Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/02/17

Area Forecast Discussion
National Weather Service Bismarck ND
926 PM CDT Sun Oct 1 2017 .UPDATE... Issued at 919 PM CDT Sun Oct 1 2017 Thunderstorms have ended across northern North Dakota and most of the showers also. Still expecting a surge of moisture and showers moving up into the southeast late tonight. Several of the CAM models are trending this shower area east of the James River Valley. Trimmed POPs east late tonight from likely to chance. UPDATE Issued at 704 PM CDT Sun Oct 1 2017 The precipitation trends are following the CAM model forecasts pretty well so feel confident the majority of showers and thunderstorms will be out of the southeast within one to two hours and the rest of the north during the evening. The threat of severe weather has greatly diminished so have removed the mention of severe from the forecast. UPDATE Issued at 458 PM CDT Sun Oct 1 2017 This update will focus on POPs along the line of thunderstorms moving through south central North Dakota. Expect this line to continue moving northeast with time over the next 3 hours then exit the region. Upped POPs and QPF. && .SHORT TERM...(This evening through Monday) Issued at 213 PM CDT Sun Oct 1 2017 Forecast highlights in the short term period will continue to be showers and thunderstorm chances now through early this evening. Still expect a window for strong to severe storms 19-01Z today over my central and east, more so my south central and southeast. Currently, large trough of low pressure remains over the western CONUS with strong southwest flow aloft over the Northern Plains. Strong embedded S/WV impulses rotating around the trough and lifting northeast across the region resulting in showers across eastern MT/western ND and across the upper Mississippi. Surface trough over the central Dakotas will be the focus for possible strong to severe storms this afternoon as we destabilize. Clearing has been occurring the past few hours along the trough axis and has led to CU development over south central ND. ESRL HRRR has consistently focused convective initialization in this area between 19-20Z. SPC earlier moved the marginal risk farther west for severe thunderstorm potential, just east of Minot and Bismarck for the remainder of this afternoon into early this evening. This conditional severe threat seems plausible and supported by the latest CAM suites. 1000-1500 J/KG of MLCAPE and effective deep layer shear around 30 kts, will combine with strong sfc forcing and support aloft for a few organized updrafts. Main threats will be large hail (quarter to golf ball size) and winds up to 70 mph for the stronger storms. Given low cigs and 0-1KM shear a low end tornado threat will also exist. Precipitation will decrease from southwest to northeast early to mid evening as drier air advects into our area. Another strong embedded wave will bring a decent chance for showers to the James River Valley overnight. .LONG TERM...(Monday night through Sunday) Issued at 213 PM CDT Sun Oct 1 2017 Cooler temperatures this coming week, and perhaps a rain snow mix west Tuesday morning highlight the extended forecast. Upper level low develops Monday night over eastern MT and remains over the state through mid week before lifting northeast. This feature will keep some precipitation chances over our area through Tuesday. Temperatures in the mid 30s Tuesday morning across the west may support some potential for a possible light rain and snow mix, though will need to see what temperatures aloft do. Right now a mix would be more favored to our west. Highs generally in the 50s are favored through mid-week. Afterwards models show a wide spread of solutions. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 704 PM CDT Sun Oct 1 2017 00Z TAFs will be challenging this evening as the trends are quickly changing. Showers and thunderstorms scattered from KMOT to KJMS ending by 01-02Z. Showers with a mix of MVFR/IFR KDIK- KMOT-KBIS becoming VFR after 03-06Z. After 06z VFR expected at all taf locations. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...NH LONG TERM...NH AVIATION...WAA
Area Forecast Discussion
National Weather Service Hastings NE
