Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/30/20

Area Forecast Discussion
National Weather Service Caribou ME
1154 PM EDT Wed Jul 29 2020 .SYNOPSIS... A trough of low pressure will slowly move across the north through Friday. High pressure will build in from the west on Saturday and crest over the area Sunday. A trough of low pressure will cross the region on Monday. && .NEAR TERM /THROUGH THURSDAY/... 1153 pm Update... Adjustments were made to increase pops overnight, mainly North of the Katahdin region. Rather vigorous short wave approaching from Quebec will track east across Northern Maine around daybreak. Showers already pushing into Northern and Western Maine per latest radar reflectivity imagery, with some lightning strikes already indicated per lightning detection. Latest runs of the HRRR seems to be handling things well at this hour, and does shows activity moving across Northern Maine by daybreak. Based on this, have increased QPF in the 06z-12z for the North. Prev discussion... Showers and thunderstorms will continue into the day Thursday with another shortwave rounding the upper level low and providing lift. Mid-level lapse rates will be around or above 6 degrees C/km and more favorable for ascent. An isolated severe weather threat may exist across southern and eastern parts of the forecast area where bulk shear around 30 to 40 knots will overlap with the greatest chances for SBCAPE of at least 1000 j/kg according to the 12z HREF. The threat will be dependent on cloud cover and how much heating occurs. Gusty winds would be the primary concern. High temperatures will be in the 80s across the southern half of the forecast area, with 70s across the north where thicker cloud cover is anticipated. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... A trough of low pressure will be to our north Thursday night as very weak surface low pressure drifts off to the northeast. Some showers may remain across the north in the evening with any showers dissipating overnight. Northern areas will remain mostly cloudy with partial clearing Downeast. The upper trough will remain nearby to the north on Friday as very weak surface low pressure stays just to our northeast. With moisture over the area, mainly the north, and low heights, some scattered showers and spotty thunderstorms may be over the area, mostly central and northern spots. The upper trough will lift away to the northeast Friday night followed by upper level ridging and surface high pressure beginning to build in on Saturday. A weak trailing shortwave may bring an isolated shower or thunderstorm on Saturday across the north. Otherwise, Saturday will turn out partly cloudy and warm. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... Upper level ridging across the area will bring a mostly clear night Saturday night with weak surface high pressure to the south. The weak flow and clear sky will likely allow some patchy valley fog to form late. Sunday will begin mostly sunny. Some stray thunderstorms are possible during the midday and afternoon, mainly across far western areas, as a bit of moisture begins advancing north ahead of a new trough approaching from the Great Lakes. Clouds will increase late Sunday into Sunday night as the trough and frontal system approach. Current guidance is showing potentially a lot of moisture with this system but lifts most of that moisture to our northwest ahead of the front. A cold front will then press across the area Monday bringing some showers and isolated thunderstorms across the region, mostly over the north. High pressure will then build in from the west Monday night into Tuesday bringing clearing and some lower humidity to the region. A weak trough lifting into the region Wednesday may bring another chance for some showers with the best chances for any showers again favoring far western parts of the region. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... NEAR TERM: VFR for Downeast terminals next 24 hours. For PQI terminal and north expected MVFR cigs to move in shortly after daybreak. Cannot rule out IFR cigs at FVE after 09z. Showers and possible thunderstorms expected overnight across the north and again during the afternoon tomorrow with localized IFR restrictions. SHORT TERM: Thursday night: MVFR north VFR Downeast, but locally IFR in any fog late at night. Light NW wind. Friday: VFR. Light NW wind. Friday night: VFR. Light NW wind. Saturday: VFR. Light W wind. Saturday night: VFR, but locally IFR in patchy fog late. Light W wind. Sunday: VFR. Light S wind. Sunday night: MVFR lowering to IFR. S wind. Monday: IFR. S wind, becoming N over the north. Showers. && .MARINE... NEAR TERM: Winds and seas will remain below small craft criteria through Thursday. Patchy fog is possible with visibility below 3 NM, mainly after midnight tonight. SHORT TERM: Winds and seas are expected to be below SCA through the coming weekend. Humid air will likely result in fog at times across the waters, especially late at night and early mornings. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...None. && $$ Near Term...Duda/MStrauser Short Term...Bloomer Long Term...Bloomer Aviation...Duda/MStrauser/Bloomer Marine...Duda/MStrauser/Bloomer
