Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/17/18

Area Forecast Discussion...UPDATED
National Weather Service Cheyenne WY
653 PM MDT Tue Oct 16 2018 .SHORT TERM...(This evening through Wednesday) Issued at 158 PM MDT Tue Oct 16 2018 Chamber of Commerce afternoon shaping up with surface ridge of high pressure and light winds. Temperatures were in the 40s and 50s. VIS satellite showed a few cirrus clouds spreading southward. Northwesterly flow aloft will back to southwesterly as a upper low over the southwest CONUS drifts northward and gradually weakens. Models keep any moisture with this system to our south, resulting in a dry forecast. Temperatures will moderate to seasonal normals. .LONG TERM...(Wednesday night through Tuesday) Issued at 158 PM MDT Tue Oct 16 2018 Weakening upper low over the central Rockies will be overtaken by progressive upper trough moving into the northern/central Plains Friday. A northwest-southeast oriented upper ridge will dominate the Rockies and Plains into early next week. Above average temperatures and dry conditions will continue. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 615 PM MDT Tue Oct 16 2018 minimal aviation impacts as VFR will prevail through the next 24 hours across the region. On caveat to monitor for would be patchy fog across the Nebraska Panhandle from 10-14Z. GFS and HRRR indicate high enough dewpoint depression spreads that would preclude fog development but the NAM has lower spreads that could support some patchy fog development. Will monitor trends for 06Z TAFs and if fog wording needs to be incorporated. Winds will be light and variable through the overnight and then become more steady from the southwest and south through Wednesday. && .FIRE WEATHER... Issued at 158 PM MDT Tue Oct 16 2018 Mild temperatures and light winds will limit fire potential through the period. Melting snow pack will help to keep humidity high and temperatures below normal. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...MJ LONG TERM...MJ AVIATION...JSA FIRE WEATHER...MJ
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
949 PM CDT Tue Oct 16 2018 .UPDATE... Quick update to account for latest radar trends. Weak isentropic ascent persisting across the area will result in periods of light drizzle or rain overnight with accumulations across the Hill Country expected to remain under one quarter inch. RAP analysis shows smaller disturbances lifting out of Mexico and into the Rio Grande Plains after midnight tonight in the south-southwest flow aloft that may help generate heavier shower activity across portions of Val Verde and Edwards, but expect this to remain west of the majority of the area. Not planning on any changes to the ongoing Flash Flood Watch configuration. In between drizzle/rain tonight, patchy fog development will be possible as the relaxing surface pressure gradient as resulted in light winds. Already seeing this development in the Hill Country and will have to monitor for expansion to the I-35 corridor and into the coastal plains. Otherwise, expect another chilly night with lows in the 40s to low 50s. && .PREV DISCUSSION... /ISSUED 725 PM CDT Tue Oct 16 2018/ AVIATION... MVFR conditions are expected this evening as the strong post frontal inversion lingers across South Central Texas with ceilings lowering to IFR along the I-35 corridor overnight and rising back to MVFR by mid-morning Wednesday. Lingering isentropic ascent may be able to produce some light drizzle or rain at all terminals through the period with high resolution guidance indicating the best window for AUS/SAT/SSF overnight and DRT after 14-15Z Wednesday. Expect northerly winds to persist in the 10-15 knot range. PREV DISCUSSION... /ISSUED 418 PM CDT Tue Oct 16 2018/ SHORT TERM (Tonight through Wednesday Night)... Afternoon radar imagery shows persistent rain continuing across portions of the I-35 corridor, Hill Country and southern Edwards Plateau. Hourly amounts according to radar and gauge data have been trending downward this afternoon across the Hill Country and I-35 corridor. However, any additional rainfall falling on saturated ground will instantly result in runoff. The latest round of hi-res models suggest the better chance for precipitation will contract and shift slightly northward this evening and overnight. This should place the higher rainfall chances along and north of a Del Rio to Fredericksburg to Burnet line. With models showing the stronger lift focused along the Rio Grande and southern Edwards Plateau, we should see the higher rainfall totals through tonight across Val Verde and Edwards county. However, as mentioned above, any additional rainfall over the Hill Country into west central Texas will result in runoff. On Wednesday, we should see a slight decrease in rainfall chances across most of the region as the mid-level ridge of high pressure builds westward across the northern Gulf of Mexico. The exception will be across portions of the Rio Grande plains and southern Edwards Plateau where mid-level shortwave activity will move northward from Coahuila Mexico into the above mentioned areas. Beginning Wednesday night, an area of higher moisture will begin to work northward from the western Gulf of Mexico into south Texas. The latest satellite precipitable water product shows values near 2.5" in the western Gulf. LONG TERM (Thursday through Tuesday)... The above mentioned surge of moisture from the Gulf of Mexico will continue to spread northward into south central Texas