641 PM CDT Sun Oct 1 2017 .SHORT TERM...(This evening through Monday Night) Issued at 225 PM CDT Sun Oct 1 2017 An active weather pattern is expected across the local area through the short term periods. With clearing to our west this afternoon...instability has been building ahead of an approaching cold front. Currently this front extends from near O`Neill Nebraska southwest into eastern Colorado. Can already see some cumulus starting to develop along the boundary...although nothing has yet to really take off. That said...with plenty of instability...effective shear values of 35 to 40 kts...and forcing from the front...think that it is only a matter of time before strong convection begins to initiate. With the aforementioned parameters...have no trouble imagining that organized convection will develop...with the potential for large hail...strong thunderstorm wind well as an isolated tornado or two. Will continue to monitor...but think that this convection will initiate to our west around 4 PM or 5 PM...making it to our western fringes by early evening...and spreading east across the forecast area during the mid evening through overnight hours. Short term model guidance is in fair agreement with this...with both the HRRR/RAP developing a line of thunderstorms and taking it east later this evening. With a developing LLJ on the warm side of this boundary...expect convection to persist through much of the overnight hours...but with the best potential for severe storms coming primarily before midnight. With the cold front expected to stall across the local area tomorrow...expect a fairly good temperature gradient to develop by afternoon...with highs in the lower 60s forecast for our north...and mid 80s forecast across out southeast. This front should also become a focal point for convection during the late afternoon and evening hours...with another chance for strong or marginally severe thunderstorms late in the day tomorrow. While severe potential does not look as great tomorrow...expect at least the potential for marginally severe hail and 60 mph winds gusts with the strongest storms through the evening hours. .LONG TERM...(Tuesday through Sunday) Issued at 225 PM CDT Sun Oct 1 2017 Continued unsettled weather is expected through much of the extended periods as a cold front meanders across the local area. This should keep temperatures near or slightly below normal...with multiple chances for showers and a few thunderstorms across parts of the local area...although severe weather appears unlikely at this time. The main frontal boundary will eventually shift southeast of the local area by next weekend...with dry conditions and a return to above normal temperatures returning next Saturday afternoon and Sunday. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Monday) Issued at 635 PM CDT Sun Oct 1 2017 Scattered severe thunderstorms across western KS and NE will continue eastward into the evening, eventually impacting both TAF sites, but also gradually decreasing in intensity. The HRRR model is handling the ongoing convection very well, so I have leaned on it heavily for this TAF issuance. The HRRR fills the ongoing storms into a well defined line that moves southeastward. This makes sense given the increasing low-level jet. As such I have included a brief period of prevailing TS at both sites. Some LLWS is also expected before the boundary passes through the area tonight. Behind this boundary, we could see cloud ceilings drop into the MVFR category into Monday morning. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ SHORT TERM...Rossi LONG TERM...Rossi AVIATION...Mangels
Area Forecast Discussion
National Weather Service North Platte NE
957 PM CDT Sun Oct 1 2017 .UPDATE... Issued at 957 PM CDT Sun Oct 1 2017 Dropped Severe Thunderstorm Watch at 10 PM CDT and removed severe wording from wx grids. UPDATE Issued at 859 PM CDT Sun Oct 1 2017 Updated to drop tornado watch. UPDATE Issued at 641 PM CDT Sun Oct 1 2017 Updated forecast to add north central zones in severe thunderstorm watch. && .SHORT TERM...(This evening through Monday) Issued at 327 PM CDT Sun Oct 1 2017 Strong forcing now moving into western Wyoming and Colorado per water vapor imagery. This will quickly overspread western and southwest Nebraska this evening, and expect rapid development of thunderstorms along a pacific cold front that extends from west of O`Neill to near Ogallala. This boundary will remain nearly stationary this evening, and we will have to watch areas of southwest Nebraska closely near the front for possible isolated tornado development. Backed near surface flow will increase this evening, and if a storm can remain discrete near the boundary, parameters are decent for isolated tornado development. Recent runs of the HRRR model suggests that many updrafts could limit the potential for storms to remain discrete. This would pose more of a wind and