Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/02/19


Area Forecast Discussion
National Weather Service Denver/Boulder CO
833 PM MDT Thu Aug 1 2019 .UPDATE... Issued at 833 PM MDT Thu Aug 1 2019 The intensity of thunderstorms has decreased by the coverage of storms remains high on the eastern plains with scattered thunderstorms still generating over Weld County and the northern Front Range foothills. The Severe Thunderstorm Watch has been cancelled, but areas covered by the Flash Flood Watch are still receiving light to moderate rainfall, some of which is falling on areas that received heavy rain earlier this evening. Will let the Flash Flood Watch continue. A very moist airmass remains in place across northeast Colorado with dew points in the lower to mid 60s. Precipitable water values are also still in the 1.00 to 1.25 inch range. Sub-tropical moisture at mid levels will continue moving over central Colorado and out over northeast Colorado through the night, keeping shower activity going for a few more hours. After midnight, the airmass should stabilize with drier and more subsident air expected to move in from northwest Colorado and south-central Wyoming. Quick look at the evening models shows a much drier day tomorrow with increasing northerly flow at mid and upper levels, due to the center of the upper level ridge sliding a little bit to our west and southwest. As the shower activity on the plains dissipates later tonight, the Flash Flood Watch will be allowed to expire. && .SHORT TERM...(This evening through Friday) Issued at 245 PM MDT Thu Aug 1 2019 Plume of monsoonal moisture is pushing east across the forecast area, with showers and storms becoming more numerous. Convection has been a little slow to develop due to the abundant sky cover over the high country. Strongest convection is now just developing over the plains east of I-25 as expected, thanks to more sunshine there. This evolution will continue through the evening, with the strongest storms developing and spreading east across the plains. Convection will become more widespread there with the upslope flow, moderate to high instability of MLCAPE near 2000 J/kg, and a passing upper level disturbance bringing weak but deep lift. As the low level jet strengthens this evening, we expect further development into a Mesoscale Convective System (MCS) on the eastern plains. Locally heavy rainfall and flash flooding threat will continue there until about 10 PM - Midnight...see Hydrology section below for more details. A couple severe storms expected too, with wet microbursts and strong winds up to 60-70 mph possible. Along the Front Range Foothills and I-25 Corridor, the intensity of storms will be limited by instability. Brief heavy rain can still be expected through the mid evening hours as precipitable water values are quite high, near 1.25 inches. Storms will be moving along at 15-20 mph here, so generally minor if any flooding expected from a stronger storm moving through a burn scar or urban area. For later tonight, skies will generally clear from west to east as the short wave passes and weak subsidence builds in. On Friday, the latest data indicates a cap to remain in place across most of the plains, so we`ll reduce/remove chance of storms over all of the plains. Main chance of afternoon storms would stick to the higher elevations and mountains west and southwest of Denver where cap should be broken thanks to elevated heating source. Temperatures near normal. .LONG TERM...(Friday night through Thursday) Issued at 329 PM MDT Thu Aug 1 2019 The upper ridge will be centered right around the four corners Friday night through Sunday night. The flow aloft will be light and west-northwesterly. The QG Omega fields show subsidence in the synoptic scale for much of the CWA Friday night. There is neutral energy progged Saturday through Sunday, with a tad of weak upward energy Sunday night. The low level winds look to be easterly Friday evening, with normal drainage patterns kicking in overnight. Decent east-southeasterlies are progged Saturday and again Sunday with normal drainage patterns Saturday and Sunday nights. Concerning moisture, precipitable water values are mostly progged below 1.00 inch over much of the CWA Friday night into Sunday morning. They come up a tad Sunday and Sunday night. The surface dew points stay mainly in the 50s F over the plains for the five periods, with a few lowers 60s along the eastern border. There is fairly decent CAPE around over the mountains and foothills Friday evening. For late day Saturday, the best CAPE is over the southwestern and far eastern CWA. The decent CAPE on Sunday is relegated to the high country. The QPF Fields show measurable rainfall mainly over the mountains and foothills Friday evening, late day Saturday and late day Sunday. For pops, will go with "scattered"s over the mountains and foothills Friday evening. Same for late day Saturday with the additions of the Palmer Ridge. For late day Sunday, with go with "scattered"s for the western 3/5ths of the CWA. For temperatures, Saturday`s highs are 1-2 C warmer than Friday`s highs. Sunday`s highs are about 2 C warmer than Saturday`s. For the later days, Monday through Thursday, models keep the center of the upper ridge southwest of Colorado through Tuesday, then due south of the state Wednesday and Thursday. The ridge axis is over western Colorado on up into Canada. The mid and upper level moisture is progged to stick around and precipitable water values are generally above 1.00 inch over the plains all four days. Temperatures stay right at seasonal normals. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 833 PM MDT Thu Aug 1 2019 A few lingering showers may still move across the Denver area through about 10 PM. After that skies should begin to clear as showers dissipate. There is a chance that areas of stratus or fog will develop due to the airmass being so wet. The HRRR brings fog to KDEN and the South Platte River Valley between 3 AM and 8 AM. Surface winds are expected to be sioutherly or southwesterly which would tend to be drying on the local scale. Will mention some fog in the vicinity for few morning hours with the next set of forecasts. No other aviation impacts are expected through tomorrow afternoon as the winds turn northerly and drier, more stable air moves into the region. && .HYDROLOGY... Issued at 245 PM MDT Thu Aug 1 2019 All satellite imagery shows the monsoonal moisture plume shifting east across the forecast area, coinciding with peak heating and destabilization. Strongest storms have developed just east of the I-25 Corridor, where bulk of instability exists and cap has been broken. The main threat for more significant rainfall and flash flooding will remain in that area this evening as favorable parameters on the eastern plains include; lower to mid 60s surface dewpoints, increasing easterly low level jet into the evening, high PWs with values of 1.3-1.5 inches, deep warm cloud depth of 6,000-9,000 feet, and the expected development of an Mesoscale Convective System (MCS). Storm totals of 2 to 4 inches are possible from the stronger storms, with rainfall rates of 1 to 2 inches in about 30 minutes. Flash flooding will be possible especially over locations that have received heavy rainfall over the past couple of days, or those areas that see training storms on the edge of the expected MCS. The Flash Flood Watch for a good portion of the northeast Colorado plains from 4 PM to Midnight looks on track. && .BOU WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch until midnight MDT tonight for COZ042-044>046- 048-049. && $$ UPDATE...Dankers SHORT TERM...Barjenbruch LONG TERM...RJK AVIATION...Dankers HYDROLOGY...Barjenbruch
Area Forecast Discussion
National Weather Service Goodland KS
920 PM MDT Thu Aug 1 2019 .UPDATE... Issued at 917 PM MDT Thu Aug 1 2019 The window for severe weather has closed for today as the environment has stabilized enough to cap off any CAPE. Am expecting the light/moderate rainfall to slowly move east through the night. As it moves east it will shift more toward the central part of the forecast area where the LLJ nose will be that will also be moving east. Current forecast has chances for rainfall lingering past sunrise. Am thinking the storm activity should be east of the forecast area by 4 AM or 5 AM MT. && .SHORT TERM...(Through Tonight) Issued at 135 PM MDT Thu Aug 1 2019 Light W-WNW flow aloft persists over the region, on the N-NNE periphery of an upper level ridge. Pervasive low stratus, light northerly flow, and transient elevated showers throughout the morning have profoundly attenuated insolation across the Tri-State area. Given significant convective inhibition (100-300 J/kg CINH) and weak/limited forcing confined to shallow low-level convergence, convection is not anticipated to initiate over the Tri-State area this afternoon. Convection developing along the Colorado Front Range between 19-22Z is anticipated to gradually propagate downstream into eastern Colorado late this afternoon (00-03Z) and into western Kansas this evening (03-06Z) -- as indicated by simulated reflectivity forecasts via multiple runs of the HRRR and NAM NEST. With weak low/mid-level flow, modest deep layer shear, an increasingly capped airmass east of the CO/KS border -- any severe weather potential is expected to be confined to eastern Colorado between 6-10 pm MDT. Loss of insolation and an increasingly hostile thermodynamic environment with eastern extent will induce a weakening trend thereafter -- though one or several MCVs emanating from upstream convection may be sufficient for activity to persist into western KS late this evening and tonight, where locally heavy rainfall will remain a possibility. .LONG TERM...(Friday through Thursday) Issued at 1255 PM MDT Thu Aug 1 2019 At the start of the period, an upper ridge spans the western half of the country with its high centered over New Mexico. The tri- state region remains under northwest flow on the eastern side of the ridge. A surface low persists to the east of the area on Friday as the upper ridge regresses, with the anticyclone now centering over the Four Corners. The disturbance from the previous day continues to rotate around the ridge on its eastern side, generating shower and thunderstorm chances in the morning (mainly for the eastern part of the region). With these chances will come increased cloud cover. There will likely be a lull in precipitation midday followed by an additional opportunity for showers and storms in the afternoon and evening behind the low as daytime heating occurs. No severe weather is anticipated at this time. Despite the potential for a few showers lingering into Saturday morning to the east, dry weather is anticipated during the weekend as surface high pressure slides over the region. The upper ridge prevails over the southwestern portion of the CONUS through Thursday with little change to the pattern. North to northwest flow continues aloft next week as multiple shortwaves move through the periphery of the ridge. This results in daily opportunities for thunderstorms, mainly in the afternoon and evening hours, Monday through Thursday. Widespread rainfall is not currently anticipated. High temperatures in the 80s are forecast Friday and Saturday, followed by a warming trend with highs in the low 90s region-wide by Monday. Temperatures remain in the upper 80s to low 90s midweek. Low temperatures range in the upper 50s to upper 60s throughout the period. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 549 PM MDT Thu Aug 1 2019 VFR to IFR conditions forecast for the TAFs. Main focus will be the storm activity moving in from the west this evening/overnight. By the time the storms move near KGLD, the threat for severe weather should be low. Heavy rainfall and some gusty winds may still be possible though. Confidence is lower as to what the storm coverage will be for KMCK. Current storm motion has the activity moving northeast by 6z, which may direct any storm activity toward KMCK. Confidence is moderate that storms will move over KMCK. No severe weather is expected at this time for the site. After the storm activity is either diminished or moved east, stratus will move in from the northeast. KGLD should be west of the IFR ceilings. The ceilings will gradually lift through tomorrow morning. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...VINCENT LONG TERM...JBH AVIATION...JTL
Area Forecast Discussion
National Weather Service Key West FL
1023 PM EDT Thu Aug 1 2019 .DISCUSSION... Well above normal shower and thunderstorm coverage will continue through Saturday, then diminish on Sunday. Normal coverage is expected from Monday through next Thursday. .SHORT TERM... The axis of a tropical wave was analyzed this evening along 83W. The 00z KEY sounding observed a record-breaking (for the date) Precipitable Water value of 2.53", indicating deep tropical moisture. The 00z MFL sounding PW value of 2.07" is near the 80th percentile for this date. So the abundance of shower and thunderstorm activity this evening is not surprising. This most concentrated area of thunderstorms originated from afternoon convection which emerged off the north coast of Cuba. This area continues to spread north through the Straits of Florida, with radar showing numerous outflow boundaries upon which to focus additional convection. The last few runs of the HRRR have been showing numerous showers and thunderstorms for the Lower and Middle Keys during the late evening and overnight hours, eventually reaching the Upper Keys in the hours before sunrise. Have given PoPs a slight nudge upward from 60 to 70 percent for the rest of tonight. The tropical wave will lift northward into the far eastern Gulf on Friday. The 12z and 18z GFS ensemble means shows a bullseye of negative MSLP anomalies near the Dry Tortugas at sunrise Friday, lifting north to near Tampa Bay by mid-day Saturday. Over the Keys, this movement will support a deepening and strengthening of southerly flow through at least Friday night. PW values will remain well over 2", and numerous outflow boundaries will act to focus convection. With southerly flow peaking on Friday night, this should also spread PM Cuban convection north across the Straits, possibly reaching the Keys later Friday night. Surface pressures rise modestly over the Keys later Saturday, with the more unsettled weather starting to lift off to our north. On Sunday, the subtropical ridge axis over the Atlantic will start to expand across the Keys and South Florida. The air mass will remain quite moist, but this evolution of the pattern should provide a transition day during which our shower and thunderstorm coverage starts to diminish back in the direction of climatology. As we move from July into August, the climatological 12-hour PoP at Key West rises from near 25 percent to near 30 percent. && .MARINE... The main risk to mariners through at least Saturday will be an abundance of showers and thunderstorms. Therefore, winds will ultimately be gusty and erratic at times under the influence of numerous convective outflow boundaries. In the broader picture, prevailing moderate easterly breezes this evening will become more southerly on Friday and Friday night, as a weak low center drifts north from near the Dry Tortugas on Friday morning to near Tampa Bay by mid-day Saturday. Ridging will reestablish itself across the Florida Peninsula through the first half of next week, resulting in a return to gentle east to southeast breezes and scattered convection. && .COASTAL FLOODING... Tides have been running higher than normal over the past couple of days, with anomalies around 3/4 of a foot above the astronomical predictions. Thursday morning`s higher high tide topped at 3.03 ft at 10:48 am at the Key West Tide Gauge. In addition, a Key West meteorologist observed a number of low lying streets and parking lots under water around that time. Coastal Flood Statements will likely be required daily through at least Saturday and possibly Sunday, with the peaks occurring during high tide from the late morning into early afternoon. && .AVIATION... VFR conditions will prevail at both EYW and MTH terminals. Sub VFR conditions may occur for brief periods during the night and early morning hours as scattered showers and isolated thunderstorms move through the area. Winds east to east southeast at 10 knots. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...Haner Aviation/Nowcasts....SDR Data Collection......DR Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest
Area Forecast Discussion
National Weather Service Pueblo CO
636 PM MDT Thu Aug 1 2019 .UPDATE... Issued at 633 PM MDT Thu Aug 1 2019 Updated forecast products based on current radar trends and HRRR guidance. Best chance of pops will be greater EL Paso county region next hour or so and northeast section of SE CO plains this evening. Mtns will also continue to be showery. && .SHORT TERM...(This evening through Friday) Issued at 341 PM MDT Thu Aug 1 2019 A shortwave trough and its associated cold front will continue to impact the region this evening. The shortwave trough continue scattered to numerous thunderstorms over the mountains and over the Plains, but the main severe risk will be over norther El Paso County and Kiowa county. What is anticipated to occur is that thunderstorms develop over the Rampart Range and the Palmer Divide and will propagate into a more favorable environment for thunderstorm development, then turn into a line of thunderstorms that will spread across eastern Colorado. The CAPE values over northern El Paso County are around 1000 J/kg with 0-6km bulk shear values around 30 kts. The main impacts will be hail around 1 inch, wind gusts up to 60 mph, locally heavy rain, and frequent cloud to ground lightning. The main convective complex is expected to leave WFO Pueblo`s forecast region, only to return later tonight over Kiowa County. By that time, the line of thunderstorms will be mature and the main risk will be gusty outflow thunderstorm winds, with magnitudes up to 70 mph. There is the potential for flash flooding over the Spring, Junkins, and Hayden Pass burn scars since mountain thunderstorms are expected. Thunderstorms will dissipate by around midnight, leaving dry conditions during the overnight hours over the majority of the area. There may be some lingering showers and thunderstorms over the eastern San Juans during the overnight hours, and low clouds are anticipated over the eastern plains. Predominantly northerly flow will be in place over the region tomorrow afternoon over the eastern plains, which takes away from the normal upslope component of diurnal heating, so thunderstorms are not anticipated to be as frequent tomorrow afternoon. The southern Sangre de Cristo Mountains appear to be the QPF hot spot for tomorrow afternoon, since the northerly component winds are pointed up the slopes of the mountains. The plains seem to be too stable for thunderstorm development tomorrow afternoon. the main flash flooding risk will be over the Spring burn scar. High temperatures tomorrow will cool off due to the cold front passage, so expect temperatures in the low 90s over the plains, the low 80s over the mountain valleys and the 50s to 70s over the mountains. .LONG TERM...(Friday night through Thursday) Issued at 341 PM MDT Thu Aug 1 2019 Seeing the monsoonal moisture in full swing through the medium range period leading to a healthy dose of diurnally driven showers and storms, mostly Front Range westward early next week. Mid-level ridging is expected to drift towards the west a bit this weekend pushing the better chances for showers and storms into the High Country and not much farther east into the plains. As the high pressure then begins to drift more to our south and an approaching mid-level trough enters from the north we should see a quick uptick in monsoonal moisture and more widespread showers and storms by late in the period. Highs through the week are expected to be in the 90s across the plains and upper 70s to mid 80s in the high valleys. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 341 PM MDT Thu Aug 1 2019 VFR conditions are anticipated over KALS, KCOS, and KPUB throughout the forecast period. Northerly winds are expected after after a cold front passes by this evening. Low clouds will form during the overnight hours over KCOS and KPUB, but they aren`t expected to be low enough to lower flight categories. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HODANISH SHORT TERM...SKELLY LONG TERM...HEAVENER AVIATION...SKELLY
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
812 PM EDT Thu Aug 1 2019 .UPDATE... Convection winding down across the region, but other thunderstorms and light rain are moving north across the eastern half of the Florida peninsula at this time. Most of this rain will stay out of our area and/or weaken as it moves into eastern Polk and Sumter counties over the next few hours since the atmosphere has already been pretty well worked over from the earlier convection. Then for the remainder of the night skies will be partly to mostly cloudy and we`ll begin to see a few more showers and possibly a thunderstorm move northeast into the region as the deep moisture associated with the tropical wave move northwestward. This moisture will overspread the entire area Friday leading to abundant clouds and numerous showers and scattered thunderstorms. Overall the present forecast