Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/30/17

Area Forecast Discussion
National Weather Service Dodge City KS
801 PM CDT Sat Jul 29 2017 ...updated aviation section... .SHORT TERM...(This evening through Sunday) Issued at 241 PM CDT Sat Jul 29 2017 Radar indicating scattered convection trying to develop across western Kansas as of 2 pm. The HRRR may be a little too aggressive with the storms developing late today but it does seem to have the right idea on location for these afternoon and evening storms. These storms late today are not expected to be severe but locally heavy rainfall will be possible. The better chance for convection for western Kansas will occur after midnight, as another upper level wave exiting the Central Rockies and moving out into the Western High Plains. Abundant moisture will be in place ahead of this upper wave and given improving lift developing across western Kansas which will be northeast of a 10C to 14c 700mb baroclinic zone the idea of a cluster of thunderstorms developing ahead of the upper wave and moving across western Kansas late tonight still appears reasonable. Based on where this area of better lift and moisture is forecast to be located overnight place the best chance for convection will be over west central Kansas and portions of north central Kansas. These storms much like the storms Friday night will be capable of producing periods of very heavy rainfall so will continue with the flash flood watch for areas west of Garden City to Hugoton line. May also need to monitor the heavy rains that may develop towards daybreak north of Garden City but since they did not receive much rainfall from last night have decided not to include them in our current Flash Flood Watch. Clouds, Rain showers, and thunderstorms is expected to continue through much of the day on Sunday and as a result will favor the cooler guidance for highs, mainly across west central and north central Kansas. .LONG TERM...(Sunday night through Saturday) Issued at 241 PM CDT Sat Jul 29 2017 Several subtle upper level waves embedded in a northwesterly flow will continue to cross western Kansas over the next 5 days. As each of these upper waves pass there will be a chance for additional showers and thunderstorms across some portion of western Kansas. At this time the area most favorable for precipitation during the first half of the work week will be west of highway 283. Heavy rainfall will be the main hazards for these storms from Sunday night through Tuesday so there may still be a chance for some additional water issues, mainly west of a Garden City to Liberal line Sunday night. Currently have a flash flood watch in effect for tonight and after good collaboration with our neighbors we have decided no to extend the watch just yet and let next shift reevaluate this. Temperatures will not warm much next week given the expected cloud cover, precipitation chances, and 900mb to 850mb temperature trends. The warmer temperatures are expected to be east of Dodge City where more afternoon sunshine is expected while the cooler temperatures will be located further west. Highs mainly in the upper 70s to mid 80s still look on track for Monday and Tuesday. A brief warming trend will occur Wednesday and possibly Thursday as a wedge of warmer 850mb temperatures precede out next cold front. Temperatures will be warming through the mid to upper 80s and even some lower 90s will not completely out of the question across portions of southwest Kansas. Precipitation can not be completely ruled out mid week but the better opportunity will come with the cold front late week. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 756 PM CDT Sat Jul 29 2017 There will occasional thunderstorms impacting the local terminals going forward over the next 12 to 18 hours. Convection should produce locally heavy rain as well as weak to moderate thunderstorm outflow winds overnight, with minimal hail of severe wind threat. Models are not indicating widespread low cigs in the IFR category, however as the convective threat evolves, TAF updates may be needed. && .HYDROLOGY... Issued at 241 PM CDT Sat Jul 29 2017 Models remain in good agreement with high preciptable water values across western Kansas over the next few days as a series of upper level waves embedded in a northwesterly flow crosses the Western High Plains. One cluster of thunderstorms can be expected overnight into Sunday morning as the first in a series of upper level disturbances crosses western Kansas. Based on the rainfall over the past 24 hours combined with the potential rainfall overnight there will a chance for some water issues, especially across west central Kansas. A flash flood watch has been issued by the previous shift for areas west of a Garden City to Hugoton line and this still looks like the most favorable area for flooding issues. Heavy rainfall will also be possible north and northeast of Garden City tonight but these areas have not had much rain over the past few days at this time there are no plans to expand the watch further northeast. Will continue to monitor this and make adjustments as needed. && .PRELIMINARY POINT TEMPS/POPS... DDC 68 79 62 76 / 70 50 60 50 GCK 67 78 62 74 / 80 60 50 40 EHA 70 84 62 78 / 50 50 70 40 LBL 71 84 63 76 / 50 40 60 50 HYS 67 76 61 79 / 60 60 30 20 P28 71 82 64 80 / 30 30 40 30 && .DDC WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch until 7 AM CDT /6 AM MDT/ Sunday for KSZ061- 062-074-084. && $$ SHORT TERM...Burgert LONG TERM...Burgert AVIATION...Russell HYDROLOGY...Burgert