hail risk and less of a tornado threat. Front should clear the area by midnight, with only a few lingering rain showers behind the front. Surface low pressure will deepen across eastern Colorado Monday, which will stall the cold front just to our southeast during the morning. The front will actually drift back northward into the southeast portion of the area during the afternoon. Mid level instability will begin to increase by late afternoon as warm air advection and southerly low level jet increase. This will set the s stage for a round of elevated strong thunderstorm activity Monday night. As far as rainfall during the day Monday, expecting it to be scattered at best, but cannot rule out with persistent mid level warm air advection and isentropic lift through the day. .LONG TERM...(Monday night through Sunday) Issued at 327 PM CDT Sun Oct 1 2017 Both the NAM and GFS indicate the h850mb front will lift back north toward Ncntl Neb Monday night. 50-60kt h850-700mb winds produce strong moisture advection and the NAM indicates h800mb CAPE around 3000J/KG with strong shear aloft. The environment is generally post frontal suggesting a high potential for elevated thunderstorms capable of hail, perhaps large at times. The forecast carries a definite POP for showers and thunderstorms. K-indices are expected to rise into the upper 30s to lower 40s Celsius. A similar situation develops Wednesday with a warm front lifting back north in response to an approaching upper level wave. The forcing at the lower levels is weaker suggesting a less widespread rain event affecting areas south of highway 2. The last potential rain event develops Thursday night and Friday as the last of the upper level energy across the Wrn U.S. lifts east through the Plains. The models have a large range of tracks for the upper low and there has been a whole lot of wobbling day to day with each model forecast. Blended model data plus bias correction was the basis for the temperature forecast. The coolest weather is expected Wednesday; the result of 1030mb Canadian high pressure ridging southward through the high plains. Highs in the 50s are expected area-wide Wednesday. Otherwise highs in the 60s are expected until Saturday. Warmer weather returns Saturday and Sunday. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) Issued at 104 PM CDT Sun Oct 1 2017 A stormy late afternoon and evening is expected across western and north central Nebraska. Expect thunderstorms to develop this afternoon across the western high plains, and then move east across the area this evening. Temporary MVFR conditions are likely as the storms cross the area. Winds will be locally gusty to 40 kts as the storms pass as well. VFR and light winds are expected by Monday morning all areas. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Snively SHORT TERM...Taylor LONG TERM...CDC AVIATION...Taylor
Area Forecast Discussion
National Weather Service Miami FL
750 PM EDT Sun Oct 1 2017 .AVIATION... As easterly flow becomes deeper and more pronounced, shower activity will gradually increase as it moves offshore from Atlantic waters. VCSH is warranted after about 2z along the east coast and by mid- morning for Naples. TEMPO or prevailing groups may be needed for parts of Monday, but at this point its too early to pinpoint timing. Wind will be E around 10 KT tonight then increase to 15 to 20 KT during the day Monday. && .UPDATE... Most of the afternoon convection has ended at this time with a few brief streamer showers moving inland from the Atlantic. The latest short ranged models suggest these streamer showers will continue to move inland along the east coast metro areas through tonight. Tonight low temperatures will range between the mid to upper 70s. Easterly flow will continue tomorrow and increase in the afternoon hours as the ridge gradually builds over the region. Chance of scattered showers and thunderstorms will develop in the afternoon. Current forecast remains on track. && .PREV DISCUSSION... /issued 316 PM EDT Sun Oct 1 2017/ DISCUSSION...Latest surface observations and sat imagery show a more east to se flow already in place across the region with a few showers starting to develop over Palm Beach and Broward County and over Central FL. This easterly flow is advecting some moisture into the region, which will enhance more convection in the afternoon hours. Model guidance suggests this activity will persist this afternoon with the best chances remaining towards the ne and the interior counties. This activity will produce moderate to heavy rainfall