Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/18/17

Area Forecast Discussion
National Weather Service Lake Charles LA
825 PM CST Fri Feb 17 2017 .DISCUSSION... Inflow into approaching surface trof across the NW Gulf off the SE TX/SW LA coast around 20-25 kts (per platform reports) outside the thunderstorm area, special marine warning within this line of thunderstorms. Expecting winds to diminish within the next couple of hours to 20 knots or below. Not anticipating the need for a 2 hour SCA, but updated forecast to expand Small Craft Exercise Caution to include 0-20 nm zones. Also, redistributed pops across the coastal waters for this based on latest HRRR reflectivity guidance, which still indicates most of this activity diminishing by 06z or midnight. DML && .PREV DISCUSSION... /issued 655 PM CST Fri Feb 17 2017/ DISCUSSION... Wx map shows surface trof and upper level disturbance axis over East Texas this evening, continuing to move east, with showers and thunderstorms along and southeast of the axis. Main area of showers and thunderstorms over lower Acadiana into the eastern coastal waters, with a secondary cluster of thunderstorms off the Southeast Texas coast right along the trof axis. Thus, updated forecast this evening over SE TX/SW LA into the adjacent coastal waters for higher pops the next few hours, trimming down from NW to SE towards midnight into the overnight hours. DML PREV DISCUSSION... /issued 529 PM CST Fri Feb 17 2017/ AVIATION...Rain will continue to move east across the region for the next few hours. Lower vis in rain can be expected, however for the most part the visibility will remain above 3 miles. Lower ceilings are expected through tonight. PREV DISCUSSION... /issued 443 PM CST Fri Feb 17 2017/ DISCUSSION... Upper low over the Red River Valley with a trailing trof quite evident in water vapor satellite imagery to our west. The trailing trof axis is TX starting to take on a bit of a negative tilt as it pivots TWD E TX this afternoon. The upper low is progged to continue slowly off TWD the ENE tonight, with the with the trof axis crossing the area this evening. Rain with embedded heavier convective cells, including isolated thunderstorms, will continue along/ahead of this axis, ending from west to east during the evening hours. Low level moisture will linger behind, however, and there is some potential for patchy fog formation overnight into SAT morning, but at this time have leaned more toward a very low cloud deck while maintaining a slight chance of rain. Deepening westerly flow south of the upper low on SAT will gradually erode the low level MSTR save for a SFC layer maintained by southerly onshore winds. Cloud cover will become more scattered by the afternoon hours, with temperatures climbing into the upper 70s/near 80. Heights will build SAT night into SUN as this upper low weakens and accelerates off to the E while a robust upstream upper trof reaches the Four Corners. Increasing and deepening moist southerly flow will gradually overspread the area on SUN as the upper trof slowly moves east of the four corners, with PWATs climbing to near 2 inches over E TX by early MON morning, which is plus 2 to 3 standard deviations above the norm. Fueled by this copious MSTR, despite progged limited instability, the otherwise broad synoptic lift augmented at times by a noisy and difluent flow aloft, is expected to yield a widespread N-S oriented swath of rain and embedded heavier convective cells/TSTMS developing over E TX late SUN night. There remains some spread in the global model guidance to contend with in terms of the timing of the heaviest rain, with the quickest solution having the onset in my E TX zones after midnight SUN and the slowest not getting it east of the Atchafalaya until TUE morning. The overall consensus at this time is for primarily a Monday event, with the swath of HVY rain entering E TX MON morning and exiting to the east MON evening. Areawide totals of 1 to 3 inches with locally higher amounts are possible. Rain chances linger but decrease TUE into WED as the base of the TROF closes off and tracks SEWD across the GULF. Dry and warm THU into FRI as a narrow ridge builds in behind the departing upper low and ahead of another incoming trof. 13 MARINE... Showers and thunderstorms will continue to affect the Gulf waters the rest of this afternoon through this evening as an upper trof over Texas and Oklahoma pivots through the region. This activity will come to an end after midnight once the trof axis passes, with the modest southeast winds over the central and eastern Gulf waters also subsiding. Dry weather and light south winds are expected on Saturday. Sea fog may become an issued over the nearshore waters/coastal lakes and bays by Saturday night as very moist air is transported atop the cooler shelf waters. Winds are expected to increase Sunday with the approach of another upper level trof, which is forecast to result in widespread showers and thunderstorms Monday into Monday night. Rains are expected to linger but decrease in coverage Tuesday and Wednesday, while winds become northerly as an area of surface low pressure develops over the central Gulf. 13 && .PRELIMINARY POINT TEMPS/POPS... AEX 54 76 58 81 / 20 10 10 10 LCH 58 76 63 79 / 30 10 10 10 LFT 58 78 62 81 / 40 10 10 10 BPT 60 79 65 79 / 40 10 10 20 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...None. TX...None. GM...SMALL CRAFT EXERCISE CAUTION until midnight CST tonight for GMZ450-452-455-470-472-475. && $$ PUBLIC...04
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
