Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/30/19

Area Forecast Discussion
National Weather Service Bismarck ND
951 PM CDT Mon Apr 29 2019 .UPDATE... Issued at 935 PM CDT Mon Apr 29 2019 High pressure continues to build over western and central North Dakota this evening. Skies have cleared quite a bit across the northwest and north central while clouds hold on in the south. We ended up lowering temperatures over the northwest and north central where we expect the best chance for an extended period of clear skies and light winds tonight. Kept temperatures close to the previous forecast elsewhere. A couple of the CAMS are indicating an area of fog from around Minot to Stanley, and this could certainly occur given the amount of moisture in the lower levels. Latest RAP forecast sounding at KMOT does show the potential for radiational fog via the crossover method which seems reasonable given current dewpoints and forecast low temperatures. Moisture is very shallow, so will just add a mention of patchy fog for now. Of coursre this could also hinder current forecast lows tonight, but overall think a lowering of temperatures north seems reasonable. UPDATE Issued at 627 PM CDT Mon Apr 29 2019 High pressure currently situated over far northeast Montana will drop south and east across the forecast area tonight. Made some minor adjustments to sky cover, with some clearing occurring in the north. Also updated the latest sensible weather elements and blended to early evening values. Will keep an eye on temperatures, especially across the north tonight with clearing skies and diminishing winds. Could see temperatures drop lower than forecast. && .SHORT TERM...(This evening through Tuesday) Issued at 219 PM CDT Mon Apr 29 2019 Latest visible satellite imagery shows cloudy to mostly cloudy sky conditions this afternoon. Following the NBM and visible imagery, northwest North Dakota will see a lot more sunshine as the afternoon progresses with much less elsewhere. Broad mid level ridging tonight will keep it dry, however, low clouds will begin to fill across our southern forecast zones as southwest flow aloft begins to push a few mid/upper level shortwaves towards western and central ND. Lows tonight will generally be in the 20s, to lower 30s far southern James River Valley. On Tuesday, large scale ascent will overspread the area during the day resulting in a chance of snow/rain in the morning, expanding and transitioning to rain central and south. The far north will see the lowest PoPs with this event. The shortwave exits Tuesday evening, however, another stronger shortwave via southwest flow is slated for Tuesday night and Wednesday. More details on this in the long term discussion. Another cool day Tuesday with highs in the upper 30s to mid 40s. .LONG TERM...(Tuesday night through Monday) Issued at 219 PM CDT Mon Apr 29 2019 From the short term, southwest flow aloft dominates Tuesday night through Wednesday night. A stronger mid level shortwave/700mb closed low approaches the southern border Tuesday night, then transitions towards the southern James River Valley by Wednesday night. Rain will change back to snow southwest Tuesday night through Wednesday morning. Gridded snowfall accumulations range from a tenth of an inch central to around 1 inch far southwest. Expect a good chance of rainshowers during the day Wednesday for most of the forecast area, however the northwest will see the lowest chances. Rainshowers will mix with and change to snow showers Wednesday night as they shift into the James River Valley, closer to the track of the 700mb low. Highs Wednesday will remain on the cool side with clouds and showers around. Expect highs in the 40s. The upper air pattern transitions from a southwest to westerly flow Thursday. A transitory mid-level ridge slides across and and results in a mostly sunny to partly cloudy day with highs in the 50s. Thursday night and Friday, another shortwave trough embedded within a west to northwest flow will produce a chance of showers and thunderstorms. MUCAPE looks meager at this point, however sufficient deep layer shear and mid level lapse rates might warrant a thunderstorm mention and will maintain this in the gridded data. Highs Friday will reach the mid 50s to lower 60s. For the weekend and into early next week, much cooler air can be expected with highs in the upper 40s to lower 50s. A progressive west to northwest flow with additional shortwaves will result in a chance of showers and perhaps some thunderstorms Friday night through Saturday. Sunday looks drier, then maybe another system Monday for a chance of showers per GFS/ECMWF. With a progressive flow in place, timing of successive waves this far out results in greater uncertainty. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 935 PM CDT Mon Apr 29 2019 VFR conditions at KISN and KMOT, with MVFR conditions at KDIK, KBIS and KJMS to begin the 00Z TAF period. Expect VFR to remain across the north tonight. MVFR will be dominant across southern TAF sites but could see a period of VFR ceilings late evening into the early morning hours. An advancing system from the southwest will bring MVFR conditions to the southern TAF sites around 12 UTC, if the already aren`t MVFR, and to near KISN and KMOT by 18-21 UTC Tuesday. Rain showers move into the southern TAF sites Tuesday afternoon. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...KS LONG TERM...KS AVIATION...TWH
Area Forecast Discussion
National Weather Service Charleston SC
906 PM EDT Mon Apr 29 2019 .SYNOPSIS... High pressure will prevail through Thursday. A trough of low pressure may develop off the coast Friday and linger into Saturday, then a cold front could move through Saturday night or Sunday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... The forecast is generally on track and only required minor adjustments for the late evening update. Atlantic high pressure will hold through the night. A robust pure sea breeze circulation will clear the far interior within the hour with modest southeast winds in place. The boundary layer looks to decouple overnight, first across the far interior, then working east closer to the coast after midnight. Low-level moisture is forecast to pool a bit under a strong nocturnal inversion, but RAP soundings suggest the moisture layer will remain paper thin with high 1000 hPA condensation pressure deficits. This scenario points to a shallow ground fog situation with some pockets of shallow, but locally dense fog developing near low-lying areas such as rivers, swamps, marshes and coastal waterways. Widespread dense fog does not look likely at this time, although some observation sites may very well report vsbys <1/4 mile, especially inland. Lows will range from the upper 50s/near 60 well inland to the upper 60s/near 70 at the beaches and Downtown Charleston. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... A deep layer ridge will continue anchored over the region through Wednesday, then begin to shift eastward into the Atlantic later Wednesday and Thursday. Have maintained above normal temperatures with no rainfall chances. Model soundings and SREF guidance indicating the potential for at least shallow, patchy fog each night. Have added patchy fog into the grids for Tuesday night, but held off for Wednesday night for now due to uncertainty and the fact that the models are showing tad more low level flow Wednesday night. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A relatively progressive pattern will develop late week into the weekend. A series of shortwaves will ripple through, though the best vorticity energy will stay to our north. A coastal trough may develop Friday and lift north Saturday, bringing enough low-level moisture for isolated showers/tstms. A cold front is progged to move through Saturday night or Sunday though rain chances do not look terribly impressive with this feature. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... VFR. Synoptic setup supports shallow ground fog early Tuesday morning. Vsbys should generally remain 6SM or greater, but a brief period of lower vsbys could occur just before daybreak at both KCHS and KSAV. At KSAV, would not be surprised to see vsbys jump around 08-11z as shallow fog banks develop near the sensor and site remains unaugmented by an observer prior to 11z. Extend Aviation Outlook: Patchy fog and some low clouds will be possible each night, with flight restrictions possible. Otherwise, VFR conditions rest of the period. Isolated afternoon showers possible both sites Friday and Saturday with the potential for brief flight restrictions possible. && .MARINE... Tonight: Atlantic high pressure will maintain a light onshore flow below 15 kt. Seas 1 to 2 ft. Tuesday through Saturday: Atlantic high pressure is expected to dominate through mid week, then high pressure will push further east into the Atlantic. South winds of 15 knots or less and seas 2 to 4 feet. Deeper moisture starts to return Friday and Saturday, which will bring the chance for some showers or isolated thunderstorms. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$
National Weather Service Cleveland OH
