Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/28/19

See below for an aviation forecast discussion for the 00Z TAFs.

&& .SHORT TERM...(This Evening through Sunday Afternoon) Issued at 313 PM CDT Sat Jul 27 2019 High pressure currently over the area will get pushed eastward this evening as a low pressure system and associated frontal boundary approach. Showers and thunderstorms are beginning to develop over the western part of the state this afternoon. This area of precipitation will become more widespread this evening, then will track eastward tonight into the day Sunday. Cannot rule out a strong storm or two, but instability and shear are forecast to be pretty minimal. Biggest threat appears to the potential for heavy rain as PWATs increase into the 1.5 to 2 inch range tonight and remain high into Sunday. 3 hour flash flood guidance is over 2 inches across almost the entire CWA, so most areas should be able to handle one to two inches of rain, but will have to monitor tonight should there be higher amounts. This area of precipitation looks to exit the CWA sometime Sunday afternoon, but increasing instability across the central part of the state could make for a few additional thunderstorms there Sunday afternoon before quiet conditions return Sunday night. Low temperatures tonight will be in the 60s. Highs on Sunday will rebound back into the 80s, except across the far eastern part of the CWA where precipitation and cloud cover will linger the longest, keeping temperatures in the 70s. Lows Sunday night will range from the mid 50s west to the lower 60s east. .LONG TERM...(Sunday Evening through Saturday) Issued at 313 PM CDT Sat Jul 27 2019 The long term starts on Monday with northwest flow aloft and surface high pressure over the Northern Plains. The surface high shifts east Monday night through Tuesday night, allowing a weak LLJ and instability showers and thunderstorms to development. Toward the end of the work week, ridging aloft, along with southerly flow will bring heat and humidity into the region. Dew point temperatures will range in the low 50s and 60s early in the week. By Friday, dew points should reach the mid to upper 60s. The humid airmass, along with upper shortwaves will bring the potential for isolated to scattered showers and thunderstorms Thursday night through Saturday. && .AVIATION...(For the 00Z TAFS through 00Z Sunday Evening) Issued at 650 PM CDT Sat Jul 27 2019 VFR conditions will prevail this afternoon and evening. Showers and thunderstorms will spread from west to east across the area overnight and into Sunday morning. Periods of sub-VFR cigs and vsbys in heavy rain are possible with the thunderstorms tonight and Sunday. After 12Z Sunday, MVFR cigs may temporarily develop over KPIR/KMBG before clearing off/VFR in the afternoon. But look for MVFR cigs to become the prevailing condition at KABR/KATY after 12Z Sunday and persist for much of the day. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...Dorn SHORT TERM...Parkin LONG TERM...SD AVIATION...Dorn
National Weather Service Albany NY
1018 PM EDT Sat Jul 27 2019 .SYNOPSIS... Very warm temperatures will continue this weekend into early next week. Humidity will increase Sunday, with humid conditions lingering into midweek. Periodic showers and thunderstorms will be possible, mainly during the afternoon and evening hours. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... As of 1015 PM EDT, small cluster of showers and embedded thunderstorms continues to track east across Warren County. Latest trends overall have been weakening, however still can not rule out some brief wind gusts to 30-40 mph and heavy rain over the next 1-2 hours across the Lake George region into central/northern Washington County. Elsewhere, some mid level cloud patches continue to drift east across the Catskills and northern mid Hudson Valley region. Little in the way of showers elsewhere, although can not completely rule out an isolated shower as additional shortwave energy moves eastward overnight. Previous discussions follow... As of 715 PM EDT, isolated cluster of thunderstorms will grazing extreme NE Litchfield County now mainly east of the southern part of the Barkhamsted Reservoir. There has been a tendency for the northwest end of this cluster to backbuild, so will continue to closely monitor trends. Very heavy rainfall and some small hail is likely with the highest cores, in addition to wind gusts of 40+ mph. Elsewhere, watching an area of agitated Cumulus clouds across the western Mohawk Valley, with some embedded showers, translating northeast. This seems to be located just ahead of another weaker shortwave, as depicted at H500 in the latest RAP 13. Will have to monitor trends with this area as well, with chances for showers and thunderstorms to develop from this area across the Mohawk Valley, SW Adirondacks, and perhaps extending as far east as the Lake George/Saratoga region through midnight. Elsewhere, just patches of mid level clouds. Will keep isolated shower/thunderstorm mention for all other areas through this evening in case additional activity develops ahead of aforementioned mid level impulse. Previous discussion follows... As of 310 pm, water vapor imagery shows an upper trough axis centered roughly over western New England. A few isolated thunderstorms have developed in association with this trough in an environment of around 1500 J/kg SBCAPE without much capping. These have mainly been over the higher terrain and fairly weak, although one updraft earlier became robust and resulted in some wind damage near Saugerties. These storms are of the pulse variety without much wind in the troposphere, so they are generally short lived. Radar trends over the last hour have been weakening, and would expect this to continue as the trough shifts east of the area this afternoon/evening. Any remaining showers or storms should quickly dissipate tonight with the loss of diurnal heating. Midlevel flow becomes zonal ahead of a very weak trough as the weak disturbance from this afternoon shifts east. A light southerly gradient will exist as the surface high shifts east as well, so overnight lows are expected to be a bit milder than last night. Despite the southerly flow, some patchy fog is possible once again in favored areas that decouple. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... The aforementioned weak trough, which is currently (as of early Saturday afternoon) generating a few areas of showers and thunderstorms over parts of Michigan and Ontario, will continue to shift eastward through the region Sunday. This trough will likely be accompanied by one or more surface wind shift boundaries/confluence zones. Although neither of these forcing mechanisms will be very strong, they may be enough to generate a band of showers and isolated thunderstorms approaching our far northwestern zones (southern Adirondacks) by Sunday morning. Downstream, at least partial sunshine along with dewpoints in the upper 60s will help to generate SBCAPE in the 1-2 kJ/kg range despite modest midlevel lapse rates. Current expectation is for continuation of the morning convective activity and/or redevelopment in concert with the aforementioned forcing mechanisms. Convection is expected to spread southeast through the afternoon and evening, becoming scattered in coverage except for parts of the mid-Hudson Valley and Litchfield Hills where is will be more isolated. Best coverage appears to be in the western Mohawk/Schoharie