905 PM CST Fri Feb 17 2017 .UPDATE... Issued at 905 PM CST Fri Feb 17 2017 Forecast appears to be on track with only minor adjustments made into Saturday. Upper level LOW is located over eastern OK this evening with an area of rain on its downstream flank with the northern extent near the intersection of MO-KS-OK. The LOW center is expected to track E-NE thru far southeastern MO around midday Saturday and into the OH Valley Saturday night. Scattered WAA showers associated with this LOW are still expected to move into southeast MO late tonight and continue past daybreak with a transition at some point toward late morning to an attempt at getting a deformation zone of stratiform pcpn going in nearly this same area. It is at this point where a few tweaks to the forecast were made--expanding the northern coverage a bit into STL metro and most of the I-70 corridor for some sprinkles possible late Saturday morning and into the afternoon. Otherwise, temps left alone for most areas from previous forecast. TES && .SHORT TERM... (Through Late Saturday Afternoon) Issued at 234 PM CST Fri Feb 17 2017 The main item of interest over the next 24-30 hours will be the threat of any rainfall associated with the lifting upper low currently located over the southern Plains. Model consenus shows the upper low lifting east-northeast tonight to the vicinity of the NW AR/SW MO border by 12Z Saturday, and then into the TN Valley by early Saturday evening. The increase in clouds with this system will contribute to mild temperatures tonight with most locations only experiencing lows in the 40s, and some record high mins will be possible. The unseasonably warm temperatures (+20 to +25 degrees above average) will continue on Saturday as well, however the greater cloud cover should temper the max temp readings back a bit from those experienced the last few days. Rainfall is a little more iffy. Weak large scale ascent associated with the upper low spreads into southeast MO and southern IL overnight and persists to varying degrees on Saturday morning. The low levels however are quite dry and moisture will be largely confined to the mid-upper levels. I prefer the RAP depiction of this and thus some scattered rain showers seem the most probable scenario across parts of southeast MO and southern IL, with the probability diminishing and shunting east in the afternoon with the progression of the upper system. Glass .LONG TERM... (Saturday Night through Next Friday) Issued at 234 PM CST Fri Feb 17 2017 Upper ridge to build into region Saturday night, so will see dry and above normal temperatures through the rest of weekend and into early next week. Near record highs Sunday and Monday in the upper 60s to mid 70s. By Monday, upper ridge begins to move off to the east as next weather system approaches. So will see low level moisture on the increase as well as decent instability for our area. But still have the issue with split flow aloft, models continue to lift the northern stream wave out faster through the Great Lakes region, while southern stream closed low tracks eastward slowly. However, 12z model runs are a bit more optimistic with two streams phasing together, giving us better chances for rain early Monday morning through Tuesday morning. Could see scattered/isolated thunderstorms Monday afternoon/evening, mainly over central/northeast MO, as well as west central IL, so added thunder mention there. Weak boundary washes out over region for mid week with zonal flow aloft, so will see slightly cooler highs in the mid 60s to low 70s. Next system to approach area on Thursday with strong cold front moving through Friday. This is when we will have our best chances of showers and a few thunderstorms. Highs will dip down into the low 50s to mid 60s by Friday, but still above normal for this time of year. Byrd && .AVIATION... (For the 00z TAFs through 00z Saturday Evening) Issued at 545 PM CST Fri Feb 17 2017 VFR conditions and southwesterly surface winds will prevail at the TAF sites thru the valid period. An upper level storm system will pass to our south late tonight and Saturday morning, and should result in some rain shower development, but this currently is expected to remain to the south of the TAF sites, but if any one area and time has a greater chance than the others, it is the STL metro sites around 12z. Will monitor observations and the latest model data for any adjustments and inclusion of rain mention in the TAFs this evening. TES && .CLIMATE... Record Highs 2/17 2/18 2/19 2/20 STL: 77/1911 74/1971 77/2016 78/2016 COU: 74/2011 71/1930 76/1930 76/2016 UIN: 72/2017 68/1971 71/1930 72/2016 && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
704 PM EST Fri Feb 17 2017 .UPDATE... 00Z water vapor and H4 RAP analysis shows a complex upper level pattern over the CONUS this evening. Very strong Pacific jet is arriving over the California coast...with highly diffluent flow. This diffluence is aiding lift and resulting in significant flooding rainfall across portions of the western states. The southern half of this flow leads into a negatively tilted trough/upper low pivoting through the southern plains/lower MS Valley this evening. WV imagery/radar and lightning detection show some fairly vigorous convection ongoing ahead of this energy over the north-central Gulf of Mexico. The height falls advancing along the NW Gulf coast today have helped to build the downstream ridge over our region...and this ridging will hold overnight and help keep our forecast dry and benign into early Saturday morning. At the surface...high