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
959 PM CDT Wed Jul 29 2020 .UPDATE... Issued at 907 PM CDT Wed Jul 29 2020 Scattered thunderstorms will move across southeastern Missouri and west-central Illinois overnight, with more stratiform showers blanketing most of eastern and central Missouri. Several vorticity maxima are passing around a mid-level trough, which continues to support the showers and thunderstorms across the area. Anomalously high PWATs of over 2 inches across Missouri will lead to efficient rainfall rates where convection develops. Abundant moisture, higher MUCAPE, and low-level convergence overlap in southeastern Missouri. High rainfall rates in thunderstorms could trigger flash flooding, warranting the continuation of the Flash Flood Watch for the extreme southern CWA. MRB && .SHORT TERM... (Through Late Thursday Afternoon) Issued at 329 PM CDT Wed Jul 29 2020 A short wave trough over the eastern Plains has turned the low level flow around to the southwest. Scattered showers and thunderstorms are developing due to low level moisture convergence associated with this southwesterly flow. As the mid-upper short wave digs east- southeast tonight, the eastern lobe of low level vorticity associated with the system is expected to drift into central/south central Missouri. The 850mb gradient tightens substantially through the evening as this occurs which ramps up the low level jet and subsequently the moisture convergence. While most, if not all of the area should see some rainfall tonight, short range guidance targets northern Arkansas and south central into southeast Missouri with the strongest low level moisture convergence. I`m inclined to think the models which spread heavy QPF up into east central and northeast Missouri tonight are overdone. With mass fields showing the stronger forcing further south, I think the highest rainfall amounts will generally be across the eastern Ozarks, along and south of I-44 much like what the RAP is depicting. Ensemble guidance shows anomalously high p-wats so these storms should be efficient rainfall producers. Will therefore go ahead and issue a flash flood watch for parts of southeast Missouri. The shortwave deepens over the east central Plains Thursday and Thursday night, with the low level reflection stretching out and moving across Missouri. The primary area of low level moisture convergence moves east slowly through Thursday morning as the low level circulation stretches out. With the low level forcing moving away, the showers and storms should become less widespread through the day...with the possible exception of parts of southeast Missouri. Guidance is indicating that another round of thunderstorms will be possible in the afternoon across southeast Missouri along the "cold" front associated with the surface low. The increased surface convergence along the front combined with the very moist atmosphere will likely be enough to kick off another round of thunderstorms during the afternoon. P-wats remain high so have continued the flash flood watch through Thursday afternoon. Carney .LONG TERM... (Thursday Night through Next Wednesday) Issued at 329 PM CDT Wed Jul 29 2020 The upper level pattern shifts to a mean longwave trough over the Mississippi Valley with a ridge out west over the Rockies for Friday through at least early next week. With Missouri and Illinois right in the trough axis, we should have relatively cool temperatures and a continuing chance for showers and possibly a few thunderstorms. This convection will likely be mainly diurnally driven, and by a couple of vort maxes that move through, one on Sunday and another on Monday. Carney && .AVIATION... (For the 00z TAFs through 00z Thursday Evening) Issued at 629 PM CDT Wed Jul 29 2020 Thunderstorms have largely left the vicinity of the terminals, with the exception of UIN until 01Z. Otherwise, the threat for VSBY restrictions due to heavy rain has diminished. A weak cold front will stall across southeastern MO and southern IL Thursday morning. Flight conditions will deteriorate to MVFR at all terminals this evening, with all sites except UIN falling to IFR by sunrise. Light showers will persist until the early afternoon Thursday, but the heavier rain expected from that system should evade the TAF sites. MRB && .LSX WATCHES/WARNINGS/ADVISORIES... MO...Flash Flood Watch through Thursday evening for Crawford MO-Iron MO-Madison MO-Reynolds MO-Saint Francois MO-Sainte Genevieve MO-Washington MO. IL...None. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Pocatello ID
