Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/24/20

National Weather Service Hastings NE
601 PM CST Thu Jan 23 2020 .UPDATE... Issued at 600 PM CST Thu Jan 23 2020 Snow has ended across much of the area, and where light snow lingers, it is expected to end in the next hour or two. Have allowed the remainder of the Winter Weather Advisory to expire on time. && .SHORT TERM...(This evening through Friday) Issued at 334 PM CST Thu Jan 23 2020 Aloft: Moderately-amplified flow was over the CONUS per RAP tropopause analyses and aircraft wind data. A fairly deep/narrow troff extended from the Can Prairies to LA with a newly-developed low over Ern KS. A ridge was progressing thru the Wrn USA. The KS low will E into the OH Vly thru tomorrow. NNW flow over NEB/KS will become NW turn more anticyclonic. Surface: Wk 1014 mb low pres was near MCI and moving SE away from the rgn. 1033 mb high pres was over ONT. A piece of this high will break off and expand N-S acrs the Plns from ND-OK tonight and Fri. Rest of this afternoon: Skies will remain cldy over most of the CWA as a shield of snow conts over S-cntrl NEB. The Wrn and Srn fringes of the precip shield were falling as -RA. Some peeks of sun will be psbl along the Wrn border of the CWA. This precip shield will cont to drop S along with the newly-formed upr low. So precip will gradually decrease in intensity and/or end...espcly N of I-80. N-NNW winds will cont to gust 20-30 kt. The Winter Wx Advy will expire at 00Z and given that main roads are primarily wet. Tonight: Whatever -RA/-SN is over the CWA (primarily over the SE 1/3 of the CWA) will quickly come to an end early this eve. Low clds will remain over the majority of the CWA (along and E of Hwy 183). W of Hwy 183 skies will be more variable... and partly- mostly cldy. Diminishing winds. With the extensive cld cover...did not go as cold as NBM. Kept lows toward the higher end of the guidance spread. Fri: Finally a breather! This will be the 1st day of at least 4 without any wintry precip. Multi-model low-level RH progs and vertical cross sections suggest much of the day will remain cldy for most of the CWA. After 18Z we should see the back edge of the clds move E into the low-lvl winds back from NW to W and the thermal trof gets shoved E and weak WAA develops. Mdl consensus brings the clearing line up to Hwy 183 by 21Z and Hwy 281 by 00Z. So locations E of Hwy 281 will stay cldy all day. Extensive cloudiness will keep temps fairly cold tomorrow. From GRI N and E...temps will not get out of the 20s. .LONG TERM...(Friday night through Thursday) Issued at 334 PM CST Thu Jan 23 2020 Aloft: The wk shrtwv trof that will be moving thru the Wrn USA tomorrow will cont E and cross NEB/KS Sat-Sun. A shrtwv ridge will move thru Mon behind that trof. The global mdls cont to fcst the next Wrn USA shrtwv trof to head into the Srn Plns. There conts to be considerable uncertainty/mdl spread with its evolution. The EC runs cont to be the most aggressive...closing off a low. Meanwhile...the GFS runs have a decent trof but it remains open and more progressive. There is so much spread in the EC ensemble that the mean is not very supportive of the deterministic runs. So the fcst is highly uncertain next Tue-Wed. The 12Z EC run is the first one in the last svrl days that came in not closing off a 500 mb low and keeping the trof open. That has substantially cut its QPF. Surface: High pres will drift E of the rgn Sat...with a lee trof moving E into cntrl NEB/KS. That trof will dissipate Sun with a new lee trof forming in the lee of the Rckys. A wk cool front will be advancing thru the Wrn USA (associated with the shrtwv trof). This front will cross the CWA Mon night while wk low pres forms over the Srn Plns. This low will stay well S of the CWA Tue-Wed. Temps: Overall...temps will average near normal Sat-Thu. Sun should be the warmest day. Precip: With the EC now coming into agreement with the past svrl GFS runs...precip is looking pretty meager. In fact...most of these time periods will be dry. There could be some trace amts of precip Sat night with that trof moving thru. A touch of -RA/-SN is psbl Mon night into Tue. Multi-model QPF is less than 0.10". So it will be a light/minor event for area that see precip. Best chance will be S of I-80. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Friday) Issued at 515 PM CST Thu Jan 23 2020 Not an easy forecast tonight as ceilings vary across the area. Current thinking is that GRI will be more uniform in cloud coverage with ceilings around 1k and will lower this evening to IFR. EAR ceilings maybe VRB tonight as the clearing line is near Gothenburg. For the EAR TAF have kept ceilings a little higher and drop them to IFR after midnight. Thinking that EAR could SCT out around mid-day. Thinking VIS will be VFR, but will vary this evening as a little BLSN could impact the TAF sites. Winds expected to taper down this evening. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...Billings Wright SHORT TERM...Kelley LONG TERM...Kelley AVIATION...Beda