with the main threat of brief periods of heavy rain that could cause minor flooding. Max temperatures will be around the 90s and cool down into the upper 70s tonight. Convection should diminish inland and transition over the Atlantic waters into the evening hrs. Next week, broad upper level ridge building over the northeast plains will help push weak boundary over the panhandle south along the FL peninsula. Surface gradient will also strengthen increasing to breezy to windy conditions through the week with the potential for numerous showers and storms. This feature will help to maintain deep tropical moisture over the region through midweek, which will continue the wet pattern with scattered to numerous showers. Models are hinting on another weak tropical wave moving into the region by the end of the week bringing even more deeper moisture into the area. This will continue the potential for more numerous showers and storms through the end of the week. Temperature are forecast to drop slightly along the east coast metro region down into the mid 80s, a couple degrees cooler than normal for this time of year. MARINE...Weak boundary over the panhandle of FL will enhance num showers and storms deteriorating marine conditions through much of the week. Ridge builds over the region and strengthen easterly winds across South Florida. This will result in a long period of windy conditions and high seas over the Atlantic waters. Small Craft Advisory are in effect for the Atlantic waters starting tonight and continuing through mid week. Monitoring the Gulf waters as conditions may also be near SCA as well, but at this time left SCEC conditions into Monday. AVIATION...Easterly flow prevails through the period 10-15kts at all sites with gusts 18-20kts will possible along the east coast this afternoon. Winds diminish 8-10kts after 02Z, though KFLL may remain around 12kts. Winds increase after 14Z tomorrow 12-15kts with gusts to 20kts through day. SHRA may impact KFXE- KPBI this afternoon, while other east coast sites look to remain dry until this evening. SHRA expected VCNTY KAPF through 00Z. SHRA expected to continue moving into the east coast through the upcoming TAF cycle. TSRA coverage looks limited, so no mention in forecast. May see MVFR cigs/vsbys with heaviest activity. BEACH FORECAST...The rest of today moderate risk of rip currents continues over the Atlantic waters and transition to high risk this week as easterly winds increase across the region. The elevated risk will likely persist through most of the week. A weak boundary over the region will maintain abundant moisture over South Florida providing periods of numerous showers and thunderstorms through the week. PREV DISCUSSION... /issued 128 PM EDT Sun Oct 1 2017/ AVIATION...Easterly flow prevails through the period 10-15kts at all sites with gusts 18-20kts will possible along the east coast this afternoon. Winds diminish 8-10kts after 02Z, though KFLL may remain around 12kts. Winds increase after 14Z tomorrow 12-15kts with gusts to 20kts through day. SHRA may impact KFXE- KPBI this afternoon, while other east coast sites look to remain dry until this evening. SHRA expected VCNTY KAPF through 00Z. SHRA expected to continue moving into the east coast through the upcoming TAF cycle. TSRA coverage looks limited, so no mention in forecast. May see MVFR cigs/vsbys with heaviest activity. PREV DISCUSSION... /issued 949 AM EDT Sun Oct 1 2017/ UPDATE...Low pressure trough still extends across the eastern Gulf of Mexico into North/Central Florida this morning, along with a broad upper level low and associated weak surface low off the east coast of Florida. These features will dampen out today as surface high pressure builds in from the NE and upper level ridging moves in from the west. Morning sounding came in with PWATs around 1.6" and warm midlevels around -5.5C. With winds becoming more easterly as the high builds in, we will advect a little better moisture, especially in the low levels, back into the region. With daytime heating, expect scattered to locally numerous showers to move from east to west across the area through the afternoon. Best chances will continue to focus around Lake Okeechobee and along the Gulf coast later in the afternoon. Can`t rule out a few storms, but overall expect mostly showers. Breezy conditions are expected along the east coast into this afternoon. PREV DISCUSSION... /issued 428 AM EDT Sun Oct 1 2017/ DISCUSSION... Latest IR satellite imagery shows a break in the cloud cover over south Florida with convection