Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/25/19

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1146 PM EDT Wed Jul 24 2019 .AVIATION... Aside from a few mid/high level clouds, ample low level dry air associated with high pressure over the srn Gr Lks/nrn Oh Valley will sustain clear skies below 8k ft through Thurs morning. This high will also support light winds through the TAF period. .DTW THRESHOLD PROBABILITIES... * None. && .PREV DISCUSSION... Issued at 349 PM EDT Wed Jul 24 2019 DISCUSSION... Broad anticyclonic flow will build northeastward today as a low to mid-level ridge axis pushes east. Given the synoptic setup with broad subsidence in place and an expansive area of positive omega, a dry forecast will be maintained. Midday obs have confirmed mostly sunny skies with a patchy cu field noted in satellite imagery over the Metro area and toward the MI/OH border. Any additional cu that develops later today should stay elevated with mixing depths around 6 kft. One small point of concern is related to the progression of a line of showers working SE from northern Lower Michigan along a H7 shortwave. Given drier flow, higher stability, and isentropic downglide, the expectation is that any remaining showers will entrain out and dissipate before crossing into the CWA. Thermodynamically, the diurnal heating rate was a bit accelerated earlier, prompting a late morning temperature update. With 12Z 850 mb temps in the 12-14 C range, expect daytime highs to top out shortly in the upper 70s to low 80s. Surface winds will generally be light from the NNW providing no meaningful change in the low-level moisture profile, keeping dewpoints at bay /in the 50s/ and slightly cooler than climatological norms. Nocturnal inversion sets up tonight helping maintain calm to weak winds within a highly stable BL. Radiational cooling will not be maximized overnight due to mid-level cloud deck keeping overnight lows in the upper 50s to low 60s. Still, 2-4 degree dewpoint depressions should be large enough to avoid fog development. Looking ahead to Thursday, the CMC and GFS are outliers as they try and advertise QPF in the Thumb region from H5 shortwave ripples along the apex of the ridge. Even if there was some induced lift, any precip would be high based and likely evaporate before reaching the surface based on saturation levels from RAP soundings. Flow becomes more zonal at the surface while veering with height before becoming SW on Friday. Daily increases in H5 heights suggests a gradual warming trend into the the weekend with dry conditions. Ridge of high pressure will continue to hold in place across the Great Lakes down into the Ohio Valley and east over the Continental northeast on Saturday. This sprawling high pressure system will result in dry weather and extended period of sunshine, pending some diurnal cumulus. Return flow from the departing high pressure system and strengthening low-level jet will act to increase temperatures to above-normal values, marked by h850 temperatures increasing slightly from an average of 14C (18Z Fri) to 16C (18Z Sat), which will translate to an increase in daytime high temperatures into the mid to upper-80s starting Saturday. It is possible portions of Metro Detroit could approach or touch 90 over the urban heat island. Influx of warmer temperatures will also bring little relief overnight as lows hold in the upper-60s to lower-70s Saturday into Sunday and Sunday into Monday. Lack of significant forcing will keep rain and thunderstorm chances low over the weekend as a series of weak shortwaves travels over the area. Better chances for and thunderstorms to enter early next week, tied to an approaching cold front, which will also act to return temperatures to near or slightly below normal highs (low to mid-80s) by Tuesday. MARINE... Outside of widely scattered showers across northern Lake Huron the remainder of today, dry weather will prevail through the day Friday as high pressure expands eastward across the region. The high pressure will allow for light southwest to southerly winds across the local waters through Thursday. Southwest winds will then become moderate at times with gusts 15-20 knots, especially across Saginaw Bay and into the central Lake Huron basin, Friday and heading into the weekend as the area of high pressure slides eastward and the pressure gradient tightens slightly ahead of an approaching cold front from the northern Great Lakes. This cold front will bring increasing chances for showers and a few thunderstorms Friday night and into the weekend, especially across the Lake Huron basin. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...NONE. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ AVIATION.....SC DISCUSSION...KK/AM MARINE.......IRL You can obtain your latest National Weather Service forecasts online at
Area Forecast Discussion
National Weather Service Hastings NE
