Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/26/18


Area Forecast Discussion
National Weather Service La Crosse WI
1058 PM CDT Wed Jul 25 2018 .SHORT TERM...(This afternoon through Thursday) Issued at 214 PM CDT Wed Jul 25 2018 Main concern remains potential for strong to severe storms across much of the forecast area into this evening. An early afternoon look at satellite/radar/obs showed an area of showers with occasional thunder associated with a weak shortwave moving into southeast Minnesota. A cold front was draped northeast to southwest across central Minnesota and will likely serve as the main focus of convection this afternoon/evening, though still not a lot of confidence on how everything will play out. The general idea is that the front will approach from the northwest, and with increasing moisture transport ahead of the front by late afternoon, storms are expected to develop just northwest of the front. In addition, a stronger shortwave will move across central Minnesota into northern Wisconsin this evening, providing a little bit better forcing in these areas. Despite a fair amount of instability, the showers moving into southeast Minnesota were quickly dissipating due to very little forcing. With this lack of showers to use up the instability, combined with a little less cloud cover than expected, could see a bit more instability than first thought (SBCAPE approaching 2000 J/kg). However, the strongest deep layer shear looks to remain mainly behind the front/storms, though could see a very narrow corridor right along the front where the best shear overlaps the instability. This would be the most favorable area for any organized storms and severe weather. Looking at severe weather types, thinking wind and maybe hail will be the greatest threats. Despite the strongest deep shear being behind the storms, 0-3 km shear looks decent, with around 25 kts or so ahead of the front, with much of it being line-perpendicular. In addition, forecast soundings show deep mixing in the lower levels, though the RAP does seem a bit overdone with this, as we are not seeing any wind gusts over 25 kts like it suggests with its winds at the top of the mixed layer. Mid-level lapse rates near 6.5 C/km and the aforementioned instability also suggest a hail threat, but thinking the signals for wind are a little stronger. Unlike previous severe weather events, heavy rain does not appear to be a major threat, with precipitable water values in the 1.3-1.5 inch range and shallower warm cloud depths (which are also more favorable for hail) in the 3-3.5 km range. Bottom line, thinking the convection will be in a somewhat unorganized, broken line along the front with a few cells/bowing segments producing strong to damaging winds and hail. The front and storms should be out of the area by midnight, with a breezy, cool day on tap for Thursday with 20+ mph wind gusts out of the northwest. High temperatures look to be in the mid 60s to mid 70s. In addition, with cyclonic flow remaining in the area, could see a few "popcorn" light showers, especially if we manage to get a bit of sunshine to peek through the clouds. .LONG TERM...(Thursday night through Wednesday) Issued at 214 PM CDT Wed Jul 25 2018 For Thursday night thru Saturday night: main fcst concerns are the cooler, below normal temperatures thru the period. 25.12z model runs in good agreement for NW flow aloft to continue developing over the Upper Midwest Thu night/Fri, with second shortwave trough/energy to dig in and help carve out even deeper troughing aloft over the region by Sat/Sat night. Confidence is good for Thu night thru Sat night to be a seasonably cool period across the area. A cool low level airmass settles over the area Thu night but NW gradient winds looking to remain in the 5-10mph range to keep BL stirred and lows from dropping too far, even after the seasonably chilly temps on Thu. Even so, consensus lows in the low-mid 50s are going to feel cool. Weak sfc high pressure to slide over the area Fri, for much lighter winds than Thu. Highs to recover a bit Fri without the brisk NW winds and cold advection, with mixed 925mb temps supporting highs in the 70s. With lighter winds Fri night will have to watch for the potential of late night valley fog along with lows in the normally colder low laying areas dipping into the 40s. Lower level trough and some thermo-dynamic forcing to accompany the round of shortwave energy to move into/ across the region later Sat/Sat night. Some small, mainly SHRA chances and mainly west of the MS river later Sat/Sat night, along with highs/lows a category or 2 below normal, OK for now. For Sunday thru Wednesday (days 4 to 7): main fcst concerns this period are some SHRA/TSRA chances Sun/Mon and continued below normal temps thru Tue. Medium range model runs of 25.00z/25.12z in rather good agreement for an anomalous cold mid level troughing to settle over the central/ eastern CONUS Sun/Mon then persist into the middle of next week. NAEFS std deviations of -2 to -3 on 500mb hgts/temps Sun-Tue with some slow modification/warming by Wed. Fcst confidences is average for precip chances this period but good for temps to remain below normal, at least thru Tue. Some signal for a lower level low/trough to swing thru the region under the deep, cold cyclonic flow of the mid level troughing Sun/Mon. This along with potential for plentiful lower level moisture in the circulation. Consensus 20-40% SHRA/TSRA chances mainly Sun/Mon afternoons reasonable at this point. More of a signal for lower level high pressure, and drying to build in for Tue/Wed. Some more southerly lower level flow and warm advection even progged to return on Wed. Until then, general northerly flow and below normal 925-500mb temps to keep highs/lows for Sun thru at least Tue night in the below normal range as July comes to an end and the calendar turns to Aug. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1058 PM CDT Wed Jul 25 2018 Showers and storms have exited the area as a cold front has pushed east of LSE and RST, with clearing skies noted. Much cooler air filtering into the region behind that front will allow for a rather rapid expansion of stratocumulus clouds Thursday morning and afternoon, with primarily VFR ceilings expected but some low end chance RST could see brief intervals of MVFR conditions. Winds will become a bit gusty from the northwest during the day Thursday, with gusts either side of 20 knots expected for all areas. In addition, there is a risk for isolated showers to develop during the afternoon hours, though will refrain from any mention at this point for the TAF sites given uncertainty. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...CA LONG TERM...RRS AVIATION...Lawrence
Area Forecast Discussion
National Weather Service Burlington VT
1055 PM EDT Wed Jul 25 2018 .SYNOPSIS... Welcomed rainfall will continue tonight as deep moisture shifts east across the area. Dry weather returns by tomorrow before additional showers and a few thunderstorms return for Friday into Saturday. Temperatures will remain seasonably mild to warm through the next week with no excessive heat expected. && .NEAR TERM /THROUGH THURSDAY NIGHT/... As of 1054 PM EDT Wednesday... Moderate to heavy showers are over the Champlain Valley at the moment with the trough positioned just to the west. Most lightning has ceased with this line of showers and it has begun to slowly weaken. This has been depicted well in hi-res guidance and this activity will continue to gradually weaken as the front pushes east and interacts with an advancing shortwave moving northward along the southern New England Coast. Latest guidance suggests this will move through a little faster and be positioned a little further east. Have adjusted temperatures and PoPs for the latest trends, mainly to clear out New York a little faster and then to allow rain to move out a little faster Thursday morning. All else remains in excellent shape. Have a great night. .PREVIOUS DISCUSSION... The forecast remains largely on track for this evening into tonight. We continue to watch a deep subtropical moisture plume oriented from southern Quebec southward into the coastal Mid- Atlantic and southeastern seaboard this afternoon. This axis lies on the western periphery of pronounced western Atlantic ridging centered near 40N/- 60W which has been semi-stationary over the past 48 hours. Within this band scattered to numerous showers continue, though in the immediate Champlain Valley we`ve largely missed the activity so far. This is illustrated quite well in some of the higher-res model output, most notably in the NAM 3km and HRRR and as such have leaned heavily toward their solutions over the next 12 hours accordingly. This will keep steadiest/heaviest showers mainly across northern NY through early evening before a gradual shift east into VT is expected later this evening into the overnight hours as a weak shortwave feature tracks north- northeast through southeastern New England. Instability is rather meager and with near moist- adiabatic lapse rates only an outside shot of thunder is expected and mainly through midnight or so. I`ll also maintain locally heavy rainfall wording given the aforementioned moist airmass, though to be honest, outside a few stripes of heavier rainfall model-blended QPF has been grossly overdone in most spots for this event so far. To maintain temporal and spatial continuity with our prior forecast I leaned toward a blended solution of our official forecast and most recent WPC guidance for QPF though with a 50% reduction factor given this bias. This will support additional basin- averaged rainfall of a quarter to half inch from the eastern slopes of the Adirondacks eastward overnight, though with full realization that there will be a few stripes of heavier totals from 0.75 to 1.5 inches