on Thursday. Models suggest precipitable water values will increase to near 2" across most of the region. We continue to see a good signal for rainfall in the model output and have opted to push rain chances much higher in the forecast for Thursday. Based on the ongoing flooding, along with another surge of moisture headed our way, we have opted to extend the Flash Flood Watch through early Thursday evening. If later model data remains consistent, we will likely have to expand the coverage of the watch to include counties along the I-35 corridor. For now, we will forecast an additional 1 to 2 inches with isolated totals near 4 inches across the watch area. The active weather pattern is likely to continue Friday and possibly well into Saturday as another cold front is expected to move in from the north. We will continue to mention rain chances in the forecast into early next week, with the better focus likely to remain out west along the Rio Grande. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 47 54 51 57 52 / 50 40 50 70 70 Austin Bergstrom Intl Airport 50 55 51 57 52 / 40 40 50 70 60 New Braunfels Muni Airport 47 55 51 58 53 / 30 40 60 70 70 Burnet Muni Airport 44 51 48 56 52 / 70 50 40 90 70 Del Rio Intl Airport 44 54 49 57 52 / 70 70 60 60 50 Georgetown Muni Airport 48 53 51 57 52 / 50 40 40 70 70 Hondo Muni Airport 49 57 52 59 54 / 50 50 70 100 80 San Marcos Muni Airport 48 55 51 57 53 / 40 40 60 70 70 La Grange - Fayette Regional 51 58 53 61 56 / 30 40 40 60 50 San Antonio Intl Airport 47 55 51 58 53 / 40 40 70 90 70 Stinson Muni Airport 49 56 52 59 54 / 30 40 70 90 70 && .EWX WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch through Thursday evening for Bandera-Blanco- Burnet-Edwards-Gillespie-Kendall-Kerr-Kinney-Llano-Maverick-Medina- Real-Uvalde-Val Verde-Zavala. && $$ Aviation...Huffman Short-Term/Long-Term...Oaks
Area Forecast Discussion
National Weather Service Gray ME
1031 PM EDT Tue Oct 16 2018 .SYNOPSIS... After a brief break tonight...the second in a series of strong cold fronts will arrive on Wednesday with another round of showers and gusty winds with the coldest air of the fall season arriving Wednesday night and Thursday with mountain snow showers continuing. High pressure arrives late Thursday and Thursday night with slackening winds and moderating temperatures through the end of the week. The next chance for rain showers will come Saturday ahead of another frontal system. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Update... Have updated the forecast based on current observations and latest mesoscale models. Chilly conditions will continue this evening with a window of radiation cooling continuing through about midnight over southern and central sections. In the north, clouds will continue to spill into the region shortly. Have dropped overnight low temperature forecast with many interior areas falling near or below the freezing mark. The increase in late night clouds may allow temperatures to climb later tonight. Lastly, the latest HRRR continues to bring the possibility of very light precipitation to northern areas after 07Z, some of this being snow shower activity over northern areas. Prev Disc... High Impact Weather Potential: Minimal. Pattern: Active pattern across the eastern United States early this afternoon with a sprawling longwave trough taking up residence over the eastern two thirds of NOAM with a longwave ridge centered along the west coast. For the time being...the NAO remains despite the depth of this will pull east through the near and short term forecast period. Within this trough are two significant shortwaves. The first is now departing the region to the east while the second will arrive on Wednesday. Thus... through the near term forecast period we find ourselves between these two features with a weak surface ridge axis building in from the west with a generally quiet night expected. Through this evening: Winds will continue to diminish to less than 10 mph this evening with temperatures falling fairly rapidly in the dry airmass under mostly clear skies...with most spots in the upper 30s/lower 40s by 8pm. Tonight: Ridge axis overhead this evening quickly moves east with flow beginning to back ahead of upstream shortwave that will dive into the Great Lakes through daybreak. Top down saturation will commence during the overnight hours with cloudiness gradually thickening and lowering. At the leading edge of a modest H8 Theta-E surge...recent high resolution HRRR runs have suggested a blossoming area of very light precipitation in the 9-12Z timeframe...with some support from the NAM nest and High res ARW window run. While it would be light...could see some snow in the mountains...with any precipitation to the south likely falling as light rain. Temperatures will fall quickly this evening...then level off and likely begin rising a bit overnight with lows in the 30s in all areas except southeastern NH and coastal ME. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... High Impact Weather Potential: Strengthening westerly winds Wednesday followed by accumulating snow in the mountains and favored upslope regions to the north Wednesday night. Pattern: Secondary shortwave arrives during the short term period with another northern stream...relatively moisture-starved cold front arriving during the day Wednesday followed by strong cold advection which will usher in the coldest air of the fall season thus far. Forecast concerns center largely on winds given the strength of this system...with attention paid to precipitation chances as well...particularly in the mountains where the pattern looks favorable for upslope snow showers. Wednesday: PWATs ahead of arriving secondary front are fairly meager /0.5-0.6 inch/...but more impressive will be along/immediately behind the front as 1000-700 mb lapse rates steepen with 50-100 J/kg of CAPE...cyclonic flow and support at the jet level likely supporting a convective line of showers that decays as it moves off the mountains and towards the coastal plain. In these can occasionally bring graupel to the surface given the cool airmass...however...wet bulb zero heights are still 3-5kft so this looks like it will be more of an exception than the rule. It will be a different story in the mountains where precipitation will increasingly become frozen towards evening with some light accumulations at elevation. Highs will reach the 50s along the coast and foothills...with 40s in the mountains. Temps in all areas will fall in the afternoon. Wind: Westerly winds strengthen ahead of the approaching front with a surge of cold advection immediately behind the front /combined with good mixing from lapse rates mentioned above/ potentially conspiring to bring 30-35 mph winds to the surface for a short time /~2 hr/ immediately after frontal passage. Wednesday Night: Robust cold advection continues through the night with strong cyclonic flow and residual low level moisture allowing upslope snow showers to continue in the mountains. Lift/moisture actually reach into the DGZ as temps fall expect snow showers to increasingly be able to accumulate overnight /as mentioned by previous forecaster/. Have painted 1-2 inches over the terrain and in northern Coos and far northern Oxford and Franklin counties. Further south... expect a few sprinkles/flurries in the evening...but overnight activity will increasingly be confined to the mountains /in line with froude number diagnostics/ as moisture thins and flow loses it/s cyclonic nature. Winds: Stronger winds will hold off until daytime mixing resumes on Thursday but 10-15 mph winds with gusts to around 25 mph will continue through the overnight. Temps: T8s fall below -10C /-3 sigma/ under strong cold advection...and despite mixing will push all areas into the 20s and 30s. Still have a few active zones from a frost/freeze perspective and while a frost is not likely given the winds...a hard freeze is not out of the question for these remaining zones. && .LONG TERM /THURSDAY THROUGH TUESDAY/... A big push of cold air moves into the region on Thursday. Temperatures aloft drop to well below normal with 700mb temps of -20C near record cold for this time of year. Accompanying the cold air will be a strong pressure gradient driving gusty northwesterly winds. Winds will begin to increase in the early morning hours of Thursday and continue through Thursday afternoon; a wind advisory will likely be needed with more scattered power outages possible. Strongest winds will be through the morning hours on Thursday when the mixing begins to allow the higher wind speeds to reach the surface and the strongest pressure gradient occurs. Have increased gusts a bit through this narrow time window with a few gusts to 40kts possible and widespread 25-5kt gusts across the lower elevations and the summits correspondingly higher. As the colder air moves into the region high temperatures on Thursday will hold in the 40s to upper 30s, nearly 15 degrees below normal. While the core of the cold air aloft will begin to shift northeastwards on Thursday night the decreasing pressure gradient will allow the winds to decouple by daybreak opening us up for good radiational cooling in the mountain valleys. While it may take until well after midnight to loose the winds, when we do temperatures will drop rapidly and thus have pushed lows a bit colder than much of the guidance. Even with a slight breeze this airmass will be enough to end the growing season for the remaining portion of the area and a Freeze warning will likely be needed for the coast. Friday temperature will moderate slightly as the cold air moves out of the region, with good agreement amongst various guidance stuck close to the consensus. For the weekend the next chance of precipitation moves into the area. It`s increasingly looking like the northern and southern stream will not phase allowing a weak disturbance to pass south of us early in the day on Saturday with a northern stream shortwave impacting the mountains through the weekend. Will see scattered showers across the entire region with highest PoP in the mountains. With temperatures marginal for snow, expect mainly rain for all but the highest elevations during the day with a transition to some light snow above 2000ft overnight Saturday into Sunday. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... Short Term... Summary: High pressure builds into the region tonight with a fast moving cold front arriving Wednesday afternoon...and moving south of the region Wednesday night. Restrictions: Expect VFR conditions to continue through Wednesday night. Could see some isolated restrictions in SHRA late Wednesday at HIE/LEB...and possibly AUG...but not likely south and east of this. Winds: Northwesterly winds will continue to gradually weaken through this evening and tonight as high pressure arrives from the west. On Wednesday...westerly winds strengthen to 15G25kts ahead of the cold front before shifting northwesterly Wednesday night and continuing 15G25kts through the night. LLWS: No LLWS expected through the period as the low levels remain well-mixed given the strong wind field. Lightning: No lightning expected through Wednesday night. Long Term...VFR conditions will continue through most of the extended. Strong cold advection will bring gusty northwesterly winds for Wednesday night into Thursday morning. Another system will bring a chance for showers to the entire area on Saturday with highest Pop in the mountains where MVFR and overnight snow showers are likely on Saturday night. && .MARINE... Short Term...Winds/waves have subsided a bit from this morning...but SCA conditions will continue outside the bays through tonight before waves strengthen ahead of our next system late Wednesday with a Gale watch issued beginning late Wednesday and continuing into the long term forecast period below. Long Term...Cold air will move into the region overnight Wednesday into Thursday. The cold air and tight pressure gradient will result in strong northwesterly winds with gusts to Gale and a Gale Watch has been issued. Winds will decrease as high pressure builds in on Friday before again increasing to gusting 25-30kts will SCA likely all weekend. && .EQUIPMENT... KGYX radar outage with parts on order this afternoon. Expect to be back up around midday Thursday. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Gale Watch from Wednesday evening through Thursday afternoon for ANZ150>154. && $$ JC
Area Forecast Discussion
National Weather Service Miami FL
803 PM EDT Tue Oct 16 2018 .AVIATION... Showers continue to push ashore from the Atlantic and that activity is expected to continue overnight into the morning. Convective coverage should shift as the day goes on inland and to the west towards APF by afternoon. Easterly flow with some gusts to 20 kts can be expected again. && .PREV DISCUSSION... /issued 754 PM EDT Tue Oct 16 2018/ UPDATE... Current radar shows isolated shower activity along the Atlantic coast moving quickly westward due to persistent easterly flow. The latest observations indicate around 10 mph along the Atlantic beaches. The HRRR and the WRF prog an increase in shower coverage over Miami- Dade and Broward counties during the next several hours. Thus, have increased PoPs in the latest update to reflect chance of showers and slight chance of thunderstorm in this general area overnight. Otherwise, all other variables appeared on track. PREV DISCUSSION... /issued 416 PM EDT Tue Oct 16 2018/ DISCUSSION... Latest WPC analysis depicts an elongated 1022 mb surface high stretching from the mid-Atlantic to near Bermuda. A stationary front can also be noted from the Carolinas down towards the western Gulf. Clockwise motion around the aforementioned high has allowed for persistent breezy easterly flow across Southern Florida. Observed winds speeds this afternoon have generally been sustained 10 to 15 mph, gusting occasionally to 20 mph. This flow regime has led to the highest maximum temperatures to develop along the western interior, in the low 90s. Mainly upper 80s have been reported along the east coast where the greatest influence from the Atlantic waters exist. Satellite derived PWAT indicates relatively dry air, with values only around 1.6". Showers have been far and in between today as mostly dry conditions have prevailed. Tonight, small scale models including the HRRR and Hi- Res WRF show shower development, mainly over coastal areas of Miami-Dade and Broward counties as a weak impulse of enhanced moisture moves over the area from the Bahamas. Minimum temperatures will range from near 80 degrees along the east coast metro to mid 70s along the Gulf coast. These values are around 3 to 5 degrees above normal for this time of year. Wednesday through this weekend: Both the GFS and ECMWF prog a robust cell of high pressure to migrate west from its current position and meander over the the Florida peninsula through at least Friday. This will again lead to deep layer easterly flow, partly cloudy skies, and mainly dry conditions. Temperatures are generally forecast in the upper 80s along the east coast metro and low 90s inland and near the Gulf coast. Record temperatures may be just a few degrees shy of being tied, esepcailly on Wednesday, at Naples and West Palm Beach. Long range models begin to drop a low pressure trough down by this weekend into early next week. Though it may not make it all the way to our CWA, increasing moisture and instability ahead of the front will at least help to enhance our precipitation chances as it nears. MARINE... High pressure centered east of the waters will continue to provide moderate easterly wind through the week, with Atlantic winds occasionally increasing to around Small Craft Advisory levels, especially mid to late week. Seas will be 4 feet or less. Aside from isolated passing showers, mainly in the Atlantic, dry weather will prevail. BEACH FORECAST... A high risk for rip currents will likely develop early Wednesday through the rest of the week for the Atlantic beaches due to persistent easterly winds. Swimmers should exercise extreme caution given these expected conditions. && .PRELIMINARY POINT TEMPS/POPS... West Palm Beach 78 89 77 88 / 20 20 20 20 Fort Lauderdale 80 88 80 87 / 30 20 20 20 Miami 78 89 78 88 / 30 20 20 20 Naples 75 91 74 90 / 10 30 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. && AVIATION...02/RAG UPDATE...11/HV DISCUSSION...27/JT MARINE...27/JT AVIATION...02/RAG BEACH FORECAST...27/JT