Valleys. Deep-layer shear will be weak at less than 20 kt which should preclude much of a severe weather threat. However, there is slightly stronger flow around 30 kt at 700 mb, and forecast soundings suggest fairly steep low-level lapse rates, so cannot rule out an isolated strong wind gust or two. The storms should be fairly progressive and PWAT will not be too extreme at around 1.50-1.75 inches which should make the flash flooding threat quite low, but as always locally heavy downpours are possible. Prior to the possible rainfall, heat indices are expected to reach the lower 90s in the Hudson Valley. We may continue to see some isolated showers and thunderstorms for the first part of Sunday night as the weak trough remains in the vicinity. Otherwise, it should continue to be quite mild and humid as there will not be a real airmass change. On Monday, midlevel heights will rise a bit in the wake of the weak trough, and H850 temps will increase a couple degrees into the upper teens. This will likely be the hottest and most humid day of the period (along with Tuesday) with heat indices in the mid-90s in the valleys. There will be plenty of CAPE around but little in the way of forcing for ascent. Actually there may be some capping/subsidence with the height rises, so any thunderstorms are expected to remain isolated to widely scattered. Very mild and muggy Monday night. This airmass will remain in place Tuesday ahead of a broad trough approaching from the west. A band of showers and thunderstorms associated with the leading edge of the height falls is likely to work into areas north and west of the Capital District during the afternoon. There is uncertainty with regard to how far east this forcing gets as the midlevel ridge may be tough to dislodge, so have only chance PoPs for much of the area. If the rainfall does not speed up, we are in for another hot and humid day with heat indices as high as the mid 90s again. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... On Tuesday night into Wednesday, an approaching upper level shortwave and associated surface frontal boundary will bring some showers and thunderstorms to the region, with the greatest coverage likely just ahead of the front during peak heating on Wednesday afternoon. It will be fairly warm and muggy, with dewpoints well into the 60s and high temps reaching into the 80s. With the humid air mass in place, any thunderstorm will be capable of producing heavy rainfall. Behind the boundary, slightly less humid air will move into the region for Thursday and Friday, with surface high pressure building into the area from southern Canada. However, the frontal boundary looks to stall just south of the region, so a few isolated showers cannot be ruled out for far southern areas for Thursday into Friday. Sky cover will vary from mostly clear across northern areas to partly to mostly cloudy across the Catskills, Mid Hudson Valley and NW CT. Temps look fairly seasonable, with highs in the mid 70s to mid 80s and lows in the mid 50s to mid 60s. Fairly quiet weather looks to continue into Saturday, but some guidance does suggest another weak shortwave may approach at some point over the weekend. Will keep POPs at slight chc or below with temps continued close to normal. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... An upper level disturbance will move east of the TAF sites overnight. A stronger upper level disturbance will then move across Sunday afternoon. Mainly VFR conditions through early this evening. Will have to watch for isolated showers/thunderstorms, which should remain N/W of KGFL and KALB this evening. Patchy ground fog will likely develop after 05Z/Sun at KGFL, and possibly KPSF after 08Z/Sun. Periods of MVFR/IFR will be possible, with some brief LIFR possible at KGFL, especially between 07Z-10Z/Sun. After any patchy fog/low clouds lift between 10Z-12Z/Sun, expect VFR conditions, until scattered thunderstorms develop in the afternoon. Have included some Prob 30 groups in the TAFs to account for this activity, which may form into clusters or small line segments with embedded IFR conditions. Winds will be light from the south tonight at less than 5 KT, and south to southwest at 5-10 KT late Sunday morning into the afternoon. Winds will be much stronger, and variable in direction in and near any thunderstorms. Outlook... Sunday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Monday: Low Operational Impact. Slight Chance of SHRA...TSRA. Monday Night: No Operational Impact. NO SIG WX. Tuesday: Moderate Operational Impact. Chance of SHRA...TSRA. Tuesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Wednesday: Moderate Operational Impact. Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Low Operational Impact. Slight Chance of SHRA. && .FIRE WEATHER... Very warm temperatures will continue this weekend into early next week. Humidity will increase Sunday, with humid conditions lingering into midweek. Minimum RH values will be mainly in the 40 to 60 percent range. Periodic showers and thunderstorms will be possible, mainly during the afternoon and evening hours. Winds will remain rather light, though slightly stronger from the southwest at times Sunday. && .HYDROLOGY... Scattered showers and thunderstorms are expected Sunday, especially during the afternoon and evening. The storms are expected to be progressive enough to preclude a flash flooding threat, though locally heavy rainfall is possible. Any storms will be mainly isolated to widely scattered on Monday. Scattered to numerous thunderstorms are expected Tuesday and Wednesday which could result in locally heavy downpours, but widespread hydrologic issues are not expected at this time. Please visit our Advanced Hydrologic Prediction Service /AHPS/ web page for specific area rivers and lakes observations and forecasts. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...Thompson NEAR TERM...KL/Thompson SHORT TERM...Thompson LONG TERM...Frugis AVIATION...Frugis/KL FIRE WEATHER...Thompson HYDROLOGY...Thompson
Area Forecast Discussion
National Weather Service Bismarck ND
942 PM CDT Sat Jul 27 2019 .UPDATE... Issued at 941 PM CDT Sat Jul 27 2019 Thunderstorms have pushed into southwest North Dakota. Quite a bit of lightning has shown up with these storms, but so far they have remained tame. Expect this trend to continue. For late evening update have increased precipitation chances and cloud cover through the night. UPDATE Issued at 650 PM CDT Sat Jul 27 2019 Convection remains to the south and to the west of our area, but a couple storms are set to push across the Montana border. Current forecast is handling this well. && .SHORT TERM...