Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/25/19

Area Forecast Discussion
National Weather Service Boise ID
830 PM MDT Sat Aug 24 2019 .DISCUSSION...Smoke from the Cow wildfire in southwestern Baker County has so far stayed out of Snake Basin, but HRRR smoke model says some smoke will come in tonight. Mesowest data shows widespread west-northwest winds 15 to 25 mph across eastern Oregon this evening, and north winds near Mountain Home, but relatively light winds in the rest of the Snake Basin. Radar at 8 PM MDT showed a gust front with 25 to 30 mph winds moving south near Vale, OR. A dry cold front is expected in our CWA later this evening but no significant increase in winds is expected. Temps will lower tonight and Sunday, however. Current forecast already has this. No updates. && .PREV DISCUSSION... SHORT TERM...Tonight through Wednesday...A dry cold front will pass through the area this evening. Expect breezy northwesterly winds this evening. Cooler air behind the front will move into the area later tonight and highs on Sunday will be about 10 degrees cooler than today. Expect mostly clear skies to continue Monday through Wednesday with near normal temperatures for this time of year. It is also worth noting that high resolution visible satellite imagery continues to show a small smoke plume emanating from the Cow wild fire in southwestern Baker County that is generally blowing toward the east. The Cow wild fire is located upwind from the Treasure Valley and will be monitored closely in case it produces a larger plume of smoke. LONG TERM...Wednesday night through Saturday...An upper ridge will move across the Intermountain West Wednesday into Thursday as residual moisture is pulled from the weakening tropical storm in the Pacific. Deterministic models are now hinting at showers and thunderstorms associated with this wave of moisture while the NBM is maintaining nearly zero chance of showers. PoPs were nudged upward but remain low. The upper ridge amplifies by Thursday, allowing for dry southwest flow that will increase temperatures roughly 7-10 degrees above normal. && .AVIATION...VFR. Scattered high clouds. Visibility locally limited by smoke. Surface winds west-northwest less than 10 kts, increasing to 10-20 kts with gusts to 30 kts after 18z Sunday. Winds aloft at 10k feet MSL west 30-40 kts becoming northwest 20-30 kts after 18z Sunday. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ DISCUSSION...LC AVIATION.....JT PREV SHORT TERM...JB PREV LONG TERM....AL/LC
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
743 PM CDT Sat Aug 24 2019 .DISCUSSION...Developing MCS-type system over northeastern Nuevo Leon has impressive cold cloud low as -88C just after 7 PM...and the activity has oozed into southern Starr County. CAMs are in different camps...with the HRRR most on target with what`s happening in the near term. Based on convective trends and the HRRR...expect heavy rainfall/slow moving thunderstorms to continue to ooze along US 83 through Starr and into southwest Hidalgo County through 9/10 PM before winding down fairly steadly through midnight. For this reason...ramped up PoP to 60/70 percent and broad-brushed QPF to a little over an inch through 1 AM...though some pockets will see 3 to 4 inches as is typical with these situations. Would not surprise if we needed a flash flood warning along US 83 later this evening and we`ll be watching radar/satellite trends closely. Farther east...expect "debris" light rain to reach into central/eastern Hidalgo as well as western Cameron after 9/10 PM and likely ending around midnight or so...but with plenty of mid/high level clouds remaining for much of the night. Current forecast low temperatures may need a nudge downward across the upper Valley but expect ~80 or so to be the rule with the cloud cover and despite any light rain from McAllen eastward. 52/BSG && .AVIATION...Main issue is overnight with big convection/MCS flareup in Nuevo Leon, northwest Tamaulipas, and into Starr County between 7 and 730 PM and what may ooze toward McAllen/Miller Airport. Given that these systems can have a mind of their own, decided to add a 4SM TSRA there between 9 and 1 AM (most likely for the front end) along with variable but gusty winds since wake lows/mesohighs can create fairly strong gusts. Held at 25 knots for now. For Harlingen, kept visibility restriction out but did mention rain but no thunder as expect the rumbles to fade out before the remnants move into western Cameron (still may see lightning, though). Kept Brownsville out altogether as models and satellite/radar trends suggest minimal push too far to the east overnight. That said, plenty of mid/high clouds so those have been added to forecast, and expect winds outside of any nearby mid Valley convection to be light. For Sunday...did add a PROB30 for afternoon thunder in McAllen, but kept the Lower Valley terminals out of the mix for the time being. CAMS (models) and latest GFS suggesting minimal activity and rain chances are closer to 20 percent than 30 percent. Still, old boundaries from what happens tonight could become a factor on Sunday...and will let later shifts decide how to handle the mention of any sea-breeze enhanced activity. Otherwise...the usual wind forecast with VFR cumulus and leftover mid/high decks (early) with sea breeze enhanced southeasterlies by mid afternoon. 