off of the northern Florida Atlantic coast. The 00Z MFL sounding indicated a thin layer of CAPE above 850 mb, with southerly winds 10 to 15 KT spanning from the surface up to the mid levels. NWS radar has been rather quiet this morning, with no distinct features to enhance shower activity. East southeast flow will advect in a moderate amount of moisture today with more widely scattered showers anticipated. Short range models, including the HRRR and WRF show limited activity developing this afternoon, with a couple embedded heavier storms. The main threat will again be brief heavy rain, and isolated cloud to ground lightning strikes. Maximum temperatures will approach the low 90s across the western peninsula and upper 80s for the east coast metro region, typical for this time of year. Through mid week: By Monday, models begin to build a dominant high pressure cell over the eastern CONUS and mid Atlantic waters, tightening surface pressure gradients, and increasing easterly flow over South Florida. A stationary boundary is forecast to remain stagnant across central Florida. This feature will help to maintain deep tropical moisture over the region through midweek, which will continue the wet pattern with scattered to numerous showers. Forecast GFS PWAT values should fluctuate from 1.75" to 2.25". Both the GFS and ECMWF show an easterly wave moving westward over the peninsula from Wednesday into Thursday. This would act to further enhance lift and moisture, likely producing more widespread precipitation. Also, expect an extended period of breezy easterly winds, esepcailly over the coastal waters and along the east coast beaches. Maximum temperature are forecast to drop slightly along the east coast metro region down into the mid 80s, a couple degrees cooler than normal for this time of year. MARINE...A tropical disturbance will continue to meander across North Florida and the northeast Gulf of Mexico enhancing coverage of showers and storms today and Monday. High pressure building over the eastern CONUS will produce east winds 20-30 KT over the Atlantic waters this evening through mid week. Waves will increase to 6 to 11 feet through this period for the Atlantic, creating dangerous conditions for small craft. && .PRELIMINARY POINT TEMPS/POPS... West Palm Beach 81 86 83 85 / 50 70 30 60 Fort Lauderdale 81 87 81 85 / 50 70 30 60 Miami 80 86 79 85 / 50 60 30 60 Naples 77 89 75 89 / 20 60 10 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...Small Craft Advisory from 11 PM this evening to 4 AM EDT Thursday for AMZ650-651-670-671. GM...None. && UPDATE...67/MT AVIATION...23/SK
Area Forecast Discussion
National Weather Service Melbourne FL
937 PM EDT Sun Oct 1 2017 .UPDATE... ...Flooding Impacts Expected to Continue across Brevard County Overnight... Convergent shower bands that brought extremely heavy rainfall to areas from Floridana Beach and Melbourne Beach to Palm Bay and West Melbourne has shifted northward gradually into late evening bringing heavy rainfall to central Brevard. A mesonet observation site in Floridana Beach has reported 10.68 inches of rain since midnight and still raining. Another mesonet site in Palm Bay has seen 9.13 inches since midnight with a West Melbourne site reporting 7.57 inches today. Flash Flood Warning has been reissued and covers portions of central and southern Brevard counties through 1130 pm. HRRR suggest strongest convection will shift south overnight while other guidance suggests Brevard and Indian River may remain the focus for Atlantic showers bands through the overnight hours. Radar trends show another primary rain band from the Cape eastward developing across the Atlantic that should eventually shift gradually south overnight but will continue threat for locally heavy flooding rainfall across central/srn Brevard counties to Indian River county later tonight. Have made adjustments upward to POPs/QPF in areas that will be focus for additional onshore moving showers through the night. Flood Warnings will likely be extended for portions of Brevard county into the overnight hours. && .AVIATION... Heavy showers moving onshore from the Atlantic will continue overnight with highest concentration of showers/isolated storms from KTIX-KVRB corridor into late tonight. MVFR CIGs and IFR VSBYs associated with convection. Additional showers will affect KDAB vcnty and KFPR-KSUA with activity diminishing as it moves inland toward KSFB-KMCO terminals. Some gradually drying across north FL into the afternoon should shift most shower chances south of KISM-KTIX line