####018007524#### FXUS65 KRIW 031140 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 540 AM MDT Fri May 3 2024 .KEY MESSAGES... - Snow and rain showers today, ending from West to East. - Saturday looks dry and mild. Snow returns to the west Sunday, with windy and warm conditions East of the Divide. - Cool, blustery and unsettled much of next week. The heaviest precipitation is expected in northern Wyoming. Details past Monday remain uncertain. && .DISCUSSION... Issued at 334 AM MDT Fri May 3 2024 The forecast today will have two prominent words beginning with W. The first is the state we are in Wyoming. The second is the season that seems to last longer than any other here, winter. Winter is reminding us that it is not done yet. Snow is currently ongoing across much of the west, courtesy of a trough and cold front moving into western Wyoming, with a circulation noted over eastern Idaho. As I write this around 2:30 am, areas East of the Divide are mainly dry. There is rather dry air at the surface, this evening's sounding showed it and the tell tale donut hole in the imagery over the radar site is showing the snow is having trouble reaching the ground. Dew point depressions are still rather large, but it should be snowing by the time most people wake up. If you don't like snow, this will be good since the longer it takes to start, the less that can accumulate before the sun comes up. After around 8 or 9 am, the strong May sun should keep roads mainly wet and limit accumulation. Even now, only some of the passes are slick. Reasoning on the timing of the precipitation remains the same, with the steadiest in the morning, then gradually tapering off in the afternoon as the system moves to the east. All showers should end by around 9 pm tonight. Many locations will see some accumulation of the grass, but this will be elevation dependent. For a rough guide, the 1 in 2 chance of an inch or more of snow lies mainly above or below 6000 feet in areas of central Wyoming.Far northern areas will see the least chance of snow. With the clouds and precipitation, temperatures will average below normal. Much of the weekend looks dry and warm, especially East of the Divide. Saturday looks to be the nicest day with high pressure over the area, bringing sunshine, near to somewhat above normal temperatures and mainly light wind. As for Sunday, the approaching, more potent Pacific system appears a bit slower, so POPs and QPF were reduced across the west during Saturday night and Saturday morning. We did maintain a small chance of convection East of the divide late, but this is looking less likely with less than a 1 in 5 chance in any location. Most locations East of the Divide should be dry through sunset with downsloping, southwest flow continuing. This will bring in additional concerns though. One, the potential for strong to potentially high wind. I would put the chance at 1 out of 3 at this point. This will especially be case in areas prone in southwest flow, like Casper, the Green and Rattlesnake Range and possibly Lander. The strongest winds may end up being across southern Wyoming, closer to the jet energy, courtesy of the right front quadrant of an 100 knot jet streak. Another clue is 700 millibar winds, with some 50 to even 60 knot barbs showing up in southern Wyoming. There could also be elevated fire weather, although increasing dew points may mitigate this. Temperatures will peak Sunday East of the Divide, with mainly locations rising into the 70s. Heavier precipitation will move into the west in the afternoon and especially in the evening as the low moves toward and area and the best lift from the left front quadrant of the aforementioned jet streak approaches the area. Snow levels look to remain above 7000 feet through the day as 700 millibar temperatures hold at minus 3 or warmer. Colder air will move in at night though and drop snow levels to the floor across the west. Favorable, moist westerly flow will keep snow going in the mountains into Monday as well. There is greater than a 3 in 4 chance of over a foot of snow across the Tetons and over 6 inches across the remainder of the western mountains. Some highlights will likely be needed over this period. Meanwhile, in areas East of the Divide, rain and snow will overspread the area. With the expected track of the low to be across central Wyoming, the main impacts would be in northern Wyoming. This would especially be the case in Johnson County and the Bighorns, where upslope will be favorable and wrap around precipitation may continue as the low moves slowly to the east. There is more uncertainty