Area Forecast Discussion
National Weather Service Houston/Galveston TX
934 PM CDT Sat Jul 29 2017 .DISCUSSION... The pre-frontal trough was setting off some thunderstorms in Orange and Jefferson counties toward the Sabine at 9:30 PM. The HRRR has been handling the coverage fairly well as of the last couple of runs. 00Z upper air profiles show the potential for a decent low-level inversion to be in place and this is shown on the latest NAMBufr forecast soundings across the forecast area. Best chances will be over the far eastern areas. The current forecast is on track. 40 && .PREV DISCUSSION... /ISSUED 623 PM CDT Sat Jul 29 2017/ AVIATION.../00Z TAF/ Latest radar and GOES 16 imagery show several boundaries across SE Texas. There is the sea breeze along the coast held in check by synoptic pressure gradient support SW to W winds. Sea breeze is making some progress north as winds have backed to SE at KHOU and KIAH, but it is slow progress. To the north is another boundary from Temple to Huntsville to may be near Beaumont. The true frontal boundary is still to the north over the Arklatex pushing SW towards the area. Think VFR conditions continue despite the front moving into the region. Upper level riding looks to be too strong for convection to over come. CAMs show some convection developing in the 08Z to 15Z time frame so will keep VCSH in the TAFs to cover that small possibility. Again it is a small chance and overall confidence in any convection is low. Overpeck PREV DISCUSSION... /ISSUED 347 PM CDT Sat Jul 29 2017/ DISCUSSION... Heat index values range from 100 to 112 degrees across Southeast Texas this afternoon, with highest heat index values being observed near and just behind the seabreeze evident on the KHGX radar moving inland across Brazoria, Galveston, and Chambers counties. Heat will remain the big concern through the early evening hours and a Heat Advisory is in effect for much of the region through 7 PM CDT. Additionally, as of 3 PM CDT, Houston Hobby had hit 100 degrees... tying its record high temperature for today set in 2015. It`s possible that this record may be broken before the seabreeze moves inland later this afternoon. Afternoon surface analysis showed that a cold front had made minimal progress towards the region, stretching from near Wichita Falls across the D/FW Metroplex to south of Shreveport. Ahead of this front, a prefrontal trough stretched from Midland towards Lufkin. Subsidence from upper ridging centered over West Texas has done a good job limiting most convective development along these features so far today, but will need to keep an eye on both through the evening and into the overnight hours as mid-level flow veers from northwest to northerly and allows these boundaries to push farther into the region. Visible satellite imagery has has shown some enhancement to the cumulus clouds across Houston and Trinity counties over the past hour and would expect the northern and northeastern counties to be the first to see isolated shower or thunderstorm development during the late afternoon hours along the prefrontal trough. Loss of heating should result in anything that develops to fall apart by mid-evening, but weak divergence spreading over the region as the upper ridge retreats overnight should allow for another round of isolated to scattered showers and thunderstorms to develop along the cold front as it moves southwest across the region. Anything that develops during the afternoon or evening hours would be capable of a gusty wind threat as forecast soundings continue to indicate an inverted-V signature (meaning that dry sub-cloud air may enhance evaporational cooling leading to downdraft acceleration) with showers and thunderstorms that develop along the front tonight capable of producing locally heavy rainfall. Surface convergence inland along the front is expected to be weak and, as a result, expect greatest shower and thunderstorm coverage across the coastal waters tonight. However, with precipitable water values pooling in excess of 2 inches ahead of the front, expect areas generally along and south/east of Highway 59 to have the greatest potential for seeing rain (and locally heavy rain/ isolated 1-2 inch totals). The front will continue to slowly sag southwest across the region during the day Sunday, with a few showers lingering along it as it washes out approaching the Middle Texas Coast. Otherwise, morning lows on Sunday are expected to range in the mid 70s to low 80s and warm into the low to mid 90s during the afternoon. Drier air behind the front will help keep afternoon heat index values a bit "cooler" than today in the 96-106 range... but Sunday will still feel like summer. Upper ridging will continue to retreat from the region towards the west Monday and Tuesday, with falling mid-level heights resulting in temperatures dropping back to near normal for this time of year (highs in the upper 80s to mid 90s) and increasing rain chances Wednesday into the next