52/BSG && .PREV DISCUSSION... /issued 352 PM CDT Sat Aug 24 2019/ SHORT TERM (Now through Sunday night): Mid-level troughing and a weak area of low surface pressure continues across the Northwestern Gulf of Mexico and slowly drifts northward through the short term. Inland, convection has been largely dependent on seabreeze initiation, which has developed along the coast this afternoon. Shower and thunderstorm chances will increase from east to west through the rest of the day, with pockets of heavy rainfall possible. This evening, models bring a high QPF signal with a weak vorticity maximum southward into the northern ranchlands. This combined with precipitable water values exceeding 2.25" should result in scattered showers and storms, some of which may produce locally heavy rainfall in Jim Hogg, Zapata and Starr counties. These areas are also in moderate to severe drought, so any rainfall should be welcomed. The only concern will be low-lying and poor drainage urban areas, which could still see minor flooding with torrential rainfall rates in the heaviest activity. After the seabreeze moves through the lower RGV, rain chances should diminish there this evening. Sunday, isolated to scattered showers and storms will be possible again with seabreeze development. Don`t expect as much coverage as today with little mid to upper level support. However, enough deep moisture should be enough for some heavy downpours once again. Temperatures will be above normal again with highs nearing 100 in the lower RGV to 100 to 104 out west in the Upper RGV. Dew points in the mid to upper 70s may result in heat indices reaching Heat Advisory criteria across Cameron, Willacy and Kenedy counties. LONG TERM (Monday through Saturday): The long term begins with Deep South Texas being sandwiched between a building upper-level ridge across the Desert Southwest and a mid-level trough axis draped across the Western Gulf of Mexico. Long-range forecast models continue to agree on the ridge building over Western Texas through the first half of the week, with the eastern periphery affecting the CWA. The ECMWF is persistent developing a slightly stronger ridge compared to the GFS. Will continue to lean towards this solution for now, resulting in hot and mostly dry conditions through much of the upcoming workweek. High temperatures are expected to continue to be about 2 to 5 degrees above seasonal normal through at least Thursday. Monday could see heat indices reach in excess of 111 degrees and we`ll monitor for possible issuance of a Heat Advisory. At the surface, the pressure gradient from high pressure over the eastern Gulf and thermal troughing over Northern Mexico will gradually weaken through the week, with only light to moderate breezes during the afternoon hours. Rain chances are expected to be very limited through most of the upcoming week as ridging suppresses convection development. Did include silent 10 PoPs for areas east of US 281/I69C each afternoon through Thursday, with a very slight chance of isolated sea breeze activity. By Friday, models are actually in pretty decent agreement that the upper-level pattern begins to shift. The ridge over the southwest CONUS retrogrades westward, allowing an inverted trough/cut-off low (that originates over the Caribbean/Florida region) to progress westward across the Gulf of Mexico through next weekend. With the ridge retrograding, a weakness in the upper-level flow should allow temperatures to decrease to near or even slightly below sensual average. In addition, both GFS and ECMWF show an influx of moisture advecting in from the Gulf, increasing precipitation chances. MARINE (Now through Sunday night): Weak surface troughing across the northwestern Gulf will keep pressure gradient minimized offshore. With winds slightly higher a bit closer to the coast, seas will climb up to 4 feet from time to time. Finally, showers and storms will be possible throughout the short term marine period. There may be higher winds and seas in the stronger storms. (Monday through Saturday): A moderate to strong pressure gradient at the surface will lead to moderate south to southeasterly winds and moderate seas through at least Wednesday. The pressure gradient is expected to weaken for the second half of the week, which will help to result in weaker breezes and subsiding seas. Small craft exercise caution wording will likely be needed each afternoon/evening through Wednesday for the Laguna Madre and possibly the near-shore Gulf waters. Low end small craft advisory for wind conditions could be possible Monday afternoon/evening on the Laguna Madre. At times, rain showers and perhaps a thunderstorm may be possible, generally offshore. There may be locally higher winds and seas in any stronger storms. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 80 94 82 95 / 20 30 10 10 BROWNSVILLE 81 98 81 97 / 30 20 10 10 HARLINGEN 80 99 81 100 / 30 30 10 10 MCALLEN 82 101 82 102 / 60 30 20 10 RIO GRANDE CITY 81 103 80 104 / 70 30 20 10 SOUTH PADRE ISLAND 82 89 82 89 / 20 30 10 10 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ This product is also available on the web at: HTTP://WEATHER.GOV/RGV 52/99
