Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/11/17

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
738 PM MDT Thu Aug 10 2017 .UPDATE... We coordinated with SPC and have agreed to drop Severe Thunderstorm Watch 446 for northeast NM. Zones will be updated shortly. CHJ && .PREV DISCUSSION...545 PM MDT Thu Aug 10 2017... .AVIATION... 00Z TAF CYCLE SCT to ISOLD showers and thunderstorms will generally move toward the east/northeast around 10-20 mph through much of the night. Storms across the NE will be capable of large hail and damaging winds with an ISOLD tornado threat. Cells will probably cluster this aftn and evening, and an organized line of storms will be possible across the NE. A back door cold front will push southwestward through the E plains tonight into Friday morning, allowing low clouds with IFR and MVFR conditions into the NE quarter of the state. Greatest confidence in TAF site flight category restriction is at LVS Friday morning, with less confidence at TCC. Storms will increase in coverage on Friday with locally heavy rain and wet microbursts likely with low clouds and reduced visibilities. 40 && .PREV DISCUSSION...310 PM MDT Thu Aug 10 2017... .SYNOPSIS... Showers and thunderstorms will become more widespread and active Friday and through the weekend before some drying pushes into west central and northwest New Mexico early to mid next week. A few strong to severe storms with large hail and damaging wind gusts are most likely late this afternoon and evening over portions of northeast New Mexico. Locally heavy rain on Friday, which could result in flash flooding, may be most likely along portions of the central mountain chain, Northeast and Central Highlands and the East Central Plains. High temperatures for the next several days will be near to below average while overnight lows will be near to above average. && .DISCUSSION... Sure doesn`t seem like the monsoon season with the recent bouts of severe weather and the ongoing SPC outlook, which still has the marginal/slight risk area painted over Union, and the majority of Catron and Harding counties through this evening. Sfc front/outflow boundary forecast to surge into the northeast, but latest HRRR has delayed it until 00Z or after. This seems reasonable as convective development just starting to get frisky over ne NM and over se CO. Given the placement of forecast rainfall and surface gradient, not suspecting there will be much of an east wind, if any, into the middle/lower RGV tonight. May have to watch the southeast tonight, if the boundary is driven farther south because the inherited minimal to nil pops were left in that region. The upslope flow associated with the boundary sets the stage for a more active Friday/Friday night, and potential for heavy rain over portions of the central mt chain, Northeast and Central Highlands and East Central Plains, where theta-e values increase significantly. Severe storms are not in the outlook though. Did up pops to match the guidance consensus. The far southeast and far northwest may be the areas which are least likely to receive decent rainfall. Lowered high temperatures Friday for parts of the northeast, although did not go as cool as the MET guidance. Saturday and Sunday look active also with a rather flat H5 ridge in place. Another front may impact the northeast Sunday night and again Monday night. Some drier air may push into west central and northwest New Mexico next Tuesday/Wednesday to trim rain chances there. High temperatures the next 7 days will be near to below average, with lows near to above average. && .FIRE WEATHER... The mid-level high pressure system will migrate southeastward over south TX today, allowing a more traditional flow of monsoon moisture to stream north and northeastward over the forecast area. A couple of moist back door cold fronts area also expected to dive south southwestward through the eastern plains: one tonight and the other Sunday night. An uptick in the coverage and wetness of showers and thunderstorms is expected to begin Friday, with scattered to numerous showers and thunderstorms expected each afternoon and evening through Monday. With PWATs in the 1-1.6 inch range on Friday, that day should be the wettest day overall, and Monday looks to be a close second if Sunday night`s front comes in wet enough. With all the moisture and some cool air advection with the fronts, high temperatures will vary from near normal to several degrees below normal Friday through Monday. Haines will vary around 3 through this period. There will also be areas of poor ventilation Friday and Saturday, but probably some improvement Sunday before vent rates fall again on Monday. An upper level trough approaching from the west will steer drier air into the state from the west and southwest Tuesday through the middle of the coming work week. The coverage and wetness of convection will decrease with each day, and there will be a resulting increase in high temperatures. Ventilation will probably also improve, though some stubborn pockets of poor may linger over southwest areas. Haines around 5 are expected across northern areas Tuesday and Wednesday. && .ABQ WATCHES/WARNINGS/ADVISORIES... None. && $$ 40
Area Forecast Discussion
National Weather Service Birmingham AL