645 PM CDT Wed Jul 24 2019 .SHORT TERM...(This evening through Thursday) Issued at 400 PM CDT Wed Jul 24 2019 Slight chance for t-storms tonight into Thursday is main forecast concern in the short term. It`s another pleasant summer afternoon across the CWA with temperatures in the upper 70s to 80s for most, under sunny to mostly sunny skies. There are a few 90s across the far SW. Dew points remain seasonably low in the 50s to low 60s. Morning upper air analysis along with recent water vapor still reveal a highly amplified upper flow pattern across the CONUS, with troughing over the E and ridging over the 4-Corners extending northward into the N Rockies. In fact, H3 flow at OAX and LBF was nearly meridional. A potent upper low has progressed into SW Canada. A weak mid level perturbation is noted over N WY and the SW Canada upper low will help eject this wave over top the ridge then SE through the area tonight into Thu. We will continue to see dry and pleasant conditions this eve, with ongoing breezy conditions relaxing some near sunset. Will likely see scat tstms dev over the Front Range and adjacent central High Plains this eve, then move E, aided by the mid level wave and a 35-45kt LLJ. Last several runs of the HRRR bring this activity into far W/NW portions of the CWA around 09-10Z. The LLJ will veer toward sunrise, but point forecast soundings indicate much of the moisture/weak instability is rooted above any lift from the LLJ this far E, closer to the H65-H7 layer. Thus, think most of this activity will be driven by weak isentropic ascent around the 315K layer and the weak wave. Expanded the POPs a bit S/SE compared to last forecast, especially during the Thu AM time frame. Do not expect Thu to be a washout by any means, but model trends and pattern recognition suggests we could have broken ACCAS and iso to widely scat shwrs/weak tstms around for much of the day with spotty rain amnts generally .1-.2" or less. The clds will probably hamper the warmup for one more day, which is fine by this forecaster! Continued Srly flow and warmer start to the day should still yield widespread 80s, with some low 90s for Phillips and Rooks Co. .LONG TERM...(Thursday night through Wednesday) Issued at 400 PM CDT Wed Jul 24 2019 Warmer temperatures then potential for t-storms Sun are main forecast concerns. The aforementioned SW Canada trough will swing E through south central Canada Thu night into Fri. This will temporarily flatten the western ridge but also drag the low level thermal ridge a bit further E for Fri. Expect a 2-4C incr in H85 temps from Thu to Fri which should yield Fri aftn highs in the upper 80s to upper 90s. Upper heights incr and the lee trough deepens on Sat which will promote H85 incr another couple of deg. Sat continues to look like the warmest day of the next 7. Expect widespread 90s with some low 100s possible over the S and W. The forecast continues to be dry Thu night-Sat, though will need to monitor for an iso elevated t-storm Thu night with lingering elevated instability. A cold front will approach the area on Sun from the NW. However, the upper low responsible for the front will be weakening and moving E across the Great Lakes, so there will not be much upper support for this front to work with. Not surprisingly, models are somewhat scant with pcpn chances for the local area with this frontal passage. Nonetheless, some moisture convergence and cooling mid-level temps could support some convection along and behind the front. Currently have only 20-30% POPs Sun into Sun night. Incr clds should lead to cooler temps Sun for NE zones, but expect another warm day for KS zones in the mid to upper 90s. Will see a brief cool down to near or slightly below normal temps on Mon before a warming trend develops for Tue as the upper ridge edges E and expands once again. Latest EC suggests middle of next week could be quite warm. So, overall, a fairly typical summertime pattern with warm temps and only a few pcpn chcs. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Thursday) Issued at 645 PM CDT Wed Jul 24 2019 Significant Wx: LLWS at EAR for a few hrs tonight. Tonight: VFR with no clds at or below (AOB) 10K ft. S-SE winds 10-15 kt. LLWS dvlps at EAR 08Z-11Z. Confidence: High Thu: VFR with CIGs 9-10K ft. Could see a few sprinkles or a brief -SHRA at both terminals. S winds 10-20 kt with G20-25 kt. Confidence: High && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ SHORT TERM...Thies LONG TERM...Thies AVIATION...Kelley
Area Forecast Discussion
National Weather Service Pueblo CO