1020 PM EDT Mon Apr 29 2019 .SYNOPSIS... Low pressure will track east across northern Ohio this evening, reaching New England by Tuesday morning. A cold front will sag just south of the area tonight and remain stationary through Tuesday before lifting north as a warm front Tuesday night as low pressure moves into the western Great Lakes. The front will settle back into the area Wednesday and remain until another low moves through the area Thursday. && .NEAR TERM /THROUGH TUESDAY NIGHT/... The surface low has reached northeast Ohio in the vicinity of Akron, Canton, and Youngstown. This low will continue east and rain will remain east of the low. Have axed PoPs considerably across the area and removed all mention of thunder as this system exits the forecast area. Previous Discussion... As of the 3 PM hour this afternoon, compact convectively- enhanced remnant MCV/synoptic low was between KFWA/KMIE, quickly moving east towards the area. Scattered rain showers were moving northeast across northeast Ohio on the nose of a 850-700mb wind max, but are expected to slowly diminish as the jet becomes refocused near the synoptic low across western Ohio over the next couple hours. An area of stratiform rain with some embedded heavier showers on the northeast flank of the low will move eastward over the northern part of the area over the next few hours. Attention turns to potential convective development with the MCV/low across the western part of the area towards 22Z-00Z. Narrow corridor of instability is trying to race northeastward ahead of the system through southern Indiana into west central Ohio, with the surface warm front lifting into the southwest part of the CWA in another hour or two. Hi-res models have been struggling to handle this system, with the HRRR capturing a decent depiction of the current evolution, although lagging a few hours behind with the surface pressure center and ongoing stratiform precip. Although there is still a conditional marginal severe weather risk as highlighted by SPC, latest trends point towards the low/mid level forcing racing east and outrunning appropriate moisture/instability return for any significant or widespread convective development. There still could be an isolated cell or two that pops up near 00Z across the southern part of the area, but the window for severe weather will only persist for a couple of hours or less. Will continue to monitor these trends and latest observational data for hints of convective development, as even a minimal amount of instability will allow for potential severe storm development. Any severe weather threat should end across the local area by 03-04Z. The lagging cold front will sink south through tonight and should settle south of the area by early tomorrow morning. Dry conditions are anticipated through the early morning hours for much of the area until a mid level vort/speed max rides the front northeast across central Ohio tomorrow morning/early afternoon. The surface front will lift back north tomorrow evening as surface low pressure deepens over the southern Plains and tracks northeast into the western Great Lakes by Wednesday morning. Precip will be hit or miss through this period, with anticipated dry periods tomorrow and tomorrow night, with better rain chances moving just northwest of the area with the ramping low level jet. Will still carry some low chance/slight chance pops for southern areas Tuesday/western areas Tuesday night. Have lowered highs a touch on Tuesday with the boundary a bit farther south in recent model runs. Highs range from the low 50s north to the low 60s south. Temperatures will rise fairly rapidly after midnight Tuesday night with the warm front lifting north, but early lows in the upper 40s/mid 50s will rise to the mid/upper 50s by the morning. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... An upper level trough will dive into the Plains states Wednesday and slowly become negatively tilted by Wednesday night. The trough will cause cyclogenesis to take place over the middle Mississippi Valley region by Thursday. The surface low is expected to be relatively weak as the negatively tilted trough begins to become absorbed into another reinforcing upper level trough that will dig southeast. The weak surface low pressure system will move northeast into the Great Lakes by Friday morning. The low will cause some warm air advection to take place in earnest Wednesday and Thursday as a warm front lifts north of the area. A cold front trailing from the low will move east across the area Friday. As warm air advection takes place Wednesday, instability will increase across the forecast area. CAPE values increase across the area supporting the threat for thunderstorms. Instability also supports the threat for severe thunderstorms Wednesday and we are well into a marginal risk by then. The surface low pressure system and associated moisture will also support the threat for additional rainfall. Ground is somewhat saturated in some places allowing for good runoff. So, the threat exists for potential additional flooding of rivers and streams across the area through the end of the week. As far as temperatures go, due to the strong warm air advection expected Wednesday, we have a run at hitting 80 degrees in many areas Wednesday and well into the 70s for Thursday. Highs will cool off Friday as cold air advection develops across the area after the cold frontal passage. && .LONG TERM /FRIDAY THROUGH MONDAY/... Upper level flow will become transient over the extended periods. A blend of broad troughiness and ridging will move quickly east across the area during this period. A vigorous shortwave will move east across the central Great Lakes Saturday followed by a broad weak upper level ridge Saturday into Sunday. Otherwise, west to east flow develops with no ridging or troughing expected by Monday. Surface high pressure is expected to move east across the area Saturday into Saturday night. This will allow for another surge of warm air advection across the area Sunday into Sunday night ahead of a cold front. A cold front will sweep east across the forecast area Monday allowing for some cold air advection to take place. The weekend is looking relatively dry across the area due to the surface high pressure. A threat for showers will return Sunday night into Monday with the cold front. && .AVIATION /00Z Tuesday THROUGH Saturday/... Low pressure was located over mid-Ohio this evening and will bring variable conditions to the terminals for this evening into the overnight. Ahead of the low, a stratiform rain shield over the area has brought MVFR to occasional IFR visibilities to much of the area, but ceilings have not budged far from 4 kft. This area of rain has only a couple more hours to move through NE OH and NW PA and have timed as appropriate. Behind the low, ceilings are dropping to MVFR and eventually to IFR as a cold front moves through the area. Flow will shift around to the northeast tomorrow as the front continues south of the area and ceilings may improve to MVFR across the area. OUTLOOK...Non-VFR in periods of showers/thunderstorms through Thursday night. && .MARINE... Waves this afternoon into tonight will approach small craft advisory criteria but should be just below along the nearshore waters. Winds gradually diminish through Tuesday and become light northeast. An increasing easterly flow will develop in advance of the next system Tuesday night and then become southeast. Downsloping flow will occur along the shores of Erie County, Pennsylvania Wednesday morning and there is the possibility a small craft advisory may be needed in this location. Flow becomes southwest on the lake during the day Wednesday and could very well increase threat for small craft advisories over the rest of the lakeshore through evening. Otherwise, light and variable winds develop Thursday through Friday. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Greenawalt NEAR TERM...Greenawalt/Sefcovic SHORT TERM...Lombardy LONG TERM...Lombardy AVIATION...Sefcovic MARINE...Lombardy
Area Forecast Discussion
National Weather Service State College PA