729 PM CDT Thu Aug 10 2017 .UPDATE... For 00Z Aviation. && .SHORT TERM... This afternoon and Tonight. As expected, the convective activity this afternoon has been concentrated over western Alabama, along the leading edge of an MCV, and along the Gulf Coast associated with the sea-breeze. The HRRR model has had a good handle on the areal coverage but is lagging in time by several hours. This models has these two areas coming together into one concentrated mass of convection this afternoon and tracking eastward across areas mainly along and south of I-20. Highest pops this evening will be along and east of I-65, with only a few showers remaining by midnight. Could see some locally heavy rainfall over the southern counties as the slower moving seabreeze storms interact with the MCV storms. 58/rose .LONG TERM... Friday through Wednesday. The original weakening surface boundary is expected to be well to our north on Friday. We should keep weak onshore flow around the Atlantic ridge/or around weak ridging in the Northeast Gulf over the weekend. A surface front approaches the Deep South on Friday, but is not expected to make progress into Alabama over the weekend as the main low over the Great Lakes pulls off to the east quickly taking the main energy with it and leaving the approaching front stalled well to our north. In the upper levels on Friday, we have a first angled then flattening elongated ridge over the southern third of the U.S. centered over Texas with W/NW then more zonal weak flow across C AL. We should continue with a daily bombardment of disturbances to enhance our convective activity. By the beginning of next week, an upper trough tries to digs across Eastern Conus and should help to push a surface ridge southward across the same area to nudge the stalled front into the N/NE portions of the CWA as a back door front during the first half of next week. Some lower temperatures/dew points could drift into the NE counties by the middle part of next week to round out the forecast and would lower rain chances in the NE as well. 08 && .AVIATION... 00Z TAF Discussion. Have re-introduced IFR/LIFR mention at the terminals overnight. Additionally, showers and thunderstorms have developed late this afternoon and will continue a few hours at minimum this evening. The low clouds hung around parts of central Alabama until almost mid day, this delayed the instability realization across the area. Therefore, showers and thunderstorms are develop and continuing this evening along these boundaries and what appears to be a remnant sea breeze. Mentioned thunder at most sites through 03z. The ceilings/vis will be briefly impacted and may last longer than mentioned if merging of boundaries takes place. With southerly flow in the low levels overnight, expect low clouds to develop after 09z. The IFR/LIFR period appears to be from around the 09-14z time frame. Heating should bump these clouds to MVFR by 16-17z and VFR by afternoon. Did not mention any weather tomorrow after 18z, but thunderstorms much like the previous several days are expected. fog does not appear to be the main issue but will monitor the latest developments. **Note...had some technical issues with the TAF issuance this evening. The forecast is now out and under corrected. Sorry for this inconvenience. 75 && .FIRE WEATHER... Above normal rain chances are expected through the weekend. There are no fire weather concerns. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 71 87 72 88 71 / 50 60 40 40 40 Anniston 72 86 72 87 72 / 60 60 30 50 30 Birmingham 72 87 74 89 73 / 50 60 30 50 30 Tuscaloosa 73 88 74 91 74 / 30 60 30 50 30 Calera 72 88 73 89 73 / 50 60 30 50 30 Auburn 72 87 73 88 73 / 60 60 30 50 30 Montgomery 74 90 75 91 75 / 60 60 30 50 30 Troy 73 88 73 90 73 / 60 60 20 50 30 && .BMX WATCHES/WARNINGS/ADVISORIES/... None. && $$
Area Forecast Discussion
National Weather Service El Paso Tx/Santa Teresa NM
345 PM MDT Thu Aug 10 2017 .SYNOPSIS... Isolated to scattered thunderstorms will be most pronounced over the higher terrain of the Gila Region, Sacramento Mountains, and New Mexico Bootheel this evening, with a few strays elsewhere. Thunderstorms may last a little longer into the evening over Southwest New Mexico as they move north from the Sierra Madres. An upper level disturbance will move across the area Friday night, resulting in scattered thunderstorms across the area. Cloud cover from these storms could linger into Saturday, resulting in cooler temperatures. The overall pattern is favorable for an uptick in thunderstorm coverage through the weekend and early next week. && .DISCUSSION... Water vapor imagery and RAP analysis shows the subtropical ridge has shifted towards east-central NM, with an inverted trough at the mid-levels extending from the northern Baja into the northern Sierra Madre Occidental (SMO). This disturbance is largely convectively-induced from last night`s very impressive MCS over Sonora. The disturbance that initially helped trigger that MCS (an upper-tropospheric inverted trough) is rapidly weakening over southern Baja, but it`s difficult to find unless you do a water vapor loop going back to yesterday afternoon. Regardless, the present inverted trough is having some influence on convection over the northern SMO which is drifting northwards into the Bootheel Region. Otherwise, thunderstorms are generally anchored to the higher terrain in the San Andres and Sacramento Mountains, and is strongest over the higher ranges of the Gila. Steering flow is bringing storms from south to north, while upper level WSW flow is taking the anvil blowoff to the ENE. This should help to allow some scattered storms to work into the lower elevations of SW New Mexico (e.g., Hidalgo and southern Grant Counties) as the storms to the north and south aren`t spewing cirrus ahead of themselves. Elsewhere, expect isolated thunderstorms...including parts of El Paso and Hudspeth Counties where cu is somewhat enhanced. The mid-level inverted trough will continue to move to the northwest overnight, but will decoupling from its reflection higher aloft. NAM/GFS show a strong PV anomaly (strongest at 345K) making its way around the subtropical ridge and into SE Arizona by Friday afternoon, and SW New Mexico Friday night. This may help keep thunderstorms going well into the overnight hours across much of the area Friday. Kept isolated to scattered PoPs going through the night, with the best chances west of the Rio Grande. Leftover clouds/debris will likely impact thunderstorm chances on Saturday, though the overall pattern continues to favor a relative uptick in convection, with mid-level moisture continuing to stream up from Mexico (and maybe even tapping the mid-level moisture remnants of Franklin