(This evening through Sunday) Issued at 244 PM CDT Sat Jul 27 2019 Forecast highlights for the short term period include chances for thunderstorms, some possibly strong, and fire weather concerns. A shortwave trough currently near Yellowstone National Park will track eastward into South Dakota tonight. As the surface high drifts off to the east, southerly return flow setting up over the western Dakotas will help aid in thunderstorm development and maintenance this afternoon into tonight. Models depict this activity will largely be centered over South Dakota through tonight, with the northernmost activity extending to the I-94 corridor. Instability and shear may be sufficient for a strong to near-severe storm over far southwestern North Dakota late this afternoon and evening. Hail will likely be the main threat. Showers and storms will continue to track eastward across southern North Dakota late tonight into Sunday morning. A deepening upper level low currently over British Columbia/Alberta will quickly move east into Manitoba on Sunday. Associated lee surface cyclogenesis is ongoing over eastern Alberta, and the system is forecast to become nearly stacked by Sunday afternoon. The attendant surface cold front will sweep across the Northern Plains on Sunday. Model consensus places the front from northwest Minnesota to Lake Oahe by mid afternoon. It is around this time that global and mesoscale models agree that convective initiation will occur along the front. What is uncertain though is how strong these storms will be. The RAP shows a potential for 2000 J/kg of CAPE with negligible CIN over far south central North Dakota into the James River Valley, but deep layer shear looks marginal (no more than ~30 kts) and low level shear appears generally unidirectional. Given an expected discrete storm mode, would not be surprised to see a few sustained updrafts capable of near quarter size hail. The threat for storms should end by Sunday evening as the cold front moves off to the east. Near critical fire weather conditions are forecast to develop behind the cold front over western North Dakota Sunday afternoon. Steep low level lapse rates along with seasonally strong cold air advection and surface pressure rises should promote strong momentum transfer in the boundary layer, with soundings indicating a mix-down potential of 30 to 35 kts. The strong boundary layer mixing should yield surface dewpoints in the mid to upper 30s, at least for a few hours. This results in relative humidity values around 20 percent from mid to late afternoon. Because fuels are still relatively green, will hold off on issuing any fire weather products at this time. .LONG TERM...(Sunday night through Saturday) Issued at 244 PM CDT Sat Jul 27 2019 The synoptic pattern for next week calls for upper level high pressure over the Southern High Plains, placing North Dakota at the northern edge of broad upper ridging. This setup will give us a warming trend and periodic chances for showers and thunderstorms as various disturbances pass over the top of the upper ridge through much of next week. Both the GFS and ECMWF show a stronger shortwave moving through toward the end of the work week. Instability and shear may be sufficient for strong to severe storms at times, but it is far too early to nail down any specifics. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 650 PM CDT Sat Jul 27 2019 Scattered thunderstorms possible primarily over southern areas tonight, and mainly over eastern areas on Sunday. Otherwise, VFR conditions expected. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJS SHORT TERM...Hollan LONG TERM...Hollan AVIATION...JJS
Area Forecast Discussion
National Weather Service Denver/Boulder CO
841 PM MDT Sat Jul 27 2019 .UPDATE... Issued at 838 PM MDT Sat Jul 27 2019 Have cleared out the chance of storms out of the foothills, urban corridor and adjacent plains as storms continue over the far eastern plains and the northern mountains. Should see the rest of the activity die down over the next 2 to 3 hours. The HRRR and NAM-Nest still show some hints of storms, currently over far northwestern Colorado, continuing over the mountains after midnight and through sunrise as the upper trough translates across the area. This seems plausible so have kept the slight chance in the forecast. Other than that, no changes are needed to the forecast. && .SHORT TERM...(This evening through Sunday) Issued at 222 PM MDT Sat Jul 27 2019 Storms associated with a shortwave trough will be ongoing this evening mainly across the plains with a few isolated storms elsewhere. The SPC mesoanalysis page is indicating precipitable water values near 1.3 inches over the far eastern plains, so heavy rain and minor flooding will be possible with the strongest storms. The axis of the mid level shortwave will move through northern Colorado late tonight and into early tomorrow morning. This may provide enough forcing for a few showers especially over the northern mountains but any showers that do form will be very light due to the lack of instability. POPs were increased during this time period to indicate a slight chance of rain. AVA on the backside of the departing shortwave will provide subsidence over our CWA on Sunday. Winds at the surface will turn northerly over the plains with gusts up to 30 mph. Precipitable water values will be much lower as the downslope flow dries conditions out. A few stray showers and storms may form during the afternoon but very little rainfall is expected due to the aforementioned dryness. Otherwise, highs will be about the same as Saturday with more sunshine. .LONG TERM...(Sunday night through Saturday) Issued at 222 PM MDT Sat Jul 27 2019 A slight chance for thunderstorms will continue into Sunday evening. A warm layer above 500mb will make any substantial vertical difficult. In addition to this, the dry airmass will keep chances for thunderstorms very low through Sunday evening. The weather over the upcoming week will be mainly influence by the position of the upper level high over the southwest U.S. On Monday, the high will be centered near the Four Corners. Clockwise flow around the ridge will keep the monsoon moisture to the west of Colorado. An easterly low level flow will bring moisture to areas east of the mountains. Warm mid levels and a lack of forcing will keep storms isolated at best. The ridge slowly wobbles to the east Tuesday through Thursday, this will allow monsoon moisture to slowly increase over the Central Rockies. At this time, best chance for thunderstorms appear to be on Thursday when a short wave trough embedded in the southwest flow aloft tracks across the region. Limited shear and instability will keep the severe threat low. Heavy rain will be the biggest issue, mainly on Thursday. Temperatures through mid week look to be near normal with readings in the upper 80s to lower 90s. Chances for start to decrease on Friday as the ridges starts to retrograde back to the west. This starts to cut off the monsoon moisture. There still should be enough moisture and instability for isolated to scattered storm coverage Friday. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 838 PM MDT Sat Jul 27 2019 Storms have since pushed far east, with no more expected tonight. Winds were southerly from outflow of previous storms, and will trend toward drainage tonight before a cold front pushes through the area tomorrow morning. Winds will turn northerly during the mid to late morning with gusts up to 25 knots. The stray storms that may form over the mountains tomorrow should not reach the airports. VFR ceilings and visibility are expected through Sunday evening. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Kriederman SHORT TERM...Danielson LONG TERM...Meier AVIATION...Kriederman
Area Forecast Discussion...UPDATED
National Weather Service Cheyenne WY