weekend. Timing of greatest chances still remains a bit uncertain at this time as it appears to largely depend on when disturbances rotate through upper troughing that becomes established across the eastern CONUS mid to late week. Huffman MARINE... A light southwesterly wind regime can be expected out ahead of the weak front this evening, which should reach the coastal waters overnight tonight and into early Sunday morning. With the passage of this system, high PW values between 2.1-2.4 as well as the added lift could result in isolated to scattered showers and thunderstorms developing in the near and offshore waters. Gusty winds can be expected beneath stronger storms. Expect to see the winds begin to turn due to the influence of the frontal passage, becoming northeasterly by late Sunday morning. Seas should stay around 2 ft in the beginning of week and eventually bump up to 3 ft towards the end of next week. Onshore flow should also return to the forecast late Wednesday into early Thursday. Hathaway && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 78 96 72 96 75 / 20 10 10 10 10 Houston (IAH) 79 95 75 94 76 / 30 20 10 10 10 Galveston (GLS) 81 90 80 90 81 / 30 30 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ Discussion...40 Aviation/Marine...39
Area Forecast Discussion
National Weather Service Wichita KS
921 PM CDT Sat Jul 29 2017 .UPDATE... Issued at 920 PM CDT Sat Jul 29 2017 Convection over the high plains, hasn`t really gotten going too well, considering the weak moisture transport in wrn KS. Latest RAP doesnt show moisture transport increasing considerably late this evening, with instability axis also staying across wrn KS as well. Even if convection can increase much, propagation takes most of the convection to the S-SE, or no where near the wrn sections of the forecast area overnight or early Sun morning. There is some additional convection across SE CO, which may drift east overnight, but think this convection will diminish as it shifts east, away from the main instability axis, which will remain over wrn KS. So plan on cutting back on pops for areas west of I-135 with this in mind. Will leave a slight pop in for Cen KS, but think convective chances are diminishing. Ketcham && .SHORT TERM...(This evening through Tuesday night) Issued at 253 PM CDT Sat Jul 29 2017 Shortwave trough is rotating across the northeast conus with water vapor imagery showing a much weaker impulse tracking across the northern Rockies. Cluster of storms that tracked out of western KS early this morning is currently dissipating over central KS. Should see another round of showers and storms develop over eastern CO/far western KS late this afternoon and track southeast tonight. Just like last night, this activity should go through a slow dissipating trend as it approaches the western fringes of our forecast area with the better 850-700mb moisture transport staying out over western KS. Once again, areas west of I-135 will have the better chances at showers/storms early Sun morning into the early afternoon hours. Overall repeat can be anticipated for Sun night into Mon morning before the better low level moisture gets pushed southwest for Mon night through Tue night. Confidence remains high that below normal temps will remain in place through Tue with highs in the low to mid 80s. Normal highs for this time of year are in the low 90s. .LONG TERM...(Wednesday through Saturday) Issued at 253 PM CDT Sat Jul 29 2017 The main story through these extended periods will be another cold front set to come through toward the end of the work week. There is decent model agreement in shortwave energy diving out of the northern Plains and into the mid Mississippi Valley by Thu night. This will allow an unseasonably strong cold front to push- in from the northeast. Some scattered showers and storms will be tied to this front as it tracks southeast for Thu night into Fri morning. Would not be surprised if medium range models continue this trend that some locations over central KS end up with highs in the 70s for Sat. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 628 PM CDT Sat Jul 29 2017 VFR conditions are expected for the next 24 hours. Convection over the high plains and NW KS is expected to form into an eastward forward propagating MCS late tonight. As it moves further east, think the storms will diminish as they outrun the main instability axis as they approach Cen KS. But a few storms may make into KGBD and KRSL after 08-09z/Sun. So will go with a VCTS for this chance. Expect mid level clouds to remain over most areas west of I-135 for the daylight hours on Sun. Ketcham && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 66 84 64 83 / 10 10 10 10 Hutchinson 65 83 61 82 / 10 20 10 10 Newton 64 83 61 82 / 10 10 10 10 ElDorado 64 84 61 83 / 10 10 10 0 Winfield-KWLD 65 85 63 84 / 10 10 10 10 Russell 63 79 61 82 / 30 40 20 10 Great Bend 64 79 60 81 / 30 40 30 20 Salina 64 83 62 86 / 10 10 10 0 McPherson 65 83 60 83 / 10 20 10 10 Coffeyville 63 86 63 86 / 0 0 0 0 Chanute 61 84 62 84 / 0 0 0 0 Iola 61 83 61 84 / 0 0 0 0 Parsons-KPPF 62 85 63 85 / 0 0 0 0 && .ICT WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Ketcham SHORT TERM...RBL LONG TERM...RBL AVIATION...Ketcham
National Weather Service Jackson KY