or whatever it`s E Pacific name ends up being assuming it can reorganize at the sfc). With the risk of enhanced cloud cover/convective debris, I also dropped the Max Temps for Saturday by a few degrees. High "bust" potential with this one if we`re left with a mess of clouds Sat AM. Sunday...the subtropical ridge weakens and spreads out E-W with the axis just south of the border. Any weak westerly disturbances could keep enhancing thunderstorm chances. Next week, the ridge appears to reorganize and re-center itself over south Texas, with southerly flow keeping monsoonal moisture in place over our area. && .AVIATION...Valid 11/00Z-12/00Z... Mostly VFR conditions thru period with the possibility of MVFR near thunderstorms. Generally east to southeast winds AOB 12KTS except gusts to 40KTS possible near thunderstorms. Showers and thunderstorms will be mostly confined to the area mountains with some isolated storms mainly west of a KTCS- KDMN line. Skies generally FEW-SCT070-090 SCT-BKN200-250. && .FIRE WEATHER... Upper high will be shifting into central TX over the coming days which will allow deeper monsoon moisture to return to the region. Expect mainly scattered mountains storms and isolated lowland ones through Friday but as moisture deepens, storm coverage will increase over the weekend and into early next week. Temperatures will also fall to near normal as moisture increases this weekend. Models now showing little movement in the upper high for the later half of next week with moisture plume shifting mainly over the eastern half of the forecast area. Relative humidities through the period will remain above 20 percent with winds generally less than 15 mph except near storms. && .PRELIMINARY POINT TEMPS/POPS... El Paso 76 98 74 94 / 10 0 20 30 Sierra Blanca 70 95 71 92 / 10 0 10 30 Las Cruces 70 95 68 92 / 0 0 30 30 Alamogordo 69 93 68 91 / 10 10 20 40 Cloudcroft 54 73 51 69 / 30 40 30 50 Truth or Consequences 69 94 69 90 / 20 10 30 40 Silver City 63 88 61 83 / 40 50 50 50 Deming 69 96 68 93 / 20 10 40 40 Lordsburg 70 95 68 90 / 30 30 40 40 West El Paso Metro 74 97 72 93 / 10 0 20 30 Dell City 73 98 70 95 / 10 0 10 30 Fort Hancock 76 99 75 95 / 10 0 10 30 Loma Linda 68 91 65 88 / 10 0 20 30 Fabens 75 99 73 95 / 10 0 20 30 Santa Teresa 72 96 71 93 / 10 0 20 30 White Sands HQ 70 95 70 92 / 0 0 20 40 Jornada Range 69 95 70 91 / 10 0 30 40 Hatch 69 96 68 93 / 20 0 30 40 Columbus 71 98 68 93 / 20 0 40 30 Orogrande 72 95 71 92 / 10 0 20 30 Mayhill 58 81 56 78 / 20 30 30 50 Mescalero 58 82 56 78 / 30 40 30 40 Timberon 58 81 55 78 / 30 20 30 40 Winston 60 86 57 82 / 40 40 40 50 Hillsboro 66 92 64 87 / 30 30 40 50 Spaceport 69 95 68 91 / 20 0 30 40 Lake Roberts 59 86 56 82 / 40 50 50 50 Hurley 64 89 62 86 / 30 30 40 50 Cliff 66 94 64 89 / 40 50 50 50 Mule Creek 66 91 63 86 / 40 40 40 50 Faywood 65 91 63 87 / 30 30 40 50 Animas 69 96 67 90 / 40 30 40 40 Hachita 69 96 66 91 / 30 20 40 40 Antelope Wells 68 95 66 88 / 50 20 40 50 Cloverdale 66 91 64 85 / 50 30 40 50 && .EPZ WATCHES/WARNINGS/ADVISORIES... NM...None. TX...None. && $$ 25/26
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
950 PM CDT Thu Aug 10 2017 .UPDATE... Earlier strong thunderstorms to our northwest have dissipated with the loss of daytime heating, leaving behind just some additional high-level cloud cover. Another disturbance pinwheeling around the northern periphery of the mid-level high is lighting up an additional area of convection across the Texas Panhandle and extreme western Oklahoma. This activity will continue to congeal into an MCS overnight and track steadily southeastward towards the Red River. Veering low-level flow will act to protect North Texas from the brunt of this activity as storm-relative convergence is reduced. That said, it appears an outflow boundary may be able to slide into the I-20 corridor on Friday morning, where subtle isentropic upglide may help to spark off a couple showers and a few thunderstorms. The greatest precipitation coverage (40%) is still expected to remain across our northeastern counties, however. Given the aforementioned meager winds and fairly scant elevated instability, we`ve limited thunderstorm wording to "isolated" in this update through Friday morning. A cursory glance at the latest guidance points to the potential for temperatures warming into the upper 90s to near 100 degrees across parts of the region as the surface flow becomes more southwesterly. At this time, it appears that any cloud cover or precipitation of significance may diminish sufficiently during the late morning/early afternoon to allow temperatures to realize this potential in full. Combined with dewpoints in the lower 70s, heat index values of 105-107 degrees appear possible across Central Texas and into the Metroplex. We will, however, defer decision on a two-day heat advisory for the midnight shift as convective trends/outflow potential becomes a bit more clear. Carlaw && .AVIATION... /Issued 634 PM CDT Thu Aug 10 2017/ Scattered thunderstorms are ongoing this hour near Wichita Falls within a zone of very strong heating. This thunderstorm activity appears to be diurnally-driven, and thus should begin to wane here over the next few hours, but will continue to cause issues at the Bowie Cornerpost. We`re also watching a convective segment moving swiftly into the Oklahoma City Metro. With plentiful instability to its south, it`s possible this activity manages to slide south of the Red River later this evening. Recent runs of the experimental HRRR seem to be handling this ongoing convection the best, and lends enough confidence to add in a few hours of VCSH at the Metroplex sites after 05z. That said, recent warming cloud tops indicate an ongoing weakening trend this hour. Another complex of storms is expected to form across the Texas Panhandle and track into Oklahoma overnight, and should gradually head towards the Red River. Veering low-level flow ahead of this feature should keep the brunt of shower/storm activity to the north and east of