839 PM MDT Sat Jul 27 2019 .UPDATE... Issued at 839 PM MDT Sat Jul 27 2019 Quick update as we head into late evening. Dropped PoPs across the CWA with loss of instability. CAMS not showing much if any redevelopment behind the main line of storms exiting to the east. We also canceled the Flash Flood Watch for Niobrara, Northern Souix, and Dawes counties given we don`t see much any re- development into the area and storms that moved through earlier were progressive in movement. Otherwise, much less in the way of showers and thunderstorms expected for tomorrow, with greatest coverage (chance PoPs) expected across the Nebraska Panhandle. && .SHORT TERM...(This evening through Sunday) Issued at 138 PM MDT Sat Jul 27 2019 Summary: Scattered to numerous showers and thunderstorms ongoing and expected to continue through the afternoon and evening hours. Main thunderstorm hazards will be localized heavy rainfall, frequent lightning, and wind gusts of 30 to 40 mph in the strongest of outflows. Storm strength will decrease through the late evening as they shift from Wyoming into Nebraska Panhandle and then farther east. A Flash Flood Watch remains in place as storms will be slow moving and could produce locally high rainfall amounts causing local road and poor drainage impacts this afternoon through early Thursday morning. Weather Details: A shortwave trough analyzed via water vapor satellite and RAP output is shifting across central WY this afternoon and aiding enhanced synoptic lift. Combination of this lift and modest instability near 1250 J/Kg MLCAPE and eroding MLCIN is supporting scattered to numerous showers along with isolated to scattered thunderstorms over the high terrain and High Plains of Wyoming so far this afternoon. Deep layer shear remains 20-25 knots and thus overall storm mode will be pulse-like with clusters that propagate along multi-directional outflow boundaries. Anomalously high PWATs near 1" to 1.25" across east Wyoming and even higher into the Nebraska Panhandle are supporting the large coverage of showers and storms. This will also heighten the risk for localized heavy rain in the slow storm motion environment that could result in local flooding impacts. SPC HREF continues to highlight Niobrara and northern Nebraska Panhandle into SD for pockets of concentrated rainfall where the combination of synoptic lift combines with instability, storm- clustering, slow storm motion, and greater PWATs. Main time frame for flash flooding potential will be this afternoon for Niobrara and spread east into Nebraska through late afternoon through late evening and early overnight hours as shortwave exits 08-12Z Sunday Morning. Some upscale growth in the clustering could occur into a semi-organized MCS in Nebraska and this could exacerbate flooding impacts. Future shifts may need to evaluate convective trends if this upscale growth occurs and if the Flash Flood Watch may need to be cancelled early before 12Z Sunday. .LONG TERM...(Sunday through Friday) Issued at 303 AM MDT Sat Jul 27 2019 Storms will dissipate late tonight and early Sunday as the ridge builds back in temporarily. A few showers and thunderstorms will be possible again Sunday afternoon and evening, though coverage should remain isolated to widely scattered. Heavy rain will again be possible with any stronger storms. The overall pattern will remain essentially the same through the extended as the ridge remains in place and shortwave disturbances rotate through. Warm temperatures and afternoon convection will be the status quo through mid week. By mid week, ridging will increase with 2 to 3 DAM 12 hour height rises expected Wednesday and Thursday. This should limit convection somewhat and keep things quite warm. High pressure will continue to dominate the the western 3rd of the CONUS through the remainder of the forecast cycle. Models are in good agreement of keeping temperatures warm with periods of isolated convection in the afternoons. More robust convection will be likely with any stronger shortwaves that develop in the flow aloft, although these will be difficult to resolve beyond 2 and 3 days out. Expect continued warm weather with showers and thunderstorms possible in the afternoons and evenings. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 633 PM MDT Sat Jul 27 2019 Scattered thunderstorms moving across eastern Wyoming and the Nebraska Panhandle early this evening with periods of thunderstorms with gusts to near 40 mph expected at times Scottsbluff, Alliance, Chadron and Sidney. Will keep vicinity showers at Cheyenne given weakening showers may work into the Cheyenne area. Will leave a period of thunderstorms through 02Z for Laramie with small area of storms moving through that area, and vicinity showers out near Rawlins through the early evening. CAMS showing activity weakening as we go past sunset. We did bring in some MVFR ceilings across the Nebraska Panhandle late tonight into early morning. && .FIRE WEATHER... Issued at 138 PM MDT Sat Jul 27 2019 Fire weather concerns will remain low today despite the number of thunderstorms and lightning as most of the storms should have adequate rain with them and not pose a dry lightning risk. Overall minimum humidity values will remain elevated today with scattered to numerous showers and storms across the region. Drier and warmer temperatures look to the in store for Sunday and into early next week. Zone 304 is now labeled to have critical fuels and Humidity will drop near 15 percent Sunday and Monday. Winds look to remain below 25 MPH at this time but elevated to near-critical conditions appear possible in Zone 304 over the coming days. If winds, look to be higher, a short-term Red Flag may be needed. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ UPDATE...JG SHORT TERM...JSA LONG TERM...AL AVIATION...JG FIRE WEATHER...JSA
Area Forecast Discussion
National Weather Service Green Bay WI
1023 PM CDT Sat Jul 27 2019 Updated aviation portion for 06Z TAF issuance .SHORT TERM...Tonight and Sunday Issued at 232 PM CDT Sat Jul 27 2019 The latest RAP analysis and satellite/radar imagery show a cold front slowly dropping south from southwest WI to about Appleton and Kewaunee early this afternoon. Mixed layer instability ahead of the front is gradually increasing upwards of 1200 j/kg over east-central WI, though the clouds along the front are behaving due to poor convergence and lack of large scale ascent. It remains uncertain whether storms will develop over east- central WI this afternoon or develop further south. With further destabilization, the highest chances for storms will occur from about Oshkosh to Kewaunee in the 3 pm to 7 pm time period. Some guidance, particularly the hrrr, keeps precip south of Manitowoc, so chances will remain below 30 percent for east-central WI in general. Brief gusty winds and small hail will be the main threats in the strongest storms. Looking elsewhere, weak high pressure is shifting east to the north of the front over the northern Mississippi Valley, with widespread fair weather clouds popping from northern Minnesota into northern WI. Tonight...The front remains forecast to continue to move south into southern WI or northern IL by early Sunday morning. The weak surface high should move into the area after midnight, which will promote clearing skies within a cooler and drier airmass. This should set the stage for patchy fog to develop north and west of the Fox Valley in the early morning hours. Cooler low temps ranging from the mid 50s north to mid 60s over the southern Fox Valley. Sunday...As shortwave energy moves east over the Dakotas and Minnesota, increasing southwest winds will cause the front to return northward during the day. This front will push across much of north-central and into east-central WI in the afternoon, causing thunderstorm chances to increase. With daytime heating, mixed layer instability is projected to increase to 1500 j/kg over central WI, so