1128 PM EDT Mon Apr 29 2019 .SYNOPSIS... A weak frontal system will move through the state overnight. The front will remain nearly stalled very near the forecast area keeping the region unsettled for much of the upcoming week. && .NEAR TERM /THROUGH TUESDAY/... Bands of showers continue to work across the northern half of the area. The HRRR favors the northern 2/3 of my CWA with best chance of some light rain this evening into the wee hours, before activity moves east after about 3-5 AM. The HREF is more generous with both aerial coverage as well as QPF, but the timing of the showers fading after midnight is very close to the same. Min temps tonight will range from the low-mid 40s across the Northern Mtns to between 50-55F across much of Southern PA. The HREF suggests just small chances for showers Tuesday in the wake of the weak front, so I trimmed POPs somewhat trying to be a bit more optimistic. Temps will peak into the 55-60 deg range across the north, and upper 60s to mid 70s in the south. && .SHORT TERM /TUESDAY NIGHT/... Another small area of showers and scattered thunderstorms will likely form in OH and wrn PA, and could slide into the western half of the CWA Tuesday evening. Min temps early Wed should be a few Deg F warmer than Monday night as layered clouds overspread the fcst area from the south and west as the pesky frontal boundary drifts back to the north and into PA. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Overall, an unsettled period still looks to be in store next week, with a frontal boundary in the vicinity of the Commonwealth much of the time. Also, zonal flow aloft will keep short-waves frequently zipping across the northern CONUS. Consequently, at least hit and miss showers will be in the forecast throughout the week. One area of uncertainty is how much cool air damming will prevail east of the higher ridges in central PA, particularly in the mid-week period. At this time, the national blend of models shows a pretty tight thermal gradient across central PA by mid- week, with highs in the 70s progged from the Lower Susquehanna Valley up across our western zones (the Allegheny ridges), with cooler low-mid 60s over most of the northern tier. The prospect for embedded thunderstorms should increase as we head towards Thursday, and a better push of warmer air occurs ahead of an approaching cold front. Behind the front, next weekend appears drier and cooler from this early vantage point. && .AVIATION /04Z TUESDAY THROUGH SATURDAY/... Low pressure lifting through upstate NY will spread showers across the region late this evening, affecting primarily northern Pa. However, the larger aviation concern will be an increasingly moist southeasterly flow ahead of this system, which will lead to lowering cigs across northern and eastern Pa, with IFR cigs likely late tonight over this area. The region least likely to experience significant reductions will be the south central part of the state from KUNV south through KAOO. A period of LLWS is possible across western Pa overnight, as strong winds aloft overspread the region. An examination of model soundings suggests the inversion height and shear will remain above 2000ft across the eastern half of the state. The low pressure system and associated showers/LLWS should have exited the region by dawn Tuesday. However, upsloping flow will likely yield lingering low cigs across the northern mountains (KBFD) and Laurel Highlands (KJST) into late morning. A drier northerly flow should result in continued improvement by afternoon, with even the N Mtns/Laurels becoming VFR. .Outlook... Wed...Low cigs possible, especially central mountains. Thu...AM low cigs/fog possible eastern Pa. Isolated PM tsra impacts Laurel Highlands/SC Mtns. Fri...AM low cigs/fog possible. Scattered PM tsra impacts possible. Sat...Showers/cig reductions possible, mainly southern Pa. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...La Corte NEAR TERM...La Corte SHORT TERM...Lambert LONG TERM...Jurewicz AVIATION...Fitzgerald
Area Forecast Discussion
National Weather Service Cheyenne WY
951 PM MDT Mon Apr 29 2019 .UPDATE... Issued at 938 PM MDT Mon Apr 29 2019 A couple areas of concern heading into the overnight period. There is potential for a band of heavy snow to develop across some parts of Carbon, Albany and Converse counties over the next few hours as low-level convergence & isentropic upglide become focused along an inverted surface trough expected to strengthen over these areas in the next several hours. High-resolution guidance suggests moderate to heavy precipitation banding, but still differ considerably with the precise location. It also remains to be seen just how long the heavier snow rates will be maintained, as this will play a role in the overall impacts on Tuesday morning. One other possible area of concern is the Platte River Valley around Scottsbluff w/ very good upvalley flow continuing through the night and the HRRR seeming to focus precipitation over this region. At this time however, do not believe that precipitation rates will be sufficient to warrant the issuance of a Winter Storm Warning. Nonetheless, the midnight crew will need to closely monitor trends in the next few hours. Looking a bit further ahead, some guidance remains very aggressive toward the Tuesday Night & early Wednesday system. We felt it best to address this system first, and then adjust headlines later with any new guidance over the next few shifts. UPDATE Issued at 514 PM MDT Mon Apr 29 2019 We have issued an update to add the city of Cheyenne to the Winter Storm Warning. A band of very heavy snow developed this afternoon, with rates of 2 to 3 inches per hour observed over the last couple of hours at peak intensity. Radar trends indicate the heaviest has moved eastward. However, some upstream enhancement is already seen across western Laramie County due to southeasterly low-lvl upslope flow. This should maintain a persistent light to moderate snowfall well into the evening and overnight. The heavy snowfall rates have caused roads to quickly become slick and snow covered, and thus we no longer anticipate melting to be a problem. Updated hazards have been sent. Forecast products will be updated shortly. Expect about 5-10 inches of snowfall in the Cheyenne area through Tue AM. && .SHORT TERM...(This evening through Wednesday) Issued at 330 PM MDT Mon Apr 29 2019 Challenging forecast over the next 48 hours as two separate disturbances move through the area. Winter headlines and snow amounts are the primary challenges. Surface low pressure currently analyzed over east/central Utah this afternoon. Fairly widespread moisture moving up through western Colorado into Carbon County this afternoon. Has been snowing fairly steadily over Laramie County this afternoon. Webcams showing snow covered roads up on the Summit. Water vapor imagery showing upper low still over southern California at 2PM this afternoon. Models in great agreement showing heavy precip developing somewhere west of the Laramie Range tonight. GFS/NAM/ECMWF/SREF showing 6 hour QPF values of 0.5 to 0.6 inches after 06Z...running through roughly 15Z Tuesday. This sets up somewhere from Douglas to Laramie and points west. Strong isentropic lift across this area. With up to an inch of liquid precip overnight...decided to upgrade the advisories to warnings for a few zones out there tonight. Evening shift will need to monitor trends on where exactly that band sets up for possible further upgrades. Could be some strong winds near Laramie tonight. GFS soundings showing winds right off the surface of 40-45kts that could create blowing snow and poor visibility as well. A brief break Tuesday afternoon before the second upper shortwave moves through Tuesday evening. This system impacts Converse and Niobrara Counties we will need to monitor for upgrades up there tomorrow night. .LONG TERM...(Wednesday night through Monday) Issued at 330 PM MDT Mon Apr 29 2019 Wednesday night/Thursday...Drying out for Wednesday night in the wake of the shortwave trough aloft. Brisk zonal flow aloft will prevail with limited low and mid level moisture producing dry conditions for Thursday. Definitely a warming trend with more sunshine and 700 mb temperatures near -1 Celsius. Friday...May see a few showers early in the day as another progressive shortwave trough aloft moves across our counties. Will be even more mild with 700 mb temperatures near 1 Celsius. Saturday...A slow warming trend continues as 700 mb temperatures rise to near 6 Celsius, yielding maximum temperatures in the 60s to lower 70s at lower elevations. Cyclonic flow aloft will continue some cloud cover, though precipitation looks unlikely with lack of lift. Sunday...Another cold front moves south across our counties, producing cooler temperatures, perhaps even cooler than we currently have in our forecast. At least a chance for some showers in the cool, moist upslope overridden by southwest flow aloft. Monday...With abundant cloud cover and moist southwest flow aloft, we expect to see at least scattered showers in the afternoon. Temperatures will be quite tricky with cloud cover, though will stick with highs in the 60s for now to blend well with our neighboring offices. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 403 PM MDT Mon Apr 29 2019 Wyoming TAFS...IFR at Cheyenne and Laramie until 15Z, then MVFR until 18Z, then VFR. MVFR at Rawlins until 06Z, then IFR until 13Z, then MVFR until 16Z, then VFR. Nebraska TAFS...MVFR at Chadron and Alliance until 18Z, then VFR. MVFR at Scottsbluff until 06Z, then IFR until 15Z, then MVFR until 18Z, then VFR. MVFR at Sidney until 02Z, then IFR until 15Z, then MVFR. && .FIRE WEATHER... Issued at 330 PM MDT Mon Apr 29 2019 Minimal fire weather concerns as accumulating snow spreads across southeast WYoming and Nebraska Panhandle. Cold temperatures will keep afternoon humidity on the high side and well above critical levels. No fire weather concerns expected the next several days. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Winter Weather Advisory until noon MDT Wednesday for WYZ101-102- 104-107>109-111-113-119. Winter Storm Warning until noon MDT Wednesday for WYZ103-105-106- 110-112-114>118. NE...Winter Weather Advisory until noon MDT Wednesday for NEZ002-003- 019>021-054-055-095-096. && $$ UPDATE...CLH SHORT TERM...GCC LONG TERM...RUBIN AVIATION...RUBIN FIRE WEATHER...GCC
Area Forecast Discussion
National Weather Service Dodge City KS