Area Forecast Discussion
National Weather Service Columbia SC
1037 PM EDT Sat Aug 24 2019 .SYNOPSIS... A cold front will stall south of the area Sunday. A system off the Florida coast through the weekend will move northward and off the Southeastern Coast early next week. This will help keep a chance for showers and storms in the forecast. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Cool, dry air will move into the area tonight behind a cold front. Moisture will be shallow, limiting PoPs overnight to a slight chance of a light showers or drizzle. Temperatures have been far cooler than model guidance so far tonight and lows will likely be cooler than even the coolest model guidance. Lows may be in the low to mid 60s over much of the area. Expect stratus to remain in place overnight with wind helping to limit the chance of fog. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... The cold front will be just off to the south of the forecast area on Sunday. Surface high pressure centered well off to the north across the upper Mid-Atlantic and New England regions will be ridging southward into the region through the period. Surface low is forecast to develop off the Florida peninsula on Sunday, then track northeastward off the southeastern coast into Monday. This low is being monitored by the Hurricane Center for possible development. Even so, the low is expected to remain offshore. Some Atlantic moisture from the low offshore may push inland enough to bring some cloud cover on top of the wedge flow, and may be able to produce a few showers across the eastern most portions of the cwa each afternoon. The expected clouds will combine with the northeasterly low-level flow to actually help to keep afternoon temperatures below normal both Sunday and Monday. && .LONG TERM /TUESDAY THROUGH SATURDAY/... The surface ridge will still be across the area beginning Tuesday, although it will be weakening as a deepening upper low across the upper Mid-west pushes eastward. This will drive another cold front towards the region by Wednesday, and east of the cwa by Thursday. The stronger upper energy associated with this system is forecast to remain well off to the north of the region, but still can not completely rule out some organized convection over the area by midweek. By the end of the week, showers and storms will be isolated to scattered, and more diurnal. Temperatures will rebound back to being close to normal by the end of the week, with readings in the upper 80s to low 90s. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... The cold front has moved south of the region this evening. Weak cold air damming developing with ridge building south from the Mid Atlantic and weak trough along the coast. Ceilings are lowering across the area from north to south with IFR/MVFR conditions. The HRRR and Lamp indicate ceilings will remain low overnight as stratus/strato-cu dominates. MVFR forecast ceilings through Sunday as wedge may strengthen with low pressure offshore and ridge building south from the Mid Atlantic. Rain chance appears minimal with no significant lift. EXTENDED AVIATION OUTLOOK...Widespread IFR or MVFR conditions may linger during much of the outlook period because of a front remaining in the region. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$ SYNOPSIS...99 NEAR TERM...99 SHORT TERM...99 LONG TERM...99 AVIATION...99
Area Forecast Discussion
National Weather Service Charleston SC
1038 PM EDT Sat Aug 24 2019 .SYNOPSIS... A cold front will cross through the region tonight, then stall just offshore and south of the region on Sunday. Low pressure is expected to pass well offshore early next week, before another cold front impacts the area later in the week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... As of 1035 PM: Based on radar trends, I will update the forecast to reduce PoPs over land for tonight. In addition, I will populate the hourly temperatures with rain-cooled observations. As of 920 PM: KCLX indicated a cluster of thunderstorms over the Charleston Tri-county area, tracking SW between 10-15 kts. Additional showers and thunderstorms may develop along the cold front, currently sliding across the radar site. As the front pushes offshore late tonight, convection should easily develop as the front approaches the Gulf Stream. I will update the forecast to align with latest trends. As of 735 PM: KCLX detected a fine line from Georgetown Co. west across Berkeley