not out of the question that a few strong storms could develop at peak heating. Effective shears of 20 kts, however, will limit storm organization, and most likely keep storms rather pulsey in nature. Temps will be similar to todays readings and range from the low to mid 80s. .LONG TERM...Sunday Night Through Saturday Issued at 232 PM CDT Sat Jul 27 2019 The main issue in the long-term portion of the forecast will be the potential for showers and thunderstorms Sunday night into Monday before quiet weather moves in for much of the work week. Sunday night into Monday: A surface low is expected to lift from northwest WI to eastern Lake Superior by 12Z Monday. At the same time, the low is expected to deepen as shortwave energy and a deeper upper-level trough approaches from the Plains. As the low deepens, a warm front is expected to lift northward through the area through the evening hours, followed by a cold front overnight into Monday morning. South of the warm front and ahead of the approaching cold front, instability will increase into the early evening hours across the area. Models are generally showing between 500 and 1000 J/kg of MUCAPE with deep layer shear values around 20 to 25 knots along and ahead of the cold front. The better shear/instability would be early in the evening before instability decreases into the late evening and overnight hours. A few strong to severe thunderstorms are possible, but the limited amount of shear and decreasing instability would likely limit this to the early evening hours. Otherwise, the added forcing along the cold front and increased moisture will allow shower and thunderstorms to push through the area from west to east throughout the night into Monday morning. Some heavy rainfall is possible under any thunderstorms as PWAT values are progged to be between 1.5 to 2.0 inches along and ahead of the front. It does look like the line of storms would be transient enough to keep flooding from be a greater concern. By Monday afternoon, drier air will filter in from the west as a surface ridge builds into the area. Aloft, the upper-level trough axis will slide directly overhead. This will mainly lead to some gusty afternoon winds up to 25mph as deeper mixing occurs. Otherwise, much quieter weather will move in for the afternoon hours. Highs will be in the upper 70s to low 80s, coolest central/north-central. Overnight lows will be in the 60s for most locations. Monday night through Thursday: The aforementioned surface ridge will continue to build across the western Great Lakes through this time period, keeping fairly tranquil weather in place. Some afternoon fair weather CU may develop each day, especially Tuesday and Wednesday as the area will be on the western side of the slowly departing upper-level trough. Otherwise, look for partly cloudy skies, generally light winds and more comfortable temperatures through this time period. High temperatures will be in the mid to upper 70s to near 80. Overnight lows will drop into the 40s and 50s. Rest of the extended: The high pressure system is expected to shift slowly off to the east through this time period, allowing the next system to approach from the west. As is typical this far out, model solutions differ on how quickly the surface ridge slides eastward. At this point, will stick with a blend of the models, bringing an increase in temps, some cloud cover and low precip chances by next weekend. && .AVIATION...for 06Z TAF Issuance Issued at 1020 PM CDT Sat Jul 27 2019 A weak frontal boundary continues to sag south and away from the area late this evening. Convection firing along the boundary will drift off to the south as well. Quiet weather is still expected for the rest of the night as a low-level ridge shifts through the region. There is some potential for fog, but it`s been a while since most areas received significant rainfall so still plan to only carried it at the most climatologically favored locations. Quiet weather with good flight conditions will persist through the morning and into the early afternoon hours Sunday. Convection is likely to begin spreading across the area as the frontal boundary advances back to the north during the afternoon. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......Cooley AVIATION.......Skowronski
Area Forecast Discussion
National Weather Service Houston/Galveston TX
1006 PM CDT Sat Jul 27 2019 .DISCUSSION... Showers and thunderstorms that affected portions south of I-10 and east of I-45, dissipated during the evening hours with the loss of diurnal heating. Mostly clear skies along with light and variable winds are expected tonight. Low temperatures are expected to range between the mid and upper 70s. Sunday, onshore flow is expected to continue along with low level moisture transport from the Gulf increasing rain chances. During the morning hours, passing showers could develop across the local waters and move northward into the coastal regions of southeast TX. During the afternoon hours, development of showers and isolated thunderstorms can be expected inland, particularly along shower and sea breeze boundaries as diurnal heating peaks. High temperatures will again range between the low to mid 90s. 24 .AVIATION... 00Z Aviation...Still a few well inland isolated showers remaining, and these should dissipate during the next hour or two. Expect slightly more shra/tsra overage tomorrow aft as compared to today. S winds will continue. 33 PREV DISCUSSION... /ISSUED 317 PM CDT Sat Jul 27 2019/ SHORT TERM[Tonight through Sunday]... Isolated showers and storms have formed near KHOU this afternoon along the sea breeze and other outflow boundaries from earlier convection. Isolated storms should continue to pop up the next couple of hours given enough moisture, daytime heating and convergence along boundaries. Storms should dissipate towards the evening hours as heating is lost. Main impacts from the storms will be brief heavy rain, lightning and gusty winds. Tomorrow should be similar to today with storms developing with heating during the day. Models do show increased moisture with higher precipitable water. Hi-res models show a bit more scattered activity than today so decided to go with 40 PoPs mainly with a few spots near 50 percent. Temperatures should be relatively persistent with highs in the mid 90s like today and yesterday. Overpeck MARINE... A light to moderate S-SE flow will prevail this weekend into early next week with high pressure over the central Gulf of Mexico and a weak trough of low pressure in the lee of the Rockies. Scattered showers and thunderstorms will be possible the next few days as higher moisture from the central Gulf moves into the region. Better chances of storms are expected mid week. Overpeck AVIATION [18Z TAF Issuance]... Latest radar trends and vis satellite show some TCU developing mainly just E and SE of KIAH. Temps are hitting upper 80s so another hour or two from reaching convective temps based on soundings in the area. HRRR trends have shown convection developing near KHOU/KIAH/KCXO so decided to do a VCTS for a couple hours this afternoon. Kept rest of the TAFs dry based on this guidance. Also looks like VFR conditions are expected although we will need to monitor KCLL to KUTS for MVFR conditions in the morning. May also see some patchy fog at KCXO and KLBX but low enough confidence not to include in TAF for now. Overpeck LONG TERM [Sunday night through Saturday]... Large upper ridge over southern and central Rockies will remain the dominant weather feature for us as it holds through the week. This will keep somewhat unsettled weather in play, especially for mid-week when a shortwave trough will ride down the front side of the ridge and could increase rain chances Tue and Wed. Otherwise, expect a fairly uniform weather week near climatology with temps away from the water rising well into the lower to mid 90s each day pushing max HIs into the triple digits. Evans && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 76 95 76 97 75 / 10 30 10 20 20 Houston (IAH) 77 93 77 95 77 / 10 50 10 30 10 Galveston (GLS) 82 88 82 89 80 / 20 30 10 20 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ Discussion...24 Aviation...33