620 PM CDT Mon Apr 29 2019 ...Updated Aviation Discussion... .SHORT TERM...(This afternoon through Tuesday night) Issued at 1200 PM CDT Mon Apr 29 2019 The latest cold front continues to plow southward through West Texas at midday, with another round of strong north winds in progress. North winds will diminish rapidly this afternoon as the pressure gradient weakens. Afternoon temperatures will fall about 10 degrees short of late April normals, in the lower 60s. Tonight, increasing/lowering clouds and rain developing. Closed low near San Diego at midday will weaken into a progressive shortwave, arriving near the Four Corners at sunrise Tuesday. As this system approaches, all models saturate the lower atmosphere amid moist upslope and light NE winds. Stratus will prevail Tuesday morning, with widespread mist/drizzle and areas of fog. NAM is showing its typical drizzle QPF signature early Tuesday. Dynamic lift ahead of the approaching shortwave will arrive early Tuesday, with numerous rain showers expected to spread into SW Kansas. Latest HRRR iterations show this evolution nicely. Most models suggest QPF of about 0.25" will be a reasonable expectation at most locations, with heavier amounts of 1/2-2/3 inch favoring the southern zones. For many in SW Kansas, including Dodge City, this is the last chance to avoid April 2019 being one of the driest Aprils in history. It will not be the rain we need to make up for the dry month, but certainly a widespread one quarter inch would be beneficial to the spring`s young vegetation. Kept a small mention of thunder in the grids, with NAM depicting elevated CAPE up to 1000 J/kg above the stable boundary layer. Likely pop coverage is still justified in the grids. Tuesday afternoon, showers and thunderstorms may increase in vigor across the eastern zones ahead of strong shortwave ejecting through western Kansas. Instability will remain limited in SW KS, with any appreciable severe weather threat well east of our CWA. This said, several CAMs/NAM are suggesting we may have enough time to recover from morning rain/clouds to allow for isolated strong convective development in the afternoon. It`s a messy pattern with high uncertainty, but something we will be monitoring. Clouds, rain, and upslope easterly wind components will again hold temperatures well below normal for the last day of April, ranging from the 50s north to the 60s south. .LONG TERM...(Wednesday through Monday) Issued at 248 PM CDT Mon Apr 29 2019 Temperatures will have an opportunity to warm a few degrees Wednesday, ahead of lee side cyclogenesis near SE Colorado and the next approaching cold front. Will need to monitor for warm sector and instability placement again Wednesday afternoon, with SPC marginal/slight risks clipping the SE zones. The best probability of strong/severe convection will likely be across the SE zones Wednesday night, as the next cold front intercepts the moisture and instability axis. Otherwise, scattered showers and thunderstorms will accompany the cold front passage Wednesday night with more strong north winds. Cool stable high pressure will be in control Thursday, with sunshine, light E/NE winds, and temperatures several degrees below early May normals. A pleasant spring afternoon. Another passing disturbance may generate another round of scattered showers and thunderstorms during the Friday time frame as shown by 12z ECMWF, and model blended pops were accepted. Next weekend is expected to be mostly quiet and dry, with warmer afternoon temperatures well into the 70s. Synoptic pattern offered by 12z ECMWF is very quiet with regards to thunderstorm potential, with the stubborn Hudson Bay low persisting, and broad ridging building over the western U.S., forcing dry NW flow over the central plains. Model blend pops for the weekend were retained, but are likely overdone. Could see some weak convection arrive in the western counties from Colorado each evening, but not the caliber of convection we are accustomed to seeing in May. Early next week, medium range models depict a closed low sinking south across California on Monday. Eventually, this cyclone is expected to dig through the SW U.S. Tuesday, and eject onto the plains as a strong shortwave Wednesday, May 8th. This will most likely be our next episode of significant severe weather in/near SW KS. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 618 PM CDT Mon Apr 29 2019 IFR ceilings will develop after midnight as low level moisture increases across southwest and north central Kansas. Based on the latest BUFR soundings the VFR ceilings early this evening will lower into the MVFR category after 03z Tuesday and then lower to less than 1000 ft AGL after 06z Tuesday. The depth of this low level moisture will also be on the increase overnight with the chance for some drizzle or very light rain becoming possible towards daybreak. This low level moisture will be slow to erode but after 18z Tuesday ceilings will improve into the MVFR category. Winds overnight and Tuesday will be northeast at 10 to 15 knots. && .PRELIMINARY POINT TEMPS/POPS... DDC 44 64 44 69 / 70 60 20 20 GCK 43 59 42 67 / 70 50 20 20 EHA 43 73 44 74 / 80 20 10 10 LBL 44 71 45 74 / 80 30 20 10 HYS 43 54 40 59 / 50 60 20 20 P28 50 69 49 71 / 80 80 30 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Turner LONG TERM...Turner AVIATION...Burgert
Area Forecast Discussion
National Weather Service Goodland KS
825 PM MDT Mon Apr 29 2019 .UPDATE... Issued at 825 PM MDT Mon Apr 29 2019 Latest 00z NAM model as well as past several runs of the HRRR showing less precipitation potential compared to afternoon forecast requiring a lowering of pops overnight. Best 850-500mb moisture and forcing is generally north of the interstate overnight with perhaps an increase in coverage south of the interstate shortly after sunrise Tuesday as a pretty good area of moisture moves in from the southwest. HRRR model runs pretty bullish with 1km agl radar reflectivities but placement varies from run to run so confidence low right now in highest pop placement. Will maintain some light snow across the far western portion of the forecast area with under an inch accumulation still expected. Otherwise widespread low clouds will increase across the area overnight. Low temperatures range from the low to mid 30s in far eastern Colorado to the low 40s from Hill City to Leoti. Winds generally from the northeast to east-southeast at 10 to 15 mph. && .SHORT TERM...(This evening through Tuesday) Issued at 122 PM MDT Mon Apr 29 2019 As of 2 PM CDT, 1 PM MDT, skies across the Tri-State Region are partly to mostly cloudy as some mid-level clouds spread in from Colorado. Temperatures have been held in check for areas with more persistent cloud cover so there is a decent range...from the upper 30s in NE Colorado to the mid 50s in north central Kansas. North winds have weakened throughout the day, now in the 10-15 mph range. At the surface, a lee trough is deepening along the Rockies with surface high pressure moving out of the region to the east. Aloft, an upper level low is spinning along the California coast, heading east. A shortwave trough is moving out ahead of this low...and this is the disturbance that will bring us precipitation tonight. For tonight, the main concern will be the potential for some wintry precipitation. Overall, this is not a terribly impressive system so not expecting anything significant to occur. As the disturbance lifts through the High Plains, expect precipitation to develop along the Rockies, then spread northeast across northeast Colorado. Sounding profiles indicate a slight warm layer aloft but still well below 3C where full melting would occur. Soundings appear saturated so there should be ice in the column, so as long as temperatures drop enough (and they should although stratus may be a problem), then we should observe some snow. Wet bulb temperatures also go below 0C so that is another factor leaning towards a change to snow. With lower temperatures, there could be some frost in the area but thinking that won`t be the problem, the snow will. Across the rest of the area, expecting light showers to pass through. Latest trends in precipitation have lower amounts across the entire forecast area. Highest precipitation amounts will be along to generally south of HWY 40. In fact, some of the rain may actually be heavy drizzle which could lower visibility to the 3-5 mile range in a few spots. For tomorrow, precipitation spreads to the northeast east. However, low cloud cover should linger throughout most of the day behind the weak/stalled cold front. This will impact temperatures so decided to lower highs a few degrees from guidance due to the anticipated persistent cloud cover. Southeast winds will help bring some additional moisture into the area, setting the stage for precipitation development overnight. During the Tuesday night hours, anticipating a saturated low level in the atmosphere. Broad weak lift should be in place over the region. Without a discernible shortwave, not anticipating much in the way of shower activity. Any instability for thunderstorm activity will remain well to the south...over southwest Kansas. Sounding profiles show a saturated low layer with dry air aloft...from about 800 mb up. Therefore, with the broad lift, low level saturation, and upper level dry air, anticipating the development of drizzle across most of the area as the warm front retreats to the north. There may also be some fog so that is yet another thing to watch. With warm/moist air advection, am anticipating low temperatures to fall only into the upper 30s to low 40s. This would prevent any frost formation that may damage crops. .LONG TERM...