for amounts here with more model differences. It also looks warmer here, with 700 millibar temperatures falling to around minus 5 or so. This would keep snow levels around 6000 feet or higher, keeping the populated areas mainly rain. Several inches of snow will be possible in the Bighorns though, with a greater than 1 in 2 chance of advisory level amounts. Reasoning remains the same through much of the week, as a blocking ridge sets up across the Great Lakes and the upper level low can only move slowly away and long wave troughing hangs over the Rockies. No major storms are expected. The main concern will be wrap around precipitation and if it can move into northern Wyoming. Uncertainty is high on details here through. A tight pressure gradient will also stay across the area, keeping gusty to strong wind going across many areas possibly through Wednesday before finally weakening. So, to sum up the extended, we have high confidence (greater than 4 in 5) of a cool, blustery and damp pattern through much of the next workweek. Confidence on the details past Monday remains very low, however. && .AVIATION /12Z TAFS THROUGH 12Z SATURDAY/... Issued at 540 AM MDT Fri May 3 2024 Widespread snow showers will continue and associated IFR to occasional LIFR conditions will persist across most terminals this morning through at least 16Z. Snow showers will end from west to east through the morning, so expect to see KBPI/KJAC/KPNA terminals see improvements between 14Z and 16Z with mostly clear skies prevailing by mid afternoon. Hi Res models continue to indicate that a snow band or series of bands will pass through KRKS between 12Z and 16Z this morning, but lack of radar coverage near the terminal has made it difficult to pinpoint exact timing of that band. East of the Divide, snow may changeover to rain late in the morning before ending west to east between 16Z and 20Z. By 20Z, all terminals are expected to see prevailing VFR conditions. Winds will be gusty with many locations seeing northerly or northeasterly winds of 10 to 15kts with gusts 20 to 25kts at times. Winds will diminish quickly towards sunset. Light winds and mostly clear skies will prevail across the region after 03Z. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on icing and turbulence forecasts. && .RIW WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 3 PM MDT this afternoon for WYZ015. && $$ DISCUSSION...Hattings AVIATION...Hensley ####018007646#### FXUS63 KMQT 031141 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 741 AM EDT Fri May 3 2024 .KEY MESSAGES... - Active pattern continues through next week as a series of low pressure systems track across the U.S. and affect Upper MI. Above normal precipitation expected, including chance of thunderstorms at times. - Mostly above normal temperatures expected, generally 5 to 10 degrees above normal on the majority of days thru the middle of next week. && .SHORT TERM /TODAY/... Issued at 504 AM EDT Fri May 3 2024 Current water vapory imagery/RAP analysis highlight a well-defined shortwave rotating over the MN/Canada border with its associated occluded front already well into Upper Michigan. As expected, showers have quickly tapered off with frontal passage with the only activity on latest radar mosaic concentrated over the easternmost portions of the UP. And, even these should taper off by mid- morning. So far, convective activity has been non-existent, but still cannot rule out a few rumbles of thunder over the far eastern counties after sunrise. Most of the forecast area will be sunny this morning as forecast soundings trend toward a dry column. The exception will be the eastern third of the UP where it will take a bit longer for the moisture/cloud cover to clear out. Gusty southwest winds in the 20 to 30 mph range, especially across the western UP will contribute to rapidly falling dew points and temperatures climbing into the upper 60s/low 70s (inland). Recent rainfall will, however, mitigate today's fire weather threat. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... Issued at 542 AM EDT Fri May 3 2024 Overall, the first half of the extended period (tonight through Monday night) is mostly dry and sunny as high pressure tracks across the area with just a brief chance for rain showers on Saturday. Elevated fire wx conditions may occur each day Sat - Mon, but are more likely on Sunday and Monday when sunny skies help us dry out. On the other hand, we return to a pattern with frequent rain chances for the Tuesday thru Friday time frame as a broad area of low pressure spins across the region. There are early signals for a prolonged stretch of drier weather starting the weekend of May 11/12, but temperatures appear to average near normal at this time. Starting with tonight, weak surface ridging to our east results in light southerly flow with upper level cloudiness spreading across the western UP overnight. Mostly clear skies across the east should allow for good radiational cooling into the upper 30s away from downsloping along the Lake Superior shoreline. The next weather maker approaches Saturday morning and most guidance suggests a weak but deepening surface low. Rain chances spread across the western UP during the morning which keeps high temps cooler (around 60F) compared to the central and especially the east where highs approaching 70F are forecast. Warmer temps/deeper mixing across the east within the dry pre-frontal air mass suggests potential for locally elevated fire wx conditions. It's worth noting that both NAM and GFS soundings show single digit RH values in the mid-level dry layer that we'll be mixing into. Increasing cloud cover should limit mixing potential, but conditions appear to be trending more volatile across the east ahead of Saturday's rain chances. The cool front and associated rain chances spread across the central and eastern UP during the afternoon and evening, respectively. The NAM-3km even delays precip at Newberry until around midnight or 3-5 hours later than the GFS. HREF ensemble mean MUCAPE remains less than 100 J/kg, but HRRR simulated radar indicates an increasingly convective pattern as showers track east across the area. Overall, the forecast may still exaggerate the rain potential with this system since model soundings only show a 3-6 hour window of rain chances at any one location. Limited instability and duration indicate light amounts are most likely. Dry high pressure settles across the area on Sunday allowing sunny skies to spread across the area during the morning hours. In fact, CAMs suggest potential for fog resulting from moisture lingering in a boundary layer inversion beneath clearing mid/upper level clouds. A more straight-forward radiation fog setup could materialize Sunday night under high pressure, clear skies and light winds. Otherwise, fire weather is the primary concern for the Sunday-Tuesday period. Sunday and Monday are both likely to see min RH dipping below 30% across the interior, but light winds temper the fire wx threat. Stronger winds are expected on Tuesday and if the dry air mass lingers a bit longer then Tuesday likely represents a more volatile combination of low RH and winds. However, that possibility depends on rain chances being delayed until late in the day which current model blends do not indicate. Late week rain chances are associated with a deep closed low developing across the Northern Plains late on Monday that slowly spins eastward over the subsequent week. Moderate rainfall and embedded thunderstorms are again possible with the warm front passage Tuesday/Wednesday followed by spottier showers Thursday/Friday. A cold core upper low suggests a large diurnal component to the late week shower activity. && .AVIATION /12Z TAFS THROUGH 12Z SATURDAY/... Issued at 739 AM EDT Fri May 3 2024 VFR conditions have already returned to IWD this morning where there has been clearing in the wake of an occluded front. CMX and SAW will be a tad slower to clear out though, but trended toward a mid-morning return to VFR at both sites. This may be a bit too optimistic though, and a late morning VFR return cannot be ruled out. Once VFR returns, it will prevail through the remainder of the TAF period. Meanwhile, strong west-southwest winds will increase through the morning at IWD and CMX with gusts to 26 kts through this evening. && .MARINE... Issued at 542 AM EDT Fri May 3 2024 Light winds, mainly out of the south-southeast are currently being observed across Lake Superior and winds are expected increase while veering southwesterly today. While gusts up to 25kt are expected over western Lake Superior this afternoon, winds diminish to less than 20kt tonight. Expect winds mostly below 20kts across Lake Superior this weekend, but northwesterly winds increase to around 20 knots Saturday night behind a cold front before becoming light again on Sunday. High pressure that arrives over the Upper Great Lakes late this weekend shifts eastward on Mon while a deep low pressure emerges over the western Dakotas. This will result in increasing easterly winds late on Mon into Tue when gusts up to 30kts are expected. Patches of locally dense fog are occuring over western Lake Superior this morning, which is expected to push mainly into Canadian waters as south/southwesterly winds increase today. If fog does not clear off of the lake today then additional rain chances on Saturday may result in increasing fog coverage. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...TDUD LONG TERM...EK AVIATION...TDUD MARINE...EK ####018004417#### FXUS64 KBMX 031141 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 641 AM CDT Fri May 3 2024 ...New AVIATION... .SHORT TERM... (Today through Saturday) Issued at 242 AM CDT FRI MAY 3 2024 A rather messy upper flow pattern the next few days with several waves of showers and embedded thunderstorms to track eastward across the northern portions of Central Alabama. Despite decent coverage of rain each day across the north, rainfall amounts will be rather modest with most areas receiving less than one-half inch of total rainfall. Highs in the mid to upper 80s expected across areas south of I-20, while cloud cover and rain will keep temperatures slightly cooler north of I-20, with highs in the lower to middle 80s. 58/rose && .LONG TERM... (Saturday night through next Thursday) Issued at 253 AM CDT FRI MAY 3 2024 Weak quasi-zonal flow aloft continues Sunday, with yet another convectively enhanced shortwave/MCV moving in from the Plains during the late afternoon and evening hours. PWATs around 1.8 inches will be favorable for scattered to numerous showers and storms developing with daytime heating, highest chances north. The shortwave appears a touch slower than previously forecast and have raised PoPs Sunday evening. Shortwave ridging in advance of the shortwave trough should allow temperatures to warm into the mid to upper 80s ahead of convection. A deep trough will eject across the Central and Northern Plains Monday with ridging building ahead of it. The prior weak shortwave may still be close enough to some of the northeastern counties to enhance diurnal convection there. The deep trough remains across the north-central CONUS on Tuesday as ridging builds over the Southeast CONUS. Strengthening low-level southwesterly flow will cause efficient mixing and warming temperatures/lowering dew points especially across the southeast half of the area, suppressing convection. But moisture pooling ahead of a stalled frontal boundary may remain sufficient for isolated to scattered convection in the northwest counties. Wednesday and Thursday a trough with a strong positive tilt will extend from the Great Lakes to the Four Corners while subtropical ridging strengthens over the Gulf. The tightening mid-level height gradient between these two features will result in strengthening WSW flow aloft. A quasi-stationary frontal boundary will reside across the Mid-South with several waves of low pressure riding along it. A strong EML will result in a very unstable air mass south of the front with strong deep layer shear as well. An early spring heatwave with near record highs looks likely across the southern counties. Will have to watch any convective disturbances skirting near the northern counties along the northern fringes of the warmer 700mb temperatures given a conditionally favorable environment for severe storms. 32/Davis && .AVIATION... (12Z TAFS) Issued at 627 AM CDT FRI MAY 3 2024 A zonal upper flow pattern across the southern United States with weak ridging along the Gulf Coast will result in scattered to numerous showers with embedded tstms impacting mainly north Alabama thru the period. Cigs will stay mostly aoa 5000 ft agl with lcl vsbys blo 3 miles in heavy showers. MVFR/IFR cigs will development after 09Z. 58/rose && .FIRE WEATHER... Moisture increases today. RH values will fall into the mid to upper 30s in the southeast, with higher values elsewhere. Scattered showers/storms return for Friday afternoon in the north and west and spread east through Saturday. RH values range from 40 to 60 percent Saturday afternoon, lowest values south. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 82 63 82 61 / 40 60 60 30 Anniston 83 65 83 63 / 40 40 60 30 Birmingham 82 66 84 65 / 30 50 40 30 Tuscaloosa 83 67 85 65 / 40 60 40 20 Calera 82 66 84 65 / 30 50 40 20 Auburn 84 67 84 66 / 20 30 40 30 Montgomery 86 67 88 66 / 20 20 30 20 Troy 86 66 88 64 / 20 20 30 30 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...58 LONG TERM....32 AVIATION...58/rose ####018005999#### FXUS65 KCYS 031143 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 543 AM MDT Fri May 3 2024 .KEY MESSAGES... - A cold front will move through the region today with another round of shower activity in the mountains and isolated thunderstorms over the southern