the TAF sites. However, sufficient lift looks to spread into the I-20 corridor to warrant another period of VCSH towards daybreak on Friday. A brief north wind shift is also expected to accompany this activity as outflow meanders south into the Metroplex. Surface winds will eventually resume out of the southwest by mid-morning. The aformentioned outflow may provide a focus for renewed convective development on Friday afternoon, but confidence in this was too low to specify a period of VCSH or VCTS at this juncture. We`ll continue a one-line TAF at Waco, where southerly winds and VFR conditions are anticipated through the forecast period. Carlaw && .SHORT TERM... /Issued 342 PM CDT Thu Aug 10 2017/ Another hot and muggy day is underway with afternoon heat index values climbing into the 100-104F range. Ample moisture positioned east of I-35 allowed isolated to scattered showers and thunderstorms to develop as convective temperatures were reached. This activity is entirely diurnally-driven and will dissipate with loss of heating. Latest satellite imagery already points toward a downward trend in the vigor of the cumulus field. The greatest remaining instability is across our southeast counties, roughly southeast of Canton to Hearne, where the highest potential for a thunderstorm or two still exists through sunset. Overnight lows will be a few degrees warmer than last night, with urban areas remaining in the upper 70s or even near 80 degrees for overnight lows. The primary focus for the overnight and Friday morning forecast is on convection that is expected to develop in OK later tonight and move ESE. This activity could affect parts of North Texas especially our Red River counties by daybreak, as discussed below. -Stalley && .LONG TERM... /Issued 342 PM CDT Thu Aug 10 2017/ With an upper level high situated across the Texas Hill County, North Texas will continue to be under northwest flow aloft Friday. A shortwave currently over Colorado will continue moving southeast, causing a complex of storms to develop across southwestern Kansas late tonight and continue moving southeast through the night and into tomorrow morning. The main bulk of the precipitation will move across central Oklahoma, leaving North Texas under a chance of showers and thunderstorms Friday morning. As the MCS continues moving southeast, it is possible that it will leave a remnant boundary across North Texas, continuing the opportunities for showers and thunderstorms during the day. Temperatures are expected to climb into the mid to upper 90s during the day Friday. Combined with dew points in the low to mid 70s, heat index values may be between 105-107 across the Dallas/Fort Worth metroplex and the I-35 corridor surrounding the Waco/Temple/Killeen area. Although this may qualify for a Heat Advisory, there is too much uncertainty at this time on whether or not temperatures may be affected by any remaining rain, clouds, or outflow boundaries in the area. If this is the case,forecast temperatures would be a few degrees lower, and in turn, heat index values would decrease.. With little movement in the upper level high across the Hill Country, and upper level disturbances continuing to pivot around it, another complex of storms is expected to develop late Friday night into Saturday morning. The set up will be very similar to Friday morning`s setup, with the main bulk of the precipitation moving across Oklahoma. North Texas will be on the southern fringe of showers and thunderstorms, pushing yet another outflow boundary into our area, acting as a focus for additional convection during the day Saturday. Temperatures will once again climb into the mid to upper 90s across North Texas, with a few locations across Central Texas reaching 100 degrees. Heat index values will once again reach 105-107, mainly across areas south of Interstate 20. The better chances of rain will be late Saturday night into Monday morning as another shortwave makes its way toward North and Central Texas. This will take a slightly more southern track compared to the two previous shortwaves, leading to the bulk of the precipitation moving across Southern Oklahoma and North Texas. Given the amount of rain that fell across the northeastern counties the first half of this week, plus any additional rainfall between Friday and Sunday, forecast rainfall totals will need to be monitored closely. Any persistent heavy rainfall may lead to flooding as soils have slowly become more saturated. There will be additional rounds of rain possible Monday and Tuesday before the center of the upper level ridge moves across Central Texas. This will significantly decrease the rain chances across most of the area, with only the Red River counties under a chance of rain. Hernandez && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 80 98 79 96 79 / 10 20 10 30 40 Waco 77 98 78 100 78 / 5 5 10 5 10 Paris 75 91 74 90 74 / 20 40 40 50 50 Denton 77 97 77 95 76 / 10 30 20 40 50 McKinney 76 96 77 94 76 / 10 30 20 40 50 Dallas 81 98 80 96 80 / 10 20 10 30 40 Terrell 76 96 77 95 77 / 10 20 20 30 40 Corsicana 77 97 77 97 77 / 10 20 10 20 20 Temple 75 98 76 100 76 / 10 5 10 5 5 Mineral Wells 74 98 75 97 76 / 10 10 10 20 30 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$ 90/58
Area Forecast Discussion
National Weather Service Lincoln IL
