Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/26/19

Area Forecast Discussion
National Weather Service Cleveland OH
1011 PM EDT Sat May 25 2019 .SYNOPSIS... A cold front will slowly sag south across the area late tonight, pushing just south of the area Sunday afternoon. The front will remain between the southern Great Lakes and Ohio valley through Monday before lifting north through the area Monday night into Tuesday, remaining north of the area through midweek. An unsettled weather pattern will remain over the region much of next week. && .NEAR TERM /THROUGH SUNDAY NIGHT/... Little change with this mid evening update. Will have quiet conditions through the early morning hours. Will be watching convection upstream reach western OH by morning. Expecting some showers/thunderstorms to work across the area in the morning and early afternoon with a second round confined more to the southern counties possible for late afternoon/evening. Previous discussion follows. The unofficial start to Summer has brought record heat and severe storms this holiday weekend. Afternoon temperatures managed to reach the upper 80s and lower 90s. We were able to mix out very well with some slightly drier dewpoints working down to the surface. CAPE values have reached between 2000-3000 J/KG, downdraft CAPE values have reached up to 1500 J/KG, Bulk shear values are about 45 to 50 knots. There is also a MCV moving out of Indiana into Ohio this afternoon which all points to an active afternoon with a broken line of severe convection developing and moving eastward. Storm motions will be fast given the mid level flow. The main threats for these storms will be damaging wind gusts of 70 mph and large hail up to ping pong size possible. The latest runs of the HRRR and 4KM NAM Nest have finally came into some decent agreement with the timing and placement of the storm potential through the early evening. Most of the severe storms should be out of our local CWA by 8 pm this evening. A cool front will sag southward into the area by Sunday morning. Another ripple of energy and disturbance will move along in the westerlies early Sunday morning and may interact with the front. Guidance does show additional storms, some strong, may be impacting western Ohio by 9 am Sunday and moving into central Ohio by late morning and midday. Some of these storms may become severe and there is a marginal to slight risk for severe weather across portions of central Ohio. Damaging winds and hail will be again the main threat. Temperatures will be cooler north of the southward front. The front will move through the entire area by Sunday evening with slight drier and cooler weather moving in temporarily. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... Frontal boundary will dip south of the area on Monday allowing for slightly cooler temperatures especially near the lakeshore with northerly flow. The frontal boundary will return north Monday increasing the chances for showers and thunderstorms mainly in the evening. Rain chances come down to only a slight chance for Tuesday due to residual moisture over the area, however dynamics will be insufficient for much coverage. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... Conditions become more favorable for convection on Wednesday as a shortwave trough advances into the Great Lakes region from the plains. This feature has a slow eastward progression and will support a SW flow and moisture stream from the gulf with dew points in the mid 60s and highs in the 80s. The best upper level dynamics are displaced to the northwest, however there will be some enhanced divergence aloft. The trough will weaken and Thursday and swing east of the area Friday with cooler and drier conditions expected late week. && .AVIATION /00Z Sunday THROUGH Thursday/... This round of showers/thunderstorms have passed the terminals as of 00Z/Sunday. VFR conditions in their wake for the remainder of the evening. A cold front will be sinking southward early Sunday morning. Early day showers/thunderstorms will be possible, with the best coverage/second round during the peak heating of the day across southern terminals. CAK/MFD/FDY will include VCTS for those chances. MVFR ceilings possible as we initially generate cumulus later Sunday morning. Non-VFR within any convection that develops too. Winds will be southwest tonight, but veer to the north across the far northern terminals after about 18Z and through 00Z Monday far south. OUTLOOK...Non-VFR possible for periods of time through Thursday, primarily centered around rounds of convection. && .MARINE... Several pieces of low pressure will impact the region today through Tuesday night with a frontal boundary lifting north and south of the lake multiple days. Southwest winds of 10-20 knots on the lake this afternoon will lead to choppy conditions and 2 to 4 foot waves on the east end for a few hours this evening. Otherwise a weak cold front will settle south of the lake early Sunday morning with high. pressure building in behind and bringing generally light wind conditions for Sunday. Easterly winds develop on Monday ahead of a warm front that will lift north across the lake Monday night. This will lead to a brief period of elevated water levels across the western basin of the lake. However speeds may not be high enough to cause anything more than minor flooding issues with the extremely high water levels. Southwest winds increase Tuesday into Wednesday and a Small Craft Advisory may be needed for portions of Lake Erie on Wednesday. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Griffin/Oudeman NEAR TERM...Griffin SHORT TERM...Jamison LONG TERM...Jamison AVIATION...Oudeman MARINE...KEC
Area Forecast Discussion
National Weather Service Des Moines IA
609 PM CDT Sat May 25 2019 .DISCUSSION.../Tonight through Saturday/ Issued at 328 PM CDT Sat May 25 2019 Vigorous holiday weekend into the middle part of next week. Generally west turning southwest flow aloft during this time with several shortwaves tracking across the region before the large upper level system moves through by Tuesday night into Wednesday. Utilized a blend of the HREF, HRRR, and RAP tonight into Sunday and then a mix of the GFS/ECMWF. Tonight through Sunday...instability continues to build over southern Iowa as the boundary drapes across central Iowa from west to east. Dewpoints are in the middle to upper 60s south of the boundary with good moisture transport into southern Iowa and precipitable water values range from 1.0 to 1.5 inches. The pwats are well within the 90th percentile for climatology on May 25th. Corfidi vectors are fairly close in line with the storm movement and thus training storms are possible tonight into early Sunday morning. Soil moisture content is high and rainfall rates tonight should be intense at times and so confident to keep the Flash Flood Watch in effect tonight into early Sunday morning. Much of the precip looks to confined to the southeast by 10-12z Sunday and out of the forecast area by 13-14z. The severe threat tonight remains limited due to the lack of significant low-level shear and helicity present. Main concern is with the isolated elevated hail potential with the decent mid-level lapse rates and LCL heights around 750-1000m AGL. Plus, the severe threat looks limited to sunshine and should decrease past 01z tonight. Sunday night into Monday...Surface high pressure takes over for the rest of the day Sunday and into much of the evening Sunday before a warm front associated with a surface low pressure over the High Plains to enter the state by around 06z Monday. Shortwave energy pushes into western Iowa during this time and continues to press east-northeast into about 12-15z Monday morning. Yet another round of moderate to heavy rain potential along with the isolated severe storms threat from 06z to 15z Monday, but the set up looks to be central to northern portions of the forecast area. Steady moisture transport into northern Iowa and with the best moisture convergence and highest precipitable water in this location, the heavy rain potential is a concern for flash flooding as well as river flooding. The warm front remains draped across the state Memorial Day into early Tuesday with the GFS slightly further north than the ECMWF in the placement. Still, there should