Nebraska Panhandle. Snow levels will remain above 6500 feet. - Mainly dry and warmer conditions are anticipated for the weekend. - Breezy to windy, and cooler weather expected for Monday through Wednesday, with isolated to scattered late day showers and thunderstorms. && .SHORT TERM /THROUGH SATURDAY NIGHT/... Issued at 305 AM MDT Fri May 3 2024 Today...A progressive and positively tilted shortwave trough aloft moves from western Wyoming this morning to central Wyoming by mid afternoon and to eastern Wyoming by late afternoon. Its associated fairly strong cold front moves quickly across our counties by late afternoon with winds turning to the north and increasing. With ample low and mid level moisture, and decent frontal lift along with dynamic lift supported by 500-300 mb and 700-500 mb quasigeostrophic lift, we anticipate scattered to numerous showers spreading from our western counties this morning to our southern and eastern counties this afternoon, along with isolated thunderstorms mainly east of I- 25. Snow will fall over the higher elevations of the Snowy and Sierra Madre Ranges with amounts from 4 to 7 inches, however with the snow falling during the daylight hours, there will likely be some melting and compacting of the snow, thus no advisory issuance seems necessary. With the strength of the cold front and the blustery north winds, it will feel rather chilly for early May. Tonight...Precipitation will end quickly this evening as the shortwave trough aloft moves off to our east. Looks like a cold overnight as surface high pressure builds southward across eastern Wyoming and western Nebraska and skies become clear. Saturday...Transitory shortwave ridging aloft will build overhead and with plenty of sunshine and 700 mb temperatures near 2 Celsius, maximum temperatures will reach the mid 50s to mid 60s, with southeast low level winds limiting the warmup. Saturday night...Decent moderation in temperatures will occur as southwest flow aloft strengthens ahead of the approaching trough aloft over the Great Basin states, inducing increasing south winds and a thermal ridge over our counties, with low temperatures from the mid 30s to lower 40s. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Issued at 305 AM MDT Fri May 3 2024 Sunday will be the warmest day of the weekend as a shortwave ridge axis moves just to the east ahead of a large scale upper level low moving towards the central Rockies. 700mb temps will warm near 6-10C with afternoon temperatures reaching the upper-60s and 70s ahead of increasing cloud cover with the approaching upper level low. Areas west of the Laramie Range, especially southwest Carbon Co and the Sierra Madres will begin to see increasing moisture Sunday night leading to accumulating snowfall above 7500 ft elevation. Based on the upper level low track, the majority of wrap around moisture will most likely develop farther north and east. However, lee troughing across much of the WY Front Range will lead to increasing mslp gradients and the potential for strong westerly winds across our area starting Monday. Latest NBM probabilities of 55+ mph wind gusts are quite high (>80%) for most wind-prone areas across southeast WY with areas covered by 50% probabilities expanding outside of wind-prone locations onto adjacent foothills and plains. Additionally, in-house guidance has been showing high probabilities (60-80%) for high winds, however there still remains run-to-run uncertainty with the duration and timing of strongest winds. This should clear up as models continue to get a better idea on the low track and evolution. Right now, the timing for the strongest winds appears to be Monday afternoon with 700mb flow climbing over 60 kt across southeast WY and 850mb (700mb) CAG-CPR height gradients exceed 70m (60m). Latest cluster analysis shows ~45% of EC membership favors a slightly farther south track that will lean towards stronger wind speeds aloft over our area. Overall, there remains strong ensemble support for high winds early next week with latest NAEFS and EC showing over climatological 99th percentile 700mb winds. This upper level low looks to stall out across the central CONUS leaving southeast WY and western NE under a general troughing pattern through the remainder of the week. This will lead to below average temperatures for early May with additional chances for light precipitation. && .AVIATION /12Z TAFS THROUGH 12Z SATURDAY/... Issued at 536 AM MDT Fri May 3 2024 SCT-BKN mid-level clouds persist early this morning across the region with VFR conditions as rain/snow showers approach from the west per latest satellite and radar imagery. These showers will likely reach KRWL over the next few hours with lowering ceilings and visibilities through the morning. Additional shower development is expected along a frontal boundary that will be positioned from KLAR through KCDR by midday with gusty northerly winds developing as the front continues to move to the south. Cannot rule out a few rumbles of thunder near KSNY which could see a stronger storm develop early this afternoon before the frontal boundary clears the area. Skies will begin to clear early this evening as precipitation continues to move off towards the east. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...RUBIN LONG TERM...MB AVIATION...MB ####018004801#### FXUS64 KBRO 031143 AAA AFDBRO Area Forecast Discussion...UPDATED National Weather Service Brownsville TX 643 AM CDT Fri May 3 2024 ...New AVIATION... .SHORT TERM... (Today through Saturday) Issued at 357 AM CDT Fri May 3 2024 A 500 mb disturbance will approach the western portion of CWA this afternoon. At the surface, the southern extension of the Texas dryline will likely lie just to the west of the area today, extending south into Mexico along the Sierra Madre Oriental range. The combination of a very moist low-level airmass, daytime heating and mid to upper level energy will support the develop of convection over neighboring Mexico. Forecast soundings from along the Rio Grande River suggest SBCAPE values of 2500-4000 J/kg late this afternoon. The isolated to scattered showers and thunderstorms may drift into Zapata, Starr, and Jim Hogg counties later this afternoon and evening. SPC has placed the County Warning Area in a general thunderstorm risk area, generally along and east of US 281/I-69C, with the portions of the Rio Grand Plains and the Upper Valley in a marginal thunderstorm risk for today and tonight. Large hail and locally damaging wind gusts will be the main threats. There is a low chance that these stronger supercells will move into the western portions of the CWA this afternoon and evening. SPC has all of Deep South Texas outlined in a general thunderstorm risk for Saturday. Otherwise, increasing low level moisture and light winds this morning may support patchy light fog, mainly across the Northern Ranchlands and near/over marine areas. Additionally, above normal temperatures will continue through the short-term with highs generally ranging from the low to mid 90s, except for the 80s near the coast, today and Saturday. Overnight temperatures will be warm with lows in the mid to upper 70s, which is a blend of the NBM/CONSShort. Southeast winds will remain moderate to breezy. Elevated seas will result in a Moderate Risk of rip currents at the local beaches today through Saturday. && .LONG TERM... (Saturday Night through Thursday) Issued at 357 AM CDT Fri May 3 2024 Increasing and prolonged heat will be the main concern during this portion of the total forecast. Steadily rising daytime highs will occur throughout the period, with well above normal values likely in the Tuesday through Thursday time frame. Temperatures will near established HEAT ADVISORY criteria on Tuesday, and may reach or surpass the threshold for Wednesday and Thursday as a dryline nudges into the BRO CWFA from the west. Additionally, an enhanced pressure gradient will produce a breezy to windy onshore flow, providing some measure of relief from the heat, especially in shaded areas. However, the strength of the wind will not near or exceed established WIND ADVISORY criteria. && .AVIATION... (12Z TAFS) Issued at 636 AM CDT Fri May 3 2024 Light southeast winds and widespread IFR/MVFR conditions prevail across Deep South Texas early this morning. The increase in the low level moisture and light winds have allowed for patchy fog to develop across portions of the region this morning. MVFR ceilings are expected to linger through mid to late morning. VFR conditions are expected to return this afternoon, especially at MFE. MVFR ceilings are expected to develop again later this evening into tonight. && .MARINE... (Today through Saturday) Issued at 357 AM CDT Fri May 3 2024 Moderate to fresh southeast winds and moderate to sometimes marginally high seas will prevail along the lower Texas Coast through the period. Small Craft Exercise Caution conditions will be likely for portions or all of the lower Texas coastal waters through Saturday. (Saturday Night through Thursday) An enhanced pressure gradient will exist over the western Gulf of Mexico throughout the period. Breezy to strong winds and moderate to rough seas will prevail along the Lower Texas Coast, with both Small Craft Exercise Caution and Small Craft Advisory likely to be needed. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 90 77 88 76 / 20 10 0 0 HARLINGEN 91 75 91 74 / 20 10 0 0 MCALLEN 93 77 93 77 / 20 10 0 10 RIO GRANDE CITY 93 77 94 76 / 20 10 10 10 SOUTH PADRE ISLAND 82 77 81 76 / 20 10 0 0 BAYVIEW/PORT ISABEL 87 76 86 74 / 20 10 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ SHORT TERM...63-KC LONG TERM....66-Tomaselli AVIATION...63-KC ####018005451#### FXUS63 KGID 031143 AFDGID Area Forecast Discussion National Weather Service Hastings NE 643 AM CDT Fri May 3 2024 .KEY MESSAGES... - Rain and storm chances increase (up to 90 to 100%) this evening and overnight. Some of these storms may be severe with damaging winds, hail up to the size of half dollars, and localized flooding. - Another good chance of rain and thunderstorms (up to near 90%) Monday into Monday night with severe storms possible. - High temperatures will be in the 60s and 70s. Lows will be in the 30s and 40s through the weekend, then in the 40s and 50s next week. && .DISCUSSION... Issued at 252 AM CDT Fri May 3 2024 Today and tonight... Aloft (at 500 mb), a broad upper trough extends across the northern Plains and further west dives further south across the western CONUS. At the surface, a developing trough extends across the northern Plains toward the Rockies with a surface low over southeastern Utah, with a surface high over the central Plains. Today, the surface high will move to the east while the surface low strengthens and moves east toward eastern CO by this evening and into the Hastings forecast area by midnight, dragging a cold front behind it. Meanwhile, the deeper upper trough will move east over the central Plains this evening and tonight with a pronounced shortwave moving over the forecast area this evening. High temperatures today will be in the 70s. The latest CAM guidance shows showers and thunderstorms developing over western NE this afternoon, then developing into a line of storms moving east across the area this evening and overnight. Showers and thunderstorms can be expected across the area from around 7PM to 5-6 AM CDT, with the best chance for severe weather between around 8PM and 2AM. The main threats with this system will be large hail to around the size of half dollars (~1.25" diameter) and damaging wind gusts in excess of 60 mph (this will likely be the main concern). While an isolated tornado cannot be ruled out, we are expecting many of the storms to be elevated and with low level moisture struggling to get this far north, the chance for tornadoes remains low. Even after the thunderstorms move through, expect showers into the morning hours Saturday with gusts of 25-35 mph out of the north behind the front. Lows Saturday morning will range from the mid 30s north and west to the mid- to upper 40s south and east. This weekend... Showers and thunderstorms will move off to the east-southeast Saturday morning. Surface high pressure will move over the region Saturday while an upper ridge moves over the area late Saturday into Sunday. Saturday will be dry after the lingering showers/storms move out early morning with highs in the 60s and lows in the upper 30s to mid 40s. Sunday will remain dry as well for many areas, but an upper level trough across the southern Plains may impact the region enough to bring a few showers/storms to the area Sunday evening and into Monday morning. Monday... This will be the next chance for severe thunderstorms, assuming showers and storms earlier in the morning do not make the environment unfavorable for this. That being said, a deep upper level trough will extend from western Canada into the central and southern Plains, while a surface front moves across the Plains Monday and Monday night. With high temperatures in the 70s, there is a high chance (around 80%) of showers and thunderstorms developing Monday afternoon and evening. Latest model guidance indicates that there will be enough instability and shear to support severe thunderstorms during this time, with storms anticipated to move out of the area overnight Monday night. Next Tuesday through next Thursday... High temperatures will be in the 60s and 70s with periodic low chances (15-30%) of showers and thunderstorms through the period, mainly Thursday afternoon and evening. && .AVIATION /12Z TAFS THROUGH 12Z SATURDAY/... Issued at 632 AM CDT Fri May 3 2024 Winds: South winds up to 10 kts are expected to start the period this morning. There are a few showers west of the TAF sites this morning but confidence of impacts at the terminals too low to