901 PM CDT Thu Aug 10 2017 .UPDATE... Issued at 900 PM CDT Thu Aug 10 2017 A line of showers and thunderstorms has pushed eastward across the CWA this evening, and was mainly located from about Springfield to Pontiac as of 9 pm, with additional clusters of strong storms in west central Illinois. Warming tops on satellite have correlated to the general weakening trend as of late, although the storms between Quincy and Havana still have a bit of punch to them. The overall weakening will continue over the next few hours as the line pushes toward the I-57 corridor, with showers and storms more isolated by about 2-3 am. Zones/grids have been updated for the latest PoP trends. && .SHORT TERM...(This evening through Friday) ISSUED AT 234 PM CDT Thu Aug 10 2017 Developing surface low over northern WI this afternoon has a front stretched south and southwest through the Quad Cities and into the Plains. A prefrontal trough has moved across the region today, producing showers and thunderstorms north and south of Central IL, but have so far remained clear of ILX warning area. Cumulus field is pretty expansive across the region on satellite imagery, but has done little to prevent the temperatures from climbing into the low to mid 80s. Short term concern is the line of precipitation and thunder that is currently firing to the NW, closer to the actual front. HRRR and NAM settles the front across the area this evening/tonight. The NAM barely brings much in the way of precip through...whereas the HRRR is far more aggressive in settling the thunderstorms into the area. RAP is falling somewhere in between. Front slows considerably in the overnight hours and the precip slows and stretches out east to west, in mainly parallel flow, before weakening. Front is only expected to make it into the southeast by tomorrow mid morning...and have to maintain pops in the east central and southeastern portions of ILX through midday. With the cold front, slightly cooler air moves into place, but tomorrows highs will only vary by a couple degrees. The winds will become more west/northwesterly but remain under 10kts through the day. .LONG TERM...(Friday night through Thursday) ISSUED AT 234 PM CDT Thu Aug 10 2017 Cooler temperatures continue through the weekend as the highs top out in the upper 70s/near 80. Friday night through most of Sunday, the weather looks mild and dry, but a quick shortwave ripples through at 500mb aloft. This wave will push another, quicker system through the Midwest, bringing the next chance for precip/thunderstorms. A brief respite from the rain for Tues/Tues night, but here is where the models start to diverge pretty distinctly. Both GFS and ECMWF start to hint at an active pattern with a series of waves moving through an almost zonal set up aloft. Details in the extended will surely shift through the next few forecasts...but the set up is for a potentially active pattern. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 540 PM CDT Thu Aug 10 2017 Widely scattered thunderstorms will affect some of our TAF sites this evening which may bring about brief MVFR cigs with heavy rain and gusty winds. Away from any thunderstorm this evening, we are expecting mainly VFR conditions this forecast period. One time frame of concern is between 13z and 17z Friday when a cool front will be pushing across the area. A few models have suggested some MVFR cigs will be possible along and just after FROPA. At this point, will lower cigs a bit but keep them above MVFR category Friday morning. Southwest winds of 5 to 10 kts tonight, but much higher in and near any strong TSRA, will become west to northwest Friday morning and mainly northwest at 8 to 13 kts across most of the area during the afternoon. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Geelhart SHORT TERM...HJS LONG TERM...HJS AVIATION...Smith
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1033 PM CDT Thu Aug 10 2017 .UPDATE... Updated for evening discussion. && .DISCUSSION... Overall a quiet night is in store for the area as all of the convection has winded down & decreased across the region. Most of the area tonight will remain quiet as most of the strongest moisture transport will be off to our east & only some limited lift/divergence aloft will keep most of the area quiet overnight. Some showers overnight can`t be ruled out before a shortwave & cold front help spark more scattered showers & storms by tomorrow. Decreased PoPs areawide overnight before some light showers begin to move in from the east & gradually spreading back west through the morning & day as the shortwave & front move towards the area. Main forecast issue overnight will be some patchy dense fog. There will be a combination of low clouds (stratus) & patchy dense fog but a lot of the hi-res guidance, including the HRRR, ARW, NMM & some global models show a very low condensation pressure deficits areawide. This is due to such low dewpoint depressions & our crossover temperatures are around 2-4+ degrees. Winds will be fairly light overnight, mainly less than 3kts. This will help potential for some patchy dense fog overnight. Time lagged HRRR is also hinting at this idea as well. This looks to mainly be between late tonight after midnight through mid- morning around 9AM Friday. Introduced a limited in the HWO/graphics for patchy dense fog areawide. Will hold off on a dense fog advisory as the combination in low stratus & patchy dense fog or any stronger winds overnight may make it hard to get too dense or too large of an area. However, these trends will be monitored. /DC/ Prior discussion below: Only updates to the forecast were to let the flash flood watch expire at 7PM due to the lessening rainfall rates & widespread nature of convection gradually lessening. Adjusted PoPs to current lessening trends but overall not much changes needed. Most rainfall chances look later tomorrow as better moisture convergence & upper divergence look to move in after daybreak, with better chances of storms later as a shortwave & front gradually drop down through the Plains and provide better focus for storms later in the mid-late afternoon tomorrow. Took out the limited flooding for tonight due to convection being more focused into tomorrow. Adjusted the HWO & graphics to update the wording. Another forecast update will likely be done in the next couple hours. /DC/ Prior discussion below: Tonight and Friday: Wind field around MCV over the ArkLaMiss Delta providing good convergence/forcing for the numerous showers and thunderstorms over the area this afternoon. Satellite, model, and observed UA data continue to show deep tropical moisture (PWs aoa 2 inches) in place over the region and should continue to