Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/19/24


Area Forecast Discussion
National Weather Service Denver/Boulder CO
929 PM MDT Tue Jun 18 2024 .KEY MESSAGES... - Cooler through Wednesday with scattered showers and a few storms. - Scattered thunderstorms Thursday into Friday - Turning hot and drier this weekend through early next week && .UPDATE... Issued at 925 PM MDT Tue Jun 18 2024 There are a few light showers around this evening that are not producing much in the way of rain or wind. These showers will eventually end around midnight. Late tonight and into tomorrow morning, there will likely be stratus that forms over much of the plains. This will keep conditions cloudy and cool for much of the day tomorrow. && .SHORT TERM /Through Wednesday/... Issued at 141 PM MDT Tue Jun 18 2024 Cooler temperatures have settled in across the forecast area today after a cold front swept through the region earlier this morning. As the troughing pattern continues over the western CONUS, there is a slight chance we get some weak rain showers or an isolated storm to develop over the higher terrain this afternoon. Current water vapor imagery indicates low level moisture is lacking at this time, but looking upstream, low and mid level moisture looks to be heading our way. The better chances for precipitation will be overnight tonight and tomorrow as the trough shifts eastward and a 90 kt jet will be in place to provide upper level support to northern CO. CAMs indicate banded precipitation spreading across the plains and continuing into tomorrow. Forecast soundings also show a dry to start moisture profile becoming increasingly saturated as low level flow will be from the southeast, allowing for moisture support from the Gulf. With the increasing moisture in place, some lower level stratus are expected to help keep Wednesday`s high temperatures on the cooler side. Temperatures are forecast to be 10-20 degrees below the norm and will likely struggle to reach the 70s across forecast area. && .LONG TERM /Wednesday night through Tuesday/... Issued at 230 PM MDT Tue Jun 18 2024 Models are in very good agreement overall with regard to the weather pattern. With more moisture and higher precipitable water values, scattered showers and a few storms will work their way eastward across the plains through tomorrow evening. Most of these should be ending by late evening in/near the mountains with some drying aloft noted, but linger over the eastern plains with low level 850-700 mb theta-e advection. For Thursday, the airmass should moisten a bit further across the area with deepening southerly flow. There are indications a little of this starts to peel off the easterly wave (broad circulation around Potential Tropical Cyclone One) in the western Gulf of Mexico. We`ll also be returning to warmer temperatures, which gives us more instability and probably an area of 1000-1500 J/kg MLCAPE over the northeast plains. Thus, a couple stronger storms would be possible, and perhaps an isolated pulse severe storm. By Friday, there`s a better chance some of this tropical moisture spreads northward across the forecast area and onto the western slope of Colorado. This would keep at least scattered shower and storm coverage in the forecast in/near the mountains, along with adding a threat of locally heavy rainfall. It appears an embedded shortwave could be arriving a little late for higher storm coverage, but something to keep an eye on for Friday afternoon and evening. For Saturday, the above shortwave will be passing to the east of Colorado, resulting in drying and subsidence through the weekend. Ensembles are in good agreement with that timing, and the subsequent mid level ridging over the Central Rockies and Great Basin into early next week. The combination of the ridge, drier airmass, and westerly flow aloft all supports a return of hot temperatures for the lower elevations, with mid and upper 90s expected for the plains and I-25 Corridor for Sunday, Monday, and Tuesday. There could still be enough moisture under the ridge for scattered mountain convection, and isolated storms on the plains each afternoon/early evening. But overall these would be high based with gusty winds and mainly light rainfall. Finally, depending on the fire intensity near Ruidoso, New Mexico (it is flaring up again this afternoon), the HRRR Smoke shows some smoke spreading across Colorado Thursday. && .AVIATION /00Z TAFS through 00Z Wednesday/... Issued at 541 PM MDT Tue Jun 18 2024 There will be a few showers in the vicinity of the terminals this evening but they are not expected to impact operations. Any ceilings that would form will be elevated and not significant. Winds will not be the typical drainage but will be ESE at DEN and APA. Late tonight and into tomorrow morning, there will be better moisture advected in from the east which may lead to status development. The limiting factor that could keep stratus away from the terminals would be the very dry air that is in place in this post-frontal airmass. But given pattern recognition, there is usually stratus that develops shortly after sunrise on setups like this and the stratus can last for the entire morning. The stratus will breakup around midday leading to some sunshine and gusty SE winds at DEN and APA. There will be showers and perhaps a couple thunderstorms tomorrow afternoon and evening. It is unlikely these would produce much of an impact as they will be elevated and likely won`t produce strong winds at the surface. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Danielson SHORT TERM...Bonner LONG TERM...Barjenbruch AVIATION...Danielson
Area Forecast Discussion
National Weather Service Billings MT
754 PM MDT Tue Jun 18 2024 .UPDATE... Rain continues at Baker, at the tail end of the wave departing to the northeast, and this precip will end by 03z. To the west, we are still seeing isolated to scattered showers in an area with steep lapse rates and hints of PV advection west of Billings. This activity may linger for a bit longer but overall it is dissipating slowly. Have made a few pop/wx adjustments, including the removal of TS for the duration of the night. The overnight will be chilly and dry with mid 30s to around 40F for lows most places. As previously noted, each of our climate stations has the potential to reach a daily record for June 19. The other issue tonight (remarkably for so close to the solstice) could be fog. HRRR is hinting at it in our east and along the Musselshell. That said, dewpt depressions are quite low, and in fact dewpts remain in the low-mid 40s in our east as of 745pm. With clearing skies and light winds, some valley fog seems plausible (we`ll give it a 20% chance for now). JKL && .DISCUSSION... Rest of Today through Thursday Night... Satellite and radar imagery showed an upper trough axis across eastern Montana with wrap around precipitation spilling into our central and western zones while the southeast corner of MT was being dry slotted. Precipitation coverage was greatest from Billings south and southwest into the foothills aided by upslope flow. The only lightning noted was in north central MT at this time. We may see a few isolated embedded lightning strikes over our northern tier zones through evening, with enough instability still out there to produce some groupel (Story, WY reported some) this afternoon. Otherwise, as the upper trough slowly exits to the Dakotas by evening we will see precipitation winding down. Some trailing energy in the SW flow may produce some lingering showers in our west until after midnight, but these should be hit and miss showers at best. For tonight, we should see partial clearing late. Overnight lows will be in the 30s to lower 40s. Our current forecast is for record lows... Forecast Low Record Low Billings 39 42 1946 Livingston 34 34 2007 Sheridan 34 36 1985 Miles City 37 41 2020 For Wednesday, relatively benign W/SW flow will mean mostly sunny skies. We may see a few showers/thunderstorms develop in our eastern border counties, as well as around the Belts and Snowies, but