Area Forecast Discussion...UPDATED
National Weather Service Mobile AL
907 PM CST Thu Jan 23 2020 .DISCUSSION...See updated information for land areas below. && .UPDATE...Have adjusted pops for the rest of the evening to keep high pops mainly over the western Florida panhandle and south central Alabama where numerous showers will continue to shift eastward. Rain chances taper off overnight with dry conditions expected for the entire area by early Friday morning. Made adjustments to temperature trends and also added patchy fog, which may become dense in some locations. /29 && .PREV DISCUSSION... /issued 547 PM CST Thu Jan 23 2020/ DISCUSSION...Updated for latest aviation discussion below. AVIATION... 00Z issuance...Scattered to numerous patches of rain over much of the area move off to the east overnight into early Friday morning leaving dry conditions over the area. Expect to see patchy fog develop over portions of the area overnight which dissipate by early Friday morning. Southeast winds 5 to 15 knots diminish and become west to northwest around 5 knots overnight, then increase to near 10 knots on Friday. IFR to MVFR ceilings prevail overnight followed by clearing Friday morning. /29 PREV DISCUSSION... /issued 343 PM CST Thu Jan 23 2020/ NEAR TERM /Now Through Friday Night/...A broad upper level trough continues to advance eastward across the Plains states early this afternoon, with an increasingly moist southwest flow aloft spreading over our forecast area ahead of this feature. Regional radar imagery shows widespread light to moderate rain showers spreading across southeast MS and adjacent southwest AL in association with a short-wave impulse in the southwest flow aloft. We increased POPs to 90-100% this afternoon into this evening as the large scale ascent spreads over the region. A weak area of surface low pressure over southern LA this afternoon is forecast to advance eastward to near the MS/AL/northwest FL coast this evening. Weak low level warm advection ahead of this approaching feature may allow surface dewpoints to briefly rise to the upper 50s to near 60 degrees near the immediate coast late this afternoon into this evening. The latest short range model guidance continues to show very weak instability near coastal portions of the CWA, mostly less than 300 J/KG, though the higher resolution guidance, including the NAM-12 and RAP do attempt to bring slightly higher MLCAPE values of 300-600 J/KG near immediate coastal portions of northwest FL later this evening. However, guidance is showing a fairly weak low level jet on the order of 20-30 knots now. Given the weak jet dynamics and limited instability, the general risk of thunder through tonight remains appropriate. Patchy fog could develop this evening into late tonight. Rain chances should taper from west to east late tonight into early Friday morning as a cold front moves across the region. A much drier airmass will spread into the region Friday into Friday night on the base of the larger scale trough axis. Mostly clear skies are anticipated for Friday and Friday night. Lows tonight range from the lower to mid 40s over western portions of our area to the upper 40s to lower 50s across most places roughly along and east of the I-65 corridor. Highs Friday should range in the upper 50s to the lower 60s around the area. Cooler temperatures follow for Friday night with lows in the mid to upper 30s over the interior and in the lower 40s near the immediate coast. /21 SHORT TERM /Friday night Through Sunday night/...Surface high pressure builds into the region supporting a rain-free pattern through Saturday. Upstream, a short-wave mid-level trof dives southeast over the Red River Valley of TX/OK Saturday night causing an area of mid-level height falls to spread eastward over the deep south and northern Gulf. Net result is the formation of a surface low off the TX coast Sunday morning which from there tracks east or slightly south of due east across the central Gulf through Sunday night. On this track, the low stays well south of our coastal waters. An area of moisture and lift moves across the area Sunday, enough that forecasters will call for a high chance of showers. The highest coverage of rain though stays out over the Gulf, closer to the low track. Little change in highs for Saturday with Sunday`s numbers looking to hold mostly in the mid to upper 50s. Overnight lows will be cool but gradually moderate with each