be the case. As such, very little lift needed for cloud cover and convective initiation. In the mid levels, ridge continues to build over TX into southern LA with the westerlies still in control of the majority of the forecast area. Series of weak shortwaves will continue to impact the forecast area mainly this evening and Friday afternoon. With these conditions, numerous showers and thunderstorms will continue to be possible with locally heavy rainfall. The lack of a low level focus, however, should limit the widespread heavy rainfall/flooding potential. Thus, will let the flood watch expire at 11/00Z, but keep at least limited flood potential wording in the HWO. /26/ Friday Night through Wednesday Night: That muggy soupy airmass is what we will continue to battle with moving into the weekend and the start of the the following work week. The weak cold front that dropped down from the Central Plains on Friday will stall for the next few days around the Ozarks/Northern MS region & continue our rain chances throughout this time period. Despite WPC`s QPF maximum centered to the west of our region (in Oklahoma) for the next five days, localized flooding will continue to be a concern for the ARKLAMS area. With the ground already super saturated in some areas, any moderate rainfall will again create localized flooding concerns. However, trying to pinpoint which location will be affected by flooding can`t easily be detected. Given that ridge located over Texas alters from growing stronger on Saturday morning and weakening come Sunday, fluctuations on where showers/storms generate will be based on these subtle changes. As of now, we will keep a limited threat for flooding from Saturday into Tuesday for the the entire ArkLaMs area. For Monday, that boundary will slowly propogate east, but POPs will still be in the 40-50% range as diurnal showers and t-storms will continue. A front moving in from the Central Plains on Monday night/Tuesday morning will skirt to our north and may ignite some storms in our northern areas, however the latest GFS run shows the front fizzling out by the time is reaches this far south. We may catch a break from the rain come midweek as another ridge starts to build and center over Louisana--keeping rain chances to our east. However, the price of the rain dying down will be hot conditions returning. /12/ && .AVIATION... 00Z TAF discussion: Scattered showers are gradually falling apart over most of the region, except some lingering down towards HBG, PIB, MEI & NMM. Overall main issues again will be lower ceilings (stratus) &/or visibilities (patchy fog) overnight. Main time will be after 11/05-07Z MVFR ceilings/visibilities to move in before more IFR to possibly LIFR ceilings &/or visibilities will move in areawide by around 11/09-11Z. If any areas of patchy to patchy dense visibilities (IFR or lower) develop, look for these to possibly be near GLH, GWO, GTR, MEI & NMM. Expect these visibilities & stratus to gradually lift around 11/14-15Z. More showers (VCSH) are possible areawide at all TAF sites again tomorrow after 11/14-15Z and more storms (VCTS) after 11/16-18Z. /DC/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 73 88 74 89 / 14 58 31 64 Meridian 73 88 74 89 / 20 61 26 59 Vicksburg 73 89 74 89 / 14 57 34 57 Hattiesburg 73 87 75 90 / 14 63 20 66 Natchez 73 88 75 88 / 14 59 25 65 Greenville 72 88 74 88 / 14 54 47 50 Greenwood 73 88 74 88 / 14 54 42 55 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$ DC
Area Forecast Discussion
National Weather Service Jacksonville FL
928 PM EDT Thu Aug 10 2017 ...MUGGY TONIGHT WITH PASSING COASTAL SHOWERS... .UPDATE... Much less convective coverage across the area today compared to recent days with the intrusion of some drier mid level air from the NE on the subsident side of the broad low offshore of the Florida Atlantic coast. Scattered sea breeze and outflow storms were west of Interstate 75 this evening, with continued dissipation expected through midnight. Closer toward the Atlantic coast, convergent bands with light to moderate showers were gradually increasing in coverage across our Florida Atlantic waters as the broad low center drifts slowly NNW. Expect a gradual increase in convection over the coastal waters through the night, with the potential for some showers to move onshore impacting coastal counties and the St. Johns River basin through sunrise. Winds will remain elevated 5-10 mph along the coast tonight, while inland winds will decouple under mostly clear to partly cloudy skies. With recent rainfall and dry mid level air, potential for fog inland exists. Updated the forecast for patchy fog for inland areas west of Highway 301 before sunrise Friday morning, while a chance of showers will exist along the coast. Min temps will range in the 70s tonight with a continuation of muggy conditions. && .AVIATION... Waves of showers will move inland through the night with the greatest potential of MVFR ceilings impacting SGJ tonight and advertised prevailing BKN020 with VCSH. Shower potential and low ceiling potential will increase south to north toward CRG and SSI through sunrise, and then inland through the day Friday where VCSH was advertised for inland terminals. Tonight potential for low stratus and fog impacting the terminals was low via HRRR and SREF visibility and low stratus model guidance, but there was a low (5% chance of occurrence) of IFR cigs at GNV. Given low confidence, refrained from inclusion in the 00Z TAF package. && .MARINE... A weak area of low pressure offshore of the central Florida Atlantic coast will drift northwest tonight. Surface observations indicated a slight tighter pressure gradient over the local waters on the northern side of this low, and thus updated the forecast leaning toward the NAM12 winds which resulted in forecast winds of 10-15 kts this evening, relaxing to 5-10 kts and backing NNE after midnight as the low drifts northward toward the local waters. Combined seas were running 3-4 ft with Canaveral East near 6 ft last observation. Waves of showers, possibly some isolated tstorms, will rotate across the waters through tomorrow around the broad surface low. Rip Currents: A persistent east-southeasterly ocean swell will continue a moderate risk along NE Florida coast through Fri. && .PRELIMINARY POINT TEMPS/POPS... AMG 74 91 75 92 / 20 50 30 60 SSI 77 87 78 89 / 20 30 20 60 JAX 74 90 76 92 / 10 40 20 60 SGJ 76 88 76 90 / 20 40 30 50 GNV 73 91 74 92 / 10 60 40 50 OCF 74 91 75 91 / 10 60 40 50 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$ Enyedi/Zibura/McGinnis