223 PM MDT Wed Jul 29 2020 .DISCUSSION...Radar shows a few thunderstorms have formed, mainly from the Arco Desert northeast to the Divide and the Island Park area. This region of convective initiation is well covered by the high-resolution solutions. Of these, the AZ WRF is most aggressive in pulling activity east to the Idaho Falls area later this afternoon. The nested NAM is similar, but weaker and later in the evening, while the rest keep the activity north or dissipate it all together as it moves toward the middle of the Snake Plain. Opted to split the difference and keep weak mention by early evening. Although East Idaho generally under the influence of the upper ridge, some of the high-resolution solutions are introducing isolated convection during the day Thursday. There is a very weak shortwave feature that tries to climb the ridge through Oregon during the day, but the question is moisture availability. At this time, if anything, would expect an isolated sprinkle at best. Much bigger impact across the region will be the increasing temperatures through the end of the week. Heat Advisories remain in place for Thursday and Friday for heat related risks. The latter should be the warmer day, with temperatures reaching 100 or better across portions of the Eastern Magic Valley. Ridge stays amplified into the weekend, but shows signs of flattening somewhat Sunday. Models have been trending slower with the deamplification of the ridge, which will have the tendency to maintain the warmer temperatures longer. Guidance does start to trickle lower Saturday and Sunday but if the trend continues, expect a nudge upward and a potential extension of the heat risk related headlines. Expectations are still for passage of dry cold front early in the week. Models appear to be pinpointing late Monday or Monday night. At this time, only impact still appears to be an uptick in winds for Tuesday. If the feature can pick up some additional moisture, we may have to adjust precipitation chances upward. Until then, dry and continued warm/hot summer conditions will be the theme. DMH && .AVIATION...With some left-over thunderstorms along the border with Montana, as far south as Idaho Falls, although mostly in the mountains and highlands, will occur this afternoon and evening. But that will be the end of thunderstorms for a few days as a very strong high pressure moves into the northern Great Basin. It will bring very hot air into southern Idaho, and by Fri temperatures will approach record territory, with some low elevations reaching 100 degrees F. With the ridge axis directly overhead, wind will be nearly all diurnally and slope-driven and should remain light with little to no upper level support. This all starts to change once the upper level ridge axis slides eastward and allow a Pacific low to move eastward. This will put stronger southwesterly flow overhead, and on Mon or Mon night a very dry cold front may work its way through the longwave ridge, breaking it down over eastern Idaho. After the extreme warmth and drying, it will be very likely that critical fire weather conditions should result. For the remainder of the seven days, wind subsides and the high pressure returns. Only the extreme northeast end of the Targhee NF has any threat of convection on Tue/Wed. Messick && .FIRE WEATHER...TSRA expected to develop in the neighborhoods of KIDA and KDIJ. The HRRR has been consistent in bringing thunderstorms through the KIDA area around the 30/03Z timeframe, and 1 to 2 hours later in the KDIJ vicinity. Otherwise, expect light wind and no CIG with unlimited VSBY everywhere else under strengthening high pressure. Messick && .PIH WATCHES/WARNINGS/ADVISORIES... Heat Advisory from midnight Thursday night to midnight MDT Friday night for IDZ052-054>057. Heat Advisory from midnight tonight to midnight MDT Friday night for IDZ051. && $$
Area Forecast Discussion
National Weather Service Pueblo CO