night. LONG TERM /Monday Through Thursday/...A short-wave upper level ridge translates eastward over the area Monday and Monday night favoring a return to a rain-free weather pattern. Heading into Tuesday, the extended range global spectral models shows next southern stream energy approaching the Lower MS River Valley. Timing differences are seen with the operational GFS much faster and more bullish with its solution of measurable rain Tuesday than the 23.12Z ECMWF outcome which is slower and not bringing in rain until Tuesday night. The National Blends came out completely rain-free Tuesday and have tweaked to add a small PoP by Tuesday afternoon to account for the slower ECMWF but also the GFS. The mid-week feature kicks out across the southeast Wednesday. There are differences in the height fields with the handling of next upper level storm system diving through the Plains beyond Wednesday, but an assessment of forecast moisture fields which are low favors a lowering in PoPs Wednesday night and Thursday. Daytime highs upper 50s to lower 60s Monday gradually lift into the lower to mid 60s mid week which trends a few degrees above seasonal. Overnight lows to gradually moderate into the mid to upper 40s interior to lower half of the 50s coast by the middle of the week. /10 MARINE...A moderate to occasionally strong southeast wind flow will become southerly this evening as a cold front approaches from the west. The Small Craft Advisory for the Florida coastal and open Gulf waters remains in effect through 9 PM this evening as well. The cold front will progress across the Gulf coast late tonight into tomorrow morning, followed by a light to moderate northwest to north flow through the remainder of the week. A light to moderate easterly wind flow is then expected by late weekend as an area of low pressure moves eastward across the Gulf. This will persist through early next week. /26 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...High Rip Current Risk through Friday afternoon for ALZ265-266. FL...High Rip Current Risk through Friday afternoon for FLZ202-204- 206. MS...None. GM...None. && $$ This product is also available on the web at:
Area Forecast Discussion
National Weather Service San Francisco Bay Area
948 AM PST Tue Jan 21 2020 .SYNOPSIS...Rain is forecast to spread from north to south across our area today as a weak weather system moves into northern California. Rainfall amounts will be light to locally moderate, with no significant weather impacts expected. Mostly dry and warmer conditions are then expected for the remainder of the work week, with rain likely to return over the upcoming weekend. && of 8:33 AM PST Tuesday...Radar reflectivity indicates some light rain this morning impacting parts of the North Bay, the San Francisco Peninsula, and the East Bay. Stations in the North Bay have registered anywhere from a few hundredths of an inch up to several tenths through 8 am PST. Periods of light and perhaps briefly moderate rain will continue off/on through the day, spreading from north to south as the day progresses. Main impacts will be the wet roadways during the commuting hours. Total rain amounts will be generally between 0.25 and 0.50 inches on average with higher amounts in the North Bay Mountains and Santa Cruz Mountains and lower amounts for locations south of Santa Cruz as well as in the rain-shadowed Santa Clara Valley. No major changes have been made to the short-term grids. For additional forecast details, please refer to the previous forecast discussion. .PREV DISCUSSION...As of 3:00 AM PST Tuesday...Primary short-term forecast concerns are potential impacts from the incoming weather system. Given that precipitation will be mostly light and winds won`t be a significant factor, the primary impacts will be wet roadways during the morning and afternoon/evening commutes. Current radar shows light rain just now beginning to move onshore in Sonoma County. This initial rainfall is associated with warm advection out ahead of the primary front that is still a ways offshore. Based on the latest HRRR and NAM, light rain will remain confined to the North Bay through the morning commute, and roads should remain dry from San Francisco southward through at least mid morning. The primary frontal rain band is expected to arrive in the North Bay by mid morning, causing rain rates to increase somewhat. Rain will then spread south through most of the rest of the SF Bay Area during the late morning and afternoon hours as the front sags south. Light rain will finally reach the Monterey Bay Area by early evening. Areas that will most likely experience wet roadways during the afternoon/evening commute are the central and southern SF Bay Area as well as locations near