by afternoon. && .MARINE... Easterly winds increasing to around 20 knots will allow seas to build to 5-7 ft nearshore and up to 6-8 ft well offshore late tonight. No significant changes expected with late evening marine update. Small Craft will be in effect for all waters past 10 pm. && .PRELIMINARY POINT TEMPS/POPS... DAB 75 84 76 84 / 70 30 30 30 MCO 73 86 72 88 / 50 40 30 40 MLB 77 84 79 85 / 90 50 40 50 VRB 78 84 79 83 / 60 60 40 50 LEE 73 85 71 88 / 40 30 20 30 SFB 73 86 72 86 / 50 30 30 40 ORL 73 86 73 88 / 50 30 30 40 FPR 79 84 80 83 / 60 60 40 50 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...Small Craft Advisory until 4 PM EDT Thursday for Flagler Beach to Volusia-Brevard County Line 0-20 nm-Flagler Beach to Volusia-Brevard County Line 20-60 nm-Volusia-Brevard County Line to Sebastian Inlet 20-60 nm. Small Craft Advisory until 4 PM EDT Thursday for Sebastian Inlet to Jupiter Inlet 0-20 nm-Sebastian Inlet to Jupiter Inlet 20-60 nm-Volusia-Brevard County Line to Sebastian Inlet 0- 20 nm. && $$ Volkmer/Weitlich/Smith
Area Forecast Discussion
National Weather Service Pueblo CO
353 PM MDT Sun Oct 1 2017 .SHORT TERM...(This evening through Monday) Issued at 354 PM MDT Sun Oct 1 2017 ...Moderate snow accumulations possible for the central mountains... Upper level trof across the northern U.S. Rockies will continue to carve southward across UT/NV through Monday. Shortwaves ejecting out ahead of this system will bring rounds of precipitation to the central mountains with one wave moving through late this afternoon through this evening, and a second round expected on Monday. Lapse rates will remain steep in model soundings providing a convective element to snowfall and have seen some briefly heavy snowfall in web cams through the day across Fremont pass, though roads have remained generally wet. With snow levels dropping tonight to around 9-9.5 kft, snow may have a better time sticking to road surfaces this evening. Models then suggest a lull in the action by morning before another round moves in Monday afternoon. Snowfall totals are coming up to around 4-8 inches through Monday evening...with most falling north of Cottonwood Pass. With snow levels looking lower on Monday given CAA , this may result in some minor impacts to travel over the higher mountain passes like Fremont in the afternoon. Thus have put up a winter weather advisory for the higher peaks of the Sawatch and Mosquito ranges. All in all, looks like totals will fall on the lower end of the advisory spectrum. Elsewhere, dry and windy will be the main concern. Fortunately with wet fuels, critical fire weather conditions do not look to be of much concern. Still watching for the potential for an isolated severe to near severe storm along the eastern border...particularly Baca county. Latest HRRR run is developing thunderstorms across the far eastern counties where SPC Meso analysis is showing around 1000- 1500 j/kg of mixed layer cape and 40-50 kts of deep layer shear. While odds for a severe storm are better to the east in KS, just can`t rule it out entirely across far eastern CO so will carry some isolated pops out that way through early evening. Tonight a cold front will drop through the southeast plains. Cooler airmass then retreats slowly back northward on Monday as strong southwesterly winds spread back across the region. How far northward is the challenge and will have greatest impacts on temperatures. Latest 18z NAM lifts front back to the highway 50 corridor...while GFS is farther north with the front along the Palmer Divide. Overall went a little cooler in grids north of highway 50. Otherwise...plains looks largely dry again tomorrow...but will need to watch the far eastern border where the front lies up as there could be some higher cape out that way. -KT .LONG TERM...(Monday night through Sunday) Issued at 354 PM MDT Sun Oct 1 2017 Main longer term meteorological issues continue to be temperatures, pops and gusty winds at times. Initially, upper storm system is expected to provide accumulating snow over portions of the Central Mountains into Monday evening, therefore will allow recently issued Winter Weather Advisory to continue until 9 PM MDT Monday for these locations. Otherwise, latest longer term forecast model soundings, computer simulations and PV/precipitable water analysis suggest that the forecast district will be under southwesterly to zonal upper flow from Monday night into Thursday night. Models then diverge on their solutions from Friday into next weekend with the 01/12Z GFS solution depicting