Area Forecast Discussion
National Weather Service North Platte NE
640 PM CDT Sat Jul 27 2019 .SYNOPSIS... Issued at 318 PM CDT Sat Jul 27 2019 H5 analysis from earlier this morning had high pressure located over southern Arizona. Ridging had flattened over the western CONUS over the past 24 hours as a trough of low pressure approaches the Pacific northwest. East of the main trough, a secondary trough of low pressure extended from eastern Idaho into northern Utah. East of this feature, a weak upper level disturbance was lifting across sern Wyoming and nern Colorado, and had led to a shroud of mid and high level cloudiness across western and north central Nebraska. Light rain showers and even an isolated thunderstorm or two had developed and was present across western and north central Nebraska midday. With partly to mostly cloudy skies present across the forecast area, 2 PM CDT temperatures ranged from 81 at Ainsworth to 90 at Imperial. && .SHORT TERM...(This evening through Sunday night) Issued at 318 PM CDT Sat Jul 27 2019 The main forecast concern in the near term is precipitation chances and severe potential tonight. Right out of the gate, there are some significant timing differences between the HRRR and NAM12/NAM NEST solns this morning. The HRRR is 3 to 6 hours faster with the onset of convection over the panhandle. The HRRR develops storms in the western panhandle around 21z with the NAM NEST around 23z and the NAM12 around 2-3z. ATTM, believe the NAM12 is way too slow with the onset of precipitation in the forecast area and have opted for the faster HRRR/NAM NEST solns. That being said, went ahead and slowed down the onset of precipitation in the grids this evening as the inherited forecast had pops mentioned across all of north central Nebraska by early evening. As for the threat of severe storms, it appears fairly limited given the forecast 20 to 30 KTS of deep layer shear. Low level winds remain very weak PER the 12z LBF sounding, so most of the shear is of the mid level variety. This would favor potential for strong wind gusts and marginally severe hail with the hail threat being early on. The wind threat should carry over into the overnight as convection takes on a more linear mode. As for precipitation chances, they will be highest over the northern forecast area as the short range solutions focus the nose of the low level jet across the central and northern sandhills overnight. Overnight, a cold front will pass through the western half of the forecast area with this feature clearing the remainder of the forecast area Sunday afternoon. The threat for thunderstorms will linger in the east at least through midday Sunday before exiting to the east along with the front. Drier and cooler temps are expected behind the front with highs Sunday in the middle 80s. .LONG TERM...(Monday through Saturday) Issued at 318 PM CDT Sat Jul 27 2019 High pressure aloft will build east into the southern Rockies, then southern high plains early in the work week. The next shot of precipitation is expected Monday night into Tuesday as a warm front lifts east across the forecast area. Behind the warm front, warmer temperatures will set in with readings returning to the 90s in the west. However, some decent model differences are noted between the GFS and ECMWF solns this afternoon. Most notably, the degree of cooler air which tries to back into the eastern forecast area next week. The GFS is much stronger with this cooler air and the latest MEX guidance latches on to this. The ECMWF is warmer and is the preferred solution attm. In fact, the EC soln builds the high into the TX panhandle by Thursday with a significant amount of heat building into the high plains Thursday into Friday. The GFS soln has the high farther southwest, with a cooler soln for western Nebraska. In light of the model differences, a blended forecast yields widespread 80s with temps approaching 90 in the west next week. Will stick with this soln for now, but wouldn`t be surprised if forecast temps trend warmer as we approach the middle of next week. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 640 PM CDT Sat Jul 27 2019 The primary aviation weather concerns for western Nebraska are thunderstorms, wind shear, and low ceilings. Scattered thunderstorms will overspread the Sandhills tonight, affecting the northern terminals the most (KGRN, KVTN, KANW, KONL). Gusty erratic winds, rapid drops in cigs/visby from heavy rain, and hail are possible. TSRA overage will be more isolated farther south (KOGA, KLBF), but the low level jet will result in wind shear conditions. As the storms are moving east overnight, surface winds will switch to southwest and eventually northwesterly. MVFR cigs are possible for northern Neb toward dawn Sunday. Low clouds give way to mid/high clouds Sunday morning, but northwest surface winds will be rather gusty in the afternoon. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Buttler SHORT TERM...Buttler LONG TERM...Buttler AVIATION...Snively
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
929 PM EDT Sat Jul 27 2019 .SYNOPSIS... High pressure will reside over the Mid-Atlantic through the weekend, then move offshore early in the coming week. A cold front will approach from the Ohio Valley towards the middle of the week. && .NEAR TERM /THROUGH SUNDAY/... At 01Z, several isolated showers west of the Blue Ridge are progressing eastward. 00Z HRRR has this activity diminishing in areal extent and lasting until about midnight, with the majority of the activity not making it east of the Blue Ridge. Patchy fog will develop overnight west of the Blue Ridge, especially in those areas that had showers this evening. Min temps overnight near normal, with lows near 70F in the I-95 corridor, and mid 60s generally west of I-95 corridor. The exception will be in sheltered valleys in the I-81 corridor, where lows around 60 are likely, along with patchy fog. Sunday will start sunny except in those locales that have patchy fog, which will burn off rapidly by 9 AM. Expecting cumulus to form around noon, similar to today. High temps Sunday will be a couple of degrees warmer than today, and the dewpoints will rise about 5 degrees warmer than today. So overall, it will not feel as comfortable on Sunday as today with higher dewpoints causing higher heat indices in the lower-to-mid 90s. Additionally, the HREF is showing isolated shower activity generally north of I-66/US50 mid-afternoon through sunset, so I have added this feature to the forecast. No severe weather or marine hazards expected for Sunday attm. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... After whatever activity pushes east or weakens Sunday evening, the balance of Sunday night will turn out dry. With the southerly flow continuing, it will again be a little warmer and more humid, with lows staying in the upper 60s to 70s. Patchy fog/mist will again be possible in more rural locales inland. Monday, the trough and front to the west will begin to move closer, though locally, a ridge will actually build aloft. Combined with the continued southerly flow, and Monday should continue the slow creep upward in heat and humidity, with widespread low 90s and a few mid 90s. Heat indices may reach within 5 degrees of advisory levels, but think they stay below. With the ridge nearby still, convection may remain suppressed much of the day, though something isolated will be possible especially in the mountains, or along the Mason-Dixon line. Whatever does develop should dissipate in the evening, however, and Monday night will turn out just like Saturday and Sunday night, just a little warmer and more humid than Sunday night. && .LONG TERM /TUESDAY THROUGH SATURDAY/... On Tuesday a mid to upper level trough will be embedded over the eastern CONUS as a surface front extends along the eastern Great Lakes and into the Ohio Valley. This will enhance the development of showers and thunderstorms especially west of the Blue Ridge. The front will slowly move into our region Wednesday into Thursday which will increase cloudiness and will maintain the chance for showers and thunderstorms each day, especially in the afternoon/evening hours as it is enhanced by diurnal heating. The mid/upper level trough axis moves away on Thursday and surface front lingers near our region Friday into Saturday. This will continue the trend of afternoon/evening showers and thunderstorms, but will depend on location of the frontal boundary. If it moves further south, the end of the week could be drier. && .AVIATION /01Z SUNDAY THROUGH THURSDAY/... Pop-up shower impacting KMRB with MVFR conditions for vsby attm. This shower will also add to the potential of MVFR for mist at KMRB between 08Z-11Z. Otherwise, VFR through Monday night all terminals overall. Isolated TSRA possible Sunday afternoon for KMRB, KBWI, and KMTN. Modest visibility reductions are possible at CHO and MRB during the early morning hours each of the next three mornings, but confidence not high enough to put restrictions in the TAFs for tonight just yet. An isolated shower or thunderstorm also cannot be ruled out, but odds are less than 15 percent, so also not included in the TAFs. Generally VFR conditions are expected between Tuesday and Friday, with periods of sub-VFR condition during afternoon/evening shower/thunderstorm activity. && .MARINE... High pressure will provide light winds through most of Sunday. Late in the day and at night, southerly channeling is expected to develop as the high moves offshore, which may bring marginal SCA conditions to portions of the open bay. This probably wanes during the day Monday but may return Monday night. Did not yet have confidence to issue an SCA yet. Otherwise, most of the time should be storm-free, but an isolated shower or thunderstorm cannot be completely ruled out Sunday afternoon/evening and again Monday afternoon/evening. Odds generally less than 15 percent. Showers and thunderstorms are possible in the afternoon/evening hours over the waters between Tuesday and Friday. Periods of SCA conditions are possible each day as well. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...RCM NEAR TERM...Lee SHORT TERM...RCM LONG TERM...IMR AVIATION...Lee/IMR/RCM MARINE...IMR/RCM
Area Forecast Discussion
National Weather Service Melbourne FL
824 PM EDT Sat Jul 27 2019 .UPDATE... East coast breeze and outflows have made it made it west of metro Orlando with a slight chance shower/thunderstorm chance for the far western interior including Lake county for a few more hours. Stronger storms near Lake Okeechobee may allow for some convective development to push back toward the east coast, supported by the HRRR model, but think coverage will remain in isolated range for southern portions of the forecast area and have also capped POPS around 20 percent there. Expect another late evening update to remove POPs entirely for the overnight as convection diminishes with loss of daytime heating. Lows in the lower to mid 70s. && .AVIATION... Isolated convection should remain mainly west of all terminals into late evening before dissipating. Generally VFR conds overnight with CHC SHRA/TSRA for cstl terminals into early to mid afternoon and then progressing toward the interior. Have included VCTS most terminals for Sunday afternoon. && .MARINE... Light onshore flow expected this evening then expected a trough to develop across the waters by late tonight. Seas generally up to 2 ft with some 3 ft seas possible across the nrn offshore waters in a NE swell. && .PRELIMINARY POINT TEMPS/POPS... DAB 73 88 73 88 / 10 50 30 50 MCO 74 93 74 93 / 10 50 20 60 MLB 74 90 74 89 / 10 40 30 60 VRB 72 90 72 90 / 10 40 30 50 LEE 75 93 74 92 / 20 50 20 60 SFB 74 92 74 92 / 10 50 20 60 ORL 75 93 75 92 / 10 50 20 60 FPR 72 90 72 90 / 20 40 30 50 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ Volkmer/Sedlock
Area Forecast Discussion
National Weather Service San Francisco Bay Area
842 PM PDT Sat Jul 27 2019 .SYNOPSIS...Strong high pressure will maintain hot conditions for the interior valleys and hills through Sunday. Seasonably mild weather will persist along the coast with a shallow marine layer and light onshore flow in place. Cooling will begin to develop inland by late Sunday afternoon as the next upper level trough approaches the coast and onshore flow starts to ramp up. By Monday temperatures will cool significantly across inland areas as a well established marine layer and stronger onshore breezes return. Temperatures are then expected to remain near or slightly below seasonal averages for the rest of next week. && .DISCUSSION...As of 8:40 PM PDT Saturday...Building high pressure aloft pushed inland temperatures sharply higher today, particularly in the hills and interior valleys. Meanwhile, a persistent shallow marine layer close to the ocean, combined with light onshore flow, kept coastal areas seasonably mild. There was a hefty 50 degree spread today between the coolest and hottest high temperature in our forecast area: from a foggy 59 at Ocean Beach in San Francisco to a sizzling 109 at the southern Salinas Valley town of Bradley in southern Monterey County. Despite the hot temperatures inland, no record highs were set or tied today. Current Fort Ord profiler data shows that the marine layer depth has decreased to slightly less than 1000 feet. The Half Moon Bay Airport is currently reporting a visibility of 1/2 mile and it`s likely there will be patchy dense fog near the immediate coast overnight and into Sunday morning. A forecast update was completed earlier in the evening to add patchy fog to most coastal zones tonight and early Sunday. The upper ridge will maintain very warm to hot conditions across our inland areas into Sunday. High`s tomorrow are expected to be similar to today for the interior valleys and hills, and overnight lows tonight will likely be slightly warmer than last night. Some locations in the hills may not cool below 80 overnight. Heat Risk is expected to remain moderate to high in the warmest inland valleys and hills through tomorrow. Therefore, the Heat Advisory for the East Bay Interior Valleys and Hills, and all inland portions of Monterey and San Benito Counties, will continue through Sunday. The upper ridge is forecast to begin to break