Monterey Bay. The NAM indicates that a couple of weak waves will develop offshore along the frontal boundary by late afternoon and early evening. This will result in the frontal boundary stalling across the South Bay and Monterey Bay Area from late afternoon through much of the overnight hours, and perhaps even until a few hours after sunrise Wednesday. However, the front is forecast to gradually dissipate overnight and so rain will mostly end by daybreak Wednesday. Rain totals through tonight are forecast to be a half inch or less in most areas. The North Bay Mountains and Santa Cruz Mountains could see locally up to an inch of rain. Dry conditions are forecast from Wednesday through Friday as upper level ridging over California deflects incoming Pacific systems to our north. The second half of the work week will also feature warming temperatures as H5 heights increase to 576 dm. High temperatures are forecast to be mostly in the 60s by Thursday and Friday. However, if persistent low clouds and fog develop around the Delta and locally into the North and East Bay Valleys, similar to what occurred over this past weekend, temperatures in those areas would remain in the 50s. The consensus of longer range deterministic models, as well as model ensemble means, is for the next system to bring rain to the northern portion of our forecast area on Saturday and then south through the rest of our area by Sunday. This weekend system looks slightly stronger and wetter than today`s system, but will not likely to have significant impacts. Dry weather is then expected to return by early next week. && of 9:48 AM PST Tuesday...For 18z TAFs. A weak frontal boundary slipping through the area today will bring a mix of low cigs and/or vsby to area terminals during passage, along with some light rain. Current satellite imagery is showing widespread overcast conditions throughout the Bay Area and increasing clouds for the Monterey terminals. STS is already reporting 2sm with cigs down to 600 feet. Winds ahead of the front will likely have some light to moderate wind shear, as the surface winds will generally be out of the south while winds up about 2000 feet will be from the southwest and gusting into the mid 30 knot range. Therefore, wind shear remains in the tafs for STS, OAK, and SFO. As this frontal boundary slips out of the area, high pressure will be building quickly in its wake. This could trap some of the low level moisture that the front is leaving behind which could yield some low vsby issues at many of the Bay Area terminals overnight. The main culprit will be STS. Otherwise clouds will be clearing. This really boils down to a timing issue as to when the ridge takes hold behind the front. Most tafs do show some kind of reduction in vsby and it may need to be drop even further in later issuance`s. Vicinity of KSFO...MVFR is expected to remain through the day with a possible brief drop to IFR as the front passes between about 02Z-06Z. Confidence is low with any drop to IFR (no matter how brief) and is not reflected in the taf at this time. This will need to be monitored to see if the front comes in any stronger to SFO than forecast. At this time, it is expected to break up to a degree over the coastal range. Regardless, look for some small drops in vsby and cigs during the core of frontal passage. Winds will come around from the south to a more north to northeasterly direction behind the front and are forecast to be light. This may cause some radiational fog to develop. As it stands right now, but post sunrise on Wednesday conditions look to be improving significantly. SFO Bridge Approach...Similar to KSFO. Monterey Bay Terminals...VFR-MVFR. Light SE winds this morning. Showers to arrive in the early evening with MVFR cigs. Only a slight drop in vsby is expected as showers limp through the area. Otherwise, look for VFR to prevail again by this time on Wednesday. && of 09:31 AM PST Tuesday...Expect moderate to locally breezy southerly winds through this morning as a cold front approaches and moves through the waters during the remainder of the day. A longer period northwest swell will build today before peaking midweek generating hazardous seas conditions for smaller vessels. Another long period northwest swell will then arrive later this week. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tday...SCA...Pigeon Pt to Pt Pinos 0-10 nm from 3 PM SCA...Pt Arena to Pt Reyes 0-10 nm SCA...Pt Reyes to Pigeon Pt 0-10 nm SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm SCA...Pt Arena to Pigeon Pt 10-60 nm SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm && $$ PUBLIC FORECAST: Rowe/Dykema AVIATION: BFG/Rowe MARINE: RGass Visit us at Follow us on Facebook, Twitter, and YouTube at: