####018005273#### FXUS63 KIND 260435 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 1235 AM EDT Fri Apr 26 2024 .KEY MESSAGES... - Active pattern returns Friday into next week with above normal temperatures and frequent storm chances && .FORECAST UPDATE... Issued at 933 PM EDT Thu Apr 25 2024 Quiet evening continues as the region remains under the influence of high pressure to the northeast. Northern fringes of a broad cloud shield remains across the southwest half of the forecast area. These clouds are associated with an upper wave tracking through the Ozarks and ahead of a warm front. Temperatures ranged generally from the upper 40s to the mid 50s at 01Z. The forecast is in great shape for the overnight. The cloud shield will persist across southwest counties as the upper wave moves into the lower Ohio Valley...but mostly clear skies are expected elsewhere for much of the night. Lows will fall back into the upper 30s over the far northeast with 40s elsewhere. Not out of the question that isolated pockets of frost will form in the predawn hours mainly over portions of Delaware and Randolph Cos. Zone and grid forecasts out. && .SHORT TERM (This evening through Friday)... Issued at 221 PM EDT Thu Apr 25 2024 Rest of This Afternoon and Tonight... High pressure will remain in control at the surface, with upper ridging aloft. Thus, only some high clouds are expected at times through tonight. Cool temperatures will continue overnight, with lows in the upper 30s to middle 40s. Friday... A warm front will approach central Indiana during the day. 850mb winds will be from the southwest and gradually increasing in speed. This will bring in some moisture to the area. Isentropic lift will increase ahead of the warm front, and some upper level energy moving in behind the exiting upper ridge will add to the forcing. There looks to be adequate moisture and forcing for likely PoPs across the western forecast area, with lower PoPs east where moisture will be less. Some weak instability will move into portions of the south and west, so an isolated thunderstorm will be possible there. Temperatures will be warmer, with highs mainly in the 60s. && .LONG TERM (Friday night through Thursday)... Issued at 221 PM EDT Thu Apr 25 2024 By Saturday, central Indiana should be well positioned inside the warm sector, with surface temperatures reaching the upper 70s to low 80s Saturday afternoon. Temperatures should increase even further into Sunday as southerly low level winds increase. The current expectation is for highs in the low 80s on Sunday, but the daily record of 86 for Indianapolis is not out of reach, depending on cloud cover from upstream MCSs. Besides a residual 800-700mb boundary the overall environment will lack sufficient lift for convection. This should keep conditions dry, but a few weak elevated showers cannot be ruled out. Given the high probability of robust upstream convection over (MO/IA), a few left over boundaries or upscale growth into the Ohio Valley could change this current line of thinking. Best chances for any thunderstorms would likely be over western portions of Indiana. Late Sunday through early next week, a second shortwave will approach from the west, along with a trailing frontal providing an increased thunderstorm threat. Its still too far out to determine severity, but current parameter spacing expectations could lead to deep convection and a non-zero severe threat. This should become more clear in the coming days. Day 8-14: Multi-model ensemble mean continues to show strong signal for above normal temperatures. No large-scale systems appear present to produce widespread/significant precipitation, so smaller scale features interacting with instability look to be the primary impetus for convection. So, near or below normal precipitation is expected during this period. && .AVIATION (06Z TAF Issuance)... Issued at 1235 AM EDT Fri Apr 26 2024 Impacts: - VFR Conditions expected overnight and on Friday Morning. - Showers possible Friday afternoon along with possible high MVFR Cigs. Discussion: GOES16 shows high clouds over the middle Mississippi Valley spreading east across the TAF sites. These clouds were associated with an upper wave that was found over the plains. This feature is expected to advance east, allowing the high clouds to continue to overspread the TAF sites through through the overnight hours. As the best forcing arrives on Friday afternoon scattered showers are expected. Forecast soundings at that time show deep saturation arriving by mid to late afternoon. Hence have used vcsh mention for a window along with high MVFR Cigs into the evening to account what should be light precip amounts. Confidence for specific timing remains low, thus VCSH seems the best route at this time. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Ryan SHORT TERM...50 LONG TERM...Updike AVIATION...Puma ####018005765#### FXUS63 KUNR 260436 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 1036 PM MDT Thu Apr 25 2024 .KEY MESSAGES... - Fairly widespread rainfall at times from Friday through much of the weekend, especially the Black Hills and eastward. - Warmer and drier conditions move in for much of next week. && .DISCUSSION...