330 PM MDT Wed Jul 24 2019 .SHORT TERM...(This evening through Thursday) Issued at 241 PM MDT Wed Jul 24 2019 Scattered convection again developing over the mountains this afternoon as upper level high pressure remains centered near the 4 corners. Main threat into the evening will be locally heavy rainfall, with flash flooding possible over area burn scars as storms will be very slow moving. Only a slight chance for storms along I-25 as activity remains mainly across the mountains, although HRRR hints at some weak cells forming along the Palmer Divide then drifting south toward Colorado Springs after 00z. On Thursday, upper high sinks south into NM, with steering currents becoming weak wly across srn CO by late afternoon. This pattern should be more favorable for convection to move off the mountains and into the I-25 corridor and adjacent plains than has been the case over the past few days. Weak front/trough will also sink south through the plains early Thu, with low level winds turning e-ne over most of the eastern mountains and southeast plains behind the boundary by late in the day. Moisture and instability will remain plentiful across the region, and with weak upper energy rotating around the high, should be at least some minor upward motion to aide in convective development. Overall, parameters look favorable for fairly widespread convection across the mountains and I-25 corridor, with enough potential for heavy rainfall to warrant the issuance of a flash flood watch for eastern mountains burn scars beginning noon on Thu. Severe threat looks rather low given weak shear, though with boundary in the area and CAPE running over 1000 J/KG, some brief mainly pulse severe storms may be possible. .LONG TERM...(Thursday night through Wednesday) Issued at 241 PM MDT Wed Jul 24 2019 Models continue to be in good agreement through the extended period with ensemble spreads improving over the past couple of cycles. This leads to increased forecast confidence through the extended period. Thursday into Friday...expect ongoing showers and thunderstorms across the region on Thursday as an upper disturbance passes over north central Colorado and into the Eastern Plains overnight. Locally heavy rainfall and flash flooding are all possible with stronger storms, especially on area burn scars. As storms shift east across the Plains, gusty outflow winds to near 45 mph and small hail will also be possible. As we head into Friday morning, models in good agreement with activity dissipating and shifting south and east of the area. On Friday, the upper level high is forecast to retrograde into southern California. This will limit shower and thunderstorm activity to mainly the Continental Divide, with the best coverage over the San Juan and southern Sangre de Cristo ranges. Lack of flow aloft should help keep movement limited to drifting southward. If one of the stronger storms happens to move over a burn scar, flash flooding may be possible. As for the Plains, they will likely remain dry Friday evening and overnight. Saturday and the upper high moves into Southern California, flow aloft will transition northwesterly. An upper shortwave trough is forecast to moves east out of the Northern Rockies on Saturday and into the Plains on Sunday. Expect an increase in shower and thunderstorm coverage on Saturday afternoon, especially over the mountains. Storms will likely move off to the southeast and into the I-25 corridor before dissipating overnight. A cold front is forecast to drop south late Saturday night into Sunday morning with increased low level moisture and low level upslope flow from the northeast behind the front. Given the increase in moisture and upslope flow, prolonged periods of locally moderate to heavy rainfall will be possible, especially over the Eastern Mountains. This may also lead to much elevated flash flood potential Sunday afternoon and evening on area burn scars. This will need to be monitored closely. Storms are forecast to shift east and dissipate during the evening hours. Monday through Wednesday...the high pressure is forecast to move back east into the Four Corners region early next week. Models have come in drier for Monday and Tuesday and heights rise and drier air works into the area. There will likely be an uptick on Tuesday over the mountains with isolated to scattered showers and thunderstorms. Temperatures will also climb Monday and Tuesday with mid to upper 90s across the lower elevations. By Wednesday, energy will work its way north under the ridge and bring another period of increased shower and thunderstorm coverage into the middle of the work week. Mozley && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 241 PM MDT Wed Jul 24 2019 VFR conditions expected at all taf sites the next 24 hrs. Thunderstorms over the mountains this afternoon will drift toward lower elevations this evening, and will keep a VCTS at KALS and KCOS 22z-03z where some weakening convection is possible. Storms diminish after sunset, with clearing skies overnight. Weak cold front and increased moisture will lead to more widespread thunderstorm activity on Thursday, with storms impacting all terminals during the afternoon and evening. && .PUB WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch from Thursday afternoon through Thursday evening for COZ072>075-079-080-087. && $$ SHORT TERM...PETERSEN LONG TERM...MOZLEY AVIATION...PETERSEN