that basically dry zonal to northwesterly flow will prevail over the forecast district from later Friday into next weekend as closed upper low quickly moves east across North Dakota by Friday night. The 01/12Z ECMWF solution indicates a stronger upper system traversing Colorado from Friday into Friday night before system moves east of the CWA Saturday. In addition, north-northeasterly surface surges are anticipated from Monday night into Tuesday and then again from later Wednesday night into Thursday and these surges when combined with occasional upper disturbances will be capable of generating isolated to scattered pops, especially during the later Tuesday into Friday time-frame with driest conditions anticipated from Saturday afternoon into next Sunday. At this time, it appears that the highest potential for stronger gradient winds during the longer term should be realized from Monday night into Wednesday morning. Overall, generally above seasonal early October minimum temperatures are expected to continue over the majority of the forecast district during the longer term, while maximum temperatures are still projected to run within a category or so of climatological averages(although much warmer temperatures may be noted by next weekend if the GFS solution verifies...time will tell.) && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 354 PM MDT Sun Oct 1 2017 Gusty southwest winds with speeds of 20-30 kts will gradually decrease this evening...though KALS may see southerly winds around 10-15 kts through the night. This should keep fog from reforming across the San Luis Valley tonight. Meanwhile...a cold front will drop through the plains through this evening bringing a northerly wind shift at KCOS and KPUB. Some MVFR stratus will be possible towards 12z-16z at both terminals as winds shift around from the east to southeast. Any stratus that forms should erode by 17z as southwesterly winds spread back into the region. Should see gusts around 30 kts at KALS again tomorrow afternoon...with KPUB and KCOS staying southeast to easterly behind the front with gusts in the 10- 20 kt range at times. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 9 PM MDT Monday for COZ058-060. && $$
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
815 PM EDT Sun Oct 1 2017 .UPDATE... Most of the area saw scattered showers and an isolated storm today. The radar has quietened down quite a bit with only a few stray showers over the coastal waters. Latest HRRR model guidance is showing mostly dry conditions overnight. Will make some slight tweaks to the POPs to show diminishing rain chances through the night. All other parameters look good for now. Will send out updates zone shortly. && .AVIATION... All terminals are currently shower free and will remain VFR through the period. A stray shower will still be possible over the next few hours, so will keep VCSH at all terminals. Winds will remain out of the east overnight at 10 knots or less. A slight uptick in wind speeds can be expected tomorrow afternoon where gusts in the 15-20 knot range will be possible. No other aviation impacts expected. && .MARINE... Winds and seas will continue to increase from the east through the overnight period as the trough across the waters weakens and shifts off to the west, as a strong high pressure system builds into the region. The increasing pressure gradient across the waters will allow for a SCA to be raised across the offshore waters and northern near shore for tonight. This will likely need to be expanded for the Monday and beyond period as the strong ridge remains in place across the week. && .Preliminary Point Temps/PoPs... TPA 74 87 73 87 / 20 30 10 20 FMY 75 88 74 87 / 20 50 20 40 GIF 73 84 72 85 / 30 40 10 30 SRQ 74 89 73 87 / 20 40 10 30 BKV 75 86 71 87 / 20 30 10 20 SPG 76 85 74 87 / 20 40 10 30 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...None. Gulf waters...Small Craft Advisory until 11 AM EDT Monday for Coastal waters from Tarpon Springs to Suwannee River FL out 20 NM-Waters from Bonita Beach to Englewood FL out 20 to 60 NM-Waters from Englewood to Tarpon Springs FL out 20 to 60 NM-Waters from Tarpon Springs to Suwannee River FL out 20 to 60 NM. && $$ UPDATE/AVIATION/MARINE...74/Wynn UPPER AIR...63/Jillson DECISION SUPPORT...11/McKaughan