for the most part dry conditions will prevail. The pattern will favor a low level jet (850mb) developing Wednesday night which may result in persistent isolated showers along the eastern border counties overnight. Highs Wednesday will be in the upper 60s west to mid 70s east. Lows Wed night will be in the lower 40s west to around 50 east. Not much overall change for Thursday as southwest flow continues aloft. We may see a few showers develop over the mountains by midday, but more significantly, isolated showers and thunder developing in a low level convergent zone (Rosebud County vicinity) over the plains. MUCAPE may get over 500 J/kg in this area with a 90% chance of effective bulk shear over 35kts. Thus, a few strong storms are possible in the east Thursday afternoon and early evening, though not a severe risk for now. Highs Thursday will range from mid 70s west to lower 80s east. Showers could linger again Thursday night over the eastern plains. Lows will be in the 50s. BT Friday through Tuesday... Friday, the region will be ahead of Pacific troughing bringing increased chances for precipitation early Friday morning through Saturday morning. Models generally have forcing being the strongest over northern MT, but our region still has a good chance of getting at least a quarter inch of rain (50-70% Billings north and east). SE flow in the low levels will stream in warm air and moisture ahead of the frontal passage Friday night. PWATs will be around 0.8-1.3 inches (highest in the east). This will give way to good instability across the region and allow for thunderstorms to develop. Ridging will build in the latter half of Saturday through Sunday allowing for hot and dry conditions. Ensembles and clusters then bring in slight troughing or westerly flow late Monday into Tuesday, but generally keep most energy to the north keeping PoPs at 20% or lower. High temperatures will be in the 70s Friday, 70s/80s Saturday, 80s/mid 90s Sunday and 80s for Monday and Tuesday. TS && .AVIATION... Showers will begin to dissipate late this evening. Fog is likely to form after 06Z for SE MT (KMLS and KBHK) dropping conditions back down to MVFR/IFR. Fog is also possible for KBIL, but confidence is lower. Conditions will clear up after sunrise with VFR prevailing for most sites tomorrow. Mountain obscurations will continue through the evening. TS/LT && .PRELIMINARY POINT TEMP/POPS... Wed Thu Fri Sat Sun Mon Tue ----------------------------------------------------------- BIL 039/073 050/078 057/075 055/081 056/094 060/087 056/083 30/U 01/B 47/T 62/W 00/U 11/U 11/U LVM 034/071 041/075 049/077 049/082 051/091 054/086 049/082 41/U 01/B 37/T 51/U 01/U 11/N 11/U HDN 037/076 049/081 057/077 054/083 054/095 058/089 054/085 21/U 02/T 57/T 72/W 00/U 10/U 11/U MLS 037/074 051/078 057/074 055/078 054/092 061/086 056/082 21/U 12/T 57/T 73/W 10/U 10/U 21/U 4BQ 036/074 052/078 059/077 057/079 055/094 064/088 057/084 02/T 22/T 56/T 72/W 10/U 10/U 10/U BHK 035/072 050/075 054/072 054/077 051/089 059/087 053/083 32/T 22/T 57/T 73/W 10/U 10/U 21/U SHR 034/074 046/080 054/078 052/080 052/094 058/089 053/085 21/U 11/B 46/T 62/W 00/U 10/U 10/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$ weather.gov/billings
Area Forecast Discussion
National Weather Service Charleston SC
1054 PM EDT Tue Jun 18 2024 .SYNOPSIS... High pressure will extend across the region this week. A trough of low pressure will impact the Southeast U.S coast Thursday into Friday. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... A narrow band of light showers continues to track westward across portions of SE GA and adjacent waters as seen on KCLX radar. As we head into the night, the current showers are expected to dissipate before a second round of light showers arrive around sunrise. The KCHS 00Z sounding observed a strong inversion centered around 750 mb, beneath the inversion winds were E at 15 to 20 kt. Recent runs of HRRR indicated that low-level clouds will move westward over the coastal areas overnight. The strong observed inversion will likely trap moisture and will result in increasing cloud cover near the coastline. The forecast update included increasing cloud cover over portions of SE GA and the SC lowcountry. Also, slight adjustments were made to PoPs and weather. The latest run of the HRRR forecast soundings indicate that the strong 750 mb inversion through tomorrow and will result to little to no deep instability. The forecast update also included removing the thunderstorm potential for tomorrow. This is in line with SPC`s Day 2 Convective Outlook. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... Wednesday and Thursday: The southern flanks of the expansive upper level anticyclone centered over the eastern United States will begin to buckle just a bit as a well defined TUTT located north of the Greater Antilles approaches the Southeast U.S. coast. The operational GFS is has finally come in line with the rest of the global guidance in keep any surface reflection of the TUTT as an open tropical wave/inverted trough as it moves onshore late Thursday night into the day Friday. Given a modest northeast low-level flow is expected to continue ahead of the approaching tropical wave, steering trajectories favor coastal Georgia for the best chances for measurable rainfall. Still not seeing a strong QPF signal in the various guidance for any concentrated areas of showers given the development of deep convection seems unlikely with the degree of subsidence noted aloft, but isolated to scattered low-topped showers with a few tstms appear likely. Pops 20-40% were maintained for mainly the coastal counties, highest along the Georgia coast. Highs will warm into the upper 80s/lower 90s away from the coast both days with lows Thursday morning dropping into mid-upper 60s well inland to the mid-upper 70s at the beaches. Breezy to locally windy conditions will also persist along the immediate coast and beaches. Thursday Night and Friday: Rain chances will begin to ramp up late Thursday Night and especially Friday as the approaching tropical waves moves onshore. Shower coverage may lessen a bit Thursday evening as subsidence ahead of the tropical wave spread in from the east, but this will rapidly change as daybreak approaches Friday and the primary wave axis pushes inland. The wave will be accompanied by a ribbon of PWATS in excess of 2 inches. This coupled with some forcing with the weakening TUTT aloft and the convergent/east side of the westward propagating surface wave should be enough to support scattered if not numerous showers with a few tstms. Pops were trended up a bit to 40-60% (highest coast), but given the TUTT will likely be rapidly dampening as it approaches the expansive upper- level anticyclone, there is some hesitancy to go any higher with pops at this time. Further adjustments will likely be needed. Lows Thursday night will drop into the mid-upper 60s well inland to the mid-upper 70s at the beaches. Highs Friday will range from the upper 80s/lower 90s away from the coast with cooler conditions at the beaches. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... The tropical wave and associated TUTT aloft will quickly dissipate over the weekend with the region positioned along the eastern flanks of the large subtropical anticyclone. Despite the dissipation of the TUTT, a broad weakness looks to remain through early next week. This coupled with sea breeze influences and lingering deep-layered moisture featuring PWATS in excess of 2 inches will support scattered showers/tstms each day. The heat will also begin to build through the weekend and especially Monday with highs warming into lower-mid 90s Saturday with the mid-upper 90s into early next week. The warmest day looks to occur Monday where a few spots far inland could make a run for 100 before the onset of showers/tstms. Dewpoints do not look to really mix out during this period with heat indices expected to peak 100-103 Saturday, 102-105 Sunday and 105- 110 Monday, highest across the inland portions of the coastal counties. Heat Advisories could be needed at some point with Monday being the best day for reaching the Heat Advisory criteria of 108. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... 0Z TAFs: Terminals are forecast to remain VFR through the TAF period. The primary concern will be the timing of gusty east winds at each terminal. Based on MOS, gusts are forecast to return to 20-25kts by 14Z Wed. The gusty conditions are expected to remain through the rest of daylight hours on Wednesday. Extended Aviation Outlook: Brief flight restrictions are possible in afternoon showers/thunderstorms Wednesday and Thursday, especially at KSAV. Chances of flight restrictions increase at KCHS/KJZI/KSAV terminals Friday and Saturday with lesser chances Sunday. && .MARINE... Tonight: A large and strong ridge of high pressure will encompass the coastal waters, with a subtle inverted trough to form nearby. The pattern will favor an enhanced pressure gradient across local waters through the night, with easterly winds gusting upwards to 20- 25 kt. Favorable long duration onshore fetch will also allow seas to build across local waters, eventually peaking between 4-6 ft across nearshore waters and 5-7 ft across offshore Georgia waters. Small Craft Advisories will therefore be in effect for all local waters outside the CHS Harbor tonight, but a brief lull in winds is possible this evening before 6 ft seas arrive across nearshore waters around midnight. Wednesday through Saturday: Gusty northeast winds will persist into Friday as a tropical waves approaches from the east and a modest gradient persists over the coastal waters. Northeast winds will average 15-20 kt with gusts to 25 kt during this time. Seas will remain above 6 ft through Thursday night within 20 NM and into Friday evening for the waters 20-60 NM offshore. Small Craft Advisories are in effect for these waters. Seas look to peak 5-6 nearshore waters and 6-8 ft in the offshore waters, mainly on Thursday. Winds in the Charleston Harbor will be near advisory thresholds, but are expected to hold just sky. The need for an advisory there will be reevaluated Wednesday morning. Both winds and seas will begin to diminish Friday night into Monday. Rip Currents/High Surf: Tybee Island Ocean Rescue is flying double red flags at all Tybee Island beaches where a number of very strong, dangerous rip currents have been observed. The waters have been closed here as a result. Expect the risk for strong and dangerous rip currents to spread into all beaches Wednesday which will persist into Thursday. A high risk for rip currents is being highlighted for all beaches for both days. NWPS breaking wave guidance shows breakers reaching 3-5 ft along the beaches on Wednesday and Thursday, highest in the Folly Beach area. Given only spotty instances of 5 ft breakers are being depicted, the situation for Wednesday looks to marginal for a High Surf Advisory at this time. && .TIDES/COASTAL FLOODING... Surface high pressure will remain off the coast of New England with a tight pressure gradient and elevated winds across the South Carolina and Georgia coast. A full moon on 6/22 will also cause the astronomical tides to slowly build. There is a chance that minor coastal flood stage could be reach on the Wednesday and Thursday evening high tides for Charleston Harbor. Tides at Fort Pulaski are forecast to remain below minor flood stage. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...High Risk for Rip Currents through Wednesday evening for GAZ117-119- 139-141. SC...High Risk for Rip Currents from 8 AM EDT Wednesday through Wednesday evening for SCZ048>051. MARINE...Small Craft Advisory until 6 AM EDT Friday for AMZ350-352-354. Small Craft Advisory until 11 PM EDT Friday for AMZ374. && $$ NEAR TERM...ACD SHORT TERM...ST LONG TERM...ST AVIATION...NED/ST MARINE...DPB/ST
Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
632 PM CDT Tue Jun 18 2024 .KEY MESSAGES... - Hot and humid weather continues into next week. - Thunderstorms expected in NW MO overnight Tuesday into Wednesday, heightening flash flood concerns. - Rain possible again on Sunday (~40%), but predominantly dry next week. && .DISCUSSION... Issued at 430 PM CDT Tue Jun 18 2024 As has been the case for the past several days, hot and humid weather will continue to dominate the forecast. Highs will remain in the low/mid 90s, while lows will only drop to around 70. Diurnal cumulus is present across the area going into the afternoon, but shower/storm activity is not expected to occur with a lack of forcing at the lower levels to invigorate convective activity before sunset. Gusty southerly winds will diminish going into the evening. A surface low in the northern Great Plains and its associated cold front will bring a line of storms to NW MO overnight. These storms have already been observed on satellite/radar firing along the cold front. This cold front is expected to move into NW MO by Wednesday morning. Some CAMs are suggesting that the front will stall over NW MO. With this solution, more concentrated rainfall over NW MO may increase concerns for flash flooding. The HRRR, on the other hand, suggests a more transient frontal passage protruding further east into MO, which may limit the residency of rainfall in NW MO. In turn, this would expand coverage of showers and storms, minimizing flash flood concerns for NW MO. Current analysis between guidance and reality suggests that the HRRR has a better handle of the current storm activity out west, so more confidence can be placed in the timing of the HRRR forecast for storms later. However, as the event evolves, more concise evaluation can be given to intensity and location. All guidance suggests that there may be an isolated strong to severe storm or two overnight into early Wednesday morning, with primary threats being high winds and hail. Going into Wednesday afternoon, the presence of upper level divergence and embedded shortwaves could encourage additional rain showers across central MO. Following the cold front and associated rain, highs for Wednesday will fall slightly, remaining around the mid to upper 70s for far NW MO while areas towards central Missouri will continue to see highs hovering around 90. Unfortunately, though, this "reprieve" will not last into the following days. A ridge will build into the central CONUS on Thursday, bringing with it continued heat and humidity into Saturday. A shortwave trough ejecting from the west will bring back the chance for precipitation on Sunday (~40%), but higher probabilities remain towards the northeast. After Sunday, a ridge will build back into the area and keep conditions dry for the remainder of the forecast period. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 626 PM CDT Tue Jun 18 2024 An area of showers and storms will move into area this evening. This may bring periods of MVFR to IFR visibility and ceilings. It looks like showers and storms will be in the vicinity then for pretty much the remainder of the forecast as a front stalls in the area. With the front over the area, ceilings will likely (<60%) become MVFR with light winds prevailing. && .EAX WATCHES/WARNINGS/ADVISORIES... MO...None. KS...None. && $$ DISCUSSION...HB/Pesel AVIATION...CDB
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