and Dorchester Counties, west to the Savannah River Site. This line was sliding south between 10-15 kts. Based on surface observations, I suspect that this fine line is associated with the cold front, or the leading edge of cold air damming. I will update the forecast to increase PoPs along and south of the front, especially the CHS Tri-county area. Previous discussion: The cold front will continue moving southwards through our area this evening, probably becoming located south of our area by late tonight. Then, distant high pressure will build from the north. The main convective threat should be with and ahead of the front this evening, mainly across our GA counties. Instability isn`t overly impressive, so the severe risk is low. However, PWATs ~2.25" or 2 standard deviations above normal will lead to potentially very heavy rainfall. Combined with light steering winds aloft, local flooding in low-lying and poorly drained areas is possible. The heaviest precipitation will trend southwards with the front this evening. Models generally show another area developing along the SC coast while inland areas trend drier. We indicated this in the grids, but wouldn`t be surprised if more changes need to be made based on radar trends. Low clouds and maybe even some patchy fog cannot be ruled out late tonight. Lows should be in the 70s. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... Sunday and Monday: A cold front will slowly progress to the coast and likely stall just offshore and/or south of the area to start off the week. As this occurs, a cooler wedge-type pattern will follow, initially setting up across the Midlands Sunday, then eventually nudging closer to parts of Southeast South Carolina and inland Southeast Georgia on Monday as the quasi-stationary front drifts further south. The position of the front will dictate most precip coverage across the area through Monday and also keep any tropical low development/track well offshore over the Atlantic. Precip chances should be highest near the Southeast Georgia coast on Sunday, where PWATs remain between 2.00-2.25 inches near the southward moving front. Precip chances could persist into Monday, mainly across southern most locations near the Altamaha River where moisture lingers behind the front. Overall instability will remain quite low under cloudy skies both days with little to no threat of severe weather anticipated. Brief heavy rainfall will be the main concern given deep moisture levels and weak wind fields in place. High temps will be a few degrees below normal each day, peaking in the mid 80s across much of Southeast South Carolina and mid/upper 80s across Southeast Georgia, warmest near the Altamaha River. Overnight lows should range in the upper 60s/lower 70s well inland to mid/upper 70s near the coast. Tuesday: A quasi-stationary front should remain just south of the region, but a wedge-like pattern should weaken across the Southeast United States in advance of a mid/upper lvl trough of low pressure and associated sfc cold front approaching from the west. Some guidance suggests what is left of a large cluster of thunderstorms currently ongoing across the western Gulf of Mexico to phase with the longwave trough before shifting toward the area into midweek (bringing higher precip chances to the area). Regardless, a developing southwest sfc flow should advect deeper moisture to the region while mid/upper lvl forcing and the sfc front arrive late, likely after sunset. Given the anticipated pattern, scattered to numerous showers and/or thunderstorms are possible later in the day, highest chances west of I-95. Temps should warm a few degrees more than the previous day with highs generally ranging in the mid/upper 80s (coolest along the coast) to around 90 degrees across inland locations of Southeast Georgia. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A tropical low off the mid-Atlantic coast Tuesday night will continue to lift northeast away from the region on Wednesday. Another cold front is forecast to cross the area later Wednesday or Thursday. The front will likely stall off the coast through late week while high pressure builds inland. Given the front lingering in the vicinity, rain chances will remain in the forecast. Highest PoPs will be near the coast. Temperatures are expected to be near normal. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... Prior to the 0Z TAFs, KCLX detected a fine line from Georgetown Co. west across Berkeley and Dorchester Counties, west to the Savannah River Site. This line was sliding south between 10-15 kts. Based on surface observations, I suspect that this fine line is associated with the cold front, or the leading edge of cold air damming. HRRR and radar trends indicate that showers and thunderstorms that have develop upstream KCHS along the front will track over the terminal between 0Z-3Z, I will highlight with a TEMPO. KSAV may see a thunderstorms pass within the vicinity between 0Z and 3Z. Later tonight, in the wake of the front, forecast soundings indicate saturated conditions developing under a LLVL inversion. Given the forecast soundings and MOS, I will indicate MVFR condition at KCHS with IFR ceilings at KSAV. KCHS will be positioned between the wedge sfc high to the west and a possible developing low near the Gulf Stream, creating a decent pressure gradient. I will indicate gusty NE winds at KCHS by 15Z. Extended Aviation Outlook: Flight restrictions are possible at both CHS and SAV terminals Sunday and Monday, mainly due to lower cloud ceilings and showers associated with a building wedge-type pattern across the area early next week. Brief flight restrictions will also be possible with showers/thunderstorms ahead of an approaching cold front Tuesday into the middle of next week. && .MARINE... Update: Gusty conditions have developed in the wake of the cold front. I will issue a Small Craft Advisory for the Charleston Co waters for tonight through Sunday night. Tonight: A cold front will move through the waters this evening, becoming located to our south after midnight. Meanwhile, high pressure will be far to our north. The interaction between these two features will cause the surface pressure gradient to become elevated, leading to increasing winds. Expect NE winds to increase to 15-20 kt across our SC waters, including Charleston Harbor, after midnight. Gusts could approach 25 kt just before daybreak, which is just short of Small Craft Advisory criteria. Our GA waters should have winds of 10-15 kt. Seas will build to 2-4 ft in response to these winds. Sunday through Thursday: High pressure will build across inland areas behind a cold front shifting south of the area early next week while tropical low pressure tracks well east of the area offshore. The pattern will likely result in a tightening pressure gradient over coastal waters Sunday and Monday, favoring north/northeast winds 15-20 kts and seas building up to 4-5 ft. Conditions could approach Small Craft Advisory levels for a period on Sunday or Monday before the tropical low departs north/northeast of the region Tuesday. Conditions will then remain well below Small Craft Advisory levels through midweek. Rip currents: Increasing east/northeast winds could contribute to an enhanced risk of rip currents on area beaches late this weekend into early next week, especially if tropical low pressure intensifies while tracking well offshore. && .TIDES/COASTAL FLOODING... Astronomical tides will be running close to minor Coastal Flood Advisory levels next week and onshore winds could lead to even higher tides, mainly during the evening high tide cycles starting Monday. In addition, there is the potential for some heavy rain around the times of high tide which could exacerbate any flooding issues. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...Small Craft Advisory from 5 AM Sunday to 6 AM EDT Monday for AMZ350. && $$ NEAR TERM...NED SHORT TERM... LONG TERM...ETM AVIATION...NED MARINE...NED TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Dodge City KS
557 PM CDT Sat Aug 24 2019 ...Updated aviation discussion... .SHORT TERM...(This evening through Sunday) Issued at 153 PM CDT Sat Aug 24 2019 Convection developing across northern Kansas still looks likely this afternoon ahead of a approaching 400mb PV anomaly and where the better moisture and instability will be preset during the mid to late day. This area of developing afternoon storms will move southeast overnight across western and central Kansas as the upper level wave moves along the mid level baroclinic zone. At this time the CAMS seem to agree that this developing cluster of storms will march south along and east of highway 283 during the overnight hours. At this time am little concerned that this may be a little too far east given the instability axis and 10-14c 700mb temperature gradient from the RAP earlier this afternoon. Have therefore favored the highs chance along and east of HWY 283 but also will be keeping some higher pops going further west, just in case. CAMS also seem to be in decent agreement with the timing of this event with a few isolated to widely scattered late day/evening storms followed by the main cluster of thunderstorms after sunset. Given the instability and shear late day/early evening these isolated/widely scattered storms will be capable of producing large hail (+2 inches) along with strong gusty winds. The threat of severe weather will then shift to strong winds and heavy rainfall after sunset as the main cluster of storms overnight pass. Rainfall rates of 1 to 2 inches an hour possible which may lead to some localized flash flooding. The bulk of the overnight convection will be tapering off east of a Larned to Coldwater line early Sunday morning as an upper level trough moves into Central Kansas. Subsidence behind this upper level trough will also bring clearing skies from west to east. Based on clear skies and 850mb temperatures at 00z Monday the highs Sunday afternoon are expected to comb back into the 90s across much of southwest Kansas. Highs only in the 80s are expected where the clouds will clear out last and that will be east of a Dighton to Dodge City line. .LONG TERM...