1119 PM EDT Sat Jul 29 2017 .UPDATE... Issued at 1100 PM EDT SAT JUL 29 2017 Clouds persist across the southeastern part of the region though they appear to be decreasing in areal extent. Also, light northeast flow persists and is keeping the atmosphere mixed in many locations though winds have slackened in the valleys. Some valley locations in the central part of the CWA have small dewpoint depressions so some valley fog development potential exists though mixing should limit the areal extent. UPDATE Issued at 830 PM EDT SAT JUL 29 2017 Some cumulus and stratocumulus remain across the region with drier air having filtered into the far north. Model guidance continues to suggest that the clouds may linger in some areas past midnight as drier air continues to filter in as high pressure builds in. Some valley fog should develop across the southern part of the area mainly when skies clear. Confidence in the extent of this remains low at this time. Overall, the previous forecast was in good shape and only minor adjustments have been made to hourly grids. && .SHORT TERM...(This evening through Sunday night) Issued at 335 PM EDT SAT JUL 29 2017 19z sfc analysis shows high pressure building into Kentucky from the northwest. This is bringing in drier air that is helping to clear the lingering low clouds through the area. It has also brought a cooler air mass partial responsible for temperatures not climbing out of the 70s today (along with the extensive cloud cover for much of the day). North to northeast winds at 5 to 10 mph with some higher gusts also helped to lock in the cool air. Dewpoints this afternoon varied from the mid 50s north to the low and mid 60s south. Just recently a few light showers have been sinking into far eastern Kentucky - as seen on the RLX radar. Do not expect these to last long, but enough to include in the first few hours of the forecast grids. The models are in good agreement aloft with the longwave pattern for the region through the short term portion of the forecast. They all depict a fairly deep shortwave trough departing to the southeast today and into the evening. In the wake of this, heights will quickly climb with northerly flow and only weak energy available through the rest of the weekend and into Monday morning. Given the agreement and general quiet weather will favor a model blend with a lean toward current radar trends and the higher resolution HRRR for near term details. Sensible weather will feature clearing skies this evening, but not before a few light showers track through our far eastern Kentucky counties this afternoon. For this, will issue the zones using the pre-first period option. Otherwise, clear skies and light winds should make for a good night for radiational cooling, though one not ideal for ridge to valley differences given the position of the high`s center well off to the northwest. Nevertheless have gone with a small to moderate one for low temperatures and hit the river valleys with some patchy fog by morning - potentially locally dense. Sunday will feature more sunshine and warmer temps with highs back into the low 80s most places. Likewise, expect a bit better conditions for a ridge to valley temperature split Sunday night as the high settles in a tad closer, but still not ideal. Patchy fog will again be a concern for the river valleys heading into Monday morning - locally dense. Used the CONSShort as a starting point for all the grids through Monday morning with some point and terrain based adjustments to temps for tonight and Sunday night. Did end up adding in PoPs for this afternoon above the CONSShort - otherwise kept them minimal. .LONG TERM...(Monday through Saturday) Issued at 350 PM EDT SAT JUL 29 2017 The period is expected to begin with a large area of mid and upper level ridging from Mexico into the Western Conus and Southern Plains and troughing from Eastern Canada into the Southeastern Conus. At the surface, high pressure is expected to be centered over the Great Lakes and Lower OH Valley regions to start the period. A colder and drier airmass compared to much of the past couple of weeks will be in place. The upper level ridge will become centered over CA and NV by late Monday into Tuesday with disturbances moving around this ridge and through the westerlies across southern Canada while weak troughing remains in place from the MS Valley east. The pattern is expected to amplify with the ridge building along the US West Coast around midweek before dampening about a week from now. Downstream of this ridge, a Central to Eastern Conus trough should deepen as well. At the same time, the ridge of sfc high pressure will have begun to move east with return flow returning to the area from mid to late week. Weaker disturbances should traverse the area at midweek, Wednesday and combine with daytime heating to bring a return of chances for convection. Chances for convection will increase as a stronger shortwave trough moves into the OH Valley late Thu night into Friday and then moves east of the area by late Friday night. The axis of the mid and upper level trough will remain west of the area through the end of the period. In advance of the shortwave trough moving through the area from Thursday into Friday night, a cold front will approach the area on Thursday and then move across the area Friday into Friday night. Chances for convection will peak as this boundary moves through the area. Pending instability and available moisture, a few stronger storms with gusty winds will be possible, though, locally heavy rain would be the primary threat from this activity. Temperatures will begin the period a couple of degrees below normal for early August with dewpoints mainly in the low to mid 60s. However, by Tuesday into Wednesday as return flow kicks in temperatures will return to near normal for highs with lows a couple of degrees below normal. Temperatures will return to below normal levels with cloud cover and precipitation across the area on Friday and as a colder and drier airmass begins to filter in on Saturday remain below normal. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) ISSUED AT 836 PM EDT SAT JUL 29 2017 VFR cumulus and stratocumulus linger in some locations as high pressure continues to build into the area. Through 6Z or 8Z, skies should gradually clear in all locations with some patchy river valley fog forming towards dawn. At this point, this is not expected to affect the TAF sites through LAMP guidance does suggest some MVFR fog at LOZ and SME. LAMP guidance also hit the fog harder at JKL and SJS, but fog would have to develop in nearby valleys and lift into both locations. With timing of clearing and extent of valley fog development uncertain, kept JKL and SJS as well as SYM VFR. Winds should remain at 10kt or less. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...GREIF LONG TERM...JP AVIATION...JP
Area Forecast Discussion
National Weather Service Marquette MI
735 PM EDT Sat Jul 29 2017 .SHORT TERM...(This evening through Sunday) Issued at 404 PM EDT SAT JUL 29 2017 WV imagery and RAP analysis indicated a mid/upper level ridge from the srn plains into the Great Basin and a trough over the ern CONUS resulting in downstream nnw flow through the wrn Great Lakes. At the surface, high pressure remained across the wrn Great Lakes with light winds and only sct diurnal inland cu across the cwa. Tonight, a weak shortwave trough over nw ontario may support some light showers into wrn Lake Superior but are not expected to reach the Keweenaw before dissipating. With an increase in low level moisture and favorable radiational cooling tonight, expect some patchy shallow fog to develop inland. Otherwise, temps will fall off into the mid to upper 50s. Sunday, Additional moistening with dewpoints into the low 60s with temps into the mid 80s should result in MLCAPE values into the 1000- 1500 J/Kg range. Along with the another weak shrtwv moving into the area, the high res models suggest that lake breeze boundaries cntrl will provide enough low level conv to help trigger isold/sct shra/tsra. 0-6km shear values only in the 15-20 knots and high freezing levels will favor mainly pulse tsra with brief periods of heavy rain. .LONG TERM...(Sunday night through Saturday) Issued at 238 PM EDT SAT JUL 29 2017 Nam shows a 500 mb ridge over the western U.S. and Rockies with a trough in the ern U.S. 00z Mon. The upper pattern evolves into a trough across the upper Great Lakes and northern Plains by 00z Wed. Nam brings in some limited moisture Sun night into Tue along with weak 850-500 mb q-vector convergence, so slight chance pops cannot be ruled out anytime especially during peak daytime heating. Best chance for rain would be Tue afternoon with a weak cold front and lake breeze convergence occurring along with peak heating and would be chance pops at best. Did not make too many changes to the going forecast. In the extended, GFS and ECMWF show a 500 mb ridge over the western U.S. 12z Wed with a trough over the upper Great Lakes which remains into Thu. This trough remains over the area through Sat with sfc high pressure remaining through Sat. Temperatures will remain below normal for this forecast period. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 735 PM EDT SAT JUL 29 2017 With the exception of patchy shallow fog at KIWD overnight, expect VFR conditions with lights winds through Sunday morning. Winds will increase at KCMX in the afternoon ahead of a weak trough crossing Upper MI. A couple showers and possibly a thunderstorm are expected to initiate near KSAW by early afternoon before shifting southward by late afternoon. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 404 PM EDT SAT JUL 29 2017 Winds will remain below 20 knots through the forecast period as high pressure remains over the area into Wednesday. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JLB LONG TERM...07 AVIATION...Kluber MARINE...JLB
Area Forecast Discussion
National Weather Service Pocatello ID