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
656 PM CDT Thu Aug 10 2017 .SHORT TERM... (Through Late Friday Afternoon) Issued at 252 PM CDT Thu Aug 10 2017 A cold front will push into northern Missouri early this evening with scattered showers and thunderstorms will be possible along the boundary over the western half of the region. The last several runs of the HRRR generate scattered showers and storms but placement varies run to run. The GFS/NAM/ECMWF are in consensus with moving the cold front to the St Louis metro area or just to the south of the city. Winds will switch from the south southwest to the northwest but will remain light. The frontal boundary will push into southeast Missouri and southwestern Illinois late Friday morning. A series of upper level impulses will ride along the front providing enough ascent for scattered showers and thunderstorms through Friday afternoon. Temperatures will be at or just below climatological normals. Kelly .LONG TERM... (Friday Night through Next Thursday) Issued at 252 PM CDT Thu Aug 10 2017 A surface cold front will extend from the Ohio Valley across extreme southern IL through southeast MO early Friday evening. This front will continue to push southward on Friday night as the eastern U.S. upper trof sharpens up and surface high pressure builds into the upper and middle MS Valley. There will be a threat of some residual isolated to widely scattered showers and thunderstorms in the vicinity of the frontal zone during the evening, but the main elements of interest with be cooler and drier air overspreading the region in the wake of the cold front. The large scale pattern continues to show a broad but deamplifying mean trof from the Rockies eastward into the eastern U.S. through the weekend, and this will maintain surface high pressure as the controlling feature Saturday through Saturday night. Greater model variability and poor run-to-run model consistency exists Sunday through next week leading to less confidence in the forecast details. The ECMWF has backed off the previous "wet" forecast for Sunday, but both the GFS and NAM show a progressive short wave trof moving across the region within the broad upper trof. Lift with this wave and low level WAA/MCON attendant with a weak southwesterly LLJ on the backside of the retreating surface high are forecast to support showers and thundestorms, primarily for central and northeast MO. Differences on Monday with the strength and speed of a digging shortwave trof once again result in uncertainty in the forecast. The GFS is slower/stronger with QPF nearly everywhere within the 12h period, while the ECWMF is faster and weaker and predominately dry. Predicability continues to diminish as we head into midweek and the pattern flattens. We see progression of a low-amplitude upper level ridge/trof system, the models diverge on details and timing of any precipitation chances. Below average temps still look on target through at least the first few days of next week. Glass && .AVIATION... (For the 00z TAFs through 00z Friday Evening) Issued at 656 PM CDT Thu Aug 10 2017 VFR conditions, outside of any SHRA or TSRA, are mainly expected at the TAF sites thru the valid period. The best pcpn chances that are worth mentioning will be initially this evening at UIN, with more spotty pcpn dropping south later tonight into Friday morning near a cold front at COU and STL metro sites. TES && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Melbourne FL
834 PM EDT Thu Aug 10 2017 .UPDATE... Tonight...A weak and elongated surface low offshore Brevard is forecast to continue lifting slowly northward. Highest moisture has been over the Treasure Coast and the models show it being pulled northward along the coast. Wind fields will be light over land so there will be weak low level convergence, but with the high moisture, we will need a small chance for showers through the night along the coast. Won`t carry thunder as afternoon convection had little lightning and with loss of heating, any storms overnight will be confined to the Atlantic. The HRRR and local WRF support this general scenario. Only cosmetic changes planned to the previous forecast. && .AVIATION...Weak surface low crawling northward just offshore will produce a moist low level cyclonic flow. This may lead to areas of low clouds forming overnight. For now, will only carry some MVFR ceilings across the interior terminals. The models are not showing a lot of precip over land tonight, but high moisture associated with the weak low could produce a few showers at the coastal terminals. Moisture is forecast to be high areawide on Fri, so daytime heating is expected to bring scattered to numerous showers and scattered lightning storms. && .MARINE... Tonight-Friday...Weak surface low lifting northward through the waters should keep the main tightened pressure gradient just to our east. Southerly winds over the south and central offshore waters may reach 15 knots tonight and across the north offshore waters Fri. Otherwise, winds look 10 knots or less. Some fresh swell generated by the tightened gradient to our east may keep seas 4-5 feet well offshore tonight and around 4 feet Friday. Seas will be 2-3 feet nearshore. Guidance is indicated scattered to numerous showers and a few lightning storms through Friday. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ Forecasts...Lascody Radar.......Sedlock Aviation....Smith
Area Forecast Discussion...UPDATED