(Sunday night through Saturday) Issued at 153 PM CDT Sat Aug 24 2019 An upper level trough embedded in a northwest flow will move across the northern plains late Sunday night/early Monday. As this upper level system moves east into the Western Great Lakes Region late Monday a surface cold front will move across southwest Kansas. Exact timing of this frontal passage is still somewhat unclear but ahead of this cold front the highs on Monday will be in the lower 90s while north of this boundary some cooler 80 to 85 degree high temperatures will be possible. A few scattered thunderstorms will also be possible late day along this cold front. If the models are correct with the frontal position by late Monday, then the area most favorable for these storms will be near the Oklahoma border and across south central Kansas. This cool down early next week may be around for several days given that both the GFS and ECMWF agree with another upper level trough moving across the Northern Plains Tuesday which will bring a reinforcement of cooler air into the Central Plains. Along will the cooler temperatures continuing mid to late week there will also be a chance for scattered rain showers or thunderstorms mid to late week. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 557 PM CDT Sat Aug 24 2019 Thunderstorms are expected to develop and move across southwest and central Kansas through the evening into the overnight hours. There is uncertainty as to expected coverage, especially over the far southwest Kansas terminals, but any storms that develop in this area will likely be severe with 50+ knot winds, damaging hail and possible tornadoes. Farther east the Dodge City and Hays terminals could have better chances of being impacted by storms with the same severe weather threats. The storms should be moving southeast out of the region by 067-07z with MVFR to IFR stratus developing across much of the area later tonight into Sunday morning. && .PRELIMINARY POINT TEMPS/POPS... DDC 64 89 67 88 / 70 10 10 10 GCK 64 91 64 86 / 30 10 0 0 EHA 63 95 66 90 / 20 10 0 10 LBL 66 94 66 91 / 30 10 0 10 HYS 64 83 67 81 / 80 10 10 20 P28 67 85 69 91 / 80 10 10 20 && .DDC WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch through Sunday morning for KSZ030-031-043>046- 064>066-078>081-087>090. && $$ SHORT TERM...Burgert LONG TERM...Burgert AVIATION...Gerard
Area Forecast Discussion
National Weather Service Green Bay WI
1047 PM CDT Sat Aug 24 2019 Updated aviation portion for 06Z TAF issuance .SYNOPSIS... Issued at 224 PM CDT Sat Aug 24 2019 Another quiet day tomorrow, then some showers and thunderstorms Monday into Monday night. Seasonably cool and mainly dry weather will settle into the area for the latter part of the work week. Slow progression of the large scale pattern is expected for the next few days. That will allow the upper ridge presently across the area to shift to the East Coast, while an amplifying trough pushes east across the Plains. The trough will slow mid-week as an upper low closes off over western Ontario, then begin to lift toward northeast Canada late in the week. The expected large scale pattern is probably more typical of early autumn than late summer. Though day-to-day temperature variations are expected, readings will generally be AOB normal. The main precipitation event will be tied to the passage of a frontal system through the area Monday and Monday night. While a widespread significant rainfall is likely during that time frame, only a few rounds of scattered light showers are expected during the rest of the period. The result will probably be near to slightly below normal amounts for most locations. && .SHORT TERM...Tonight and Sunday Issued at 224 PM CDT Sat Aug 24 2019 The latest RAP analysis and satellite/radar imagery show high pressure centered over northern Ontario but stretching across much of the western Great Lakes early this afternoon. Onshore winds and daytime heating have contributed to a widespread cu field across the region. Temperatures are running a degree or two warmer than yesterday. Looking upstream, the next system is moving slowly over the Plains with a narrow moisture channel extending from the Gulf Coast to North Dakota. Because of the strong high over the Great Lakes, this system will be slow to approach the area. So the main forecast concerns continue to revolve around clouds and temps for tonight and Sunday. Tonight...The center of the sprawling high pressure system will slowly shift east to the eastern Great Lakes, northeast Ontario and Quebec. The pressure gradient will tighten somewhat with wind trajectories remaining out of the southeast. 