(Wednesday through Monday) Issued at 117 PM MDT Mon Apr 29 2019 Expect an active pattern through Saturday as the models are showing an upper-level longwave trough over the western U.S. and a longwave ridge over the Eastern U.S. As the ridge builds the trough will move eastward and become elongated over the High Plains. This will produce mostly southwesterly-westerly winds aloft. Within this flow multiple shortwaves are expected to move across the forecast area. Currently, the forecast calls for a chance of rainshowers and slight chance of thunderstorms on Wednesday. Followed by frost wednesday night over the northwestern part of forecast area. The next round of shower and thunderstorms will be Thursday afternoon/evening through Friday morning followed by another round on Saturday. With this shortwaves expected to be fast moving, it is difficult to have confidence in the precipitation amounts. Beyond this coming up weekend, confidence is low. The models are showing an closed upper-level low, located over the Eastern Pacific, moving onshore; however, once onshore they are not in agreement with placement and intensity. So will wait and see how this system is handled in the next few model runs. Until then, will keep what Superblend gives. Afternoon temperatures will start out in the upper 50s on Wednesday and gradually reach the lower 70s by weekend. Meanwhile, the overnight lows will drop into the lower 30s on Wednesday night then hold steady in the lower to upper 40s for the rest of the extended. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 440 PM MDT Mon Apr 29 2019 For KGLD and KMCK, vfr conditions expected through about 08z at KGLD and 11z at KMCK before sub vfr cigs (stratus) move in from the south and continue through the remaining taf period. Winds generally from the northeast and east around 10kts taf issuance becoming more easterly at 12-15kts through much of the day before subsiding a bit from late afternoon through the end of the period. Any precipitation looks to hold off until around sunrise with multiple weather disturbances moving through providing a few chances for moisture. Its possible that the precipitation could improve conditions to vfr at times. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...99 SHORT TERM...RRH LONG TERM...BW AVIATION...99
Area Forecast Discussion
National Weather Service Grand Rapids MI
926 PM EDT Mon Apr 29 2019 LATEST UPDATE... Update .SYNOPSIS... Issued at 326 PM EDT Mon Apr 29 2019 -Soaking rain expected Tuesday night into Wednesday -Ponding of water on roads and fields is possible -Additional showers and storms possible Thursday && .UPDATE... Issued at 926 PM EDT Mon Apr 29 2019 Given the light winds and low ceilings already in place and all the rain that fell near and south of I-96 today, plus the fact that it was drizzling when I went outside a few minutes ago, it seems more than reasonable to add patchy drizzle and fog to the forecast overnight.So I did just that. Due to the low clouds, I do not expect dense fog, more of a 1 to 3 mile vis sort of fog. && .DISCUSSION...(This evening through next Monday) Issued at 326 PM EDT Mon Apr 29 2019 A classic late April / early May pattern is shaping up for this week across the Great Lakes region with several opportunities for showers and even some thunderstorms. The first round of rain is exiting the region and has laid out a swath of 0.50"-1.25" south of a Muskegon to St. Johns line. The heaviest amounts occurred from Kalamazoo to South Haven. There will be at least two more rounds of showers and some thunderstorms to contend with before week`s end that will impact the region. After a break in the rain through at least the first half of Tuesday, low level moisture advection begins in earnest Tuesday evening with PWAT values transitioning from around 0.60" to 1.25" with a robust LLJ of 50-60 kts. The upper level pattern reflects a familiar setup for several waves of rain to track through the region. Southwest flow aloft, a surge of Gulf moisture, and a surface warm front nearby combine to support an increased risk for soaking rainfall. There look to be several subtle 500 mb shortwaves moving through the region and the surface warm front will gradually lift north into southern Lower Michigan by Wednesday. A solid LLJ intersecting this boundary will ensure a blossoming of precipitation from Tuesday evening through Wednesday. MUCAPE inches up Tuesday night with some thunderstorms possible though we are not expecting widespread coverage of storms. A steady rain may be the most likely outcome. With bulk shear of 60 kts Tuesday night and unidirectional flow from 850 mb to 250 mb, there will likely be training showers and storms with little eastward propagation from where they set up. This points to some locally heavy rain and both the medium range guidance and hi-res models concur that a swath of 1"-2" is a likely outcome by Wednesday morning or early afternoon. The I-96 corridor and a county or two either side of it appears to be the favored location for the highest amounts. Given how quickly some locations achieved 1" of rain this morning in a less moist airmass, I would not be surprised at all if some locations get over 2" Tuesday night into Wednesday. By Wednesday afternoon and evening, any risk for strong to severe storms depends on whether or not the morning convection modulates the location of the warm front. Current projections are the combination of SBCAPE of a few hundred J/kg and bulk shear of 30-40 kts may support one or more sustained thunderstorms with marginally severe wind gusts south of I-96 Wednesday. With instability potentially a limiting factor, this risk does not look great but still something to watch should morning convection stay far enough north of our southeast forecast area near Marshall and Jackson, for example. A final round of showers and perhaps some thunderstorms may come through on Thursday, with lighter amounts expected in comparison to Tuesday/Wednesday. A good number of the EPS members have some precip moving through the day, though there are differences in timing that may be tough to resolve until we get closer to the event. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 7392 PM EDT Mon Apr 29 2019 Being north of a warm front that will not move north of our TAF sites in the next 36 hours, I believe IFR/MVFR cigs/vsbys are more likely than not into Wednesday morning. Winds will be light to calm at the surface tonight so with all the rain that fell early today, I could see a fog developing overnight. The low clouds however may keep that from happening. The NAM12 and HRRR and RAP model suggest dense fog near the Lake Michigan shore overnight tonight and given the light winds, I could see that happening so I do have thicker fog there. Tuesday the front moves back northward and will push showers and maybe some thunderstorms into the TAF sites overnight into Wednesday morning. I started the showers late in the afternoon for now. && .MARINE... Issued at 326 PM EDT Mon Apr 29 2019 Waves will be highest across western Lake Michigan given predominantly easterly flow. Onshore flow does return on Wednesday which may bump wave action into the 2-4 ft range. Currently we are not anticipating any SCAs to be needed. Also being closer to the front, the I-94 taf sites are more likely to go solid IFR tonight in fog and low clouds. && .HYDROLOGY... Issued at 326 PM EDT Mon Apr 29 2019 The Kalamazoo River basin received generally 0.50"-1.00" from this morning with roughly 0.40"-0.75" for the Grand River basin and around 0.25" for the southern stretch of the Muskegon River basin. All of these basins will be receiving 1"-2" of additional rain over the coming days. Rises on main stem rivers are expected though most stretches should likely hold below flood stage unless higher amounts occur. Smaller rivers and streams will experience rises as well and will be monitored. Nuisance ponding of water on roads and fields will be a likely outcome at times this week. Significant flooding is currently not anticipated. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...None. && $$ UPDATE...WDM SYNOPSIS...Hoving DISCUSSION...Hoving AVIATION...WDM HYDROLOGY...Hoving MARINE...Hoving
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