...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Monday) Issued at 309 PM CDT Sun Oct 1 2017 A broad upper level trough was located across the central Rockies and will remain stationary as a shorter wave-length trough along the OR and northern CA coast digs southeast into the base of the broad upper level trough across the four corners region by Monday afternoon. Later this afternoon and evening surface based thunderstorms will develop near a triple point across southwest NE, then back build along a surface dryline into western KS. Some of these storms may be severe as MLCAPES will reach 1500-2500 J/KG. The higher grid resolution models show a line of scattered thunderstorms developing across west central KS through the evening hours, then lifting northeast across north central KS during the early morning hours of Monday. The HRRR and WRF models show this line of storms weakening and becoming more isolated as they move east and northeast across north central KS, then across northeast KS. I kept the better chances for showers and perhaps a few elevated thunderstorms across the northwest counties Tonight. A few showers may reach the northeast counties during the morning hours of Monday. Southerly winds of 10 to 20 MPH will help keep overnight lows mild with mid to upper 60s. Monday, as the west-central conus trough amplifies the cold front will begin moving north and northwest across eastern NE into northwest KS. The surface dryline will retreat back west to the CO and KS border. After the elevated showers have ended during the morning hours across northeast KS, skies should become partly cloudy within the warm sector across the CWA. Surface based storms will develop along the surface front and dryline across west central and southwest KS during the late afternoon hours. Once again the surface pressure gradient will continue to be tight across central and south central KS due to a deepening lee surface low across southeast CO. Most areas will see southerly winds at 15 to 25 MPH with gusts to 35 to 40 MPH. The southwest counties may flirt with wind advisory criteria with sustained winds reaching 25 to 30 MPH and gusts around 40 to 45 MPH. If the the mid level clouds dissipate and mixing is a bit deeper than current forecasts, the next shift may want to consider the issuance of a wind advisory for portions of north central KS, but at this time it looks a bit too marginal. Highs will reach the mid 80s with some areas getting into the upper 80s. .LONG TERM...(Monday night through Sunday) Issued at 309 PM CDT Sun Oct 1 2017 Monday night, an amplified positively tilted trough is seen over the northwestern and north central US with a large ridge over the East. At the surface, a front located in western Kansas approaches central Kansas bringing in some PoPs to north central Kansas during the overnight hours. Mixed boundary layer winds will also persist overnight as this front moves east keeping wind gusts through the overnight hours especially near central Kansas. Tuesday, this front slowly moves into the CWA through the afternoon but soundings indicate a weak cap which would limit the severe potential, especially considering only about 30 knots of shear and ML CAPE near 1000 J/kg. Showers and storms are expected to develop Tuesday with the best chances for storms across the area Tuesday night into Wednesday morning. Models hang up this front across the area through most of the work week bringing chances for multiple rounds of precipitation across the area. PWATS increase through Wednesday when values from 1.5 to over 2 inches, almost double what is normal for the beginning of October. These values are primarily located over east central Kansas where there is the potential for multiple rounds of heavy rain which may lead to the flooding. This will need to be continued to be monitored as more details are worked out within the models. Still some discrepancy in the models for the weekend as the upper low exits the central US, but overall precipitation chances should be on the decrease Saturday night and Sunday. A temperature gradient exists on Tuesday with north central Kansas temperatures in the low 70s and low 80s seen for the rest of the area before the front makes its way through. From here, seasonable temperatures and cloudy skies persist through the work week. Skies will start to clear Saturday, with temperatures remaining in the 70s for the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 604 PM CDT Sun Oct 1 2017 Added LLWS back into the forecast as lowest parts of the boundary layer appear to decouple enough to warrant its inclusion around 1200ft agl. Atmosphere mixes out quickly again Monday morning and is once again breezy from the south. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Gargan LONG TERM...Heller AVIATION...67