be a break in the convection from the morning storms moving east before redevelopment late in the afternoon. This should allow for plenty of time for destabilization to occur south of the front, engulfing at least two-thirds of the forecast area. Uncertainty remains how far north the boundary stalls and thus the location of greatest severe threat. The latest models have trended slightly further south and suspect the severe threat will do as well. Surface based CAPE increases to 2500-3500 J/kg and deep layer shear ranges from 35 to 50 knots from east to west. The low level shear is sufficient for rotating updrafts and the 0-1km helicity along the warm front tops out at around 200 m2/s2 by 00z Tuesday. Certainly Monday afternoon and evening appear to be the best threat for widespread severe storms over central Iowa and something to continue to monitor for any holiday festivities. Tuesday through Saturday... Yet more rain and severe thunderstorm threat with the low pressure system and associated cold front/dryline on Tuesday into Tuesday night. The GFS and ECMWF are in fair agreement with the track of the surface low but the GFS is slower in bringing it eastward. Thus, timing of the low is critical to any severe weather threat on Tuesday. The rest of the work week looks less active with the GFS suggesting a weak shortwave to impact the region by Friday. && .AVIATION.../For the 00Z TAFS through 00Z Sunday evening/ Issued at 609 PM CDT Sat May 25 2019 VFR conditions for northern TAF sites through the period. concerning KDSM and KOTM (especially KOTM)isolated to sct TSRA will produce local MVFR conditions which will impact KOTM the most. Heavy rain, large hail and strong wind possible with storms. && .DMX WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch through Sunday morning for IAZ074-075-081>086- 092>097. && $$ DISCUSSION...Podrazik AVIATION...FAB
Area Forecast Discussion
National Weather Service Quad Cities IA IL
837 PM CDT Sat May 25 2019 ...HYDROLOGY UPDATE... .SYNOPSIS... Issued at 234 PM CDT Sat May 25 2019 What was a dreary start to the day with plenty of overcast and scattered rain showers has turned into a mix of clouds and sunshine as of 2 PM. The MCV that was responsible for this has moved further east, and was producing showers and thunderstorms across the northern Ohio River Valley as of this writing. Temperatures across our neck of the woods currently range from 75 in Sterling, to 83 in Vinton. Dewpoints were in the lower to upper 60s, making it quite humid as well. The warm front that moved across the area yesterday evening stretched from southeast Nebraska to northern Wisconsin, allowing the warm, humid air mass from the Gulf of Mexico to continue building into the area. && .SHORT TERM...(This Evening through Sunday) ISSUED AT 234 PM CDT Sat May 25 2019 Main concerns of the short term period are our chances for showers and thunderstorms this evening through Sunday morning. Latest model analysis shows the warm front will remain north of the area this evening, keeping us locked in the unstable, warm and humid air mass. Several CAMS such as the NAMnest and HRRR continue to show scattered showers and thunderstorms developing across the area around 5-7 PM, similar to how things evolved yesterday. There is a potential for some thunderstorms to become severe, and the latest SPC update has expanded the marginal risk north to the Highway 20 corridor. The primary threats thunderstorms this evening will be large hail and damaging winds with plentiful moisture, steep mid level lapse rates (giving us plentiful CAPE of 2000-3000 J/kg) and the presence of deep vertical shear to work with. Can`t rule out an isolated tornado, but the threat is lower today given the warm front is further north, along with the lack of lower-level shear and helicity. Later this evening, attention turns to how developing convection over eastern Kansas and northwest Missouri evolves as it moves north and east. Models continue to remain in agreement of keeping this convection and the main axis of heavy rainfall around the Highway 34 corridor southward where best moisture advection is focused. Therefore, not planning any changes to the timing or position of the current Flash Flood Watch with this afternoon`s forecast package. With very high PWATs still in place, showers and storms will have no trouble producing locally heavy rainfall amounts of 1 to 2 inches. As mentioned in the previous discussion, it won`t take much to generate water problems given the saturated soils and recent rounds of heavy rainfall (Latest CPC analysis shows the entire area with a soil moisture ranking profile in the 99th percentile). For Sunday, ongoing rain and thunderstorms will diminish and exit the area by morning as advection decreases and the LLJ shuts off. By late morning and early afternoon, expecting sun to begin breaking out from a leftover overcast deck, especially north of I-80, as weak subsidence builds across the Great Lakes. This should make for a mild, yet humid day across the area. Currently have forecast afternoon highs ranging from the middle 70s to near 80, with dewpoints climbing into the lower to middle 60s. .LONG TERM...(Sunday Night through Saturday) ISSUED AT 234 PM CDT Sat May 25 2019 Unfortunately, the threat of showers and thunderstorms will continue to remain each day through at least mid next week. This also includes a threat for severe weather. Sunday night and Monday... Attention turns to how convection that is progged to develop over northern Kansas and central Nebraska evolves Sunday night. Weak area of low pressure is expected to develop over western Nebraska early in the period, which will help transport rich theta-e air across the Midwest Sunday night towards the warm front, which will be draped across northern Iowa and southern Wisconsin. Any activity from this convection will reach our neck of the woods late Sunday night into early Monday. Latest guidance shows the highest QPF of around 1 to 2 inches is expected to track along the warm front, which looks to stay north of the Highway 20 corridor. This will add to uncertainties in how river forecasts will evolve into late next week, especially along the Mississippi River. The Storm Prediction Center has our area outlined in a slight risk for severe thunderstorms Monday afternoon and evening, which will be heavily dependent on how showers and thunderstorms evolve and persist during the morning. However, will need to watch how a shortwave trough evolves as it progresses across the area Monday afternoon and evening, which looks to be the primary driver for convection. If clouds are able to break and build additional instability, showers and storms could develop in the warm sector, which should be fully established across the area. Damaging winds and large hail are the primary threats with storms at this time. In addition, the threat of heavy rainfall with any thunderstorm remains. Tuesday & Tuesday night... Models vary with respect to the warm front position to begin this period. Latest GFS and ECMWF allow the warm front to sag a little south towards the I-80 corridor by 12z Tuesday, while the CMC and NAM keep the front further north into Minnesota and Wisconsin. For now will go with a blended approach, which would keep chances of morning precipitation with the front around the Highway 20 corridor northward. Areas that don`t see rain showers during the morning will be locked under mostly cloudy skies with plenty of moisture advection occurring overhead. Severe weather looks to be a concern once again Tuesday afternoon and evening ahead of a developing cold front approaching the area from the west. Of concern is agreement in the latest guidance of a 50-60 kt mid-level jet ejecting over the region, which would give us high low and mid level wind shear to work with. When combined with CAPE progged between 2000-3000 J/kg, storms that develop along and ahead of the front would be capable of producing all modes of severe weather. This period will continue to be monitored, so stay tuned for the latest information. Wednesday on... Main cold front is progged to move through the area Wednesday morning, which should give us a brief reprieve of wet weather and a disconnect from Gulf moisture through the end of the work week. The GFS and CMC remain a little aggressive with the last runs in bringing a weak shortwave across the area Friday, while the ECMWF remains completely dry. Guidance shows active weather returning by Saturday, but confidence on this materializing this far out is low. Look for changes to this period with the next forecast package. As we head into late May and early June, current trends snow near to below normal temperatures with above normal precipitation across the region. && .AVIATION...(For the 00Z TAFS through 00Z Sunday Evening) ISSUED AT 622 PM CDT Sat May 25 2019 Showers and storms will increase in coverage across the area tonight accompanied by periods of MVFR to IFR conditions, as a cool front sags through the region. A few severe storms are possible this evening with large hail and damaging winds, which could impact BRL and possibly MLI. The precipitation will dimnish Sunday morning with a return to VFR conditions. && .HYDROLOGY... Issued at 832 PM CDT Sat May 25 2019 No significant changes noted in the forecasts this evening. During this active pattern through early next week it is important to remember that river forecasts do not include rainfall beyond 24 hours. Therefore, any changes in the distribution or amounts of rainfall will lead to significant changes in the forecasts. Previous discussion Issued at 1117 AM CDT Sat May 25 2019 Rainfall from Friday and Friday night ended up being well less than had been forecast. Heavy rain had been expected from northeast Missouri through north central Illinois, but that area was largely missed Friday night, which has led to lowered forecasts for most forecast points with this morning`s forecasts. Some tributary rivers did have forecasts drop enough to allow the cancellation of the warnings. On the Mississippi River, the most noticeable changes were to the Rock Island LD15 gage and downstream due to the much lesser inputs from the Rock River. Later expected precipitation (mainly from Monday and Tuesday) will likely cause the forecasts to rise higher than the current forecast levels, but the degree of the rises will be dependent on what areas will receive the rains and those rains will likely not be included in the forecasts until Monday and Tuesday`s forecasts. Locations that have the highest chance for seeing widespread rainfall today will be far southern Iowa into west central Illinois and southward, while more scattered activity is expected to the north through Sunday morning. Showers and storms are still possible on Sunday as well, but not looking for widespread heavy rains locally, so much of the area is likely to see almost 2 days without soaking rains. Sunday night into Monday is the next chance for widespread heavy rains, but the current track of the complex of storms is expected to be centered into northern Iowa, Minnesota, and Wisconsin. So it will have an impact on rivers, but maybe not as big of an issue for flash flooding. Then Tuesday and Tuesday night the entire area has a threat for heavy rain. Overall, the miss of last night`s rain is significant in the forecasts as it should lead to a lower chance to reach the high levels that have been advertised this past few days. That being said, with chance for rain every day still through Tuesday night, a lot can change in the forecasts as crest level expectations are still highly dependent on the forecast rains over the next 5 days. We urge people with interests in the rivers to stay in tune with the latest information. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...Flash Flood Watch until 7 AM CDT Sunday for Des Moines-Henry IA- Jefferson-Keokuk-Lee-Louisa-Muscatine-Scott-Van Buren- Washington. IL...Flash Flood Watch until 7 AM CDT Sunday for Bureau-Hancock- Henderson-Henry IL-McDonough-Mercer-Putnam-Rock Island- Warren. MO...Flash Flood Watch until 7 AM CDT Sunday for Clark-Scotland. && $$ SYNOPSIS...Speck SHORT TERM...Speck LONG TERM...Speck AVIATION...McClure HYDROLOGY...Brooks/McClure
National Weather Service Kansas City/Pleasant Hill MO
638 PM CDT Sat May 25 2019 .Discussion... Issued at 308 PM CDT SAT MAY 25 2019 Our active weather pattern will continue this afternoon into the overnight hours, but some uncertainty does exist within both the possible periods of weather. For this afternoon the main concern will be possible strong to severe storms over northern Missouri in an area of surface convergence ahead of a quasi-stationary boundary. There is currently a capping inversion around 6kft which has created a solid stratocumulus deck over the area and my actually help inhibit additional heating and chances to break this cap. CAMs continue to indicate that there will be just enough lift in the mid levels and warming on the surface to help stretch this layer and help break this cap around 4-5pm. We are still leaning towards this occurring as surface temperatures have gotten into the upper 70s and dewpoints are now just below 70 which was needed for this to occur. If the cap does break this afternoon we will have around 2500-3000 J/kg of MLCAPE and 50kts of effective bulk shear. Soundings indicate that supercells are possible and large hail (up to golf balls) and damaging winds will be the main threat. The DCAPE values will be near 1200 J/kg so this does indicate strong downbursts are possible with these storms. This activity will be mainly limited to HWY 36 and north with only some isolated showers and storms possible south of that due to no real forcing mechanism to focus on. The next threat for the area appears to be a possible QLCS that is expected to form out over TX/OK/KS and slowly propagate up into our area around midnight. There are many factors that could change the storm mode and severity of this line as it pushes through, but the HRRR does tend to have favorable low level shear to keep this system balanced and possibly a wind threat with potential mesovorticies along any surges. While the severe weather threat is there with this line the main impacts may actually be flooding as a quick 1-2" is possible with this system. Our flash flood guidance has recovered some this afternoon but most of the area in the flash flood watch has less than 2" for 1 and 3 hour periods. The western side of the KC Metro and down along I-35 corridor and north central Missouri have the lowest guidance and would be the main area of concern overnight. Models are also hinting at a strong LLJ forming early in the morning that may help initiate new convection or at least provide enough isentropic accent to form showers and storms over eastern KS and western Missouri around sunrise and into the late morning. This would not be favorable for the area and would be a possible flood setup so this will need to be watched as a possibility as the evolution of the possible QLCS is observed this evening. A shortwave will exit the Rockies Sunday night causing a low pressure to form with a warm front extending into NW Missouri on Sunday afternoon. This could redevelop some showers and storms, with some being strong to severe, Sunday evening into the overnight hours. This low pressure system will track to the north Monday setting up the stage for severe weather Tuesday. The timing of the cold front pushing through on Tuesday afternoon is what makes this setup worth watching. We will be in the warm sector all day with no real morning MCS threats to kill our heating chances. A strong upper and mid level jet over eastern KS will provide plenty of shear with instability present. The details will reveal themselves as we get closer to the event. Finally! A few dry days look possible Wednesday afternoon through Friday late morning giving us at least a small window to dry out. Unfortunately this window will not last long as troughing and another wet pattern sets up going into next weekend and early next week. && .Aviation...(For the 00Z TAFS through 00Z Sunday Evening) Issued at 638 PM CDT SAT MAY 25 2019 Isolated thunderstorm development is possible over the Kansas City Metro TAF sites with scattered thunderstorms and MVFR conditions developing over northern Missouri which will be more of an impact for KSTJ through 06Z. After 06Z, expect a north/south line of thunderstorms in eastern Kansas to move east into western Missouri and impact all TAF sites with MVFR conditions and possible IFR conditions in heavier precipitation. Expect MVFR ceilings by 10Z improving to VFR by 15Z and winds will predominately southerly 6-10kts, outside of convection. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...Flash Flood Watch through Sunday morning for KSZ025-057-060- 102>105. MO...Flash Flood Watch through Sunday morning for MOZ001>008-011>017- 020>024-028>031-037-038-043-044-053. && $$ Discussion...Barham Aviation...32/Otto
Area Forecast Discussion
National Weather Service Hastings NE
704 PM CDT Sat May 25 2019 .SHORT TERM...(This evening through Sunday) Issued at 418 PM CDT Sat May 25 2019 A weak disturbance is moving across the Central Plains this evening and tonight. A couple rounds of thunderstorms are possible. The first round has begun in extreme southeast Colorado and southwest Kansas. This activity is expected to grow and evolve cluster of storms that moves through north central Kansas and portions of south central and southeast Nebraska. Watching the higher-resolution models, the HRRR/NAMNest/NAM and RAP all show this evolution from western Kansas northeast into north central Kansas and further northeast into Northeast Kansas and southeast Nebraska. The models hint at a couple of rounds with the initial wave moving through this evening and a secondary round during the overnight hours. How far this activity may spread northward is the question. Feel the best chance for thunderstorms will be along and south of I-80...especially south for areas south of the Nebraska/Kansas state line. With the abundant MUCAPE and MLCAPE of over 2000 J/KG and 40-50 kts shear, severe storms are possible...mainly for areas along and south of the NE/KS Border. These storms could produce large hail up to golf ball size and damaging winds to 60. A Flash Flood Watch continues from 7pm tonight to 7am Sunday for north central Kansas. The ground is saturated and any additional rain...even another inch or so could cause some flooding and rises in rivers. .LONG TERM...(Sunday night through Saturday) Issued at 418 PM CDT Sat May 25 2019 The active period continues through Tuesday as the upper trough sits off to the west and multiple disturbances round the base of the trough until it moves through early in the work week. The next disturbance moves ejects northward out of the trough Sunday afternoon. The weak boundary that is draped across the region is expected to lift northward tonight and early Sunday putting the whole region in the warm sector. Thunderstorms are expected to develop in the western High Plains in Kansas Sunday afternoon and spread northward. Most of the area is in the SPC Day 2 Enhanced and think that is fairly good with abundant instability and shear. Low level helicity also increases over northwest Kansas and into north central Kansas and parts of southwest and south central Nebraska. With this, a tornado or two is not out of the question. This activity is expected to lift northward across the heart of the forecast area during the overnight hours bringing the best potential for additional rainfall to much of the forecast area. May see another flood watch for this time period Sunday. The main disturbance will rotate around the base of the trough and begin to eject to the northeast for Monday. This disturbance and upper wave will tighten up the frontal boundary and will bring another potential for severe thunderstorms as the surface low moves across the area. The better chances will be along and north of I-80, but cannot rule it out across the whole area with ample shear and instability. Highs through the Holiday weekend will be in the 70s to low 80s. The upper low will finally move east enough to push the surface front into eastern Nebraska and Kansas sometime on Tuesday. The trend has been for this to slow, so the current severe risk which is just east of the area, could move westward if the front slows. Something to watch for Tuesday. Wednesday and Thursday look quieter with the Plains under northwest flow for a brief period. Temperatures will cool back down slightly, but most importantly there is a lull in precipitation. By the end of the work week, southwesterly flow will return and another disturbance will cause the chance for showers and thunderstorms to return for the end of the week. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Sunday) Issued at 642 PM CDT Sat May 25 2019 Ceilings will be the toughest to forecast as the two terminals will be on the northwestern fringe of convection that could move through this evening and into the overnight. Confidence is quite low, and could potentially vary quite a bit from hour to hour. The overall trend into Sunday should be for MVFR ceilings, however. There is a better chance for storms on Sunday evening, just past 00Z, moving in from the west. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...Flash Flood Watch through Sunday morning for KSZ005>007-017>019. && $$ SHORT TERM...Billings Wright LONG TERM...Billings Wright AVIATION...Heinlein
Area Forecast Discussion
National Weather Service Goodland KS
935 PM MDT Sat May 25 2019 .UPDATE... Issued at 932 PM MDT Sat May 25 2019 Strong/severe storms have moved out of the area. A few areas may see a shower or isolated thunderstorm overnight. UPDATE Issued at 758 PM MDT Sat May 25 2019 With all major strong/severe convection having shifted east of the CWA...have cancelled the Severe Thunderstorm Watch. Locales could still see a shower or an isolated thunderstorm over the next couple hours. && .SHORT TERM...(This evening through Tuesday) Issued at 245 PM MDT Sat May 25 2019 Tonight-Sunday night...general idea is for convection to approach the far southern portions of the forecast area by 22z-23z with models either increasing coverage to the northeast which would flirt with our east through southeast zones or straight north (RAP model) through early to mid evening. Convection may redevelop and intensify after midnight generally east of a Joes to Goodland and Russell Springs line (experimental HRRR most aggressive with more subtle qpf output from other models) lifting northeast and exiting the area while weakening by sunrise Sunday morning. Widespread stratus expected with some fog possible within a few hours of sunrise. For Sunday through Sunday night strong to severe thunderstorms are possible across the far southern forecast area as early as 18z before lifting north and increasing in coverage and intensity during the afternoon. The entire forecast area is under an enhanced risk of severe weather per SPC day 2 outlook. Convection should come to an end around midnight before a strong mid level dry slot moves in from the southwest putting an end to precipitation chances. Low temperatures tonight range from the upper 40s to low 50s in far eastern Colorado to the mid/upper 50s in Norton and Graham counties. High temperatures Sunday should range from the mid and upper 70s east of the CO/KS border where low clouds may linger for much of the day to the low 80s along and west of the CO/KS border. Low temperatures Sunday night range from the mid 40s to around 50 in the west, near 60 in the east. Monday...its possible for a few strong to severe thunderstorms to develop in the mid to late afternoon hours along and east of a line from near Trenton to Colby and Oakley near a NAM model dryline. The GFS model continues to have this feature well east of the forecast area. For now will keep forecast dry per coordination with surrounding offices. Southerly winds increase in the afternoon with gusts in the 30 to 40 mph range expected. High temperatures in the mid 70s to mid 80s. It appears the most likely scenario at this time is for some showers and thunderstorms to move into the far north and northwest portions of the area after midnight as an upper level low pressure area moves toward the area from west central Colorado. Low temperatures range from the low to mid 40s west, mid 50s east. Tuesday...general idea is for the upper low to continue moving northeast into central Nebraska during the day with some wraparound rain showers during the day across the northwest 1/2 of the area. Afternoon temperatures will be much cooler with readings ranging from the upper 50s to mid 60s in far eastern Colorado to the mid 70s in Norton and Graham counties. Some wrap around rain showers possible north of the interstate Tuesday evening. Low temperatures in the upper 30s to low 40s west, upper 40s east. .LONG TERM...(Wednesday through Saturday) Issued at 245 PM MDT Sat May 25 2019 Wednesday...dry weather currently expected. High temperatures in the 60s to around 70. Low temperatures in the 40s. Thursday...precipitation chances return to the forecast as some moisture associated with a weather disturbance moves across the area from the west-southwest. High temperatures in the 70s. Lows range from the mid/upper 40s west to mid 50s east. Friday...some weak disturbances move across the area from the west/southwest supporting spotty chances for thunderstorms. High temperatures in the mid 70s to low 80s. Low temperatures in the mid 40s to around 50 west, mid 50s east. Saturday...little change from Friday with a chance of afternoon thunderstorms. High temperatures in the 70s. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 515 PM MDT Sat May 25 2019 Both terminals will be on the north side of a frontal boundary for much of the forecast period. This front will transition over the region after 12z Sunday...increasing the chances for precipitation. For KGLD...VFR skies thru 06z Sunday...then MVFR ceilings/vcsh thru 09z. From 09z-15z IFR ceilings around OVC004-008 with IFR fog from 12z-15z. Conditions increase to MVFR from 15z-20z Sunday...then from 20z onward...VFR with vcsh. Will keep as such due to low confidence in timing so far into the forecast period...but will trend to vcts/tsra with the next issuance/two. For KMCK...VFR skies thru 06z Sunday...then MVFR ceilings from 06z-12z w/ vcsh. IFR skies around OVC005-009 from 12z-19z...then a quick increase to MVFR with some patchy fog from 12z-15z. Finally VFR from 22z Sunday onward. Will keep as such due to low confidence in timing so far into the forecast period...but will trend to vcts/tsra with the next issuance/two. Winds...a general ESE direction for both taf sites around 5-15kts. Strongest winds will occur before 06z Sun...and after 20z-22z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...AW SHORT TERM...99 LONG TERM...99 AVIATION...JN
Area Forecast Discussion
National Weather Service Indianapolis IN
1143 PM EDT Sat May 25 2019 .UPDATE... The AVIATION Section has been updated below. && .SYNOPSIS... Issued at 336 PM EDT Sat May 25 2019 An active weather pattern will remain in place with chances for showers and thunderstorms and above normal temperatures for much of the next week. && .NEAR TERM /Overnight/... Issued at 942 PM EDT Sat May 25 2019 Surface analysis this evening shows high pressure in place across the deep south with warm and humid SW flow streaming across Indiana. A cluster of thunderstorms had developed over SE Iowa and NE Missouri. Skies across Central Indiana were continuing to clear as convection related to the heating of the day continued to diminish. 850mb-300mb model thicknesses suggest propagation of the Iowa thunderstorms to reach Central Indiana late overnight. HRRR is also in agreement...pushing showers/storms across the northern parts of the forecast area after 09Z...persisting until nearly 14-15Z. Time heights and forecast soundings suggest ample moisture and lift...thus have trended pops higher overnight than the previous forecast. Also given the expected clouds and rain...trended overnight low at or above the model blends. && .SHORT TERM /Sunday through Monday Night/... Issued at 336 PM EDT Sat May 25 2019 Forecast focus is on timing for rain and storms for the remainder of the holiday weekend. Unfortunately models are still not in good agreement on timing of QPF over the area, so medium confidence is going to be the best this forecaster can offer. That said, for those with outdoor plans contingent on dry weather, here it goes. An upper wave moving through during the late overnight/early morning hours will have rain ongoing across much of northern and central Indiana as Sunday morning begins. Expect this first wave to move off to the east and allow for a few dry hours, starting late morning (9-11 am) and ending in the early afternoon (1-3 pm), depending on your location. In the hourly forecast, show this in the form of PoPs of 20-30 percent during the "most likely to be dry" hours. The potential problems with this timing is where the front sets up. Fairly confident on the timing of the upper waves (early morning, then arriving early to mid afternoon), but not confident on the exact location of the front. This could again serve as a focusing mechanism for convection and increase severe potential, and it could legitimately set up anywhere in Indiana depending on what happens with the first wave of convection in the early morning. Sunday night the upper wave will move out and convection will end, bu the front possibly moving north through the area during the day on Monday could prompt some showers and storms for the holiday. Those chances are lower at this time due to uncertainty regarding the frontal position, but the upper forcing looks far less impressive than Sunday afternoon. All of these waves over the same general area raises the concern for flooding, and will have to monitor this closely going forward. At this time not expecting a widespread threat, so will forgo any flood headlines. High tempertures Sunday will be highly dependent on cloud cover and the aforementioned precipitation that develops. Went toward the middle of guidance in the lower to mid 80s, with high humidity as well. Monday should be a few degrees warmer. && .LONG TERM /Tuesday through Saturday/... Issued at 336 PM EDT Sat May 25 2019 Temperatures will run slightly above normal through the long term, and an active weather pattern with a trough over the western U.S. spitting out shortwaves that will bring thunderstorm chances to central Indiana Tuesday night through Thursday. The pattern will become flatter and more progressive toward the end of the week. && .AVIATION /Discussion for the 260600 Tafs/... Issued at 1142 PM EDT Sat May 25 2019 Mainly VFR conditions will be expected this taf period in between periods of showers and thunderstorms. VFR conditions are expected to continue the next few hours. SHRA and TSRA are expected in the area after 09Z-10Z. Brief MVFR to IFR conditions will be possible with any thunderstorm. Showers and Storms over Central Illinois are expected to propagate to central Indiana after 09Z. Models then suggest this short wave will depart the area near 12Z before another short wave arrives after 15Z. Ample moisture and forcing appear present. Thus will trend toward VFR conditions with prevailing SHRA/vcts after 20Z- 21Z. Again...any shower or storm that strikes a taf site may result in brief IFR conditions. Sundays short wave should depart by 22Z-24Z...and a return to VFR will be expected within the wake of the any storms overnight. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CP NEAR TERM...Puma SHORT TERM...CP LONG TERM....CP AVIATION...JP
Area Forecast Discussion
National Weather Service North Platte NE
632 PM CDT Sat May 25 2019 .SHORT TERM...(This evening through Sunday night) Issued at 334 PM CDT Sat May 25 2019 A few light rain showers and isolated thunderstorms remain possible for tonight. Any thunderstorms that do develop are expected to remain sub-severe, however, still capable of producing small hail and gusty winds. Overnight lows are expected to fall into the upper 40s to mid 50s. Active weather is expected for Sunday with thunderstorms possible through the day. Any thunderstorms during the day are not expected to be severe at this time. Instability will increase late in the day Sunday which will increase our severe weather potential heading into Sunday night. Models are indicating that a long-lived convective line of storms will move through during the overnight hours Sunday into Monday morning. Large hail and damaging winds will be the main focus through the night. .LONG TERM...