looks on track and only some slight adjustments to current conditions needed. && .AVIATION... Convection will continue to wind down this evening, but not completely go away overnight. Then during Friday more showers and thunderstorms will move into the region and become numerous in the afternoon and these could cause some MVFR/local IFR conditions along with gusty winds up to around 30 knots. Otherwise VFR conditions are expected with northeast to east winds at 4-7 knots tonight becoming east to southeast at 5 to 10 knots Friday morning. && .MARINE... Main concern for the next couple of days will be the potential for numerous showers and thunderstorms as a weak area of low pressure is expected to develop in the southeast Gulf of Mexico later tonight through Friday. This low will enhance the amount of convection over the eastern Gulf waters and increase the easterly winds to near 15 knots at times. Winds shift to the southwest to west over the weekend as this weak low pressure shifts northeastward back into the Atlantic Ocean. && .Prev Discussion... /issued 1152 AM EDT Thu Aug 1 2019/ SYNOPSIS... 16Z water vapor and H4 RAP analysis showing a complex mid/upper level pattern evolving over the Florida peninsula/eastern Gulf. The region sits within a zone of mid/upper level SW flow between a well-defined upper low spinning over the north-central Gulf of Mexico and a large ridge of the eastern Atlantic to the east and northeast of Florida. To complicate matters, a lower to middle level disturbance is currently located over the Bahamas/Florida Straits/south Florida that is slowly rounding the base of the upper ridge. The unseasonably deep trough into the central Gulf and this migrating disturbance will prevent a typical sea-breeze convection type pattern for the next couple of days. Therefore, the rainfall pattern will be more "messy"...with showers/storms being rather numerous, but with a less defined spatial/temporal pattern. However, the potential for heavy rainfall is certainly there, especially south of the I-4 corridor, and this is a concern given the saturated state of soils and elevated river levels across much of the region. The greatest coverage of rain and potential for localized flooding will be Friday, so will be monitoring today`s thunderstorm activity and where the heaviest rainfall totals occur in anticipation of potential flood watches. SHORT TERM (Rest of Today through Friday)... As mentioned in the synopsis...the patten the next 48 to 72 hours will not be one characteristic of "summer" in Florida. The normal pattern dominated by sea breeze / synoptic flow interaction to produce scattered thunderstorms will be overwhelmed by larger scale processes and result in a broader temporal and spatial pattern of numerous shower/storms. Basically rain chances will be high for passing bands of showers, although attempting to put much detail into the forecast for exactly where the forcing mechanisms will be located is tough to do. Essentially, large scale processes to promote lift and resulting convection will be increasing across the region through the rest of today, along with precipitable water values continuing to rise. PW values are forecasts by many of the global guidance members to exceed 2.25" on Friday, as deep moisture is advected northward within the large scale flow. In addition, the weak disturbance approaching from the Bahamas/Florida straits is likely to result in a weak area of low pressure in the SE Gulf by Friday morning. Additional forcing for ascent on the north/east side of this low is likely to make Friday a rather wet day...potential for all of the region, but most likely for areas along and south of the I-4 corridor. The potential for widespread heavy rainfall amounts 1-2"+ will certainly be higher to the south of the I-4 corridor based on the current forecast synoptic setup. LONG TERM... Large scale forcing will continue to be an impact on the region from the deep troughing in the Gulf into Saturday. However, the weak low in the SW Gulf is expected to quickly eject northward back into the Atlantic. This process will shift our winds out of the southwest. With the southwest winds, the greatest rain chances during the morning will be along the west coast...with most of the rainfall shifting well inland by later in the day. Sunday at this point is looking like a very similar day in terms of overall weather impacts and pattern, although the upper trough will show signs of deamplifying. The early to middle portion of the upcoming work week looks to return the forecast to one more typical for early August, with the subtropical ridge back into control of the area...and the forecast dominated by mainly afternoon and evening scattered storms. FIRE WEATHER... Abundant moisture and high rain chances will prevent any significant fire weather concerns through the upcoming weekend. No significant visibility impacts are expected due to fog or smoke through the upcoming weekend. && .Preliminary Point Temps/PoPs... TPA 75 86 74 89 / 20 80 50 50 FMY 75 86 75 89 / 30 80 50 60 GIF 75 86 73 90 / 30 80 50 70 SRQ 75 87 73 89 / 20 80 50 60 BKV 73 86 72 89 / 40 80 50 60 SPG 75 87 74 89 / 20 80 50 50 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...None. Gulf waters...None. && $$ UPDATE/AVIATION/MARINE...Close PREV DISCUSSION...Mroczka UPPER AIR...Fleming DECISION SUPPORT...Hubbard