(This Evening Through Thursday) Issued at 228 PM MDT Thu Apr 25 2024 Current surface analysis shows low pressure over far east central WY, with Pacific cold front stretching from far western ND to far eastern WY. Upper level analysis shows trough over the Great Basin to Four Corners region, with developing low pressure over northeast AZ. Skies are variably cloudy, with the most clouds over northeast WY and far western SD. KUDX radar shows scattered to numerous showers and thunderstorms from northeast WY to the Black Hills area and northwest SD as stronger energy aloft pushes through western portions of the CWA. Temps are mostly in the 60s and lower 70s, with some 50s over the Black Hills and rain cooled areas. Brisk southeasterly winds are gusting to over 35 mph across central SD, with lighter and more variable winds to the west. Active weather pattern taking shape for the next several days as a couple of upper level systems cross the region. Any severe weather potential will be confined to the next several hours, with the heaviest rain potential expected through Friday as the first upper low approaches and passes over the region. Most favorable CAPE this afternoon has been over and east of the Black Hills, ahead of the front, with values around 1000 j/kg. Shear is rather weak in many areas, so individual storms have been pulsy in nature and not very long-lived, producing smaller hail for the most part. Various CAMS show numerous storms continuing to develop through the afternoon along and ahead of the front, trying to consolidate into at least a broken line of storms along the front by late afternoon/early evening. Marginally severe hail and strong winds would be the main threats with stronger storms through at least late afternoon, with gusty winds perhaps a threat into the early evening over portions of the western SD plains if a more organized line of storms did develop. With precipitable water values up to 150 percent of average, heavy rain will accompany the stronger storms as well. Initial activity with the cold front should shift east of the forecast area toward midnight. Upper low moves into the central Plains later tonight and somewhere across central NE/eastern SD on Friday. Showers and some embedded thunderstorms will wrap north-northwestward into the forecast area late tonight and Friday, especially for the Black Hills area and eastward. There appears to be at least a slightly further south and east trend to the low track for Friday in the EC and now the latest GFS, which would shift the heavier rainfall potential a bit further east onto the western SD plains Friday. Right now, probabilities are 40 to 70 percent for an inch or more of rainfall Friday into Friday night for the northern Black Hills and much of the west central to south central SD plains. It will be breezy and cooler Friday, with highs in the 50s and lower 60s. Lingering areas of lighter rainfall can be expected Friday night into Saturday, especially for the Black Hills area. Even cooler air pushes in for the weekend, with highs only in the mid 40s to mid 50s, 40s over the Black Hills. As the first upper low weakens and departs the region, a second one develops over the central Rockies Saturday and moves northeast across nearly the same areas as the first one Saturday night and Sunday. This one looks to be somewhat quicker moving and its pcpn shield not quite as big. Best chances for more significant rainfall later Saturday night into Sunday will be across south central SD, with mostly light rainfall elsewhere. Not much, if any, thunder expected with the second system. There could be a little bit of snow across the higher Black Hills Saturday night into Sunday, but any accumulations look to be very minor. Breezy north to northeast winds will persist through the weekend. After this system exits the region Sunday night, near zonal flow is expected to develop early next week. Above average temps will quickly return to the area Monday and likely persist through the week. Another low pressure system is progged to develop over the northern Rockies and track north of the region Monday night and Tuesday. There will be chances for showers and a few thunderstorms late Monday into Tuesday, mainly across the Black Hills and northern portions of the CWA. A building ridge behind this system should bring mild and mainly dry conditions midweek, with the possibility of a cold front passage in the Friday timeframe. && .AVIATION...(For the 06Z TAFS Through 06Z Friday Night) Issued At 1033 PM MDT Thu Apr 25 2024 Widespread MVFR/local IFR conditions expected tonight with an expanding area of stratus on the SD plains. Showers and isolated thunderstorms will linger over south central SD through the night. Northerly winds will increase to 15-25 kts with gusts around 35 kts Friday morning with showers continuing on the SD plains, shifting to more isolated activity to the west. Mainly VFR conds expected over northeast WY. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION/KEY MESSAGES...26 AVIATION...JC ####018008099#### FXUS64 KHGX 260437 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 1137 PM CDT Thu Apr 25 2024 ...New AVIATION... .AVIATION... (03Z TAF Amendment) Issued at 1137 PM CDT Thu Apr 25 2024 MVFR ceilings are filling in across the area and will persist well into mid-late morning for most locations, and might not lift much at all closer to the coast during the day. There will be a few weak impulses moving overhead and can rule out an iso-sct shra/tstm but tough to pinpoint details (very unlikely they'd be impactful anyway). Other than ceilings, main aviation hazard will be gusty sse winds. Once we get some mixing during the daylight hours, we'll probably seen frequent gusts 20-30kt. MVFR ceilings will spread back in from south-north Fri evening. 