down late on Sunday as an upper trough begins to develop offshore. This will trigger an inland push of marine air starting late Sunday afternoon and continuing through Sunday evening. Thus, the coastal valleys will likely see some cooling already tomorrow. All areas will experience significant cooling by Monday as gusty onshore winds and a deepening marine layer provide relief. The inland valleys are forecast to cool by as much as 20 degrees by Monday. The models agree that a weak upper trough will persist just off the West Coast through much of next week. Thus, temperatures for the entire work week are expected to be near normal, or slightly cooler than normal. Looking at the longer range, the ensemble mean from both the GFS and ECMWF shows an upper ridge rapidly strengthening near the Four Corners late next week and then expanding westward across California next weekend. Thus, we may see another warm weekend for interior portions of our area, although probably not as warm as this weekend. && of 4:45 PM PDT Saturday...Upper level high over the area has compressed the marine layer. Strong northerly gradients are developing as well with the ACV-SFO gradient at 6.4 mb. This will keep stratus out of the SFO Bay Area tonight. Low confidence of fog at STS. Stratus along the coast should spread into the MRY Bay Area but later than usual. Will have to watch the smoke from wildfire in southern Oregon. Northerly flow may blow some smoke over the Bay Area tonight with slight impacts to slant-range vsbys. This is supported by the HRRR Near-Surface Smoke Model. Vicinity of KSFO...VFR. Northwest winds 15-18 kt decreasing after 04Z. SFO Bridge Approach...VFR. Monterey Bay Terminals...Stratus along the immediate coast but it should stay out of MRY and SNS until after midnight. && .FIRE WEATHER...As of 8:30 PM PDT Saturday...Humidity recovery will be poor once again on Saturday night for elevations above 1000 feet. Very warm and dry conditions will persist across inland areas through Sunday. However, winds will remain light through early Sunday afternoon. Main period of concern is late Sunday afternoon and evening when the initial inland push of marine air gets underway. Gusty westerly winds late Sunday afternoon and evening will initially be dry which could create a short duration of critical conditions. Onshore winds will bring significant cooling and much higher relative humidity values by late Sunday night and Monday. The higher hills will still remain quite dry Sunday night but even those areas are expected to to see significant improvement by Monday night as the marine layer deepens. && of 04:29 PM PDT Saturday...Breezy to locally gusty northwest winds across the outer waters as well as the inner waters north of Point Reyes for the rest of Saturday. Northwest winds strengthen across the waters Sunday. The sea state will continue to be dominated by shorter period wind generated waves along with a light southerly swell. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...Heat Advisory...East Bay Interior Valleys and Hills, Interior Valleys and Hills of Monterey and San Benito Counties SCA...Pt Arena to Pt Reyes 0-10 nm SCA...Pt Arena to Pigeon Pt 10-60 nm SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm from 3 AM && $$ PUBLIC FORECAST: Dykema AVIATION: W Pi MARINE: DRP FIRE WEATHER: Dykema Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Pocatello ID
211 PM MDT Sat Jul 27 2019 .SHORT TERM...Tonight through Monday. Expect mainly isolated thunderstorms and scattered showers in the Upper Snake River Highlands. Will be most likely in the Island Park area south through Driggs and Victor. Isolated storms are also possible across eastern Custer County and northern Butte County. Much lesser chances will occur through sunset southwest of those regions. Will have widespread dry conditions on Sunday with some 20 to 25 mph wind gusts in the Snake River Plain. There will be a much increased chance of showers and thunderstorms on Monday as an upper level system moves through Idaho. Temperatures are expected to remain above normal Sunday and Monday. GK .LONG TERM...Tuesday through Saturday. The trend in the long term is hot conditions with isolated thunderstorms expected Wednesday through Saturday. Temperatures are expected to remain above season normals for late July and early August. GK && .AVIATION... Will have VFR conditions through Sunday. Have isolated thunderstorms in southeast Idaho this afternoon and evening and have VCTS at all TAF sites other than Burley and SUN. Sunday will be clear skies across the board. Expect 10 to 15 knot upvalley afternoon winds at PIH and IDA and SUN. GK && .FIRE WEATHER... A shortwave trough is expected to generate iso to sct showers and iso t-storms this afternoon across the Central Mntns, northern half of the Snake Plain (much of Zone 410), and the MT/WY border regions, with all activity shifting east over time. Hi-res HREF ensemble members and HRRR offer a reasonable consensus on this scenario. Unlike yesterday when widespread clouds prevented sfc heating and destabilization, satellite trends reveal our region has cleared from the Snake Plain west, and cumulus development is in progress across the Central Mntns as we warm toward convective temps. Latest SPC mesoanalysis shows a weak capping inversion of warmer air up around 3,000 feet has nearly mixed out, with SBCAPE (surface instability) values now 500-1,000 J/kg north/west of the Snake Plain, so we should be a go for storms. The overall severe wx risk is low, but rising DCAPE (downdraft instability) values 1,000+ J/kg and still an "inverted-V" flavor to NAM soundings due to fairly dry low-levels suggest that storms will be capable of producing gusty/erratic outflow winds in excess of 45 MPH, and isolated storms north of Challis are already producing abundant lightning. These will be the greatest fire wx threats today, especially for Zones 476/410/411. We still feel comfortable with the iso storm coverage currently in the forecast, so we will not be issuing a Red Flag. Storms should largely be out of Zone 476 by 7 PM, ending everywhere by 11 PM. Sun looks drier and breezy as a westerly zonal flow cuts off monsoon moisture to our south. Min RHs may drop below 15% critical thresholds in NE Zone 425, western Zone 410, and the valleys of Zone 476. Winds may also approach critical thresholds in portions of the Snake Plain, but overall seem a bit marginal for pulling the trigger on a Red Flag at this time. Zone 476 will be very close across the valleys, but even here the strongest winds will focus on the mid and upper slopes, a bit displaced from the driest low-level air in the valleys. Will headline the near-critical conditions in the FWF, but here too have opted against a Red Flag. No t-storm issues are expected, but that will change Mon as another weak shortwave approaches from the SW. This feature is impossible to clearly identify upstream today, so confidence in how it will impact our region is on the low side, but model consensus favors iso to sct showers/t-storms regionwide Mon afternoon. Will hold storm coverage at iso for now, but lightning and perhaps gusty winds could again be risks. The trade-off will be slightly higher RH values and slightly lower winds, all shy of critical. RHs may dry Tues/Wed, but we will need to monitor the evolution of monsoon moisture rotating around a high pressure ridge across the Four Corners. - KSmith/GK && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$