159 PM MDT Sat Jul 29 2017 .DISCUSSION...Convection underway again this afternoon as weak shortwave lifts through Great Basin across the region. PWAT remains around 0.75 inch, and slowly increasing heights also helping to limit development. Expect main threat to remain over higher terrain, though still some signs that gusty outflow could extend south through the Snake Plain from storms that generate along or near the Divide this afternoon. Have slightly increased coverage in the northeast corner of the forecast area to account for this scenario. Otherwise expect upper ridge to continue to slowly build across the region over the next several days. Temperatures continue to warm with slowly decreasing moisture so expect convective potential to decrease through the rest of the weekend into early next week. Trend continues in amplifying ridge axis through mid week, but mainly west of East Idaho. This keeps this area under more of a north-westerly influence, with temperatures not looking as warm later in the week as previously expected. Still thinking only a few degree shift either way, with lower elevation highs Wed-Sat remaining well into the 90s. Ridge axis expected to shift east over Idaho next weekend as Pacific energy shifts inland and shortwave tries to flatten the ridge. Overall, only a few minor tweaks associated with this forecast package from previous thinking. DMH && .AVIATION... Main forecast change was to add VCSH/VCTS to KSUN 18Z-05Z, and VCTS to KDIJ 20Z-04Z. Model consensus paints isolated activity close to both terminals, and both have already seen nearby showers/storms over the past 2 hours. Models keep KBYI/KPIH/KIDA dry. Confidence in precip forecast is moderate. Winds today will be very light (<=10kts), but as always, gusty/erratic (and difficult to forecast in advance) outflow winds will be possible near t-storms. One item worth mentioning...the HRRR for several runs now wants to generate significant outflow winds from supposed future storms in Jefferson/Clark/Fremont counties, and rapidly send them SW down the Snake Plain as a consolidated outflow boundary. Model places 30-40kt gusts at KDIJ/KIDA between 2330z and 0100z, and KPIH between 0130z and 0300z. Frankly I don`t trust this scenario. This outflow is completely dependent on convection occurring in the counties mentioned of sufficient intensity to generate these winds, and despite consistency over several runs, the HRRR has not been perfect with placement/timing of initial storms firing this afternoon. Have left this scenario out of the TAFs and will closely monitor. Activity dies after sunset, with very similar scenario Sun. VFR conditions expected both days all terminals. - KSmith/DMH && .FIRE WEATHER...Isolated thunderstorms forecast in parts of Eastern Idaho, particularly across the Targhee NF areas this evening. A chance for thunderstorms is also forecast in the Central Mountains this evening. Weak high pressure will be in place over SE Idaho which will build tomorrow and Monday. Temperatures will thus rise and drier conditions are expected. Critically dry conditions during the day is expected for most of Southern Idaho and portions of South Central areas. Eastern Idaho is expected to be above 20% RH values at their minimum. Afternoon thunderstorm thunderstorms will once again be possible Sunday along mountain ridges. Other than outflow winds associated with thunderstorms, winds will not be a concern throughout the forecast period. NP/DMH && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Tucson AZ
203 PM MST Sat Jul 29 2017 .SYNOPSIS...An elevated risk of thunderstorms will continue this weekend with locally heavy rain and strong winds with some storms. High temperatures will generally be a few degrees below normal due to the rainfall coverage again Sunday and Monday. The weather pattern will remain favorable for daily thunderstorms this coming week. && .DISCUSSION...The morning upper-air sounding at Tucson showed a very moist air mass in place, with a much weaker steering flow and less vertical wind shear compared to yesterday. A couple of large- scale features in play this weekend with the GOES-16 mid and upper level water vapor imagery depicting two westward tracking upper lows. One exiting the Texas Big Bend and the other over the southern tip of Baja which will influence the upper level flow pattern today and tomorrow. The latest 19Z HRRR solution focused most of the rainfall across Pima, Santa Cruz, and Cochise counties through later this evening. This was in good agreement with the current activity late this morning and early this afternoon. Based on the weaker steering flow and abundant moisture, flash flooding will continue to be the main concern through this evening and likely again Sunday. The overall flow pattern will remain favorable for daily showers and thunderstorms, although a decreasing trend in rain chances after this weekend. Daytime temperatures will warm a few degrees to more normal readings starting Tuesday with the decrease in rainfall coverage. && .AVIATION...Valid thru 30/18Z. Scattered to numerous TSRA/SHRA through later this evening. Brief MVFR/IFR conditions likely in/near TSRA this afternoon and evening. SFC wind variable in direction mainly less than 12 kts, except in the vicinity of TSRA where gusts may exceed 40 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Daily shower and thunderstorm chances will continue into next week across most of southeast Arizona. Elevated humidities will remain in place through the weekend into next week. Outside of thunderstorm winds, expect 20-foot winds to remain at or below 15 mph and follow typical upslope/down valley diurnal patterns. Fire weather concerns are low through at least late next week. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at