include in the TAFs. South winds will increase going into this afternoon with gusts of 20-25 kts expected. Winds will become southeasterly this evening with gusts to 25 kts, then northerly tonight as a front moves through with gusts of around 30 kts. Northerly winds will prevail through the end of the TAF period with gusts up to 25 kts behind the front. Precipitation: Showers and thunderstorms are expected to move across the TAF sites this evening and overnight as a front moves through. Expect at least -RA with VCTS from approximately 04/02Z until 04/09Z, with periods of TSRA within that window, most likely in the 04/03 to 04/06 timeframe. Flight Category: VFR until this evening when -RA and VCTS move in. IFR/MVFR ceilings are expected this evening through the end of the TAF period. LLWS: A brief window of LLWS is possible just along and behind the front overnight. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ DISCUSSION... AVIATION...Hickford ####018003982#### FXUS64 KOUN 031143 AFDOUN Area Forecast Discussion National Weather Service Norman OK 643 AM CDT Fri May 3 2024 ...New AVIATION... .SHORT TERM... (Today and tonight) Issued at 206 AM CDT Fri May 3 2024 Scattered showers/storms will continue into the morning hours with the highest chances in east central and southeast parts of the fa. The severe potential with this activity has diminished but still could get some gusty winds out of the stronger storms. Heavy rain/localized flooding will also be possible, especially in those areas that have already received several inches of rain and where storms train. The frontal boundary that moved across parts of the area Thursday will lift back north later today with moisture spreading back northward. Thunderstorms are expected to develop west of the area later today and move into the fa this evening/overnight. Meanwhile, another cold front is expected to begin to move into the fa overnight/early Saturday which would also be a focus for shower/storm development. Severe storms will be possible starting this evening with damaging wind and hail possible. Highs today are expected to be in the 70s to low 80s with overnight lows ranging from the mid 50s in the NW to the mid 60s in the SE. && .LONG TERM... (Saturday through Thursday) Issued at 206 AM CDT Fri May 3 2024 With the frontal boundary over the fa and potentially a shortwave moving across the region, showers and thunderstorms will remain possible Saturday into Sunday. Severe storms will be possible again Saturday evening and overnight with damaging wind and hail. However, what might be a bigger concern this weekend is the potential for more widespread heavy rain with heaviest amounts expected across the southern half or so of the area. With the recent heavy rainfall that has already occurred, this heavy rain could lead to additional flash flooding/river flooding in several areas. For Monday, models show an upper trough approaching and moving into the Plains. At the sfc, a dryline develops and moves into the area. Thunderstorms will be possible once again with severe storms possible. The potential for severe weather could be greater on Monday compared to the next few days due to the added upper air support. There are some uncertainties since what happens over the weekend could affect the airmass over the region but with the upper support and dryline, thunderstorms/severe storms are possible Monday. After Monday it looks like there could be a period of quieter weather for at least the middle of next week with highs in the 80s. && .AVIATION... (12Z TAFS) Issued at 619 AM CDT Fri May 3 2024 A very low stratus deck will keep most of our terminals from LIFR to MVFR conditions through 16-21Z. Dense advection fog coming up from north Texas will also be reducing visibility's for a few hours at terminal KSPS. All terminals will have returned to VFR conditions after 21Z although may return to MVFR to IFR conditions after 06Z due to lowering ceilings. Thunderstorms may develop after 00Z across northern Texas which could affect all terminal generally west of I-35, although probabilities are low so PROB30 groups are in the potentially affected terminals. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 77 63 77 60 / 20 40 90 70 Hobart OK 78 60 76 58 / 30 50 80 80 Wichita Falls TX 80 62 78 61 / 30 40 80 80 Gage OK 79 54 68 51 / 20 70 50 60 Ponca City OK 78 61 73 57 / 10 60 80 60 Durant OK 82 65 79 64 / 30 30 70 70 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...Flood Watch until 7 AM CDT this morning for OKZ041>043-046>048- 050>052. TX...None. && $$ SHORT TERM...68 LONG TERM....25 AVIATION...68