Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/23/21

Area Forecast Discussion
National Weather Service Denver/Boulder CO
941 PM MDT Tue Jun 22 2021 .UPDATE... Issued at 932 PM MDT Tue Jun 22 2021 No big changes this evening. Made some adjustments to smoke coverage as the Muddy Slide fire near Yampa and the Oil Springs fire south of Rangely are the big smoke producers this evening. Those plumes will come over Boulder and Denver, favoring the north side of the metro area, overnight. How much smoke we see in the morning will largely depend on how long the plume dominated fire behavior goes during the night. The plumes should be diminishing and drifting east by morning, again with most of the smoke staying aloft. The area that could have a lot of low level smoke would be the valleys of Grand county (and areas near the fire in Routt county too). && .SHORT TERM...(This evening through Wednesday) Issued at 236 PM MDT Tue Jun 22 2021 RAP analysis this afternoon shows the upper level ridge continuing to build across the area. There`s a little embedded moisture aloft which has led to some scattered cloud cover across the higher terrain, though we`re still cloud free across most of the plains. Temperatures in the low 90s are common across the plains and in the 80s for the Foothills and high valleys. Winds have increased a tad over the plains but a more notable pickup in gusts has been noted over Middle and North Park. Red Flag conditions will likely continue into the early evening hours tonight before winds decouple and humidity increases. Tonight should be fairly quiet and mild for the Denver metro, with lows in the upper 50s to low 60s. Cloud cover should gradually decrease overnight tonight as surface temperatures cool. Hot and dry weather will continue for Wednesday with 700mb temperatures near 18-19C along with light downslope winds through the day. Forecast highs are a couple degrees warmer than today, with plenty of mid to upper 90s across the plains. The only wildcard tomorrow will be the potential for high cloud cover and/or smoke, but for now I`m not convinced this will be enough to keep us "cool" in the afternoon. Models do show some very weak instability in the afternoon as well, with at least a slight chance of thunderstorms for the southern Foothills and South Park. Almost no moisture to work with, so rainfall amounts would be minimal. The main concern will continue to be elevated and critical fire danger across Middle and North Park, where Fire Weather Watches remain in effect. Smoke could also be an issue during the day with generally westerly flow aloft, which should advect smoke into the area either tonight or tomorrow morning. HRRR Smoke forecasts continue to bring in a decent area of smoke aloft, but this will be highly dependent on how the ongoing fires behave this evening. .LONG TERM...(Wednesday night through Tuesday) Issued at 236 PM MDT Tue Jun 22 2021 On Wednesday night into Thursday, models are showing the upper ridging to push south and eastward away from Colorado as weak upper troughing develops over the western United States. Troughing is in place over the CWA Friday and Friday night. The QG Omega fields show weak upward vertical velocity in place over the forecast area Wednesday night through Friday. In the lower levels, a cold front is expected to push across the area Thursday afternoon then another, more significant one, on Friday. Moisture is progged to increase over the forecast area with the upper troughing. Precipitable water value progs range from 0.80- 1.20 inches for the plains to 0.50-0.90 inch in the mountains Thursday through Friday night. There is fairly decent CAPE noted on Thursday into Friday, with the highest amounts over the northeast corner late in the day. There could be some severe weather there around 00Z Friday; mainly hail and wind. Some areas could see decent rainfall Thursday into Friday. Later Friday and Friday night, the precipitation could be more stratiform in nature behind the front. Temperatures should be around seasonal normals on Thursday, then well below on Friday. That will continue for the later periods with cooler than normal readings Saturday through Monday. Tuesday`s highs look to be near normals. So no 90s F plus temperatures are expected for Denver Thursday through Tuesday. Weather-wise, in the extended period, Saturday through Tuesday, upper troughing is in place Saturday, then northerly flow aloft Sunday into Monday. Upper ridging gets back over us by Tuesday. Saturday still looks like some rainfall is possible. Sunday and Monday are pretty dry, with Tuesday looking like no precipitation will fall at all. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 932 PM MDT Tue Jun 22 2021 Wildfire smoke plumes will be over the Denver area again tonight, but little impact on surface visibility is expected. This smoke will likely diminish Wednesday morning with new plumes developing mainly southwest through northwest of Denver Wednesday afternoon. The smoke layers and poor slant visibility may affect KDEN approaches, mainly before 12z Wednesday and again after 22z. No other weather impacts are expected with only isolated high based showers Wednesday afternoon. && .FIRE WEATHER... Issued at 236 PM MDT Tue Jun 22 2021 Critical fire danger will continue into the early evening hours across North and Middle Park, but conditions will quickly ease through the evening hours. Near-critical or critical fire danger is likely again tomorrow across the same areas with RH near 10-15%. There are two factors that limit confidence in meeting criteria - (1) the potential for smoke and high cloud cover limiting heating, and (2) weaker boundary layer winds. Due to these concerns we`ll hold off on making a decision for the Fire Weather Watch. A cooler, more moist airmass should be in place over all the forecast area Thursday into the weekend; critical fire danger is not expected. && .HYDROLOGY... Issued at 236 PM MDT Tue Jun 22 2021 No hydro concerns tonight and tomorrow. There is a slight chance of thunderstorms tomorrow afternoon, mainly for the southern Foothills and South Park. Any rainfall from storms would be very light. Some areas of heavy rainfall are possible across the northeastern corner of the CWA Thursday afternoon and evening. The burn scars in the foothills could also see brief heavy rainfall Thursday, Friday and Saturday afternoon and evening. && .BOU WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch from Wednesday morning through Wednesday evening for COZ211-213-217. && $$ UPDATE...Gimmestad SHORT TERM.....Hiris LONG TERM......RJK AVIATION...Gimmestad FIRE WEATHER...Hiris/RJK HYDROLOGY......Hiris/RJK