327 PM PDT Tue Jun 18 2024 .SYNOPSIS...Dry weather is expected for the foreseeable future. Interior temperatures begin a slow warming trend through the work week with temperatures approaching 100 degrees in some interior valley locations Friday into Saturday. && .DISCUSSION...Dry weather conditions are expected persist through the foreseeable future as dry air remains in place within the mid- levels of the atmosphere over Northwest California. Visible satellite imagery shows cirrus (high-level) clouds spreading from northwest across the area this afternoon, while stratus near coastal Humboldt finally scatter out. Temperatures has been running 5 to 10 degrees warmer compared with yesterday`s reading as a weak high pressure builds over the area, with inland highs in the mid 70`s to mid 80`s. Tonight, stratus are expected to redeveloped around Humboldt Bay and vicinity. Light offshore flow is expected again tonight into Wednesday. Smoke from the Sites Fire in Colusa Co. is forecast to spread over Lake County overnight through Wednesday morning. HRRR smoke dispersion model indicates more waves of smoke from Sites Fire spreading form east-southeast on Thursday. Troughing the next couple days will keep temperatures over the interior near normal through Wednesday. By Thursday the trough will begin to break down and 850 mb temperatures will warm across the interior allowing some interior valleys to approach 100 degrees Friday into Saturday. This will bring a moderate heat risk for portions eastern Mendocino, Trinity and Lake counties. All while this is occurring, northerly winds and increasing low-level moisture at the coast will result in increasing chances of coastal stratus through the week with temperatures remaining near normal at coastal sites. Ensemble cluster analysis and deterministic models shows the high pressure flatten on Sunday as a upper-level trough moves toward the Pacific NW. An associated weak, dry cold front sweep east- southeast across Northern California. Thus, temperatures will moderate a few degrees across the interior late in the weekend into early next week but still remain several degrees above normal. /ZVS && .AVIATION...Stratus has been stubborn early this afternoon, but is slowly diminishing. All terminals this afternoon will be VFR, with NNW winds peaking at 15 to 20 knots. Winds are expected to diminishing by sunset. Tonight, stratus is expected to make a return and be more widespread than today`s. Stratus is expected to develop around Humboldt Bay and ACV, then advect north to CEC, bringing MVFR to IFR conditions. Stratus looks likely to stay offshore most the day Wednesday, but the coastal terminals could still be affected periodically. UKI is expected to stay VFR through Wednesday. JB && .MARINE...Northerlies will continue to ease into Wednesday. However, moderate to locally fresh northwesterlies persist over the outer waters. Afternoon fresh to locally strong northerlies are expected south of Cape Mendocino on Wednesday. Generally light gentle breeze is expected nearshore, with a period of southerlies north of Cape Mendocino tonight. Fresh breeze spread across the outer waters and early Thursday as a thermal trough develops inland, with locally strong winds downwind Cape Mendocino. Steep short period seas will continue to promote hazardous conditions for small craft primarily in the outer zones for the rest of the week. /ZVS && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 3 PM PDT Wednesday for PZZ455. Small Craft Advisory until 3 AM PDT Friday for PZZ470-475. && $$ Visit us at https://www.weather.gov/eureka Follow us on Facebook and Twitter at: https://www.facebook.com/NWSEureka https://www.twitter.com/NWSEureka For forecast zone information see the forecast zone map online: https://www.weather.gov/images/eka/zonemap.png
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
744 PM CDT Tue Jun 18 2024 .KEY MESSAGES... - Seasonably hot and humid weather will prevail this week. The hottest conditions will arrive Friday into Saturday when air temperatures climb into the middle to upper 90s and heat index values peak at 100-105 degrees. - Isolated thunderstorms will be possible from time to time over the next few days...with a better chance for thunderstorms arriving late Saturday into Sunday. && .UPDATE... Issued at 744 PM CDT Tue Jun 18 2024 Extensive cirrus shield remains in place across much of the forecast area, though is more sporadic across the Illinois River Valley. Rainfall has been next to non-existent so far, though a few showers are lifting northward toward the I-70 corridor in south central Illinois. Latest SPC mesoanalysis and HRRR forecast sounding for Effingham show some capping in this area, plus temperatures have been lower with the thicker cloud cover down there. Currently thinking thunder potential is minimal due to the weak instability, though a few showers remain possible in the eastern CWA through evening as a weak upper disturbance lifts northeast out of Missouri. Updated grids recently sent to reflect these thoughts, plus the usual minor tweaks to incorporate latest observational trends. Geelhart && .SHORT TERM...(Tonight through Wednesday Night) Issued at 329 PM CDT Tue Jun 18 2024 Deep-layer moisture continues to flow northward from the western Gulf of Mexico on the back side of a prominent upper high centered over the Carolinas. The corresponding thick cirrus shield has kept temperatures a few degrees cooler than they were yesterday and has limited instability. 20z/3pm satellite imagery shows mostly cloudy skies along/southeast of a Bloomington to Jacksonville line...with sunny skies to the northwest. Cannot rule out a stray shower or storm over the next couple of hours, but areal coverage will remain scant. CAMs are suggesting isolated showers may re-develop overnight across the Wabash River Valley...with showers/storms becoming a bit more numerous further west across Iowa/Missouri in association with a slowing cold front. Overall think most locations will remain dry as low temperatures only drop into the lower to middle 70s. The cold front will become stationary from Iowa into southern Wisconsin/northern Illinois on Wednesday. The strongest forcing and thus the greatest areal coverage of diurnal convection will remain focused just N/NW of the KILX CWA: however, the HRRR continues to suggest widely scattered convection along a pre-frontal trough perhaps as far south as I-72. Have therefore included slight chance PoPs as far S/SE as a Springfield to Paris line...but have focused better rain chances northwest of the Illinois River in closer proximity to the boundary. Otherwise Wednesday will be a hot and humid day with considerably less wind than has been experienced lately. S/SW winds will generally remain in the 10-15mph range as afternoon highs top out in the lower to middle 90s. Barnes .LONG TERM...(Thursday through Next Tuesday) Issued at 329 PM CDT Tue Jun 18 2024 As the upper high retrogrades westward and upper heights rise, rain chances will decrease and temperatures will increase by the end of the week. Latest guidance suggests the hottest period will be Friday and Saturday when high temperatures climb into the middle and perhaps upper 90s in a few spots. Corresponding heat index values will peak at 100-105 degrees...just shy of Heat Advisory Criteria. As has been advertised by the models for the past several runs, a significant short-wave trough is expected to traverse the country and push a cold front into central Illinois this weekend. 12z Jun 18 GFS and ECMWF are in relatively good agreement, showing the front arriving Saturday night. As a result, have included high chance to likely PoPs (40-60%) Saturday night into Sunday. Once the front departs, slightly cooler and less humid weather is expected early next week as highs drop back into the upper 80s to around 90 degrees by Monday. Barnes && .AVIATION... (For the 00z TAFs through 00z Wednesday Evening) Issued at 615 PM CDT Tue Jun 18 2024 VFR conditions expected the next 24 hours, with ceilings near or above 15,000 feet, primarily tonight. Gusty south winds will begin to diminish early this evening with loss of daytime heating. A gradual shift to the southwest is expected on Wednesday as a cold front approaches the Iowa/Illinois border, but speeds should be near or below 10 knots. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Indianapolis IN
957 PM EDT Tue Jun 18 2024 .KEY MESSAGES... - Extended period of hot and humid conditions through this weekend - Partly cloudy Tonight and Wednesday. - Stray Shower or Thunderstorm possible through Thursday. && .FORECAST UPDATE... No major changes needed to the ongoing forecast other than to cut the POPs in the near term through 09Z as it becomes more clear that precipitation has wrapped up. There will be another subtle surge of forcing towards daybreak which could produce an isolated shower towards daybreak but coverage is not expected to be more than isolated. Another mild night is expected with widespread cloud cover and low 70 dewpoints not allowing for much radiational cooling. Clouds may begin to clear towards the morning hours tomorrow, but think that the bulk of drier air aloft won`t arrive until later in the day. && .SHORT TERM (This evening through Wednesday)... Issued at 227 PM EDT Tue Jun 18 2024 Surface analysis early this afternoon shows a large area of high pressure in place just east of the middle Atlantic States. This was resulting in warm and humid southerly flow across Indiana and the Ohio Valley. Aloft, water vapor showed a strong ridge of high pressure over the United States east coast, while a moderate through was found over the western CONUS. Water vapor also showed a plume of tropical moisture streaming from the Gulf of Mexico across the Tennessee river Valley to Indiana, OH and MI. Radar this afternoon shows an area of showers under the plume over southern IL and SW Indiana. Surface winds were from the south and dew points were quite humid, in the lower 70s. Tonight... The upper high pressure system to the east is expected to begin to retrograde a bit west tonight. This will slowly start the western progression of the tropical plume of moisture that has been our main weather feature today. However, until that occurs, southerly winds with high clouds will persist through the evening and overnight. As daytime heating is lost, instability will be lost which should limit shower chances, but due to the plume aloft and plentiful moisture available, any weak disturbances within the plume could result in a brief passing shower. HRRR continues to suggest very light precipitation possible under the plume through the overnight. Confidence on specific locations and timing is low, thus a large blanket of low pops will be used across the forecast area. Again, there will be many dry hours and any precipitation amounts will be light. Given the warm and humid air mass in place along with the expected cloud cover, lows in the lower to middle 70s will be expected. Wednesday... The upper pattern will become more dominated by the large upper high pressure system on Wednesday. The high will retrograde westward, steering any upper forcing dynamics well north of Indiana, to Ontario. This should also effectively begin to block the tropical plume, leading to increased sunshine as these mid and high clouds are lost. Forecast soundings start the day with some high cloud present, but these are lost as the day progresses. Furthermore, forecast soundings show attainable convective temperatures in the upper 80s with CAPE near 1000 J/KG. Thus as high clouds exit and stronger heating is achieved in the afternoon, CU development is expected and brief diurnal showers and storms will be possible. Once again will include chc pops across most of the forecast area, mainly for the afternoon for these light, isolated and brief diurnal showers and storms. Highs should be able to reach the lower to middle 90s. && .LONG TERM (Wednesday night through Tuesday)... Issued at 227 PM EDT Tue Jun 18 2024 Wednesday Night through the Weekend... An extended period of high heat will continue through the weekend, and likely will redevelop again next week. Although the magnitude may not reach extreme heat indices of greater than 105, the extended duration and presence of very warm overnight lows will provide hazardous heat conditions across central Indiana during the long term. This stretch of above normal temperatures will be initiated by the eastward progression of anomalously high heights aloft over the Ohio Valley. This will allow for greater atmospheric expansion and therefore higher temperature values throughout the entire lower 5km of the troposphere. Greater lower troposphere temperatures will be accentuated early this weekend as the ridge axis positions directly overhead, with highest temperatures expected to occur on Saturday afternoon (93-97F). In conjunction with this deep ridging aloft, there will be gradual south/southwest flow due to surface high pressure to the east and north. This will allow for elevated dew point temperatures to remain over the Ohio Valley, generally in the mid to upper 60s. The combination of highs in the 90s and dew points in the low 70s will push heat index values into the upper 90s through Thursday and possibly low 100s Friday and Saturday. As mentioned, this within itself is not overly hazardous, but the fact this is expected over a succession of 4 to 5 days with over night lows in the low 70s puts an even greater risk to vulnerable populations. There are a few potential mitigating factors for high heat and are mainly related to the potential for increased cloud cover and isolated rain chances over the middle of the week. If cloud cover becomes greater than 70% over the afternoon hours, highs may be suppressed lowering the heat risk. Still, overnight lows should not be greatly impacted with dew points remaining in the mid to upper 60s. By Friday, the greatest moisture and lift axis should shift eastward, lowering the threat of afternoon clouds and rain chances for Friday through Sunday. Forecast confidence decreases late this weekend through early next week as a shortwave approaches from the north. High pressure over the Carolinas should impede shortwave progression some, but there is still high uncertainty in how far east a weak pressure trough and associated lift/precipitation will reach. Even so, ridging will remain aloft and any weak wave passage that does occur should only briefly impact surface conditions before upper 80s to low 90s surface temperatures return for the middle of next week. Even looking at the extended range (>10days), the pattern continues to favor general temperatures at or above normal for the next few weeks. With this in mind, expect more 90+ degree days heading into early July. One note about the HeatRisk graphics by WPC. This is an experimental product and values in the current pattern are higher than traditional criteria, and may not be perfectly calibrated to best represent the risk at this time. Thus, we advise users to take this into consideration when viewing the HeatRisk product. && .AVIATION (00Z TAF Issuance)... Issued at 652 PM EDT Tue Jun 18 2024 Impacts: - Low potential for afternoon showers/storms tomorrow Discussion: VFR conditions expected through the TAF period outside of a low chance for afternoon thunderstorms tomorrow which could bring brief MVFR to IFR vsbys. Best chances to see convection will be at LAF with even lower chances at HUF and IND. Otherwise the BKN to OVC ceiling at 200 will gradually begin to clear after daybreak tomorrow with light southerly winds of 5-10kts through the TAF period. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...White SHORT TERM...Puma LONG TERM...Updike AVIATION...White
Area Forecast Discussion
National Weather Service North Platte NE
646 PM CDT Tue Jun 18 2024 .KEY MESSAGES... - Cool conditions on Wednesday with high temperatures 10 to 20 degrees below seasonal values. However, temperatures quickly rebound back into the 80s for the remainder of the week into the weekend. - Near daily shower and thunderstorm chances continue across the area each day through the rest of the week into the weekend. The severe threat remains uncertain at this time. && .SYNOPSIS... Issued at 206 PM CDT Tue Jun 18 2024 Recent GOES-16 WV and RAP 500-mb analysis showed a dome of high pressure centered over the east coast with a ridge extending north- northeastward into northern Quebec. Southwest flow aloft continues across the region as an upper-level trough swings across the northern Plains. At the surface, low pressure was moving northeastward out of eastern South Dakota into Minnesota. An attendant cold front extended southwest into eastern Nebraska and central Kansas to another area of low pressure centered over southwestern Kansas. This front advanced through western and north central Nebraska this morning allowing the strong overnight winds to subside some and shift towards the northwest. At 2 PM CT, temperatures ranged from 61 degrees at O`Neill to 76 degrees at Imperial. The aforementioned cold front has sagged a bit further to the southeast than previously thought with convection initiating along the boundary in our eastern neighbor`s CWA. This ongoing development is occurring south and east of the local area and should continue to move north and east as the afternoon and evening progresses. The potential for a brief shower or thunderstorm exists across far north central Nebraska, generally areas east of Highway 183. Do believe the bulk of the severe threat will reside outside of these areas, though cannot rule out some hail or gusty winds should a stronger storm develop and maintain itself. Anything that does develop should exit the previously mentioned areas by 00Z this evening. && .SHORT TERM /THROUGH WEDNESDAY NIGHT/... Issued at 206 PM CDT Tue Jun 18 2024 Tonight... Thanks to the cold frontal passage, overnight lows will cool back into the 40s and 50s across western and north central Nebraska. Clouds will continue to back build over the region late tonight with relatively light winds out of the north and east as surface high pressure nudges south out of Montana. A shortwave embedded in the flow aloft combined with outflow from the storms to the south should be enough to trigger scattered showers and non-severe thunderstorms to develop after 06Z across southwest into portions of central Nebraska. Wednesday and Wednesday Night... The activity from overnight is expected to wane across the area through Wednesday morning with a cloudy and cool day is in store for the area. High temperatures will be in the mid 60s which is 10 to 20 degrees below normal for mid-June. An upper-level shortwave ejecting out of the central Rockies Wednesday evening will provide another focus for showers and thunderstorms to develop, continuing overnight. Given the cloud cover and cool temperatures, instability will be meager (MLCAPE 300 to 500 J/Kg) with weak deep-layer shear (20 to 30kt), thus anticipate non-severe thunderstorms with this activity. These showers and thunderstorms should bring some moisture to portions of southwest and north central Nebraska, though generally 0.25 to 0.75" appears most likely. Locally higher amounts up to 1"+ may be observed for areas generally east of Highway 83. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Issued at 206 PM CDT Tue Jun 18 2024 Thursday... Showers and thunderstorms are expected to linger into Thursday morning, waning through the afternoon hours. Another upper- level shortwave ejecting eastward out of Wyoming and Colorado will provide a focus for isolated to scattered thunderstorms across the Nebraska Panhandle Thursday afternoon and evening. Mid-level warm air advection (WAA) will result in a capping inversion and when combined with persistent cloud cover, convection may be limited Thursday. With the position of a lee trough near the Colorado/Wyoming border, southeasterly surface flow will increase, helping amplify southeasterly low-level flow and moisture advection across the area. In fact, both the NAEFS and ENS guidance highlighting precipitable water (PWAT) values approaching the 99th climatological percentile, especially north of a warm front expected to lift northward across the Panhandle into the Sandhills. Despite this, details remain rather murky resulting in uncertainty on the degree of the severe risk Thursday given large spread amongst model guidance. Will continue to monitor the severe potential during this period as CAMs get into this time range. Friday and beyond...The cool conditions felt on Wednesday will be short-lived as temperatures warm back into the 80s as the upper- level ridge retrogrades westward into the weekend. Continued southwesterly flow aloft with additional northern stream disturbances tracking across the region will keep the extended forecast in a relatively active pattern. While recurring afternoon and evening thunderstorm chances exists in the extended, the degree of severe potential and coverage remains in question. A return to above normal temperatures and drier conditions will be felt heading into early next week as the upper-level ridge re-amplifies across the Desert Southwest, extending north into the northern Plains. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 641 PM CDT Tue Jun 18 2024 VFR conditions are expected over the next 24 hours. Winds will diminish this evening out of the north to northeast around 10 to 15 kts. There is a chance for rain to move in during the afternoon hours, but at this time coverage remains uncertain, thus have left the mention out of the tafs at this time. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Viken SHORT TERM...Viken LONG TERM...Viken AVIATION...Gomez
Area Forecast Discussion
National Weather Service Melbourne FL
837 PM EDT Tue Jun 18 2024 .UPDATE... Issued at 840 PM EDT Tue Jun 18 2024 The East winds will decrease some over the interior this evening and overnight but remain breezy/gusty along the coast with isolated to scattered showers pushing onshore and well inland. No lightning has occurred over land or the adjacent coastal waters but a couple strikes have been noted well offshore (beyond 60nm) so will keep the slight chance for thunder over the marine zones as well as coastal counties overnight. && .AVIATION... (00Z TAFs) Issued at 840 PM EDT Tue Jun 18 2024 The gusty east winds will subside over the interior terminals tonight but remain 10-15 knots while coastal terminals remain at 15-25 knots. Fast moving SHRA will push onshore and well inland so will carry VCSH. On Wed, similar conds as today are forecast with East winds 15-25 knots, gusting near 30 knots all terminals with SCT SHRA pushing onshore. Will keep CIGs VFR but ocnl MVFR CIGs are likely mainly assocd with passing SHRA. && .PREVIOUS DISCUSSION... Issued at 400 PM EDT Tue Jun 18 2024 Tonight...Breezy to gusty conditions are present across much of the area this afternoon, especially around the Orlando metro and along the immediate coast. RAP analysis shows a tightening pressure gradient over the FL Peninsula, reflected in some of the higher wind gusts in the last couple of hours. Observing sites around Cape Canaveral to Cocoa Beach are reaching gusts of 35 mph and briefly higher at times. A weak disturbance is moving onshore just south of Melbourne and providing the focus for some heavier shower activity. So far, no lightning has been detected in or around these showers, but it cannot be entirely ruled out along the coast or just offshore through the evening. Locally higher gusts to 40 mph at the coast may also accompany this feature as it moves ashore. Wind gusts will persist tonight along the coast, reaching 25 to 30 mph at times, but decreasing to 15-20 mph inland. Isolated to scattered showers are expected to continue with a very low chance for lightning at the coast and over the Atlantic waters. Temperatures will gradually fall into the 70s, staying slightly warmer east of I-95. Wednesday-Thursday...Mid level ridging remains in place through tomorrow but begins to flatten as a weak trough of low pressure approaches the southeast U.S. This is the same feature highlighted by NHC for a low chance of developing tropical characteristics in the next few days. At this point, model guidance does very little with it, other than to provide another wave of moisture and associated shower activity somewhere along the FL/GA or Carolina coastline Thursday afternoon into early Friday. Models remain in some disagreement with regard to the placement and timing of this feature, but an increasing trend to high chance/likely PoPs is forecast Wednesday into Thursday. Brief, localized heavy rainfall is possible as a result, though the QPF remains near 1.20" or less for most locations through Friday morning. Temperatures each day will remain near to slightly below normal with overnight lows ranging through the 70s. A couple of warm low records may occur at coastal sites due to the persistent onshore