954 PM CDT Mon Apr 29 2019 .UPDATE... Issued at 938 PM CDT Mon Apr 29 2019 Thin band of showers and isolated thunderstorms is currently slowly moving northward across the central part of the CWA. This is occurring in a thin band of low level moisture convergence north of surface front which currently stretches across far southern Missouri and Illinois. This low level forcing will shift northward and increase overnight in response to increasing low level jet. This will cause an increase in showers and thunderstorms across central and northeast Missouri as well as west central Illinois which is already reflected well in going forecast. Flash flood watch starting over the northern third of the CWA still looks good as 00Z upper air analysis showed strong moisture transport into the area with KSGF PWATs around 1.5". Any thunderstorms over the northern part of the CWA overnight will have the potential for training. Britt && .SHORT TERM... (Through Late Tuesday Night) Issued at 409 PM CDT Mon Apr 29 2019 A cold front stretching from near Springfield Missouri northeast along the I-44 corridor and into south central Illinois near Effingham Illinois will continue to drift south for a few more hours this evening before moving back to the north up to near the Missouri/Iowa border by Tuesday afternoon. The northward movement is due in part to a 25-30kt low level jet tonight which will be blowing perpendicular to the baroclinic zone at 850 mb. All models are printing out QPF over a good portion of the area tonight to a greater or lesser extent due to the moisture convergence along the baroclinic zone. The NAM is particularly bullish late tonight strong moisture convergence across northeast Missouri into west central Illinois. Since some of those same areas received in excess of 1 inch (2+ in a few spots according to radar estimates) have issued a flash flood watch for those areas beginning at 06Z tonight. Attention turns to Tuesday and the severe weather threat as well as additional flooding. A shortwave aloft will be moving off the Rockies forcing cyclogenesis over the central Plains. The negatively tilted wave will move quickly to the northeast into the Missouri and Upper Mississippi Valley on Tuesday night. This will push the surface low northeast from northern Texas to southeast Iowa by 12Z Wednesday morning. 2200+ CAPE in the warm sector ahead of the low level cyclone in eastern Kansas and Missouri combined with 35-50kts of 0-6km shear will be more than enough to support severe thunderstorms on Tuesday afternoon and the CAMs are advertising a QLCS organizing in eastern Kansas or western Missouri and racing east during the late afternoon and evening. The latest HRRR looks especially strong with a prominent bow echo moving through central Missouri around 00Z. The exact timing and strength of the convection is of course difficult to determine and will depend greatly on how unstable the atmosphere can get at peak heating Tuesday afternoon. While a bow echo moving through central Missouri is certainly not good news, the silver lining may be that there will be less rain than expected earlier in northeast Missouri and west central Illinois on Tuesday night. looks like the outflow boundary from the QLCS may slow and take on an east-west orientation across southern Missouri including our eastern Ozark counties. Since the shortwave which is kicking this system off is lifting out rather than digging, the 850mb front is not expected to move south with the convection. Therefore, warm and moist advection will continue across the outflow boundary Tuesday night. The GFS and especially the NAM produce very strong moisture convergence across the Ozarks and the NAM prints out areas of 2 inch or greater QPF. While this may be too high, it`s not out of the realm of possibles considering precipitable water values in excess of 1.5 inches and warm cloud depths in excess of 10,000 feet. Given the potential for flash flooding not only overnight across the eastern Ozarks but also with heavy rain and lingering stratiform precip behind the QLCS, have expanded the flash flood watch further south to encompass all Missouri counties and parts of southwest Illinois as well beginning Tuesday afternoon. Both segments of the flash flood watch continue through Wednesday morning and the southern segment which includes central and eastern Missouri and parts of southwest Illinois continues until 12Z Thursday. Carney .LONG TERM... (Wednesday through Next Monday) Issued at 409 PM CDT Mon Apr 29 2019 An unsettled period will persist Wednesday into Thursday with potential for several rounds of showers and storms and heavy rain. A broad longwave trof will remain centered over the western U.S. during this time frame resulting in active southwest flow aloft with multiple disturbances in the flow aloft traversing the area and contributing to the development of convective storms. That said, while the broad scale pattern will largely be favorable for showers and storms, the convective scale and mesoscale details will ultimately impact the severe weather threat and most favorable location for heavy rain. A decaying/weakening MCS from Tuesday night should have passed through the area by daybreak Wednesday with a position expected from far southern IL/southeast MO extending southwestward into northern AR and eastern OK. There will also likely be a remnant large scale outflow boundary in this same area. It would seem only scattered showers will be impacting the immediate region during the first part of the morning, namely in the eastern CWA. So the big question will be the recovery potential for the remainder of the day on Wednesday and into the afternoon as the synoptic scale cold front begins to enter the northwest CWA. Both the GFS and NAM show relatively undiluted steep mid level lapse rates and with diurnal heating the air mass becomes quite unstable by afternoon, whereas the ECMWF is not quite as aggressive with instability. These model differences persist from Wednesday afternoon into Wednesday night. The GFS and NAM suggest a new round of convection developing late Wednesday afternoon/evening in central MO in association with a moderately strong and veering southwesterly LLJ, the aforementioned unstable air mass, and potentially in the region of the old retreating outflow and ahead of the slow eastward moving cold front. The mesoscale pattern and model QPF distribution would suggest upscale growth and the potential for either an elongated MCS or series of MCSs evolving along or south of I-70 on Wednesday night. Training potential and high moisture content would support a heavy rain threat within this region should the scenario evolve as envisioned. The instability and sufficiently strong deep layer shear would also support the potential for organized multicell storms from late afternoon into the evening. The caveat to all of the above heavy rain threat is the ECMWF generally has this scenario but focused much further south and removed from the CWA. Nonetheless we have the flash flood watch covering this time frame and location given the heavy rain and flood potential. The flow aloft will veer a bit more westerly on Thursday with the passage of the initial disturbance, allowing the cold front to finally move east and through the CWA by early Thursday evening. Depending on how the whole Wednesday night scenario evolves, showers and thunderstorms should be ongoing across eastern MO and western IL during the morning, shifting east and southeast with time as the cold front advances. I think the heaviest rain will have ended by this time frame. The flow aloft will be in transition Friday through the weekend into early next week with the eventual evolution to a split flow regime. The GFS and ECWMF do suggest that Friday/Friday night may not be dry as previously expected with both showing a low amplitude trof traversing the area and low level lift along and north of the boundary draped southern MO and southern IL. The GFS and ECWMF then diverge heading into the weekend and early next week with the large scale pattern and westerly or southwest flow aloft vs. northwest flow aloft. There does appear at this time to be another cold front passage centered sometime around Sunday, however uncertainty with accompanying precipitation with this front and into Monday is high and confidence low. Lastly...Present indications and RFC forecasts suggest a number of river forecast points on the Mississippi River above Alton will return to moderate and major flooding resulting from observed rainfall over the last 24 hours and additional rainfall forecast for the next 24 hours. All people with interests should closely monitor the forecasts and updates in the coming days due to the impacts from prolonged rainfall potential into the end of the week. Glass && .AVIATION... (For the 00z TAFs through 00z Tuesday Evening) Issued at 648 PM CDT Mon Apr 29 2019 Scattered showers and isolated thunderstorms over southern Missouri will move northward and affect the terminals later this evening and overnight, particularly KUIN and KCOU. The chance for showers and thunderstorms will continue through most of the period thereafter, though the chances at any once place is too low to have any more than VCSH or VCTS at the terminals. Better chance will come late tomorrow afternoon into tomorrow evening when a line of thunderstorms is expected to move into the area from the west. This line will have the potential to bring hail and gusty winds in excess of 35kts. MVFR ceilings are starting initially at KUIN, but are expected to spread during the night at all of the terminals, with some IFR ceilings. SPECIFICS FOR KSTL: Scattered showers and isolated thunderstorms over southern Missouri will move northward and affect the terminal later this evening and overnight, though the chance isn`t high enough to have more than VCTS. Low chances for showers and thunderstorms will continue through the rest of the night into Tuesday, though best chance will remain north of the terminal. Better chance will come late tomorrow afternoon into tomorrow evening when a line of thunderstorms is expected to move into the area from the west. This line will have the potential to bring hail and gusty winds in excess of 35kts. VFR ceilings are starting out at the terminal, but MVFR and IFR ceilings are expected at times throughout the rest of the period starting at 04Z. Britt && .LSX WATCHES/WARNINGS/ADVISORIES... MO...Flash Flood Watch from Tuesday afternoon through Thursday morning for Audrain MO-Boone MO-Callaway MO-Cole MO- Crawford MO-Franklin MO-Gasconade MO-Iron MO-Jefferson MO- Lincoln MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO- Reynolds MO-Saint Charles MO-Saint Francois MO-Saint Louis City MO-Saint Louis MO-Sainte Genevieve MO-Warren MO- Washington MO. Flash Flood Watch from 1 AM CDT Tuesday through Wednesday afternoon for Knox MO-Lewis MO-Marion MO-Monroe MO-Pike MO- Ralls MO-Shelby MO. IL...Flash Flood Watch from Tuesday afternoon through Thursday morning for Calhoun IL-Jersey IL-Madison IL-Monroe IL- Randolph IL-Saint Clair IL. Flash Flood Watch from 1 AM CDT Tuesday through Wednesday afternoon for Adams IL-Brown IL-Greene IL-Pike IL. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Midland/Odessa TX