in more persistent shower bands. Lows tonight to remain quite mild under continued light southerly flow - mainly in the 60s to locally near 70 in mildest valley locales. Any morning rainfall across eastern counties then edges eastward over time on Thursday leaving a largely dry afternoon under increasing partial sunshine from the Champlain Valley westbound. Model-averaged 925 mb temperatures rebound into the 20-24C range in these areas by late afternoon and with decent boundary layer mixing to near 850 mb high temperatures were raised several degrees (i.e. a spot high of 88F at KBTV and 85F at KMSS). Further east, clouds will likely hang on through at least mid-morning to early afternoon, tempering readings slightly (upper 70s to lower 80s). Then mainly quiet by Thursday night as we remain under broad southwesterly flow ahead of an approaching surface trough to our west. Generally advertised a broad increase in clouds by later at night with chances of a few showers across western counties toward sunrise as this feature approaches. Lows remain mild in the 60s. && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... As of 324 AM EDT Wednesday...Highlight for the period continues to point towards the convective potential on Friday as a secondary cold front swings through the region. Should be a fairly mild and muggy night ahead of the boundary Thursday night with lows widespread in the 60s and little dewpoint spread. Come 12Z Friday morning the front looks to be on the BTV CWA doorstep with showers developing across northern New York during the mid-morning hours. Increasing clouds and precipitation should keep instability at a minimum here, but eastward the potential for some stronger storms to develop still looks plausible with daytime surface heating aiding in SBCAPE`s pushing over 1000 J/kg. This, combined with PWAT`s surging back up over 1.5", decent upper jet dynamics and modest low level shear certainly supports the idea of scattered to numerous showers and thunderstorms developing through the afternoon from the Adirondacks eastward with the potential for a few strong to locally severe storms. Any convective activity wanes Friday night as the front shifts east of the forecast area and surface instability weakens with the loss of insolational heating. A few lingering showers are possible across eastern Vermont through midnight, but thereafter drier conditions are expected for the remainder of the night. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 324 AM EDT Wednesday...Drier and more comfortable conditions are still expected for the upcoming weekend as surface high pressure builds into the region. An upper level trough lifting northeast through southern Canada could provide enough energy to spark a few isolated showers Saturday, but for most areas dry conditions are expected through the weekend under partly cloudy skies. Temperatures will be right around seasonal normals - highs in the mid 70s to low 80s, and lows in the mid 50s to low 60s with comfortable humidity expected as well. Unfortunately this pattern change will be only brief as the upper trough to our west and Bermuda high to our southeast both look to become reestablished, with the return of a deep tropical southwest flow across the majority of the East Coast. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... Through 00Z Friday...band of moderate to heavy showers along with isolated tsra is slowly pushing across northern NY and reaching the Champlain Valley at this time. Primarily VFR across VT right now, but as the precipitation overspreads the area, expecting MVFR conditions (both ceiling and visibility) to develop. Could be brief IFR visibilities, and in fact SLK briefly dropped to 1/4sm when the heavy rain moved over. In general looking at the heaviest of the rains to effect PBG/BTV through 04z, RUT 02-06z, MPV 03-07z. Indications are that light showers will continue for much of the night with even the threat beyond 13z for many of the VT terminals. Want to note that some guidance is indicating fog to form after 05z across parts of the St Lawrence Valley and into the `Dacks, with LIFR for MSS and SLK. If the clouds do clear out, that is quite possible, but at this point think enough clouds and a few showers around will keep the potential for such fog to develop at a minimum. VFR conditions will develop between 13-18z from west to east on Thursday. Outlook... Thursday Night: VFR. Slight chance SHRA, Slight chance TSRA. Friday: VFR. Chance SHRA, Chance TSRA. Friday Night: VFR. Chance SHRA, Slight chance TSRA. Saturday: Mainly VFR, with local MVFR possible. Chance SHRA. Saturday Night: VFR. Slight chance SHRA. Sunday: VFR. Slight chance SHRA. Sunday Night: VFR. Slight chance SHRA. Monday: VFR. Chance SHRA. && .EQUIPMENT... As of 345 PM EDT Wednesday...The KCXX radar continues to have calibration issues and this is causing problems with dual-pol derived precipitation. The dual- pol derived rainfall amounts appear to be much greater than what is actually being observed. The legacy rainfall products appear to be more reliable based on observations. A technician visited the site yesterday and has ordered replacement parts with the expectation that a more thorough diagnosis will be performed later this week, weather permitting. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...JMG NEAR TERM...Haynes/JMG SHORT TERM...Lahiff LONG TERM...Lahiff AVIATION...Nash MARINE...JMG EQUIPMENT...Team BTV
Area Forecast Discussion
National Weather Service Cheyenne WY
936 PM MDT Wed Jul 25 2018 .UPDATE... Issued at 933 PM MDT Wed Jul 25 2018 Although several lines of thunderstorms are moving east southeast across southeast wyoming and the southern NE panhandle late this evening, the heavy rain threat is over for tonight with only brief heavy rain possible. Cancelled the Flash Flood Watch near the Colorado border. Will have to monitor Thursday and Friday for another slight risk of flash flooding and the potential for more strong to severe thunderstorms. Kept POP between 50 to 80 percent through midnight, with the exception of the northern Nebraska panhnadle. && .SHORT TERM...(This evening through Thursday) Issued at 300 PM MDT Wed Jul 25 2018 Conditions are coming together for a possible heavy rain/severe thunderstorm event this afternoon and evening. Forecast challenges deal with severe thunderstorm and heavy rain potential this afternoon and tonight. Currently...Water vapor imagery showing an upper level shortwave located across central Wyoming this afternoon with a surface boundary located from Alliance to Casper. Earlier boundary located across southeast Colorado up to near Saratoga. Afternoon dewpoints quite high with Cheyenne at 57F with low to mid 60s in the Panhandle. Radar showing convection blossoming across Carbon and Albany Counties this afternoon, being the closest to the upper level shortwave. SPC Mesoanalysis page showing surface based CAPE of 1500 to 1600 J/KG with bulk shear on the order of 45-50kts across the Laramie Range and points east. CAPE forecasts continue to rise to near 2500-3000 J/KG by 00Z. Will continue with threat of severe convection this afternoon. Got a report from the Summit just a few minutes ago that ponds are full up there from thunderstorms yesterday, so decided to add the Summit into the Flash Flood Watch this evening. Forecast soundings after 00Z showing long/skinny CAPE profiles indicative of heavy rain with PWATS close to 1.25 inches. Heaviest rainfall forecast between 00Z and 06Z this evening. Another round of heavy rain possible Thursday afternoon. SPC has another Marginal Risk area identified, so conditions similar Thursday afternoon to today. Later shifts will likely need to issue another Flash Flood Watch for Thursday. .LONG TERM...(Thursday night through Wednesday) Issued at 300 PM MDT Wed Jul 25 2018 Perhaps our biggest day severe/heavy rain wise will be Friday as models show surface boundary shifting east into Nebraska. Some differences in forecast solutions seen as GFS thrusts the font into North Plattes area. ECMWF much further west in the Panhandle with heavy rainfall covering much of the Panhandle. Should the ECMWF solution come true, we could be looking at widespread severe weather in the Panhandle and parts of extreme southeast Wyoming. Would think the ECMWF has a better handle on the placement of the surface boundary and have kept PoPs pretty high based on this model output. Front backs to the west on the ECMWF Friday night into Saturday as an upper shortwave tracks across western Nebraska Friday evening. SPC has already identified a Slight Risk area for the Panhandle in their Day 3 outlook, so confidence fairly high on the ECMWF solution. Widespread afternoon/evening showers and thunderstorms expected again Saturday and Sunday as the surface boundary stalls along the Laramie Range. Both days could see severe thunderstorms as upper level disturbances ride over the front both days. Drier weather still expected from Monday on into the rest of next week. Four corners high still forecast to shift west into the southern Nevada area, cutting off monsoonal moisture flow into Wyoming. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 527 PM MDT Wed Jul 25 2018 Possibly another round of storms near KCYS over the next couple hours. Thinking mostly showers though as latest HRRR does show another area developing this evening and becoming fairly widespread. Next chance for thunderstorms will occur Thursday afternoon as daytime heating produces instability. && .FIRE WEATHER... Issued at 300 PM MDT Wed Jul 25 2018 Minimal fire weather concerns over the next 3-4 days as monsoonal moisture remains in place and widespread wetting rains are expected. Afternoon humidity expected well above critical levels with good to excellent overnight recoveries. Heavy rainfall expected along the Interstate 80 corridor from Sidney to Laramie could lead to possibility of flash flooding this afternoon and again Thursday. Drier weather expected to return Monday and continue into most of next week. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ UPDATE...TJT SHORT TERM...GCC LONG TERM...GCC AVIATION...GCC FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
252 PM PDT Wed Jul 25 2018 .SYNOPSIS...Hot and dry conditions will continue across inland areas for the foreseeable future, with typical cool and periodically cloudy conditions near the coast. && .DISCUSSION...Given the complete lack of cumulus development across our interior mountains, suspect we will not see any shower or thunderstorm development this afternoon or this evening. Weak cu field and hi-res model guidance continue to point toward isolated storms in eastern Siskiyou county, to the northeast of our forecast area. Meanwhile, the low-level wind flow continues to carry most of the smoke from the Carr and Natchez fires off to the northeast of Trinity and Del Norte county as well. HRRR smoke model does indicate some smoke aloft trying to push southward across Del Norte and western Humboldt county on Friday, which could happen with the increasing northerly flow. Did not reflect this in the forecast yet, but this may be something we add if we begin to see the smoke begin drifting south/southwestward. Otherwise, the forecast message remains largely unchanged, with very seasonable conditions albeit with above average temperatures inland. Heat advisories will continue for interior areas with elevated risk of heat-related illnesses continuing, especially for those groups sensitive to hot temperatures. Considered extending the heat advisory into Friday, but there will be some slightly lower high temperatures that day as an upper-level trough drops across the Pacific Northwest, putting a slight dent in the dominant upper-level high pressure system across the southwestern United States. More noticeable lowering of high temperatures will occur this weekend, but interior valleys will still reach into the upper 90s in many locales. At the coast, the waxing and waning of coastal stratus will largely continue, with much cooler conditions compared to inland areas. Expect sunshine away from the beaches still during the afternoon hours. Some increasing in northerly winds over the coastal waters may help to increase the duration of clearer skies around Shelter Cover, Crescent City, and much of the Mendocino coast by Friday and heading into the weekend. && .AVIATION...Coastal conditions have been quite consistent over the last few days. Marine stratus continued to blanket the coastal waters and near shore airports...including ACV and CEC. These air terminals were frequently at or below the airfield minimums as CIG/VIS dropped into LIFR/IFR today. A coastal shear zone produced BINOVC just offshore, although onshore flow kept low CIGS mostly piled up over the main air terminals. Expect to see deteriorating of CIG/VIS by early evening once again as the cool moist air rolls back over the coastal shores. Profiler continued to show a fairly shallow but persistent marine layer as the inversion appears strong and nearly static. Flying conditions over inland mountain and valley areas will continue with VFR. /TA && .MARINE...Light to moderate northerly breezes will continue tonight. Northerly winds will begin to ramp up tomorrow and especially for Friday and the weekend near and south of Cape Mendocino. Seas will remain fairly low until the winds begin picking up, still dominated by short period northerly wind waves. Mixed longer period southerly swell will start lowering tonight. The combination of short period northerly wind waves and long period southerly swell will create uncomfortable boating conditions in some shoaling areas. Patches of fog may also reduce vsbys to 1/4SM or less, especially nearshore and through harbor entrances. && .BEACHES HAZARDS...A longer-period southerly swell will continue to impact northwest California beaches through the late afternoon hours, in particular the south facing beaches like South Beach, Shelter Cove, and Point Arena. This south swell will generate longer lulls between sets of larger waves. These larger sets of waves can catch beach goers off guard. Beach goers should stay off rocks and jetties and stay farther back from the ocean. All indications are that the swell is lowering in period and in amplitude, probably closer to 3 to 4 feet at 16 seconds, which should reduce the threat of larger breaking waves. Will continue the statements for the beaches and the coastal waters through 5 pm this afternoon. && .FIRE WEATHER...Little change to the forecast package this afternoon as hot and dry conditions will persist through the rest for the week, only easing slightly this weekend. Interior temperatures will soar into the upper 90s to mid 100s during the afternoon with some areas around Ukiah and along the Trinity River peaking between 105 and 110. Overnight recoveries will remain good in the valleys, but only moderate in upper elevations within the thermal belt. Winds will remain mostly light and heavily influenced by terrain, with perhaps slightly breezier northerly winds in exposed areas during the afternoon hours. && .EKA WATCHES/WARNINGS/ADVISORIES... CA...Beach Hazards Statement until 5 PM PDT this afternoon for CAZ101- 103-104-109. Heat Advisory until 11 PM PDT Thursday for CAZ107-108-110-111- 113. NORTHWEST CALIFORNIA COASTAL WATERS...None. && $$ Visit us at http://www.weather.gov/eureka Follow us on Facebook and Twitter at: http://www.facebook.com/NWSEureka http://www.twitter.com/nwseureka For forecast zone information see the forecast zone map online: http://www.weather.gov/eureka/zonemap.png
Area Forecast Discussion
National Weather Service Fort Worth TX
950 PM CDT Wed Jul 25 2018 .UPDATE... The inherited forecast is in pretty good shape. Made some minor tweaks to re-trend the near term hourly elements based on recent observations, and to nudge sky cover upwards for the overnight hours and into Thursday morning. Convection is blossoming ahead of a cold front which bisects Kansas from northeast to southwest at this hour. While additional activity may develop into the Oklahoma/Texas Panhandles overnight, none of this activity is expected to survive the trek across Oklahoma as it encounters an increasingly dry and stable airmass. This convection will, however, throw some additional mid and high cloud cover our way, so nudged sky coverage up late tonight and into Thursday. Several evening CAMs are showing some high-based convection developing across our far western/northwestern counties Thursday afternoon and evening, and recent RAP soundings do show locales west of US-281 becoming uncapped as a modest increase in surface dewpoints results in a few hundred J/kg of MLCAPE. Given the surfeit of dry air present in the sub-cloud layer (under 10 kft), it seems unlikely much in the way of precipitation would reach the ground unless more robust updrafts can be established. For the time being, just added some silent 10% PoPs across this portion of the CWA tomorrow afternoon. If a stray storm were to develop here, an isolated downburst threat would exist with near 40 degree dewpoint depressions during peak heating. Carlaw && .AVIATION... /Issued 657 PM CDT Wed Jul 25 2018/ /00z TAFs/ Surface winds early this evening will generally be out of the east-southeast, but will gradually veer to the south overnight with speeds remaining under 8 kts or so. By Thursday morning, winds may briefly come all the way around to the west-southwest ahead of a weak cold front which will be dropping into Central Oklahoma, but predominantly south winds should return during the afternoon as mixing brings more southerly momentum down to the surface. Cloud cover around FL300 will increase late tonight and into Thursday as anvil debris from upstream convection drifts across North and Central Texas. Diurnal Cu with bases near FL080 will also be a bit more prevalent Thursday afternoon as we mix into moisture around 700 mb. Finally, there may be an outside potential for some high-based convection to develop late Friday afternoon/evening ahead of the aformentioned cold front, but a very dry sub-cloud layer points to impacts mainly from turbulence associated with evaporating precipitation. Carlaw && .SHORT TERM... /Issued 301 PM CDT Wed Jul 25 2018/ /Tonight/ Another shortwave trough will move out of the Central High Plains tonight, bringing showers and thunderstorms to parts of the Panhandle and Eastern New Mexico. Much like Tuesday night, North Texas will only see a slight increase in high clouds overnight. Lows tonight will fall into the 70s with a light south to southeast wind. 79 && .LONG TERM... /Issued 301 PM CDT Wed Jul 25 2018/ /Thursday through Wednesday/ The upper ridge over the Desert Southwest will begin to deamplify Thursday through the weekend while a strong upper trough and associated cold front brings cooler and unsettled weather from the Northern Rockies to the East Coast. It will remain hot across North and Central Texas through the weekend with highs mainly in the upper 90s to near 102 and lows generally in the 70s. One notable change will be a slow but steady increase in humidity as southerly winds return in response to a deepening surface lee trough across the Central High Plains. The increase in humidity and the approach of the cold front from the north will also bring some low shower and thunderstorm chances generally north of I-20 Thursday night through Sunday. We will keep PoPs low since moisture will be shallow. However, any storms that do manage to develop will be capable of gusty downburst winds. Relatively cool and dry air is progged to build southward across the Central Plains Sunday while an upper trough deepens across the Great Lakes and the Midwest. This airmass will move into North Texas Sunday and make it all the way to the Upper Texas Coast by Monday night. Showers and thunderstorms will accompany the cold front with the best rain/storm chances Sunday night and Monday. Precipitation chances will end by Tuesday, but dry and relatively cool air will remain in place through the middle of next week with highs generally in the lower 90s and lows ranging from the upper 60s to the middle 70s. The threat for new fire starts will remain high through the weekend due to hot/dry weather and abundant dry vegetation. Wind speeds should remain generally less than 15 mph through the end of the week, but it will become breezy on Saturday which will elevate the fire threat even more. The fire threat should decrease temporarily early next week due to cooler temperatures and the chance for widespread wetting rainfall. 79 && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 78 102 80 99 79 / 0 0 5 10 20 Waco 75 102 76 102 77 / 0 0 0 0 5 Paris 73 100 75 94 74 / 0 0 10 30 20 Denton 74 102 77 98 77 / 0 0 5 10 20 McKinney 74 101 77 98 76 / 0 0 5 10 20 Dallas 80 102 82 100 80 / 0 0 5 10 20 Terrell 74 102 77 100 77 / 0 0 5 10 20 Corsicana 75 102 76 101 77 / 0 0 0 5 5 Temple 74 102 74 101 75 / 0 0 0 0 0 Mineral Wells 73 102 75 99 75 / 0 0 5 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$ 90/25
Area Forecast Discussion
National Weather Service Goodland KS
544 PM MDT Wed Jul 25 2018 .SHORT TERM...(This evening through Thursday) Issued at 115 PM MDT Wed Jul 25 2018 A fairly high impact severe weather event is expected across much of the area this afternoon and tonight. It will occur in two rounds. The first round will develop along a cold front/outflow boundary apparent on radar, which has stalled out roughly along Interstate 70. Once the cap breaks, the environment will be characterized by strong instability along/north of the front (up to 3500 j/kg) and moderate to strong instability south of the front, with deep layer shear of around 40kts. Upper forcing is rather weak, with only the hint of shortwave trough coming over the western ridge. Nonetheless, the frontal boundary should be sufficient for convective initiation. Initial storms will be capable of producing very large hail, damaging winds and perhaps an isolated tornado near the surface boundary. Storm motions are southeast at around 15kts with right movers more south also at 15kts, suggesting a limited flash flood threat, at least initially. However, a second round of thunderstorms will develop in the post frontal upslope regime in northeast Colorado and move across most of the area this evening. These storms will probably congeal into an MCS capable of producing widespread damaging wind gusts and embedded storms capable of producing large hail. The complex will be moving rather slowly and could continue well into the overnight hours. With heavy rain from the complex occurring over areas that may receive heavy rain from the afternoon storms, issued a Flash Flood Watch, with good support from the ensemble HRRR which shows storm total accumulations of 1-2 inches over much of the Flash Flood Watch area through tonight. After any lingering storms dissipate Thursday morning, expecting a less active day. Surface front will be pushed well to the south by the convection, leaving the local area with a broad, southeasterly surface flow. Without the boundary for initiation, any storms will be tied to development on the higher terrain to the west with elevated heating. Upper forcing, if any, is lacking. Also, clouds will keep temperatures only reaching the upper 70s to lower 80s, limiting instability. So, only carrying some slight to chance pops on western and northern fringes of the forecast area for Thursday afternoon. .LONG TERM...(Thursday night through Tuesday) Issued at 1113 AM MDT Wed Jul 25 2018 As of 00Z Friday, the forecast begins with an actively-shifting pattern due to recent frontal passage. The region is expected to be situated between an upper-level ridge over the SW CONUS and a longwave trough over the Great Lakes. Both the NAM and the GFS are displaying moisture throughout the column from 1000mb - 300mb. The upper-level ridge is expected to break down and give way to a longwave trough and its associated frontal system by Monday at 00Z. 300mb. Friday morning, a warm sector will form between the leeside trough and the lingering stationary boundary over KS/OK. Friday`s PoPs indicate precipitation between 00Z and 06Z and again in the evening and into Saturday morning. Most of Saturday appears to be wet with precip extending into the early evening. SPC is anticipating a slight risk for scattered severe storms to form due to steep mid- level lapse rates, moderately high CAPE values, and a "strong deep layer beneath 30-40kt northwesterly mid-level flow." This trend is expected to continue for the remainder of the weekend. After Sunday, the boundary transitions to a more organized frontal system and it moves out and goes south, causing the area to dry out, and no more precipitation is expected through Wednesday. Higher pressure builds in and conditions become more stable. Cloud cover is expected to clear out, wind speeds should return to 10kt or less, and temps steadily rise into the upper 80s-lower 90s by the end of the period. Friday`s temperatures will be moderated by the recent frontal passage from Wednesday. High temperatures are expected to be in the high 70s - low 80s. Low temperatures are expected to be in the upper 50s- lower 60s. Sunday evening will reach the upper 70s across the entire area. We are not expected to heat up again until Tuesday afternoon/evening with temps topping out in the upper 80s. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 515 PM MDT Wed Jul 25 2018 GLD will start out VFR with scattered thunderstorms between 04Z- 10Z followed by intermittent IFR conditions due to lower ceilings first thing Thursday morning between 10Z-13Z. VFR will prevail after 13Z with light northeast winds turning southeast. MCK will have VFR conditions with scattered thunderstorms between 03Z-09Z. MVFR conditions due to lower ceilings are expected intermittently between 11Z-14Z to be followed by VFR conditions and light northeast winds turning easterly. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...Flash Flood Watch until 3 AM MDT /4 AM CDT/ Thursday for KSZ001>004-013>016-027>029-041-042. CO...Flash Flood Watch until 3 AM MDT Thursday for COZ090>092. NE...NONE. && $$ SHORT TERM...024 LONG TERM...SANDERSON AVIATION...JSL
Area Forecast Discussion
National Weather Service Gray ME
944 PM EDT Wed Jul 25 2018 .SYNOPSIS... A weak cold front will push in from the west tonight and will dissipate over the region on Thursday. A secondary cold front will approach from the west Thursday night and will stall over the region by late in the day Friday. The front will gradually shift offshore on Saturday. High pressure will build in from the west Saturday night and Sunday. High pressure will shift offshore on Monday. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Update... Continue to monitor mesoscale models and latest radar imagery for the potential of locally heavy rainfall tonight. As has been the case for the last few days, most of the showers remain over New Hampshire and along the NH/ME border in Oxford county. Expect that trend to continue for another couple hours Thereafter, a more organized area of showers with embedded thunderstorms will approach from the waters south of Nantucket very late this evening or shortly after midnight. Latest HRRR suggests this heavy precipitation will cross the region mainly between 06Z and 12Z. Prev Disc... Weak cold front will continue to slowly push in from the west this evening and overnight. Showers ahead of this boundary are becoming more widespread across New Hampshire and will be edging into western Maine through early evening along with scattered thunderstorms. Expect rain to be heavy at times overnight with most areas picking up 1 to locally 2 inches. Dense fog lurking along the coast will push inland during the evening hours. Will see a warm and muggy night with lows in the mid 60s to lower 70s. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... Steady rain will give way to partly sunny skies and scattered afternoon showers and thunderstorms as weak frontal boundary generally washes out over the region. Highs will top out in the mid 70s to mid 80s. Showers will die out with loss of heating Thursday evening and expect partial clearing with areas of fog overnight. Lows will range through the 70s. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Friday morning begins with continued southwest flow aloft in place over northern New England. As has been the case as of late, expect scattered showers and isolated thunderstorms to develop as the day progresses. Chances are higher over the mountains where orographic lifting will help with initiation. Not really much in the way of any kind of airmass change, so fairly warm and humid conditions continue. Saturday looks to be something of a repeat of Friday, only with slightly more scattered showers. A weak frontal boundary will finally serve to scour out some of the humidity as drier air moves in Saturday night and into Sunday. Relatively quiet conditions continue on Monday and then Monday night and into Tuesday the trough over the Great Lakes will amplify a bit. This will once again allow warmer and more humid air to stream in from the south with an increased chance of precipitation. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... Short Term...Areas of IFR/LIFR ceilings and vsby overnight...mainly in southern interior and coastal zones. Becoming VFR on Thursday with areas of MVFR/IFR ceilings and vsby in showers and thunderstorms. VFR Thursday night with areas of IFR/LIFR ceilings/vsby valley fog. Long Term...Mainly VFR conditions with IFR/LIFR conditions in showers and fog Friday night and into Saturday. && .MARINE... Short Term... Continuing SCA`s for the overnight through tomorrow morning. Long Term...No flags expected. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until noon EDT Thursday for ANZ150-152- 154. && JC/WW
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
934 PM CDT Wed Jul 25 2018 .UPDATE... Updated for evening discussion. && .DISCUSSION... The overnight forecast was updated to lower min temps. We remain in a light northerly flow pattern, providing seasonably dry and pleasant conditions. Just a few high clouds were sliding across the Mid South, clipping the Golden Triangle, with a mostly clear sky to remain overnight. Given the clear and dry conditions, I see no reason we shouldn`t achieve temps at least as low as this morning, if not a degree or two lower in a few areas. Forecast min temps were adjusted downward to reflect more of a persistence approach. No other notable adjustments were needed. /DL/ Relevant portions of prior discussion below: Through Thursday: No major concerns for the forecast period. Latest RAP and satellite analysis continued to show the ridge trough pattern over the CONUS. This was characterized by anomalous mid to upper ridging centered over the Desert Southwest US and troughing east of the MS Valley. On the surface a weak surface boundary was observed pushing south over southern Mississippi and eastern Louisiana. With surface high pressure in control, mid afternoon readings were in the upper 80s to lower 90s. In the wake of the weak frontal boundary, dewpoints were in the mid to upper 60s, which has brought limited temporary relief to the humid conditions. For the period, dry conditions are expected to continue. On Thursday afternoon, a weak shortwave will be approaching from the northwest as the weak boundary pushes back north as a warm front by Thursday afternoon. Highs for Thursday will be from the lower to middle 90s. Heat indices will push to around 100 degree mark in the south and west./17/ Thursday night through Tuesday: At the beginning of the period, surface high pressure over the lower MS valley will be in the process of being replaced by yet another from the north in continued mid level northwest flow. For the most part, surface dewpoints will remain in the 60s late week into the first part of the weekend. These conditions will allow for efficient warming and deep mixing, but heat indices should not be much of a problem. This will begin to change somewhat Saturday afternoon and Sunday afternoon over the south as dewpoints begin to creep back into the lower 70s. With the expected heat in the lower 90s, heat indices will climb to near 105. Meanwhile, a long wave trough will begin dropping south through the upper MS valley Sunday with its attendant cold front close enough by Monday for widespread showers and thunderstorms to develop mainly during the heat of the day Monday. Not much eastward progression looks to occur as the trough continues to dig south Tuesday into Wednesday. With the front essentially stalling from northeast to southwest over the area, good coverages of mostly diurnal convection should continue through the end of the period./26/ && .AVIATION... 00Z TAF discussion: VFR conditions are expected to continue through tomorrow. There may be a brief period of MVFR vis reduction in the Delta tomorrow morning thanks to patchy fog but otherwise, this should not pose much of an issue for aviation interests. /28/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 68 92 71 94 / 0 0 2 8 Meridian 68 93 71 95 / 0 0 3 8 Vicksburg 68 93 71 94 / 0 0 2 9 Hattiesburg 69 93 72 95 / 1 1 4 14 Natchez 68 94 71 94 / 0 1 2 9 Greenville 68 93 71 89 / 0 0 3 23 Greenwood 67 91 70 90 / 0 0 2 20 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$ DL/17/26/28
Area Forecast Discussion
National Weather Service Jacksonville FL
1005 PM EDT Wed Jul 25 2018 .UPDATE... Convection along the Altamaha River should dissipate by midnight. The HRRR is very insistent upon bands of convection moving out of the Gulf of Mexico and across the Florida Peninsula generally south of State Road 16. As there is convection over the Gulf west of Tampa and with the general flow in alignment with the HRRR have added 30-40 percent pops across the Florida Peninsula overnight. && .AVIATION...Overall have kept convection away from the fields overnight but the mid shift may have to amend for Gainesville and St Augustine. Overall VFR conditions overnight. && .MARINE...Upper system over the area will gradually weaken during the remainder of the week, and will be replaced by an upper level ridge of high pressure over the weekend. The result will generally be a persistent south to southwest flow at 10 to 15 knots, with 2 to 4 ft seas through the upcoming weekend. Rip Currents: Moderate risk through Thursday. && .PRELIMINARY POINT TEMPS/POPS... AMG 90 73 91 73 / 40 20 40 20 SSI 88 77 89 77 / 40 20 30 10 JAX 90 74 91 74 / 50 20 40 10 SGJ 88 75 89 74 / 60 20 50 10 GNV 89 73 89 73 / 60 30 60 20 OCF 88 74 88 73 / 60 40 60 20 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$ Sandrik
Area Forecast Discussion
National Weather Service Medford OR
455 PM PDT Wed Jul 25 2018 Updated aviation discussion. .DISCUSSION...25/12Z NAM/GFS/EC in. Lots of marine stratus over the coastal waters this afternoon, along with a lot of smoke over much of the inland portions of the CWA. Cumulus is popping up over the ridges from the Cascades east, and Siskiyous south, but development is less than it was at this time yesterday. The southwestern high continues to retrograde. It will be centered near Las Vegas later today, and it will remain in place there through Monday. This is significant in that the four corners position is the favored location for monsoonal moisture to be advected from the south into the Medford CWA, thus allowing thunderstorms to develop. A location farther west, such as the one the high will move to later today, will cut off the monsoonal moisture, forcing it to the south and east of the Medford CWA. Before that happens, there will be one more round of isolated thunderstorms this afternoon and evening, and the main axis of activity will from central Siskiyou county east into Modoc county, and barely into southern Klamath and Lake counties. No thunderstorms are expected from Wednesday night through early next week. It`s still going to be very hot inland though. Highs will be near 15 degrees above normal over the west side and 5-10 degrees above normal east of the Cascades. The west side may cool a few degrees after Thursday, but highs will remain 10-15 degrees above normal with the exception of the Umpqua Basin, where increasing marine influence will bring a bit more cooling. Temperatures east of the Cascades will continue to be 5-10 degrees above normal. These hot conditions will continue into next week, with some cooling possible next Tuesday into Wednesday. Meanwhile, the marine layer will keep coastal temperatures near normal. Smoke continues to be concentrated to the southeast of the ring of fires in northwest Josephine and northern Jackson Counties. Northwest winds will continue to drive smoke into Jackson, Josephine, and Klamath Counties primarily, where air quality readings are consistently in the Unhealthy and Hazardous ranges. The hourly HRRR smoke forecast model is showing the persistent pattern of somewhat improving conditions early afternoon when atmospheric mixing begins, followed by a push of heavy smoke into valleys in the late afternoon hours as the daily northwest winds develop. The main determining factor for when smoke diminishes significantly in area valleys is fire activity. Until fire activity diminishes, smoke will likely continue to be unhealthy to hazardous at times. A weak trough will approach the Pacific Northwest coast next Tuesday, and the high near Las Vegas will start to progress eastward again. This may eventually allow monsoonal moisture and thus thunderstorm activity back into the Medford CWA, but at this time it looks like that won`t happen through at least next Thursday. && .AVIATION...For the 26/00Z TAFs...Wildfire smoke continues over most of the inland areas west of the Southern Oregon Cascades as well as some locations just east of the Cascades. MVFR visibilities/cigs and local IFR conditions will prevail over Jackson and Josephine counties with occasional improvement to VFR. Outside of the smoke, VFR conditions will prevail for inland areas. Smoke models keep thick smoke in the Rogue Valley until around 06Z with thick smoke spreading into the Klamath Basin after 03Z. Along the coast, marine clouds are just off the coast. This should return this evening. The TAF shows lowering conditions at 3z, but it could be delayed by an hour or two. Once the lower conditions return, it will continue overnight into Thursday morning. Meanwhile south of Port Orford, marine stratus will likely return again this evening. -FB && .MARINE...Updated 200 PM PDT Wednesday 25 July 2018...Offshore high pressure and a thermal trough inland will persist through this week. There`s good agreement the strongest winds will be around 3nm from shore west of Cape Blanco southeast to around 20 nm west of Pistol River. Even then, were only expecting them to remain small craft. These conditions will persist into Thursday. On Friday, small craft winds and seas may linger, especially from Cape Blanco southward. Then winds and seas will diminish Friday night, with relatively calm conditions Saturday through early next week. -Petrucelli && .FIRE WEATHER...Updated 200 PM PDT Wednesday 25 July 2018... There remains a slight chance for an isolated storm or two in northern California this afternoon and evening. We`re expecting storms to form around eastern Siskiyou County and head eastward towards Modoc County. The lightning activity will be significantly less compared to the last two days. For Thursday, breezy winds and dry RH`s will contribute to an elevated fire weather risk during Thursday afternoon and early evening. Model guidance is suggesting a Red Flag warning for parts of the Rogue Valley and the northern sections of the Illinois valley near Grants Pass. Given the wind guidance and our local statistical guidance for RAWS sites, we went with a red flag warning for a large portion of FWZ 622 and FWZ 620. See the Red Flag warning or our detailed hazards page for more details on locations. Friday is looking similar to Thursday as the pressure gradient between Roseburg and Montague is about 5.5 mb, which is very close to what will occur Thursday. However, with relatively cooler temperatures and thus lower mixing, RH`s should trend upwards. So there is some concern about fire activity on Friday, but it should be trending downward compared to Thursday. After looking through the extended forecast, this hot and dry pattern will likely continue up to Monday when a trough moves in off the coast of Oregon. This has been identified as a critical fire weather pattern because the trough is helping replace a stagnant dry airmass. -Smith && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Heat Advisory until 11 PM PDT Thursday for ORZ024-026. Red Flag Warning from 2 PM PDT through 7 PM PDT Thursday for ORZ620-622. CA...Heat Advisory until 11 PM PDT Thursday for CAZ080>082. Pacific Coastal Waters...Small Craft Advisory until 11 PM PDT Thursday for PZZ356-376. Small Craft Advisory for hazardous seas until 11 PM PDT Thursday for PZZ356-370-376. $$ 15/15/10
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
936 PM EDT Wed Jul 25 2018 .SYNOPSIS... A stationary boundary will linger over the middle of the state into this weekend, lifting to the north early next week. High pressure will remain anchored over the offshore waters into next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 935 PM Wednesday...Another band of showers and thunderstorms producing a few heavy downpours and frequent lightning is moving across the southern zones at late evening. Some additional thunderstorms were observed in the Wilmington area. Latest HRRR and NSSL WRF models continue to show some redevelopment of showers/storms along the coast late tonight into early Thursday morning. Given deep instability and moisture, will keep a 30-40 percent PoPs going overnight. Muggy southwest flow will keep low temperatures in the low to mid 70s for most areas tonight. A few patches of fog or stratus may occur if some clearing occurs given light winds and a wet ground. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... As of 315 pm Wed...Summertime pattern returns. Scattered convection possible off the coast in the morning, then transition to scattered inland convection in the afternoon. Highs will be in the upper 80s inland to mid 80s Outer Banks and south coast. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... As of 245 AM Wed...Models remain in good agreement with the typical summertime pattern. More active weather may move back in for the weekend into early next week. Thursday night through Friday...Only isolated to scattered convection mainly during the afternoon hours Fri. Highs more typical for the peak of the summer in the upper 80s to around 90 interior to mid/upr 80s coast. Lows in the lower to mid 70s. Saturday through Tuesday...25/00Z med range model suite in fairly good agreement with broad upr trough amplifying across the Great Lakes region and digging into the lower MS River Valley this weekend, with sfc front sagging south into the Mid Atlantic to Southeast states. It appears front will remain north and west of E NC, though hts fall enough to warrant somewhat better chances of showers/storms for the weekend into early next week as afternoon/evening convective coverage will be a bit more widespread, esp for interior zones. Afternoon highs knocked back a few degrees generally into the mid/upr 80s most areas. Overnight lows still seasonably warm in the 70s. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... Short Term /through 00Z Friday/... As of 640 PM Wednesday...Some MVFR ceilings being observed in convection at KOAJ, which may impact the other TAF sites over the next 2 or 3 hours. Would anticipate this activity to wane with loss of heating. While expect mostly VFR conditions through this TAF cycle, will continue previous trend of showing a period of MVFR ceilings early in the morning at the TAF sites as skies clear somewhat with a rather wet ground from recent days of rainfall. VFR conditions should prevail during the day Thursday with mostly a mid-cloud deck expected. Long Term /Thu Night through Sunday/... As of 245 AM Wed...A return to mainly VFR Thursday Night through Friday as typical summertime pattern returns with just scattered to isolated showers/storms each afternoon. Perhaps better chance of lowered vsbys/cigs this weekend as better chances for showers/storms moves in. && .MARINE... Short Term /through Thu/ As of 935 PM Wednesday...No major changes to the current forecast. S/SW winds will continue at 15-25 knots over the coastal waters tonight, and may be enhanced at times by convection. Winds on the Pamlico Sound will run 15-20 knots. Elsewhere, mostly 10-15 knot winds are expected. Seas are running 4-6 feet current and that should continue overnight. Winds and seas subside from north to south early Thursday into Thursday afternoon as high pressure offshore becomes predominant. Long Term /Thursday night through Sunday/... As of 245 AM Wed...Winds and seas diminish Thu night into next weekend with shift to more typical mid-summer Bermuda high pattern with SW winds 5-15 kt. Seas will generally be 3-5 ft through Sat then 2-4 ft by Sunday. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...Beach Hazards Statement through Thursday evening for NCZ095- 098-103-104. MARINE...Small Craft Advisory until 2 PM EDT Thursday for AMZ154-156- 158. Small Craft Advisory until 6 AM EDT Thursday for AMZ150. Small Craft Advisory until 11 AM EDT Thursday for AMZ152. && $$ SYNOPSIS...HSA NEAR TERM...CTC SHORT TERM...HSA LONG TERM...TL AVIATION...CTC/TL/MS MARINE...CTC/HSA/TL
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1102 PM CDT Wed Jul 25 2018 .Updated for 06Z Aviation Discussion... Issued at 1055 PM CDT Wed Jul 25 2018 && .SHORT TERM...(This evening through Thursday) Issued at 237 PM CDT Wed Jul 25 2018 As of early this afternoon, a cold front stretched southwest to northeast across western MN, already having moved through Alexandria and quickly approaching the St. Cloud area as it moves southeast. Some clearing today has helped steepen low level lapse rates and latest RAP analysis and forecast indicates 1,000-2,000 j/Kg of CAPE along and south of the front through the afternoon. A few very spotty cells are beginning to break out across southern and central MN in the warm sector where temperatures are in the mid to upper 70s with dew points in the mid 60s. Expecting additional thunderstorm development through the afternoon, but an analysis of model soundings indicate a long skinny-CAPE setup with mainly speed shear, but a lack of directional shear. The slight risk area clipping far eastern MN and western WI still looks to be our best bet to get strong storms as the afternoon wears on with more time to destabilize in the warm sector. The skinny CAPE and unidirectional deep shear environment will produce scattered thunderstorms along the front through the afternoon, but most storms should be sub-severe. A few strong storms would pose a risk of damaging winds, and possibly large hail. The front will clear the area from west to east, with clearing skies likely tonight behind the front. Cold air advection will ensue for Thursday, with a stratocu deck expected to drop in from the north as we remain in deep cyclonically curved flow on the west side of the deep upper trough. Highs tomorrow will be held in the upper 60s to low 70s with northwest winds of 10-20 MPH. .LONG TERM...(Thursday night through Wednesday) Issued at 237 PM CDT Wed Jul 25 2018 Quiet & pleasant to start of the long term period with a broad area of high pressure across the northern plains & northwest flow aloft keeping our temperatures a few degrees below normal & skies, for the most part, sunny. Can`t rule out some precip chances Saturday & Sunday as the jet aloft pivots over the area & cooling temperatures aloft allows for some diurnally-driven scattered showers & thunderstorms. Chances look a little better on Sunday afternoon compared to Saturday as a bit more of an organized vorticity maxima passes over the area. Regardless, expect most areas to stay dry for most of the the weekend given the scattered coverage so expect a cooler & partly sunny weekend, but be prepared for a passing shower or two. Beyond the weekend, we remain under the deep upper-level trough over the Great lakes with 500 mb heights on the order of 2 standard deviations below the mean for late July/early August. A few perturbations aloft will continue to pass overhead & potentially kick off a few scattered showers & thunderstorms each afternoon but otherwise things are expected to stay dry. Temperatures slowly rebound back into the mid-80s by Wednesday as the ridge over the southwest begins to build back into the upper Midwest. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1055 PM CDT Wed Jul 25 2018 VFR conditions overnight, but should see clouds move in from the north. Should see MVFR clouds by morning, and these will gradually lift throughout the day, but cold air advection will keep cloud bases from rising too quickly. By mid to late afternoon most sites should be above 3000 ft with overcast skies. Northwest winds will gust near 20kts on Thursday, but taper off again after sunset. KMSP... VFR conditions should give way to MVFR by morning, but cloud bases are expected to remain above 1700 ft. Should see VFR conditions by the afternoon as cloud bases lift throughout the day. /OUTLOOK FOR KMSP/ FRI...VFR. Wind NW at 05 kt. SAT...VFR with small chance of -shra. Wind VRB at 05 kt. SUN...VFR with small chance of afternoon -shra. Wind NW at 05 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...SPD LONG TERM...ETA AVIATION...jrb
Area Forecast Discussion
National Weather Service Phoenix AZ
230 PM MST Wed Jul 25 2018 && .SYNOPSIS... Excessively hot weather will continue for a few more days with near record highs for many locations. Moisture will slowly move back into the region allowing temperatures to eventually retreat back to near normal levels by the weekend. In addition, more expansive thunderstorms will begin over higher terrain areas of Arizona, then gradually spread towards lower elevation communities during the weekend and early next week. && .DISCUSSION... Another day of excessive heat across the region, with very strong ridging aloft (500 mb heights upwards of 600dm). So far, the high at Sky Harbor has been 115F, with another degree or two possible rise before the final high is reached. Current 88-D radar and satellite imagery is showing convective development over the higher terrain to our north. The last several runs of the HRRR High-res model showing, under light northwesterly flow aloft, the current convection over Yavapai County attempting to make a run towards the lower deserts. However, a rather hostile environment over the lower deserts (rather low MUCAPES (just a couple of hundred J/KG), high CIN, and a mid- level cap will likely kill the storms before they reach the lower deserts. However, there is a slight chance that they could affect parts of extreme northern Maricopa County and La Paz County before they dissipate. More likely, outflows from these storms will push into the lower elevations, producing gusty winds and a few areas of blowing dust this evening. Southern Gila County will likely also see isolated storms, especially over the higher elevations. Gusty winds and brief heavy rains will be the primary threat, given the high DCAPE values (in the 1000-2000 J/KG range). .PREVIOUS DISCUSSION... Thereafter tonight, it still appears very likely a deeper, more pronounced Gulf surge will spread through SW and south-central Arizona with low/mid 60 dewpoints pushing all the way into foothill locations north and east of Phoenix Thursday morning. If the forecast Sonoran convective complex is strong enough, it is possible gravity wave/outflow influences could once again spark elevated morning storms somewhere through central Arizona Thursday though these mesoscale details are impossible to pinpoint at this time. More importantly, the increased moisture (along with some presumed more prevalent mid/high clouds) will diminish the most extreme heat, however winds trajectories indicate the plume of moisture influence only from SW Arizona through the Phoenix vicinity. Thus, excessive heat will continue through much of SE California and west central Arizona Thursday where high temperatures in excess of 115F will continue for communities such as El Centro, Blythe, and Parker. More pronounced outflows and an increasingly higher theta-e airmass from convective complexes over Sonora and SE Arizona should progressively feed into central and western Arizona beginning Thursday night, but really becoming more apparent Friday night. There is already some model guidance suggesting more organized, stronger outflows blasting into the eastern and southeast part of the CWA Friday evening (i.e. classic blowing dust generation area) though an initial lack of better quality moisture may preclude much actual thunderstorm activity at lower elevations. Other than the potential for dense dust, this outcome will be welcome in further reducing excessive temperature levels, though it is conceivable areas of SE California further removed from the outflow could experience yet another day of excessive heat Friday. This evolution will set the stage for a more convectively active period through the weekend, and 00Z GFS output along with some local high resolution data indicate much more expansive, stronger storms Saturday afternoon/evening. Conceptually given the pre-exiting steep lapse rates and higher DCape values, strong storms would be preferred into lower elevations initially with a greater wind and dust threat. Each successive day would add more moisture to the environmental profile yielding a higher flood threat (and especially given the weaker steering flow near the high pressure center), yet still maintaining these other thunderstorm hazards. Undoubtedly, there will be at least one very active day/evening (potentially Saturday) followed by some less active days through the weekend and early next week time frame. && .AVIATION... South-Central Arizona including KPHX, KIWA, and KSDL: Confidence is increasing that a strong outflow boundary will approach from the north later this afternoon, given the high coverage of storms expected across the higher terrain north of Phoenix. Timing of this boundary as always is uncertain, but the current best estimate is between 00-01Z across the Phoenix area. Gusty winds nearly out of the due north can be expected if this boundary materializes, with occasional gusts to 20-25 mph anticipated. Currently not expecting any thunderstorm activity near area terminals due to the very dry low-level air in place, but will continue to monitor short-term trends and update as necessary. Otherwise, west winds should predominate at KPHX throughout the TAF period, with low confidence in a switch out of the east. Higher confidence this will occur at KIWA overnight. Could see cigs lower to around 15 thousand feet overnight at all area terminals in association with thunderstorm activity over the higher terrain, before gradually improving by mid-late Thursday morning. Southeast California/Southwest Arizona including KIPL and KBLH: There are no major aviation weather concerns through Thursday morning. The winds will maintain a more southerly component at KBLH while more southeasterly for KIPL. Aviation Discussion not updated for amended TAFs. && FIRE WEATHER... Saturday through Wednesday: Storm chances will increase over the weekend and through the first part of next week with activity gradually spreading into lower elevation districts. Temperatures will finally cool to a near seasonal average over the weekend. Correspondingly, minimum humidity levels will increase towards a 20-35% range while overnight recovery becomes good. Somewhat elevated and gusty south to southwest winds on Saturday will relax thereafter becoming more typical of the monsoon season next week. && .CLIMATE... Record high temperatures: Date Phoenix Yuma ---- ------- ---- July 25 115 in 1943 120 in 1943 && .SPOTTER INFORMATION STATEMENT... Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...Excessive Heat Warning until 8 PM MST this evening for AZZ531- 532-534>556-559>562. Heat Advisory until 8 PM MST this evening for AZZ557-558-563. Excessive Heat Warning until 8 PM MST Thursday for AZZ530-533. CA...Excessive Heat Warning until 8 PM PDT this evening for CAZ564- 565. Excessive Heat Warning until 8 PM PDT Thursday for CAZ560>563- 566>570. && $$ DISCUSSION...Percha/MO AVIATION...Rogers/Kuhlman FIRE WEATHER...Percha/MO CLIMATE...MO
Area Forecast Discussion
National Weather Service Pueblo CO
723 PM MDT Wed Jul 25 2018 .UPDATE... Issued at 716 PM MDT Wed Jul 25 2018 Quick update was done to pull down severe watch #307 for Teller and El Paso counties. Latest high res model runs suggest another round may move into the Pikes Peak region between 03-06z...though best instability and threat area may end up being farther to the east. Will continue to monitor this potential through the evening, but for now have let the watch expire. -KT && .SHORT TERM...(This evening through Thursday) Issued at 342 PM MDT Wed Jul 25 2018 Currently...Cold front moved into the area somewhat quicker than the models suggested, likely due to the convection earlier this morning over Nebraska. Showers and thunderstorms are developing over the eastern mountains. .Tonight and Thursday...Trough will pass to our north and east this evening. High resolution models continue to show stronger convection developing over El Paso and Teller Counties later this afternoon into the evening. There is enough shear and instability to get a few strong to severe storms in El Paso Counties early this evening. As disturbance moves southeastward, anticipate storms will develop in the evening over Kiowa County and move to the southeast. Still currently looks like best chances for stronger storms will be north and east of a line from Colorado Springs to Lamar. Latest HRRR suggest some of the storms could move into Baca County later tonight with additional rainfall. .Thursday...Another day with plenty of low level moisture on the plains and eastern mountains. The GFS and NAM are focusing on the strongest storms to be along the eastern mountains and near the Interstate 25 corridor. SPC has marginal risk for these region which is reasonable given the shear and marginal CAPE. Main threats will be locally heavy rains, and will have to watch the recent burn scars. Further west, still enough monsoon moist for diurnal convection but main monsoon plume will be south of the region. .LONG TERM...(Thursday night through Wednesday) Issued at 342 PM MDT Wed Jul 25 2018 .Friday through Sunday...Continued generally wet pattern for the eastern mountains and eastward with low level moisture remaining on the plains. Cold frontal passage on Saturday will bring in another surge of low level moisture. On Sunday, a sharper trough will move over the region with another cold front bringing in more low level moisture. There could be increased chances for severe weather on Sunday with increased shear, forcing and low level moisture. Still to early to be very specific as many finer details have yet to be resolved. Further west, still some monsoon moisture wrapping around the upper high for some scattered diurnal convection. .Monday through Wednesday...Upper ridge retrogrades with drier northerly flow aloft developing. In addition, better low level moisture will move east and south of the region. Grids have a general drying trend with some residual monsoon moisture producing some diurnal convection. --PGW-- && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 342 PM MDT Wed Jul 25 2018 Some thunderstorms will continue through mid evening at the TAF sites with the best chances for storms at KCOS. The storms near KCOS could be strong. On Thursday, the pattern continues with better low level moisture at KCOS and KPUB. Models suggest more TSRA at KCOS and KPUB than what occurred on Wednesday, while coverage at KALS will be similar to Wednesday. _PGW-- && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 342 PM MDT Wed Jul 25 2018 Some thunderstorms will continue through mid evening at the TAF sites with the best chances for storms at KCOS. The storms near KCOS could be strong. On Thursday, the pattern continues with better low level moisture at KCOS and KPUB. Models suggest more TSRA at KCOS and KPUB than what occurred on Wednesday, while coverage at KALS will be similar to Wednesday. _PGW-- && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KT SHORT TERM...PGW LONG TERM...PGW AVIATION...PGW
Area Forecast Discussion
National Weather Service Raleigh NC
1013 PM EDT Wed Jul 25 2018 .SYNOPSIS... An upper level trough will drift east across the Appalachians tonight, then reach the East coast by Thursday afternoon. A surface trough will otherwise linger over the Carolinas ahead of a cold front that will settle into, then become quasi-stationary over, the southern middle Atlantic states this weekend. && .NEAR TERM /TONIGHT/... As of 1010 PM Wednesday... WV satellite imagery indicates the mid-upr low that for days had been situated over the sern US, has deamplified into the nrn middle Atlantic states, downstream of an upr level, full latitude ("kicker") trough analyzed in 00Z upr air data from near Hudson Bay swd into the srn Appalachians and nern Gulf of Mexico. That upr level trough will move ewd into the cntl Carolinas by 12Z Thu. At the surface, a remnant frontal zone, and persistent trough/convergence axis and approximate wrn bound of a richer maritime Tropical airmass characterized by surface dewpoints aoa 70 degrees, was analyzed at 02Z from near CHO swd to GSO and CLT, then swwd across cntl GA and srn AL. This feature is expected to remain quasi-stationary overnight. The combination of subsidence behind the ejecting wave over the nrn middle Atlantic states, and widespread convective overturning from the earlier multi-cell convection and composite outflow that has since moved to the NC coast, has resulted in mainly dry conditions over cntl NC this evening. However, weak instability and CINH --the former around 1000 J/kg or less per both the observed 00Z GSO RAOB and RUC objective analysis data-- suggests a few showers may yet percolate over cntl NC tonight, particularly in the vicinity of the aforementioned lingering surface front/trough, as the upr level trough axis approaches. Lingering mid-high level cloudiness, mostly remnants from earlier convection, should continue to thin overnight. That (at least) partial clearing, in conjunction with abundant low level moisture from both saturated soil and the aforementioned, remaining maritime Tropical air, will favor the development of fog and low clouds late tonight-Thu morning. It will otherwise be a muggy/humid night- morning, with lows in the upr 60s to lwr 70s. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... As of 345 PM Wednesday... Drier air will finally start to move into the area Thursday as the upper level trough axis that has been over the region for the last couple of days collapses. As this happens PWATs across the western zones will fall to around 1.25" (on the GFS and NAM) while around 1.7" towards our eastern zones. A surface front will also stall across the triad during the afternoon while a sea breeze works inland from the coast. The high res are showing scattered convection at best across our eastern counties. Thursday night the front will wash out with southerly flow returning to all TAF sites. Thursday night the area will remain precipitation free. && .LONG TERM /FRIDAY THROUGH TUESDAY/... As of 245 PM Wednesday... A brief reprieve from at least widespread POPs is expected to continue on Friday as NC finds itself in the subsidence region of a departing area of low pressure riding North along the DELMARVA Peninsula. This break won`t last long, however, as an upper level trough begins to dig south/east through the Ohio Valley with its associated cold front arriving on our northwestern doorstep by Friday evening. This front is likely to stall somewhere over central NC over the weekend, before moving north as a modified warm front Sunday night/Monday. Behind the boundary, the sub-tropical high is expected to strengthen and build west as the trough remains just west of our area, providing enhanced southerly/southwesterly flow into the region through at least midweek. This will help build an airmass characterized by 1.75 to 2.5 inch PWAT values over the Coastal Plains of the Mid Atlantic ahead of an approaching cold front likely to push in before stalling across central NC through the middle of next week. In short, expect the wet weather pattern to once again return, with at minimum CHC/LKLY POPS for much of next week. Thicknesses look to remain near/slightly below normal through the period. The warmest days will likely occur on Friday/Saturday, with afternoon highs generally in the upper-80s to low-90s. A bit cooler next week thanks to abundant moisture/cloud cover/precipitation. Overnight lows will settle into the low 70s. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... As of 830 PM Wednesday... Showers and storms have decreased in coverage and intensity this evening will the loss of heating. However, scattered showers and isolated storms will continue to be possible through mid/late evening, before dry weather is expected by early Thursday morning as the mid level trough axis begins to shift eastward and slowly into the region. With light and variable to calm winds expected, coupled with clearing skies overnight sub-VFR visbys (generally MVFR/IFR) will be possible in the 8-12Z time frame, with possibly some low status across far east/southeastern central NC (KFAY stands the best chance of seeing some IFR/LIFR cigs). VFR conditions are expected to return by at least mid/late morning (lingering the latest into the morning at KFAY). Thursday afternoon much drier air will work into the western taf sites with PWATs falling to around 1.25". Across the eastern TAF sites dry air will filter in, but PWATs will only fall to around 1.70". Due to this think primary area for precipitation will remain across the eastern TAF sites Thursday, though coverage is expected too low to included any mention in the TAFS at this time. Outlook: Generally VFR conditions are excepted, with a chance of mainly afternoon and evening storms Sat. through Mon., increasing in coverage each day. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...MWS NEAR TERM...MWS SHORT TERM...HAINES LONG TERM...MORROW AVIATION...BSD/HAINES
Area Forecast Discussion...UPDATED
National Weather Service Tampa Bay Ruskin FL
824 PM EDT Wed Jul 25 2018 .UPDATE... The upper-level trough over the Florida Peninsula will lead to a persistent SW Flow overnight and into the day tomorrow. Based on UA data from the 00Z balloon launch and current HRRR forecasts overnight, showers and possibly some thunderstorms remain in the forecast overnight. Accordingly have adjusted POPs grids a bit to reflect higher rain chances mainly from Tampa Bay northward for the overnight hours across the region. Have allowed the rip current advisory to expire as winds tomorrow will be a bit lighter tomorrow reducing the risk somewhat across area beaches. Temperatures once again will be warm with overnight lows in the middle to upper 70s...near 80 along the immediate coast. && .AVIATION... VFR expected through much of the period with persistent SW wind regime. Winds overnight may become a bit more southerly near the coast at times however. Overnight, showers will push onshore mainly from Tampa Bay north so will keep VCSH in the forecast overnight. During the afternoon hours Thursday SW winds around 10 knots expected although winds could become gusty at times, perhaps approaching 20 knots, especially at PIE and SRQ. && .MARINE... A ridge of high pressure tracking from south to north of the waters through the period with prevailing winds shifting from southwest and west to southeast to east. Although onshore winds are expected to set up in afternoon seas breezes during the weekend and early next week...when the ridge axis is north of the waters. Wind speeds generally benign however they...along with seas...will be higher in and near thunderstorms. && .Preliminary Point Temps/PoPs... TPA 78 89 78 90 / 40 50 30 30 FMY 77 92 78 91 / 30 30 10 60 GIF 76 91 76 92 / 20 60 10 50 SRQ 79 89 79 89 / 30 50 20 30 BKV 75 89 74 90 / 40 50 20 30 SPG 79 88 79 90 / 40 50 30 30 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...Beach Hazards Statement through Thursday evening for Coastal Charlotte-Coastal Lee-Coastal Sarasota. Gulf waters...None. && $$ UPDATE...Flannery AVIATION/MARINE...11/McKaughan UPPER AIR...27/Shiveley DECISION SUPPORT...24/Hubbard