flow. Gusty winds are forecast to continue, reaching 25-30+ mph at times, especially along the immediate coast. Saturday-Monday (modified previous)...Upper level high pressure centered across the Deep South on Saturday will slowly shift westward through the time, with the axis remaining over the Florida peninsula. Surface high pressure in the western Atlantic will build southwestward over the Florida peninsula through the period. Locally, winds will generally be around 10 mph, with E/SE winds forecast on Saturday before becoming S/SE on Sunday and Monday. The east coast sea breeze is expected to form each afternoon and push inland. Rain chances will remain elevated through early week, with rain chances persisting into early next week. For now, kept likely PoPs out of the forecast due to variability in model solutions. Afternoon highs will be in the upper 80s to low 90s across the immediate coast, and low to mid 90s across the interior each day. Overnight lows will generally be in the low to mid 70s. && .MARINE... Issued at 400 PM EDT Tue Jun 18 2024 Tonight...Hazardous boating conditions will continue as easterly winds 20-25 kt and occasional gusts of 30-35 kt. A Small Craft Advisory remains in effect for all of the adjacent waters through at least Thursday evening. Seas will continue to build, reaching 7-8 ft offshore north of Sebastian Inlet tonight and 6-7 ft nearshore. A stream of isolated to scattered showers is also forecast, with a very low probability of lightning strikes. Some of these showers could mix down locally higher wind gusts at times. Wednesday-Saturday (modified previous)...Poor to hazardous boating conditions will continue through late week as a weak trough approaches the Florida peninsula and southeast U.S. coast. Onshore flow will persist with winds generally 15-20 KT in the nearshore waters and 20-25 KT in the offshore waters through Thursday. Winds will decrease to around 10-15 KT by late week and into the weekend. Seas 6-8ft on Wednesday will increase to 7-9 ft on Thursday, before beginning to subside on Friday with seas decreasing to 4-6ft. A Small Craft Advisory remains in effect for all the Atlantic waters on Wednesday, and has been extended in time through at least Thursday evening. Scattered to numerous showers and isolated lightning storms will be possible each day. && .PRELIMINARY POINT TEMPS/POPS... DAB 76 87 76 87 / 30 60 50 60 MCO 76 88 76 88 / 30 50 30 50 MLB 77 87 77 87 / 50 50 50 60 VRB 76 88 76 87 / 50 50 50 60 LEE 77 90 76 91 / 30 40 20 40 SFB 75 89 75 89 / 30 50 40 50 ORL 76 89 76 89 / 30 50 30 50 FPR 76 87 76 87 / 40 50 50 60 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...Small Craft Advisory until 8 PM EDT Thursday for AMZ550-552-555- 570-572-575. && $$ UPDATE...Kelly
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
704 PM CDT Tue Jun 18 2024 .KEY MESSAGES... - Strong to severe thunderstorms are likely to develop this afternoon and evening. Primary hazards are damaging winds and a chance for a few tornadoes. Locally heavy rainfall is also possible this afternoon into tonight. - Additional rainfall of 0.50" to 1.00" through Wednesday morning. - Pleasant stretch with temperatures in the 70s Wednesday and Thursday. - Next chance for widespread rain arrives Friday into the weekend. && .MESOSCALE... Issued at 406 PM CDT Tue Jun 18 2024 Update on this evening`s severe threat and tornado watch. So far, the storms over western MN have been mostly struggling to sustain themselves, although there`s been a recent uptick in updraft growth. This is likely attributed to a lack of good upper level jet support, which is better over northern MN where storms are better organized and severe. The storms over our area should continue to get a bit better organized over the next hour or two as upper level support is forecast to improve somewhat, but the big question is how much. It will have to improve quite a bit in order to produce more organized/upscale storm growth, and the associated cold pools that would be needed for a more widespread wind and isolated tornado threat. Otherwise the storms will be more pulse in nature with mostly brief wind/hail threats and not much else. Latest runs of the HRRR prefer the pulse mode with a limited severe threat, however some other models are suggesting upper level support could improve just enough for a more organized storm mode with more widespread severe threats. If this were to occur, it appears most likely to occur in the 5pm to 7pm timeframe as the storms approach the I-35 corridor, and we will continue to monitor closely to see if this indeed looks to happen. && .DISCUSSION... Issued at 232 PM CDT Tue Jun 18 2024 Today and Tonight... A busy stretch of weather is on tap for this afternoon and evening. Current observations highlight the tropical-like airmass in place. Temperatures are in the low to mid 80s with dewpoint temperatures in the low 70s. Southerly winds with gusts up to 40 mph will turn northwesterly and decrease overnight behind the frontal passage. Our attention turns to this afternoon`s severe weather set up. A potent sfc low over the eastern Dakotas will lift northeast into northern Minnesota this afternoon. A trailing cold front moves into western Minnesota by early afternoon and will be the focus point for convective initiation. Strong southerly low-level flow will result in continued moisture advection through the afternoon hours. Ahead of the cold front, we`ve seen moderate instability 2500-3500 J/kg build into central and southern Minnesota. Effective shear remains around 30 knots with nearly unidirectional shear aloft, limited by weak flow aloft. Initial storm mode will be multicell with a supercell or two possible but storms will quickly congeal into a linear storm mode given the unidirectional shear profile aloft. Our primary concern will be the potential of damaging wind gusts convection moves through central and southern Minnesota and western Wisconsin. KMPX VAD profile highlights impressive low level SRH values between 200-300 m2/s2 and along with decent speed shear in the lower levels. Given the enhanced low level wind shear, a few tornadoes will be possible this afternoon. This matches up with the SPC SWO update added a 5% TOR area over our MN counties. Our 18z sounding highlights impressive moisture in the lower levels with PWAT of 1.91". The wind profile has some veering in the mid levels. Low level wind profile is impressive with nice curvature in the hodograph. Most importantly, the capping inversion has effectively eroded in the 18z ob. Initiation should when better upper level support arrives mid-afternoon, roughly 2-4PM, with a mixed convective mode before turning more linear. Storms impact the Twin Cities metro between 5 and 8pm. Heading into the evening hours, the front becomes more progressive and will shift the showers and storms into western Wisconsin with an overall diminishing trend by mid to late evening. Wednesday and Thursday... A brief break in the active weather pattern on tap for Wednesday and Thursday. Both days will be dry & pleasant with highs in the low to mid-70s, partly sunny skies, and light winds. Rain chances return Thursday night into Friday ahead of our next system. Friday through early next week...Southwest flow aloft will return and so will the moisture. This will support additional rain chances Friday and Saturday, with an additional 1-2" of rain likely for most locations, and 3"+ still possible where the strongest storms move through. Guidance hints at a slow moving system as it moves into the Upper Midwest on Friday. Placement of the surface boundaries will be important due to the potential for heavy rain. Any additional rain will contribute to additional rises in area rivers and streams for exacerbate flooding concerns into next weekend and early next week. Temperatures appear to warm back up during this period with highs in the 80s. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 641 PM CDT Tue Jun 18 2024 Main issues for this TAF set are the timing of any TSRA into the terminals and how quickly ceilings drop into MVFR/IFR levels behind the storms. Western MN has already had the drop to IFR as evidenced by AXN. The trend is to have those lower ceilings spread east with the precipitation but confidence not quite high enough to go IFR at all terminals so have held ceilings at other sites in MVFR range, waiting to see how trends evolve. As for precip, have backed off the prevailing mention of TSRA in favor of a shorter-duration TEMPO wording as convection does not have the coverage as anticipated earlier. Still, certainly cannot rule out TSRA at any terminal over the first few hours of the 19/00z TAF. Behind the convection, winds will diminish and shift to W-NW with speeds around 10kts. MVFR ceilings will then hold in place overnight through most of tomorrow. If anything, VFR conditions may develop earlier than currently advertised. KMSP...Best window for having convection across the MSP area still looks to be 00z-03z as there are currently echoes near and around MSP that can easily develop into taller thunderstorms. The duration of any given storm will be relatively short, hence the TEMPO mention instead of prevailing. Once the main line, broken as it may be, moves through, wind speeds will diminish and directions will shift to westerly while ceilings drop into MVFR range. MVFR ceilings will then hold through late tomorrow afternoon if not tomorrow evening before conditions improve to VFR. /OUTLOOK FOR KMSP/ THU...VFR/MVFR, chc -TSRA/-SHRA. Wind E 5-10kts. FRI...VFR/MVFR, chc -TSRA/-SHRA. Wind S 10-15kts. SAT...VFR/MVFR, chc -TSRA/-SHRA. Wind SW 10-15kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ MESOSCALE...DPH DISCUSSION...BPH AVIATION...JPC
Area Forecast Discussion
National Weather Service Pueblo CO
642 PM MDT Tue Jun 18 2024 .KEY MESSAGES... - Non zero threat of thunderstorms and a few landspouts in Baca County this evening. - Widespread rain showers and thick clouds across the eastern plains Wednesday, with some thunder over the mountains. - Another warming trend late week into the weekend. - Uptick in thunderstorms over the mountains late week as southerly flow picks up some subtropical moisture. - A return to around 100 degree readings across the plains early next week. && .UPDATE... Issued at 641 PM MDT Tue Jun 18 2024 Quick update to the forecast database due to the expiration of the Red Flag Warning for today. Incorporated latest HRR and RUC model data as well as observations. && .SHORT TERM /THROUGH WEDNESDAY/... Issued at 242 PM MDT Tue Jun 18 2024 Rest of Today... Relatively quiet weather for the first part of today across the CWA, with the front already moving to our south. High temperatures will be cooler than yesterday, with mid-80s to low-90s over the southeast plains and low-80s across most of the higher terrain. Winds will be occasionally gusty but less than yesterday, and humidity over the plains has increased behind the front enough to abate critical fire weather conditions for now. However, the Red Flag Warning will remain this afternoon over the San Luis Valley, as the humidity values out there are still low and were mostly unaffected from the passing front. Our potentially more active weather will happen this evening, as the front stalls out just south of our forecast area. The positioning of the front will be crucial to how much activity we actually see, as convective models show a line of thunderstorms forming along the boundary and intensifying. The majority of models currently show the convection initiating south of our area and largely staying there, however a shift in position just a few miles north could put some storms in Baca County. For any stronger storms that do manage to form over our far southeast plains, enhanced heavy rain, some hail, and even a few landspouts will be possible. Tonight-Wednesday... With post-frontal moisture and lingering convection, wet and unsettled conditions will persist overnight and into early Wednesday. Scattered showers and heavy rainfall will spread across parts of the eastern plains, becoming more widespread the closer you get to the KS border. A few stronger storms will be possible, mainly over our far southeast counties. Precipitation will continue to build west through the night and into the early morning hours, with rain moving over I-25 around sunrise. Showers will start to decrease in coverage closer to the mountains as we move into Wednesday, but a low, thick cloud layer will last into the day. High temperatures on Wednesday will be around 15 degrees cooler than Tuesday, possibly even cooler in some areas thanks to extensive cloud cover. The mountain valleys will not see the full impact of the front, remaining in the high-70s to low-80s. Meanwhile, the moist post-frontal airmass will remain in place with easterly upslope over the plains. More stratiform-type rain showers will spread over most of the eastern plains throughout the day, and though there could be an embedded rumble of thunder, instability will likely be too low. Southwest flow aloft should assist in some weak thunderstorm formation over the mountains, with some locally heavy rainfall being the main concern. Storms over the mountains should stay sub-severe, though locally heavy rainfall could have some impacts in more vulnerable locations. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... Issued at 242 PM MDT Tue Jun 18 2024 Temperatures gradually warm again through late week as southerly flow ahead of the next Pacific trough brings rising heights aloft over CO. The warm up will be somewhat mitigated by an influx in subtropical moisture as the H7-H5 layer specific humidities increase to 6+ g/kg. This will bring an uptick in thunderstorms to the mountains especially Thursday and Friday. Day time humidity values will increase as well which should put an end to critical fire weather conditions for a while, but raise concerns for heavy rainfall on burn scars. Mean CAPE values off national model blends are highest on Thursday ranging from 500-1000 J/kg in the 50-75th percentiles and ranges. They drop around 250 J/kg for Friday. Storm motions will be to the north due to deep southerly flow aloft. A few strong storms will be possible over the mountains where deep layer shears will be around 30+ kts both days. Hail under 1 inch in diameter and wind gusts up to 50 mph will be possible. Best forcing will be late Friday as the dampening western U.S. upper trough ejects across NW CO. This may keep some showers and isolated thunderstorms going most of the night across the mountains though intensities will be weaker with loss of heating during the overnight hours. Drier and warmer weather returns for the weekend into next week as the upper ridge aloft builds over the southern/central U.S. Rockies. Temperatures will be back up to around 100 across the plains for Monday and Tuesday. Probabilities for afternoon and evening showers and thunderstorms gradually decrease though winds look to stay below critical fire weather thresholds. -KT && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 548 PM MDT Tue Jun 18 2024 KALS: VFR conditions are expected over the next 24 hours. Winds will remain relatively light overnight, and then start to increase during the early afternoon. Mid level clouds will also start to increase some during this TAF period, but dry conditions are anticipated through tomorrow. KCOS and KPUB: VFR conditions are expected through this evening, with MVFR conditions developing overnight and persisting through much of this TAF period, primarily due to low clouds. Speaking of clouds, mid to low level clouds will develop overnight and remain in place through much of this TAF period, with minor lifting/thinning of clouds possible near the end of this TAF period. Along with that, drizzle to light rain is expected as moist east to southeast upslope flow prevails. Otherwise, pockets of light precipitation are expected around both TAF sites through much of tonight and tomorrow. && .PUB WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...MOORE SHORT TERM...GARBEROGLIO LONG TERM...KT AVIATION...SIMCOE