638 PM CDT Mon Apr 29 2019 .DISCUSSION... See 00z aviation discussion below. && .AVIATION... Isolated TS will develop along a stationary front over the next few hours. TS has only been mentioned in the INK TAF at this time, and any storms could become severe with strong winds and large hail the main threats. Later tonight MVFR CIGs will affect sites east of the Pecos River with gusty west winds Tuesday pushing the clouds east and returning VFR conditions. Hennig && .PREV DISCUSSION... /issued 221 PM CDT Mon Apr 29 2019/ DISCUSSION... WV imagery shows the upper trough has made landfall in SoCal, leaving West texas and Southeast New Mexico under SW flow aloft. Closer to home, a sfc analysis at 17Z shows the cold front extending from as far SW as KCNM NE to KCDS and into OK. A dryline extended along the Texas portion of the Pecos Rvr to KFST before curving back SW into the Big Bend Area. This puts the triple point near Red Bluff Reservoir. In the warm sector, forecast soundings at KMAF at 00Z show mucapes in excess of 2000 J/kg, w/little in the way of CIN to surmount. Both the NAM and GFS depict mid-lvl lapse rates of 7-8 C/km, and wet-bulb zeros of 9-10 kft AGL, laying the ground work for more large hail along the front. Models differ a little on damaging wind potential, however. The NAM retains more moisture in the PBL, yielding dcapes of ~600 J/kg, whereas the GFS gives the classic inverted-V and dcapes ~1500 J/kg. Both models develop enough 0-1km helicities along the cold front that a tornado can`t be ruled out, although the threat looks confined to our top two tiers of counties in West Texas. All that`s needed at the moment is to overcome the cap, which is still holding at 19Z. Hires models like the HRRR initiate convection 22-23Z, but otherwise look unimpressive, whereas the NAM/GFS are a bit more widespread. Convection overnight should remain along/east of the Pecos. Overnight, the trough is forecast to open and move to the Four Corners by 12Z Tue. Leeside troughing will induce SW sfc flow, and mix the dryline east, confining further chances of convection along the ern zones. Marginal high winds will be possible in the Guadalupes, and we`ll issue a watch for this. For the rest of the week, zonal flow aloft is anticipated, w/the dryline developing over the ern half of the CWA each day, and a chance of convection along and east of this feature each day. A weak cold front tries to muscle in on Thursday, but looks dry and will bring temps down to near-normal Fri/Sat. Thursday night/Friday, the dryline will surge up against the wrn mtns, increasing convective chances a little further west into the CWA. Chances then generally drop off over the weekend, w/above-normal temps returning. && .PRELIMINARY POINT TEMPS/POPS... Big Spring 62 87 61 88 / 40 20 10 20 Carlsbad 59 84 54 88 / 10 0 0 0 Dryden 65 92 65 90 / 0 0 30 20 Fort Stockton 63 91 59 88 / 0 0 20 10 Guadalupe Pass 58 77 56 80 / 0 0 0 0 Hobbs 57 83 53 86 / 30 0 0 0 Marfa 51 83 48 82 / 0 0 0 0 Midland Intl Airport 63 88 60 89 / 20 10 10 10 Odessa 63 88 60 89 / 20 10 10 10 Wink 62 89 56 90 / 10 0 0 0 && .MAF WATCHES/WARNINGS/ADVISORIES... NM...High Wind Watch from Tuesday morning through Tuesday afternoon for Guadalupe Mountains of Eddy County. TX...High Wind Watch from Tuesday morning through Tuesday afternoon for Guadalupe Mountains Above 7000 Feet-Guadalupe and Delaware Mountains. && $$ 99/99/10
Area Forecast Discussion
National Weather Service Paducah KY
718 PM CDT Mon Apr 29 2019 .UPDATE... Issued at 718 PM CDT Mon Apr 29 2019 Early evening update for the remainder of tonight to reflect elevated convective trends overnight. May need to make a second adjustment later this evening to refine temperature trends, especially for the northern sections of the WFO PAH forecast area. KSGF sounding a little more representative (versus KLZK sounding) of the upstream moisture and instability advecting into parts of the WFO PAH forecast area overnight. KSGF sounding suggesting the best saturation in the 700-500 mb (roughly 8-18kft agl layer) with 7.5C/km lapse rate in this layer. Some elevated CAPE above 12kft (near the freezing level on KSGF sounding). Local VAD (Velocity Azimuth Displays) from the local radars KPAH (Paducah), KHPX (Fort Campbell), and KVWX (Evansville/Fort Branch) show some noticeable veering of 25-35 knots between 925-500 mb, hinting at warm advection aloft. The ESRL HRRR, HRRR, and RAP CAM`s appear to be initializing well with the current convection and expected location of frontal zone the last few hours and were used as a template for overnight convective activity. Considering the elevated instability in the aforementioned layer, will keep a small mention of showers and thunderstorms over southeast Missouri into southern Illinois this evening, with pockets of light rain or isolated elevated thunderstorms overnight further east. UPDATE Issued at 558 PM CDT Mon Apr 29 2019 Updated aviation discussion for the 00 UTC TAF issuance. && .SHORT TERM...(THIS EVENING THROUGH TONIGHT) ISSUED AT 219 PM CDT MON APR 29 2019 High confidence in the short term. A warm front had lifted north of the area today providing clouds and sprinkles this morning. The clouds will move out this afternoon with gusty south winds in its wake. Tonight we will lose the gusts and clouds will begin to return to the region. This front will stall along our northwest periphery tonight as a surface low lifts northeast along the front. This could allow a chance of rain showers and possibly a thunderstorm along our northwest. Mainly along a line from the Ozarks to the Wabash River Valley. Temperatures will be little warmer in the warm fronts wake and overnight lows will range from 60 to 65 across the area. .LONG TERM...(Tuesday THROUGH Monday) ISSUED AT 219 PM CDT MON APR 29 2019 Models are in general agreement through Friday and after that only slightly diverge. Overall pattern at 500H has a trough over the west coast with some ridging over the eastern US. Very little change through Friday however minor ripples in the flow will determine the precipitation chances. Essentially an unsettled pattern. The northwest sections may see a shower or thunderstorm tomorrow and this will gradually spread east Tuesday Night and Wednesday as one of the weak waves moves in from the southwest. Better chances arrive Wednesday Night and Thursday as a stronger wave rotates up from the southwest trough. A slight increase in the ridge along the east coast during that time will help to sharpen the wave and increase the dynamics over the region. We are in a marginal risk for severe weather Wednesday and Wednesday night in part due to the increased dynamics creating better shear. Cloud cover and precipitation will help determine the amount of instability for the shear to work with. This is the time of year when instability becomes increasing tied to diurnal cycle and the question becomes more about shear. The best combination after mid week looks to be Saturday over the I-64 area. Things will likely change before we get to that time. Might be a dry period Saturday Night into early Sunday before more storms move in. && .AVIATION... Issued at 558 PM CDT Mon Apr 29 2019 MVRF to VFR conditions expected through the TAF issuance period. Winds will relax tonight, generally remaining southwesterly around 5 to 10 kts. Winds will increase after 18z at most sites, with sustained winds of 11 to 15 kts and gusts of 19 to 22 kts possible. At KMVN, the warm front may sag south around 9z, shifting winds back to easterly, with a few showers possible. Small possibility the front could reach KEVV/KOWB as well, but confidence in this solution is low, so for now will monitor for possible adjustments for the next TAF issuance. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ UPDATE...Smith SHORT TERM...KH LONG TERM...PS AVIATION...DWS
Area Forecast Discussion
National Weather Service Shreveport LA