National Weather Service Norman OK
637 PM CDT Thu Aug 10 2017 .AVIATION... 11/00Z TAFs. Primarily VFR conditions expected outside of TSRA. For the first 3 to 6 hours of the forecast, main impacts from TSRA will be brief from KPNC to KOKC/KOUN to KSPS. More in the way of widespread and longer lasting shower and storm activity still appears possible overnight so will keep TEMPO and prevailing MVFR conditions going into tomorrow morning. Outside of convective strong wind gusts, prevailing winds will be light through the period. && .PREV DISCUSSION... /issued 229 PM CDT Thu Aug 10 2017/ DISCUSSION... Will keep this short as strong storms are already ongoing. In the broad sense, it is likely that we will experience a couple of rounds of thunderstorms today and overnight. But the specifics are still a little in question. The current storms in northwest Oklahoma have lost a little punch as they moved in from the Oklahoma panhandle. But they are moving into an area of much higher surface based CAPE, so we expect some regeneration. Meanwhile, additional storms are in the process of developing in western Kansas, which may evolve into the main show tonight. And now the last few runs of the HRRR have also been signaling the possibility of storms in the southwest this evening as well. Will not get too tricky on timing but have kept broad high POPs across much of the area, and expanded them farther south with the HRRR trends. Meanwhile, it appears we will remain in a relatively active pattern with west-northwest flow aloft and waves moving into the upper Midwest and the northern and central Plains. Highest rain chances will be northeast, while still generally drier and warmer southwest. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 72 85 71 85 / 80 60 60 60 Hobart OK 72 89 73 89 / 50 30 40 50 Wichita Falls TX 75 97 76 95 / 30 20 20 40 Gage OK 67 81 68 83 / 70 30 60 60 Ponca City OK 69 84 69 83 / 80 60 40 50 Durant OK 74 95 74 90 / 20 40 40 40 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && $$ 25/09/11
Area Forecast Discussion
National Weather Service Paducah KY
841 PM CDT Thu Aug 10 2017 .UPDATE... Issued at 841 PM CDT Thu Aug 10 2017 The latest HRRR data keeps any convective activity to our west/northwest until through 09Z, and then indicates scattered showers and storms spreading into southern Illinois and southeast Missouri through sunrise. Adjusted the forecast to delay the arrival of convection overnight into Friday morning. Temperatures are a bit tricky this evening, as clear skies and calm winds have allowed some locations, especially in the east, to drop faster than forecast. Would trend downward with temperatures overnight, but clouds are expected to increase over most of the region before sunrise. Decided to keep lows at the same general levels, but have them occurring shortly after 06Z and then steady or slightly warming through sunrise as the clouds increase. && .SHORT TERM...(Tonight through Saturday night) Issued at 241 PM CDT Thu Aug 10 2017 Showers from Perryville to northwest of Van Buren hitting a wedge of drier air, and weak surface ridge. So little eastward progress expected into the evening (we think anyway). In fact, the hi res data dissipates activity through the evening. Then after midnight, some redevelopment appears possible from southern IL into southeast MO. Friday, a mid level wave is forecast to move across the area from WNW to ESE, Bumped up PoPs to likely by afternoon, though coverage is still somewhat of a question. If you buy the NAM, we may see some strong storms (isolated svr?) in west KY, though low level flow is weak in the model. Mid level flow isn`t bad. The other models aren`t as impressive on convective parameters. Never know what to think of the GFS. The NAM has not been too bad lately for near term trends, so we`ll monitor. Chances will decrease from west to east Friday evening. Saturday into Saturday night will be mainly dry. Maybe a slight chance of convection over SEMO. Persistence and latest MOS used for temps. Favored the NAM overall for PoPs/Wx. .LONG TERM...(Sunday through Thursday) Issued at 241 PM CDT Thu Aug 10 2017 Medium confidence in the extended period, with model disagreement continuing with regard to timing and placement of shortwave energy across the area. Sunday starts off with weak surface high pressure that gradually loses its grip on the region. 12z model guidance has generally came in slower with timing of precipitation, with consensus supporting Sunday evening into at least the first half of Monday now. 12z GFS continues to be an outlier, keeping rain with the Sunday wave south of the area, and has secondary stronger energy moving through Monday into Monday night. Thus kept in small chance PoPs through Monday evening/night. The highest QPF amounts are expected across the southern half of the region, and northern counties may not end up with much. Surface high pressure builds in from the north on Tuesday, providing a dry weather day. The 12z ECMWF and Canadian came in faster with southerly flow/moisture returning and bring back in precipitation chances for the western half of the area by Wednesday. GFS and its ensemble mean continue to support a slower wave and keep it dry until Wednesday night or Thursday. The blended approach stuck with the slower solution with PoPs not returning until Wednesday night and peaking again next Thursday. Temperatures will continue to average below normal through the period with highs generally in the low to mid 80s and lows dipping into the mid 60s. Humidity levels also aren`t expected to get too carried away with dewpoints in the mid to upper 60s much of the time. && .AVIATION... Issued at 1209 PM CDT Thu Aug 10 2017 VFR conditions with light winds through midday Friday. Small chance of showers and storms after 06z. Not enough confidence in the chances and coverage to include in the TAF`s. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ UPDATE...DRS
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