1000-850mb winds are projected to remain until 20 kts, which usually indicate surface winds will decouple. But with a little more wind in the boundary layer, lows should be a little warmer than last night, and range from the low 40s north to mid 50s over the southern Fox Valley. Clouds should dissipate with loss of heating early this evening. But a few clouds may also drift into northeast WI from off Lake Michigan late tonight. Sunday...High pressure will continue to slowly drift away from the region while the system over the Plains moves into the Mississippi Valley. Trajectories out of the southeast will continue to provide a steady stream of dry air in the mid and lower levels. However, forecast soundings and the cu rule indicate should see ample fair weather clouds build again by late morning. Low level temps continue to warm, which should put highs in the low to middle 70s. .LONG TERM...Sunday Night Through Saturday Issued at 224 PM CDT Sat Aug 24 2019 The main long-term forecast issue is honing in on the timing of precipitation with the frontal system crossing the area at the start of the work week. Overall, the 12Z guidance trended slower with the arrival of the precipitation and with the timing of when the bulk of the rain will fall. Adjusted the forecast (PoPs and QPF) accordingly. The southwest portion of the forecast area was included in the marginal risk of severe weather on the morning SPC SWODY3 product. The 12Z guidance suite indicated limited destabilization will occur during the day, so at this point the risk of severe storms does not appear great. Deep westerly flow behind the front will support temperatures a little above normal on Tuesday, then readings will drop to below normal for a couple days as the large-scale upper trough settles over the region. Scattered light showers will also be possible at times, especially across the north. The default forecast initialization grids based on a broad-based blend of guidance products seemed reasonable, so no significant changes were necessary. && .AVIATION...for 06Z TAF Issuance Issued at 1043 PM CDT Sat Aug 24 2019 Skies will become mostly clear overnight with some mid and high clouds across portions of central and north-central Wisconsin. A few more lake clouds may drift inland along the lakeshore late tonight, before fair weather clouds become more widespread again by around 15z Sunday. Areas out to the west will become broken at times Sunday afternoon, with bases around 3500 ft. The cumulus clouds will dissipate Sunday evening, however high clouds will increase ahead of an approaching low pressure system from the west. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......Skowronski SHORT TERM.....MPC LONG TERM......Skowronski AVIATION.......Kurimski
Area Forecast Discussion
National Weather Service North Platte NE
640 PM CDT Sat Aug 24 2019 .SHORT TERM...(This evening through Sunday night) Issued at 342 PM CDT Sat Aug 24 2019 Forecast concerns will be thunderstorms into this evening followed by fog development late tonight. A mid and upper level trough currently extended from western South Dakota through western Nebraska into central Kansas. One lead disturbance is moving from central into eastern Nebraska. A second disturbance was located over the panhandle into extreme northeast Colorado. This disturbance will dig southeast across southwest Nebraska into north central Kansas overnight. Mesoscale models including the HRRR and RAP13 indicate the best area for thunderstorms into early this evening from southeast Lincoln into Hayes and Frontier County. Locally heavy rainfall is possible along with gust winds and hail. A chance for thunderstorms across eastern areas tonight to also diminish or end after midnight. As stratus develops over the area tonight, areas of fog are expected to develop after 09Z and linger until 15Z Sunday. This should mainly occur near an south of Highway 2. Locally dense fog is possible through the morning commute as much drier air moves in at the 850-500mb layer. Sunday, after morning fog lifts across the southern half of the area, stratus will erode from west to east. Stronger heating in the west to bring highs to the upper 80s far western zones, while in the east, highs only mid to upper 70s. An upper trough moving into the Northern Plains will bring a chance for thunderstorms to the Dakotas. Isolated thunderstorms could move into northern Cherry county late afternoon. Increasing chances for thunderstorms Sunday night as the upper trough and cold front pushes through western Nebraska. A belt of strong deep layer shear will extend from Wyoming into western Nebraska. Thunderstorms should develop into a linear MCS or two as they move across portions of north central Nebraska. Damaging winds will be the main threat, also isolated large hail is also possible. Further south and west, chances fall to a slight chance where models indicate little or no development. .LONG TERM...