(Monday through Saturday) Issued at 334 PM CDT Sat May 25 2019 We will see quite an active weather pattern from Monday through Wednesday as a series of disturbances are expected to move through the Central Plains. This will bring rain and isolated thunderstorm chances across the area through Wednesday. Strong to severe thunderstorms will be possible on Monday as a warm front across central Nebraska will become a focus for thunderstorm development. Heavy rain will also be a concern from Monday to Wednesday. Forecast rainfall totals through Wednesday morning range from 1 to 2 inches across northern Nebraska. Forecasted rain along with saturated soils from previous heavy rainfall has increased our concern for flooding across this area. Dry and quiet weather will take over the region on Wednesday and much of the day Thursday. There are a few isolated chanced of rain and thunderstorms late in the day Thursday and Friday, however, confidence remains low at this time. For temperatures, the week will begin warm on Monday. Slightly cooler temperatures will move in on Tuesday, with the coolest temperatures across the northwest Sandhills. Wednesday will see highs in the 60s followed by 70s for Thursday, Friday and into the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 632 PM CDT Sat May 25 2019 VFR conditions this evening transitioning to MVFR and eventually to LIFR at KLBF by Sunday morning. Weak convection moving across the far northern Panhandle currently which most CAMs including the HRRR have a decent handle on. This driven by weak convergence and flow around the Black Hills and higher terrain to the west. Low level moisture is lacking in this area and wouldn`t expect continuation past sunset and not looking like it will make it to KVTN. Lower cloud deck moves in overnight in the south in association with a larger area of convection to the south and northward moving warm front. Have introduced light fog at KLBF Sunday morning based on short range model soundings and larger scale pattern association. Better TSRA chances after the end of the forecast period. && .HYDROLOGY... Issued at 334 PM CDT Sat May 25 2019 River levels have been relatively steady on Elkhorn river at Atkinson and Ewing today. Near Atkinson, the river is above minor flood stage with the latest reading at 8.22 ft. A Flood Warning remains in effect for west central Holt county through 7 am Sunday morning. Elsewhere, a Flood Warning also remains in effect in northern Brown County where water continues to overtop Pine Canyon Dam on the Plum Creek. This warning goes into mid morning Sunday. A Flood Advisory continues until 10 am Sunday for the Keya Paha River in northeast Keya Paha and west central Boyd County. River levels upstream, notably Wewela on the Keya Paha, have started to go down thus the threat is expected to lower. Lastly, A Flood Advisory remains in effect through 145 pm Sunday from the Cedar River in southwest Wheeler County. Looking ahead, storms and significant rainfall totals are possible Sunday night through the first half of the week. A Flood Watch is in effect Sunday evening through Tuesday afternoon. The heaviest widespread rain is expected to occur Sunday night, Monday night, and Tuesday. A lull in activity is expected during the daytime Monday. Overall, total rainfall amounts of 1 to 2 inches are forecast with locally higher amounts possible across the north central. The additional rainfall will increase the potential for flooding due to already saturated soils, increased runoff, and high water tables. && .LBF WATCHES/WARNINGS/ADVISORIES... Flood Watch from Sunday evening through Tuesday evening for NEZ004>010-023>029-094. && $$ SHORT TERM...Thorne LONG TERM...Thorne AVIATION...Stoppkotte HYDROLOGY...Roberg
Area Forecast Discussion
National Weather Service Marquette MI
635 PM EDT Sat May 25 2019 .SHORT TERM...(This evening through Sunday) Issued at 415 PM EDT SAT MAY 25 2019 Water vapor imagery and RAP analysis show a shortwave lifting ne thru northern Ontario. At the sfc, trailing cold front extends across far se Lake Superior and eastern Upper MI. Latest SPC mesoanalysis shows mlcape edging up toward 300j/kg ahead of the front in a narrow zone btwn the front, which is now surging s due to lake breeze assistance, and the edge of the Lake Michigan modified air mass under ssw winds. Deep layer shear is on the order of 60- 70kt. Vis satellite imagery shows vigorous looking cu vcnty of the southward surging cold front/lake breeze, and a few short-lived -shra are occasionally appearing. Remains to be seen if any tsra will develop in the next couple of hrs, but there may be too much shear for the limited instability to get any storms going. Given the instability/shear, if any storms do develop, a svr storm is possible until front clears the area in the next few hrs. Behind the front, gusty w to nw winds have taken hold under deep mixing, aided by caa and incoming 3-4mb/3hr pressure rises. Wind gusts of 25-35mph are common with some gusts to 35-45mph over the Keweenaw. Deep mixing has allowed dwpts to crash in a corridor from around KLNL toward KSAW. With temps mid 70s to around 80F, RH has plummeted to 25-30pct. Stratocu that has developed off to the w in ne MN/nw WI under approaching 850mb thermal trof has struggled to spread all the way across the cold/stable marine layer over Lake Superior, a typical scenario for this time of year. A few shra, maybe a tsra, will develop over the eastern fcst area for the next couple of hrs until front exits. Otherwise, expect some of the stratocu to the w to spread into the area this evening before fading away during the night. Winds will remain gusty until the loss of solar insolation. With winds diminishing and skies trending toward mostly clear, some of the traditional cold spots may dip blo 40F tonight. Otherwise, 40s will be the rule for low temps. On Sun, shortwave swinging across far northern Ontario will push an associated cold front s across Lake Superior and into Upper MI though front gets somewhat difficult to locate in the aftn due to lake breeze development. Limited instability (mlcape under 100j/kg) and evidence of a warm nose/weak capping inversion should prevent any -shra development. So, not expecting anything more than sct flattening cu on Sun, perhaps bkn cu vcnty the lake breeze boundaries during the mid and late aftn. Will still be warm away from lake moderation with highs in the low to mid 70s. .LONG TERM...(Sunday night through Saturday) Issued at 326 PM EDT SAT MAY 25 2019 After the passage of a cold front during the day Sunday, weak surface high pressure centered near the Ontario/Manitoba border Sunday night will keep conditions relatively quiet. A very weak shortwave and some minor convergence at low levels is possible and with a moist air mass in place the possibility exists to squeeze out a few showers, mainly over northwestern Lake Superior. Essentially the only model producing any rain over the central and eastern CWA at this point is the NMM, but I opted to add some slight chance POPs. As a mid-upper level low slowly translates east through the inter- mountain west Monday, a shortwave will push out ahead of it across the Great Lakes. The main area of forcing for ascent has shifted south a tad over the last few model runs, with rain crossing the WI border Monday afternoon. Should move out to the east late Monday night. QPF will be highest over Menominee County where >0.5" are possible, with generally a widespread 0.2-0.4", and less than 0.1" over the far NW. CMC is out to lunch Tuesday morning with widespread rain remaining through the morning hours while the deterministic GFS and ECMWF are dry. However, with several GEFS members predicting some additional shower activity, the slight chance to low end chance pops loaded by the blend were mostly left alone for the time being. Tuesday night, there is more agreement in a dry period, but as the low over the western CONUS opens up and increases in eastward propagation speed, it is expected to bring additional chances for showers and possibly a few thunderstorms on Wednesday into Wednesday night. Timing and QPF amounts will remain uncertain for the time being as model agreement leaves a little to be desired. Surface high pressure is expected to build back into the area behind Wednesday`s shortwave and should yield drier conditions later Wed night through Friday with some seasonally cool air expected to filter in. Models then show a nw flow trough and associated cold front moving through, with this feature slowing from previous model runs. It now appears more likely on Saturday into Sunday, bringing another round of showers across the area and a reinforcing shot of cooler air. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 635 PM EDT SAT MAY 25 2019 Drier air flowing into the area will allow VFR conditions to prevail at KIWD/KCMX/KSAW thru this fcst period. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 415 PM EDT SAT MAY 25 2019 On Lake Superior, gusty westerly winds of 15-25kt, with gusts to around 30kt, following passage of cold front will diminish tonight. Late tonight thru Sun morning, winds will be under 15kt. Another cold front dropping s across Lake Superior on Sun will bring a brief period of stronger winds, affecting mainly western Lake Superior where ne wind gusts of 20-30kt will be possible for a few hrs following passage of the front in the late aftn and early evening. Winds will then be under 20kt Sun night, lightest over the e half of Lake Superior. NE winds may increase some on Mon, gusts to 20-25kt, mainly over western Lake Superior. Winds should then be under 20kt thru the middle of the week. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... Dense Fog Advisory until 8 PM EDT this evening for LMZ248-250. && $$ SHORT TERM...Rolfson LONG TERM...KCW AVIATION...07 MARINE...Rolfson
Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
942 PM EDT Sat May 25 2019 .AVIATION... The forecast of isolated showers in SW VA has worked out well this evening, but the slight chance PoP will need to be extended southward and a few hours later as radar shows some showers developing in NE TN. The HRRR and RAP did well to depict this development. Only PoP/Wx/sky grids will be adjusted as temps are on the right track. && .MRX WATCHES/WARNINGS/ADVISORIES... NC...None. TN...None. VA...None. && $$ DGS
Area Forecast Discussion
National Weather Service Omaha/Valley NE
619 PM CDT Sat May 25 2019 .SHORT TERM...(Tonight through Tuesday) Issued at 325 PM CDT Sat May 25 2019 The main concerns in the short term focus around thunderstorms intensity/coverage/rain amounts. The active southwest flow pattern in the mid levels will remain in place through Tuesday. A closed low will drop southward along the west coast through Sunday night, move out into northern CO by early Tuesday and then across parts of western and central NE through Tuesday night. Day 1 SPC outlook shows a marginal risk of severe storms in our southern zones through tonight. This seems reasonable. Because the soil is already very wet in parts of the area and we expect at least some storms tonight, will keep the flash flood watch in place. Surface dewpoints south of the front are in the 70s across KS this afternoon. That humid air should move up into southeast NE and southwest IA Sunday. Kept main thunderstorm chances across the southern half of the forecast area tonight. Precipitable Water (PW) this afternoon are an inch or higher across our southern zones, and that should increase through Sunday. Surface high pressure in place over the eastern Dakotas/MN/parts of IA and NE will build to the east tonight and pressure will start to fall over the high plains. This will cause southerly flow to increase with low level convergence along the boundary. 20Z mesoanalysis showed about 2000 J/kg of CAPE for the lowest 100 mb mixed layer. Recent HRRR and ESRL HRRR models suggest storms will increase in coverage mid to late evening, then decrease after midnight, with another potential round of showers/storms from around sunrise into mid morning Sunday. Storm chances the rest of the day seem lower, with an increase toward Sunday evening into Sunday night. Timing will be difficult beyond that, but it does look most active in the evening and overnight. Additional flash flood watches may be needed the next few nights but will do these on a day by day basis. .LONG TERM...(Tuesday night through Saturday) Issued at 325 PM CDT Sat May 25 2019 Pattern remains Tuesday night and Wednesday, but then we SHOULD get a bit of a break as the flow turns more zonal for Wednesday night through Thursday. Storm chances will return for at least parts of the area Friday through Saturday. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 615 PM CDT Sat May 25 2019 VFR conditions will prevail at KOFK/KOMA thru the fcst pd. At KLNK, sct TSRA will begin lifting out of KS into SE NE later this evening. Expect a few TSRA to move through KLNK sometime around midnight. Improvement to VFR shortly after. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...Flash Flood Watch through Sunday morning for NEZ088>093. IA...Flash Flood Watch through Sunday morning for IAZ080-090-091. && $$ SHORT TERM...Miller LONG TERM...Miller AVIATION...DEE
Area Forecast Discussion
National Weather Service Pendleton OR
818 PM PDT Sat May 25 2019 .SHORT TERM...Tonight and Sunday...made some changes for the overnight reducing the amount of showers over the Washington Cascades and then increasing them on Sunday. This due to models wrapping moisture over central Idaho across central Washington overnight and then into the Cascades early Sunday. The upper level low dropping down the coast tonight will be into California on Sunday. This is responsible for the convective showers this evening over the eastern portion of the forecast area and the steady rain in central Oregon. Sunday will again be convectively unstable for most of the forecast area except the east slopes of the Washington Cascades where the steady light rain is expected. Increased the chance of thunderstorms over northeast Oregon and southeast Washington from slight chance to chance Sunday afternoon as instability will be a little better in this area. && .PREV DISCUSSION... /issued 300 PM PDT Sat May 25 2019/ SHORT TERM...Tonight through Tuesday...A closed low spinning off the Washington coast will travel south and will be centered near Brookings, OR by midnight. A broad circulation will be present over the western half of the U.S. through Memorial Day associated with the large low pressure system. The cyclonic flow aloft and increasing instability will make for a somewhat challenging forecast over the next few days to pinpoint where showers and thunderstorms will develop. Just about anywhere in the forecast area has at least a slight chance of showers and thunderstorms. For tonight, a weak wave will bring showers and isolated thunderstorms across northeast Oregon and southeast Washington. SBCAPEs are around 500 J/kg from the latest SPC`s Mesoscale Analysis, and the HRRR tracks one cell southeast to northwest over the Blues and into the Blue Mountain Foothills this evening. Dewpoints in most areas are in the 30s to lower 40s, so the possibility of anything more than isolated thunderstorms is slim. The low will be located over northern CA on Sunday, and multiple waves rotating around the low will bring showers and isolated thunderstorms to the forecast area. Once again, just about anywhere has a slight chance of thunderstorms and this was included in the forecast. Thunderstorms are not expected to be strong or severe but could bring frequent lightning and heavy rain. On Memorial Day, the low will approach the four-corner states. This broad circulation with multiple embedded waves will bring a chance of showers and a slight chance of thunderstorms to the forecast area. By Tuesday, the low will be far east and out of range, but a northerly flow aloft will be present with lingering moisture and instability for isolated showers and thunderstorms, mainly over southeast Oregon. No wind concerns are anticipated in the short term, but there will be occasionally breezy NNW winds on Sunday and Monday. The higher peaks of the Wallowas, Elkhorns, Strawberries, and Cascades--mainly above 7000 feet---will also have periods of snow this holiday weekend. Wister LONG TERM...Tuesday night through Saturday. Extended models have some slight differences in the overall pattern. In general it appears the Pacific northwest will remain in a weak trough pattern. The result will be partly cloudy skies with daytime instability producing scattered showers and thunderstorms mainly over the mountains. Best chances will be central and northeast Oregon. 850mb temps warming and will give highs in the 70s to lower 80s. No significant winds expected through the period. 94 AVIATION...00z tafs. Scattered showers and isolated thunderstorms for PDT ALW and possibly PSC through evening then decreasing. Showers or a stratiform rain for YKM DLS RDM BDN associated with the upper low offshore. This will diminish overnight. Winds 5-15kt except 10-25kt DLS. Scattered showers and storms again Sunday. 94 && .PRELIMINARY POINT TEMPS/POPS... PDT 48 69 50 74 / 30 30 20 10 ALW 50 72 53 76 / 30 40 20 20 PSC 55 75 55 83 / 20 40 20 10 YKM 50 68 52 80 / 20 60 10 20 HRI 51 73 53 80 / 30 20 20 10 ELN 46 65 49 77 / 20 70 20 20 RDM 40 64 45 70 / 80 40 40 40 LGD 44 67 49 67 / 70 70 30 30 GCD 43 64 47 66 / 60 80 40 30 DLS 49 73 55 80 / 20 20 20 30 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ 91/91/91