47 && .UPDATE... Issued at 547 PM CDT Thu Apr 25 2024 The past 06z/12z/18z HRRR runs have shown some general consistency showing some iso-sct precip being a possibility as a few mid/upper impulses move across parts of the area during the day tomorrow. Went ahead and threw some low POPs in the grids down to about the US59/I69 corridor just to get the mention in the fcst. 47 && .SHORT TERM... (This evening through Friday Night) Issued at 257 PM CDT Thu Apr 25 2024 If you've been outside this afternoon, then I'm sure you've noticed that it's a bit breezy out there. Latest surface analysis shows surface low pressure beginning to develop on the lee side of the Rockies, and the 12Z UA obs plot shows a LLJ developing out in Central Texas earlier this morning. This LLJ will steadily slide eastward and will make it over the Brazos Valley by later this afternoon. It'll start out as 25-35 kts this afternoon, then increasing to 35-45 kts by tonight. This combined with the tightening pressure gradient from the developing surface low will lead to elevated winds prevailing throughout the short term period. The main ridge axis will shift off to the east later this afternoon as an upper level trough transitions from the Four Corners region to the Central Plains. Embedded shortwaves within the ridge will attempt to develop some isolated showers, but it'll have a VERY tough time doing so with a capping inversion aloft persisting. The best chances of this occuring will be west of I-45 through this afternoon. High temperatures today will reach the low to mid 80s. Still expecting low temperatures tonight to drop into the low 70s due to increasing low-level clouds and elevated winds persisting. Southwesterly flow aloft is firmly established by Friday as the upper level trough evolves to have an embedded upper level low. Surface low pressure drifts northeastward on Friday causing the associated frontal boundary to become quasi-stationary well to our west. With increasing PVA and elevated PW values in the 1.4"-1.7" range north of I-10 (90th percentile: ~1.61"), some showers/storms are possible to develop along the tail-end of a convective line advancing ahead of the front. Anything along this line will have to battle a capping inversion to survive, but this cap is weaker over the Brazos Valley. There is plenty of instability in place along with steep 700-500mb lapse rates, so if anything manages to survive long enough in our area there is potential for a storm or two to maintain/become strong to severe. As a result, there is a marginal risk of severe weather (level 1 out of 5) for northern portions of the Brazos Valley/Piney Woods for Friday. With PW values exceeding the 90th percentile, there is also a marginal risk of excessive rainfall (level 1 out of 4) on Friday as well for portions of the Brazos Valley/Piney Woods. This is all under the assumption that storms can maintain themselves long enough in at least a slightly capped environment...which is why it's a marginal risk. As far as temperatures go, expect another day with high temperatures in the low to mid 80s with low temperatures in the low to mid 70s. This will be another night where we may approach record high minimum temperatures in some spots. Batiste && .LONG TERM... (Saturday through next Wednesday) Issued at 257 PM CDT Thu Apr 25 2024 With a weak surface boundary continuing to sit just to our north (and thereby keeping rainfall out of the area for the time being), the main story of Saturday will be the potential for some of the warmest conditions we've seen across the area in many months. Robust onshore flow will provide both steady WAA and low-level moisture transport, helping to drive a further increase in high temperatures to the mid/upper 80s while dew points sit just above 70. Resultant WBGT values will reach around 80, which is mitigated somewhat by elevated cloud cover and strong winds brought on by a very tight pressure gradient given a deep surface low to the NE. Many locations may in fact reach Wind Advisory criteria during the day on Saturday, with winds reaching around 25 mph with gusts at times reaching in excess of 30 mph. Rainfall chances increase on Sunday as a midlevel low pushes into the Central Plains while the surface boundary drifts back to the south. Scattered showers and storms will become more widespread by the afternoon, and while there remains a limited chance of a stronger storm, severe weather chances remain best well to the north of the area. Associated widespread cloud cover will diminish highs slightly with most values in the low/mid 80s. Overnight lows remain in the lower 70s through the duration of the weekend. The weak boundary will remain stalled over the area through mid- week, with passing shortwaves bringing a chance of showers and storms each day through at least Wednesday. Highs should generally remain in the mid 80s by this time with lows in the lower 70s. Cady && .MARINE... Issued at 257 PM CDT Thu Apr 25 2024 Elevated winds will build further heading into the weekend, with sustained winds increasing from around 20 knots tonight to up to 25- 30 knots on Saturday. As this occurs, seas may reach as high as 10 feet at times, and an extended Small Craft Advisory is likely to be required with conditions offshore remaining poor into the early part of next week. Rainfall chances return by late Sunday, becoming more isolated on Monday. Winds and seas will both diminish heading into the early part of next week, remaining generally out of the southeast. Cady && .HYDROLOGY... Issued at 257 PM CDT Thu Apr 25 2024 Only one River Flood Warning remains in effect along the Trinity River. The Trinity River at Moss Bluff (MBFT2) remains in minor flood stage and is forecast to crest some time today. This site is forecast to remain in minor flood stage through Monday. The Trinity River at Riverside (RVRT2) and at Liberty (LBYT2) will remain in action stage until further notice. Additional rounds of rainfall are expected over the next week or so with the highest totals occuring to the northeast of Southeast Texas. With some of the locally heavy rainfall expected to occur along the Upper Trinity River, the subsequent runoff may lead to an even longer period of action stage to minor river flooding along this basin. You can monitor current and forecast conditions at this weblink: water.weather.gov/ahps2/forecasts.php?wfo=HGX Batiste && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 71 83 72 87 / 10 30 10 10 Houston (IAH) 73 84 73 86 / 0 30 10 0 Galveston (GLS) 72 79 73 81 / 0 20 10 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...Small Craft Should Exercise Caution through Friday evening for GMZ330-335. Small Craft Advisory until 7 PM CDT Friday for GMZ350-355-370- 375. && $$