pressure centered just east of the FL peninsula will be slow to give up influence on the region overnight/Saturday morning. Eventually the approach of the upper trough and an associated surface reflection/trough will push this ridge further south/east...but not really until later Saturday afternoon. So...the forecast for the overnight hours will remain dry and seasonable in terms of temperatures. Initial height falls and associated synoptic lift support aloft associated with the approach of the upper trough will barely have enough available column moisture to produce clouds...nevermind precipitation. Very slowly through the day on Saturday...the column will moisten with high clouds becoming middle clouds and so on... The ensemble guidance as of right now suggest the best synoptic lift by the time enough moisture is available will be confined to the northern half of the FL peninsula...and it will be this area that sees the best potential for anything more than sct light showers. Even our far northern zones (while expecting rain)...should not expect significant amounts of rain. The totals should decrease quickly down toward the I-4 corridor...and even more further south. Looks as through the first showers may begin up toward the Nature Coast perhaps toward midday...and then during the afternoon/early evening as one heads further south and east. Overall...this event does not look to be significant in terms of rainfall for our area...but rather nuisance type showers for a weekend day. Luckily...the second half of the weekend looks to be the upper trough axis moves east of the region by Sunday morning...with synoptic suppression/drying arriving arriving overhead from the west and northwest. The forecast for Sunday into the early portion of the upcoming work week looks dry and increasingly warm before the next potential for rainfall arrives during midweek. Have a great Friday evening and a fun/safe weekend everyone! && .AVIATION... Significant restrictions are not anticipated through the TAF period at west-central and southwest Florida terminals. Prevailing VFR and light winds can be expected through at least 08/09Z for all terminals...thereafter...a brief period of MVFR Vis is possible at KPGD. General VFR conditions are expected for the daylight hours of Saturday...although ceilings will be lowering (but generally staying above 3KFT). The potential for sct mainly light showers will increase for KTPA/KPIE/KLAL/KSRQ after 18-20Z...with only isolated showers expected further south. && .Prev Discussion... /issued 255 PM EST Fri Feb 17 2017/ SHORT TERM (Tonight - Saturday)... Upper level ridging extends from southern Florida northwest over the southeast states, through the Mississippi River Valley. This ridge slides east through the night as an upper low and troughing located over Texas moves toward the region. Surface high pressure located over the Florida peninsula slides east by Saturday morning and will be located north of the Bahamas. A surface low moving east along the northern gulf coast will produce rainshowers along the Nature Coast mid morning on Saturday and will progress east-southeast through the day with rainfall starting late afternoon/early evening for Tampa Bay northward. The highest POP`s will take place north of the I-4 corridor and over the northern coastal waters. Overnight temps tonight are expected to be 8-10 degrees warmer than what we saw last night. The daytime highs on Saturday will be very similiar to what we saw today, with highs in the mid 70`s to low 80`s. MID/LONG TERM (Saturday night through Friday): The ridge continues to break down as a fast moving shortwave over the Tennessee Valley quickly pushes off to the east and moves off the Carolina coast. The associated upper level energy pivoting around this low will be the driver for showers and a few thunderstorms Saturday night with the best chance for rain north of the I-4 corridor. A second midlevel vorticity max will slide through north Florida early Sunday morning which will provide enough lift for a few lingering showers. A strong upper level ridge builds in the wake of the trough with dry and hot temperatures through Tuesday. The progressive pattern continues in the second half of the period with a stacked cutoff low strengthening in the Gulf of Mexico. The GEFS and GFS deterministic solution have come into better agreement with the 12Z European run in the placement and evolution of the system on Wednesday. The current thinking is a more southerly track from 24 hours ago which would place the heaviest rain threat in Southwest Florida on Wednesday. Nevertheless, this system will likely produce heavy rains and thunderstorms. The exact placement of the low will be critical for our impacts in West Central Florida. MARINE... High pressure has set up over the eastern Gulf of Mexico allowing for perfect boating conditions this evening. Winds are expected to be 10 knots or less, becoming light and variable overnight. An area of low pressure approaches the coastal waters on Saturday and will produce increasing chances of rain and thunderstorms through the day on Saturday. Winds will also be on the rise as they shift to the southeast through southwest around 10-15 knots ahead of the low pressure system. Conditions improve once again late Saturday into Sunday as high pressure builds back into the area. The only other concern will be with red tide along Sarasota County beaches. A Beach Hazard Statement will be extended until Sunday evening. FIRE WEATHER... After seeing relative humidity values in the 20-30 percent range