that develop tomorrow could produce small hail due to steep lapse rates and gusty winds due dry air at the surface up through 850 mb. Also, southwest flow around 30 kts at 850mb will be in place through the day tomorrow. This is due to the pressure gradient tightening ahead of an incoming cold front to the west and high pressure to our east. Soundings profiles show a well mixed boundary layer so expect gusty winds during the afternoon hours for all areas up to 25 mph. SR LONG TERM...(Tuesday Night through Monday)... Key Messages: 1. Multiple rounds of showers and thunderstorms into the weekend, with best coverage currently looking to be Wednesday and Friday. 2. Warm temperatures will continue through Thursday, with relatively cooler conditions Friday through Sunday. Discussion: This long term period will begin Tuesday night as surface low pressure advances across the Great Lakes region. Much of the southern and central Appalachian region will be well within the warm sector of a warm front lifting to the northeast while a cold front approaches from the west/northwest. This cold front will continue to be the focus for scattered showers and thunderstorms into Wednesday evening. There will be some surface instability present, however, the lack of upper level support will inhibit any strong/severe storms. In fact, it looks as though weak convergence aloft will be working against the frontal forcing and instability. Additionally, high pressure anchored offshore of the Carolinas will lead to the surface front weakening as it transitions across the region. This can be seen by the fact that no significant CAA sets up post FROPA, resulting in relatively cooler temps that still remain a few degrees above seasonal normal Wednesday. For Thursday, there still remains some uncertainty in timing among long term guidance. Another system will be progressing across the central Plains towards the Great Lakes with an initial warm front advancing across the region, followed by another surface cold front. The ECMWF suggest slightly stronger high pressure to the northeast resulting in Thursday remaining dry, whereas, the GFS does have some PoPs around. Stuck fairly close with NBM given these discrepancies. Either way, the best coverage of showers and storms will be Friday with the approaching cold front. The closed upper low will slowly encroach on the eastern coastline heading through the weekend. This will result in some chance/slight chance PoPs for the end of the weekend. In regards to temperatures, warm conditions will linger through Thursday. Conditions will begin to cool Friday due to the cold front and associated precip. KS && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 64 86 65 84 61 / 20 20 40 50 10 Knoxville McGhee Tyson Airport, TN 61 86 64 80 58 / 20 20 50 40 0 Oak Ridge, TN 60 86 62 80 57 / 20 20 60 40 10 Tri Cities Airport, TN 52 84 62 77 55 / 10 50 60 50 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$
Area Forecast Discussion
National Weather Service Spokane WA
403 PM PDT Mon May 2 2022 .SYNOPSIS... Showers and locally breezy winds will gradually decrease this evening as a weather system pulls away from the region. Warmer and drier weather is forecast for Tuesday and Wednesday. A much cooler and wetter pattern is likely Thursday through the weekend. && .DISCUSSION... Tonight through Tuesday Night: A large closed low over Central OR will continue to drop southeast...reaching southern Idaho tonight. A band of rain on the northeast side of this low stretches from the Blue Mountains up into the Wenatchee area but this will weaken and dissipate as the low drops south of the area. Meanwhile ahead of this band of rain a boundary of cooler southwest winds from the rain cooled air has been pushing north and east. As of 1 pm there was a sharp contrast in temperatures with some locations receiving rain such as Wenatchee and Pullman in the 40s while areas further north like Omak and Sandpoint were in the 60s. RAP analysis shows 400-700 J/KG of surface based CAPE from the Camas Prairie up into the Central Panhandle Mountains. Isolated thunderstorms have already developed over far NE Oregon with additional shower development in the Clearwaters. This combined with some forcing with the rain cooled boundary should provide a trigger for additional isolated thunderstorm development into the early evening. The main thunderstorm threat is expected east of Lewiston and Coeur d`Alene. Tonight southwest winds will advect an abundance of boundary layer moisture from SE Washington up towards the Spokane/Coeur d`Alene areas and northern valleys. This will result in increasing stratus and patchy fog tonight into Tuesday morning. The stratus will lift and become a stratocumulus deck for Tuesday afternoon due to daytime heating as a short wave ridge moves over the area. Afternoon sun breaks will allow for near seasonal high temperatures on Tuesday in the upper 50s and 60s. JW Wednesday: Most of the Inland Northwest will experience the warmest day of the spring so far on Wednesday. Afternoon temps will top out in the upper 60s to low 70s. That sounds quite warm after such a chilly April, but compared to average, Wednesday will only be about 5 degrees above normal. Thursday through Saturday: Spring is typically the season for showery and breezy conditions associated with the passage of cold upper lows. The series of storms depicted by the models Thursday through Saturday are wetter than we often see this time of year with a deeper plume of subtropical moisture. Integrated Water Vapor Transport (IVT) values directed into Oregon and southern Washington are sufficient to qualify as a weak atmospheric river Thursday into Friday so we are looking for unusually wet conditions along with periods of wind. *Precipitation amounts: Three-day precipitation totals (Thu, Fri, Sat) are expected to be in the 1 to 2 inch range for the Cascades with up to an inch and a half for the mountainous portions of the Idaho Panhandle. Climate anomaly tools highlight this as being quite unusual for this time of the year. The good news is our base flows in our creeks and rivers aren`t particularly high prior to the arrival of rain. Melting snow will contribute to runoff, but a trend toward cooler temperatures by the weekend will limit some of this runoff by Saturday and Sunday. We will be monitoring creeks and small streams, but at this time our rivers