756 PM MDT Wed Jul 29 2020 .UPDATE... Issued at 753 PM MDT Wed Jul 29 2020 Updated forecast for the cancellation of the remaining counties in Severe Thunderstorm Watch 404, which include Kiowa, Prowers, and Baca Counties. UPDATE Issued at 457 PM MDT Wed Jul 29 2020 Updated forecast for the removal of Bent County from the Severe Thunderstorm Watch. && .SHORT TERM...(This evening through Thursday) Issued at 245PM MDT Wed Jul 29 2020 An upper level ridge will remain centered over northwest AZ thru Thu. This evening an upper trof is forecast to move from northeast WY, into western NE, and then into western KS and far eastern CO Thu morning. Radar/satellite/lighting data are showing isolated showers and storms across the area as of 2 PM, and unlike the last couple days, there is less moisture to work with and storms are faster moving. However over the far southeast plains, dew points are in the upper 50s to lower 60s and the latest SPC mesoanalysis shows 2000-3000 J/kg of CAPE over that area. We have already seen a strong storm over southern Baca County this afternoon, with more storms expected. The HRRR and 4km NAM nest show the best potential for strong to severe storms over the eastern border areas through about 23Z to 00Z and then moves these east of the area. Hail up to ping pong ball size and wind gusts in excess of 60 mph will be the main severe risks in counties near the eastern CO border. Although it is drier over the mtns today, if a stronger storm moves over a recent burn scar, especially the Spring or Decker, there could be a flash flood risk. The HRRR dries out the forecast area by 01Z this evening, and the NAM nest is similar, maybe just some isolated light activity for another hour or two longer than the HRRR indicates. On Thu with the upper trof moving south into the area, breezy northerly winds are expected, especially over the plains. The morning looks dry in all areas, and then in the afternoon it looks like storms could be seen over the eastern border areas where the best moisture and instability will be. The GFS also shows good chances for precip over the Pikes Peak/Palmer Divide regions in the afternoon and evening, and then spreading along and adjacent to the eastern mtns by evening. Western areas look dry on Thu .LONG TERM...(Thursday night through Wednesday) Issued at 245PM MDT Wed Jul 29 2020 .Friday through Monday...This period will have the upper ridge west of Colorado, in the vicinity of the Great Basin, with an upper trough over the Midwest. As a result, expect periodic frontal passages over the eastern plains and eastern mountains with upslope flow advecting moisture into the region from the east. Northwest flow aloft will not tap the deeper subtropical moisture to the south, but there will be some residual moisture in the mid levels. The precipitable waters will range from 0.75 to 1.25 over the eastern mountains and eastern plains with daily fluctuation depending on the amount of low level moisture. Current models and ensembles suggest Saturday may be the drier day in this period. The main question will be the amount of instability for diurnal convection. Bufkit soundings suggest the best chances for diurnal convection will be over the mountains with chances decreasing to the east, where the atmosphere will be more likely capped. The precipitable water amounts are high enough for some locally heavy downpours, and there is a risk for burn scar flash flooding from these stronger storms. Temperatures will be cooler in the plains with the persistent upslope flow. Easterly upslope may be deep enough for the low level moisture to reach into the San Luis Valley and the Upper Arkansas River Valley, increasing chances for convection and heavier rainfall in these areas. Where the low level moisture does not reach, expect high based convection with less rainfall. .Tuesday and Wednesday...Models and ensembles suggest the upper high will drift eastward with the flow aloft becoming more westerly. The increased westerly flow will bring warmer and drier air aloft into the region. In addition, this will lead to drying of the lower levels on the plains with weakening of the upslope flow. Grids show a general drying and warming trend for these days. --PGW-- && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 245PM MDT Wed Jul 29 2020 VFR conditions are expected the next 24 hrs at KALS, KPUB and KCOS. Gusty west to northwest, or north winds are expected into tonight at KPUB and KCOS. There could be a couple showers/storms in the vicinity of KPUB and KCOS this evening causing gusty erratic winds. KALS could see showers and storms in the vicinity through about 02Z. Isolated storms could develop in the late afternoon hours at KCOS and KPUB on Thu. Gusty northerly winds are expected from the morning through the afternoon Thu at KCOS and KPUB, and in the afternoon at KALS. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CARLBERG SHORT TERM...28 LONG TERM...PGW AVIATION...28