(Monday through Saturday) Issued at 342 PM CDT Sat Aug 24 2019 Showers and thunderstorms should linger into Monday morning across the eastern half of the area with skies becoming mostly sunny. Behind the cold front, highs from 75 to 80 with a breezy north to northwest wind. Late Monday night into Tuesday, a chance for showers and a few thunderstorms on the backside of the upper trough. A reinforcing cold front and increased cloudiness will hold highs on Tuesday to only the upper 60s to lower 70s. Mainly dry conditions until Thursday night through Saturday. During this time disturbances will track from the Pacific Northwest across the Central Plains. Organized thunderstorms are not expected however. Highs from 75 to 80 Wednesday and Thursday cool into the low to mid 70s for Friday and Saturday. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 640 PM CDT Sat Aug 24 2019 For the KLBF terminal: Thunderstorms will be possible in the vicinity of the terminal through mid evening. Ceilings will fall to IFR levels overnight and fog will be possible at the terminal after 11z Sunday. Visibilities may fall down to 1 to 2 miles. Clouds will scatter out Sunday afternoon with VFR conditions expected after 19z. For the KVTN terminal: Showers will be possible in the vicinity of the terminal through mid evening. Ceilings tonight will range from 3000 to 5000 FT AGL. Ceilings will increase to 7000 FT AGL Sunday morning. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Roberg LONG TERM...Roberg AVIATION...Buttler
Area Forecast Discussion
National Weather Service Paducah KY
628 PM CDT Sat Aug 24 2019 .SHORT TERM...(Tonight through Monday night) Issued at 251 PM CDT Sat Aug 24 2019 High pressure centered over the Great Lakes into eastern Canada continues to make its presence felt, with comfortable ENE flow across the area offering tolerable dew points and afternoon temps in the mid 70s to near 80. Pesky showers over the Ozarks continued to make it as far east as Carter and Ripley counties. Will carry limited PoPs into this evening generally west of Highway 67, with increasing clouds east of the MS River. Generally used the HRRR for precip trends into the evening. Overnight, mainly late, PoPs should increase over the southwest 1/2 of the area, especially SEMO into far west KY, the southern tip of IL. Showers and isolated thunderstorms expected, with the best chance of storms toward TN/AR state lines. Sunday, good chance PoPs for convection, driven by an evolving H5 trof to our west that will strengthen SSW moist flow over the area, along with providing lift and instability. Those chances will continue Sunday night into Monday as heights fall with the H5 trof axis moving overhead. Should see a decrease in PoPs by afternoon and early evening. This will be in advance of an approaching cold front to our northwest that will offer up yet another chance of convection late. More on that (for Tuesday), in the long term section. Temperatures were generally a MOS/NBM blend. We went a couple of degrees cooler for Sunday and Monday given the expected clouds and rain. .LONG TERM...(Tuesday through Saturday) Issued at 251 PM CDT Sat Aug 24 2019 The medium range models continued to have a solid signal for a surface cold frontal passage during the day Tue, driven by a lobe of shortwave energy to the southeast of a vortex centered near Hudson Bay. Showers will be likely across the PAH forecast area, with at least scattered thunderstorms moving through. The deeper moisture should be scoured out by evening, thus pcpn coverage will wane significantly Tue night. A reinforcing shot of dry air is progged by the models to sweep into the region on Wed. The initialization blend, modified with 50% CONSAll data, supported a small possibility of an isolated shower or two, with a few lightning strikes, popping up mainly in the southern third of the region on Wed afternoon. After that, the extended forecast looks essentially dry under west-northwest flow aloft and high surface pressure. For Fri/Sat (Days 6&7), some models indicated another mid level shortwave may drive another mostly dry surface cold front through the region. There were significant timing differences with this feature, thus any confidence of associated pcpn during this time frame is low. If it was to rain anywhere, it would be in the northwestern fringe of the region. Once the high-dewpoint air is out of our region (starting Tue night), expect mild conditions for this time of year, with dewpoints mainly in the 60s. && .AVIATION... Issued at 628 PM CDT Sat Aug 24 2019 For the 00z Sunday WFO PAH TAF issuance, VFR conditions will dominate for all of the TAF locations through at least 18 Sunday. Lowered ceilings into MVFR category for KCGI and KPAH as the surface warm front works back northward through these locations. Otherwise, middle (5k-10kft) and high level (above 20kft) clouds associated with the elevated warm front will dominate all of the WFO PAH TAFs with this forecast issuance. Vicinity showers are representative of rain chances in the scattered PoP category, with the higher PoPs (>55 percent) depicted by a categorical mention of rain, as noted in the KPAH TAF site. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ AVIATION...Smith