do not appear to show rises to action or flood stage. Some of us may be tired of the rain, but moisture will continue to benefit our dryland farm country of the Columbia Basin and Palouse. *Mountain Snow: Snow levels through Friday should be high enough over the Idaho Panhandle to yield rain for our passes including Lookout Pass. Saturday night will be worth watching however as snow levels drop with the arrival of chilly air. For the Cascades, snow levels may be low enough at times Thursday night, Friday night, and Saturday night for accumulations at Stevens Pass. *Windy Weather: ECMWF guidance forecasts a high probability of west winds gusting 30 to 35 mph Thursday, Friday and Saturday. At this time, our typically windy areas including the Columbia Basin, Palouse, and West Plains look to be the windiest during this three day period of potentially windy weather. *Chilly Temperatures: Temperatures will trend down each day from Thursday to Saturday. By Saturday night, overnight lows in the 30s will be a good bet across most of the Inland Northwest. We may be looking at frost for a good portion of the region by Sunday morning. Sunday and Monday: Mothers Day will be chilly and breezy. Much of the Inland Northwest will experience high temperatures in the 50s which is about ten degrees below average. Monday should trend drier as trough responsible for our active weather late this week digs into the southwestern US. Frost will be possible once again Monday morning with afternoon readings in the mid 50s to low 60s. /GKoch && .AVIATION... 00Z TAFs: Rain cooled air has moistened the boundary layer over Eastern Washington and southwest upslope boundary layer winds will result in increasing MVFR stratus and local IFR conditions into Tuesday morning across the eastern third of WA/N Idaho impacting KGEG/KSFF/KCOE/KPUW. Showers associated with the low pressure system around Wenatchee, Pullman, and Lewiston will come to an end later this evening as the low pressure system pulls away from the area. There also remains a slight chance of thunderstorms through 03z mainly east of Coeur d`Alene and Lewiston. The stratus will lift into a stratocumulus deck for Tuesday afternoon. For KMWH/KEAT downslope westerly winds in the boundary layer should keep conditions VFR through the period. JW && .PRELIMINARY POINT TEMPS/POPS... Spokane 41 63 41 68 48 62 / 20 0 0 0 10 40 Coeur d`Alene 41 61 42 67 47 59 / 20 0 0 0 20 60 Pullman 41 57 39 67 47 59 / 30 10 0 0 0 50 Lewiston 46 65 44 74 53 67 / 70 0 0 0 0 60 Colville 39 68 42 68 46 63 / 0 0 0 0 10 60 Sandpoint 41 62 42 64 46 57 / 10 0 0 0 20 70 Kellogg 43 57 42 66 48 57 / 50 0 0 0 20 70 Moses Lake 40 69 42 71 50 67 / 20 0 0 0 0 20 Wenatchee 44 67 45 70 51 64 / 20 0 0 0 10 30 Omak 44 70 47 70 50 67 / 10 0 0 0 10 40 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
Area Forecast Discussion
National Weather Service Topeka KS
542 PM CDT Mon May 2 2022 ...AVIATION UPDATE... .DISCUSSION... Issued at 255 PM CDT Mon May 2 2022 Key Points: - Increasing coverage of showers and thunderstorms late this afternoon through evening, a few severe possible south of I-70 - Dry Tuesday, then another round of rain and storms Wednesday through Thursday As of 19Z this afternoon, shortwave trough is propagating out of CO and into western KS with VWP data showing a mid-level speed max rounding the base of the trough. The sfc low is centered over western OK near the TX panhandle, with the dryline near the TX/OK border. The warm front has been slow to move northward and remains draped over northeastern OK. Another sfc boundary extends out of the center of the low through central KS across our far southern counties, which has been pretty stationary throughout the day. Cloud cover has kept our area mostly stable so far with scattered showers area-wide and isolated thunderstorms in north central KS where we have about 500 J/kg of MUCAPE and steeper mid-level lapse rates, per SPC mesoanalysis. Between the cloud cover and slow northward movement of the warm front, have knocked afternoon highs down to the 50s across most of the area. Also am less excited about the potential for severe weather this afternoon and evening. Guidance keeps enough MUCAPE (500-1000 J/kg) mainly south of I-70 with enough effective bulk shear (50+ kt) to support elevated storms with a hail threat. For this reason, still cannot rule out a few severe storms with the strongest updrafts, but think the warm front looks to be too far south for tornadoes to be a concern for us at this point. Most CAMs have the activity out of our area into MO by around midnight aside from a few lingering showers possible. Low-amplitude ridging will be overhead for Tuesday, though CAA and cloud cover should keep conditions fairly cool. Highs are forecast near 60, but could remain cooler still with clouds overhead. The next mid-level low will impact the area Wednesday through early Friday as it slowly moves from the Rockies across the Central Plains. There is some slight model variation in where exactly it tracks, but at this time there remains a possibility for a few severe storms in southern parts of the area on Wednesday as well. Pwat both tonight and Wednesday looks to reach around 1.35", which is above the 90th percentile from sounding climatology, so heavy downpours within thunderstorms are possible. Flooding could become a concern for locations that see repeated convection Wednesday through Thursday, especially with east central KS seeing this activity tonight as well. Any wrap-around showers should move out Friday morning as the system moves east, with ridging and southwest flow bringing warming temperatures back to the 70s and 80s for the weekend along with a return to dry weather. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday) Issued at 542 PM CDT Mon May 2 2022 The terminals are likely to remain north and west of the surface low tonight. This should keep the low clouds in place with TSRA remaining elevated. Some of the models try to clear things out by the afternoon, but given the pattern with high pressure building in and a north wind keeping the boundary layer cool think the RAP and GLAMP keeping MVFR CIGS in through 00Z is the more likely solution. CAMs seem to have a decent handle on the convection so will try to be a little more precise with timing precip. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...Picha AVIATION...Wolters