today, RH values will be on the increase overnight and into the weekend, which will preclude any need for a Red Flag Warning. Similiar to what we have seen the past few nights, fog will be possible in fog prone areas, especially near the wild fires in Polk County. An area of low pressure moves across the peninsula on Saturday producing increasing rain chances with the highest chances along the Nature Coast north of the I-4 corridor. With the increasing chance of rainshowers on Saturday, it should help to suppress any remaining smoldering wild fires in Polk County. No other fire weather concerns expected through the period. && .Preliminary Point Temps/PoPs... TPA 56 74 64 79 / 0 30 50 10 FMY 56 81 66 84 / 0 10 20 20 GIF 54 80 63 82 / 0 20 50 10 SRQ 54 74 63 78 / 0 20 40 10 BKV 45 76 58 80 / 0 30 60 10 SPG 59 75 65 78 / 0 30 40 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...Beach Hazards Statement through Sunday evening for Coastal Sarasota. Gulf waters...None. && $$ UPDATE/AVIATION...Mroczka PREVIOUS DISCUSSION...WYNN/NORMAN
Area Forecast Discussion
National Weather Service Topeka KS
511 PM CST Fri Feb 17 2017 ...AVIATION UPDATE... .SHORT TERM...(This evening through Saturday) Issued at 322 PM CST Fri Feb 17 2017 Upper low was observed via water vapor imagery rotating through Oklahoma, lifting mid level moisture into southeast Kansas. Surface trough axis shifting east towards the Great Lakes region will shift gusty southerly winds towards the north after sunset. Ahead of this weak boundary, temperatures have warmed into the lower 70s while dewpoints mixed down into the lower 30s. Topeka broke the record high at this hour with a high temperature of 77 degrees. This has resulted in RH values near the 20 percent range for most of the CWA. Much of the remained underneath the Extreme fire danger category given the slightly weaker winds than yesterday, with the exception of the Emporia area that recorded a peak gust of 34 mph. For tonight, winds calm, becoming light and variable as a ridge axis drifts southward into northern KS. Potent, incoming upper trough across California will shift the upper low northeast and therefore increase cloud cover towards southeast Kansas Saturday morning. These clouds should dissipate as the low exits into Missouri during the afternoon, bringing mostly sunny skies and light winds across the CWA. Highs may be slightly cooler, given the weaker winds, however still well above normal in the upper 60s. Increasing moisture from the departing system lowers the fire danger threat during the afternoon. .LONG TERM...(Saturday night through Friday) Issued at 322 PM CST Fri Feb 17 2017 The mid and long term period continues to look much warmer than normal with focus on two storm systems Sunday night into Monday and again Thursday into Friday. While there will be some fluctuations in airmass temperature with the influx of the trough-ridge-trough-ridge-trough pattern, the overall high and low temperatures will remain quite warm at least through the middle of next week. Normal highs are in the mid to upper 40s this week with lows in the middle 20s but actual high temperatures will be in the 60s to 70s and lows mainly in the 40s or even low 50s. The first storm system on Sunday night will see a pretty good influx of moisture throughout the column but the two main elements of forcing will split with one short wave trough lifting quickly north into the main jet stream while the other more significant chunk of energy will close off into the Gulf of Mexico. The local forecast area will largely fall in between the two areas of best forcing but with ample moisture and even some instability, expect to see at least scattered showers and thunderstorms. Instability is unlikely to be impressive given rather weak mid level lapse rates but there are some indications that a few hundred J/kg of MUCAPE will be expected so have included thunder potential throughout the period. The second storm system appears likely to be more impressive with a strong jet streak forecast to move into the Plains with a deepening upper low over the Central Plains. The current storm track is a bit farther north than previous model runs with the heart of the low tracking over Nebraska and a bit less precipitation locally. I think the main takeaway point at this time is that there is a good chance for a strong storm system to develop at the end of next week, with both winter weather and thunderstorms possible with this storm, but substantial uncertainty in the storm track. Much cooler air is likely to filter in behind this storm...with temperatures becoming near or below normal. && .AVIATION...(For the 00Z TAFS through 00Z Sunday) Issued at 511 PM CST Fri Feb 17 2017 Have a VFR forecast persisting with models showing no real forcing from the upper low impacting the terminals. However there is some concern with low level moisture advection progged through the morning across east central KS. RAP and NAM forecast soundings show the possibility for some stratus or fog to form by Saturday morning. It is not out of the question with some 40 degree dewpoints already moving into south central KS. There could be some radiational fog if skies remain clear. But confidence is low since low level winds will be weaker and the surface low remaining to the southwest. Also the mid and high clouds may spread north limiting the radiational cooling. Will need to monitor this potential through the evening and amend accordingly. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Prieto LONG TERM...Barjenbruch AVIATION...Wolters