Area Forecast Discussion
National Weather Service Pueblo CO
852 PM MDT Sat May 25 2019 .UPDATE... Issued at 849 PM MDT Sat May 25 2019 Quick update to incorporate latest obs data as well as satellite and radar trends. Added some patchy fog to portions of the eastern plains overnight. Moore && .SHORT TERM...(This evening through Sunday) Issued at 316 PM MDT Sat May 25 2019 ...Severe Weather expected across the eastern plains this afternoon and again Sunday afternoon... A severe thunderstorm watch is in effect until 9 PM for the far southeast plains of Baca, Bent, and Prowers Counties. We`ve already issued a few warnings and we expect a few more storms to initiate along a convergence zone currently analyzed on GOES-16 (and surface mesonets) to be across the middle of Baca County westward into eastern Las Animas County. South of the boundary dewpoints are in the mid to upper 50s, which is a bit lower than the high res models had been indicating for this afternoon. As a result, surface-based CAPE will also be less than originally expected, but we still expect 1500-2000 J/kg, enough for severe- sized hail up to golf ball in size and potentially damaging straight line winds to 60 mph. 0-6 km wind shear is still excellent for supercells, and new storms should fire along the boundary and more quickly northeast across Baca, Prowers, and SE Bent Counties through 6-7 PM or so. Conditions across the rest of our area are too dry for precipitation the rest of today and tonight. After the storms move into Kansas from extreme southeast Colorado, we should be dry all night area-wide. We`ve been watching the potential for patchy fog across Crowley and Kiowa Counties in the moist upslope flow along the east side of the Palmer Divide eastward into Kansas. The HRRR originally had it pushed west into the COS metro area, but has recently backed off that solution. Have included patchy fog into eastern El Paso, northern Crowley, and Kiowa Counties after 3 AM. Convective outflow from storms in Kansas would enhance the moist low-level flow, increasing fog potential along the south and east side of the Palmer Divide, but confidence in any fog making it to the I-25 corridor is low at this time. Sunday looks to be a repeat of this afternoon across our area, including the potential for severe weather, albeit a little further west and north than this afternoon. SPC has our far eastern zones in an enhanced risk of severe weather Sunday afternoon. As with today`s severe weather, the threat and impacts depend mostly on how far north and west the low-level moisture can get. For now the moisture looks to make it east of a line from Kim to La Junta to Limon. The surface convergence zone behaves much more like a traditional dryline Sunday afternoon, with good southwest winds to the west along with warm/very dry air. Dewpoints to the east of the dryline should reach the upper 50s. Convergence along the dryline should initiate a few storms after 2 PM, especially given the mid-80s temps at the surface that are expected. Surface based CAPE values again support severe weather, with 2500-3000 J/kg. 0-6 km shear also supports supercells as the primary mode of convection, with 45-50 kts. Dryline-relative flow and a good capping inversion at 700 mb means storms should be fairly discrete as they move northeast off the dryline. Low- level wind shear/SRH and a lack of a secondary boundary (other than the dryline) means the threat of tornadoes is probably low. The biggest impacts tomorrow will be large hail and damaging wind gusts. Aside from the severe threat, the mountains should see diurnal convection Sunday afternoon into the evening with lightning and gusty winds the main impacts. Some of the storms may survive the trek east, but just an isolated chance across the Palmer Divide, Raton Mesa, San Luis Valley, and the Wet Mountain Valley. High temperatures will range from upper 70s to mid 80s across the plains, to the low 70s in the San Luis Valley and upper Arkansas basin, and upper 40s and 50s in the mountains. .LONG TERM...(Sunday night through Saturday) Issued at 316 PM MDT Sat May 25 2019 Storms that form Sunday afternoon should be moving east into Kansas by late Sunday evening, and most areas should be dry overnight into Monday. A potent late-season storm across California will continue to move east throughout the day Monday, and by midnight Tuesday the center of the storm should be across the Utah/Colorado border. Ahead of the trough strong southwest flow will continue over our area both aloft and at the surface, resulting in another warm afternoon Monday, with convective chances confined to the eastern San Juans and Sangre De Cristos. Across the plains low-level moisture will be pushed well east into Kansas so we do not expect any repeat of Saturday/Sunday`s severe weather. On Tuesday the trough moves across northern Colorado and into Nebraska by Tuesday afternoon. Despite decent QG forcing throughout the day, our area looks to be dry slotted, especially across the plains. The trough does advect cooler air aloft, so despite the dry low-levels, diurnal convection is possible across El Paso County and across the mountains, with the primary impacts lightning and gusty winds. Instability overall should be limited. Late Tuesday into Wednesday as the trough moves further northeast our area is under northwest flow. The ejecting surface low across the central plains drags a cold front across eastern Colorado late Tuesday, and it should clear our area early Wednesday. The post frontal air is seasonably cool, and there is a fair amount of cold advection at 700 mb throughout the day, resulting in below normal highs for Wednesday. The COS metro area should struggle to reach 60 degrees and the plains only in the mid to upper 60s. The plains should remain dry behind the front, while once again with good cooling aloft the mountains could see isolated showers during the afternoon, with the best chances from the eastern San Juans/La Garitas to the upper Arkansas Basin. For Thursday and Friday yet another trough is positioned upstream across the Great Basin, resulting in southwest flow aloft and a continuation of afternoon thunderstorms across the mountains. 700 mb temps warm a bit on Thursday, then another warm another 4-6 degC on Friday, resulting a nice warming trend at the surface and a return to more seasonable temperatures, even above normal by Friday with mid 80s across the southeast plains. Enough low level moisture should be in place across the plains for some of the afternoon storms to survive the trek east out of the mountains and off the Palmer Divide and Raton Mesa. Will keep low PoPs in place to account for this each afternoon/evening. Instability remains fairly limited so main impacts would be gusty winds and some lightning. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 316 PM MDT Sat May 25 2019 Quiet weather expected across the terminals through Sunday evening, with VFR conditions expected and no precipitation. High resolution models develop some fog along the east side of the Palmer Divide, and early runs brought the fog into the COS metro area, perhaps as far west as the airport. However, recent trends have backed off so will remove the TEMPO group for fog. Evening shifts will watch the trends, especially if convection to the east can send a gustfront west up the slope of the Palmer Divide which would increase the coverage and westward push of any fog that develops. Otherwise expect drainage winds through mid morning and no aviation impacts. By Sunday afternoon southeast to south winds will once again increase at PUB and COS, gusting 20-25 kts. At ALS expect similar afternoon winds as Saturday, with southwest winds gusting 25 kts or so. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MOORE SHORT TERM...SCHLATTER LONG TERM...SCHLATTER AVIATION...SCHLATTER