1017 PM CDT Mon Apr 29 2019 .SHORT TERM.../Tonight/ Quiet conditions remain this evening despite the deepening low level moisture advection regime in place, as evidenced in the 00Z KSHV raob which depicts a moist lyr up to 7kft. While much of the cu field has diminished since the setting sun, the RGB satellite imagery indicates a stratocu field beginning to advect N into Deep E TX and SW LA this evening, with a developing 30-35kt Srly LLJ advecting these low clouds quickly N across much of the region overnight. Both the 18Z GFS and 00Z NAM depict the H850 moisture lyr deepening overnight especially over E TX/SE OK, as a weak mid level shortwave ejects NE into E TX late tonight. This could result in isolated -SHRA development over E TX/SE OK late tonight beneath the capping inversion near 790 mb, which has already developed just NE of DFW and farther W towards SPS and Srn OK, and thus have maintained slight chance pops for these areas overnight. This is also supported by the latest HRRR run, which does begin to ramp up sct convection by/after 12Z Tuesday across portions of NE TX/SE OK through midmorning before quickly shifting N. Did trim pops back a tad over NW LA/SW AR Tuesday morning, before sct convection increases during the afternoon as a stronger shortwave trough ejects NE across the middle Red River Valley of N TX/Srn OK, with strong to svr convection increasing over these areas. Also made a few minor tweaks to the min temps tonight, mainly to lower temps a tad over Scntrl AR/Ern sections of Ncntrl LA, where the short term progs are in agreement with some drier air advecting NNW into the Lower MS Valley late tonight around the SE CONUS ridging in place. Otherwise, the remainder of the forecast is on track. Zone update already out...grids will be available shortly. 15 && .PREV DISCUSSION... /issued 700 PM CDT Mon Apr 29 2019/ AVIATION... VFR conditions should continue through much of the evening with a mix of sct cu and cirrus, although MVFR cigs are expected to develop by mid evening over SE TX/SW LA, and quickly spread N into Lower E TX S of I-20 as well as Wrn LA by late evening. These cigs should primarily affect LFK initially, followed by the TYR/GGG/SHV/MLU terminals by/shortly after 06Z, and the SW AR terminals by/after 08Z. Some isolated -SHRA may develop late tonight across portions of E TX/SE OK, but have not included mention into the E TX terminals attm given the low confidence. While these cigs should linger through much of the morning Tuesday, some drier air rounding the Wrn periphery of the large scale ridging in place over the SE CONUS is expected to advect NNW into the Lower MS Valley by/prior to daybreak Tuesday, resulting in the lower cigs scattering out as MLU initially, and eventually ELD around mid- morning. Elsewhere, the MVFR cigs should lift/become VFR by midday/early afternoon, as this drier air is mixed farther NNW, allowing for the tight pressure gradient to mix stronger winds down to the sfc by mid to late morning areawide. Thus, SSE winds 5-10kts tonight will become S and increase to 12-18kts by 15Z, with gusts to 25-30kts possible across much of E TX/SW AR/Wrn LA, and slightly weaker gusts to 20kts over Scntrl AR/Ncntrl LA. Isolated convection will remain possible Tuesday afternoon over portions of NE TX/SE OK/adjacent sections of SW AR, but should remain NNW of the TYR/TXK terminals. /15/ && .PRELIMINARY POINT TEMPS/POPS... SHV 69 84 69 83 / 10 10 30 40 MLU 66 84 68 85 / 5 10 10 20 DEQ 67 81 67 78 / 10 50 70 70 TXK 68 82 69 80 / 10 30 40 60 ELD 66 85 68 82 / 5 10 20 40 TYR 71 83 71 81 / 20 30 40 60 GGG 70 84 70 82 / 20 20 40 60 LFK 70 84 71 84 / 20 10 20 30 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 15
Area Forecast Discussion
National Weather Service Sacramento CA
310 PM PDT Mon Apr 29 2019 .SYNOPSIS... Cooling trend early this week with temperatures near or a little below average by Tuesday. Dry conditions except for a chance of showers or isolated thunderstorms over the foothills and mountains through Tuesday. Temperatures trend warmer throughout the week with a chance for showers returning to the higher terrain this weekend. && .DISCUSSION... Northern California remains in a split flow regime as one closed low moves toward western Arizona while a longwave trough to the north will cross the region on Tuesday. Currently, terrain induced cumulus fields are evident in GOES-17 visible imagery with the better instability over the northern Sierra. Based on a lack of echoes showing up on local radars, capping is likely an impedance from shower development. Recent high-resolutions models show mixed signals in forming such showers. Most notably, the last several HRRR runs keep the Sierra dry through the peak diurnal heating cycle. By Tuesday morning, a positively-tilted trough will swing through the Central Great Basin allowing for increased cloud cover across the region. The stronger ascent is likely to remain east of I-5 keeping shower chances highest from the foothills eastward. Limited moisture will keep precipitation amounts on the lower side, generally maximizing up to a third of an inch over Sierra and Plumas Counties. Widespread cloud cover should preclude any discernible thunderstorm threats. Over elevations 7,000 feet and above, some light snowfall accumulations perhaps up to an inch will be possible. Tuesday will be the coolest day of the week given cold advection occurring in the wake of the trough passage. Highs between 70 and 75 will be commonplace over the Valley while the foothills remain in the mid 50s to lower 60s. Temperatures will gradually rise throughout the week in response to a building ridge over the southwestern U.S. Highs back into the low 80s should return to the Valley by Thursday. ~BRO && .EXTENDED DISCUSSION (Friday THROUGH Monday) Dry weather continues Friday as slight upper ridging resides over northern California ahead of closed low moving towards the area this weekend. Ensembles bring the best chances for mountain/foothill precipitation late Saturday night through Sunday. Rain chances do look to continue through the beginning of next week as models tend to differ on how this closed low will track. As for temperatures, Valley highs in the low to mid 80s on Friday will gradually drop into the upper 70s by Sunday and Monday. && .AVIATION... VFR conditions expected over interior NorCal except for areas of showers and thunderstorms across the higher terrain. These would be primarily south of Highway 50 through 03Z this evening. Surface winds remain below 12 knots except local southwesterly gusts up to 27 knots are possible across the Delta through the late evening. && && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Tulsa OK
934 PM CDT Mon Apr 29 2019 ...UPDATE... .DISCUSSION... This evening the surface frontal boundary was positioned from far West Texas to South Central Oklahoma into Northeast Oklahoma...just south of the Interstate 44 corridor...and extended northeast into Southern Missouri. Scattered areas of light rain/drizzle have been observed over parts of Eastern Oklahoma and Northwest Arkansas within an area of warm advection. Further south into Western Texas...showers and thunderstorms were developing along/near the surface boundary where the surface instability was maximized and an upper level vort max currently resided. Overnight tonight...the surface boundary is expected to stall near its current position and then slowly retreat northward slightly late tonight/early Tuesday morning just north of the Interstate 44 corridor. Also overnight...the upper level vort max is forecast to lift northeast into Eastern Oklahoma late tonight while at the same time an increasing low level jet looks to lift into the CWA. The combination of these two features along with a weakening cap forecast over elevated instability will allow for an increase in thunderstorm potential mainly across Northeast Oklahoma where the surface boundary sets up. Have leaned toward the latest HRRR with increasing pops/thunder after 08-09z. In response...a limited severe weather potential will be possible with large hail and locally damaging winds the main threats...with the greater potential in Northeast Oklahoma near the boundary. With the northward push of the front...surface temps/dewpoints look to rise slightly late tonight especially just behind the frontal passage. Low temps look to range from around 60 degrees near the Kansas border to the upper 60s in Southeast Oklahoma. By 12z Tuesday...the upper 60s look to reach back into parts of Northeast Oklahoma. Thus for the evening update...have adjusted hourly pops and temps based the mentioned above...while added minor tweaks to winds/dewpoints based on latest trends and observations. With the forecasted rainfall..will leave current flash flood watch as is for now. && .PRELIMINARY POINT TEMPS/POPS... TUL 64 76 63 81 / 70 90 80 30 FSM 67 81 66 80 / 20 70 90 50 MLC 68 78 66 78 / 30 80 70 40 BVO 61 75 61 80 / 90 90 80 40 FYV 63 75 65 76 / 20 80 90 40 BYV 64 77 64 78 / 20 60 80 40 MKO 65 76 65 78 / 40 80 80 30 MIO 63 75 62 78 / 50 90 90 40 F10 67 77 65 79 / 60 80 80 40 HHW 68 78 67 77 / 30 70 70 60 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...Flash Flood Watch from 1 AM CDT Tuesday through Wednesday morning for OKZ054>064-067>069. AR...Flash Flood Watch from 1 AM CDT Tuesday through Wednesday morning for ARZ001-002-010-011. && $$ SHORT TERM...20