Area Forecast Discussion
National Weather Service Grand Forks ND
1030 PM CDT Tue Jun 22 2021 .UPDATE... Issued at 1026 PM CDT Tue Jun 22 2021 Southwesterly winds are beginning to subside this evening, and turn a bit more southerly as they decrease in magnitude. There is an increase in mid-level moisture across southern MN and into north central MN, and will adjust skies if needed although I did bump up coverage on the 7 PM update. One change will be to add a brief period where a shower or elevated cell may develop along the intl border. A H850 LLJ develops around midnight in western ND and increases in intensity as it approaches SE MB...with HRRR showing 50+ kts across far SE MN and LOW around 12Z. HRRRTL and ARW guidance POPs best aligned with when nose of the jet moves into SE MB, so used that blend for timing, but the best increase in intensity is as the LLJ moves into western Ontario. Would think somewhere across SE MB and along our MN/MB border a shower could easily develop, especially across LOW near sunrise. UPDATE Issued at 637 PM CDT Tue Jun 22 2021 Southwest winds to continue tonight and actually pick up after midnight, mainly across eastern North Dakota. The late night mixing will keep overnight lows near sixty across the Devils Lake basing while west central MN sites will drop into the lower 50s. Did increase cloud cover for mid/high cloud over Sask/MB that will translate across area tonight as NW flow aloft continues. && .SHORT TERM...(This evening through Wednesday night) Issued at 305 PM CDT Tue Jun 22 2021 Impacts are not expected through the remainder of today into the evening and overnight. Low temperatures will fall into the middle 50s to near 60 degrees. Looking into Thursday morning, cloud cover increases early for areas north of hwy 2. Areas to the south will see sunny skies through at least midday. H5 thermal ridging allows temperatures to climb sharply with highs expected to soar into the middle 90s, with perhaps upper 90s for the southern Red River Valley. A cold front pushes through the area during Wednesday evening, bringing a chance for showers and thunderstorms to the region. There is a marginal chance for severe thunderstorms, primarily for northwest and north-central Minnesota, as well as the northern Red River Valley. Soundings indicate CAPE as high as 1500 J/Kg, as well as favorable deep layer shear. As such, we are looking at the potential for damaging wind gusts and hail upwards of one inch. We could see impactful weather through the evening in association with these thunderstorms. .LONG TERM...(Thursday through Tuesday) Issued at 305 PM CDT Tue Jun 22 2021 Impacts throughout the long term period will be tethered to the potential for showers and thunderstorms during the late week period and into weekend with shortwaves progressing through northwesterly flow aloft. A drier air mass is then expected to settle in moving into next week with temperatures warming from near normal over the weekend back to above normal by early next week. Thursday through Sunday... As an upper level ridge builds in over the western CONUS, induced northwesterly flow aloft is expected across the northern Plains. This flow pattern will be conducive to increased shortwave potential moving into the late week and weekend period. An interesting setup is being depicted within ensemble guidance for Thursday as a split flow pattern over the Plains looks to introduce a primary shortwave from the northwest and secondary wave moving in from the south. This will in turn bring about the potential for some fairly widespread light rain to the area late Thursday into Friday. There are still some ensemble discrepancies with regards to the magnitude of precipitation potential, but overall confidence is increasing in this system. Moving into the weekend, the potential is there for a shortwave or two to ride the northwesterly flow into the area, but confidence at this time is low. Otherwise, temperatures look to remain relatively steady in the upper 70s to 80s for the weekend. Next week... The upper level ridge over the western CONUS is progged to slowly travel eastward by the early week period. Cluster analysis generally agrees on this solution, although the exact magnitude and eastern extent of the ridge within guidance is the main question mark at this time. Regardless, this will effectively stymie precipitation potential while also introducing a warming trend for the week ahead. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1026 PM CDT Tue Jun 22 2021 There is increasing confidence for a period of LLWS tonight as a LLJ ramps up across western ND and turns more southwesterly as it flows along the border and into southeastern MB. Should mainly impact DVL/GFK/TVF and bumpy conditions can be expected north of Hwy 200 (see for official low level turbulence charts). Strongest 850 mb winds should across the northern valley and northwestern MN. For the last six hours of this TAF period, will see increasing chances for TS across NW MN (TVF/BJI) tomorrow evening. Other than LLWS tonight and TS potential tomorrow eve, CAVOK throughout TAF period. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. $$ UPDATE...Speicher SHORT TERM...Lynch LONG TERM...Rick AVIATION...Speicher
National Weather Service Sioux Falls SD
707 PM CDT Tue Jun 22 2021 .SHORT TERM...(This Evening through Wednesday) Issued at 233 PM CDT Tue Jun 22 2021 Mid afternoon objective analysis shows a relatively stationary boundary roughly draped along the SD/NE border eastward toward Le Mars and eventually southeastward toward Storm Lake. Along and south of it, a notable agitated Cu field has developed along with festering weak convection. Biggest question regarding today`s convection continues to be the quality and depth of moisture and thus the resultant instability. Surface obs across the region show dewpoints largely in the mid to upper 50s with some pooling of moisture noted along the front with a few lower 60 dewpoints. This has resulted in 500-1000 J/kg of MLCAPE via RAP mesoanalysis. Should established deep convection result, effective shear around or in excess of 45 kts will be more than sufficient for rotating updrafts. High res CAMs in decent agreement for more robust convective development in the 3-5 pm time frame just a bit north of Hwy 20 with Bunkers RM vectors taking storms quickly off to the south/southeast. With relatively straight and enlarged hodographs in the mid to upper levels, may see a tendency for a few cell splits as well. Despite the rather skinny and meager instability profiles, this enhanced deep layer shear may compensate to allow for a hail report up to ping pong ball size and damaging wind up to 60 mph. While the presence of a boundary would typically spark some tornado concern, LCLs likely too high for a higher concern with regards to that. Any severe potential would likely be confined to prior to 8 pm with perhaps some lingering elevated convection through the remainder of the evening. Otherwise, quiet overnight period expected with some hint at fog or lower stratus late tonight into Wednesday morning, given the dry ambient conditions and lack of support by SREF probabilities, not sold on this idea just yet. A very warm day for Wednesday as 850 mb temperatures warm into the upper 10th percentile of climatology. Would expect widespread 90s for afternoon highs with a few locations near and west of the James River perhaps exceeding the century mark. Dewpoints won`t be overly oppressive so any Heat Advisory criteria may be a bit more localized and thus have opted against an advisory. Mid level lapse rates will also begin to steepen through the afternoon and evening Wednesday with a wave likely sparking at least isolated to scattered convection over the High Plains. Guidance in fair agreement with taking this convection eastward through the evening and early overnight hours with consensus for any stronger activity to remain south of the MO River. With this said, not impossible to get a stronger wind gust into our MO River counties with forecast soundings showing a strong inverted V characteristic. This is covered by a Marginal Risk from SPC. .LONG TERM...(Wednesday Night through Tuesday) Issued at 233 PM CDT Tue Jun 22 2021 Thursday forecast remains a question mark with a strong dependence on any convective evolution from Wednesday night and the eventual placement of the synoptic boundary for the daytime hours Thursday. Along and ahead of this boundary, moderate to perhaps strong instability will remain in place and while deep layer effective shear may be somewhat limited, will continue to carry a strong/severe thunderstorm risk. SPC has highlighted the southeast half of our coverage area in a Marginal/Slight which seems like a reasonable start and will likely evolve as higher confidence in boundary placement occurs. Currently, NW IA and surrounding areas likely carry the highest precipitation and severe weather potential. Temperatures Thursday also in flux but roughly mid 80s to lower 90s seem reasonable for now. Upper level troughing carves in for Friday with some continued precipitation chances. Still some model discrepancy on where this trough axis sets up but some pairing from the GFS/ECMWF for a favorable placement for our area for occasional bouts of precipitation through the weekend. This will also keep temperatures near or below normal. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 705 PM CDT Tue Jun 22 2021 Scattered thunderstorms will continue around the KSUX area over the next couple of hours, but should be mainly north/east of KSUX. Otherwise, will continue VFR through 00z Thu. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...Kalin LONG TERM...Kalin AVIATION...Chapman
Area Forecast Discussion
National Weather Service Wilmington NC
721 PM EDT Tue Jun 22 2021 .SYNOPSIS... A cold front will sweep across the area tonight, accompanied by some showers and thunderstorms. Cool and dry high pressure will build in from the north Wednesday into Thursday with below normal temperatures. The lingering front offshore will move inland on Friday with increasing warmth and chances of showers or thunderstorms increasing through the weekend. && .UPDATE... The line of convection along the front is moving through Elizabethtown, Dillon, and Darlington currently and should be in Wilmington, Whiteville, and Florence in just a couple hours. I`m keeping PoPs in the 60-80 percent range across the area. The HRRR shows the line breaking up as it dips farther south toward Myrtle Beach and Georgetown overnight due to the cooling boundary layer, but I`m maintaining 30-50 PoPs even here given the good convergence continuing along the front. Low level cold advection behind the front could generate a layer of low stratus late tonight into Wednesday morning. Changes this update mainly centered on PoPs, weather, and clouds. No changes to forecast low temps. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... Moisture rich environment ahead of approaching cold front this afternoon, with pcp water values up over 2 inches, but lacking in the sfc heating with such extensive cloud cover and shower activity. The front was draped from SW to NE across the Raleigh area around 3pm this aftn, evident by a line of convection. Overall, expect best potential for stronger storm development associated with lift along the front and enhanced by shortwave energy rotating around main mid to upper trough into early this evening. Increasing low level winds up to 45 kts with mainly unidirectional shear out of the SW will help to create limited potential for damaging wind gusts with the convection through this evening. Convection will weaken and diminish as heating of the day cuts off, tapering off once front moves through and winds shift from SW to N-NE. SPC keeps our local area in marginal risk of severe weather through this evening with a few strong to severe storms possible, with main threat of damaging wind gusts. Cold front will drop into the area between 10p and midnight, clearing the coast by daybreak. Lingering moisture and clouds should move off the coast through Wed morning as sfc high builds down from the north, but mid to upper trough will flatten out and lift north leaving front lingering in the offshore waters as high pressure builds down from the north. Winds will shift around from SW to NE as front moves through. Soundings and moisture profiles show deep drying through the column with some lingering low level moisture which dries out by Wed aftn, drying out further into Wed night. Pcp water values drop from 1.6 inches before daybreak Wed down less than an inch by midnight and possibly down to a half inch by Thurs morning. Overall, expect clearing skies and increasing sunshine through Wed with relatively cool and dry air keeping temps near 80, over 5 to 10 degrees below normal. Overnight lows will be closer to normal tonight, but by Thurs morning, lows will drop down near 60 inland. Should see some fog around inland but as dewpoints drop, any fog should clear into the morning. Dewpoint temps close to 70 this evening will be down in the 50s by Wed night. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... A weakening wedge of surface high pressure will be in place through the period. Models have trended much drier with the forecast, now suppressing the measurable rain offshore, a trend we were starting yesterday. Clouds may linger along the coast however while inland locales see breaks of sunshine. This will likely suppress highs by a few degrees below their inland counterparts; both inland and coastal locations remaining below climatology. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Weak flow aloft on Friday while a weak warm front/trough moves ashore. Morning showers along the coast will spread inland along with the boundary. With highs still only in the lower 80s instability may be meager enough for only isolated thunder. Fairly deep but weak onshore flow becomes established Saturday which should wind up fairly seasonable and with just a slightly elevated coverage of mainly diurnal storms. The deep onshore flow remains Sunday but subtle height rises from the northeast should tend to trim convective coverage back to normal (30 percent-ish). The upper level ridge to our northeast strengthens further Monday into Tuesday. The deep layer onshore flow will thus continue and keep the area susceptible to diurnal showers and isolated thunderstorms as the deep layer of marine air contains only very weak lapse rates. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... A cold front moving across the eastern Carolinas tonight is outlined by convective showers and some embedded thunderstorms. This activity should move southeastward this evening, affecting the FLO and ILM airports as early as 01-02z with the potential for lowered visibility and variable winds. Convective activity is expected to weaken later this evening as the line dips into the MYR/CRE vicinity after 04z, however visibility restrictions remain possible in moderate rain. Low stratus is expected to develop behind the front overnight with MVFR/IFR ceilings anticipated to overspread the area between 04-08z. Conditions may not improve until Wednesday afternoon in the ILM vicinity. Surface winds should become northeasterly behind the front overnight, with wind speeds increasing to 10-12 knots during the day Wednesday. Extended Outlook...Predominantly VFR Wednesday night through Friday morning. Convective showers and thunderstorms may return Friday through Sunday as the front moves back onshore && .MARINE... Through Wednesday night... SCA conditions will continue into tonight in gusty SW winds ahead of a cold front. SW wind speeds are 25 to 30 kt sustained. Expect the CFP to occur during the pre-dawn Wed hrs, sinking SE- ward to just offshore before stalling during Wed. Winds will back to the NE-ENE after FROPA and actually may be underdone by guidance. The post cold frontal NE surge will lie just below SCA thresholds but the seas will be slow to subside due to the stalled front in close proximity and the continued pseudo/fresh swell feed. SCA thresholds will be borderline during Wed, especially the waters off Cape Fear. Seas generally 5 to 8 ft at the start, subsiding to 3 to 5 ft at the end of the fcst period but subject to change especially toward the end. Potential SMW type convection by midday today and continuing into the evening with potential for 34+ kt wind gusts and occasional/frequent reduced vsby below 1nm at times from the heavy rain. Thursday through Sunday...E to NE winds Thursday as high pressure wedging in from the north starts to weaken/break down. Flow turns more southerly on Friday as the continuation of this process allows a warm front to move ashore. Over the weekend the gradient remains weaker than normal as Atlantic high pressure is displaced north and east of its more normal June position closer to Bermuda. The short period wind wave will dominate seas through the period but there will be a few longer period wave components, primarily out of the southeast. One will have a 7-8 second period and the other 12-13 seconds. && .TIDES/COASTAL FLOODING... Abnormally low tides, below -1 ft MLLW, will continue for the next several tide cycles as we approach the full moon on Thursday. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...High Rip Current Risk until 8 PM EDT this evening for SCZ054. Beach Hazards Statement until 8 PM EDT this evening for SCZ056. NC...High Rip Current Risk until 8 PM EDT this evening for NCZ106- 108-110. Beach Hazards Statement from 6 AM EDT Wednesday through Wednesday evening for NCZ106-108. MARINE...Small Craft Advisory until 1 AM EDT Wednesday for AMZ250-252- 254-256. && $$ SYNOPSIS...ILM UPDATE...TRA NEAR TERM...RGZ SHORT TERM...MBB LONG TERM...MBB AVIATION...43 MARINE...MBB/RGZ TIDES/COASTAL FLOODING...RGZ
Area Forecast Discussion
National Weather Service Lincoln IL
816 PM CDT Tue Jun 22 2021 .SYNOPSIS... Issued at 244 PM CDT Tue Jun 22 2021 A few showers or storms could affect areas north of a Canton to Bloomington line tonight, with drier conditions toward morning. Dry weather will prevail farther south. Strengthening south winds on Wednesday, will push high temperatures into the lower 80s. && .UPDATE... Issued at 814 PM CDT Tue Jun 22 2021 Light to moderate rain is moving into Galesburg and other areas north of the Illinois River Valley this hour. Further west, a few severe storms are noted, moving generally towards the south. Latest RAP shows instability gradient set up just to our west and not expected to shift east much at all this evening. Thus, precip should be in a diminishing state as it moves into the forecast area as it outruns the instability and encounters a more dry air mass per the 00Z KILX raob, which shows a deep layer of dry air in the lower and mid levels. Do not anticipate the stronger storms to move into the forecast area at this time. && .SHORT TERM...(This evening through Wednesday) ISSUED AT 244 PM CDT Tue Jun 22 2021 Early this afternoon high pressure stretched from Arkansas northeast through southeast IL and to the eastern Great Lakes. This brought pleasant early summer weather to the region today with plenty of sunshine and readings several degrees below normal in the low to mid 70s. Scattered showers and storms over western and central Iowa, associated with sheared shortwave in 500 mb NW flow and developing warm/moist advection aloft, will increase this evening as a 45 kt 925 mb jet strengthens from southern IA into western IL. This could bring a few strong storms to our west before weakening activity works across the northwest CWA this evening and overnight. Better low level moisture advection remains to the northwest, leaving conditions fairly dry below 800 mb this far east. A few thunderstorms could affect areas northwest of Peoria this evening, but primarily scattered showers expected as far south as a Canton to Bloomington line overnight. Light southeast return flow on the back side of the high will keep lows several degrees higher than last night, in the upper 50s to lower 60s (coolest south of I-70). A few showers will linger over the northern CWA into Wednesday morning, before the warm advection wing lifts northeast of the area. A tightening pressure gradient will result in breezy south winds, gusting up to 30 mph during the afternoon. This will push highs to more seasonable levels in the lower 80s. .LONG TERM...(Thursday through Tuesday) ISSUED AT 244 PM CDT Tue Jun 22 2021 Active weather looks to dominate the extended forecast, as a slowly amplifying upper trof tracks into the central U.S. for Thursday through the upcoming weekend. This pushes a cold front into the Midwest on Thursday, when the SPC day 3 outlook highlights a slight risk of severe storms just to our west. Marginal risk extends east through the IL River Valley, primarily for evening strong storm potential. Assuming most of the storms stay to our west thought the afternoon this would be the warmest day of the week with highs in the mid to upper 80s. While many details are unclear for Friday through Sunday, the general theme among the medium range models is that the front will be very slow to move across the region, as it becomes parallel to the mid level flow. This will result in periods of showers and thunderstorms. With the upper level jet aligned from the Plains into the Great Lakes, and very high precipitable water values near 2", severe storms and heavy rainfall will be a threat. Again hard to pin down details at this range in regards to severe wx, but QPF of 2-5" would bring in flooding concerns, primarily in areas that are repeatedly hit with heavy rain. Some signs the upper trof could close off across the upper Midwest early next week, keeping the unsettled weather pattern in place with lesser chances of heavy rain or severe storms. Highs should generally be in the 80s with 850 mb temps consistently in the upper teens C, though the humid airmass will trend lows above normal in the upper 60s to lower 70s. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 615 PM CDT Tue Jun 22 2021 South to southeast winds will prevail this evening and overnight, then winds will veer to the S/SSW and become gusty into the low to mid 20 kt range during the day Wednesday. A few spotty showers or storms are possible overnight, with the best chance of anything on station at PIA and BMI. The overall chance is low though as showers should decay as they encounter drier air in place over the state. Outside of any precip, VFR conditions will prevail. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Deubelbeiss SYNOPSIS...25 SHORT TERM...25 LONG TERM...25 AVIATION...Deubelbeiss
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
900 PM CDT Tue Jun 22 2021 .UPDATE... Issued at 900 PM CDT Tue Jun 22 2021 With the loss of daytime heating, thunderstorm chances across ncntl Nebraska appear to have diminished. A forecast update is in place for dry weather in this region and wrn Nebraska the rest of tonight. && .SHORT TERM...(This evening through Wednesday night) Issued at 342 PM CDT Tue Jun 22 2021 A weak disturbance is pushing across SD this afternoon. A weak surface low reflection is noted across far northeast portions of north central Nebraska to the north of O`Neill. A warm front extends east-southeast from the low across northeast NE and a trailing surface trough extends southwest across the southern Sandhills into the southern Panhandle. Most CAMS and the last few runs of the HRRR keep most of the convection focused east of the area near the warm front. There is some chance however that the initial development could occur across eastern Holt and Wheeler county in area of low- level convergence just east of the weak surface low. Overnight the low will weaken and dissipate with the training surface trough across the area washing out. Attention then turns to Wednesday afternoon. There are two main concerns Wednesday afternoon 1) hot temperatures and humidity and 2) thunderstorm development. First the hot temperatures. A plume of very warm air aloft with H7 temps around 17C and H85 temps of 27-31C will spread across the area. A surge of low-level Gulf moisture will also accompany the heat with dew points rising into the mid and perhaps upper 60s by late Wednesday afternoon along and east of Highway 83. The combination of heat and humidity will cause heat index values to reach into the 100-105 degree range. Will issue a heat advisory to cover the heat and humidity combo. Farther west the air will be much drier with heat index values in the mid 90s and will forgo headlines for these areas. As far as thunderstorm potential late Wednesday afternoon and evening...the very warm mid-level temperatures are a concern. Nevertheless a weak disturbance will approach the western High Plains during peak heating. Weak large scale lift ahead of this feature will probably lead to widely scattered thunderstorm development along a leeward surface trough within a well mixed and relatively dry boundary layer. A reservoir of very high CAPE will reside just to the east of the initial development due to increasing low-level moisture and very steep mid-level lapse rates. Within this area the NAM suggest SFC based CAPE values nearing 4000 J/KG and 30- 40 kts of 0-6km deep layer shear. Several HREF members grow the activity upscale as it moves east into the moist and unstable environment across northern Nebraska. This seems possible as a southerly low-level jet intensifies helping to maintain, but as mentioned very warm mid-level temperatures could limit coverage. As far as threats, the very steep mid-level lapse rates could enhance hail potential, and large temperature/dew point spreads could enhance wind potential (especially early on across western NE within a well mixed drier boundary layer). .LONG TERM...(Thursday through Tuesday) Issued at 342 PM CDT Tue Jun 22 2021 Upper level ridging will be replaced by long wave troughing that develops from central Canada through the Central Plains. This occurs as upper level ridging develops along both coasts. This will bring an increase in cloud cover as well as a chance for rainfall. Models have been struggling with this overall scenario and it is unclear how much precipitation may fall. More certain is that it will be cooler with highs generally in the 70s Friday and 70s to lower 80s Saturday into Sunday. Could locally be cooler if more precipitation materializes. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 643 PM CDT Tue Jun 22 2021 VFR conditions will prevail over the next 24 hours with mostly clear skies. Winds will remain light over the next 24 hours, generally out of the south to southwest. && .LBF WATCHES/WARNINGS/ADVISORIES... Heat Advisory from noon CDT /11 AM MDT/ to 8 PM CDT /7 PM MDT/ Wednesday for NEZ005>010-025>029-036>038-057>059-069>071. && $$ UPDATE...CDC SHORT TERM...Taylor LONG TERM...Taylor AVIATION...Gomez
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1020 PM CDT Tue Jun 22 2021 .UPDATE... 1020 PM CDT Modest adjustments to the going forecast tonight through Wednesday night, mainly to increase winds/gusts a bit from later tonight onward as Wednesday into Thursday look fairly breezy/windy. Also tweaked pops a bit through late evening, with best chances of showers/isolated thunderstorms largely after midnight even across our western counties. Low-amplitude short wave was evident tracking southeast across western IA this evening, with an associated enhancement of the more broad scale southwesterly low level flow across the central and southern Plains. Scattered thunderstorms which had formed this afternoon across central and eastern IA continue on the nose of a southwesterly 35 kt H8 jet, with a gradual weakening trend as cells propagate southeast into western IL and away from the better MUCAPE axis per RAP mesoanalysis data. This has kept the WFO LOT cwa fairly quiet through the evening, except for a few decaying light showers west of I-39. Expectation is that showers will later develop and expand in coverage eastward into northern IL as the low level jet veers into the area and the mid-level wave tracks to the east. Forecast soundings do indicate some weak elevated instability overnight, which will likely allow for some isolated/embedded thunder late tonight into early Wednesday though coverage should be limited (with scattered showers more widespread) and without a severe weather threat. Tweaked pops downward across the area through midnight, but maintained likelys late tonight into Wednesday morning based on these trends. Precip potential should diminish across the area by midday/early afternoon as increasing southwesterly flow lifts the elevated warm front north of the forecast area. As the 30-35 kt low level jet shifts across the are late tonight and Wednesday breezy conditions are expected to develop, especially from mid-morning on as diurnal warming deepens the mixed layer. Gusts around 30 mph are likely. Breezy conditions will likely continue Wednesday night and into Thursday as well, with strong southwest flow persisting above the boundary layer. Updated digital and text forecast products are available. Ratzer && .SHORT TERM... 317 PM CDT Through Wednesday night... It was another pleasant - cooler than normal - summer day today with highs in the lower to mid 70s with the local area under the surface ridge axis. Off and on warm advective showers are expected to push into the area overnight along the nose of the low-level jet, potentially aided by a weak mid-level disturbance. These showers are expected to expand in coverage overnight into Wednesday morning but should be rather intermittent, rather than raining all night and through the morning. There is a period where guidance shows a weak axis of MUCAPE moves overhead which would support at least mention of embedded thunder possible. The upper trough axis shifts off to the east on Wednesday with warmer air lifting back into the area behind the showers. This will allow temperatures to warm back into the lower 80s for most areas. This will also be aided by mixing down of gusty winds through the afternoon with gusts up to 25-30 mph possible. There could be a few isolated showers that linger into the afternoon period, but for now will maintain a dry forecast for that period. The strong low level jet remains overhead into Wednesday night which could allow for sporadic stronger gusts to persist into the evening and overnight hours. Petr && .LONG TERM... 333 PM CDT Thursday through Tuesday... Main long term forecast focus continues to be on thunderstorm chances and coverage Thursday into Saturday along with the potential for locally heavy rainfall and severe weather. Areas of convection are likely west and northwest of the cwa later Wednesday night into early Thursday morning. Guidance continues to indicate a minor amplitude short wave trough will ripple through westerly mid-level flow, while the nose of a southwesterly low level jet orients warm/moist advection into far northern IL/southern WI Thursday morning. This suggests at least some potential for upstream convection to work into especially north central IL and the IL/WI state line after sunrise Thursday, though perhaps in a decaying mode by that time. Confidence remains fairly low on evolution into the cwa, but chance pops continue to appear warranted for the northwest cwa Thursday. Its possible that precip chances will remain isolated/scattered Thursday afternoon/evening. Medium-range guidance is in reasonably good agreement in bringing another somewhat more amplified mid-level trough across the area late Thursday night into Friday, before a large upper trough digs across the upper Midwest and Great Lakes region into the weekend. A pair of surface lows accompany these upper features, which slowly trail a surface cold front into the area Friday night through Sunday. Some timing/locations differences remain, which along with any modulation of MCS outflow boundaries and effects on instability during the the period, but strong, possibly severe thunderstorms are certainly possible. In addition, precipitable water values approach 2 inches on Thursday but on Friday with lower 70s dewpoints, possible mid 70s dewpoints pooling along the frontal boundary, precipitable water values push into the 2 to 2.30 inch range. Thus, torrential rain and localized flooding would be possible. Model qpf amounts vary quite a bit regarding the placement of the heaviest axis, but in general, the models are showing the potential for several inches of rain nearby. High pops from the blended guidance still look fine for this time period. With the upper trough expected to be over the region through at least early next week, possibly closing off as an upper low for a time as the ECMWF and GEM are indicating, at least chance pops are needed for the rest of the extended period. Its likely that as these time periods approach, pops can be trimmed at night with mainly diurnally driven activity but too early for that detail yet. And the front may be strong enough to clear precip from the area for part of the time this weekend. Better moisture and frontal focus moves east/southeast of the area into early next week, though upper low wobbling in the vicinity as indicated in EC/GEM solutions may warrant at least some chance pops into Monday/Tuesday. cms/Ratzer Ratzer && .AVIATION... For the 00Z TAFs... Aviation Forecast Concerns: * Showers and perhaps an isolated thunderstorm or two developing late tonight and persisting into Wednesday morning. * South-southwest winds become somewhat gusty late tonight and more so Wednesday, with gusts near 30 kts possible Wednesday afternoon. * Breezy conditions persist Wednesday evening, maintaining some degree of surface gusts. 40-45 kt low level jet will result in LLWS potential especially if surface gusts remain on the lower side. A mid-level disturbance digging southeast from the upper Missouri Valley was inducing south-southwesterly return flow west of the Mississippi River late this afternoon. The resulting low level jet was producing elevated showers and thunderstorms within the region of moist ascent focused across IA early this evening. This activity is expected to develop east-southeast into parts of northern IL later this evening, with showers and a few isolated thunderstorms persisting through Wednesday morning as the low level axis shifts east. The best chance of thunderstorms is expected to remain mainly to the west and southwest of the terminals during this period, though an isolated thunderstorm can`t be ruled out especially early Wednesday morning. KRFD may have the best potential for isolated thunder, and have included a tempo mention there later tonight. It does appear that a period of scattered showers will affect the terminals however. Cloud bases and prevailing visibilities are expected to remain VFR. Light winds will back south-southwest this evening, and will increase a bit overnight as warm advection strengthens. Some gusts around 20 kts are possible late despite the nocturnally stabilized boundary layer as flow increases aloft. Southwest winds will increase Wednesday, with gusts around 30 kt possible by afternoon as the surface pressure gradient tightens and 850 mb flow increases into the 30-35 kt range. Winds will likely remain somewhat gusty even after sunset Wednesday night, though some potential for LLWS will exist as the low level jet increases to 40-45 kts. Ratzer && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Small Craft Advisory...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744- LMZ745...7 AM Wednesday to 10 PM Thursday. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Pendleton OR
754 PM PDT Tue Jun 22 2021 .UPDATE...The latest radar was showing showers and thunderstorms mostly over se Oregon with another area over central Oregon near rdm. At first the hrr and rap models did not handle the area of pcpn around central Oregon as well and have expanded area of thunderstorms for this evening. Otherwise these models have come into better agreement and bring the pcpn over se Oregon further north into portions of the Blue Mountains and Union/Wallowa counties before lessening toward morning and the forecast has been updated to reflect this. Other than some changes to sky and pops and pcpn amounts the present short term forecast appears on track. Further ahead into the extended forecast it appears our area of south central Washington and North Central Oregon will be under a strong high pressure system by this weekend. The current models were indicating a very warm...and hot temperatures and the confidence in the forecast is increasing. Therefore stay informed by listening to NOAA weather media for possible later statements regarding this potentially extreme hot temperature event. && .PREV DISCUSSION... /issued 454 PM PDT Tue Jun 22 2021/ SHORT TERM...Tonight through Thursday night...Upper low off of California coast and southwest flow over the region has brought increased moisture over the area. As several shortwaves move through the flow, the region, especially Central and eastern Oregon have been primed for thunderstorm development. However, satellite imagery continues to show abundant cloud cover over a good portion of eastern Oregon, with the Bend/Redmond area just breaking out and these clouds clearly have inhibited thunderstorm development. Latest radar shows a few showers across the central and eastern Oregon highlands. There are occasional lightning strikes but not much has gotten going. As the afternoon progresses and temperatures warm, will thunderstorms begin to initiate across areas where clouds break. The guidance differs on this, but there is obvious support for some development. Whatever showers and thunderstorms do develop this afternoon and evening will come to an end overnight. Additional development is expected on Wednesday, though likely with less areal coverage with rising heights. RH values will be lower on Wednesday and winds will be similar to today. Also expect less cloud cover temps will be similar if not a tad warmer. Therefore, extended the red flag warning through Wednesday evening for a combination of RH, wind and thunderstorms. Its possible winds across the Basin may necessitate the RFW be extended further north, but at this time it is marginal and thunderstorms are not expected in the Basin. Once we get past Wednesday, precip chances end, and winds will decrease but it remains dry and increasingly hot for the foreseeable future. High temperatures will range from the upper 80s to the upper 90s in the Basin on Wednesday. Highs Thursday will be a similar though perhaps a couple degrees cooler in the Basin. Overnight lows will be in the 50s and 60s. LONG TERM...Friday through Wednesday...The main story and concern in the extended period will be the intense heat wave that is expected to begin on Friday, and increase in intensity on Saturday through the beginning of next week. All of the longer range models and their ensembles are in good agreement in the development of a large and strong upper high pressure system over the PacNW, which will persist through the weekend into at least early next week. At this time, these deterministic models and their ensembles, as well as the NBM, are indicating that the hottest days will be Saturday - Monday, with record temperatures (both record high maximums and record high minimums) expected. After several days of the models advertising this intense heat wave, with little change in trend, confidence is high that this will occur. The GFS deterministic model and the GEFS (GFS ensemble) was originally the hottest, but now the new ECMWF and Canadian models have come in line with the GFS/GEFS forecast values. If the upper end of the range of possible temperatures by the models pan out, then we are looking at all time record high temperatures for many or most areas of the CWA. However, the more realistic values of the NBM 1D Viewer temperature forecasts would still bring record heat, but perhaps not all time record highs. However, cannot rule out the upper end forecast values by both the deterministic and ensembles since they are all in much better agreement with each other now with 850 mb temperatures rising into the lower to mid 30s deg C at 850 mb by Sunday and Monday. If this does actually occur, the Pendleton Airport, for example, would reach temperatures in the neighborhood of 115 degree F, which would be an all time record high temperature. The previous all time high was 113, which was set in August, rather than June, which makes this possible scenario even more significant. For now, will go with the more realistic NBM forecast temperature values based on climatology and the lower likelihood of seeing temperatures in the upper end of the probabilistic range of high temperature values by both the NBM and the resultant max temperatures by using the forecast 850 mb temperatures in both the deterministic and ensemble forecasts. This will bring the Pendleton Airport to a maximum reading of 110 deg F on Monday as the hottest day, which has occurred, or nearly occurred, several times in the last 25 years. In any case, an Excessive Heat Watch will be in effect from Friday afternoon through at least Tuesday evening, and this will be issued this afternoon`s forecast package. There is some hit of a weak shortwave trough topping over the high pressure ridge sometime early next week, which would cause possible afternoon/evening thunderstorms, which would likely be high based and mostly dry. Confidence is low on this occurrence, so will keep the entire extended period dry with no precipitation expected for now. Winds, for the most part, will be light, except for the usual locally breezy areas in the afternoons and evenings, mainly along the Cascades gaps, passes, eastern valleys, the eastern Columbia River Gorge, and the Lower Columbia Basin. The winds will also largely depend on where the position of the surface thermally induce low pressure trough will be located each day during this heat wave, especially wind direction. 88 AVIATION...Isold tsra will develop in and near taf sites krdm and kbdn that may produce lcl mvfr conditions with vsby and ceilings along with brief wind gusts to 30kts until 06z. Meanwhile taf sites kalw and kpdt may experience brief wind gusts to 30 kts through 04z and rain showers are possible. Otherwise the remainder of the taf sites should experience mainly vfr conditions for the next 24 hours. && .PRELIMINARY POINT TEMPS/POPS... PDT 62 94 59 92 / 10 0 0 0 ALW 67 97 63 92 / 10 0 0 0 PSC 65 99 62 96 / 0 0 0 0 YKM 63 97 62 96 / 0 0 0 0 HRI 66 98 62 96 / 10 0 0 0 ELN 64 89 62 90 / 0 0 0 0 RDM 52 91 50 91 / 20 20 10 0 LGD 55 91 52 86 / 40 10 10 0 GCD 57 90 57 89 / 20 20 10 0 DLS 63 91 62 92 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...Excessive Heat Watch from Friday afternoon through Tuesday evening for ORZ041-044-049-050-502-503-505>511. Red Flag Warning until 11 PM PDT Wednesday for ORZ611-640-642- 644-645. WA...Excessive Heat Watch from Friday afternoon through Tuesday evening for WAZ024-026>030-520-521. && $$ SHORT TERM...97 LONG TERM....99 AVIATION...97
Area Forecast Discussion
National Weather Service Tucson AZ
220 PM MST Tue Jun 22 2021 .SYNOPSIS...A moisture increase from the south will bring a chance of showers and a few thunderstorms to the area tonight and Wednesday. Thereafter, the heat will return for the upcoming weekend. The good news is that it will not be as hot or prolonged as the recent record breaking heat wave. This will be due, in part, to the increase in deeper moisture across the area starting early next week. This moisture increase will moderate temperatures a bit and result in the prospects of more areawide isolated to scattered showers and thunderstorms most of next week. && .DISCUSSION...Moisture will continue to increase across the area tonight into tomorrow with a chance of showers and a few thunderstorms in the forecast. Guidance from the UArizona WRF model and NOAA`s HRRR were in overall agreement with shower and some thunderstorm activity increasing tonight through Wednesday. The best chance for this activity will be around Tucson and Nogales westward. Thereafter, ensembles favored a drying trend as a more westerly flow aloft develops during the latter one-half of the week. This drying trend in combination with a ridge of high pressure aloft strengthening over the western United States will result in a brief period of hotter temperatures this weekend. The good news is that it won`t be as hot and prolonged as the most recent record breaking heat wave. This time the upper high becomes centered over the Pacific Northwest bringing excessive heat to that region. Farther south, though, this position of the upper high will eventually favor an influx of moisture from the east and southeast as a surface cold front dropping south through the Plains pushes westward into eastern AZ. The timing of this feature and subsequent moisture advection still remained somewhat uncertain but ensembles point to Sunday night or next Monday for the start. Once this moisture advances into eastern sections, daily shower and thunderstorm activity should be on the increase and spread farther west during the week. In a nutsell, the prospects of rain showers and thunderstorms will be on the increase next week. && .AVIATION...Valid through 24/00Z. SCT-BKN clouds 10-14k ft MSL into tomorrow with periods of isolated -SHRA/-TSRA, especially west of KTUS. Surface winds WLY/NWLY at 8-14 kts with a few gusts to near 25 kts both this afternoon and tomorrow afternoon. Winds decrease light and variable at other times. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A brief period of increased moisture will last through Wednesday, returning again Sunday into early next week resulting in scattered shower and thunderstorm activity. Any thunderstorms that do develop may result in gusty outflow winds up to 40 mph. Minimum relative humidity values will generally be in the 10-15 percent range in the valleys and 15-25 percent in the mountains. 20-ft winds will be less than 15 mph, with typical afternoon gustiness due to strong surface heating. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at